A method for machining a high-precision, low-rigidity lever assembly.

Abstract

This invention belongs to the field of lever machining technology, specifically relating to a machining method for a high-precision, weakly rigid lever assembly. The invention completes the machining of the weakly rigid lever assembly through six steps: heat treatment of the raw materials of the lever and shaft, preparation of a process table, individual machining of the lever and shaft, assembly of the lever and shaft, fine finishing of the reference surface, machining of the assembly, and removal of the process table. This invention not only significantly reduces the precision and difficulty of individual part machining and improves measurement accuracy, but also achieves economical machining precision, reducing machining costs. This invention effectively solves the deformation problem of parts during machining, ensuring stable machining quality and improving the pass rate and machining efficiency. This invention effectively solves the deformation problem of parts caused by poor rigidity or unbalanced force, meeting the requirements of geometric tolerances. This invention is applicable to the machining of other high-precision, weakly rigid assemblies and has a wide range of applications.

Description

Technical Field

[0001] This invention belongs to the field of lever processing technology, specifically relating to a processing method for a high-precision, low-rigidity lever assembly. Background Technology

[0002] A lever is a common component that, when combined with a shaft or other parts, enables functions such as switching, changing direction, and changing speed. Due to its simple structure and low processing cost, it is widely used in industries such as electrical appliances, automobiles, and military.

[0003] Currently, the following two methods are used for machining lever assemblies:

[0004] The first method involves processing the components as a whole, resulting in complex workpiece shapes, low material utilization, long processing cycles, and high processing costs. It is not suitable for mass production and is not commonly used in actual production.

[0005] The second method involves machining the lever and shaft individually to their final dimensions and then assembling them together using an interference fit. This method is relatively common, but for assemblies with high precision requirements and poor rigidity, it significantly increases the precision requirements for machining the individual lever and shaft, making individual machining more difficult. Due to the poor rigidity, they are prone to deformation, making it difficult to guarantee precision during machining. Furthermore, as precision increases, the accuracy of measurement relatively decreases. Secondly, during the assembly of the lever and shaft, due to poor rigidity or unbalanced applied forces, the parts are prone to deformation, and the form and position tolerances cannot meet the requirements, resulting in the scrapping of the parts.

[0006] It is evident that current processing methods cannot meet the processing requirements of high-precision, low-rigidity lever assemblies, and an efficient processing method is urgently needed. Summary of the Invention

[0007] To address the aforementioned technical problems, this invention provides a method for machining a high-precision, weakly rigid lever assembly.

[0008] To achieve the above objectives, the technical solution adopted by the present invention is as follows:

[0009] A method for machining a high-precision, weakly rigid lever assembly includes the following steps:

[0010] Step 1: Heat treatment of the raw materials for the lever and shaft;

[0011] Step 2: Reserve the process table and perform individual machining on the lever and shaft respectively;

[0012] Step 3: Assemble the lever and shaft;

[0013] Step 4: Refine the reference surface;

[0014] Step 5: Assembly of components.

[0015] In step one, the raw materials of the lever and shaft undergo heat treatment to achieve a Rockwell hardness of HRC28-32.

[0016] The individual processing of the lever includes the following steps:

[0017] S1. Rough machining of the lever;

[0018] Leave a process table at the bottom of the small hole on the lever. The process table is placed at the bottom of the small hole on the lever and close to the edge of the small hole. The upper surface of the process table is at the same height as the lower surface, front side and rear side of the lever. During processing, leave a margin of 0.8 to 1 mm for the large hole, small hole and reference surface, and process the remaining parts to the design size.

[0019] S2, lever stabilization treatment;

[0020] Perform three hot and cold cycles on the lever;

[0021] S3, semi-finished lever.

[0022] The operation method for stabilizing the lever is as follows: cool to -55±5℃, keep warm for 2±0.2h, air cool to room temperature and keep warm for more than 1.5h, then heat to 90±10℃, keep warm for 3±0.2h, air cool to room temperature and keep warm for more than 1.5h.

[0023] The semi-finishing of the lever is carried out by boring the large and small holes in one clamping operation. During the machining, the datum surface is left with a margin of less than 0.05 mm, the large hole of the lever is left with a margin of 0.3 to 0.4 mm, the small hole is machined to size, the parallelism of the two holes is controlled within 0.02 to 0.03 mm, and the surface roughness Ra of the small hole is ≤1.6 μm. The number of tool passes during boring is not less than 3.

