JPH08174315A - Tool holder temporary holding device in main spindle of machine tool - Google Patents

Abstract

PURPOSE: To provide a tool holder temporary holding device, wherein it is not necessary to link the driving of a tool unclamping device with the operation of an automatic tool changing device and the internal structure of a main spindle is simple. CONSTITUTION: A tool holder temporary holding device is constructed of a tapered engaged section 2c formed in an inner peripheral surface on the other end side of a collet 2, an engaging member 8 provided on the other side of the collet 2 and freely moved back and forth in a main spindle axial direction having a tapered engaging section 8a engaged with the engaged section 2c in an outer peripheral surface on one end side and an energizing means 9 for always energizing the collet 2 to one side via the engaged section 2c so as to bring this engaging member 8 into contact with the collet 2. When a draw bar 5 is moved to one side by a tool unclamping device, a tool holder T is temporarily held by means of energizing force from the energizing means 9 of the engaging member 8 applied to one side.

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a tool clamp / unclamp means for clamping a tool holder inserted in a tool insertion hole formed at one end of a main shaft by pulling the tool holder to the other end side when exchanging tools. In the spindle of the machine tool, the tool holder can be temporarily held by releasing the pull of the tool holder, and the tool holder can be removed by removing the temporary holder by the operation of pulling out the tool holder from the spindle. The present invention relates to a temporary holding device for a tool holder.

[0002]

2. Description of the Related Art To insert a tool holder having a tool attached to a spindle in a machine tool, insert the tool holder into the tool insertion portion of the spindle and engage a pull stud fixed to the tool holder with a collet or the like. Then, the tool holder is pulled and clamped by the draw bar biased by the spring. Further, when the tool is replaced, the drawbar pressing member of the tool unclamping device pushes the drawbar to release the tension of the tool holder and unclamp the tool holder. Such a mechanism is known as a collet type tensioning mechanism or a ball type tensioning mechanism.

By the way, an automatic tool changer (AT) for exchanging tools of a tool holder between a spindle and a tool storage magazine.
In the machine tool having C), the tool unclamping device is driven to unclamp the tool holder when the ATC arm engages with the tool holder inserted at one end of the spindle. Therefore, conventionally, the drive of the tool unclamping device and the operation of the ATC are made independent, and
The arm of C moves to the main spindle side to grip the tool holder, and while the tool unclamping device is driven until the tool holder is pulled out in the direction away from the main spindle, the pull of the tool holder by the draw bar is released. There is. In addition, recent machine tools tend to be heavy cutting and high speed rotation. However, in such a machine tool, the taper portion of the tool holder and the tapered tool insertion hole firmly bite, and the tool holder is moved backward with a large force in order to separate the tool holder from the tool insertion hole. I had to push it.
Therefore, tool clamp / unclamp operation and ATC
A technique relating to a tool attaching / detaching device that interlocks with the forward / backward movement of the arm is disclosed in Japanese Patent Application Laid-Open No. 63-2639 and Japanese Patent Application Laid-Open No.
No. 149150, for example.

However, the above-mentioned Japanese Patent Laid-Open No. 63-26
In Japanese Patent No. 39, the force of the cam is converted into hydraulic pressure for interlocking, and in Japanese Patent Application Laid-Open No. 3-149150, the force of the cam is interlocked by a mechanical mechanism using a swinging punch. However, there has been a problem that the mechanism is complicated and is economically expensive. In addition, JP-A-63-105854 and JP-A-62-138513.
The publication discloses a technique relating to a temporary holding device that applies a temporary holding force in a direction orthogonal to the spindle axis direction. However, in the above-described conventional temporary holding device, the temporary holding force absorbs a part of the energy for pressing the tool holder from the rear side, and further requires a force for holding the tool holder in the spindle. . Therefore, Japanese Patent Laid-Open No. 63-105
In the techniques disclosed in Japanese Patent Publication No. 854 and Japanese Utility Model Laid-Open No. 62-138513, when the tool holder is pressed from the rear with a large force, the tool holder may jump out from the tool insertion hole of the spindle. Such a tool pop-out can be prevented by providing a holding mechanism that holds the tool holder with a large force from a direction orthogonal to the spindle axis, but it is very structurally difficult to incorporate the above-mentioned holding mechanism into the spindle. There is a problem that it is difficult. In addition, the tool holder, pull stud, and the like must be processed into a special shape, which causes a problem of lacking versatility.

[0005]

SUMMARY OF THE INVENTION The present invention has been made in view of the above problems, and firstly, there is no need to interlock the driving of the tool unclamping device with the operation of the automatic tool changing device. To provide a temporary holding device for a tool holder applicable to a so-called solid tool lock mechanism type in which the collet is locked after being pulled by the collet. Secondly, the holding mechanism is unnecessary and the structure of the spindle is simplified. It is possible to provide a temporary holding device for the tool holder that prevents the tool holder from popping out of the spindle even if the tool holder is pushed from behind by a large force. Thirdly, the tool holder and pull stud are processed into a special shape. It is an object of the present invention to provide a temporary holding device for a tool holder that is excellent in versatility and does not need to be formed.

[0006]

In order to solve the above problems, a temporary holding device for a tool holder in a spindle of a machine tool of the present invention is provided in a through hole of the spindle so as to be movable back and forth, and is formed at one end of the spindle. Has an engaging claw that engages with the pull stud of the tool holder inserted in the tool insertion hole at one end side, and engages or disengages the pull stud by opening and closing the engaging claw in the radial direction Collet of the tool holder to
A drawbar that is provided movably in the through hole of the main shaft and that clamps the tool holder by pulling the pull stud to the other side via the collet, and a drawbar biasing means that biases the drawbar to the other side. A cam member that is provided in the through hole and that opens and closes the engaging claw by moving the collet forward and backward; and a cam member that is provided at one end of the drawbar and that engages the collet and moves the collet forward and backward to engage the engagement. A tool including an opening / closing member that opens and closes the claw along the cam member, and a tool unclamping device that moves the drawbar to one side by pushing the drawbar from the other end side by the drawbar pressing member to unclamp the tool holder A holder temporary holding device, comprising: a tapered engaged portion formed on an inner peripheral surface on the other end side of the collet; and the collet. Provided on the other side, an engaging member having a tapered engaging portion that engages the engaged portion with which move forwards and backwards in the spindle axis direction on an outer peripheral surface of one end side,
The draw bar is moved to one side by the tool unclamping device, which comprises an urging means for constantly urging the collet to one side via the engaging member so as to bring the engaging member into contact with the collet. When this is done, the tool holder is temporarily held by the urging force of the engaging member toward one side by the urging means.

Further, the tool unclamping device is
The drawbar biasing means is provided with the tool holder via the drawbar.
Tool clasp that does not prevent pulling and clamping
Pump position and the draw bar pulls the tool holder.
Temporary holding to release the tension and put the tool holder in the temporary holding state.
Hold the position and move the draw bar to one side
Three positions of tool unclamp position for forcibly pressing the head
The draw bar pressing member can be moved between
Good. In addition, this tool unclamp device
A first piston fitted in the main body so as to move back and forth;
The second piston and these two pistons
A first cylinder chamber formed by partitioning the inside,
The second cylinder chamber and the third cylinder chamber, and the first cylinder chamber
Installed in each of the third cylinder chambers,
Pressure flow for pressure fluid to move in and out by pressing
Body entrance and exit, and the piston has moved a predetermined stroke
Sometimes, the stopper that restricts the movement of each piston and the piston
Gradual movement of the stone by moving the specified stroke
Drawbar pressing member that moves back and forth to each cylinder chamber
Pressure fluid generation to generate pressure fluid of specified pressure supplied to
Device and pressure flow generated by this pressure fluid generator
Pressure fluid switching valve for distributing body to predetermined cylinder chamber
And each piston in each cylinder chamber
Is a pressure receiving surface of a portion to which a pressing force is applied by the pressure fluid
Product from one side to A₁, A₂, A₃, A_FourThen, before
Pressure receiving area is A₁<A ₂<A₃<A_FourHas a relationship
The switching valve constantly supplies pressure fluid to the first cylinder chamber.
Pressure is applied to the third cylinder chamber by switching the port
Exhaust fluid is discharged from the second cylinder chamber while supplying fluid.
Outgoing motion, exhaust from both second and third cylinder chambers
Operation for discharging fluid, both second and third cylinder chambers
It is also possible to perform an operation of supplying a pressure fluid to the. It
In addition, when the engaging protrusion is formed on the inner peripheral surface of the collet,
It is possible to engage the engaging convex portion with one end of the opening / closing member.
The engaged portion is formed, and the draw bar is moved from the temporary holding position.
When moving to the tool unclamp position, the engagement
Move the drawbar by engaging the convex portion and the engaged portion.
Together with the collet so that it can be moved to one side
May be.

