JPS61226246A - Machine tool with heat displacement preventer - Google Patents

Abstract

PURPOSE:To reduce a temperature difference between the spindle head side and the opposite side as well as to prevent heat displacement from occurring, by installing plural temperature detectors at the side of a sliding surface of a column having a spindle head, for example, being slidably attached to, and likewise a lot of temperature detectors of the same number at the opposite side. CONSTITUTION:A position of a spindle head H is detected by position detectors 1LS-5LS (unillustrated herein) attached to a column C, while temperature in a part, where the spindle head H is situated, is detected by temperature detectors 1F-5F attached to a sliding surface and temperature detectors 1B-5B attached to the opposite side and compared with a temperature comparator. When temperature at the side of the spindle head H becomes higher than the opposite side, a signal is emitted out of the temperature comparator whereby heaters 1H-5H attached to the opposite side of a part, where the spindle head H is situated, are turn to ON, and this comparing signal is kept up till temperature becomes almost equalized. In consequence, the column C is maintained in a state of being thermally balanced so that heat displacement is preventable.

Description

[Detailed description of the invention] [Technical field of invention] The present invention relates to a machine tool with a thermal displacement prevention device.

[Technical background of the invention and its problems]

In machine tools equipped with a sliding body, such as a spindle head, that slides back and forth along a sliding surface, and a support, such as a column, on which the sliding surface of the sliding body is formed, the spindle head, on which the sliding surface side of the column slides, It is heated by a heat source such as the temperature of the lubricating oil on the spindle head, causing thermal deformation. The amount of thermal deformation increases as the spindle head becomes larger and the operation speed increases.
After using the machine tool for a long time, it becomes a value that cannot be ignored in terms of machining accuracy. In recent years, as machine tools have become larger and faster, unmanned operation has progressed, and there is a demand for machine tools that do not cause thermal displacement in the column even when used for long periods of time.

[Failure to solve the problem]

The present invention has been made in consideration of these points,
In a machine tool equipped with a sliding body that reciprocates along a sliding surface and a support body on which a sliding surface of the sliding body is formed, the sliding surface side of the support body is provided with a support body that extends in the sliding direction of the sliding body. To provide a machine tool with a thermal displacement prevention device, in which a plurality of temperature detectors are attached, and the same number of heaters and the same number of temperature detectors as the temperature detectors are arranged on a surface opposite to the sliding surface. With the goal.

[For production]

A temperature comparator compares the temperatures of the temperature detector attached to the sliding surface side of the support body corresponding to the sliding position of the sliding body and the temperature detector attached to the surface opposite to the sliding surface side. However, when the temperature on the sliding surface side becomes higher than the temperature on the opposite side to the sliding surface side, a signal is emitted from the temperature comparator, and the heater corresponding to the sliding position of the sliding body is heated by the signal,
This state is maintained until the temperatures of the sliding surface and the opposite surface become almost the same. Normally, the temperature of the surface of the support opposite to the sliding surface tends to be equal to or lower than the temperature of the sliding surface.

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

FIG. 1 is a block diagram of a control circuit according to the present invention, and FIG. 2 is a schematic perspective view showing an example in which the present invention is applied to a width boring machine. A temperature sensor, such as a thermistor IF to 5F, is attached to the sliding surface side of the support, for example, column C, and a thermistor IB to 5B and a heater, such as a heater, are attached to the side surface of column C, that is, the surface opposite to the sliding surface side of column C. IH to 5H are attached and the outside is covered with heat insulating material W.

Next, the operation of the present invention having such a configuration will be explained. A position detector for the spindle head H, such as limit switches IL8-5LS (not shown in Fig. 2), is attached to the column C, and the limit switch is activated according to the position of the spindle head H, and the position of the spindle head is detected. Thermistor IF in the part where
~5F and the thermistor IB ~5B placed on the opposite side position are compared with a temperature comparator, and the temperature of column C is compared.
When the temperature on the sliding surface side of the spindle head H, that is, the surface that receives heat conduction, becomes higher than the temperature on the opposite side, a signal is emitted from the temperature comparator, and the It is heated by a heater attached to the side surface, and this state is maintained until the temperatures on the sliding surface side and the side surface of the column C become approximately equal.

