JPH0635680U - Electromagnetic clutch - Google Patents

Abstract

(57) [Summary] [Purpose] To reduce the magnetic flux leakage from the spline joint. A clutch outer and a clutch inner arranged to be rotatable relative to each other, and a friction clutch having a plurality of clutch plates disposed between the clutch outer and the clutch inner and alternately spline-coupled to the clutch outer and the clutch inner, In an electromagnetic clutch having an electromagnet for engaging the friction clutch by attracting an attraction member arranged with the clutch plate of the friction clutch separated, at least one of the clutch outer side and the clutch inner side spline coupling portion, The toothless portion 65P in which some of the spline-coupled teeth are cut out is formed, and a non-engaged portion is positively created to reduce the magnetic flux leakage from the tooth surface of the spline.

Description

[Detailed description of the device]

[0001]

[Industrial applications]

 The present invention relates to an electromagnetic clutch.

[0002]

[Prior art]

 FIG. 7 shows a differential device equipped with a conventional electromagnetic clutch described in Japanese Utility Model Laid-Open No. 3-68634, and FIG. 10 shows a power system of a vehicle equipped with this differential device.

First, the power system will be described.

This power system includes an engine 1, a transmission 3, a propeller shaft 7, a rear differential 9 (a differential device equipped with an electromagnetic clutch, which is a problem here), rear axles 11 and 13, left and right rear wheels 15 and 17. , The left and right front wheels 19, 21 and the like.

As shown in FIG. 7, the differential case 23 of the rear differential 9 is supported by bearings 25 and 27 in a differential carrier 29. A ring gear 31 is fixed to the differential case 23 with bolts 33. The drive pinion shaft 35 is supported in the differential carrier 29 by bearings 37 and 39, the front end is connected to the propeller shaft 7 side, and the drive pinion gear 41 is formed at the rear end. The pinion gear 41 meshes with the ring gear 31. In this way, the differential case 23 is rotationally driven by the driving force from the engine 1.

Inside the differential case 23, a pair of relatively rotatable bosses 43 and 45 are coaxially arranged on the left and right, and the left boss 43 is integrated with the planet carrier 47. An internal gear 49 is formed on the inner circumference of the differential case 23, and a sun gear 51 is formed on the right boss 45.

On the planet carrier 47, an outer planet gear 55 is rotatably supported by a shaft 53, and an inner planet gear is rotatably supported by another shaft. These planetary gears mesh with each other, the outer planetary gear 55 meshes with the internal gear 49, and the inner planetary gear meshes with the sun gear 51. Thus, the planetary gear differential mechanism 57 is configured.

The left boss 43 is spline-coupled to the left rear axle 11 so as to be axially movable, and the right boss 45 is spline-coupled to the right rear axle 13.

Therefore, the driving force from the engine 1 is split and output from the differential case 23 to the left and right rear wheels 15 and 17 via the differential mechanism 57, and is differentially split to each side by the rotation and revolution of the planetary gears. To be done.

A clutch drum 59 is fixed to the right end of the planet carrier 47. A multi-plate clutch 61 is arranged between the drum 59 and the right boss 45 to connect them. The drum 59 is movable left and right, and when it is moved rightward, the multi-plate clutch 61 is pressed and engaged with the right side wall 63 of the differential case 23. When the multi-plate clutch 61 is engaged, the differential of the differential mechanism 57 is limited according to the magnitude of the engaging force.

On the other hand, a clutch ring 65 is arranged on the outer periphery of the left boss 43 so as to be rotatable relative to each other, and the clutch ring (clutch inner) 65 and the differential case (clutch outer) 23 are connected to each other. A multi-plate friction clutch 67 is arranged. As shown in FIG. 9, this friction clutch 67 has a clutch plate 67A whose inner periphery is spline-engaged on the clutch ring 65 side and a clutch plate 67B whose outer periphery is spline-engaged on the differential case 23 side. It is composed.

A cam mechanism 71 that operates via balls 69 is formed between the clutch ring 65 and the planet carrier 47, as shown in FIG. The cam mechanism 71 includes a cam 65A integrally formed on the side of the clutch ring 65 and another cam 47A integrally formed on the side of the planet carrier 47A. It is a costume.

