Process method for processing sensor shell

Abstract

The invention relates to a process method for processing a sensor shell, which comprises the following steps of: 1, processing a bushing finished product, an induction sheet finished product and a pressure head according to the size requirements of the bushing and the pressure head, 2, processing an inner hole at the mounting part of the bushing to a pattern size, and reserving the processing allowance for the rest part, and 3, applying pressure to the large end of the pressure head by using a press machine, the method comprises the following steps of: 1, pressing a lining into an inner hole of a shell, 4, processing the inner hole of the shell assembly after press fitting to a final size, 5, welding an induction sheet and the shell into a whole by using laser welding equipment, and carrying out a sealing test on a welding seam, 6, carrying out magnetic annealing on the shell assembly, and 7, carrying out supplementary processing on the shell assembly by using a lathe. And 8, the outer surface of the shell is scrubbed through a passivation solution, an oxidation film is formed on the surface of the shell, and the shell assembly machined through the technological method is accurate in size, good in welding sealing performance and corrosion resistance and high in qualified rate of machined products.

Description

Technical Field

[0001] The invention relates to the technical field of sensor housing processing, and in particular to a processing method for sensor housing processing. Background Art

[0002] Sensors are increasingly used in aerospace products and other fields. Many existing sensors are usually composed of a housing, internal sensing elements, and control circuits. In addition to being used to install the sensor, the housing is more importantly used to protect the internal components to ensure the accuracy and reliability of the sensor during use. In the production and processing of some sensors, the housing has higher quality requirements. For the processing of the sensor housing, it is necessary to formulate a process method that meets production requirements. Summary of the invention

[0003] In order to solve the problems mentioned in the above background technology, the present invention provides a process method for processing a sensor housing.

[0004] The present invention discloses the following technical solution: a process method for processing a sensor housing, comprising a pressure head tooling, the pressure head is a cylindrical structure with multiple diameters, the small end of the pressure head can be matched with the inner diameter of the bushing, a press machine is used to apply pressure to the large end of the pressure head, and the bushing is installed to the inner hole of the housing. The specific processing method is as follows: Step 1: Process the bushing, sensor plate and pressure head. Use a lathe to process the finished bushing, sensor plate and pressure head according to the size requirements of the bushing and pressure head.

[0005] Step 2: Rough machining of the shell. Use a lathe to machine the inner hole and outer wall of the shell. The inner hole at the bushing installation location is machined to the drawing size, and the rest of the parts are left with machining allowance.

[0006] Step 3: Press-fit the bushing. The inner hole of the bushing is assembled with the small end of the pressure head. The upper end face of the bushing is in contact with the end face of the step above the small end of the pressure head. The rough-machined shell is placed vertically on the workbench of the press with the bushing mounting hole facing upward. The pressure head and the bushing are placed vertically into the inner hole of the shell. Use the press to apply pressure to the large end of the pressure head. Press the bushing into the inner hole of the shell and then take out the pressure head.

[0007] Step 4: Boring the inner hole of the outer shell, and processing the inner hole of the outer shell after press-fitting to the final size.

[0008] Step 5: Laser welding: install the sensor piece to the φ10mm inner hole of the shell, make the inner end surface flat, use laser welding equipment to weld the sensor piece and the shell into a whole to make a shell assembly, and conduct a sealing test on the shell assembly, input 0.6MP air pressure into the inner cavity of the shell assembly and maintain it for more than 1 minute.

[0009] Step 6: Magnetic annealing: heat the shell assembly to 1150°C in a vacuum environment, keep it warm for 2 hours, and cool it naturally to room temperature.

[0010] Step 7: Finishing of the shell: Use a lathe to process the shell components, process the outer wall of the shell to the final size, and check the processing dimensions and sealing.

[0011] Step 8: Surface passivation treatment: Use a passivation liquid to scrub the outer surface of the shell component to form an oxide film on the surface of the shell component.

[0012] Furthermore, in step 2, the thickness of the outer wall of the shell is left with a finishing allowance of 0.5 mm.

[0013] Furthermore, in step 2, step 4 and step 7, the cutting speed during the finish machining of the housing component is preferably (50-100) m / min, the cutting depth is controlled at (0.1-0.3) mm, and the feed rate is not greater than 1 mm / r.

[0014] Furthermore, the vacuum environment in step six is ​​preferably (5-10) Pa.

[0015] Furthermore, in step eight, the ratio of the passivation solution is: 5% nitric acid, 95% water. After scrubbing, keep it for 1 hour and then wash it with water.

[0016] Furthermore, the press in step three is a manual press.

