JPH05104379A - Automatic tool exchange device - Google Patents

Abstract

PURPOSE:To ensure operation of re-inserting a tool in a chuck provided on the front end opening part of a main axis of an automatic tool exchange device in which a plurality of tools are stored in a hollow hole of the main axis comprising hollow axis in such a way that the tools can be moved in the axial direction. CONSTITUTION:A guiding cylinder 31 to be fitted into a hollow hole 3 of a main axis 2 has a dividing cam groove on the inner circumferential surface of the rear end part. A plurality of operational shafts 32 for individually connecting tools T are stored in the guiding cylinder 31 in such a way that the shafts can be freely moved in the axial direction. A clutch shaft 33 is rotated in a divided manner by the clutch body 33 by having a push rod proceeded or withdrawn, and is engaged with an engagement groove 43 of the operational shaft 32 selected by a dividing plate 51, while the tool T connected to the operational shaft 32 is inserted into a chuck 4 at the time of proceeding of the clutch shaft 33, and the tool is clamped thereby, and is returned to a waiting position from the chuck at the time of withdrawl.

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to an automatic tool changing device for a machine tool such as a machining center, and more particularly to an automatic tool changing device for accommodating a plurality of tools in a hollow hole of a main shaft made of a hollow shaft.

[0002]

2. Description of the Related Art The applicant of the present application accommodates a plurality of tools in a hollow hole of a main shaft made of a hollow shaft so as to be movable in the axial direction, and replaces these tools with a chuck provided at a front end opening of the main shaft. Japanese Patent Application No. 63-93867 and Japanese Patent Application No. 3228092
(See Japanese Patent Laid-Open No. 1-264734).

In the automatic tool changer according to the above-mentioned patent application, a plurality of tools housed in a guide cylinder (tool holder) fitted in the hollow hole of the main shaft are reciprocally moved in the axial direction to cause the chuck to move. For replacement, a tool changing cylinder device was provided for each tool.

[0004]

However, in such a structure, it is necessary to individually provide a plurality of cylinder devices corresponding to the number of tools and a switch or other auxiliary device for confirming the operation of the cylinder devices. However, there is a problem that not only the number of parts is large and the cost is high, but also the entire device is large and heavy. In addition, the wiring and assembly are troublesome and costly.

The present invention has been made to solve the above problems, and a plurality of tools can be alternately replaced with the chucks by reciprocally moving one push rod in the axial direction. It is an object of the present invention to provide an automatic tool changing device that can be used.

[0006]

In order to achieve the above object, in the automatic tool changer of the present invention, the tool replacement unit has an indexing cam groove on the inner peripheral surface of the rear end portion, A guide cylinder body fitted into the hollow hole of the main shaft,
Arranged annularly along the inner peripheral surface of the guide cylinder,
And a plurality of actuating rods that are individually movably accommodated in the axial direction and that individually connect the tools, and first and second engaging grooves that are provided on the inner surface of each of the actuating rods and are axially separated from each other, One clutch shaft fitted and inserted in the central portion of the guide cylinder so as to be surrounded by the plurality of operating rods, and arranged so as to be movable and rotatable in the axial direction, and a rear end of the clutch shaft. And a clutch body that is fixedly mounted on a shaft portion and axially reciprocates, and that is engaged with the indexing cam groove for indexing rotation, and is fixed to the clutch shaft away from the clutch body on the front end side in the axial direction. And an indexing plate that engages with the first engaging groove of the operating rod indexed by rotation of the clutch body, and an axis that is separated from the indexing plate toward the front end side in the axial direction and that is relatively axial to the clutch shaft. It is fitted so that it can slide in any direction, and A locking plate that engages with the second engaging groove of the operating rods other than the operating rods indexed by the rotation of the chisel to prevent axial movement of these operating rods; and the indexing plate. Is interposed between the locking plate and the locking plate, and biases the locking plate to fix the locking plate at a predetermined position in the guide cylinder,
A return spring for urging the clutch shaft to return to the standby position via the indexing plate, and a guide cylinder body fitted so as to be movable only in the axial direction from the rear end, and engaged with the clutch body at the front end. A push rod provided with a cam and a drive means for reciprocating the push rod in the axial direction. When the push rod is moved forward, the cam first engages with the clutch body to move the clutch body. When the index plate is rotated along the cam groove while pushing, the index plate engages with the first engaging groove of the indexed operating rod, and at the same time, the locking plate causes the indexed operation. While engaging with the second engaging groove of the operating rod other than the rod, and subsequently compressing the return spring with the indexing plate, the clutch shaft moves forward integrally with the indexed operating rod,
While the tool connected to the operating rod is inserted into the chuck and moved to the clamp position, when the push rod is retracted, the return spring acts to cause the clutch shaft to move through the indexing plate. Along with this, the tool is returned between the standby positions, the tool is housed in the standby position, and the clutch body is rotated along the cam groove by a predetermined angle during the movement thereof.

