Air pressure circuit for conveying

Abstract

To provide an air pressure circuit for conveyance capable of reducing energy consumption by utilizing a generated negative pressure more effectively than before. [Solution] 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, and 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 in which negative pressure from a vacuum generator 4 is supplied to a suction pad 2 during suction, and to be in a second state in which the supply of negative pressure from the vacuum generator 4 is blocked, a negative pressure confining 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 during release. During suction in the next transfer operation, the control valve mechanism 6' is controlled to change from the second state to the first state and to use both the negative pressure in the negative pressure confining section 10 and the negative pressure from the vacuum generator 4.

Description

[Technical field]

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

[0002] Japanese Patent No. 4653984 discloses a molded product removal device having a transfer air pressure circuit equipped with one or more suction pads provided on a chuck (transport head) for transferring 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 retention 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 to reach just the suction pressure when the chuck reaches the removal position. Therefore, compared to a system in which negative pressure is generated in the chuck in advance from a 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 with a conventional device, the negative pressure maintaining valve and vacuum generator are opened to expose the inside of the pipe to the atmosphere, consuming all the negative pressure in the pipe. Then, when the next suction operation is performed, the inside of the pipe is again placed in a negative pressure state. Thus, conventionally, a lot of energy is consumed to create a negative pressure state in the pipe each time. The longer the length of the pipe, the greater the energy consumption.

[0005] An object of the present invention is to provide an air pressure circuit for conveyance which can utilize the generated negative pressure more effectively than in the past and reduce the amount of energy consumption. [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 path of the piping, which supplies 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 which opens the inside of the suction pads to the atmosphere and forms a negative pressure confinement section in which negative pressure is confined in a rear piping section which is located closer to the vacuum generator than the front piping section of the piping, and which is arranged to use both the negative pressure in the negative pressure confinement section and the negative pressure from the vacuum generator when the next transport operation is suctioned.

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

[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 be open during suction and closed 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 in a second state during release in which the supply of negative pressure from the vacuum generator is blocked to form a negative pressure trapping section between the two-port valve and the suction pad and to open the inside of the suction pad to the atmosphere, and is controlled to change from the second state to the first state during suction in the next transfer operation, so that the negative pressure in the negative pressure trapping section and the negative pressure from the vacuum generator are used in combination. 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 in an open state during suction and in a closed state during release to form a 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 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 so that the negative pressure from the vacuum generator can be supplied to the suction pads, and in a second state during release to open the inside of the suction pad to the atmosphere, and to change from the second state to the first state by the time of suction in the next transfer operation. According to this control valve mechanism, the presence of the third port valve makes it possible to realize the suction operation and the negative pressure trapping operation without being affected by the time delay of the operations 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 one 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 conveying air pressure circuit of the present invention can be applied to a molding remover. do. [Brief description of the drawings]

[0012] [Figure 1] 1 is a schematic diagram illustrating an example in which the conveying pneumatic circuit of the present embodiment is applied to a suction pad of a removal head (transport head) of a molded product removal machine. FIG. [Diagram 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. [Diagram 3] 3 is a diagram showing the operation of the conveying air pressure circuit 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. FIG. [Figure 4] 1A shows the change in suction pressure when a conventional pneumatic circuit for transport without a negative pressure trapping section is used, and FIG. 1B shows the change in suction pressure when the pneumatic circuit for transport of this embodiment with a negative pressure trapping section is used, with the time axes aligned. [Diagram 5] FIG. 11 is a diagram showing the configuration of a specific example of a transfer air pressure circuit used in the second embodiment of the present invention. [Figure 6] 13A to 13C are diagrams showing changes over time in the operation of the conveying air pressure circuit and the suction pressure of the suction pads in a first product take-out operation and a second product take-out operation in the second embodiment. [Figure 7] FIG. 13 is a diagram used to explain a modified example. DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS

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

[0014] (Embodiment 1) FIG. 1 is a schematic diagram of an example in which the pneumatic circuit for conveyance 1 of this embodiment is applied to a suction pad 2 of a take-out head 3 (conveyor head) of a molded product take-out machine. The pneumatic circuit for conveyance 1 includes one or more suction pads 2 provided on the take-out head 3 (conveyor head) for conveying molded products as conveyed products, 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 part of the pipe 5 between the first two-port valve 7 and the third two-port valve 9. The control device 12 has a 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, a function of issuing operation commands to the vacuum generating device 4 based on a predetermined operation sequence, and a 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 pneumatic circuit for conveyance 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 for taking in a positive pressure generated by a pump in a factory, and a two-port valve 4D consisting of an electromagnetic valve provided at the supply port 4C. A first two-port valve 7 is disposed in a piping portion close to the intake port 4A of the vacuum generator 4, and a second two-port valve 8 is disposed in a piping portion close to 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 a rear piping portion, and the piping portion from this rear piping portion to the suction pad 2 is referred to as a 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] The two-port valves 4D, 7, 8 and 9 each have two ports, IN and OUT, and simply operate to close or open one path. In this embodiment, the first and second two-port valves 7 and 8 are controlled to be open during suction and closed 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 in which negative pressure from the vacuum generator 4 is supplied to the suction pad 2 during suction and in a second state in which the inside of the suction pad is opened to the atmosphere during release.

[0017] 2, the valve bodies of the two-port valves 4D, 7, and 8 are removed from the paths to open the paths, and the valve body of the third two-port valve 9 closes the atmospheric opening 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 opening port is opened to open the inside of the suction pad 2 to the atmosphere (second state). Substantially simultaneously with the atmosphere opening 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 by a 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 in a state in which negative pressure is supplied from the vacuum generator 4 (first state), the 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 described in detail later, the negative pressure trapped in the negative pressure trapping section 10 is used together with the negative pressure supplied from the vacuum generator 4 during the suction of the next transport operation. That is, the negative pressure contained within the negative pressure containment unit 10 is added to the negative pressure supplied from the vacuum generator, and the resultant is supplied to the suction pad 2. Therefore, according to this embodiment, a portion of the negative pressure generated during suction is stored in the negative pressure containment unit 10, and the negative pressure within the negative pressure containment unit and the negative pressure from the vacuum generator 4 are used together during suction in the next transport operation, so that the generated negative pressure is not wasted but is partially reused, thereby making it possible to reduce energy consumption compared to the conventional method.

[0019] FIG. 3 shows the operation of the air pressure circuit 1 for conveyance in FIG. 2 and the change in the suction pressure of the suction pad 2 over time in the first product removal operation and the second product removal operation. In FIG. 3, a suction pressure sensor for measurement is placed near the suction pad 2 in order to reliably collect data. First, to start the suction operation, the suction pad 2 is brought close to the molded product while the vacuum generator 4 performs air suction. When the suction pad 2 comes into close contact with the molded product, suction begins and the suction pressure (negative pressure) rises. While the suction is saturated (while the inside of the piping is in an almost vacuum state), the take-out head moves to the release position, and when the movement is completed, 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 path of the third two-port valve 9 is opened, the inside of 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 indicates 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 Fig. 3, the negative pressure trapped in the negative pressure trapping section 10 is also used, so the negative pressure rises in a short time. The broken line at the start of the suction operation of the second product removal operation in Fig. 3 indicates the change in suction pressure when a conventional pneumatic circuit for conveyance without a negative pressure trapping section is used. Fig. 4(A) shows the change in suction pressure when a conventional pneumatic circuit for conveyance without a negative pressure trapping section is used, and Fig. 4(B) shows the change in suction pressure when the pneumatic circuit for conveyance of this embodiment having the negative pressure trapping section 10 is used, with the time axes aligned. As is clear from this figure, according to this embodiment, the time period until suction starts and the time period until release is completed are significantly shorter than in the past after the second product removal operation.

