JP2000257652A - Electromagnetic clutch - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide an electromagnetic clutch capable of improving responsiveness of connection of a clutch and capable of improving lubricity of lubricating oil, by eliminating time lag of armature attraction by excitation of an electromagnetic coil. SOLUTION: An armature 7 is so constituted as to be rotated together with a rotary shaft 1, and thrust generating means 7B are formed on the armature 7. The thrust generating means 7B formed on the armature 7 to be rotated together with the first rotary shaft 1 and relatively to lubricating oil stir effectively lubricating oil and generate axial thrust on the armature 7 to previously bring a multiple disc clutch of an electromagnetic clutch 5 into contact. In connection control of the electromagnetic clutch 5 by excitation of an electromagnetic coil 6, the control can be started without time lag, and responsiveness of the control can be drastically improved.

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a plate group disposed between a first coaxial rotation axis and a second coaxial rotation axis, and rotating together with the first rotation axis, and a second rotation axis. And a group of plates that rotate together are related to an electromagnetic clutch that is connected by pressing an armature that axially moves by excitation of an electromagnetic coil, and a type that transmits torque between a pair of rotating shafts, and a type that rotates a differential case. The present invention is applied to a differential limiting device that differentially distributes and transmits a pair of side gears and the like.

[0002]

2. Description of the Related Art Various types of torque transmission devices for limiting the relative rotation between a pair of rotating shafts rotatably supported on each other have been employed, and are usually arranged between the pair of rotating shafts. By connecting the provided multi-plate clutches, their relative rotation is restricted. Also, there are various types of connection methods of these multi-plate clutches. For example, there is a torque transmission device having an electromagnetic clutch 35 and a main clutch 33 which constitute a pilot clutch as shown in FIG. The torque transmission device includes a shim 42 and a main shaft 32 between an output shaft 31 that is an output shaft coaxially supported by the first rotation shaft 31 that constitutes the input shaft 30 and the rotation shaft 31. Cam devices 38, 39, 4 for pressing and connecting the clutch 33 in the axial direction
0, an electromagnetic clutch 35 for generating relative rotation for operating the cam device and a main clutch 33 composed of a multi-plate clutch group are assembled. These parts are closed by the lid member 34 and engaged by the snap ring 46. It is configured to stop and is called an electromagnetic torque transmission device.

[0003] The operation will be briefly described. When the armature 37 is attracted by the excitation of the electromagnetic coil 36 provided on the fixed-side support member 43, the armature 37 rotates with the first rotating shaft 31 and is movable in the axial direction. An electromagnetic clutch 35 composed of an outer plate group and an inner plate group that can move in the axial direction while rotating together with the cam ring 38 is pressed and connected, and the rotation of the first rotary shaft 31 is transmitted to the cam ring 38. You. As a result, a relative rotation difference is generated between the cam plate 39 and the cam ball 40, and the cam action between the cam ball 40 and the cam ring 38 causes the cam plate 39 to move in the axial direction via the cam ball 40 to cause the main clutch 33 to move. Press. Main clutch 33
Is composed of an outer plate group that can move in the axial direction while rotating together with the first rotating shaft 31 and an inner plate group that can move in the axial direction while rotating together with the second rotating shaft 32. The first rotating shaft 31 and the second rotating shaft 32 are pressed and connected by the cam plate 39.
Is suppressed, and torque transmission is performed.

[0004]

On the other hand, the electromagnetic clutch 3
Main clutch 33 composed of a group of multi-plate clutches connected via cam devices 38, 39 and 40 operated by
It is necessary that the connection of the main clutch 33 composed of the multi-plate clutch group be promptly performed. For that purpose, at least the gap between the multi-plate clutch comprising the outer plate and the inner plate constituting the main clutch 33 and the operation accuracy between the components in the cam device must be optimally adjusted without being too wide.
It is a matter of course that it is necessary to combine at least the outer plate and the inner plate of the main clutch into one having an optimum thickness. The cam devices 38, 39, 40 for pressing the main clutch 33 in the axial direction for connection are greatly affected by the response performance of the electromagnetic clutch 35, which is a pilot clutch. That is, the first rotating shaft 31 and the second rotating shaft 3
When it becomes necessary to connect between the electromagnetic coil 3
6, the armature 37 is attracted to the electromagnetic clutch 3
It is inevitable that the initial time delay during the connection of the armature 5, that is, the axis movement of the armature 37 requires a little time.

