A precisely assembled spool-valve structure and method of manufacture

Abstract

The application relates to the technical field of valve core and valve body processing, and discloses a precisely-assembled valve core and valve body structure and a processing method, wherein the valve core is sleeved in the valve body, the valve body comprises a first valve body rod and a second valve body rod; the first valve body rod and the second valve body rod are in an integrated structure, the first valve body rod is internally provided with a inner hole, and the second valve body rod is internally provided with a precise inner hole; the valve core comprises a precise outer circle, a valve core rod and a valve core head; the precise outer circle is arranged at one end of the valve core rod, the valve core head is arranged at the other end of the valve core rod; the precise outer circle is matched with the precise inner hole, and the valve core head is arranged outside the first valve body rod through the valve core rod penetrating the inner hole, so that the valve core can be accurately assembled in the valve body, and it is guaranteed that the valve core and the valve body can normally work.

Description

Technical Field

[0001] This invention relates to the field of valve core and valve body processing technology, specifically to a precision-assembled valve core and valve body structure and processing method. Background Technology

[0002] Currently, the valve core and valve body of the fuel injector are crucial components of the fuel injection system, working together to ensure that fuel is precisely injected into the combustion chamber according to the engine's requirements. To meet the different operating conditions of aircraft engine fuel injectors, their structure often includes a valve core and valve body device that controls the timing of the nozzle's fuel circuit opening and closing, and supplies a fixed amount of fuel. The valve core and valve body device mainly consists of a valve body with multiple annular grooves in its inner bore, and a valve core with a throttling groove on its outer circumference. The performance of the valve core and valve body device is closely related to the precise fit between the valve core and valve body. This requires strict requirements not only on the cylindricity, dimensional consistency, and surface quality of the mating surfaces of the valve core and valve body, but also on the precise control of the mating clearance between them. Currently, it is impossible to achieve a one-time assembly qualification in the machining of fuel injector valve cores and valve bodies. Traditional machining processes for the inner bore and outer circumference of the valve core and valve body require multiple manual measurements and compensations, resulting in unstable control of the product dimensions and mating clearance, and low production efficiency. Therefore, there is an urgent need for a fast and accurate machining method for the precise mating surfaces of the valve core and valve body to ensure product quality. Summary of the Invention

[0003] In order to overcome the defects of the prior art, the purpose of this invention is to provide a precision-assembled valve core and valve body structure and processing method, so as to solve the technical problem of how to improve the one-time processing and assembly efficiency of valve core and valve body in the prior art.

[0004] This invention is achieved through the following technical solution:

[0005] In a first aspect, the present invention provides a precision-assembled valve core and valve body structure, including a valve body and a valve core;

[0006] The valve core is sleeved in the valve body; wherein the valve body includes a first valve body rod and a second valve body rod; the first valve body rod and the second valve body rod are integral structures, the first valve body rod has an inner hole, and the second valve body rod has a precision inner hole.

[0007] The valve core includes a precision outer circle, a valve core rod, and a valve core head; the precision outer circle is located at one end of the valve core rod, and the valve core head is located at the other end of the valve core rod.

[0008] The precision outer circle and the precision inner hole are matched, and the valve core head is disposed outside the first valve body rod through the valve core rod through the inner hole.

[0009] Preferably, the outer diameter of the first valve body rod is smaller than the outer diameter of the second valve body rod, and the outer diameter of the second valve body rod is larger than the inner diameter of the precision inner hole, wherein the inner hole and the precision inner hole are coaxially arranged.

[0010] Preferably, the end of the precision inner hole is provided with a first sealing surface, and the end of the precision outer circle is provided with a second sealing surface at the position corresponding to the first sealing surface, and the first sealing surface and the second sealing surface are abutted together.

[0011] Preferably, the valve core rod is provided with an outer circular sleeve, which is an integral structure with the valve core rod; the outer circular sleeve is clearance-fitted with the inner hole, and a limiting component is sleeved on the other end, forming a narrow groove with the valve core head; a spring is provided between the limiting component and the second valve body rod; wherein the spring is sleeved on the first valve body rod.

