JP2016056861A - Electromagnetic clutch device - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide an electromagnetic clutch device capable of improving an effect of reducing a dragging torque.SOLUTION: An electromagnetic clutch device 1 comprises a housing 2; a clutch part 3 capable of engaging or disengaging a shaft 10 arranged to be rotatable in respect to the housing 2 and the housing 2; and electromagnetic coil 4 for generating electromagnetic force acting the clutch part 3. The clutch part 3 includes a plurality of outer clutch plates 31 connected to the housing 2 in a relative non-rotatable manner, an inner clutch plate 32 arranged between the plurality of outer clutch plates 31, a disc spring 34 made of resilient material for spacing-apart the outer clutch plates 31. The inner clutch plate 32 is made flat while being held between a plurality of outer clutch plates 31 and has a resiliency where its contact area with the outer clutch plates 31 is increased.SELECTED DRAWING: Figure 2

Description

  The present invention relates to an electromagnetic clutch device that operates by a magnetic force generated by energization of an electromagnetic coil.

  2. Description of the Related Art Conventionally, an electromagnetic clutch device that operates by energizing an electromagnetic coil and generates a frictional force between clutch plates is used as a driving force transmission device that transmits a driving force of a driving source of a vehicle, for example. Some electromagnetic clutch devices of this type have a configuration for reducing drag torque between clutch plates in an inoperative state (see, for example, Patent Document 1).

  An electromagnetic clutch device described in Patent Document 1 includes a housing and a hub as a pair of relative rotation members, a main clutch mechanism disposed between the housing and the hub, and a cam mechanism that applies a fastening force to the main clutch mechanism. And a multi-plate pilot clutch mechanism that generates cam thrust in the cam mechanism, and an electromagnetic coil that generates magnetic force for controlling the fastening force of the pilot clutch mechanism.

  The pilot clutch mechanism has a plurality (three) of outer clutch plates connected to the housing so as not to rotate relative to each other, and a plurality (two) of inner clutch plates disposed between the plurality of outer clutch plates. The frictional sliding between the outer clutch plate and the inner clutch plate is lubricated by the lubricating oil (oil) enclosed in the housing. Between the plurality of inner clutch plates, an elastic body is disposed as a separating unit that separates the inner clutch plates and reduces drag torque due to the viscosity of the lubricating oil.

JP 2008-38958 A

  If the separating means is arranged between the plurality of inner clutch plates as in the electromagnetic clutch device described in Patent Document 1, the interval between the adjacent inner clutch plates is widened, and the drag torque is reduced. However, if the outer clutch plate comes into close contact with one of the two inner clutch plates that sandwich the separating means due to the viscosity of the lubricating oil, the drag torque reduction effect may not be sufficiently exhibited.

  This invention is made | formed in view of said situation, and it aims at providing the electromagnetic clutch apparatus which can raise the reduction effect of drag torque more.

  A housing member in which a housing space is formed, a rotating member that is housed in the housing space and is disposed so as to be relatively rotatable with respect to the housing member, and a clutch portion that removably couples the housing member; An electromagnetic coil that generates an electromagnetic force that operates the clutch portion, and the clutch portion constitutes a magnetic path of magnetic flux generated by energization of the electromagnetic coil, and one of the housing member and the rotating member Between the plurality of friction members and the other of the housing member and the rotation member so as to be relatively non-rotatable and axially movable. A clutch plate and a spacing member that is disposed between the plurality of friction members and is made of an elastic body that separates the friction members from each other. Chipureto, said plurality of contact area between the plurality of friction members is flattened by being sandwiched between the friction member has an elasticity increases, the electromagnetic clutch device.

  According to the electromagnetic clutch device of the present invention, it is possible to increase the drag torque reduction effect.

1 is a front half sectional view showing an electromagnetic clutch device according to a first embodiment of the present invention. It is a front half sectional view showing the non-operation state of the electromagnetic clutch device with which the shaft etc. were assembled. It is a front half sectional view showing the operating state of the electromagnetic clutch device assembled with a shaft and the like. (A) is a top view which shows an outer clutch plate, (b) is a top view which shows an inner clutch plate. It is a front half sectional view showing an electromagnetic clutch device concerning a 2nd embodiment of the present invention. It is a front half sectional view showing an electromagnetic clutch device concerning a 3rd embodiment of the present invention. It is sectional drawing which shows the electromagnetic clutch apparatus which concerns on the 4th Embodiment of this invention. It is the elements on larger scale of FIG.

[First Embodiment]
Hereinafter, an electromagnetic clutch device according to a first embodiment of the present invention will be described with reference to FIGS. 1 to 4.

  FIG. 1 is a front half sectional view showing an electromagnetic clutch device 1 according to the present embodiment. 2 and 3 are front half sectional views showing a state in which the shaft 10 or the like as a rotating member is assembled to the electromagnetic clutch device 1, FIG. 2 shows a non-operating state, and FIG. 3 shows an operating state, respectively. . 1 to 3 show the upper half of the cross section of the electromagnetic clutch device 1 along the rotation axis O. FIG. In the following description, a direction parallel to the rotation axis O may be simply referred to as an axial direction.

