A sealing assembly and hot gas inflation process

Abstract

This invention discloses a sealing assembly and a thermal expansion process. The sealing assembly includes: a plugging member with a protrusion on its outer side; and a connector for mounting at the end of a processed pipe fitting, the connector having a plug-in end for inserting the plugging member. The inner wall of the plug-in end of the connector has a groove for engaging with the protrusion. When the plugging member is inserted into the plug-in end of the connector, the groove is formed by the protrusion of the plugging member pressing against the inner wall of the plug-in end of the connector. The sealing assembly provided by this invention, by providing a protrusion on the outer side of the plugging member and utilizing the characteristic that the connector is prone to deformation under high temperatures, allows the protrusion of the plugging member to press against the inner wall of the plug-in end of the connector when the plugging member is inserted, forming a groove. This achieves a sealing effect through the interlocking of the protrusion and the groove, thereby improving the sealing performance in the thermal expansion process.

Description

Technical Field

[0001] This invention relates to the field of hollow component processing technology, and more specifically, to a sealing assembly and a thermal expansion process. Background Technology

[0002] Lightweight vehicle body construction is a crucial technological direction for energy conservation and emission reduction in the automotive industry. Lightweight technology is a fundamental and common technology for both traditional and new energy vehicles, and using a hollow body structure is one of the effective ways to achieve this. Air forming is an advanced manufacturing technology for creating hollow integral components. Using this process, the strength of materials can be increased to over 1500 MPa, and the axis path can be defined according to the vehicle body structure design and collision requirements, reducing the blind spot angle of the A-pillar and significantly reducing weight. In the air forming process, it is essential to ensure the sealing of the forming process; any air leakage at the tube end will lead to forming failure or defects in product dimensional accuracy.

[0003] In existing technologies, the insertion and compression sealing method is generally used. This method requires high hardness of the sealing plug. The sealing is achieved by interference fit between the sealing plug and the connecting parts of the processed pipe (hereinafter referred to as pipe unless otherwise specified). However, this method is prone to deformation due to the high temperature of the processed pipe and connecting parts, resulting in poor sealing effect and easy failure of expansion.

[0004] Furthermore, the insertion-extrusion sealing method makes the sealing plug prone to wear during the extrusion and expansion of the tube end. Also, because the tube is processed at high temperatures during the air expansion process, the tube undergoes thermal expansion and contraction after in-mold quenching, causing the tube end to tightly wrap around the sealing plug, making demolding very difficult and easily breaking the sealing part. Simultaneously, since the seal is achieved through extrusion on the inner wall of the tube end, the positioning of the tube on the expansion mold is crucial. The lack of obvious shaped surfaces and holes for positioning makes it prone to incomplete sealing and air leakage, leading to expansion failure.

[0005] Therefore, how to improve the sealing performance in the air-inflating process has become a technical problem that urgently needs to be solved by those skilled in the art. Summary of the Invention

[0006] In view of this, the object of the present invention is to provide a sealing component to improve the sealing performance in the gas-forming process.

[0007] Another object of the present invention is to provide a thermal expansion process using the above-described sealing assembly.

[0008] To achieve the above objectives, the present invention provides the following technical solution:

[0009] A sealing assembly for a thermal expansion process, comprising:

[0010] A sealing element, wherein a protrusion is provided on the outer side of the sealing element;

[0011] A connector is provided at the end of a processed pipe fitting, and the connector has a plug end for inserting the plug. The inner wall of the plug end of the connector is provided with a groove for engaging with the protrusion. When the plug is inserted into the plug end of the connector, the groove is formed by the protrusion of the plug pressing against the inner wall of the plug end of the connector.

[0012] Optionally, in the above-mentioned sealing assembly, the plug end of the connector is provided with a flared opening, and the sealing member is provided with a conical inclined surface that fits against the inner wall of the flared opening. The protrusion is circumferentially disposed on the conical inclined surface of the sealing member, and the groove is located on the inner wall of the flared opening.

