JP3197940B2 - Work suction controller - Google Patents

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a work suction control device and, more particularly, to a work suction control device for preventing a suction pressure from being reduced when a work is conveyed in a press line that sucks a work and sequentially conveys the work to a subsequent process. The present invention relates to a device for securing a press line.

[0002]

2. Description of the Related Art In a press line for sequentially transporting a work to a subsequent process, sequentially performing press working, and carrying out a predetermined product, a work transfer device for transporting the work to a subsequent process is provided.

This work transfer device has a vacuum cup, and the vacuum cup is operated to generate a vacuum in the vacuum cup to clamp the work. By the way, the work conveyed from the previous process may be removed for reasons such as defective products. However, conventionally, the vacuum pad of the work transfer device corresponding to the removed station is operated even though the work is removed and there is no work to be clamped.

Further, even if there is a workpiece to be clamped, the suction pressure of the vacuum cup is reduced to a pressure (negative pressure) less than a sufficient pressure for clamping, for example, because the workpiece cannot be clamped at an appropriate clamping position. That is, a so-called suction error may occur. Conventionally, even if a suction error occurs, the vacuum cup of the corresponding work transfer device is operated.

[0005]

Generally, each vacuum cup of a plurality of work transfer devices is operated not by an independent air pressure circuit but by a partly common air pressure circuit, and a negative pressure is applied to a common tank. Be guided. For this reason, if the vacuum cup operates even when no work is present, the negative pressure in the vacuum cup naturally decreases, and this reduction in pressure causes a decrease in the suction pressure of the vacuum cup in another station. Will be invited. For this reason, it becomes impossible to convey a heavy work at high speed, and there is a possibility that work efficiency may be reduced.
Further, in some cases, the clamp may not be sufficient, which may cause a serious accident such as dropping of the work.

[0006] In addition, when the above-mentioned suction error occurs, a similar problem due to a decrease in the suction force occurs, and it is necessary to prevent this.

The present invention has been made in view of the above circumstances, and an object of the present invention is to provide a work suction control device for preventing a situation in which safety is impaired due to a decrease in suction pressure.

[0008]

According to a first aspect of the present invention, a work is conveyed between presses by a conveying means to the next press sequentially in each cycle, and when the work is conveyed to each press. Then, in a work suction control device that operates the work suction means provided in the transfer means for transferring the work to the next press to suction the work, provided in each press, according to the removal of the work A work removal switch that is operated to output a work removal signal, and an information updating unit that updates information on the presence or absence of a work in each press every cycle according to the presence or absence of the work removal signal output from the work removal switch. And, in the press updated without the work by the information updating means, the work provided in the conveying means for conveying the work to the next press. The work suction means is controlled so as not to operate the work suction means, and in the press updated with the work by the information updating means, the work suction means provided in the transfer means for transferring the work to the next press is operated. Control means for controlling the work suction means so as to cause the work suction means.

According to a second aspect of the present invention, the work is conveyed between the steps by the transfer means, and the work suction means provided in each step is activated when the work is transferred to each step by the transfer means. In the work suction control device configured to suck the work at a predetermined suction pressure or more, the suction pressure detection means for detecting the suction pressure of the work suction means, and the suction pressure detected by the suction pressure detection means. Is smaller than the first adsorption pressure and the first
When the suction pressure is equal to or higher than a second suction pressure lower than the suction pressure, it is determined that a suction error of the work has occurred, and when the suction pressure detected by the suction pressure detecting means is lower than the second suction pressure. A determination means for determining that there is no work to be sucked, and when the determination means determines that a suction error of the work has occurred, the work suction means is kept operated, and the determination means determines And control means for controlling not to operate the work suction means when it is determined that there is no work to be sucked.

[0010]

According to the structure of the first aspect of the present invention, the work suction means corresponding to the step in which no work exists does not operate, so that the suction pressure of the work suction means in other steps does not decrease, and the work is strongly clamped. It is possible to transport at high speed, and the safety is improved.

