Tool holder

Abstract

A technique is provided to suppress the reduction of the inner diameter of the tool insertion space caused by the force of the tool holder. A pressure chamber (123a, 123b) is formed between the inner circumferential surface (111) of the main body member (110) and the outer circumferential surface (122) of the sleeve (120). A gripping portion (124a, 124b) is formed between the outer circumferential surface (122) and the inner circumferential surface (121) of the sleeve, which is capable of elastically deforming radially inward by the increase of pressure within the pressure chamber (123a, 123b). An extension chamber (123d) is formed between the outer circumferential surface (122) of the sleeve and the inner circumferential surface (111) of the main body member, which communicates with the rear end of the pressure space (123a) and extends axially and circumferentially. The extension chamber (123d) is configured to suppress the radial inward elastic deformation of the portion of the inner circumferential surface (121) of the main body member corresponding to the gripping part (124a) caused by the pressing force borne by the outer circumferential surface (112) of the main body member, thereby reducing the inner diameter of the inner space (120a) of the sleeve that forms the tool insertion space.

Description

Technical Field

[0001] This invention relates to a tool holder for holding a cutting tool. Background Technology

[0002] As a tool holder for holding a tool, a tool holder utilizing fluid pressure is used. For example, a tool holder utilizing fluid pressure is disclosed in Patent Document 1 (International Publication No. 2012-160664).

[0003] Patent Document 1 discloses a tool holder comprising a main body and a sleeve inserted into the inner space of the main body. Furthermore, the tool holder has a retaining portion for holding the tool (specifically, the shank of the tool). The retaining portion includes: a pressure chamber formed between the inner circumferential surface of the main body and the outer circumferential surface of the sleeve; and a thin-walled gripping portion formed between the pressure chamber and the inner circumferential surface of the sleeve. By increasing the pressure within the pressure chamber, the gripping portion elastically deforms radially inward. Consequently, the tool (shank) inserted into the inner space of the sleeve is clamped by the portion of the inner circumferential surface of the sleeve corresponding to the gripping portion.

[0004] Prior art literature

[0005] Patent documents

[0006] Patent Document 1: International Publication No. 2012-160664 Summary of the Invention

[0007] The problem the invention aims to solve

[0008] Consider configuring a tool holder that utilizes fluid pressure as, for example... Figures 5-7 As shown. Figure 5 It is a cross-sectional view of the tool holder 400 being clamped in the tool holder inner space (tool holder insertion space) 300a of the tool holder 300. Figure 6 It is Figure 5 The main part is enlarged. Figure 7 yes Figure 5 Sectional view along line VII-VII.

[0009] The tool holder 400 includes a main body member 410 and a sleeve 420. The holding portion of the tool holder 400 has pressure chambers 423a and 423b, and thin-walled gripping portions 424a and 424b. The pressure chambers 423a and 423b are formed between the outer peripheral surface 422 (outer peripheral surface portions 422b and 422d) of the sleeve 420 and the inner peripheral surface 411 (inner peripheral surface portion 411c) of the main body member 410. The gripping portions 424a and 424b are formed between the outer peripheral surface 422 (outer peripheral surface portions 422b and 422d) of the sleeve 420 and the inner peripheral surface 421 (inner peripheral surface portion 421a). Furthermore, the sleeve outer peripheral surface portion 422a formed at the rear end and the sleeve outer peripheral surface portion 422e formed at the front end of the sleeve outer peripheral surface 422 are brazed to the inner peripheral surface 411 (inner peripheral surface portion 411c of the main body component). The tool shank of the tool 200 is inserted into the tool insertion space formed by the inner space 410a of the main body component and the inner space 420a of the sleeve. With the tool shank inserted into the tool insertion space, the pressure in the pressure chambers 423a and 423b is increased, causing the gripping portions 424a and 424b to elastically deform radially inward. As a result, the tool shank is clamped by the portion of the inner peripheral surface 421 (inner peripheral surface portion 421a of the sleeve) corresponding to the gripping portions 424a and 424b.

[0010] The tool holder 400 is clamped between the front end faces 305a and 306a of the fastening screws 305 and 306 and the inner circumferential surface 301 of the tool holder.

[0011] In recent years, with the use of smaller diameter cutting tools, the radial width of the tool holder has become smaller. If the radial width of the tool holder decreases, there is a concern that the inner circumferential surface of the tool holder may elastically deform radially inward due to the pressing force used to hold the tool holder. If the inner circumferential surface of the tool holder elastically deforms radially inward, there is a concern that the inner diameter of the tool insertion space formed by the inner circumferential surface of the tool holder will decrease, making it difficult to insert the tool into the tool insertion space.

