JPH05269611A - Attachment/detachment device for tool - Google Patents

Abstract

PURPOSE:To realize the facilitation and the high speed of tool exchange and increase processing precision and rigidity by making the clamping force of a tool fixed. CONSTITUTION:A relay member 2 having a male taper 9 and a flange 10 to stick closely to the flange 6 and the taper hole 12 of a main shaft 1 respectively is fixed at the main shaft 1. A male screw 11 to be screwed with a tightening nut 3, a contact end surface 13 to stick closely to the contact end surface 25 of a tool retaining member 4, a male taper 13 to be put into a taper hole 16, a motive power transmission key 19 to be engaged with a key groove, are provided at the relay member 2. At the tightening nut 3, a female screw 24 to be screwed with the male screw 11 and a push-pressing piece 23 to catch the flange 18 of the tool retaining member 4 are formed in opposition to the key groove. The tightening nut 3 is locked rotationally by means of a lock mechanism 5, and the tool retaining member 4 is tightened by making the main shaft conduct free angle rotation till predetermined torque is attained.

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a tool attaching / detaching device used for tool exchange in a machining center and various other machine tools.

[0002]

2. Description of the Related Art As a tool attaching / detaching device used in a conventional machining center or the like, a so-called pull stud type device having a built-in mechanism called a pull stud for pulling a tool into a spindle is often used. In addition, a so-called U-axis control method has recently been known in which drive control is provided with an additional shaft separate from the main shaft so that the machining radius can be adjusted while the main shaft is rotating when boring or facing is performed in a machining center or the like. Has been.

However, this type is disclosed in, for example, Japanese Patent Laid-Open No.
As disclosed in Japanese Patent Publication No. 7-132905 or Japanese Patent Publication No. 3-10467, a driving force is externally applied to a boring processing unit or a facing processing unit, which makes these units complicated. There are drawbacks. Further, it is conceivable to provide a U-axis concentrically with the main shaft, but the conventional pull stud method cannot be implemented because the pull stud is built therein.

Further, as a tool attaching / detaching device which does not use a pull stud, a quick change type device as disclosed in Japanese Patent Publication No. 3-4324 has been proposed. This method uses the rotating function of the spindle to attach and detach the tool, and has the excellent advantage that the tool rigidity can be increased because the pull stud is not used and the end face of the spindle is used.

[0005]

The conventional type with a built-in pull stud has a drawback that the inside of the spindle becomes complicated, and the U-axis control type has a complicated unit for boring and facing. It has the drawback that the origin setting function for the cutting edge position must be provided separately.

Further, the above-mentioned quick change type one has a drawback that it cannot be used as a general purpose because a male screw for screwing a tightening nut needs to be provided at the tip of the main shaft. Further, in this structure, when the tool is changed because the taper portion is long, it is necessary to move a considerable distance in order to completely pull out the tool holding member from the spindle, so that it is difficult to speed up automatic tool change.

Further, since this method is a method of rotating the main shaft by a predetermined angle to attach / detach the tool, the clamping force varies significantly depending on the type of the tool or the thickness of the flange portion of the tool holding member. However, there is a possibility that chattering or damage to the cutting edge may occur at the time of processing, which has a drawback that the processing accuracy is greatly adversely affected.

The object of the present invention is to enable easy and high-speed tool exchange, and to keep the clamping force of the tool constant,
It is an object of the present invention to provide a tool attaching / detaching device which has high processing accuracy, tool rigidity, safety, and the like, and which can accurately set the origin of the blade edge position.

[0009]

A tool attaching / detaching device according to the present invention for achieving the above object is a relay member fixed to an end portion of a spindle of a machine tool, and a tightening screwed around the relay member. A nut and a tool holding member attached to the end of the spindle by the tightening nut, and the relay member has a male taper that engages with a taper hole, a contact end surface and a key groove provided in the tool holding member. A contact end face and a rotation stop key, and the tightening nut has a clamp pawl that carries the tool holding member and presses it toward the spindle.

[0010]

In the tool attaching / detaching device having the above-mentioned structure, when the main shaft is rotated to a certain tightening torque, the tool holding member is pressed toward the main shaft side by the clamp claw of the tightening nut due to the screwing state with the tightening nut. The male taper and the contact end surface of the relay member and the taper hole and the contact end surface of the tool holding member are brought into close contact with each other at a predetermined pressure.

[0011]

DESCRIPTION OF THE PREFERRED EMBODIMENTS The present invention will be described in detail based on the illustrated embodiments. FIG. 1 shows an embodiment of a tool attaching / detaching device according to the present invention, and shows a state in which a tool holding member 4 is attached to a spindle 1 of a machine tool via a relay member 2 with a tightening nut 3. Also, in order to fix the tightening nut 3 in the rotation direction,
Locking means 5 is provided on the machine tool side fixed portion. A flange 6 is provided at the lower end of the main shaft 1, and a taper hole 8 is formed at the inlet of the cylindrical hole 7 in the axial direction. The relay member 2 fixed to the lower end of the main shaft 1 has the tapered hole 8
Has a male taper 9 that engages with the flange 6 and a flange 10 that is in close contact with the end surface of the flange 6, and further, following the flange 10, a male screw 11 that engages with the tightening nut 3 and a male taper 12 that engages with the tool holding member 4. have.

