Oil distribution shaft and machining method

Abstract

The invention discloses an oil distribution shaft and a machining method, belongs to the technical field of oil distribution shaft machining, and solves the problems that the machining precision of an outer circle of a bearing mounting position and an outer circle of a sealing position of an existing oil distribution shaft cannot meet the use requirement, and the detection qualification rate is low. The method comprises the following steps: firstly, carrying out appearance turning on the oil distribution shaft, then, carrying out vacuum heat treatment on the oil distribution shaft, then, processing center holes in two ends at one time, then, carrying out coarse grinding on the oil distribution shaft, carrying out fine grinding after the coarse grinding is completed, carrying out primary polishing on the excircle of the oil distribution shaft after the grinding is completed, carrying out QPQ heat treatment after the polishing is completed, and then, cleaning salt slag left by the QPQ heat treatment. Performing ultrasonic cleaning, and performing primary polishing on the outer circle after cleaning is completed; according to the oil distribution shaft and the machining method, high-precision and high-efficiency machining of the oil distribution shaft can be achieved through conventional equipment.

Description

Technical Field

[0001] The invention relates to the technical field of oil distribution shaft processing, and more specifically, to an oil distribution shaft and a processing method thereof. Background Art

[0002] like Figure 1 As shown, this oil distribution shaft 1 has higher requirements than the usual oil distribution shaft 1, mainly because the rotary joint composed of this oil distribution shaft 1 is installed in the drum of the combine harvester. According to technical requirements, its maximum working speed is 1500r / min, the maximum pressure requirement is 21Mpa, and the working time is required to be 12 hours a day; therefore, the roughness, roundness and dimensional accuracy requirements of the outer circle of this oil distribution shaft 1 are of paramount importance and must be precisely controlled.

[0003] The existing processing procedures are as follows: pick up materials → turn the end face, outer circle, cut off → turn the total length, drill the center hole → turn the end face, rough and fine turn the outer circle → rough grind the φ10 outer circle → turn the total length, turn M12 thread → mill hexagon → remove burrs → semi-finishing grinding → fine grinding → QPQ heat treatment → drill φ4 hole → turn and drill φ2 hole → remove burrs → polish the outer circle; a total of 15 processes, which require frequent turning and secondary clamping, which is easy to clamp the workpiece surface or lengthen the process, thereby causing flow damage between processes, and the outer circle surface may be clamped or bruised. This affects the oil distribution shaft because the outer circle is not round during grinding, resulting in batch scrapping. In addition, in the existing processing methods, the roughness of the outer circle sealing surface of the oil distribution shaft is difficult to meet the requirements, and the yield rate is low. This is mainly because the center holes at both ends are misaligned and not round, and slight chatter marks are easily produced after processing, which makes it impossible to ensure that the roughness is qualified. When processing the outer circle bearing position of the oil distribution shaft, due to the poor roughness of the center hole, the workpiece does not rotate smoothly, resulting in an elliptical outer circle bearing position of the oil distribution shaft, which is more likely to wear the grinding machine top, which will cause the top to be scrapped over time. The top wear period also affects the quality of each product. Summary of the invention

[0004] The technical problem to be solved by the present invention is to address the above-mentioned deficiencies in the prior art. The purpose of the present invention is to provide an oil distribution shaft and a processing method, which can realize high-precision and high-efficiency processing of the oil distribution shaft using conventional equipment.

[0005] In order to achieve the above-mentioned purpose, the present invention provides a processing method for an oil distribution shaft, which method comprises the following steps: firstly machining the oil distribution shaft, then subjecting it to vacuum heat treatment, and processing the center holes at both ends at one time, and then rough grinding the oil distribution shaft, and then fine grinding it after the rough grinding is completed. After grinding, the outer circle thereof is first polished, and after polishing, QPQ heat treatment is performed, and then the salt residue left by the QPQ heat treatment is cleaned, and ultrasonic cleaning is performed, and after cleaning, the outer circle thereof is first polished.

[0006] As a further improvement, the following specific steps are included:

[0007] S1: Carry out the shape of the oil distribution shaft according to the design drawings, and keep the margin between 0.25mm and 0.3mm;

[0008] S2: Perform vacuum heat treatment on the oil distribution shaft, with the temperature set between 40 and 80°C;

[0009] S3: The center holes at both ends are processed by Swiss lathe. The center holes at both ends are processed at one time to improve the coaxiality of the center holes at both ends.

