HK40011884B - Tool holder - Google Patents

Description

knife handle

Technical Field

The present invention relates to a tool holder for holding a cutting tool, and more particularly to a tool holder capable of properly holding a tap for tapping.

Background Technology

When tapping a workpiece (the component being machined) to form an internal thread hole, the tap is held in the tool holder (called the "tap shank") mounted on the machine tool spindle. During tapping, excessive stress may occur at the tap tip due to cutting resistance or other factors. When excessive stress occurs at the tap tip, the machining accuracy of the internal thread hole may decrease.

Therefore, a tool holder with a stress-absorbing mechanism has been proposed, which absorbs stress acting on the tip of a tap. Tool holders with stress-absorbing mechanisms are disclosed, for example, in Patent Document 1 and Patent Document 2. The tool holder disclosed in Patent Document 1 has: a first stress-absorbing mechanism for absorbing stress acting on the axial side of the tool grip; and a second stress-absorbing mechanism for absorbing stress acting on the other axial side of the tool grip. Furthermore, the tool holder disclosed in Patent Document 2 has a stress-absorbing mechanism configured to absorb stress acting on both the axial side and the other axial side of the tool grip using this single stress-absorbing mechanism.

Existing technical documents

Patent documents

Patent Document 1: Japanese Patent Application Publication No. 2012-11474

Patent Document 2: Japanese Patent Application Publication No. 2002-46020

Summary of the Invention

The problem the invention aims to solve

The tool holder disclosed in Patent Document 1 is configured to absorb stress acting on the tool handle on one axial direction and the other axial direction using a first stress-absorbing mechanism and a second stress-absorbing mechanism, respectively. Furthermore, the tool holder disclosed in Patent Document 2 is configured to absorb stress acting on the tool handle on one axial direction and the other axial direction using a single stress-absorbing mechanism. Therefore, the structure is complex.

The present invention is made in view of the fact that its purpose is to provide a tool holder that can absorb stress acting on a tool through a simple structure.

Solution for solving the problem

The tool holder of the present invention includes a main body having an inner circumferential surface and an outer circumferential surface. The main body has a shank at its rear end and a tool holding portion at its top end. The shank is held by a holding mechanism provided on the spindle of a machine tool. Typically, the portion of the outer circumferential surface of the main body corresponding to the shank is held by the holding mechanism of the machine tool. The tool holding portion is used to hold a tool. Typically, the outer circumferential surface of the tool shank, into an inner space portion (tool insertion space) of the main body, is held by the inner circumferential surface portion of the main body, which is formed by the inner circumferential surface portion of the main body corresponding to the tool holding portion.

Furthermore, the main body has a first elastic portion between the shank and the tool holder. This first elastic portion has multiple first gaps and multiple second gaps that connect the inner circumferential surface of the main body (the portion of the inner circumferential surface of the main body corresponding to the first elastic portion) and the outer circumferential surface of the main body (the portion of the outer circumferential surface of the main body corresponding to the first elastic portion). The first elastic portion is configured to be elastically deformable along both the axial and circumferential directions. The description "capable of elastically deforming along both the axial and circumferential directions" indicates the characteristic of being able to elastically deform along both the axial and circumferential directions to absorb the axial and circumferential stresses acting on the tool holder during machining with a tool.

The first gap extends circumferentially (including "along substantially circumferentially") in such a way that at least a portion overlaps with at least one other first gap in the circumferential direction. And the second gap extends axially (including "along substantially axially") in such a way that at least a portion overlaps with at least one other second gap in the axial direction.

The number, shape (width, cross-section, length), and placement of the first and second gaps can be varied within the range of elastic deformation of the first elastic part along the axial and circumferential directions.

In this invention, the stress acting on the tool holder during machining can be absorbed through a simple structure.

In different technical solutions of the present invention, at least one first gap and at least one second gap are continuous.

In this technical solution, a first gap and a second gap can be easily formed that connect the inner peripheral surface of the main body (the portion of the inner peripheral surface of the main body corresponding to the first elastic part) and the outer peripheral surface of the main body (the portion of the outer peripheral surface of the main body corresponding to the first elastic part). In particular, when the gap is formed using a wire cutting process, multiple gaps can be easily formed in a short time.

In different technical solutions of the present invention, a plurality of first gaps and a plurality of second gaps are divided into a plurality of gap groups comprising the first gaps and the second gaps. The number of first gaps and the number of second gaps included in a gap group are preferably set to be equal, but may also be different. A gap group is configured such that at least a portion overlaps with at least one other gap group in the circumferential and axial directions. Preferably, the plurality of gap groups are arranged circumferentially.

In this technical solution, the first elastic part can be formed more easily.

In different technical solutions of the present invention, multiple gap groups include a first gap group and a second gap group, wherein the first gap group and the second gap group include the same number of first gaps and the same number of second gaps, but the configuration shape of the first gaps and second gaps in the first gap group is different from the configuration shape of the first gaps and second gaps in the second gap group. The first gap group and the second gap group are arranged alternately along the circumferential direction.

Preferably, the first and second voids included in the first void group and the first and second voids included in the second void group are formed continuously.

Furthermore, the configuration shapes of the first and second gaps included in the first gap group are preferably set to be point-symmetric with the configuration shapes of the first and second gaps included in the second gap group.

In this technical solution, the first elastic part can be formed more easily.

In another embodiment of the present invention, a first cylindrical member capable of moving axially in conjunction with the elastic deformation of the first elastic portion is disposed on the outer periphery of the main body. For example, a first cylindrical member capable of moving axially is disposed on the outer periphery of the first elastic portion, and a pin is disposed between a hole formed in the first cylindrical member and a hole formed in the main body at a position closer to the top end of the first elastic portion.

Furthermore, a second elastic portion is provided at the rear end of the first cylindrical member, capable of elastically deforming in conjunction with the axial movement of the first cylindrical member. For example, a stepped surface is formed on the outer peripheral surface of the main body at a position further rear-end than the first elastic portion, and the second elastic portion is provided between the stepped surface of the outer peripheral surface of the main body and the end face of the rear end of the first cylindrical member. An O-ring, for example, can be used as the second elastic portion.

