JPH0536158U - Defarency device - Google Patents

Abstract

(57) [Abstract] [Purpose] When the first friction clutch is engaged, differential torque acts on the cam to engage the second friction clutch, and the engagement force of these clutches limits the differential. An object of the present invention is to provide a differential device in which the differential limiting force is stable, the differential limiting force does not remain when the differential is free, and the number of parts is small. According to a differential device of the present invention, a differential mechanism, first and second friction clutches arranged between the differential members, an electromagnet for opening and closing the first friction clutch, and a first friction clutch. A cam that receives the differential torque when the clutch is engaged and that engages the second friction clutch.
The friction clutch is characterized by having a pair of clutch members each having a friction surface.

Description

[Detailed description of the device]

[0001]

[Industrial applications]

 The present invention relates to a differential device used in a vehicle.

[0002]

[Prior Art]

 Japanese Unexamined Patent Publication (Kokai) No. 63-195449 discloses a "slip limited differential gear assembly". This is a differential device that limits the differential with an electromagnetic multi-plate clutch, and a cam is used to supplement the fastening force of the multi-plate clutch by the electromagnet.

[0003]

[Problems to be solved by the device]

 The electromagnetic clutch used in in-vehicle equipment cannot use a large electromagnet, and a large fastening force cannot be obtained. Generally, the friction plate of the multi-plate clutch has slits in the radial direction, and the transmission torque varies depending on the contact state of the slits of the outer friction plate and the inner friction plate. Further, even if the multi-plate clutch is released, drag torque is generated due to the warp of the friction plates. As described above, when the tightening force (transmission torque) is relatively weak, such variations in torque and drag torque have a great influence. In addition, the multi-plate clutch has a large number of parts due to the use of many friction plates.

Therefore, an object of the present invention is to provide a differential device having an electromagnetic clutch for limiting a differential, which has a small number of parts and does not generate a variation in torque or a drag torque.

[0005]

[Means for Solving Problems]

 The differential device of the present invention comprises a differential mechanism, first and second friction clutches arranged between the differential members, an electromagnet for opening and closing the first friction clutch, and a first friction clutch. And a cam that receives the differential torque to close the second friction clutch, and the first friction clutch has a pair of clutch members each having a friction surface.

[0006]

[Action]

 When the first friction clutch is engaged, a differential torque is applied to the cam, the generated cam force engages the second friction clutch, and the engagement force of both friction clutches limits the differential rotation of the differential mechanism. The first friction clutch is configured such that a pair of clutch members (for example, a cone portion of a cone clutch) are pressed against each other and fastened, and no friction plate is used. Therefore, the variation of the transmission torque and the drag torque due to the slits and warpage of the friction plate are not generated, and the number of parts is significantly reduced.

[0007]

【Example】

 One embodiment will be described with reference to FIGS. FIG. 1 shows a differential device of this embodiment, and FIG. 3 shows a power system of a vehicle using this device. Hereinafter, the left and right directions are the left and right directions in this vehicle and FIGS. 1 and 2, and the upper side in FIG. 1 corresponds to the front side (upper side in FIG. 3) of this vehicle. Further, members and the like not given reference numerals are not shown.

First, the configuration of this power system will be described with reference to FIG.

The power system includes an engine 1, a transmission 3, a propeller shaft 5, a rear differential 7 (a differential device of FIG. 1 arranged on the rear wheel side), rear axles 9, 11, left and right rear wheels 13, 15, left and right. The front wheels 17 and 19 are included.

Next, the rear differential 7 will be described.

As shown in FIG. 3, the differential case 21 (differential member) is rotatably supported in the differential carrier 23. A ring gear 25 is fixed to the differential case 21, and the ring gear 25 meshes with a drive pinion gear 27. The drive pinion gear 27 is integrally formed at the rear end of the drive pinion shaft 29 connected to the propeller shaft 5 side. In this way, the rotation of the engine 1 rotationally drives the differential case 21 from the transmission 3 via the propeller shaft 5.

As shown in FIG. 1, left and right hubs 31 and 33 are coaxially arranged inside the differential case 21, and the left hub 31 is spline-connected to the left rear axle 9 and the right hub 33. Is splined to the right rear axle 11.

Further, inside the differential case 21, a planetary gear type differential mechanism 35 is arranged. The differential mechanism 35 includes an internal gear 37, an outer pinion gear 39, an inner pinion gear 41, and a sun gear 43 (differential member) that are meshed in order.

The pinion gears 39 and 41 are rotatably supported on the respective pinion shafts 45 and 47, and both ends of the pinion shafts 45 and 47 are supported by left and right pinion carriers 49 and 51 (differential members). . The internal gear 37 is formed on the inner peripheral surface of the differential case 21, and the sun gear 43 is formed on the right hub 33. The left and right pinion carriers 49 and 51 are welded and integrated. The right pinion carrier 51 is formed integrally with the right hub 33.

In this way, the differential mechanism 35 is configured, and the rotation of the differential case 21 (internal gear 37) is performed by the sun gear 43 (hub 31) and the pinion carriers 49, 51 (hub 33) via the pinion gears 39, 41. And is transmitted to the left and right rear wheels 13 and 15 side, and when a drive resistance difference occurs between the rear wheels, the pinion gears 39 and 41 are differentially distributed to the left and right sides by rotation and revolution.

On the left side of the differential mechanism 35, a multi-plate type main clutch (second friction clutch) that connects the left pinion carrier 49 and the left hub 31 is arranged. A shim 55 is arranged between the main clutch 53 and the left pinion carrier 49.

