JP4071878B2 - Light safety device with control function - Google Patents

Description

[0001]
BACKGROUND OF THE INVENTION
The present invention relates to a light safety device in a press machine, and more particularly to a light safety device with a control function that limits the escape range of a hand or arm and drives the press machine more safely.
[0002]
[Prior art]
Some industrial machines are equipped with a light safety device with a control function that prohibits the activation of the press machine when the operator's body is in a dangerous position, like a press machine. For example, FIG. 5 is a diagram illustrating an example of such a light beam safety device with a control function.
[0003]
As shown in the figure, the light safety device with a control function is provided between a press machine and an operator, and includes a light emitting unit 1, a light receiving unit 2, and a control unit 3. Then, according to the control signal output from the control unit 3, the light emitting unit 1 emits light 1-2, 1-3,..., 1-n sequentially from, for example, the uppermost light emitting element 1-1, and the light receiving unit 2 The corresponding light is received by the light receiving elements 2-1, 2-2, 2-3,.
[0004]
When the press machine is descending, when the light emitted from one of the light emitting elements cannot be received by the corresponding light receiving element, it is assumed that a part of the worker's body is in a dangerous position for the operation of the press machine. Drive, that is, lowering start of the press machine is prohibited. When the light emission from the light emitting element is interrupted while the press machine is lowered, the press machine is immediately stopped. When the operator inserts the material into the mold while the press machine is moving up or when the top dead center is stopped, that is, when the light emission from the light emitting element is interrupted and then the light emission from the light emitting element is received by the light receiving element. Start the machine.
[0005]
[Problems to be solved by the invention]
However, in the conventional light safety device with a control function, the hand or arm moves above or below the optical axis (group), and the light beam is emitted even though the hand or arm is in the mold (on the press machine side). This may cause light transmission and activate the slide of the press machine, which may cause disasters.
[0006]
For example, the worker may drop the material on the floor in an attempt to put the material into the mold, and pick up the material with the other hand while keeping the arm in the mold (on the press machine side). In such a case, the arm moves downward from the optical axis (group) and the optical axis passes through, so the press machine is activated even though the arm (hand) is still in the mold (on the press machine side). Result. In addition, this means that the hand or arm accidentally moved above the optical axis (group) beyond the upper end of the optical axis (group) even though the hand or arm was in the mold (on the press machine side). It is a problem that occurs in some cases.
[0007]
The present invention is not a normal operation, and the hand or arm has escaped from outside the escape range, or a part of the body is still in the mold (press machine side) above or below the optical axis (group). When a hand or arm moves, the beam type safety device is provided to prevent the press machine from starting and ensure safety.
[0008]
[Means for Solving the Problems]
According to the first aspect of the present invention, in the light safety device with a control function in which a plurality of optical axes are formed in a vertical line between the press machine and the operator, the line-shaped optical axis is a normal one. The operator's body is composed of an optical axis of a hand or arm escape range in a press operation , an optical axis of an upper detection range formed above the optical axis, and an optical axis of a lower detection range formed below the optical axis. the optical axis of a part the upper detection range of, or a storage means for recording that escaped from the optical axis of the lower detection range, the optical axis of the upper detection range in said storage means, or from the optical axis of the lower detection range This can be achieved by providing a beam-type safety device with a control function having start-stop means for prohibiting start-up of the press machine when there is a record of escape.
[0009]
That is, the optical safety device with a control function according to the present invention has a plurality of optical axes formed vertically between an operator and a press machine and shields light during normal material setting operation, and above and below the optical axes. An auxiliary optical axis is provided, and this auxiliary optical axis is not an escape range of a hand or arm for a normal material setting operation by an operator, but is abnormal when the auxiliary optical axis is shielded immediately before passage, for example, `` “Light shielding abnormality” is stored, and when the light shielding state is changed from the “light shielding abnormality” state, hands and arms may remain in the press machine, and the press machine is prohibited from starting.
[0010]
By comprising in this way, a safer starting of a press machine is enabled by the light type safety device with a control function of this example.
[0013]
DETAILED DESCRIPTION OF THE INVENTION
Hereinafter, embodiments of the present invention will be described in detail with reference to the drawings.
FIG. 1 is a schematic diagram of a light safety device with a control function used in this embodiment, and includes a configuration of a press machine. In the press machine 4, a slide 5 is positioned on the upper portion thereof, the slide 5 is driven up and down, and the slide 5 is provided with an upper die (not shown). A lower die (not shown) is attached to the lower portion 6. Moreover, a material is put between the above-mentioned upper mold and lower mold, and press working is performed.