In this technical solution, the elastic characteristics of the first elastic part when it deforms axially toward the rear end (contraction elastic characteristics) can be set to be stronger than the elastic characteristics of the first elastic part when it deforms axially toward the top end (elongation elastic characteristics) by utilizing the elastic characteristics of the second elastic part. Therefore, for example, the stress generated by the difference between the tap pitch and the machine feed (feed error) can be absorbed using the weaker elongation elastic characteristics. However, if the elongation elastic characteristics are strong, thread wear may occur when absorbing feed error. On the other hand, the stress generated when the tap tip cuts into the workpiece can be absorbed using the stronger contraction elastic characteristics. However, if the contraction elastic characteristics are weak, the machining depth may be shallower when the tap tip cuts into the workpiece.

In another embodiment of the present invention, a second cylindrical member capable of moving axially in conjunction with the axial movement of the tool (rear end of the tool) held by the tool holder is disposed on the inner circumferential side of the main body. For example, a position adjustment member capable of abutting against the end face of the rear end of the tool held by the tool holder and a second cylindrical member threadedly connected to the position adjustment member are disposed on the inner circumferential side of the main body in a manner capable of axial movement.

Furthermore, a third elastic portion is provided at the rear end of the second cylindrical member, capable of elastically deforming in conjunction with the axial movement of the second cylindrical member. For example, a stepped surface is formed on the inner circumferential surface of the main body at a position further rear-end than the first elastic portion, and the third elastic portion is provided between the stepped surface of the inner circumferential surface of the main body and the end face of the rear end of the second cylindrical member. An O-ring, for example, can be used as the third elastic portion.

In this technical solution, the elastic characteristics of the first elastic part when it deforms axially toward the rear end (contraction elastic characteristics) can be set to be stronger than the elastic characteristics of the first elastic part when it deforms axially toward the top end (elongation elastic characteristics) by utilizing the elastic characteristics of the third elastic part. Therefore, for example, the stress generated by the difference between the tap pitch and the machine feed (feed error) can be absorbed using the weaker elongation elastic characteristics. On the other hand, the stress generated when the tap tip cuts into the workpiece can be absorbed using the stronger contraction elastic characteristics.

The effects of the invention

In the case of the tool holder of the present invention, the stress acting on the tool during machining can be absorbed through a simple structure.

Attached Figure Description

Figure 1 is a cross-sectional view of the first embodiment of the knife handle of the present invention.

Figure 2 is an enlarged view of the portion indicated by arrow II in Figure 1.

Figure 3 is a diagram showing the elastic part of the handle in the first embodiment.

Figure 4 is the view seen from the direction of arrow IV in Figure 3.

Figure 5 is a diagram showing the elastic part of the handle in the second embodiment.

Figure 6 is a diagram showing the elastic part of the handle in the third embodiment.

Detailed Implementation

The following detailed description is only intended to provide those skilled in the art with information on preferred applications for carrying out the invention. The technical scope of the invention is not limited by the detailed description, but is determined based on the description in the claims. Therefore, the combinations of structures and methods in the following detailed description are not, in a broad sense, all necessary for carrying out the invention, but are only used to disclose representative forms of the invention in the detailed description together with the reference numerals in the drawings.

Hereinafter, embodiments of the knife handle of the present invention will be described with reference to the accompanying drawings.

In this specification, the direction of extension of the rotation center line P of the main body of the tool holder (direction A shown in FIG1) is referred to as the "axial direction". Furthermore, in a section perpendicular to the axial direction, the direction along the arc centered on the rotation center (rotation center line P) of the main body is referred to as the "rotation direction" or "circumferential direction", and the direction of the line passing through the rotation center of the main body is referred to as the "radial direction". Additionally, the side where the tool is inserted along the axial direction (the right side in FIG1) is referred to as the "top side", and the side opposite to the side where the tool is inserted (the left side in FIG1) is referred to as the "rear side".

The first embodiment 100 of the tool holder of the present invention will be described with reference to FIGS. 1 and 2. The tool holder 100 of the first embodiment is configured as a tap shank for holding a tap used for tapping a workpiece to form an internal thread hole. FIG. 1 is a cross-sectional view of the tool holder 100 of the first embodiment, and FIG. 2 is an enlarged view of the portion indicated by arrow II in FIG. 1.

The knife handle 100 of this embodiment includes a main body 200. In this embodiment, the main body 200 is made of steel.

The main body 200 is formed into a cylindrical shape having an inner circumferential surface 240 and an outer circumferential surface 250.

The inner circumferential surface 240 of the main body has a first inner circumferential surface portion 241 to a fifth inner circumferential surface portion 245. Among them, the third inner circumferential surface portion 243 of the main body is formed as a stepped surface that connects the second inner circumferential surface portion 242 and the fourth inner circumferential surface portion 244 of the main body with different inner diameters.

The outer peripheral surface 250 of the main body has a first outer peripheral surface portion 251 to a sixth outer peripheral surface portion 256. Among them, the third outer peripheral surface portion 253 is formed as a stepped surface connecting the second outer peripheral surface portion 252 and the fourth outer peripheral surface portion 254 of the main body with different outer diameters, and the fifth outer peripheral surface portion 255 is formed as a stepped surface connecting the fourth outer peripheral surface portion 254 and the sixth outer peripheral surface portion 256 of the main body with different outer diameters.

Furthermore, an inner space 260 is formed by the inner circumferential surface 240 of the main body. A cooling medium (e.g., cooling oil) for cooling the tool 10 held by the tool holder 220 flows within the inner space 260. The inner space 260 has a first inner space portion 261 formed by the first inner circumferential surface portion 241 of the main body, a second inner space portion 262 formed by the second inner circumferential surface portion 242 of the main body, and a third inner space portion 263 formed by the third inner circumferential surface portions 243 to the fourth inner circumferential surface portions 245 of the main body. The third inner space portion 263 forms a tool insertion space for inserting the holding portion 11 of the tap 10.

The main body 200 has a handle 210 on the rear end side and a tool holding part 220 on the top end side, and an elastic part 230 between the handle 210 and the tool holding part 220.

Furthermore, it includes a tool holding mechanism 300, which holds the tool 10 (hereinafter referred to as "taper 10") by cooperating with the tool holding part 220 of the main body 200.

Furthermore, it includes a stress-absorbing mechanism 400, which includes an elastic portion 230 of the main body 200 for absorbing the stress (axial stress and rotational stress) acting on the tip of the tap 10 during tapping, i.e., the stress (axial stress and rotational stress) acting on the tool holding portion 220 that holds the tap 10.

