Grooving tool

Abstract

To make it possible to eject a coolant accurately near a cutting blade.SOLUTION: A grooving tool comprises a cutting insert, a holder 3, and a coolant channel 4. The holder 3 has an insert attachment seat 35, and jaw parts 36 which are located above and below the insert attachment seat 35, and fix the cutting insert. The jaw part 36 has a curved shape when viewed from a tool tip side, and becomes thinner as separating from the insert attachment seat 35. The coolant channel 4 has a jaw part channel 43 which extends in the jaw part 36. The jaw part channel 43 has: a vertically long guide channel part 44 having dimension in a vertical direction compared to dimension in a tool width direction in a channel cross section; and a laterally long ejection channel part 45 having dimension in the tool width direction compared to dimension in the vertical direction in a channel cross section.SELECTED DRAWING: Figure 4A

Description

Technical Field

[0001] The present invention relates to a grooving tool. This application claims priority based on Japanese Patent Application No. 2020-145526 filed in Japan on August 31, 2020, the content of which is incorporated herein by reference.

Background Art

[0002] A grooving tool for performing grooving on the end face or circumferential face of a workpiece to be machined is known. The grooving tool includes a cutting insert having a cutting edge, a holder for holding the cutting insert, and a coolant passage extending inside the holder. The holder has an insert mounting seat on which the cutting insert is disposed, and a pair of jaws disposed above and below the insert mounting seat and contacting the cutting insert from above and below in the vertical direction. As a conventional grooving tool, for example, the one described in Patent Document 1 is well known.

Prior Art Documents

Patent Documents

[0003]

Patent Document 1

Summary of the Invention

Problems to be Solved by the Invention

[0004] For example, in a grooving tool for end face grooving or the like, the jaws may be formed in a curved shape when viewed from the tool tip side. In this case, the plate thickness of the jaws becomes thinner as they move away from the insert mounting seat in the vertical direction. In such a grooving tool, it is difficult to provide a coolant passage having a desired shape inside the jaws.

[0005] For example, when attempting to supply coolant near the cutting edge through the relief surface of a cutting insert, it is necessary to incline the coolant flow path within the jaw portion upward at an angle as it approaches the tool tip side so that the vicinity of the jet outlet of the coolant flow path has an inclination close to the relief surface. However, due to various restrictions imposed by thin portions of the jaw thickness or curved shapes, problems arise such as having to reduce the cross-sectional area of the coolant flow path or being unable to sufficiently incline the coolant flow path.

[0006] That is, when trying to accurately jet the coolant near the cutting edge by passing the coolant flow path through a thin portion of the jaw thickness, the cross-sectional area of the coolant flow path has to be reduced, resulting in a decrease in the coolant flow rate. Also, when trying to ensure a large cross-sectional area of the coolant flow path by passing the coolant flow path through a thick portion of the jaw thickness, it becomes difficult to incline the coolant flow path near the jet outlet, and the coolant cannot be accurately jetted near the cutting edge.

[0007] One object of the present invention is to provide a grooving tool that can accurately jet coolant near the cutting edge while ensuring the coolant flow rate.

Means for Solving the Problem

[0008] One aspect of the grooving tool of the present invention includes a cutting insert having a cutting edge, a holder for holding the cutting insert, and a coolant flow path extending inside the holder. The cutting edge has a cutting edge portion extending in the tool width direction, and the holder has an insert mounting seat on which the cutting insert is disposed, and a pair of jaws disposed above and below the insert mounting seat, and these jaws contact the cutting insert from above and below. At least one of the jaws is plate-shaped and extends in a curved shape when viewed from the tool tip side, and the plate thickness becomes thinner as it moves away from the insert mounting seat in the vertical direction. The coolant flow path has a jaw flow path extending inside the at least one jaw. The jaw flow path has a vertically long guide flow path portion whose cross-section of the flow path has a larger vertical dimension than the dimension in the tool width direction, and a jet flow path portion communicating with the guide flow path portion. The jet flow path portion is disposed closer to the insert mounting seat in the tool tip side and in the vertical direction than the guide flow path portion, and opens at the tool tip side end of the jaw. The jet flow path portion has a horizontally long cross-section of the flow path, and the dimension in the tool width direction is larger than the vertical dimension. In this specification, the "cross-section" of the guide flow path portion and the jet flow path portion both indicates a cross-section appearing in a virtual plane perpendicular to the axial direction of the holder.

[0009] According to the grooving tool of the above aspect, even if the jaw for clamping the cutting insert is a curved plate shape whose plate thickness becomes thinner as it moves away from the insert mounting seat in the vertical direction, the coolant can be accurately and stably ejected from the jaw flow path extending inside the jaw toward the vicinity of the cutting edge.

[0010] Specifically, among the jaw flow paths, since the cross-section of the jet flow path portion that opens at the tool tip side end of the jaw is horizontally long with a larger dimension in the tool width direction than the vertical dimension, this jet flow path portion is disposed in the portion of the jaw where the plate thickness is thick, that is, the portion close to the insert mounting seat, and the coolant can be stably ejected over a wide range from the jet flow path portion to the entire cutting edge including at least the cutting edge portion.

