JPS6311858B2 - - Google Patents

Description

DETAILED DESCRIPTION OF THE INVENTION The present invention relates to a clutch motor having an electromagnetically operated power transmission mechanism.

In a conventional electromagnetic clutch motor, as shown in Fig. 1, a clutch electromagnet 1, a brake electromagnet 2, and a brake ring 3 are each fixed to a bracket 4, and the clutch ring is attached to a flywheel 5 that is driven at a constant speed by a motor. 6 is fixed. Further, the output shaft 7 is provided with a clutch rotary plate 9 and a brake rotary plate 10 which are splined so as to be prevented from rotating in the rotational direction but slidable in the axial direction. Material 8 is attached. In addition, 8' is a friction material attached to the brake rotating plate 10, 11 is a motor shaft, 12 is a main bearing, and 13 is a gap adjustment screw.

Here, when the clutch electromagnet 1 is energized, the magnetic flux passes through the magnetic path 101, and the electromagnetic force causes the clutch rotary plate 9 to come into pressure contact with the clutch ring 6, and rotational force is transmitted to the output shaft 7. Note that the output shaft 7 rotates at an arbitrary speed by controlling the current flowing through the clutch electromagnet 1 using a speed control device provided separately (not shown), and when the brake electromagnet 2 is energized, the magnetic flux is transferred to the magnetic path 102. The electromagnetic force presses the brake rotary plate 10 against the brake ring 3, causing the output shaft 7 to rapidly decelerate and stop.

This type of electromagnetic clutch motor is often used as a drive source for industrial sewing machines, and is required to accelerate and decelerate the output shaft 7 extremely quickly in order to increase its working efficiency. In addition, in industrial sewing machines,
It is common to have the function of stopping the needle at a fixed position, but in order to accurately determine the stopping position accuracy,
It is required that the sliding angle from when a stop signal is given to when the vehicle stops is as small as possible. In order to satisfy these requirements, it is necessary that the inertia of the output shaft 7 be as small as possible. The conventional electromagnetic clutch motor described above has a clutch rotating plate 9
Since the brake rotating plate 10 is made of a magnetic material, the inertia of the output shaft 7 is relatively large, making it difficult to fully satisfy the above-mentioned characteristics.
Therefore, in order to reduce the inertia of the movable part directly connected to the output shaft 7, it is essential that this part be separated from the magnetic circuit and made of a material with low specific gravity.

The present invention solves the above-mentioned conventional drawbacks,
The present invention will be explained below with reference to FIG. 2 showing one embodiment thereof.

In Fig. 2, 21 is a motor frame, 22 is a clutch bracket, 23 is a motor shaft, 24 is an output shaft, 25, 26, 27 are ball bearings, 28 is a flywheel, 29 is a fixed iron core for the clutch, and 30 is a A fixed iron core for the brake, 31 is a clutch coil, 32 is a brake coil, 33 and 34 are a clutch ring and a brake ring both made of magnetic material, 35 and 36 are pins, and screws 37 and 3
8 respectively flywheel 28 and bracket 2
It is fixed at 2. 39 and 40 are sliding members made of sintered metal or oil-impregnated plastic, and are supported by the clutch ring 33 and brake ring 34 by rubber bushes 41 and 42, respectively. The pins 35, 36 and the sliding material 3
9 and 40, it is possible to slide in the axial direction with a clearance of several tens of microns. Coil springs 43 and 44 lightly press the clutch ring 33 and brake ring 34 toward a clutch rotor 45, which will be described later. These pin blocks are arranged circumferentially on both the clutch and brake sides.
Three sets each are arranged at 120° intervals. Reference numeral 45 designates a clutch rotor made of resin, and friction materials 46 and 47 made of cork or the like are adhered to both sides of the clutch rotor. This clutch rotor 45 has washers 49
It is fixed to the output shaft 24 with a screw 48.

FIG. 3 shows a center sectional view of the clutch rotor 45. In the figure, reference numeral 51 indicates ribs arranged radially at four locations, which serve as reinforcement. Reference numeral 52 is a keyway, which serves to prevent the output shaft 34 from slipping.

Now, when a power switch (not shown) is turned on, the main motor rotates, and the flywheel 28 directly connected to it rotates continuously. Therefore, the clutch ring 33, which is fixedly supported by the flywheel 28 with the pin 35 in the rotational direction, also rotates continuously. Here, when the clutch coil 31 is energized, the fixed iron core 29 for the clutch becomes an electromagnet, and the clutch ring 33 is attracted by the electromagnetic force and is pressed against the friction material 46, and the rotational torque of the main motor is outputted via the clutch rotor 45. It will be transmitted to the shaft 24.

