Machining method for weak-rigidity thin-wall transmission positioning connecting plate

Abstract

The invention relates to a machining method for a weak-rigidity thin-wall transmission positioning connecting plate. The machining method comprises the steps that S1, a blank is machined; s2, a drilling process; s3, shape finish milling is conducted, specifically, the shape and the inner cavity outline are formed through finish milling with the auxiliary hole as the positioning reference; S4, aging treatment is conducted; s5, semi-finish machining is carried out, the upper plane and the lower plane of the body plate are finely ground, and the thickness size of the weak-rigidity thin-wall transmission positioning connecting plate is guaranteed; s6, vibration aging is conducted, vibration aging is conducted with the assistance of a clamp, internal residual stress is gradually released and evenly distributed under the vibration effect, and the product size and the mechanical property are further stabilized; and S7, the idler shaft mounting plane is milled, and a through hole, a concentric counter bore and a positioning pin hole in the idler shaft mounting plane are drilled / bored. According to the machining method for the weak-rigidity thin-wall transmission positioning connecting plate, low-temperature aging and vibration aging are carried out in batches in the manufacturing process, residual stress is effectively released, thin-wall deformation of products is controlled, the percent of pass is increased, and cost is reduced.

Description

Technical Field

[0001] This invention relates to the field of machining technology, and more specifically, to a machining method for a thin-walled transmission positioning connecting plate with low stiffness. Background Technology

[0002] The thin-walled transmission positioning connecting plate with low stiffness, which is installed on the lightweight, high-power-density engine alloy housing, is a "bridge" connecting the idler shaft and the housing, and also a "precise anchor point" in the assembly process. It plays an important role in efficient power regulation during engine transmission, and together ensures the stability and reliability of the idler transmission. The reliability of its connection is directly related to the engine's power performance and safety.

[0003] Currently, the main technical drawback of the processing scheme for thin-walled transmission positioning connecting plates with low stiffness is that: first, machining (including semi-finish boring and finish milling of the outer shape) is performed, followed by heat treatment (hardness ≤28HRC), leveling, rough / finish grinding, and then finish boring using the outer contour as the positioning datum. The thin-walled plate undergoes significant deformation after heat treatment, requiring repeated grinding. After inspection, its dimensional and geometric tolerances fail to meet the technical requirements of the overall machine assembly process, resulting in low product processing efficiency and yield, poor manufacturing quality stability, and severely slowing down production schedules.

[0004] Due to the numerous technical requirements of the low-stiffness thin-walled transmission positioning connecting plate, such as hardness ≤28HRC, high dimensional accuracy and geometric tolerance requirements, wall thickness <5mm, and high surface roughness requirements, the yield rate of its processing is extremely low. Not only is the dimensional stability of the product poor during processing, but deformation is also difficult to control, making it difficult to guarantee various geometric tolerances. This, in turn, affects the accuracy of the assembly and connection with the idler shaft and housing, resulting in differences in the torque distribution and fatigue strength of the transmission assembly. In severe cases, it can cause the idler shaft to loosen or shift under stress, posing a great safety hazard.

[0005] Therefore, there is an urgent need to develop a processing method for thin-walled transmission positioning connecting plates with low stiffness in order to improve the product qualification rate, reduce product manufacturing costs, and reduce safety hazards. Summary of the Invention

[0006] The technical problem to be solved by this invention is that the thin-walled transmission positioning connecting plate with low stiffness has large deformation during processing, resulting in low product processing efficiency and yield, and poor manufacturing quality stability.