  The electromagnetic clutch device 1 includes a housing 2 in which an accommodation space 2a is formed, a clutch portion 3 that is accommodated in the accommodation space 2a and that removably connects the shaft 10 and the housing 2, and operates the clutch portion 3. And an electromagnetic coil 4 for generating electromagnetic force. The clutch unit 3 includes a magnetic path forming member 30 that forms a magnetic path of magnetic flux generated by energization of the electromagnetic coil 4, and a plurality of outer clutch plates that are connected to the housing 2 so as to be axially movable and relatively non-rotatable. 31, an inner clutch plate 32 that is axially movable with respect to the shaft 10 and is relatively non-rotatable, an armature 33 that is attracted toward the magnetic path forming member 30 when the electromagnetic coil 4 is energized, and a plurality of outer clutches The disc spring 34 is disposed between the plates 31 and serves as a separating member that separates the outer clutch plates 31 in the axial direction.

  The electromagnetic clutch device 1 operates by energizing the electromagnetic coil 4, and suppresses differential rotation between the housing 2 and the shaft 10 by a frictional force generated between the outer clutch plate 31 and the inner clutch plate 32. The outer clutch plate 31 is an aspect of the “friction member” of the present invention, and the inner clutch plate 32 is an aspect of the “clutch plate” of the present invention disposed between a plurality of friction members.

  The housing 2 is made of, for example, nonmagnetic metal such as aluminum, and integrally includes a cylindrical cylindrical portion 20 and a flange portion 21 erected outward from the outer peripheral surface of the cylindrical portion 20. The flange portion 21 is formed with a bolt insertion hole 21a for attaching the electromagnetic clutch device 1 to a support member such as a vehicle body. The cylindrical portion 20 has a large diameter cylindrical portion 201 and a small diameter cylindrical portion 202 having different inner diameters, and the large diameter cylindrical portion 201 and the small diameter cylindrical portion 202 are arranged in parallel in the axial direction.

  A spline engaging portion 201 a made up of a plurality of spline protrusions extending in the axial direction is formed on the inner peripheral portion of the large diameter cylindrical portion 201. Inside the small diameter cylindrical portion 202, the magnetic path forming member 30 is fixed by press-fitting, for example. The magnetic path forming member 30 includes a first annular member 301, a second annular member 302 disposed inside the first annular member 301, and a third annular member 303 disposed inside the second annular member 302. Have. The first annular member 301 is fitted into the small diameter cylindrical portion 202, and an O-ring 203 is disposed between the inner peripheral surface of the small diameter cylindrical portion 202 and the outer peripheral surface of the first annular member 301.

  The first annular member 301 and the third annular member 303 are magnetic bodies made of, for example, iron-based metal, and the second annular member 302 is a non-magnetic body made of, for example, austenitic stainless steel. The second annular member 302, the first annular member 301, and the third annular member 303 are joined by welding at one axial end portion of the magnetic path forming member 30.

  The electromagnetic coil 4 has a winding 40 made of enameled wire and a holding member 41 made of a resin that accommodates the winding 40. The holding member 41 is annular, and a protrusion 411 protruding in the axial direction is formed at one place in the circumferential direction. The sheath 42 and the electric wire 43 accommodated in the sheath 42 are led out from the axial end surface of the projection 411, and the current output from the control device (not shown) is supplied to the winding 40 via the electric wire 43.

  The winding 40 of the electromagnetic coil 4 is accommodated in an annular space 30 a formed between the first annular member 301 and the third annular member 303. The annular space 30a is opened in the axial direction, and the opening is closed by a lid member 35 made of a magnetic material such as iron-based metal. An insertion hole 351 for inserting the protrusion 411 of the holding member 41 is formed in the lid member 35, and an O-ring 36 is disposed between the outer peripheral surface of the protrusion 411 and the inner peripheral surface of the insertion hole 351. Yes.

  The shaft 10 integrally includes a large diameter portion 101 facing the large diameter cylindrical portion 201 of the housing 2 and a small diameter portion 102 facing the third annular member 303 of the magnetic path forming member 30. A spline engaging portion 101a including a plurality of spline protrusions extending in the axial direction is formed on the outer peripheral portion. The bearing 11 and the seal member 12 are disposed between the outer peripheral surface of the small diameter portion 102 and the inner peripheral surface of the third annular member 303.

  The shaft 10 is supported by the bearing 11 and is disposed so as to be rotatable relative to the housing 2. The bearing 11 can roll between the outer ring 111 fitted inside the third annular member 303, the inner ring 112 fitted outside the small diameter portion 102 of the shaft 10, and the outer ring 111 and the inner ring 112. It has a plurality of rolling elements 113 arranged. A stepped portion 103 formed at the end of the small diameter portion 102 of the shaft 10 on the large diameter portion 101 side is abutted against the inner ring 112. In the present embodiment, the rolling elements 113 are spherical and the plurality of rolling elements 113 are held at equal intervals by a retainer (not shown). However, the present invention is not limited to this, and the rolling elements 113 are, for example, cylindrical. Also good.

  FIG. 4A is a plan view showing the outer clutch plate 31, and FIG. 4B is a plan view showing the inner clutch plate 32. The outer clutch plates 31 and the inner clutch plates 32 are alternately arranged along the axial direction, and the frictional sliding is lubricated by the lubricating oil sealed in the housing space 2 a of the housing 2. This lubricating oil is enclosed in the housing 2 by O-rings 203 and 36 and the seal member 12.

