JPH0740278A - Robot hand device - Google Patents

Abstract

PURPOSE:To provide a simple, highly raid, low-price robot hand device suited for a two-hole inserting operation such that a workpiece having two reference holes off a work-gripping finger portion is mounted on a jig having two reference pins that fit into the holes. CONSTITUTION:An axial cushioning mechanism 4 that cushions a work-gripping finger portion 6 against a robot arm 10 in the direction of an axis, a flexible rotary joint 3 that flexibly connects the finger portion 6 to the arm 10 in the direction of rotation, and an X-Y sliding mechanism 5 that is movable in X and Y directions which are perpendicular to the direction of the axis, are interposed between the robot arm 10 and the work-gripping finger portion 6. The X-Y sliding mechanism 5 is supported in such a way as to be movable in the X and Y directions, and includes a pair of plates 51, 57 at both ends that are pressed inward by the respective pairs of pushers 53, 54.

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a floating device interposed between an arm of an industrial robot and a work gripping finger part, and in particular, it is offset from a work gripping finger part b as shown in FIG. The present invention relates to a robot hand device suitable for a two-hole insertion work in which a workpiece a having two reference holes d located at a position is attached to a jig b having two reference pins c that fit with the workpiece a.

[0002]

[Prior Art] As a main prior art, Japanese Patent Publication No. 56-26531
The method using an elastic body as disclosed in the publication, etc.
There are methods such as an external force detection device and a control device using a displacement sensor or the like as disclosed in the publication such as 13793. As a problem due to the above technique, the one in Japanese Patent Publication No. 56-26531 is
It is difficult to apply, for example, biaxial insertion offset from the hand axis, other than work related to shaft insertion on the hand axis, and work other than in the direction of gravity is difficult. 5-13
In the method by the external force detection device and the control device using the displacement sensor or the like of the 793 publication, the device is generally expensive and it is often difficult in actual application. As means for solving these problems, as disclosed in Japanese Patent Laid-Open No. 2-311291, a combination of modules having independent functions such as compliance operation, shift operation, cushion operation, etc.,
In some cases, two holes could be inserted.

[0003]

Generally, horizontal articulated robots and Cartesian coordinate type robots have less freedom than vertical articulated robots, and in order to compensate for them, the mechanism of the hand device is complicated and expensive. . For the above reasons, a simple robot hand device is desired when applied to a vertical articulated robot. More specifically, in the prior art of uniaxial single hole insertion shown in FIG. 4 disclosed in Japanese Examined Patent Publication No. 56-26531, in the case of a method using an elastic body, at a position close to the end of the insertion member distant from the remote centering device or its position. The compliance is achieved by setting an actual rotation center at a position with an end and using an external force acting there to rotate the axis of the working member so as to coincide with the axis of the hole. However, the rotation center referred to here is located on the extension line of the axis of the remote centering device, and it is difficult to apply it to the insertion work at a position offset from this axis.

That is, even in the work in the direction of gravity as shown in FIG. 4, when the shaft 8 gripped by the workpiece gripping fingers (not shown) is to be inserted into the hole 13 having the chamfer 9 at the inlet, The combined insertion force of No. 8 is F3, which is a combination of the insertion force F1 and the horizontal centripetal force F2. Here, at the contact point between the chamfered portion of the hole and the shaft shown in FIG. 3, the combined insertion force F3 of the shaft is decomposed into the normal component force F4 and the tangential component force F5 with respect to the contact surface of the chamfered portion. . A tangential frictional force F6 is exerted by F4, but if F5 is larger than this, the shaft is inserted into the hole. To perform the insertion operation, the horizontal centripetal force of the remote centering device must be small F2 so that F5 is greater than F6. Furthermore, when the work direction of the floating mechanism is other than the gravity direction, the horizontal centripetal force F2 is affected by gravity, so depending on the work direction, the shape of the work member, and the surface condition of the fitting part, the horizontal direction F2 The centripetal force F2 also needs to be adjusted to an optimum value. However, the remote centering device commonly used at present does not have a simple mechanism for adjusting the horizontal centripetal force.

