A method for producing a subframe

Abstract

The present invention provides a production method for a subframe. By reasonably setting a casting positioning table, the transmission and conversion of the positioning reference is solved, and the influence of welding deformation on the workpiece is effectively reduced. The method can obtain a high-precision and high-quality lightweight profile and a cast welded subframe. The method has been tested and demonstrated in practice, and the problems of severe deformation and low precision of the welded subframe are solved.

Description

Technical Field

[0001] The invention relates to the technical field of auxiliary frame manufacturing, in particular to a method for producing a lightweight auxiliary frame. Background Art

[0002] With the development of lightweight automobiles, most automobile parts are being replaced by aluminum materials instead of steel materials. Subframes are one of the important parts of automobiles. Traditional subframes are generally made of steel plates stamped and welded, and are heavy. Now, subframes with mixed welding of profile castings are becoming more and more popular in the market. The profile casting mixed subframe is mainly composed of left castings, right castings, front profiles and rear profiles. The connected parts are connected by welding process. Among them, A1, A2, A3 and A4 are the mounting surface references of the subframe, B holes and C holes are the mounting hole references, E holes and F holes are the other two body mounting holes, and the subframe is connected to the body through a total of four mounting holes. This patent provides a production method of a profile casting mixed subframe. Summary of the invention

[0003] The purpose of the present invention is to provide a production method of a profile casting hybrid subframe and give a detailed production process. The method can be used to obtain a profile casting tailor-welded subframe.

[0004] In order to achieve the above object, a method for producing a hybrid subframe of a profile casting according to the present invention comprises the following steps:

[0005] (I) Casting of left and right castings. When casting the left casting, a front positioning platform is set on the front of the left casting. The front positioning platform has a diameter of 10mm and a height of 3mm. The horizontal distance between the front positioning platform and the weld joint is 10-12mm. When casting the right casting, a back positioning platform is set on the back of the right casting. The back positioning platform has a diameter of 10mm and a height of 3mm. The horizontal distance between the back positioning platform and the weld joint is 10-12mm.

[0006] (II) Pre-machining of the left and right castings. Pre-machining is performed on the left and right castings to machine the positioning surfaces A1, A2, A3, A4, a1, a2, a3, a4, positioning holes B, C, E, F, and various welds. Among them, the left casting is machined with body mounting holes B, E and upper and lower surfaces A1, a1, A3, a3. Compared with the finished product, the diameter of holes B and E is set with a 2mm machining allowance on one side, and the upper and lower surfaces A1, a1, A3, a3 of holes B and E are set with a 2mm machining allowance on each side. The front positioning table is not machined during pre-machining, and the casting surface is retained. The right casting is machined with body mounting holes C, F and upper and lower surfaces A2, a2, A4, a4. Compared with the finished product, the diameter of holes C and F is set with a 2mm machining allowance on one side, and the upper and lower surfaces A2, a2, A4, a4 ​​of holes C and F are set with a 2mm machining allowance on each side. The back positioning table is milled out of the plane during pre-machining.

[0007] (III) Pre-machining of the front and rear profiles. Process the front and rear profiles to form welds, clean them, remove oil and other impurities, and weld them for later use.

[0008] (IV) Assemble and weld. Assemble the left casting, right casting, front profile and rear profile to the welding fixture. The left casting is positioned by a1 and a3, and is positioned angularly by holes B and E. The right casting is positioned by a2 and a4, and is positioned angularly by holes C and F. After assembly, the weld is welded by welding positioner and welding robot.

[0009] (V) Machining after welding. The process is completed by two-step machining using a five-axis machining center. The first step of machining is milling, with the lower surface a3 of the E hole, the lower surface a4 of the F hole, and the back positioning table for surface positioning. The E hole and the F hole are used for angular positioning, forming a one-side two-pin positioning method. The first step of machining is milling to produce the sub-frame's reference A1 surface, a1 surface, A2 surface, a2 surface, B hole, C hole, front positioning table, and features that can be processed on the front. The second step of machining is milling, with the upper surface A1 surface of the B hole, the upper surface A2 surface of the C hole, and the front positioning table for surface positioning. The B hole and the C hole are used for angular positioning, forming a one-side two-pin positioning method. The second step of machining is milling, with the upper surface A1 surface of the B hole, the upper surface A2 surface of the C hole, and the front positioning table for surface positioning. The B hole and the C hole are used for angular positioning, forming a one-side two-pin positioning method. The second step of machining is milling, with the upper surface A1 surface of the B hole, the upper surface A2 surface of the C hole, and the front positioning table for surface positioning.

