Forming tool for hot end pipe fitting of automobile engine exhaust system

Abstract

The forming tool for the hot end pipe fitting of the automobile engine exhaust system comprises a bending die and a flaring die, and the bending die comprises a core die assembly, an upper bending die and a lower bending die; the flaring die comprises an upper flaring die, a lower flaring die and a male die assembly. The core die assembly supports the straight pipe fitting to be machined on the inner side, and it is guaranteed that the pipe fitting is kept stable in the bending process. The upper insert component and the lower insert component are respectively provided with an upper arc-shaped concave surface and a lower arc-shaped concave surface; the male die assembly is provided with an inner molded surface attached to the flaring working procedure piece. And the lower core mold assembly supports the bending working procedure piece on the inner side, and deformation or instability of the pipe fitting in the flaring process is prevented. The upper core mold assembly is provided with an outer molded surface attached to the flaring working procedure piece, and the shape and size precision of the flaring part is further ensured. Therefore, by means of segmented forming, the performance and reliability of the product are improved, and an efficient and reliable solution is provided for manufacturing of the hot end pipe fitting of the exhaust system of the automobile engine.

Description

Technical Field

[0001] The present invention relates to the technical field of automotive engine exhaust systems, and particularly to a forming tooling for hot-end pipe fittings of an automotive engine exhaust system. Background Art

[0002] The hot-end pipe fitting of an automotive engine exhaust system is a cross-section negative-angle end cone pipe, with the ratio of the large mouth diameter to the small mouth diameter exceeding twice, the mouth being eccentric, and being connected by an intermediate negative angle. Due to the design of the internal negative angle, special processes and technologies may be required in the actual forming process, and generally, the hydroforming process is used for manufacturing. The hydroforming process is a method of forming metal materials using liquid pressure. In this process, the liquid is usually water, and the material is gradually formed by applying pressure. However, during the hydroforming process, the material is stretched under high pressure, which will cause the thickness of the material to decrease. Due to the fluidity of the material and the limitations of process parameters, it is often difficult to control the wall thickness of the product. If the design angle of the product is small or has a relatively complex geometric shape, the material will become weaker in some areas, prone to instability, wrinkling or cracking. Some parts of the product may also show excessive deformation or uneven wall thickness.

[0003] When the hot-end pipe fitting of an automotive engine exhaust system is directly hydroformed using ordinary pipe fittings, the above problems will inevitably occur during the manufacturing process. This not only affects the appearance and dimensional accuracy of the product, but also leads to insufficient product performance, thereby affecting the stability of automotive use.

[0004] Therefore, the present invention needs to design a forming tooling for the hot-end pipe fitting of an automotive exhaust system. Summary of the Invention

[0005] In view of the above-mentioned disadvantages of the prior art, the purpose of the present invention is to provide a forming tooling for the hot-end pipe fitting of an automotive engine exhaust system. Under the premise of meeting the shape and size requirements, the problems of forming negative angles and large wall thickness reduction are solved.

[0006] To achieve the above purpose and other related purposes, the present invention provides a forming tooling for the hot-end pipe fitting of an automotive engine exhaust system, including:

[0007] A bending die, the bending die includes a core die assembly, an upper bending die and a lower bending die;

[0008] The core die assembly supports the straight pipe fitting to be processed on the inside;

[0009] The upper bending die includes an upper die block and an upper insert block assembly, the upper insert block assembly is installed on the upper die block and has an upper arc-shaped concave surface;

[0010] The bending lower die includes a lower die block and a lower insert block assembly. The lower insert block assembly is installed on the lower die block and has a lower arc concave surface. After the upper insert block assembly and the lower insert block assembly are combined, they have an inner profile surface that fits the known bent forming part of the bending workpiece.

[0011] A flaring die, which includes a flaring upper die, a flaring lower die, and a punch assembly.

[0012] The punch assembly has an inner profile surface that fits the known flared forming part of the flaring workpiece.

[0013] The flaring lower die includes a lower template II and a lower core die assembly. The lower core die assembly is installed on the lower template II, and the lower core die assembly supports the bending workpiece on the inner side.

[0014] The flaring upper die includes an upper template II and an upper core die assembly. The upper core die assembly is installed on the upper template II, and the upper core die assembly has an outer profile surface that fits the known flared forming part of the flaring workpiece.

[0015] In a preferred embodiment of the present invention, the upper insert block assembly includes a first upper insert block and a second upper insert block, the lower insert block assembly includes a first lower insert block and a second lower insert block, the core die assembly includes a first core die and a second core die. The first core die is cylindrical and supports the straight pipe to be processed on the inner side. The first upper insert block and the first lower insert block cooperate to bend and form the straight pipe to be processed into a bent pipe. The second core die has an inner profile surface that fits the known bent forming part of the bending workpiece and supports the bent pipe on the inner side. The second upper insert block and the second lower insert block cooperate to press and form the bent pipe to obtain the bending workpiece.

