A valve core deburring method

Abstract

The present application relates to a kind of valve core deburring method.The present application includes blanking: according to the outer circle and length of valve core, blanking is carried out with machining allowance; Gun drill: gun drill center deep hole on blank; Processing forming: the workbench shoulder of two ends, support shoulder and annular groove are machined on valve core part, and cross hole is milled on workbench shoulder;Carburizing treatment;Shot blasting: steel ball is used to carry out shot blasting treatment on valve core part;Demagnetization;High pressure flushing;Bore inner hole: hard valve core part outer circle end face is turned, removes outer circle end face carburizing layer, and center deep hole is bored to the required size;Finish machining: workbench shoulder, support shoulder and annular groove of valve core part are finish machined;Deburring: remove the burrs of cross hole and center deep hole;Fine grinding: fine grinding valve core part outer circle, workbench shoulder, support shoulder, annular groove and cross hole, so that the valve core part after fine grinding is kept sharp without burr at each shoulder junction.The present application improves the deburring efficiency and effect of valve core, and improves the output.

Description

TECHNICAL FIELD

[0001] The present application relates to the technical field of valve core manufacturing, in particular to a valve core deburring method. BACKGROUND

[0002] At present, for the deburring of the deep hole valve core of the multi-way valve, the valve core outer circle cannot have any chamfer and cannot have burrs, which leads to the deburring process being completed manually. However, manual polishing of the valve core outer circle burrs not only has low efficiency, but also is prone to missing burrs, which makes it difficult to remove the burrs completely, and even damages the processing surface, and it is difficult to meet the needs of batch production. Using the way of shot blasting to replace manual workpiece polishing operation can well solve these problems.

[0003] However, the traditional shot blasting method has the following problems: 1. The unquenched workpiece cannot withstand the impact force of shot blasting; 2. Shot blasting of the deep hole valve core will cause a small amount of steel balls to remain at positions such as the intersection hole position in the hole, and the remaining steel balls will affect the performance of the valve core; 3. Too large impact force of shot blasting will cause the valve core to fail to ensure sharp chamfer, and too small impact force will cause the valve core to fail to remove the burrs at the root of the milling groove. SUMMARY

[0004] Therefore, the technical problem to be solved by the present application is to overcome the problems of low efficiency, missing burrs, difficulty in removing burrs completely, even damaging the processing surface, and difficulty in meeting the needs of batch production in manual polishing of the valve core outer circle burrs in the prior art.

[0005] To solve the above technical problems, the present application provides a valve core deburring method, comprising the following steps:

[0006] S1, blanking: blanking the blank according to the outer circle and length of the valve core with a processing allowance;

[0007] S2, gun drilling: gun drilling a center deep hole on the blank;

[0008] S3, processing and forming: after turning the end face and outer circle of the blank, a valve core part is obtained, two end table shoulders, support shoulders and an annular groove are turned on the valve core part, an intersection hole is milled on the table shoulder, and a subsequent grinding allowance is left on the outer circle end face;

[0009] S4, carburizing treatment: heat treating the valve core part and forming a carburized layer on the outer circle, and protecting the intersection hole before carburizing;

[0010] S5, shot blasting: using steel balls to perform shot blasting treatment on the valve core part;

[0011] S6, demagnetization: demagnetizing the valve core part;

[0012] S7, high-pressure washing: high-pressure washing the valve core part and performing appearance inspection to ensure that there is no steel ball residue in the valve core part;

[0013] S8, boring: boring the outer circle end face of the valve core part, removing the outer circle end face infiltration layer, and boring the center deep hole to the required size;

[0014] S9, finish machining: finish machining the workbench shoulder, support shoulder and annular groove of the valve core part;

[0015] S9, deburring: removing burrs at the intersection hole and the center deep hole;

[0016] S10, fine grinding: fine grinding the outer circle, workbench shoulder, support shoulder, annular groove and intersection hole of the valve core part, so that the valve core part after fine grinding is sharp and burr-free at the junction of each shoulder.

[0017] In an embodiment of the present application, before step S2, the blank after blanking is placed in a vacuum sintering furnace, and after heating, the temperature is kept constant, then after annealing, the temperature is kept constant again, and then the temperature is lowered.

[0018] In an embodiment of the present application, the temperature is kept constant for 0.5-1h after heating to 700-730℃.

[0019] In an embodiment of the present application, the temperature is kept constant for 1.5-2h after annealing to 500-550℃, and then the temperature is lowered to 25±2℃.

[0020] In an embodiment of the present application, in step S3, a 2±0.5mm allowance is left on the outer circle end face for subsequent grinding.

[0021] In an embodiment of the present application, in step S4, the carburizing temperature is 900±10°C, the carburizing time is 175±10 minutes, and the carbon potential is 1.2±0.05%.

[0022] In an embodiment of the present application, in step S4, the outer circle carburized layer after carburizing treatment is 0.4-0.6mm, and the hardness is HRc58-62.

[0023] In an embodiment of the present application, in step S5, 0.2mm steel balls are used to blast the valve core part for 10±2S.

