JP3049130B2 - Vehicle driving force transmission device - Google Patents

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a device for transmitting driving force to wheels of a vehicle, and can be used for switching driving force transmission in a four-wheel drive vehicle, for example.

[0002]

2. Description of the Related Art A four-wheel drive vehicle mainly intended for off-road traveling needs to obtain a large driving force during low-speed traveling. Therefore, an auxiliary transmission is used and the four wheels are mechanically directly connected. A drive mechanism is employed. However, in such a four-wheel drive vehicle, switching between four-wheel drive and two-wheel drive is performed by connecting / disconnecting a dog clutch utilizing engagement of sliding splines or the like. There is a problem that switching cannot be performed and the optimum running state cannot be arbitrarily selected.

Further, since the conventional driving method is switched by disconnecting the connection between the front wheel propulsion shaft and the rear wheel propulsion shaft in the transfer, even in the two-wheel drive state where only the rear wheels are used, the driving method is switched with the rear wheels. The entire drive path from the front wheel to the front differential and the front wheel propulsion shaft rotates continuously. For this reason, there has been a problem that the loss of the drive system is large, the fuel efficiency is deteriorated, and the noise is increased.

[0004] Therefore, the present invention, by incorporating it into the driving path of the vehicle, allows the driver to freely switch the driving method during traveling, and when the two wheels are driven by the rear wheels, the front wheels are automatically connected. It is an object of the present invention to provide a driving force transmitting device capable of disconnecting the connection between the driving force and the other driving paths.

[0005]

SUMMARY OF THE INVENTION In order to solve the above-mentioned problems, the present invention relates to a clutch for a transfer between a front wheel propulsion shaft and a rear wheel propulsion shaft, and between a joint connected to the front wheel and a front differential. A clutch device on the transfer side is provided between the outer wheel connected to the front wheel propulsion shaft and the input shaft connected to the engine, and holds the engagement element disengaged from the outer wheel and the input shaft by relative rotation with the input shaft. The cage and the rear wheel propulsion shaft are rotatably connected via a clearance in the rotational direction, and both are elastically connected between the rear wheel propulsion shaft and the input shaft at the neutral position of the rotational clearance. A holding member for holding, and a lock member for engaging and disengaging the two to prevent rotation, are provided, and the clutch device on the joint side includes an outer ring connected to the joint and a shaft connected to the front differential. In addition, a retainer that engages the engaging element with the outer ring and the shaft by relative rotation with the shaft is provided, and the retainer and the shaft are co-rotatably connected via a gap in the rotational direction, and between the retainer and the shaft. The differential means for producing a rotation difference is provided.

[0006] The present invention also provides a transfer device according to the above structure, wherein the input shaft and the outer shaft of the clutch device on the transfer side are disposed between the input shaft and the outer shaft.
This adopts a structure in which a tuning device is provided to make the rotations close to each other.

[0007]

In the above structure, when the input shaft rotates in the clutch device on the transfer side, the holding member is elastically deformed by the rear wheel propulsion shaft that is decelerated by the resistance from the rear wheel. The retainer connected to the propulsion shaft rotates relatively, and the engaging element moves to integrate the input shaft and the outer ring. For this reason, the front wheels are driven via the outer wheels,
The rear wheels are driven by the rear wheel propulsion shaft, and are driven by four wheels.

On the other hand, when the input shaft and the rear wheel propulsion shaft are prevented from rotating by the lock member, the engaging member does not move, the outer wheel and the input shaft are held in a separated state, and a two-wheel drive state in which only the rear wheel is performed. Become.

In this two-wheel drive state, the front wheel-side axle connected to the front wheel propulsion shaft is stopped, so that in the joint side clutch device, the outer wheel overruns with respect to the engaging element, and only the front wheel and the joint are engaged. Are separated from the other drive paths and rotate.

In the above-described two-wheel drive state, when the connection between the input shaft and the rear wheel propulsion shaft by the lock member is disconnected and the front wheel propulsion shaft is rotated, in the clutch device on the joint side,
Due to the action of the differential means, the retainer and the shaft rotate relative to each other by the clearance in the rotational direction, the engaging element integrates the outer ring and the shaft, and automatically switches to the four-wheel drive state.