As shown in FIGS. 2 and 3, the contact end surface 13 of the base of the male taper 12 of the relay member 2 is in close contact with the tool holding member 4, and the contact end surface 13 has, for example, three rotation stoppers as shown in the drawing. The key 14 is provided at an equal angle to the axis.

In FIG. 1, the rotation stop key 14 is a screw 1
It is attached to the relay member 2 by 5. The tool holding member 4 has at its upper end a first flange 18 having a tapered hole 16 that engages with the male taper 12 of the relay member 2 and a contact end surface 17 that closely contacts the contact end surface 13 of the relay member 2. A quick change structure is formed between the tightening nut 3 and the tightening nut 3.

As shown in FIGS. 4 and 5, the tool holding member 4
Around the first flange 18 and the above-described anti-rotation key 14
A key groove 19 that engages with and transmits a rotational force is provided, and an outer peripheral surface of a second flange 20 that is formed at a predetermined distance from the first flange 18 is used for automatic tool replacement at the time of AT change.
A V-shaped grip portion 21 to be gripped by the arm of the C manipulator is formed, and further the first flange 18 and the second flange 18 are formed.
A clamp claw 23 of the tightening nut 3 to be described later can be inserted into the groove 22 between the flange 20 and the groove 20.

As shown in FIGS. 6 and 7, the tightening nut 3 has a substantially annular shape, and a female screw 24 to be screwed with the male screw 11 of the relay member is provided on the upper inside thereof to form the female screw 24.
The inner diameter 25 of the lower surface of the tool holding member 4 is slightly larger than the outer diameter of the first flange 18 of the tool holding member 4.
Clamp claws 23 projecting toward the center at equal positions are formed corresponding to the key grooves 19. In addition, on the outer peripheral surface of the tightening nut 3, a locking recess 2 corresponding to the locking means 5 is formed.
6 is provided.

In the case of the present embodiment, the structure of the tip end side of the tool holding member 4, that is, the tool mounting side is a roll lock chuck system suitable for gripping an end mill or the like.
Of course, other types can be applied depending on the type of the tool holding member. In the illustrated case, a holding cylinder 27 into which the tool T is directly or indirectly inserted, a tightening cylinder 28 rotatably mounted on the outer peripheral surface of the holding cylinder 27 at a predetermined interval, and a needle roller 29 interposed therebetween. The rotation of the tightening cylinder 28 causes the needle roller 29 to rotate and spirally revolve, and to contract and restore the holding cylinder 27.

The ordinary relay member 2 is provided with a screw or the like for the main shaft 1.
Is fixed to the front end of the relay member 2, and the tightening nut 3 is also screwed into the relay member 2. FIG. 1 shows a state in which the main shaft 1 is stopped after processing is completed. From this state, the V-shaped grip portion 21 is first gripped by an ATC manipulator (not shown), and then the locking means 5 is driven to tighten the tightening nut 3. Lock in the direction of rotation. When the spindle 1 is rotated by a certain angle in this state, the key groove 19 of the tool holding member 4 and the clamp claw 23 of the tightening nut 3 are aligned with each other. ATC here
When the manipulator is operated, the tool holding member 4 can be removed from the spindle 1.

On the contrary, when the tool holding member 4 is mounted on the spindle 1, the above-mentioned removal may be performed in reverse. That is, when the key groove 19 of the tool holding member 4 and the clamp claw 23 of the tightening nut 3 are inserted at a matched position, the taper hole 16 of the tool holding member 4 first engages with the male taper 12 of the relay member 2. , Both have a key groove 19 that prevents the key 14 from turning.
Is positioned in the central position by being engaged with and is locked in the rotational direction. Therefore, when the main spindle 1 is rotated with a predetermined tightening torque, the clamp claw 23 of the tightening nut 3 causes the first flange 18 of the tool holding member 4 to be screwed by the screwing state with the tightening nut 3.
Is pressed to the main shaft 1 side, the contact end surface 13 of the relay member 2, the contact end surface 17 of the tool holding member 4, the male taper 12 and the tapered hole 16 are brought into close contact with each other with a predetermined pressure, and both are firmly integrated. In FIG. 5, H is a moving distance at the time of exchanging the tool, which can be significantly shortened as compared with the conventional example, so that the tool can be exchanged at a higher speed.

In the present invention, in order to rotate the spindle 1 by an arbitrary angle until the flange end surface of the tool holding member 4 is pressed to the spindle 1 side with a predetermined torque, the following detecting means and control means are provided. It is necessary to provide.

(1) In order to detect the phase difference between the tightening nut 3 and the spindle 1 side, the spindle 1 and the tightening nut 3 are respectively provided with position detectors.

