An installation structure for combined compression deformation of the axial tangential diameter of metal round tubes

Abstract

This invention provides an installation structure for combined compression deformation of metal round tubes. Four extrusion dies are symmetrically fixedly connected to the lower part of a top plate. Movable blocks are connected to the lower ends of the extrusion dies to form an extrusion module. A central circular hole is designed in the middle of the fixture for the passage of a cross rib plate and the metal round tube. Four movable blocks are installed on the upper surface of the fixture and are symmetrically distributed in a ring around the central circular hole. Four cutting tools are fixed on the lower surface of the fixture, with each cutting tool positioned between the fixed positions of two adjacent movable blocks. The bottom surface of the cross rib plate is fixedly connected to the lower base plate. This invention ensures precise positioning of each component, simultaneous operation of multiple dies, stable and non-eccentric load at the force-bearing end, and allows the metal tube to deform according to the expected plastic deformation mode to absorb a large amount of energy. The proposed device has the advantages of accurate positioning, reliable installation, easy disassembly, reusability, and stable force application.

Description

Technical Field

[0001] This invention provides an installation structure for combined compression deformation of the axial tangential diameter of metal round tubes, belonging to the field of metal pipe forming technology. Background Technology

[0002] In recent years, the construction of high-speed railways both domestically and internationally has developed rapidly, but railway vehicle collision accidents continue to occur. Therefore, research on improving the passive safety protection capabilities of locomotives and rolling stock is particularly important, considering how to quickly reduce the impact loads during collisions and other accidents, stably dissipate the significant energy generated by such collisions, and effectively mitigate the damage to locomotives and rolling stock in impacts.

[0003] While most passive safety measures for locomotives and rolling stock rely on single deformation modes such as compression of thin-walled metal tubes and porous structures, cutting of thick metal tubes, and tearing of new composite materials, the increasing speed of trains and stricter safety standards have rendered single energy-absorbing structures increasingly inadequate for practical production needs. This has led to the emergence of novel combined energy-absorbing models that integrate multiple energy absorption methods. These combined energy-absorbing devices, by combining the advantages of various energy absorption methods, possess superior energy absorption characteristics and better meet the crashworthiness requirements of locomotive and rolling stock structures, thus gaining increasing favor among researchers.

[0004] Based on existing research results on energy absorption methods, it is known that it is reliable to absorb energy generated by collision by axial cutting of metal pipes to form chip deformation and radial extrusion to form grooves. The two energy absorption methods have similar energy absorption characteristics and it is feasible to use them in a single energy absorption device. However, how to couple the two energy absorption methods together to obtain a combined energy absorption device with better energy absorption characteristics will become an important research topic.

[0005] Existing device structural design, such as Figure 14 While it only considered innovations in the design of energy-absorbing devices for use in rear-end collisions, it is essentially still a device structure design that only considers cutting-type energy absorption, resulting in a single energy absorption method. Furthermore, the cutting tool is fixed on the guide post, leading to complex manufacturing processes and low reliability; and although the energy-absorbing component is a hollow energy-absorbing post, the designed guide component is a solid guide post, resulting in poor energy absorption efficiency. Summary of the Invention

[0006] This invention provides an installation structure for combined axial-tangential compression deformation of metal round tubes, aiming to achieve axial shear force to form chips and radial force to cause inward concavity in the metal tube. This scheme ensures precise positioning of each component, simultaneous operation of multiple molds, stability and non-eccentric loading at the force-bearing end, and allows the metal tube to absorb a large amount of energy through plastic deformation according to the expected pattern. The proposed device has the advantages of accurate positioning, reliable installation, easy disassembly, reusability, and stable force application.

[0007] An installation structure for combined compression deformation of axial diameter of metal round tubes includes an upper panel, an extrusion die, a movable block, a partition, a clamp, a cutting tool, a cross rib, a metal round tube, and a lower base plate;

[0008] Four extrusion dies are symmetrically and fixedly connected to the underside of the top plate;

[0009] The lower end of the extrusion die is connected to a movable block, forming a modular whole, namely the extrusion module; the connection is equipped with reinforcing ribs;

[0010] The fixture has a central circular hole for the passage of cross ribs and metal tubes;

[0011] Four movable blocks are installed on the upper surface of the fixture and are symmetrically distributed in a ring around the central hole. A partition is also provided between the movable blocks and the fixture.

