JP4790361B2 - Differential limiter - Google Patents

Description

  The present invention relates to a differential limiting device, and more particularly to a differential limiting device incorporated in a differential device between drive wheels of a vehicle, such as a front differential, a rear differential, and a center differential.

In general, a differential limiting device (limited slip differential) is incorporated in a differential device such as a front differential, a rear differential, or a center differential, and one of the drive wheels is idled on a road surface with a small coefficient of surface friction, such as muddy, sandy, and frozen roads. Or a differential limiting mechanism that prevents driving performance from being deteriorated by transmitting driving torque to the remaining driving wheels when one of the driving wheels floats during turning.
Conventionally, in such a differential limiting device, the turning state of the vehicle is determined based on the detection value detected by the lateral G sensor, and the engagement force of the friction multi-plate clutch is finely electronically controlled according to the turning state of the vehicle. By doing so, the differential limiting mechanism part which performs the differential control (torque distribution control) of a driving wheel is provided (for example, refer patent document 1).

  However, in the above-described conventional differential limiting device, the lateral G sensor and the electronic control unit for finely electronically controlling the fastening force of the friction multi-plate clutch have high component costs. For this reason, there is a problem that the adoption of the lateral G sensor and the electronic control unit causes an increase in vehicle cost. Further, the lateral G sensor and the electronic control unit may cause a circuit failure, disconnection, and the like, and there is a problem that differential control becomes unstable when they occur.

JP 09-193686 A

  Therefore, the present invention has been made to solve the above-described problems of the prior art, and is intended to reduce the cost of parts and always provide a differential limit with high stability and reliability. An object of the present invention is to provide a differential limiting device that can be performed.

The first invention for achieving the above object, a differential limiting device incorporated in the differential between the driving wheels of the vehicle,
When the lateral G is generated, the link mechanism that swings outward in the turning direction by the weight receiving the lateral G causes the swing motion to act as a pressing load, so that the differential between the left and right or front and rear drive wheels can be obtained. A lateral G-sensitive mechanical differential limiting mechanism for transmitting a driving torque to the left and right or front and rear driving wheels by fastening a multi-plate clutch for limiting is provided.

  To achieve the above object, according to a second invention, in the first invention, when one of the left and right or front and rear driving wheels idles, the driving force transmitting member that rotates together with the differential case that is driven to rotate by the engine driving force. Presses the pair of left and right pressure rings to engage the multi-plate clutch, thereby reducing the driving torque of the idling driving wheel and increasing the driving torque of the non-idling driving wheel. It is characterized by comprising a type differential limiting mechanism.

  According to the first and second inventions, the lateral G-sensitive mechanical differential limiting mechanism portion of the differential limiting device of the differential limiting device has many link mechanisms that operate according to the lateral G when the lateral G occurs. The plate clutch is engaged, and the driving torque is transmitted to the left and right or front and rear driving wheels. Further, the torque-sensitive mechanical differential limiting mechanism of the differential limiting device is configured to transmit a driving force that rotates with a differential case that is rotated by an engine driving force when one of the left, right, or front and rear driving wheels idles. The member pushes the pair of left and right pressure rings to fasten the multi-plate clutch, thereby reducing the driving torque of the idling driving wheel and increasing the driving torque of the non-idling driving wheel. Thereby, the traction of all the driving wheels at the time of escape from the corner can be secured, the turning performance can be further improved, and the escape performance at the time of stacking and the stability at the time of straight running can be secured. In addition, since any differential limiting mechanism portion operates mechanically, the operation response can be improved and the vehicle structure can be simplified as compared with the conventional electronic differential limiting mechanism portion. it can. In addition, since electronic components that require high component costs are not used, manufacturing costs can be reduced, operation is reliable, and reliability can be improved.

In order to achieve the above object, a third invention is characterized in that the link mechanism comprises:
A pair of left and right first and second arms projecting rearward from the housing housing the multi-plate clutch so as to be rotatable outward in the turning direction;
A third arm that connects the rear end of the first arm and the second arm, and has left and right ends rotatably attached to the respective rear ends,
A weight is detachably attached to a position that is substantially symmetrical with respect to the link mechanism.