[0012] For example, in Figures 5-7 In the tool holder 400 shown, if the radial width of the axially extending portions of the main body member 410 and the sleeve 420 becomes smaller, there is a concern that the pressing force generated by the fastening screws 305 and 306 will be transmitted to the sleeve 420 via the main body member 410. In this case, the outer peripheral surface portion 412c of the main body member, the inner peripheral surface portion 411c of the main body member, the outer peripheral surface portions 422a and 422b of the sleeve, and the inner peripheral surface portion 421a of the sleeve are as follows: Figure 6 , Figure 7The sleeve undergoes radially inward elastic deformation as shown by the dashed lines (refer to dashed lines 412c1, 411c1, 422a1, 442b1, 421a1). If the radially inward elastic deformation of the inner circumferential surface portion 421a of the sleeve is large, the inner diameter of the inner sleeve space 420a, which constitutes the tool insertion space, decreases. If the inner diameter of the inner sleeve space 420a decreases, it becomes difficult to insert the tool shank of the tool 200 into the tool insertion space (inner sleeve space 420a).

[0013] The present invention is made in view of this point, and aims to provide a technique that can suppress the reduction of the inner diameter of the tool insertion space of the tool holder caused by the force of the tool holder.

[0014] Solutions for solving problems

[0015] The present invention relates to a tool holder formed in the shape of a cylindrical part extending axially, which is clamped in a state of being inserted into the tool holder insertion space of the tool holder mounting part.

[0016] The tool holder of the present invention has an outer peripheral surface and an inner peripheral surface forming a tool insertion space, and the tool holder has a retaining portion. The tool holder of the present invention can be composed of a single component or multiple components. Furthermore, various methods can be used as methods for clamping the tool holder.

[0017] The retaining portion is the part that holds the cutting tool (more specifically, the shank of the cutting tool). In this invention, the retaining portion has at least one pressure chamber and at least one gripping portion. The pressure chamber extends axially and circumferentially. The gripping portion is formed between the pressure chamber and the inner circumferential surface of the cutting tool retainer, and extends axially and circumferentially. The pressure chamber is filled with a fluid as a pressurizing medium. For example, oil is filled in. The pressure chamber and the gripping portion are configured such that by increasing the pressure inside the pressure chamber, the gripping portion can be elastically deformed radially inward. For example, the gripping portion is formed to be relatively thin.

[0018] Furthermore, the tool holder has an extension chamber that communicates with the rear end of one of the at least one pressure chambers formed on the rear end side and extends axially and circumferentially. The radial width of the extension chamber is set to be smaller than the radial width of the pressure chamber formed on the rear end side. Additionally, the radial width between the extension chamber and the inner circumferential surface of the tool holder is set to be larger than the radial width between the pressure chamber formed on the rear end side and the inner circumferential surface of the tool holder. When one pressure chamber is formed, the rear end of the pressure chamber corresponds to the "rear end of the pressure chamber formed on the rear end side". Furthermore, the extension chamber is configured to suppress the radially inward elastic deformation of the portion of the inner circumferential surface of the tool holder corresponding to the gripping portion formed on the rear end side caused by the force borne by the outer circumferential surface of the tool holder when the tool holder is inserted into the tool holder insertion space of the tool holder mounting portion. For example, the radial width and axial length of the extension chamber are set such that, when the conventional clamping force required for machining with a tool is applied to the outer circumferential surface of the tool holder, the inner diameter of the tool insertion space will not be smaller than the outer diameter of the tool shank. By providing an extension chamber that communicates with the rear end of the pressure chamber formed on the rear end side, it is possible to suppress the transmission of force borne on the outer circumferential surface of the tool holder to the inner circumferential surface of the tool holder.

[0019] In this invention, the reduction in the inner diameter of the tool insertion space caused by the force borne by the outer peripheral surface of the tool holder that clamps the tool holder can be suppressed.

[0020] In different embodiments of the present invention, the tool holder includes a main body and a sleeve.

[0021] The main component is formed as a cylindrical shape extending along the axial direction, and has an outer peripheral surface of the main component and an inner peripheral surface of the main component forming the inner space of the main component.

[0022] The sleeve is formed as a cylindrical shape extending axially, and has an outer circumferential surface and an inner circumferential surface forming an inner space within the sleeve. The outer circumferential surface has: a first outer circumferential surface portion extending axially and circumferentially at the rear end side and a second outer circumferential surface portion extending axially and circumferentially at the front end side. The outer circumferential surface also has: a fourth outer circumferential surface portion extending axially and circumferentially between the first and second outer circumferential surface portions and at least one third outer circumferential surface portion. The fourth outer circumferential surface portion connects to the rear end of the third outer circumferential surface portion formed at the rear end side and the front end of the first outer circumferential surface portion, and is radially inwardly recessed compared to the first and second outer circumferential surface portions. The at least one third outer circumferential surface portion is radially inwardly recessed compared to the fourth outer circumferential surface portion. In this design, the radially outer portion of the fourth sleeve's outer circumferential surface is connected to the rear end of the third sleeve's outer circumferential surface portion formed on the rear end side.

[0023] With the sleeve inserted into the inner space of the main component, the outer peripheral surfaces of the first sleeve and the second sleeve are fixed to the inner peripheral surface of the main component. Various fixing methods can be used. For example, brazing can be used.

[0024] The inner circumferential surface of the tool holder is formed by the inner circumferential surface of the main body component and the inner circumferential surface of the sleeve. The outer circumferential surface of the tool holder is formed by the outer circumferential surface of the main body component. At least one pressure chamber is formed by at least one third outer circumferential surface portion of the outer circumferential surface of the sleeve and the inner circumferential surface of the sleeve. Additionally, an extension chamber is formed by a fourth outer circumferential surface portion of the outer circumferential surface of the sleeve and the inner circumferential surface of the main body component.