The elastic portion 230 corresponds to the "first elastic portion" of the present invention.

The outer peripheral surface portion of the main body (first main body outer peripheral surface portion 251) corresponding to the handle portion 210 is formed in a conical shape. The handle portion 210 is connected to the spindle of the machine tool by holding the first main body outer peripheral surface portion 251 using a holding mechanism provided on the spindle of the machine tool. Various known holding mechanisms can be used as the holding mechanism for holding the first main body outer peripheral surface portion 251 (handle portion 210).

The tool holding part 220 holds the tap 10 by cooperating with the tool holding mechanism 300.

A spiral blade is formed on the tip side of the tap 10 with a predetermined pitch. Furthermore, a retaining portion 11 with a retaining surface 12 on the outer peripheral side is provided on the rear end side of the tap 10.

The tool holding mechanism 300 includes a collet 310, a locking component 320, and a fastening tool 330.

The collet 310 is inserted into the inner space 263 of the third main body, formed by the inner circumferential surface portion of the main body (the fifth main body inner circumferential surface portion 245) corresponding to the tool holder 220. The fifth main body inner circumferential surface portion 245 and the outer circumferential surface 312 of the collet have conical surfaces that can engage with each other. An engaging member 320 is disposed on the outer periphery of the top end side of the collet 310. Furthermore, the top end side of the fastening tool 330 is disposed on the outer periphery of the engaging member 320, and the rear end side of the fastening tool 330 is threadedly engaged with the outer circumferential surface portion of the main body (the sixth main body outer circumferential surface portion 256) corresponding to the tool holder 220. The retaining portion 11 of the tap 10 passes through a hole formed in the collet 310.

When the fastening tool 330 is rotated in this state, the fastening tool 330, the engaging member 320, and the collet 310 move along the front-rear direction (axial direction). When the collet 310 moves towards the rear end, the retaining surface 12 of the retaining portion 11 of the tap 10 is held by the engagement of the tapered surface formed on the inner circumferential surface portion 245 of the fifth main body with the tapered surface formed on the outer circumferential surface 312 of the collet 310. That is, the tap 10 is held by the tool holding portion 220. On the other hand, when the collet 310 moves towards the top end, the holding of the tap 10 is released.

The elastic part 230 is configured to be elastically deformable along the circumferential and axial directions, and is used to absorb the circumferential stress and axial stress acting on the tip of the tap 10 when tapping is performed using the tap 10.

The elastic portion 230 of this embodiment will be described with reference to Figures 3 and 4. Figure 3 is a view of the elastic portion 230 from the outer peripheral side, and Figure 4 is a view from the direction of arrow IV in Figure 3.

The elastic portion 230 has multiple gaps that connect the inner peripheral surface portion (4th inner peripheral surface portion 244) of the main body portion and the outer peripheral surface portion (4th outer peripheral surface portion 254) of the main body portion corresponding to the elastic portion 230.

In this embodiment, the plurality of gaps formed in the elastic portion 230 include a plurality of first gaps extending in the circumferential direction and a plurality of second gaps extending in the axial direction. The "first gaps extending in the circumferential direction" include gaps extending in a generally circumferential direction, and the "second gaps extending in the axial direction" include gaps extending in a generally axial direction.

The first gap extending circumferentially is configured such that at least a portion overlaps with at least one other first gap circumferentially. Furthermore, the second gap extending axially is configured such that at least a portion overlaps with at least one other second gap axially.

Furthermore, the multiple first gaps and multiple second gaps are divided into multiple gap groups including the first gaps and the second gaps.

In this embodiment, the gaps are divided into a first gap group 231 and a second gap group 234. The first gap group 231 includes first gaps 232a-232c extending circumferentially and second gaps 233a-233d extending axially. The second gap group 234 includes first gaps 235a-235c extending circumferentially and second gaps 236a-236d extending axially. Furthermore, in this embodiment, the gaps are divided into two first gap groups 231 and two second gap groups 234.

The gap between the inner circumferential surface 240 (the fourth inner circumferential surface portion 244) of the main body and the outer circumferential surface 250 (the fourth outer circumferential surface portion 254) of the main body is formed, for example, using a wire cutting process. When forming the gap using a wire cutting process, a starting hole needs to be formed. That is, in order to form multiple gaps independently using a wire cutting process, a starting hole needs to be formed for each gap.

Preferably, at least one first gap and at least one second gap are configured to be continuous, so that when the first gap and the second gap are formed using a wire cutting process, the processing operation can be easily performed in a short time.

In this embodiment, the first gaps 232a to 232c and the second gaps 233a to 233d included in the first gap group 231 are configured to be continuous.

Specifically, the second gap 233a extends axially toward the top end from the end of the first gap 232a on one circumferential side (the upper side in FIG. 3), which extends circumferentially. The second gap 233b extends axially toward the top end from the end of the first gap 232a on the other circumferential side (the lower side in FIG. 3). Furthermore, the first gap 232b extends circumferentially toward the other circumferential side from the end of the second gap 233a on the top side. The second gap 233c extends axially toward the rear end from the end of the first gap 232b on the other circumferential side. Furthermore, the first gap 232c extends circumferentially toward one circumferential side from the end of the second gap 233b after the top end. The second gap 233d extends axially toward the rear end from the end of the first gap 232c on one circumferential side. In addition, in this embodiment, the first gaps 232a to 232c and the second gaps 233a and 233b have straight lines, the second gap 233c has a curved shape (e.g., arc shape) that protrudes to the other side in the circumferential direction, and the second gap 233d has a curved shape (e.g., arc shape) that protrudes to one side in the circumferential direction.

Similarly, the first gaps 235a to 235c and the second gaps 236a to 236d included in the second gap group 234 are arranged to be continuous.

Specifically, the second gap 236a extends axially toward the rear end from the end of the first gap 235a on one circumferential side (the upper side in FIG. 4), which extends circumferentially. The second gap 236b extends axially toward the rear end from the end of the first gap 235a on the other circumferential side (the lower side in FIG. 4). Furthermore, the first gap 235b extends circumferentially toward the other circumferential side from the end of the second gap 236a on the rear end side. The second gap 236c extends axially toward the top end from the end of the first gap 235b on the other circumferential side. Furthermore, the first gap 235c extends circumferentially toward one circumferential side from the end of the second gap 236b on the rear end side. The second gap 236d extends axially toward the top end from the end of the first gap 235c on one circumferential side. In addition, in this embodiment, the first gaps 235a to 235c and the second gaps 236a and 236b have a straight shape, the second gap 236c has a curved shape (e.g., arc shape) that protrudes to the other side in the circumferential direction, and the second gap 236d has a curved shape (e.g., arc shape) that protrudes to one side in the circumferential direction.

