JP3137387B2 - 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.

On the other hand, a hub clutch capable of transmitting and blocking a driving force between a wheel hub of a front wheel and an axle and separating the rotation of the front wheel from the axle has been disclosed in Japanese Utility Model Publication No. 2-34785. And so on. However, this conventional hub clutch has a structure in which the wheel hub and the axle are directly connected by a slide gear or the like, so it is necessary to manually switch the connection and disconnection between the front wheel and the axle, and the automatic switching operation during running cannot be performed. There is.

[0005] Therefore, the present invention, by incorporating the vehicle into the drive path, 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 and the front wheels are automatically connected. It is an object of the present invention to provide a driving force transmission device capable of disconnecting a connection with a driving path other than the above.

[0006]

SUMMARY OF THE INVENTION In order to solve the above-mentioned problems, the present invention provides a clutch device at a branch portion between a front wheel propulsion shaft and a rear wheel propulsion shaft of a transfer and at a connection portion between a front wheel and an axle. In the installed vehicle driving force transmission device
Te, transfer side of the clutch device, between the input shaft connecting to the outer ring and the engine connecting to the front wheel propeller shaft, a retainer to disengage the engaging element by relative rotation of the input shaft to the outer ring and the input shaft Incorporating, the cage and the rear wheel propulsion shaft are connected so as to be able to rotate together through a clearance in the rotational direction,
The rear wheel propulsion shaft and input shaft are arranged along the axis of both,
Toe that elastically holds both at the neutral position in the rotational gap
The rear wheel propulsion shaft and a lock member that engages with and disengages from the input shaft to prevent rotation are provided, and the clutch device on the front wheel side is provided between the wheel hub of the front wheel and the axle. A retainer for engaging and disengaging the engaging element with the wheel hub and the axle by relative rotation of the axle is incorporated, and the retainer and the axle are rotatably connected via a clearance in the rotational direction, and a rotational difference between the retainer and the axle. Is provided by providing a differential means for generating

[0007] The present invention also provides a transfer device according to the above structure, wherein an input shaft and an outer shaft of the clutch device on the transfer side are provided.
This adopts a structure in which a tuning device is provided to make the rotations close to each other.

[0008]

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 front wheel-side clutch device, the wheel hub overruns with respect to the engaging element, and only the front wheel is driven. It is separated from the drive path and rotates.

In the two-wheel drive state, when the connection between the input shaft and the rear wheel propulsion shaft by the lock member is released and the front wheel drive shaft (front wheel axle) is rotated, in the front-wheel side clutch device, the differential means Due to the action, the retainer and the axle rotate relative to each other by the clearance in the rotational direction, the engaging element integrates the wheel hub and the axle, and automatically switches to the four-wheel drive state.

At this time, when 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 connected to each other, and the drive switching can be performed without impact.

[0013]

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 is incorporated in a connection portion between the axle G and the front wheel J. In the drawings, K is a rear wheel, and L is a switching lever shared with an auxiliary transmission provided in a driver's seat or the like.

FIGS. 2 to 5 show a first clutch device H provided on the transfer side. In FIG. 2, 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. 3, 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, a plurality of engagement grooves 11 are formed in the distal end portion of the input shaft 2 in the circumferential direction as shown in FIGS. 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 L. 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. 5, 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.

6 to 8 show a second clutch device I provided on the front wheel side. In the second clutch device I, as shown in FIG.
A knuckle 3 that is fixed to the vehicle body except for its tip
The wheel hub 34 of the front wheel J is rotatably supported on the knuckle 32 via bearings 33, 33.

The wheel hub 34 is composed of a front member 35 and a rear member 36 connected via bolts 37, and a tire wheel 38 and a brake device 39 are mounted on the rear member 36. Further, a cap 40 for waterproofing and dustproofing is attached to the front member 35 at the distal end, and an outer ring 41 for a clutch is fixed to the inner peripheral surface by press fitting.