Further, the collet has a convex portion capable of contacting the tip of the opening / closing member and the pull stud on the inner peripheral surface, and stands by at the neutral position in the collet during the pulling operation of the tool holder. The collet may be formed to be movable to the one side position without interfering with the draw bar.

[0009]

The tool holder is inserted into the tool insertion hole formed at one end of the spindle. The draw bar is urged to the other side by the urging means such as a coil spring and moves to the other side in the through hole of the main shaft. At this time, the opening and closing member provided at one end of the draw bar engages with the collet to cause the collet to move. Move to the other side.
The collet moves along the cam member to close the engaging claw, and the engaging claw of the collet engages the pull stud of the tool holder to pull the tool holder to the other side to clamp the tool holder.

When the spindle is detached for exchanging the tool, the tool unclamping device is driven to move the drawbar to one side by the drawbar pressing member. This releases the pulling of the tool holder by the draw bar. Since the engaging portion of the engaging member is pressed against the engaged portion of the collet by the urging means, the collet of the engaging portion cannot move, that is, the opening / closing operation cannot be performed, Therefore, the tool holder is temporarily held by the urging force of the urging means. AT
When the tool holder is engaged with the C arm or the like and the tool holder is pulled out from the tool insertion hole, a slip occurs between the tapered engaged portion and the engaging portion, and the engaging member is Since it is pushed back to the other side against the urging force of the urging means, the engagement between the engaged portion and the engagement is released, and the temporary holding of the tool holder is released. Further, even after the tool holder is removed from the tool insertion hole, the engaging member urges the collet to one side by the urging means, so that the collet is held with the engaging claw open. To be done.

When the tool holder is inserted into the spindle, the draw bar, the opening / closing member and the collet can be moved to the other side by being pushed by the tool holder by inserting the tool holder into the tool insertion hole. Only by the operation of inserting the holder into the tool insertion hole, the engaged portion of the collet and the engaging portion of the engaging member engage with each other, and the tool holder can be temporarily held. As described above, in the temporary holding state, the ATC side does not need to send / receive a signal to / from the tool clamping / unclamping device on the spindle side, and the tool exchanging operation can be performed only by the timing of the ATC itself. In addition, the drawbar pressing member can be moved between the three positions of the tool clamp position, the temporary holding position, and the tool unclamping position. Since the tool holder can be forcibly removed by pushing the holder, it is particularly effective when the temporary holding force is strong.

In this tool unclamping device, in each cylinder chamber formed by partitioning the inside of the cylinder by two pistons, the pressure receiving area A _{1 of the} portion to which each piston is given a pressing force by the pressure fluid,
A ₂ , A ₃ , and A _4, and the relationship between these pressure receiving areas is A ₁ <
As the _{A 2 <A 3 <A 4} , and, while supplying a constant pressure fluid to the first cylinder chamber located on one side of the cylinder body, by the switching of the ports, supply pressure fluid to the third cylinder chamber While performing the operation of discharging the discharge fluid from the second cylinder chamber, the operation of discharging the discharge fluid from both the second and third cylinder chambers, and the operation of supplying the pressure fluid to both the second and third cylinder chambers. By providing the switching valve, by supplying the pressure fluid in the order of the third cylinder chamber and the second cylinder chamber, the drawbar pressing member moves stepwise from the other side position to the neutral position and the one side position, and vice versa. , Second
When the fluid is discharged in the order of the cylinder chamber and the third cylinder chamber,
The draw bar pressing member smoothly moves in stages from one side position to the neutral position and the other side position.

Further, an engaging protrusion is provided on the inner peripheral surface of the collet.
If the engaged part is provided on one end side of the open / close member, both will engage if the drawbar moves from the temporary holding position to the tool unclamp position even when the tool holder is not attached to one end of the spindle. Then, the collet can be moved to one side, and the engaging claws of the collet can be opened so that the tool holder can be received.

Further, a convex portion capable of contacting both the pull stud and the collet opening / closing portion is formed on the inner peripheral surface of the collet,
By allowing the collet to move to the one side position without interfering with the drawbar while keeping the drawbar in the neutral position, the pull stud will abut on the convex portion just by inserting the tool holder into the tool insertion hole. Since the collet is retracted to bring it into a temporary holding state, it is not necessary to put the drawbar in a so-called free state, and the structure of the tool unclamping device and the spindle can be simplified. If the tool unclamping device is configured as in claim 5, the drawbar pressing member can be reliably and quickly moved both from the one-side position to the neutral position and from the other-side position to the neutral position. Since the positioning can be stopped at the neutral position, the clamp / unclamp operation and the temporary holding operation of the tool holder can be made stable. Further, the configuration of the tool unclamping device can be simplified.

[0015]

DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS A preferred embodiment of the present invention will be described below with reference to the drawings. 1 to 5 are explanatory views of the configuration and operation of a temporary holding device for a tool holder according to an embodiment of the present invention. In each figure, (a) shows the tip of the spindle, and (b) shows the trailing end of the spindle and the tool unclamping device. In this embodiment, the machine tool provided with the automatic tool changer is described as a horizontal machine tool that supports the spindle so that the spindle axis is horizontal, but the present invention is such that the spindle axis is vertical. Needless to say, it can also be applied to a vertical machine tool that supports a spindle. A tool insertion hole 1b into which a tool holder T having a tool is inserted is formed at a tip of a spindle 1 rotatably supported by a spindle head (not shown), and a tool is inserted behind the tool insertion hole 1b. There is provided a tool clamp / unclamp means for engaging the pull stud Ta provided at the end of the holder T, pulling the clamp, and clamping the tool to insert the tool holder T into the tool insertion hole 1b.

This tool clamping / unclamping means
Engagement claw 2 that is provided in the through hole 1a of the main shaft 1 so as to be movable back and forth, and that can be opened and closed in the radial direction to engage with the pull stud Ta.
In the through hole 1a, a collet 2 having d at the tip, a cam member 3 formed to project on the inner wall surface of the through hole 1a, and opening and closing the engaging claw 2d of the collet 2 as the collet 2 moves back and forth. The drawbar 5 is supported by the drawbar support member 6 so as to be movable back and forth, and is movable forward and backward together with the drawbar 5 formed at the tip of the drawbar 5.
The collet opening / closing part 4 for moving the collet 2 by engaging the inclined part 4c formed on the outer peripheral surface of the outer diameter reducing part with the inclined hole part 2e at the rear end part of the collet 2, the drawbar support member 6, and the drawbar 5. Spring receiving member 1 externally fitted to the rear end portion
1 is provided in the through hole 1a between the spring receiving member 11 and
Drawbar urging means 10 such as a disc spring or a coil spring for urging the drawbar 5 to the rear side via the. A stopper 5a as a regulating member is provided at the rear end of the drawbar 5, and the spring receiving member 11 abuts the stopper 5a so that the urging force of the drawbar urging means 10 is applied.
Have been communicated to. When the drawbar 5 is moved rearward by the urging force of the drawbar urging means 10, the inclined portion 4c of the collet opening / closing portion 4 engages with the inclined hole portion 2e of the collet 2 to pull the collet 2 and move it backward. The engaging claw 2d of the collet 2 is closed along the shape of the cam member 3 by moving the collet 2 to the rear side.
The d engages with the pull stud Ta and pulls the tool holder T rearward, so that the tool holder T is clamped.

