Core rod for pipe bending machine and pipe bending machine

Abstract

The invention relates to the technical field of pipe bending machining, in particular to a mandrel for a pipe bending machine and the pipe bending machine, the upper end of a movable part on the mandrel is thicker, and the thickness of the movable part becomes thinner from top to bottom. Therefore, the gap between the lower ends of the adjacent movable parts is larger, and the gap between the upper ends is smaller. In the bending process, the enough bending angle can be guaranteed, and it can be guaranteed that the enough supporting area is provided. The movable part is composed of four supporting plates capable of stretching out and drawing back, and stretching out and drawing back of the four supporting plates are driven through hydraulic pressure. During normal use, the four supporting plates expand outwards to support the inner wall of the square pipe by injecting sufficient hydraulic media. And when the bending direction of the square tube is changed, the hydraulic medium can be drawn away to contract the four supporting plates, so that the size of the whole movable part is reduced, and the movable part can rotate in the square tube to adjust the angle. It is ensured that when the square tube is bent, the thicker expansion plate at the upper end is certainly matched with the stretching side wall of the square tube, and the thinner contraction plate at the lower end is matched with the compression side wall of the square tube.

Description

TECHNICAL FIELD

[0001] The present application relates to the technical field of pipe bending machine, and particularly relates to a mandrel for a pipe bending machine and the pipe bending machine. BACKGROUND

[0002] When the pipe bending operation is performed, since the pipe is a hollow structure, if the bending section lacks inner wall support, the cross section of the pipe material may be elliptical or collapsed after being extruded, especially when the pipe is thin-walled or small-radius bending; in addition, the bending inner side forms dense wrinkles due to material shrinkage, and the wrinkles may extend to the non-bending area when severe, and there are also adverse effects such as uncontrolled springback and precision deviation. The use of a mandrel for inner support can effectively improve the above-mentioned conditions. The existing mandrel for a square pipe bending machine, as shown in the prior art, is composed of a connecting rod and a plurality of movable support parts of the same size, and the movable support parts are hinged to each other, so that the whole can be bent to a certain degree of curvature, thereby providing support during pipe bending. Therefore, a certain gap is required between each movable part of the mandrel for the pipe bending machine, so that each movable part can be adjusted independently. Figure 1 When bending, the inner side of the movable part shrinks and eventually abuts against each other, so the overall bending angle of the mandrel is limited by the gap on the inner side of the movable part. The problem is that since the thickness of each movable part in the conventional mandrel for the pipe bending machine is uniform, in order to obtain a larger bending angle, the gap between each movable part needs to be set larger, but the gap after the expansion of the outer side of the movable part will become larger, thus reducing the support area and weakening the support effect.

[0003]

[0004] To this end, the movable part can be designed to have a thick outer side and a thin inner side, so that during bending, sufficient bending angle can be ensured, and the outer side can provide sufficient support. However, this design also has a problem, that is, the mandrel for a square pipe cannot rotate freely in the square pipe, unlike the mandrel for a round pipe. Therefore, when the square pipe needs to be bent multiple times and the bending directions are different, the thicker surface of the movable part will be located on the inner side of the contraction position, and the thinner surface will be located on the outer side of the stretching position, which cannot meet the normal bending support requirements. SUMMARY

[0005] Therefore, the present application aims to provide a mandrel for a pipe bending machine and the pipe bending machine to solve the technical problems of limited bending angle and difficult rotation of the mandrel for the pipe bending machine required for square pipe bending in the prior art.