In this switching, if the rotation of the input shaft and the outer ring is tuned by the tuning device, the two components having a difference in rotation can be smoothly coupled, and the drive switching without impact can be performed.

[0012]

Embodiments of the present invention will be described below with reference to the accompanying drawings. FIG. 1 shows an example in which the driving force transmission device of the embodiment is mounted on a driving system of a vehicle. In this figure,
A is a transfer connected to the engine B, C is a front wheel propulsion shaft, D is a rear wheel propulsion shaft, E is a front differential, F is a rear differential, and G is a front wheel axle. A first clutch device H is incorporated in a branch portion of D, and a second clutch device I integrated with a constant velocity joint J is incorporated between the front wheel K and the front differential E. In the drawings, L is a rear wheel, and M is a lever shared with a sub-transmission provided in a driver's seat or the like for switching between two-wheel drive and four-wheel drive.

FIG. 2 shows a front differential E from the front wheel K of FIG.
2 is an enlarged view of a drive path up to the first embodiment. The front differential E is formed by meshing a pinion gear rotatably connected to a differential case with a pair of side gears, similarly to a conventional mechanical differential, and a spline shaft N extending left and right from the front differential E to a constant velocity joint J. And a second clutch device I are connected, and an axle G connected to the constant velocity joint J thereof.
The front wheel K is connected via a constant velocity joint P of a Zeppa type.

FIGS. 3 to 6 show a first clutch device H provided on the transfer side. In FIG. 3, reference numeral 2 denotes an input shaft connected to the engine B. An outer ring 1 is rotatably supported around the input shaft 2 via a pair of bearings 3, 3. The outer ring 1 has a sprocket ring 4 fixed to an outer diameter surface, and is connected to a front wheel propulsion shaft C via a silent chain 5 that engages with the sprocket ring 4 as shown in FIG.

A shaft insertion hole 6 is formed in the front end surface of the input shaft 2 along the axis thereof, and the end of the rear wheel propulsion shaft D is inserted into the shaft insertion hole 6 to be rotatably supported. Have been.
The front end surface of the rear wheel propulsion shaft is formed on a square shaft 7 as shown in FIG. 4, while the closed end of the shaft insertion hole 6 has the square shaft 7
Is formed, and a play X in the rotational direction is provided between the square hole 8 and the square shaft 7.

The input shaft 2 and the rear wheel propulsion shaft D are each provided with an insertion hole 9 penetrating therethrough along the axis, and a torsion bar 10 as a holding member is inserted into the insertion hole 9. . One end of the torsion bar 10 is connected to the rear wheel propulsion shaft D, and the other end is connected to the input shaft 2. Is elastically held at the neutral position of the gap X in the rotational direction.

On the other hand, as shown in FIGS. 3 and 5, a plurality of engaging grooves 11 are formed in the distal end portion of the input shaft 2 in the circumferential direction. A plurality of engagement grooves 12 extending in the axial direction are formed on the outer diameter surface, and a lock member 13 is slidably mounted in the engagement grooves 12. The lock member 13 is provided with two engagement grooves 11, 1
2 and an operating portion 13b connected to the switching lever M. As shown by a solid line in FIG. To prevent the input shaft 2 and the rear wheel propulsion shaft D from rotating.

The inner diameter surface of the outer ring 1 has a cylindrical surface 14.
And an outer diameter surface of the input shaft 2 opposed thereto becomes a cylindrical surface 15 concentric with the cylindrical surface 14.
A large-diameter control holder 16 rotatable between 4 and 15;
A small-diameter fixed retainer 17 fixed to the input shaft 2 is incorporated.

A plurality of pockets 18 and 19 are formed in the control retainer 16 and the fixed retainer 17 so as to face each other in the circumferential direction. Each of the pockets 18 and 19 has a sprag 20 as an engaging element and an elastic member 21. And is incorporated. As shown in FIG. 6, the sprag 20 has an arcuate surface 22 having an outer diameter side and an inner diameter side having a center of curvature on the center line of the sprag, and when inclined by a predetermined angle in both the left and right directions, the arcuate surface 22 becomes cylindrical surface 14. , 15 and the input shaft 2 and the outer ring 1 are integrated. The elastic member 21 is attached to the control retainer 16 and presses the sprags 20 from both sides to press the two cylindrical surfaces 14,
15 is held at a neutral position not engaged.