[0013] Optionally, in the sealing assembly described above, the angle between the generatrix of the flared opening of the connector and the axis of the flared opening is 45°, and the protrusion is a stepped structure disposed on the conical inclined surface.

[0014] Optionally, in the above-described sealing assembly, the connector is a transition pipe extending from the processed pipe, and the connector and the processed pipe are integrally formed.

[0015] Optionally, in the above-mentioned sealing assembly, the sealing member is provided with a through hole for injecting high-pressure gas flow.

[0016] A hot gas expansion process, wherein the hot gas expansion process employs a sealing component as described in any of the preceding claims, the hot gas expansion process comprising the steps of:

[0017] The mold is closed, and the processed pipe fitting connected to the connector is placed inside the mold;

[0018] The sealing element is inserted into the plug end of the connector, and the protrusion of the sealing element mates with the groove on the inner wall of the plug end of the connector to form a sealed tube.

[0019] Hot gas expansion is achieved by injecting high-pressure airflow into the sealing pipe through a through hole in the sealing component using an expansion device, thereby forming an expanded pipe.

[0020] Optionally, in the above-mentioned hot air expansion process, the plug end of the connector is provided with a funnel-shaped opening, and the sealing member is provided with a conical inclined surface that fits against the inner wall of the funnel-shaped opening, and the protrusion is provided circumferentially on the conical inclined surface of the sealing member.

[0021] Optionally, in the above-described hot air expansion process, during the sealing step, the sealing member is inserted into the funnel-shaped opening of the connector, causing the protrusion of the sealing member to press against the inner wall of the funnel-shaped opening to form an annular groove that mates with the protrusion.

[0022] Optionally, the above-described hot gas expansion process further includes the following steps:

[0023] Laser cutting involves placing the bulging tube on a laser cutting fixture. The bulging tube includes a bulged processed tube and a connector connected to the end of the processed tube. A laser cutting machine cuts at the connection point between the connector and the processed tube to form the finished tube.

[0024] Optionally, in the above-mentioned hot air expansion process, the laser cutting fixture is provided with a mating surface that matches the flared opening of the connector.

[0025] The sealing assembly provided by the present invention provides a protrusion on the outside of the sealing member. Since the processing pipe and the connector located at the end of the processing pipe are in a high temperature state, when the sealing member is inserted into the insertion end of the connector, the protrusion of the sealing member squeezes the inner wall of the insertion end of the connector to form a groove, so that the groove and the protrusion interlock with each other, thereby achieving a seal on the processing pipe.

[0026] Compared with the insertion and compression sealing method in the prior art, the sealing component provided by the present invention provides a protrusion on the outside of the sealing member. Taking advantage of the fact that the connector is prone to deformation under high temperature, when the sealing member is inserted into the insertion end of the connector, the protrusion of the sealing member compresses the inner wall of the insertion end of the connector to form a groove, thereby achieving a sealing effect of interlocking between the protrusion and the groove, thus improving the sealing performance in the air expansion molding process. Attached Figure Description

[0027] To more clearly illustrate the technical solutions in the embodiments of this application or the prior art, the drawings used in the description of the embodiments or the prior art will be briefly introduced below. Obviously, the drawings described below are only embodiments of this application. For those skilled in the art, other drawings can be obtained based on the provided drawings without creative effort.

[0028] Figure 1 This is a schematic diagram of the sealing assembly provided in an embodiment of the present invention;

[0029] Figure 2 This is a schematic diagram of the structure of the sealing component and the connecting component in accordance with an embodiment of the present invention;

[0030] Figure 3 This is a schematic diagram of the pre-formed state in the hot air expansion process provided in an embodiment of the present invention;

[0031] Figure 4 This is a schematic diagram of mold closing during the hot air expansion process provided in an embodiment of the present invention;

[0032] Figure 5 This is a schematic diagram of the sealing process in the thermal expansion process provided in an embodiment of the present invention;

[0033] Figure 6 This is a schematic diagram of the hot gas expansion process provided in an embodiment of the present invention;

[0034] Figure 7 A schematic flowchart of the thermal expansion process provided in this embodiment of the invention. Figure 1 ;

[0035] Figure 8 A schematic flowchart of the thermal expansion process provided in this embodiment of the invention. Figure 2 .

