JPH09202153A - Rotation transmission device of four wheel drive - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide a device to mechanically changeover transmission of the drive force during the acceleration and shut-off of the drive force during the braking to a rear wheel of a four wheel drive. SOLUTION: Differential gears or a differential limitting device and an internal member 23 are connected to a rear wheel propeller shaft in series, a cylindrical surface and a cam surface 27 forming a wedge-shaped space are formed on the opposite plate to an outer wheel 21 to be connected to the internal member 23 and the rear wheel, a roller 30 of an engagement element is assembled with a pocket 29 of a holder 28 provided therebetween, and a unidirectional ratchet is connected to the holder 28. A coil spring 33 to give the rotational resistance is fitted between the holder 28 and the internal member 23, the direction of the rotational resistance to be applied to the holder 28 is changed by operating the unidirectional ratchet, the delay direction of the holder to the internal member 23 is changed over to set the roller 30 in the engaging condition in the forward/reverse rotational direction.

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a rotation transmitting device for transmitting a driving force to rear wheels of a four-wheel drive vehicle, and more specifically, to transmitting a driving force during acceleration and a driving force during braking in a four-wheel drive vehicle. The present invention relates to a rotation transmission device used for switching between interruptions.

[0002]

2. Description of the Related Art Conventionally, a four-wheel drive vehicle (hereinafter referred to as 4WD) that enhances driving force and running performance at the time of starting and accelerating has a differential limiting device such as a center differential or a viscous coupling provided between its front and rear shafts. However, the combination of such a differential limiting device and an anti-lock brake system (hereinafter referred to as ABS) that improves braking force and steering stability during braking is such that four-wheel lock and vehicle body vibration are likely to occur. Are not compatible with each other in terms of controllability and the rotational restraint force between the wheels of the drive system.

As a means for solving this problem, the present applicant has proposed a rotation transmission device for a four-wheel drive vehicle for ABS in Japanese Patent Application No. 5-137736.

In this rotation transmitting device A, as shown in FIG. 10, an inner member 3 which is a driving member is rotatably fitted inside an outer ring 1 which is a driven member via a bearing 2 to form an inner member. Three
Attach the input ring 4 to the end of the via spline,
An engaging member 5 that allows the both to be coupled in a rotational direction is incorporated between the inner member 3 and the outer ring 1, and a one-way clutch 7 is incorporated between a retainer 6 of the engaging member 5 and the inner member 3, 7
Is connected to the rotation resistance applying means 9 via the input ring 8.

The rotation resistance applying means 9 rotatably instructs the housing 11 which is fixed to the vehicle body of an automobile or the like via the connecting rod 10 by the outer ring 1 and the inner member 3 via bearings, and is press-fitted into the housing 11. Friction pad 13 and input ring 8
The structure is such that the input ring 8 which tries to rotate together with the retainer 6 is rubbed by the elastic force of the disc spring 16 compressed between the flange 14 and the retaining ring 15 to delay its rotation. ing.

As shown in FIG. 11, the rotation transmission device A described above connects the inner member 3 to the fluid coupling C between the fluid coupling C of the rear wheel propulsion shaft B and the rear differential D, and connects the outer ring 1 to the outer ring 1. Connect to the rear differential D in series.

In the above structure, when the vehicle travels forward, the cage 6 rotates later than the inner member 3 due to the rotation resistance (elastic member), and the relative rotation thereof causes the engaging element 5 to rotate.
Is engaged. Conversely, when the vehicle runs backwards,
The one-way clutch 7 is actuated to switch the delay direction of the retainer 6, and the engagement element 5 is similarly engaged.

When the vehicle travels straight forward or backward in the above engagement operation state, the front wheel, the rear wheel and the rear wheel propulsion shaft rotate at the same speed, so that the engagement element 5 maintains the engagement standby state. For this reason, it is a two-wheel drive with only the front wheels.

On the other hand, when the front wheels slip during traveling, the rotation of the rear-wheel propulsion shaft is increased with respect to the rear wheels, and the engaging elements 5 are engaged, so that the driving force is transmitted to the rear wheels and the state is switched to the four-wheel drive state.

