JPS62166937A - Automatic tool-exchange arm device - Google Patents

Abstract

PURPOSE:To make it possible to independently mount and remove tools, by providing chucks for holding tools at the front ends of arms, means for displacing the arms in the direction of a rotary shaft, independently from each other, and an index means for rotating two arms integrally with each other. CONSTITUTION:Tool grip sections 32, 33 are formed in the front end parts of arms 5, 6 together with locating projections 30, 31, and tool holding chucks 36, 37 are rotatably provided by means of pins 34, 35. The retracting sections of press-rods 38, 39 confront the parts of guide holes formed in the arms 5, 6, and oppose the lateral surfaces of the stoppers 44, 45 or stopper holes 46, 47. Sensor rods 52, 53 pierce through a rotary shaft 4, a connecting member and rotary member 25a, and oppose proximity switches 56, 57 which are attached to the rotary member 25a by means of dogs 54, 55. Further the rotary shaft 4 is driven by an index rotary means.

Description

DETAILED DESCRIPTION OF THE INVENTION Technical Field of the Invention The present invention relates to an automatic tool changer for exchanging tools between a tool stocker and a machining axis of a machine tool. It relates to means for indexing in the direction and displacing each other independently in the direction of the axis of rotation.

BACKGROUND OF THE INVENTION With the automation of tool changing, various types of automatic tool changing devices have been developed.

A typical conventional tool changing device is of the type that rotates one rotating arm to simultaneously change the tool on the processing axis and the tool on the tool stocker side. In such an exchange device, different tools are exchanged at the same position on the tool stocker side, and the arrangement of tools on the tool stocker side becomes random every time a tool is exchanged, which complicates indexing control and makes it difficult for the operator. It is troublesome to replenish tools.

On the other hand, in models where the rotating shaft of the rotating arm itself reciprocates between the tool exchange position of the tool stocker and the tool exchange position of the processing axis, the automatic tool changer is large due to the reciprocating mechanism. and become structurally complex.

In addition, in machines where the machining axis of the machine tool itself moves to the tool exchange position of the tool stocker and the tool is changed by the movement of the machining axis, the tool indexing time is included in the tool exchange time, so the tool The replacement time becomes longer than necessary.

By the way, in the latter two types, since a certain specific tool is always mounted at a predetermined position of the tool stocker, the address of the tool stocker is a so-called fixed address. At such a fixed address, the number of the tool storage position matches the tool number on the numerical control program, so tools can be refilled or replaced in the tool stocker without any errors.

However, as already mentioned, in the latter two types, the operation of attaching and detaching the tool to the spindle and the operation of putting the tool in and out of the tool stocker must be time-shifted, and for this reason, the rotation arm etc. will temporarily wait at an intermediate position. Such a standby mechanism at an intermediate position complicates the tool changer.

OBJECTS OF THE INVENTION Therefore, an object of the present invention is to enable tools to be stored at fixed addresses in a tool stocker using a simple mechanism without prolonging tool exchange time or without providing a special intermediate standby mechanism. be.

Solution to the Invention Therefore, the present invention provides a tool attachment/detachment position of a tool stocker,
When viewed from above, the rotation axis and the processing axis of the rotation arm are arranged in a straight line, for example, and the rotation arm is composed of two arms, and these arms are arranged at right angles to the direction of rotation. They are arranged and are movable independently of each other in the direction of the rotation axis, for example in the vertical direction.

Therefore, each arm is in a state in which it can operate independently at the tool attachment/detachment position of the tool stocker or the tool exchange position of the machining shaft.

Structure of the Invention First, FIG. 1 shows an automatic tool changing arm device 1 of the present invention.
It shows the overall structure of.

This automatic tool exchange arm device 1 includes a tool stocker 2.
and the machining axis 3 of the machine tool, for example, at the lower end of the vertical rotation axis 4, as a rotating arm.
Two arms 5.6 are provided at right angles when viewed in plan. The rotating shaft 4 is rotatably supported by upper and lower bearings 9 inside a housing 8 attached to the frame 7 of the tool stocker 2, for example, in a state where it cannot be removed.

The rotary shaft 4 connects two piston rods 11 and 12 in a vertical direction by a connecting body 10 at its lower end.
Fixedly supported. These piston rods 11.
12, together with the cylinder tubes 13.14, constitute a guide means for independently displacing the arm 5.6 in the axial direction of the rotating shaft 4, and the respective cylinder tubes 13.
Inside 14, pistons 15, 16 are integrally formed. These cylinder tubes 13.14 are each closed at their lower end by a tail cover 17.18,
In addition, the piston rods 11 and 12 are slidably fitted on the head side, and each arm 5
．． It is fixed to the proximal end portion of 6. As shown in FIG. 2, these cylinder tubes 13 and 14 have a dovetail groove 19 formed on one side and a dovetail groove 20 formed on the other side.
The arms 5.6 are connected to each other in such a manner that the right angles of the arms 5.6 are movable only in the axial direction of the rotating shaft 4.