[0036] Among them, 100 is a sealing component, 101 is a conical inclined surface, 102 is a protrusion, 200 is a connecting component, 201 is a trumpet-shaped opening, and 202 is a groove. Detailed Implementation

[0037] The core of this invention is to provide a sealing component to improve the sealing performance in the air-expansion molding process.

[0038] Another key aspect of this invention is to provide a thermal expansion process using the aforementioned sealing components.

[0039] The technical solutions of the embodiments of this application will be clearly and completely described below with reference to the accompanying drawings. Obviously, the described embodiments are only some embodiments of this application, and not all embodiments. Based on the embodiments of this application, all other embodiments obtained by those skilled in the art without creative effort are within the scope of protection of this application.

[0040] like Figure 1As shown, this embodiment of the invention discloses a sealing assembly, including a sealing element 100 and a connecting element 200. It should be noted that the sealing assembly disclosed in this embodiment is mainly used in the sealing step of a hot gas expansion process. In the prior art, sealing in a hot gas expansion process generally adopts an insertion-compression sealing method. This method requires high hardness of the sealing element, and sealing is achieved through an interference fit between the sealing element and the connecting element of the processed pipe (hereinafter referred to as the pipe unless otherwise specified). However, this method is prone to deformation due to the high temperature of the processed pipe and the connecting element, resulting in poor sealing effect and easy expansion failure. Furthermore, the insertion-compression sealing method makes the sealing element prone to wear when compressing the end of the expanded pipe. Also, because the processed pipe is at a high temperature during the gas expansion process, the pipe undergoes thermal expansion and contraction after in-mold quenching after sealing, causing the end of the pipe to tightly wrap around the sealing element, making demolding very difficult and easily breaking the sealing part of the pipe. Meanwhile, since sealing is achieved by compressing the inner wall of the pipe end, the positioning of the pipe on the expansion mold is critical. Furthermore, the pipe lacks a clear surface and holes for positioning, making it prone to incomplete sealing and air leakage, leading to expansion failure. The sealing assembly disclosed in this embodiment of the invention, by providing a protrusion 102 on the outer side of the sealing member 100, utilizes the characteristic that the connector is prone to deformation under high temperatures. When the sealing member 100 is inserted into the insertion end of the connector 200, the protrusion 102 of the sealing member 100 compresses the inner wall of the insertion end of the connector 200 to form a groove 202, thereby achieving a sealing effect through the interlocking of the protrusion 102 and the groove 202, thus improving the sealing performance in the air expansion molding process. Meanwhile, by setting a diffused mold surface, i.e. a trumpet-shaped opening in the embodiment of the invention, at the insertion end of the connector 200, and cooperating with a sealing component 100 with a tapered inclined surface, the demolding difficulty of the sealing component 100 after in-mold quenching is reduced, the wear of the sealing component 100 is reduced, and it can be used with a mold and laser cutting fixture corresponding to the trumpet-shaped opening to achieve precise positioning and cutting, thus ensuring the stability of the hot gas expansion process.

[0041] The sealing member 100 has a protrusion 102 on its outer side and a through hole on it, so that the air expansion device can inject high-pressure airflow into the processed pipe through the through hole to expand it. Meanwhile, the connector 200 is located at the end of the processed pipe and has a plug-in end for the sealing member 100 to be inserted into. The inner wall of the plug-in end of the connector 200 has a groove 202 that mates with the protrusion 102. When the sealing member 100 is inserted into the plug-in end of the connector 200, the groove 202 is formed by the protrusion 102 of the sealing member 100 pressing against the inner wall of the plug-in end of the connector 200. Specifically, the connector 200 is a transition pipe extending from the processed pipe to reserve sufficient sealing section for the processed pipe, while making the transition of the sealing section to the regular process end face smoother. The connector 200 and the processed pipe are integrally formed, or they can be a separate structure. The connector 200 and the processed pipe are connected by a detachable connection.

