Variable-diameter bending die for parallel pipe bender and its bending and forming method

Abstract

The present invention relates to a variable-diameter bending die for a parallel pipe bender and a bending forming method thereof, which includes a moving platform, a hydraulic cylinder, a transmission unit, a substrate, a limit unit holder and a limit unit. The transmission unit and the limit unit are circumferentially arranged inside the substrate. The middle and lower connecting rod of the transmission unit is connected to the substrate, the lower connecting rod is rotatably connected to the upper connecting rod, the limit unit is rotatably connected to the upper connecting rod, and the limit unit is rotatably connected to the limit unit holder. The limit unit holder is connected to the moving platform. Both ends of the hydraulic cylinder are rigidly connected to the substrate and the moving platform respectively, and the hydraulic rod is located on one side of the substrate. The present invention designs a variable-diameter bending die by adopting the principle of a double-slider mechanism, and realizes the unfolding or folding of the bending die through the telescopic movement of the hydraulic cylinder, so that the bending die can adapt to pipes with different diameters and improve the processing efficiency.

Description

Technical Field

[0001] The present invention belongs to the technical field of pipe bending forming, and particularly relates to a variable-diameter bending die for a parallel pipe bender and a bending forming method thereof. Background Art

[0002] The parallel pipe bender is a new type of pipe bending forming device that has emerged in recent years, and the bending die is an important component in the parallel pipe bender. The bending die is fixed to the moving platform by bolts, and the pipe passes through the round hole in the middle of the bending die. The bending forming of the pipe is achieved through the rotation of the moving platform and the limit of the bending die. Different bending dies can be replaced according to different pipe diameters.

[0003] At present, there are still some deficiencies in the pipe bending forming of the parallel pipe bender bending die. The main problem is that the bending die has a fixed pipe diameter, and different bending dies need to be replaced according to different processing objects. The replacement of the bending die requires manual disassembly, the process is complex, there are safety hazards, there are certain requirements for installation, and the manufacturing of the bending die is relatively difficult and needs to be stored separately.

[0004] In view of the above problems, the present invention proposes a variable-diameter bending die for a parallel pipe bender. This device can automatically change the diameter of the bending die, eliminating the need for additional manufacturing and installation processes, improving the adaptability of the bending die to pipes of different diameters, and improving the processing efficiency. Summary of the Invention

[0005] Aiming at the problems existing in the prior art, the present invention provides a variable-diameter bending die for a parallel pipe bender and a bending forming method thereof. Using the principle of a double-slider mechanism, a variable-diameter bending die composed of a base plate, a transmission unit, a limit unit, a limit unit cage, a hydraulic cylinder, and a moving platform is designed. The expansion or contraction of the bending die is realized by driving and controlling the forward and backward movement of the base plate by the hydraulic cylinder. At the same time, the self-locking function of the hydraulic cylinder can be used to lock the diameter of the bending die, enabling the bending die to flexibly adapt to pipes of different diameters, thereby improving the processing efficiency and reducing the manufacturing cost.

[0006] The technical solution adopted by the present invention is a variable-diameter bending die for a parallel pipe bender, which includes a moving platform, a hydraulic cylinder, a transmission unit, a base plate, a limit unit holder and a limit unit. The base plate is arranged above the moving platform. Both the moving platform and the base plate are in a circular ring structure, and circular holes through which pipes can pass are provided at the middle of both the moving platform and the base plate. The limit unit holder is arranged between the moving platform and the base plate, and the limit unit holder includes holding columns and a holding ring. The holding columns are evenly distributed on the holding ring around the center of the holding ring. The first end of each holding column is fixedly connected to the moving platform, and the second end of each holding column is fixedly connected to the holding ring. The plurality of limit units are evenly distributed around the limit unit holder. Each limit unit is located between two adjacent holding columns, and the lower end of the bottom end face of each limit unit is rotatably connected to the holding ring through a rotating pair. The transmission units are evenly distributed on the base plate around the central axis of the base plate. Each transmission unit includes a lower connecting rod and an upper connecting rod. The first end of the lower connecting rod is fixedly connected to the base plate, and the second end of the lower connecting rod is rotatably connected to the first end of the upper connecting rod through a first rotating pair. The second end of the upper connecting rod is rotatably connected to the upper end of the bottom of the limit unit through a second rotating pair. The hydraulic cylinder is arranged between the base plate and the moving platform. The fixed end of the hydraulic cylinder is fixedly connected to the moving platform, and the driving end of the hydraulic cylinder is fixedly connected to the base plate. Driving the hydraulic cylinder to extend and retract can drive the limit unit to rotate around the holding ring. Through the expansion and contraction of the limit unit, the change of the diameter of the bending die is realized to adapt to pipes with different diameters.

