Tool holding structure and tool take-out method

Abstract

To provide a tool holding structure in which a cutting tool can be easily removed even if the cutting tool is broken, and a tool take-out method.SOLUTION: A tool holding structure comprises a cylindrical tool holder 1 which holds a cutting tool T, and rotates around a rotation axis X. The tool holder 1 has: a chuck part 12 which is provided one side in the rotation axis X direction, and can receive a shank part 2 of the cutting tool T; a collet 30 which holds the shank part 2 of the cutting tool T, and is inserted in the chuck part 12 and held coaxially with the rotation axis X; and a cylindrical connection member 40 which is located on the other side in the rotation axis X direction with respect to the collet 30, and is connected to the collet 30. The connection member 40 is attachable / detachable to / from an inner surface of the tool holder 1, is moved toward one side by an operation from the other side in the rotation axis X direction of the tool holder 1 to push the collet 30 along the rotation axis X direction, thereby enabling drawal the tool T together with the collet 30 from the chuck part 12.SELECTED DRAWING: Figure 4

Description

[Technical Field]

[0001] The present invention relates to a tool holding structure for inserting and holding the shank portion of a cutting tool into a chuck portion of a tool holder or the like, and to a method for removing the tool from the tool holder or the like. [Background technology]

[0002] For example, Patent Document 1 discloses such a tool holding structure, which holds the shank of a cutting tool via a collet inserted into a chuck. This tool holding structure is provided with a mechanism for preventing the cutting tool from coming off and rotating relative to the chuck. Specifically, a fitting member that fits into an internal fitting formed on the inner surface of the chuck is arranged so as to be exposed from the outer surfaces of the collet and the shank of the cutting tool. The fitting member fits into the internal fitting of the chuck, thereby preventing the cutting tool from coming off and rotating relative to the chuck. [Prior art documents] [Patent documents]

[0003] [Patent Document 1] International Publication No. 2014 / 103350 Summary of the Invention [Problem to be solved by the invention]

[0004] In the tool holding structure described in Patent Document 1, the collet inserted into the chuck portion may be attached to the inner surface of the tool holder. The collet is attached to the tool holder by manipulating the collet or a member connected to the collet, and this operation is performed from the opening side of the chuck portion. In such a configuration, a cutting tool held in the tool holder may break near the opening of the chuck portion during machining. In this case, if the cutting tool protruding from the chuck portion of the tool holder is short, it may be difficult to properly remove the cutting tool from the opening side of the chuck portion. This makes it difficult to remove the cutting tool from the tool holder. Thus, there is room for improvement in the tool holding structure for a cutting tool attached to the chuck portion via a collet.

[0005] In view of the above circumstances, there is a need for a tool holding structure and a tool removal method that allow cutting tools to be easily removed even if the cutting tool is broken. [Means for solving the problem]

[0006] A characteristic configuration of a tool holding structure according to the present invention is that it comprises a cylindrical tool holder that holds a cutting tool and rotates about a rotation axis, the tool holder having a chuck portion that is provided on one side in the direction of the rotation axis and that can receive a shank portion of the cutting tool, a collet that holds the shank portion of the cutting tool and is inserted into the chuck portion to be held coaxially with the rotation axis, and a cylindrical connecting member that is located on the other side of the collet in the direction of the rotation axis and is connected to the collet, the connecting member being attachable to and detachable from the inner surface of the tool holder, and that can be operated from the other side in the direction of the rotation axis of the tool holder to move toward one side and push the collet along the rotation axis, thereby allowing the cutting tool and the collet to be removed from the chuck portion.

[0007] According to this configuration, the cutting tool can be removed from the chuck portion together with the collet by operating the connecting member from the other side of the tool holder to move the connecting member toward one side and push the collet along the rotation axis. Therefore, even if the shank of the cutting tool breaks during cutting or the like and it is difficult to remove the cutting tool by operating the cutting tool from the open side of the chuck portion, the cutting tool can be easily removed from the chuck portion by operating from the other side of the tool holder. Furthermore, because the cutting tool is held by the collet in the chuck portion of the tool holder, the inner surface of the chuck portion located on the outer periphery of the collet is unlikely to be damaged when the cutting tool breaks. Furthermore, when removing the cutting tool from the chuck portion, the cutting tool is removed from the chuck portion together with the collet, so the inner surface of the chuck portion is unlikely to be damaged. Therefore, even if the cutting tool breaks during cutting or the like, the tool holder can be continued to be used by replacing only the collet.

[0008] Another characteristic feature is that the connecting member has a first connecting member arranged on the one side and a second connecting member arranged on the other side, the first connecting member configured to be connectable to the collet, and the second connecting member configured to be connectable to the first connecting member and to be attachable and detachable to the inner surface of the tool holder.

[0009] According to this configuration, since the connecting member is composed of the first connecting member and the second connecting member, the position of the collet can be easily adjusted by the connecting member when assembling the collet to the tool holder. Furthermore, by providing a plurality of first connecting members and a plurality of second connecting members, it is possible to easily configure connecting members that fit various inner shapes of tool holders.

[0010] Another characteristic configuration is that the collet has a female threaded portion provided on the other side, the second connecting member has a female threaded portion provided on the one side and a male threaded portion that can be screwed into the female threaded portion provided on the inner surface of the tool holder, the first connecting member has a first male threaded portion that can be screwed into the female threaded portion of the collet and a second male threaded portion that can be screwed into the female threaded portion of the second connecting member, and the thread diameter of the male threaded portion of the second connecting member is larger than the thread diameters of the first male threaded portion and the second male threaded portion of the first connecting member.

[0011] According to this configuration, the collet has a female threaded portion, the first connecting member has male threaded portions on both sides in the direction of the rotation axis, and the second connecting member has a female threaded portion and a male threaded portion on both sides in the direction of the rotation axis, so that the connecting member can reliably connect the first connecting member to the collet while reliably assembling the second connecting member to the inner surface of the tool holder. Furthermore, the thread diameter of the male threaded portion of the second connecting member is larger than the thread diameter of both male threaded portions of the first connecting member, so that the connecting member can be stably fixed to the inner surface of the tool holder. This allows the collet connected to the connecting member to be stably held in an orientation along the rotation axis.