In this embodiment, the circumferential arrangement of the first gaps 232a-232c and the second gaps 233a-233d included in the first gap group 231 is set to be point-symmetric with the circumferential arrangement of the first gaps 235a-235c and the second gaps 236a-236d included in the second gap group 234. That is, the arrangement of the gaps included in the first gap group 231 and the arrangement of the gaps included in the second gap group 234 are set such that when one is rotated 180 degrees, it is consistent with the other.

The gap groups (first gap group 231, second gap group 234) are configured such that at least a portion overlaps with at least one other gap group along the circumferential and axial directions.

In this embodiment, the first gap group 231 and the second gap group 234 are arranged alternately along the circumferential direction, and the first gap group 231 and the second gap group 234 that are adjacent in the circumferential direction are arranged to partially overlap in the circumferential and axial directions.

Specifically, the configuration is as follows: the second gap 233c included in the first gap group 231 is disposed between the second gaps 236b and 236d included in the second gap group 234 which are adjacent to the second gap 233c on one side of the circumference, and the second gap 233d included in the first gap group 231 is disposed between the second gaps 236a and 236c included in the second gap group 234 which are adjacent to the second gap 233d on the other side of the circumference. Alternatively, the configuration may be as follows: the second gap 236c included in the second gap group 234 is disposed between the second gaps 233b and 233d included in the first gap group 231 that are adjacent to the second gap 236c on one side of the circumference, and the second gap 236d included in the second gap group 234 is disposed between the second gaps 233a and 233c included in the first gap group 231 that are adjacent to the second gap 236d on the other side of the circumference.

If axial stress or rotational stress acts on the tap 10 during tapping to form an internal thread hole in a workpiece, then axial stress or rotational stress also acts on the tool holder 220. This stress also acts on the elastic portion 230 connected to the tool holder 220. For example, stress acts in the axial direction from the tip side towards the rear side, or in the rotational direction opposite to the rotational direction of the tap 10.

In this embodiment, the elastic portion 230 is configured to be elastically deformable along the axial and circumferential directions.

Therefore, for example, when stress is applied to the elastic portion 230 along the axial direction A2, the elastic portion 230 elastically deforms (contracts) in the axial direction A2. As a result, the stress along the axial direction A2 is absorbed. When the stress along the axial direction A2 decreases, the elastically deformed elastic portion 230 returns to its original shape (elongates).

Furthermore, when circumferential stress is applied to the elastic portion 230 via the tool holder 220, the elastic portion 230 elastically deforms along the circumferential direction. Thus, the circumferential stress is absorbed. When the circumferential stress decreases, the elastically deformed elastic portion 230 returns to its original shape.

Furthermore, when stress in the axial direction A2 and stress in the circumferential direction are applied to the elastic part 230, the elastic part 230 elastically deforms in the axial direction A2 and elastically deforms in the circumferential direction (exhibiting torsional elastic deformation). Thus, the stress in the axial direction A2 and the stress in the circumferential direction are absorbed. As the stress in the axial direction A2 and the stress in the circumferential direction decrease, the elastically deformed elastic part 230 returns to its original shape.

During tapping, stresses generated by the difference between the tap pitch and the machine feed (called "feed error") and stresses generated by the tap tip cutting into the workpiece are applied to the tap. The stresses generated by the feed error can be absorbed by the elastic deformation of the elastic part 230 through elongation, and the stresses generated by the tap tip cutting into the workpiece can be absorbed by the elastic deformation of the elastic part 230 through contraction.

Here, when utilizing the elongation elasticity of the elastic portion 230 to absorb stress caused by feed error, if the elongation elasticity of the elastic portion 230 is too strong, thread wear may occur. Therefore, it is preferable to set the elongation elasticity of the elastic portion 230 to be relatively weak. On the other hand, when utilizing the contraction elasticity of the elastic portion 230 to absorb stress caused by the tap tip cutting into the workpiece, if the contraction elasticity of the elastic portion 230 is weak, the machining depth may be relatively shallow. Therefore, it is preferable to set the contraction elasticity of the elastic portion 230 to be relatively strong.

If there is only the elastic part 230, it is not possible to set a stronger contraction elasticity and a weaker elongation elasticity.

Therefore, in this embodiment, a stress absorbing mechanism 400 is included. This stress absorbing mechanism 400 uses an elastic part 230 that can absorb axial and circumferential stress through a simple construction, and can be set with elongation elastic characteristics suitable for absorbing stress caused by feed error and contraction elastic characteristics suitable for absorbing stress caused by the tap tip cutting into the workpiece.

The stress absorption mechanism 400 of this embodiment includes an elastic part 230, a collar 410 for adjusting the elastic properties of the elastic part 230, a support member 420, a position adjustment member 430, and O-rings 461 and 462.

Furthermore, the inner circumferential surface portion of the main body (the fourth inner circumferential surface portion 244) and the outer circumferential surface portion of the main body (the fourth outer circumferential surface portion 254) corresponding to the elastic portion 230, and the outer circumferential surface portion of the main body (the sixth outer circumferential surface portion 256) corresponding to the tool holder portion 220, when viewed in a cross section perpendicular to the axial direction, have a circular shape with the rotation center as the center point.

Furthermore, the main body 200 has a hole 272 formed by the hole wall surface 271 and open to the outer peripheral surface portion 254 of the fourth main body at a position closer to the top end of the elastic part 230, and a connecting hole 274 formed by the hole wall surface 273 at a position closer to the rear end of the elastic part 230.

The collar 410 is formed as a cylinder having an inner circumferential surface 411 and an outer circumferential surface 412. When viewed in a section perpendicular to the axial direction, the inner circumferential surface 411 and the outer circumferential surface 412 have a circular shape centered on the center of rotation. Furthermore, the collar 410 has a connecting hole 416 formed by a hole wall surface 415 on its top end side and a connecting hole 418 formed by a hole wall surface 417 on its rear end side.

