Sealing head for high-pressure sealing of hydraulic forming die

Abstract

The sealing head comprises a sealing head body, a liquid injection hole is formed in the sealing head body, the sealing head body comprises an insertion section, a sealing section and an external section, the insertion section is used for being inserted into the pipe end of a part, the sealing section is used for connecting the insertion section with the external section, and the sealing section is used for sealing the external section. The sealing section is arranged in a circular frustum shape, the diameter of the sealing section is gradually reduced in the liquid flowing direction, and when the inserting section is inserted into the part pipe end, the sealing section enters the part pipe end and extrudes the inner wall of the part pipe end to form sealing. A multi-conical-surface sealing structure is adopted, surface contact of steps is avoided through line contact, and a conical included angle has a certain centering function, so that the pressure is uniform, the axial self-tightening force is small when a sealing head retreats after the process is completed, and the service life is greatly prolonged.

Description

Technical Field

[0001] The present invention relates to the technical field of hydroforming, and particularly relates to a sealing head for high-pressure sealing of a hydroforming die. Background Art

[0002] In a hydroforming die, the upper mold cavity and the lower mold cavity are closed, and at the same time, the horizontal cylinders at both ends of the die push the sealing head to contact the end of the part tube for sealing. During the sealing process, high-pressure liquid is injected into the through hole of the sealing head so that the part is expanded into the shape of the mold cavity; during this process, the pressure of the internal high-pressure liquid needs to reach about 130 Mpa. Due to the reaction force, the overall force on the sealing head is relatively large, and it is extremely easy to damage and crack, and the sealing is not tight and the pressure is released, resulting in the interruption of the process and the scrapping of the parts.

[0003] In the past, the commonly used hydraulic sealing head was a stepped seal. The plane or stepped surface was easy to machine and convenient to adjust. However, the internal pressure of this process was relatively large, the plane contact area was wide, and it was extremely easy to loosen and break under high pressure. The bolts needed to be tightened regularly, and the sealing step surface was easy to crack. Summary of the Invention

[0004] In view of this, the purpose of the present invention is to provide a sealing head for high-pressure sealing of a hydroforming die, which adopts a multi-conical surface sealing structure and avoids the surface contact of the steps through line contact.

[0005] The sealing head for high-pressure sealing of a hydroforming die provided by the present invention adopts the following technical solutions:

[0006] A sealing head for high-pressure sealing of a hydroforming die includes a sealing head body. A liquid injection hole is provided in the sealing head body. The sealing head body includes an insertion section, a sealing section, and an external section. The insertion section is used to be inserted into the end of the part tube. The sealing section is used to connect the insertion section and the external section. The sealing section is arranged as a circular truncated cone, and the diameter of the sealing section gradually decreases along the liquid flow direction. When the insertion section is inserted into the end of the part tube, the sealing section enters the end of the part tube and extrudes the inner wall of the part tube to form a seal.

[0007] Further, the included angle between the outer wall of the sealing section and the central axis of the sealing head body is 18°-22°.

[0008] Further, a blocking step for blocking the end of the part tube is formed at the connection between the external section and the sealing section.

[0009] Further, a fillet is provided at the connection between the sealing section and the blocking step.

[0010] Further, a fillet is provided at the connection between the blocking step and the external section.

[0011] Further, it further includes a connecting section for connecting the insertion section and the sealing section, the diameter of the connecting section being greater than the maximum diameter of the insertion section and less than the minimum diameter of the sealing section.

[0012] Further, the connections of the connecting section with the insertion section and the sealing section are both provided with rounded corners.

[0013] Further, a plurality of steps are provided on the inner wall of the liquid injection hole, and the inner diameter of the liquid injection hole increases from small to large along the liquid flow direction.

[0014] Further, a plurality of fixing holes for fixing itself are evenly provided around the liquid injection hole in the sealing head body.

[0015] Further, the edge of the end face of the insertion section is provided with a rounded corner.