According to this cam mechanism 71, when the clutch ring 65 rotates relative to the planet carrier 47 (moves in the direction of arrow A in the figure) from the position shown, the planet carrier 47 moves to the right via the ball 69. Is pushed to. Therefore, when the friction clutch 67 is engaged, the above-mentioned pushing movement force (thrust force) is generated in the cam mechanism 71 by the differential torque between the left rear wheel 15 and the differential case 23, which causes the boss 43 and the planet carrier 47. The drum 59 moves to the right, and the multi-plate clutch 61 is engaged. In this way, the fastening force of the friction clutch 67 adjusts the fastening force of the multi-plate clutch 61, and the fastening force of the multi-plate clutch 61 largely limits or locks the differential of the differential mechanism 57.

Further, a needle bearing 73 for receiving the reaction force of the cam mechanism 71 is arranged between the clutch ring 65 and the differential case 23.

A suction member 75 made of a magnetic material is arranged on the right side of the friction clutch 67 so as to be movable in the left and right directions. A ring-shaped electromagnet 79 is arranged on the outer periphery of the left boss 77 of the differential case 23, and is supported by the boss 77 by bearings 81 and 81. The friction clutch 67, the electromagnet 79, and the attraction member 75 constitute an electromagnetic clutch 100, which is a problem here.

The electromagnetic clutch 100 drives and controls the multi-plate clutch 61, which is the main clutch, and thus can be called a pilot clutch.

Then, when the coil of the electromagnet 79 of the electromagnetic clutch 100 is energized, a line of magnetic force is formed as indicated by an arrow B 1, the suction member 75 is attracted, and the friction clutch 67 is engaged.

Next, the function of the rear differential 9 will be described with reference to FIG. 10 in accordance with the power performance of the vehicle.

The driving force of the engine 1 is decelerated by the transmission 3, is transmitted to the rear differential 9 via the propeller shaft 7, and is split and output to the left and right rear wheels 15 and 17.

When the electromagnetic clutch 100 and the multi-plate clutch 61 are in the released state, the differential between the rear wheels 15 and 17 is free, smooth turning is possible, and straight traveling on the uneven portion is possible. Stability is maintained.

When the electromagnetic clutch 100 is engaged and the multi-plate clutch 61 is engaged, the differential between the rear wheels 15 and 17 is limited. Therefore, even if one of the rear wheels becomes idling on a bad road or the like, the driving force sent to the other via the rear differential 9 improves the running performance, and the vehicle can maintain smooth running.

[0022]

[Problems to be solved by the device]

 By the way, in the conventional electromagnetic clutch 100, as shown in FIG. 9, the magnetic flux leakage from the spline coupling portions S1 and S2 of the clutch plates 67A and 67B was large, so that a large engaging force could not be obtained. Therefore, when it is applied as a pilot clutch of a differential device, it is impossible to increase the engaging force on the multi-disc clutch 61 side and there is a problem that the differential limiting torque cannot be increased.

In particular, since the clutch ring 65 side is used as a cam, it is easily magnetized due to the relationship of being repeatedly subjected to a compressive load, and therefore the magnetic flux leakage (indicated by Ba in the figure) from the spline coupling portion S1 on the clutch ring 65 side is remarkable. There is a problem in that the size of the electromagnetic clutch 100 becomes large and the performance of the electromagnetic clutch 100 is likely to deteriorate.

In order to suppress magnetic flux leakage from the spline coupling portion S2 on the side of the differential case 23, as shown in FIG. 9, the spline 23a of the differential case 23 is separately formed of stainless steel, which is a non-magnetic material. There is also a structure in which it is welded to the main body side, but there is a problem that the welded portion P becomes weak in strength because the diameter is particularly large on the side of the differential case 23 as the clutch outer.

In view of the above circumstances, the present invention provides an electromagnetic clutch that has no strength problem and that reduces magnetic flux leakage as much as possible, thereby increasing the engagement force of the friction clutch. To aim.

[0026]

[Means for Solving the Problems]

 The present invention is a friction clutch having a clutch outer and a clutch inner that are rotatably disposed relative to each other, and a plurality of clutch plates that are disposed between the clutch outer and the clutch inner and that are alternately splined to the clutch outer and the clutch inner. And an electromagnet for engaging the friction clutch by attracting a suction member arranged with the clutch plate of the friction clutch interposed therebetween, in the spline coupling portion on the clutch outer side and the clutch inner side. It is characterized in that a toothless portion is formed by cutting out a part of the mutual spline-joint teeth on at least one of the two.

