JP3443292B2 - Beam safety device - Google Patents

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention forms a layered light beam around a processing machine, stops the operation of the processing machine when the light beam is interrupted, and judges the work process based on the interruption or cancellation thereof. The present invention relates to a light beam type safety device used in a processing machine such as a press machine.

[0002]

2. Description of the Related Art According to Japanese Patent Laid-Open No. 3-140698,
A plurality of layers of light rays are formed from the outer side to the inner side of the processing machine, and the light beam cutoff signal is input, and when at least one layer is cut off, the operation of the press machine is stopped, and
There is disclosed a light beam safety device capable of preventing a worker from entering the inside of a light beam and recovering an apparent abnormality by determining the order of blocking light beams of a plurality of layers and the elimination order thereof.

On the other hand, if a device for judging entry and exit of a work set part such as an operator's hand and a robot arm is constructed by judging such interruption and its elimination order, in principle, every time or By making the processing machine ready for operation every two intrusion / escape processes, the work process can be automatically and more reliably determined. In view of the possibility that unexpected light beam blocking may occur due to irregular movements of the worker, the applicant of the present application has filed Japanese Patent Application No. 9-47253 to block multiple layers of light beams and the order of eliminating the same. In addition to the above judgment, by judging whether or not the workpiece is set in the machining position, it is possible to more accurately judge the operable state of the machining machine, that is, the automatically operable state or the manually operable state. A light beam safety device was proposed.

[0004]

However, with this type of device, it is detected that the light blocking from the inner layer to the outer layer is sequentially eliminated in the state where it is determined that the workpiece is set in the lower die of the processing machine. When it is judged that the operator's hand has escaped, instead of pulling the hand out from the inside of the array surface of the light receiving element that receives the layered light beam, it escapes to the outside when the hand is moved up or down. There is a possibility that it may be judged that the light blocking has been resolved in order despite not doing so, and there is a problem in its integrity.

In this case, the light receiving elements may be arranged without gaps up to the lower surface of the processing machine or a sufficiently high position. However, this may not be possible due to the structure of the machine. It is also advantageous in terms of cost.

In view of the above points, the present invention has an object of further improving safety in a light beam type safety device which makes a working machine operable by judging whether or not a layered light beam is blocked or eliminated. And

[0007]

In order to achieve this object, the present invention forms a plurality of layers of light rays around a processing machine according to claim 1, and vertically receives a plurality of light rays at opposing positions. By arranging the elements in multiple rows, the operation of the processing machine is stopped when the light beam incident on this light receiving element is blocked, and the work set part escapes from the processing position when the light beam blocking of multiple layers is resolved. According to claim 2, a plurality of light beams are formed around the processing machine according to claim 2, and a plurality of light beams are formed around the processing machine in the vertical direction. By arranging multiple light receiving elements in multiple rows, the operation of the processing machine is stopped when the light rays that enter the light receiving elements are blocked, and the work sensor that detects the work set at the processing position and the outer layer Rays Luo inner layer is cut off in order,
Next, a work set determining means for detecting that a work detection signal is generated and determining that the work is set, and a light beam from the inner layer to the outer layer in the state where the work set determining means determines that the work is set In the light beam type safety device equipped with the escape determination means for detecting that the work pieces have been escaped by detecting that the interruptions of are eliminated in order and making the processing machine operable, It is characterized in that an operation stopping means is attached to make the escape judging means inoperable in response to a light blocking signal detected by one or a plurality of light receiving elements at the lower end of the array.

At the time of eliminating the light beam interruption in which the light beam interruption of a plurality of layers at the time of taking out the work is eliminated, the work set portion is shifted downward without coming out to the light receiving element at the lower end portion of the array of the outermost layer. When the incident light beam is blocked, the operation stopping means disables the escape determining means in response to the light beam blocking signal. At this time, according to the third aspect, the operation stopping means is configured to disable the escape determining means in response to the light blocking signal of one or a plurality of light receiving elements at the upper end portion of the array of the light receiving elements in the outermost layer. You can also do it. In a multi-layered light beam safety device according to claim 4, wherein the array end portion of the light receiving element is formed as a single layer, the operation stopping means is a light beam detected by one or a plurality of light receiving elements of the single layer at the array end portion. The escape determination means is configured to be inoperable in response to the shutoff signal.