  The outer clutch plate 31 has a flat annular plate shape made of a magnetic material such as an iron-based metal, and a plurality of fine grooves 310 centering on the rotation axis O are formed on the sliding contact surface 31a that slides with the inner clutch plate 32. Are formed concentrically. An interval between adjacent fine grooves 310 is, for example, 15 to 45 μm, and a depth of the fine groove 310 is, for example, 10 to 30 μm.

  A plurality of engaging protrusions 311 are formed at the outer peripheral end of the outer clutch plate 31. The plurality of engaging protrusions 311 engage with the spline engaging portion 201 a in the large diameter cylindrical portion 201 of the housing 2. The outer clutch plate 31 is formed with a plurality of (six in the present embodiment) arc grooves 312 extending along the circumferential direction.

  The inner clutch plate 32 has an annular plate shape made of a magnetic material such as an iron-based metal like the outer clutch plate 31, but the sliding contact surface 32 a that slides with the outer clutch plate 31 is not flat and has a wave shape in the circumferential direction. Is curved. More specifically, the inner clutch plate 32 has three convex portions 32b that bulge toward the front side when viewed from the magnetic path forming member 30 side, and a rear side (armature 33 side). Three recessed portions 32c are formed alternately.

  A plurality of engaging protrusions 321 are formed at the inner peripheral end of the inner clutch plate 32. The plurality of engaging protrusions 321 engage with the spline engaging portion 101 a in the large diameter portion 101 of the shaft 10. Further, the inner clutch plate 32 is formed with a plurality of (six in this embodiment) arc grooves 322 extending along the circumferential direction. The plurality of arc grooves 322, coupled with the plurality of arc grooves 312 of the outer clutch plate 31, suppresses a short circuit of magnetic flux generated by energization of the electromagnetic coil 4.

  A plurality of oil grooves 320 through which lubricating oil flows are formed in a lattice shape on the sliding contact surface 32 a of the inner clutch plate 32. The oil groove 320 is deeper than the fine groove 310 of the outer clutch plate 31, and the interval between the adjacent oil grooves 320 is also wider than the interval between the fine grooves 310. The oil groove 320 is formed on both surfaces of the inner clutch plate 32.

  The armature 33 is an annular plate member made of a magnetic material such as iron-based metal, and is disposed at a position where the outer clutch plate 31 and the inner clutch plate 32 are sandwiched between the armature 33 and the magnetic path forming member 30. A plurality of engaging protrusions 331 that engage with the spline engaging portion 201 a in the large-diameter cylindrical portion 201 of the housing 2 are formed at the outer peripheral end of the armature 33. The plurality of engaging protrusions 331 engage with the spline engaging portion 201 a of the housing 2, so that the armature 33 is connected to the housing 2 so as to be axially movable and not relatively rotatable.

  Further, the axial movement of the armature 33 in the direction away from the magnetic path forming member 30 is restricted by a snap ring 22 as a stop member fitted to the end of the spline engaging portion 201 a of the housing 2. A recess 330 that is recessed in the axial direction is formed on the outer periphery of the armature 33, and when the armature 33 contacts the snap ring 22, the snap ring 22 is accommodated in the recess 330. Thereby, thickness reduction of the axial direction of the electromagnetic clutch apparatus 1 is achieved.

  The disc spring 34 is a plate-like elastic body made of metal such as spring steel, for example, and is disposed between the two outer clutch plates 31 and on the outer side of the inner clutch plate 32. The disc spring 34 is a magnetic body having a magnetic permeability that allows a magnetic flux to pass between the two outer clutch plates 31.

  Of the two outer clutch plates 31 sandwiching the disc spring 34, the outer clutch plate 31 on the magnetic path forming member 30 side is the first outer clutch plate 31A, and the outer clutch plate 31 on the armature 33 side is the second outer clutch. When the plate 31B is used, the inner peripheral end of the disc spring 34 is always in contact with the first outer clutch plate 31A regardless of the position of the armature 33 in the axial direction, and the outer peripheral end of the disc spring 34 is the second outer clutch. Always in contact with the plate 31B.

  In addition, the plate thickness of the disc spring 34 is made thinner than the plate thickness of the inner clutch plate 32. The disc spring 34 has a thickness (plate thickness) of 0.5 mm, for example, and the inner clutch plate 32 has a thickness (plate thickness) of 1.0 mm, for example. The thickness of the outer clutch plate 31 is equal to the thickness of the inner clutch plate 32.

  When the winding 40 of the electromagnetic coil 4 is energized, as shown in FIG. 3, the outer periphery of the first annular member 301, the outer clutch plate 31, the inner clutch plate 32, the armature 33, the outer clutch plate 31, and the inner clutch plate. Magnetic flux is generated in the magnetic path Z that passes through the inner peripheral portion of 32, the third annular member 303, and the lid member 35. A part of the magnetic flux generated by energizing the electromagnetic coil 4 passes through the disc spring 34. That is, the first annular member 301 and the third annular member 303, the outer clutch plate 31, the inner clutch plate 32, the armature 33, the disc spring 34, and the lid member 35 of the magnetic path forming member 30 are energized to the electromagnetic coil 4. It constitutes the magnetic path of the generated magnetic flux.

  When the electromagnetic coil 4 is energized while the shaft 10 is rotating, the armature 33 is attracted to the magnetic path forming member 30 side by the magnetic force of the magnetic flux formed in the magnetic path Z, and the outer clutch plate 31 and the inner clutch plate 32 are moved. Press in the axial direction. As a result, the sliding contact surface 31a of the outer clutch plate 31 and the sliding contact surface 32a of the inner clutch plate 32 are frictionally slid, and the frictional force generated between the outer clutch plate 31 and the inner clutch plate 32 causes friction of the shaft 10. The rotation is braked. That is, in the present embodiment, the electromagnetic clutch device 1 functions as an electromagnetic brake.