[0007] Further, when the left side surface of the limit unit is parallel to the central axis of the base plate, the bending die is in an expanded state; when the top end surface of the limit unit is parallel to the central axis of the base plate, the bending die is in a contracted state.

[0008] Preferably, the limit unit is a plane symmetric structure and a wedge structure. The cross-section of the limit unit is a rectangular cross-section. The rectangular cross-section of the limit unit forms a tapered structure along the height direction of the limit unit. The length of the long side of the bottom end face of the limit unit is equal to 5 times the length of the short side, and the length of the long side of the top end face of the limit unit is equal to 5 times the length of the short side.

[0009] Preferably, the central axis of the moving platform coincides with the central axis of the base plate, and the center of the holding ring is on the central axis of the moving platform.

[0010] Preferably, the axis of the first rotating pair is parallel to the axis of the second rotating pair, and the second rotating pair is parallel to the short side edge of the bottom end face of the limit unit.

[0011] Preferably, a bearing is also disposed at the first end of the upper connecting rod in the transmission unit, and the first end of the upper connecting rod is rotatably connected to the second end of the lower connecting rod by a bolt.

[0012] In a second aspect of the present invention, there is provided a method for a variable-diameter bending die for a parallel pipe bender, which comprises the following steps:

[0013] S1. Install the moving platform in the bending die on the pipe bender;

[0014] S2. Drive the hydraulic cylinder to extend to drive the substrate to move, and then gradually unfold the limiting unit. When the diameter of the bending die is adjusted to adapt to the diameter value of the pipe, the hydraulic cylinder stops operating;

[0015] S3. Pass the pipe through the round hole in the middle of the substrate, the retaining frame of the limiting unit, and the round hole in the middle of the moving platform;

[0016] S4. Drive the hydraulic cylinder to retract to drive the substrate to move, and then gradually contract the limiting unit, so that the top end surface of each limiting unit contacts the outer wall of the pipe, completing the fixed limit of the pipe;

[0017] S5. Start the pipe bender to realize the bending and forming of the pipe.

[0018] The features and beneficial effects of the present invention are as follows:

[0019] 1. A variable-diameter bending die for a parallel pipe bender and its bending and forming method provided by the present invention adopt the principle of a double-slider mechanism to design a variable-diameter bending die composed of a substrate, a transmission unit, a limiting unit, a retaining frame of the limiting unit, a hydraulic cylinder, and a moving platform. The expansion or contraction of the bending die is realized by driving and controlling the forward and backward movement of the substrate by the hydraulic cylinder. At the same time, the self-locking function of the hydraulic cylinder can be used to lock the diameter of the bending die, so that the bending die can flexibly adapt to pipes of different diameters, thereby improving the processing efficiency.

[0020] 2. A variable-diameter bending die for a parallel pipe bender and its bending and forming method provided by the present invention use a hydraulic cylinder as a driving element, which has a large driving force and a self-locking function. The diameter of the bending die can be locked without other devices, and has the advantages of simple structure and easy implementation.

[0021] 3. A variable-diameter bending die for a parallel pipe bender and its bending forming method provided by the present invention. The diameter of the bending die can be freely changed, eliminating the need to manufacture bending dies of different diameters, which is convenient and fast, and compensates for the defect that traditional bending dies need to be manually replaced. During the processing of the pipe bender, the diameter of the bending die can be freely changed, which is beneficial to continuously process pipes of different diameters and provides more possibilities for processing pipes with variable diameters. BRIEF DESCRIPTION OF THE DRAWINGS

[0022] Figure 1 is a schematic diagram of the overall structure of the variable-diameter bending die of the present invention;

[0023] Figure 2 is a schematic diagram of the connection of the drive unit, limit unit, limit unit cage and substrate of the present invention;

[0024] Figure 3 is a schematic diagram of the unfolded state of the bending die of the present invention;

[0025] Figure 4 is a schematic diagram of the contracted state of the bending die of the present invention;

[0026] Figure 5 is a schematic diagram of the intermediate unfolded state of the bending die of the present invention;

[0027] Figure 6 is a schematic diagram of the limit unit of the present invention;

[0028] Figure 7 is a flowchart of the bending forming method of the present invention.

