JP2004187476A - Electromagnetic actuator and differential gear employing it - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To obtain an electromagnetic actuator in which a plunger can be moved with small thrust force, an electromagnetic coil can be reduced in size, current consumption can be reduced, and response can be enhanced. <P>SOLUTION: The electromagnetic actuator 1 comprises a clutch ring 59 rotating together with a differential case 5 and moving freely in the axial direction between a position allowing differential rotation and a position for locking differential rotation, a cylindrical guide member 75 disposed on the outside of the differential case 5, a cylindrical plunger 73 disposed movably in the axial direction using the guide member 75 as a guiding surface, and an electromagnetic coil 67 wherein the clutch ring 59 rotating together with the differential case 5 is pressed by axial shift of the plunger 73 caused through excitation of the electromagnetic coil 67. The plunger 73 is coupled with the clutch ring 59 through a means 77 rotating together. <P>COPYRIGHT: (C)2004,JPO&NCIPI

Description

[0001]
TECHNICAL FIELD OF THE INVENTION
The present invention relates to an electromagnetic actuator for operating an operated member such as a clutch member, and a differential device for changing an operation mode (differential rotation and lock thereof) using such an electromagnetic actuator.
[0002]
[Prior art]
FIG. 4 shows a differential device described in Japanese Patent Publication No. 5-54574 (Patent Document 1). This differential device 100 is one in which driving is interrupted when two-wheel switching of a part-time four-wheel drive vehicle is performed, and is applied to a front differential of the vehicle.
[0003]
The differential device 100 includes an inner differential case 103 and an outer differential case 105. A pinion shaft 107 is fixed inside the inner differential case 103, and a pinion gear 109 is rotatably attached to the pinion shaft 107. Left and right side gears 113, 113 to which drive shafts 111, 111 are splined are meshed with the pinion gear 109. The drive shafts 111, 111 protrude outward from the left and right bosses 115, 117 of the inner differential case 103, and the left and right wheels are mounted on the protruding portions. The outer differential case 105 is disposed on the bosses 115 and 117 of the inner differential case 103 and is relatively rotatable via a ball bearing 119. The left and right boss portions 121 and 123 of the outer differential case 105 are rotatably supported by a differential carrier 127 via a tapered roller bearing 125.
[0004]
A ring gear 129 is fixed to the outer differential case 105, and the ring gear 129 meshes with the propeller shaft 131, so that a rotational force from the engine is input to rotate the outer differential case 105. A spline-connected sleeve 133 is disposed on the boss 115 of the inner differential case 103 so as to be movable in the axial direction. An annular recess 135 is formed on the outer periphery of the sleeve 133, and a shift fork 137 is engaged with the recess 135 so as to be relatively rotatable. The shift fork 137 is connected to a pneumatic or hydraulic cylinder 139 provided on a differential carrier 127, and the sleeve 133 moves in a reciprocating direction by driving the cylinder 139. The cylinder 139 is driven to expand and contract by a remote operation from the driver's seat side.
[0005]
A clutch unit 141 is provided at a portion where the sleeve 133 and the outer differential case 105 face each other. The clutch means 141 includes a dog clutch 143 formed in an annular shape on the end face of the sleeve 133, and a dog clutch 145 formed on the end face of the boss 121 of the outer differential case 105 and meshing with the dog clutch 143.
[0006]
In this differential device 100, the outer differential case 105 and the inner differential case 103 are connected by extending the cylinder 139 to move the sleeve 133 to the right, and engaging the dog clutch 143 with the dog clutch 145 of the outer differential case 105. . Thus, four-wheel drive traveling is performed. On the other hand, the cylinder 139 is shortened and the sleeve 133 is driven leftward to release the dog clutches 143 and 145 from each other, thereby enabling two-wheel drive traveling.
