WO2017117862A1

WO2017117862A1 - Impact energy absorption mechanism

Info

Publication number: WO2017117862A1
Application number: PCT/CN2016/076031
Authority: WO
Inventors: 魏延鹏; 杨喆; 黄晨光
Original assignee: 中国科学院力学研究所
Priority date: 2016-01-04
Filing date: 2016-03-10
Publication date: 2017-07-13
Also published as: CN105599715B; CN105599715A

Abstract

Provided is an impact energy absorption. The impact energy absorption mechanism comprises an impacted part and an opposite part at a position opposite to the impacted part, wherein at least one martensite initial phase shape memory alloy beam (3) is supported between the impacted part and the opposite part, and a displacement restrictor (4) can be further arranged between the impacted part and the opposite part. The impact energy absorption mechanism not only avoids the occurrence of a secondary impact problem in an impact energy absorption process, but also can completely recover a deformation of the shape memory alloy beam through a temperature rise, so that the reuse of the mechanism is achieved.

Description

Impact energy absorbing mechanism

Technical field

The invention relates to the field of impact energy absorption, in particular to an impact energy absorbing mechanism that can be reused.

Background technique

For vehicles such as automobiles and high-speed trains, the impact phenomenon has always been an extremely important and unavoidable problem. In recent years, with the rapid increase in the number of cars and high-speed trains and the continuous increase in driving speed, the collision problem has become more and more prominent. The rapid increase of collision accidents will cause major personal injury and property damage, and crashworthiness has become a car and high-speed train. The primary consideration of structural design.

In the prior art, research and documentation of energy absorption using the properties of shape memory alloys have been made. A common use is to utilize the superelastic behavior of the initial phase of the shape memory alloy austenite. The use of stress-induced austenite-martensitic transformation has a large elastic deformation space and is capable of considerable energy absorption. However, this elastic energy absorption easily leads to the occurrence of secondary impact, which is often not conducive to the protection of personnel and equipment under impact.

Summary of the invention

One of the objects of the present invention is to provide an impact energy absorbing mechanism capable of preventing the occurrence of the aforementioned secondary impact phenomenon. The plan is as follows:

An impact energy absorbing mechanism includes an impact portion and a positionally opposite portion of the impact portion; at least one martensite initial phase shape memory alloy beam is supported between the impact portion and the opposite portion.

Preferably, the beam has an initial curvature such that bending deformation can occur upon compression.

Preferably, the beams are two or more, and are preferably evenly arranged between the impacted portion and the opposite portion.

Preferably, the shape memory alloy is a NiTi alloy.

The shape memory alloy of the martensite initial phase has a deformation space of Markov weight orientation when loaded. This deformation is characterized by plastic deformation, which can completely dissipate the impact kinetic energy by using plastic work, thereby avoiding secondary impact. problem. And this part of the deformation can be heated by heating the specimen to martensite - It can be recovered above the austenite phase transition temperature. That is to say, the plastic deformation of the martensitic initial phase shape memory alloy in the Martensitic bulk orientation stage is recoverable deformation, but after the Markov bulk orientation stage, it enters the martensite plastic deformation stage, and the plastic deformation at this stage cannot be heated. Restoration by simple measures is an irreversible deformation in the conventional sense. Therefore, in order to completely recover the deformation, the deformation amount of the shape memory alloy beam of the martensite initial phase needs to be controlled to a certain extent.

Based on this, another object of the present invention is to provide an impact energy absorbing mechanism that can be reused.

To achieve this, the aforementioned impact energy absorbing mechanism may further include a stopper disposed between the impacted portion and the opposite portion.

The limit displacement can be reasonably selected according to different design requirements. That is, the deformation of the beam is not deformed beyond the Markov body weight orientation.

Preferably, the stopper is mounted on the impact portion or the opposite portion.

Preferably, the stopper is provided with a slide rail, one end of which is inserted into the slide rail, and the other end is mounted on the impact portion or the opposite portion, opposite to the position where the stopper is installed.

