JPH0321079Y2 - - Google Patents

Description

[Detailed description of the invention] [Technical field of the invention] This invention is a 3-phase solid state relay (hereinafter referred to as 3-phase
(hereinafter referred to as phase SSR).

[Prior art]

Conventionally, when controlling the drive of a three-phase AC motor, an electromagnetic switch, which is a mechanical relay, is used to control the opening and closing of the electromagnetic switch, thereby controlling the supply of three-phase AC power to the motor. Ta. However, this electromagnetic switch has a problem in that under usage conditions where the electromagnetic switch is frequently opened and closed, its contacts become severely worn, resulting in a shortened lifespan.

By the way, conventional single-phase solid-state relays (hereinafter referred to as single-phase SSR) using semiconductors have been used to control the supply of single-phase AC power to loads. does not require a contact like the electromagnetic switch described above, and therefore there is no problem of shortened life due to wear of the contact.

Figure 1 shows the semiconductor main element circuit 80 of the single-phase SSR mentioned above.
In the figure, 81 and 82 are power supply side and load side main terminals, 83 and 84 are first and second thyristors, 85 and 86 are control terminals connected to a control circuit (not shown), and 87 and 88 are respectively These are first and second gate auxiliary circuits consisting of a resistor 89 and a diode 90.

When the control signal externally applied to the control circuit is "H", the control terminals 85, 86
As a result, in the positive half cycle of single-phase AC, the power supply side main terminal 81, the first gate auxiliary circuit 87, between the control terminals 85 and 86, the gate of the second thyristor 84, and the load side main terminal 82. An auxiliary current flows through the path, turning on the second thyristor 84,
As a result, the main current flows from the power supply side main terminal 81 through the second thyristor 84 to the load side main terminal 82,
Similarly, in the negative half cycle of single-phase AC, the second gate auxiliary circuit 88 and the first thyristor 83
operates, and the main current flows from the load side to the first thyristor 8.
3 to the power supply side, and as a result, single-phase power is supplied to the load.

On the other hand, when the control signal is "L", the control terminals 85 and 86 are in an open state, and as a result, both thyristors 83 and 84 remain off, and single-phase power is not supplied to the load. Therefore, if this single-phase SSR is used, the supply of single-phase power to the load can be controlled to be connected or disconnected using the control signal.

In such conventional situations, when controlling the supply of the three-phase AC power to the load, the single-phase SSR described above is used in combination with the electromagnetic switch instead of the three-phase AC power source.
It is believed that by configuring an SSR, it is possible to avoid the above problem of reduced lifespan.

[Summary of the idea]

The purpose of this invention is to provide a three-phase SSR that can solve the problem of shortened service life due to wear of the contacts in the electromagnetic switch in the conventional situation, is easy to assemble, and guarantees safety. It is said that

That is, this invention includes three semiconductor main element circuits that connect and disconnect the supply of three-phase AC power to a load, and a control circuit that turns on and off each of the main element circuits in response to external control signals. and an absorber circuit for protecting the main element circuit from abnormally high voltage, the case of the absorber circuit covering the soldered portions of both terminal leads of the semiconductor main element circuit and the control circuit. a skirt portion and a skirt portion that is formed integrally with a case housing the control circuit, is fitted into a U-shaped barrier surrounding the main terminal plate of the semiconductor main element circuit, and is used to position the case housing the absorber circuit; This structure allows easy positioning, prevents the soldering portion of the terminal lead from being exposed, and does not impede soldering workability.

[Example of idea]

2 to 6 show a three-phase SSR according to an embodiment of the present invention. In Fig. 2, 1 is a 3-phase AC power supply, 2 is a 3-phase AC motor as a load, 3 is a 3-phase cable connecting the 3-phase AC power supply 1 and the 3-phase AC motor 2, and 4 is the 3-phase cable 3. This is a 3-phase SSR installed in the middle.