Accordingly, the present invention solves the problems of the electromagnetic clutch of the above-described conventional torque transmitting device, eliminates the time delay of armature suction due to excitation of the electromagnetic coil, and improves the clutch connection response. With
An object of the present invention is to provide an electromagnetic clutch capable of improving the lubricating performance of lubricating oil.

[0006]

SUMMARY OF THE INVENTION Accordingly, the present invention is directed to a plate group disposed between a first rotation axis and a second rotation axis which are coaxial and rotating together with the first rotation axis. The armature is configured to rotate together with the first rotation shaft in an electromagnetic clutch in which a plate group that rotates together with the rotation shaft of the electromagnetic clutch is connected by pressing an armature that axially moves by excitation of an electromagnetic coil. In addition, a thrust generating means is formed on the armature.
Further, the present invention is characterized in that the thrust generating means in the armature is formed on the end face opposite to the electromagnetic coil. Further, the present invention provides the electromagnetic clutch,
It is used as a pilot clutch for obtaining a rotational driving force for axially rotating a cam member for connecting a main clutch disposed between the first rotary shaft and the third rotary shaft. These are the means for solving the problems.

[0007]

DESCRIPTION OF THE PREFERRED EMBODIMENTS Embodiments of the present invention will be described below with reference to the drawings. 1 and 2 show a first embodiment of the electromagnetic clutch of the present invention.
1 shows an embodiment, in which FIG. 1 is an overall sectional view and an enlarged view of an armature of an electromagnetic torque transmission device in which the electromagnetic clutch of the present invention is employed as a pilot clutch, and FIG. 2 is an enlarged view of a main part of FIG. is there. The electromagnetic torque transmission device employing the electromagnetic clutch of the present invention has a structure in which a first rotating shaft 1 constituting an input shaft and a third rotating shaft 2 supported in the rotating shaft 1 are provided. A main clutch 3 comprising a group of plate clutches, cam devices 8, 9, 10 for pressing and connecting the main clutch 3 in the axial direction, and a pilot clutch for generating a relative rotation for operating the cam device. The electromagnetic clutch 5 and the rotor 4 are assembled. The main clutch 3 is preferably filled with lubricating oil such as ATF between the multiple disc clutch groups.

The fixed-side support member 13 (constituting a magnetic pole)
When the electromagnetic coil 6 installed in the rotor 4 is excited, the armature 7 made of a magnetic material, the electromagnetic clutch 5, the rotor 4, and the support member 13 extend around the non-magnetic material 22 provided in a part of the rotor 4. The armature 7 attracted by the formed magnetic flux causes the outer plate group movable in the axial direction together with the first rotating shaft 1 and the cam ring 8 forming the second rotating shaft to rotate together with the first rotating shaft 1. An electromagnetic clutch 5 composed of a group of inner plates movable in the axial direction is pressed and connected, and the rotation of the first rotating shaft 1 is transmitted to the cam ring 8 as the second rotating shaft. Is done. Then, with the rotation of the cam ring 8, a relative rotation difference is generated between the cam plate 9 and the cam ball 10,
A cam action between the cam ball 10 and the cam ring 8 causes the cam plate 9 to move in the axial direction via the cam ball 10 to press the main clutch 3. The main clutch 3 includes a group of outer plates 3A that can move in the axial direction while rotating together with the first rotating shaft 1, and a group of inner plates 3B that can move in the axial direction while rotating together with the third rotating shaft 2. And the cam plate 9
By pressing and connecting, the relative rotation between the first rotating shaft 1 and the third rotating shaft 2 is suppressed, and torque transmission such as a differential limiting operation is performed. Sign 1
2 is a cam device 8 in the electromagnetic torque transmission device,
This is a shim which constitutes a gap adjusting means provided between 9, 9 and the rotor 4. Preferably, the shim 12 is arranged with the needle bearing 11 between the cam ring 8 and the rotor 4 in the cam device.

