JP2003254352A - Electromagnetic clutch device - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To implement sufficient torque transmission capacity without enlarging an electromagnet and a clutch. <P>SOLUTION: An electromagnetic clutch device comprises: a clutch 11 disposed between torque transmission members 7, 9; a clutch 19 disposed between a member 9 and an intermediate member 17; a plate 15 connected to the member 9; the electromagnet 25 pressing the clutch 19 by moving operation of an armature 23; a cam mechanism 13 which is disposed between the plate 15 and a ring 17, and is operated by receiving torque between the members 7, 9 when the clutch 19 is connected to move the plate 15 and thereby to connect the clutch 11; and an assist cam mechanism 27 disposed between the armature 23 and the plate 15 to enhance pressing force. <P>COPYRIGHT: (C)2003,JPO

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to an electromagnetic clutch device used in a power transmission system to interrupt power, or used in a differential device to interrupt driving force, and to limit differential.

[0002]

2. Description of the Related Art FIG.
Such a driving force transmission device 501 is described.

The driving force transmission device 501 includes a rotating case 503, an inner shaft 505, and a main clutch 50.
7, ball cam 509, pressure plate 511,
The cam ring 513, the pilot clutch 515, the armature 517, the electromagnet 519 and the like are included.

The driving force transmission device 501 is arranged so as to divide the propeller shaft on the rear wheel side, which is separated during traveling on two-wheel drive in a four-wheel drive vehicle, and the rotation case 503 is connected to the propeller shaft on the front side. The shaft 505 is connected to the rear propeller shaft.

When the electromagnet 519 is excited, the magnetic loop 5
21 is formed, the armature 517 is attracted, and the pilot clutch 515 is pressed and fastened. When the pilot clutch 515 is engaged, a pilot torque is generated to apply a driving force of the engine to the ball cam 509, the generated cam thrust force presses the main clutch 507, and the driving force transmission device 501 is connected to drive to the rear wheel side. The force is transmitted and the vehicle is in a four-wheel drive state.

When the excitation of the electromagnet 519 is stopped,
The pilot clutch 515 is released and the ball cam 50 is released.
The cam thrust force of No. 9 disappears, the main clutch 507 is released, the drive force transmission device 501 is disconnected, the rear wheel side is disconnected, and the vehicle enters the two-wheel drive state.

[0007]

The driving force transmission device 5 described above.
01, main clutch, pilot clutch,
The electromagnetic clutch device, which is composed of a cam mechanism, etc., that activates the cam mechanism when the pilot clutch is engaged and strengthens the engagement force of the main clutch, is used as a power interrupting device by itself, and also as an interrupting mechanism on the differential device. Used.

A differential device equipped with such an interrupting mechanism is, for example, a four-wheel drive hybrid electric vehicle in which a fuel engine (a normal engine utilizing the explosion of fuel) and an electric motor are used together as a prime mover. It is sometimes used in power transmission systems.

However, in such applications, it may be pointed out that the torque transmission capacity of the electromagnetic clutch device is insufficient.

However, in order to increase the torque transmission capacity (increase the torque), it is necessary to increase the number of friction surfaces of the main clutch and pilot clutch (the number of clutch plates). In addition to an excessive drag torque due to viscosity, the differential device may become large and heavy, which may reduce the vehicle mountability.

On the other hand, in order to increase the torque transmission capacity without increasing the number of friction surfaces of the clutch, it is sufficient to increase the pilot torque. For that purpose, it is necessary to enlarge the electromagnet and strengthen the attractive force.

However, even if the electromagnet is made large, a sufficient attraction force may not be obtained due to the electric resistance of the electromagnetic coil or the saturation of the magnetic path (magnetic resistance). Further, if the electromagnet becomes large, The burden on the battery increases, the fuel efficiency of the engine decreases, and the problem of the installation space arises.

Therefore, an object of the present invention is to provide an electromagnetic clutch device which can obtain a sufficient torque transmission capacity without increasing the size of the electromagnet and the clutch.

