JP2013096427A - Driving force transmitting device and method of designing the same - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide a driving force transmitting device which can make an electromagnetic clutch device function surely even though magnetic flux leaking from an armature to a protrusion of a moving cam member occurs.SOLUTION: The moving cam member 52 is formed to protrude on armature 43 side annularly and is provided with the protrusion 130 which regulates move to a direction opposed to yoke 41 side of the armature 43 by abutting against the armature 43. The protrusion 130 is provided with inner peripheral cylindrical surface 131, outer peripheral cylindrical surface 132, annular end face 133 capable of abutting against the armature 43, a tapered inner peripheral chamfering 134 which conects the inner peripheral cylindrical surface 131 to inner peripheral edge of the end face 133 and a tapered outer peripheral chamfering 135 which connects the outer peripheral cylindrical surface 132 to outer peripheral edge of the end face 133. Radial length Wb of the end face 133 is set to range from 1.3 mm to 2.0 mm.

Description

  The present invention relates to a driving force transmission device and a design method thereof.

  A driving force transmission device called a so-called electronically controlled coupling is disclosed in, for example, Japanese Patent Application Laid-Open No. 2010-96239 (Patent Document 1). This type of driving force transmission device is configured as follows. Torque corresponding to the rotation difference between the outer rotating member and the inner rotating member is transmitted to the cam mechanism via the pilot clutch of the electromagnetic clutch device, and the torque is converted into an axial pressing force against the main clutch by the cam mechanism and pressed. Torque is transmitted between the outer rotating member and the inner rotating member by the main clutch.

  In the electromagnetic clutch device, when the armature is drawn toward the yoke, torque is transmitted between the outer pilot clutch and the inner pilot clutch. A moving cam member constituting a cam mechanism is disposed on the opposite side of the armature in the axial direction of the yoke. Since the moving cam member is a torque transmission member, it is generally formed of a material mainly composed of iron. That is, the moving cam member is a magnetic material. Therefore, the magnetic flux passing through the armature may leak to the moving cam member side. If this leakage magnetic flux is large, when current is supplied to the coil of the electromagnetic clutch device, the armature may not be attracted to the yoke side but may be attracted to the moving cam member side.

  Therefore, as described in Patent Document 1, for example, a protrusion is formed on the armature side of the moving cam member in order to reduce the area in which the armature and the moving cam member can contact. Thereby, a space part can be formed in most between the axial directions of an armature and a movable cam member, and a leakage magnetic flux can be reduced.

JP 2010-96239 A

  However, depending on the shape of the projection on the armature side of the moving cam member, there is a possibility that it is magnetized by the leakage magnetic flux. In this case, the armature is attracted to the moving cam member, and there is a possibility that the armature cannot be drawn toward the yoke side due to the suction force of the armature toward the yoke side. Then, the electromagnetic clutch device does not function, and as a result, the driving force transmission device does not function.

  The present invention has been made in view of such circumstances, and an object of the present invention is to provide a driving force transmission device capable of reliably functioning an electromagnetic clutch device and a design method thereof.

  (Claim 1) A driving force transmission device according to the present invention includes a cylindrical outer rotating member, an axial inner rotating member coaxially disposed in the outer rotating member, and the outer rotating member. An electromagnetic clutch device including a main clutch for transmitting torque between the inner rotating member and the inner rotating member; a pilot clutch capable of transmitting the torque of the outer rotating member by attracting the armature by a magnetic force; and the main clutch and the pilot clutch. The phase difference between the rotation of the outer rotating member and the rotation of the inner rotating member transmitted through the pilot clutch is converted into a pressing force in the axial direction, and the moving cam member is moved in the axial direction. A cam mechanism that presses the main clutch by moving the lubricant, and lubricating oil filled between the outer rotating member and the inner rotating member. In the driving force transmission apparatus, the moving cam member is formed to project annularly on the armature side, and a protrusion that regulates movement of the armature in the direction opposite to the yoke side by contacting the armature The protrusion has an inner peripheral cylindrical surface, an outer peripheral cylindrical surface, an annular end surface capable of contacting the armature, and a tapered inner periphery connecting the inner peripheral cylindrical surface and the inner peripheral edge of the end surface. A chamfer and a tapered outer peripheral chamfer connecting the outer peripheral cylindrical surface and the outer peripheral edge of the end surface, and a radial length of the end surface is set in a range of 1.3 mm to 2.0 mm. Yes.