(2) Since the position of the tightening nut 3 is determined by this position detector, the position of the spindle 1 side is confirmed at the same time, and the phase difference angle between the tightening nut 3 and the spindle 1, that is, the position error is calculated. Provide means.

(3) Tool tightening requires means for detecting tightening torque, tightening position, and tightening speed, and input means capable of changing these numerical values, and a tool with a predetermined clamping force. Control means will be provided to confirm the tightening.

(4) When the tool is clamped, the spindle 1 is rotated by the angle calculated in the above (2), and the control means is provided for positioning the anti-rotation key 14 and the clamp claw 23 to the detachable position.

Next, the operation of automatic tool change will be described with reference to FIG. FIG. 8A shows a state in which the tool is attached, and in this state, the detent key 14 and the locking recess 26 of the tightening nut 3 are apart from each other by a certain angle with respect to the axis. Since this angle is tightened with a constant torque when clamping,
It differs for each tool holding member 4 due to an error in the thickness dimension of the first flange 18 of the tool holding member 4.

(A) In this state, the spindle 1 rotates to perform machining, and when the machining is completed, the spindle 1 stops.

(B) Next, a tool change command is output from the NC device.

(C) Therefore, the spindle 1 is positioned at a specified position by using the position information of the tightening nut 3 by the position detector. This position is shown in Fig. 8 (b).
This is the position where the locking recess 26 and the lock pin of the lock means 5 can be engaged. For this stop, the position detector of the main shaft 1 passes through the first flange 18, and the angular error between the rotation stop key 14 and the locking recess 26 of the tightening nut 3 is calculated by the control means. This is the clamp angle of the tool.

(D) When the positioning of the tightening nut 3 is completed, the lock pin of the lock means 5 advances and the tightening nut 3
The tightening nut 3 is fitted in the locking recess 26 of FIG.

(E) Then, the arm of the ATC manipulator rotates to grip the V-shaped grip portion 21 of the tool holding member 4.

(F) Next, the main shaft 1 is rotated in the direction in which the screw of the tightening nut 3 is loosened, that is, in the direction of arrow A in FIG. 8 (c) by the angle calculated in the above step (c) to position it. The locking key 14 and the locking recess 26 of the tightening nut 3 are locked.
Match the positions of and. As a result, the position of the clamp claw 23 of the tightening nut 3 and the position of the key groove 19 of the tool holding member 4 match.

(G) When the arm of the ATC manipulator is lowered, the tool holding member 4 is taken out from the spindle 1. Next, with the arm of the ATC manipulator,
Another tool holding member 4 is transferred below the spindle 1.

(H) Then, a new tool holding member 4 is attached by raising the arm of the ATC manipulator. In this case, since the anti-rotation key 14 and the locking recess 26 are in a matched state, the tool holding member 4 can be easily inserted.

(B) Next, the spindle 1 is moved to the position shown in FIG. 8 until a predetermined force is obtained according to the torque and speed set by the input means.
Rotate in the direction of arrow B in (d). As a result, the tightening nut 3
The clamp claw 23 of the first flange 1 of the tool holding member 4.
8 is pressed to the relay member 2 side, and the tool holding member 4 is fixed to the spindle 1.

At this time, the torque detecting means, the position detecting means, and the speed detecting means detect the spindle output torque, the spindle position, and the spindle rotation speed, respectively, at the time of tightening, and the values are set by the input means. After confirming that, the clamping operation of the tool holding member 4 is completed.

During the mounting operation of the tool holding member 4, the key groove 19 of the tool holding member 4 is engaged with the anti-rotation key 14 of the relay member 2 to be connected in the rotational direction. Since there is a gap between the key grooves 19, the tool holding member 4 is pressed against one side of the end face of the key within the range of the gap by the rotation operation of the spindle in the next operation. In this state, the main shaft 1 rotates a certain angle until it reaches a predetermined torque, so that the key 1 is tightened while being pressed against the end surface.

This means that the tool holding member 4 and the spindle 1 are always
Since it is possible to maintain the phases of and at a fixed position, it is possible to use them for setting the origin of the blade tip position of the tool T. By the way, in the tool attaching / detaching device disclosed in the above-mentioned Japanese Patent Publication No. 3-4324 cited as a conventional example, since the main shaft is always rotated by a constant angle, the key may be varied due to the variation in the tightened state. There is a possibility that the position of the key in the groove may be displaced, which makes the setting of the origin of the cutting edge position unstable.

Furthermore, Japanese Patent Publication No.
In the U-axis control method disclosed in Japanese Patent Laid-Open No. 10467, it is necessary to separately provide an origin setting function for the cutting edge position, but in the case of the present invention, there is no such need, and a machine tool such as a machining center has it. It is possible to easily set the origin of the cutting edge position by using the orientation function provided.

In the embodiments shown in FIGS. 1 to 7, the main shaft 1 and the relay member 2 are separate and fixed by screws or the like. However, the relay member 2 and the main shaft 1 are integrally formed. It is also possible to do so. FIG. 9 shows an embodiment thereof, and in this case, the flange 1 corresponding to the flange 10, the male screw 11, the male taper 12, the contact end face 13 and the rotation preventing key 14 of the relay member 2 shown in FIG.
0 ', a male screw 11', a male taper 12 ', a contact surface 13' and a rotation stop key 14 'may be provided, and the other tightening nut 3, tool holding member 4 and locking means 5 are the same as those in FIG. The same can be used.

