JP2970873B2 - Tool change arm of machine tool - Google Patents

Description

Description: BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a tool changing arm of a machine tool, and more particularly, to a tool changing arm of a machine tool for changing a tool set on a spindle of a machine tool and a tool magazine. .

[Related Art] Conventionally, there is known a machine tool capable of exchanging a tool between a spindle and a tool magazine. These machine tools have a tool changing arm for performing tool changing, and a tool set on a main spindle and a tool magazine are gripped by a pair of figures provided on a main body of the tool changing tool. It is exchanged by changing the position.

As a tool change arm of this type, a lever utilizing a link mechanism, for example, a rack member advances and retreats by rotation of a pinion shaft, and a lever that follows the movement thereof,
There are ones that open and close the gripping claws (JP-A-63-123646), and ones that open and close the gripping claws using a hydraulic cylinder or the like.

[Problems to be Solved by the Invention] However, such a tool change arm has a problem that the number of parts increases and the configuration becomes complicated due to the link mechanism and the hydraulic mechanism. In addition, in this type of replacement arm, the above disadvantages are increased because the interlock mechanism or the like is used for a member directly or indirectly connected to the gripping claws to brake the finger.

Furthermore, when a link mechanism is used (especially a link having many joints), rattling at the joints is liable to occur, and as a result, the movement of the finger may not be regulated accurately. Was. In such a case, there is a possibility that the tool cannot be grasped accurately, and as a result, the tool cannot be set on the main shaft or the like.

SUMMARY OF THE INVENTION It is an object of the present invention to provide a tool changing arm which solves the above-mentioned problems, has a small number of parts, has a simple structure, and can precisely regulate the movement of the finger pair.

[Means for Solving the Problems] A tool changing arm according to the present invention comprises a plurality of pairs of pairs of openable and closable fingers mounted on a tool changing arm body capable of turning around one axis. A tool exchanging arm for exchanging a tool set on a main spindle and a tool magazine by utilizing gripping by the finger pair and turning of a tool exchanging arm main body, wherein each of the finger pairs is replaced by the tool exchanging tool. A biasing means pivotally attached to the arm body so as to be rotatable around an axis parallel to the axis and biasing each finger pair in a direction in which a claw at the tip of the finger pair closes or opens. A finger driving cam that is mounted and reciprocates at a fixed angle around the axis is provided. One finger of each of the finger pairs receives the action of the cam, and opposes the urging force of the urging means. Opening direction Is provided with a passive portion that rotates in the closing direction, and the other finger abuts against the finger having the passive portion and rotates,
An engagement portion for rotating the other finger is formed.

[Operation] In the case of the tool change arm of the present invention having the above configuration, in which the finger pair is urged by the urging means in the direction to close the claw at the tip, when the finger driving cam is rotated by a predetermined angle, One of the finger pairs receives the movement of the cam at the passive portion, and rotates in the opening direction against the urging force. At the same time, the movement of the fingers is directly received by the engagement portions of the other fingers, and the fingers are rotated. In this way, each finger pair is opened by the action of the finger driving cam, and at this time, the spindle or the tool of the tool magazine can be interposed between the finger claws.

When the finger driving cam is rotated in the opposite direction, the cam does not act on the passive portion, and each finger pair is closed by the urging force of the urging means. At this time, each finger pair grips the tool if a tool is interposed therebetween in advance.

After gripping the tool, the tool exchange arm is turned and moved up and down as needed, so that the tool gripped by the finger pair can be set on the spindle or tool magazine. Next, when the finger driving cam is rotated by a predetermined angle in the same manner as described above, each finger pair is opened, and as a result, the tool is released.

On the other hand, in the case of the tool change arm of the present invention having the above-described configuration, when each finger pair is urged by urging means in a direction to open the claw at the tip, the finger is moved to the passive portion of one finger of each finger pair. The same function as described above can be achieved by providing a finger driving cam which operates and operates in the closing direction. In this case, the gripping of the tool by the finger pair is performed by the finger driving cam, and the release of the tool is performed by the urging means.

[Embodiment] In order to further clarify the configuration and operation of the present invention described above, a preferred embodiment of the tool changing arm of the present invention will be described below.

FIG. 1 is a view of a main part of a swivel arm as an embodiment of a tool changing arm according to the present invention viewed from below, FIG. 2 is a vertical sectional view of the swivel arm, and FIG. 4 is a perspective view showing a machining center to which an arm is attached, FIG.
The figure is a partial sectional view thereof. First, the entire machining center on which the swivel arm of the present embodiment is mounted is mainly a third
An overview is given with reference to the figures.

