JPH08145096A - Electromagnetic clutch with brake - Google Patents

Abstract

PURPOSE: To provide an electromagnetic clutch with a brake which prevents the dropping of worn powder from a brake friction face into a bearing sliding part, and includes a coil spring in the inside for miniaturizing the clutch, and is manufactured at a low cost, and moreover is suitable for paper feeding or the like. CONSTITUTION: A tubular ring 33 having a lining 33b fixed to an inner periphery is coveredly arranged on the outside of the rotor 22 of a clutch. An elastic means 34 is included inside the ring 33, and at the time of the clutch being off braking force is given to the rotor 22 by the elastic means 34, and at the time of the clutch being on, a shell 23 being a pole body draws the ring 33 to release the brake for making the clutch carry out the ordinary function. In addition, a slit 33a is provided at one end of the ring 33 as a connecting part on one side, and a projection 23a is provided at a position corresponding to the slit 33a on a coil bobbin 35 as a connecting part on the other side.

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to an improvement of an electromagnetic clutch with a brake used for paper feeding of a copying machine or a printer.

[0002]

2. Description of the Related Art An electromagnetic clutch with a brake, which is suitable for paper feeding and the like, has a simplified structure by incorporating a braking function in the magnetic circuit of the clutch without using a brake hub, and can be reduced in size. It has been filed as Japanese Patent No. 6-103291. The configuration of the conventional electromagnetic clutch with brake will be outlined with reference to FIG. FIG. 4 (A) is a vertical sectional front view of the electromagnetic clutch with a brake, FIG. 4 (B) is a side view of the brake armature included in FIG. 4 (A),
FIG. 4C is a perspective view of the coil bobbin included in FIG. As shown in FIG. 4, the clutch rotor 2
The brake armature 13 is arranged between the opposite side of the clutch friction surface 2a and the magnetic pole body 3, and when the clutch is OFF, the braking force is applied to the rotor 2 by the elastic means 14, and when the clutch is ON, the brake armature 13 is magnetic pole. The body 3 is sucked to release the brake, and the normal clutch function is performed. Elastic means 14
Are supported by the bracket 6. In this case, the brake armature 13 is provided with a plurality of one linking portions 13a to 13c (FIG. 4B) provided circumferentially on the surface of the magnetic pole body 3 side. One of the coil bobbins 15 provided for housing the coil with respect to the magnetic pole body 3 has a plurality of other linking portions provided on the end surface on the brake armature 13 side at positions corresponding to the one linking portions 13a to 13c. 15a to 15c (Fig. 4
(C)), the brake armature 13 is attached to the fixed portion via the elastic means 14,
When the clutch is off, the braking force can be applied not only by the elastic means 14 but also by the interlocking of the respective link portions 13a to 13c and 15a to 15c. The brake armature 13 may be constructed so as to straddle the outer peripheral portion of the rotor. The reason why the electromagnetic clutch used for paper feeding of a copying machine or printer is provided with a brake function is as follows. That is, this kind of electromagnetic clutch is attached to a paper feed roller and the clutch is turned on to feed the paper when necessary, but recently, the quality of the paper used has been diversified, especially If thick, the clutch is off
This is to prevent a paper feeding error in which the paper is fed by the bending pressure even though the paper is in the state of being in the state of being in a state of being fed.

[0003]

By the way, since the above-mentioned electromagnetic clutch with a brake is constructed as described above, it has the following problems. Abrasion powder falls from the brake friction surface of the brake armature 13 onto the sliding portions of the bearings 18 and 19 to hinder the sliding operation. The flange portion that holds the coil spring 14 of the elastic means becomes an obstacle to downsizing. Since the coil spring 14 is exposed to the outside, malfunction may occur due to interference from the outside.

