JP2001097063A - Atv drive accelerator - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide a lightweight and compact ATV drive accelerator having good actuating performance. SOLUTION: A double off-set type constant velocity universal joint J2 is used in an in-board side of a drive accelerator, and an undercut free type constant velocity universal joint J1 is used in an out-board side. The cage off-set amount of the undercut free type constant velocity universal joint J1 is made to be zero, and the track off-set angle ϕ T is set to be from 5 deg. to 7 deg..

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to an ATV (All Terr
ain Vehicle: a drive axle for a saddle-ride type vehicle for traveling on uneven terrain, also called a four-wheel buggy.

[0002]

2. Description of the Related Art An ATV is a four-wheel or three-wheel saddle-ride type vehicle for traveling on uneven terrain, and is equipped with balloon tires so that it can freely travel on rough terrain or sandy beaches. In the power transmission device of this ATV, for example, as conceptually shown in FIG. 6, power of the engine 21 is output from front and rear output shafts via an internal transmission mechanism, and power transmission means such as a chain or a propeller shaft is used. 22, 2
Front and rear differentials 2 through 3
4 and 25, respectively. Then, the engine power input to the differentials 24, 25 is reduced by the mechanism of the differentials 24, 25, and further converted into rotational power in the right-angle direction, and transmitted to the wheels 28, 29 via the left and right drive axles 26, 27. Is done. In the example shown in FIG.
A constant velocity universal joint is used for a connecting portion A between the motor 6 and the differential 24 and a connecting portion B for connecting to the wheel 28. In some cases, a constant velocity universal joint may be used for the connection part C between the rear drive axle 27 and the differential 25 and the connection part D for the wheel 29. When propeller shafts are used as the power transmission means 22 and 23, connection portions E and F between the propeller shaft and the output shaft of the engine (transmission mechanism) 21, and connection portions G and H between the differentials 24 and 25 are respectively provided. In some cases, a constant velocity universal joint is used.

FIG. 7 shows a drive axle 2 on the front side.
6 is shown. The drive axle 26 is connected to a slide-type constant velocity universal joint (2) so that the drive axle 26 can be angularly and axially displaced in accordance with the movement of the wheel 28 at the time of cornering or running on uneven terrain. A constant velocity universal joint (permitting angular displacement between two axes) 30 and a fixed constant velocity universal joint (constant velocity universal joint permitting angular displacement between two axes) 31 are used as a pair. In the example shown in the figure, one end (inboard side) of a drive axle 26 is connected to a differential 24 via a sliding constant velocity universal joint (double offset type constant velocity universal joint, hereinafter referred to as “DOJ”) 30. Then, the other end (outboard side) of the drive axle 26 is connected via a fixed type constant velocity universal joint (Zepper type constant velocity universal joint: ball fixed joint, hereinafter referred to as “BJ”) 31. It is connected to the wheel 28 (connection part B).

[0004] Conventionally, as the DOJ or BJ, a passenger car specification is often diverted and used.

[0005]

Since the weight of the body of an ATV vehicle is strict, the drive axle is required to be further reduced in weight and size. Also,
ATVs are small and have a narrow vehicle width, and the operating angle of the constant velocity universal joint used on the drive shaft is almost twice as large as that for passenger cars. For passenger car specifications, the operating stability of the constant velocity universal joint depends on the operating conditions. May be harmed. Furthermore, in the above-mentioned constant velocity universal joint for ATV, the durability (lifetime) is about 1/100 that of a passenger car in consideration of the market performance and the warranty period.
Since 2 is sufficient, there is a feeling of excessive quality in passenger car specifications. The same can be said for the number of rotations to be used, which is about １ ／ of the passenger car specification, in consideration of the vehicle speed. On the other hand, in terms of strength, such as torsional strength, it is required to have a strength similar to that of a passenger car.

Accordingly, an object of the present invention is to provide a drive axle for an ATV which is lightweight, compact and has good operability in consideration of the above-mentioned circumstances unique to the ATV.

[0007]

According to the present invention, there is provided a saddle-ride type vehicle for traveling on uneven terrain, the driving force of which is provided via a constant velocity universal joint on an inboard side and an outboard side. A double offset type constant velocity universal joint (DOJ) was used on the inboard side, and an undercut free type constant velocity universal joint (hereinafter, referred to as “UJ”) was used on the outboard side.

The solid line in FIG. 4 shows a state in which the BJ used on the outboard side of the conventional drive axle has a maximum operating angle (for example, 46.5 °). In this state, the ball 4 is located at the end of the track groove 2b of the outer ring 2 on the outer ring opening side. At this time, the ball 4 is in angular contact with the track groove 2b with a contact angle.
Is represented by In this case, if the distance _LBJ between the contact point ● and the end of the track groove 2b on the outer ring opening side can be increased, the allowable maximum operating angle can be increased.

