JPH05245756A - Machine tool provided with oscillation function - Google Patents

Abstract

PURPOSE:To reduce production costs for oscillation by installing an oscillation cylinder mechanism in the rear of a spindle head and also a spring such as a disc spring or the like and a push rod in a holder body of a tool holder, respectively. CONSTITUTION:A spindle 2 is rotated, and a grinding wheel 37 is also rotated together with a holder body 32 of a tool holder 31 and a ball spline shaft 34 as one body. In addition, an oscillation cylinder mechanism 15 installed in the rear of a spindle head 1 is retractably operated, and at the time of forward operation, a push rod 42 is advanced forward as compressing a spring 40 installed in the holder body 32, and at the time of backward operation, the push rod 42 is retracted by dint of restoring force of the spring 40, thereby having the spline shaft 34 and the grinding wheel 37 advanced or retracted by advance or retreat of the push rod 42. Thus, the grinding wheel 37 is advanced or retracted by the specified stroke in the axial direction as rotating it, then a workpiece is ground by the grinding wheel 37 as forcing it into oscillation.

Description

Detailed Description of the Invention

[0001]

This invention relates to a machining center,
The present invention relates to a machine tool such as a grinding center, especially a machine tool having an oscillation function.

[0002]

2. Description of the Related Art In a machine tool, when a tool holder having a grindstone mounted on a main shaft is held and a workpiece is ground by the grindstone, is the grinding wheel oscillated by axially moving the main shaft? The main axis head is moved in the axial direction by using the chopping function of the numerical control device.

[0003]

However, the conventional method for oscillating the grindstone by moving the main shaft in the axial direction has a problem that the mechanism is complicated and the cost is increased.
In addition, there is a problem in that the main spindle head is moved at a slow moving speed and the oscillation cycle cannot be increased because the main spindle head is heavy.

The present invention solves the above-mentioned problems,
To provide a machine tool with an oscillation function that has a simple mechanism, can reduce the cost for performing oscillation, can reduce the weight of the member that advances and retracts the grindstone in the axial direction, and can accelerate the oscillation cycle. It is intended.

[0005]

A machine tool having an oscillation function according to the present invention comprises a holder main body and a ball spline shaft supported by the main body so as to be capable of advancing and retreating in the axial direction and transmitting rotational force from the holder main body. And a spring that is housed in the holder body and biases the spline shaft in the backward direction,
A tool holder having a push rod that is supported by the main body to move the spline shaft forward and backward, and a grindstone attached to the tip of the spline shaft protruding from the front end of the main body, and the holder main body is the main shaft of a machine tool. An oscillation cylinder mechanism is provided which is detachably held at the tip portion and which moves the push rod forward and backward behind the spindle of the spindle head.

[0006]

In the machine tool according to the present invention, the spindle is rotated to rotate the grindstone integrally with the holder main body of the tool holder and the ball spline shaft. Further, the oscillation cylinder mechanism provided on the rear side of the main spindle of the main spindle head is moved forward and backward, the push rod is advanced while compressing the spring provided in the holder main body during forward movement, and the restoring force of the spring is applied during backward movement. The push rod is moved backward, and the push rod is moved back and forth to move the spline shaft and the grindstone back and forth. By the above-described operation, the grindstone is rotated to advance and retreat in the axial direction with a predetermined stroke, and the workpiece is ground by the grindstone while oscillating.

Oscillation can be performed with such a simple construction that a cylinder mechanism for oscillation is provided behind the spindle of the spindle head, and a spring such as a disc spring and a push rod are provided in the holder body of the tool holder. .. In addition, the pistons of the cylinder mechanism and the push rods of the tool holder are the main components that move forward and backward in the axial direction, and since the weight of these is light, the oscillation cycle can be accelerated.

[0008]

DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENT A first embodiment of the present invention will now be described with reference to FIG.
This will be described with reference to FIG. In FIG. 1, reference numeral 1 is a spindle head, and a spindle 2 is rotatably provided in a spindle head main body 1a.
Is pivotally supported. Tapered hole 2a provided at the tip of the main shaft 2
Includes a taper shank portion 32d of the tool holder 31 described later.
Is detachably attached, and the key groove 32e provided in the tool holder 31 is engaged with the key 3 provided at the tip of the main shaft 2.

