Air pressure circuit for transport

Abstract

To provide an air pressure circuit for transport that can reduce energy consumption by more effectively utilizing the generated negative pressure than conventional circuits.SOLUTION: A control valve mechanism 6' includes a three-port valve 9' provided in the forward piping section and a two-port valve 7 provided in the rear piping section, the two-port valve 7 is controlled to open during adsorption and close during release. And the three-port valve 9' of the control valve mechanism 6' is controlled so as to be in a first state in which the negative pressure from a vacuum generator 4 is supplied to a suction pad 2 at the time of suction, and to be in a second state in which the supply of the negative pressure from the vacuum generator 4 is inhibited to form a negative pressure confining portion 10 with the two-port valve 7 and the suction pad 2 is opened to the atmosphere at the time of release. At the time of suction of the next conveying operation, the control valve mechanism 6' changes from the second state to the first state, and is controlled so as to use both the negative pressure in the negative pressure confinement portion 10 and the negative pressure from the vacuum generator 4.SELECTED DRAWING: Figure 5

Description

[Technical Field]

[0001] The present invention relates to a conveyance air pressure circuit that controls negative pressure supplied to one or more suction pads provided on a conveyance head. On the road It is related to. [Background technology]

[0002] Japanese Patent No. 4653984 discloses a molded product removal device having a transfer air pressure circuit including one or more suction pads attached to a chuck (transport head) for transporting a molded product (transported product), piping arranged between the one or more suction pads and a vacuum generator, and a negative pressure control unit having a negative pressure maintaining valve (control valve) arranged in the piping path to supply negative pressure from the vacuum generator to the one or more suction pads when the transported product is suctioned by the one or more suction pads, and to open the piping to the atmosphere when the transported product is released from the one or more suction pads. In this device, vacuum pressure is generated in the chuck while the chuck is moving from the standby position to the removal position, and the negative pressure in the chuck is controlled so that it reaches the suction pressure just when the chuck reaches the removal position. Therefore, compared to a system in which negative pressure is generated in the chuck in advance from the state in which the chuck has returned to the standby position, and the negative pressure in the chuck reaches the suction pressure when the chuck reaches the removal position, the suction ON signal is output just at the timing when the chuck reaches the suction pressure when the chuck reaches the removal position, which has the advantage of reducing the amount of compressed air consumed. [Prior art documents] [Patent documents]

[0003] [Patent Document 1] Patent No. 4653984 Summary of the Invention [Problem to be solved by the invention]

[0004] When a transported product is released from one or more suction pads in a conventional device, the negative pressure maintaining valve and vacuum generator are opened, the inside of the pipe is opened to the atmosphere, and all of the negative pressure in the pipe is consumed. Then, when the next suction operation is performed, the inside of the pipe is again brought to a negative pressure state. In this way, conventional devices consume a lot of energy to create a negative pressure inside the pipe each time. The longer the length of the pipe, the greater this energy consumption becomes.

[0005] SUMMARY OF THE INVENTION An object of the present invention is to provide a pneumatic circuit for conveyance that can reduce energy consumption by making more effective use of the generated negative pressure than in the past. [Means for solving the problem]

[0006] The pneumatic circuit for conveying of the present invention comprises one or more suction pads provided on the conveying head for conveying the transported item, piping arranged between the one or more suction pads and a vacuum generator, and a control valve mechanism having two or more control valves arranged in the piping path to supply negative pressure from the vacuum generator to the one or more suction pads when the transported item is suctioned by the one or more suction pads, and to open the inside of the suction pads to the atmosphere when the transported item is released from the one or more suction pads, and to form a negative pressure confinement section in which negative pressure is confined in a rear piping section which is closer to the vacuum generator than the front piping section, and to use both the negative pressure in the negative pressure confinement section and the negative pressure from the vacuum generator when suctioning the next transport operation.

[0007] According to the present invention, a portion of the negative pressure generated during suction is stored in the negative pressure containment section, and during suction in the next transport operation, the negative pressure in the negative pressure containment section and the negative pressure from the vacuum generating device are used in combination.This means that the generated negative pressure is not wasted but is partially reused, thereby reducing energy consumption compared to conventional methods.

