Crease-resistant inner supporting ejector rod device for thin-wall elbow pipe fitting

Abstract

The utility model provides a thin-wall elbow pipe fitting crease-resistant inner supporting ejector rod device which comprises an ejector rod, a push head is fixedly arranged at the front end of the ejector rod, an installation groove is formed in the ejector rod in the front-back direction and penetrates through the push head, and a spring is installed in the installation groove in the front-back direction. The inner supporting piece is connected with the ejector rod in a sliding mode in the front-back direction, and the front end of the spring abuts against the inner supporting piece and applies forward elastic force to the inner supporting piece; when the inner supporting piece is located at the limiting position of the front end of the ejector rod, the front end of the inner supporting piece is located on the front side of the front end of the push head. The device is used for assisting machining and forming of the thin-wall elbow. The common ejector rod directly pushes the metal pipe to move towards the core rod; the ejector rod can push the metal pipe to move towards the core rod through the push head, and meanwhile, the inner supporting piece extends into the metal pipe to support the pipe wall in the metal pipe, so that the metal pipe is prevented from wrinkling during bending.

Description

Technical Field

[0001] This utility model relates to the field of elbow pipe fitting processing technology, specifically to a wrinkle-resistant inner support rod device for thin-walled elbow pipe fittings. Background Technology

[0002] Mandrel bending technology is one of the mainstream processes for bending metal pipes. This technology uses a mandrel to support the inner wall of the pipe and, together with the guiding action of the bending die, achieves plastic deformation of the pipe, effectively improving the forming accuracy of pipes with conventional wall thickness.

[0003] On October 17, 2022, the applicant applied for a utility model patent with patent number CN202222719516.4, entitled "Demolding Device for a Mandrel-Type Metal Bending Tube Forming Machine".

[0004] The aforementioned patent discloses a mandrel-type tube bending forming device, and references... Figure 1 As shown.

[0005] It includes a pipe bending mold 1, a mandrel 2, and a push rod 3. The pipe bending mold 1 forms a pipe bending channel 4 that adapts to the contour of the pipe fitting. The mandrel 2 is fixedly set at one end of the pipe bending mold 1. The metal pipe 5 to be processed is placed in the pipe bending mold 1 and sleeved on the mandrel 2. The push rod 3 applies an axial thrust to the other end of the pipe bending mold 1, so that the metal pipe 5 moves along the pipe bending channel 4 and completes the bending and forming under the guidance of the mandrel 2.

[0006] The technology disclosed in the above patent can be used for bending medium and thick-walled metal pipes.

[0007] However, in the processing practice of 1-3mm thin-walled metal tubes, this technical solution has gradually revealed obvious limitations: due to the thin wall thickness of the thin-walled metal tube, its resistance to instability is much lower than that of conventional thick-walled tubes. During the process of push rod 3 pushing the tube to move towards mandrel 2, the mandrel first enters the front end of the tube, and the inner wall of the front end of the tube can be supported by the mandrel, so wrinkling will not occur; during the process of the mandrel entering the tube, there will be a section of the inner wall of the rear end of the tube that is not supported at all, and the tube wall is prone to wrinkling in this unsupported area. Utility Model Content

[0008] In view of the problems pointed out in the background art, this utility model proposes a wrinkle-resistant inner support rod device for thin-walled elbow pipe fittings to solve the above-mentioned technical problems.

[0009] The technical solution of this utility model is implemented as follows:

[0010] A wrinkle-resistant internal support rod device for thin-walled elbow pipe fittings includes a push rod, with a push head fixedly provided at the front end of the push rod.

[0011] The push rod has an installation groove inside along the front-to-back direction, the installation groove passes through the push head, and a spring is installed inside the installation groove along the front-to-back direction;

[0012] It also includes an inner support member that is slidably connected to the top rod in the front-back direction, and the front end of the spring abuts against the inner support member and applies a forward elastic force to the inner support member;

[0013] When the inner support is at its extreme position at the front end of the push rod, the front end of the inner support is located in front of the front end of the push head.

[0014] The present invention is further configured such that the pusher head is a semi-cylindrical structure, the pusher head and the push rod are coaxially arranged, and the outer diameter of the pusher head is larger than the outer diameter of the push rod.

[0015] The present invention is further configured such that the inner support member is a semi-cylindrical structure, the inner support member is coaxially arranged with the top rod, the plane containing the central axis of the inner support member is in contact with the plane containing the central axis of the push head and forms a sliding fit, and the rear end of the inner support member is provided with an annular sliding sleeve, which is slidably sleeved on the outer side wall of the top rod.

