A combined processing method for the armature assembly of an electro-hydraulic servo valve

Abstract

The present invention belongs to the field of electro-hydraulic servo valves and relates to a combined processing method for the armature assembly of an electro-hydraulic servo valve. The technological sequence is as follows: combining the feedback rod and the support tube into a support rod assembly → performing a sealing test on the feedback rod → machining the flat surface and jet grooves on the feedback rod → pressing the spring tube → removing the extended end → combining and welding the armature into an armature assembly → performing a sealing test on the spring tube. This method avoids the risk of overall scrapping once oil leakage occurs during the sealing test after the overall combination of the armature assembly in the past, saving manufacturing costs. Another part is that a combined fixture for the support rod assembly and a pressing fixture for the spring tube-support rod assembly are designed, and by designing the process extended end and process positioning holes of the parts, the accurate conversion of the reference is achieved, solving the problem that combination cannot be realized by traditional methods.

Description

Technical Field

[0001] The present invention belongs to the field of electro-hydraulic servo valves, and relates to a combined machining method for the armature assembly of a jet deflector valve, including the design of a combined fixture during the combination process. Background Art

[0002] In a jet deflector valve, the armature assembly is a core component. The armature assembly consists of four parts: a support tube, a feedback rod, an armature, and a spring tube. The four parts are processed according to requirements. The combined machining quality of the armature assembly determines the overall performance of the electro-hydraulic servo valve.

[0003] Currently, the traditional combination sequence and method for the armature assembly are as follows: First, the armature and the support tube are combined and welded into a support rod assembly. Then, the feedback rod is pressed in, flattened, and a jet groove is machined. Finally, the spring tube is pressed in to form the armature assembly, and a sealing test is carried out. The reason for the traditional combination sequence of first combining the armature and the support tube and then machining the surface of the feedback rod jet groove is that both the support tube and the feedback rod are shaft structures. After assembling the armature first, the angular position needs to be determined with the direction of the armature pole shoe to machine the flat surface and the jet groove of the feedback rod, and determine the positional relationship between the flat surface, the jet groove, and the armature pole shoe. When pressing in the spring tube, it is necessary to ensure the relative positions of the two mounting holes of the spring tube with the armature pole shoe and the feedback rod jet groove.

[0004] The following risk points exist in this combination method: The feedback rod has a slender structure and poor rigidity, and it is prone to deflection when the support tube is fitted with it. At the same time, due to the limitation of the machining technology inside the support tube, it is very difficult to ensure the internal coaxiality. The processes of flattening the feedback rod and machining the jet groove are slow wire electrical discharge machining. The thickness of the flat surface is thin, and the jet groove is a micro special-shaped hole, with high surface size and position accuracy, so the machining difficulty is large and it is easy to produce defective products. The unqualified parts generated in this process will lead to the scrapping of three parts: the armature, the support tube, and the feedback rod. The sealing test after pressing in the spring tube will detect the interference fit quality between the outer circle of the feedback rod and the inner hole of the support tube, as well as the fit quality between the inner hole of the spring tube and the outer circle of the support tube. If the oil leakage test fails, the four parts of the armature, the support tube, the feedback rod, and the spring tube will be scrapped (the oil leakage occurs on the mating surface between the outer circle of the feedback rod and the inner hole of the support tube). Summary of the Invention

[0005] The object of the present invention:

[0006] Design a new combination sequence and machining method to solve the problem that the combination of a new type of armature assembly cannot be achieved by traditional methods. At the same time, increase the requirements for the sealing test of the feedback rod, and screen in advance the failure of oil leakage on the mating surface between the feedback rod and the support tube, so as to avoid risks and save manufacturing costs.

[0007] The technical solution of the present invention:

[0008] A combined processing method for the armature assembly of an electro-hydraulic servo valve proposed by the present invention, the combined processing method comprising the following steps:

[0009] 1) The feedback rod and the support tube are combined into a support rod assembly;

[0010] 2) Conduct a sealing test on the feedback rod;

[0011] 3) Machine the flat surface and the jet groove on the feedback rod;

[0012] 4) Press in the spring tube to form a spring tube - support rod assembly;

[0013] 5) Remove the extended end of the support tube;

[0014] 6) Combine and weld the armature into an armature assembly;

[0015] 7) Conduct a sealing test on the spring tube.