[0016] In summary, the present invention includes at least one of the following beneficial effects: adopting a multi-conical surface sealing structure, which avoids the surface contact of the steps through line contact, and the conical angle has a certain centering function, so that the pressure is evenly distributed. When the sealing head is withdrawn during the process completion, the axial self-tightening force is small, so the service life is greatly improved. Description of the Drawings

[0017] Figure 1 is a schematic diagram of an embodiment of the present invention;

[0018] Figure 2 is a side cross-sectional view of an embodiment of the present invention.

[0019] Description of the Reference Numerals:

[0020] 1. Insertion section; 2. Sealing section; 3. External section; 4. Liquid injection hole; 5. Plugging step; 6. Connecting section; 7. Fixing hole. Detailed Embodiments

[0021] The following uses specific specific examples to illustrate the implementation manners of the present invention. Those skilled in the art can easily understand 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 implementation manners, and 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.

[0022] The following combines the attached Figure 1-2 to further elaborate on the present invention in detail.

[0023] An embodiment of the present invention discloses a sealing head for high-pressure sealing of a hydroforming die. Refer to Figure 1-2, The sealing head for high-pressure sealing of a hydroforming die includes a sealing head body. A liquid injection hole 4 is provided inside the sealing head body. The sealing head body includes an insertion section 1, a sealing section 2, and an external section 3. The insertion section 1 is used to be inserted into the end of a part tube. The sealing section 2 is used to connect the insertion section 1 and the external section 2. The sealing section 2 is arranged in a circular frustum shape, and the diameter of the sealing section 3 gradually decreases along the liquid flow direction. When the insertion section 1 is inserted into the end of the part tube, the sealing section 2 enters the end of the part tube and extrudes the inner wall of the part tube to form a seal. The diameter of the insertion section 1 gradually decreases along the liquid flow direction to ensure that the insertion section 1 can be tightly inserted into the end of the part tube.

[0024] The circular frustum design of the sealing section 2 can optimize the sealing effect by adjusting the angle of the frustum and the diameter change rate. The design of the external section 3 can consider the connection method with other parts of the die to ensure the stability of the sealing head body in a high-pressure environment.

[0025] The position and size of the liquid injection hole 4 can be optimized according to the flow rate and pressure of the hydraulic liquid to ensure that the liquid can be evenly injected into the end of the part tube. The material selection of the sealing head body can consider the strength and corrosion resistance in a high-pressure environment to improve the service life of the sealing head.

[0026] Through the coordinated action of the insertion section 1, the sealing section 2, and the external section 3, effective sealing of the end of the part tube can be achieved in a high-pressure environment. The circular frustum design of the sealing section 1 can, when the insertion section is inserted into the end of the part tube, extrude the inner wall of the part tube through the gradually decreasing diameter, thereby forming a reliable seal, having better sealing performance and stability, and being able to effectively avoid problems such as poor sealing and pressure relief, improving the success rate of the hydroforming process and the quality of the parts.

[0027] In this embodiment, the angle between the outer wall of the sealing section 2 and the central axis of the sealing head body is 18° - 22°. The design of this angle enables the sealing section 2 to better contact the inner wall of the tube end when inserted into the end of the part tube, forming a uniform sealing pressure, thereby enhancing the sealing effect. The selection of the angle considers the stress situation of the sealing section 2 under the action of high-pressure liquid, avoiding problems such as sealing failure or local stress concentration caused by too large or too small an angle. As a preferred implementation, the angle between the outer wall of the sealing section 2 and the central axis can be set to 20° to achieve a balance between the sealing effect and the structural strength. By optimizing the angle between the outer wall of the sealing section and the central axis, the problems that the sealing head is prone to loosening, breaking, or poor sealing in a high-pressure environment are effectively solved. Compared with the traditional step seal, this design can better adapt to a high-pressure environment, reduce the risk of sealing head damage, and improve the reliability of the seal.

