JPH0337871Y2 - - Google Patents

Description

[Detailed description of the invention] a. Field of industrial application This invention relates to a device for moving a table in a machine tool, and more specifically, it is related to a device that moves a table in a machine tool, and more specifically, it improves accuracy without being affected by vibrations in the radial direction of a ball screw, etc. The present invention relates to a moving body actuating device that can perform good movement.

b. Prior Art Conventionally, as one of the devices for operating a movable body such as a table of a machine tool, a threaded rod such as a lead screw is rotated by an electric motor, and a nut member that is threadedly engaged with the screw is attached to the movable body to operate the movable body. A means of moving along a guide rail provided parallel to the lead screw is often used.

Many machine tool lead screws are long, and those that are supported at both ends by ball bearings can cause distortion near the center due to machining errors and unidirectional pressure. , there was an inconvenience that movement positioning was inaccurate due to backlash.

Recently, nut members have also been used that eliminate the back crush which applies preload such as holding a ball and pulling the middle point toward both ends by interposing a spacer between a pair of ball circulating nut members of the same size and shape. However, in this case as well, it was inevitable that the center of the long lead screw would bend.

c Problems to be solved by the invention As mentioned above, if the lead screw is deflected, vibrations in the radial direction will occur when the lead screw rotates, and this vibration will have a negative effect on the movement accuracy of the table. , there is a problem in improving the table movement accuracy.

d Means to solve the problem In order to solve the conventional problems as mentioned above,
In this invention, a nut member screwed onto a rotatably provided lead screw is connected to a sub-table that can freely reciprocate while being guided by a guide rail provided parallel to the lead screw. A flexible bar member with one end connected to the table is provided parallel to the lead screw, and the other end is connected to a movable table that is reciprocally movable in the same direction as the sub-table. .

e Effect In the above configuration, when the lead screw is rotated, the sub-table is moved via the nut member, and the moving table is moved via the bar member. When radial vibration occurs in the lead screw, it is transmitted to the sub-table via the nut member, but since the sub-table is guided by the guide rail, the vibration is suppressed. Since the vibration of the sub-table is absorbed by the flexibility of the bar member, it is not transmitted to the moving table, and the moving table can move with high precision without being affected by vibration. can be carried out.

f Example FIG. 1 shows a front view of a surface grinder 1 as an example machine implementing the present invention, and FIG. 2 shows a right side view thereof.

First, in Figure 2, the Y-axis drive motor 5 is located behind the base 3.
A lead screw 7 (see FIG. 1), which is driven forward and backward by the electric motor 5, is screwed into a nut member 9 of a ball circulation type.

This nut member 9 is connected to the mobile body actuating device 1 of the present invention.
One end of 1 is connected, and the other end is the Y-axis moving table 1.
3 are connected, and the Y-axis moving table 13 is guided by Y-axis guide rails 15, 15 and moves in the Y-axis direction on linear motion bearings 17, 17.

X-axis guide rails 19, 19 are provided on the Y-axis moving table 13, and the sub-table 23 moves along the X-axis guide rails 19, 19 via ball circulation type linear motion bearings 21, 21.
It is set up to straddle the

The center of the sub-table 23 is connected to the X-axis drive motor 25.
A lead screw 27 that is driven by the lead screw 27 passes through the sub-table 23, and a ball circulation type nut member 29 that is screwed into the lead screw 27 is fixed to the sub-table 23.

Above the sub-table 23 is the X-axis moving table 3.
1 is provided, and an electromagnetic adsorption stand 33 and the like are provided thereon, and reciprocate in the X-axis direction below the grinding wheel 35.

Figures 3 and 4 show an embodiment in which the device of the present invention is mounted on a moving table 31 in the X-axis direction.
Since the movable table 13 in the Y-axis direction has the same structure, a description thereof will be omitted.

The aforementioned X-axis drive motor 25 is attached to the side of the Y-axis moving table 13, and its output shaft 3
7, the lead screw 27 is rotated in forward and reverse directions via a timing belt 39.