The control retainer 16 is integrally connected to a pin 23 extending in the radial direction from the rear wheel propulsion shaft D. A pin insertion hole 24 through which the pin 23 is inserted is formed on the peripheral wall of the input shaft 2. Is formed. A clearance is provided between the pin insertion hole 24 and the pin 23 in the rotation direction.
Is held at the neutral position of the gap in the rotation direction by the spring force of the torsion bar 10.

7 to 9 show a second clutch device I provided on the front wheel side. As shown in FIG. 7, the second clutch device I is formed in such a manner that the double offset type constant velocity joint J and the outer ring are shared by the same outer cylinder member 31 and are integrally connected to the joint.

That is, in the constant velocity joint J, one end of the outer cylindrical member 31 is used as an outer ring 32, and the outer ring 32
Inner ring 33 connected to the end of axle G
And the cage 34 are fitted. Ball track grooves 35 and 36 extending straight in the axial direction are formed on the inner diameter surface of the outer race 32 and the outer diameter surface of the inner race 33, and the balls 37 held by the cage 34 fit into the ball track grooves 35 and 36. I agree.

The center of the outer spherical surface and the center of the inner spherical surface of the cage 34 are offset by the same distance to the left and right with respect to the angular center of the joint, and the angular center of the joint is aligned with the center line of the ball pocket of the cage 34. It is set to be at the intersection with the wheel set or the inner wheel set.

In the above constant velocity joint J, the cage 34
Secures the ball 37 on the bisecting surface of the inner and outer axles at all angles of rotation of the joint, transmits the rotation applied to the outer ring 32 to the axle G at a constant speed, and also displaces the inner and outer rings in the joint in the axial direction. Enable.

On the other hand, the second clutch device I is
The other end of 1 is an outer ring 38, and an input shaft 41 is rotatably inserted into an inner hole of the outer ring 38 via bearings 39 and 40.

A spline shaft N extending from the front differential E is fitted into the end of the input shaft 41, and the forward and reverse rotation of the front differential E is transmitted to the input shaft 41 without delay.

The outer diameter surface of the input shaft 41 and the inner diameter surface of the outer ring 38 opposed thereto have cylindrical engagement surfaces 4 respectively.
2 and 43 are formed, and between both engagement surfaces 42 and 43,
A rotatable control holder 44 and a fixed holder 45 pinned to the input shaft 41 are provided.

As shown in FIG. 8, the control cage 44 and the fixed cage 45 are formed with a plurality of pockets 46, 47 facing each other in the circumferential direction.
When they are inclined at a predetermined angle in both the left and right directions, the two engagement surfaces 42 and 43
A sprag 48 that engages with the input shaft 41 and the outer ring 38 and an elastic member 49 that holds each sprag at a neutral position that does not engage with the engagement surfaces 15 and 16 are incorporated.

On the other hand, an operation shaft 50 is rotatably supported inside the input shaft 41 via a bearing, and a pin 51 connected to the center of the operation shaft 50 has a pin hole 52 formed in the input shaft 41. Are connected to the control holder 44.

A pin 53 connected to the rear end of the operating shaft 50 is inserted into a pin hole 54 of the input shaft 41 and connected to a differential means 55. The differential means 55 includes a rolling bearing 56 and a support arm 57 for supporting the bearing 56 on a fixed member of the vehicle body. The rolling bearing 56 is provided with a preload equal to or higher than a predetermined pressure so that a radial gap is zero or less. And is set to have a larger rotational resistance than the bearings 39 and 40 that support the input shaft during rolling when the vehicle is rolling.

In the above-described structure, a force for suppressing the rotation is applied to the operating shaft 50 and the control holder 44 due to the rotational resistance of the rolling bearing 56. At the same time, and is held so as not to be easily rotated by an impact force or an inertial force.

