JP2002061677A - Driving force transmitting device - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide a driving force transmitting device capable of using a material improving the strength of an outer rotating member in comparison with a conventional one, and free from the failure in attracting an armature (failure in operation of armature) because no complex magnetic path is formed, and the failure in transmitting the driving force is not caused. SOLUTION: This driving force transmitting device comprises a friction clutch 34 mounted between a front housing 31a at the outside and an inner shaft 30b at the inside, made of only an iron material and coaxially and relatively rotatably positioned to each other, and the armature 35 operated in supplying the power to an electromagnet 33 for allowing the friction clutch 34 to be frictionally engaged. The armature 35 is made of an iron material, and the other side face not opposite to an outer clutch plate 34b is covered by aluminum A. As a result, the armature 35 can be correctly attracted to an electromagnet 33 side without being attracted to a second cam member 38 side made of the iron material.

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

The present invention relates to a driving force transmitting device, and more particularly to a driving force transmitting device having a friction clutch (electromagnetic clutch).

[0002]

2. Description of the Related Art A driving force transmission device proposed in Japanese Patent Application Laid-Open No. 11-153159 has been known.

[0003] The driving force transmission device includes an inner and outer rotating member coaxially and relatively rotatable with each other, a main clutch mechanism for transmitting torque between the rotating members by frictional engagement, and an energized operation. An electromagnetic pilot clutch mechanism that frictionally engages is provided. The driving force transmission device includes a cam mechanism between the main clutch mechanism and the pilot clutch mechanism, and the cam mechanism converts a frictional engagement force of the pilot clutch mechanism into a pressing force on the main clutch mechanism.

[0004] The pilot clutch mechanism includes a friction clutch disposed between the inner and outer rotating members, and an electromagnetic driving means that operates by energization to frictionally engage the friction clutch. The driving means includes an armature made of an iron material facing the friction clutch, and an electromagnet positioned outside the outer rotating member and facing the friction clutch with a side wall of the outer rotating member interposed therebetween.

The cam mechanism has a first cam member to which the frictional engagement force of the pilot clutch mechanism is transmitted, and a second cam member to which the frictional engagement force is transmitted from the first cam member and which presses the main clutch mechanism. And a cam member. The second cam member is located between the armature and the main clutch mechanism.

[0006] By energizing the electromagnetic coil of the electromagnet, a yoke supporting the electromagnet, a front side wall of the outer rotating member, a friction clutch, an armature, a friction clutch, a magnetic path circulating through the front side wall and the yoke are formed, The armature is attracted to the friction clutch by magnetic induction. As a result, the armature presses and frictionally engages the friction clutch, so that the cam mechanism operates the main clutch mechanism to connect the outer rotating member and the inner rotating member so that torque can be transmitted.

By the way, in the driving force transmission device having the above structure, since the pilot clutch is an electromagnetic clutch, measures are taken to prevent magnetic flux leakage in order to efficiently form the magnetic path. That is, for example, the entire housing, which is the outer rotating member, is formed of aluminum material, or stainless steel, which is a non-magnetic material corresponding to a portion where a magnetic path is partially formed, is made of iron, which is a magnetic material. To prevent magnetic flux leakage.

[0008]

By the way, in the driving force transmission device, there is a demand for increasing the strength of the entire housing in view of the mounting on the vehicle. In order to solve this problem, for example, it is conceivable that the entire housing is made of iron, which is a magnetic material, to increase the strength. But,
If the entire housing is made of iron, magnetic flux leaks from the portion where the magnetic path is formed, or the conventional simple magnetic path becomes a complicated magnetic path, causing an armature suction failure (armature operation failure), There is a possibility that the driving force transmission is poor.

Therefore, the present invention has been made in view of the above-mentioned circumstances, and an object of the present invention is to use a material which increases the strength of the outer rotating member as compared with the related art. An object of the present invention is to provide a driving force transmission device that does not form a complicated magnetic path when operated, does not cause armature suction failure (armature operation failure), and does not cause driving force transmission failure.