[0012] Furthermore, the limiting component includes a retaining ring and a limiting sleeve; the limiting sleeve is fitted onto the end of the outer circular sleeve, and a spring is provided between the limiting sleeve and the second valve body rod; wherein the spring is fitted onto the first valve body rod, and the retaining ring is provided between the limiting sleeve and the valve core head.

[0013] Secondly, the present invention also provides a method for processing a precision-assembled valve core and valve body structure, based on the above-described precision-assembled valve core and valve body structure, comprising the following processes:

[0014] The inner hole of the first valve body rod, the precision inner hole of the second valve body rod, and the first sealing surface are clamped and ground to the final dimensions to ensure the coaxiality of the three.

[0015] The inner hole of the first valve body rod, the precision inner hole of the second valve body rod, and the first sealing surface after grinding are cleaned to remove burrs.

[0016] The precision inner diameter of the second valve body rod was obtained through detection.

[0017] Set the outer circle fit clearance threshold, and automatically compensate the precision outer circle according to the detection value. Grind the outer circle sleeve and the narrow groove between the outer circle sleeve and the valve core head using the same positioning reference to ensure the coaxiality between the outer circle sleeve and the precision outer circle, and the perpendicularity between the narrow groove between the outer circle sleeve and the valve core head and the precision outer circle.

[0018] The machined valve core outer sleeve and precision outer circle are sequentially fitted into the inner hole of the first valve body rod and the precision inner hole of the second valve body rod, so that the fit clearance between the precision inner hole and the precision outer circle meets the clearance threshold, and the first sealing surface and the second sealing surface abut against each other, thus completing the machining.

[0019] Preferably, the coaxiality of the inner bore of the first valve body rod, the precision inner bore of the second valve body rod, and the first sealing surface is within Φ0.01mm; the cylindricity of the precision inner bore of the second valve body rod is within 0.004mm.

[0020] Preferably, the coaxiality of the outer sleeve, the precision outer circle, and the second sealing surface is within Φ0.01mm; the cylindricity of the precision outer circle is within 0.003mm.

[0021] Preferably, the perpendicularity between the narrow groove and the precision outer circle is within 0.01 mm.

[0022] Preferably, the precision inner diameter of the second valve body rod is detected, the fitting clearance between the precision inner diameter and the precision outer diameter is set, the theoretical diameter value of the precision outer diameter is calculated based on the precision inner diameter and the fitting clearance, the machine tool is automatically controlled to perform grinding, the precision outer diameter is detected in the machine tool after grinding and compared with the theoretical value, if it does not meet the requirements, automatic compensation machining is performed, and the precision outer diameter detection and automatic compensation machining in the machine tool are repeated until it meets the theoretical requirements.

[0023] Compared with the prior art, the present invention has the following beneficial technical effects:

[0024] This invention provides a precision-assembled valve core and valve body structure. The valve core is fitted into the valve body, which includes a first valve body rod and a second valve body rod. The first and second valve body rods are integrally formed. The first valve body rod has an inner hole, and the second valve body rod has a precision inner hole. The valve core includes a precision outer circle, a valve core rod, and a valve core head. The precision outer circle is located at one end of the valve core rod, and the valve core head is located at the other end. The precision outer circle mates with the precision inner hole, and the valve core head passes through the valve core rod and extends outside the inner hole, thus allowing the valve core to be accurately assembled into the valve body and ensuring normal operation of the valve core and valve body.

[0025] Furthermore, the outer diameter of the first valve body rod is smaller than the outer diameter of the second valve body rod, and the outer diameter of the second valve body is larger than the inner diameter of the precision inner hole, wherein the inner hole and the precision inner hole are coaxially arranged, which improves the accuracy of assembly.

[0026] Furthermore, the end of the precision inner bore is provided with a first sealing surface, and the end of the precision outer circle is provided with a second sealing surface at the position corresponding to the first sealing surface. The first sealing surface and the second sealing surface are abutted together, and the sealing between the valve core and the valve stem is ensured by the abutment positioning between the first sealing surface and the second sealing surface.

