JP2008275049A - Electromagnetic friction clutch - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To provide an electromagnetic friction clutch which can perform the suppression of the clearance between a plate and a rotor or an armature due to burrs, and further can solve other problems. <P>SOLUTION: An electromagnetic friction clutch 1 comprises an outer plate 47 to be rotationally engaged with a clutch housing 3, and an inner plate 45 to be rotationally engaged with a cam plate 35. The outer plate 47 and the inner plate 45 have through-holes 61, 57 in their intermediate portions in the radial direction. Magnetic paths are formed between the rotor 11 and the armature 39 via the through-holes 57, 61, and the outer plate 47 and the inner plate 45 are fixed between the rotor 11 and the armature 39. The rotor 11 and the armature 39 are provided with circumferential recesses 75, 73 and circumferential relieved portions 81, 77, 79 formed as relieved portions so as to avoid the contact of the through-holes 61 of the neighboring outer plates 47 with the edge portions 69, 71 on the inner and outer circumferences. <P>COPYRIGHT: (C)2009,JPO&INPIT

Description

  The present invention relates to an electromagnetic friction clutch.

As a conventional electromagnetic friction clutch, there exists a thing of patent document 1, for example.
This electromagnetic friction clutch includes an electromagnet, an armature, a cam mechanism, a main clutch, and a pilot clutch.

  The pilot clutch includes an outer plate that is alternately arranged between the rotor and the armature and that is rotationally engaged with the clutch housing, and an inner plate that is rotationally engaged with the cam mechanism.

  The outer plate and the inner plate have a through hole that forms a non-magnetic portion at a radially intermediate portion, and a magnetic path by an electromagnet is formed between the rotor and the armature via the through hole. And an inner plate is fastened between the rotor and the armature.

  When the pilot clutch is engaged, the cam mechanism is activated and the main clutch is engaged.

  By the way, the outer plate adjacent to the rotor or armature may leave press-formed burrs at the edge of the through hole or the inner and outer peripheral edges.・ There was a risk that a gap would be created between the plate and the rotor or armature, and a stable fastening force due to the desired suction force could not be obtained.

Japanese Patent Laid-Open No. 11-30248

The problem to be solved is that a press-formed burr remains on the clutch plate, and this burr abuts against the contact surface of the rotor or armature to create a gap between the clutch plate and the rotor or armature. There is a possibility that a stable fastening force due to the suction force cannot be obtained.

  In order to suppress a gap caused by burrs between the clutch plate and the rotor or armature, the present invention is arranged between the rotor and the armature that are arranged opposite to each other in the rotation axis direction, and the outer An inner plate that is rotationally engaged with the plate and the inner rotating member, and the outer plate and the inner plate have a through hole that forms a non-magnetic portion in a radially intermediate portion, and is disposed between the rotor and the armature. In an electromagnetic clutch that forms a magnetic path through the through hole and fastens the outer plate and the inner plate between the rotor and the armature, the outer plate or the inner adjacent to at least one of the rotor or the armature・ The most important thing is to provide a relief to avoid contact of the through-holes of the plate or the edges of the inner and outer circumferences. The main feature.

  The present invention includes an outer plate that is alternately arranged between a rotor and an armature that are arranged to face each other in the direction of the rotation axis and that is rotationally engaged with an outer rotating member, and an inner plate that is rotationally engaged with an inner rotating member. The plate and the inner plate have a through hole that forms a non-magnetic portion in a radially intermediate portion, and a magnetic path is formed between the rotor and the armature via the through hole to form the outer plate and the inner plate. In an electromagnetic clutch for fastening a plate between the rotor and the armature, an escape portion that avoids contact of the through hole or the inner and outer peripheral edges of the outer plate or the inner plate adjacent to at least one of the rotor or the armature Due to the burr between the outer plate or inner plate and the rotor or armature Suppressed while, it is possible to obtain a stable fastening force by desired suction force.

The purpose of suppressing the gap caused by burrs between the clutch plate and the rotor or armature is realized by providing a relief.

  FIG. 1 is a cross-sectional view showing an electromagnetic friction clutch to which Embodiment 1 of the present invention is applied.