[0007] To solve the above technical problems, the present invention provides a processing method for a low-stiffness thin-walled transmission positioning connection plate, wherein the low-stiffness thin-walled transmission positioning connection plate includes an idler shaft mounting hole to be processed, positioning pin holes distributed at an angle, and inner and outer contours, wherein the thinnest part of the thin wall is 4.8mm, and the surface roughness requirement is Ra0.2. The processing method for the low-stiffness thin-walled transmission positioning connection plate includes the following steps: S1, blank processing: grinding the reference plane of the body plate; after the product is blanked and tempered, the upper and lower planes are rough ground to process the reference plane; then, the two planes are semi-finish ground; S2, drilling process holes: using the bottom plane of the low-stiffness thin-walled transmission positioning connection plate as a reference on the processing equipment, the two sides of the process hole to be processed are limited in the X and Y directions, and after clamping, the process hole is drilled; S3, finish milling the outer shape: using the process hole as a positioning reference, the outer shape and inner cavity contour are finish milled respectively, and then... Inspection; S4, Aging treatment, slow cooling in the furnace, requiring consideration of stress relief and dimensional stability; S5, Semi-finishing, precision grinding of the upper and lower planes of the body plate to ensure the thickness of the thin-walled transmission positioning connection plate with weak rigidity; S6, Vibration aging, using a fixture for vibration aging, gradually releasing and evenly distributing internal residual stress under vibration, further stabilizing product dimensions and mechanical properties; S7, Precision boring / reaming machining, including: milling the idler shaft mounting plane, drilling / boring through holes and concentric countersunk holes on the idler shaft mounting plane, and drilling / reaming the positioning pin holes on the idler shaft mounting plane.

[0008] According to an embodiment of the present invention, in the processing method for a thin-walled transmission positioning connection plate with low stiffness, step S7 may further include: expanding the process hole, using the positioning pin hole as the positioning reference, expanding the process hole to the size required by the process, and processing all concentric countersunk holes.

[0009] 3 According to an embodiment of the present invention, the processing method for the low-stiffness thin-walled transmission positioning connection plate further includes: step S8, surface treatment according to design requirements.

[0010] According to an embodiment of the present invention, in the processing method for a thin-walled transmission positioning connecting plate with low stiffness, in step S1, when the upper and lower planes are rough ground to form a reference surface, the parallelism of the upper and lower planes is set to ≤0.1mm, and a 0.3mm allowance is left for each of the upper and lower planes.

[0011] According to an embodiment of the present invention, in the processing method for a thin-walled transmission positioning connecting plate with low stiffness, in step S1, when the upper and lower planes are semi-finished, the parallelism of the upper and lower planes is set to ≤0.05mm, and the upper and lower planes are respectively left with a fine grinding allowance of 0.2mm.

[0012] According to an embodiment of the present invention, in the processing method for a thin-walled transmission positioning connecting plate with low stiffness, in step S4, the aging treatment can be low-temperature aging at 120-180°.

[0013] According to an embodiment of the present invention, in the processing method for a thin-walled transmission positioning connecting plate with low stiffness, in step S5, the parallelism of the upper and lower planes can be ≤0.03mm.

[0014] According to an embodiment of the present invention, in the processing method for a thin-walled transmission positioning connecting plate with low stiffness, in step S5, when processing the upper and lower planes, a high-precision surface grinder can be used for low-feed, high-frequency grinding.

[0015] According to an embodiment of the present invention, in the processing method for a low-stiffness thin-walled transmission positioning connection plate, in step S5, a "one-face two-pin" positioning reference can be adopted. After fine grinding a plane, the required stepped shape of the plane is finely milled, and the required through holes, positioning pin holes and threaded holes are processed on the bottom plate of the low-stiffness thin-walled transmission positioning connection plate body.

[0016] According to an embodiment of the present invention, in the processing method for a thin-walled transmission positioning connecting plate with low stiffness, in step S6, the vibration aging can be 30-60 minutes.

[0017] Compared with the prior art, the technical solution provided by the embodiments of the present invention can achieve at least the following beneficial effects:

[0018] The processing method for low-stiffness thin-walled transmission positioning connecting plates according to the present invention is applied to drilling process holes in machining, which makes the repeated positioning of the product in subsequent processing accurate, and the cumulative error during repeated clamping and processing is almost negligible. The size and form and position tolerance of the positioning pin hole of the product fully meet the design requirements of the process drawings. While effectively controlling the deformation generated during the product processing, it ensures the various process technical requirements of the product, reduces production costs, and improves the product qualification rate, providing a new research direction for the manufacturing process of low-stiffness thin-walled transmission positioning connecting plates.