On the peripheral surface of the axle 31 facing the outer race 41, the inner race 4 for the clutch is formed by fitting a serration groove.
2 are integrally attached, and cylindrical engaging surfaces 43 and 44 with which sprags 45 as engaging elements are respectively engaged are formed on opposing surfaces of the inner ring 42 and the outer ring 41.

A large-diameter rotatable control retainer 46 and a small-diameter fixed retainer 47 fixed to an operating pin 48 attached to the inner race 42 are incorporated between the engagement surfaces 43 and 44. The tip of the operating pin 48 is inserted through a pin hole 49 provided in the control holder 46.

As shown in FIG. 7, the control cage 46 and the fixed cage 47 have a plurality of pockets 5 facing each other in the circumferential direction.
Each of the pockets 50 and 51 has a sprag 45 and an elastic member 52 for holding the sprag 45 at a neutral position.

The sprag 45 is formed with an arcuate surface 53 having a center of curvature on the center line of the sprag on the outer diameter side and the inner diameter side in the same manner as in the first clutch device described above. The axle 31 and the wheel hub 34 are integrated with each other by engaging the engagement surfaces 43 and 44.

On the other hand, a differential bearing 55 attached to the axle 31 via a holder 54 is connected to the rear end of the control retainer 46. In this differential bearing 55, the radial clearance is set to zero or less, a preload greater than a predetermined pressure is applied to set a large rotational moment during rolling, and the rotational resistance decelerates the control retainer 46 by the rotational resistance. It has a function of constantly rotating the control retainer 46 with respect to the axle 31 with a delay.

As shown in FIG. 8, an operating pin 48 for passing the inner race 42 and the retainers 46 and 47 is integrally fixed to the inner race 42 and the fixed retainer 47 without any gap. The retainer 46 is loosely fitted to the pin hole 49 with a clearance Y in the rotational direction. This rotational direction gap Y
Determines the delay angle of the control retainer 46 with respect to the axle 31, the size of which is determined by the sprag 45 from the neutral position between the inner and outer rings 41, 42 via the elastic member 52 via the two engaging surfaces 43,
The distance is set to be larger than the distance until the contact is made.

The driving force transmission device of this embodiment has the above-described structure, and its operation will now be described according to various running conditions.

(A) As shown by the broken line in FIG. 2, when the lock member 13 is separated from the input shaft 2 in the first clutch device H and the rotation is applied from the engine B to the input shaft 2 in this state, the rear wheels are rotated. Since a rotational resistance is applied to the propulsion shaft D from the rear wheel that touches the road surface, the torsion bar 10 is deformed, and the input shaft 2 and the rear wheel propulsion shaft D rotate relative to each other, so that the control retainer 16 and the fixed retainer 17 are rotated. Moves relative to each other.

For this reason, the sprags 20 have both 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 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 46 that is 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 axle G, and the rotation relative to the fixed retainer 47 is performed. These two retainers 46, 47
The sprags 45 are inclined in the opposite direction to the rotation direction of the axle G by the relative rotation of the axles G, and come into contact with the engagement surfaces 43 and 44 to be engaged.

In this case, since the elastic member 52 attached to the control retainer 46 always holds the sprag 45 in a pressed state, all the sprags 45 are engaged before the operation pin 48 and the peripheral wall of the pin hole 49 come into contact with each other. The axle G and the control retainer 46 rotate together in this state.

When the axle G continues to rotate from the above state and a difference in rotation occurs between the wheel hub 34 and the wheel hub 34, the sprag 45 immediately engages with the engagement surfaces 43 and 44 and the outer ring 4
1 and the inner ring 42 are integrated. 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 wheels rotate faster than the rear wheels due to turning at a tight corner or the like, in the second clutch device I, the rotation of the wheel hub 34 exceeds the rotation of the axle G. In this state, the outer ring 41 overruns the sprag 45, so that the sprag 45 does not engage with the engagement surfaces 43 and 44. For this reason, the axle G and the wheel hub 34 rotate while being separated from each other, and the two wheels are driven only by the rear wheels, so that the movement of the front wheels is not restricted and the braking phenomenon at a tight corner does not occur.