[0010]

In order to achieve the above object, the invention according to claim 1 comprises a friction clutch disposed between both inner and outer rotating members rotatably positioned relative to each other;
An electromagnetic drive unit that operates by energization to frictionally engage the friction clutch, the drive unit comprising: an armature located inside the outer rotating member and facing the friction clutch; An electromagnet is provided on the outer side and opposed to the friction clutch with a side wall of the outer rotating member interposed therebetween, and by energizing the electromagnet, the armature is attracted to frictionally engage the friction clutch, and the friction is applied. In a driving force transmission device in which the two rotating members can be connected to transmit torque by a frictional engagement force of a clutch, a side surface of the armature facing the friction clutch is formed of a magnetic material, and the armature is not opposed to the friction clutch. The gist is that the side surface of is covered with a non-magnetic material.

In the present specification, the magnetic material refers to an object having ferromagnetism, and the non-magnetic material refers to an object having paramagnetism. According to a second aspect of the present invention, in the first aspect, the entire outer rotating member is formed of a magnetic material.

According to a third aspect of the present invention, there is provided a main clutch mechanism for transmitting torque between the inner and outer rotating members by frictional engagement between the inner and outer rotating members, and an electromagnetic type which is frictionally engaged when operated by energization. A pilot clutch mechanism, and a cam mechanism that is located between the main clutch mechanism and the pilot clutch mechanism and converts a frictional engagement force of the pilot clutch mechanism into a pressing force on the main clutch mechanism. A friction clutch disposed between the inner and outer rotating members, and an electromagnetic drive unit that operates by energization to frictionally engage the friction clutch, wherein the drive unit includes an armature facing the friction clutch; A mechanism including an electromagnet positioned outside the outer rotating member and opposed to the friction clutch with a side wall of the outer rotating member interposed therebetween And, the friction clutch frictionally engage by suction the armature by energizing the same electromagnet,
In a driving force transmission device that brings the two rotating members into a connected state capable of transmitting torque by a frictional engagement force of the friction clutch,
A non-magnetic material is provided on at least the surface of the cam mechanism-side member facing the armature.

According to a fourth aspect of the present invention, in the third aspect, the member on the cam mechanism side facing the armature is entirely made of a non-magnetic material. According to a fifth aspect of the present invention, in the third or fourth aspect, the whole outer rotating member is formed of a magnetic material. (Operation) Therefore, according to the first aspect of the present invention, when the electromagnet is energized, a magnetic path circulating between the electromagnet, the friction clutch, the armature, the friction clutch and the electromagnet is formed. At this time, since the other side of the armature that is not opposed to the friction clutch is covered with a non-magnetic material, it is possible to prevent magnetic flux leakage from the armature to parts other than the friction clutch, and the armature is reliably attracted to the electromagnet side by magnetic induction. Is done. Then, the friction clutch is securely frictionally engaged, and torque transmission is reliably performed between the two rotating members.

According to the second aspect of the present invention, in addition to the function of the first aspect, the armature side prevents the leakage of magnetic flux between the armature and members other than the friction clutch.
Therefore, even if the outer rotating member is formed only of a magnetic material, the armature is reliably attracted to the electromagnet side by energizing the electromagnet.

According to the third aspect of the present invention, when electricity is supplied to the electromagnet, a magnetic path is formed between the electromagnet, the friction clutch, the armature, the friction clutch, and the electromagnet. At this time, a non-magnetic material is provided on at least the surface of the cam mechanism-side member facing the armature on the cam mechanism-side member facing the armature. for that reason,
There is no magnetic flux leakage from the armature to the member, and the armature is not attracted to the member side but is reliably attracted to the electromagnet side. Then, the friction clutch is securely frictionally engaged, and torque transmission is reliably performed between the two rotating members.

According to the fourth aspect of the present invention, the function of the third aspect is realized by forming the entire member on the cam mechanism side facing the armature from a non-magnetic material. According to the fifth aspect of the present invention, the armature is not sucked by the member on the cam mechanism side facing the armature by the operation of the third aspect. Therefore, even if the outer rotating member is formed only of a magnetic material, the armature is reliably attracted to the electromagnet side by energizing the electromagnet.

[0017]

(First Embodiment) A first embodiment of the present invention will be described below with reference to FIGS.