  According to the third aspect of the invention, the link mechanism projects from the housing in which the multi-plate clutch is housed in the longitudinal direction of the vehicle body, and the weight is detachably attached to a position that is substantially symmetrical with respect to the link mechanism. It has been. The link mechanism operates according to the added lateral G, thereby fastening a multi-plate clutch for limiting the differential between the left and right or front and rear drive wheels. As a result, in addition to the operational effects of the first or second invention, when the amount of overhang of the link mechanism or the weight of the weight is changed, the amount of operation when the lateral G is added changes, so the multi-plate clutch is fastened. The fastening force can be easily adjusted.

  When the lateral G occurs, a multi-plate clutch is mechanically engaged to transmit driving torque to the left and right or front and rear driving wheels, and when one of the left and right or front and rear driving wheels idles, The differential limiting device is provided with a mechanical differential limiting mechanism that engages the multi-plate clutch to reduce the driving torque of the idling driving wheel and increases the driving torque of the non-idling driving wheel. Accordingly, it is possible to provide a differential limiting device capable of reducing the component cost and always performing differential limiting with high stability and reliability.

  Hereinafter, an embodiment of the present invention will be described in detail with reference to the drawings. FIG. 1 is a cross-sectional view of a differential device to which a differential limiting device according to the present embodiment is attached, and FIG.

The differential limiting device of the present invention will be described. As shown in FIG. 1, the differential limiting device 10 includes a torque-sensitive mechanical differential limiting mechanism unit 11 and a lateral G-sensitive mechanical differential limiting mechanism unit 12.
The torque sensitive mechanical differential limiting mechanism 11 includes a housing 13, a differential case 14, a ring gear 15, a pair of left and right V-shaped cams (pressure rings) 16, 17, multi-plate clutches 18, 19, and a driving force transmission member. A cross-shaped pinion shaft 20, a plurality of differential bevel pinions 21, and a pair of left and right differential bevel gears (side gears) 22 and 23 are provided.

  A propeller shaft 25 for transmitting a driving force from the engine is rotatably supported by a tapered roller bearing 26 inside the housing 13 that forms an outer shell of the differential (rear differential) 24. A pinion gear 27 is integrally provided at the shaft end of the propeller shaft 25. The ring gear 15 that meshes with the pinion gear 27 is fixed to the differential case 14 by fixing bolts 28, and the differential case 14 is supported by taper roller bearings 29 and 30 at the left and right ends thereof, respectively. The housing 13 can be rotated. Thereby, the differential case 14 is rotationally driven by the driving force from the engine.

  A plurality of fitting grooves (not shown) are integrally formed in the differential case 14, and a pair of left and right pressure rings 16, 17 slides in the vehicle body width direction in these fitting grooves. It is possible to fit. Furthermore, the V-shaped tip of the cross-shaped pinion shaft 20 is supported by the pressure rings 16 and 17 (see FIG. 2), and the shaft ends of the cross-shaped pinion shaft 20 are located inside the pressure rings 16 and 17. A plurality of differential bevel pinions 21 provided integrally with each other are engaged with a pair of left and right differential bevel gears 22 and 23, respectively. A drive shaft (axle drive shaft) 31 for rotationally driving the left drive wheel is spline-fitted to the left differential bevel gear 22 in the drawing, and the right drive wheel is connected to the right differential bevel gear 23 in the drawing. A drive shaft (axle drive shaft) 32 to be driven is spline-fitted.

  Further, multi-plate clutches 18 and 19 are disposed between the differential case 14 and the pressure rings 16 and 17. The multi-plate clutches 18 and 19 are configured by alternately arranging friction plates 18A and 19A fixed to the differential case 14 and friction disks 18B and 19B fixed to the differential bevel gears 22 and 23. Further, on the sides of the multi-plate clutches 18 and 19, spring plates 33 and 34 fixed to the differential case 14 and spring disks 35 and 36 fixed to the differential bevel gears 22 and 23 are alternately arranged. As a result, the multi-plate clutches 18 and 19 are constantly pressurized toward the pressure rings 16 and 17.

