JP2001200867A - Electromagnetic clutch having braking function - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide a small electromagnetic clutch being built in a clutch body, miniaturizing the constituting of a permanent magnet for a brake having a large occupying rate to the clutch body and being suitable for any OA such as a copier. SOLUTION: A braking magnet body 11 is arranged as an armature corresponding member for an ordinary electromagnetic brake without incorporating a permanent magnet 11a for obtaining a braking magnetic flux into the clutch body, and when bearing the clutch-armature motive power transmitting action, a magnetic flux is generated for offsetting a magnetic flux generated from the braking magnet body 11, and is constituted so as to obtain braking force by the magnetic flux from the braking magnet body 11 according to a relase of current-carrying of a built-in coil. Thus, the various constitution shown in a drawing 1 to a drawing 7 can be supposed.

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to an electromagnetic clutch having a braking function suitable for use in office automation equipment such as a copying machine and a printer.

[0002]

2. Description of the Related Art Generally, an electromagnetic clutch has an ON operation for transmitting a torque on a driving side at a constant speed to a driven side and an OFF operation for interrupting the transmission of torque from the driving side to the driven side. In both the ON and OFF operations, especially when the operation shifts from the ON operation to the OFF operation, the inertia of the driven side tends to increase the stop time until the driven side stops, and there is a problem in responsiveness. Such lack of responsiveness of the electromagnetic clutch causes the ON and OFF operations to be performed at a high frequency.
O which is required to shift from operation to OFF operation promptly
A problem arises in the electromagnetic clutch for the A-apparatus, and therefore, improvement has been demanded.

[0003] As one of measures against this, for example, when the exciting coil is excited (when the clutch is ON), the magnetic flux of a built-in permanent magnet that performs a braking action is applied, as in the technique disclosed in Japanese Utility Model Publication No. 1-340353. To stop the braking action and demagnetize the exciting coil (clutch off)
In the above, a technique has been developed in which the magnetic flux from the built-in permanent magnet is utilized as it is, and a braking action is obtained in conjunction with the clutch OFF operation.

[0004]

By the way, in the prior art, the permanent magnet for brake is built in the clutch body, and the space factor of the permanent magnet for brake with respect to the clutch body is large. There was a tendency to change. Accordingly, there is a tendency that the electromagnetic clutch is particularly limited in application to OA equipment such as a printer and a copying machine which requires a reduction in size. Further, in the prior art, a leaf spring was provided as a brake armature releasing means for releasing the braking action of the brake mechanism.However, the mounting structure of the leaf spring became complicated, and in order to make the braking action appropriate, There is a problem that it is necessary to adjust the leaf spring. An object of the present invention is to provide an electromagnetic clutch having a braking function that solves the above-mentioned problems (problems) of the conventional one.

[0005]

According to the present invention, there is provided an electromagnetic clutch having a braking function, wherein a sleeve, a rotor, a boss, and a driven member in which the sleeve, the rotor, and the boss are sequentially and integrally fixed. A shaft, a clutch armature support that is rotatably supported with respect to the sleeve and that is provided to be rotated by external power, is disposed between the clutch armature support and the rotor, and is disposed on the clutch armature support side. A clutch armature supported by the clutch armature support via a spring that operates in a displacing direction; a detent means for fixing and supporting the boss; and a protruding portion on the anti-clutch armature side of the coil bobbin. An outer shell disposed opposite to the protrusion of the boss with a gap therebetween, and an excitation coil therein. The outer peripheral side is fixed to the outer shell, and an annular coil bobbin made of a non-magnetic material for rotatably supporting the boss is provided on each outer surface of the projecting portion of the outer shell and the projecting portion of the boss. A braking magnet body having opposing surfaces, wherein each of the opposing surfaces of the braking magnet body has the same polarity as the polarity appearing in the protrusion of the outer shell and the protrusion of the boss by excitation of the excitation coil. And a braking magnet that is supported by the boss so as to be movable in the axial direction of the driven shaft.

