JPS63191538A - Minute driving mechanism for fine working machinery - Google Patents

Abstract

PURPOSE:To permit the minute drive with high precision, suppressing the influences of a variety of external disturbance, the nonlinear characteristic, etc., by directly taking out the back pressure of a nozzle flapper into a pressure chamber and driving a positioned object through an elastic deformation plate by the taken-out differential pressure. CONSTITUTION:When the torque motors 7 and 8 of a servo-valve 3 are applied with electric current, a flapper 6 shifts in proportion to the electric current, and the gap between the flapper 6 and the right and left nozzles 4 and 5 varies. Therefore, the back pressure of the nozzle is introduced into the right and left pressure chambers 12 and 13 of a driving mechanism, and the differential pressure acts onto the elastic deformation plates 10a and 10b, and the rods 11a-11c are shifted, and the minute shift derive of a positioned object 2 is controlled according to the electric current supplied into the torque motors 7 and 8. Therefore, the influences of a variety of external disturbance, nonlinear characteristic, etc., are reduced, and the minute drive with high precision is permitted.

Description

DETAILED DESCRIPTION OF THE INVENTION (Field of Industrial Application) The present invention relates to a micro-drive mechanism for a precision processing machine such as a surface grinder for the purpose of ultra-precision processing on the submicron order.

(Prior Art) Most conventional micro-drive systems have been systems that combine piezoelectric elements or electromagnets with elastic mechanisms. However, these mechanisms are limited to systems with small loads;
There are many problems with drive mechanisms for machine tools that require large outputs, and therefore, in this field, systems have been limited to systems that use ball screws, hydraulic cylinders, etc. 6 However, such systems have problems in terms of accuracy and responsiveness. This was a technical barrier.

(Problems and Objects to be Solved by the Invention) High-precision positioning technology on the submicron order is required for feed mechanisms of ultra-precision processing machines, X-Y tables in semiconductor manufacturing equipment such as steppers, and the like. The present invention
The present invention aims to provide a minute drive mechanism that can perform such positioning with a very simple mechanism.

(Solution by invention) With a flapper placed between the opposing nozzles.

A servo valve consisting of a pair of torque motors sandwiching the flapper, three structures, an elastically deformable plate sandwiched between each structure, and a servo valve fixed to the elastically deformable plate and arranged concentrically with the three structures. The structure on one side is fixed to a structure such as a machine tool, the rod on the other side is fixed to an object to be positioned, and the structure, an elastic deformation plate, and a central rod are fixed to each other. The pressure chamber formed by the pressure chamber is connected to the pressure source of the nozzle.

(Example) An explanation will be given based on FIG. 1. Reference numeral 1 indicates a machine tool main body, and 2 indicates a positioning object, such as a cutting tool head of the machine tool. A is a micro drive mechanism according to the present invention, which is installed between the machine tool body 1 and the positioning object 2.

The micro drive mechanism A is a drive mechanism based on the principle of elastic deformation of a machine by fluid pressure, and consists of a servo valve that controls fluid pressure and a main body that converts fluid pressure into displacement using mechanical elasticity. It is configured.

The detailed structure of the minute drive mechanism A will be described below. 1st
The part 3 surrounded by the dotted line in the figure is a nozzle/flapper type one-stage servo valve, which is composed of a pair of opposing nozzles 4.5, a flapper 6, and a torque motor 7.8 sandwiching the flapper 6.

The main body of the micro drive mechanism A consists of three structures 9a and 9b.
, 9c and a pair of elastic deformation plays) 10a, 1
0b and the rod ll fixed to this elastic deformation plate
It consists of a, llb, and llc. 12 is a pressure chamber surrounded by rod lla, structure 9a, and elastically deformable plate 10a, and 13 is a pressure chamber similarly surrounded by rod llb, structure 9b, and elastically deformable plate 10b. The nozzle flapper pressure Ps of the servo valve 3 is supplied to these pressure chambers 12,13. 14 is left and right pressure chamber 12.13
This is a seal that prevents oil from leaking inside.

A structure 9a that constitutes a minute drive mechanism A in the machine tool body 1
However, a rod llb is also fixed to the positioning object 2. In addition, in the opposite case, the machine tool main body 1 and the rod, or the positioning object and the structure may be fixed.

