JPH0732252U - Differential limiting ball cam device - Google Patents

Abstract

(57) [Abstract] [Purpose] Prevents the generation of differential limiting torque due to dragging due to the viscosity of the lubricating oil in the multi-plate clutch when the pilot clutch is not operating (when the electromagnet is not excited). Provided is a ball cam device for differential limiting, which has a wide control range of differential limiting and does not wear a clutch plate. [Configuration] Drag generated between multiple plates due to differential between left and right driving wheels when the pilot clutch is not operated Depending on the torque, for example, the cam ring 1 that receives the cam ball 2 and the pressing force may be prevented in order to prevent the cam ball 2 from being displaced so that relative rotation does not occur between the cam ring 1 and the pressing cam ring 3 in the differential limiting ball cam device. Second cams 6 and 7 for locking the cam ball 2 are further formed on the facing cam surfaces 4 and 5 of the cam ring 3, respectively.

Description

[Detailed description of the device]

[0001]

[Industrial applications]

 The present invention is a differential limiting device, in particular, a differential limiting device that performs differential limiting between driving wheels by engaging a friction multi-plate clutch. The cam ring that generates relative rotation with the pressing cam ring moves the pressing cam ring in the axial direction via the cam ball to join the multi-plate clutch in the main clutch to generate the differential limiting force. The present invention relates to a ball cam device.

[0002]

[Prior art]

 Conventionally, for example, the one provided with an electromagnet type differential limiting clutch that performs a differential limiting action by pressing a multi-plate clutch with a cam device is disclosed in Japanese Patent Laid-Open No. 5-141487. In this type, the rotation of a differential case, which has an internal gear that receives the driving force from the engine by a ring gear made of a bevel gear, is provided on the inner circumference, and the rotation of the differential gear constitutes a differential device consisting of the internal gear and the planetary gear unit. The drive force is transmitted to the left and right drive wheels via the pinion gear and sun gear, and the pinion revolves in response to the running resistance of the left and right drive wheels to absorb the rotational difference between the left and right drive wheels. The output from the planetary carrier is transmitted to the right drive wheel, and the output from the sun gear is transmitted to the left drive wheel. The differential limitation in this type of differential device is to limit and control the differential between the planetary carrier and the sun gear by joining friction type multi-plate clutches. The differential limitation causes the cam ring rotating due to the joining of the multi-plate clutch to rotate relative to the pressing cam ring when the pilot clutch is activated by the excitation of an appropriate electromagnet, and the pressing cam ring is axially moved through the cam ball. It is carried out by a differential limiting ball cam device which is moved to the left to join the multi-plate clutch in the main clutch to generate a differential limiting force.

In such a pilot clutch in the electromagnet type differential limiting device including the differential limiting ball cam device, the plate clutch and the cam ring side, which rotate together with the differential case side and are slidable in the axial direction, rotate. A multi-plate clutch is constructed by alternately arranging plates that are slidable in the axial direction together with each other, and lubricating oil, etc. is constantly filled between these plates. Therefore, due to the viscosity of the lubricating oil, the differential rotation between the left and right drive wheels is performed even when the differential limiting control is not performed, that is, when the pilot clutch is not operated (when the electromagnet is not excited). If the difference in number becomes large, the plate that rotates with the cam ring side may be dragged (drag) with respect to the plate that rotates with the differential case side, and drag torque may be generated. there were . 5 shows a cross section parallel to the axis of the differential limiting ball cam device composed of the cam ring 1, the cam ball 2 and the pressing cam ring 3 due to the generation of the drag torque, which corresponds to a cross section AA in FIG. 2 described later. ), The cam ring 1 starts to rotate and relative rotation occurs between the cam ring 1 and the pressing cam ring 3. As a result, a thrust force (differential force) that presses the pressing cam ring 3 in the axial direction via the cam ball 2 is generated. (Limiting force) was generated and the multi-plate clutch in the main clutch was joined. As a result, the plate of the main clutch is constantly exposed to the risk of wear, which may shorten the life of the device. Further, the control width of the differential limiting control when the pilot clutch is activated (when the electromagnet is excited) is also narrowed by the drag torque.

[0004]

[Problems to be solved by the device]

 Therefore, in the present invention, it is possible to prevent the generation of the differential limiting torque due to the drag (drag) when the pilot clutch is not in operation (when the electromagnet is not excited), which is seen in the above-described conventional differential limiting ball cam device. However, the present invention provides a differential limiting ball cam device in which the differential limiting control width is large and the clutch plate is not worn.