A spindle drive motor 5 is fixed to a motor base 4 fixed to the outer periphery of the spindle head main body 1a, and the spindle 2 is rotated by driving the motor 5 via a pulley 6, an endless belt 7 and a pulley 8. I am doing it. A collet 9 is housed in the main shaft 2, and a pull stud 36 projecting to the end of the tool holder 31 is releasably clamped by the tip of the collet 9.

The end portion of the collet 9 is engaged with the tip portion of the draw bar 10, and the draw bar 10 is accommodated in the main shaft 2 coaxially therewith. A drawbar disc spring 11 is interposed between the main shaft 2 and the drawbar 10. The drawbar 10 is biased rearward by these disc springs 11 and a clamping force is applied to the pull stud 36 by the tip of the collet 9. ing.

Behind the spindle 2 in the spindle head body 1a,
A tool unclamping hydraulic cylinder mechanism 12 is provided, and a piston 14 fitted in a cylinder 13 of the cylinder mechanism 12 faces the rear end of the draw bar 10. When the piston 14 moves forward, the piston 14 comes into contact with the draw bar 10 to move it forward, and the pull stud 3 by the collet 9 is moved.
Release the clamp of 6 and put it in the unclamped state.
The tool holder 31 can be pulled out from the spindle 2.

The above construction is almost the same as the construction of a general spindle head and spindle of a machine tool such as a machining center. Although not shown in the drawings, the configuration and operation of the bed, column, close beam, etc. are similar to those of a general machine tool. In this embodiment, the spindle head body 1
The cylinder 16 of the oscillation hydraulic cylinder mechanism 15 is fixed in a, and the oscillation hydraulic cylinder mechanism 15 is arranged behind the spindle 2 and the tool unclamping hydraulic cylinder mechanism 12.

A base end of an operation rod 18 extending forward is fixed to a piston 17 fitted in a cylinder 16 of a hydraulic cylinder mechanism 15 for oscillation. Operating rod 1
Reference numeral 8 is arranged coaxially with the main shaft 2, the drawbar 10, and the piston 14 of the tool unclamping hydraulic cylinder mechanism 12. Further, the operating rod 18 has a tip end portion 18a slidably fitted into the piston 14 of the tool unclamping hydraulic cylinder mechanism 12, and a small diameter portion 18b connected to the front surface of the tip end portion 18a penetrates the drawbar 10. Hole 10
A push rod 4 loosely inserted in a and protruding rearward from the tip 18c and the pull stud 36 of the tool holder 31.
Abutting the end of 2.

In the tool holder 31, a ball spline shaft 34 is supported by a ball spline nut 33 fitted and fixed in a front member 32a of a holder body 32 via balls (not shown) so as to be able to advance and retract in the axial direction. .. Holder body 3
2, a front end plate 32b is bolted and fixed to the front end of the front member 32a, and a dustproof cap 35 is fixed to the outer peripheral surface of the front end of the front member 32a by screw fitting. The rear member 32c is fixed by bolting. A substantially cylindrical pull stud 36 is fastened and fixed to the rear member 32c of the holder body 32 by screw fitting.

The pull stud 36 is projected rearward of the end of the holder body 32, and a taper shank portion 32d having a smaller diameter toward the end is formed on the end side of the rear member 32b. A key groove 32e is formed in the rear member 32c (see FIG. 1). A grindstone 37 is detachably fixed to a front end portion of the spline shaft 34 projecting forward of the dustproof cap 35, and a connecting member 38 also serving as a bearing housing is fixed to a rear end portion of the spline shaft 34 with a bolt 39. There is.

