A method for machining a firearm swivel head

Abstract

This invention discloses a method for machining a rotary gun head body, featuring highly integrated processes, unified benchmarks, high flexibility, and scalability. The method includes the following steps: S1, workpiece benchmark cutting: rough machining the workpiece head shape, finish machining the workpiece head end face, central benchmark hole, and positioning groove; rotating the workpiece 180°, rough machining the workpiece tail end face, and finish machining the workpiece tail central deep hole and center hole; S2, workpiece rod cutting: using the workpiece head central benchmark hole and tail center hole as clamping centers, using the workpiece head positioning groove as a benchmark for circumferential positioning, and using the workpiece head front face as a benchmark for axial positioning, rough machining the workpiece rod shape; S3, workpiece forming cutting: using the workpiece head central benchmark hole and tail center hole as clamping centers, using the workpiece head positioning groove as a benchmark for circumferential positioning, and using the workpiece head central benchmark hole bottom plane as a benchmark for axial positioning, finish machining the gun head body locking teeth, assembly groove, and helical surface.

Description

TECHNICAL FIELD

[0001] The present application relates to the technical field of machining, in particular to a gun rotary head body machining method. BACKGROUND

[0002] The head body is an important core part of a gun, which performs high-speed reciprocating motion in the gun and also rotates synchronously within a certain range. The machining quality of the head body plays a very important role in the reliability, interchangeability and service life of the gun and directly affects the overall performance of the gun. The rotary head body is the most common typical structure in guns. The traditional rotary head body machining process has many procedures, a complex process, and multiple reference conversions, which leads to low machining efficiency, large equipment resource occupation, poor size consistency, low pass rate and other problems. The machining process is not suitable for the development trend of automation and digitization, and it is not replicable and promotable. Therefore, how to design a typical machining process with high process integration, high flexibility, unified reference and replicability has become a technical problem in this technical field. SUMMARY

[0003] The present application aims to overcome the shortcomings of the prior art and provide a gun rotary head body machining method, which is highly integrated and has a unified reference, high flexibility and replicability, and can realize efficient and accurate machining of the gun rotary head body, solving the problems of low size consistency, pass rate and appearance quality of the head body machined by the traditional process, and poor reliability, interchangeability and service life of the assembled gun.

[0004] The purpose of the present application is achieved as follows:

[0005] A gun rotary head body machining method, comprising the following steps:

[0006] S1, workpiece reference cutting

[0007] The workpiece forging blank is clamped on the hydraulic rotary table clamp of the vertical machining center, the workpiece head shape is rough machined, and the workpiece head end face, center reference hole and positioning groove are precisely machined;

[0008] The hydraulic rotary table clamp drives the workpiece to rotate by 180°, the workpiece tail end face is rough machined, and the workpiece tail center deep hole and center hole are precisely machined;

[0009] S2, workpiece rod cutting

[0010] The workpiece is clamped on the lathe clamp of the numerical control lathe with the workpiece head center reference hole and tail center hole as the clamping center, the workpiece head positioning groove as the reference circumferential positioning, and the workpiece head front end face as the reference axial positioning. The numerical control lathe drives the workpiece to rotate, and the workpiece rod shape is rough machined;

[0011] S3, Workpiece forming and cutting

[0012] Using the center reference hole at the head of the workpiece and the center hole at the tail as the clamping center, the workpiece head positioning groove as the reference for circumferential positioning, and the bottom plane of the center reference hole at the head of the workpiece as the reference for axial positioning, the workpiece is clamped on the hydraulic rotary table fixture of the vertical machining center, and the locking teeth, assembly groove, and spiral surface of the machine head body are precision machined.

[0013] Preferably, in step S1, different types of milling cutters are used to process the workpiece head shape, workpiece head end face, center reference hole, and positioning groove; milling cutter is used to process the workpiece tail end face, and drill bit is used to process the workpiece tail center deep hole and center hole; during the processing, the machining center nozzle sprays coolant evenly onto the workpiece surface to cool the workpiece.

[0014] Preferably, in step S2, a carbide lathe tool is used to machine the shape of the workpiece rod; during the machining process, the CNC lathe nozzle sprays coolant onto the tool tip to cool the tool and the machined part of the workpiece and to flush away the chips.

[0015] Preferably, in step S3, a milling cutter is used to process the locking teeth, assembly groove, and helical surface of the machine head body; during the processing, the machining center nozzle sprays coolant evenly onto the milling cutter position to cool the tool and the machined part of the workpiece and wash away the chips.

