Robot suction device

Abstract

[Problem] To be able to easily change the duration time of at least one state among a suction state and a suction release state on site in a suction device for a robot that is used by being attached to a robot arm. [Solution] This suction device 10 for a robot comprises a suction pad 16 and a timer 18. The timer 18 is configured so as to switch between a suction state in which a vacuum suction force is generated in the suction pad 16 by means of a vacuum pump 52 disposed inside a casing 32 and a suction release state in which the vacuum suction force is not generated in the suction pad 16. The timer 18 has a knob part 62 for setting and changing the duration time of the suction state. When the duration time set with the timer 18 elapses, the suction device 10 for a robot switches from the suction state to the suction release state.

Description

[Technical Field]

[0001] The present invention relates to a robot suction device that is attached to a robot arm and used, and more specifically to a robot suction device that vacuum-sucks and transports a workpiece to be transported. [Background technology]

[0002] When using a robot to transport a workpiece, the workpiece is vacuum-sucked by a robot arm equipped with a suction device and transported from a predetermined position to another position (Patent Document 1). [Prior art documents] [Patent documents]

[0003] [Patent Document 1] Patent Publication No. 2021-122872 Summary of the Invention [Problem to be solved by the invention]

[0004] Typically, the timing of suction and release in such a suction device is controlled by a control program implemented in the robot arm or an external control device that controls it. The timing of suction and release may be controlled based on the position of the robot arm or the output of various sensors attached to the robot arm. Alternatively, a simpler method is to control it based on time. For example, the timing of starting suction may be determined based on the position information of the robot arm, and suction may be released after a predetermined time has elapsed since suction. The duration of the suction state is determined in advance, taking into account the time required for the robot arm to move to a predetermined position after suctioning the target workpiece, and this time is preset in the control program. However, when a robot is introduced to a production site, the timing of release may need to be fine-tuned, or the timing of release may need to be changed due to changes in the target workpiece or the transport path. To change the timing of release, the control program must be modified each time. However, such program modification work is difficult or virtually impossible for workers unfamiliar with programming, and even if program modification is possible, it may be cumbersome to perform in a production site.

[0005] Therefore, an object of the present invention is to provide a robot suction device that is attached to a robot arm and used, and that makes it possible to easily change the duration of at least one of the suction state and the suction release state on site. [Means for solving the problem]

[0006] That is, the present invention provides: A suction device for a robot that is attached to a robot arm and used, a suction unit connected to a vacuum source and configured to suction and hold a workpiece to be transported; a timer for switching between an adsorption state in which a vacuum adsorption force by the vacuum source is applied to the adsorption portion and an adsorption release state in which the vacuum adsorption force is not applied to the adsorption portion, the timer being capable of setting a duration of at least one of the adsorption state and the adsorption release state and having a manual operation unit for setting or changing the duration; Equipped with The suction device for a robot is configured to switch from the one state to the other state when the duration set by the timer has elapsed.

[0007] In this robot suction device, the duration of at least one of the suction state and the suction release state can be changed by operating the manual operation unit of the timer. This eliminates the need to change the control program to change the duration, as in conventional devices, and makes it possible to easily change the duration on site.

[0008] The timer may be configured to set a duration for the adsorption state, and the adsorption state may be switched to the adsorption release state after the duration has elapsed.

[0009] Furthermore, the vacuum source may be a vacuum pump built into the robot suction device.

[0010] Furthermore, a communication unit for communicating with an external control device; a mode selection means for selecting between an internal control mode and an external control mode; Furthermore, When the internal control mode is selected, the duration can be set by the timer, and when the external control mode is selected, the duration can be set based on a command from an external control device that is communicatively connected to the communication unit.

