A manufacturing process for swing hook of electronic jacquard machine

Abstract

The invention provides a manufacturing process of an electronic jacquard machine swing hook, comprising the following steps: S1: stamping with electrical pure iron to obtain a swing hook prototype; S2: first grinding the surface of the swing hook prototype with sandpaper, and then polishing the swing hook; then performing recrystallization annealing on the obtained swing hook prototype; S3: first spraying liquid nitrogen on the surface of the swing hook obtained by step S2 for 1-2 minutes; then spraying liquid nitrogen on the surface of the swing hook while performing particle shot peening for 5-8 minutes; S4: first heating to 120-135°C in a nitrogen atmosphere, and keeping the temperature for 6-10 hours; then heating to 260-275°C in a nitrogen atmosphere, and keeping the temperature for 5-8 hours; then cooling to room temperature with the furnace; S5: chrome plating on the surface; the invention realizes a significant improvement in surface hardness by combining surface grain refinement and nitriding treatment, so that the wear resistance of the swing hook surface is significantly improved, and the electromagnetic performance of the swing hook is not affected.

Description

Technical Field

[0001] The invention relates to the technical field of electronic jacquard machines, and in particular to a manufacturing process for a swing hook of an electronic jacquard machine. Background Art

[0002] The swing hook of the electronic jacquard machine, also known as the electronic pattern needle or electronic jacquard needle, is a key component in the electronic jacquard machine. Its main function is to control the lifting and lowering of the warp yarn to form a specific fabric pattern. The electronic jacquard machine controls the lifting and lowering of the swing hook (electronic pattern needle) through the solenoid valve. There is a pair of hooks under each solenoid valve, and the wire handle can be hung under the hook. This structure makes the hook and the corresponding solenoid valve can be regarded as an electronic pattern needle. When the solenoid valve is energized, the swing hook is lifted, and the corresponding warp yarn is also lifted to form the upper layer of the shed and obtain the warp tissue point; when the solenoid valve is not energized, the swing hook drops, and the warp yarn also drops with it to form the lower layer of the shed and obtain the weft tissue point. In short, the swing hook of the electronic jacquard machine is a key component for realizing fabric jacquard. Through the precise control of the solenoid valve, it can quickly and accurately control the lifting and lowering of the warp yarn to form a designed jacquard pattern.

[0003] However, the wear and failure of the swing hook will seriously restrict the normal operation of the electronic jacquard machine. During the alternating movement of the mechanical drive, the lifting knife moves up and down alternately due to the mechanical drive. This high-frequency knocking suction may cause the swing hook to produce impact wear. In addition, multiple moving parts inside the needle lifting assembly need to be manually greased and lubricated. When the grease is stained with flying flowers and other debris, it affects the lubrication effect and causes wear. The electromagnet has high requirements for heat dissipation. Under high-speed, high-temperature and low-heat dissipation conditions, the fulcrum shaft is more prone to wear. The material and manufacturing process of the swing hook may affect its wear resistance and durability, leading to early wear and failure.

[0004] At present, there is an obvious difference in lifespan between domestic electronic swing hooks and foreign products. Among them, the performance difference of the swing hook itself is the main factor affecting its service life. Therefore, it is necessary to propose an innovative manufacturing process for the swing hook to solve the problem of poor lifespan caused by insufficient performance of the swing hook. Summary of the invention

[0005] The purpose of the present invention is to provide a manufacturing process for an electronic jacquard machine swing hook. The process comprises the steps of pure iron stamping, recrystallization annealing, liquid nitrogen injection / microparticle shot peening, diffusion nitriding treatment, surface chrome plating, etc., and the surface hardness is significantly improved by combining surface grain refinement and nitriding treatment, thereby significantly improving the wear resistance of the swing hook surface, and does not affect the electromagnetic properties of the swing hook.

[0006] To achieve the above objectives, the present invention is implemented through the following technical solutions: A manufacturing process of an electronic jacquard machine swing hook comprises the following steps: S1: Electrical pure iron is used for stamping to obtain a swing hook prototype; S2: firstly grind the surface of the swing hook prototype with sandpaper, and then polish the swing hook; then perform recrystallization annealing on the obtained swing hook prototype; S3: first spraying liquid nitrogen onto the surface of the swing hook obtained in step S2 for 1 to 2 minutes; then performing particle shot peening for 5 to 8 minutes while spraying liquid nitrogen onto the surface of the swing hook; S4: First, heat to 120-135°C in a nitrogen atmosphere and keep warm for 6-10 hours; then heat to 260-275°C in a nitrogen atmosphere and keep warm for 5-8 hours; then cool to room temperature with the furnace; S5: The swing hook obtained in step S4 is subjected to surface chrome plating.