A plurality of disc springs 40 are interposed between the tip end face of the connecting member 38 and the end face of the front portion 32a of the holder body 32. The disc spring 40 causes the connecting member 38 and the spline shaft 34 to move rearward. The holder body 3
It is housed in 2. A push rod 42 is rotatably supported in the connecting member 38 by front and rear bearings 41, 41. The push rod 42 has a connecting member 38.
The axial movement of the pull stud 36 is restricted and the end portion of the pull stud 36 projects from the end of the pull stud 36.
It is arranged coaxially with No. 4. By rotatably supporting the push rod 42, the rotation of the connecting member 38 can be absorbed without being transmitted to the operation rod 18.

Next, the operation of this embodiment will be described. The taper shank portion 32d of the tool holder 31 is attached to the spindle 2
Collet 9 provided in the main shaft 2 by being fitted in the tapered hole 2a of
The pull stud 36 of the tool holder 31 is clamped by. In this state, the spindle drive motor 5 is driven to rotate the spindle 2, and the key 3 and the tool holder 31 provided on the spindle 2
The holder main body 32 of the tool holder 31 is rotated integrally with the main shaft 2 by engaging with the key groove 32e provided in the holder main body 32 of the ball, and the ball spline nut 33 and a ball (not shown) Spline shaft 34
Is rotated, and the grindstone 37 is rotated together with the spline shaft 34.

Next, the oscillation hydraulic cylinder mechanism 15 arranged behind the spindle 2 of the spindle head 1 is operated to move the piston 17 and the operating rod 18 of the cylinder mechanism 15 downward. As the operation rod 18 advances, the push rod 42 of the tool holder 31 is pushed downward, the disc spring 40 is compressed, and the connecting member 38, the ball spline shaft 34, and the grindstone 37 are advanced.

Further, the oscillation hydraulic cylinder mechanism 15 is reversely actuated to move the piston 17 and the operating rod 1.
8 is retracted upward, and the restoring force of the disc spring 40 causes the connecting member 38, the push rod 42, the ball spline shaft 3
4 and the grindstone 37 are retracted. By repeating the above-described operation, the grindstone 37 is rotated to advance and retreat in the axial direction with a predetermined stroke, and the grindstone 3 is oscillated.
A workpiece (not shown) is subjected to grinding by 7.

3 and 4 show a second embodiment of the present invention. In the second embodiment, as shown in FIG. 3, the tip end portion 18a of the operating rod 18 whose base end portion is fixed to the piston 17 of the oscillation hydraulic cylinder mechanism 15 is connected to the piston 14 of the tool unclamping hydraulic cylinder mechanism 12. It is slidably fitted in. An auxiliary rod 20 is rotatably supported by front and rear bearings 19 and 19 in a hole portion 18e provided in a tip portion 18d of the operation rod 18, and the auxiliary rod 20 moves axially with respect to the operation rod 18. Is restrained.

An intermediate rod 21 is provided at the tip of the auxiliary rod 20.
The ends of are abutted. The intermediate rod 21 is fitted in a draw bar 10 provided in the main shaft 2 so as to be movable in the axial direction. A flange 22 is provided at the tip of the intermediate rod 21, and a small disc spring 23 is provided between the flange 22 and the drawbar 10.
With the disc springs 23 interposed, the intermediate rod 2
1 is urged backward.

The tip of the intermediate rod 21 is brought into contact with the end of the push rod 42 which projects rearward from the pull stud 36 of the tool holder 31. The small disc spring 23 is housed in the tip portion of the draw bar 10. Further, as shown in FIG. 4, in the tool holder 31, the end portion of the connecting member 38 is connected to the end small diameter portion 34 a of the ball spline shaft 34 by screw fitting, and the push rod is integrally formed with the tip of the connecting member 38. 42 is provided.

To perform the oscillation, the oscillation hydraulic cylinder mechanism 15 is actuated, and the piston 17, the operating rod 18, and the auxiliary rod 20 of the cylinder mechanism 15 are advanced downward. When the auxiliary rod 20 moves forward, the small disc spring 23 is compressed and the intermediate rod 21
Moves forward, the push rod 42 of the tool holder 31 is pushed downward by the intermediate rod 21, the disc spring 40 is compressed, and the grindstone 37 and the like are moved forward.

