A cutting tool with indexable inserts

Abstract

The present invention discloses a cutting tool with indexable inserts, which includes a tool body, a clamping member and indexable inserts. A blade mounting groove is formed at the front end of the tool body, and a clamping member mounting hole is formed in the middle. A center positioning hole is formed on the indexable insert and is installed in the blade mounting groove. The clamping member is matched with the clamping member mounting hole. The rear end of the tool body is matched with the rear end of the clamping member through an inclined surface. A protruding positioning plane and a columnar protrusion are provided on the lower surface of the front end of the clamping member. The columnar protrusion is located below the protruding positioning plane. An arc-shaped spring piece is provided inside the center positioning hole. The columnar protrusion applies a clamping force to the hole wall of the center positioning hole under the cooperation of the arc-shaped spring piece, and the protruding positioning plane applies a clamping force to the upper positioning surface of the indexable insert. The present invention has the advantages of realizing double fixation of the blade, being stable and reliable, and being convenient for loading and unloading.

Description

Technical Field

[0001] The present invention mainly relates to the field of metal cutting, and in particular to a cutting tool with indexable inserts. Background Art

[0002] Cutting tools with indexable inserts are widely used. The indexable inserts of such tools can be indexed and reused. Therefore, it is very important to achieve stable and reliable clamping and fixing of indexable inserts. There are various structures of indexable insert fixing structures in the prior art.

[0003] For example, Chinese Patent Document CN102348522A discloses a toolholder fixture assembly and a pressing plate for a blade. The main deficiencies are as follows: interference occurs between the root of the columnar protruding part at the front end of the clamping part and the edge of the inner hole of the blade. Therefore, the columnar protruding part needs to be designed to form a certain angle with the lower surface at the front end of the clamping part, and an avoidance groove often needs to be designed at the root. This design causes stress concentration at the root of the columnar protruding part and is prone to fracture. Moreover, the columnar protruding part and the hole wall of the central hole of the blade are in point contact and are easily worn, resulting in a change in the clamping force.

[0004] Chinese Patent Document CN101391311A discloses a special toolholder for indexable inserts, including a toolholder, a clamping bolt, and a clamping part. The toolholder is provided with an indexable insert mounting part and a bolt mounting hole. The clamping part is placed above the toolholder. The clamping part is provided with a through hole. The clamping bolt is sleeved in the through hole and is threadedly connected to the bolt mounting hole. A compression spring is sleeved on the clamping bolt. The compression spring is located between the toolholder and the clamping part. A first inclined surface group is provided at the part where the rear end of the toolholder is connected to the clamping part. A second inclined surface group that can engage with the first inclined surface group on the toolholder is provided at the part where the rear end of the clamping part is connected to the toolholder. The first inclined surface group includes two first inclined surfaces that form an angle α with each other. The second inclined surface group includes two second inclined surfaces that form an angle β with each other. The ranges of the angle α and the angle β are between 110° and 150°, and the relationship between the two is 0° ≤ |α - β| ≤ 5°. This special toolholder for indexable inserts ensures that the clamped indexable insert is pushed downward and inward, and firmly clamps the indexable insert on the toolholder. The deficiencies of this technical solution are as follows: the area of the positioning surface on the lower surface at the front end of the clamping part is small, and the shapes of the top positioning surfaces of various blades are diverse, scattered and irregular. There is a mismatch between the positioning surface of the clamping part and the positioning surface of the blade, and even a non-contact state may occur, affecting the clamping reliability.

[0005] In addition, in actual production, due to blade production and design factors, the blade thickness has a certain fluctuation range. The thickness of the flat non-grooved blade is about 4.7 mm. For grooved blades, due to different enterprises and different groove design characteristics, the designed blade thickness is between 4.8 - 5.16 mm. Therefore, in actual application, due to different blade thicknesses, there may be only one place where the top surface of the blade and the inner hole wall of the blade are subjected to clamping force, making it difficult to achieve double clamping. There may also be a situation where the blade cannot be in good contact with the positioning surfaces on both sides of the tool groove. This is a common problem in the existing technology. Summary of the Invention

[0006] The technical problem to be solved by the present invention is to overcome the deficiencies of the existing technology and provide a cutting tool with indexable inserts that can achieve double fixation of the inserts, is stable and reliable, and is convenient for loading and unloading.

