JPH03136730A - Rotary type robot hand or tool - Google Patents

Abstract

PURPOSE:To fasten and manufacture many kinds of screws, or to control attitude of a workpiece without change of arrangement of a device by providing a change-over device, which is moveably arranged between a frame and a case, for locking rotational motion of radially oriented shafts when a positioning mechanism is operated. CONSTITUTION:In a normal state, a positioning mechanism 8 locks rotational motion of a case 4. In this state, a main shaft 2 is rotated by driving a main shaft drive mechanism, and the rotation of the main shaft 2 is transmitted to a radially oriented shafts 5 and respective tool holding shafts 6 via gears, and makes tools 7 rotate. Then, required machining or assembling operation is performed by approaching a tool 7 to a workpiece by using a robot. On the other hand, if the positioning mechanism 8 does not operate, the case 4 becomes rotatable about the main shaft 2, and a change-over mechanism 9 operates associated with the case 4, and the rotation of the radially oriented shafts is locked. Consequently, the main shaft 2 and gears attached to it rotate, but the radially oriented shafts 5 do not rotate. Therefore, the tool holding shafts 6 do not rotate, and the case 4 only rotates about the main shaft 2, and indexing of the tool holding shafts 6 is performed.

Description

DETAILED DESCRIPTION OF THE INVENTION [Field of Industrial Application] The present invention relates to an industrial robot hand or tool, particularly a rotary multi-axis robot hand or tool.

[Conventional technology and its technical issues]

Robots are widely used to save labor and improve efficiency on production lines for products and parts. This kind of robot has X axis,
For example, a tool is attached to the tip of a hand that can move in each direction of the Y-axis and Z-axis.

Regarding screw tightening for robots, please refer to Japanese Patent Application Laid-Open No. 60-221.
There is one shown in Publication No. 227.

In this prior art, a shaft is provided in the robot body so as to be freely rotatable around a horizontal axis, a housing is fixed to the tip of this shaft, and a nut runner is supported on each housing via a cylinder so as to be movable in the axial direction. .

However, in this configuration, the indexing of the tool and the rotation of the tool are driven by separate drive sources, so there is a problem that the mechanism becomes large and heavy. Furthermore, only one socket or driver bit can be attached to each nut runner, so bolts of various diameters and shapes can be tightened, and many types of screws can be tightened (for example, Phillips screws, flathead screws, etc.). There was a problem in that the sockets and driver bits had to be replaced each time when performing the following.

On the other hand, a rotary robot hand equipped with a plurality of tools of different shapes for gripping a workpiece so that any tool can be selected is disclosed in Japanese Patent Application Laid-Open No. 53-34268. In this prior art, a yoke is coupled to the tip of the arm, a plate with a yoke-shaped cross section is pivotally attached to the tip of the arm via a horizontal axis, and a clamping tool is attached to a bracket fixed to the plate in different directions at 45° increments. It was installed facing the direction.

However, in this prior art as well, indexing of the tool and rotation of the tool mounting shaft are performed by separate drive sources on the robot body side. In other words, when multiple hollow drive shafts are provided in the arm and the tool mounting shaft is rotated, the innermost hollow drive shaft is rotated by an actuator, and the rotation is transmitted via both helical gears and the socket shaft. When indexing the tool, another actuator rotates the outer hollow drive shaft, which is transmitted to the plate and bracket via two outer helical gears, and the plate and bracket are rotated about the horizontal axis. and rotated the bracket. For this reason, the mechanism was complicated and it was impossible to avoid increasing the size and weight of the device.

Furthermore, in this prior art, each tool is placed in the same vertical plane, and the entire hand rotates around the horizontal axis when indexing the tool, which increases the required rotation radius, which makes tool exchange time-consuming and large. There was a problem that an interference area was generated.

The present invention was devised to solve the above-mentioned problems, and its purpose is to be able to hold a wide variety of tools, to quickly index them in a small space, and to be able to index them quickly. To provide a small and lightweight rotary type robot hand or tool that can perform removal and rotation of the tool with a single drive source.

[Means to solve the problem]

To achieve the above object, the present invention provides a frame to be attached to a robot or the like, a case supported for relative rotation by a main shaft passing through the frame, and a main shaft drive mechanism provided on the frame on the opposite side of the case.

a radial shaft extending perpendicularly to the main shaft, including a gear meshing with a gear provided at the center of the main shaft in the case;
A plurality of mounting shafts each have gears that mesh with the gears provided on the radial shaft, a positioning mechanism provided on the frame that locks the rotation of the case in normal conditions, and a positioning mechanism movably arranged between the frame and the case. and a switching mechanism that locks the rotation of the radial axis when activated.