[0008] A preferred control valve mechanism includes a three-port valve provided in the front piping section and a two-port valve provided in the rear piping section, the two-port valve being controlled to an open state during suction and a closed state during release. The three-port valve of this control valve mechanism is controlled to be in a first state during suction, in which negative pressure from a vacuum generator is supplied to the suction pad, and to be in a second state during release, in which the supply of negative pressure from the vacuum generator is blocked, forming a negative pressure trapping section between the three-port valve and the two-port valve and opening the inside of the suction pad to the atmosphere. During suction in the next transfer operation, the three-port valve is controlled to change from the second state to the first state, using both the negative pressure in the negative pressure trapping section and the negative pressure from the vacuum generator. This control valve mechanism makes it possible to minimize the number of port valves used.

[0009] The control valve mechanism may also include a first two-port valve and a second two-port valve provided on both sides of the rear piping section, and a third two-port valve provided in the front piping section. In this case, the first two-port valve and the second two-port valve are each open during suction and closed during release, forming a negative pressure trapping section between the first and second two-port valves. During suction in the next transfer operation, the first and second two-port valves are each open to supply the negative pressure in the negative pressure trapping section and the negative pressure from the vacuum generator to one or more suction pads. The third two-port valve is controlled to be in a first state during suction, during which negative pressure from the vacuum generator can be supplied to the suction pads, and in a second state during release, during which the inside of the suction pads is opened to the atmosphere, and to change from the second state to the first state by the time of suction in the next transfer operation. With this control valve mechanism, the presence of the third port valve enables suction and negative pressure trapping operations to be achieved without being affected by the time delay of the first and second two-port valves.

[0010] The transfer head may be provided with a plurality of suction pads, and the piping may include a plurality of branch pipes connected to the plurality of suction pads, respectively, and a single common pipe connecting the plurality of branch pipes to a vacuum generator. In this case, at least one of the plurality of branch pipes may be provided with an additional three-port valve that opens the interior of the at least one branch pipe to the atmosphere. In this way, the plurality of suction pads can be released individually.

[0011] The air pressure circuit for conveyance of the present invention can be applied to a molding remover. do. [Brief explanation of the drawings]

[0012] [Figure 1] 1 is a schematic diagram illustrating an example in which the air pressure circuit for conveyance according to the present embodiment is applied to a suction pad of a take-out head (conveyance head) of a molded product take-out machine. [Figure 2] 2 is a diagram showing the configuration of a specific example of a transfer air pressure circuit used in the embodiment of FIG. 1. FIG. [Figure 3] 3 is a diagram showing the operation of the air pressure circuit for conveyance in FIG. 2 and the change in the suction pressure of the suction pad over time in a first product take-out operation and a second product take-out operation. [Figure 4] 1A shows the change in suction pressure when a conventional pneumatic circuit for conveyance without a negative pressure trapping section is used, and FIG. 1B shows the change in suction pressure when the pneumatic circuit for conveyance of this embodiment with a negative pressure trapping section is used, with the time axes aligned. [Figure 5] FIG. 10 is a diagram showing the configuration of a specific example of a transfer air pressure circuit used in a second embodiment of the present invention. [Figure 6] 10A and 10B are diagrams showing the operation of the conveying air pressure circuit and the change in the suction pressure of the suction pad over time in the first product take-out operation and the second product take-out operation in the second embodiment. [Figure 7] FIG. 10 is a diagram used to explain a modified example. DETAILED DESCRIPTION OF THE INVENTION

[0013] DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS An embodiment of a conveying air pressure circuit and a control method thereof according to the present invention will be described in detail below with reference to the accompanying drawings.

[0014] (Embodiment 1) FIG. 1 is a schematic diagram of an example in which a conveying pneumatic circuit 1 according to this embodiment is applied to a suction pad 2 of a take-out head 3 (transport head) of a molded product take-out machine. The conveying pneumatic circuit 1 includes one or more suction pads 2 provided on the take-out head 3 (transport head) for transporting molded products as transported objects, a pipe 5 arranged between the one or more suction pads 2 and a vacuum generator 4, and a control valve mechanism 6 arranged in the path of the pipe 5. The control valve mechanism 6 includes a first two-port valve 7, a second two-port valve 8, and a third two-port valve 9, which will be described later. A negative pressure trapping section 10 is formed between the first two-port valve 7 and the second two-port valve 8. A pressure sensor 11 for measuring the negative pressure generated by the vacuum generator 4 is arranged in the portion of the pipe 5 between the first two-port valve 7 and the third two-port valve 9. The control device 12 has the function of issuing control commands to control the opening and closing of the first two-port valve 7, the second two-port valve 8, and the third two-port valve 9 based on the output of the pressure sensor 11, the function of issuing operation commands to the vacuum generating device 4 based on a predetermined operation sequence, and the function of issuing drive commands to the conveying mechanism 13 of the molded product removal machine, which moves the removal head 3 based on the predetermined operation sequence.

