WO2002064310A1

WO2002064310A1 - Main shaft device for machine tools

Info

Publication number: WO2002064310A1
Application number: PCT/JP2002/001157
Authority: WO
Inventors: Shinsuke Sugata; Tadashi Makiyama
Original assignee: Horkos Corp
Priority date: 2001-02-16
Filing date: 2002-02-12
Publication date: 2002-08-22
Also published as: JP3671392B2; TW553792B; JP2002239869A

Abstract

Cutting liquid mists are prevented from becoming liquid as they are subjected to centrifugal force due to rotation of a main shaft (2) in a region extending from a mist outlet member (23) to an area in the vicinity of the rear end of a cutting implement (25). Further, it is made possible to easily form a construction in which the sectional area of a passageway for mist outlet extending from the mist outlet member (23) to an area in the vicinity of the rear end of the cutting implement (25) will not sharply change with respect to a change in the lengthwise position thereof. In a main shaft device for machine tools wherein the center hole of the main shaft (2) is internally provided with a mist generating section (16) that is nonrotatable and the cutting liquid mists spouted from the mist outlet member (23) of the mist generating section flows out of the front end of the cutting implement (25) via a center hole in a tool holder (8), the mist outlet member is nonrotatably formed with a mist guide extension (24) for allowing a mist outlet passageway (e1) thereof to extend a region in the vicinity of the cutting implement rear end positioned in the center hole in the tool holder.

Description

Description Spindle device of machine tool Technical field

The present invention relates to a spindle device of a machine tool in which a cutting fluid mist is generated inside a spindle. Background art

A mist generating portion is provided in the center hole of the spindle driven to rotate, and cutting fluid mist ejected from a non-rotating mist outlet member, which is a part of the mist generating portion, receives the mist generating member. There is a machine tool having a spindle device that is made to flow out of a tip opening of a cutting tool through a center hole of a tool holder that is also in front (for example, Patent No. 26877110). No., JP-A No. 11-231-6461).

In the above machine tool, the diameter of the mist passage from the front end of the mist outlet member to the rear end of the cutting tool changes relatively largely, and the mist passage rotates together with the main shaft. Pressure, speed change and centrifugal force in the gas passage may liquefy and may not flow out constantly from the opening at the tip of the cutting tool, resulting in poor machining quality and abnormal wear of the cutting tool. May occur.

An object of the present invention is to provide a spindle device of a machine tool capable of solving such a problem. Disclosure of the invention

To achieve the above object, according to the present invention, as described in claim 1, A straight supply pipe consisting of a double pipe consisting of an inner pipe and an outer pipe is inserted into a bore formed in the center of the driven spindle in a non-rotating state without contacting the spindle, and cutting fluid is injected into the inner pipe. Supplied to the outer tube, compressed air is supplied to the outer pipe, and the mist generating section is formed near the tip inside the main spindle. The mist outlet member is attached to the mist outlet member, and the mist outlet member is formed at its distal end into a small-length mist guide extension having a fixed length, and the mist outlet passage is formed through the mist guide extension through the tool holder. To reach the vicinity of the rear end of the cutting tool located in the center hole.

The cutting fluid mist generated at the mist generating section reaches the rear end of the cutting tool through the mist exit member and the mist guiding passage at the mist guiding passage, and then passes through the mist passage formed in the cutting tool. It flows out from the tip of the cutting tool. At this time, since the mist exit passage of the mist guide extension is in a non-rotating state, the cutting fluid mist passing through the mist exit passage is gas-liquid caused by centrifugal force caused by rotation of the main shaft. Therefore, the cutting fluid mist generated at the mist generating part reaches the rear end of the cutting tool from the mist outlet member in an appropriate mist state, and smoothly flows through the mist passage in the cutting tool. It flows and stably flows out continuously from the tip of the cutting tool.

The formation of the mist guide extension in the mist outlet member contributes to easily maintaining the mist outlet passage from the mist outlet member to the vicinity of the rear end of the cutting tool in a non-rotating state. This contributes to preventing the abrupt change in the cross-sectional area of the mist outlet passage from the outlet member to the vicinity of the rear end of the cutting tool with respect to a change in its longitudinal position. Here, the fact that the cross-sectional area of the mist outlet passage does not rapidly change in the length direction of the mist outlet passage contributes to the prevention of liquefaction due to the change in pressure of the cutting fluid mist in the mist outlet passage. It is.