[0007]
In such a differential device 100, the cylinder 139 is used as an actuator for engaging and disengaging the dog clutches 143 and 145. However, the actuator is driven by fluid pressure such as pneumatic pressure and hydraulic pressure, so that the size is increased. . In particular, when traveling at high altitudes and the like, the fluid pressure is easily affected by the atmospheric pressure, and therefore, it is necessary to increase the size of the actuator.
[0008]
To solve such a problem, a vehicle differential lock device 501 using an electromagnetic actuator is described in Japanese Patent Application Laid-Open No. 64-22633 (Patent Document 2). As shown in FIG. 5, the vehicle differential lock device 501 includes a bevel gear type differential mechanism 503, a dog clutch 505 for locking the differential rotation thereof, an electromagnetic actuator 507 for engaging the dog clutch 505, and a dog clutch. A return spring 509 for releasing the meshing of 505 and the like are provided. The driving force of the engine for rotating the differential case 511 is distributed from the side gears 513 and 515 of the differential mechanism 503 to the left and right wheels via respective axles 517 and 519.
[0009]
The dog clutch 505 is provided between the differential case 511 and a plunger 521 made of a magnetic material, and the plunger 521 is spline-connected to an axle 517 on the left side gear 513 side so as to be movable in the axial direction. Also, the plunger 521 is urged by the return spring 509 in the direction of releasing the dog clutch 505 from meshing (to the left in FIG. 6).
[0010]
The electromagnetic actuator 507 includes an electromagnetic coil 525 wound on a bearing housing 523 made of a magnetic material and disposed on the outer periphery of the plunger 521, the above-described plunger 521, and the like. A magnetic path of the electromagnetic coil 525 is configured by the above. While the electromagnetic coil 525 is not excited, the plunger 521 is moved to the position shown in FIG. 6 by the urging force of the return spring 509. In this state, the engagement of the dog clutch 505 and the differential lock of the differential mechanism 503 are not performed. It has been released. Further, when the electromagnetic coil 525 is excited, a magnetic flux loop is formed in the magnetic path, and the plunger 521 moves rightward by the moving operation force generated by the magnetic force, and engages the dog clutch 505 to drive the differential mechanism. The differential of 503 is locked.
[0011]
Locking the differential in a situation where the driving wheels are likely to idle, such as when driving on a rough road, prevents the driving force from escaping from the idle wheels, improving escape and running ability on rough roads, etc. Stacking is prevented. As described above, the electromagnetic actuator 507 is configured compactly by arranging the electromagnetic coil 525 and the plunger 521 coaxially, has a high unity, and is superior in vehicle mountability.
[0012]
[Patent Document 1]
Japanese Patent Publication No. 5-54574
[Patent Document 2]
JP-A-64-22633
[Problems to be solved by the invention]
However, in the conventional electromagnetic actuator 507, although the plunger 521 moves in the axial direction while being guided by the bearing housing 523, static friction resistance acts between the plunger 521 and the bearing housing 523 when the plunger 521 moves. However, a large thrust is required because the robot must move against the static frictional resistance.
[0015]
In addition, if the magnetic force generated by the electromagnetic coil 525 varies, or if the formed magnetic flux loop is deviated, the plunger 521 makes one contact with the inner wall of the bearing housing 523 or the axle 517 (biased sliding). Move), and the frictional resistance increases.
[0016]
In addition, when the length of the plunger 521 is set to be short in the radial direction for reasons such as downsizing of the device, twisting (axial inclination) is likely to occur, and when twisting occurs, a contact is caused due to hitting. The frictional resistance further increases.
[0017]
In addition, it is desirable that the gap between the plunger 521 and the bearing housing 523 is machined so as to be constant in the circumferential direction. However, in actuality, such machining is impossible, and the static friction resistance is reduced. Brings increase. The increase in the movement resistance of the plunger 521 causes the operation of the electromagnetic actuator 507 to be less smooth, resulting in a poor response.
[0018]
In preparation for such an increase in the movement resistance of the plunger 521, it is necessary to increase the size of the electromagnetic coil 525 of the electromagnetic actuator 507 or increase the exciting current to the electromagnetic coil 525 to increase the thrust to the plunger 521. there were.