Next, in the conventional technique by force control as disclosed in Japanese Patent Application Laid-Open No. 2-311291, a control circuit, control software, etc. are required in addition to the force sensor unit, the gripping unit and the remote alignment device unit. In addition to being expensive, it is often difficult to apply because different controls are required depending on each case.
To solve this problem, Japanese Patent Laid-Open No. 2-311291 discloses a hand mechanism for inserting two holes by attaching a hand device in which complicated modules are stacked to a Cartesian coordinate robot. However, a hand device in which such complicated modules are stacked is bulky in the longitudinal direction, and it is difficult to apply it to transportation of heavy objects and insertion in the vicinity of the horizontal direction because of its rigidity and strength. Was not suitable as a hand. An object of the present invention is to insert a two-hole inserting work in which a work having two reference holes at positions offset from a finger portion for grasping a work is attached to a jig having two reference pins to be fitted with the work. Suitable for, simple structure,
Another object of the present invention is to provide an inexpensive robot hand device having high rigidity.

[0006]

Therefore, the present invention has solved the above-mentioned problems of the prior art by providing the robot hand device described in the claims.

[0007]
──

With this structure, the workpiece is positioned in the rotational direction with respect to the two reference holes that are offset from the finger portion by the wrist or the rotation mechanism of the robot, and the XY position is set.
The movable slide mechanism absorbs misalignment in the translation direction, the flexible rotary joint absorbs phase deviation in the rotation direction, and the axial cushion mechanism enables proper insertion and extraction operations, and the insertion and extraction loads are optimized. Also, the impact on the robot is mitigated, and it is suitable for 2 hole insertion work, the structure is simple,
It also became a highly rigid and inexpensive robot hand device.

[0008]

DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS The present invention will be described in detail below with reference to the attached FIGS. FIG. 1 (a) is a partially cutaway sectional view showing a configuration of a hand device of a robot according to an embodiment of the present invention. The hand device for a robot according to the present invention includes a finger portion 6 for the arm 10 between the robot arm 10 and the workpiece gripping finger portion 6, and an axial cushion mechanism 4 and an axial cushion mechanism for providing a cushion in the axial direction. 4, a rotation mechanism 2 fixed to the housing 1 fixed to the cushion shaft 41 and rotating the finger portion 6 around the Z-axis axis 7, and the finger portion 6 for each arm 10.
A rotary / floating mechanism including a flexible rotary joint 3 that is flexibly connected and an XY moving slide mechanism 5 that is movable in an XY direction perpendicular to the axial direction is provided, thereby providing a compliance function. The XY moving slide mechanism 5 includes a pair of plates 51 and 52 that are movably supported in the X and Y directions, respectively, and that are pushed inward at both ends by a pair of pressing devices 53 and 54, respectively.

The housing 1 is supported by two rectangular box-shaped axial cushion mechanisms 4 which are bolted to a base plate 10 'fixed to an arm 10 in the embodiment. A body 43 surrounding the cushion shaft 41 of the axial cushion mechanism 4 is bolted and fixed to the base plate 10 '. Between the main body 43 and the cushion shaft 41, an intermediate portion 44 projecting inward of the main body 43 and a large diameter portion 48 of the cushion shaft serve as a fulcrum, and slide bushes 45, 45, elastic members 42 and thrust washers 46, 47 are provided. When the large diameter portion 48 pushes the elastic member 42 via the thrust washers 46 and 47, the cushion shaft 41 is moved up and down.

The cushion mechanism 4 is provided parallel to the direction of the axis 7
The cushion shafts 41 are arranged in parallel, and the finger portion 6 supported by the second shaft 22 expands and contracts when receiving a force in the axial direction, and the second housing 11 and the housing 1 through the cushion shaft 41.
Has a high rigidity with respect to translation and all rotations in the axial direction other than the cushion operation direction. As a result, the insertion and extraction load in the axial direction is optimized, and the impact on the robot is mitigated.