On the other hand, in the UJ, as shown by a broken line in FIG. 1, the outer ring opening side of the track groove 2b of the outer ring 2 (and the inner side of the inner ring track groove) is formed straight. This U
In J, when the axial position of the ball 4 is the same as that of the BJ ball, the contact point の between the ball 4 and the track groove 2b retreats to the far side of the outer ring 2 from the contact point の of the BJ. Therefore, the distance L _UJ from the contact point ○ to the opening end of the track groove 2b is also larger than BJ (L _UJ > L _BJ ).
This is because UJ is B even if the ball diameter and groove depth are the same.
This means that the allowable maximum operating angle becomes larger than J.
Therefore, as described above, a UJ having a large allowable maximum operating angle is used as a constant velocity universal joint on the outboard side instead of the conventional BJ.
Is used, even when the operating angle of use is large as in the case of the ATV, it is possible to secure sufficient follow-up to the angular displacement of the drive shaft.

In the conventional UJ, as shown by a solid line in FIG. 5, each spherical center O of the outer spherical surface 5a and the inner spherical surface 5b of the retainer 5 is formed.
_CO and O _CI are offset from the joint center O by an equal distance on opposite sides in the axial direction. This is called cage offset, and the conventional cage offset amount f is 0.3 to
0.7 mm, and the cage offset angle φ _C is 1
° or more. Due to this cage offset, the thickness of the cage 5 on the opening side (the right side in FIG. 5) is increased.
Can be prevented from falling off.

[0011] On the other hand, in the present invention, the cage
The offset was set to zero. Thus, the cage offset
If it is set to 0, the thickness of the cage 5 is
Is uniform, so that the workability is improved and the cage 5
It is possible to improve the assemblability by eliminating the directional property.
Wear. In this case, the thickness of the cage 5 on the outer ring opening side is reduced.
Of the ball 4 at the maximum operating angle
However, as described above, the ATV
Low durability (for example, 70-80% for passenger cars)
Therefore, the depth of the track grooves 2b, 3b of the outer ring 2 and the inner ring 3
Can be set shallower than before, and the cage
The thickness of ball 4 is increased by increasing the thickness of
Dropping can be reliably prevented.

[0012] In the conventional BJ, the track groove center of the inner and outer rings
O_TI, O_TOAnd the joint center are offset by the same distance from each other.
(Track offset), $ O_TOQO (or ∠
O_TIQO) Track offset angle φ_TIs less than 8 °
(Track groove center O_TI, O_TOand
Track offset angle φ_TSee FIG. 2 for details). Tiger
Work offset angle φ_TIs large, the bending torque
Operability is improved because
Work offset angle φ_TIs too large, the track groove depth
The shallowness increases the axial width of the joint, reducing weight
Good for ATVs, which are demanded to be compact and compact.
Not good. Therefore, in the present invention, the track offset
Angle φ_TWas set to 7 ° or less. On the other hand, track offset
Angle φ_TIs too small, it is acceptable for ATV.
The durability and strength may be reduced.
Offset angle φ_TIs 5 ° or more. From the above, UJ
Track offset angle φ_TIs set at 5-7 °
Is good.

[0013] As described above, the constant speed universal joint on the inboard side
DOJ is used for the hand as before. Traditionally,
DOJ cage offset angle φ_CIs 9 ° or more
However, in the present invention, a smaller φ_C= Set from 6 ° to 8 °
The company has decided to reduce the weight and size. like this
To cage offset angle φ_CEven if is made smaller,
By setting the durability to lower than before, the inner and outer rings
Shallower track groove depth and thicker cage.
The ball from the cage pocket
Can be prevented.

[0014]

DESCRIPTION OF THE PREFERRED EMBODIMENTS An embodiment of the present invention will be described below with reference to FIGS.

[0015] Drive axle for ATV according to the present invention
Is the outboard side and the inboard side, as shown in Figure 1.
Constant velocity universal joint J₁, J_TwoAnd both joints J₁, J_TwoTo
And an intermediate shaft 1 to be connected. Outboard side etc.
Speed universal joint J₁Is connected to a wheel (not shown)
Constant velocity universal joint J on the board side_TwoIs a differential not shown
Combined with Shal.

