JP5353158B2 - Spindle device for machine tools - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To provide a spindle unit for a machine tool capable of preventing a coolant liquid from entering the bearing of a spindle and also reducing an amount of supplied compressed air. <P>SOLUTION: The spindle unit for a machine tool includes: an annular spindle cap 8 fixed to the lower end of a spindle housing 2a; an annular nozzle forming member 12 fixed to the lower end of the spindle cap 8; an annular end surface cover 13 fixed to a circumference at the chip of the spindle 11; an inner peripheral annular wall 8a formed to protrude downward on an inner peripheral side of the spindle cap 8; an annular V-shaped groove 14 formed of the inner peripheral lower end of the nozzle forming member 12 and the outer peripheral lower end of the inner peripheral annular wall 8a; and an eave 13a formed at the outer peripheral lower end of the end surface cover 13 to cover an inner peripheral side of the V-shaped groove 14. <P>COPYRIGHT: (C)2010,JPO&amp;INPIT

Description

  The present invention relates to a spindle device for a machine tool, and more particularly to an apparatus that prevents coolant liquid from entering a bearing portion of a spindle through a gap between a spindle and a spindle housing of a spindle head when a workpiece is processed.

  Generally, when cutting with a machine tool, cutting is performed with a tool attached to the tip of the spindle while supplying a coolant liquid to a cutting portion of a metal workpiece, and the tool heated by frictional heat is cooled during cutting. This improves the machining accuracy and tool life of the workpiece.

  During machining of the workpiece, the splash of coolant supplied to the cutting site of the workpiece may enter the gap between the spindle and the spindle housing. When the coolant liquid enters the bearing portion of the main shaft, the grease filled in the sliding surface of the bearing portion flows out, and the bearing portion may be damaged by the rotation of the main shaft. For this reason, it is common to form a gap portion between the main shaft and the main shaft housing in a labyrinth shape, or to jet compressed air from the gap between the main shaft and the main shaft housing toward the tip side of the main shaft to enhance the sealing effect.

For example, in the sealing device in the spindle device for machine tools described in Patent Document 1, a shielding plate (end surface cover) that rotates integrally with the tip portion of the spindle is opposed to the tip surface of the spindle housing with a gap therebetween. It is arranged to do. In this shielding plate, a labyrinth portion comprising a plurality of annular protrusions protruding upward is provided between the front end surface of the spindle housing. Compressed air is supplied from a compressed air source to an air seal pocket portion of a lid (main shaft cap) fixed to the lower end of the main shaft housing, and is ejected to the outside from the opening end on the outer peripheral side of the labyrinth portion via the labyrinth portion.
JP 2002-263882 A

However, in the structure of the labyrinth portion described in Patent Document 1, the coolant is easily flown to the inner peripheral side of the labyrinth portion because the annular protrusion is simply provided and formed in a square wave shape in a longitudinal sectional view.
For this reason, it is necessary to supply a large amount of compressed air in order to prevent the coolant from entering the bearing portion of the main shaft, which increases the running cost.

  An object of the present invention is to provide a spindle device for a machine tool that can prevent the coolant liquid from entering the bearing portion of the spindle and reduce the amount of compressed air supplied.

The spindle device for a machine tool according to claim 1 includes a spindle in a vertical posture that is rotatably supported by a spindle housing of a spindle head, and a spindle device for a machine tool configured to mount a tool on a tip portion of the spindle. An annular main shaft cap fixed to the lower end of the main shaft housing, an annular nozzle forming member fixed to the lower end of the main shaft cap, and an annular end face cover fixed to the outer peripheral portion of the front end of the main shaft, and rotates together with the main shaft. An end face cover, an inner peripheral annular wall formed to protrude downward on an inner peripheral side portion of the spindle cap, an outer peripheral side lower end of the nozzle forming member, and an outer peripheral side of the inner peripheral annular wall An annular V-shaped groove formed by a lower end portion, and an annular communication portion formed for injecting compressed air to the outside between the annular vertical portion of the end face cover and the annular vertical portion of the inner peripheral annular wall portion And said A flange formed on the lower end of the outer peripheral side of the end surface cover so as to cover the inner peripheral side portion of the shaped groove and the opening portion of the annular communication portion from below, the V-shaped groove of the nozzle forming member A first annular inclined portion formed so as to move upward as it moves to the inner peripheral side at the inner peripheral lower end, and an outer peripheral side from the opening portion of the annular communication portion to the inner peripheral annular wall portion of the spindle cap And a second annular inclined portion formed so as to move upward as it shifts to.

