JP2002005196A - Electromagnetic clutch - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide an electromagnetic clutch which can be miniaturized and rapidly operated. SOLUTION: This electromagnetic clutch 1 comprises a movable core 3 which is provided with an engagement part engaged with a shaft disk 2 fixed to a rotor and a counter-engagement part 34 provided on an end on the opposite side to the engagement part and turnably supported at the engagement position or the disengagement position with respect to the rotor, a fixed core 4 which comprises a projecting piece 41a which is supported by the stator 72 and provided facing one side in the axial direction of the counter-engagement part 34 at the disengagement position, a coil supporting part 42 extended in the axial direction from the projecting piece 41a, and a projecting piece 43a provided on the opposite side to the projecting piece 41a of the supporting part 42 facing the other side in the axial direction of the counter-engagement part 34, and forms a magnetic circuit together with the movable core 3, a coil spring 5 for engaging the movable core 3 at the engagement position, and a coil 6 which is fitted to the coil supporting part 42 of the fixed core 4 and disposed on the disengagement position to attract the movable core 3 against the spring 5 when the coil is excited.

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to an electromagnetic clutch for engaging or disengaging a rotor of a motor by an electromagnet function of a coil and an iron core.

[0002]

2. Description of the Related Art Hitherto, Japanese Patent Laid-Open Publication No. Hei 10-331872 discloses a structure in which an electromagnetic clutch having an engaging portion which moves in a radial direction of a motor rotor, uses a pivot type solenoid.

[0003]

However, the electromagnetic clutch disclosed in the above publication is provided so that the solenoid (iron core / coil) protrudes largely in the radial direction of the rotor.
A device equipped with the clutch is increased in size.

Further, such an electromagnetic clutch is required to operate quickly with a small coil. SUMMARY OF THE INVENTION The present invention has been made to solve the above problems, and an object of the present invention is to provide an electromagnetic clutch which can be reduced in size and can be operated quickly.

[0005]

SUMMARY OF THE INVENTION In order to solve the above problems, an invention according to claim 1 is an electromagnetic clutch which engages with and disengages a rotor of a motor including a stator and a rotor. An engaged portion fixed to the rotor, an engaging portion engaged with the engaged portion, and a magnetic path portion provided at a predetermined position. A movable iron core supported by the stator so as to be rotatable to a non-engagement position; and a movable core supported by the stator and opposed to one axial side of the magnetic passage portion at the non-engagement position. A first protruding piece, a coil supporting portion extending in the axial direction from the first protruding piece, and an opposite side of the magnetic path portion in the axial direction opposite to the first protruding piece of the coil supporting portion. And a second protruding piece provided to form a magnetic circuit with the movable iron core. A biasing member for biasing the movable core to the engagement position, and a biasing member mounted on a coil support portion of the fixed core, and attracting the movable core against the biasing member during excitation to disengage the movable core. The gist of the present invention is to provide a coil disposed at a position.

According to a second aspect of the present invention, there is provided the electromagnetic clutch according to the first aspect, wherein the first and second fixed iron cores are provided.
The gist is that the projecting pieces are extended in the axial direction so as to face each other.

According to a third aspect of the present invention, there is provided the electromagnetic clutch according to the second aspect, wherein the first and second fixed iron cores are provided.
The gist is that a space is provided between the projecting piece and the coil, and the magnetic path portion of the movable iron core is disposed in the space at the non-engagement position.

[0008] The invention according to claim 4 is the invention according to claims 1 to 3.
In the electromagnetic clutch according to any one of the first to third aspects, the opposing surfaces of the first and second projecting pieces of the fixed iron core and the magnetic passage portion of the movable iron core are formed in an arc shape with the rotation center of the movable iron core as its center. The main point is that the curved surface is used.

[0009] The invention according to claim 5 is the invention according to claims 1 to 4.
In the electromagnetic clutch according to any one of the first to third aspects, opposing surfaces of the first and second projecting pieces of the fixed iron core and the magnetic passage portion of the movable iron core are parallel to each other and with respect to a rotation axis of the movable iron core. The gist is that it is inclined.