[0014]

According to another aspect of the present invention, there is provided an electromagnetic clutch device including a pair of torque transmission members, a main clutch disposed between the torque transmission members, and one of the torque transmission members and an intermediate member. The pilot clutch disposed in the, the pressure plate movably connected to the other of the torque transmission member, and the armature are moved,
It is arranged between the electromagnet that presses and fastens the pilot clutch and the pressure plate and the intermediate member.When the pilot clutch is connected, it operates by receiving the torque between both torque transmission members and moves the pressure plate to the main An electromagnetic clutch device including a cam mechanism for connecting a clutch, wherein the armature and the pressure plate are actuated by receiving the torque when the armature is pressed against the pilot clutch by an electromagnet, and the pilot clutch of the armature is operated. The feature is that an assist cam mechanism for strengthening the pressing force is provided.

As described above, in the electromagnetic clutch device of the present invention, the pilot torque is strengthened by providing the assist cam mechanism for pressing the pilot clutch between the armature and the pressure plate. The cam thrust force of the cam mechanism that moves the plate is increased, and the torque transmission capacity of the main clutch is strengthened.

Therefore, when the differential device using the electromagnetic clutch device as the disengagement mechanism is used in the power transmission system on the electric motor side of the four-wheel drive hybrid electric vehicle as described above, a sufficient torque transmission capacity can be obtained.

Further, since it is not necessary to increase the number of friction surfaces (the number of clutch plates) of the main clutch and the pilot clutch in order to increase the torque transmission capacity, it is possible to prevent an increase in drag torque due to the lubricating oil, and
It is possible to prevent the electromagnetic clutch device and the differential device using the electromagnetic clutch device from becoming large in size, heavy in weight, and deteriorated in vehicle mountability.

Further, it is not necessary to enlarge the electromagnet in order to increase the pilot torque, and the electric resistance of the electromagnetic coil and the magnetic path saturation due to the enlargement of the electromagnet are released, and the burden on the battery and the fuel consumption of the engine are increased. It also frees you from the problem of lowering the installation space.

The invention of claim 2 is the electromagnetic clutch device according to claim 1, wherein the assist cam mechanism is:
The cam slope is a cam that generates the thrust force by receiving the torque, and the same action and effect as the configuration of claim 1 can be obtained.

In the case of a cam having a cam slope, the cam thrust force can be changed by changing the cam angle, and the torque transmission capacity of the electromagnetic clutch device (main clutch) can be adjusted.

Further, as in the third aspect of the present invention, the self-locking of the assist cam mechanism can be prevented by adjusting the cam angle.

A cam having a cam slope can be easily formed at low cost by press working.
Therefore, it is possible to easily cope with the change of the cam angle as described above at low cost.

According to a third aspect of the present invention, in the electromagnetic clutch device according to the second aspect, the cam angle of the cam is set within a range that does not self-lock even if the armature rotates due to inertial force or oil viscosity. It is characterized by doing,
It is possible to obtain the same operation and effect as the configuration of claim 2.

Further, by adjusting the cam angle, even if the armature rotates due to inertial force or oil viscosity, the self-locking of the assist cam mechanism is prevented, so that the electromagnetic clutch device and the differential device using the same are prevented. Function is maintained normally.

The invention of claim 4 is the electromagnetic clutch device according to any one of claims 1 to 3, wherein the pressure plate is provided with a step portion, and at least a part of the armature is the step portion. It is characterized in that it is arranged in the portion, and it is possible to obtain the same operation and effect as the constitutions of claims 1 to 3.

Further, since at least a part of the armature is arranged in the step portion of the pressure plate and the space is effectively used, the electromagnetic clutch device and the differential device using the electromagnetic clutch device are compactly constructed, and the vehicle mountability is improved. To do.

A fifth aspect of the present invention is the electromagnetic clutch device according to any one of the first to fourth aspects, further comprising a return spring for urging the armature in a direction opposite to a moving operation force of the electromagnet. This is characterized in that the same actions and effects as those of the first to fourth aspects can be obtained.

Further, since the armature is urged by the return spring in the direction opposite to the moving operation force of the electromagnet (disconnection direction of the pilot clutch), when the excitation of the electromagnet is released, the armature instantaneously moves (retracts). The pilot clutch is disengaged.