[0027] Furthermore, an outer sleeve is fitted on the valve core rod, one end of which is clearance-fitted with the first valve body rod, and the other end is fitted with a limiting component, forming a narrow groove with the valve core head; a spring is provided between the limiting component and the second valve body rod; wherein the spring is fitted on the first valve body rod, ensuring the working performance of the valve core and valve body.

[0028] Furthermore, the limiting component includes a retaining ring and a limiting sleeve; the limiting sleeve is fitted onto the end of the outer circular sleeve, and a spring is provided between the limiting sleeve and the second valve body rod; wherein the spring is fitted onto the first valve body rod, and the retaining ring is provided between the limiting sleeve and the valve core head, and the limiting sleeve ensures that the valve core is assembled onto the valve body.

[0029] This invention also provides a machining method for a precision-assembled valve core and valve body structure. The method involves detecting the precision inner diameter of the second valve body rod, inputting the detected value into a machine tool, and automatically compensating according to a set fit clearance threshold. This allows the grinding wheel for machining the valve core to reach the ideal position, effectively ensuring the valve core dimensions, form and position tolerances, and the precision fit clearance between them, thereby improving the machining quality and efficiency of the valve core and valve body.

[0030] Furthermore, the coaxiality of the inner bore of the first valve body rod, the precision inner bore of the second valve body rod, and the first sealing surface is within Φ0.01mm; the cylindricity of the precision inner bore of the second valve body rod is within 0.004mm; the coaxiality of the outer sleeve, the precision outer circle, and the second sealing surface is within Φ0.01mm; the cylindricity of the precision outer circle is within 0.003mm; and the perpendicularity between the narrow groove and the precision outer circle is within 0.01mm. By limiting the form and position tolerances, the first-pass yield of the valve core and valve body after assembly is effectively guaranteed. Attached Figure Description

[0031] Figure 1 This is a schematic diagram of the precision fit structure of the valve core and valve body in an embodiment of the present invention.

[0032] Figure 2 This is a schematic diagram of the valve body structure in an embodiment of the present invention;

[0033] Figure 3 for Figure 2 Enlarged diagram of part A in the middle;

[0034] Figure 4 This is a schematic diagram of the valve core structure in an embodiment of the present invention;

[0035] In the diagram: 1-Valve body; 2-Valve core; 3-Spring; 4-Snap ring; 5-Limit sleeve; 11-First valve body rod; 12-Second valve body rod; 13-Inner hole; 14-Precision inner hole; 15-First sealing surface; 21-Outer sleeve; 22-Valve core rod; 23-Precision outer circle; 24-Second sealing surface; 25-Valve core head Detailed Implementation

[0036] To enable those skilled in the art to better understand the present invention, the technical solutions of the present invention will be clearly and completely described below with reference to the accompanying drawings of the embodiments of the present invention. Obviously, the described embodiments are only some embodiments of the present invention, and not all embodiments. Based on the embodiments of the present invention, all other embodiments obtained by those skilled in the art without creative effort should fall within the scope of protection of the present invention.

[0037] It should be noted that the terms "first," "second," etc., in the specification, claims, and accompanying drawings of this invention are used to distinguish similar objects and are not necessarily used to describe a specific order or sequence. It should be understood that such data can be interchanged where appropriate so that the embodiments of the invention described herein can be implemented in orders other than those illustrated or described herein. Furthermore, the terms "comprising" and "having," and any variations thereof, are intended to cover a non-exclusive inclusion; for example, a process, method, system, product, or apparatus that comprises a series of steps or units is not necessarily limited to those steps or units explicitly listed, but may include other steps or units not explicitly listed or inherent to such processes, methods, products, or apparatus.