[0042] In one specific embodiment, the protrusions 102 can be spaced apart along the circumferential direction, or they can be continuously arranged along the circumferential direction. Those skilled in the art will understand that, compared to the method of spaced protrusions 102 along the circumferential direction, the method of continuously arranged protrusions 102 along the circumferential direction results in a larger engagement area between the protrusions 102 and the grooves 202, leading to a better sealing effect. In this embodiment, to further increase the sealing performance of the processed pipe fitting, the protrusions 102 are arranged continuously along the circumferential direction. When sealing the processed pipe fitting, since the processed pipe fitting and the connector 200 located at the end of the processed pipe fitting are in a high temperature state after the pre-forming step is completed, when the sealing member 100 is inserted into the insertion end of the connector 200, the protrusion 102 of the sealing member 100 squeezes the inner wall of the insertion end of the connector 200 to form an annular groove, so that the groove 202 and the protrusion 102 interlock with each other, thereby achieving the sealing of the processed pipe fitting. Compared with the traditional insertion and compression sealing method, the interlocking of the groove 202 and the protrusion 102 improves the sealing effect of the connector 200, thereby improving the sealing performance of the processed pipe fitting and ensuring the stability of the air expansion molding process.

[0043] The sealing assembly provided by the present invention provides a protrusion 102 on the outer side of the sealing member 100. Since the processing pipe and the connector 200 located at the end of the processing pipe are in a high temperature state, when the sealing member 100 is inserted into the insertion end of the connector 200, the protrusion 102 of the sealing member 100 squeezes the inner wall of the insertion end of the connector 200 to form a groove 202, so that the groove 202 and the protrusion 102 interlock with each other, thereby achieving a seal on the processing pipe.

[0044] Compared with the insertion and compression sealing method in the prior art, the sealing assembly provided by the present invention provides a protrusion 102 on the outer side of the sealing member 100. Taking advantage of the fact that the connector 200 is prone to deformation under high temperature, when the sealing member 100 is inserted into the insertion end of the connector 200, the protrusion 102 of the sealing member 100 compresses the inner wall of the insertion end of the connector 200 to form a groove 202, thereby achieving a sealing effect of interlocking between the protrusion 102 and the groove 202, and thus improving the sealing performance in the air expansion molding process.

[0045] Furthermore, such as Figure 1 and Figure 2 As shown, in one specific embodiment, a flared opening 201 is provided at the insertion end of the connector 200, and a tapered inclined surface 101 that fits against the inner wall of the flared opening 201 is provided on the sealing member 100. A protrusion 102 is circumferentially disposed on the tapered inclined surface 101 of the sealing member 100, and a groove 202 is located on the inner wall of the flared opening 201. Specifically, the angle between the generatrix of the flared opening 201 of the connector 200 and the axis of the flared opening 201 is 45°. This ensures a large opening angle for easy demolding while also ensuring the engagement surface between the protrusion 102 and the groove 202 formed on the inner wall of the flared opening 201. The protrusion 102 is a stepped structure disposed on the tapered inclined surface 101. Those skilled in the art will understand that the larger the opening angle of the trumpet-shaped opening 201 of the connector 200, i.e., the larger the angle between the generatrix of the trumpet-shaped opening 201 and the axis of the trumpet-shaped opening 201, the easier the demolding is. However, to achieve the desired sealing effect, the sealing component 100 also needs to be increased in size, resulting in higher costs for the sealing assembly and thus increasing the cost of the thermal expansion process. Conversely, the smaller the opening angle of the trumpet-shaped opening 201 of the connector 200, i.e., the smaller the angle between the generatrix of the trumpet-shaped opening 201 and the axis of the trumpet-shaped opening 201, the more difficult the demolding is, leading to more severe wear on the sealing component 100. It should be noted that... Figure 2 The groove 202 is defined relative to the inner wall of the trumpet-shaped opening 201. From the outer perspective of the trumpet-shaped opening 201, it is the rib protruding towards the outer wall of the trumpet-shaped opening 201 in the figure.