  As shown in FIG. 2, the load necessary for the clutch action connecting the differential case 14 and the differential bevel gears 22 and 23 is generated between the pinion shaft 20 and the V-shaped cam contact surfaces of the pressure rings 16 and 17, and the load Is proportional to the drive torque transmitted to the differential case 14. The driving torque transmitted to the differential case 14 is transmitted to the pressure rings 16 and 17, and the differential case 14 and the pressure rings 16 and 17 rotate together. When the pressure rings 16 and 17 try to rotate in the direction of the arrow in the figure, driving torque is transmitted to the pinion shaft 20 supported by the V-shaped cam, and the pressure rings 16 and 17 receive the reaction force. The reaction force pushes and opens the pressure rings 16 and 17 in the left-right direction, and acts as a pressing load for the multi-plate clutches 18 and 19. Thereby, the acceleration / deceleration of the vehicle by the accelerator operation and the timing of engagement of the multi-plate clutches 18 and 19 substantially coincide.

  When there is a rotation difference between the left and right drive wheels (for example, the right drive wheel is idling), the right differential bevel gear 23 that tries to rotate faster than the differential case 14 is caused by the multi-plate clutch 19 pressed by the pressure ring 17. The brake is applied. A part of the driving torque is transmitted to the differential case 14 via the multi-plate clutch 19 from the right differential bevel gear 23 in the braked state. On the other hand, the driving torque is transmitted to the left differential bevel gear 22 which is about to rotate at low speed as the right drive wheel idles, from the differential case 14 which rotates at high speed via the left multi-plate clutch 18. As a result, in addition to the drive torque transmitted from the differential bevel pinion 21 to the left differential bevel gear 22, the drive transmitted from the right differential bevel gear 23 via the left and right multi-plate clutches 18, 19 and the differential case 14. Torque is applied. In other words, the torque-sensitive mechanical differential limiting mechanism unit immediately reduces the drive torque of the idle driving wheel when one of the left and right driving wheels idles during acceleration / deceleration, and the non-idling driving wheel. By increasing the driving torque, the torque is appropriately distributed to the left and right driving wheels in accordance with the change in the driving force of the left and right driving wheels.

  In place of the torque sensitive mechanical differential limiting mechanism using the cross-shaped pinion shaft 20, a torque sensitive cam differential limiting mechanism using a cam can be used. Also, the tip of the cross-shaped pinion shaft 20 is replaced with a two-way shape that generates a pressing load during acceleration / deceleration. It is also possible to use a 1.5-way shape that reduces the pressing load.

  Next, the lateral G-sensitive mechanical differential limiting mechanism 12 will be described. As shown in FIG. 1, the lateral G-sensitive mechanical differential limiting mechanism section 12 includes a link mechanism 37 attached to the torque-sensitive mechanical differential limiting mechanism section 11, a pair of left and right forks 38, 39, and a sleeve. 40, 41, pistons 42, 43, pressure plates 44, 45, and weights 46.

  The link mechanism 37 projects from the housing 13 toward the rear of the vehicle body so as to be U-shaped in plan view, and is supported by the housing 13 so as to be rotatable outward in the turning direction. The first and second arms 37A and 37B are connected to the rear ends of the first and second arms 37A and 37B, and the left and right ends are pivotally attached to the respective rear ends. Arm 37C.