FIG. 1 shows a driving force transmission device according to a first embodiment of the present invention. As shown in FIG. 2, the driving force transmission device 11 is disposed on a driving force transmission path to a rear wheel of the four-wheel drive vehicle 12.

The four-wheel drive vehicle 12 includes a driving force transmitting device 1
1, a transaxle 13, an engine 14, a pair of front wheels 15, and a pair of rear wheels 16. The driving force of the engine 14 is output to the axle shaft 17 via the transaxle 13 to drive the front wheels 15.

A driving force transmission device 11 is connected to the transaxle 13 via a propeller shaft 18.
The driving force transmission device 11 includes a drive pinion shaft 1
9, a rear differential 20 is connected. The rear wheel 20 is connected to the rear differential 20 via an axle shaft 21. When the propeller shaft 18 and the drive pinion shaft 19 are connected by the driving force transmission device 11 so as to be able to transmit torque, the driving force of the engine 14 is transmitted to the rear wheels 16.

The driving force transmitting device 11 is accommodated in a differential carrier 22 together with a rear differential 20, is supported by the differential carrier 22, and is supported by the vehicle body via the differential carrier 22.

Next, the driving force transmission device 11 will be described. As shown in FIG. 1, the driving force transmission device 11 includes an outer case 30a, an inner shaft 30 as an inner rotating member.
b, a main clutch mechanism 30c, a pilot clutch mechanism 30d, and a cam mechanism 30e.

The outer case 30a has a bottomed cylindrical front housing 31a and a front housing 31a.
And a rear housing 31b screwed into the rear end opening and covering the opening. The front housing 31a corresponds to an outer rotating member, and the rear housing 31b corresponds to a side wall of the outer rotating member. An input shaft 50 protrudes from a front end of the front housing 31a, and the input shaft 50 is connected to the propeller shaft 1.
8.

The front housing 31a and the rear housing 31b integrally formed with the input shaft 50 are made of a magnetic material such as an iron material (eg, carbon steel S35C, S35C for machine structure).
10C). Rear housing 31
A stainless steel cylinder 51 which is a non-magnetic material is embedded in a radially intermediate portion of b, and the cylinder 51 forms an annular non-magnetic portion so that a magnetic path Z to be described later is formed. Has become.

The outer case 30a is rotatably supported on a differential carrier 22 (see FIG. 2) at the outer periphery of the front end of the front housing 31a via a bearing (not shown) or the like. The outer case 30a is supported by a yoke 36 supported by the differential carrier 22 (see FIG. 2) on the outer periphery of the rear housing 31b via a bearing or the like.

The inner shaft 30b is inserted into the front housing 31a through the center portion of the rear housing 31b in a liquid-tight manner, and is prevented from moving in the axial direction.
b is rotatably supported relative to b. The inner shaft 30b has a drive pinion shaft 19 (FIG. 2).
(See Reference). In FIG. 1, the drive pinion shaft 19 is not shown.

As shown in FIGS. 1 and 3, the main clutch mechanism 30c is a wet-type, multi-plate friction clutch mechanism having a plurality of inner clutch plates 32a and outer clutch plates 32b.
a is disposed on the back wall side.

Each inner clutch plate 32a constituting the friction clutch mechanism is spline-fitted to the outer periphery of the inner shaft 30b, and is assembled so as to be movable in the axial direction. On the other hand, each outer clutch plate 32b is spline-fitted to the inner periphery of the front housing 31a and is movably mounted in the axial direction. Each inner clutch plate 32a and each outer clutch plate 32b
Are alternately positioned and come into contact with each other to frictionally engage with each other, and are separated from each other to be in a non-engagement free state.

The pilot clutch mechanism 30d includes an electromagnet 33, a friction clutch 34, and an armature 35. The electromagnet 33 and the armature 35 constitute driving means.

As shown in FIG. 1, a yoke 3 made of an iron material
6 is axially supported on a differential carrier 22 (see FIG. 2), and a rear housing 31 is provided.
b is supported so as to be rotatable relative to the outer periphery of the rear end. An annular electromagnet 33 is fitted to the yoke 36, and the electromagnet 33 is connected to the annular recess 5 of the rear housing 31b.
3 is fitted. As a result, the rear housing 31b
A predetermined clearance is formed between the motor and the yoke 36.

