JPH04220920A - Switch device - Google Patents

Abstract

PURPOSE:To simplify wring works by entering a switch signal based on the operating amount of an actuator and a failure signal generated from diagnosis of switch failure, and emitting analog signals having output levels in compliance with these signals. CONSTITUTION:When an actuator 1 is operated and the operating amount sensing signal from a sensing part 2 attains the set level, a switch circuit 4 emits a switch signal. In case any failure has occurred in the actuator 1 or there is a signal emission from a water sensing part 5, diagnostic circuits 6a, 6b issue a failure signal. These switch signal and failure signal are fed to an output circuit 8, which emits analog signals having the output levels corresponding to the respective fed signals. Thereby the switch output signal and failure sensing signal can be drawn out through the same signal line, which should simplify wiring works.

Description

[Detailed description of the invention]

0001

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a switch device used for object detection such as a limit switch.

0002

[Prior Art] For example, in the case of a limit switch, the lever of the actuating body that comes into contact with an object may not return properly, or water may enter the limit switch and cause insulation failure in the circuit section. If this occurs, the switch enters a so-called failure state and a normal switch signal cannot be obtained.

[0003] Therefore, a failure detection mechanism is provided in the limit switch so that these signals are separately extracted and an alarm is issued by an alarm device.

0004

[Problems to be Solved by the Invention] Therefore, in the conventional switch device, it is necessary to wire each of the failure detection signal lines in addition to the switch output signal line to the switch device, making the wiring structure complicated and making wiring work extremely difficult. There was a problem that required time and effort.

The present invention has been made in view of the above circumstances, and an object of the present invention is to provide a switch device in which a switch output signal and a failure detection signal can be drawn out through the same signal line, and wiring can be easily performed. shall be.

[0006]

[Means for Solving the Problems] In order to achieve such an object, the present invention provides a switch device including an actuating body that is actuated by contact with an object, and an actuation detection means that detects the amount of actuation of the actuating body. a switch signal output means for outputting a switch signal based on the operation amount detection signal from the operation detection means; a failure signal output means for diagnosing a failure of the switch and outputting a failure signal; and the switch signal and the failure signal. and an analog signal output means for outputting an analog signal having an output level corresponding to each signal.

[0007]

[Operation] According to this configuration, an analog signal having an output level corresponding to the switch signal and the failure signal is outputted.

[0008]

Embodiments Hereinafter, embodiments of the present invention will be described in detail with reference to the drawings. FIG. 1 is a block circuit diagram of a switch device according to the present invention, and the switch device S includes an actuating body 1 that is actuated by contact with an object, and an actuation detecting section 2 that serves as an actuation detecting means for detecting the amount of actuation of the actuating body 1. , a switch circuit 4 as a switch signal output means that outputs a switch signal based on the operation amount detection signal from the operation detection section 2, and a water detection section 5.
, diagnostic circuits 6a and 6b as failure signal output means for diagnosing a failure and outputting a failure signal based on the detection signals from the respective detection units 2 and 5, and from the switch circuit 4 and the diagnosis circuits 6a and 6b, respectively. The power supply circuit 10 includes an output circuit 8 as an analog signal output means for outputting analog signals having output levels corresponding to the respective signals based on the switch signal and the failure signal, and a power supply circuit 10.

Reference numeral 12 indicates a discriminating circuit for analog signals output from the output circuit 8 of the switch device S, and numeral 14 indicates a discriminating circuit 12.
This is a control device that outputs a switch signal and a failure signal to a device to be controlled based on a determination signal from the device.

The operation detection section 2 is composed of a light reflection sensor, a potentiometer, etc., and outputs a current signal and a resistance value signal as an operation amount detection signal in accordance with the displacement of the operation mechanism inside the switch linked to the operation body 1. The water detection section 5 is constituted by a pair of electrode plates disposed relative to each other in the lower part of the interior of the switch, and outputs a water detection signal when water enters the interior of the switch and conduction occurs between the respective electrodes.

Next, the analog signal output operation of the switch device S will be explained with reference to FIG.