Reference numeral 2a is an engaging projection formed on the inner peripheral surface of the collet 2. When the tool holder T is attached to the spindle 1, the pull stud Ta is attached to the collet 2
Since the tool holder T is pulled out, the collet 2 follows the tool holder T and engages with the engaging claw 2d.
You can move forward while opening. However, when the tool holder T is not attached to the main shaft 1, the collet 2 at the retracted position is advanced together with the drawbar 5 to open the engaging claw 2d, so that the tool holder T can be received. There is a need. Therefore, in this embodiment, an engaging projection 2a is formed on the inner peripheral surface of the collet 2, and a tip engaging portion 4a as an engaged portion capable of engaging with the engaging projection 2a is provided on the collet opening / closing portion 4. It is provided on the tip side of. Then, when the draw bar 5 advances, the collet 2 can be advanced by engaging the tip end engaging portion 4a with the engaging convex portion 2a. Further, reference numeral 3c is a cam provided on the front side of the cam member 3, and the engaging claw 2d is forcibly released by engaging the tip of the collet 2 with the cam 3c.

A tool unclamping device 12 for releasing the pulling of the pull stud Ta by the draw bar 5 and making the tool holder T replaceable is provided on the rear side of the spindle 1. The tool unclamping device 12 includes a cylinder body 13 provided at a rear portion of a spindle head of a machine tool,
A sliding member 14 which is provided through the cylinder body 13 and is movable back and forth in the axial direction of the spindle, and the sliding member 14
And a second pressing member 16 as a draw bar pressing member provided so as to pass through the center of the. Then, when the tool unclamping device 12 is driven and the draw bar 5 is pushed forward by the second pressing member 16, the engagement between the inclined portion 4c of the collet opening / closing portion 4 and the inclined hole portion 2e is released.
The clamp of the tool holder T by the draw bar 5 is released.

Next, the structure of the collet holding means for holding the tool holder T by restricting it so that the collet 2 does not move even if the pulling of the collet 2 and the tool holder T by the draw bar 5 is released will be described. The collet holding means 7 is provided on the rear side of the collet 2, and has a tapered engaged portion 2c formed on the inner peripheral surface on the rear end side of the collet 2,
A sleeve 8 which is housed in a hole 6a formed at the tip of the drawbar support member 6 so as to be able to move back and forth, and the outer peripheral surface of the tip is formed as a tapered engagement portion 8a that can be engaged with and disengaged from the engaged portion 2c; , The sleeve 8 is fitted in the hole 6a and the sleeve 8 is always collet 2
And a spring 9 as a biasing means for biasing the side.

When the collet 2 is pulled rearward through the collet opening / closing portion 4 by the urging force of the draw bar urging means 10, the collet 2 moves along the cam member 3 and engages with the pull stud Ta of the tool holder T. Pull. Then, by pressing the inclined hole portion 2e at the rear end of the collet 2 with the inclined portion 4c, the inclined surface 2f formed on the outer peripheral surface on the rear end side of the collet 2 is inclined at the rear end of the cam member 3. Surface 3a
, The collet is fixed by the component force of this inclination angle, and the tool holder T is clamped. Further, the sliding member 14 is provided with a first pressing member 15 as a spring pressing member. Then, the first pressing member 15 is
The pressing member 16 comes into contact with the spring receiving member 11 slightly earlier than the pressing member 16 comes into contact with the rear end of the draw bar 5. When the tool unclamping device 12 is driven and the sliding member 14 moves forward during tool exchange, the spring receiving member 11 is externally fitted to the drawbar 5 so as to be movable back and forth. The member 11 is pushed and moved forward along the drawbar 5, the spring receiving member 11 is separated from the stopper 5a, and the biasing force of the drawbar biasing means 10 is released from the drawbar 5.

That is, in FIG. 1B, the distance L ₁ from the end surface of the spring receiving member 11 that is in contact with the stopper 5a to the tip of the first pressing member 15 that is in the most retracted state together with the sliding member 14, Rear end of draw bar 5 and second pressing member 1
The relationship between the tip of 6 and the distance L ₂ is L ₁ <L ₂ . Therefore, when the tool unclamping device 12 is driven and the sliding member 14 moves forward, the second pressing member 16
Before the first pressing member 15 comes into contact with the spring receiving member 11 to push the spring receiving member 11, the spring receiving member 11 is advanced along the drawbar 5, and the urging force of the drawbar 5 by the drawbar urging means 10 is applied. The drawbar 5 is released and put in a so-called free state. Further, by advancing the spring receiving member 11 along the drawbar 5, a gap S (see FIG. 2B) is formed between the stopper 5a and the spring receiving member 11, so that the drawbar 5 is separated by the gap S. Will be able to move forward with little force.

The spring receiving member 11 is attached to the first pressing member 15,
The draw bar 5 is pushed by the second pressing member 16 and the draw bar 5 advances, so that the inclined portion 4c of the collet opening / closing portion 4 becomes the inclined hole portion 2e.
(See Fig. 2 (a)). This makes the drawbar 5
The pulling of the pull stud Ta by the is released. However, since the engaging portion 8a of the sleeve 8 pushes the engaged portion 2c of the collet 2 with the biasing force of the spring 9, the collet 2 cannot move forward. Therefore, the tool holder T is temporarily held while being engaged with the collet 2.
The magnitude of this temporary holding force is affected by the magnitude of the biasing force of the spring 9 that presses the sleeve 8 against the collet 2, but in the main spindle 1 where a heavy and large tool may be attached, a large spring constant is obtained. In the main shaft 1 to which a relatively small tool having a light weight is attached, those having a small spring constant may be used.

The temporary holding of the tool holder T due to the engagement between the engaging portion 8a and the engaged portion 2c can be released by pulling the tool holder T forward. ATC
When the V-shaped groove for gripping the tool holder T is gripped by the arm 20 (see FIG. 3) or the like and the tool holder T is pulled out to the front side,
The collet 2 whose engaging claw 2d is engaged with the pull stud Ta advances. Thereby, the engaged portion 2c and the engaging portion 8a
A slip occurs between the sleeve 8 and the sleeve 8, and the sleeve 8 is pushed back to the rear side along the slope of the engaged portion 2c against the biasing force of the spring 9. Further, the engagement between the inclined surface 2f of the collet 2 and the inclined surface 3a of the cam member 3 is released, and the inclined surface 2f is located in the inner diameter portion 3b of the cam member 3. That is, the collet 2 is in a state where the grip portion 2d side is opened, the engagement between the engaged portion 2c and the engaging portion 8a is released, and the temporary holding of the tool holder T is released. However, since the collet 2 is biased forward by the spring 9 via the sleeve 8, the tool holder T
Even after being removed, the collet 2 does not move backward, and the engaging claw 2d is held in the open state. When the next tool holder T is not attached to the spindle 1, the drawbar 5 is retracted, the collet 2 is also retracted, and the state shown in FIG.

As described above, in this embodiment, the temporary holding device can temporarily hold the tool holder T only by inserting the tool holder T into the tool insertion hole 1b. By configuring the temporary holding device as in this embodiment, not only when the tool holder T is removed from the spindle 1, but also when the tool holder T is inserted into the spindle 1, the tool holder T is inserted into the tool insertion hole 1b. Since the temporary holding state can be achieved even when the tool is inserted, there is an effect that the tool replacement time can be further shortened. A contact portion 4b extending forward from the tip engaging portion 4a is formed at the tip of the collet opening / closing portion 4. The contact portion 4b contacts the pull stud Ta of the tool holder T inserted in the tool insertion portion 1b,
By pushing the tool holder T, the temporary holding of the tool holder T is forcibly released.