As still another embodiment, as shown in FIG. 10, when a tool is replaced, a pressure fluid such as air is blown into the tightening nut 3 through the locking means 5 so that the taper coupling surface and the close contact of the relay member 2 are closely contacted. It is also possible to clean the end faces.

As a concrete structure, the tightening nut 3 has a double structure consisting of an outer member 3a and an inner member 3b, and an annular groove 31 is formed between them to form a locking groove 26 corresponding to the locking recess 26. 'To the annular groove 31
And a plurality of flow paths 32b penetrating inward from the annular groove 31.
Is provided, and for example, air is sent to the annular groove 31 from the passage 33 passing through the inside of the locking means 5 through the passage 32a, and further from the annular groove 31 through the passage 32b, the contact end surface 13 of the relay member 2 and the male taper. It suffices that air is blown onto 12.

As a result, every time the tool is replaced, the contact end surface 1
3 and the male taper 12 and the like to remove dust, chips, and the like to complete close contact with the tool holding member 4, and as a result, it is possible to improve the machining accuracy.

[0042]

As described above, in the tool attaching / detaching device according to the present invention, since the tool clamping force can be made constant, the machining accuracy can be improved, and the tool holding member can be contacted with the reverse taper and the end face contact at the end of the spindle. Since they are joined together, the tool rigidity is remarkably improved, and the safety and reliability are also increased. Moreover,
Since the moving distance for tool change can be reduced, tool change can be performed easily and at high speed. Further, since the phase between the spindle and the tool holding member can always be kept at a fixed position, the origin of the cutting edge position can be set accurately. Further, by using the relay member, it can be applied to a general-purpose machine tool, and can be effectively used for incorporating a U-axis drive device inside the main spindle. Further, it is not necessary to machine a precision screw on the spindle, and it is possible to easily change to the quick change system simply by tapping a general-purpose spindle.

[Brief description of drawings]

FIG. 1 is a sectional view of a first embodiment.

FIG. 2 is a side view of a relay member.

FIG. 3 is a bottom view thereof.

FIG. 4 is a plan view and a side view of a tool holding member.

FIG. 5 is a side view thereof.

FIG. 6 is a sectional view and a bottom view of the tightening nut.

FIG. 7 is a bottom view thereof.

FIG. 8 is an operation explanatory diagram.

FIG. 9 is a cross-sectional view of the second embodiment.

FIG. 10 is a sectional view of a third embodiment.

[Explanation of symbols]

 1 Spindle 2 Relay Member 3 Tightening Nut 4 Tool Holding Member 5 Locking Means 6 Flange 10, 18, 20 Flange 11 Male Screw 12 Male Taper 13, 17 Contact End Face 14 Non-rotating Key 19 Key Groove 23 Clamp Claw 24 Female Thread Part

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[Procedure amendment]

[Submission date] June 3, 1993

[Procedure Amendment 1]

[Document name to be amended] Statement

[Name of item to be corrected] Full text

[Correction method] Change

[Correction content]

[Document name] Statement

[Title of the Invention] Tool attaching / detaching device

[Claims]

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a tool attaching / detaching device used for tool exchange in a machining center or other types of machine tools, and more specifically, a so-called nut runner for fixing a tool holder to a spindle of a machine tool with a tightening nut. System tool attaching / detaching device.

[0002]

2. Description of the Related Art Conventionally, a tool attaching / detaching device of this type is disclosed in Japanese Patent Publication No. 3-4324. As shown in FIG. 11, a main shaft 2 is rotatably inserted and arranged in a main shaft device 1. A tool holder 4 is detachably attached to the lower end of the spindle 2 by a tool attaching / detaching device 3. The tool attaching / detaching device 3 includes a tightening nut 5 threadably mounted on the lower end of the main shaft 2, and a lock mechanism 6 that locks the tightening nut 5 in the rotational direction. The tightening nut 5 has a cylindrical shape, and a lock hole 5a is provided in the middle of the outer peripheral surface thereof.
A plurality of pressing pieces 5b are provided on the lower end of the inner peripheral surface so as to protrude inward.

The lock mechanism 6 comprises a cylinder 7 and a hydraulic pressure supply system 8 for connecting the cylinder 7 to a hydraulic pressure source. A piston rod 9 inserted into the cylinder 7 is advanced to advance the tightening nut 5. Fit into the lock hole 5a of
Thereby, the tightening nut 5 is configured to be locked in the rotation direction. A position sensor 10 for detecting the angular position of the nut 5 is provided outside the tightening nut 5.

A cutting tool T is attached to the tool holder 4. A power transmission key 11 in which a plurality of key grooves 4b are attached to the lower end of the spindle 2 on the flange portion 4a of the tool holder 4
It is formed so that it can be fitted. Further, the pressing piece 5b of the tightening nut 5 presses the flange portion 4a.