[0012] Another characteristic configuration is that the collet has a female threaded portion provided on the other side, the second connecting member has a female threaded portion provided on the one side and a male threaded portion that can be screwed into the female threaded portion provided on the inner surface of the tool holder, the first connecting member has a first male threaded portion that can be screwed into the female threaded portion of the collet and a second male threaded portion that can be screwed into the female threaded portion of the second connecting member, and the thread pitch of the male threaded portion of the second connecting member and the thread pitch of the second male threaded portion of the first connecting member are configured to be different.

[0013] If the thread pitch of the male thread portion of the second connecting member and the thread pitch of the second male thread portion of the first connecting member are the same, even if the second connecting member is rotated, the first connecting member will rotate along with the second connecting member until the end face of the second connecting member abuts the first connecting member, preventing the first connecting member from moving toward the collet. Therefore, in this configuration, the male thread portion of the second connecting member and the second male thread portion of the first connecting member are configured with different thread pitches. In this configuration, if the thread pitch of the male thread portion of the second connecting member is larger than the thread pitch of the second male thread portion of the first connecting member, the second connecting member is rotated from the other side of the tool holder so that the second connecting member moves toward one side of the tool holder. In this way, when the second connecting member rotates once, the distance of movement of the second connecting member toward the collet is greater than the distance of movement of the first connecting member away from the collet, so that the first connecting member can be moved integrally with the second connecting member toward one side of the rotation axis. Conversely, if the thread pitch of the male thread portion of the second connecting member is smaller than the thread pitch of the second male thread portion of the first connecting member, the second connecting member is rotated from the other side of the tool holder so that the second connecting member moves toward the other side of the tool holder. In this way, when the second connecting member rotates once, the movement distance of the first connecting member toward one side in the rotation axis direction is greater than the movement distance of the second connecting member toward the other side in the rotation axis direction, so the first connecting member can be moved toward one side in the rotation axis direction. As a result, the cutting tool can be efficiently removed from the tool holder.

[0014] A feature of a tool removal method according to the present invention is that the method removes a cutting tool held in a tool holder from the tool holder, the method comprising: a cylindrical tool holder that holds the cutting tool and rotates about a rotation axis, the tool holder having a chuck portion that is provided on one side in a direction of the rotation axis and that can receive a shank portion of the cutting tool; a collet that holds the shank portion of the cutting tool and is inserted into the chuck portion to be held coaxially with the rotation axis; and a cylindrical connecting member that is disposed on the other side of the collet in the direction of the rotation axis and connected to the collet, the cutting tool and the collet can be removed from the chuck portion by operating the connecting member from the other side of the tool holder in the direction of the rotation axis and moving the connecting member toward the one side to push the collet along the direction of the rotation axis of the tool holder.

[0015] According to this method, by operating the connecting member from the other side of the tool holder, the connecting member moves to one side in the rotation axis direction and pushes the collet along the rotation axis direction, thereby removing the cutting tool together with the collet from the chuck portion. Therefore, even if the shank of the cutting tool breaks during cutting or the like, making it difficult to remove the cutting tool by operating the cutting tool from the open side of the chuck portion, the cutting tool can be easily removed from the chuck portion by operating from the other side of the tool holder. Furthermore, because the cutting tool is held by the collet in the chuck portion of the tool holder, the inner surface of the chuck portion located on the outer periphery of the collet is unlikely to be damaged when the cutting tool breaks. Furthermore, when removing the cutting tool from the chuck portion, the cutting tool is removed from the chuck portion together with the collet, so the inner surface of the chuck portion is unlikely to be damaged. Therefore, even if the cutting tool breaks during cutting or the like, the tool holder can be continued to be used by replacing only the collet.

[0016] A feature of a tool removal method according to the present invention is a tool removal method for removing a cutting tool held in a tool holder from the tool holder, the tool holder comprising: a cylindrical tool holder that holds the cutting tool and rotates about a rotation axis, the tool holder having: a chuck portion that is provided on one side in a direction of the rotation axis and that can receive a shank portion of the cutting tool; a collet that holds the shank portion of the cutting tool and is inserted into the chuck portion to be held coaxially with the rotation axis; and a cylindrical connecting member that is arranged on the other side of the collet in the direction of the rotation axis and connected to the collet, the connecting member having a first connecting member arranged on the one side and a second connecting member arranged on the other side in the direction of the rotation axis, the first connecting member being configured to be connectable to the collet, and the second connecting member being connectable to the first connecting member and detachably attached to the inner surface of the tool holder. the collet has a female threaded portion on the other side, the second connecting member has a female threaded portion on the one side and a male threaded portion that can be screwed into the female threaded portion on the inner surface of the tool holder, the first connecting member has a first male threaded portion that can be screwed into the female threaded portion of the collet and a second male threaded portion that can be screwed into the female threaded portion of the second connecting member, and the thread pitch of the male threaded portion of the second connecting member is configured to be different from the thread pitch of the second male threaded portion of the first connecting member, and by rotating the second connecting member, the first connecting member is moved toward the one side by an amount equal to the pitch difference between the thread pitch of the male threaded portion of the second connecting member and the thread pitch of the second male threaded portion of the first connecting member, and the collet is pushed along the rotation axis of the tool holder, thereby extracting the cutting tool together with the collet from the chuck portion.

