JP5675401B2 - manipulator - Google Patents

Description

  The present invention relates to a manipulator in which an end effector is detachably attached to a robot arm via an engaging member to grip and assemble various components.

  In recent years, there has been a growing demand for automation for the assembly of small and complicated products such as cameras. In order to assemble these small products, it is necessary to perform high-speed and precise assembly using a small industrial robot.

As an industrial robot, a manipulator in which an end effector provided with a plurality of fingers is detachably attached to an articulated robot arm is used, and the end effector can be exchanged according to work applications. The end effector is provided with an electric actuator, a sensor, and the like, and is electrically connected to the robot arm to exchange electric signals and supply power.
As the electrical connection between the robot arm and the end effector, as disclosed in Patent Document 1, an external wiring system is generally used in which the electrical wiring between the robot arm and the end effector is turned outward and connected by a connector. .
As a further improved configuration, as disclosed in Patent Document 2, electric wiring is arranged inside the robot arm, and the electric connector is pressed by the lock lever of the end effector attaching / detaching mechanism to reduce the connector attaching / detaching force. There is a configuration that makes this easier. Further, as disclosed in Patent Document 3, there is a configuration in which a large number of contacts can be arranged without increasing the diameter of the end effector by arranging an electric contact at the center of the end effector.

Japanese Patent Laid-Open No. 05-084688 JP-A-63-251183 JP-A-4-360783

  A basic configuration of the manipulator is shown in FIG. Reference numeral 201 denotes a robot arm, 1 denotes an end effector, and 304 denotes a workpiece, which is a component that is gripped and assembled by the end effector 1.

  In order to assemble a small part into a small product having a complicated structure such as a camera, the end effector 1 is arranged in a narrow space while the robot arm 201 is moved to various postures. Therefore, it is required to reduce the outer diameter R so that the product does not interfere with the end effector 1 and the robot arm 201 and to reduce the distance L between the tip of the end effector 1 and the rotation axis of the robot arm 201.

  Further, in order to assemble a small part or a flexible part, it is necessary to arrange a large number of control sensors such as a force sensor in the end effector 1, and the number of electric wirings increases accordingly, and the end effector 1 The number of electrical contacts to be connected to increases. Therefore, it is necessary to increase the number of contacts while reducing the size.

  However, in the outer wiring system in which the robot arm, the end effector, and the wiring arranged outside in Patent Document 1 are arranged on the outside, it is necessary to largely limit the movable range of the robot arm in order to avoid interference between the wiring that protrudes outside and the workpiece. is there. Therefore, this method is not suitable as a manipulator for assembling small parts.

  On the other hand, the internal wiring system in which the wiring of the robot arm and the end effector is arranged inside is also the end because the conventional example shown in Patent Document 2 uses a seesaw type lock lever, a spring for pressurization, and a contact contact. It was not suitable for downsizing effectors. In the above conventional example seen in Patent Document 3, many contacts can be arranged without increasing the outer diameter R, but there is a problem that the distance L becomes long.

  In both Patent Document 2 and Patent Document 3, the contact points of the robot arm and the end effector are brought into contact with each other by pressure contact. Therefore, in order to prevent conduction failure due to contamination of the contact member or oxide film and to make the conduction stable, it is necessary to apply pressure to the electrical contact with a pressure spring.

The present invention for solving the above problems
A robot arm having a first abutment surface with a first electrical contact;
An end effector connected to the robot arm having a second abutment surface with a second electrical contact;
An engagement member having a gap with an inner surface that is arranged with contact wiring and engages the first and second contact surfaces;
Have
The robot arm and the end effector are engaged with each other by the engaging member, and the robot arm and the second electrical contact portion and the contact wiring are brought into contact with each other. The manipulator is characterized in that the end effector is electrically connected.

  According to the present invention, since the engaging member that engages the robot arm and the end effector also serves as a wiring, it is possible to provide a small manipulator with a reduced wiring space.

  According to the present invention, since the contact is brought into sliding contact with the attachment / detachment of the engaging member, it is possible to provide a manipulator including a highly reliable contact for contact failure.

It is a figure explaining the engaging part which concerns on the Example of this invention. It is a figure explaining the manipulator based on the Example of this invention. It is a figure explaining the end effector which concerns on the Example of this invention. It is a figure explaining attachment of the end effector concerning the example of the present invention. It is a figure explaining attachment of the end effector concerning the example of the present invention. It is a figure explaining the engaging member which concerns on the Example of this invention. It is sectional drawing explaining the engaging part which concerns on the Example of this invention. It is a figure explaining the prior art example of this invention.

Example 1
Embodiments of the present invention will be sequentially described below with reference to the drawings.
FIG. 2 is a diagram schematically showing the robot arm 201, the end effector 1 attached to the robot arm 201, and its control unit and power supply unit.