[0010] (VI) Deburring and cleaning. Deburr all machined parts and clean the remaining emulsion, aluminum chips and other impurities.

[0011] (VII) Press-fit bushings into the mounting holes of the vehicle body.

[0012] The advantages of the present invention are: (1) the reserved positioning point position of the casting is provided, and the pre-machining scheme before welding is provided, so that the welding can achieve high-precision positioning, which is conducive to reducing welding deformation and improving welding quality; (2) reasonable process allowance and positioning reference conversion are adopted, so that the machining after welding can ensure accuracy while greatly reducing the manufacturing cost. (3) This method has been tested and demonstrated in practice, and solves the problem of severe deformation and low precision of the tailor-welded subframe.

[0013] The present invention provides a production method and key parameters of a profile casting tailor-welded subframe. By reasonably setting a casting positioning table, the transmission and conversion of the positioning reference is solved, and the influence of welding deformation on the workpiece is effectively reduced. The method can obtain a high-precision and high-quality lightweight profile and casting tailor-welded subframe. It has been demonstrated in actual production that a high-precision subframe can be successfully manufactured. It is a correct and effective process method. BRIEF DESCRIPTION OF THE DRAWINGS

[0014] Figure 1The present invention is a front view schematic diagram of a subframe of a method for producing a hybrid subframe of a profile casting.

[0015] Figure 2 It is a schematic diagram of the back side of a subframe of a method for producing a hybrid subframe of a profile casting according to the present invention.

[0016] In the figure, 1-left casting, 2-right casting, 3-front profile, 4-rear profile, 5-weld, 6-back positioning platform, 7-front positioning platform. DETAILED DESCRIPTION

[0017] The specific details of the present invention are given below in conjunction with the accompanying drawings and embodiments.

[0018] The profile casting hybrid subframe is mainly composed of a left casting 1, a right casting 2, a front profile 3 and a rear profile 4, and the connected parts are connected by a welding process, wherein A1, A2, A3 and A4 are mounting surface references of the subframe, B holes and C holes are mounting hole references, E holes and F holes are two other body mounting holes, and the subframe is connected to the body through a total of four mounting holes.

[0019] The present invention provides a method for producing a hybrid subframe of a profile casting, comprising the following steps:

[0020] (I) Casting of left and right castings. When casting the left casting 1, a front positioning platform 7 is reserved on the front side. The front positioning platform 7 has a diameter of 10 mm and a height of 3 mm. The horizontal distance between the front positioning platform 7 and the weld joint is 10-12 mm. When casting the right casting 2, a back positioning platform 6 is reserved on the back side. The back positioning platform 6 has a diameter of 10 mm and a height of 3 mm. The horizontal distance between the back positioning platform 6 and the weld joint is 10-12 mm.

[0021] (II) Pre-machining of the left and right castings. Pre-machining is performed on the left casting 1 and the right casting 2 to machine the positioning surfaces A1, A2, A3, A4, a1, a2, a3, a4, positioning holes B, C, E, F, and various welds. Among them, the left casting 1 is machined with body mounting holes B, E and upper and lower surfaces A1, a1, A3, a3. Compared with the finished product, the diameter of holes B and E is set with a 2mm machining allowance on one side, and the upper and lower surfaces A1, a1, A3, a3 of holes B and E are set with a 2mm machining allowance on each side. During pre-machining, the front positioning table 7 is not machined, and the casting surface is retained. The right casting 2 is machined with body mounting holes C, F and upper and lower surfaces A2, a2, A4, a4. Compared with the finished product, the diameter of holes C and F is set with a 2mm machining allowance on one side, and the upper and lower surfaces A2, a2, A4, a4 ​​of holes C and F are set with a 2mm machining allowance on each side. During pre-machining, the back positioning platform 6 is milled out into a flat surface.

[0022] (III) Pre-machining of the front profile and the rear profile. The front profile 3 and the rear profile 4 are processed into welding joints, cleaned, and impurities such as oil stains are removed, and then welded for standby use.

[0023] (IV) Assemble and weld. Assemble the left casting 1, the right casting 2, the front profile 3 and the rear profile 4 to the welding fixture. The left casting 1 is positioned by a1 and a3, and is positioned angularly by holes B and E. The right casting 2 is positioned by a2 and a4, and is positioned angularly by holes C and F. After the assembly is completed, the weld is welded by the welding positioner and the welding robot.