  As shown in FIG. 1, the electromagnetic friction clutch 1 includes a clutch housing 3 and a shaft 5. The clutch housing 3 constitutes an outer rotating member.

  The clutch housing 3 is provided with an inner spline 7, and an internal thread portion 9 is formed on the inner periphery of the end portion. A rotor 11 is coupled to the female thread portion 9 of the clutch housing 3 by screwing, and is prevented from loosening by a nut 13. A seal 15 such as an O-ring is supported on the outer periphery of the rotor 11 and is in close contact with the inner peripheral surface of the clutch housing 3. The rotor 11 is integrally provided with a nonmagnetic portion 17 in a circular shape.

  The shaft 5 is formed in a hollow shape, and a partition wall 19 is provided at an intermediate portion. The shaft 5 is provided with a spline 21 on the clutch housing 3 side with a partition wall 19 interposed therebetween. The shaft 5 is provided with an oil hole 22 penetrating from the inner peripheral side to the spline 21. The shaft 5 is provided with an inner spline 23 on the rotor 11 side with the partition wall 19 in between. The shaft 5 is rotatably supported on the clutch housing 3 side by a bearing 25 and is rotatably supported on the rotor 11 side by a needle bearing 27. A seal 29 supported on the rotor 11 side is in close contact with the outer peripheral surface of the shaft 5.

  A main clutch 31, a pilot clutch 33, a cam plate 35, a pressing plate 37, and an armature 39 are disposed between the clutch housing 3 and the shaft 5.

  The main clutch 31 includes a plurality of inner plates 41 and outer plates 43, and the plates 41 and 43 are alternately arranged. The inner plate 41 is in spline engagement with the spline 21 of the shaft 5. The outer plate 43 is spline-engaged with the inner spline 7 of the clutch housing 3. The main clutch 31 is fastened by pressing of the pressing plate 37 and transmits torque between the clutch housing 3 and the shaft 5. The pressing plate 37 is spline-engaged with the spline 21 of the shaft 5.

  The pilot clutch 33 is interposed between the armature 39 and the rotor 11 and includes a plurality of inner plates 45 and outer plates 47 as clutch plates, and both plates 45 and 47 are alternately arranged. The inner plate 45 is rotationally engaged by the spline engagement with the outer peripheral surface of the cam plate 35 which is an inner rotating member, and the outer plate 47 is rotationally engaged by the spline engagement with the inner spline 7 of the clutch housing 3. Match.

  The armature 39 is spline-engaged with the inner spline 7 of the clutch housing 3. The armature 39 is attracted by the magnetic force of an electromagnet, which will be described later, and moves to the rotor 11 side so as to fasten the pilot clutch 33.

  The back side of the cam plate 35 is configured to abut on the rotor 11 side via a needle bearing 49. A cam mechanism 53 having a ball 51 is provided between the cam plate 35 and the pressing plate 37.

  2 (a) is a front view of the inner plate 45 of the pilot clutch 33, FIG. 2 (b) is a sectional view of the main part showing the depth of the groove, and FIG. 3 (a) is the pilot clutch. 33 is a front view of the outer plate 47 of FIG. 3, and FIG. 3B is a cross-sectional view of the main part showing the depth of the groove.

  Referring also to FIGS. 2A and 2B, a plurality of intersecting grooves 55 are formed on the friction engagement surface of the inner plate 45. The groove 55 is called a so-called sunburst groove, and is formed to have a depth d1 = 100 μm or more, and is arranged so that a plurality of curves intersect in a lattice pattern. A plurality of through-holes 57 constituting a non-magnetic portion are connected in an arc shape in the circumferential portion of the inner plate 45 in the radial direction.

  Referring also to FIGS. 3 (a) and 3 (b), the circumferentially spiral fine groove 59 is formed on the friction engagement surface of the outer plate 47. The fine groove 59 is formed to a depth d2 = 50 μm or less when the outer plate 47 is press-molded. The friction engagement surface of the outer plate 47 is not polished to leave the fine groove 59. A plurality of through-holes 61 constituting a nonmagnetic portion are connected to the intermediate portion in the radial direction of the outer plate 47 in an arc shape in the circumferential direction.

