JP3064423U - Machine rotary axis device for machine tools - Google Patents

Abstract

PROBLEM TO BE SOLVED: To prevent the mist cutting fluid from flowing out of the hollow portion T to the atmosphere or flowing into the lubricating oil space J, waste the cutting fluid and lubricate the lubricating oil space J. Prevents oil deterioration.
In addition, the liquefaction of the mist cutting fluid is suppressed, the responsiveness to the start and stop commands for jetting the mist cutting fluid is improved, and the mist cutting fluid is jetted from the tip of the cutting tool 25 stably. SOLUTION: A cutting fluid supply pipe 26 is provided in a non-rotating state at a rotation center part inside a work rotation shaft 11, and a front end of the cutting fluid supply pipe 26 is opened to a hollow portion T at a front part of the work rotation shaft 11. In the machine tool provided with a relatively small diameter passage hole c1 extending from the front end surface of the hollow portion T to the base end of the cutting tool 25 fixed to the front end of the machining rotary shaft 11, the cutting fluid supply is performed. The front end of the pipe 26 and the opening of the starting end of the passage hole c1 are relatively rotatably communicated via a cylindrical member 29 disposed in the hollow portion T.

Description

[Detailed description of the invention]

[0001]

[Technical field to which the invention belongs]

 The present invention relates to a machine rotary shaft (spindle or spindle) device of a machine tool that uses mist cutting fluid.

[0002]

[Prior art]

 In machining with a machine tool, a large amount of cutting fluid is supplied to the machining part to cool and lubricate the workpiece and cutting tools, or to remove chips, but this causes environmental pollution and human health due to the cutting fluid. In addition to problems such as the adverse effects of oil removal, large costs associated with waste oil treatment of cutting fluid, reduction of the tool life due to overcooling of the workpiece, and excessive wear of the cutting tool due to sliding wear during fine cutting of the cutting tool. Since a large amount of cutting fluid adheres to the chips, it is necessary to separate the cutting oil adhering to the chips during treatment and reuse. In order to solve these problems, in recent years, machine tools that perform so-called dry cutting, in which an extremely small amount of cutting fluid is atomized and supplied to a processing portion, and cuts, have appeared.

[0003]

[Problems to be solved by the invention]

 The present applicant has already proposed the following as a machine tool for performing dry cutting. That is, a cutting fluid supply pipe is provided in a non-rotating state at an inner rotation center of a machine rotating shaft such as a main shaft or a spindle shaft, and a front end of the cutting fluid supply pipe is opened in a hollow portion of a front end of the machine rotating shaft. A relatively small-diameter passage hole extending from the front end surface of the hollow portion to the base end of the cutting tool fixed to the tip of the work rotary shaft is provided. According to this, since the cutting fluid supply pipe is in a non-rotating state, the mist cutting fluid flowing in the inside thereof is not liquefied due to centrifugal force, and the mist cutting fluid is more smoothly than the conventional one. It reaches the cutting tool.

However, in this type of machine tool, the mist-like cutting fluid that has reached the hollow portion flows to the distal end side of the main shaft or the spindle shaft through the gap between the parts and flows out to the atmosphere, or the main shaft or the spindle shaft Flows into the lubricating oil space due to the flow of the cutting fluid into the air, and the outflow of the cutting fluid into the atmosphere wastes the cutting fluid, and the cutting fluid flows into the lubricating oil space. Changes the properties of the lubricating oil and reduces its lubricating performance. If the hollow part has a relatively large diameter, the cutting fluid that has reached this hollow part will be liquefied to some extent, and this liquefaction will result in stable supply of the cutting fluid and ejection of the cutting fluid. This is a cause of impairing the responsiveness of starting and stopping operation. . An object of the present invention is to provide a machine rotary shaft device of a machine tool capable of solving such a problem.

[0005]

[Means for Solving the Problems]

 In order to achieve the above object, in the present invention, a cutting fluid supply pipe is provided in a non-rotating state at a center of rotation in a machine rotary shaft such as a spindle or a spindle, as described in claim 1, and the cutting fluid is provided. A relatively small-diameter passage hole that opens the front end of the supply pipe into the hollow part at the front of the rotary shaft, and extends from the front end face of this hollow part to the base end of the cutting tool fixed to the front end of the rotary shaft. In a machine tool provided with c1, a front end of the cutting fluid supply pipe and a starting end opening of the passage hole c1 are relatively rotatably communicated via a cylindrical member disposed in the hollow portion. And At this time, the machine tool may have a plurality of machine rotation axes.

According to this, the inner hole of the cylindrical member guides the mist cutting fluid from the cutting fluid supply pipe to the passage hole, and the mist cutting fluid is prevented from flowing into the hollow portion outside the cylindrical member. This restricts the outflow of the atomized cutting fluid to the atmosphere and the inflow into the lubricating oil space. In addition, since the inner hole of the cylindrical member is smaller than the diameter of the hollow portion, the mist-like cutting fluid passing through this inner hole is reduced in the effect of the centrifugal force and liquefaction is suppressed. As a result, the mist cutting fluid starts and stops with good responsiveness to the start and stop commands of the blasting operation, and blasts with a stable force.