A cylinder device is usually used as means for reciprocating the push rod in the axial direction.

[0008]

With the above construction, each time the push rod is repeatedly moved forward and backward in the guide cylinder in the axial direction, the plurality of operating rods housed in the guide cylinder are sequentially reciprocated in the axial direction, and when the push rod moves forward. A tool is exchanged by inserting a tool connected to one selected operating rod into the chuck and clamping the tool, and by retracting the tool from the chuck to the standby position when retracting.

Further, if the stroke for advancing and retracting the push rod is shortened, the index plate is sequentially engaged with the first engaging groove of the adjacent operating rod without changing the tool. It is also possible to select and replace an arbitrary tool regardless of the arrangement.

[0010]

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

1 and 2 show a vertical sectional front view of the first half of the automatic tool changer according to the present invention, and FIG. 2 shows a vertical sectional front view of the latter half thereof.

Reference numeral 1 is a spindle head, and 2 is a spindle, which comprises a hollow shaft (quill) having a hollow hole 3 extending over the entire length, and a chuck 4 is attached to a front end opening. The main shaft 2 has a ball spline nut 5 and a ball screw nut 6
Are fitted. An outer cylinder 7 fitted to the front end portion of the main shaft 2 is connected to the ball spline nut 5, a transmission pulley 8 is fitted to the outer cylinder 7, and a boss 9 fixed to the ball screw nut 6 is provided. The transmission pulley 10 is fitted in the.

The ball spline nut 5 and the ball screw nut 6 fitted to the spindle 2 as described above are rotatably supported by the spindle head 1 via bearings 11 and 12, respectively. The ball spline nut 5 has a support frame 13
Is driven to rotate by a first servomotor 14 attached to the spindle head 1 via a timing belt 15 and a transmission pulley 8, and the ball screw nut 6 is attached to the spindle head 1 via a support frame 16. 2 Servo motor 17 is rotationally driven via timing belt 18 and transmission pulley 10. When the ball spline nut 5 is rotationally driven, the main shaft 2 makes a rotational motion, and when the ball screw nut 6 is rotationally driven, the main shaft 2 makes a reciprocating motion in the axial direction. Therefore, when both nuts 5 and 6 are driven to rotate at the same time, the spindle 2 reciprocates in the axial direction while rotating. Therefore, drilling, tapping, etc. can be performed by a drill or other rotary tool T clamped to the chuck 4. You can At this time, the main shaft 2 and the outer cylinder 7 rotate synchronously.

The chuck 4 includes a main body 21 having a collet 20, and a sleeve 2 with a taper fitted in the main body 21.
2, a front cover 23 fitted to the sleeve 22, and a disc spring 2 interposed between the sleeve 22 and the front cover 23.
4 and six unclamp pins 25 (only two are shown in FIG. 1) arranged on the outer peripheral portion of the main body 21 at equal intervals in the circumferential direction. Main body 21 is main shaft 2
The front cover 23 is fitted and fixed to the front end opening 2 a of the front cover 23, and the front cover 23 is fixed to the main body 21. The tapered sleeve 22 is fitted onto the collet 20 so as to be slidable in the axial direction, and is biased by a disc spring 24 so as to clamp the collet 20. The unclamp pin 25 extends through the main body 21 in parallel with the axis of the main shaft 2, the inner end flange portion 25a contacts the flange portion 22a of the sleeve 22, and the outer end portion 25b extends rearward from the main body 21. It is protruding.