[0025] In this solution, tool holders can be easily manufactured.

[0026] The effects of the invention

[0027] In the tool holder of the present invention, the reduction in the inner diameter of the tool insertion space of the tool holder caused by the force holding the tool holder can be suppressed. Attached Figure Description

[0028] Figure 1 This is a cross-sectional view showing an embodiment of the tool holder of the present invention mounted on a tool holder.

[0029] Figure 2 This is a cross-sectional view of one embodiment of the tool holder of the present invention.

[0030] Figure 3 It is Figure 1 The main part is enlarged.

[0031] Figure 4 yes Figure 1 Sectional view along line IV-IV.

[0032] Figure 5 This is a cross-sectional view showing the existing tool holder mounted on the tool holder.

[0033] Figure 6 It is Figure 5 The main part is enlarged.

[0034] Figure 7 yes Figure 5 Sectional view along line VII-VII. Detailed Implementation

[0035] The following detailed description is merely to provide those skilled in the art with information on preferred applications for carrying out the invention. The scope of protection of the invention is not limited by the detailed description, but is determined based on the claims. Therefore, the combinations of structures and methods described in the following detailed description are not all necessary for carrying out the invention in a broad sense, but are only used to disclose representative aspects of the invention in the detailed description accompanied by the reference numerals in the accompanying drawings.

[0036] The embodiments of the present invention will be described below with reference to the accompanying drawings.

[0037] In this specification, the extending direction of the tool holder mounting part (tool holder) and the extending direction of the tool holder (main body component, sleeve) in the state of being mounted on the tool holder mounting part (in... Figures 1-3 The left-right direction (the extension direction of the centerline P) is called the "axial direction". Furthermore, in a cross-section orthogonal to the axial direction (the extension direction of the centerline P), the direction along the circle centered on the centerline P is called the "circumferential direction", and the direction of the line passing through the centerline P is called the "radial direction". Additionally, the side where the tool holder is inserted into the tool holder insertion space of the tool holder mounting part along the axial direction, and the side where the tool is inserted into the tool insertion space of the tool holder (in...) Figures 1-3 , Figure 5 , Figure 6 The side marked with arrow A (right side) is called the "front end side," and the side opposite to the front end side (in...) Figures 1-3 , Figure 5 , Figure 6 The side with arrow B in the middle (left side) is called the "rear end side".

[0038] Reference Figures 1-4 An embodiment of the tool holder of the present invention will be described. In this embodiment, a tool holder mounted on a tool holder will be described.

[0039] Figure 1 This is a cross-sectional view showing the state in which the tool holder 100 is mounted on the tool holder 300 according to one embodiment. Figure 2 This is a cross-sectional view of a tool holder 100 according to one embodiment. Figure 3 It is Figure 1 The main part is enlarged. Figure 4 yes Figure 1 Sectional view along line IV-IV.

[0040] First, the tool holder 300 on which the tool holder 100 of this embodiment is installed will be described.

[0041] The tool holder 300 has an inner peripheral surface 301, an outer peripheral surface 302, and a front end surface 300A.

[0042] An inner space 300a extending axially is formed by the inner circumferential surface 301 of the tool holder. The inner space 300a has an opening that opens at the front end face 300A of the tool holder. The tool holder 100 is inserted into the inner space 300a of the tool holder through the opening.

[0043] Additionally, the tool holder 300 has holes 303 and 304 that extend radially between the inner circumferential surface 301 and the outer circumferential surface 302 of the tool holder. Holes 303 and 304 have openings 303a and 304a that open onto the inner circumferential surface 301 of the tool holder. Fastening screws 305 and 306 are radially movable and inserted into holes 303 and 304. The fastening screws 305 and 306 can protrude radially inward relative to the inner circumferential surface 301 of the tool holder through the openings 303a and 304a.

[0044] With the tool holder 100 installed on the tool holder 300, and with the tool holder 100 inserted into the inner space 300a of the tool holder, the fastening screws 305 and 306 are moved radially inward. Then, by bringing the front faces 305a and 306a of the fastening screws abut against the tool holder 100, the tool holder 100 is pressed radially inward. As a result, the tool holder 100 is clamped between the front faces 305a and 305b of the fastening screws and the inner circumferential surface 301 of the tool holder.

[0045] In this embodiment, the tool holder 300 corresponds to the "tool holder mounting portion" of the present invention. Furthermore, the inner peripheral surface 301 of the tool holder corresponds to the "inner peripheral surface of the tool holder mounting portion" of the present invention, the outer peripheral surface 302 of the tool holder corresponds to the "outer peripheral surface of the tool holder mounting portion" of the present invention, and the front end surface 300A of the tool holder corresponds to the "front end surface of the tool holder mounting portion" of the present invention. Additionally, the inner space 300a of the tool holder corresponds to the "inner space of the tool holder mounting portion" or the "tool holder insertion space" of the present invention.

