JP3749442B2 - Machine tool spindle end seal structure - Google Patents

Description

[0001]
BACKGROUND OF THE INVENTION
The present invention relates to a structure for sealing a tip end portion of a main shaft in a machine tool.
[0002]
[Prior art]
For example, in a vertical machining center, a spindle end seal structure as shown in FIG. 3 is conventionally known. In this seal structure, a labyrinth 55 is formed by a seal member 52 on the main shaft 51 side and a seal member 54 on the main shaft head 53 side, and the end surfaces of the seal members 52 and 54 are covered by a lid member 56 via a slit 57, The labyrinth 55 and the lid member 56 are configured to prevent foreign matter such as cutting fluid and chips from entering, and to protect the spindle bearing 58 on the distal end side.
[0003]
[Problems to be solved by the invention]
However, according to the conventional seal structure, once the foreign matter enters the slit 57 or the labyrinth 55, it stays there and is not discharged to the outside. There was a problem.
[0004]
Accordingly, an object of the present invention is to provide a spindle end seal structure of a machine tool that can discharge an invading foreign substance to the outside and exhibit an excellent sealing function for a long time.
[0005]
[Means for Solving the Problems]
In order to solve the above-mentioned problem, the spindle end seal structure according to the invention of claim 1 has an inner seal member fitted to the outer periphery of the tip end portion of the spindle, and an outer seal member fitted to the inner periphery of the tip portion of the spindle head. A labyrinth is formed between each seal member, the end surface of each seal member is covered with a lid member via a narrow gap, a first drain hole is provided on the outer periphery of the lid member, and a second drain hole is provided on the outer seal member. On the other hand , the cover member is provided with a backflow prevention cover that projects outward from the outlet of the second drain hole, and a plurality of small holes for discharging foreign matter from the second drain hole are formed in the cover. Further, the present invention is characterized in that the foreign matter that has entered the slit and the labyrinth is discharged to the outside through the first and second drain holes by the rotation of the main shaft.
[0007]
DETAILED DESCRIPTION OF THE INVENTION
Hereinafter, embodiments of the present invention will be described with reference to the drawings. FIG. 1 and FIG. 2 show a seal structure at the tip of the main shaft of a vertical machining center. The spindle 1 is rotatably supported by a bearing 3 inside the spindle head 2. An inner seal member 4 is fitted on the outer periphery of the front end portion of the main shaft 1, and a pair of outer seal members 5, 5 ′ are fitted on the inner periphery of the front end portion of the main shaft head 2. A labyrinth 6 is formed between the two.
[0008]
A lid member 7 is attached to the outer seal member 5, and the end surfaces of the seal members 4, 5 are covered by the lid member 7 via the slits 8. A plurality of first drain holes 9 are provided on the outer periphery of the lid member 7, and a pair of second drain holes 10 are formed in the outer seal member 5 in an oblique shape. And it is comprised so that foreign materials, such as the cutting fluid and the chip which penetrate | invaded the slit 8 and the labyrinth 6, may be discharged | emitted from the drain holes 9 and 10 outside by rotation of the main axis | shaft 1. FIG.
[0009]
Two lids 11 for preventing backflow are fixed to the lid member 7 so as to protrude outward from the outlet of the second drain hole 10. A large number of small holes 12 (see FIG. 2) for discharging foreign matter from the second drain hole 10 are formed on the end surface and side surface of the cover 11. The outer seal member 5 is provided with a connection port 14 for the air purge pipe 13 that can be opened and closed by a plug 15, and an insertion hole 16 for the air purge pipe 13 is formed in the spindle head 2.
[0010]
The spindle head 2 is provided with a nozzle 17 that ejects cutting fluid toward the machining point and a passage 18 that supplies the cutting fluid to the nozzle 17. The outer seal member 5 of this embodiment also functions as a presser for the bearing 3.
[0011]
According to the main shaft end seal structure of the above configuration, the foreign matter that has entered the narrow gap 8 through the gap between the main shaft 1 and the lid member 7 is discharged to the outside through the first drain hole 9 by the rotation of the main shaft 1. The foreign matter that has entered the labyrinth 6 passes through the second drain hole 10 by the rotation of the main shaft 1 and is discharged to the outside from the small hole 12 of the cover 11.
[0012]
Therefore, it is difficult for foreign matter to stay in the labyrinth 6 or the slit 8, and there is no fear of the seal members 4, 5, 5 ′ being worn by the foreign matter, and an excellent sealing function can be exhibited for a long period of time. In addition, according to the configuration of this embodiment, as can be seen by comparing FIGS. 1 and 3, the existing main shaft end seal structure can be easily achieved by simply replacing the outer seal members 5, 5 ′ and the lid member 7. There is also an advantage that can be improved.
[0013]
When using a large volume of high-pressure cutting fluid, the plug 15 is removed, the air purge pipe 13 is connected to the connection port 14, and the labyrinth 6 is pressurized with high-pressure air. This makes it difficult for foreign matter to enter the labyrinth 6, and the foreign matter that has entered can be efficiently discharged to the outside through the second drain hole 10.
[0014]
The present invention is not limited to the above-described embodiment, and may be implemented by appropriately changing the shape and configuration of each part without departing from the spirit of the present invention, such as being applied to various machine tools other than a machining center. Is also possible.
[0015]
【The invention's effect】
As described above in detail, according to the onset bright, since the foreign object by utilizing the rotation of the main shaft is discharged to the outside from the drain hole, there is an effect capable of exhibiting long-term excellent sealing function.
Further, since the cover for preventing the backflow is provided on the lid member, there is an effect that the backflow of the foreign matter can be prevented.
[Brief description of the drawings]
FIG. 1 is a cross-sectional view of a main shaft end seal structure showing an embodiment of the present invention.
FIG. 2 is a front view of FIG. 1;
FIG. 3 is a cross-sectional view showing a conventional spindle end seal structure.
[Explanation of symbols]
1 ·· Main shaft 2 · · Main shaft head 3 · · Bearing 4 · · Inner seal member 5, 5 '· · Outer seal member 6 · · Labyrinth 7 · · Lid member 8 · · Slot 9 .. First drain hole, 10... Second drain hole, 11 .. Cover, 12 .. Small hole, 13 .. Air purge piping, 14.

Claims (1)

An inner seal member is fitted to the outer periphery of the tip of the spindle, an outer seal member is fitted to the inner periphery of the tip of the spindle head, a labyrinth is formed between the seal members, and the end surface of each seal member is narrowed by a lid member. Covering the gap, providing a first drain hole on the outer periphery of the lid member, and forming a second drain hole in the outer seal member, while preventing backflow from projecting outside the outlet of the second drain hole in the lid member The cover is provided with a large number of small holes for discharging foreign matter from the second drain hole, and the foreign matter that has entered the slit and labyrinth is rotated by the main shaft to form the first and second drains. A spindle end seal structure of a machine tool configured to be discharged to the outside through a hole.

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