[0011] Furthermore, an arm fixing part adapted to be fixed to a robot arm; a frame attached to the arm fixing portion; a casing that covers at least a portion of the frame; a shaft-shaped member extending in a vertical direction from an upper end supported by the frame within the casing to a lower end located outside the casing, the suction unit being provided at the lower end, and a passage forming a part of a flow path between the suction unit and the vacuum source being formed inside the shaft-shaped member; Equipped with A downward load applied to the suction portion can be supported by the arm fixing portion via the shaft member and the frame.

[0012] With this configuration, the downward load applied to the suction part by the workpiece being suction-held by the suction part can be supported by the arm fixing part without being applied to the casing, eliminating the need for a high-strength casing structure.

[0013] DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS An embodiment of a robot suction device according to the present invention will now be described with reference to the accompanying drawings. [Brief explanation of the drawings]

[0014] [Figure 1] 1 is a front view of the appearance of a suction device for a robot according to an embodiment of the present invention; [Figure 2] FIG. 2 is an external side view of the suction device for a robot shown in FIG. 1. [Figure 3] 2 is a front view showing the internal structure of the robot suction device of FIG. 1. [Figure 4] 2 is a side view showing the internal structure of the robot suction device of FIG. 1. [Figure 5] 2 is a schematic diagram showing a flow path structure of the robot suction device of FIG. 1. FIG. DETAILED DESCRIPTION OF THE INVENTION

[0015] 1 to 4, a robot suction device 10 according to one embodiment of the present invention comprises a main body 12, an arm fixing part 14 located on top of the main body 12 and fixed to a robot arm, and a suction pad (suction part) 16 located in a position protruding downward from under the main body 12. As will be described later, when the suction pad 16 is pressed against a workpiece to be transported and displaced upward relative to the main body 12, negative pressure is generated in the suction pad 16, thereby suction-holding the workpiece to be transported, and when a preset duration has elapsed since suction began, the negative pressure is released, thereby releasing the suction-holding of the workpiece to be transported.

[0016] As shown in Fig. 1, a timer 18, a pressure display monitor 20, and an error lamp 22 are arranged on the front of the main body 12. As shown in Fig. 2, a regulator 24, a mode selection switch (mode selection means) 26, and a communication cable connector (communication unit) 28 for connecting to an external control device are arranged on the side of the main body 12. Furthermore, a main power switch 30 for the robot suction device 10 is arranged on the bottom surface of the main body 12.

[0017] As shown in FIGS. 3 and 4, a frame 34 attached to the arm fixing portion 14 and a shaft-shaped member 36 supported by the frame 34 are disposed within the casing 32 of the main body 12. The frame 34 comprises four support members 38 extending downward from the arm fixing portion 14 and a plate-shaped member 40 fixed to the support members 38 and extending horizontally. The shaft-shaped member 36 is attached to the plate-shaped member 40 of the frame 34 so as to be movable up and down. The shaft-shaped member 36 extends vertically from an upper end 36a supported by the frame 34 to a lower end 36b located outside the casing 32, and a suction pad 16 is detachably attached to the lower end 36b. The upper end 36a of the shaft-shaped member 36 is provided with a tube connection portion 42 to which a tube 56 (see FIG. 5) can be attached, and a passage 36c (FIG. 5) extending from the tube connection portion 42 to the lower end 36b is formed within the shaft-shaped member 36. The shaft-shaped member 36 is biased downward by a spring 44, and when the suction pad 16 is pressed against the workpiece, it moves upward while compressing the spring 44. A microswitch 48 having a lever 46 is also disposed within the casing 32. The lever 46 of the microswitch 48 is positioned to engage with a switch engaging portion 50 of the shaft-shaped member 36. When the shaft-shaped member 36 is in the bottom end position shown in the figure, the lever 46 of the microswitch 48 engages with the switch engaging portion 50 of the shaft-shaped member 36 and is pressed in, and the microswitch 48 is in the OFF state. When the shaft-shaped member 36 moves upward, it disengages from the switch engaging portion 50, the lever 46 is released, and the microswitch 48 is turned on. The robot suction device 10 is configured to be in a suction state when the suction pad 16 is pressed against the workpiece to be transported and the microswitch 48 is turned on.