The above invention can be modified as follows: an inner tube and an outer tube which are inserted in a non-rotating state into an inner hole formed in the center of the main shaft as described in claim 2; The outer pipe tip of the straight supply pipe consisting of a double pipe is extended, and the extension is formed into a small-length mist guide extension of a fixed length. Therefore, the mist outlet passage is formed in the mist guiding extension portion which reaches near the rear end of the cutting tool located in the center hole of the tool holder. In the present invention as well, substantially the same operation as the operation of the invention described in claim 1 can be obtained, the mist outlet member is shortened, and the position stability of the mist guide extension is reduced. It will improve.

Each of the above-described inventions may be embodied as follows.

That is, as set forth in claim 3, a cutting tool positioning member having a through hole formed in the center of the rear part of the tool holder, wherein the cutting tool is in contact with the rear end of the cutting tool to prevent rearward displacement of the cutting tool. Attach the stop means, and insert the front end of the mist guide extension into the through hole.

In this way, the tool position locking means conventionally provided in the tool holder allows the mist exit passage of the mist guiding extension to communicate with the mist passage at the rear end of the tool without any trouble. .

At this time, the fitting portion of the tool holder into the main shaft is formed in a straight cylindrical shape, and the tool position locking means is provided inside the fitting portion, and the tool position locking means is misted into the front-rear through hole. The insertion length of the guide extension may be shorter than the length of the main shaft insertion portion. In this way, when the tool holder is attached to and detached from the spindle, the misguide extension is extended while the tool spindle insertion portion is guided densely in the center hole of the spindle. The mist guiding extension and the blade position locking means can be prevented from coming into contact with each other without any precautions, because the mist guiding extension portion and the blade position locking means come into and out of the front and rear holes of the blade position locking means. '

Further, as described in claim 4, each of the passages formed in the mist outlet member and the mist guide extension portion is made linear, and both of them have the same diameter. In this way, the cross-sectional area of the mist outlet passage is reduced. It does not significantly change in relation to the change in the longitudinal position of the passage, and the mist outlets of both the mist outlet member and the mist guide extension are straight, so that the mist Pressure fluctuations of the cutting fluid mist flowing in the outlet passage are less likely to occur, and the liquefaction is suppressed as described above. BRIEF DESCRIPTION OF THE FIGURES

FIG. 1 is a side view sectional view showing a spindle device of a machine tool according to one embodiment of the present invention, FIG. 2 is a side view sectional view showing a main part of the spindle device, and FIG. 3 is a modified example of the spindle device. FIG. 4 is a side view sectional view showing a main part of this modified example. BEST MODE FOR CARRYING OUT THE INVENTION

The present invention will be described in more detail with reference to the accompanying drawings. In the figure, reference numeral 1 denotes a main body frame of a main spindle device, in which a main shaft 2 is rotatably inserted at a predetermined position via ball bearings 3a and 3b.

At this time, 4 is a ring member fixed to the front end face of the main body frame 1 by porto, 5 is an input gear detached to the rear end of the main shaft 2 and fixed to a key, and 6 is screwed to the rear end of the main shaft 2. A nut body 7a and 7b for restricting the input gear 5 from coming off from the main shaft 2, and cylindrical spacers 7a and 7b for restricting the front and rear positions of the ball bearings 3a and 3b.

The main shaft 2 has a fitting hole 2a having a straight cylindrical female surface at the center of the tip, and three straight center holes 2b, 2c, and 2d of different diameters are continuously formed in the fitting hole 2a. It has been formed. Reference numeral 8 denotes a tool holder mainly composed of the holder main body 8a, and a main shaft internal fitting portion 8b forming a part of the holder main body 8a is internally fitted in the fitting hole 2a of the main spindle 2.

9 is rotatably supported by the body frame 1 and spouts with the input gear 5 The transmission gears receive rotation from a motor (not shown).

Reference numeral 10 denotes an additional frame provided behind the spindle 2. The additional frame 10 is provided with a through hole 10a at a portion immediately behind the spindle 2 and the through hole 10a is provided with a supply path member 1. The first cylindrical fitting portion 11a is internally fitted, and the rear portion of the supply path member 11 is bolted to the additional frame 10. At the rear end of the supply path member 11, a connection fitting 12 for connecting the compressed air supply line 12a and a connection fitting 13 for connecting the cutting fluid supply line 13a are screwed. Is being worn. In the center hole 2d of the main shaft 2, a straight supply pipe 14 that is not in contact with the main shaft 2 is inserted in a non-rotating state concentrically with the straight center hole 2d. This straight supply pipe 14 is formed as a double pipe consisting of an inner pipe 14a and outer pipes 14 and b. The inner hole of the inner pipe 14a is formed as a liquid passage a, and the outer pipe 1 A compressed air passage b is provided between 4b and the inner pipe 14a.

