JP2002240730A - Transmission ratio fixing device for vehicle steering system - Google Patents

Abstract

(57) [Summary] [PROBLEMS] To reduce the relative rotation amount of both rotating bodies when the rotation ratio between the input-side rotating body and the output-side rotating body is fixed, and to play between the two rotating bodies in a fixed state. To be smaller. SOLUTION: When a first clutch plate 92 supported by a rotating shaft body 43 is moved in the direction of the rotating shaft, the first clutch plate 92 is engaged with a second clutch plate 93 fixed to an input-side rotating body 41, and the input-side rotation is performed. The body 41 and the rotating shaft 43 are connected so as not to rotate relative to each other. Each of the clutch surfaces 92a, 93a has a ridge 92b, 93b having a tapered cross section which becomes narrower toward the top.
Are formed so as to extend radially all around the rotation axis. The ridges 92b, 93b are engaged with each other by the tapered surfaces 92c, 93c abutting against each other, and the two rotating bodies 4
1 and 42 are engaged so that relative rotation stops.

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a transmission ratio fixing device for a vehicular steering system capable of changing a transmission ratio of a steering angle of a steered wheel to a steering angle of a steering wheel in a vehicle.

[0002]

2. Description of the Related Art Conventionally, as such a steering device, there is one disclosed in Japanese Patent Application Laid-Open No. H11-001175. In this steering device, as shown in FIG. 11A, the rotation of the steering is input to the input shaft 101 of the speed reducer 100, and the motor housing of the electric motor 104 in which the rotor 103 is provided on the output shaft 102 of the speed reducer 100. The rotation is output from 105. Then, for example, the electric motor 104 is controlled based on the vehicle speed, and the relative rotation angle of the motor housing 105 with respect to the rotation angle of the rotor 103 is controlled, so that the rotation ratio of the rotation angle of the motor housing 105 to the rotation angle of the input shaft 101 is controlled. Is controlled according to the vehicle speed. As a result, the transmission ratio of the steering angle of the steered wheels to the steering angle of the steering wheel is adjusted so that favorable steering characteristics of the vehicle are obtained according to the vehicle speed.

In this steering apparatus, when the motor cannot be controlled as in the case of failure of the motor 104, the rotation angle of the motor housing 105 with respect to the rotation angle of the input shaft 101 cannot be controlled, and the transmission ratio of the steering angle is reduced. It cannot be adjusted. Therefore, when the motor 104 breaks down, the rotation ratio from the input shaft 101 to the motor housing 105 is fixed to the rotation ratio at that time by directly connecting the rotor 103 and the motor housing 105 so that they cannot rotate relative to each other. Then, the steering function is ensured by fixing the transmission ratio of the steering angle from the steering wheel to the steered wheels to the transmission ratio at that time. In this steering device, the motor housing 10
The slide pin 107 is extended from the solenoid actuator 106 provided on the rotor 103 to the rotor 103 side.
As shown in (b), the rotor 103 is directly connected to the motor housing 105 by being inserted into any of the plurality of pin holes 108 provided in the rotor 103.

Further, Japanese Patent Laid-Open Publication No.
In the steering apparatus disclosed in JP-A-03-03894, FIG.
2 (a) and (b), the motor housing 11
0 is swung toward the rotor 113 by the electromagnetic coil 112, and the engagement recess 1 provided in the rotor 113 is rotated.
The rotor 113 and the motor housing 110 are directly connected by engaging the engagement protrusion 115 provided on the swing member 111 with the rotor 14.

[0005]

However, in the steering apparatus disclosed in Japanese Patent Application Laid-Open No. H11-001175, the slide pin 107 is moved only when the position of the slide pin 107 coincides with the position of any of the pin holes 108. Hole 10
8 is inserted. For this reason, the rotation angle relationship between the rotor 103 and the motor housing 105 when they are directly connected is limited, and the rotation ratio from the input shaft 101 to the motor housing 105 is not immediately fixed to the rotation ratio at that time. As a result, there is a problem that it takes time from when the motor 104 cannot be controlled until the transmission ratio of the steering angle is fixed.

Therefore, in order to further increase the rotational angle relationship between the rotor 103 and the motor housing 105 which can directly connect the motor housing 105, a pin hole 108 is formed with respect to the diameter of the slide pin 107.
May be increased. However, in this case, since the slide pin 107 inserted into the pin hole 108 can play with the pin hole 108, the play in the rotational direction between the directly connected rotor 103 and the motor housing 105 increases. . For this reason, the play between the steering wheel having a fixed transmission ratio of the steering angle and the steered wheels increases.

In the steering apparatus disclosed in Japanese Patent Application Laid-Open No. H11-034894, only when the position of the engagement projection 115 coincides with any one of the four engagement recesses 114, the engagement projection 115 is It is engaged with the engagement recess 114. For this reason, similarly to the steering device described above, the rotational angle relationship when the rotor 113 and the motor housing 110 are directly connected is limited, or the directly connected rotor 113 and the motor housing 11 are not connected.
There is a problem that play in the rotation direction with zero becomes large.

SUMMARY OF THE INVENTION The present invention has been made to solve the above-mentioned problems, and an object of the present invention is to fix the rotation ratio between an input side rotating body and an output side rotating body when fixing a rotation ratio between an input side rotating body and an output side rotating body. It is an object of the present invention to provide a transmission ratio fixing device for a vehicle steering device that can prevent relative rotation of a side rotator and can further prevent relative rotation of both rotators even in a fixed state. is there.

[0009]

According to a first aspect of the present invention, there is provided an input-side rotator to which rotation by steering is input, and an input-side rotator receiving a rotation input to the input-side rotator. An output-side rotator for outputting the output rotation, and a rotation-ratio variable mechanism including a plurality of rotation transmitters for transmitting the rotation input to the input-side rotator to the output-side rotator. The variable ratio mechanism is a vehicle steering device capable of adjusting the rotation ratio of the output side rotator to the input side rotator by controlling the rotation of one of the rotation transmission members by an electric motor. A first connecting means integrally rotatably provided on one of the first transmitting members, and one of the rotation transmitting members excluding the first transmitting member on the same rotation axis as the first transmitting member. The second transmission body rotatably supported is provided so as to be integrally rotatable. And a second coupling means, said first
The connecting means and the second connecting means are engaged with each other so as to integrally connect the two transmission bodies so as to be integrally rotatable, and are engaged so that the relative rotation between the two transmission bodies becomes smaller as the transmission bodies are closer to each other in the rotation axis direction. The point is to do.