[0010] The invention according to claim 6 is the invention according to claims 1 to 5.
In the electromagnetic clutch according to any one of the above, the area of the mutually opposing surfaces of the first projecting piece of the fixed core and the magnetic passage portion of the movable core, and the magnetism of the second projecting piece of the fixed core and the movable iron core. The gist is that the areas of the opposing surfaces of the passages are made equal.

(Operation) According to the electromagnetic clutch of the first aspect of the present invention, when the coil is not excited, the movable iron core is disposed at the engagement position by the urging force of the urging member, and the engaging portion is Engage with the engaged portion fixed to the rotor. As a result, the rotation of the rotor is regulated. On the other hand, when the coil is excited, the movable core is attracted by the coil and the fixed core against the biasing force of the biasing member, and the engaging portion of the movable core is separated from the engaged portion in the non-engagement position. Placed in As a result, the rotor becomes rotatable. In this way, the fixed core and the coil for operating the movable core are configured to extend along the axial direction. Therefore, the fixed iron core does not protrude in the radial direction of the rotor, so that downsizing can be achieved. Further, the magnetic circuit formed by the movable core and the fixed iron core can be shortened by the first and second projecting pieces provided at both ends of the coil and the magnetic path of the movable core, so that the magnetic resistance can be reduced. Therefore, a magnetic flux for operating the movable iron core can be sufficiently generated in spite of its small size, and the electromagnetic clutch can be quickly operated.

Further, according to the electromagnetic clutch of the present invention, the first and second projecting pieces of the fixed iron core are extended in the axial direction so as to face each other. Therefore, the area of the mutually opposing surfaces of the movable core and the fixed core increases. Therefore, the magnetic resistance of the magnetic circuit formed by the movable core and the fixed core can be further reduced. In addition, since the first and second projecting pieces extend in the axial direction so as to face each other, the area facing the movable iron core can be increased so as not to increase the size in the axial direction.

According to the electromagnetic clutch of the present invention, the magnetic passage portion of the movable iron core is disposed in the space between the first and second projecting pieces of the fixed iron core and the coil at the non-engagement position. Is done. Therefore, the area of the mutually opposing surfaces of the movable core and the fixed core further increases. Therefore, the magnetic resistance of the magnetic circuit formed by the movable core and the fixed core can be further reduced.

Further, according to the electromagnetic clutch of the present invention, the opposing surfaces of the first and second projecting pieces of the fixed iron core and the magnetic passage portion of the movable iron core are set at the center of rotation of the movable iron core. It is formed on an arcuate curved surface. Therefore, the distance between them can be kept constant, and the change in magnetic flux between them can be stabilized.

Further, according to the electromagnetic clutch of the present invention, the opposing surfaces of the first and second projecting pieces of the fixed iron core and the magnetic passage of the movable iron core are parallel to each other and the rotation of the movable iron core is performed. It was inclined with respect to the axis. Therefore, the area of the mutually opposing surfaces of the movable core and the fixed core further increases. Therefore, the magnetic resistance of the magnetic circuit formed by the movable core and the fixed core can be further reduced.

According to the electromagnetic clutch of the present invention, the first projecting piece of the fixed iron core and the area of the mutually facing surfaces of the magnetic passages of the movable iron core and the second projecting piece of the fixed iron core are movable. The areas of the mutually facing surfaces of the magnetic passage portions of the iron core are set to be equal. Therefore, the magnetic resistance between the first protruding piece and the magnetic path of the movable iron core is equal to the magnetic resistance between the second protruding piece and the magnetic path of the movable iron core. Is the most efficient.

[0017]

Next, an embodiment of the present invention will be described with reference to the drawings. FIG. 1 is a top view showing a movable iron core of an electromagnetic clutch using the present invention in an engagement position.
FIG. 3 is a top view of a movable iron core of the electromagnetic clutch in a disengaged position, and FIG.

Referring to FIG. 1, an electromagnetic clutch 1 according to an embodiment of the present invention mainly includes a shaft disk 2 as an engaged portion, a movable iron core 3, a fixed iron core 4, a coil spring 5 as an urging member, and a coil. 6. This electromagnetic clutch 1 is a device for engaging and disengaging a rotor 71 of a motor 7 having a rotor 71 and a stator 72.

