Aluminum alloy connecting rod big end machining method

Abstract

The application discloses a machining method for a small head of an aluminum alloy connecting rod, which comprises the following steps: S1, clamping and fixing the aluminum alloy connecting rod on a machine tool; S2, rough boring a small head hole of the aluminum alloy connecting rod; S3, semi-precision boring the small head hole of the aluminum alloy connecting rod, then performing low-temperature aging, wherein the low-temperature aging temperature is 120±20 DEG C, the low-temperature aging holding time is 4-6h, and the low-temperature aging is air-cooled to room temperature; S4, precision boring the small head hole of the aluminum alloy connecting rod, wherein the small head hole radius after the precision boring is R 设定 +(0.1-0.2)mm, R 设定 is a design value of the small head hole radius; and S5, sequentially machining an installation inclined hole, an oil hole and an outer contour of the small head of the aluminum alloy connecting rod. The machining method can guarantee the machining quality of the small head of the aluminum alloy connecting rod and improve machining efficiency.

Description

Technical Field

[0001] This invention relates to the processing and manufacturing of aluminum alloy connecting rods, specifically to a method for processing the small end of an aluminum alloy connecting rod. Background Technology

[0002] The aluminum alloy connecting rod of the fracturing pump has a special structure and is difficult to process. The connection between the small end and the crosshead pin is only a section of arc surface, which is connected by four bolts. Various deformations occur during processing, such as the diameter becoming smaller and the middle of the arc surface becoming bulge. This leads to unstable assembly quality of the crosshead pin, which increases the difficulty of the subsequent precision boring process of the large end of the aluminum alloy connecting rod and poses a great risk to quality. The scrap rate is about 20%. Summary of the Invention

[0003] The purpose of this invention is to provide a method for machining the small end of an aluminum alloy connecting rod, which can ensure the machining quality of the small end of the aluminum alloy connecting rod and improve machining efficiency.

[0004] The method for machining the small end of an aluminum alloy connecting rod according to the present invention includes the following steps: S1, clamp and fix the aluminum alloy connecting rod on the machine tool; S2, rough boring of small end bore of aluminum alloy connecting rod; S3, semi-precision boring of small end hole of aluminum alloy connecting rod, then low temperature aging, low temperature aging temperature is 120±20℃, low temperature aging holding time is 4~6h, air cooling to room temperature; S4, precision boring of the small end hole of the aluminum alloy connecting rod, the radius of the small end hole after precision boring is R. 设定 + (0.1~0.2) mm, R 设定 This is the design value for the small-head hole radius; S5, sequentially machine the mounting oblique hole, oil hole and outer contour of the small end of the aluminum alloy connecting rod.

[0005] Furthermore, the S5 uses milling to machine the oblique mounting hole for the small end of the aluminum alloy connecting rod.

[0006] Furthermore, the specific steps for machining the oil hole of the aluminum alloy connecting small end in S5 are as follows: rough boring the positioning pin hole at the end of the oil hole, the single-sided machining allowance of the positioning pin hole during rough boring is set to 0.2~0.5mm, drilling the oil hole to the design size, and fine boring the positioning pin hole to the design size.

[0007] Furthermore, in S5, the single feed rate of the tool when machining the mounting oblique hole, oil hole and outer contour of the small end of the aluminum alloy connecting rod is 0.8~1.5mm.

[0008] Furthermore, the single-sided machining allowance is set to 0.2~0.6mm when semi-finish boring the small end hole of the aluminum alloy connecting rod in S3.

[0009] Compared with the prior art, the present invention has the following beneficial effects.

[0010] 1. This invention employs low-temperature aging after semi-finish boring to eliminate residual stress from the semi-finish boring process, stabilizing the microstructure and dimensions of the small end hole in the aluminum alloy connecting rod, thus laying a foundation for stabilizing the subsequent deformation range. The radius of the small end hole after finish boring is R. 设定 + (0.1~0.2) mm, that is, based on the set value, the radius of the small end hole is increased, and the deformation amount is reserved to ensure that it enters the tolerance zone during subsequent deformation, thus ensuring the machining quality of the small end of the aluminum alloy connecting rod. The scrap rate of the precision boring process is reduced from 20% to 0%, while reducing the auxiliary time such as alignment, and greatly improving the machining efficiency.

[0011] 2. This invention uses milling to process the small end mounting oblique hole of the aluminum alloy connecting rod, rough boring the positioning pin hole at the end of the oil hole, drilling the oil hole to the design size, and fine boring the positioning pin hole to the design size. This reduces the machining stress in the vertical direction of the arc surface of the small end hole and avoids machining stress deformation of the small end hole in the direction of the mounting oblique hole, positioning pin hole and oil hole. Attached Figure Description

[0012] Figure 1 This is a schematic diagram of the aluminum alloy connecting rod in one embodiment of the present invention.