  The friction engagement surface of the outer plate 47 provided with the fine grooves 59 is in contact with the contact surfaces 63 and 65 of the rotor 11 and the armature 39 so as to face each other. The inner plate 45 having the groove 55 (sunburst groove) is interposed between the outer plates 47. Such an arrangement of the outer plate 47 and the inner plate 45 is an arrangement in which the inner plate 45 having the groove 55 (sunburst groove) is in contact with the contact surfaces 63 and 65 of the rotor 11 and the armature 39. It has been confirmed by an experiment by the applicant of the present application that the transmission torque is improved by the same energization compared to the above.

FIG. 4 is an enlarged cross-sectional view around the pilot clutch 33.
As shown in FIG. 4, the rotor 11 and the armature 39 are provided with a circular recess 73, as an escape portion for avoiding contact between the through hole 61 of the adjacent outer plate 47 and the inner and outer peripheral edges 67, 69, 71. 75 and circular meat removing portions 77, 79, 81 are provided.
The recesses 73 and 75 are opposed to the through hole 61 and have a radial width larger than the width of the through hole 61. The meat removing portion 77 is formed with a chamfered slope, and the meat removing portions 79 and 81 are formed with curved surfaces.

  As shown in FIG. 1, an electromagnet 83 is disposed behind the rotor 11. The electromagnet 83 generates an electromagnetic force corresponding to the current control, and is fixed to the support body 85. The support body 85 is supported on the rotor 11 side outer periphery via a bearing 87 so as to be relatively rotatable. The support body 85 is engaged with the fixed side of the vehicle body in a non-rotatable manner. The electromagnet 83 is electrically connected to the power source and controller on the vehicle body side via a harness.

  By controlling energization to the electromagnet 83, a magnetic path is formed between the rotor 11, the support body 85, and the armature 39. In this case, there is no leakage of magnetic flux between the rotor 11 side and the armature 39 side by the nonmagnetic portion 17 and the through holes 57 and 61, and a magnetic path can be accurately formed.

  Due to the formation of the magnetic path, the armature 39 is attracted to the rotor 11 side, and the pilot clutch 33 is fastened. By this fastening, the cam plate 35 is engaged with the clutch housing 3 in the rotational direction. The pressing plate 37 engaged with the shaft 5 side rotates relative to the cam plate 35, and the cam mechanism 53 works to generate thrust. This thrust is transmitted to the rotor 11 side via the needle bearing 49 and acts on the pressing plate 37 as a reaction force. Due to the reaction force, the pressing plate 37 moves and the main clutch 31 is fastened. The main clutch 31 transmits torque from the clutch housing 3 to the shaft 5 according to the fastening force.

  In this case, even if burrs at the time of manufacture remain on the edge 67 of the through hole 61 of the outer plate 47 and the inner and outer peripheral edges 69 and 71, the recesses 73 and 75 escape the burrs for the edge 67, For the edge portions 69 and 71, the meat removal portions 77, 79, and 81 escape the burr.

  For this reason, the formation of a gap between the outer plate 47 and the contact surfaces 63 and 65 of the rotor 11 and the armature 39 is suppressed, the magnetic path is efficiently formed, and stable due to the desired attractive force. The obtained fastening force can be obtained.

  The burrs of the outer plate 47 remain by not polishing the friction engagement surface of the outer plate 47 having the fine grooves 59, but are similarly effective when burrs remain for other reasons. is there.

[Effect of Example 1]
In the first embodiment of the present invention, the outer plate 47 and the arm plate 39 that are alternately arranged between the rotor 11 and the armature 39 that are opposed to each other in the rotation axis direction are rotationally engaged with the clutch housing 3, and the inner is rotationally engaged with the cam plate 35. A plate 45 is provided, and the outer plate 47 and the inner plate 45 have through holes 57 and 61 that form a nonmagnetic portion in the middle portion in the radial direction, and the through hole is interposed between the rotor 11 and the armature 39. In the electromagnetic friction clutch 1 that forms a magnetic path through the holes 57 and 61 and fastens the outer plate 47 and the inner plate 45 between the rotor 11 and the armature 39, the rotor 11 and the armature 39 are adjacent to each other. Relief portion for avoiding contact between the through hole 61 of the outer plate 47 and the inner and outer peripheral edges 69 and 71 Since the circular recesses 73 and 75 and the circular meat removal portions 77, 79, and 81 are provided, the gap due to the burr between the outer plate 47 or the inner plate 45 and the rotor 11 or the armature 39 is suppressed. In addition, a stable fastening force due to the desired suction force can be obtained.

