A processing method for a shift control valve

Abstract

The invention discloses a processing method for a shift control valve, and the main steps are as follows: blanking → heat treatment → turning → turning → turning → turning → boring → drilling → boring → milling and clamping → milling and clamping → heat treatment → straightening → clamping → turning → grinding → clamping → heat treatment → clamping → grinding → clamping → warehousing. The invention effectively connects ordinary machine tools and numerical control machine tools, gives full play to the advantages of various machine tools, and inserts reasonable heat treatment and auxiliary processes, making its processing flow more reasonable and the operation method simple. For the shift control valve processed by the processing method described in the invention, the qualified rate of workpieces is 100%, the processing time is shortened by 23% compared with the original method, and the processing cost is reduced by 12%. The wear resistance and precision of the shift control valve are improved, thereby improving the stability and service life of the shift controller assembly.

Description

Technical Field

[0001] The present invention belongs to the technical field of machining, and particularly relates to a machining method for a shift control valve. Background Art

[0002] The shift control valve is one of the important components in the shift controller assembly. In order to improve the stability and service life of the shift controller assembly, the shift control valve has relatively high precision requirements, with a hardness HV>700, a dimensional accuracy IT6, a geometric tolerance grade of 6, and a surface roughness Ra0.4. Since the shift control valve is a special-shaped shaft part with relatively high precision requirements, it is prone to deformation during the machining process, and the machining difficulty is great. The parts machined by the existing machining methods are prone to deformation, and the dimensions are unstable, which cannot meet the design requirements. Sometimes, when the parts stored in the warehouse are taken out for assembly, they cannot be used due to the changes in the parts. Therefore, there is an urgent need for a quality-guaranteed, stable, and economical machining method to meet the design and production requirements. Summary of the Invention

[0003] In order to solve the above problems, the present invention aims to provide a machining method for a shift control valve.

[0004] In order to achieve the above purpose, the present invention adopts the following technical solutions:

[0005] A machining method for a shift control valve, characterized in that it includes the following steps:

[0006] Step 1: Cut the workpiece according to the outer diameter and length with machining allowances.

[0007] Step 2: Heat treatment, normalizing.

[0008] Step 3: Turning, turning the end face, drilling the center hole, rough turning the large outer diameter and the small outer diameter, and leaving allowances for the outer diameter.

[0009] Step 4: Turning, clamping the small outer diameter, supporting the center hole, turning the outer diameter, the annular groove, and the shaped surface R, leaving allowances for the large outer diameter, and machining the rest to the requirements.

[0010] Step 5: Turning, positioning the workpiece with a double-opening bushing, clamping the bushing, supporting the center hole, turning the outer diameter and the relief groove, leaving allowances for the outer diameter, and machining the rest to the requirements.

[0011] Step 6: Turning, positioning the workpiece with a double-opening bushing, clamping the bushing, turning the end face, and controlling the length dimension.

[0012] Step 7: Boring, aligning the outer diameter, drilling and boring the end hole of the shaft, and chamfering.

[0013] Step 8: Drilling, aligning the outer diameter, and drilling two deep holes.

[0014] Step 9: Boring, aligning the outer diameter and the hole, boring the plug holes at the two deep holes, and chamfering.

[0015] Step 10: Milling and clamping process. Clamp the workpiece with a milling fixture, mill a straight groove, and remove burrs by clamping process.

[0016] Step 11: Milling and clamping process. Clamp the workpiece with a milling fixture, mill an R groove, and remove burrs by clamping process.

[0017] Step 12: Heat treatment to eliminate stress.

[0018] Step 13: Straighten the workpiece.

[0019] Step 14: Clamping process. Cast low-melting-point alloy into the holes and grooves of the workpiece.

[0020] Step 15: Turning process. Calibrate the outer diameter, and use a conical center for the tailstock.

[0021] Step 16: Grinding process. Mount the workpiece with a special internal center and a standard center, grind two outer diameters, and leave a margin.

[0022] Step 17: Clamping process. Remove burrs after melting the low-melting-point alloy.

[0023] Step 18: Heat treatment, nitriding treatment.

