JPH0743885Y2 - Mat switch device - Google Patents

Description

DETAILED DESCRIPTION OF THE INVENTION [Industrial field of use] The present invention relates to a mat switch device, and more particularly to a mat switch device in which a switch is brought into a conductive state when a load is applied to the mat.

[Conventional technology]

Conventionally, a mat switch device is used in order to ensure safety during operation of a machine such as a processing machine. Normally, as shown in FIG. 2, the mat switch device 20 is a machine switch.
It is installed near 23. Then, while the machine 23 is operating, the person 22 approaches the machine 23 and the mat of the mat switch device 20
When riding on 21, any one of a large number of switches (not shown) built in the mat 21 becomes conductive due to the applied load. As a result, the machine 23 is stopped, so that the safety of the person 22 can be ensured.

This mat switch is generally composed of a lower plate installed on the floor and an upper plate opposed to the lower plate at a predetermined distance, and a thin copper plate on each of the facing faces of the upper plate and the lower plate. A plurality of pairs of contact plates are arranged in a pair so as to face each other. Then, each contact plate of the upper plate and each contact plate of the lower plate are electrically connected in parallel, and each contact plate pair is in a non-contact state under no load condition, but a person rides on the upper plate. When a load is applied, the part is deformed, and the contact plate pair in the deformed part comes into contact with the mat switch to turn on.

3 and 4 are conventional mat switch devices 3 respectively.
Shows a 0,40, Figure 3 is two-terminal type mat switch of a plurality MS2 ₁ ~MS2 _n, is the fourth of FIG is to set up a plurality of four-terminal type mat switch MS4 ₁ ~MS4 _n.

Each of the two-terminal type mat switches MS2 _{1 to} MS2 _n in the mat switch device 30 of FIG. 3 is connected in parallel with a plurality of switches that are turned on when stepped on, and is connected to two terminals A and B. Then, each mat switch MS2 _{1 to} MS2 _n
The terminals A and B are connected in parallel and are connected to the DC power source E via the coil L1 of the relay CRIX. In this mat switch device 30, when a person gets on one of the mat switches MS2 _{1 to} MS2 _n , at least one of the mat switches MS2 _i (i is 1 to n) is turned on, and the relay CR
The coil L1 of IX is energized and the normally closed relay contact P1 is turned off. Therefore, if this relay contact P1 is incorporated in the drive circuit of the mechanical device, the mechanical device stops when the mat switch device 30 is stepped on.

Each of the four-terminal type mat switches MS4 _{1 to} MS4 _n in the mat switch device 40 of FIG. 4 is connected in parallel with a plurality of switches which are turned on when stepped on, and four terminals A, B, C,
Contacted D. And each mat switch MS4 _1- M
Adjacent terminals A and C and terminals B and D of S4 _n are connected, and the mat switches MS4 _{1 to} MS4 _n are connected in tandem. In addition, the DC power supply E is placed between the terminals A and B of the mat switch MS4 _1.
And the resistor R are connected in series, and the coil L2 of the relay CR2X is connected between the terminals C and D of the mat switch MS4 _n . In the mat switch device 40, the current from the DC power source E always flows through the coil L2 of the relay CR2X, and when a person rides on any of the mat switches MS4 _{1 to} MS4 _n , the mat switch MS4 _i (i is 1). At least one of the switches n to n) is turned on and the DC power source E is short-circuited by this switch, so that the coil L2 of the relay CR2X is de-energized and the normally closed relay contact P2 is turned off. Therefore,
If this relay contact P2 is incorporated in the drive circuit of the mechanical device, the mechanical device will stop when the mat switch device 40 is stepped on.

FIG. 5 shows the configuration of a conventional operation preparation circuit 50 provided in the power supply circuit of the mechanical device M. In the figure, 51 is an emergency stop button, 52 is a contact called a safety plug provided on a door of a protective wall provided around the machine M, 53 is a start button, 54 is a switch that is turned off during automatic operation, 55 is a normally closed switch that turns off when the mat switch is stepped on, CRIM is a relay, L3 is a relay coil, P3, P
4 is a relay contact. By connecting the relay contact P1 or P2 shown in FIG. 3 or 4 to the operation preparation circuit shown in FIG. 5, it is possible to stop the mechanical device when the mat switch device is stepped on to ensure safety. .