According to the first aspect of the present invention, when the two connecting means are engaged, the two transmitting members are connected so as to rotate integrally, and the rotation ratio of the output side rotating body to the input side rotating body is fixed. You. At this time, the two connecting means engage so as to make the relative rotation of the two transmitting bodies smaller as they come closer to each other in the rotation axis direction, so that the rotational angle relationship between the two transmitting bodies in the initial stage of engagement is expanded to a wider range. You. On the other hand, when both connecting means are more engaged, the relative rotation between the two transmitting members is smaller. In addition, when an external force is applied to rotate the two transmission members that are integrally rotatably connected by the two connection members, the two connection members are rotated in the rotation axis direction so that the relative rotation of the two transmission members becomes larger. Try to separate from each other. For this reason, if the two connecting means are separated from each other in the direction of the rotation axis to release the engagement in a state in which an external force for relatively rotating the two transmitting bodies connected to each other is applied, the both connecting means are easily formed. Separates from the engaged state. Therefore, when the rotation ratio of the output-side rotator to the input-side rotator is fixed, the input-side rotator and the output-side rotator can be prevented from rotating relatively to each other. The relative rotation of the body can be reduced.

According to a second aspect of the present invention, in the first aspect, the first connecting means and the second connecting means are provided on an engaging surface facing each other in the rotation axis direction and on the engaging surface. A plurality of projecting ridges, each of which is provided so as to extend from the inner peripheral side to the outer peripheral side with respect to the rotation axis, and has a substantially tapered cross section whose width becomes narrower toward the top. And the first connecting means and the second connecting means connect the two transmission members integrally rotatably by contacting the tapered surfaces of the ridges provided on the respective engagement surfaces with each other. The gist of the present invention is to engage such that the relative rotation between the two transmission bodies becomes smaller as the distance between the transmission bodies becomes closer in the rotation axis direction.

According to the invention described in claim 2, according to claim 1,
In addition to the operation of the invention described in the above, the connecting means can be engaged by bringing the protruding ridges of both connecting means into contact with each other substantially in the radial direction with respect to the rotation shaft, so that each protruding part can be engaged. The applied load can be reduced. For this reason, since it is not necessary to increase the height of each ridge, both connecting means can be prevented from increasing in the rotation axis direction.

According to a third aspect of the present invention, in the first or second aspect, at least one of the first connecting means and the second connecting means is moved in the direction of the rotation axis. The gist of the present invention is to provide a coupling operation means disposed from a non-engagement position where both coupling means do not engage to an engagement position where both engagement surfaces engage.

According to the invention described in claim 3, according to claim 1 of the present invention,
Alternatively, in addition to the effect of the invention described in claim 2, the engagement state between the first connecting means and the second connecting means is switched by the steering device itself.

According to a fourth aspect of the present invention, in the third aspect of the present invention, the connection operation means is provided so as to be integrally rotatable with the first transmission body and connects the first connection means in the direction of the rotation axis. And a switching means for switching the first connecting means in the direction of the rotation axis with respect to the supporting means in response to power supply or non-power supply. The gist of the present invention is to switch and move to one of a non-engagement position that does not engage with the second connection means fixed to the transmission body and an engagement position that engages with the second connection means.

According to the invention set forth in claim 4, according to claim 3,
In addition to the effect of the invention described in the above, only the first connecting means is operated so as to move in the direction of the rotation axis, and the second connecting means is the second connecting means.
Since it is fixed to the transmission body, the structure is simpler than a configuration in which both connecting means are moved in the rotation axis direction to switch between engagement and non-engagement.

According to a fifth aspect of the present invention, in the fourth aspect of the present invention, the switching means is provided on the support member and urges the first connecting means with an elastic force. And an electromagnetic coil for moving the first connecting means against the urging force of the urging means during power supply and holding the first connecting means not engaged with the second connecting means. The gist is to have the following.

According to the invention set forth in claim 5, according to claim 4,
In addition to the operation of the invention described in (1), the first connecting means is switched between the engaged position and the disengaged position by one electromagnetic coil and the urging means, so that the first connecting means is switched by the pair of electromagnetic coils. The structure is simpler than the structure.

According to a sixth aspect of the present invention, in the fifth aspect of the invention, the two connecting means are arranged such that the urging means urges the first connecting means to engage the second connecting means. If the magnitude of the external force applied to rotate the first transmission member and the second transmission member relative to the first transmission member and the second transmission member exceeds an allowable value while maintaining the state, the urging force of the urging means is applied. In this case, the transmission members are separated from each other in the direction of the rotation axis to engage with each other so as to allow relative rotation of the transmission members.

According to the invention described in claim 6, according to claim 5,
In addition to the operation of the invention described in the above, in the state where both connecting means are engaged and the relative rotation of both transmission bodies is regulated, when an excessive external force for rotating both transmission bodies is applied, The two connecting means are separated from each other in the direction of the rotation axis so as to allow the relative rotation of the transmission members so that the relative rotation of the transmission members becomes larger. For this reason, no further excessive external force is applied to each transmission body. Then, when the external force applied to both transmission members is no longer excessive, the urging force causes the two connecting means to be engaged again in the rotation axis direction, thereby restricting the relative rotation of both transmission members. Therefore, it is not necessary to give each transmitter a strength to oppose an excessive external force that is temporarily applied, such as an excessive reverse input, so that higher reliability can be ensured. The body can be reduced in size.

[0021]

DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS One embodiment of the present invention will be described below with reference to FIGS. As shown in FIG. 2, the vehicle steering system 10 includes a case body 11 as a non-rotating portion supported on the vehicle side, and a steering shaft 12 and an output shaft 13 extending from the case body 11. . A steering wheel (not shown) is mounted on the steering shaft 12. The output shaft 13 is connected to an input portion of a steering gear box via a connection shaft and a pinion shaft (not shown). In this embodiment, the steering shaft 12 is an input-side rotator, and the output shaft 13 is an output-side rotator.

