JPH05337700A - Press operation control method for press equipment - Google Patents

Abstract

PURPOSE:To suspend a press operation when there is the danger of entering a hand into a dangerous area by detecting the direction of a motion of the hand after turn-on operation by a magnetic sensor in the case of executing press operation by a turn-on operation of left and right start switches. CONSTITUTION:In a switch box 10, a magnetic sensor 12 for detecting magnetism of a ring which a worker wears on his finger is provided, and also, plural pieces of the same magnetic sensors 13a-13e are provided in the horizontal direction between the switch box 10 and a dangerous area P, a motion of a hand after a start switch 11 is turned on is grasped from an output variation of these magnetic sensors 12, 13a-13e, and when there is a fear that the hand enters the dangerous area P, a ram is reversed and made to ascend.

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a press operation control method in a press device such as a thermal transfer device, and more particularly to a method for ensuring the safety of an operator during press operation.

[0002]

2. Description of the Related Art As a thermal transfer device for transferring a pattern consisting of a design or characters to the surface of a resin molded product, a transfer plate consisting of a relief plate having the above pattern formed in a predetermined pattern on the surface thereof is attached to a heating platen. , A printing plate (hereinafter,
There is known a hot-stamp type thermal transfer device in which the transfer layer is pressed against a work, and the transfer layer is transferred to the surface of the work according to the above pattern by the press pressure and heat to paint.

The operation of the thermal transfer device is usually performed by turning on a pair of left and right start switches by an operator, but the operation area of the start switches and the press area (that is, a dangerous area) by the heating platen are close to each other. Therefore, since there is a risk that the operator's hand will inadvertently enter under the descending heating plate, as a method of avoiding this danger, conventionally, a transmission type optical sensor for monitoring the dangerous area is provided, When an object such as the hand enters the dangerous area when the start switch is turned on and the pressing operation is started, this is detected by the optical sensor, and the ram is immediately inverted and raised. If you do not press and hold the left and right start switches of the ram until the ram reaches the lower limit, the pressing operation will not be completed, and if either start switch is reached before the lower limit is reached, If the hand of the operator from the ground leaves,
A method of immediately reversing and raising the ram was adopted.

[0004]

However, in the former method using the optical sensor described above, a certain amount of time elapses between the time when the worker starts a dangerous operation and the time when the detection is performed by the optical sensor. It is possible that the danger zone will be completely reached before the reversal rises. On the other hand, in the latter method in which the left and right start switches are continuously pressed, both hands of the operator are restrained at the switch positions, and when the ON operation of any of the start switches is interrupted, the press operation is immediately stopped. It is an effective method to avoid danger,
Since the operator's hand is restricted to the switch position until the ram descends, work time loss occurs, and even if a single time loss is small, that time loss is accumulated, resulting in workability. From the aspect of, the efficiency was supposed to drop considerably.

Therefore, it is an object of the present invention to provide a press operation control method for a press device capable of reliably avoiding a danger during press operation without impairing work efficiency.

[0006]

That is, the present invention is a method of controlling a press operation of a press device in which a press operation is started by simultaneously operating two left and right start switches provided on the front surface of a press area. In the left and right switch operation areas where the start switch is provided, magnetic sensors for detecting magnetic objects attached to the left and right hands of the operator are provided, and similar magnetic sensors are provided in the left and right switch operation areas. A plurality of them are provided side by side in the left-right direction that demarcates the press area, and the movement direction of the left and right hands after operating the start switch is grasped by comparing the changes in the outputs of these magnetic sensors, and the movement direction of the hand is determined. It is characterized in that the pressing operation is interrupted when the pressing area is approaching.

[0007]

According to the above method, the magnetic sensor provided in the switch operation area and the plurality of magnetic sensors arranged side by side in the left-right direction between the switch operation area and the press area to define both areas. Output changes with the movement of the operator's hand, and the direction of the movement of the hand can be grasped from the comparison of these output changes, and there is no risk that the movement direction will rush into the press area. In that case, the press operation is continued, and if there is a risk of a plunge, the press operation is interrupted.

[0008]

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

FIG. 1 shows a hot stamping type thermal transfer device 1, in which a transfer unit 4 which is driven up and down by a ram 3 is provided above a transfer table 2 on which a work W is set. This transfer unit 4 is a heating plate 5
The transfer plate 6 is attached to the lower surface of the heating plate 5, and the unit frame 7 is provided with the film supply means 8 and the film winding means 9.
The transfer film X, which is wound around the film winding means 9 from above, is supplied below the transfer plate 6.

Further, in this thermal transfer device 1, when a start switch (touch switch) described later is turned on, the transfer unit 4 descends, the transfer plate 6 is pressed against the work W via the transfer film X, The transfer pattern formed on the transfer plate 6 is transferred onto the work W by the transfer layer of the transfer film X by the press pressure and heat during the pressing operation, and then the transfer unit 4 is raised to the standby position. Has been done.