[0038] The present invention will now be described in further detail with reference to the accompanying drawings:

[0039] In order to overcome the defects of the prior art, the present invention aims to provide a precision-assembled valve core and valve body structure and processing method. By adopting automatic detection and automatic compensation, the grinding wheel for processing the valve core reaches the ideal position in one go, which effectively ensures the valve core size, form and position tolerances and the precision fit clearance between the two, and improves the processing quality and efficiency of the valve core and valve body, so as to solve the technical problem of how to improve the one-time processing and assembly efficiency of the valve core and valve body in the prior art.

[0040] Example 1

[0041] See Figure 1 , Figure 2 , Figure 3 and Figure 4 In one embodiment of the present invention, a precision-assembled valve core and valve body structure is provided, including a valve body 1 and a valve core 2;

[0042] The valve core 2 is sleeved inside the valve body 1; wherein the valve body 1 includes a first valve body rod 11 and a second valve body rod 12; the first valve body rod 11 and the second valve body rod 12 are integrally structured, the first valve body rod 11 is provided with an inner hole 13, and the second valve body rod 12 is provided with a precision inner hole 14.

[0043] The valve core 2 includes a precision outer circle 23, a valve core rod 22, and a valve core head 25; the precision outer circle 23 is disposed at one end of the valve core rod 22, and the valve core head 25 is disposed at the other end of the valve core rod 22.

[0044] The precision outer circle 23 mates with the precision inner hole 14, and the valve core head 25 passes through the inner hole 13 via the valve core rod 22 and is located outside the first valve body rod 11.

[0045] Specifically, the outer diameter of the first valve body rod 11 is smaller than the outer diameter of the second valve body rod 12, and the outer diameter of the second valve body rod 12 is larger than the inner diameter of the precision inner hole 14, wherein the inner hole 13, the precision inner hole 14, and the first sealing surface 15 are coaxially arranged.

[0046] In this embodiment, the outer diameter of the first valve body rod 11 is smaller than the outer diameter of the second valve body rod 12, and the outer diameter of the second valve body rod 12 is larger than the inner diameter of the precision inner hole 14. The inner hole 13, the precision inner hole 14, and the first sealing surface 15 are coaxially arranged, which enables the valve body and the valve core to be quickly assembled, and the first valve body rod 11 can be assembled on the valve core rod 22, thus improving the accuracy of assembly.

[0047] Specifically, the end of the precision inner hole 14 is provided with a first sealing surface 15, and the end of the precision outer circle 23 is provided with a second sealing surface 24 at the position corresponding to the first sealing surface 15. The first sealing surface 15 and the second sealing surface 25 are abutted together.

[0048] In this embodiment, the second sealing surface 24 at the end of the precision outer circle 23 is provided with a first sealing surface 15 corresponding to the end of the precision inner hole 14. Both the first sealing surface 15 and the second sealing surface 24 are wedge-shaped surfaces, which effectively improves the sealing performance of the assembly between the valve body and the valve core.

[0049] Specifically, an outer sleeve 21 is provided on the valve core rod 22, wherein the outer sleeve 21 and the valve core rod 22 are integrally structured. The outer sleeve 21 is clearance-fitted with the first valve body rod 11, and a limiting component is sleeved on the other end, forming a narrow groove with the valve core head 25. A spring 3 is provided between the limiting component and the second valve body rod 12. The spring 3 is sleeved on the first valve body rod 11.

[0050] The limiting component includes a retaining ring 4 and a limiting sleeve 5; the limiting sleeve 5 is fitted onto the end of the outer circular sleeve 21, and a spring 3 is provided between the limiting sleeve 5 and the second valve body rod 12; the spring 3 is fitted onto the first valve body rod 11, and the retaining ring 4 is provided between the limiting sleeve 5 and the valve core head 25.