[0046] Next, the tool holder 100 of this embodiment will be described. The tool holder 100 of this embodiment includes a main body member 110 and a sleeve 120. The main body member 110 and the sleeve 120 are formed of a metal capable of elastic deformation, such as steel.

[0047] The main component 110 is formed as a cylindrical shape extending along the axial direction.

[0048] The main component 110 has an inner peripheral surface 111, an outer peripheral surface 112, a front end surface 110A, and a rear end surface 110B. The inner peripheral surface 111 forms an axially extending inner space 110a.

[0049] The inner circumferential surface 111 of the main component has inner circumferential surface portions 111a to 111c.

[0050] The inner circumferential surface portions 111a and 111c of the main component extend axially and have a circular cross-section. The inner diameter of the inner circumferential surface portion 111c is larger than that of the inner circumferential surface portion 111a. The inner circumferential surface portion 111b of the main component extends radially. The inner circumferential surface portion 111b is a stepped surface that connects the inner circumferential surface portions 111a and 111c of the main component.

[0051] The outer peripheral surface 112 of the main component has portions 112a to 112d.

[0052] The outer peripheral surface portion 112a of the main component extends axially and has a circular cross-section. The outer peripheral surface portion 112c of the main component is a notch surface obtained by cutting an opening in the outer peripheral surface portion 112a of the main component, and extends axially (see reference). Figure 4 The outer peripheral surface portion 112c of the main component is formed as a flat surface that can abut against the front end faces 305a and 306a of the fastening screws 305 and 306. The outer peripheral surface portion 112c of the main component is pressed radially inward by the front end faces 305a and 306a of the fastening screws, thereby mounting the tool holder 100 onto the tool holder 300.

[0053] The outer peripheral surface portion 112b of the main component extends radially. The outer peripheral surface portion 112d of the main component is a notched surface obtained by cutting a notch in the outer peripheral surface portion 112b of the main component. A radially extending flange 113 is formed by the outer peripheral surface portion 112b, the outer peripheral surface portion 112d of the main component, and the front end face 110A of the main component. The flange 113 is used to restrict the insertion position of the tool holder 100 within the inner space 300a of the tool holder.

[0054] Holes 114 and 116 are formed in the flange 113 of the main body member 110. Holes 114 and 116 have openings that open into the inner circumferential surface 111 (inner circumferential surface portion 111c) of the main body member and extend radially.

[0055] A screw (pressure screw) 115 for adjusting the pressure in pressure chambers 123a and 123b (described later) is disposed in hole 114. A screw 117 is disposed in hole 116 through a steel ball 118. Hole 116 is used when injecting pressurizing medium into pressure chambers 123a and 123b or when discharging pressurizing medium from pressure chambers 123a and 123b.

[0056] The sleeve 120 is formed as a cylindrical shape extending along the axial direction.

[0057] The sleeve 120 has an inner circumferential surface 121, an outer circumferential surface 122, a front end surface 120A, and a rear end surface 120B. An inner space 120a extending axially is formed by the inner circumferential surface 121.

[0058] The inner circumferential surface 121 of the sleeve has inner circumferential surface portions 121a to 121c. Inner circumferential surface portions 121a and 121c extend axially and have circular cross-sections. The inner diameter D2 of the inner circumferential surface portion 121c is smaller than the inner diameter D1 of the inner circumferential surface portion 121a (see reference). Figure 3 The inner circumferential surface portion 121b of the sleeve is a stepped surface connecting the inner circumferential surface portions 121a and 121c of the sleeve. The inner circumferential surface portion 121b is formed at the junction (rear end of the gripping portion 124a) between the outer circumferential surface portions 122b and 122c of the sleeve, which will be described later. A groove 125 for the flow of cooling medium for cooling the tool 200 is formed in a spiral shape on the inner circumferential surface portion 121c. Furthermore, the shape of the groove 125 is not limited to a spiral shape.

[0059] The outer peripheral surface 122 of the sleeve has a sleeve outer peripheral surface portion 122a to 122f with a cross-section formed as a circle.

[0060] The outer peripheral surface portion 122a is formed on the rear end side (arrow B side) of the outer peripheral surface 122 of the sleeve, and the outer peripheral surface portion 122f is formed on the front end side (arrow A side) of the outer peripheral surface 122 of the sleeve. The outer peripheral surface portions 122a and 122f have the same outer diameter and extend along the axial and circumferential directions.

[0061] Outer circumferential surface portions 122c and 122e of the sleeve are formed between outer circumferential surface portions 122a and 122f, and extend along the axial and circumferential directions. Outer circumferential surface portion 122e is formed at a position further back than outer circumferential surface portion 122f, and outer circumferential surface portion 122c is formed at a position further back than outer circumferential surface portion 122e. The outer diameter of outer circumferential surface portions 122c and 122e is [D2 + 2 × M2] (refer to...). Figure 3 The outer diameter of the sleeve outer circumferential surfaces 122a and 122f is set to [D1+2×M1+2×N1] (refer to...). Figure 3 Smaller. That is, the outer peripheral surface portions 122c and 122e of the sleeve are formed as concave surfaces that are recessed radially inward compared to the outer peripheral surface portions 122a and 122f of the sleeve. In addition, stepped surfaces are formed on both axial ends (front end and rear end) of the outer peripheral surface portions 122c and 122e of the sleeve.

