Grooving tools

Abstract

The grooving tool comprises a cutting blade (2), a tool holder (3) and a coolant flow path (4). The tool holder (3) comprises: a blade mounting seat (35); and a jaw (36) arranged above and below the blade mounting seat (35) to fix the cutting blade (2). The jaw (36) is curved when viewed from the front end of the tool and becomes thinner as it moves away from the blade mounting seat (35). The coolant flow path (4) comprises a jaw flow path (43) extending inside the jaw (36), and the jaw flow path (43) comprises: a longitudinal guide flow path portion (44), wherein the dimension a in the vertical direction of the flow path cross section is larger than the dimension b in the tool width direction; and a transverse injection flow path portion (45), wherein the dimension b in the tool width direction of the flow path cross section is larger than the dimension a in the vertical direction.

Description

Technical Field

[0001] The invention relates to a grooving tool.

[0002] This application claims priority based on patent application No. 2020-145526 filed in Japan on August 31, 2020, and patent application No. 2021-138204 filed in Japan on August 26, 2021, and the contents of these are incorporated herein by reference. Background Art

[0003] A grooving tool for grooving the end face and peripheral surface of a workpiece is known. The grooving tool comprises a cutting insert having a cutting edge, a toolholder that holds the cutting insert, and a coolant flow path extending within the toolholder. The toolholder includes an insert mounting seat for receiving the cutting insert, and a pair of jaws disposed above and below the insert mounting seat for contacting the cutting insert from above and below. Conventional grooving tools, for example, are known, such as that described in Patent Document 1.

[0004] Patent Document 1: Japanese Patent Application Laid-Open No. 2015-93380

[0005] For example, in grooving tools such as those used for face grooving, the jaws sometimes have a curved shape when viewed from the tool's front end. In these cases, the jaw thickness decreases as it moves vertically away from the insert mounting seat. In such grooving tools, it is difficult to create a desired coolant flow path within the jaws.

[0006] For example, to supply coolant near the cutting edge via the flank face of the cutting insert, the coolant flow path within the jaw portion must be angled upward toward the tool tip, so that the area near the coolant flow path's injection port is inclined closer to the flank face. However, the thinner portion and curved shape of the jaw portion impose various limitations, forcing the coolant flow path's cross-sectional area to be reduced or preventing the coolant flow path from being sufficiently tilted.

[0007] Specifically, if the coolant flow path is intended to be passed through the thinner portion of the jaws in order to precisely spray the coolant near the cutting edge, the cross-sectional area of ​​the coolant flow path must be reduced, resulting in a decrease in the coolant flow rate. Furthermore, if the coolant flow path is intended to be passed through the thicker portion of the jaws in order to ensure a larger cross-sectional area, it becomes difficult to tilt the coolant flow path near the injection port, making it impossible to precisely spray the coolant near the cutting edge. Summary of the Invention

[0008] One of the objects of the present invention is to provide a grooving tool that can spray coolant near the cutting edge with high precision while ensuring the coolant flow rate.

[0009] One embodiment of the grooving tool of the present invention comprises: a cutting insert having a cutting edge; a toolholder for retaining the cutting insert; and a coolant flow path extending within the toolholder. The cutting edge has a cutting edge portion extending along the tool width direction; the toolholder has an insert mounting seat for receiving the cutting insert; and a pair of jaws disposed above and below the insert mounting seat, the jaws contacting the cutting insert from above and below. At least one of the jaws is plate-shaped, extending in a direction perpendicular to the tool width direction, extending in a curved shape when viewed from the tool front end, and decreasing in thickness vertically away from the insert mounting seat. The coolant flow path comprises a jaw flow path extending within the at least one jaw. The jaw flow path comprises a guide flow path portion having an elongated flow path cross-section with a vertical dimension greater than its tool width dimension; and an injection flow path portion communicating with the guide flow path portion. The injection flow path portion is disposed closer to the tool front end than the guide flow path portion and vertically adjacent to the insert mounting seat, and opens at the tool front end end of the jaw portion. The flow path cross section of the injection flow path portion is horizontally elongated, with the dimension in the tool width direction being larger than the dimension in the vertical direction. In addition, in this specification, the "cross section" of the guide flow path portion and the injection flow path portion refers to the cross section expressed in an imaginary plane perpendicular to the axial direction of the tool holder.

[0010] According to the grooving tool of the above embodiment, even if the jaw portion for securing the cutting insert is a curved plate whose thickness decreases as it moves away from the insert mounting seat in the vertical direction, coolant can be sprayed stably and accurately toward the vicinity of the cutting edge from the jaw portion flow path extending therein.

[0011] Specifically, the flow path cross section of the jet flow path portion of the jaw flow path that opens at the end portion on the tool front end side is a horizontally long shape in which the dimension in the tool width direction is larger than the dimension in the vertical direction. Therefore, the jet flow path portion can be arranged in the thicker plate portion of the jaw, that is, the portion close to the insert mounting seat, and coolant can be stably sprayed from the jet flow path portion to the entire cutting edge area including at least the cutting edge portion over a wide range.

[0012] Furthermore, the guide flow path section in the jaw flow path has a longitudinal cross-section with a vertical dimension larger than the tool width dimension. This allows the guide flow path section to be positioned in a thinner portion (thin-walled portion) of the jaw, vertically away from the insert mounting seat. Specifically, while ensuring a large cross-sectional area for the guide flow path section, i.e., while ensuring the flow rate of coolant ejected from the jaw, the guide flow path section can be positioned in the thin-walled portion of the jaw. This facilitates the flow path from the guide flow path section to the ejection flow path section to tilt vertically toward the tool tip. This facilitates positioning the cutting edge near the extension of the ejection flow path section's opening (injection port), enabling high-precision and efficient coolant delivery to the vicinity of the cutting edge.