Therefore, the disconnection response of the electromagnetic clutch device and the differential device using the electromagnetic clutch device is improved, and drag torque due to poor movement of the armature is prevented.

A sixth aspect of the present invention is the electromagnetic clutch device according to any one of the first to fifth aspects, wherein the cam mechanism and the assist cam mechanism are axially overlapped with each other. This is a feature, and it is possible to obtain the same actions and effects as the configurations of claims 1 to 5.

Further, in this structure in which the cam mechanism and the assist cam mechanism are arranged so as to overlap each other in the axial direction (the respective radial projections are arranged to overlap each other), the electromagnetic clutch device and the differential device using the same are axially arranged. Directionally compact and easy to mount.

An invention according to claim 7 is the electromagnetic clutch device according to any one of claims 1 to 6, wherein an outer differential case which is rotated by a driving force of a prime mover and an inner case which is connected with a differential mechanism. In the differential device including the above, the outer differential case and the inner differential case are used as the torque transmission member, and the same actions and effects as the configurations of claims 1 to 6 can be obtained.

According to this structure, the connection / disconnection mechanism of the differential device in which the driving force is connected / disconnected by the connection / disconnection mechanism arranged on the input side of the differential mechanism (between the outer differential case and the inner differential case) is connected to the electromagnetic mechanism according to claim 1. This differential device uses a clutch device, and even if it is used in a power transmission system on the electric motor side of a four-wheel drive hybrid electric vehicle in which a fuel engine and an electric motor are used together as a prime mover, the differential mechanism described above can be used by the assist cam mechanism. In addition, a sufficient torque transmission capacity can be obtained.

Further, when the differential device using the electromagnetic clutch device is used in the electric vehicle as described above, the drag torque is prevented from increasing due to the viscosity of the lubricating oil or the defective movement of the armature in the two-wheel drive state. In addition to improving vehicle turning performance, maneuverability, engine fuel economy, etc., the effect of increasing the number of friction surfaces between the main clutch and pilot clutch and the effect of increasing the size of the electromagnet prevent the vehicle from increasing in size, weight, and installation space. Performance, increased battery load, and reduced fuel consumption are prevented.

The differential device can be used in a four-wheel drive hybrid electric vehicle using a fuel engine and an electric motor as a driving force source, or in a normal four-wheel drive vehicle using a fuel engine as a driving force source. It is also possible to obtain sufficient torque transmission capacity.

The invention of claim 8 is the electromagnetic clutch device according to any one of claims 1 to 6, wherein the driving force of the prime mover input from the differential rotating member on the input side is supplied to the pair of output differentials. In the differential device provided with the differential mechanism that distributes from the rotating member to the wheel side, any two of the input side differential rotating member and the output side differential rotating member are the torque transmitting members, It is possible to obtain the same actions and effects as the configurations of claims 1 to 6.

In this structure, the electromagnetic clutch device according to any one of claims 1 to 6 is used for the differential limiting mechanism of the differential device. When the electromagnetic clutch device is connected, the differential of the differential mechanism is limited, and the electromagnetic clutch is limited. The differential can be freed by uncoupling the device.

Further, since this differential device is constructed by using the electromagnetic clutch device according to the first to sixth aspects, the same effect as that of the differential device according to the seventh aspect can be obtained.

Further, this differential device can be used in a four-wheel drive hybrid electric vehicle in which an engine and an electric motor are used together as a driving force source, or in an electric vehicle in which only an electric motor is used as a driving force source. In either case, sufficient torque capacity (differential limiting force) can be obtained.

[0040]

DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS A rear differential 1 and an electromagnetic clutch device 3 (one embodiment of the present invention) used therein will be described with reference to FIGS. In the following description, the left and right directions are the left and right directions in each drawing.

The rear differential 1 (differential device for distributing the driving force of the prime mover to the left and right rear wheels) is a hybrid 4
Used in wheel drive vehicles.

This four-wheel drive vehicle is a hybrid electric vehicle in which the front wheels are driven by a reciprocating fuel engine and the rear wheels are driven by an electric motor. The rear differential 1 is used in the power transmission system on the rear wheel side.