[0016] Outboard side constant velocity universal joint J₁Is
Consists of an undercut free type constant velocity universal joint (UJ)
You. As shown in FIG. 2, the UJ is provided on the spherical inner peripheral surface 2a.
A plurality (usually six) of curved track grooves 2b are inserted in the axial direction.
The outer member 2 (outer ring) formed on the outer peripheral surface 3a
A plurality of (usually six) curved track grooves 3b in the axial direction
The inner member 3 (inner ring) formed in the direction
The lock groove 2b and the track groove 3b of the inner member 3 cooperate.
A plurality (communications) respectively arranged on the formed ball track
Normally 6) torque transmitting balls 4 and torque transmitting balls 4
Cage 5 having a plurality of pockets 5c for holding
). Serration on the inner circumference of the inner member 3
The intermediate shaft 1 is connected via a component such as
The wheel is coupled to the stem 2c.

The center O _TO of the track groove 2b of the outer member 2 and the center O _TI of the track groove 3b of the inner member 3 are axially opposite from the center O of the joint by an equal distance (the center O _TO is the center of the joint). The opening side, _OTI, is offset to the far side of the joint (track offset). Therefore, the ball track has a wide opening side and a shape (wedge shape) gradually reduced toward the back. Track groove 2 of outer member 2
Some regions U _I of b of a part of U _O and track grooves 3b of the inner member 3, the groove bottom as viewed in each vertical section is a straight section 2b1,3b1 straight is formed. The straight portion 2b1 of the outer member 2 is formed at one end of the track groove 2b (the end on the opening side of the joint), and the straight portion 3b1 of the inner member 3 is formed at the other end of the track groove 3b (the inner side of the joint). End). Due to the presence of the straight portions 2b1, 3b1, the allowable maximum operating angle of the UJ can be made larger (for example, 50 °) than that of the conventional passenger car BJ (46.5 °).

[0018] Track groove center O of outer member 2_TO(Or
Track groove center O of inner member 3_TI), Ball center Q (joint)
The intersection of the hand plane P and the PCD) and the joint center O
Track offset angle φ_T(∠O_TOQO or $ O
_TIQO) is set to 5 ° or more and 7 ° or less. This tiger
Work offset angle φ_TIs a conventional BJ truck for passenger cars
Smaller than offset angle (more than 8 °) and lighter
-Compactness and durability (for example, 70% of conventional)
The conflicting objectives of
Mobility is also secured.

[0019] Spherical center O of outer spherical surface 5a of cage 5_CO(Outside
The same as the center of the spherical surface of the inner peripheral surface 2a of the side member 2);
Center O of the inner spherical surface 5b_CI(Sphere on the outer peripheral surface of the inner member 3
Is the same as the center of the plane)
Offset in the opposite direction by the same distance in the axial direction (Fig.
5), the cage offset f is set to 0 in the present invention.
Set. That is, the outer spherical surface 5a and the inner spherical surface of the cage 5
5b spherical center O_CO, O_CITo the joint center O.
As a result, the thickness of the cage 5 becomes uniform, so that the workability is improved.
The combination due to the improvement and the loss of direction of the cage 5
Standing can be improved. In this case,
The maximum operating angle was taken because the outer ring opening side was thinner.
There is a concern that the ball 4 may fall out of the cage pocket 5c
However, for ATVs, the durability of constant velocity universal joints is set low.
(For example, 70% for passenger cars)
Track groove 2 can be set shallower than before.
And the thickness of the cage 5 is increased by that amount to reduce the thickness reduction.
It is possible to recover and prevent the ball 4 from falling off.
You.

[0020] Constant velocity universal joint J on the inboard side_TwoThe dub
It is composed of an offset type constant velocity universal joint (DOJ).
DOJ is formed on the cylindrical inner peripheral surface 12a as shown in FIG.
Plural (for example, six) linear track grooves 12b are
Outer member 12 (outer ring) formed in the direction, and spherical outer peripheral surface
13a, a plurality of (for example, six) linear track grooves 13 are formed.
inner member 13 (inner ring) in which b is formed in the axial direction;
Track groove 12b of material 12 and track groove of inner member 13
13b arranged in a ball track formed in cooperation with
A plurality of (for example, six) torque transmitting balls 14;
Composed of a cage 15 (cage) for holding the transmission ball 14
Is done. The stem 12c of the outer member 12 is
And the intermediate shaft is attached to the inner periphery of the inner member 13.
1 are connected through serrations or the like.

The retainer 15 is provided on the inner peripheral surface 12 of the outer member 12.
a, an inner spherical surface 15b guided in contact with the outer peripheral surface 13a of the inner member 13 and a plurality (for example, six) of pockets 15c accommodating the torque transmitting balls 14. is there. The spherical center O of the outer spherical surface 15a
_CO and the spherical center O _CI of the inner spherical surface 15b are respectively offset to the opposite side by the same distance in the axial direction with respect to the joint center O.