[0029] MAIN REFERENCE MARKS:

[0030] Moving platform 1; Hydraulic cylinder 2; Drive unit 3; Lower connecting rod 31; Upper connecting rod 32; Substrate 4; Limit unit cage 5; Holding column 51; Holding ring 52; Limit unit 6. DETAILED DESCRIPTION OF THE EMBODIMENTS

[0031] To elaborate on the technical content, structural features, achieved objectives and effects of the present invention in detail, the following will be described in detail with reference to the accompanying drawings of the specification.

[0032] The present invention provides a variable-diameter bending die for a parallel pipe bender, as Figures 1 to 5As shown in the figure, it includes a moving platform 1, a hydraulic cylinder 2, a transmission unit 3, a base plate 4, a limit unit holder 5 and a limit unit 6. The base plate 4 is arranged above the moving platform 1. Both the moving platform 1 and the base plate 4 are in a ring structure shape, and circular holes through which the pipe can pass are provided in the middle of both the moving platform 1 and the base plate 4. The limit unit holder 5 is arranged between the moving platform 1 and the base plate 4. The limit unit holder 5 includes holding columns 51 and a holding ring 52. The holding columns 51 are evenly distributed on the holding ring 52 around the center of the holding ring 52. The first end of the holding column 51 is fixedly connected to the moving platform 1, and the second end of the holding column 51 is fixedly connected to the holding ring 52. A plurality of limit units 6 are evenly distributed around the limit unit holder 5. Each limit unit 6 is located between two adjacent holding columns 51. The lower end of the bottom end face of each limit unit 6 is rotationally connected to the holding ring 52 through a rotating pair. The transmission units 3 are evenly distributed on the base plate 4 around the central axis of the base plate 4. Each transmission unit 3 includes a lower connecting rod 31 and an upper connecting rod 32. The first end of the lower connecting rod 31 is fixedly connected to the base plate 4, and the second end of the lower connecting rod 31 is rotationally connected to the first end of the upper connecting rod 32 through a first rotating pair. The second end of the upper connecting rod 32 is rotationally connected to the upper end of the bottom of the limit unit 6 through a second rotating pair. The hydraulic cylinder 2 is arranged between the base plate 4 and the moving platform 1. The fixed end of the hydraulic cylinder 2 is fixedly connected to the moving platform 1, and the driving end of the hydraulic cylinder 2 is fixedly connected to the base plate 4. Driving the hydraulic cylinder 2 to extend and retract can drive the limit unit 6 to rotate around the holding ring 52. Through the expansion and contraction of the limit unit 6, it is used to realize the change of the diameter of the bending die to adapt to pipes of different diameters. When the left side surface of the limit unit 6 is parallel to the central axis of the base plate 4, the bending die is in an expanded state; when the top end face of the limit unit 6 is parallel to the central axis of the base plate 4, the bending die is in a contracted state.

[0033] As Figure 6 shown, the limit unit 6 is a plane symmetric structure and a wedge structure. The cross-section of the limit unit 6 is a rectangular cross-section. The rectangular cross-section of the limit unit 6 forms a tapered structure along the height direction of the limit unit 6. The length of the long side a61 of the bottom end face of the limit unit 6 is equal to 5 times the length of the short side a62. The length of the long side a63 of the top end face of the limit unit 6 is equal to 5 times the length of the short side a64, that is, a61 = 5a62, a63 = 5a64.

[0034] In a preferred manner, the central axis of the moving platform 1 coincides with the central axis of the base plate 4, and the center of the holding ring 52 is on the central axis of the moving platform 1. The axis of the first rotating pair is parallel to the axis of the second rotating pair, and the second rotating pair is parallel to the short side edge of the bottom end face of the limit unit 6.

