Design method of internal thread for accumulator connection of high-pressure hydraulic control module

Abstract

The application discloses a high-pressure hydraulic control module accumulator connection inner thread design method and particularly relates to the accumulator improvement field, which comprises the following steps: S1: sketching a 2D drawing, issuing a temporary sample to a valve plate supplier for assembly verification; S2: determining a design scheme through progressive detailed verification and adjustment, and assembling, verifying and approving by quality department personnel; and S3: arranging a technical switching plan. The application avoids a 2-buckle thread on the head of the accumulator by removing the 2-buckle inner thread at the bottom of the valve plate through a newly designed inner thread structure. Firstly, the physical assembly verification is carried out, and satisfactory results are obtained, that is, no aluminum is cut during screwing in and out; then, the formal design change process is entered, and the verification and approval are carried out through 3D checking and CAE analysis simulation means; finally, the module single durability test verification is carried out, and the vibration test and the charge and discharge pressure durability test are successfully passed; in conclusion, the new design passes the design verification and the assembly verification, and can enter the mass production state.

Description

Technical Field

[0001] This invention relates to the field of accumulator improvement technology, and more specifically, to a design method for the internal thread connection of a high-pressure hydraulic control module accumulator. Background Technology

[0002] When developing high-pressure hydraulic control modules, an accumulator, as an energy storage device, is an essential component. It is installed at an internal threaded interface on the valve plate of the module, with a tightening torque of 150 Nm. Existing high-pressure hydraulic control modules frequently experience valve jamming issues reported by after-sales service personnel. Summary of the Invention

[0003] In order to overcome the above-mentioned defects of the prior art, the embodiments of the present invention provide a design method for the internal thread of the accumulator connection of the high-pressure hydraulic control module, which is the technical problem to be solved by the present invention mentioned in the background art.

[0004] To achieve the above objectives, the present invention provides the following technical solution: a method for designing the internal thread of the accumulator connection in a high-pressure hydraulic control module, the specific design steps of which are as follows:

[0005] S1: Draw a 2D sketch and send it to the valve plate supplier to manufacture a temporary prototype for assembly verification;

[0006] S2: After progressive and detailed verification and adjustment, the design scheme is determined and then assembled, verified, and approved by the quality department personnel.

[0007] S3: Alignment technology switching plan;

[0008] S4: Design formal 2D drawings and 3D models, and perform 3D assembly checks in parallel;

[0009] S5, Dimension Chain Verification;

[0010] Internal verification of the module passed: verification of the module's own dimensional proportions and dimensional chain;

[0011] Customer's gearbox end verification passed: ensuring that the assembly dimension chain between the module and the gearbox mating level remains unchanged and has been verified;

[0012] S6: Perform threaded connection strength verification, supported by the accumulator supplier;

[0013] Thread connection length verification: The given thread length calculation formula is as follows:

[0014] and

[0015] calculate:

[0016]

[0017] in conclusion:

[0018]

[0019] Among them, f shmax D represents the maximum allowable shear stress of the valve plate material, in MPa. i The valve plate inner diameter is in mm; PS is the accumulator's maximum design operating pressure in MPa; L e E represents the thread length in mm. smin f is the pitch diameter of the internal thread, in mm; sh f represents the allowable shear stress of the valve plate material, in MPa. max L represents the maximum allowable stress of the valve plate material, in MPa. p D is the pitch, in mm; smin This refers to the major diameter / nominal diameter of the external thread, in mm; K nmax is the minor diameter of the internal thread, in mm; f is the allowable stress of the valve plate material, in MPa;

[0020] S7: Simulation CAE analysis, verification passed;

[0021] S8: The valve plate supplier and the tool supplier urgently designed new tools, urgently procured new tools, and urgently processed valve plate prototypes;

[0022] S9: Samples were assembled from incoming materials, and 3 samples were randomly inspected and disassembled without any abnormalities; the rest were used for durability testing.

[0023] S10: The test verification in step S9 is completed without any abnormalities; the conditions for formal switching are met.

[0024] In a preferred embodiment, the sketching in step S1 requires marking the dimensions of the sample, and using existing conventional drawings as a base and providing conventional drawings, marking specific improvement points and providing detailed enlarged views for key marking.