A collar 410 is disposed on the outer peripheral side of the fourth main body portion 254. A pin 441 is inserted into the connecting hole 416 of the collar 410 and the hole 272 of the main body portion 200. Thus, the collar 410 is connected to the main body portion 200 by the pin 441 at a position closer to the top end of the elastic portion 230. That is, when the elastic portion 230 elastically deforms along the axial direction (in conjunction with the elastic deformation of the elastic portion 230 along the axial direction), the collar 410 can move along the outer peripheral surface portion 254 of the fourth main body portion (along the axial direction).

Furthermore, if the inner diameter of the connecting hole 416 is set to be larger than the outer diameter of the pin 441, the timing of the movement of the collar 410 and the elastic part 230 along the axial direction in conjunction with their elastic deformation along the axial direction can be delayed accordingly to the difference between the inner diameter of the connecting hole 416 and the outer diameter of the pin 441. Of course, it is also possible to configure the collar 410 and the elastic part 230 to move along the axial direction immediately in conjunction with their elastic deformation along the axial direction.

In addition, an O-ring 461 is disposed between the outer peripheral surface (step surface) 253 of the third main body and the end face 413 on the rear end side of the collar 410. The O-ring 461 is formed of rubber or the like so that it can elastically deform at least along the axial direction.

Additionally, a cover 450 is disposed on the outer periphery of the collar 410. The cover 450 is formed as a bottomed cylindrical shape having a cylindrical portion 451 and a bottom 452. A hole is formed in the center of the bottom 452 using a hole wall surface 453. The cover 450 is mounted to the main body 200 by threading together the hole wall surface 453 and the outer peripheral surface portion 256 of the sixth main body.

The collar 410 corresponds to the "first cylindrical member" of the present invention. Furthermore, the O-ring 461 corresponds to the "second elastic part" of the present invention.

The support member 420 is formed as a cylinder having an inner circumferential surface 421 and an outer circumferential surface 422. When viewed in a cross-section perpendicular to the axial direction, the inner circumferential surface 421 and the outer circumferential surface 422 have a circular shape centered at the rotation center. Furthermore, the support member 420 has a hole 426 at its rear end, formed by a hole wall surface 425 and opening towards the outer circumferential surface 422.

The support member 420 is disposed on the inner circumferential side of the inner circumferential surface portion 244 of the fourth main body (the inner space portion 263 of the third main body formed by the inner circumferential surface portion 244 of the fourth main body). The pin 442 is inserted into the communicating hole 418 of the collar 410, the communicating hole 274 of the main body 200, and the hole 426 of the support member 420. Here, the inner diameter of the hole 426 of the support member 420 is set to be larger than the outer diameter of the pin 442. Therefore, the support member 420 can move relative to the pin 442 within the range of the difference between the inner diameter of the hole 426 and the outer diameter of the pin 442. When the hole wall surface 425 forming the hole 426 abuts against the pin 442, the movement of the support member 420 (axial movement and circumferential movement) is prevented.

In addition, the connecting hole 418 of the collar 410 is configured such that the axial movement of the collar 410 is not hindered by the contact between the hole wall surface 417 forming the connecting hole 418 and the outer peripheral surface of the pin 442.

In addition, an O-ring 462 is disposed between the inner peripheral surface portion (step surface) 243 of the third main body and the end face 423 on the rear end side of the support member 420. The O-ring 462 is formed of rubber or the like so that it can elastically deform at least along the axial direction.

In addition, an O-ring 463 is provided between the outer peripheral surface 244 of the fourth main body and the outer peripheral surface 422 of the support member.

In addition, O-ring 462 is also disposed between the outer peripheral surface portion 244 of the fourth main body and the outer peripheral surface 422 of the support member. O-rings 462 and 463 are used to prevent the cooling medium flowing in the inner space 260 of the main body from flowing out through the gap formed in the elastic portion 230 and the connecting hole formed in the collar 410.

The position adjustment member 430 is formed as a cylinder having an inner peripheral surface 431 and an outer peripheral surface 432. The inner peripheral surface 431 of the position adjustment member forms an inner space for the flow of cooling medium.

The position adjusting member 430 is mounted on the inner circumferential side of the inner circumferential surface 421 of the support member by threading together the threads formed on the inner circumferential surface 432 of the position adjusting member. By rotating the position adjusting member 430, the threaded engagement position is adjusted, thereby adjusting the axial position of the position adjusting member 430 relative to the support member 420. By adjusting the axial position of the position adjusting member 430 relative to the support member 420, the contact position between the rear end face 13 of the tap 10 held by the tool holder 220 and the top end face 434 of the position adjusting member 430, i.e., the axial position (protrusion length) of the tap 10, can be adjusted.

Therefore, when the end face 434 on the top side of the position adjustment member 430 abuts against the end face 13 on the rear side of the tap 10, and the tap 10 moves axially due to the stress acting on the tap 10 (in conjunction with the axial movement of the end face 13 on the rear side of the tap 10), the position adjustment member 430 and the support member 420 move axially.

Furthermore, when the end face 434 on the top side of the position adjusting member 430 and the end face 13 on the rear side of the tap 10 are set to not abut against each other, even if the tap 10 moves axially, the position adjusting member 430 and the support member 420 will not move axially. That is, the function of adjusting the elastic characteristics of the elastic part 230 by means of the O-ring seal 462, which will be described later, is disabled.

The position adjustment member 430 corresponds to the "position adjustment member capable of adjusting the position of the tool along the axial direction" of the present invention. Furthermore, the support member 420 corresponds to the "second cylindrical member" of the present invention. And the O-ring seal 462 corresponds to the "third elastic part" of the present invention.

Next, the operation of the tool holder 100 in this embodiment will be explained. Hereinafter, the case where the end face 434 on the top side of the position adjustment member 430 abuts against the end face 13 on the rear side of the tap 10 (the position adjustment member 430 is used to adjust the position of the tap 10 along the axial direction).

While the tap 10 is held in place by the tool holding part 220 holding the holding part 11 of the tap 10, the tap 10 is rotated.

If axial or rotational stresses act on the tap 10 during tapping to form an internal thread hole, then axial or rotational stresses also act on the tool holder 220. This stress also acts on the elastic portion 230 of the stress-absorbing mechanism 400, which is connected to the tool holder 220. Consequently, the elastic portion 230 elastically deforms along the axial or circumferential direction.