When the main shaft 2 moves backward to the rearmost position, the outer end portion 25b of the unclamp pin 25 abuts the end face of the outer cylinder 7 and is pushed toward the sleeve 22 side, and the inner end collar is formed. The collet 20 is unclamped by pushing the sleeve 22 against the disc spring 24 at the portion 25a.

Reference numeral 30 is a tool replacement unit for replacing a plurality of tools T with the chuck 4. The unit 3
0 is a guide cylinder 31 fitted into the hollow hole 3 of the main shaft 2,
A plurality of (four in the illustrated example) actuating rods 32 are annularly arranged along the inner peripheral surface of the guide cylinder 31 and are movably in the axial direction, and the actuating rods 32. One clutch shaft 33 fitted and inserted in the central portion of the guide cylinder 31 so as to be surrounded by, and arranged so as to be movable and rotatable in the axial direction, and the guide cylinder 31 from the rear end in the axial direction. And a push rod 34 (see FIG. 2) that is movably fitted in and is engaged with the clutch shaft 33. Each of these members 31 to 34 is formed of plastic or resin in order to reduce the weight.

As shown in FIG. 3 showing the whole, the guide cylinder 31 has a taper portion 35 which converges toward the chuck 4 at the front end portion thereof, and a thin taper portion which is continuous with the taper portion 35. In order to house the operating rods 32 in a ring shape along the inner peripheral surface of the guide body 31 at the rear of the taper portion 35, the tool T has a cylindrical portion 36, and each tool T is individually placed in a standby position. Tool holding part 37 having through holes 38 for holding the
Are formed. Then, the tool T is individually mounted on the inner wall surface extending from the front end opening of the through hole 38 to the taper portion 35.
A guide groove (not shown) that guides to 6 is provided corresponding to each through hole 38. The tip of the cylindrical portion 3b is supported by the main body 21 of the chuck 4 via a bearing. On the other hand, inside the rear end of the guide cylinder 31, a guide groove 39 having a cross-shaped cross section that guides the clutch shaft 33 and the push rod 34 so as to be movable only in the axial direction, and a rear end of the guide groove 39, which will be described later. Indexing cam groove 40 for indexing and rotating the clutch body 50
And a guide groove 41, which is continuous with the cam groove 40 and has a cross-shaped cross section, which guides the push rod 34 movably only in the axial direction. The cross groove of the guide groove 41 has the same phase as the cross groove of the guide groove 39, but is slightly shallower. A mounting flange 42 is provided on the outer side of the rear portion of the guide cylinder 31 so as to project therefrom.

The operating rod 32 is formed on an elongated cylindrical shaft which is inserted into the through hole 38, and a first engaging groove 43 for engaging with an indexing plate described later is provided on the inner surface of the rear end, while the inner surface of the front end is provided. Is provided with a second engagement groove 44 that engages with a locking plate described later. Both engagement grooves 43, 44 open toward the center of the guide cylinder 31, and the groove bottoms are formed in an arc shape. A tool T is connected to the front end of the operating rod 32 via a wire 45 and a connecting fitting 46. A bearing (not shown) is interposed between the tool T and the connecting fitting 46, and the tool T is rotatable with respect to the connecting fitting 46.

The clutch body 5 is attached to the clutch shaft 33.
0, the index plate 51, and the locking plate 52 are attached to each other at intervals in the axial direction.

The clutch body 50 is fixed to the rear end of the clutch shaft 33, and as shown in FIGS. 5 and 11, four clutch pawls 53 projecting in the radial direction are provided on the outer peripheral portion at 90 ° different phases. The clutch claws 53 are engaged with the guide groove 39 to move the clutch shaft 33 into the guide cylinder 3
The guide is movably only in the axial direction with respect to 1. At both ends of each clutch claw 53, inclined cam surfaces 53a and 53b for causing an indexing rotation operation described later are provided (FIG. 1).
4 and FIG. 16).

The indexing plate 51 is fixed to the clutch shaft 33 at a certain distance from the front end of the clutch body 50 in the axial direction, and is fixed to the clutch shaft 33. Each notch 54
Two short peripheral edges 55, 55 and one long peripheral edge 56 are left between them (see FIGS. 6 and 12).

