Shearing and compression combined energy absorber

Abstract

The invention discloses a shearing and compressing combined energy absorber which comprises a flat pressing cap, an actuating cap, a cutter and a fiber composite material pipe, wherein the flat pressing cap and the actuating cap are positioned at the upper end and the lower end; the cutter is positioned in the actuating cap; the cutter comprises a cylinder and a cutting blade in the cylinder, the upper end of the fiber composite pipe is fixedly connected with the lower end of the flat pressing cap, the lower end of the fiber composite pipe is inserted into the upper end of the cylinder in a matched mode and abuts against the cutting blade, the actuating cap, the cylinder and the fiber composite pipe are connected together through a shear pin, and the lower end of the cylinder is fixedly connected with the actuating cap. The flat pressing cap is used for pressing the fiber composite pipe downwards after the shear pin is damaged by impact load and is inserted into the actuating cap in a matched mode, the inner bottom face of the actuating cap is provided with a guide curved face used for guiding strips formed by cutting the composite pipe to turn upwards, and the cutting piece and the upper portion of the cylinder are of a thin-wall structure capable of being crushed by the flat pressing cap. The lower portion of the cylinder is of a thickened structure capable of limiting the stroke of the flat pressing cap. According to the energy absorber, two energy absorption modes of shearing and compression are combined, and efficient transmission and dissipation of energy can be achieved.

Description

Technical Field

[0001] The invention relates to an energy absorber, in particular to a shear and compression combined energy absorber. Background Art

[0002] The working principle of energy absorbers usually involves processes such as plastic deformation, fracture or friction of materials, through which the impact energy is converted into other forms of energy and dissipated. They are widely used as key components in the aviation field and play an important role in aircraft takeoff and landing, emergency landing, collision protection, and helicopter seat cushioning.

[0003] Currently, the common types of aircraft seat energy absorbers mainly include extruded tube expansion energy absorber assemblies, flip tube energy absorber assemblies, rolling ring energy absorbers, crushed circular tube energy absorbers, cutting energy absorbers, etc. These energy absorbers have their own characteristics and are widely used in various aircraft seat designs. However, these single forms of energy absorbers often have some limitations. For example, the impact resistance of cutting energy absorbers is relatively limited. Especially under high-energy impact, plastic failure or fracture is prone to occur, resulting in a decrease in energy absorption effect; crushed circular tube energy absorbers often require a large space, and in some cases, their energy absorption efficiency is not as good as that of cutting energy absorbers. Summary of the invention

[0004] The object of the present invention is to provide a shear and compression combined energy absorber, which combines the two energy absorption modes of shear and compression to achieve efficient energy transmission and dissipation.

[0005] The technical solution adopted by the present invention is: A shear and compression combined energy absorber, comprising a flat pressure cap and an actuating cap located at upper and lower ends, a cutter located in the actuating cap, and a fiber composite material tube for being cut and compacted; the cutter comprises a cylinder with openings at both ends and a cutting blade axially arranged in the cylinder, the upper end of the fiber composite material tube is fixedly connected to the lower end of the flat pressure cap, and the lower end is inserted into the upper end of the cylinder and abuts against the cutting blade, the upper end of the actuating cap, the upper end of the cylinder, and the lower end of the fiber composite material tube are connected together by a shear pin, and the lower end of the cylinder is fixedly connected to the actuating cap; the flat pressure cap is used to press down the fiber composite material tube after the impact load destroys the shear pin and is inserted into the actuating cap itself, a guiding curved surface is provided on the inner bottom surface of the actuating cap for guiding the strips cut from the composite material tube to flip upward, the cutting blade and the upper part of the cylinder are thin-walled structures that can be crushed by the flat pressure cap, and the lower part of the cylinder is a thickened structure that can limit the stroke of the flat pressure cap.

[0006] Preferably, a positioning ring is also included. There is an annulus between the cylinder and the actuating cap. The positioning ring fits in the annulus and is connected with the upper end of the actuating cap, the upper end of the cylinder, and the lower end of the position-limiting composite material pipe through the shear pin. After the shear pin is broken, the positioning ring falls into the bottom end of the annulus. The annulus is used to accommodate the upper material of the cylinder crushed by the flat pressure cap. The positioning ring is made of metal material.

[0007] Preferably, the upper end of the thickened structure at the lower part of the cylinder is a guide fillet capable of guiding the strips cut from the composite material tube to deviate inwards.