Here, when the elastic part 230 elastically deforms along the axial direction toward the rear end (contraction direction), the collar 410, which is connected to the main body 200 by means of the pin 441, moves along the axial direction toward the rear end immediately or with a slight delay in conjunction with the elastic deformation in the contraction direction.

As the collar 410 moves axially toward the rear end, the O-ring 461 disposed on the rear end of the collar 410 elastically deforms axially toward the rear end.

The O-ring 461 elastically deforms axially toward the rear end, thereby suppressing the movement of the collar 410 axially toward the rear end, and consequently suppressing the elastic deformation of the elastic portion 230 axially toward the rear end (contraction direction). That is, the elastic characteristics of the elastic portion 230 in contraction are substantially set to be stronger due to the elastic characteristics of the O-ring 461.

On the other hand, when the elastic portion 230 elastically deforms along the axial direction toward the top end, there is almost no effect from the elastic deformation of the O-ring 461. That is, the elongation elastic characteristics of the elastic portion 230 remain unchanged.

Furthermore, when the tap 10 (end face 13 on the rear end side of the tap 10) moves axially toward the rear end side due to the elastic deformation of the elastic part 230 along the axial direction toward the rear end side, the position adjustment member 430 and the support member 420 threadedly connected to the position adjustment member 430 also move axially toward the rear end side. That is, the position adjustment member 430 and the support member 420 move axially toward the rear end side in conjunction with the movement of the tap 10 (tool) along the axial direction toward the rear end side.

As the support member 420 moves axially toward the rear end, the O-ring 462 elastically deforms axially toward the rear end.

The O-ring 462 elastically deforms axially toward the rear end, thereby suppressing the movement of the support member 420 and the position adjustment member 430 axially toward the rear end, and consequently suppressing the elastic deformation of the elastic portion 230 axially toward the rear end (contraction direction). That is, the elastic characteristics of the contraction of the elastic portion 230 are substantially set to be stronger due to the elastic characteristics of the O-ring 462.

On the other hand, when the elastic portion 230 elastically deforms along the axial direction toward the top end, there is almost no effect from the elastic deformation of the O-ring 462. That is, the elongation elastic characteristics of the elastic portion 230 remain unchanged.

Furthermore, when the end face 434 on the top side of the position adjustment member 430 does not abut against the end face 13 on the rear side of the tap 10, the function of adjusting the elastic properties of the elastic part 230 by means of the O-ring seal 462 does not work.

Next, the elastic portion 230 of the handle in the second embodiment will be described with reference to FIG5.

In this embodiment, the elastic portion 230 is divided into a first gap group 231 and a second gap group 234. The first gap group 231 includes first gaps 232a-232e extending circumferentially and second gaps 233a-233d extending axially. The second gap group 234 includes first gaps 235a-235e extending circumferentially and second gaps 236a-236d extending axially. Furthermore, similar to the first embodiment, it is divided into two first gap groups 231 and two second gap groups 234.

Furthermore, the first gaps 232a to 232e and the second gaps 233a to 233d included in the first gap group 231 are arranged to be continuous.

Specifically, the second gap 233a extends axially toward the top end from the end of the first gap 232a on one circumferential side (the upper side in FIG. 5), which extends circumferentially. The second gap 233b extends axially toward the top end from the end of the first gap 232a on the other circumferential side (the lower side in FIG. 5). Furthermore, the first gap 232b extends circumferentially toward the other circumferential side from the end of the second gap 233a on the top side. The second gap 233c extends axially toward the rear end from the end of the first gap 232b on the other circumferential side. The first gap 232d extends circumferentially toward one circumferential side from the end of the second gap 233c on the rear end side. Furthermore, the first gap 232c extends circumferentially to one side from the end of the second gap 233b after the top of the second gap 233b, the second gap 233d extends axially to the rear end from the end of the first gap 232c on one side of the circumferential direction, and the first gap 232e extends circumferentially to the other side from the end of the second gap 233d on the rear end side of the circumferential direction.

Similarly, the first gaps 235a to 235e and the second gaps 236a to 236d included in the second gap group 234 are arranged to be continuous.

Specifically, the second gap 236a extends axially toward the rear end from one circumferential end of the first gap 235a, which extends circumferentially, and the second gap 236b extends axially toward the rear end from the other circumferential end of the first gap 235a. Furthermore, the first gap 235b extends circumferentially toward the other circumferential side from the rear end of the second gap 236a, the second gap 236c extends axially toward the top end from the other circumferential end of the first gap 235b, and the first gap 235d extends circumferentially toward one circumferential side from the top end of the second gap 236c. Furthermore, the first gap 235c extends circumferentially toward one side from the rear end of the second gap 236b, the second gap 236d extends axially toward the top side from the end of the first gap 235c on one side, and the first gap 235e extends circumferentially toward the other side from the end of the second gap 236d on the top side.

In addition, in this embodiment, the first gaps 232a-232e, 235a-235e and the second gaps 233a-233d, 236a-236d have a straight shape.

Furthermore, the circumferential configuration of the first gaps 232a-232e and the second gaps 233a-233d included in the first gap group 231 is set to be point-symmetric with the circumferential configuration of the first gaps 235a-235e and the second gaps 236a-236d included in the second gap group 234.

Furthermore, the void group is configured such that at least a portion overlaps with at least one other void group along the circumferential and axial directions.

In this embodiment, the first gap group 231 and the second gap group 234 are arranged alternately along the circumferential direction, and the first gap group 231 and the second gap group 234 that are adjacent in the circumferential direction are arranged to partially overlap in the circumferential and axial directions.

Specifically, the configuration is as follows: the first gap 232d included in the first gap group 231 is disposed between the first gaps 235c and 235e included in the second gap group 234 which are adjacent to the first gap 232d on one side of the circumference; and the first gap 232e included in the first gap group 231 is disposed between the first gaps 235b and 235d included in the second gap group 234 which are adjacent to the first gap 232e on the other side of the circumference. Alternatively, the configuration may be as follows: the first gap 235d included in the second gap group 234 is disposed between the first gaps 232c and 232e included in the first gap group 231 that are adjacent to the first gap 235d on one side of the circumference, and the first gap 235e included in the second gap group 234 is disposed between the first gaps 232b and 232d included in the first gap group 231 that are adjacent to the first gap 235e on the other side of the circumference.

Next, the elastic portion 230 of the handle in the third embodiment will be described with reference to FIG6.

