JPH06624U - Movable table - Google Patents

Abstract

(57) [Abstract] [Purpose] To accurately control the position of the mounting table even if the ball screw thermally expands with a simple structure and without increasing the cost. [Structure] The left end of the ball screw 12 is supported by a support portion 16 so as to be rotatable and non-displaceable in the axial direction of the ball screw 12. The right end of the ball screw 12 is spline-coupled to the output shaft 17 of the servomotor 13. Table 1
The one screwing portion 21 is screwed into the ball screw 12. When the ball screw 12 thermally expands rightward, the left end portion of the displacement portion 22 is displaced leftward by substantially the same amount. The heat insulating material 18 does not conduct heat to the mounting portion 23, and thus the mounting portion 23
It does not thermally expand itself. For this reason, the mounting portion 23 has the displacement portion 2
Move by a displacement of 2.

Description

[Detailed description of the device]

[0001]

[Industrial applications]

 The present invention relates to a movable mounting table for mounting a turret for holding a cutting tool in a machine tool, for example.

[0002]

[Prior art]

 The structure of this type of movable mounting table will be described with reference to FIG. The left end of the ball screw 50 is supported by a support portion 51 so as to be rotatable and displaceable in the axial direction of the ball screw 50. The right end of the ball screw 50 is connected to the output shaft 53 of the servomotor 52. The bottom of the mounting table 54 is screwed in the middle of the ball screw 50. Therefore, when the ball screw 50 is rotationally driven by the servo motor 52, the mounting table 54 moves in the left-right direction in the drawing. A turret (not shown) holding a cutting tool for cutting the workpiece, for example, is fixed to the upper portion of the mounting table 54 to adjust the cutting position and the cutting amount of the workpiece. Must be controlled in the correct position.

[0003]

[Problems to be solved by the device]

 By the way, the ball screw 50 undergoes thermal expansion in the axial direction of the ball screw 50 by receiving heat from the servo motor 52 and a machine tool, which causes a problem that the mounting table 54, that is, the cutting tool cannot be accurately controlled in position. As a countermeasure against this, conventionally, for example, a touch sensor is used to electrically correct the position when the tip of the blade of the cutting tool comes into contact with the workpiece, but the configuration is complicated, and There is a problem that the cost increases. An object of the present invention is to provide a movable mounting table that has a simple structure and does not increase the cost, and can accurately control the position of the mounting table even when the drive shaft thermally expands.

[0004]

Means for Solving the Problems A movable mounting table according to the present invention includes a drive shaft, one end of which is fixed so as not to be displaceable in the axial direction, and the other end of which is displaceable in the axial direction by thermal expansion, and a drive shaft. The mounting table is provided with a mounting table that moves in the axial direction by rotation around the axis of the shaft, and the mounting table has a displacement section that is screwed onto the drive shaft, a mounting section that is connected to the displacement section, and the displacement section and the mounting section. It is characterized in that it has a heat insulating material disposed between the parts, and the mounting part is thermally displaced in a direction opposite to the thermal expansion direction of the drive shaft.

[0005]

【Example】

 FIG. 1 shows a perspective view of a movable mounting table for mounting a turret for holding a cutting tool in a machine tool. In this figure, the mounting table 11 reciprocates by rotating the ball screw 12 around the axis by the servo motor 13. A pair of guide receivers 14 are arranged in parallel at both ends of the bottom of the mounting table 11. Each guide receiver 14 is slidably supported by a guide 15. As a result, the mounting table 11 can be moved in the left-right direction in the drawing along the guide 15.

FIG. 2 shows a sectional view of the mounting table of FIG. The left end of the ball screw 12 is rotatably and non-displaceably supported by the support portion 16 in the axial direction of the ball screw 12. The right end of the ball screw 12 is splined to the output shaft 17 of the servomotor 13. Therefore, the rotation of the output shaft 17 is transmitted to the ball screw 12, and the right end of the ball screw 12 can be displaced in the axial direction of the ball screw 12.