[0051] In summary, the present invention provides a precision-assembled valve core and valve body structure. The valve core is fitted into the valve body 1, which includes a first valve body rod 11 and a second valve body rod 12. The first valve body rod 11 and the second valve body rod 12 are integrally formed. The first valve body rod 11 has an inner hole 13, and the second valve body rod 12 has a precision inner hole 14. The valve core 2 includes a precision outer circle 23, a valve core rod 22, and a valve core head 25. The precision outer circle 23 is located at one end of the valve core rod 22, and the valve core head 25 is located at the other end of the valve core rod 22. The precision outer circle 23 cooperates with the precision inner hole 14, and the valve core head 25 passes through the valve core rod 22 and extends through the inner hole 13, externally positioned outside the first valve body rod 11. This allows the valve core 2 to be accurately assembled into the valve body 1, improving assembly efficiency.

[0052] Example 2

[0053] The present invention also provides a method for processing a precision-assembled valve core and valve body structure, based on the above-described precision-assembled valve core and valve body structure, comprising the following processes:

[0054] The inner hole 13 of the first valve body rod 11, the precision inner hole 14 of the second valve body rod 12, and the first sealing surface 15 are clamped and machined on an internal cylindrical grinding machine to ensure that the coaxiality between the three is controlled within Φ0.01mm after machining, and the cylindricity of the precision-fitted inner hole is controlled within 0.004mm.

[0055] After the first valve body rod 11 and the second valve body rod 12 are axially fixed, a brush that matches the inner hole size of the valve body rod 11 is used to rotate and reciprocate to remove the burrs in the inner hole 13, the precision inner hole 14 of the second valve body rod 12 and the first sealing surface 15.

[0056] Clean the first valve body rod 11 and the second valve body rod 12;

[0057] A detection device is installed outside the external cylindrical grinding machine. One end of the detection device is connected to a probe for detecting the diameter of the precision inner hole 14 of the second valve body rod 12, and the other end is connected to the external cylindrical grinding machine control system for feeding back the detected precision inner hole 14 and the actual value of the diameter of the second valve body rod 12 to the external cylindrical grinding machine.

[0058] The external cylindrical grinding machine automatically compensates the CNC program based on the measured diameter of the precision inner hole 14 of the second valve body rod 12 and the set outer cylindrical fit clearance threshold, ensuring that the grinding wheel automatically grinds the precision outer diameter 23 and that the cylindricity of the precision outer diameter 23 is controlled within 0.003mm.

[0059] Using the same positioning reference, the outer sleeve 21 fitted on the valve core rod 22 is ground to ensure that the coaxiality of the outer sleeve 21 with the precision outer circle 23 and the second sealing surface 24 is not greater than Φ0.01mm;

[0060] Using the same positioning datum, the narrow groove between the outer sleeve 21 and the valve core head 25 is ground to ensure that the perpendicularity between the narrow groove and the precision outer circle 23 is no greater than 0.01mm. This completes the precision machining of the fuel injector valve core and valve body for a precise fit.

[0061] After assembling the pre-processed valve body 1 and valve core 2 to form a component, the first sealing surface 15 and the second sealing surface 24 are lapped together to ensure that the surface roughness is not less than Ra0.1μm.

[0062] In summary, traditional machining processes for the inner and outer diameters of valve cores and bodies require multiple manual measurements and compensations, resulting in unstable control of product dimensions and fit clearances, and low production efficiency. However, the present invention provides a precise machining method for the precision-fitting surfaces of fuel injector valve cores and bodies. This method employs automatic detection and compensation, allowing the grinding wheel to reach the ideal position in a single pass, effectively ensuring the valve core dimensions, form and position tolerances, and precise fit clearances between them, thus improving the machining quality and efficiency of the valve core and body.

[0063] Example 3

[0064] Taking a fuel injector valve core and valve body as an example, the specific implementation method of the precision assembly valve core and valve body structure provided by the present invention is as follows:

[0065] 1. The inner hole 13 of the first valve body rod 11, the precision inner hole 14 of the second valve body rod 12, and the first sealing surface 15 are machined in a single clamping and grinding process to ensure that the diameter of the precision inner hole 14 of the second valve body rod 12 is within Φ14.27+0.004mm, the cylindricity is not greater than 0.004mm, the coaxiality of the inner hole 13 of the first valve body rod 11 and the precision inner hole 14 of the second valve body rod 12 is not greater than Φ0.01mm, and the coaxiality of the first sealing surface 15 and the precision inner hole 14 is not greater than Φ0.01mm.