The case body 11 comprises a fixed case part 14 and a movable case part 15. The fixed case portion 14 is fixed to the vehicle, and the movable case portion 15 is supported in a movable state with respect to the fixed case portion 14.

The fixed case section 14 includes a first case 16, a motor case 17, a second case 18, and a third case 19. The first case 16 and the second case 18 are fixed to the vehicle, and the motor case 17 is supported between the two cases 16, 18 connected by bolts 20. The third case 19 is fixed so as to be fitted to the end of the second case 18.

The movable case section 15 includes a slide case 21.
And a tilt case 22. Slide case 2
1 is supported so as to be movable in the axial direction while being fitted to the third case 19. The tilt case 22 is supported on the end of the slide case 21 by a connecting portion 23 so as to be tiltable up and down.

As shown in FIG. 3, the steering shaft 12 includes a support tube 2 fixed to a tilt case 22.
4 rotatably supported. One end of a sub shaft 26 is connected to an end of the steering shaft 12 via a universal joint 25. The other end of the sub shaft 26 is supported in the fixed case portion 14 so as to be rotatable and movable in the axial direction. The steering shaft 12 and the slide case 2 together with the tilt case 22
1 and the sub shaft 26 can be tilted up and down. Further, the steering shaft 12 is movable in the axial direction of the sub shaft 26 with respect to the fixed case portion 14 together with the slide case 21, the tilt case 22, and the sub shaft 26. That is, the steering device 10 has a tilt function of adjusting the position of the steering wheel in the vertical direction, and a telescopic function of adjusting the position of the steering wheel in the longitudinal direction.

On the other hand, the output shaft 13 is supported by the fixed case portion 14 so as to be rotatable and movable in the axial direction. Further, as shown in FIG. 4, the steering device 10 has a variable rotation ratio mechanism for changing a rotation ratio which is a ratio of a rotation angle of the output shaft 13 to a rotation angle of the steering shaft 12 corresponding to the steering angle of the steering wheel. 40
It has. The variable rotation ratio mechanism 40 includes the fixed case 1
4. The rotation ratio variable mechanism 40 includes an input-side rotator 41, an output-side rotator 42, a rotation shaft 43, a carrier 44, and the like. The input-side rotator 41, the output-side rotator 42, the rotation shaft 43, and the carrier 44 are all cylindrical.

The input side rotating body 41 includes a sleeve portion 45 having the sub shaft 26 disposed outside one end thereof,
And a gear portion 46 having a diameter larger than 5. The input side rotator 41 is formed by a bearing 47 provided between the sleeve 45 and the second case 18 and a bearing 48 provided between the gear 46 and the second case 18. Are supported so as to be rotatable with respect to the axis and immovable in the axial direction.

An input side sleeve 50 is supported inside the sleeve portion 45 via a bearing 49 so as to be rotatable and immovable in the axial direction. The auxiliary shaft 26 is supported by the input side sleeve 50 by a spline connection so as to be relatively non-rotatable and movable in the axial direction.

The input-side rotator 41 includes an input-side sleeve 50.
Is connected to the input side sleeve 50 so as to rotate integrally with the input side sleeve 50. on the other hand,
An input side ring gear 52 is provided on the inner peripheral surface of the gear portion 46.

As shown in FIG. 4, the output side rotator 42 is
The output shaft 13 includes a sleeve portion 58 externally fitted to the output shaft 13 and a large-diameter gear portion 59 disposed on the outer peripheral side of the sleeve portion 58. The output side rotating body 42 is connected to the sleeve portion 58 and the first
A bearing 60 provided between the case 16 and a bearing 61 provided between the sleeve portion 58 and the input-side rotator 41 allows the fixed case portion 14 to rotate and not move in the axial direction. It is supported by.

The sleeve portion 58 supports the output shaft 13 so as to be integrally rotatable, and when an excessive external force is applied to the output shaft 13 in the axial direction toward the steering shaft 12, the output shaft 13 is moved toward the steering shaft 12. Move relative. That is, the steering device 1
No. 0 has an impact absorbing function to prevent the entire steering device 10 from moving to the driver's seat side by immersing the output shaft 13 in the fixed case portion 14 at the time of a vehicle collision.

The gear portion 59 is provided so as to be included in the gear portion 46 of the input-side rotating body 41, and is disposed closer to the input-side rotating body 41 in the axial direction than the input-side ring gear 52. 62 are provided. The number of teeth of the output side ring gear 62 is greater than the number of teeth of the input side ring gear 52. In the present embodiment, the number of teeth of the input side ring gear 52 is set to “87”, and the output side ring gear 62
Is "91".

The rotary shaft 43 includes a motor shaft 63, a sun gear 64, and a connecting sleeve 65, both formed in a cylindrical body and arranged outside the output rotary body 42. The rotating shaft 43 is formed by integrally connecting the motor shaft 63 and the sun gear 64 by a connecting sleeve 65. The rotating shaft 43 is fixed to a fixed case part by a bearing 66 provided between the motor shaft part 63 and the first case 16 and a bearing 67 provided between the motor shaft part 63 and the second case 18. It is supported so as to be relatively rotatable with respect to the rotating body 14 and the output side rotating body 42 and immovable in the axial direction.

A cylindrical rotor magnet 68 is externally fitted and fixed to the motor shaft portion 63 between the bearings 66 and 67. The sun gear 64 includes an input side sun gear section 70 facing the input side ring gear 52 and an output side sun gear section 71 facing the output side ring gear 62. The number of teeth of the input-side sun gear 70 is greater than the number of teeth of the output-side sun gear 71. In the present embodiment, the number of teeth of the input-side sun gear 70 is set to “51”, and the number of teeth of the output-side sun gear 71 is set to “47”.

The carrier 44 is provided without being directly connected to the input-side rotator 41 and the output-side rotator 42. As shown in FIG. 1, the carrier 44 is rotatable by a thrust bearing 72 provided between the input side rotating body 41 and a thrust bearing 73 provided between the carrier 44 and the output side rotating body 42. It is supported by the input side rotating body 41 and the output side rotating body 42 so as not to be movable in the axial direction.