[0013] In the grooving tool, the jaw flow path may be provided in each of the jaws.

[0014] In this case, the coolant can be sprayed from the jaw flow path of the upper jaw, located above the insert mounting seat, toward the vicinity of the cutting edge, passing over the rake face of the cutting insert. Furthermore, the coolant can be sprayed from the jaw flow path of the lower jaw, located below the insert mounting seat, toward the vicinity of the cutting edge, passing over the flank face of the cutting insert. This allows for more stable coolant supply to the vicinity of the cutting edge.

[0015] In the grooving tool, a flow path cross-sectional area of ​​the injection flow path portion may be smaller than a flow path cross-sectional area of ​​the guide flow path portion.

[0016] In the grooving tool, a flow path cross-sectional area of ​​the guide flow path portion and a flow path cross-sectional area of ​​the ejection flow path portion may be equal to each other.

[0017] For example, unlike the above structure, if the flow path cross-sectional area of ​​the injection flow path portion is larger than the flow path cross-sectional area of ​​the guide flow path portion, when the coolant flows from the guide flow path portion to the injection flow path portion, a decrease in flow velocity and pressure loss may sometimes occur due to the increase in flow path cross-sectional area.

[0018] On the other hand, according to any of the above configurations, when the coolant flows from the guide flow path portion into the injection flow path portion, a decrease in flow velocity and pressure loss can be suppressed. The flow velocity of the coolant flowing through the injection flow path portion is stably increased, and the vicinity of the cutting edge can be efficiently cooled by the coolant injected from the injection flow path portion.

[0019] In the grooving tool, a maximum value of a ratio (a / b) of a vertical dimension (a) to a tool width dimension (b) of a flow path cross section of the guide flow path portion may be greater than or equal to 1.2 and less than or equal to 5.0.

[0020] Furthermore, the ratio (a / b) of the guide flow path portion may decrease toward the tool front end side.

[0021] When the maximum value of the ratio (a / b) of the vertical dimension (a) to the tool width dimension (b) in the flow path cross section of the guide flow path portion is 1.2 or greater, the flow path cross section of the guide flow path portion maintains a stable longitudinal shape, making it easier to position the guide flow path portion in the thin-walled portion of the jaw. Consequently, the aforementioned effects of the present invention can be more stably achieved.

[0022] Furthermore, when the maximum value of the ratio (a / b) is 5.0 or less, it is possible to suppress problems such as an increase in pressure loss due to the shape of the flow path cross section being too vertically flat.

[0023] Furthermore, when the ratio (a / b) of the guide flow path portion decreases toward the tool tip side, the cross-sectional shape of the guide flow path portion changes smoothly, and thus the flow path resistance of the guide flow path portion can be suppressed to a low level.

[0024] In the grooving tool, a maximum value of a ratio (b / a) of a dimension (b) in a tool width direction to a dimension (a) in a vertical direction in a flow path cross section of the injection flow path portion may be 1.2 or more and 5.0 or less.

[0025] Furthermore, the ratio (b / a) of the injection flow path portion may increase toward the tool tip end side.

[0026] If the maximum value of the ratio (b / a) of the tool width dimension (b) to the vertical dimension (a) in the flow path section of the injection flow path portion is 1.2 or greater, the flow path section of the injection flow path portion maintains a stable horizontally elongated shape, making it easier to stably spray coolant from the injection flow path portion over the entire cutting edge area. Therefore, the aforementioned effects of the present invention can be more stably achieved.

[0027] Furthermore, if the maximum value of the ratio (b / a) is 5.0 or less, it is possible to suppress the problem that the coolant is sprayed in a mist due to the excessively long and flat shape of the flow path cross section, causing the coolant to spread unnecessarily to parts other than the cutting edge.

[0028] Furthermore, when the ratio (b / a) of the injection flow path portion increases toward the tool tip side, the cross-sectional shape of the injection flow path portion changes smoothly, and thus the flow path resistance of the injection flow path portion can be suppressed to a low level.

[0029] In the grooving tool, each flow path cross section of the guide flow path portion and the injection flow path portion may be elliptical.

[0030] In the grooving tool, each flow path cross section of the guide flow path portion and the injection flow path portion may be a polygon such as a triangle, a quadrilateral, a pentagon, or a hexagon.

[0031] According to the grooving tool of the aspect of the present invention, the coolant can be sprayed near the cutting edge with high precision while ensuring the coolant flow rate. BRIEF DESCRIPTION OF THE DRAWINGS

[0032] Figure 1 This is a perspective view showing a grooving tool according to one embodiment of the present invention.

[0033] Figure 2 This is a front view of the grooving tool according to the present embodiment as viewed from the tool front end side.

[0034] Figure 3 This is a side view of the head member of the tool holder according to the present embodiment as viewed from the tool width direction.

[0035] Figure 4A Yes Figure 3 Cross-sectional view of section IV-IV.

[0036] Figure 4B It is an enlarged representation Figure 4A A partial cross-sectional view of a portion of .

[0037] Figure 5A Yes Figure 3 Cross-sectional view of section VV.

[0038] Figure 5B It is an enlarged representation Figure 5A A partial cross-sectional view of a portion of .

[0039] Figure 6A Yes Figure 3 Cross-sectional view of section VI-VI.

[0040] Figure 6B It is an enlarged representation Figure 6A A partial cross-sectional view of a portion of .

[0041] Figure 7A Yes Figure 3 Cross-sectional view of section VII-VII.