[0005]

[Means for Solving the Problems]

 Therefore, in the present invention, as a means for solving the above-described conventional problems, a differential limiting device for limiting the differential between the left and right driving wheels by joining friction type multi-plate clutches, and operating the pilot clutch At times, the cam ring that rotates due to the engagement of the multi-disc clutch generates relative rotation with the pressure cam ring, and the pressure cam ring is moved in the axial direction via the cam ball to engage the multi-disc clutch in the main clutch and move it. In the differential limiting ball cam device that generates the limiting force, the drag torque generated between the multiple plates due to the differential between the left and right driving wheels when the pilot clutch is not operated is different from that in the differential limiting ball cam device. It is characterized in that the cam ball is configured so as to prevent delusion of the cam ball so that relative rotation does not occur between the cam ring and the pressing cam ring. Than it is. Then, in order to prevent the cam ball from deviating, a second cam for locking a cam ball may be further engraved on each of the facing cam surfaces of the cam ring that receives the cam ball and the pressing cam ring. However, projections for locking the cam balls may be provided in front of and behind the cam balls on the opposing cam surfaces of the cam ring that receives the cam ball and the pressing cam ring. Further, depending on the drag torque, a spring having a spring constant that is not displaced by the drag torque is provided between the cam ring and the pressing cam ring so that relative rotation is generated between the cam ring and the pressing cam ring and the cam ball is not deviated. You may make it extend. Further, the differential limiting ball cam device is used not only for the above-mentioned differential limiting between the left and right driving wheels but also for the differential limiting device for performing the differential limiting between the front and rear driving wheels by joining the friction type multi-plate clutch. Of course you can.

[0006]

[Action]

 According to the present invention, depending on the drag torque generated between the multiple plates due to the viscosity of the lubricating oil due to the differential between the left and right drive wheels when the pilot clutch is not operating, the cam ring in the differential limiting ball cam device is In order to prevent relative rotation between the pressing cam rings, a cam ring for receiving the cam ball and a second cam for locking the cam ball are further engraved on each of the opposing cam surfaces of the pressing cam ring, or the cam ring for receiving the cam ball. Protrusions are provided in front of and behind the respective cam balls on the opposing cam surfaces of the pressing cam ring, or depending on the drag torque, relative rotation occurs between the cam ring and the pressing cam ring, causing the cam ball to slip. The cam ring and the pressure cam ring so that Since the cam ball is prevented from deviating by tensioning a spring having a spring constant that does not displace with lag torque, when the pilot clutch is not operating, the rotational speed between the left and right drive wheels can be changed by differential operation. Even if the difference becomes large and drag torque is generated between the multiple plates in the pilot clutch, the above-mentioned second cam for cam ball locking, the projection for cam ball locking, or the above-mentioned cam ring and the above-mentioned pressing cam ring The presence of a spring having a spring constant that does not displace with the drag torque does not change the positional relationship between the cam ring, the cam ball, and the pressing cam ring, so that relative rotation between the cam ring and the pressing cam ring in the differential limiting ball cam device is performed. It is possible to effectively prevent the occurrence of Since the differential limiting torque that generates the thrust force that presses the pressure cam ring in the axial direction is not generated, the multi-plate clutch in the main clutch is not joined, and the plate body of the main clutch is not worn. Not exposed to danger. Therefore, the life of the device can be extended, and the control width of the differential limiting control is not limited by the drag torque, so that the control width is correspondingly increased.

[0007]

【Example】

 An embodiment of the present invention will be described below with reference to the drawings. First, FIG. 2 shows a general view of a pinion type differential device to which the ball cam device for limiting a differential of the present invention is applied, and this will be described. The driving force from the engine is received from the input shaft 20 by the ring gear 21 formed of a bevel gear, and the rotation of the differential case 22 to which the ring gear 21 is fixed is transmitted to the pinion shaft 23 and the pinion 24 pivotally supported by the pinion shaft 23. This is differentially transmitted through a pinion type differential device composed of a pair of left side gear 25 and right side gear 27, which are bevel gears that mesh from both sides, to the left and right drive wheels via the left and right drive shafts. The driving force is distributed. The left side gear 25 has the left drive shaft spline-fitted to the inner diameter side, and the right side gear 27 has the right drive shaft spline-fitted to the inner diameter side. Since the left and right drive resistances are usually equal when going straight, the pinion 24 does not rotate, but transmits the rotation from the differential case 22 to the left and right drive shafts as it is. On the other hand, since the rotational speeds of the left and right drive wheels are different during steering, the pinion 24 is in rotational engagement with the inner side gear during steering, and the outer side gear during steering is the pinion 24. The driving force is increased by an amount corresponding to the rotation peripheral speed, and the driving force is differentially distributed to the left and right sides by the public rotation of each pinion 24 according to the difference in driving resistance between the two wheels. A vehicle equipped with such a differential device encounters a so-called split μ road in which the friction coefficient with the road surface is different between the left and right drive wheels, or the drive wheel with low road surface resistance is mischievous due to removal of one of the drive wheels. In the case of idling, the electromagnet type differential limiting clutch 15 is activated.

