JPH01188237A - Hand holder for assembly robot - Google Patents

Abstract

PURPOSE:To permit the chucking and screwing operations without applying an unreasonable deformation onto an annular work by spreading and contracting the leg part of a collet chuck by a collet chuck spreading/contracting mechanism and turning a pin-face ring by a turning mechanism. CONSTITUTION:A hand holder is lowered to position the leg part 2c of a collet chuck 2 in an annular work 50, and said hand holder is stopped. When a pushing-out rod 10 is retreated upwardly, a collet opening/closing shaft 6, interlocking ring 4, and a collet opening/closing ring 1 are integrally raised by the urging power of a chucking spring 8, and the leg part 2c is opened, and a working holding plane 2d is engaged with the inner surface of the work 50. The engaging power at this time suppresses the deformation of the work 50 and serves as a transportable engaging power. Then, the axis of the work 50 is allowed to coincide with the axis of a work assembly part 51, and then the rod 10 is lowered, and the chucking for the work 50 is released, and then the chuck 2 is revolved, and the pin-face projection 3d of a pin-face ring 3 is engaged with a pin-face groove 50a of the work 50.

Description

DETAILED DESCRIPTION OF THE INVENTION TECHNICAL FIELD The present invention relates to an assembly robot hand used for automatic assembly, and more particularly to a pot hand for tightening screws on an annular ring.

"Prior art and its problems" For example, the robot hand of an assembly robot chucks a screw-in annular holding ring (workpiece) used for fixing optical lens parts from a workpiece alignment pallet, transports it to the assembly position, and screws it into the mating part. Conventionally, a so-called collet chuck method was used.

FIG. 7 is an overall perspective view showing an example of this type of assembly robot 200. This assembly robot 200 is a scalar type assembly robot, and has two cylinders for raising and lowering the hand.
Hand holder 10 of robot hand 300 by 01
The extrusion rod cylinder 203 gives the collet of the hand holder 100 an opening/closing motion to hold and release the work, and the screw tightening motor 202 gives the work a rotational motion.

Figure 8 shows the hand holder to which the present invention applies! This is a conventional example of 00. The extrusion rod cylinder 203 is an extrusion rod.
110 is lowered and the rod 110 is pressing the idler 109 downward, the collet opening/closing ring 10
1 is pressed downward, and its Taber surface 101a is separated from the Taber surface 102a of collet +02. Therefore, the leg portion 102b of collet +02 closes due to its own elasticity. From this state, the entire hand holder 100 is lowered by the hand up/down cylinder 2, and the collet 102
The leg lθ2b of is positioned within the inner periphery of the annular workpiece 50. The workpiece 50 has a precision male thread 50b on its outer periphery, and has canine grooves 50a at two diametrically opposed locations that engage with protrusions of a special annular driver called a cannibal driver.

In this state, when the extrusion rod 110 retreats upward, the collet opening/closing ring 101 and the collet opening/closing shaft 106
and the collet opening/closing ring 101 is the chucking spring 1
It moves upward with the urging force of 08. Then, the Taper surface +01a of the open I+A ring +01 presses the Taper surface +02a of the collet 102 to open the leg portion 102b, and the annular workpiece 5
Check 0. The annular workpiece 5o is carried to a predetermined position by the assembly robot 200 in this chucked state,
Thereafter, it descends onto the workpiece assembly part 51. Thereafter, the collet 102 is rotated by the screw tightening motor 202 to tighten the screws.

However, in order to perform stable chucking and screw tightening with this conventional device, the chucking force must be strong, which may cause the annular workpiece 50 to be deformed. In particular, the annular annular workpiece 50 used for fixing the optical lens element is thin and easily deformed, and the screws on its outer periphery are precision screws in terms of optical performance, so even a slight deformation makes screwing impossible. This defect has been a major obstacle to automated assembly of optical lens elements.

``Object of the Invention'' In view of the problem with the conventional hand holder for assembly robots, the present invention aims to solve the problem of the problem with the conventional hand holder for assembly robots. However, the object of the present invention is to obtain a hand holder that can perform chucking and screw tightening operations without causing unnecessary deformation.

