Method and apparatus for forming flat surfaces on curved surfaces of parts

Abstract

The present application relates to the technical field of machining, in particular to a forming method and equipment for flat surface on curved surface structure of a part, wherein the forming equipment comprises a primary forming die and a secondary forming die, the primary forming die comprises a primary forming upper die and a primary forming lower die, the secondary forming die comprises a secondary forming upper die and a secondary forming lower die, the primary forming upper die, the primary forming lower die and the secondary forming lower die have cavities, and the opening width of the cavities of the primary forming lower die and the secondary forming lower die is smaller than the cross-sectional diameter of the part to be machined; the forming method comprises the steps of primary stamping preparation, primary stamping, secondary stamping preparation and secondary stamping. The present application improves the operation mode of the traditional process using inner filler support forming, improves the machining quality, increases the applicable scenarios, and the matching equipment is simple and easy to realize.

Description

TECHNICAL FIELD

[0001] The present application relates to the technical field of mechanical processing, in particular to a forming method and equipment for flat surface on part curved surface structure. BACKGROUND

[0002] In the automobile parts manufacturing industry, there are cases where part of the outer wall of a tubular part needs to be processed into a flat surface. In the processing process, a corresponding internal object (internal filler) is generally prepared to support the processing process to ensure the surface flatness of the processing part. However, this kind of processing technology is not friendly to operation, not only the internal filler needs to be prepared in advance, but also the positioning of the filling position is subject to the structure inside the pipe, so the whole processing process restricts the production efficiency. In addition, it is difficult to process the flat surface of a relatively complex structure, for example, some tubular parts have bending structure, and the processing position is close to the bending part. This kind of structure is not easy to make the internal filler reach the corresponding position inside the pipe, greatly increasing the processing difficulty, and even unable to process. For this purpose, if the internal object support is not used, and the flat surface of the curved surface part is directly processed by the flat surface of the external stamping structure in the stamping mode, it is relatively easy to cause continuous local depression around the processing surface, which cannot achieve the expected processing effect, resulting in large quality defects of the part, and even finally leading to the scrap of the part and causing economic loss. SUMMARY

[0003] The purpose of the present application is to provide a forming method and equipment for flat surface on part curved surface structure, which solves the above technical problems.

[0004] The technical problems solved by the present application can be realized by using the following technical solutions:

[0005] The forming method and equipment for flat surface on part curved surface structure, wherein the forming equipment comprises a primary forming die and a secondary forming die, the primary forming die comprises a primary forming upper die and a primary forming lower die, the secondary forming die comprises a secondary forming upper die and a secondary forming lower die, the primary forming upper die, the primary forming lower die and the secondary forming lower die have a cavity, and the opening width of the cavity of the primary forming lower die and the secondary forming lower die is smaller than the cross-sectional diameter of the part to be processed,

[0006] The forming method comprises the following steps:

[0007] 1) Place the part to be processed in the cavity of the primary forming lower die, so that the surface to be processed of the part to be processed is exposed to the cavity;

[0008] 2) through the one-time forming upper die to the exposed surface of the part to be processed in the cavity of the one-time forming lower die from top to bottom stamping, until the one-time forming upper die and the one-time forming lower die between the reserved height between 1.0mm ~ 2.5mm;

[0009] 3) the part to be processed is placed in the cavity of the secondary forming lower die, so that the surface to be processed of the part to be processed is exposed to the cavity;

[0010] 4) through the secondary forming upper die to the exposed surface of the part to be processed in the cavity of the secondary forming lower die from top to bottom stamping, until the upper surface of the part to be processed is a horizontal plane.

[0011] The opening width of the cavity of the one-time forming upper die is greater than the opening width of the cavity of the one-time forming lower die.

[0012] The inner concave surface of the cavity of the one-time forming upper die is an arc surface, and in the cross section (profile) of the cavity, the inner concave surface of the cavity corresponds to an arc segment.