[0016] In a preferred embodiment of the present invention, the bending die further includes a lower template I, a first oil cylinder assembly, and a second oil cylinder assembly. The first oil cylinder assembly and the second oil cylinder assembly are respectively installed at both ends of the lower template I. The lower die block is installed in the middle of the lower template I. The driving end of the first oil cylinder assembly is respectively connected to the first ends of the first core die and the second core die through a first guide block. The driving end of the second oil cylinder assembly is connected to the second end of the first core die through a second guide block. The second end of the second core die is installed on the lower die block.

[0017] In a preferred embodiment of the present invention, the first oil cylinder assembly includes an oil cylinder assembly and a floating assembly. The floating assembly includes an oil cylinder fixing plate, a pair of oil cylinder brackets, and a nitrogen spring. The pair of oil cylinder brackets are vertically installed on the lower template I. The oil cylinder assembly is installed on the oil cylinder fixing plate. The oil cylinder fixing plate is slidably fitted between the pair of oil cylinder brackets, and the nitrogen spring is provided at the lower end of the oil cylinder fixing plate.

[0018] In a preferred embodiment of the present invention, the bending die further includes an upper template I and a pair of guide seats. The pair of guide seats are installed on the bottom surface of the upper template I, and the pair of guide seats and the pair of oil cylinder frames are arranged through a slide plate to achieve sliding fit.

[0019] In a preferred embodiment of the present invention, the punch assembly has a first inner surface and a second inner surface. The lower core die assembly includes a first lower core die and a second lower core die, and the upper core die assembly includes a first upper core die and a second upper core die; the first lower core die supports the bending workpiece on the inner side, the first upper core die and the first inner surface cooperate to process and form the bending workpiece to obtain a first flaring workpiece, the second lower core die supports the first flaring workpiece on the inner side, and the second upper core die and the second inner surface cooperate to process and form the first flaring workpiece to obtain a second flaring workpiece, that is, the flaring workpiece.

[0020] In a preferred embodiment of the present invention, the flaring die further includes a pair of cylinder assemblies. The punch assembly includes a first punch and a second punch. The first punch and the second punch are slidably arranged on the lower template II, and the driving ends of the pair of cylinder assemblies are respectively connected to the first punch and the second punch. When the first punch and the second punch are closed, the first inner surface and the second inner surface are formed.

[0021] In a preferred embodiment of the present invention, a pair of clamping seats are further arranged on the bottom surface of the upper template II. When the upper template II and the lower template II are closed, the pair of clamping seats are respectively located on the sides where the first punch and the second punch are away from each other.

[0022] In a preferred embodiment of the present invention, a guiding and supporting mechanism is arranged between the lower template II and the upper template II. The guiding and supporting mechanism includes at least two guide columns and guide sleeve assemblies.

[0023] In a preferred embodiment of the present invention, bulges are arranged on the outer walls of the first lower core die and the second lower core die, and notches are arranged on the bending workpiece to cooperate with the bulges.

[0024] The technical effect of the present invention is that: A forming tooling for a hot-end pipe fitting of an automobile engine exhaust system of the present invention includes two parts, namely a bending die and a flaring die.

[0025] The bending die solves the problems of uneven wall thickness and instability caused by poor material fluidity and process parameter limitations through the internal support of the core die assembly and the precise cooperation of the upper and lower insert assemblies. The arc-shaped concave surface design of the upper insert assembly and the lower insert assembly enables the material to be evenly stressed during the bending process, reducing local stress concentration and improving the forming accuracy and product consistency.

[0026] The punch assembly of the flaring die has an inner profile that fits the flaring workpiece, ensuring the shape accuracy of the flared part. The lower core die assembly supports the bending workpiece inside to prevent the pipe from deforming or becoming unstable during the flaring process; the upper core die assembly has an outer profile that fits the flaring workpiece, further ensuring the shape and dimensional accuracy of the flared part. It solves the problems of uneven wall thickness and excessive deformation caused by complex geometric shapes in the background technology, and effectively prevents the instability and rupture of the material during the flaring process.

[0027] Therefore, the present invention divides the forming process into two stages: bending and flaring. Specialized dies are used in each stage for step-by-step forming, avoiding the excessive stretching and deformation of the material caused by one-time forming in the background technology. It precisely controls the forming shape and reduces material waste. BRIEF DESCRIPTION OF THE DRAWINGS

[0028] In order to more clearly illustrate the technical solutions of the embodiments of the present invention, the following will briefly introduce the drawings required for describing the embodiments. Obviously, the drawings in the following description are only some embodiments of the present invention. For those of ordinary skill in the art, without creative efforts, other drawings can also be obtained based on these drawings.

[0029] Figure 1 Schematic structural diagram of the bending die provided by an embodiment of the present invention.

[0030] Figure 2 Schematic structural diagram of the upper bending die of the bending die provided by an embodiment of the present invention.