The present invention is applicable not only to a robot hand for attaching a tool, but also to a multi-axis tool itself.

[For production]

Attach the frame to a robot arm, etc., and attach a desired tool such as a driver bit, socket, drill, etc. to the attachment shaft.

Under normal conditions, the positioning mechanism works and the rotation of the case is locked. If the main shaft drive mechanism is driven in this state, the main shaft will rotate, and the rotation will be transmitted to the radial shaft and each mounting shaft via gears, causing the tool to rotate. do. Then, desired processing or assembly is performed by bringing the robot closer to the workpiece.

On the other hand, if the positioning mechanism is deactivated, the case becomes movable around the main shaft, and in conjunction with this, the switching mechanism is activated and the rotation of the radial shaft is locked. As a result, the main shaft and the gear attached to it rotate, but since the radial shaft does not rotate, the mounting shaft does not rotate, only the case rotates around the main shaft, and the mounting shaft is indexed.

When the switching mechanism is deactivated, the positioning mechanism is activated and the relative rotation of the case with respect to the main shaft is locked.

〔Example〕

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

1 to 3 show a first embodiment in which the present invention is applied to a multi-axis tool, and FIGS. 4 and 5 show a second embodiment in which the present invention is applied to a robot hand. There is.

A frame 1 is attached to the arm of a robot of a desired type, such as a SCARA type, a multi-joint type, or a crosshead type, and has a board part 1a and an arm part 1b rising from the end thereof.

Reference numeral 2 denotes a main shaft, which is arranged perpendicularly to the board 1a of the frame 1, and whose rear part is rotatably supported by a bearing 17 provided in the board 1a. In the first embodiment, the nut runner 3. In the second embodiment, a motor 3' is arranged, and each output shaft 30,30' is connected to a key 31,31'.
It is connected to the main shaft 2 via. Although not shown in the drawings, the nut runner 3 is equipped with at least a motor and a high-speed/low-speed transmission mechanism, preferably a variable rotation mechanism in addition to the above, like a known one.

4 is a case, and the nut runner 3 or the motor 3
# is placed on the opposite side. This case 4 has a cylindrical part 4a, a body part 4b whose diameter is larger than that of the cylindrical part 4a, and a multi-beveled part 4c extending from the lower end of the body part 4b. The main shaft 2 extends from the cylindrical part 4a to the center (bottom) of the multi-faceted part 4c, and the case 4 is supported by a bearing 18 provided in the multi-faceted part 4c so as to be rotatable relative to the main shaft 2. .

A plurality of (six in the drawings) radial shafts 5, 5 are disposed on the body 4b in a relationship perpendicular to the main shaft 2, and each radial shaft 5, 5
are rotatably supported via bearings 19, respectively. A main bevel gear 21 is located in the middle of the main shaft 2.
10, and a driven bevel gear 22 that constantly meshes with the main bevel gear 21 is attached to the inner end portion of each radial shaft 5,5.
And coaxially with this, another transmission bevel gear 23 is connected to the key 22.
It is fixed via 0.

On the other hand, holes 40, 40 for mounting a plurality of tools (six in the drawing) are formed surrounding the center of the multi-faceted portion 4c, and the radial shaft 5, 5 and the mounting shaft 6.6 is arranged at an angle of 45°,
Each is rotatably supported by a bearing 20. The inner end portion of each mounting shaft 6.6 is provided with the radial shaft 5.
, 5, and tool bevel gears 2 and 4, which are constantly engaged with the conduction bevel gears 23 of 5, are each fixed by a key 240.
Desired tools and tools 7, such as Phillips and minus screwdriver bits, drills, box wrenches, or workpiece holding tools such as claw chucks and suction chucks, are replaceably mounted on the mounting shafts 6, 6.

8 is a positioning mechanism that locks the relative rotation of the case 4 with respect to the main shaft 2 under normal conditions, and 9 is a switching mechanism that locks the rotation of the radial shafts 5 when the positioning mechanism 8 is activated.

To explain in detail, first, a movable platen 10 is arranged around the cylindrical part 4a of the case 4, and the movable platen 10 is connected to a plurality of guide bins 41 rising from the top surface of the body part 4b in parallel with the main shaft 2. The bias 25 supported on the top surface of the body is complimented.
The board portion 1a of the frame 1 is biased in the direction thereof. Therefore, the movable platen 10 is integrated with the case 4 in terms of rotation, and is free to move in the axial direction.