[0007] To solve the above technical problems, the present invention adopts the following technical solutions:

[0008] A cutting tool with indexable inserts, comprising a tool body, a clamping member, and an indexable insert. The front end of the tool body is provided with a blade mounting groove, and the middle part is provided with a clamping member mounting hole. The indexable insert is provided with a central positioning hole and is installed in the blade mounting groove. The clamping member is matched with the clamping member mounting hole. The rear end of the tool body is matched with the rear end of the clamping member through an inclined surface. The lower surface of the front end of the clamping member is provided with a protruding positioning plane and a columnar protrusion. The columnar protrusion is located below the protruding positioning plane. An arc-shaped spring piece is arranged inside the central positioning hole. The columnar protrusion applies a clamping force to the inner wall of the central positioning hole under the cooperation of the arc-shaped spring piece, and the protruding positioning plane applies a clamping force to the upper positioning surface of the indexable insert.

[0009] As a further improvement of the above technical solution:

[0010] During the process of the clamping member moving downward and backward under the cooperation of the inclined surface with the tool body, the columnar protrusion first contacts and compresses the arc-shaped spring piece, pushing the indexable insert to fit with the two side positioning surfaces of the blade mounting groove, and then the protruding positioning plane fits with the upper positioning surface of the indexable insert.

[0011] A through hole is provided in the middle of the clamping member, and a fixing bolt is arranged in the through hole. The lower end of the fixing bolt is threadedly connected with the clamping member mounting hole. A compression spring is sleeved on the fixing bolt. The compression spring is located between the clamping member and the clamping member mounting hole. During the tightening process of the fixing bolt, the clamping member moves downward and backward.

[0012] There is an included angle α between the connecting line of the center points of the clamping member mounting hole and the central positioning hole and the angular bisector between the two side positioning surfaces of the blade mounting groove, and it satisfies: -5° ≤ α ≤ 5°.

[0013] The aperture diameter of the central positioning hole of the indexable insert is d. The arc-shaped spring piece is a circular arc thin sheet made of metal, with a diameter of R1 and a chord length of L2, and satisfies: R1 > d, L2 < d.

[0014] The aperture diameter of the central positioning hole of the indexable insert is d. The inner edge of the protruding positioning plane is arc-shaped, with a diameter of R2. The inscribed circle diameter of the indexable insert is C, and should satisfy: d < R2 < C.

[0015] The columnar protrusion is a cylinder, a semi-cylinder or an ellipsoid cylinder.

[0016] There is an arc transition between the root of the columnar protrusion and the protruding positioning plane, and the arc radius is R. The chamfer depth of the central positioning hole is L1, and should satisfy: R < L1.

[0017] The columnar protrusion is arranged perpendicular to the protruding positioning plane.

[0018] A cutter pad is also provided in the blade mounting groove. The bottom surface of the blade mounting groove is provided with a cutter pad mounting hole. The cutter pad is mounted below the indexable insert by cooperating with the cutter pad mounting hole through a bolt.

[0019] Compared with the prior art, the advantages of the present invention are as follows:

[0020] For the cutting tool with an indexable insert of the present invention, a protruding positioning plane and a columnar protrusion are provided on the lower surface of the front end of the clamping member, and the columnar protrusion is located below the protruding positioning plane. An arc-shaped spring piece is provided inside the central positioning hole. During the process of the clamping member moving downward and backward to clamp the indexable insert, it first pushes the indexable insert to move backward to accurately guide and position the indexable insert through the two side positioning surfaces of the blade mounting groove, and then presses the indexable insert downward through the protruding positioning plane for positioning, thus realizing double fixation. During the process of the clamping member pushing the indexable insert to move backward, the arc-shaped spring piece can be adaptively pressed against the inner wall of the central positioning hole of the indexable insert, and the two sides are in line contact or arc surface contact, with uniform and stable force and reliable performance. The arc-shaped spring piece has a large compression space, and the thickness of the indexable insert has a large selection range, and it can avoid interference between the columnar protrusion and the chamfer of the central positioning hole of the indexable insert. There is no need to design an avoidance groove at the joint of the protruding positioning plane and the columnar protrusion on the clamping member, reducing the risk of fracture of the clamping member due to stress concentration and making the clamping member more stable and reliable. In addition, the structure of the protruding positioning plane can be set according to the structure of the upper positioning surface of the indexable insert, which can ensure effective coverage of the upper positioning surface of the indexable insert, making the clamping stable and reliable and the pressure distribution uniform. Description of the Drawings

[0021] Figure 1It is a schematic structural view of a cutting tool with indexable inserts according to the present invention.