According to the second aspect of the present invention, the clutch outer and the clutch inner are arranged so as to be rotatable relative to each other, and the plurality of clutch outers and the clutch inner are arranged between the clutch outer and the clutch inner and are alternately spline-coupled to the clutch outer and the clutch inner. The clutch inner has a cam surface, and an electromagnet for engaging the friction member by attracting suction members arranged with the clutch plate of the friction clutch interposed therebetween. In an electromagnetic clutch that is configured as a cam that axially displaces a member that contacts the cam surface by rotating, the spline on the clutch inner side of the clutch inner and the spline coupling part of the clutch plate is composed of a magnetic flux blocking material. It is characterized by that.

[0028]

[Action]

 In the conventional electromagnetic clutch, all the teeth mesh with each other both at the spline joint between the clutch plate and the clutch outer and at the spline joint between the clutch plate and the clutch inner. Therefore, the contact area of the tooth surface was extremely large, and the magnetic flux easily leaked through the tooth surface that contacted them.

In the electromagnetic clutch of the present invention, a part of the teeth of the spline coupling portion is cut out to form a toothless portion.

As a result, the contact area between the teeth at the spline coupling portion becomes small, the gap at the spline coupling portion becomes large, the magnetic flux leakage decreases, and the engaging force of the friction clutch increases. Further, the presence of the toothless portion improves the passage of the lubricating oil and improves the lubricity.

Further, particularly when a toothless portion is provided in the spline coupling portion on the clutch outer side to reduce magnetic flux leakage, it is not necessary to form the spline on the clutch outer side with a nonmagnetic material. The main body side and spline can be integrated with a magnetic material, and weakened parts in terms of strength can be eliminated.

Further, in the invention of claim 2, since the spline of the spline coupling portion on the clutch inner side, which repeatedly receives a compressive load as the cam, is made of a magnetic flux blocking material, it is particularly effective in reducing magnetic flux leakage.

[0033]

【Example】

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

All the electromagnetic clutches mentioned here as examples are those applied to the differential device 9 shown in FIG. 7, and refer to FIG. 7 or FIG. 9 for the overall configuration.

FIG. 1 is a sectional view of a main part of an electromagnetic clutch according to a first embodiment of the present invention.

In the electromagnetic clutch of this embodiment, the clutch ring (cam) 65 as the clutch inner and the clutch plate 67A are spline-coupled (spline coupling portion is indicated by S1) as shown in FIG.

That is, in the past, all the teeth of the spline were meshed with each other, but in the present embodiment, the teeth on the side of the clutch ring 65 are partially cut away to form a toothless portion 65P, so that there is no positive meshing. I made the part I did. The toothless portion 65P is of course formed with the teeth necessary for strength remaining, and is formed at equal intervals in the circumferential direction in consideration of balance.

Since the toothless portion 65P remains as a void, this portion blocks the magnetic flux. Further, since the tooth engagement rate is reduced, the contact area of the tooth surface is reduced and the magnetic flux leakage is reduced. Therefore, the engaging force of the electromagnetic clutch increases.

FIG. 2 is a sectional view of the main part of the electromagnetic clutch of the second embodiment of the present invention.

In the first embodiment, the tooth of the spline on the clutch ring 65 side is cut out to form the toothless portion 65P. However, in the electromagnetic clutch of the second embodiment, the tooth of the spline on the clutch plate 67A side is toothless. The part 67P was formed. In this case as well, the toothless portions 67P are naturally formed with the teeth necessary for strength remaining, and are formed at equal intervals in the circumferential direction in consideration of balance.

The first embodiment and the second embodiment may be combined to provide a toothless portion on both the clutch ring 65 and the clutch plate 67A.

FIG. 3 is a sectional view of a main part of an electromagnetic clutch according to a third embodiment of the present invention.

In the first and second embodiments, the case where the toothless portion is formed in the spline of the spline coupling portion S1 between the clutch plate 67A and the clutch ring 65 has been described, but the electromagnetic clutch of the third embodiment is described. Then, the toothless portion 67P 'is formed on the spline tooth of the spline connecting portion S2 between the clutch plate 67B and the differential case 23 as the clutch outer. Of course, conversely, a toothless portion may be formed on the spline on the side of the differential case 23.

