JPS632638A - Tool mounting/demounting device - Google Patents

Abstract

PURPOSE:To enable smooth replacement of a tool by mounting both a subcylinder which presses a piston against a disc by the force weaker than the load of a clamping disk spring and a main cylinder which presses the piston against the disc by the force stronger than said spring load. CONSTITUTION:A small-diameter sub cylinder 41 and a large-diameter main cylinder 42, which are separated wetertightly, are mounded inside a cylinder case 21 coaxially. The driving force of the sub cylinder 41 is set weaker than the load of the spring of a clamping disk spring 18, stronger than the load of a clearance-maintaining disk spring 23, and can move the cylinder case 21. The friction force is generated by contacting both a piston 31 and a disk 16 with each other so that a main shaft 13 may be interrupted by the external force which turns the main shaft 13 by the effect of the friction between the change arm of an automatic tool replacement unit and a tool. The main cylinder 42 operates on the working oil supplied from a secondary oil supply port 42A to move the piston 31 and the disk 16 against the load of the clamping disk spring 18.

Description

DETAILED DESCRIPTION OF THE INVENTION [Field of Industrial Application] The present invention relates to an improvement of a tool attachment/detachment device for detachably fixing a tool to a spindle, and can be used in machine tools such as machining centers.

C. Background technology and its problems] Multi-functional machine tools such as machining centers, which have become widely used in recent years, are equipped with an automatic tool changer and a tool attachment/detachment device that is linked to the automatic tool changer. Automated tool replacement. - In general, such tools for automatic exchange are equipped with a tapered shank for mounting, and are also provided with a keyway that corresponds to the key on the main shaft to prevent rotation, and when changing the tool, these keys and keyway In order to mesh smoothly, it is necessary to stop the main shaft at a certain rotation angle position (orientation stop) and maintain that angular position.

Conventionally, the holding force of the spindle motor when it is stopped has been used to hold the spindle orientation stop, but since the holding force is not sufficient, automatic tool change IA has been used.
When the change arm in Wa position comes into contact with a tool, the main shaft may be rotated due to friction or the like. In particular, in high-speed spindle drive systems, the speed of the spindle relative to the motor shaft is increased through gears, etc., and when an external force acts on the spindle, even if the external force is small, the gears etc. are used to boost the speed. is transmitted to the motor as a large rotational force, and the motor easily rotates. In other words, the orientation stop was held by the holding force of the spindle motor.
When using the automatic tool changer 11a, there is a problem in that the main spindle is easily rotated by a change arm or the like, and the phase angle between the key of the main spindle and the keyway of the tool becomes out of order, making it difficult to change the tool.

To solve this problem, a shot pin that protrudes and locks the spindle when stopped is used to achieve a reliable orientation stop, but this method requires a mechanism to guide the shot bottle around the spindle, a special drive J device, etc. There was a problem in that the structure was complicated, such as the need to provide a spacer, which made it unsuitable for machine tools where it was desirable to make the area around the spindle compact.

[Purpose of the invention]

An object of the present invention is to provide a tool attachment/detachment device that has a simple structure and can reliably maintain the position of the spindle.

[Means and effects for solving the problems] The present invention has the following features:
When unclamping a tool clamped to the spindle, the actuating member that is involved in the spindle also serves as a pre-unclamping operation to fix the spindle prior to the unclamping operation.

For this reason, the present invention provides a collet chuck as a tool attachment/detachment device, which is provided at the tip of a main shaft rotatably supported by a frame via a bearing, and is capable of clamping and unclamping a tool by moving in the axial direction; a main shaft side operating member that is provided near the end so as to be movable in the axial direction and that can operate integrally with the collet chuck via a drawper;
a clamp biasing means provided near the other end of the spindle to urge the spindle-side operating member to clamp the tool with the collet; and a spindle-side actuator supported by the frame so as to be movable in the axial direction of the spindle. a fixed-side actuating member that can come into contact with the main shaft-side actuating member; and the fixed-side actuating member is driven in a direction opposite to the urging force direction of the urging means to press it against the main shaft-side actuating member with a force smaller than the urging force of the urging means. a driving means for fixing the main shaft; and an unclamping drive for driving the fixed-side operating member in a direction opposite to the urging direction of the urging means to press the fixed-side operating member against the main shaft-side operating member with a force greater than the urging force of the urging means. means.