[0009]

BEST MODE FOR CARRYING OUT THE INVENTION A light beam type safety device according to an embodiment of the present invention will be described with reference to FIGS. 1 to 3. Figure 3
Shows a press machine for bending a workpiece 5 made of a metal material interposed between an upper die 2 and a lower die 3 attached to a slide 1 into a predetermined shape. A bracket 10 for a projector is attached to one side of the front surface, light emitting elements 11 and 12 are arranged from the upper side to the lower side, and two layers of light rays are formed on a vertical surface. On the other side, brackets 20 for light receivers are arranged so as to face each other, and light-receiving elements 14 and 15 are similarly arranged in two layers at positions facing the above-mentioned light-emitting elements. A light receiving signal processing circuit 19 follows these light receiving elements, and when any of the layered light rays incident on the light receiving element 14 is blocked, a light beam blocking signal L1 of the outer first layer is generated, and the inner two layers. When any one of the optical axes incident on the light receiving element 15 of the eye is blocked, the light blocking signal L2 is output. 16 is the lower mold 3
Is a light irradiator for irradiating a light beam toward the work 5 set in the above, and a work sensor for detecting the presence or absence of the work 5 is provided by arranging the light receiver 16a at the opposite position to detect the presence or absence of the light beam. I am configuring.

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 worker puts the work 5 in and out of the press machine. In this means, the outer layers of the plurality of light emitting elements 11 and the light receiving elements 14 are blocked by the operator's hand, which is the work set section, and the light rays of the inner layers of the light emitting elements 12 and the light receiving elements 15 are blocked. The work set determining means 31 for detecting that the work detection signal w is output from the work sensors 16 and 16a and determining that the work 5 is set, and the work set determining means 31 for setting the work 5 in the lower mold 3. In the state where it is determined that the light blocking of the inner layer is canceled, and then the light blocking of the outer layer is cleared, it is determined that the operator's hand has escaped, and an escape signal a is generated. With the means 32 and the escape determining means determining that the worker's hand has escaped, the light rays of the outer layer are blocked, and then the inner layer is blocked to detect the work take-out operation. The removal start determination means 33 for determining that the work has been performed, and the work detection signal w disappears in a state where the removal start determination means determines that the work removal operation is started, and then the light blocking from the inner layer to the outer layer is eliminated in order. It is determined that the work 5 has been completely picked up by detecting that the work 5 has been picked up, and the work set judging means 31 is newly operable.

The take-out / starting decision means 33 detects the lowering of the upper die 2 and automatically generates a press operation signal p.
In response to, the judgment operation becomes possible. The take-out start judging means and the take-out completion judging means 34 constitute a work take-out judging means. In the judgment process of each means described above, if the judgment process is not stepped within a predetermined time, the judgment operation of the means is reset and a new judgment operation is started.

Reference numeral 21 is an OR gate functioning as a stop signal generation circuit, which stops the operation of the 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 input. A stop release signal generating means 24 generates a stop release signal c in response to the escape signal a, and its generation is reset at the end of the press operation signal p. Reference numeral 25 is a touch switch for starting the operation of the press, which outputs its operation signal by wire or wirelessly and supplies a start signal o to the drive control circuit 22 through the AND gate 26.

The operation of the safety device thus constructed will be described with reference to FIG. Normally, the stop release signal generating means 2
In No. 4, the stop release signal c is not generated even when the layered light beam is not blocked, and the touch switch 25 is operated 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 in which both the light beam cut-off signals L1 and L2 are absent and the work detection signal w is absent (step S2). Then, when the second layer is also cut off (step S3) and the work detection signal w is subsequently generated (step S4), it is determined that the work 5 is set at the machining position.