  In the spindle device for machine tools, when the coolant liquid sprayed to the workpiece cutting site is scattered in the vicinity of the lower end of the spindle cap during machining of the workpiece, the flange portion is connected to the inner peripheral side portion of the V-shaped groove and the annular communication portion. Since the opening portion of the coolant is covered, it is difficult for the splash of coolant to adhere to the V-shaped groove. As a result, the coolant liquid is unlikely to enter the gap between the spindle cap and the end surface cover via the V-shaped groove.

  The spindle device for a machine tool according to claim 2 is the invention according to claim 1 or 2, wherein a third annular inclination that moves downward as the surface of the flange facing the V-shaped groove moves toward the outer peripheral side. It is characterized by being formed in the part.

  According to the first aspect of the present invention, the annular V-shaped groove formed of the inner peripheral lower end of the nozzle forming member and the outer peripheral lower end of the inner peripheral annular wall, and the inner peripheral portion of the V-shaped groove And a flange formed at the lower end of the outer peripheral side of the end surface cover that rotates together with the main shaft so as to cover, the flange that rotates together with the main shaft lowers the inner peripheral side portion of the V-shaped groove and the opening portion of the annular communication portion. By covering from the side, it is possible to suppress the splash of the coolant supplied to the cutting site of the workpiece from entering the gap between the spindle cap and the end surface cover via the V-shaped groove.

  Therefore, it is possible to prevent coolant liquid from entering the bearing portion of the spindle without supplying a large amount of compressed air from the gap between the spindle and the spindle housing of the spindle head toward the tip end side of the spindle. Cost can be reduced.

  Further, the V-shaped groove is formed in the first annular inclined portion formed so as to move upward as it moves to the inner peripheral side at the inner peripheral side lower end portion of the nozzle forming member, and the inner peripheral side annular wall portion of the spindle cap. And the second annular inclined portion formed so as to move upward as it moves from the opening portion of the annular communication portion to the outer peripheral side. , The fall of the coolant liquid adhering to the second annular inclined portion can be promoted. Thereby, it can suppress that coolant liquid penetrate | invades in the clearance gap between a spindle cap and an end surface cover.

  According to the second aspect of the present invention, since the surface of the flange portion facing the V-shaped groove is formed in the third annular inclined portion that moves downward as it moves toward the outer peripheral side, the spindle and the spindle housing of the spindle head The compressed air supplied from the gap to the front end side of the main shaft and the inclined surface of the third annular inclined portion cooperate to blow off the coolant liquid to the outer peripheral side of the V-shaped groove. Thereby, it can suppress that coolant liquid penetrate | invades in the clearance gap between a spindle cap and an end surface cover.

  Hereinafter, the best mode for carrying out the present invention will be described.

Embodiments of the present invention will be described below with reference to the drawings.
As shown in FIG. 1, a spindle head 1 of a machine tool includes a frame 2 and a spindle housing 2a that extend forward from a column (not shown), a support frame 2b that supports the spindle head 1, and a substantially L-shaped unclamp arm. 5 and a spindle device 10 for a machine tool. A nut 4 is fixed to the support frame 2b at an appropriate position, and the nut 4 is screwed and inserted into a rotatable ball screw (not shown) supported in parallel along a guide rail (not shown). The spindle head 1 is driven up and down in the Z-axis direction along the guide rail by the nut 4 and the ball screw by rotationally driving the ball screw in both forward and reverse directions by a Z-axis motor (not shown) arranged above the column. .

  Inside the spindle housing 2a, a spindle 11 is rotatably supported. The spindle 11 is configured such that a tool holder (not shown) with a tool (not shown) attached to the lower end (tip) thereof can be mounted. It is driven to rotate by a main shaft motor (not shown). Inside the frame 2, an unclamp arm 5 for releasing the clamp of the main shaft 11 with respect to the tool holder is pivotally supported by a support shaft 6.