First, the motor 7 comprises a rotating rotor 71 and a non-rotating stator 72. The clutch main body 72a, which is a part of the stator 72, is fixedly provided on a housing 72b made of a magnetic material of the motor 7, and forms a base of the electromagnetic clutch 1. The clutch body 72a is screwed and fixed to the housing 72b from the same direction as the rotor 71 (not shown).

Next, the shaft disk 2, which is the engaged portion, is fixed to a part of the rotor 71, and as shown in FIG. Four recesses 22 are provided at equal intervals.

Next, as shown in FIG. 4, a support pin 31 is fixed on the shaft end face of the clutch body 72a, and the movable iron core 3 is supported so as to be rotatable about the support pin 31. . The movable iron core 3 is formed in a crescent shape in which a plate-like member is bent in a curved shape, a support portion 32 through which the support pin 31 is penetrated and supported by the clutch body 72 a via the support pin 31, and a rotor. The engaging portion 33 is fitted into the concave portion 22 of the shaft disk 2 at 71 and an anti-engaging portion 34 located on the opposite side of the engaging portion 33. The anti-engaging portion 34 is
As shown in FIG. 3, it is formed in a triangular shape that expands in the axial direction toward the end. Also, this movable iron core 3
The center of gravity is formed near the center of the support portion 32. Therefore, even if the clutch body 72a integrated with the motor 7 shakes due to vibration and rotation, the movable core 3 keeps its position stably without rotating by its own weight. Further, since the support portion 32 is formed relatively long in the axial direction, the inclination is small, and the backlash is suppressed small.

Next, a coil spring 5 as an urging member
As shown in FIG. 3, the movable core 3 is wound around a support pin 31 connecting the movable core 3 and the clutch main body 72a, one end is inserted and fixed to the clutch main body 72a, and the other end is connected to the movable core 3a.
Is attached to the back of the arm in the direction of the engaging portion 33. In the coil spring 5, the movable iron core 3 is always in the engagement position shown in FIG.
The movable iron core 3 is constantly biased so as to be positioned in the direction of.

Next, the fixed core 4 has a base 41 formed in a crescent shape bent in a curved shape along the outer periphery of the shaft disk 2 (rotor 7). As shown in the figure, the support pin 31 for supporting the movable iron core 3 is fixed to the clutch main body 72a by a nut 8 or a bolt (not shown) provided at the base end. At the other end of the base 41, a coil support portion 42 extending in the axial direction (parallel to the support pin 31) to support the coil 6 is fixed. The coil support portion 42 has a substantially cylindrical coil bobbin 61.
Is assembled, and a coil winding is wound around the coil bobbin 61 to form the coil 6.

An extension 43 extending parallel to the base 41 is provided at the tip of the coil support 42. Protrusions 41a and 43a that extend in the axial direction and protrude so as to face each other are formed substantially at the center of the base 41 and at the tip of the extension 43. The outer surfaces 41b and 43b of the protruding pieces 41a and 43a are opposed to the distal end surface 34a of the anti-engaging portion 34 of the movable iron core 3 and have a slight gap therebetween. These outer surfaces 41b, 43b and the tip end surface 34a
Are formed along the axial direction.

That is, since the fixed iron core 4 is provided on a part of the shaft disk 2 in the circumferential direction and the coil 6 is configured to extend along the axial direction, the electromagnetic clutch 1 does not protrude in the radial direction and is compact. Can be achieved. In addition, the electromagnetic clutch 1 can be made compact in the circumferential direction. Therefore, a space is formed in the circumferential direction of the electromagnetic clutch 1, and other devices such as a rotation detecting device for detecting the rotation of the motor 7 (rotor 7) can be efficiently disposed in the space.

Since the anti-engaging portion 34 and the projecting pieces 41a and 43a provided at both ends of the coil 6 form a magnetic circuit,
The magnetic circuit can be made short, and the protruding pieces 41a, 4
Since 3a extends in the axial direction to increase the area facing the movable iron core 3, the magnetic resistance can be extremely reduced. As a result, a magnetic flux sufficient to attract the movable iron core 3 can be generated by the small coil 6, and the operation of the electromagnetic clutch 1 can be performed quickly. Further, since the protruding pieces 41a and 43a extend in the axial direction so as to face each other, the area facing the movable iron core 3 can be increased so as not to increase the size in the axial direction.