[0017] According to this method, the connecting member connected to the collet has a first connecting member arranged on one side in the rotational axis direction and a second connecting member arranged on the other side in the rotational axis direction. By rotating the second connecting member, the first connecting member is moved toward one side in the rotational axis direction by the pitch difference between the thread pitch of the male thread portion of the second connecting member and the thread pitch of the second male thread portion of the first connecting member, thereby pushing the collet along the rotational axis and removing the cutting tool together with the collet from the chuck portion. Therefore, in a tool holder having a connecting member composed of two parts, even if the shank of the cutting tool breaks during cutting or other processing, making it difficult to remove the cutting tool by operating the cutting tool through the open side of the chuck portion, the cutting tool can be easily removed from the chuck portion by operating the other side of the tool holder. Furthermore, because the cutting tool is held by the collet in the chuck portion of the tool holder, the inner surface of the chuck portion located on the outer periphery of the collet is less likely to be damaged when the cutting tool breaks. Furthermore, when removing the cutting tool from the chuck, the cutting tool is removed together with the collet, so the inner surface of the chuck is less likely to be damaged. Therefore, even if the cutting tool breaks during cutting, the tool holder can be continued to be used by simply replacing the collet. [Brief explanation of the drawings]

[0018] [Figure 1] FIG. 2 is a cross-sectional view of the tool holder in the first embodiment with a tool attached thereto. [Figure 2] FIG. 2 is an exploded perspective view of the tool holder and the cutting tool according to the first embodiment. [Figure 3] FIG. 10 is a cross-sectional view showing a protrusion inserted into a fitting portion. [Figure 4] 5A to 5C are cross-sectional views showing an operation of removing a tool from a tool holder in the first embodiment. [Figure 5] FIG. 10 is a cross-sectional view of a tool holder with a tool attached thereto in a second embodiment. [Figure 6] FIG. 10 is an exploded perspective view of a tool holder and a cutting tool according to a second embodiment. [Figure 7]10A and 10B are cross-sectional views showing an operation of removing a tool from a tool holder in the second embodiment. [Figure 8] FIG. 11 is a cross-sectional view of a tool holder with a tool attached thereto according to a third embodiment. [Figure 9] FIG. 10 is an exploded perspective view of a tool holder and a cutting tool according to a third embodiment. [Figure 10] 10A and 10B are cross-sectional views showing an operation of removing a tool from a tool holder in the third embodiment.

[0019] Hereinafter, embodiments of the present invention will be described in detail with reference to the drawings. Note that the embodiments described below are merely examples for explaining the present invention, and the present invention is not limited to these embodiments. Therefore, the present invention can be implemented in various forms without departing from the gist of the present invention.

[0020] [First embodiment] [Tool holder and cutting tool] 1 and 2, the tool holder 1 comprises a holder body 10 having a tapered mounting portion 11 that is mounted in a fitted state on a machine tool (not shown), and a chuck portion 12 into which a cutting tool T (hereinafter abbreviated as "tool T") is inserted. The tool holder 1 is provided with a fastening ring 5 that is mounted on an outer peripheral surface 12S of the chuck portion 12, and is a specific example of a tool holding structure that holds the tool T inserted into the chuck portion 12.

[0021] The tool holder 1 is formed into a cylindrical shape with a rotation axis X (hereinafter abbreviated as "axis X") as its center, and rotates around the axis X when mounted on a machine tool (not shown). A cylindrical internal space 13 is formed inside the holder body 10, extending from the chuck portion 12 toward the mounting portion 11 and centered on the axis X. Hereinafter, in the axis X direction of the tool holder 1, the side of the chuck portion 12 will be referred to as the X1 side (tip side, an example of one side), and the side of the mounting portion 11 will be referred to as the X2 side (base end side, an example of the other side).

[0022] The tool T has a shank portion 2 and a cutting edge portion 3 that performs cutting. As shown in FIG. 1, the tool T is supported by inserting the shank portion 2 into a collet 30. That is, the collet 30 is included in a tool holder 1 that serves as a tool holding structure. The shank portion 2 of the tool T is inserted into an internal space 13 of a chuck portion 12 together with the collet 30. The collet 30 is inserted into and held in the chuck portion 12. In the following explanation, the center of rotation of the tool T will also be described as the axis X.

[0023] Collet 30 is cylindrical and has an outer peripheral portion 30a that fits tightly against the inner surface of internal space 13, and an inner peripheral portion 30b that fits tightly against the outer periphery of small-diameter tool T. Collet 30 has a plurality of slit-shaped split spaces 32 formed along axis X. Split space 32a, one of the plurality of split spaces 32, has a guide hole 33 on the tip side through which protrusion 22 of fitting member 20 can pass, and a fitting hole portion B is formed on the X2 side of guide hole 33 so that fitting member 20 can move circumferentially around collet 30.

[0024] The tool holder 1 uses a fitting member 20 that fits into an outer fitting portion A on the outer surface of the shank portion 2 of the tool T and into a fitting hole portion B of the collet 30, thereby preventing the tool T from slipping out of the tool holder 1 and preventing the tool T from rotating relative to the tool holder 1. As shown in FIGS. 1 and 2, the fitting member 20 integrally forms a base portion 21 that fits into the outer fitting portion A of the shank portion 2 and a protrusion 22 that protrudes outward. The outer fitting portion A is determined by standards and is composed of a fitting surface that is formed by cutting a portion of the outer surface of the shank portion 2 of the tool T flat.

[0025] The tool holder 1 including the collet 30 is assumed to be driven and rotated counterclockwise during cutting when viewed from the X1 side to the X2 side. Fig. 3 shows the fitting hole B when the collet 30 is viewed radially outward from the axis X, i.e., when the inner peripheral portion 30b of the collet 30 is viewed. As shown in Fig. 3, the fitting hole B provided in the collet 30 has a rotation-preventing surface Bx with which the fitting member 20 abuts in the direction in which the shank portion 2 rotates relative to the collet 30, and a withdrawal-preventing surface By with which the fitting member 20 abuts in the direction in which the shank portion 2 withdraws from the collet 30. The arrow S indicates the rotation direction of the tool holder.

[0026] 1, the inner peripheral surface 5S of the fastening ring 5 is formed in a parallel position to the outer peripheral surface 12S of the chuck portion 12, and multiple needle rollers 6 are arranged between the inner peripheral surface 5S of the fastening ring 5 and the outer peripheral surface 12S of the chuck portion 12. The multiple needle rollers 6 are arranged on a spiral axis around the outer periphery of the outer peripheral surface 12S of the chuck portion 12, and when the fastening ring 5 is rotated in a predetermined direction, the multiple needle rollers 6 revolve around the axis X while rotating along the outer peripheral surface 12S of the chuck portion 12. As a result, the multiple needle rollers 6 ride up onto the outer peripheral surface 12S of the chuck portion 12, applying pressure to the chuck portion 12 and reducing the diameter of the internal space 13.