[0010] S4: Roughly grind the bearing mounting shaft and the sealing shaft of the oil distribution shaft using an external cylindrical grinder, and then fine grind after the rough grinding is completed;

[0011] S5: Use a polishing machine to perform the first polishing on the bearing mounting shaft and the sealing shaft of the oil distribution shaft. After polishing, use a salt bath nitriding furnace to perform QPQ heat treatment on the oil distribution shaft for 1.5 hours;

[0012] S6: Clean the salt residue in the inner hole and use an ultrasonic cleaner to clean it. After cleaning, use a polishing machine to polish the oil distribution shaft for the second time.

[0013] Furthermore, in the step 3, when processing the center hole, the rotation speed is set to 1300r / min and the feed rate is 0.03mm / r.

[0014] Furthermore, in the step 4, the grinding wheel of the grinder adopts an SG small-pore grinding wheel. During rough grinding, the grinding wheel mesh number is 120 mesh, the rotation speed is 150r / min, and the feed rate is 200mm / min. During fine grinding, the grinding wheel mesh number is 200 mesh and the grinding wheel width is 40mm.

[0015] Furthermore, in the step S4: a semi-finishing grinding process is added before fine grinding, and the remaining grinding amount should be between 0.015 and 0.03 mm.

[0016] Furthermore, in the step S5: a CNC lathe is used for rotational polishing at a speed of more than 1500 r / min, and the outer circle of the sealing shaft is firstly roughly polished with 1500-mesh sandpaper, and then finely polished with 2000-mesh sandpaper.

[0017] Furthermore, in the step S6: after the QPQ heat treatment, the outer circle is polished using the previous method and 2000 mesh diamond paper is used for polishing.

[0018] An oil distribution shaft, the oil distribution shaft manufactured according to the processing method, comprises a bearing installation shaft, one end of the bearing installation shaft is provided with a rotating hexagonal nut, the end of the rotating hexagonal nut away from the bearing installation shaft is provided with a connecting shaft, the connecting shaft is provided with an external thread for connecting with an adapter, the other end of the bearing installation shaft is provided with a sealing shaft, the middle of the bearing installation shaft and the sealing shaft are provided with a communicating oil through hole, and the bearing installation shaft is provided with a card slot.

[0019] Furthermore, the outer circle roughness of the bearing mounting shaft is Ra1.4-Ra1.6, and the outer circle roughness of the sealing shaft is Ra0.01-Ra0.05.

[0020] Furthermore, an O-ring installation groove for sealing is provided on the connecting shaft.

[0021] Beneficial Effects

[0022] Compared with the prior art, the present invention has the following advantages:

[0023] 1. The processing method of the oil distribution shaft of the present invention processes the center holes at both ends in one process, which solves the problem of the center holes at both ends being out of axial alignment and misalignment. The processing parameters are modified to control the roughness of the center holes at both ends so that the runout and roundness are guaranteed during the grinding process. The processed ellipse can be controlled within 0.002 mm.

[0024] 2. The processing method of the oil distribution shaft of the present invention is to change the original green silicon carbide grinding wheel into an SG small-pore grinding wheel, the grinding wheel mesh number is changed from the original 100 mesh to 120 mesh, and the grinding wheel width is changed from the original 63mm to 40mm. The contact force area is small, and it is easy to grind and reduce the ellipse. According to the improved dimensional accuracy, it can meet the process requirements and ensure the dimensional processing accuracy and roundness.

[0025] 3. Add a semi-finishing grinding process between rough grinding and fine grinding. The semi-finishing grinding allowance should be between 0.015 and 0.03 mm. Too much allowance will cause fine grinding to easily wear and the dimensional accuracy will not be met. This method effectively ensures the processing accuracy. BRIEF DESCRIPTION OF THE DRAWINGS

[0026] Figure 1 is a flow chart of the present invention;

[0027] Figure 2 It is a schematic diagram of the cross-sectional structure of the oil distribution shaft in the present invention;

[0028] Figure 3 It is a schematic diagram of the cross-sectional structure of the oil distribution shaft in the present invention in practical application.