[0062] A sleeve outer peripheral surface portion 122d is formed between sleeve outer peripheral surface portions 122c and 122e, and extends along both the axial and circumferential directions. The outer diameter of the sleeve outer peripheral surface portion 122d is configured to allow the pressurized medium to pass through via a communication path 123c (described later) connecting pressurized chambers 123a and 123b. In this embodiment, the outer diameter of the sleeve outer peripheral surface portion 122d is set to be smaller than that of sleeve outer peripheral surface portions 122a and 122f, and larger than that of sleeve outer peripheral surface portions 122c and 122e.

[0063] A sleeve outer circumferential surface portion 122b is formed between sleeve outer circumferential surface portions 122c and 122a, and extends along both the axial and circumferential directions. The outer diameter of the sleeve outer circumferential surface portion 122b is set to be smaller than the outer diameter [D1+2×M1+2×N1] of the sleeve outer circumferential surface portion 122a, and larger than the outer diameter [D2+2×M2] of the sleeve outer circumferential surface portion 122c. That is, the sleeve outer circumferential surface portion 122b is formed at a position on the radially outer side, which is further from the rear end of the sleeve outer circumferential surface portion 122c.

[0064] Thin-walled gripping portions 124a and 124b capable of radial elastic deformation are formed between the outer peripheral surfaces 122c and 122e of the sleeve and the inner peripheral surface 121 (inner peripheral surface 121c of the sleeve). Figure 3 In the figure, reference numeral M2 indicates the radial width of the gripping portions 124a and 124b.

[0065] In this embodiment, the outer peripheral surface portion 122a of the sleeve corresponds to the "first outer peripheral surface portion" or "first sleeve outer peripheral surface portion" of the present invention, and the outer peripheral surface portion 122f of the sleeve corresponds to the "second outer peripheral surface portion" or "second sleeve outer peripheral surface portion" of the present invention. Furthermore, the outer peripheral surface portions 122c and 122e of the sleeve correspond to the "at least one third outer peripheral surface portion" or "at least one third sleeve outer peripheral surface portion" of the present invention. Additionally, the outer peripheral surface portion 122c of the sleeve corresponds to the "third outer peripheral surface portion formed on the rear end side" or "third sleeve outer peripheral surface portion formed on the rear end side" of the present invention, and the outer peripheral surface portion 122b of the sleeve corresponds to the "fourth outer peripheral surface portion" or "fourth sleeve outer peripheral surface portion" of the present invention.

[0066] The sleeve 120 is inserted into the inner space 110a of the main body member until the rear end face 120B of the sleeve abuts against the inner circumferential surface portion 111b of the main body member. Furthermore, the sleeve is configured such that, with the rear end face 120B of the sleeve abutting against the inner circumferential surface portion 111b of the main body member, the holes 114 and 116 communicate with any of the pressurized chambers (pressurized chamber 123b in this embodiment).

[0067] Furthermore, the sleeve 120 is fixed to the main body component 110. In this embodiment, the rear end face 120B of the sleeve is brazed to the inner circumferential surface portion 111b of the main body component, and the outer circumferential surface portions 122a and 122f of the sleeve are brazed to the inner circumferential surface portion 111c of the main body component.

[0068] Thus, a sealed region for injecting pressurized medium is formed between the outer peripheral surface 122 of the sleeve and the inner peripheral surface 111 of the main component. That is, pressurized chambers 123a and 123b are formed between the outer peripheral surface portions 122c and 122e of the sleeve and the inner peripheral surface portion 111c of the main component. Pressurized chamber 123a is formed at a position further back than pressurized chamber 123b.

[0069] exist Figure 3 In the accompanying drawings, reference numeral N2 indicates the radial width of the pressurization chambers 123a and 123b. Additionally, reference numeral M2 indicates the radial width of the gripping portions 124a and 124b.

[0070] In addition, a connecting passage 123c is formed between the outer peripheral surface portion 122d of the sleeve and the inner peripheral surface portion 111c of the main component, which communicates with the pressurization chambers 123a and 123b.

[0071] Furthermore, between the outer circumferential surface portion 122b of the sleeve and the inner circumferential surface portion 111c of the main component, an extension chamber 123d is formed at a position further back than the pressurization chamber 123a, extending axially and circumferentially. The extension chamber 123d communicates with the pressurization chamber 123a at a radially outer portion on the rear end side of the pressurization chamber 123a.

[0072] The shape of the extension chamber 123d (width along the radial direction and length along the axial direction) is configured such that, when the conventional clamping force (pressing force radially inward) required for machining with the tool 200 is applied to the outer peripheral surface of the tool holder (outer peripheral surface portion 112c of the main body member), the inner diameter of the tool insertion space (inner sleeve space 120a) will not be smaller than the outer diameter of the tool shank of the tool 200. The shape of the extension chamber 123d is specifically configured so that, in particular, the inner diameter of the inner peripheral surface portion 121a of the sleeve does not become so large that it is difficult to insert the tool shank into the inner sleeve space 120a.