[0012] Four cutting tools are fixed on the lower surface of the fixture, and the four cutting tools are symmetrically distributed in a ring around the central circular hole of the fixture.

[0013] The fixed position of each cutting tool on the fixture is located in the middle of the fixed positions of two adjacent movable blocks on the fixture;

[0014] The sides of the cross rib plate are designed with rounded transitions, and the bottom surface of the cross rib plate is fixedly connected to the bottom plate.

[0015] The metal tube is fitted over the cross rib plate, with its inner wall in contact with the side of the cross rib plate. The side of the cross rib plate is placed at a 0° angle to the cutting tool and at a 45° angle to the extrusion die, so that the cutting tool is supported by the cross rib plate when cutting the metal tube. The extrusion die leaves a space between the adjacent ribs of the cross rib plate when extruding the metal tube, ensuring the stable deformation of the metal tube.

[0016] The four extrusion dies are designed with smooth rounded corners on the inner side of the axis of the central hole of the fixture.

[0017] The cutting tool is fixed to the fixture by an internal hex screw, and the back of the tool and the tip of the tool are smoothly transitioned by a rounded corner.

[0018] Compared with the prior art, the structure of the present invention has the following main advantages:

[0019] (1) Innovation in energy absorption methods

[0020] The structural design of this device comprehensively considers the advantages and disadvantages of the two commonly used plastic deformation methods for metal pipe fittings (cutting and extrusion), and cleverly couples them together from the perspective of plastic deformation mechanism. The advantages of one method cover the disadvantages of the other, achieving a powerful combination. Both axial cutting and radial extrusion have the characteristics of large deformation in a small area and frictional heat dissipation to assist plastic deformation, exhibiting excellent coupling adaptability. In addition, axial cutting has the characteristics of low initial peak force, fast plateau force response, and small load fluctuation, but a small adjustable range of plateau force. Radial extrusion has the characteristics of low initial peak force, large adjustable range of plateau force, and small load fluctuation, but a slow plateau force response. This device rationally and completely enables the metal tube to complete the combined axial-to-radial compression plastic deformation by staggered assembly of the cutting tool and extrusion die, while using cross ribs to position and fix the metal tube. During the entire plastic deformation process, the metal tube first undergoes cutting deformation under the action of the cutting tool, rapidly entering the plateau force stage (i.e., the first stage of energy absorption) by utilizing the rapid response of the plateau force. Then, it undergoes extrusion deformation under the action of the extrusion die. At this point, the metal tube is simultaneously subjected to cutting and extrusion forces. The force of the device gradually stabilizes and increases, then enters the second plateau force stage (i.e., the second stage of energy absorption) until the cutting tool is about to touch the lower base plate. At this point, the axial tangential compression operation of the entire device ends, completing one energy absorption response. The structural design of this device fully utilizes the characteristic that both axial cutting and radial extrusion deformation modes are characterized by large deformation over small areas. Through staggered arrangement, the metal tube and the device are in full contact, significantly increasing the stress range of the metal tube. Simultaneously, the cross ribs regulate and constrain the deformation behavior of the metal tube, making the deformation mode more conducive to large deformation over large areas. This fully utilizes the material, significantly improving energy absorption efficiency, resulting in an energy absorption device with rapid response, stable load, low peak force, large plateau force, and multi-stage response energy absorption characteristics.

