JPH11235641A - Main spindle device for machine tool - Google Patents

Abstract

PROBLEM TO BE SOLVED: To lubricate uniformly, exactly, and stably a tip part of a cutting tool wherein a relatively deep place of a work is worked with a misty cutting fluid generated in a main spindle by supplying compressed air and cutting fluid in the main spindle without using a rotary joint. SOLUTION: A main spindle 3 is provided at its tip end with a tool holder 8 and a cutting tool 30, and formed at its central part with a bore 3b in an axis direction from an outer end of the main spindle 3 to a tip part. A cutting fluid supplying pipe 25 is installed in an inserted manner in the bore 3b, and held in a non-rotating state even if the main spindle 3 is rotated. The cutting fluid supplying pipe 25 is formed with a liquid passage and a gas passage in the internal longitudinal direction, and formed at its tip near a tool holder 8 with an atomizing means 27. The atomizing means 27 causes a cutting fluid supplied from the liquid passage to atomize by gas supplied from the gas passage. A misty cutting fluid generated by the atomizing means is ejected from the tip of a cutter 30 via passages 32, 30a in the tool holder 8 and the cutter 30.

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a spindle device of a machine tool which is particularly suitable for lubricating a tip portion of a cutting tool for machining a deep part.

[0002]

2. Description of the Related Art In machining with a machine tool, a large amount of cutting oil is supplied to a machining portion for cooling and lubricating a workpiece and a cutting tool, or removing chips, but this causes environmental pollution caused by the cutting oil. Other problems, such as adverse effects on human health and human health, large costs associated with waste oil treatment of cutting oil, reduced tool life due to excessive cooling of the workpiece, and sliding wear during fine cutting of the cutting tool due to excessive cutting oil. Since a large amount of cutting oil adheres to the chips during processing, it is necessary to separate the cutting oil adhering to the chips when processing and reusing the chips.

In order to solve these problems, in recent years, a very small amount of cutting oil has been supplied in the form of mist to a cutting portion. Such a process is called dry cutting or the like. I have.

[0004] In performing dry cutting, it is possible to supply mist-like cutting oil to the tip of a cutting tool which is processing a relatively shallow portion of the work by simple means. It is practically difficult to feed it to the tool tip which is machining a relatively deep part. The present applicant has disclosed Patent No. 268711 as a means for solving this.
No. 0 is proposed.

[0005]

The above-mentioned Patent No. 26871
According to the spindle device of No. 10, mist-like cutting oil can be supplied very effectively to the tip of the cutting tool for machining a relatively deep portion of the workpiece. When a cutting fluid is supplied from the outside in a stationary state, a rotary joint is required, and the structure is complicated. An object of the present invention is to provide a spindle device of a machine tool capable of coping with the above-mentioned situation without requiring a rotary joint.

[0006]

In order to achieve the above object, according to the present invention, an axial hole extending from the outer end of the spindle to the tip is formed in the center of the spindle having a tool holder and a cutting tool at the tip. A cutting agent supply pipe which is kept in a non-rotating state even when the main shaft is rotated is inserted into the hole, and the supply pipe has a liquid passage and a gas passage formed at an internal longitudinal direction thereof and a tool. Atomization means for atomizing the cutting fluid supplied from the liquid passage by the gas supplied from the gas passage is formed at the tip located near the holder, and the mist generated by the atomization means is formed. The cutting fluid is ejected from the tip of the cutting tool through a tool holder and a passage in the cutting tool.

During the processing of the workpiece, the main shaft is rotated. During this rotation, the cutting agent supply pipe is kept in a non-rotating state, and the cutting liquid and the gas are supplied to the atomizing means in the main shaft through the liquid passage and the gas passage. At this time, the cutting fluid flowing in the fluid passage is not affected by the rotation of the main shaft at all and flows smoothly. The atomized cutting fluid generated by the atomizing means is jetted from the tip of the cutting tool in a stable and relatively uniform distribution state, and effectively lubricates the tip of the cutting tool that has reached a deep part of the non-workpiece.

