JP3093671B2 - Beam safety device - Google Patents

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION The present invention relates to a method for forming a plurality of layers of light beams from the outside to the inside around a processing machine.
When at least one layer is cut off, the operation of the processing machine is stopped, and furthermore, the light beam of the plurality of layers is cut off or the order of its elimination is determined to determine the working process. The present invention relates to a light beam type safety device.

[0002]

2. Description of the Related Art The applicant of the present invention has disclosed in Japanese Patent Application Laid-Open No. 3-140983 that a plurality of light beams, that is, a plurality of light curtains are formed from the outside to the inside of a press machine, and the light beams of the plurality of layers are formed. A stop signal generating circuit for receiving a cutoff signal and generating a stop signal for stopping the operation of the press machine when at least one layer is cut off, and a light cutoff signal for an innermost light beam to an outermost light beam. A foreign object escape signal generation circuit that detects the disappearance in order and generates a foreign object escape signal, and a stop release signal generation circuit that detects the generation of the foreign object escape signal after the generation of the stop signal and generates a stop release signal A light beam safety device equipped with the following was proposed.

[0003] In this way, it is possible to avoid a detection error of foreign matter intrusion due to a failure of one of the light beams, and to determine the order of blocking and eliminating the light beams of a plurality of layers, so that an operator can enter the inside of the light beam. It is also possible to prevent the danger of apparent recovery from the abnormality, and to improve the monitoring performance.

[0004]

On the other hand, if an apparatus for judging intrusion and escape of a worker's hand or the like by judging such an interruption and the order of dissolution thereof is constituted, in principle, the two times are required. By making the processing machine operable in each ingress / egress process, work safety is further enhanced, and the press machine or the like can be automatically operated.

[0005] However, in practice, irregular operations of the operator or unexpected light interruption occur, so that a problem remains if the work process is determined only by the interruption of the layered light or the direction of eliminating it.

SUMMARY OF THE INVENTION In view of the foregoing, it is an object of the present invention to provide a light beam type safety device using a plurality of layers of light beams, which can reliably detect setting and unloading of a work.

[0007]

In order to achieve this object, according to the present invention, according to claim 1, a plurality of light beams are formed from the outside to the inside around the processing machine, and at least one layer is formed. When cut off, stop the operation of the processing machine,
Further, in the light beam type safety device which determines the work process by judging the order of blocking or eliminating the light beams of the plurality of layers, a work sensor for detecting a work set at the processing position of the processing machine, The work set determining means for detecting that the light from the inner layer to the inner layer is sequentially blocked, and then generating a work detection signal to determine that the work has been set, and that the work set determining means has set the work. In the determined state, the escape determination means for detecting that the blocking of the light rays from the inner layer to the outer layer is sequentially eliminated and determining that the work set portion has escaped, and the escape determination means has detected that the work set portion has escaped. In this state, it was detected that the work detection signal disappeared, and then the interruption of the light beam from the inner layer to the outer layer was sequentially eliminated, and the work removal was completed. Determining, further comprising a work removal determining means for newly enabling the work set determining means, and when the escape determining means determines that the work set portion has escaped, the processing machine is brought into an operable state. I do.

[0008] When the escape determination means detects that the hand of the worker or the work setting portion, which is the work setting mechanism, has escaped, the processing machine is manually operated or automatically operated.
When at least one layer of the light beam is cut off in a state where the processing machine becomes operable according to the determination of the escape determination means, the operation of the processing machine is stopped.

[0009]

DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS A light beam safety device according to an embodiment of the present invention will be described with reference to FIGS. FIG.
Shows a press machine for bending a work 5 of a metal material interposed between the upper mold 2 and the lower mold 3 attached to the slide 1 into a predetermined shape. On one side of the front surface, a projector bracket 10 is attached, light emitting elements 11 are arranged from above to below, and light emitting elements 12 are arranged from an intermediate position on the inside, and two layers of light rays are formed on a vertical surface. Have been. On the other side, the light receiving device brackets 20 are arranged facing each other, and the light receiving device
The light receiving elements 14 and 15 are arranged in the layer. Thus, when any of the layered light beams incident on the plurality of light receiving elements 14 is cut off, a first-layer light cutoff signal L1 is generated from an attached circuit (not shown), as is well known.
Similarly, when any one of the optical axes incident on the light receiving element 15 of the second layer is cut off, a light blocking signal L2 of the second layer is output.