[0013] Preferably, the cavity of the one-time forming upper die is an elliptical surface, and the cavity cross section is a part of the structure of the elliptical shape with the long axis parallel to the horizontal plane, and the part of the structure is the local structure on the upper side of the long axis of the elliptical shape, and the bottom edge of the part of the structure is parallel to the long axis of the elliptical shape.

[0014] Preferably, in the step 2), the reserved height between the one-time forming upper die and the one-time forming lower die is between 1.5mm ~ 2.5mm.

[0015] The lower end surface of the secondary forming upper die is a rectangular structure, and the length of the rectangular structure is consistent with the length of the surface to be processed of the part to be processed.

[0016] The width of the rectangular structure is less than the opening width of the cavity of the secondary forming lower die.

[0017] The one-time forming upper die and the secondary forming upper die are fixed to the upper table of the press, and the one-time forming lower die and the secondary forming lower die are fixed to the lower table of the press.

[0018] Beneficial effects: due to the adoption of the above technical scheme, the present application improves the operation mode of the traditional process using inner filling support forming, and forms the expected flat surface effect by secondary flat processing of the curved surface, which has the following advantages:

[0019] 1) improve the processing quality: the formed plane of the produced parts is better, and the forming effect of the processing part is stable;

[0020] 2) Increased applicable scenarios: can effectively solve the problem that some complex parts cannot be machined due to small internal space and other reasons such as internal filling;

[0021] 3) Simple and easy to implement: the secondary processing method is relatively simple in mold preparation and manufacturing, and is easier to promote. BRIEF DESCRIPTION OF DRAWINGS

[0022] Figure 1 is a flow chart of the molding method of the present application;

[0023] Figure 2 is a structure schematic diagram of the primary stamping die of the present application;

[0024] Figure 3 is a structure schematic diagram of the secondary stamping die of the present application;

[0025] Figure 4 is a sectional view of Figure 2 ;

[0026] Figure 5 is a sectional view of Figure 3 . DETAILED DESCRIPTION

[0027] In order to make the technical means, creative features, purposes and effects of the present application easy to understand, the present application will be further described below in combination with specific drawings. It should be noted that the terms "first", "second", "third", "fourth" and the like (if any) in the specification and claims of the present application are used to distinguish similar objects, and do not necessarily mean a specific order or sequence. It should be understood that the data used in this way can be interchanged under appropriate circumstances, so that the embodiments described herein can be implemented in an order other than that illustrated or described herein. In addition, the terms "include" or "have" and any variations thereof are intended to cover non-exclusive inclusion, for example, a product or device including a series of component parts or units does not necessarily mean that it is limited to only those component parts or units clearly listed, but can include other component parts or units that are not clearly listed or inherent to these products or devices.

[0028] Referring to Figure 1 , Figure 2 , Figure 3A method and apparatus for forming a flat surface on a curved surface structure of a part, the forming apparatus comprising a primary forming die 100 and a secondary forming die 200. The primary forming die 100 comprises a primary forming upper die 101 and a primary forming lower die 102, and the secondary forming die 200 comprises a secondary forming upper die 201 and a secondary forming lower die 202. The primary forming upper die 101, the primary forming lower die 102 and the secondary forming lower die 202 each have a cavity, wherein the cavity of the primary forming upper die 101 is an upwardly concave structure on the lower end surface thereof, the cavities of the primary forming lower die 102 and the secondary forming lower die 202 are each a downwardly concave structure on the upper end surface thereof, and the concave structures of the three are each a concave curved surface. In addition, the opening width of the cavities of the primary forming lower die 102 and the secondary forming lower die 202 is less than the cross-sectional diameter of the part to be processed, wherein the cross-sectional diameter of the part to be processed refers to the diameter of a corresponding circle of the cross section of the pipe 300 to be processed.

[0029] It should be noted that the primary forming upper die and the secondary forming upper die correspond to the moving die during the first pressing and the second pressing, and the primary forming lower die and the secondary forming lower die correspond to the fixed die during the first pressing and the second pressing. When the part to be processed (the pipe) is subjected to the first pressing, the lower half of the pipe body is first placed in the cavity of the primary forming lower die, and the upper half thereof is exposed from the cavity. In order to meet the structural deformation requirement during processing, the center of the corresponding circle of the cross section of the pipe body is higher than the plane on which the opening of the cavity is located (i.e. the upper end surface of the primary forming lower die).

