JPS6214384B2 - - Google Patents

Description

DETAILED DESCRIPTION OF THE INVENTION The present invention relates to a multi-shaft cooling device that cools bearing parts such as a plurality of main shafts of a machine tool, for example.

Conventionally, there have been devices of this type as shown in FIGS. 1 and 2. In each of these figures, 1, 1
Reference numeral 1 denotes first and second spindle devices of the machine tool, which are arranged at an interval of span P. 2 and 21 are main shafts 3 and 31 are bearings, 4 and 41 are bearing stands, 5 and 51 are pulleys, and 6 is a bed.

Next, the operation will be explained. The main shafts 2, 21 are rotated by the rotational force transmitted to the pulleys 5, 51 via the V-belt by a driving electric motor (not shown). At this time, the bearings 3, 31 located between the main shafts 2, 21 and the bearing stands 4, 41 have the purpose of helping the main shafts 2, 21 rotate smoothly.
As the bearings 3 and 31 rotate, they generate heat due to friction and their temperature increases. The amount of heat generated in the bearings 3, 31 is transmitted to the bearing stands 4, 41, and is transferred to the bed 6 and the surrounding air to radiate heat. At this time, the temperature of the bearing stands 4 and 41 increases, and various thermal deformations and strains occur in each part due to thermal expansion. For this reason, the positions of the main shafts 2 and 21 fluctuate,
There was a drawback that the machining accuracy decreased when machining the workpiece. Furthermore, there is a drawback that there is a difference in the fluctuation of the positions of the main shafts 2 and 21 between them, and at the same time, there is a difference in the machining accuracy when performing a plurality of machining operations.

This invention was made in order to eliminate the drawbacks of the conventional ones as described above, and an object of the present invention is to provide a multi-shaft cooling device that can effectively and evenly cool the first and second main shaft devices. It is an object.

An embodiment of the present invention will be described below with reference to FIGS. 3 and 4. Fig. 3 is a block diagram showing the functional system, and Fig. 4 is a cross-sectional side view. In these figures, 7 and 71 are annular hollow chambers formed inside the bearing stands 4 and 41, and 8 is a heat dissipation device. and
It is cooled by a cooling fan 9. Reference numeral 10 denotes a steam pipe that guides the vapor of the working liquid vaporized in the hollow chambers 7 and 71, respectively, to join the heat dissipation device 8, and has a flexible part 10d that can be expanded and contracted, such as a bellows. It is composed of a pipe 10c. Reference numeral 12 denotes a flexible part 12a that divides and guides the working liquid that is condensed and liquefied by the heat dissipation device 8 into the hollow chambers 7, 71 of the bearing stands 4, 41, and is also extendable and retractable, such as a bellows.
It is a liquid pipe having a confluence pipe 12a and a branch pipe 12.
b, 12c. 13 is liquid pipe 1
A flexible part 13 that connects the two branch pipes 12b and 12c and is expandable and retractable, such as a bellows.
It is a communicating pipe having a.

After the hollow chambers 7 and 71, the heat radiating device 8, the steam pipe 10, and the liquid pipe 12 are vacuumed, a predetermined amount of a working liquid such as ammonia or chlorofluorocarbon is sealed therein.

Next, the operation will be explained. The heat of the bearings 3, 31 received by the bearing stands 4, 41 is taken away as latent heat of vaporization when the working liquid such as fluorocarbons in the hollow chambers 7, 71 is heated and vaporized, and the vapor of the vaporized fluorocarbons is The branch pipe 1 of the steam pipe 10 is created using steam pressure.
0a, 10b is transferred to the heat radiating device 8 via the confluence pipe 10c, and is cooled by the surrounding air by the cooling fan 9. At this time, the vapor of fluorocarbon or the like is condensed and returned to liquid, but the latent heat of condensation is released to the surrounding air, and the amount of heat from the bearings 3 and 31 is radiated to the surrounding air. The condensed working liquid flows through the confluence pipe 12a and branch pipe 12 of the liquid pipe 12.
b, 12c, bearing stands 4, 41 using gravity.
Return to hollow chambers 7 and 71. By repeating such operations, the amount of heat in the bearing stands 4, 41 is transported to the heat radiating device 8 and efficiently cooled.

By the way, when the temperature rise (heat amount) of the bearing joint 4 is larger than that of the other bearing pedestal 41, the working liquid in the hollow chamber 7 of the bearing pedestal 4 becomes the working liquid in the hollow chamber 71 of the bearing pedestal 41 when vaporized. Compared to this, the amount of steam, pressure, and temperature are greater. Therefore, as the amount of steam becomes larger, the latent heat of vaporization is taken away to a greater extent, and the temperature of the bearing pedestal 4 increases.
It works to prevent it from becoming larger than 1. The high temperature steam vaporized in the hollow chamber 7 of the bearing stand 4 is then transferred to the branch pipe 10a of the steam pipe 10 and the confluence pipe 10c.
The liquid then moves to the heat dissipation device 8 where it is condensed and liquefied. On the other hand, the temperature rise of the bearing pedestal 41 is smaller than that of the bearing pedestal 4, and the working liquid in the hollow chamber 71 of the bearing pedestal 41 has a vapor amount and vapor pressure when vaporized compared to the working liquid in the hollow chamber 7 of the bearing pedestal 4.・Steam temperature is low. Therefore, the low-temperature steam vaporized in the hollow chamber 71 of the bearing stand 41 moves to the heat dissipation device 8 via the branch pipe 10a and the confluence pipe 10c of the steam pipe 10, and is condensed and liquefied.