[0008]

DESCRIPTION OF THE PREFERRED EMBODIMENTS First, a first embodiment of the present invention will be described. FIG. 1 is a sectional view showing a spindle device according to the present embodiment, FIG. 2 is a partially enlarged sectional view of the spindle device, and FIG. X1 in FIG.
It is the elements on larger scale which show -x1 part.

In these figures, reference numeral 1 denotes a main body frame of the spindle device, and 2 denotes a cylindrical support frame fixed to the main body frame 1 by bolts. The spindle 3 is attached to the cylindrical support frame 2
Are rotatably inserted at fixed positions via bearings 4a and 4b.

At this time, 5a and 5b are ring members fixed to the front end face and the rear end face of the cylindrical support frame 2, 6a and 6b are cylindrical spacers for regulating the positions of the bearings 4a and 4b, and 7 is a bearing. 4b is a threaded ring body for pressing the rear surface of the inner ring of 4b.

The main shaft 3 has a tapered hole 3a at the center of the distal end in which the tapered shank portion 8a of the tool holder 8 is fitted, and a straight central hole 3b is formed continuously with the tapered hole 3a.

Reference numeral 9 denotes a guide cylinder member inserted into the center hole 3b in a state in which the forward movement is locked at the front portion thereof, and an inner peripheral surface 9a of the guide cylinder member is formed with a step portion of an appropriate shape. It has been done. Reference numeral 10 denotes a drawbar, and a guide tube member 9
And a flange 10b guided at the inner peripheral surface of the center hole 3b at a position near the rear end, and a straight hole 10c formed at the center. is there.

Reference numeral 11 denotes a coned disc spring, which is provided in a stepped and compressed state in a center hole 3b which is located in the middle of the length of the draw bar 10 and between the rear end of the guide cylinder member 9 and the flange 10b. ing.

Reference numeral 12 denotes a holding cylinder member for holding the clamp member 13 so as to be openable and closable, and is screwed to the tip of the draw bar 10. A concave 12a with which the clamp member 13 engages is formed on the peripheral surface of the holding cylinder member 12, and the clamp member 13 is composed of a plurality of locking pieces, which are arranged in the circumferential direction of the concave 12a. It is made cylindrical.

Reference numeral 14 denotes a pulley fixed to the outer periphery of the rear end of the main shaft 3, to which rotation is input from a motor (not shown) via a belt.

Reference numeral 15 denotes an end face cover member fixed to the rear end face of the main shaft 3 by bolts. A rear end portion 10c of the draw bar 10 is inserted into a center hole of the end cover member so as to be displaceable in the front and rear directions f1 and f2.

Reference numeral 16 denotes a locking ring plate which is fitted to the rear end of the main shaft 3 and locked by the end face cover member 15 so as to prevent the rearward escape. This locking ring plate 16
On the rear surface, a cylinder member 17 and a cylinder cover 18 are arranged in this order and fixed by bolts, and a stepped piston 19 is inserted inside the cylinder member 18.

This piston 19 has a center hole and a rear projection 1.
9a, and the rear projection 19a is
8 is inserted into the center hole 8 so as to be slidable in the front and rear directions f1 and f2. At this time, reference numeral 20 denotes a screw pipe member screwed into the center hole of the piston 19, which is displaced by its rotation operation and fastened to its position by the lock nut 21. A passage p1 provided in the cylinder member 18 leads into the cylinder chamber 22 behind the piston 19, and the other passage p2
9 communicates with the cylinder chamber 23 on the front side.

Reference numerals 24a and 24b denote support frames fixed to the main frame 1, and 25 denotes a support frame.
Is a straight lubricant supply pipe fixed through a coupling member 26 to the lubricant supply pipe. The support frame 24b supports the cylinder member 17 so as to be able to move slightly back and forth.
8 and the support frame 24b, the cylinder cover 1
A spring s is provided for pressing the front end 8 forward f1.