  The robot arm includes a plurality of links and joints connecting the links, and can be freely driven by a signal from the robot arm controller 210 by a motor (not shown).

  The end effector includes a finger module 100 provided on the substrate, a motor 105, and a force sensor 110 that detects an external force applied to the end effector.

  An end effector control unit 180 that controls the operation of the end effector 1 is connected to the end effector 1 via a robot arm 201 via a signal line 181. The end effector control unit 180 exchanges control signals to the motors 105 a and 105 b that drive each joint of the finger module 100, calculates a force from the displacement signal detected by the force sensor 110, and the like. Here, a finger module having two joints and a motor for driving each joint are depicted.

  The driving power of the motors 105 a and 105 b provided in the end effector 1 is supplied from the end effector power supply unit 182 through the power supply line 183 of the robot arm 201.

  A robot arm control unit 210 that controls the operation of the robot arm 201 is connected to the robot arm 201. Information on the force applied from the end effector control unit 180 to the force sensor 110 of the end effector 1 is received by the robot arm control unit 210 and reflected in the operation of the robot arm 201.

  As shown in FIG. 3, the end effector 1 includes a finger module 100 that grips a component, and a force sensor unit 110 that detects an assembly reaction force when the component is gripped and assembled. Each of the finger modules 100 includes a fingertip member 101, a middle joint member 102, a first joint 103 and a second joint 104, a motor 105a for driving the first joint, and 105b for driving the second joint. . By placing a plurality of these finger modules 100 on the end effector housing 109 (four in this embodiment) and independently driving each joint by the end effector control unit 180, it is possible to grip a workpiece of various shapes. It has become.

(Engagement of end effector and robot arm)
A positioning method for engaging the end effector 1 with the robot arm 201 will be described in detail.
As shown in FIG. 4, the robot arm 201 has a mounting surface having a cylindrical convex portion 212, and a round hole portion (not shown) at a corresponding position on the end effector 1 side.

  First, when the end effector 1 is brought into contact with the cylindrical convex portion 212 of the robot arm 201, the convex portion 212 is engaged with a round hole portion (not shown) of the end effector 1 as shown in FIG. And the end effector 1 are positioned coaxially. This regulates the x and y axis directions.

  Next, the detachable engagement member showing one characteristic part of the present application will be described with reference to FIG.

  Engagement surfaces 120 a that engage with the engagement members are formed at four locations on the outer edge (circumference) of the attachment surface of the end effector 1 to the robot arm 201. (In this embodiment, since the engagement surface 120a is formed in a wedge shape, it is hereinafter referred to as a wedge surface). A first contact surface 121 is formed on each wedge surface. Similarly, the robot arm 201 has an engagement surface (hereinafter referred to as a wedge surface) 220a that engages with the engagement member, and a second contact surface 221 is formed on each of the engagement surfaces. Electrical contact portions 222 and 122 are formed on the contact surfaces, respectively.

The electrical contact part 222 is electrically connected to the end effector control part 180, and the electrical contact part 122 is electrically connected to the motor 105 and the force sensor part 110 inside the end effector 1.
The “wedge” formed by the wedge surface 220a and the wedge surface 120a is joined to the engaging member described below.

  Then, the engagement member 300a is tightened with the bolt 303 in a state where the wedge surface 120a of the end effector 1 and the wedge surface 220a of the robot arm 201 are in contact with each other.

  As shown in FIGS. 6A and 6B, the engaging member 300a has an abutting surface 321 on the inner surface of the wedge-shaped gap so as to correspond to the first abutting surface 121 and the second abutting surface 221. 322 is formed, and a through hole 302 into which the bolt 303 can be inserted is formed. Further, a screw hole portion communicating with the through hole 302 is formed on the upper surface of the wedge surface 220a.

  As shown in FIG. 7 (a), the engagement member 300a is inserted in the direction of the arrow in the drawing and tightened with the bolt 303, whereby the end effect is obtained due to the wedge effect formed by the wedge surface 120a and the wedge surface 220a. The effector 1 and the robot arm 201 are pressed against each other in the F direction in FIG. 7B, and the position in the Z direction shown in FIG. 5 is determined.

  Further, as shown in FIG. 1, the width h1 of the engaging member 300a and the groove width h2 of the wedge surface 120a and the wedge surface 220a are formed by fitting dimensions, and the engagement member 300a is tightened to show the width shown in FIG. Rotation around the Z axis is restricted. At this time, the engagement portions of the other engagement members 300b, c, and d have a gap so as not to hinder the restriction of the rotation direction of the engagement member 300a.