According to the present invention, as shown in FIG. 1B, the armature 7 is configured to rotate together with the first rotary shaft 1 as an input shaft, and the armature 7 is provided with a thrust generating means. It is characterized by having been formed. This embodiment is a cam member that connects the electromagnetic clutch 5 to a main clutch 3 disposed between the first rotating shaft 1 and a third rotating shaft 2 that is an output shaft. It is used as a pilot clutch for obtaining a rotational driving force for rotating the second rotating shaft, that is, the cam ring 8. A spline 7S is engraved on the outer peripheral surface of the armature 7, and a large number of fins 7B as thrust generating means are protruded in the radial direction on the end surface opposite to the electromagnetic coil. Each of the fins 7B is formed on an inclined surface whose rear side in the rotation direction is higher as shown in the AA cross section. The spline 7S on the outer peripheral surface of the armature 7 is fitted to the spline 1S engraved on the inner peripheral surface of the first rotary shaft 1 so that the first rotary shaft 1
And rotate together. Further, the rotor 4 is configured so that the first rotating shaft 1 is restrained in the axial direction by a snap ring 16 to prevent the rotor 4 from coming off.

FIG. 2 is an enlarged view showing a main part. A gap adjusting means 12 such as a shim disposed between the needle bearing 11 and the wall surface 4A of the rotor 4 is provided after the apparatus is assembled.
If the gaps in the main clutch or electromagnetic clutch or the specifications in the cam device are inappropriate due to assembly errors or manufacturing errors, etc., and a high response of torque generation during torque transmission action cannot be obtained, The rotor 4, which is also referred to as a lid member, is removed by one-touch release of the snap ring 16, and is replaced with a shim having an appropriate thicker thickness to optimally adjust the gap in each part. Conversely, if the clearance is too small after assembly, causing unnecessary drag on the main clutch or the like, it is possible to optimally adjust the clearance in each part by replacing the shim with an appropriate shim having a smaller thickness. . After the replacement with the gap adjusting means having an appropriate thickness, the entire assembly is completed only by mounting the rotor 4 alone by locking the snap ring 16.

In the example shown in FIG. 2, the snap ring 16 is constructed such that the rotor 4 itself is slightly movable in the axial direction, its assembling position can be changed, and the outer end face of the rotor 4 is locked and restrained. Engagement recess 1 with sufficient length in the axial direction
7 is locked. By selectively using the snap rings 16 having different thicknesses, the assembling position of the rotor 4 is changed, so that a finer adjustment can be added to the gap adjusting function of the shim 12. Become. In FIG. 2, reference numeral 20 denotes an oil reservoir,
Is an oil seal such as an O-ring, 22 is a non-magnetic material such as stainless steel, 23 is a cutout on the outer periphery of the cam ring 8, 24 is an oil seal such as an X ring, 25 is a sliding bush, and 26 is a minimum gap between relative rotating members. (Air gap), 27 is a centering surface, and 28 is an output axle spline.

Thus, as shown in an enlarged view in FIG. 2, the spline 7S on the outer peripheral surface of the armature 7 is
For example, the torque transmission device according to the present embodiment can be attached to the left and right wheels of the vehicle by being fitted to a spline 1S engraved on the inner peripheral surface of the rotating shaft 1 and rotating together with the first rotating shaft 1. In the case of configuring a connected differential device, during normal traveling, the first rotating shaft 1 and the third rotating shaft 2 rotate only without causing relative rotation, but on a rough road. As a result, one of the wheels slips, causing a relative rotation between the first rotating shaft 1 and the third rotating shaft 2. As a result, the armature 7 rotates relative to the lubricating oil existing around the armature 7 together with the first rotating shaft 1, and a large number of fins 7 </ b> B formed on the end face of the armature 7 as thrust generating means are formed. Each of the fins 7B whose rear side is higher in the rotation direction (arrow in FIG. 1B) due to the relative rotation of the armature 7 in the lubricating oil while stirring the lubricating oil.
, An axial thrust is generated in the armature 7 to press the multiple disc clutch of the electromagnetic clutch 5 in advance. Therefore, when it becomes necessary to suppress the relative rotation between the first rotating shaft 1 and the third rotating shaft 2, that is, to perform a differential limiting operation or the like, the electromagnetic force of the electromagnetic clutch 5, which is a pilot clutch, is increased. Prior to exciting the coil 6, the multi-plate clutch is pressed in advance, so that there is almost no time lag,
The electromagnetic clutch 5 can be connected, and the control response performance can be significantly improved. This makes it possible to sufficiently exhibit the function of improving the response by the shim as the gap adjusting means.

