Long-service-life core rod for pipe bending device

Abstract

The utility model provides a long-life core rod for a pipe bending device, which comprises a core rod, the core rod is a cylinder, the core rod is provided with a hollow cavity along the axis, the core rod comprises a pipe bending end and a connecting end, the pipe bending end is connected with a center penetrating ball, and the connecting end is connected with a pull rod of the pipe bending device. Oil grooves are formed in the inner side walls of the hollow cavities. According to the utility model, the metal pipe can be prevented from wrinkling and deforming due to instability in the pipe bending process, the pipe bending quality is improved, the abrasion of the center penetrating ball and the core rod is reduced, the service life is prolonged, the maintenance period is prolonged, and the production cost is reduced.

Description

Technical Field

[0001] This utility model belongs to the field of pipe bending equipment technology, specifically relating to a long-life mandrel for pipe bending devices. Background Technology

[0002] A pipe bending device is a metal forming equipment that bends metal pipes into specific shapes using a die. During the pipe bending process, the inner material of the metal pipe experiences compressive stress due to pressure, which can easily lead to instability and wrinkling. To achieve ideal pipe fittings, a mandrel is often used in conjunction with a through-hole column to prevent this defect. The mandrel contacts and supports the inner wall of the metal pipe, suppressing compressive instability and preventing wrinkling. Traditional mandrels are mostly made of copper or brass (such as H96 brass), which have good thermal conductivity, ductility, and processing performance. However, copper has relatively low hardness and is prone to wear during high-frequency bending or processing of hard pipes, resulting in a short mandrel lifespan and frequent replacement, increasing maintenance costs. Furthermore, after prolonged exposure to bending stress, copper mandrels are prone to plastic deformation, affecting bending accuracy.

[0003] Therefore, the above problems urgently need to be solved. Utility Model Content

[0004] Purpose of the utility model: In order to overcome the above shortcomings, this utility model provides a long-life mandrel for a pipe bending device, which can support the inner wall of the metal pipe, prevent the metal pipe from wrinkling and deforming due to instability during the bending process, improve the bending quality, reduce the wear of the mandrel and the core bead, increase the service life, extend the maintenance cycle, and reduce the production cost.

[0005] Technical Solution: To achieve the above objectives, this utility model provides a long-life mandrel for a pipe bending device, comprising a mandrel, which is cylindrical, with a hollow cavity along its axis. The mandrel includes a bending end and a connecting end. The bending end is connected to a through-bead, and the connecting end is connected to the pull rod of the pipe bending device. An oil groove is provided on the inner wall of the hollow cavity. This utility model is used for metal pipe bending, preventing wrinkles and deformation of the metal pipe due to instability during bending, thus improving the quality of the bent pipe. In this utility model, the bending end is connected to a through-bead, and the connecting end is connected to the pull rod of the pipe bending device. The metal pipe to be bent is placed on the mandrel, with the end of the metal pipe to be bent extending out of the mandrel. The clamping mechanism of the pipe bending device clamps the part of the metal pipe to be bent. Then, the clamping mechanism drives the metal pipe to rotate along the pipe bending mold. When the metal pipe reaches the bending angle, the mandrel is pulled out, the clamping mechanism is opened, and the pipe bending is completed. The bending device connected in this utility model has a hollow tie rod, and the tie rod and the oiler are connected by an oil pipe. The oiler pumps oil into the hollow cavity through the tie rod. The lubricating grease enters the hollow cavity and flows from the oil groove into the gap between the mandrel and the bending end, covering the mandrel, lubricating the mandrel and the bending end, reducing friction between the metal pipe and the mandrel and the bending end, reducing wear, improving the service life of the mandrel, extending the mandrel maintenance cycle, and reducing production costs.

[0006] Furthermore, in the aforementioned long-life mandrel for the pipe bending device, an oil outlet hole is provided on the side wall of the bent pipe end, and the oil outlet hole communicates with the hollow cavity. By providing the oil outlet hole at the bent pipe end, an oiling machine injects grease into the hollow cavity, and the grease overflows from the oiling hole, lubricating the side wall of the mandrel, reducing friction between the mandrel and the metal pipe, reducing mandrel wear, and extending service life.

[0007] Furthermore, in the aforementioned long-life mandrel for pipe bending devices, two or more oil outlet holes are provided along the mandrel axis. Providing multiple oil outlet holes increases the lubricating oil injection volume, increases the oil film distribution area, and enhances the lubrication effect.