  (Claim 2) Preferably, the inner diameter of the inner peripheral cylindrical surface of the protrusion is set in a range of 92 mm to 112 mm, and the outer diameter of the outer peripheral cylindrical surface of the protrusion is 96 mm to 116 mm. Set to range.

  (Claim 3) The driving force transmission device designing method of the present invention includes a cylindrical outer rotating member, and an axial inner rotating member arranged coaxially so as to be relatively rotatable in the outer rotating member. An electromagnetic clutch device including a main clutch for transmitting torque between the outer rotating member and the inner rotating member, a pilot clutch capable of transmitting the torque of the outer rotating member by attracting an armature by magnetic force, and the main clutch Moved by converting the phase difference between the rotation of the outer rotating member and the rotation of the inner rotating member, which is provided between the clutch and the pilot clutch, and transmitted through the pilot clutch, to an axial pressing force. A cam mechanism that presses the main clutch by moving the cam member in the axial direction is filled between the outer rotating member and the inner rotating member. In the design method of the driving force transmission device comprising the lubricating oil, the moving cam member is formed to project annularly on the armature side, and comes into contact with the armature so that the armature is in a direction opposite to the yoke side A protrusion that restricts movement to the inner peripheral cylindrical surface; an outer peripheral cylindrical surface; an annular end surface that can contact the armature; and the inner peripheral cylindrical surface and an inner peripheral edge of the end surface And a tapered outer peripheral chamfer connecting the outer peripheral cylindrical surface and the outer peripheral edge of the end surface, and a radial length of the end surface is 1.3 mm or more. Designed in a range of 0 mm or less.

  (Aspect 1) The attractive force of the armature by the moving cam member magnetized by the leakage magnetic flux increases as the residual magnetic flux density increases. Therefore, by setting the radial length of the end face of the protrusion to 1.3 mm or more, the residual magnetic flux density between the protrusion and the armature can be sufficiently reduced, so that the armature is reliably attracted to the yoke side. can do. Further, when the radial length of the end face of the protrusion is increased, a large force is required to separate the armature from the protrusion due to the squeeze effect of the lubricating oil. Therefore, by making the length in the radial direction of the end face of the protruding portion 2.0 mm or less, the adsorption force due to the squeeze effect of the lubricating oil can be sufficiently reduced, so that the armature can be reliably sucked to the yoke side. it can. In other words, by setting the radial length of the end face of the protrusion in the range of 1.3 mm or more and 2.0 mm or less, the electromagnetic clutch device can be reliably functioned, and as a result, the driving force transmission device is also reliable. Can function.

  (Claim 2) In particular, when the inner diameter of the inner cylindrical surface of the protrusion is in the range of 92 mm to 112 mm and the outer diameter of the outer cylindrical surface of the protrusion is in the range of 96 mm to 116 mm, the protrusion By setting the radial length of the end face of the portion in the range of 1.3 mm or more and 2.0 mm or less, the electromagnetic clutch device can be made to function reliably.

  (Claim 3) According to the design method of the driving force transmission device according to the present invention, the radial length of the end face of the protrusion is designed in the range of 1.3 mm or more and 2.0 mm or less, thereby reliably As a result, it can also function reliably as a driving force transmission device.

It is an axial sectional view of the driving force transmission device of this embodiment. FIG. 2 is an axial sectional view of a moving cam member constituting the driving force transmission device of FIG. 1. FIG. 3 is an enlarged view of a part III in FIG. 2. FIG. 4 is a graph showing the relationship between the radial length of the end face of the protruding portion of the moving cam member shown in FIG. 3 and the attracting current for attracting the armature from the moving cam member side to the yoke side. 2 is a graph showing a relationship between an axial gap between an armature and a pilot clutch and an attracting current for attracting the armature from the moving cam member side to the yoke side between the projecting portion and the yoke shown in FIG.

