JP2007307679A - Spindle device - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To provide a spindle device having a simple constitution and removing chips attached to a tool holder and a tapered hole using coolant fed to the tool holder. <P>SOLUTION: A cylinder chamber 23 is formed between the front end face of a large diameter part 4c provided in a draw bar 4 and the front end face of a large-diameter hole 11b provided in a through-hole 11, a cleaning passage 25 communicating the cylinder chamber 23 with a tapered hole 10 is provided and, when replacing the tool holder 5, part of coolant fed in the tool holder 5 mounted on a spindle 6 is fed into a clearance between the tool holder 5 and the tapered hole 10 from the cylinder chamber 23. <P>COPYRIGHT: (C)2008,JPO&INPIT

Description

  The present invention relates to a spindle device that supplies coolant to a tool holder mounted in a tapered hole of a spindle.

Conventionally, a taper hole in which a tool holder is detachably mounted is formed at the tip of the spindle, and the tool holder mounted in the taper hole is clamped in a through hole formed so as to be continuous with the taper hole. A draw bar having a portion is inserted so as to be movable in the axial direction, and a coolant passage capable of communicating with the coolant flow path of the tool holder is provided in the holding portion, and a coolant supply hole through which the coolant can be supplied is provided in the draw bar. A main spindle device is known.
When a workpiece is machined using the spindle device, coolant is sprayed on a cutting tool or workpiece to cool the tool tip and the workpiece or to remove chips from the machining location. In addition, each time the workpiece machining location changes, a tool holder holding a cutting tool corresponding to the workpiece machining location is attached to the tapered hole. However, during replacement of the tool holder, coolant scattered during the machining of the workpiece adheres to the tool holder and the taper hole before being attached to the spindle. If the coolant contains chips or the chips adhere to the coolant, the removal of the chips will affect the tool holder mounting accuracy (coaxial or concentricity of the tool) and increase workpiece machining accuracy. Therefore, as described in Patent Document 1, the clearance formed between the tool holder and the taper hole is removed from the cleaning passage provided on the main shaft by the coolant accumulated in the passage in the forward / backward rod provided in the forward / backward rod. To remove chips adhering to the taper hole by jetting a mixture of pressurized air and coolant afterwards, or extending through a spindle (main shaft) as described in Patent Document 2 It is known to remove chips adhering to the tool housing part by spraying coolant (coolant) inside the tool holder or tool housing part (taper hole) through the internal passage. .
JP 2001-310229 A JP-A-11-90762

The advancing / retreating rod internal passage described in Patent Document 1 is formed by connecting the first communication passage and the second communication passage via a switching valve mechanism. When coolant is supplied to the tool holder, the switching valve mechanism When the first communication path and the second communication path are communicated and coolant is supplied to the gap, the first communication path and the cleaning path are communicated by a switching valve mechanism. However, since the switching valve mechanism is actuated by the movement of the advance / retreat rod that moves in the main shaft, the operation of the switching valve mechanism cannot be confirmed at the time of assembly, so that there is a possibility that the coolant cannot be reliably ejected into the gap. Further, as in Patent Document 2, when the coolant is sprayed from the internal passage to the gap formed between the tool holder and the tool storage portion when the tool holder is replaced, sufficient cooling is performed from the internal passage to the tip position of the tool storage portion. There was a possibility that the chips could not be removed reliably without spraying the agent and trying to adhere to the taper hole from the gap.
SUMMARY OF THE INVENTION Accordingly, an object of the present invention is to solve the above-mentioned problems, and has a simple configuration in which a spindle that removes chips adhering to a tool holder or a tapered hole using a coolant supplied to the tool holder. An object is to provide an apparatus.

  The spindle device of the present invention has a tapered hole in which a tool holder is detachably mounted at the tip of the spindle, and a tool mounted in the tapered hole in a through hole drilled to be continuous with the tapered hole. A coolant supply hole in which a draw bar having a holding portion for clamping the holder is inserted so as to be movable in the axial direction, a coolant passage is provided in the holding portion so as to communicate with the coolant flow path of the tool holder, and coolant can be supplied to the passage. A tool holder mounted on the spindle, wherein a cylinder chamber is formed between the front end face of the large diameter portion provided in the draw bar and the front end face of the large diameter hole provided in the through hole. A cleaning passage is provided so that a part of the coolant supplied to the cylinder is supplied from the cylinder chamber to a gap between the tool holder and the tapered hole.