[0006] ​Based on the above purpose, the present application provides a core rod for pipe bending machine, which comprises a connecting pipe and movable parts, the movable parts are connected with each other and the last movable part is fixedly connected to the connecting pipe, and the core rod further comprises: a liquid delivery pipe which is located in the connecting pipe and has an outer end connected to an external hydraulic pump; the movable parts are gradually thinner from top to bottom, and each movable part comprises an upper expansion plate and a lower contraction plate, and both sides of the expansion plate and the contraction plate are provided with support side plates; an intermediate connecting piece is arranged at the middle position of the movable parts, the expansion plate, the contraction plate and the support side plates are movably connected to the four sides of the intermediate connecting piece through telescopic rods, the intermediate connecting piece is provided with a telescopic groove and a hydraulic cavity, the telescopic rods are movably connected to the telescopic groove, the hydraulic cavity is filled with a hydraulic medium and is in communication with the telescopic groove, and an inner end of the liquid delivery pipe is connected to the hydraulic cavity.

[0007] Further, a connecting hose is fixedly connected to the intermediate connecting piece, and the hydraulic cavity in the intermediate connecting piece is in communication with the hydraulic cavity in the adjacent movable part through the connecting hose.

[0008] Further, a hinged part is fixedly connected to the intermediate connecting piece, and the adjacent movable parts are hinged through the hinged part.

[0009] Further, the movable parts are provided with a piece and arranged in a segmented manner, and the central axis of all the movable parts in the unbent state is collinear with the central axis of the connecting pipe.

[0010] Further, the thickness of the upper end of the expansion plate is 20-30mm, and the front and rear sides of the upper end of the expansion plate are provided with arc chamfers, and the thickness of the lower end of the contraction plate is 10-15mm.

[0011] And the pipe bending machine using the above core rod for pipe bending operation, which comprises a base and a pipe bending driving part, the output shaft of the pipe bending driving part is fixedly connected with a bending turntable, the side of the bending turntable is provided with a clamping groove matched with the size of the square pipe, the base is provided with a core rod rotating part, the output shaft of the core rod rotating part is fixedly connected with the connecting pipe of the core rod, and the core rod rotating part is used to drive the rotation of the whole core rod.

[0012] Further, the base is further provided with a limiting pneumatic cylinder, the output shaft of the limiting pneumatic cylinder is fixedly connected with a caterpillar track rotating frame, the front end of the caterpillar track rotating frame is rotatably connected with a self-rotating caterpillar track, and the self-rotating caterpillar track abuts against the square pipe to limit the square pipe in the clamping groove on the bending turntable.

[0013] Further, the positioning base is provided with a positioning assembly for clamping the square tube to fix it in the clamping groove of the bending turntable, the positioning base is fixedly connected with the output shaft of the bent pipe driving member, and the bottom of the positioning base is provided with a roller.

[0014] Further, the positioning assembly comprises a positioning cylinder and a positioning clamp, the positioning cylinder is fixedly installed on the upper end of the positioning base, and the positioning clamp is fixedly connected on the output shaft of the positioning cylinder.

[0015] Further, the base is also provided with a supporting slide rail, the square tube is movably connected on the supporting slide rail, and a roller is rotatably connected on the contact surface of the supporting slide rail and the square tube.

[0016] The beneficial effects of the present application are as follows: 1. The core rod is composed of a plurality of movable parts of the same size and shape, so that the core rod assembly can dynamically fit the pipe wall of different curvatures during bending, and an effective support is provided for the inner wall of the pipe, thereby effectively improving the problems of deformation and wrinkling during pipe bending, reducing the rebound phenomenon and improving the processing precision.

[0017] 2. The upper end of the movable part is thick, and the thickness becomes thinner from top to bottom. This makes the gap between the lower ends of adjacent movable parts larger and the gap between the upper ends smaller. During bending, it can ensure sufficient bending angle and provide sufficient support area.

[0018] 3. The movable part is composed of four supporting plates that can expand and contract, and the expansion and contraction of the four supporting plates are driven by hydraulic pressure. During normal use, a sufficient amount of hydraulic medium is injected to expand the four supporting plates to support the inner wall of the square tube. When the bending direction of the square tube changes, the hydraulic medium is removed to shrink the four supporting plates, so that the volume of the entire movable part becomes smaller and the square tube can rotate and adjust the angle. When the square tube is bent, the upper end of the expansion plate is matched with the stretched side wall of the square tube, and the lower end of the contraction plate is matched with the compressed side wall of the square tube.