In the present invention configured as described above, during the operation, the clamp biasing means biases the collet chuck via the spindle-side operating member and the drawper, and the pull stand portion of the tool attached to the tip of the spindle, etc. Securely fix it with a collet chuck. - On the other hand, when changing tools, the main spindle is fixed by pressing the fixed side operating member against the main spindle side operating member using the spindle fixing drive means, the tool is held by a specified automatic tool changer, and then the tool is unclamped. The fixed side operating member is further pressed into contact with the main shaft side operating member by the driving means, and the main shaft side operating member, the drawer, and the collet chuck are moved by the clamp biasing means to unclamp the tool, and the automatic tool changer is Replace the tool. The present invention thus achieves the above-mentioned object by realizing reliable holding of the orientation stop 7 when changing tools.

〔Example〕

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

The tool attachment/detachment device of this embodiment is installed at the end of a main spindle that is equipped with a collet chuck that can clamp a tool pull stand at the tip. An automatic tool changer having an arm is provided.

In FIG. 1 showing details of the tool attachment/detachment device, the frame l
At the center of the main shaft 13, which is rotatably supported by the main shaft 13 via a bearing 12, is a drawbar which is movable in the axial direction and whose tip is connected to the collet chuck so that it can operate as an integral part.
A vent passage 15 for supplying compressed air for cleaning the main shaft 13 and the tapered surface of the tool passes through the center of the draw bar 14.

At the end of the main shaft 13, there is a main shaft side structure 1 that is movable in the axial direction.
A disc 16 which is a member is provided, and this disc 16 is fixed near the end of the drawbar 14 and can operate integrally with the collet chuck, and is connected to the main shaft 13 by a first rotation stopper pin 17. It is configured to rotate as a unit. Furthermore, the frame 11 on the terminal side of the main shaft 13
A first contact portion 13A is formed in the vicinity, and a clamp square disc spring 18, which is a clamp biasing means, is interposed between this contact portion 13A and the disc 16. This clamp square disc spring 18 includes a disc 16 and a drawbar 1.
4 to the right in the figure to generate a biasing force that can reliably clamp the pull stand of the tool with the collet chuck.

On the other hand, a cylinder case 21 is provided so as to surround the terminal end side of the main shaft 13, and this cylinder case 21 is slidably supported by a guide bolt 22 fixed to the frame 11, and is supported by a second cylinder case 21 at the left end in the figure. The first contact portion 21A of
It is possible to contact the contact part +3A of the guide bolt 2.
It is biased to the left in the figure by a clearance-maintaining disc spring 23 interposed between the head of
The abutting portions 13A and 21A are maintained at a predetermined clearance from each other.A piston 31, which is a fixed side operating member, is housed in a cylinder 24 formed inside a cylinder case 21. It is movable in the axial direction and can come into contact with a circle (reverse 16) on the left end surface in the figure, and the cylinder case lid 21 is movable by the second rotation stopper pin 32.
B and the frame 11 so as not to rotate.

Also, at the center of the piston 31 is a cylinder case lid 21B.
A hollow vent pipe 33 is attached to the vent pipe 33 with one end exposed to the outside and slidably penetrates the pipe. The air passage 1 is connected to the terminal end of the drawbar 14 through the attached coupler 34 and from the air supply port 33A exposed to the outside.
5, compressed air can be supplied to the tip of the spindle and the base.

On the other hand, between the cylinder case M21B on the right side in the figure of the cylinder case 21 and the piston 31, there is a small diameter sub cylinder 41 which is the first driving means and a large diameter main cylinder 42 which is the second W fJ+ means. are provided coaxially and watertightly isolated from each other, each with a cylinder case I! 2
A first oil filler port 41A and a second oil filler port that open on the outer surface of 1B
The fuel supply port 42A is connected to the fuel supply port 42A.

Here, the gf1 cylinder 41 can move the piston 31 to the left in the figure by using the hydraulic oil supplied from the first oil supply port 41A and make it come into contact with a circle (reverse 16).
The driving force of the sub-cylinder 41 is smaller than the biasing force of the clamp square disc spring 18 and larger than the biasing force of the clearance-maintaining disc spring 23 so that the cylinder case 21 can be moved. The contact is configured to generate a frictional force and stop the spindle 13 against an external force that attempts to rotate the spindle 13 due to friction between the change arm of an automatic tool changer and the tool. .

