Tool holder and pull stud

Abstract

To remarkably reduce a burden of maintenance by excellently restraining intrusion of foreign matter into a tool holder including a pull stud, and to stably supply a coolant to a tool.SOLUTION: The tool holder includes a holder body holding the tool, and a pull stud fixed to the holder body and held by the machine tool, wherein the pull stud includes a through hole extending in an axial direction and communicating with a coolant passage formed in the holder body, and a filter disposed at an end portion of the through hole on a machine tool side, the filter allowing a coolant supplied from the machine tool side to flow into the through hole and restricting entry of foreign matter into the through hole.SELECTED DRAWING: Figure 1

Description

[Technical Field]

[0001] The present disclosure relates to a tool holder that holds a tool and is held by a machine tool, and a pull stud that is fixed to a holder body of the tool holder. [Background technology]

[0002] A known tool holder includes a holder body capable of holding a tool body, a pull stud attached to the holder body and held by a machine tool, and a filter disposed inside the holder body (see, for example, Patent Document 1). The pull stud has a coolant passage (through-hole) through which coolant flows and a female thread formed on the inner periphery of the coolant passage. The filter is formed on the outer periphery of a cylindrical peripheral wall and has a male thread formed thereon that screws into the female thread of the pull stud, an opening that opens to the peripheral wall on the pull stud side, a bottom portion located on the tool body side of the opening in the peripheral wall, and a plurality of small holes arranged at least in the peripheral wall along a direction from the opening to the bottom that filter and pass coolant supplied to the opening. This allows the filter to be detachably attached to the pull stud and interposed in a flow path that supplies coolant to the tool via the coolant passage of the pull stud. [Prior art documents] [Patent documents]

[0003] [Patent Document 1] Patent No. 6528586 Summary of the Invention [Problem to be solved by the invention]

[0004] When the conventional tool holder is transported by a tool changer or robot arm to change tools on a machine tool, foreign matter such as chips present around the machine tool may enter the coolant passage of the pull stud. In such cases, the foreign matter moves from the pull stud along with the coolant from the machine tool toward a filter inside the holder body, which prevents the foreign matter from flowing toward the tool. However, there is a limit to the amount of foreign matter that can accumulate within the peripheral wall of the filter. Therefore, to prevent the filter from clogging and restricting the supply of coolant to the tool, the foreign matter must be periodically removed. However, with the conventional tool holder, removing the filter from the holder body is time-consuming, increasing the number of steps required for machining using the machine tool. Furthermore, when changing tools, air is blown onto the pull stud of the tool holder to remove the foreign matter. However, with the tool holder, the air blown may actually promote the intrusion of foreign matter into the coolant passage of the pull stud.

[0005] Therefore, a primary object of the present disclosure is to effectively prevent foreign matter from entering a tool holder including a pull stud, thereby significantly reducing the maintenance burden and enabling a stable supply of coolant to a tool. [Means for solving the problem]

[0006] The tool holder disclosed herein includes a holder body that holds a tool, and a pull stud that is fixed to the holder body and held by a machine tool, wherein the pull stud includes a through hole that extends in the axial direction and communicates with a coolant passage formed in the holder body, and a filter that is arranged at the end of the through hole on the machine tool side, and that allows coolant supplied from the machine tool side to flow into the through hole and prevents foreign matter from entering the through hole.

[0007] The pull stud of the tool holder disclosed herein includes a through hole extending axially and communicating with a coolant passage formed in the holder body, and a filter. The filter is located at the machine tool side end of the through hole, allowing coolant supplied from the machine tool to flow into the through hole while preventing foreign matter from entering the through hole. This effectively prevents foreign matter, such as chips present around the machine tool, from entering the through hole of the pull stud and the coolant passage of the holder body when the tool holder is transported for tool replacement. Even if foreign matter adheres to the filter of the pull stud during tool holder transport, the movement of the tool holder associated with the transport makes it easy to shake the foreign matter off the filter, or the foreign matter can be blown away from the filter with an air blower. As a result, the intrusion of foreign matter into the tool holder, including the pull stud, and the accumulation (clogging) of foreign matter around the filter are effectively prevented, significantly reducing the burden of foreign matter removal (i.e., maintenance) and enabling a stable supply of coolant to the tool.

