JPH074684B2 - Double spindle structure with adjustable cutting depth - Google Patents

Description

Description: BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to, for example, a spindle structure of a machine tool having a tool radius correcting function, and a simple cutting method for adjusting a tool cutting amount in a radial direction to correct the tool diameter. The present invention relates to a double spindle structure in which the amount of insertion can be adjusted.

2. Description of the Related Art Conventionally, a means using a face plate having a tool slider or an eccentric tool holder has been adopted as a means for changing the cutting depth in the radial direction by inserting and removing the cutting edge of a tool fitted into a spindle. However, there were drawbacks in that the operability was poor and automatic adjustment was not possible. As a means for solving this, there is a conventional technique disclosed in Japanese Patent Publication No. 49-16398. This drives an inner main shaft eccentrically and pivotally supported by an outer main shaft by a drive source to rotate the outer main shaft in the same speed and the same direction as the inner main shaft through a differential gear device and adjust the phase of the differential gear device. The devices are associated and coupled to adjust the coaxial phase with the outer and inner spindles. That is, it is characterized in that the differential gear device is the main element. Although the present invention solves the above-mentioned drawbacks, it has a drawback that the structure is complicated and the number of parts is large, so that high precision adjustment is difficult.

DISCLOSURE OF THE INVENTION Problems to be Solved by the Present Invention The present invention solves the above-mentioned drawbacks and the like, and has a simple structure, a small number of parts, and an adjustable cutting depth capable of forming the entire device with high accuracy and at low cost. It is to provide a heavy spindle structure.

Means for Solving the Problems For this purpose, the present invention fixes gears having opposite twist angles on an outer main shaft and an inner main shaft eccentrically supported by the outer main shaft, and the gears have opposite twist angles on the same axis. A double main spindle structure, in which a helical gear integrally formed with a gear is meshed with the helical gear, and the helical gear is moved in the axial direction thereof by a moving means so that the cutting amount can be adjusted, is used as the means.

Action The helical gear is moved in the axial direction by a predetermined amount, the outer and inner spindles are rotated in opposite directions to change the rotation phase, and the tool insertion hole position is changed to adjust the depth of cut. This operation is effective even while the spindle is rotating.

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

As shown in FIG. 1, an outer main shaft 4 is pivotally supported in the quill 1 via bearings 2 and 3. Inside the outer spindle 4, the inner spindle 5
Is eccentrically supported. The eccentricity e is displayed by the distance between the center _{O1 of the} outer main shaft 4 and the center _{O2 of the} inner main shaft 5, as shown in FIG. A tool (not shown) is provided on the tip side of the inner spindle 5.
The hole 6 into which the hole is inserted is formed. The hole 6 is the inner spindle 5.
Is formed eccentrically with respect to (the amount of eccentricity is e). Specifically, the shank portion of the tool is fitted in the hole 6, and the cutting edge of the tool is arranged in the radial direction of the main shaft. Gears 7, 8 having opposite twist angles are fixed to the outer main shaft 4 and the inner main shaft 5, and an inner gear 11 meshes with the gear 8. The gear 7 and the internal gear 11 have the same outer diameter (pitch diameter). The gear 8 and the inner gear 11 are used for the outer and inner main shafts 4,5.
This is for canceling out the eccentricity of and rotating them smoothly.

The helical gear 9 is formed by integrally forming gears 9a and 9b having opposite twist angles on the same axis, and the gears 9a and 9b are arranged to mesh with the gear 7 and the internal gear 11, respectively. The gears 9a and 9b are rotatably supported by the screw shaft 10 as the moving means, and are formed so as to be movable in the axial direction by the rotation of the screw shaft 10. A motor 12 for driving the screw shaft 10 is connected to the screw shaft 10. Further, the internal gear 11 (may be the gear 7) meshes with a gear 14 connected to a main shaft rotary motor 13.

Next, the operation of this embodiment will be described.

When the motor 12 is rotated, the screw shaft 10 rotates and the helical gear 9 moves in the axial direction. As a result, the gear 7 and the internal gear 11
And rotate in opposite directions to change the rotation phases of the outer and inner circumference side main shafts 4, 5. Therefore, the phases of the outer and inner spindles are shifted by this amount.

On the other hand, rotation of the inner main shaft 5 may be performed by operating the main shaft rotation motor 13. In this case, as the internal gear 11 rotates, the helical gear 9
Also rotates, and the gear 7 is rotated by the gear 9a, but the inner main shaft 5
Is supported by the outer main shaft 4, so there is no problem.

Further, by rotating the string motor 12 while the inner main shaft 5 is rotating, the same phase change as described above can be given.

The adjustment of the cutting depth of the tool blade will be described with reference to FIG.

As described above, the outer spindle 4 and the inner spindle 5 are eccentric by the eccentric amount e, and the hole 6 of the tool is also eccentric by the eccentric amount e. Therefore, the hole 6 is located on the circle 15 having the radius e (the amount of eccentricity) with the center _{O2 of the} inner main shaft 5 as the center. The cutting amount a of the cutting edge, where the rotation phase angle is θ, is as follows.

a = e (1-cos θ) Therefore, in order to obtain the predetermined cutting amount a, the rotational phase may be adjusted by the angle θ that satisfies the above expression.

In the present embodiment, the eccentricity e of the outer spindle 4 and the inner spindle 5 and the eccentricity e of the hole 6 of the tool have the same value, but the invention is not limited to this.

This embodiment is a simple one using an integral structure of the helical gear 9, has a small number of parts, and can be implemented at low cost, and each component can be processed and assembled with high accuracy, and the overall accuracy can be improved. .

EFFECTS OF THE INVENTION As is clear from the above description, according to the present invention, the effect that the structure is simple and can be implemented at a low cost and the accuracy of the device can be improved is enhanced.

[Brief description of drawings]

FIG. 1 is an overall configuration diagram of an embodiment of the present invention, and FIG. 2 is an explanatory diagram for explaining a cutting amount of a tool. 1 ... Quill, 2, 3 ... Bearing, 4 ... Outer spindle, 5 ...
Inner main shaft, 6 …… hole, 7,8,14 …… gear, 9 …… helical gear, 9a, 9b …… gear, 10 …… screw shaft, 11 …… internal gear, 1
2 …… motor, 13 …… spindle rotation motor, 15 …… yen.

Claims (1)

[Claims] 1. An outer main shaft pivotally supported by a quill, and an inner main shaft which is eccentrically pivotally supported in the outer main shaft and has an eccentric hole into which a tool is inserted. In the double spindle structure formed to adjust the rotational phase of the tool to adjust the cutting amount in the radial direction of the tool, the double spindle structure is fixed to the outer and inner spindles, and is simultaneously formed on the gears having opposite helix angles. In order to engage with each other, a helical gear with integrally formed gears with opposite twist angles is provided on the same axis,
A double-spindle structure with adjustable cutting depth, characterized in that a moving means for moving the helical gear along its axis is provided.