Further, in the present embodiment, each of the projecting pieces 41 a, 41 a of the projecting piece 41 a, so that the area of the projecting piece 41 a of the base 41 facing the movable core 3 is equal to that of the projecting piece 43 a of the extension 43.
The size of 43a is set. Therefore, the magnetic resistance between the projecting piece 41a of the base 41 and the movable core 3 is equal to that of the projecting piece 43a of the extension 43, so that the magnetic balance between them is good and the efficiency is the highest.

The tip end surface 34a of the anti-engaging portion 34 and the outer surfaces 41b, 43b of the projecting pieces 41a, 43a are
The movable iron core 3 has an arcuate curved surface centered on the center of rotation. Therefore, even if the movable core 3 rotates, the distance between the distal end surface 34a of the anti-engaging portion 34 and the outer surfaces 41b, 43b of the projecting pieces 41a, 43a can be kept constant.
Therefore, the tip end surface 34a of the anti-engaging portion 34 and the projecting piece 41
A change in magnetic flux between the outer surfaces 41b and 43b of the a and 43a can be stabilized.

The projecting piece 41a of the base 41 and the movable core 3
A thin portion 41c that is thinner than the plate thickness of the base 41 on the coil 6 side is provided between the support pin 31 and the support pin 31 that supports the coil 6. That is, the magnetic resistance of this portion is increased by the thin portion 41c, and the protruding piece 41a is closer to the support pin 31, that is, the fixed core 4
Magnetic flux leakage to a part other than the magnetic circuit formed by the (protruding pieces 41a, 43a and the support part 42) and the movable iron core 3 (anti-engagement part 34) is suppressed to a small level.

As shown in FIGS. 1 and 2, when the movable iron core 3 is attracted to the projecting pieces 41 a, 43 a of the fixed iron core 4 by the excitation of the coil 6, The movable core 3 contacts the inner peripheral surface of the movable core 3
A stopper 44 is provided for positioning at a non-engaging position shown in FIG. Therefore, by providing such a stopper 44, the movable core 3 can be reliably stopped at the non-engagement position.

Next, the operation will be described. FIG. 1 shows a state in which the movable core 3 of the embodiment of the present invention is located at the engagement position, and FIG. 2 shows a state in which the movable core 3 is similarly located at the non-engagement position.

FIG. 1 shows a state in which no current is flowing through the coil 6. If no current flows through the coil 6, no electromagnet action is generated between the coil 6 and the fixed iron core 4. As a result, since the movable iron core 3 and the fixed iron core 4 do not attract each other due to the magnetic force, the movable iron core is brought into a state in which the engaging portion 33 is engaged with the concave portion 22 of the rotor 71 by the urging force of the coil spring 5. Even if the motor 7 is operated in this state,
Since the protrusion 21 of the rotor 71 comes into contact with the engaging portion 33 in the circumferential direction, the rotor 71 does not move. Also,
When the electric system including the power supply to the motor 7 fails, no current flows through the coil 6, so that the motor 7 does not operate and is set to a stop state so as to stop.

FIG. 2 shows a state in which a current is flowing through the coil 6. When a current flows through the coil 6, an electromagnet action is generated between the coil 6 and the fixed iron core 4. As a result, the movable core 3 (the anti-engaging portion 34) and the fixed core 4 (the protruding pieces 41a, 43a) are attracted by magnetic force, and the movable core 3
Is in a state where the engaging portion 33 is separated from the concave portion 22 of the rotor 71 and is disengaged against the urging force of the coil spring 5. When the motor 7 is operated in this state, the protrusions 21 of the rotor 71 do not abut against the engaging portions 33 in the circumferential direction, so that the rotor 71 can rotate freely.

Next, the state when the state of FIG. 1 changes to the state of FIG. 2 will be described. In the state of FIG. 1, no current is flowing through the coil 6, and the movable iron core 3 is in a state where the engaging portion 33 is engaged with the concave portion 22 of the rotor 71 by the urging force of the coil spring 5. Thereafter, when it is desired to operate the motor 7, an electric current is supplied to the winding of the rotor 71 of the motor 7. At the same time, current flows through the coil 6. As a result, an electromagnet action is generated in the fixed core 4, and the engaging portion 33 of the movable core 3 is
Move away from the concave portion 22 of the rotor 71, and the movable iron core 3 becomes the non-engagement position. At the same time, the rotor 71 of the motor 7 starts rotating.