[0042] Figure 7B It is an enlarged representation Figure 7A A partial cross-sectional view of a portion of .

[0043] Figure 8A Yes Figure 3 A cross-sectional view of section VIII-VIII.

[0044] Figure 8B It is an enlarged representation Figure 8A A partial cross-sectional view of a portion of .

[0045] Figure 9 It is a perspective view showing a head member of a tool holder according to a modified example of the present embodiment.

[0046] Figure 10 This is a side view of a head member of a tool holder according to a modified example of the present embodiment as viewed from the tool width direction.

[0047] Figure 11A Yes Figure 10 Cross-sectional view of section XI-XI.

[0048] Figure 11B It is an enlarged representation Figure 11A A partial cross-sectional view of a portion of .

[0049] Figure 12A Yes Figure 10 Cross-sectional view of section XII-XII.

[0050] Figure 12B It is an enlarged representation Figure 12A A partial cross-sectional view of a portion of .

[0051] Figure 13A Yes Figure 10 Cross-sectional view of section XIII-XIII.

[0052] Figure 13B It is an enlarged representation Figure 13A A partial cross-sectional view of a portion of . DETAILED DESCRIPTION

[0053] A grooving tool 1 according to one embodiment of the present invention will be described with reference to the accompanying 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 can be detachably mounted on a tool holder of a machine tool (not shown), such as a lathe. Specifically, the grooving tool 1 of this embodiment is an indexable insert grooving tool for face grooving.

[0054] like Figure 1 and Figure 2As shown, the grooving tool 1 comprises an elongated rectangular cutting insert 2 having a cutting edge 21 at its tip, and a toolholder 3 that holds the cutting insert 2. The toolholder 3 includes a square bar-shaped shank 31 that is attached to a tool holder, etc.; a head member 32 that clamps and secures the cutting insert 2; a coolant flow path 4 that extends within the toolholder 3 and supplies coolant to the cutting edge 21; and a set screw 8 and a tightening screw 11 for securing the cutting head member 32 to the shank 31. The head member 32 is detachably attached to the first end 31a of the two ends (first end 31a and second end 31b) of the shank 31, and holds the cutting insert 2 with the cutting edge 21 protruding from the first end 31a.

[0055] Definition of direction

[0056] In this embodiment, each configuration is described while setting an XYZ orthogonal coordinate system.

[0057] The X-axis direction is the direction in which the central axis of the shank 31 extends, that is, the direction in which the toolholder 3 extends, and corresponds to the axial direction (longitudinal direction) of the grooving tool 1. The direction from the second end 31b of the shank 31 toward the first end 31a of the head member 32 (the +X side) in the axial direction is referred to as the front end side, and the direction from the first end 31a toward the second end 31b (the -X side) is referred to as the rear end side. In this embodiment, the cutting insert 2 is retained in the head member 32 in a position such that the cutting edge 21 protrudes from the front end of the head member 32 toward the front end side. Therefore, the front end side can also be referred to as the protruding direction.

[0058] The Y-axis direction is a direction perpendicular to the X-axis direction. The Y-axis direction is the direction in which a pair of side surfaces of the shank 31 face, that is, the direction in which a pair of side surfaces of the tool holder 3 face, and is equivalent to the tool width direction (left-right direction) of the grooving tool 1. The tool width direction can also be referred to as the first direction. The head component 32 is arranged in the recess 31f of the first side surface 31c formed in the pair of side surfaces (the first side surface 31c and the second side surface 31d) of the shank 31. The direction from the second side surface 31d of the shank 31 toward the first side surface 31c where the head component 32 is arranged in the tool width direction (+Y side) is referred to as the right side, and the direction from the first side surface 31c toward the second side surface 31d (-Y side) is referred to as the left side. The right side can also be referred to as one side of the first direction. The left side can also be referred to as the other side of the first direction.

[0059] The Z-axis direction is a direction perpendicular to the X-axis direction and the Y-axis direction. The Z-axis direction is the direction in which the top and bottom surfaces of the shank 31 are facing, that is, the direction in which the top and bottom surfaces of the tool holder 3 are facing, and is equivalent to the up and down direction (height direction) of the grooving tool 1. The up and down direction can also be referred to as the second direction. The direction in which the rake face 22 of the cutting blade 2 in the up and down direction is facing (+Z side) is called the upper side, and the direction opposite to the direction in which the rake face 22 is facing (-Z side) is called the lower side. The upper side can also be referred to as one side of the second direction. The lower side can also be referred to as the other side of the second direction.

[0060] In this embodiment, left side, right side, upper side and lower side are merely names used to describe the relative positional relationship of each part, and the configuration relationship in actual use may be a configuration other than the configuration relationship represented by these names.

[0061] [Knife holder]

[0062] The shank 31 is made of a metal such as steel. The first end 31a of the shank 31 is larger in the vertical direction and in the tool width direction than the portion other than the first end 31a. The portion other than the first end 31a of the shank 31 is in the shape of a square column extending in the axial direction.

[0063] The handle 31 has a recessed portion 31f. The recessed portion 31f is concave, extending from the first side surface 31c of the handle 31, which faces right, toward the left. The recessed portion 31f is located at the distal end of the first side surface 31c. The recessed portion 31f is a cutout in the handle 31, opening toward the right, distal, and upper sides. The recessed portion 31f is composed of a plurality of wall surfaces (inner wall surfaces), including at least one wall surface facing right.

[0064] The recessed portion 31f has a mounting surface 31e. The mounting surface 31e is arranged on a wall surface facing right in the recessed portion 31f. The mounting surface 31e is a flat surface extending in a direction perpendicular to the tool width direction.