A screwing portion 21 formed on the bottom of the mounting table 11 is screwed in the middle of the ball screw 12. Therefore, when the ball screw 12 is rotationally driven by the servo motor 13, the mounting table 11 moves in the left-right direction in the drawing.

A displacement portion 22 is formed on the screwing portion 21. The displacement portion 11 extends from the screwing portion 21 to the left in the figure. The left end of the displacement portion 22 is connected to the mounting portion 23, and the mounting portion 23 extends rightward from this connection portion substantially in parallel with the displacement portion 22. A turret (not shown) holding a cutting tool is fixed to the upper surface of the mounting portion 23. A gap is formed between the displacement portion 22 and the mounting portion 23, and the heat insulating material 24 is inserted into this gap.

As described above, the left end of the ball screw 12 is supported so as not to be displaced in the axial direction of the ball screw 12. For this reason, when heat is transferred to the ball screw 12, the ball screw 12 thermally expands in the right direction in the drawing with reference to the support portion 16. On the other hand, when heat is transferred to the displacing portion 22 of the mounting table 11, the displacing portion 22 thermally expands in the left direction in the figure with the screwing portion 21 as a reference. The amount of displacement of the ball screw 12 due to thermal expansion increases as the distance from the support portion 16 increases, but at a position where the screwing portion 21 of the mounting table 11 is located on the ball screw 12 most frequently (for example, the central portion of the ball screw 12). The displacement amount due to thermal expansion of the left end portion of the displacement portion 22 is set so as to be equal to the displacement amount of the ball screw 12.

The heat of the displacement portion 22 is hardly transferred to the mounting portion 23 by the heat insulating material 24. Therefore, the placing portion 23 itself hardly thermally expands, and the placing portion 23 translates leftward in the figure by the displacement amount of the left end portion of the displacement portion 22 due to the thermal expansion. In this way, even if the ball screw 12 is displaced due to thermal expansion, the mounting portion 23 is in the opposite direction to the displacement amount of the ball screw 12 by the same amount as the displacement amount of the ball screw 12 at the position where the screwing portion 21 is screwed. Therefore, the amount of displacement of the ball screw 12 due to thermal expansion can be almost canceled out. As a result, it is possible to accurately control the position of the mounting table even if the ball screw 12 thermally expands.

Further, in the present embodiment, unlike the case of electrically canceling the displacement amount, the touch sensor and the correction circuit are not required, and the configuration is simple and the cost does not increase.

Although the heat insulating material 18 is interposed in the present embodiment, this is not always necessary, and any structure may be used as long as it limits transfer of heat of the displacement portion 22 to the mounting portion 23.

[0013]

As described above, according to the present invention, it is possible to accurately control the position of the mounting table even if the drive shaft is thermally expanded with a simple structure and without increasing the cost.

[Brief description of drawings]

FIG. 1 is a perspective view showing an embodiment of a movable mounting table of the present invention.

FIG. 2 is a cross-sectional view of the movable mounting table of FIG.

FIG. 3 is a sectional view of a conventional movable mounting table.

[Explanation of symbols]

 11 Mounting Table 12 Ball Screw 16 Supporting Part 18 Heat Insulating Material 22 Displacement Part 23 Mounting Part

Claims (1)

[Scope of utility model registration request] 1. A drive shaft, one end of which is fixed so as not to be displaceable in the axial direction and the other end of which is displaceable in the axial direction by thermal expansion, and a mount which moves in the axial direction by rotation of the drive shaft around its axis. A mounting table is provided, and the mounting table includes a displacement portion that is screwed onto the drive shaft, a mounting portion that is connected to the displacement portion, and a heat insulating material that is disposed between the displacement portion and the mounting portion. The movable mounting table is characterized in that the mounting portion is thermally displaced in a direction opposite to the thermal expansion direction of the drive shaft.