Next, the state when the state of FIG. 2 changes to the state of FIG. 1 will be described. In the state shown in FIG. 2, a current is flowing through the coil 6, and the movable core 3 is in a state where the engaging portion 33 is separated from the concave portion 22 of the rotor 71 and disengaged against the urging force of the coil spring 5. . Thereafter, when the motor 7 is to be stopped, the current is stopped in the winding which is the rotor 71 of the motor 7. At the same time, the current is stopped in the coil 6. As a result, the electromagnet function of the fixed core 4 is eliminated, and the engaging portion 3 of the movable core 3 is
3 is inserted into the concave portion 22 of the rotor 71, and the engaging portion 3
3 comes into contact with the protrusion 21 in the circumferential direction, and the rotor 71 is suddenly stopped. Here, the moving direction of the engaging portion 33 from the non-engaged state to the engaged state is along the radial direction of the rotor 71.
When the 3 is inserted into the concave portion 22, the rotor 71 easily enters smoothly in either rotation direction.

The electromagnetic clutch 1 and the motor 7
Is used, for example, in the vehicle steering system 10 shown in FIG. That is, the vehicle steering system 10 includes an upper steering shaft 102 connected to a steering wheel 101.
A variable gear ratio unit 104 is interposed between the lower steering shaft 103 and the lower steering shaft 103.

The lower steering shaft 103 has a pinion (not shown) at its lower end, and the pinion is meshed with a rack 106 in the steering gear box 105. When the steering wheel 101 is operated, both shafts 102 and 103 and the variable gear ratio unit 104 rotate, and the rack 10 of the gear box 105 is rotated.
6 moves left and right, and steered wheels (not shown) operate (steering)
It is supposed to.

The variable gear ratio unit 104 includes the motor 7, the electromagnetic clutch 1, and a planetary speed reduction mechanism 107, and is integrally mounted on a substantially cylindrical housing 108. A rotor 71 of the motor 7 is connected to a lower end of the upper steering shaft 102 via a speed reduction mechanism 107, and a stator 72 of the motor 7 is connected to an upper end of the lower steering shaft 103.

The motor 7 and the electromagnetic clutch 1 are controlled by the controller C. Here, when the motor 7 is driven, the coil 6 of the electromagnetic clutch 1 is energized,
The rotor 71 of the motor 7 and the movable iron core 3 (stator 72) are disengaged, that is, the rotor 71 is set in a free state. Then, based on the driving of the motor 7 controlled by the controller C, the rotation ratio (gear ratio) of the lower steering shaft 103 with respect to the upper steering shaft 102 is appropriately changed, and the driving state of the vehicle is added to the operation of the steering wheel 101. The steering angle is adjusted.

On the other hand, when the motor 7 is not driven, the energization of the coil 6 of the electromagnetic clutch 1 is stopped, and the rotor 71 of the motor 7 and the movable iron core 3 (stator 72) are engaged. Therefore, the upper steering shaft 102 is directly connected to the lower steering shaft 103, and the steering angle is determined according to only the operation of the steering wheel 101.

It should be noted that the steering shaft 10
When the shafts 102, 103 rotate, the shafts 102, 103
At the same time, the variable gear ratio unit 104 (electromagnetic clutch 1) rotates. In such a case, since the movable iron core 3 of the electromagnetic clutch 1 is supported by its center of gravity, even if the electromagnetic clutch 1 itself rotates, the movable iron core 3 does not rotate under its own weight and its position is stably maintained. Will be maintained. Therefore, malfunction due to rotation of the electromagnetic clutch 1 itself can be prevented.