The front portion of the outer tube 14b is formed with a small-diameter portion c1, a ball bearing 15 for rotatably supporting the small-diameter portion c1 between the small-diameter portion c1 and the center hole 2c, and a small-diameter portion. A ring-shaped seal member s is provided on the front side of the ball bearing 15 between the portion c 1 and the center hole 2 b. The rear end of the inner pipe 14a is inserted into the center hole of the connection fitting 13 in a liquid-tight manner, and the front end of the inner pipe 14a is not rotated to the tip of the straight supply pipe 14. It is liquid-tightly connected to the rear of the mist generating section 16 fixed in this state. At this time, an isolating ring plate r is provided between the ball bearing 15 and the ring-shaped seal member s to prevent them from directly contacting the inner ring of the ball bearing 15.

The mist generating section 16 forms the cutting fluid supplied through the fluid passage a into a mist by the compressed air supplied through the compressed air passage b, which will be described in detail with reference to FIG. It is as follows.

That is, a cylindrical cutting fluid ejection nozzle member 17 is provided, and the rear end of the nozzle member 17 is fitted inside the front end of the inner pipe 14a. The cutting fluid jet nozzle member 17 is a cylindrical member having a center hole 17a facing the front and back, and a tapered circle at the front. It has a conical male surface part 17b, the center hole 17a at the rear end part is made slightly larger in diameter, and one end of the coil spring 18 is inserted into this part in a state where forward movement is restricted. I do it.

A cylindrical member 19 for the seat is provided at a position on the rear side of the cutting fluid jetting nozzle member 17 at the inner hole at the front end of the inner pipe 14a, and the coil spring 18 is provided at a seat portion at the front end of the cylindrical member 19. A ball valve 20 to be pressed, and a valve body integrated with a cutting fluid ejection nozzle member 17 for externally fitting to the cylindrical portion 19 so as to surround the circumference of the ball valve 20. A cutting fluid outflow regulating valve means 22 comprising the guide cylinder member 21 is formed. Also, a mist outlet member 23 is externally fitted to the front small diameter portion of the cutting fluid jet nozzle member 17, and the mist outlet member 23 is airtightly sealed by an O-ring into the small diameter portion of the outer pipe 14b. It is fitting.

The mist outlet member 23 is formed as follows: it has a tapered male surface portion 23a which is tapered forward, and the tapered male surface portion 23a is a small diameter portion c of the outer tube 14b. The forward movement is restricted by contacting the tapered female surface portion c 2 formed in the inner hole 1 and the front portion of the cutting fluid jetting nozzle member 17 is attached to the rear diameter large inner hole portion d. The front end of the conical male surface portion 17b is located at the center of the mist exit passage el at the center of the mist exit passage el while the front inner small-diameter hole e1 is made airtight. At the same time, a compressed air groove-shaped passage f with a narrow width in the front-rear direction is formed on the outer peripheral surface, and this passage f is formed by the outer peripheral surface of the conical male surface portion 17 b and the large-diameter rear hole d. The compressed air in the compressed air passage b is communicated with the space, and the compressed air groove-shaped passage f, the rear large-diameter inner hole d surrounding the conical male surface 17 b Its to have been made as communicating mist outlet passage e l, the e 2 front through the annular gap between the tip and the mist outlet passage e 1 of the conical male surface part 1 7 b.

The mist outlet member 23 is provided with a mist guide extension 24 formed as a relatively small-diameter straight cylindrical member, and the extension 24 is a tapered female portion at the tip of the outer tube 14b. Refers to the part on the front side of the surface part c 2, and the front center hole of the tapered female surface part c 2 Through the cantilever. The mist outlet passage e2 formed at the center of the mist guide extension 24 and the mist outlet passage e1 of the mist outlet member 23 are linear, and these mist outlet passages are formed. The diameters of e 1 and e 2 are set to be substantially constant at the arbitrary positions in the front-rear direction.

