JPS6363359B2 - - Google Patents

Description

[Detailed Description of the Invention] [Industrial Application Field] The present invention relates to a handling device installed on a robot arm, and more specifically, it is used for gripping workpieces stacked on a pallet and transferring them to another location, or for handling workpieces stacked on a pallet. The present invention relates to an improvement in a handling device suitable for use in a workpiece handling operation when the height position of a workpiece gripping or releasing operation constantly changes, such as when workpieces are stacked on top of each other.

When the handling device installed on the robot arm grasps the workpieces stacked on the pallet one after another and moves them to another location, or when the workpieces are stacked one after another on the pallet, the height of the workpiece gripping or releasing operation on the pallet is increased. Since the holding position changes one after another, a handling device is required that can easily control the workpiece gripping operation position and the workpiece release operation position. Furthermore, when a workpiece whose position is fixed is to be gripped by a handling device, it is necessary to ensure that the gripping operation can be performed smoothly even if the relative position of the workpiece and the handling device is slightly shifted. Furthermore, when transferring a workpiece gripped by a handling device to a jig on a pallet or a mounting section of a machine tool, the handling device can smoothly transfer the workpiece even if the relative position of the jig, mounting section, etc. and the workpiece is slightly shifted. It is necessary to be able to transfer the workpiece from there to the jig, mounting section, etc. However, in order to improve the positional accuracy when moving a workpiece by a robot, it is necessary that the workpiece be correctly positioned with respect to the robot arm when the workpiece is gripped by a handling device.

[Conventional technology]

Japanese Utility Model Publication No. 49-30211 discloses a handling device for handling work when the height position of a work gripping operation or a release operation changes one after another. This conventional handling device includes a base member that is linearly driven forward and backward by a cylinder device attached to a robot arm, and a base member that is movable in the forward and backward movement direction with respect to the base member and that is attached in front of the base member with a spring. a support member that is biased, a workpiece gripping claw attached to the support member, a claw actuator for gripping and releasing the workpiece gripping claw, and a limit switch for detecting displacement of the support member with respect to the base member. It is equipped with According to this conventional handling device, when the workpiece gripping claw or the support member contacts the workpiece to be gripped, or when the workpiece gripped by the workpiece gripping claw contacts the surface to be placed. Since the relative displacement between the base member and the support member that occurs can be detected by a limit switch and the forward movement of the base member by the cylinder device can be stopped, the height position of the workpiece gripping or releasing operation can be easily controlled. can.

[Problem that the invention seeks to solve]

However, in the above-mentioned conventional handling device, the piston member provided on the support member that supports the workpiece gripping claw is always movable or not always movable in the radial direction with respect to the cylinder member provided on the base member. Because they are mated,
If the piston member is always movable in the radial direction with respect to the cylinder member of the base member, the workpiece gripped by the handling device cannot be correctly positioned with respect to the robot arm, resulting in a decrease in positional accuracy when moving the workpiece by the robot. The problem arises.

On the other hand, if the piston member cannot always move freely in the radial direction with respect to the cylinder member of the base member, the workpiece to be gripped may be fixedly held at a position shifted from a predetermined position, or the workpiece may be gripped by a handling device. When a jig, a mounting portion, etc. for holding a workpiece are deviated from a predetermined position, a problem arises in that the workpiece gripping operation and release operation cannot be performed smoothly.

Therefore, an object of the present invention is to be able to perform handling work with simple control when the height position of the workpiece gripping operation and release operation is constantly changing, and moreover, to prevent the workpiece to be gripped from a predetermined position. Smooth workpiece gripping and workpiece release operations even when the workpiece is held fixed in position, or when the jig, attachment part, etc. for holding the workpiece gripped by the handling device is displaced from the predetermined position. It is an object of the present invention to provide a handling device which can prevent a decrease in positional accuracy when moving a workpiece by a robot arm.