The lubricant supply pipe 25 has an outer pipe 25a and an inner pipe 25.
The inner tube 25b has a liquid passage a and the gas passage b between the inner tube 25b and the outer tube 25a.

At the end of the lubricant supply pipe 25, atomizing means 27 is formed for atomizing the cutting fluid supplied through the liquid passage a with the air supplied through the gas passage b. The atomizing means 27 has a liquid injection port c formed by squeezing the tip of the inner tube 25b and a gas injection port d surrounding the liquid injection port c, but is not limited to this.

At this time, the cutting fluid is supplied to the fluid passage a from a fluid supply device (not shown) provided on the stationary side, and the gas passage is supplied with air of an appropriate pressure from a gas supply device (not shown) provided on the stationary side. To be done.

A lubricant supply pipe 25 is rotatable at a fixed position of the main shaft 3 at the rear end of the draw bar 10 and inside the center hole of the holding cylinder member 12, so that a bearing 2 is provided between the two.
8a and 28b are mounted. These bearings 28a, 28
Although b is a ball bearing in the illustrated example, it may be a needle bearing. If the needle bearing is formed, the lubricant supply pipe 2 of the draw bar 10 may be used.
This contributes to enabling a slight displacement in the front-back directions f1 and f2 with respect to the fifth direction. A seal ring SR1 is provided between the holding cylinder member 12 and the bearing 28a, and the cutting agent supply pipe 25 is connected to the hole 1 of the draw bar 10 through the seal ring SR1.
0c and penetrates rotatably and gas-tightly.

The tool holder 8 includes a tapered shank 8a, a flange 8b, and a chuck 8c.
a is fitted into the tapered hole 3 a of the main shaft 3.

The tapered shank portion 8a has a pull stud 29 at the rear end thereof which is locked by the clamp member 13, and the flange portion 8b has a recess m which is to be gripped by the automatic tool changer when the tool is changed. It is formed, and the chuck portion 8c is for fixing the cutting tool 30.

The tool holder 8 has a center hole 8d formed therein. An inner fitting member 31 is provided in the middle of the length of the center hole 8d, and the center hole of the inner fitting member 31 and the center hole of the pull stud 29 are connected to the connecting pipe 32. Are combined.

The type of the cutting tool 30 is not limited, such as a drill, a reamer, a tap or a milling, but it is necessary that the cutting tool 30 has a passage 30a extending from the rear end to the front end.

The use example and operation of the spindle device configured as described above will be described below. That is, the tool holder 8 mounted as shown in FIGS.
At the time of extraction from the cylinder, a pressurized fluid is supplied into the cylinder chamber 22 after an automatic tool changer (not shown) grasps the flange 8b of the tool holder 8. As a result, the piston 19 is displaced forward f1 against the elasticity of a spring (not shown). When the displacement exceeds a predetermined value, the locking ring plate 16 and the end face cover member 15 are pressed against each other and the screw pipe is pressed. The front end of the member 19 presses the rear end of the draw bar 10, displacing the draw bar 10 forward f 1 against the elasticity of the disc spring 11.

The forward displacement of the draw bar 10 is determined by the holding cylinder member 1.
2 and the clamp member 13 are displaced forward f1. When the displacement becomes equal to or larger than a predetermined value, the distal end of the clamp member 13 is disengaged from the projection on the inner peripheral surface of the holding cylinder member 12 and moves outward in the radial direction of the holding cylinder member 12. Can be displaced.

In this state, the automatic tool changer applies a pulling force to the tool holder 8 to the front f1. At this time, the pull stud 29 is hooked on the clamp member 13 in a state where the clamp member 13 can be released. Therefore, the tool holder 8 is pulled out from the main shaft 3 because the tool holder 8 comes out from the inside of the clamp member 13.

