JPH04366037A - Electromagnetic clutch - Google Patents

Abstract

PURPOSE:To provide an electromagnetic clutch having the narrow axial width in which a main clutch is engaged by a cam force generated through an electromagnet operated pilot clutch. CONSTITUTION:An electromagnetic clutch is characteristically provided with a friction type pilot clutch 87 and main clutch 57, a ring-like electromagnet 95 for operating the pilot clutch 87 and a cam 81 for engaging the main clutch 57 by a cam force generated on the cam receiving torque when the pilot clutch 87 is engaged, wherein the pilot clutch 87 is disposed inside the electromagnet 95.

Description

[Detailed description of the invention]

0001

BACKGROUND OF THE INVENTION 1. Field of the Invention This invention relates to an electromagnetic clutch.

0002

2. Description of the Related Art Japanese Patent Laid-Open Nos. 63-192620 and 1988-195449 disclose a differential device that uses an electromagnetic clutch to limit differential movement.

The former has a main clutch for differential limiting, a differential mechanism, a pilot clutch that generates the engagement force of the main clutch, an electromagnet for operating the pilot clutch, etc. arranged in series, and the latter also has a differential mechanism, a differential mechanism, and an electromagnet for operating the pilot clutch. clutch,
Electromagnets are arranged in series.

0004

As described above, in both devices, since the electromagnet is arranged in series with the clutch, the width becomes wider in the axial direction. Therefore, for example, a differential device cannot be housed in a differential carrier with narrow bearing spacing, making it difficult to use it in small cars and the like.

[0005] Accordingly, an object of the present invention is to provide an electromagnetic clutch having a narrow axial width.

[0006]

[Means for Solving the Problems] The electromagnetic clutch of the present invention includes a friction type pilot clutch and a main clutch, a ring-shaped electromagnet for operating the pilot clutch, and a ring-shaped electromagnet for operating the pilot clutch.
It is characterized in that it is equipped with a cam that engages the main clutch by a cam force generated in response to torque when the pilot clutch is engaged, and that the pilot clutch is disposed inside the electromagnet.

[0007]

[Operation] When the pilot clutch is engaged by an electromagnet, torque is applied to the cam and cam force is generated.The main clutch is engaged by this cam force, and the electromagnetic clutch becomes connected. When the engagement force of the pilot clutch is adjusted by adjusting the magnetic force of the electromagnet, the engagement force of the main clutch changes due to a change in the cam force, and the transmission torque can be adjusted. When the pilot clutch is released, the main clutch is also released, and the electromagnetic clutch becomes disengaged.

Since the pilot clutch has a small diameter and is placed inside the electromagnet, it is possible to reduce the overall axial width by the width of this clutch, which saves space when used alone or in combination with related mechanisms. It will be advantageous.

[0009]

[Embodiment] A first embodiment will be explained with reference to FIGS. 1 to 3.

FIG. 1 shows a differential device using this embodiment, and FIG. 3 shows a power system of a vehicle using this differential device. Hereinafter, the left and right directions are the left and right directions in this vehicle and in FIGS. 1 and 2, and the upper part of FIG. 1 corresponds to the front of this vehicle (the upper part of FIG. 3).

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

This power system includes an engine 1, a transmission 3, a propeller shaft 5, a rear differential 7 (the differential device shown in FIG. 1 used on the rear wheel side), and rear axles 9 and 11.
, left and right rear wheels 13, 15, left and right front wheels 17, 19, etc.

Next, the rear differential 7 will be explained.

A differential case 21 of the rear differential 7 is supported within a differential carrier 23 via bearings, as shown in FIG. A ring gear 25 is fixed to the differential case 21, and the ring gear 25 is connected to a drive pinion gear 29 formed at the rear end of the drive pinion shaft 27.
It meshes with the.

Therefore, the driving force of the engine 1 rotates the differential case 21 from the transmission 3 via the propeller shaft 5.

Inside the differential case 21 are left and right hubs 31.
, 33 are rotatably arranged. The left hub 31 is splined to the left rear axle 9, and the right hub 33 to the right rear axle 11.

A planetary gear type differential mechanism 35 is disposed within the differential case 21. The differential mechanism 35 includes an internal gear 37, an outer pinion gear 39, an inner pinion gear 41, and a sun gear 43 that mesh in this order.

The internal gear 37 is formed on the differential case 21, and the sun gear 43 is formed on the left hub 31. The outer and inner pinion gears 39, 41 are rotatably supported on respective pinion shafts 45, 47. Each pinion shaft 45, 47 is supported by left and right pinion carriers 49, 51 with both ends crimped. Each carrier 49, 51 is welded together, with the right carrier 51 being integrally formed with the right hub 33. Washers 53, 53 are arranged between each pinion gear 39, 41 and pinion carrier 49, 51.

