HK1179673A - Phase variable device for engine - Google Patents

Description

Phase variable device of engine

Technical Field

The present invention relates to a phase variable device of an engine for an automobile, which is a phase variable device of an engine for an automobile provided with a self-lock mechanism for preventing an assembly angle shift caused by disturbance torque from a valve side in a phase variable mechanism for changing an assembly angle (relative phase angle) between a crankshaft and a camshaft to change an opening/closing timing of a valve.

Background

As a phase variable device of an engine in which a self-lock mechanism for preventing a deviation of an assembly angle due to a disturbance torque from a valve side is provided in a phase variable mechanism for changing an assembly angle (relative phase angle) between a crankshaft and a camshaft to change an opening/closing timing of a valve, there is a phase variable device of an engine shown in patent document 1 below. In the device of patent document 1, a four-link mechanism 108 for four-link operation of the eccentric centers of a plurality of eccentric circular members (an eccentric circular cam 110, a first link 111, and a second link 112) provided continuously at predetermined positions around the central axis of a camshaft is configured, and an assembly angle between the camshaft and a driving rotating body 101 operating on the crankshaft side is changed by operating the four-link mechanism 108 via a first or second control rotating body (102, 103) braked by a first or second electromagnetic clutch (105, 106).

The four-link mechanism 108 includes an eccentric circular cam 110 integrated with the camshaft, a first link 111 supported by the eccentric circular cam 110 so as to be eccentrically rotatable, and a second link 112 supported by the first link 111 so as to be eccentrically rotatable, and is interlocked with either the first or second control rotating bodies (102, 103) when the brake is applied, and eccentrically rotates about each support shaft, thereby changing the relative phase angle between the camshaft and the crankshaft (driving rotating body 101) to the advance angle side or the retard angle side.

On the other hand, when a relative rotational torque (this torque is referred to as disturbance torque) with respect to the driving rotor 101 occurs in the camshaft by the reaction from the valve spring, the first link 111 is pressed against the guide groove 113 of the first link provided in the drive cylinder 115 of the driving rotor 101, whereby the eccentric circular members (110 to 112) are held so as not to be eccentrically rotated, and the deviation of the assembly angle between the camshaft and the driving rotor 101 (crankshaft) is prevented. As described above, the phase variable device of the engine of patent document 1 has a self-locking mechanism that prevents an angular displacement between a camshaft and a crankshaft due to a disturbance torque.

Documents of the prior art

Patent document

Patent document 1 PCT/JP2009/60327

Disclosure of Invention

Problems to be solved by the invention

The self-locking mechanism provided in the phase variable device of the engine of patent document 1 is configured by the four-bar linkage 108, and it is necessary to realize the self-locking structure while maintaining the operation accuracy of the four-bar linkage 108. Therefore, from the viewpoint of realizing the self-locking mechanism, it can be said that the structure is complicated and the manufacturing cost is high, and therefore, it is desired to realize a simpler self-locking mechanism.

Accordingly, the phase variable device for an engine according to the present invention provides a phase variable device for an engine having a self-lock mechanism which has a simpler structure than conventional ones and which can be easily and inexpensively implemented.

Means for solving the problems

The phase varying device of the engine according to claim 1 includes: a driving rotator driven by the crank shaft; a control rotating body; a camshaft that supports the driving rotating body coaxially and relatively rotatably; a rotational operation force applying mechanism that applies a relative rotational torque to the control rotating body with respect to the driving rotating body; an assembly angle changing mechanism that changes an assembly angle of the camshaft and the driving rotary body in accordance with relative rotation of the control rotary body with respect to the driving rotary body; and a self-locking mechanism provided on the assembly angle changing mechanism for preventing the deviation of the assembly angle between the driving rotating body and the camshaft caused by the cam torque; the self-locking mechanism is provided with an eccentric circular cam, a locking plate and a cylindrical part; the eccentric circular cam is integrated with the camshaft; the lock plate has a holding groove for holding the outer periphery of the eccentric circular cam from both sides on the eccentric side of the center axis of the camshaft in the eccentric direction from the center axis of the camshaft toward the cam center of the eccentric circular cam, and a coupling mechanism; a coupling mechanism for transmitting the relative rotational torque from the control rotating body to the eccentric circular cam; the cylindrical portion is formed integrally with the driving rotating body and inscribes the outer periphery of the lock plate.

When a plurality of disturbance torques are inputted to the camshaft from the valve, the lock plate rotating integrally with the camshaft receives a force in a substantially radial direction through the holding groove holding the eccentric circular cam integrally with the camshaft so as not to be eccentrically rotatable, and is pressed against the cylindrical portion of the driving rotating body. As a result, the driving rotor and the camshaft driven by the crankshaft are held by the disturbance torque so as not to be relatively rotatable, and therefore, the assembly angle of the driving rotor and the camshaft is held without being displaced by the disturbance torque.

Further, claim 2 is the phase variable device of the engine according to claim 1, wherein the holding groove is formed to extend in a radial direction of the lock plate, and has a lock plate bush attached to an outer periphery of the eccentric circular cam, and the lock plate bush has a pair of flat surfaces on the outer periphery thereof, the flat surfaces being provided on both right and left sides across the eccentric direction, and being sandwiched by the holding groove.

The eccentric circular cam is held in the holding groove via the lock plate bush, and the lock plate bush is brought into surface contact with the holding groove via the pair of flat surfaces, whereby the contact stress generated in the holding groove is reduced as compared with the case where the eccentric circular cam is directly brought into line contact with the holding groove, and therefore, the lock plate and the eccentric circular cam are held without causing uneven wear at the contact portion. As a result of the prevention of the rattling, the pressing force of the lock plate against the cylindrical portion of the driving rotary member at the time of the occurrence of the disturbance is instantaneously and reliably generated.

Further, claim 3 is directed to the phase variable device of the engine of claim 2, wherein the lock plate is divided into 2 parts by a pair of slits formed from the holding groove toward an outer peripheral surface of the lock plate.