[0024] In an embodiment of the present application, in step S9, after removing the burrs at the intersection hole and the center deep hole, the burrs are controlled within 0.2mm, and there are no burrs inside the center deep hole.

[0025] In an embodiment of the present application, in step S10, after fine grinding, the outer circle roughness of the valve core part is within Ra0.2μm, and the cylindricity of the outer circle of the valve core part is within 0.001mm.

[0026] The technical solution of the present invention has the following advantages compared with the prior art:

[0027] The present invention discloses a method for deburring valve cores. By using 0.2mm steel balls to perform shot blasting on valve core parts, shot blasting removes surface oxide scale and other impurities, improving appearance quality. During shot blasting, sharp edges and chamfers of the processed parts can be removed simultaneously. By optimizing the process schedule, the reliance on manual deburring for deep-hole valve cores can be eliminated, which can greatly increase output. After the process flow is improved, the output increases from 120 pieces / 8 hours to 1500 pieces / 8 hours, the efficiency is improved by 1150%, and the labor requirements are reduced, thus improving production efficiency. Attached Figure Description

[0028] To make the content of this invention easier to understand, the invention will be further described in detail below with reference to specific embodiments and accompanying drawings, wherein...

[0029] Figure 1 This is a schematic diagram of the three-dimensional structure of the valve core.

[0030] Figure 2 This is a schematic diagram of the main structure of the valve core.

[0031] Figure 3 This is a schematic diagram of the cross-sectional structure of the valve core.

[0032] Explanation of markings in the accompanying drawings: 100, support shoulder; 200, work shoulder; 300, annular groove; 400, central deep hole; 500, cross hole; 600, end face allowance. Detailed Implementation

[0033] The present invention will be further described below with reference to the accompanying drawings and specific embodiments, so that those skilled in the art can better understand and implement the present invention. However, the embodiments described are not intended to limit the present invention.

[0034] Reference Figure 1 As shown, a method for deburring a valve core according to the present invention includes the following steps:

[0035] S1. Blanking: Blank the material according to the outer diameter and length of the valve core, with machining allowance;

[0036] S2. Gun drilling: Drill a deep hole in the center of the blank using a gun drill; the depth of the hole is 9.5mm.

[0037] S3. Machining and forming: After machining the end face and outer circle of the blank, the valve core part is obtained. The working shoulders, support shoulders and annular grooves at both ends are machined on the valve core part. Cross holes are milled on the working shoulders. Allowance is left on the outer circle end face for subsequent grinding.

[0038] S4. Carburizing treatment: The valve core parts are heat-treated and a carburized layer is formed on the outer circle. Before carburizing, the cross holes are protected against seepage.

[0039] S5. Shot blasting: Using steel balls to shot blast the valve core parts;

[0040] S6. Demagnetize: Demagnetize the valve core parts;

[0041] S7. High-pressure flushing: The valve core parts are flushed under high pressure and visually inspected to ensure that there are no steel balls remaining inside the valve core parts.

[0042] S8. Boring the inner hole: Hard turning the outer end face of the valve core part, removing the seepage layer on the outer end face, and boring the center deep hole to the required size;

[0043] S9. Precision turning: Precision turning of the worktable shoulder, support shoulder and annular groove of the valve core parts;

[0044] S9. Deburring: Remove burrs from the cross holes and the central deep hole;

[0045] S10. Fine grinding: Use double-pin positioning valve core parts to fine grind the outer circle, work shoulder, support shoulder, annular groove and cross hole of the valve core parts, so that the finely ground valve core parts are sharp and burr-free at the junction of each shoulder.

[0046] In this embodiment, as Figures 1-3 The valve core has eight shoulders. The leftmost and rightmost shoulders are support shoulders 100, used to connect the coupling. The remaining six shoulders are working shoulders 200. Annular grooves 300 are machined into the working shoulders 200. A central deep hole 400 is machined inside the valve core. Multiple cross holes 500 are opened on the side ends of the working shoulders 200. A 2±0.5mm end face allowance 600 is left on the outer end face for subsequent grinding. During the assembly of the vibration valve, a narrow air cavity is formed between the valve core and the plug. Due to the compressibility of gas, the presence of the air cavity affects the installation accuracy of the valve core. The cross holes 500 allow the air cavity to connect to the T-port of the vibration valve. As the hydraulic circuit removes the gas from the valve, the installation accuracy of the valve core is improved. Multiple cross holes 500 can be opened according to actual needs.

[0047] Specifically, before step S2, the blank after being cut is placed in a vacuum sintering furnace, heated and held under Ar gas protection, then annealed and held again, and then cooled. In this embodiment, the temperature is raised to 700-730℃ and held for 0.5-1h, annealed to 500-550℃ and held for 1.5-2h, and then cooled to 25±2℃.

[0048] Specifically, in step S3, a 2±0.5mm allowance is left on the outer cylindrical end face for subsequent grinding.

[0049] Specifically, in step S4, the carburizing temperature is 900±10°C, the carburizing time is 175±10 minutes, and the carbon potential is 1.2±0.05%.

