JPH051695Y2 - - Google Patents

Description

[Detailed explanation of the idea] Industrial applications This invention relates to a spring clutch.

Prior Art First, conventional examples are shown in FIGS. 4 to 7. 1
is a motor, and pulley 2 is directly connected to motor 1.
A timing belt 5 is wound around a pulley 4 fixed to a drive shaft 3. A driven wheel body 7 is loosely fitted onto a shaft 6 that is loosely fitted to the drive shaft 3, and driven wheels 8 and 9 located at both ends are coupled so as to rotate integrally. Coil springs 11 and 12 are wound around the drive shaft 3 and the bosses 10 of the driven wheels 7 and 8. Hooks 13 are formed at one ends of these coil springs 11 and 12, and clutch cams 14 and 15 for holding these hooks 13 are provided. Furthermore, protrusions 16 are formed on part of the side surfaces of the driven wheels 7 and 8. Further, on the outer peripheries of the clutch cams 14 and 15, a protrusion (not shown) that abuts the protrusion 16 and a locking pawl 1 are provided.
7 is formed.

Next, two electromagnets 18 are provided on the outer peripheries of the clutch cams 14 and 15, facing each other. The armatures 19 of these electromagnets 18 are biased by springs 20 in the direction in which their tips engage the locking claws 17, and a stopper 2 that limits the operating range of the armatures 19 is attached to a mounting plate 21 that holds the coil 18a of the electromagnets 18.
2 is retained. The armature 19 is rotatably held by engaging protrusions 27 formed on the mounting plate 21 with notches 24 formed on both side edges thereof.

Therefore, the rotation of the motor 1 is transmitted to the drive shaft 3, but when the rotational movement of the clutch cams 14, 15 is prevented by the engagement between the locking pawl 17 and the armature 19, the driven wheels 7, 8, 9 does not rotate.
As shown in FIG. 6, when the armature 19 is separated from the locking claw 17 by the excitation action of the electromagnet 18, the coil springs 11 and 12 rotate together with the clutch cams 14 and 15 due to the frictional force with the drive shaft 3, and the clutch cam 14 , 15 protrusions and protrusions 16
The driven wheels 7 and 8 rotate due to contact with the driven wheels 7 and 8. The rotation of the driven wheel body 8 is transmitted to the driven wheel body 9 via the shaft 6. The energization of the electromagnet 18 is instantaneous, and by the time the clutch cams 14 and 15 make one revolution, the armature 19 is activated by the force of the spring 20.
The armature 19 comes into contact with the locking pawl 17 when the clutch cams 14 and 15 rotate once. Therefore, the clutch cams 14, 15 and the driven wheels 7, 8, 9 rotate once and then stop.

Problems to be Solved by the Invention However, in order to rotate the armature 19 smoothly, it is necessary to make the vertical width b of the notch 24 larger than the plate thickness t of the protruding piece 27. As a result, when the clutch cams 14, 15 rotate once, the locking pawl 17 pulls the restored armature 19 upward, and the collision between the lower edge of the protrusion 27 and the lower edge of the notch 24 is loud and unpleasant. It is.

This invention was made in view of these points, and the purpose is to provide a spring clutch that can suppress noise.

Means for Solving the Problem A drive shaft and a driven wheel body are disposed on the same axis, and one end of a coil spring wound around the outer periphery of the drive shaft is held to control the rotation of the drive shaft. A spring clutch is provided with a clutch cam that transmits transmission to the driven wheel body via a coil spring, and selectively rotates the clutch cam by engaging and disengaging an armature of an electromagnet with a locking pawl formed on the outer peripheral surface of the clutch cam. , a protruding piece and a notch that engages with the protruding piece are formed in opposing portions of the mounting plate that holds the coil of the electromagnet and both side edges of the armature, so that the armature is protected from the contact force from the locking pawl. A biasing body is provided that biases in the acting direction to bring one edge of the projecting piece into contact with one edge of the notch.

Function: Therefore, the action of the electromagnet releases the engagement between the locking pawl and the armature, rotates the clutch cam, returns the armature, and stops the clutch cam. By maintaining one edge of the protruding piece and the notch formed in the armature in contact with each other, collision noise between the armature and the mounting plate is prevented from occurring when the armature is engaged with the locking pawl.

Embodiment An embodiment of this invention will be explained based on FIGS. 1 to 3. Components that are the same as those described in FIGS. 4 to 6 are designated by the same reference numerals, and description thereof will be omitted. Clutch cam 1 from the top of locking claw 17
An arcuate protrusion 23 whose protrusion radius gradually decreases toward the rear in the rotational direction of the clutch cams 14 and 15 is integrally formed on the outer peripheral surface of the clutch cams 14 and 15. The height of the protrusion in the radial direction of the bulging protrusion 23 is at its maximum in a range of approximately 90° in the circumferential direction of the clutch cams 14 and 15 from the top of the locking pawl 17, and changes continuously thereafter until it reaches the top of the locking pawl 17. It reaches its minimum at a position approximately 270° away from the center. The rotation direction of the clutch cams 14, 15 is counterclockwise in FIGS. 1 and 2. Therefore, the direction toward the rear in the rotational direction of the clutch cams 14 and 15 is a clockwise direction with respect to the locking pawl 17.