[0016] Preferably, the coolant is prepared by diluting emulsion stock solution with water, and the emulsion concentration is 7% to 8%.

[0017] Preferably, the method further includes the step of:

[0018] S4, Workpiece heat treatment

[0019] The workpiece is quenched and tempered using a vacuum heat treatment process. The quenching temperature is 820℃~900℃ and the holding time is 1.5h~2h, with nitrogen cooling. The tempering temperature and time are 200℃~240℃ and the holding time is 3h~3.5h. After tempering, the workpiece is taken out and allowed to cool to room temperature in the air.

[0020] S5, Secondary cutting of the workpiece

[0021] The rod part of the workpiece is precision machined using a conventional cylindrical grinding machine.

[0022] Preferably, the method further includes the step of:

[0023] S6. Surface finishing of the workpiece

[0024] Centrifugal rolling finishing is used to perform surface finishing on the workpiece;

[0025] S7. Workpiece Surface Treatment

[0026] The workpiece is ultrasonically degreased and cleaned, and then placed in a vacuum coating equipment for diamond-like carbon coating surface treatment. The coating temperature is 80℃~120℃, the vacuum degree is ≤(8.0E-3)Pa, and the coating time is 12h~16.5h.

[0027] Preferably, in step S6, when the workpiece surface is finished, a centrifugal high-speed rotation method is used for finishing. The abrasive material is high-frequency ceramic or zirconia fine polishing abrasive. The volume ratio of abrasive to workpiece is 75% to 85%, the mass mixing ratio of abrasive to workpiece is 1:1 to 2:1, and the processing time is 50 min to 60 min.

[0028] Preferably, in step S7, after the workpiece is coated with diamond-like carbon, the film thickness is 2.5 to 3.5 μm and the surface hardness is 2500 to 3500 HV15 mN.

[0029] Due to the adoption of the above technical solution, the present invention has the following beneficial effects:

[0030] (1) The machining process of the rotating head body of the gun is to reconstruct the traditional process and integrate the process to ensure the uniformity of the machining benchmark. The finished size is more consistent and the machining qualification rate is higher. It is also highly flexible and has the ability to process multiple products in batches. It is more suitable for automated and digital manufacturing production mode, occupies less equipment resources, consumes less energy, and reduces the scale of labor and manufacturing costs.

[0031] (2) The machining process for the rotary gun head body employs centrifugal rolling grinding to finish the workpiece surface. This effectively removes cutting marks, small flashes, and burrs, reducing the surface roughness by 1-2 grades. It also allows for smooth transitions between workpiece edges, improves the physical and mechanical properties of the workpiece surface, increases surface hardness, and alters the residual stress state. This is a high-quality precision machining method before coating. Furthermore, this machining method offers advantages such as reduced costs and less labor intensity for workers.

[0032] (3) The machining process of the rotary gun head body can improve the heat treatment effect by placing the workpiece into a vacuum furnace and a tempering furnace in sequence for heat treatment. The workpiece has good surface quality, small deformation, stronger hardness, fatigue strength and oxidation resistance, and no waste gas emission, making it more environmentally friendly.

[0033] (4) The machining process of the rotary gun head body involves placing the workpiece into a coating equipment for diamond-like carbon coating surface treatment. The diamond-like carbon film has both the hardness of diamond and the lubricity of graphite, and has extremely high hardness and good wear resistance. This makes the workpiece after surface treatment more wear-resistant, has better surface hardness, lubricity, and corrosion resistance. The resulting gun head body will have better appearance quality and a longer service life. Moreover, the surface treatment process does not generate "three wastes" pollution, and the process is clean, safe, and environmentally friendly. Attached Figure Description

[0034] Figure 1 This is a process flow diagram of the present invention.

[0035] Figure 2 This is a schematic diagram of the structure of workpiece S1 after reference cutting;

[0036] Figure 3 This is a schematic diagram of the structure of the rod section of workpiece S2 after cutting;

[0037] Figure 4 This is a schematic diagram of the structure of workpiece S3 after forming and cutting;

[0038] Figure 5 This is a schematic diagram showing the position of the locking teeth;

[0039] Figure 6 This is a schematic diagram showing the position of the locking surface (spiral surface);

[0040] Figure 7 This is a schematic diagram showing the location of the assembly slot. Detailed Implementation

[0041] The following are specific embodiments of the present invention, and the technical solutions of the present invention will be further described in conjunction with the embodiments, but the present invention is not limited to these embodiments.