FIG. 3 shows a second embodiment of the electromagnetic clutch according to the present invention. In this embodiment, the shape of a fin as a thrust generating means in an armature is devised in a front view. In the first embodiment, the fins 7B formed on the end face of the armature 7 are formed radially and spirally, while the fins 7B formed on the end face of the armature 7 are simply arranged radially. Things. As a result, a large number of armatures 7 are formed on the end face of the armature 7 which is fitted to the first rotating shaft 1 by the spline 7S on the outer peripheral surface and relatively rotates with the first rotating shaft 1 with respect to the lubricating oil existing around. The fins 7B more effectively agitate the lubricating oil, and generate an axial thrust on the armature 7 due to the inclined surface having a higher rotation direction (arrow) rear side as shown in the BB sectional view. Thus, the multi-plate clutch of the electromagnetic clutch 5 is brought into press-contact in advance, and the connection control of the electromagnetic clutch 5 by the excitation of the electromagnetic coil 6 to be performed next can be put on standby with almost no time lag.
As shown in FIG. 3, the spiral direction of each fin 7B is such that the radially outward fins 7B are oriented in the direction of rotation, the lubricating oil is rotated with the relative rotation of the armature 7 with respect to the lubricating oil. It is gathered by each fin 7B and flows toward the center of the armature 7, and the needle bearing 1
It is possible to effectively lubricate the first and other bearing portions.

FIG. 4 shows a third embodiment of the electromagnetic clutch according to the present invention. This embodiment is a modification of the form of the thrust generating means in the armature. In the embodiment, the armature 7 has a large number of radial fins 7B protruding from the end face thereof, whereas in the present embodiment, the inclined hole 7C penetrating between both end faces of the armature 7 is provided. Are provided on the circumference. Accordingly, the armature 7 is fitted to the first rotating shaft 1 by the spline 7S on the outer peripheral surface, and is formed between both end surfaces of the armature 7 which rotates relatively with the first rotating shaft 1 with respect to the lubricating oil existing around. The lubricating oil flows forcibly through the large number of inclined holes 7C. At this time, the lubricating oil is more effectively agitated, and the lubricating oil flowing through the inclined holes 7C reacts with the armature 7 by the reaction from the lubricating oil. A thrust in the direction is generated, the multi-plate clutch of the electromagnetic clutch 5 is pre-pressed, and the control of the connection of the electromagnetic clutch 5 by the excitation of the electromagnetic coil 6 to be performed next is started with almost no time lag. Can be. As the direction of each of the inclined holes 7C, as shown in FIG. 4, the outer side in the radial direction may be a lubricating oil inlet and the inner side in the radial direction may be a lubricating oil outlet. The outside may be the outlet for the lubricating oil. In any case, it is preferable to arrange the outlet side with respect to the entrance of the inclined hole 7C behind the armature 7 in the rotation direction. In the former case, the lubricating oil flows toward the center of the armature 7, and it is possible to effectively lubricate the bearings such as the needle bearing 11 and the like.

The embodiment of the present invention has been described above.
The present invention is applied to a type in which torque is transmitted between a pair of rotating shafts as in the above-described embodiment, and an electromagnetic type in which rotation of a differential case is differentially distributed to a pair of side gears and transmitted. It goes without saying that the present invention is also applied to a type differential limiting device and the like. In addition, the shape of the main clutch, the type and shape of the electromagnetic clutch and the like constituting the pilot clutch and the like, the type of the cam device, the shape of the first rotating shaft, the shape of the second rotating shaft, and the shape of the third rotating shaft; Related shapes between them, the shape of the armature, its form of engagement with the first rotating shaft, its form of connection to the electromagnetic clutch, the arrangement of thrust generating means on the armature, and the shape and form of these thrust generating means Can be appropriately adopted.