[0065] The head component 32 is made of metal. It can be formed by casting or machining, but can also be formed by, for example, melting and laminating metal powder using a 3D printer. The head component 32 is secured to the first end 31a, or the distal end, of the shank 31 by tightening with the set screw 8 and the set screw 11.

[0066] like Figures 1 to 3 As shown, the head component 32 includes: a head body 33 in a plate shape; and a plate-shaped head fixing plate 34 extending vertically to the left from the head body 33.

[0067] The head body 33 is generally in the shape of a plate extending perpendicularly to the tool width direction, and a portion of the head body 33 is disposed within the recess 31f. Of a pair of plate surfaces of the head body 33 facing the tool width direction, the left-facing plate surface 33a contacts the mounting surface 31e of the recess 31f.

[0068] The head body 33 includes an insert seat 35 for mounting the cutting insert 2; a pair of jaws 36 that contact the cutting insert 2 from above and below; a slit 37 formed between the jaws 36; a connecting portion 38 that elastically connects the pair of jaws 36; and a first screw insertion hole 39 for receiving a portion of the set screw 8. In this embodiment, a pair of jaws 36 with jaw flow passages are provided at the top and bottom. However, in the present invention, the jaws with jaw flow passages only need to be located on at least one of the upper and lower sides of the insert seat 35. The jaws with jaw flow passages are plate-shaped and extend perpendicularly to the tool width. The tool holder 3 of this embodiment includes an insert seat 35 and jaws 36 for securing the cutting insert 2 within the insert seat 35.

[0069] In this embodiment, a pair of jaws 36 are provided on the upper and lower sides of the blade mounting seat 35. One jaw 36 located on the upper side of the blade mounting seat 35 is an upper jaw 36a, and the other jaw 36 located on the lower side of the blade mounting seat 35 is a lower jaw 36b.

[0070] The insert mounting seat 35 is located at the front end of the head body 33. Specifically, the insert mounting seat 35 is disposed at the front end of the tool holder 3. The insert mounting seat 35 is in the shape of a notch or slit that opens toward the front end, left, and right sides of the head body 33. The cutting insert 2 is detachably mounted to the insert mounting seat 35.

[0071] like Figure 3 As shown, the insert mounting seat 35 has a pressing surface 35 a that contacts the upper surface of the cutting insert 2 , a seating surface 35 b that supports the lower surface of the cutting insert 2 , and a contact surface 35 c that contacts the rear end of the cutting insert 2 .

[0072] The pressing surface 35a is formed by the lower surface of the upper jaw 36a. The pressing surface 35a has a downwardly convex V-shaped cross-section perpendicular to the axial direction (X-axis direction) along its entire length. The pressing surface 35a contacts the upper surface of the cutting insert 2, pressing the cutting insert 2 from above.

[0073] The base surface 35b is formed by the upper surface of the lower jaw portion 36b. The base surface 35b has a V-shaped cross-section perpendicular to the axial direction over its entire length, which is convex upward. The base surface 35b contacts the lower surface of the cutting insert 2 and supports the cutting insert 2 from the bottom.

[0074] The contact surface 35c is disposed at the rear end of the insert mounting seat 35 and faces the front end. The contact surface 35c is a flat surface substantially perpendicular to the axial direction. The contact surface 35c contacts the rear end surface of the cutting insert 2 and supports the cutting insert 2 from the rear end side.

[0075] like Figure 2 As shown, the pair of jaws 36 are curved, with the left side convex and the right side concave when viewed from the front end of the tool. The thickness of the jaws decreases as they move vertically away from the blade mounting seat 35. Specifically, the upper jaw 36a decreases in thickness as it moves upward away from the blade mounting seat 35, while the lower jaw 36b decreases in thickness as it moves downward away from the blade mounting seat 35. In this embodiment, the upper jaw 36a is curved so that it moves upward from the blade mounting seat 35, while the lower jaw 36b is curved so that it moves downward from the blade mounting seat 35.

[0076] like Figure 3 As shown, the upper jaw portion 36a decreases in size in the vertical direction toward the front end of the tool holder 3, and the lower jaw portion 36b also decreases in size in the vertical direction toward the front end of the tool holder 3. The lower jaw portion 36b protrudes further toward the front end of the tool holder 3 than the upper jaw portion 36a. The vertical dimension of the lower jaw portion 36b is larger than the vertical dimension of the upper jaw portion 36a at the opposing position.

[0077] The slit 37 is arranged on the rear end side of the insert mounting seat 35 and is connected to the insert mounting seat 35. The slit 37 extends along the axial direction of the tool holder 3 so as to divide the head body 33 into an upper portion and a lower portion together with the insert mounting seat 35. The slit 37 is in the shape of a slit that opens to the left and right sides of the head body 33.

[0078] The connecting portion 38 is located on the rear end of the head body 33 at a position corresponding to the end of the slit 37. It connects the upper portion of the head body 33, including the upper jaw 36a, to the lower portion of the head body 33, including the lower jaw 36b. The connecting portion 38 is elastically deformable. The elastic deformation of the connecting portion 38 changes the vertical distance between the lower surface of the upper jaw 36a and the upper surface of the lower jaw 36b. In other words, the connecting portion 38 connects the upper jaw 36a and the lower jaw 36b in a manner that allows for elastic displacement in the vertical direction.

[0079] The first screw insertion hole 39 is located at the rear end of the head body 33. The first screw insertion hole 39 extends through the head body 33 in the tool width direction (Y-axis direction). In other words, the first screw insertion hole 39 extends through the head body 33 in the thickness direction. A plurality of first screw insertion holes 39 are provided. In this embodiment, two first screw insertion holes 39 are formed at intervals in the vertical and front-to-back directions.