The rotating mechanism 2 rotates a first shaft 21 fixed to the housing 1 and indirectly connected to a finger 6 having a finger 61 at one end via the following members around an axis line 7. A flexible rotary joint 3 is connected to a lower end of a first shaft 21 extending through the housing 1. The flexible rotary joint 3
A hub joined to the lower end of the first shaft 21 as shown in FIG. 1 (c).
12 and a hub 13 joined to the upper part of the second shaft 22, and a flexible member 31 installed between these shafts 21, 22 and hubs 12, 13 to transmit rotation. The hubs 12 and 13 support the flexible material 31 and serve to transmit rotation. The second shaft 22 penetrates the housing 1 and is a bearing in the second housing 11 fixed to the housing 1.
It is rotatably supported via 16 and 17. Flexible rotary joint 3
When the second shaft 22 in contact with the flexible member 31 is displaced in the rotational direction with respect to the first shaft 21, the deflection of the elastic body is utilized to absorb the phase shift around the axis 7.

The finger portion 6 supported by the second shaft 22 includes
An XY moving slide mechanism 5 is interposed. That is, the second axis
The first bearing member 55 fixed to 22 is movably supported in the X direction X as shown in FIG. 1 (b) and is in sliding contact with the plate 51 pushed inward by a pair of pressing devices 53 at both ends. , Board 51
Is in sliding contact with the second bearing member 56,
A plate 52 fixed to 56 is movably supported in the Y direction Y as shown by a dotted line in FIG. 1 (b) and has a pair of pressing devices 54 at both ends.
Is pushed inward by the third bearing member 57
And slide in the Y direction. The third bearing member 57 is fixed to the finger portion 6, the upper end surface 62 of the finger portion 6 is in sliding contact with the lower end surface 57 of the shaft housing 23 fixed to the second shaft 22, and the plates 51, 52 are provided.
Is moved against the pressing devices 53 and 54 by the gaps in the XY directions provided between the finger housing 6 and the inner surface of the shaft housing 23, the finger portion 6 is also moved at the same time. It is designed to have high rigidity.

The rotating mechanism 2 is a rotating mechanism for aligning a work having a reference hole with the phase of a mating reference pin, and enables work in processes having various reference pin phases. It may be omitted if the reference pin phase is one type or if it can be rotated by the wrist of the robot itself, and instead of the rotation mechanism 2, the first shaft 21 is not shown and is supported by the arm 10. It may be rotated by the wrist. Further, in the embodiment, since the XY moving slide mechanism 5 is provided close to the finger portion 6, the movement of the finger portion 6 in each of the XY directions is extremely light and easy, but due to space reasons, etc. It does not matter if the mechanisms are interchanged with each other. Further, although the pressing devices 53 and 54 are capable of adjusting the pressing force, they may be fixed pressing devices which are adjusted in advance. The finger portion 6 is a mechanism that is actuated by air pressure, and may have a gripping function in FIG. 1, but may have a hooking or sucking function, or a combination thereof.

The operation will be described below with reference to FIG. 2 which is a perspective view showing the work a and the jig b, and FIG. 3 which is an explanatory view showing a series of processes from the work a removal to the jig b mounting. By the rotation mechanism 2 attached to the robot so as to add a uniaxial degree of freedom, the work a and the finger portion 6 are
The workpiece a is gripped by aligning the phases in the direction of rotation about the axis 7 of the workpiece (step 101). The work a is conveyed onto the jig b (step 102), the rotation mechanism 2 aligns the phases of the rotation direction of the work and the jig (step 103), and the work is inserted into the jig.

At this time, the work a held by the robot is
If there is a positional deviation dX, dY in the XY directions of the axis of the reference hole d and the reference pin c of the jig (step 103), the positional deviation dX, dY is absorbed by the translation by the XY moving slide mechanism 5. When there is a phase shift dθ around the axis between the reference hole d of the work a and the reference pin c of the jig (step 104
) It is absorbed by the rotational movement of the flexible rotary joint 3. Step 105 shows the completion of insertion. In addition, when the work is inserted d and the reference pin c of the jig is tightly fitted, the insertion load makes it impossible to insert the work, or when the work cannot be made due to various interferences, the axial cushion mechanism 4 is used to move the housing. The finger portion 6 attached to this is flexible with respect to 1,
This operation can be detected by a sensor (not shown), and the robot can appropriately perform determination processing. In addition, the work a is the reference pin c
Even when the robot is pulled out from the shaft, the axial cushion mechanism 4 operates even if the pulling load cannot be pulled out by the same set pulling load, the sensor (not shown) detects it, and the robot can perform appropriate determination processing.