When the energization of the electromagnetic coil 4 is interrupted, the two outer clutch plates 31 (the first outer clutch plate 31A and the second outer clutch plate 31B) are caused by the elastic force (restoring force) of the disc spring 34. The armature 33 comes into contact with the snap ring 22 along with the separation. As shown in FIG. 1, when the electromagnetic coil 4 is not energized, the distance (D ₁ ) between the two outer clutch plates 31 separated by the disc spring 34 is the axial length of the inner clutch plate 32 alone ( Free length: wider than L ₁ ). Here, the single axial length of the inner clutch plate 32 refers to the axial length of the inner clutch plate 32 in a state where no external force is applied to the inner clutch plate 32, and more specifically, the convex portion 32b. Is the axial distance between the sliding contact surface 32a on the first outer clutch plate 31A side and the sliding contact surface 32a on the second outer clutch plate 31B side in the recess 32c.

  When the electromagnetic coil 4 is energized, the inner clutch plate 32 is flattened by receiving the pressing force from the armature 33, and the contact area with the outer clutch plate 31 increases. That is, the inner clutch plate 32 is flattened by being sandwiched between the two outer clutch plates 31, and has an elasticity that increases the contact area with the outer clutch plate 31.

  In the present embodiment, as shown in FIG. 3, the inner clutch plate 32 is flat when the electromagnetic coil 4 is energized, and the front and back sliding contact surfaces 32a are in contact with the sliding contact surface 31a of the outer clutch plate 31 throughout. However, the present invention is not limited to this, and a slight gap is formed between the convex portion 32b and the second outer clutch plate 31B, and a small gap between the concave portion 32c and the first outer clutch plate 31A. The inner clutch plate 32 may be formed as formed.

  Further, when the electromagnetic coil 4 is not energized, the inner clutch plate 32 is positioned between the two outer clutch plates 31 by the dynamic pressure action of the lubricating oil acting on the inner clutch plate 32 as the shaft 10 rotates. The inner clutch plate 32 is not in contact with any of the two outer clutch plates 31. That is, a gap is formed between the convex portion 32b of the inner clutch plate 32 and the first outer clutch plate 31A, and a gap is also formed between the concave portion 32c of the inner clutch plate 32 and the second outer clutch plate 31B. Is formed, and the inner clutch plate 32 is not in contact with both outer clutch plates 31. As a result, the shaft 10 can freely rotate with respect to the housing 2 around the rotation axis O.

(Operation and effect of the first embodiment)
According to the electromagnetic clutch device 1 according to the first embodiment described above, the following operations and effects can be obtained.

(1) When the electromagnetic coil 4 is not energized, the outer clutch plates 31 are separated from each other by the disc spring 34, and the inner clutch plate 32 is curved, so that the inner clutch plate 32 is not curved but is flat. Compared to the above, it is possible to increase the drag torque reduction effect. That is, only by separating the outer clutch plates 31 from each other, either one of the two outer clutch plates 31 sandwiching the disc spring 34 by the viscosity of the lubricating oil (the first outer clutch plate 31A or the second outer clutch plate 31B). The inner clutch plate 32 may come into close contact with the inner clutch plate 32. In this case, the effect of reducing the drag torque is not sufficiently exhibited. However, in the present embodiment, the inner clutch plate 32 is curved. Even if the 32 convex portions 32b or the concave portions 32c come into contact with the first outer clutch plate 31A or the second outer clutch plate 31B, the contact area is small, and drag torque is suppressed. Further, since the inner clutch plate 32 is flattened by being sandwiched between the two outer clutch plates 31, and has an elasticity that increases the contact area with the outer clutch plate 31, the operation of the electromagnetic clutch device 1 is performed. Sometimes, the outer clutch plate 31 and the inner clutch plate 32 come into surface contact, and a frictional force that brakes the shaft 10 is secured.

(2) Since the inner clutch plate 32 is curved in a wave shape in the circumferential direction, the inner clutch plate 32 is positioned in the middle of the two outer clutch plates 31 by the dynamic pressure action of the lubricating oil. That is, the axial force that the inner clutch plate 32 receives from the lubricating oil at the convex portion 32 b and the axial force that is received from the lubricating oil at the concave portion 32 c balance, and the inner clutch plate 32 becomes 2 when the electromagnetic coil 4 is not energized. It is suppressed from being pressed against any one of the outer clutch plates 31.

(3) Since the disc spring 34 is made of a magnetic material, part of the magnetic flux passes through the disc spring 34 when energization to the electromagnetic coil 4 is started, and the armature 33 is easily attracted to the magnetic path forming member 30 side. That is, when energization to the electromagnetic coil 4 is started, the magnetic resistance between the outer clutch plate 31 and the inner clutch plate 32 is large, and a large magnetomotive force is required to draw the armature 33 toward the magnetic path forming member 30 side. In this embodiment, the magnetic resistance is reduced by the magnetic flux passing through the disc spring 34 at the start of energization of the electromagnetic coil 4, and the armature 33 can be drawn toward the magnetic path forming member 30 with a smaller magnetomotive force. . Thereby, the power consumption of the electromagnetic clutch device 1 can be reduced, and the time required for the transition from the non-operating state to the operating state can be shortened.

