JP4820166B2 - Machine tool spindle equipment - Google Patents

Description

  The present invention relates to a spindle device of a machine tool.

  In general, when a workpiece is machined by a tool mounted on a spindle device of a machine tool, for example, a cutting fluid is supplied from a cutting fluid supply nozzle to the machining portion in order to cool and lubricate the workpiece machining portion by the tool. It comes to supply. As this cutting fluid supply device, there has been a device that supplies a large amount of the cutting fluid pumped from the cutting fluid tank to the machining portion of the workpiece from the cutting fluid supply nozzle through the cutting fluid supply pipe.

  However, this processing method consumes a large amount of power to supply a large amount of cutting fluid, and requires a great amount of labor for the treatment of the waste fluid. This increases the cost and adversely affects the pollution of the global environment. It was.

  In order to solve the above-described problem, there is also a type using a mist supply device in which the cutting fluid is supplied in a mist form to a workpiece processing portion. In this mist supply device, a mist generator is provided in a container for storing cutting fluid, and the mist generator is operated when a workpiece is processed. Then, the mist is supplied from the tip ejection port of the tool to the processing part of the workpiece through the mist supply pipe provided in the spindle of the spindle device and the mist supply path provided in the center of the tool through the mist supply pipe from the storage container. It is supposed to be. Further, as a spindle device of a machine tool provided with a mist generator, for example, there is one disclosed in Patent Document 1.

This spindle device is provided with two systems of supply passages for separately supplying gas and liquid into the spindle, and the supplied gas and liquid are mixed in a mist generator provided in the tip of the spindle or in the tool holder. The mist is generated and supplied to the processing part. In addition, the main shaft device is closed when the liquid pressure is below a certain level in order to prevent liquid dripping from the mist generating device at a position corresponding to the liquid line side immediately before the mist generating device inside the main shaft. A stop valve is provided that is held in a state.
JP-A-9-66437 (see paragraph number 0036 and FIG. 12 of the specification)

  The spindle device provided with the mist generator of the conventional machine tool takes a long time from when the mist generator is operated until the pressure of the mist reaches the set pressure. For this reason, the start of mist supply is delayed, and workpieces are machined for a relatively long time in the absence of cutting fluid, resulting in a problem of tool damage and workpiece machining accuracy.

  On the other hand, the spindle device of the machine tool described in Patent Document 1 is provided with two supply paths, and a stop valve for stopping the liquid line side is constituted by a ball and a spring, so that the fluid resistance is too large, It is not suitable as a line for supplying mist. Further, even when the example (see FIG. 11) in which the ball and the spring are omitted is applied, the supply path has a very small diameter, so that the fluid resistance is large and the mist cannot be prevented from flowing out even when the mist is not supplied. there were. Furthermore, in the configuration described in Patent Document 1, it is necessary to configure the two supply paths to the vicinity of the tip of the main spindle, the number of parts increases, the manufacturing and assembly work is troublesome, and the cost can be reduced. There was a problem that I could not.

  The present invention solves the above-mentioned problems in the prior art, and synchronizes with the start of rotation of the main shaft or when the mist pressure in the supply passage becomes a predetermined pressure or more, the mist is processed into the workpiece processing part. An object of the present invention is to provide a spindle device of a machine tool that can be supplied with a low mist flow path resistance and can appropriately perform a workpiece machining operation.

  In addition to the above object, another object of the present invention is to provide a spindle device for a machine tool that can reduce the number of parts of an on-off valve, facilitate manufacturing and assembly operations, and reduce costs. .

In order to solve the above-mentioned problems, the invention according to claim 1 is directed to rotatably support a main shaft having a fitting hole for mounting a tool holder through a bearing in a housing, and A mist supply path that opens to the fitting hole is provided, and an on-off valve is provided on the downstream side of the supply path, and the on-off valve is provided with a centrifugal force when the main shaft rotates or the pressure of the mist in the supply path. In the spindle device of a machine tool configured to be openable when the pressure exceeds a predetermined pressure , the on-off valve is integrally formed to be openable and closable at a cylindrical main body formed of an elastic material and a distal end portion of the main body. And is always held in a closed state by an elastic restoring force, and resists the elastic restoring force from the closed state when the centrifugal force during rotation of the main shaft or the pressure of the mist in the supply passage exceeds a predetermined pressure. this being constituted by a valve body Te deformed open state The the gist.

The gist of a second aspect of the present invention is that, in the first aspect , the valve body is provided with a weight that promotes a valve opening operation of the valve body by a centrifugal force when the main shaft rotates.
According to a third aspect of the present invention, in the first or second aspect , a flange portion for mounting the on-off valve inside the main shaft is integrally formed on the outer periphery of the rear end portion of the main body of the on-off valve. This is the gist.