[0024] Step 19: Clamping process. Cast low-melting-point alloy into the holes and grooves of the workpiece.

[0025] Step 20: Grinding process. Mount the workpiece with a special center and a standard center, and precisely grind two outer diameters to the requirements of the design drawing.

[0026] Step 21: Clamping process. Remove burrs after melting the low-melting-point alloy.

[0027] Step 22: Store in the warehouse.

[0028] In the said Step 1, the length dimension includes the length of the process block.

[0029] The margin left for the outer diameter in Step 3 is 1 mm to 1.5 mm, and the margins left for the outer diameter in Steps 4 and 5 are both 0.35 mm to 0.5 mm.

[0030] The double-opening bushing turned in Step 5 is a two-piece opening bushing. The inner hole of the bushing fits with the outer diameter of the workpiece, and is 0.06 mm to 0.12 mm larger than the outer diameter of the workpiece. One end of the bushing has an inner step and an outer step. The inner step is inserted into the annular groove of the workpiece for lateral positioning, and the side of the outer step abuts against the end face of the three-jaw chuck of the machine tool for axial positioning.

[0031] For the milling processes in Steps 10 and 11, clamp the workpiece with a milling fixture, then clamp the milling fixture with a vise, align the milling cutter, and mill the straight groove and the R groove.

[0032] The milling fixtures are a straight groove milling fixture and an R groove milling fixture respectively. The two milling fixtures are mainly composed of a double-opening clamping sleeve, an axial positioning plate and a positioning pin. The inner hole of the double-opening clamping sleeve fits with the outer circle of the workpiece, and is 0.06 mm to 0.12 mm larger than the outer circle of the workpiece. The double-opening clamping sleeve of the straight groove milling fixture is machined into a straight groove, and the double-opening clamping sleeve of the R groove milling fixture is machined into an R groove. The axial positioning plate is fixed to one end of a clamping sleeve with a cylindrical pin and a bolt to position the axial position of the workpiece. The positioning pin is installed on the axial positioning plate. One end of the positioning pin is in interference fit with the hole of the axial positioning plate, and the other end is in clearance fit with the plug hole of the workpiece to limit the angular position of the workpiece.

[0033] In step 13, straighten the workpiece with a straightening machine, and check that the runout between the R surface of the profile and the large outer circle of the workpiece is not greater than 0.07 mm.

[0034] In steps 14 and 19, pour low-melting-point alloy, dry the single-opening clamping sleeve and the workpiece, clamp the outer circle of the workpiece with the single-opening clamping sleeve, and pour low-melting-point alloy from one hole of the workpiece until the holes and grooves of the workpiece are filled with low-melting-point alloy.

[0035] In step 15, calibrate the large outer circle, and the runout is not greater than 0.05 mm. Machine the large-end outer conical surface at 60°, and machine the inner conical surface of the small-end center hole at 60°.

[0036] In step 16 of grinding, use a special internal center at one end and a standard center at the other end to hold the workpiece, grind the two outer circles respectively, leave a margin of 0.09 mm to 0.15 mm on the outer circles, and the coaxiality between the outer circles and the 60° conical surfaces at both ends is 0.04 mm to 0.07 mm.

[0037] Step 17 is to hang the workpiece in the oil tank and heat it to 140 °C to 150 °C to melt the low-melting-point alloy.

[0038] Compared with the prior art, the present invention has the following advantages: The ordinary machine tool is effectively connected with the numerical control machine tool, giving full play to the advantages of various machine tools, and inserting reasonable heat treatment and auxiliary processes to make its processing flow more reasonable and the operation method simpler. The shift control valve processed by the processing method described in the present invention has a workpiece qualification rate of 100%. The processing time is shortened by 23% compared with the original method, and the processing cost is reduced by 12%. The wear resistance and accuracy of the shift control valve are improved, thereby improving the stability and service life of the shift controller assembly. BRIEF DESCRIPTION OF THE DRAWINGS

[0039] In order to more clearly illustrate the technical solutions in the specific embodiments of the present invention, the following will briefly introduce the drawings required for the description of the embodiments. Obviously, the drawings described below are only some embodiments of the present invention. For those of ordinary skill in the art, other drawings can be obtained based on these drawings without creative efforts.