The tool holder 8 has a collet chuck 26 for fastening the peripheral surface of the cutting tool 25 positioned at the front of the holder body 8a to a fixed state, and has a thread g at the center. A center hole h is formed, and a cutting tool position locking means 27 is formed in the center hole h.

The cutting tool position locking means 27 is inserted into the center hole h, and the cutting tool locking member 28 is brought into contact with the rear end face of the cutting tool 25. A male screw member 29 that can change and adjust the front-back position of the stop member 28; and a through-hole for front-rear direction is provided at the center of the cutting tool locking member 28 and the male screw member 29. i1, i2 are formed. The distal end of the mist guide extension 24 is inserted into the through holes i 1 and i 2, and the insertion length is shorter than the front-rear length of the main shaft insertion portion 8 b. .

At this time, the through-holes i 1 and i 2 of the cutting tool locking member 28 have a small diameter as close as possible to the mist exit passage e 2 of the mist guide extension 24 and a tapered conical female surface portion. It is connected to the rear end of the cutting tool 25 via j and the flow distance of the cutting fluid mist is made as short as possible.

The collet chuck 26 includes a collet 30 surrounding the peripheral surface of the cutting tool 25 and an operation nut portion 31 for displacing the collet 30 in the front-rear direction.

Further, the cutting tool 25 has a straight mist passage k at the center, and the mist passage k is branched at the front end into a bifurcated shape so that the center of the specific diameter of the tip end surface of the cutting tool 25 is adjusted. The rear end is communicated with an outlet opening m formed at the center of the rear end face of the cutting tool 25. In the example shown, The cutting tool 25 is a swist drill, but is not limited to this. Next, an example of use of the spindle device configured as described above and the operation thereof will be described. The attachment / detachment of the cutting tool 25 is performed by rotating the operating nut 31 of the collet chuck 26 to the relaxation side to displace the collet 30 forward, thereby expanding the center hole p of the collet 30. It becomes a diameter state. Thereafter, insert the rear part of the blade 25 into the center hole p of the collet 30 to bring the rear end of the blade 25 into contact with the front surface of the blade locking member 28 to maintain this contact state. Then, the operating nut 31 is rotated to the fastening side to displace the collet 30 rearward. As a result, the center hole p of the collet 30 is reduced in diameter by the wedge action of the tapered surface, and the cutting tool 25 is fixed to the holder body 8a in a fastening manner.

When changing the front / back position of the blade 25 with respect to the holder body 8a, the coupling between the spindle 2 and the tool holder 8 is released, the tool holder 8 is removed from the spindle 2, and then the blade 25 is removed. The male screw member 29 is rotated as needed under the condition or under the condition that the blade tool 25 can be moved back and forth. As a result, the male screw member 29 is displaced in a specific direction related to the rotational operation direction by the screw feed action, and the position of the blade engaging member 28 with respect to the holder main body 8a is adjusted. Thereafter, the cutting tool 25 of the tool holder 8 is fixed to the holder body 8a in a state where the rear end face thereof is in contact with the front end face of the cutting tool locking member 28, and the tool holder in this state is set. Attach 8 to spindle 2.

When the tool holder 8 is attached to and detached from the main spindle 2, the main shaft insertion portion 8 b of the holder main body 8 a is pulled out from the insertion hole 2 a of the main spindle 2 or inserted into the insertion hole 2 a of the main spindle 2. At this time, the main shaft 2 fitting portion 8b is guided in the accurate front-rear direction around the main shaft 2 by the fitting hole 2a of the main shaft 2, so that the mist guiding extension portion 24 is made transparent through the blade position locking means 27. The phenomenon of contact with the holes i 1 and i 2 is avoided.

Next, the situation when machining a workpiece will be described. The rotation of the motor is transmitted via the transmission gear 9 and the input gear 5 and rotates at a specific position on the main body frame 1 while being supported by the ball bearings 3a and 3b. Then, the rotation of the spindle 2 is transmitted to the cutting tool 25 via the holder body 8a and the collet chuck 26, and at this time, the cutting tool position locking means 27 is also integrated with the holder body 8a. Rotated.

On the other hand, the straight supply pipe 14 has its front end supported by the ball bearings 15 and its rear end supported by the same frame as the additional frame 10, so that the straight supply pipe 14 is kept in a non-rotating state even while the main shaft 2 is rotating. Therefore, the mist generating section 16 provided integrally with the straight supply pipe 14 is also held in a non-rotating state. At this time, the ring-shaped seal member s hermetically closes the space between the center hole 2b of the main shaft 2 in the rotating state and the tip of the outer tube 14b in the non-rotating state.