As shown in FIG. 3, in this machining center, a headstock 3 is supported by a column 2 fixed upright to a base 1. The headstock 3 is guided by a linear guide 4,
It is moved up and down by a shaft feed motor 5 and a feed screw 6. The table 7 provided on the base 1 is movable in the horizontal plane direction.

On the headstock 3, a spindle motor 8, a spindle 9 and a rotary tool magazine 10 are mounted. As the spindle 9 and the tool magazine 10 are the same as those disclosed in Japanese Patent Application Laid-Open No. 63-123646, the configurations thereof will be briefly described. See also). Spindle 9
Is a tool mounting portion 11 capable of detachably holding the tool T, and a tool release pin connected to the tool mounting portion 11 via a drawbar 12 to release the tool T by being pushed down.
13 and. The tool magazine 10 is provided with a plurality of holding pots which detachably hold the tool T and are usually in a horizontal posture, at the periphery of the turntable. Only the lowermost holding pot is rotated downward by 90 ° to take a vertical posture, and the turning arm A of this embodiment is ready for tool change. Selection of the tool T (disposition at the lowest position) is performed by rotation of the magazine motor 14.

The headstock 3 incorporates a tool changer TC for exchanging the tool T between the tool magazine 10 and the spindle 9. The apparatus includes a tool change drive motor (hereinafter, referred to as an ATC motor) 15, a swing arm A, and the like.

The swivel arm A of the present embodiment is configured around a swivel arm main body 16 and two pairs of openable and closable finger pairs 17 extending outward from the main body 16 at symmetrical positions with respect to the center axis. The tool T set on the spindle 9 and the tool magazine 10 is exchanged by using the gripping by the finger pair 17 and the turning of the tool exchange arm main body 16.

The details of the configuration of the swing arm A will be described later, and an outline of a mechanism that causes the movement of the swing arm A in the machining center will be described.

As a premise, first, the overall configuration of the tool changing device TC will be described with reference to FIG.

A tool change drive shaft (hereinafter, referred to as an ATC drive shaft) 18 of the tool changer TC is connected to the ATC motor 15 and is arranged vertically, and is rotatably supported on the headstock 3 by bearings 19 and 20. Have been. The ATC drive shaft 18 has four cams 21, 22, 23,
24 are provided.

On the other hand, on the side of the ATC drive shaft 18, a spline 25a is provided in about the lower half, and a hollow main shaft 25 provided with a flange 25b at the lowermost end,
It is arranged vertically. The hollow main shaft 25 penetrates a hole 26a of the lower machine frame 26 of the headstock 3 near its lower end, and is supported by the bush 27 so as to be able to rotate around the central axis and reciprocate along its axis. ing. The upper end of the hollow main shaft 25 passes through a through hole 28a formed in the upper machine frame 28 of the headstock 3, and this through hole 28a and the hollow main shaft 25
A support member 29 and a bush 30 are rotatably interposed between the two. The support member 29 is a substantially cylindrical member. The lower part of the center hole of the support member 29 is inserted with the upper part of the hollow main shaft 25 having a smaller diameter than the hole diameter. Support member 29
The upper part of the hollow hole is slightly smaller in diameter than the lower part, and the upper end of the arm shaft 31 penetrating through the hollow main shaft 25 is fitted and fixed using the key 32 and the bolt 33.
A gear 29a is formed on the outer periphery of the lower end of the support member 29, and the gear 29a meshes with the side segment gear 34. An oscillator 35 is fixed to the segment gear 34, and this is driven by the cam 24.

The hollow main shaft 25 sandwiched between the inner peripheral surface of the support member 29 and the outer peripheral surface of the arm center shaft 31 is not fixed to the two 29, 31 and can be independently rotated around the shaft.

The hollow main shaft 25 is reciprocated in the vertical direction by moving the cylindrical member 36 having a circumferential groove fixed near the center in the vertical direction up and down. Further, the hollow main shaft 25 is
Spline countershaft 37 surrounding the lower spline 25a
It rotates with the rotation around the axis. The spline sub shaft 37 has follower rollers 38 as followers of the cam 21 on upper and lower surfaces of a flange portion 37a formed on the outer periphery thereof. Hollow spindle
The turning arm A of the present embodiment is fixed to the lowermost flange 25b of the 25.

Now that the overall configuration of the tool changer has been clarified, the movement of the swivel arm A of the present embodiment is related to the configuration of the four cams 21 to 24 provided on the ATC shaft 18,
explain.

