JP2011000661A - Tool holder - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide a tool holder having a simple configuration, enabling the automatic replacement of tools, having the high suction efficiency of cutting powder, and preventing internal accumulation.SOLUTION: The tool holder 4 has a mounting hole 19b opened to a tip face 19a and allowing a cutting tool 12 to be attached to and a clamp hole 14d communicating with the mounting hole 19b and opened to a proximal end face, and is attached to a main shaft 3 of a machine tool. The tool holder 4 has a suction hole a3 formed to be opened to the tip face 19a and to communicate with the clamp hole 14d.

Description

  The present invention relates to a tool holder, and more particularly to a tool holder that can improve the recovery efficiency of dust-like cutting powder generated particularly during processing of light metal or carbon material.

  For example, Patent Document 1 discloses a milling tool that enables recovery of dust-like cutting powder generated when a magnesium alloy is cut. This milling tool has a tip lead-out passage formed in the shaft core of the shank, and the tip lead-out passage communicates with the suction hopper.

JP 2005-532917 A

  In the milling tool described in Patent Document 1, since the cutting powder is sucked by the tip lead-out passage formed in the shaft core of the shank, the diameter of the tip lead-out passage is reduced when the shank diameter is reduced. There is a problem that the resistance increases and the cutting powder cannot be sufficiently sucked. In the case of the conventional milling tool, since the passage area in the suction hopper is larger than the cross-sectional area of the tip lead-out passage, the flow rate of the suction air is reduced in the suction hopper portion, and the cutting powder is precipitated in this portion. In addition, there are concerns about problems such as accumulation. Furthermore, since the suction hopper is provided, there is a problem that the structure is complicated and the tool cannot be automatically changed due to the structure.

  The present invention has been made in view of the above-mentioned conventional problems, and provides a tool holder that has high cutting powder suction efficiency, can prevent internal accumulation of cutting powder, and can automatically change tools. It is an issue.

  The invention of claim 1 has a mounting hole that opens to the front end surface and can be attached to a cutting tool, and a clamp hole that communicates with the mounting hole and opens to the base end surface, and is attached to the spindle of the machine tool. The tool holder is characterized in that it has a suction hole that opens to the tip surface and is formed to communicate with the clamp hole.

  The invention of claim 2 is the tool holder according to claim 1, further comprising a cover member that surrounds the periphery of the tip surface of the tool holder and extends to the vicinity of the tip of the blade attached to the mounting hole. It is said.

  Invention of Claim 3 is provided in the tool holder of Claim 1 or 2 so that it may rotate between the said front end surface and the front-end | tip of the said blade tool with the said tool holder, and rotation of the said tool holder Along with this, a blade member that pressurizes and blows air toward the suction hole is provided.

  In the first aspect of the present invention, since the suction hole is formed in the tip surface of the tool holder so as to communicate with the clamp hole, the distance from the cutting point to the opening of the suction hole is reduced, and at a position close to the cutting edge. As a result, suction efficiency can be improved. In addition, since the suction hole is formed in the tool holder, not the cutting tool itself, a suction hole having a necessary cross-sectional area can be provided even in the case of a small-diameter cutting tool, and suction efficiency can be improved.

  In the invention of claim 2, since the cover member surrounding the tip surface of the tool holder and extending to the vicinity of the tip of the cutting tool is provided, the flow velocity near the cutting point where the cutting powder is generated can be increased, and the suction efficiency can be increased. It can be further improved.

  In the invention of claim 3, since the blade member that rotates together with the tool holder is provided between the tip surface of the tool holder and the tip of the cutting tool, the blade member rotates with the cutting process, so that the air near the cutting point is Can be pressurized and blown toward the suction hole to reliably feed the cutting powder into the suction hole, and the suction efficiency can be further improved.

It is a cross-sectional side view of the main spindle apparatus provided with the tool holder which concerns on Example 1 of this invention. It is a cross-sectional side view of the clamp part of the tool holder of the said spindle apparatus. It is a partial cross section side view of the said tool holder. It is the side view and A arrow directional view of the cutting tool with which the said tool holder is mounted | worn. FIG. 5 is a cross-sectional bottom view of the tool holder (a cross-sectional view taken along line VV in FIG. 3). FIG. 4 is a cross-sectional bottom view of the tool holder (a cross-sectional view taken along line VI-VI in FIG. 3). It is a partial cross section side view which shows the modification of the said tool holder.

  Embodiments of the present invention will be described below with reference to the accompanying drawings. FIGS. 1-6 is a figure for demonstrating the tool holder which concerns on Example 1 of this invention.

  In the figure, reference numeral 1 denotes a spindle device provided in a machine tool such as a vertical machining center. The spindle device 1 includes a spindle head 2 supported by a column, a spindle 3 rotatably supported by the spindle head 2, a tool holder 4 supported at a tip portion of the spindle 3, and the tool holder 4. And a clamping mechanism 5 for clamping and unclamping to the main shaft 3.

