Oil distribution shaft and method of machining

Abstract

The application discloses a kind of oil distribution shaft and processing method, belong to oil distribution shaft processing technical field, solve the bearing mounting position outer circle and sealing position outer circle machining precision of existing oil distribution shaft cannot reach use demand, and the problem of low detection qualified rate.The method is first to the oil distribution shaft is profiled, then it is vacuum heat treated, machining the center hole of two ends again, then the oil distribution shaft is coarsely ground, after coarsely grinding, it is finely ground, after grinding, its outer circle is polished first time, after polishing, then QPQ heat treatment is carried out, then the salt residue left by QPQ heat treatment is cleaned, ultrasonic cleaning is carried out, after cleaning, its outer circle is polished first time.The oil distribution shaft and processing method of the application can realize high-precision, high-efficiency processing oil distribution shaft by using conventional equipment.

Description

Technical Field

[0001] The present invention relates to the technical field of oil distribution shaft processing, and more particularly 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 reaches 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: material collection → turning the end face and outer circle, cutting → turning the total length, drilling the center hole → turning the end face, rough and fine turning the outer circle → rough grinding the φ10 outer circle → turning the total length, turning M12 threads → milling hexagons → deburring → semi-finishing grinding → fine grinding → QPQ heat treatment → drilling φ4 holes → turning and drilling φ2 holes → deburring → polishing the outer circle; a total of 15 processes, requiring frequent turning and secondary clamping, which can easily damage the workpiece surface or lengthen the process, thereby causing flow damage between processes, and the outer circle surface may be pinched or bruised. This affects the outer circle of the oil distribution shaft 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 meets the requirements. 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. Over time, the top will be scrapped, and the top wear period will also affect 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 object, the present invention provides a method for processing an oil distribution shaft, wherein the method comprises first turning the oil distribution shaft into an outer shape, then subjecting the shaft to vacuum heat treatment, and then processing the center holes at both ends at once, followed by rough grinding of the oil distribution shaft, and then fine grinding, and then polishing the outer circle of the shaft for the first time after grinding, and then performing QPQ heat treatment after polishing, and then cleaning the salt residue left by the QPQ heat treatment, and then performing ultrasonic cleaning, and then polishing the outer circle of the shaft for the second time after cleaning.

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

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

[0008] S2: Vacuum heat treatment of the oil distribution shaft;

[0009] S3: The center holes at both ends are processed by Swiss lathe, and 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 cleaning machine to clean it. After cleaning, use a polishing machine to polish the oil distribution shaft for the second time.

[0013] Furthermore, in the step S3, when processing the center hole, the rotation speed is set to 1300 r / min and the feed rate is 0.03 mm / r.

[0014] Furthermore, in the step S4, the grinding wheel of the grinder adopts an SG small-pore grinding wheel. During rough grinding, the grinding wheel mesh number is 120, the rotation speed is 150r / min, and the feed rate is 200mm / min. During fine grinding, the grinding wheel mesh number is 200 and the grinding wheel width is 40mm.

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

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

[0017] Furthermore, in the step S6: after the QPQ heat treatment is completed, the outer circle is polished using the previous method and polishing is additionally performed using 2000 mesh emery paper.

[0018] An oil distribution shaft manufactured according to the processing method includes a bearing mounting shaft, a rotating hexagonal nut is provided at one end of the bearing mounting shaft, a connecting shaft is provided at the end of the rotating hexagonal nut away from the bearing mounting shaft, an external thread for connecting to an adapter is provided on the connecting shaft, a sealing shaft is provided at the other end of the bearing mounting shaft, a communicating oil hole is provided between the bearing mounting shaft and the sealing shaft, and a card slot is provided on the bearing mounting shaft.

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

[0020] Furthermore, an O-ring mounting 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 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 grinding. The size of the processed ellipse can be controlled within 0.002mm.

[0024] 2. The processing method of the oil distribution shaft of the present invention is to change the original green silicon carbide grinding wheel to 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 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 be unsatisfactory. This method effectively ensures processing accuracy. BRIEF DESCRIPTION OF THE DRAWINGS

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

[0027] Figure 2 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 practical application of the present invention.

[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 mounting groove, 8-bearing mounting shaft, 9-oil hole, 10-sealing washer, 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 Figure 1-3 , which is a processing method for an oil distribution shaft of the present invention. The method comprises the following steps: firstly turning the oil distribution shaft into an outer shape, then subjecting it to vacuum heat treatment, and then processing the center holes at both ends at one time. The oil distribution shaft is then subjected to rough grinding, followed by fine grinding. After grinding, the outer circle is polished for the first time, and after polishing, QPQ heat treatment is performed. The salt residue left by the QPQ heat treatment is then cleaned, and ultrasonic cleaning is performed. After cleaning, the outer circle is polished for the second time.

[0032] In this embodiment, there are a total of 10 processes, which is 5 processes less than the previous process, and it is unnecessary to clamp the outer circle in the subsequent processing, which greatly reduces the risk of clamping damage and damage during the process. 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 process. The processed 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 is changed from 100 mesh to 120 mesh, and the grinding wheel width is changed from 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 dimensional processing accuracy and roundness. A semi-fine grinding process is added between rough grinding and fine grinding to improve 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 includes the following specific steps:

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

[0035] S2: Vacuum heat treatment of the oil distribution shaft;

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

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

[0038] S5: Use a polishing machine to perform the first polishing on the bearing mounting shaft 8 and the sealing shaft 5 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;

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

[0040] Furthermore, in step S3, 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, the machining allowance for the car body should be within 0.25mm~0.3mm. If it is too much, it is easy to wear and affect the roughness quality. If it is too little, it is easy to not finish the flower. When machining the center hole, in order to achieve the roughness of the center hole, 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 the same time to improve the coaxiality of the center holes at both ends, which can reduce the slight vibration during the external cylindrical grinding process and effectively control the coaxiality of the center holes at both ends to be within 0.01.