The power system on the front wheel side is composed of a horizontally mounted engine, a transmission, a front differential (a differential device for distributing the driving force of the engine to the left and right front wheels), a front axle, left and right front wheels, and the like.

The power system on the rear wheel side is composed of an electric motor, a speed reducer, a rear differential 1, a battery, a sensor, a controller, a rear axle, left and right rear wheels, and the like.

The electric motor, the speed reducing mechanism and the rear differential 1 are housed in a casing. The electric motor is fixed to the casing and is connected to the battery via the controller. An oil sump is provided in this casing.

The speed reduction mechanism is composed of two speed reduction gear sets, the electric motor is connected to the front speed gear set, and the rear differential 1 is connected to the rear speed gear set.

The controller drives the electric motor, adjusts the number of revolutions, stops driving, etc. based on the information from the sensor.

Further, as described below, the controller stops the driving of the electric motor during normal traveling, and cuts off the driving force at the rear differential 1 to stop the operation of the rear wheel side power system as described below. At the same time, the front wheels are driven by the engine to bring the vehicle into a two-wheel drive state by the front wheel side power system.

When a large driving force is required, the controller drives the electric motor, and also connects the rear differential 1 to operate the rear wheel side power system to auxiliary drive the rear wheels to drive the four wheels of the vehicle. Drive to drive.

The driving force of the electric motor is decelerated by each reduction gear set to the traveling rotational speed range of the rear wheels, the torque is amplified and transmitted to the rear differential 1.

The rear differential 1 is composed of an electromagnetic clutch device 3 and a bevel gear type differential mechanism 5.

The electromagnetic clutch device 3 includes an outer differential case 7 (one torque transmitting member), an inner differential case 9 (the other torque transmitting member), a multi-plate main clutch 11, a ball cam 13 (cam mechanism), and a pressure plate 15. , Cam ring 17 (intermediate member), multi-plate pilot clutch 19, first return spring 2
1, armature 23, electromagnet 25, assist cam 27
(Assist cam mechanism: cam having a cam slope), a second return spring 29, and the like.

The outer differential case 7 is formed with a large-diameter gear 31, which is one side gear of the reduction gear set at the rear stage.
The large-diameter gear 31 portion of the outer differential case 7 is supported on the inner differential case 9 by ball bearings 33, 33. The outer differential case 7 has a gear 31.
It has a floating structure that is released from the supporting function of the members by only transmitting the torque.

The inner differential case 9 has a left boss portion 35.
Is supported on the casing by a ball bearing 37, and the right boss 39 is supported on the casing via a ball bearing 41 and a core 43 of the electromagnet 25 fixed to the casing.

A rotor 45 made of a magnetic material is fixed to the outer periphery of the right boss portion 39 (inner differential case 9) by a snap ring 47 and positioned axially. The rotor 45 also serves as the right side wall of the outer differential case 7.

The main clutch 11 is arranged between the outer differential case 7 and the inner differential case 9.
The outer plate 49 is spline-connected to the inner circumference of the outer differential case 7, and the inner plate 51 is spline-connected to the outer circumference of the inner differential case 9.

The pressure receiving ring 53 of the main clutch 11 is fixed to the inner differential case 9 by a snap ring 55.

The pilot clutch 19 is arranged between the outer differential case 7 and the cam ring 17. The outer plate 57 is spline-connected to the inner circumference of the outer differential case 7, and the inner plate 59 is spline-connected to the outer circumference of the cam ring 17.

The ball cam 13 is the pressure plate 1.
5 and the cam ring 17. The pressure plate 15 is spline-connected to the outer periphery of the inner differential case 9 so as to be movable in the axial direction, and receives the cam thrust force of the ball cam 13 to press the main clutch 11 as described below.

Further, a thrust bearing 61 is arranged between the cam ring 17 and the rotor 45 to receive the cam reaction force of the ball cam 13 and to absorb the relative rotation between the cam ring 17 and the rotor 45.

The return spring 21 is arranged between the pressure plate 15 and the inner differential case 9, and the pressure plate 15 is connected to the main clutch 1.
It is biased in the disconnecting direction of 1.