Reference numeral 16 denotes a light irradiator for irradiating the work 5 set on the lower mold 3 with a light beam, and a light receiver 16a is arranged at an opposing position to determine whether or not the light beam is interrupted. A work sensor that detects the presence or absence of the presence of Note that a microswitch or the like may be used as the work sensor in some cases.

FIG. 1 shows these light blocking signals L1 and L2.
And a processing circuit section for the work detection signal w. That is, 30
Is a work process judging means for judging a work process in which the operator takes the work 5 in and out of the press machine. This means is that the outer layer formed by the plurality of light emitting elements 11 and light receiving elements 14 is cut off by the hand of an operator who is a work set part, and the light emitting elements 12 and light receiving elements 15
A work set determining means 31 that detects that the work 5 has been set by detecting that a work detection signal w is output by the work sensors 16 and 16a within a set time, When the work set determining means determines that the work 5 has been set on the lower mold 3, the light blocking of the inner layer is eliminated, and then the light blocking of the outer layer is eliminated within the set time of the associated timer. And escape determination means 32 which determines that the worker's hand has escaped and generates an escape signal a. In a state where the escape determination means determines that the worker's hand has escaped, the light of the outer layer is detected. Is cut off, and then the inner layer is detected to be cut off within the time set by the timer to which it belongs, and it is determined that the work take-out operation has been started. It is detected that the work detection signal w is extinguished within the set time of the timer to which it belongs in the state where it is determined that the outgoing operation has started, and then the light blocking from the inner layer to the outer layer is sequentially eliminated within the set time. It is provided with an unloading completion judging means 34 for judging that the unloading of the work 5 has been completed and further enabling the work set judging means 31 to be newly activated.

The unloading start judging means 33 detects a lowering of the upper die 2 and automatically generates a press operation signal p which is generated.
Makes a decision operation possible. The unloading start judging means and the unloading completion judging means constitute the work unloading judging means of the present invention. In the determination process of each unit described above, if the determination process is not advanced within the set time of the timer to which the unit belongs, the determination operation of the unit is reset and a new determination operation is started. The setting time of the timer is set with a margin for the normal operation speed for each task of the worker, and in any case, is within several seconds. These means can be constituted by various types of hard logic circuits or CPUs which receive the light blocking signals L1, L2 and the work detection signal w.

Reference numeral 21 denotes an OR gate functioning as a stop signal generating circuit, which supplies a stop signal s to a drive control circuit 22 for controlling the operation of the press machine when at least one of the light beam cutoff signals L1 and L2 is inputted. Reference numeral 24 denotes a stop release signal generating means, which generates a stop release signal c in response to the escape signal a, and its generation is reset by the press operation signal p.

Reference numeral 25 denotes a touch switch attached to a wristwatch-type belt to constitute a remote switch for starting operation of the press machine. The touch switch 25 has a transmission circuit 25a for generating, for example, an ultrasonic beam by its operation. A receiving circuit 25b for receiving a transmission beam is attached to the apparatus main body. When the touch switch 25 is operated in the state where the stop release signal c is generated, the transmission signal is received,
A start signal o is supplied to the drive control circuit 22 through the AND gate 26.

The operation of the safety device configured as described above will be described with reference to FIG. Normally, stop release signal generating means 2
No. 4 does not generate the stop release signal c even in a state where the layered light is not blocked, and operates the touch switch 25 so that the press machine does not operate.

As shown in FIG. 2, the work set judging means 31 cuts off the first layer (step S2) from the state where both the light blocking signals L1 and L2 are absent and the work detection signal w is absent (step S1). Next, the second layer is also shut off within the set time (step S3), and subsequently, when the work detection signal w is generated within the set time (step S4), it is determined that the work 5 has been set at the processing position.

The escape judging means 32 determines whether the workpiece 5
Is determined to be set, the interruption of the second layer is canceled (step S5), and then the interruption of the first layer is canceled within the set time (step S6). When it is determined that the hand has escaped, an escape signal a is generated, and in response to this, a stop release signal c is generated. In this state,
By operating the touch switch 25, a start signal o is output through the AND gate 26, and the drive control circuit 2
Reference numeral 2 causes the work 5 to be pressed, and the stop release signal generating means 24 is reset by the press operation signal p to stop the generation of the stop release signal c.