The clutch shaft 33 is shown in FIG.
When in the rear standby position shown in (A), as shown in FIG. 6, the peripheral portions 55 and 56 of the indexing plate 51 are moved to the respective operating rods 3.
The second engaging groove 43 is engaged. On the other hand, the clutch body 5
When 0 is indexed and rotated, the long peripheral edge portion 56 engages only with the engaging groove 43 of the operating rod 32 connecting the selected tool T, and the engaging groove 43 of the other operating rod 32 is split. The delivery plate 51 does not engage (see FIG. 12). Therefore, only the operating rod 32 of the selected tool T can be moved in the axial direction in association with the clutch shaft 33.

The locking plate 52 is axially slidably fitted on the clutch shaft 33 at a position further distant from the indexing plate 51 toward the front end side in the axial direction, and as shown in FIGS. Has a protrusion 58 that engages with an axially extending key groove 57, and rotation is blocked by the protrusion 58. The locking plate 52 has a shape in which one circular arc-shaped cutout 59 is provided on the outer peripheral portion of the disk. And
When the clutch shaft 33 is in the standby position shown in FIG. 3A, the peripheral edge portion 60 of the locking plate 52 is engaged with the second engagement groove 44 of each operating rod 32 as shown in FIG. Prevents axial movement. On the other hand, when the clutch body 50 is indexed and rotated, as shown in FIG. 13, only the operating rod 32 connecting the selected tool T is positioned opposite the arcuate cutout 59 from the locking plate 52. Although it is disengaged and is free to move in the axial direction, the peripheral edge portion 60 of the locking plate 52 is engaged with the engaging groove 44 of the other actuating rod 32 to prevent the movement in the axial direction.

A return spring 61 is interposed between the indexing plate 51 and the locking plate 52. By the return spring 61,
The locking plate 52 is the rear end 37a of the tool holder 37 (see FIG. 1).
The clutch shaft 33 is urged through the indexing plate 51 so as to return to the standby position shown in FIG. 3 (A). Also, the clutch shaft 33
The first half portion provided with the key groove 57 passes through the locking plate 52 rotatably supported by the rear end 37a of the tool holding portion 37 and is inserted into the through hole 62 provided at the center of the tool holding portion 37, It is possible to move forward.

As shown in FIG. 14, the push rod 34 is axially movably fitted from the rear end of the guide cylinder 31, and the clutch body 50 is attached to the large-diameter shaft portion 63 continuously provided at the front end. A cam 64 that engages with the inclined cam surface 53a of the clutch piece 53 is provided, and four guide ridges 65 that project in the radial direction are provided on the outer periphery of the clutch piece 53 at 90 ° different phases.
Is provided and the protrusions 65 engage with the guide grooves 41 and 39, whereby the push rod 34 is guided so as to be movable only in the axial direction with respect to the guide cylinder 31. On the other hand, the rear part of the push rod 34 extends so as to project from the guide cylinder 31, and the rear end thereof is interlockingly connected to the cylinder device 67 via the connecting plate 66, as shown in FIG. Although not shown in the drawing, the air cylinder device 67 is supported and fixed to a support frame 70 described later.

As shown in the development view of FIG. 15B, the indexing cam groove 40 has a partition wall 39 at the rear end portion of the guide groove 39.
It is formed in an annular groove that extends in the circumferential direction across a, and the diameter of the groove bottom is the same as the diameter of the groove bottom of the guide groove 39 so that the clutch claw 53 can engage and rotate. Further, on the groove wall surface adjacent to the guide groove 41, four inclined cam surfaces 68 extending from the partition wall 41a across the guide groove 41 are provided, and the inclined cam surface 53a of the clutch pawl 53 closely contacts the inclined cam surface 68. Engage and rotate indexing.

A step 68a is formed between the inclined cam surfaces 68 adjacent to each other. On the other hand, the groove wall surface adjacent to the guide groove 39 is provided with four inclined cam surfaces 69 extending across the partition wall 39a, and the inclined cam surfaces 53b of the clutch pawls 53 are closely engaged with the inclined cam surfaces 69. It can be indexed and rotated. The inclined cam surface 69 does not have a step portion corresponding to the step portion 68a of the inclined cam surface 68.
FIG. 15A shows the upper end surface of the developed view, and FIG.
(C) has shown the lower end surface of the same development view.