On the contrary, when the vehicle suddenly brakes and the front wheels try to lock, the rear wheel propulsion shaft suddenly decelerates due to the front wheel lock, but the rotation of the rear wheel (outer wheel 1) is caused by the rear wheel propulsion shaft. Since the rotation exceeds the rotation, the inner member 3 and the outer wheel 1 run idle, and the deceleration force due to the front wheel lock is not transmitted to the rear wheel. As described above, since no binding force is generated between the rear wheel and the front wheel to be locked, ABS control becomes easy as in the case of the 2WD vehicle.

[0011]

By the way, in the above-described rotation transmitting device, the phases of the retainer and the input shaft are switched depending on the rotation direction, and the drive and idling can be performed in both rotation directions. Therefore, the internal structure is complicated, and there are some parts that are fixed to the vehicle body and do not rotate.
There was room for improvement in weight, number of parts, cost, and mounting method.

Therefore, an object of the present invention is to transmit a driving force during acceleration and to automatically shut off the restraining force of the front and rear wheels during ABS operation, and eliminate the above-mentioned vehicle body fixing portion, It is to provide a compact and low-priced rotation transmission device.

[0013]

In order to solve the above-mentioned problems, the invention of claim 1 has a drive member connected in series to a rear wheel propulsion shaft of a four-wheel drive vehicle and a differential limiting device, and a rear member. The driven member connected to the wheel axle is rotatably fitted in and out,
A retainer is provided between the facing surfaces of the drive member and the driven member, and the pocket formed in the retainer engages the drive member and the driven member when the retainer and the drive member relatively rotate in the forward and reverse directions. A structure is adopted in which an engaging element is incorporated and a one-way ratchet for connecting and disconnecting the retainer and the driven member in the rotational direction is provided between the retainer and the driven member.

According to a second aspect of the present invention, a drive member that is connected to the rear wheel propulsion shaft of the four-wheel drive vehicle in series with the differential limiting device and a driven member that is connected to the rear wheel axle are rotatably fitted in and out. A cage is provided between the opposing surfaces of the drive member and the driven member, and the drive member and the driven member are provided in a pocket formed in the cage when the cage and the driving member relatively rotate in the forward and reverse directions. Between the drive member and the retainer, a rotation transmitting mechanism formed by incorporating an elastic member that applies a relative rotation imparting force to the drive member and the retainer, and between the retainer and the driven member are provided. The configuration adopts a configuration in which one-way ratchets for respectively connecting and disconnecting the retainer and the driven member in the rotational direction are provided.

According to a third aspect of the present invention, in the first or second aspect of the present invention, the one-way ratchet is provided with one of the retainer and the driven member having a claw portion protruding in the radial direction.
A fulcrum is fixed to the other of the retainer or the driven member, a weight member rotatable about the fulcrum is provided, and an elastic member for pushing the weight member in the radial contraction direction is incorporated, and the weight member is partially attached to the above-mentioned member. The configuration is such that a concave portion that engages with the claw portion is provided.

According to a fourth aspect of the present invention, in the third aspect of the present invention, the fulcrum of the weight member has a friction force larger than the urging force of the elastic member incorporated between the retainer and the drive member, or the retainer or the driven member. The configuration is such that the member is pressed and fixed to the member.

[0017]

Embodiments of the present invention will be described below with reference to the drawings.

In the first embodiment shown in FIGS. 1 to 5, an inner member 23, which is a driving member, is rotatably fitted into an outer ring 21, which is a driven member, through a bearing 22, and the inner member 23 An input ring 25 is attached to the end of the member 23 via a spline 24.

A cylindrical surface 26 is formed on the inner diameter surface of the outer ring 21, and a plurality of flat cam surfaces 27 are formed on the outer diameter surface of the facing inner member 23 at predetermined intervals. Each cam surface 2
7 and the cylindrical surface 26 of the outer ring 21 form a wedge-shaped space in which both sides in the circumferential direction are narrowed.

Further, between the outer ring 21 and the inner member 23,
An annular retainer 28 is provided, and the same number of pockets 29 as the cam surface 27 are formed in the retainer 28 in the circumferential direction, and a roller 30 as an engaging element is incorporated in each pocket 29. The roller 30 is provided on each cam surface 27 of the inner member 23.
One is installed for each of the
When a predetermined amount is moved in the circumferential direction by 8, the cam surface 27 and the cylindrical surface 26 are engaged with each other, and the outer ring 21 and the inner member 23 are integrated.