Also inside the cylinder tube 13.14, the piston 1
The chamber above 5.16, as shown in FIGS. The lower chamber likewise communicates via a passage 23.24 with an annular communication passage 28.29 of the rotary joint 25. This rotary joint 25
is fixed to the upper end portion of the housing 8, and fits into the rotating body 25a fixed to the upper end of the rotating shaft 4 in a state that allows the rotating shaft 4 to rotate.

These arms 5.6 have a semicircular arc-shaped tool gripping part 32.33 together with a positioning protrusion 30.31 at the tip.
A chuck 36,37 for holding a tool is rotatably provided near the chuck 36,37 by means of a pin 34,35. These chucks 36, 37 are connected to the arm 5, respectively.
．． By the pressure rod 38, 39 housed inside the 6,
It receives the biasing force of the biasing spring 'J7' 40.41, and is always biased in the channel king direction.

The rear end portion of the pressing rod 38.39 is connected to the arm 5.
．． facing the guide hole 42.43 formed in the stopper 44.45 or the stopper hole 46.6.
It corresponds to 47. The stoppers 44, 45 are slidable inside the cylinder tubes 13, 14, are biased upward by coil springs 50, 51, and are attached to the lower surface of the connecting body 10 at their distal ends. This corresponds to 48.49 per degree.

Note that these arms 5.6 are connected at their rear end portions to the lower end portions of sensor rods 52.53. These sensor rods 52,53 pass through the rotating shaft 4, the coupling body lO and the rotating body 25a, respectively, and are connected to proximity switches 56.
It corresponds to 57.

On the other hand, the rotating shaft 4 is driven by an indexing rotation means 58 shown in FIG. That is,
The index rotation means 58 is attached to, for example, the frame 7, and includes a servo motor 59 as a driving source. The rotation of this servo motor 59 is transmitted through a worm 60 and a worm wheel 61 to an intermediate shaft 62.
It is transmitted to the Geneva 63 by. Then, this Geneva 63 is moved by the Geneva wheel 65 by its roller 64.
The rotation is transmitted to the side drive shaft 66 as intermittent rotations every 90 degrees. Furthermore, this rotation of the drive shaft 660 is caused by the timing wheel 68 of the drive shaft 66 and the timing wheel 6 of the rotation shaft 4.
9 and the timing belt 67 wrapped around them.
As a result, the rotational force is transmitted to the rotating shaft 4 as rotational force for driving the arm 5.6 while indexing each 90 degrees. The intermediate shaft 62 and the drive shaft 66 are rotatably supported by bearings 70.71 on the frame 7, respectively, and their rotation is detected by rotation detection sensors 72.7.
3.74 respectively.

By the way, as shown in FIGS. 1 and 6, the aforementioned tool stocker 2 is, for example, a chain type one,
A plurality of tool pots 76 are rotatably supported by an endless chain 75, and a tool 77 is removably held together with a tool holder 78 inside the tool bot 76. That is, this chain 75 is movable along a pair of roller guides 80 by chain rollers 79 at both ends, and the tool bot 76 is rotated by a bracket 81 and its horizontal fulcrum shaft 82 at the link plate part. We support it as much as possible. This tool bot 76 has a tool 77 inside it.
The tool holder 78 is held in a positioned state, and its pull stand 83 is made detachable and prevented from being removed by a pair of pole plungers 84 fixed to the tool pot 76. The tool pot 76 is supported by a lower guide rail 85 when the chain 75 is moved, so that it can be moved while sliding. but,
Since the guide rail 85 is separated at the tool attachment/detachment position of the tool holder 1-2, the tool bot 76 is in a state where it can rotate about the fulcrum shaft 82.

Also, a holder 86 is attached to the rear end of this tool pot 76.
The cam follower 87 is rotatably supported by
It is adapted to fit inside the corresponding cam 88. The cam 88 is fixed to the lower end portion of a shaft 90 that is supported by a bearing 89 so as to be slidable in the vertical direction. This shaft 90 is connected to a piston rod 93 of a driving cylinder 92 by a connecting plate 91. Note that the bearing 89 and the driving cylinder 92 are fixed to the frame 7.

action of invention Next, a series of operations during tool exchange will be explained.