In the thermal transfer apparatus 1 described above, switch boxes 1 are provided on the left and right sides of the front surface of the transfer table 2 described above.
0 and 10 are provided, and each switch box 10 and 10 has a start switch (touch switch) as shown in FIG.
A magnetic sensor 11 and a magnetic sensor (hereinafter, referred to as a switch-side magnetic sensor) 12 are provided. Therefore, one start switch 11 and one magnetic sensor 12 are provided on the left and right. In addition, of the upper surface of the transfer table 2, the above-mentioned heating plate 5
2 is a range surrounded by a chain line in FIG. 2, the press area P and the switch boxes 1 on the left and right
A plurality of magnetic sensors (hereinafter, referred to as boundary side magnetic sensors) 13a in the left-right direction, which define them,
13b, 13c, 13d and 13e are provided.

On the other hand, the operator who operates the thermal transfer device 1 is
A magnetic object on both hands, such as a magnetic ring 14,
14 (see FIG. 3), the switch-side magnetic sensors 12 and 12 are mounted on the switch box 10 and 10 by the operator's both hands to turn on the start switches 11 and 11. When placed on
It is configured to detect the magnetism of these rings 14, 14.

Further, the boundary side magnetic sensors 13a to 13a.about.
Similarly, 13e is for detecting the magnetism of the rings 14, 14, and after the ON operation of the start switches 11, 11 described above, the switch side magnetic sensor 12 indicates the direction of movement of the hand of the worker who leaves the switch boxes 10, 10. , 12 are arranged so that the change in the level of each detection output can be grasped. That is, in the case of this embodiment, five boundary side magnetic sensors 13a to 13e are provided, one of them 13c is arranged at an intermediate position between the left and right switch boxes 10, 10, and two 13b and 13d are provided. Two remaining 13 placed near the left and right edges of the dangerous area P
a and 13e are arranged outside the left and right ends.

FIG. 3 shows a control circuit of the thermal transfer apparatus 1, which is provided with a controller 15. The controller 15 is connected to the left and right start switches 11 and 11, and the magnetic sensor output means 16 is provided with a switch side magnetic field. The sensors 12 and 12 are connected to the boundary side magnetic sensors 13a to 13e, and the magnetic sensor output means 16 outputs the magnetic detection outputs of these magnetic sensors 12, 12, 13a to 13e via the sensor output storage means 17. The input is made to the comparison means 18. This sensor output comparison means 18
When the left and right switch-side magnetic sensors 12, 12 output a magnetic detection output of a predetermined level, the controller 15 inputs a signal to the controller 15 indicating that both hands of the operator are placed on the switch boxes 10, 10. Then, the controller 15 in this state is the left and right start switches 11, 11
When an ON signal is input from the same time, the ram drive means 19 is operated to start the press operation.

In addition, the above sensor output comparing means 18
Are the magnetic sensors 12, 12, 13 after the start of the press operation.
a to 13e are compared, and the direction of the movement of the operator's hand is read and input to the controller 15 as described below with reference to Table 1. In the controller 15, when the direction of hand movement is in the direction of approaching the danger area P, an emergency stop signal is output to cause the ram drive means 19 to rapidly reverse and raise the ram 3 to avoid danger.

[0016]

[Table 1] Next, referring to Table 1, a method of grasping the moving direction of the hand will be described. However, Table 1 focuses on the movement of the left hand, and the following description is the same for the movement of the right hand or both hands.

That is, if the operator continues to touch both of the start switches 11 and 11 with the start operation, as in the output state of the first stage in Table 1, the sensor 1
No change occurs in the magnetic detection outputs of 2, 13a and 13b, and the output is small at the central boundary side magnetic sensor 13c because it is far from the ring 14. Therefore, it is determined that there is no hand movement, and the emergency stop signal is not output.

When the left hand moves in the direction of arrow a in FIG. 2 after the start operation, the magnetic detection output of the boundary side magnetic sensor 13a on the side closer to the hand increases as in the second output state. Together with other magnetic sensors 12, 13
The outputs of b and 13c decrease. Then, since the movement in the direction of the arrow a is a direction away from the dangerous area P, when the output state as in the second stage is obtained, there is no danger and the emergency stop signal is not output.

Further, in FIG. 2, when there is a motion of pulling the hand from the switch box 10 as shown by an arrow b, the magnetic sensors 12, 13 are in the output state of the third stage.
The outputs of a, 13b and 13c decrease. And since the movement in the direction of the arrow b is not dangerous, 3
The emergency stop signal is not output in the output state of the second stage.

Further, in FIG. 2, the boundary side magnetic sensor 1
When there is a hand movement in the direction of arrow c or arrow d between 3a and 13b, the output of the switch-side magnetic sensor 12 decreases as shown in the output states of the fourth and fifth stages, The outputs of the boundary side magnetic sensors 13a and 13b increase. In that case, in the movement in the direction of arrow c closer to the boundary side magnetic sensor 13a, the output increase of the sensor 13b is larger in the sensor 13a, and conversely in the movement in the direction of arrow d closer to the boundary side sensor 13b. Sensor 13a
The output increase amount of is smaller than that of the sensor 13b. Comparing the movement in the direction of arrow c and the movement in the direction of arrow d, the latter is a movement that may not enter the dangerous area P, but the latter may enter the dangerous area P. Therefore, comparing the sizes of the increased outputs of the boundary side sensors 13a and 13b, the emergency stop signal is not output in the former case because there is no risk, and in the latter case, the press operation is interrupted.