However, high temperature steam has a high temperature when condensed and liquefied, and low temperature steam has a low temperature when condensed and liquefied. Therefore, in the heat dissipation device 8, high temperature steam and low temperature steam are mixed by the merging pipe 10c to produce steam at an average temperature.
The condensed and liquefied working liquid also becomes a working liquid with an averaged temperature. The working liquid at this averaged temperature returns to the hollow chambers 7, 71 of the bearing stands 4, 41 through the confluence pipe 12a and the branch pipes 12b, 12c of the liquid pipe 12, respectively. That is, the working fluid at a lower temperature returns to the hollow chamber 7 of the bearing pedestal 4, is cooled by the lowered temperature, and the temperature rise of the bearing pedestal 4 is reduced.
The working fluid at a higher temperature returns to the hollow chamber 71 of 1, and the bearing base 4 is heated by the increased temperature.
1 increases, and the difference in temperature rise between both bearing stands 4 and 41 is kept small. As such operations are repeated, the amount of working fluid in the hollow chamber 7 on the bearing pedestal 4 side gradually decreases and the amount of working fluid in the hollow chamber 71 on the bearing pedestal 41 side increases.
3 from the heat dissipation device 8 to the hollow chamber 7 on the bearing stand 41 side.
A part of the working liquid that returns to the bearing base 1 can be returned to the hollow chamber 7 on the side of the bearing stand 4, and serves to keep the amounts of both working liquids at a predetermined level. By repeating such an operation, when the heat generation amount and temperature rise of either of the bearing stands 4, 41 starts to increase, it works to suppress the difference in temperature rise of both the bearing stands 4, 41 to a small value, The bearing stands 4, 41 are effectively cooled evenly. Therefore, in the machine tool, thermal deformation and distortion of the bearing portion can be minimized, and machining accuracy can be improved. Further, the span P between the main shaft 2 and the main shaft 21 can be made variable within the expansion/contraction range of the flexible section 10d of the steam pipe 10, the flexible section 12d of the liquid pipe 12, and the flexible section 13a of the communication pipe 13.

In the above embodiment, the case where the cooling fan 9 is used has been described, but the cooling fan 9 may not be used and natural air cooling may be used, or cooling water or oil other than the cooling air may be used as the cooling source. The effect of this can be obtained.

Furthermore, in the above embodiment, a configuration was described in which the vapor of the working liquid is merged outside the heat radiating device 8 and the condensed working liquid is separated, but the vapor of the working liquid is merged inside the heat radiating device 8, A structure may be adopted in which the condensed and liquefied working liquid is divided, and the same effects as in the above embodiment can be achieved.

Further, in the above embodiment, the flexible portion 10d,
Although the case where 12d and 13a are constituted by bellows has been described, a flexible part which can be expanded and contracted may be constituted by something other than bellows.

Further, in the above embodiment, the hollow chambers 7 and 71 are provided in the bearing pedestals 4 and 41, respectively. You can also do this.

Incidentally, in the above description, the case where there are two spindle devices has been described, but the present invention can also be applied to a case where there are three or more spindle devices, and the same effects as in the above embodiment can be obtained.

As explained above, this invention has annular hollow chambers formed inside the bearing part and filled with working fluid, and the first and second bearings are mounted on the same machine.
a main shaft device, a heat radiating device for dissipating the heat of the first and second main shaft devices, and a heat radiating device for guiding the vapor of the working liquid that is vaporized in the hollow chambers of the first and second main shaft devices by merging with the heat radiating device. A steam pipe having a flexible part that can be expanded and contracted; By providing a communication pipe that communicates both branch parts and has a flexible part that can be expanded and contracted, and transporting the heat of the bearing part from the hollow chamber to the heat dissipation device, the heat of the bearing part can be quickly removed and efficiently. Since it can be cooled evenly,
This has an extremely large practical effect in that it can minimize thermal deformation and distortion of the bearing part and improve the machining accuracy of machine tools.

[Brief explanation of the drawing]

1 and 2 are a cross-sectional side view and a front view showing a conventional multi-shaft cooling device, and FIG. 3 and FIG. 4 are a block diagram and a cross-sectional side view showing a multi-shaft cooling device according to an embodiment of the present invention. It is. In the figure, 1 and 11 are the first and second main shaft devices, 4 and 41 are bearing stands, 7 and 71 are hollow chambers, 8 is a heat dissipation device, 10 is a steam pipe, 10a and 10b are branch pipes, and 10c is a confluence pipe. pipe, 10d is a flexible part,
12 is a liquid pipe, 12a is a confluence pipe, 12b and 12c are branch pipes, 12d is a flexible section, 13 is a communication pipe, and 13a is a flexible section. Note that the same reference numerals in the figures indicate the same or corresponding parts.

Claims (1)

[Scope of Claims] 1. First and second spindle devices each having an annular hollow chamber formed inside a bearing portion and filled with a working liquid, and mounted on the same machine, and the first spindle device described above. a heat dissipation device that dissipates a heat amount of
A steam pipe having a flexible part that can be expanded and contracted so that the vapor of the working liquid that is vaporized in the hollow chamber of the main shaft device is merged into the heat radiating device and guided, and the working liquid that is condensed and liquefied in the heat radiating device is
A liquid pipe that divides and guides the flow into the hollow chamber of the second main shaft device and has a flexible part that can be expanded and contracted, and a communication pipe that communicates both branched parts of the liquid pipe and has a flexible part that can be expanded and contracted, A multi-shaft cooling device characterized in that heat in the bearing portion is transported from the hollow chamber to the heat radiating device by evaporation and condensation of liquid. 2. The multi-axis cooling device according to claim 1, wherein the hollow chamber is formed in a bearing stand. 3. The multi-shaft cooling device according to claim 1, wherein the hollow chamber is formed between the bearing stand and the bearing. 4. The multi-axis cooling device according to any one of claims 1 to 3, characterized in that the flexible portion is constituted by a bellows.