1 and 2, reference numeral 70 denotes a support frame for the tool replacement unit 30. The support frame 70 is movably mounted in parallel with the axis of the spindle 2 along a guide rail 71 provided at the bottom of the spindle head 1, and is connected to the rear end of the spindle 2 via a bearing 72. .. Then, the guide cylinder 31 is inserted into the hollow hole 3 of the main shaft 2 from the rear end opening.
Is fixed to the support frame 70 by a set screw 73, while the cylindrical portion 36 at the front end of the guide cylinder 31 fitted in the hollow hole 3 is supported by the chuck body 21 via a bearing 74 so as to be relatively rotatable. The replacement unit 30 is detachably fitted in the hollow hole 3 of the main shaft 2.

The operation of the automatic tool changer having the above structure will be described in accordance with the operation sequence shown in (a) to (h) of FIG.

When exchanging tools, first, the spindle 2 is retracted to the rearmost position, and the sleeve 22 is pushed against the disc spring 24 by the unclamp pin 25 that abuts against the end surface of the outer cylinder 7, and the collet 20 is pressed. Unclamp.

FIG. 16A shows a state in which the push rod 34 is stopped at the rear end position shown in FIG. 3A. At this stop position, the clutch body 50 of the clutch shaft 33 and the cam 64 at the tip of the push rod 34 are separated. On the other hand, each clutch claw 53 of the clutch body 50 engages with the inclined cam surface 68 of the indexing cam groove 40 and the step portion 68a,
The rotation is blocked. Then, the peripheral edges 55 and 56 of the indexing plate 51 engage with the first engaging groove 43 of each operating rod 32, and the peripheral edge 60 of the locking plate 52 engages with the second engaging of each operating rod 32. Each operating rod 3 is engaged with the groove 44.
2 is prevented from moving in the axial direction, and the operating rod 32 is prevented from moving unexpectedly to cause an error in indexing the tool T (see FIGS. 6 and 7).

When the cylinder device 67 operates in this state and the push rod 34 is moved forward, the cam 64 engages with the inclined cam surface 53a of the clutch pawl 53 and the clutch shaft 33 is returned, as shown in FIG. 16 (b). After moving the clutch pawl 53 from the inclined cam surface 68 against the spring 61 in the axial direction, the other inclined cam surface 53b is indexed to the cam groove 4.
The inclined cam surface 69 of 0 is contacted. Then, in FIG.
As shown in FIG. 16C, the clutch claw 53 is guided by the inclined cam surface 69 and moves obliquely, and the cam 6 is moved as shown in FIG.
4 is engaged with the guide groove 39 by being locked by the step portion 64a. The movement of the clutch pawl 53 causes the clutch shaft 33 to rotate by 45 degrees.

When the clutch shaft 33 is indexed and rotated as described above, the indexing plate 51 interlocked with the clutch shaft 33 has a peripheral edge portion 56 of the operating rod 32 which connects the indexed specific tool T. Only the engaging groove 43 is engaged, and the remaining operating rod 3
The second engagement groove 43 is not engaged (see FIG. 12). On the other hand, in the locking plate 52 that also rotates in conjunction with the clutch shaft 33, only the operating rod 32 that connects the indexed tool T is positioned to face the arcuate notch 59 and unlocked. Free movement in the axial direction (see FIG. 13). When the push rod 34 moves forward in this state, the clutch claw 53 of the clutch body 50 moves along the guide groove 39 as shown in FIG. 16 (e), and the clutch shaft 33 advances axially in a posture in which the rotation is blocked. Moving. In conjunction with this, the operating rod 32 locked to the indexing plate 51 is pushed out to the chuck 4 side, the tool T connected to the operating rod 32 is inserted into the collet 20 of the chuck 4, and the collet 20 It stops at the clamp position that protrudes a certain length from the front end. At this time, the return spring 61 is compressed by the indexing plate 51 (see FIGS. 1 and 3B). Then, spindle 2
When is advanced slightly by the ball screw nut 6, the unclamp pin 25 is separated from the outer cylinder 7, and the collet 20 is automatically clamped by the disc spring 24 to grip the tool T.

