JPH0546869Y2 - - Google Patents

Description

[Detailed Description of the Invention] Industrial Field of Use This invention relates to a robot hand that is equipped with a mechanism that expands and contracts the interval between a plurality of workpiece holding members according to the size of the workpiece.

BACKGROUND OF THE INVENTION An example of this type of robot hand equipped with a plurality of workpiece holding members is disclosed in Japanese Utility Model Application Publication No. 62-22090.

This is a robot hand that suctions and holds workpieces such as rectangular four-lamp head lamps for automobile parts.
As shown in the figure, this robot hand 1 is equipped with suction tools 5 for holding a workpiece W at the bottom end of each bottom plate part 4 of a main body part 3 having a U-shaped cross section and attached to the tip of a robot arm 2. A plurality of rods 6 are provided vertically penetrating and movable up and down. Then, as the robot hand 1 descends, the suction tool 5 at the lower end is brought into contact with the upper surface of the workpiece W in order, starting with the rod 6 disposed at the position corresponding to the higher part of the workpiece W among the plurality of rods 6. At the same time, each rod 6, which is restricted from descending by contacting the workpiece W, rises relative to the bottom plate part 4, and all the rods 6, which are provided in plurality, rise. When a detector (not shown) detects that the suction tool 5 at the lower end of the rod 6 has been suctioned to the work W, the slide plate 7 that regulates the vertical movement of each rod 6 and fixes the rod 6 is operated, and the suction tool 5 at the lower end is activated. The rods 6, each of which has a tool 5 adsorbed to the workpiece W, are fixed in a state in which the workpiece W is held.

Problems to be Solved by the Invention However, in the conventional robot hand 1 described above, a suction tool 5 for holding a workpiece W is provided at the lower end of each rod 6 that is attached to the main body 3 so as to be able to move up and down. Therefore, each suction tool 5 can be moved and held by suction according to the height of the surface to which the work W is suctioned, but since the spacing between the suction tools 5 is fixed and cannot be changed, this robot hand 1, when attempting to hold multiple types of workpieces W with different sizes and shapes, for example, the workpieces W may be too small and only a portion of the multiple suction tools 5 can be suctioned, resulting in an unstable holding state. If the workpiece W is too large, the balance may be lost and the desired workpiece posture cannot be obtained. There have been problems such as the case where it does not match the uneven shape and comes into contact with the stepped portion, making it impossible to suction and hold it.

This idea was created in view of the above problems.
The object of the present invention is to provide a robot hand that can hold a workpiece in an optimal state by moving the interval between a plurality of workpiece holding members according to the size or shape of the workpiece.

Means for Solving the Problems As a means for solving the above problems, this invention provides a robot hand that has a robot attachment part that is attached to a robot arm and a hand body that holds a workpiece, in which the hand body is rotatably driven. a shaft, a rotary drive device that rotatably drives the rotary drive shaft, a plurality of driven shafts arranged parallel to each other and connected to the rotary drive shaft via transmission means to rotate, and eccentrically connected to each driven shaft. The workpiece holding member is attached and moves toward or away from each other as the driven shaft rotates, and a movement range regulating means restricts the range of movement of the workpiece holding members in the direction toward or away from each other. It is characterized by the presence of

Effect With the above configuration, when the size or shape of the work to be held is changed, when the rotary drive shaft is rotated in the forward and reverse directions by the rotary drive device,
The rotation of the rotary drive shaft is transmitted to the plurality of driven shafts, which rotate forward or backward, so that the work holding members move toward or away from each other. For example, when holding a larger workpiece, rotating each driven shaft in the forward direction via the rotary drive shaft will cause the workpiece holding members, which are mounted eccentrically with respect to each driven shaft, to move away from each other. This increases the gap between them, making it possible to hold large workpieces.Also, when holding smaller workpieces, rotating each driven shaft in the opposite direction via the rotary drive shaft allows the workpiece holding members to move closer to each other. The distance between the two parts is reduced, making it possible to hold small workpieces. In addition, when holding workpieces with different uneven shapes, by rotating the rotary drive shaft in the forward or reverse direction, the position of each workpiece holding member can be moved to a position where it can be held while avoiding the uneven step part of the workpiece. do.