In the state where the stop release signal c is generated, when at least one of the light beam cutoff signals L1 and L2 is generated due to, for example, a hand of the operator, a stop signal s is supplied to the drive control circuit 22, During this time, even if the touch switch 25 is operated, the drive control circuit 22 does not press the work 5.

In the state where it has been determined that the user has escaped as described above, the take-out start determining means 33 further presses the press operation signal p.
Is generated, the first layer is cut off (step S).
7) Then, when the second layer is also shut off within the set time (step S8), it is determined that the removal of the work 5 has been started. In the state where it is determined that the removal has been started, the removal completion determination means 34 first eliminates the work detection signal w within the set time (step S9), and then cancels the interruption of the second layer within the set time. (Step S10), and then the interruption of the first layer is also canceled within the set time (step S10).
11) It is determined that the removal of the work 5 has been completed, and the next determination cycle is started.

As described above, the removal of the workpiece, the subsequent setting of the workpiece, and the escape of the hand can be confirmed by hand.
The safety is further improved, and the operability of the touch switch 25 can be improved without any problem. The blanking is reliably prevented against the principle possible judgment method of automatically operating the press every time the light beam is blocked twice from the inside, and therefore, the automatic beating is possible in response to the escape signal a. Become.

FIGS. 4 and 5 show a beam-type safety device which is particularly effective when the distance between the two layers is increased in order to extend the monitoring range while maintaining the two layers. That is, the work process determining means 4
0 is a 7-step R / S to confirm the 16-step judgment process.
Flip-flops 41 to 47 and a control circuit 51 for performing control such as setting and resetting these flip-flops
To 57. These flip-flops 41 to 47 have light emitting diodes 61 to 67 that are turned on when set outputs Q1 to Q7 are output.

FIG. 5 is a view for explaining the judgment process of the work judging means 40. The symbol "△" indicates an unstable state in which the layered light is blocked or blocked / non-blocked, and an unstable state in which the work detection signal w is present or not. Means □ means an unstable state in which the layered light beam is not blocked or blocked / non-blocked, and an unstable state in which the work detection signal w is absent or not.

The work set determining means is composed of R / S flip-flops 41 and 42 and their control circuits 51 and 52. R / S flip-flop 41 sets output Q
In the state in which the control signal is output from the control circuit 52, when the first layer is cut off or becomes unstable, the control circuit 52 determines that the work process of step S2 has been established, and proceeds to the confirmation state. If the second layer is also cut off or becomes unstable within a predetermined time set by a timer built in 52, the process proceeds to step S3, and if a work detection signal w is also generated or becomes unstable within a predetermined time, the process proceeds to step S3. S4
When the two layers are cut off stably and the work detection signal w is stably generated within a predetermined time, the process proceeds to step S5 to set the R / S flip-flop 42.

In this determination operation, if the work process is not advanced within the set time, the determination process is cleared and the process is restarted from step S2. The presence / absence of the work detection signal w is also determined, and it is also determined whether or not the vehicle is running at a predetermined rhythm, and the determination including the unstable state caused by the operation of the worker is performed. Is determined under high reliability.

The escape determining means comprises R / S flip-flops 43 and 44 and control circuits 53 and 54. In the above-mentioned state, if the second layer becomes non-blocking or unstable due to escape, the process proceeds to step S6, and the R / S flip-flop 43 is set. For this determination, a dedicated flip-flop belongs to reliably detect the start of the workpiece escape and securely hold the information. In this state, if the second layer is reliably turned off within the set time and the first layer is turned off or becomes unstable, the process proceeds to step S7. Further, if the two layers are not stably shut off and the work detection signal w is stably generated within the set time, step S8
Step forward. In this state, the press machine becomes operable. Similarly, if the same state is reached after a set time set by a timer built in the control circuit 54, the process proceeds to step S9, and the R / S flip-flop 44 is set. Then, the escape signal a is generated to make the press machine operable.

