Method for machining a central hole of a motor vehicle flange

Abstract

The application relates to the field of automobile part manufacturing, and discloses a center hole machining method of an automobile flange. The aluminum sleeve is prepositioned in a mold cavity, and the aluminum sleeve and aluminum liquid are fused to form an integrated casting blank. Since the outer step of the aluminum sleeve is shaped with the inner step of the automobile flange product, the aluminum sleeve is removed through machining, the machining allowance of the casting blank is greatly reduced, and the porosity defect of the casting blank is solved from the root.

Description

TECHNICAL FIELD

[0001] The application relates to the field of automobile part manufacturing, in particular to a center hole machining method of an automobile flange. BACKGROUND

[0002] In a brake system of a heavy truck, a flange product is matched with a piston, at least two inner steps with a certain depth and a diameter larger than that of a center hole are formed at the center hole of the flange product, due to the inner steps, the casting blank cannot be demolded in die casting processing, therefore, the flange product is mainly processed into a casting blank through die casting, an initial center hole is reserved in the center of the casting blank, and the initial center hole is machined to form a standard center hole and the inner steps, it is measured that the maximum machining allowance of the casting blank reaches 4.56 mm, if there is pyrolysis in a deep part of a model cavity, there is a sudden thickening part in the die cavity along the filling direction of the aluminum liquid, and a regular and smooth surface hole defect, commonly known as a porosity defect, is easily formed in the casting blank. Therefore, the surface of the inner steps of the flange product formed by the existing machining method has the porosity defect, and the yield is low. In order to improve the quality of the flange product, a center hole machining method of an automobile flange needs to be developed.

[0003] It can be seen that the prior art still needs to be improved and enhanced. SUMMARY

[0004] In view of the above shortcomings of the prior art, the purpose of the application is to provide a center hole machining method capable of solving the porosity defect and improving the quality of an automobile flange product.

[0005] In order to achieve the above purpose, the application adopts the following technical scheme:

[0006] A production process of an automobile flange comprises the following steps:

[0007] S1: a die casting die is in an open mold state, and an aluminum sleeve is placed in a cavity of the die casting die;

[0008] S2: the die casting die is closed, the aluminum sleeve is integrally formed with aluminum liquid into a casting blank, and the aluminum sleeve is located at the center hole of the casting blank;

[0009] S3: the center hole of the casting blank is machined, the aluminum sleeve in the casting blank is removed, and the machining allowance of the inner step at the center hole of the casting blank is less than or equal to 0.6 mm;

[0010] S4: the center hole of the casting blank is machined to remove the machining allowance, so as to form at least one inner step at the center hole of the casting blank.

[0011] As a further improvement of the above technical solution, the aluminum sleeve comprises a cylindrical body and an outer step arranged on the outer wall of the cylindrical body, the number of the outer steps is the same as and one-to-one corresponding to the number of the inner steps.

[0012] As a further improvement of the above technical solution, the outer periphery wall of the outer step is provided with a plurality of protrusions arranged in a circumferential array.

[0013] As a further improvement of the above technical solution, the outer step is provided with two.

[0014] As a further improvement of the above technical solution, the outer diameter of the upper outer step is greater than the outer diameter of the lower outer step, and the thickness of the upper outer step is less than the thickness of the lower outer step.

[0015] As a further improvement of the above technical solution, the die casting mold comprises a fixed mold core and a movable mold core, the middle part of the movable mold core is provided with a pin for forming a center hole of the casting blank, the pin is provided with a cylindrical head for sleeving the aluminum sleeve, and the cylindrical head and the movable mold core form an annular cavity.

[0016] As a further improvement of the above technical solution, the inner diameter of the cylindrical body of the aluminum sleeve is 33±0.1mm, the outer diameter of the cylindrical body is 38.2±0.1mm, the diameter of the upper outer step is 45.1±0.1mm, the diameter of the lower outer step is 42.1±0.1mm, the thickness of the upper outer step is 3.9±0.1mm, and the thickness of the lower outer step is 7.8±0.1mm.