[0019] 4. A pipe bending machine is also provided to automatically bend the square tube with the core rod. The pipe bending machine is provided with a limiting assembly and a positioning assembly to ensure the stability of the square tube during bending. The core rod rotating member can automatically adjust the angle of the core rod as needed to meet the bending operation of the square tube in all directions. BRIEF DESCRIPTION OF DRAWINGS

[0020] In order to more clearly illustrate the technical solutions in the present application or prior art, the following will briefly introduce the drawings needed to be used in the embodiments or prior art description. Obviously, the drawings in the following description are only a part of the present application, and other drawings can also be obtained by those skilled in the art without creative labor.

[0021] Figure 1 It is a structural schematic diagram of the conventional core rod for square tube bending.

[0022] Figure 2 It is a structural schematic diagram of the core rod for square tube bending in the device.

[0023] Figure 3 It is a structural schematic diagram of the movable part in the core rod of the device.

[0024] Figure 4 It is a structural schematic diagram of the internal structure of the movable part in the core rod of the device.

[0025] Figure 5 It is a schematic diagram of adjusting the angle of the core rod when the device is bending the square tube.

[0026] Figure 6 It is a structural schematic diagram of the pipe bender in the device.

[0027] Figure 7 It is a structural schematic diagram of the pipe bender in the device from another perspective.

[0028] Figure 8 It is a structural schematic diagram of the limiting assembly and the positioning assembly in the pipe bender of the device.

[0029] Figure 9 It is a schematic diagram of the square tube bending state in the device.

[0030] The marks in the figure are: 01, square tube, 02, core rod, 10, connecting pipe, 11, movable part, 12, infusion pipe, 111, expansion plate, 112, contraction plate, 113, support side plate, 114, intermediate connecting piece, 115, telescopic rod, 116, hinged part, 117, connecting hose, 118, telescopic groove, 119, hydraulic cavity, 120, base, 121, pipe bending driving piece, 122, bending turntable, 123, positioning base, 124, roller, 125, positioning cylinder, 126, positioning clamp, 127, limiting cylinder, 128, track rotating frame, 129, self-rotating track, 130, core rod rotating piece, 131, hydraulic pipe, 132, support slide rail, 133, roller. DETAILED DESCRIPTION

[0031] In order to make the purpose, technical scheme and advantages of the present application more clear and explicit, the present application is further described in detail below in combination with specific embodiments.

[0032] It should be noted that the technical terms or scientific terms used in the present application shall be the general meanings understood by those skilled in the art unless otherwise defined. The "first", "second" and similar words used in the present application do not represent any order, quantity or importance, but are only used to distinguish different components. "Include" or "contain" and similar words mean that the elements or objects before the word cover the elements or objects listed after the word and their equivalents, without excluding other elements or objects. "Connected" or "connected" and similar words are not limited to physical or mechanical connection, but can include electrical connection, whether direct or indirect. "Up", "down", "left", "right" and the like are only used to represent relative positional relationship, which may change accordingly when the absolute position of the described object changes.

[0033] The first aspect of the present application, since the existing needle for the pipe bending machine core rod, as shown in Figure 1 , is composed of a connecting rod and a plurality of movable support parts with the same size. Since the thickness of each movable part in the conventional pipe bending machine core rod is uniform, in order to obtain a larger bending angle, the gap between each movable part needs to be set larger, but the gap after the expansion of the outer side of the movable part will become larger, thus reducing the supporting area and weakening the supporting effect. Therefore, the present application designs a new type of pipe bending machine core rod, the specific structure is shown in Figure 2 、 Figure 3 and Figure 4 . It includes a connecting pipe 10 and a movable part 11, the movable part 11 is provided with a plurality of and is connected with each other, and the last side of the movable part 11 is fixedly connected to the connecting pipe 10, the core rod 02 further comprises: a liquid delivery pipe 12, the liquid delivery pipe 12 is located in the connecting pipe 10, and the outer end of the liquid delivery pipe 12 is connected to an external hydraulic pump.

