JPH09229093A - Electromagnetic coupling device - Google Patents

Abstract

(57) [Abstract] [Problem] Responsiveness to energization of an exciting coil is good,
It is possible to obtain an electromagnetic coupling device which has less noise due to the collision of armatures and at the same time has good productivity. A drive connecting member (2) is loosely fitted to an output shaft (1).
and a gear 2 for inputting rotation having b, fixed to the output shaft 1 in the rotational direction and movably in the axial direction.
A connecting member 3b that meshes with the driving connecting member 2b, and a rotor 3 having a plurality of engaging projections 3c on different radii;
A yoke 5 having a plurality of arcuate elongated holes 5c which constitute a magnetic path and engage with the engaging protrusions 3c of the rotor, and an exciting coil 7.
And a bobbin 20 holding an armature 8 for moving the rotor 3 in the axial direction by the excitation coil 7 and an extension 20b thereof, and a spring mounted between the rotation input gear 2 and the rotor 3. 4, armature 8 and bobbin 20
And a cushioning member integrally formed with the substrate 21a and the foamed rubber 21b.

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention is an electromagnetic coupling interposed between a rotary power source and a load to transmit and block rotation and, when blocking rotation, stop an output shaft at a fixed position in the rotation direction. It relates to the device.

[0002]

2. Description of the Related Art FIG. 11 shows a structure of a conventional electromagnetic coupling device, in which 1 is an output shaft of the electromagnetic coupling device and 2 is an output shaft of the electromagnetic coupling device.
Is rotatably fitted to the output shaft 1 and is a gear for rotation input which is connected to a power source. 3 is a spline 1 a on the output shaft 1.
Is a rotor that is fixed in the rotation direction and is attached so as to be movable in the axial direction, and the gear 2 is connected to the drive connecting member 2b.
However, the rotor 3 is provided with a driven connecting member 3b that engages with the driving connecting member 2b of the gear 2, and the gear 2
A spring 4 is provided between the rotor 3 and the rotor 3 and urges the springs 4 in a direction in which they are separated from each other. Reference numeral 5 is a yoke forming a magnetic circuit, 6 is a bobbin having an exciting coil 7, 8 is an armature made of a magnetic material loosely fitted in an extension 6a of the bobbin 6, and these are configured to be rotatable with respect to the output shaft 1. It is fixed to a frame (not shown) by a holder 9 provided on the yoke 5, and the axial position of the output shaft 1 is maintained by the step portion 1b, the spacer 10 and the retaining ring 11.
The armature 8 is loosely fitted to the outer periphery of the extension 6a of the bobbin 6 so as to be movable in the axial direction, and the spacer 10 prevents the armature 8 from dropping off. It is configured to abut the end surface 3a of the. Reference numeral 3c denotes a plurality of engaging projections provided on the rotor 3, and 5c is a plurality of arcuate elongated holes provided on the yoke 5, which are located at corresponding positions and have different radii. It is provided on the circumferential track, and the specific engagement projection is configured to be engageable only with the specific arcuate elongated hole. Reference numeral 12 is a shock-absorbing sponge sheet attached to the armature 8.

In the electromagnetic coupling device constructed as described above, when the exciting coil 7 is not energized, the rotor 3 is pushed by the spring 4, and the engaging projection 3c is formed in the arc-shaped elongated hole 5 of the yoke 5.
The gear 2 and the rotor 3 are engaged with each other c to be in the most separated state, and the drive coupling member 2b of the gear 2 and the driven coupling member 3b of the rotor 3 are in the disengaged state. When the exciting coil 7 is energized, the yoke 5 is excited and attracts the armature 8, and the armature 8 holds the rotor 3 with the spring 4 by its claw portion 8a.
Since it is moved to the gear 2 side against the pressing force of, the engagement projection 3c and the arcuate elongated hole 5c are disengaged, and the drive connecting member 2b and the driven connecting member 3b engage and rotate. The child 3 is driven by the gear 2, and the rotor 3 drives the output shaft 1 via the spline 1a. When the current of the exciting coil 7 is cut off, the pressing force of the spring 4 causes the rotor 3 to move to the yoke 5 side while pressing the armature 8, and the engaging projection 3 of the rotor 3
When c rotates while sliding on the yoke 5, and the engaging projection 3c engages with the arcuate elongated hole 5c of the yoke 5, the rotor 3
Stops. Since the engagement projections 3c and the arc-shaped elongated holes 5c are provided at a plurality of positions corresponding to the circular orbits having different radii, the particular engagement projection can be engaged only with the particular arc-shaped elongated hole. Yes, the rotor 3 and the output shaft 1 therefore stop at a fixed position in the direction of rotation.