[0019] According to the processing method of the thin-walled transmission positioning connecting plate of the present invention, the machining process is supplemented by low temperature aging and vibration aging, which releases the processing stress and can effectively control the thin-wall deformation. In particular, the low temperature aging and vibration aging are carried out in stages during the manufacturing process, which effectively releases the residual stress, controls the thin-wall deformation of the product, improves the pass rate of various form and position tolerance inspections such as flatness and parallelism to more than 95%, and significantly reduces the manufacturing cost. Attached Figure Description

[0020] To more clearly illustrate the technical solutions of the embodiments of the present invention, the accompanying drawings of the embodiments will be briefly described below. Obviously, the drawings described below only relate to some embodiments of the present invention and are not intended to limit the present invention.

[0021] Figure 1This is a flowchart illustrating a processing method for a thin-walled transmission positioning connection plate with low stiffness according to an embodiment of the present invention;

[0022] Figure 2 This illustrates a thin-walled, low-stiffness transmission positioning connection plate blank body plate to be processed according to an embodiment of the present invention;

[0023] Figure 3a yes Figure 2 Top view after processing;

[0024] Figure 3b yes Figure 3a AA section view;

[0025] Figure 3c yes Figure 3a A bottom view;

[0026] Figures 4a-4b This is an example diagram illustrating a series of weak stiffness thin-walled transmission positioning connection plates to be processed according to an embodiment of the present invention. Detailed Implementation

[0027] To make the objectives, technical solutions, and advantages of the embodiments of the present invention clearer, 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 some, not all, of the embodiments of the present invention. Based on the described embodiments of the present invention, all other embodiments obtained by those skilled in the art without creative effort are within the scope of protection of the present invention.

[0028] Unless otherwise defined, the technical or scientific terms used herein shall have the ordinary meaning as understood by one of ordinary skill in the art to which this invention pertains. The terms “first,” “second,” and similar terms used in the specification and claims of this patent application do not indicate any order, quantity, or importance, but are merely used to distinguish different components. Similarly, the terms “an” or “a” and similar terms do not indicate a limitation of quantity, but rather indicate the presence of at least one.

[0029] Figure 1 This is a flowchart illustrating a processing method for a thin-walled transmission positioning connection plate with low stiffness according to an embodiment of the present invention; Figure 2 This illustrates a thin-walled, low-stiffness transmission positioning connection plate blank body plate to be processed according to an embodiment of the present invention; Figure 3a Figure 2 Top view after processing; Figure 3b yes Figure 3a AA section view; Figure 3c yes Figure 3a A bottom view.

[0030] like Figures 1 to 3cThe diagram illustrates a machining method for a thin-walled, low-stiffness transmission positioning connecting plate. The plate includes an idler shaft mounting hole to be machined, angularly distributed positioning pin holes, and inner and outer contours. The thinnest part of the wall is 4.8 mm, and the surface roughness requirement is Ra0.2.

[0031] The processing method for the thin-walled transmission positioning connection plate with low stiffness includes the following steps:

[0032] S1. Raw material processing: Grind the reference plane of the body plate; After the product is cut and tempered, rough grinding of the reference plane is performed on the upper and lower planes; then semi-finish grinding of the two planes is performed.

[0033] S2. Drill process hole 1. Using the bottom plane of the weak rigidity thin-walled transmission positioning connection plate as a reference on the processing equipment, limit the two sides of the process hole 1 to be processed in the X and Y directions. After the limit clamping, drill process hole 1.

[0034] S3. Fine mill the outer shape. Using process hole 1 as the positioning reference, fine mill the outer shape and inner cavity contour respectively, and inspect them.

[0035] S4. Aging treatment, slow cooling in the furnace, requires consideration of both stress relief and dimensional stability;

[0036] S5. Semi-finishing: Grind the upper and lower planes of the body plate to ensure the thickness of the thin-walled transmission positioning connection plate with weak rigidity.

[0037] S6. Vibration aging: Vibration aging is performed with the aid of a fixture. Under the action of vibration, the internal residual stress is gradually released and evenly distributed, which further stabilizes the product's dimensions and mechanical properties.

