Cutting inserts and cutting tools

Abstract

The present invention provides a cutting blade and a cutting tool. The cutting blade extends from the rear end to the front end along the rotation center axis, and has a first area and a second area divided by the rotation center axis; the cutting blade includes a first restraining surface and a second restraining surface, a peripheral portion, a through hole and a cutting edge; the cutting edge has a front cutting edge intersecting the rotation center axis and a first cutting edge located in the first area of ​​the peripheral portion; the first restraining surface has a cooling groove extending from the rear end side to the front end side; the cooling groove includes an inlet section, a transition section and a plurality of injection sections; from the front view of the first restraining surface, the plurality of injection sections are smoothly connected to the transition section, and have a first injection section extending toward the front cutting edge. The present invention can reduce the flow pressure loss of the coolant sprayed toward the front cutting edge, improve the cooling effect of the coolant, and thus improve the blade life and the workpiece processing surface quality.

Description

Technical Field

[0001] The present invention relates to the technical field of cutting tools, and in particular to a cutting insert and a cutting tool. Background Art

[0002] In metal material cutting, end mills are often used for profiling, curved surface processing, etc. End mills are often processed in a semi-enclosed environment, which has problems such as difficulty in chip discharge and chip biting on the cutting edge. These factors will reduce the tool life and affect the surface quality of the workpiece. Setting up a cooling system can solve the above problems to varying degrees. However, the existing ones still have certain shortcomings.

[0003] Chinese invention patent CN101695770A discloses a blade finishing milling cutter with an internal cooling system, wherein a through hole is arranged along the central axis of the tool handle, and a cooling groove and a jet nozzle are arranged on the blade. The through hole of the tool handle is connected to the cooling groove of the blade, and the cutting edge is cooled through the jet nozzle.

[0004] In this solution, the channel connecting the cooling channel inlet and the injection port surrounds the central through hole. When the coolant reaches the channel inlet of the blade, it is immediately blocked by the cylinder formed by the through hole and is divided into two streams. After filling the channel, it is sprayed to the outlet. In this process, both the flow rate and pressure are lost to a certain extent. Summary of the invention

[0005] The object of the present invention is to provide a cutting insert with a cooling groove to improve the tool life and the surface quality of the workpiece.

[0006] Another object of the present invention is to provide a cutting tool comprising the above-mentioned cutting insert.

[0007] In order to solve the above technical problems, the present invention adopts the following technical solutions:

[0008] According to one aspect of the present invention, there is provided a cutting blade extending from the rear end to the front end along the rotation center axis; the cutting blade has a first area and a second area divided by the rotation center axis; the cutting blade has: two restraining surfaces having a first restraining surface and a second restraining surface relative to each other; a peripheral portion located between the two restraining surfaces; a through hole formed between the two restraining surfaces; a cutting edge formed on the front end side; the cutting edge has: a front end cutting edge intersecting the rotation center axis; a first cutting edge located in the first area of ​​the peripheral portion; the peripheral portion also has a cutting edge located in the second area of ​​the peripheral portion a rear angle surface between a cutting edge and the first restraining surface; the first restraining surface has a cooling groove extending from the rear end side to the front end side; the cooling groove includes: an entrance section extending from the rear end side; a transition section connected to an end of the entrance section close to the through hole and extending along the through hole in a curved manner; a plurality of injection sections respectively connected to the transition sections and respectively extending from the transition sections to the ridges where the first restraining surface intersects the outer periphery; from the front view of the first restraining surface, the plurality of injection sections are smoothly connected to the transition section and have a first injection section extending toward the front cutting edge.

[0009] According to another aspect of the present invention, there is provided a cutting tool, comprising a shank and the cutting blade as described above, wherein the shank is provided with a coolant channel; the cutting blade is mounted at the front end of the shank, and the cooling groove of the cutting blade is connected to the coolant channel.

[0010] It can be seen from the above technical scheme that the present invention has at least the following advantages and positive effects: the cutting blade of the present invention is provided with a cooling groove on the restraint surface, and the cooling groove has multiple injection sections to cool the cutting edge, wherein the first injection section of the cooling groove extending toward the front cutting edge is smoothly connected with the transition section, so that the flow pressure loss of the coolant injected from the first injection section toward the front cutting edge is greatly reduced compared with the prior art, thereby improving the effect of coolant injection, thereby facilitating heat dissipation and chip discharge at the front cutting edge, and improving the workpiece processing surface quality and cutting blade life. BRIEF DESCRIPTION OF THE DRAWINGS

[0011] Figure 1 It is a three-dimensional structural schematic diagram of an embodiment of a cutting blade of the present invention.

[0012] Figure 2 and Figure 3 yes Figure 1 Front view of .

[0013] Figure 4 yes Figure 2 Schematic diagram of the CC section.

[0014] Figure 5 yes Figure 2 Schematic diagram of the middle DD section.

[0015] Figure 6 yes Figure 2 Schematic diagram of the EE cross section.

[0016] Figure 7 yes Figure 2 Middle GG section view.

[0017] Figure 8 is a cross-sectional view of another embodiment of a cutting insert, the view direction is referenced Figure 7 .

[0018] Fig. 9 It is a cross-sectional view of another embodiment of the cutting insert, and the view direction is referenced Figure 7 .

[0019] Fig.10 It is a three-dimensional structural schematic diagram of an embodiment of a cutting tool of the present invention.

[0020] The following are the descriptions of the reference numerals:

[0021] L, rotation center axis; B, rear end; F, front end; A1, first area; A2, second area;

[0022] 1. Cutting blades;

[0023] 11. Constraint surface; 111. First constraint surface; 112. Second constraint surface;

[0024] 12, peripheral portion; 121, back angle surface; 1211, main back angle surface; 1212, secondary back angle surface; 122, chip discharge groove; 123, front angle surface; 124, inclined surface;

[0025] 13. Through hole;

[0026] 14, cutting edge; 141, front cutting edge; 142, first cutting edge; 143, second cutting edge;

[0027] 15, cooling groove; 151, inlet section; 152, transition section; 153, injection section; 153a, first injection section; 153b, second injection section; 155, plane; 156, curved surface;

[0028] 2. Tool handle; 21. Tool handle body; 211. Coolant channel; 22. Tool jaw;

[0029] 3. Tighten the screws. DETAILED DESCRIPTION

[0030] Typical embodiments that embody the features and advantages of the present invention will be described in detail in the following description. It should be understood that the present invention can have various changes in different embodiments without departing from the scope of the present invention, and the descriptions and illustrations therein are essentially used for illustration purposes rather than for limiting the present invention.

[0031] See also Figure 1 and Figure 2 One embodiment of the present invention provides a cutting insert 1, which extends from a rear end B to a front end F along a rotation center axis L. The cutting insert 1 has a first area A1 and a second area A2 divided by the rotation center axis L.

[0032] The cutting insert 1 has two opposing restraining surfaces 11 , an outer peripheral portion 12 located between the two restraining surfaces 11 , a through hole 13 formed between the two restraining surfaces 11 , a cutting edge 14 formed on the front end side, and a cooling groove 15 provided on the restraining surfaces 11 .

[0033] The two restraint surfaces 11 are parallel to each other and are respectively the front and back surfaces of the cutting blade 1. The two restraint surfaces 11 are 180 degrees rotationally symmetrical. For ease of description, the two restraint surfaces 11 are respectively referred to as a first restraint surface 111 and a second restraint surface 112.

[0034] The cutting edge 14 comprises a front cutting edge 141 intersecting the rotation center axis L, a first cutting edge 142 located in the first area A1, and a second cutting edge 143 located in the second area A2. The front cutting edge 141, the first cutting edge 142, and the second cutting edge 143 are connected to form a space curve. The first cutting edge 142 and the second cutting edge 143 are 180 degrees rotationally symmetrical.

[0035] Figure 2 As shown, the cutting insert 1 of this embodiment is a ball-end milling cutter insert, and the cutting edge 14 is projected onto a semicircle. The profile of the cutting edge 14 rotating around the rotation center axis L forms a hemisphere, so that spherical surface processing can be performed.

[0036] In other embodiments not shown, the extended shape of the cutting edge 14 is not limited to the above-mentioned spatial arc shape, but can also be a plane or a spatial curve, etc., so that the cutting blade 1 forms other types of tools, such as a flat-angle end mill, an arc end mill, etc.

[0037] The through hole 13 is circular, and the circle is cocentric with the semicircle projected by the cutting edge 14. The axis (not shown) of the through hole 13 intersects with the central axis L of rotation.

[0038] The peripheral portion 12 intersects with the two restraining surfaces 11 respectively. The peripheral portion 12 has a ridge to form the cutting edge 14. Corresponding to the first cutting edge 142, the peripheral portion 12 has a rear angle surface 121 located between the first cutting edge 142 and the first restraining surface 111, wherein the rear angle surface 121 includes a main rear angle surface 1211 connected to the first cutting edge 142 and a secondary rear angle surface 1212 connected to the first restraining surface 111. Corresponding to the second cutting edge 143, the peripheral portion 12 has a front angle surface 123 connected to the second cutting edge 143 and an inclined surface 123 connected to the first restraining surface 111, and the front angle surface 123 and the inclined surface 123 are connected to form a chip discharge groove 122 therebetween. The rear angle surface 121 intersects with the chip discharge groove 122 at the rotation center axis L and corresponds to the front end cutting edge 141.

[0039] The cooling groove 15 extends from the rear end side to the front end side. In this embodiment, the cooling groove 15 on the first restraining surface 111 and the cooling groove 15 on the second restraining surface 112 are arranged 180 degrees rotationally symmetrically.

[0040] like Figure 1 and Figure 2 As shown, the cooling groove 15 on the first restraining surface 111 is taken as an example for specific description.

[0041] In this embodiment, the cooling groove 15 includes an inlet section 151 , a transition section 152 and two injection sections 153 .

[0042] The inlet section 151 extends forward from the rear end side. In this embodiment, the inlet section 151 extends forward from the center of the rear end of the cutting insert 1 to facilitate the introduction of the coolant.

[0043] The width of the inlet section 151 gradually narrows as it moves away from the rear end, so that the coolant flow rate can be gradually increased.

[0044] In some embodiments, the entrance section 151 is entirely located in the first area A1, thereby leaving a larger restraining area for the second area A2, compensating for the area loss caused by the chip discharge groove 122 in the second area A2, and improving the restraining effect.

[0045] In this embodiment, the inlet section 151 extends along a straight line to facilitate the flow of coolant and reduce the flow rate and pressure loss. The inlet section 151 extends obliquely toward the first area A1 relative to the rotation center axis L, and has an angle with the rotation center axis L, which facilitates a smooth transition between it and the transition section 152, and at the same time, it can also make the second area A2 have a larger restraint area. In some embodiments, the inlet section 151 can also be a curve with a larger curvature.

[0046] The transition section 152 is connected to one end of the inlet section 151 close to the through hole 13, and extends along the through hole 13 in a curved shape. Specifically, the transition section 152 is in an arc shape, and is arranged roughly concentrically with the through hole 13, with a gap between the through hole 13. The transition section 152 is also located in the first area A1 as a whole, and extends from the rear end side to the front end side around the through hole 13. In some other embodiments, the transition section 152 may also be in other curved shapes that are curved and extended.

[0047] The two injection sections 153 are respectively connected to the front end of the transition section 152 , and respectively extend from the transition section 152 to the ridgeline where the first restraining surface 111 and the outer peripheral portion 12 intersect.

[0048] The junction of the two injection sections 153 and the transition section 152 is located in the first area A1, so that the first restraint surface 111 can have a larger restraint area in the area between the two injection sections 153, which is convenient for stress dispersion and improves the restraint effect of the front end of the cutting blade 1.

[0049] In this embodiment, the two injection sections 153 are respectively a first injection section 153 a extending toward the front cutting edge 141 and a second injection section 153 b extending toward the second cutting edge 143 .

[0050] exist Figure 2 As shown in the front view of the first restraint surface 111, the first injection section 153a is smoothly connected to the transition section 152 and extends to the tip of the cutting blade 1 to cool the front cutting edge 141 and help remove chips. In the cutting blade 1, the cutting speed at the tip is zero. This embodiment improves the heat dissipation and chip removal at the front cutting edge 141 through the design of the cooling groove 15 and its first injection section 153a, which can overcome the problems of difficult heat dissipation at the tip of the cutting blade and difficult chip removal in the traditional cutting blade 1. In addition, the flow pressure loss of the coolant sprayed toward the front cutting edge 141 is greatly reduced compared with the prior art, which improves the effect of coolant spraying, thereby facilitating the heat dissipation and chip removal of the front cutting edge 141, and improving the workpiece processing surface quality and cutting blade life.

[0051] In this embodiment, the first injection section 153a extends in a straight line, the coolant flow loss is small, and the processing is convenient. In other embodiments, the first injection section 153a can also extend in a smooth curve, such as a circular arc, an elliptical arc, a complex curve, etc.

[0052] The smooth connection between the first injection section 153a and the transition section 152 can be understood as follows: Figure 2 and Figure 3From the front view, there is no step difference or obvious bend at the junction of the first injection section 153a and the transition section 152. Although there may be manufacturing tolerances, the junction of the first injection section 153a and the transition section 152 can generally meet the following conditions:

[0053] like Figure 3 As shown, on the boundary line where the first injection section 153a and the transition section 152 meet, take any two points P1 and P2, and make a tangent line through the two points P1 and P2. MAX When , the angle α between the tangents at two points P1 and P2 is ≤16°. MAX Refers to the maximum depth of the cooling groove 15, about H MAX For instructions, see Figure 7 and Figure 8 .

[0054] In addition, if the center line of the first injection section 153a and the transition section 152 is used as a measure, any two points spaced apart from each other at the portion where the center lines of the two meet the above conditions. The center line is defined as: the direction perpendicular to the coolant flow direction is the width direction of the cooling groove 15, and the imaginary line passing through the center line in the width direction is the center line of the cooling groove 15.

[0055] See also Figure 2 and Figure 3 , the second injection section 153b extends to the chip discharge groove 122 corresponding to the second cutting edge 143, cooling the second cutting edge 143 and helping chip removal. In the front view, the cutting edge radiation angle corresponding to the intersection of the extension line of the second injection section 153b and the second cutting edge 143 is roughly in the range of 30° to 50°. The cutting edge of this radiation angle is used more frequently, which can achieve a better cooling effect and facilitate the diffusion of the coolant. Among them, the cutting edge radiation angle refers to the angle between the line connecting a certain point on the cutting edge to the center of the through hole 13 and the rotation center axis L.

[0056] In this embodiment, the second injection section 153b also extends in a straight line, with small flow loss and convenient processing. Similarly, the second injection section 153b can also extend in a smooth curve, such as a circular arc, an elliptical arc, a complex curve, etc.

[0057] Preferably, the second injection section 153b is also smoothly connected to the transition section 152. The definition of "smooth connection" can be referred to above. Figure 3 , on the boundary line where the second injection section 153b and the transition section 152 meet, an interval of H is arbitrarily taken MAX The angle β between the tangents of the boundary line at the two points P3 and P4 is ≤16°.

[0058] Still reading Figure 3 Preferably, the transition section 152 and the entrance section 151 are also smoothly connected. Similarly, on the boundary line where the transition section 152 and the entrance section 151 meet near the through hole 13, an interval of H is arbitrarily taken. MAX The angle θ between the tangent lines of the boundary line passing through the two points P5 and P6 is ≤ 16°. On the boundary line away from the through hole 13 at the junction of the transition section 152 and the entrance section 151, an interval of H is arbitrarily taken. MAX The angle γ between the tangents of the boundary line at the two points P7 and P8 is ≤16°.

[0059] Therefore, during the entire flow process of the coolant, it enters from the inlet section 151, then passes through the transition section 152, and is finally sprayed toward the front cutting edge 141 by the first spray section 153a, and sprayed toward the second cutting edge 143 by the second spray section 153b. The flow velocity and pressure loss during the entire flow process can be greatly reduced compared to the prior art, thereby improving the final spraying effect.

[0060] Furthermore, combined with Figure 4 and Figure 5 , the depth h2 of the first injection section 153a is shallower than the depth h1 of the transition section 152, that is, h2

[0061] Recombination Figure 4 and Figure 6 , the depth h3 of the second injection section 153b is shallower than the depth h1 of the transition section 152, that is, h3

[0062] In some embodiments, the first injection section 153a and the second injection section 153b have the same depth and width, so that the injection effects of the two injection sections 153 are roughly equivalent, and when the flow is diverted from the transition section 152 to the two injection sections 153, the flow distribution is more uniform.

[0063] from Figures 4 to 6 ​​It can be seen that the cross section of the cooling groove 15 can be designed in various forms as long as it is convenient for the coolant to pass through, such as semicircular, U-shaped, inverted trapezoidal, etc. In addition, in the extension direction of the cooling groove 15, the cross section of the cooling groove 15 can be adaptively changed according to the changes in the width and depth at different positions.

[0064] See also Figure 2 , Figure 7 and Figure 8 In some embodiments, the depth of the cooling groove 15 gradually decreases along its extension direction from the rear end to the front end, and the rear end entrance of the inlet section 151 has a maximum depth H MAX , the outlet of the injection section 153 has the minimum depth. Thus, the coolant gradually increases its flow rate and pressure. At the same time, the depth gradually becomes shallower, that is, the bottom surface of the cooling groove 15 transitions smoothly, which also reduces the flow rate and pressure loss of the coolant.

[0065] exist Figure 7 In the structure shown, the bottom surface of the cooling groove 15 is entirely located on a plane 155, and the plane 155 is inclined relative to the first restraining surface 111, and has an angle δ with the first restraining surface 111. In some embodiments, the angle δ is preferably 0.5° to 5°.

[0066] exist Figure 8 In the structure shown, the bottom surface of the cooling groove 15 is a smoothly transitioned curved surface 156. In this structure, the depth of the cooling groove 15 can also be gradually reduced. The smoothly transition curved surface 156 of the cooling groove 15 generally satisfies the following conditions: on the curved surface 156, along the center line of the cooling groove 15, the interval is H MAX Take any two points of the first constraint surface 111 and make a vertical plane perpendicular to the first constraint surface 111 through the two points. Make tangents to the center line through the two points on the vertical plane. The angle between the two tangents is ≤16°, and the optimal angle is 0°~5°.

[0067] See also Fig. 9 In some embodiments, only the injection section 153 of the cooling groove 15 can be set to a structure in which the depth gradually becomes shallower in the direction away from the rear end, while the depths of the inlet section 151 and the transition section 152 remain unchanged. At this time, the bottom surface of the cooling groove 15 at the injection section 153 is a plane inclined relative to the first constraint surface 111 or a gentle curved surface, while the bottom surface of the cooling groove 15 is a plane at the inlet section 151 and the transition section 152. In this structure, the coolant can still gradually increase the flow rate and pressure after entering the injection section 153. In the inlet section 151 and the transition section 152, if the coolant needs to be accelerated and pressurized, it can be achieved by gradually reducing the width of the inlet section 151 and the transition section 152.

[0068] See also Fig.10According to one embodiment of the present invention, there is also provided a cutting tool, which comprises a tool holder 2 and the cutting insert 1 described above.

[0069] The handle 2 extends forward and backward along the rotation center axis L, and includes a handle body 21 and two spaced jaws 22 provided at the front end of the handle body 21. A coolant channel 211 extending forward and backward is provided inside the handle body 21, and the coolant channel 211 is connected to the space between the two jaws 22. The jaws 22 are provided with fastening holes (not numbered in the figure).

[0070] The cutting blade 1 is installed between the two jaws 22 of the tool holder 2 and is connected and fixed by a fastening screw 3 penetrating the jaws 22 and the through hole 13, and the two restraining surfaces 11 of the cutting blade 1 face the two jaws 22 respectively. The cooling groove 15 of the cutting blade 1 is connected to the coolant channel 211 in the tool holder 2.

[0071] When the cutting tool is in use, the handle 2 drives the cutting blade 1 to rotate around the central axis of rotation L, and the cutting edge 14 of the cutting blade 1 contacts the workpiece to process the workpiece. The coolant is added from the rear end of the handle 2, enters the cooling groove 15 of the cutting blade 1 through the coolant channel 211, and is sequentially sprayed toward the cutting edge 14 through the inlet section 151, the transition section 152 and the spray section 153 to dissipate heat from the cutting edge 14 and assist in chip discharge. The coolant can be liquid or gas.

[0072] Although the present invention has been described with reference to several typical embodiments, it should be understood that the terms used are illustrative and exemplary, rather than restrictive. Since the present invention can be embodied in a variety of forms without departing from the spirit or essence of the invention, it should be understood that the above embodiments are not limited to any of the foregoing details, but should be interpreted broadly within the spirit and scope defined by the appended claims, so all changes and modifications falling within the scope of the claims or their equivalents should be covered by the appended claims.

Claims

1. A cutting blade extending from a rear end to a front end along a rotation center axis; the cutting blade having a first area and a second area divided by the rotation center axis; characterized in that: The cutting insert has: Two restraining surfaces having a first restraining surface and a second restraining surface opposite to each other; The outer periphery is located between the two restraining surfaces; A through hole formed between the two restraining surfaces; a cutting edge formed on the front end side; The cutting edge has: a front cutting edge intersecting the central axis of rotation; a first cutting edge located in the first region of the peripheral portion; The peripheral portion further comprises a relief surface located between the first cutting edge and the first restraining surface; The first restraint surface has a cooling groove extending from the rear end side to the front end side; The cooling tank comprises: an inlet section extending from the rear end side; A transition section connected to one end of the inlet section close to the through hole and extending along the through hole in a curved manner; A plurality of injection sections, respectively connected to the transition section and respectively extending from the transition section to the ridgeline where the first restraining surface intersects the outer peripheral portion; From the front view of the first restraining surface, the plurality of injection sections are smoothly connected to the transition section, and have a first injection section extending toward the front cutting edge. Take any two points on the boundary line where the first injection section and the transition section meet, and make tangents to the boundary line through the two points. When the distance between the two points is less than HMAX, the angle α between the tangents at the two points is ≤16°, where HMAX refers to the maximum depth of the cooling groove. The junctions between the plurality of injection sections and the transition section are all located in the first region.

2. The cutting insert according to claim 1, characterized in that The inlet section extends forwardly from a center of the rear end.

3. The cutting insert according to claim 1, characterized in that The inlet section is entirely located in the first region.

4. The cutting insert according to claim 1, characterized in that The depth of the first injection section is shallower than the depth of the transition section.

5. The cutting insert according to claim 1, characterized in that The cutting edge also has a second cutting edge located in the second region of the outer periphery; The outer peripheral portion further comprises a chip discharge groove located between the first restraining surface and the second cutting edge; The plurality of injection segments further include a second injection segment smoothly connected to the transition segment and extending toward the chip discharge groove.

6. The cutting insert according to claim 5, characterized in that The depth of the second injection section is shallower than the depth of the transition section.

7. The cutting insert according to claim 6, characterized in that The depth of the second injection section is equal to the depth of the first injection section.

8. The cutting insert according to claim 1, characterized in that The transition section and the inlet section are smoothly connected.

9. The cutting insert according to claim 1, characterized in that The inlet section extends in a straight line.

10. The cutting insert according to claim 9, characterized in that The inlet section extends obliquely toward the first region relative to the rotation center axis.

11. The cutting insert according to claim 1, characterized in that The width of the inlet section gradually narrows away from the rear end.

12. The cutting insert according to claim 1, characterized in that The plurality of injection sections extend in straight lines respectively.

13. The cutting insert according to claim 1, wherein At least one of the injection sections extends in a smooth curve.

14. The cutting insert according to claim 1, characterized in that The depth of the cooling groove gradually becomes shallower as it moves away from the rear end.

15. The cutting insert according to claim 14, characterized in that The bottom surface of the cooling groove is located on a plane, and the plane is inclined relative to the first restraining surface and has an angle with the first restraining surface.

16. The cutting insert according to claim 14, characterized in that The bottom surface of the cooling groove is a curved surface with a smooth transition.

17. A cutting tool, comprising a shank and a cutting blade as claimed in any one of claims 1 to 16, wherein a coolant channel is provided in the shank; the cutting blade is mounted on the front end of the shank, and a cooling groove of the cutting blade is connected to the coolant channel.

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