(C) In the state of two-wheel drive by 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 is released in the four-wheel drive state, no effective driving force is transmitted to the front wheels due to the differential function of the front differential E, but the rear wheels are transmitted via the first clutch device H. , 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 L,
As shown by a solid line in FIG. 1, 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 this two-wheel drive state, transfer A
The outer wheel 1 and the front wheel propulsion shaft C do not rotate, and the axle G is in a stopped state.
The wheel hub 34 of the front wheel overruns the sprag 45, and the front wheel J and the axle G are separated. For this reason, the front wheel J rotates while rotating around the rear wheel K, and all the drive paths of the front wheels from the axle G to the front differential E and the front wheel propulsion shaft C are stopped.

(E) When the lock member 13 of the first clutch device H is disengaged from the two-wheel drive state and the fixed state of the input shaft 2 and the rear wheel propulsion shaft D is released, the torsion bar 10 causes torsion. The return function works, and the sprags 20 engage the input shaft 2 and the outer ring 1 to rotate the front wheel propulsion shaft C.

In this case, when the axle G rotates, in the second clutch device I, the retainer 46 and the axle G rotate relatively by the action of the differential bearing 55, and the sprags 45 integrate the wheel hub 34 and the axle G. . Therefore, the mode is automatically switched to four-wheel drive.

At the time of the above-mentioned switching, the front wheel J becomes the rear wheel K
Therefore, even if the axle G in the rotating state is engaged with the front wheel hub 34 by the second clutch device I, there is no torque load, and smooth switching can be performed even during running. it can.

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. Since the engagement can be performed at a free position, a smooth connection can be performed.

In the above description, the operation in one direction of the vehicle has been described. However, when the rotation direction applied from the transmission to the input shaft 2 is reversed, the inclination of the sprags 20 and 45 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 L, the lock member may be operated by another mechanical mechanism or an electrical mechanism.

FIG. 9 shows an example in which a tuning device 61 is provided between the outer ring 1 and the input shaft 2 in the first clutch device H to make the rotational speeds of the two close together.

The tuning device 61 comprises an operating member 63 movably provided in an engaging groove 62 on the outer diameter surface of the input shaft 2 and a friction material 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. 10 and 11 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 retainer 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 relatively, 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.

On the other hand, FIG. 12 shows an example in which a roller is used in the second clutch device instead of the sprag for the clutch engagement element. In this example, a cylindrical engagement surface 92 is formed on an outer ring 91 attached to the wheel hub 34, and the axle G
A plurality of engaging surfaces 94 forming a wedge-shaped cam surface with respect to the above-mentioned engaging surface 92 are provided on the outer peripheral surface of the inner ring 93 attached to the inner ring 93.

An annular retainer 95 is incorporated between the engaging surface 92 and the engaging surface 94, and a pair of rollers 97, 98 and the rollers 9 are mounted in a pocket 96 provided in the retainer 95.
An elastic member 99 is incorporated which presses the 7, 98 against the opposing side surfaces of the pocket 96 and holds it in the neutral position.

In this case, although not shown, the retainer 95
The operation pin protruding from the inner ring 93 is loosely fitted in the pin hole provided in the above, and the differential bearing is connected to the retainer 95.

In the above structure, when the retainer 95 rotates in the left-right direction with respect to the axle G, one of the rollers 97 and 98 alternately engages with the engagement surfaces 92 and 94, and the axle G and the wheel hub 34 are rotated. Are integrated.

It should be noted that the clutch engagement member may be used by incorporating a pair of left and right sprags engaged in one direction of rotation between the engagement surfaces.