[0016]

As described above, in the present invention, the X axis,
The Y-axis and Z-axis have translational degrees of freedom and the rotation around the Z-axis has a degree of freedom, and the XY moving slide mechanism has a floating mechanism that has rigidity in two rotations of the degree of freedom of the Z-axis. A structure that is suitable for two-hole insertion work, such as attaching a work having two reference holes at positions offset from the finger for gripping the work to a jig that has two reference pins that fit with this The robot hand device is simple, has high rigidity, and is inexpensive. Moreover, it is easy to adjust the rigidity of the X- and Y-direction translational motion parts on a plane perpendicular to the insertion direction, and it is possible to insert two holes in directions other than the gravity direction.

[Brief description of drawings]

FIG. 1A is a partially cutaway sectional view showing a configuration of a hand device of a robot according to an embodiment of the present invention, and FIG.
2 is a cross-sectional view taken along line ZZ of FIG. 3, and (c) is a schematic exploded perspective view showing the flexible rotary joint 3.

FIG. 2 is a perspective view showing a work a and a jig b on which the hand device of the embodiment robot of FIG. 1 works.

FIG. 3 is an explanatory diagram showing a series of flows from taking out the work a to attaching it to the jig b.

FIG. 4 is an explanatory view showing a relationship of acting forces when the shaft 8 on which the hand device of the conventional robot works is inserted into the hole 13 of the work 7.

[Explanation of symbols]

 1. ． Housing 3. ． Flexible rotary joint 4. ． Axial cushion mechanism 5. ． XY movement slide mechanism 6. ． Finger part 51, 52. ． Plates 53, 54. ． Pressing device

─────────────────────────────────────────────────── ───

[Procedure amendment]

[Submission date] April 27, 1994

[Procedure Amendment 1]

[Document name to be amended] Statement

[Correction target item name] 0001

[Correction method] Change

[Correction content]

[0001]

The present invention relates to relates to a floating device is interposed between the arm and the workpiece gripping fingers of the industrial robot, to shown in Figure 3 in particular, position fingers b and offset work gripping It is suitable for a two-hole insertion work in which a workpiece a having two reference holes d in 2 is attached to a jig b having two reference pins c fitted with the workpiece a.
Such a hand device of a robot.

[Procedure Amendment 2]

[Document name to be amended] Statement

[Correction target item name] 0004

[Correction method] Change

[Correction content]

That is, even in the work in the direction of gravity as shown in FIG. 4, when the shaft 8 gripped by the workpiece gripping fingers (not shown) is to be inserted into the hole 72 having the chamfer 9 at the inlet, The combined insertion force of No. 8 is F3, which is a combination of the insertion force F1 and the horizontal centripetal force F2. Here, at the contact point between the chamfered portion of the hole and the shaft shown in FIG. 3, the combined insertion force F3 of the shaft is decomposed into the normal component force F4 and the tangential component force F5 with respect to the contact surface of the chamfered portion. . A tangential frictional force F6 is exerted by F4, but if F5 is larger than this, the shaft is inserted into the hole. To perform the insertion operation, the horizontal centripetal force of the remote centering device must be small F2 so that F5 is greater than F6. Further, when the work direction of the floating mechanism is other than the gravity direction, the horizontal centripetal force F2 is affected by the gravity, so that the horizontal direction F2 depends on the work direction, the shape of the work member, and the surface condition of the fitting portion. The centripetal force F2 also needs to be adjusted to an optimum value. However, the remote centering device commonly used at present does not have a simple mechanism for adjusting the horizontal centripetal force.