Then, compressed air and cutting oil are supplied to the supply path member 11 from the compressed air supply line 12a and the cutting fluid supply line 13a, whereby the compressed air is supplied to the outer pipe 14b and the inner pipe 14b. The gas is ejected into the mist outlet passage e1 of the mist outlet member 23 via the compressed air passage b between the pipes 14a, the compressed air grooved passage f, and the space surrounding the conical male surface portion 17b. The cutting fluid is in the inner pipe 14a, the liquid passage a, the central hole of the sheet cylindrical member 19, the space around the ball valve 20, the central hole 1 of the cutting fluid jet nozzle member 17 The mist is ejected to the center of the mist exit passage e1 of the mist exit member 23 via 7a.

The cutting fluid jetted into the mist outlet passage e1 mixes the compressed air jetted into the mist outlet passage e1 with their flow energy, so that fine cutting fluid particles are uniformly distributed in the air. After that, the cutting fluid mist is dispersed in the mist guide extension part 24, the mist exit passage e2 of the mist guide extension part 24, the through hole i1 of the cutting tool locking member 28, and the cutting fluid mist of the cutting tool 25. Through the mist passage k, it is discharged from the outlet openings m, m at the tip of the cutting tool 25. The cutting fluid mist that has flowed out in this way acts to lubricate and cool the frictional portion between the cutting tool 25 and the work. During the flow of the cutting fluid mist in the main spindle 2 and the tool holder 8 described above, the cutting fluid mist flowing out of the mist outlet extension 24 may be mistaken for the through holes i 1 and i 2 of the tool position locking means 27. The guide guide extension part 24 tries to leak into the atmosphere through the annular gap formed between the guide holder extension part 24 and the outer peripheral surface.However, the outflow from the back of the insertion hole 2a of the spindle 2 to the tool holder 8 and the spindle It is prevented by the hermetic connection with 2 and the outflow from the back of the insertion hole 2a to the rear is prevented by the ring-shaped seal member s.

As described above, the cutting fluid mist flowing out from the outlet opening m, m at the tip surface of the cutting tool 25 tends to be liquefied due to pressure change, speed change, centrifugal force, etc., but the mist outlet member 23 The mist exit passage e 1 and the mist guidance extension e 2 of the mist guidance extension 24 are straight, with almost no change in diameter in the front-rear direction. Since the mist outlet passage e2 of FIG. 4 reaches the vicinity of the rear end of the cutting tool 25 and the mist outlet member 23 and the mist guide extension 24 are kept in a non-rotating state, cutting is performed. The liquid mist is prevented from undergoing a large change in pressure and speed, and is not subject to the centrifugal force caused by the rotation of the main shaft 2.Therefore, the liquid mist is located between the mist generating section 16 and the vicinity of the rear end of the cutting tool 25. The liquefaction of the cutting fluid mist is effectively suppressed.

Also, the cutting fluid mist flowing out of the mist guide extension portion 24 flows into the mist passage k of the cutting tool 25 through the through hole i1 of the cutting tool locking member 28, and at this time, the through hole i (1) S mist guide extension (2) A small diameter as close as possible to the mist exit passage (2) of (4), and it is connected to the inlet opening (n) on the rear end face through the tapered conical female surface (j). In addition, the flow distance of the cutting fluid mist is shortened, so that the cutting fluid mist is prevented from sudden pressure changes and speed changes, and is not subjected to a large centrifugal force. It takes time, and accordingly, liquefaction in the cutting tool locking member 28 is also effectively suppressed.

Further, since most of the mist passage k of the cutting tool 25 is located at the center of the cutting tool 25, the cutting fluid mist flowing in the mist passage k is formed by the mist passage k. Compared to a case formed at a location away from the center, the centrifugal force is relatively small, and therefore, the cutting fluid mist is effectively suppressed from liquefaction even in the cutting tool 25.

Further, the mist passage k is branched into two at the front end thereof, and outlet openings m, m are formed on both sides of the center of the specific diameter of the distal end surface of the cutting tool 25, so that these outlet openings m, m The cutting fluid mist that has flowed out of the tool is evenly supplied to the entire tip surface of the cutting tool 25 and is supplied with effective lubrication.