(Overall configuration of driving force transmission device)
A driving force transmission device 1 according to the present embodiment will be described with reference to FIG. The driving force transmission device is applied to, for example, a driving force transmission system to the auxiliary driving wheels to which the driving force is transmitted according to the traveling state of the vehicle in a four-wheel drive vehicle. More specifically, in a four-wheel drive vehicle, the driving force transmission device 1 is connected, for example, between a propeller shaft to which engine driving force is transmitted and a rear differential. The driving force transmission device 1 transmits the driving force transmitted from the propeller shaft to the rear differential while changing the transmission ratio. This driving force transmission device 1 acts to reduce the rotation difference when, for example, a rotation difference between the front wheels and the rear wheels occurs.

  The driving force transmission device 1 includes a so-called electronic control coupling. As shown in FIG. 1, the driving force transmission device 1 includes an outer case 10 as an outer rotating member, an inner shaft 20 as an inner rotating member, a main clutch 30, and an electromagnetic clutch device 40 constituting a pilot clutch mechanism. And a cam mechanism 50.

  The outer case 10 is supported on the inner peripheral side of a cylindrical hole cover (not shown) so as to be rotatable with respect to the hole cover. The outer case 10 is formed in a cylindrical shape as a whole, and is formed by a front housing 11 disposed on the vehicle front side and a rear housing 12 disposed on the vehicle rear side.

  The front housing 11 is formed of, for example, an aluminum alloy made of a nonmagnetic material mainly composed of aluminum, and has a bottomed cylindrical shape. The outer peripheral surface of the cylindrical portion of the front housing 11 is rotatably supported on the inner peripheral surface of the hole cover via a bearing. Furthermore, the bottom of the front housing 11 is connected to the vehicle rear end side of a propeller shaft (not shown). That is, it arrange | positions so that the bottomed cylindrical opening side of the front housing 11 may face the vehicle rear side. A female spline 11a is formed in the axially central portion of the inner peripheral surface of the front housing 11, and a female screw is formed near the opening of the inner peripheral surface.

  The rear housing 12 is formed in an annular shape, and is disposed integrally with the front housing 11 on the radially inner side on the opening side of the front housing 11. An annular groove is formed on the vehicle rear side of the rear housing 12 over the entire circumference. A part of the bottom of the annular groove of the rear housing 12 is provided with an annular member 12a made of, for example, stainless steel as a nonmagnetic material. Parts of the rear housing 12 other than the annular member 12a are formed of a material mainly composed of iron, which is a magnetic material, to form a magnetic circuit (hereinafter referred to as “iron-based material”). A male screw is formed on the outer peripheral surface of the rear housing 12, and the male screw is screwed to the female screw of the front housing 11. The front housing 11 and the rear housing 12 are fixed by tightening the female screw of the front housing 11 to the male screw of the rear housing and bringing the end surface of the front side of the front housing 11 into contact with the end surface of the stepped portion of the rear housing.

  The inner shaft 20 is formed in an axial shape having a male spline 20a at the axially central portion of the outer peripheral surface. The inner shaft 20 passes through the central through hole of the rear housing 12 in a liquid-tight manner, and is coaxially disposed in the outer case 10 so as to be relatively rotatable. The inner shaft 20 is rotatably supported by the front housing 11 and the rear housing 12 via bearings in a state where the axial position is restricted with respect to the front housing 11 and the rear housing 12. Furthermore, the vehicle rear end side (the right side in FIG. 1) of the inner shaft 20 is connected to a differential gear (not shown). The space that is liquid-tightly partitioned by the outer case 10 and the inner shaft 20 is filled with lubricating oil at a predetermined filling rate.

  The main clutch 30 transmits torque between the outer case 10 and the inner shaft 20. The main clutch 30 is a wet multi-plate friction clutch formed of an iron-based material. The main clutch 30 is disposed between the inner peripheral surface of the cylindrical portion of the front housing 11 and the outer peripheral surface of the inner shaft 20. The main clutch 30 is disposed between the bottom of the front housing 11 and the vehicle front end surface of the rear housing 12. The main clutch 30 includes an inner main clutch plate 31 and an outer main clutch plate 32, and is alternately arranged in the axial direction. The inner main clutch plate 31 has a female spline 31 a formed on the inner peripheral side, and is fitted to the male spline 20 a of the inner shaft 20. The outer main clutch plate 32 has a male spline 32 a formed on the outer peripheral side, and is fitted to the female spline 11 a of the front housing 11.

