JP2013107160A - Gripping part positioning device and method - Google Patents

Abstract

PROBLEM TO BE SOLVED: To automatically change the position of a gripping part of a workpiece chucking device, by causing the gripping part prepared on the workpiece chucking device mounted on a robot arm to be shifted and positioned in accordance with the change of the type of a workpiece, without having a driving device provided for moving the gripping part to the robot or the workpiece chucking device.SOLUTION: A gripping part positioning device 500 includes a base unit 510. The base unit 510 comprises: a workpiece chucking device positioning section 520 that positions the workpiece chucking device equipped with a gripping mechanism capable of switching between a movement-allowed state and movement-regulated state; and a gripping part positioning mechanism 530 that includes a locking recess 531 engageable with the gripping mechanism, while shifts three-dimensionally the locking recess 531 engaged with the gripping mechanism that is in the state of being allowed to be shifted in the workpiece chucking device 1, thereby causing the gripping mechanism to be moved to and positioned at a position corresponding to the to-be-gripped part of the workpiece according to the kind of the workpiece.

Description

  The present invention relates to a gripping part positioning apparatus and method, and more particularly, to position the gripping part in a work gripping apparatus that is mounted on a robot arm and grips various works with the gripping part according to the type of the work. The present invention relates to a gripper positioning apparatus and method.

In production lines that process and assemble multiple parts to complete products with various variations, technologies for flexibly handling various types of workpieces and efficiently transporting them are used (for example, patents). References 1, 2).
In Patent Document 1, it is possible to deal with a wide variety of workpieces by the hand portion replacement mechanism 54 that replaces the hand portion that grips the workpiece.
In Patent Document 2, the exchange time is shortened by rotating a plurality of hands by using a turret type robot hand, and selecting them by switching.

  However, in the hand part replacement mechanism 54 of Patent Document 1, separate hands must be prepared according to the type of work, and thus there is a problem in securing the production cost of the hand and securing the place. Further, since the structure of the turret type robot hand of Patent Document 2 is complicated, there is a problem in that the tip of the robot becomes heavy and the operation is restricted, and there is a limit to the type of switching.

  In order to solve such a problem, it is possible to change the position of the gripping unit in a workpiece gripping device that grips the workpiece when the type of the workpiece is changed, and to reduce the weight of the tip side of the robot arm, the gripping unit It is conceivable to adopt a configuration in which a robot or workpiece gripping device is not provided with a driving device for moving the robot.

  However, when such a configuration is adopted, it is possible for the operator to change the position of the gripping part in the work gripping device every time the type of the work is changed, but the work is complicated and takes time. Or an error may occur. On the other hand, in order to improve the productivity by automating a series of operations, appropriate measures are required.

JP-A-6-262281 JP-A-5-301189

  The present invention has been made in view of such circumstances, and a driving device for moving a gripping portion provided to a workpiece gripping device mounted on a robot arm to a robot or a workpiece gripping device is provided. The object is to automatically change the position of the gripping part in the work gripping device by moving and positioning according to the change of the type of the work without providing it.

  In order to achieve the above-mentioned object, the invention according to claim 1 is characterized in that the gripping portion in a workpiece gripping device that is mounted on a robot arm and grips various workpieces by the gripping portion is moved according to the type of the workpiece. A gripping unit positioning device for performing the gripping operation, wherein the gripper is provided on the floor, and the gripper is provided on the base and can be switched between a permitted state and a restricted state in the workpiece gripping device. A workpiece gripping device positioning portion for positioning the workpiece gripping device provided with a portion on the base, and an engagement portion provided on the base and engageable with the gripping portion, allowing movement in the workpiece gripping device The gripper is moved to a position corresponding to the gripped part of the work according to the type of the work by moving the engaging part engaged with the gripped part in the three-dimensional state. Characterized in that and a gripper positioning mechanism for positioning Te.

According to the present invention, the gripping portion provided in the workpiece gripping device mounted on the robot arm can be changed according to the type of workpiece without providing a driving device for moving the gripping portion to the robot or the workpiece gripping device. Thus, by moving and positioning, it is possible to automatically change the position of the gripping portion in the workpiece gripping device.
Therefore, it becomes possible to deal with various workpieces having variations while reducing the weight of the tip side of the robot arm.

  The invention according to claim 2 is the gripping part positioning device according to claim 1, wherein the gripping part positioning mechanism supports the engaging part movably in directions of three axes orthogonal to each other. And a driving device for moving the engagement portion in the direction of the three axes.

  According to the present invention, it is possible to reliably cope with a workpiece in which the gripped portion is formed at various positions that differ for each type of workpiece having variations. Further, the three-dimensional orthogonal coordinate system is easier to grasp the spatial position than the polar coordinate system, and the work such as robot teaching is easier to perform, so the workability is improved.

  Invention of Claim 3 is a holding part positioning apparatus of Claim 2, Comprising: The said support mechanism moves via a rolling bearing along the rail extended in the direction of the said 3 axis | shaft, and the said rail It has a linear motion guide mechanism provided with the block engaged possible.

  According to the present invention, the engaging portion can be smoothly moved without play along the rail extending in the direction of the three axes.

  According to a fourth aspect of the present invention, in the gripping part positioning device according to any one of the first to third aspects, the engaging part may be configured such that the gripping part has a gripped part of a workpiece from the outside. In the case of an outer type that presses and grips inwardly, it is a convex part, and in the case of an inner type that presses and grips the gripped part of the work from the inside to the outside, it is a concave part. It is characterized by that.

  According to the present invention, it is possible to cope with a case where the gripping portion is an outer type, an inner type, or a combination of both types. In addition, it is possible to handle a workpiece having a complicated structure.

  Invention of Claim 5 is a holding part positioning apparatus of Claim 4, Comprising: The said engaging part is the said several convex part which has a circular cross section of a different diameter according to several types of workpiece | work, and / Or it has the said recessed part, It is characterized by the above-mentioned.

  According to this invention, a plurality of convex portions and / or concave portions having different diameters can be prepared in advance so as to be adapted to a plurality of gripping portions having different sizes. Thereby, even when the size of the gripping portion varies depending on the type of workpiece, it is possible to cope with it.

  A sixth aspect of the present invention is the gripping unit positioning device according to any one of the first to fifth aspects, wherein the workpiece gripping device positioning unit is provided in the workpiece gripping device. A base side set portion that can be set on the side set portion is provided, and has a support column that is erected on the base.

  According to this invention, the workpiece gripping device and the base can be positioned with a compact configuration via the support column. In addition, a wide space for moving the gripping portion between the workpiece gripping device and the base can be secured, and the degree of freedom of layout of the gripping portion positioning mechanism on the base is increased.

  A seventh aspect of the present invention is the gripping unit positioning device according to any one of the first to sixth aspects, wherein the gripping unit positioning mechanism is a stopper that prevents the engaging unit from being overmovable. It is characterized by having.

  According to the present invention, even if a running abnormality of the engaging portion occurs, the movement of the engaging portion is limited by the stopper, so that it is possible to protect the workpiece gripping device and the gripping portion positioning device.

  The invention according to claim 8 is the gripping part positioning device according to any one of claims 1 to 7, wherein the gripping part positioning mechanism is allowed to move the engaging part. And a locking mechanism that can be switched to a restricted state.

  According to this invention, after moving the engaging portion, it can be reliably stopped at a predetermined position. Therefore, for example, when the engaging portion is moved by a drive device that is difficult to control precisely, such as an air cylinder, the engaging portion can be stopped using the locking mechanism by detecting the predetermined position.