In order to facilitate deformation recovery of the shape memory alloy beam, the impact energy absorbing mechanism may further include a heating device, and the heating device preferably includes a heat sink mounted on the stopper.

Through the above design, the impact energy absorbing mechanism of the present invention not only avoids the occurrence of the secondary impact problem, but also completely recovers the deformation of the shape memory alloy beam by the temperature rise, thereby realizing the repeated use of the mechanism.

DRAWINGS

1 is a schematic view showing an initial state of an impact energy absorbing mechanism according to an embodiment of the present invention;

2 is a schematic view showing the state of complete energy absorption of the impact energy absorbing mechanism of the embodiment of the present invention.

In the figure: 1 - impact plate, 2 - bottom plate, 3 - NiTi alloy beam, 4 - stopper, 5 - sliding member, 6 - heat sink.

Preferred embodiment of the invention

Embodiments of the present invention will be described in detail below with reference to the accompanying drawings. It should be noted that, not In the case of a conflict, the features of the embodiments and the embodiments of the present invention may be arbitrarily combined with each other.

The impact energy absorbing mechanism of the present invention includes an impact portion and a position opposite to the impact portion; at least one martensite initial phase shape memory alloy beam is supported between the impact portion and the opposite portion.

The shape memory alloy system discovered so far includes at least the following types: AuCd, AgCd, CuZn, CuZnAl, CuZnSn, CuZnSi, CuSn, CuZnGa, InTi, AuCuZn, NiAl, FePt, NiTi, TiNiPd, TiNb, UNb, and FeMnSi. The following examples are exemplified by a NiTi alloy.

1 and 2 illustrate an embodiment of the impact energy absorbing mechanism of the present invention. This embodiment is exemplified by the manner in which the impact load is applied from top to bottom. In this embodiment, the impacted portion and the opposite portion are both plate-shaped, that is, the impact plate 1 and the bottom plate 2, and the NiTi alloy beam supporting one or more martensite initial phases between the impact plate 1 and the bottom plate 2 3. The NiTi alloy beam 3 has a certain initial curvature to facilitate bending deformation when pressed. Moreover, in the case where there are a plurality of, the NiTi alloy beam 3 is preferably uniformly disposed between the impact plate 1 and the bottom plate 2 to ensure the balance of the force of the impact energy absorbing mechanism as a whole.

By using the impact energy absorbing mechanism of the above structure, the plastic deformation characteristic of the shape memory alloy of the martensite initial phase in the deformation stage of the Martensitic bulk orientation can completely dissipate the impact kinetic energy, thereby avoiding the occurrence of the secondary impact problem. . However, since the plastic deformation after entering the martensite plastic deformation stage from the Markov bulk orientation stage is an unrecoverable deformation in the conventional sense, the impact energy absorbing mechanism of the present embodiment is still subjected to the above-mentioned shock for the complete recoverability of the deformation. A stopper 4 is disposed between the impingement plate 1 and the bottom plate 2. As shown in FIGS. 1 and 2, the stopper 4 is mounted on the bottom plate 2. A stopper (not shown) is provided in the stopper 4. Referring to Fig. 1, a slider 5, for example, a columnar shape, is inserted into the slide, and the other end of the slider 5 is mounted on the impact plate 1.

According to the design principle of reusable and fully recoverable deformation, when the amount of motion of the mechanism reaches the stopper 4, the deformation in the martensitic initial phase shape memory alloy beam cannot exceed the deformation of the martensitic transformation, that is, the Markov transformation cannot occur. Body plastic deformation component. Therefore, different shape memory alloy beams can be designed according to different design requirements. According to the position and geometric size of the shape memory alloy beam, a reasonable limit displacement is set. The limit displacement refers to the action of the limiter. , the maximum relative displacement between the impact portion and the opposite portion.

Although in the present embodiment, the stopper 4 is mounted on the bottom plate 2, the slider 5 is mounted on the impact plate 1, but the mounting positions are also interchangeable, and the stopper 4 is mounted on the impact plate 1, which will The slider 5 is mounted on the bottom plate 2. Moreover, the slider 5 is optional, and the stopper 4 and/or the slider 5 can also adopt any other structure and shape capable of functioning as a limit.

