JPS6216249Y2 - - Google Patents

Description

DETAILED DESCRIPTION OF THE INVENTION The present invention relates to a tool correction device for a machine tool equipped with an automatic tool changer.

Conventionally, in a machine tool equipped with an automatic tool changer, such as a boring machine, in order to correct the tool, a nut is attached to the part of the tool that is exposed to the outside of the spindle while the tool is mounted on the spindle. The rotation of the nut is stopped from the outside, and the main shaft is rotated at low speed to move the nut back and forth by the relative rotation of the nut, and the position of the cutting edge of the tool is determined by using the inclined surface provided on the rod that moves back and forth with the nut. It had a structure that allowed it to move in and out in the radial direction of the main shaft. Therefore, in order to perform tool compensation, steps such as once stopping the rotation of the spindle, locking the nut from the outside, and rotating the spindle by a predetermined angle are required, so it takes a long time to make tool compensation, and the machining process using the tool is interrupted. However, there was a drawback that facing machining could not be performed because tool correction could not be performed.

The present invention was devised in view of the above circumstances, and its purpose is to provide a tool correction device that can correct a tool while the spindle is rotating and allows the tool to be freely attached to and detached from the spindle.

Embodiments of the present invention will be described below with reference to the drawings. FIG. 1 is a sectional view showing a main part of a spindle head 1 of a boring machine to which the present invention is applied. The spindle head 1 is movable relative to a workpiece in order to perform machining. Bearings 2, 3,
A main shaft 5 is rotatably incorporated via a shaft 4. As the structure for moving the spindle head 1 relative to the workpiece and the structure for rotationally driving the spindle 5, conventionally provided structures can be used.
The explanation will be omitted. A tool 6 can be freely attached to and removed from the tool insertion hole 5a of the main shaft 5 by an automatic tool changer. A pull stud 7 is hinged to the rear end of the tool 6, and the tool 6 can be clamped to the main shaft 5 by locking the pull stud 7 in a conventional manner when the tool is installed. In this embodiment, locking is performed by the collect method described below.

A cover plate 8 is fixed to the spindle head 1 at the rear of the spindle 5, and a piston 9, which uses the cover plate 8 and the spindle head 1 as a cylinder block, moves back and forth along an extension of the axis A of the spindle 5. will be installed on the A through hole 9a is formed in the piston 9 along this axis, and an abutment rod 10 having screw portions 10a and 10b screwed into the front and rear portions thereof is fitted into the through hole 9a. A nut 11 is screwed into the threaded portion 10a at the front of the abutment rod 10, and a nut 13, which interposes the arm 12 between it and the piston 9, is screwed into the threaded portion 10b at the rear of the abutment rod 10. , the abutment rod 10 is connected to the piston 9 by both nuts 11 and 13.
It is fixed to the shaft so that its axial position can be freely adjusted. On the other hand, a series of holes 5b and 5c are bored in the main shaft 5 along the axis A of the main shaft 5, and communicate with the tool insertion hole 5a. A hollow shaft 15 that is screwed into the collet 14 is inserted into the shaft 5c. An abutment plate 18 is attached to the vicinity of the rear end of the hollow shaft 15 by nuts 16 and 17, and the abutment plate 18
A disc spring 19 is interposed between the main shaft 5 and the main shaft 5. The collet 14 and the hollow shaft 15 are connected to the disc spring 1.
It always takes the backward position by the biasing point 9. In this state, the collet 14 can lock the pull stud 7 and clamp the tool 6.

The positional relationship between the abutment rod 10 and the hollow shaft 15 is such that when the piston 9 is always in the retracted position, a predetermined interval is provided between the tip 10c of the abutment rod 10 and the rear end 15a of the hollow shaft 15. , when the piston 9 assumes the forward position when the rotation of the main shaft 5 is stopped, the abutting rod 10 contacts the hollow shaft 15, moves the hollow shaft 15 forward by a predetermined distance, and releases the locking of the pull stud 7 by the collet 14. It is.