  In order to achieve the above object, the invention according to claim 9 is configured to move the gripping portion in a work gripping device attached to a robot arm and gripping various workpieces by the gripping portion according to the type of the workpiece. A gripping unit positioning method for positioning the workpiece gripping device, wherein the workpiece gripping device positioning unit provided on the base installed on the floor is switched between a permitted state and a restricted state in the workpiece gripping device A step (a) of positioning the workpiece gripping device including the gripping portion that is possible, and a gripping portion positioning mechanism provided on the base can be engaged with the gripping portion provided in the gripping portion positioning mechanism A step (b) of three-dimensionally moving the engaging portion with the gripping portion, a step (c) of setting the gripping portion in a state in which movement of the workpiece gripping device is permitted, A step (d) in which a gripping portion positioning mechanism moves the engaging portion engaged with the gripping portion to a position corresponding to the gripped portion of the workpiece according to a type of the workpiece; and the gripping portion grips the workpiece A step (e) of setting the movement in the apparatus to be regulated, a step (f) of repeating the steps (b) to (e) when the work gripping device includes a plurality of the gripping units, and the gripping A step (g) in which a part positioning mechanism separates the engaging part from the gripping part and moves the engaging part back to a predetermined engaging part reference position; and A step (h) of separating the gripping device and moving the workpiece gripping device back to a predetermined workpiece gripping device reference position.

According to the present invention, the gripping portion provided in the workpiece gripping device mounted on the robot arm can be changed according to the type of workpiece without providing a driving device for moving the gripping portion to the robot or the workpiece gripping device. Thus, by moving and positioning, it is possible to automatically change the position of the gripping portion in the workpiece gripping device.
Therefore, it becomes possible to deal with various workpieces having variations while reducing the weight of the tip side of the robot arm.

  According to the present invention, the gripping unit provided in the workpiece gripping device attached to the robot arm can be changed according to the type of workpiece without providing a driving device for moving the gripping unit to the robot or the workpiece gripping device. Thus, it is possible to provide a gripping part positioning device and method that can automatically change the position of the gripping part in the workpiece gripping apparatus by moving and positioning.

It is a top view which shows the workpiece carrying-out process for demonstrating the usage example at the time of applying the holding | grip part positioning device which concerns on embodiment of this invention to a workpiece | work holding device. It is sectional drawing which shows the structure of the principal part of the attitude | position control apparatus of a workpiece | work holding apparatus. It is a figure which shows operation | movement of the holding | grip mechanism in a workpiece | work holding apparatus, (a) is sectional drawing, (b) is a side view of a front-end | tip part. It is a figure which shows the holding mechanism in a workpiece | work holding apparatus, (a) is a perspective view, (b) is the state before holding, (c) is an exploded view of a driven member, (d) shows the state hold | gripped. . It is a schematic sectional drawing which shows a mode that the positioning of the holding | grip mechanism in a workpiece | work holding device is performed using a holding part positioning device. It is a typical front view which shows operation | movement (when the rigidity of the pallet which mounts a workpiece | work is high) in the attitude | position control apparatus, (a) is the state before inserting the front-end | tip part of a holding mechanism in a to-be-held part, (B) shows the state after inserting the front-end | tip part of a holding mechanism in a to-be-held part. It is a typical front view which shows operation | movement (when the rigidity of the pallet which mounts a workpiece | work is low) in an attitude | position control apparatus, (a) is the state before inserting the front-end | tip part of a holding mechanism in a to-be-held part, (B) shows the state after inserting the front-end | tip part of a holding mechanism in a to-be-held part. It is a partial front sectional view for explaining operation of a work gripping device, and shows a state before gripping with a gripping device. It is a fragmentary front sectional view for demonstrating operation | movement of a workpiece | work holding apparatus, and shows the state which the support shaft contact | abutted to the workpiece | work. It is a fragmentary front sectional view for demonstrating operation | movement of a workpiece | work holding apparatus, and shows the state which the outer cylinder of the support shaft contact | abutted to the workpiece | work. It is a fragmentary front sectional view for demonstrating operation | movement of a workpiece | work holding | grip apparatus, and shows the state which clamp was completed. It is a fragmentary front sectional view for demonstrating operation | movement of the workpiece | work holding | gripping apparatus when the workpiece | work has produced the position shift excessively. It is a top view of a holding part positioning device. It is a side view of a holding part positioning device. It is a figure which shows the periphery of the engaging member which has an engaging recessed part shown by FIG. 13 and FIG. 14, (a) is a top view, (b) is a front view. It is a perspective view for demonstrating an outer type holding mechanism, (a) shows an external appearance, (b) is sectional drawing which shows an internal structure. It is a sectional front view showing composition and operation of an outer type grasping mechanism, (a) shows a state before grasping, and (b) shows a grasped state. It is a partially exploded perspective view for demonstrating an outer type holding mechanism. It is a figure which shows the periphery of the engaging member which has an engaging convex part of the holding part positioning device used when the to-be-held part of workpiece | work is convex parts, such as a boss | hub, (a) is a top view, (b) Is a front view.

Hereinafter, embodiments of the present invention will be described in detail with reference to the drawings as appropriate.
First, a workpiece gripping device 1 in which a gripping unit positioning device according to an embodiment of the present invention is used will be described in detail with reference mainly to FIGS.

As shown in FIG. 1, the workpiece gripping device 1 is suitably used as a gripping device (robot hand) that is attached to the tip 102 of the robot arm 101 of the articulated robot 100 and grips a workpiece W having various variations. be able to.
In the present embodiment, a case will be described in which the workpiece gripping device 1 is mounted on the multi-joint robot 100 by being mounted on the posture control device 2 described later.
The articulated robot 100 includes a workpiece gripping device 1 in which a workpiece W placed on a pallet 201 that has been transported to a take-out position by a transport device 200 is mounted on a distal end portion 102 of a robot arm 101 (see also FIG. 2). Thus, the gripping portion Wa (FIG. 2) of the workpiece W is gripped at three positions, and the robot arm 101 is turned to release the gripping state and transport the workpiece to the unloading device 300 (see the workpiece W1).

  Here, it is assumed that the workpiece W such as a transmission case or a torque converter case where the position of the concave portion or the convex portion that becomes the gripped portion Wa changes depending on the product variation is gripped, but the present invention is limited to this. However, the present invention can be applied to gripping various workpieces.

  In the present embodiment, a case where the workpiece gripping device 1 is mounted on the posture control device 2 and mounted on the articulated robot 100 will be described. However, the present invention is not limited to this and the posture control device 2 is not used. In addition, the workpiece gripping device 1 may be attached to the distal end portion 102 of the robot arm 101.

  As shown in FIG. 2, the workpiece gripping apparatus 1 includes a support plate 22 connected to the robot arm 101 and a gripping mechanism (grip unit) 11 that is disposed on the support plate 22 and grips a gripped portion Wa of the workpiece W. And a triaxial movement mechanism 12 that is a free movement mechanism that supports the gripping mechanism 11 so as to be freely movable, and a movement restriction device 13 that restricts the movement of the gripping mechanism 11. That is, the gripping mechanism 11 can be switched between a state in which movement of the work gripping device 1 is permitted and a state in which the movement is restricted.

  Then, as shown in FIG. 1, the workpiece gripping device 1 is configured to move and grip the gripping mechanism 11 according to the type of workpiece in order to adapt the gripping mechanism 11 to various workpieces. Are separately provided in the vicinity of the articulated robot 100. Details of the gripper positioning device 500 will be described later.

  In the present embodiment, the workpiece gripping device 1 is provided with the same gripping mechanism 11 at three locations, and the gripped portion Wa formed of a recess such as a through-hole formed in the workpiece W is gripped at three locations. 11 (see FIG. 1), the number is not limited to three, and may be appropriately one or two or more depending on the shape of the workpiece W. The gripping mechanisms 11 arranged at three locations have the same configuration.

  As shown in FIG. 3, the gripping mechanism 11 houses the driving member 111 in which the wedge-shaped portion 111 a is formed, the driven member 112 that moves in the diameter-expanding direction by the driving member 111, and the driving member 111 and the driven member 112. A holder 113 and driving means 114 (FIG. 2) for driving the driven member 112 by reciprocating the driving member 111 are provided.

