JPH0523897A - Safety device - Google Patents

Abstract

PURPOSE:To provide a device that does not necessarily require a detector by which a part of a worker's body is detected if it is in a danger zone at a critical timing nor a emergency shutdown device by which a device is suddenly stopped based on the detected signal of such detector, but still prevents the deterioration of workability caused by restricting the part of the worker's body. CONSTITUTION:This safety device is used for a press which possibly presents a danger for the worker to injure his hands if the hands are in a contact zone between an upper mold and a lower mold, namely in a danger zone at the critical timing when the upper mold and the lower mold are brought into pressurized contact with each other. By utilizing an input terminal 17 to which a voltage from a power source 11 is inputted and the voltage inputted to the input terminal 17, the device contains an electrical conductor string 7 by which an electrical shock is given to the worker's hands just before the critical timing if the worker's hands are in the danger zone.

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a safety device for use in a device such as a press machine, a cutter, a shirring machine, a roll machine, a press machine, a belt, etc., which is likely to damage the body of an operator. More specifically, the present invention relates to a safety device used for a device that may damage the body of the worker at a predetermined dangerous timing when a part of the body of the worker exists within a predetermined dangerous area.

[0002]

2. Description of the Related Art Conventionally, in the case of a press machine as an example of a device that may damage an operator's body, when an operator places an iron plate to be punched on a mold by hand and depresses a pedal, a one-turn clutch is provided. When the punching die descends from above and the iron plate is lowered to the punching lowest point, the punching die automatically rises and stops when it reaches the first stop position. The operator removes the iron plate or product remaining on the mold, and then inserts the iron plate to be punched. This work is repeated all day long, but when the worker is tired, this work rhythm is reflexively broken, and the punching die descends before the end of the hand escape to cut or strike the fingertip. There have been many crushing accidents. In addition, even in the case of so-called double striking due to a failure of the one-turn clutch, there is a risk that the worker's body is damaged as described above. Such dangers are not limited to press machines, but include cutters, shears, rolls, press machines, belts,
Applies to all other devices with moving objects.

As a safety device used in a press machine as an example of a device having a risk of damaging the body, there have been the following devices generally known in the past.

There is a so-called photoelectric safety device as described in JP-A-61-52496. In this photoelectric safety device, when a worker's hand enters the danger area at a dangerous time, the light beam emitted from the projector is blocked by the worker's hand and the light is received. It stops reaching the die, and the interruption of the luminous flux is detected to suddenly stop the punching die from descending. In the case of this photoelectric safety device, it does not work effectively against so-called double striking due to a failure of the emergency stop device or a failure of the one-turn clutch,
Further, when machining a punching die or a bending die having a complicated shape, there is a drawback that the light beam may not be able to pass through to an optimum position. Further, there are drawbacks that it is necessary to change the mounting position of the projector every time the mold is replaced and a high-performance clutch is required.

As another example of the safety device, Japanese Patent Laid-Open No. 63-
There was a so-called mechanical arm pullback system as described in Japanese Patent No. 149100. This mechanical arm pull-back type safety device puts gloves or bracelets on both arms (or one arm) of the worker, attaches rope to it, and when the punching die drops to a dangerous position, the rope is pulled and the arm of the worker is pulled. It is to pull back outside the danger area. This mechanical arm pull-back type safety device has the advantage that the structure is simple and inexpensive, but since the worker's arm etc. is restrained to some extent by ropes, etc. There was a drawback that it was difficult to perform work with high efficiency.

Still another safety device is disclosed in Japanese Patent Laid-Open No. Sho 64
There was a so-called impedance measuring type safety device as described in Japanese Patent No. 27800. In the case of this safety device of the impedance measuring system, it is difficult to incorporate it into the device, the device becomes complicated, and an emergency stop device is required, which is expensive.

[0007]

As described above,
Conventional safety devices, such as photoelectric or impedance measurement type safety devices, detect the presence of a part of the operator's body in the dangerous area at the time of dangerous time, and immediately detect the detected device. In the case of a safety device that stops, it is inevitable that it is difficult to accurately detect the presence of a part of the worker's body in the dangerous area at dangerous timing, and if it is not detected accurately, it will be an expensive detection. In addition to the need for a device, a device for sudden stop after detection is also indispensable, so that the entire device has a drawback of being expensive. On the other hand, there is a so-called mechanical arm pull-back type safety device that can solve such a drawback, and when a part of the worker's body exists in the dangerous area, it is forcibly forced immediately before the dangerous timing. By pulling a part of the worker's body with a rope etc., it is not necessary to detect that a part of the worker's body is in the danger area at a dangerous time, and it is necessary to stop the device suddenly based on the detection. However, there is a new drawback that the workability is deteriorated due to a part of the body of the worker being restrained by a rope or the like. As described above, in the conventional safety device, the detection device that detects the presence of a part of the worker's body in the dangerous area and the sudden stop device that performs the sudden stop of the device based on the detection output of the detection device are provided. There is a trade-off between the technical requirement to eliminate the need for the operator and the technical requirement to improve the workability by releasing the restraint of the operator's body. The device has never existed.