Further, on the outer peripheral surface of the tool holder 4, a grip groove 4c to be gripped by an exchange arm (not shown) is formed in an annular shape.

[0006]

The conventional nut runner type has a drawback that it cannot be used as a general purpose because it is necessary to provide a male screw 2a for screwing the tightening nut 5 on the tip of the main shaft 2. .. Further, in this structure, the taper portion 2b is long, the female taper is provided on the main spindle 2 side, and the male taper is provided on the tool holder 4 side. Therefore, when the tool is replaced, the tool holder 4 is completely pulled out from the main spindle 2. Needs to move the tool holding member a considerable distance,
It is difficult to speed up automatic tool change.

Moreover, since this system employs a structure in which the main shaft 2 is rotated by a predetermined angle, the tightening nut 5
The thickness of the flange part 4a of the tool holder 4 clamped at is not exactly the same for each tool holder 4, and the screw part wears during long-term use, resulting in significant variations in the clamping force. As a result, there is a risk that chattering or damage to the cutting edge may occur during processing, which has a disadvantage that processing accuracy is also adversely affected.

The object of the present invention is to shorten the time required for the tool exchanging operation, to keep the clamping force of the tool constant, to improve the machining accuracy, the rigidity of the tool, the safety, etc., and to clean the contact end face of the spindle and the tool holder. It is to provide a tool attaching / detaching device.

[0009]

A tool attaching / detaching device according to a first aspect of the present invention for achieving the above object is a relay member fixed to an end of a spindle of a machine tool, and is screwed around the relay member. The relay member comprises a nut and a tool holding member mounted on the end of the spindle by the nut, and the relay member has a contact end surface and a power transmission key that engage with a contact end surface and a key groove provided on the tool holding member, respectively. The nut includes a pressing piece that carries the tool holding member and presses the tool holding member toward the spindle.

A tool attaching / detaching device according to a second aspect of the present invention comprises a nut screwed around a spindle end of a machine tool, and a tool holding member mounted on the spindle end by the nut. The end portion is provided with a taper hole provided in the tool holding member, a male taper that engages with the contact end surface and the key groove, a contact end surface and a power transmission key, and the nut carries the tool holding member and the main shaft. It is characterized in that a pressing piece for pressing to the side is provided.

Further, a tool attaching / detaching device according to a third aspect of the present invention comprises a nut screwed around a spindle end of a machine tool, and a tool holding member mounted on the spindle end by the nut. The end portion is provided with a contact end surface provided on the tool holding member and a contact end surface that engages with a key groove and a power transmission key, and the nut carries the tool holding member and presses it toward the main shaft side. The tool holding member is tightened by rotating the main shaft by an arbitrary angle until a predetermined torque is obtained.

[0012]

In the tool attaching / detaching device according to the first aspect of the present invention, the contact end face of the relay member is engaged with the contact end face of the tool holding member, and the power transmission key is engaged with the key groove. When the rotation is transmitted to the tool holding member and the rotation of the nut is fixed and the spindle is rotated to a certain tightening torque,
The pressing piece of the nut presses the tool holding member toward the main shaft by the screwed state with the nut, and the contact end surface of the relay member and the contact end surface of the tool holding member are brought into close contact with each other at a predetermined pressure.

In the tool attaching / detaching device according to the second aspect of the present invention, the taper hole of the main shaft, the male taper of the tool holding member and the contact end surface are engaged with the contact end surface, and the power transmission key is engaged with the key groove. When the rotation of the main shaft is transmitted to the tool holding member and the rotation of the nut is fixed and the main shaft is rotated to a certain tightening torque, the pressing piece of the nut presses the tool holding member toward the main shaft side due to the screwing state with the nut. The contact end surface of the spindle and the contact end surface of the tool holding member are brought into close contact with each other at a predetermined pressure.

Further, in the tool attaching / detaching device according to the third aspect of the invention, the power transmission key engages the key groove to transmit the rotation of the spindle to the tool holding member, and the pressing piece of the nut holds the tool with the contact end surface of the spindle. Until the contact end face of the member is pressed with a predetermined clamping force, the rotation of the nut is fixed and the main shaft is rotated by an arbitrary angle until a predetermined torque is achieved.

[0015]

DESCRIPTION OF THE PREFERRED EMBODIMENTS The present invention will be described in detail based on the illustrated embodiments. FIG. 1 is a side view showing a cross section of a main part of the first embodiment, in which a relay member 23 is attached to a main shaft 22 of a main spindle device 21, and a tool holder 25 is fixed by a tightening nut 24 via the relay member 23. It is installed. A flange 22a is provided at the lower end of the main shaft 22, and a tapered hole 22c is formed at the inlet of the cylindrical hole 22b in the axial direction. As shown in FIGS. 2 and 3, the relay member 23 fixed to the lower end of the main shaft 22 is provided with a male taper 23a that engages with the tapered hole 22c of the main shaft 22 and a flange 23b that is in close contact with the end surface of the flange 22a. Further, following the flange 23b, a male screw 23c screwed with the tightening nut 24 and a male taper 23d engaged with the taper hole 25a of the tool holder 25.
Is provided. The base portion of the male taper 23d of the relay member 23 is a contact end surface 23e which is in close contact with the contact end surface 25b of the tool holder 25, and three power transmission keys 26 are provided at the same angle with respect to the shaft center.