The carrier 44 has an input side ring gear 52
The six input-side planetary gears 74 meshing with the input-side sun gear 70 are rotatably supported by support shafts 75 provided at substantially equal angular intervals. An output planetary gear 76 meshing with the output side ring gear 62 and the output side sun gear portion 71 is rotatably supported on the same support shaft 75. Therefore, the number of teeth of each input-side planet gear 74 is
The number of teeth of the output side planetary gear 76 is smaller than that of the output side planetary gear 76. In the present embodiment, the number of teeth of the input side planetary gear 74 is “18”, and the number of teeth of the output side planetary gear 76 is “22”.

In this embodiment, the input-side rotator 41, the output-side rotator 42, the rotary shaft 43, the carrier 44, the input-side planetary gear 74, and the output-side planetary gear 76 are rotation transmitting members.
Further, the rotating shaft 43 is a first transmitting body, and the input-side rotating body 41 is a second transmitting body.

The variable rotation ratio mechanism 4 configured as described above
0 transmits the rotation inputted from the input side rotating body 41 to the output side rotating body 42 through the transmission path of the input side planetary gear 74, the carrier 44 and the output side planetary gear 76. At the same time, the input side planet gear 74, the sun gear 64 and the output side planet gear 76
Is output to the output side rotating body 42 also in the transmission path of

At this time, in a state where the rotation shaft 43 is rotated together with the input side rotation body 41 so as not to rotate relative to the input side rotation body 41, the rotation ratio variable mechanism 40 is rotated together with the rotation shaft body 43 and the carrier 44. The output rotator 42 is rotated integrally with the input rotator 41. This is the rotating shaft 43,
This is because the input-side rotator 41 and the carrier 44 rotate integrally without rotating relative to each other. That is, the rotation ratio variable mechanism 40 transmits the rotation inputted to the input side rotating body 41 from the steering shaft 12 by steering the steering wheel to the output side rotating body 42 at the transmission ratio “1”.

When the rotation shaft 43 is relatively rotated with respect to the input-side rotator 41, the rotation-ratio variable mechanism 40 rotates with respect to the input-side rotator 41 at a transmission ratio represented by the following equation (1). The relative rotation Nm of the shaft 43 is transmitted to the output-side rotator 42. Here, the relative rotation speed of the rotation shaft 43 with respect to the input rotation body 41 is Nm, and the rotation speed of the output rotation body 42 with respect to the input rotation body 41 is N2. The number of teeth of the input side ring gear 52 is R1, and the number of teeth of the output side ring gear 62 is R2.

Nm / N2 = (R2−R1) / R2 (1) Here, since the efficiency between the gears can be assumed to be almost 100%, the following equation (2) is established. Here, the torque applied to the rotating shaft 43 is defined as Tm, and the torque applied to the output side rotating body 42 is defined as the output torque Tr2.

Tm / Tr2 = (R2−R1) / R2 (2) Accordingly, the rotation ratio variable mechanism 40 includes the input side ring gear 52
The rotation of the rotary shaft 43 with respect to the input rotary body 41 is transmitted to the output rotary body 42 at a reduction rotation ratio determined by the number of teeth of the output ring gear 62 and the number of teeth of the output ring gear 62.

As shown in FIG. 4, the outer peripheral portion of the sleeve portion 58 which is a component of the output side rotating body 42 is
Electrically-controlled clutch device 8 as a transmission ratio fixing device for connecting relative rotation of motor 3 and input-side rotating body 41 to each other.
4 are provided.

As shown in FIG. 1, the clutch device 84
Both of them comprise a fixed part 85 and a rotary part 86 arranged outside the rotary shaft 43. The fixing portion 85 includes an annular yoke 87 fixed to the second case 18, and an electromagnetic coil 88 provided in a circumferential groove of the yoke 87. A power supply line 89 is externally connected to the electromagnetic coil 88 via a hole provided in the second case 18.

The rotating section 86 includes a support member 90, a plurality of compression coil springs 91, a first clutch plate 92, and a second clutch plate 93. In this embodiment, the yoke 87, the electromagnetic coil 88, and the compression coil spring 91 constitute switching means, and the support member 90 is a support means.
1 is an urging means. The yoke 87, the electromagnetic coil 8
8. The support member 90 and the compression coil spring 91 constitute the connection operation means. Further, the first clutch plate 92 is a first connecting unit, and the second clutch plate 93 is a second connecting unit.

The support member 90 is formed in an annular shape, and is externally fitted and fixed to the motor shaft 63 of the rotating shaft 43. The support member 90 includes a tubular portion 94 fixed to the motor shaft portion 63 in a state of being fitted to the outside, and a flange portion 95 projecting radially from the outer peripheral surface of the tubular portion 94. The flange portion 95 is provided with a plurality of holes that open toward the input side rotating body 41, and a compression coil spring 91 is mounted in each of the holes.

As shown in FIGS. 1 and 5, the first clutch plate 9
Numeral 2 is formed in an annular shape, and is loosely fitted to the cylindrical portion 94 so as to be movable in the axial direction and relatively non-rotatable. An annular clutch surface 92a as an engagement surface is formed on an end surface of the first clutch plate 92 in the rotation axis direction. Clutch surface 9
2a is formed so as to extend along a plane centered on the rotation axis of the first clutch plate 92 and orthogonal to the rotation axis, that is, oriented in the rotation axis direction. The clutch surface 92a has a plurality of ridges 92b extending radially about its rotation axis.
Are formed at equal angular intervals. Each of the ridges 92b has the same shape, and as shown in FIG. 7, is formed to have a tapered cross section in which the width decreases toward the top, and a pair of tapered surfaces 92c is formed.
It has.

The first clutch plate 92 urged by the compression coil spring 91 is moved rightward in FIG. 1 by a snap ring 81 fitted on the motor shaft 63 and a plate 82 made of a non-magnetic material. The movement amount is regulated within a predetermined value. This is for the purpose of preventing the components from dropping off when the clutch device 84 is assembled.

As shown in FIGS. 1 and 6, the second clutch plate 9
Numeral 3 is formed in an annular shape, and is fixed so as to rotate integrally with the input-side rotator 41. The second clutch plate 93 has an annular clutch surface 93a as an engagement surface on an end surface of the first clutch plate 92 in the axial direction. The clutch surface 93a is centered on the rotation axis of the second clutch plate 93,
The clutch surface 9 of the first clutch plate 92 is formed so as to extend along a plane orthogonal to the rotation axis and in the rotation axis direction.
2a. Clutch surface 93
Similarly to the clutch surface 92a, a plurality of ridges 93b extending radially around the rotation axis are formed at the same angle as the number of the ridges 92b. Each ridge 93b
Like the protruding ridge 92b, is formed in a tapered cross-section, the width of which becomes narrower toward the top, and has a pair of tapered surfaces 93c.