[0035] In a preferred embodiment, a bearing is further disposed at the first end of the upper connecting rod 32 in the transmission unit, and the first end of the upper connecting rod 32 is rotatably connected to the second end of the lower connecting rod 31 by a bolt.

[0036] On the other hand, as Figure 7 shown, a bending and forming method for a variable-diameter bending die of a parallel pipe bender is provided, which includes the following steps:

[0037] S1. Install the moving platform 1 in the bending die on the pipe bender;

[0038] S2. Drive the hydraulic cylinder 2 to extend to drive the substrate 4 to move, and then gradually expand the limiting unit 6. When the diameter of the bending die is adjusted to adapt to the diameter value of the pipe, the hydraulic cylinder 2 stops operating;

[0039] S3. Pass the pipe through the round hole in the middle of the substrate 4, the limiting unit holder 5, and the round hole in the middle of the moving platform 1;

[0040] S4. Drive the hydraulic cylinder 2 to retract to drive the substrate 4 to move, and then gradually contract the limiting unit 6, so that the top end face of each limiting unit 6 contacts the outer wall of the pipe, completing the fixed limit of the pipe;

[0041] S5. Start the pipe bender to realize the bending and forming of the pipe.

[0042] The specific operation steps of the present invention are as follows:

[0043] The present invention provides a variable-diameter bending die for a parallel pipe bender and its bending and forming method. As Figures 1 to 6 shown, it includes a moving platform 1, a hydraulic cylinder 2, a transmission unit 3, a substrate 4, a limiting unit holder 5, and a limiting unit 6. The limiting unit holder 5 is disposed between the moving platform 1 and the substrate 4. A plurality of limiting units 6 are evenly distributed around the limiting unit holder 5, and the lower end of the bottom end face of each limiting unit 6 is rotatably connected to the holding ring 52 in the limiting unit holder 5 through a rotating pair. The transmission unit 3 is evenly distributed on the substrate 4 around the central axis of the substrate 4, and each transmission unit 3 includes a lower connecting rod 31 and an upper connecting rod 32. The first end of the lower connecting rod 31 is fixedly connected to the substrate 4, and the second end of the lower connecting rod 31 is rotatably connected to the first end of the upper connecting rod 32 through a first rotating pair. The second end of the upper connecting rod 32 is rotatably connected to the upper end of the bottom of the limiting unit 6 through a second rotating pair. The hydraulic cylinder 2 is disposed between the substrate 4 and the moving platform 1. Driving the hydraulic cylinder 2 to expand and contract can drive the limiting unit 6 to rotate around the holding ring 52. Through the expansion and contraction of the limiting unit 6, the diameter of the bending die can be changed to adapt to pipes with different diameters.

[0044] In the specific working process, the limit unit cage 5 is rigidly connected to the moving platform 1. The limit unit cage 5 can ensure the relative position between the moving platform 1 and the rotating shaft of the limit unit 6 remains unchanged. By driving the telescopic movement of the hydraulic cylinder 2, the substrate 4 is controlled to move forward or backward. The substrate 4 drives the transmission unit 3 to realize the contraction and expansion of the bending die, and further realizes the limitation of pipes with different diameters. At the same time, the bending die is of a symmetrical structure with good stress, and the transmission unit is mainly a two-force member with a simple stress form, which can reduce the requirements for materials and machining accuracy.

[0045] The present invention designs the limit unit and its transmission device based on the principle of a double-slider mechanism, with flexible movement mode and large movement range. It can change the diameter of the bending die during the bending process to achieve continuous processing of pipes with different diameters, providing more possibilities for processing pipes with variable diameters. At the same time, a hydraulic cylinder is used as the driving element, which has a large driving force and a self-locking function, and can lock the diameter of the bending die without other devices, with the advantages of simple structure and easy implementation. In addition, topological optimization is carried out on the limit unit and the transmission unit according to the actual working conditions, so that the main stress members have better stress performance, meet the strength requirements and stiffness requirements during the bending process, and ensure the yield rate of the processed products.

[0046] The embodiments described above are only used to describe the preferred embodiments of the present invention, and do not limit the scope of the present invention. Without departing from the design spirit of the present invention, various deformations and improvements made by those of ordinary skill in the art to the technical solutions of the present invention shall fall within the protection scope determined by the claims of the present invention.