In this embodiment, the elastic portion 230 is divided into a first gap group 231 and a second gap group 234. The first gap group 231 includes first gaps 232a to 232c extending circumferentially and second gaps 233a to 233d extending axially. The second gap group 234 includes first gaps 235a to 235c extending circumferentially and second gaps 236a to 236d extending axially. Furthermore, similar to the first embodiment, it is divided into two first gap groups 231 and two second gap groups 234.

Furthermore, the first gaps 232a to 232c and the second gaps 233a to 233d included in the first gap group 231 are arranged to be continuous.

Specifically, the second gap 233a extends axially toward the top end from the end of the first gap 232a on one circumferential side (the upper side in FIG. 6), which extends circumferentially. The second gap 233b extends axially toward the top end from the end of the first gap 232a on the other circumferential side (the lower side in FIG. 6). Furthermore, the first gap 232b extends circumferentially toward the other circumferential side from the end of the second gap 233a on the top side. The second gap 233c extends axially toward the rear end from the end of the first gap 232b on the other circumferential side. Furthermore, the first gap 232c extends circumferentially toward one circumferential side from the end of the second gap 233b after the top end. The second gap 233d extends axially toward the rear end from the end of the first gap 232c on one circumferential side.

Similarly, the first gaps 235a to 235c and the second gaps 236a to 236d included in the second gap group 234 are arranged to be continuous.

Specifically, the second gap 236a extends axially toward the rear end from one circumferential end of the first gap 235a, which extends circumferentially, and the second gap 236b extends axially toward the rear end from the other circumferential end of the first gap 235a. Furthermore, the first gap 235b extends circumferentially toward the other circumferential side from the rear end of the second gap 236a, and the second gap 236c extends axially toward the top end from the other circumferential end of the first gap 235b. Additionally, the first gap 235c extends circumferentially toward one circumferential side from the rear end of the second gap 236b, and the second gap 236d extends axially toward the top end from one circumferential end of the first gap 235c.

In addition, in this embodiment, the first gaps 232a-232c, 235a-235c and the second gaps 233a-233d, 236a-236d have a straight shape.

Furthermore, the circumferential configuration of the first gaps 232a-232c and the second gaps 233a-233d included in the first gap group 231 is set to be point-symmetric with the circumferential configuration of the first gaps 235a-235c and the second gaps 236a-236d included in the second gap group 234.

Furthermore, the void group is configured such that at least a portion overlaps with at least one other void group along the circumferential and axial directions.

In this embodiment, the first gap group 231 and the second gap group 234 are arranged alternately along the circumferential direction, and the first gap group 231 and the second gap group 234 that are adjacent in the circumferential direction are arranged to partially overlap in the circumferential and axial directions.

Specifically, the configuration is as follows: the second gap 233c included in the first gap group 231 is disposed between the second gaps 236b and 236d included in the second gap group 234 which are adjacent to the second gap 233c on one side of the circumference, and the second gap 233d included in the first gap group 231 is disposed between the second gaps 236a and 236c included in the second gap group 234 which are adjacent to the second gap 233d on the other side of the circumference. Alternatively, the configuration may be as follows: the second gap 236c included in the second gap group 234 is disposed between the second gaps 233b and 233d included in the first gap group 231 that are adjacent to the second gap 236c on one side of the circumference, and the second gap 236d included in the second gap group 234 is disposed between the second gaps 233a and 233c included in the first gap group 231 that are adjacent to the second gap 236d on the other side of the circumference.

As described above, in the first to third embodiments, the axial and circumferential stresses acting on the tap during tapping can be absorbed by the simple elastic part 230 (first elastic part).

Furthermore, the elastic characteristics (contraction elastic characteristics) of the elastic portion 230 (first elastic portion) along the axial direction toward the rear end can be adjusted using O-rings 461 (second elastic portion) and O-rings 462 (third elastic portion). The O-rings 461 (second elastic portion) and the elastic portion 230 (first elastic portion) elastically deform along the axial direction toward the rear end in conjunction with each other. The O-rings 462 (third elastic portion) and the tool held by the tool holder (the end face of the tool's rear end) elastically deform along the axial direction toward the rear end in conjunction with each other. In other words, the contraction and elongation elastic characteristics of the elastic portion 230 (first elastic portion) can be appropriately set. Therefore, stress caused by feed errors and stress caused by the tap tip's cutting can be effectively absorbed without reducing machining accuracy.

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

The first gap extending circumferentially includes a gap extending generally circumferentially, and the second gap extending axially includes a gap extending generally axially.

The first elastic part (elastic part 230) has a continuous gap between a first gap extending in the circumferential direction and a second gap extending in the axial direction, but it is also possible to form the first gap and the second gap separately and independently.

The plurality of first gaps extending circumferentially and the plurality of second gaps extending axially are divided into a plurality of gap groups including the first gaps and the second gaps, and are arranged in the first elastic part (elastic part 230) in units of gap groups, but they can also be arranged in the first elastic part in units of the first gaps and the second gaps.

The number, shape, and arrangement of the first gap extending circumferentially and the second gap extending axially can be appropriately varied within the range of elastic deformation of the first elastic part (elastic part 230) in both the circumferential and axial directions.

The gap formed in the first elastic part (elastic part 230) is not limited to a first gap extending in the circumferential direction and a second gap extending in the axial direction, and can be appropriately varied within the range that the first elastic part can elastically deform in the circumferential and axial directions. For example, a gap extending in a cross shape with the axial and circumferential directions along the outer peripheral surface of the main body can also be formed in the first elastic part.

An O-ring is used as the second elastic part, which is located on the rear end side of the first cylindrical member (collar 410) and can be elastically deformed in conjunction with the axial movement of the first cylindrical member. However, various elastic members other than the O-ring can be used as the second elastic part.

An O-ring is used as the third elastic part, which is located on the rear end side of the second cylindrical member (support member 420) and can be elastically deformed in conjunction with the axial movement of the rear end of the tool. However, as the third elastic part, various elastic members other than the O-ring can be used.

It has a first elastic part and a second elastic part, but either or both of the first elastic part and the second elastic part can be omitted.

The tool holder of the present invention is suitable for use when holding a tap for forming an internal thread hole in a workpiece, but can also be used when holding various other cutting tools besides taps.

The structures described in the embodiments can be used individually or in combination as appropriate.

The present invention can be configured as (Form 1),

In this (Version 1), "the handle includes a main body having an inner circumferential surface and an outer circumferential surface, the main body having a handle portion at the rear end and a tool grip portion at the top end, characterized in that..."