The turning arm A turns in the horizontal direction. This is for exchanging the tool T between the spindle 9 and the tool magazine 10.
The parallel cam 21 provided at the lowest position of the ATC drive shaft 18 is involved in this movement. The movement by this is the same as that of the corresponding part of the device disclosed in Japanese Patent Application Laid-Open No. 63-123646, and will be described briefly (the same applies to the movement by the cams 22 and 23 described later). The parallel cam 21 is a composite cam composed of two plate cams 21a and 21b,
Is in contact with a follower roller 38 provided as a follower provided in the control unit. Based on this configuration, during one rotation of the ATC drive shaft 18, the spline counter shaft 37, the hollow main shaft 25, and the swing arm A
Rotates 180 °.

Further, the swing arm A reciprocates in the axial direction of the hollow main shaft 25. This is for extracting or clamping the tool T from the headstock 9 or the tool magazine 10. What is involved in this movement is the first cylindrical groove cam 23 formed on the upper peripheral surface of the cylindrical member 39 around the ATC drive shaft 18. A contact 41 provided at the tip of a swing lever 40 engaged with the first cylindrical groove cam 23 is engaged with a circumferential groove of a cylindrical member 36 outside the hollow main shaft 25, and the ATC drive shaft During one rotation of 18, the hollow spindle 25
And the swing arm A fixed thereto is moved in the axial direction by 1
Reciprocate.

Further, the finger pair 17 of the swing arm A opens and closes.
The movement is related to the cylindrical member 39 around the ATC drive shaft 18.
Are the flat groove cams 24 on the upper surface. In FIG. 6, X-
The X sectional view is shown. As shown in the figure, the groove shape of the flat grooved cam 24 is a closed ring shape, and has a large-diameter portion 24a and a small-diameter portion 24b that are arc-shaped around the cam shaft and a connecting portion 24c that connects them. . The rocker 35 is rotated by the rotating flat groove cam 24.
The finger pair 17 is in a closed state, an open state, or an opening and closing movement state depending on where the large diameter part 24a, the small diameter part 24b, and the connecting part 24c are assembled (this detailed movement will be clarified later).

The second cylindrical groove cam 22 formed below the peripheral surface of the cylindrical member 39 outside the ATC drive shaft 18 functions as follows (see FIG. 4). The tool release pin 13 connected to the draw bar 12 of the tool attaching / detaching device of the main shaft 9 is pressed down by the swing member 42 which is swung by following the second cylindrical groove cam 22,
When the tool T is set on the main shaft 9, it can be set in a detached state.

The details of the configuration of the revolving arm A of the present embodiment whose movement has been clarified in the above description, and the interrelation of the above-described movements will be sequentially described below.

As shown in FIGS. 1 and 2, the arm body 16 of the revolving arm A penetrates the center hole thereof, and the hollow cam shaft 51 which rotates independently of the arm body 16 in the center hole. Symmetric to it. The arm body 16 is screwed to the flange 25b of the hollow main shaft 25 around the hollow cam shaft 51.

The hollow cam shaft 51 has a flange-like cam portion 51a that extends in the horizontal direction and is adjacent to the spacer S near the center in the vertical direction.
Are integrally provided. When viewed from below (see FIG. 1), the cam portion 51a has a shape in which two symmetrical positions of a perfect circle are notched. The two notches 51b are identical.
Note that the hollow hole of the hollow cam shaft 51 is
Can be fitted and removed by moving up and down relatively.

On the upper surface of the arm body 16, two pairs of through holes 52, 53
(See FIG. 2) is provided symmetrically with respect to the hollow camshaft 51. Utilizing the through holes 52 and 53 of each set, two sets of finger pairs 17 having the same configuration are supported by the arm body 16 with bolts 54 and nuts 55. The two pairs of fingers 17, 17
Are arranged in such a manner that the center lines Y1 and Y2 which the fingers FA and FB of each have as reference for opening and closing are parallel to each other and have a predetermined interval. Here, the center line Y1 is a finger FA forming one finger pair,
The center line Y2 corresponds to the vertical bisector of the line connecting the centers of rotation of the FBs, and the center line Y2 is the vertical line of the line connecting the centers of rotation of the fingers FA and FB forming one finger pair. Corresponds to a bisector.