  In the present invention, a cylinder chamber is formed between the front end surface of the large diameter portion provided in the draw bar and the front end surface of the large diameter hole provided in the through hole, and the cylinder chamber and the tapered hole are communicated with the main shaft. When the coolant is supplied to the tool holder provided in the tapered hole with the passage, a part of the coolant is supplied to the cleaning passage through the cylinder chamber, and the draw bar is pushed forward in the axial direction when the tool holder is replaced. In addition to the coolant sprayed from the draw bar side to the tool holder and the taper hole, the coolant is sprayed from the cleaning passage, so that the tip side of the taper hole is Thus, the coolant is surely sprayed, and the chips that adhere to the tapered hole from the gap are reliably removed.

  A spindle apparatus 1 shown in FIG. 1 is configured by connecting a coolant supply means 3 to the rear of a spindle driving motor 2 and connecting a spindle 6 to which a tool holder 5 is clamped by a draw bar 4 to the front. . In order to replace the tool holder 5, the spindle device 1 includes a holding state release mechanism 7 that can release the clamped state of the tool holder 5 by pushing the draw bar 4 forward in the axial direction. First, the main shaft 6 will be described. The main shaft 6 is rotatably supported by a plurality of bearings 9 provided in the main shaft head 8. A taper hole 10 is formed at the tip of the main shaft 6. A cutting tool T (for example, a tool changer (not shown) corresponding to a workpiece machining position from a tool magazine (not shown) is formed in the taper hole 10. A tool holder 5 holding a drill) is mounted. The tool holder 5 is provided with a coolant channel 5a for supplying coolant outwardly through the cutting tool T. A through-hole 11 having a small-diameter hole 11a is formed in the shaft center of the main shaft 6 so as to be continuous with the tapered hole 10, and a large-diameter hole opened to the rear of the main shaft 6 behind the through-hole 11. 11b is continuously provided. The draw bar 4 is inserted into the through hole 11 so as to be movable in the axial direction. The draw bar 4 has a coolant supply hole 12 through which the coolant supplied from the coolant supply means 3 flows.

The draw bar 4 is a stepped shaft member extending in the axial direction, and a screw portion is formed on the distal end side of the small diameter portion 4a. A holding portion 13 that clamps the rear end portion of the tool holder 5 by the axial movement of the draw bar 4 is screwed to the screw portion. The holding portion 13 is provided with a coolant passage 14 including a stepped hole communicating with the coolant supply hole 12 of the draw bar 4. A communication member 16 urged forward by a spring member 15 is fitted into the large-diameter hole 14a of the passage 14 so as to be movable in the axial direction. The communication member 16 is prevented from coming out forward by a stop member 17 fitted in the holding portion 13. Therefore, the communication member 16 is urged forward by the spring member 15 and the front end surface of the communication member 16 is pressure-bonded to the rear end surface of the tool holder 5, so that the coolant does not leak to the outside of the holding portion 13 and enters the coolant channel 5 a. Will be supplied.
A large number of disc springs 18 exemplified as urging means are stacked between the front end surface of the abutting portion 4 b formed continuously with the small diameter portion 4 a and the end surface of the through hole 11. When the draw bar 4 is urged rearward in the axial direction (clamping direction) by the spring force, the holding portion 13 moves rearward in the axial direction while clamping the rear end portion of the tool holder 5 mounted in the tapered hole 10. The tool holder 5 and the draw bar 4 are in a clamped state. Further, when the draw bar 4 is pushed forward in the axial direction (unclamping direction) by the holding state release mechanism 7 through the pin member 19 fitted in the large diameter portion 4c formed continuously with the contact portion 4b. The holder 13 moves forward in the axial direction while releasing the clamped state with the rear end portion of the tool holder 5, whereby the tool holder 5 and the draw bar 4 are in an unclamped state.

Next, a spindle driving motor 2 is installed behind the spindle 6. The main shaft driving motor shaft 2a is a hollow shaft, and a coolant supply means 3 is connected to the rear end portion of the hollow shaft 2a, and the main shaft 6 is connected to the front end portion of the hollow shaft 2a via a connecting member 20. The connecting member 21 is fixed to the front end portion of the hollow shaft 2a. Even if the draw bar 4 is moved forward in the axial direction by the holding state releasing mechanism 7, the distal end side of the connecting member 21 is the coolant supply hole 12 of the draw bar 4. It is made not to come off. Further, by providing the large-diameter portion 4c and the through-hole 11 of the draw bar 4 with the sealing members 22, respectively, a cylinder chamber 23 is formed between the front end surface of the large-diameter portion 4c and the front end surface of the large-diameter hole 11b. A communication path 24 is provided in the contact portion 4b of the draw bar 4 so that a part of the coolant supplied from the coolant supply means 3 to the tool holder 5 is supplied to the cylinder chamber 23.
A plurality of cleaning passages 25 (for example, two) are provided in the main shaft 6 to allow the cylinder chamber 23 and the tapered hole 10 to communicate with each other. When the coolant is supplied to the tool holder 5 mounted in the tapered hole 10, a part of the coolant is supplied to each cleaning passage 25 via the cylinder chamber 23. Since the opening on the tapered hole 10 side of each cleaning passage 25 is closed by the tool holder 5 (the state shown in FIG. 1), a force that moves the draw bar 4 rearward in the axial direction is generated by the action of the cylinder chamber 23. This force is larger than the force that pushes the draw bar 4 generated in the coolant supply hole 12, the communication member 16, and the like in the axial direction forward due to the fluid pressure of the coolant. Therefore, not only the force that pushes the draw bar 4 forward due to the hydraulic pressure of the coolant supplied to the tool holder 5 is canceled but also the clamping force that clamps the tool holder 5 is increased.