[0016] The present invention is further configured such that the inner support member is provided with a connecting groove extending through its rear end, and the front end of the spring extends into the connecting groove and abuts against the inner support member.

[0017] The present invention is further configured such that the outer diameter of the inner support member is equal to the outer diameter of the pusher.

[0018] The present invention is further configured such that the outer diameter of the sliding sleeve is equal to the outer diameter of the pusher.

[0019] The present invention is further configured such that the rear end of the top rod is provided with a rearwardly extending connecting post, the diameter of which is smaller than the outer diameter of the top rod.

[0020] By adopting the above technical solution, the beneficial effects of this utility model are as follows:

[0021] The anti-wrinkle inner support rod device for thin-walled elbow pipe fittings provided by this utility model is used to assist in the processing and forming of thin-walled elbows. Ordinary rods directly push the metal tube towards the mandrel; the rod of this application can push the metal tube towards the mandrel through a pusher, while the inner support extends into the metal tube to support the tube wall inside the metal tube, preventing wrinkling of the metal tube when bending.

[0022] Initially, the front end of the metal tube is aligned with the starting end of the mandrel, the front end of the pusher head abuts against the rear end of the metal tube, and the inner support extends into the metal tube, with its front end abutting against the mandrel. When the push rod drives the pusher head forward, the metal tube gradually moves towards the mandrel. At this time, the inner support remains abutting against the mandrel and slides backward relative to the push rod, compressing the spring until the front end of the pusher head is flush with the front end of the inner support. The metal tube is then completely pushed onto the mandrel, completing the bending process. The push rod then moves backward to return to its original position. During the return process, the compressed spring pushes the inner support forward.

[0023] During the molding process of the elbow, the inner arc area of ​​the elbow is prone to wrinkling, so the inner support component provides support and protection for the corresponding area. Attached Figure Description

[0024] To more clearly illustrate the technical solutions in the embodiments of this utility model 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 some embodiments of this utility model. For those skilled in the art, other drawings can be obtained based on these drawings without creative effort.

[0025] Figure 1 This is a schematic diagram of the existing technology.

[0026] Figure 2 This is a schematic diagram of the structure of the present invention. Figure 1 .

[0027] Figure 3 This is a schematic diagram of the structure of the present invention. Figure 2 .

[0028] Figure 4 This is a schematic diagram of the internal structure of this utility model.

[0029] Figure 5 This is a schematic diagram of the structure of this utility model in use.

[0030] The following are the labels in the attached diagram: Mold 1, Mandrel 2, Push Rod 3, Bend Channel 4, Metal Pipe 5, Ejector Rod 10, Push Head 20, Mounting Slot 30, Spring 40, Inner Support 50, Sliding Sleeve 60, Connecting Slot 70, Connecting Column 80. Detailed Implementation

[0031] The technical solutions of the present utility model will be clearly and completely described below with reference to the accompanying drawings of the embodiments. Obviously, the described embodiments are only some embodiments of the present utility model, and not all embodiments. Based on the embodiments of the present utility model, all other embodiments obtained by those of ordinary skill in the art without creative effort are within the protection scope of the present utility model.

[0032] For reference as follows Figures 1-5 The present invention will be described as follows:

[0033] Example: The anti-wrinkle internal support top rod device for thin-walled elbow pipe disclosed in this utility model uses a long cylindrical top rod 10 as the load-bearing and transmission component. By integrating functional components such as a pusher 20, an inner support 50, and a spring 40, it forms an integrated structure of "pushing-supporting-elastic compensation". Its innovation lies in upgrading the single pushing function of the traditional top rod to a composite function of "external pushing + internal real-time support". Through the coordinated action of the inner support 50 and the pusher 20, it achieves full-process support for the key areas of the inner wall of the thin-walled metal pipe 5, structurally solving the wrinkling problem during the bending process.

[0034] The anti-wrinkle internal support rod device for thin-walled elbow pipe fittings includes an elongated rod 10, which is cylindrical.

[0035] A push head 20 is fixedly provided at the front end of the push rod 10. The push head 20 has a semi-cylindrical structure and is coaxially arranged with the push rod 10. The outer diameter of the push head 20 is larger than the outer diameter of the push rod 10.

[0036] The push rod 10 has a mounting groove 30 machined inside along the front-to-back direction. The mounting groove 30 passes through the push head 20, and a spring 40 is installed inside the mounting groove 30 along the front-to-back direction. The mounting groove 30 is a blind hole structure, extending from the rear end of the push rod 10 and passing through the front end of the push head 20, forming a mounting and guiding channel for the spring 40. Its inner diameter precisely matches the outer diameter of the spring 40, ensuring that the spring 40 has no radial displacement during extension and retraction.