  The electromagnetic clutch device 40 engages the pilot clutches 44 by pulling the armature 43 toward the yoke 41 by magnetic force. That is, the electromagnetic clutch device 40 transmits the torque of the outer case 10 to the support cam member 51 that constitutes the cam mechanism 50. The electromagnetic clutch device 40 includes a yoke 41, an electromagnetic coil 42, an armature 43, and a pilot clutch 44.

  The yoke 41 is formed in an annular shape and is accommodated in an annular groove of the rear housing 12 through a gap so as to be rotatable relative to the rear housing 12. The yoke 41 is fixed to the hole cover. Moreover, the inner peripheral side of the yoke 41 is rotatably supported by the rear housing 12 via a bearing. The electromagnetic coil 42 is formed in an annular shape by winding a winding, and is fixed to the yoke 41.

  The armature 43 is made of an iron-based material. It is formed in an annular shape having a male spline on the outer peripheral side. The armature 43 is disposed between the main clutch 30 and the rear housing 12 in the axial direction. The outer peripheral side of the armature 43 is fitted into the female spline 11a of the front housing 11. The armature 43 acts so as to be drawn toward the yoke 41 when a current is supplied to the electromagnetic coil 42.

  The pilot clutch 44 transmits torque between the outer case 10 and the support cam member 51. The pilot clutch 44 is made of an iron-based material. The pilot clutch 44 is disposed between the inner peripheral surface of the cylindrical portion of the front housing 11 and the outer peripheral surface of the support cam member 51. Further, the pilot clutch 44 is disposed between the armature 43 and the vehicle front end surface of the rear housing 12. The pilot clutch 44 includes an inner pilot clutch plate 44a and an outer pilot clutch plate 44b, and is alternately arranged in the axial direction. The inner pilot clutch plate 44 a has a female spline formed on the inner peripheral side, and is fitted to the male spline of the support cam member 51. The outer pilot clutch plate 44 b has a male spline formed on the outer peripheral side, and is fitted to the female spline 11 a of the front housing 11.

  When a current is supplied to the electromagnetic coil 42, the yoke 41, the outer periphery of the rear housing 12, the pilot clutch 44, the armature 43, the pilot clutch 44, and the inner periphery of the rear housing 12 are indicated by arrows in FIG. A magnetic circuit passing through the yoke 41 is formed. As a result, the armature 43 is pulled toward the yoke 41 and the inner pilot clutch plate 44a and the outer pilot clutch plate 44b are frictionally engaged. Then, the torque of the outer case 10 is transmitted to the support cam member 51. On the other hand, when the current supply to the electromagnetic coil 42 is interrupted, the attractive force to the armature 43 is lost, and the frictional engagement force between the inner pilot clutch plate 44a and the outer pilot clutch plate 44b is released.

  The cam mechanism 50 is provided between the main clutch 30 and the pilot clutch 44, and converts torque based on the rotational difference between the outer case 10 and the inner shaft 20 transmitted through the pilot clutch 44 into axial pressing force. Then, the main clutch 30 is pressed. The cam mechanism 50 includes a support cam member 51, a moving cam member 52, and a cam follower 53.

  The support cam member 51 is formed in an annular shape having a male spline on the outer peripheral side. A cam groove is formed in the vehicle front end surface of the support cam member 51. The support cam member 51 is provided via a gap with respect to the outer peripheral surface of the inner shaft 20, and is supported on the vehicle front end surface of the rear housing 12 via a thrust bearing 60. Therefore, the vehicle rear end surface of the support cam member 51 is in contact with the raceway plate of the thrust bearing 60 via the shim 61. That is, the support cam member 51 is rotatable relative to the inner shaft 20 and the rear housing 12 and is provided to be regulated with respect to the axial direction. Further, the male spline of the support cam member 51 is fitted to the female spline of the inner pilot clutch plate 44a.