As shown in FIG. 4B, the drive member 111 has a cylindrical shape, and is provided with a wedge-shaped portion 111a having a flat surface formed at three points in the circumferential direction at the tip portion.
As shown in FIG. 4C, the driven member 112 has a substantially rectangular shape, and is arranged at three locations side by side in the circumferential direction. In the driven member 112, a slope portion 112a that fits the wedge-shaped portion 111a is formed on one outer surface, and a joint portion 112b that joins the gripped portion Wa is formed on the other inner surface.
The joint portion 112b is formed in an arc shape in a cross-sectional view so as to match the hole shape of the gripped portion Wa, but is not limited to this, and is not limited to this, such as a rubber member having a high coefficient of friction, an anti-slip material such as a knurl. Processing may be performed.

  The gradient portion 112a is formed with a flat surface so as to fit the wedge-shaped portion 111a made of a flat surface, and the joint portion 112b is formed in an arc shape in cross section so as to fit the gripped portion Wa of the workpiece W. However, the present invention is not limited to this, and may be appropriately determined in consideration of the weight of the workpiece W, the wear resistance of the sliding portion, the difficulty of workability, and the like. For example, the gradient portion 112a and the wedge-shaped portion You may form 111a in circular arc shape by sectional view.

As shown in FIG. 3, the holder 113 has a main body portion 113a that supports the drive member 111 so as to be reciprocally movable in the vertical direction of FIG. 3A, and a front end that is screwed and joined to the front end of the main body portion 113a. Part 113b (see FIG. 4A).
The holder 113 supports the drive member 111 so as to be reciprocally movable on the inner peripheral surface 113c of the main body 113a, and the driven member 112 is supported by the support portions 113d and 113e (see FIG. 3B) of the tip 113b. It is supported so as to be capable of reciprocating in the left-right direction (horizontal direction) of (a).

As shown in FIG. 2, the driving means 114 is configured such that a reciprocating driving means such as an air cylinder is connected to the driving member 111 so that the driving member 111 can reciprocate.
The gripping mechanism 11 moves the driven member 112 in the left-right direction in FIG. 3A by reciprocating the driving member 111 in the vertical direction in FIG. )), And a mechanism for gripping the workpiece W (see FIG. 2) by pressing the joint 112b of the driven member 112 of the gripped portion Wa of the workpiece W (see FIG. 4D).

As shown in FIG. 2, the three-axis moving mechanism 12 includes an X-axis direction moving mechanism 121 disposed on the support plate 22, a Y-axis direction moving mechanism 122 supported by the X-axis direction moving mechanism 121, And a Z-axis direction moving mechanism 123 supported by a Y-axis direction moving mechanism 122 via a bracket 124.
The three-axis moving mechanism 12 is configured in the same manner as the three axes. For example, in the X-axis direction moving mechanism 121, a guide rail 121a disposed in the X-axis direction and a movable movement along the guide rail 121a are disposed. Holder 121b.
With this configuration, the workpiece gripping device 1 can be moved freely in the three axis directions of the front and rear (X axis), left and right (Y axis), and vertical (Z axis) directions by the three axis moving mechanism 12. I support it.

  In the present embodiment, the triaxial moving mechanism 12 is adopted, but the present invention is not limited to this, and the degree of freedom is appropriately set in consideration of the positional relationship of the gripped portion Wa of the workpiece W. One or two axes may be used, and a moving mechanism provided with a rotating shaft may be employed.

  The movement restricting device 13 is configured in the same manner for the three axes, and is provided in the X-axis direction moving mechanism 121, the Y-axis direction moving mechanism 122, and the Z-axis direction moving mechanism 123, respectively. For example, the X-axis direction moving mechanism 121 employs a lock mechanism that clamps the guide rail 121a and restricts the movement of the holder 121b. However, the locking method in the movement restricting device 13 is not particularly limited, and various forms such as an air type and an electromagnetic type can be adopted.

With this configuration, the workpiece gripping device 1 can be held by the movement restricting device 13 so that the gripping mechanism 11 is locked and moved in a state of being aligned with the gripped portion Wa of the workpiece W.
For this reason, the workpiece gripping device 1 flexibly responds to various workpieces having different gripped portion Wa positions by adjusting the gripping mechanism 11 to a free position by a gripping portion positioning device 500 described later (see FIG. 5). be able to.

<Attitude control device>
As shown in FIG. 2, the posture control device 2 includes a fixed plate 21 that is fixed to the distal end portion 102 of the robot arm 101, and an elastic mechanism 3 that elastically supports the support plate 22 of the workpiece gripping device 1 with respect to the fixed plate 21. The displacement detecting means 4 of the support plate 22 and the posture detecting device 6 for detecting the posture of the workpiece gripping device 1 are provided.
In the present embodiment, the case where the posture detection device 6 is provided will be described. However, the present invention is not limited to this. When the workpiece W is positioned on the pallet 201 (FIG. 1) in a normal state, May not include the attitude detection device 6.

The fixed plate 21 is a member that serves as a base for supporting the support plate 22 and has a rectangular shape in plan view (see FIG. 1).
The support plate 22 is elastically supported by the fixed plate 21 via elastic mechanisms 3 (see also FIG. 1) disposed at the four corners. At the support plate 22, the posture detection device 6 is arranged at predetermined locations (three locations in the present embodiment) so that the gripping mechanism 11 can securely grip the predetermined locations (three locations in the present embodiment) of the workpiece W. It is installed.

  As shown in FIG. 2, the elastic mechanism 3 is attached to the support plate 22 in a direction away from the fixed plate 21 (downward in FIG. 2) by a coil spring 31 disposed between the fixed plate 21 and the support plate 22. Thus, the support plate 22 is elastically supported with respect to the fixed plate 21.

  In the present embodiment, the coil spring 31 is employed as the spring member of the elastic mechanism 3, but the present invention is not limited to this, and the torsion is possible as long as the load and the amount of deflection necessary for posture control can be secured. Various spring members such as a coil spring, a leaf spring, and a disc spring can be employed. Moreover, it is not limited to a spring member, A gas spring can also be employ | adopted.

  That is, according to the operation content of the workpiece gripping device 1, a suitable posture member is realized by appropriately selecting an appropriate spring member or gas spring in consideration of a load and a deflection amount (stroke) necessary for the posture control. . The spring member is suitable for applications that gradually increase the attitude control force because the load is proportional to the amount of deflection, and the gas spring can generate a constant load even if the amount of deflection changes. Suitable for applications that ensure a stable and constant attitude control force.

The displacement detection means 4 is a detection device that detects the displacement of the support plate 22 relative to the fixed plate 21, and a detection device such as a proximity sensor is used.
The displacement detection means 4 includes a first detector 41 and a first detected portion 41a for detecting the original position of the support plate 22, and a second detector 42 and a second detected portion for detecting the grip position by the workpiece gripping device 1. 42a, and a third detector 43 and a third detected portion 43a that detect excessive displacement of the support plate 22.

  With this configuration, the support plate 22 moves in the direction approaching the fixed plate 21 from the original position shown in FIG. 8, and when the second detected portion 42 a reaches the position of the second detector 42, the gripping position by the workpiece gripping device 1 is reached. If it is detected (see FIG. 9) and the support plate 22 passes the gripping position and the third detected portion 43a reaches the position of the third detector 43, the excessive displacement of the support plate 22 can be detected ( (Refer FIG.12 (c)).

  As shown in FIG. 2, the posture detection device 6 includes a support shaft 5 that is brought into contact with the workpiece W, a flexible member 5 a provided at the tip of the support shaft 5, and an exterior that allows the support shaft 5 to be retractable. The cylinder 61, the urging means 62 that urges the support shaft 5 in the direction in which the support shaft 5 is pressed against the work W, the contact detection means 63 that detects that the support shaft 5 is in contact with the work W, and the outer cylinder 61 are illustrated. 3 and an air cylinder 64 that moves in the vertical direction.