Embodiments Hereinafter, embodiments of the present invention will be described based on FIGS. 1 to 6.

Figures 1 to 3 show a first embodiment in which the present invention is applied to a robot hand that magnetically attracts and holds a powder molded product, which is compression molded from a material containing iron-based metal powder as a main component, and transports it. The robot hand 11 has a robot attachment part 13 connected to the distal end of the robot arm 12 at a flange part 13a on the proximal end side, and
Support shafts 14, 14 are attached to a plate-shaped bracket portion 13b that projects horizontally in a U-shape from the distal end side of the support shafts 14, 14.
The workpiece W, which is a powder molded product, is suspended through the
and a hand body 15 that holds the hand.

The hand body 15 is supported by both support shafts 14, 14, which suspend the hand body 15 from the bracket part 13b of the robot mounting part 13.
A base plate 16 is provided horizontally with both sides fixed to the lower end of the base plate 16, and collars 17, 17 are fitted above the base plate 16 onto the outer circumferences of the shafts 14, 14, respectively. It has an upper plate 19 which is supported and whose upward movement is restricted by annular stoppers 18 fixed to each support shaft 14, respectively. Further, on the upper surface of the upper plate 19, a rotary actuator 20 having a built-in reducer and capable of switching between forward and reverse rotations is installed vertically with its output side facing downward. A drive shaft 21 extending from the output side of the drive shaft 20 vertically passes through the upper plate 19 and has a drive gear 22 attached to its lower end. A thin box-shaped gear case 2 is supported horizontally by six sleeve legs 23a on the board 16 side in the middle.
3, and on the outer periphery of the drive gear 22 in this gear case 23, six fan-shaped driven gears 24 each having meshing teeth on an arcuate portion engage the meshing teeth and vertically. Each of the six driven shafts 25 is rotatably housed by being rotatably mounted on the upper end side of each of the six driven shafts 25.
extends downward from the gear case 23 and is inserted into each of the sleeve legs 23a to be stopped from swaying. Rotation is transmitted through the drive gear 22 and each fan-shaped driven gear 24, and the rotation is driven in forward and reverse directions. and,
A crank-shaped eccentric holder 26 is attached to the lower part of the base plate 16 on the lower end side of the six driven shafts 25 so as to rotate together with each of the driven shafts 25 (to avoid cluttering the diagram). Eccentric holder 2
6, two of the six are omitted), and each eccentric holder 26 has an elevating shaft 27 connected to each driven shaft 2.
The driven shaft 25 is located eccentrically with respect to the rotation center of 5.
The upper part of the eccentric holder 26 is slidably inserted into the eccentric holder 26 so as to be vertically movable up and down. Further, an electromagnet 28 is attached to the lower end of each of the lifting shafts 27, which attracts and holds a workpiece W, which is a powder molded product, by magnetic force.
In addition, each lifting shaft 27 has a stopper 27 at the upper end.
a prevents it from falling downward and is normally held at the lower limit position by its own weight and the weight of the magnet 28, and the upper limit is defined by the lower large diameter portion 27b.

On the other hand, above the rotary actuator 20, an upper drive shaft 21a is vertically disposed, which is an upwardly extending drive shaft 21 that is decelerated and driven by the rotary actuator 20.
At the upper end of this upper drive shaft 21a, there are a rotary arm 29 with a dog 29a on the tip side and a rotary arm 30 with a dog 30a.
0 forms an angle corresponding to the rotation range of the drive shaft 21, and above both the rotation arms 29 and 30 there is a rotary arm that rotates in unison with the forward and reverse rotation of the upper drive shaft 21a. Each dog 29a, 30 of each rotating arm 29, 30
The rotary actuator 2 detects the approach of
Proximity switch 3 that stops rotational drive by 0
1 and 32 are supported on the rotary actuator 20 via a bracket 33.

Next, a case will be described in which the robot hand 11 of this embodiment configured as described above suctions and holds a fragile powder molded product before firing and transports it.

