Small R-shaped bent pipe die

Abstract

The utility model discloses a small R pipe bending die which comprises a die body rotatably installed on a machine frame, the die body is connected with an adjustable clamping mechanism, and the clamping mechanism can clamp pipe fittings with different pipe diameters so that the pipe fittings can be bent conveniently. The clamping mechanism comprises an upper clamping plate and a lower clamping plate, the left end of the upper clamping plate and the left end of the lower clamping plate are connected to the upper end face and the lower end face of the die body respectively, a cavity is formed between the upper clamping plate and the lower clamping plate, and an inner clamping block and an outer clamping block are detachably embedded in the cavity. A locking adjusting structure is installed between the right end of the upper clamping plate and the right end of the lower clamping plate, the upper clamping plate and the lower clamping plate are locked through the locking adjusting structure, and the inner clamping block and the outer clamping block are clamped. The upper clamping plate and the lower clamping plate are matched up and down and used for fixing the inner clamping block and the outer clamping block, the clamping device is integrally formed to clamp the pipe fitting to be bent, and the pipe fitting bending device has the technical advantages of being simple in structure, adaptive to pipe fittings of different sizes, high in flexibility, suitable for application and popularization and the like.

Description

Technical Field

[0001] This utility model relates to a pipe bending mold, and more specifically, to a small R pipe bending mold, belonging to the field of pipe bending molds. Background Technology

[0002] With the continuous development of the boiler manufacturing industry, not only water-cooled wall components and superheater components, but also tubes with diameters of φ51 and above have begun to be used. Due to the limitations of boiler structure, the bending radius is designed to be relatively small, usually R / D < 1.4, the straight section L < 100mm and there are various straight sections, and the quality requirements for elbows are getting higher and higher.

[0003] Existing conventional pipe bending machines lack top supports and side thrusters. To ensure bending quality, an R / D ratio ≥ 1.5 is typically required. Furthermore, the limitations of the machine's chassis pose significant challenges to die design for small-radius bends. The technical drawbacks of conventional dies—requiring an R / D ≥ 1.5, a straight section length L ≥ 100mm, and a large die size—cannot guarantee the quality of small-radius bends, leading to substandard roundness at the bend. Therefore, more advanced equipment is necessary, but limited resources introduce numerous uncertainties to production and significantly increase costs. Utility Model Content

[0004] To address the aforementioned technical problems, this utility model provides a small R-bending pipe mold with technical characteristics such as simple structure, adaptability to pipe fittings of different sizes, high flexibility, and suitability for widespread use.

[0005] To achieve the above objectives, this utility model is implemented through the following technical solution:

[0006] This utility model discloses a small R-shaped pipe bending mold, comprising a rotatable mold body mounted on a frame. An adjustable clamping mechanism is connected to the mold body, capable of clamping pipes of different diameters to facilitate pipe bending. The clamping mechanism includes an upper clamping plate and a lower clamping plate. The left ends of the upper and lower clamping plates are respectively connected to the upper and lower end faces of the mold body, forming a cavity between them. An inner clamping block and an outer clamping block are detachably embedded within the cavity. A locking adjustment structure is installed between the right ends of the upper and lower clamping plates, locking the upper and lower clamping plates and clamping the inner and outer clamping blocks. The upper and lower clamping plates cooperate to fix the inner and outer clamping blocks, forming a clamping device that holds the pipe to be bent.

[0007] Preferably, the locking adjustment structure includes an eccentric shaft with pins formed at both ends. Corresponding pin holes are provided on the right ends of the upper and lower clamping plates. The eccentric shaft is rotatably mounted by the pins at both ends passing through the pin holes in the upper and lower clamping plates, respectively. A locking element 7 is connected to the pin at the upper end of the eccentric shaft. The locking element 7 is located on the outer surface of the upper clamping plate, and it drives the eccentric shaft to rotate and lock it in place. The eccentric shaft passes through the pin holes of the upper and lower clamping blocks, and by rotating, pushes the outer clamping block 4 forward, clamping the pipe to be bent.

[0008] Preferably, the mold body is fixedly mounted on the frame of the pipe bending machine via a mold body base.