[0008] Furthermore, in the aforementioned long-life mandrel for pipe bending devices, the bending end is provided with a threaded cavity, a countersunk cavity, and a groove. These three components are integrally formed sequentially from the connecting end to the bending end. The inner wall of the threaded cavity has internal threads, and the inner diameter of the countersunk cavity is larger than that of the threaded cavity. A groove and a through-bead are correspondingly provided, with the through-bead connected within the groove. An oil groove extends from the threaded cavity to the groove. After the through-bead is connected to the threaded cavity, it forms an oil injection channel along the oil groove. Grease flows through this channel, through the countersunk cavity, into the groove, and finally to the outer surface of the through-bead, providing lubrication to the contact area between the through-bead and the metal pipe, thus reducing wear on the through-bead.

[0009] Furthermore, in the aforementioned long-life mandrel for pipe bending devices, the inner wall of the connecting end is provided with an internal thread, and the connecting end is threadedly connected to the pull rod of the pipe bending device. The mandrel is threadedly connected to the pull rod through the connecting end, ensuring connection stability and tightness, and improving maintenance convenience.

[0010] Furthermore, in the aforementioned long-life mandrel for the pipe bending device, a locking platform is provided on the outer wall of the mandrel, symmetrically arranged on both sides of the mandrel's axial section. The axial section is a plane passing through the mandrel's axis. When the mandrel is threaded to the pull rod of the pipe bending device, a wrench is used to clamp the locking platform to ensure that the preload of the mandrel and pull rod connection reaches the design value, ensuring a tight connection.

[0011] Furthermore, in the aforementioned long-life mandrel for pipe bending devices, oil grooves are arranged in an array along the mandrel axis, and the cross-section of the oil grooves is semi-circular. The semi-circular oil grooves reduce the resistance to grease flow, and the multiple oil grooves arranged in an array form multiple oil injection channels, improving oil injection efficiency and ensuring lubrication effect.

[0012] Furthermore, in the aforementioned long-life mandrel for the pipe bending device, the mandrel material is preferably high-carbon, high-chromium alloy tool steel. Both the mandrel and the through-bead are preferably made of high-carbon, high-chromium alloy tool steel, processed using a cryogenic process, and possess advantages such as high hardness and good wear resistance.

[0013] As can be seen from the above technical solution, this utility model has the following beneficial effects: The long-life mandrel of this utility model for pipe bending devices, used in metal pipe bending processing, can prevent wrinkles and deformation of metal pipes due to instability during the bending process, thus improving the quality of pipe bending. By setting oil grooves and oil outlet holes, the mandrel and the through-bead are lubricated, reducing wear on the through-bead and the mandrel, increasing their service life to 14,000 pieces, extending the maintenance cycle, and reducing production costs. Attached Figure Description

[0014] Figure 1 This is a front view of the long-life mandrel used in the pipe bending device of this utility model;

[0015] Figure 2 for Figure 1 The sectional view shown is along line AA.

[0016] Figure 3 for Figure 2 The left view shown.

[0017] In the diagram: 1. Mandrel, 11. Hollow cavity, 12. Bend end, 121. Oil groove, 122. Oil outlet, 123. Threaded cavity, 124. Countersunk cavity, 125. Groove, 13. Connecting end, 14. Locking platform. Detailed Implementation

[0018] Example 1

[0019] like Figure 1The diagram illustrates a long-life mandrel for a pipe bending device, comprising a mandrel 1, which is cylindrical. The mandrel 1 has a hollow chamber 11 along its axis. The mandrel 1 includes a bending end 12 and a connecting end 13. The bending end 12 is connected to a through-bead, and the connecting end 13 is connected to the pull rod of the pipe bending device. An oil groove 121 is provided on the inner wall of the hollow chamber 11. The pull rod of the pipe bending device is a hollow pull rod, and the pull rod is connected to an oil pump via an oil pipe.

[0020] In this embodiment, the side wall of the bent pipe end 12 is provided with an oil outlet hole 122, which is connected to the hollow cavity 11.

[0021] In this embodiment, there are two or more oil outlet holes 122 along the axis of the mandrel 1.

[0022] Figure 2 The long-life mandrel shown in the diagram for a pipe bending device has a threaded cavity 123, a countersunk cavity 124, and a groove 125 at the bending end 12. These three components are integrally formed sequentially from the connecting end 13 to the bending end 12. The inner wall of the threaded cavity 123 has internal threads, and the inner diameter of the countersunk cavity 124 is larger than that of the threaded cavity 123. A corresponding mandrel is provided in the groove 125, connected to the mandrel within it. An oil groove 121 extends from the threaded cavity 123 to the groove 125. After the mandrel is connected to the threaded cavity 123, it forms an oil injection channel along the oil groove 121. Grease enters the groove 125 through the countersunk cavity 124 via this channel and finally flows to the outer surface of the mandrel, providing lubrication to the contact area between the mandrel and the metal pipe, thus reducing wear on the mandrel.