As shown in FIGS. 8 (a) and 8 (b), the ridges 92b and 93b provided on the clutch surfaces 92a and 93a, respectively, when the two clutch plates 92 and 93 are brought close to the rotation axis direction. The tapered surfaces 92c and 93c are in contact with each other, and engage so as to restrict the relative rotation of the input-side rotator 41 and the rotary shaft 43 and to rotate integrally. Also, the tapered surfaces 92c, 93
The protrusions 92b and 93b with which the c contact each other engage so as to limit the play in the rotation direction of the input side rotating body 41 and the rotating shaft body 43 as the two clutch surfaces 92a and 93a come closer to each other. . Furthermore, each ridge 92b, 9
3b is formed so that when the two clutch plates 92 and 93 approach the end, the input side rotating body 41 and the rotating shaft body 43 are engaged until they do not rotate relative to each other.

Each of the compression coil springs 91 urges the first clutch plate 92 in the direction of the rotation axis and holds the first clutch plate 92 in the state of being completely engaged with the second clutch plate 93. In a state where power is supplied, the electromagnetic coil 88 attracts the first clutch plate 92 via the yoke 87 and the support member 90, and pushes the first clutch plate 92 against the urging force of each compression coil spring 91 to rotate the first clutch plate 92 with the rotating portion 86. To the flange 95 side. Then, the first clutch plate 9
2 is held at a position where its clutch surface 92a does not engage with the clutch surface 93a of the second clutch plate 93. In a state where power is not supplied, the electromagnetic coil 88 does not attract the first clutch plate 92, and moves the first clutch plate 92 in a direction away from the flange 95 by the urging force of each compression coil spring 91. Then, the first clutch plate 92
At a position where its clutch surface 92a engages with the clutch surface 93a of the second clutch plate 93.

The clutch device 84 thus configured
When the power is supplied from the electronic control unit (not shown) to the electromagnetic coil 88, the first clutch plate 92 is not engaged with the second clutch plate 93, and the relative rotation of the rotating shaft 43 with respect to the input side rotating member 41 is prevented. Tolerate. On the other hand, when power is no longer supplied to the electromagnetic coil 88, the first clutch plate 92 is engaged with the second clutch plate 93, and the rotation shaft 43 and the input-side rotator 41 are directly connected to prohibit relative rotation.

In the clutch device 84, when the two clutch plates 92 and 93 are engaged, the magnitude of the external force applied to rotate the input side rotating body 41 and the rotating shaft body 43 relative to each other is an allowable value. Is exceeded, the two clutch plates 92, 93 are temporarily disengaged from the engaged state against the urging force of each compression coil spring 91. Then, relative rotation between the input-side rotating body 41 and the rotating shaft body 43 is allowed.
When an external force is applied to rotate the clutch plates 92 and 93 in the engaged state relative to each other, the clutch plates 92 and 93 are interposed between the tapered surfaces 92c and 93c of the ridges 92b and 93b engaged with each other. In the direction of the rotation axis to generate a component force in the direction.

Further, as shown in FIG. 4, the steering device 10 is provided with an electric motor 96 for driving the rotary shaft 43 to rotate relative to the input rotary body 41. The electric motor 96 is an inner rotor type DC brushless motor, and includes a rotor magnet 68 fixed to the sleeve 58, a stator provided in the motor case 17, and the like. The stator includes a stator core 97, an electromagnetic coil 98, and the like. And the electric motor 96
The rotation direction and the rotation speed are controlled by an electronic control unit (not shown) based on the vehicle condition such as the rotation position and the vehicle speed of the steering shaft 12 and the output shaft 13.

The electronic control unit controls the output shaft 1 with respect to the rotation angle of the steering shaft 12 based on the vehicle condition.
When the rotation angle of the rotating member 3 is one-to-one, the input-side rotating body 41
The electric motor 96 is controlled so that the rotating shaft 43 is not relatively rotated. Further, based on the vehicle condition, the output shaft 13 with respect to the rotation angle of the steering shaft 12 is determined.
In order to further increase the rotation angle of
The electric motor 96 is controlled so that the rotating shaft 43 rotates relatively faster in the same direction. Conversely, when making the rotation angle of the output shaft 13 smaller than the rotation angle of the steering shaft 12, the electric motor 96 is controlled such that the rotation shaft 43 rotates faster in the reverse direction with respect to the input rotation body 41.

The steering apparatus 10 configured as described above operates as follows. The steering device 10 controls the electric motor 9 so that the rotation shaft 43 does not rotate relative to the input-side rotator 41 when the input-side rotator 41 rotates with the steering.
When the steering wheel 6 is controlled, the rotation of the steering shaft 12 due to the steering of the steering wheel is output from the output shaft 13 at a rotation ratio of “1”.

Further, the steering device 10 controls the electric motor 96 so that the rotating shaft 43 rotates relative to the input rotating body 41 when the input rotating body 41 rotates with steering.
Is controlled, the output shaft 13 outputs a rotation obtained by adding a rotation based on a relative rotation of the rotating shaft 43 with respect to the input-side rotator 41 to the rotation of the input-side rotator 41.

When the rotating shaft 43 is driven to rotate relative to the input-side rotator 41 in the same direction, the rotation of the input-side rotator 41 according to the steering is set to "1". The output is outputted from the output shaft 13 at a larger rotation ratio. At this time, the steering device 10 is
The output from the output shaft 13 is increased at a higher rotation ratio as the relative rotation speed of the rotating shaft 43 with respect to 1 is higher.
Therefore, according to the vehicle condition, the input-side rotator 4 by steering is set.
When the electric motor 96 is controlled such that the rotation shaft 43 relatively rotates at a higher relative speed in the same direction for one rotation, the steering angle of the steered wheels with respect to the steering angle of the steering wheel is made larger.