Here, the flexible member 5a may use, for example, rubber, foamed polystyrene, sponge, or the like to relieve the impact force when the support shaft 5 is brought into contact with the workpiece W and prevent damage to the workpiece W. it can.
The air cylinder 64 is a device for allowing the outer cylinder 61 and the support shaft 5 to escape upward so that the posture detection device 6 does not interfere with the workpiece W when positioning the gripping mechanism 11 in the workpiece gripping device 1. The support shaft 5 can come into contact with the workpiece W in a state where the tube 61 and the support shaft 5 are lowered.

  The contact detection means 63 is composed of a proximity sensor or the like, and moves by a predetermined movement amount S (see FIG. 9A) after the support shaft 5 contacts the workpiece W, and the front end surface of the outer cylinder 61 and the support shaft When the support shaft 5 comes into contact with the workpiece W by the detected portion 63a that has moved to the facing position in a state where the front end surface of the surface 5 is flush (see FIG. 10A), a predetermined movement amount is obtained. Detects movement.

  The biasing means 62 is not particularly limited, and a coil spring or the like can be adopted. However, the elastic coefficient of the biasing means 62 is smaller than the elastic coefficient of the coil spring 31 of the elastic mechanism 3 (the elasticity of the elastic mechanism 3). The coefficient is set to be larger than the elastic coefficient of the biasing means 62).

  With this configuration, as shown in FIG. 9, the coil spring 31 (see FIG. 5) is bent more than the movement amount S (see FIG. 9A) that moves after the support shaft 5 abuts against the workpiece W. The amount of movement S ′ (see FIG. 9B) is smaller.

The posture detection device 6 is supported by the bracket 124 and is disposed in the vicinity of the gripping mechanism 11 of the workpiece gripping device 1.
The posture detection device 6 can detect that the driven member 112 that grips the workpiece W is properly inserted into the gripped portion Wa of the workpiece W by the contact detection means 63.

  That is, when the tip 102 of the robot arm 101 (see FIG. 1) is brought close to the support shaft 5 in contact with the workpiece W and the tip 102 is moved further toward the workpiece W, together with the workpiece gripping device 1. The outer cylinder 61 moves downward in FIG. 3 so that the support shaft 5 is accommodated in the outer cylinder 61 against the urging force of the urging means 62, and the distal end surface of the outer cylinder 61 and the distal end surface of the support shaft 5 are surfaces. It comes into contact with the workpiece W together.

  At this time, at the tip of the gripping mechanism 11, the posture detection device 6 is placed on the gripping mechanism 11 so that the driven member 112 that grips the work W is properly inserted into the gripped portion Wa of the work W. It is arranged at an appropriate position and height.

  For this reason, the posture detection device 6 contacts the state where the front end surface of the outer cylinder 61 and the front end surface of the support shaft 5 are flush with each other by a predetermined amount of movement after the support shaft 5 contacts the workpiece W. By detecting by the detection means 63, it can be confirmed that the driven member 112 that grips the workpiece W is properly inserted into the gripped portion Wa of the workpiece W.

Next, operations when the workpiece gripping device 1 is mounted on the posture control device 2 and applied to the articulated robot 100 will be described with reference to FIGS. 6 to 12.
<Operation of elastic mechanism 3>
First, the operation of the elastic mechanism 3 will be described with reference mainly to FIGS. FIG. 6 to be referred to is a schematic front view showing the operation of the elastic mechanism 3 when the rigidity of the pallet on which the workpiece is placed is high. FIG. 6A is a diagram before the tip of the gripping mechanism 11 is inserted into the gripped portion. The state, (b) shows the state after the tip of the gripping mechanism 11 is inserted into the gripped part. FIG. 7 is a schematic front view showing the operation of the elastic mechanism 3 when the rigidity of the pallet on which the workpiece is placed is low.
In FIGS. 6 and 7, for convenience of explanation, the inclination of the workpiece W and the like are exaggerated, but in reality, the amount of deformation is very small.

  Here, the pallet 201 (see FIG. 1) may be in various forms depending on the purpose and application. For example, when the pallet 201 is made of a metal angle material or the like, the pallet 201 generally has high rigidity and is made of synthetic resin. Since the rigidity of the elastic mechanism 3 is low, the elastic mechanism 3 has different functions depending on the relationship between the urging force (elastic supporting force) of the elastic mechanism 3 and the rigidity of the pallet 201 as follows.

<When pallet rigidity is high>
When the rigidity of the pallet on which the workpiece is placed is high, the elastic mechanism 3 tends to operate so as to control the posture of the workpiece gripping device 1 in accordance with the posture of the workpiece W.
That is, as shown in FIG. 1, for example, when the elastic mechanism 3 tries to grip the workpiece W placed on the pallet 201 with the gripping mechanism 11, the workpiece W placed on the pallet 201 is moved to a predetermined position. When the workpiece is deviated or inclined, the posture of the workpiece gripping device 1 with respect to the workpiece W is controlled according to the amount of deviation due to this deviation or the like.

  Specifically, as shown in FIG. 6A, when the workpiece W has an inclination of an angle α, the robot arm 101 (see FIG. 1) moves the workpiece gripping device 1 to a predetermined position with respect to the workpiece W. When the tip of the gripping mechanism 11 is inserted into the gripped portion Wa of the workpiece W, the support plate 22 is rotated clockwise from the gripped portion Wa of the workpiece W according to the inclination angle α of the workpiece W. The moment M to be applied is applied reactively.

  Then, as shown in FIG. 6B, the moment M applied in this way absorbs the inclination of the angle α of the workpiece gripping device 1 with respect to the workpiece W flexibly as appropriate, and the support plate 22 according to the inclination angle α. By correcting the position and the inclination angle, the posture control device 2 can suitably control the posture of the workpiece gripping device 1 with respect to the workpiece W.

<When pallet rigidity is low>
When the rigidity of the pallet on which the workpiece is placed is low, the elastic mechanism 3 tends to operate so as to match the posture of the workpiece W with the workpiece gripping device 1.
That is, as shown in FIG. 1, for example, when the elastic mechanism 3 tries to grip the workpiece W placed on the pallet 201 with the gripping mechanism 11, the workpiece W placed on the pallet 201 is moved to a predetermined position. When the workpiece W is deviated or tilted, the misalignment or the like is corrected, and the workpiece W functions to match the posture of the workpiece gripping device 1.

  Specifically, as shown in FIG. 7A, when the distal end portion of the gripping mechanism 11 is inserted into the gripped portion Wa of the workpiece W, the elastic mechanism 3 is tilted by its urging force (elastic support force). In order to apply an urging force (pressing force) to the workpiece W placed on the pallet 201 (see FIG. 1) at an angle α, the workpiece W is rotated counterclockwise by bending or deformation of the pallet 201. Moment M 'is applied.

  Then, as shown in FIG. 7B, the moment M ′ applied in this way acts so that the posture of the workpiece W becomes α ′ smaller than the inclination angle α. The posture of the workpiece W can be adjusted to the workpiece gripping device 1 by suitably correcting the deviation from the workpiece W.

  In this example, the case where the workpiece gripping device 1 functions so as to face the workpiece W in the direction of reducing the bending and deformation of the pallet has been described. However, the posture control device 2 greatly increases the bending and deformation of the pallet. The workpiece gripping device 1 may function so as to face the workpiece W in the direction in which the workpiece W is directed.

  In the present embodiment, for the sake of convenience, the case where the rigidity of the pallet 201 is high and the case where the rigidity is low has been described separately. However, in actuality, the pallet 201 is not strictly distinguished. However, it is possible to control the workpiece gripping device 1 so as to face the workpiece W suitably by appropriately adjusting the biasing force of the elastic mechanism 3.

<Operation of workpiece gripping device>
The operation of the workpiece gripping apparatus 1 will be described with reference to FIGS. 8 is a state before the workpiece is gripped by the gripping device, FIG. 9 is a state where the support shaft is in contact with the workpiece, FIG. 10 is a state where the outer cylinder of the support shaft is in contact with the workpiece, FIG. FIG. 5 is a partial front sectional view showing a state where clamping is completed.