  According to the first aspect of the present invention, an on-off valve is disposed on the downstream side of a mist supply path of one system formed inside the main shaft, and the on-off valve is provided with a centrifugal force during rotation of the main shaft or within the supply path. The mist was released when the pressure of the mist exceeded a predetermined pressure. For this reason, the passage sectional area of the on-off valve can be set large, and the mist flow resistance of the mist supply passage can be reduced, so that the mist can be efficiently supplied to the processing section. In addition, the mist can be supplied to the workpiece machining section in synchronization with the start of rotation of the main shaft or when the mist pressure in the supply passage becomes equal to or higher than a predetermined pressure, and the workpiece machining operation is performed appropriately. be able to.

In addition , the on-off valve is formed integrally with a cylindrical main body made of an elastic material, and at the tip of the main body, and is always held in a closed state by an elastic restoring force. Or when the pressure of the mist in the said supply path becomes more than predetermined pressure, it is comprised by the valve body which deform | transforms from a valve closing state to a valve opening state. For this reason, the number of parts of the on-off valve can be reduced, manufacturing and assembly work can be easily performed, and the cost can be reduced.

According to a second aspect of the present invention, in the first aspect , the valve body is provided with a weight for promoting the valve opening operation of the valve body by a centrifugal force at the start of rotation of the main shaft. For this reason, the valve body can be opened quickly, and the opening amount of the valve body can be increased.

According to a third aspect of the present invention, a flange portion for mounting the on-off valve on the main shaft is integrally formed on the outer periphery of the rear end portion of the main body of the on-off valve. For this reason, the number of parts of the on-off valve can be reduced, manufacturing and assembly work can be easily performed, and the cost can be reduced.

Hereinafter, an embodiment of a spindle device for a machine tool embodying the present invention will be described with reference to FIGS.
First, the configuration of the spindle device will be described with reference to FIG.

  A hollow cylindrical main shaft 13 is rotatably supported by a built-in motor 14 through a pair of front and rear bearings 12 in a housing 11 having a horizontal cylindrical shape. A tapered fitting hole 13b is formed at the tip (left side in FIG. 5) of the shaft hole 13a of the main shaft 13, and a so-called BT type tool holder 16 holding the tool 15 is removed from the fitting hole 13b. It is installed as possible. The tool 15 is screwed to the chuck member 17 interposed between the outer peripheral surface of the tool holder 16 and the inner peripheral surface of the tool holder 16, and the tip outer peripheral portion of the tool holder 16, and presses the chuck member 17 in the thrust direction. It is attached to the tool holder 16 by a tightening ring 18 for the purpose.

  A clamp mechanism K for clamping the tool holder 16 is mounted in the shaft hole 13 a of the main shaft 13. The outline of the clamping mechanism K will be described. A pull rod 21 is inserted into the shaft hole 13 a of the main shaft 13, and a steel ball 22 is attached to a pull stud 16 a integrally formed at the base end portion of the tool holder 16 at the distal end portion. It is comprised so that latching is possible. A flange fitting 23 is fitted and fixed to the base end portion of the pull rod 21. Between the flange fitting 23 and a locking step portion 13 c formed on the inner peripheral surface of the shaft hole 13 a of the main shaft 13, A disc spring 24 is interposed.

  Accordingly, when the pull rod 21 is moved rightward in FIG. 5 by the elastic force of the disc spring 24, the pull stud 16a is drawn by the steel ball 22 so that the tool holder 16 is held at a predetermined position of the main shaft 13. It has become. On the contrary, the flange fitting 23 is pushed forward against the elastic force of the disc spring 24 by a drive mechanism (not shown), and the pull stud 16a of the tool holder 16 by the tip of the pull rod 21 and the steel ball 22 is used. When the holding is released, the tool 15 and the tool holder 16 are exchanged by an automatic tool changer (not shown).

  A system of mist supply passages 21 a is formed at the center of the pull rod 21. Mist supply passages 15 a and 16 b are formed so as to communicate with the central portion of the tool 15 and the tool holder 16, and the mist supply passage 15 a is opened at the front end surface of the tool 15. Mist is supplied to the inlet of the mist supply path 16 b of the tool holder 16 by a mist supply path 21 a formed in the pull rod 21.

  A rotary joint 27 is provided at the inlet of the mist supply passage 21 a opened at the base end of the pull rod 21, and a mist generator 29 provided outside the main shaft 13 is connected to the rotary joint 27 via a pipe 28. Has been. The pipe 28 is provided with an electromagnetic on-off valve 30. When the electromagnetic on-off valve 30 is opened, the mist is supplied from the mist generator 29 through the pipe 28 and the rotary joint 27 to the mist supply path 21a in the main shaft 13, and the mist supply path 16b of the tool holder 16 and the mist supply of the tool 15 are supplied. Mist is supplied from the opening of the end of the path 15a to the processed portion of the workpiece W.