[0040] Figure 1 This is a schematic diagram of the finished product structure of the shift control valve in the present invention;

[0041] Figure 2 This is a schematic diagram of the structure of part B of the finished product of the shift control valve in the present invention;

[0042] Figure 3 This is a schematic diagram of the structure of part C of the finished product of the shift control valve in the present invention;

[0043] Figure 4 This is a schematic diagram of the structure of part D of the finished product of the shift control valve in the present invention;

[0044] Figure 5 This is a schematic diagram of the turning process in step 3 of the present invention;

[0045] Figure 6 This is a schematic diagram of the turning process in step 4 of the present invention;

[0046] Figure 7 This is a schematic diagram of the turning process in step 5 of the present invention;

[0047] Figure 8 This is a schematic diagram of the turning process in step 6 of the present invention;

[0048] Figure 9 This is a schematic diagram of the boring process in step 7 of the present invention;

[0049] Figure 10 This is a schematic diagram of the drilling process in step 8 of the present invention;

[0050] Figure 11 This is a schematic diagram of the boring process in step 9 of the present invention;

[0051] Figure 12 And this is a schematic diagram of the milling process in step 10 of the present invention;

[0052] Figure 13 This is Figure 12 a partial structure diagram at position C of;

[0053] Figure 14 This is a schematic diagram of the milling process in step 11 of the present invention;

[0054] Figure 15 This is Figure 14 a partial structure diagram at position D of;

[0055] Figure 16 This is a schematic diagram of the benchwork processes in steps 14 and 19 of the present invention;

[0056] Figure 17 This is Figure 16 a partial structure diagram at position E of;

[0057] Figure 18 It is a schematic diagram of the grinding process in step 16 of the present invention;

[0058] Figure 19 It is a schematic diagram of the grinding process in step 20 of the present invention;

[0059] In the figure, B4 / 12.5 - center hole; 71 - double - opening bushing; 121 - double - opening clamping sleeve; 122 - axial positioning plate; 123 - positioning pin; 141 - double - opening clamping sleeve; 142 - axial positioning plate; 143 - positioning pin; 161 - single - opening clamping sleeve; 181 - special internal center - point; 182 - standard center - point. Detailed implementation manners

[0060] The present invention will be further described below in conjunction with the accompanying drawings and specific embodiments. However, it should not be understood that the scope of the subject matter of the present invention is limited to the following embodiments. Without departing from the above - mentioned technical idea of the present invention, all modifications, substitutions, and changes made according to ordinary technical knowledge and customary means in the art are included in the scope of the present invention.

[0061] Step 1: Blanking. The material is 38CrMoAl - GB / T3077. The blanking size is round bar φ53mm×566mm, and one piece is made from each blank.

[0062] Step 2: Heat treatment, normalizing.

[0063] Step 3: Turning. It is processed on an ordinary lathe. See the attached Figure 5 ,

[0064] (1) Clamp the outer diameter of the blank, turn the end face, and drill the center hole B4 / 12.5.

[0065] (2) Clamp the outer diameter of the blank, use the center - point to support the center hole, and turn the outer diameter, the outer diameter is φ49mm.

[0066] (3) Clamp the turned outer diameter, turn the end face, control the total length to 562.5mm, drill the center hole B4 / 12.5, and turn the outer diameter φ33mm by using the center - point.

[0067] (4) Leave a machining allowance of 1mm - 1.5mm on the outer diameter.

[0068] Step 4: CNC lathe machining. See the attached Figure 6 , clamp the outer diameter of the small end, use the center - point to support the center hole, and perform one - time clamping to turn the outer diameter, annular groove, and profile R. Leave a machining allowance of 0.35mm - 0.5mm (tolerance h10) on the large outer diameter.