[0030] As shown in FIG. 1, the method for forming a flat surface on a curved surface structure of a part comprises the following steps: Figure 1

[0031] S1, preparation before the first pressing: the part to be processed is placed in the cavity of the primary forming lower die, so that the surface to be processed of the part to be processed is exposed from the cavity;

[0032] the surface to be processed of the part to be processed is exposed from the cavity;

[0033] S2, the first pressing: the surface to be processed of the part to be processed exposed from the cavity of the primary forming lower die is subjected to downward pressing by the primary forming upper die until the reserved height between the primary forming upper die and the primary forming lower die is between 1.0 mm and 2.5 mm;

[0034] the reserved height between the primary forming upper die and the primary forming lower die is between 1.0 mm and 2.5 mm;

[0035] S3, preparation before the second pressing: the part to be processed is placed in the cavity of the secondary forming lower die, so that the surface to be processed of the part to be processed is exposed from the cavity;

[0036] the surface to be processed of the part to be processed is exposed from the cavity;

[0037] ​S4, secondary stamping and shaping: the upper mold of the secondary forming is used to stamp the surface of the workpiece from top to bottom until the upper surface of the workpiece is a horizontal surface.

[0038] It should be noted that the present application is applicable to the processing of automobile parts, and the diameter of the pipe is generally between 5mm and 40mm, and the wall thickness is between 1.0mm and 2.0mm. Therefore, the reserved height is set to be between 1.0mm and 2.5mm, which can effectively cope with the processing of automobile parts. In the implementation process, the depth of the mold cavity / cavity of the primary forming lower mold can be set to the radius depth of the pipe.

[0039] In some embodiments, as shown in Figure 4 , the opening width of the cavity of the primary forming upper mold 101 is greater than the opening width of the cavity of the primary forming lower mold 102. For example, Figure 4 In the cross-sectional structure shown, the (downward) opening width of the cavity opening of the primary forming upper mold 101 can be greater than the (upward) opening width of the cavity opening of the primary forming lower mold 102.

[0040] In some embodiments, as shown in Figure 2 , Figure 4 , the inner concave surface of the cavity of the primary forming upper mold 101 is an arc curved surface, and in the cross section (cross section) of the cavity, the inner concave surface of the cavity corresponds to an arc segment.

[0041] In some preferred embodiments, as shown in Figure 2 , Figure 4 , the cavity of the primary forming upper mold 101 is an elliptical surface, the cross section of the cavity is a part of the structure of the elliptical shape with the long axis parallel to the horizontal plane, and the part of the structure is the local structure on the upper side of the long axis of the elliptical shape, and the bottom edge of the part of the structure is parallel to the long axis of the elliptical shape.

[0042] In some preferred embodiments, as shown in Figure 1 , Figure 2 , Figure 4 , in step 2), the reserved height between the primary forming upper mold 101 and the primary forming lower mold 102 is between 1.5mm and 2.5mm.

[0043] In the implementation of this invention, the primary stamping process uses a single-stage forming upper die with an arc-shaped concave cavity structure. This guides the deformation process of the outer wall of the pipe fitting, which gradually deforms towards a flat surface. Within the reserved height, sufficient deformation space is ensured for the secondary stamping. Traditional processing methods include single-stage stamping or multiple-stage stamping. The former is only suitable for parts with narrow processing surfaces or relatively flexible materials, while the latter not only increases the damage to the pipe fitting structure, but also, because the deformation of the outer wall of the part depends entirely on the shape and material characteristics of the part itself, the probability of deformed parts is relatively high, resulting in more defective products. In contrast, the processing equipment and corresponding processing method of this invention can not only complete the product forming in a smaller number of stamping steps, but also significantly improve the final forming quality in a single-stage forming process through the guiding effect of the upper die's stamping deformation.