  The moving cam member 52 is mostly formed of an iron-based material, and is formed in an annular shape having a female spline on the inner peripheral side. The moving cam member 52 is disposed in front of the support cam member 51 in the vehicle. A cam groove is formed on the vehicle rear end surface of the movable cam member 52 so as to face the cam groove of the support cam member 51 in the axial direction. The female spline of the moving cam member 52 is fitted to the male spline 20 a of the inner shaft 20. Accordingly, the movable cam member 52 rotates together with the inner shaft 20. Furthermore, the vehicle front end surface of the movable cam member 52 is in a state where it can abut on the inner main clutch plate 31 disposed at the rearmost of the main clutch 30. When the moving cam member 52 moves forward of the vehicle, the moving cam member 52 presses the inner main clutch plate 31 forward of the vehicle. Here, details of the movable cam member 52 will be described later with reference to FIGS.

  The cam follower 53 has a ball shape and is interposed in the cam grooves of the support cam member 51 and the movable cam member 52 facing each other. That is, when the cam follower 53 and the respective cam grooves act to cause a rotation difference between the support cam member 51 and the moving cam member 52, the moving cam member 52 is separated from the support cam member 51 in the axial direction. Move to (front of vehicle). The axial separation distance of the movable cam member 52 from the support cam member 51 increases as the twist angle between the support cam member 51 and the movable cam member 52 increases.

(Basic operation of the driving force transmission device)
Next, a basic operation of the driving force transmission device 1 having the above-described configuration will be described. A case where the outer case 10 and the inner shaft 20 cause a rotation difference will be described. When a current is supplied to the electromagnetic coil 42 of the electromagnetic clutch device 40, a loop-shaped magnetic circuit that circulates through the yoke 41, the rear housing 12, and the armature 43 with the electromagnetic coil 42 as a base point is formed.

  Thus, by forming a magnetic circuit, the armature 43 is drawn toward the yoke 41 side, that is, toward the rear in the axial direction. As a result, the armature 43 presses the pilot clutch 44, and the inner pilot clutch plate 44a and the outer pilot clutch plate 44b are frictionally engaged. Then, the rotational torque of the outer case 10 is transmitted to the support cam member 51 via the pilot clutch 44, and the support cam member 51 rotates.

  Here, since the movable cam member 52 is spline-fitted with the inner shaft 20, it rotates together with the inner shaft 20. Therefore, a rotation difference is generated between the support cam member 51 and the movable cam member 52. Then, the movable cam member 52 moves in the axial direction (front side of the vehicle) with respect to the support cam member 51 by the action of the cam follower 53 and the respective cam grooves. The moving cam member 52 presses the main clutch 30 toward the vehicle front side.

  As a result, the inner main clutch plate 31 and the outer main clutch plate 32 come into contact with each other to be in a friction engagement state. Then, rotational torque with the outer case 10 is transmitted to the inner shaft 20 via the main clutch 30. Then, the rotation difference between the outer case 10 and the inner shaft 20 can be reduced. Note that the friction engagement force of the main clutch 30 can be controlled by controlling the amount of current supplied to the electromagnetic coil 42. That is, the torque transmitted between the outer case 10 and the inner shaft 20 can be controlled by controlling the amount of current supplied to the electromagnetic coil 42.

(Detailed configuration of moving cam member)
Next, the detailed configuration of the movable cam member 52 will be described with reference to FIGS. The moving cam member 52 is made of a magnetic material containing iron as a main component so that torque transmitted through the support cam member 51 can be converted into an axial pressing force. For example, the moving cam member 52 is made of an alloy containing iron, nickel, copper, molybdenum, carbon, or the like.

  As shown in FIG. 2, the moving cam member 52 is formed in an annular shape and has a stepped inner peripheral surface that expands in diameter toward the front side of the vehicle. A female spline 110 is formed on the large diameter side of the inner circumferential surface of the step. A cam groove 120 is formed on the rear end surface of the movable cam member 52 so as to face the cam groove of the support cam member 51 in the axial direction. Further, an annular protrusion 130 is formed on the outer peripheral edge of the moving cam member 52 on the vehicle rear end surface. That is, the protrusion 130 is formed to project in an annular shape on the armature 43 (shown in FIG. 1) side. The projecting portion 130 abuts the armature 43 to restrict the axial movement of the armature 43 opposite to the yoke 41 side.