[0073] exist Figure 3 In the figure, reference numeral N1 indicates the radial width of the extension chamber 123d. Additionally, reference numeral M1 indicates the radial width between the outer circumferential portion 122b and the inner circumferential portion 121a of the sleeve.

[0074] In this embodiment, the "tool holder" of the present invention is constituted by the main body component 110 and the sleeve 120. Furthermore, the "inner peripheral surface of the tool holder" of the present invention is formed by the inner peripheral surface 111 of the main body component (inner peripheral surface portion 111a) and the inner peripheral surface 121 of the sleeve (inner peripheral surface portions 121a to 121c). Additionally, the "outer peripheral surface of the tool holder" of the present invention is formed by the outer peripheral surface 112 of the main body component. Furthermore, the "inner space of the tool holder" or "tool insertion space" of the present invention is formed by the inner space 110a of the main body component and the inner space 120a of the sleeve.

[0075] The pressurization chambers 123a and 123b, the connecting passage 123c, and the extension chamber 123d are filled with a pressurizing medium. In this embodiment, oil is used.

[0076] Furthermore, when holding the tool 200 (tool shank) inserted into the inner space 120a (tool insertion space) of the sleeve, the pressure screw 115 is operated to increase the pressure in the pressure chambers 123a and 123b. As a result, the gripping parts 124a and 124b elastically deform radially inward, and the tool 200 (tool shank) is clamped by the portion of the inner circumferential surface 121 (inner circumferential surface portion 121c of the sleeve) corresponding to the gripping parts 124a and 124b.

[0077] When inserting the tool 200 into the inner space 120a (tool insertion space) of the sleeve, or when withdrawing the tool 200 from the inner space 120a (tool insertion space) of the sleeve, the pressure screw 115 is operated to reduce the pressure in the pressure chambers 123a and 123b. As a result, the shape of the gripping parts 124a and 124b is restored to its normal state.

[0078] exist Figures 5-7In the tool holder 400 shown, even when the radial widths (the radial widths of the main body member 410 and the radial widths of the sleeve 420) are set to be large, there is no concern that inserting the tool (tool shank) into the tool insertion space (inner sleeve space 420a) will become difficult. That is, even if the outer peripheral surface of the tool holder (outer peripheral surface portion 412c of the main body member) is pressed radially inward by the front faces 305a and 306a of the fastening screws 305 and 306, there is little concern that the pressing force will be transmitted to the inner peripheral surface of the tool holder (inner peripheral surface portion 421a of the sleeve). Therefore, there is no concern that the inner peripheral surface of the tool holder (inner peripheral surface portion 421a of the sleeve) will elastically deform radially inward, and thus there is no concern that the inner diameter of the inner sleeve space 420a will decrease, making it difficult to insert the tool shank into the inner sleeve space 420a.

[0079] On the other hand, Figures 5-7 In the tool holder 400 shown, if the radial width (the radial width of the main body member 410 and the radial width of the sleeve 420) is set to be small, there is a concern that inserting the tool (tool shank) into the tool insertion space (inner space 420a of the sleeve) becomes difficult. That is, there is a concern that the pressing force on the outer peripheral surface of the tool holder (outer peripheral surface portion 412c of the main body member) is transmitted to the inner peripheral surface of the tool holder (inner peripheral surface portion 421a of the sleeve). In this case, due to the force applied to the outer peripheral surface portion 412c of the main body member, the outer peripheral surface portion 412c of the main body member, the inner peripheral surface portion 411c of the main body member, the outer peripheral surface portions 422a and 422b of the sleeve, and the inner peripheral surface portion 421a of the sleeve, as in... Figure 6 , Figure 7 As shown by the dashed line, it elastically deforms radially inward. Therefore, the inner diameter of the inner sleeve space 420a that constitutes the tool insertion space decreases, raising concerns that it will become difficult to insert the tool shank into the inner sleeve space 420a.

[0080] In contrast, in the tool holder 100 of this embodiment, if the radial width (the radial width of the main body member 110 and the radial width of the sleeve 120) is set to be small, if the outer peripheral surface 112 (outer peripheral surface 112c of the main body member) is pressed radially inward by the front end faces 305a and 306a of the fastening screws 305 and 306, there is a concern that the outer peripheral surface 112 (outer peripheral surface 112c of the main body member) and the inner peripheral surface 111 (inner peripheral surface 111c of the main body member) may elastically deform radially inward. For example, there is a concern that the outer peripheral surface 112c and the inner peripheral surface 111c of the main body member may elastically deform from the pressure applied by the fastening screws 305 and 306. Figure 3 and Figure 4The state shown by the solid line is elastically deformed into the state shown by the dashed line (refer to the attached drawing labels 112c1 and 111c1).

[0081] However, in the tool holder 100 of this embodiment, an extension chamber 123d is formed, which is located on the rear end side of the pressure chamber 123a formed on the rear end side (in Figure 3 The portion of the holding part 124a (located at position H1) communicates with the pressure chamber 123a at its radially outer side and extends axially and circumferentially beyond the rear end of the pressure chamber 123a. That is, the distance along the axial direction of the extension chamber 123d (outer circumferential surface portion 122b) separating the holding part 124a from the outer circumferential surface portion 122a of the sleeve, which is fixed to the inner circumferential surface portion 111c of the main body member. The axial length of the extension chamber 123d (outer circumferential surface portion 122b) is the axial length between the rear end position H1 of the outer circumferential surface portion 122c and the front end position H2 of the outer circumferential surface portion 122a.