[0044] In some embodiments, the lower end face of the secondary forming upper mold is rectangular, and the length of the rectangular structure is the same as the length of the surface to be processed of the part to be processed.

[0045] In some preferred embodiments, the width of the rectangular structure is smaller than the opening width of the cavity of the secondary forming lower die, so that the deformation of the part during the secondary stamping is not too constrained by the lower end face of the upper die, and the connection between the machined flat surface and the arc surface connected to it is smoother.

[0046] like Figure 3 , Figure 5 In the structure shown, the front and rear ends of the secondary forming upper die can be set as convex arc-shaped structures, so that when the tube is stamped and shaped in the secondary process, the deformation of the surface to be processed and the connecting structure of the tube body to which it is connected can be smoothed, thus avoiding the deformation of this part from causing the connection structure to become deformed.

[0047] In this invention, before stamping, both the primary forming upper die and the secondary forming upper die are fixed to the upper table of the press, while both the primary forming lower die and the secondary forming lower die are fixed to the lower table of the press. During preparation, all dies can be placed on the same press or on two separate presses.

[0048] The foregoing has shown and described the basic principles, main features, and advantages of the present invention. Those skilled in the art should understand that the present invention is not limited to the above embodiments. The embodiments and descriptions in the specification are merely illustrative of the principles of the invention. Various changes and modifications can be made to the invention without departing from its spirit and scope, and all such changes and modifications fall within the scope of the present invention as claimed. The scope of protection of this invention is defined by the appended claims and their equivalents.

Claims

1. A method of forming a flat surface on a curved surface structure of a part, characterized by, The application relates to a one-step forming die and a two-step forming die, wherein the one-step forming die comprises a one-step forming upper die and a one-step forming lower die, the two-step forming die comprises a two-step forming upper die and a two-step forming lower die, the one-step forming upper die, the one-step forming lower die and the two-step forming lower die have cavities, the opening width of the cavities of the one-step forming lower die and the two-step forming lower die is smaller than the cross-sectional diameter of a part to be processed, the inner concave surface of the cavity of the one-step forming upper die is an arc-shaped curved surface, and the inner concave surface of the cavity corresponds to an arc segment in the cross section of the cavity; the cross section of the cavity of the one-step forming upper die is a part of an elliptical structure with a long axis parallel to the horizontal plane, and the part is a local structure on the upper side of the long axis of the elliptical structure, and the bottom edge of the part is parallel to the long axis of the elliptical structure; the lower end surface of the two-step forming upper die is a rectangular structure, and the length of the rectangular structure is consistent with the length of the surface to be processed of the part to be processed; and the width of the rectangular structure is smaller than the opening width of the cavity of the two-step forming lower die. The application further relates to a method for processing a part, which comprises the following steps: 1) placing the part to be processed in the cavity of the one-step forming lower die so that the surface to be processed of the part to be processed is exposed to the cavity; 2) performing downward stamping on the surface to be processed of the part to be processed exposed to the cavity of the one-step forming lower die by the one-step forming upper die until the reserved height between the one-step forming upper die and the one-step forming lower die is between 1.0 mm and 2.5 mm; 3) placing the part to be processed in the cavity of the two-step forming lower die so that the surface to be processed of the part to be processed is exposed to the cavity; 4) performing downward stamping on the surface to be processed of the part to be processed exposed to the cavity of the two-step forming lower die by the two-step forming upper die until the upper surface of the part to be processed is a horizontal plane.

2. The method of claim 1, wherein The opening width of the cavity of the one-step forming upper die is greater than the opening width of the cavity of the one-step forming lower die.

3. The method of claim 1, wherein In the step 2), the reserved height between the one-step forming upper die and the one-step forming lower die is between 1.5 mm and 2.5 mm.

4. The method of claim 1 to 3, wherein The one-step forming lower die and the two-step forming lower die are fixed to the lower table of a press machine. The one-step forming upper die and the two-step forming upper die are fixed to the upper table of the press machine.

Images