The escape judging means 32 is thus arranged to work 5
After it was determined that was set, the interruption of the second layer was canceled (step S5), and then the interruption of the first layer was also canceled (step S6), and the operator's hand escaped. Then, the escape signal a is generated, and in response to this, the stop release signal c is generated. In this state, by operating the touch switch 25, the start signal o is output through the AND gate 26, and the drive control circuit 22 causes the work 5
In addition to the press working, the stop release signal generating means 24 is reset at the end of the press operation signal p to stop the generation of the stop release signal c.

The take-out / moving start judging means 33 further presses the press operation signal p when it is judged that it has escaped as described above.
First, the first layer is cut off (step S).
7) Then, if the second layer is also cut off (step S8),
It is determined that the work 5 has been taken out. In the state in which it is determined that the taking-out is started in this way, the work-out detection signal w disappears first (step S9), and then the interruption of the second layer is eliminated (step S1).
0), and then the interruption of the first layer is also canceled (step S
11) It is determined that the work 5 has been taken out, and the next determination cycle is started.

The configuration of the safety device described above is Japanese Patent Application No. 9-
Although it is the same as that described in the specification of 47253, the escape judging means 32 is provided with the operation stopping means 39 for disabling its operation according to the present invention. Further, the light receiving signal processing circuit 19 outputs, for example, the light blocking signals LB1 of the three light receiving elements 14 from the lowermost position of the first layer and the light blocking signals LT1 of the three light receiving signals 14 from the uppermost position of the first layer. .
The operation stopping means 39 stops the stepping operation of the escape determining means 32 when at least one of the light-reception cutoff signals is generated, and therefore these light-beam cutoff signals LB1, L are generated.
With T1 disappeared, the escape determination means 32 remains in the state before that. That is, the escape determination unit 32 outputs the light beam cutoff signal LB1 or LT1 when the outer first layer cutoff is released downward or upward after the work 5 is determined to have been set, and is eliminated. It occurs and does not proceed to step S6.

Thus, when the work set is completed and an object is dropped when the hand is to be ejected, the hand is slid downward without being ejected to the outside so that the lower end of the array 3
When at least one of the light-receiving elements 14 is blocked, the escape determining means 32 stops the determining operation. Then, when the hand is again inserted into the light beam to escape, the escape determination means 32 performs a normal operation again and outputs the escape signal a. Similarly, the operation of the escape determination means 32 is stopped even when the hand of the worker rises up due to a stand-up or the like.
It should be noted that the light-receiving elements at the end portions of these arrays generate the light beam cutoff signal L1 when the incident light beam is cut off not only for such an operation stop but also for a safe operation at all times.

FIG. 4 shows another embodiment in which one light receiving element 15 of the second layer is saved in the lower end portion of the array and three light receiving elements 15 are saved in the upper end portion of the array in the above-described embodiment. That is, the light-receiving signal processing circuit 19a outputs the light-receiving cutoff signal LB1 when the light-receiving signal of the single light-receiving element 14a which is a single layer at the lower end of the first layer is cut off, and the light-receiving signal LB1 is output at the upper end of the array. When any one of the light receiving elements 14b is blocked, the light beam blocking signal LT1 is output. As a result, the safety is assured in a wider area of the first layer, and the second layer can be set narrower in accordance with the normal range of passage of the work set portion in order to make it cost effective. For some reason, when a hand or the like is taken out after the work is set and slips upward or downward from the normal passage range, the light is blocked by at least one light receiving element 14b or light receiving element 14a.
The light interception signal LT1 or LB1 is generated, and the operation of the escape determination means 32 is stopped.