This embodiment may be modified as follows. In the above embodiment, the distal end surface 34a of the anti-engaging portion 34 of the movable core 3 and the outer surfaces 41b of the projecting pieces 41a, 43a
43b is opposed, but as shown in FIG. 5, the anti-engaging portion 34 and the other surfaces of the projecting pieces 41a, 43a may be opposed to each other. That is, in the embodiment shown in FIG. 5, the anti-engaging portion 34 of the movable core 3 is
It is arranged in the space between the coils 1a and 43a and the coil 6. By doing so, the area of the mutually opposing surfaces of the movable core 3 and the fixed core 4 increases. Therefore, the magnetic resistance of the magnetic circuit formed by the movable core 3 and the fixed core 4 can be further reduced.

As shown in FIG. 5, the projecting pieces 41a,
The inner surfaces 41d and 43c of the 43a and the inner surfaces 34b and 34c of the anti-engaging portion 34 are parallel to each other and inclined with respect to the rotation axis of the movable core 3. Therefore, the area of the opposing surfaces of the movable core 3 and the fixed core 4 further increases. Therefore,
The magnetic resistance of the magnetic circuit formed by the movable core 3 and the fixed core 4 can be further reduced. Although not shown, the inner surfaces 41d, 43c of the projecting pieces 41a, 43a are not shown.
And the inner side surfaces 34b and 34c of the anti-engaging portion 34 are formed as arcuate curved surfaces centered on the rotation center of the movable iron core 3.

As shown in FIG. 6, the projecting pieces 41a and 43a of the fixed iron core 4 and the anti-engaging portion 34 of the movable iron core 3 may be formed by press molding. By doing so, the movable core 3 and the fixed core 4 can be formed more easily.

In the above embodiment, the anti-engaging portion 34 provided on the end of the movable iron core 3 on the side opposite to the engaging portion 33 is a magnetic passage portion, but the magnetic passage portion is provided on the engaging portion 33 side. You may.

In the above embodiment, the protruding pieces 41a and 43a of the fixed iron core 4 are formed so as to protrude so as to oppose each other in the axial direction. However, the shape is not limited to this. It may be changed as appropriate.

In the above embodiment, in order to stop the movable core 3 at the predetermined non-engagement position shown in FIG. 2, the distal end of the extension 43 is brought into contact with the inner peripheral surface of the non-engagement portion 34 of the movable core 3. Although the stopper 44 that makes contact is formed, for example, a stopper that contacts the inner peripheral surface of the anti-engaging portion 34 may be formed on the base 41. In addition, stoppers may be provided on both the extension 43 and the base 41. Further, a stopper may be provided on the movable iron core 3. Further, the stopper 44 may be omitted.

In the above embodiment, the movable iron core 3 is supported near the center of gravity, but may be supported at other places. Further, the shape of the movable core 3 may be appropriately changed.

In the above embodiment, the coil spring 5 is used as the urging member for urging the movable iron core 3, but other urging members may be used. In the above embodiment, the electromagnetic clutch 1 is used for the vehicle steering device 10, but may be used for other devices.

Next, technical ideas other than those described in the claims which can be understood from the above embodiment and other examples will be described below together with their effects. (A) The electromagnetic clutch according to any one of claims 1 to 6, wherein the movable iron core (3) is supported near its center of gravity. With this configuration, since the movable core is provided near the position where the center of gravity of the movable core is supported, even if the stator that is the motor body vibrates (rotates), the movable core loses balance due to the change in the center of gravity and rotates. Without stopping, the final stop position can always be maintained. Therefore,
Malfunction due to vibration can be prevented.

(B) At least one of the fixed iron core (4) and the movable iron core (3) includes the movable iron core (3).
The electromagnetic clutch according to any one of claims 1 to 6, wherein a stopper (44) for stopping the motor at a predetermined non-engagement position is provided. With this configuration, at least one of the fixed iron core and the movable iron core includes:
Since the stopper for stopping the movable core at the predetermined non-engagement position is provided, the movable core can be reliably stopped at the predetermined non-engagement position.

(C) Claims 1 to 6, (a),
The electromagnetic clutch (1) according to any one of (b) is provided in a variable gear ratio unit (104) interposed between the upper and lower steering shafts (102, 103) of the vehicle steering system (10). An electromagnetic clutch for a steering device for a vehicle. With this configuration, it is possible to obtain an electromagnetic clutch for a vehicle steering system that can be quickly operated while reducing the size.