[0031] Figure 3 Schematic structural diagram of the lower bending die of the bending die provided by an embodiment of the present invention.

[0032] Figure 4 Schematic diagram of the lower module structure of the bending die provided by an embodiment of the present invention Figure 1 。

[0033] Figure 5 Schematic diagram of the lower module structure of the bending die provided by an embodiment of the present invention Figure 2 。

[0034] Figure 6 Schematic structural diagram of the flaring die provided by an embodiment of the present invention.

[0035] Figure 7Schematic diagram of the flaring upper die structure of the flaring die provided by an embodiment of the present invention.

[0036] Figure 8 Schematic diagram of the punch assembly structure of the flaring die provided by an embodiment of the present invention.

[0037] Figure 9 Schematic diagram of the flaring lower die structure of the flaring die provided by an embodiment of the present invention.

[0038] Figure 10 Schematic diagram of the upper core die assembly and the lower core die assembly structure of the flaring die provided by an embodiment of the present invention.

[0039] Figure 11 Schematic diagram of the straight pipe fitting to be processed provided by an embodiment of the present invention.

[0040] Figure 12 Schematic diagram of the bent pipe fitting provided by an embodiment of the present invention.

[0041] Figure 13 Schematic diagram of the press-bending workpiece provided by an embodiment of the present invention.

[0042] Figure 14 Schematic diagram of the flaring workpiece provided by an embodiment of the present invention.

[0043] Among them, the press-bending die 1; the core die assembly 11; the first core die 111; the second core die 112; the press-bending upper die 12; the upper die block 121; the upper insert block assembly 122; the first upper insert block 1221; the second upper insert block 1222; the press-bending lower die 13; the lower die block 131; the lower insert block assembly 132; the first lower insert block 1321; the second lower insert block 1322; the lower template I 14; the first oil cylinder assembly 15; the first guide block 150; the oil cylinder fixing plate 151; the oil cylinder frame 152; the second oil cylinder assembly 16; the second guide block 160; the upper template I 17; the guide seat 18;

[0044] The flaring die 2; the flaring upper die 21; the upper template II 211; the upper core die assembly 212; the first upper core die 2121; the second upper core die 2122; the flaring lower die 22; the lower template II 221; the lower core die assembly 222; the first lower core die 2221; the second lower core die 2222; the punch assembly 23; the first punch 231; the second punch 232; the cylinder assembly 24; the clamping seat 25; the guide post 261; the guide sleeve assembly 262; the straight pipe fitting to be processed 10; the press-bending workpiece 20; the bent pipe fitting 200; the flaring workpiece 30. Detailed implementation manners

[0045] The following describes the embodiments of the present invention through specific examples. Those skilled in the art can easily understand the other advantages and effects of the present invention from the content disclosed in this specification. The present invention can also be implemented or applied through other different specific embodiments. Various details in this specification can also be modified or changed based on different viewpoints and applications without departing from the spirit of the present invention. It should be noted that, without conflict, the following embodiments and the features in the embodiments can be combined with each other.

[0046] It should be noted that the diagrams provided in the following embodiments only illustrate the basic concept of the present invention in a schematic manner. Therefore, only the components related to the present invention are shown in the diagrams, rather than being drawn according to the number, shape, and size of the components in actual implementation. The type, quantity, and ratio of each component in actual implementation can be arbitrarily changed, and the component layout type may also be more complex.

[0047] Please refer to Figure 1 and Figure 2 , a forming tooling for a hot-end pipe fitting of an automotive engine exhaust system, including a bending die 1 and a flaring die 2. The bending die 1 includes a core die assembly 11, an upper bending die 12, and a lower bending die 13. The core die assembly 11 supports the straight pipe fitting 10 to be processed on the inner side. The upper bending die 12 includes an upper die block 121 and an upper insert block assembly 122. The upper insert block assembly 122 is installed on the upper die block 121 and has an upper arc-shaped concave surface. The lower bending die 13 includes a lower die block 131 and a lower insert block assembly 132. The lower insert block assembly 132 is installed on the lower die block 131 and has a lower arc-shaped concave surface. After the upper insert block assembly 122 and the lower insert block assembly 132 are combined, they have an inner surface that fits the known bent forming part of the bending workpiece 20.

[0048] Please refer to Figure 6 , the flaring die 2 includes an upper flaring die 21, a lower flaring die 22, and a punch assembly 23. The punch assembly 23 has an inner surface that fits the known flared forming part of the flaring workpiece 30. The lower flaring die 22 includes a lower template II 221 and a lower core die assembly 222. The lower core die assembly 222 is installed on the lower template II 221, and the lower core die assembly 222 supports the bending workpiece 20 on the inner side. The upper flaring die 21 includes an upper template II 211 and an upper core die assembly 212. The upper core die assembly 212 is installed on the upper template II 211, and the upper core die assembly 212 has an outer surface that fits the known flared forming part of the flaring workpiece 30.