According to the second aspect of the present invention, when the suction pressure is smaller than the first suction pressure and is in the range equal to or higher than the second suction pressure, it is determined that a suction error has occurred and the work suction means is determined. Remain activated. Here, the reason why the workpiece is kept operated is that if the workpiece is not operated, the workpiece may be in an unclamped state, and the workpiece may drop during the transportation and a serious accident may occur. Then, the operation in each step and the transportation between the steps can be stopped based on the determination result, and measures such as shifting to a manual operation for safety can be taken. On the other hand, if the suction pressure is
If the suction pressure is smaller than the suction pressure, it is determined that there is no work instead of the pressure drop due to the suction error, and the work suction means is not operated. In this case, since there is no work, there is no safety problem even in the unclamped state. Since the work suction means does not operate, the suction pressure of the work suction means in another process does not decrease, and the work can be strongly clamped and conveyed at high speed, thereby improving safety.

[0012]

BRIEF DESCRIPTION OF THE DRAWINGS FIG. 1 is a block diagram showing an embodiment of a work suction control device according to the present invention.

FIG. 3 shows the appearance of a press line applied to the embodiment.

As shown in FIG.
The workpieces WK are sequentially processed according to 00, 200, 300,... To produce a predetermined product, and the product is carried out. A supply device for supplying the work WK to the press line is provided at the forefront of the press line, and an unloading device for unloading the processed product is provided at the end of the press line, but these are omitted. In steps 100, 200, and 300, steps 120, 220, and 320 of a so-called single feed bar type internal work transfer device are provided, respectively.

Steps 120, 220, and 3 of the work transfer device
Reference numeral 20 is provided for transporting the workpiece WK that has been processed in the preceding step to the subsequent step. The process 220 of the work transfer apparatus will be described as a representative.
The workpiece WK, which has been processed by the process 0, is sucked and clamped by the vacuum cup 225 provided on the feed bar, and is carried into the mold 240 in the press.
The work WK, which has been pressed by the press, is sucked and clamped by the vacuum cup 226 provided on the feed bar, carried out of the mold 240, and then sent to the mold 3 in the subsequent step 300.
It operates so as to be mounted on 40.

A series of movements of the work transfer apparatus are realized by causing a feed bar to perform a vertical two-dimensional (lift (up and down) press feed (left and right)) feed motion.

The control device 210 controls the above steps 100 to 30
0, for driving control of the work transfer devices 120 to 320.

FIG. 1 shows the configuration of the air pressure control circuit 1 for operating the vacuum cup 226. As shown in FIG. 1, the air pressure control circuit 1 includes a pressure reducing valve 11 for reducing the pressure of air generated by a predetermined air pressure source 12 to a predetermined pressure, and a pressure reducing valve 11 generated by the air pressure source 12 by switching the valve position. A switching valve 4 for supplying the filtered air to the switching valve 2, an air supplied from the switching valve 4 by switching the valve position, to the filter 6, and the air passing through the filter 6 to the tank 6 via the passage 9. A switching valve 2 leading into 13;
Passage 8 for communicating vacuum cup 226 and filter 6
And a suction pressure detection sensor 7 for detecting the air pressure P in the passage 8, that is, the suction pressure of the vacuum cup 226.

Similar air pressure control circuits 15 and 17 are provided for the vacuum cups 225 and 227, respectively, and passages 16 and 18 similar to the passage 9 are led to the tank 13. The same applies to other vacuum cups. The tank 13 is connected to a vacuum pump 14 and is driven by a predetermined driving source.

The controller 210 inputs the suction pressure P of the vacuum cup detected by the suction pressure sensor 7 provided for each of the vacuum cups, and supplies an energizing signal to the solenoid 3 of the switching valve 2 and the solenoid 5 of the switching valve 4. S
1 and S2 are output to control the suction pressure of each vacuum cup.