  The protrusion 130 is a part for easily forming a desired axial gap between the armature 43 and the pilot clutch 44 between the protrusion 130 and the yoke 41 in the axial direction. That is, the axial gap can be set to a desired value by adjusting the protrusion amount of the protrusion 130. For example, it is possible to cope with fluctuations in the number of pilot clutches 44.

  The projecting portion 130 has an inner peripheral cylindrical surface 131 formed to have the same diameter in the axial direction, an outer peripheral cylindrical surface 132 formed to have the same diameter in the axial direction, and a planar armature 43 formed perpendicular to the axis. An annular end surface 133 that can contact the inner peripheral surface, a tapered inner peripheral chamfer 134 that connects the inner peripheral cylindrical surface 131 and the inner peripheral edge of the end surface 133, and a tapered shape that connects the outer peripheral cylindrical surface 132 and the outer peripheral edge of the end surface 133. The outer peripheral chamfer 135 is provided. That is, when the armature 43 moves to the protruding portion 130 side of the moving cam member 52, the armature 43 contacts the end surface 133 and does not contact other portions. In particular, the inner peripheral chamfer 134 and the outer peripheral chamfer 135 do not contact the armature 43.

  Here, the protrusion 130 is designed as follows. The inner diameter Di of the inner peripheral cylindrical surface 131 is set in the range of 92 mm or more and 112 mm or less. The outer diameter Do of the outer peripheral cylindrical surface 132 is set in the range of 96 mm or more and 116 mm or less. Further, the radial length Wb of the end surface 133 is set in a range of 1.3 mm or more and 2.0 mm or less. By designing in this way, the electromagnetic clutch device 40 can function reliably, and as a result, the driving force transmission device 1 can also function reliably.

  Preferably, the inner diameter Di of the inner peripheral cylindrical surface 131 is set in the range of 97 mm to 107 mm, and the outer diameter Do of the outer peripheral cylindrical surface 132 is set in the range of 101 mm to 111 mm. By designing in this way, the electromagnetic clutch device 40 can be made to function more preferably. More preferably, the inner diameter Di of the inner peripheral cylindrical surface 131 is set to 101.9 mm, and the outer diameter Do of the outer peripheral cylindrical surface 132 is set to a range of 105.8 mm to 106.2 mm. The radial length Wa is set in a range of 1.95 mm or more and 2.15 mm or less. By designing in this way, the electromagnetic clutch device 40 can be made to function more preferably.

(Reason to function as an electromagnetic clutch device)
Next, the reason why the electromagnetic clutch device 40 can be surely functioned by designing the protrusion 130 within the above-described range will be described. First, the effect | action by making radial direction length Wb of the end surface 133 of the projection part 130 2.0 mm or less is demonstrated with reference to FIGS.

  Here, when a current is supplied to the electromagnetic coil 42, as shown by arrows in FIG. 1, the yoke 41, the outer peripheral side of the rear housing 12, the outer peripheral side of the pilot clutch 44, the armature 43, the inner peripheral side of the pilot clutch 44, A magnetic circuit passing through the yoke 41 on the inner peripheral side of the rear housing 12 is formed. In addition, the leakage flux from the armature 43 to the moving cam member 52 causes the yoke 41, the outer periphery of the rear housing 12, the outer periphery of the pilot clutch 44, the armature 43, the moving cam member 52, the inner shaft 20, and the rear housing 12 to A residual magnetic circuit that passes through the yoke 41 on the inner peripheral side is formed.

  When the armature 43 is in contact with the end face 133 of the protrusion 130 of the moving cam member 52, when the current is supplied to the electromagnetic coil 42, the attractive force F of the armature 43 by the moving cam member 52 generated by the residual magnetic circuit. Is expressed as in equation (1). In Equation (1), B is the residual magnetic flux density in the residual magnetic circuit, S is the contact area between the protrusion 130 and the armature 43, and μ is the magnetic permeability.