[0025] In a preferred embodiment, the verification method in step S2 is verified by a tightening test of the accumulator: the valve plate is reduced by two turns in the threaded hole of the accumulator, the accumulator is manually tightened to the accumulator sealing ring, and after tightening with an electric tightening gun, the accumulator is disassembled with a manual wrench, and it is observed whether aluminum shavings are generated at the thread of the accumulator and the valve plate.

[0026] In a preferred embodiment, the arrangement technology switching plan in step S3 is to rearrange the row numbers based on the verification results in step S2, and to arrange the data using the detection data as sub-items.

[0027] In a preferred embodiment, the 3D assembly inspection in step S4 involves assembling the 3D assembly parts and inspecting and comparing the appearance and data of the assembly.

[0028] In a preferred embodiment, the dimension chain mentioned in step S5 is a dimension ratio established by the height, width, and inner and outer diameter of the hole of a single-size assembly, so that the dimension chain can be adapted when the size of the assembly changes.

[0029] In a preferred embodiment, step S7 involves using simulation CAE analysis to calculate and analyze the strength, stiffness, buckling stability, dynamic response, heat conduction, three-dimensional multibody contact, and elastoplastic mechanical properties of complex engineering and product structures, as well as to provide an approximate numerical value for structural performance optimization design problems.

[0030] In a preferred embodiment, the durability test in step S9 is a test conducted to determine the service life of the product under specified use and maintenance conditions, and to predict or verify weak points and dangerous parts of the structure.

[0031] The technical effects and advantages of this invention are as follows:

[0032] This invention utilizes a newly designed internal thread structure, removing two internal threads from the bottom of the valve plate to avoid exposing two threads at the accumulator head. First, physical assembly verification yielded satisfactory results, showing no aluminum chips during screwing in and out. Then, it entered the formal design change process, undergoing verification and approval using 3D verification and CAE analysis. Finally, module-level durability testing was conducted, successfully passing vibration and charge / discharge pressure durability tests. In summary, this new design has passed design and assembly verification and is ready for mass production. Detailed Implementation

[0033] The technical solutions of the present invention will be clearly and completely described below with reference to 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 of ordinary skill in the art without creative effort are within the scope of protection of the present invention.

[0034] In response to the technical problems raised in the background art, the inventors, through analysis, discovered that when the high-voltage accumulator is screwed into the upper valve plate, the two parts have different hardnesses, and the external thread can easily cut the internal thread, producing aluminum wire, which then enters the main oil circuit, contaminating the solenoid valve, posing a significant risk.

[0035] The first and second threads of the accumulator's external thread head are guide threads, with their tooth profile gradually transitioning from none to one, including a portion of incomplete threads; when tightened with 150 Nm (a large torque), this portion of incomplete threads will produce a cutting effect.

[0036] During visits to relevant manufacturers in the industry, it was learned that competitors also had the same problem; therefore, it was determined that this type of internal and external thread cutting problem may be a common defect in this design.

[0037] It is important to emphasize that this design differs from the usual thread relief groove. While the relief groove reduces the risk of cutting during thread engagement, it also significantly reduces the wall thickness at the root of the valve plate's internal thread, posing a risk to the component's strength. This design, on the other hand, ensures that the thread engagement does not result in cutting and avoids the risk of insufficient strength due to excessively thin root thickness.

[0038] This invention provides a method for designing the internal thread of the accumulator connection in a high-pressure hydraulic control module. The specific design steps are as follows:

[0039] S1: Draw a 2D sketch and distribute it to the valve plate supplier to manufacture a temporary sample for assembly verification; the sketch should include dimensions of the sample and be based on existing standard drawings. Mark specific improvement points and provide detailed enlarged views for emphasis.