The pin 51 at the center of the operating shaft 50 is
As shown in FIG. 9, it is integrally fixed to the control retainer 44, but is loosely fitted in the pin hole 52 of the input shaft 41 with a clearance Y in the rotation direction. Between the input hole and the pin hole 54, a circumferential gap larger than the rotational gap Y is provided.

The clearance Y in the rotational direction is determined by the control holder 44.
Is determined with respect to the input shaft 41, and its magnitude is
The distance between the sprag 48 and the neutral position between the engagement surfaces 42 and 43 until the sprag 48 contacts the two engagement surfaces via the elastic member 49 is set to be larger than the distance.

The driving force transmission device of this embodiment has the above-described structure. Next, the operation of the transmission device will be described for various running states.

(A) As shown by a dashed line in FIG.
In the clutch device H, when rotation is applied from the engine B to the input shaft 2 in a state where the lock member 13 is separated from the input shaft 2, rotation resistance is applied to the rear wheel propulsion shaft D from the rear wheel that is in contact with the road surface. Therefore, the torsion bar 10 is deformed, the input shaft 2 and the rear wheel propulsion shaft D rotate relatively, and the control retainer 16 and the fixed retainer 17 move relatively.

For this reason, the sprags 20 have the two cylindrical surfaces 14,
The rotation of the input shaft 2 is transmitted to the front wheel propulsion shaft C via the outer wheel 1. When the elasticity of the deformed torsion bar 10 exceeds the rotational resistance applied to the rear wheel propulsion shaft D from the rear wheel, the rear wheel propulsion shaft D rotates together with the input shaft 2 to drive the rear wheel.

When the axle G is rotated by the front wheel propulsion shaft C, in the second clutch device I on the front wheel side, the control retainer 44 decelerated by the action of the differential bearing 55 is moved by the clearance Y in the rotational direction. The rotation is delayed from the input shaft 41, and the rotation relative to the fixed retainer 45 is performed. The two retainers 44,
Due to the relative rotation of 45, the sprags 48 are tilted in the opposite direction to the rotation direction of the input shaft, and come into contact with the engagement surfaces 42 and 43 to be engaged.

In the above state, when the input shaft 41 continues to rotate by the operation of the front differential E, and a rotation difference is generated between the input shaft 41 and the outer ring 38, the sprag 48 is immediately moved to the engagement surface 42,
The outer ring 38 and the input shaft 41 are integrated with each other. For this reason, the driving force of the axle G is transmitted to the front wheels via the wheel hub 34, and a four-wheel drive state is established.

(B) In the four-wheel drive running state, when the front wheel rotates faster than the rear wheel due to turning at a tight corner or the like, the rotation of the outer wheel 38 in the second clutch device I causes the input shaft 4 to rotate.
More than one revolution. In this state, the outer race 38 overruns the sprags 48 and the sprags 48 do not engage with the engagement surfaces 42 and 43, so that the input shaft 41 and the outer race 3
8 rotates in a disengaged state and is in a two-wheel drive state with only the rear wheels, so that no braking phenomenon occurs at tight corners.

(C) In the two-wheel drive state using the rear wheels,
When the rear wheel slips or one of the rear wheels derails, the rotation of the input shaft 2 connected to the engine B catches up with the rotation of the outer wheel 1 that is decelerated as the vehicle speed decreases in the first clutch device H. Then, the sprags 20 are engaged with the cylindrical surfaces 14 and 15 so that the driving force is transmitted to the front wheels, thereby shifting to four-wheel drive.

When one of the front wheels comes off in the four-wheel drive mode, an effective driving force is not transmitted to the front wheels due to the differential function of the front differential E. , The traveling state of the vehicle is maintained.

(D) On the other hand, in the first clutch device H, the lock member 13 is moved by the switching lever M,
As shown by the solid line in FIG. 3, when the lock member 13 is fitted into the engagement grooves 11 and 12 of the input shaft 2 and the rear wheel propulsion shaft D, the input shaft 2 and the rear wheel propulsion shaft D rotate integrally. Therefore, engagement of the sprag 20 does not occur. Therefore, the driving force is transmitted only to the rear wheels, and the two-wheel drive state is maintained.