[0021] (2) Innovation in device structural design

[0022] This device design not only considers innovative energy absorption methods but also addresses structural design issues. Unlike previous methods that relied solely on axial cutting and radial compression, this device combines both. This means the design must account for both the chip curling caused by axial cutting and the inward concavity of the metal tube due to radial compression. To rationally couple these two energy absorption methods, a thick plate with grooves on both sides is used as a clamp. A circular gap at the center of the clamp provides internal space for the movement of the metal tube. The cutting tool features a front and rear angle design. The front angle allows the cutting edge to curl smoothly and transition onto the tool back, while the rear angle ensures that only the tool tip contacts the metal tube, facilitating chip removal. Smooth fillets between the tool tip and the tool back prevent jamming caused by chips obstructing the tool. The radial extrusion section is designed using an extrusion module comprised of an extrusion die, reinforcing ribs, and a movable block. This modular design allows for rapid disassembly and mass production. The reinforcing ribs help balance the oblique loads and bending torques experienced by the extrusion module under working conditions. The movable block increases the contact area between the extrusion module and the fixture, improving the overall structural stability and facilitating the axial transmission of impact loads. Furthermore, the combination of the partition plate and the movable block allows for a simpler and more convenient change in the assembly orientation of the extrusion module, thereby altering the extrusion depth of the metal tube. The cross rib design provides support to prevent bending deformation when the cutting tool acts on the metal tube, regulates and constrains its deformation pattern when the extrusion die acts on it, and also positions and fixes the metal tube during the initial assembly stage—a single plate serving three purposes. Attached Figure Description

[0023] Figure 1 This is a schematic diagram of the axial tangential pressure combined energy absorption device of the present invention;

[0024] Figure 2 This is a schematic diagram of the installation and positioning part of the shaft diameter pressing die of the present invention;

[0025] Figure 3 This is a schematic diagram of the metal round tube mounting and positioning part of the present invention;

[0026] Figure 4 This is a schematic diagram of the extrusion module structure of the present invention;

[0027] Figure 5 This is a schematic diagram of the extrusion die structure of the present invention;

[0028] Figure 6 This is a schematic diagram of the reinforcing rib structure of the present invention;

[0029] Figure 7 This is a schematic diagram of the active block structure of the present invention;

[0030] Figure 8 This is a schematic diagram of the upper panel structure of the present invention;

[0031] Figure 9 This is a schematic diagram of the clamp (front) structure of the present invention;

[0032] Figure 10 This is a schematic diagram of the clamp (reverse side) structure of the present invention;

[0033] Figure 11 This is a schematic diagram of the cutting tool structure of the present invention;

[0034] Figure 12 This is a schematic diagram of the partition structure of the present invention;

[0035] Figure 13 This is a schematic diagram of the cross rib structure of the present invention;

[0036] Figure 14 The existing device structural design drawing shows: 31, guide column; 32, cutting block; 33, energy-absorbing column; 34, connecting piece; 331, elongated hole. Detailed Implementation

[0037] The specific technical solution of the present invention will be described in conjunction with the accompanying drawings.

[0038] An installation structure for axial tangential compression deformation of metal round tubes mainly consists of an upper panel 1, an extrusion die 2, reinforcing ribs 3, a movable block 4, a partition 5, a clamp 6, a cutting tool 7, a cross rib 8, a metal round tube 9, a lower base plate 10, flat head screws 11, and socket head cap screws 12, etc., with an overall shape as shown. Figure 1 As shown, the specific structure will be described in detail below.

[0039] 1. Mold installation and positioning parts, such as Figure 2 As shown:

[0040] The upper panel 1 and the extrusion die 2 are connected and fixed by flat-head screws 11 passing through the first screw hole 100 of the extrusion die 2 and the second screw hole 200 of the upper panel 1, as shown. Figure 5 As shown and Figure 8 As shown, the flat-head screw 11 facilitates the implementation of impact loads. The extrusion die 2 is fixed to the reinforcing rib 3 and the movable block 4 by welding, forming a modular whole, namely the extrusion module, as shown. Figure 4 As shown.