The armature 23 includes a pressure plate 15 and a pilot clutch 19 (inner plate 5
9) and is arranged so as to be axially movable and rotatable. Also, the armature 23 is the pressure plate 15
The armature 23 is housed in the stepped portion 63 formed on the outer peripheral surface of the stepped portion 63 and is centered.

The lead wire of the electromagnet 25 is drawn out of the casing via the grommet and is connected to the battery side by the connector.

An appropriate air gap is formed between the core 43 of the electromagnet 25 and the rotor 45.
Air gap, rotor 45, pilot clutch 19,
The armature 23 constitutes the magnetic path of the electromagnet 25, and when the electromagnet 25 is excited, a magnetic flux loop 65 is formed on this magnetic path.

The differential mechanism 5 includes a plurality of pinion shafts 67, a pinion gear 69, and output side gears 71 and 7.
It is composed of 3 etc.

The pinion shafts 67 are arranged radially from the center of rotation of the inner differential case 9, and the tips of the pinion shafts 67 engage with the engaging holes 75 of the inner differential case 9 and are prevented from rotating on the pressure receiving ring 53 at the step 77. Has been done.

Each pinion gear 69 is rotatably supported on each pinion shaft 67, and the side gears 71 and 73 mesh with the pinion gear 69 from the left and right. Further, thrust washers 79 which receive the meshing reaction force of the side gears 71, 73 are arranged between the side gears 71, 73 and the inner differential case 9, respectively.

The side gears 71 and 73 are spline-coupled to the left and right rear axles, respectively, and the rear axles respectively penetrate the left and right boss portions 35 and 39 of the inner differential case 9 and the casing and are coupled to the left and right rear wheels. There is.

The rotation of the inner differential case 9 is distributed from the pinion shaft 67 to the side gears 71 and 73 via the pinion gear 69, and is further transmitted from the rear axle to the left and right rear wheels.

As shown in FIG. 2, the assist cam 27 is composed of a cam slope 83 formed on the pressure plate 15 and a cam slope 85 formed on the armature 23. The cam angles of these cam slopes 83 and 85 are set within a range in which even if the armature 23 rotates due to inertial force or oil viscosity, self-locking does not occur at this level of torque.

Further, as shown in FIG. 1, the assist cam 27 and the ball cam 13 are arranged so as to overlap in the axial direction (so that their radial projections overlap each other).

The return spring 29 is arranged between the snap ring 87 attached to the outer differential case 7 and the armature 23, and the armature 23 is directed in the direction opposite to the attraction force of the electromagnet 25 (the pilot clutch 19).
In the uncoupling direction).

The controller performs the excitation of the electromagnet 25, the control of the excitation current, and the stop of the excitation, depending on the road surface condition detected by the sensor, the traveling conditions such as starting, acceleration, and turning of the vehicle and the steering conditions.

Further, the controller excites the electromagnet 25 at the same time when the electric motor is rotated, and simultaneously stops the excitation of the electromagnet 25 when the rotation of the electric motor is stopped.

When the electromagnet 25 is excited, the magnetic flux loop 65 is formed on the magnetic path as described above, the armature 23 is attracted, and the pilot clutch 19 is engaged with the rotor 45.
Press to tighten and generate pilot torque.

When the pilot torque is generated, the driving force of the electric motor is applied to the ball cam 13 via the cam ring 17 connected to the outer differential case 7 by the pilot clutch 19 and the pressure plate 15 on the inner differential case 9, and the ball cam 13 is Due to the generated cam thrust force, the pressure plate 15 is moved to the left to press and engage the main clutch 11.

At this time, the pilot clutch 19
Similarly, the driving force of the electric motor is applied between the armature 23 that is sucked to the side and integrated with the outer differential case 7 and the pressure plate 15 on the inner differential case 9 side. By operating, the generated cam thrust force further tightens the pilot clutch 19 to strengthen the pilot torque,
The torque transmission capacity of the main clutch 11 increases accordingly.

The assist cam 27 is the ball cam 1
With the cam thrust force of 3, the pressure plate 15
Moves to the left and then activates.