[0042] Example 1

[0043] A machining process for a rotating bolt head of a firearm includes the following steps:

[0044] S1. Workpiece reference cutting: Fix the forged blank on the hydraulic rotary table fixture of the vertical machining center. Then, according to the dimensions of the workpiece drawing, use different types of milling cutters to perform rough cutting on the head shape of the workpiece, and finish cutting on the front end face of the head, the head center reference hole and the positioning groove. After that, the hydraulic rotary table fixture drives the workpiece to rotate 180°. Use milling cutters and drills to perform finish cutting on the rear end face of the tail, the center deep hole and the center hole of the workpiece. The reference for the subsequent machining positioning of the workpiece is machined. During the rough cutting and finish cutting of the workpiece, the spray nozzle on the machining center sprays coolant evenly on the surface of the workpiece to cool it. The coolant flows with the equipment to the storage tank, and then is pumped out and sprayed again.

[0045] S2. Cutting of the workpiece rod: In step S1, after the workpiece reference cutting is completed, the workpiece head center reference hole and tail center hole are used as the clamping center, the workpiece head positioning groove is used for circumferential positioning, and the workpiece head front face is used for axial positioning. The workpiece is clamped on the CNC lathe turning fixture, the workpiece is rotated, and the workpiece rod shape is rough cut with a carbide turning tool. During the machining process, the CNC lathe nozzle sprays coolant to the turning tool tip to cool the tool and the machined part of the workpiece and flush away the chips.

[0046] S3. Workpiece Forming and Cutting: After the workpiece shank is cut in step S2, the workpiece is clamped on a vertical machining center hydraulic rotary table fixture, using the head center reference hole and tail center point hole as the clamping center, the head positioning groove as the circumferential positioning, and the bottom plane of the head center reference hole as the axial positioning. The hydraulic rotary table fixture can drive the workpiece to rotate 360° around the axis (clamping center). According to the dimensions of the workpiece drawing, the locking teeth, assembly groove, helical surface, and other external dimensions of the machine head body are precision machined with a milling cutter to achieve the external cutting of the workpiece. During the machining process, coolant is evenly sprayed onto the position of the milling cutter using a nozzle on the machining center to cool and rinse the tool and the workpiece being machined.

[0047] S4. Heat treatment of the workpiece: The workpiece is quenched and tempered using a vacuum heat treatment process. The quenching temperature is 820℃ and the holding time is 2h, with nitrogen cooling. The tempering temperature and time are 200℃ and the holding time is 3.5h. After tempering, the workpiece is taken out and allowed to cool to room temperature in the air.

[0048] S5. Secondary cutting of the workpiece: After heat treatment, the workpiece rod is ground and finished using a conventional cylindrical grinding machine to meet the requirements of the drawing.

[0049] S6. Surface finishing of workpiece: After the workpiece is cut twice, centrifugal rolling is used to finish the surface of the workpiece until the surface is smooth.

[0050] S7. Surface treatment of workpiece: Before coating, the workpiece is first degreased and cleaned by ultrasonication, and then the workpiece is placed in a vacuum coating equipment for diamond-like carbon coating surface treatment. The coating temperature is 80℃, the vacuum degree is (8.0E-3)Pa, and the coating time is 12h.

[0051] Furthermore, in step S1, during rough cutting, the workpiece head shape retains a 1mm allowance, and during finish cutting, the length error range of the workpiece is ±0.03mm, and the hole diameter error range of the workpiece is ±0.015mm.

[0052] Furthermore, in step S1, the coolant is made by diluting the emulsion stock solution with water, and the concentration is 7%.

[0053] Furthermore, in step S2, during rough cutting, a 0.1mm allowance is left on the outer shape of the workpiece rod.

[0054] Furthermore, in step S5, during precision cutting, the diameter error range of the workpiece rod is ±0.008mm.

[0055] Furthermore, in step S6, when the workpiece surface is finished, a centrifugal high-speed rotation method is used for finishing. The abrasive material is high-frequency ceramic, the loading amount (volume ratio) of the abrasive to the workpiece is 75%, the mass mixing ratio of the abrasive to the workpiece is 1:1, and the processing time is 50 minutes.

[0056] Furthermore, in step S7, after the workpiece is coated with diamond-like carbon, the film thickness is 2.5 to 3.5 μm and the surface hardness is 2500 to 3500 HV 15 mN.

[0057] Furthermore, in steps S1, S2, S3, and S5, the waste chips generated during workpiece cutting are collected and recycled.