[0008] Preferably, the guide curved surface is annular and surrounds the inner bottom surface of the actuating cap, and its cross section is semicircular.

[0009] Preferably, the cutting blade is in a grid shape and extends to the lower end of the cylinder.

[0010] Preferably, the lower end surface of the flat pressure cap is provided with a slot, the outer diameter of which matches the inner diameter of the actuating cap, and the upper end of the fiber composite material tube is inserted into the slot and fixedly connected by screws.

[0011] Preferably, the lower end of the cylinder is fixedly connected to the actuating cap by means of screws.

[0012] Preferably, the flat pressure cap, the actuating cap and the cutter are made of metal materials.

[0013] Preferably, ears for external installation are provided at the upper end of the flat pressure cap and the lower end of the actuating cap.

[0014] The beneficial effects of the present invention are: The energy absorber combines the two energy absorption methods of shear and compression to achieve efficient energy transfer and dissipation: when subjected to impact load, the fiber composite material tube is not only cut by the cutting blade, but also squeezed between the flat pressure cap and the actuating cap, causing the fiber composite material to tear, bend, delaminate, and break, thereby absorbing energy. In addition, the thin-walled section on the upper part of the cutter is crushed and plastically deformed, thereby absorbing energy. In addition, the friction generated between the fiber composite material and the thin-walled section on the upper part of the cutter during movement can also absorb impact energy. BRIEF DESCRIPTION OF THE DRAWINGS

[0015] Figure 1 It is a schematic diagram of the decomposition of the shear and compression combined energy absorber.

[0016] Figure 2 It is a cross-sectional view of the shear and compression combined energy absorber when it is not subjected to impact load.

[0017] Figure 3 It is a cross-sectional view when the lower end surface of the flat pressure cap in the shear and compression combined energy absorber contacts the upper end surface of the cylinder.

[0018] Figure 4 It is a cross-sectional view of the shear and compression combined energy absorber when the flat pressure cap is inserted into the actuating cap a certain distance.

[0019] In the figure: 1-flat pressure cap; 2-fiber composite material tube; 21-strip; 3-positioning ring; 4-cutter; 41-cylinder; 42-cutting blade; 5-actuating cap; a-mounting hole of shear pin; b-guide curved surface; c-guide fillet; d-annulus. DETAILED DESCRIPTION

[0020] The present application is further described below in conjunction with the accompanying drawings and embodiments.

[0021] The present application provides a shear and compression combined energy absorber, the purpose of which is to combine the two energy absorption modes of shear and compression to achieve efficient energy transfer and dissipation, such as Figures 1 to 4 As shown, it includes a flat pressure cap 1, an actuating cap 5, a cutter and a fiber composite material tube 2; wherein: the flat pressure cap 1 and the actuating cap 5 are located at the upper and lower ends, see Figures 1 to 4 The cutter is located in the actuator cap 5, and the cutter includes a cylinder 41 and a cutting blade 42. The cylinder 41 is open at both ends, and the cutting blade 42 is axially arranged in the cylinder 41. The cutting blade 42 and the upper part of the cylinder 41 are thin-walled structures that can be crushed by the flat pressure cap 1, and the lower part of the cylinder 41 is a thickened structure that can limit the stroke of the flat pressure cap 1. Figures 1 to 4 The fiber composite material tube 2 is used to be cut and compacted. The upper end of the fiber composite material tube 2 is fixedly connected to the lower end of the flat pressure cap 1, and the lower end is inserted into the upper end of the cylinder 41 and abuts against the cutting blade 42. The upper end of the actuating cap 5, the upper end of the cylinder 41, and the lower end of the fiber composite material tube 2 are connected together by a shear pin. The lower end of the cylinder 41 is fixedly connected to the actuating cap 5. Figures 1 to 4 The flat pressure cap 1 is used to press down the fiber composite material tube 2 after the impact load destroys the shear pin and cooperates with the actuating cap 5 to be inserted. The inner bottom surface of the actuating cap 5 is provided with a guiding curved surface b for guiding the composite material tube 2 to be cut into strips 3 to flip upward. Figures 2 to 4 . The energy absorber combines the two energy absorption modes of shearing and compression to achieve efficient energy transfer and dissipation: when subjected to impact load, the fiber composite material tube 2 is not only cut by the cutting blade 42, but also squeezed between the flat cap 1 and the actuating cap 5, causing the fiber composite material to tear, bend, delaminate, break fibers, etc., thereby absorbing energy, and the upper thin-walled section of the cutter is crushed to undergo plastic deformation, thereby absorbing energy, and the friction generated by the fiber composite material and the upper thin-walled section of the cutter during movement can also absorb impact energy. The energy absorber has a relatively simple structure, can achieve both shearing and compression energy absorption in the actuating cap 5, is easy to assemble, and can be used as a basic energy absorption unit in more complex structural designs.