[0004]

SUMMARY OF THE INVENTION In order to solve the above problems, according to the present invention, a ring-shaped lining having a quadrangular cross-section having an end portion facing a shell, which is a magnetic pole body, is provided on the outer periphery of a rotor of a clutch. A tubular ring fixed to the middle of the coil bobbin is disposed, and one or a plurality of link portions is provided at the shell-side end of the ring, and the coil bobbin is provided in the shell for coil storage. Is provided with one or a plurality of other linking parts corresponding to one linking part of the ring, and the ring is slidable in the axial direction by being guided by the linking part of the coil bobbin and the outer peripheral part of the rotor. Elastic means is mounted inside the ring between the lining and the inner wall of the coil bobbin,
When the clutch is off, the lining applies a braking force to the rotor, which forms a brake friction surface with the end of the rotor, and also applies a braking force by the cooperation of the respective linking parts. Therefore, it is intended to provide an electromagnetic clutch with a brake, in which a ring, which is a brake armature, is attracted to a shell to release the brake when the clutch is turned on. The one linking portion may be a protrusion and the other linking portion may be a slit, or vice versa.

[0005]

In the electromagnetic clutch with a brake according to the present invention, as described above, the lining is fixed to the longitudinal center of the inner circumference of the ring which is the brake armature, and the abrasion powder from the brake friction surface falls on the coil. Since the sliding part of the bearing is not damaged and the coil spring, which is the elastic means, is contained in the ring, the flange part for holding the coil spring is unnecessary, and there is no interference from the outside. To be removed.

[0006]

DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENT An embodiment of an electromagnetic clutch with a brake according to the present invention will be described below with reference to FIGS. FIG. 1 is a vertical sectional front view of an embodiment of an electromagnetic clutch with a brake, FIG. 2 is a side view taken along arrow A in FIG. 1, FIG. 3 (A) is a side view of a ring included in FIG. 1, and FIG. 3 (A) is an enlarged cross-sectional view taken along line BB of FIG. 1 to 3, the same components as those in FIG. 4 are designated by the same reference numerals as those in FIG. Reference numeral 1 denotes a clutch armature, which is fixed to a drive shaft 12 with screws 12a and 12b through a support 1a thereof. Reference numeral 22 is a rotor of the clutch, 23 is a shell which is a magnetic pole body having a coil 23a, 38 and 39 are bearings, 25 is a driven shaft, and 23b is a brake arm, which is connected to a fixed portion (not shown). There is. Reference numeral 33 is a ring that is a brake armature, and one or a plurality of slits 33a (one in the example of FIGS. 1 to 3) serving as one linking portion is provided at one end of the tubular main body, and A ring-shaped lining 33b having a quadrangular cross section is attached in the middle in the longitudinal direction by driving or gluing. This ring 33
The slit 33a is linked to the projection 35a (see FIG. 1 and FIG. 2) which is the other linking part corresponding to the one linking part of the coil bobbin 35 provided for housing the coil in the shell, and the lining 33b. Brake friction surface 33 '
The outer peripheral portion of the rotor 22 is guided to the outside of the rotor 22 so that b faces the brake friction surface 22b of the rotor 22 and is slidable in the axial direction. The elastic means (coil spring) 34 is housed inside the ring 33, one end of which is in contact with the inner wall 35b of the coil bobbin 35, and the other end of which is mounted so as to push the lining 33b.