In this state, the spindle 2 rotates and the cutting work with the tool T is performed. During the processing, the operating rod 32 connecting the push rod 34 and the tool T is stopped at the forward position, that is, the tool pushing position shown in FIG. 3B.

When the machining is completed and the next tool exchange is to be performed, the spindle 2 is retracted to the final rear end position to unclamp the collet 20 in the same manner as described above, and then the cylinder device 6 is used.
7 is operated to retract the push rod 34. When the push rod 34 starts to retract, the clutch shaft 3
3 is also retracted by the return spring 61, and the tool T connected to the operating rod 32 interlocking therewith is pulled out from the collet 20 and returned to the standby position. Then, when the clutch body 50 moves backward to the indexing cam groove 40 again, as shown in FIG.
4 and the clutch claw 53, which is locked to the step portion 64a, again abuts and engages with the inclined cam surface 68 of the indexing cam groove 40, and when the push rod 33 further retracts, as shown in FIG.
As shown in (g), the clutch claw 53 disengages from the cam 64 and the stepped portion 64a, and is guided by the inclined cam surface 68 to move diagonally. As shown in FIG. Rotation is blocked by the inclined cam surface 68 and the stepped portion 68a at the position where it is locked to 68a, and FIG.
Return to the state of. The movement of the clutch pawl 53 causes the clutch shaft 33 to be further indexed and rotated by 45 degrees.
Return to the standby position of FIG. Thereafter, the same operation as described above is repeated to perform the tool exchange.

When it is desired to select and replace a tool T different from the tool T arranged next to it, the push rod 34 is indexed and rotated by 45 degrees, that is, the clutch body 50 is rotated. The long peripheral edge portion 56 of the indexing plate 51 is sequentially arranged next to it by advancing to the position where it is index-rotated along the cam groove 40, and then advancing and retracting for a short stroke to retreat again to the rear end position. The desired tool T can be selected and replaced by engaging with the first engaging groove 43 of the operating rod 32 that is present.

[0037]

As described above, according to the present invention,
By simply reciprocating one push rod 34 in the axial direction, the indexing plate 51 provided on the clutch shaft 33 that moves in the axial direction in conjunction with the push rod 34 is connected to the selected tool T. First engaging groove 43 of operating rod 32
The plurality of tools T housed in the hollow holes of the main shaft 2 can be arbitrarily exchanged by sequentially engaging with each other. Therefore, only one tool changing cylinder device 67 for operating the push rod 34 is required, and not only the manufacturing cost is low, but also the size and weight of the device can be reduced.

Further, in the present invention, the operating rods 32 other than the indexed operating rod 32 are locked and held by the locking plate 52 engaged with the second engaging groove 44, and are prevented from moving in the axial direction. Therefore, the indexing of the tool is reliable.

[Brief description of drawings]

FIG. 1 is a vertical sectional front view of a first half portion of an automatic tool changer according to the present invention.

FIG. 2 is a vertical sectional front view of the latter half portion.

FIG. 3 is a vertical sectional front view showing a standby state (A) and an operating state (B) of the tool replacement unit.

FIG. 4 is an enlarged cross-sectional view taken along the line 4-4 of FIG.

5 is an enlarged cross-sectional view taken along line 5-5 of FIG.

FIG. 6 is an enlarged cross-sectional view taken along line 6-6 of FIG.

FIG. 7 is an enlarged cross-sectional view taken along line 7-7 of FIG.

FIG. 8 is an enlarged cross-sectional view taken along the line 8-8 of FIG.

9 is an enlarged cross-sectional view taken along the line 9-9 of FIG.

10 is an enlarged cross-sectional view taken along the line 10-10 of FIG. 3 (B).

FIG. 11 is an enlarged cross-sectional view taken along line 11-11 of FIG.

12 is an enlarged cross-sectional view taken along line 12-12 of FIG. 3 (B).

13 is an enlarged cross-sectional view taken along line 13-13 of FIG. 3 (B).