In order to restore the deformation after the impact energy absorbing mechanism is completed after the impact is completed, the present invention also provides a heating device for the impact energy absorbing mechanism, which may be in an external, built-in or partially built-in form. In the embodiment shown in Figures 1 and 2, the reference numeral 6 identifies a heat sink, and the heat sink 6 is mounted on the stopper 4 for deformation after being used by the impact energy absorbing mechanism by means of an appropriate heat source. The post NiTi alloy beam 3 is heated to restore deformation. Although the form of the heat sink 6 is employed in the present embodiment, the heating mode of the NiTi alloy beam 3 is not limited thereto, and may be replaced with other suitable heating methods and heating structures in the prior art.

The force absorption and temperature recovery process of the impact energy absorbing mechanism of the present invention will be exemplarily described below with reference to FIGS. 1 and 2.

As shown in Fig. 1, the impact energy absorbing mechanism is in an initial state without being impacted. The impact load applies a force to the impact plate 1 from top to bottom in the direction of the arrow shown. During the impact energy absorption process, the impact plate 1 is moved downward, so that the NiTi alloy beam 3 is bent and deformed, and energy absorption is performed by bending plastic deformation, and the sliding member 5 fixedly connected to the impact plate 1 is along the stopper 4 The slide moves down. As shown in FIG. 2, when the deformation amount reaches the maximum value of the mechanism, the sliding member 5 fixedly connected to the impact plate 1 completely penetrates into the stopper 4, and the impact plate 1 is in contact with the stopper 4 at this time. The entire mechanism cannot continue to be deformed, and the NiTi alloy beam 3 has reached the maximum deformation of the design at this time. The impact energy absorbing mechanism completes its task at this moment and absorbs the energy in its design space. During the entire deformation process of the impact energy absorbing mechanism, the bending plastic deformation experienced by the NiTi alloy beam 3 is recoverable. After the impact is completed, the deformed NiTi beam is heated by the heat sink 6, and the impact energy absorbing mechanism is When the whole or NiTi alloy beam 3 is heated above the martensitic-austenite phase transition temperature of the NiTi material, the deformation can be completely restored, and the mechanism returns to the state of FIG.

The above is only the preferred embodiment of the present invention, and is not intended to limit the present invention, and various modifications and changes can be made to the present invention. Any modifications, equivalent substitutions, improvements, etc. made within the spirit and scope of the present invention are intended to be included within the scope of the present invention.

Industrial applicability

The impact energy absorbing mechanism provided by the present invention can be manufactured and used industrially to meet the requirements of industrial applicability.

Claims

An impact energy absorbing mechanism characterized by:

The portion including the impact portion and the portion opposite to the impact portion;

At least one martensitic initial phase shape memory alloy beam is supported between the impacted portion and the opposite portion.
The impact energy absorbing mechanism according to claim 1, wherein:

A limiter is also disposed between the impacted portion and the opposite portion.
The impact energy absorbing mechanism according to claim 2, wherein:

The stopper is mounted on the impact portion or the opposite portion.
The impact energy absorbing mechanism according to claim 3, wherein:

The limiter is provided with a slideway, one end of which is inserted into the slide rail, and the other end is mounted on the impacted portion or the opposite portion, opposite to the position where the stopper is installed.
The impact energy absorbing mechanism according to any one of claims 1 to 4, wherein:

The beam has an initial curvature.
The impact energy absorbing mechanism according to claim 1, wherein:

The beams are two or more.
The impact energy absorbing mechanism according to claim 6, wherein:

The beam is evenly arranged between the impacted portion and the opposing portion.
The impact energy absorbing mechanism according to claim 1, wherein:

The impact energy absorbing mechanism further includes a heating device.
The impact energy absorbing mechanism according to claim 8, wherein:

The heating device includes a heat sink mounted on the stopper.
The impact energy absorbing mechanism according to claim 1, wherein:

The shape memory alloy is a NiTi alloy.