Next, as shown in Figure 3, amateur 19
A notch 24, a locking hole 25, and a spring 20 are provided on both sides of the
A small hole 26 is formed to hold one end of the electromagnet 18, and a protrusion 27 that engages with the notch 24 is formed on the mounting plate 21 that holds the coil 18a of the electromagnet 18 and the stopper 22. The relationship between the vertical width b of the notch 24 and the plate thickness t of the protruding piece 27 is the same as that shown in FIG. The plate spring 28 is a biasing body whose tip engages with the locking hole 25 and biases the armature 19 in the rotational direction (upward) of the clutch cams 14 and 15.
is fixed to the mounting plate 21 with screws 29.

In such a configuration, the electromagnet 18 is energized in the state shown in FIG. 1, and the armature 19 is moved as shown in FIG.
By rotating the coil springs 11 and 1 toward the stopper 22, the frictional force with the drive shaft 3 causes the coil springs 11, 1 to
2 rotates counterclockwise together with the clutch cams 14 and 15. In this state, as shown in FIG. 2, the distance between the armature 19 and the bulging protrusion 23 is extremely small. Therefore, even if the power supply to the electromagnet 18 is cut off and the armature 19 is returned to its original state, the armature 19 moves slightly and is immediately supported by the bulging protrusion 23.
Just before the end of one rotation of the clutch cams 14 and 15, the clutch cams 14 and 15 return to the position where they engage with the locking pawl 17. Therefore,
The collision sound of the armature 19 against the clutch cams 14, 15 is extremely small.

Further, the armature 19 is urged in the rotational direction of the clutch cams 14 and 15 by the plate spring 28, and the lower edge of the notch 24 and the lower edge of the protruding piece 27 are always in contact with each other, so that there is no play between the notch 24 and the protruding piece 27. Because there is no locking pawl 17 moving counterclockwise,
Even if the armature 19 is pulled by the locking claw 17, no collision noise is generated between the armature 19 and the mounting plate 21.

Note that protrusions projecting outward may be formed on both side edges of the armature 19, and notches that engage with these protrusions may be formed in the mounting plate 21.

Effects of the invention Since this invention is configured as described above, the clutch cam is rotated by releasing the engagement between the locking pawl and the armature by the operation of the electromagnet, but the armature is returned toward the outer peripheral surface of the clutch cam and the clutch cam is rotated. When stopping the armature, one edge of the notch that forms the fulcrum of the armature and the protruding piece is kept in contact with each other to prevent collision between the armature and the mounting plate even if the armature is pulled by the locking pawl. This has the effect of preventing the generation of sound.

[Brief explanation of drawings]

Figures 1 to 3 show an embodiment of this invention, with Figure 1 being a vertical sectional side view showing the stationary state;
Fig. 2 is a longitudinal side view showing the rotation transmission state, Fig. 3 is an exploded perspective view of the electromagnet, Figs. 4 to 7 show conventional examples, and Fig. 4 is a longitudinal side view showing the stationary state. FIG. 5 is a longitudinal side view showing the rotation transmission state, FIG. 6 is a longitudinal front view, and FIG. 7 is an exploded perspective view of the electromagnet. 3... Drive shaft, 7-9... Driven wheel body, 11,1
2... Coil spring, 14, 15... Clutch cam, 17... Locking claw, 18... Electromagnet, 19
... Amateur, 21 ... Mounting plate, 24 ... Notch, 27 ... Projection piece, 28 ... Plate spring (biasing body).

Claims (1)

[Scope of utility model registration request] A drive shaft and a driven wheel body are disposed on the same axis, and one end of a coil spring wound around the outer periphery of the drive shaft is held, and the rotation of the drive shaft is directed to the driven wheel via the coil spring. A spring clutch is provided with a clutch cam for transmitting power to the body, and the clutch cam is selectively rotated by engaging and disengaging the armature of the electromagnet with a locking pawl formed on the outer peripheral surface of the clutch cam, which holds the coil of the electromagnet. A protruding piece and a notch that engages with the protruding piece are formed in the facing portions of the mounting plate and both side edges of the armature, and a protruding piece and a notch that engage with the protruding piece are formed in a direction away from the electromagnet around the engaging part between the protruding piece and the notch. A biasing body that is provided with a spring that biases the armature, and urges the armature in a direction in which a contact force from the locking claw is applied to bring one edge of the projecting piece into contact with one edge of the notch. A spring clutch characterized by being provided with.