The differential means for providing a rotational difference between the cage and the axle is not limited to the differential bearing 55 described above, but may be a gear differential speed mechanism, a brake mechanism for decelerating by sliding contact with a friction member, or the like. Can also be used.

[0058]

As described above, the driving force transmission device of the present invention
A clutch device that switches the engagement depending on the speed difference between the input and output is provided at the junction between the transfer branch and the front wheel, so that the drive switching between the four wheels and the two wheels can be automatically performed. In the case of two-wheel drive with rear wheels, the drive path on the front wheel side can be stopped, and in the case of four-wheel drive, the front wheels can be automatically coupled to the drive path, so that fully automatic four-wheel drive with excellent fuel efficiency and noise performance Driving 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 a longitudinal sectional front view showing a first clutch device of the embodiment.

FIG. 3 is a sectional view taken along the line III-III in FIG. 2;

FIG. 4 is a sectional view taken along the line IV-IV in FIG. 2;

FIG. 5 is a sectional view showing an operation state of the sprag according to the first embodiment;

FIG. 6 is a longitudinal sectional front view showing a second clutch device of the embodiment.

FIG. 7 is a sectional view taken along the line VII-VII of FIG. 6;

FIG. 8 is a sectional view taken along the line VIII-VIII in FIG. 6;

FIG. 9 is a longitudinal sectional front view showing another embodiment.

FIG. 10 is a longitudinal sectional front view showing another example of the first clutch device.

11 is a sectional view taken along the line XI-XI in FIG.

FIG. 12 is a sectional view showing another example of the second clutch device.

[Explanation of symbols]

 Reference Signs List A Transfer C Front wheel propulsion shaft D Rear wheel propulsion shaft E Front differential G Axle H First clutch device I Second clutch device 1, 71 Outer wheel 2, 72 Input shaft 10 Torsion bar 16 Control retainer 17 Fixed retainer 20 Sprag 34 Wheel Hub 45 sprag 46 control retainer 47 fixed retainer 55 differential bearing 61 tuning device 75 retainer 77 roller 79 elastic ring 95 retainer 97, 98 roller

──────────────────────────────────────────────────続 き Continuation of the front page (56) References JP-A-61-77528 (JP, A) JP-A-63-255126 (JP, A) JP-A-5-4538 (JP, A) JP-A-4- 328026 (JP, A) Japanese Utility Model Showa 60-96127 (JP, U) Japanese Utility Model Showa 61-196826 (JP, U) Japanese Utility Model Showa 62-156535 (JP, U) (58) Field surveyed (Int. ⁷ , DB name) B60K 23/00-23/08 B60K 17/28-17/36

Claims (2)

(57) [Claims] 1. A driving force transmission device for a vehicle in which a clutch device is provided at a branch portion between a front wheel propulsion shaft and a rear wheel propulsion shaft of a transfer, and a coupling portion between a front wheel and an axle, wherein the clutch device on the transfer side comprises a front wheel. A retainer for engaging and disengaging the engaging element between the outer ring and the input shaft by relative rotation with the input shaft is incorporated between the outer ring connected to the propulsion shaft and the input shaft connected to the engine, and the retainer and the rear wheel propulsion shaft are incorporated. And the rear wheel propulsion shaft and the input shaft are arranged along the axis of both, so that both can rotate.
Torsion to hold elastically in neutral position in rolling gap
The rear wheel propulsion shaft and the lock member for engaging and disengaging the input shaft to prevent rotation are provided, and the clutch device on the front wheel side is provided between the wheel hub of the front wheel and the axle. A retainer for engaging and disengaging the engaging element with the wheel hub and the axle by relative rotation of the axle is incorporated, and the retainer and the axle are rotatably connected via a clearance in the rotational direction, and a rotational difference between the retainer and the axle. A driving force transmitting device for a vehicle, characterized in that the driving force transmitting device is provided with a differential means for generating the force. 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.