  The main shaft 3 is formed of a cylindrical body having a through hole 3a at the axis. A lower part and an upper part of the main shaft 3 are rotatably supported by the main shaft head 2 via a lower bearing 6a and an upper bearing 6b. A tapered hole 3b is formed at the lower end of the through hole 3a of the main shaft 3, and the tool holder 4 is fitted and fixed in the tapered hole 3b. Although not shown, an electric motor that rotationally drives the main shaft 3 is disposed between the main shaft 3 and the main shaft head 2.

  The clamp mechanism 5 is inserted and disposed in the through hole 3a of the main shaft 3, and the draw bar 7 that clamps or unclamps the tool holder 4 in the tapered hole 3b, and moves the draw bar 7 in the unclamping direction. And a drive mechanism (cylinder mechanism) 8.

  The draw bar 7 is formed with a cylindrical engagement drive pipe 9 that is formed at the upper end portion of the tool holder 4 and engages with an engagement step portion 14a. The engagement claw 11 is disposed near the tapered hole 3b. And a cylindrical drawbar body 10 connected to the engagement drive pipe 9.

  The engaging claw 11 is configured such that the front end claw portion 11b can be expanded in the radial direction around the base end portion 11a. A cam 9a is formed at the front end of the engagement drive pipe 9. The cam 9a is in sliding contact with the inner surface of the claw portion 11b, and engages the claw portion 11b when it is in a reverse position (upward position in FIG. 1). Engage with the stepped portion 14a and release the engagement when in the forward position (downward position in FIG. 1).

  A large number of disc springs 15 are interposed between the draw bar main body 10 and the through hole 3 a of the main shaft 3. The disc spring 15 biases the draw bar 7 in the clamping direction (upward in FIG. 1). When the engagement drive pipe 9 is moved in the clamping direction by this urging force, the cam 9a expands the claw portion 11b to engage the engagement step portion 14a, and the taper portion 14b of the tool holder 4 is moved to the taper hole. Fit firmly into 3b.

  The drive mechanism 8 has a structure in which a piston 18d is inserted and arranged in a cylinder hole 18c formed by a casing 18a fastened and fixed to the upper end portion of the spindle head 2 by a bolt 8a and a lid member 18b. When hydraulic pressure is supplied to the oil chamber b, the piston 18d moves downward in FIG. 1, and the draw bar 7 is unclamped against the urging force of the disc spring 15 via the pressing plate 24 (lower in FIG. 1). And the fitting between the tapered portion 14b of the tool holder 4 and the tapered hole 3b is released.

  An upper end portion 9b of the engagement drive pipe 9 constituting the lower portion of the draw bar 7 is inserted into a lower end portion 10a of the draw bar main body 10 constituting the upper portion and screwed into the inner surface thereof.

  A connecting pipe 17 is inserted into the cam 9a of the engagement drive pipe 9 so as to be coaxial, and the connecting pipe 17 is fixed in the tool holder 4 by a nut member 17a.

  Furthermore, the upper end portion 10 b of the draw bar main body 10 is inserted into the lower end portion 16 a of the inner pipe 16 of the drive mechanism 8. The inner pipe 16 is inserted into the lid member 18b and fixed to the lid member 18b.

  A seal mechanism 21 is provided between the inner pipe 16 and the upper end portion 10 b of the draw bar main body 10 to prevent air from being sucked into the inner pipe 16 from the outside.

  A fourth suction hole a4 is formed in the axial core portion of the connecting pipe 17, the draw bar 7, and the inner pipe 16 so as to penetrate them in the axial direction. The fourth suction hole a4 is set to have substantially the same diameter in the inner portion of the connecting pipe 17, the inner portion of the engagement drive pipe 9, the inner portion of the draw bar main body 10, and the inner pipe 16 portion. A suction device 16 c is connected to the upper end portion 16 b of the inner pipe 16.

  The tool holder 4 has a structure in which two parts made of different materials, such as a holding part 19 that holds the cutting tool 12 and a clamp part 14 that is clamped to the main shaft 3, are joined by press-fitting or the like. The holding part 19 has a base part 19d and a fitting part 19c extending downward from the base part 19d so as to be close to the cutting edge 12a of the cutting tool 12. The fitting portion 19c is provided on the shaft core so as to open to the tip end surface 19a thereof, and has a mounting hole 19b to which the blade 12 is fixed by shrink fitting or the like. The clamp portion 14 is provided on the shaft core so as to open to the base end surface 14c thereof, and has a clamp hole 14d into which the engagement claw 11, the connection pipe 17 and the like are inserted. The mounting hole 19b of the holding part 19 communicates with the clamp hole 14d through a second suction hole a2 formed in the axial center of the holding part 19.

  The cutting tool 12 includes a cutting edge 12a portion and a shank portion 12b, and a first suction hole a1 is formed in the axial center of the shank portion 12b. Two suction ports 12c and 12c communicating with the first suction hole a1 are formed at a boundary portion between the cutting edge 12a and the shank portion 12b. The first suction hole a1 communicates with the fourth suction hole a4 via a second suction hole a2 formed in the holding portion 19.