[0049] It should be noted that both the bending die 1 and the flaring die 2 adopt a modular design. The bending die 1 is divided into a core die assembly 11, a bending upper die 12 and a bending lower die 13, and cooperates with an upper insert assembly 122 and a lower insert assembly 132 to form an inner profile that fits the known bending forming part. Such a design allows the mold to be flexibly adjusted to adapt to pipes of different shapes and sizes, significantly improving the forming accuracy and consistency. The flaring die 2 includes a flaring upper die 21, a flaring lower die 22 and a punch assembly 23, and the upper core die assembly 212 and the lower core die assembly 222 cooperate with the bending process part 20 to ensure that the outer profile of the flaring forming part fits perfectly with the workpiece. The modular design allows the two processes of flaring and bending to be seamlessly connected, reducing error accumulation.

[0050] Furthermore, the core mold parts in the bending die 1 and the flaring die 2 support the pipe fittings on the inside, effectively limiting the uneven stretching of the material during the forming process and maintaining the consistency of the wall thickness. The precise internal design of the upper insert assembly 122, the lower insert assembly 132 and the male mold assembly 23 ensures that the material is evenly distributed when subjected to force, reduces the phenomenon of local excessive thinness or thickness, reduces the risk of wrinkling and rupture, and improves the efficiency and quality of the production products.

[0051] See also Figures 3 - 5 In a preferred embodiment of the present invention, the upper insert assembly 122 includes a first upper insert 1221 and a second upper insert 1222, the lower insert assembly 132 includes a first lower insert 1321 and a second lower insert 1322, the core mold assembly 11 includes a first core mold 111 and a second core mold 112, the first core mold 111 is cylindrical and supports the straight pipe 10 to be processed on the inner side, the first upper insert 1221 and the first lower insert 1321 are used to bend the straight pipe 10 to be processed into a bent pipe 200; the second core mold 112 has an inner surface that fits the known bending forming part of the press-bending process part 20, and supports the bent pipe 200 on the inner side, the second upper insert 1222 and the second lower insert 1322 are used to press-form the bent pipe 200 to obtain the press-bending process part 20.

[0052] It should be noted that by dividing the upper insert component 122 and the lower insert component 132 into the first and second parts, namely the first upper insert 1221 and the second upper insert 1222, the first lower insert 1321 and the second lower insert 1322. The forming process at different stages can be precisely controlled, and the tooling can act on the workpiece at different forming stages respectively. For example, the first upper insert 1221 and the first lower insert 1321 are mainly used for the initial bending forming, while the second upper insert 1222 and the second lower insert 1322 are used for the pressure forming of the bent pipe fittings. This staged control can more precisely control the forming process and ensure that the pressure and deformation are evenly distributed in each stage. The segmented design makes the tooling more flexible in adapting to pipe fittings of different shapes and sizes. Different insert parts can be independently adjusted according to needs to adapt to diverse pipe fitting geometries and forming requirements.

[0053] Furthermore, the first core mold 111 supports the straight pipe fitting 10 to be processed at the initial stage, preventing the material from shrinking inward during the bending process, so as to keep the diameter and wall thickness of the pipe fitting consistent. The second core mold 112 continues to provide inner support after the bending is completed, preventing the material of the bent part from being over-stretched or locally thinned, and ensuring the stability of the shape and wall thickness after bending.

[0054] In a preferred embodiment of the present invention, the press-bending die 1 further includes a lower template I 14, a first oil cylinder assembly 15 and a second oil cylinder assembly 16. The first oil cylinder assembly 15 and the second oil cylinder assembly 16 are respectively installed at both ends of the lower template I 14, the lower module 131 is installed in the middle of the lower template I 14, the driving end of the first oil cylinder assembly 15 is respectively connected to the first ends of the first core mold 111 and the second core mold 112 through the first guide block 150, the driving end of the second oil cylinder assembly 16 is connected to the second end of the first core mold 111 through the second guide block 160, and the second end of the second core mold 112 is installed on the lower module 131.

[0055] It should be noted that the two-way control of the first oil cylinder assembly 15 and the second oil cylinder assembly 16 realizes synchronous action, which can drive the first core mold 111 and the second core mold 112, so that the first core mold 111 and the second core mold 112 are respectively inserted into the inner side of the pipe fitting from both ends, support and shape the pipe fitting on the inner side. Improve work efficiency and reduce the entire forming cycle.

[0056] Furthermore, the first guide block 150 and the second guide block 160 ensure the stable and accurate power transmission process of the oil cylinder, avoiding mechanical non-uniformity caused by offset. This helps to maintain symmetry during the press-bending process and ensure the geometric accuracy of the final product.