[Means for solving problems]

According to the present invention, the base member, which is linearly driven forward and backward by the cylinder device provided at the tip of the lock arm, is provided with a cylinder portion extending through the base member in the forward and backward movement direction, and the workpiece grip located in front of the cylinder portion is provided. A piston member supporting a workpiece gripping claw and a claw actuator for gripping and releasing the workpiece gripping claw is fitted into the cylinder portion so as to be movable in the direction of forward and backward movement relative to the base member, and a piston member is provided between the base member and the piston member. A spring provided at the base member urges the piston member forward of the base member, and the spring force allows a stopper flange provided at the rear end of the piston member to come into contact with the rear end surface of the base member, and the base member and the piston member A switch means is provided between the piston member and the stopper flange for detecting that the stopper flange of the piston member is separated from the rear end surface of the base member by a predetermined distance rearwardly, and the cylinder member is provided at intervals in the axial direction on the inner surface of the cylinder member. A pair of inner circumferential flanges with a smaller diameter than the piston member and a larger diameter than the piston member are provided,
A stopper flange is provided on the outer circumference of the piston member, and when the stopper flange is in contact with the rear end surface of the base member, the stopper flange is closely fitted to the inner circumferential flange to restrict the movement of the piston member in the radial direction with respect to the base member. A pair of outer circumferential flanges are provided, which detach from the inner circumferential flanges when the base member moves backward by a predetermined amount from the rear end surface of the base member to allow the piston member to move radially relative to the base member. A handling device is provided in which the amount of movement of the piston member until it separates from the inner circumferential flange is set to be smaller than the amount of movement of the piston member until the switch means detects the piston member.

[Effect]

When gripping a workpiece with the handling device according to the present invention, when the piston member is advanced together with the base member by the cylinder device and the piston member or the workpiece gripping claw comes into contact with the workpiece, the piston member stops at that position. The member is displaced against the spring force in a direction in which the stopper flange moves away from the contact surface of the base member with respect to the base member which continues to move forward. Since the displacement of the piston member relative to the base member can be detected by the switch means, advancement of the base member by the cylinder device can be stopped by a detection signal from the switch means. In this way, the cylinder device can be stopped at the position where a workpiece is detected, so the workpieces stacked on a pallet can be grasped one after another and moved to another location using simple control. .

Furthermore, after the piston member or the workpiece gripping claw contacts the workpiece, if the piston member moves more than a predetermined amount relative to the base member in the direction in which the stopper flange separates from the contact surface of the base member (this amount of movement is determined by the switch). (the amount of movement of the piston member until the means detects the piston member), the outer circumferential flange of the piston member separates from the inner circumferential flange of the base member, and the piston member moves within the cylinder portion of the base member. Since the workpiece can be moved in the radial direction, even if the workpiece is fixedly held on a jig or the like at a position slightly deviated from the predetermined position, the position of the workpiece can be adjusted by the radial movement of the piston member relative to the base member. It can absorb misalignment and grip the workpiece smoothly. Moreover, when the piston member is moved back together with the base member by the cylinder device after gripping the workpiece with the workpiece gripping claws, the outer peripheral flange of the piston member is pressed against the inner peripheral flange of the base member by the spring force. Since the piston member is tightly fitted and cannot move relative to the cylinder part of the base member, the workpiece is correctly positioned with respect to the robot arm, and a decrease in positional accuracy when the workpiece is moved by the robot arm is prevented. be done.

Even when the workpieces gripped by the handling device are stacked on a pallet, the piston member is displaced relative to the base member which continues to advance when the workpieces come into contact with the target location, so the workpieces are released by the switch means. The desired position can be easily detected. Therefore, the work of stacking workpieces one after another can be performed with simple control.
In addition, when the workpiece contacts the target location, the outer circumferential flange of the piston member separates from the inner circumferential flange of the base member due to the relative displacement between the piston member and the base member, so that the piston member moves into the cylinder portion of the base member. It is possible to move radially relative to the Therefore, even if the position of the jig that receives the workpiece or the mounting part of the machine tool is slightly misaligned, the misalignment is absorbed by the free movement of the piston member relative to the base member, and the workpiece can be fixed smoothly. It can be transferred to a tool, attachment part, etc.

〔Example〕

Embodiments of the present invention will be described below with reference to the drawings.

1 to 3 show an embodiment of the present invention. Referring to FIG. 1, the upper body 10 of the industrial robot can be rotated horizontally together with a rotary table 11, and the upper body 10 can be rotated vertically along a vertical rod 12 provided on the rotary table 11. It is now movable. A robot arm 13 is provided on the upper body portion 10 so as to be movable forward and backward in the longitudinal direction, and a wrist portion 14 at the tip of the robot arm 13
is rotatable about the longitudinal axis of the robot arm 13. The wrist portion 14 may be capable of swinging motion.