[0017] As a further improvement of the above technical solution, the center hole of the finished automobile flange has two inner steps, the diameter of the center hole is 40.1±0.1mm, the diameter of the upper inner step is 47.57±0.1mm, and the diameter of the lower inner step is 44.5±0.1mm.

[0018] As a further improvement of the above technical solution, in step S3, the machining method adopts hole expansion and / or boring for rough machining; in step S4, the machining method adopts boring for finishing.

[0019] The beneficial effects of the present application: compared with the prior art, the production process of the automobile flange provided by the present application ingeniously pre-arranges the aluminum sleeve in the cavity, so that the aluminum sleeve and the aluminum liquid are fused to form an integrated casting blank, and since the outer steps of the aluminum sleeve are shaped with the inner steps of the finished automobile flange, and then the aluminum sleeve is removed by machining, the machining allowance of the casting blank will be greatly reduced, thereby solving the porosity defect of the casting blank from the root. BRIEF DESCRIPTION OF DRAWINGS

[0020] Figure 1 The flow chart of the production process of the automobile flange.

[0021] Figure 2 is a sectional view of the automobile flange finished product.

[0022] Figure 3 is a sectional view of the blank formed by the prior art process, the grid area indicated by A represents the machining allowance.

[0023] Figure 4 is a sectional view of the aluminum sleeve on the casting blank, the area indicated by B represents the machining allowance.

[0024] Figure 5 is an assembly view of the pin and the movable mold core.

[0025] Figure 6 is a perspective view of the aluminum sleeve.

[0026] Figure 7 is an assembly view of the aluminum sleeve on the pin and the movable mold core.

[0027] Figure 8 is a perspective view of the aluminum sleeve on the casting blank.

[0028] Figure 9 is a perspective view of the automobile flange finished product.

[0029] Main element symbol explanation: 1-aluminum sleeve, 11-cylinder, 12-outer step, 13-protrusion, 2-movable mold core, 21-annular cavity, 3-pin, 4-flange finished product, 41-center hole, 42-inner step, 5-casting blank. DETAILED DESCRIPTION

[0030] The present application provides a production process of automobile flange. In order to make the purpose, technical scheme and effect of the present application more clear and definite, the present application is further described in detail below with reference to the drawings and examples. It should be understood that the specific examples described herein are only used to explain the present application, and are not used to limit the protection scope of the present application.

[0031] In the present embodiment, as shown in Figure 2 , the center hole 41 of the automobile flange finished product 4 has two inner steps 42, and the size requirements of the automobile flange finished product 4 are as follows: the diameter of the center hole 41 is 40.1±0.1mm, the diameter of the upper inner step 42 is 47.57±0.1mm, and the diameter of the lower inner step 42 is 44.5±0.1mm. When the manufacturing method in the prior art is used, then the blank formed by the die casting will be as shown in Figure 3As shown, in order to ensure that the blank can be demolded, the diameter of the reserved center hole 41 is 34mm, when the upper inner step 42 is machined, the maximum machining allowance of 4.56mm is correspondingly generated, it can be understood that the larger the machining allowance, the thicker the wall thickness of the blank, the more likely to produce porosity defects.

[0032] Therefore, please refer to Figure 1 The present application innovatively provides a production process of an automobile flange, comprising the following steps:

[0033] S1: see Figure 5 and Figure 7 As shown, the die casting mold is in the open mold state, the aluminum sleeve 1 is put into the cavity of the die casting mold;

[0034] It can be understood that the aluminum sleeve 1 is a pre-processed independent part, which is used as a pre-embedded part,

[0035] See Figure 6 As shown, the aluminum sleeve 1 includes a cylindrical body 11 and an outer step 12 arranged on the outer wall of the cylindrical body 11, the number of the outer steps 12 is the same as and corresponds to the number of the inner steps 42, so the aluminum sleeve 1 is provided with two outer steps 12. That is, the outer steps 12 of the aluminum sleeve 1 are manufactured according to the shape and size of the inner steps 42 of the automobile flange finished product 4, specifically, the inner diameter of the cylindrical body 11 of the aluminum sleeve 1 is 33mm, the outer diameter of the cylindrical body 11 is 38.2mm, the diameter of the upper outer step 12 is 45.1mm, the diameter of the lower outer step 12 is 42.1mm, the thickness of the upper outer step 12 is 3.9mm, and the thickness of the lower outer step 12 is 7.8mm. That is, the outer diameter of the upper outer step 12 is greater than the outer diameter of the lower outer step 12, and the thickness of the upper outer step 12 is less than the thickness of the lower outer step 12.