[0057] Please refer to Figure 3, in a preferred embodiment of the present invention, the first oil cylinder assembly 15 includes an oil cylinder assembly and a floating assembly. The floating assembly includes an oil cylinder fixing plate 151, a pair of oil cylinder frames 152 and nitrogen springs. The pair of oil cylinder frames 152 are vertically installed on the lower template I 14. The oil cylinder assembly is installed on the oil cylinder fixing plate 151. The oil cylinder fixing plate 151 is slidably disposed between the pair of oil cylinder frames 152, and a nitrogen spring is provided at the lower end of the oil cylinder fixing plate 151.

[0058] It should be noted that the oil cylinder fixing plate 151 can float downward along the height direction of the pair of oil cylinder frames 152, driving one end of the straight pipe fitting 10 to be processed to move downward. The other end of the straight pipe fitting 10 to be processed is relatively fixed through a pressing block and the first core mold 111. When one end of the straight pipe fitting 10 to be processed moves downward driven by the floating assembly, the side wall of the lower end of the processed straight pipe fitting 10 is pressed and bent into shape. When one end of the straight pipe fitting 10 to be processed is reset driven by the floating assembly, the first lower insert block 1321 floats up and ejects the bent pipe fitting 200. Therefore, the floating assembly not only supports one end of the straight pipe fitting 10 to be processed and meets the process steps of its downward pressing and forming, but also makes the bent pipe fitting 200 easy to demold and convenient to operate.

[0059] Furthermore, the first lower insert block 1321 can be elastically installed in the installation cavity of the lower module 131 through a nitrogen spring.

[0060] Please refer to Figure 2 , in a preferred embodiment of the present invention, the bending die 1 further includes an upper template I 17 and a pair of guide seats 18. The pair of guide seats 18 are installed on the bottom surface of the upper template I 17. The pair of guide seats 18 and the pair of oil cylinder frames 152 are arranged through a slide plate to achieve sliding fit.

[0061] It should be noted that the guide seats 18 provide a strong guiding effect for the die, reducing the risk of lateral offset caused by the misalignment of the die, ensuring that during the bending process, the straight pipe fitting 10 to be processed and the bent pipe fitting 200 can always be kept in the accurate position, thereby guaranteeing the accuracy of the geometric shape of the product.

[0062] Please refer to Figure 7 and Figure 8, in a preferred embodiment of the present invention, the punch assembly 23 has a first inner surface and a second inner surface. The lower core mold assembly 222 includes a first lower core mold 2221 and a second lower core mold 2222, and the upper core mold assembly 212 includes a first upper core mold 2121 and a second upper core mold 2122. The first lower core mold 2221 supports the bending workpiece 20 from the inside. The first upper core mold 2121 and the first inner surface cooperate to process and form the bending workpiece 20 to obtain the first flaring workpiece. The second lower core mold 2222 supports the first flaring workpiece from the inside. The second upper core mold 2122 and the second inner surface cooperate to process and form the first flaring workpiece to obtain the second flaring workpiece, i.e., the flaring workpiece 30.

[0063] It should be noted that the first upper core mold 2121, the first inner surface, the second upper core mold 2122 and the second inner surface cooperate to refine the implementation steps of the flaring process, ensuring that the force applied to the workpiece during the bending process is uniform and concentrated. After two flaring processes, it can ensure that the final shape of the workpiece is consistent with the design requirements, which is suitable for subsequent assembly or use. Moreover, one mold can achieve multiple processing forms. Through ingenious design, the versatility and adaptability of the mold are improved, and the first flaring workpiece and the second flaring workpiece, i.e., the flaring workpiece 30, can be processed simultaneously. The production process is integrated, the equipment usage and labor costs are reduced, and the economic benefits are improved. The design of two flarings also provides a more uniform material distribution, reduces defective products and waste caused by improper forming, improves the strength and fatigue resistance of the product, and shows better stability and durability in use.

[0064] Please refer to Figure 9 , in a preferred embodiment of the present invention, the flaring mold 2 further includes a pair of cylinder assemblies 24. The punch assembly 23 includes a first punch 231 and a second punch 232. The first punch 231 and the second punch 232 are slidably fitted on the lower template II 221. The driving ends of the pair of cylinder assemblies 24 are respectively connected to the first punch 231 and the second punch 232. When the first punch 231 and the second punch 232 are closed, the first inner surface and the second inner surface are formed.

[0065] It should be noted that the cylinder assembly 24, as a driving device, can quickly realize the closing and opening of the first punch 231 and the second punch 232, and can easily adjust the closing pressure of the first punch 231 and the second punch 232 through the cylinder to achieve processing more adaptable to diverse conditions.

[0066] In a preferred embodiment of the present invention, a pair of clamping seats 25 are further provided on the bottom surface of the upper template II 211. When the upper template II 211 and the lower template II 221 are closed, the pair of clamping seats 25 are respectively located on the sides of the first punch 231 and the second punch 232 that are away from each other.

[0067] It should be noted that when the first upper core die 2121 and the second upper core die 2122 move downward, the first punch 231 and the second punch 232 will be subjected to extrusion forces on both sides. To prevent the first punch 231 and the second punch 232 from moving away after being extruded, a pair of clamping seats 25 are respectively located on the sides where the first punch 231 and the second punch 232 are away from each other.