Claims

1. A variable-diameter bending die for a parallel pipe bender, characterized in that, it includes a moving platform, a hydraulic cylinder, a transmission unit, a base plate, a limit unit holder and a limit unit, the base plate is arranged above the moving platform, both the moving platform and the base plate are in a circular ring structure, and circular holes through which pipes can pass are provided in the middle of both the moving platform and the base plate; the limit unit holder is arranged between the moving platform and the base plate, and the limit unit holder includes holding columns and a holding ring. The holding columns are evenly distributed on the holding ring around the center of the holding ring. The first end of the holding column is fixedly connected to the moving platform, and the second end of the holding column is fixedly connected to the holding ring. A plurality of the limit units are evenly distributed and surrounded on the limit unit holder. Each limit unit is located between two adjacent holding columns, and the lower end of the bottom end face of each limit unit is rotatably connected to the holding ring through a rotating pair. The transmission units are evenly distributed on the base plate around the central axis of the base plate, and each transmission unit includes a lower connecting rod and an upper connecting rod. The first end of the lower connecting rod is fixedly connected to the base plate, and the second end of the lower connecting rod is rotatably connected to the first end of the upper connecting rod through a first rotating pair. The second end of the upper connecting rod is rotatably connected to the upper end of the bottom of the limit unit through a second rotating pair; the hydraulic cylinder is arranged between the base plate and the moving platform, and the fixed end of the hydraulic cylinder is fixedly connected to the moving platform, and the driving end of the hydraulic cylinder is fixedly connected to the base plate. Driving the hydraulic cylinder to extend and retract can drive the limit unit to rotate around the holding ring. Through the expansion and contraction of the limit unit, it is used to realize the change of the diameter of the bending die to adapt to pipes of different diameters.

2. The variable-diameter bending die for a parallel pipe bender according to claim 1, characterized in that, when the left side surface of the limit unit is parallel to the central axis of the base plate, the bending die is in an expanded state; when the top end surface of the limit unit is parallel to the central axis of the base plate, the bending die is in a contracted state.

3. The variable-diameter bending die for a parallel pipe bender according to claim 1, characterized in that, the limit unit is a plane-symmetric structure and a wedge structure. The cross-section of the limit unit is a rectangular cross-section. The rectangular cross-section of the limit unit forms a tapered structure along the height direction of the limit unit. The length of the long side of the bottom end face of the limit unit is equal to 5 times the length of the short side, and the length of the long side of the top end face of the limit unit is equal to 5 times the length of the short side.

4. The variable-diameter bending die for a parallel pipe bender according to claim 1, characterized in that, the central axis of the moving platform coincides with the central axis of the base plate, and the center of the holding ring is on the central axis of the moving platform.

5. The variable-diameter bending die for a parallel pipe bender according to claim 1, characterized in that, The axis of the first rotating pair is parallel to the axis of the second rotating pair, and the second rotating pair is parallel to the short side edge of the bottom end face of the limiting unit.

6. The variable-diameter bending die for a parallel pipe bender according to claim 1, characterized in that a bearing is further arranged at the first end of the upper connecting rod in the transmission unit, and the first end of the upper connecting rod is rotatably connected to the second end of the lower connecting rod through a bolt.

7. A bending forming method for a variable-diameter bending die for a parallel pipe bender according to any one of claims 1 to 6, characterized in that it includes the following steps: S1. Install the moving platform in the bending die on the pipe bender; S2. Drive the hydraulic cylinder to extend to drive the substrate to move, and then gradually unfold the limiting unit. When the diameter of the bending die is adjusted to adapt to the diameter value of the pipe, the hydraulic cylinder stops operating; S3. Pass the pipe through the round hole in the middle of the substrate, the retaining frame of the limiting unit, and the round hole in the middle of the moving platform; S4. Drive the hydraulic cylinder to retract to drive the substrate to move, and then gradually contract the limiting unit, so that the top end face of each limiting unit contacts the outer wall of the pipe, and the fixing and limiting of the pipe are completed; S5. Start the pipe bender to realize the bending and forming of the pipe.

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