Next, the structure of the clamping mechanism K of the tool holder 16 and the main part of the present invention will be described.
As shown in FIGS. 1 and 5, an opening / closing valve 31 is attached to the tip of the pull rod 21. The pull rod 21 is divided and formed by a main body 32 and an operating cylinder 33 having a male screw portion 33a screwed into a screw hole 32a formed at the tip thereof. The operation cylinder 33 is formed with an engagement hole 33b for engaging the steel ball 22 of the clamp mechanism K. As shown in FIG. 1, a step 13 d is formed at the tip of the shaft hole 13 a of the main shaft 13 so as to correspond to the steel ball 22. As shown in FIG. 3, in a state where the main body 32 and the working cylinder 33 are moved forward against the elastic force of the disc spring 24 (see FIG. 5), the steel ball 22 falls into the step portion 13d, and the tool holder 16 (see FIG. 1) pull studs 16 a are configured to be able to enter the inside of the working cylinder 33. 3, when the main body 32 and the operating cylinder 33 are moved backward by the disc spring 24 in a state where the pull stud 16a of the tool holder 16 is inserted into the operating cylinder 33, as shown in FIG. The steel ball 22 pulls the pull stud 16a so that the tool holder 16 is clamped at a predetermined position.

  As shown in FIG. 1, the on-off valve 31 is formed integrally with a cylindrical main body 31a formed of an elastic material such as acrylonitrile rubber, ethylene propylene rubber, silicone rubber, or butyl rubber, and a distal end portion of the main body 31a. When the main shaft 13 rotates, the centrifugal force or the pressure of the mist supplied by the mist generator 29 exceeds a predetermined pressure. And a valve body 31b that is expanded in the direction of repetition. In addition, a flange portion 31c is integrally formed on the outer peripheral surface of the rear end portion of the main body 31a so as to be interposed at a joint portion between the main body 32 and the working cylinder 33. The flange portion 31c is sandwiched between the joint portions of the main body 32 and the operating cylinder 33, the main body 31a is inserted into the operating cylinder 33, and the tip of the valve body 31b is directed to the tool holder 16 side.

  As shown in FIG. 4, weights 34 are bonded to both outer surfaces of the valve body 31b. When the main shaft 13 is rotated and a centrifugal force acts on the valve body 31b of the on-off valve 31, both weights 34 are moved away from each other by the centrifugal force to resist the valve body 31b against its elastic restoring force. The deformation from the closed state to the open state is promoted.

Next, the operation of the spindle device of the machine tool configured as described above will be described.
As shown in FIG. 5, when the main shaft 13 of the main shaft device is stopped and the on-off valve 31 is closed, the mist generating device 29 is operated and the electromagnetic on-off valve 30 is switched to the valve open position. Is supplied into the mist supply passage 21 a upstream of the on-off valve 31 through the pipe 28 and the rotary joint 27. In this state, when the spindle 13 of the spindle device is rotated by the built-in motor 14 to start machining the workpiece, the on-off valve 31 is also rotated together with the pull rod 21. When the on-off valve 31 is rotated, centrifugal force is applied to the valve body 31b, and the pressure of the mist is equal to or higher than a predetermined pressure. Therefore, the valve body 31b is deformed from the closed state to the open state, and the mist is supplied. The mist in the path 21a is sprayed to the outside from the mist supply path 16b of the tool holder 16 and the mist supply path 15a of the tool 15, and the mist is supplied to the processing part of the workpiece by the tool 15 to cool and lubricate the processing part. .

  After the machining operation of the workpiece W is completed, when the built-in motor 14 is stopped and the rotation of the main shaft 13 is stopped, and when the electromagnetic on-off valve 30 is switched to the valve closing position, centrifugal force is reduced and mist is generated. Since the mist supply from the device 29 is also stopped and the pressure of the mist becomes equal to or lower than the predetermined pressure, the valve body 31b of the on-off valve 31 is switched from the open state to the closed state by the elastic restoring force, and the mist supply path 21a The supply of mist to the outside is stopped. In this state, the mist is filled in the mist supply path 21a. Therefore, when the next workpiece is started to be processed, mist is immediately supplied to the workpiece processing portion as soon as the processing is started as described above.

  When the rotation of the main shaft 13 is stopped, the valve body 31b of the on-off valve 31 is immediately closed, so that mist remaining in the mist supply path 21a does not leak to the outside from the mist supply path 21a. Further, even when the tool holder 16 is removed from the fitting hole 13b, the valve body 31b of the on-off valve 31 is in the closed state, so that the mist is not liquefied and leaks to the outside.