[0027] In addition, a seal is provided between the inner surface 5S of the end of the fastening ring 5 and the outer surface 12S of the chuck portion 12, and a ring plate 8 for holding the seal is attached to the end of the opening side of the chuck portion 12.

[0028] As shown in Fig. 1, a female thread portion 35 is formed along the axial direction X at the end on the X2 side of the collet 30. As shown in Figs. 1 and 2, a connecting member 40 is attached to the female thread portion 35 to adjust the position of the collet 30 in the axial direction X.

[0029] The connecting member 40 is formed in a cylindrical shape along the axial core X direction and includes a large diameter portion 41 provided on the central side in the axial core X direction, a first small diameter portion 42 provided on the X1 side in the axial core X direction, and a second small diameter portion 43 provided on the X2 side in the axial core X direction. The small diameter portions 42, 43 each have an outer periphery that is male threaded. Specifically, when viewed from the X2 side to the X1 side in the state of FIG. 1 (hereinafter referred to as "viewed toward the X1 direction"), the first small diameter portion 42 has a first male threaded portion 44 that is a right-handed thread provided on the outer periphery, and the first male threaded portion 44 is screwed into the female threaded portion 35 of the collet 30. In other words, the cylindrical connecting member 40 is disposed on the X2 side in the axial core X direction with respect to the collet 30 and is connected to the collet 30. When viewed from the X1 side to the X2 side in the state of Figure 1 (hereinafter referred to as "when viewed toward the X2 direction"), the second small diameter portion 43 has a second right-handed male threaded portion 45 provided on its outer periphery, and the second male threaded portion 45 is screwed into the female threaded portion 16 provided on the X2 side of the internal space 13 of the holder body 10.

[0030] In this embodiment, a threaded hole 17 having a diameter larger than the thread diameter (inner diameter) of the female threaded portion 16 is formed on the X2 side of the female threaded portion 16, and one end of a coolant passage member (not shown) is screwed into the threaded hole 17 for assembly.

[0031] 1, in the connecting member 40, the thread diameter (outer diameter) W1 of the first male threaded portion 44 is larger than the thread diameter (outer diameter) W2 of the second male threaded portion 45. Although not shown, in the connecting member 40, depending on the internal space 13 of the holder body 10, the thread diameter (outer diameter) W2 of the second male threaded portion 45 may be larger than the thread diameter (outer diameter) W1 of the first male threaded portion 44, or the thread diameter (outer diameter) W1 of the first male threaded portion 44 and the thread diameter (outer diameter) W2 of the second male threaded portion 45 may be the same.

[0032] The connecting member 40 has a through hole 46 along the axis X. A hole 47 (e.g., a hexagonal hole) is formed at the end on the X1 side of the through hole 46, with which the tip of a rotation operating tool R (e.g., a wrench, see FIG. 4) can be engaged. Also, a hole 48 (e.g., a hexagonal hole) is formed at the end on the X2 side of the through hole 46, with which the tip of the rotation operating tool R can be engaged.

[0033] [Tool mounting style] A female screw portion 16 for fixing the connecting member 40 is provided on the X2 side of the internal space 13 of the holder body 10.

[0034] First, the connecting member 40 is attached to the collet 30. Specifically, the small diameter portion 42 (first male thread portion 44) of the connecting member 40 is screwed onto the female thread portion 35 of the collet 30. Because the first male thread portion 44 is a right-handed thread, the connecting member 40 is rotated clockwise relative to the collet 30.

[0035] Next, the collet 30 to which the connecting member 40 is connected is assembled into the internal space 13 of the holder body 10. Specifically, a jig such as a rotation operating tool R (see FIG. 4) is inserted into the hole 47 formed in the first male threaded portion 44, and the second male threaded portion 45 of the connecting member 40 is screwed into the female threaded portion 16 on the inner surface of the holder body 10. Because the second male threaded portion 45 is a right-handed thread, the collet 30 to which the connecting member 40 is attached is attached to the holder body 10 by rotating the rotation operating tool R clockwise when viewed in the X2 direction.

[0036] Next, the tool T is attached to the tool holder 1. A spring 7 is inserted in advance as a biasing mechanism into the collet 30 arranged in the internal space 13 of the chuck portion 12, and the fitting member 20 is fitted into the outer fitting portion A of the shank portion 2 of the tool T to hold it in a aligned state.

[0037] Next, the shank portion 2 of the tool T supporting the fitting member 20 is inserted into the collet 30. At this time, the protrusion 22 of the fitting member 20 is inserted into the guide hole 33 of the collet 30 and moves along the guide hole 33. In this way, the shank portion 2 of the tool T moves from the opening side of the chuck portion 12 to the X2 side, and when the inner end of the shank portion 2 comes into contact with the spring 7, the spring 7 acts on the tool T with a biasing force in the push-out direction.

[0038] Next, as shown in FIG. 3 , the tool T is rotated to bring the protrusion 22 of the fitting member 20 into contact with the circumferential end surface of the fitting hole B of the collet 30, which serves as the rotation-preventing surface Bx. This keeps the tool T from rotating relative to the collet 30. In addition, in this state, the biasing force of the spring 7 brings the end of the protrusion 22 into contact with the withdrawal-preventing surface By. In this way, when the tool T is rotated in a direction in which the fitting member 20 abuts against the rotation-preventing surface Bx, the end of the protrusion 22 of the fitting member 20 abuts against the withdrawal-preventing surface By, thereby preventing the tool T from unintentionally falling out of the tool holder 1.