In view of the above situation, an object of the present invention is to detect the presence of a part of the operator's body in a dangerous area at a dangerous timing and to stop the device suddenly based on the detection of the detecting device. It is an object of the present invention to provide a safety device that can satisfy both of a request for eliminating the need for a sudden stop device and a technical request for improving the workability by releasing the restraint of an operator.

[0009]

According to the present invention as set forth in claim 1, when a part of a worker's body is present within a predetermined dangerous area, the worker's body is damaged at a predetermined dangerous timing. A safety device used for a device with a risk of affecting, a voltage input section to which a voltage from a predetermined power source is input,
An electric shock means for applying an electric shock to a part of the operator's body existing in the danger area immediately before the danger timing by using the voltage input to the voltage input unit. .

According to a second aspect of the present invention, the electric shock means according to the first aspect uses the voltage input from the voltage input section to apply a predetermined voltage to the body of the worker.
A conductive member connected to ground is provided, and electric shock due to discharge from the worker's body is caused by bringing the conductive member into contact with a part of the worker's body existing in the dangerous area immediately before the dangerous timing. Characterized by giving.

[0011]

According to the present invention as set forth in claim 1, when a part of the worker's body is present in the danger area, the worker's body is damaged immediately before the danger timing of the worker's body damage. Since an electric shock is applied to a part of the body, a part of the body of the worker is instantaneously retracted rearward, and a part of the body of the worker is instantaneously retracted from the dangerous area.

According to the present invention described in claim 2, in addition to the function of the invention described in claim 1, as a method of giving an electric shock, a voltage is applied to the worker's body, and a conductive material connected to ground is used. When the member comes into contact with a part of the worker's body existing in the dangerous area immediately before the dangerous timing, the voltage applied to the worker flows to the ground through the conductive member, and the worker is electrocuted. Can be given. as a result,
The conductive member for giving an electric shock to the worker only needs to be connected to the ground, and the conductive member is attached in a state of being in contact with a part of the device such as the press machine made of the conductive material such as metal. Only that is enough.

[0013]

Embodiments of the present invention will now be described with reference to the drawings.

FIG. 1 shows a press machine as an example of an apparatus which may damage a part of the body of an operator. Press machine 1
Is provided with a ram 2 that moves up and down, and an upper die 3 is attached to the ram 2. Reference numeral 4 in the drawing denotes a lower die, and the ram 2 descends to press the workpiece 10 by the upper die 3 and the lower die 4. A magnet 5 is provided at a predetermined position of the ram 2, and a reed switch 6 that is turned on by the magnet 5 when the ram 2 descends is built in the press machine 1. Reference numeral 7 in the drawing is a flexible string-shaped conductor which is an example of a conductive member, and a voltage is applied when the reed switch 6 is turned on. 5 in the figure
Reference numeral 5 denotes a moving member integrally attached to the ram 2. The moving member 5 moves up and down as the ram 2 moves up and down, and when the ram 2 reaches its stroke end, the upper limit ON switch 50 is turned ON, and the ram 2 moves. The lower limit OFF switch 51 is turned off when the stroke reaches the stroke end. Reference numeral 8 denotes a high-voltage conductive mat which has a magnet attached to the lower surface and is grounded in an upright posture by the attracting and fixing action of the magnet, and is not normally provided.

