JPS6314362B2 - - Google Patents

Description

DETAILED DESCRIPTION OF THE INVENTION The present invention relates to a printed circuit board device in which the operating states of a large number of output relays mounted on a printed circuit board are extracted to the outside through normally open contacts or normally closed contacts.

In an arithmetic control device such as a sequence controller, output commands are output to the outside through a large number of output relays mounted on a printed circuit board. The operating state of the output relay is taken out to the outside by electrically connecting a normally open contact or a normally closed contact to an external terminal block attached to the front panel of the printed circuit board. Electrical connection between the output relay and the external terminal block is usually made by inserting the pins of the external terminal block into pin holes drilled in the printed circuit board.

Incidentally, the output relay is used, for example, as a start command and a stop command for the electric motor. A normally open contact is used as a start command, and a normally closed contact is used as a stop command. In this case, whether the output relay is used as a start command or a stop command depends on how the arithmetic and control device is used. Therefore, it is necessary to enable each output relay to be used for both start and stop commands. For this purpose, both a normally open contact and a normally closed contact for one output relay must be electrically connected to an external terminal block. When connecting the normally open contacts and normally closed contacts of one output relay to an external terminal block, at least three terminals are required on the external terminal block for one output relay. The external terminal block is attached to the front panel of the printed circuit board, but if there are many output relays, the number of terminals used will also increase.
Therefore, the length of the external terminal block increases.

On the other hand, an arithmetic and control device is constructed by inserting and fixing a large number of printed circuit boards into a housing. In order to miniaturize the arithmetic and control device, the size of the front panel is also limited, and as a result, the size of the terminal block (number of terminals) must also be made as small as possible.

Now, in order to reduce the number of terminals on the external terminal block and make it more compact, connect only one of the normally open or normally closed contacts of the output relay to the external terminal block, and install an auxiliary relay in the motor control circuit to make the required stop. It is proposed to obtain a command or activation command. In this way, the number of terminals used on the external terminal block of one output relay becomes two.

Specifically, when only the normally open contact of the output relay is used, an auxiliary relay that is energized when the normally open contact of the output relay is turned on is provided in the motor operation circuit.
The output relay is energized when the stop condition is met. Then, the normally closed contact of the auxiliary relay, which is activated by the excitation of the output relay, is used as a stop command. However, it has the disadvantage that it is not economically advisable because it requires as many auxiliary relays as the number of output relays.

In this case, if the output relay for taking out the stop command to the outside is always energized and de-energized when the stop condition is satisfied, there is no need to use an auxiliary relay. However, if the operating power of the output relay is lost, the motor that is in operation will stop operating, so it cannot be put to practical use in terms of reliability.

On the other hand, when only the normally closed contact of the output relay is used, an auxiliary relay is installed that is energized when the normally closed contact of the output relay is turned off in order to obtain a start command, and when the start condition is met, the output relay is operated to provide assistance. Use the normally open contact of the relay as the start command. However, the need to use an auxiliary relay is just the same as using only normally open contacts.

Further, in order to eliminate the need for an auxiliary relay when only this normally closed contact is used, this can be done by energizing the output relay at all times and de-energizing the output relay when the starting conditions are met. However, this has the disadvantage that a stopped motor starts when the operating power of the output relay is lost.

As described above, in the conventional printed circuit board device, if the number of terminals on the external terminal block of the output relay is reduced, there are problems in terms of economy and reliability, and there are practical problems.

The present invention has been made to address the above-mentioned problems, and its purpose is to provide a printed circuit board device that is economical and reliable even when the number of terminals on the external terminal block is small.

A feature of the present invention is that a contact selection switching means is mounted on the printed circuit board to select either the normally open contact or the normally closed contact of the output relay mounted on the printed circuit board and connect it to an external terminal block. By switching the selection switching means, any one of the normally open contact and the normally closed contact can be connected to the external terminal block.

An embodiment of the present invention will be described below with reference to FIGS. 1 to 3.

FIG. 1 is a perspective view of two printed circuit boards 1 arranged side by side, and a front panel 2 is fixed to one end side in the illustrated height direction. An external terminal block 3 and operation indicator lamps 4 for output relays 81 to 8n are attached to the front panel 2. The state of the output relay is taken out from the external terminal block 3 via the connection line 5.

On the other hand, in area A of the mounting surface of printed circuit board 1, electronic equipment 7 constituting a drive circuit for driving output relays 81 to 8n is mounted, and in area B, a large number of output relays 81 to 8n are mounted. . In area C between area B and front panel 2, selection switches 9 corresponding to the number of output relays 81 to 8n are mounted. Electronic equipment 7, output relays 81 to 8n
Electrical connections between the selection switches 91 to 9n are made by printed wiring. Also, printed circuit board 1
To connect the external terminal block 3, connect the pins (not shown) attached to the terminal block 3 to pin holes H11, H12, H21...
This is done by inserting it into Hn2. Indicator light 4
A lead wire (not shown) is used between the two.