[0014]
Further, a light beam safety device 7 with a control function of this example is disposed in front of the press machine 4. This light safety device 7 with a control function is composed of a light emitting unit 8 and a light receiving unit 9, and sequentially emits light from each light emitting element provided in the light emitting unit 8 according to a control signal output from the control circuit. The light receiving element receives light. Therefore, the number of light receiving elements is also set to correspond to the number of light emitting elements, and the light receiving elements receive only light from the light emitting elements facing each other.
[0015]
In addition, an operator (not shown) is positioned in front of the above-described light safety device 7 with a control function. Therefore, an operator (not shown) has a relationship of facing the press machine 4 with the light beam safety device 7 with a control function interposed therebetween. That is, the operator reaches the material on the lower mold through the light beam safety device 7 with a control function by holding the material in order to place the material on the lower mold. At this time, one of the optical axes is blocked. Accordingly, at this time, the press machine 4 is not driven even if, for example, a press drive instruction is given.
[0016]
The light reception signal detected by the light receiving unit 9 is output to a control box 10 having a control circuit. The control circuit provided in the control box 10 is a circuit for controlling the light emission from the light emitting unit 8 and detecting and controlling the light received by the light receiving unit 9, and a memory and a drive circuit for storing a program to be described later. It is configured.
[0017]
FIG. 2 is a diagram for explaining in detail the optical axis forming configuration of the light safety device 7 with a control function of this example, and shows the configuration of the light emitting unit 8 (or the light receiving unit 9), for example. In the figure, a light emitting section 8 (or light receiving section 9) has light emitting elements (or light receiving elements) arranged vertically, and creates a plurality of optical axes 11 between the light emitting elements and the light receiving elements. In this example, the optical axis 11 has 56 optical axes, and further 8 optical axes are arranged as optional optical axes 12 in the upper part.
[0018]
Here, for example, optical axes “1”, “2”, “3”,..., “56” are attached to the optical axis 11 from the bottom. Further, the arrangement interval of the optical axes “1”, “2”, “3”,..., “56” is, for example, 10 mm, and the protection range by the optical axis group is 560 mm. Among these, the range of light shielding in the normal press operation (the escape range of the hand (arm) for normal operation) is, for example, optical axes “4” to “50” shown in FIG. On the other hand, the optical axes “1” to “3” are the lower detection range, and the optical axes “51” to “56” are the upper detection range. That is, the lower detection range and the upper detection range are ranges in which hands and arms do not escape during a normal press operation.
[0019]
The optical axes “57” to “64” are the upper option danger detection range. In this example, the optional optical axis is also provided in this region.
In the above configuration, the processing of this example will be described below with reference to the flowchart shown in FIG.
[0020]
First, the light emitting unit 8 emits light according to a synchronization signal generated in the light emitting unit, and the light receiving unit 9 sends a light reception signal to the control unit according to the same synchronization signal. The control unit performs processing according to the flowchart shown in FIG. In the description of this example, it is assumed that the main power supply has already been turned on for the press machine.
[0021]
First, it is determined whether or not the press machine 4 is in a dangerous area (step (hereinafter referred to as S) 1). Here, the dangerous area refers to the case where the slide 5 of the press machine 4 is descending from the top dead center toward the bottom dead center. “Outside” means that the slide 5 is being lifted or the slide 5 is stopped at the top dead center.
[0022]
In the above-described determination (S1), first, when the press machine 4 (slide 5) is not in the descending danger area (S1 is NO), the optical axis shielding is determined (S2). That is, it is determined which one of the optical axes has been blocked, and when the optical axis is blocked by the intrusion of an arm or the like (S2 is YES), a light blocking storage is performed (S3).
[0023]
Specifically, the light shielding storage (S3) is performed by the following processing. First, it is determined whether or not the light-shielded optical axis is an optical axis of “4” to “50” (S4). The optical axes “4” to “50” are optical axes within a normal escape range when a human hand or arm escapes, and the optical axes “4” to “50” within the escape range are shielded from light. (S4 is YES), the light shielding is normal (S5), and this “light shielding normal” state is set as the above-described light shielding memory.
[0024]
On the other hand, if the light shielding range is the optical axis “1” to “3” or “51” to “64” (S4 is NO), the light shielding is abnormal (ST5). That is, in this case, the light shielding position by the hand or arm is not abnormal, not the optical axes “4” to “50” within the escape range. Therefore, in this case, there are hands and arms at positions that do not normally exist in normal operation. For example, in order to pick up an object (for example, material) that has fallen on the floor, one hand or arm is pushed out toward the press machine 4 and the other It is conceivable to pick up fallen objects with your hand. Therefore, in this case, as described above, the optical axis outside the escape range is blocked, and the “light blocking abnormality” is stored as the light blocking storage because the light blocking range is abnormal (S6).