FIG. 2 is a circuit diagram showing a control circuit of the safety device according to the present invention. In the figure, 11 is an AC power supply, and the voltage from this AC power supply 11 is input to an input terminal 17 which is an example of a voltage input section. Reference numeral 12 in the drawing denotes a manual switch, which is configured to be manually turned on and off by an operator. By turning on the manual switch 12, the safety device is turned on. In the figure, F is a fuse and 13 is a leakage transformer. This leakage transformer 13 supplies the voltage from the AC power source 11 to 10
It is a transformer that boosts voltage to KV, but is limited to a weak current of about 3 mA even if it is short-circuited. Further, the limiting high resistance R is for making a high-voltage electric shock current a weak current of 0.5 mA or less at maximum and applying it to the string-shaped conductor 7. Reference numeral 14 in the figure is a slidac, and the voltage applied to the string-shaped conductor 7 can be adjusted in the range of 5 to 10 KV by adjusting the slidac 14, and it can be adjusted to a desired value depending on the case of bare hands and wearing of gloves. It is configured so that you can select a value. Then, when the ram 2 shown in FIG. 1 rises to its stroke end, the upper limit ON switch 50 is switched to ON, and the current passes through the upper limit ON switch 50, the lower limit OFF switch 51, and the detection circuit 16 to drive the coil of the electromagnetic relay 15. Since it flows, the electromagnetic relay 15 is switched on. Next, when the ram 2 descends, the upper limit ON switch 50 is switched to OFF, and when the reed switch 6 is subsequently turned ON by the magnet 5, a current is applied to the string-shaped conductor 7.

The operator's hand exists in a dangerous area where the operator's hand is sandwiched between the upper mold 3 and the lower mold 4, and the upper mold 3 and the lower mold 4 allow the operator's hand to move. The string-shaped conductor 7 is configured to come into contact with the operator's hand just before the timing when the hand is caught, that is, the dangerous timing (see FIG. 1). If the operator's hand touches the string-shaped conductor 7,
A maximum current of 5 to 10 KV and a current of about 0.5 mA flows into the hand of the worker and can give an electric shock to the worker. When the voltage flows from the cord-shaped conductor 7 into the operator's hand, the momentary detection circuit 16 is activated to cut off the current in the coil of the electromagnetic relay 15, and the electromagnetic relay 15 is turned off to change the voltage to the cord-shaped conductor 7. Is controlled to be stopped. It takes about 1/10 second until the electromagnetic relay 15 is turned off by the current flowing into the operator's hand. Regarding the danger at the time of electric shock to the body, it is generally accepted in the world that when a current of 30 mA flows for 1 second or more in the heart, it enters the danger area.
In this device, the maximum current flowing into the worker is 0.5.
mA, and the electric shock time is within 1/10 seconds,
The ratio is only 0.5 mA / 30 m × 1 second / 10 = 1/600, which is very safe. In the figure, reference numeral 52 is a voltage check switch, and when the operator turns the voltage check switch 52 on, a current flows through the voltmeter 53 so that the voltage can be checked.

FIG. 3 is a circuit diagram showing another embodiment. 2 is different from that shown in FIG. 2 in that both the secondary electrodes of the leakage transformer 13 are connected to the string-shaped conductor 7, and a + voltage is applied to each of the electric wires 150 protruding from the insulator. That is-and-the one to which the voltage is applied coexist. In this case, an electric shock can be applied even when the worker is using the insulating shoes.

FIG. 4 is a circuit diagram showing still another embodiment.
Is. As shown in Fig. 4, apply an electric potential to the worker's body.
And one electrode of high voltage. Also, is it a string-shaped conductor 7 or the like?
Connect the conductive member consisting of
Use as an electrode. However, in this case, the worker should wear insulating shoes.
Work on a sunken or insulated workbench 90
There is a need. This workbench 90 has insulating material 91 such as insulators
It is installed and keeps insulation against the floor 93
It is configured as Work on this workbench 90
For the traders, conductive shoes or high-voltage applying means or
Semi-conductive (10 ⁶-10⁸Ω) Safety shoes 92
This makes it easy to apply a high potential to the worker, and
Good workability. The semi-conductive safety shoes 92, etc. are
The electrical resistance of is not limited to the above, but in short
High resistance that can be applied to the worker's arm, etc.
If In addition, as shown by the broken line in the figure,
Configured to apply voltage directly to parts of the body such as arms and hands
You may. In this case, the worker must wear insulating shoes.
It Further, in the case of another embodiment shown in FIG.
Is a glove whose back side has conductivity and palm side has insulation.
Wearing and working is preferred. Wear such gloves
If it is used, even if the worker touches the work target 10,
The string-shaped conductor 7 that has been hit from the top without being hit
(See Fig. 1) touches the back of the worker's glove.
Will give you an electric shock. In addition, in this FIG.
In the case of another embodiment shown, a high voltage conductive mat 8 (see FIG.
1) is unnecessary. In the case of another embodiment shown in FIG.
A string-shaped conductor 7 which is an example of a conductive member.
All that is required is to continue, such as electric wires for applying voltage.
Since it is not necessary to connect it, the string-shaped conductor 7 can be used as a magnet or string.
Installed in a state of contacting the metal part of the press machine 1 etc.
There is an advantage that the simple mounting method that it is necessary. Well
In addition, the string-shaped conductor 7 attached to the press 1 unexpectedly becomes gold.
No short circuit occurs even if it contacts the metal part.