If there are two types of powder molded products, large and small, to be attracted and held by magnetic force, the robot hand 11 attached to the tip of the robot arm 12 moves the rotary actuator 2 according to the size of each powder molded product.
0 to rotate the drive shaft 21 of the hand body 15 in the forward or reverse direction, respectively. That is, when the powder molded product is large, the drive shaft 21 is rotated in the forward direction by the rotary actuator 20, and when the powder molded product is small, the drive shaft 21 is rotated in the forward direction by the rotary actuator 20.
Rotate 1 in the opposite direction.

An upper drive shaft 21a extending upwardly of the rotary actuator 20 rotates together with the drive shaft 21, and a dog 29a is provided at the upper end of the upper drive shaft 21a. When the rotating arm 29 reaches the predetermined position (the position indicated by the solid line in FIG. 3) where each of the electromagnets 28 holds the larger powder compact, one of the electromagnets 28 (the left side in FIG. 1) It is fixed so as to be closest to the proximity switch 31 of the dog 30.
When each of the electromagnets 28 reaches a predetermined position for holding the smaller powder compact (the position indicated by the two-dot chain line in FIG. 3), the other rotating arm 30 equipped with a It is fixed to the upper end of the upper drive shaft 21a so as to be closest to the proximity switch 32 (on the right in FIG. 1), and when the upper drive shaft 21a rotates in both forward and reverse directions, the dog 29a or the dog 30a By stopping the rotary actuator 20 when detecting the approach of A rotation range of the drive shaft 21 to be moved is defined.

Therefore, when the drive shaft 21 rotates forward,
Six fan-shaped driven gears 24 are each rotated counterclockwise in FIG. The driven shafts 25 of are driven to rotate at the same time. When each driven shaft 25 is rotationally driven, the eccentric holders 26 attached to rotate together with these driven shafts 25 rotate, so that the elevating shaft 27 provided on each eccentric holder 26 moves toward the driving shaft 21. The electromagnets 28 provided at the lower ends of the six elevating shafts 27 move in a direction that expands the electromagnets 28 to a predetermined position for holding a large powder molded product (see Fig. 3). When the rotary actuator 20 is moved to the position shown by the solid line, the proximity switch 31 detects the approach of the dog 29a of the rotary arm 29, issues a stop signal, and stops the rotary actuator 20. Furthermore, when the drive shaft 21 rotates in the reverse direction, the rotation of the drive gear 22 causes each of the fan-shaped driven gears 24 to rotate clockwise in FIG.
When the electromagnet 28 is rotated, the electromagnet 28 provided on each eccentric holder 26 via the elevating shaft 27
move in the direction approaching the axis of the drive shaft 21, and move to a predetermined position (indicated by a two-dot chain line in FIG. 3) for holding a small powder molded product, and the proximity switch 32 rotates. arm 30
The rotary actuator 20 is stopped by detecting the approach of the dog 30a and transmitting a stop signal.

6 located at the bottom end of the hand body 15.
When the electromagnets 28 complete their movement to predetermined positions according to the size of the powder molded product, the robot hand 11 descends vertically and approaches the powder molded product from above. The electromagnet 28 is attached to each lifting shaft 27 on the upper surface of the powder molded product.
When the lower ends of the hand body 15 come into contact with each other, each electromagnet 28 attracts the powder molded product and the hand main body 15 descends, since each lifting shaft 27 is provided so as to be slidable in the vertical direction relative to the eccentric holder 26. The lowering of each lifting shaft 27 is regulated and the sliding movement absorbs the impact when each electromagnet 28 comes into contact, thereby preventing damage to the powder molded product. Next, the robot hand 11 holding the powder molded product by suction rises to a predetermined height, moves to above the destination pallet, and then descends until the powder molded product suctioned and held comes into contact with the upper surface of the pallet. At this time, since each electromagnet 28 that attracts and holds the powder molded product is provided so as to be movable in the vertical direction by the lifting shaft 27, the impact when it comes into contact with the pallet is transferred to the lifting shaft 27.
is absorbed by the movement, and the powder molded product lands on the pallet without damage. Then, when the electromagnets 28 are de-energized, the held powder molded product is separated from the hand body 15 and placed at a predetermined position on the pallet in a predetermined posture.