[0028] In this embodiment, a sealing step 5 for plugging the end of the part pipe is formed at the connection between the external section 3 and the sealing section 2. The provision of the sealing step 5 enables the sealing head body to effectively plug the pipe end when inserted into the part pipe end, preventing liquid leakage. The sealing step 5 not only improves the structural strength of the sealing head body 1 but also enhances its contact area with the part pipe end, thereby maintaining a stable sealing effect under the action of high-pressure liquid. Compared with planar or stepped surface sealing, the design of the sealing step 5 reduces stress concentration on the sealing surface, reduces the risk of the sealing head body cracking under high pressure, extends the service life of the sealing head body, and reduces the possibility of process interruption and part scrapping.

[0029] In this embodiment, the connection between the sealing section 2 and the sealing step 5 is provided with rounded corners, which can effectively reduce stress concentration, prevent material fatigue or fracture caused by stress concentration in a high-pressure environment, thereby improving the service life and reliability of the sealing head body, significantly enhancing the stability and durability of the sealing head body in a high-pressure environment, and avoiding process interruption and part scrapping problems caused by damage to the sealing head body.

[0030] In this embodiment, the connection between the sealing step 5 and the external section 3 is provided with rounded corners to reduce stress concentration and improve structural strength, effectively reducing stress concentration at the connection between the sealing step and the external section, and avoiding cracking and damage caused by the reaction force of high-pressure liquid.

[0031] In this embodiment, it further includes a connecting section 6 for connecting the insertion section 1 and the sealing section 2. The diameter of the connecting section 6 is larger than the maximum diameter of the insertion section 1 and smaller than the minimum diameter of the sealing section 2. The design of the connecting section 6 is to provide a transition structure, making the connection between the insertion section 1 and the sealing section 2 smoother and reducing stress concentration. The diameter of the connecting section 6 is selected to be larger than the maximum diameter of the insertion section 1 but smaller than the minimum diameter of the sealing section 2, which can ensure that the connecting section 6 plays a good transition role between the insertion section 1 and the sealing section 2, avoiding stress concentration problems caused by sudden diameter changes. Specifically, the connecting section 6 can adopt a cylindrical or conical structure, and its length can be adjusted according to actual needs to ensure connection stability and sealing effect.

[0032] In this embodiment, the connections between the connecting section 6 and the insertion section 1 and the sealing section 2 are both provided with rounded corners to ensure uniform stress distribution at the connections, avoid stress concentration, and improve the overall strength and durability of the sealing head body.

[0033] In this embodiment, multiple steps are provided on the inner wall of the liquid injection hole 4, and the inner diameter of the liquid injection hole 4 increases from small to large along the liquid flow direction. The design of multiple steps can effectively disperse the pressure generated during liquid flow, reduce local stress concentration, thereby reducing the risk of wear and rupture on the inner wall of the liquid injection hole 4. In addition, since the inner diameter of the liquid injection hole 4 increases from small to large along the liquid flow direction, the liquid flow rate can be gradually reduced, and the impact force of the liquid on the inner wall of the liquid injection hole 4 can be reduced, further improving the service life and sealing effect of the sealing head body. The steps on the inner wall of the liquid injection hole 4 can be designed to be evenly distributed, and the height and width of each step can be adjusted according to the actual liquid pressure and flow rate to ensure the best liquid flow effect and pressure dispersion effect. At the same time, the change in the inner diameter of the liquid injection hole 4 can adopt a linear or non-linear design, specifically depending on the liquid flow characteristics and the structural requirements of the sealing head body; effectively solving the problems of impact and wear on the inner wall of the sealing head body during the high-pressure liquid flow process, improving the durability and sealing performance of the sealing head body, thereby ensuring the stability and reliability of the hydroforming process.