[0019]
Therefore, the present invention has been made to solve the above-mentioned problem, and an electromagnetic type in which a plunger can be smoothly moved with a small thrust, miniaturization of an electromagnetic coil, reduction in current consumption, and improvement in response. An object of the present invention is to provide an actuator and a differential device using the same.
[0020]
[Means for Solving the Problems]
The invention according to claim 1 is a cylindrical guide member arranged on the outer peripheral side of the rotating body about the rotational axis center of the rotating body, and on the outer peripheral side of the rotating body about the rotating axis center of the rotating body. A cylindrical plunger disposed so as to be movable in the axial direction with a circumferential surface of the guide member as a guide surface; and an electromagnetic coil for applying an axial thrust to the plunger by excitation, the electromagnetic coil comprising: An electromagnetic actuator that displaces the plunger in the axial direction by exciting the coil and moves the plunger in the axial direction by pressing a member to be rotated that rotates together with the rotating body, through co-rotating means that rotates the plunger together. And is connected to the operated member.
[0021]
In this electromagnetic actuator, when the plunger moves by excitation of the electromagnetic coil, the plunger and the guide member slide relative to each other in the rotational direction because the plunger is rotating together with the rotating body, so that the axial direction is improved. Therefore, the movement in the axial direction of the plunger (even in the case of sliding) moves with substantially no resistance.
[0022]
The invention according to claim 2 is a differential case that rotates by receiving a driving force of an engine, a differential mechanism that distributes the rotation of the differential case from a pair of side gears to the wheel side, and rotates together with the differential case, and the differential case and the pair of the A differential position that allows relative rotation with a side gear, and a clutch member that is axially movable between a differential lock position that integrally rotates the differential case and the pair of side gears, and A cylindrical guide member arranged on the outer peripheral side of the differential case around the rotational axis center of the differential case; and a circumferential surface of the guide member arranged on the outer peripheral side of the differential case around the rotational axis center of the differential case. A cylindrical plunger arranged movably in the axial direction with the plunger as a guide surface, and an axial thrust applied to the plunger by excitation. And an electromagnetic actuator that presses the clutch member that rotates together with the differential case by axial displacement of the plunger due to excitation of the electromagnetic coil to move the clutch member in the axial direction. The clutch member is connected to the clutch member via co-rotating means for rotating.
[0023]
In this differential device, when the plunger moves by excitation of the electromagnetic coil, the plunger rotates together with the differential case, so that a dynamic frictional resistance much smaller than the static frictional resistance acts between the plunger and the guide member. The plunger moves with substantially no resistance.
[0024]
BEST MODE FOR CARRYING OUT THE INVENTION
Hereinafter, embodiments of the present invention will be described with reference to the drawings.
[0025]
1 and 2 show an embodiment of the present invention. FIG. 1 is a sectional view of a differential device, FIG. 2A is a configuration diagram of an electromagnetic actuator, and FIG. is there. In the following description, the left and right directions are the left and right directions of the vehicle in which the differential device 3 was used.
[0026]
As shown in FIG. 1, the differential device 3 includes an electromagnetic actuator 1, a differential case 5 which is a rotating body, a berl gear type differential mechanism 7, a dog clutch 9, a return spring 11, a position switch 13, a controller, and the like. I have.
[0027]
The differential case 5, which is a rotating body, includes a casing body 15 and left and right covers 17, 19, and the casing body 15 and the left cover 17 are fixed with bolts 21, and the casing body 15 and the right cover 19 are welded. ing.
[0028]
The differential case 5 is disposed inside the differential carrier 23, and the boss portions 25, 27 formed on the covers 17, 19 are supported by the differential carrier 23 via tapered roller bearings 29, respectively. An oil reservoir is formed inside the differential carrier 23.