As described above, when the spline coupling portion S2 between the clutch plate 67B and the differential case 23 is provided with the toothless portion to reduce the magnetic flux leakage, the spline is not made of a non-magnetic material as in the conventional case. Can also obtain the same fastening force. Therefore, as shown in FIG. 4, the spline can be integrated with the differential case 23 to eliminate weak points in strength. In this case, it is desirable that the diff case 23 is made of cast metal and only the spline portion is induction hardened, or the diff case 23 is made of a high carbon material such as a carburized and hardened material having high magnetic flux blocking performance.

FIG. 5 is a sectional view of a main part of an electromagnetic clutch according to a fourth embodiment of the present invention.

In the electromagnetic clutch of the fourth embodiment, the spline 167 of the clutch ring 165 used as a cam is separately formed of a non-magnetic material (flux blocking material) and is joined to the main body 166 side by welding (welding point Q). is doing. In this case, the spline material itself prevents flux leakage.

Further, FIG. 6 shows an example in which the spline 267 of the clutch ring 265 is separately formed of a non-magnetic material, and is connected to the main body 266 by a spline 268 as a connecting means other than welding.

The first to fourth embodiments may be combined as appropriate to form one electromagnetic clutch.

[0049]

[Effect of device]

 As described above, according to the present invention, it is possible to reduce the magnetic flux leakage from the spline coupling portion of the clutch plate, thereby increasing the engaging force of the friction clutch. In addition, especially when a toothless part is provided in the spline of the spline joint on the clutch outer side to reduce magnetic flux leakage, the spline does not have to be made of a non-magnetic material. It is also possible to increase the strength. Also, since the toothless portion functions as a lubrication path, the lubricity is also good.

Further, in the case where the clutch inner side member is configured as a cam and the spline on the clutch inner side is made of the magnetic flux blocking material, the magnetic flux leakage is significantly reduced, and the fastening force is increased. Can be achieved.

[Brief description of drawings]

FIG. 1 is a cross-sectional view of a main part of a first embodiment of the present invention.

FIG. 2 is a cross-sectional view of a main part of a second embodiment of the present invention.

FIG. 3 is a cross-sectional view of a main part of a third embodiment of the present invention.

FIG. 4 is a side sectional view of a main portion of a third embodiment of the present invention.

FIG. 5 is a side sectional view of a main portion of a fourth embodiment of the present invention.

FIG. 6 is a side sectional view of a main part of a fifth embodiment of the present invention.

FIG. 7 is a sectional view of a vehicle differential device 9 using a conventional electromagnetic clutch 100.

8 is a view taken along the line VIII-VIII in FIG.

9 is an electromagnetic clutch 1 of the differential device 9. FIG.
It is a side sectional view showing details around 00.

FIG. 10 is a skeleton diagram of a power system of a vehicle using the differential device 9.

[Explanation of symbols]

 23 differential case (clutch outer) 65 clutch ring (clutch inner) 67 friction clutch 67A, 67B clutch plate 75 suction member 79 electromagnet 100 electromagnetic clutch 65P, 67P, 67P 'toothless portion 167,267 spline S1, S2 spline coupling portion

Claims (2)

[Scope of utility model registration request] 1. A friction clutch having a clutch outer and a clutch inner arranged to be rotatable relative to each other, and a plurality of clutch plates disposed between the clutch outer and the clutch inner and alternately splined to the clutch outer and the clutch inner. And an electromagnet for attracting a suction member arranged to separate the clutch plate of the friction clutch to fasten the friction clutch, at least one of the clutch outer side and the clutch inner side spline coupling portions. On the other hand, an electromagnetic clutch is characterized in that a toothless portion is formed by cutting out a part of the mutually splined teeth. 2. A friction clutch having a clutch outer and a clutch inner arranged to be rotatable relative to each other, and a plurality of clutch plates disposed between the clutch outer and the clutch inner and alternately splined to the clutch outer and the clutch inner. And an electromagnet that engages the friction clutch by attracting a suction member arranged with the clutch plate of the friction clutch interposed therebetween, wherein the clutch inner is
In an electromagnetic clutch configured as a cam that has a cam surface and axially displaces a member in contact with the cam surface by rotating itself, a magnetic flux is generated on a clutch inner side spline of a spline coupling portion between the clutch inner and the clutch plate. An electromagnetic clutch characterized by being made of a blocking material.