As shown in FIGS. 4 and 5, the tool holder 25 is formed with a taper hole 25a which engages with the male taper 23d of the relay member 23, and the flange 25c at the periphery of the hole is in contact with the relay member 23. Contact end face 25 that closely contacts end face 23e
b and a key groove 25e that engages with the power transmission key 26 to transmit the rotational force are formed. Also, the flange 25c
A grip groove 25g that is gripped by an exchange arm (not shown) is formed in the flange 25f formed below the. The flange 25c and the flange 2 will be described later.
Between 5f, there is a pressing groove 25h into which the pressing piece 24a of the tightening nut 24 is fitted.

The inner peripheral surface of the tightening nut 24 is shown in FIGS.
As shown in FIG. 3, a pressing piece 24 a that presses the lower surface of the flange 25 c of the tool holder 25 and the male screw 23 of the relay member 23.
A female screw 24b that is screwed with c is formed. A lock hole 24c for locking the tightening nut 24 is formed on the outer peripheral surface of the tightening nut 24. A lock mechanism 28 having, for example, a piston rod 28a is provided on the outer periphery of the tightening nut 24.
By fitting and inserting a into the lock hole 24c, rotation of the tightening nut 24 is prevented.

In the case of this embodiment, the structure of the tip side of the tool holder 25, that is, the mounting side of the tool T is the roll lock chuck type suitable for gripping the end mill or the like. Of course, other types can be applied depending on the situation.

Usually, the relay member 23 is fixed to the tip of the main shaft 22 by a screw or the like (not shown), and the tightening nut 24 is screwed to the relay member 23. FIG. 1 shows a state in which the machining is completed and the spindle 22 is stopped. From this state, first, the lock mechanism 28 is driven to lock the tightening nut 24 in the rotation direction, and then the grip groove is held by an ATC manipulator (not shown). Hold 25g. When the main shaft 22 is rotated by a certain angle in this state, the key groove 25e of the tool holder 25 and the pressing piece 24a of the tightening nut 24 are aligned with each other. Here, when the ATC manipulator is operated, the tool holder 25 can be removed from the spindle 22.

On the contrary, when the tool holder 25 is mounted on the main shaft 22, the above-mentioned removal may be performed in reverse.
That is, the key groove 25e of the tool holder 25 and the tightening nut 24
By inserting at the position where the pressing piece 24a of
First, the taper hole 25a of the tool holder 25 is engaged with the male taper 23d of the relay member 23, and the key groove 25e is engaged with the power transmission key 26 to be positioned at the central position and locked in the rotational direction. Therefore, when the main shaft 22 is rotated with a predetermined tightening torque, the pressing piece 24a of the tightening nut 24 presses the flange 25c of the tool holder 25 toward the main shaft 22 side due to the screwing state with the tightening nut 24, and the relay member 23 The contact end surface 23e, the contact end surface 25b of the tool holder 25, the male taper 23d, and the tapered hole 25a are brought into close contact with each other at a predetermined pressure, and both are firmly integrated. In addition, in FIG.
Since the moving distance H at the time of tool exchange can be significantly shortened as compared with the conventional example, it is possible to further speed up the tool exchange.

In the present invention, the following detecting means and control means are provided in order to rotate the spindle 22 by an arbitrary angle until the tool holder 25 is pressed against the spindle 22 by a predetermined force. is necessary.

(1) In order to detect the phase difference between the tightening nut 24 and the main shaft 22, a position detector is provided on each of the main shaft 22 and the tightening nut 24.

(2) With this position detector, the tightening nut 24
Positioning of the spindle 22 at the same time,
A control means for calculating a phase difference angle between the tightening nut 24 and the main shaft 22, that is, a position error is provided.

(3) Tool tightening requires means for detecting tightening torque, tightening position, and tightening speed, and input means capable of changing these numerical values and a tool with a predetermined clamping force. Control means will be provided to confirm the tightening.

(4) When the tool is unclamped, the main shaft 22 is rotated by the angle calculated in (2) above and the keyway 2
A control means for positioning the 5e and the pressing piece 24a at a position where they can be attached and detached is provided.

Next, the operation of automatic tool change will be described with reference to FIG. FIG. 8A shows a state in which the tool is attached, and in this state, the power transmission key 26 and the lock hole 24c of the tightening nut 24 are at a position separated from the axis by a certain angle. Since this angle is tightened with a constant torque when clamping,
It differs for each tool holder 25 due to an error in the thickness dimension of the flange 25c of the tool holder 25.

(A) In this state, the spindle 22 rotates to perform the machining, and when the machining is completed, the spindle 22 stops.

(B) Next, a tool change command is output from the NC device.