According to the spindle device of the machine tool of the above embodiment, the following features can be obtained.
(1) In the above embodiment, since the opening / closing valve 31 is housed at the tip of the mist supply passage 21a of one system formed inside the pull rod 21, the passage sectional area of the opening / closing valve 31 can be set large. The mist flow path resistance of the mist supply path 21a can be reduced and the mist can be efficiently supplied to the processing portion. Further, the valve body 31b of the on-off valve 31 opens from the closed state against the elastic restoring force when the centrifugal force due to the rotation of the main shaft 13 or the pressure of the mist supplied by the mist generator 29 exceeds a predetermined pressure. It was changed to a valve state. For this reason, the on-off valve 31 can be opened almost simultaneously with the rotation of the main shaft 13 or when the pressure of the mist supplied by the mist generating device 29 becomes equal to or higher than a predetermined pressure. The mist can be supplied in a timely manner, the lack of lubrication after the start of machining can be resolved, the tool 15 can be damaged and the machining accuracy of the workpiece can be prevented, and the workpiece can be machined properly.

  (2) In the above embodiment, since the on-off valve 31 is integrally formed by the main body 31a, the valve body 31b, and the flange portion 31c, the number of parts of the on-off valve 31 is reduced, and the manufacturing and assembling operations are easily performed. Cost can be reduced.

  (3) In the above embodiment, the valve body 31b of the on-off valve 31 can be maintained in a closed state in which the valve body 31b is flattened by the elastic restoring force. It can be surely prevented.

  (4) In the above embodiment, since the weight 34 is attached to the valve body 31b of the on-off valve 31, the opening operation of the valve body 31b can be performed quickly using the centrifugal force generated by the rotation of the main shaft 13.

In addition, you may change this embodiment as follows.
As shown in FIG. 6, a weight 34 may be embedded in the valve body 31 b of the on-off valve 31. In this embodiment, when the valve body 31b is in the open state, the outer peripheral surface of the valve body 31b is deformed to a position where it comes into contact with the inner peripheral surface of the operating cylinder 33, so that the passage sectional area of the valve body 31b can be increased. it can.

Although not shown, the weight 34 of the on-off valve 31 may be omitted.
Although not shown, the shape of the valve body 31b of the on-off valve 31 is not limited to the flat shape as in the embodiment, and may be other shapes that can be opened and closed, and other configurations.

  Although not shown in the drawings, a so-called KM holder or HSK holder may be used as the tool holder 16, and a spindle device using a clamp mechanism corresponding to them may be used.

The valve body 31b of the on-off valve 31 may be configured to be opened when the pressure of the mist supplied by the mist generating device 29 exceeds a predetermined pressure regardless of the centrifugal force.
-You may comprise so that the valve body 31b of the on-off valve 31 may be opened only by the centrifugal force which acts on the on-off valve 31 irrespective of a pressure.

BRIEF DESCRIPTION OF THE DRAWINGS FIG. 1 is a longitudinal sectional view of a closing state of an on-off valve showing a structure of a tip portion of a spindle of a machine tool spindle device embodying the present invention. The longitudinal cross-sectional view which shows the valve opening state of the on-off valve of FIG. The fragmentary longitudinal cross-section of the main axis | shaft of the state which removed the tool holder. The perspective view of an on-off valve. The longitudinal cross-sectional view of a main shaft apparatus. The front view which shows another embodiment of this invention.

Explanation of symbols

  K ... Clamp mechanism, 13 ... Main shaft, 13b ... Fitting hole, 16 ... Tool holder, 21 ... Pull rod, 31 ... Open / close valve, 31a ... Main body, 31b ... Valve body, 31c ... Flange part, 34 ... Weight.

Claims (3)

A main shaft having a fitting hole for mounting a tool holder through a bearing inside the housing is rotatably supported, and a supply path for a mist opening to the fitting hole is provided inside the main shaft, and the supply is provided. A main spindle of a machine tool provided with an on-off valve on the downstream side of the passage and configured to be openable when the centrifugal force during rotation of the main shaft or the pressure of the mist in the supply passage exceeds a predetermined pressure. In the device
The on-off valve is formed integrally with a cylindrical main body made of an elastic material and can be opened and closed at the tip of the main body, and is always held in a closed state by an elastic restoring force. And a valve body that deforms from a closed state to an open state against an elastic restoring force when the force or the pressure of the mist in the supply passage exceeds a predetermined pressure. The main spindle device of the machine. 2. The spindle device of a machine tool according to claim 1, wherein the valve body is provided with a weight for promoting the valve opening operation of the valve body by a centrifugal force when the spindle is rotated. 3. The main spindle of a machine tool according to claim 1, wherein a flange portion for mounting the on-off valve is integrally formed inside the main shaft on an outer periphery of a rear end portion of the main body of the on-off valve. apparatus.

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