Further, the oscillation hydraulic cylinder mechanism 15 is reversely operated to retract the piston 17 and the operating rod 18 upward, and the push rod 42 of the tool holder 31 is moved.
Etc. are retracted by the restoring force of the disc spring 40. At this time, the intermediate rod 21 is retracted by the restoring force of the small disc spring 23. The configuration of the second embodiment other than that described above,
The operation is the same as in the first embodiment. That is, in the first embodiment, the push rod of the tool holder is rotatably supported by the bearing, while in the second embodiment, the auxiliary rod is rotatably supported by the bearing on the operation rod on the spindle head side. An intermediate rod is interposed between the push rod and the push rod to simplify the mechanism of the tool holder. Further, the same reference numerals as those in FIGS. 1 and 2 in FIGS. 3 and 4 denote corresponding parts.

[0025]

As described above, the machine tool provided with the oscillation mechanism of the present invention has a holder main body and a ball supported on the main body so as to be capable of advancing and retracting in the axial direction and transmitting rotational force from the holder main body. A spline shaft, a spring that is housed in a holder body and biases the spline shaft in a backward direction, a push rod that is supported by the body and that advances and retracts the spline shaft, and the spline shaft that projects from the front end of the body. Oscillation that has a tool holder equipped with a grindstone attached to the tip, holds the holder body detachably on the tip of the spindle of the machine tool, and moves the push rod forward and backward behind the spindle of the spindle head. Since the cylinder mechanism is provided, the following effects can be obtained.

That is, while rotating the main shaft and rotating the ball spline shaft and the grindstone through the holder main body of the tool holder, etc., the oscillation cylinder mechanism is moved forward and backward to push the rod provided on the tool holder. By moving the spline shaft and the grindstone back and forth in the axial direction through the, the grindstone grinds the workpiece with oscillation.

Oscillation can be performed with such a simple structure that a cylinder mechanism for oscillation is provided behind the spindle of the spindle head, and a spring such as a disc spring and a push rod are provided in the holder body of the tool holder. ,
Therefore, the cost for performing oscillation can be reduced. In addition, the pistons of the cylinder mechanism and the push rods of the tool holder are the main components that move forward and backward in the axial direction, and since the weight of these is light, the oscillation cycle can be accelerated.

[Brief description of drawings]

FIG. 1 is a vertical sectional view of a spindle head portion of a machine tool having an oscillation function according to a first embodiment of the present invention.

FIG. 2 is an enlarged vertical cross-sectional view showing the tool holder of FIG.

FIG. 3 is a vertical cross-sectional view of a spindle head portion of a machine tool including an oscillation mechanism according to a second embodiment of the present invention.

FIG. 4 is an enlarged vertical cross-sectional view showing the tool holder of FIG.

[Explanation of symbols]

 1 Spindle Head 1a Spindle Head Body 2 Spindle 3 Key 5 Spindle Drive Motor 9 Collet 10 Drawbar 12 Hydraulic Cylinder Mechanism for Tool Unclamping 15 Hydraulic Cylinder Mechanism for Oscillation 17 Piston 18 Operation Rod 20 Auxiliary Rod 21 Intermediate Rod 31 Tool Holder 32 Holder Main body 32d Tapered shank portion 32e Key groove 33 Ball spline nut 34 Ball spline shaft 36 Pull stud 37 Grindstone 38 Connecting member 40 Disc spring 42 Push rod

Claims (1)

[Claims] 1. A holder main body, a ball spline shaft supported by the main body so as to be capable of advancing / retreating in the axial direction and transmitting a rotational force from the holder main body, and the spline shaft accommodated in the holder main body and attached in the backward direction. A holder main body having a biasing spring, a push rod for supporting the main body to move the spline shaft forward and backward, and a grindstone attached to a tip end portion of the spline shaft protruding from a front end of the main body. Is detachably held at the tip of the spindle of the machine tool, and an oscillation cylinder mechanism for advancing and retracting the push rod is provided behind the spindle of the spindle head. A machine tool having an oscillation function.