According to the second aspect, the first aspect is provided.
The described detent means of the coil bobbin is constituted by a plurality of arms extending outward from the coil bobbin, and a stationary member which engages with these arms and prevents detent.

[0007] According to the third aspect, the second aspect is provided.
A power supply line for the excitation coil housed in the coil bobbin is housed in one of the plurality of arms described.

[0008] According to the fourth aspect, the first aspect is provided.
A permanent magnet magnetized in different polarities on the inner and outer peripheral surfaces of the braking magnet body according to any one of claims 1 to 3, and an annular body made of a magnetic material on each magnetic pole surface of the permanent magnet. Were joined.

According to a fifth aspect of the present invention, a means for moving the braking magnet body according to any one of the first to fourth aspects with respect to the boss in the axial direction of the driven shaft is provided on an inner peripheral edge portion. The legs of the pin having a head and a leg are loosely fitted at at least three places located at substantially equal intervals, the tip of the leg is fixed to the boss, and the pin moves between the head and the boss. It was configured to support as much as possible.

[0010]

BRIEF DESCRIPTION OF THE DRAWINGS FIG. 1 is a perspective view showing an electromagnetic clutch having a braking function according to the present invention. FIG. 1 is a half longitudinal sectional side view in a magnetic coupling state, and FIG. 2 is a half longitudinal sectional side view in a braking state. In each of the figures, reference numeral 1 denotes a driven shaft, in which a sleeve 2, a rotor 3, and a boss 4 are sequentially fitted with a key (not shown) using a key groove or the like to prevent rotation. Reference numeral 5 denotes a clutch armature support, which is rotatably supported on the sliding surface 2a of the sleeve 2. The clutch armature support 5 has a gear 5a on the outer peripheral side for receiving power transmission. Reference numeral 6 denotes a clutch armature, which is supported by a clutch armature support 5 via a spring means (hereinafter simply referred to as a spring) 7 such as a leaf spring. The operating force of the spring 7 acts in the direction of forming the gap G1 when no magnetic attraction force acts between the clutch armature 6 and the rotor 3 (see FIG. 2).

The rotor 3 has a groove 3a for forming a magnetic path and a non-magnetic portion 3b on a part of the surface facing the clutch armature 6, and the other part is made of a magnetic material. On the opposite side, a projection 3c is provided. Reference numeral 8 denotes an annular coil bobbin having a U-shaped cross section, made of a non-magnetic material, supported on the sliding surface 4a of the boss 4, and accommodating the exciting coil 9, for example, a plurality of coils from the end in the opposite direction to the rotor 3. The arm 8a is connected. Among the plurality of arms 8a, at least one arm 8a houses a power supply line for the exciting coil 9 and also serves as a guide for drawing out the power supply line to a power supply terminal (not shown). Reference numeral 8a is provided to increase the strength of support to a rotation preventing mechanism described later. An outer shell 10 is made of a magnetic material and is fixed to the outer periphery of the coil bobbin 8. The outer peripheral surface of the side end of the rotor 3 faces the inner peripheral surface of the protruding portion 3c of the rotor 3 via a gap G2. Pole part 1 protruding from coil bobbin 8 in the opposite direction
0a. The outer peripheral surface of a magnetic pole portion 4b formed at the end of the boss 4 opposite to the rotor 3 faces the inner peripheral surface of the magnetic pole portion 10a of the outer shell 10 via a gap G3.

Numeral 11 denotes a braking magnet, which is shown in FIG.
(A 'cross-sectional view), a permanent magnet 11a having a ring shape and having inner and outer peripheral surfaces magnetized to different polarities S and N, and a ring-shaped magnetic member joined to the inner and outer magnetic poles respectively. It consists of bodies 11b and 11c. The brake magnet 11 has the leg 12b of the pin 12 loosely fitted at, for example, three places of the magnetic body 11b, and the tip of the leg of the pin is fixedly supported by the magnetic pole 4b of the boss 4. In this case, the side surfaces of the ring-shaped magnetic bodies 11b and 11c on the boss 4 side face the respective side surfaces of the magnetic pole portion 4b of the boss 4 and the magnetic pole portion 10a of the outer shell 10, and the head 12a of the pin 12 and the side surface of the magnetic pole portion 4b. It is assumed that it is possible to move in the axial direction of the driven shaft 1 between the positions.