[0022] like Figures 1 to 4 As shown, in the preferred embodiment of the present application, a positioning ring 4 is further added to the above basic solution, and the positioning ring 4 is preferably made of metal material, such as Figures 1 to 4 As shown, there is an annulus d between the cylinder 41 and the actuating cap 5, the positioning ring 4 is fitted in the annulus d and is connected to the upper end of the actuating cap 5, the upper end of the cylinder 41, and the lower end of the limiting composite material pipe 2 through the shear pin, as shown in FIG. Figure 3 As shown in FIG. 1 , after the shear pin is broken, the positioning ring 4 falls into the bottom end of the annulus d. Figure 4 As shown, the annulus d is used to accommodate the upper material of the cylinder 41 after being crushed by the flattening cap 1. In order to avoid the upper material of the cylinder 41 from being crushed and affecting the compression of the fiber composite material tube 2, the annulus d is set. The annulus d can accommodate the upper material of the cylinder 41 after being crushed, but it will cause a gap between the cylinder 41 and the actuating cap 5, which will affect the structural stability at the moment of impact, and may cause the limiting composite material tube 2 and the cylinder 41 to slightly deviate to the side. Therefore, a positioning ring 4 is added to tightly connect the actuating cap 5 and the cylinder 41 to eliminate the gap at their ends. In this way, at the moment of impact, the limiting composite material tube 2 and the cylinder 41 can be prevented from deviating to the side. Moreover, after the shear pin is broken, the positioning ring 4 falls into the bottom of the annulus d, and the positioning ring 4 will not affect the subsequent energy absorption action.

[0023] like Figures 2 to 4 As shown, in this embodiment, preferably: the upper end of the thickened structure at the lower part of the cylinder 41 is a guide fillet c that can guide the strips 3 cut from the composite material tube 2 to deviate inwardly. The guide fillet c can allow the strips 3 to deviate inwardly before entering the guide curved surface b, thereby improving the efficiency and success rate of flipping the strips 3 upward.

[0024] like Figures 2 to 4 As shown, in this embodiment, preferably: the guide curved surface b is annular and surrounds the inner bottom surface of the actuating cap 5, and its cross section is semicircular, which can synchronously flip all the strips 3 from the periphery to the center.

[0025] like Figures 2 to 4 As shown, in this embodiment, preferably: the cutting blade 42 is in a grid shape, extending to the lower end of the cylinder 41, and can perform a second cutting on the strip 3 after being turned upward.

[0026] Under impact load: the shear pin is damaged and sheared off by the force, the connection constraint between the actuating cap 5, the positioning ring 4, the cylinder 41, and the limiting composite material pipe 2 is released, and the positioning ring 4 falls into the bottom end of the annulus d; then, the pressure cap 1 presses down the fiber composite material pipe 2, and the fiber composite material pipe 2 is cut into strips 3 by the cutting blade 42 during the downward movement. The strips 3 are first deflected inwardly under the action of the guide fillet c, and then turned upward under the action of the guide curved surface b, and pass through the cutting blade 42 again and cut again. In this process, the tearing, bending, fiber breakage and other factors of the fiber composite material pipe 2 are used to absorb energy; as the impact process proceeds, until the lower end face of the flat pressure cap 1 contacts the upper end face of the cylinder 41 and begins to cooperate with the insertion of the actuating cap 5, then, as the flat pressure cap 1 As the cylinder 41 moves downward, the thin-walled section of the cylinder 41 is crushed and deformed first, and the crushed and deformed material is squeezed into the annulus d, and the upper part of the cutting blade 42 is crushed and deformed under the action of the increased force; as the impact process proceeds, when the bottom end of the flat pressure cap 1 moves to a certain position, the strip 3 touches the inner surface of the flat pressure cap 1, and both ends of the strip 3 are subjected to force at the same time. At this time, the upper part of the cutter is gradually crushed and plastically deformed, which will further squeeze and destroy the strip 3. The debris generated by the strip 3 gradually fills the thickened section at the bottom of the cylinder 41 and is gradually compacted, further absorbing energy; when the thin-walled structure of the cutter is completely compressed and deformed, the stroke of the flat pressure cap 1 is limited by the thickened structure at the bottom of the cylinder 41. At this time, the debris generated by the destruction of the fiber composite material pipe 2 has also been compacted, and the energy absorption work is completed.