[0007] Preferably, in step S2, the temperature of the recrystallization annealing treatment is 800-900° C., and the holding time is 40-50 min.

[0008] Preferably, in step S2, when the recrystallization annealing treatment is performed in a vacuum environment, the vacuum degree is 10 -1 ~10 - 2 Pa.

[0009] Preferably, in step S3, the distance between the nozzle for spraying liquid nitrogen and the surface of the swing hook is 8-10 cm, the distance between the nozzle of the spray gun for particle shot peening and the surface of the swing hook is 12-15 cm, and the pressure of the particle shot peening is 0.2-0.4 MPa.

[0010] Preferably, in step S3, during the particle shot peening treatment, the projectiles used are stainless steel spherical projectiles with a particle size of 100-200 μm; the hardness of the projectiles is HRC50-60.

[0011] Preferably, in step S4, the temperature is raised to 120-135°C at a rate of 3-6°C / min; and the temperature is raised to 260-275°C at a rate of 5-10°C / min.

[0012] Preferably, in step S2, the surface of the swing hook prototype is polished with 240 mesh, 320 mesh, 600 mesh, 800 mesh, and 1000 mesh sandpaper in sequence, and then the swing hook is polished to make the average roughness of the swing hook 3~6μm.

[0013] Preferably, in step S5, the chromium plating solution used for the chromium plating treatment comprises: 200-260 g / L of chromic anhydride, 1.3-1.5 g / L of concentrated sulfuric acid, and 0.1-0.3 g / L of oxalic acid; the current density during the chromium plating treatment is 25-50 A / dm 2, temperature is 50~60℃, time is 12~15min.

[0014] The beneficial effects of the present invention are: 1. The present invention sprays liquid nitrogen on the swing hook after recrystallization annealing, and then performs microparticle shot peening while spraying liquid nitrogen, so as to construct a gradient hardening layer on the surface of the swing hook. During the shot peening deformation process, nitrogen atoms will combine with the surface tissue. In the next process, heating in a nitrogen atmosphere (diffusion nitriding treatment) is performed to diffuse nitrogen atoms into the surface tissue to form a nitrided layer, thereby effectively improving the hardness of the swing hook surface.

[0015] 2. The present invention processes the swing hook by combining micro-particle shot peening with liquid nitrogen injection, so that the swing hook can be shot peened at low temperature. At a lower temperature, the thermal motion of atoms slows down, thereby effectively inhibiting the occurrence of dynamic recovery and increasing the dislocation density of the surface structure, thereby increasing the surface hardness and grain refinement of the swing hook.

[0016] 3. The present invention sprays liquid nitrogen on the surface of the swing hook before spraying liquid nitrogen and performing microparticle shot peening, which can keep the swing hook as a whole in a uniform low-temperature state and make the crystal structure more stable and uniform. Combined with subsequent treatments, the surface hardness and grain refinement of the swing hook can be further improved.

[0017] 4. The swing hook of the present invention is heat treated in a nitrogen atmosphere, and a two-step heating treatment is used to achieve diffusion nitriding. By optimizing the setting temperature and the insulation time, etc., the hardness of the nitrided layer is better improved.

[0018] 5. The present invention performs recrystallization annealing treatment to ensure uniform pure iron structure and release the internal stress generated by stamping. BRIEF DESCRIPTION OF THE DRAWINGS

[0019] In order to more clearly illustrate the embodiments of the present invention or the technical solutions in the prior art, the drawings required for use in the embodiments or the description of the prior art will be briefly introduced below. Obviously, the drawings described below are only some embodiments of the present invention. For ordinary technicians in this field, other drawings can be obtained based on these drawings without paying creative work.