When the pull stud 7 is released, the tool 6 can be removed by the automatic tool changer. A dog 20 is attached to the arm 12, and limit switches 21, 22 are attached to the spindle head 1.
When the piston 9 is in the retreated position, the dog 20 abuts against the limit switch 21 to confirm the clamping state of the tool 6, and the piston 9
When the tool 6 is in the forward position, a dog 20 abuts against a limit switch 22 to confirm the unclamped state of the tool 6. Reference numeral 23 denotes a key provided at the end of the spindle.

Next, the structure of the tool 6 will be explained. Tool 6
has a holder 24, and the holder 24 is provided with a dovetail groove 24a parallel to the radial direction of the main shaft 5, and a guide portion 25a of a slider 25 is fitted into the dovetail groove 24a (see Fig. 2). . The holder 24 has brackets 26 and 27 at positions that sandwich both ends of the groove 24a.
A spring 28 is interposed between one bracket 26 and the slider 25, and a stopper 29 for the slider 25 biased by the spring 28 is screwed into the other bracket 27. is fixed with a nut 30. A flange 31a of a cutting tool holder 31 is fixed to the front portion of the slider 25, that is, to the outside of the tip of the tool body in the axial direction, and a cutting tool 32 necessary for machining is attached to the cutting tool holder 31. Further, a rack 33 is attached to the rear portion of the slider 25 parallel to the radial direction in which the slider 25 moves along the dovetail groove 24a. Holder 24 and the pull stud 7
A series of holes 24b and 7a are bored along the axis of the main shaft, and a rack bar 34 as a first moving operation means is fitted into both holes 24b and 7a so as to be movable in the axial direction. 34b is located approximately near the rear end 7b of the pull stud 7. The holder 24 is rotatably provided with a pinion 35 that meshes with both the rack 33 and the rack portion 34a of the rack bar 34. The positional relationship between the rack 33, the rack portion 34a of the rack bar 34, and the pinion 35 is as follows:
When the rack bar 34 moves forward, the rack 33
is adapted to move in the opposite direction to the direction of the biasing force of the spring 25. Therefore, rack bar 3
4 moves forward or backward, the position of the tip 32 with respect to the main shaft axis A is displaced.

Next, the second moving operation means will be explained. The hollow shaft 15 has a through hole 15b, and a rod 36 as a second moving operation means is fitted into the through hole 15b so as to be freely movable in the axial direction. A retaining pin 37 is attached to the hollow shaft 15 so as to traverse the through hole 15b in the radial direction, and the rod 36 has a pin insertion groove 36a having a predetermined length in the axial direction in which the retaining pin 37 engages. (See Figure 3). Therefore, the rod 36 can move back and forth relative to the hollow shaft 15 within the range in which the pin insertion groove 36a allows movement of the retaining pin 37. Rod 36 and hollow shaft 1
A spring 38 is interposed between the rod 36 and the rod 5, and the rod 36 always assumes a backward position due to the biasing force of the spring 38. The positional relationship between the rod 36 and the rack bar 34 is such that when the rod 36 is always in the backward position, a predetermined distance is provided between the tip 36b of the rod 36 and the rear end 34b of the rack bar 34, and when the rod 36 is in the forward position. The rod 36 pushes the rack bar 34 forward when it is removed.

Next, the third moving means will be explained. A block 39 having a notch 39a that allows the arm 12 to pass through is fixed to the rear part of the cover plate 8, and a plate 40 is fixed to the rear part of the block 39.
is fixed to the plate 40, and a servo motor 41 is attached to the rear of the plate 40. The servo motor 4
The bearing 4 of the block 39 is attached to the output shaft 41a of the block 39.
Hole 44 of nut body 44 supported by 2, 43
a are fitted through the key 45 so that rotational force can be transmitted. A threaded portion 46a of a threaded bar 46 serving as a third moving operation means is screwed into the threaded portion 44b of the nut body 44. The threaded bar 46 is fitted into the through hole 10d provided in the abutting rod 10 via a key 47 so as to be non-rotatable and movable back and forth. A ball or bearing 48 is provided at the tip of the threaded bar 46.
The positional relationship between the threaded bar 46 and the rod 36 is such that when the threaded bar 46 is always in the retracted position, a predetermined distance is provided between the bearing 48 and the rear end 36c of the rod 36, and when the threaded bar 46 is in the forward position. When taking the position, the bearing 48 pushes the rod 36 forward against the urging force of the spring 38.