[0013] In the diagram, 1—aluminum alloy connecting rod body, 2—small end hole, 3—mounting oblique hole, 4—locating pin hole, and 5—oil hole. Detailed Implementation

[0014] To make the objectives, technical solutions, and advantages of this invention clearer, the technical solutions of the embodiments of this invention will be clearly and completely described below with reference to the accompanying drawings. Obviously, the described embodiments are only some embodiments of this invention, and not all embodiments. Based on the embodiments of this invention, all other embodiments obtained by those skilled in the art without creative effort are within the scope of protection of this invention.

[0015] A method for machining the small end of an aluminum alloy connecting rod includes the following steps: S1, clamp and fix the aluminum alloy connecting rod on the machine tool.

[0016] S2, rough boring of the small end hole of the aluminum alloy connecting rod.

[0017] S3, semi-finish boring of the small end hole of the aluminum alloy connecting rod, followed by low-temperature aging at 120℃ for 5 hours, and then air cooling to room temperature. This low-temperature aging treatment eliminates residual stress from the semi-finish boring process, stabilizes the microstructure and dimensions of the small end hole of the aluminum alloy connecting rod, and lays a foundation for stabilizing the subsequent deformation range. The machining allowance on one side during the semi-finish boring of the small end hole of the aluminum alloy connecting rod is set to 0.2~0.6mm.

[0018] S4, see S4 Figure 1 Precision boring of the small end hole 2 of the aluminum alloy connecting rod body 1, the radius of the small end hole after precision boring is R=R 设定 + (0.1~0.2) mm, R 设定 The design value for the small end hole radius was set. Based on the set value, the small end hole radius was increased to allow for deformation, ensuring that subsequent deformation would enter the tolerance zone. This guaranteed the machining quality of the small end of the aluminum alloy connecting rod, reduced the scrap rate of the precision boring process from 20% to 0%, and also reduced auxiliary time such as alignment, significantly improving machining efficiency.

[0019] In this embodiment, the design value of the small end hole radius is 180, while during precision boring in this embodiment, the small end hole radius is machined to 180.1~180.2, leaving room for deformation.

[0020] S5, sequentially process the mounting oblique hole 3, oil hole 5 and outer contour of the small end of the aluminum alloy connecting rod body 1, and use milling to process the mounting oblique hole of the small end of the aluminum alloy connecting rod.

[0021] The specific steps for machining the oil hole in the small end of the aluminum alloy connector are as follows: rough boring the locating pin hole 4 at the end of the oil hole, with a single-sided machining allowance of 0.2~0.5mm set during rough boring; drilling the oil hole 5 to the design size; and finish boring the locating pin hole 4 to the design size. Using boring to machine the mounting oblique hole 3 and the locating pin hole 4, and drilling to machine the oil hole, reduces the machining stress in the vertical direction of the small end hole's arc surface, preventing machining stress deformation of the small end hole in the directions of the mounting oblique hole, the locating pin hole, and the oil hole.

[0022] When machining the mounting oblique hole, oil hole, and outer contour of the small end of the aluminum alloy connecting rod, the single feed rate of the tool is 0.8~1.5mm. Sufficient coolant is supplied during machining to prevent deformation of the aluminum alloy connecting rod due to excessively high temperatures during processing, further ensuring the machining quality of the small end of the aluminum alloy connecting rod.

[0023] The above description is merely a preferred embodiment of this application and is not intended to limit this application. Any modifications, equivalent substitutions, and improvements made within the spirit and principles of this application should be included within the protection scope of this application.

Claims

1. A method for machining the small end of an aluminum alloy connecting rod, characterized in that, Includes the following steps: S1, clamp and fix the aluminum alloy connecting rod on the machine tool; S2, rough boring of small end bore of aluminum alloy connecting rod; S3, semi-precision boring of small end hole of aluminum alloy connecting rod, then low temperature aging, low temperature aging temperature is 120±20℃, low temperature aging holding time is 4~6h, air cooling to room temperature; S4, precision boring of the small end hole of the aluminum alloy connecting rod, the radius of the small end hole after precision boring is R. 设定 + (0.1~0.2) mm, R 设定 This is the design value for the small-head hole radius; S5, sequentially machine the mounting oblique hole, oil hole and outer contour of the small end of the aluminum alloy connecting rod; The small end mounting oblique hole of the aluminum alloy connecting rod is machined by milling. The specific steps for machining the oil hole of the aluminum alloy connecting small end are as follows: rough boring the positioning pin hole at the end of the oil hole, with the single-sided machining allowance for rough boring of the positioning pin hole set to 0.2~0.5mm, drilling the oil hole to the design size, and finish boring the positioning pin hole to the design size.

2. The method for machining the small end of an aluminum alloy connecting rod according to claim 1, characterized in that, When machining the mounting oblique hole, oil hole, and outer contour of the small end of an aluminum alloy connecting rod in S5, the single feed rate of the tool is 0.8~1.5mm.

3. The method for machining the small end of an aluminum alloy connecting rod according to claim 1, characterized in that: When semi-finish boring the small end hole of the aluminum alloy connecting rod in S3, the machining allowance on one side is set to 0.2~0.6mm.

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