  Here, when the radial length Wb of the end surface 133 of the protrusion 130 is shortened, the contact area S is decreased, and as a result, the residual magnetic flux density B is increased. From equation (1), the attractive force F due to the leakage magnetic flux is proportional to the square of the residual magnetic flux density B and proportional to the contact area S between the protrusion 130 and the armature 43. The influence of B becomes large. Therefore, as the radial length Wb of the end surface 133 of the protrusion 130 is shortened, the attracting force F increases.

  An experiment was conducted on this relationship. The analysis conditions are as follows. The moving cam member 52 is an alloy of 93.5Fe-4Ni-1.5Cu-0.5Mo-0.5C, the yoke 41 is S10, the rear housing 12 is S10C, the armature 43 is SPH270C, and the pilot clutch 44 is SPS85 (SK5M). The inner diameter Di of the inner peripheral cylindrical surface 131 of the protrusion 130 is 101.9 mm, and the outer diameter Do of the outer peripheral cylindrical surface 132 is 106.1 mm.

  Further, in the experimental procedure, after the armature 43 is brought into contact with the end surface 133 of the protrusion 130, the initial current 4A is supplied to the electromagnetic coil 42, the moving cam member 52 is magnetized, and the current is supplied to the electromagnetic coil 42. Shut off. Thereafter, the supply current to the electromagnetic coil 42 was gradually increased, and the supply current (hereinafter referred to as “attracting current”) when the armature 43 moved to the yoke 41 side was measured. However, the maximum value of the supply current is 4A. Here, the experimental procedure is that the armature 43 moves to the movable cam member 52 side after the unit of the driving force transmission device 1 is manufactured and then assembled to the vehicle, and then the 4A It is assumed that control is performed by supplying current to the electromagnetic coil 42.

  And in said experiment, the attraction current at the time of changing radial direction length Wb of the end surface 133 of the projection part 130 was measured. Specifically, an experiment was conducted with respect to 1.04 mm, 1.05 mm, 1.42 mm, and 1.53 mm in the radial length Wb of the end surface 133 of the protrusion 130. Here, the axial clearance between the armature 43 and the pilot clutch 44 between the protrusion 130 of the movable cam member 52 and the yoke 41 is 1.0 mm.

  The result is shown in FIG. As shown in FIG. 4, when the radial length Wb of the end face 133 of the protrusion 130 is 1.05 mm, the attracting current is 4 A, and when it is less than 1.05 mm, the supply current is 4 A. Could not attract. Further, when the radial length Wb is 1.05 mm or more, the attracting current is linearly decreased as the radial length Wb is increased.

  In the next experiment, the attraction current was measured when the axial gap between the armature 43 and the pilot clutch 44 was changed between the projection 130 of the movable cam member 52 and the yoke 41 in the axial direction.

  The result is shown in FIG. As shown in FIG. 5, the attracting current increases as the axial gap increases. As shown in FIG. 4, the attracting current increases as the radial length Wb of the end surface 133 increases. When the attracting current is set to 1.3 A or less, when the radial length Wb of the end face 133 is 1.3 mm or more, the armature can be surely provided with an axial clearance of 0.01 mm to 0.8 mm. It can be seen that 43 can be pulled toward the yoke 41 side.

  Here, the reason why the attracting current is set to 1.3 A or less is that the current applied as the reserve current before applying the control current is 1.3 A. The reason why the maximum value of the axial clearance is set to 0.8 mm is that the value is the maximum clearance when the minimum value of the variation in the axial dimension of the component is accumulated.

  That is, when the control current of the electromagnetic coil 42 is set to 1.3 A or less and the axial gap is set to 0.8 mm or less, the radial length Wb of the end face 133 is reliably set to 1.3 mm or more. The armature 43 can be pulled toward the yoke 41 side.