When the eccentric circular cam of the camshaft is brought into surface contact with the holding groove of the lock plate via the lock plate bush, the torque for rotating the lock plate relative to the cylindrical portion becomes dominant as compared with the force for pressing the lock plate against the cylindrical portion of the driving rotating body in the substantially radial direction when the disturbance torque is generated, and the self-locking function may be difficult to function. When the lock plate is divided into 2 parts by the slit extending from the holding groove to the outer peripheral surface, the relative rotational torque generated in one lock plate is not transmitted to the other lock plate by the cutting. Therefore, when the disturbance torque occurs, the relative rotational torque generated in the lock plate is reduced, and the pressing force of the lock plate against the drive rotary body cylindrical portion at the time of the disturbance can be increased.

Further, claim 4 is directed to the phase variable device of the engine recited in claim 3, wherein a biasing mechanism that applies an elastic force in a direction in which a width of the slit is expanded to the lock plate divided into 2 parts is provided on one of the slits.

An elastic force for expanding the slit is applied to one side of the slit, and thus a gap between the lock plate and the cylindrical portion of the driving rotating body and a gap between the lock plate bushing and the holding groove, which are caused by a manufacturing error or the like, become smaller, and thus, the rattling of each member at the time of the occurrence of self-locking is reduced. That is, the pressing force of the lock plate against the cylindrical portion of the driving rotary body when the disturbance occurs can be instantaneously generated.

Further, claim 5 is directed to the phase variable device of the engine recited in claim 2, wherein the lock plate is provided with a slit that opens in a direction from the holding groove toward an outer peripheral surface of the lock plate, and an outer diameter of the lock plate on both left and right sides with respect to the eccentric direction is formed slightly larger than an inner diameter length of the inscribed cylindrical portion.

And an outer diameter of the lock plate is slightly larger than an inner diameter of the cylindrical portion, and the lock plate is inscribed inward from the cylindrical portion. As a result, the gap between the lock plate and the cylindrical portion of the driving rotating body and the gap between the lock plate bushing and the holding groove due to manufacturing errors and the like become smaller. That is, according to this configuration, as in claim 4, the rattling of the members at the time of the self-locking can be reduced, and the pressing force of the lock plate against the cylindrical portion of the driving rotating body at the time of the disturbance can be instantaneously generated.

Further, claim 6 is the phase variable device for an engine described in claim 4 or 5, wherein the lock plate bushing is divided into 2 parts by a pair of slits.

According to claim 6, since the urging means applies the elastic force to the lock plate bush through the lock plate in the state where the lock plate bush is divided, the clearance between the lock plate bush and the eccentric cam, which is inevitably generated without dividing the lock plate bush, can be made smaller, and thus the rattling of each member at the time of the occurrence of the self-locking can be further reduced. That is, the pressing force of the lock plate against the cylindrical portion of the driving rotary body at the time of occurrence of the disturbance can be generated more instantaneously. In addition, the dimensional accuracy of the eccentric circular cam and the lock plate bush can be relaxed, and therefore, the manufacturing cost is suppressed.

Further, claim 7 is the phase variable device of the engine according to any one of claims 2 to 6, wherein the pair of flat surfaces of the lock plate bush are formed as a pair of stepped surfaces protruding leftward and rightward with the eccentric direction therebetween, and the pair of stepped surfaces are provided on an eccentric side with respect to a cam center of the eccentric circular cam in the eccentric direction.

The rattling caused by the manufacturing error occurs strictly speaking between the holding groove and the lock plate bush. When the flat surface is formed in a stepped shape and the contact position of the stepped flat surface is arranged at a position eccentric to the cam center of the eccentric circular cam with respect to the center of the camshaft, the arc-shaped moving distance to the flat surface and the holding groove is reduced when the disturbance torque is generated, as compared with the case where the flat surface having no step is directly brought into contact with the holding groove. In other words, the sloshing is further reduced. That is, the pressing force of the lock plate against the cylindrical portion of the driving rotary body can be generated more instantaneously when the disturbance occurs.

Claim 8 is the phase variable device according to any one of claims 1 to 7, wherein the coupling mechanism is formed by a pair of coupling holes provided in the control rotating body and the lock plate, and a coupling member that engages with both of the coupling holes, and a minute gap is formed between the coupling hole and the coupling member on either the control rotating body side or the lock plate side.

In the case where the positional relationship between the control rotating body and the lock plate is strongly excessively restrained, sometimes the lock plate becomes difficult to be pressed against the cylindrical portion of the driving rotating body when a disturbance occurs due to a manufacturing error. If a small gap is provided between one of the coupling holes and the coupling member, the movement of the lock plate in the substantially radial direction is less likely to be restricted, and therefore, the pressing force of the lock plate against the cylindrical portion of the driving rotary body when the interference occurs can be increased.

ADVANTAGEOUS EFFECTS OF INVENTION

According to the phase variable device of the engine according to claim 1, the self-lock mechanism can be easily provided at low cost by realizing a simpler structure than the conventional one, such as the cylindrical portion of the driving rotating body, the disc-shaped lock plate, and the holding groove.

According to the phase variable device for an engine of claim 2, the durability of the self-lock mechanism is improved, and the self-lock function is more reliably exhibited.

According to the phase variable device of the engine of claims 3 to 8, the self-locking function is exerted more reliably.

Drawings

Fig. 1 is an exploded perspective view of a phase variable device 1 according to an embodiment of the present invention, as viewed from the front of the device.

Fig. 2 is an exploded perspective view of fig. 1 viewed from the rear of the apparatus.

Fig. 3 is a front view of embodiment 1 (with the cover 70 removed).

Fig. 4 is a sectional view a-a of fig. 3.

Fig. 5 is a cross-sectional view E-E of fig. 4.

Fig. 6 (a) is a sectional view B-B of fig. 4. (b) Is a cross-sectional view C-C of fig. 4. (c) Is a cross-sectional view taken along line D-D of fig. 4.