[0050] Specifically, in step S4, the outer circle carburizing layer after the carburizing treatment is 0.4-0.6mm, and the hardness is HRc58-62.

[0051] Specifically, in step S5, the valve core part is subjected to shot blasting for 10±2S using 0.2mm steel balls, and in the embodiment, a Q236 crawler belt shot blasting machine can be used.

[0052] The shot blasting deburring can cause impact on the surface of the part, and if the hardness of the part itself does not meet the standard, the shot blasting force can be too heavy to cause damage to the part, and in the embodiment, the following shot blasting test is carried out.

[0053] The shot blasting steel balls and the shot blasting duration are selected: starting from 0.5mm steel ball shot blasting for 30S;

[0054] First test: the surface of the valve core part is seriously damaged due to the excessive shot blasting force;

[0055] Using 0.5mm steel balls for 5S processing time: it is found that the damage degree of the surface of the valve core part is reduced, but the burrs are not completely removed;

[0056] Using 0.2mm steel balls for 10S processing time: it is found that the burrs of the valve core part are completely removed, and the surface protection degree is good.

[0057] Specifically, in step S9, a Q236 crawler belt shot blasting machine is used to perform shot blasting on the valve core part for 10±2S using 0.2mm steel balls, and in the embodiment, after removing the burrs at the cross holes and the center deep hole, the burrs are controlled within 0.2mm, and there is no burr inside the center deep hole. The existing manual deburring is completely replaced by shot blasting, which improves the deburring efficiency and effect.

[0058] Specifically, in step S10, after fine grinding, the roughness of the outer circle of the valve core part is within Ra0.2μm, and the cylindricity of the outer circle of the valve core part is within 0.001mm.

[0059] The present application improves the appearance quality by removing surface oxidation scale and other impurities through shot blasting, and at the same time, sharp edges and chamfers of the workpiece can be removed during shot blasting. Through optimization and change of process scheduling, the dependence of deep hole valve core on manual deburring can be eliminated, and the yield can be greatly improved. After improving the process flow, the yield is increased from 120pcs / 8h to 1500pcs / 8h, the efficiency is improved by 1150%, the manual demand is reduced, and the production efficiency is improved.

[0060] Finally, it should be noted that the above embodiments are merely used to illustrate the technical solutions of the present application, rather than limit the present application. Even though the present application has been described in detail with reference to the examples, ordinary technicians in the field shall understand that the technical solutions of the present application can be modified or equivalent replaced, and the modification or replacement shall not depart from the spirit and scope of the technical solutions of the present application. The modification or replacement shall be included in the scope of the claims of the present application.

Claims

1. A valve core deburring method characterized by, It comprises the following steps: S1, blanking: blanking the blank according to the outer circle and length of the valve core with a processing allowance; S2, gun drilling: gun drilling a center deep hole on the blank; S3, machining forming: obtaining the valve core part after turning the end face and outer circle of the blank, turning the workbench shoulder, support shoulder and annular groove on the valve core part, and milling the cross hole on the workbench shoulder, and leaving a margin for subsequent grinding on the outer circle end face; S4, carburizing treatment: heat treating the valve core part and forming a carburized layer on the outer circle, and protecting the cross hole before carburizing; S5, shot blasting: using steel balls to perform shot blasting treatment on the valve core part; S6, demagnetization: demagnetizing the valve core part; S7, high pressure washing: high pressure washing the valve core part and performing appearance inspection to ensure that there is no steel ball residue in the valve core part; S8, boring the inner hole: hard turning the outer circle end face of the valve core part, removing the outer circle end face carburized layer, and boring the center deep hole to the required size; S9, finish turning: finish turning the workbench shoulder, support shoulder and annular groove of the valve core part; S9, deburring: removing the burrs at the cross hole and center deep hole; S10, fine grinding: fine grinding the outer circle, workbench shoulder, support shoulder, annular groove and cross hole of the valve core part, so that the valve core part after fine grinding is sharp and has no burrs at the junction of each shoulder; Before step S2, the blank after blanking is placed in a vacuum sintering furnace, and after heating and then annealing, the blank is again heated and then cooled under the protection of Ar gas; After heating to 700-730℃, the blank is kept for 0.5-1h; Annealing to 500-550℃, keeping for 1.5-2h, and then cooling to 25±2℃; In step S3, leaving a margin of 2±0.5mm for subsequent grinding on the outer circle end face; In step S4, the carburizing temperature is 900±10°C, the carburizing time is 175±10 minutes, and the carbon potential is 1.2±0.05%; In step S4, the outer circle carburized layer after carburizing treatment is 0.4-0.6mm, and the hardness is HRc58-62; In step S5, 0.2mm steel balls are used to perform shot blasting on the valve core part for 10±2S.

2. A valve core deburring method according to claim 1, characterized in that, In step S9, after removing the burrs at the cross hole and center deep hole, the burr control is within 0.2mm, and there is no burr inside the center deep hole.

3. The valve core deburring method of claim 1, wherein, In step S10, after fine grinding, the outer circle roughness of the valve core part is within Ra0.2μm, and the cylindricality of the outer circle of the valve core part is within 0.001mm.

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