The finger FA on the side of each pair of finger pairs 17 close to the center cam shaft 51 has a cylindrical portion 17a into which the bolt 54 is inserted, and a finger extending to the outside of the arm body 16 and having a gripping claw G at the tip. The main part 17b and the finger main part from the cylindrical part 17a
A passive portion 17c extending substantially in the opposite direction to 17b, and a projection 17d projecting substantially perpendicularly thereto are integrally formed. The other finger FB is substantially symmetric with the finger FA. However, the passive corresponding unit 1 corresponding to the passive unit 17c
7x is slightly smaller than the passive part 17c,
Projection corresponding to 7d (hereinafter, referred to as engagement portion) 17y
Is slightly different in position from the projection 17d.

Each of the fingers FA and FB is rotatable about an axis parallel to the axis of the hollow cam shaft 51 of the revolving arm A by the support of the bolt 54 and the nut 55, and the projection 17d and the engagement portion 17y Are in a state where they face each other, and furthermore, the passive portion 17c of the finger FA is arranged in the cutout portion 51b. The bush 5 is located between the inner surface of the cylindrical portion 17a and the outer surface of the bolt 54.
6, the above-mentioned support is performed in a state in which a bearing ring 57 is interposed between the arm body 16 and the upper end surface of the cylindrical portion 17a.

A spring 58 is attached to the arm body 16 by a spring holder 59 so as to be located between the passive portion 17c and the passive corresponding portion 17x of each finger pair 17.
Set with.

The spring 58 urges the passive portion 17c and the passive corresponding portion 17x in the opening direction (outward direction). For this reason, the finger pair
The two finger main parts 17b of the 17 are fixed cylindrical parts 17a.
The fulcrum is urged in the closing direction. However, the finger FA has its passive portion 17c in contact with the cam portion 51a, and is in a state of not closing for a certain amount or more. On the other hand, since the engagement portion 17y of the finger FB is engaged with the projection 17d of the finger FA, the finger FB is prevented from closing more than a certain extent.

When the passive portion 17c is pressed against the urging force of the spring 58, the finger FA rotates in the opening direction with the cylindrical portion 17a as a fulcrum, and the engagement portion 17y of the finger FB is pressed by the protrusion 17d. To the open side. Such Fingers vs. 17
Is released by the cam portion 51a applying a pressing force to the passive portion 17b by the rotation of the cam portion 51a around the central axis by a predetermined angle.

Further, as is apparent from FIG. 2, the revolving arm of this embodiment includes a center shaft presser 62, an arm main body presser 63 and the like.
The center shaft retainer 62 is inserted into the center hole of the arm main body 16 with the lower side of the hollow cam shaft 51 interposed with the bush 64 interposed therebetween.
The arm body retainer 63 that is joined to the
17a is inserted. The center shaft retainer 62 and the arm body retainer 63 are spaces surrounded by the arm body 16 and house a driving mechanism (such as a spring 58) for the finger pair 17. The gap between the cylindrical portion 17a of each of the fingers FA and FB and the hole of the arm body retainer 63 into which the finger is inserted is provided with a rubber sealing material 65 that closes the gap. Thus, the space including the drive portion of the swing arm A is sealed. In addition, the hollow cam shaft presser
62 is joined and supported by the arm body presser 63.
The center hole of the hollow cam shaft retainer 62 has a disk 66 around it.
Are joined.

The details of the movement of the swing arm A having the above configuration will be described with reference to FIG. 7, together with the movements of other members movable in connection with the swing arm A. FIG. 7 is a timing chart showing the movement of the swing arm A and the like.

When performing a tool change, the spindle 9 stops at a fixed position,
As soon as it is confirmed, the ATC drive shaft 18 starts rotating. When the ATC drive shaft 18 starts rotating, the vertically movable swing arm A is at the top dead center, and the arm center shaft 31
And the hollow cam shaft 51 of the turning arm A are in a fitted state. And the cam part 51a around the outside of the hollow cam shaft 51 is
The passive part 17c of the finger FA is pressed, and the finger FA is
In the open state against the urging force. Finger FB
Since the engaging portion 17y is pressed by the projection 17d of the finger FA, it is open against the urging force of the spring 58. That is, the two finger pairs 17 are open.

The tool T clamped to the spindle 9 is provided between the gripping claws G of the two pairs of fingers 17 in the opened state, and the tool magazine 10 is provided between the other gripping claws G of the two pairs of fingers 17. A clamped tool T is interposed.