Similarly, the brake ring 34 is fixedly supported by the clutch bracket 22 in the rotational direction by the pin 36, so that the brake coil 3
When the brake ring 34 is energized to the friction material 4
7, the output shaft 24 suddenly decelerates and stops.

It actually has a speed detector (not shown), a speed setting device, and a speed control circuit, and the clutch coil 31 and the brake coil 32 have a pulse-like structure that responds to the difference between the set speed and the detected speed. Variable speed movement is possible by supplying current alternately.

Here, the rubber bushes 41 and 42 serve as a cushioning material, absorbing abnormal sounds at the pin part,
Alternatively, it has the effect of absorbing dimensional deviations due to thermal expansion of the clutch/brake rings 33, 34 due to frictional heat. The coil spring 43 uses a weaker spring than the coil spring 44. Therefore, when both the clutch coil 31 and the brake coil 32 are not energized, the pressing force of the clutch ring 33 against the clutch rotor 45 is weaker than the pressing force of the brake ring 34, and the output shaft 24 will not idle.

Here, aluminum was considered as the material for the clutch rotor 45, and after making a prototype using aluminum die-casting and conducting various studies, it became clear that it was not necessarily the optimal material. First, although it is better than conventional magnetic materials, its specific gravity is approximately 2.7, and its inertia is not as low as expected. The second problem is that noise is generated. In other words, the clutch/brake ring 33, 3
At the moment when the clutch rotor 45 is attracted and torque is transmitted, the clutch rotor 45 makes a metallic sound, and it is generally quite difficult to eliminate this abnormal sound.

In order to improve these problems when using aluminum, we considered using resin molded products, and as a result of repeated prototype experiments, we decided to use so-called FRP (glass fiber reinforced plastics) as the material for the clutch rotor 45. was found to be optimal. In particular, so-called BMC reinforced with glass fibers based on unsaturated polyester resin.
It was concluded that SMC can be used as such a structural material due to its high specific strength, good dimensional accuracy, high heat resistance, and low thermal deformation. The specific gravity is around 1.7, about 60% of aluminum, and the inertia is reduced accordingly.
Results Compared to the conventional example shown in Figure 1, the inertia of the output shaft is
This has been reduced to 30%, making it possible to create an electromagnetic clutch motor with extremely good acceleration/deceleration characteristics. Also, there is no noise like when using aluminum.
At the same time, it also contributed to price reduction.

Furthermore, the structure of this clutch rotor 45 is
As shown in the figure, it is advantageous to provide a plurality of ribs 51 so as to bridge both sides to which the friction material is attached. That is, the purpose is to reduce the cost and inertia by reducing the amount of material used as much as possible, and at the same time, the rib portion 51 ensures mechanical strength. At the same time, since it has a waterwheel-like shape, it can also serve as a fan and serve the purpose of blowing air to cool various parts.

As is clear from the above description, the present invention provides an electromagnetic clutch motor that has a low output shaft inertia and good acceleration/deceleration characteristics, does not generate abnormal noise when the clutch/brake is turned on, and is well cooled. , and its industrial effects are tremendous.

[Brief explanation of the drawing]

Fig. 1 is a sectional view of the main parts of a conventional electromagnetic clutch motor, Fig. 2 is a sectional view of the main parts of an electromagnetic clutch motor showing an embodiment of the present invention, and Fig. 3 is a sectional view of the clutch rotor. . 22...Clutch bracket, 24...Output shaft, 28...Flywheel, 29...Fixed iron core for clutch, 30...Fixed iron core for brake, 31...
...Clutch coil, 32...Brake coil, 3
3... Clutch ring, 34... Brake ring, 45... Clutch rotor, 46, 47... Friction material, 51... Rib.

Claims (1)

[Claims] 1. A clutch ring is attached to a continuously rotating flywheel so as to be fixed in the direction of rotation and movable in the axial direction, and a clutch ring is attached to the flywheel that is fixed in the direction of rotation and movable in the axial direction. A brake ring is movably attached to the clutch ring and a brake ring, and a clutch electromagnet and a brake electromagnet are arranged to face the clutch ring and the brake, respectively, and between the clutch and the brake ring, a brake ring is fixed to the output shaft and is attached to both sides. 1. An electromagnetic clutch motor, characterized in that a clutch rotor having a friction material is disposed at the clutch rotor, and the clutch rotor is made of a resin molded product. 2 The clutch rotor made of the resin molded product is
2. The electromagnetic clutch motor according to claim 1, wherein the electromagnetic clutch motor is made of glass fiber reinforced plastic. 3. The electromagnetic clutch motor according to claim 1 or 2, wherein the clutch rotor has a plurality of ribs arranged radially.