The friction clutch 34 is configured as a multi-plate friction clutch including a plurality of inner clutch plates 34a made of an iron material and a plurality of outer clutch plates 34b made of an iron material. Each inner clutch plate 34a is spline-fitted to the outer periphery of a first cam member 37 constituting a cam mechanism 30e described later, and is assembled so as to be movable in the axial direction. On the other hand, each outer clutch plate 34b is spline-fitted to the inner periphery of the front housing 31a and is movably mounted in the axial direction.

The inner clutch plates 34a and the outer clutch plates 34b are alternately positioned, abut against each other and frictionally engage with each other, and are separated from each other to be in a non-engagement free state.

The armature 35 is formed in an annular shape, and is spline-fitted to the inner periphery of the front housing 31a so as to be movable in the axial direction. The armature 35 is located on one side with respect to the friction clutch 34 and faces the friction clutch 34.

As shown in FIG. 4, the armature 35 is formed of an iron material and has other sides that do not face the outer clutch plate 34b, that is, the side of the second cam member 38, the side of the outer case 30a (outer circumference), and the inner circumference. The side surface of each side is covered with aluminum A. Note that aluminum is a non-magnetic material.

As shown in FIG. 3, by energizing the electromagnetic coil of the electromagnet 33, the yoke 36, the rear housing 3
A magnetic path Z that circulates between the first clutch 1b, the friction clutch 34, the armature 35, the friction clutch 34, the rear housing 31b, and the yoke 36 is formed.

As shown in FIGS. 1 and 3, the cam mechanism 30e
Are the first cam member 37 and the second cam member 3 made of an iron material.
8 and a cam follower 39. The second cam member 38 corresponds to a member on the cam mechanism side facing the armature 35.

In the first cam member 37 and the second cam member 38, a plurality of cam grooves (not shown) facing each other are formed on the opposing surfaces at predetermined intervals in the circumferential direction. The first cam member 37 is rotatably fitted to the outer periphery of the inner shaft 30b, and is rotatably supported by the rear housing 31b. Each inner clutch plate 34a is spline-fitted to the outer periphery of the first cam member 37.

The second cam member 38 includes an inner shaft 30b.
Of the inner shaft 3
0b so as to be integrally rotatable. The second cam member 38 is located to face the inner clutch plate 32a of the main clutch mechanism 30c. A ball-shaped cam follower 39 is interposed between the opposed cam grooves of the second cam member 38 and the first cam member 37.

As a result, the armature 35 is located on one side of the friction clutch 34 inside the front housing 31a, and the electromagnet 33 is located on the other side of the friction clutch 34 outside the front housing 31a with the rear housing 31b interposed therebetween. And the rear housing 31b functions as a magnetic path forming member.

The rear housing 31b includes the inner shaft 3
0b in a liquid-tight and rotatably fitted state on the outer periphery of
The peripheral portion of the front wall portion is screwed to the front housing 31a. The rear housing 31b is connected to the differential carrier 22 (see FIG. 2) via an oil seal (not shown) on the outer periphery of the rear end of the rear cylinder.
Liquid-tightly and rotatably supported.

In the driving force transmission device 11 as described above, the electromagnet 3 constituting the pilot clutch mechanism 30d is used.
When power is not supplied to the third electromagnetic coil, the magnetic path Z is not formed, and the friction clutch 34 is in the non-engaged state. Therefore, the pilot clutch mechanism 30d is in a non-operating state, and the first cam member 37 constituting the cam mechanism 30e is connected to the second cam member 38 via the cam follower 39.
And the main clutch mechanism 30c is in a non-operating state. Thus, the four-wheel drive vehicle 12 constitutes a two-wheel drive mode.

On the other hand, when power is supplied to the electromagnetic coil of the electromagnet 33, a magnetic path Z is formed in the pilot clutch mechanism 30d, and the electromagnet 33 attracts the armature 35. For this reason, the armature 35 presses the friction clutch 34 to cause frictional engagement, connects the first cam member 37 of the cam mechanism 30e to the front housing 31a side, and causes relative rotation with the second cam member 38. . As a result, the cam mechanism 30
In e, the cam follower 39 presses the two cam members 37 and 38 away from each other.