Specifically, the following is performed. That is, as described in claim 3, a cylindrical member is externally fitted to the front end of the cutting fluid supply pipe so as to be slidably displaceable within a certain range in the direction of the center of rotation of the machine rotating shaft, and the cylindrical member is formed in the hollow portion. An elastic member 30 for urging toward the front end face side is provided. According to this, the front end surface of the cylindrical member is pressed against the front end surface of the hollow portion by the elastic force of the elastic member 30 so as to be in close contact with the front end surface of the hollow portion. In a state where leakage of the mist-like cutting fluid is suppressed so as to be relatively rotatable.

In this case, as described in claim 4, between the outer peripheral surface of the front end portion of the cutting fluid supply pipe and the inner peripheral surface of the cylindrical member, these are rotatable relative to each other and freely displaceable in the direction of the center of rotation of the rotary shaft. The elastic member 30 is disposed in a non-contact state with the cutting fluid supply pipe. According to this, the bearing member makes the relative rotation of the cylindrical member and the cutting fluid supply pipe smooth, and the elastic member 30 is rotated by the non-rotating cutting fluid supply pipe, which is rotated cognately with the work rotating shaft. It will not be suppressed.

The following may be used instead of the third and fourth aspects. That is, as described in claim 5, a cylindrical member having a relatively larger diameter is extrapolated to the front end surface of the cutting fluid supply pipe, and the outer peripheral surface of the cylindrical member is attached to the inner peripheral surface of the hollow portion. The rotation of the machine rotary shaft is guided so as to be freely slidable within a certain range in the center direction, and a gap between the outer peripheral surface of the cutting fluid supply pipe and the inner peripheral surface of the cylindrical member is closed in a liquid-tight manner by a seal member 301. An elastic member for urging the cylindrical member toward the front end face of the hollow portion is disposed in a non-contact state with the cutting fluid supply pipe. According to this, since the cylindrical member is guided on the peripheral surface of the hollow portion, it can be sufficiently separated from the outer peripheral surface of the cutting fluid supply pipe, and contact between the cylindrical member and the cutting fluid supply pipe is reliably avoided. You. The gap between the cylindrical member and the cutting fluid supply pipe is closed in a liquid-tight manner with the seal member 301 allowing relative rotation thereof.

[0010] Furthermore, the invention may be modified as described in claim 6 instead of claim 5, that is, the cutting fluid supply pipe can be freely displaced back and forth within a certain range in the direction of the center of rotation of the work rotary shaft. At the same time, the cylindrical member is urged forward by the elastic member 403, and the cylindrical member is mounted on the front end of the cutting fluid supply pipe via the bearing member 406 so that only relative rotation is possible. According to this, the elastic member 403 presses the front end face of the cylindrical member in close contact with the front end face of the hollow portion via the cutting fluid supply pipe, and the bearing member 406 connects the cylinder member and the cutting fluid supply pipe. Smooth relative rotation of.

[0011] According to a seventh aspect of the present invention, a portion of the inner hole of the cylindrical member located between the front end of the cutting fluid supply pipe and the front end surface of the hollow portion is provided outside the front end of the cutting fluid supply pipe. Approximately match the diameter. According to this, since the diameter of the inner hole of the cylindrical member is relatively small, the mist cutting fluid flowing in the cylindrical member is less affected by the rotation of the cylindrical member, and liquefaction is effectively suppressed. Becomes

[0012] Further, as described in claim 8, the inner hole of the cylindrical member is externally fitted to the front end portion of the cutting fluid supply pipe in a roughly dense state, and the densely externally fitted part is provided at the location. A labyrinth structure (for example, an annular groove m1 provided in the inner hole of the cylindrical member 29) is formed so as to restrict the gas flow in the direction of the rotation center of the rotary shaft. According to this, while the cylindrical member and the cutting fluid supply pipe are kept in a non-contact state, the outflow of the liquid cutting fluid through these gaps can be regulated.

[0013] Further, as described in claim 9, a relatively narrow passage groove m2 is formed over the entire thickness of the front end surface of the cylindrical member. According to this, when the front end surface of the cylindrical member is in close contact with the front end surface of the hollow portion, the passage groove m2 allows a very small amount of the liquid cutting fluid in the cylindrical member to pass outside the cylindrical member. The mist cutting fluid passing through the passage groove m2 acts as a lubricant for the relative rotation between the front end surface of the cylindrical member and the front end surface of the hollow portion.

[0014]

FIG. 1 is a sectional side view showing a spindle shaft device of a machine tool according to an embodiment of the present invention, FIG. 2 is a diagram showing an xx portion of FIG. 1, and FIG. FIG. 4 is an enlarged sectional view of the shaft device, and FIG. 4 is a view showing a main part of the spindle shaft device of FIG.