A positioning guide 11 is integrally provided on the periphery of the movable platen 10 via a body or a fixing screw, and the positioning guide 11 is perpendicular to the axis of each mounting shaft 6, 6. A v-groove 110 is formed at a position that aligns with the top. Two positioning members 12゜12 with V-shaped tips are fixed to the frame 1 at positions displaced by 180 degrees from each other, and the movable platen 10 is pushed up by a bias 25, as shown in FIGS. 1 and 4. As shown, positioning members 12.12 are engaged with the V-grooves 110, 110 for indexing.

On the other hand, all of the radial shafts 5.5 or at least one set of radial shafts on the same axis are equipped with spur gears or similar gears at the outer end portions protruding from the case, as shown in FIGS. 1 and 4. The grooved member 13.13 is keyed. Locking pawls 14.14 are supported on the positioning guide 11 at positions corresponding to the grooved members 13.13 via springs 15.15 and hanging means.

In this embodiment, the locking pawl 14.14 is fitted into a guide groove formed in the positioning guide 11 so as to be movable only in the height direction, is suspended from a hanging bolt extending from the ceiling of the positioning guide 11, and is suspended by a spring 15. It is protruded by 15. Alternatively, the locking pawl 14.14 may be shaped like a window frame, the upper frame part may be fitted into a protrusion protruding from the positioning guide 11, and the spring 15 may be fitted between the lower surface of the protrusion and the lower frame. 50 is a cover plate fixed to the outer surface of the positioning guide 11.

Furthermore, in order to switch the tool indexing tool rotation, the frame 1 is provided with positioning members 12, 12 and 90, for example.
Cylinder mechanisms 16.16 are provided at the two displaced positions, as shown in FIGS. 2 and 5. The cylinder mechanism 16.16 includes a hydraulically or pneumatically actuated piston 160 and a rond 1 coupled to the piston 160.
61, a yoke portion 162 is provided at the lower part of the bushing rod 161, and a bushing bearing 163 is supported by this through a pin 164, and the bushing bearing 163 is always in contact with the upper surface of the movable platen 10. .

Note that the nut runner 3 or the motor 3' may be provided with a rotation angle sensor such as an encoder, thereby making it possible to index any mounting shaft. Also.

Main bevel gear 21, driven bevel gear 22, and conduction bevel gear 23
The gear ratios of the bevel gear 24 and the tool bevel gear 24 do not need to be the same, and may be changed.

Thereby, the torque of each mounting shaft 6, 6 can be varied. Furthermore, if rotational control of the tool is not required, a plug-shaped bracket 27 may be fitted into the hole 40 to mount the tool, as typically shown in FIG. 5, instead of the mounting shaft 6.

[Effect of the embodiment]

In the first embodiment, the frame 1 is attached to the arm of a robot or the like, and the whole body is moved in each direction of the X, Y, and Z axes. In the normal state, the movable platen 10 is pushed upward toward the swinging portion 1a of the frame 1 by the bias 25, and the positioning member 12 of the frame 1 is moved by the V of the positioning guide 11.
It is engaged with the groove 110. Therefore, the case 4 and the frame 1 are prevented from rotating relative to each other and are integrated.

When the nut runner 3 is driven in this state, the output shaft 30
The main shaft 2 is rotated via the main bevel gear 21, and the main bevel gear 21 is rotated. The rotation of the main bevel gear 21 causes the respective radial shafts 5, 5 to rotate via the driven gear 22 that meshes with the main bevel gear 21, and the transmission bevel gear 23 fixed thereto rotates, thereby causing the radial shafts 5, 5 to rotate via the driven gear 22 that meshes with the main bevel gear 21. The mounting shafts 6, 6 rotate, and the tools 7, 7 attached thereto rotate. Therefore.

For example, the workpiece W and the screw S are the arm part 1b of the frame 1.
If the frame 1 and the case 4 are vertically positioned, the robot lowers the entire frame 1 and case 4 and tightens the screws with a Phillips screwdriver bit.

On the other hand, if the screw S is a minus screw, the driving of the nut runner 3 is stopped and fluid pressure is supplied to the back of the piston 160 of the cylinder mechanism 16.

As a result, the piston 160 and bushing rod 161
When the movable plate 10 is moved in the axial direction, the movable plate 10 is pressed through the bush bearing 163, and the movable plate 10 and the positioning guide 11 are pushed down along the case cylindrical portion 4a. As a result, the positioning member 12.12 is removed from the groove 110, as shown in FIG.

The case 4 becomes rotatable relative to the frame 1. At the same time, due to the lowering of the movable platen 10, the positioning guide 1
The locking pawl 14° 14 carried at 1 also lowers and engages with the grooved member 13° 13 of the radial shaft 5.5. This locks the rotation of the radial axis 5°5.

If the nut runner 3 is driven in this state, the main shaft 2 and the main bevel gear 21 will rotate. However.