A pair of ball circulation type nut members 29 of the same size and shape that are screwed together with this lead screw 27 are arranged with a spacer 41 to adjust the female thread spacing between the pair of nut members 29, 29 from, for example, the thread pitch of the lead screw 27. Keep it slightly larger.

In other words, a nut member 2 with a pair of circulating balls
9 and 29 are in contact with the outside of the thread groove (on the left and right sides in FIG. 1) and pull the lead screw 27 left and right at the spacer 41 position.

At the upper rear end of the sub-table 23 (the right end in FIG. 1), a septant-shaped flange portion 43 is provided at both ends.
A bar member 45 having a round bar shape in the middle and having a bar member 43 is fixed thereto, and a flange portion 43 of the bar member 45 is also fixed to the rear end of the X-axis moving table 31 via a bracket 47.

Note that the lead screw 27 is provided with a through hole 49 at its axial center through which grinding oil passes, to prevent heat generation due to repeated bending of the lead screw 27.

The machine tool movable body actuating device described in detail above is configured by connecting the rear end of the sub table and the rear end of the movable table with a bar member having flanges at both ends, so that the lead screw is Even if it rotates with strain in the axial direction, it will respond flexibly in the Z-axis direction and only transmit a slight strain in the X-axis direction.

As mentioned above, only the displacement based on a slight strain is transmitted to the table moving in the Y-axis direction, so overall the material to be ground is accurately moved and positioned, resulting in the effect of high-precision machining. It was.

g. Effects of the Invention As can be understood from the description of the embodiments above, the present invention basically consists of a nut member 29 screwed onto a rotatably provided lead screw 27.
is connected to a sub-table 23 that can freely reciprocate while being guided by a guide rail 19 provided parallel to the lead screw 27, and the sub-table 2
A flexible bar member 45 having one end connected to the lead screw 27 is provided in parallel with the lead screw 27, and the other end is connected to a movable table 31 provided so as to be able to reciprocate in the same direction as the sub-table 23. It is what it is.

As is clear from the above configuration, in the present invention, a movable table 31 and a sub-table 23 are provided, and the nut member 29 screwed onto the lead screw 27 is connected to the sub-table 23.
The sub-table 23 and the movable table 31 are connected via a flexible bar member 45 parallel to the lead screw 27.

Therefore, vibrations in the radial direction when the lead screw 27 rotates are transmitted to the sub-table 23 via the nut member 29, but as the sub-table 23 is guided and moved by the guide rail 19, Vibrations and the like of the lead screw 27 are regulated to some extent and suppressed.
The movement of the sub-table 23 is transmitted to the movable table 31 via the bar member 45, and the movable table 31 is moved.The bar member 45 is flexible, and one end thereof is connected to the sub-table. 23, the other end is connected to the movable table 31 and is parallel to the lead screw 27, so vibrations of the sub-table 23 are absorbed by the flexibility of the bar member 45, and the movement It is not transmitted to table 31. Then,
The moving table 31 is not affected by vibrations of the lead screw 27 and can be moved with high precision.

[Brief explanation of the drawing]

Figure 1 is a front view of a surface grinder as an example of the device of the present invention, Figure 2 is a side view of the same, and Figure 3 is a side view of the same.
The figure is an enlarged cross-sectional view of the movable body actuating device section, and FIG. 4 is a cross-sectional view taken along the arrow - in FIG. Explanation of symbols representing main parts of the drawings: 1...Surface grinder, 11...Moving body actuator, 13...Y-axis moving table, 23...Sub table, 27...
Lead screw, 29... Nut member, 31...
...X-axis moving table, 43...Flange section, 45
...Bar member.

Claims (1)

[Scope of utility model registration request] The nut member 29 screwed onto the rotatably provided lead screw 27 is inserted into the lead screw 2.
A flexible bar member 45 is provided connected to a sub-table 23 that can freely reciprocate while guided by a guide rail 19 provided in parallel with the lead screw 27 , and has one end connected to the sub-table 23 . The sub table 2 is provided in parallel and the other end is
3. A movable body actuating device for a machine tool, which is connected to a movable table 31 that is provided to be reciprocally movable in the same direction as 3.