A plurality of printed circuit boards 1 having such a configuration are inserted and fixed into a casing (not shown) to constitute an arithmetic and control device.

Output relay 81~ mounted on printed circuit board 1
8n and selection switches 91-9n are electrically connected as shown in FIG.

In Fig. 3, n output relays 81 to 8n and transistors Q1 to Qn are connected between the operation power supply buses P and N.
are connected in series, and flywheel diodes D1 to Dn are connected in parallel with the output relay 8. The transistors Q1 to Qn are controlled on and off by a drive circuit constituted by an electronic device 7. The drive circuit selects which transistor Q1 according to the control signal input from the connector 1A of the printed circuit board 1.
~ Turn on Qn, that is, output relays 81 to 8
Decide whether to excite n. Output relay 81~8n
Output contacts 81c~8nc and selection switches 91~
9n is connected as follows. Note that the output contacts of the output relay and the selection switch are shown in the form of transfer contacts (C contacts). Output relay 8
The a end (normally open contact) of the output contact 81c of the output relay 81 is connected to the a end of the selection switch 91, and the b end of the output contact 81c of the output relay 81 is connected to the b end of the selection switch 91. The output contacts 82c to 8nc of the other output relays 82 to 8n and the selection switches 92 to 9n are also connected in the same manner. And output relay 81~
Connect the C end of 8n to the terminals TB11, TB21... of the external terminal block 3 via the pin holes H11, H21...Hn1.
Connect to TBn1 and select switch 91~9n
Connect the c end of the external terminal block 3 to the terminals TB12, TB22...TBn2 through the pin holes H12, H22...Hn2.
Connect to.

One embodiment of the present invention has the above-mentioned configuration, and when the output relay 81 is output with a normally open contact, it is sufficient to close the selection switch 91 to the a end, and the number of terminals used on the external terminal block 3 is two. I can do it. Further, when the output relay 82 outputs a normally closed contact, any selection can be made simply by closing the selection switch 92 to the b end.

In this way, by simply switching the selection switches 91-9n provided corresponding to the output relays 81-8n, it is possible to obtain the contact output of any one of the normally open contacts and the normally closed contacts.

FIG. 4 shows an example of a drive control device for driving an induction motor using the contact output of the output relay obtained according to the present invention.

In Fig. 4, IM is an induction motor, including a thermal relay 49, an electromagnetic contactor 52, and a wiring cutter.
Connected to power supply via FFB. R and T are operation power bus bars, PBS ₁ and PBS ₂ are push button switches for starting or stopping, COS is a switching switch that switches between independent operation and interlocked operation by the arithmetic control unit, 49
b is the normally closed contact of the thermal relay 49, 52c is the closing coil of the electromagnetic contactor 52, and 52a is the electromagnetic contactor 52.
A normally open contact 81a is a normally open contact of the output relay 81 and is used as a start command. 82b is a normally closed contact of the output relay 82 and is used as a stop command.
Contacts 81a and 82b surrounded by two-dot chain lines connect between terminals TB12 and TB21 of the external terminal block 3 shown in FIG.
Connect to PBS ₂ . As a result, the contact output is taken out to the outside.

The operation shown in Figure 4 is well known and a detailed explanation will be omitted, but when the induction motor IM is operated in conjunction with other motors by the arithmetic and control unit, the switching switch COS is closed to the interlocking side. . At this time, the wiring sheath breaker FFB is closed. In this state, the third
When the transistor Q1 shown in the figure is turned on and the output relay 81 is excited, its output contact 81c is closed to the a terminal. The output relay 81 outputs its state through a normally open contact 81a. When the contact 81a is closed, the electromagnetic contactor 52 is energized to close the closing coil 52c.
At the same time, the electromagnetic contactor 52 maintains itself by closing the normally open contact 52a. The electric motor IM is started by closing the electromagnetic contactor 52.

When the motor IM is being driven in such a state, when the transistor Q2 in FIG. 3 is turned on and the output relay 82 is energized, its output contact 82c becomes a
The circuit closes at the end. As a result, the normally closed contact 82b is opened, so that the closing coil 52c is de-energized. Therefore, since the electromagnetic contactor 52 is opened, the electric motor
IM will stop.

Note that when switching switch COS is switched to the independent side, the motor IM can be started and stopped using the push button switch.
Performed by PBS ₁ and PBS ₂ .

The application example of the present invention has been described above, but even if the number of terminals used on the external terminal block is two to take out the output relay to the outside with a normally open contact or a normally closed contact, output can be made with any contact. As a result, this can be done economically without the need for an auxiliary relay, and even when the power to the arithmetic and control device is lost, malfunctions of the controlled equipment can be reliably prevented.