On the contrary, when the rotating shaft 43 is driven to rotate relative to the input-side rotator 41 in the opposite direction, the steering device 10 rotates the input-side rotator 41 in accordance with the steering. The output is output to the output shaft 13 at a rotation ratio smaller than “1”. At this time, the steering device 10 outputs from the output shaft 13 with a smaller rotation transmission ratio as the relative rotational speed of the rotating shaft body 43 in the reverse direction with respect to the input rotating body 41 increases. Therefore, when the electric motor 96 is controlled such that the rotation shaft 43 relatively rotates at a relatively higher speed in the reverse direction with respect to the rotation of the input-side rotation body 41 due to the steering, the steering wheel is steered. The steering angle of the steered wheels with respect to the angle is made smaller.

The operation of the present embodiment configured as described above will be described. In a state where power is supplied to the electromagnetic coil 88 during operation of the vehicle, the first clutch plate 92 is not engaged with the second clutch plate 93. For this reason,
Input side rotating body 41 of rotating shaft body 43 by electric motor 96
Relative rotation to the steering shaft 1
The rotation ratio of the output shaft 13 to 2 is controlled according to the vehicle situation. Therefore, the steering angle of the steered wheels with respect to the steering angle of the steering wheel is controlled according to the vehicle condition.

When a failure occurs in the electric system of the vehicle and power is not supplied to the electric motor 96 and the electromagnetic coil 88, as shown in FIG. It moves from the 95 side to the second clutch plate 93 side.

The first clutch plate 92 is connected to the second clutch plate 93
8A, the tapered surface 92c of each ridge 92b provided on the clutch surface 92a, as shown in FIG.
And the tapered surface 93c of each ridge 93b provided on the clutch surface 93a abuts. Then, the ridges 92b and the ridges 93b mesh with each other to engage so as to limit the relative rotation between the input-side rotator 41 and the rotary shaft 43. At this time, since the protruding ridges 92b, 93b are formed in a tapered cross-section having a width narrower toward the top, the tapered surfaces 92c, 93c of the protruding ridges 92b, 93b easily come into contact with each other. For this reason, the rotational angle relationship between the input side rotating body 41 and the rotating shaft body 43 when the two ridges 92b and 93b start to be engaged is not limited to a specific rotational angle relationship as in the steering device in the related art. , Ridges 92b, 93b are tapered surfaces 92c, 9
It is expanded to a wider range except for a state where the members 3c do not contact each other.

Once the ridges 92b, 93b are engaged with each other once, the two ridges 92b, 93b mesh deeper with the tapered surfaces 92c, 93c in contact with each other, so that the input side rotary body 41 and the rotating shaft body are engaged. And 43 rotate relative to each other. Then, the protrusions 92b, 93b
The positional relationship between them in the rotation direction has been corrected, and the ridges 92b,
93b are engaged with each other so as to mesh more deeply. At this time, the more the protruding ridges 92b and 93b mesh with each other,
The protrusions 92b and 93b are more likely to interfere with each other, and the size of the relative rotation between the input-side rotating body 41 and the rotating shaft body 43 becomes smaller.

Further, in a state where the two clutch plates 92 and 93 are close to each other in the direction of the rotation axis, as shown in FIG. 8B, the ridges 92b and 93b do not mesh with each other further, so that the input side The rotating body 41 and the rotating shaft body 43 are connected in a state where they do not rotate relative to each other.

Accordingly, the ridges 9 of both clutch plates 92 and 93 are provided.
In the state where 2b and 93b are engaged and engaged to the end,
The rotation ratio is fixed while the play between the steering shaft 12 and the output shaft 13 is small.

Also, an excessive external force may be applied to the connected input-side rotating body 41 and rotating shaft body 43 so as to relatively rotate both members from the steering wheel side, for example.
In this case, the tapered surfaces 92c, 93c of the ridges 92b, 93b abutting each other between the two clutch surfaces 92a, 93a.
Then, a component force is generated in a direction to separate the two clutch plates 92 and 93 in the rotation axis direction. For this reason, both clutch plates 29,
93 is disengaged from the engaged state against the urging force of each compression coil spring 91, and relatively rotates the input side rotating body 41 and the rotating shaft body 43. For this reason, no further excessive external force is applied to the input side rotating body 41, the output side rotating body 42, the rotating shaft body 43 and the carrier 44.

When the external force applied to the input side rotating body 41 and the rotating shaft body 43 is not excessively large, the urging force of the compression coil spring 91 brings the clutch plates 92 and 93 into a state of being engaged again, and the input side rotating body 41 and the rotating shaft 43 are connected again without relative rotation.

In a state where the power supply to the clutch device 84 is stopped and both clutch plates 92 and 93 are engaged, a force for rotating the input side rotating body 41 and the rotating shaft body 43 relative to each other is applied. There are situations in which they are joining. At this time, when power is supplied to the electromagnetic coil 88, the clutch plates 92 and 93 are easily disengaged from the engaged state due to a component in the rotation axis direction generated between the tapered surfaces 92c and 93c of the projections 92b and 93b. Therefore, even when external power is applied from the steering wheel or the steered wheels when the power supply to the clutch device 84 is stopped, when the power supply to the electromagnetic coil 88 is restarted, the input side rotating body 41 Rotating shaft 43
The connection state with is quickly released.

According to the above-described embodiment, the following effects can be obtained. (1) Each ridge 92b, 93 of both clutch plates 92, 93
The relative rotation between the input-side rotator 41 and the rotary shaft 43 is limited to a smaller value as b is more deeply meshed. Therefore, when the rotation ratio between the steering shaft 12 and the output shaft 13 is fixed, the clutch plates 92 and 93 can be reliably and smoothly engaged. Further, the rotation ratio can be fixed in a state where the two shafts 12 and 13 are not relatively rotated, and in the fixed state, the two shafts 12 and 13 are not rotated.
13 can be made smaller. As a result, the rotation ratio can be fixed quickly, and the operating feeling of the steering wheel can be prevented from further deteriorating in the state where the rotation ratio is fixed.

When the torque is applied, each ridge 9
Since a force in the direction of disengagement is generated between 2b and 93b, both clutch plates 92 and 93 can be reliably and smoothly disengaged from the engaged state. As a result, the state in which the rotation ratio is fixed can be quickly released.