  As described above, the positions of the end effector 1 and the robot arm 201 are determined with high accuracy by tightening and attaching the engaging member 300a having the wedge-shaped gap.

  In addition, the shape of the member described as the “wedge” may be rectangular, and in short, the engaging member only needs to have a gap including inner surfaces that engage with the first and second contact surfaces.

(End effector electrical connection method)
Next, an electrical connection method to the end effector 1 will be described.
As shown in FIG. 1, the contact surface 221 of the robot arm 201 has a first electrical contact portion 222, and an electrical signal transmitted from the control unit 180 through the robot arm 201 is supplied thereto. . Similarly, the contact surface 121 of the end effector has a second electrical contact portion 122, which is connected to the end effector motors 105a and 105b and the force sensor 110.

  The electrical contact portions 122 and 222 are made of a conductive member, and are disposed on a surface that is one step deeper than the above-described contact surfaces 121 and 221 in a state of being electrically insulated from the wedge surfaces 120a and 220a. Therefore, since the electrical contact portions 122 and 222 cannot be easily touched, contact contamination and short circuit can be prevented.

  As shown in FIG. 6B, the contact wiring 301 is disposed on the contact surfaces 321 and 322 in the wedge-shaped gap of the engagement member 300a, and the contact and the conduction path are formed by the conductive member.

  In the state before the engagement member 300a is attached, the electrical contact portions 122 and 222 are not connected and are electrically disconnected (FIG. 7A). Next, when the engaging member 300a is attached and tightened with the bolt 303, the electrical contact portions 122 and 222 are electrically connected to the contact wiring 301 (FIG. 7B). Only in this state, the end effector 1 and the end effector controller 180 are electrically connected to enable the end effector 1 to operate.

  The removal is performed in the reverse order of the attachment, and the electrical connection is cut off by the removal of the engaging member.

  The contact wiring 301 is arranged on the contact surfaces 321 and 322 and the bottom surface of the wedge-shaped gap, and the contact wiring 301 contacts the electrical contact portions 122 and 222 by the mounting operation. The surface cleaning effect works. Therefore, it is possible to prevent a foreign matter from adhering to the contact surface or the occurrence of poor conduction due to the formation of an oxide film on the contact surface.

  In addition, when the fastening by the engaging member is insufficient, power is not supplied to the end effector, so that the end effector is prevented from being detached during the operation of the robot due to insufficient fastening, which is advantageous in terms of safety. is there.

  In the present embodiment, the configuration in which the contacts are arranged on the engaging member 300a that restricts the rotation around the Z-axis among the plurality of engaging members that attach and detach the end effector 1 has been described. In this case, the contact wiring 301 is an electrical contact. Since the positions of the portions 122 and 222 are determined by fitting, contact arrangement with higher density can be performed. However, the contact points may be arranged on other engagement members.

  Further, in this embodiment, the control signal contacts of the end effector control unit 180 are arranged. However, since all the contacts to be electrically connected can be applied, the power supply line of the end effector power supply unit 182 is also applicable. Is possible.

  As described above, the engagement member 300a of the end effector 1 and the robot arm 201 serves as a wiring in order to make the contact portions 122 and 222 conductive. This saves electric wiring and reduces the size of the robot arm. To contribute.

  Further, since the contact pressure is obtained by using the tightening force of the wedge-shaped portion of the engaging member, the end effector 1 and the robot arm 201 can be made small because no special pressurizing mechanism or spring is required for the contact configuration. The manipulator A can be downsized.

  In addition, since the contacts are rubbed each time the end effector 1 is attached / detached and a cleaning effect is exerted, a highly reliable contact configuration can be realized.

A Manipulator 1 End effector 201 Robot arm 100 Finger module 105a, 105b Actuator 110 Force sensor 120a, b, c, d Wedge surface 181 Signal line 183 Power line 212 Protruding portion 220a, b, c, d Wedge surface 300a, b, c, d engagement member 301 contact wiring 121 contact surface (end effector)
221 Contact surface (robot arm)
122, 222 Contact surface (engagement member) with electrical contact portions 321 and 322

Claims (2)

A robot arm having a first abutment surface with a first electrical contact;
An end effector connected to the robot arm having a second abutment surface with a second electrical contact;
An engagement member having a gap with an inner surface that is arranged with contact wiring and engages the first and second contact surfaces;
Have
The robot arm and the end effector are engaged with each other by the engaging member, and the robot arm and the second electrical contact portion and the contact wiring are brought into contact with each other. A manipulator characterized by being electrically connected to an end effector.   A plurality of the engaging members are intermittently arranged around the engaging portion of the robot arm and the end effector, and one of the engaging members is formed with the first and second contact surfaces. The manipulator according to claim 1, wherein the manipulator is configured to be fitted to the portion.

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