[0029] Among them: 1-oil distribution shaft, 2-rotating hexagonal nut, 3-connecting shaft, 4-external thread, 5-sealing shaft, 6-slot, 7-O-ring installation groove, 8-bearing installation shaft, 9-oil hole, 10-sealing gasket, 11-Y-ring, 12-sealing retaining ring, 13-bearing retaining ring, 14-deep groove ball bearing, 15-rotating body, 16-adapter. DETAILED DESCRIPTION

[0030] The present invention will be further described below with reference to the specific embodiments in the accompanying drawings.

[0031] See also Figure 1-3 , which is a processing method for an oil distribution shaft of the present invention. The method is to firstly machine the oil distribution shaft, then perform vacuum heat treatment on it, and then process the center holes at both ends at one time, and then perform rough grinding on the oil distribution shaft, and then perform fine grinding after the rough grinding, and then perform the first polishing on its outer circle after grinding, and then perform QPQ heat treatment after polishing, and then clean the salt residue left by the QPQ heat treatment, perform ultrasonic cleaning, and after cleaning, perform the first polishing on its outer circle.

[0032] In this embodiment, there are a total of 10 processes, which is 5 processes less than the previous process, and it is not necessary to clamp the outer circle in the subsequent process processing, which greatly reduces the risk of clamping damage and process flow damage. The center holes at both ends are processed in one process, which solves the problem of different axes and misalignment of the center holes at both ends. The processing parameters are modified to control the roughness of the center holes at both ends, so that the runout and roundness are guaranteed during the grinding machine processing. The processed size ellipse can be controlled within 0.002mm. The original green silicon carbide grinding wheel is changed to SG small pore grinding wheel, the grinding wheel mesh number is changed from the original 100 mesh to 120 mesh, and the grinding wheel width is changed from the original 63mm to 40mm. The contact force area is small, and it is easy to grind and reduce the ellipse. According to the improvement of dimensional accuracy, it can meet the process requirements and ensure the processing accuracy and roundness of the size. A semi-fine grinding process is added between rough grinding and fine grinding to hinder the quality of subsequent fine grinding. The roughness and dimensional accuracy of the oil distribution shaft produced by this processing method are guaranteed, the yield rate is also improved, and the use requirements are met.

[0033] Furthermore, the method comprises the following specific steps:

[0034] S1: Carry out the shape of the oil distribution shaft according to the design drawings, and keep the margin between 0.25mm and 0.3mm;

[0035] S2: Perform vacuum heat treatment on the oil distribution shaft, with the temperature set between 40 and 80°C;

[0036] S3: The center holes at both ends are processed by Swiss lathe. The center holes at both ends are processed at one time to improve the coaxiality of the center holes at both ends.

[0037] S4: Roughly grind the bearing mounting shaft 8 and the sealing shaft 5 of the oil distribution shaft using an external cylindrical grinder, and then finely grind after the rough grinding is completed;

[0038] S5: The bearing mounting shaft 8 and the sealing shaft 5 of the oil distribution shaft are polished for the first time by using a polishing machine. After polishing, the oil distribution shaft is subjected to QPQ heat treatment for 1.5 hours by using a salt bath nitriding furnace;

[0039] S6: Clean the salt residue in the inner hole and use an ultrasonic cleaner to clean it. After cleaning, use a polishing machine to polish the oil distribution shaft for the second time.

[0040] Furthermore, in step 3, when processing the center hole, the rotation speed is set to 1300 r / min and the feed rate is 0.03 mm / r.

[0041] In this embodiment, in the vehicle shape, the machining allowance should be within 0.25mm~0.3mm. If it is too much, it is easy to wear and affect the roughness quality, and if it is too little, it is easy to not finish the flower. When machining the center hole, in order to achieve the center hole roughness, the machining parameters are changed accordingly. The speed is changed from the original 800r / min to 1300r / min, and the feed is changed from the original 0.1mm / r to 0.03mm / r. The center holes at both ends are machined at one time by a Swiss machine. The center holes at both ends are machined at one time to improve the coaxiality of the center holes at both ends, which can reduce the slight jump in the external cylindrical grinding process and effectively control the coaxiality of the center holes at both ends within 0.01

[0042] Furthermore, in step 4, the grinding wheel of the grinder adopts SG small-pore grinding wheel, the grinding wheel mesh number is 120 mesh, the rotation speed is 150r / min, the feed rate is 200mm / min during rough grinding, and the grinding wheel mesh number is 200 mesh and the grinding wheel width is 40mm during fine grinding.