[0011] In addition, since the channel cross-section of the guide channel portion among the jaw channels has a vertically long shape in which the dimension in the vertical direction is larger than the dimension in the tool width direction, it becomes possible to arrange this guide channel portion in a thin-walled portion (thin wall part) of the jaw that is vertically separated from the insert mounting seat among the jaws. That is, while ensuring a large channel cross-sectional area of the guide channel portion, that is, while ensuring the flow rate of the coolant ejected from the jaws, this guide channel portion can be arranged in the thin-walled portion of the jaws. Therefore, it is easy to incline the channel shape from the guide channel portion to the ejection channel portion at an angle in the vertical direction as it goes toward the tool tip side. For this reason, it becomes easy to arrange the cutting edge near the extension line of the opening (ejection port) of the ejection channel portion, and the coolant can be accurately and efficiently supplied near the cutting edge.

[0012] In the grooving tool, the jaw channels may be provided in each of the jaws.

[0013] In this case, among the pair of jaws, coolant can be ejected from the jaw channel of the upper jaw portion arranged above the insert mounting seat through the rake face of the cutting insert near the cutting edge. Also, among the pair of jaws, coolant can be ejected from the jaw channel of the lower jaw portion arranged below the insert mounting seat through the flank face of the cutting insert near the cutting edge. For this reason, coolant can be supplied more stably near the cutting edge.

[0014] In the grooving tool, the channel cross-sectional area of the ejection channel portion may be smaller than the channel cross-sectional area of the guide channel portion. In the grooving tool, the channel cross-sectional area of the guide channel portion and the channel cross-sectional area of the ejection channel portion may be the same as each other.

[0015] For example, different from the above configuration, if the channel cross-sectional area of the ejection channel portion is larger than the channel cross-sectional area of the guide channel portion, when the coolant flows from the guide channel portion into the ejection channel portion, a decrease in flow velocity, pressure loss, etc. may occur due to the increase in the channel cross-sectional area. On the one hand, according to any of the above configurations, when the coolant flows from the guide channel portion into the ejection channel portion, a decrease in flow velocity, pressure loss, etc. can be suppressed. The flow velocity of the coolant flowing through the ejection channel portion is stably increased, and the vicinity of the cutting edge can be efficiently cooled by the coolant ejected from the ejection channel portion.

[0016] In the grooving tool, the maximum value of the ratio (a / b) of the dimension (a) in the vertical direction to the dimension (b) in the tool width direction in the flow path cross-section of the guide channel portion may be 1.2 or more and 5.0 or less. Also, the ratio (a / b) of the guide channel portion may be decreased as it goes toward the tool tip side.

[0017] In the flow path cross-section of the guide channel portion, when the maximum value of the ratio (a / b) of the dimension (a) in the vertical direction to the dimension (b) in the tool width direction is 1.2 or more, the flow path cross-section of the guide channel portion stably becomes a vertically long shape, and it is easy to arrange this guide channel portion in the thin-walled portion of the jaw portion. For this reason, the operational effects of the present invention described above can be obtained more stably. Also, when the maximum value of the ratio (a / b) is 5.0 or less, problems such as an increase in pressure loss due to the cross-sectional shape of the flow path being too vertically long and flat can be suppressed. Furthermore, when the ratio (a / b) of the guide channel portion is decreased as it goes toward the tool tip side, since the change in the cross-sectional shape of the guide channel portion is smooth, the flow path resistance of the guide channel portion can be kept small.

[0018] In the grooving tool, the flow path cross-section of the ejection channel portion may have a maximum value of the ratio (b / a) of the dimension (b) in the tool width direction to the dimension (a) in the vertical direction of 1.2 or more and 5.0 or less. Also, the ratio (b / a) of the ejection channel portion may be increased as it goes toward the tool tip side.

[0019] In the cross-section of the ejection channel portion, when the maximum value of the ratio (b / a) of the dimension (b) in the tool width direction to the dimension (a) in the vertical direction is 1.2 or more, the cross-section of the ejection channel portion stably becomes horizontally long, and coolant can be stably ejected from this ejection channel portion over the entire cutting edge area. Therefore, the operation and effect of the present invention described above can be obtained more stably. Also, when the maximum value of the ratio (b / a) is 5.0 or less, since the shape of the cross-section of the channel is too horizontally long and flat, problems such as the coolant being ejected in a mist form can be suppressed, and the problem of the coolant being wasted and dissipated to parts other than the cutting edge can be suppressed. Furthermore, when the ratio (b / a) of the ejection channel portion increases as it goes toward the tool tip side, since the change in the cross-sectional shape of the ejection channel portion is smooth, the flow resistance of the ejection channel portion can be kept small.

[0020] In the grooving tool, the cross-sections of the respective channels of the guide channel portion and the ejection channel portion may be elliptical.

[0021] In the grooving tool, the cross-sections of the respective channels of the guide channel portion and the ejection channel portion may be polygonal, such as triangular, quadrilateral, pentagonal, or hexagonal.

Effect of the Invention

[0022] According to the grooving tool of the above aspect of the present invention, while ensuring the coolant flow rate, the coolant can be accurately ejected near the cutting edge.

Brief Description of the Drawings

[0023]

Figure 1

Figure 2

Figure 3

Figure 4A

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Figure 5B

Figure 6A

Figure 6B

Figure 7A

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Figure 8A

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Figure 9

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Figure 11A

Figure 11B

Figure 12A

Figure 12B

Figure 13A

Figure 13B

Mode for Carrying Out the Invention

[0024] A grooving tool 1 according to an embodiment of the present invention will be described with reference to the drawings. The grooving tool 1 of this embodiment is a cutting tool used for turning operations such as grooving and parting. The grooving tool 1 is detachably mounted on a tool post or the like of a machine tool such as a lathe (not shown). Specifically, the grooving tool 1 of this embodiment is a tip-exchangeable grooving tool for end face grooving.