Next, the operation of the operation preparation circuit 50 shown in FIG. 5 will be described. First, when operating the mechanical device M, the start switch 53 is pressed. At this time, both the emergency stop button 51 and the contact 52 are turned on, and the switch 55 is also turned on. Therefore, when the start switch 53 is pressed, a current flows through the coil L3 of the relay CRIM, and the relay contacts P3 and P4 are turned on. This relay contact P3, P4
Turning on turns on the machine M, and thereafter, even if the starting switch 53 is turned off, the current continues to flow in the coil L3 by turning on the relay contact P3. When the mat switch device is stepped on in this state, the switch 55 is turned off, so that the coil L3 of the relay CRIM is de-energized and the contacts P3 and P4 are turned off. If so, stop.

FIG. 6 is an example in which the mat switches MS2 _{1 to} MS2 _n of FIG. 3 are individually wired to the control panel and have individual lamp display functions. In the figure, CRKL (K is 1 to n) and CR55 are Indicates relay coil, LPK indicates lamp, CRKP indicates relay coil C
It shows the contacts that turn on when the RKL is energized. Further, the same circuit as that described in FIG. 5 is used for the operation preparation circuit 50.

In this mat switch device is a mat switch MS2 _K
When is stepped on, the relay coil CRKL of that system is energized,
Since the contact CRKP turns on, the relay coil CR55 is energized. When the relay coil CR55 is energized, the switch 55 is turned off, so that the mechanical device M is stopped.

[Problems to be solved by the device]

However, when arranging multiple mat switches, wiring work is easy when connected to a series, but in the case of mat switch failure, each terminal can be checked using a meter (tester) etc. to check which one is malfunctioning. It is necessary to check the continuity of the functions, which makes it difficult to determine. Therefore, a device such as Japanese Utility Model Laid-Open No. 59-55833 is also proposed,
Each mat is complicated and mounting cost is high. Further, as shown in FIG. 6, in the method of individually connecting the wiring to the control panel and providing the confirmation lamp, it takes a lot of time to install the switchboard and an extra lamp display circuit is required, resulting in an increase in cost and equipment control device. There is a problem in that the control circuit on the side differs depending on whether a single mat or plural mats are installed, and the reliability of the circuit is lacking.

The present invention is a mat switch device that secures work safety by using a plurality of mat switches, and it is possible to connect any number of mat switches if the number of connected mats is less than or equal to the maximum number of mat switches. It is an object of the present invention to provide a mat switch device capable of individually judging the off state and checking the broken or short circuit state of each mat switch.

[Means for Solving the Problems]

The air-fuel ratio control device for an internal combustion engine of the present invention which achieves the above-mentioned object is connected to an operation preparation circuit for controlling the start and stop of a mechanical device such as a processing machine, and the operation preparation is performed when the apparatus is placed on the floor and stepped on. A mat switch device for stopping or not starting the mechanical device via a circuit, the mat switch device comprising a control circuit connected to the operation preparation circuit, and one or two sets of the control circuit. , And each mat switch has a plurality of normally open switches between an upper plate and a lower plate, and the fully open switch when the upper plate is stepped on. At least one of them is turned on to short-circuit the one or two sets of terminals, and the control circuit has a plurality of sets of connection terminals to which a plurality of mat switches can be connected, and an output terminal.
A power source, each of the connection terminals is connected to a first electric switching means that is in an ON state when the one or two sets of terminals of the mat switch are not short-circuited, and the output terminal is provided with the electric switch. A second electrical switching means is connected which is short-circuited when the switching means is in an on state and which is opened when at least one of the electrical switching means is in an off state.

[Action]

According to the mat switch device of the present invention, when the plurality of mat switches connected to the control circuit are not stepped on, the circuit connected to each mat switch via the mat switch is energized and provided in this circuit. Each electronic switch is on. Each electronic switch is connected to a power supply in series with a relay coil, and when all the electronic switches are on, the relay coil is also energized and the output terminal of the control circuit is in a short-circuited state. 1 of the mat switch in this state
When one is stepped on, the circuit connected to the mat switch is de-energized and the electronic switch for that circuit is turned off. As a result, the relay coil is de-energized and the output terminals of the control circuit are opened. Then, if the mechanical device is in a non-startable state or is being started by opening the output terminals, the mechanical device is stopped.