``Summary of the Invention'' As a result of research into chucking and screw-fastening rotation of an annular workpiece having a cannibal groove, the present invention has developed a system in which chucking for conveyance and positioning is performed using a conventional collet chuck method, and rotation for screw-fastening is performed using a conventional collet chuck method. was completed based on the idea that if the chucking force is used using the crab groove, the chucking force will be small and the workpiece will not be deformed.

That is, the present invention basically provides a hand holder for an assembly robot that chucks an annular workpiece having a pair of diametrically located cannibal grooves and a male thread on the outer periphery, and provides rotation for screw tightening to this annular workpiece. Separately, a collet chuck having legs that can be engaged and detached from the inner periphery of the annular workpiece, and a cannibal ring located on the outer periphery of the collet chuck and having a cannibal protrusion that engages with the cannibal groove of the annular workpiece, A feature of this collet chuck is that the legs of the collet chuck are expanded and contracted by a collet chuck expansion and contraction mechanism, and the crab ring is rotated by a rotation mechanism.

According to this mechanism, since the rotational driving force for screw tightening is given by the canimer ring, the chucking force by the collet chuck can be small, thereby preventing deformation of the annular workpiece caused by a large chucking force. Can be done.

Further, the present invention can also be configured as follows. That is, in a hand holder for an assembly robot that chucks an annular workpiece having a pair of diametrically located cannibal grooves and a male thread on the outer periphery and rotates the annular workpiece for screw tightening, the inner periphery of the annular workpiece is a collet chuck that has legs that can be engaged with and detached from the collet chuck and that can be rotated; a collet chuck expansion and contraction mechanism that expands and contracts the legs of the collet chuck; and a collet chuck expansion and contraction mechanism that allows the collet chuck expansion and contraction mechanism to move the canime ring to the annular workpiece side when the collet chuck is in the open state of the annular workpiece; In other words, an elastic means is provided for protruding from the surface.

According to this invention, chucking and rotation of the screw tightening mechanism can be performed reliably without applying unnecessary and harmful force to the annular workpiece during screw tightening.

"Embodiments of the Invention" The present invention will be described below with reference to illustrated embodiments. 1 to 6 show an embodiment of a hand holder for an assembly robot according to the present invention. Cylinder 20 for raising and lowering the hand in Fig. 7! The collet chuck 2 is rotatably supported by the holder cases 7a and 7b (hand holder!00) via a bearing 16. The collet chuck 2 is rotationally driven by a screw fastening motor 202 shown in FIG. 15 is bearing 16
This is an oil seal that prevents lubricating oil from dripping downward.

The collet chuck 2 has leg portions 2 that can be elastically expanded and contracted by a thin wall portion 2a at the bottom thereof and a plurality of (for example, three) slits 2b formed in the radial direction of the thin wall portion 2a.
It has c. The outer peripheral surface of this leg portion 2c is an annular workpiece 50.
It constitutes a work holding surface 2d that engages and disengages from the inner surface of the
The inner surface has a female annular tapered surface 2e whose diameter decreases upward.
is formed.

A collet opening/closing shaft 6 is inserted into the shaft portion of the collet chuck 2 so as to be movable in the axial direction. A collet opening/closing ring 1 having a male annular tapered surface 1a that engages with and disengages from a female annular tapered surface 2e of the collet chuck 2 is fixed to the lower end of the collet opening/closing shaft 6 by a fixing bolt 17.

A nut 14 is fixed to the upper part of the collet opening/closing shaft 6, and a chucking spring 8 made of a pressure spring is inserted between the nut 14 and the collet chuck 2 via washers 13a and 13b. . Therefore, the collet opening/closing shaft 6 and the collet opening/closing ring 1 are urged to move upwardly with respect to the collet chuck 2 by the chucking spring 8, and when no external force is applied to the collet opening/closing shaft 6, the male annular shape of the collet opening/closing ring 1 is The tapered surface 1a engages with the female annular tapered surface 2e of the collet chuck 2, and the leg portion 2
Expand the diameter of c.