When the ATC drive shaft 18 rotates and reaches the rotation angle of 12 °, the rocker 35 comes off the small diameter portion 24b of the flat groove cam 24, reaches the connecting portion 24c, and starts rocking. Accordingly, the segment gear 34, the support member 29, and the arm center shaft 31 that follow the oscillator 35 also start rotating. In addition, the rotation of the arm shaft 31 causes the hollow cam shaft 51 of the revolving arm A fitted thereto to also start rotating.
Then, the outer cam portion 51a of the hollow cam shaft 51 starts to rotate in the direction of arrow M in FIG. 1, that is, the direction in which the finger FA is not pressed. Therefore, the finger FA starts closing due to the urging force of the spring 58. The finger FB receives the movement by the engaging portion 17y, and starts closing by receiving the urging force of the spring 58.
When the ATC drive shaft 18 rotates by 50 ° and the oscillator 35 reaches the large diameter portion 24a of the flat groove cam 24, the oscillator 35 enters a stationary state.
At that time, the arm shaft 31 enters the stationary state after being rotated 18 ° from the initial state. Along with this arm center shaft 31, 18
カ ム Cam portion 51a of the hollow cam shaft 51 that enters the stationary state after rotation
Does not apply a pressing force to open the finger FA in the stationary state. Therefore, two pairs of fingers
17 is closed by a spring 58. As a result, they grip the tool T on the spindle 9 and the tool magazine 10, respectively.

When the ATC drive shaft 18 rotates exactly 25 ° while the finger pair 17 changes from the open state to the closed state, the tool release pin 13 starts to move down by the action of the second cylindrical groove cam 22. Then, when the ATC drive shaft 18 rotates by 75 °, the spindle 9 is completely released from the tool T (unclamped state).

While the tool T changes from the clamped state to the unclamped state, more precisely, when the ATC drive shaft 18 rotates 65 °, the turning arm A starts to descend by the first cylindrical groove cam 23.
Then, the turning arm A reaches the bottom dead center when the ATC drive shaft 18 rotates 125 °. Note that when the ATC drive shaft 18 is around 100 °, the arm center shaft 31 and the hollow cam shaft 51 of the turning arm A are separated.

While the turning arm A reaches the bottom dead center from the top dead center, the tool T is pulled out from the tool magazine 10 and detached. In the meantime, to be precise, when the ATC drive shaft 18 rotates 100 °,
By the action of the parallel cam 21 and the like, the turning arm A starts turning. Then, the turning ends when the ATC drive shaft 18 rotates 280 °. By this movement, the spindle 9 and the tool magazine
The arrangement of the two tools T set to 10 is switched.

During rotation of the swing arm A, the ATC drive shaft 18
゜ When rotated, the swing arm A starts to rise from the bottom dead center. When the ATC drive shaft 18 rotates 295 °, the top dead center is reached. At this time, the tool T is inserted into the tool magazine 10 and is clamped. On the other hand, a tool is inserted into the spindle 9, but is not yet clamped. In addition,
When the ATC drive shaft 18 is around 270 °, the arm middle shaft 31 and the hollow cam shaft 51 of the turning arm A are fitted and assembled.

When the ATC drive shaft 18 is rotated by 285 ° while the swing arm A advances from the top dead center to the top dead center, the release pin 13 starts to rise by the action of the second cylindrical groove cam 22.
Then, when the ATC drive shaft 18 rotates 335 °, the release pin 13 returns to the initial position, and the tool T is completely clamped to the main shaft 9.

When the ATC drive shaft 18 is accurately rotated by 310 ° while the tool T is being clamped to the main shaft 9 from the unclamped state, the rocker 35 comes off the large-diameter portion 24a of the flat groove cam 24 and the connecting portion 24c Assemble and start to swing again. Thus, the arm shaft 31 starts to rotate in a direction opposite to the above rotation. By the rotation of the arm center shaft 31, the hollow cam shaft 51 of the revolving arm A fitted thereto also starts to reversely rotate. Then, the outer cam portion 51a of the hollow cam shaft 51 starts rotating in the direction of arrow N in FIG. 1, that is, the direction of pressing the passive portion 17c of the finger FA. For that, the finger FA starts to open. Finger FB
Also, the movement is received by the engaging portion 17y via the projection 17d, and the opening starts. Accordingly, the two finger pairs 17 open.

The ATC drive shaft 18 rotates 348 °, and the oscillator 35
When the oscillator 35 reaches the small diameter portion 24b, the oscillator 35 enters a stationary state. At that time, the arm center shaft 31 returns to the same stationary state as the initial state. Along with the arm center shaft 31, the cam portion 51a around the hollow cam shaft 51 also returns to the initial stationary state and presses the passive portion 17c of the finger FA, and the finger FA opens.
The finger FB is also opened by the movement of the finger FA by the engaging portion 17y. As a result, finger vs.
17 releases the tool T between the spindle 9 and the tool magazine 10.