Next, the spindle device 10 for machine tools will be described.
As shown in FIGS. 2 and 3, the machine tool spindle device 10 includes a spindle 11, an annular spindle cap 8, an annular nozzle forming member 12, an annular end surface cover 13, and an inner periphery of the spindle cap 8. It has a side annular wall portion 8 a, an annular V-shaped groove 14, a flange portion 13 a of the end surface cover 13, and a labyrinth seal 21 formed by the main shaft cap 8 and the end surface cover 13. A taper engagement hole 11a for taper engagement of the tool holder is formed in the lower end portion of the main shaft 11.

  A spindle cap 8 is fixed to the lower end of the spindle housing 2a with a plurality of bolts. An annular nozzle forming member 12 is fixed to the lower end of the main shaft cap 8 with a plurality of bolts. A coolant liquid or an air flow is directed toward the nozzle forming member 12 toward the axis of the main shaft 11. A nozzle 12b that injects in an inclined manner is formed. An inner peripheral side annular wall portion 8a is formed on the inner peripheral side portion of the main shaft cap 8 so as to protrude downward, and the outer peripheral side of the inner peripheral side lower end portion of the nozzle forming member 12 and the inner peripheral side annular wall portion 8a. An annular V-shaped groove 14 that opens downward is formed at the lower end.

  As shown in FIG. 3, the V-shaped groove 14 has an annular inclined portion 12 a (first annular inclined portion) formed so as to move upward as it moves to the inner peripheral side at the lower end on the inner peripheral side of the nozzle forming member 12. And an annular inclined portion 8b (corresponding to a second annular inclined portion) formed so as to move upward as it moves to the outer peripheral side at the outer peripheral side lower end portion of the inner peripheral annular wall portion 8a of the spindle cap 8. And have. An annular end surface cover 13 is fixed to the outer peripheral portion of the lower end (front end) of the main shaft 11 with a bolt, and the inner peripheral side portion of the V-shaped groove 14 is covered at the outer peripheral side lower end portion of the end surface cover 13. A collar portion 13a is formed. An annular inclined portion 13b (corresponding to a third annular inclined portion) that moves downward as it moves toward the outer peripheral side is formed on the upper surface of the flange portion 13a that faces the V-shaped groove 14.

  As shown in FIG. 3, a labyrinth chamber 15 communicating with the V-shaped groove 14 is formed between the inner peripheral side annular wall portion 8 a of the main shaft cap 8 and the outer peripheral side portion of the end surface cover 13. The labyrinth chamber 15 has an annular inclined portion 13d formed so as to move downward as it moves to the outer peripheral side at the outer peripheral side portion of the vertical middle portion of the end surface cover 13, and an inner peripheral annular ring facing the annular inclined portion 13d. An annular inclined portion 8c is formed at the lower end of the wall portion 8a so as to move upward as it moves to the outer peripheral side.

  An annular communication portion 16 is formed between the annular vertical portion 8 d connected to the annular inclined portion 8 c in the inner circumferential side annular wall portion 8 a and the annular vertical portion 13 c of the end surface cover 13. The V-shaped groove 14 and the labyrinth chamber 15 communicate with each other through the annular communication portion 16. The labyrinth chamber 15 communicates with a gap 17 between the inner peripheral side portion of the inner peripheral side annular wall portion 8 a and the outer peripheral side upper end portion of the end surface cover 13. The labyrinth chamber 15 is wider in the horizontal direction (perpendicular to the axis of the main shaft) than the horizontal width of the annular communication portion 16. The labyrinth chamber 15 is longer in the vertical direction than the vertical length of the annular communication portion 16. Therefore, the volume of the labyrinth chamber 15 is larger than the volume of the annular communication portion 16.

  A seal air pocket portion 19 is formed between the inner peripheral surface of the main shaft cap 8 and the outer peripheral surface of the main shaft 11. The seal air pocket portion 19 communicates with a gap 18 between the inner peripheral surface of the main shaft cap 8 and the outer peripheral surface of the main shaft 11. One end of a seal air pipe (not shown) connected to a compressed air supply source (not shown) is connected to the seal air pocket 19 via a compressed air supply passage 20 formed at the lower end of the spindle cap 8. Therefore, the compressed air supplied from the compressed air supply source to the seal air pocket portion 19 via the compressed air supply passage 20 is ejected from the annular communication portion 16 to the outside via the gaps 18 and 17 and the labyrinth chamber 15. It has become.