When the electromagnetic clutch device 3 is connected in this way, the driving force of the electric motor for rotating the large diameter gear 31 (outer differential case 7) is transmitted to the inner differential case 9, and the rotation thereof is moved to the left and right by the differential mechanism 5. It is distributed to the rear wheels and the vehicle is in the four-wheel drive state.

When a drive resistance difference occurs between the rear wheels on a bad road or the like, the drive force of the electric motor is differentially distributed to the left and right rear wheels by the rotation of the pinion gear 69.

When the exciting current of the electromagnet 25 is controlled, the slip ratio of the pilot clutch 19 changes, the cam thrust force of the ball cam 13 and the assist cam 27 changes, and the driving force transmitted to the rear wheel side is controlled.

If such control of the driving force is performed during turning, for example, the turning performance and the stability of the vehicle body can be greatly improved.

When the excitation of the electromagnet 25 is stopped, the pilot clutch 19 is released, the cam thrust force of the ball cam 13 and the cam thrust force (assist action) of the assist cam 27 disappear, and the biasing force of the return spring 21 causes the pressure plate to move. 15 returns to the right, the main clutch 11 is released, the connection of the electromagnetic clutch device 3 is released, and the vehicle enters the two-wheel drive state of front wheel drive.

Further, since the return spring 29 urges the armature 23 in the disengagement direction of the pilot clutch 19, when the excitation of the electromagnet 25 is released, the armature 23 instantly moves to the left and the pilot clutch 19 is released. Of the electromagnetic clutch device 3 (rear differential 1) is improved.

Further, since the disengagement operation of the electromagnetic clutch device 3 is performed at the same time as the stop operation of the electric motor as described above, in the two-wheel drive state, the outer differential case 7, the reduction mechanism and the electric motor are driven by the rear wheels. Separated from the surroundings,
It is prevented from being mechanically turned.

Therefore, the circuit elements of the integrated circuit, such as the reduction mechanism, the electric motor and its bearings, the battery, the regulator, etc., are protected from the adverse effects caused by the rotation of the rear wheels.
The durability is improved.

The oil in the oil reservoir provided in the casing is repelled by the rotation of the outer differential case 7 (large-diameter gear 31), and the repelled oil comes from the gaps on the left and right sides of the outer differential case 7 and the inner differential case 9. Infiltrate between these, pilot clutch 1
9, sliding portion (stepped portion 63) between the armature 23 and the pressure plate 15, the ball cam 13, the assist cam 2
7. Lubricate and cool the thrust bearing 61, the main clutch 11, and the like.

Further, the oil in the oil sump flows in along with the rotation of the inner differential case 9 through the opening 89 of the inner differential case 9 and the spiral oil groove formed inside the boss portions 35, 39. Each gear 6 of the differential mechanism 5
After lubricating and cooling the meshing parts of 9, 71, 73, etc., further moving to the main clutch 11 side by receiving centrifugal force, after lubricating and cooling the main clutch 11, the ball cam 13, the pilot clutch 19, the assist cam 27, etc. , Return to the oil sump.

Thus, the rear differential 1 and the electromagnetic clutch device 3 are constructed.

The rear differential 1 and the electromagnetic clutch device 3 are used in the electric vehicle as described above because the torque transmission capacity of the main clutch 11 is enhanced by the assist cam 27 provided between the armature 23 and the pressure plate 15. However, sufficient torque transmission capacity can be obtained.

Further, since it is not necessary to increase the number of plates of the main clutch 11 and the pilot clutch 19 in order to increase the torque transmission capacity, the drag torque is prevented from increasing due to the lubricating oil, and the rear differential 1 is increased in size and weight. And deterioration of vehicle mountability are prevented.

Further, it is not necessary to increase the size of the electromagnet 25 in order to increase the pilot torque, and it is possible to prevent an increase in the burden on the battery and a decrease in fuel consumption due to the increase.

Further, since the cam angle of the assist cam 27 is set to an angle at which self-lock does not occur, the functions of the electromagnetic clutch device 3 and the rear differential 1 can be normally maintained.