(Operation) In FIG. 1, when a current is applied to the torque motor 7.8 of the servo valve 3, the flapper 6 is displaced in proportion to the current, and the gap between the left and right nozzles 4, 5 and the flapper 6 changes.

Through this operation, the fluid supplied to the servo valve 3 generates pressure at the nozzle flapper 6, and this nozzle flapper back pressure (left and right) is guided to the left and right pressure chambers 12 and 13 of the drive mechanism, respectively. The fluid pressure generated in the left and right pressure chambers 12.13 is caused by the left and right elastic deformation plates lOa, 1
Transform 0b. At this time, both elastically deformable plates 10a
, 10b are fastened by rods lla, llb, llc, so the rods 11a, llb, llc are displaced in proportion to the pressure difference between the left and right pressure chambers 12.13. Based on the above principle, the position of the positioning object 2 is controlled by the current flowing through the torque motor 7.8.

(Application Example 1) FIG. 2 shows an example in which one micro-drive mechanism A is installed between the vertical shaft body 21 and the main shaft portion 22 of a surface grinder.

Reference numeral 15 denotes a grindstone for grinding the workpiece W, and is driven by a main shaft motor 16. 17 is a motor for the left-right axis coarse movement mechanism;
Similarly, 18 is a ball screw. Reference numeral 19 is a motor for coarse movement of the shaft in the vertical direction, and reference numeral 20 is a ball screw. One micro-drive mechanism A can realize linear micro-movement in the Z-axis direction.

(Application Example 2) FIG. 3 shows an example in which three micro-drive mechanisms A are used in a surface grinder. Since the three minute drive mechanisms A are arranged so that each is located at the vertex of a triangle when viewed in a plane, it is possible to realize rotational fine movement around the χ axis and linear fine movement in the Z-axis direction.

(Effects) 1) Since the back pressure of the nozzle flapper is directly taken out to the pressure chamber and the differential pressure is used to drive the nozzle flapper through an elastically deformable plate, the influence of various disturbances, nonlinearity, etc. is reduced, and highly accurate driving is possible.

2) Since it is controlled by pressure, there is no need for large flow rate fluid control, and high-speed response is possible.

3) Since it is a drive method that utilizes mechanical elastic deformation, there are few factors that degrade accuracy such as play and backlash, and high precision drive is possible.

4) When used alone, it can drive in only one direction, but it has the advantage that a drive mechanism with any degree of freedom can be realized by combining and configuring it.

5) As mentioned above, since high-precision adjustment is possible with a simple configuration, precision machinery that requires high power such as machine tools,
The range of applications is wide, including drive mechanisms for semiconductor manufacturing equipment such as steppers.

[Brief explanation of the drawing]

FIG. 1 is a sectional view of a micro-drive mechanism according to the present invention. Figure 2 shows an example in which one minute drive mechanism A is applied to minute positioning of a grinding wheel head. FIG. 3 shows an example in which three minute drive mechanisms A are also used. In the figure; 1 machine tool body 2 positioning object 3 servo valve 4, 5 nozzle 6 flapper 7,
8 Torque motors 9a, 9b, 9c Structure 10a, Job Elastic deformation plate 11a, llb, llc Rod 12.13 Pressure chamber 14 Seal 15 Grinding wheel 16 Main shaft motor 17 Motor 18 Ball screw
19 Motor 20 Ball screw 21
Vertical shaft body 22 Main shaft part and above Applicant Sumitomo Heavy Industries, Ltd. Sub-agent Patent attorney Ohashi Younger brother Figure 1 A body/1 Motive section Figure 2

Claims (1)

[Claims] A servo valve consisting of a flapper disposed between opposing nozzles and a pair of torque motors sandwiching the flapper;
It consists of three structures, an elastically deformable plate sandwiched between each structure, and three rods fixed to the elastically deformable plates and arranged concentrically with the three structures. is fixed to a structure such as a machine tool, and the rod on the other side is fixed to a positioning object, and a pressure chamber formed by the structure, the elastic deformation plate, and the central rod is communicated with the pressure source of the nozzle. A micro-drive mechanism for precision processing machines characterized by the following.