[0069] Step 5: CNC lathe machining. See the attached Figure 7, Position with the side surface of the annular groove of the workpiece, use the double-opening bushing 71 to position the axial position, and use the center drill to press the center hole. Machine the outer circle and the tool withdrawal groove in one loading. Leave a margin of 0.35 mm to 0.5 mm (tolerance h10) on the outer circle, and machine the rest to the requirements of the design drawing. The double-opening bushing belongs to a two-piece split bushing. The inner hole of the bushing fits with the outer circle of the workpiece, which is 0.06 mm to 0.12 mm larger than the outer circle of the workpiece. One end of the bushing has an inner step and an outer step. The inner step is inserted into the annular groove of the workpiece for side positioning, and the side of the outer step abuts against the end face of the three-jaw of the machine tool for axial positioning;

[0070] Step 6: Machining on a common lathe. The machining process drawing is shown in the appendix Figure 8 , Position with the side surface of the annular groove of the workpiece, use the double-opening bushing 71 to position the axial position, turn the end face, and control the length dimension of 9 mm;

[0071] Step 7: Machining on a vertical machining center. The machining process drawing is shown in the appendix Figure 9 , Clamp the workpiece with a dividing head, align the outer circle, drill a positioning hole with a center drill, drill, ream, and bore the hole, chamfer, rotate the dividing head, and chamfer;

[0072] Step 13: Machining on a horizontal boring machine. The machining process drawing is shown in the appendix Figure 10 , Clamp the workpiece with two identical "V-blocks", align the outer circle of the workpiece, drill a positioning hole with a center drill, first drill with a short drill bit, and then drill with an extended drill bit. The drill bit speed is 320 r / min to 360 r / min. Retract the tool every 3 mm to 5 mm of drilling, feed manually and evenly, and cool;

[0073] Step 18: Machining on a vertical machining center. The machining process drawing is shown in the appendix Figure 11 , Align the outer circle and the hole, bore two plug holes, and chamfer;

[0074] Step 23: Machining on a horizontal milling machine. The machining process drawing is shown in the appendix Figure 12 , Appendix Figure 13 , Clamp the workpiece with a milling fixture, mill a straight groove, and then remove the burrs after milling by benchwork;

[0075] Step 30: Milling machining, machining on a horizontal milling machine. The machining process drawing is shown in the appendix Figure 14 , Appendix Figure 15 , Clamp the workpiece with a milling fixture, mill an R groove, and then remove the burrs after milling by benchwork;

[0076] In the said Steps 10 and 11, milling operations are carried out using a straight-groove milling fixture and an R-groove milling fixture. These two milling fixtures mainly consist of double-opening clamping sleeves 121 and 141, axial positioning plates 122 and 142, and positioning pins 123 and 143. The inner holes of the double-opening clamping sleeves 121 and 141 are matched with the outer diameter of the workpiece, being 0.06 mm to 0.12 mm larger than the outer diameter of the workpiece. The double-opening clamping sleeve 121 of the straight-groove milling fixture is machined into a straight groove, and the double-opening clamping sleeve 141 of the R-groove milling fixture is machined into an R groove. The axial positioning plates 122 and 142 are fixed to one end of a clamping sleeve using cylindrical pins and bolts to position the axial position of the workpiece. The positioning pins 123 and 143 are installed on the axial positioning plates 122 and 142. One end of the positioning pins 123 (143) is in interference fit with the holes of the axial positioning plates 122 and 142, and the other end is in clearance fit with the plug holes of the workpiece, with a clearance of 0.08 mm to 0.15 mm, restricting the angular position of the workpiece;

[0077] Step 12: Heat treatment to eliminate stress;

[0078] Step 13: Straightening. Check that the runout between the R surface of the profile and the large outer diameter of the workpiece is not greater than 0.07 mm, and straighten the workpiece using a straightening machine;

[0079] Step 14: Benchwork. The machining process diagram is shown in Attachment Figure 16 、Attachment Figure 17 ., Pour low-melting-point alloy, dry the single-opening clamping sleeve 161 and the workpiece, clamp the outer diameter of the workpiece with the single-opening clamping sleeve 161, and pour low-melting-point alloy from one hole of the workpiece until the holes and grooves of the workpiece are filled with low-melting-point alloy;