[0018] A vacuum pump (vacuum source) 52 and a solenoid valve 54 are also disposed within the casing 32 of the main body 12. As shown in FIG. 5, the vacuum pump 52 is fluidly connected to a passage 36c of the shaft-shaped member 36 via a tube 56 (omitted in FIGS. 3 and 4). The passage 36c constitutes a part of a flow path 58 extending via the tube 56 between the suction pad 16 and the vacuum pump 52. The solenoid valve 54 is connected to the flow path 58 between the vacuum pump 52 and the shaft-shaped member 36, and when opened, opens the flow path 58 between the vacuum pump 52 and the shaft-shaped member 36 to the atmosphere. A pressure sensor 60 is also connected to the flow path 58. The pressure sensor 60 measures the pressure within the flow path 58, and the pressure value is displayed on the pressure display monitor 20. The regulator 24 adjusts the pressure within the flow path 58 generated by the vacuum pump 52. The magnitude of the pressure adjusted by the regulator 24 can be changed by operating a knob exposed to the outside of the main body 12.

[0019] In the robot suction device 10, when the suction pad 16 is pushed upward and the microswitch 48 is turned ON, the suction pad 16 is placed in a suction state where a vacuum suction force is generated, and when a preset duration has elapsed since the suction state, the device enters a suction-release state where no vacuum suction force is generated. More specifically, when the microswitch 48 is turned ON, the solenoid valve 54 is closed and the vacuum pump 52 is started, generating a vacuum suction force on the suction pad 16 through the passage 36c of the shaft-shaped member 36. After the preset duration has elapsed, the vacuum pump 52 stops and the solenoid valve 54 is opened, opening the flow path 58 to the atmosphere. This increases the pressure in the flow path 58 to atmospheric pressure, quickly releasing the vacuum suction force of the suction pad 16. Note that an upper limit vacuum pressure and a lower limit vacuum pressure during the suction state can be set by operating the pressure display monitor 20. If the pressure value measured by the pressure sensor during the suction state exceeds the upper limit vacuum pressure, the vacuum pump 52 is temporarily stopped, and if the pressure value falls below the lower limit vacuum pressure, the vacuum pump 52 is started again. This allows the vacuum suction force generated in the suction pad 16 to be maintained within a certain range. Note that the above-mentioned regulator 24 can also be used to adjust the vacuum pressure so that it does not exceed a certain level.

[0020] In the robot suction device 10, the mode selection switch 26 allows selection between internal control mode and external control mode. When the internal control mode is selected, the duration of the suction state is set to a value set by the timer 18. The timer 18 has a knob (manual operation unit) 62 arranged so as to be operable from the outside, and the duration can be changed to any value by operating this knob 62. When the external control mode is selected, the setting of the timer 18 is ignored, and the duration is set by a command from an external control device connected by a communication cable. Note that the communication connection with the external control device may be established by other methods, such as wireless communication.

[0021] If the pressure measured by the pressure sensor does not drop below the predetermined normal operating pressure value even after a predetermined time has passed since the suction state was established, it is determined that the workpiece to be transported is not properly suctioned to the suction pad 16, and the transport operation by the robot arm is stopped, and the error lamp 22 is turned on to notify the user of this condition.

[0022] When a workpiece to be transported is sucked and held by the suction pad 16 in the suction state, the downward load applied to the suction pad 16 is not applied to the casing 32, but is supported by the arm fixing part 14 via the shaft member 36 and frame 34. In this embodiment, the casing 32 is made of a resin that is not very strong, and the shaft member 36, frame 34, and arm fixing part 14 are made of a metal that is strong. Therefore, even when a relatively heavy workpiece to be transported is sucked and held, the load is applied only to the strong members, making it possible to hold the workpiece to be transported in a stable state.