[0024] The operation method for machining a single piece of the shaft is as follows: the end that mates with the small hole is machined to the specified size, and the other end is left with a allowance of 0.2 to 0.3 mm. The surface roughness Ra of the end that mates with the small hole is ≤ 1.6 μm.

[0025] The specific method for combining the lever and shaft in step three is to insert the shaft into the small hole of the lever. The small hole and the shaft are interference fit, with an interference amount of 0.015 to 0.031 mm. The deviation of the shaft is no more than 0.1 mm. When inserting the shaft into the small hole, a pressing device is used to press it in at a uniform speed of 1 to 2 mm / s.

[0026] The pressing device includes a small vise, a support block, and a directional sleeve; during assembly, the support block and the directional sleeve are placed opposite each other in the jaws of the small vise, and the shaft is inserted into the directional sleeve; one end of the lever with a small hole overlaps the support block, and the small hole is aligned with the shaft.

[0027] The method for refining the reference surface in step four is grinding, with a flatness within 0.005mm; the plate used for grinding has a precision of no less than grade 1.

[0028] The specific method for machining the assembly in step five is to complete the boring of the large hole and shaft in one clamping operation; the large hole and shaft are machined to the required dimensions, with the spacing tolerance within ±0.01mm, the parallelism within 0.015mm, and the surface roughness Ra≤1.6μm; the boring head used during boring includes a boring tool and a connecting head, and the front end of the boring tool is provided with a tool head in the shape of an obtuse triangle; the boring tool and the connecting head are detachably connected.

[0029] Beneficial effects:

[0030] (1) This invention completes the machining of a high-precision, weakly rigid lever assembly through six steps: heat treatment of the raw materials of the lever and shaft, preparation of the process table, individual machining of the lever and shaft, assembly of the lever and shaft, fine finishing of the reference surface, machining of the assembly, and removal of the process table. This invention not only significantly reduces the precision and difficulty of individual part machining and improves the accuracy of measurement, but also achieves economical machining precision and reduces machining costs.

[0031] (2) By employing reasonable processing procedures, precise control of allowances, intermediate stabilization treatment, and strict control of processing links, this invention effectively solves the problem of deformation of parts during processing, ensuring stable processing quality and improving the pass rate and processing efficiency.

[0032] (3) The process table retained by the present invention not only improves the positioning accuracy and increases the rigidity of the parts, but also facilitates clamping.

[0033] (4) The boring method used in this invention for holes and shafts significantly improves the machining quality. The boring tool used has a simple structure, is easy to manufacture, and significantly improves the machining efficiency.

[0034] (5) The pressing method and device used in this invention effectively solve the problem of part deformation caused by poor rigidity or unbalanced force, meet the form and position tolerance requirements, and improve the efficiency and pass rate of assembly.

[0035] (6) This invention is applicable to the processing of other high-precision weak rigidity assemblies and has a wide range of applications.

[0036] The above description is merely an overview of the technical solution of the present invention. In order to better understand the technical means of the present invention and to implement it in accordance with the contents of the specification, the preferred embodiments of the present invention are described in detail below with reference to the accompanying drawings. Attached Figure Description

[0037] To more clearly illustrate the technical solutions in the embodiments of the present invention or the prior art, the drawings used in the embodiments will be briefly introduced below. Obviously, the drawings described below are only some embodiments of the present invention. For those skilled in the art, other drawings can be obtained based on these drawings without creative effort.

[0038] Figure 1 This is a flowchart of the processing of the present invention.

[0039] Figure 2 This is a cross-sectional view of the lever assembly in this invention.

[0040] Figure 3 This is a top view of the lever assembly in this invention.

[0041] Figure 4 A sectional view is taken of the process table for the lever component in this invention.

[0042] Figure 5 A top view is provided for the process table of the lever component in this invention.

[0043] Figure 6 This is a schematic diagram of the assembly of the present invention.

[0044] Figure 7 This is a schematic diagram of the boring tool in this invention.

[0045] In the diagram: 1. lever; 2. shaft; 3. process table; 4. small vise; 5. support block; 6. directional sleeve; 7. boring tool; 8. connector; 9. large hole; 10. small hole; 11. cutting head. Detailed Implementation

[0046] The technical solutions of the embodiments of the present invention will be clearly and completely described below with reference to the accompanying drawings. Obviously, the described embodiments are only a part of the embodiments of the present invention, and not all of the 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.