[0025] As shown in FIGS. 1 and 2, the grooving tool 1 includes an elongated rectangular cutting insert 2 having a cutting edge 21 at its tip, and a holder 3 that holds the cutting insert 2. The holder 3 includes a rectangular bar-shaped shank portion 31 that is attached to a tool post or the like, a head member 32 that sandwiches and fixes the cutting insert 2, a coolant passage 4 that extends inside the holder 3 and supplies coolant to the cutting edge 21, and fixing screws 8 and fastening screws 11 for fixing the head member 32 to the shank portion 31. The head member 32 is detachably attached to the first end portion 31a of the two end portions (the first end portion 31a and the second end portion 31b) of the shank portion 31, and holds the cutting insert 2 such that the cutting edge 21 protrudes from the first end portion 31a.

[0026] 〔Definition of directions〕 In this embodiment, an XYZ orthogonal coordinate system is set to describe each component. The X-axis direction is the direction in which the central axis of the shank portion 31 extends, that is, the direction in which the holder 3 extends, and corresponds to the axial direction (longitudinal direction) of the grooving tool 1. Among the axial directions, the direction from the second end portion 31b of the shank portion 31 toward the first end portion 31a where the head member 32 is disposed (+X side) is called the tip side, and the direction from the first end portion 31a toward the second end portion 31b (-X side) is called the rear end side. In this embodiment, the cutting insert 2 is held by the head member 32 in a posture in which the cutting edge 21 protrudes from the tip of the head member 32 toward the tip side. Therefore, the tip side may also be referred to as the protruding direction.

[0027] The Y-axis direction is a direction orthogonal to the X-axis direction. The Y-axis direction is the direction in which a pair of side surfaces of the shank portion 31 face, that is, the direction in which a pair of side surfaces of the holder 3 face, and corresponds to the tool width direction (left-right direction) of the groove insertion tool 1. The tool width direction may also be referred to as the first direction. The head member 32 is disposed in a recess 31f formed in the first side surface 31c among a pair of side surfaces (the first side surface 31c and the second side surface 31d) of the shank portion 31. Among the tool width direction, the direction (+Y side) from the second side surface 31d of the shank portion 31 toward the first side surface 31c where the head member 32 is disposed is called the right side, and the direction (-Y side) from the first side surface 31c toward the second side surface 31d is called the left side. The right side may also be referred to as one side of the first direction. The left side may also be referred to as the other side of the first direction.

[0028] The Z-axis direction is a direction orthogonal to the X-axis direction and the Y-axis direction. The Z-axis direction is the direction in which the top surface and the bottom surface of the shank portion 31 face, that is, the direction in which the top surface and the bottom surface of the holder 3 face, and corresponds to the vertical direction (height direction) of the groove insertion tool 1. The vertical direction may also be referred to as the second direction. Among the vertical direction, the direction (+Z side) in which the rake face 22 of the cutting insert 2 faces is called the upper side, and the direction opposite to the direction in which the rake face 22 faces (-Z side) is called the lower side. The upper side may also be referred to as one side of the second direction. The lower side may also be referred to as the other side of the second direction.

[0029] In the present embodiment, the left side, the right side, the upper side, and the lower side are merely names for explaining the relative positional relationship of each part, and the arrangement relationship during actual use, etc., may be an arrangement other than the arrangement relationship indicated by these names.

[0030] 〔Holder〕 The shank portion 31 is made of metal such as steel, for example. The first end portion 31a of the shank portion 31 has larger dimensions in the vertical direction and the tool width direction than the portions other than the first end portion 31a. The portion of the shank portion 31 other than the first end portion 31a has a prismatic shape extending in the axial direction.

[0031] The shank portion 31 has a recess 31f. The recess 31f is concave and recessed leftward from the first side surface 31c facing the right side of the shank portion 31. The recess 31f is disposed at the end portion on the tip side of the first side surface 31c. The recess 31f is a notch that opens rightward, toward the tip side, and upward in the shank portion 31. The recess 31f is constituted by a plurality of wall surfaces (inner wall surfaces) including at least one wall surface facing the right side.

[0032] The recess 31f has a mounting surface 31e. The mounting surface 31e is disposed on the wall surface facing the right side in the recess 31f. The mounting surface 31e is planar and extends in a direction perpendicular to the tool width direction.

[0033] The head member 32 is made of metal. The head member 32 may be formed by casting or machining, or may be formed, for example, by laminating a metal powder material while melting it using a 3D printer. The head member 32 is fixed to the first end portion 31a, i.e., the tip portion, of the shank portion 31 by screwing or the like using a fixing screw 8 and a fastening screw 11. As shown in FIGS. 1 to 3, the head member 32 has a head body 33 in the shape of a plate and a plate-shaped head fixing plate 34 extending vertically leftward from the head body 33.

[0034] The head body 33 is entirely in the shape of a plate extending in a direction perpendicular to the tool width direction, and a part of the head body 33 is disposed in the recess 31f. Of the pair of plate surfaces of the head body 33 facing the tool width direction, the plate surface 33a facing the left side contacts the mounting surface 31e of the recess 31f.