A ratchet, which will be described later, is fitted to the end of the cage 28 so as not to rotate relative to each other. A retaining hole 31 is provided in the flange portion of the retainer 28, and each end of the ring spring 33 is retained between the retaining hole 32 of the inner member 23 and the retaining hole 32. As a result, a biasing force that causes the retainer 28 to rotate in the direction opposite to the rotation direction of the inner member 23 is applied.

On the other hand, the ratchet 34 fitted to the end of the cage 28 is connected to the outer ring 21 via a weight 35 and a weight house 36 to form a one-way ratchet.

A plurality of claws 37 are formed on the outer circumference of the ratchet 34. The weight house 36 is the outer ring 21.
The plurality of weights 35 formed in an arc shape are press-fitted and fixed to each other, and the rear ends of the weights 35 are rotatably fitted and supported by a column 38 that is press-fitted and fixed to a weight house 36.
A concave portion 39 that engages with the claw 37 of the ratchet 34 is formed at the tip of 5.

Further, a tension coil spring 41 is locked between the pin 40 provided at the tip of each weight 35 and the strut 38 of the opposing weight 35 to urge the tip of each weight 35 toward the center. There is.

In the above structure, when the cage 28 is rotated relative to the outer ring 21 in the arrow (b) direction of FIG. 4 by the driving of the inner member 23 and the ring spring 33, the ratchet fitted to the cage 28. 34 is the recess 39 of the weight 35.
When it is further rotated, the rotation of the retainer 28 is stopped against the ring spring 33 and is decelerated with respect to the rotation of the inner member 23. When the inner member 23 further rotates, the roller 30 engages, and the inner member 23 and the outer ring 21 are integrated.

On the contrary, as shown in FIG. 3, when the cage 28 together with the inner member 23 rotates relative to the outer ring 21 in the direction (a), the ratchet 34 is disengaged, and the weight 35 moves to the cage 28. Although no resistance is applied, since the ring spring 33 gives a rotational force to the retainer 28 in the opposite direction to the above (a) direction, the retainer 28 is decelerated by the spring force and the roller 30 is engaged, The inner member 23 and the outer ring 21 are integrated.

Further, as shown in FIG. 5, when the rotation of the entire apparatus rises and the centrifugal force applied to the weight 35 overcomes the urging force of the tension coil spring 41 and expands to the weight house 36 side, the retainer 28 causes the outer ring to move. 21 with respect to FIG.
Claw 3 of ratchet 34
Since the 1 and the recess 39 of the weight 35 are not locked, the roller 30 is not engaged, and the inner member 23 can idle in the (b) direction with respect to the outer ring 21.

The rotation transmission device A of the first embodiment is constructed as described above and is applied to the rear wheel drive path of a four-wheel drive vehicle in which the front wheels are the main drive wheels, as shown in FIG. To be done.

That is, a fluid coupling such as a viscous coupling, which is a differential limiting device, and an input ring 25 of the inner member 23 are connected in series to the rear wheel propulsion shaft coming out of the transfer, and the outer ring 21 is provided with a rear differential. Connect D.

The direction of rotation of the inner member 23 when the vehicle is traveling forward and the direction of arrow (a) in FIG. 3 (the direction in which the ratchet is cut off) coincide with each other, and the direction of rotation during reverse and the arrow of FIG. 4 ( B) direction (direction in which the ratchet locks)
Set so that and match.

Considering the actual running of the vehicle in this state, while the vehicle is running straight forward or backward in a normal state, the front wheels, the rear wheels and the rear wheel propulsion shafts that rotate with the front wheels are in motion. Since the rollers 30 rotate at the same speed, the rollers 30 maintain the engagement standby state. For this reason, it will be a two-wheel drive with only the front wheels.

When the vehicle turns to have a steering angle and the front wheels rotate faster than the rear wheels, the rotation of the inner member 23 increases, so that the rollers 30 engage the cylindrical surface 26 and the cam surface 27. Then, the outer ring 21 and the inner member 23 are integrated, and further,
The front wheel is allowed to rotate faster than the rear wheel while transmitting the driving force to the rear wheel by the differential limiting action of the fluid coupling on the rear wheel propulsion shaft. Therefore, the vehicle is in the 4WD state during turning.

On the other hand, if the front wheels slip during acceleration,
Since the rotation of the rear wheel propulsion shaft increases with respect to the rear wheel (outer wheel),
The roller 30 engages the cylindrical surface 26 and the cam surface 27, and the outer ring 2
1 and the inner member 23 are integrated. Therefore, when the front wheels slip, the state changes to the 4WD state.