The braking magnet body 11 corresponds to a so-called brake armature of an electromagnetic brake, and can be variously deformed. For example, the ring-shaped permanent magnet 11a is divided into a plurality and arranged at appropriate intervals. The entire braking magnet 11 may be an integral permanent magnet. 4 and 5 show a configuration example of a mechanism for preventing the rotation of the arm 8a of the coil bobbin 8. In FIG. 4, the arm 8a protrudes from the notch 13a formed in the casing 13 and the tip of the arm 8a is It is fixed to a stationary part such as a device driven by. Next, the configuration of the detent mechanism of the coil bobbin will be described with reference to FIGS. The detent mechanism of the coil bobbin shown in FIG. 4 is a detent mechanism of the arm 8a that also serves as a guide for the power supply line of the exciting coil 9, and has a space through which the arm 8a containing the power supply line passes. . On the other hand, the detent mechanism shown in FIG. 5 has no built-in power supply line, and is provided with an arm 8a for maintaining the support strength.
The tip of the arm 8a is engaged with a groove 13b formed in the casing 13 and serves exclusively to prevent the rotation of the coil bobbin 8, and usually engages with a plurality of arms 8a, respectively. Groove 13b.

The casing 13 which is a part of the detent mechanism shown in FIGS. 4 and 5 is, for example, a casing provided with a stand (see FIG. (Not shown). Next, a more specific configuration example of the arm 8a accommodating a power supply line for energizing the excitation coil 9 is as shown in FIGS. In the configuration of FIG. 6, the configuration of the arm 8a shown in FIG.
A power supply line 9a having two built-in conductors is passed through the concave portion 8b formed thereby, and is connected to a power supply terminal (not shown). On the other hand, in the configuration of FIG. 7, a through hole 8c is formed instead of the concave portion 8b formed in the arm 8a of FIG. 6, and the power supply line 9a is accommodated in the through hole 8c.

In the above description of the embodiment, the clutch armature 6 is a relatively small electromagnetic clutch which is supported only by the spring 7 on the clutch armature support 5. Depending on the size of the capacity, it is desirable to use a well-known spline mechanism.

Next, the operation of the electromagnetic clutch having the braking function of the present invention based on the configuration of the above embodiment will be described. First, an armature support 5 from a driving source (not shown)
When the gear 5a formed as described above receives a driving force, the armature support 5 rotates in a direction determined by the driving source. In this state, when the exciting coil 9 is excited, the state shown in FIG. 1 is obtained. That is, the boss 4 → the inner peripheral portion of the rotor 3 → the clutch armature 6 → the protrusion 3c of the rotor 3 → the air gap G2 →
Outer shell 10 → Magnetic pole part 10a of outer shell →
A magnetic flux φ1 is generated in the gap G3 → the magnetic pole portion 4b of the boss 4 → the closed magnetic path of the boss 4, and the clutch armature 6 is attracted to the rotor 3.

At the same time, N and S polarities appear on the magnetic pole portion 10a of the outer shell 10 and the magnetic pole portion 4b of the boss 4, respectively.
a and the magnetic pole part 4b of the boss 4 are opposed to the ring-shaped magnetic bodies 11b and 11c of the braking magnet body 11 having the same polarity, respectively, and the braking magnet body 11 is in the magnetic pole part 10a of the outer shell 10. And a strong magnetic repulsive force is obtained from the magnetic pole portion 4b of the boss 4. Therefore, the braking magnet 11 is
2, the gap G4 is secured, and the magnet body 11 for braking and the outer shell 10 do not come into contact with each other.
The braking magnet 11 does not exert a braking action on the driven shaft 1.