[0047] Example 1:

[0048] according to Figures 1-7 The method for machining a high-precision, weakly rigid lever assembly, as shown, includes the following steps:

[0049] Step 1: Heat treatment is performed on the raw materials of lever 1 and shaft 2;

[0050] Step 2: Take process table 3 and perform individual machining on lever 1 and shaft 2 respectively;

[0051] Step 3: Assemble lever 1 and shaft 2;

[0052] Step 4: Refine the reference surface;

[0053] Step 5: Assembly of components;

[0054] Step 6: Remove process table 3.

[0055] This invention completes the machining of a high-precision, low-rigidity lever assembly through six steps: heat treatment of the raw materials of lever 1 and shaft 2; preparation of the process table 3; individual machining of lever 1 and shaft 2; assembly of lever 1 and shaft 2; fine finishing of the reference surface; machining of the assembled assembly; and removal of the process table. By employing a reasonable machining process, this invention not only significantly reduces the precision and difficulty of individual part machining and improves measurement accuracy, but also achieves economical machining precision, reducing processing costs.

[0056] This invention is applicable to the machining of other high-precision, low-rigidity assemblies and has a wide range of applications.

[0057] Example 2:

[0058] according to Figures 1-6 The processing method of a high-precision weak rigidity lever assembly shown differs from that of Embodiment 1 in that: in step one, the raw materials of lever 1 and shaft 2 are heat-treated to achieve a Rockwell hardness of HRC28-32.

[0059] In practical use, by heat-treating the raw materials of lever 1 and shaft 2, the rigidity of the parts is increased, effectively solving the problem of deformation of the parts during processing, ensuring stable processing quality, and improving the pass rate and processing efficiency.

[0060] Example 3:

[0061] according to Figures 1-7 The processing method of the high-precision weak rigidity lever assembly shown differs from that of Embodiment 1 in that the single-piece processing of the lever 1 includes the following steps:

[0062] S1, Rough machining of lever 1;

[0063] A process platform 3 is left at the lower part of the small hole 10 of the lever 1. The process platform 3 is placed at the lower end of the small hole 10 on the lever 1 and is close to the edge of the small hole 10. The upper surface of the process platform 3 is at the same height as the lower surface, front side and rear side of the lever 1. During processing, the allowance of the large hole 9, the small hole 10 and the reference surface is 0.8 to 1 mm, and the remaining parts are processed to the design size.

[0064] S2, Stabilization treatment of lever 1;

[0065] Perform three hot and cold cycles on lever 1;

[0066] S3, lever 1 half-finished.

[0067] Furthermore, the stabilization process for the lever 1 is as follows: cool to -55±5℃, keep warm for 2±0.2h, air cool to room temperature and keep warm for more than 1.5h, then heat to 90±10℃, keep warm for 3±0.2h, and air cool to room temperature and keep warm for more than 1.5h.

[0068] Furthermore, the semi-finishing of the lever 1 is carried out by boring the large hole 9 and the small hole 10 in one clamping; during machining, the datum surface is left with a allowance of less than 0.05mm, the large hole 9 of the lever 1 is left with a allowance of 0.3 to 0.4mm, the small hole 10 is machined to size, the parallelism of the two holes is controlled within 0.02 to 0.03mm, and the surface roughness Ra of the small hole 10 is ≤1.6μm; the number of tool passes during boring is not less than 3.

[0069] In practical use, this invention improves the stability of processing quality, increases the pass rate and processing efficiency through measures such as intermediate stabilization treatment and strict control of processing steps.

[0070] Example 4:

[0071] according to Figures 1-3 , Figure 6 and Figure 7 The processing method of the high-precision weak rigidity lever assembly shown is different from that of Embodiment 1 in that: the single-piece processing method of the shaft 2 is as follows: the end that mates with the small hole 10 is processed to the specified size, and the other end is left with a margin of 0.2 to 0.3 mm. The surface roughness Ra of the end that mates with the small hole 10 is ≤ 1.6 μm.

[0072] In practical use, the adoption of this technical solution allows for precise control of the allowance, improving positioning accuracy and facilitating clamping.