[0058] Example 2

[0059] A machining process for a rotating bolt head of a firearm includes the following steps:

[0060] S1. Workpiece reference cutting: Fix the forged blank on the hydraulic rotary table fixture of the vertical machining center. Then, according to the dimensions of the workpiece drawing, use different types of milling cutters to perform rough cutting on the head shape of the workpiece, and finish cutting on the front end face of the head, the head center reference hole and the positioning groove. After that, the hydraulic rotary table fixture drives the workpiece to rotate 180°. Use milling cutters and drills to perform finish cutting on the rear end face of the tail, the center deep hole and the center hole of the workpiece. The reference for the subsequent machining positioning of the workpiece is machined. During the rough cutting and finish cutting of the workpiece, the spray nozzle on the machining center sprays coolant evenly on the surface of the workpiece to cool it. The coolant flows with the equipment to the storage tank, and then is pumped out and sprayed again.

[0061] S2. Cutting of the workpiece rod: In step S1, after the workpiece reference cutting is completed, the workpiece head center reference hole and tail center hole are used as the clamping center, the workpiece head positioning groove is used for circumferential positioning, and the workpiece head front face is used for axial positioning. The workpiece is clamped on the CNC lathe turning fixture, the workpiece is rotated, and the workpiece rod shape is rough cut with a carbide turning tool. During the machining process, the CNC lathe nozzle sprays coolant to the turning tool tip to cool the tool and the machined part of the workpiece and flush away the chips.

[0062] S3. Workpiece Forming and Cutting: After the workpiece shank is cut in step S2, the workpiece is clamped on a vertical machining center hydraulic rotary table fixture, using the head center reference hole and tail center point hole as the clamping center, the head positioning groove as the circumferential positioning, and the bottom plane of the head center reference hole as the axial positioning. The hydraulic rotary table fixture can drive the workpiece to rotate 360° around the axis (clamping center). According to the dimensions of the workpiece drawing, the locking teeth, assembly groove, helical surface, and other external dimensions of the machine head body are precision machined with a milling cutter to achieve the external cutting of the workpiece. During the machining process, coolant is evenly sprayed onto the position of the milling cutter using a nozzle on the machining center to cool and rinse the tool and the workpiece being machined.

[0063] S4. Heat treatment of the workpiece: The workpiece is quenched and tempered using a vacuum heat treatment process. The quenching temperature is 860℃ and the holding time is 1.8h, with nitrogen cooling. The tempering temperature and time are 220℃ and the holding time is 3.2h. After tempering, the workpiece is taken out and allowed to cool to room temperature in the air.

[0064] S5. Secondary cutting of the workpiece: After heat treatment, the workpiece rod is ground and finished using a conventional cylindrical grinding machine to meet the requirements of the drawing.

[0065] S6. Surface finishing of workpiece: After the workpiece is cut twice, centrifugal rolling is used to finish the surface of the workpiece until the surface is smooth.

[0066] S7. Surface treatment of workpiece: Before coating, the workpiece is first degreased and cleaned by ultrasonication, and then the workpiece is placed in a vacuum coating equipment for diamond-like carbon coating surface treatment. The coating temperature is 100℃, the vacuum degree is (7.5E-3)Pa, and the coating time is 14h.

[0067] Furthermore, in step S1, during rough cutting, a 0.9mm allowance is left on the head of the workpiece, and during finish cutting, the length error range of the workpiece is ±0.04mm, and the hole diameter error range of the workpiece is ±0.02mm.

[0068] Furthermore, in step S1, the coolant is made by diluting the emulsion stock solution with water, and the concentration is 7.5%.

[0069] Furthermore, in step S2, during rough cutting, a 0.15mm allowance is retained in the shape of the workpiece rod.

[0070] Furthermore, in step S5, during precision cutting, the diameter error range of the workpiece rod is ±0.01mm.

[0071] Furthermore, in step S6, when the workpiece surface is finished, a centrifugal high-speed rotation method is used for finishing. The abrasive material is high-frequency ceramic, the loading amount (volume ratio) of the abrasive to the workpiece is 80%, the mass mixing ratio of the abrasive to the workpiece is 1:1.5, and the processing time is 55 minutes.

[0072] Furthermore, in step S7, after the workpiece is coated with diamond-like carbon, the film thickness is 2.5 to 3.5 μm and the surface hardness is 2500 to 3500 HV 15 mN.

[0073] Furthermore, in steps S1, S2, S3, and S5, the waste chips generated during workpiece cutting are collected and recycled.