[0020] Figure 1 The present invention is a process flow chart of the manufacturing process of the swing hook of the electronic jacquard machine; Figure 2 This is the microstructure diagram of the swing hook prepared in step S4 in Example 1 of the present invention. DETAILED DESCRIPTION

[0021] In order to make the purpose, technical solution and advantages of the embodiments of the present invention clearer, the technical solution in the embodiments of the present invention will be clearly and completely described below in combination with the embodiments of the present invention. Obviously, the described embodiments are part of the embodiments of the present invention, not all of the embodiments. Based on the embodiments of the present invention, all other embodiments obtained by ordinary technicians in this field without creative work are within the scope of protection of the present invention.

[0022] Embodiment 1: A manufacturing process of an electronic jacquard machine swing hook, the process flow chart is as follows Figure 1 As shown, the following steps are included: S1: Electrical pure iron is used for stamping to obtain a swing hook prototype; S2: First, the surface of the swing hook prototype was polished with 240 mesh, 320 mesh, 600 mesh, 800 mesh, and 1000 mesh sandpaper in sequence, and then the swing hook was polished to make the average roughness of the swing hook 5.2 μm; then the swing hook prototype was recrystallized annealed in a vacuum environment; the recrystallization annealing temperature was 850 ° C, the holding time was 45 min; the vacuum degree was 10 -1 Pa; S3: first spraying liquid nitrogen onto the surface of the swing hook obtained in step S2 for 2 minutes; then performing particle shot peening for 7 minutes while spraying liquid nitrogen onto the surface of the swing hook; The distance between the nozzle for spraying liquid nitrogen and the surface of the swing hook is 10 cm, the distance between the nozzle of the spray gun for particle shot peening and the surface of the swing hook is 13 cm, and the pressure of the particle shot peening is 0.3 MPa. In the particle shot peening treatment, the projectiles used are stainless steel spherical projectiles with a particle size of 100~200μm; the hardness of the projectiles is HRC56; S4: placing the swing hook obtained in step S3 in a heating furnace, first heating it to 130°C at a rate of 5°C / min in a nitrogen atmosphere, and keeping it warm for 9 hours; then heating it to 270°C at a rate of 9°C / min in a nitrogen atmosphere, and keeping it warm for 6 hours; then cooling it to room temperature with the furnace; the microstructure of the swing hook prepared is shown in Figure 2 As shown, the degree of grain refinement.

[0023] S5: The swing hook obtained in step S4 is subjected to surface chrome plating treatment; the chrome plating solution used for the chrome plating treatment includes: 220g / L chromic anhydride, 1.5g / L concentrated sulfuric acid, and 0.2g / L oxalic acid; the current density during the chrome plating treatment is 40A / dm 2 , temperature is 55℃, time is 12min.

[0024] Embodiment 2: A manufacturing process of an electronic jacquard machine swing hook comprises the following steps: S1: Electrical pure iron is used for stamping to obtain a swing hook prototype; S2: First, the surface of the swing hook prototype was polished with 240 mesh, 320 mesh, 600 mesh, 800 mesh, and 1000 mesh sandpaper in sequence, and then the swing hook was polished to make the average roughness of the swing hook 5.8 μm; then the swing hook prototype was recrystallized annealed in a vacuum environment; the recrystallization annealing temperature was 900 ° C, the holding time was 45 min; the vacuum degree was 10 -2 Pa; S3: first spraying liquid nitrogen onto the surface of the swing hook obtained in step S2 for 2 minutes; then performing particle shot peening for 5 minutes while spraying liquid nitrogen onto the surface of the swing hook; The distance between the nozzle for spraying liquid nitrogen and the surface of the swing hook is 8 cm, the distance between the nozzle of the spray gun for particle shot peening and the surface of the swing hook is 12 cm, and the pressure of the particle shot peening is 0.2 MPa. In the particle shot peening treatment, the projectiles used are stainless steel spherical projectiles with a particle size of 100~200μm; the hardness of the projectiles is HRC50; S4: placing the swing hook obtained in step S3 in a heating furnace, first heating it to 135°C at a rate of 3°C / min in a nitrogen atmosphere, and keeping it warm for 10 hours; then heating it to 265°C at a rate of 10°C / min in a nitrogen atmosphere, and keeping it warm for 6 hours; and then cooling it to room temperature in the furnace; S5: The swing hook obtained in step S4 is subjected to surface chrome plating treatment; the chrome plating solution used for the chrome plating treatment includes: 220g / L chromic anhydride, 1.5g / L concentrated sulfuric acid, and 0.2g / L oxalic acid; the current density during the chrome plating treatment is 40A / dm 2 , temperature is 55℃, time is 12min.