  The operation of the spindle device 1 having the above configuration will be described. When the tool holder 5 holding the cutting tool T corresponding to the machining location of the workpiece is mounted in the tapered hole 10 of the main shaft 6 and the draw bar 4 is urged rearward in the axial direction by the spring force of the disc spring 15, the holding portion The tool holder 5 and the draw bar 4 are in a clamped state by moving 13 backward in the axial direction while clamping the rear end portion of the tool holder 5 mounted in the tapered hole 10. Then, the coolant is supplied from the coolant supply means 3 to the tool holder 5 through the coolant supply hole 12 and the coolant passage 14 together with the driving of the spindle driving motor 2, and is held by the tool holder 5 while cooling the processing portion by the coolant. The workpiece is processed by the cutting tool T. When the machining of the workpiece is completed, when the tool holder 5 corresponding to the machining location of the next workpiece needs to be replaced, the spindle driving motor 2 is stopped and the draw bar 4 is pushed forward in the axial direction by the holding state release mechanism 7. And the holding | maintenance part 13 will move to an axial direction front, releasing the clamp state with the tool holder 5 rear end part, and the tool holder 5 and the draw bar 4 will be in an unclamp state. Thereafter, the used tool holder 5 and the tool holder 5 corresponding to the processing position of the next workpiece are replaced by a tool changer (not shown), and the workpiece is processed again. This operation is repeated until the machining of the workpiece is completed.

  When coolant is supplied from the coolant supply means 3 to the tool holder 5 mounted in the taper hole 10, a part of the coolant is supplied to the cleaning passage 25 via the cylinder chamber 23. Since the opening on the tapered hole 10 side of the cleaning passage 25 is closed by the tool holder 5, the cleaning passage 25 and the cylinder chamber 23 are filled with coolant. As shown in FIGS. 1 and 2, when the draw bar 4 is pushed forward in the axial direction when the tool holder 5 is replaced, a gap H is generated between the tool holder 5 and the tapered hole 10. In addition to the coolant sprayed from the coolant passage 14, the coolant is sprayed from the cleaning passage 25. Thereafter, even when the tool holder 5 is separated from the tapered hole 10 as shown in FIG. 3, the coolant is sprayed from the coolant passage 14 and the cleaning passage 25 to the tapered hole 10. Accordingly, the coolant is surely sprayed from the cleaning passage 25 to the tip end side of the tapered hole 10 without providing a complicated mechanism in the holding portion 13 as in the prior art, so that the holder 13 tries to adhere to the tapered hole 10 from the gap H. Chips can be removed reliably.

It is sectional drawing of the main axis | shaft apparatus of this invention, Comprising: The clamp state of a tool holder is shown. It is an enlarged view of the front end side of a main axis | shaft, Comprising: The unclamped state of a tool holder is shown. It is a figure which shows the state from which a tool holder is removed from a main axis | shaft, or is mounted | worn.

Explanation of symbols

DESCRIPTION OF SYMBOLS 1 Main shaft apparatus 4 Draw bar 4c Large diameter part 5 Tool holder 5a Coolant flow path 6 Main axis | shaft 10 Tapered hole 11 Through-hole 11b Large diameter hole 12 Coolant supply hole 13 Holding | maintenance part 14 Coolant path 23 Cylinder chamber 25 Cleaning path H Clearance

Claims (1)

A taper hole in which the tool holder is detachably mounted is formed at the tip of the main shaft, and a holding portion for clamping the tool holder mounted in the taper hole is formed in a through hole formed so as to be continuous with the taper hole. A draw bar provided is inserted so as to be movable in the axial direction, a coolant passage capable of communicating with a coolant flow path of the tool holder is provided in the holding portion, and a coolant supply hole capable of supplying a coolant is provided in the passage. In the spindle device, a part of the coolant supplied to the tool holder attached to the spindle is formed between the front end face of the large diameter part provided in the draw bar and the front end face of the large diameter hole provided in the through hole. A spindle device characterized in that a cleaning passage is provided so that is supplied from the cylinder chamber to a gap between the tool holder and the tapered hole.

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