[Procedure 3]

[Document name to be amended] Statement

[Name of item to be corrected] 0005

[Correction method] Change

[Correction content]

Next, in the conventional technique by force control as disclosed in Japanese Patent Laid-Open No. 2-311291, the force sensor part, the grip part,
In addition to the remote centering device section, a control circuit, control software, etc. are required, which makes the device expensive, and it is often difficult to apply because different control is required depending on each case. To solve this problem, Japanese Patent Laid-Open No. 2-311291 discloses a hand mechanism for inserting two holes by attaching a hand device in which complicated modules are stacked to a Cartesian coordinate robot. However, a hand device in which such complicated modules are stacked is bulky in the longitudinal direction, and it is difficult to apply it to transportation of heavy objects and insertion in the vicinity of the horizontal direction because of its rigidity and strength. Was not suitable as a hand. An object of the present invention, a workpiece having a reference hole of the two locations in the position finger portion and offset workpiece holding, Ru <br/> attached to a jig having the reference pins of two locations mate with this, 2 as are suited to hole insertion operation, it is simple and is to provide a hand apparatus with high rigidity and less expensive robot structure.

[Procedure amendment 4]

[Document name to be amended] Statement

[Correction target item name] 0008

[Correction method] Change

[Correction content]

[0008]

DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS The present invention will be described in detail below with reference to the attached FIGS. FIG. 1 (a) is a partially cutaway sectional view showing a configuration of a hand device of a robot according to an embodiment of the present invention. The hand device for a robot according to the present invention includes a finger portion 6 for the arm 10 between the robot arm 10 and the workpiece gripping finger portion 6, and an axial cushion mechanism 4 and an axial cushion mechanism for providing a cushion in the axial direction. 4, a rotation mechanism 2 fixed to the housing 1 fixed to the cushion shaft 41 and rotating the finger portion 6 around the Z-axis axis 7, and the finger portion 6 for each arm 10.
A rotary / floating mechanism including a flexible rotary joint 3 that is flexibly connected and an XY moving slide mechanism 5 that is movable in an XY direction perpendicular to the axial direction is provided, thereby providing a compliance function. The XY moving slide mechanism 5 is a pair of bearing members which are movably supported in the X direction and the Y direction, and are pressed inward by the pair of pressing devices 53 and 54 at both ends. 57
including.

[Procedure Amendment 5]

[Document name to be amended] Statement

[Correction target item name] 0009

[Correction method] Change

[Correction content]

The housing 1 is supported by two rectangular box-shaped axial cushion mechanisms 4 which are bolted to a base plate 10 'fixed to an arm 10 in the embodiment. A body 43 surrounding the cushion shaft 41 of the axial cushion mechanism 4 is bolted and fixed to the base plate 10 '. Slide bush 45, 45 between the body 43 and the cushion shaft 41 becomes large-diameter portion 48 of the intermediate portion 44及 beauty cushion shaft projecting inward of the main body 43 as a fulcrum, the elastic member 42 and the thrust washers 46, 47 Is arranged, and the elastic member 42 is
When 48 is pushed through the thrust washers 46, 47, the cushion shaft 41 is moved up and down.

[Procedure correction 6]

[Document name to be amended] Statement

[Correction target item name] 0012

[Correction method] Change

[Correction content]

Second shaft 22WhenFinger part 6BetweenXY transfer
The moving slide mechanism 5 is interposed.XY moving slide machine
Structure 5, In Figure 1 (b)With arrow XX direction as shownOn the other handMovably
Supported and directed inward by a pair of pressing devices 53 at both ends
PressedThe plate 51, which is a bearing member, is fixed to the second shaft 22.
Sliding contact with the specified bearing member 55,
The plate 51 and the bearing member 55 form a bearing portion in the X direction.
Form. Then, the bearing member 52 isIn Figure 1 (b)arrow
With mark YY direction as shownOn the other handMovably supported and 1 at both ends
Pushed inward by a pair of pressing devices 54TabeAlling
ElementIs a boardSliding contact with 57 in the Y direction. Bearing memberso
is there57 is fixed to the finger portion 6 and the bearing member 52
And form the Y direction bearing portion. Bearing member 52
And the bearing member 56 are joined, and the bearing member 56 is
It is in sliding contact with the plate 51, which is a bearing member.On finger part 6
The end face 62 is the lower end face of the shaft housing 23 fixed to the second shaft 22.
Sliding contact with 59,It is a bearing memberPlate 51,57Axis Hauge
The gap between the inner surface of the ring 23 and each of the XY directions.
When moving against the pressing devices 53, 54, the finger portion 6 also
Moves at the same time, but has high rigidity against rotational movements in two directions
Is to have.