[0040] S2: After progressive detailed verification and adjustment, the design scheme is determined and assembled, verified and approved by the quality department personnel; the verification method is to use the accumulator tightening test: the accumulator is installed with two turns of valve plate in the threaded hole, the accumulator is manually tightened to the accumulator sealing ring, and after tightening with an electric tightening gun, the accumulator is disassembled with a manual wrench and it is observed whether aluminum shavings are generated at the threads of the accumulator and valve plate;

[0041] S3: Arrangement technology switching plan; The arrangement technology switching plan is to rearrange the row numbers based on the verification results in step S2, and arrange the data using the test data as the sub-items;

[0042] S4: Design formal 2D drawings and 3D models, and perform 3D assembly checks in parallel; 3D assembly checks involve assembling 3D assemblies and checking and comparing the appearance and data of the assembly.

[0043] S5. Dimension chain verification: The dimension chain is a dimensional ratio established by the height, width, and inner and outer diameter of the holes of a single-dimensional assembly, so that the dimensional chain can be adapted when the size of the assembly changes.

[0044] Internal verification of the module passed: verification of the module's own dimensional proportions and dimensional chain;

[0045] Customer's gearbox end verification passed: ensuring that the assembly dimension chain between the module and the gearbox mating level remains unchanged and has been verified;

[0046] S6: Perform threaded connection strength verification, supported by the accumulator supplier;

[0047] Thread connection length verification: The given thread length calculation formula is as follows:

[0048] and

[0049] calculate:

[0050]

[0051] in conclusion:

[0052]

[0053] Among them, f shmax D represents the maximum allowable shear stress of the valve plate material, in MPa. i The valve plate inner diameter is in mm; PS is the accumulator's maximum design operating pressure in MPa; L e E represents the thread length in mm. smin f is the pitch diameter of the internal thread, in mm; sh f represents the allowable shear stress of the valve plate material, in MPa. max L represents the maximum allowable stress of the valve plate material, in MPa. p D is the pitch, in mm; smin This refers to the major diameter / nominal diameter of the external thread, in mm; K nmax is the minor diameter of the internal thread, in mm; f is the allowable stress of the valve plate material, in MPa;

[0054] Specifically, let's take actual experimental data as an example:

[0055] The parameters for checking the threaded connection length are as follows:

[0056] PS = 7 MPa;

[0057] D i =65.7mm;

[0058] D smin =68mm;

[0059] L p =1.5mm;

[0060] L e =14mm;

[0061] E smin =66.54mm;

[0062] f sh =85.33MPa;

[0063] K nmax =65.56mm;

[0064] f = 106.7 MPa;

[0065] Calculate the above parameters to obtain f. shmax =16.22MPa; f max = 9.952 MPa;

[0066] Therefore, it can be concluded that the strength test passed;

[0067] S7: Simulation CAE analysis, verification passed; Simulation CAE analysis is an approximate numerical method used by computers to solve complex engineering and product structures for strength, stiffness, buckling stability, dynamic response, heat conduction, three-dimensional multibody contact, elastoplastic mechanical properties, and structural performance optimization design problems.

[0068] S8: The valve plate supplier and the tool supplier urgently designed new tools, urgently procured new tools, and urgently processed valve plate prototypes;

[0069] S9: Sample parts are assembled from incoming materials, and 3 are randomly selected for disassembly and no abnormalities are found; the rest are used for durability testing and verification; durability testing is a test conducted to determine the service life of a product under specified use and maintenance conditions, and to predict or verify weak points and dangerous parts of the structure.

[0070] S10: The test verification in step S9 is completed without any abnormalities; the conditions for formal switching are met.

[0071] In summary, the following table contains the data:

[0072] Inner diameter of the inner groove none Ф69.4~69.6 Avoid 2 turns of the external thread head of the accumulator Thread length 24.4～24.6 21.4～21.6 Remove 2 turns of internal thread Bottom rounded corners R2~R2.5 R1.75~R2.25 Reduce stress concentration

[0073] By redesigning the internal thread structure, two internal threads were removed from the bottom of the valve plate to avoid the two threads on the accumulator head. First, the physical assembly was used for verification, and satisfactory results were obtained, namely, no aluminum chips were found when screwing in and out. Then, the formal design change process was initiated, and verification and approval were carried out using simulation methods such as 3D verification and CAE analysis. Finally, the module's individual durability test was used for verification, and it successfully passed the vibration test and the charge and discharge pressure durability test.