[0025] Embodiment 3: A manufacturing process of an electronic jacquard machine swing hook comprises the following steps: S1: Electrical pure iron is used for stamping to obtain a swing hook prototype; S2: First, the surface of the swing hook prototype was polished with 240 mesh, 320 mesh, 600 mesh, 800 mesh, and 1000 mesh sandpaper in turn, and then the swing hook was polished to make the average roughness of the swing hook 3-6 μm; then the swing hook prototype was recrystallized and annealed in a vacuum environment; the temperature of the recrystallization annealing treatment was 820 °C, the holding time was 40 min; the vacuum degree was 5 × 10 -2 Pa.

[0026] S3: first spraying liquid nitrogen onto the surface of the swing hook obtained in step S2 for 1.5 minutes; then performing particle shot peening for 6 minutes while spraying liquid nitrogen onto the surface of the swing hook; The distance between the nozzle for spraying liquid nitrogen and the surface of the swing hook is 8 cm, the distance between the nozzle of the spray gun for particle shot peening and the surface of the swing hook is 15 cm, and the pressure of the particle shot peening is 0.2 MPa. In the particle shot peening treatment, the projectiles used are stainless steel spherical projectiles with a particle size of 100~200μm; the hardness of the projectiles is HRC60; S4: placing the swing hook obtained in step S3 in a heating furnace, first heating it to 135°C at a rate of 6°C / min in a nitrogen atmosphere, and keeping it at that temperature for 6 hours; then heating it to 275°C at a rate of 8°C / min in a nitrogen atmosphere, and keeping it at that temperature for 6 hours; and then cooling it to room temperature in the furnace; S5: The swing hook obtained in step S4 is subjected to surface chrome plating treatment; the chrome plating solution used for the chrome plating treatment includes: 220g / L chromic anhydride, 1.5g / L concentrated sulfuric acid, and 0.2g / L oxalic acid; the current density during the chrome plating treatment is 40A / dm 2 , temperature is 55℃, time is 12min.

[0027] Embodiment 4: A manufacturing process of an electronic jacquard machine swing hook comprises the following steps: S1: Electrical pure iron is used for stamping to obtain a swing hook prototype; S2: First, the surface of the swing hook prototype was polished with 240 mesh, 320 mesh, 600 mesh, 800 mesh, and 1000 mesh sandpaper in sequence, and then the swing hook was polished to make the average roughness of the swing hook 3.5 μm; then the swing hook prototype was recrystallized annealed in a vacuum environment; the recrystallization annealing temperature was 880 ° C, the holding time was 45 min; the vacuum degree was 10 -1 Pa; S3: first spraying liquid nitrogen onto the surface of the swing hook obtained in step S2 for 1 minute; then performing particle shot peening for 6 minutes while spraying liquid nitrogen onto the surface of the swing hook; The distance between the nozzle for spraying liquid nitrogen and the surface of the swing hook is 9 cm, the distance between the nozzle of the spray gun for particle shot peening and the surface of the swing hook is 12 cm, and the pressure of the particle shot peening is 0.3 MPa. In the particle shot peening treatment, the projectiles used are stainless steel spherical projectiles with a particle size of 100~200μm; the hardness of the projectiles is HRC60; S4: placing the swing hook obtained in step S3 in a heating furnace, first heating it to 125°C at a rate of 5°C / min under a nitrogen atmosphere, and keeping it warm for 10 hours; then heating it to 260°C at a rate of 5°C / min under a nitrogen atmosphere, and keeping it warm for 5 hours; and then cooling it to room temperature with the furnace; S5: The swing hook obtained in step S4 is subjected to surface chrome plating treatment; the chrome plating solution used for the chrome plating treatment includes: 255g / L chromic anhydride, 1.3g / L concentrated sulfuric acid, and 0.3g / L oxalic acid; the current density during the chrome plating treatment is 35A / dm 2 , temperature is 55℃, time is 15min.