By the way, each process 100, 200, 300
In some cases, the work WK may be removed from the press line for some reason. Therefore, each press is provided with a work removal switch that is operated in accordance with the work removal operation. When the switch is operated, a work removal signal is output to the control device 210.

The control device 210 determines the current process of each work WK... Based on the data of the production plan, and updates the current process of each work WK every cycle. For example, if there is data indicating that "this work WK1 is present in the mold 240 of the process 200" for the specific work WK1, after the next one cycle has elapsed, the "work WK1 is in the mold 340 of the process 300 in the succeeding stage.
In "is updated." However, the work WK
May not be continuous, so that the process in which the work WK exists as the data content is “work present”, and the process in which the work WK does not exist is “work no”.

Further, the control device 210 appropriately changes the content of "work present / absent" according to the content of the work removal signal. For example, in the process 200, the work WK
Is removed, the work WK in the mold 240 in the process 200 is changed from “work present” to “work not present”.

Hereinafter, the suction pressure control performed by the control device 210 will be described.

First control This first control is a control not using the detection value P of the suction pressure sensor 7.

That is, as described above, the control device 210
In each step, the presence / absence of a work in each step is determined, and the energization signals S1 and S2 are output to the respective switching valves so that only the vacuum cup corresponding to the step determined as “work present” is operated.

Taking the vacuum cup 226 as an example, if it is determined that the work WK to be clamped by the vacuum cup 226 is present, the control unit 21
From 0, an energizing signal S1 for deactivating the switching valve 2 is output to the solenoid 3, and an energizing signal S2 for energizing the switching valve 4 is output to the solenoid S2. As a result, air is guided to the tank 13 via the switching valve 2 in response to the driving of the vacuum pump 14, and the vacuum cup 226 sucks the work WK with a suction pressure of a predetermined negative pressure P1 or more (see FIG. 2).

On the other hand, when it is determined that the work WK to be clamped by the vacuum cup 226 is “absent”, the general control device 1000 sends an energizing signal S1 for energizing the switching valve 2 via the control device 210 to the solenoid. 3
And an energization signal S2 for deenergizing the switching valve 4 is output to the solenoid S2. As a result, air flows through the vacuum cup 22 through the air pressure source 12 and the pressure reducing valve 11.
6, the vacuum cup 226 is no longer at a negative pressure, and the air in the vacuum cup 226 is not guided to the tank 13 via the switching valve 2.

The air in the tank 13 is guided only from the vacuum cup which has been determined to be "work present". Here, if it is assumed that the air of the vacuum cup 225 is guided into the tank 13 via the switching valve 2 in spite of "no work" in the vacuum cup 226, the negative pressure in the tank 13 decreases, This leads to a reduction in negative pressure in other vacuum cups, but such a problem does not occur.

In the first control, the sensor 7
Is unnecessary, and by omitting it, the cost can be reduced.

Second control This second control is a control using the detected value P of the suction pressure sensor 7.

FIG. 2 shows the relationship between the press angle and the negative pressure P of the vacuum cup when there is a workpiece.
If it is operating normally, suction by the vacuum cup is not made in the section where the press is processing the work,
The suction by the vacuum cup is performed in the transport sections θ1 to θ2 in which the press does not process the work. Therefore, in this section θ1 to θ2, the negative pressure of the vacuum cup is equal to or higher than the negative pressure P1 sufficient to clamp the work. However, if a suction error occurs and the work is not securely clamped despite the presence of the work, the negative pressure becomes smaller than P1. Further, if the work itself does not exist, the negative pressure becomes smaller than the threshold value P2 set lower than P1.

Therefore, if the detection value P of the sensor 7 is smaller than P1 and equal to or larger than P2, it is determined that "suction error". If it is determined that the suction error has occurred in the vacuum cup 226, it is dangerous to continue the automatic operation as it is, so that the automatic operation is controlled to be stopped. However, all the vacuum cups including the vacuum cup 226 are kept in operation in order to avoid the work falling.