[0042] Furthermore, in step S4, the grinding wheel of the grinder adopts SG small-pore grinding wheel, the grinding wheel mesh number is 120 mesh during rough grinding, the rotation speed is 150r / min, the feed rate is 200mm / min, and the grinding wheel mesh number is 200 mesh during fine grinding, and the grinding wheel width is 40mm.

[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 the original 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 is between 0.015 and 0.03 mm. If the roughness is too coarse and the remaining amount is too little, the fine grinding will not be sufficient. If the remaining amount is too much, the fine grinding will be easy to wear and the roughness will not be appropriate. A semi-fine grinding process may ensure the quality of subsequent fine grinding.

[0045] Furthermore, in step S5: a CNC lathe is used for rotational polishing at a rotation speed of 1500 r / min or more, and the outer circle of the sealing shaft 5 is first roughly polished with 1500-grit sandpaper, and then finely polished with 2000-grit sandpaper.

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

[0047] Furthermore, in step S6: after the QPQ heat treatment is completed, the outer circle is polished using the previous method, and 2000 mesh emery paper is added for polishing. Before the QPQ heat treatment, vacuum heat treatment is performed. The vacuum heat treatment adjusts the hardness of the material. When the hardness is high, the roughness of the product can be better optimized for grinding machine processing. After the vacuum heat treatment, the original QPQ heat treatment time is shortened. The original heating time in the salt bath nitriding furnace is shortened to 1.5 hours, which is 3.5 hours. The 1.5-hour salt bath nitriding furnace heating reduces the time, ensuring that the workpiece does not need to be heated in the furnace for a long time, which leads to a decrease in the tempering hardness. It can not only ensure the hardness, but also meet the salt spray test requirements of customers.

[0048] An oil distribution shaft, manufactured according to the above-mentioned processing method, includes a bearing mounting shaft 8, a rotating hexagonal nut 2 is provided at one end of the bearing mounting shaft 8, a connecting shaft 3 is provided at the end of the rotating hexagonal nut 2 away from the bearing mounting shaft 8, an external thread 4 is provided on the connecting shaft 3 for connecting to the adapter 16, a sealing shaft 5 is provided at the other end of the bearing mounting shaft 8, a communicating oil hole 9 is provided between the bearing mounting shaft 8 and the sealing shaft 5, and a card slot 6 is provided on the bearing mounting 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 hydraulic oil from leaking from the rotating part. The hydraulic oil flows in from the oil 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 improves the range of the oil distribution shaft and can be used in high-precision equipment for efficient long-term stable operation.

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

[0052] The above is only a preferred embodiment 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. These 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 is to first turn the oil distribution shaft into shape, then perform vacuum heat treatment on it, and then process the center holes at both ends at one time, then perform rough grinding on the oil distribution shaft, and then perform fine grinding after the rough grinding. After grinding, the outer circle is polished for the first time, and then QPQ heat treatment is performed after polishing. Then, the salt residue left by the QPQ heat treatment is cleaned, and ultrasonic cleaning is performed. After cleaning, the outer circle is polished for the second time. The specific steps are as follows: S1: Carry out the outer shape of the oil distribution shaft according to the design drawings, leaving a margin between 0.25mm and 0.3mm; S2: Vacuum heat treatment of the oil distribution shaft; S3: The center holes at both ends are processed by Swiss lathe, and 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 fine grinding after the rough grinding is completed; S5: The bearing mounting shaft (8) and the sealing shaft (5) of the oil distribution shaft are polished for the first time using a polishing machine. After polishing, the oil distribution shaft is subjected to QPQ heat treatment for 1.5 hours using a salt bath nitriding furnace; S6: Clean the salt residue in the inner hole with an ultrasonic cleaning machine, and then polish the oil distribution shaft for the second time with a polishing machine after cleaning; In step S3, when machining the center hole, the rotation speed is set to 1300 r / min and the feed rate is 0.03 mm / r; In step S4, the grinding wheel of the grinding machine adopts an SG small-pore grinding wheel. During rough grinding, the grinding wheel mesh number is 120, the rotation speed is 150 r / min, and the feed rate is 200 mm / min. During fine grinding, the grinding wheel mesh number is 200 and the grinding wheel width is 40 mm. In the step S4, a semi-finishing process is added before fine grinding, and the remaining grinding amount is between 0.015 and 0.03 mm.

2. The method for processing an oil distribution shaft according to claim 1, characterized in that: In the step S5, a CNC lathe is used for rotational polishing at a rotation speed of 1500 r / min or more, and the outer circle of the sealing shaft (5) is firstly rough-polished with 1500-mesh sandpaper, and then fine-polished with 2000-mesh sandpaper.

3. The method for processing an oil distribution shaft according to claim 1, characterized in that: In the step S6: after the QPQ heat treatment is completed, the outer circle is polished using the previous method and polishing is added with 2000 mesh emery paper.

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

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

05.

6. The oil distribution shaft according to claim 5, characterized in that: An O-ring mounting groove (7) for sealing is provided on the connecting shaft (3).

Images