Fig. 7 is an explanatory view of the self-locking mechanism of embodiment 1.

Fig. 8 is a sectional view of the self-lock mechanism of embodiment 2, corresponding to the portion E-E in fig. 4.

Fig. 9 is an explanatory view of a modification of the spring member of embodiment 2.

Fig. 10 is an explanatory view of a modification of the lock plate.

Fig. 11 is a sectional view of a portion corresponding to E-E in fig. 4 showing the 3 rd embodiment of the self-lock mechanism.

Detailed Description

Embodiments of the present invention will be described below with reference to the drawings. The phase variable device for an engine according to each embodiment is a device that is incorporated in an engine, transmits rotation of a crankshaft to a camshaft so as to open and close intake and exhaust valves in synchronization with the rotation of the crankshaft, and changes the timing of opening and closing the intake and exhaust valves of the engine according to an operating state such as a load or a rotation speed of the engine.

The structure of the apparatus of embodiment 1 will be described with reference to FIGS. 1 to 6. The phase variable device 1 of the engine according to embodiment 1 is composed of a driving rotating body 2 driven to rotate by a crankshaft, a first control rotating body 3 (a control rotating body according to claim 1), a camshaft 6 (fig. 4), a rotational operation force applying mechanism 9, an assembly angle changing mechanism 10, and a self-lock mechanism 11. In the following, the second electromagnetic clutch side in fig. 1 is referred to as the device front side, and the driving rotating body 2 side is referred to as the device rear side. The rotation direction of the driving rotor 2 around the camshaft center axis L0 as viewed from the front of the apparatus will be described as the advance-angle side D1 direction (clockwise direction), and the opposite direction to D1 will be referred to as the retard-angle side D2 direction (counterclockwise direction).

The driving rotor 2 is formed by integrating a sprocket 4 receiving a driving force from a crankshaft with a driving cylinder 5 having a cylindrical portion 20 by a plurality of bolts 2 a. The camshaft 6 shown in fig. 4 is coaxially and relatively non-rotatably integrated with the rear end side of the intermediate shaft 7 by inserting the bolt 37 into the central circular hole 7e of the intermediate shaft 7 and the female screw hole 6a in the front of the camshaft.

The first control rotor 3 has a flange portion 3a at the front edge, a cylindrical portion 3b continuing rearward, and a bottomed cylindrical shape continuing from a bottom portion 3 c. The bottom portion 3c has a through circular hole 3D having a center, a pair of pin holes 28, a circumferential groove 30 provided on a circumference having a predetermined radius from a center axis L0, and a curved reduced diameter guide groove 31 in which the distance from the center axis L0 to the groove decreases toward the advance angle side D1.

The intermediate shaft 7 has a first cylindrical portion 7a, a flange portion 7b, a second cylindrical portion 7c, an eccentric circular cam 12 having a cam center L1 eccentric from a camshaft center axis L0, and a third cylindrical portion 7d formed continuously in the axial direction from the rear side to the front side (the second control rotating member side in fig. 1, the same applies hereinafter). The driving rotor 2 is rotatably supported by the first and second cylindrical portions (7 a, 7 c) via circular holes (4 a, 5 a) on the intermediate shaft 7 and supported by the camshaft 6 via the intermediate shaft 7 in a state where the flange portion 7b is sandwiched between the sprocket 4 and the driving cylinder 5 which are integrated by the bolt 2 a. In addition, the third cylindrical portion 7d is inserted into the central circular hole 3d of the first control rotating body 3. The driving rotor 2, the first control rotor 3, the camshaft 6, and the intermediate shaft 7 are coaxially disposed on the central axis L0.

The turning operation force applying mechanism 9 is constituted by a first electromagnetic clutch 21 and a reversing mechanism 22, the first electromagnetic clutch 21 brakes the first control rotating body 3 to apply a relative turning torque to the driving rotating body 2, and the reversing mechanism 22 applies a relative turning torque in a direction opposite to the first electromagnetic clutch 21 to the first control rotating body 3.

The assembly angle changing mechanism 10 is a mechanism that integrates the camshaft 6 and the control rotating body 3 so as not to be relatively rotatable, and is composed of an intermediate shaft 7 that relatively rotatably supports the driving rotating body 2, a self-locking mechanism 11, and a coupling mechanism 16.

The self-lock mechanism 11 is interposed between the driving rotor 2 and the intermediate shaft 7, and prevents the camshaft 6 from being subjected to an interference torque from a valve spring not shown, thereby preventing the occurrence of an angular misalignment between the driving rotor 2 and the camshaft 6, and is configured by an eccentric circular cam 12 of the intermediate shaft 7, a lock plate bush 13, a lock plate 14, and a cylindrical portion 20 of the driving rotor 2.

As shown in fig. 1 and 5, the lock plate bush 13 has a circular hole 13a at the center thereof, which engages with the eccentric circular cam 12 of the intermediate shaft 7, has a pair of flat surfaces (23, 24) at both ends of the outer periphery thereof, and is rotatably attached to the outer periphery of the eccentric circular cam 12 such that the flat surfaces (23, 24) are substantially parallel to a straight line L2 (hereinafter, the same will be simply referred to as a straight line L2) connecting a cam shaft center axis L0 and a cam center L1.

The lock plate 14 is formed into a disk shape as a whole, and has a substantially rectangular holding groove 15 extending in the radial direction. The lock plate 14 is configured by a pair of components (14 a, 14 b) divided by a pair of slits (25, 26) or the like linearly extending from the short surfaces (15 a, 15 b) of the holding groove 15 toward the outer periphery of the lock plate 14. The flat surfaces (23, 24) of the lock plate bush 13 are held in contact with the long surfaces (15 c, 15 d) of the holding groove 15.