The electromagnet type differential limiting clutch 15 is configured as follows. Between the differential case 22 and the left side gear 25, a plate body that is rotatable with the side of the differential case 22 and is slidable in the axial direction and a plate body that is rotatable with the side of the left side gear 25 and is slidable in the axial direction. A main clutch 17 composed of multiple plates in which plates and plates are alternately arranged is arranged, and between the differential case 22 and the cam ring 1 on the extension shaft portion of the left side gear 25 is arranged on the side of the main clutch 17. Is a multi-plate in which a plate body that is rotatable together with the differential case 22 side and is slidable in the axial direction and a plate body that is rotatable together with the cam ring 1 and are axially slid in the axial direction are alternately arranged. A pilot clutch 16 that is configured of the above and operates by excitation of the electromagnet 19 is arranged. Between the pilot clutch 16 and the main clutch 17, there is arranged a ball cam device in which the cam ring 1 and the pressing cam ring 3 face each other with the cam ball 2 interposed therebetween.

Therefore, when differential limiting is required, when the armature 18 is attracted by the excitation of the electromagnet 19, the pilot clutch 16 is pressed and fastened, and the cam ring 1 is connected to the differential case 22 side via the pilot clutch 16. It On the other hand, since the cam ring 1 is related to the pressing cam ring 3 side by the ball cam device with the interposition of the cam ball 2, the cam ring 1 is relatively rotated between the cam ring 1 and the pressing cam ring 3 according to the engaging force (sliding) of the pilot clutch 16. As a result, the thrust force (differential limiting force) in the axial direction is generated by the action of the ball cam device, and the differential torque can be quickly generated by pressing the pressing cam ring 3 against the main clutch 17. The pinion 24 revolves in response to the engagement force of the main clutch 17, and the differential between the pinion 24 and the left and right side gears 25, 27 is limited and rotates with respect to the differential case 22 that constitutes the pinion type differential device. . When the engagement force of the pilot clutch 16 is maximized, the differential limiting force is also maximized, and the differential case 22, the pinion 24, and the left and right side gears, that is, the left and right drive shafts rotate as a whole, and a so-called differential lock state is established.

The differential limiting ball cam device according to the first embodiment of the present invention shown in FIG. 1 is applied to the electromagnet type differential limiting device as described above. FIG. 1 is an enlarged view of the AA cross section in FIG. When the differential limiting control is not performed due to the viscosity of the lubricating oil between the plates of the pilot clutch 16 composed of a multi-plate clutch, that is, when the pilot clutch 16 is not operating (when the electromagnet is not excited). ) Nevertheless, when the difference in the number of differential rotations between the left and right drive wheels becomes large, the plate that rotates together with the cam ring 1 side becomes “inherited” with respect to the plate that rotates together with the differential case 22 side. "Drag (dragging)", drag torque is generated, the cam ring 1 starts rotating, and relative rotation occurs between the pressing cam ring 3 and, as a result, through the cam ball 2. As described in the description of the conventional example, a thrust force that presses the pressing cam ring 3 in the axial direction may be generated to join the multi-plate clutch in the main clutch 17. A. However, in the first embodiment of the present invention, as is clear from FIG. 1, when the pilot clutch 16 is not operated, the drag torque generated between the multiple plates due to the differential between the left and right drive wheels causes The cam ring 1 and the pressing cam ring 3 that receive the cam ball 2 are opposed to each other in order to prevent the cam ball 2 from being moved so that relative rotation does not occur between the cam ring 1 and the pressing cam ring 3 in the differential limiting ball cam device. It is characterized in that groove-shaped second cam surfaces 6 and 7 for locking the cam balls are further formed on each of the cam surfaces 4 and 5 formed of a spherical surface or the like. The groove-shaped second cam surfaces 6 and 7 are formed at a steeper angle than the angle formed by the circumferential surfaces of the cam surfaces 4 and 5, and for example, when the maximum drag torque is 2 kg · m, the 2 kg · With a drag torque of m, the cam ball 2 is configured so as not to slip out of the second cam surfaces 6 and 7. Therefore, when the electromagnet type differential limiting device is inactive, the cam ring 1, the cam ball 2 and the pressing cam ring are not actuated. Since the positional relationship between the pressing cam ring 3 and the pressing cam ring 3 does not change, it is possible to effectively prevent relative rotation between the cam ring 1 and the pressing cam ring 3 in the differential limiting ball cam device. Since a thrust force that presses the shaft in the axial direction is not generated, it is not necessary to join the multi-plate clutch in the main clutch 17, Never plate of clutch 17 is exposed to the risk of wear. Therefore, the life of the device can be extended and the control width of the differential limiting control is not limited by the drag torque, so that the control width is correspondingly increased. Next, when the electromagnet 19 is excited to operate the pilot clutch 16 in order to perform the differential limiting control, it is possible to rotate the cam ring by generating a sufficient differential limiting torque due to the engagement of the multi-plate clutch. Therefore, the cam ball 2 can be easily removed from the groove-shaped second cams 6 and 7 of the cam ring 1 and the pressing cam ring 3 to cause relative rotation between the cam ring 1 and the pressing cam ring 3. The pressing cam ring 3 can be moved in the axial direction via the cam ball 2 to join the multi-plate clutch in the main clutch 17 to generate a sufficient differential limiting force.