[0009] Preferably, a semi-circular opening is provided on the right end face of the inner clamping block, and a semi-circular opening is provided on the left end face of the outer clamping block. The semi-circular openings of the inner clamping block and the outer clamping block form an accommodating space for the pipe to be bent.

[0010] Preferably, the inner clamping block and the outer clamping block each include several, and the diameter of the semi-circular opening on different inner clamping blocks and different outer clamping blocks is different to adapt to different pipe fittings.

[0011] Preferably, the locking element is an end cap for manual turning.

[0012] Preferably, the locking component is an end cap, and the end cap includes an independent upper part and a lower part. The upper part is fixedly connected to the upper end of the pin, and the lower part is threaded on the pin. Turning the upper part by hand drives the eccentric shaft to rotate and clamp the pipe to be bent. Rotating the lower part fits against the outer surface of the upper clamping plate and locks the eccentric shaft.

[0013] Beneficial effects: Simple structure, strong practicality, applicable to bending small-radius pipes with ordinary pipe bending machines, improving resource utilization, greatly reducing bending costs, and ensuring product quality; high flexibility, good structural stability, suitable for widespread use. Attached Figure Description

[0014] Figure 1 This is a schematic diagram of the overall structure of this utility model.

[0015] Figure 2 This is a cross-sectional view of section AA of this utility model.

[0016] Figure 3 This is a schematic diagram of the structure of the base of the mold of this utility model.

[0017] Figure 4 This is a side view of the base of the model.

[0018] Figure 5 This is a schematic diagram of the structure of the inner clamping block and the outer clamping block of this utility model. Detailed Implementation

[0019] 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.

[0020] In the description of the utility model, it should be noted that the terms "upper", "lower", "inner", "outer", "left", "right", etc., indicate the orientation or positional relationship based on the orientation or positional relationship shown in the accompanying drawings. They are only for the convenience of describing the utility model and simplifying the description, and do not indicate or imply that the device referred to must have a specific orientation, or be constructed and operated in a specific orientation. Therefore, they should not be construed as limitations on the utility model.

[0021] In the description of this utility model, it should be noted that, unless otherwise explicitly specified and limited, the terms "installation," "setting," "connection," etc., should be interpreted broadly. For example, "connection" can be a fixed connection, a detachable connection, or an integral connection; it can be a mechanical connection or an indirect connection through an intermediate medium. Those skilled in the art can understand the specific meaning of the above terms in this utility model based on the specific circumstances.

[0022] Because R / D < 1.4, the ovality of pipes bent by ordinary pipe bending machines usually exceeds the standard. The standard acceptable value is generally < 12%. According to NB / T47032 Technical Conditions for Small Radius Pipe Bending for Waste Heat Boilers, the groove shape of the pipe bending machine mold is usually the outer diameter of the outer tube. Reverse deformation is performed on the outer clamping block groove using an industry-experienced reverse deformation formula. However, bending in this way will result in an ovality exceeding the standard range by 1%-2%. Therefore, special treatment is applied to the bottom of the inner clamping block groove. A 20mm milling cutter is used to mill a depth of 1mm into the arc-shaped bottom, and the transition part is manually ground. With this treatment, the ovality meets the requirements.

[0023] Typically, the straight section of a pipe bending die is integral with the die body, and the straight section has a fixed size. However, due to issues such as the design of the drawings, when the straight section has multiple sizes, and the size is smaller than the fixed size, the straight section is usually cut while clamping the die body, which is irreversible for the die body. This invention uses an embedded inner clamping block, which can be easily disassembled without damaging the die body. For small straight sections, to ensure no interference during bending, the inner and outer clamping blocks are specially designed to provide space for the bent pipe fitting elbow while ensuring that the outer clamping block does not fall off during bending.

[0024] When bending pipes, the lateral thrust of the pipe bending machine is relatively large. Ordinary pipe bending machines do not have a tie rod device for the mold body. Due to the small size of the mold body, the stability is insufficient. Therefore, the mold body will tilt to a certain extent during bending. To address this problem, the technical solution of this application adopts the addition of a mold body base, which is equivalent to adding a large support to the bottom of the mold body. The base and the mold body are separate structures, which are convenient to manufacture and can reduce the mold manufacturing cost.