[0016] Furthermore, the support tube is designed with a process extended end and a process positioning hole, thereby precisely converting the reference, and at the same time, a positioning pin is designed as a process armature to serve as the angular positioning reference for subsequent combination.

[0017] Furthermore, on the basis of the above processing method, in the first step, a combined fixture for the support rod assembly is also designed to ensure the relative positions of the two parts during the combination process, solving the problem of easy oil leakage in traditional combined processing.

[0018] Furthermore, the combined fixture for the support rod assembly includes: a support block 1, a positioning block 2, and a guiding block 3. It is characterized in that the positioning block 2 is installed between the support block 1 and the guiding block 3. The support block 1 and the positioning block 2 position and support the feedback rod 4, making the outer circle of the mating section of the feedback rod coaxial with the inner hole of the fixture. The guiding block 3 can ensure that the inner hole of the support tube 5 is coaxial with the outer circle of the feedback rod, ensuring uniform interference fit in the circumferential direction of the mating section; for the first time, the process of pressing the support tube (through-hole structure) into the feedback rod from the lower end is realized, avoiding the sharp edges on the step hole edge of the support tube from scratching the outer circle of the feedback rod and squeezing out burrs, resulting in oil leakage, and improving the mating accuracy and qualification rate of the two.

[0019] Furthermore, for the first time, the requirement for the sealing test of the feedback rod is increased, and the faults of oil leakage on the mating surface of the feedback rod and the support tube are screened in advance.

[0020] Furthermore, a process armature (the extended section at the upper end of the support tube) is designed, so that the flattening and jet groove cutting of the feedback rod are based on the process armature, completing the precise conversion of the positioning reference.

[0021] Furthermore, in step 4, a pressing fixture for the spring tube - support rod assembly is designed, so that the thin wall of the spring tube is not stressed during the pressing process and the pressing dimensions and accuracy are ensured.

[0022] Furthermore, the bellows - rod assembly pressing fixture includes: a bellows support 1, a pin shaft 2, a bellows positioning block 3, a bellows positioning pin 4, a positioning pin 5, a nut 6, a bellows 7, and a rod assembly 8. It is characterized in that the rod assembly 8 and the positioning pin 5 are loaded into the split - type bellows support 1. The positioning pin 5 serves as a technological armature to obtain an angular positioning reference. Then, the small - end face of the bellows 7 is supported by the bellows support 1, and the two split parts of the bellows support 1 are connected by the taper pin 2. The bellows 7 is connected to the bellows positioning block 3 through the bellows positioning pin 4 to play a positioning role, ensuring the relative positions of the two installation holes of the bellows, the technological armature, and the jet groove of the feedback rod; at the same time, ensuring that the thin - wall of the bellows is not stressed; the accurate conversion of the reference is completed through the technological armature, that is, the positioning pin 5, solving the problem that the bellows pressing cannot be achieved by traditional methods.

[0023] Advantages of the present invention:

[0024] 1. A combined processing method for the armature assembly of an electro - hydraulic servo valve, which has two parts: one part is that the method adopts a new combination sequence, that is, the feedback rod and the support tube are combined into a rod assembly → the sealing test of the feedback rod → machining the flat surface and the jet groove on the feedback rod → pressing the bellows → removing the extended end → combining and welding the armature into an armature assembly → the sealing test of the bellows. This method avoids the risk of overall scrapping once oil leakage occurs during the sealing test after the overall combination of the armature assembly in the past, saving manufacturing costs; the other part is that a combined fixture for the rod assembly, a bellows - rod assembly pressing fixture are designed, and by designing the process extended end and the process positioning hole of the part, the accurate conversion of the reference is achieved, solving the problem that the combination cannot be achieved by traditional methods.

[0025] 2. When machining the support tube, an extended end and a process positioning hole are reserved, and a technological armature is designed, which can accurately convert the reference.

[0026] 3. In the combined fixture for the rod assembly, there are high coaxiality requirements for the positioning block and the support block, ensuring the relative positions of the two parts during the combination process and not deforming or bending the feedback rod.