[0039] After the setting of the tool T in the tool holder 1 is completed, the fastening ring 5 is rotated in a predetermined direction, whereby pressure is applied from the needle rollers 6 to the outer peripheral surface 12S of the chuck portion 12, thereby reducing the diameter of the internal space 13. Due to this reduction in diameter, the collet 30 is pressed against the inner peripheral surface of the chuck portion 12 (the inner peripheral surface of the internal space 13), and the tool T is held in the tool holder 1.

[0040] [Tool removal method 1] If the tool T is not broken and can be rotated after the diameter reduction by the fastening ring 5 is released from the chuck portion 12, the reverse operations of the operations shown in the above-described mounting form are sequentially performed. This allows the tool T to be removed from the tool holder 1.

[0041] [Tool removal method 2] On the other hand, if the tool T breaks during cutting, for example, and the remaining tool T only protrudes a short distance from the collet 30, the tool T may not be able to be rotated even if the diameter reduction by the fastening ring 5 is released from the chuck portion 12. Therefore, in this embodiment, the tool holder 1 is configured so that the tool T can be extracted from the chuck portion 12 together with the collet 30 and the connecting member 40 by operating the holder body 10 from the X2 side in the axial X direction, thereby moving the connecting member 40 in the X1 direction and pushing the collet 30 along the axial X direction.

[0042] Specifically, after releasing the diameter reduction by the fastening ring 5, as shown in FIG. 4 , the rotation operating device R is inserted from the X2 side of the axial center X of the tool holder 1, and the end of the rotation operating device R is engaged with the hole 48 formed in the second male thread portion 45 of the connecting member 40. The rotation operating device R is then rotated clockwise as viewed in the X1 direction to rotate the connecting member 40 clockwise. When the second male thread portion 45, which is a right-handed thread, rotates clockwise as viewed in the X1 direction, its fastening to the holder body 10 is loosened. This causes the connecting member 40 to move in the X1 direction. This movement of the connecting member 40 in the X1 direction also causes the collet 30, which is screwed to the connecting member 40, to move in the X1 direction. When the second male thread portion 45 is unscrewed from the holder body 10, the tool T can be removed from the chuck portion 12 together with the collet 30 and the connecting member 40. Thereafter, the tool T can be released from the collet 30 by rotating the X1 side end of the collet 30 extracted from the chuck portion 12 using various jigs.

[0043] Therefore, even if the shank of the tool T breaks during cutting or the like and it is difficult to remove the tool T by operating the tool T from the X1 side (opening side) of the chuck portion 12, the tool T can be easily removed from the chuck portion 12 by operating the tool from the X2 side (the other side) of the tool holder 1. Furthermore, because the tool T is held by the collet 30 in the chuck portion 12 of the tool holder 1, the inner surface of the chuck portion 12 located on the outer periphery of the collet 30 is unlikely to be damaged when the tool T breaks. Furthermore, when removing the tool T from the chuck portion 12, the tool T is extracted from the chuck portion 12 together with the collet 30, so the inner surface of the chuck portion 12 is unlikely to be damaged. Therefore, even if the tool T breaks during cutting or the like, the tool holder 1 can continue to be used by replacing only the collet 30.

[0044] Second Embodiment 5 to 7, the second embodiment differs from the first embodiment in that the connecting member 40 is composed of a first connecting member 50 and a second connecting member 60. The configuration other than the connecting member 40 is the same as that of the first embodiment, and therefore description thereof will be omitted.

[0045] The first connecting member 50 and the second connecting member 60 are both formed in a cylindrical shape along the axis X. Of the first connecting member 50 and the second connecting member 60, the first connecting member 50 is arranged on the X1 side of the tool holder 1, and the second connecting member 60 is arranged on the X2 side of the tool holder 1.

[0046] The first connecting member 50 is configured to have a large diameter portion 51 provided on the central side in the axial X direction, a first small diameter portion 52 provided on the X1 side in the axial X direction, and a second small diameter portion 53 provided on the X2 side in the axial X direction. The small diameter portions 52, 53 each have an outer periphery that is male threaded. Specifically, the first small diameter portion 52 has a right-handed first male thread portion 54 provided on its outer periphery when viewed in the X1 direction, and the first male thread portion 54 is screwed into the female thread portion 35 of the collet 30. In other words, the cylindrical first connecting member 50 is disposed on the X2 side in the axial X direction with respect to the collet 30 and is connected to the collet 30. The second small diameter portion 53 has a right-handed second male thread portion 55 provided on its outer periphery when viewed in the X2 direction, and is screwed into the female thread portion 64 provided on the second connecting member 60 (described later).

[0047] The second connecting member 60 has a large diameter portion 61 provided on the X2 side in the axial X direction and a small diameter portion 62 provided on the X1 side in the axial X direction. When viewed in the X1 direction, the large diameter portion 61 has a right-handed male thread portion 63 provided on the outer periphery, which is screwed into a female thread portion 16 provided in the internal space 13 of the holder body 10. The small diameter portion 62 has a female thread portion 64 provided on the inner periphery, which is screwed into a second male thread portion 55 of the first connecting member 50. In this embodiment, as shown in FIG. 5 , the thread diameter (outer diameter) W3 of the male thread portion 63 of the second connecting member 60 is larger than the thread diameter (outer diameter) W1 of the first male thread portion 54 of the first connecting member 50 and the thread diameter (outer diameter) W2 of the second male thread portion 55. At the end of the large diameter portion 61 on the X2 side, a hole portion 65 (for example, a hexagonal hole) is formed for rotation operation by a rotation operation tool R (see FIG. 7).

[0048] The first connecting member 50 has a through hole 56 along the axis X. The through hole 56 has a first through hole 56a on the X1 side and a second through hole 56b on the X2 side. The first through hole 56a is formed with a larger diameter than the second through hole 56b. The X1 side end of the first through hole 56a is formed with a hole portion 57 (e.g., a hexagonal hole) with which the tip of a rotation operating tool R (e.g., a hexagonal wrench) can engage. The X2 side end of the second through hole 56b is also formed with a hole portion 58 (e.g., a hexagonal hole) with which the tip of a rotation operating tool R (e.g., a hexagonal wrench) can engage.