[0012] When the actuating body 1 operates normally and no water has entered the switch device S, when the actuating body 1 is stopped at the initial position, the output circuit 8 drains the current consumed within the circuit. For example, it outputs 5mA as an analog signal. Then, when the actuating body 1 is actuated and the actuation amount detection signal from the actuation detection section 1 reaches a set level, the switch circuit 4
A voltage signal (ON), which is a switch signal, is output. FIG. 2 shows the internal configuration of the output circuit 8. When a voltage signal is applied to the transistor 20a, a current of, for example, 8 mA flows, thereby outputting an analog signal of a total of 13 mA.

On the other hand, when a malfunction occurs in the actuating body 1 and the actuating body 1 does not return completely to the initial position or rotates too much, a failure signal is output from the diagnostic circuit 6a. Similar to the transistor 20a described above, a current of 4 mA flows through the transistor 20b. Therefore, when a failure occurs due to malfunction, the operating body 1
If it does not return to its initial position completely, a total of 9 mA is output, and if it rotates too far, a total of 17 mA is output.

If there is a detection signal from the water detection unit 5, a failure signal is output from the diagnostic circuit 6b, and in this case, the transistor 20c flows 2mA. Therefore, if there is no malfunction in the operating body 1, Currents of 7mA and 15mA are output as the actuator 1 operates, whereas if the actuator 1 has a malfunction, currents of 11mA and 19mA are output.
The current is output.

As described above, the output circuit 8 outputs signals 5, 7, 9, 11, 13, 15 related to malfunctions of the actuating body 1 and water intrusion as the actuating body 1 operates. ,17,
It outputs an analog signal including 8 output levels of 19 mA. In other words, the switch output signal and failure detection signal can be output by one line (actual wiring requires a power supply line and becomes two lines). It becomes possible.

The determination circuit 12 to which this switch device S is connected determines whether the analog signal falls within each setting range as shown in FIG. 3, and sequentially sends the determination signal to the control device 14. . In the determination operation here, if a signal with an output level in the water detection area, failure prediction area, or water detection failure prediction area between the normal OFF area and normal ON area is obtained, the obtained time is compared with the set value. However, the determination signal is output only when the set value is reached, so that the fault signal is not output when the output value simply passes through that level as the operating body 1 operates. ing. In addition, in the discrimination circuit 12, if the output current is 4 mA or less, the circuit in the switch device S is disconnected, and the 2
If it is 0 mA or more, a determination signal indicating that the circuit within the switch device S is short-circuited is output. Then, the control device 14 appropriately outputs a switch output signal and a failure detection signal in response to the applied discrimination signal, thereby operating the device to be controlled and issuing a failure alarm.

The output level of the analog signal from the switch device S may be set as appropriate, and correspondingly, as shown in FIG. The settings may be made accordingly.

FIG. 5 is a wiring diagram when a plurality of switch devices S are used. In this device, a communication circuit 30 is used between a plurality of discrimination circuits 12 and the control device 14, so that the discrimination circuit 12 and the control device 14 can be connected to each other. The structure can be simplified by using one line of wiring between the two.

[0019]

[Effects of the Invention] As explained above, according to the present invention,
An analog signal having an output level corresponding to the switch signal and the fault signal is now output, and as a result, the switch output signal and the fault detection signal can be drawn out through the same signal line, and a switch device can be easily wired. can get.

[Brief explanation of the drawing]

FIG. 1 is a block circuit diagram of the present invention.

FIG. 2 is a circuit diagram of the output circuit shown in FIG. 1.

FIG. 3 is a correlation diagram between the output current and the operating amount of the operating body.

FIG. 4 is a correlation diagram of another embodiment between the output current and the actuation amount of the actuator.

FIG. 5 is a wiring diagram when a plurality of switch devices are used.

[Explanation of symbols]

1 Working body

Claims (1)

[Claims] [Claim 1] An actuating body (
1), an operation detection means (2) for detecting the amount of operation of the actuation body (1), and a switch signal output means (2) for outputting a switch signal based on the amount of operation detection signal from the operation detection means (2). 4), fault signal output means (6a) (6b) for diagnosing a fault in a switch and outputting a fault signal, and having an output level corresponding to each signal when the switch signal and the fault signal are given. A switch device comprising an analog signal output means (8) for outputting an analog signal.