Therefore, the rotation of the armature support 5 based on the external power source is controlled by the spring 7, the clutch armature 6,
The power is transmitted to the driven shaft 1 via the rotor 4. At this time, with the rotation of the boss 4, torque is transmitted on the sliding surface 4a in the direction in which the coil bobbin 8 rotates, but the casing 13 serving as detent means connected by an arm 8a extending from the coil bobbin 8 is connected. Existence (see FIGS. 4 and 5)
Thus, rotation of the coil bobbin 8 can be prevented. Next, when the supply of the exciting current to the exciting coil 9 is stopped while the gear 5a formed on the armature support 5 receives the driving force from a driving source (not shown) and is rotating, the state shown in FIG. 2 is obtained. That is, the magnetic attraction between the rotor 3 and the clutch armature 6 disappears, a gap G1 is formed between the opposing surfaces of the rotor 3 and the clutch armature 6 by the spring pressure of the spring 7, and the armature support 5 is At the sliding surface 2a.

On the other hand, in FIG. 1 when the exciting coil 9 is excited, the polarity N appearing on the magnetic pole portion 10a of the outer shell 10 and the polarity S appearing on the magnetic pole portion 4b of the boss 4 disappear. Therefore, as shown in FIG. 2, the permanent magnet 11a of the braking magnet 11 → the ring-shaped magnetic body 11c → the magnetic pole 10a of the outer shell 10 → the air gap G3 → the magnetic pole 4b of the boss 4.
→ A ring-shaped magnetic body 11b of the braking magnet body 11 → A closed magnetic circuit of the permanent magnet 11a is formed, a magnetic flux φ2 is generated, and the polarity of the magnetic pole part 10a of the outer shell 10 and the magnetic pole part 4b of the boss 4 is S. , N pole, and integrated by magnetic attraction. As a result, the driven shaft 1 that is about to rotate due to the inertial force receives a strong braking action and stops almost instantaneously.

In the braking mode shown in FIG. 2, the outer shell 10 as a stationary member and the coil bobbin 8
Receives a reaction force due to stronger braking as compared with the swirling action of FIG. 1, but the outer shell 10 and other stationary members are kept stationary by the anti-swirling means of the arm 8a (see FIGS. 4 and 5). .

[0021]

As is apparent from the above description, the electromagnetic clutch having a braking function according to the present invention has the following excellent effects. First, let's talk about the basic characteristics.
The main purpose is to shorten the time from the clutch OFF of the driven shaft to the standstill due to inertia, and it is suitable for the application device of the electromagnetic clutch especially when good responsiveness is required and the size of the electromagnetic clutch is limited. There is a point. In other words, conventionally, electromagnetic clutch ON, OF
In order to improve the responsiveness of the F, it was essential to add a brake function. However, in order to realize this, an independent coil or permanent magnet was incorporated inside the brake device, so the entire clutch became larger. There were some points that could not be put to practical use depending on the application device, but the point of solving these points is the feature of the present invention. Next, the effects of the present invention will be described for each invention described in each claim.

(1) According to the first aspect of the present invention, as a conventional brake armature equivalent member, a brake magnet body having a permanent magnet is used, and the brake occupies substantially the same size as the clutch excitation mechanism. By eliminating the magnetic flux generating mechanism for use, and eliminating the need for a leaf spring for release control of the brake armature due to the interaction with the magnetic pole obtained by exciting the coil, a small electromagnetic clutch can be obtained with good responsiveness.

(2) According to the second aspect of the present invention, the coil bobbin in the clutch ON state can be reliably prevented from rotating together with the coil bobbin and the outer shell against the strong braking force generated when the clutch is off. Rotation of other peripheral stationary members can also be properly prevented.

(3) According to the third aspect of the invention, one of the arms for preventing the coil bobbin from rotating can be used also as the guide member for the power supply line to the coil, so that the power supply mechanism of the electromagnetic clutch is simplified. Can be.

(4) According to the fourth aspect of the present invention, a uniform magnetic flux can be generated from the entire braking magnet body, the braking action can be stabilized, and the magnetization of the braking magnet body can be improved. Assembling becomes easy.