The lock plate 14 has its outer peripheral surfaces (14 c, 14 d) inscribed in the cylindrical portion 20 of the drive cylinder 5 in a state where the long surfaces (15 c, 15 d) of the holding groove 15 sandwich the flat surfaces (23, 24) of the lock plate bush 13. At this time, the outer periphery of the eccentric circular cam 12 is held in the holding groove 15 of the lock plate 14 via the lock plate bush 13, at a portion that is disposed on the eccentric side (in a direction eccentric from L0 to L1) with respect to a straight line L3 (hereinafter, the same will be simply referred to as a straight line L3) where the cam center L1 is orthogonal to the straight line L2.

The coupling mechanism 16 includes a pair of coupling pins (27, 27), a pair of first pin holes (28, 28) provided in the bottom portion 3b of the control rotating body 3, and second pin holes (29, 29) formed in the constituent members (14 a, 14 b) of the lock plate 14. The connecting pin 27 is fitted and fixed to one of the first pin hole 28 and the second pin hole 29, and is inserted into the other with a slight gap therebetween. When a disturbance torque occurs, the lock plate 14 is pressed against the inner circumferential surface 20a of the cylindrical portion 20 of the drive cylinder 5 by the self-lock mechanism 11 described later and is held so as not to be relatively rotatable. The minute gap provided in either one of the first and second pin holes (27, 28) into which the connecting pin 27 is inserted is provided in order to alleviate the phenomenon that the lock plate 14 fixed to the first control rotating body 3 is hard to be pressed against the inner peripheral surface 20a due to manufacturing errors.

The lock plate 14 inscribed in the cylindrical portion 20 of the drive cylinder 5 while holding the lock plate bush 13 is inserted into the first and second pin holes (28, 29) via the coupling pin 27, and is integrated with the control rotating body 3 so as not to be relatively rotatable. As a result, the intermediate shaft 7 (camshaft 6) is integrated with the control rotor 3 via the eccentric circular cam 12, the lock plate bush 13, and the lock plate 14 so as to be relatively non-rotatable.

The camshaft 6 is integrated with the control rotor 3 that receives the torque from the rotational operation force applying mechanism 9, and rotates relative to the driving rotor 2 in either the advance angle side D1 direction or the retard angle side D2 direction. As a result, the assembly angle of the camshaft 6 and the driving rotor 2 (crankshaft not shown) is changed, and the valve opening/closing timing is changed.

Here, the rotational operation force application mechanism 9 will be explained. The first electromagnetic clutch 21 is fixed inside an engine, not shown, and is disposed in front of the first control rotating body 3. The first control rotor 3 causes a rotational lag with respect to the driving rotor 2 rotating in the direction D1 by attaching the front surface 3e of the flange portion 3a to the friction member 21a of the first electromagnetic clutch 21.

The reversing mechanism 22 is constituted by the circumferential groove 30 and the diameter-reduced guide groove 31 of the first controlling rotating body 3, the second controlling rotating body 32, the disk-shaped pin guide plate 33, the second electromagnetic clutch 38 for braking the second controlling rotating body 32, the first and second connecting pins (34, 35), and the ring member 36.

The second control rotating body 32 is disposed inside the cylindrical portion 3b of the first control rotating body 3, and is rotatably supported by the third cylindrical portion 7d of the intermediate shaft 7 via a through circular hole 32a provided around the central axis L0. The second control rotating body 32 has a stepped eccentric circular hole 32b at the rear, the center O1 of which is eccentric from the camshaft center axis L0, and the ring member 36 is slidably and rotatably inscribed in the eccentric circular hole 32 b.

A disc-shaped pin guide plate 33 is disposed between the bottom portion 3c and the second controlling rotating body 32 inside the cylindrical portion 3b of the first controlling rotating body 3, and is rotatably supported on the third cylindrical portion 7d of the intermediate shaft 7 through a through-hole 33a in the center. In addition, the pin guide plate 33 has a substantially radial groove 33b and a substantially radial guide groove 33c extending in a substantially radial direction from a position not connected to the through circular hole 33 a. The substantially radial groove 33b is formed to penetrate from the vicinity of the through circular hole 33a to the outer peripheral edge at a position corresponding to the circumferential groove 30, and the substantially radial guide groove 33c is formed in an oblong shape to the vicinity of the outer peripheral edge at a position corresponding to the reduced diameter guide groove 31.

The first connecting pin 34 is formed of a thin circular shaft 34a and a hollow thick circular shaft 34b that is engaged with the tip of the thin circular shaft 34 a. The hollow thick circular shaft 34b is sandwiched by the substantially radial grooves 33b from both sides, and the rear end of the thin circular shaft 34a is inserted through the circumferential groove 30 and the holding groove 15 and fixed to the mounting hole 5b of the drive cylinder 5. The thin circular shafts 34a move in the groove direction at both ends of the circumferential groove 30.

The second connecting pin 35 is formed of a first member 35c formed by integrally forming a thick circular shaft 35b at the rear end of a thin circular shaft 35a, a hollow first shaft 35d, a hollow second shaft 35e, and a hollow third shaft 35 f. Hollow first to third shafts (35 d to 35 f) are inserted in order toward the thick circular shaft 35b into the thin circular shaft 35a to prevent the shafts from falling backward. And a round shaft 35b inserted into the holding groove 15. The hollow first shaft 35d has an arc shape along the diameter-reduced guide groove 31 in its outer peripheral shape, and is held vertically by the diameter-reduced guide groove 31 and moves along the diameter-reduced guide groove 31. The hollow second shaft 35e, which has a cylindrical shape, is held on both sides in the substantially radial guide groove 33c, and moves along the substantially radial guide groove 33 c. The hollow third shaft 35f has a cylindrical shape and is rotatably coupled to the circular hole 36a of the ring member 36.