In these figures, 1 is a bed, 2 is a movable table operably mounted in the front-rear direction f1, f2 via a guide track 1a on the upper surface of the bed 1, and 3 is a movable table 2. Is a multi-axis spindle head fixed on the upper surface of the head.

The specific configuration of the multi-axis spindle head 3 will be described as follows. That is, a head frame 4 fixed to the movable base 2 is provided, and a spindle portion 5 having a rear case frame 5a and a front case frame 5b is provided on the front surface of the frame 4.

The rear case frame 5 a has an upright wall 6 and a side wall 7. A supply path 6a through which mist-like cutting fluid is supplied from outside is formed in the wall of the upright wall 6, and a chamber wall member 8a for forming a closed chamber 8 is formed on the rear surface of the upright wall 6. The supply passage 6a is fixed to the bolt by the bolt, and communicates with the inside of the closed chamber 8.

The front case frame 5 b includes an upright wall 9 and a spindle case 10. The upright wall portion 9 is fixed to the rear case frame 5a by bolts, and a through hole 9a through which the spindle shaft 11 is inserted is provided for each spindle shaft 11 at the front part of the closed chamber 8 as shown in FIG. Is formed.

The spindle case section 10 includes a rectangular outer wall section 12 for surrounding a plurality of spindle shafts 11 and an intermediate wall section 13 for surrounding each spindle shaft 11 inside the outer wall section 12.

A circular through hole a corresponding to each spindle shaft 11 is formed on the front surface of the outer wall portion 12 as shown in FIG. 3, and the spindle shaft 11 is inserted into the front surface of each through hole a. The front end cover 14 is bolted.

Each of the spindle shafts 11 includes a large-diameter front portion 11a and a small-diameter rear portion 11b, and includes a front case 15 and a bearing 15 fitted in the through hole a and a bearing 16 fitted in the through hole 9a. It is rotatably supported at a certain position on the frame 5b. A straight hole b is formed at an axial position at the center of each spindle 11, and the front portion of the hole b is formed with step-shaped large-diameter portions b1 and b2.

Here, 17 is a cover member for covering the front surface of the front end face cover 14, which is fixed to the spindle 11, and 18 is an oil seal fitted inside the front end face cover 14. .

Reference numeral 20 denotes a cutting tool holding cylinder member fitted and fixed to a specific position of the large diameter portion b1 of the hole b. The cutting tool holding cylinder member 20 has slits s, s formed in opposing peripheral wall front and rear portions. At the same time, a tapered hole 20a is formed at the front of the inner peripheral surface, a female screw 20b is formed at the rear of the inner peripheral surface, and a fastening nut 22 for pushing the collet 21 fitted in the tapered hole 20a is formed at the outer periphery of the front end. A male screw (not shown) to be screwed is formed. A pair of cutting tool stoppers 23a, 23b formed as male threads are screwed into the female screw 20b of the cutting tool holding cylinder member 20, and the opposite ends are connected to the slits s, s between the stoppers 23a, 23b. The combined detent member 24 is positioned.

Reference numeral 25 denotes a cutting tool located in the collet 21. A rear end of the cutting tool 25 is in contact with a front end of the cutting tool stopper 23a to restrict rearward displacement. The cutting tool 25 is fixed to the cutting tool holding cylinder member 20 by the fastening nut 22 being tightened and the collet 21 being displaced to the rear side of the tapered hole 20a. The fixing position of the cutting tool 25 is as follows. After the cutter stopper 23a is loosened, the position of the other cutter stopper 23b is appropriately displaced, and the blade stopper 23a is re-tightened to be displaced back and forth. This contributes to preventing the other blade tool stopper 23b from rotating together when tightening. In addition, passage holes c1, c2, c3, c4, and c5 are formed at respective axial positions at the central portions of the blade holding cylinder member 20, the blade stopper 23b, the rotation preventing member 24, the blade stopper 23a, and the blade 25. is there.

Inside the hole b of the spindle shaft 11, a straight cutting fluid supply pipe 26 smaller than the diameter of the hole b is provided concentrically with the spindle shaft 11. The rear end of the supply pipe 26 is located in a hole 6b provided in the upright wall section 6 of the rear case frame 5a, and is fixed to the upright wall section 6 via coupling members 27a and 27b, packing, and the like, and hermetically sealed. The front end is located in a hollow portion T formed between the rear end of the large diameter portion b1 of the hole b and the rear end surface 20c of the cutting tool holding member 20, as shown in FIG. Have been. A bearing (roller bearing) 28 is provided between the front end of the cutting fluid supply pipe 26 and the large-diameter portion b2. The bearing 28 allows the smooth rotation of the spindle 11 to be controlled by the cutting fluid supply pipe 26. It contributes to a structure that is not inhibited.

The front end of the cutting fluid supply pipe 26 and the start end opening of the passage hole c1 formed in the front end surface of the hollow portion T (that is, the rear end surface 20c of the blade holding cylinder member 20) are inside the hollow portion T. Are communicated via a cylindrical member 29 disposed at the bottom, and the specific structure is as follows.