In addition, the main cylinder 42 has a wide pressurizing area, and the hydraulic oil supplied from the second oil supply port 42A moves the piston 31 and the circles 4 & 16 to the left in the figure against the biasing force of the clamp square plate spring 18. It is possible to move it to At this time, the force applied from the cylinder case 21 to the piston 31 is directly transmitted between the main shaft 13 and the disc 16 by the first and second contact parts 13A and 21A, and
3 and the frame 11 to prevent unnecessary force from being applied to the hair ring 12.

Furthermore, a clearance-maintaining cylinder 43 is provided between the outer circumferential surface of the piston 31 and the inner circumferential surface of the cylinder 24, which is formed by respective steps, and this cylinder 43 has a third cylinder 43 that opens on the outer surface of the cylinder case M21B. The piston 31 is configured to be able to move to the right in the figure by hydraulic oil supplied from the oil supply port 43A. Note that when replacing the tool, compressed air is supplied from the air supply port 33A to clean the spindle 13 and the taper surface of the tool.

In this embodiment configured in this way, as shown in FIG. 3 (A
) while holding the tool as shown in Figure 3(B).
The tool is replaced by a series of operations shown in (C).

In FIG. 3(A), the piston 31 in the cylinder case 21 is at the right end position in the figure, and the disc 16 is securely moved to the collet chuck via the drawbar 14 by the biasing force R9 of the clamp square plate spring 18. B is fixed. At this time, the cylinder case 21 is positioned on the frame 11 side, that is, on the left side in the figure, by the clearance-maintaining square plate spring 23, and a predetermined clearance is maintained between the first and second contact portions 13A and 21A. A clearance is also maintained between the circle +ff16 and the piston 31,
The main shaft 13 is rotated by a main shaft driving motor C, and a tool B is attached to the tip of the main shaft 13 with a collet chuck A.
Perform the specified work with.

- On the other hand, when replacing the tool B, the spindle 13 is stopped at the orientation stop and then the following operations are performed.

First, as a pre-unclamp operation, as shown in FIG. 3(B), a driving force F directed leftward in the figure is applied to the piston 31 by the sub-cylinder 41, and the piston 31 is moved leftward by DJ.
The cylinder case 21 is brought into contact with the circle jutan 16.
By integrating the main shaft 13 and the frame 11 via the main shaft 13, rotation of the main shaft 13 with respect to the frame 11 is prevented. At this time, the driving force F is smaller than the urging force R1 and larger than the urging force Rt, and the piston 31 is stopped from moving by the disk 16, and the reaction force of the driving force F causes the clearance-maintaining rectangular plate spring 23 is compressed to move the cylinder case 21 to the right by Dl, and the first and second abutting portions 13A and 21A are brought into contact with each other to more reliably maintain the orientation stop state.

Next, as an unclamping operation, as shown in FIG. 3(C), a driving force F2 directed leftward in the figure is applied to the piston 31 by the main cylinder 42, and the clamp square disc spring 18 is moved against the biasing force R9. By compressing and moving the disc 16 to the left by D2 and pushing the drawbar 14 to the left, the tool B attached to the main shaft I3 with the collet chuck A is removed.
Unclamp.

On the other hand, when clamping the replaced tool B to the main shaft 13, the supply of hydraulic oil to the main cylinder 42 and the sub cylinder 41 is stopped, and hydraulic oil is supplied to the clearance holding cylinder 43, so that the second Diagram (A
) to complete the replacement of the engineering RB. In this state, the tool B is clamped to the main shaft 13 by the biasing force of the disc spring 18, and a predetermined clearance is maintained between the piston 31 and the disk I6 and between the contact portions 21A and 13A. The rotation of the main shaft 13 by the main shaft driving motor C is not hindered, and machining work using a tool blade is possible.

According to this embodiment, the following effects can be obtained.

That is, in automatic tool exchange, after the orientation of the spindle 13 is stopped, the spindle 13 is fixed so as not to rotate by a pre-unclamp operation, so that the automatic tool change 1! ll! It is possible to prevent the rotation angle position of the main shaft 13 from changing due to contact with the change arm of the device, etc.
Smooth self-vJ tool exchange tA +jj operation can be performed.