(4) The disc spring 34 is made of a plate-like metal and has a thickness smaller than that of the inner clutch plate 32. Therefore, the disc spring 34 and the inner spring 33 are pressed by the armature 33 that receives the magnetic force of the electromagnetic coil 4. When the clutch plate 32 is flattened, the surface contact between the inner clutch plate 32 and the outer clutch plate 31 is not hindered by the disc spring 34, and the friction contact can be made over a wide area.

(5) Since the distance (D ₁ ) between the outer clutch plates 31 separated by the elastic force of the disc spring 34 is wider than the axial length (L ₁ ) of the inner clutch plate 32 alone, When the current is not energized, the inner clutch plate 32 is not in contact with any of the two outer clutch plates 31. Thereby, drag torque is reliably reduced.

(6) Since the oil groove 320 formed in the curved inner clutch plate 32 is deeper than the fine groove 310 of the outer clutch plate 31, for example, the inner clutch plate 32 slides on the outer clutch plate 31 in the convex portion 32b and the concave portion 32c. Even if they come into contact with each other, the oil groove 320 does not disappear due to wear of the sliding contact surface 32a. In the state where the inner clutch plate 32 is in sliding contact with the outer clutch plate 31 in the convex portion 32b and the concave portion 32c, for example, a current that generates a braking force that does not completely stop the rotation of the shaft 10 is supplied to the electromagnetic coil 4. Can occur.

[Second Embodiment]
Next, a second embodiment of the present invention will be described.

  FIG. 5 is a front half sectional view showing an electromagnetic clutch device 1A according to the second embodiment of the present invention. In FIG. 5, constituent elements that are the same as those described in the first embodiment are given the same reference numerals, and redundant descriptions thereof are omitted.

  The electromagnetic clutch device 1A according to the present embodiment is configured similarly to the electromagnetic clutch device 1 according to the first embodiment except that the outer clutch plate 31 is not provided. In other words, the inner clutch plate 32 is disposed between the magnetic path forming member 30 and the armature 33, and is biased in a direction away from the magnetic path forming member 30 by the elastic force of the disc spring 34.

  When the electromagnetic coil 4 is energized while the shaft 10 is rotating, the armature 33 is attracted to the magnetic path forming member 30 side by the magnetic force, and the inner clutch plate 32 is in sliding contact with the armature 33 and the magnetic path forming member 30, and the inner clutch plate. The rotation of the shaft 10 is braked by the frictional force generated between the armature 32 and the armature 33 and the magnetic path forming member 30. That is, in the present embodiment, the armature 33 and the magnetic path forming member 30 correspond to the “friction member” of the present invention. In addition, it is desirable to perform the heat processing and film-forming process for improving abrasion resistance to the surface which opposes the inner clutch plate 32 in the armature 33 and the magnetic path formation member 30.

  Also with the electromagnetic clutch device 1A according to the present embodiment, the same operations and effects as the operations and effects described in the first embodiment can be obtained. Further, since the electromagnetic clutch device 1A does not have the outer clutch plate 31, it is possible to reduce the axial size and reduce the number of parts.

[Third Embodiment]
Next, a third embodiment of the present invention will be described.

  FIG. 6 is a front half sectional view showing an electromagnetic clutch device 1B according to a third embodiment of the present invention. In FIG. 6, constituent elements that are the same as those described in the first embodiment are given the same reference numerals, and redundant descriptions thereof are omitted.

  In the electromagnetic clutch device 1B, three outer clutch plates 31 and two inner clutch plates 32 are alternately arranged in the clutch portion 3. The two inner clutch plates 32 have a flat plate shape, and one outer clutch plate 31 sandwiched between the two inner clutch plates 32 is curved in a wave shape in the circumferential direction. That is, in this embodiment, the two inner clutch plates 32 correspond to the “friction member” of the present invention, and the one outer clutch plate 31 sandwiched between these inner clutch plates 32 is the “clutch” of the present invention. Corresponds to “plate”.

  A disc spring 34 is disposed between the two inner clutch plates 32 to separate the inner clutch plates 32 from each other. The disc spring 34 is made of a magnetic material as in the first embodiment, and allows part of the magnetic flux to pass when energization of the electromagnetic coil 4 is started.

  Of the three outer clutch plates 31, the two outer clutch plates 31 except for the one outer clutch plate 31 sandwiched between the two inner clutch plates 32 have a flat plate shape. Note that these two outer clutch plates 31 can be omitted. In this case, one inner clutch plate 32 of the two inner clutch plates 32 faces the magnetic path forming member 30, and the other inner clutch plate 32 faces the armature 33.

  The thickness (plate thickness) of the disc spring 34 is thinner than the thickness (plate thickness) of the outer clutch plate 31, and the interval between the inner clutch plates 32 separated by the disc spring 34 when the electromagnetic coil 4 is not energized is a wave shape. The curved outer clutch plate 31 is wider than the single axial length. When the electromagnetic coil 4 is energized, the outer clutch plate 31 curved in a wave shape is sandwiched between the two inner clutch plates 32 to be elastically deformed and flattened to increase the contact area with the inner clutch plate 32. .