[0015] FIG. 2 is a diagram showing the configuration of a specific example of the transfer pneumatic circuit 1 used in the embodiment of FIG. 1. As specifically shown in FIG. 2, the vacuum generator 4 includes an intake port 4A, an exhaust port 4B, a supply port 4C that takes in positive pressure generated by a pump in the factory, and a two-port valve 4D consisting of a solenoid valve provided at the supply port 4C. A first two-port valve 7 is disposed in the piping portion near the intake port 4A of the vacuum generator 4, and a second two-port valve 8 is disposed in the piping portion near the suction pad 2. A third two-port valve 9 is disposed between the suction pad 2 and the second two-port valve 8. In this specification, the piping portion between the first two-port valve 7 and the second two-port valve 8 is referred to as the rear piping portion, and the piping portion from this rear piping portion to the suction pad 2 is referred to as the front piping portion. In this embodiment, the first two-port valve 7 (control valve), the second two-port valve 8 (control valve), and the third two-port valve 9 (control valve) form a control valve mechanism 6.

[0016] Each of the two-port valves 4D, 7, 8, and 9 has two ports, IN and OUT, and simply operates to close or open one path. In this embodiment, the first and second two-port valves 7 and 8 are controlled to be in an open state during suction and to be in a closed state during release. In this embodiment, the third two-port valve 9 is provided in a branch pipe 5A connected to the front piping portion. The third two-port valve 9 is controlled to be in a first state during suction, in which negative pressure from the vacuum generator 4 is supplied to the suction pad 2, and in a second state during release, in which the inside of the suction pad is opened to the atmosphere.

[0017] 2, the valve bodies of the two-port valves 4D, 7, and 8 are removed from the paths, leaving the paths open, and the valve body of the third two-port valve 9 closes the air-opening port of the branch pipe 5A, so that the air inside the pipe 5 is exhausted from the intake port 4A of the vacuum generator 4, creating negative pressure inside the pipe and the suction pad 2. In this specification, this state is referred to as a state in which the vacuum generator 4 "supplies negative pressure."

[0018] The molded product (transported product) is transported while being sucked by the suction pad 2. When the molded product (transported product) is released from the suction pad 2 at a predetermined transport position, the atmosphere release port is opened to open the inside of the suction pad 2 to the atmosphere (second state). Substantially simultaneously with the atmosphere release operation of the third two-port valve 9, the first two-port valve 7 and the second two-port valve 8 are closed, and the two-port valve 4D in the vacuum generator 4 is closed with its valve body to stop the supply of positive pressure to the vacuum generator 4. When the first and second two-port valves 7 and 8 are closed while negative pressure is being supplied from the vacuum generator 4 (first state), negative pressure is reliably trapped in the negative pressure trapping section 10 between the first two-port valve 7 and the second two-port valve 8. As will be explained in detail later, the negative pressure trapped in the negative pressure trapping section 10 is used in combination with the negative pressure supplied from the vacuum generator 4 during the suction operation of the next transport operation. That is, the negative pressure confined within the negative pressure confining section 10 is added to the negative pressure supplied from the vacuum generator, and the result is supplied to the suction pad 2. Therefore, according to this embodiment, part of the negative pressure generated during suction is stored in the negative pressure confining section 10, and during suction in the next transport operation, the negative pressure within the negative pressure confining section and the negative pressure from the vacuum generator 4 are used together, so the generated negative pressure is not wasted but is partially reused, thereby making it possible to reduce energy consumption compared to conventional methods.