Next, a second embodiment of the present invention will be described. FIG. 3 is an enlarged view of the AA cross section of FIG. 2, and prevents delusion of the cam ball 2 so that relative rotation does not occur between the cam ring 1 and the pressing cam ring 3 in the differential limiting ball cam device. For this purpose, projections 8, 8 and 9, 9 for locking the cam ball 2 are provided in front of and behind the respective cam balls 2 of the cam ring 1 for receiving the cam ball 2 and the opposing cam surfaces 4, 5 of the pressing cam ring 3. It is characterized by what has been done. With this configuration, as in the case of the first embodiment described above, when the electromagnet 19 of the pilot clutch 16 in the electromagnet type differential limiting device is inactive, the cam ball 2 causes the cam ring 2 and the pressing cam ring to operate depending on the drag torque. It is not possible to get over the projections 8, 8 and 9, 9 for locking the cam ball 2 that are provided on the cam surfaces 4, 5 of No. 3, and the positional relationship between the cam ring 1, the cam ball 2 and the pressing cam ring 3 does not change. Therefore, it is possible to effectively prevent relative rotation between the cam ring 1 and the pressing cam ring 3 in the differential limiting ball cam device. Therefore, the thrust force that presses the pressing cam ring 3 in the axial direction via the cam ball 2 is applied. Since it is not generated, the multi-plate clutch in the main clutch 17 is not joined.

Further, a third embodiment of the present invention will be described. FIG. 4 is an enlarged view of a cross section taken along the line AA in FIG. 2, and prevents the cam ball 2 from being deviated so that relative rotation does not occur between the cam ring 1 and the pressing cam ring 3 in the differential limiting ball cam device. For this purpose, a spring having a spring constant that does not displace with the drag torque is stretched between the cam ring 1 and the pressing cam ring 3. Specifically, the cam ring 1 is provided with a concave portion 10, and the pressing cam ring 3 is provided with a convex portion 11 corresponding to the concave portion 10 of the cam ring 1 and accommodated in the concave portion 10. The concave portion 10 and the convex portion 11 are provided. The springs 12 and 13 having a spring constant that does not displace with drag torque are stretched between the side walls in the direction of rotation. With this configuration, as in the first and second embodiments described above, when the electromagnet 19 of the pilot clutch 16 in the electromagnet type differential limiting device is inactive, the cam ring 1, the cam ball 2, and the pressing force may be increased depending on the drag torque. Since the positional relationship between the cam rings 3 does not change, it is possible to effectively prevent relative rotation between the cam ring 1 and the pressing cam ring 3 in the differential limiting ball cam device, and therefore the pressing cam ring 3 via the cam ball 2 described above. Since no thrust force that presses the shaft in the axial direction is generated, the multi-plate clutch in the main clutch 17 is not joined.

The above-described differential limiting ball cam device has been shown in the embodiment adopted in the friction type multi-disc clutch in the differential limiting device between the left and right drive wheels. Needless to say, it can be applied to a differential limiting device for limiting the differential between the front and rear driving wheels, that is, a center differential. Further, although the differential limiting ball cam device of the present invention has been described as an example applied to a pinion type differential device, it can also be applied to an appropriate differential device such as a planetary type differential device. Of course.