  In the first embodiment, a plurality of fine grooves 310 are concentrically formed in the outer clutch plate 31 and a lattice-like oil groove 320 is formed in the inner clutch plate 32. In the present embodiment, Contrary to the first embodiment, a lattice-like oil groove is formed in the outer clutch plate 31, and a plurality of fine grooves are formed in the inner clutch plate 32.

  Also by the electromagnetic clutch device 1B according to the present embodiment, the same operations and effects as those described in the first embodiment can be obtained.

[Fourth Embodiment]
Next, a fourth embodiment of the present invention will be described.

  FIG. 7 is a cross-sectional view of an electromagnetic clutch device 1C according to the fourth embodiment of the present invention. FIG. 8 is a partially enlarged view of FIG.

  The electromagnetic clutch device 1 </ b> C is disposed between a housing 5 in which an accommodation space 5 a is formed, an inner shaft 6 that is coaxially supported with the housing 5 and supported so as to be relatively rotatable, and the housing 5 and the inner shaft 6. A main clutch mechanism 7, a cam mechanism 70 for applying an axial pressing force to the main clutch mechanism 7, a pilot clutch mechanism 8 for transmitting a torque for generating a cam thrust as a pressing force to the cam mechanism 70, and a pilot clutch And an electromagnetic coil 9 for generating a magnetic force for controlling the torque transmitted by the mechanism 8.

  The electromagnetic clutch 1 </ b> C is disposed, for example, between a propeller shaft of a four-wheel drive vehicle and a differential device, and transmits a driving force corresponding to an excitation current supplied to the electromagnetic coil 9. For example, a propeller shaft is connected to the housing 5, and a pinion gear shaft that is engaged with a ring gear fixed to a differential case of a differential device is connected to the inner shaft 6.

  The housing 5 includes a bottomed cylindrical front housing 51 made of a nonmagnetic material such as aluminum, and an annular rear housing 52 coupled to the front housing 51 so as to rotate integrally by screwing or the like. Lubricating oil (not shown) is sealed inside the housing 5. A spline engaging portion 51 a made up of a plurality of spline protrusions provided along the rotation axis O is formed on the inner peripheral portion of the front housing 51. The rear housing 52 includes a first annular member 521 made of a magnetic material coupled to the front housing 51, a second annular member 522 made of a non-magnetic material integrally joined to the inner peripheral side of the first annular member 521, and It consists of the 3rd annular member 523 which consists of a magnetic body couple | bonded with the inner peripheral side of the 2 annular member 522. FIG. The electromagnetic coil 9 is disposed in the annular space 52 a between the first annular member 521 and the third annular member 523.

  The inner shaft 6 is a cylindrical member supported on the inner peripheral side of the housing 5 by a ball bearing 61 and a slide bearing 62. A spline engaging portion 6 a made up of a plurality of spline protrusions provided along the rotation axis O is formed at a portion of the inner shaft 6 facing the spline engaging portion 51 a of the front housing 51. A plurality of spline engaging portions 6b for connecting a drive shaft such as a pinion gear shaft (not shown) so as not to rotate relative to each other are formed on the inner peripheral portion of the inner shaft 6.

  The main clutch mechanism 7 has a plurality of outer clutch plates 71 and a plurality of inner clutch plates 72 that are alternately arranged along the rotation axis O, and the friction of the outer clutch plate 71 and the inner clutch plate 72 causes friction of the housing 5. A rotational force is transmitted to the inner shaft 6. The outer clutch plate 71 has a plurality of protrusions 711 that engage with the spline engaging portion 51 a of the front housing 51, and is not rotatable relative to the front housing 51 and is movable in the axial direction. The inner clutch plate 72 has a plurality of protrusions 721 that engage with the spline engaging portion 6 a of the inner shaft 6, and is not rotatable relative to the inner shaft 6 and is movable in the axial direction.

  The cam mechanism 70 includes a pilot cam 701, a main cam 702 that presses the main clutch mechanism 7 in the axial direction, and a plurality of spherical cam balls 703 disposed between the pilot cam 701 and the main cam 702. ing. The main cam 702 has spline teeth 702 a formed on the inner peripheral surface thereof engaged with the spline engaging portion 6 a of the inner shaft 6, and relative rotation with the inner shaft 6 is restricted. A plurality of spline teeth 701 a are formed in parallel with the rotation axis O on the outer peripheral surface of the pilot cam 701. A thrust needle roller bearing 704 is disposed between the pilot cam 701 and the third annular member 523 of the rear housing 52.

  A plurality of cam grooves 701b and 702b whose axial depth varies along the circumferential direction are formed on the opposing surfaces of the pilot cam 701 and the main cam 702. The cam mechanism 70 generates an axial pressing force (cam thrust) that presses the main cam 702 against the main clutch mechanism 7 as the cam ball 703 rolls on the cam grooves 701 b and 702 b.

  The pilot clutch mechanism 8 includes a plurality of outer clutch plates 81 arranged alternately along the rotation axis O, an inner clutch plate 82 arranged between the plurality of outer clutch plates 81, and energization of the electromagnetic coil 9. The armature 83 that is attracted to the rear housing 52 side by the generated magnetic force and presses the outer clutch plate 81 and the inner clutch plate 82 in the axial direction and the plurality of outer clutch plates 81 are arranged. And a disc spring 84 as a spacing member that is spaced apart in the axial direction. The frictional sliding between the outer clutch plate 81 and the inner clutch plate 82 is lubricated by lubricating oil.