Further, the assist cam 27 having a cam slope is provided.
Can be easily formed at a low cost by pressing the pressure plate 15 and the armature 23, so that the change of the cam angle as described above can be easily coped with at a low cost.

By arranging the armature 23 on the stepped portion 63 of the pressure plate 15 and effectively utilizing the space, the electromagnetic clutch device 3 and the rear differential 1 are made compact as much, and the vehicle mountability is improved.

In addition, the assist cam 27 and the ball cam 13
The electromagnetic clutch device 3 and the rear differential 1 are compact in the axial direction because they are axially overlapped, and the vehicle mountability is further improved.

When the excitation of the electromagnet 25 is released, the return spring 29 causes the pilot clutch 19 to move.
Since the connection is immediately released, the connection release response between the electromagnetic clutch device 3 and the rear differential 1 is improved, and drag torque due to poor movement of the armature 23 is prevented.

Further, since the drag torque prevention effect due to the oil viscosity and the drag torque prevention effect due to the poor movement of the armature 23 are almost completely cut off from the accompanying rotation of the rear wheels during the two-wheel drive traveling, Electric motor,
Circuit elements such as bearings, batteries, and regulators are freed from the influence of drag torque that accompanies the rear wheel.

Further, the differential mechanism of the differential device in which the electromagnetic clutch device of the present invention is used is not limited to the bevel gear type differential mechanism as in the embodiment, but the planetary gear type differential mechanism and the differential case accommodating hole. Any type of differential mechanism may be used, such as a differential mechanism in which a side gear on the output side is connected by a pinion gear slidably accommodated in, a differential mechanism using a worm gear, and the like.

[0100]

In the electromagnetic clutch device of the present invention, the torque transmission capacity is strengthened by the assist cam mechanism. Therefore, for example, a differential device using this electromagnetic clutch device as an intermittent mechanism has a sufficient torque even when used in an electric vehicle. The transfer capacity is obtained.

Further, it is not necessary to increase the number of friction surfaces of the main clutch and pilot clutch, the drag torque is prevented from increasing due to the viscosity of the oil, and the electromagnetic clutch device and the differential device using the electromagnetic clutch device are increased in size and weight. In addition, deterioration of vehicle mountability is prevented.

Further, there is no need to increase the size of the electromagnet, and the problem of increased battery load, reduced engine fuel consumption, and arrangement space due to the increased size of the electromagnet can be solved.

An electromagnetic clutch device according to a second aspect is the electromagnetic clutch device according to the first aspect.
It is possible to obtain the same effect as that of the configuration.

Further, the cam having the cam slope can adjust the torque transmission capacity of the electromagnetic clutch device by changing the cam angle.

Further, the cam having the cam slope can be formed at low cost by press working, and can easily cope with the change of the cam angle as described above.

The electromagnetic clutch device of claim 3 is the same as that of claim 2
It is possible to obtain the same effect as that of the configuration.

Further, even if the armature rotates due to the inertial force and the viscosity of the oil, self-locking is prevented, so that the functions of the electromagnetic clutch device and the differential device using the electromagnetic clutch device are normally maintained.

An electromagnetic clutch device according to a fourth aspect is the electromagnetic clutch device according to the first aspect.
It is possible to obtain the same effects as those of the configurations of 3 to 3.

Further, by arranging the armature at the stepped portion of the pressure plate and effectively utilizing the space, the electromagnetic clutch device and the differential device using the same are compactly constructed, and the vehicle mountability is improved.

An electromagnetic clutch device according to a fifth aspect of the present invention is the electromagnetic clutch device according to the first aspect.
It is possible to obtain the same effects as the configurations of 4 to 4.

Further, the return spring improves the disengagement response of the electromagnetic clutch device and the differential device using the electromagnetic clutch device, and prevents drag torque due to poor movement of the armature.

An electromagnetic clutch device according to a sixth aspect is the electromagnetic clutch device according to the first aspect.
It is possible to obtain the same effects as those of the configurations of 5 to 5.