Next, the structure of the tool unclamping device 12 will be described. In this embodiment, the tool unclamping device 1
2 is a position where the drawbar 5 does not come into contact, that is, the drawbar 5 pulls the pull stud Ta by the urging force of the drawbar urging means 10 to clamp the pull stud Ta (retracted position), and the drawbar 5 pulls the tool holder T. The sleeve 8 presses the collet 2 by the urging force of the spring 9 to temporarily hold the tool holder T (neutral position), and the drawbar 5 is advanced by another step to release the clamp of the tool holder T. The first pressing member 15 and the second pressing member 16 can be moved between the three positions of the tool unclamping position (advancing position).
Of course, if the temporary holding of the collet 2 can be released only by the pulling-out operation of the ATC arm, the tool unclamping device 12 that can move the second pressing member 16 between the three positions as described above can be used. There is no particular need to provide it. In such a case, a known tool unclamping device having a stroke that can advance the collet opening / closing part 4 together with the drawbar 5 to separate the inclined part 4c and the inclined hole part 2e of the collet 2 from each other. .

The tool unclamping device 12 includes a sliding member 1.
Two pistons 14a for moving 4 in stages,
14b. That is, the small diameter portion formed on the rear end side of the sliding member 14 in the first cylinder chamber 13a formed on the main shaft side in the cylinder body 13 has the first piston 1
4a is externally fitted along the sliding member 14 so as to be movable back and forth,
The sliding member 1 is provided in front of the first piston 14a.
A second piston 14b is formed by cutting the outer peripheral surface of No. 4. A cylindrical third piston 17 that moves forward and backward together with the first piston 14a in the first cylinder chamber 13a is provided on one side of the first piston 14a. A second cylinder chamber 17a is formed in the inner diameter portion of the third piston 17. The second piston 14b is fitted in the second cylinder chamber 17a in the third piston 17 so as to be movable back and forth. Oil passages 21a, 21b, 21c are opened at the rear end side, the intermediate portion, and the front end side of the first cylinder chamber 13a, respectively.
By supplying pressure oil as pressure fluid from the oil passages 21a, 21b, 21c to move the first piston 14a and the second piston 14b stepwise, the first pressing member 1
5 and the second pressing member 16 can be moved between the three positions described above. Reference numeral 17b is the third piston 17
Is a hole formed so as to penetrate between the inner and outer diameters of the oil passage 21.
The pressure oil supplied from b can be supplied between the first and second pistons 14a and 14b through the hole 17b.

Further, in the figure, reference numerals 22a, 22b, 2
Reference numeral 2c is a limit switch for detecting whether the sliding member 14 is at the most advanced position, the neutral position or the most retracted position. The limit switches 22a and 22b are arranged on the bracket 23 attached to the cylinder main body 13 which is a fixed portion in the front and rear directions in parallel with the spindle axis. The operating rod 25 that is turned on (or turned off) by pressing the limit switches 22a and 22b is the limit switch 22.
It is provided between a and 22b and is attached to the sliding member 14 so that it can move forward and backward together with the sliding member 14. Then, when the sliding member 14 moves to the most retracted position, the operating rod 25 pushes one of the limit switches 22a to turn it on (or off), and when the sliding member 14 moves to the most advanced position, the operating rod 25 moves to the other position. The limit switch 22b is pressed to turn it on (or off).

On the other hand, the limit switch 22c detects that the sliding member 14 has moved to the neutral position, and is attached to the bracket 24 extending downward from the bracket 23. The piece 26 that presses the limit switch 22c to turn it on (or off) is attached to the other end side of the second pressing member 16 extending from the rear of the cylinder body 13. When the sliding member 14 moves from the last retracted position to the neutral position, the piece 26 moves the limit switch 22c.
Press to turn it on (or off). When the sliding member 14 moves to the most forward position, the limit switch 22b and the limit switch 22c are pushed.
Limit switch 22c is pressed to turn on (or off)
Is the neutral position (temporary holding position),
When only the limit switch 22c is pressed to output the temporary holding position signal, the ATC can change the tool only at the ATC's own timing. That is, when in the temporary holding state, the ATC can always perform the tool changing operation.

Next, the operation of the present invention having the above construction will be described with reference to FIGS. FIG. 1 shows a state in which the tool holder T is clamped. In the tool holder T inserted into the spindle insertion portion 1b, the engagement claw 2d of the collet 2 engages with the pull stud Ta, and the drawbar biasing means 10 biases the drawbar 5 and the collet opening / closing portion 4 to the rear. Has been pulled and clamped. At this time, the sliding member 1
4 is in the last retracted position, and the operating rod 25 pushes the limit switch 22a to turn it on (or off).

FIG. 2 is a view showing a state in which the tool holder T is temporarily held. When exchanging tools, the spindle 1 is stopped at a predetermined rotation angle position and the tool unclamping device 12 is driven separately from the operation of the ATC. First cylinder chamber 1
By supplying the pressure oil from the oil passage 21a to one of the chambers 3a, the first piston 14a moves forward until the end face of the third piston 17 comes into contact with the tip face of the first cylinder chamber 13a. The sliding member 14 is pushed by the first piston 14a and advances to the neutral position. At this time, the piece 26 pushes the limit switch 22c to be turned on (or off).
When the limit switch 22C outputs a signal indicating that the tool holder T is in the temporary holding state, the ATC can always pull out and insert the tool holder T only at its own timing.

When the sliding member 14 advances to the neutral position,
First, the first pressing member 15 contacts the spring receiving member 11 to push the spring receiving member 11 and move the spring receiving member 11 along the draw bar 5. Since the spring receiving member 11 advances along the drawbar 5 and separates from the stopper 5a, the urging force of the drawbar 5 by the drawbar urging means 10 is released and the drawbar 5 becomes free. On the other hand, the second pressing member 16 contacts the rear end of the drawbar 5 slightly later than the first pressing member 15, and pushes the drawbar 5 to move it forward. After this, the draw bar 5 and the spring receiving member 11 move forward integrally, and the size of the gap S between the stopper 5a and the spring receiving member 11 at this time is L ₁ -L ₂ (L ₁ , L ₂ is maintained in Figure 1). With the advance of draw bar 5,
The engagement between the inclined portion 4c of the collet opening / closing portion 4 and the inclined hole portion 2e of the collet 2 is released. As a result, the pulling force by the collet opening / closing part 4 is released, but the collet 2 cannot move due to the pressing of the sleeve 8 by the spring 9 of the collet holding means 7, so that the tool holder T is engaged with the collet 2. It will be temporarily held as it is.

FIG. 3 is a view showing a state where the temporary holding of the tool holder T is released and the tool holder T is detached from the tool insertion hole 1b. The arm 20 of the ATC pivots to the front of the spindle 1 and engages the tool holder T in the grip groove,
Is pulled forward to pull it out from the tool insertion hole 1b, a slip occurs between the engaged portion 2c and the engaging portion 8a, and the sleeve 8 retracts, and the engaged portion 2c of the collet 2 and the sleeve 8 are retracted. Is disengaged from the engaging portion 8a and the temporary holding state of the tool holder T is released. The collet 2 is pulled by the tool holder T and moves forward while opening the engaging claw 2d. Simultaneously with the operation of pulling out the tool holder T in front of the ATC, pressure oil is supplied to the oil passage 21b to move the second piston 14b forward. The draw bar 5 is advanced by the second piston 14b, and the contact portion 4b pushes out the pull stud Ta. When the ATC removes the tool holder T and shifts to the next operation, the oil passage 21b
Stop supplying pressure oil to the. The urging force of the drawbar urging means 10 causes the first pressing member 15 and the second pressing member 16 to retract, and a predetermined gap is created between the drawbar 5 and the second pressing member 16. In this state, it waits for the next tool holder T to be inserted into the tool insertion portion 1b.