[0029]
A ring gear is fixed to the differential case 5 with bolts, and the ring gear meshes with a gear of a power transmission system. The power transmission system is connected to the transmission side, and the differential case 5 is rotationally driven by the driving force of the engine transmitted through the transmission and the power transmission system.
[0030]
The differential mechanism 7 includes a plurality of pinion shafts 31, a pinion gear 33 rotatably supported by each of the pinion shafts 31, and output side gears 35 and 37.
[0031]
Each pinion shaft 31 has an end engaged with a through hole 39 provided in the casing main body 15 of the differential case 5 and is prevented from coming off by a spring pin 41. The side gears 35 and 37 are in mesh with the respective pinion gears 33 from left and right.
[0032]
A spherical washer 43 is arranged between the differential case 5 and the pinion gear 33, and receives a centrifugal force of the pinion gear 33 and a meshing reaction force generated in the pinion gear 33 by meshing with the side gears 35 and 37.
[0033]
The boss portions 45, 47 of the side gears 35, 37 are supported by support portions 49, 51 formed on the covers 17, 19, and the boss portions 45, 47 are connected to the left and right wheels via spline-connected axles. It is connected to.
[0034]
A thrust washer 53 is disposed between the left side gear 35 and the differential case 5, receiving a meshing reaction force of the side gear 35, and thrust washers 55 and 56 are disposed between the right side gear 37 and the differential case 5. 37 engagement reaction force.
[0035]
The dog clutch 9 includes a meshing tooth 57 formed on the right side gear 37 and a meshing tooth 61 formed on a clutch ring (clutch member) 59 which is a member to be operated.
[0036]
The clutch ring 59 has legs 63 formed at equal intervals in the circumferential direction. The clutch ring 59 is arranged so as to be prevented from rotating by the differential case 5 by penetrating the legs 63 through openings 65 formed at regular intervals in the circumferential direction formed in the cover 19 and to be movable in the axial direction. The ring 59 is rotated together with the differential case 5. A ring-shaped pressure plate 89 is fixed to the right end of the clutch ring 59.
[0037]
When the clutch ring 59 moves to the left, the dog clutch 9 meshes and the differential of the differential mechanism 7 is locked. As shown in FIG. 1, when it moves to the right, the meshing of the dog clutch 9 is released and the differential lock is released. It is released.
[0038]
The return spring 11 is disposed between the right side gear 37 and the clutch ring 59, and urges the clutch ring 59 to the side where the dog clutch 9 is disengaged (to the right).
[0039]
As shown in detail in FIG. 2A, the electromagnetic actuator 1 includes an electromagnetic coil 67, a pair of coil housings 69 and 71 integrally formed by sandwiching the electromagnetic coil 67 from left and right, a guide member 75, a plunger 73, and the like. ing.
[0040]
The coil housing 71 is fixed to the differential carrier 23 via a connecting member, and the lead wire of the electromagnetic coil 67 is drawn out of the differential carrier 23 and connected to a vehicle-mounted battery via a controller.
[0041]
The coil housings 69 and 71 are formed of a ferromagnetic material, and are axially arranged between the right boss 27 of the differential case 5 and the inner race 83 of the taper roller bearing 29 by left and right thrust washers 79 and 81. Positioned.
[0042]
The guide member 75 is formed in a substantially cylindrical shape from a non-magnetic material, and is arranged on the outer peripheral side of the boss portion 27 of the cover 19 about the center of the rotation axis of the differential case 5. The guide member 75 is fixed to the coil housing 71 by welding or the like, and does not rotate even when the differential case 5 rotates.
[0043]
The plunger 73 has a cylindrical shape, is arranged on the outer peripheral side of the boss 27 of the cover 19 about the center of the rotation axis of the differential case 5, and is freely movable in the axial direction using the outer circumferential surface of the guide member 75 as a guide surface. Are located in The plunger 73 is formed of a ferromagnetic material, and forms a magnetic path of the electromagnetic coil 67 together with the coil housings 69 and 71. The plunger 73 is an armature, and a leftward thrust acts upon excitation of the electromagnetic coil 67.