[0037] It also includes an inner support member 50 (the inner support member 50 is a component that realizes the anti-wrinkle function) that is slidably connected to the top rod 10 in the front-back direction, and the front end of the spring 40 abuts against the inner support member 50 and applies a forward elastic force to the inner support member 50.

[0038] When the inner support member 50 is at the extreme position of the front end of the push rod 10, the front end of the inner support member 50 is located in front of the front end of the push head 20.

[0039] The inner support member 50 is a semi-cylindrical structure. The outer diameter of the inner support member 50 is equal to the outer diameter of the push head 20. The inner support member 50 is coaxially arranged with the push rod 10. The plane containing the central axis of the inner support member 50 is in contact with the plane containing the central axis of the push head 20, forming a sliding fit. The plane side of the push head 20 is in contact with the plane side of the inner support member 50, forming a sliding fit surface. This provides circumferential restraint for the inner support member 50 (restricting the circumferential rotation of the inner support member 50 around the push rod 10, preventing the inner support member 50 from deflecting during sliding and causing support failure), and also ensures smooth sliding of the inner support member 50 in the front-back direction.

[0040] The rear end of the inner support member 50 is provided with an annular sliding sleeve 60. The inner diameter of the sliding sleeve 60 matches the outer diameter of the push rod 10, and the outer diameter of the sliding sleeve 60 is equal to the outer diameter of the push head 20. The sliding sleeve 60 is slidably fitted onto the outer side wall of the push rod 10. The inner support member 50 and the push rod 10 form a sliding fit in the front-rear direction through the sliding sleeve 60. When the inner support member 50 moves forward to the extreme position of the front end of the push rod 10, the sliding sleeve 60 abuts against the rear side of the push head 20.

[0041] The inner support member 50 is provided with a connecting groove 70 extending through its rear end to accommodate the front end of the spring 40. The front end of the spring 40 extends into the connecting groove 70 and abuts against the inner support member 50. This structural design allows the elastic force of the spring 40 to be evenly transmitted to the inner support member 50 through the bottom of the connecting groove 70.

[0042] Spring 40 is a cylindrical helical compression spring, which is installed in the mounting groove 30 of the top rod 10 in the front-back direction. Its front end extends into the connecting groove 70 of the inner support 50 and abuts against the side wall of the connecting groove, while its rear end abuts against the bottom of the mounting groove 30, forming a pre-compressed state.

[0043] The rear end of the push rod 10 is provided with a rearwardly extending connecting post 80. The diameter of the connecting post 80 is smaller than the outer diameter of the push rod 10, forming a stepped structure. The connecting post 80 is used to connect with the drive device that drives the push rod 10 to move back and forth.

[0044] Before bending, the thin-walled metal tube 5 (wall thickness 1-3mm) to be processed is placed in the bending channel 4 of the bending mold 1, ensuring that the front end of the metal tube 5 is precisely aligned with the starting end of the mandrel 2, so that the mandrel 2 can smoothly extend into the metal tube 5. Then, the drive device moves the push rod 10 forward, causing the front end of the push head 20 to abut against the rear end of the metal tube 5. Simultaneously, the inner support member 50 extends into the metal tube 5 under the elastic force of the spring 40, with its front end abutting against the rear end of the mandrel 2. At this point, the inner support member 50 is at the extreme position of the front end of the push rod 10, the sliding sleeve 60 abuts against the rear side of the push head 20, and the spring 40 remains in its initial pre-compression state. The inner support member 50 and the push head 20 together form a support structure for the rear end of the metal tube 5. The purpose of this stage is to establish a rigid support chain of "core rod - inner support member - top rod". The front end of the inner support member 50 is connected to the core rod 2, and the rear end is connected to the top rod through the spring 40, so that the inner wall of the metal tube 5 is supported from the position of the core rod 2 to the front end of the top rod, avoiding local depression caused by the lack of support of the tube wall during the initial push.