  From the state in which the workpiece gripping device 1 does not contact the workpiece W (FIG. 8A), the tip 102 of the robot arm 101 is brought close to the support shaft 5 in contact with the workpiece W (FIG. 9A). Further, when the tip 102 is moved by S in the direction approaching the workpiece W, as shown in FIG. 10A, the outer cylinder 61 moves downward along with the workpiece gripping device 1 in FIG. The outer cylinder 61 is accommodated in the outer cylinder 61 against the urging force of the urging means 62, and the distal end surface of the outer cylinder 61 and the distal end surface of the support shaft 5 are flush with each other and abut against the workpiece W.

  Then, the contact detection means 63 detects a state in which the front end surface of the outer cylinder 61 and the front end surface of the support shaft 5 are flush with each other. In other words, the contact detection means 63 detects that the support shaft 5 has moved by a predetermined amount of movement after contacting the workpiece W by the detected portion 63a that has moved to the facing position.

  On the other hand, as shown in FIG. 10B, the displacement detection means 4 detects the presence of the second detected portion 42a that has moved to the position where the second detector 42 that detects the grip position by the workpiece gripping device 1 faces. Detect. In this way, the posture control device 2 confirms that the workpiece gripping device 1 has been positioned at the regular gripping position.

  At this time, if the workpiece gripping device 1 is positioned at the regular gripping position, the driven member 112 that grips the workpiece W at the tip of the gripping mechanism 11 simultaneously has a predetermined gap δ (see FIG. 10A). ) And is properly inserted into the gripped portion Wa of the workpiece W.

  In this way, the attitude detection device 6 moves a predetermined amount after the support shaft 5 abuts against the workpiece W, and the state where the tip surface of the outer cylinder 61 and the tip surface of the support shaft 5 are flush with each other. By detecting by the contact detection means 63, it can be confirmed that the driven member 112 that grips the workpiece W is properly inserted into the gripped portion Wa of the workpiece W.

  Then, as shown in FIG. 11, the gripping mechanism 11 pushes the driving member 111 into the driven member 112 by the driving unit 114 in a state where the workpiece gripping device 1 is positioned in a predetermined posture with respect to the workpiece W. The workpiece W is moved (see FIG. 11A), and the workpiece W is gripped so as to press the driven member 112 of the gripped portion Wa of the workpiece W.

<Operation when the workpiece is excessively displaced>
The operation of the posture control device 2 of the workpiece gripping device 1 when the workpiece W placed on the pallet 201 in FIG. 1 is excessively displaced due to vibration or external factors will be described with reference to FIG.
The posture control device 2 detects the state by the posture detection device 6 and the displacement detection means 4 when the work W that cannot be posture-controlled by the elastic mechanism 3 is excessively displaced.

  When the workpiece W is excessively deviated from the predetermined placement state, as shown in FIG. 12A, when the tip of the gripping mechanism 11 tries to approach the gripped portion Wa of the workpiece W, the workpiece W Is excessively displaced, the tip of the gripping mechanism 11 cannot be inserted into the gripped portion Wa of the workpiece W, and the tip of the gripping mechanism 11 contacts the workpiece W.

  In the state where the tip of the gripping mechanism 11 is in contact with the workpiece W, the tip 102 of the robot arm 101 is moved so as to approach the support shaft 5 until it contacts the workpiece W, as shown in FIG. Thus, the support shaft 5 cannot be brought into contact with the workpiece W.

  For this reason, the contact detection means 63 cannot detect a state in which the support shaft 5 moves by a predetermined movement amount S and the front end surface of the outer cylinder 61 and the front end surface of the support shaft 5 are flush with each other. .

  The support plate 22 is detected by the second detected portion 42a that has been moved to a position where the second detector 42 faces by the displacement detection means 4 without detecting that the support shaft 5 is in contact with the workpiece W. Is detected to have moved to the workpiece gripping position.

  However, even if the displacement detection means 4 detects that the support plate 22 has been displaced to the workpiece gripping position by the second detector 42, the contact detection means 63 indicates that the support shaft 5 is in contact with the workpiece W. Since it is not detected, it cannot be determined that the workpiece gripping device 1 has been positioned at a normal position with respect to the workpiece W.

  For this reason, when the distal end portion 102 of the robot arm 101 is further moved, the posture control device 2 has moved to a position where the third detector 43 faces by the displacement detection means 4 as shown in FIG. An excessive displacement of the support plate 22 is detected by the third detected portion 43a.

  In this way, the posture control device 2 detects the excessive displacement of the support plate 22 by the displacement detection unit 4 in a state where the contact detection unit 63 does not detect that the support shaft 5 is in contact with the workpiece W. Thus, it is determined that the workpiece W is excessively displaced, and an excessive load generated when the workpiece gripping device 1 tries to grip the workpiece W can be detected and avoided in advance.

Next, the gripper positioning device 500 will be described in detail.
<Grip part positioning device>
FIG. 13 is a plan view of the gripper positioning device. FIG. 14 is a side view of the gripper positioning device. 15A and 15B are views showing the periphery of the engaging member having the engaging recess shown in FIGS. 13 and 14, wherein FIG. 15A is a plan view and FIG. 15B is a front view.

  As shown in FIGS. 5, 13, and 14, the gripper positioning device 500 includes a base unit (base) 510 installed on the floor F, and the base unit 510 includes the base unit 510. A workpiece gripping device positioning unit 520 is provided for positioning the workpiece gripping device 1 including the gripping mechanism 11 that can be switched between a state in which movement is permitted and a state in which the movement is restricted, on the base unit 510.

  The workpiece gripping device positioning unit 520 has support columns 521 and 521 that are erected on the upper plate 511 of the base unit 510, and the support plates 22 of the workpiece gripping device 1 are provided on the support columns 521 and 521. Guide posts (base side set portions) 522 and 522 that can be set on a cylindrical guide member (holding device side set portion) 221 are provided. Here, for example, setting A to B means that when A and B satisfy a specific relationship (positional relationship), both elements of A and B are integrated and the behavior is unified. . A and B are, for example, a holding device side set unit and a base side set unit.

  With this configuration, the work piece attached to the distal end portion 102 of the robot arm 101 (see FIG. 1) can be grasped by fitting the guide member 221 provided on the support plate 22 to the guide post 522 of the work grasping device positioning unit 520. The device 1 can be positioned with respect to the gripper positioning device 500.

  Here, the workpiece gripping device 1 and the base unit 510 can be positioned with a compact configuration via the columns 521 and 521. Further, it is possible to secure a wide space for moving the gripping mechanism 11 between the workpiece gripping device 1 and the base unit 510, and the degree of freedom of layout of the gripping portion positioning mechanism 530 described later on the base is increased. .

  The base unit 510 is provided with a gripping portion positioning mechanism 530 having an engaging recess (engaging portion) 531 that can be engaged with the gripping mechanism 11. The gripper positioning mechanism 530 moves the gripping mechanism 11 of the work W (see FIG. 2) by three-dimensionally moving the engaging recess 531 engaged with the gripping mechanism 11 that is allowed to move in the work gripping device 1. Depending on the type, the workpiece W has a function of positioning by moving it to a position corresponding to the gripped portion Wa (see FIG. 2).

  As shown in FIGS. 13 and 14, the gripper positioning mechanism 530 moves the engagement recess 531 in the X-axis direction and the first support mechanism 541 that supports the engagement recess 531 in the X-axis direction. An X-axis unit 540 having a first drive device 542 for causing the The first support mechanism 541 includes a first rail 543 extending in the X-axis direction and a first block 544 that is movably engaged with the first rail 543 via a rolling bearing (not shown). The 1st linear motion guide mechanism 545 provided with this is provided. The first rail 543 is fixed on the upper plate 511 of the base unit 510. A first support 546 is fixed to the first block 544. The first driving device 542 includes a first nut portion 547 (see FIG. 13) fixed to the lower surface of the first support portion 546, a ball screw 548 (see FIG. 13) screwed into the first nut portion 547, And a motor 549 that rotationally drives the ball screw 548, and the screw feed action of the rotating ball screw 548 can move the first nut portion 547, and thus the first support portion 546, in the X-axis direction. It has become.