As described above, in the robot hand 11 of this embodiment, the positions of the plurality of electromagnets that attract and hold powder molded products by magnetic force are movable, thereby making it possible to attract and hold powder molded products of different sizes. At the same time, since each electromagnet 28 is movably disposed in the approach direction of the robot hand when holding a powder molded product, there is no impact when each electromagnet 28 comes into contact with the powder molded product and the powder molded product held by suction is moved onto the pallet. It can absorb shock when placed, and it is possible to suction and hold fragile powder molded products before firing without breaking or damaging them and transfer them onto a pallet.

Therefore, in the past, the work of transferring easily-damaged powder molded products onto pallets was carried out manually by workers, but by using the robot hand 11 of this embodiment, the work can be simplified. Automation can be achieved, and as a result, the disadvantages that arise when a worker performs the simple task of transferring powder molded products onto a pallet for a long time, such as the dust generated because the powder molded products are not yet fired, can be avoided. This eliminates the need to work in a bad work environment where large quantities of powder are scattered, improving safety and health, and also prevents powder molded products from being damaged or damaged due to rough handling due to long hours of work. Problems such as disordered arrangement on a pallet can be solved, and the transfer work of powder molded products can be speeded up. Furthermore, if the powder molded product to be held by the robot hand is changed to a different size, the mounting angle of the rotating arms 29, 30 attached to the upper end of the upper drive shaft 21a should be adjusted. This has the advantage of being easier to deal with.

Moreover, FIGS. 4 to 6 show a second embodiment of the present invention, and this robot hand is different from the one in which the hand body was provided immovably relative to the robot mounting part in the first embodiment. In this embodiment, it is provided movably and is activated when it detects cases where it is unsuitable for new placement, such as when another powder molded product is placed on the top surface of the pallet to which the powder molded product is being transported. Components that are the same as those in the first embodiment are designated by the same reference numerals, and detailed explanation thereof will be omitted.

The robot hand 41 is composed of a robot attachment part 43 connected to the tip of the robot arm 12, and a hand body 15 that holds a workpiece W, which is a powder molded product.

The hand main body 15 includes a horizontally disposed board 16 and collars 17 and 17 above the board 16.
It has an upper plate 19 which is supported horizontally at a predetermined distance by interposing the upper plate 19, and on the upper surface of this upper plate 19, there is a rotary actuator that has a built-in speed reducer and can switch between forward and reverse rotations. 20
is mounted vertically, and a drive shaft 21 of the rotary actuator 20 extends to the lower surface side of the upper plate 19, and a drive gear 22 is pivotally attached to the lower end thereof. Further, on the outer periphery of the drive gear 22, six fan-shaped driven gears 24 each having meshing teeth on the circular arc portion are arranged on the upper end side of six driven shafts 25 arranged vertically. It is rotatably mounted on a shaft. Furthermore, a crank-shaped eccentric holder 26 is attached to the lower end of each of the driven shafts 25 that vertically passes through the base plate 16 and extends downward, so as to rotate together with each of the driven shafts 25. (Two out of six eccentric holders 26 are omitted to avoid complicating the diagram),
Each eccentric holder 26 is provided with an elevating shaft 27 inserted at a position eccentric to the rotation center of each driven shaft 25 so as to be vertically movable up and down in parallel with the driven shaft 25, and each elevating shaft 27 27
The lower end of the workpiece W, which is a powder molded product, is attached by magnetic force.
An electromagnet 28 that attracts and holds the is attached to each. Further, the rotary actuator 2
An upper drive shaft 21a having rotary arms 29, 30 attached to its upper end is vertically disposed above the rotary arm 29, 30, and detects the approach of the dogs 29a, 30a at the ends of the rotary arms 29, 30. Proximity switches 31 and 32 for stopping the rotary actuator 20 are supported on the rotary actuator 20 via a bracket 33.