As a result, the second cam member 38 is pressed toward the main clutch mechanism 30c, and
c is frictionally engaged in accordance with the frictional engagement force of the friction clutch 34 to transmit torque between the outer case 30a and the inner shaft 30b. Thus, the four-wheel drive vehicle 12 constitutes a four-wheel drive drive mode in which the propeller shaft 18 and the drive pinion shaft 19 are not directly connected.

When the current applied to the electromagnetic coil of the electromagnet 33 is increased to a predetermined value, the armature 35
To the suction force. Then, the armature 35 is strongly attracted to the electromagnet 33 side, increasing the frictional engagement force of the friction clutch 34 and increasing the relative rotation between the two cam members 37, 38. As a result, the cam follower 39 increases the pressing force on the second cam member 38 to bring the main clutch mechanism 30c into the connected state. For this reason, the four-wheel drive vehicle 12 includes a propeller shaft 18 and a drive pinion shaft 19.
Constitute a drive mode of four-wheel drive directly connected.

Next, the operation of the driving force transmission device 11 configured as in the first embodiment will be described. When the electromagnetic coil of the electromagnet 33 is energized, the magnetic path Z
Is formed, and the electromagnet 33 attracts the armature 35 by the magnetic induction action. At this time, the yoke 36, the rear housing 31b, the front housing 31a, the armature 35, the second cam member 3
8. A magnetic flux may pass through to the inner shaft 30b, the rear housing 31b, and the yoke 36. However, FIG.
As shown in FIG. 5, the other side of the armature 35 not facing the outer clutch plate 34b is covered with aluminum A, which is a non-magnetic material.

Therefore, even when the clearance between the armature 35 and the second cam member 38 is small, the armature 35, the front housing 31a, and the armature 3
No magnetic flux passes between 5 and the second cam member 38. Then, the yoke 36, the rear housing 31b, the front housing 31a, the armature 35, the second cam member 38,
A magnetic path that circulates through the inner shaft 30b, the rear housing 31b, and the yoke 36 is not formed. As a result, since the magnetic induction of the magnetic path via the second cam member 38 does not occur, the armature 35 is not attracted to the second cam member 38, and the armature 35 is a part of the pilot clutch mechanism 30d. Function normally.

In FIG. 5, the horizontal axis shows the current flowing through the electromagnetic coil of the electromagnet 33, and the vertical axis shows the torque (transmission torque) transmitted from the driving force transmission device 11 to the drive pinion shaft 19.

A curve CH indicates a driving force transmission device 1 of the present embodiment having an armature 35 covered with aluminum A.
1 is the curve drawn. On the other hand, the curve CZ shows the armature 3
5 is a curve drawn when the clearance between the armature 35 and the second cam member 38 is small in a driving force transmission device in which the front housing 5 and the front housing 31a are made of only an iron material, that is, the aluminum A is not provided in the armature 35. In the driving force transmitting device that draws the curve CZ, a magnetic path is formed via the second cam member 38, and the armature 35 is attracted to the second cam member 38, so that the pilot clutch mechanism 30d does not function sufficiently. It is shown that.

Accordingly, the driving force transmission device 11 of the present embodiment
Provides a stable current-torque characteristic that is more stable than the driving force transmission device that draws the curve CZ. Therefore, according to the driving force transmission device 11 of the first embodiment, the following effects can be obtained.

(1) In the driving force transmission device 11 of the present embodiment, the armature 35 is formed of an iron material, and the other side of the armature 35 that does not face the outer clutch plate 34b, that is, the second cam member 38 side, Outer case 3
The side surfaces of the 0a side (outer peripheral side) and the inner peripheral side were covered with aluminum A. And the front housing 31
a was formed only of an iron material.

For this reason, even if the electromagnet 33 is energized,
Since the other side except one side of the armature 35 is covered with aluminum A, the armature 35 and the front housing 31a, and the armature 35 and the second cam member 3
8, no magnetic path is formed. On the other hand, the yoke 36,
The magnetic path Z circulating between the rear housing 31b, the friction clutch 34, the armature 35, the friction clutch 34, the rear housing 31b, and the yoke 36 is well formed.