  Further, as the length in the radial direction of the end surface 133 of the protrusion 130 is increased, a larger force is required to move the armature 43 away from the protrusion 130 due to the squeeze effect of the lubricating oil. Therefore, within the range of the inner diameter Di of the inner cylindrical surface 131 and the outer diameter Do of the outer cylindrical surface 132 described above, the length in the radial direction of the end surface 133 of the protruding portion 130 is set to 2.0 mm or less, so that the lubricating oil The adsorption force due to the squeeze effect can be made sufficiently small.

  As described above, by setting the radial length of the end surface 133 of the protrusion 130 in the range of 1.3 mm or more and 2.0 mm or less, the electromagnetic clutch device 40 can be reliably functioned, and as a result, the driving force is transmitted. The device 1 can also function reliably.

1: driving force transmission device, 10: outer case (outer rotating member), 20: inner shaft (inner rotating member), 30: main clutch, 40: electromagnetic clutch device, 41: yoke, 42: electromagnetic coil, 43: armature 44: pilot clutch, 50: cam mechanism, 51: support cam member, 52: moving cam member, 53: cam follower, 130: projection, 131: inner cylindrical surface, 132: outer cylindrical surface, 133: end surface, 134 : Inner peripheral chamfer 135: Outer peripheral chamfer

Claims (3)

A cylindrical outer rotating member;
A shaft-like inner rotating member disposed coaxially in the outer rotating member so as to be relatively rotatable;
A main clutch that transmits torque between the outer rotating member and the inner rotating member;
An electromagnetic clutch device comprising a pilot clutch capable of transmitting the torque of the outer rotating member by attracting the armature to the yoke side by magnetic force;
A phase difference between the rotation of the outer rotating member and the rotation of the inner rotating member, which is provided between the main clutch and the pilot clutch and transmitted via the pilot clutch, is converted into an axial pressing force. A cam mechanism for pressing the main clutch by moving the moving cam member in the axial direction;
Lubricating oil filled between the outer rotating member and the inner rotating member;
In the driving force transmission device comprising:
The movable cam member is formed to project annularly on the armature side, and includes a protrusion that regulates movement of the armature in a direction opposite to the yoke side by contacting the armature,
The protrusion includes an inner peripheral cylindrical surface, an outer peripheral cylindrical surface, an annular end surface that can contact the armature, and a tapered inner peripheral chamfer that connects the inner peripheral cylindrical surface and the inner peripheral edge of the end surface. A tapered outer peripheral chamfer connecting the outer peripheral cylindrical surface and the outer peripheral edge of the end surface;
A driving force transmission device in which a radial length of the end face is set in a range of 1.3 mm or more and 2.0 mm or less. In claim 1,
An inner diameter of the inner cylindrical surface of the protrusion is set in a range of 92 mm to 112 mm,
The driving force transmission device, wherein an outer diameter of the outer peripheral cylindrical surface of the protrusion is set in a range of 96 mm to 116 mm. A cylindrical outer rotating member;
A shaft-like inner rotating member disposed coaxially in the outer rotating member so as to be relatively rotatable;
A main clutch that transmits torque between the outer rotating member and the inner rotating member;
An electromagnetic clutch device comprising a pilot clutch capable of transmitting the torque of the outer rotating member by attracting the armature to the yoke side by magnetic force;
A phase difference between the rotation of the outer rotating member and the rotation of the inner rotating member, which is provided between the main clutch and the pilot clutch and transmitted via the pilot clutch, is converted into an axial pressing force. A cam mechanism for pressing the main clutch by moving the moving cam member in the axial direction;
Lubricating oil filled between the outer rotating member and the inner rotating member;
In the design method of the driving force transmission device comprising:
The movable cam member is formed to project annularly on the armature side, and includes a protrusion that regulates movement of the armature in a direction opposite to the yoke side by contacting the armature,
The protrusion includes an inner peripheral cylindrical surface, an outer peripheral cylindrical surface, an annular end surface that can contact the armature, and a tapered inner peripheral chamfer that connects the inner peripheral cylindrical surface and the inner peripheral edge of the end surface. A tapered outer peripheral chamfer connecting the outer peripheral cylindrical surface and the outer peripheral edge of the end surface;
A method for designing a driving force transmission device, wherein the radial length of the end face is designed in a range of 1.3 mm to 2.0 mm.

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