[0027] 4. The requirement for the sealing test of the feedback rod is increased, screening in advance for the failure of oil leakage at the mating surface of the feedback rod and the support tube, thus avoiding risks.

[0028] 5. In the bellows - rod assembly combined fixture, the bellows support adopts a split - type structure to ensure that the thin - wall of the bellows is not stressed during the pressing process.

[0029] 6. The sharp edges of the support in the bellows - rod assembly pressing fixture are all rounded and polished to ensure that the outer - circle surface of the bellows is not damaged during the pressing process. Description of the Drawings

[0030] Figure 1 Schematic diagram of the combination sequence of the armature assembly in a method for combined machining of an electro-hydraulic servo valve armature assembly;

[0031] Figure 2 Schematic diagram of the combined fixture for the strut assembly in a method for combining the armature assembly of an electro-hydraulic servo valve;

[0032] Figure 3 Schematic diagram of the press-fitting fixture for the bellows-strut assembly in a method for combining the armature assembly of an electro-hydraulic servo valve. Detailed implementation manner

[0033] The present invention application provides a method for combined machining of an electro-hydraulic servo valve armature assembly. Aiming at the risk points existing in the traditional combined machining method of the armature assembly; such as Figure 1 This is the new combined machining method of the present invention, and the position and function of the core invention points. The combination process of the present invention mainly includes the combination of the strut assembly, the sealing test of the feedback rod, the machining of the strut assembly, and the press-fitting process of the bellows. The specific combination sequence is as follows:

[0034] Combining the feedback rod and the support tube to form the strut assembly → Sealing test of the feedback rod → Machining the flat surface and jet groove on the feedback rod → Pressing the bellows → Removing the extended end → Combining and welding the armature to form the armature assembly → Sealing test of the bellows.

[0035] This method reasonably avoids the risks existing in the traditional combined machining method and improves the machining qualification rate.

[0036] Figure 2 This is the combined fixture for the strut assembly, including: support block a1, positioning block a2, guiding block a3, feedback rod a4, support tube a5. First, the support block a1 and the positioning block a2 support and fix the feedback rod a4, then the guiding block a3 and the positioning block a2 are assembled, and finally the support tube a5 is inserted into the guiding block a3. The press head presses the upper end surface of the support block, so that under the action of the guiding block a3, the support tube and the feedback rod always ensure the correct axial

[0037] position and achieve interference press-fitting. When the lower end surface of the support tube a5 is in contact with the upper end surface of the support block a1, the press-in depth can ensure the axial dimension of the assembly.

[0038] Figure 3 This is the press-fitting fixture for the bellows-strut assembly, including: bellows support 1, pin shaft 2, bellows positioning block 3, bellows positioning pin 4, positioning pin 5, nut 6, bellows 7, strut assembly 8. The strut assembly 8 and the positioning pin 5 are inserted into the split-type bellows support 1, and the positioning pin 5 serves as a process armature to obtain

[0039] To the angular positioning reference, the small end face of the spring tube 7 is supported by the spring tube support 1 and the spring tube support 1 is connected with the pin 20, and the spring tube 7 is connected with the spring tube positioning block 3 through the spring tube positioning pin 4.

[0040] The connection plays a positioning role, while ensuring that the large end face of the spring tube 7 does not contact the upper surface of the spring tube positioning block 3. The pressure head presses the upper end face of the support tube to make the upper end face of the spring tube flush with the lower end face of the support tube step. At this point, the assembly is completed and the assembly is removed from the fixture.

[0041] The present invention is based on a new armature assembly structure, which not only solves the problem of interference between press-fit parts in the assembly parts structure according to the traditional assembly sequence and method, but also avoids the risk points of the traditional assembly process, and improves

[0042] The specific armature assembly processing method provides a new assembly sequence and processing method for the armature assembly of the electro-hydraulic servo valve. By designing the process extension end and process positioning hole of the parts and converting the reference, the problem of being unable to achieve assembly in the traditional sequence is solved.

[0043] For the first time, the assembly uses a method in which a through-hole support tube is pressed into the feedback rod from the bottom, and a special fixture is designed, which improves the matching accuracy and qualified rate of the two and reduces the difficulty of deburring and polishing the inner hole of the support tube step.