[0008] The pull stud disclosed herein is a pull stud that is fixed to a holder body of a tool holder that holds a tool and is held by a machine tool, and includes a through hole that extends axially and communicates with a coolant passage formed in the holder body, and a filter that is located at the end of the through hole on the machine tool side and allows coolant supplied from the machine tool side to flow into the through hole and prevents foreign matter from entering the through hole.

[0009] The pull stud disclosed herein effectively prevents foreign matter from entering the tool holder containing the pull stud and from accumulating (clogging) around the filter, significantly reducing the burden of removing foreign matter, i.e., the maintenance burden, and enabling a stable supply of coolant to the tool. [Brief explanation of the drawings]

[0010] [Figure 1] FIG. 1 is a schematic configuration diagram showing a tool holder according to the present disclosure. [Figure 2] FIG. 1 is a schematic diagram showing a pull stud included in a tool holder according to the present disclosure. [Figure 3] FIG. 10 is an enlarged perspective view showing a pull stud included in the tool holder of the present disclosure. [Figure 4] FIG. 10 is an enlarged perspective view showing another pull stud applicable to the tool holder of the present disclosure. DETAILED DESCRIPTION OF THE INVENTION

[0011] Next, embodiments of the present disclosure will be described with reference to the drawings.

[0012] FIG. 1 is a schematic diagram showing a tool holder 1 according to the present disclosure. The tool holder 1 shown in the figure is attached to a spindle (rotating shaft) 50 of a machine tool (not shown), such as a machining center included in an automated production line, to perform cutting (drilling, milling, threading, etc.) on a workpiece (base material) made of, for example, a metal material. The tool holder 1 is used in a wet environment where a coolant (cutting fluid) for cooling and cleaning is continuously supplied (sprayed) from the spindle 50 side (the upper side in FIG. 1 ) or the side. As shown in FIG. 1 , the tool holder 1 includes a holder body 2 that holds a tool 10, which is a milling tool (cutting tool) such as a drill, end mill, or tap, and a pull stud 3 that is fixed to the holder body 2 and held by the spindle 50, which is driven to rotate.

[0013] The holder body 2 includes a shank portion 21, a flange portion 22, and a tool holding portion 23. The shank portion 21 is tapered toward the spindle 50. The flange portion 22 is formed integrally with the shank portion 21 so as to be adjacent to the large-diameter end of the shank portion 21, and is held by a tool changer, robot arm, or the like (not shown) when replacing the tool 10 attached to the spindle 50. The tool holding portion 23 is formed integrally with the shank portion 21 and the flange portion 22 so as to be located on the opposite side of the flange portion 22 from the shank portion 21.

[0014] A chuck 24, such as a collet chuck, milling chuck, or hydraulic chuck, is disposed within the tool holding portion 23 for fixing the tool 10 to the tool holder 1 (holder body 2). Furthermore, a coolant passage 25 is formed in the holder body 2. The coolant passage 25 is a circular hole that extends in the axial direction of the holder body 2 along the central axis CL from the small-diameter end face (the upper end face in FIG. 1 ) of the shank portion 21 to the flange portion 22, and communicates with the coolant passage formed in the chuck 24 and the coolant passage formed in the tool 10.

[0015] The pull stud 3 is formed from a metal such as die steel, and as shown in FIG. 2, includes a fixed portion 31, a seal portion 32, a flange portion 33, and a clamped portion 34. The fixed portion 31 is formed at the base end (lower end in FIG. 3) of the pull stud 3 and has a male thread formed on its outer circumferential surface. The seal portion 32 is formed closer to the tip end (upper end in FIG. 3) of the pull stud 3 than the fixed portion 31 and has a seal ring groove into which a sealing member such as an O-ring (not shown) is attached. The flange portion 33 is formed closer to the tip end (upper end in FIG. 3) of the pull stud 3 than the seal portion 32 and has a larger outer diameter than the fixed portion 31 and seal portion 32. The clamped portion 34 is formed at the tip end (upper end in FIG. 3) of the pull stud 3 so that it can be gripped by a draw bar 55 (see FIG. 1) located inside the spindle 50 of the machine tool.

[0016] 1 and 2, the male threads on the fixing portion 31 of the pull stud 3 are threaded into the female threads 26 formed in the coolant passage 25 of the holder body 2, and the pull stud 3 is fixed to the holder body 2 so that the flange portion 33 and the clamped portion 34 are exposed to the outside from the small-diameter end of the shank portion 21 of the holder body 2. This makes it possible to grip the clamped portion 34 with the draw bar 55 inside the spindle 50 and pull the pull stud 3 toward the machine tool.