Next, operations and effects of the machine tool spindle device 10 described above will be described.
In the machine tool spindle device 10, compressed air is supplied from the compressed air supply source to the seal air pocket portion 19 through the compressed air supply passage 20 when a workpiece is processed. The compressed air ejected from the annular communication portion 16 via the gaps 18 and 17 and the labyrinth chamber 15 flows along the annular vertical portion 13 c and the annular inclined portion 13 b of the end surface cover 13.

  When the splash of the coolant supplied to the cutting part of the workpiece is scattered near the lower end of the spindle cap 8, the flange portion 13 a covers the annular communication portion 16, and the coolant liquid does not splash directly on the annular communication portion 16. . Therefore, the pressure of the coolant liquid that enters the annular communication portion 16 is lower than that when the coolant liquid directly enters. Further, when the coolant liquid scatters in the V-shaped groove 14, the coolant liquid falls due to the inclination of the annular inclined portion 8 b, and the pressure of the coolant liquid that enters the annular communication portion 16 is attenuated.

  Further, since the coolant fluid is blown off to the outer peripheral side of the V-shaped groove 14 by the pressurized air supplied from the compressed air supply passage 20, the coolant pressure entering the annular communication portion 16 is attenuated. As a result, the coolant liquid is less likely to enter the labyrinth chamber 15 via the V-shaped groove 14 when the spray of the coolant splashes near the lower end of the spindle cap 8. The coolant liquid that has entered through the annular communication portion 16 is guided to the annular communication portion 16 by the inclination of the annular inclined portion 8c and the annular inclined portion 13d.

  The volume of the labyrinth chamber 15 is larger than the volume of the annular communication portion 16. Therefore, the coolant liquid that has entered the labyrinth chamber 15 spreads in the horizontal direction, and the pressure of the coolant liquid that has entered from the annular communication portion 16 is reduced. The coolant liquid whose pressure has been reduced is guided to the annular communication part 16 by the inclination of the annular inclined part 13d. As a result, the coolant liquid that has entered from the annular communication portion 16 is reduced in pressure through the labyrinth chamber 15, and is difficult to enter the gaps 17 and 18.

  In this way, the flange portion 13a covers the inner peripheral side portion of the V-shaped groove 14 so that the splash of coolant liquid supplied to the cutting portion of the workpiece enters the labyrinth chamber 15 via the V-shaped groove 14. Can be suppressed. Since the volume of the labyrinth chamber 15 is larger than the volume of the annular communication portion 16, even when the coolant liquid enters the labyrinth chamber 15 through the V-shaped groove 14, the pressure of the coolant liquid in the labyrinth chamber 15 is reduced. The flow of the coolant liquid can be attenuated. Therefore, it is possible to prevent the coolant liquid from entering the bearing portion of the main shaft 11 without supplying a large amount of compressed air from the seal air pocket portion 19 toward the front end side of the main shaft 11, thereby reducing the running cost. Can be achieved.

  Since the annular V-shaped groove 14 constituted by the lower end on the inner peripheral side of the nozzle forming member 12 and the lower end on the outer peripheral side of the inner peripheral side annular wall 8a and communicating with the labyrinth chamber 15 is formed. The supplied coolant liquid can collide with the V-shaped groove 14 to drop the coolant liquid. Since the V-shaped groove 14 has the annular inclined portion 12a and the annular inclined portion 8b, the fall of the coolant adhering to the annular inclined portions 12a and 8b is promoted using the inclined surfaces of the annular inclined portions 12a and 7b. Can do. Thereby, it is possible to suppress the coolant liquid from entering the labyrinth chamber 15.

  Since the labyrinth chamber 15 has the annular inclined portion 13d and the annular inclined portion 8c, when the coolant liquid enters the labyrinth chamber 15 and adheres to the annular inclined portion 8c, the coolant liquid is utilized using the inclined surface of the annular inclined portion 8c. The fall to the annular inclined portion 13d can be promoted. Furthermore, the dropped coolant liquid can be effectively discharged from the annular communication portion 16 to the outside using the inclined surface of the annular inclined portion 13d.