[0023] In this embodiment, the inner wall of the connecting end 13 is provided with an internal thread, and the connecting end 13 is threadedly connected to the pull rod of the pipe bending device. The mandrel 1 is threadedly connected to the pull rod through the connecting end 13, ensuring connection stability and tightness, and improving maintenance convenience.

[0024] In this embodiment, a locking platform 14 is provided on the outer wall of the mandrel 1, and the locking platform 14 is symmetrically arranged on both sides of the axial section of the mandrel 1. The axial section is set as a plane passing through the axis of the mandrel 1. When the mandrel 1 is connected to the pull rod of the bending device by a thread, a wrench is used to clamp the locking platform 14 to ensure that the preload of the connection between the mandrel 1 and the pull rod reaches the design value and to ensure the connection is tight.

[0025] Figure 3 The long-life mandrel shown in the pipe bending device has oil grooves 121 arranged in an array along the axis of the mandrel 1, and the cross-section of the oil grooves 121 is semi-circular. The semi-circular oil grooves 121 reduce the resistance to grease flow, and the multiple oil grooves 121 arranged in an array form multiple oil injection channels, improving oil injection efficiency and ensuring lubrication effect.

[0026] In this embodiment, the mandrel 1 is preferably made of high-carbon, high-chromium alloy tool steel. Both the mandrel 1 and the through-bead are preferably made of high-carbon, high-chromium alloy tool steel, and a cryogenic process is used to improve their hardness and wear resistance.

[0027] In this invention, the bent end 12 of the mandrel 1 is connected to the through-bead, and the connecting end 13 is threadedly connected to the pull rod of the bending device. The metal tube to be bent is placed on the mandrel 1, with the end of the metal tube to be bent extending out of the mandrel 1. The clamping mechanism of the bending device clamps the part of the metal tube to be bent. The oiling machine is started, and oil is pumped into the hollow chamber 11 through the pull rod. The lubricating grease enters the hollow chamber 11 and flows from the oil groove 121 into the gap between the through-bead and the bent end 12, thus covering the surface of the through-bead. Simultaneously, grease overflows from the oiling hole 122, lubricating the side wall of the mandrel 1. Then, the clamping mechanism drives the metal tube to rotate along the bending mold. When the metal tube reaches the bending angle, the mandrel 1 is pulled out, the clamping mechanism is opened, and the bending is completed.

[0028] The above embodiments are exemplary and are intended to illustrate the technical concept and features of this utility model, so that those skilled in the art can understand the content of this utility model and implement it accordingly. They should not be construed as limiting the scope of protection of this utility model. All equivalent changes or modifications made in accordance with the spirit and essence of this utility model should be covered within the scope of protection of this utility model.

Claims

1. A long-life mandrel for a pipe bending device, characterized in that: Includes a core rod (1), the core rod (1) is cylindrical, the core rod (1) has a hollow cavity (11) along the axis, the core rod (1) includes a bent end (12) and a connecting end (13), the bent end (12) is connected to the through bead, and the connecting end (13) is connected to the pull rod of the bent tube device; the inner wall of the hollow cavity (11) is provided with an oil groove (121).

2. The long-life mandrel for a pipe bending device according to claim 1, characterized in that: The side wall of the bent end (12) is provided with an oil outlet (122), which is connected to the hollow cavity (11).

3. The long-life mandrel for a pipe bending device according to claim 2, characterized in that: There are two or more oil outlet holes (122) along the axis of the mandrel (1).

4. The long-life mandrel for a pipe bending device according to claim 1, characterized in that: The bent end (12) is provided with a threaded cavity (123), a countersunk cavity (124) and a groove (125). The threaded cavity (123), the countersunk cavity (124) and the groove (125) are integrally arranged from the connecting end (13) to the bent end (12). The inner wall of the threaded cavity (123) is provided with an internal thread. The inner diameter of the countersunk cavity (124) is larger than the inner diameter of the threaded cavity (123). The groove (125) and the through-bead are provided accordingly. The through-bead is connected in the groove (125). The oil groove (121) extends from the threaded cavity (123) to the groove (125).

5. The long-life mandrel for a pipe bending device according to claim 1, characterized in that: The inner wall of the connecting end (13) is provided with an internal thread, and the connecting end (13) is threadedly connected to the pull rod of the bending device.

6. The long-life mandrel for a pipe bending device according to claim 1, characterized in that: The outer wall of the mandrel (1) is provided with a locking platform (14), which is symmetrically arranged on both sides of the axial section of the mandrel (1).

7. The long-life mandrel for a pipe bending device according to claim 1, characterized in that: The oil groove (121) is arranged in an array along the axis of the mandrel (1), and the cross-section of the oil groove (121) is semi-circular.

8. The long-life mandrel for a pipe bending device according to claim 1, characterized in that: The mandrel (1) is made of high-carbon, high-chromium alloy tool steel.

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