In this way, the differential mechanism 35 is constructed, and the rotation of the differential case 21 (internal gear 37) is controlled by the sun gear 43 (hub 31) via the pinion gears 39, 41.
) and pinion carriers 49, 51 (hub 33), and the transmission is transmitted to the left and right rear wheels 13, 15 via the hubs 31, 33. Due to rotation and revolution, it is differentially distributed to the left and right sides.

A multi-disc main clutch 57 is disposed on the left side of the differential mechanism 35 and connects the cylindrical portion 55 of the left pinion carrier 49 and the left hub 31. A washer 6 is installed between the differential case 21, the left side wall 59, and the clutch 57.
1 is arranged, and a shim 63 is arranged between the carrier 49 and the clutch 57.

An opening 65 is provided in the left side wall 59 and the washer 61.
, 67 are provided, and oil sealed in the differential carrier 23 flows in and out from these openings 65 and 67 to lubricate the interior of the differential case 21. In addition, the washer 61
The claw 69 is folded into an opening 65 in the left side wall 59 to prevent rotation.

A hub 71 is located on the right side of the pinion carrier 51.
is located. The hub 71 is rotatably supported on a cylindrical portion 72 provided in the differential case 21 and the outer peripheral portion of the right hub 33. The cam ring 7 is attached to the left end of the hub 71.
3 is integrally formed with an armature 75 at the left end.
are integrally formed. A retaining ring 77 is provided on the inner periphery of the differential case 21 to prevent contact between the armature 75 and the carrier 51.
is installed.

As shown in FIG. 2, the pinion carrier 51
A cam 8 is connected via a ball 79 between the cam ring 73 and the cam ring 73.
1 is formed.

A cylindrical portion 85 having a smaller diameter than the cylindrical portion 83 is formed on the right end side of the differential case 21 . This cylindrical part 85
A multi-disc pilot clutch 87 is disposed between the hub 71 and the hub 71 to connect them. This clutch 87
A bearing 89 and a pressing member 91 are arranged between the cam ring 73 and the cam ring 73 from the left.

A ring-shaped electromagnet 95 is arranged coaxially with the cylindrical portion 85 on the right side of the right side wall 93 that connects the cylindrical portions 83 and 85 of the differential case 21 . This electromagnet 95 consists of an electromagnetic coil 97 and a yoke 99, and is supported by the cylindrical portion 85 via a needle bearing 101, and is connected to the differential carrier 23 via a rotation preventing member 103. A non-magnetic ring 105 is embedded in the right side wall 93 in order to prevent the magnetic flux of the electromagnet 95 from short-circuiting and guide it to the armature 75.

When the electromagnet 95 attracts the armature 75 through the magnetic circuit 107, the pilot clutch 87 is pressed against the differential case 21 through the cam ring 73, the bearing 89, and the pressing member 91, and is engaged.

When the pilot clutch 87 is engaged,
The hub 71 is connected to the differential case 21 via a clutch 87. Further, since the hub 71 is connected to the pinion carrier 51 via the cam ring 73 and the cam 81, the differential rotation between the internal gear 37 and the pinion gears 39 and 41 is caused by the engagement force (slip) of the clutch 87. The brake is applied, and the differential movement of the differential mechanism 35 is limited.

When the clutch 87 is engaged, the differential torque of the differential mechanism 35 acts on the cam 81, producing left and right cam forces 109 and 111, as shown in FIG.

The pinion carriers 49 and 51 move to the left due to the left cam force 109, and the main clutch 57 is moved between the carrier 49 (shim 63) and the differential case 21 (washer 61).
Press and tighten between the two. In this way, the pilot clutch 87 serves as a switch mechanism for the main clutch 57.

The right cam force 111 is generated by the cam ring 73, the bearing 89, the pressing member 91, and the pilot clutch 87.
is input to the differential case 21 via the left cam force 109, and is offset by the left cam force 109. Also, in this way, the pilot clutch 87
The fastening force is increased.

As described above, the differential limiting force of the differential mechanism 35 is strengthened by the engagement force of the pilot clutch 87 and the main clutch 57.

The electromagnet 95 causes the pilot clutch 8 to
When the engagement force (slip) of 7 is adjusted, the engagement force of the main clutch 57 changes due to a change in the cam force 109, and the differential limiting force can be controlled.

When the engagement force of each clutch 57, 87 is sufficiently large, the differential is locked, and when the engagement force is moderately relaxed, the differential is allowed. When the pilot clutch 87 is released, the cam forces 109 and 111 disappear, and the main clutch 57 is also released.

[0034] Such differential limiting force control is performed manually from the driver's seat, or automatically according to road surface conditions, vehicle steering conditions, and the like.

[0035] In this way, the rear differential 7 is constructed.

Pilot clutch 8 that performs the switch mechanism
7 does not require a large torque capacity.

Therefore, as described above, the pilot clutch 87 can be configured to have a small diameter and placed inside the electromagnet 95. By doing this, the axial width of the rear differential 7 is reduced by the clutch 87.
can be narrowed by the width of In this way, a differential device with sufficient differential limiting force can be housed in a differential carrier for a small car, expanding the range of applicable vehicle types.