[0080] like Figure 2As shown, the head fixing plate 34 protrudes leftward from the approximately center portion of the head body 33 in the front-to-back direction. The head fixing plate 34 is a plate-shaped plate extending 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. In this embodiment, two second screw insertion holes 34a are formed at intervals in the upper and lower portions.

[0081] The second screw insertion hole 34a penetrates the head fixing plate 34 in the axial direction of the tool holder 3. That is, the second screw insertion hole 34a penetrates the head fixing plate 34 in the plate thickness direction thereof.

[0082] Cutting blades

[0083] like Figure 1 and Figure 2 As shown, the cutting insert 2 is axially or cylindrical. The cutting insert 2 of this embodiment is roughly quadrangular. The cutting insert 2 is inserted into the insert mounting seat 35 of the head member 32 from the front and is detachably mounted. The cutting insert 2 has a rake face 22, a flank face 23, and a cutting edge 21.

[0084] The rake face 22 is arranged at the front end portion of the cutting insert 2 and faces upward. The rake face 22 is quadrilateral when viewed from above.

[0085] The flank surface 23 is arranged at the front end portion of the cutting insert 2. The flank surface 23 has a surface facing the front end side (front flank surface), and surfaces facing the left side and the right side (a pair of side flank surfaces).

[0086] The cutting edge 21 is located on a ridge line connecting the rake face 22 and the three flank faces 23. The cutting edge 21 is arranged to protrude from the head body 33 toward the front end, left, and right sides.

[0087] In this embodiment, the cutting edge 21 includes a front edge 21a and a pair of side edges. The front edge 21a extends along the tool width direction (Y-axis direction). In other words, the cutting edge 21 includes a cutting edge portion 21a extending along the tool width direction. The pair of side edges are connected to the two ends of the front edge 21a in the tool width direction, extending from each end toward the rear end. Therefore, when viewed from above, the cutting edge 21 is generally U-shaped.

[0088] The cutting insert 2 of the present embodiment has a pair of a rake face 22 , a flank face 23 , and a cutting edge 21 at both ends in the axial direction of the cutting insert 2 .

[0089] [Fixing screw]

[0090] The fixing screw 8 fixes the head member 32 to the front end portion of the handle 31. A plurality of fixing screws 8 are provided. In this embodiment, the plurality of fixing screws 8 include two first fixing screws 8a and two second fixing screws 8b.

[0091] The first fixing screw 8a fixes the head body 33 to the right side of the handle 31. The first fixing screw 8a is inserted into the first screw insertion hole 39 of the head body 33 and screwed into the first screw hole (not shown) of the handle 31. It is preferable to provide a plurality of first fixing screws 8a.

[0092] The second fixing screw 8b fixes the head fixing plate 34 to the front end surface of the shank 31. The second fixing screw 8b is inserted into the second screw insertion hole 34a of the head fixing plate 34 and screwed into the second screw hole (not shown) of the shank 31. It is preferable to provide a plurality of second fixing screws 8b.

[0093] [Tightening screw]

[0094] The fastening screw 11 has the function of fixing the head component 32 to the upper surface of the front end portion of the shank 31 and fixing the cutting blade 2 to the blade 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 31 while pressing the upper portion of the head body 33 including the upper jaw 36a downward. When the fastening screw 11 is tightened, the connecting portion 38 is elastically deformed by pressing the upper portion of the head body 33 downward, and the upper jaw 36a is displaced downward. As a result, the cutting blade 2 arranged in the blade mounting seat 35 is fastened between the lower surface (pressing surface 35a) of the upper jaw 36a and the upper surface (base surface 35b) of the lower jaw 36b.

[0095] 〔Coolant flow path〕

[0096] The coolant flow path 4 extends throughout the interior of the shank 31 and the interior of the head component 32. Although not shown, the shank flow path extending within the shank 31 of the coolant flow path 4 is connected to a hose or the like of a coolant supply mechanism of the machine tool. The head component flow path 41 extending within the head component 32 of the coolant flow path 4 is specifically arranged within the head body 33. Coolant supplied from the coolant supply mechanism circulates within the coolant flow path 4.

[0097] like Figures 1 to 3 As shown, the head flow path 41 includes a connecting flow path 42 connected to the shank flow path and a jaw flow path 43 communicating with the connecting flow path 42 and extending inside the jaw 36. That is, the coolant flow path 4 includes the connecting flow path 42 and the jaw flow path 43.

[0098] The connecting flow path 42 extends along the tool width direction. A pair of connecting flow paths 42 are provided in the head body 33, spaced apart from each other in the vertical direction. Of the pair of connecting flow paths 42, one connecting flow path 42 located in the upper portion of the head body 33 is an upper connecting flow path 42a, and the other connecting flow path 42 located in the lower portion of the head body 33 is a lower connecting flow path 42b.

[0099] The cross-section of the upper connecting flow channel 42a, perpendicular to the tool width, is circular. The upper connecting flow channel 42a opens on the upper side of the left-facing plate surface 33a of the head body 33. The inner diameter of the upper connecting flow channel 42a decreases as it moves from the opening in the plate surface 33a toward the right. In other words, the cross-sectional area of ​​the upper connecting flow channel 42a decreases as it moves toward the right.

[0100] The cross-section of the lower connecting flow channel 42b, perpendicular to the tool width, is circular. The lower connecting flow channel 42b opens below the left-facing plate surface 33a of the head body 33. The inner diameter of the lower connecting flow channel 42b decreases as it moves rightward from the opening in the plate surface 33a. In other words, the cross-sectional area of ​​the lower connecting flow channel 42b decreases as it moves rightward.