That is, a step d1 is provided at the front end of the cutting fluid supply pipe 26 to form a small-diameter portion 26a, and a cylindrical member 29 is externally fitted to the small-diameter portion 26a so as to be able to be displaced in a substantially dense and longitudinal direction. Let me do it. The cylindrical member 29 has a flange portion 29a formed at the rear end of the outer periphery, an annular groove m1 formed at an appropriate interval in the front-rear direction of the inner peripheral surface, and a front end surface extending from the inside to the outside of the peripheral wall. The formed passage groove m2 is formed. A compression spring 30 is externally fitted to the small diameter portion 26a of the cutting fluid supply pipe 26 between the flange portion 29a of the cylindrical member 29 and the step d1. Due to the elasticity, the distal end surface of the cylindrical member 29 is brought into close contact with the rear end surface 20c of the cutting tool holding cylindrical member 20.

On the other hand, a ring plate 31 is disposed at the rear end of the large-diameter portion b 1, and a cylindrical member 29 is inserted into an inner hole 31 a of the ring plate 31 so as to be movable back and forth. The diameter of the inner hole 31a is smaller than the diameter of the flange portion 29a, and regulates the forward displacement of the tubular member 29 before it comes out of the small diameter portion 26a. An annular groove m3 is formed on the peripheral surface of the large-diameter portion b1 on the front side of the ring plate 31, and a retaining ring 32 for restricting the forward movement of the ring plate 31 is fitted into the annular groove m3. .

Each spindle shaft 11 is driven by a main shaft driving motor 33 mounted on the head frame 4 as shown in FIG. 1, and specifically, the following is performed. I have. That is, the driving shaft 34 coupled to the output shaft of the main shaft drive motor 33 is rotatably provided at a fixed position inside a lubricating oil space J surrounded by the front and rear case frames 5a and 5b, A driving gear 35 is formed at the tip of the driving shaft 34. On the other hand, in the lubricating oil space J, a driven gear 36 is fixed at the rear end of each spindle 11, and the driven gear 36 and the driving gear 35 are linked by a gear train including a plurality of intermediate gears 37. Tie. The lubricating oil space J must be lubricated by the lubricating oil stored inside the lubricating oil space J.

In front of the multi-axis spindle head 3 configured as described above, a workpiece fixing table 38 which is arranged at a fixed relative position to the bed 1 is provided. At this time, the surrounding frame member 39 is fixed around the workpiece support surface 38a of the workpiece fixing base 38.

Numeral 40 denotes a cover device which is attached to the front and rear directions f1 and f2 so as to be extendable and contractable, and is in close contact with the surrounding frame member 39 at the time of processing the workpiece, in front of the workpiece w and the multi-axis spindle head 3. The part is enclosed so that only the lower side is open.

Reference numeral 41 denotes a hopper-type guide path for guiding chips and cutting fluid, which is disposed so as to cover the lower surface side of the cover device 40. Reference numeral 42 denotes a cutting fluid that has dropped from the hopper-type guide path 41. This is a guide surface device for guiding the user to an appropriate place.

In FIG. 3, reference numeral 43 denotes a cutting fluid atomizing device for generating an atomized cutting fluid, which includes a compressed air supply pipe 44, a filter 43a, a pressure adjusting device 43b, an atomizing device 43c, and a cutting fluid delivery pipe. 45. The cutting fluid delivery pipe 45 is communicated with the supply path 6a through a pipe 46, and an electromagnetic valve 47 that is opened and closed in a timely manner by a controller (not shown) is provided in the pipe 46.

Next, a description will be given of an example of use of the product of this embodiment configured as described above and its operation. The movable table 2 is moved rearward from the position in FIG. 1 to f2, and the workpiece w is fixed to the workpiece support surface 38a of the workpiece fixing table 38. Then, the spindle drive motor 33 is operated. Thus, the rotation of the motor 33 is transmitted to the respective spindle shafts 11 via the gears 35, 37 and 36, and the respective spindle shafts 11 are guided by the bearings 15 and 16 to rotate smoothly. During this rotation, since the cutting fluid supply pipe 26 is fixed to the upright wall portion 6, it is kept in a non-rotating state.

On the other hand, the electromagnetic valve 47 is opened at an appropriate time. Thereby, the compressed air supplied from the compressed air supply pipe 44 flows in the atomizing device 43c, and the atomizing device 43c generates a mist-like cutting fluid by the principle of spraying.

The mist-like cutting fluid reaches the inside of the closed chamber 8 through the supply path 6a, is supplied from the inside of the closed chamber 8 into each of the cutting fluid supply pipes 26, and flows inward toward the front f1. It will be. Since the cutting fluid supply pipe 26 does not rotate, the mist-like cutting fluid flowing in the cutting fluid supply pipe 26 does not receive any centrifugal force caused by the rotation of the spindle shaft 11. Therefore, the liquefaction phenomenon due to the centrifugal force does not occur in the cutting fluid supply pipe 26, and the components are uniformly distributed without causing the component separation phenomenon due to the difference in the specific gravity of the components.