[0035] The head body 33 has an insert mounting seat 35 on which the cutting insert 2 is disposed, a pair of jaws 36 that contact the cutting insert 2 from above and below, a slit 37 formed between these jaws 36, a connecting portion 38 that elastically connects the pair of jaws 36, and a first screw insertion hole 39 for inserting a part of the fixing screw 8. In this embodiment, a pair of jaws 36 having jaw channels are provided vertically, but in the present invention, the jaws having jaw channels may be disposed on at least one of the upper side and the lower side of the insert mounting seat 35, and the jaws having jaw channels are plate-shaped and extend in a direction perpendicular to the tool width direction. The holder 3 of this embodiment has an insert mounting seat 35 and jaws 36 for fixing the cutting insert 2 within the insert mounting seat 35. In this embodiment, a pair of jaws 36 are provided on the upper side and the lower side of the insert mounting seat 35. Of these pair of jaws 36, one jaw 36 located on the upper side of the insert mounting seat 35 is the upper jaw 36a, and the other jaw 36 located on the lower side of the insert mounting seat 35 is the lower jaw 36b.

[0036] The insert mounting seat 35 is located at the tip side portion of the head body 33. That is, the insert mounting seat 35 is disposed at the tip of the holder 3. The insert mounting seat 35 is notch-shaped or slit-shaped and opens at the tip side, left side, and right side in the head body 33. The cutting insert 2 is detachably mounted on the insert mounting seat 35. As shown in FIG. 3, the insert mounting seat 35 has a pressing surface 35a that abuts on the upper surface of the cutting insert 2, a pedestal surface 35b that supports the lower surface of the cutting insert 2, and an abutting surface 35c that the rear end of the cutting insert 2 abuts on.

[0037] The pressing surface 35a is constituted by the lower surface of the upper jaw 36a. The pressing surface 35a has a V-shaped cross-sectional shape that is convex downward over its entire length and is perpendicular to the axial direction (X-axis direction). The pressing surface 35a contacts the upper surface of the cutting insert 2 and presses the cutting insert 2 from above.

[0038] The pedestal surface 35b is constituted by the upper surface of the lower jaw portion 36b. The pedestal surface 35b has a V-shaped cross-sectional shape perpendicular to the axial direction over its entire length, convex upward. The pedestal surface 35b contacts the lower surface of the cutting insert 2 and supports the cutting insert 2 from below.

[0039] The abutting surface 35c is disposed at the rear end of the insert mounting seat 35 and faces the tip side. The abutting surface 35c is in a planar shape substantially perpendicular to the axial direction. The abutting surface 35c contacts the rear end surface of the cutting insert 2 and supports the cutting insert 2 from the rear end side.

[0040] As shown in FIG. 2, the pair of jaw portions 36 are curved such that the left side surface is convex and the right side surface is concave when viewed from the tool tip side, and the plate thickness becomes thinner as they move away from the insert mounting seat 35 in the vertical direction. Specifically, the upper jaw portion 36a becomes thinner as it moves away from the insert mounting seat 35 upward, and the lower jaw portion 36b becomes thinner as it moves away from the insert mounting seat 35 downward. In the present embodiment, the upper jaw portion 36a is curved so as to be positioned on the right side as it moves upward from the insert mounting seat 35, and the lower jaw portion 36b is curved so as to be positioned on the right side as it moves downward from the insert mounting seat 35.

[0041] As shown in FIG. 3, the upper jaw portion 36a decreases in dimension in the vertical direction as it moves toward the tip side of the holder 3, and the lower jaw portion 36b also decreases in dimension in the vertical direction as it moves toward the tip side of the holder 3. The lower jaw portion 36b protrudes more toward the tip side of the holder 3 than the upper jaw portion 36a. The dimension of the lower jaw portion 36b in the vertical direction is larger than the dimension of the upper jaw portion 36a in the vertical direction at the opposing position.

[0042] The slit 37 is disposed at the rear end side of the insert mounting seat 35 and is connected to the insert mounting seat 35. The slit 37 extends in the axial direction of the holder 3 so as to divide the head body 33 into an upper part and a lower part together with the insert mounting seat 35. The slit 37 is in a slit shape that opens on the left side and the right side in the head body 33.

[0043] The connecting part 38 is arranged at a position corresponding to the end of the slit 37 on the rear end side of the head body 33, and connects the upper part of the head body 33 including the upper jaw part 36a and the lower part including the lower jaw part 36b. The connecting part 38 is elastically deformable. When the connecting part 38 elastically deforms, the vertical interval between the lower surface of the upper jaw part 36a and the upper surface of the lower jaw part 36b changes. That is, the connecting part 38 connects the upper jaw part 36a and the lower jaw part 36b so as to be elastically displaceable in the vertical direction.

[0044] The first screw insertion hole 39 is arranged at the rear end side part of the head body 33. The first screw insertion hole 39 penetrates the head body 33 in the tool width direction (Y-axis direction). That is, the first screw insertion hole 39 penetrates the head body 33 in its plate thickness direction. A plurality of first screw insertion holes 39 are provided, and in this embodiment, two first screw insertion holes 39 are formed at intervals in the vertical and front-rear directions.

[0045] As shown in FIG. 2, the head fixing plate 34 protrudes to the left from the substantially central part in the front-rear direction of the head body 33. The head fixing plate 34 is in a plate shape that extends in a direction perpendicular to the axial direction (X-axis direction). The head fixing plate 34 has a plurality of second screw insertion holes 34a, and in this embodiment, two second screw insertion holes 34a are formed at intervals in the vertical direction.

[0046] The second screw insertion hole 34a penetrates the head fixing plate 34 in the axial direction of the holder 3. That is, the second screw insertion hole 34a penetrates the head fixing plate 34 in its plate thickness direction.

[0047] 〔Cutting insert〕 As shown in FIGS. 1 and 2, the cutting insert 2 is in a shaft shape or column shape extending in the axial direction. The cutting insert 2 in this embodiment is substantially square columnar. The cutting insert 2 is inserted into the insert mounting seat 35 of the head member 32 from the front and is detachably attached. The cutting insert 2 has a rake face 22, a flank face 23, and a cutting edge 21.