The maximum diameter expansion amount of the leg portion 2c of the collet chuck 2 is regulated by a regulating ring 5 fitted around the outer periphery of the chuck 2. The restriction ring 5 limits the amount of diameter expansion of the leg portion 2c to a small amount so that the annular workpiece 50 is not deformed by the leg portion 2c.

An idler 9 is provided at the upper end of the collet opening/closing shaft 6, for example, as a non-rotation transmitting member, and the extrusion port 10 of the extrusion rod cylinder 203 (FIG. 7) is engaged with and disengaged from the idler 9. . This idler 9 is for preventing the rotation of the collet chuck 2 from being transmitted to the extrusion rod 10 when the collet chuck 2 rotates, and can be constituted by a bearing, for example.

The outer periphery of the collet chuck 2 is provided with the above-mentioned regulation ring 5,
A crab ring 3 located between the regulating ring 5 and the holder case 7b is further fitted. The regulation ring 5 and the cannibal ring 3 are rotated together with the collet chuck 2 by an interlocking ring 4 collinearly aligned with a fixing bolt 17 at the lower end of the collet opening/closing shaft 6, and the axis is a certain distance from the collet chuck 2. Supported to allow directional movement.

That is, a slit 5a and a slit 3a are formed in the regulation ring 5 and the crab ring 3, respectively, and the slits 5a and 3a match the slits 2b of the collet chuck 2 in the radial direction. The interlocking blade 4a is inserted therethrough. Therefore, the rotation of the collet chuck 2 is always controlled by the regulation ring 5, the crab ring 3, and the collet opening/closing ring 1.
This will be communicated to

On the other hand, the regulating ring 5 and the canine ring 3 can be moved in the axial direction of the collet chuck 2 within a range where the slits 5a and 3a do not interfere with the interlocking blades 4a. A compression spring 12 is interposed between the regulation ring 5 and the crab ring 3, and constantly biases the regulation ring 5 and the crab ring 3 in a direction to separate them, moving the regulation ring 5 upward and the crab ring 3 downward. It is energizing. Reference numeral 11 denotes a guide ball of this compression spring 12, whose upper end is fixed to the regulation ring 5 and whose lower end is movably fitted into the guide hole 3b of the crab ring 3.

Due to this compression spring 12, the regulating ring 5 is always at the rising end with respect to the collet chuck 2, and its slit 5a does not interfere with the interlocking blade 4a. On the other hand, the upper end of the slit 3a of the crab ring 3 is closed, and the lower end of the crab ring 3 is regulated at the position where the upper end closing portion 3c comes into contact with the interlocking blade 4a. The lower end of the crab ring 3 is provided with a crab protrusion 3d that engages with the crab groove 50a of the annular workpiece 50.

The present hand holder configured as described above operates as follows. First, the assembly robot 200 shown in FIG. 7 moves its robot hand 300 and sets the hand holder 100 on the center of a predetermined annular workpiece 50 arranged on a pallet. In this state, the holder cases 7a and 7b are at the height shown in FIG. Therefore, the male annular tapered surface 1a of the collet opening/closing ring l and the female annular tapered surface 2e of the collet chuck 2 are separated from each other. Therefore, no force for expanding the diameter of the leg portion 2c is applied to the leg portion 2c, and the leg portion 2c is maintained at the minimum diameter by the elasticity of the thin wall portion 2a (the amount of expansion/contraction of the leg portion 2C is (I), which is clearly shown in the figure). Although not shown, a gap is actually formed between the workpiece holding surface 2d of the collet chuck 2 and the inner surface of the regulation ring 5 at this time).

At this position, the hand holder 100 is lowered by the hand up/down cylinder 201, and the leg portion 2c of the collet chuck 2 is positioned within the inner diameter of the annular workpiece 50 and stopped. At this time, unless the crab protrusion 3d of the crab ring 3 is aligned with the crab groove 50a, the annular workpiece 5
0 surface, the canimer ring 3 deflects the compression spring 12 and escapes upward.