FIG. 14 is a perspective view showing an outline of a main part of an indexing mechanism.

FIG. 15 is an explanatory diagram showing the development of the indexing cam groove.

FIG. 16 is an explanatory diagram showing an operation sequence of a clutch body.

[Explanation of symbols]

 1 Spindle Head 2 Spindle 3 Hollow Hole 4 Chuck 30 Tool Replacement Unit 31 Guide Cylindrical Body 32 Actuating Rod 33 Clutch Shaft 34 Push Rod 39, 41 Guide Groove 40 Indexing Cam Groove 43 First Engagement Groove 44 Second Engagement Groove 50 Clutch body 51 Indexing plate 52 Locking plate 53 Clutch claw 64 Cam

Claims (4)

[Claims] 1. A machine tool in which a plurality of tools are accommodated in a hollow hole of a main shaft made of a hollow shaft so as to be movable in the axial direction, and these tools are replaced with a chuck provided at a front end opening of the main shaft. In the automatic tool changer, the tool replacement unit has an indexing cam groove on an inner peripheral surface of a rear end portion, and a guide cylinder body fitted in a hollow hole of the main shaft, and a guide cylinder body in the guide cylinder body. Arranged annularly along the inner peripheral surface,
And a plurality of actuating rods that are individually movably accommodated in the axial direction and that individually connect the tools, and first and second axially spaced apart inner side surfaces of the actuating rods.
An engagement groove, and one clutch shaft fitted and inserted in the central portion of the guide cylinder so as to be surrounded by the plurality of operating rods, and arranged so as to be movable and rotatable in the axial direction, A clutch body that is fixedly mounted on the rear end of the clutch shaft and is engaged with the indexing cam groove to be indexed and rotated when reciprocating in the axial direction, and is separated from the clutch body toward the front end side in the axial direction. An indexing plate that is fixed to the clutch shaft and that engages with the first engaging groove of the operating rod that is indexed by the rotation of the clutch body; and the clutch that is separated from the indexing plate toward the front end side in the axial direction. The shafts of the operating rods are fitted to the shaft so as to be slidable in the axial direction, and engage with the second engaging grooves of the operating rods other than the operating rods indexed by the rotation of the clutch body. Locking plate to prevent movement in the direction, The clutch plate is interposed between the indexing plate and the locking plate and urges the locking plate so as to fix the locking plate at a predetermined position in the guide cylinder, while the clutch shaft is inserted through the indexing plate. A return spring for urging the guide cylinder body to return to a standby position; a push rod fitted in the guide cylinder body so as to be movable only in the axial direction from the rear end thereof; and a push rod provided with a cam for engaging the clutch body at the front end; Drive means for moving the rod back and forth in the axial direction, when the push rod moves forward, the cam first engages with the clutch body, and the index body rotates along the cam groove while pushing the clutch body. Then, the indexing plate engages with the first engaging groove of the indexed operating rod, and at the same time, the second of the operating rods other than the indexing rod with the locking plate indexed.
Is engaged with the engaging groove of the indexing plate, and subsequently, while the return spring is compressed by the indexing plate, the clutch shaft moves forward integrally with the indexing lever and is connected to the indexing rod. While moving the tool through the chuck to the clamp position, when the push rod retracts, the return spring acts to return the clutch shaft together with the operating rod to the standby position through the indexing plate. An automatic tool changer configured to accommodate the tool at a standby position and to rotate the clutch body along the cam groove at a constant angle during the movement thereof. 2. The automatic tool changer according to claim 1, wherein the guide cylinder has a taper portion that converges toward the chuck at a front end portion and a cylinder portion that is continuous with the taper portion. 3. A cylindrical portion of the guide cylinder, which is inserted into a hollow hole of the main shaft, is rotatably supported by the chuck, and a rear end portion thereof is movable in the axial direction in conjunction with the main shaft. The automatic tool changer according to claim 2, which is fixed to a support frame. 4. The push rod repeats a small stroke of forward movement and backward movement so that the indexing plate sequentially engages with the first engaging groove of the adjacent operating rod without performing a tool changing operation. The automatic tool changer according to claim 1, 2, or 3.