[0017] Furthermore, the pull stud 3 includes a through hole 35 and a filter 30. The through hole 35 is a circular hole centered on the axis a of the pull stud 3 and extends in the axial direction of the pull stud 3. When the pull stud 3 is secured to the holder body 2, the through hole 35 communicates with the coolant passage 25 of the holder body 2, as shown in FIG. 1. When the pull stud 3 is secured to the holder body 2, the gap between the pull stud 3 and the coolant passage 25 of the holder body 2 is sealed by a seal ring (not shown) attached to the seal portion 32 of the pull stud 3.

[0018] The filter 30 is a porous member made of a metal, such as chrome-molybdenum steel, that is softer than the metal forming the pull stud 3. As shown in FIGS. 2 and 3, the filter 30 has multiple holes (through holes) 30h that extend parallel to one another. Each hole 30h has an inner diameter of, for example, approximately 0.5 mm, and the total number of holes 30h is determined so that the total opening area of ​​the multiple holes 30h is as close as possible to the cross-sectional area of ​​the through hole 35, while still ensuring sufficient strength of the filter 30. The filter 30 is fitted into an expanded diameter portion 35e formed at the machine tool side end (the tip of the clamped portion 34) of the through hole 35 of the pull stud 3, so that the multiple holes 30h extend parallel to the axis a (axial direction) of the pull stud 3. In this embodiment, the filter 30 is press-fitted into the expanded diameter portion 35e, thereby securing it to the pull stud 3.

[0019] The tool holder 1 configured as described above is gripped by a tool changer or the like while holding the tool 10, and is transported to the target machine tool by the tool changer or the like. During this process, the filter 30 of the pull stud 3 of the tool holder 1 is located at the end of the through hole 35 facing the machine tool, i.e., at the tip of the clamped portion 34. This effectively prevents foreign matter, such as chips, present around the machine tool from entering the through hole 35 of the pull stud 3 and the coolant passage 25 of the holder body 2. Furthermore, by locating the filter 30 at the end of the through hole 35 facing the machine tool, even if foreign matter adheres to the filter 30 of the pull stud 3 during transport, the movement of the tool holder 1 during transport makes it easy to shake off the foreign matter from the filter 30. Furthermore, during tool changes, air is blown onto the pull stud 3 and other components of the tool holder 1 to remove the foreign matter. Therefore, even if foreign matter adheres to the filter 30 of the pull stud 3 during transport, the foreign matter can be blown off the filter 30 with the air blower. Therefore, tool holder 1 makes it possible to substantially prevent foreign matter from entering through hole 35 and coolant passage 25 or adhering to filter 30 during a tool change, thereby preventing pull stud 3 from being held by spindle 50 of the machine tool.

[0020] Furthermore, when cutting a workpiece using the tool 10 held by the tool holder 1, coolant is supplied from the machine tool (spindle 50) to the filter 30 of the pull stud 3. Furthermore, the filter 30 allows the coolant supplied from the machine tool to flow into the through-hole 35 while preventing foreign matter from entering the through-hole 35. The coolant that flows into the through-hole 35 flows into the coolant passage 25 of the holder body 2 and is supplied to the tip of the tool 10, i.e., the cutting point of the cutting edge of the tool 10, via the coolant passages formed in the chuck 24 and the tool 10. This effectively prevents foreign matter from getting caught in the tool 10, even if foreign matter adheres to the filter 30 or gets mixed in the coolant from the machine tool. Furthermore, the tool holder 1 makes it possible to substantially prevent foreign matter from entering the area around the filter 30, the through hole 35, and the coolant passage 25 during a tool change, thereby effectively suppressing the accumulation (clogging) of foreign matter around the filter 30 and significantly reducing the burden of removing foreign matter, i.e., the burden of maintenance, while enabling a stable supply of coolant to the tool 10.