  Forks 38 and 39 that are bifurcated in the vertical direction are provided at the front portions of the first and second arms 37A and 37B so as to extend toward the front of the vehicle body. The forks 38 and 39 are swingably fitted to a pair of left and right sleeves 40 and 41 slidably fitted to the left and right drive shafts 31 and 32 so as to sandwich the housing 14. Similar to the sleeves 40 and 41, the outer end portions of the cylindrical pistons 42 and 43 slidably fitted to the drive shafts 31 and 32 are detachably joined to the housing facing surface side of the sleeves 40 and 41. ing. These pistons 42 and 43 are extended so that the inner ends thereof reach the inside of the differential case 14 and the inner ends thereof are expanded in diameter. The inner end of the piston 42 and 43 is prevented from coming off from the differential case 14 by releasably joining to the side end surface inside the differential case 14. Between the inner ends of the pistons 42 and 43 and the multi-plate clutches 18 and 19, annular pressure plates 44 and 45 are disposed. In addition, a weight 46 having a preset weight is detachably fixed at a substantially central position of the third arm 37C that is symmetrical.

  The link mechanism 37 swings outward in the turning direction by a weight 46 that receives the lateral G generated during cornering, and the fork 38 on the outer side in the turning direction connected to the link mechanism 37 causes the piston 42 to differentially move through the sleeve 40. Press toward the inside of the case 14. The pressed piston 42 presses the multi-plate clutch 18 through the pressure plate 44. When the left and right multi-plate clutches 18 and 19 are pressure-bonded, driving torque is transmitted from the differential case 14 to the left and right differential bevel gears 22 and 23 via the left and right multi-plate clutches 18 and 19. Thus, the swinging motion of the link mechanism 37 acts as a pressing load for crimping the multi-plate clutches 18 and 19, and the multi-plate clutches 18 and 19 are engaged in proportion to the operation amount of the link mechanism 37, that is, the lateral G. Increase power. When the multi-plate clutches 18 and 19 rub against each other and stop moving, the left and right drive wheels are locked.

  In this way, the lateral G-sensitive mechanical differential limiting mechanism 12 improves the turning performance by not limiting the differential at the corner inlet where the lateral G is not applied, and is particularly large like the corner outlet. In a state where a lateral G is applied and a large driving force is required to escape the corner quickly, the differential restriction is ensured to ensure the traction of the left and right driving wheels, and the driving force is applied to the road surface. It is comprised so that turning performance may be improved by transmitting effectively.

  When the torque-sensitive mechanical differential limiting mechanism 11 and the lateral G-sensitive mechanical differential limiting mechanism 12 are simultaneously operated, the differential limiting force, that is, the crimping force of the multi-plate clutches 18 and 19 is applied. The operation with the stronger differential is given priority, and the operation of the differential limiting mechanism with the stronger differential limiting force is not hindered.

  The crimping force 18, 19 of the multi-plate clutch can be adjusted by appropriately changing the length and shape of the first, second and third arms 37A to 37C, the weight of the weight 46, and the like. The crimping characteristics can be easily changed. For example, it is possible to increase the crimping force even when the lateral G is small, or to weaken the crimping force even when the lateral G is large.

  Further, the weight 27 is not limited to the structure attached to the third arm 37C. For example, as shown in FIG. 3, the weights of the weights 27 are the same at the rear ends of the first and second arms 37A and 37B, respectively. It is also possible to adopt a structure in which the weights 47 and 48 are attached.

  Furthermore, the change of the link mechanism 37 does not apply only to the differential device 24 such as a front differential and a rear differential that transmits engine torque to the left and right drive wheels, but transmits the drive force from the engine to the front and rear drive wheels. It can also be applied to the center differential. When the present invention is applied to the center differential, electronic control using a lateral G sensor or the like is not performed, so that the unnaturalness that tends to be in electronic control is not felt, and the operation response is improved. Torque distribution to the front and rear wheels becomes more accurate and accurate, and all drive wheels can always exhibit optimum traction.