[0068] In a preferred embodiment of the present invention, a guiding and supporting mechanism is provided between the lower template II 221 and the upper template II 211. The guiding and supporting mechanism includes at least two guide posts 261 and a guide sleeve assembly 262.

[0069] It should be noted that two guide posts 261 and two guide sleeve assemblies 262 can be respectively provided at the diagonal corners of the lower template II 221 and the upper template II 211. The cooperation of the guide posts 261 and the guide sleeve assemblies 262 provides an accurate centering function, ensuring the precise matching between the lower template II 221 and the upper template II 211, effectively preventing the mold from deforming due to lateral forces or uneven pressures during the forming process, and reducing the defect rate caused by mold misalignment.

[0070] Please refer to Figure 10 , in a preferred embodiment of the present invention, bulges are provided on the outer walls of the first lower core die 2221 and the second lower core die 2222, and notches matching the bulges are provided on the bending workpiece 20.

[0071] It should be noted that the cooperation of the bulges and the notches can effectively align the core die and the workpiece, ensuring that the two components always maintain good positioning during the bending process, avoiding deviation and misalignment, thereby improving the accuracy of the forming process. Precise positioning also helps to reduce the dimensional fluctuations of the product, enabling each product to meet consistent quality standards and increasing the interchangeability of the finished products.

[0072] In summary, a forming tooling for a hot-end pipe fitting of an automobile engine exhaust system according to the present invention, when processing the hot-end pipe fitting of the automobile exhaust system, specifically includes the following steps: Please refer to Figures 11 - 14 .

[0073] Bending process: including a pressing and bending process and a bending and shaping process.

[0074] The straight pipe fitting 10 to be processed is a laser-cut pipe blank. The straight pipe fitting 10 to be processed is placed in the lower arc-shaped concave surface of the first lower insert 1321 of the bending die 1. The first oil cylinder assembly 15 and the second oil cylinder assembly 16 respectively push the first core die 111 and the second core die 112 into both ends of the straight pipe fitting 10 to be processed. The lower module 131 moves downward to close the mold. After the upper insert assembly 122 and the lower insert assembly 132 are combined, they have an inner profile;

[0075] Meanwhile, the upper template I 17 moves downward, driving the first oil cylinder assembly 15 (the oil cylinder assembly and the floating assembly) downward. The upper template I 17 presses on the oil cylinder fixing plate 151 to drive one end of the first core mold 111 downward. The first core mold 111 transmits force to act on the side wall of the corresponding end of the straight pipe fitting 10 to be processed, performing press forming and bending to obtain the bent pipe fitting 200. After the press forming and bending are completed, the upper template I 17 returns, and the first oil cylinder assembly 15 drives the first core mold 111 to reset. The first lower insert 1321 installed on the lower module 131 pops up to push out the bent pipe fitting 200, the two side oil cylinders retract, and the first core mold 111 withdraws;

[0076] Place the bent pipe fitting 200 into the lower arc concave surface of the second lower insert 1322. At the same time, place the laser cutting process part into the lower arc concave surface of the first lower insert 1321. Start the above steps. The second oil cylinder assembly 16 also drives and connects the second core mold 112. Therefore, the advancement of the second core mold 112 is carried out simultaneously with the press forming and bending process to further press and shape the bent pipe fitting 200 to obtain the press bending process part 20.

[0077] Flaring process: It includes the first flaring process and the second flaring process.

[0078] Place the press bending process part 20 on the first lower core mold 2221 of the flaring die 2. Through the cooperation of the bulge on the first lower core mold 2221 and the notch at the corresponding position of the press bending process part 20, the press bending process part 20 can be effectively positioned. At this time, the first punch 231 and the second punch 232 are closed to form the first inner surface and the second inner surface. The upper template II 211 presses downward, driving the first upper core mold 2121 downward. Under the combined action of the first upper core mold 2121 and the first inner surface, the first flaring of the press bending process part 20 is completed to obtain the first flaring process part.

[0079] Then place the first flaring process part on the second lower core mold 2222, and position and install it through the cooperation of the bulge on the second lower core mold 2222 and the notch at the corresponding position of the first flaring process part. At the same time, place a press bending process part 20 on the first lower core mold 2221. The first punch 231 and the second punch 232 are closed, and the second upper core mold 2122 and the second inner surface cooperate to process and form the first flaring process part to obtain the second flaring process part, that is, the flaring process part 30. The entire production process of the two flarings is completed. Then through the laser cutting process, the bulge on the flaring process part 30 is removed to obtain the final product.

[0080] The above embodiments are only illustrative of the principles and effects of the present invention and are not intended to limit the present invention. Any person familiar with this technology can modify or change the above embodiments without departing from the spirit and scope of the present invention. Therefore, all equivalent modifications or changes made by those with ordinary knowledge in the technical field without departing from the spirit and technical ideas disclosed by the present invention should still be covered by the claims of the present invention.