Further, at the tip end of the third cylindrical portion 7d of the intermediate shaft 7, a retainer 39 and a washer 40 having circular holes (39 a, 40 a) at the center thereof are arranged from the front, and the retainer 39, the washer 40 and the intermediate shaft 7 are fixed to the camshaft 6 so as to be relatively non-rotatable by fitting bolts 37 inserted into the circular holes (39 a, 40 a) and the circular holes 7e into the female screw holes 6 a. As a result, the members from the driving rotor 2 to the second control rotor 2 of fig. 4 disposed on the outer periphery of the intermediate shaft 7 are fixed between the flange portion 6b of the camshaft 6 and the retainer 39 in a slip-off manner, and the axial gaps of these members are optimized by adjusting the thickness of the washer 40. A cover 70 is disposed in front of the bolts and the first and second electromagnetic clutches (21, 38).

Here, the operation of changing the assembly angle of the camshaft 6 and the driving rotor 2 (crankshaft not shown) by the rotational operation force applying mechanism 9 will be described. Normally, the first control rotor 3 is rotated in the direction D1 integrally with the driving rotor 2 (see fig. 6 c). When the first control rotating body 3 is attracted to and braked by the first electromagnetic clutch 21, the intermediate shaft 7 (the camshaft 6) generates a rotational lag in the D2 direction with respect to the driving rotating body 2 rotating in the D1 direction together with the integrated first control rotating body 3. As a result, the assembly angle of the camshaft 6 with respect to the driving rotor 2 (crankshaft, not shown) is changed toward the retarded angle side D2, and the opening and closing timing of the valve, not shown, is changed.

At this time, the hollow first shaft 35D of the second connecting pin 35 shown in fig. 6 (c) moves in the diameter-reduced guide groove 31 in the direction D3, which is substantially clockwise, the hollow second shaft 35e of fig. 6 (b) moves in the direction D4 toward the center axis L0 in the substantially radial guide groove 33c, and the hollow third shaft 35f of fig. 6 (a) applies a sliding rotational torque in the circular hole 32b to the ring member 36. The thin circular shaft 34a of the first linking pin 34 moves in the clockwise direction D1 in the circumferential groove 30. Further, both ends (30 a, 30 b) of the circumferential groove 30 function as stoppers against which the moving thin circular shaft 34a abuts.

On the other hand, the second control rotor 32 normally rotates in the direction D1 together with the driving rotor 2 (fig. 6 (a)). When the second electromagnetic clutch 38 is operated, the front surface 32c of the second control rotating body 32 is attracted to the friction member 38a, and a rotation delay occurs in the direction D2 with respect to the first control rotating body 3. The ring member 36 of fig. 6 (a) is eccentrically rotated in the direction D2 by the inscribed eccentric circular hole 32b, and is slidably rotated in the eccentric circular hole 32 b. The hollow second shaft 35e in fig. 6 (b) moves in the outer circumferential direction D5 along the substantially radial guide groove 33c together with the hollow third shaft 35f and the hollow first shaft 35D by the operation of the ring member 36. At this time, in the first control rotating body 3 of fig. 6 (c), contrary to the operation of the first electromagnetic clutch 21, the hollow first shaft 35D moving in the approximately half-hour direction D6 in the diameter reduction groove 31 receives the relative turning torque in the advance angle side D1 direction through the diameter reduction groove 31, and further rotates in the advance angle side D1 direction relative to the driving rotating body 2 rotating in the D1 direction. As a result, the assembly angle of the camshaft 6 with respect to the camshaft 6 of the driving rotary body 2 (crankshaft not shown) is returned in the advance angle side D1 direction, and the opening and closing timing of the valve not shown is changed.

Next, the operation of the self-lock mechanism 11 will be described. The assembly angle between the intermediate shaft 7 (camshaft 6) and the driving rotor 2 (crankshaft not shown) is determined by the relative rotation of the control rotor 3 with respect to the driving rotor 2 in either the advance angle side D1 direction or the retard angle side D2 direction by the rotational operation force applying mechanism 9, as described above. However, since disturbance torque generated by reaction of a valve spring, not shown, is input to the camshaft 6, when the assembly angle is displaced between the camshaft 6 and the driving rotor 2 by the disturbance torque, unexpected disturbance occurs in the valve opening/closing timing. The self-locking mechanism 11 of the present embodiment prevents the assembly angle from deviating by the occurrence of the disturbance torque.

Fig. 7 shows the force acting between the outer peripheral surfaces (14 c, 14D) of the lock plates 14 and the inner peripheral surface of the cylindrical portion 20 of the drive cylinder 5 and the self-locking action when the camshaft 6 (intermediate shaft 7) generates a disturbance torque in either the clockwise direction D1 or the counterclockwise direction D2.

When the camshaft 6 and the intermediate shaft 7 receive disturbance torque in the retard side D2 direction or the advance side D1 direction, the eccentric circular cam 12 receives eccentric rotation torque in the D2 direction or the D1 direction, in which the cam center L1 is eccentrically rotated about the camshaft center axis L0. The cam center axis L1 is an axis eccentric from the cam shaft center axis L0 by an eccentric distance s, and when a straight line connecting L0 and L1 is L2 and a straight line passing through L1 and orthogonal to L2 is L3, the guide plate bush 13 receives a disturbance torque in the D2 direction from the eccentric circular cam 12, a force F1 in the direction from L1 to P1 is received from the eccentric circular cam 12 along the straight line L3 at the intersection P1 of the straight line L3 and the eccentric circular cam 12. When the eccentric circular cam 12 receives disturbance torque in the direction D1, the guide plate bush 13 receives a force F2 in the direction from L1 to P2 from the eccentric circular cam 12 along the line L3 at the intersection point P2 of the line L3 and the eccentric circular cam 12.

Further, the force (F1, F2) is transmitted from the lock plate bush 13 to the lock plate 14 via the flat surfaces (23, 24) in surface contact with each other and the long surfaces (15 c, 15 d) of the holding groove 15 on the straight line L3. Further, forces (F1, F2) are transmitted from the lock plate 14 to the inner peripheral surface 20a of the cylindrical portion of the drive cylinder 5 at intersection points (P3, P4) between the straight line L3 and the outer peripheral surfaces (14 c, 14 d) of the lock plate constituent members (14 a, 14 b).

