JP2521566B2 - High speed spindle head with fan for spindle cooling - Google Patents

Description

TECHNICAL FIELD The present invention relates to a high-speed spindle head with a spindle cooling mechanism for machine tools.

Conventional technology Conventionally, a high-speed spindle head of a machine tool is usually provided with a cooling mechanism that suppresses heat generation from the main bearing section due to high-speed rotation to prevent seizure accidents. Is often performed by oil air, oil jet, etc. that can perform lubrication and cooling at the same time. In addition to this, the bearing housings 101, 10 as shown in FIG.
2, jackets 101a and 102a for cooling liquid are provided,
A method of sending a cooling liquid from the outside to cool the bearing from the outer peripheral side is also used.

DISCLOSURE OF THE INVENTION Problems to be Solved by the Invention The cooling method described in the prior art is to cool the bearing and the bearing housing side, and since the cooling effect on the spindle is small, the rise in temperature of the spindle hinders high-speed rotation. There is a problem that

The present invention has been made in view of the above problems of the prior art, and an object of the present invention is to provide a cooling air passage and a fan inside the main shaft and directly cool with cooling air. The present invention aims to provide a high-speed spindle head capable of achieving higher speed by reducing thermal displacement of the spindle.

Means for Solving the Problems In order to achieve the above object, the high-speed spindle head with a fan for cooling the spindle of the present invention is a screw having a twist angle in the direction of sending air to the spindle rear side by the rotation of the spindle. An air passage is formed at the center of the tool pull rod inserted into the bearing center hole and inserted into the spindle center hole, and an axial flow fan is attached to the air passage inlet of the tool pull rod and at the outer end of the tool pull rod. An air feeding fan is attached, and a member for ejecting air toward the air passage of the tool pull rod is provided, and the air blown by the axial flow fan and the air feeding fan that rotates with the rotation of the main shaft is the air. The passages and screws are configured to flow efficiently.

The axial air fan provided at the inlet of the cooling air passage at the rear end of the center hole of the tool pulling rod that rotates with the main shaft allows the cooling air to flow into the passage without leaking from the labyrinth seal surface and to the main shaft center hole. The main shaft is cooled by the cooling air flowing through the air passage between the tube and the tube. The air which has served as a cooling and has reached the outlet at the rear end of the spindle center hole is sucked out by the sirocco fan provided at the rear end of the outer periphery of the tool pulling rod and discharged to the outside.

Example An example will be described with reference to FIGS. 1 to 3.

In a spindle head of a known machining center, a sleeve 2 is fitted into a hole 1a formed in a spindle unit main body 1 fixed to the spindle head, and a sleeve 2 is fitted in a central portion of the sleeve 2 via a cylindrical outer frame 3 The stator 4A of the motor 4 is fitted, the front bearing housing 5 is fitted on the right side of the hole 1a, and the rear bearing housing 6 is fitted on the left side of the hole 1a. The main shaft 7 is rotatably supported by a plurality of front bearings 8 and rear bearings 9 which are fitted into the bearing housings 5 and 6, and a rotor 4B of the main motor 4 is fitted to the outer periphery of the central portion. The central hole 7a of the spindle 7 is
The tip part is formed in the tool mounting taper hole 7d, and the contact area with air is increased at the positions corresponding to the front bearing 8 and the rear bearing position 9 of the center hole 7a. Screws 7b and 7c with a left twist angle for sending to the left
Is engraved. The tube 11 is press-fitted into the inner periphery of the screws 7b and 7c, and the gap between the tube 11 and the main shaft serves as an air passage. Further, a tool pulling rod 12 is fitted in the tube 11 so as to be movable in the axial direction. The tool pulling rod 12 has a through center hole 12a which serves as an air passage, and the pull stud of the tool T is provided at the tip of the center hole 12a. A well-known collet 14 that holds the Ta head so that it can be opened and closed is screwed through a piece 13. This piece 13 has a central hole that serves as an air passage, and the collet 14 has a vertical split groove that serves as an air passage.

The right side portion of the left large-diameter portion of the tool pulling rod 12 projecting from the tube 11 is fitted into the left end portion of the shaft center hole 12a with a gap, and this gap serves as an air passage.