When the temporary holding force of the tool holder T due to the engagement between the collet 2 and the sleeve 8 is large, as shown in this embodiment, the first through the oil hole 21b.
By supplying pressure oil between the piston 14a and the second piston 14b, the sliding member 14 is moved from the neutral position to the most advanced position, the draw bar 5 is advanced, and the abutment part 4b of the collet opening / closing part 4 is used at the tool holder. The temporary holding may be released by forcibly pushing out T. When the ATC arm 20 disengages the tool holder T and shifts to the next operation, the supply of pressure oil to the oil passage 21b is stopped. By the urging force of the draw bar urging means 10, the first pressing member 15 and the second pressing member 15
The pressing member 16 retracts, and the draw bar 5 and the second pressing member 16
A predetermined gap is created between In this state, it waits for the next tool holder T to be inserted into the tool insertion hole 1b.

FIG. 4 shows the tool holder T removed from the spindle 1. In this state, the sliding member 1
4 is retracted from the most advanced position to the neutral position, and a gap S'is formed between the rear end of the draw bar 5 and the front end of the second pressing member 16. This state is the temporary holding state at the time of insertion, and only the limit switch 24c is pressed,
It can be detected by outputting a signal. In this state, the ATC inserts the tool holder T into the tool insertion hole 1b,
The end surface of the pull stud Ta is the contact portion 4 of the collet opening / closing portion 4.
The collet opening / closing part 4 and the draw bar 5 are pushed rearward by contacting b. That is, the collet opening / closing part 4 and the drawbar 5
Can be retracted by the gap S'described above. When the collet opening / closing part 4 and the drawbar 5 retract,
The collet 2 retracts while engaging the pull stud Ta with the engaging claw 2d, and the engaged portion 2c and the engaging portion 8a engage with each other to be in the temporary holding state shown in FIG. The ATC releases the engagement of the tool holder T at a timing unique to the ATC and shifts to the next operation.

After the tool holder T is temporarily held, the supply of pressure oil to the oil passage 21a is stopped, the pressure oil is supplied to the oil passage 21c, and the second piston 14b is retracted. In this way, the tool unclamping device 1 is driven to move the sliding member 14 to the most retracted position, and the pull stud Ta of the tool holder T is pulled by the draw bar 5 and the collet opening / closing part 4 to obtain the clamped state shown in FIG. To do. FIG. 5 is a view for explaining the action of the engaging protrusion 2a and the tip engaging portion 4a when the tool holder T is not attached to the spindle 1. When the drawbar 5 advances from the temporary holding position (the position shown in FIG. 2) to the tool unclamping position (the position shown in FIG. 4) in a state where the tool holder T is not attached to the main shaft 2, the engaging convex portion 2a is exposed. The tip engaging portion 4a is engaged, and the collet opening / closing portion 4 becomes the collet 2.
By pressing, the collet 2 can move forward to release the engaging claw 2d.

Next, another embodiment of the temporary holding device and the tool unclamping device will be described with reference to FIGS. The same parts and members as those of the first embodiment described above are designated by the same reference numerals and detailed description thereof will be omitted. In this embodiment, the engaging claw 2d 'and the inclined hole 2e' of the collet 2'are provided.
A convex portion 2a 'is formed on the inner peripheral surface between the and. The projecting portion 2a 'has a pull stud Ta of the tool holder T inserted into the tool insertion hole 1b when the collet 2'is in the forward position with the engaging claw 2d' in the open state.
And the collet 2'is in the retracted position for clamping the tool holder T, the tip of the pull stud Ta has the engaging claw 2d 'and the convex portion 2a'.
It is located between and (see FIGS. 8 and 6). Further, this convex portion 2a 'can also come into contact with the tip portion 4a of the collet opening / closing portion 4 provided at the tip of the draw bar 5,
While the draw bar 5 moves from the neutral position to the forward position, the tip 4a of the collet opening / closing part 4 abuts the convex portion 2a 'and pushes the collet 2', so that the collet 2'is moved to the advanced position together with the collet opening / closing part 4. It can be moved.

On the other hand, the inner peripheral surface of the collet 2'between the convex portion 2a 'and the inclined hole portion 2e' is formed in a flat shape unlike the above-mentioned first embodiment, and the collet opening / closing portion is provided before and after the neutral position. Four
And the collet 2'do not interfere with each other. That is, only the collet 2'can be moved to the forward position with the pulling operation of the tool holder T without interfering with the collet opening / closing part 4 standing by at the neutral position, and the tool holder T into the tool insertion hole 1b can be moved. The collet 2'can be retracted by the inserting operation of (1) to be put in a temporary holding state. By constructing the collet 2'in this way, the tool holder T can be pulled out from the tool insertion hole 1b or inserted into the tool insertion hole 1b with the drawbar 5 in the neutral position. Since it can be temporarily held, the tool unclamping device and the spindle can be simplified in structure.

Reference numeral 3c 'denotes a cam formed in front of the cam 3 as in the case of the first embodiment, and is a collet 2'compulsively pushed forward by the draw bar 5 or a tool holder. The tip of the collet 2'protruded by the pulling-out operation of T engages with the cam 3c ', so that the engaging claw 2d' can be held in an open state. In this embodiment, the cam 3c 'is formed so that the inclination angle near the inlet into which the tip of the collet 2'is inserted is gentler than that of the cam 3c of the first embodiment (see FIG. 1). Thus, the engagement claw 2d 'can be opened and closed by the engagement of the cam 3c' and the tip of the collet 2'with a comparatively light force. Then, by inserting the tool holder T into the tool insertion hole 1b and pushing the convex portion 2a 'with the pull stud Ta, a slip occurs between the collet 2'and the cam 3c', and the engaging claw 2
The collet 2'retracts while closing d '.

Next, the temporary holding mechanism in this embodiment will be described. The temporary holding mechanism in this embodiment is almost the same as that of the first embodiment described above, except that the stopper portion 8 that engages with the sleeve 8 ′ between the cam 3 and the drawbar support member 6.
b'is provided so that the forward movement position of the sleeve 8'is regulated. In the above-described first embodiment, when the collet 2 is located at the most advanced position, the sleeve 8 pushes from the rear side to restrict the retreat of the collet 2, but in this embodiment, it is engaged with the tip of the collet 2 '. Since the cam 3c 'that can hold the engaging claw 2d' in the opened state is provided, it is not necessary to constantly bias the collet 2'from the rear side. With this configuration, it is not necessary to push the collet 2'to the rear side against the urging force of the spring 9 even when the tool holder T is manually inserted, so that the tool holder T can be easily inserted by hand. It can be inserted into the fitting hole 1b and temporarily held.

Next, the structure of the tool unclamping device in this embodiment will be described. In this embodiment, the tool unclamping device 29 includes a pressing member 3 which is a piston rod.
2 is a position not contacting the drawbar 5, that is, the drawbar 5 pulls and clamps the pull stud Ta by the urging force of the drawbar urging means to clamp it (retracted position), and the pulling of the tool holder T by the drawbar 5 is released. The urging force of the spring 9 causes the sleeve 8'to temporarily hold the tool holder T in the temporary holding position (neutral position), and the draw bar 5 to move forward by another step to forcibly move the collet 2 ', and the cam 3c'. Like the first embodiment, it can be moved between three positions of the tool unclamping position (advancing position) for holding the collet 2'in the opened state by engaging the collet 2'and the tip of the collet 2 '. Is.