That is, an energizing signal S1 for deactivating the switching valve 2 is output from the control device 210 to the solenoid 3, and an energizing signal S2 for energizing the switching valve 4 is output to the solenoid S2. As a result, air is guided to the tank 13 via the switching valve 2 in response to the driving of the vacuum pump 14,
The vacuum cup 226 keeps the work WK sucked at a predetermined suction pressure. By switching to the manual operation in this state, the work WK can be transported safely without dropping, and necessary measures such as inspection can be performed.

On the other hand, when the detection value P of the sensor 7 is smaller than P2, it is determined that "there is no work". In this case, since the situation where the work falls from the vacuum cup 226 does not occur, in order to prevent the suction pressure from lowering, the energization signal S1 for energizing the switching valve 2 is supplied from the control device 210 as in the first control. While being output to the solenoid 3, an energization signal S2 for deenergizing the switching valve 4 is output to the solenoid S2. As a result, the air pressure source 12, the pressure reducing valve 1
1, air is supplied to the vacuum cup 226,
The vacuum cup 226 is no longer under negative pressure, and the air in the vacuum cup 226 is not guided to the tank 13 via the switching valve 2.

Air is introduced into the tank 13 only from other vacuum cups that have been determined to have "work", and no negative pressure drop occurs in other vacuum cups.

In the embodiment, a press working line is assumed, but the present invention is not limited to this and can be applied to work transfer in any machine working line.

[0038]

As described above, according to the present invention, the work suction means is controlled so as not to operate in a process where no work exists, so that the suction pressure of the work suction means in other processes does not decrease. . For this reason, the workpiece can be strongly clamped and transported at a high speed, and a situation in which the workpiece is dropped during transport is prevented beforehand, so that safety is dramatically improved.

[Brief description of the drawings]

FIG. 1 is a circuit diagram showing an air pressure control circuit in a work suction control device according to an embodiment of the present invention.

FIG. 2 is a graph showing a relationship between a press angle and a negative pressure in a vacuum cup.

FIG. 3 is a conceptual diagram showing a configuration of a press line according to an embodiment.

[Explanation of symbols]

 2 switching valve 4 switching valve 13 tank 14 vacuum pump 200 process (press) 210 controller

Claims (3)

(57) [Claims] The work is conveyed between presses by a conveying means to the next press in a cycle at a time, and when the work is conveyed to each press, the work is conveyed to the next press. In a work suction control device that operates the provided work suction means to suck a work, a work removal switch that is provided for each press and that is operated according to work removal and outputs a work removal signal; An information updating unit that updates information on the presence or absence of a work in each press in each cycle in accordance with the presence or absence of a work removal signal output from the work removal switch; In the press, the work suction means provided in the transfer means for transferring the work to the next press is operated so that the work suction means is not operated. In the press updated to include the work by the information updating means, the work suction means is controlled so as to operate the work suction means provided in the conveying means for conveying the work to the next press. A work suction control device comprising control means. 2. The method according to claim 1, wherein the work is conveyed between the steps by a conveying means, and when the work is conveyed to each step by the conveying means, a work adsorbing means provided in each step is operated to perform a predetermined first suction. In a work suction control device configured to suction a work at a pressure equal to or higher than a pressure, a suction pressure detection unit that detects a suction pressure of the work suction unit, and a suction pressure detected by the suction pressure detection unit is the first suction pressure. If the suction pressure is smaller than the second suction pressure and lower than the first suction pressure, it is determined that a suction error of the work has occurred, and the suction pressure detected by the suction pressure detecting means is equal to the second suction pressure. When the suction pressure is lower than the suction pressure, the determination unit determines that there is no work to be sucked, and when the determination unit determines that a suction error of the work has occurred, the work suction unit is Control means for controlling the work suction means so that the work suction means is not operated when the determination means determines that there is no work to be sucked. apparatus. 3. The method according to claim 1, wherein the control means stops the work in each step and the conveyance between the steps when the determination means determines that a suction error of the work has occurred. Item 3. The work suction control device according to Item 2.