[0048] The rake face 22 is disposed at the front end of the cutting insert 2 and faces upward. The rake face 22 is square when viewed from above. The flank face 23 is disposed at the front end of the cutting insert 2. The flank face 23 has a face facing the front end side (front flank face) and faces on the left side and the right side (a pair of side flank faces).

[0049] The cutting edge 21 is located at the ridge line where the rake face 22 and the three flank faces 23 are respectively connected. The cutting edge 21 is disposed so as to project from the head body 33 toward the tip side, the left side, and the right side. In the present embodiment, the cutting edge 21 has a front cutting edge 21a and a pair of side cutting edges. The front cutting edge 21a extends in the tool width direction (Y-axis direction). That is, the cutting edge 21 has a cutting edge portion 21a that extends in the tool width direction. The pair of side cutting edges are connected to both ends of the front cutting edge 21a in the tool width direction and extend from each end toward the rear end side. Therefore, the cutting edge 21 is substantially U-shaped in top view. The cutting insert 2 of the present embodiment has a pair of sets of the rake face 22, the flank face 23, and the cutting edge 21 at both axial ends of the cutting insert 2.

[0050] 〔Fixing Screw〕 The fixing screw 8 fixes the head member 32 to the tip of the shank portion 31. A plurality of fixing screws 8 are provided. In this embodiment, as the plurality of fixing screws 8, there are two first fixing screws 8a and two second fixing screws 8b. The first fixing screw 8a fixes the head body 33 to the right side surface of the shank portion 31. The first fixing screw 8a is inserted into the first screw insertion hole 39 of the head body 33 and screwed into a first screw hole (not shown) of the shank portion 31. It is preferable that a plurality of first fixing screws 8a are provided. The second fixing screw 8b fixes the head fixing plate 34 to the front end surface of the shank portion 31. The second fixing screw 8b is inserted into the second screw insertion hole 34a of the head fixing plate 34 and screwed into a second screw hole (not shown) of the shank portion 31. It is preferable that a plurality of second fixing screws 8b are provided.

[0051] 〔Fastening Screw〕 The fastening screw 11 has the function of fixing the head member 32 to the upper surface of the front end portion of the shank portion 31 and fixing the cutting insert 2 to the insert mounting seat 35. The fastening screw 11 is screwed into a third screw hole (not shown) formed on the upper surface of the front end portion of the shank portion 31 while pressing the upper portion including the upper jaw portion 36a of the head body 33 downward. When the fastening screw 11 is tightened, the upper portion of the head body 33 is pressed downward, so that the connecting portion 38 is elastically deformed and the upper jaw portion 36a is displaced downward. As a result, the cutting insert 2 disposed on the insert mounting seat 35 is clamped between the lower surface (pressing surface 35a) of the upper jaw portion 36a and the upper surface (pedestal surface 35b) of the lower jaw portion 36b.

[0052] 〔Coolant Flow Path〕 The coolant flow path 4 extends through the inside of the shank portion 31 and the inside of the head member 32. Although not shown, among the coolant flow paths 4, the shank portion flow path extending through the inside of the shank portion 31 is connected to a hose or the like of the coolant supply means of the machine tool. Specifically, the head member flow path 41 extending through the inside of the head member 32 is disposed inside the head body 33. Coolant supplied from the coolant supply means flows through the inside of the coolant flow path 4.

[0053] As shown in FIGS. 1 to 3, the head member flow path 41 has a connection flow path 42 connected to the shank portion flow path and a jaw portion flow path 43 communicating with the connection flow path 42 and extending through the inside of the jaw portion 36. That is, the coolant flow path 4 has the connection flow path 42 and the jaw portion flow path 43.

[0054] The connection flow path 42 extends in the tool width direction. A pair of connection flow paths 42 are provided in the head body 33 at intervals in the vertical direction. Of the pair of connection flow paths 42, one connection flow path 42 disposed at the upper portion of the head body 33 is the upper connection flow path 42a, and the other connection flow path 42 disposed at the lower portion of the head body 33 is the lower connection flow path 42b.

[0055] The upper connection channel 42a has a circular cross-sectional shape perpendicular to the tool width direction. The upper connection channel 42a opens above the plate surface 33a facing the left side of the head body 33. The inner diameter of the upper connection channel 42a decreases as it extends to the right from the opening in the plate surface 33a. That is, the cross-sectional area of the upper connection channel 42a decreases as it extends to the right.

[0056] The lower connection channel 42b has a circular cross-sectional shape perpendicular to the tool width direction. The lower connection channel 42b opens below the plate surface 33a facing the left side of the head body 33. The inner diameter of the lower connection channel 42b decreases as it extends to the right from the opening in the plate surface 33a. That is, the cross-sectional area of the lower connection channel 42b decreases as it extends to the right.

[0057] The jaw channel 43 extends in a direction perpendicular to the tool width direction from the position connected to the connection channel 42. Specifically, the jaw channel 43 extends from the connection portion with the connection channel 42 toward the tool tip side so as to approach the insert mounting seat 35. In this embodiment, a pair of jaw channels 43 are provided in the head body 33 at intervals in the vertical direction. Of the pair of jaw channels 43, one jaw channel 43 disposed in the upper jaw 36a is the upper jaw channel 43a, and the other jaw channel 43 disposed in the lower jaw 36b is the lower jaw channel 43b. That is, the jaw channels 43 are provided in each jaw 36 respectively.