The tool unclamping device 29 includes the pressing member 3
Two pistons 31a for moving 2 in stages,
31b. As shown in the figure, the first piston 3
1a is a large diameter hole portion 35 formed in the cylinder body 30.
The second piston 31b is slidably fitted in the small diameter hole portion 37. The large diameter hole 3 of the cylinder body 30
5 and the small-diameter hole 37 are the first piston 31a and the second
Partitioned by the piston 31b, a first cylinder chamber 30a, a second cylinder chamber 30b, and a third cylinder chamber 30c are formed in order from the main shaft 1 side. The rear end portion of the pressing member 32 is formed as a small diameter portion, and the first piston 31a is externally fitted to the small diameter portion so as to be movable back and forth along the pressing member 32. A second piston 31b is integrally formed with the pressing member 32 on the front side of the first piston 31a. The first cylinder chamber 30a, the second cylinder chamber 30b,
Oil passages 33a, 33 are provided in the third cylinder chamber 30c, respectively.
b, 33c are opened, and these oil passages 33a, 33b, 33
The pressure oil is supplied from c, and the first piston 31a and the second piston 31a
By moving the piston 31b stepwise, the pressing member 32 can be moved between the above-mentioned three positions.

In the tool unclamping device 29 in this embodiment, the pressure receiving area of the portion where the second piston 31b is pressed by the pressure oil in the first cylinder chamber 30a is A ₁ , and the second piston 31b is Second cylinder chamber 30
The pressure receiving area of the portion where the pressing force is applied by the pressure oil in b is A ₂ , and the pressure receiving area of the portion where the first piston 31a is pressed by the pressure oil in the second cylinder chamber 30b is A ₃ the pressure receiving area of the portion where the piston 31a is given a pressing force by a hydraulic fluid of the third cylinder chamber 30c in the case of the a _4, relationship between these pressure receiving areas a ₁ to a ₄ is a ₁ <a ₂ <a
₃ <A _4, and the size becomes larger as it goes to the rear end of the cylinder 30. In particular, in the first piston 31a, the pressure receiving area A ₃ of the portion of the second cylinder chamber 30b to which the pressing force is applied by the pressure oil has the third cylinder chamber 30
In order to make the pressure receiving area A ₄ smaller than the pressure receiving area A ₄ , the hole 39 is bored, and the second piston 31
A stepped portion 36 formed at the rear of b is fitted. Then, in order to prevent pressure oil from penetrating into the hole 39 from between the inner peripheral surface of the hole 39 and the outer peripheral surface of the stepped portion 36, the inner peripheral surface of the hole 39 concentric with the pressing member 32 is provided. Is packing, X
A seal member 39a such as a ring or an O-ring is fitted. It should be noted that the depth of the hole 39 is such that the second piston 31b moves from the neutral position to the forward position so that the fitting state with the stepped portion 36 can be maintained even when the second piston 31b moves from the neutral position to the forward position. It must be larger than the stroke of the piston 31b.

By configuring in this way, each syrin
Supply pressure oil of pressure p to each of the chambers 30a, 30b, 30c.
If you pay₁~ A_FourNo matter how the value of
The pressure receiving area of the part where the pressing force is applied by oil is A₁<A
₂<A₃<A_FourAs long as there is a relationship such as (pA₁-PA₂
+ PA₃) <PA_FourIs always satisfied (pA ₂
For, since the direction of action of force is opposite, the sign is minus
Become). Therefore, the pressure of the pressure p is applied to the first cylinder chamber 30a.
Only in the third cylinder chamber 30c with oil constantly supplied
When the pressure oil having the pressure p is supplied, the first piston 31a moves to the second piston 31a.
Neutral position while pressing the piston 31b and the pressing member 32
The second cylinder chamber 30b, the third cylinder chamber
If pressure oil is supplied to both 30c,
2nd fix with the position of 1st piston 31a maintained
The front end of the cylinder 31b contacts the inner wall of the first cylinder chamber 30a.
Move forward until In addition, the first cylinder chamber 30a and the third cylinder
The second cylinder chamber with pressure oil being supplied to the binder chamber 30c
When the pressure oil is discharged from 30b, the second piston 31b moves to the middle
The pressure supplied to the third cylinder 30c is retreated to the upright position.
1st fixer that has moved forward to a neutral position and stopped due to oil
Abutting against the carriage 31a and stopping.

A stopper 34 is provided at the rear end portion of the piston rod of the first piston rod 31a protruding rearward of the cylinder body 30, and the first piston 31a
The stopper 34 is brought into contact with the end surface of the cylinder body 30 to stop at the neutral position.
Of course, the advance position can be regulated by providing the first piston 31a against the inner wall of the cylinder body 30 without providing such a stopper 34, but the stopper 34 is screwed into the piston rod to move forward and backward. By making it adjustable, the stroke of the first piston 31a can be easily adjusted. At the rear end of the drawbar 5, there is a disc 28 that moves back and forth together with the drawbar 5.
Is attached to the fixed portion of the tool unclamping device 29, and a detection means 27 such as a proximity switch or a photoelectric switch is attached via a bracket 27a. The detecting means 27 is arranged so as to face the outer peripheral surface of the disk body 28 in a state where the tool holder T is inserted into the tool insertion hole 1b and pulled by the draw bar 5 and clamped. Is clamped, the outer peripheral surface is detected and a clamp state confirmation signal is output.

In order to move the pressing member 32 forward and backward in a stepwise manner among the three positions of the retracted position, the neutral position and the advanced position, pressure oil is supplied in the order of the third cylinder chamber 30c and the second cylinder chamber 30b. Further, the pressure oil must be discharged in the order of the second cylinder chamber 30b and the third cylinder chamber 30c. For that purpose, a valve may be provided in each of the oil passages 33b and 33c, and each valve may be individually opened and closed to supply or discharge the pressure oil, but a switching valve as described below is provided. As a result, the pressing member 32 can be moved back and forth stepwise between the three positions with a single switching valve.

FIG. 11 is a schematic explanatory view of a three-position switching valve (hereinafter referred to as switching valve) for supplying pressure oil to the cylinder body 30 of the tool unclamping device 29. Switching valve 4
0 is capable of switching the supply direction of the pressure oil to the A port and the B port by exciting the solenoids SOL1 and SOL2. In this embodiment, the first cylinder chamber 30a is directly connected to the hydraulic pressure supply source 41 via the oil passage 33a, and pressure oil having a constant pressure is constantly supplied. Therefore, the switching operation of the pressure oil supplied to or discharged from the second cylinder chamber 30b and the third cylinder chamber 30c is performed by the three-position valve 40. That is, the solenoid SOL1
When the solenoid SOL2 is in the non-operating state, both the A port and the B port are connected to the T port (the state shown in the figure), and the pressure oil is applied only to the first cylinder chamber 30a through the oil passage 33a. It is being supplied. Further, since the discharge oil in the second cylinder chamber 30b and the third cylinder chamber 30c is discharged to the tank 42 side through the oil passages 33b and 33c, the pressure oil in the first cylinder chamber 30a is pushed. The pressure causes the first and second pistons 31a and 31b to retract and the pressing member 32 to retract.

The solenoid SOL1 of the switching valve 40 is excited
Then, A port and T port, B port and P port are connected
Is done. As a result, the oil discharged from the second cylinder chamber 30b is
The third cylinder chamber 30 is discharged while being discharged to the tank 42 side.
Pressure oil is supplied to c. Pressure receiving surface of the first cylinder chamber 30a
Product A₁From the pressure receiving area A of the third cylinder chamber 30c_FourIs better
Since it is large, the first piston 31a moves forward. 1st piss
The ton 31a has a stopper 34 on the end surface of the cylinder body 30.
Since it moves forward until it abuts, the pressing member 32 moves to the neutral position.
To position. Next, the solenoid SOL2 is excited and the A port
Switch to the state in which the P port is connected to the B port.
Then, the first to third cylinder chambers 30a, 30b, 3
Pressure oil will be supplied to all of 0c. No. 1 Shirin
Pressure receiving area A on the chamber side 30a ₁Second cylinder chamber 30
Pressure area A on b side₂Is larger, so the first piston 3
1a of the second piston 31a while being maintained in the neutral position
Move forward and the pressing member 32 moves to the forward position.
Become.