Between the inner circumferential surface 20a of the cylindrical portion of the drive cylinder 5 and the outer circumferential surfaces (14 c, 14 d) of the lock plate 14, local frictional force that hinders relative rotation between the drive cylinder 5 and the lock plate 14 occurs at the intersection points P3 and P4 due to the forces (F1, F2). The local frictional force is expressed as follows. First, L4 represents straight lines extending in the tangential direction of the outer peripheral surfaces (14 c, 14 d) of the lock plate constituting members through the intersection points P3 and P4, L5 represents a straight line orthogonal to L3, L6 represents a straight line orthogonal to L4, θ 1 represents the inclination of the straight lines L4 and L5 and the inclination of the straight lines L3 and L6 at the intersection point P3, and θ 2 represents the intersection point P4 (hereinafter referred to as "friction angle"), and when the friction coefficient of the friction surface is μ, the force causing the assembly angle misalignment between the driving rotor 2 and the camshaft 6 is represented by forces F1 × sin θ 1 and F2 × sin θ 2 in the tangential direction of the intersection points P3 and P4. The local frictional forces in the opposite direction that inhibit the sliding between the inner circumferential surface 20a of the cylindrical portion and the outer circumferential surfaces (14 c, 14 d) of the lock plate 14 are represented by μ × F1 × cos θ 1 and μ × F2 × cos θ 2, respectively.

If the frictional force is greater than the force causing the assembly angle to be displaced, the drive cylinder 5 and the lock plate 14 are held in a mutually non-rotatable manner. In this case, the lock plate bush 13 and the eccentric circular cam 12 (intermediate shaft 7) are also held in a manner not to be relatively rotatable with respect to the drive cylinder 5. As a result, the drive rotor 2 and the camshaft 6 are locked against relative rotation by the occurrence of the disturbance torque, and the assembly angle does not shift between the camshaft 6 and the control rotor 2 (crankshaft).

If the conditions of F1 × sin θ 1 < μ × F1 × cos θ 1 and F2 × sin θ 2 < μ × F2 × cos θ 2 are satisfied, the local frictional force that interferes with the sliding of the lock plate 14 and the drive cylinder 5 becomes larger than the force that causes the assembly angle deviation, and therefore, a self-locking action occurs between the two. Therefore, the composition satisfies the relation of θ 1 < tan^-1μ、θ2＜tan^-1When the friction angles θ 1 and θ 2 are set as μ, the self-locking function is activated when interference occurs between the driving rotor 2 (not shown crankshaft) and the camshaft 6, and therefore, an assembly angle deviation due to the interference is prevented from occurring.

When the lock plate bushing 13 having the flat surfaces (23, 24) is interposed between the eccentric circular cam 12 and the holding groove 15, the contact stress generated in the holding groove 15 at the time of self-locking is reduced by surface contact with the long surfaces (15 c, 15 d). However, even if the eccentric circular cam 12 is directly held in the holding groove 15 so that the straight line L2 passing through the centers (L0, L1) and the long surfaces (15 c, 15 d) become substantially parallel, the self-locking function is activated, and therefore, the lock plate bush 13 can be omitted.

Next, a 2 nd embodiment of the self-lock mechanism of the phase variable device relating to the engine will be described with reference to fig. 8. The self-lock mechanism 41 of embodiment 2 has the same configuration as the self-lock mechanism 11 of embodiment 1 except that the lock plate bushing 42 and the lock plate 43 have different shapes and include a spring member 44 (urging mechanism of claim 4).

Specifically, the lock plate bush 42 of embodiment 2 is the same in shape as the lock plate bush 13 of embodiment 1 except that it has a ring shape in which no flat surfaces (23, 24) are provided. The lock plate 43 of embodiment 2 is the same as the lock plate 14 of embodiment except that the slit 47 is formed larger than the slit 46 for attaching the spring member 44.

The annular lock plate bush 42 is attached to the eccentric circular cam 12 through a circular hole 42 a. The disk-shaped lock plate bushing 42 has a substantially rectangular holding groove 45 extending in the radial direction. The lock plate bushing 42 is configured by a pair of components (43 a, 43 b) divided by a pair of slits (46, 47) or the like linearly extending from the short surfaces (45 a, 45 b) of the holding groove 45 toward the outer periphery of the lock plate 43. The slit 46 has the same shape as the slit 25 of the lock plate 14 of embodiment 1, but the slit 47 is different from the slit 26 of embodiment 1 in that the width of the slit 46 is larger than that of the slit 47.

Further, a spring member 44 is attached to the slit 47. The spring member 44 has a shape in which returning portions (44 b, 44 c) bent outward are provided at both ends of the arcuate convex portion 44a, and the width of the arcuate convex portion 44a is formed larger than the width of the slit 47. The spring member 44 holds the outer peripheral surfaces (43 c, 43 d) of the constituent members (43 a, 43 b) at the return portions (44 b, 44 c) by fitting the arc-shaped convex portion 44a into the slit 47, and applies an elastic force to the constituent members (43 a, 43 b) so as to expand the slit 47 in the width direction. As a result, in the self-lock mechanism 41, the gap formed between the outer peripheral surfaces (43 c, 43 d) of the lock plate constituting members (43 a, 43 b) and the inner peripheral surface 20a of the cylindrical portion of the drive cylinder 5 due to manufacturing errors and the gap formed between the lock plate bush 42 and the holding groove 45 are reduced, and the rattling of the members at the time of self-locking is reduced, whereby the pressing force of the lock plate 43 against the cylindrical portion 20 at the time of self-locking is increased, and therefore, a reliable self-locking action is generated.