On the other hand, when the tool holder 8 is mounted on the main spindle 3, the draw bar 10 is held in the same state as when the tool holder 8 is removed from the main spindle 3, and in this state, the automatic tool changer operates the tool holder 8 The tapered shank 8a is inserted into the tapered hole 3a of the main shaft 3. At this time, the pull stud 29 is inserted into the clamp member 13 without being hooked because the clamp member 13 is in the release operable state.

In connection with the end of this insertion, the cylinder chamber 22
The pressure fluid inside is discharged, and the pressure fluid is supplied into the other cylinder chamber 23. As a result, the piston 19 is displaced rearward, the screw tube member 21 is separated from the draw bar 10, and the draw bar 10 retreats to the original position shown in FIG.

Due to the retreat, the clamp member 13 is pressed by the projection on the inner peripheral surface of the guide cylinder member 9 at the outer periphery of the leading end, and the diameter thereof is reduced.
The projection at the tip of the inner peripheral surface is locked by the narrow portion of the pull stud 29, and the pull stud 29 is further pulled by the elasticity of the disc spring 11. As a result, the tool holder 8 is tightly fitted on the main shaft 3. In this fitted state, the gap between the rear end of the pull stud 29 and the front end of the cutting agent supply pipe 25 is generally about 0.5 to 1 mm. After this,
The automatic tool changer separates the tool holder 8 and retracts.

When processing the work w, rotation is input to the pulley 14 from a motor (not shown). Thus, the main shaft 3 rotates while being guided by the bearings 4a and 4b. At this time,
Cylinder member 17 and piston 19 are supported frame 2
4b, it does not rotate, and when the pressurized fluid is supplied into the cylinder chamber 23, the locking plate member 16 is displaced forward f1 by the elastic force of the spring s and separates from the end face cover member 15. In this state, no rotational resistance is applied to the main shaft 3. Further, the piston 19 is also separated from the end face cover member 15 and does not hinder the rotation of the main shaft 3.

On the other hand, the cutting agent supply pipe 25 is
Since it is fixed to the same body as 4a, it is kept in a non-rotation state irrespective of the rotation of the main shaft 3.

Under this condition, compressed air is supplied to the gas passage b from the stationary gas supply device through the coupling member 26, and during this supply, the compressed liquid is supplied from the stationary liquid supply device to the coupling member 26.
The cutting fluid is supplied to the fluid passage a through the passage. Thus, the air supplied to the gas passage b is jetted from the gas jet port d of the atomizing means 27, and the cutting fluid supplied to the liquid passage a is jetted from the liquid jet port c of the atomizing means 27.

The atomizing means 27 forms the liquid jetted from the liquid jet port a into a uniformly distributed mist by the compressed air jetted from the gas jet port d, and jets the liquid toward the tool holder 8 side. The atomized cutting fluid thus jetted reaches the rear end of the cutting tool 30 through the communication pipe 32 at the center of the tool holder 8, and is jetted from the front end through the passage 30a of the cutting tool 30.

At this time, the mist cutting fluid flowing in the fluid passage a to the front f1 is not affected by the centrifugal force due to the rotation of the main shaft 3, and the cutting fluid is stably jetted from the fluid injection port c. This contributes to the generation of the mist cutting fluid having a uniform distribution. Also, from the atomizing means 27 to the blade 3
0 The small distance to the tip does not reduce the effect of centrifugal force due to the rotation of the main shaft 3 on the atomized cutting fluid moving from the atomizing means 27 to the tip of the cutting tool 30, and therefore the atomized cutting fluid has a specific gravity of the cutting fluid component It is guided to the vicinity of the tool holder 8 without causing component separation or liquefaction due to the difference, and is ejected from the tip of the blade 30 in a relatively uniform distribution state.

Further, the atomized cutting fluid ejected from the tip of the cutting agent supply pipe 25 tends to flow back along the outer peripheral surface of the cutting agent supply pipe 25, but is restricted by the sealing action of the seal ring SR1. What is going to flow backward along the outer peripheral surface of the draw bar 10 is regulated by the sealing action at the enlarged end portion 10a of the draw bar 10.