[0028] Embodiment 5: A manufacturing process of an electronic jacquard machine swing hook comprises the following steps: S1: Electrical pure iron is used for stamping to obtain a swing hook prototype; S2: First, the surface of the swing hook prototype was polished with 240 mesh, 320 mesh, 600 mesh, 800 mesh, and 1000 mesh sandpaper in sequence, and then the swing hook was polished to make the average roughness of the swing hook 3 μm; then the swing hook prototype was recrystallized annealed in a vacuum environment; the recrystallization annealing temperature was 830 ° C, the holding time was 45 min; the vacuum degree was 10 -1 Pa; S3: first spraying liquid nitrogen onto the surface of the swing hook obtained in step S2 for 1 minute; then performing particle shot peening treatment for 8 minutes while spraying liquid nitrogen onto the surface of the swing hook; The distance between the nozzle for spraying liquid nitrogen and the surface of the swing hook is 8 cm, the distance between the nozzle of the spray gun for particle shot peening and the surface of the swing hook is 13 cm, and the pressure of the particle shot peening is 0.2 MPa. In the particle shot peening treatment, the projectiles used are stainless steel spherical projectiles with a particle size of 100~200μm; the hardness of the projectiles is HRC50; S4: placing the swing hook obtained in step S3 in a heating furnace, first heating it to 120°C at a rate of 6°C / min under a nitrogen atmosphere, and keeping it warm for 8 hours; then heating it to 260°C at a rate of 8°C / min under a nitrogen atmosphere, and keeping it warm for 5 hours; and then cooling it to room temperature along with the furnace; S5: The swing hook obtained in step S4 is subjected to surface chrome plating treatment; the chrome plating solution used for the chrome plating treatment includes: 255g / L chromic anhydride, 1.3g / L concentrated sulfuric acid, and 0.3g / L oxalic acid; the current density during the chrome plating treatment is 35A / dm 2 , temperature is 55℃, time is 15min.

[0029] Embodiment 6: A manufacturing process of an electronic jacquard machine swing hook comprises the following steps: S1: Electrical pure iron is used for stamping to obtain a swing hook prototype; S2: First, the surface of the swing hook prototype was polished with 240 mesh, 320 mesh, 600 mesh, 800 mesh, and 1000 mesh sandpaper in turn, and then the swing hook was polished to make the average roughness of the swing hook 6 μm; then the swing hook prototype was recrystallized annealed in a vacuum environment; the recrystallization annealing temperature was 800 ° C, the holding time was 40 min; the vacuum degree was 5×10 -2 Pa; S3: first spraying liquid nitrogen onto the surface of the swing hook obtained in step S2 for 2 minutes; then performing particle shot peening for 6 minutes while spraying liquid nitrogen onto the surface of the swing hook; The distance between the nozzle for spraying liquid nitrogen and the surface of the swing hook is 10 cm, the distance between the nozzle of the spray gun for particle shot peening and the surface of the swing hook is 15 cm, and the pressure of the particle shot peening is 0.4 MPa. In the particle shot peening treatment, the projectiles used are stainless steel spherical projectiles with a particle size of 100~200μm; the hardness of the projectiles is HRC56; S4: placing the swing hook obtained in step S3 in a heating furnace, first heating the temperature to 135° C. at a rate of 3° C. / min under a nitrogen atmosphere, and keeping the temperature for 10 hours; then heating the temperature to 275° C. at a rate of 5° C. / min under a nitrogen atmosphere, and keeping the temperature for 8 hours; S5: The swing hook obtained in step S4 is subjected to surface chrome plating treatment; the chrome plating solution used for the chrome plating treatment includes: 255g / L chromic anhydride, 1.3g / L concentrated sulfuric acid, and 0.3g / L oxalic acid; the current density during the chrome plating treatment is 35A / dm 2 , temperature is 55℃, time is 15min.