  As described above, according to the present invention, when the lateral G is generated during cornering, the lateral G-sensitive mechanical differential limiting mechanism 12 of the differential limiting device 10 operates outward in the turning direction according to the lateral G. The link mechanism 37 that engages the multi-plate clutches 18 and 19 transmits the driving torque to the left and right or front and rear driving wheels. The torque-sensitive mechanical differential limiting mechanism 11 of the differential limiting device 10 rotates with a differential case 14 that is rotationally driven by the engine driving force when one of the left, right, or front and rear driving wheels idles. The cross-shaped pinion shaft 20 pushes the pair of left and right pressure rings 16 and 17 to fasten the multi-plate clutches 18 and 19, thereby reducing the driving torque of the idling driving wheel and reducing the idling driving wheel. Increase drive torque. Thereby, the traction of all the driving wheels at the time of escape from the corner can be secured, the turning performance can be further improved, and the escape performance at the time of stacking and the stability at the time of straight running can be secured. In addition, since any of the differential limiting mechanisms 11 and 12 is mechanically operated, the operation response can be improved as compared with the conventional electronic differential limiting mechanism, and the vehicle structure is simplified. can do. In addition, since electronic components that require high component costs are not used, manufacturing costs can be reduced, operation is reliable, and reliability can be improved.

  Further, according to the present invention, the link mechanism 37 projects from the housing 13 housing the multi-plate clutches 18 and 19 toward the rear of the vehicle body, and is attached to a position where the link mechanism 37 is substantially symmetrical. 46 or 47, 48 is detachably attached. Then, the link mechanism 37 is engaged with the multi-plate clutches 18 and 19 for limiting the differential between the left and right or front and rear driving wheels by swinging outward in the turning direction according to the added lateral G. Let As a result, when the overhang amount of the link mechanism 37 and the weight of the weights 46 or 47, 48 are changed, the amount of movement toward the outside in the turning direction when the lateral G is applied changes, so the multi-plate clutches 18, 19 are The fastening force to be fastened can be easily adjusted.

It is sectional drawing of the differential gear device with which the differential limiting device concerning this embodiment was equipped. It is the schematic diagram which showed the meshing state of the pinion shaft and pressure ring in the example. It is sectional drawing of the differential limiting apparatus provided with the link mechanism from which the form differs.

Explanation of symbols

10 Differential Limiting Device 11 Torque-sensitive Mechanical Differential Limiting Mechanism 12 Lateral G-sensitive Mechanical Differential Limiting Mechanism 13 Housing 14 Differential Case 15 Ring Gears 16 and 17 Pressure Rings 18 and 19 Multi-plate Clutch 20 Cross Pinion Shaft (drive force transmission member)
21 differential bevel pinions 23, 24 differential bevel gears 31, 32 drive shaft 37 link mechanism 37A first arm 37B second arm 37C third arm 38, 39 fork 40, 41 sleeve 42, 43 piston 44, 45 pressure plate 46 , 47, 48 Weight

Claims (3)

A differential limiting device incorporated in a differential device between drive wheels of a vehicle,
When the lateral G is generated, the link mechanism that swings outward in the turning direction by the weight receiving the lateral G causes the swing motion to act as a pressing load, so that the differential between the left and right or front and rear drive wheels can be obtained. A differential limiting device comprising a lateral G-sensitive mechanical differential limiting mechanism for engaging a multi-plate clutch for limiting and transmitting driving torque to the left and right or front and rear driving wheels. When one of the left and right or front and rear drive wheels idles, the driving force transmission member that rotates together with the differential case that is driven to rotate by the engine driving force pushes the pair of left and right pressure rings to engage the multi-plate clutch. Te, along with reducing the driving torque of the driving wheel being idling, characterized by comprising a torque-sensitive mechanical differential limiting mechanism unit for increasing the driving torque of the driving wheel that is not slipping
Limited slip differential according to 請 Motomeko 1. The link mechanism is
A pair of left and right first and second arms projecting rearward from the housing housing the multi-plate clutch so as to be rotatable outward in the turning direction;
A third arm that connects the rear end of the first arm and the second arm, and has left and right ends rotatably attached to the respective rear ends,
It characterized in that the weight is removably attached to a substantially symmetrical position of the linkage
Limited slip differential according to 請 Motomeko 1 or claim 2.

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