In this state, the spindle device is displaced with respect to the work w to perform required machining. At this time, even if the tip of the cutting tool 30 is in a state of processing a relatively deep position of the work w, the cutting tool 30 is evenly and effectively lubricated and performs accurate processing.

Next, a second embodiment of the present invention will be described. FIG. 4 is a sectional view showing a spindle device according to the present embodiment, and FIG.
3 is a partially enlarged view showing an x2-x2 portion of FIG. In the drawing, substantially the same parts as those in the previous embodiment are denoted by the same reference numerals.

The tool holder 8 is fixed to the tip of the main shaft 3 by bolts, and a cutting tool 30 is fixed to the tip by screwing.

There is no fundamental difference between the cutting agent supply pipe 25 and the atomizing means 27. Since the automatic attachment and detachment of the tool holder 8 by the automatic tool changer is not considered, the cylinder member 17 and the piston 19 in the previous embodiment are not provided.

The front end of the cutting agent supply pipe 25 is desirably located in the center hole 8d of the tool holder 8 and the center hole 3b of the main shaft 3 is provided.
A cover member 33 for closing the space between the cutting agent supply pipe 25 and the cutting agent supply pipe 25 is fixed by bolts. At this time, SR2 is a seal ring, and the cutting agent supply pipe 27 is rotatably and gas-tightly penetrated through the center of the cover member 33 via the seal ring SR2.

In the spindle device of this embodiment, the tools are changed manually. When processing the workpiece w, rotation is input via the pulley 14, whereby the main shaft 3, the tool holder 8, the cutting tool 30, the cover member 33, and the like are rotated.

Thereafter, compressed air and a cutting fluid are supplied to the atomizing means 27 to generate a mist-like cutting fluid, which is jetted from the tip of the cutting tool 30 to process the work w.

Also in this embodiment, since the cutting agent supply pipe 25 does not rotate, the cutting liquid supplied through the pipe is stably formed into a mist-like cutting liquid having a uniform distribution. Without being affected by the centrifugal force of the workpiece w, the tip of the blade 30 is machined at a relatively deep position of the work w, and is effectively lubricated in the same manner as in the previous example. Will do.

[0048]

According to the present invention constructed as described above, compressed air and cutting fluid are supplied into the main shaft without the need of a rotary joint, and mist-like cutting fluid is generated in the main shaft. With this mist-like cutting fluid, it is possible to uniformly, reliably and stably lubricate the edge of a cutting tool which is processing a relatively deep portion.

[Brief description of the drawings]

FIG. 1 is a sectional view showing a spindle device according to a first embodiment of the present invention.

FIG. 2 is a partially enlarged sectional view of the spindle device.

FIG. 3 is an enlarged view showing an x1-x1 portion of FIG.

FIG. 4 is a sectional view showing a spindle device according to a second embodiment of the present invention.

FIG. 5 is an enlarged view showing a portion x2-x2 of FIG.

[Explanation of symbols]

 Reference Signs List 3 main shaft 3b hole 8 tool holder 25 cutting agent supply pipe 27 atomizing means 30 cutting tool 30a passage 32 passage a liquid passage b gas passage

Claims (1)

[Claims] An axial hole extending from the outer end of the main shaft to the front end portion is formed in a central portion of the main shaft having a tool holder and a cutting tool at a front end thereof. A cutting agent supply pipe held in is inserted, and this supply pipe is formed with a liquid passage and a gas passage at an internal longitudinal position, and is supplied from the liquid passage to a tip located near the tool holder. Atomizing means for atomizing the cutting fluid by a gas supplied from a gas passage is formed, and the mist-like cutting fluid generated by the atomizing means passes through a tool holder or a passage in the cutting tool to form a cutting tool tip. A spindle device for a machine tool, which is ejected from a machine.