On the contrary, in the case of sudden braking, if the friction coefficient of the road surface is low, the vehicle generally tries to lock the front wheels. At this time, the rear-wheel propulsion shaft (inner member) suddenly decelerates as the front wheel locks, but by the way, the set speed (10 km / h to 20 km).
/ H) or more, the weight 35 does not mesh with the ratchet 34, and the outer ring 21 and the inner member 23 idle,
It does not transmit the deceleration force associated with the front wheel lock to the rear wheels. Therefore, since there is no binding force between the rear wheel that does not lock and the front wheel that tries to lock, the ABS control can detect the difference in the rotational speeds of the front and rear wheels, and the ABS control can be performed as easily as a 2WD vehicle.
Control becomes possible.

If the speed decelerates below the set speed, the weight 35 meshes with the ratchet 34, so that the outer ring 21 and the inner member 23 do not idle. However, if the ABS operates at such a speed, the braking distance may become longer on the contrary, and it is often set such that the ABS itself does not operate at such a low speed. Therefore,
It is not necessary to block the front and rear wheels at such low speeds.

Next, FIGS. 6 to 8 show a second embodiment of the present invention. The same parts as those in the first embodiment are denoted by the same reference numerals and will not be described.

In contrast to the first embodiment, the second embodiment has the outer ring 21 on the input side and the inner member 23 on the output side.

A plurality of cam surfaces 27 having a polygonal shape are formed on the inner diameter surface of the outer ring 21, and the inner member 23 opposed to the cam surfaces 27.
A cylindrical surface 26 is formed on the outer diameter surface of the, and an annular cage 28 is incorporated between the cylindrical surface 26 and the cam surface 27. The cage 28 is rotatably fitted to the outer ring 21, and a roller 30 that engages in a forward and reverse direction is incorporated in a pocket 29 provided on the peripheral surface of the cage 28.

A housing portion 41 is provided at an end portion of the retainer 28, and a weight 35 is rotatably mounted on a column 38 fixed to the housing portion 41.

A retaining hole 31 is provided in the flange portion of the retainer 28, and the ring spring 3 is provided between the retaining hole 31 and the retaining hole 42 of the outer ring 21.
Each end of 3 (switch spring) is locked,
The spring force of the ring spring 33 urges the retainer 28 against the outer ring 21 in the direction opposite to the rotational direction.

A ratchet 34 is fixed to the shaft portion of the inner member 23, and the pawl 37 formed on the outer peripheral portion of the ratchet 34 and the recess 39 formed on the weight 35 mesh with each other.

A tension coil spring 41 is locked between a pin 40 provided on the weight 35 and a column 38 of the weight 35 facing each other, and urges the tip of each weight 35 toward the center.

The rotation transmitting device A'of the second embodiment.
As shown in FIG. 8, the outer ring 21 has a fluid coupling C.
And the inner member 23 is connected to the rear differential D.

The operation of the second embodiment is the same as that of the first embodiment described above, in which the rotation of the outer ring of the first embodiment is the rotation of the inner member in the second embodiment, and ,
The rotation of the inner member of the first embodiment is the same as that of the first embodiment except that the rotation of the inner member is changed to the outer ring in the second embodiment.

FIG. 9 shows a third embodiment. In the rotation transmission device A ″ of the third embodiment, while the weight house 36 and the outer ring 21 are press-fitted and fixed in the first embodiment, the weight house 36 is rotatably fitted in the outer ring 21. Then, the weight house 36 and the outer ring 21 are frictionally fixed using an elastic member such as a stop ring 51 fixed to the outer ring 21 and a disc spring 52 compressed between the end surfaces of the weight house 36. The frictional force is It is set to be larger than the spring force of the ring spring 38.

As a result, it is possible to prevent impact relaxation when the one-way ratchet meshes and to prevent stress concentration on each component.

Although not shown, instead of frictionally fixing the outer ring 21 and the weight house 36, the ratchet 34 is used.
Even if the cage 28 is fixed by friction, the same effect can be obtained.

Furthermore, in each embodiment, the weight 3
The elastic member 41 for urging 5 toward the center may not be a tension coil spring as in the first embodiment, but a leaf spring may be incorporated on the outside of the weight or a garter spring may be wound on the outside of the weight. Even if the mounting positions of the differential limiting device and the rotation transmitting device are interchanged in the drive path of FIG. 8, the same function as described above is exerted if they are connected in series to the rear wheel propulsion shaft.