[0101] The jaw flow path 43 extends from its connection point with the connecting flow path 42 in a direction perpendicular to the tool width direction. Specifically, the jaw flow path 43 extends from the connection point with the connecting flow path 42 toward the tool tip, approaching the insert mounting seat 35. In this embodiment, the jaw flow paths 43 are provided as a pair in the head body 33, spaced apart from each other in the vertical direction. The jaw flow path 43 of the pair is located in the upper jaw portion 36a, and the other jaw flow path 43 is located in the lower jaw portion 36b, and is the lower jaw flow path 43b. In other words, a jaw flow path 43 is provided in each jaw portion 36.

[0102] like Figure 3 As shown in FIG8 , the cross-sectional shape of the jaw flow passage 43 varies at each portion in the axial direction (X-axis direction) of the tool holder 3. The "flow passage cross section" of the jaw flow passage 43 referred to in this specification refers to, for example, the flow passage cross section as viewed on a virtual plane perpendicular to the axial direction of the tool holder 3. The cross-sectional shape of the jaw flow passage 43 gradually changes as it moves from the connection portion with the connecting flow passage 42 toward the tool tip.

[0103] Specifically, the jaw flow path 43 includes: a guide flow path portion 44, the flow path cross-section is a longitudinal shape in which the dimension a in the up-down direction (Z-axis direction) is larger than the dimension b in the tool width direction (Y-axis direction); and an injection flow path portion 45, which is connected to the guide flow path portion 44, is arranged closer to the front end side of the tool than the guide flow path portion 44 and closer to the blade mounting seat 35 in the up-down direction, and is open at the end portion on the tool front end side of the jaw 36, and the flow path cross-section is a horizontal shape in which the dimension b in the tool width direction is larger than the dimension a in the up-down direction.

[0104] The flow path sections of the guide flow path section 44 and the injection flow path section 45 are each elliptical. Figure 5A and Figure 5B As shown, the flow path cross section at the connection between the guide flow path portion 44 and the injection flow path portion 45 is circular (substantially a true circle). The flow path cross-sectional area of ​​the guide flow path portion 44 and the flow path cross-sectional area of ​​the injection flow path portion 45 are the same, or the flow path cross-sectional area of ​​the injection flow path portion 45 is smaller than the flow path cross-sectional area of ​​the guide flow path portion 44.

[0105] like Figure 3 、 Figure 4A 、 Figure 4B 、 Figure 7A and Figure 7B As shown, guide flow path portions 44 are provided in each of the pair of jaw flow paths 43. In the flow path cross section of each guide flow path portion 44, the maximum ratio (a / b) of the vertical dimension a to the tool width dimension b is 1.2 or greater and 5.0 or less. Of the pair of guide flow path portions 44, one guide flow path portion 44 included in the upper jaw flow path 43a is an upper guide flow path portion 44a, and the other guide flow path portion 44 included in the lower jaw flow path 43b is a lower guide flow path portion 44b.

[0106] like Figure 3 As shown, the upper guide channel portion 44a extends downward from the connection portion with the upper connecting channel 42a toward the tool tip. In the channel cross section of the upper guide channel portion 44a, the ratio of the vertical dimension a to the tool width dimension b (a / b) decreases toward the tool tip.

[0107] The lower guide channel portion 44b extends upward from the connection portion with the lower connecting channel 42b toward the tool tip. In the channel cross section of the lower guide channel portion 44b, the ratio of the vertical dimension a to the tool width dimension b (a / b) decreases toward the tool tip.

[0108] like Figure 3 、 Figure 6A 、 Figure 6B 、 Figure 8A and Figure 8BAs shown, the jet flow path portion 45 is provided in each of the pair of jaw flow paths 43. In the flow path cross section of the jet flow path portion 45, the maximum ratio of the dimension b in the tool width direction to the dimension a in the vertical direction (b / a) is 1.2 or greater and 5.0 or less. Of the pair of jet flow path portions 45, one jet flow path portion 45 included in the upper jaw flow path 43a is the upper jet flow path portion 45a, and the other jet flow path portion 45 included in the lower jaw flow path 43b is the lower jet flow path portion 45b.

[0109] like Figure 3 As shown, the upper jet flow path portion 45a extends downward from the connection with the upper guide flow path portion 44a toward the front end of the tool. In the flow path cross section of the upper jet flow path portion 45a, the ratio (b / a) of the dimension b in the tool width direction to the dimension a in the vertical direction increases toward the front end of the tool. The front end portion of the upper jet flow path portion 45a opens on the surface of the upper jaw portion 36a facing the front end. The front end portion of the upper jet flow path portion 45a, i.e., the opening (upper jet port), is positioned adjacent to the upper side of the insert mounting seat 35. The opening of the upper jet flow path portion 45a opens toward the rake face 22 and cutting edge 21 of the cutting insert 2.

[0110] The lower jet flow path portion 45b extends upward from its connection with the lower guide flow path portion 44b toward the tool's front end. In the flow path cross section of the lower jet flow path portion 45b, the ratio (b / a) of the dimension b in the tool width direction to the dimension a in the vertical direction increases toward the tool's front end. The front end portion of the lower jet flow path portion 45b opens on the surface of the lower jaw portion 36b facing the front end. The front end portion of the lower jet flow path portion 45b, i.e., the opening (lower jet port), is positioned adjacent to the bottom side of the insert mounting seat 35. The opening of the lower jet flow path portion 45b opens toward the flank surface 23 and cutting edge 21 of the cutting insert 2.