[0004]

In the electromagnetic coupling device operating in this way, the driving coupling member 2b and the driven coupling member 3b for energization and current interruption of the exciting coil 7 are used.
It is required that the responsiveness of engagement and disengagement of the armature 8 is fast. Therefore, when the exciting coil 7 is energized, the armature 8
However, there is a problem in that the speed of collision with the yoke 5 also increases and a violent collision noise is generated. In order to eliminate this collision noise, the conventional device has a treatment of attaching a sponge sheet 12 as a cushioning member to the armature 8. However, in order to obtain a sufficient muffling effect, it is necessary to increase the thickness of the sponge sheet 12 and load the sponge sheet 12 in a compressed state between the armature 8 and the bobbin 6, which causes a blocking force in the movement of the armature 8. As a result, there is a contradiction that the moving speed decreases and the responsiveness deteriorates.

The present invention has been made in order to solve the above problems, and does not deteriorate responsiveness.
It is an object of the present invention to obtain an electromagnetic coupling device that can effectively eliminate the collision noise and at the same time improve the productivity.

[0006]

In an electromagnetic coupling device according to the present invention, a drive portion is loosely fitted to an output shaft and is rotated by being driven by a power source. A driven part having an engaging part that is movably mounted on the shaft, a yoke having an engaging part that engages with the engaging part of the driven part, and the driven part in the axial direction via an armature when biased. An exciter that moves and couples the drive part and the driven part, a spring that is mounted between the drive part and the driven part, and urges them in a direction of separating them, and these between the armature and the exciter. And a cushioning member disposed with a gap therebetween.

Further, the bending amount of the cushioning member due to the movement of the armature is set smaller than the axial movement distance of the armature. The cushioning member is provided with a hard thin plate serving as a substrate and foamed rubber having closed cells. Further, a rib-shaped projection is provided on the end surface of the exciting device, and the rib-shaped projection serves as a contact surface for the foamed rubber of the cushioning member. Further, the cushioning member is integrally formed on one or both of the armature and the end surface of the exciter.

The cushioning member is a spring member in which the amount of bending due to the movement of the armature is smaller than the axial movement distance of the armature. The cushioning member is formed by bending a part of the armature into a leaf spring shape. Further, the cushioning member is formed by forming a part of the end surface of the exciting device into a leaf spring shape. Further, the cushioning member is one in which a leaf spring is integrally formed with a spacer that regulates the positions of the yoke and the exciter, and the leaf spring is interposed between the armature and the exciter. The cushioning member is a leaf spring that is sandwiched between a spacer that restricts the positions of the yoke and the exciter and the exciter, and has a tip disposed between the armature and the exciter.

[0009]

BEST MODE FOR CARRYING OUT THE INVENTION

Embodiment 1. 1 is a sectional view showing an embodiment of an electromagnetic coupling device according to the present invention, FIG. 2 is a partially enlarged view of a cushioning member mounting portion of FIG. 1, and FIG. 3 is a plan view showing a shape of an end surface of a bobbin of FIG. FIG. 4 is a characteristic comparison diagram between the electromagnetic coupling device according to the present invention and the conventional example. In FIG. 4, 1 to 5 and 7 to 11 are shown.
Has the same configuration as the above-mentioned conventional example. In this embodiment, a bobbin 20 that constitutes an exciting device together with the exciting coil 7 has a plurality of rib-shaped projections 20a and an extended portion 20b that is divided into a plurality of portions as shown in FIGS. Is provided, and the armature 8 is provided in the extension portion 20b.
Is loosely fitted. The inner diameter portion of the armature 8 is shaped so as to be loosely fitted to the outer surface 20c and the side surface 20d of the extension portion 20b, so that the armature 8 can move only in the axial direction. End face of bobbin 20 and armature 8
An annular cushioning member 21 is fitted between the cushioning member 21 and the cushioning member 21.
As shown in FIG. 2, a hard substrate 21a made of, for example, a thin steel plate or a plastic plate, and a foamed rubber 21b having closed cells on both sides thereof are attached to each other, and the armature 8 of the total thickness B is Move to the end face 5 of the yoke 5.
The dimension L, which is the bending margin when abutting on a, is set to be smaller than the gap A between the armature 8 and the end surface 5a of the yoke 5 when the exciting coil 7 is not energized, that is, the moving distance of the armature 8. .