[0045] When the driving device applies axial thrust to drive the push rod 10 forward, the push head 20 acts directly on the rear end of the metal tube 5, pushing the metal tube 5 along the bent tube channel 4 towards the mandrel 2. The metal tube 5 begins to gradually fit onto the mandrel 2 and undergoes bending deformation. During this process, since the front end of the inner support 50 remains in abutting state with the mandrel 2, the inner support 50 slides backward relative to the push rod 10, and the spring 40 is further compressed, with its elastic force increasing as the amount of compression increases. The anti-wrinkle mechanism at this stage is reflected in the fact that the inner support 50 is always located inside the bending area of ​​the metal tube 5, and its semi-cylindrical structure forms continuous support for the inner arc area of ​​the inner wall of the metal tube 5, effectively resisting the compressive stress on the inner tube wall during bending and avoiding wrinkles caused by stress concentration.

[0046] As the push rod 10 continues to advance, the metal tube 5 gradually and completely fits onto the mandrel 2, its curved shape perfectly conforming to the bending channel 4 of the bending mold 1, completing the bending process. At this point, the front end of the pusher 20 is flush with the front end of the inner support 50, and the inner support 50 slides backward relative to the push rod 10 to its maximum stroke, compressing the spring 40 to its maximum compression. The entire device reaches the end position of its working stroke. The supporting effect of the inner support 50 continues until the metal tube 5 is fully formed, ensuring that its inner wall remains supported during the final stage of bending deformation, preventing wrinkles and springback caused by stress release at the end of the forming process.

[0047] After the elbow is formed, the drive device moves the push rod 10 back to its original position. During this process, the compressed spring 40 releases its elastic potential energy, pushing the inner support 50 to slide forward relative to the push rod 10 until the inner support 50 returns to the extreme position at the front end of the push rod 10. The sliding sleeve 60 then abuts against the rear side of the push head 20 again, and the device returns to its initial state, ready for the next pipe bending process.

[0048] To address the core issue of wrinkling in the inner arc area when the thin-walled metal tube 5 is bent, a structure is adopted in which a semi-cylindrical inner support 50 and a pusher 20 work together to precisely support the inner arc area of ​​the metal tube 5.

[0049] Through the elastic compensation mechanism of spring 40, the inner support 50 can adjust its support position in real time according to the pushing speed and bending deformation of metal tube 5.

[0050] The above description is only a preferred embodiment of the present utility model and is not intended to limit the present utility model. Any modifications, equivalent substitutions, improvements, etc., made within the spirit and principles of the present utility model should be included within the protection scope of the present utility model.

Claims

1. A wrinkle-preventing inner support and ejector rod device for thin-walled elbow pipe fittings, comprising an ejector rod, a push head being fixedly arranged at the front end of the ejector rod, characterized in that: an installation groove is arranged in the ejector rod in the front-rear direction, the installation groove penetrating the push head, a spring being arranged in the installation groove in the front-rear direction; an inner support member is further arranged in sliding connection with the ejector rod in the front-rear direction, the front end of the spring abutting against the inner support member and applying a forward spring force to the inner support member; when the inner support member is located at the limit position of the front end of the ejector rod, the front end of the inner support member is located in front of the front end of the push head. The push head is in a semi-cylindrical structure, the push head being coaxially arranged with the ejector rod, the outer diameter of the push head being greater than the outer diameter of the ejector rod. The inner support member is in a semi-cylindrical structure, the inner support member being coaxially arranged with the ejector rod, the plane in which the central axis of the inner support member is located being in abutting arrangement with the plane in which the central axis of the push head is located and forming a sliding fit, a circular ring-shaped sliding sleeve being arranged at the rear end of the inner support member, the sliding sleeve being slidingly sleeved on the outer sidewall of the ejector rod. A connecting groove penetrating the rear end of the inner support member is arranged on the inner support member, the front end of the spring being inserted into the connecting groove and abutting against the inner support member.

2. A wrinkle-preventing internal support ejector rod device for thin-walled elbow pipe according to claim 1, characterized in that: The outer diameter of the inner support member is equal to the outer diameter of the push head.

3. A wrinkle-free internal support ejector rod device for thin-wall elbow pipe fittings as defined in claim 2, wherein: The outer diameter of the sliding sleeve is equal to the outer diameter of the push head.

4. A wrinkle-preventing internal support ejector rod device for thin-walled elbow pipe according to claim 3, characterized in that: The rear end of the ejector rod is provided with a connecting column extending rearward, the diameter of the connecting column being smaller than the outer diameter of the ejector rod.

5. A wrinkle-free internal support ejector rod device for thin-wall elbow pipe fittings as defined in claim 3 wherein: ​ 6. A wrinkle-free internal support ejector rod device for thin-wall elbow pipe fittings as defined in claim 3 wherein: ​ 7. A wrinkle-free internal support push rod device for thin-wall elbow pipe fittings according to any one of claims 1-6, characterized in that: ​

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