FIG. 5 shows another embodiment of the present invention, in which the output contacts of output relays 81 to 8n are normally open contacts 81a.
This is an example where the normally closed contacts 81b...8nb are provided independently.

In the embodiment shown in FIG. 5, the output relays 81 to 8
It is obvious that the contact output of n can be switched arbitrarily.

Next, FIG. 6 shows still another embodiment of the present invention, in which selection and switching between a normally open contact and a normally closed contact of an output relay is performed using a terminal block.

The difference in Fig. 6 from Fig. 2 is that a printed circuit board mounting terminal block (relay terminal block) 10 is mounted in area C, and one relay terminal block 10 is mounted for one output relay.
Switching is performed using three terminals and a shorting fitting 12.

As shown in FIG. 7, the terminal block 10 for mounting a printed circuit board has a conductive stud 13 embedded in an insulating base 10A so as to protrude from the bottom surface, and a screw 15 is screwed into a screw hole drilled in the stud 13. Then, tighten the conductive metal fittings 16. The protruding portion of the lower surface of the stud 13 is inserted into a through hole of the printed circuit board 1 and soldered.

Connect the terminals of the relay terminal block 10 to T1 and T as shown in Figure 7.
2, T3, the terminal T2 is connected to the pin hole H12 of the printed circuit board 1 by printed wiring as shown in FIG. In addition, c of the output contact 81c of the output relay 81
Connect the end to pin hole H11. Other output relay 8
The output contacts 2 to 8n and the three terminals of the relay terminal block 10 are also connected in the same manner. In addition, in FIG. 8, the terminals T1 to T3 of the relay terminal block 10 used for the output relays 82 to 8n are different terminals,
The same reference numerals are given for convenience of explanation.

When a normally open contact is obtained as the output contact of the output relay 81 with this configuration, the terminals T2 and T3 of the relay terminal block 10 are short-circuited with the short-circuit fitting 12 as shown in FIG. Further, when obtaining a normally closed contact as the output contact of the output relay 82, the terminals T1 and T2 of the relay terminal block 10 are short-circuited with a short-circuiting fitting.

In this way, the output contacts can be selected and switched using the terminal block as well. According to this embodiment, once the short-circuiting fitting is attached, there is no need for contact by maintenance personnel or the like to switch the fitting, so reliability can be improved.

Next, FIG. 9 shows another embodiment of the present invention, in which a pattern 20 is printed on the printed circuit board 1, and connections between c and a or between c and b are made to provide the required contact output. The same operation can be performed even if the lead wire 21 is used for connection. Note that if the dotted lines are printed between ca and cb of the pattern 20, it can be easily determined when connecting with the lead wire 21. Also, the a, b, c ends of the pattern 20 are made through holes,
A plug may be used to short-circuit between c and a or between c and b.

As explained above, in the present invention, either the normally open contact or the normally closed contact of the output relay can be arbitrarily taken out even if the number of terminals used on the external terminal block is two. Therefore, since no auxiliary relay is required, this can be done economically, and even when the power to the arithmetic and control unit is lost, malfunctions of the controlled equipment can be reliably prevented.

[Brief explanation of the drawing]

Figures 1 to 3 are diagrams showing one embodiment of the present invention, where Figure 1 is a perspective view, Figure 2 is a layout diagram of components mounted on a printed circuit board, and Figure 3 shows the electrical connection state of mounted components. 4 is a circuit diagram showing an example of application of the present invention, FIG. 5 is a circuit diagram showing another embodiment of the present invention, and FIGS. 6 to 8 are circuit diagrams showing still other embodiments of the present invention. FIG. 6 is a component mounting arrangement diagram of a printed circuit board, FIG. 7 is a partially enlarged sectional view of a relay terminal block, FIG. 8 is a circuit diagram showing the electrical connection state of mounted components, and FIG. 9 is a diagram showing an embodiment. The figure is a circuit diagram showing another embodiment of the present invention. DESCRIPTION OF SYMBOLS 1... Plant board, 2... Front panel, 3... External terminal block, 81-8n... Output relay, 91-9n... Changeover switch, 10... Relay terminal block.

Claims (1)

[Claims] 1. Normally open contacts or normally closed contacts of a large number of output relays mounted on a printed circuit board are connected to an external terminal block attached to the front panel of the printed circuit board, and the operating status of the output relays is communicated to the outside. The printed circuit board device is characterized in that output contact selection means for selecting either a normally open contact or a normally closed contact of the output relay and connecting it to the terminal block is mounted on the printed circuit board. Printed circuit board equipment. 2. The printed circuit board device according to claim 1, wherein the output contact selection means is a changeover switch. 3. The printed circuit board device according to claim 1, wherein the output contact selection means comprises a relay terminal block and a shorting fitting that shorts between the terminals of the relay terminal block.