[0017] Beneficial effects: Compared with the prior art, the sensor housing processing method of the present invention has a reasonable process arrangement, the processed housing component has accurate size, good welding sealing, good corrosion resistance of the housing component, meets the design requirements of the drawings, and has a high qualified rate of processed products. BRIEF DESCRIPTION OF THE DRAWINGS

[0018] Figure 1 It is a schematic diagram of the structure of the sensor housing assembly of the present invention; Figure 2 It is a schematic diagram of the pressure head structure of the present invention; Figure 3 It is a schematic diagram of the bushing press-fitting of the present invention; In the figure: 1-housing, 2-bushing, 3-sensing plate, 4-pressure head. DETAILED DESCRIPTION

[0019] like Figure 1As shown, the sensor housing assembly consists of a housing 1, a bushing 2 and a sensing piece 3. The housing 1 and the sensing piece 3 are made of austenitic stainless steel 1Cr18Ni9Ti, and the bushing 2 is made of iron-nickel-based soft magnetic alloy 1J79. Austenitic stainless steel 1Cr18Ni9Ti has excellent corrosion resistance. The iron-nickel-based soft magnetic alloy 1J79 is a magnetic material and should be subjected to magnetic annealing after machining to reduce the coercive force. The bushing 2 has an outer diameter of φ13.5mm and an inner diameter of φ10mm. The bushing 2 is installed in the inner hole of the housing 1 with a diameter of φ13.5mm, where the wall thickness is 0.5mm. The sensing piece 3 is welded to the inner hole of the housing 1 with a diameter of φ13.5mm. The upper end face of the sensing piece 3 abuts against the bushing 2, and the lower end face of the sensing piece 3 is flush with the lower end face of the housing 1.

[0020] like Figures 2 to 3 As shown, the pressure head 4 is a cylindrical structure with multiple diameters, with an outer diameter of φ10 mm and a length of 20 mm at the smallest part, an outer diameter of φ13.4 mm in the middle part, and a fillet of R1 at the lower end of the outer diameter of φ10 mm.

[0021] A processing method for processing a sensor housing 1 includes a pressure head 4, the pressure head 4 is a cylindrical structure with multiple diameters, the small end of the pressure head 4 can match the inner diameter of the bushing 2, and a press machine is used to apply pressure to the large end of the pressure head 4 to install the bushing 2 into the inner hole of the housing 1. The specific processing method is as follows: Step 1: Process the bushing 2, the sensor plate 3 and the pressure head 4. According to the size requirements of the bushing 2 and the pressure head 4, use mechanical processing to process the bushing 2, the sensor plate 3 and the pressure head 4 into finished products.

[0022] Step 2: Rough machining of the shell 1. Use a lathe to machine the inner hole and outer wall of the shell 1. The inner hole at the installation of the bushing 2 is machined to the size of the drawing, and the remaining parts are left with a finishing allowance to ensure the wall thickness at the installation hole of the bushing 2 to prevent deformation during machining.

[0023] Step three: press-fit the bushing 2. The inner hole of the bushing 2 is assembled with the φ10mm outer diameter of the pressure head 4. The upper end face of the bushing 2 is abutted against the end face at the step between the φ10mm outer diameter and the φ13.4mm outer diameter of the pressure head 4. The rough-machined shell 1 is placed vertically on the press workbench with the mounting hole of the bushing 2 facing upward. The pressure head 4 and the bushing 2 are vertically placed in the inner hole of the shell 1. Use the press to apply pressure to the large end of the pressure head 4. After the bushing 2 is press-fitted into the inner hole of the shell 1, the pressure head 4 is taken out. Using the pressure head 4 to press-fit the bushing 2 can prevent the bushing 2 and the shell 1 from deforming.

[0024] Step 4: boring the inner hole of the outer shell 1, and processing the inner hole of the press-fitted outer shell 1 to the final size.

[0025] Step 5: Laser welding. Install the sensor piece 3 to the φ10mm inner hole of the shell 1. The outer end surface is flush. Use laser welding equipment to weld the sensor piece 3 and the shell 1 into a shell assembly. Perform a sealing test on the weld. Input 0.6MP air pressure into the inner cavity of the shell assembly and keep it leak-proof for more than 1 minute.

[0026] Step 6: Magnetic annealing: heat the shell assembly to 1150°C in a vacuum environment, keep it warm for 2 hours, and naturally cool it to room temperature to reduce the coercive force generated during the processing of the bushing 2 and remove the stress generated during laser welding.

[0027] Step 7: Finishing of the shell 1: Use a lathe to process the shell 1, process the outer wall of the shell 1 to the final size, check each processing size, and ensure that the outer diameter size, surface roughness, etc. meet the requirements of the drawing.