  The outer clutch plate 81 and the inner clutch plate 82 have an annular plate shape made of a magnetic material such as iron metal. In the present embodiment, the pilot clutch mechanism 8 has two outer clutch plates 81 and one inner clutch plate 82. However, the number of outer clutch plates 81 and inner clutch plates 82 depends on the number of pilot clutches. The mechanism 8 can be selected as appropriate according to the torque that needs to be transmitted.

  The two outer clutch plates 81 have a flat plate shape, and the inner clutch plate 82 is formed in a curved shape in the circumferential direction. Further, the inner clutch plate 82 is flattened by being sandwiched between the two outer clutch plates 81, and has an elasticity that increases the contact area with the outer clutch plate 81.

  The outer clutch plate 81 has a plurality of protrusions 811 that engage with the spline engaging portion 51 a of the front housing 51, and is not rotatable relative to the front housing 51 and is movable in the axial direction. The inner clutch plate 82 has a plurality of protrusions 821 that fit into a plurality of spline teeth 701 a formed on the pilot cam 701 of the cam mechanism 70, and is relatively non-rotatable and axially movable with respect to the pilot cam 701. . Further, similarly to the outer clutch plate 31 and the inner clutch plate 32 according to the first embodiment, a plurality of arc grooves 812 and 822 are formed in the outer clutch plate 81 and the inner clutch plate 82, respectively.

  The armature 83 is made of an annular magnetic body and is disposed so as to be movable in the axial direction at a position between the outer clutch plate 81 and the inner clutch plate 82. A plurality of protrusions 831 that engage with the spline engaging portion 51 a of the front housing 51 are provided on the outer peripheral portion of the armature 83. Thereby, the armature 83 is not rotatable relative to the front housing 51 and is movable in the axial direction.

  The disc spring 84 is a plate-like elastic body made of a metal such as spring steel, for example, and is disposed between the two outer clutch plates 81 and on the outer side of the inner clutch plate 82. The disc spring 84 is a magnetic body having a magnetic permeability that allows magnetic flux to pass between the two outer clutch plates 81, and the inner peripheral end of the disc spring 84 is formed by the two outer clutch plates 81. One outer clutch plate 81 is always in contact, and the outer peripheral end of the disc spring 84 is always in contact with the other outer clutch plate 81.

  The disc spring 84 is formed thinner than the inner clutch plate 82. Further, the interval between the two outer clutch plates 81 separated by the disc spring 84 when the electromagnetic coil 9 is not energized is wider than the axial length (free height) of the inner clutch plate 82 alone.

  In the present embodiment, the outer clutch plate 81 corresponds to the “friction member” of the present invention, and the inner clutch plate 82 corresponds to the “clutch plate” of the present invention. The pilot cam 701 corresponds to a “rotating member” of the present invention disposed so as to be rotatable relative to the housing 5. The plurality of outer clutch plates 81, inner clutch plates 82, and disc springs 84 constitute a clutch portion 80 that couples the housing 5 and the pilot cam 701 so as to be detachable.

  The electromagnetic coil 9 is held by a yoke 91 supported by the third annular member 523 of the rear housing 52 by a ball bearing 53. Excitation current is supplied to the electromagnetic coil 9 from a control device (not shown) via an electric wire 92.

  When an excitation current is supplied from the control device to the electromagnetic coil 9, the electromagnetic clutch device 1 </ b> B configured as described above has the yoke 91, the first annular member 521, the outer clutch plate 81, and the outer clutch plate 82. A magnetic flux is generated in the magnetic path Z passing through the armature 83, the inner periphery of the outer clutch plate 81 and the inner clutch plate 82, and the third annular member 523, and the armature 83 is attracted to the rear housing 52 side by the magnetic force of this magnetic flux. Thus, the outer clutch plate 81 and the inner clutch plate 82 are pressed.

  As a result, the outer clutch plate 81 and the inner clutch plate 82 frictionally slide, and the rotational force of the housing 5 is transmitted to the pilot cam 701 of the cam mechanism 70 via the pilot clutch mechanism 8, so that the pilot cam 701 is moved to the main cam 702. Relative rotation. Due to the relative rotation of the pilot cam 701 and the main cam 702, the cam ball 703 rolls on the cam grooves 701b and 702b, and axial thrust in the direction in which the pilot cam 701 and the main cam 702 are separated from each other is generated. The main clutch mechanism 7 is pressed by the main cam 702 by the thrust of the cam mechanism 70, and the driving force is transmitted from the housing 5 to the inner shaft 6 by friction between the plurality of outer clutch plates 71 and the plurality of inner clutch plates 72. .

  On the other hand, when the electromagnetic coil 9 is not energized, the outer clutch plates 81 are separated from each other by the elastic force of the disc spring 84, and a gap is formed between the inner clutch plate 82. As a result, drag torque in the pilot clutch mechanism 8 is suppressed, and consequently drag torque in the main clutch mechanism 7 is suppressed.

  Also according to the fourth embodiment described above, it is possible to obtain the same operations and effects as the operations and effects described in the first embodiment.

(Appendix)
As mentioned above, although this invention was demonstrated based on 1st thru | or 4th embodiment, embodiment described above does not limit the invention based on a claim. In addition, it should be noted that not all the combinations of features described in the embodiments are essential to the means for solving the problems of the invention.