[0044]
As shown in detail in FIGS. 2A and 2B, the left end of the plunger 73 allows movement in the axial direction and rotates the pressure plate 89 of the clutch ring 59 through co-rotating means 77 that rotates together. It is connected to. The co-rotating means 77 includes a locking groove 77a formed on the end face of the plunger 73 and a locking projection 77b formed on the pressure plate 89 and inserted into the locking groove 77a. The locking state between the locking groove 77a and the locking projection 77b is set so that the plunger 73 is held even at the position where the plunger 73 is shifted to the right to the maximum.
[0045]
The position switch 13 is mounted on the differential carrier 23 and is turned on / off according to the position of the pressure plate 89. The on / off signal is sent to the controller, and the controller detects the operation state of the electromagnetic actuator 1.
[0046]
The controller controls the operation of the electromagnetic actuator 1.
[0047]
Next, the operation of the differential device 3 will be described. When the driving force from the engine is transmitted to the ring gear, the differential case 5 rotates around the center of the rotating shaft, and the rotation of the differential case 5 is transmitted in the order of the pinion shaft 31, the pinion gear 33, the side gears 35 and 37, and Wheels are rotated. Then, when a difference occurs in the reaction force from the left and right wheels due to turning of the vehicle or the like, the pinion gear 33 rotates while rotating and performs differential rotation.
[0048]
In such a state, when a differential lock command is output to the controller, the controller energizes the electromagnetic coil 67. Then, a loop magnetic field having the coil housings 69 and 71 and the plunger 73 as a magnetic path is formed, and a leftward thrust is generated in the plunger 73. Here, since the plunger 73 is connected to the clutch ring 59 via the co-rotating means 77, the plunger 73 rotates together with the differential case 5.
[0049]
Therefore, when the plunger 73 is moved, the plunger 73 and the guide member 75 are relatively slid in the rotational direction, so that the axial gaze is suppressed. Therefore, the plunger 73 is moved in the axial direction (even in the case of sliding). Can move with substantially no resistance. As described above, the plunger 73 is smoothly moved with a small thrust, and the size of the electromagnetic coil 67 can be reduced, the current consumption can be reduced, and the response can be improved.
[0050]
Further, in the present embodiment, the frictional resistance generated when the plunger 73 hits the guide member 75 due to the movement in the radial direction is obtained by rotating the plunger 73 together with the differential case 5 via the co-rotating means 77 in advance. It can be substantially eliminated. As a result, since the operation of the plunger 73 is not hindered, the response is improved, and the magnetic force for operating the plunger 73 can be reduced, so that the current consumption of the electromagnetic coil 67 can be reduced.
[0051]
3A and 3B show a modification of the electromagnetic actuator 1. FIG. 3A is a configuration diagram of the electric actuator, and FIG. 3B is a plan view of the co-rotating means.
[0052]
The electromagnetic actuator 1 of this modification is different from that of the above embodiment only in the configuration of the co-rotating means 77. As shown in FIGS. 3A and 3B, the co-rotating means 77 includes a meshing tooth 77c formed on the end face of the plunger 73 and a meshing tooth 77d formed on the pressure plate 89 and meshing with the meshing tooth 77c. It is configured. The meshing state of the two meshing teeth 77c and 77d is set so that the plunger 73 is held even at the position where the plunger 73 is shifted to the right to the maximum.
[0053]
Since other configurations are the same as those of the above-described embodiment, the same portions are denoted by the same reference numerals, and redundant description will be omitted.
[0054]
According to the electromagnetic actuator 1 of this modified example, the same operation and effect as the above embodiment can be obtained.
[0055]
The electromagnetic actuator 1 of the embodiment is used to lock the differential rotation by fixing the differential case 5 and the side gear 37 with the clutch ring 59 and rotating the differential case 5 and the side gear 37 integrally. The electromagnetic actuator of the present invention is not limited to this, and is applicable when the operated member operated by the electromagnetic actuator rotates together with the rotating body. For example, as in the conventional example shown in FIG. 4, a differential case is divided into an outer differential case and an inner differential case, and the divided outer differential case and the inner differential case are rotated integrally or separately and independently. It may be used to switch between drive and two-wheel drive.