[0023] In the robot suction device 10, the duration of the suction state can be set by operating the knob 62 of the timer 18 provided on the main body 12, so it is possible to easily change the timing of switching from the suction state to the suction release state without changing the control program as in the past. In the above embodiment, the duration of the suction state is set by the timer 18, but it is also possible to set the duration of the suction release state.

[0024] Although the above describes an embodiment of the present invention, the present invention is not limited to this embodiment. For example, the vacuum pump may not be provided in the main body, but may be connected to an external vacuum source via a tube or the like. In this case, for example, a solenoid valve may be used to fluidly connect the suction pad to the external vacuum source in the suction state, and to shut off the suction pad from the external vacuum source and open the flow path on the suction pad side to the atmosphere in the suction-released state. In the above embodiment, a microswitch detects that the suction pad has been pushed toward the main body to initiate the suction state. However, the suction state or the suction-released state may also be initiated based on an optical sensor such as a camera detecting that the robot suction device has reached a predetermined position, or an encoder or the like at each joint of the robot arm detecting that the robot arm has reached a predetermined coordinate. Furthermore, the manual operation unit for setting and changing the duration of the timer is not limited to a knob, and various types, such as a button operation or a touch panel, may be used. [Explanation of symbols]

[0025] 10. Robot suction device 12 Main body 14 Arm fixing part 16. Suction pad (suction part) 18 Timer 20 Pressure display monitor 22 Error lamp 24 Regulator 26 Mode selection switch (mode selection means) 28 Communication cable connector (communication section) 30 Main power switch 32 Casing 34 frames 36 Shaft-shaped member 36a Upper end 36b Bottom end 36c aisle 38 Support member 40 Plate-shaped member 42 Tube connection 44 Spring 46 Lever 48 Microswitch 50 Switch engagement part 52 Vacuum pump (vacuum source) 54 Solenoid valve 56 tubes 58 Flow path 60 Pressure Sensor 62 Knob (manual operation part)

Claims

1. A suction device for a robot that is attached to a robot arm and used, an arm fixing part adapted to be fixed to a robot arm; a main body attached to the arm fixing portion; an adsorption unit disposed at a position protruding from the main body, the adsorption unit being connected to a vacuum source and adapted to adsorb and hold a workpiece to be transported; a timer that is disposed on the main body and switches between an adsorption state in which a vacuum adsorption force from the vacuum source is applied to the adsorption portion and an adsorption release state in which the vacuum adsorption force is not applied to the adsorption portion, the timer being capable of setting a duration of at least one of the adsorption state and the adsorption release state, and having a manual operation unit for setting or changing the duration, the manual operation unit being disposed so as to be operable from outside the main body; Equipped with The suction device for a robot is configured to switch from the one state to the other state when the duration set by the timer has elapsed.

2. 2. The suction device for a robot according to claim 1, wherein the timer is configured to set a duration of the suction state, and the suction state is switched to the suction release state after the lapse of the duration.

3. 2. The robot suction device according to claim 1, wherein the vacuum source is a vacuum pump built into the robot suction device.

4. a communication unit for communicating with an external control device; a mode selection means for selecting between an internal control mode and an external control mode; Furthermore, 2. The suction device for a robot according to claim 1, wherein the duration is set by the timer when the internal control mode is selected, and the duration is set based on a command from an external control device communicatively connected to the communication unit when the external control mode is selected.

5. A frame attached to the arm fixing portion; a casing that covers at least a portion of the frame; a shaft-shaped member extending in a vertical direction from an upper end supported by the frame within the casing to a lower end located outside the casing, the suction unit being provided at the lower end, and a passage forming a part of a flow path between the suction unit and the vacuum source being formed inside the shaft-shaped member; Equipped with 5. The suction device for a robot according to claim 1, wherein a downward load applied to the suction portion is supported by the arm fixing portion via the shaft member and the frame.

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