[0049] [Mounting of collet and connecting member] The first connecting member 50 is attached to the collet 30, and the second connecting member 60 is assembled to the inner surface of the holder body 10. The first connecting member 50 is attached to the collet 30 by screwing the small diameter portion 52 (first male thread portion 54) of the first connecting member 50 into the female thread portion 35 of the collet 30. The second connecting member 60 is assembled to the inner surface of the holder body 10 by inserting the second connecting member 60 into the holder body 10 from the X2 side, and screwing the large diameter portion 61 (male thread portion 63) into the female thread portion 16 on the inner surface of the tool holder 1.

[0050] Next, in the internal space 13 of the holder body 10, the collet 30 connected to the first connecting member 50 is assembled to the second connecting member 60. Specifically, the second external thread portion 55 of the first connecting member 50 is screwed into the internal thread portion 64 of the second connecting member 60. In this way, the collet 30 and the connecting member 40 (the first connecting member 50 and the second connecting member 60) are integrally attached to the internal space 13 of the tool holder 1. The subsequent attachment mode of the tool T to the tool holder 1 is the same as in the first embodiment.

[0051] According to this embodiment, the connecting member 40 is made up of the first connecting member 50 and the second connecting member 60, so when assembling the collet 30 to the holder body 10, the position of the collet 30 in the X direction can be easily adjusted by the connecting member 40. In addition, by preparing a plurality of first connecting members 50 and a plurality of second connecting members 60, it is also possible to easily configure connecting members 40 that fit various inner surface shapes of the tool holder 1.

[0052] Furthermore, according to this embodiment, the collet 30 has the female thread portion 35, the first connecting member 50 has the male thread portions 54, 55 on both sides in the X direction, and the second connecting member 60 has the female thread portion 64 and the male thread portion 63 on both sides in the X direction, so that the connecting member 40 can reliably connect the first connecting member 50 to the collet 30 while reliably assembling the second connecting member 60 to the inner surface of the holder main body 10. Furthermore, the thread diameter (outer diameter) W3 of the male thread portion 63 of the second connecting member 60 is larger than the thread diameters (outer diameters) W1, W2 of the two male thread portions 54, 55 of the first connecting member 50, so that the connecting member 40 can be stably fixed to the inner surface of the tool holder 1. As a result, in the tool holder 1, the collet 30 connected to the connecting member 40 can be stably held in an orientation along the axis X.

[0053] [Tool removal method 1] In this embodiment, if the tool T is not broken and the tool T can be rotated when the diameter reduction by the fastening ring 5 is released from the chuck portion 12, the reverse operations of the operations shown in the above-described mounting mode are sequentially performed. This allows the tool T to be removed from the tool holder 1.

[0054] [Tool removal method 2] On the other hand, if the tool T breaks during cutting, for example, and the remaining tool T only protrudes a short distance from the collet 30, the tool T can be removed from the tool holder 1 by using the method described below. In this embodiment, the right-handed male thread portion 63 of the second connecting member 60 and the right-handed second male thread portion 55 of the first connecting member 50 are configured to have different thread pitches. Specifically, as shown in FIGS. 5 and 7 , the thread pitch P2 of the male thread portion 63 of the second connecting member 60 is configured to be larger than the thread pitch P1 of the second male thread portion 55 of the first connecting member 50. If the thread pitch P1 and the thread pitch P2 are the same, when the second connecting member 60 is rotated rightward (clockwise) as viewed in the X1 direction, the first connecting member 50 and the second connecting member 60 rotate relative to each other, and therefore the movement distance of the second connecting member 60 toward the X1 side and the movement distance of the first connecting member 50 toward the X2 side are the same. Therefore, even if the second connecting member 60 is rotated rightward (clockwise), a state may occur in which the first connecting member 50 does not move toward the X1 side.

[0055] On the other hand, in this embodiment, after releasing the diameter reduction by the fastening ring 5, as shown in FIG. 7 , when the second connecting member 60 is rotated rightward (clockwise) using, for example, the rotation operating tool R as viewed in the X1 direction, the distance the second connecting member 60 moves toward the X1 side per rotation of the second connecting member 60 becomes greater than the distance the first connecting member 50 moves toward the X2 side due to the screw fastening of the second male threaded portion 55 and the female threaded portion 64. Therefore, by rotating the second connecting member 60, the first connecting member 50 can be moved toward the X1 side. That is, by rotating the second connecting member 60, the first connecting member 50 is moved toward the X1 side by the pitch difference between the thread pitch P2 of the male threaded portion 63 of the second connecting member 60 and the thread pitch P1 of the second male threaded portion 55 of the first connecting member 50, and the collet 30 is pushed along the axial center X direction, whereby the tool T is extracted together with the collet 30 from the chuck portion 12. In this embodiment, each time the second connecting member 60 rotates once clockwise, the collet 30 and the first connecting member 50 are pushed out toward the X1 side of the tool holder 1 by the difference (pitch difference) between the thread pitch P1 and the thread pitch P2.

[0056] As a specific example, the case will be shown where the thread pitch P1 of the second male thread portion 55 is 1.00 mm and the thread pitch P2 of the male thread portion 63 is 1.25 mm. In this case, each time the second connecting member 60 rotates once clockwise, the first connecting member 50 moves toward the collet 30 by 0.25 mm, which is the difference (pitch difference) between the thread pitch P1 and the thread pitch P2, and the tool T is pushed out toward the X1 side of the tool holder 1 together with the collet 30 and the first connecting member 50. This allows the tool T to be removed from the tool holder 1 efficiently.

[0057] Specifically, the tool T can be removed from the tool holder 1 by rotating the second connecting member 60 once or several times to move the first connecting member 50 toward the X1 side, and then rotating the first connecting member 50, thereby separating the tool T, collet 30, and first connecting member 50 from the holder body 10. This is an effective method when the degree of contact between the collet 30 and the holder body 10 changes when the tool T attached to the tool holder 1 breaks, making it difficult to rotate the rotation operating device R relative to the hole 58 of the first connecting member 50.