[0066] 2. Use a brush with a diameter of Φ14.3 to rotate and reciprocate within the precision inner hole Φ14.27+0.004mm to remove burrs from the inner hole annular groove;

[0067] 3. Clean the first valve body rod 11 and the second valve body rod 12 thoroughly;

[0068] 4. A detection device installed outside the cylindrical grinding machine is used to place the precision-fitted inner hole of the valve body on the probe, detect that the diameter of the precision inner hole 14 of the second valve body rod 12 is Φ14.272mm, and feed the detection result back to the cylindrical grinding machine;

[0069] 5. Based on the inner hole inspection result of Φ14.272mm and the set fit clearance of 0.004mm, the CNC machining program of the external cylindrical grinding machine is automatically compensated and adjusted to ensure that the grinding wheel reaches the optimal grinding position, so as to achieve a precision machining dimension of Φ14.268mm for the outer diameter and an outer diameter cylindricity of 0.002mm.

[0070] 6. The valve core is positioned by the center holes at both ends, and the outer sleeve 21 is ground to ensure that the coaxiality of the outer sleeve 21 and the precision outer circle 23 is Φ0.005mm;

[0071] 7. Positioning is achieved by using the center holes at both ends of the valve core, and the narrow groove between the outer sleeve 21 and the valve core head 25 is ground to ensure that the perpendicularity between the narrow groove and the precision outer circle 23 is 0.01mm;

[0072] 8. Perform a complete set of lapping on the first sealing surface 15 and the second sealing surface 24 to ensure a surface roughness of Ra0.1μm;

[0073] In summary, the present invention also provides a machining method for a precision-assembled valve core and valve body structure. By detecting the precision inner diameter of the second valve body rod, the detected value is input to the machine tool. The machine tool automatically compensates according to the set outer diameter fit clearance threshold, so that the grinding wheel for machining the valve core reaches the ideal position in one go. This effectively ensures the valve core size, form and position tolerances, and the precision fit clearance between them, improves the machining quality and efficiency of the valve core and valve body, and achieves the goal of passing the fuel injector valve core and valve body machining in one go.

[0074] Finally, it should be noted that the above embodiments are only used to illustrate the technical solutions of the present invention and not to limit it. Although the present invention has been described in detail with reference to the above embodiments, those skilled in the art should understand that modifications or equivalent substitutions can still be made to the specific implementation of the present invention. Any modifications or equivalent substitutions that do not depart from the spirit and scope of the present invention should be covered within the protection scope of the claims of the present invention.