In FIG. 3, among the heaters IH to 5H, a portion of the heater 3H that is filled in black is energized. To explain this with reference to FIGS. 1A and 1B, the limit switch 3LS for detecting the position of the spindle head H is
When it is turned on, the auxiliary relay 3R is turned on. When the auxiliary relay 3R is turned ON, the temperatures of the thermistor 3F attached to the sliding surface side of column C and the thermistor 3B attached to the side surface side are compared by a temperature comparator, and
A signal is emitted when the temperature on the sliding surface side is higher than the temperature on the side surface side. When the temperature comparator issues a signal, the auxiliary relay 3R is turned on, so the auxiliary relay 3K is turned on, and when the auxiliary relay 3K is turned on, the heater 3H is turned on.
heating. The state in which the temperature comparator outputs a signal is maintained until the temperature on the sliding surface side of column C becomes approximately equal to the temperature on the side surface side. As a result, a thermally balanced state is always maintained between the sliding surface side and the opposite surface side of the column C, and no thermal displacement occurs in the column C even after long-term use.

FIG. 4 is a schematic diagram showing a conventional example, and shows that if column C is not thermally balanced, column C will undergo thermal displacement.

FIG. 5 is a block diagram showing a second embodiment of the present invention. According to this embodiment, the arrangement of the temperature detector and the heater is the same as that shown in FIG.

In the second embodiment, a limit switch for detecting the position of the spindle head H is not installed, and instead, the same number of temperature comparators as thermistors are installed on the sliding surface side to constantly measure the temperature of the sliding surface side and the opposite surface side. When the temperature on the sliding surface side becomes higher than the temperature on the opposite surface side, the temperature comparator generates a signal regardless of the position of the spindle head H, and the corresponding heater heats the sliding surface side and the back surface side. This state is maintained until the temperatures of both become almost the same.

Furthermore, in the embodiments of the present invention, a cross-boring machine equipped with a spindle head as a sliding body and a column as a support body has been described, but in addition to this, a planing machine equipped with a cross rail as a support body,
Similar effects can be obtained with machine tools such as plano mirrors.

〔Effect of the invention〕

As explained above, according to the present invention, it is possible to effectively prevent thermal displacement of a machine tool equipped with a sliding body that slides on the sliding surface of a support, and it is possible to perform high-precision machining even during long-time operation. ability can be maintained.

[Brief explanation of drawings]

Fig. 1 is a block diagram showing an embodiment of the present invention, Fig. 2 is a schematic perspective view showing an example in which the invention is applied to a width boring machine, and Fig. 3 is a block diagram showing an embodiment of the present invention.
The drawings are a schematic front view of FIG. 2, FIG. 4 is a schematic front view showing a conventional example, and FIG. 5 is a block diagram showing a second embodiment of the present invention. 1F to 5F, IB to 5B...Thermistor for temperature detection, IH to 5H... Heater for heating, C...
...-Column, H...Spindle head Fig. 1 A Fig. 1 B Fig. 2 IF ~ 5F ----Boo ξ Suff old ~ 5B------ Pumi Xri old ~ 5H- ---W-Ta C--------1--Column H--1-----Main M3 Sea Figure 3 Figure 4 Figure 5 A Figure 5 B

Claims (1)

[Claims] 1. A machine tool equipped with a sliding body having a heat source capable of reciprocally sliding along a sliding surface, and a support on which a sliding surface of the sliding body is formed. Multiple temperature detectors are installed on the sliding surface side in the sliding direction of the sliding body.
A machine tool with a thermal displacement prevention device, characterized in that the same number of heaters and the same number of temperature detectors as the temperature detectors on the sliding surface side are disposed on the surface of the support opposite to the sliding surface. . 2. A machine tool with a thermal displacement prevention device according to claim 1, wherein the support body is a column, and the sliding body is a spindle head slidably mounted on the column. 3. A machine tool with a thermal displacement prevention device according to claim 1, wherein the temperature detector is a thermistor and the heater is a heater.