[0025] The mold assembly of a conventional pipe bending machine typically consists of three parts: the bending die body, the outer clamping block, and the clamping plate. Due to the large bending radius, the die body can directly mate with the keyways and positioning holes on the pipe bending machine base. Furthermore, even with a large die body, the straight section of the bent pipe on the die body can still meet the required dimensions, making the design relatively simple. However, in production, when encountering small-radius pipe bends, if a conventional pipe bending machine cannot bend the pipe or guarantee the quality, more advanced equipment, such as a pipe bending machine with a rear support, is usually sought. This is problematic because equipment resources are limited, resulting in high operating costs, and even using a pipe bending machine with a rear support does not guarantee the quality of small-radius bends. Therefore, this invention aims to improve the mold assembly using existing conditions of conventional pipe bending machines to meet the needs of actual production.

[0026] The technology / principle of this utility model:

[0027] 1) It overcomes the problem of the mold size required to match the base of the pipe bending machine by cleverly dividing the mold into two parts and adding a mold base. The base and the mold are welded together to form a whole. This overcomes the problem that small molds cannot match the base and also increases the problem of mold tilting caused by the lack of tie rods in ordinary pipe bending machines during bending.

[0028] 2) By adopting a clever design, the structure of the mold body is improved, which makes it easier to solve the problem of excessive ellipticity when bending small-radius pipes with ordinary pipe bending machines.

[0029] 3) To address the issue of small straight sections in the drawings, the structure of the mold was altered. A flexible inner clamping block was used in conjunction with the outer clamping block to create different straight section size sequences, effectively solving the problem of small straight sections in the bending process.

[0030] like Figure 1-5The illustration shows a specific embodiment of a small R-shaped pipe bending mold. This embodiment includes a mold body 1 rotatably mounted on a frame (the mold body 1 rotates on the frame via a motor-driven rotating shaft; due to the rotation of the mold body 1, the clamped pipe fitting 8 can be bent at a set speed under a certain pressure). An adjustable clamping mechanism is connected to the mold body 1, which can clamp pipe fittings 8 of different diameters to facilitate bending the pipe fitting 8. The clamping mechanism includes an upper clamping plate 5 and a lower clamping plate 6. The left ends of the upper clamping plate 5 and the lower clamping plate 6 are respectively connected to the upper and lower end faces of the mold body 1, and a cavity is formed between the upper clamping plate 5 and the lower clamping plate 6. An inner clamping block 3 and an outer clamping block 4 are detachably embedded in the cavity. A locking adjustment structure is installed between the right end of the upper clamping plate 5 and the right end of the lower clamping plate 6. The locking adjustment structure locks the upper clamping plate 5 and the lower clamping plate 6 and clamps the inner clamping block 3 and the outer clamping block 4. The upper clamping plate 5 and the lower clamping plate 6 cooperate to fix the inner and outer clamping blocks, forming a clamping device to clamp the pipe to be bent 8.

[0031] Working principle of the pipe bending die: During pipe bending, the pipe fitting 8 is placed between the inner clamping block 3 and the outer clamping block 4. The pipe fitting is pressed against the inner clamping block 3 of the pipe bending die. A suitable outer clamping block 4 is then assembled (both the inner clamping block 3 and the outer clamping block 4 can be selected according to actual needs). The eccentric shaft is inserted into the through hole (pin hole) of the upper and lower clamping plates. The eccentric shaft is rotated to clamp and fix the pipe bending workpiece. The side-push mechanism of the pipe bending machine is driven to feed (it should be noted that the side-push mechanism of the pipe bending machine is a power mechanism and is not a necessary technical feature of this application. A power mechanism capable of bending pipe fittings can be selected according to actual needs. Specifically, it can be based on the program set on the side-push mechanism of the pipe bending machine, such as the rotation speed and angle of the die body 1). Through the pipe bending rotation shaft of the pipe bending machine (i.e., the entire die body 1 rotates), the pipe fitting is driven to rotate along the pipe bending die. Under a certain pressure, the pipe fitting completes the bending action at the set speed.