[0025]
The information of “light shielding abnormality” or “light shielding normal” set as described above is stored in a memory (not shown) and used in the determination (S7) described later.
After the light-shielding storage is performed as described above, when the light transmission state is changed, the memory is searched to determine whether or not the above-described light-shielding storage is present (S7). Here, if there is no light shielding storage (S7 is NO), normal processing is performed. On the other hand, when there is light shielding storage (S7 is YES), the storage state stored in the memory is determined (S8). Here, for example, if the state before light passing is “normal light shielding” (YES in S8), the light shielding is canceled from the “normal light shielding” state, and the hand or arm moves above or below the optical axis. Without moving, the press machine 4 is driven (moved) in the direction of the operator side and is determined to be a normal operation. That is, when the press machine 4 is at the top dead center, the drive relay is turned on (S9), and the slide 5 lowering process is started (S10). If the top dead center is not detected yet (S9 is NO), since the press machine 4 (slider) is still rising, the press machine 4 continues to rise.
[0026]
On the other hand, if the stored information read from the memory is “light shielding abnormality” (NO in S8), an erroneous operation process is performed (S11). That is, in this case, the light transmission state is changed from the “light blocking abnormality” state, and the light transmission state is changed from the state where the optical axes “1” to “3” or the optical axes “57” to “64” are blocked. It has changed to. Therefore, for example, this is a case where the hand or arm that has shielded the optical axes “1” to “3” has moved further downward to enter a light-transmitting state, and an example of this case is shown in FIG. The same applies to the case where the hand or arm that has shielded the optical axes “57” to “64” moves further upward and enters a light-transmitting state. An example of this case is shown in II of FIG.
[0027]
Therefore, in this case, activation of the press machine 4 is prohibited and an erroneous operation process is performed (ST6). For example, in the state where the drive of the press machine 4 is stopped, the material or the like that has dropped below the press machine 4 is picked up.
[0028]
Next, when the press machine 4 is activated, the slide 5 of the press machine 4 is lowered and is in the danger area (YES in S1). At this time, if the optical axis is blocked (S12 is YES), the sudden stop relay is turned off (S13), and the start relay is turned off (S14). By processing in this way, the drive of the press machine 4 is suddenly stopped.
[0029]
If the optical axis is not shielded during this time (NO in S12), the sudden stop relay is turned on (S15), and the press machine 4 is determined to rise (S16). In this case, the press machine 4 is lifted from the above description (S16 is YES), and the activation relay is turned off (S17).
[0030]
By operating as described above, it is possible to prevent the press machine 4 from being started while the hands and arms remain on the press machine 4 side, and to ensure the safety of the press machine 4. In the description of the above-described embodiment, the case of the optical axis (group) of one line shown in FIG. 2 has been described.
[0031]
【The invention's effect】
As described above, according to the present invention, when a hand or arm is pulled out from above or below the optical axis formed between the press machine and the operator, a part of the operator's body can remain on the press machine side. Therefore, the start of the press machine is prohibited, and a light-type safety device with a safer control function is provided.
[Brief description of the drawings]
FIG. 1 is a schematic diagram of a light beam safety device with a control function used in this embodiment, and includes a part of the configuration of a press machine.
FIG. 2 is a schematic cross-sectional view of FIG.
FIG. 3 is a flowchart illustrating a processing operation according to the present exemplary embodiment.
FIG. 4 is a diagram illustrating an operation state of this example.
FIG. 5 is a diagram for explaining a configuration of a conventional beam safety device.
[Explanation of symbols]
4 Press machine 5 Slide 6 Lower part 7 Light beam safety device 8 with control function Light emitting part 9 Light receiving part 10 Control box 11 Optical axis 12 Optional optical axis 13 Hand (arm)

Claims (1)

In a light safety device with a control function that forms a plurality of optical axes in the form of a line between the press machine and the operator,
The line-shaped optical axis is the optical axis of the escape range of the hand or arm in a normal press operation ,
The optical axis of the upper detection range formed above the optical axis and the optical axis of the lower detection range formed below ,
Storage means for recording that part of the worker's body has escaped from the optical axis of the upper detection range or the optical axis of the lower detection range ;
An activation stop means for prohibiting activation of the press machine when there is a record of escape from the optical axis of the upper detection range or the optical axis of the lower detection range in the storage means;
A beam type safety device with a control function.

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