Therefore, even if the front housing 31a is formed only of an iron material, a magnetic path passing through the armature 35 via the second cam member 38 is not formed, and the armature 35
Can function normally as a part of the pilot clutch mechanism 30d, and the front housing 31a and the inner shaft 3
0b can be reliably transmitted.

(2) In this embodiment, the front housing 31a integrally having the input shaft 50 is formed only of an iron material. By the way, in the driving force transmission device disclosed in Japanese Patent Application Laid-Open No. H11-153159, a propeller shaft made of an iron material is fastened to a front housing made of an aluminum alloy by bolts. The front housing 31a of the present embodiment can be made compact and mass-produced because two members made of different metals are not fastened with bolts, compared to the front housing of the driving force transmission device.

In the differential device disclosed in JP-A-6-193689, the differential case (corresponding to the front housing 31a) is formed almost entirely of iron material, but the clutch plate (corresponds to the friction clutch 34). ) And the portion facing the armature was welded and fixed with stainless steel. Unlike the differential case of the differential device, the front housing 31a according to the present embodiment does not require a welding operation, so that the operation cost can be reduced, and the material cost can be reduced since stainless steel is not used.

(Second Embodiment) Hereinafter, a second embodiment of the present invention will be described with reference to FIGS.
Note that the second embodiment is a modification of the first embodiment, and for the same configuration as the first embodiment,
The same reference numerals are given, detailed descriptions thereof will be omitted, and different portions will be described in detail.

In the driving force transmission device 61 of the present embodiment, the aluminum A covering the armature 35 in the driving force transmission device 11 is omitted, the entire armature 35 is formed of iron, and the second cam member 38 is formed of stainless steel. It is formed by.

Therefore, even if a magnetic flux passes through the yoke 36, the rear housing 31b, and the front housing 31a by energizing the electromagnetic coil of the electromagnet 33, the magnetic flux does not flow therefrom to the second cam member 38 made of a non-magnetic material. .

As a result, a magnetic path circulating through the front housing 31a, the second cam member 38, the armature 35, and the front housing 31a is not formed, and the same functions and effects as those of the first embodiment are obtained. (Other Embodiments) Each of the above embodiments may be modified and embodied in the following other embodiments.

In the first embodiment, the armature 35
The other side not facing the outer clutch plate 34b is covered with aluminum A. However, the material that covers the armature 35 is not limited to aluminum A, and may be covered with a nonmagnetic material such as stainless steel, tin, platinum, synthetic resin, or ceramics. As a method for covering, for example, a known method such as plating or a mold may be used.

In the second embodiment, the second cam member 3
8 was made of stainless steel. However, the present invention is not limited to this, and the second cam member 38 is not limited to this as long as it is made of a non-magnetic material and has a wear resistance.

In the second embodiment, the second cam member 3
8 was made of a stainless steel material made of a non-magnetic material.
Alternatively, the second cam member 38 may be formed of a metal made of a magnetic material, for example, iron, and at least a side surface of the second cam member 38 on the armature 35 side may be covered with a nonmagnetic material. For example, examples of the nonmagnetic material include aluminum, stainless steel, tin, platinum, synthetic resin, and ceramics.

In the first embodiment, the second cam member 38 of the driving force transmission device 11 may be changed to the second cam member 38 of the driving force transmission device 61 of the second embodiment. Further, the second cam member 38 of the driving force transmission device 11 may be changed to any one of the second cam members 38 in the other embodiments.

Next, technical ideas other than the invention described in the claims that can be understood from the above embodiments and other embodiments will be described together with their effects. 4. The driving force transmission device according to claim 3, wherein, on the surface of the cam mechanism-side member facing the armature, a portion where the non-magnetic material is provided is only a side surface facing the armature. In this case, in the member on the cam mechanism side facing the armature, the nonmagnetic material may be provided only on the side surface facing the armature.

[0064]

According to the first or second aspect of the present invention, when the electromagnetic driving means is operated, a complicated magnetic path is not formed, so that an armature operation defect does not occur. Thus, torque transmission between the inner and outer rotating members can be reliably performed.