[0073] Example 5:

[0074] according to Figures 1-7 The processing method of the high-precision weak rigidity lever assembly shown differs from that of Embodiment 1 in that: the specific method of assembling the lever 1 and the shaft 2 in step three is to insert the shaft 2 into the small hole 10 of the lever 1, the small hole 10 and the shaft 2 are interference fit, the interference amount is 0.015~0.031mm, and the deviation of the shaft 2 is not greater than 0.1mm; when the shaft 2 is inserted into the small hole 10, it is pressed in at a uniform speed using a pressing device, the pressing speed is 1~2mm / s.

[0075] Furthermore, the pressing device includes a small vise 4, a support block 5, and a directional sleeve 6; during assembly, the support block 5 and the directional sleeve 6 are placed opposite each other in the jaws of the small vise 4, and the shaft 2 is inserted into the directional sleeve 6; one end of the lever 1 with a small hole 10 is attached to the support block 5, and the small hole 10 is aligned with the shaft 2.

[0076] In practical use, the pressing method and pressing device adopted in this invention effectively solve the problem of part deformation caused by poor rigidity or unbalanced force, meet the form and position tolerance requirements, and improve the efficiency and pass rate of assembly.

[0077] Example 6:

[0078] according to Figures 1-7 The processing method of the high-precision weak rigidity lever assembly shown differs from that of Embodiment 1 in that the method of fine-tuning the reference surface in step four is grinding, with a flatness within 0.005mm; the plate used for grinding has a precision of not less than grade 1.

[0079] In practical use, the above-mentioned technical solution is easy to implement for refining the reference surface, and it also ensures the machining quality of the lever assembly.

[0080] Example 7:

[0081] according to Figures 1-7 The processing method of the high-precision weak rigidity lever assembly shown differs from that of Embodiment 1 in that: the specific method for processing the assembly in step five is to complete the boring of the large hole 9 and the shaft 2 in one clamping; the large hole 9 and the shaft 2 are processed to the required dimensions, the distance tolerance between the large hole 9 and the shaft 2 is within ±0.01mm, the parallelism is within 0.015mm, and the surface roughness Ra≤1.6μm; the boring head used during boring includes a boring tool 7 and a connecting head 8, the front end of the boring tool 7 is provided with a tool head 11 in the shape of an obtuse triangle; the boring tool 7 and the connecting head 8 are detachably connected.

[0082] The boring method used in this invention for large holes and shaft 2 significantly improves machining quality.

[0083] The boring tool used has a simple structure, good rigidity, low manufacturing cost, and convenient connection. It can be used not only in external diameter boring, but its structure can also be applied to boring and chamfering of hole openings, making it widely applicable.

[0084] The boring head using the above technical solution is not only easy to operate and produces better boring quality, but also significantly improves processing efficiency.

[0085] Example 8:

[0086] according to Figures 1-7The processing method of the high-precision weak rigidity lever assembly shown differs from that of Embodiment 1 in that the width of the process table 3 is 8-10mm, preferably 9mm.

[0087] The above-mentioned technical solution is adopted for process table 3, which not only improves the positioning accuracy, but also facilitates clamping.

[0088] Where there is no conflict, those skilled in the art can combine the relevant technical features in the above examples according to the actual situation to achieve the corresponding technical effects. Specific details of the various combinations will not be elaborated here.

[0089] It should be noted that all directional indications (such as up, down, left, right, front, back, etc.) in the embodiments of the present invention are only used to explain the relative positional relationship and movement of each component in a certain specific posture (as shown in the figure). If the specific posture changes, the directional indication will also change accordingly.

[0090] Furthermore, the use of terms such as "first" and "second" in this invention is for descriptive purposes only and should not be construed as indicating or implying their relative importance or implicitly specifying the number of technical features indicated. Therefore, a feature defined with "first" or "second" may explicitly or implicitly include at least one of those features.

[0091] The above description is merely a preferred embodiment of the present invention. The present invention is not limited to the embodiments shown herein, but is to be accorded the widest scope consistent with the principles and novel features disclosed herein. Any simple modifications, equivalent variations, and alterations made to the above embodiments based on the technical essence of the present invention shall still fall within the scope of the present invention.