In a normal industrial robot, a general-purpose handling mechanism 15 is provided on the wrist portion 14, so this handling mechanism 15 is used to construct the cylinder device 20 of the handling device 30 according to the present invention.
The fixed base 21 of the cylinder device 20 can be held on the wrist portion 15.
may be directly attached to the wrist portion 14 at the tip of the robot arm 13.

Referring to FIG. 2, a cylinder device 20 using hydraulic pressure or pneumatic pressure as a driving source moves the cylinder housing 22 fixed to the fixed base 21 and the cylinder housing 22 forward and backward in the longitudinal direction (up and down direction in the illustrated embodiment). A piston rod assembly 23 is provided. A base member 24 is attached to the front end (lower end in the illustrated embodiment) of the piston rod assembly 23 in the forward and backward movement direction. A guide rod 25 is attached to the base member 24 and extends parallel to the piston/rod assembly 23, and the guide rod 25 is slidably supported on a bearing 26 provided on the fixed base 21 of the cylinder device 20.

A cylinder portion 27 is provided at the center of the base member 24 and extends through the base member 24 in the forward and backward movement direction.
is provided. Fitted into the cylinder portion 27 is a piston member 31 that supports a workpiece gripping claw 37 and a claw actuator 39 for gripping and releasing the workpiece gripping claw 37 . A stopper flange 32 having a larger diameter than the cylinder portion 27 is provided at the rear end of the piston member 31, and the stopper flange 32 can come into contact with the rear end surface of the base member 24.

A piston flange 33 located in front of the base member 24 is provided on the outer periphery of the intermediate portion of the piston member 31, and a compression spring 34 is provided between the piston flange 33 and the base member 24. The piston member 31 is urged forward with respect to the base member 24 by the spring force of the spring 34, and the stopper flange 32 of the piston member 31 is pressed against the rear end surface of the base member 24 by the spring force. It is now coming into contact with

A pair of front and rear inner circumferential flanges 27A are provided on the inner surface of the cylinder portion 27 at intervals in the axial direction thereof. The inner diameter of the inner peripheral flange portion 27 is smaller than the inner diameter of the cylinder portion 27 and larger than the outer diameter of the piston member 31. When the piston member 31 is in contact with the rear end surface of the base member 24, a stopper flange 32 is closely fitted to the inner circumferential flange 27A to restrict radial movement of the piston member 31 with respect to the cylinder portion 27. A pair of front and rear outer peripheral collar portions 31A are provided. The outer flange 31A separates from the inner flange 27A when the stopper flange 32 moves backward by a predetermined amount or more from the rear end surface of the base member 24, allowing the piston member 31 to move freely within the cylinder 27A. .

A plurality of claw support brackets 36 are arranged radially and screwed to a support plate 35 attached to the tip of the piston member 31, and each claw support bracket 36 has a workpiece gripping claw 37 attached to the pin 3.
8, it is supported to be swingable, that is, to be capable of gripping and releasing operations.

The pawl actuator 39 includes a cylinder member 40 that is slidably fitted to the outer periphery of the piston flange 33 of the piston member 31.
Cylinder flange 4 integrally provided at the tip of 0
1 is slidably fitted on the outer periphery of the piston member 31 in front of the piston flange 33. and,
A pressure introduction chamber 44 is defined between the piston flange 33 and the cylinder flange 41. A pipe 45 for introducing compressed air, hydraulic oil, etc. into the pressure introduction chamber 44 is fixed to the piston flange 33 . A pipe 45 extends through the base member 24 and fixed base 21 and parallel to the guide rod 25.

A plurality of ring support brackets 46 are screwed to the front surface of the cylinder flange 41.
Each bracket 46 and each work gripping claw 37 are connected via links 47, respectively.

A compression spring 48 is provided between the support plate 35 at the tip of the piston member 31 and the cylinder flange 41, and the spring force of this spring 48 urges the cylinder flange 41 toward the piston flange 33 side. The workpiece gripping claw 37 is biased in the workpiece release direction. Pressure introduction chamber 4
When compressed air at a predetermined pressure is introduced into the link 5, the cylinder flange 41 moves in front of the piston flange 33 against the spring force of the spring 48, and the link 4
7, the workpiece gripping claw 37 is moved in the workpiece gripping direction.