[0038] S7. Precision boring / reaming machining, including: milling the idler shaft mounting plane 4, drilling / boring the through hole 2 and concentric countersunk hole on the idler shaft mounting plane 4, and drilling / reaming the locating pin hole 5 on the idler shaft mounting plane 4.

[0039] According to the processing method of the thin-walled transmission positioning connecting plate of the present invention, the machining process is supplemented by low temperature aging and vibration aging, which releases the processing stress and can effectively control the thin-wall deformation. In particular, the low temperature aging and vibration aging are carried out in stages during the manufacturing process, which effectively releases the residual stress, controls the thin-wall deformation of the product, improves the pass rate of various form and position tolerance inspections such as flatness and parallelism to more than 95%, and significantly reduces the manufacturing cost.

[0040] According to one or more embodiments of the present invention, in the processing method for a thin-walled transmission positioning connection plate with low stiffness, step S7 further includes: expanding the process hole 1, using the positioning pin hole 5 as the positioning reference, expanding the process hole 1 to the size required by the process, and processing all concentric countersunk holes.

[0041] 3 According to one or more embodiments of the present invention, the processing method for the low stiffness thin-walled transmission positioning connection plate further includes: step S8, surface treatment according to design requirements.

[0042] According to one or more embodiments of the present invention, in the processing method for a thin-walled transmission positioning connecting plate with low stiffness, in step S1, when the upper and lower planes are rough ground to form a reference surface, the parallelism between the upper and lower planes is set to ≤0.1mm, and a 0.3mm allowance is left for each of the upper and lower planes.

[0043] According to one or more embodiments of the present invention, in the processing method for a thin-walled transmission positioning connecting plate with low stiffness, in step S1, when the upper and lower planes are semi-finished, the parallelism of the two planes is set to ≤0.05mm, and the upper and lower planes are respectively left with a fine grinding allowance of 0.2mm.

[0044] According to one or more embodiments of the present invention, in the processing method for a thin-walled transmission positioning connecting plate with low stiffness, in step S4, the aging treatment is low-temperature aging at 120-180°.

[0045] According to one or more embodiments of the present invention, in the processing method for a thin-walled transmission positioning connecting plate with low stiffness, in step S5, the parallelism of the upper and lower planes is ≤0.03mm.

[0046] According to one or more embodiments of the present invention, in the processing method for a thin-walled transmission positioning connecting plate with low stiffness, in step S5, when the upper and lower planes are processed, a high-precision surface grinder is used for low-feed high-frequency grinding.

[0047] According to one or more embodiments of the present invention, in the processing method for a low-stiffness thin-walled transmission positioning connection plate, in step S5, a "one-face two-pin" positioning reference is adopted, a plane is finely ground, and the required stepped shape of the plane is finely milled, and the required through hole 2, positioning pin hole 3 and threaded hole are processed on the bottom plate of the low-stiffness thin-walled transmission positioning connection plate body.

[0048] According to one or more embodiments of the present invention, in the processing method for a thin-walled transmission positioning connecting plate with low stiffness, in step S6, vibration aging is performed for 30-60 minutes.

[0049] The processing method for a low-stiffness thin-walled transmission positioning connecting plate according to the present invention is applied to drilling process holes 1 in machining, which makes the repeated positioning of the product in subsequent processing accurate, and the cumulative error during repeated clamping and processing is almost negligible. The size and form and position tolerance of the positioning pin hole of the product fully meet the design requirements of the process drawings. While effectively controlling the deformation generated during the product processing, it ensures the various process technical requirements of the product, reduces production costs, and improves the product qualification rate, providing a new research direction for the manufacturing process of low-stiffness thin-walled transmission positioning connecting plate products.

[0050] Figures 4a-4b This is an example diagram illustrating a series of weak stiffness thin-walled transmission positioning connection plates to be processed according to an embodiment of the present invention.

[0051] like Figures 4a-4b As shown, with the product design benchmark as a reference, a series of positioning plate products with a positioning hole center distance tolerance of ≤0.05mm, a hole perpendicularity to the plate reference surface of ≤0.03mm, and a parallelism of ≤0.03mm are machined to prevent deformation and ensure repeatability of positioning accuracy. This process can be used to locate and clamp the product with a fixture, and also ensures the consistency of the benchmark.