[0027] like Figures 2 to 4 As shown, in this embodiment, preferably: the lower end surface of the flat pressure cap 1 is provided with a slot, the outer diameter of which matches the inner diameter of the actuating cap 5, and the upper end of the fiber composite material tube 2 is inserted into the slot and fixedly connected by screws.

[0028] like Figures 2 to 4 As shown, in this embodiment, preferably: the lower end of the cylinder 41 is fixedly connected to the actuating cap 5 by screws.

[0029] In this embodiment, the flat pressure cap 1, the actuating cap 5 and the cutter are preferably made of metal materials, and the upper end of the flat pressure cap 1 and the lower end of the actuating cap 5 may be provided with ears for external installation.

[0030] The embodiments described above are part of the embodiments of the present application, rather than all of the embodiments. The detailed description of the embodiments of the present application is not intended to limit the scope of the present application for protection, but merely represents the selected embodiments of the present application. Based on the embodiments in the present application, all other embodiments obtained by ordinary technicians in this field without creative work are within the scope of protection of the present application.

Claims

1. A shear and compression combined energy absorber, characterized in that: It includes a flat pressure cap and an actuating cap located at the upper and lower ends, a cutter located in the actuating cap, and a fiber composite material tube for being cut and compacted; the cutter includes a cylinder with openings at both ends and a cutting blade axially arranged in the cylinder, the upper end of the fiber composite material tube is fixedly connected to the lower end of the flat pressure cap, and the lower end is inserted into the upper end of the cylinder and rests on the cutting blade, the upper end of the actuating cap, the upper end of the cylinder, and the lower end of the fiber composite material tube are connected together by a shear pin, and the lower end of the cylinder is fixedly connected to the actuating cap; the flat pressure cap is used to press down the fiber composite material tube after the impact load destroys the shear pin and is inserted into the actuating cap itself, a guiding curved surface is provided on the inner bottom surface of the actuating cap for guiding the strips cut from the composite material tube to flip upward, the cutting blade and the upper part of the cylinder are thin-walled structures that can be crushed by the flat pressure cap, and the lower part of the cylinder is a thickened structure that can limit the stroke of the flat pressure cap.

2. The shear and compression combined energy absorber according to claim 1, characterized in that: It also includes a positioning ring. There is an annulus between the cylinder and the actuating cap. The positioning ring fits in the annulus and is connected with the upper end of the actuating cap, the upper end of the cylinder, and the lower end of the limiting composite material pipe through the shear pin. After the shear pin is broken, the positioning ring falls into the bottom of the annulus. The annulus is used to accommodate the upper material of the cylinder crushed by the flat pressure cap. The positioning ring is made of metal material.

3. The shear and compression combined energy absorber according to claim 1, characterized in that: The upper end of the thickened structure at the lower part of the cylinder is a guide fillet which can guide the strips cut from the composite material tube to deviate inwards.

4. The shear and compression combined energy absorber according to claim 1, characterized in that: The guiding curved surface is annular and surrounds the inner bottom surface of the actuating cap, and its cross section is semicircular.

5. The shear and compression combined energy absorber according to claim 1, characterized in that: The cutting blade is in a grid shape and extends to the lower end of the cylinder.

6. The shear and compression combined energy absorber according to claim 1, characterized in that: The lower end surface of the flat pressure cap is provided with a slot, the outer diameter of which matches the inner diameter of the actuating cap, and the upper end of the fiber composite material tube is inserted into the slot and fixedly connected by screws.

7. The shear and compression combined energy absorber according to claim 1, characterized in that: The lower end of the cylinder is fixedly connected to the actuating cap by screws.

8. The shear and compression combined energy absorber according to claim 1, characterized in that: The flat pressure cap, the actuating cap and the cutter are made of metal material.

9. The shear and compression combined energy absorber according to claim 1, characterized in that: Ear pieces for external installation are arranged at the upper end of the flat pressure cap and the lower end of the actuating cap.

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