Claims

1. A method of machining a high-precision weak-rigid pushrod assembly, characterized by: It comprises the following steps, Step one: quenching and tempering treatment of raw materials of the lever (1) and the shaft (2); Step two: process platform is left, and the lever (1) and the shaft (2) are respectively processed as single pieces; The single piece processing of the lever (1) comprises the following steps, S1, rough machining of the lever (1); A process platform (3) is left at the lower part of the small hole (10) of the lever (1), the process platform (3) is arranged at the lower end of the small hole (10) of the lever (1) and is close to the edge of the small hole (10), the upper surface of the process platform (3) is level with the lower surface, the front side and the rear side of the lever (1); during processing, the remaining amount of the large hole (9), the small hole (10) and the reference surface is 0.8-1mm, and the remaining parts are processed to the design size; S2, stabilization treatment of the lever (1); Three cold and hot cycles are performed on the lever (1); S3, semi-finishing machining of the lever (1); The operation method of the stabilization treatment of the lever (1) is that the lever (1) is cooled to-55±5℃, kept for 2±0.2h, air-cooled to room temperature for more than 1.5h, then heated to 90±10℃, kept for 3±0.2h, and air-cooled to room temperature for more than 1.5h; The semi-finishing machining of the lever (1) is completed by one-time clamping of the boring machining of the large hole (9) and the small hole (10); during processing, the reference surface is left with a remaining amount of 0.05mm or less, the large hole (9) of the lever (1) is left with a remaining amount of 0.3-0.4mm, the small hole (10) is processed to the size, the parallelism of the two holes is controlled to be within 0.02-0.03mm, and the surface roughness Ra of the small hole (10) is ≤1.6μm; the boring machining is performed for not less than 3 times of tool walking; Step three: combination of the lever (1) and the shaft (2); Step four: finishing of the reference surface; Step five: processing of the combined piece; Step six: removal of the process platform (3).

2. The processing method of a high-precision weakly rigid lever assembly as described in claim 1, characterized in that: The quenching and tempering treatment of the raw materials of the lever (1) and the shaft (2) in step one makes the Rockwell hardness of the materials of the lever (1) and the shaft (2) reach HRC28-32.

3. The processing method of a high-precision weakly rigid lever assembly as described in claim 1, characterized in that: The operation method of the single piece processing of the shaft (2) is that the end matched with the small hole (10) is processed to the size, and the other end is left with a remaining amount of 0.2-0.3mm, and the surface roughness Ra of the end matched with the small hole (10) is ≤1.6μm.

4. The processing method of a high-precision weakly rigid lever assembly as described in claim 1, characterized in that: The specific method of the combination of the lever (1) and the shaft (2) in step three is that the shaft (2) is inserted into the small hole (10) of the lever (1), the small hole (10) is in interference fit with the shaft (2), the interference amount is 0.015-0.031mm, and the deviation amount of the shaft (2) is not more than 0.1mm; when the shaft (2) is inserted into the small hole (10), the uniform speed pressing device is used for uniform speed pressing, and the pressing speed is 1-2mm / s.

5. The processing method of a high-precision weakly rigid lever assembly as described in claim 4, characterized in that: The pressing device comprises a small vice (4), a supporting block (5) and a directional sleeve (6); during assembly, the supporting block (5) and the directional sleeve (6) are oppositely arranged in the jaw of the small vice (4), and the shaft (2) is inserted into the directional sleeve (6); one end of the lever (1) provided with the small hole (10) is overlapped on the supporting block (5), and the small hole (10) is directly opposite to the shaft (2).

6. The processing method of a high-precision weakly rigid lever assembly as described in claim 1, characterized in that: The method of finishing the reference surface in step four is grinding processing, and the flatness is within 0.005mm; the flat plate used for grinding processing has a precision of not less than 1 level.

7. The processing method of a high-precision weakly rigid lever assembly as described in claim 1, characterized in that: The specific method of the assembly processing in the fifth step is to complete the boring processing of the large hole (9) and the shaft (2) in one clamping; the large hole (9) and the shaft (2) are processed to sizes, the spacing size tolerance of the large hole (9) and the shaft (2) is within ±0.01mm, the parallelism is within 0.015mm, and the surface roughness Ra is less than or equal to 1.6μm; the boring head used in the boring process comprises a boring cutter (7) and a connecting head (8), the front end of the boring cutter (7) is provided with a obtuse triangle-shaped cutter head (11); the boring cutter (7) is detachably connected with the connecting head (8).

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