Initially, the arms 5.6 are both in the raised position, driven by the indexing rotation means 58, and are in the rotational position shown in FIG. Uke is ready to pick it up. When the tool 77 is picked up, the rotary shaft 4 is stopped at a position rotated counterclockwise by 20 degrees, for example, as shown by the imaginary line by the indexing rotation means 58. This rotational position is determined by the servo motor 5.
At this time, the Geneva wheel 63 and the Geneva wheel 65 are in the middle of being indexed by 90 degrees.

During this time, the tool stocker 2 is indexed by an indexing device (not shown) and moves a specific tool 77 to be newly mounted on the processing shaft 3 to the tool mounting/dismounting position. At this time, the cam follower 87 fits into the groove of the cam 88 and stops.

In this state, the driving cylinder 92 is connected to its piston rod 9.
3 and move the cam 88 upward, the tool pot 76, while holding the tool 77 and the tool holder 78, is moved counterclockwise around the fulcrum shaft 82, as shown in FIG. It rotates by 90 degrees and stops with the tool pot 76 facing downward, as shown by the imaginary line. In this way, the tool 77 and the tool holder 78
is in a downward state and faces the tool gripping part 32 of one arm 5.

Thereafter, the indexing rotation means 58 rotates the rotation shaft 4 at 2 in FIG.
The arm 5 fits into the tool holder 78 at its tool grip 32 in order to rotate clockwise by 0 degrees and return to its original position. In this state, since the arm 5 is still in the raised position, the chuck 36 is moved by the pressing rod 38.
is moved backward, the tool holder 78 is inserted into the holder, and the tool holder 78 is again subjected to the force of the biasing spring 40 and comes into contact with its outer periphery. In addition, when the pressing loft 38 is retreating, as shown in FIG. 3, the pressing loft 38 hits the perforation 48 and enters the inside of the stopper hole 46 that is being lowered. Thereafter, driving fluid is supplied to the passage 23, so the cylinder tube 13 moves downward while being guided by the piston rod 11. At this time, the arm 5 moves the tool holder 78 to the tool pot 7.
6 and hold it by its tool grip part 32. When the arm 5 is lowered, the stopper 44 is moved upward by the coil spring 50, so that the pressing rod 38 hits the side surface of the stopper 44 with its rear end face and cannot be moved back. Therefore, when the arm 5 descends, the chuck 36 can no longer be opened, and the tool 77 and tool holder 78 are held by the tool grip 32 and locked so that they do not fall.

Meanwhile, during this time, the machining shaft 3 is guided by the movement of the machine tool to the tool exchange position and is stopped there. Thereafter, the indexing rotation means 58 rotates the rotary shaft 4 by 90 degrees to stop the arm 5.6 at the position shown in FIG. It fits into the tool 77 to be removed. At this time, the rotation angle of 90 degrees is accurately determined by the Geneva wheel 63 and the Geneva wheel 65. In this state, the other cylinder tube 1 is similarly driven by the driving fluid.
4 is lowered, the arm 6 holds the tool holder 78 to be removed inside the tool gripping part 33 and pulls it out from the processing shaft 3, and the chuck 37 securely holds the tool holder 78 so that it does not fall. . Here, as well, as the arm 6 descends, the pressing rod 39 hits the side surface of the stopper 45 and cannot be moved back. In this way, the machining axis 3
The tool holder 78 is pulled out by the arm 6,
Inside the tool gripping portion 33, the tool is supported by a screwdriver 37 to prevent removal.

At this point both arms 5.6 are in the lowered position.

Next, the indexing rotation means 58 rotates the rotating shaft 4 counterclockwise by 90 degrees, and guides a new tool 77 onto the center line of the processing shaft 3, as shown in FIG. 7C.

In this state, the driving fluid is supplied to the passage 21, so the cylinder tube 13 moves up to move one arm 5 to the upper limit position, thereby installing a new tool 77 inside the processing shaft 3. do. At this time, a mechanism for holding the pull stud 83 of the tool holder 78 operates inside the machining shaft 3, and holds it in a state where it cannot be pulled out. Of course, in this state, arm 5 is at its upper limit,
Since the stopper 44 is in contact with the perforation 49, the pressing rod 38 is in a state where it can be retracted.

Subsequently, the index rotation means 58, as shown in the seventh diagram,
Furthermore, by rotating the rotary shaft 4 counterclockwise by 90 degrees, a new tool 77 fitted into the processing shaft 3 is removed.
Then, the tool gripping section 32 is released from the tool holder 78.

Thereafter, the machining shaft 3 returns to the machining position, and the new tool 77 starts the necessary cutting process. During this time,
The tool stocker 2 drives the chain 75 and the processing axis 3
A tool pot 76 corresponding to the tool 77 is placed in order to accommodate the tool 77 and tool holder 78 that have been pulled out.
The tool is guided to the tool attachment/detachment position and is placed in a downward position on standby.