After the cutting fluid exits from the front end of the cutting fluid supply pipe 26, it passes through the inside of the cylindrical member 29 and reaches the passage hole c 1, and then sequentially passes through the other passage holes c 2, c 3, c 4, and c 5. The blade 25 is ejected from the tip in a relatively uniform distribution state. Further, a part of the mist cutting fluid passing through the inside of the tubular member 29, though a very small amount, flows out of the tubular member 29 through the passage groove m3. Under this condition, the movable base 2 is moved forward f1, and when this movement reaches a certain size, the cutting tool 25 reaches the workpiece w and processes it. Even during this processing, the mist-like cutting fluid is jetted from the tip of the cutting tool 25, so that even if the cutting tool 25 is in a state of processing a deep portion of the workpiece w, necessary parts are effectively lubricated. It will be.

In the above operation, the cylindrical member 29 tends to be suppressed from rotating together with the spindle shaft 11 by the compression spring 30 pressed against the non-rotating cutting fluid supply pipe 26. Therefore, the cylinder member 29 and the rear end surface 20c of the cutting tool holding cylinder member 20 may relatively rotate in a pressed state. At this time, since the mist cutting fluid passing through the passage groove m2 lubricates the relative rotation between the cylindrical member 29 and the rear end face 20c of the blade holding cylinder member 20, a large frictional resistance to the relative rotation is generated. It does not matter.

Further, the mist cutting fluid passing through the inside of the tubular member 29 tries to flow backward through the gap between the small diameter portion 26 a of the cutting fluid supply pipe 26 and the inner peripheral surface of the tubular member 29, or Attempts to flow out of the radial direction of the tubular member 29 from the contact point between the front end face and the rear end face 20c of the cutting tool holding tubular member 20 occur. However, the outflow to the rear side f2 is effectively restricted because the plurality of annular grooves m1 exerts a sealing effect by the expansion effect of the gas component of the atomized cutting fluid, and the radially outward direction is also restricted. The outflow is effectively restricted by the pressing of the front end face of the cylinder member 29 and the rear end face 20c of the blade holding cylinder member 20 by the compression spring 30.

By these restrictions, a large amount of the mist cutting fluid passing through the inside of the tubular member 29 is prevented from leaking into the hollow portion T outside the tubular member 29, and therefore, leaking into the hollow portion T. A large amount of the mist cutting fluid flows to the atmosphere side between the blade holding cylinder member 20 and the peripheral surface of the large-diameter portion b1 or a large amount of the mist-like cutting fluid obstructs the lubricating oil space J through the passage b. It does not flow into the country.

FIG. 5 is a side sectional view showing a spindle shaft device of a machine tool showing a first modification of the embodiment, and FIG. 6 is a sectional view showing a part of the spindle shaft device of FIG. In this example, the diameter of the cylindrical member 29 is larger than that of the cutting fluid supply pipe 26, and a flange 29a is formed in the middle of the front and rear length of the outer peripheral surface, and as shown in FIG. A roller bearing 201 as a bearing member is mounted between the small diameter portion 26 a of the cutting fluid supply pipe 26 and the inner peripheral surface of the cylindrical member 29. At this time, the roller bearing 201 is fixed in the cylindrical member 29, smoothing the relative rotation between the cylindrical member 29 and the cutting fluid supply pipe 26, and the longitudinal direction f1 between the cylindrical member 29 and the cutting fluid supply pipe 26. , F2 are allowed. A compression spring 30 is mounted between the flange 29a of the tubular member 29 and the rear end face d2 of the large-diameter portion b2, and the inner hole 31a of the ring member 31 is not enlarged according to the diameter of the tubular member 29. It is. In FIG. 5, reference numeral 202 denotes sealing means for closing a gap between the outer peripheral surface of the cutting fluid supply pipe 26 and the peripheral surface of the hole b. Other configurations are the same as those of the previous embodiment.

To explain the operation of this example, since the compression spring 30 and the cylindrical member 29 are not in contact with the cutting fluid supply pipe 26 but in contact with the spindle shaft 11, while the spindle shaft 11 is rotating, the compression spring 30 and the cylindrical member 29 are in contact with this. Accordingly, the cylindrical member 29 is simply pressed against the rear end surface 20c of the blade holding cylinder member 20 by the elasticity of the compression spring 30, and does not rotate relative to the rear end surface 20c. Therefore, the front end face of the tubular member 29 and the rear end face 20c of the cutting tool holding tubular member 20 are securely brought into close contact with each other. It is more reliably prevented than in the example. Further, the phenomenon that the mist cutting fluid passing through the inside of the tubular member 29 tries to flow backward from between the tubular member 29 and the cutting fluid supply 26 is prevented by the sealing means 202. The roller bearing 201 contributes to smooth relative rotation between the cylindrical member 29 and the cutting fluid supply pipe 26.