[0034] Among them, the thickness of the movable part 11 from top to bottom is getting thinner and thinner, and the movable part 11 includes an expansion plate 111 on the top and a contraction plate 112 on the bottom, and the two sides of the expansion plate 111 and the contraction plate 112 are also provided with support side plates 113. The intermediate position of the movable part 11 is provided with an intermediate connecting piece 114, the expansion plate 111, the contraction plate 112 and the two side support side plates 113 are respectively movably connected on the four side surfaces of the intermediate connecting piece 114 through the telescopic rods 115, and the intermediate connecting piece 114 is provided with a telescopic groove 118 and a hydraulic cavity 119, the telescopic rod 115 is movably connected in the telescopic groove 118, the hydraulic cavity 119 is filled with hydraulic medium and is in communication with the telescopic groove 118, and the inner end of the liquid delivery pipe 12 is connected to the hydraulic cavity 119.

[0035] In addition, the intermediate connecting piece 114 is fixedly connected with a hinged part 116 and a connecting hose 117, and the adjacent movable part 11 is hinged through the hinged part 116, and the hydraulic cavity 119 in the intermediate connecting piece 114 is communicated with the hydraulic cavity 119 in the adjacent movable part 11 through the connecting hose 117.

[0036] Preferably, the movable part 11 is provided with 12-20 pieces and arranged in a segmented mode, and the central axis of all the movable parts 11 in the unbent state is in line with the central axis of the connecting pipe 10.

[0037] The upper end of the movable part 11 is thick, and the thickness becomes thinner downwards. This makes the gap between the lower ends of the adjacent movable parts larger and the gap between the upper ends smaller. When being bent, sufficient bending angle can be ensured, and sufficient supporting area can be provided.

[0038] The expansion plate 111, the contraction plate 112 and the two side supporting side plates 113 are respectively movably connected to the four sides of the intermediate connecting piece 114 through the telescopic rods 115. The expansion plate 111, the contraction plate 112 and the two side supporting side plates 113 can be telescopic and driven by hydraulic pressure. In normal use, sufficient hydraulic medium is injected into the hydraulic cavity 119 in each movable part 11 through the hydraulic pipe 131 and the infusion pipe 12 to make the expansion plate 111, the contraction plate 112 and the two side supporting side plates 113 expand to support the inner wall of the square pipe 01 and provide supporting effect.

[0039] When the bending direction of the square pipe is changed, the hydraulic medium is drawn out to make the expansion plate 111, the contraction plate 112 and the two side supporting side plates 113 contract, so that the volume of the whole movable part 11 becomes smaller and can rotate in the square pipe 01 to adjust the angle. When the square pipe 01 is bent, the upper end of the expansion plate 111 is matched with the stretched side wall of the square pipe 01, and the lower end of the contraction plate 112 is matched with the compressed side wall of the square pipe 01. Figure 5

[0040] The second aspect of the present application is shown in Figure 6 , Figure 7 and Figure 8 , a pipe bending machine cooperating with the above-mentioned core rod 02 is also designed. Specifically, it comprises a base 120 and a pipe bending driving part 121, and the output shaft of the pipe bending driving part 121 is fixedly connected with a bending turntable 122, the side of the bending turntable 122 is provided with a clamping groove matched with the size of the square pipe 01, the base 120 is provided with a core rod rotating part 130, and the output shaft of the core rod rotating part 130 is fixedly connected with the connecting pipe 10 of the core rod 02, for driving the rotation of the whole core rod 02. ​

[0041] The base 120 is further provided with a limiting cylinder 127, the output shaft of the limiting cylinder 127 is fixedly connected with a caterpillar track support frame 128, the front end of the caterpillar track support frame 128 is rotatably connected with a self-rotating caterpillar track 109, the self-rotating caterpillar track 109 abuts against the square tube 01, and is used for limiting the square tube 01 in the clamping groove on the bending turntable 122.