  Since the upper surface of the flange portion 13a that faces the V-shaped groove 14 is formed in the annular inclined portion 13b, the compressed air ejected from the annular communicating portion 16 and the inclined surface of the annular inclined portion 13b cooperate to generate a coolant liquid. Can be blown off to the outer peripheral side of the V-shaped groove. Thereby, it is possible to suppress the coolant liquid from entering the labyrinth chamber 15.

Next, a modified example in which the above embodiment is partially modified will be described.
1] An outside air introduction passage 31 for introducing outside air into the labyrinth chamber 15 may be provided in the nozzle forming member 12. As shown in FIG. 4, a cover member 30 is fixed to the lower end of the outer periphery of the nozzle forming member 12, and an outside air introduction passage 31 that communicates with the labyrinth chamber 15 is provided in the nozzle forming member 12 and the cover member 30. An outside air introduction port 31 a is provided at the lower end of the cover member 30, and outside air can be introduced from the outside air introduction port 31 a into the labyrinth chamber 15 through the outside air introduction passage 31.

Since the outside air introduction passage 31 for introducing outside air into the labyrinth chamber 15 is provided in the nozzle forming member 12 and the cover member 30, the pressure in the labyrinth chamber 15 becomes almost atmospheric pressure, and the coolant liquid that has entered the labyrinth chamber 15 The pressure can be reduced sufficiently. Thereby, since it is possible to prevent the coolant liquid from entering the bearing portion of the main shaft 11 without supplying compressed air, the running cost can be significantly reduced.
2] A two-stage configuration in which another labyrinth chamber communicating with the labyrinth chamber 15 is provided on the upper side of the labyrinth chamber 15 may be adopted. In this case, the effect of preventing the coolant liquid from entering the bearing portion of the main shaft 11 is further enhanced.

It is a side view of the spindle head concerning the example of the present invention. It is a longitudinal cross-sectional view of the spindle device for machine tools. It is an expanded sectional view of the tip part of the spindle device for machine tools. It is an expanded sectional view of the tip part of the spindle device for machine tools in the example of change.

DESCRIPTION OF SYMBOLS 1 Main shaft head 2a Main shaft housing 8 Main shaft cap 8a Inner peripheral side annular wall part 8b, 12a, 13b Annular inclined part 10 Machine tool main shaft apparatus 11 Main shaft 12 Nozzle formation member 13 End surface cover 13a Gutter part 14 V-shaped groove 31 Outside air introduction passage

Claims (2)

In a spindle device for a machine tool comprising a spindle in a vertical posture rotatably supported on a spindle housing of a spindle head, and configured to mount a tool on the tip of the spindle,
An annular main shaft cap fixed to the lower end of the main shaft housing;
An annular nozzle forming member fixed to the lower end of the spindle cap;
An end face cover that is an annular end face cover that is fixed to the outer peripheral portion of the front end of the main shaft and rotates together with the main shaft;
An inner circumferential annular wall formed to project downward on the inner circumferential side portion of the spindle cap;
An annular V-shaped groove constituted by an inner peripheral lower end of the nozzle forming member and an outer peripheral lower end of the inner peripheral annular wall;
An annular communication portion formed to eject compressed air to the outside between the annular vertical portion of the end surface cover and the annular vertical portion of the inner peripheral annular wall portion;
A flange formed on the outer peripheral side lower end portion of the end surface cover so as to cover the inner peripheral side portion of the V-shaped groove and the opening portion of the annular communication portion from below;
The V-shaped groove has a first annular inclined portion formed so as to move upward at the inner peripheral side lower end portion of the nozzle forming member, and an inner peripheral annular wall portion of the spindle cap. And a second annular inclined portion formed so as to move upward as it moves from the opening portion of the annular communication portion to the outer peripheral side.   2. The spindle device for a machine tool according to claim 1, wherein a surface of the flange portion facing the V-shaped groove is formed in a third annular inclined portion that moves downward as it moves toward the outer peripheral side. .