JPH0670996U - Relay contact monitor circuit in press machine - Google Patents

Abstract

(57) [Abstract] [Purpose] When the relay contacts are welded, the abnormality is easily detected, the configuration is simple, and the operation is reliable. [Structure] When the contacts of relays CR1 and CR2 that are input to confirm the input status to the sequencer PC are composed of normally closed contacts, and the relays CR1 and CR2 are composed of multiple contacts and one of them is welded Also, the other contact holds the open state.

Description

[Detailed description of the device]

[0001]

[Industrial applications]

 The present invention relates to a relay contact monitor circuit using a sequencer in a press machine.

[0002]

[Prior art]

 FIG. 3 shows a relay contact monitor circuit diagram using a conventional sequencer. FIG. 3A is a solenoid operation relay connection diagram, and FIG. 3B is a sequencer connection diagram for monitor output to FIG. . In the figure, CR1 is an operation recovery confirmation relay, CR2 is an operation relay, B35 is a monitor output, SOL is a clutch solenoid of a press machine, and PC is a sequencer for controlling output according to a pre-programmed command sequence according to input conditions. For the relays CR1 and CR2, safety relays are used in which one contact is welded and the other contacts are kept open. In the case of the two-hand push button type, the clutch solenoid SOL is excited only when both hands are pushed simultaneously.

Further, in addition to the two-hand push button type described above, the present invention can be similarly applied to the one-hand push button type or the foot (foot switch) type.

In this conventional circuit, since the operations of the relays CR1 and CR2 are not turned on at the same time, as shown in Table 1, the simultaneous turning on (indicated by *) is detected as an abnormality.

[0005]

[Table 1] Therefore, when the relays CR1 and CR2 are turned on at the same time, the monitor inputs B5 and B6 of the sequencer PC are turned on at the same time, which is detected as an abnormality and the monitor output B35 is turned off.

[0006]

[Problems to be solved by the device]

 By the way, when considering the welding of the contacts of the relays CR1 and CR2, there are multiple contacts of the relays CR1 and CR2. Therefore, when the A contact of another relay not connected to the sequencer PC is welded, the abnormality is detected. There was a problem that I could not do it. The statuses of the monitor inputs B5 and B6 of the sequencer PC are as shown in Table 2, and there is a risk that if the monitor inputs B5 and B6 are turned on at the same time *, there is no abnormality and they are pressed with one hand. In addition, ON / OFF in the table indicates ON or OFF.

[0007]

[Table 2] The object of the present invention is to solve the above-mentioned problems, and even when the contact of a relay composed of an A contact which is normally open and closes when an external force is applied is welded, the abnormality can be easily detected. It is an object of the present invention to provide a relay contact monitor circuit in a press machine whose structure is simple and whose operation can be surely confirmed.

[0008]

[Means for Solving the Problems]

 In order to achieve the above object, the present invention, in a press machine in which a solenoid for a clutch is excited by a switch when a switch is turned on to operate, a contact point of a relay which is input to confirm an input state to the sequencer is always provided. A relay contact monitor circuit in a press machine, characterized in that even if any one of the relays composed of multiple contacts is welded, the other contact is kept open. is there.

[0009]

[Action]

 By adopting the relay contact monitor circuit in the press machine of the present invention, the contact of the relay for inputting in order to confirm the input state to the sequencer is constituted by the normally closed contact, and any one of the relays constituted by the plurality of contacts is constituted. Even if one of the contacts is welded, the other contacts are kept open so that when the relay contacts are welded, the abnormality can be easily detected, and the configuration is simple. The operation is surely confirmed.

[0010]

【Example】

 Hereinafter, embodiments of the present invention will be described in detail with reference to the drawings.

FIG. 1 shows a relay contact monitor circuit diagram using a sequencer according to an embodiment of the present invention. FIG. 1A is a solenoid operation relay connection diagram, and FIG. 1B is a monitor shown in FIG. It is a sequencer connection diagram for outputting. In the figure, monitor inputs B5 and B6 to the sequencer PC are composed of the B contacts of the operation recovery confirmation relay CR1 and the operation relay CR2. The operation status is shown in Table 3. In Table 3, abnormality is detected when both monitor inputs B5 and B6 are OFF (indicated by *).

[0012]

[Table 3] The relays CR1 and CR2 are composed of a plurality of contacts. When the A contact of relay R1 is welded and one B contact is improperly closed, when this B contact is * 1 in Fig. 1, monitor input B5 is OFF, and when both contacts are pressed, monitor input B6 is OFF. Therefore, abnormalities can be detected.

When the B contact that is not properly closed is another contact instead of * 1 in FIG. 1, even if one contact of this relay is welded, the other contact remains open, so the sequencer P The monitor input B5 of C is turned off, and an abnormality can be detected.

FIG. 2 shows a relay contact monitor circuit diagram using a sequencer according to another embodiment of the present invention. FIG. 2A is a connection diagram of a plurality of simultaneous operation target operation relays, and FIG. Is a sequencer connection diagram for monitor output to (A) of the same figure. In the figure, even if there are three or more objects to be simultaneously turned on, and in the case of the stroke changeover switch of the inching, safety one stroke, one stroke and continuous four strokes in this embodiment, the monitor input to the sequencer PC is constituted by the B contact. Especially, monitoring is possible. Table 4 shows the normal operating state of the relay. The minimum number of OFF states is one when normal, but the number of OFF states is two or more when abnormal.

[0015]

[Table 4] As described above, by changing the contacts of the input relays CR1, CR2, CR11 to CR14 of the sequencer PC from the conventional A contacts to the B contacts, the monitor inputs B5, B6, B0 to B3 of the sequencer PC are turned off at the same time. When this happens, the monitor circuit is configured to detect the abnormality, and even if the other contact of the relay not connected to the sequencer PC is welded, the abnormality can be detected.

The present invention is not limited to the above-mentioned embodiments, but can be implemented in other modes by making appropriate design changes.

[0017]

[Effect of device]

 As is clear from the above description, the relay contact monitor circuit in the press machine of the present invention comprises a normally-closed contact for the relay input to confirm the input state to the sequencer. Even if one of the contacts is welded, the other contact holds the open state, which effectively solves the problem of the conventional technology. Can be easily detected, its configuration is simple, and its operation can be reliably confirmed.

[Brief description of drawings]

FIG. 1 shows a relay contact monitor circuit diagram using a sequencer according to an embodiment of the present invention. FIG. 1A is a solenoid operation relay connection diagram, and FIG. 1B is monitor output to FIG. 1A. It is a sequencer connection diagram.

FIG. 2 shows a relay contact monitor circuit diagram using a sequencer according to another embodiment of the present invention. FIG. 2A is a connection diagram of a plurality of simultaneous operation target operation relays, and FIG. (A)
It is a sequencer connection diagram for monitor output to.

FIG. 3 is a relay contact monitor circuit diagram using a conventional sequencer, FIG. 3A is a solenoid operated relay connection diagram, and FIG. 3B is a sequencer connection diagram for monitor output to FIG. .

[Explanation of symbols]

 CR1 Run recovery confirmation relay CR2 Run relay PC Sequencer SOL Clutch solenoid

Claims (1)

[Scope of utility model registration request] 1. In a press machine in which a solenoid for a clutch is excited by a switch when a switch is turned on to operate, a contact of a relay input to confirm an input state to the sequencer is constituted by a normally closed contact, and a plurality of contact points are provided. A relay contact monitor circuit in a press machine, wherein when one of the relay contacts is welded, the other contact remains open.