In each of the embodiments described above, the AC power source 11 is used as a power source, but a DC power source may be used instead. Further, although the magnet 5 and the reed switch 6 which is ON / OFF controlled by the magnet 5 are used, a slide type contact switch or a non-contact non-contact switch may be used instead. Furthermore, the control circuit 1
Instead of 6 and the electromagnetic relay 15, a timer or a transistor circuit may be used so that the electric shock time can be freely set. Further, in the case of the embodiment shown in FIGS. 1 to 3, in order to ensure electric shock, the body may be grounded or grounded with a high resistance of 1 to 10 MΩ. Further, instead of the leakage transformer 13, a high frequency oscillation type high voltage generator may be used. In addition,
In the case of the embodiment shown in FIG. 3, instead of mounting the string-shaped conductor 7 on the upper mold 3, that is, on the moving object side, a mat having a long conductive foot upward on the lower mold 4 side immediately before the dangerous timing. Alternatively, a ribbon or a high voltage conductive mat 8 (see FIG. 1) may be attached to apply a predetermined voltage to give an electric shock to an operator's hand. The string-shaped conductor 7 may be composed of an electric wire, a chain, or the like, or may be composed of a semiconductor.

In the present embodiment, the press machine 1 is shown as a device that has a risk of damaging the body of an operator, but the present invention is not limited to this, and for example, a cutter, shearing, roll, pressing machine, belt, All other devices that may damage the body of the worker's hands, fingers, arms, legs, etc. due to moving objects are targeted.

[0021]

According to the first aspect of the present invention, when a part of the worker's body is present in the dangerous area, an electric shock is applied immediately before the dangerous timing to reflexively affect the worker's body. Since it is possible to evacuate a part from the dangerous area, a detection device that detects whether or not a part of the operator's body is present in the dangerous area and an emergency stop that stops the device based on the detection signal of the detection device. Since it is not always necessary to provide a stop device or the like and a part of the worker's body is not restrained by a rope or the like, it is possible to provide a safety device having good workability and capable of performing highly efficient work. I arrived.

In addition to the effect of the invention as set forth in claim 1, the present invention as set forth in claim 2 connects an electric wire for supplying a voltage to the conductive member as long as the conductive member is simply connected to ground. Since it is not necessary to install the conductive member in contact with the device part having conductivity such as iron, it is sufficient, and the conductive member is unexpectedly used for other conductive parts such as working devices. Even if it comes into contact with, there is no short circuit.

[Brief description of drawings]

FIG. 1 is a use state explanatory view showing a state in which a safety device according to the present invention is used in a press machine.

FIG. 2 is a circuit diagram showing a control circuit of the safety device according to the present invention.

FIG. 3 is a circuit diagram showing a control circuit of another example of the safety device according to the present invention.

FIG. 4 is a circuit diagram showing a control circuit of still another example of the safety device according to the present invention.

[Explanation of symbols]

1 Press machine 3 Upper mold 4 Lower mold 5 magnets 6 reed switch 7 String-shaped conductor 11 AC power supply 17 input terminals 15 Electromagnetic relay 14 Slideac 2 Ram 8 High voltage conductive mat 10 Object to be processed F fuse 50 upper limit ON switch 51 Lower limit OFF switch 52 Voltage check switch 53 Voltmeter R control high resistance 16 Detection circuit 90 conductive workbench 91 Insulating material 92 safety shoes

Claims (2)

[Claims] 1. A safety device for use in a device having a risk of damaging a worker's body at a predetermined dangerous timing when a part of the worker's body is present within a predetermined dangerous area. A voltage input unit to which a voltage from a predetermined power source is input, and a voltage input to the voltage input unit are used to display a part of the operator's body in the danger area immediately before the danger timing. A safety device comprising: an electric shock means for giving an electric shock to the user. 2. The electric shock means according to claim 1, comprising means for applying a predetermined voltage to the body of the worker by using the voltage input from the voltage input section, and a conductive member connected to the ground. A safety device comprising: including a part of the body of the worker existing in the dangerous area immediately before the dangerous timing, the electric conductive member being in contact with the conductive member, thereby giving an electric shock due to discharge from the body of the worker. .