[0058] In addition, the tool T, collet 30 and first connecting member 50 may be detached from the holder body 10 by rotating the hole portion 58 of the first connecting member 50 with the rotation operating device R, as in the first embodiment, without operating the second connecting member 60, or by rotating the second connecting member 60 to the maximum extent toward the X1 side.

[0059] Third Embodiment As shown in FIGS. 8 to 10, in the third embodiment, as in the second embodiment, the connecting member 40 is made up of two connecting members (a first connecting member 50 and a second connecting member 70). However, the second connecting member 70 in the third embodiment has a different configuration from the second connecting member 60 in the second embodiment. The configuration other than the connecting member 40 is the same as in the first embodiment, so a description thereof will be omitted. Furthermore, the first connecting member 50 is the same as in the second embodiment, so a description thereof will be omitted.

[0060] The second connecting member 70 has a large diameter portion 71 provided on the X1 side of the axial core X direction and a small diameter portion 72 provided on the X2 side of the axial core X direction. When viewed in the X1 direction, the large diameter portion 71 has a right-handed male thread portion 73 provided on the outer periphery and a female thread portion 74 provided on the inner periphery. The male thread portion 73 is screwed into a female thread portion 16 provided on the X2 side of the internal space 13 of the holder body 10. The female thread portion 74 is screwed into a second male thread portion 55 of the first connecting member 50. In this embodiment, as shown in FIG. 8 , the thread diameter (outer diameter) W4 of the male thread portion 73 of the second connecting member 70 is larger than the thread diameter (outer diameter) W1 of the first male thread portion 54 of the first connecting member 50 and the thread diameter (outer diameter) W2 of the second male thread portion 55. At the end of the small diameter portion 72 on the X2 side, a hole portion 75 (for example, a hexagonal hole) is formed for rotation operation using a rotation operation tool R (see FIG. 10).

[0061] [Mounting of collet and connecting member] The first connecting member 50 is attached to the collet 30, and the second connecting member 70 is assembled to the internal space 13 (inner surface) of the holder body 10. The attachment of the first connecting member 50 to the collet 30 is the same as in the second embodiment. To assemble the second connecting member 70 to the inner surface of the holder body 10, the second connecting member 70 is inserted into the holder body 10 from the base end side, and the large diameter portion 71 (male thread portion 73) is screwed into the female thread portion 16 formed on the X2 side of the internal space 13 of the holder body 10.

[0062] Next, in the internal space 13 of the holder body 10, the collet 30 connected to the first connecting member 50 is assembled to the second connecting member 70. Specifically, the second male thread portion 55 of the first connecting member 50 is screwed into the female thread portion 74 of the second connecting member 70. In this way, the collet 30 and the connecting member 40 (the first connecting member 50 and the second connecting member 70) are integrally attached to the internal space 13 of the holder body 10. The subsequent attachment mode of the tool T to the tool holder 1 is the same as in the first embodiment.

[0063] [Tool removal method 1] In the third embodiment, if the tool T is not broken and the tool T can be rotated when the diameter reduction by the fastening ring 5 is released from the chuck portion 12, the reverse operations of the operations shown in the above-described mounting mode are sequentially performed. This allows the tool T to be removed from the tool holder 1.

[0064] [Tool removal method 2] On the other hand, if the tool T breaks during cutting, for example, and the remaining tool T only protrudes a short distance from the collet 30, the tool T can be removed from the tool holder 1 by using the method described below. In this embodiment, as in the second embodiment, the male thread portion 73 of the second connecting member 70 and the second male thread portion 55 of the first connecting member 50 have different thread pitches. However, in this embodiment, the relationship between the thread pitches differs from that in the second embodiment. Specifically, as shown in FIGS. 8 and 10 , the thread pitch P3 of the male thread portion 73 of the second connecting member 70 is smaller than the thread pitch P1 of the second male thread portion 55 of the first connecting member. In this case, the second connecting member 70 is rotated so as to move from the X2 side of the tool holder 1 toward the X2 side of the tool holder 1.

[0065] Specifically, after releasing the diameter reduction by the fastening ring 5, as shown in FIG. 10 , the second connecting member 70 is rotated leftward (counterclockwise) when viewed in the X1 direction, for example, using the rotation operating tool R. In this way, when the second connecting member 70 rotates once, the movement distance of the first connecting member 50 toward the X1 side becomes greater than the movement distance of the second connecting member 70 toward the X2 side. Therefore, by rotating the second connecting member 70, the first connecting member 50 can be moved toward the X1 side. That is, by rotating the second connecting member 70, the first connecting member 50 is moved toward the X1 side by the pitch difference between the thread pitch P3 of the male thread portion 73 of the second connecting member 70 and the thread pitch P1 of the second male thread portion 55 of the first connecting member 50, and the collet 30 is pushed along the axial center X direction, whereby the tool T is extracted together with the collet 30 from the chuck portion 12. In this embodiment, each time the second connecting member 70 is rotated once left (counterclockwise), the collet 30 and the first connecting member 50 are pushed out by an amount equal to the difference between the thread pitch P1 and the thread pitch P3.

[0066] As a specific example, the case will be shown where the thread pitch P1 of the second male thread portion 55 is 1.25 mm and the thread pitch P3 of the male thread portion 73 is 1.00 mm. In this case, each time the second connecting member 70 rotates left (counterclockwise), the first connecting member 50 moves toward the collet 30 by 0.25 mm, which is the difference between the thread pitch P1 and the thread pitch P3, and the tool T is pushed out together with the collet 30 toward the X1 side of the tool holder 1. This allows the tool T to be removed from the tool holder 1 efficiently.

[0067] In this embodiment, too, the tool T can be specifically removed from the tool holder 1 by rotating the second connecting member 70 once or several times to move the first connecting member 50 toward the X1 side, and then rotating the first connecting member 50, thereby detaching the tool T, collet 30, and first connecting member 50 from the holder body 10.

[0068] In this embodiment, too, the tool T, collet 30 and first connecting member 50 may be detached from the holder body 10 by not operating the second connecting member 70, or by operating the second connecting member 70 to the maximum extent toward the X2 side, and then rotating the hole portion 58 of the first connecting member 50 with the rotation operating device R, as in the first embodiment.