[0111] [Effects of this embodiment]

[0112] According to the grooving tool 1 of the present embodiment described above, even if the jaw portion 36 to which the cutting insert 2 is secured is in the shape of a curved plate whose thickness decreases as it moves away from the insert mounting seat 35 in the vertical direction, coolant can be sprayed stably and with high precision toward the vicinity of the cutting edge 21 from the jaw portion flow path 43 extending within the jaw portion 36.

[0113] In detail, the flow path cross section of the jet flow path portion 45 opened at the end portion on the tool front end side of the jaw portion 36 in the jaw flow path 43 is 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, the jet flow path portion 45 can be arranged in the thicker plate portion of the jaw portion 36, that is, the portion close to the insert mounting seat 35, and the coolant can be stably sprayed from the jet flow path portion 45 to the entire area of ​​the cutting edge 21 including at least the cutting edge portion 21a over a wide range.

[0114] Furthermore, the flow path cross-section of the guide flow path portion 44 in the jaw flow path 43 is elongated, with the vertical dimension a being greater than the tool width dimension b. This allows the guide flow path portion 44 to be positioned in a thinner portion (thin-walled portion) of the jaw 36, vertically away from the insert mounting seat 35. Specifically, the guide flow path portion 44 can be positioned in the thin-walled portion of the jaw 36 while maintaining a large flow cross-sectional area, i.e., while ensuring the flow rate of coolant ejected from the jaw 36. This facilitates the vertical inclination of the flow path from the guide flow path portion 44 to the ejection flow path portion 45 toward the tool tip. Consequently, the cutting edge 21 can be positioned near an extension of the opening (injection port) of the ejection flow path portion 45, enabling high-precision and efficient coolant supply to the vicinity of the cutting edge 21.

[0115] Furthermore, in the present embodiment, a pair of jaws 36 are provided on the upper and lower sides of the insert mounting seat 35 , and a jaw flow path 43 is provided in each jaw 36 .

[0116] In this case, coolant can be sprayed from the jaw flow path 43 (upper jaw flow path 43a) of the upper jaw portion 36a, which is located above the insert mounting seat 35, of the pair of jaw portions 36, through the rake face 22 of the cutting insert 2 and toward the vicinity of the cutting edge 21. Furthermore, coolant can be sprayed from the jaw flow path 43 (lower jaw flow path 43b) of the lower jaw portion 36b, which is located below the insert mounting seat 35, of the pair of jaw portions 36, through the flank face 23 of the cutting insert 2 and toward the vicinity of the cutting edge 21. Consequently, coolant can be supplied more stably to the vicinity of the cutting edge 21.

[0117] Furthermore, in this embodiment, the flow path cross-sectional area of ​​the injection flow path portion 45 is smaller than the flow path cross-sectional area of ​​the guide flow path portion 44 , or the flow path cross-sectional area of ​​the guide flow path portion 44 and the flow path cross-sectional area of ​​the injection flow path portion 45 are the same.

[0118] For example, unlike the present embodiment, if the flow path cross-sectional area of ​​the injection flow path portion 45 is larger than the flow path cross-sectional area of ​​the guide flow path portion 44, when the coolant flows from the guide flow path portion 44 into the injection flow path portion 45, a decrease in flow velocity and pressure loss may sometimes occur due to the increase in the flow path cross-sectional area.

[0119] On the other hand, according to this embodiment, when the coolant flows from the guide flow path portion 44 into the injection flow path portion 45, a decrease in flow velocity and pressure loss can be suppressed. The flow velocity of the coolant flowing through the injection flow path portion 45 is stably increased, and the coolant injected from the injection flow path portion 45 can be used to efficiently cool the vicinity of the cutting edge 21.

[0120] Furthermore, 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.

[0121] When the ratio (a / b) is 1.2 or greater, the flow path cross-section of the guide flow path portion 44 maintains a stable longitudinally elongated shape, making it easier to position the guide flow path portion 44 within the thin-walled portion of the jaw portion 36. Consequently, the effects of this embodiment described above can be more stably achieved. When the ratio (a / b) is 5.0 or less, problems such as increased pressure loss caused by an excessively longitudinally flattened flow path cross-section can be suppressed.

[0122] Furthermore, in the present embodiment, in the flow path cross section of the injection 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.

[0123] When the ratio (b / a) is 1.2 or greater, the cross-sectional shape of the injection flow path portion 45 is stably horizontally elongated, making it easier to stably spray coolant from the injection flow path portion 45 over the entire area of ​​the cutting edge 21. Consequently, the effects of this embodiment described above can be more stably achieved. When the ratio (b / a) is 5.0 or less, it is possible to prevent problems such as coolant being sprayed in a mist due to an excessively horizontally flat cross-sectional shape of the flow path, causing the coolant to spread unnecessarily to areas other than the cutting edge 21.

[0124] [Other structures included in the present invention]

[0125] The present invention is not limited to the above-described embodiment, and for example, as described below, structural changes and the like can be made without departing from the gist of the present invention.

[0126] In the above embodiment, an example is given in which the flow path cross section of each of the guide flow path portion 44 and the injection flow path portion 45 is elliptical, but the present invention is not limited thereto.

[0127] Figure 9 to Figure 1 3 shows a modified example of the head part 32 of the grooving tool 1 described in the above embodiment. In this modified example, the flow path cross-sections of the guide flow path portion 44 and the injection flow path portion 45 are polygonal. In the example shown in the figure, the flow path cross-sections of the guide flow path portion 44 and the injection flow path portion 45 are triangular. In addition to triangles, they can also be quadrilaterals (diamond shapes), pentagons, hexagons, etc. In this modified example, as shown in FIG. Figure 12A and Figure 12B As shown, the flow path cross section at the connection portion between the guide flow path portion 44 and the injection flow path portion 45 is an equilateral triangle.

