JPH0355260B2 - - Google Patents

Description

DETAILED DESCRIPTION OF THE INVENTION The present invention relates to a method for positioning a sliding body in a machine tool, and is intended to provide a method for precisely positioning a sliding body having a large size and weight.

Machine tools are equipped with sliding bodies such as tables and tool stands, and these sliding bodies generally have a large weight, and their positional accuracy directly affects machining accuracy. In recent years, machining accuracy on the order of microns has come to be required even for large machine tools, and how to precisely position these sliding bodies has become an important issue. There is.

Generally, such a sliding body slides on a precisely machined slide bed, and is moved and positioned by a feeding mechanism using a ball screw, and the position of the sliding body is controlled by a linear scale, etc. There are also devices in practical use that perform feedback control based on detection. However, when the weight of the sliding body becomes large, stick slip occurs due to elastic deformation of the feeding mechanism, etc., making it impossible to move the sliding body on the order of microns. In other words, even if you try to move the sliding body several microns, the sliding body will move intermittently in units of about 10 microns due to the stick slip, making it completely impossible to precisely position the sliding body at the desired position. I'm getting used to it.

This invention was made for the purpose of positioning a sliding body having a large weight on the order of microns, and by adopting the method of the present invention for the tables and tool stands of machine tools, large workpieces can be moved with extremely high precision. It is made so that it can be processed.

A method for positioning a sliding body according to the present invention is to divide a sliding body such as a table or a tool stand into a main body and a sliding base, and to provide a positioning coupling that engages the two and a main body separation mechanism that engages and removes the coupling. , an auxiliary guide means is provided to hold the main body when the coupling ring is removed, coarse positioning is performed with the main body and the sliding base fitted together, and then sliding is performed with the coupling ring removed. Precise positioning of only the base is performed, and then the main body is fitted onto the sliding base using the coupling, thereby performing precise positioning of the main body. That is,
During precise positioning, the main body of the sliding body is separated to reduce the load acting on the feed mechanism, thereby preventing the occurrence of stake slip, and allowing the main body to fit into the sliding base positioned at an accurate position. This makes it possible to accurately position the main body at a desired position.

1 to 3 show an embodiment of a machine tool employing the method of the present invention, in which rotary tool heads 2, 2 are slidably mounted on a slide bed 1.
The method of the present invention is adopted as a positioning means.

In Figure 1, 3 is a base, 4 is a table,
The slide bed 1 is fixed to the base 1 parallel to the feeding direction of the table 4, and the rotary tool head 2,
2 is attached to this slide bed 1. Each rotary tool head 2 is divided into a main body 5 and a sliding table 6, and by moving the main body 5 in the axial direction of the tool 7 by a mechanism to be described later, the main body 5 can be moved at the position of the joint 8. and the sliding table 6 are fitted into and removed from each other.
Guide rods 9 and 10 are provided to hold the main bodies 5 and 5 when the fitting with the slide table 6 is released. Guide pin 11 or 1 implanted in 1
Both ends are fixedly attached to support frames 15 and 16 which are slidably provided on the base plate 4.

FIG. 2 is a longitudinal cross-sectional view of the rotary tool head 2.
18 is a tool holder, 18 is a main shaft, 19 is an electric motor for driving the main shaft, and 20 is a belt wound between the main shaft 18 and the output shaft of the electric motor 19. Reference numeral 21 denotes a carby coupling provided at the connecting portion 8 between the main body 5 and the sliding base 6, one of which 21a is fixed to the sliding base 6, and the other 21b is fixed to the main body 5. This coupler ring 21 is provided with a large number of radial meshing teeth on the coupling surface, and by fitting the meshing teeth, the main body 5 and the sliding table 6, which are formed separately, can be moved with extremely accurate positional accuracy. It can be mated with Reference numeral 22 denotes a hydraulic cylinder fixed to the slide table 6 for fitting and removing the coupling 21, and a rod 24 extending from the piston 23 is fixed to the main body 5.

FIG. 3 is a horizontal sectional view of the feed mechanism section of the rotary tool heads 2, 2, and shows the sliding base 6,
6 is slidably attached to the slide bed 1 and is screwed into a feed screw 25 which is disposed parallel to the bed 1 via ball nuts 26, 26. 27
is an electric motor that drives the feed screw 25, and 28 is a coupling. The feed screw 25 is pivotally supported at its center and both ends by brackets 29, 30, and 31 extending from the slide bed 1;
5a is provided with a right-hand thread, and the other 25b is provided with a left-hand thread, so that when the feed screw 25 is rotated, the rotary tool heads 2, 2 move away from each other.
That is, the tool heads 2, 2 are configured to move symmetrically with respect to their centers.

In the above configuration, the procedure for precisely positioning the rotary tool head 2 will be explained below. Pressure oil is supplied to the rod end side of the hydraulic cylinder 22, and the main body 5 is attracted to the sliding table 6 side and the coupling ring 21 is fitted, that is, the main body 5 and the sliding table 6 are integrated. In this state, the rotary tool head 2 is roughly positioned by rotating the electric motor 27. The positioning accuracy at this time is about 10 microns, as described above. After rough positioning is performed, the electric motor 27 is stopped, pressure oil is supplied to the head end side of the hydraulic cylinder 22, the coupling 21 is disengaged, and the main body 5 and the sliding body 6 are disengaged. At this time, the separated main body 5 is held by guide rods 9 and 10. Next, the electric motor 27 is rotated, but at this time, the only resistance acting on the feed mechanism such as the feed screw 25 and coupling 28 is the resistance based on the weight of the slide table 6, and the load acting on the feed mechanism is reduced. The moving table 6 can be positioned with accuracy on the order of microns. Even when the main body 5 is separated from the sliding table 6, the main body 5 and the sliding table 6 are connected via the rod 24 of the cylinder 22, but the amount of movement of the sliding table 6 is extremely small. , the main body 5 is held by the rods 9 and 10 and remains stopped. Once the precise positioning of the slide table 6 is completed,
Pressure oil is supplied to the rod end side of the hydraulic cylinder 22, the coupling 21 engages with the main body 5, and the main body 5 is fitted and positioned on the precisely positioned slide table 6.

As explained above, according to the method of the present invention, it is possible to precisely position a sliding body having a large weight on the order of microns, and it is possible to perform highly accurate machining even with a large machine tool.

[Brief explanation of drawings]

The figures show an embodiment of a machine tool employing the method of the present invention, in which Fig. 1 is a perspective view, Fig. 2 is a longitudinal sectional view of the tool head, and Fig. 3 is a horizontal sectional view of the head feeding mechanism. be. In the figure, 1 is a slide bed, 2 is a rotary tool head, 5 is the main body of the rotary tool head, 6 is a sliding base of the rotary tool head, 8 is a joint, 9 and 10 are guide rods, and 11 to 14 are guide pins. 15 and 16 are support frames, 21 is a carboxylic coupling, 22 is a hydraulic cylinder, 23 is a piston, 24 is a rod, 2
5 is a feed screw, 26 is a ball nut, and 27 is an electric motor.

Claims (1)

[Claims] 1 The sliding body is divided into a sliding base and a main body, and a positioning coupling is provided for fitting the two together, and a main body separation mechanism is provided for fitting and removing the coupling, and an auxiliary member is provided for holding the main body when the coupling is separated. A guide means is provided, and rough positioning is performed with the main body and the sliding base fitted together, then precise positioning of only the sliding base is performed with the coupling ring removed, and then the main body is placed on the sliding base. A method for precisely positioning a sliding body in a machine tool, the method comprising: performing precise positioning of a main body by fitting the body with the coupling ring.