Here, the workpiece gripping claw 37 and the bracket 4 are
6 and the link 47 are configured to grip the outer periphery of a flange-shaped workpiece, but they can also be configured to grip the inner periphery of an annular or cylindrical workpiece. It is sufficient that there are at least two workpiece gripping claws 37, but the number can be set appropriately as necessary. Furthermore, the workpiece gripping claws 37 and the like can be replaced depending on the shape and size of the workpiece.

The cylinder device 20 is provided with a pair of front and rear detection switches 49 and 50 for detecting when the operating stroke of the piston/rod assembly 23 has reached its limit. On the other hand, the guide rod 25 fixed to the base member 24 is provided with a detection switch 51 for detecting displacement of the piston member 31 with respect to the base member 24. Piston member 3
In the direction in which the stopper flange 32 of No. 1 separates from the rear end surface of the base member 24, that is, in the forward and backward movement direction of the base member 24, rearward (in the illustrated embodiment, upward)
When the projection 5 provided on the pipe 45 is displaced to
2 pushes the switch lever 51A of the detection switch 51, and the detection switch 51 is activated. Here, as can be seen from FIGS. 2 and 3, the piston member 3
The amount of movement of the piston member 31 until the outer peripheral flange 31A of the cylinder part 1 of the base member 24 is separated from the inner peripheral flange 27A of the cylinder part 27 of the base member 24 is the amount of movement of the piston member 31 until the detection switch 51 detects the piston member 31.
is set smaller than the amount of movement. Detection signals output from the detection switches 49, 50, and 51 are sent to a robot control device (not shown). The control device sends a control signal to a pressure supply/release device (not shown) to the cylinder device 20 and the pressure introduction chamber 44 in accordance with the input detection signal.

When using a handling device having the above configuration to pick up workpieces stacked on a pallet one after another and transport them to a mounting section of a machine tool, the workpiece gripping claw 37 is moved directly above the workpieces by the robot arm 13 or the like. After being moved to the position, the piston member 31 is moved to the base member 2 by the cylinder device 20.
4 and is advanced downward. Piston member 3
1 or when the workpiece gripping claw 37 comes into contact with the workpiece, the piston member 31 stops at that position. It is displaced against the spring force of the spring 34 in a direction away from the contact surface, that is, the rear end surface. Since the displacement of the piston member 31 with respect to the base member 24 can be detected by the detection switch 51, the advancement of the base member 24 by the cylinder device 20 can be stopped by the detection signal from the detection switch 51. In this way, the cylinder device 20 can be stopped at the position where a workpiece is detected, so that the workpieces stacked on a pallet can be grasped one after another and moved to another location using simple control. can.

Further, after the piston member 31 or the workpiece gripping claw 37 comes into contact with the workpiece, the stopper flange 3
When the piston member 31 is displaced by a predetermined amount or more with respect to the base member 24 in the direction in which the piston member 2 moves away from the contact surface of the base member 24, the outer peripheral flange portion 3 of the piston member 31
1A is detached from the inner peripheral flange 27A of the base member 24, and the piston member 31 becomes movable in the radial direction within the cylinder portion 27 of the base member 24. In addition,
As described above, the outer peripheral flange 3 of the piston member 31
The amount of movement of the piston member 31 until the piston member 1A separates from the inner peripheral flange portion 27A of the cylinder portion 27 of the base member 24 is set smaller than the amount of movement of the piston member 31 until the detection switch 51 detects the piston member 31. Therefore, after the outer circumferential flange 31A is detached from the inner circumferential flange 27A and the piston member 31 becomes movable in the radial direction with respect to the cylinder portion 27 of the base member 24, the detection switch 51 is activated and the cylinder device 20 is activated. The base member 24 is stopped from moving forward. Therefore, even if the workpiece is fixedly held on a jig or the like at a position slightly deviated from a predetermined position, the displacement of the workpiece is absorbed by the free movement of the piston member 31 with respect to the base member 24, and the workpiece is can be gripped smoothly.