[0052] The above description is merely an exemplary embodiment of the present invention and is not intended to limit the scope of protection of the present invention, which is determined by the appended claims.

Claims

1. A method for machining a thin-walled transmission positioning connecting plate with low stiffness, wherein, The low-stiffness thin-walled transmission positioning connecting plate includes an idler shaft mounting hole to be machined, angularly distributed positioning pin holes, and inner and outer contours. The thinnest part of the wall is 4.8 mm, and the surface roughness requirement is Ra0.

2. The processing method for the thin-walled transmission positioning connection plate with low stiffness includes the following steps: S1. Raw material processing: Grind the reference plane of the body plate; After the product is cut and tempered, rough grinding of the reference plane is performed on the upper and lower planes; then semi-finish grinding of the two planes is performed. S2. Drilling process holes: Using the bottom plane of the weak rigidity thin-walled transmission positioning connection plate as a reference on the processing equipment, limit the two sides of the process hole to be processed in the X and Y directions. After the limit clamping, drill the process hole. S3. Precision milling of the outer shape: Using the process hole as the positioning reference, precision mill the outer shape and inner cavity contour respectively, and then inspect them. S4. Aging treatment, slow cooling in the furnace, requires consideration of both stress relief and dimensional stability; S5. Semi-finishing: Grind the upper and lower planes of the body plate to ensure the thickness of the thin-walled transmission positioning connection plate with weak rigidity. S6. Vibration aging: Vibration aging is performed with the aid of a fixture. Under the action of vibration, the internal residual stress is gradually released and evenly distributed, which further stabilizes the product's dimensions and mechanical properties. S7. Precision boring / reaming machining, including: milling the idler shaft mounting plane, drilling / boring through holes and concentric countersunk holes on the idler shaft mounting plane, and drilling / reaming locating pin holes on the idler shaft mounting plane.

2. The processing method for a thin-walled transmission positioning connecting plate with low stiffness as described in claim 1, wherein, Step S7 also includes: expanding the process hole, using the locating pin hole as the locating reference, expanding the process hole to the required size, and machining all concentric countersunk holes.

3. The processing method for a thin-walled transmission positioning connecting plate with low stiffness as described in claim 1 further includes: Step S8: Perform surface treatment according to design requirements.

4. The processing method for a thin-walled transmission positioning connecting plate with low stiffness as described in claim 1, wherein, In step S1, when rough grinding the reference surface of the upper and lower planes, the parallelism of the two planes is set to ≤0.1mm, and a 0.3mm allowance is left for each of the upper and lower planes.

5. The processing method for a thin-walled transmission positioning connecting plate with low stiffness as described in claim 1, wherein, In step S1, when semi-finish grinding the upper and lower planes, the parallelism of the two planes is set to ≤0.05mm, and a fine grinding allowance of 0.2mm is left for the upper and lower planes respectively.

6. The processing method for a thin-walled transmission positioning connecting plate with low stiffness as described in claim 1, wherein, In step S4, the aging treatment is low-temperature aging at 120-180°C.

7. The processing method for a thin-walled transmission positioning connecting plate with low stiffness as described in claim 1, wherein, In step S5, the parallelism between the upper and lower planes is ≤0.03mm.

8. The processing method for a thin-walled transmission positioning connecting plate with low stiffness as described in claim 1, wherein, In step S5, the upper and lower planes are machined using a high-precision surface grinder with low feed and high frequency.

9. The processing method for a thin-walled transmission positioning connecting plate with low stiffness as described in claim 1, wherein, In step S5, the "one surface and two pins" positioning method is used as the reference. After fine grinding a plane, the required step shape of the plane is finely milled, and the required through holes, positioning pin holes and threaded holes are machined on the bottom plate of the weak stiffness thin-walled transmission positioning connection plate body.

10. The processing method for a thin-walled transmission positioning connecting plate with low stiffness as described in claim 1, wherein, In step S6, the vibration aging time is 30-60 minutes.

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