[0030] Embodiment 7: A manufacturing process of an electronic jacquard machine swing hook comprises the following steps: S1: Electrical pure iron is used for stamping to obtain a swing hook prototype; S2: First, the surface of the swing hook prototype was polished with 240 mesh, 320 mesh, 600 mesh, 800 mesh, and 1000 mesh sandpaper in sequence, and then the swing hook was polished to make the average roughness of the swing hook 4.5 μm; then the swing hook prototype was recrystallized annealed in a vacuum environment; the temperature of the recrystallization annealing treatment was 900 ° C, the holding time was 50 min; the vacuum degree was 5×10 -2 Pa; S3: first spraying liquid nitrogen onto the surface of the swing hook obtained in step S2 for 1.5 minutes; then performing particle shot peening for 5 minutes while spraying liquid nitrogen onto the surface of the swing hook; The distance between the nozzle for spraying liquid nitrogen and the surface of the swing hook is 9 cm, the distance between the nozzle of the spray gun for particle shot peening and the surface of the swing hook is 12 cm, and the pressure of the particle shot peening is 0.3 MPa. In the particle shot peening treatment, the projectiles used are stainless steel spherical projectiles with a particle size of 100~200μm; the hardness of the projectiles is HRC60; S4: placing the swing hook obtained in step S3 in a heating furnace, first heating the temperature to 130° C. at a rate of 4° C. / min in a nitrogen atmosphere, and keeping the temperature for 6 hours; then heating the temperature to 270° C. at a rate of 10° C. / min in a nitrogen atmosphere, and keeping the temperature for 7 hours; S5: The swing hook obtained in step S4 is subjected to surface chrome plating treatment; the chrome plating solution used for the chrome plating treatment includes: 220g / L chromic anhydride, 1.5g / L concentrated sulfuric acid, and 0.2g / L oxalic acid; the current density during the chrome plating treatment is 40A / dm 2 , temperature is 55℃, time is 12min.

[0031] Comparative Example 1: Different from Example 1, step S4 includes the following steps: placing the swing hook obtained in step S3 in a heating furnace, heating it to 130°C at a rate of 5°C / min under a nitrogen atmosphere, and keeping it warm for 15 hours; then cooling it to room temperature with the furnace.

[0032] The remaining steps are consistent with those in Example 1.

[0033] Comparative Example 2: Different from Example 1, step S4 includes the following steps: placing the swing hook obtained in step S3 in a heating furnace, heating it to 270°C at a rate of 9°C / min under a nitrogen atmosphere, and keeping it warm for 15 hours; then cooling it to room temperature with the furnace.

[0034] The remaining steps are consistent with those in Example 1.

[0035] Comparative Example 3: Different from Example 1, step S4 includes the following steps: placing the swing hook obtained in step S3 in a heating furnace, first heating it to 170°C at a rate of 5°C / min under a nitrogen atmosphere, and keeping it warm for 12 hours; then heating it to 350°C at a rate of 9°C / min under a nitrogen atmosphere, and keeping it warm for 3 hours; and then cooling it to room temperature with the furnace.

[0036] The remaining steps are consistent with those in Example 1.

[0037] Comparative Example 4: Different from the embodiment 1, step S3 includes the following steps: spraying liquid nitrogen onto the surface of the swing hook obtained in step S2 while performing particle shot peening for 7 minutes; The distance between the nozzle for spraying liquid nitrogen and the surface of the swing hook is 10 cm, the distance between the nozzle of the spray gun for particle shot peening and the surface of the swing hook is 13 cm, and the pressure of the particle shot peening is 0.3 MPa. During the particle shot peening treatment, the projectiles used are stainless steel spherical projectiles with a particle size of 100~200μm; the hardness of the projectiles is HRC56.

[0038] The remaining steps are consistent with those in Example 1.

[0039] Comparative Example 5: Different from the embodiment 1, step S3 includes the following steps: firstly, the surface of the swing hook obtained in step S2 is subjected to a particle shot peening treatment for 7 minutes; The distance between the nozzle of the spray gun for particle shot peening and the surface of the swing hook is 13 cm, and the pressure of the particle shot peening is 0.3 MPa. In the particle shot peening treatment, the projectiles used are stainless steel spherical projectiles with a particle size of 100~200μm; the hardness of the projectiles is HRC56; The remaining steps are consistent with those in Example 1.

[0040] test: The surface hardness test was performed on the swing hook obtained in step S4 of Examples 1 to 7 and Comparative Examples 1 to 5. The specific test results are shown in Table 1.