Next, since the cylinder tube 14 rises, the arm 6
returns from the bottom to the top at the tool attachment/detachment position, and fits the tool 77 and tool holder 78 into the downward tool pot 7G. After that, the indexing rotation means 58 returns the rotation shaft 4 clockwise by 20 degrees, for example, and waits at the position shown by the imaginary line.

In this way, the tool 77 and tool holder 78 that have been attached to the machining shaft 3 are fitted into the tool pot 76 to be housed, and are held by the ball plunger 84 inside the pot 76 to prevent removal. .

Shortly, the cam 88 descends from the raised position, so the tool pot 76 rotates by 90 degrees about the fulcrum shaft 82, setting the tool 77 and tool holder 78 in a horizontal position. In this state, when the tool stocker 2 drives the chain 75 in the feeding direction, the tool pot 76 moves to a predetermined position while being guided by the guide rail 85.

In this way, the tool stocker 2 indexes the newly used tool 77 again, guides it to the tool attachment/detachment position, and prepares for the next tool exchange operation.

As described above, in the process of rotating counterclockwise, the arm 5.6 independently attaches and detaches the tool 77 to the tool stocker 2 and replaces the tool 77 to the machining shaft 3.
By the combination of the rotation every 0 degrees and the movement of the rotary shaft 4 in the axial direction, the movement is performed while temporarily stopping at an intermediate step position.

On the other hand, in the next tool change, the direction of rotation is opposite to the one described above.
The two arms 5.6 attach/detach and replace the tool 77 in the process of rotating clockwise by 90 degrees. Therefore, the indexing rotation means 58 drives the rotating shaft 4 in the opposite direction for each tool exchange operation.

Modifications of the Invention In the above embodiment, the chucks 36 and 37 for holding the tool are formed of claw-like members, but these parts may be replaced with other chuck mechanisms. Further, the guide means is not limited to the cylinder mechanism, and other sliding guide mechanisms may be used, and therefore, the driving source thereof is not limited to fluid pressure, but may be other driving means. Further, the indexing rotation means 58 may be of a type that regulates the amount of rotation of the rotating shaft 4 only from the amount of rotation of the reversible motor, without relying on the servo motor 59 and the Geneva mechanism, as in the embodiment. .

Effect of the invention The present invention provides the following unique effects.

Since the pair of arms are arranged at right angles, when one arm part is in the tool loading/unloading position or tool changing position, the other arm is in a position deviated from that position, and each arm rotates. Since they are guided independently in the axial direction, one of the tool attachment/detachment operations can be performed independently from the other. Therefore, for these arms, there is no need for an intermediate standby position or a movement mechanism for the entire arm, and the support structure for the arms can be simplified accordingly.

Further, when one arm is in the tool exchange position, the other arm is out of the tool attachment/detachment position, so that the tool stocker can be indexed during the tool exchange operation. Therefore, by always storing the tool in a specific tool pot, the tool is stored in a so-called fixed number system, and its indexing control is more effective than the conventional 180-degree, or linear, rotation arm. becomes easier.

[Brief explanation of drawings]

FIG. 1 is a partially cutaway front view of the automatic tool changing arm device of the present invention, FIG. 2 is a partially cutaway side view of two arm parts,
Fig. 3 is a partially cutaway side view of one arm, Fig. 4 is a plan view of the supporting parts of the two arms, Fig. 5 is a sectional view of the upper part of the rotating shaft and its indexing rotation means, and Fig. 6 is the tool. FIG. 7 is a side view of a portion of the stocker and a plan view showing the order of operation of the arms. 1. Arm device for automatic tool change, 2. Tool stopper 13. Machining axis, 4. Rotation axis, 5.6. Arm,
11.12...Piston rond, 13.14...Cylinder tube, 25...Rotary joint, 32.33...Tool gripping part, 36.37...Chuck for tool holding, 38.3
9...Press rod, 40.41...Biasing spring,
44.45... Stopper, 58... Index rotation means, 59... Servo motor, 63... Geneva, 65... Geneva wheel, 75... Chain, 76... Toolbot, 77... Tool, 78... Tool holder, 82... Fulcrum shaft, 92... Drive cylinder. Patent Applicant Sankyo Seiki Seisakusho Co., Ltd. Figure 4 Figure 6 Q7 Figure 7

Claims (1)

[Claims] In an automatic tool changer that transfers tools between a tool stocker and a machining axis using a rotating arm, there are two arms arranged at right angles to the rotating direction, and a tool holding tool provided at the tip of each arm. An automatic tool changing arm device comprising a chuck, a guide means for independently displacing each arm in the direction of a rotation axis, and an indexing rotation means for rotating the two arms together.