This is because the rotation of the radial shafts 5, 5 is locked.

The driven bevel gear 22 meshing with the main bevel gear 21 cannot rotate, and is in a state as if a clutch is engaged, and the main shaft 2 and the radial shaft 5.degree. 5 rotate integrally. As a result, the case 4, movable platen 10, and positioning guide 11 rotate around the main shaft 2. Due to this rotation of the case 4, the mounting shafts 6, 6 also rotate around the main shaft 2. This rotation is such that the mounting shaft 6 is 45° with respect to the inclined main shaft 2.
Because of the relative angle, the required rotation radius is much smaller than in the case of rotation around a horizontal axis, and the flathead screwdriver bit can be set in a vertical position in an extremely short time.

When the flathead screwdriver bit reaches the vertical position and the fluid pressure is released from the cylinder mechanism 16, the pressure on the bush bearing 163 is released, and the movable platen 1o and the positioning guide 11 are pushed back by the bias 25. This causes the locking pawl 14.14 to lock onto the grooved member 13.1.
Separated from 3.

At the same time, the positioning member 12 of the frame 1 fits into the V-groove 110, and the rotation of the case 4 is locked again. Therefore, accurate indexing can be performed regardless of the positioning accuracy of the nut runner 3.

Incidentally, the direction of tightening the screw is not limited to the vertical direction, but it goes without saying that it can be tightened in various directions such as the parallel direction (the axial direction of the flathead screwdriver bit in FIG. 1).

The same applies when applied to a robot hand as in the second embodiment, in which the positioning members 12 and 12 are at V in the normal state.
Since the case 4 is engaged with the grooves 110, 110, rotation is locked, and the main shaft 2 is rotated by driving the motor 3'.
- Main bevel gear 21 - driven bevel gear 22 - radial shaft 5 - transmission bevel gear 23 - tool bevel gear 24 transmission system rotates each mounting shaft 6, and the tool attached thereto rotates.

When indexing a tool, the movement of the motor 3' is stopped and the cylinder mechanism 16 is activated, and since the movable platen 10 is pushed by the bush bearing 163, the case formed by the positioning member 12 and the V-groove 110 is While the lock is released, the rotation of the radial shaft 5 is locked by the lock pawl 14 meshing with the grooved member 13. Therefore, by disabling the motor 3', the case 4 rotates around the main shaft 2, and the mounting shaft 6 rotates while maintaining an angle of 45° with respect to the main shaft 2. Therefore, tool exchange can be carried out in a very short time and with the area of interference kept to a minimum.

〔Effect of the invention〕

According to the present invention as described above, it is possible to perform various types of screw tightening, machining, or workpiece posture control without changing setups, and to select and replace tools in a very short time and eliminate interference areas. It can be done in a smaller size. In addition, the same drive source is sufficient for the rotation and indexing of the tool and its mounting shaft, and the same gear assembly is sufficient, making it possible to achieve smaller size and lighter weight.
Since the number of actuators on the robot side can be reduced accordingly, the robot structure becomes simpler.

Excellent effects such as cost reduction can be obtained.

[Brief explanation of the drawing]

Fig. 1 is a vertical side view showing an embodiment in which the present invention is applied to a screw tightening tool, Fig. 2 is a front view thereof, Fig. 3 is a longitudinal side view showing the state at the time of indexing, and Fig. 4 is a book FIG. 5 is a longitudinal side view showing an embodiment in which the invention is applied to a robot hand, and FIG. 5 is a front view thereof. l...Frame, 2...Main shaft, 3...Nut runner, 3'...Motor, 4...Case, 5...Radial shaft, 6...Mounting shaft, 7...Tool or tools, 8
...Positioning mechanism, 9...Switching mechanism, 10...
Movable plate, 12... Positioning member, 13... Grooved member, 14... Lock pawl, 21... Main bevel gear, 22
...Driven bevel gear, 23...Conduction bevel gear, 24.
...Hook gear for tools.

Claims (1)

[Claims] A frame attached to a robot, etc., a case supported for relative rotation by a main shaft passing through the frame, a main shaft drive mechanism installed on the frame on the opposite side of the case, and a gear installed in the middle of the main shaft inside the case mesh with each other. a radial shaft including a gear and extending in a direction perpendicular to the main shaft; a plurality of mounting shafts rotatably supported in a case with a required angular relationship with the radial shaft and having gears meshing with the gear provided on the radial shaft; , a positioning mechanism that is provided on the frame and locks the rotation of the case in a normal state, and a switching mechanism that is movably arranged between the frame and the case and locks the rotation of the radial axis when the positioning mechanism is removed. A rotary robot hand or tool characterized by: