Cutter for machining red copper slender shaft

Abstract

The cutter comprises a cutter body and four cutting edges, the cutter body is cylindrical, a through hole is formed in the center of the cutter body, the cutting edges are in pyramid-like shapes and are arranged at one end of the cutter body, and the four cutting edges are evenly arranged along the center of the through hole and are integrally formed with the cutter body; the cutting edge comprises a front angle gamma, a first rear angle alpha 1 and a second rear angle alpha 2, wherein gamma is larger than or equal to 3 degrees and smaller than or equal to 5 degrees, alpha is larger than or equal to 6 degrees and smaller than or equal to 8 degrees, and alpha 2 is larger than or equal to 40 degrees and smaller than or equal to 45 degrees. The small-diameter slender shaft can be clamped by the drill chuck, the small-diameter slender shaft can be machined by combining a common lathe, equipment special for machining the slender shaft does not need to be specially designed, and the machining cost is effectively reduced. Aiming at the problems of low strength and hardness and high plasticity and toughness of a red copper material, the designed cutting edge can effectively avoid the conditions of deformation and breakage of the slender shaft, and meanwhile, the situation that cuttings are wound on the machined surface of the red copper shaft to affect the surface quality of parts is avoided.

Description

Technical Field

[0001] The invention relates to the technical field of mechanical processing, in particular to a tool for processing a slender copper shaft. Background Art

[0002] With the diversification of the structural types of aircraft engine parts, the requirements for parts processing accuracy are constantly increasing, and the processing methods also need to be continuously innovated and improved. In order to meet the processing accuracy requirements of the products, during the processing process, it is necessary to process some aircraft engine housing parts, the bottom surface of some holes or small holes at the inclined surface. Due to the special location of the holes to be processed, a slender drill is required for processing. Due to the slenderness and poor rigidity of the drill, it is difficult to meet the processing accuracy requirements by mechanical processing methods, so electric sparks are used for processing, and the electric spark machine tools used for processing product parts use copper electrodes. Although this type of slender electrode is simple in shape, it is slender, and its small outer circle has an aspect ratio of about (L / D) 26:1. In addition, the strength and hardness of copper are low, and the plasticity and toughness are high. The chips are not easy to break and are easily entangled on the processed surface of the parts, affecting the surface quality of the parts; in addition, the linear expansion coefficient of copper is large, and the parts are deformed by the cutting heat during turning. The center clamping method during conventional shaft processing will generate axial clamping force, causing the slender shaft workpiece to bend and deform. In addition, since traditional lathes use workpiece rotation as the main motion, the centrifugal force generated will cause the tiny slender shaft to bend, affecting the processing accuracy.

[0003] When turning the small outer circle of the part, the commonly used clamping methods are: one-time clamping and turning, one-clip and one-clip, or one-clip and one-drag. For one-time clamping and turning, due to the long extension length of the part, the strength and rigidity of the copper material are poor, and the turning allowance is large. The radial cutting force generated by the slender copper part under the turning action of the tool is affected by the centrifugal force during the high-speed rotation process, which aggravates the bending deformation and vibration of the workpiece. For one-clip and one-drag clamping, as the outer diameter allowance of the part gradually decreases, the strength and rigidity of the part deteriorate, and the drag chuck cannot be driven to rotate, causing the part to bend, deform, twist, or break. For one-clip and one-clip, when the above method is used for clamping and turning, even if a very sharp high-speed steel tool is used for processing, as the outer diameter allowance of the part gradually decreases, the strength and rigidity of the part deteriorate. When it is close to the drawing size, the center hole is difficult to support with one-clip clamping, and the part slips off the top, bends, or breaks. Summary of the invention

[0004] In order to solve the above problems, the present invention provides a tool for processing a slender copper shaft, aiming to solve the problem that the strength and hardness of the copper material are low, and it is easy to bend, deform, twist and break when processed into a slender shaft, so as to achieve high-precision and high-efficiency processing, and at the same time it is easy to use and has low processing cost.

[0005] In order to achieve the above-mentioned purpose, the present invention adopts the following technical scheme: a tool for processing a slender copper shaft, the tool comprising a blade and a cutting edge, the blade body is cylindrical and has a through hole in the center, the cutting edge is pyramid-shaped and is arranged at one end of the blade body, there are four cutting edges and they are evenly arranged along the center of the through hole and are integrally formed with the blade body, the cutting edge comprises a front angle γ, a first back angle α1 and a second back angle α2, wherein 3°≤γ≤5°, 6°≤α1≤8°, and 40°≤α2≤45°.

[0006] The angle between two relative cutting edges is the cutting cone angle β, 90°≤β≤180°.

[0007] The cutting edge has an inclination angle of λs, λs=0°.

[0008] The rear end of the through hole is provided with an inner circular step, and the flexible circular ring is arranged on the inner circular step and is interference fit with the inner circular step.

[0009] The length of the inner circle step is X, the length of the through hole is Y, and X=2 / 3Y.

[0010] The coaxiality between the outer circle of the blade body and the through hole is Φ, Φ=0.02mm.

[0011] An inverted cone is provided at the front end of the through hole, and the taper of the inverted cone is 10:0.02.

[0012] Beneficial effects of the present invention: 1. Compared with the prior art, the tool of the present invention can be clamped by a drill chuck, and combined with an ordinary lathe, it can realize the processing of small-diameter slender shafts. There is no need to specially design equipment for processing slender shafts, which effectively reduces the processing cost. At the same time, it avoids the use of a drag chuck or a center to pre-tighten the workpiece on an ordinary lathe. The workpiece is positioned and pre-tightened by four pyramid-shaped cutting edges, which reduces the axial force on the workpiece and effectively avoids bending, deformation or breakage of the workpiece during clamping.

[0013] 2. For copper materials, due to their low strength and hardness, they are easily broken or deformed under unidirectional load. The cutting edge of the present invention is suitable for processing slender copper shafts, and four cutting edges are used for cutting, which eliminates the unidirectional force of the turning tool on the parts in the traditional processing process, effectively avoiding the deformation and breakage of the parts due to the unidirectional force. According to tests, the cutting work can be completed with one feed, thereby improving the yield rate and processing efficiency.

[0014] 3. Copper material has great plasticity and toughness, and chips are not easy to break and are easily entangled on the processed surface of parts, affecting the surface quality of parts. The present invention positions the inner hole of the tool, and the processed surface of the part extends in the through hole of the tool, supported and restricted by the hole wall, avoiding chip entanglement and scratching. The turned parts have good cylindricity and high surface quality. BRIEF DESCRIPTION OF THE DRAWINGS

[0015] The present invention will be further described below in conjunction with the accompanying drawings: Figure 1 It is a schematic diagram of the present invention; Figure 2 is a cross-sectional view of the present invention; Figure 3 It is a left side view of the present invention; Figure 4 for Figure 3 The local enlarged view in the middle C direction; In the figure: 1, blade body; 11, through hole; 111, inner circle step; 112, inverted cone; 2, cutting edge; 3, flexible ring. DETAILED DESCRIPTION

[0016] In order to make the purpose, technical solutions and advantages of the embodiments of the present invention clearer, the technical solutions in the embodiments of the present invention will be clearly and completely described below in conjunction with the drawings in the embodiments of the present invention. Obviously, the described embodiments are only part of the embodiments of the present invention, rather than all the embodiments.

[0017] The technical solution of the present invention is described in detail with specific embodiments below. The following specific embodiments can be combined or replaced with each other according to actual conditions, and the same or similar concepts or processes may not be described in detail in some embodiments. Example

[0018] The present invention provides a tool for processing a slender red copper shaft, the tool comprising a blade body 1 and a cutting edge 2, the blade body 1 is cylindrical and has a through hole 11 in the center, the cutting edge 2 is pyramid-shaped and is arranged at one end of the blade body 1, the cutting edge 2 is four and is evenly arranged along the center of the through hole 11 and is integrally formed with the blade body 1, the cutting edge 2 comprises a front angle γ, a first back angle α1 and a second back angle α2, wherein 3°≤γ≤5°, 6°≤α1≤8°, and 40°≤α2≤45°.

[0019] The present invention can be clamped by a drill chuck and combined with an ordinary lathe to realize processing of a small diameter slender shaft, without the need to specially design equipment for processing the slender shaft, thereby effectively reducing processing costs. During actual processing, the copper shaft is placed in the machine tool chuck and clamped, the outer diameter of the tool is designed to be consistent with the outer diameter of the copper shaft, and the diameter of the through hole 11 is consistent with the diameter of the target slender shaft.

[0020] By evenly arranging four cutting edges 2 along the center of the through hole 11 for cutting, the unidirectional force of the turning tool on the part in the traditional processing process is eliminated, and the deformation and breakage of the part caused by the unidirectional force is effectively avoided. In addition, the cutting edge 2 is in a pyramid shape, which can achieve a gradual transition between the processed surface and the unprocessed surface during cutting, effectively reducing stress concentration and extending the service life of the slender copper shaft.

[0021] Due to the large linear expansion coefficient of copper, parts are deformed by cutting heat during turning. The rake angle range of the cutting edge 2 is set to 3°≤γ≤5°. Since it is a one-time processing method, the turning allowance is large, and a small rake angle can enhance the strength of the blade. During processing, the chips are easily formed into strips, which is beneficial to chip removal and helps reduce cutting force and cutting heat.

[0022] The cutting edge 2 has a first clearance angle α1 and a second clearance angle α2, 6°≤α1≤8°, 40°≤α2≤45°. Multiple clearance angles are used to leave enough chip space to ensure that the cutting edge is sharp and has sufficient strength.

[0023] Through the through hole 11 in the center of the blade body 1, the machined surface of the copper shaft extends in the through hole 11, supported and restricted by the hole wall to avoid chip entanglement and scratching, so that the cut copper electrode has good cylindricity and high surface quality, and the inner circle step 111 opened at the rear end of the through hole 11 has an interference fit with the flexible ring 3, further ensuring the coaxiality of the workpiece and the consistency of the inner circle size and avoiding scratching the surface of the part.

[0024] Specifically, the angle between the two cutting edges 2 is the cutting cone angle a, 90°≤a≤180°. When the cutting cone angle is large, the main cutting edge is short, the tool is easier to sharpen, the centering is poor, the part is easy to swing, the cutting is unstable during the part processing, and it is easy to jump out of the hole. When the cone angle is small, it is the opposite. Considering the processing technology of the tool and the processing technology of the part, when a is 90°, it is more ideal, which is convenient for tool sharpening, and the cutting process is stable and stable, which is conducive to ensuring the quality and accuracy of the part.

[0025] Specifically, according to the need for chip removal during machining, the cutting edge 2 has an inclination angle of λs, λs=0°, and the chips are basically removed in a direction perpendicular to the main cutting edge during cutting, which is conducive to the smooth progress of the cutting process.

[0026] Specifically, in order to avoid scratching the copper workpiece, the rear end of the through hole 11 is provided with an inner circular step 111, and the flexible circular ring 3 is arranged on the inner circular step 111 and is interference fit with the inner circular step 111, so the length of the inner circular step 111 is X, the length of the through hole 11 is Y, and X=2 / 3Y. The flexible circular ring 3 can be made of a soft fluoroplastic material, which can effectively prevent the slender shaft that has been processed from being affected by centrifugal force during high-speed rotation, causing bending deformation and vibration.

[0027] Specifically, in order to meet the outer circle runout requirement of the processed part, the coaxiality between the outer circle of the blade body 1 and the through hole 11 is Φ, Φ=0.02mm.

[0028] Specifically, in order to reduce the friction with the outer circle of the part during the cutting process, the front end of the through hole 11 is provided with an inverted cone 112, and the taper of the inverted cone 112 is 10:0.02. The machined surface extends in the tool through hole 11, and is supported and restricted by the hole wall to avoid chip entanglement and scratching. The electrode turned out has good cylindricality, and the outer circle is polished through the hole wall of the through hole 11, with precise size, good consistency, and small surface roughness.

[0029] In addition to the above-mentioned preferred embodiments, the present invention also has other implementation modes. Based on the embodiments of the present invention, all other embodiments obtained by ordinary technicians in this field without making any creative work are within the scope of protection requested by the present invention.

Claims

1. A tool for processing a slender copper shaft, characterized in that: The tool comprises a blade body (1) and a cutting edge (2); the blade body (1) is cylindrical and has a through hole (11) at the center; the cutting edge (2) is pyramid-shaped and is arranged at one end of the blade body (1); there are four cutting edges (2) which are evenly arranged along the center of the through hole (11) and are integrally formed with the blade body (1); the cutting edge (2) comprises a front angle γ, a first back angle α1, and a second back angle α2, wherein 3°≤γ≤5°, 6°≤α1≤8°, and 40°≤α2≤45°.

2. A tool for machining a slender copper shaft according to claim 1, characterized in that: The included angle between the two relative cutting edges (2) is a cutting cone angle β, 90°≤β≤180°.

3. A tool for machining a slender copper shaft according to claim 1, characterized in that: The cutting edge (2) has an inclination angle of λs, λs=0°.

4. A tool for machining a slender copper shaft according to claim 1, characterized in that: An inner circular step (111) is provided at the rear end of the through hole (11), and the flexible circular ring (3) is arranged on the inner circular step (111) and is interference fit with the inner circular step (111).

5. A tool for machining a slender copper shaft according to claim 4, characterized in that: The length of the inner circular step (111) is X, the length of the through hole (11) is Y, and X=2 / 3Y.

6. A tool for machining a slender copper shaft according to claim 1, characterized in that: The coaxiality between the outer circle of the blade body (1) and the through hole (11) is Φ, Φ=0.02 mm.

7. A tool for machining a slender copper shaft according to claim 1, characterized in that: An inverted cone (112) is provided at the front end of the through hole (11), and the taper of the inverted cone (112) is 10:0.02.

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