[0080] Step 15: Turning: Machining on an ordinary lathe. The machining process diagram is shown in Attachment Figure 18 ,

[0081] (1) Calibrate the large outer diameter, with a runout not greater than 0.05 mm, turn the large-end outer cone surface at 60°, and the surface roughness Ra is 1.6;

[0082] (2) Calibrate the large outer diameter, with a runout not greater than 0.05 mm, turn the inner cone surface of the small-end center hole at 60°, and the surface roughness Ra is 1.6;

[0083] Step 16: Machining on an external grinding machine. The machining process diagram is shown in the appendix of the specification Figure 18 ,

[0084] (1) Mount the workpiece with a special internal center 181 at one end and a standard center 182 at the other end, and grind the large outer diameter;

[0085] (2) Mount the workpiece with a special internal center 181 at one end and a standard center 182 at the other end, and grind the small outer diameter;

[0086] (3) Leave a machining allowance of 0.09 mm to 0.15 mm on the outer circle, and the coaxiality between the outer circle and the 60° tapered surfaces at both ends is 0.04 mm to 0.07 mm;

[0087] Step 17: Benchwork. Hang the workpiece in the oil tank, heat it to 140°C to 150°C to melt the low-melting-point alloy, and remove the burrs after grinding by benchwork;

[0088] Step 18: Heat treatment: Nitriding treatment, nitriding depth of 0.18 mm to 0.3 mm, surface hardness HV > 700;

[0089] Step 19: Benchwork, with the requirements and methods the same as those in Step 14;

[0090] Step 20: Grinding: Machining on a precision cylindrical grinder. See the attached Figure 19 ,

[0091] (1) Mount the workpiece at one end with a special internal center 181 and at the other end with a standard center 182, and grind the large outer circle to the required size;

[0092] (2) Mount the workpiece at one end with a special internal center 181 and at the other end with a standard center 182, and grind the small outer circle to the required size;

[0093] Step 21: Benchwork, with the requirements and methods the same as those in Step 17;

[0094] Step 22: Cleaning, rust prevention, and packaging.

[0095] The above has introduced in detail a processing method of a pressure control valve provided by the present invention. Specific examples are used in this article to elaborate on the structure and working principle of the present invention. The description of the above embodiments is only used to help understand the method and core idea of the present invention. It should be noted that for those of ordinary skill in the art in this technical field, without departing from the principle of the present invention, several improvements and modifications can still be made to the present invention, and these improvements and modifications also fall within the scope of protection of the claims of the present invention.

Claims

1. A processing method for a shift control valve, characterized in that: It includes the following steps: Step 1: Cut the material with machining allowance according to the outer diameter and length of the workpiece. Step 2: Heat treatment, normalizing. Step 3: Turning, turning the end face, drilling the center hole, rough turning the large outer diameter and small outer diameter, leaving allowance on the outer diameter. Step 4: Turning, clamping the small outer diameter, supporting the center hole, turning the outer diameter, annular groove, and profile R, leaving allowance on the large outer diameter, and machining the rest to the requirements. Step 5: Turning, positioning the workpiece with a double-opening bushing, clamping the bushing, supporting the center hole, turning the outer diameter and the relief groove, leaving allowance on the outer diameter, and machining the rest to the requirements. Step 6: Turning, positioning the workpiece with a double-opening bushing, clamping the bushing, turning the end face, and controlling the length dimension. Step 7: Boring, aligning the outer diameter, drilling and boring the end hole of the shaft, and chamfering. Step 8: Drilling, aligning the outer diameter, and drilling two deep holes. Step 9: Boring, aligning the outer diameter and the hole, boring the plug holes at the two deep holes, and chamfering. Step 10: Milling and filing, clamping the workpiece with a milling fixture, milling the straight groove, and removing burrs by filing. Step 11: Milling and filing: Clamping the workpiece with a milling fixture, milling the R groove, and removing burrs by filing. Step 12: Heat treatment, stress relieving. Step 13: Straightening the workpiece. Step 14: Filing, casting low-melting-point alloy into the holes and grooves of the workpiece. Step 15: Turning, calibrating the outer diameter, and turning the cone for the center drill. Step 16: Grinding, mounting the workpiece with a special internal center drill and a standard center drill, grinding the two outer diameters, and leaving allowance. Step 17: Filing, removing burrs after melting the low-melting-point alloy. Step 18: Heat treatment, nitriding treatment. Step 19: Filing, casting low-melting-point alloy into the holes and grooves of the workpiece. Step 20: Grinding, mounting the workpiece with a special center drill and a standard center drill, precisely grinding the two outer diameters to the requirements of the design drawing. Step 21: Filing: Removing burrs after melting the low-melting-point alloy. Step 22: Warehousing.

