JPS6216788B2 - - Google Patents

Description

DETAILED DESCRIPTION OF THE INVENTION The present invention relates to a multi-shaft cooling device for cooling bearings 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, 21 are main shafts, 3, 31 are bearings, 4, 41 are bearing stands, 5, 5
1 is a pulley 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 each of these figures, 7 and 71 are annular hollow chambers formed inside the bearing stands 4 and 41, and 8 and 81 are annular hollow chambers formed inside the bearing stands 4 and 41. It is a heat dissipation device and is cooled by cooling fans 9 and 91. 10 is a first communication pipe that communicates the hollow chamber 7 and the heat radiating device 8; 101 is the hollow chamber 71 and the heat radiating device 81;
12 is a third communication pipe that communicates between the heat radiator 8 and the second communication pipe 101 and has a flexible part 12 a that can be expanded and contracted, such as a bellows; 121 is a third communication pipe that communicates with the heat radiator 8 and the second communication pipe 101 ; and the first
A fourth communication pipe 13 communicates with the third communication pipe 12 and the fourth communication pipe 121 and has an expandable flexible portion 121a such as a bellows. This is a fifth communication pipe having an expandable and contractible flexible portion 13a.

In addition, the hollow chambers 7, 71 and the heat dissipation devices 8, 81,
After reducing the pressure inside the first and second communication pipes 10 and 101, the third and fourth communication pipes 12 and 121, and the fifth communication pipe 13, a predetermined amount of working liquid such as ammonia and fluorocarbon is added inside them. Enclosed.

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 vapor pressure is used to move to the heat radiator 8 through the first communication pipe 10 and to the heat radiator 8 through the second communication pipe 101, and are cooled by the surrounding air by the cooling fans 9, 91. 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 from the third and fourth communication pipes 12 and 121 to the second and first communication pipes 10.
1 and 10 and return to the hollow chambers 71 and 7 of the bearing stands 41 and 4 using gravity. By repeating such operations, the amount of heat in the bearing stands 4, 41 is transported to the heat radiating devices 8, 81, and the heat is efficiently cooled.

By the way, if the temperature rise (calorific value) of the bearing pedestal 4 is larger than that of the other bearing pedestal 41, the amount of vapor, vapor pressure, and vapor temperature during vaporization of the working liquid in the hollow chamber 7 of the bearing pedestal 4 will be higher than that of the other bearing pedestal 41. It becomes larger in comparison. Therefore,
A larger amount of latent heat of vaporization is taken away and the bearing pedestal 4 is cooled down to a greater extent, and the temperature rise of the bearing pedestal 4 causes the other bearing pedestal 41 to cool down.
It works to prevent it from getting bigger. The high temperature steam vaporized in the hollow chamber 7 of the bearing stand 4 moves to the heat radiator 8 via the first communication pipe 10, and the working liquid condensed in the heat radiator 8 is condensed in the heat radiator 81. The temperature is higher than that of the working fluid,
It flows from the third communication pipe 12 through the second communication pipe 101 into the hollow chamber 71 of the bearing stand 41 . Therefore, the bearing pedestal 41 is warmed by the higher temperature of the working fluid, increasing the temperature rise, and the difference in temperature rise between the two bearing pedestals 4, 41 is kept small. In addition, bearing stand 4
1 has a smaller temperature rise than bearing pedestal 4, and bearing pedestal 4
The working liquid in the hollow chamber 71 of the bearing base 4 has a lower vapor amount, vapor pressure, and vapor temperature when vaporized than the working liquid in the hollow chamber 7 of the bearing stand 4. Therefore, the second communication pipe 10
1. Heat dissipation device 81, fourth communication pipe 121 to first
A lower temperature working liquid flows in through the communication pipe 10 of the . As a result, the bearing stand 4 is cooled by the lower temperature of the working fluid, reducing the temperature rise.
The difference in temperature rise between both bearing stands 4 and 41 can be kept small. As such operations are repeated, the amount of working fluid in the hollow chamber 7 of the bearing pedestal 4 gradually decreases and the amount of working fluid in the hollow chamber 71 of the bearing pedestal 41 increases. As a result, a part of the working liquid that returns from the heat dissipation device 8 to the hollow chamber 71 of the bearing pedestal 41 via the third communication pipe 12 and the second communication pipe 101 can be returned to the hollow chamber 7 of the bearing pedestal 4. It works to maintain a predetermined amount of working fluid. 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. Also, the span P between the main shaft 2 and the main shaft 21 is
It can be made variable within the expansion and contraction range of the flexible portions 12a, 121a, 13a of the communicating tubes 12, 121 and the fifth communicating tube 13.

Although the above embodiment describes the case where the cooling fans 9, 91 are used, natural air cooling may be used without using the cooling fans 9, 91, or cooling water, oil, etc. other than the cooling air may be used as the cooling source. A similar effect can be obtained by using

Further, in the above embodiment, the flexible portion 12a,
Although the case where 121a 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 an annular hollow chamber formed inside a bearing part and filled with a working liquid, and a heat radiating device for radiating the heat of the bearing part, and a first part installed in the same machine. , a second spindle device, a first communication pipe that communicates the hollow chamber of the first spindle device with the heat dissipation device of the first spindle device, heat radiation between the hollow chamber of the second spindle device and the second spindle device a second communication pipe that communicates with the device; a third communication pipe that communicates between the heat dissipation device of the first spindle device and the second communication tube and has an expandable and contractible flexible portion; and a heat dissipation device of the second spindle device. a fourth communication pipe that communicates with the device and the first communication pipe and has a flexible part that can be expanded and contracted; a fifth communication pipe that communicates with the third communication pipe and the second liquid pipe and has a flexible part that can be expanded and contracted; By providing a communication pipe to transport the heat of the bearing from the hollow chamber to the heat dissipation device, the heat of the bearing can be quickly removed and cooled efficiently and evenly, reducing thermal deformation and distortion of the bearing. This has an extremely large practical effect in that it is possible to minimize the amount of heat generated and improve the machining accuracy of machine tools.

[Brief explanation of the drawing]

1 and 2 are cross-sectional side views showing a conventional multi-shaft cooling device, and FIGS. 3 and 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. In the figure, 1 and 11 are the first and second spindle devices, 4 and 41 are bearing stands, 7 and 71 are hollow chambers, 8,
81 is a heat dissipation device, 10 and 101 are first and second communication pipes, 12 and 121 are third and fourth communication pipes, 12
a and 121a are flexible parts, 13 is a fifth communicating pipe, and 13a is a flexible part. Note that the same reference numerals in the figures indicate the same or corresponding parts.

Claims (1)

[Scope of Claims] 1. An annular hollow chamber formed inside a bearing section and filled with a working liquid, and a heat radiating device for dissipating the heat of the bearing section, and a second device installed in the same machine. 1. a second spindle device, a first communication pipe that communicates the hollow chamber of the first spindle device with the heat dissipation device of the first spindle device, the hollow chamber of the second spindle device and the second main spindle device; a second communication pipe that communicates with the heat dissipation device of the main spindle device; a third communication pipe that communicates between the heat dissipation device of the first spindle device and an intermediate portion of the second communication pipe and that has an expandable and contractible flexible portion; tube,
a fourth communication pipe that communicates between the heat dissipation device of the second spindle device and the middle of the first communication pipe and has a flexible part that can be expanded and contracted; the third communication pipe and the fourth communication pipe; a fifth communication pipe having a flexible part that is expandable and retractable;
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 the evaporation and condensation action of the working 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.