〔Example〕

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

FIG. 1 is a circuit diagram showing the configuration of an embodiment of the mat switch device of the present invention, and the conventional members will be described by giving the same reference numerals to the same members. In FIG. 1, MS4 _{1 to} MS4 _n are 4
A terminal type mat switch, 10 is a control circuit, 50 is an operation preparation circuit, and M is a mechanical device.

Each of the 4-terminal type mat switches MS4 _{1 to} MS4 _n is connected in parallel with a plurality of switches that turn on when stepped on.
It is connected to two terminals A, B, C and D. Then, the terminal A ₁ to A _n of each mat switch MS4 ₁ ~MS4 _n is connected to the connection terminal a ₁ ~a _n of the control circuit 10, the terminal B ₁ .about.B _n connection terminals b ₁ ~b control circuit 10 is connected to _n, the terminal C ₁ -C _n is connected to the connection terminal c ₁ to c _n of the control circuit 10, the terminal D ₁ to D _n are connected to the connection terminal d ₁ to d _n of the control circuit 10 .

In this embodiment, the connection terminals a _{1 to} a _n of the control circuit are resistors R _{1 to} R _n.
Is connected to a power source V ₍₊₎ via a connection terminal b ₁ ~b _n is grounded internally, each light-emitting diodes LED ₁ ~ between connecting terminals c ₁ to c _n and the connection terminal d ₁ to d _n LED _n and phototransistor
The light emitting diode units T _{1 to} T _n are respectively connected in series. The transistor parts of the phototransistors T _{1 to} T _n are connected in series and are connected to the positive and negative terminals of the DC power supply 11. Furthermore, the coil L10 of the relay CR10 is incorporated in series circuit phototransistor T ₁ through T _n are connected in series. Both ends of the contact P10 of the relay CR10 are connected to the output terminals e and f of the control circuit 10. In addition,
In this embodiment, the DC power source of the control circuit 10 is produced by rectifying the AC power source 1 after voltage conversion.

The configuration of the operation preparation circuit 50 is the same as the conventional one, and in the figure, 51 is an emergency stop button, 52 is a contact point called a safety plug provided on a door of a protective wall provided around the machine M, and 53 is The start button 54 is a switch that is turned off during automatic operation. In this embodiment, the relay CR10 is connected to the normally closed switch 55 which is turned off when the mat switch is stepped on in FIG. CRIM is a relay, L3 is a relay coil, and P3 and P4 are relay contacts. By connecting the output terminals e and f of the control circuit 10 to the operation preparation circuit 50, it is possible to stop the mechanical device when any _{one of} the mat switches MS4 _{1 to} MS4 _n connected to the control circuit 10 is stepped on for safety. Can be secured.

Next, the operation of the mat switch device of the present invention constructed as above will be described.

(1) State where the mat switch is not stepped on In this state, all the switches incorporated in all the mat switches MS4 _{1 to} MS4 _n are off. Therefore, to explain the circuit which connects the mat switch MS 4 ₁ as a representative, the terminal A ₁ of the power source V ₍₊₎ current from the resistor R ₁ → mat switch MS 4 _1, C ₁ → the light emitting diode LED ₁ → phototransistor
T ₁ → Flows with mat switch MS4 ₁ terminals D ₁ and B ₁ . As a result, the light emitting diode LED ₁ emits light and the phototransistor
T ₁ turns on. Thus, all phototransistors
Since T _{1 to} T _n are on, the coil L10 of the relay CR10 is also energized, the contact P10 remains on, and the output terminal of the control circuit 10 is in a short circuit state.

Therefore, in this state, a current flows through the coil L3 of the relay CRIM of the operation preparation circuit 50, the relay contacts P3 and P4 are in the ON state, and the mechanical device M is in the operable state.