(5) According to the fifth aspect of the invention, the braking magnet can easily respond to the magnetic attraction force or the magnetic repulsion force, and the responsiveness of ON or OFF of the electromagnetic clutch can be improved. .

[Brief description of the drawings]

FIG. 1 is a half vertical sectional side view showing a configuration of an electromagnetic clutch having a braking function according to an embodiment of the present invention, showing a state during power transmission.

FIG. 2 is a half vertical sectional side view showing a state when power transmission of the electromagnetic clutch shown in FIG. 1 is cut off.

FIG. 3 is a sectional view taken along line AA ′ of FIG. 1;

FIG. 4 is a perspective view showing an example of a detent fixing means in the case of an arm accommodating a power supply line used for an electromagnetic clutch having a braking function according to the present invention.

FIG. 5 is a main part front view showing an example of a detent fixing means in the case of an arm for supporting strength without accommodating a power supply line used for an electromagnetic clutch having a braking function according to the present invention.

FIG. 6 is a perspective view showing an example of a specific configuration of an arm for accommodating a power supply line used in an electromagnetic clutch having a braking function according to the present invention.

FIG. 7 is a perspective view showing another configuration example of a power supply line storage arm used for an electromagnetic clutch having a braking function according to the present invention.

[Explanation of symbols]

 1: Driven shaft 2: Sleeve 3: Rotor 4: Boss 4a: Magnetic pole part of boss 5: Clutch armature support 6: Clutch armature 7: Spring 8: Coil bobbin 8a: Coil bobbin arm 9: Coil 9a: Power supply line to coil 10: Outer shell 10a: Magnetic pole portion of outer shell 11: Magnet for braking 12: Pin 13: Casing (rotation support for coil bobbin)

Claims (5)

[Claims] 1. A sleeve, a rotor, a boss, a driven shaft in which the sleeve, the rotor, and the boss are sequentially fixed integrally, rotatably supported by the sleeve, and provided to be rotated by external power. A clutch armature supported by the clutch armature support via a spring disposed between the clutch armature support and the rotor and operating in a direction displacing the clutch armature support toward the clutch armature support; Detent means for fixing and supporting the boss, an outer shell provided with a protrusion on the anti-clutch armature side of the coil bobbin, and an outer shell disposed on the inner peripheral edge of the protrusion to face the protrusion of the boss via a gap, and containing the exciting coil therein The outer peripheral side is fixed to the outer shell and the boss is rotatable. An annular coil bobbin made of a non-magnetic material to be supported; and a braking magnet body having a surface facing each outer surface of the outer shell projecting portion and the boss projecting portion, wherein each facing surface of the braking magnet body is provided. Is excited by the exciting coil,
A magnet for braking, which has the same polarity as that of the protrusion of the outer shell and the protrusion of the boss, and is supported by the boss so as to be movable in the axial direction of the driven shaft. An electromagnetic clutch having a braking function, comprising: 2. The braking function according to claim 1, wherein the detent means for the coil bobbin is constituted by a plurality of arms extending outward from the coil bobbin, and a stationary member engaged with these arms to prevent detent. Electromagnetic clutch. 3. An electromagnetic clutch having a braking function according to claim 2, wherein one of said arms houses a power supply line for an exciting coil housed in a coil bobbin. 4. The braking magnet body is formed by joining a permanent magnet having a rectangular section in cross section, magnetized to different polarities on inner and outer peripheral surfaces, and an annular body made of a magnetic material on each magnetic pole surface of the permanent magnet. An electromagnetic clutch having a braking function according to any one of claims 1 to 3, wherein the electromagnetic clutch is configured as follows. 5. A means for moving the braking magnet body relative to the boss in the axial direction of the driven shaft, comprising: a head and legs at at least three locations located at substantially equal intervals on an inner peripheral edge. 5. The leg of the pin is loosely fitted, the tip of the leg is fixed to the boss, and the pin is movably supported between the head of the pin and the boss. An electromagnetic clutch having the braking function according to any one of the above.