JPH0511632Y2 - - Google Patents

Description

[Detailed Description of the Invention] [Industrial Technical Field] The present invention relates to an electromagnetic switch comprising a combination of an electromagnetic contactor, a thermal relay, a push button switch, etc.

[Conventional technology]

FIG. 3 is a circuit diagram showing an example of the use of an electromagnetic switch described on page 42 of "Sequence Control Guidebook for Industrial Engineers" published by Denkishoin Co., Ltd. on May 25, 1978. In the figure, 1 is a power supply,
2 is a knife switch, 3 is an electromagnetic contactor, and 4 is an electric motor. 5 is a normally closed pushbutton switch, 7 is a normally open pushbutton switch, 7 is a self-holding contact, 3a
is the coil of the electromagnetic contactor 3, and 8 is a thermal relay.

In the above circuit, knife switch 2
When the contactor 3 is turned on and the push button switch 6 is closed, the coil 3a of the electromagnetic contactor 3 is energized, the self-holding contact 7 is closed, and a self-holding circuit is formed. As a result, even if the push button switch 6 is released, the operation continues and the electric motor 4 continues to rotate. When the pushbutton switch 5 is pressed, the circuit is opened, the self-holding contact 7 is opened, and the motor 4 is stopped. Further, when the electric motor 4 becomes overloaded, the thermal relay 8 is activated to open a circuit and stop the electric motor 4. Note that when the thermal relay 8 is activated and the electric motor 4 is stopped, the reset button is pressed to reset the thermal relay 8.

FIG. 4 is a plan view of the electromagnetic switch as described above, and FIG. 5 is a longitudinal sectional view thereof. In the figure, 11 is a case, and 12 is a cover. The case 11 houses the electromagnetic contactor 3, the thermal relay 8, etc., and the cover 12 houses the push button 5a of the push button switch 5.
(displayed as OFF), pushbutton switch 6
A button case 13 is attached to which a push button 6a (indicated as ON) and a reset button 8a (indicated as R) of a thermal relay 8 are attached. Note that 9 is a reset lever of the thermal relay 8, with which the tip of the reset button 8a is in contact.

The above-mentioned reset button 8a is normally located at the solid line in the figure, and when an overcurrent flows through the motor 4 and the thermal relay 8 is activated as described above, the reset button 8a is pushed down to the broken line in the figure, and the thermal relay 8 is activated. Reset.

[Problem that the invention attempts to solve]

In the conventional electromagnetic switch as described above, the button case 13 has three buttons 5a, 6a, 8a.
The structure is complicated and requires a lot of man-hours to assemble, leading to an increase in costs.

The present invention was made to solve the above-mentioned problems, and its purpose is to obtain an electromagnetic switch which has a simple structure, a small number of parts, and is easy to assemble.

[Means for solving problems]

The present invention is an electromagnetic switch equipped with an electromagnetic contactor, a thermal relay, and a plurality of push button switches. The electromagnetic switch is constructed by molding a reset button on the tip of the thermal relay to be elastically displaced to reset the thermal relay.

[Effect]

Incorporate the button base into the cover of the electromagnetic switch,
Place the reset button opposite the button lever of the thermal relay.

〔Example〕

FIG. 1 is an exploded perspective view of essential parts of an embodiment of the present invention. In the figure, reference numeral 14 denotes a button base made of synthetic resin or the like, and is provided with contact mechanisms for a normally closed push button switch 5 and a normally open push button switch 6. Reference numeral 21 designates a reset button which is resin-molded integrally with the distal end of an arm 20 formed by a groove 19 in a part of the button base 14, and the arm 20 provides elasticity. Such a button base 14 attaches the push button 5a to the contact mechanism of the normally closed push button switch 5 via the spring 15, and attaches the push button 6a to the contact mechanism of the normally open push button switch 6 via the spring 16. is attached and housed in the button case 13. At this time, the push buttons 5a, 6
a are located in holes 17 and 18 provided in button case 13, respectively, and reset button 21 is located in hole 22.

When the button case 13 constructed as described above is attached to the cover 12 of the electromagnetic switch, the lower surface of the reset button 21 comes into contact with the reset lever 9 as shown in FIG. Therefore, as in the conventional example shown in FIG. 5, the thermal relay 8 can be reset by pressing the reset button 21. In this case, since the reset button 21 is provided with the groove 19, the stress caused by the operation can be reduced, and the components attached to the button base 14 will not be affected.

[Effect of idea]

As is clear from the above explanation, the present invention uses a reset button as a part of the button base to which the contact mechanisms of the normally closed push button switch and the normally open push button switch are attached, so the structure is simple and the number of parts is simple. Therefore, it is possible to obtain an electromagnetic switch which can be easily assembled and can reduce costs.

[Brief explanation of the drawing]

Fig. 1 is an exploded perspective view showing the main parts of the embodiment of the present invention, Fig. 2 is an explanatory diagram of its operation, Fig. 3 is a circuit diagram showing the state of use of the electromagnetic switch, and Fig. 4 is a conventional electromagnetic switch. Fig. 5 is a plan view thereof, and Fig. 5 is a longitudinal sectional view thereof. 5... Normally closed push button switch, 6... Normally open push button switch, 5a, 6a... Push button,
8...Thermal relay, 14...Button base,
21...Reset button. Note that the same reference numerals in the figures indicate the same or equivalent parts.

Claims (1)

[Scope of claim for utility model registration] An electromagnetic switch equipped with an electromagnetic contactor, a thermal relay, and a plurality of push button switches, wherein a part of the button base made of a resin material on which the contact mechanism of the push button switch is mounted has elasticity. 1. An electromagnetic switch characterized in that an arm is formed to be displaced in a direction, and a reset button for resetting the thermal relay is formed on the arm.