2. The processing method of the shift control valve according to claim 1, characterized in that: In the said Step 1, the length dimension includes the length of the process block.

3. The processing method of the shift control valve according to claim 1, characterized in that: The allowance left on the outer diameter in Step 3 is 1 mm to 1.5 mm, and the allowances left on the outer diameters in Steps 4 and 5 are both 0.35 mm to 0.5 mm.

4. The processing method of the shift control valve according to claim 1, characterized in that: The double-opening bushing turned in Step 5 is a two-piece opening bushing. The inner hole of the bushing fits with the outer diameter of the workpiece, being 0.06 mm to 0.12 mm larger than the outer diameter of the workpiece. One end of the bushing has an inner step and an outer step. The inner step is inserted into the annular groove of the workpiece for lateral positioning, and the side of the outer step abuts against the end face of the three-jaw chuck of the machine tool for axial positioning.

5. The processing method of the shift control valve according to claim 1, characterized in that: In the milling in Steps 10 and 11, the workpiece is clamped with a milling fixture, and then the milling fixture is clamped with a vise, aligning the milling cutter, and milling the straight groove and the R groove. The milling fixtures are respectively a straight groove milling fixture and an R groove milling fixture. The two milling fixtures are mainly composed of a double-opening clamping sleeve, an axial positioning plate and a positioning pin. The inner hole of the double-opening clamping sleeve is matched with the outer circle of the workpiece, and is 0.06 mm to 0.12 mm larger than the outer circle of the workpiece. The double-opening clamping sleeve of the straight groove milling fixture is machined into a straight groove, and the double-opening clamping sleeve of the R groove milling fixture is machined into an R groove. The axial positioning plate is fixed at one end of a clamping sleeve with a cylindrical pin and a bolt to position the axial position of the workpiece. The positioning pin is installed on the axial positioning plate. One end of the positioning pin is in interference fit with the hole of the axial positioning plate, and the other end is in clearance fit with the plug hole of the workpiece to limit the angular position of the workpiece.

6. The processing method of the shift control valve according to claim 1, characterized in that: In step 13, the workpiece is straightened by a straightening machine, and the runout between the profiled surface R surface and the large outer circle of the workpiece is checked to be no more than 0.07 mm.

7. The processing method of the shift control valve according to claim 1, characterized in that: In steps 14 and 19, low-melting-point alloy is poured, the single-opening clamping sleeve and the workpiece are dried, the outer circle of the workpiece is clamped with the single-opening clamping sleeve, and the low-melting-point alloy is poured from a hole of the workpiece until the holes and grooves of the workpiece are filled with the low-melting-point alloy.

8. The processing method of the shift control valve according to claim 1, wherein: In step 15, the large outer circle is calibrated, and the runout is no more than 0.05 mm. The outer cone surface at the large end is turned at 60°, and the inner cone surface of the center hole at the small end is turned at 60°.

9. The processing method of the shift control valve according to claim 1, characterized in that: In step 16, for grinding, the workpiece is mounted with a special inner center at one end and a standard center at the other end, and the two outer circles are ground respectively. A margin of 0.09 mm to 0.15 mm is left on the outer circles, and the coaxiality between the outer circles and the 60° cone surfaces at both ends is 0.04 mm to 0.07 mm.

10. The processing method of the shift control valve according to claim 1, characterized in that: Step 17 is to hang the workpiece in an oil tank and heat it to 140 °C to 150 °C to melt the low-melting-point alloy.

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