[0058] As shown in FIGS. 3 to 8, the cross-sectional shape of the jaw channel 43 is different in each part in the axial direction (X-axis direction) of the holder 3. The "cross-section of the channel" of the jaw channel 43 referred to in this specification refers to, for example, the cross-section of the channel appearing in a virtual plane perpendicular to the axial direction of the holder 3. The cross-sectional shape of the jaw channel 43 gradually changes as it extends from the connection portion with the connection channel 42 toward the tool tip side.

[0059] Specifically, the jaw channel 43 has a vertically long guide channel portion 44 in which the cross-section of the channel has a dimension a in the vertical direction (Z-axis direction) larger than the dimension b in the tool width direction (Y-axis direction), and communicates with the guide channel portion 44. It is arranged closer to the insert mounting seat 35 in the vertical direction on the tool tip side than the guide channel portion 44 and opens at the end of the jaw 36 on the tool tip side. The cross-section of the channel has a horizontally long ejection channel portion 45 in which the dimension b in the tool width direction is larger than the dimension a in the vertical direction. The cross-section of each channel of the guide channel portion 44 and the ejection channel portion 45 is an elliptical shape. In this embodiment, as shown in FIGS. 5A and 5B, the cross-section of the channel at the connection portion between the guide channel portion 44 and the ejection channel portion 45 is a circular (substantially true circle) shape. The channel cross-sectional area of the guide channel portion 44 and the channel cross-sectional area of the ejection channel portion 45 are the same as each other, or the channel cross-sectional area of the ejection channel portion 45 is smaller than the channel cross-sectional area of the guide channel portion 44.

[0060] As shown in FIGS. 3, 4A, 4B, 7A, and 7B, the guide channel portion 44 is provided in each of the pair of jaw channels 43. The maximum value of the ratio (a / b) of the dimension a in the vertical direction to the dimension b in the tool width direction of the channel cross-section of the guide channel portion 44 is 1.2 or more and 5.0 or less. Of the pair of guide channel portions 44, one guide channel portion 44 provided in the upper jaw channel 43a is the upper guide channel portion 44a, and the other guide channel portion 44 provided in the lower jaw channel 43b is the lower guide channel portion 44b.

[0061] As shown in FIG. 3, the upper guide channel portion 44a extends downward from the connection portion with the upper connection channel 42a toward the tool tip side. The ratio (a / b) of the dimension a in the vertical direction to the dimension b in the tool width direction of the channel cross-section of the upper guide channel portion 44a decreases as it goes toward the tool tip side.

[0062] The lower guide channel portion 44b extends upward from the connection portion with the lower connection channel 42b toward the tool tip side. The ratio (a / b) of the dimension a in the vertical direction to the dimension b in the tool width direction of the channel cross-section of the lower guide channel portion 44b decreases as it goes toward the tool tip side.

[0063] As shown in FIGS. 3, 6A, 6B, 8A, and 8B, the ejection channel portion 45 is provided in each of the pair of jaw channel portions 43. The channel cross-section of the ejection channel portion 45 has a maximum value of the ratio (b / a) of the dimension b in the tool width direction to the dimension a in the vertical direction in the range of 1.2 or more and 5.0 or less. Of the pair of ejection channel portions 45, one ejection channel portion 45 provided in the upper jaw channel portion 43a is the upper ejection channel portion 45a, and the other ejection channel portion 45 provided in the lower jaw channel portion 43b is the lower ejection channel portion 45b.

[0064] As shown in FIG. 3, the upper ejection channel portion 45a extends downward from the connection portion with the upper guide channel portion 44a toward the tool tip side. The channel cross-section of the upper ejection channel portion 45a has a ratio (b / a) of the dimension b in the tool width direction to the dimension a in the vertical direction that increases toward the tool tip side. The tip portion of the upper ejection channel portion 45a opens to the surface facing the tip side of the upper jaw portion 36a. The tip portion of the upper ejection channel portion 45a, that is, the opening (upper ejection port), is disposed adjacent to the upper side of the insert mounting seat 35. The opening of the upper ejection channel portion 45a opens toward the rake face 22 and the cutting edge 21 of the cutting insert 2.

[0065] The lower ejection channel portion 45b extends upward from the connection portion with the lower guide channel portion 44b toward the tool tip side. The channel cross-section of the lower ejection channel portion 45b has a ratio (b / a) of the dimension b in the tool width direction to the dimension a in the vertical direction that increases toward the tool tip side. The tip portion of the lower ejection channel portion 45b opens to the surface facing the tip side of the lower jaw portion 36b. The tip portion of the lower ejection channel portion 45b, that is, the opening (lower ejection port), is disposed adjacent to the lower side of the insert mounting seat 35. The opening of the lower ejection channel portion 45b opens toward the flank face 23 and the cutting edge 21 of the cutting insert 2.

[0066] 〔Advantages and Effects of the Present Embodiment〕 According to the grooving tool 1 of the present embodiment described above, even if the jaw portion 36 that clamps the cutting insert 2 is a curved plate shape whose plate thickness becomes thinner as it moves away from the insert mounting seat 35 in the vertical direction, coolant can be accurately and stably ejected from the jaw channel portion 43 extending inside the jaw portion 36 toward the vicinity of the cutting edge 21.