Further, the force (F1, F2) transmitted from the cam center L1 of the eccentric circular cam 12 to the inner circumferential surface 20a of the cylindrical portion of the drive cylinder 5 along the straight line L3 by the disturbance torque is transmitted from the lock plate bush 42 to the lock plate constituting members (43 a, 43 b) by the line contact of the straight line L3 with the intersection points (P5, P6) of the outer periphery of the lock plate bush 42, and acts on the inner circumferential surface 20a of the cylindrical portion of the drive cylinder 5 at the intersection points (P7, P8) of the straight line L3 with the outer circumferential surfaces (43 c, 43 d). In this case, the friction angle corresponding to (θ 1, θ 2) in example 1, which is formed between the line extending in the tangential direction from the intersection point (P7, P8) and the line orthogonal to the straight line L3, is set to the same range as in example 1 (θ 1 < tan)^-1μ、θ2＜tan^-1μ), a self-locking function by a disturbing torque is established between the locking plate 43 and the cylindrical portion 20 of the drive cylinder 5.

The biasing mechanism for expanding the slit 47 in the width direction may be the biasing mechanism shown in fig. 9 (a) and (b), in addition to the spring member 44 as shown in fig. 8. That is, in fig. 9 (a), the outer peripheral end of the slit 47 is provided with cut-out portions (47 a, 47 b) that are cut into thin lines in the direction of the camshaft center axis L0, and the trapezoidal members 48a are disposed in the cut-out portions (47 a, 47 b). The trapezoidal member 48a is a member having a mounting portion 48c of a spring member 48b having a shape corresponding to the spring member 44 on the outer peripheral side, and receives an elastic force in the direction D7 from the mounted spring member 48b toward the center axis L0, and applies a force perpendicular to the surfaces of the notched portions (47 a, 47 b), thereby expanding the slit 47.

In fig. 9 (b), the C-shaped plate spring member 49 is arranged along the outer periphery of the lock plate constituting members (43 a, 43 b), thereby expanding the slit 47 in the width direction and biasing the lock plate constituting members (43 a, 43 b) in the direction of reducing the width of the slit 46. The leaf spring member 49 is disposed so that the opening of the C-shape corresponds to the slit 46 with respect to the lock plate constituting members (43 a, 43 b). The leaf spring member 49 may be configured such that, for example, the left half portion in fig. 9 (b) is fixed to the constituent member 43a, and the constituent member 43b to which the right half portion is attached receives an urging torque in the direction substantially D2 with respect to the constituent member 43a (provision resistance トルク). Outer peripheral surfaces (43 c, 43 d) of the lock plate constituting members (43 a, 43 b) are biased toward the inner peripheral surface 20a of the cylindrical portion of the drive cylinder 5 by a plate spring member 49. As a result, the clearance due to manufacturing errors and the like formed between the inner circumferential surface 20a of the cylindrical portion of the drive cylinder 5 and the outer circumferential surfaces (43 c, 43 d) of the lock plate 43 and between the lock plate bush 50 and the holding groove 45 is reduced by the elastic force of the leaf spring member 49, and thus, a reliable self-locking action occurs.

As indicated by reference numeral 50 in fig. 9 (b), the lock plate bush may be constituted by lock plate bush constituting members (50 a, 50 b) divided by slits (50 c, 50 d) or the like arranged on an extension of the straight line L2. When the lock plate bushing is divided, a gap formed between the inner peripheral surface 50e of the lock plate bushing 50 and the outer periphery of the eccentric circular cam 12 due to a manufacturing error or the like is further reduced, so that the rattling is reduced, and a more reliable self-locking action is generated. When the biasing means such as the spring member 44 shown in fig. 8 and 9 is provided, since the rattling caused by the manufacturing error is reduced by the elastic force, the dimensional accuracy of the eccentric circular cam 12, the lock plate bushes (42, 50), and the lock plate 43 can be relaxed, and the manufacturing can be performed at low cost.

As shown in fig. 10, the lock plate may be formed in a substantially C-shape (reference numeral 51) in which a slit 53 that opens from the holding groove 52 to the outer peripheral surface 51a of the lock plate 51 is provided at only one location, and the inner peripheral surface 20a (the left-right d2 and d3 directions in fig. 10) may be assembled by constantly applying a force, for example, such that the outer diameter of the lock plate 51 in the left-right direction (the direction along the line L3) is slightly larger than the inner diameter of the inner peripheral surface 20a of the cylindrical portion 20. In this case, the same effect can be obtained while omitting the spring members as shown in fig. 8 and 9.

Next, a self-lock mechanism 3 relating to a phase variable device of an engine will be described with reference to fig. 11. The self-lock mechanism 61 of embodiment 3 has a structure common to the self-lock mechanism 41 of embodiment 2 except that the spring member 44 is omitted from the self-lock mechanism 40 of embodiment 2 and the shape of the lock plate bushing 42 is changed to the shape indicated by reference numeral 62.

The lock plate bush 62 has a pair of flat surfaces (62 a, 62 b) on the left and right sides, and a pair of parallel stepped surfaces (63, 64) provided on a pair of stepped portions (62 c, 62 d) protruding from the flat surfaces (62 a, 62 b) to the left and right outside.

The lock plate bush 62 is attached to the eccentric circular cam 12 via a circular hole 62e so that the step surfaces (63, 64) are parallel to a straight line L2 extending from the camshaft center axis L0 in the cam center L1 direction. On the other hand, the step surfaces (63, 64) are formed so as to be arranged symmetrically with respect to the straight line L2 and so as to be eccentric from the cam center L1 by being attached to the eccentric circular cam 12. That is, the stepped surfaces (63, 64) are provided at positions protruding outward from the flat surfaces (62 a, 62 b) in a region in a direction (direction d1 from L0 to L1) further eccentric from the intersection points (C1, C2) of the straight line L3 and the flat surfaces (62 a, 62 b). Further, a straight line L7 connecting the centers of the planes 63 and 64 is substantially parallel to the straight line L3, and is orthogonal to the straight line L2 at an intersection C3 eccentric from the camshaft center axis L0 with respect to the cam center L1. The step surfaces (63, 64) are held by the long surfaces (45 a, 45 b) of the holding groove 45.