Claims

1. A method for processing a precision-assembled valve core and valve body structure, wherein the precision-assembled valve core and valve body structure includes a valve body (1) and a valve core (2). The valve core (2) is sleeved inside the valve body (1); wherein the valve body (1) includes a first valve body rod (11) and a second valve body rod (12); the first valve body rod (11) and the second valve body rod (12) are integrally formed, the first valve body rod (11) has an inner hole (13), and the second valve body rod (12) has a precision inner hole (14). The valve core (2) includes a precision outer circle (23), a valve core rod (22), and a valve core head (25); the precision outer circle (23) is located at one end of the valve core rod (22), and the valve core head (25) is located at the other end of the valve core rod (22); The precision outer circle (23) is matched with the precision inner hole (14). The valve core head (25) passes through the inner hole (13) through the valve core rod (22) and is disposed outside the first valve body rod (11). The end of the precision inner hole (14) is provided with a first sealing surface (15). The end of the precision outer circle (23) is provided with a second sealing surface (24) at the position corresponding to the first sealing surface (15). The first sealing surface (15) and the second sealing surface (24) are abutted together. The valve core rod (22) is provided with an outer circular sleeve (21), and the outer circular sleeve (21) and the valve core rod (22) are an integral structure; characterized in that, The processing method includes the following steps: The inner hole (13) of the first valve body rod (11), the precision inner hole (14) of the second valve body rod (12), and the first sealing surface (15) are clamped and ground to the final size to ensure the coaxiality between the three. The inner hole (13) of the first valve body rod (11) after grinding, the precision inner hole (14) of the second valve body rod (12) and the first sealing surface (15) are cleaned to remove burrs; The inner diameter of the precision inner hole (14) of the second valve body rod (12) was measured. Set the outer circle fit clearance threshold, and automatically compensate the precision outer circle (23) according to the detection value. Grind the outer circle sleeve (21) and the narrow groove between the outer circle sleeve (21) and the valve core head (25) using the same positioning reference to ensure the coaxiality between the outer circle sleeve (21) and the precision outer circle (23), and the perpendicularity between the narrow groove between the outer circle sleeve (21) and the valve core head (25) and the precision outer circle (23). The machined valve core outer sleeve (21) and precision outer circle (23) are sequentially fitted into the inner hole (13) of the first valve body rod (11) and the precision inner hole (14) of the second valve body rod (12), so that the fit gap between the precision inner hole (14) and the precision outer circle (23) meets the gap threshold, and the first sealing surface (15) and the second sealing surface (24) abut against each other, thus completing the machining.

2. The processing method for a precision-assembled valve core and valve body structure according to claim 1, characterized in that, The outer diameter of the first valve body rod (11) is smaller than the outer diameter of the second valve body rod (12), and the outer diameter of the second valve body rod (12) is larger than the inner diameter of the precision inner hole (14), wherein the inner hole (13) and the precision inner hole (14) are coaxially arranged.

3. The processing method for a precision-assembled valve core and valve body structure according to claim 1, characterized in that, The outer sleeve (21) is fitted with the inner hole (13) with a clearance, and a limiting component is fitted on the other end, forming a narrow groove with the valve core head (25); a spring (3) is provided between the limiting component and the second valve body rod (12); wherein the spring (3) is fitted on the first valve body rod (11).

4. The processing method for a precision-assembled valve core and valve body structure according to claim 3, characterized in that, The limiting component includes a retaining ring (4) and a limiting sleeve (5); the limiting sleeve (5) is fitted onto the end of the outer circular sleeve (21), and a spring (3) is provided between the limiting sleeve (5) and the second valve body rod (12); the retaining ring (4) is provided between the limiting sleeve (5) and the valve core head (25).

5. The processing method for a precision-assembled valve core and valve body structure according to claim 1, characterized in that, The coaxiality of the inner hole (13) of the first valve body rod (11), the precision inner hole (14) of the second valve body rod (12), and the first sealing surface (15) is within Φ0.01mm; the cylindricity of the precision inner hole (14) of the second valve body rod (12) is within 0.004mm.

6. The processing method for a precision-assembled valve core and valve body structure according to claim 1, characterized in that, The coaxiality of the outer sleeve (21), the precision outer circle (23), and the second sealing surface (24) is within Φ0.01mm; the cylindricity of the precision outer circle (23) is within 0.003mm.

7. The processing method for a precision-assembled valve core and valve body structure according to claim 1, characterized in that, The perpendicularity between the narrow groove and the precision outer circle (23) is within 0.01 mm.

8. The processing method for a precision-assembled valve core and valve body structure according to claim 1, characterized in that, The diameter of the precision inner hole (14) of the second valve body rod (12) is detected, and the fitting clearance between the precision inner hole (14) diameter and the precision outer circle (23) is set. The theoretical diameter value of the precision outer circle (23) is calculated based on the precision inner hole (14) diameter and the fitting clearance. The machine tool is automatically controlled to perform grinding. After the grinding, the diameter of the precision outer circle (23) is detected in the machine tool and compared with the theoretical value. If it does not meet the requirements, automatic compensation processing is performed. The diameter detection and automatic compensation processing of the precision outer circle (23) in the machine tool are repeated until the theoretical requirements are met.

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