Next, the operation of the tool correction device will be explained.
When the nut body 44 is rotated by a predetermined angle by the rotational drive of the servo motor 41 while the screw bar 46 is in the retracted position, the screw bar 46 moves forward and presses the rod 36 forward. At this time, even if the rod 36 rotates due to the rotation of the main shaft 5, the bearing 48 comes into contact with the rear end of the rod 36, so that the forward movement of the screw bar 46 is prevented while allowing the rod 36 to rotate relative to the screw bar 46. can be transmitted to. The rod 36 pushes the rack bar 34 forward, and the slider 25 moves the spring 2 through the pinion 35 and the rack 33.
It moves parallel to the radial direction of the main shaft against the urging force of 8. As the slider 25 moves, the position of the cutting edge of the cutting tool 32 relative to the spindle axis A moves by a predetermined amount. The tool compensation operation can be performed while the spindle is rotating or stopped, so facing machining is possible, and curved surface machining can be performed in combination with relative movement of the spindle head parallel to the spindle axis A with respect to the workpiece. Can be done. By attaching a plurality of bits to the tool and changing the distance from the spindle axis, it is also possible to selectively use these bits for machining. Further, the amount of wear on the tool can be separately detected and the tool correction device can perform tool correction corresponding to the amount of wear.

As is clear from the above explanation, the tool correction device according to the present invention changes the position of the cutting edge of the tool from the rear of the tool inserted into the spindle using the first to third moving operation means, so when the spindle is stopped, Not only
It is possible to move the tool even while the spindle is rotating, making it possible to perform facing machining and boring on curved surfaces, and the tool can be attached and detached, making it possible to work with automatic tool changers. Can be applied to machines. In addition, it is possible to use conventional structures for attaching tools to the spindle, clamping structure, and spindle drive structure, so by applying the present invention, the structure of the spindle and spindle head can be changed as little as possible. It is sufficient and has a compact structure.

In addition, since the tool holder is located in the axial direction outside the tip of the tool body, a large amount of radial movement can be achieved.
In addition to being able to insert multiple tools, it is also versatile in that it can be used for processes other than boring.

[Brief explanation of the drawing]

FIG. 1 is a cross-sectional view showing a tool to which a tool correction device according to an embodiment of the present invention is applied and the vicinity of the spindle, and FIG. 1A is continuous with FIG. 1B. Figure 2 is the first
Figure 3 is a cross-sectional view taken along the - line in Figure 1.
FIG. 1...Spindle head, 5...Spindle, 6...Tool, 7
a, 24b...hole, 28...spring, 34...
...Rack bar, 36...Rod, 38...Spring, 41...Motor, 46...Screw bar.

Claims (1)

[Scope of utility model registration request] In a tool correction device for correcting a replacement tool that is attached to and removed from a spindle end of a spindle that is rotationally driven by a spindle head of a machine tool, a rack that is movably inserted in an axial direction on a spindle axis in the exchange tool body; a movement direction converting member combining a pinion; a moving tool that meshes with the pinion of the movement direction converting member and is provided in the axial direction so as to be movable in the radial direction at the tip of the exchange tool body; a clamping means slidably inserted in the hollow spindle in the axial direction to clamp a replacement tool inserted into the tool insertion opening at the tip of the spindle; an unclamping means provided to release the clamp by moving the clamping means in the axial direction; 1. A tool correction device comprising a moving operation means for moving a tool provided at the tip of an exchange tool body in a radial direction by the movement operation means.