Further, in the movement of the hand in the direction of the arrow e or the direction of the arrow f in FIG. 2, the output states of the sixth and seventh steps are obtained, the outputs of the magnetic sensors 12 and 13a are reduced, and the central boundary side is obtained. The output of the magnetic sensor 13c rapidly increases. Since movements in these directions are all likely to cause the hand to enter the dangerous area P, in these cases, an emergency stop signal is output to interrupt the press operation.

Next, the control of the press operation will be described with reference to the flowchart of FIG.

In step S1 of FIG. 4, when the operator places his or her hand on the switch boxes 10 and 10, the switch side magnetic sensors 12 and 12 detect the magnetism of the rings 14 and 14, and this is the magnetic sensor output means 16. , The sensor output storage means 17, and the sensor output comparison means 18 to be sent to the controller 15. When the start switches 11 and 11 are touched from this state, a start signal is input to the controller 15 in step S2, the controller 15 operates the ram drive means 19, and step S3
Press to start the press operation.

From the start of the above press operation until the ram 3 reaches the lower limit and the thermal transfer operation is completed, step S
4, it is checked whether or not each magnetic sensor 12, 13a to 13e has an output change, and when there is no output change,
That is, when both hands are left on the switch boxes 10 and 10, the pressing operation is completed and step S
At step 5, the ram 3 is reversed and raised to end the processing.

However, when there is a change in the output, in step S6, the direction of the hand movement is checked as described in Table 1, and it is determined whether or not there is a risk of the hand entering the dangerous area P. Only when there is a risk, the emergency stop signal is output in step S7, the ram 3 in the middle of descending is reversed and raised, and the press operation is interrupted.

Therefore, even if the control structure is such that the pressing operation is not completed unless the start switches 11 and 11 are continuously touched until the ram 3 reaches the lower limit, the dangerous area P
It is possible to avoid the danger of the operator's hand rushing in to the operator. Therefore, after touching the start switches 11 and 11, the operator immediately releases his or her hands from the start switches 11 and 11 to perform another work (for example, the next work W Since it is possible to move to preparation, work efficiency will be improved.

Furthermore, the rings 14 and 1 worn by the worker
The magnetism of No. 4 is detected by a plurality of magnetic sensors 12, 13a to 13e, and each sensor 12, 1 when the hand moves
Since the ram 3 is controlled by grasping the direction of movement from the output changes of 3a to 13e, excellent responsiveness and reliable risk avoidance can be achieved.

As the magnetic sensor used in the present invention, in addition to a magnetoresistive element and a Hall element, for example, Japanese Patent Laid-Open Publication No.
-308982, or JP-A-2-162276
It is conceivable to use the high-sensitivity magnetic sensor disclosed in the publication.

In the above embodiment, the thermal transfer device was explained as an example of the pressing device, but the present invention is not limited to this device but can be widely applied to the pressing device, and the number and arrangement of the magnetic sensors used are also the same as those in the above embodiment. The structure is not limited, and any structure may be used as long as the direction of movement of the hand can be grasped by the change in the output of the magnetic sensor used.

[0030]

As is apparent from the above description, according to the present invention, it is possible to avoid a danger due to the operator's hand rushing into the dangerous area without the structure of continuously touching the start switch until the pressing operation is completed. Therefore, the worker can immediately move to another work after the touch, and the work efficiency is improved accordingly.

Further, a magnetic object attached to the operator's hand is detected by a plurality of magnetic sensors, and the movement direction is grasped from the output change of each sensor when the hand is moved to control the press operation. Therefore, the responsiveness is excellent and it is possible to surely avoid the danger.

[Brief description of drawings]

FIG. 1 is a front view of a thermal transfer device to which the method of the present invention is applied.

FIG. 2 is a plan view of a transfer table in the thermal transfer device.

FIG. 3 is a control circuit diagram of the thermal transfer device.

FIG. 4 is a flowchart of control operation.

[Explanation of symbols]

 1 Thermal Transfer Device 10 Switch Box 11 Start Switch 12 Switch Side Magnetic Sensors 13a-13e Boundary Side Magnetic Sensor 14 Ring P Dangerous Area

Claims (1)

[Claims] 1. A press operation control method for a press device in which a press operation is started by simultaneously operating two left and right start switches provided on the front surface of a press area, wherein the start switch is provided. In the left and right switch operation areas, magnetic sensors for detecting magnetic objects attached to the left and right hands of the worker are respectively provided, and similar magnetic sensors are provided in the left and right directions separating the left and right switch operation areas from the press area. When a plurality of side-by-side hands are moved after operating the start switch, the direction of movement is grasped by comparing the changes in the outputs of these magnetic sensors. Operation control method for a press device, characterized in that the press operation is interrupted when it is close to the vehicle.