[0042] When bending, the pipe bending driving member 121 drives the bending turntable 122 to rotate, and the square tube 01 is subjected to pipe extraction bending, so that the square tube 01 is displaced by a certain distance, and the self-rotating caterpillar track 109 abuts against the square tube 01 to provide sufficient supporting force for limiting and can rotate with the square tube 01, so as not to affect the displacement of the square tube 01.

[0043] In addition, a positioning base 123 is further provided, the positioning base 123 is provided with a positioning assembly for clamping the square tube 01 to fix the square tube 01 in the clamping groove on the bending turntable 122, the positioning base 123 is fixedly connected with the output shaft of the pipe bending driving member 121, and the bottom of the positioning base 123 is provided with a roller 124. The positioning assembly comprises a positioning cylinder 125 and a positioning clamp 126, the positioning cylinder 125 is fixedly installed on the upper end of the positioning base 123, and the positioning clamp 126 is fixedly connected with the output shaft of the positioning cylinder 125.

[0044] The positioning base 123 can rotate synchronously with the bending turntable 122, so that the positioning assembly can always ensure the positioning effect.

[0045] Preferably, the base 120 is further provided with a supporting slide rail 132, the square tube 01 is movably connected with the supporting slide rail 132, and the contact surface of the supporting slide rail 132 is further rotatably connected with a roller 133. The core rod rotating member 130 can automatically adjust the angle of the core rod 02 as required, and meet the rotation of the square tube 01 in various directions. Finally, the square tube 01 can be bent in various directions, as shown in the figure. Figure 9

[0046] As described above, the upper end of the movable part 11 in the core rod 02 is thick, and the thickness becomes thinner from top to bottom. This makes the gap between the lower ends of adjacent movable parts larger, and the gap between the upper ends smaller. When bending, sufficient bending angle can be ensured, and sufficient supporting area can be provided. In addition, the whole core rod 02 can be expanded and contracted to adjust the volume. When the volume of the core rod 02 becomes smaller, the core rod 02 can rotate in the square tube 01 to adjust the angle. When the square tube 01 is bent, the expanded plate 111 with the upper end thicker cooperates with the stretched side wall of the square tube 01, and the contracted plate 112 with the lower end thinner cooperates with the compressed side wall of the square tube 01.

[0047] ​And the designed pipe bending machine can cooperate with the core rod 02 to automatically bend the square tube 01, the limiting assembly and the positioning assembly are arranged in the pipe bending machine, so that the stability of the square tube during bending is ensured. The core rod rotating piece 130 can automatically adjust the angle of the core rod 02 according to the needs, and meet the bending operation of the square tube 02 in each direction.

[0048] Those skilled in the art should understand that the above discussion of any embodiment is only exemplary, and is not intended to imply that the scope of the present application includes the claims limited to these examples; the technical features in the above embodiments or different embodiments can also be combined, the steps can be implemented in any order, and there are many other changes of different aspects of the present application as described above. In order to be brief, they are not provided in details.

[0049] The present application is intended to cover all such alternatives, modifications, and variations as fall within the broad scope of the appended claims. Accordingly, any and all such modifications, variations, and equivalents that fall within the spirit and scope of the present application are intended to be included within the scope of the claims.