On the other hand, the robot attachment section 43 is connected to the distal end of the robot arm 12 at a flange section 43a on the proximal end side, and has a pair of guide bars 44, 45 on both sides of the bracket section 43b on the distal end side.
are vertically inserted into holder portions 43c provided at two upper and lower positions on both sides of the bracket portion 43b so as to be slidable in the vertical direction, and one of the guide bars 44, 45 ( The guide bar 44 on the right side in FIG.
The lower surface of the guide bar 45 is brought into contact with the upper surface of the holder portion 43c to prevent it from falling downward, and the other (left side in FIG. 4) guide bar 45 is moved upwardly from the other holder portion 43c located above. The lower end of a cylindrical stopper 47 (see FIG. 6), which is fitted onto the outer periphery of the extended portion and whose upper portion is fixed to the upper end of this guide bar 45, is connected to the holder portion 4.
By coming into contact with the upper surface of the guide bar 3c, it is prevented from falling off downward, and the guide bar 45 is wound around the outer periphery of the guide bar 45 and disposed within the cylindrical stopper 47, and the upper surface of the stopper 47 and the Spring 4 compressed between the upper surface of holder part 43c
It is constantly urged upward with a resilient force set to a predetermined strength of 8.

Further, a plate-shaped dog 49 is fixed to the upper end of one of the guide bars 44, and a proximity switch detects the rise of the guide bar 44 when the dog 49 approaches and stops the operation of the robot hand 41. 50 is provided on the upper part of the bracket part 43b via a stay 51.

The lower end sides of the pair of guide bars 44, 45 extend downward from respective holder parts 43c, 43c located below the bracket part 43b, and the hand main body 15 is attached to the lower end of each of the upper plate 1.
9 and the substrate 16 on both sides, respectively, are inserted into the collars 17, 17, and
Stoppers 52 and 5 provided on the lower surface side of the substrate 16
2 to prevent it from coming off.

Further, the elastic force of the spring 48 disposed in the cylindrical stopper 47 at the upper end of the other guide bar 45 is determined by the weight of both the guide bars 44, 45 and the weight of the spring 48 attached to the guide bars 44, 45. The strength is set to a predetermined strength that is slightly smaller than the total weight of each component and the entire hand body 15. Therefore, by configuring as described above, the portion of the hand main body 15 is
It operates in the same manner as in the embodiment, and it is possible to attract and hold a plurality of types of powder molded products of different sizes, and also to reduce the shock and impact caused when the electromagnet 28 that attracts and holds the powder molded product comes into contact with the powder molded product. In addition to absorbing the impact when placing the powder molded product on a pallet at the destination and preventing damage to the powder molded product, in this embodiment, the hand main body 15 is moved through a pair of guide bars 44 and 45. By being movably attached to the robot attachment part 43, when the robot hand 41 suctions and holds a powder molded product on the hand body 15 and transports it, it can pick up another powder molded product, etc. on the upper surface of the pallet at the destination. In the event of an abnormality, such as when the molded powder remains unprocessed, the powder molded product that was sucked and held at the lower part of the hand body 15 on the way down after moving upwards on the pallet may remain on the pallet. When the hand body 15 comes into contact with a powder molded product, etc., the lifting shafts 27, 27 of the hand body 15
moves upward relative to the eccentric holders 26, 26 to absorb the impact upon contact.

Furthermore, when the large diameter portion 27b of each lifting shaft 27 reaches the upper limit of the lifting shaft 27, where it comes into contact with the lower end of each eccentric holder 26, the hand main body 15 is moved by the elastic force of the spring 48 provided at the upper end of the guide bar 45. Since the hand body 15 is urged to rise even by a small upward force, the impact is absorbed by the hand body 15 rising relative to the bracket 43. Damage to the powder molded product is avoided, and when only the robot mounting portion 43 is lowered by restricting the lowering of the hand body 15, the proximity switch 50 provided on the bracket portion 43b of the robot mounting portion 43 is activated. the guide bar 44
Detects the approach to the dog 49 provided at the upper end of the
In response to the occurrence of an abnormality, a stop signal is sent to stop the operation of the robot hand 41, and
Notify the operator of the occurrence of an abnormality by flashing an alarm or warning light. If the robot hand 41 is stopped due to an abnormality, the powder molded product on the pallet that is the cause of the abnormality may be removed, and then the robot hand 41 may be returned to its initial position and restarted.