[0081] In the description herein, numerous specific details are provided, such as examples of components and / or methods, to provide a complete understanding of embodiments of the present invention. However, those skilled in the art will recognize that embodiments of the present invention may be practiced without one or more of the specific details or by other devices, systems, components, methods, parts, materials, articles, etc. In other instances, well-known structures, materials, or operations are not specifically shown or described in detail to avoid obscuring aspects of embodiments of the present invention.

[0082] Throughout the specification, reference to "an embodiment", "embodiments", or "specific embodiments" means that a particular feature, structure, or characteristic described in connection with the embodiments is included in at least one embodiment of the present invention and not necessarily in all embodiments. Thus, appearances of the phrases "in an embodiment", "in embodiments", or "in specific embodiments" in various places throughout the specification are not necessarily referring to the same embodiment. Additionally, the particular features, structures, or characteristics of any specific embodiment of the present invention may be combined in any suitable manner with one or more other embodiments. It is to be understood that other variations and modifications of the embodiments of the invention described and shown herein may be made in accordance with the teachings herein and will be considered part of the spirit and scope of the present invention.

[0083] It should also be understood that one or more of the elements shown in the figures may also be implemented in a more separated or more integrated manner, or even removed in some cases because they are inoperable or provided because they may be useful for a particular application.

[0084] Furthermore, unless otherwise explicitly specified, any marked arrows in the figures should be considered merely exemplary and not restrictive. Additionally, unless otherwise indicated, the term "or" as used herein generally intends to mean "and / or". Where the term is anticipated to be unclear due to the ability to provide separation or combination, the combination of components or steps will also be considered to have been specified.

[0085] As used in the description herein and throughout the claims below, unless otherwise indicated, "a", "an", and "the" include plural references. Similarly, as used in the description herein and throughout the claims below, unless otherwise indicated, the meaning of "in" includes "in" and "on".

[0086] The foregoing description of the embodiments shown in the present invention (including what is described in the abstract of the specification) is not intended to be exhaustive or to limit the invention to the precise forms disclosed herein. While specific embodiments of the invention and examples of the invention have been described herein for illustrative purposes only, various equivalent modifications will be apparent to and can be made by those skilled in the art within the spirit and scope of the invention. As noted, these modifications can be made to the invention in accordance with the foregoing description of the embodiments of the invention, and these modifications will be within the spirit and scope of the invention.

[0087] The systems and methods have been described generally herein to facilitate an understanding of the details of the invention. In addition, various specific details have been given to provide a general understanding of embodiments of the invention. However, those skilled in the relevant art will recognize that embodiments of the invention may be practiced without one or more of the specific details, or with other devices, systems, components, methods, materials, parts, etc. In other instances, well-known structures, materials, and / or operations have not been shown or described in detail to avoid obscuring aspects of the embodiments of the invention.

[0088] Accordingly, while the invention has been described herein with reference to its specific embodiments, modifications, various changes and substitutions are also within the foregoing disclosure, and it should be understood that in some instances, some features of the invention may be employed without a corresponding use of other features without departing from the scope and spirit of the claimed invention. Accordingly, many modifications may be made to adapt a particular environment or material to the essential scope and spirit of the invention. The invention is not intended to be limited to the specific terms and / or the specific embodiments disclosed as the best mode contemplated for carrying out the invention, but the invention will include any and all embodiments and equivalents falling within the scope of the appended claims. Accordingly, the scope of the invention will be determined only by the appended claims.

Claims

1. A forming tool for hot end pipe fittings of automobile engine exhaust system, characterized in that: include: A bending die (1), the bending die (1) comprising a core die assembly (11), an upper bending die (12) and a lower bending die (13); The core mold assembly (11) supports the straight pipe piece (10) to be processed on the inner side; The bending upper die (12) comprises an upper die block (121) and an upper insert block assembly (122); the upper insert block assembly (122) is mounted on the upper die block (121) and has an upper arc-shaped concave surface; The press-bending lower die (13) comprises a lower die block (131) and a lower insert assembly (132); the lower insert assembly (132) is mounted on the lower die block (131) and has a lower arc-shaped concave surface; the upper insert assembly (122) and the lower insert assembly (132) are combined to have an inner profile that fits with a known bending forming portion of the press-bending process part (20); A flaring die (2), wherein the flaring die (2) comprises an flaring upper die (21), a flaring lower die (22) and a male die assembly (23); The male mold assembly (23) has an inner mold surface that fits with the known expansion forming part of the expansion process part (30); The flaring lower die (22) comprises a lower die plate II (221) and a lower core die assembly (222), wherein the lower core die assembly (222) is mounted on the lower die plate II (221), and the lower core die assembly (22) supports the bending process part (20) on the inner side; The flaring upper die (21) comprises an upper die plate II (211) and an upper core die assembly (212). The upper core die assembly (212) is mounted on the upper die plate II (211). The upper core die assembly (212) has an outer profile that fits with a known flaring forming portion of the flaring process part (30).