[0022] Figure 2 It is an exploded perspective view of a cutting tool with indexable inserts according to the present invention.

[0023] Figure 3 It is a top view of a cutting tool with indexable inserts according to the present invention.

[0024] Figure 4 It is the initial state of the installation of the indexable insert according to the present invention Figure 1 A - A sectional view.

[0025] Figure 5 It is when the indexable insert is in contact with the side positioning surface of the insert mounting groove during the installation process according to the present invention Figure 1 A - A sectional view.

[0026] Figure 6 It is the state when the indexable insert is clamped during the installation process according to the present invention Figure 1 A - A sectional view.

[0027] Figure 7 It is the front view of the clamping member of a cutting tool with indexable inserts according to the present invention.

[0028] Figure 8 It is Figure 7 View from direction B.

[0029] Figure 9 It is a schematic structural view of the indexable insert of a cutting tool with indexable inserts according to the present invention.

[0030] Figure 10 It is Figure 9 View from direction C - C.

[0031] Figure 11 It is a schematic structural view of the arc spring piece of a cutting tool with indexable inserts according to the present invention.

[0032] In the figure, each reference numeral represents:

[0033] 1, tool body; 2, clamping member; 21, protruding positioning plane; 22, columnar protrusion; 23, rear end inclined surface; 24, fixing bolt; 25, compression spring; 3, indexable insert; 31, center positioning hole; 32, upper positioning surface; 4, insert mounting groove; 41, side positioning surface; 42, cutter pad mounting hole; 5, clamping member mounting hole; 6, arc spring piece; 7, cutter pad. Detailed implementation manners

[0034] The following will further elaborate on the present invention in detail with reference to the accompanying drawings of the specification and specific embodiments.

[0035] Figures 1 to 11 An embodiment of the split drilling tool of the present invention is shown. The cutting tool with indexable inserts in this embodiment includes a tool body 1, a clamping member 2, and an indexable insert 3. A blade mounting groove 4 is provided at the front end of the tool body 1, and a clamping member mounting hole 5 is provided in the middle. A center positioning hole 31 is provided on the indexable insert 3 and is installed in the blade mounting groove 4. The clamping member 2 is matched with the clamping member mounting hole 5. The rear end of the tool body 1 and the rear end of the clamping member 2 are matched through an inclined surface. There is an included angle α between the connecting line of the center points of the clamping member mounting hole 5 and the center positioning hole 31 and the angular bisector between the two side positioning surfaces 41 of the blade mounting groove 4, and it satisfies: -5° ≤ α ≤ 5°. On the lower surface of the front end of the clamping member 2, there are a protruding positioning plane 21 and a columnar protrusion 22. The columnar protrusion 22 is located below the protruding positioning plane 21. An arc-shaped spring piece 6 is provided inside the center positioning hole 31. The columnar protrusion 22 applies a clamping force to the inner wall of the center positioning hole 31 under the cooperation of the arc-shaped spring piece 6, and the protruding positioning plane 21 applies a clamping force to the upper positioning surface 32 of the indexable insert 3. During the process of the clamping member 2 moving downward and backward to clamp the indexable insert 3, the columnar protrusion 22 first contacts the arc-shaped spring piece 6 and pushes the indexable insert 3 to move backward, so as to accurately guide and position the indexable insert 3 through the two side positioning surfaces 41 of the blade mounting groove 4, and then press the indexable insert 3 downward through the protruding positioning plane 21 for positioning, thereby realizing double fixation of the indexable insert 3. During the process of the clamping member 2 pushing the indexable insert 3 to move backward, the arc-shaped spring piece 6 can be adaptively pressed against the inner wall of the center positioning hole 31 of the indexable insert 3, and the two sides are in line contact or arc surface contact, with uniform and stable force, and the arc-shaped spring piece 6 has a large compression space, and the thickness of the indexable insert 3 has a large selection range, avoiding the indexable insert 3 being unable to be clamped due to thickness difference, and can avoid the interference between the columnar protrusion 22 and the chamfer of the center positioning hole 31 of the indexable insert 3. There is no need to design a relief groove at the joint of the protruding positioning plane 21 and the columnar protrusion 22 on the clamping member 2, reducing the risk of the clamping member 2 breaking due to stress concentration, making the clamping member 2 more stable and reliable. In addition, the structure of the protruding positioning plane 21 can be set according to the structure of the upper positioning surface 32 of the indexable insert 3, which can ensure effective coverage of the upper positioning surface 32 of the indexable insert 3, making the clamping stable and reliable and the pressure distribution uniform.

[0036] In this embodiment, during the process of the clamping member 2 moving downward and backward under the cooperation with the inclined surface of the tool body 1, the columnar protrusion 22 first contacts and compresses the arc-shaped spring piece 6, pushing the indexable insert 3 to fit with the two side positioning surfaces 41 of the blade mounting groove 4, and then the protruding positioning plane 21 fits with the upper positioning surface 32 of the indexable insert 3.

[0037] In this embodiment, a through hole is formed in the middle of the clamping member 2. A fixing bolt 24 is arranged in the through hole. The lower end of the fixing bolt 24 is threadedly connected to the clamping member mounting hole 5. A compression spring 25 is sleeved on the fixing bolt 24. The compression spring 25 is located between the clamping member 2 and the clamping member mounting hole 5. During the tightening process of the fixing bolt 24, the rear inclined surface 23 of the clamping member 2 moves along the inclined surface of the tool body 1, realizing the downward and backward movement of the clamping member 2.

[0038] There is an included angle α between the connecting line of the center points of the clamping member mounting hole 5 and the center positioning hole 31 and the angular bisector between the two side positioning surfaces 41 of the blade mounting groove 4, and it satisfies: -5° ≤ α ≤ 5°, so as to ensure that the pressure distribution generated by the clamping member 2 on the center positioning hole 31 is uniform, and it can also avoid cracks or fractures caused by unilateral stress concentration on the protruding positioning plane 21. In this embodiment, α = 0.

[0039] In this embodiment, the diameter of the center positioning hole 31 of the indexable insert 3 is d. The arc-shaped spring piece 6 is a circular arc thin sheet made of metal, with a diameter of R1 and a chord length of L2, and it satisfies: R1 > d, L2 < d, to ensure that the arc-shaped spring piece 6 can gradually generate a pressing force on the center positioning hole 31 during the process of the columnar protrusion 22 pressing the arc-shaped spring piece 6. In this embodiment, R1 = 1.3d, L2 = 0.7d.

[0040] The diameter of the center positioning hole 31 of the indexable insert 3 is d. The inner edge of the protruding positioning plane 21 is arc-shaped and has a diameter of R2. The inscribed circle diameter of the indexable insert 3 is C, and it should satisfy: d < R2 < C, to ensure the effective contact area between the protruding positioning plane 21 and the indexable insert 3. In this embodiment, R2 = 1.4d, C = 2d.

[0041] The columnar protrusion 22 is a cylinder, a semi-cylinder or an elliptical cylinder. In this embodiment, the columnar protrusion 22 is a cylinder with a diameter of Φ, and Φ < d. If a semi-cylinder is set, the diameter Φ should also satisfy Φ < d. If it is set as an elliptical cylinder, its inscribed circle diameter should also be less than d.

[0042] There is an arc transition between the root of the columnar protrusion 22 and the protruding positioning plane 21 to ensure the strength of the root of the columnar protrusion 22, and the arc radius is R. The chamfer depth of the center positioning hole 31 is L1, and it should satisfy: R < L1, to avoid interference between the arc transition and the chamfer of the center positioning hole 31. In this embodiment, R = 0.8L1.

[0043] In this embodiment, the columnar protrusion 22 is arranged perpendicular to the protruding positioning plane 21.

[0044] In this embodiment, a tool pad 7 is further arranged in the blade mounting groove 4. A tool pad mounting hole 42 is arranged on the bottom surface of the blade mounting groove 4. The tool pad 7 is installed below the indexable insert 3 by cooperating with the tool pad mounting hole 42 through a bolt.