[0036] In fact, the center hole 41 machining method of the automobile flange provided by the present application does not need to improve the original die casting mold, but directly uses the original die casting mold for machining, which saves the huge cost of new die casting mold, the die casting mold includes a fixed mold core and a movable mold core 2, the middle part of the movable mold core 2 is provided with an insert pin 3 for forming a center hole 41 of a casting blank 5, the insert pin 3 is provided with a cylindrical head, and an annular cavity 21 is formed between the cylindrical head and the movable mold core 2, the aluminum sleeve 1 is sleeved on the cylindrical head of the insert pin 3 and located in the annular cavity 21.

[0037] S2: see Figure 4 and Figure 8 As shown, the die casting mold is closed, the aluminum sleeve 1 is integrally formed with the aluminum liquid into the casting blank 5, and the aluminum sleeve 1 is located at the center hole 41 of the casting blank 5; it can be understood that the aluminum sleeve 1 replaces the original blank part combined with the insert pin 3 and the aluminum liquid, thereby reducing the wall thickness of the casting blank 5 at the center hole 41 and the inner step 42.

[0038] Specifically, after the fixed mold core and the movable mold core 2 are combined, the fixed mold core restricts the axial movement of the aluminum sleeve 1; since the aluminum sleeve 1 and the aluminum liquid are both aluminum materials, the aluminum sleeve 1 and the aluminum liquid can be fused together. When the casting blank 5 is formed, in order to make the aluminum liquid better wrap the aluminum sleeve 1 and be cast into a shape, prevent the aluminum sleeve 1 from rotating, a plurality of protrusions 13 arranged in an array along the circumference are arranged on the outer circumferential wall of the outer step 12, the presence of the protrusions 13 increases the contact area between the aluminum sleeve 1 and the aluminum liquid, so that the aluminum liquid is more likely to wrap the aluminum sleeve 1 in the casting process. This can effectively improve the bonding strength of the aluminum liquid and the aluminum sleeve 1, prevent the aluminum sleeve 1 from rotating or shifting during the forming process; in addition, the design of the protrusions 13 helps to guide the aluminum liquid to flow along the surface of the aluminum sleeve 1, so as to more uniformly wrap the aluminum sleeve 1. This can reduce the generation of gas inclusions and bubbles, and improve the quality of the casting blank 5.

[0039] S3: Machining the center hole 41 of the casting blank 5, the machining tool body adopts the machining mode of hole expansion and / or boring to perform rough machining, removes the aluminum sleeve 1 in the casting blank 5, and makes the machining allowance B of the inner step 42 at the center hole 41 of the casting blank 5 be 0.6 mm or less; it can be understood that the blank wall thickness formed by the outer step 12 of the aluminum sleeve 1 and the inner step 42 of the automobile flange finished product 4 is only 0.6 mm, and the blank wall thickness formed by the cylindrical body 11 of the aluminum sleeve 1 and the center hole 41 of the automobile flange finished product 4 is only 0.6 mm, that is, only the part that is solidified by the aluminum liquid belongs to the machining allowance of the casting blank, and the aluminum sleeve does not belong to the machining allowance of the casting blank, the shape and size of the aluminum sleeve 1 are known in advance, and the removal machining of the aluminum sleeve is accurate; the machining allowance is small, so the generation of porosity defects is avoided.

[0040] S4: see Figure 9 Fig. 4, machining the center hole 41 of the casting blank 5, the machining tool body adopts the machining mode of hole expansion and / or boring to perform fine machining, removes the machining allowance, and forms at least one inner step 42 at the center hole 41 of the casting blank 5. Since the machining allowance is greatly reduced, the finally machined center hole 41 and inner step 42 are smooth in surface and have no porosity problem.