After the workpiece is gripped by the workpiece gripping claws 37, the piston member 31 is moved by the cylinder device 20.
When the piston member 31 is retracted upward together with the base member 24, the outer periphery flange 31A of the piston member 31 is tightly fitted into the inner periphery flange 27A of the base member 24 by the spring force of the spring 34, and the piston member 31 is Since the base member 24 cannot move freely relative to the cylinder portion 27, the workpiece is correctly positioned with respect to the robot arm 13, and a decrease in positional accuracy when the workpiece is moved by the robot arm 13 and the like is prevented.

Even when workpieces gripped by the workpiece gripping claws 37 are stacked on a pallet, the piston member 31 is displaced relative to the base member 24, which continues to move downward, when the workpieces come into contact with the target location. The detection switch 51 can easily detect that the release position has been reached. Therefore, the work of stacking workpieces one after another can be performed with simple control. Further, when the workpiece comes into contact with the target location, the piston member 31 is caused by relative displacement between the piston member 31 and the base member 24
The outer periphery flange 31A is the inner periphery flange 2 of the base member 24.
7A, the piston member 31 can freely move in the radial direction with respect to the cylinder portion 27 of the base member 24. Therefore, even if the position of the jig that receives the workpiece or the attachment part of the machine tool is slightly misaligned, the misalignment is absorbed by the free movement of the piston member 31 relative to the base member 24.
Workpieces can be smoothly transferred to jigs, mounting parts, etc.

〔Effect of the invention〕

As is clear from the above description, according to the present invention, it is possible to perform handling work when the height position of the workpiece gripping operation and release operation constantly changes, and moreover, the workpiece to be gripped can be easily controlled. Even when the workpiece is fixedly held at a position that is deviated from the specified position, or when the jig, attachment part, etc. for holding the workpiece gripped by the handling device is deviated from the specified position, the workpiece gripping operation and workpiece release cannot be performed. It is possible to provide a handling device that can operate smoothly and prevent a decrease in positional accuracy when moving a workpiece by a robot arm.

[Brief explanation of drawings]

FIG. 1 is a side view showing a state in which a handling device according to an embodiment of the present invention is attached to an industrial robot, FIG. 2 is a longitudinal cross-sectional side view of the main part of the handling device shown in FIG. 1, and FIG. FIG. 2 is a vertical cross-sectional side view of a main part showing a work gripping operation state of the handling device shown in FIG. 1; In the figure, 13 is a robot arm, 14 is a wrist part, 20 is a cylinder device, 24 is a base member,
27 is a cylinder part, 27A is an inner flange part, 31 is a piston member, 31A is an outer periphery flange part, 32 is a stopper flange, 34 is a spring, 37 is a work gripping claw,
39 is a claw actuator, and 51 is a detection switch.

Claims (1)

[Claims] 1 A cylinder portion 27 extending through the base member 24 that is linearly driven forward and backward by a cylinder device 20 provided at the tip of the lock arm 13 in the forward and backward movement direction is provided, and a workpiece located in front of the cylinder portion 27 is gripped. A piston member 31 supporting the workpiece gripping claw 37 and a claw actuator 39 for gripping and releasing the workpiece gripping claw 37 is fitted into the cylinder portion 27 to be movable in the forward and backward movement direction relative to the base member 24. The spring 34 provided between the piston member 24 and the piston member 31 urges the piston member 31 forward of the base member 24, and the spring force causes the stopper flange 32 provided at the rear end of the piston member 31 to be pushed forward of the base member 24.
4, and is provided between the base member 24 and the piston member 31 for detecting that the stopper flange 32 of the piston member 31 has left the rear end surface of the base member 24 by a predetermined distance. A switch means 51 is provided, and a pair of inner circumferential flanges 27A are provided at an interval in the axial direction on the inner surface of the cylinder portion 27 and have a smaller diameter than the cylinder portion 27 and a larger diameter than the piston member 31. When the stopper flange 32 is in contact with the rear end surface of the base member 24, the stopper flange 32 tightly fits into the inner circumferential flange 27A to restrict the radial movement of the piston member 31 with respect to the base member 24. 32
A pair of outer circumferential flanges 31A that detach from the inner circumferential flanges 27A and allow the piston member 31 to move radially relative to the base member 24 when the piston member 31 moves backward by a predetermined amount or more from the rear end surface of the base member 24. The switching means 51 controls the amount of movement of the piston member 31 until the outer circumference flange 31A separates from the inner circumference flange 27A.
is set to be smaller than the amount of movement of the piston member 31 until the piston member 31 is detected.