[0082] Furthermore, the radial width M1 between the outer peripheral surface portion 122b and the inner peripheral surface portion 121a of the sleeve is set to be larger than the radial width M2 between the outer peripheral surface portions 122c, 122e and the inner peripheral surface portion 121c of the sleeve (holding portions 124a, 124b) (M1 > M2) (see reference). Figure 3 ).

[0083] Due to the presence of the extension chamber 123d communicating with the rear end of the pressurized chamber 123a formed on the rear end side, and the presence of a portion that is radially inward of the extension chamber 123d and thicker than the gripping portion 124a formed on the rear end side, the transmission of force applied to the outer peripheral surface 112 (outer peripheral surface portion 112c of the main body member) to the inner peripheral surface portion 121a of the sleeve can be suppressed. That is, although there is a concern that the force applied to the outer peripheral surface portions 122a and 122b of the sleeve may be transmitted to the inner peripheral surface portion 121a... Figure 3 , Figure 4 The state shown by the solid line is elastically deformed into the state shown by the dashed line (reference numerals 122a1, 122b1), but the elastic deformation of the inner circumferential surface portion 121c of the sleeve (especially the portion corresponding to the rear end of the gripping portion 124a) towards the radially inward side can be suppressed.

[0084] Furthermore, in this embodiment, a stepped inner circumferential surface portion 121b is formed at the junction (rear end of the gripping portion 124a) between the outer circumferential surface portion 122b and the outer circumferential surface portion 122c of the sleeve. That is, the inner circumferential surface portion 121a is formed at a position closer to the rear end of the inner circumferential surface portion 121c formed at the position corresponding to the gripping portion 124a, and this inner circumferential surface portion 121a has an inner diameter D1 that is larger than the inner diameter D2 of the inner circumferential surface portion 121c.

[0085] Therefore, even when the inner circumferential surface portion 121a of the sleeve elastically deforms radially inward along with the elastic deformation of the outer circumferential surface portion 122b of the sleeve, the reduction of the inner diameter of the inner space 120a of the sleeve can be suppressed.

[0086] Therefore, in the tool holder 100 of this embodiment, the inner diameter of the inner space 120a (tool insertion space) of the sleeve can be suppressed due to the force (force borne by the outer peripheral surface of the tool holder) clamping the tool holder 100, and the insertion of the tool 200 (tool shank) into the inner space 120a (tool insertion space) of the sleeve can be prevented from becoming difficult.

[0087] This invention is not limited to the structure described in the embodiments, and various changes, additions, and deletions can be made.

[0088] The structure of the main components and sleeves is not limited to the structure described in the embodiments.

[0089] In one embodiment, the tool holder consists of two components (a main body component and a sleeve), but the tool holder can also consist of one component or more than three components.

[0090] In one embodiment, the holding part is composed of two pressure chambers and two gripping parts, but the holding part may be composed of at least one pressure chamber and at least one gripping part. When the holding part is composed of one pressure chamber and one gripping part, the one pressure chamber corresponds to the "pressure chamber formed on the rear end side of at least one pressure chamber" of the present invention, and the one gripping part corresponds to the "gripping part formed on the rear end side of at least one gripping part" of the present invention.

[0091] In one embodiment, a sleeve inner circumferential surface portion 121a with a larger inner diameter is formed on the rear end side, but the sleeve inner circumferential surface portion 121a can also be omitted.

[0092] The tool holder mounting section is not limited to the tool holder.

[0093] The method of holding the tool holder is not limited to pressing the tool holder radially inward with a fastening screw.

[0094] The method of adjusting the pressure in the pressurization chamber is not limited to adjusting it by the pressurization screw.

[0095] In this embodiment, there is no concern about elastic deformation of the front end of the tool holder, so an extension chamber is formed that communicates with the rear end of the pressure chamber formed on the rear end and extends on the rear end. However, if there is a concern about elastic deformation on the front end, an extension chamber that communicates with the front end of the pressure chamber formed on the front end and extends on the front end can also be formed. In this case, the extension chamber can be formed on the front end using the same method as the method for forming the extension chamber on the rear end.