The take-out start determining means comprises an R / S flip-flop 45 and a control circuit 55. In the above-described state, if the first layer is turned off or becomes unstable after the generation of the press operation signal p, the process proceeds to step S10, then the first layer is turned off, and the second layer is turned off or becomes unstable. Then, the process proceeds to step S11, and if the two layers are stably cut off and the work detection signal w is stably generated within the set time from that state, the process proceeds to step S12 to perform R / S
The flip-flop 45 is set. This reliably detects that the work 5 has been taken out.

The take-out completion judging means comprises R / S flip-flops 46 and 47 and control circuits 56 and 57. In the state described above, when the work detection signal w disappears or becomes unstable within the set time, the process proceeds to step S13, and further the work detection signal w disappears stably within the set time, and the second layer is cut off or When the state becomes unstable, the process proceeds to step S14, and the R / S flip-flop 46 is set. In this state, if the first layer is cut off or becomes unstable within the set time, the process proceeds to step S15, and R / R
The S flip-flop 47 is set. In this state,
If the first layer is stably shut off within the set time, step S
16, that is, step S1 in the initial state, the R / S flip-flop 41 is set, and the next work set can be determined. In the determination process of step S15,
A dedicated flip-flop 47 is used to reliably detect the state immediately before the work is taken out and hold the information without fail.
Belongs to. The progress of the judgment process can be confirmed by the lighting state of the attached light emitting diodes 61 to 67.

[0028]

According to the first aspect of the present invention, the setting and unloading of the work can be reliably determined by judging the interception of the plurality of layered light beams and the order of elimination thereof and the presence / absence of the work. The operable state can be determined more accurately, and the safety of work is extremely high. Therefore, the manual switch for operating the processing machine can be easily operated, and the operation can be automated if necessary.

According to the second aspect of the present invention, the work take-out judging means detects the light from the outer layer to the inner layer in order, and detects that the work detection signal disappears. Completion of removal is determined. According to the third aspect of the present invention, the work process determination means is provided with a timer for determining the time required for the progress of the work process, so that the work rhythm can be confirmed, and highly accurate determination can be made.

[Brief description of the drawings]

FIG. 1 is a diagram showing a circuit configuration of a light beam type safety device illustrating an embodiment of the present invention.

FIG. 2 is a diagram illustrating the operation of the circuit configuration.

FIG. 3 is a perspective view of the light beam type safety device.

FIG. 4 is a diagram showing a circuit configuration of a light beam type safety device according to another embodiment.

FIG. 5 is a diagram for explaining the operation of the circuit configuration shown in FIG. 4;

[Explanation of symbols]

 5 Workpiece 11 12 Light-emitting element 14, 15 Light-receiving element 16, 16a Work sensor

Claims (3)

(57) [Claims] 1. Forming a plurality of layers of light beams from the outside toward the inside around the processing machine, stopping the operation of the processing machine when at least one layer is cut off, further blocking the light beams of the plurality of layers or the light beam. In the light beam type safety device, which determines the work process by judging the order of dissolution, a work sensor that detects the work set at the processing position of the processing machine, and a light beam from the outer layer to the inner layer Work set determining means for detecting that the work has been set by detecting the generation of a work detection signal, and an inner layer when the work set determining means has determined that the work has been set. Escape determination means for detecting that the interruption of the light beam in the layer outside of the work set is eliminated in order, and determining that the work set portion has escaped; and In the state where it is determined that the set portion has escaped, the work detection signal disappears, and then it is detected that the interruption of the light beam from the inner layer to the outer layer is sequentially eliminated, and it is determined that the work removal has been completed. A work take-out judging means for newly activating the work set judging means, wherein the escape judging means puts the processing machine into an operable state when it judges that the work set section has escaped. The beam type safety device. 2. In a state in which the work taking-out judging means judges that the work set portion has escaped, the work taking-out operation is detected by detecting that light rays from the outer layer to the inner layer are cut off in order. Extraction start determination means for determining that the work has been started, and a work detection signal disappears in a state where the extraction start determination means has detected that the work extraction operation has been started, and then the light beam from the inner layer to the outer layer is blocked. 2. A light beam type safety device according to claim 1, further comprising a take-out completion judging means for detecting that the work is taken out and sequentially judging that the work take-out is completed. 3. The light beam system according to claim 1, wherein the work set judging means, the escape judging means and the work taking out judging means are provided with a timer for detecting that the judgment process is advanced within a set time. Safety device.