In the two-wheel drive state, the transfer A
, The front wheel E and the front wheel E do not rotate, and the front differential E is stopped. Therefore, in the second clutch device I, the outer wheel 38 overruns with respect to the sprag 48, and the constant velocity joint J and the front differential E is cut off. Therefore, the front wheel K rotates around the rear wheel L, and the drive path of the front wheels from the second clutch device I to the front differential E and the front wheel propulsion shaft C is stopped.

(E) From the two-wheel drive state, the first
Disengage the lock member 13 in the clutch device H,
When the fixed state of the input shaft 2 and the rear wheel propulsion shaft D is released, the torsion bar 10 is used to perform the untwisting function, and the sprag 2
0 engages the input shaft 2 with the outer wheel 1 and rotates the front wheel propulsion shaft C.

In this case, when the front differential E rotates,
In the second clutch device I, the cage 44 and the input shaft 41 rotate relative to each other by the action of the differential bearing 55, and the sprags 48 are engaged.

At the time of the above switching, the front wheel K is connected to the rear wheel L
Therefore, even if the rotating input shaft 41 of the second clutch device I is engaged with the outer wheel 38, there is no torque load, and smooth switching can be performed during traveling.

Further, at the time of the above-mentioned switching, in the first clutch device H, the rotating sprags 20 are engaged with the outer ring 1 in the stopped state, but the sprags 20 do not have a fixed engagement position such as a spline. , Can be engaged at any position, so that a smooth connection can be made.

In the above description, the operation in one direction of the vehicle has been described. However, when the rotation direction applied to the first clutch device H from the transmission is reversed, the inclination of the sprags 20, 48 in the first and second clutch devices is reduced. Since the engagement is reversed, the drive can be switched in exactly the same way in both the forward and backward directions.

Although the operation of the lock member 13 is performed by operating the switching lever M, the lock member may be operated by another mechanical mechanism or an electrical mechanism.

FIG. 10 shows an example in which a tuning device 61 is provided between the outer ring 1 and the input shaft 2 in the above-mentioned first clutch device H so as to make the rotational speeds of both of them close to each other.

The tuning device 61 comprises an operating member 63 movably provided in an engagement groove 62 on the outer diameter surface of the input shaft 2 and a friction member 65 provided on a pressing surface 64 of the operating member 63.
By bringing the friction material 65 into contact with the flange end surface 66 of the outer ring 1, the rotation of the input shaft 2 and the rotation of the outer ring 1 are synchronized by sliding friction. Such synchronization of rotation is performed by the lock member 13.
Is performed before the coupling between the input shaft 2 and the rear wheel propulsion shaft D is released, the input shaft 2 that is rotating at a high speed can be smoothly coupled to the stopped outer wheel 1 without any impact.

FIGS. 11 and 12 show another example of the first clutch device. In this clutch device H ′, a plurality of cam surfaces 74 that form a wedge-shaped space between the input shaft 72 and the cylindrical surface 73 of the outer race 71 are formed on the outer diameter surface of the input shaft 72.
And a pocket 76 of a retainer 75 provided between the
A roller 77 that engages with the cylindrical surface 73 and the cam surface 74;
An elastic member 78 for holding the roller 77 at the neutral position is incorporated.

Further, the torsion bar for connecting the input shaft 72 and the rear wheel propulsion shaft D is eliminated, and instead, a pin 80 for connecting the rear wheel propulsion shaft and the holder 75 and a pin insertion hole provided in the input shaft 72 are provided. 81, an elastic ring 7 as a holding member.
9 is held, and the elastic force of the elastic ring 79 holds the square axis 82 of the rear wheel propulsion shaft D at the neutral position in the play X in the rotational direction with respect to the square hole 83.

Other components are the same as those in the above-described embodiment, and the same components are denoted by the same reference numerals and description thereof will be omitted.

In the above structure, when the input shaft 72 rotates, the elastic ring 79 is deformed, and the input shaft 72 and the rear wheel propulsion shaft D rotate relative to each other, and the retainer 75 moves the roller 77. When there is no rotation difference between the input shaft 72 and the rear wheel propulsion shaft D, the elasticity of the elastic ring 79 returns the rear wheel propulsion shaft D to the neutral position, and disengages the roller 77.