[0016]

As described in detail above, the present invention provides
Disposed between a first coaxial axis of rotation and a second coaxial axis of rotation;
An electromagnetic clutch in which a plate group that rotates together with the first rotation axis and a plate group that rotates together with the second rotation axis are connected by pressing an armature that axially moves by excitation of an electromagnetic coil. The first rotating shaft is configured to rotate together with the first rotating shaft, and the armature is formed with a thrust generating means, so that it is necessary to control the connection of the electromagnetic clutch. When the first rotating shaft starts to rotate relative to the oil, the thrust generating means formed on the armature that rotates relative to the lubricating oil together with the first rotating shaft effectively stirs the lubricating oil. At the same time, an axial thrust is generated in the armature to press the multiple disc clutch of the electromagnetic clutch in advance. Upon connection control switch is mostly able to start its control without time lag, the response performance of the control can be remarkably improved. This makes it possible to sufficiently back up the function of improving the response by the shim, which is the gap adjusting means, without wasting it.

Further, the thrust generating means in the armature is formed on the end face opposite to the electromagnetic coil, so that the lubricating oil can be effectively stirred without any hindrance to the clutch connection function of the armature. The degree of freedom of disposing the thrust generating means can be increased.
Further, the electromagnetic clutch is connected to the first rotation shaft and the third rotation shaft.
When it is used as a pilot clutch that obtains a rotational driving force for axially rotating a cam member that connects a main clutch disposed between the main clutch and a rotary shaft, a cam action to the main clutch connection occurs with almost no time lag. Therefore, the suitability of the piston clutch, which can reliably control the main clutch with a relatively small force, can be sufficiently exhibited. As described above, according to the present invention, it is possible to eliminate the time delay of the armature suction due to the excitation of the electromagnetic coil, improve the connection response of the clutch, and improve the lubrication performance of the lubricating oil. A clutch is provided.

[Brief description of the drawings]

FIG. 1 shows an electromagnetic clutch according to a first embodiment of the present invention, and is an overall sectional view and an enlarged view of an armature of an electromagnetic torque transmission device in which the electromagnetic clutch is employed as a pilot clutch.

FIG. 2 shows an electromagnetic clutch according to a first embodiment of the present invention, and is an enlarged view of a main part.

FIG. 3 is a view showing an armature according to a second embodiment of the electromagnetic clutch of the present invention.

FIG. 4 is a view showing an armature according to a third embodiment of the electromagnetic clutch of the present invention.

FIG. 5 is an overall sectional view of a conventional electromagnetic clutch.

[Explanation of symbols]

 DESCRIPTION OF SYMBOLS 1 1st rotating shaft (diff case) 1A wall surface 1S spline 2 3rd rotating shaft (output shaft) 3 main clutch 3A outer plate 3B inner plate 4 rotor 4A wall surface 5 electromagnetic clutch (pilot clutch) 6 electromagnetic coil 7 armature 7B thrust Generating means (fin) 7C Inclined hole 7S Spline 8 Cam ring 9 Cam plate 10 Cam ball 11 Needle bearing 12 Gap adjusting means (shim) 13 Support member 14 Bearing 15 Bearing 16 Snap ring

Claims (3)

[Claims] 1. A plate group disposed between a first coaxial rotation shaft and a second coaxial rotation shaft, the plate group rotating together with the first rotation shaft, and the plate coaxially rotating with the second rotation shaft. And an armature that is connected by pressing an armature that axially moves by excitation of an electromagnetic coil, wherein the armature is configured to rotate together with the first rotation shaft, and the armature is provided with thrust generating means. An electromagnetic clutch characterized by being formed. 2. The electromagnetic clutch according to claim 1, wherein the thrust generating means in the armature is formed on an end face opposite to the electromagnetic coil. 3. A pilot clutch for obtaining a rotational driving force for axially moving a cam member for connecting the electromagnetic clutch to a main clutch disposed between the first rotation shaft and the third rotation shaft. The electromagnetic clutch according to claim 1, wherein the electromagnetic clutch is used as a clutch.