[0045] Although the present invention has been disclosed above in preferred embodiments, it is not intended to limit the present invention. Any person skilled in the art can make many possible changes and modifications to the technical solution of the present invention by using the technical content disclosed above, or modify it into an equivalent embodiment with equivalent changes. Therefore, any simple modification, equivalent change and modification made to the above embodiments based on the technical essence of the present invention without departing from the technical solution of the present invention shall fall within the scope of protection of the technical solution of the present invention.

Claims

1. A cutting tool with indexable inserts, comprising a tool body (1), a clamping member (2) and an indexable insert (3). A blade mounting groove (4) is provided at the front end of the tool body (1), and a clamping member mounting hole (5) is provided in the middle. A central positioning hole (31) is provided on the indexable insert (3), and the indexable insert (3) is mounted in the blade mounting groove (4). The clamping member (2) is matched with the clamping member mounting hole (5). The rear end of the tool body (1) is in inclined surface fit with the rear end of the clamping member (2), and it is characterized in that: A protrusion positioning plane (21) and a columnar protrusion (22) are provided on the lower surface of the front end of the clamping member (2). The columnar protrusion (22) is located below the protrusion positioning plane (21). An arc-shaped spring piece (6) is provided inside the central positioning hole (31). The columnar protrusion (22) applies a clamping force to the hole wall of the central positioning hole (31) in cooperation with the arc-shaped spring piece (6), and the protrusion positioning plane (21) applies a clamping force to the upper positioning surface (32) of the indexable insert (3).

2. The cutting tool with indexable inserts according to claim 1, wherein: During the downward and backward movement of the clamping member (2) under the cooperation with the inclined surface of the tool body (1), the columnar protrusion (22) first contacts and compresses the arc-shaped spring piece (6), pushing the indexable insert (3) to fit with the two side positioning surfaces (41) of the blade mounting groove (4). Subsequently, the protrusion positioning plane (21) fits with the upper positioning surface (32) of the indexable insert (3).

3. The cutting tool with indexable inserts according to claim 1, characterized in that: A through hole is provided in the middle of the clamping member (2). A fixing bolt (24) is provided in the through hole. The lower end of the fixing bolt (24) is threadedly connected to the clamping member mounting hole (5). A compression spring (25) is sleeved on the fixing bolt (24). The compression spring (25) is located between the clamping member (2) and the clamping member mounting hole (5). During the tightening process of the fixing bolt (24), the clamping member (2) moves downward and backward.

4. The cutting tool with indexable inserts according to claim 1, characterized in that: There is an included angle α between the connecting line of the center points of the clamping member mounting hole (5) and the central positioning hole (31) and the angular bisector between the two side positioning surfaces (41) of the blade mounting groove (4), and it satisfies: -5° ≤ α ≤ 5°.

5. The cutting tool with indexable inserts according to any one of claims 1 to 4, characterized in that: The aperture of the central positioning hole (31) of the indexable insert (3) is d. The arc-shaped spring piece (6) is a circular arc thin sheet made of metal, with a diameter of R1 and a chord length of L2, and it satisfies: R1 > d, L2 < d.

6. The cutting tool with indexable inserts according to any one of claims 1 to 4, characterized in that: The aperture of the central positioning hole (31) of the indexable insert (3) is d. The inner edge of the protrusion positioning plane (21) is arc-shaped and has a diameter of R2. The inscribed circle diameter of the indexable insert (3) is C, and it should satisfy: d < R2 < C.

7. A cutting tool with indexable inserts according to any one of claims 1 to 4, characterized in that: The columnar protrusion (22) is a cylinder, a semi-cylinder or an elliptical cylinder.

8. The cutting tool with indexable inserts according to claim 7, characterized in that: There is an arc transition between the root of the columnar protrusion (22) and the protrusion positioning plane (21), and the arc radius is R. The chamfer depth of the central positioning hole (31) is L1, and it should satisfy: R < L1.

9. The cutting tool with indexable inserts according to claim 7, characterized in that: The columnar protrusion (22) is arranged perpendicular to the protrusion positioning plane (21).

10. The cutting tool with indexable inserts according to any one of claims 1 to 4, characterized in that: A cutter pad (7) is further provided in the blade mounting groove (4). A cutter pad mounting hole (42) is provided on the bottom surface of the blade mounting groove (4). The cutter pad (7) is mounted below the indexable insert (3) by cooperating with the cutter pad mounting hole (42) through a bolt.

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