In the vehicle shown in FIG. 3, the rear wheels 13
, 15 is in a idling state, if the differential of the rear differential 7 is limited, the driving force sent to the other rear wheel via the rear differential 7 maintains running performance. Increasing the differential limiting force of the rear differential 7 limits the differential between the rear wheels and improving the straight-line stability of the vehicle, while weakening the differential limiting force allows smooth turning.

Next, the second embodiment will be explained with reference to FIG.

In this embodiment, the electromagnetic clutch of the present invention is used alone as a power transmission device 113. Hereinafter, the left and right directions are the left and right directions in FIG.

The input member 115 is rotatably disposed within a casing 117, which is an output member, and is rotationally driven by a torque input through a spline-connected hollow shaft 119. A retaining ring 121 is attached to the hollow shaft 119.

[0042] The left end side of the casing 117 has a small diameter portion 12.
3 is formed. Further, inside the casing 117, a cam ring 125, an armature 127, and a pressing member 129 are arranged from the left.

A bearing 131 is arranged between the casing 117 and the cam ring 125. The armature 127 is spline connected to the inner circumference of the casing 117 so as to be movable in the axial direction, and the pressing member 129 is spline connected to the input member 115 so as to be movable in the axial direction.

Inside the cylindrical portion 123, the cam ring 12
between the pilot clutch 13 and the armature 127
3 (cone clutch) is formed. Cam ring 1
A disc spring 135 is disposed between the armature 127 and the armature 127 to bias the armature 127 in the direction in which the pilot clutch 133 is released.

A cam 139 is formed between the cam ring 125 and the pressing member 129 with a ball 137 interposed therebetween.

[0046] A ring-shaped electromagnet 1 surrounds the cylindrical part 123.
41 are coaxially arranged and supported on the fixed side. A non-magnetic ring 145 is embedded in the left side wall 143 of the casing 117 in order to prevent the magnetic flux of the electromagnet 141 from short-circuiting and guide it to the armature 127.

The casing 11 is located to the right of the pressing member 129.
A multi-disc main clutch 147 connecting the input member 115 and the input member 115 is disposed.

When the armature 127 is attracted by the electromagnet 141 and the pilot clutch 133 is engaged, the cam ring 125 is connected to the casing 11 via the clutch 133.
7 side, torque is applied to the cam 139, and left and right cam forces 149 and 151 are generated. Rightward cam force 151
As a result, the main clutch 147 is pressed and engaged with the casing 117 via the pressing member 129, and the power transmission device 113 becomes connected. The left cam force 149 is input to the casing 117 via the bearing 131 and is offset by the right cam force 151.

Pilot clutch 1 is activated by electromagnet 141.
33 to adjust the torque acting on the cam 139, the change in the cam force 151 causes the main clutch 1
47 changes, and the transmission torque of the power transmission device 113 is controlled. When the engagement force of each clutch 133, 147 is sufficiently large, input member 115 and casing 117 are locked, and the transmitted torque is maximized. Electromagnet 141
When the current is cut off, the pilot clutch 133 is opened by the disk spring 135, and the main clutch 147 is also opened, and the power transmission device 113 is opened.

By reducing the diameter of the pilot clutch 113 and placing it inside the electromagnet 141, the clutch 133
The width of the power transmission device 113 can be reduced by the width of .

When the cone clutch is used as a switch function (pilot clutch) for the main clutch 147 in this way, it can be made more compact than a multi-disc clutch, and it has the effect of narrowing the width of the power transmission device 113 accordingly. big.

[0052]

[Effects of the Invention] This invention is an electromagnetic clutch in which the main clutch is engaged by cam force when the pilot clutch is engaged, and since the pilot clutch is placed inside the ring-shaped electromagnet that is the operating means, the entire width of the pilot clutch is reduced. The axial width can be reduced, which is advantageous in terms of space. Therefore, when used as a differential limiting device, for example, a differential device having sufficient differential limiting force can be downsized, and such a differential device can also be used in small cars.

[Brief explanation of drawings]

FIG. 1 is a sectional view of a differential device using a first embodiment.

FIG. 2 is a sectional view taken along line AA in FIG. 1;

3 is a skeleton mechanism diagram showing a power system of a vehicle using the differential device of FIG. 1. FIG.

FIG. 4 is a sectional view of the second embodiment.

[Explanation of symbols]

57, 147 Main clutch 81, 139 Cam 87, 133 Pilot clutch 95, 141 Electromagnet

Claims (1)

[Claims] [Claim 1] A friction-type pilot clutch and a main clutch, a ring-shaped electromagnet for operating the pilot clutch, and a cam that engages the main clutch by a cam force generated in response to torque when the pilot clutch is engaged. , an electromagnetic clutch characterized in that a pilot clutch is placed inside an electromagnet.