  The holding portion 19 is formed with six third suction holes a3 that open to the distal end surface 19a so as to surround the mounting hole 19b. The third suction hole a3 has a length that covers substantially the entire length of the holding portion 19, and is inclined toward the axial center near the upper end portion of the fitting portion 19c and communicates with the second suction hole a2. Yes.

  As shown in FIG. 7, the third suction hole a <b> 3 is formed so as to be inclined from the front end surface 19 a of the holding portion 19 toward the second suction hole a <b> 2, so that the third suction hole a <b> 3 is close to the front end surface 19 a. You may make it connect with the said 2nd suction hole a2. If it does in this way, the flow path resistance in this part can be reduced by the part for which the 3rd suction hole a3 became short.

  The holding part 19 of the tool holder 4 is provided with a cover member 25 that surrounds the periphery of the fitting part 19c and extends to the vicinity of the cutting edge 12a of the cutting tool 12. The cover member 25 includes a cylindrical portion 25 a that surrounds the fitting portion 19 c and a flange portion 25 b that is formed at a proximal end portion of the cylindrical portion 25 a, and the flange portion 25 b is a base portion of the holding portion 19. It is fixed to the holding part 19 by a nut member 26 screwed into 19d. Further, a small diameter portion 25c extending further downward is formed at the lower end portion of the cylindrical portion 25a. The small diameter portion 25c surrounds the periphery of the cutting tool 12.

  In the tool holder 4, an impeller (blade member) 27 is located between the tip surface 19 a of the tool holder 4 and the tip of the blade 12, preferably in the small diameter portion 25 c of the cover member 25. And to rotate together with the tool holder 4. The impeller 27 is made of metal such as iron and has a ring-shaped boss portion 27a and a blade 27b integrally formed on the boss portion 27a so as to extend radially from the boss portion 27a. The boss portion 27a is fixed to the shank portion 12b of the blade 12 by shrink fitting or the like. Here, when setting the number and shape of the blades 27b of the impeller 27, it is preferable not to cover the third suction hole a3 as much as possible.

  The impeller 27 may be attached to the cover member 25 or the holding portion 19 of the tool holder 4 or may be formed integrally with the cover member 25.

  In this embodiment, the workpiece is cut by the cutting tool 12, and the air near the cutting point by the cutting tool 12 is sucked by the suction device 16c. Thereby, the cutting powder generated at the cutting point is sucked from the first suction hole a1 and the third suction hole a3, and sucked to the suction device 16c through the second suction hole a2 and the fourth suction hole a4. .

  In the present embodiment, since the third suction hole a3 is formed so as to open in the tip surface 19a close to the cutting point of the tool holder 4, the distance from the cutting point to the opening of the third suction hole a3 is It becomes small and suction at a position close to the cutting point is possible, and the suction efficiency can be improved accordingly.

  Further, since the third suction hole a3 is formed in the tool holder 4 in addition to the first suction hole a1 provided in the cutting tool 12, since the cutting tool has a small diameter, the first suction hole must be reduced in diameter. Even when there is no suction hole or when the suction hole cannot be formed in the cutting tool, a necessary passage area can be secured by the third suction hole a3, and suction efficiency can be improved.

  Moreover, since the cover member 25 surrounding the tip end portion of the tool holder 4 and extending to the vicinity of the cutting edge 12a of the cutting tool 12 is provided, the flow velocity near the cutting point where the cutting powder is generated can be increased, and the suction efficiency can be further increased. It can be further improved.

  Furthermore, since the impeller 27 that rotates together with the tool holder 4 is provided between the tip surface of the tool holder 4 and the tip of the cutting tool 12, the blade 27b rotates along with the cutting process, so The air is pressurized and blown toward the third suction hole a3, and the cutting powder can be reliably fed into the third suction hole a3, so that the suction efficiency can be further improved.

DESCRIPTION OF SYMBOLS 1 Machine tool 3 Spindle 4 Tool holder 12 Cutting tool 14d Clamp hole 19a Tip surface 19b Mounting hole 25 Cover member 27 Impeller (blade member)
a3 Third suction hole (suction hole)

Claims (3)

In a tool holder attached to a spindle of a machine tool, having a mounting hole that opens to a distal end surface and that can be attached to a cutting tool, and a clamp hole that communicates with the mounting hole and opens to a proximal end surface.
The tool holder has a suction hole that opens to the tip surface and is formed to communicate with the clamp hole. The tool holder according to claim 1, wherein
A tool holder comprising a cover member that surrounds the periphery of the tip surface of the tool holder and extends to the vicinity of the tip of a cutting tool attached to the mounting hole. The tool holder according to claim 1 or 2,
A blade member is provided between the tip surface and the tip of the cutting tool so as to rotate together with the tool holder, and includes a blade member that pressurizes and blows air toward the suction hole as the tool holder rotates. A tool holder characterized by that.

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