[0044] For the first time, the feedback rod sealing test requirement was added, and the oil leakage faults on the mating surface of the feedback rod and the support tube were screened in advance; this method avoided the risk of the whole armature assembly being scrapped once oil leakage occurred after the sealing test was conducted after the whole armature assembly was assembled, thus avoiding the risk and saving manufacturing costs. This method can be extended to the design schemes and processing methods of all other armature assemblies.

[0045] 5 The present invention is described in detail above in conjunction with the drawings or specific implementation examples of the specification. It should be noted that some (but not all) of the disclosed examples are shown in the drawings. In fact, many different examples can be described and these examples should not be understood as being limited to the examples described herein. On the contrary, describing these examples makes the positive effects of the present invention more evident, and any parts not described in detail herein are considered to be well-known technologies or conventional technical means in the art.

Claims

1. A combined machining method for an armature assembly of an electro-hydraulic servo valve, characterized in that, The combined processing method includes the following steps: 1) Combine the feedback rod and the support tube into a support rod assembly; 2) Conduct a hydraulic test to check the sealing performance of the mating surface between the feedback rod and the support tube; 3) Machine the flat surface and the jet groove on the feedback rod; 4) Press in the spring tube to form a spring tube - support rod assembly; 5) Remove the extended end of the support tube; 6) Combine the armature with the spring tube - support rod assembly and weld the mating surface to form an armature assembly; 7) Conduct a hydraulic test for the sealing performance test of the mating surface between the spring tube and the support tube; The support tube is designed with a process extended end and a process positioning hole. By installing a positioning pin in the process positioning hole as a process armature, the reference is accurately converted.

2. A combined machining method for an armature assembly of an electro-hydraulic servo valve according to claim 1, characterized in that In step 1), a combined fixture for the support rod assembly is designed, so that the feedback rod and the support tube always maintain the correct relative position during the interference press - fitting process, ensuring the press - fitting quality.

3. A combined machining method for the armature assembly of an electro-hydraulic servo valve according to claim 2, characterized in that, The combined fixture for the support rod assembly includes: a support block, a positioning block, and a guiding block. The positioning block is installed between the support block and the guiding block. The support block and the positioning block position and support the feedback rod, making the outer diameter of the mating section of the feedback rod coaxial with the inner hole of the fixture. The guiding block can ensure that the inner hole of the support tube is coaxial with the outer diameter of the feedback rod, ensuring uniform interference in the circumferential direction of the mating section; the support tube is pressed into the feedback rod from the lower end.

4. A combined machining method for an armature assembly of an electro-hydraulic servo valve according to claim 1, characterized in that During the sealing inspection, through the sealing test, observe whether there is oil leakage at the mating surface between the feedback rod and the support tube.

5. A combined machining method for an armature assembly of an electro-hydraulic servo valve according to claim 1, characterized in that A process armature is designed, so that the flattening and grooving of the feedback rod are based on the process armature, completing the accurate conversion of the positioning reference.

6. A combined machining method for an armature assembly of an electro-hydraulic servo valve according to claim 1, characterized in that In step 4), a press - fitting fixture for the spring tube - support rod assembly is designed, so that the thin wall of the spring tube is not stressed during the press - fitting process and the press - fitting dimensions and accuracy are ensured.

7. A combined machining method for an armature assembly of an electro-hydraulic servo valve according to claim 6, characterized in that, The press - fitting fixture for the spring tube - support rod assembly includes: a spring tube support, a pin shaft, a spring tube positioning block, a spring tube positioning pin, a positioning pin, a nut, a spring tube, and a support rod assembly. Install the support rod assembly and the positioning pin into the split - type spring tube support. The positioning pin serves as a process armature to obtain an angular positioning reference. Then, use the spring tube support to support the small - end face of the spring tube, and connect the left and right parts of the spring tube support with a taper pin. Connect the spring tube and the spring tube positioning block through the spring tube positioning pin to play a positioning role, ensuring the relative positions of the two installation holes of the spring tube, the process armature, and the jet groove of the feedback rod; at the same time, ensuring that the thin wall of the spring tube is not stressed; the accurate conversion of the reference is completed through the process armature, that is, the positioning pin.

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