[0041] Compared with the prior art, the production process of the automobile flange provided by the application ingeniously prepositions the aluminum sleeve 1 in the cavity, fuses the aluminum sleeve 1 and the aluminum liquid to form an integrated casting blank 5, and since the outer step 12 of the aluminum sleeve 1 is shaped with the inner step 42 of the automobile flange finished product 4, and then the aluminum sleeve 1 is removed by machining, the machining allowance of the casting blank 5 will be greatly reduced, which solves the porosity defect of the casting blank 5 from the root.

[0042] In the description of the present application, it is to be understood by the terms "center", "longitudinal", "lateral", "length", "width", "thickness", "upper", "lower", "front", "rear", "left", "right", "vertical", "horizontal", "top", "bottom", "inner", "outer", "clockwise", "counterclockwise" and the like indicate the orientation or positional relationship shown in the drawings, which are only for the convenience of describing the present application and simplifying the description, and do not indicate or imply that the devices or elements referred to must have a particular orientation, be constructed and operated in a particular orientation, and therefore cannot be understood as a limitation on the present application.

[0043] In the description of the present application, it is to be understood that unless otherwise explicitly specified and limited, the terms "mounting", "connecting", "connecting" should be understood broadly, for example, it can be fixedly connected, or it can be detachably connected, or integrally connected; it can be mechanically connected, or it can be electrically connected or can communicate with each other; it can be directly connected, or indirectly connected through an intermediate medium, it can be the internal communication of two elements or the interaction relationship between two elements. For those skilled in the art, the specific meaning of the above terms in the present application can be understood according to the specific circumstances.

[0044] It can be understood that for those skilled in the art, equivalent replacement or change can be made according to the technical scheme and the inventive concept of the present application, and all these changes or replacements shall belong to the protection scope of the present application.

Claims

1. A method of machining a center hole of an automotive flange, characterized by, The method comprises the following steps: S1: placing the aluminum sleeve into the cavity of the die casting mold in an open mold state; S2: closing the die casting mold, and integrally forming the aluminum sleeve and the aluminum liquid into a casting blank, with the aluminum sleeve located at the center hole of the casting blank; S3: machining the center hole of the casting blank, and removing the aluminum sleeve in the casting blank to make the inner step at the center hole of the casting blank have a machining allowance of 0.6 mm or less; S4: machining the center hole of the casting blank to remove the machining allowance to form an inner step at the center hole of the casting blank; The aluminum sleeve comprises a cylindrical body and an outer step arranged on the outer wall of the cylindrical body, the number of the outer steps is the same as and one-to-one corresponds to the number of the inner steps; the outer peripheral wall of the outer step is provided with a plurality of protrusions arranged in a circumferential array; the outer step is provided with two outer steps; the outer diameter of the upper outer step is greater than the outer diameter of the lower outer step, and the thickness of the upper outer step is less than the thickness of the lower outer step; The inner diameter of the cylindrical body of the aluminum sleeve is 33±0.1 mm, the outer diameter of the cylindrical body is 38.2±0.1 mm, the diameter of the upper outer step is 45.1±0.1 mm, the diameter of the lower outer step is 42.1±0.1 mm, the thickness of the upper outer step is 3.9±0.1 mm, and the thickness of the lower outer step is 7.8±0.1 mm; the center hole of the finished automobile flange has two inner steps, the diameter of the center hole is 40.1±0.1 mm, the diameter of the upper inner step is 47.57±0.1 mm, and the diameter of the lower inner step is 44.5±0.1 mm; The die casting mold comprises a fixed mold core and a movable mold core, the middle part of the movable mold core is provided with a pin for forming a center hole of the casting blank, and the pin is provided with a cylindrical head for sleeving the aluminum sleeve, and the cylindrical head and the movable mold core form an annular cavity.

2. The method of machining a center hole of an automotive flange according to claim 1, wherein In step S3, the machining method adopts reaming and / or boring for rough machining; in step S4, the machining method adopts boring for finish machining.

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