When the joint transmits rotational torque while maintaining an operating angle, the retainer 15 rotates to the position of the torque transmitting ball 15 moving on the ball track in accordance with the inclination of the inner member 13, and the torque transmitting ball 15 is rotated. 14 is held in the angle bisector of the operating angle. Thereby, the constant velocity of the joint is ensured. Further, when the outer member 12 and the inner member 13 move relative to each other in the axial direction, a slip occurs between the outer spherical surface 15a of the retainer 15 and the inner peripheral surface 12a of the outer member 12, and a smooth axial movement (plunging) occurs. ).

[0023] The maximum allowable DOJ placed on the inboard side
The large operating angle is determined by the constant velocity universal joint (UJ) on the outboard side.
It is set smaller than that, for example, 30.5 °.

[0024] In the above DOJ, the outer spherical surface 15
The spherical center O of a_CO, Ball center Q and joint center O
The formed cage offset angle φ_C(∠O_COQO or
∠O _CIQO) is set to 6 ° or more and 8 ° or less. this
Cage offset angle φ_CIs the conventional passenger car specification DOJ
Was 9 ° or more.
It is set smaller than before to reduce
You. Thus, the cage offset angle φ_CMake smaller
Also set the durability at about 70% of the specification for passenger cars.
By doing so, the track groove depth of the inner and outer rings can be reduced,
Thereby, the thickness of the cage 5 can be increased.
And the cage pocket 5c when the maximum allowable operating angle is taken
These balls 14 can be reliably prevented from jumping out.
You.

[0025] The drive axle described above is an ATV
Can be used not only on the front side but also on the rear side
You.

[0026]

According to the present invention, the undercut free type is used for the constant velocity universal joint on the outboard side, so that the allowable maximum operating angle can be increased. Therefore, even in an ATV in which the operating angle becomes large due to cornering travel, rough terrain travel, or the like, it is possible to allow a margin for the angular displacement of the drive axle that follows the movement of the wheel.

[0027] Undercut free type constant velocity universal joint
By setting the page offset to 0, the thickness of the cage
Uniformity and improve workability and assemblability of the cage.
Can be. In this case, the ball at the maximum operating angle
Of the ATV for the ATV.
Then, the durability of the constant velocity universal joint is set lower than that for passenger cars.
Since the track groove can be made shallower, it can be held as much
The thickness of the bowl can be increased, and the ball falls off
Can be reliably prevented.

[0028] Undercut free type constant velocity universal joint
Rack offset angle φ_TSet to 5 ° or more and 7 ° or less
If it is lightweight, compact, and durable (about 70%
At the same time)
it can.

[0029] Inboard double offset type constant velocity self
Cage offset angle φ_CIs φ_C= 6 ° to 8 °
By setting, the constant velocity universal joint is reduced in weight and size
can do. Even in this case, the durability as described above
By setting the lower
The groove depth can be reduced and the cage thickness can be increased.
Prevents the ball from jumping out of the cage pocket
can do.

[Brief description of the drawings]

FIG. 1 is a cross-sectional view of an ATV drive axle according to the present invention.

FIG. 2 is a sectional view of a UJ used on the outboard side of the drive axle.

FIG. 3 is a sectional view of a DOJ used on the inboard side of the drive axle.

FIG. 4 is an enlarged sectional view of a main part of BJ and UJ.

FIG. 5 is an enlarged sectional view of a main part of the UJ.

FIG. 6 is a conceptual diagram of an ATV power transmission device.

FIG. 7 is a cross-sectional view of a conventional ATV and a live axle.

[Explanation of symbols]

J ₁ outboard side constant velocity universal joint (UJ) J ₂ inboard side constant velocity universal joint (DOJ) f Cage offset amount φ _C cage offset angle φ _T track offset angle

Continued on the front page (72) Inventor Hideki Kondo 1578 Higashikaizuka, Iwata-shi, Shizuoka F-term (reference) in NTN Corporation 3D043 AA06 AB05 DA00 3J033 AA01 BA02 BA09 BA20

Claims (4)

[Claims] 1. A drive axle mounted on a saddle-ride type vehicle for traveling on uneven terrain and transmitting a driving force to a wheel via a constant velocity universal joint on an inboard side and an outboard side. A drive axle for an ATV, wherein a type constant velocity universal joint is used and an undercut free type constant velocity universal joint is used on an outboard side. 2. The AT according to claim 1, wherein the cage offset amount of the undercut free type constant velocity universal joint is set to zero.
Drive axle for V. 3. The undercut free type constant velocity universal joint according to claim 2, wherein a track offset angle is 5 ° to 7 °.
A drive axle for an ATV as described. 4. The double offset type constant velocity universal joint according to claim 1, wherein the cage offset angle is 6 ° to 8 °.
The drive axle for ATV according to any one of the above.