[0043] In this embodiment, the oil distribution shaft is made of 38CrMoAl alloy, and the SG small-pore grinding wheel is more suitable for grinding alloy structural steels such as 38CrMoAl. The mesh number of the grinding wheel is changed from 100 mesh to 120 mesh during rough grinding, and the mesh number of the grinding wheel is changed from 150 mesh to 200 mesh during fine grinding. In addition, the processing parameters are improved, the workpiece speed is changed from 190r / min to 150r / min, and the feed is changed from the original 240mm / min to 200mm / min. The grinding process is more stable and the roughness of the ground product is lower.

[0044] Furthermore, in step S4: a semi-fine grinding process is added before fine grinding, and the remaining grinding amount should be between 0.015 and 0.03 mm. Too coarse roughness and too little remaining amount will lead to insufficient fine grinding, while too much remaining amount will lead to easy wear during fine grinding and inconsistent roughness. A semi-fine grinding process may ensure the quality of subsequent fine grinding.

[0045] Further, in step S5: a CNC lathe is used for rotational polishing, and the rotation speed is required to be above 1500 r / min. The outer circle of the sealing shaft 5 is firstly roughly polished with 1500-mesh sandpaper, and then the outer circle of the sealing shaft 5 is finely polished with 2000-mesh sandpaper.

[0046] In this embodiment, after the fine grinding process, an outer cylindrical polishing process is added before the QPQ heat treatment process, and the number of polishing times is increased to meet the production accuracy requirements.

[0047] Further, in step S6: after the QPQ heat treatment is completed, the outer circle is polished using the previous method, and 2000 mesh diamond paper is used for polishing. Before the QPQ heat treatment, vacuum heat treatment is performed. The hardness of the material is adjusted by vacuum heat treatment. After the hardness is high, the roughness of the product processed by the grinder can be optimized. After the vacuum heat treatment, the original QPQ heat treatment time is reduced. It was originally heated in a salt bath nitriding furnace for 3.5 hours, but now it is shortened to 1.5 hours. The 1.5-hour salt bath nitriding furnace heating reduces its time, ensuring that the workpiece does not need to be heated in the furnace for a long time, resulting in a decrease in the tempering hardness. It can not only ensure the hardness, but also meet the salt spray test required by customers.

[0048] An oil distribution shaft, an oil distribution shaft manufactured according to the above-mentioned processing method, includes a bearing installation shaft 8, a rotating hexagonal nut 2 is provided at one end of the bearing installation shaft 8, a connecting shaft 3 is provided at one end of the rotating hexagonal nut 2 away from the bearing installation shaft 8, an external thread 4 for connecting to an adapter 16 is provided on the connecting shaft 3, a sealing shaft 5 is provided at the other end of the bearing installation shaft 8, a communicating oil through hole 9 is provided between the bearing installation shaft 8 and the sealing shaft 5, and a card slot 6 is provided on the bearing installation shaft 8.

[0049] In this embodiment, the bearing mounting shaft 8 is rotatably mounted in the rotating body 15 through a deep groove ball bearing 14, and is limited by a bearing retaining ring 13. It is connected to the adapter 16 through the external thread 4 of the connecting shaft 3, and is sealed by installing an O-ring on the O-ring mounting groove 7. The front end of the oil distribution shaft 1 is sealed by a sealing gasket 10, a Y-ring 11, and a sealing retaining ring 12 to prevent the hydraulic oil from leaking from the rotating part. The hydraulic oil flows in from the oil through hole 9 and circulates through the adapter 16. The oil distribution shaft of this solution has high precision and can meet the use requirements of different environments.

[0050] Furthermore, the outer circle roughness of the bearing mounting shaft 8 is Ra1.4-Ra1.6, and the outer circle roughness of the sealing shaft 5 is Ra0.01-Ra0.05. The reduction in roughness effectively increases the range of the oil distribution shaft and can be applied to high-precision equipment for efficient, long-term and stable operation.

[0051] Furthermore, an O-ring installation groove 7 for sealing is provided on the connecting shaft 3, and an O-ring is installed on the O-ring installation groove 7 for sealing, so as to seal the sealing adapter 16 and prevent the hydraulic oil from leaking therefrom.