[0034] In this embodiment, a plurality of fixing holes 7 for fixing itself are evenly provided around the liquid injection hole 4 in the sealing head body. The fixing holes 7 can be realized in various ways, such as using threaded holes, pin holes or snap structures, etc., to ensure that the sealing head body can be stably fixed in a high-pressure environment and avoid damage or sealing failure caused by uneven force. The fixing holes 7 are evenly distributed around the liquid injection hole 4 to balance the force distribution of the sealing head body under the action of high-pressure liquid, thereby improving the overall strength and stability of the sealing head body, and effectively solving the problems of damage or sealing failure of the sealing head body caused by excessive force in a high-pressure environment.

[0035] In this embodiment, the edge of the end face of the insertion section 1 is provided with a chamfer. By chamfering the edge of the end face of the insertion section 1, the stress concentration phenomenon during the insertion of the part pipe end can be effectively reduced, thereby reducing the risk of damage to the sealing head in a high-pressure environment. The setting of the chamfer can also improve the contact quality between the sealing head body and the part pipe end, further enhancing the sealing effect. At the same time, the chamfered edge of the insertion section 1 can also play a guiding role when the insertion section 1 is inserted into the part pipe end.

[0036] Finally, it should be noted that the above embodiments are only used to illustrate the technical solutions of the present invention and not to limit them. Although the present invention has been described in detail with reference to the preferred embodiments, those of ordinary skill in the art should understand that the technical solutions of the present invention can be modified or equivalently replaced without departing from the purpose and scope of the technical solutions of the present invention, and they should all be covered within the scope of the claims of the present invention.

Claims

1. A sealing head for high pressure sealing of a hydraulic forming die, characterized in that: The invention comprises a sealing head body, wherein a liquid injection hole (4) is arranged in the sealing head body, and the sealing head body comprises an insertion section (1), a sealing section (2) and an external section (3). The insertion section (1) is used to be inserted into a part pipe end, and the sealing section (2) is used to connect the insertion section (1) and the external section (2). The sealing section (2) is arranged in a circular frustum, and the diameter of the sealing section (3) gradually decreases along the liquid flow direction. When the insertion section (1) is inserted into the part pipe end, the sealing section (2) enters the part pipe end and squeezes the inner wall of the part pipe end to form a seal.

2. The sealing head for high pressure sealing of a hydraulic forming die according to claim 1, characterized in that: The angle between the outer wall of the sealing section (2) and the central axis of the sealing head body is 18°-22°.

3. The sealing head for high pressure sealing of a hydraulic forming die according to claim 1, characterized in that: A sealing step (5) for sealing the end of a component pipe is formed at the connection between the external section (3) and the sealing section (2).

4. The sealing head for high pressure sealing of a hydraulic forming die according to claim 3, characterized in that: The connection between the sealing section (2) and the blocking step (5) is rounded.

5. The sealing head for high pressure sealing of a hydraulic forming die according to claim 3, characterized in that: The connection between the blocking step (5) and the external section (3) is rounded.

6. The sealing head for high pressure sealing of a hydraulic forming die according to claim 1, characterized in that: It also comprises a connecting section (6) for connecting the insertion section (1) and the sealing section (2), wherein the diameter of the connecting section (6) is larger than the maximum diameter of the insertion section (1) and smaller than the minimum diameter of the sealing section (2).

7. The sealing head for high pressure sealing of a hydraulic forming die according to claim 6, characterized in that: The connection portions between the connection section (6) and the insertion section (1) and the sealing section (2) are all rounded.

8. The sealing head for high pressure sealing of a hydraulic forming die according to claim 1, characterized in that: The inner wall of the liquid injection hole (4) is provided with a plurality of steps, and the inner diameter of the liquid injection hole (4) increases from small to large along the liquid flow direction.

9. The sealing head for high pressure sealing of a hydraulic forming die according to claim 1, characterized in that: A plurality of fixing holes (7) for fixing the sealing head are evenly arranged around the liquid injection hole (4) in the sealing head body.

10. The sealing head for high pressure sealing of a hydraulic forming die according to claim 1, characterized in that: The end surface edge of the insertion section (1) is rounded.

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