  In addition, the gripper positioning mechanism 530 includes a second support mechanism 551 that supports the engagement recess 531 so as to be movable in the Y-axis direction, and a second drive device 552 that moves the engagement recess 531 in the Y-axis direction. Y-axis unit 550 having The second support mechanism 551 includes a second rail 553 extending in the Y-axis direction and a second block 554 movably engaged with the second rail 553 via a rolling bearing (not shown). The 2nd linear motion guide mechanism 555 provided with this is provided. The second rail 553 is fixed on the first support portion 546. A second support portion 556 is fixed to the second block 554. The second driving device 552 includes a second nut portion (not shown) fixed to the lower surface of the second support portion 556, a ball screw 558 (see FIG. 13) screwed to the second nut portion, and a ball screw. And a motor 559 (see FIG. 14) that rotationally drives the 558, and the second nut portion and thus the second support portion 556 are moved in the Y-axis direction by the screw feeding action of the rotating ball screw 558. Is possible.

  In addition, the gripper positioning mechanism 530 includes a third support mechanism 561 that supports the engagement recess 531 so as to be movable in the Z-axis direction, and a third drive device 562 that moves the engagement recess 531 in the Z-axis direction. Z-axis unit 560 having The third support mechanism 561 includes a third rail 563 extending in the Z-axis direction and a third block 564 movably engaged with the third rail 563 via a rolling bearing (not shown). The third linear motion guide mechanism 565 having the above is included. The third rail 563 is fixed to the side surface of the second support portion 556 along the vertical direction. Further, a third support portion 566 is fixed to the third block 564. The third driving device 562 rotates a third nut portion 567 fixed to the side surface of the third support portion 566, a ball screw 568 (see FIG. 14) screwed into the third nut portion 567, and the ball screw 568. The third nut portion 567 and thus the third support portion 566 are moved in the Z-axis direction (vertical direction) by the screw feeding action of the rotating ball screw 568. It is possible to make it.

  Here, the first support mechanism 541, the second support mechanism 551, and the third support mechanism 561 support the engagement concave portion 531 so as to be movable in the directions of the three axes of the X axis, the Y axis, and the Z axis orthogonal to each other. The supporting mechanism is configured. The first linear motion guide mechanism 545, the second linear motion guide mechanism 555, and the third linear motion guide mechanism 565 constitute a linear motion guide mechanism. Thus, since the support mechanism has the linear motion guide mechanism, the engagement recess 531 can be smoothly moved without play along the rail extending in the direction of the three axes.

  The first driving device 542, the second driving device 552, and the third driving device 562 constitute a driving device for moving the engaging recess 531 in the directions of the three axes. The drive device can control the movement of the engagement recess 531 by controlling the rotation shafts (not shown) of the motors 549, 559, and 569, and thus the rotation angle positions of the ball screws 548, 558, and 568. According to such a structure, it can respond | correspond reliably to the workpiece | work W in which the to-be-gripped part Wa (refer FIG. 2) was formed in the various positions which differ for every kind of workpiece | work which has a variation. Further, the three-dimensional orthogonal coordinate system is easier to grasp the spatial position than the polar coordinate system, and the work such as robot teaching is easier to perform, so the workability is improved.

  The gripper positioning mechanism 530 includes first blocks 544, second blocks 554, and third blocks 564, and thus stoppers 571, 572, and 573 that prevent over-movement of the engagement recess 531. According to such a configuration, even if a running abnormality occurs in each of the blocks 544, 554, 564, and hence the engaging recess 531, the movement of each of the blocks 544, 554, 564, and thus the engaging recess 531 is stopped. Since it is limited by 571, 572, 573, the workpiece gripping device 1 (see FIG. 5) and the gripper positioning device 500 can be protected.

  In addition, the gripper positioning mechanism 530 includes reference position detection units 581, 582, and 583 that detect reference positions in the X axis, Y axis, and Z axis directions of the engagement recess 531, respectively. Here, the reference position detectors 581, 582, 583 are limit switches, and come into contact with detected parts provided in the first support part 546, the second support part 556, and the third support part 566, A predetermined engagement portion reference position is detected. Furthermore, the gripper positioning mechanism 530 has an overrun detection unit that detects a movement limit position of the engagement concave portion 531 in the directions of the X axis, the Y axis, and the Z axis. Reference numerals 584 and 585 exemplify an overrun detection unit for detecting a limit position in the Y-axis direction, and an overrun detection unit for detecting a limit position in the X-axis and Z-axis directions is also provided. Yes. The gripper positioning mechanism 530 includes a guide member detection unit 586 that detects the guide member 221 of the workpiece gripping device 1 set on the guide post 522.

  As shown in FIG. 15, an engagement member 532 having an engagement recess 531 is attached to the attachment plate 535 provided at the upper end of the third support portion 566. Here, the engagement recess 531 is composed of a plurality of recesses 531a, 531b, and 531c having circular cross sections with different diameters according to a plurality of types of workpieces W (see FIG. 2). It comprises a plurality of members 532a, 532b, 532c having recesses 531a, 531b, 531c, respectively. The members 532a, 532b, and 532c are flange portions 533a, 533b, and 533c fixed to the mounting plate 535 by a screw member 536, and column portions 534a, 534b, and 534c formed on the upper surfaces of the flange portions 533a, 533b, and 533c, respectively. And recesses 531a, 531b, and 531c having predetermined depths are respectively formed in the center of the upper surfaces of the cylindrical portions 534a, 534b, and 534c.

  According to such a configuration, a plurality of recesses 531a, 531b, and 531c having different diameters can be prepared in advance so as to be adapted to a plurality of gripping mechanisms 11 having different sizes. Accordingly, even when the size of the gripping mechanism 11 (see FIG. 5) varies depending on the type of the workpiece W, it is possible to cope with it. However, the present invention is not limited to this, and the mounting plate 535 of the third support portion 566 is configured to be provided with an engaging concave portion having one concave portion corresponding to one kind of workpiece W. It may be.

  Next, a description will be given of a gripping unit positioning method in which the gripping mechanism 11 in the workpiece gripping device 1 is moved and positioned according to the type of the workpiece W using the gripping unit positioning device 500.

<Grip part positioning method>
First, the articulated robot 100 is driven to move the workpiece gripping device 1 attached to the tip 102 of the robot arm 101, so that the guide member 221 of the workpiece gripping device 1 is gripped by the gripping unit positioning device 500. It is fitted to the guide post 522 of the apparatus positioning unit 520. As a result, the workpiece gripping device 1 is positioned with respect to the gripper positioning device 500. When the guide member detection unit 586 detects the guide member 221, it is determined that the setting of the workpiece gripping device 1 to the gripping portion positioning device 500 has been completed.

  Subsequently, the gripping part positioning mechanism 530 provided in the base unit 510 moves the engagement recess 531 provided in the gripping part positioning mechanism 530 and engageable with the gripping mechanism 11 three-dimensionally, and thereby the tip of the gripping mechanism 11. Is inserted into the engaging recess 531, and the engaging recess 531 is engaged with the gripping mechanism 11. Here, the gripping mechanism 11 presses and grips the engaging recess 531 from the inside to the outside.

  Then, the gripping mechanism 11 is set to a state in which three-dimensional movement in the work gripping device 1 is allowed. Subsequently, the gripping portion positioning mechanism 530 moves the engaging recess 531 engaged with the gripping mechanism 11 to a position corresponding to the gripped portion Wa of the workpiece W according to the type of the workpiece W.