(2) Clutch surface 92 of clutch plate 92
a, a plurality of ridges 92 b having a tapered cross section provided so as to extend in the forming direction all around
The input side rotating body 41 and the rotating shaft body 43 are directly connected to each other by a plurality of ridges 93b similarly provided on the entire circumference of a. Further, as the protruding ridges 92b and the protruding ridges 93b are more deeply engaged with each other, the angle at which the input-side rotator 41 and the rotary shaft 43 can relatively rotate is limited to a smaller angle. For this reason,
A plurality of protrusions 92b, 93 of each clutch surface 92a, 93a
Since the two clutch plates 92 and 93 can be engaged by making the b contact each other long in the radial direction with respect to the rotation shaft, the load applied to each of the ridges 92b and 93b can be reduced.

Accordingly, since it is not necessary to increase the height (height in the direction of the rotation axis) of each of the protrusions 92b, 93b, it is possible to prevent the two clutch plates 92, 93 from increasing in the direction of the rotation axis. . As a result, an increase in the size of the clutch device 84 in the rotation axis direction can be suppressed.

(3) The clutch plates 92 and 93 provided with the ridges 92b and 93b are formed so as to be engaged until the input side rotating body 41 and the rotating shaft 43 do not rotate relative to each other. Therefore, in a state where both clutch plates 92 and 93 are fully engaged in the rotation axis direction, the play of the connected input side rotation body 41 and rotation shaft body 43 is minimized. Accordingly, the play between the steering shaft 12 and the output shaft 13 having a fixed rotation ratio can be reduced, so that the operating feeling of the steering wheel with the rotation ratio fixed is not further reduced. be able to.

(4) Since only the first clutch plate 92 is operated to move and the second clutch plate 93 is fixed to the input side rotating body 41, both clutch plates 92 and 93 are moved in the direction of the rotation axis. As a result, the structure is simplified as compared with a configuration in which engagement and non-engagement are switched.

(5) Since the first clutch plate 92 is switched between a position where the first clutch plate 92 is not engaged with the second clutch plate 93 and a position where the first clutch plate 92 is engaged with the single electromagnetic coil 88 and the compression coil spring 91, only the electromagnetic coil is used. Thus, the structure is simplified as compared with the configuration in which the engagement state is switched.

(6) Since the electromagnetic coil 88 is provided on the case body 11, the electromagnetic coil 88 does not rotate with steering. Therefore, a complicated power supply device such as a slip ring is not required.

(7) If the magnitude of the external force applied to rotate the input-side rotator 41 and the rotary shaft 43 relative to each other when both clutch plates 92 and 93 are engaged is excessive, the compression is performed. The two clutch plates 92 and 93 are separated from each other in the rotation axis direction against the urging force of the coil spring 91. Since the relative rotation between the input side rotating body 41 and the rotating shaft body 43 is allowed, an excessive force is applied to the input side rotating body 41, the output side rotating body 42, the rotating shaft body 43, and the carrier 44. Absent.

Therefore, it is not necessary to provide each transmitter with a strength enough to withstand an excessive external force that is temporarily applied such as an excessive reverse input, so that higher reliability can be ensured. Therefore, the size of the steering device 10 can be reduced. Further, in a state in which no excessive external force is applied, the two clutch plates 92 and 93 are immediately engaged, so that the steering function can be recovered instantaneously.

Next, embodiments other than the above-described embodiment will be described in a bulleted form. In the above embodiment, the snap ring 81 and the plate 82 made of a non-magnetic material may not be used.

In the above embodiment, each ridge 92b, 93
As shown in FIG. 9, the cross-sectional shape of b may be a tapered shape with a sharp top. In this case, as shown in FIG. 10A, the projections 92b and 93b start to engage with each other from the top. Then, as shown in FIG. 10 (b), as the two clutch surfaces 92a, 93a come closer to each other in the rotation axis direction, the ridges 92b, 93b engage so as to mesh more deeply. Accordingly, the rotation angle relationship between the rotating shaft 43 and the input-side rotator 41 is corrected, and the input-side rotator 41 is changed.
And the rotating shaft body 43 are connected so as not to rotate relative to each other.

Therefore, the rotational angle relationship between the input side rotary body 41 and the rotary shaft body 43 with which the clutch plates 92 and 93 can be engaged is expanded to a wider range, and the input side rotary body 41 and the rotary shaft The body 43 is connected in a state where it does not relatively rotate. Therefore, in a state where the rotation ratio is fixed, the play between both shafts 12 and 13 can be further reduced.

In the above embodiment, the circumferential distance between the ridges 92b provided on the clutch surface 92a and the clutch surface 93
The interval in the circumferential direction of the ridge 93b provided at a is increased. Then, in a state in which the protrusions 92b and 93b are meshed to the end, the input side rotating body 41 and the rotating shaft body 43 may be connected to each other until they are relatively rotated by a slight angle.

In the above embodiment, each clutch surface 92
The protrusions 92b and 93b provided on the a and 93a are not limited to those formed to extend radially around the rotation axis, but are formed in a spiral shape extending substantially radially about the rotation axis. There may be. In this case, also in this case, the cross section of each of the ridges 92b and 93b is substantially tapered.

In the above embodiment, each clutch plate 92,
The clutch surfaces 92a and 93a of the 93 may be annular curved surfaces along the surface of the cone with the rotation axis as the central axis. In the above embodiment, one of the clutch surfaces 92a (93a) of the two clutch plates 92 and 93 is provided with a ridge 92b.
(93b) may not be provided over the entire circumference.

In the above embodiment, the second clutch plate 93 is supported by the input-side rotating body 41 so as to rotate integrally with the second clutch plate 93 and to be movable in the rotation axis direction. Then, the second clutch plate 93 supported by the input-side rotator 41 is formed by an electromagnetic coil provided on the input-side rotator 41 and a plurality of compression coil springs.
The position is switched between a position closer to the first clutch plate 92 and a position farther away. On the other hand, the first clutch plate 92 supported by the support member 90 is moved to a position further away from the first clutch plate 92 and a position closer to the first clutch plate 92 by the electromagnetic coil 88 and each compression coil spring 91. Switching is performed at a position where the second clutch plate 93 is disposed.

In the above embodiment, the rotating shaft 43 is supported outside the input-side rotating body 41, and two rows of planetary gear mechanisms are provided outside the input-side rotating body 41. And the rotating shaft 43
Is engaged with a second clutch plate 93 fixed to the output-side rotator 42 to connect the rotary shaft 43 and the output-side rotator 42 so that they cannot rotate relative to each other. Is also good.