[0021] As described above, the tool holder 1 includes the holder body 2 that holds the tool 10, and the pull stud 3 of the present disclosure that is fixed to the holder body 2 and held by the spindle 50 of the machine tool. The pull stud 3 also includes a through hole 35 that extends axially and communicates with a coolant passage 25 formed in the holder body 2, and a filter 30. The filter 30 is disposed in an expanded diameter portion 35e formed at the end of the through hole 35 on the machine tool side, and includes a filter 30 that allows coolant supplied from the machine tool side to flow into the through hole 35 and prevents foreign matter from entering the through hole 35.

[0022] This makes it possible to extremely effectively prevent foreign matter, such as chips, present around the machine tool from entering the through-hole 35 of the pull stud 3 and the coolant passage 25 of the holder body 2 when the tool holder 1 is transported to replace the tool 10 of the machine tool. Furthermore, even if foreign matter adheres to the filter 30 of the pull stud 3 when the tool holder 1 is transported, the movement of the tool holder 1 associated with the transport makes it easy to shake the foreign matter off the filter 30, or the foreign matter can be blown away from the filter 30 with an air blower. Therefore, the tool holder 1 effectively prevents foreign matter from entering the tool holder 1, including the pull stud 3, and from accumulating (clogging) around the filter 30, significantly reducing the burden of removing foreign matter, i.e., the maintenance burden, and enabling a stable supply of coolant to the tool 10.

[0023] Furthermore, in the above-described tool holder 1, a porous member is used as the filter 30, which has a plurality of holes 30h each extending in the axial direction of the pull stud 3 and is fitted into the end (expanded diameter portion 35e) of the through hole 35 on the machine tool side.

[0024] This prevents an increase in the manufacturing costs of the filter 30 and therefore the pull stud 3, and also ensures a sufficient total opening area of ​​the multiple holes 30h of the filter (porous member) 30, enabling a stable supply of coolant to the tool 10.

[0025] 4 is an enlarged perspective view showing another pull stud 3B that can be applied to the tool holder 1 of the present disclosure. Note that, among the components of the pull stud 3B, the same elements as those of the pull stud 3 described above are given the same reference numerals, and redundant explanations will be omitted.

[0026] 4 includes multiple radial holes 34h spaced apart (equally spaced) in the circumferential direction at the end of the pull stud 3B facing the machine tool, i.e., at the tip of the clamped portion 34. Each radial hole 34h opens on the outer peripheral surface of the tip of the clamped portion 34 and extends radially through the pull stud 3B to communicate with a through-hole 35. This reduces the number of holes 30h, ensuring good strength for the filter (porous member) 30B, while also ensuring a sufficient total opening area for the multiple holes 30h and multiple radial holes 34h in the filter 30B, enabling a stable supply of coolant to the tool 10.

[0027] It should be noted that the invention of the present disclosure is not limited to the above-described embodiment, and various modifications can be made within the scope of the present disclosure. Furthermore, the above-described embodiment is merely one specific form of the invention described in the Summary of the Invention section, and does not limit the elements of the invention described in the Summary of the Invention section. [Industrial Applicability]

[0028] The invention of the present disclosure can be used in industries such as the manufacturing of tool holders and pull studs. [Explanation of symbols]

[0029] 1 tool holder, 2 holder body, 25 coolant passage, 3,3B pull stud, 30 filter (porous member), 30h hole, 34h radial hole, 35 through hole, 35e enlarged portion, 10 tool, 50 spindle.

Claims

1. A tool holder including a holder body that holds a tool, and a pull stud that is fixed to the holder body and is held by a machine tool, The pull stud is a through hole extending in the axial direction and communicating with a coolant passage formed in the holder body; a filter disposed at an end of the through hole on the machine tool side, the filter allowing coolant supplied from the machine tool side to flow into the through hole and restricting foreign matter from entering the through hole; A tool holder comprising:

2. 2. The tool holder according to claim 1, The filter includes a tool holder, which is a porous member having a plurality of holes each extending in the axial direction and is fitted into the end of the through hole on the machine tool side.

3. 3. The tool holder according to claim 2, The pull stud is a tool holder including a plurality of radial holes that open on the outer peripheral surface of the end portion facing the machine tool and communicate with the through hole.

4. A pull stud is fixed to a holder body of a tool holder that holds a tool and is held by a machine tool, a through hole extending in the axial direction and communicating with a coolant passage formed in the holder body; a filter disposed at an end of the through hole on the machine tool side, the filter allowing coolant supplied from the machine tool side to flow into the through hole and preventing foreign matter from entering the through hole; A pull stud is provided.

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