[0067] Specifically, among the jaw channels 43, the cross-section of the ejection channel portion 45 that opens at the end of the jaw portion 36 on the tool tip side has a horizontally long shape in which the dimension b in the tool width direction is larger than the dimension a in the vertical direction. Therefore, this ejection channel portion 45 is arranged in a portion of the jaw portion 36 where the plate thickness is thick, that is, a portion close to the insert mounting seat 35, so that the coolant can be stably ejected over a wide range from the ejection channel portion 45 to the entire cutting edge 21 including at least the cutting edge portion 21a. Also, among the jaw channels 43, the cross-section of the guide channel portion 44 has a vertically long shape in which the dimension a in the vertical direction is larger than the dimension b in the tool width direction. Therefore, this guide channel portion 44 can be arranged in a portion of the jaw portion 36 where the plate thickness is thin (thin-walled portion) and is vertically separated from the insert mounting seat 35. That is, while ensuring a large cross-sectional area of the guide channel portion 44, that is, while ensuring the flow rate of the coolant ejected from the jaw portion 36, this guide channel portion 44 can be arranged in the thin-walled portion of the jaw portion 36. Therefore, it is easy to incline the channel shape from the guide channel portion 44 to the ejection channel portion 45 at an angle in the vertical direction as it goes toward the tool tip side. For this reason, it becomes easy to arrange the cutting edge 21 near the extension line of the opening (ejection port) of the ejection channel portion 45, and the coolant can be accurately and efficiently supplied near the cutting edge 21.

[0068] Also, in the present embodiment, a pair of jaw portions 36 are provided above and below the insert mounting seat 35, and the jaw channels 43 are provided in each jaw portion 36 respectively. In this case, among the pair of jaw portions 36, from the jaw channel 43 (upper jaw channel 43a) of the upper jaw portion 36a arranged above the insert mounting seat 35, the coolant can be ejected near the cutting edge 21 through the rake face 22 of the cutting insert 2. Also, among the pair of jaw portions 36, from the jaw channel 43 (lower jaw channel 43b) of the lower jaw portion 36b arranged below the insert mounting seat 35, the coolant can be ejected near the cutting edge 21 through the flank face 23 of the cutting insert 2. For this reason, the coolant can be supplied more stably near the cutting edge 21.

[0069] Further, in the present embodiment, the flow path cross-sectional area of the ejection flow path portion 45 is smaller than that of the guide flow path portion 44, or the flow path cross-sectional area of the guide flow path portion 44 is the same as that of the ejection flow path portion 45. For example, different from the present embodiment, if the flow path cross-sectional area of the ejection flow path portion 45 is larger than that of the guide flow path portion 44, when the coolant flows from the guide flow path portion 44 into the ejection flow path portion 45, a decrease in flow velocity, pressure loss, etc. may occur due to the increase in the flow path cross-sectional area. On the other hand, according to the present embodiment, when the coolant flows from the guide flow path portion 44 into the ejection flow path portion 45, a decrease in flow velocity, pressure loss, etc. can be suppressed. The flow velocity of the coolant flowing through the ejection flow path portion 45 is stably increased, and the vicinity of the cutting edge 21 can be efficiently cooled by the coolant ejected from the ejection flow path portion 45.

[0070] Further, in the present embodiment, in the flow path cross-section of the guide flow path portion 44, the ratio (a / b) of the dimension a in the vertical direction to the dimension b in the tool width direction is 1.2 or more and 5.0 or less. When the ratio (a / b) is 1.2 or more, the flow path cross-section of the guide flow path portion 44 stably becomes a vertically long shape, and it is easy to arrange this guide flow path portion 44 in the thin portion of the jaw portion 36. Therefore, the operational effects of the present embodiment described above can be obtained more stably. When the ratio (a / b) is 5.0 or less, problems such as an increase in pressure loss due to the flow path cross-section being too vertically long and flat can be suppressed.

[0071] Further, in the present embodiment, in the flow path cross-section of the ejection flow path portion 45, the ratio (b / a) of the dimension b in the tool width direction to the dimension a in the vertical direction is 1.2 or more and 5.0 or less. When the ratio (b / a) is 1.2 or more, the flow path cross-section of the ejection flow path portion 45 stably becomes a horizontally long shape, and it is easy to stably eject the coolant from this ejection flow path portion 45 over the entire cutting edge 21. Therefore, the operational effects of the present embodiment described above can be obtained more stably. When the ratio (b / a) is 5.0 or less, problems such as the coolant being sprayed in a mist shape and the coolant being wasted and dissipated to parts other than the cutting edge 21 due to the flow path cross-section being too horizontally long and flat can be suppressed.

[0072] [Other configurations included in the present invention] The present invention is not limited to the above-described embodiments. For example, as described below, configuration changes and the like are possible without departing from the gist of the present invention.

[0073] In the above-described embodiment, an example was given in which the cross-section of each flow path of the guide flow path portion 44 and the ejection flow path portion 45 is an elliptical shape, but the present invention is not limited to this. FIGS. 9 to 13 show modified examples of the head member 32 of the grooving tool 1 described in the above-described embodiment. In this modified example, the cross-section of each flow path of the guide flow path portion 44 and the ejection flow path portion 45 is a polygonal shape. In the illustrated example, the cross-section of each flow path of the guide flow path portion 44 and the ejection flow path portion 45 is a triangular shape. In addition to the triangular shape, it may be a quadrangular shape (rhombus shape), a pentagonal shape, a hexagonal shape, or the like. In this modified example, as shown in FIGS. 12A and 12B, the cross-section of the flow path at the connection portion between the guide flow path portion 44 and the ejection flow path portion 45 is an equilateral triangular shape.