[0041] like Figure 5 The extrusion die 2 shown has smooth rounded corners 21 on both sides. This allows the metal tube 9 to move smoothly and stably during the extrusion process, preventing it from being cut or torn. Figure 6As shown, the reinforcing rib 3 in the extrusion module can balance the torque and impact load on the extrusion die 2. The movable block 4 and the clamp 6 are connected and fixed on the front by hexagon socket screws 12 through the third screw hole 300 of the movable block 4 and the fourth screw hole 400 of the clamp 6. Figure 7 As shown, Figure 9 As shown; in addition, a fifth screw hole 500 is designed on the side of the recessed area on the front of the fixture 6, as shown. Figure 12 As shown, it can be connected and fixed to the sixth screw hole 600 on the partition 5 by the internal hex screw 12. At the same time, the partition 5 is used to position the extrusion module and prevent the extrusion module from rotating outward and tilting.

[0042] Fixture 6 is used to simultaneously fix the extrusion module and the cutting tool 7, such as Figure 5 As shown, the fixture 6 has a central circular hole in the middle, allowing the cross rib plate 8 and the metal tube 9 to pass through. The cutting tool 7 has three eighth screw holes 800 on its back 71, as shown... Figure 11 As shown, the reverse side of fixture 6 has a seventh screw hole 700, as... Figure 10 As shown, the cutting tool 7 is connected and fixed to the fixture 6 by an internal hex screw 12, and the back of the tool 71 and the tip of the tool 72 are smoothly transitioned by a rounded corner, as shown. Figure 11 As shown, to prevent the tip 72 from cracking due to stress concentration, the height of the back of the cutter 71 is designed to be slightly higher than the tip 72. The purpose is to ensure that the back of the cutter 71 contacts the lower base plate 10 before the tip 72, thus protecting the cutting tool 7 and the lower base plate 10.

[0043] The fixed position of each cutting tool 7 on the fixture 6 is located in the middle of the fixed positions of two adjacent movable blocks 4 on the fixture 6;

[0044] The mold positioning and installation part completes the positioning of the core working components extrusion mold 2 and cutting tool 7 through the clamp 6. When the upper panel 1 is subjected to pressure, it ensures that the cutting force and extrusion force are loaded along the axial direction, and will not cause side overturning or oblique loading due to the fact that several cutting tools 7 or extrusion mold 2 do not act on the metal round tube 9 at the same time.

[0045] 2. The metal round tube installation and positioning part, such as Figure 3 As shown:

[0046] like Figure 13The cross rib plate 8 shown has a rounded transition on its sides, which allows for a more complete connection with the metal tube 9. The side edges of the rib plate are all rounded to prevent scratching or tearing of the metal tube 9, thus affecting the deformation process. The bottom surface of the cross rib plate 8 has four bolt holes for assembly with the lower base plate 10, secured with flat-head bolts. This ensures stable contact between the lower base plate 10 and the outside environment, guaranteeing the stability of the entire device during operation and preventing tipping. The sides of the cross rib plate 8 are placed at a 0° angle to the cutting tool 7 and a 45° angle to the extrusion die 2. This provides support for the cutting tool 7 when cutting the metal tube 9, preventing the metal tube 9 from bending and becoming unstable. The extrusion die 2 provides sufficient space between the ribs of the cross rib plate 8 when extruding the metal tube 9, ensuring stable deformation of the metal tube 9. The inner diameter of the metal tube 9 is slightly larger than the width of the cross rib plate 8; the gap between them should not be too large, ideally preventing slight wobbling of the metal tube 9.

[0047] The following parts of this device can be modified: the cutting depth of the metal tube 9 is controlled by the cutting tool 7; changing the length of the cutting tool's back 71 alters the cutting depth. The extrusion depth of the metal tube 9 is controlled by the partition plate 5; changing the thickness of the partition plate 5 yields different extrusion depths to suit various applications. Furthermore, the width of the cutting tool 7 and the width of the cross rib plate 8 can be set to several different values, thereby adjusting the cutting force and extrusion force respectively. Simultaneously, the shape (including parameters such as the rake angle, clearance angle, width, and length) and number of the cutting tools 7, as well as the shape (including parameters such as the height, length, width, and side tilt angle of the extrusion die 2), and number of the extrusion die 2 can all be adjusted.