[0028] Step 8: Surface passivation treatment: Use passivation liquid to scrub the outer surface of the shell component to form an oxide film on the surface of the shell component to improve the corrosion resistance.

[0029] In step 2, the wall thickness of the outer wall of the shell 1 is left with a finishing allowance of 0.5mm, and the hole wall thickness of the shell 1 where the bushing 2 is installed after rough processing is 1.3mm, which can prevent deformation when the bushing 2 is pressed; when processing the shell 1 in steps 2, 4 and 7, due to the high hardness of the shell 1 material, the cutting speed is preferably (50-100) m / min, the cutting depth is controlled at (0.1-0.3) mm, and the feed rate is not more than 1mm / r to ensure the surface quality of the processing. The vacuum environment in step 6 is preferably (5-10) Pa, and the passivation liquid ratio in step 8 is: 5% nitric acid, 95% water, and it is kept for 1 hour after scrubbing and then washed with water to ensure that an oxide film is formed on the surface of the shell component; the press in step 3 can be a manual press, which is convenient for the operator to observe and control the strength when pressing the bushing 2. The shell component processed by the above method has accurate size, good welding sealing and corrosion resistance, meets the design requirements of the drawings, and has a high qualified rate of processed products.

[0030] The above description is only a preferred specific implementation manner of the present invention, but the protection scope of the present invention is not limited thereto. Any technician familiar with the technical field can make equivalent replacements or changes according to the technical scheme and inventive concept of the present invention within the technical scope disclosed by the present invention, which should be covered by the protection scope of the present invention.

Claims

1. A process for processing a sensor housing, characterized in that: It includes a pressure head, which is a cylindrical structure with multiple diameters. The small end of the pressure head can match the inner diameter of the bushing. A press is used to apply pressure to the large end of the pressure head to install the bushing into the inner hole of the shell. The specific processing method is as follows: Step 1: Process the bushing, sensor plate and pressure head. According to the size requirements of the bushing and pressure head, use mechanical processing to process the bushing, sensor plate and pressure head into finished products; Step 2: Rough machining of the shell, use a lathe to machine the inner hole and outer wall of the shell, the inner hole of the bushing installation is machined to the size of the drawing, and the rest is left with a finishing allowance; Step 3: Press-fit the bushing. The inner hole of the bushing matches the small end of the pressure head. The upper end face of the bushing abuts against the end face of the step above the small end of the pressure head to ensure that the bushing is pressed without distortion or deformation. The roughly machined shell is placed vertically on the press table with the bushing mounting hole facing upward. The pressure head and bushing are placed vertically into the inner hole of the shell. Use the press to apply pressure to the large end of the pressure head. Press the bushing into the inner hole of the shell and then withdraw the pressure head. Step 4: Boring the inner hole of the outer shell, and processing the inner hole of the press-fitted outer shell to the final size; Step 5: Laser welding: install the sensor piece to the φ10mm inner hole of the shell, and make the outer end face flush. Use laser welding equipment to weld the sensor piece and the shell into a shell assembly, and perform a sealing test on the weld. Step 6: Magnetic annealing: heat to 1150°C in a vacuum environment, keep warm for 2 hours, and cool naturally to room temperature; Step 7: Finishing of the shell: Use a lathe to process the shell components, process the outer wall to the final size, and check the processing dimensions and sealing performance; Step 8: Surface passivation treatment: Use passivation liquid to scrub the outer surface of the shell to form an oxide film on the surface of the shell.

2. The sensor housing processing method according to claim 1 is characterized in that: In step 2, the outer wall of the housing has a finishing allowance of 0.5 mm, and the end face of the sensing end has a finishing allowance of 0.1 mm.

3. The sensor housing processing method according to claim 1 is characterized in that: In step 2, step 4 and step 7, the cutting speed is preferably (50-100) m / min when finishing the shell, the cutting depth is controlled at (0.1-0.3) mm, the feed rate is not more than 1 mm / r, and the cooling method is selected from cutting fluids with good cooling effect such as emulsions and sulfurized oils.

4. The sensor housing processing method according to claim 1 is characterized in that: The vacuum environment in step six is ​​preferably (5-10) Pa.

5. The sensor housing processing method according to claim 1 is characterized in that: In step eight, the ratio of the passivation solution is: 5% nitric acid, 95% water. After scrubbing, keep it for 1 hour and then rinse with water.

6. The sensor housing processing method according to claim 1, characterized in that: The press in step three is a manual press.

7. The sensor housing processing method according to claim 1, characterized in that: The sealing test in step 5 is to input 0.6MP air pressure into the inner cavity of the shell and maintain it for more than 1 minute.

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