[0074] As shown in FIGS. 11A and 11B, in the flow path cross-section of the guide flow path portion 44, the ratio (a / b) of the dimension a in the vertical direction to the dimension b in the tool width direction is 1.2 or more and 5.0 or less. As shown in FIGS. 13A and 13B, in the flow path cross-section of the ejection flow path portion 45, the ratio (b / a) of the dimension b in the tool width direction to the dimension a in the vertical direction is 1.2 or more and 5.0 or less. As shown in FIG. 10, the connection flow path 42 has a polygonal shape, specifically a triangular shape, in the cross-section of the flow path perpendicular to the tool width direction. Also in this modified example, the same operational effects as those of the above-described embodiment can be obtained. As shown in this modified example, the set of the connection flow path 42 and the jaw flow path 43 of the coolant flow path 4 may be provided only once in the head member 32.

[0075] In the above-described embodiment, as viewed from the tool tip side, the upper jaw portion 36a is curved so as to be located on the right side (+Y side) as it goes upward (+Z side) from the insert mounting seat 35, and the lower jaw portion 36b is curved so as to be located on the right side as it goes downward (-Z side) from the insert mounting seat 35. However, the present invention is not limited to this example. Although not particularly illustrated, as viewed from the tool tip side, the upper jaw portion 36a may be curved so as to be located on the left side (-Y side) as it goes upward from the insert mounting seat 35, and the lower jaw portion 36b may be curved so as to be located on the left side as it goes downward from the insert mounting seat 35.

[0076] In the above-described embodiment, an example is given in which a pair of jaw portions 36 having jaw channels are provided on the upper and lower sides of the insert mounting seat 35. However, the present invention is not limited to this. Only one jaw portion having a jaw channel may be provided on the upper side or the lower side of the insert mounting seat 35. In this case, the cutting insert 2 is clamped between the jaw portion having no jaw channel and the jaw portion having a jaw channel, and is fixed to the insert mounting seat. Although not illustrated, the jaw portion having no jaw channel may be formed separately from the head member 32. In this case, the jaw portion having no jaw channel is constituted by a clamping member that can approach the jaw portion having a jaw channel by sliding movement or the like to clamp the cutting insert 2.

[0077] The present invention may combine the respective configurations described in the above-described embodiments and modifications within the scope not departing from the gist of the present invention. Also, addition, omission, substitution, and other changes of the configuration are possible. Further, the present invention is not limited by the above-described embodiments, etc., and is limited only by the claims.

Industrial Applicability

[0078] According to the grooving tool of the present invention, while ensuring the coolant flow rate, the coolant can be accurately ejected near the cutting edge. Therefore, it has industrial applicability.

Explanation of Signs

[0079] 1… Grooving tool 2… Cutting insert 3… Holder 4… Coolant passage 21… Cutting edge 21a… Front edge (cutting edge part) 35… Insert mounting seat 36… Jaw part 43… Jaw passage 44… Guide passage part 45… Ejection passage part a… Dimension in the vertical direction of the passage cross-section b… Dimension in the tool width direction of the passage cross-section

Claims

1. A cutting insert having a cutting edge, a holder for holding the cutting insert, and a coolant flow path extending inside the holder, wherein the cutting edge has a cutting edge portion extending in the tool width direction, the holder includes an insert mounting seat on which the cutting insert is disposed, and a pair of jaws disposed above and below the insert mounting seat and contacting the cutting insert from above and below in the vertical direction, wherein at least one of the jaws is plate-shaped and extends in a direction perpendicular to the tool width direction, and has a curved shape when viewed from the tool tip side, and the plate thickness decreases as it moves away from the insert mounting seat upward or downward, the coolant flow path has a jaw flow path extending inside at least one of the jaws, the jaw flow path includes a guiding flow path portion, and a jetting flow path portion that communicates with the guiding flow path portion, is disposed closer to the insert mounting seat than the guiding flow path portion on the tool tip side and in the vertical direction, and opens at the end of the jaw on the tool tip side, the cross section of the flow path of the guiding flow path portion is vertically long, with the vertical dimension being larger than the dimension in the tool width direction, the cross section of the flow path of the jetting flow path portion is horizontally long, with the dimension in the tool width direction being larger than the vertical dimension. A grooving tool.

2. The jaw flow path is provided in each of the jaws, The grooving tool according to claim 1.

3. The cross-sectional area of the flow path of the jetting flow path portion is smaller than the cross-sectional area of the flow path of the guiding flow path portion, The grooving tool according to claim 1 or 2.

4. The cross-sectional area of the flow path of the guiding flow path portion and the cross-sectional area of the flow path of the jetting flow path portion are the same as each other, The grooving tool according to claim 1 or 2.

5. In the cross section of the flow path of the guiding flow path portion, the maximum value of the ratio a / b of the vertical dimension a to the dimension b in the tool width direction is 1.2 or more and 5.0 or less, and the ratio a / b of the guiding flow path portion decreases as it goes toward the tool tip side, The grooving tool according to any one of claims 1 to 4.

6. In the cross section of the flow path of the jetting flow path portion, the maximum value of the ratio b / a of the dimension b in the tool width direction to the vertical dimension a is 1.2 or more and 5.0 or less, and the ratio b / a of the jetting flow path portion increases as it goes toward the tool tip side, The grooving tool according to any one of claims 1 to 5.

7. The cross section of each flow path of the guiding flow path portion and the jetting flow path portion is elliptical, The grooving tool according to any one of claims 1 to 6.

8. wherein cross-sections of the respective flow paths of the guide flow path portion and the ejection flow path portion are polygonal; The grooving tool according to any one of claims 1 to 6.

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