[0032] In a preferred embodiment, the locking adjustment structure includes an eccentric shaft with pins formed at both ends. Corresponding pin holes are provided on the right ends of the upper clamping plate 5 and the lower clamping plate 6. The eccentric shaft is rotatably inserted into the pin holes of the upper and lower clamping plates 5 and 6 respectively via the pins at both ends. A locking element 7 is connected to the upper pin of the eccentric shaft, located on the outer surface of the upper clamping plate 5. The locking element 7 drives the eccentric shaft to rotate and achieves locking. The eccentric shaft passes through the pin holes of the upper and lower clamping blocks. By rotating, it pushes the outer clamping block 4 forward, clamping the pipe piece 8 to be bent. The clamping function is achieved by varying degrees to which the eccentric shaft presses against the outer clamping block 4 at different angles.

[0033] In a preferred embodiment, the mold body 1 is fixedly mounted on the frame of the pipe bending machine via a mold body base 2. The mold body base 2 solves the problem that the small-R pipe bending mold cannot directly mate with the pipe bending machine base; it also solves the problem that ordinary pipe bending machines, without supporting the mold body, cause the mold body to tilt and become unstable due to the lateral force of the bending machine during bending, thus affecting the bending quality. After the mold body base and mold body are properly adjusted, they can be welded together to form a single unit. This facilitates the processing of the mold body and reduces its manufacturing cost.

[0034] In a preferred embodiment, a semi-circular opening is formed on the right end face of the inner clamping block 3, and a semi-circular opening is formed on the left end face of the outer clamping block 4. The semi-circular openings of the inner clamping block 3 and the outer clamping block form a space for accommodating the pipe to be bent 8. Ordinary pipe bending machines are suitable for bending pipes with an R / D ≥ 1.5. The groove shape of the mold body is generally designed to be the same as the pipe diameter. Sometimes, appropriate reverse deformation design can be performed according to conventional empirical formulas as needed. This application improves the pipe bending groove shape (i.e., the diameter of the semi-circular openings on different inner clamping blocks 3 and different outer clamping blocks 4) to ensure that the ellipticity of the bend meets the requirements when using this mold. Specifically, to solve the problem of small straight sections with various sizes in pipe bending, the straight section of the mold body is designed as a groove, combined with a detachable inner clamping block. The inner and outer clamping blocks can be designed with different size sequences according to the straight section of the pipe. They can be flexibly disassembled to adapt to the actual bending needs. The inner clamping block and the outer clamping block cooperate to form a through hole with the same outer diameter as the pipe. At the same time, in order to prevent the outer clamping block from loosening and falling off when the straight section of the bent pipe L=0, the outer clamping block has been improved and designed with an anti-fall-off structure. See the locking adjustment structure for details.

[0035] Furthermore, due to the small size of the mold body, the conventional bolt-fixed upper and lower clamping plates cannot be used properly. Therefore, the upper and lower clamping plates are improved. Considering the stress on the pipe during bending, the upper and lower clamping plates are designed to fit into the mold body's slots, and after adjustment and proper welding, they are used. By rotating the eccentric shaft, the eccentric shaft presses against the outer clamping block, clamping the pipe fitting. Driven by the pipe bending machine's drive unit, the clamping device rotates the pipe fitting, completing the pipe bending process.

[0036] In a preferred embodiment, the inner clamping block 3 and the outer clamping block 4 each comprise several units, and the diameters of the semi-circular openings on different inner clamping blocks 3 and different outer clamping blocks 4 are different to accommodate different pipe fittings 8. Specifically, the inner clamping blocks 3 and outer clamping blocks 4 are designed in various forms according to the straight section of the bent pipe drawing, i.e., they have semi-circular openings of different sizes. The inner and outer clamping blocks can be designed in different size sequences according to the straight section of the bent pipe. They can be flexibly disassembled to adapt to the actual bending needs. Figure 5A limiting component can be connected between the inner clamping block 3 and the outer clamping block 4 to prevent them from falling off. The limiting component is installed between the upper clamping plate 5 and the lower clamping plate 6. A reserved space is provided on the left side of the inner clamping block 3, formed by the protrusion at the upper left end of the inner clamping block 3. When the inner clamping block 3 and the outer clamping block 4 are released, the inner clamping block 3 can swing to a certain extent, allowing it to handle situations where the bend direction may be upward, downward, or other directions. This avoids the bend direction being restricted by the fixed groove shape (semi-circular opening) of the inner clamping block 3, allowing the bend (especially when multiple bends, multiple directions, and multiple angles) to turn freely.