A cam ring 57 (clutch member) is arranged on the right side of the pinion carrier 51. As shown in FIG. 2, a cam 61 is formed between the pinion carrier 51 and the cam ring 57 via a ball 59. An armature 63 (clutch member) is arranged on the outer side of the cam 61, and the outer periphery of the armature 63 is spline-coupled to the inner periphery of the differential case 21 so as to be axially movable. A retaining ring 64 for restricting the position of the armature 63 is attached to the differential case 21 on the left side of the armature 63. Conical friction surfaces 65 and 67 are formed on the armature 63 and the cam ring 57, respectively, to form a cone clutch type pilot clutch (first friction clutch) 69.

A ring-shaped electromagnet 73 is arranged outside the right boss portion 71 of the differential case 21. The electromagnet 73 is supported by the boss portion 71 via bearings 75 and 75, and is fixed to the differential carrier 23 via a supporting member. Air gaps 81 and 83, which are part of the magnetic circuit, are provided between the yoke 77 of the electromagnet 73 and the right side wall 79 of the differential case 21, and the right side wall 79 is guided to the armature 63 while preventing a magnetic short circuit. The non-magnetic ring 85 is welded.

When the electromagnet 73 attracts the armature 63, the pilot clutch 69 is engaged. In this way, when the cam ring 57 is connected to the differential case 21 via the pilot clutch 69, the differential torque generated between the differential case 21 and the pinion carrier 51 is applied to the cam 61, and the left side shown in FIG. The thrust force 87 causes the main clutch 53 to be pressed and engaged via the pinion carriers 49 and 51. The right thrust force 89 is input to the differential case 21 via the bearing 91 and the washer 93.

The electromagnet 73 is automatically operated according to the road surface condition and the steering condition of the vehicle, and the differential force of the differential mechanism 35 is limited by the engaging force between the pilot clutch 69 and the main clutch 53. As described above, since the engagement force of the pilot clutch 69 is amplified by the cam 61 to engage the main clutch 53, a large differential limiting force can be obtained even if the engagement force of the pilot clutch 69 is relatively weak.

When the slip of the pilot clutch 69 is adjusted by the electromagnet 73, the engaging force of the main clutch 53 is changed by the change of the slatting force of the cam 61, and the differential limiting force can be controlled. If the engaging force of each clutch 53, 69 is moderately relaxed, the differential rotation between the rear wheels 13, 15 is allowed, and if the engaging force is sufficiently increased, the differential rotation is locked. When the pilot clutch 69 is released, the thrust force of the cam 61 disappears, the main clutch 53 is also released, and the differential rotation becomes free.

Unlike the conventional example, the pilot 69, which is greatly affected by the variation of the fastening force and the drag torque due to the fact that it is operated by the electromagnet 73 and its fastening force is amplified by the cam 61, uses a friction plate. Since it is a type that does not have a tightening force, drag torque does not occur. Further, even if the main clutch 53 is a multi-plate type, the cam 61 is engaged with a large amplified force, so that the influence of the torque variation and the drag torque is small.

Therefore, the differential limiting force is stable, and the differential limiting force does not remain when it is desired to free the differential. Since the pilot clutch 69 does not use a friction plate and the cam ring 57 and the armature 63 also serve as clutch members, the number of parts is extremely small and the structure is simple. For the above reason, a multi-plate type can be used for the second friction clutch. In this way, the rear differential 7 is configured.

In the vehicle shown in FIG. 3, even if one of the rear wheels 13 and 15 runs idle on a rough road or the like, the driving force is sent to the other wheel by the differential limiting force of the rear differential 7, so that the vehicle can be easily driven on a rough road. To be kept. If this differential limiting force is strengthened, the differential rotation between the rear wheels is greatly limited to improve straight running stability, and if the differential limiting force is moderately relaxed, smooth and stable turning can be performed. Since the limiting force is stable and there is no differential limiting force remaining when the differential is free, the steerability and stability of the vehicle are improved.

The first friction clutch is not limited to the cone clutch as in the embodiment, and the friction surface may be perpendicular to the pressing direction. When the first friction clutch is a cone clutch, the characteristics can be changed by changing the friction surface angle.

[0026]

[Effect of the device]

 The differential device of this invention does not use a friction plate for the first friction clutch which is operated by an electromagnet and whose engaging force is increased by a cam, so that the differential limiting force is stable and the differential limiting force is set when the differential is free. The force does not remain and the number of parts is small.

[Brief description of drawings]

FIG. 1 is a sectional view of an embodiment.

FIG. 2 is a sectional view taken along line AA of FIG.

FIG. 3 is a skeleton mechanism diagram showing a power system of a vehicle using this embodiment.

[Explanation of symbols]

 21 differential case (differential member) 35 differential mechanism 43 sun gear (differential member) 49, 51 pinion carrier (differential member) 53 main clutch (second friction clutch) 57 cam ring (clutch member) 61 cam 63 armature (clutch Member) 65, 67 Friction surface 69 Pilot clutch (first friction clutch) 73 Electromagnet

Claims (1)

[Scope of utility model registration request] 1. A differential mechanism, first and second friction clutches arranged between the differential members, an electromagnet for opening and closing the first friction clutch, and a first friction clutch are engaged. And a cam that receives the differential torque and engages the second friction clutch, and the first friction clutch has a pair of clutch members each having a friction surface.