[0053]

As is apparent from the above description, according to the present invention, it is possible to provide an electromagnetic clutch which can be miniaturized and which can operate quickly.

[Brief description of the drawings]

FIG. 1 is a plan view showing an engagement position of an electromagnetic clutch according to an embodiment of the present invention.

FIG. 2 is a plan view showing a disengaged position of the electromagnetic clutch according to the embodiment of the present invention.

FIG. 3 is a side view of the electromagnetic clutch according to the embodiment of the present invention.

FIG. 4 is a schematic view of a vehicle steering system using an electromagnetic clutch according to an embodiment of the present invention.

FIG. 5 is a plan view showing another example of an electromagnetic clutch.

FIG. 6 is a plan view showing another example of an electromagnetic clutch.

[Explanation of symbols]

DESCRIPTION OF SYMBOLS 1 ... Electromagnetic clutch, 2 ... Shaft disk as engaged part, 3 ...
Movable iron core, 33 engaging part, 34 anti-engaging part as magnetic path part, 34a distal end face as opposing surface, 34b, 3
4c: inner surface as opposed surface, 4: fixed iron core, 41a ...
Projecting piece as a first projecting piece, 41b ... Outer face as opposing face, 41d ... Inner face as opposing face, 42 ... Coil support part, 43a ... Projecting piece as second projecting piece, 43b ... Outer side surface, 43c ... inner side surface as opposed surface,
5 ... Coil spring as urging member, 6 ... Coil,
7 ... motor, 71 ... rotor, 72 ... stator.

Claims (6)

[Claims] An electromagnetic clutch (1) that engages and disengages with a rotor (71) of a motor (7) comprising a stator (72) and a rotor (71), wherein the rotor (71) ), An engaging portion (33) engaged with the engaged portion (2), and a magnetic path portion (34) provided at a predetermined position, and A movable iron core (3) supported by the stator (72) so as to be rotatable to an engagement position or a non-engagement position with respect to the child (71); A first protruding piece (41a) provided so as to face one side of the magnetic path portion (34) in the axial direction at the non-engagement position; and a coil support extending in the axial direction from the first protruding piece (41a). Department (4
2) and the first projecting piece (4) of the coil support portion (42).
A second protruding piece (43a) is provided on the side opposite to 1a) so as to face the other side in the axial direction of the magnetic path portion (34), and forms a magnetic circuit together with the movable iron core (3). A fixed core (4); a biasing member (5) for biasing the movable core (3) to the engagement position; and a coil support (42) of the fixed core (4). Moving the movable core (3) to the urging member (5)
And a coil (6) that is attracted against and disposed at the disengaged position. 2. The electromagnetic device according to claim 1, wherein the first and second projecting pieces (41a, 43a) of the fixed iron core (4) extend in the axial direction so as to face each other. clutch. 3. A space is provided between the first and second projecting pieces (41a, 43a) of the fixed core (4) and the coil (6), and the space is provided in the space at the non-engagement position. 3. The electromagnetic clutch according to claim 2, wherein a magnetic passage (34) of the movable core (3) is arranged. 4. A facing surface (34a-34c, 41b, 41) between first and second projecting pieces (41a, 43a) of the fixed iron core (4) and a magnetic passage part (34) of the movable iron core (3).
The electromagnetic clutch according to any one of claims 1 to 3, wherein (d, 43b, 43c) is an arcuate curved surface centered on the rotation center of the movable iron core (3). 5. An opposing surface (34b, 34c, 41d, 43) of the first and second projecting pieces (41a, 43a) of the fixed core (4) and the magnetic passage portion (34) of the movable iron core (3).
The electromagnetic clutch according to any one of claims 1 to 4, wherein c) is parallel to each other and inclined with respect to a rotation axis of the movable iron core (3). 6. A first projecting piece (41) of said fixed iron core (4).
a) and the areas of the mutually facing surfaces (34a, 34b, 41b, 41d) of the magnetic passage portion (34) of the movable core (3), the second projecting piece (43a) of the fixed core (4) and the The electromagnetic field according to any one of claims 1 to 5, wherein the mutually facing surfaces (34a, 34c, 43b, 43c) of the magnetic passage portions (34) of the movable iron core (3) are made equal. clutch.