[0037] In a preferred embodiment, the locking member 7 is an end cap for manual turning, which has a simple structure and strong practicality.

[0038] In a preferred embodiment, the locking component 7 is an end cap, which includes an independent upper part and a lower part. The upper part is fixedly connected to the upper end of the pin, and the lower part is threaded on the pin. Turning the upper part by hand drives the eccentric shaft to rotate and clamp the pipe to be bent 8. Rotating the lower part fits against the outer surface of the upper clamping plate 5 and locks the eccentric shaft. The structure is simple and practical.

[0039] Finally, it should be noted that this utility model is not limited to the above embodiments, and many variations are possible. All variations that can be directly derived or conceived by those skilled in the art from the disclosure of this utility model should be considered within the protection scope of this utility model.

Claims

1. A small R-bending pipe mold, characterized in that: The device includes a rotatable mold body (1) mounted on a frame. An adjustable clamping mechanism is connected to the mold body (1). The clamping mechanism can clamp pipe fittings (8) of different diameters to facilitate bending of the pipe fittings (8). The clamping mechanism includes an upper clamping plate (5) and a lower clamping plate (6). The left end of the upper clamping plate (5) and the left end of the lower clamping plate (6) are respectively connected to the upper end face and the lower end face of the mold body (1). A cavity is formed between the upper clamping plate (5) and the lower clamping plate (6). An inner clamping block (3) and an outer clamping block (4) are detachably embedded in the cavity. A locking adjustment structure is installed between the right end of the upper clamping plate (5) and the right end of the lower clamping plate (6). The locking adjustment structure locks the upper clamping plate (5) and the lower clamping plate (6) and clamps the inner clamping block (3) and the outer clamping block (4).

2. The small R-bending pipe mold according to claim 1, characterized in that: The locking adjustment structure includes an eccentric shaft, with pins formed at both ends of the eccentric shaft. Corresponding pin holes are provided on the right end of the upper clamping plate (5) and the right end of the lower clamping plate (6). The eccentric shaft is inserted into the pin holes of the upper clamping plate (5) and the lower clamping plate (6) respectively through the pins at both ends to achieve rotational setting. A locking member (7) is connected to the pin at the upper end of the eccentric shaft. The locking member (7) is located on the outer surface of the upper clamping plate (5). The eccentric shaft is rotated and locked by the locking member (7).

3. A small R-bending pipe mold according to claim 1 or 2, characterized in that: The mold (1) is fixedly installed on the frame of the pipe bending machine via the mold (1) base.

4. A small R-bending pipe mold according to claim 1, characterized in that: A semi-circular opening is provided on the right end face of the inner clamping block (3), and a semi-circular opening is provided on the left end face of the outer clamping block (4). The semi-circular opening of the inner clamping block (3) and the semi-circular opening on the outer clamping block form a space for accommodating the pipe to be bent (8).

5. A small R-bending pipe mold according to claim 4, characterized in that: The inner clamping block (3) and the outer clamping block (4) each include several, and the diameter of the semi-circular opening on different inner clamping blocks (3) and different outer clamping blocks (4) is different to adapt to different pipe fittings (8).

6. A small R-bending pipe mold according to claim 2, characterized in that: The locking element (7) is an end cap for manual turning.

7. A small R-bending pipe mold according to claim 2, characterized in that: The locking component (7) is an end cap, and the end cap includes an independent upper part and a lower part. The upper part is fixedly connected to the upper end of the pin shaft, and the lower part is threaded on the pin shaft. The upper part is turned by hand to drive the eccentric shaft to rotate and clamp the pipe to be bent (8). The lower part is rotated to fit against the outer surface of the upper clamping plate (5) to lock the eccentric shaft.

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