On the other hand, on the left end face of the spindle unit body 1, the bracket 16
Are fixed concentrically, and a hydraulic cylinder 17 is fitted in a central hole of the bracket 16 so as to be movable in the axial direction. The piston 18 fitted into the hydraulic cylinder 17 is formed integrally with the cylinder 22. The cylinder 22 is axially movably fitted to the outer periphery of the right side collar 21 of the disc spring 19 fitted to the rear end of the main shaft, and the left side collar 24 of the disc spring 19 is axially movably inserted. The disc spring pressing ring 23 is screwed to the left end of the hydraulic cylinder 17. The color 24 on the left is
Nut 25 whose left end face is screwed to the large diameter part of the tool pull rod 12
The right end face of the is pressed by the force of the disc spring 19 and always urges the tool pulling rod 12 to pull it up freely. And hydraulic cylinder
Pressure oil is sent to the right chamber of 17 and the hydraulic cylinder moves to the right.
Goes left and contacts the end of the collar 21a of the right collar 21, the ring 23 screwed to the hydraulic cylinder 17 goes right and the collar on the left
The disk spring 19 is compressed by abutting on the end surface of the collar portion 24a of 24 (Fig. 1 lower half). As a result, the left collar 24 is separated from the right end surface of the nut 25, and the tool T is released from the clamp.

A sirocco fan 25a as shown in the cross-sectional view of FIG. 3 is engraved at the contact portion of the right end of the nut 25 with the right collar 21, and when the main shaft 7 rotates right, the main shaft center hole 7a from the left end The cooling air that is sent out is sucked out and released into the atmosphere.

The center hole 12a of the tool pull rod has a large diameter hole 12b formed at the left end thereof, and a fan ring 26 is press-fitted into the large diameter hole 12b. Further, a tip end of an air guide rod 27 fixed to a spindle head (not shown) is fitted into the large diameter hole 12b via a labyrinth seal.

 Next, the operation of this embodiment will be described.

Now, the spindle 7 is rotated at high speed with the tool T attached.

Cooling air is ejected from the tip nozzle portion of the air guide rod 27 toward the center hole of the fan ring 26, and the ejected air rides on the air flow of the axial fan 26a of the fan ring 26 and is outside the labyrinth seal surface. Flows into the center hole 12a of the tool pull rod without leaking into the hole. Then, it passes through the vertical split groove of the collet 14 and reaches the tip of the tube 11, where the direction is changed to 18
After turning 0 °, it flows into the gap between the central hole 7a of the main shaft 7 and the tube 11. Then, first, when passing through the groove of the screw 7b formed in the right end portion of the center hole 7a, the portion corresponding to the front bearing 8 having a large heat generation amount of the main shaft is cooled. Next, it reaches the screw 7c through a gap in the center of the center hole 7a, and cools the portion corresponding to the rear bearing 9 when passing through the groove of the screw 7c. When the air that has achieved the purpose reaches the rear end of the center hole 7a, it is sucked by the sirocco fan 25a and discharged to the outside.

EFFECTS OF THE INVENTION Since the present invention is configured as described above, it has the following effects.

The fan that rotates with the main shaft facilitates the inflow and outflow of the air for cooling the main shaft, and directly cools the main shaft by air, so the temperature rise of the main shaft due to the heat transferred from the bearing is suppressed and thermal displacement is prevented. It is possible to prevent this, and it is expected that the spindle will rotate at a higher speed.

[Brief description of drawings]

FIG. 1 is a sectional view of a high speed spindle head with a fan according to the present invention, FIG.
The figure is a sectional view taken along the line AA of FIG. 1, and FIG. 3 is the line B- of FIG.
FIG. 4 is a sectional view taken along line B, and FIG. 4 is a sectional view of a spindle head having a conventional main bearing housing side cooling mechanism. 7 ... Main shaft, 25a ... Sirocco fan, 26a ... Axial fan

Claims (1)

(57) [Claims] 1. A screw having a twist angle in the direction of sending air to the rear side of the main shaft by rotating the main shaft is engraved at a bearing corresponding position of the main shaft center hole, and an air passage is formed in the center of a tool pull rod inserted through the main shaft center hole. A fan for air flow is attached to the air passage inlet of the tool pull rod, and an air feed fan is attached to the outer end of the tool pull rod, and a member for ejecting air toward the air passage of the tool pull rod is attached. The air blown by the axial flow fan and the air feeding fan that rotate with the rotation of the main shaft
A high-speed spindle head with a fan for cooling the spindle that is configured to allow the screw to flow efficiently.