According to the second aspect of the present invention, since the outer rotating member can be formed of one material made of a magnetic material, the cost and mass production of the outer rotating member can be reduced. According to the invention described in claims 3 to 5, when the electromagnetic driving means is operated, no complicated magnetic path is formed, so that an armature operation defect does not occur, and the inner and outer rotating members are not generated. Torque transmission can be reliably performed.

According to the fourth aspect of the present invention, the effect of the third aspect can be obtained by forming the entire member on the cam mechanism side facing the armature from a non-magnetic material. According to the fifth aspect of the present invention, since the outer rotating member can be formed of one material made of a magnetic material, the cost and mass production of the outer rotating member can be reduced.

[Brief description of the drawings]

FIG. 1 is a partial cross-sectional view of a driving force transmission device according to a first embodiment.

FIG. 2 is an explanatory diagram of a four-wheel drive vehicle equipped with the driving force transmission device according to the first embodiment.

FIG. 3 is a cross-sectional view of a main part of the driving force transmission device according to the first embodiment.

FIG. 4 is an explanatory diagram showing a surface state of a second cam member in the first embodiment.

FIG. 5 is a characteristic diagram showing the relationship between the plate thickness of the armature and torque in the first embodiment.

[Explanation of symbols]

11, 61: driving force transmitting device, 30a: outer case as an outer rotating member, 30b: inner shaft as an inner rotating member, 30c: main clutch mechanism, 30d ...
Pilot clutch mechanism 31b Rear housing as side wall of outer rotating member 30e Cam mechanism 33 Electromagnet 34 Friction clutch 35 Armature 38
A second cam member as a member on the cam mechanism side facing the armature.

 ────────────────────────────────────────────────── ─── Continued on the front page (72) Inventor Yoshiaki Chiga 1-1-1 Asahi-cho, Kariya-shi, Aichi F-term in Toyota Industries Co., Ltd. F-term (reference) 3J057 AA01 AA09 BB04 GA49 GB21 GE16 HH02 JJ05

Claims (5)

[Claims] 1. A driving device comprising: a friction clutch disposed between inner and outer rotating members positioned so as to be able to rotate relative to each other; and an electromagnetic driving means that operates by energization to frictionally engage the friction clutch. An armature located inside the outer rotating member and facing the friction clutch, and an electromagnet located outside the outer rotating member and facing the friction clutch across the side wall of the outer rotating member. A driving force transmission device that attracts the armature by energizing the electromagnet, frictionally engages the friction clutch, and brings the two rotating members into a connected state capable of transmitting torque by the frictional engagement force of the friction clutch. , Wherein the side of the armature facing the friction clutch is formed of a magnetic material, and the other side not facing the friction clutch is covered with a non-magnetic material. Power transmission device. 2. The driving force transmission device according to claim 1, wherein the entire outer rotating member is formed of a magnetic material. 3. A main clutch mechanism for transmitting torque between the inner and outer rotating members by frictional engagement between the two rotating members, an electromagnetic pilot clutch mechanism for operating and frictionally engaging by energization, A cam mechanism which is located between a clutch mechanism and the pilot clutch mechanism and converts a frictional engagement force of the pilot clutch mechanism into a pressing force for the main clutch mechanism; and wherein the pilot clutch mechanism is provided between the inner and outer rotating members. A friction clutch provided, and an electromagnetic driving means that operates by energization to frictionally engage the friction clutch, wherein the driving means is located outside an armature facing the friction clutch and outside the outer rotating member. And a mechanism provided with an electromagnet opposed to the friction clutch with the side wall of the outer rotating member interposed therebetween. A driving force transmitting device that attracts the armature to frictionally engage the friction clutch, and brings the two rotating members into a connected state capable of transmitting torque by the frictional engagement force of the friction clutch. A driving force transmission device, wherein a non-magnetic material is provided on at least a surface of a mechanism-side member. 4. The driving force transmission device according to claim 3, wherein the member on the cam mechanism side facing the armature is entirely made of a non-magnetic material. 5. The driving force transmission device according to claim 3, wherein the entire outer rotating member is formed of a magnetic material.