Next, the operation of the temporary holding mechanism and the tool unclamping device 29 in this embodiment will be described with reference to FIGS.
1 will be described. As shown in FIG. 7, when exchanging tools, the spindle 1 is stopped at a predetermined rotation angle position (spindle orientation position), and the tool unclamping device 29 is driven separately from the operation of the ATC. When the solenoid SOL1 (see FIG. 11) of the switching valve 40 is excited while the pressure oil is being supplied to the first cylinder chamber 30a and the pressure oil is supplied to the third cylinder chamber 30c, the first piston 31a causes the second piston 31a to move to the second cylinder 31a.
Since the stopper 34 moves forward while pressing the piston 31b until it comes into contact with the cylinder cover, the pressing member 32 moves to the neutral position and stops. As a result, the front end portion 32a of the pressing member 32 comes into contact with the rear end of the draw bar 5 and the draw bar 5
Since the drawbar 5 is pushed to enter the temporary holding state in which the tension of the tool holder T is released, the ATC can pull out and insert the tool holder T at any time with its own timing. At this time, the collet opening / closing part 4 at the tip of the draw bar 5 stands by between the convex part 2a 'of the collet 2'and the inclined hole part 2e', and the collet 2'moves from the temporary holding position to the forward position. However, it does not interfere with the collet 2 '.

FIG. 8 is a view showing a state in which the temporary holding of the tool holder T is released and the tool holder T is disengaged from the tool insertion hole 1b. An ATC arm (not shown) pivots to the front of the spindle 1 and engages with the tool holder T in the grip groove,
When the tool holder T is pulled forward to pull it out from the tool insertion hole 1b, the pull stud Ta advances the collet 2 and the cam 3c 'opens the engaging claw 2d side. Then, the engaged portion 2c of the collet 2 and the engaging portion 8a of the sleeve 8 are disengaged, and the temporary holding state of the tool holder T is released. In addition, the tool holder T by ATC
It is also possible to excite the solenoid SOL2 at the same time as the pulling-out operation described above to supply pressure oil to both the A port and the B port, and move the second piston 31b forward. As a result, the pressing member 32 is positioned at the forward position and presses the drawbar 5 at the neutral position (see FIG. 9), so that the collet opening / closing part 4 presses the pull stud Ta via the convex part 2a, and the tool holder T is used as a tool. It can be forced out from the insertion hole 1b. When the ATC disengages the tool holder T and shifts to the next operation, the supply of pressure oil to the second cylinder chamber 30b is stopped. As a result, the pressing member 32 retracts to the neutral position as the second piston 31b retracts, so that the drawbar 5 also retracts to the neutral position by the biasing force of the drawbar biasing means 10.
The collet 2'is held with its tip engaged with the cam 3c 'and the engagement claw 2d' being opened. In this state, it waits for the next tool holder T to be inserted into the tool insertion hole 1b.

FIG. 10 shows the tool holder T removed from the spindle 1. In this state, the pressing member 3
The drawbar 2 and the drawbar 5 are retracted to the neutral position and can be temporarily held only by inserting the tool holder T. A
In this state, the TC can insert the tool holder T into the tool insertion hole 1b at any time, and by this insertion operation, the end surface of the pull stud Ta abuts the convex portion 2a and pushes the collet 2 rearward. At this time, since the collet opening / closing section 4 is located at the neutral position where it does not interfere with the collet 2, the collet 2 and the collet opening / closing section 4 do not interfere with each other even when the collet 2 is retracted to the temporary holding state. When the collet 2 retracts, the engaging claw 2d of the collet 2 is pulled by the pull stud Ta.
While retracting, the engaged portion 2c and the engaging portion 8a are engaged with each other to be in the temporary holding state shown in FIG. ATC is AT
At the timing unique to C, the engagement of the tool holder T is released and the next operation is performed.

After the tool holder T is temporarily held, the solenoids SOL1 and SOL2 are de-excited to connect the A port and the B port to the T port, and to discharge the second cylinder chamber 30b and the third cylinder chamber 30c. Oil tank 4
Discharge to 2. By supplying the pressure oil to the first cylinder chamber 30a, the first piston 31a and the second piston 31b are retracted from the neutral position. In this way, the tool unclamping device 29 is driven to move the pressing member 32 to the retracted position, and the pull stud Ta of the tool holder T is pulled by the draw bar 5 and the collet opening / closing part 4 to be in the clamped state shown in FIG. When the tool holder T is not attached to the spindle 1, the pressing member 32 is at the retracted position,
The draw bar 5 pulls the collet 2 ′ rearward by the biasing means 10. In order to insert the tool holder T into the spindle 1 by manual operation, the switching valve 40 is manually operated. That is, first, the solenoid SOL2 is excited to position the pressing member 32 at the forward position, and the draw bar 5 advances the collet 2'to open the engaging claw 2d '. After that, the solenoid SOL1 is excited to retract the drawbar 5 to the neutral position and stand by (state shown in FIG. 10). If the tool holder T is inserted into the tool insertion hole 1b in this state,
The pull stud Ta comes into contact with the convex portion 2a 'and the collet 2'
Is retracted so that it is in a temporary holding state. After that, when the solenoids SOL1 and SOL2 are deenergized, the draw bar 5 retracts to pull and clamp the tool holder T.

As in this embodiment, there is provided a three-position cylinder capable of stopping the positioning of the pressing member in any of the forward direction and the backward direction between the three positions of the forward moving position, the neutral position and the backward moving position. When used, if pressure oil is constantly supplied to the cylinder chamber in the backward direction and pressure oil is supplied to the other cylinder chambers by a switching valve, temporary holding is possible only by moving the drawbar from the forward position to the neutral position. The feature is that the collet, the temporary holding mechanism and the control means can be made simpler. Further, since the draw bar can be moved back and forth smoothly and quickly, the tool change time can be further shortened.

[0053]

Since the present invention is constructed as described above, it is not necessary to interlock the operation of the automatic tool changer with the drive of the tool unclamping device. That is, when the tool holder is detached from the spindle, the pull of the tool holder by the draw bar can be released before the ATC arm grips the tool holder T. Also, when inserting the tool holder into the tool insertion hole and inserting it into the spindle,
The tool holder can be temporarily held without checking the operation of the tool unclamp device, and the ATC can be performed immediately after insertion.
Since the arm can be moved from the tool exchange position on the spindle side, the tool exchange time can be shortened.
Further, the tool holder temporary holding device of the present invention can be applied to the solid tool lock mechanism type, and since it is not necessary to process the tool holder, the pull stud, or the like into a special shape, it is excellent in versatility. ing. Further, even if the tool holder is pushed with a large force from the rear side, the tool holder does not pop out from the spindle, and a holding mechanism for preventing the tool holder from popping out is unnecessary, so that the internal structure of the spindle can be simplified. it can.

A convex portion which can contact both the pull stud and the collet opening / closing portion is formed on the inner peripheral surface of the collet, and the collet moves to the one side position without interfering with the drawbar while keeping the drawbar in the neutral position. By making it possible, the pull stud comes into contact with the convex portion and the collet is retracted into the temporary holding state simply by inserting the tool holder into the tool insertion hole, so that the temporary holding mechanism and the tool unclamping device are configured. Can be simple. By constructing the tool unclamping device as claimed in claim 3, the drawbar pressing member can be stably operated both when moving from the one side position to the neutral position and when moving from the other side position to the neutral position. Positioning can be stopped at the neutral position.
The unclamping operation and the temporary holding operation can be made stable. Further, the configuration of the tool unclamping device can be simplified.

[Brief description of drawings]

FIG. 1 is a sectional view of a tip end portion of a spindle in a state where a tool holder is clamped, according to a first embodiment of the present invention;
6B is a cross-sectional view of the tool unclamping device and the spindle rear end portion in the state of FIG.