In the electromagnetic coupling device according to this embodiment having the above-described structure, when the armature 8 is moved by the excitation of the exciting coil 7, the movement blocking force at the initial stage of movement is not present except for the spring 4, so that the response is obtained. The movable connecting member 3b of the rotor 3 is meshed with the driving connecting member 2b of the rotation input gear 2 so that the armature 8 abuts on the cushioning member 21 immediately before the armature 8 collides with the yoke 5 to move it. The cushioning member 21 made of foamed rubber that is bent and has an appropriate hardness sharply suppresses the moving speed of the armature 8 and reduces the noise of collision with the yoke 5. FIG. 4 shows changes in the movement blocking force of the buffer member 21 with respect to the movement of the armature 8. In the conventional device, as shown by the solid line in the figure, the blocking force of the buffer member works from the initial stage of movement to delay the moving speed, while the yoke moves. According to the present invention, the blocking force at the time of collision with 5 does not increase greatly, while according to the present invention, the blocking force is provided by the cushioning member while moving a certain distance, that is, the distance AL in FIG. The force does not work, and the blocking force increases rapidly during the subsequent movement of the distance L, which results in a highly responsive operation and a large silencing effect. Further, this blocking force can be adjusted by changing the width of the rib-shaped projection 20a of the bobbin 20. Further, the buffer member 21 may be a divided member instead of an annular shape.

Embodiment 2. Foam rubber 2 of cushioning member 21
Even if 1b is provided only on one surface of the bobbin side, a more effective sound deadening effect can be obtained as compared with the conventional device.
The same effect can be obtained by substituting the hard substrate 21a of No. 1 for the side surface of the bobbin 20 or the armature 8 and attaching the foam rubber to either the side surface of the bobbin 20 or the armature 8 or both.

Embodiment 3. FIG. 5 shows a third embodiment of the present invention, in which a buffer member using a spring is used instead of the buffer member 21 using the hard substrate and foam rubber integrated with the hard substrate of the first and second embodiments. Is. FIG. 5 shows a cushioning member 22 made of a leaf spring mounted between the bobbin 20 and the armature 8. The deflection amount L of the leaf spring 22 at the time of cushioning is set smaller than the moving distance of the armature 8 as in the first embodiment. By doing so, the characteristics shown by the broken line in FIG. 4 are obtained, and the same responsiveness and silencing effect as in Embodiment 1 can be obtained.

Embodiment 4 In FIG. 6, a part of the armature 8 is bent and bent into a thin plate shape between the armature 8 and the bobbin 20 to form a leaf spring-shaped cushioning member 23.
In this case, since the buffer member 23 moves together with the armature 8, the deflection L is obtained by subtracting the gap N between the tip of the buffer member and the bobbin from the moving distance A of the armature 8.
By setting the dimension L to be smaller than the moving distance of the armature 8, the same responsiveness and noise reduction effect as those of the first embodiment can be obtained, and at the same time, the number of constituent parts can be reduced and the productivity can be improved. is there.

Embodiment 5 7 and 8 show the bobbin 2
When 0 is formed, a leaf spring which is the same material as the bobbin 20 and serves as a buffer member is integrally formed. 7 shows a leaf spring-shaped cushioning member 23 projecting from the side surface of the bobbin 20 between the bobbin 20 and the armature 8. FIG. 8 shows a leaf spring-like cushioning member 23 integrally formed with the extension 20a of the bobbin 20. Is extended between the bobbin 20 and the armature 8, both of which are intended to improve productivity by reducing the number of parts while obtaining responsiveness and a sound deadening effect.

Embodiment 6. FIG. 9 shows an embodiment in which a leaf spring-shaped cushioning member 23 is formed integrally with the spacer 10, and FIG. 10 shows an embodiment in which a leaf spring-like cushioning member 23 is attached between the spacer 10 and the extension portion 20 a of the bobbin 20. In each of the embodiments, a cushioning member 23 is interposed between the bobbin 20 and the armature 8 through the cutout portion of the armature 8, and it is possible to improve the responsiveness and the silencing effect as compared with the conventional device. It is a thing.