[0014]

[Effect of device]

 As described above in detail, according to the present invention, when the pilot clutch is not operated, the drag torque generated between the multiple plates of the pilot clutch due to the viscosity of the lubricating oil due to the differential between the left and right drive wheels Since the cam ball in the differential limiting ball cam device is prevented from relative rotation between the cam ring and the pressing cam ring to prevent delusion of the cam ball, the differential rotation between the left and right drive wheels is performed. Even if drag torque is generated between the multiple plates in the pilot clutch due to a large difference in the numbers, the positional relationship between the cam ring, the cam ball, and the pressing cam ring does not change.Therefore, between the cam ring and the pressing cam ring in the differential limiting ball cam device. Can be effectively prevented from causing relative rotation, and therefore when the pilot clutch is not operating. Since the thrust force that presses the pressing cam ring in the axial direction through the cam ball is not generated and the differential limiting force is not generated, the multi-plate clutch in the main clutch is not joined, and the plate of the main clutch is not joined. Your body is not at risk of wear. Therefore, the life of the device can be extended, and the control width of the differential limiting control is not limited by the drag torque, so that the control width is correspondingly increased.

[Brief description of drawings]

FIG. 1 is a diagram showing a first embodiment of a differential limiting ball cam device of the present invention.

FIG. 2 is an overall view of a pinion type differential device to which the differential limiting ball cam device of the present invention is applied.

FIG. 3 is a view showing a second embodiment of the differential limiting ball cam device of the present invention.

FIG. 4 is a view showing a third embodiment of the differential limiting ball cam device of the present invention.

FIG. 5 is a diagram showing an example of a conventional differential limiting ball cam device.

[Explanation of symbols]

 DESCRIPTION OF SYMBOLS 1 cam ring 2 cam ball 3 pressing cam ring 4 cam surface 5 cam surface 6 second cam surface 7 second cam surface 8 protrusion 9 protrusion 10 recess 11 protrusion 12 spring 13 spring 15 electromagnet type differential limiting clutch 16 pilot clutch 17 main clutch 18 Armature 19 Electromagnet 20 Input shaft 21 Ring gear 22 Differential case 23 Pinion shaft 24 Pinion 25 Left side gear 27 Right side gear

Claims (5)

[Scope of utility model registration request] 1. A differential limiting device for limiting the differential between right and left driving wheels by joining friction type multi-plate clutches, wherein a cam ring that rotates by joining the multi-plate clutch when a pilot clutch is actuated is a pressing cam ring. In the differential limiting ball cam device that generates relative rotation between the two, the pressing cam ring is axially moved via the cam ball to join the multi-plate clutch in the main clutch to generate the differential limiting force, The cam ball is prevented from deviating so that relative rotation does not occur between the cam ring and the pressing cam ring in the differential limiting ball cam device due to drag torque generated between the multiple plates due to the differential between the left and right drive wheels when not operating. A ball cam device for differential limitation, which is configured as described above. 2. Relative rotation occurs between the cam ring and the pressing cam ring in the differential limiting ball cam device depending on the drag torque generated between the multiple plates due to the differential between the left and right driving wheels when the pilot clutch is not operated. In order to prevent the cam ball from deviating so that it does not occur, a second cam for locking the cam ball is further formed on each of the facing cam surfaces of the cam ring that receives the cam ball and the pressing cam ring. Item 1. A ball cam device for limiting a differential according to Item 1. 3. Relative rotation occurs between the cam ring and the pressing cam ring in the differential limiting ball cam device depending on the drag torque generated between the multiple plates due to the differential between the left and right drive wheels when the pilot clutch is not operated. In order to prevent the cam ball from deviating so that it does not occur, projections for locking the cam ball are provided in front of and behind the respective cam balls of the cam surfaces that receive the cam ball and the cam surface of the pressing cam ring that face each other. The ball cam device for limiting a differential according to claim 1. 4. Relative rotation occurs between the cam ring and the pressing cam ring in the differential limiting ball cam device depending on the drag torque generated between the multiple plates due to the differential between the left and right drive wheels when the pilot clutch is not operated. 2. The ball cam for differential limitation according to claim 1, wherein a spring having a spring constant that does not displace with the drag torque is stretched between the cam ring and the pressing cam ring so as to prevent the cam ball from deviating. apparatus. 5. The differential limiting ball cam device according to claim 1, wherein the differential limiting device for limiting the differential between the front and rear drive wheels is performed by joining friction type multi-plate clutches.