FIG. 2 is a cross-sectional view of the tip of the spindle in a state in which the tool holder is temporarily held according to the first embodiment of the present invention;
6B is a cross-sectional view of the tool unclamping device and the spindle rear end portion in the state of FIG.

FIG. 3 relates to the first embodiment of the present invention, (a) is a cross-sectional view of the spindle tip portion in a state where the temporary holding of the tool holder is released and the tool holder is pulled out from the tool insertion hole; FIG. 7B is a sectional view of the tool unclamping device and the spindle rear end portion in the state of (a).

FIG. 4 is a cross-sectional view of the tip of the spindle according to the first embodiment of the present invention, in which the tool holder is removed.
6B is a cross-sectional view of the tool unclamping device and the spindle rear end portion in the state of FIG.

FIG. 5 is a view for explaining the action of an engagement protrusion formed on the inner peripheral surface of the collet and a tip engagement portion formed on the collet opening / closing portion.

FIG. 6 is a cross-sectional view of the tip of the main spindle in a state where the tool holder is clamped, according to the second embodiment of the present invention;
(B) is a cross-sectional view of the tool unclamping device and the rear end portion of the spindle, showing a state in which the drawbar pressing member is located at the retracted position.

FIG. 7 relates to the second embodiment of the present invention, and (a) is a cross-sectional view of the tip of the main spindle in a state where the tool holder is temporarily held,
(B) is a cross-sectional view of the tool unclamping device and the rear end portion of the spindle, showing a state in which the drawbar pressing member is positioned at the neutral position.

FIG. 8 relates to the second embodiment of the present invention, (a) is a cross-sectional view of the spindle tip portion in a state where the temporary holding of the tool holder is released and the tool holder is pulled out from the tool insertion hole; FIG. 7B is a sectional view of the tool unclamping device and the spindle rear end portion in the state of (a).

FIG. 9 is a cross-sectional view of the tip of the main spindle showing a state in which the tool holder is pulled out and the collet is positioned at the forward position according to the second embodiment of the present invention, and (B) shows the drawbar pressing member. It is sectional drawing of a tool unclamping device and a spindle rear end part which shows the state which advanced the collet to the advance position from the neutral position.

FIG. 10 is a cross-sectional view of the tip end of the spindle showing the state of the collet after the tool holder is pulled out and the collet opening / closing part that stands by at the neutral position.

FIG. 11 is a schematic explanatory view of a switching valve according to the tool unclamping device in the second embodiment.

[Explanation of symbols]

T Tool holder Ta Pull stud 1 Spindle 1a Through hole 1b Tool insertion hole 2 Collet 2a Engagement protrusion 2c Engagement part 2d Engagement claw 4 Collet opening / closing part 4a Tip engaging part (engagement part) 4b Abutment Part 5 Drawbar 5a Stopper (regulating member) 7 Collet holding means (holding means) 8 Sleeve (engaging member) 8a Engaging portion 9 Spring (biasing means) 10 Drawbar urging means 11 Spring receiving member 12, 29 Tool unclamp Device 14 Sliding member 14a, 31a First piston 14b, 31b Second piston 15 First pressing member (spring pressing member) 16 Second pressing member (drawer pressing member) 17 Third piston 17a Second cylinder chamber 20 Arm 22a, b, c limit switch 40 switching valve

Claims (5)

[Claims] 1. A pull stud of a tool holder (T) which is provided in a through hole (1a) of a spindle (1) so as to be movable back and forth and is inserted into a tool insertion hole (1b) formed at one end of the spindle. A collet (2) for a tool holder that has an engaging claw (2d) that engages with (Ta) at one end side and that engages or disengages the pull stud by opening and closing the engaging claw in the radial direction. And is installed in the through hole of the spindle so that it can move back and forth,
A draw bar for clamping the tool holder by pulling the pull stud to the other side via the collet, a draw bar biasing means (10) for biasing the draw bar to the other side, and a draw bar provided in the through hole. A cam member (3) for opening and closing the engaging claw by moving the collet forward and backward.
And an opening / closing member (4) which is provided at one end of the draw bar and which engages with the collet and moves the collet forward and backward to open and close the engaging claw along the cam member.
And a tool unclamping device for unclamping the tool holder by pushing the drawbar from the other end side by the drawbar pressing member (16) to move the drawbar to one side, A tapered engaged portion (2c) formed on the inner peripheral surface on the other end side of the collet, and an engaged portion which is provided on the other side of the collet and is movable back and forth in the axial direction of the spindle. An engaging member (8) having a tapered engaging portion (8a) for engaging with the outer peripheral surface on one end side, and the engaging member (8) through which the engaging member is brought into contact with the collet. A biasing means (9) for constantly biasing the collet to one side, and when the draw bar is moved to one side by the tool unclamping device, a biasing force of the engaging member to one side by the biasing means. Temporarily use the tool holder with Temporary holding device of the tool holder in the spindle of a machine tool, characterized in that to lifting. 2. The temporary holding device for a tool holder according to claim 1, wherein in the tool unclamping device (12), the draw bar urging means pulls and clamps the tool holder to the other side via the draw bar. Tool clamp position that does not hinder the tool holder, a temporary holding position that releases the pull of the tool holder by the draw bar to temporarily hold the tool holder, and a pull bar that forces the pull stud to move to one side. A temporary holding device for a tool holder on a spindle of a machine tool, wherein the draw bar pressing member can be moved between three positions of a tool unclamp position. 3. The tool unclamping device (29) comprises:
A first piston (31a) and a second piston (31b) fitted in a cylinder body (30) so as to be movable back and forth.
And a first cylinder chamber (30a), a second cylinder chamber (30b) and a third cylinder chamber (30c) which are formed by partitioning the inside of the cylinder body by these two pistons.
And a pressure fluid inlet / outlet provided in each of the first to third cylinder chambers, through which a pressure fluid for pressing and moving each piston moves in and out, and each piston when the piston moves a predetermined stroke. , A drawbar pressing member (32) that moves forward and backward in a stepwise manner as each piston moves by the predetermined stroke, and a pressure fluid generation that generates a pressure fluid of a predetermined pressure to be supplied to each cylinder chamber. A device (41) and a pressure fluid switching valve (40) for distributing the pressure fluid generated by the pressure fluid generation device to a predetermined cylinder chamber.
In each of the cylinder chambers, when the pressure receiving area of the portion to which the piston is applied with the pressure fluid is A ₁ , A ₂ , A ₃ , A _{4 in} order from one side, the pressure receiving is The area has a relationship of A ₁ <A ₂ <A ₃ <A ₄ , and the switching valve supplies pressure fluid to the third cylinder chamber by switching ports while constantly supplying pressure fluid to the first cylinder chamber. The operation of discharging the discharge fluid from the second cylinder chamber while supplying, the operation of discharging the discharge fluid from both the second and third cylinder chambers, and the operation of supplying the pressure fluid to both the second and third cylinder chambers. The tool holder temporary holding device according to claim 2, wherein: 4. An engaged portion (2a) which is formed on the inner peripheral surface of the collet (2) and which is engageable with the engaging convex portion at one end of the opening / closing member (4). 4a) is formed, and when the draw bar moves from the temporary holding position to the tool unclamp position, the engaging convex portion and the engaged portion are engaged with each other so that the collet moves together with the movement of the draw bar. The temporary holding device for a tool holder on a spindle of a machine tool according to claim 1 or 2, wherein the temporary holding device is capable of moving to one side. 5. The collet (2 ′) has a protrusion (2a ′) on the inner peripheral surface thereof, which is capable of contacting the tip of the opening / closing member (4) and the pull stud (Ta), and a tool. The collet can be moved to the one side position without interfering with the drawbar (5) waiting at the neutral position in the collet (2 ') during the pulling-out operation of the holder (T). A temporary holding device for a tool holder on a spindle of a machine tool according to claim 1 or 2.