FIG. 7 is a side sectional view showing a spindle shaft device of a machine tool showing a second modification of the above embodiment, and FIG. 8 is a sectional view showing a part of the spindle shaft device of FIG. In this example, the spindle shaft 11 does not have the large diameter portion b2, and the cutting fluid supply pipe 26 has the same diameter up to the front end. As shown in FIG. 8, the cylindrical member 29 has a relatively large rear portion 29a guided by the circumferential surface of the large diameter portion b1 in the front-rear directions f1 and f2, and a relatively small diameter front portion 29b. It consists of At this time, the inner hole of the front part b2 is substantially matched with the outer diameter of the cutting fluid supply pipe 26, and is fitted to the cutting fluid supply pipe 26 so as to be densely displaceable in the front and rear directions f1 and f2. Eggplant The rear portion b1 has a relatively large stepped inner hole, and a seal member 301 is fitted into the front inner hole, and the front end surface d3 of the rear inner hole and the rear end surface d4 of the large-diameter portion b1 are connected to each other. A compression spring 30 is mounted on the outside of the cutting fluid supply pipe 26 therebetween. When the rear portion 29a of the tubular member 29 moves forward beyond a certain amount, the retaining ring 32 regulates this movement. Other configurations are the same as those in FIGS. 1 and 2.

To explain the operation of this example, the compression spring 30 and the cylindrical member 29 are not in contact with the cutting fluid supply pipe 20 but in contact with the spindle shaft 11. The cylinder member 29 rotates almost congruently, and the cylinder member 29 is merely pressed by the rear end surface 20c of the blade holding cylinder member 20 by the elastic force of the compression spring 30, and hardly rotates relative to the rear end surface 20c. Therefore, the front end face of the tubular member 29 and the rear end face 20c of the cutting tool holding tubular member 20 are securely in close contact with each other, and the phenomenon in which the mist cutting fluid passing through the inside of the tubular member 29 leaks from the close contact portion is effectively prevented. It will be. The sealing member 301 is in close contact with the peripheral surface of the cutting fluid supply pipe 20 during the rotation of the spindle shaft 11 and slidably rotates with low resistance. This reliably prevents the liquid from flowing backward from between the cutting fluid supply pipe 26. Accordingly, a large amount of the mist cutting fluid passing through the inside of the tubular member 29 does not leak into the inside of the hollow portion T outside the tubular member 29. If a passage groove m2 is formed in the front end face of the tubular member 29, the same applies as described above even if the tubular member 29 and the rear end face 20c of the blade holding cylinder member 20 may rotate relative to each other. In addition, the relative rotation is smoothly performed by being lubricated by the mist cutting fluid.

FIG. 9 is a sectional side view showing a spindle shaft device of a machine tool showing a third modification of the above embodiment, and FIG. 10 is a sectional view showing a part of the spindle shaft device of FIG. In this example, the seal member 301 of the second modified example is omitted, and the inner hole of the front portion 29b of the tubular member 29 is extended rearward as shown in FIG. m1. In this example, the mist cutting fluid passing through the inside of the tubular member 29 tries to flow backward through the gap between the inner peripheral surface of the tubular member 29 and the outer peripheral surface of the cutting fluid supply pipe 26. The groove m1 is effectively limited because it provides a sealing effect by the expansion operation of the gas component of the atomized cutting fluid. Other points are the same as the second modification.

FIG. 11 is a side sectional view showing a spindle shaft device of a machine tool showing a fourth modification of the above embodiment, FIG. 12 shows a part of the spindle shaft device of FIG. 11, and FIG. B is a view seen from the rear. In this example, the cutting fluid supply pipe 26 has a rear end portion which is inserted into the coupling member 27a so as to be freely slidable in the front and rear directions f1 and f2, and has a notch k formed in the rearmost peripheral surface. The notch k is engaged with the tip of an engagement piece 401 fixed to the coupling member 27a by a bolt. This engagement restricts the displacement of the cutting fluid supply pipe 26 in the front-rear direction within a certain range and simultaneously supplies the cutting fluid. It also regulates the rotational displacement of the tube 26. A retaining ring 402 is fitted to the cutting fluid supply pipe 26 in front of the coupling member 27a, and a compression spring 403 is externally fitted to the cutting fluid supply pipe 26 between the retaining ring 402 and the front surface of the coupling member 27a. It is attached to. Further, an inner hole 404 is formed on the rear surface side of the coupling member 27a, and a sealing member for closing the outer peripheral surface of the cutting fluid supply pipe 26 and the inner peripheral surface of the inner hole 404 in the inner hole 404 in a liquid-tight manner. 405 is attached. As in the case shown in FIG. 5, a sealing means 402 for closing the gap between the outer peripheral surface of the cutting fluid supply pipe 26 and the peripheral surface of the passage b is provided.