[0021] (Embodiment 2) Fig. 5 is a diagram showing the configuration of a specific example of the pneumatic circuit for transfer 1' used in the second embodiment of the present invention. The second embodiment differs from the first embodiment in that there is no second two-port valve 8 and a three-port valve 9' is used instead of the third two-port valve 9, as compared with the pneumatic circuit for transfer of the first embodiment shown in Fig. 2.

[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 where negative pressure from the vacuum generator 4 is supplied to the suction pad 2, and to be in a second state during release where the supply of negative pressure from the vacuum generator 4 is blocked, a negative pressure confining section 10 is formed between the two-port valve 7 and the control valve mechanism 6', and the inside of the suction pad 2 is opened to the atmosphere. During suction in the next transfer operation, the control valve mechanism 6' is controlled to change from the second state to the first state, and to use both the negative pressure in the negative pressure confining section 10 and the negative pressure from the vacuum generator 4. According to this control valve mechanism 6', the number of port valves used can be minimized.

[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 in the first product removal operation and the second product removal operation in the second embodiment. As can be seen from Fig. 6, the second embodiment also provides the same effects as the first embodiment.

[0024] (Modification) FIG. 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 one common pipe 5 connecting the plurality of branch pipes 51, 52 to the vacuum generating device 4. In addition, in the modified example, a pressure sensor 11 for detecting the pressure in 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 for opening the inside of the 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 the negative pressure in the negative pressure containment section and the negative pressure from the vacuum generating device are used together during suction in the next transport operation. This means that the generated negative pressure is not wasted but is partially reused, thereby reducing energy consumption compared to the conventional method. [Explanation of symbols]

[0026] 1. Air pressure circuit for conveying 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 a conveying head for conveying a conveyed product; a piping disposed between the one or more suction pads and a vacuum generating device; a control valve mechanism having two or more control valves arranged in a path of the piping, for supplying 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, for opening the inside of the suction pads to the atmosphere when the transported product is released from the one or more suction pads, and for forming a negative pressure confining section in which the negative pressure is confined in a rear piping section which is located closer to the vacuum generator than a front piping section of the piping, and for using 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, 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, The three-port valve is controlled so that, during the suction operation, it is in a first state in which it supplies the negative pressure from the vacuum generator to the suction pad, and, during the release, it is in a second state in which it blocks the supply of negative pressure from the vacuum generator, forms the negative pressure confining section between the three-port valve and the two-port valve, and opens the inside of the suction pad to the atmosphere, and is controlled to change from the second state to the first state during the suction operation of the next transport operation, so as to use both the negative pressure in the negative pressure confining section and the negative pressure from the vacuum generator.

2. One or more suction pads provided on a conveying head for conveying a conveyed product; a piping disposed between the one or more suction pads and a vacuum generating device; a control valve mechanism having two or more control valves arranged in a path of the piping, for supplying 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, for opening the inside of the suction pads to the atmosphere when the transported product is released from the one or more suction pads, and for forming a negative pressure confining section in which the negative pressure is confined in a rear piping section which is located closer to the vacuum generator than a front piping section of the piping, and for using 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, the control valve mechanism includes a first two-port valve and a second two-port valve provided on either side 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 are each in a closed state during the release to form the negative pressure trapping portion between the first two-port valve and the second two-port valve, and when the next transport operation is suctioned, the first two-port valve and the second two-port valve are each in an open state to supply the negative pressure in the negative pressure trapping portion and the negative pressure from the vacuum generating device to the one or more suction pads, The third two-port valve is controlled to be in a first state in which the negative pressure from the vacuum generator can be supplied to the suction pad during the suction, and to be in a second state in which the inside of the suction pad is opened to the atmosphere during the release, and to be changed from the second state to the first state by the time of suction for the next conveying operation.

3. 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, 3. The pneumatic circuit for transfer according to claim 1, 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.

4. A molded product remover comprising the conveying air pressure circuit according to claim 1 or 2.

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