[0048] The working principle of this invention is as follows:

[0049] The loading end of the impact load is located at the upper panel 1, which has flat-head bolt holes. The entire upper panel 1 is in the same plane, allowing the loading end of the impact load to contact the upper panel 1 evenly. This ensures that the entire device can withstand axial load impact and avoids deflection due to uneven force. The extrusion die 2, reinforcing rib 3, movable block 4, partition 5, clamp 6, and cutting tool 7 move vertically downwards along the upper panel 1 due to the movement of the impact load. The metal tube 9 is fixed by the cross rib plate 8 to prevent deflection. The metal tube 9 is first subjected to the cutting force from the cutting tool 7, producing chips. The chips curl inwards along the smooth transition between the tool tip 72 and the tool back 71. The metal tube 9 is then subjected to the pressure from the extrusion die 2 and the cross rib plate 8, causing it to indent inwards along the side of the cross rib plate 8, forming a groove.

[0050] As the clamp 6 moves downward, more and more chips are produced and the grooves become longer and longer. The metal tube 9 absorbs energy by the plastic deformation energy generated by the axial tangential pressure and the heat energy dissipated by friction.

[0051] When the cutting tool 7 is about to contact the lower base plate 10, the entire axial tangential compression deformation process ends, completing one energy absorption response.

[0052] The extrusion die 2, reinforcing rib 3, and movable block 4 adopt a modular design, which has the advantages of quick assembly and disassembly and structural stability. In addition, the cutting tool 7, cross rib 8, and metal round tube 9 are all replaceable, and the whole device has excellent disassembly.

[0053] This device cleverly and flexibly couples axial cutting and radial extrusion together, representing a novel method of energy absorption through plastic deformation. The force is relatively stable and exhibits a stepped energy level response.

Claims

1. An installation structure for a combined axial cutting and radial pressing deformation of a metal round pipe, characterized by, The extrusion die (2), the movable block (4), the partition (5), the clamp (6), the cutting tool (7), the cross rib plate (8), and the lower bottom plate (10) are arranged on the upper plate (1). The four extrusion dies (2) are symmetrically fixed below the upper plate (1). The lower end of the extrusion die (2) is connected with the movable block (4) to form a modular whole, namely the extrusion module. The center circular hole is designed in the middle of the clamp (6) for the cross rib plate (8) and the metal circular pipe (9) to pass through. The four movable blocks (4) are installed on the upper surface of the clamp (6) and are symmetrically distributed in a ring around the center circular hole. The four cutting tools (7) are symmetrically distributed in a ring around the center circular hole of the clamp (6). The fixed position of each cutting tool (7) on the clamp (6) is located in the middle of the fixed positions of the adjacent two movable blocks (4) on the clamp (6). The rib plate side of the cross rib plate (8) is designed with a circular arc transition, and the bottom surface of the cross rib plate (8) is fixedly connected with the lower bottom plate (10). The metal circular pipe (9) is sleeved outside the cross rib plate (8), and the inner wall is in contact with the rib plate side of the cross rib plate (8).

2. The mounting structure for combined deformation of axis cutting and diameter reducing of a metal round pipe according to claim 1, wherein The rib plate side of the cross rib plate (8) is placed at a 0° angle with the cutting tool (7) and at a 45° angle with the extrusion die (2), so that the cutting tool (7) has the cross rib plate (8) as support when cutting the metal circular pipe (9).

3. The mounting structure for combined deformation of axis cutting and diameter reducing of a metal round pipe according to claim 1, wherein The extrusion die (2) leaves a moving space between the adjacent ribs of the cross rib plate (8) when extruding the metal circular pipe (9), which ensures the stable deformation of the metal circular pipe (9). The inner side of the four extrusion dies (2) facing the center circular hole axis of the clamp (6) is designed with a smooth round corner (21). The cutting tool (7) is connected and fixed on the clamp (6) through the inner hexagonal screw (12), and the back (71) and the tip (72) are smoothly transitioned through the round corner.

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