On the other hand, as shown in FIG. 12, the outer peripheral surface of the cylindrical member 29 having a relatively large diameter is guided to the peripheral surface of the large-diameter portion b2 so as to be freely displaceable in the front-rear direction. A ball bearing 406 is mounted between the peripheral surface and the outer peripheral surface of the relatively short small diameter portion 26a as a bearing member for facilitating relative rotation between them. At this time, the cylindrical member 29 is fixed by caulking to the outer periphery of the ball bearing 406, and the ball bearing 406 is restricted from coming forward by a retaining ring 407 fitted to the front end of the cutting fluid supply pipe 26. ing. Other configurations are the same as those shown in FIGS.

The operation of this example will be described. The cylindrical member 29 is rotatably supported by the cutting fluid supply pipe 26 via the ball bearing 406 and is in direct contact with the spindle shaft 11. During the rotation of the spindle shaft 11, it rotates almost cognately with the spindle shaft 11, and the elasticity of the compression spring 403 is applied through the cutting fluid supply pipe 26. The rotation of the rear end face 20c is almost impossible. Therefore, the front end face of the tubular member 29 and the rear end face 20c of the cutting tool holding tubular member 20 are securely brought into close contact with each other, and the phenomenon in which the mist cutting fluid passing through the inside of the tubular member 29 leaks from this close contact portion is effectively prevented. You. Further, the seal member 202 prevents the liquid cutting fluid flowing through the ball bearing 406 and flowing into the rear passage b from flowing into the lubricating oil space J as described above. The other seal member 405 prevents the mist cutting fluid in the closed chamber 8 from flowing into the lubricating oil space J.

[0049]

[Effect of the invention]

 According to the present invention configured as described above, the following effects can be obtained. In other words, according to the first aspect, the conventional phenomenon that the mist-like cutting fluid that has reached the hollow portion T flows out into the air or into the lubricating oil space through the gap between the parts is prevented. Thus, waste of the cutting fluid and deterioration of the lubricating oil in the lubricating oil space J can be prevented. Further, the mist-like cutting fluid passing through the inner hole of the cylindrical member 29 suppresses the liquefaction by reducing the influence of the rapid expansion of the passage and the centrifugal force. The responsiveness is improved and the mist cutting fluid is stably jetted from the tip of the cutting tool 25.

According to the third aspect, with a relatively simple structure, the front end of the cutting fluid supply pipe 26 and the opening of the starting end of the passage hole c1 are relatively moved in a state where leakage of the mist cutting fluid is suppressed. It can be connected to rotate freely.

According to the fourth aspect, the front end of the cutting fluid supply pipe 26 and the opening of the starting end of the passage hole c1 are connected via the tubular member 29 to the resistance against the relative rotation of the cutting fluid supply pipe 26 and the passage hole c1. Can be communicated in a state where there is little.

According to the fifth aspect, by guiding the cylindrical member 29 to the peripheral surface of the hollow portion T, the cylindrical member 29 can be relatively quietly rotated with respect to the cutting fluid supply pipe 26 with small resistance. The sealing member 301 can reliably prevent the mist cutting fluid from flowing out of the gap between the tubular member 29 and the cutting fluid supply pipe 26.

According to the sixth aspect, even if the cylindrical member 29 and the cutting fluid supply pipe 26 are not relatively displaced in the front-rear direction and the elastic member is not brought into contact with the rotating part, the front end of the cutting fluid supply pipe 26 can be connected to The start opening of the passage hole c1 can be communicated via the tubular member 29 so as to be relatively rotatable in a state where leakage of the mist cutting fluid from inside the tubular member 29 is suppressed.

According to the seventh aspect, a portion between the front end of the cutting fluid supply pipe 26 and the opening of the starting end of the passage hole c1 in the inner hole of the cylindrical member 29 has a relatively small diameter, Liquefaction of the atomized cutting fluid in the inner hole portion can be effectively suppressed.

According to the eighth aspect, even when a gap is provided between the tubular member 29 and the cutting fluid supply pipe 26, the mist cutting fluid in the tubular member 29 flows out from the gap to the outside. Therefore, the relative rotation between the cylindrical member 29 and the cutting fluid supply pipe 26 can be performed with little resistance.

According to the ninth aspect, when the front end face of the tubular member 29 is pressed against the front end face of the hollow portion T (the rear end face 20c of the cutting tool holding tubular member 20) and these are relatively rotated, the passage is formed. The atomized cutting fluid passing through the groove m2 lubricates the relative rotation to make it smooth.

[Brief description of the drawings]

FIG. 1 is a side sectional view showing a spindle shaft device of a machine tool according to an embodiment of the present invention.

FIG. 2 is a diagram showing an xx section of FIG. 1;

FIG. 3 is an enlarged sectional view of the spindle shaft device.

FIG. 4 is a view showing a main part of the spindle shaft device of FIG. 3;

FIG. 5 is a side view sectional view showing a spindle shaft device of a machine tool showing a first modification of the embodiment.

FIG. 6 is a sectional view showing a part of the spindle shaft device of FIG. 5;

FIG. 7 is a side sectional view showing a spindle shaft device of a machine tool showing a second modification of the embodiment.