[0019] Figure 3 shows the operation of the air pressure circuit for conveyance 1 shown in Figure 2 and the change in the suction pressure of the suction pad 2 over time during the first and second product removal operations. In Figure 3, a suction pressure sensor for measurement is placed near the suction pad 2 to ensure reliable data collection. To begin the suction operation, the vacuum generator 4 performs air suction while the suction pad 2 approaches the molded product. When the suction pad 2 comes into close contact with the molded product, suction begins and the suction pressure (negative pressure) increases. While suction is saturated (while the inside of the piping is almost vacuum), the take-out head moves to the release position. Once this movement is complete, a release command is output from the control device 12. When the release command is output, the first two-port valve 7 and the second two-port valve 8 are closed, the vacuum generator 4 stops operating, the third two-port valve 9 is opened, the suction pad 2 is opened to the atmosphere, and the release of the molded product is completed. The dashed line during the open period in FIG. 3 shows the change in suction pressure when a conventional pneumatic circuit for transfer is used, which does not use the first two-port valve 7, the second two-port valve 8, and the third two-port valve 9.

[0020] During the second product removal operation in Figure 3, the negative pressure trapped within the negative pressure trapping section 10 is also used, so negative pressure builds up in a short time. The dashed line at the start of the suction operation for the second product removal operation in Figure 3 shows the change in suction pressure when a conventional pneumatic circuit for conveyance without a negative pressure trapping section is used. Figure 4(A) shows the change in suction pressure when a conventional pneumatic circuit for conveyance without a negative pressure trapping section is used, and Figure 4(B) shows the change in suction pressure when the pneumatic circuit for conveyance of this embodiment, which has the negative pressure trapping section 10, is used, with the time axes aligned. As is clear from this figure, according to this embodiment, from the second product removal operation onwards, the time period until suction starts and the time period until release is completed are significantly shorter than in the conventional case.

[0021] (Embodiment 2) Fig. 5 is a diagram showing the configuration of a specific example of a transfer pneumatic circuit 1' used in a second embodiment of the present invention. The second embodiment differs from the transfer pneumatic circuit of the first embodiment shown in Fig. 2 in that the second embodiment does not include the second two-port valve 8 and uses a three-port valve 9' instead of the third two-port valve 9.

[0022] In this embodiment, the control valve mechanism 6 includes a three-port valve 9' provided in the front piping section and a two-port valve 7 provided in the rear piping section. The two-port valve 7 is controlled to be in an open state during suction and to be in a closed state during release. The three-port valve 9' of this control valve mechanism 6' is controlled to be in a first state during suction, in which negative pressure from the vacuum generator 4 is supplied to the suction pad 2, and to be in a second state during release, in which the supply of negative pressure from the vacuum generator 4 is blocked, a negative pressure trapping section 10 is formed between the three-port valve 9' and the two-port valve 7, and the inside of the suction pad 2 is opened to the atmosphere. Then, during suction in the next transfer operation, the three-port valve 9' is changed from the second state to the first state, in which the negative pressure in the negative pressure trapping section 10 and the negative pressure from the vacuum generator 4 are used in combination. This control valve mechanism 6' makes it possible to minimize the number of port valves used.

[0023] 6, like Fig. 3, shows the operation of the conveying air pressure circuit 1' and the change in the suction pressure of the suction pad 2 over time during the first product removal operation and the second product removal operation of the second embodiment. As can be seen from Fig. 6, the second embodiment also provides the same effects as the first embodiment.

[0024] (Variation) 7 shows a modified example in which a plurality of suction pads 21, 22 are provided on the take-out head (transport head). In the modified example shown in FIG. 7, a plurality of suction pads 21, 22 are provided, and the piping includes a plurality of branch pipes 51, 52 connected to the plurality of suction pads 21, 22, respectively, and a single common pipe 5 connecting the plurality of branch pipes 51, 52 to the vacuum generator 4. In addition, in this modified example, a pressure sensor 11 that detects the pressure inside the pipe 5 during suction is disposed closer to the suction pad than the three-port valve 9'. At least one branch pipe 51 of the plurality of branch pipes is provided with an additional three-port valve 14 that opens the inside of this branch pipe 51 to the atmosphere. In this manner, the plurality of suction pads 21, 22 can be released individually. [Industrial Applicability]

[0025] According to the present invention, a portion of the negative pressure generated during suction is stored in the negative pressure containment section, and during suction in the next transport operation, the negative pressure in the negative pressure containment section and the negative pressure from the vacuum generating device are used in combination.This means that the generated negative pressure is not wasted but is partially reused, thereby reducing energy consumption compared to conventional methods. [Explanation of symbols]