  Further, the present invention can be appropriately modified and implemented without departing from the spirit of the present invention. For example, the clutch portion 80 of the electromagnetic clutch device 1C according to the fourth embodiment may be configured like the clutch portion 3 of the electromagnetic clutch devices 1B and 1C according to the second or third embodiment. Moreover, although the said 1st thru | or 4th embodiment demonstrated the case where the inner clutch plates 32 and 82 or the outer clutch plate 31 were curvedly formed in the circumferential direction, it is not restricted to this, For example, it may have a disc spring shape (conical shape without a bottom surface with a hole in the center), or a shape that is curved in a bow shape along the radial direction and the central portion in the radial direction bulges in the axial direction. There may be. Even in such a shape, drag torque can be reduced as long as it has elasticity that flattens by receiving an axial pressing force.

  In the first to fourth embodiments, the case where the disc spring 34 is used as the separation member of the present invention has been described. However, the invention is not limited to this, and a wave washer curved in a circumferential shape is used as the separation member. You may apply as Furthermore, an elastic body made of rubber or resin can be used as the separating member. However, it is desirable that the separating member is a magnetic body in order to increase the responsiveness when the electromagnetic clutch device shifts from the non-operating state to the operating state.

DESCRIPTION OF SYMBOLS 1,1A, 1B, 1C ... Electromagnetic clutch apparatus, 10 ... Shaft, 101 ... Large diameter part, 101a ... Spline engagement part, 102 ... Small diameter part, 103 ... Step part, 11 ... Bearing, 111 ... Outer ring, 112 ... Inner ring DESCRIPTION OF SYMBOLS 113 ... Rolling element, 12 ... Seal member, 2 ... Housing (housing member), 20 ... Cylindrical part, 201 ... Large diameter cylindrical part, 201a ... Spline engaging part, 202 ... Small diameter cylindrical part, 203 ... O-ring, 21 ... Flange part, 21a ... Bolt insertion hole, 22 ... Snap ring, 2a ... Accommodating space, 3 ... Clutch part, 30 ... Magnetic path forming member, 30a ... Annular space, 301 ... First annular member, 302 ... Second annular member , 303 ... third annular member, 31, 31A, 31B ... outer clutch plate, 310 ... fine groove, 311 ... engagement protrusion, 312 ... arc groove, 31a ... sliding contact surface, 32 ... inner clutch 320, oil groove, 321 ... engaging projection, 322 ... arc groove, 32a ... sliding contact surface, 32b ... convex portion, 32c ... concave portion, 33 ... armature, 330 ... concave portion, 331 ... engaging projection, 34 ... Belleville spring, 35 ... lid member, 351 ... insertion hole, 36 ... O-ring, 4 ... electromagnetic coil, 40 ... winding, 41 ... holding member, 411 ... projection, 42 ... sheath, 43 ... electric wire, 5 ... housing (Housing member), 51 ... front housing, 51a ... spline engaging portion, 52 ... rear housing, 52a ... annular space, 521 ... first annular member, 522 ... second annular member, 523 ... third annular member, 53, 61 ... ball bearing, 5a ... accommodating space, 6 ... inner shaft, 62 ... slide bearing, 6a, 6b ... spline engaging portion, 7 ... main clutch mechanism, 70 ... cam mechanism, 701 ... pilot cam, 701a ... spin Line teeth, 701b, 702b ... Cam groove, 702 ... Main cam, 702a ... Spline teeth, 703 ... Cam ball, 704 ... Thrust needle roller bearing, 71 ... Outer clutch plate, 711, 721, 811, 821, 831 ... Projection, 72 DESCRIPTION OF SYMBOLS ... Inner clutch plate, 8 ... Pilot clutch mechanism, 80 ... Clutch part, 81 ... Outer clutch plate, 812, 822 ... Arc groove, 82 ... Inner clutch plate, 83 ... Armature, 84 ... Disc spring, 9 ... Electromagnetic coil, 91 ... Yoke, 92 ... Electric wire, O ... Rotation axis, Z ... Magnetic path

Claims (5)

A housing member having a housing space formed therein;
A clutch member that is housed in the housing space and is detachably coupled to the housing member and a rotating member that is arranged to be rotatable relative to the housing member;
An electromagnetic coil that generates an electromagnetic force for operating the clutch unit,
The clutch part is
A plurality of friction members that constitute a magnetic path of magnetic flux generated by energization of the electromagnetic coil, and are connected to one of the housing member and the rotating member so as not to be relatively rotatable;
A clutch plate disposed between the plurality of friction members and disposed on the other member of the housing member and the rotating member so as not to be relatively rotatable and axially movable;
A separation member that is disposed between the plurality of friction members and made of an elastic body that separates the friction members;
The clutch plate has an elasticity that is flattened by being sandwiched between the plurality of friction members and increases a contact area with the plurality of friction members.
Electromagnetic clutch device. The clutch plate is formed in a wave shape in the circumferential direction,
The electromagnetic clutch device according to claim 1. The spacing member is made of a magnetic material that allows a part of magnetic flux generated by energization of the electromagnetic coil to pass through.
The electromagnetic clutch device according to claim 1 or 2. The spacing member is made of a plate-like metal, and the thickness thereof is thinner than the thickness of the clutch plate.
The electromagnetic clutch device according to any one of claims 1 to 3. The distance between the friction members separated by the separation member when the electromagnetic coil is not energized is wider than the axial length of the clutch plate alone,
The electromagnetic clutch device according to any one of claims 1 to 4.

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