FIG. 8 is a sectional view showing a part of the spindle shaft device of FIG. 7;

FIG. 9 is a side sectional view showing a spindle shaft device of a machine tool showing a third modification of the embodiment.

FIG. 10 is a sectional view showing a part of the spindle shaft device of FIG. 9;

FIG. 11 is a side sectional view showing a spindle shaft device of a machine tool showing a fourth modification of the embodiment.

12 shows a part of the spindle shaft device of FIG.
Is a cross-sectional view and B is a view seen from the rear.

[Explanation of symbols]

DESCRIPTION OF SYMBOLS 11 Main shaft (machine rotating shaft), spindle shaft (machine rotating shaft) 20c Rear end face of cutting tool holding tubular member 20 (front end face of hollow portion T) 25 Cutting tool 26 Cutting fluid supply pipe 29 Tube member 30 Elastic member 201 Bearing member 301 Seal Member 403 Elastic member 406 Bearing member T Hollow portion c1 Passage hole m1 Annular groove (labyrinth structure) m2 Passage groove

Claims (9)

[Utility model registration claims] 1. A cutting fluid supply pipe is provided in a non-rotating state at a center of rotation of a machining rotary shaft such as a main shaft and a spindle shaft, and a front end of the cutting fluid supply pipe is opened to a hollow portion at a front part of the machining rotary shaft. In a machine tool provided with a relatively small-diameter passage hole extending from the front end surface of the hollow portion to the base end of the cutting tool fixed to the tip end of the machining rotary shaft, the front end of the cutting fluid supply pipe is provided. And a starting end opening of the passage hole is relatively rotatably communicated with each other via a cylindrical member disposed in the hollow portion. 2. A cutting fluid supply pipe is provided in a non-rotating state at a center of rotation in each of the machining spindles, and a front end of the cutting fluid supply pipe is attached to the machining spindle. Open to the front hollow part, from the front end face of this hollow part,
In a machine tool provided with a relatively small-diameter passage hole that extends to the base end of the cutting tool fixed to the tip of the machine rotating shaft,
The front end of the cutting fluid supply pipe and the start end opening of the passage hole,
A machine rotary shaft device for a machine tool, characterized in that the machine rotary shaft device is in communication with a relatively rotatable via a cylindrical member disposed in the hollow portion. 3. A cylindrical member is fitted to the front end of the cutting fluid supply pipe so as to be slidable and displaceable within a certain range in the direction of the center of rotation of the machine rotating shaft, and the cylindrical member is directed toward the front end face of the hollow portion. 2. The machine rotary shaft device for a machine tool according to claim 1, further comprising an elastic member for urging. 4. A bearing member is provided between an outer peripheral surface of a front end portion of a cutting fluid supply pipe and an inner peripheral surface of a cylindrical member so as to be rotatable relative to each other and to be displaceable in the direction of the center of rotation of a machine rotating shaft. 4. The machine rotary shaft device for a machine tool according to claim 3, wherein the elastic member is disposed in a non-contact state with the cutting fluid supply pipe. 5. A cylindrical member having a relatively large diameter is extrapolated to the front end surface of the cutting fluid supply pipe, and the outer peripheral surface of the cylindrical member is fixed to the peripheral surface of the hollow part in the direction of the center of rotation of the machine rotary shaft. The sliding member is guided so as to be freely slidable within the range, and the gap between the outer peripheral surface of the cutting fluid supply pipe and the inner peripheral surface of the cylindrical member is closed in a liquid-tight manner with a sealing member, and the cylindrical member is closed on the front end surface side of the hollow portion. 2. The machine rotary shaft device for a machine tool according to claim 1, wherein an elastic member for urging toward the cutting tool is disposed in a non-contact state with the cutting fluid supply pipe. 6. The cutting fluid supply pipe is capable of being displaced back and forth within a certain range in the direction of the center of rotation of the machining rotary shaft and is urged forward by an elastic member. The cylindrical member is connected to the front end of the cutting fluid supply pipe. 2. The machine rotary shaft device for a machine tool according to claim 1, wherein only the relative rotation is mounted on the portion via a bearing member. 7. A part of the inner hole of the cylindrical member, which is located between the front end of the cutting fluid supply pipe and the front end face of the hollow part, substantially matches the outer diameter of the front end of the cutting fluid supply pipe. 7. The machine rotary shaft device for a machine tool according to claim 1, 2, 3, 4, 5, or 6. 8. An inner hole of the cylindrical member is fitted around the front end portion of the cutting fluid supply pipe in a substantially dense manner, and a center of rotation of the work rotary shaft at this place is fitted to the densely fitted place. 8. The machine rotary shaft device for a machine tool according to claim 1, wherein a labyrinth structure for controlling gas flow in the direction is formed. 9. The machine rotary shaft device for a machine tool according to claim 1, wherein a relatively narrow passage groove is formed over the entire length of the front end face of the cylindrical member in the thickness direction.