(C) Therefore, the spindle 22 is positioned at the previous tool clamp position according to the position information of the tightening nut 24 by the position detector. As shown in FIG. 8 (b), this position corresponds to the lock hole 24c of the tightening nut 24 and the lock mechanism 28.
And are positions where they can be engaged. For this stop, the position detector of the main shaft 22 calculates an angular error α between the power transmission key 26 and the lock hole 24c of the tightening nut 24 by the control means.

(D) When the positioning of the tightening nut 24 is completed, the lock mechanism 28 advances and fits into the lock hole 24c of the tightening nut 24, and the tightening nut 24 is fixed to the main shaft 22 in the rotational direction. It

(E) Then, the arm of the ATC manipulator rotates to grip the grip groove 25g of the tool holder 25.

(F) Next, in the direction in which the screw of the tightening nut 24 loosens the main shaft 22, that is, in the direction of arrow A in FIG.
The position of the power transmission key 26 and the position of the pressing piece 24a of the tightening nut 24 are matched with each other by performing the positioning by rotating by the angle α calculated in the step. As a result, the position of the pressing piece 24a of the tightening nut 24 and the position of the key groove 25e of the tool holder 25 match.

(G) When the arm of the ATC manipulator is lowered, the tool holder 25 is taken out from the spindle 22. Next, another tool holder 25 is transferred below the spindle 22 by the arm of the ATC manipulator.

(H) Then, a new tool holder 25 is mounted by raising the arm of the ATC manipulator. In this case, the power transmission key 26 and the pressing piece 24a
The tool holder 25 can be easily inserted because the condition is matched with.

(B) Next, the main shaft 22 is rotated in the direction of arrow B in FIG. 8 (d) until a predetermined force is achieved according to the torque and speed set by the input means. As a result, the pressing piece 24a of the tightening nut 24 is moved to the flange 25c of the tool holder 25.
Is pressed toward the relay member 23, and the tool holder 25
Fixed to.

At this time, the above-mentioned torque detection means, position detection means and speed detection means respectively detect the spindle output torque, the spindle position and the spindle rotation speed during tightening, and the values are set by the input means. After confirming that, the clamping operation of the tool holder 25 is completed.

During the mounting operation of the tool holder 25, the power transmission key 26 is provided with the key groove 25e of the tool holder 25.
The power transmission key 26.
Since there is a gap between the key groove 25e and the key groove 25e, the tool holder 25 will be pressed against one side of the end face of the key within the range of the gap by the next rotation operation of the spindle. Spindle 2 in this state
Since 2 rotates a certain angle until the torque reaches a predetermined torque, the key end face is clamped while being pressed.

This means that the tool holder 25 and the spindle 2 are always
Since the phase with 2 can be held at a fixed position, it can be used for setting the reference position of the blade tip position of the tool holder 25 in the main spindle rotation direction. Incidentally, in the tool attaching / detaching device disclosed in the above-mentioned Japanese Patent Publication No. 3-4324 cited as a conventional example, since the spindle rotation is always rotated by a constant angle, due to the variation in the tightened state,
There is a risk that the rotational direction position of the tool holder 4 with respect to the power transmission key 11 may be displaced, and therefore the origin setting for positioning the blade edge position has become unstable.

FIG. 9 is a sectional view of the second embodiment.
In the first embodiment shown in FIGS. 7A to 7C, the case where the main shaft 22 and the relay member 23 are separated and both are fixed by screws or the like has been shown, but here, the relay member 23 is integrally formed with the main shaft 22. There is. In this case, the main shaft 22 'has a tip end as shown in FIG.
23b of the relay member 23 shown in FIG.
c, male taper 23d, contact end surface 23e and flange 23b 'corresponding to power transmission key 26, male screw 23c', male taper 23d ', contact surface 23e' and power transmission key 2
6'may be provided, and the other tightening nut 24, tool holder 25, lock mechanism 28 and the like may be the same as those in the case of FIG.

FIG. 10 is a cross-sectional view of the third embodiment, in which a fluid such as air is blown into the tightening nut 31 through the lock mechanism 30 when the tool is replaced, so that the taper coupling surface of the relay member 23 and the close contact thereof are closely attached. I try to clean the end faces.

As a concrete structure, the tightening nut 31 has a double structure consisting of an outer member 31a and an inner member 31b, and an annular groove 31c is formed between them, and a flow path from the lock hole 31d to the annular groove 31c is formed. 32a and a plurality of flow paths 32b penetrating inward from the annular groove 31c are provided, and for example, air is sent to the annular groove 31c from the flow path 30a passing through the inside of the lock mechanism 30 through the flow path 32a, and further the annular groove Air may be blown to the male taper 23d and the contact end surface 23e of the relay member 23 from 31c through the flow path 32b.

As a result, the male taper 2 is changed every time the tool is changed.
It is possible to remove dust, chips and the like adhering to 3d and the contact end surface 23e and the like to complete the close contact with the tool holder 25, and as a result, the machining accuracy can be improved.