In addition, Figures 3 to 6 show the detailed structure of the three-phase SSR described above, and 5 indicates three semiconductor main element circuits (see Figure 1) that connect and disconnect the supply of the three-phase AC power supply 1 to the load 2. It consists of a case 6 in which this is enclosed and fixed.
SSR main body, 7a to 7c and 7d to 7f are power supply 1
(or the load 2) and the main terminal boards 6a to 6f of the semiconductor main element circuit for connecting each line of the three-phase cable 3 from the load 2 (or the power source 1) are formed integrally with the case 6, and the main terminals are U-shaped barriers surrounding plates 7a to 7f, 7g and 7h are barriers 6a to 6
These are the control terminal leads of the semiconductor main element circuit (however, only one set is shown in the figure) that protrude above the case 6 between the lines 6a and 6d and on the left side of the barriers 6a and 6d in FIG. Further, reference numeral 8 denotes a control circuit 8a, 8b mounted on the SSR main body 5, which controls on/off the semiconductor main element circuit according to an external control signal.
are the input terminal leads of the control circuit 8 screwed to the case 6 and into which control signals are input; 8c and 8d are the output terminal leads of the control circuit 8 which are soldered to the control terminal leads 7g and 7h of the semiconductor main element circuit ( However, only one set appears in the figure).

Further, 9 is an absorber circuit mounted on the control circuit 8 to protect the semiconductor main element circuit from abnormal high voltage such as surge voltage, and 10 is screwed to the case 6 of the SSR main body 5 to house and fix the absorber circuit 9. The cases 10a to 10f are integrally formed with the case 10, and the skirt parts 10g to 10l are fitted into the barriers 6a to 6f of the case 6 of the SSR main body 5 to position the absorber circuit 9. This skirt portion covers the soldered portions of the output terminal leads 8c, 8d of the control circuit 8 and the control terminal leads 7g, 7h of the semiconductor main element circuit.

In the device of this embodiment having the above configuration,
First, since a 3-phase SSR using semiconductors is configured to control the supply of 3-phase AC power to the load, it is possible to solve the problem of reduced lifespan due to contact wear.

In addition, in such a three-phase SSR, if the absorber circuit is simply mounted on the control circuit, it is difficult to position the control circuit and the absorber circuit, and the control terminal lead of the semiconductor main element circuit and the output of the control circuit are difficult to locate. The problem arises that the soldered part of the terminal lead is exposed to the outside and is dangerous.In order to solve this problem, positioning means and covering means are provided on the control circuit side, but the soldering work is The problem arises that it becomes difficult. However, in this device, the position of the absorber circuit is determined by the skirt part of the case of the absorber circuit and the barrier of the case of the SSR body, so the absorber circuit is already in the correct position when it is mounted on the control circuit. arrangement and therefore very simple to assemble. In addition, the parts of the terminal leads to be joined are exposed before the absorber circuit is installed, so the soldering work is easy, and after the absorber circuit is installed, the soldered parts are covered by the skirt of the case. and safety can be guaranteed.

[Effect of idea]

As described above, according to the present invention, a three-phase SSR is configured with three semiconductor main element circuits, which not only solves the problem of short lifespan of conventional electromagnetic switches, but also enables the three-phase SSR to A skirt portion that covers the soldered portion of the terminal lead in the case of the absorber circuit, and a U-shaped barrier that is formed integrally with the case that houses the control circuit and surrounds the main terminal plate of the semiconductor main element circuit, and are fitted into the case of the absorber circuit. Since a skirt part is formed for positioning the case that houses the circuit, the case can be easily positioned, and the soldered part of the terminal lead can be prevented from being exposed. This has the effect that the workability of the machine is not hindered.

[Brief explanation of the drawing]

Figure 1 is a circuit configuration diagram of a conventional single-phase SSR semiconductor main element circuit, and Figure 2 is a circuit diagram of a semiconductor main element circuit of a conventional single-phase SSR.
Figures 3 and 4 are circuit diagrams showing the connection relationship with the power supply and load when the phase SSR is in use.
A plan view and a side view of the SSR, FIGS. 5a and 5b are a sectional view along the line AA and BB in FIG. 3, and FIG. 6 is an exploded perspective view of the three-phase SSR. 5...SSR main body (semiconductor main element circuit), 8...
Control circuit, 9... Absorber circuit, 10... Case, 10a to 10f, 10g to 10l... Skirt portion. Note that the same reference numerals in the figures indicate the same or equivalent parts.

Claims (1)

[Scope of claim for utility model registration] Three semiconductor main element circuits that disconnect and disconnect the supply of three-phase AC power to a load, and a control circuit that turns on and off the semiconductor main element circuits in response to external control signals. and an absorber circuit for protecting the main element circuit from abnormally high voltage, the case housing the absorber circuit having an output terminal lead of the control circuit and the main element circuit. a skirt portion that covers a connecting portion with a control terminal lead of the element circuit; and a U-shaped barrier that is formed integrally with the case that houses the control circuit and surrounds the main terminal plate of the semiconductor main element circuit; A three-phase solid state relay characterized in that a skirt portion is formed for positioning a case housing a circuit.