(2) State where the mat switch is stepped on In this state, at least one of the mat switches MS4 _{1 to} MS4 _n is
Since one is stepped on, one of the switches built in the stepped mat switch is turned on. For example, if the mat switch MS41 is stepped on, _{one of the} switches incorporated therein is turned on. Then, the terminals A ₁ and B _{1 of} the mat switch MS4 ₁ are short-circuited, and the current flows from the power supply V ₍₊₎ to the resistance R ₁
→ terminal A ₁ of the mat switch MS 4 _1, no current flows through the mat switch MS 4 ₁ terminal B ₁ and photo transistors T _1, the light emitting diode LED ₁ is turned off, the photo transistors T ₁ is turned off. As a result, the coil L10 of the relay CR10 is de-energized, the contact P10 is turned off, and the output terminals of the control circuit 10 are opened.

Therefore, no current flows through the coil L3 of the relay CRIM of the operation preparation circuit 50, and the relay contacts P3 and P4 are turned off. This relay contact P
If the mechanical device M is in a non-startable state or is in operation due to the turning off of 3 and P4, it stops.

The contacts of the control circuit 10 that do not connect the mat switch
a _K , b _K , c _K , d _K , (K is 1 to n), between contacts a _K- c _K ,
By short-circuiting the contacts b _K -d _K with a jumper wire or the like, it is possible to connect a desired number of mat switches to the control circuit 10. Furthermore, regarding the disconnection or short circuit of the wiring between the mat switches and the short circuit of the circuit inside the mat switch, the light emitting diode turns off regardless of any failure, so the failure location can be easily determined and the phototransistor is also turned off. Therefore, it is safe because the mechanical device stops.

[Effect of device]

As described above, the mat switch device of the present invention has the following effects.

(1) The investigation time when the mat switch fails can be shortened,
There is no need for measuring instruments.

(2) Since a single mat switch or a plurality of mat switches can be connected to the control circuit, only one standard circuit is required for the equipment control device side, and wiring cost, control cost, and space are saved.

(3) When the mat switch fails, the mechanical system stops even when the wiring system breaks or a short circuit occurs, and it operates on the safe side.

[Brief description of drawings]

FIG. 1 is a circuit diagram of an embodiment of the mat switch device of the present invention, FIG. 2 is an explanatory diagram of a conventional mat switch device, and FIG. 3 is a configuration diagram of a mat switch device using a conventional two-terminal type mat switch device. FIG. 4 is a block diagram of a mat switch device using a conventional 4-terminal type mat switch, FIG. 5 is a block diagram of a conventional operation preparation circuit, and FIG. 6 is a mat using a conventional 2-terminal type mat switch. It is a block diagram of another example of a switch device. 10 ... Control circuit, 11 ... DC power supply, 50 ... Operation preparation circuit, CR1
0, CR1M… Relay, LED _{1 to} LED _n … Light emitting diode, MS4 ₁ to
MS4 _n … Mat switch, M… Mechanical device, T _{1 to} T _n … Phototransistor.

 ─────────────────────────────────────────────────── ─── Continuation of the front page (56) Reference JP-A-59-214999 (JP, A) Actual development S55-38510 (JP, U) JP-B 57-4729 (JP, B1)

Claims (1)

[Scope of utility model registration request] 1. A driving preparatory circuit for controlling the start and stop of a mechanical device such as a processing machine, which stops the mechanical device via the preparatory circuit when placed on the floor and stepped on.
Alternatively, the mat switch device is in a non-startable state, and the mat switch device includes a control circuit connected to the operation preparation circuit and a plurality of mat switches connected to the control circuit by one or two terminals. Each of the mat switches has a plurality of normally open switches between an upper plate and a lower plate, and when the upper plate is stepped on, at least one of the normally open switches is turned on to set the one set. Alternatively, the control circuit is configured to short-circuit two sets of terminals, and the control circuit includes a plurality of sets of connection terminals to which the plurality of mat switches can be connected, an output terminal, and a power supply, and each of the connection terminals has the above-mentioned configuration. The one or two sets of mat switches
A first electric switching means which is in an ON state when the terminals of the set are not short-circuited is connected, and the output terminal is short-circuited when the electric switching means is in an ON state, and at least one of the electric switching means is connected. A mat switch device, to which is connected a second electric switching means which is opened when it is turned off.