[0074] Example 3

[0075] A machining process for a rotating bolt head of a firearm includes the following steps:

[0076] S1. Workpiece reference cutting: Fix the forged blank on the hydraulic rotary table fixture of the vertical machining center. Then, according to the dimensions of the workpiece drawing, use different types of milling cutters to perform rough cutting on the head shape of the workpiece, and finish cutting on the front end face of the head, the head center reference hole and the positioning groove. After that, the hydraulic rotary table fixture drives the workpiece to rotate 180°. Use milling cutters and drills to perform finish cutting on the rear end face of the tail, the center deep hole and the center hole of the workpiece. The reference for the subsequent machining positioning of the workpiece is machined. During the rough cutting and finish cutting of the workpiece, the spray nozzle on the machining center sprays coolant evenly on the surface of the workpiece to cool it. The coolant flows with the equipment to the storage tank, and then is pumped out and sprayed again.

[0077] S2. Cutting of the workpiece rod: In step S1, after the workpiece reference cutting is completed, the workpiece head center reference hole and tail center hole are used as the clamping center, the workpiece head positioning groove is used for circumferential positioning, and the workpiece head front face is used for axial positioning. The workpiece is clamped on the CNC lathe turning fixture, the workpiece is rotated, and the workpiece rod shape is rough cut with a carbide turning tool. During the machining process, the CNC lathe nozzle sprays coolant to the turning tool tip to cool the tool and the machined part of the workpiece and flush away the chips.

[0078] S3. Workpiece Forming and Cutting: After the workpiece shank is cut in step S2, the workpiece is clamped on a vertical machining center hydraulic rotary table fixture, using the head center reference hole and tail center point hole as the clamping center, the head positioning groove as the circumferential positioning, and the bottom plane of the head center reference hole as the axial positioning. The hydraulic rotary table fixture can drive the workpiece to rotate 360° around the axis (clamping center). According to the dimensions of the workpiece drawing, the locking teeth, assembly groove, helical surface, and other external dimensions of the machine head body are precision machined with a milling cutter to achieve the external cutting of the workpiece. During the machining process, coolant is evenly sprayed onto the position of the milling cutter using a nozzle on the machining center to cool and rinse the tool and the workpiece being machined.

[0079] S4. Heat treatment of the workpiece: The workpiece is quenched and tempered using a vacuum heat treatment process. The quenching temperature is 900℃ and the holding time is 1.6h, with nitrogen cooling. The tempering temperature and time is 240℃ and the holding time is 3h. After tempering, the workpiece is taken out and allowed to cool to room temperature in the air.

[0080] S5. Secondary cutting of the workpiece: After heat treatment, the workpiece rod is ground and finished using a conventional cylindrical grinding machine to meet the requirements of the drawing.

[0081] S6. Surface finishing of workpiece: After the workpiece is cut twice, centrifugal rolling is used to finish the surface of the workpiece until the surface is smooth.

[0082] S7. Surface treatment of workpiece: Before coating, the workpiece is first degreased and cleaned by ultrasonication, and then the workpiece is placed in a vacuum coating equipment for diamond-like carbon coating surface treatment. The coating temperature is 120℃, the vacuum degree is (7.0E-3)Pa, and the coating time is 16h.

[0083] Furthermore, in step S1, during rough cutting, a 1mm allowance is retained on the shape of the workpiece head; during finish cutting, the workpiece length error range is ±0.05mm, and the workpiece hole diameter error range is ±0.025mm.

[0084] Furthermore, in step S1, the coolant is made by diluting the emulsion stock solution with water, and the concentration is 8%.

[0085] Furthermore, in step S2, during rough cutting, a 0.2mm allowance is retained on the outer shape of the workpiece rod.

[0086] Furthermore, in step S5, during precision cutting, the error range of the workpiece rod diameter is ±0.015mm.

[0087] Furthermore, in step S6, when the workpiece surface is finished, a centrifugal high-speed rotation method is used for finishing. The abrasive material is zirconium oxide, the abrasive to workpiece loading amount (volume ratio) is 85%, the mass mixing ratio of abrasive to workpiece is 1:2, and the processing time is 60 minutes.

[0088] Furthermore, in step S7, after the workpiece is coated with diamond-like carbon, the film thickness is 2.5 to 3.5 μm and the surface hardness is 2500 to 3500 HV 15 mN.

[0089] Furthermore, in steps S1, S2, S3, and S5, the waste chips generated during workpiece cutting are collected and recycled.