[0049]

As described above, according to the present invention, regardless of whether the vehicle is moving forward or backward, the driving torque is transmitted to the rear wheels during acceleration to make 4WD, and the front wheels are driven at a speed at which the ABS operates during sudden braking. When slipping toward the lock, the rotation restraint force is not transmitted to the rear wheels due to the idling function of the mechanical clutch, and the rotation speed difference between the front and rear wheels can be changed independently of each other as in a 2WD vehicle. Therefore, it is possible to easily install the ABS function, which has been poorly compatible with the 4WD vehicle in the past, similarly to the 2WD vehicle.

Further, by utilizing the centrifugal force and the one-way ratchet as the driving direction of the device, there is no fixed part to the vehicle body, and the size, weight, number of parts, cost, mountability, oil seal are different from those of the conventional device. All durability improved.

[Brief description of drawings]

FIG. 1 is a vertical sectional view showing a first embodiment of the present invention.

2A is a cross-sectional view taken along arrow aa in FIG. 1, and FIG. 2B is a cross-sectional view taken along arrow bb in FIG.

FIG. 3A is a cross-sectional view showing the operating state of FIG.
FIG. 2B is a sectional view showing the operating state of FIG.

4A is a cross-sectional view showing the operating state of FIG. 2A,
FIG. 2B is a sectional view showing the operating state of FIG.

5A is a cross-sectional view showing the operating state of FIG. 2A,
FIG. 2B is a sectional view showing the operating state of FIG.

FIG. 6 is a vertical sectional view showing a second embodiment of the present invention.

7A is a sectional view taken along arrow aa in FIG. 6, and FIG. 7B is a sectional view taken along arrow bb in FIG.

FIG. 8 is a plan view schematically showing a drive path of a vehicle equipped with the same as above.

FIG. 9 is a longitudinal sectional view showing a third embodiment of the present invention.

FIG. 10 is a vertical cross-sectional view showing a conventional rotation transmission device.

FIG. 11 is a plan view schematically showing a drive path of a vehicle equipped with the same as above.

[Explanation of symbols]

 21 Outer Ring 23 Inner Member 26 Cylindrical Surface 27 Cam Surface 28 Cage 29 Pocket 30 Roller 33 Ring Spring 34 Ratchet 35 Weight 36 Weight House 37 Claw 38 Strut 39 Recess 40 Pin 41 Coil Spring 51 Stop Ring 52 Disc Spring

Claims (4)

[Claims] 1. A drive member that is connected in series to a rear wheel propulsion shaft of a four-wheel drive vehicle and a driven member that is connected to a rear wheel axle, and a driven member that is rotatably fitted in and out to drive the same. A retainer is provided between the facing surfaces of the member and the driven member, and a pocket formed in the retainer engages the drive member and the driven member when the retainer and the drive member relatively rotate in the forward and reverse directions. And a unidirectional ratchet for connecting and disconnecting the retainer and the driven member in the rotational direction between the retainer and the driven member. 2. A drive member that is connected in series with a differential limiting device to a rear wheel propulsion shaft of a four-wheel drive vehicle and a driven member that is connected to an axle of the rear wheel are rotatably fitted in and out to drive the same. A retainer is provided between the facing surfaces of the member and the driven member, and a pocket formed in the retainer engages the drive member and the driven member when the retainer and the drive member relatively rotate in the forward and reverse directions. A rotation transmission mechanism formed by incorporating an elastic member for applying a relative rotation imparting force between the drive member and the retainer, and the retainer and the driven member between the retainer and the driven member. A rotation transmission device for a four-wheel drive vehicle, each of which is provided with a one-way ratchet for connecting and disconnecting the rotation direction of the vehicle. 3. A one-way ratchet, wherein one of the retainer and the driven member is provided with a claw portion protruding in the radial direction, a fulcrum is fixed to the other of the retainer and the driven member, and the ratchet rotates about the fulcrum. A weight member capable of being provided, an elastic member for pushing the weight member in a diameter reducing direction is incorporated, and a recess for engaging the claw portion is provided in a part of the weight member. A rotation transmission device for a four-wheel drive vehicle as described above. 4. The fulcrum of the weight member is press-contacted and fixed to the retainer or the driven member with a frictional force larger than the urging force of the elastic member incorporated between the retainer and the driving member. Rotation transmission device for four-wheel drive vehicles.