Claims

1. A mandrel for a pipe bending machine, comprising a connecting pipe (10) and movable parts (11), said movable parts (11) being connected to each other in rotation and the last movable part (11) being fixedly connected to the connecting pipe (10), characterized in that, The core rod further comprises: The infusion pipe (12) is located in the connecting pipe (10), and the outer end of the infusion pipe (12) is connected to an external hydraulic pump; The movable part (11) is thinner from top to bottom, and comprises an upper expansion plate (111) and a lower contraction plate (112), and the two sides of the expansion plate (111) and the contraction plate (112) are further provided with support side plates (113); An intermediate connecting piece (114) is arranged at the middle position of the movable part (11), the expansion plate (111), the contraction plate (112) and the two support side plates (113) are respectively movably connected to the four side surfaces of the intermediate connecting piece (114) through telescopic rods (115), and the intermediate connecting piece (114) is internally provided with a telescopic groove (118) and a hydraulic cavity (119), the telescopic rod (115) is movably connected in the telescopic groove (118), the hydraulic cavity (119) is filled with a hydraulic medium and is in communication with the telescopic groove (118), and the inner end of the infusion pipe (12) is connected to the hydraulic cavity (119).

2. A mandrel for a tube bender as defined in claim 1, wherein The intermediate connecting piece (114) is further fixedly connected with a connecting hose (117), and the hydraulic cavity (119) in the intermediate connecting piece (114) is in communication with the hydraulic cavity (119) in the adjacent movable part (11) through the connecting hose (117).

3. A mandrel for a tube bender as defined in claim 1, wherein The intermediate connecting piece (114) is further fixedly connected with a hinged part (116), and the adjacent movable parts (11) are hinged through the hinged part (116).

4. A mandrel for a tube bender as defined in claim 1, wherein The movable part (11) is provided with 12-20 pieces and arranged in a segmented manner, and the central axis of all the movable parts (11) in the unbent state is collinear with the central axis of the connecting pipe (10).

5. A mandrel for a tube bender as defined in claim 1 wherein, The thickness of the upper end of the expansion plate (111) is 20-30 mm, and the front and rear sides of the upper end of the expansion plate (111) are provided with arc chamfers, and the thickness of the lower end of the contraction plate (112) is 10-15 mm.

6. A pipe bender for performing a pipe bending operation using the mandrel according to any one of claims 1 to 5, characterized by The base (120) and the pipe bending driving part (121) are provided, the output shaft of the pipe bending driving part (121) is fixedly connected with a bending turntable (122), the side of the bending turntable (122) is provided with a clamping groove matched with the size of the square pipe (01), the base (120) is provided with a core rod rotating part (130), the output shaft of the core rod rotating part (130) is fixedly connected with the connecting pipe (10) of the core rod (02), and is used to drive the rotation of the whole core rod (02).

7. A tube bender as defined in claim 6, wherein The base (120) is further provided with a limiting pneumatic cylinder (127), the output shaft of the limiting pneumatic cylinder (127) is fixedly connected with a caterpillar track rotating frame (128), the front end of the caterpillar track rotating frame (128) is rotatably connected with a self-rotation caterpillar track (109), and the self-rotation caterpillar track (109) abuts against the square pipe (01) to limit the square pipe (01) in the clamping groove on the bending turntable (122).

8. A tube bender according to claim 6, wherein Also include positioning base (123), the positioning base (123) is equipped with positioning assembly, is used for clamping square tube (01) to make it fixed in the clamping groove of bending turntable (122), the positioning base (123) is fixedly connected with the output shaft of bent pipe driving element (121), and the bottom of positioning base (123) is provided with a roller (124).

9. A tube bender as defined in claim 8, wherein The positioning assembly comprises a positioning cylinder (125) and a positioning clamp (126), the positioning cylinder (125) is fixedly installed on the upper end of the positioning base (123), and the positioning clamp (126) is fixedly connected to the output shaft of the positioning cylinder (125).

10. The mandrel for a tube bender and the tube bender of claim 6 wherein, The base (120) is also provided with a supporting slide rail (132), the square tube (01) is movably connected to the supporting slide rail (132), and a roller (133) is rotatably connected to the contact surface of the supporting slide rail (132) and the square tube (01).

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