Next, when the extrusion rod cylinder 203 retracts the extrusion rod IO upward, the collet opening/closing shaft 6, the interlocking ring 4, and the collet opening/closing ring follow this and are moved by the urging force of the chucking spring 8! increases all at once. Then, the male annular tapered surface 1a and the female annular tapered surface 2e of the collet chuck 2 engage, the leg portion 2c opens, and the workpiece holding surface 2d engages with the inner surface of the annular workpiece 50. At this time, the opening amount of the leg portion 2C is controlled by the regulating ring 5.
The locking force is set so as not to deform the 0, but to provide sufficient locking force to transport it.

Also, at this time, the interlocking blades 4a of the interlocking ring 4 abut and engage with the upper end closing portion 3c of the crabmering ring 3,
hold in the raised position. At this time, the cannibal protrusion 3d is held in a non-meshing position with the cannibal groove 50a of the annular workpiece 50.

From the above state, the hand up/down cylinder 201 raises the hand holder 100 to the same level necessary for the annular workpiece 50 to separate from the pallet (FIGS. 3 and 4).

The robot hand 300 rotates the hand holder 100 while holding the annular work 50 in the collet chuck 2, aligns the axis of the annular work 50 with the axis of the work assembly part 51, and stops.

In this state shown in FIG. 3, the hand up/down cylinder 20
1, the hand holder 100 is moved 1sI, and the lowering is stopped at a position where the annular workpiece 50 being held lightly contacts the workpiece assembly part 51. Next, the extrusion rod cylinder 20
3, the extrusion rod 10 is lowered, and the collet opening/closing shaft 6, the interlocking ring 4, and the collet opening/closing ring 1 are pushed down together via the idler 9. Then, the contact between the male annular tapered surface 1a of the collet opening/closing ring 1 and the female annular tapered surface 2e of the collet chuck 2 is released, the diameter of the leg portion 2c is reduced, and the workpiece holding surface 2d and the inner surface of the annular workpiece 50 are brought into contact with each other. is disengaged. That is, the chucking of the annular workpiece 50 is released. Also, at this time, as a result of the interlocking ring 4 descending, the interlocking IF 1g4a is separated from the upper end closing portion 3c of the crab ring 3 and positioned below this, allowing the crab ring 3 to descend thereafter. The possible lowering amount of the cannimeling ring 3 is set to a minimum amount that allows the screw tightening of the annular workpiece 50 to the workpiece assembly part 51 to be completed.

Next, the collet chuck 2 is rotated by the screw tightening motor 202. Then, the interlocking g of interlocking ring 4
The crab ring 3, the regulation ring 5, the collet opening/closing shaft 6, and the collet opening/closing ring 1 rotate together via the shaft 4a. Since the crab ring 3 is urged downward by the compression spring 12, the crab protrusion 3d will eventually reach l1I.
The annular workpiece 50 is engaged with the cannibal groove 50a of the A workpiece 50 (FIGS. 5 and 6), and the continuous rotation of the collet chuck 2 even after the engagement causes the annular workpiece 50 to be screwed into the workpiece assembly part 51.

The downward force of the crab ring 3 on the annular workpiece 50 is only the biasing force of the compression spring 12, and since the leg portion 2c of the collet chuck 2 is separated from the annular workpiece 50 during this screw tightening operation, the annular workpiece There is no possibility that deformation or the like will occur in the precision male screw 50b on the outer periphery of the screw. FIG. 5 shows a state in which the annular workpiece 50 has been screwed onto the workpiece assembly part 51.

When the above screw tightening is completed, the robot hand 300 is raised by the hand up/down cylinder 2 and stops at a predetermined position, and then assembled and moved to a certain position on the pallet by the robot 200 to supply the next annular workpiece 50. Stop and start the next operation.

In the illustrated embodiment, the idler 9 is used in order not to transmit rotation to the extrusion rod 10, but in order to obtain the same effect, the interlocking ring 4 can be freely rotated with respect to the collet opening/closing shaft 6, but in the axial direction. may be supported so that they move together.

Furthermore, the gist of the present invention is to separately perform chucking and rotation of the annular workpiece 50 using a collet chuck and a crab-like chuck. Therefore, in the above embodiment, even if the configuration is such that only the crab ring 3 is rotated without transmitting rotation to the collet chuck 2,
Able to achieve purpose.