When the eccentric circular cam 12 receives the disturbing torque in the direction of D2 or D1, the long surface (45 a, 45 b) of the holding groove 45Forces (F3, F4) in the left-right outward direction along the straight line L7 are applied to stepped surfaces (63, 64) which are in surface contact with each other at a position eccentric from the cam center L1 of the eccentric circular cam 12. Forces (F3, F4) are transmitted from the lock plate 43 to the inner circumferential surface 20a of the cylindrical portion of the drive cylinder 5 at the intersections (P9, P10) between the straight line L7 and the outer circumferential surfaces (43 c, 43 d) of the lock plate constituting members (43 a, 43 b), and act between the lock plate 43 and the cylindrical portion 20 of the drive cylinder 5. In this case, the friction angle corresponding to (θ 1, θ 2) in example 1, which is formed between the line extending in the tangential direction from the intersection point (P9, P10) and the line orthogonal to the straight line L7, is set to the same range as in example 1 (θ 1 < tan)^-1μ、θ2＜tan^-1μ), a self-locking function by a disturbing torque is established between the locking plate 43 and the cylindrical portion 20 of the drive cylinder 5.

Further, a minute gap due to a manufacturing error or the like occurs between the stepped surfaces (63, 64) and the holding surface 45. The stepped surfaces (63, 64) provided in contact with the holding surface 45 at a position eccentric from the cam center axis L1 of the eccentric circular cam 12 as in embodiment 3 cause less sloshing due to the minute gap than when flat surfaces (23, 24) having no step are held in the holding groove 15 as in embodiment 1. That is, if the disturbance torque occurs with a slight clearance, the plane moves around the center axis L0 until it comes into contact with the holding surface, but the distance from the point where the stepped surface (63, 64) at an eccentric position from the cam center L1 contacts the holding groove 45 to the rotation center is longer than the distance from the point where the flat surface (23, 24) without a step contacts the holding groove 15 to the rotation center, so that the amount of deviation of the assembly angle due to the amount of clearance can be reduced even with the same amount of clearance. As a result, even if the spring member 44 is removed from the slit 47, the pressure of the lock plate 43 against the cylindrical portion 20 when the interference occurs can be increased by reducing the rattling, and the self-locking function can be reliably realized.

Description of the symbols

1 phase variable device of engine

2 driving rotating body

3 first control rotating body (control rotating body of claim 1)

6 camshaft

9 rotating operation force applying mechanism

10 Assembly Angle changing mechanism

11 self-locking mechanism

12 eccentric circular cam

13 lock plate bushing

14 lock plate

14a, 14b lock plate constituting member

15 holding groove

16 connecting mechanism

20 cylindrical part

23. 24 pair of planes

25. 26 a pair of slits

27 connecting member

28 control the connecting hole of the rotating body

29 connecting hole of lock plate

44 forcing mechanism (spring component)

50 lock plate bushing

51C-shaped locking plate

53 slit

63. 64 step surface

L0 camshaft center shaft

Cam center of L1 eccentric circular cam

Claims (8)

1. A phase variable device of an engine, comprising: a driving rotator driven by the crank shaft; a control rotating body; a camshaft that supports the driving rotating body coaxially and relatively rotatably; a rotational operation force applying mechanism that applies a relative rotational torque to the control rotating body with respect to the driving rotating body; an assembly angle changing mechanism that changes an assembly angle of the camshaft and the driving rotary body in accordance with relative rotation of the control rotary body with respect to the driving rotary body; and a self-locking mechanism provided on the assembly angle changing mechanism for preventing the deviation of the assembly angle between the driving rotating body and the camshaft caused by the cam torque;

the method is characterized in that:

the self-locking mechanism is provided with an eccentric circular cam, a locking plate and a cylindrical part;

the eccentric circular cam is integrated with the camshaft;

the lock plate has a holding groove for holding the outer periphery of the eccentric circular cam from both sides on the eccentric side of the center axis of the camshaft in the eccentric direction from the center axis of the camshaft toward the cam center of the eccentric circular cam, and a coupling mechanism; a coupling mechanism for transmitting the relative rotational torque from the control rotating body to the eccentric circular cam;

the cylindrical portion is formed integrally with the driving rotating body and inscribes the outer periphery of the lock plate.

2. The phase variable device of the engine according to claim 1, characterized in that: the retaining groove is formed in a radial extension of the locking plate,

having a lock plate bushing mounted on an outer circumference of the eccentric circular cam,

the lock plate bushing has a pair of flat surfaces provided on both left and right sides of the outer periphery thereof in the eccentric direction and held by the holding grooves.

3. The phase variable device of the engine according to claim 2, characterized in that: the lock plate is divided into 2 parts by a pair of slits formed from the holding groove toward the outer peripheral surface of the lock plate.

4. The phase variable device of the engine according to claim 3, characterized in that: an urging mechanism for urging the lock plate divided into 2 parts in a direction to expand the width of the slit is provided on one side of the slit.

5. The phase variable device of the engine according to claim 2, characterized in that: the lock plate has a slit that opens from the holding groove toward an outer peripheral surface of the lock plate, and an outer diameter of the lock plate on both left and right sides across the eccentricity direction is formed slightly larger than an inner diameter length of the inscribed cylindrical portion.

6. The phase variable device of the engine according to claim 4 or 5, characterized in that: the lock plate bushing is divided into 2 parts by a pair of slits.

7. The phase variable device of the engine according to any one of claims 2 to 6, characterized in that: the pair of flat surfaces of the lock plate bushing are a pair of stepped surfaces protruding to the left and right across the eccentric direction, and the pair of stepped surfaces are provided on the eccentric side with respect to the cam center of the eccentric circular cam in the eccentric direction.

8. The phase variable device of the engine according to any one of claims 1 to 7, characterized in that: the coupling mechanism is formed by a pair of coupling holes provided in the control rotating body and the lock plate, respectively, and a coupling member engaged with both of the coupling holes,

a minute gap is formed between the coupling hole on either the control rotary member side or the lock plate side and the coupling member.