The swing arm A of the present embodiment described above has the following advantages.

In the swing arm A of the present embodiment, the finger pair 17 is
58, one of the fingers FA receives a direct force from the finger disengaging cam portion 51b by the passive portion 17c, and the other receives the force from the finger FB by the engaging portion 17y. And open and close. That is, the finger pair 17 receives the opening / closing force without any intervening force transmitting member such as a lever or a lever or the like, so that the movement of the finger pair 17 is accurately regulated, and the finger pair 17 opens and closes without delay. Therefore, the tool T can be reliably and quickly gripped in an accurate posture, and as a result, there is no possibility of failure of gripping the tool T, and the attachment and detachment of the tool T to and from the main shaft 9 can be performed reliably and quickly.

Further, there is no need to use a complicated mechanism such as a hydraulic mechanism or an interlock mechanism, and the configuration is simple.

Further, since the spring 58 is used for gripping the tool T, it is possible to easily grip the tool T of various sizes, and even if an external force is applied to the tool T, the spring 58 serves as a buffer. There is very little risk of finger pairs 17 functioning and being damaged.

Further, the space surrounding the drive portion of the finger pair 17 is covered from above by the arm body 16, and is shielded from below from below by using the arm body presser 63, rubber seal material 65, and the like. Therefore, there is no danger that the cutting chips are entangled with the driving part during the processing by the tool T attached to the main shaft 9, and the movement of the driving part is not hindered.

Although the embodiments of the present invention have been described above, the present invention is not limited to such embodiments at all. For example, a spring is provided between each pair of fingers in a direction in which the claw portions at their tips open, and the finger driving cam is provided. Can be implemented in various modes without departing from the gist of the present invention, such as a configuration in which each finger pair is moved in the closing direction by acting on the passive portion.

[Effects of the Invention] As described above in detail, according to the tool exchange arm of the present invention, the finger pair can be opened and closed by the cam, the passive portion receiving the movement, the spring, and the engaging portion that abuts each other. Since the force for opening / closing the finger is directly transmitted without passing through a portion where rattling occurs, the movement for opening / closing the finger is accurately defined. And the movement is quick. Therefore, the tool can always and reliably be held in an accurate posture. As a result, there is no failure in gripping the tool, and the attachment and detachment of the tool to and from the spindle or the tool magazine can be performed reliably and quickly. Further, there is no need to use complicated mechanisms such as a hydraulic mechanism, a link mechanism, and an interlock mechanism, so that the configuration is simple and the number of parts is small. This facilitates manufacturing and reduces costs.

[Brief description of the drawings]

FIG. 1 is a view of a main part of the revolving arm viewed from below,
FIG. 2 is a vertical sectional view of a turning arm as one embodiment of a tool changing arm of the present invention, FIG. 3 is a perspective view showing a machining center to which the turning arm is mounted, and FIG. FIG. 5 is a partial sectional view showing the configuration of the tool changer, FIG. 6 is a sectional view taken along line XX of FIG. 5, and FIG. 7 is a timing chart showing the movement of the swing arm and the like. 16 Arm body 17 Finger pair 17c Passive part 17d Projection part 17y Engagement part FA, FB Finger 51 Hollow cam shaft 58 Spring

Continuation of the front page (56) References JP-A-49-52084 (JP, A) JP-A-62-251040 (JP, A) JP-A-62-188641 (JP, A) , U) Japanese Utility Model Showa 62-98605 (JP, U) JP-B 57-17667 (JP, B2)

Claims (1)

(57) [Claims] 1. A tool exchange arm main body capable of turning around one axis is provided with a plurality of pairs of openable and closable fingers, and a tool set on a main spindle of a machine tool and a tool magazine is provided. A tool change arm that exchanges by using gripping by the finger pair and turning of the tool change arm body, wherein each of the finger pairs is attached to the tool change arm body around an axis parallel to the axis. A biasing means is attached to the pair of fingers so as to be rotatable, and biases the finger pair at the tip of the pair of fingers to close or open. A moving finger driving cam, which directly contacts one finger of the finger pair with the finger driving cam, receives a pressing force accompanying the rotation of the cam, and resists the urging force of the urging means. Open the finger A passive portion for turning in the direction or the closing direction is provided, and the other finger is formed with an engaging portion which abuts on the finger having the passive portion and turns the other finger by the rotation. Tool change arm of machine tool.