"Effects of the Invention" As described above, the assembly robot hunt holder of the present invention has the following advantages:
Since the annular workpiece having the cannibal groove is chucked by the collet chuck and the screw tightening rotation is performed by the cannibal ring, the chucking force can be reduced and deformation of the workpiece can be prevented. Therefore, the material of the annular workpiece,
It does not impose any restrictions on the shape, increases the degree of freedom in designing the shape of the workpiece, and enables stable production of inexpensive and highly accurate products.

In addition, by making the canimer ring movable in the axial direction with respect to the collet chuck, and by providing an elastic means that biases the canimer ring toward the annular workpiece when the collet chuck is in the open state of the annular workpiece, the canimer ring can be adjusted to the thread pitch of the annular workpiece. You can follow it and move it. Therefore, unnecessary deformation is not caused to the threaded portion of the workpiece or the entire workpiece when tightening the screws, the assembly is stable, and troubles in the assembly process can be eliminated.

[Brief explanation of the drawing]

Fig. 1 is a partially cutaway perspective view showing an embodiment of the hand holder for an assembly robot of the present invention, Fig. 2 is a sectional view showing a state before holding an annular work, and Fig. 3 shows a state in which an annular work is being held. FIG. 4 is a side view showing the relationship between the cannibal groove and the cannibal ring of the annular workpiece in the state shown in FIG.
Fig. 5 is a cross-sectional view showing the completed screw tightening of the annular workpiece to the workpiece assembly parts, Fig. 6 is a side view showing the relationship between the cannibal groove and the cannibal ring of the annular workpiece in the state shown in Fig. 5, and Fig. 7 is the assembled part. FIG. 8 is a perspective view showing an example of the overall structure of a robot, and FIG. 8 is a perspective view of main parts showing a conventional example of a hand holder for an assembly robot. 1...Collet opening/closing ring, 2-Collet chuck, 2a-Thin wall part, 2b-Slit, 2cm leg part 2c,
2d - work holding surface, 2e - female annular taper surface, 3...
- Crab ring, 3a-slit, 3b--guide hole, 3c--upper end closing part, 3d--cranime protrusion,
4--Interlocking ring, 4a series moving blade, 5-Restriction ring, 6
...Collet opening/closing shaft, 8...Chucking spring, 9
...Idle, 10--Extrusion rod, 12--Compression spring, 50--Annular workpiece, 50a--Cannibal groove, 50b--Male thread, 51--Work assembly parts,
100-・Hand holder. Patent applicant Asahi Optical Co., Ltd. Agent Kunio Miura Yoshimi Sasayama Figure 1 Figure 2 Figure 3 Figure 8

Claims (3)

[Claims] (1) In a hand holder for an assembly robot that chucks an annular workpiece having a pair of diametrically located cannibal grooves and a male thread on the outer periphery and provides rotation for screw tightening to the annular workpiece, the inner periphery of the annular workpiece is a collet chuck having a leg part that can be engaged and detached from the collet chuck; a crab ring that is located on the outer periphery of the collet chuck and has a crab protrusion that engages with a crab groove of an annular workpiece; a collet chuck that expands and contracts the leg part of the collet chuck. A hand holder for an assembly robot, comprising: an expansion/contraction mechanism; and a rotating mechanism for the crab ring. (2) In a hand holder for an assembly robot that chucks an annular workpiece having a pair of diametrically located cannibal grooves and a male thread on the outer periphery and provides rotation for screw tightening to this annular workpiece, the inner periphery of the annular workpiece is a collet chuck that has legs that can be engaged and detached from the collet chuck and that can be rotated; a crab ring having a crab protrusion that engages with the crab groove of the annular workpiece; a collet chuck expansion/contraction mechanism that expands and contracts the legs of the collet chuck; when the collet chuck is in the open state of the annular workpiece, the collet chuck expansion/contraction mechanism expands the cannime ring into an annular shape; A hand holder for an assembly robot, comprising: an elastic means for biasing movement toward a workpiece. (3) The hand holder for an assembly robot according to claim 1 or 2, wherein the maximum opening amount of the legs of the collet chuck is regulated by a regulating ring fitted to the outer periphery of the collet chuck.