[0128] like Figure 11A and Figure 11BAs shown, 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.

[0129] like Figure 13A and Figure 13B As shown, in the flow path cross section of the injection 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.

[0130] like Figure 10 As shown, in the connecting flow channel 42 , the shape of the flow channel cross section perpendicular to the tool width direction is polygonal, specifically, triangular.

[0131] In this modification, the same effects as those of the above embodiment can be obtained. In addition, as shown in the figure of this modification, only one set of the connecting flow path 42 and the jaw flow path 43 of the coolant flow path 4 can be provided in the head member 32.

[0132] Furthermore, in the aforementioned embodiment, an example is given in which, when viewed from the front end side of the tool, the upper jaw 36a is bent so as to be located on the right side (+Y side) as it moves from the blade mounting seat 35 toward the upper side (+Z side), and the lower jaw 36b is bent so as to be located on the right side as it moves from the blade mounting seat 35 toward the lower side (-Z side), but the present invention is not limited to this.

[0133] Although not specifically shown in the figure, when viewed from the front end side of the tool, the upper jaw 36a can be bent to be located on the left side (-Y side) as it moves from the blade mounting seat 35 toward the upper side, and the lower jaw 36b can be bent to be located on the left side as it moves from the blade mounting seat 35 toward the lower side.

[0134] Furthermore, in the aforementioned embodiment, an example is given in which a pair of jaws 36 having jaw flow passages are provided on the upper and lower sides of the insert mounting seat 35, but the present invention is not limited thereto. Alternatively, only one jaw having a jaw flow passage may be provided on either the upper or lower side of the insert mounting seat 35. In this case, the cutting insert 2 is secured to the insert mounting seat by being secured between the jaw without a jaw flow passage and the jaw having a jaw flow passage.

[0135] Although not shown, the jaw portion without the jaw flow path may be formed separately from the head member 32. In this case, the jaw portion without the jaw flow path may be composed of a fastening member that can fasten the cutting insert 2 by sliding or the like close to the jaw portion with the jaw flow path.

[0136] The present invention may combine the various structures described in the aforementioned embodiments and modifications, and may add, omit, replace, or otherwise modify the structures, without departing from the spirit of the present invention. Furthermore, the present invention is not limited by the aforementioned embodiments, etc., but is limited only by the claims.

[0137] Industrial applicability

[0138] According to the grooving tool of the present invention, the coolant can be sprayed near the cutting edge with high precision while ensuring the coolant flow rate, and therefore has industrial applicability.

[0139] Explanation of symbols

[0140] 1 Grooving tool 2 Cutting insert

[0141] 3 Tool holder 4 Coolant flow path

[0142] 21 Cutting edge 21a Front edge (cutting edge)

[0143] 35 Blade mounting seat 36 Jaw

[0144] 43 Jaw flow path 44 Guide flow path section

[0145] 45 Injection flow path

[0146] a Dimensions of the flow path cross section in the vertical direction

[0147] b Dimensions of the flow path section in the tool width direction

Claims

1. A grooving tool comprising: a cutting insert having a cutting edge; a toolholder holding the cutting insert; and A coolant flow path extends inside the tool holder, The cutting edge has a cutting edge portion extending along the tool width direction, The tool holder has: a blade mounting seat for arranging the cutting blade; and A pair of jaws are arranged on the upper and lower sides of the insert mounting seat and contact the cutting insert from the upper and lower directions. At least one of the jaws is in the shape of a plate extending in a direction perpendicular to the width direction of the tool, and is curved when viewed from the front end side of the tool, and the plate thickness becomes thinner as it moves away from the blade mounting seat in the upward or downward direction. The coolant flow path includes a jaw flow path extending inside the at least one jaw, The jaw flow path has: a flow guide portion; and The injection flow path portion is connected to the guide flow path portion, is arranged closer to the tool front end side than the guide flow path portion and closer to the insert mounting seat in the vertical direction, and is open at the end portion of the jaw portion on the tool front end side. The flow path cross section of the guide flow path portion is a longitudinal shape whose dimension in the vertical direction is larger than that in the tool width direction. The flow path cross section of the injection flow path portion has a horizontally long shape in which a dimension in the tool width direction is larger than a dimension in the vertical direction.

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

3. The grooving tool according to claim 1 or 2, wherein: The flow path cross-sectional area of ​​the injection flow path portion is smaller than the flow path cross-sectional area of ​​the guide flow path portion.

4. The grooving tool according to claim 1 or 2, wherein: The flow path cross-sectional area of ​​the guide flow path portion and the flow path cross-sectional area of ​​the injection flow path portion are the same as each other.

5. The grooving tool according to claim 1 or 2, wherein: The maximum value of the ratio a / b of the vertical dimension a to the tool width dimension b in the flow path section of the guide flow path portion is 1.2 or more and 5.0 or less, and the ratio a / b of the guide flow path portion decreases toward the tool tip.

6. The grooving tool according to claim 1 or 2, wherein: In the flow path section of the injection flow path portion, a maximum value of a ratio b / a of a tool width dimension b to a vertical dimension a is 1.2 or more and 5.0 or less, and the ratio b / a increases toward the tool tip.

7. The grooving tool according to claim 1 or 2, wherein: The cross section of each flow path of the guide flow path portion and the injection flow path portion is elliptical.

8. The grooving tool according to claim 1 or 2, wherein: The cross section of each flow path of the guide flow path portion and the injection flow path portion is polygonal.

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