Therefore, in this embodiment, the hand main body 15 is provided so as to be movable in the vertical direction on the robot mounting part 43 via the guide bars 44 and 45, so that the powder molded product held by suction can be moved onto the pallet where the powder molded product is transported. In the event of an abnormality, such as when another powder molded product remains unprocessed, the hand body 15 is restricted from descending and the hand body 15 is moved to the robot attachment part 4.
3, the occurrence of an abnormality can be detected and the operation of the robot hand 41 can be stopped. Therefore, the robot arm 12 and the robot hand 41 can be prevented from being damaged due to excessive load. Moreover, damage to the powder molded product held by the robot hand 41 can be avoided. Furthermore, since it is possible to detect the residual powder molded product at the conveyance destination, double loading can be prevented.

In both of the above embodiments, an electromagnet 28 is used as a workpiece holding member to magnetically attract and hold a powder molded product containing iron-based metal powder as a main component and compression molded before firing. As other workpiece holding members, various workpiece holding members can be used depending on the type of workpiece to be handled, such as a member held by negative pressure suction or a member held mechanically.

Effects of the invention As explained above, this invention provides a robot hand that has a robot mounting part that is attached to a robot arm and a hand body that holds a workpiece.
The hand main body includes a rotary drive shaft that is rotatably driven by a rotary drive device, a plurality of driven shafts that rotate by being transmitted with the rotation of the rotary drive shaft, and is eccentrically attached to each of the driven shafts and rotates with respect to each other due to the rotation of the driven shafts. The plurality of workpiece holding members are provided with workpiece holding members that each move in the direction of approaching or separating from each other, and a movement range regulating means that restricts the movement range of the workpiece holding members in the direction of approaching or separating from each other. By moving them toward each other or away from each other, it is possible to easily handle workpieces of different sizes and increase versatility. In addition, since the structure is simple, it is difficult to break down, easy to maintain and manage, and has the effect of reducing equipment costs.

[Brief explanation of the drawing]

1 to 3 show a first embodiment of the present invention, in which FIG. 1 is a front view of the robot hand, FIG. 2 is a side view, FIG. 3 is a cross-sectional view taken along the - line in FIG. 4 to 6 show the second embodiment, in which FIG. 4 is a front view of the robot hand, FIG. 5 is a right side view, FIG. 6 is a cross-sectional view taken along the - line in FIG. The figure is a cross-sectional side view showing a conventional robot hand. 11, 41... Robot hand, 12... Robot arm, 13, 43... Robot mounting part, 1
3a, 43a...flange portion, 13b, 43b...
...Bracket part, 14...Support shaft, 15...
...Hand body, 16... Board, 19... Top plate, 2
0... Rotary actuator, 21... Drive shaft, 21a... Upper drive shaft, 22... Drive gear,
24... Sector-shaped driven gear, 25... Driven shaft, 26...
...Eccentric holder, 27... Lifting shaft, 28...
Electromagnet, 29, 30...Rotating arm, 29a, 3
0a...Dog, 31, 32...Proximity switch, 4
3c...Holder part, 44, 45...Guide bar,
46, 47...stopper, 48...spring,
49...Dog, 50...Proximity switch, W...Work.

Claims (1)

[Claims for Utility Model Registration] (1) A robot hand having a robot attachment part that is attached to a robot arm and a hand body that holds a workpiece, wherein the hand body has a rotational drive shaft and a rotary drive shaft that rotationally drives the rotational drive shaft. A rotary drive device, a plurality of driven shafts arranged parallel to each other and connected to the rotary drive shaft via transmission means to rotate; and a plurality of driven shafts that are eccentrically attached to each of the driven shafts and that move toward or away from each other by rotation of the driven shafts. A robot hand comprising: workpiece holding members that move in directions that separate them; and movement range regulating means that restricts the range of movement of the workpiece holding members in the directions in which they approach or move away from each other. (2) A utility model characterized in that the hand body is movably provided to the robot attachment part via a guide member that guides movement of the hand body only in a direction parallel to the driven shaft. A robot hand according to registered claim (1).