Further, the orientation stop of the main shaft 13 is maintained by the pre-unclamping operation in which the disc 16 and the piston 31 are brought into contact with each other by the sub cylinder 41.
Since this is performed by the piston 31 and the piston 31, the structure can be simplified and reliable operation can be performed.

Furthermore, when the tool is unclamped by the movement of the disk 16 and the drawbar 14, the pressure of the driving force of the piston 31 applied to the circle 16 is applied to the cylinder case 21 and the first and second abutments. Since the force is directly transmitted to the main shaft 13 through the parts 13 and 21A without going through the frame 11, unreasonable force is applied to the bearings that rotationally support the main shaft 13 or to the support part between the cylinder case 21 and the frame 11. This can be prevented. In addition, as a result, the biasing force of the clamp square plate spring 18 can be increased regardless of the load capacity of the bearings, and the clamping of the tool can be made even more reliable.

Additionally, a clearance-maintaining square disc spring 23 is provided between the piston 31 and the disc 16 and between the contact portions 13A and 21A.
Since a predetermined interval is maintained by the clearance-maintaining cylinder 43, it is possible to prevent the main shaft 13 from contacting and breaking during high-speed rotation.

It should be noted that the present invention is not limited to the above-mentioned practical examples,
It also includes the following modifications.

That is, the drive means for fixing the main shaft and the drive means for unclamping are not limited to the sub cylinder 41 and the main cylinder 42 in the above embodiment, but may also be a cylinder, a solenoid, or a motor that drives the piston 31 from outside the cylinder case 21 via the piston rod. In short, the driving means for fixing the main shaft may press the fixed-side operating member against the main shaft-side operating member with a smaller force than the clamping biasing means, and the driving means for unclamping may press the fixed-side operating member against the main shaft-side operating member. Any mechanism may be used as long as it can move the main shaft-side operating member via the operating member against the clamp biasing means.

Furthermore, the fixed-side operating member is not limited to a single unit like the piston 31, but may also be provided separately with one corresponding to the main shaft fixing drive means and the other corresponding to the unclamping drive means. A cylinder may be used as the driving means, and the piston port, door, etc. protruding from the cylinder may be configured to contact the main shaft side operating member as a stationary side operating member.

However, if configured as in the embodiment described above, the structure can be made simple and compact.

Furthermore, the biasing means for clamping is not limited to the clamp square plate spring 18, but may also be a coil spring or a gas spring, but the tool can be reliably ramped, the influence of eccentricity is small even when the main shaft rotates at high speed, and the influence of temperature changes It is preferable that the influence is small, and it is desirable to use a disc spring as in the above embodiment.

In addition, the structure that makes the cylinder case 21 movable or the cleaning air path formed by the air path 15, the air pipe 33, and the coupler 34 are not particularly necessary for the present invention, and may be omitted as appropriate when implementing the invention. It is also possible to change the shape, dimensions, etc. of each part as appropriate.

(Effects of the Invention) As described above, according to the present invention, there is an effect that the tool attachment/detachment device can reliably maintain the spindle position with a simple structure.

[Brief description of the drawings] This is a clear drawing. 2, 11... Frame, 12... Bearing, 13... Main shaft, 14... Drawbar, 16...
. . . Disc which is the main shaft side operating member, 18 . . . Clamp square plate spring which is the clamp biasing means, 31 . . . Piston which is the fixed side operating member, 4I . . . Sub cylinder, 42... Main cylinder which is a drive means for unclamping.

Claims (1)

[Claims] (1) A collet chuck that is installed at the tip of a main shaft rotatably supported by a frame via a bearing and can clamp and unclamp a tool by moving in the axial direction; and a collet chuck that is movable in the axial direction near the other end of the main shaft. a spindle-side actuating member that is provided on the main shaft and can be operated integrally with the collet chuck via a drawbar; and a clamp attachment that is provided near the other end of the spindle and biases the spindle-side actuator to clamp the tool with the collet. a fixed-side actuating member supported movably in the axial direction of the main shaft by the frame and capable of abutting the main-shaft-side actuating member; a main shaft fixing drive means that is driven to press the main shaft-side operating member with a force smaller than the urging force of the urging means; and a drive means for driving the fixed-side operating member in a direction opposite to the urging direction of the urging means. A tool attachment/detachment device comprising: an unclamp drive means for pressing the main shaft side operating member into contact with a force greater than the urging force of the urging means.