The above embodiment can be modified as shown in FIGS. 3 and 4, that is, in this modification, instead of forming the mist guiding extension 24 on the mist exit member 23, the mist exit member The mist guide extension 24 is formed by extending the distal end of the outer tube 14b, which is the same as 23 and is held in a non-rotating state. The rest of the structure is essentially the same as the previous one. In FIGS. 3 and 4, substantially the same parts as those in the previous embodiment are denoted by the same reference numerals.

According to the present invention configured as described above, the mist exit passage of the mist guide extension is in a non-rotating state, and the mist exit passage is in a non-rotating state from the mist exit member to the vicinity of the cutting tool rear end. The centrifugal force due to the rotation of the main spindle acts on the cutting fluid mist flowing from the mist outlet member to the vicinity of the rear end of the cutting tool to effectively liquefy the cutting fluid mist. As a result, the cutting fluid mist generated by the mist generating part can reach the rear end of the cutting tool from the mist exit member in an appropriate mist state, and can smoothly pass through the mist passage in the cutting tool, and It can be discharged continuously and stably from the opening.

Also, by forming the mist guide extension on the mist exit member, the mist exit passage from the mist exit member to the vicinity of the rear end of the cutting tool can be held in a non-rotating state by a simple structure. In addition, the cross-sectional area of the mist exit passage from the mist exit member to the vicinity of the rear end of the cutting tool is abrupt with changes in its longitudinal position. A structure that does not change can be easily realized, and The steep cross section of the mist exit passage Liquefaction caused by a change in the pressure of the cutting fluid mist in the mist outlet passage due to a drastic change is suppressed.

According to the second aspect of the present invention, the same effect as above can be obtained, and in addition to the fact that the mist guide extension is integrated with the outer tube, its position can be made stable, and The front-rear length of the outlet member can be reduced.

According to the invention described in claim 3, the tool position locking means conventionally provided in the tool holder allows the mist exit passage of the mist guide extension portion and the mist passage at the rear end of the tool to be formed. Can be communicated with the state in which the liquefaction of the cutting fluid mist is suppressed during the cutting.

According to the invention described in claim 4, the liquefaction of the cutting fluid mist flowing in the mist outlet passage can be suppressed by making it less likely to cause pressure fluctuation.

Claims

The scope of the claims

1. From the double pipe of the inner pipe (14a) and outer pipe (14b) in a non-rotating state that does not contact the main shaft, into the bore formed in the center of the main shaft (2) that is driven to rotate Insert the straight supply pipe (14), supply the cutting fluid to the inner pipe (14a), and supply the compressed air to the outer pipe (14b). In the spindle device of the machine tool in which the mist generating part (16) is formed, the mist outlet member (23) is attached in a non-rotating state surrounding the mist generating passage (e1) of the mist generating part. The mist outlet member has a distal end formed in a small-length mist guide extension (24) having a constant length, and a mist exit passage (el) is formed through the mist guide extension (24). A spindle device for a machine tool, characterized in that the cutting tool (25) is located in the center hole of the tool holder (8) and reaches near the rear end.

2. The inner pipe (14a) and the outer pipe (14b), which are not in contact with the spindle, are inserted into the bore formed in the center of the spindle (2) driven by rotation. Insert the straight supply pipe (14), supply the cutting fluid to the inner pipe (14a), and supply the compressed air to the outer pipe (14b). In the spindle device of the machine tool in which the mist generating part (16) is formed, the outer pipe (14b) of the straight supply pipe is placed in a state surrounding the mist outlet passage (e1) of the mist generating part. The distal end is extended, and the extended portion is formed into a small-length mist guiding extension (24) having a constant length. The mist guiding passage (elt) is passed through the mist guiding extension (24). ) To reach the vicinity of the rear end of the cutting tool (25) located in the center hole of the tool holder (8). .

3. Drill through holes (i1, i2) in the center of the center of the tool holder (8), which are to be in contact with the rear end of the tool to prevent rearward displacement of the tool (25). The cutting tool position locking means (27) provided is attached, and the front end of the mist guiding extension (24) is inserted into the through hole (i1, i2). Clause 1 or 2. The spindle device of the machine tool according to 2.

4. Make each of the passages (e1, e2) formed in the mist outlet member (23) and the mist guide extension (24) straight, and make them substantially the same. The machine tool according to any one of claims 1 to 3, wherein the machine tool has a diameter.