The light beam type safety device having a plurality of light beam layers does not have a work detecting means, and is provided once every three times or more than every two times when the work is set out every time or when the work is taken out from the processing position. It is also conceivable to provide escape determination means for determining that the work set part has escaped at the time when the light blocking of the plurality of layers is sequentially eliminated, and making the processing machine operable. At this time, it is possible to add not only the blocking from the inside to the outside but also the blocking from the outside to the inside in order to the judgment information. According to the present invention, the operation of the escape determining means can be stopped by using the shutoff signal of one or a plurality of light receiving elements in the array end portion also in this type of safety device. Similarly, when the element array range of the outermost layer is wide, the cutoff signal of the light receiving element at the array end portion of the single layer is used.

[0021]

According to the first aspect of the present invention, it is judged that the work set part has escaped each time or every time the plural times of interruption of the plural layers of light rays are eliminated, and the plural layers of rays of light for making the working machine operable. Safety device or claim 2
According to the invention of claim 1, a plurality of layers of light rays are formed and a work sensor is arranged, and in the light ray type safety device of a plurality of layers for judging escape of the work set part by the presence or absence of the work set part and the elimination order of the light block, If the arm, etc., does not pass the light beam from the inside to the outside and remains below the ray layer, there is a risk that the hand, robot arm, etc. may be judged to have escaped and the processing machine may be activated. Avoided. Therefore, the reliability of the safety device is prevented from being lowered when the light receiving elements cannot be arranged in the entire region to be protected without a gap due to the structure of the processing machine or when the number of elements to be arranged is reduced in terms of cost.

According to the invention of claim 3, claim 1 or 2
In the multi-layered light beam safety device, the risk of the work set portion coming out upward can be avoided. According to the invention of claim 4, in the multi-layered light beam safety device according to claim 1 or 2, even when the upper end portion or the lower end portion of the outermost light receiving element array is formed as a single layer, the work set portion is provided. It is possible to avoid the risk of falling out upward or downward, and to avoid the risk associated with narrowing the judgment range in terms of cost or structure.

[Brief description of 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 an operation of the circuit configuration.

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

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

[Explanation of symbols]

5 work 11, 12 Light emitting element 14, 14a, 14b, 15, light receiving element 16, 16a Work sensor

Claims (4)

(57) [Claims] 1. When a plurality of layers of light rays are formed around a processing machine and a plurality of light receiving elements are arranged vertically in a plurality of rows at opposite positions, the light rays incident on the light receiving elements are blocked. A light beam type equipped with an escape determination means that stops the operation of the processing machine and determines that the work set part has escaped from the processing position when the light blocking of multiple layers is resolved and makes the processing machine operable. The safety device is further provided with an operation stopping means for disabling the escape determining means in response to a light blocking signal detected by one or a plurality of light receiving elements at the lower end portion of the array of the outermost light receiving elements. Ray-type safety device that does. 2. A plurality of layers of light rays are formed around a processing machine,
By arranging a plurality of light receiving elements in a row in the vertical direction at the facing position, the operation of the processing machine is stopped and the work set at the processing position is detected when the light beam entering this light receiving element is blocked. Work sensor, a work set determination means for determining that a work is set by detecting that a light beam from the outer layer to the inner layer is sequentially blocked, and then a work detection signal is generated, and the work set determination means. When it is determined that the work has been set, it is determined that the blocking of the light rays from the inner layer to the outer layer is eliminated in order and it is determined that the work set part has escaped, and the processing machine is set to the operable state. In a light beam type safety device having an escape judging means, an escape judgment is made in response to a light beam interception signal detected by one or a plurality of light receiving elements at the lower end portion of the array of the light receiving elements in the outermost layer. Beam safety device, characterized in that the operation stopping means for disabling the means is attached. 3. The operation stopping means, in addition to or in place of the light receiving element at the lower end of the array, outputs a light blocking signal of one or a plurality of light receiving elements at the upper end of the array of the outermost light receiving elements. 3. The light beam safety device according to claim 1 or 2, wherein the escape determination means is rendered inoperable in response. 4. The array end portion of the light receiving elements is formed as a single layer, and the escape judging means is made inoperable in response to a light blocking signal detected by one or a plurality of the light receiving elements of the single layer. The light beam type safety device according to claim 1 or 2, further comprising an operation stopping means for operating.