[Procedure Amendment 7]

[Document name to be amended] Statement

[Correction target item name] 0014

[Correction method] Change

[Correction content]

The operation will be described below with reference to FIG. 2, which is a perspective view showing the work a and the jig b, and FIG. 3, which is an explanatory view showing a series of flows from the work a removal to the jig b mounting. By the rotary mechanism 2 which is mounted so as to add a degree of freedom of the uniaxial robot, in phase with the rotational direction around the axis 7 of the work a and finger portion 6 ', to grip the workpiece a (step 101). The work a is conveyed onto the jig b (step 102), and the rotation mechanism 2 aligns the phases of the work and the jig in the rotating direction (step 103).
The work of inserting the work into the jig is performed.

[Procedure Amendment 8]

[Document name to be amended] Statement

[Correction target item name] 0016

[Correction method] Change

[Correction content]

[0016]

As described above, in the present invention, the X axis,
Y-axis, has a degree of freedom only in rotation around Namido and Z-axis of the Z axis, XY moving the slide mechanism by the floating mechanism which gave rigidity to the two rotation degrees of freedom or spite of Z-axis, work with two places reference holes in a position offset with workpiece gripping fingers, such as Ru attached to a jig having two positions of the reference pins mate with this, as are suited to two-hole insertion operation, The robot hand device has a simple structure, high rigidity, and is inexpensive.
Moreover, it is easy to adjust the rigidity of the X- and Y-direction translational motion parts on a plane perpendicular to the insertion direction, and it is possible to insert two holes in directions other than the gravity direction.

[Procedure Amendment 9]

[Document name to be amended] Statement

[Name of item to be corrected] Brief description of the drawing

[Correction method] Change

[Correction content]

[Brief description of drawings]

FIG. 1A is a partially cutaway sectional view showing a configuration of a hand device of a robot according to an embodiment of the present invention, and FIG.
2 is a cross-sectional view taken along line ZZ of FIG. 3, and (c) is a schematic exploded perspective view showing the flexible rotary joint 3.

[Fig. 2] From removing work a to mounting it on jig b
Explanatory diagram showing a series of flow of.

FIG. 3 is a diagram illustrating a case where the hand device of the embodiment robot of FIG . 1 works.
The perspective view which shows the workpiece | work a and the jig b.

FIG. 4 is an explanatory diagram showing a relationship of acting forces when inserting a shaft 8 on which a conventional robot hand device works into a hole 72 of a work 71 .

[Explanation of symbols] 1. ． Housing 3. ． Flexible rotary joint 4. ． Axial cushion mechanism 5. ． XY movement slide mechanism 6. ． Finger part 10. ． Arms 51, 57 . ． Plates that are bearing members 53, 54. ． Pressing device

[Procedure Amendment 10]

[Document name to be corrected] Drawing

[Name of item to be corrected] Figure 1

[Correction method] Change

[Correction content]

[Figure 1]

[Procedure Amendment 11]

[Document name to be corrected] Drawing

[Name of item to be corrected] Figure 3

[Correction method] Change

[Correction content]

[Figure 3]

[Procedure Amendment 12]

[Document name to be corrected] Drawing

[Name of item to be corrected] Fig. 4

[Correction method] Change

[Correction content]

[Figure 4]

Claims (3)

[Claims] 1. An axial cushion mechanism having a cushion in the axial direction between the arm of a robot and a finger portion for gripping a workpiece, the finger portion with respect to the arm, and a flexible portion rotatably rotatable about an axis. Via a floating mechanism including a flexible rotary joint connected to the arm and an XY moving slide mechanism that is movable in XY directions perpendicular to the axial direction so that the finger portion has a compliance function with respect to the arm. The XY movement slide mechanism includes a pair of plates that are movably supported in the X and Y directions, and that have a pair of plates at both ends that are pressed inward by a pair of pressing devices. Hand device. 2. The hand device for a robot according to claim 1, further comprising a rotation mechanism which is interposed between the arm of the robot and the finger portion and rotates the finger portion around an axis with respect to the arm. 3. The robot hand device according to claim 1, wherein the XY movement slide mechanism is provided in the vicinity of the finger portion, and the pressing device is capable of adjusting a pressing force.