2. The forming tool for the hot end pipe of the automobile engine exhaust system according to claim 1 is characterized in that: The upper insert assembly (122) comprises a first upper insert (1221) and a second upper insert (1222); the lower insert assembly (132) comprises a first lower insert (1321) and a second lower insert (1322); the core mold assembly (11) comprises a first core mold (111) and a second core mold (112); the first core mold (111) is cylindrical and supports the straight pipe (10) to be processed on the inner side; the first upper insert (1221) and the first The lower insert (1321) is used to bend and form the straight pipe (10) to be processed into a bent pipe (200); the second core mold (112) has an inner surface that fits the known bending forming part of the bending process part (20) and supports the bent pipe (200) on the inner side; the second upper insert (1222) and the second lower insert (1322) are used to press and form the bent pipe (200) to obtain the bending process part (20).

3. The forming tool for the hot end pipe of the automobile engine exhaust system according to claim 2 is characterized in that: The press-bending die (1) further comprises a lower die plate I (14), a first cylinder assembly (15) and a second cylinder assembly (16), wherein the first cylinder assembly (15) and the second cylinder assembly (16) are respectively mounted at two ends of the lower die plate I (14), and the lower die block (131) is mounted in the middle of the lower die plate I (14). The driving end of the first cylinder assembly (15) is respectively connected to the first ends of the first core die (111) and the second core die (112) via a first guide block (150), and the driving end of the second cylinder assembly (16) is connected to the second end of the first core die (111) via a second guide block (160), and the second end of the second core die (112) is mounted on the lower die block (131).

4. The forming tool for the hot end pipe of the automobile engine exhaust system according to claim 3 is characterized in that: The first cylinder assembly (15) comprises a cylinder assembly and a floating assembly, wherein the floating assembly comprises a cylinder fixing plate (151), a pair of cylinder frames (152) and a nitrogen spring, wherein the pair of cylinder frames (152) are vertically mounted on the lower template I (14), and the cylinder assembly is mounted on the cylinder fixing plate (151), wherein the cylinder fixing plate (151) is slidably mounted between the pair of cylinder frames (152), and the nitrogen spring is disposed at the lower end of the cylinder fixing plate (151).

5. The forming tool for the hot end pipe of the automobile engine exhaust system according to claim 4, characterized in that: The bending die (1) also includes an upper die plate I (17) and a pair of guide seats (18), wherein the pair of guide seats (18) are installed on the bottom surface of the upper die plate I (17), and the pair of guide seats (18) and the pair of cylinder frames (152) are arranged via a slide plate to achieve sliding fit.

6. The forming tool for the hot end pipe of the automobile engine exhaust system according to claim 5, characterized in that: The punch assembly (23) has a first inner profile and a second inner profile, the lower core mold assembly (222) includes a first lower core mold (2221) and a second lower core mold (2222), and the upper core mold assembly (212) includes a first upper core mold (2121) and a second upper core mold (2122); the first lower core mold (2221) supports the bending process part (20) on the inner side, the first upper core mold (2121) and the first inner profile cooperate to form the bending process part (20) to obtain a first expansion process part, the second lower core mold (2222) supports the first expansion process part on the inner side, the second upper core mold (2122) and the second inner profile cooperate to form the first expansion process part to obtain a second expansion process part, i.e., an expansion process part (30).

7. The forming tool for the hot end pipe of the automobile engine exhaust system according to claim 6, characterized in that: The expansion mold (2) also includes a pair of cylinder assemblies (24), and the punch assembly (23) includes a first punch (231) and a second punch (232). The first punch (231) and the second punch (232) are slidably fitted on the lower mold plate II (221). The driving ends of the pair of cylinder assemblies (24) are respectively connected to the first punch (231) and the second punch (232). When the first punch (231) and the second punch (232) are molded together, the first inner surface and the second inner surface are formed.

8. The forming tool for the hot end pipe of the automobile engine exhaust system according to claim 7, characterized in that: A pair of clamping seats (25) are also provided on the bottom surface of the upper template II (211). When the upper template II (211) and the lower template II (221) are molded together, the pair of clamping seats (25) are respectively located on the side of the first punch (231) and the second punch (232) that are away from each other.

9. The forming tool for the hot end pipe of the automobile engine exhaust system according to claim 8, characterized in that: A guide support mechanism is provided between the lower template II (221) and the upper template II (211), and the guide support mechanism comprises at least two guide pillars (261) and a guide sleeve assembly (262).

10. The forming tool for the hot end pipe of the automobile engine exhaust system according to claim 9, characterized in that: The outer walls of the first lower core mold (2221) and the second lower core mold (2222) are both provided with bulges, and the bending process part (20) is provided with notches that cooperate with the bulges.

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