[0087]

According to the first to sixth aspects of the present invention, when the rotation ratio between the input side rotator and the output side rotator is fixed, the input side rotator and the output side rotator are connected. It is possible to prevent the relative rotation between the rotating bodies and to prevent the relative rotation between the rotating bodies even in the fixed state. Further, since the clutch also has a torque limit function of releasing the engagement of the clutch with an excessive external force, the size of the apparatus can be reduced.

[Brief description of the drawings]

FIG. 1 is a schematic cross-sectional view of a main part including a clutch device of a steering device according to an embodiment.

FIG. 2 is a schematic side view of a steering device.

FIG. 3 is a schematic sectional view of an input side portion of the steering device.

FIG. 4 is a schematic cross-sectional view of the output side portion.

FIG. 5 is a schematic front view of a first clutch plate.

FIG. 6 is a schematic front view of a second clutch plate.

FIG. 7 is a schematic diagram showing an operation state of both clutch plates.

FIG. 8A is a schematic diagram showing an initial state of meshing, and FIG. 8B is a schematic diagram showing a state of completion of meshing.

FIG. 9 is a schematic view showing an operation state of both clutch plates according to another embodiment.

FIG. 10A is a schematic diagram illustrating a state at the beginning of meshing, and FIG. 10B is a schematic diagram illustrating a state at the time of meshing completion.

11A is a schematic longitudinal sectional view showing a conventional clutch device of a steering device, and FIG. 11B is a schematic plan sectional view of a main part of the same.

FIG. 12A is a schematic longitudinal sectional view showing a conventional clutch device of a steering device, and FIG. 12B is a schematic plan sectional view of a main part of the same.

[Explanation of symbols]

DESCRIPTION OF SYMBOLS 10 ... Vehicle steering apparatus, 11 ... Case body as a non-rotating part, 12 ... Steering shaft as an input side rotating body, 13 ... Output shaft as an output side rotating body, 40 ...
A rotation ratio variable mechanism, 41: an input side rotating body as a rotation transmitting body and a second transmitting body; 42, an output side rotating body as a rotation transmitting body; 43, a rotating shaft body as a rotation transmitting body and a first transmitting body; 44: a carrier as a rotation transmitting body, 64: a sun gear, 74: an input-side planetary gear, 75: an output-side planetary gear, 84: a clutch device as a transmission ratio fixing device, 87: a yoke constituting switching means, 88 ... Electromagnetic coil which constitutes connection operation means and switching means, 90 ... Support member as support means which constitutes connection operation means, 91
··· Compression coil spring as urging means constituting the connecting operation means and switching means · 92 · First clutch plate as first connecting means · 92a · Clutch surface as engaging surface · 92b
... a ridge, 93 ... a second clutch plate as a second connecting means,
93a: clutch surface as engagement surface, 93b: ridge, 9
6 ... Electric motor.

Claims (6)

[Claims] An input-side rotator to which rotation by steering is input, an output-side rotator for outputting rotation corresponding to the rotation input to the input-side rotator, and an input to the input-side rotator And a rotation ratio variable mechanism having a plurality of rotation transmission members for transmitting the rotation to the output side rotation member. The rotation ratio variable mechanism is configured such that one of the rotation transmission members is rotationally controlled by an electric motor. A vehicle steering device capable of adjusting a rotation ratio of an output-side rotator to an input-side rotator, wherein first connecting means provided integrally rotatable with a first transmission body, which is one of the rotation transmission bodies. A second transmission member rotatably supported on a second transmission member rotatably supported on the same rotation axis as the first transmission member, the second transmission member being one of the rotation transmission members excluding the first transmission member. Connecting means, wherein the first connecting means and the second connecting means are And the two transmission bodies are connected so as to be integrally rotatable, and are engaged so that the relative rotation of the two transmission bodies becomes smaller as they approach each other in the direction of the rotation axis. The transmission ratio fixing device of the device. 2. The first connecting means and the second connecting means each include an engaging surface facing each other in the rotation axis direction and a plurality of ridges provided on the engaging surface. Is provided so as to extend from the inner peripheral side to the outer peripheral side with respect to the rotation shaft, and has a substantially tapered cross section whose width becomes narrower toward the top, and wherein the first connection means and the second connection means The tapered surfaces of the ridges provided on the respective engaging surfaces abut each other to connect the two transmission members so as to be integrally rotatable, and to make the relative rotation of the two transmission members smaller as they come closer in the rotation axis direction. The transmission ratio fixing device for a vehicle steering system according to claim 1, wherein the transmission ratio fixing device is engaged with the transmission ratio. 3. An at least one of the first connection means and the second connection means is moved in the direction of the rotation axis, and both engagement surfaces are engaged from a non-engagement position where the two connection means are not engaged. The transmission ratio fixing device for a vehicle steering system according to claim 1 or 2, further comprising a coupling operation means disposed at an engagement position. 4. The connecting operation means is provided so as to be integrally rotatable with the first transmitting body and supports the first connecting means so as to be movable in the rotation axis direction. Switching means for switching the first connection means with respect to the support means in the direction of the rotation axis, wherein the switching means is a second fixing means fixed to the second transmitting body.
The transmission ratio of the vehicle steering system according to claim 3, wherein the vehicle is switched to one of a non-engagement position that does not engage with the coupling means and an engagement position that engages with the second coupling means. Fixing device. 5. The switching means is provided on the support member and urges the first connection means with an elastic force to hold the first connection means engaged with the second connection means. 5. An electromagnetic coil according to claim 4, further comprising: an electromagnetic coil that moves the first connection unit against the urging force of the urging unit and holds the first coupling unit so as not to engage with the second coupling unit. Transmission ratio fixing device for vehicle steering system. 6. The two connecting means, wherein the urging means is a first
When the connecting means is biased and held in a state of being engaged with the second connecting means, an external force applied to rotate the two transmitting bodies relative to the first transmitting body and the second transmitting body. 6. The device according to claim 5, wherein when the size exceeds an allowable value, the two transmission members are engaged with each other while being spaced apart in the direction of the rotation axis against the urging force of the urging means. A transmission ratio fixing device for a vehicle steering system according to claim 1.