In each of the embodiments described above, a pair of left and right sprags engaged in one direction of rotation may be incorporated between the engagement surfaces for use as the clutch engagement element of the clutch.

Further, the differential means for providing a rotational difference between the cage and the axle is not limited to the one using the above-mentioned rolling bearing, but is decelerated by a differential speed mechanism using a gear or by sliding contact with a friction member. It is also possible to use a brake mechanism or the like that causes the brake mechanism.

Further, the second clutch device I and the constant velocity joint J may not be integrally formed, but may be arranged independently by separating the outer races.

[0059]

As described above, the driving force transmission device of the present invention
A clutch device that switches the engagement according to the speed difference between the input and output is provided at the joint of the transfer branch and the front wheel, so that the drive switching between the four wheels and the two wheels can be automatically performed. Full-auto four-wheel drive with excellent fuel efficiency and noise performance, because the front wheel drive path can be stopped during rear wheel two-wheel drive and the front wheel can be automatically coupled to the drive path during four-wheel drive. Can be realized.

[Brief description of the drawings]

FIG. 1 is a diagram illustrating an example of mounting a vehicle on a drive path according to an embodiment;

FIG. 2 is an enlarged view showing a drive path of a front wheel according to the first embodiment;

FIG. 3 is a longitudinal sectional front view showing a first clutch device of the embodiment.

FIG. 4 is a sectional view taken along the line IV-IV in FIG. 3;

FIG. 5 is a sectional view taken along the line VV in FIG. 3;

FIG. 6 is a sectional view showing an operation state of the sprag according to the first embodiment;

FIG. 7 is a longitudinal sectional front view showing a second clutch device of the embodiment.

FIG. 8 is a sectional view taken along the line VIII-VIII in FIG. 7;

FIG. 9 is a sectional view taken along the line IX-IX of FIG. 7;

FIG. 10 is a longitudinal sectional front view showing another embodiment.

FIG. 11 is a longitudinal sectional front view showing another example of the first clutch device.

FIG. 12 is a sectional view taken along the line XII-XII of FIG. 11;

[Explanation of symbols]

 Reference Signs List A Transfer C Front wheel propulsion shaft D Rear wheel propulsion shaft E Front differential G, G 'Axle H 1st clutch device I 2nd clutch device J Constant velocity joint 1, 38, 71 Outer wheel 2, 41, 72 Input shaft 10 Torsion bar 16 Control retainer 17 Fixed retainer 20 Sprag 44 Control retainer 45 Fixed retainer 48 Sprag 55 Differential bearing 61 Tuning device 75 Retainer 77 Roller 79 Elastic ring

Continuation of the front page (56) References JP-A-4-328026 (JP, A) JP-A-1-117426 (JP, A) JP-A-2-271116 (JP, A) Jpn. , U) (58) Fields surveyed (Int. Cl. ⁷ , DB name) B60K 17/28-17/36 B60K 23/00-23/08

Claims (2)

(57) [Claims] A clutch device is provided between a front differential and a joint between a front wheel propulsion shaft and a rear wheel propulsion shaft of a transfer, and a joint connected to a front wheel, and a transfer side clutch device is connected to the front wheel propulsion shaft. A retainer for engaging and disengaging the engaging element between the outer ring and the input shaft by relative rotation with respect to the input shaft is incorporated between the outer ring to be engaged and the input shaft connected to the engine, and a clearance is provided between the retainer and the rear wheel propulsion shaft in the rotational direction. And a holding member that elastically holds the rear wheel propulsion shaft and the input shaft between the rear wheel propulsion shaft and the input shaft at the neutral position of the clearance in the rotational direction. The clutch device on the joint side is configured such that the engaging element is engaged with the outer ring and the shaft by relative rotation with the shaft between the outer ring connected to the joint and the shaft connected to the front differential. A retainer is provided, and the retainer and the shaft are rotatably connected to each other through a clearance in the rotational direction.
A driving force transmission device for a vehicle comprising a differential means for generating a rotational difference between a retainer and a shaft. 2. The driving force transmission device for a vehicle according to claim 1, further comprising a rotation tuning device for bringing the rotations of both clutches closer to each other between the input shaft and the outer shaft of the clutch device on the transfer side.