[0074] In conclusion, the above description is only a preferred embodiment of the present invention and is not intended to limit the present invention. Any modifications, equivalent substitutions, improvements, etc., made within the spirit and principles of the present invention should be included within the protection scope of the present invention.

Claims

1. A method for designing the internal thread connection of an accumulator in a high-pressure hydraulic control module, characterized in that: The specific design steps are as follows: S1: Draw a 2D sketch and send it to the valve plate supplier to manufacture a temporary prototype for assembly verification; S2: After progressive detailed verification and adjustment, the design scheme was determined and verified by the quality department personnel through a tightening test of the accumulator: the accumulator mounting thread hole was missing two turns of the valve plate, the accumulator was manually tightened to the accumulator sealing ring, and after tightening with an electric tightening gun, the accumulator was disassembled with a manual wrench to observe whether aluminum shavings were generated at the threads of the accumulator and the valve plate. S3: Alignment technology switching plan; S4: Design formal 2D drawings and 3D models, and perform 3D assembly checks in parallel; S5, Dimension Chain Verification; Internal verification of the module passed: verification of the module's own dimensional proportions and dimensional chain; Customer's gearbox end verification passed: ensuring that the assembly dimension chain between the module and the gearbox mating level remains unchanged and has been verified; S6: Perform threaded connection strength verification; Thread connection length verification: The given thread length calculation formula is as follows: and ; calculate: in conclusion: in, The maximum allowable shear stress of the valve plate material is expressed in MPa. This refers to the inner diameter of the valve plate, in mm. This refers to the maximum design operating pressure of the accumulator, expressed in MPa. This refers to the thread length, in mm. This is the pitch diameter of the internal thread, in mm. This represents the allowable shear stress of the valve plate material, in MPa. This represents the maximum allowable stress of the valve plate material, in MPa. The pitch is in mm; This is the major diameter / nominal diameter of the external thread, in mm. This is the minor diameter of the internal thread, in mm. This represents the allowable stress of the valve plate material, in MPa. S7: Simulation CAE analysis, verification passed; S8: The valve plate supplier and the tool supplier urgently designed new tools, urgently procured new tools, and urgently processed valve plate prototypes; S9: Samples were assembled from incoming materials, and 3 samples were randomly inspected and disassembled without any abnormalities; the rest were used for durability testing. S10: The test verification in step S9 is completed without any abnormalities; the conditions for formal switching are met.

2. The design method for the internal thread connection of the accumulator in the high-pressure hydraulic control module according to claim 1, characterized in that: In step S1, the sketch needs to be marked with the dimensions of the sample, and the existing conventional drawings should be used as the base version and conventional drawings should be provided. Specific improvement points should be marked and accompanied by detailed enlarged drawings for key marking.

3. The design method for the internal thread connection of the accumulator in the high-pressure hydraulic control module according to claim 1, characterized in that: The arrangement technology switching plan in step S3 is to rearrange the row numbers based on the verification results in step S2, and to arrange the data using the detection data as sub-items.

4. The design method for the internal thread connection of the accumulator in the high-pressure hydraulic control module according to claim 1, characterized in that: In step S4, the 3D assembly inspection involves assembling the 3D assemblies and inspecting and comparing the appearance and data of the assembly.

5. The design method for the internal thread connection of the accumulator in the high-pressure hydraulic control module according to claim 1, characterized in that: The dimension chain mentioned in step S5 is a dimension ratio established by the height, width, and inner and outer diameter of the hole of a single-size assembly, so that the dimension chain can be adapted when the size of the assembly changes.

6. The design method for the internal thread connection of the accumulator in the high-pressure hydraulic control module according to claim 1, characterized in that: In step S7, the simulation CAE analysis is an approximate numerical value used to analyze and calculate the strength, stiffness, buckling stability, dynamic response, heat conduction, three-dimensional multibody contact, and elastoplastic mechanical properties of complex engineering and product structures, as well as the optimization design problem of structural performance.

7. The design method for the internal thread connection of the accumulator in the high-pressure hydraulic control module according to claim 1, characterized in that: The durability test in step S9 is a test conducted to determine the service life of the product under specified use and maintenance conditions, and to predict or verify weak points and dangerous parts of the structure.

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