Further, by arranging the cam mechanism and the assist cam mechanism so as to overlap each other in the axial direction, the electromagnetic clutch device and the differential device using the electromagnetic clutch device are axially compact and the vehicle mountability is improved.

The electromagnetic clutch device according to claim 7 is the electromagnetic clutch device according to claim 1.
It is possible to obtain the same effects as those of the configurations of 6 to 6.

Further, the differential device using the electromagnetic clutch device of the present invention as the engaging / disengaging mechanism can obtain a sufficient torque transmission capacity even when used in the above-described four-wheel drive hybrid electric vehicle, and the two-wheel drive state. This prevents drag torque from increasing due to oil viscosity and poor armature movement, improving vehicle turning performance, maneuverability, fuel efficiency, etc., and preventing the increase in the number of friction surfaces between the main clutch and pilot clutch and increasing the size of the electromagnet. Depending on the prevention effect,
It is possible to prevent a decrease in vehicle mountability, an increase in battery load, and a decrease in fuel consumption due to an increase in size, weight, and increase in installation space.

The electromagnetic clutch device according to claim 8 is the electromagnetic clutch device according to claim 1.
It is possible to obtain the same effects as those of the configurations of 6 to 6.

[Brief description of drawings]

FIG. 1 is a sectional view showing an embodiment of the present invention.

2 is an assist cam 27 used in the embodiment of FIG.
It is a sectional view showing a cam slope.

FIG. 3 is a sectional view of a conventional example.

[Explanation of symbols]

1 Rear Differential (Differential Device Using Electromagnetic Clutch Device as Intermittent Mechanism) 3 Electromagnetic Clutch Device 5 Bevel Gear Type Differential Mechanism 7 Outer Differential Case (One Torque Transmission Member) 9 Inner Differential Case (Other Torque Transmission Member) 11 Main Clutch 13 Ball cam (cam mechanism) 15 Pressure plate 17 Cam ring (intermediate member) 19 Pilot clutch 23 Armature 25 Electromagnet 27 Assist cam (assist cam mechanism: cam with cam slope) 29 Return spring

Claims (8)

[Claims] 1. A pair of torque transmission members, a main clutch arranged between the torque transmission members, a pilot clutch arranged between one of the torque transmission members and an intermediate member, and the other of the torque transmission members. Is arranged between the pressure plate and the intermediate member, and the pressure plate is movably connected to the electromagnet, and the electromagnet that moves and operates the armature to press and fasten the pilot clutch. An electromagnetic clutch device including a cam mechanism that operates by receiving torque between torque transmitting members to move a pressure plate to connect a main clutch, wherein an armature is piloted by an electromagnet between the armature and the pressure plate. When it is pressed by the clutch, it receives the torque and operates, and the armature An electromagnetic clutch device characterized by being provided with an assist cam mechanism for strengthening the pressing force of the pilot clutch. 2. The electromagnetic clutch device according to claim 1, wherein the assist cam mechanism is a cam that receives the torque on a cam slope and generates a thrust force. 3. The invention according to claim 2, wherein the cam angle of the cam is set to a range in which the armature does not self-lock even when the armature rotates due to inertial force or oil viscosity. Clutch device. 4. The invention according to claim 1, wherein the pressure plate is provided with a step portion, and at least a part of the armature is arranged in the step portion. An electromagnetic clutch device. 5. The electromagnetic clutch according to claim 1, further comprising a return spring that biases the armature in a direction opposite to a moving operation force of an electromagnet. apparatus. 6. The electromagnetic clutch device according to claim 1, wherein the cam mechanism and the assist cam mechanism are axially overlapped with each other. 7. The differential device according to any one of claims 1 to 6, comprising an outer differential case that is rotated by a driving force of a prime mover, and an inner case to which a differential mechanism is connected, An electromagnetic clutch device, wherein the outer differential case and the inner differential case are the torque transmitting members. 8. The invention according to claim 1, wherein the driving force of the prime mover input from the differential rotating member on the input side is distributed from the pair of differential rotating members on the output side to the wheel side. In the differential device including the differential mechanism, the electromagnetic clutch device is characterized in that any one of the input side differential rotation member and the output side differential rotation member is the torque transmission member.