The outer plate 47 adjacent to the rotor 11 is provided with fine grooves 59 that are press-molded and not polished, so that the inner plate 45 provided with grooves 55 (sunburst grooves) serves as the contact surfaces 63 of the rotor 11 and the armature 39. The transmission torque can be improved by the same energization as compared with the arrangement in which it is opposed to 65.
The escape portion is formed on the contact surfaces 63 and 65 where the rotor 11 or the armature 39 contacts the adjacent outer plate, and the circular recesses 73 and 75 facing the through-hole 61 or the inner and outer peripheral edges. Since the circumferential meat removing portions 77, 79, 81 opposed to 69, 71 can be reduced in weight.
The outer plate 47 is fastened as the pilot clutch 33 that causes fastening of the main clutch 31 that controls torque transmission, and can efficiently generate pilot torque.
[Others]
It is also possible to selectively omit any one of the concave portion 75 or the meat removing portion 81 of the armature 39 and the concave portion 73 or the meat removing portions 77 and 79 of the rotor 11.

  When the inner plate 45 abuts against the contact surfaces 63 and 65 of the rotor 11 and the armature 39, the same effect is obtained when burrs remain on the inner plate 45.

  In addition, the outer plate (or inner plate) provided with fine grooves may be a flat outer plate (or inner plate) that can be substituted. In this case, the flat shape does not form grooves but is the surface. Is defined as having a roughness with an uneven shape of 50 μm or less. The roughness of the concavo-convex shape may be naturally formed when a press plate is punched, or may be intentionally formed such as processing or etching.

(Example 1) which is sectional drawing of an electromagnetic friction clutch. (A) is a front view of the inner plate of a pilot clutch, (b) is principal part sectional drawing which shows the depth of a groove | channel (Example 1). (A) is a front view of the outer plate of a pilot clutch, (b) is principal part sectional drawing which shows the depth of a groove | channel (Example 1). (Example 1) which is an expanded sectional view around a pilot clutch.

Explanation of symbols

1 Electromagnetic friction clutch 3 Clutch housing (outside rotating member)
11 Rotor 31 Main clutch 33 Pilot clutch 35 Cam plate (inner rotating member)
39 Armature 45 Inner plate 47 Outer plate 57, 61 Through hole 59 Fine groove 73, 75 Recessed part (relief part)
77, 79, 81 Meat removal part (relief part)

Claims (4)

An outer plate that is alternately arranged between a rotor and an armature that are arranged opposite to each other in the rotation axis direction, and an outer plate that rotates and engages with an outer rotating member; and an inner plate that rotates and engages with an inner rotating member;
The outer plate and the inner plate have a through hole that forms a non-magnetic portion in a radially intermediate portion,
In an electromagnetic clutch that forms a magnetic path between the rotor and the armature via the through hole and fastens the outer plate and the inner plate between the rotor and the armature,
At least one of the rotor or the armature is provided with a relief portion that avoids contact of the through hole or inner and outer peripheral edges of the adjacent outer plate or inner plate,
An electromagnetic friction clutch characterized by that. The electromagnetic friction clutch according to claim 1,
The outer plate or inner plate adjacent to at least one of the rotor or armature is provided with fine grooves that are press-molded and not polished,
An electromagnetic friction clutch characterized by that. The electromagnetic friction clutch according to claim 1 or 2,
The escape portion is formed on a contact surface where the rotor or armature contacts the adjacent outer plate or inner plate, and a circular recess facing the through-hole or an edge facing the inner and outer peripheral edges. It is a shaped meat removal part,
An electromagnetic friction clutch characterized by that. The electromagnetic friction clutch according to any one of claims 1 to 3,
The outer plate or the inner plate is fastened as a pilot clutch that causes fastening of the main clutch that controls torque transmission.
An electromagnetic friction clutch characterized by that.

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