  Subsequently, the movement restricting device 13 restricts the movement of the three-axis moving mechanism 12, thereby setting (locking) the gripping mechanism 11 in a state in which the three-dimensional movement in the work grasping device 1 is restricted. Here, the gripping mechanism 11 releases the gripping of the engaging recess 531. When the workpiece gripping device 1 includes a plurality of gripping mechanisms 11, the above steps are repeated. Thereby, the gripping mechanism 11 in the workpiece gripping device 1 is moved and positioned according to the type of the workpiece W.

  Next, the gripping portion positioning mechanism 530 moves the engagement concave portion 531 away from the gripping mechanism 11 and moves the engagement concave portion 531 to the detection positions by the reference position detection portions 581 582, and 583, thereby making a predetermined engagement. Return to the reference position. Subsequently, by driving the articulated robot 100, the workpiece gripping device 1 attached to the tip portion 102 of the robot arm 101 is moved, and the workpiece gripping device 1 is moved from the workpiece gripping device positioning unit 520 of the gripping portion positioning device 500. And the workpiece gripping device 1 is moved back to a predetermined gripping device reference position.

  As described above, in this embodiment, the gripper positioning device 500 for positioning by moving the gripping mechanism 11 in the workpiece gripping device 1 according to the type of the workpiece W includes the base unit 510 installed on the floor F. The base unit 510 includes a workpiece gripping device 1 provided with a gripping mechanism 11 that can be switched between a state in which movement of the workpiece gripping device 1 is allowed and a state in which the workpiece gripping device 1 is restricted. A gripping device positioning portion 520 and an engagement recess 531 that can be engaged with the gripping mechanism 11 are provided, and the engagement recess 531 engaged with the gripping mechanism 11 that is allowed to move in the workpiece gripping device 1 is three-dimensionally moved. As a result, the gripping mechanism 11 is moved to a position corresponding to the gripped portion Wa of the workpiece W according to the type of the workpiece W and positioned. A gripper positioning mechanism 530, are provided.

According to the present embodiment, the gripping mechanism 11 provided in the workpiece gripping device 1 attached to the robot arm 101 is provided with a driving device for moving the gripping mechanism 11 to the robot or the workpiece gripping device 1. Instead, the position of the gripping mechanism 11 in the work gripping device 1 can be automatically changed by moving and positioning in accordance with the change in the type of the work W.
Therefore, it is possible to cope with various workpieces having variations while reducing the weight of the tip side of the robot arm 101.

Next, an embodiment in which a part of the configuration of the above-described embodiment is changed will be described with respect to the changed configuration (modified example). The same configurations and operations as those of the above-described embodiment will be omitted from the detailed description as being taken into the following embodiments, and differences will be mainly described.
<Modification>

  For example, the gripper positioning mechanism 530 may include a locking mechanism (not shown) that can be switched between a state in which the movement of the engagement recess 531 is allowed and a state in which the movement is restricted. If comprised in this way, after moving the engagement recessed part 531, it can be made to stop reliably in a predetermined position. Therefore, for example, when the engagement recess 531 is moved by a drive device that is difficult to control precisely, such as an air cylinder, the engagement recess 531 is stopped using the locking mechanism by detecting the predetermined position. Can do.

  In this case, the locking mechanism uses any one of an electromagnet, a gear drive control, a hydraulic control of the linear guide mechanism, a pneumatic control of the linear guide mechanism, and an electric control of the linear guide mechanism. , 554, 564 and by extension, the engagement recess 531 can be switched between a permitted state and a restricted state. Thus, by selecting and using the locking mechanism from those specifically presented, the blocks 544, 554, 564 and eventually the engagement recess 531 can be reliably moved to a predetermined position and stopped. it can.

  Further, in the above-described embodiment, when the gripped portion Wa is a concave portion such as a through hole formed in the workpiece W, and an inner type gripping mechanism that presses and grips the concave portion from the inside to the outside is employed. However, the present invention is not limited to this, and when the gripped portion is a convex portion such as a boss, the outer type of the collet chuck type that presses and grips the convex portion from the outside to the inside. A gripping mechanism can also be employed.

  The outer-type gripping mechanism 11 ′ will be described with reference to FIGS. FIG. 16 to be referred to is a perspective view for explaining an outer-type gripping mechanism, in which (a) shows an external appearance and (b) is a cross-sectional view showing an internal structure. FIG. 17 is a cross-sectional front view showing the configuration and operation of the outer-type gripping mechanism, where (a) shows a state before gripping and (b) shows a gripped state. FIG. 18 is a partially exploded perspective view for explaining the configuration of the outer-type gripping mechanism. In the following description, since only the difference from the above-described embodiment is the gripping mechanism 11, detailed description of other configurations is omitted.

  As shown in FIGS. 16 and 17, the gripping mechanism 11 ′ includes a drive member 111 ′ having a wedge-shaped portion 111 a ′ and a gradient portion 112 a ′ that fits the wedge-shaped portion 111 a ′. A driven member 112 ′ that moves in the radial direction (see also FIG. 18), a holder 113 ′ that is provided in the drive member 111 ′ and supports the driven member 112 ′ so as to be movable in the axial direction, and a driven member 112 ′. And a collet bar 114a ′ connected to driving means 114 (see FIG. 2) for reciprocating and expanding and contracting the driven member 112 ′.

The drive member 111 ′ is a member that drives the driven member 112 ′ to expand and contract the diameter, and is fixed to the triaxial moving mechanism 12 side in the same manner as the holder 113 (see FIG. 3) in the above-described embodiment. .
As shown in FIG. 17 (a), the drive member 111 'includes a cylindrical barrel portion 111c' having a recess 111b 'formed therein, and a ring that is screwed into and coupled to the distal end portion of the barrel portion 111c'. A lid portion 111d 'having a shape and the wedge-shaped portion 111a' formed on the inner peripheral portion of the lid portion 111d 'are provided.

As shown in FIG. 18, the driven member 112 ′ is connected by a base portion 112 c ′ having a bowl shape so that three bodies are arranged in a circumferential direction with a gap therebetween to form a collet shape as a whole.
As shown in FIG. 17 (a), the outer peripheral portion of the driven member 112 'is formed with a gradient portion 112a' having a taper whose diameter is enlarged at the tip end side. The inner peripheral portion of the driven member 112 ′ is formed with a joint portion 112 b ′ with a gripped portion Wa ′ including a through hole adapted to a convex portion that is the gripped portion Wa ′.

As shown in FIG. 18, three holders 113 ′ are arranged side by side so as to form a gap in the circumferential direction, and form a ring shape as a whole in the drive member 111 ′ in the axial direction (FIG. 17). In the vertical direction). A ring groove 113a ′ is formed along the circumferential direction in the inner peripheral portion of the holder 113 ′, and a root portion 112c ′ of the driven member 112 ′ and a tip end portion 114b ′ of the collet bar 114a ′ are formed in the ring groove 113a ′. Buried.
The holder 113 ′ holds the driven member 112 ′ and the collet bar 114 a ′ so as to be integrally connected, and the driven member 112 ′ is slidable in the axial direction (vertical direction in FIG. 17) with respect to the drive member 111 ′. And is supported so as to be movable in the direction of diameter reduction and diameter expansion.

  The collet bar 114a 'has a rod-like shape, and includes a distal end portion 114b' whose diameter is increased in a disk shape, and a guide ring 114c 'that is slidably provided in the concave portion 111b' of the drive member 111 '. ing. The tip end portion 114b 'of the collet bar 114a' is embedded in the inner peripheral portion of the holder 113 'while being in contact with the root portion 112c' of the driven member 112 '.

With this configuration, as shown in FIG. 17A, the gripping mechanism 11 ′ moves the driven member 112 when the collet bar 114 a ′ is moved downward in FIG. 17A by the driving means 114 (see FIG. 2). Can be moved in the diameter increasing direction of FIG.
On the other hand, as shown in FIG. 17B, when the gripping mechanism 11 ′ moves the collet bar 114a ′ upward in FIG. 17B by the driving means 114 (see FIG. 2), the driven member 112 ′ is moved. The workpiece W ′ can be gripped by moving in the diameter reducing direction and pressing the joint 112b ′ of the driven member 112 ′ of the workpiece W ′ of the workpiece W ′.