[0096] Description of Reference Numerals

[0097] 100, 400: Tool holder; 110, 410: Main body component; 110A, 410A: Front end face of main body component; 110a, 410a: Inner space of main body component; 111, 411: Inner circumferential surface of main body component; 111a~111c, 411a~411c: Inner circumferential surface portion of main body component; 112a~112d, 412a~412d: Outer circumferential surface portion of main body component; 113: Flange; 114: Insert Manhole; 115, 415, Screw (compression screw); 116, Insertion hole; 117, 417, Screw (sealing screw); 118, Steel ball; 120, 420, Sleeve; 120A, 420A, Front end face of sleeve; 120B, 420B, Rear end face of sleeve; 120a, 420a, Inner space of sleeve; 121, 421, Inner circumferential surface of sleeve; 121a~121c, 421a, Inner circumferential surface portion of sleeve; 122. 422. Outer circumferential surface of the sleeve; 122a~122f, 422a~422e. Outer circumferential surface portion of the sleeve; 123a, 123b, 423a, 423b. Pressure chamber; 123c, 423c. Connecting passage; 123d. Extension chamber; 124a, 124b, 424a, 424b. Holding part; 125. Groove; 200. Tool; 300. Tool holder (tool retainer mounting part); 300A. Tool holder front end face (tool) 300a, inner space of the tool holder (inner space of the tool holder mounting part); 301, inner circumferential surface of the tool holder (inner circumferential surface of the tool holder mounting part); 302, outer circumferential surface of the tool holder (outer circumferential surface of the tool holder mounting part); 303, 304, holes; 303a, 304a, openings; 305, 306, fastening screws (fastening components); 305a, 306a, front end face of the fastening screws (front end face of the fastening components).

Claims

1. A tool holder, formed as a cylindrical shape extending axially, is clamped in a state where it is inserted into a tool holder insertion space of a tool holder mounting portion, characterized in that, The tool holder has an inner peripheral surface, an outer peripheral surface, a tool insertion space formed by the inner peripheral surface, and a holding portion for holding a tool inserted into the tool insertion space. The retaining portion has: at least one pressure chamber extending along the axial and circumferential directions, and at least one gripping portion formed between the at least one pressure chamber and the inner circumferential surface of the tool retainer and extending along the axial and circumferential directions. The tool holder is configured such that by increasing the pressure in the at least one pressure chamber, the at least one gripping portion can be elastically deformed radially inward. The tool holder comprises a main body and a sleeve. The main component is formed as a cylindrical shape extending along the axial direction, and has an inner circumferential surface, an outer circumferential surface, a front end surface, a rear end surface, and an inner space formed by the inner circumferential surface. The outer peripheral surface of the main component has an axially extending portion and a notch surface formed by cutting an opening in the outer peripheral surface portion of the main component, the notch surface extending axially from the rear end face of the main component. The sleeve is formed as a cylindrical shape extending along the axial direction, and has an inner circumferential surface, an outer circumferential surface, a front end surface, a rear end surface, and an inner space formed by the inner circumferential surface. The outer peripheral surface of the sleeve has: a first sleeve outer peripheral surface portion extending axially and circumferentially at the rear end side, a second sleeve outer peripheral surface portion extending axially and circumferentially at the front end side, a fourth sleeve outer peripheral surface portion extending axially and circumferentially between the first sleeve outer peripheral surface portion and the second sleeve outer peripheral surface portion, and at least one third sleeve outer peripheral surface portion. The fourth sleeve outer peripheral surface portion is connected to the rear end of the third sleeve outer peripheral surface portion formed on the rear end side of the at least one third sleeve outer peripheral surface portion and the front end of the first sleeve outer peripheral surface portion, and is recessed radially inward compared to the first sleeve outer peripheral surface portion and the second sleeve outer peripheral surface portion. The outer peripheral surface portion of at least one of the third sleeves is concave radially inward compared to the outer peripheral surface portion of the fourth sleeve. The inner circumferential surface of the sleeve has a portion with a second inner diameter at a position closer to the front end than the portion corresponding to the junction between the third and fourth outer circumferential surfaces formed at the rear end. It also has a portion with a first inner diameter larger than the second inner diameter at a position closer to the rear end than the portion corresponding to the junction. Furthermore, at the position corresponding to the junction, there is a stepped inner circumferential surface portion connecting the portion with the second inner diameter and the portion with the first inner diameter. With the sleeve inserted into the inner space of the main body component, the outer peripheral surfaces of the first sleeve and the second sleeve are fixed to the inner peripheral surface of the main body component. The inner circumferential surface of the tool holder is formed by the inner circumferential surface of the main body component and the inner circumferential surface of the sleeve, and the inner circumferential surface of the tool holder forms the tool insertion space. The outer peripheral surface of the tool holder is formed by the outer peripheral surface of the main component. The at least one pressure chamber is formed by the at least one third sleeve outer peripheral surface portion and the inner peripheral surface of the main body component. The at least one gripping portion is formed by the at least one third sleeve outer peripheral surface portion and the sleeve inner peripheral surface. An extension chamber is formed by the outer peripheral surface portion of the fourth sleeve and the inner peripheral surface of the main body member. This extension chamber communicates with the rear end of the pressure chamber formed on the rear end side of the at least one pressure chamber, and extends along both the axial and circumferential directions. The radial width of the extension chamber is set to be smaller than the radial width of the pressure chamber formed on the rear end side, and the radial width between the extension chamber and the inner circumferential surface of the tool holder is set to be larger than the radial width between the pressure chamber formed on the rear end side and the inner circumferential surface of the tool holder. The tool holder is configured to suppress the radially inward elastic deformation of the portion of the inner peripheral surface of the tool holder corresponding to the grip portion formed on the rear end side of the at least one grip portion caused by the force borne by the notch surface of the outer peripheral surface of the tool holder when the tool holder is inserted into the tool holder insertion space of the tool holder mounting portion.

Images