In the above structure, when the clutch is off, the braking force is applied to the rotor 22 which forms the brake friction surface with the end portion of the rotor 22, and the braking force is also exerted by the linkage between the linking portions. When the clutch is turned on, the ring 33, which is the brake armature, is attracted to the shell 23 to release the brake, and the normal clutch function is performed. That is, when the coil 23a is energized, as shown in FIG. 1, the clutch armature 1, the rotor 22, the ring 33 as a brake armature, the shell 23 as a magnetic pole body, and the magnetic flux Φ as shown by a broken line on the driven shaft 25 are generated. A magnetic path is formed, and the clutch armature 1 is connected to the rotor 22.
Therefore, the torque of the drive shaft 12 is transmitted to the driven shaft 25 via the clutch armature 1 and the rotor 22, and performs the required driving such as paper feeding to an applicable machine (not shown) via the driven shaft 25. In this case, since the ring 33 is attracted to the shell 23 against the spring pressure of the elastic means (coil spring) 34, the braking action on the driven shaft 25 is released. Next, when the coil 23a is de-energized, the clutch armature 1 is released from the attraction to the rotor 22, so that the rotor 22, and hence the driven shaft 25 loses the driving force, and the lining 33b of the ring 33 is further elastic. Since the rotor 22 is pressed against the rotor 22 by the spring pressure of the (coil spring) 34, the protrusions 35a of the coil bobbin 35 are slipped on the rotor 22 at the brake friction surface 22b and the brake friction surface 33'b of the lining 33b. Since it is fitted in the slit 33a of the ring 33 and is connected to the ring 33 via the elastic means 34, a required braking force is applied to the driven shaft 25. Therefore, even if thick paper is used on the application machine side, it is possible to prevent a paper feed error. Further, in the above-described embodiment, the ring 33 is provided with the slit serving as one linking portion and the coil bobbin 25 is provided with the protrusion serving as the other linking portion, thereby linking the two. The part may be a protrusion and the other linking part may be a slit.

[0008]

Since the electromagnetic clutch with brake according to the present invention is constructed as described above, it has the following excellent effects. Since the brake friction surface of the lining of the ring, which is the brake armature, is located outside the coil, abrasion powder does not fall on the sliding surface of the bearing, and sliding is performed smoothly. Since the brake friction surface of the ring lining is outside the friction surface of the clutch armature and the friction radius is large, a large brake torque can be obtained. Therefore, a weak spring force is enough to obtain the same torque as the clutch.
The coil springs need only be small and small, and in combination with the fact that the flange portion for holding the coil springs is unnecessary, the size can be reduced. Since the coil spring is contained and is not exposed, malfunction does not occur due to external interference.

[Brief description of drawings]

FIG. 1 is a vertical sectional front view of an embodiment of an electromagnetic clutch with a brake according to the present invention.

FIG. 2 is a side view taken along arrow A in FIG.

FIG. 3A is a side view of the ring included in FIG. 1,
(B) is an enlarged cross-sectional view taken along the line BB of (A).

4A is a vertical sectional front view of a conventional electromagnetic clutch with a brake, FIG. 4B is a side view of a brake armature included in FIG. 4A, and FIG. 4C is a perspective view of a coil bobbin included in FIG. is there.

[Explanation of symbols]

 1: Clutch armature 22: Rotor 22b: Brake friction surface 23: Shell 33: Ring 33a: Slit 33b: Lining 33'b: Brake friction surface 34: Elastic means (coil spring) 35: Coil bobbin 35a: Protrusion 35b: Inner wall

Claims (3)

[Claims] 1. A ring-shaped lining having a square cross-section having a quadrangular cross section, one end of which faces a shell, which is a magnetic pole body, is fixed to the outside of the rotor of the clutch, and a tubular ring is fixed to the middle of the inner circumference in the longitudinal direction. Is provided with one or a plurality of link portions at the end portion on the shell side, and one or a plurality of link portions corresponding to one link portion of the ring is provided in a coil bobbin provided for coil storage in the shell. And the ring is guided by the linking portion of the coil bobbin and the outer peripheral portion of the rotor so as to be slidable in the axial direction, and the lining and the inner wall of the coil bobbin are provided inside the ring. Elastic means is mounted between the rotor and the rotor, and when the clutch is off, the lining applies a braking force to the rotor that forms a brake friction surface with the end of the rotor, Also, the braking force is applied by the mutual connection of the respective linking parts, and when the clutch is ON, the ring which is the brake armature is attracted to the shell to release the brake. Electromagnetic clutch with brake. 2. The one linkage portion is a slit, the other linkage portion is a protrusion, or conversely, the one linkage portion is a protrusion,
The electromagnetic clutch with a brake according to claim 1, wherein the other linking portion is a slit. 3. The electromagnetic clutch with a brake according to claim 1, wherein the elastic means is a coil spring.