  In the outer-type gripping mechanism 11 'described above, the driving member 111' is fixed so as not to move in the axial (vertical) direction, and the driven member 112 'is fixed to the driving member 111' by the driving means 114 (see FIG. 2). However, the present invention is not limited to this, and the driven member 112 ′ is fixed so as not to move in the axial direction and is driven by the driving means 114. The member 111 ′ may be moved in the axial direction with respect to the driven member 112 ′ to reduce the diameter of the driven member 112 ′ and may be gripped.

  FIG. 19 is a view showing the periphery of an engaging member having an engaging convex portion of a gripping portion positioning device used when the gripped portion of the workpiece is a convex portion such as a boss, and (a) is a plan view. (B) is a front view.

  As shown in FIGS. 19A and 19B, an engagement member 592 having an engagement convex portion 591 is attached to the attachment plate 535 provided at the upper end of the third support portion 566. Here, the engagement convex portion 591 is composed of a plurality of convex portions 591a, 591b, and 591c having circular cross sections with different diameters according to a plurality of types of workpieces W ′ (see FIG. 17). Reference numeral 592 includes a plurality of members 592a, 592b, and 592c having convex portions 591a, 591b, and 591c, respectively. Each of the members 592a, 592b, and 592c includes flange portions 593a, 593b, and 593c that are fixed to the mounting plate 535 by a screw member 536, and a convex portion 591a having a predetermined height on the upper surface of the flange portions 593a, 593b, and 593c. , 591b and 591c are formed.

  According to such a configuration, a plurality of convex portions 591a, 591b, and 591c having different diameters can be prepared in advance so as to be adapted to a plurality of gripping mechanisms 11 having different sizes. As a result, even when the size of the gripping mechanism 11 (see FIG. 5) differs depending on the type of the workpiece W ′, it is possible to cope with it. However, the present invention is not limited to this, and an engagement convex portion having one convex portion corresponding to one kind of workpiece W ′ is disposed on the mounting plate 535 of the third support portion 566. It may be configured.

  As described above, the engaging portion that can be engaged with the gripping mechanism is the engaging convex portion 591 in the case of the outer type in which the gripping mechanism presses and grips the gripped portion of the workpiece from the outside to the inside. In the case of an inner type in which the gripping mechanism presses and grips the gripped portion of the workpiece from the inside to the outside, the engagement recess 531 can be formed.

  If comprised in this way, it can respond also when the holding | grip mechanism 11 is an outer type, an inner type, or these both types coexist. In addition, it is possible to handle a workpiece having a complicated structure.

  In addition, when the to-be-gripped part of a workpiece | work is a convex part, the said convex part is not limited to column shape, such as an above-described boss | hub, A rectangular parallelepiped shape (partition shape), such as a rib, may be sufficient. In this case, the gripping mechanism 11 ′ grips the workpiece by pressing inward from the outside so as to sandwich the two opposing faces of the rectangular parallelepiped convex portions such as ribs. The engaging convex portion of the gripping portion positioning mechanism that can be combined is formed in a shape corresponding to a rectangular parallelepiped convex portion such as a rib that is a gripped portion of the workpiece.

  As mentioned above, although this invention was demonstrated based on embodiment, this invention is not limited to the structure described in the said embodiment (a modification is included), The above-mentioned structure is combined thru | or selected suitably. In the range which does not deviate from the meaning, the structure can be changed suitably.

1 Work Gripping Device 11, 11 'Gripping mechanism (gripping part)
101 robot arm 221 guide member (gripping device side set part)
500 Grasping part positioning device 510 Base unit (base)
520 Work gripper positioning unit 521 Support column 522 Guide post (base side set unit)
530 Gripping part positioning mechanism 531 Engaging recess (engaging part)
541, 551, 561 Support mechanism 542, 552, 562 Driving device 543, 553, 563 Rail 544, 554, 564 Block 545, 555, 565 Linear motion guide mechanism 571, 572, 573 Stopper 591 Engaging protrusion (engaging portion) )
F Floor W, W 'Work Wa, Wa' Grabbed part

Claims (9)

A gripper positioning device for positioning by moving the gripper according to the type of workpiece in a workpiece gripper mounted on a robot arm and gripping various workpieces by a gripper.
A base installed on the floor;
A workpiece gripping device positioning unit that is provided on the base and positions the workpiece gripping device with the gripping portion that can be switched between a state in which movement of the workpiece gripping device is allowed and a state of restriction in the workpiece gripping device. When,
The engagement portion that is provided on the base and includes an engagement portion that can be engaged with the grasping portion and that is engaged with the grasping portion that is allowed to move in the workpiece grasping device is three-dimensionally moved. A gripper positioning mechanism that moves and positions the gripper to a position corresponding to the gripped part of the workpiece according to the type of the workpiece,
A gripping part positioning device comprising:   The gripping portion positioning mechanism includes a support mechanism that supports the engagement portion so as to be movable in directions of three axes orthogonal to each other, and a drive device for moving the engagement portion in the direction of the three axes. The gripping part positioning device according to claim 1.   The said support mechanism has a linear motion guide mechanism provided with the rail extended in the direction of the said 3 axis | shaft, and the block engaged so that the movement along the rail was possible via a rolling bearing. Item 3. The gripper positioning device according to Item 2.   The engaging portion is a convex portion in the case of an outer type in which the gripping portion presses and grips the gripped portion of the workpiece from the outside to the inside, and the gripping portion grips the gripped portion of the workpiece from the inside. The gripping part positioning device according to any one of claims 1 to 3, wherein the gripping part positioning device is a concave part in the case of an inner type that presses and grips outward.   5. The gripper positioning device according to claim 4, wherein the engagement portion includes a plurality of the convex portions and / or the concave portions having circular cross sections having different diameters according to a plurality of types of workpieces.   The workpiece gripping device positioning section includes a support column that is provided with a base side set portion that can be set on a gripping device side set portion provided in the workpiece gripping device and is erected on the base. The gripper positioning device according to any one of claims 1 to 5.   The gripping part positioning device according to any one of claims 1 to 6, wherein the gripping part positioning mechanism includes a stopper that prevents the engaging part from being over-movable.   The gripping part positioning mechanism has a locking mechanism that can be switched between a state in which the movement of the engaging part is allowed and a state in which the movement is restricted. The gripper positioning device described in 1. A gripping part positioning method for positioning by moving the gripping part according to the type of work in a work gripping apparatus that is mounted on a robot arm and grips various works by a gripping part,
The workpiece gripping device provided with the gripping portion that can be switched between a state in which movement of the workpiece gripping device is allowed and a state of restriction in a workpiece gripping device positioning portion provided on a base installed on the floor. Positioning step (a);
A step (b) in which a gripping portion positioning mechanism provided on the base is engaged with the gripping portion by three-dimensionally moving an engaging portion provided in the gripping portion positioning mechanism and engageable with the gripping portion; ,
Setting the gripping part in a state in which movement of the work gripping device is permitted;
A step (d) in which the gripper positioning mechanism moves the engaging part engaged with the gripper to a position corresponding to the gripped part of the work according to the type of the work;
Setting the gripping part in a state in which movement of the work gripping device is restricted;
When the workpiece gripping device includes a plurality of the gripping units, the step (f) of repeating the steps (b) to (e);
A step (g) in which the gripper positioning mechanism separates the engagement portion from the gripper and returns the engagement portion to a predetermined engagement portion reference position;
Separating the workpiece gripping device from the workpiece gripping device positioning section and returning the workpiece gripping device to a predetermined workpiece gripping device reference position (h);
A method for positioning a gripping part of a workpiece gripping apparatus, comprising:

Images