[0024] (V) Machining after welding. The process is completed by two-step machining using a five-axis machining center. The first step of machining is milling, with the lower surface a3 of the E hole, the lower surface a4 of the F hole, and the back positioning table 6 for surface positioning. The E hole and the F hole are used for angular positioning, forming a one-side two-pin positioning method. The first step of machining is milling to produce the sub-frame's reference A1 surface, a1 surface, A2 surface, a2 surface, B hole, C hole, front positioning table 7, and features that can be processed on the front. The second step of machining is milling, with the upper surface A1 surface of the B hole, the upper surface A2 surface of the C hole, and the front positioning table 7 for surface positioning. The B hole and the C hole are used for angular positioning, forming a one-side two-pin positioning method. The second step of machining is milling, with the upper surface A1 surface of the B hole, the upper surface A2 surface of the C hole, and the front positioning table 7 for surface positioning. The B hole and the C hole are used for angular positioning, forming a one-side two-pin positioning method. The second step of machining is milling, with the upper surface A1 surface of the B hole, the upper surface A2 surface of the C hole, and the front positioning table 7 for surface positioning.

[0025] (VI) Deburring and cleaning. Deburr all machined parts and clean the remaining emulsion, aluminum chips and other impurities.

[0026] (VII) Press-fit bushings into the mounting holes of the vehicle body.

[0027] The advantages of the present invention are: (1) the reserved positioning point position of the casting is provided, and the pre-machining scheme before welding is provided, so that the welding can achieve high-precision positioning, which is conducive to reducing welding deformation and improving welding quality; (2) reasonable process allowance and positioning reference conversion are adopted, so that the machining after welding can ensure accuracy while greatly reducing the manufacturing cost. (3) This method has been tested and demonstrated in practice, and solves the problem of severe deformation and low precision of the tailor-welded subframe.

[0028] The present invention provides a production method and key parameters of a profile casting tailor-welded subframe. By reasonably setting a casting positioning table, the transmission and conversion of the positioning reference is solved, and the influence of welding deformation on the workpiece is effectively reduced. The method can obtain a high-precision and high-quality lightweight profile and casting tailor-welded subframe. It has been demonstrated in actual production that a high-precision subframe can be successfully manufactured. It is a correct and effective process method.

Claims

1. A method for producing a subframe, characterized in that: The method comprises the following steps: (I) casting the left casting and the right casting; (II) pre-machining the left casting and the right casting; (III) pre-machining the front profile and the rear profile; (IV) assembling and welding; (V) machining after welding; (VI) deburring and cleaning; (VII) pressing the bushing into the mounting hole of the vehicle body; In step (I), a front positioning platform (7) is reserved on the front side of the left casting (1) during casting, and a back positioning platform (6) is reserved on the back side of the right casting (2) during casting; The front positioning platform (7) has a diameter of 10 mm and a height of 3 mm, and the horizontal distance between the front positioning platform (7) and the weld joint is 10-12 mm; The back positioning platform (6) has a diameter of 10 mm and a height of 3 mm, and the horizontal distance between the back positioning platform (6) and the weld joint is 10-12 mm; In step (II), the left casting (1) and the right casting (2) are pre-machined to form positioning surfaces A1, A2, A3, A4, a1, a2, a3, a4, positioning holes B, C, E, F, and various welds; The left casting (1) is processed to have body mounting holes B and E and upper and lower surfaces A1, a1, A3, and a3. Compared with the finished product, the diameter of holes B and E is set with a 2mm machining allowance on one side, and the upper and lower surfaces A1, a1, A3, and a3 of holes B and E are set with a 2mm machining allowance respectively; the front positioning table (7) is not processed during pre-machining, and the casting surface is retained; The right casting (2) is machined to have body mounting holes C and F and upper and lower surfaces A2, a2, A4, a4. Compared with the finished product, the diameter of holes C and F is left with a 2mm machining allowance on one side, and the upper and lower surfaces A2, a2, A4, a4 ​​of holes C and F are left with a 2mm machining allowance respectively. During pre-machining, the back positioning table (6) is milled out with a flat surface. In step (V), OP10 processes the reference A1 surface, a1 surface, A2 surface, a2 surface, B hole, C hole, and front positioning platform (7) of the subframe; OP20 processes the A3 surface, a3 surface, A4 surface, a4 surface, E hole, and F hole of the subframe.

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