The main body portion has a first elastic portion between the shank portion and the tool holding portion.

The first elastic portion has multiple gaps that connect the inner circumferential surface of the main body portion to the outer circumferential surface of the main body portion, thereby enabling it to elastically deform along the axial and circumferential directions.

The knife handle has the following features:

A first cylindrical member, disposed on the outer periphery of the main body, is capable of moving axially in conjunction with the elastic deformation of the first elastic portion along the axial direction; and

The second elastic part is located on the rear end side of the first cylindrical member and is capable of elastic deformation in conjunction with the axial movement of the first cylindrical member.

Furthermore, the present invention can be configured as (Form 2).

In this (Form 2), "based on the handle of Form 1, the feature of this (Form 2) is that the handle has:

The second cylindrical member, disposed on the inner circumferential side of the main body, is capable of moving axially in conjunction with the axial movement of the rear end of the tool held by the tool holder; and

The third elastic part is located on the rear end side of the second cylindrical member and is capable of elastic deformation in conjunction with the axial movement of the second cylindrical member.

In the cases of tool holders of forms 1 and 2, the elastic characteristics of the first elastic part when it deforms axially toward the rear end (contraction elastic characteristics) can be set to be stronger than the elastic characteristics of the first elastic part when it deforms axially toward the tip (elongation elastic characteristics) by utilizing the elastic characteristics of the second elastic part or the elastic characteristics of both the second and third elastic parts. Thus, for example, the weaker contraction elastic characteristics can be used to absorb the stress generated by the difference between the tap pitch and the machine feed, preventing thread wear. On the other hand, the stronger elongation elastic characteristics can be used to absorb the stress generated when the tap tip cuts into the workpiece, preventing shallow tap depths.

Explanation of reference numerals in the attached figures

10. Cutting tool; 11. Holding part; 12. Holding surface; 13. Cutting tool end face; 100. Tool holder; 200. Main body; 210. Shank; 220. Cutting tool grip; 230. Elastic part (first elastic part); 231. First clearance group; 232a, 232b, 232c, 232d, 232e, first clearance; 233a, 233b, 233c, 233d, second clearance; 234. Second clearance group; 235a, 235b, 235c, 235d 235e, First gap; 236a, 236b, 236c, 236d, Second gap; 240, Inner circumferential surface of the main body; 241-245, Inner circumferential surface portion of the first main body to the inner circumferential surface portion of the fifth main body; 250, Outer circumferential surface of the main body; 251-256, Outer circumferential surface portion of the first main body to the outer circumferential surface portion of the sixth main body; 260, Inner space of the main body; 261-263, Inner space portion of the first main body to the inner space portion of the third main body; 271, Hole wall surface; 27 2. Hole; 273. Hole wall surface; 274. Connecting hole; 300. Tool holding mechanism; 310. Collar; 320. Engaging component; 330. Fastening tool; 400. Stress absorption mechanism; 410. Collar (first cylindrical component); 411. Inner circumferential surface of the collar; 412. Outer circumferential surface of the collar; 413. Rear end face of the collar; 415. 417. Hole wall surface; 416. 418. Connecting hole; 420. Support component (second cylindrical component); 421. Inner circumferential surface of the support component; 422. Support 423. Outer peripheral surface of component; 425. Rear end face of support component; 426. Hole wall surface; 430. Hole; 431. Position adjustment component; 432. Inner peripheral surface of position adjustment component; 434. Outer peripheral surface of position adjustment component; 441. Pin, 442. Pin; 450. Cap; 451. Cylindrical part; 452. Bottom; 453. Hole wall surface; 461. O-ring seal (second elastic part); 462. O-ring seal (third elastic part); 463. O-ring seal.

Claims (5)

1. A knife handle, The knife handle includes a main body having an inner circumferential surface and an outer circumferential surface, the main body having a handle portion at the rear end and a knife grip portion at the top end, the knife handle being characterized in that... The main body portion has a first elastic portion between the shank portion and the tool holding portion. The first elastic portion has a plurality of first gaps and a plurality of second gaps, which communicate between the inner circumferential surface of the main body and the outer circumferential surface of the main body. The first elastic portion is configured to be elastically deformable along the axial and circumferential directions. The first gap extends circumferentially in such a way that at least a portion overlaps with at least one other first gap in the circumferential direction to achieve axial elastic deformation of the first elastic portion. The second gap extends axially in such a way that at least a portion overlaps with at least one other second gap in the axial direction to achieve axial and circumferential elastic deformation of the first elastic portion. The plurality of first gaps and the plurality of second gaps are divided into a plurality of gap groups, including a first gap group and a second gap group, wherein the first gap group and the second gap group include a first gap and a second gap. The first and second gaps included in the gap group are continuous. The first gap group and the second gap group are arranged alternately along the circumferential direction, and adjacent first gap groups and second gap groups in the circumferential direction are arranged to partially overlap in the circumferential and axial directions. 2. The knife handle according to claim 1, characterized in that, The first gap group and the second gap group include the same number of first gaps and the same number of second gaps, and the configuration shape of the first gaps and second gaps included in the first gap group is different from the configuration shape of the first gaps and second gaps included in the second gap group. 3. The knife handle according to claim 1 or 2, characterized in that, The knife handle has the following features: A first cylindrical member, disposed on the outer periphery of the main body, is capable of moving axially in conjunction with the elastic deformation of the first elastic portion along the axial direction; and The second elastic part is provided on the rear end side of the first cylindrical member and is capable of elastic deformation in conjunction with the axial movement of the first cylindrical member. 4. The knife handle according to claim 1 or 2, characterized in that, The knife handle has the following features: The second cylindrical member, disposed on the inner circumferential side of the main body, is capable of moving axially in conjunction with the axial movement of the rear end of the tool held by the tool holder; and The third elastic part is provided on the rear end side of the second cylindrical member and is capable of elastic deformation in conjunction with the axial movement of the second cylindrical member. 5. The knife handle according to claim 3, characterized in that, The knife handle has the following features: The second cylindrical member, disposed on the inner circumferential side of the main body, is capable of moving axially in conjunction with the axial movement of the rear end of the tool held by the tool holder; and The third elastic part is provided on the rear end side of the second cylindrical member and is capable of elastic deformation in conjunction with the axial movement of the second cylindrical member.