[0046] This invention also discloses a hot gas expansion process, and the sealing component used in the hot gas expansion process is the sealing component disclosed in the above embodiments. Therefore, it possesses all the technical effects of the aforementioned sealing components, and will not be repeated here. It should be noted that the hot gas expansion process disclosed in this invention mainly refers to the process steps after pre-forming the pipe fittings and connectors in the hot gas expansion process. The process steps before and after pre-forming in the hot gas expansion process are not the inventive points of this invention, and will not be explained or described here. Wherein, as... Figure 7 As shown, the hot air expansion process includes:

[0047] Step S100: Mold closing;

[0048] like Figure 3 and Figure 4 As shown, a processed pipe fitting connected to a connector 200 is placed inside a mold. Specifically, the insertion end of the connector 200 is provided with a flared opening 201, and the mold includes a first mold and a second mold. Both the first and second molds have mating surfaces that mate with the flared opening 201. When the processed pipe fitting connected to the connector 200 is placed on the first mold, simply align the flared opening 201 of the connector 200 with the mating surface of the first mold. Then, snap the mating surface of the second mold onto the flared opening 201 of the connector 200 to complete mold closing. By providing a mating surface on the mold that mates with the flared opening 201 of the connector 200, the problem of poor positioning accuracy of the processed pipe fitting inside the mold is solved, effectively avoiding flash during mold closing and misalignment of the processed pipe fitting. It should be noted that in this embodiment, the mold and the funnel-shaped opening 201 of the connector 200 are not tightly fitted. A certain gap is left between the mating surfaces of the mold and the funnel-shaped opening 201 of the connector 200 to provide deformation space for the thermal expansion of the connector 200.

[0049] Step S101, seal;

[0050] like Figure 5 As shown, after the S100 mold closing step is completed, the sealing member 100 is inserted into the insertion end of the connector 200. The protrusion 102 of the sealing member 100 engages with the groove on the inner wall of the insertion end of the connector 200 to form a sealed tube. Specifically, the sealing member 100 is provided with a tapered inclined surface 101 that fits against the inner wall of the flared opening 201, and the protrusion 102 is arranged circumferentially on the tapered inclined surface 101 of the sealing member 100. Since the processed tube and the connector 200 located at the end of the processed tube are in a high-temperature state after the pre-forming step, when the sealing member 100 is inserted into the flared opening 201 of the connector 200, the protrusion 102 of the sealing member 100 squeezes the inner wall of the flared opening 201 to form an annular groove that engages with the protrusion 102, so that the annular groove and the protrusion 102 interlock, thereby achieving a seal on the processed tube.

[0051] Step S102, hot air expansion;

[0052] like Figure 6 As shown, a high-pressure airflow is injected into the sealing pipe through a through hole provided on the sealing component 100 using an air expansion device to form an expanded pipe. It should be noted that the high-pressure airflow generally uses an expansion pressure of 50 MPa to 70 MPa.

[0053] Furthermore, in one specific embodiment, such as Figure 8 As shown, the hot gas expansion process also includes:

[0054] Step S103, laser cutting;

[0055] The expanded tube is placed on a laser cutting fixture. The expanded tube includes a bulged, processed tube and a connector 200 attached to the end of the processed tube. A laser cutting machine cuts at the connection point between the connector 200 and the processed tube to form the finished tube. Specifically, the laser cutting fixture has a mating surface that matches the flared opening 201 of the connector 200, allowing for precise positioning of the expanded tube by the laser cutting fixture. Simultaneously, the flared opening 201 of the connector 200 provides a reference position for the laser cutting machine.

[0056] The terms "first" and "second," etc., in the specification, claims, and accompanying drawings of this invention are used to distinguish different objects, not to describe a specific order. Furthermore, the terms "comprising" and "having," and any variations thereof, are intended to cover non-exclusive inclusion. For example, a process, method, system, product, or apparatus that includes a series of steps or units may include steps or units not listed, but rather steps or units not listed.