[0041] Table 1 Hardness test results Hardness (HV) Example 1 325 Example 2 338 Example 3 319 Example 4 340 Example 5 331 Example 6 329 Example 7 322 Comparative Example 1 288 Comparative Example 2 281 Comparative Example 3 278 Comparative Example 4 302 Comparative Example 5 233

[0042] In Table 1, when Example 1 is compared with Comparative Examples 1 and 2, if only one-step method is used for heat diffusion nitriding treatment, the surface hardness of the swing hook obtained after this step is significantly reduced. When Example 1 is compared with Comparative Example 3, if the treatment temperature and the holding time are changed, the surface hardness obtained is also significantly reduced. By comparing Example 1 and Comparative Example 4, it can be seen that if liquid nitrogen is not sprayed on the surface of the swing hook first, the surface hardness of the swing hook after the heat diffusion nitriding treatment will decrease. When Example 1 is compared with Comparative Examples 1 and 2, if liquid nitrogen is not sprayed before and during the microparticle shot peening treatment, the surface hardness of the swing hook after the heat diffusion nitriding treatment will decrease significantly.

[0043] The above embodiments are only used to illustrate the technical solutions of the present invention, rather than to limit the same. Although the present invention has been described in detail with reference to the aforementioned embodiments, those skilled in the art should understand that the technical solutions described in the aforementioned embodiments may still be modified, or some of the technical features may be replaced by equivalents. However, these modifications or replacements do not deviate the essence of the corresponding technical solutions from the spirit and scope of the technical solutions of the embodiments of the present invention.

Claims

1. A manufacturing process for an electronic jacquard machine swing hook, characterized in that: The following steps are involved: S1: Electrical pure iron is used for stamping to obtain a swing hook prototype; S2: firstly grind the surface of the swing hook prototype with sandpaper, and then polish the swing hook; then perform recrystallization annealing on the obtained swing hook prototype; S3: first spraying liquid nitrogen onto the surface of the swing hook obtained in step S2 for 1 to 2 minutes; then performing particle shot peening for 5 to 8 minutes while spraying liquid nitrogen onto the surface of the swing hook; S4: First, heat to 120-135°C in a nitrogen atmosphere and keep warm for 6-10 hours; then heat to 260-275°C in a nitrogen atmosphere and keep warm for 5-8 hours; then cool to room temperature with the furnace; S5: The swing hook obtained in step S4 is subjected to surface chrome plating.

2. The manufacturing process of the swing hook of the electronic jacquard machine according to claim 1 is characterized in that: In step S2, the temperature of the recrystallization annealing treatment is 800-900°C, and the holding time is 40-50 minutes.

3. The manufacturing process of the swing hook of the electronic jacquard machine according to claim 1 is characterized in that: In step S2, when the recrystallization annealing treatment is performed in a vacuum environment, the vacuum degree is 10 -1 ~10 -2 Pa.

4. The manufacturing process of the swing hook of the electronic jacquard machine according to claim 1 is characterized in that: In step S3, the distance between the nozzle for spraying liquid nitrogen and the surface of the swing hook is 8-10 cm, the distance between the nozzle of the spray gun for particle shot peening and the surface of the swing hook is 12-15 cm, and the pressure of the particle shot peening is 0.2-0.4 MPa.

5. The manufacturing process of the swing hook of the electronic jacquard machine according to claim 1 is characterized in that: In step S3, during the particle shot peening treatment, the projectiles used are stainless steel spherical projectiles with a particle size of 100-200 μm; the hardness of the projectiles is HRC50-60.

6. The manufacturing process of the swing hook of the electronic jacquard machine according to any one of claims 1 to 5, characterized in that: In step S4, the temperature is raised to 120-135°C at a rate of 3-6°C / min; and the temperature is raised to 260-275°C at a rate of 5-10°C / min.

7. The manufacturing process of the swing hook of the electronic jacquard machine according to any one of claims 1 to 5, characterized in that: In step S2, the surface of the swing hook prototype is polished with 240 mesh, 320 mesh, 600 mesh, 800 mesh, and 1000 mesh sandpaper in sequence, and then the swing hook is polished to make the average roughness of the swing hook 3~6μm.

8. The manufacturing process of the swing hook of the electronic jacquard machine according to any one of claims 1 to 5, characterized in that: In step S5, the chromium plating solution used for the chromium plating treatment includes: chromic anhydride 200-260 g / L, concentrated sulfuric acid 1.3-1.5 g / L, oxalic acid 0.1-0.3 g / L; the current density during the chromium plating treatment is 25-50 A / dm 2 , temperature is 50~60℃, time is 12~15min.

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