[0026] 1. Air pressure circuit for conveyance 2,21,22 Suction pad 3. Removal head (transport head) 4. Vacuum generator 4D 2-port valve 5 Piping 6. Control valve mechanism 7 First 2-port valve 8 Second 2-port valve 9 Third 2-port valve 9´ 3-port valve 10 Negative pressure containment section 11 Pressure Sensor 12 Control device 13 Conveyor mechanism 14 3-port valve 51,52 Branch piping

Claims

1. one or more suction pads provided on the transport head for transporting the transported object; a pipe disposed between the one or more suction pads and a vacuum generator; a control valve mechanism having two or more control valves that is arranged in the path of the piping, and that supplies negative pressure from the vacuum generator to the one or more suction pads when the transported product is suctioned by the one or more suction pads, and that opens the inside of the suction pads to the atmosphere when the transported product is released from the one or more suction pads, and that forms a negative pressure confining section in which the negative pressure is confined in a rear piping section that is closer to the vacuum generator than the front piping section of the piping, and that uses both the negative pressure in the negative pressure confining section and the negative pressure from the vacuum generator when the next transport operation is suctioned.

2. the control valve mechanism includes a three-port valve provided in the front piping portion and a two-port valve provided in the rear piping portion, the two-port valve is controlled to be in an open state during the adsorption and to be in a closed state during the release, 2. The pneumatic circuit for conveying according to claim 1, wherein said three-port valve is controlled so that, during the suction operation, it is in a first state where the negative pressure from said vacuum generator is supplied to said suction pad, and during the release operation, it is in a second state where the supply of negative pressure from said vacuum generator is blocked to form a negative pressure confining section between said three-port valve and said two-port valve and the inside of said suction pad is opened to the atmosphere, and during the suction operation of the next conveying operation, it is controlled to change from the second state to the first state so that the negative pressure in said negative pressure confining section and the negative pressure from said vacuum generator are used in combination.

3. the control valve mechanism includes a first two-port valve and a second two-port valve provided on both sides of the rear piping portion, and a third two-port valve provided in the front piping portion; the first two-port valve and the second two-port valve are each in an open state during the suction and in a closed state during the release, thereby forming the negative pressure trapping section between the first two-port valve and the second two-port valve, and are each in an open state during suction in the next transfer operation, thereby supplying the negative pressure in the negative pressure trapping section and the negative pressure from the vacuum generating device to the one or more suction pads; 2. The pneumatic circuit for conveying according to claim 1, wherein said third two-port valve is controlled to be in a first state in which said negative pressure from said vacuum generator can be supplied to said suction pads during said suction, and to be in a second state in which said suction pads are opened to the atmosphere during said release, so as to change from said second state to said first state by the time of suction for the next conveying operation.

4. The transport head is provided with a plurality of the suction pads, the piping includes a plurality of branch pipes connected to the plurality of suction pads, respectively, and one common pipe connecting the plurality of branch pipes to the vacuum generating device, 4. The pneumatic circuit for transfer according to claim 2, wherein at least one of said plurality of branch pipes is provided with an additional three-port valve for opening the interior of said at least one branch pipe to the atmosphere.

5. A molded product remover comprising the conveying air pressure circuit according to any one of claims 1 to 4.

6. one or more suction pads provided on the transport head for transporting the transported object; a pipe disposed between the one or more suction pads and a vacuum generator; a control method for a pneumatic circuit for conveyance, the control valve mechanism having two or more control valves that are arranged in a path of the piping, and that supply negative pressure from the vacuum generating device to the one or more suction pads when the conveyed workpiece is suctioned by the one or more suction pads, and that open the inside of the suction pads to the atmosphere when the conveyed workpiece is released from the one or more suction pads, the control valve mechanism controls the two or more control valves so that, when released, a negative pressure confinement portion in which the negative pressure is confined is formed in a rear piping portion that is located closer to the vacuum generating device than a front piping portion of the piping, a control method for a conveying air pressure circuit for controlling the two or more control valves so that, during suction in the next conveying operation, the negative pressure in the negative pressure confinement section and the negative pressure from the vacuum generating device are supplied to the one or more suction pads;

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