[0090] Finally, it should be noted that the above preferred embodiments are only used to illustrate the technical solutions of the present invention and are not intended to limit it. Although the present invention has been described in detail through the above preferred embodiments, those skilled in the art should understand that various changes can be made to it in form and detail without departing from the scope defined by the claims of the present invention.

Claims

1. A method for machining a rotating bolt head body of a firearm, characterized in that, Includes the following steps: S1, Workpiece reference cutting The workpiece-shaped forging blank is clamped on the hydraulic rotary table fixture of the vertical machining center. The head shape of the workpiece is rough machined, and the end face of the head, the central reference hole, and the positioning groove are finish machined. The hydraulic rotary table fixture drives the workpiece to rotate 180°, roughing the tail end face of the workpiece and finishing the deep long hole and center hole at the tail of the workpiece. S2, Workpiece rod cutting Using the center reference hole at the head of the workpiece and the center hole at the tail as the clamping center, the workpiece head positioning groove as the reference for circumferential positioning, and the front end face of the workpiece head as the reference for axial positioning, the workpiece is clamped on the turning fixture of the CNC lathe. The CNC lathe drives the workpiece to rotate and rough-machines the shape of the workpiece rod. S3, Workpiece forming and cutting Using the center reference hole at the head of the workpiece and the center hole at the tail as the clamping center, the workpiece head positioning groove as the reference for circumferential positioning, and the bottom plane of the center reference hole at the head of the workpiece as the reference for axial positioning, the workpiece is clamped on the hydraulic rotary table fixture of the vertical machining center, and the locking teeth, assembly groove, and spiral surface of the machine head body are precision machined. S4. Workpiece heat treatment The workpiece is quenched and tempered using a vacuum heat treatment process. The quenching temperature is 820℃~900℃ and the holding time is 1.5h~2h, with nitrogen cooling. The tempering temperature and time are 200℃~240℃ and the holding time is 3h~3.5h. After tempering, the workpiece is taken out and allowed to cool to room temperature in the air. S5, Secondary cutting of the workpiece The rod portion of the workpiece is precision machined using a conventional cylindrical grinding machine. S6. Surface finishing of the workpiece Centrifugal rolling finishing is used to perform surface finishing on the workpiece; S7. Workpiece Surface Treatment The workpiece is ultrasonically degreased and cleaned, and then placed in a vacuum coating equipment for diamond-like carbon coating surface treatment. The coating temperature is 80℃~120℃, the vacuum degree is ≤ (8.0E-3)Pa, and the coating time is 12h~16.5h.

2. The method for machining a rotating bolt head body of a firearm according to claim 1, characterized in that: In step S1, different types of milling cutters are used to process the workpiece head shape, workpiece head end face, center reference hole, and positioning groove; milling cutter is used to process the workpiece tail end face, and drill bit is used to process the workpiece tail center deep hole and center hole; during the processing, the machining center nozzle sprays coolant evenly onto the workpiece surface to cool the workpiece.

3. The method for machining a rotating bolt head body of a firearm according to claim 1, characterized in that: In step S2, a carbide lathe tool is used to machine the shape of the workpiece rod. During the machining process, the CNC lathe nozzle sprays coolant onto the tool tip to cool the tool and the machined part of the workpiece and remove chips.

4. The method for machining a rotating bolt head body of a firearm according to claim 1, characterized in that: In step S3, a milling cutter is used to process the locking teeth, assembly groove, and spiral surface of the machine head body. During the processing, the machining center nozzle sprays coolant evenly onto the milling cutter position to cool the tool and the workpiece being processed and to flush away the chips.

5. The method for machining a rotating bolt head body of a firearm according to claim 4, characterized in that: The coolant is made by diluting emulsion stock solution with water, and the emulsion concentration is 7% to 8%.

6. The method for machining a rotating bolt head body of a firearm according to claim 1, characterized in that: In step S6, when the workpiece surface is finished, a centrifugal high-speed rotation method is used for finishing. The abrasive material is high-frequency ceramic or zirconia fine polishing abrasive. The volume ratio of abrasive to workpiece is 75% to 85%, the mass mixing ratio of abrasive to workpiece is 1:1 to 2:1, and the processing time is 50 min to 60 min.

7. The method for machining a rotating bolt head body of a firearm according to claim 1, characterized in that: In step S7, after the workpiece is coated with diamond-like carbon, the film thickness is 2.5-3.5 μm and the surface hardness is 2500-3500 HV15 mN.

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