[0043]

As described above, the tool attaching / detaching device according to the first invention can be applied to a general-purpose machine tool by using the relay member, and it is not necessary to machine a precise screw on the main shaft. The nut runner system can be easily changed by tapping the general-purpose spindle.

In the tool attaching / detaching device according to the second aspect of the present invention, since the tool holding member is connected by the reverse taper and the end face contact at the end of the spindle, the tool rigidity is remarkably improved and the safety and reliability are also improved. Moreover, since the moving distance for tool replacement can be reduced, tool replacement can be performed easily and at high speed.

In the tool attaching / detaching device according to the third aspect of the present invention, after fixing the nut, the main shaft is rotated by an arbitrary angle until a predetermined torque is obtained. Therefore, the tool holding member has an error in the thickness of the flange portion clamped by the nut. Even if there is any damage or the nut and the threaded portion of the main shaft are worn, a sufficient tightening force can be obtained.

Further, since the tool clamping force can be made constant, the machining accuracy can be improved, and the phase between the spindle and the tool holding member can always be kept at a fixed position, so that the spindle rotational direction reference position of the cutting edge position can be set accurately. It can be carried out.

[Brief description of drawings]

FIG. 1 is a sectional view of a main part of a first embodiment.

FIG. 2 is a side view of a relay member.

FIG. 3 is a bottom view thereof.

FIG. 4 is a plan view of a tool holder.

FIG. 5 is a side view thereof.

FIG. 6 is a cross-sectional view of a tightening nut.

FIG. 7 is a bottom view thereof.

FIG. 8 is an operation explanatory diagram.

FIG. 9 is a partial cross-sectional view of the second embodiment.

FIG. 10 is a sectional view of a third embodiment.

FIG. 11 is a cross-sectional view of a main part of a conventional example.

[Explanation of reference numerals] 22 spindles 22a, 23b, 25c, 25f flange 23 relay member 23c male screw 23d male taper 23e, 25b contact end face 24 tightening nut 24a pressing piece 24b female screw 24c lock hole 25 tool holder 25e key groove 26 power transmission key 28 Lock mechanism

[Procedure 3]

[Document name to be corrected] Drawing

[Correction target item name] All drawings

[Correction method] Change

[Correction content]

[Figure 1]

[Fig. 2]

[Figure 3]

[Figure 4]

[Figure 6]

[Figure 7]

[Figure 5]

[Figure 8]

[Figure 9]

[Figure 10]

FIG. 11

Front page continuation (72) Inventor Yasuhiro Kutomi 132 Chisenshinden, Futtsu-shi, Chiba Kuroda Seiko Co., Ltd.Futtsu factory (72) Inventor Yoshinori Yamaguchi 106 Kita-Koriyama-cho, Yamatokoriyama-shi, Nara Mori Seiki Co., Ltd. (72) Inventor Shu Yoneya 106 Mori Seiki Co., Ltd., Kita-Koriyama-cho, Yamato-Koriyama-shi, Nara (72) Inventor Kiyoyuki Fukushima 106 Kita-Koriyama-Cho, Yamato-Koriyama, Nara (Mori Seiki Co., Ltd.) (72) Inventor Yoshimasa Sakamoto 106 Kita-Koriyama-cho, Yamato-Koriyama-shi, Nara Inside Mori Seiki Co., Ltd. (72) Inventor Toru Yagami 106 106 Kita-Koriyama-cho, Yamato-Koriyama-shi Nara (72) Inventor Kamei Toshihide 106 Kita-Koriyama-cho, Yamato-Koriyama-shi, Nara Inside Mori Seiki Co., Ltd.

Claims (8)

[Claims] 1. A relay member fixed to a spindle end of a machine tool, a tightening nut screwed around the relay member, and a tool holding member mounted on the spindle end by the tightening nut. , The relay member is provided with a taper hole provided in the tool holding member, a male taper that engages with the contact end surface and the key groove, a contact end surface and a rotation stop key, respectively, and the tightening nut carries the tool holding member. Then, the tool attaching / detaching device is provided with a clamp claw that presses the main shaft side. 2. The tool attaching / detaching device according to claim 1, further comprising lock means for fixing the tightening nut in a rotational direction on a fixed side of the machine tool. 3. The tool attaching / detaching device according to claim 1, wherein the relay member is provided integrally with a spindle of the machine tool. 4. The tool attaching / detaching device according to claim 1, wherein a tool holding member replacement flange is provided on an outer periphery of the tool holding member. 5. The tool holding member is tightened by rotating the main spindle by an arbitrary angle until the contact end surface of the tool holding member is pressed to the main spindle side with a predetermined torque.
The tool attaching / detaching device described in. 6. The tool attaching / detaching device according to claim 1, wherein the tightening nut is an inner and outer nut, and a fluid passage is provided. 7. The tool attaching / detaching device according to claim 2, wherein the main shaft of the machine tool is rotated to attach / detach the tool holding member while the tightening nut is clamped in the rotational direction by the locking means. 8. The tool attaching / detaching device according to claim 2, wherein the lock means is provided with a fluid passage.