[0056]
【The invention's effect】
As described above, according to the first aspect of the present invention, since the plunger is connected to the operated member via the co-rotating means for rotating together, the plunger rotates together with the rotating body, so that the plunger and the guide member are separated. Since the slide is relatively slipped in the rotational direction, the axial glare is suppressed, and therefore, the plunger moves in the axial direction (even in the case of sliding) with almost no resistance. Therefore, the plunger can be moved smoothly with a small thrust, and the size of the electromagnetic coil can be reduced, the current consumption can be reduced, and the response can be improved.
[0057]
According to the second aspect of the present invention, the plunger is connected to the clutch member via the co-rotating means for rotating the plunger together, so that the plunger rotates together with the differential case, so that the friction between the plunger and the guide member is far more than the static friction resistance. A very small kinetic frictional resistance acts, and the excitation of the electromagnetic coil causes the plunger to move with substantially no resistance. Therefore, the plunger can be moved smoothly with a small thrust, and the size of the electromagnetic coil can be reduced, the current consumption can be reduced, and the response can be improved.
[Brief description of the drawings]
FIG. 1 is a cross-sectional view of a differential device according to an embodiment of the present invention.
2A and 2B show an embodiment of the present invention, wherein FIG. 2A is a configuration diagram of an electromagnetic actuator, and FIG. 2B is a plan view of a co-rotating means.
3A and 3B show a modified example of the electromagnetic actuator of the above embodiment, FIG. 3A is a configuration diagram of the electromagnetic actuator, and FIG. 2B is a plan view of a co-rotating means.
FIG. 4 shows a conventional example and is a cross-sectional view of a differential device.
FIG. 5 is a cross-sectional view of a differential device, showing a multifunctional conventional example.
[Explanation of symbols]
1 electromagnetic actuator 3 differential device 5 differential case (rotating body)
7 Differential mechanism 35, 37 Side gear 59 Clutch ring (operated member, clutch member)
67 electromagnetic coil 73 plunger 75 guide member 77 co-rotating means

Claims (2)

A cylindrical guide member arranged on the outer peripheral side of the rotator about the center of the rotation axis of the rotator,
A cylindrical plunger that is arranged on the outer peripheral side of the rotating body around the center of the rotation axis of the rotating body and that is arranged so as to be axially movable with the circumferential surface of the guide member as a guide surface;
An electromagnetic coil that applies an axial thrust to the plunger by excitation,
An electromagnetic actuator that displaces the plunger in the axial direction by exciting the electromagnetic coil, and moves the plunger in the axial direction by pressing an operated member that rotates together with the rotating body,
An electromagnetic actuator, wherein the plunger is connected to the operated member via co-rotating means for rotating the plunger together. A differential case that rotates under the driving force of the engine,
A differential mechanism for distributing the rotation of the differential case from the pair of side gears to the wheel side,
An axial direction between a differential position that rotates with the differential case and allows relative rotation between the differential case and the pair of side gears, and a differential lock position that rotates the differential case and the pair of side gears integrally. And a movable clutch member.
A cylindrical guide member arranged on the outer peripheral side of the differential case around the rotation axis center of the differential case,
A cylindrical plunger that is arranged on the outer peripheral side of the differential case with the rotation axis center of the differential case as a center, and that is arranged to be axially movable with the circumferential surface of the guide member as a guide surface;
An electromagnetic coil that applies an axial thrust to the plunger by excitation,
An electromagnetic actuator that presses the clutch member that rotates together with the differential case by axial displacement of the plunger due to excitation of the electromagnetic coil and moves the clutch member in the axial direction,
A differential device wherein the plunger is connected to the clutch member via co-rotating means for rotating the plunger together.

Images