Although each of the above-described embodiments describes a device that stops at one fixed position in the rotational direction, a device that stops at a plurality of fixed positions in the rotational direction (for example, three positions, one position).
It can also be applied to a device that stops every 20 °. in this case,
The protrusion 3C for engagement of the rotor and the arc-shaped elongated hole 5C of the yoke are provided on a circular orbit of the same radius (every 120 ° in this example). Further, the engagement relationship between the protrusion and the long hole is not specific. The arc-shaped elongated hole is not limited to the arc-shaped elongated hole because the engaging projection may be fitted therein.

[Brief description of drawings]

FIG. 1 is a sectional view showing a configuration of an electromagnetic coupling device according to a first embodiment of the present invention.

FIG. 2 is a sectional view showing details of a cushioning member mounting portion according to the first embodiment of the present invention.

FIG. 3 is a plan view of a cushioning member mounting portion of the bobbin according to the first embodiment of the present invention.

FIG. 4 is a characteristic diagram showing a difference in characteristics between the present invention and a conventional device.

FIG. 5 is a sectional view showing a third embodiment of the present invention.

FIG. 6 is a sectional view showing a fourth embodiment of the present invention.

FIG. 7 is a sectional view showing Embodiment 5 of the present invention.

FIG. 8 is a sectional view showing Embodiment 5 of the present invention.

FIG. 9 is a sectional view showing a sixth embodiment of the present invention.

FIG. 10 is a sectional view showing a sixth embodiment of the present invention.

FIG. 11 is a cross-sectional view showing a configuration of a conventional electromagnetic coupling device.

[Explanation of symbols]

DESCRIPTION OF SYMBOLS 1 output shaft, 2 rotation input gear, 2b drive connecting member, 3 rotor, 3b driven connecting member, 3c engaging protrusion, 4 spring, 5 yoke, 5c arcuate elongated hole, 7
Excitation coil, 8 armature, 20 bobbin, 20
a rib-like protrusion, 20b extension, 21 cushioning member,

Claims (10)

[Claims] 1. A drive unit which is loosely fitted to an output shaft and is rotated by being driven by a power source, and an engagement unit which is rotatably coupled to the output shaft and movably mounted in the axial direction. A driven part, a yoke having an engaging part that engages with an engaging part of the driven part, and an excitation for coupling the driving part and the driven part by axially moving the driven part via an armature when energized. A device, a spring that is mounted between the driving part and the driven part and urges them in a direction to separate them, and a space is provided between the armature and the exciting device with respect to at least one of them. And an electromagnetic coupling device. 2. The electromagnetic coupling device according to claim 1, wherein the amount of bending of the buffer member due to the movement of the armature is set to be smaller than the axial movement distance of the armature. 3. The electromagnetic coupling device according to claim 1, wherein the cushioning member includes a hard thin plate serving as a substrate and foamed rubber having closed cells. 4. The electromagnetic coupling device according to claim 3, wherein a rib-shaped projection is provided on an end surface of the exciting device, and the rib-shaped projection serves as a contact surface for the foamed rubber of the cushioning member. 5. The electromagnetic coupling device according to claim 1, wherein the cushioning member is integrally formed on one or both of the armature and the end surface of the exciter. . 6. The electromagnetic coupling device according to claim 1, wherein the cushioning member is a spring member in which the amount of bending due to the movement of the armature is smaller than the axial movement distance of the armature. 7. The buffer member is formed by bending a part of an armature into a leaf spring shape.
Alternatively, the electromagnetic coupling device according to claim 6. 8. The shock-absorbing member is formed by forming a part of an end surface of the exciting device into a leaf spring shape.
Alternatively, the electromagnetic coupling device according to claim 6. 9. The shock-absorbing member is characterized in that a leaf spring is integrally formed with a spacer that regulates the positions of the yoke and the exciter, and the leaf spring is interposed between the armature and the exciter. Alternatively, the electromagnetic coupling device according to claim 6. 10. The cushioning member is a leaf spring which is sandwiched between a spacer for regulating the positions of the yoke and the exciter and the exciter, and whose tip is disposed between the armature and the exciter. The electromagnetic coupling device according to claim 1 or claim 6.