[0057] The above description of the disclosed embodiments enables those skilled in the art to make or use the invention. Various modifications to these embodiments will be readily apparent to those skilled in the art, and the general principles defined herein may be implemented in other embodiments without departing from the spirit or scope of the invention. Therefore, the invention is not to be limited to the embodiments shown herein, but is to be accorded the widest scope consistent with the principles and novel features disclosed herein.

Claims

1. A sealing assembly for a thermal expansion process, characterized in that, include: A sealing member (100) has a protrusion (102) on its outer side. A connector (200) is provided at the end of a processed pipe fitting, and the connector (200) has a plug end for the plug (100) to be inserted into. The inner wall of the plug end of the connector (200) is provided with a groove (202) for cooperating with the protrusion (102). When the plug (100) is inserted into the plug end of the connector (200), the groove (202) is formed by the protrusion (102) of the plug (100) pressing the inner wall of the plug end of the connector (200). The connector (200) has a flared opening (201) at its insertion end, and the sealing member (100) has a tapered inclined surface (101) that fits against the inner wall of the flared opening (201). The protrusion (102) is arranged circumferentially on the tapered inclined surface (101) of the sealing member (100), and the groove (202) is located on the inner wall of the flared opening (201). Taking advantage of the fact that the connector is still in the plastic deformation temperature range and is prone to deformation after the preforming step is completed and before hot air expansion, when the sealing part (100) is inserted into the insertion end of the connector (200), the protrusion (102) of the sealing part (100) squeezes the inner wall of the insertion end of the connector (200) to form the groove (202), thereby achieving the sealing effect of the protrusion (102) and the groove (202) interlocking with each other.

2. The sealing assembly according to claim 1, characterized in that, The angle between the generatrix of the flared opening (201) of the connector (200) and the axis of the flared opening (201) is 45°, and the protrusion (102) is a stepped structure provided on the conical inclined surface (101).

3. The sealing assembly according to claim 1, characterized in that, The connector (200) is a transition pipe extending from the processed pipe, and the connector (200) and the processed pipe are integrally formed.

4. The sealing assembly according to claim 1, characterized in that, The sealing component (100) has a through hole for injecting high-pressure gas flow.

5. A thermal expansion process, characterized in that, The thermal expansion process employs the sealing component as described in any one of claims 1-4, and the thermal expansion process includes the following steps: Close the mold and place the processed pipe fitting connected to the connector (200) into the mold; To seal, the sealing member (100) is inserted into the plug end of the connector (200), and the protrusion (102) of the sealing member (100) is engaged with the groove on the inner wall of the plug end of the connector (200) to form a sealed tube. Hot gas expansion is performed by injecting high-pressure airflow into the sealing pipe through a through hole provided on the sealing member (100) using an air expansion device to form an expanded pipe.

6. The thermal expansion process according to claim 5, characterized in that, The connector (200) has a flared opening (201) at its insertion end, and the sealing member (100) has a tapered inclined surface (101) that fits against the inner wall of the flared opening (201). The protrusion (102) is arranged circumferentially on the tapered inclined surface (101) of the sealing member (100).

7. The thermal expansion process according to claim 6, characterized in that, In the sealing step, by inserting the sealing member (100) into the funnel-shaped opening (201) of the connector (200), the protrusion (102) of the sealing member (100) presses against the inner wall of the funnel-shaped opening (201) to form an annular groove that mates with the protrusion (102).

8. The thermal expansion process according to claim 6, characterized in that, It also includes the following steps: Laser cutting involves placing the bulging tube on a laser cutting fixture. The bulging tube includes a bulging processed tube and a connector (200) connected to the end of the processed tube. The laser cutting machine cuts at the connection point between the connector (200) and the processed tube to form the finished tube.

9. The thermal expansion process according to claim 8, characterized in that, The laser cutting fixture is provided with a mating surface that matches the flared opening (201) of the connector (200).

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