[0069] Other Embodiments (1) In the above embodiment, an example was shown in which the fitting member 20 installed on the tool T and the fitting hole portion B of the collet 30 were used as a configuration for preventing the tool T from rotating or coming off relative to the tool holder 1, but other configurations may also be used.

[0070] (2) In the second embodiment described above, an example was shown in which the thread pitch P2 of the male thread portion 63 of the second connecting member 60 was larger than the thread pitch P1 of the second male thread portion 55 of the first connecting member. Alternatively, in the connecting member 40, the thread pitch P2 of the male thread portion 63 of the second connecting member 60 and the thread pitch P1 of the second male thread portion 55 of the first connecting member 50 may be the same. However, in this case, as described above, the first connecting member 50 can be moved toward the X1 side by rotating the first connecting member 50 after the first connecting member 50 has entered a state in which it is no longer rotating relative to the second connecting member 60. [Industrial Applicability]

[0071] The present invention is widely applicable to tool holding structures and tool removal methods. [Explanation of symbols]

[0072] 1: Tool holder 2: Shank 12: Chuck part 13: Interior space 16: Female thread 30: Colette 30a: Outer periphery 35: Female thread 40: Connecting member 44: First male thread 45: Second male thread 50: First connecting member 54: First male thread 55: Second male thread 60, 70: Second connecting member 63,73: Male thread 64,74: Female thread P1, P2, P3: Thread pitch T:Tool (cutting tool) W1, W2, W3, W4: Thread diameter X: Shaft center (rotation axis center)

Claims

1. The cutting tool is held by a cylindrical tool holder that rotates around a rotation axis. The tool holder comprises: a chuck portion provided on one side in the direction of the rotation axis and capable of receiving a shank portion of the cutting tool; a collet that holds the shank of the cutting tool and is inserted into the chuck to be held coaxially with the rotation axis; a cylindrical connecting member that is disposed on the other side of the collet in the rotation axis direction and is connected to the collet, The connecting member is detachably attached to the inner surface of the tool holder, and the connecting member can be moved toward the one side by operating the connecting member from the other side in the rotation axis direction of the tool holder to push the collet along the rotation axis direction, thereby enabling the cutting tool to be removed from the chuck portion together with the collet.

2. The connecting member has a first connecting member arranged on the one side and a second connecting member arranged on the other side, The first connecting member is configured to be connectable to the collet, The tool holding structure according to claim 1 , wherein the second connecting member is connectable to the first connecting member and is configured to be detachably attached to the inner surface of the tool holder.

3. The collet has a female thread portion provided on the other side, the second connecting member has a female threaded portion provided on the one side and a male threaded portion that can be screwed into a female threaded portion provided on an inner surface of the tool holder, The first connecting member has a first male threaded portion that can be screwed into the female threaded portion of the collet, and a second male threaded portion that can be screwed into the female threaded portion of the second connecting member, The tool holding structure according to claim 2 , wherein a thread diameter of the male threaded portion of the second connecting member is larger than a thread diameter of the first male threaded portion of the first connecting member and a thread diameter of the second male threaded portion of the first connecting member.

4. The collet has a female thread portion provided on the other side, the second connecting member has a female threaded portion provided on the one side and a male threaded portion that can be screwed into a female threaded portion provided on an inner surface of the tool holder, The first connecting member has a first male threaded portion that can be screwed into the female threaded portion of the collet, and a second male threaded portion that can be screwed into the female threaded portion of the second connecting member, The tool holding structure according to claim 2 or 3, wherein a thread pitch of the male threaded portion of the second connecting member is different from a thread pitch of the second male threaded portion of the first connecting member.

5. A method for removing a cutting tool held in a tool holder from the tool holder, comprising the steps of: a cylindrical tool holder that holds the cutting tool and rotates around a rotation axis; The tool holder comprises: a chuck portion provided on one side in the direction of the rotation axis and capable of receiving a shank portion of the cutting tool; a collet that holds the shank of the cutting tool and is inserted into the chuck to be held coaxially with the rotation axis; a cylindrical connecting member that is disposed on the other side of the collet in the rotation axis direction and is connected to the collet, a tool removal method for removing the cutting tool together with the collet from the chuck portion by operating the connecting member from the other side of the rotation axis direction of the tool holder and moving the connecting member toward the one side to push the collet along the rotation axis direction of the tool holder.

6. A method for removing a cutting tool held in a tool holder from the tool holder, comprising the steps of: a cylindrical tool holder that holds the cutting tool and rotates around a rotation axis; The tool holder comprises: a chuck portion provided on one side in the direction of the rotation axis and capable of receiving a shank portion of the cutting tool; a collet that holds the shank of the cutting tool and is inserted into the chuck to be held coaxially with the rotation axis; a cylindrical connecting member that is disposed on the other side of the collet in the rotation axis direction and is connected to the collet, the connecting member has a first connecting member arranged on the one side and a second connecting member arranged on the other side in the rotation axis direction, The first connecting member is configured to be connectable to the collet, the second connecting member is connectable to the first connecting member and is configured to be attachable / detachable to the inner surface of the tool holder, The collet has a female thread portion on the other side, the second connecting member has a female threaded portion provided on the one side and a male threaded portion that can be screwed into a female threaded portion provided on an inner surface of the tool holder, The first connecting member has a first male threaded portion that can be screwed into the female threaded portion of the collet, and a second male threaded portion that can be screwed into the female threaded portion of the second connecting member, The thread pitch of the male threaded portion of the second connecting member is configured to be different from the thread pitch of the second male threaded portion of the first connecting member, a tool removal method in which the cutting tool is removed from the chuck portion together with the collet by rotating the second connecting member to move the first connecting member toward the one side by an amount equal to the pitch difference between the thread pitch of the male threaded portion of the second connecting member and the thread pitch of the second male threaded portion of the first connecting member, thereby pushing the collet along the direction of the rotation axis of the tool holder.

Images