[0052] The above are only preferred embodiments of the present invention. It should be pointed out that for those skilled in the art, several modifications and improvements can be made without departing from the structure of the present invention, which will not affect the effect of the implementation of the present invention and the practicality of the patent.

Claims

1. A method for processing an oil distribution shaft, characterized in that: The method comprises the following steps: firstly machining the oil distribution shaft, then subjecting it to vacuum heat treatment, and processing the center holes at both ends at one time, and then rough grinding the oil distribution shaft, and then fine grinding the shaft. After the rough grinding, the outer circle is polished for the first time, and then QPQ heat treatment is performed after the polishing is completed. Then, the salt residue left by the QPQ heat treatment is cleaned, and ultrasonic cleaning is performed. After the cleaning is completed, the outer circle is polished for the first time.

2. The method for processing an oil distribution shaft according to claim 1, characterized in that: The specific steps include: S1: Carry out the shape of the oil distribution shaft according to the design drawings, and keep the margin between 0.25mm and 0.3mm; S2: Perform vacuum heat treatment on the oil distribution shaft, with the temperature set between 40 and 80°C; S3: The center holes at both ends are processed by Swiss lathe. The center holes at both ends are processed at one time to improve the coaxiality of the center holes at both ends. S4: using an external cylindrical grinder to perform rough grinding on the bearing mounting shaft (8) and the sealing shaft (5) of the oil distribution shaft, and then performing fine grinding after the rough grinding is completed; S5: using a polishing machine to perform a first polishing on the bearing mounting shaft (8) and the sealing shaft (5) of the oil distribution shaft. After polishing, the oil distribution shaft is subjected to a QPQ heat treatment for 1.5 hours in a salt bath nitriding furnace; S6: Clean the salt residue in the inner hole and use an ultrasonic cleaner to clean it. After cleaning, use a polishing machine to polish the oil distribution shaft for the second time.

3. The method for processing an oil distribution shaft according to claim 2, characterized in that: In the step 3, when processing the center hole, the rotation speed is set to 1300r / min and the feed rate is 0.03mm / r.

4. The method for processing an oil distribution shaft according to claim 3, characterized in that: In the step 4, the grinding wheel of the grinder adopts SG small-pore grinding wheel, the grinding wheel mesh number is 120 meshes, the rotation speed is 150r / min, the feed rate is 200mm / min, and the grinding wheel mesh number is 200 meshes and the grinding wheel width is 40mm during rough grinding.

5. The method for processing an oil distribution shaft according to claim 4, characterized in that: In the step S4: a semi-fine grinding process is added before fine grinding, and the remaining grinding amount should be between 0.015 and 0.03 mm.

6. The method for processing an oil distribution shaft according to claim 2, characterized in that: In the step S5, a CNC lathe is used for rotary polishing at a speed of more than 1500 r / min, and the outer circle of the sealing shaft (5) is firstly roughly polished with 1500-mesh sandpaper, and then the outer circle of the sealing shaft (5) is finely polished with 2000-mesh sandpaper.

7. The method for processing an oil distribution shaft according to claim 2, characterized in that: In the step S6: after the QPQ heat treatment is completed, the outer circle is polished using the previous method, and 2000 mesh diamond paper is used for polishing.

8. An oil distribution shaft, characterized in that: The oil distribution shaft manufactured according to the processing method described in claims 1-7 comprises a bearing installation shaft (8), one end of the bearing installation shaft (8) is provided with a rotating hexagonal nut (2), the end of the rotating hexagonal nut (2) away from the bearing installation shaft (8) is provided with a connecting shaft (3), the connecting shaft (3) is provided with an external thread (4) for connecting to an adapter (16), the other end of the bearing installation shaft (8) is provided with a sealing shaft (5), the middle of the bearing installation shaft (8) and the sealing shaft (5) are provided with a communicating oil through hole (9), and the bearing installation shaft (8) is provided with a slot (6).

9. The oil distribution shaft according to claim 8, characterized in that: The outer circle roughness of the bearing installation shaft (8) is Ra1.4-Ra1.6, and the outer circle roughness of the sealing shaft (5) is Ra0.01-Ra0.

05.

10. The oil distribution shaft according to claim 9, characterized in that: The connecting shaft (3) is provided with an O-ring mounting groove (7) for sealing.

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