CN114771456A - Seat belt buffer, energy absorption and energy dissipation device for occupant collision safety protection - Google Patents

Abstract

A seat belt buffering, energy absorbing and energy consuming device used for occupant collision safety protection. The continuous deformation of the compliant unit cell in the compliant metamaterial is used to buffer and absorb the instantaneous high pressure safely brought to the human body during collision. The compliant metamaterial is composed of several compliant unit cells with similar basic structures connected in series. Compliant cell bodies are divided into rigid rods and flexible sheets according to their deformation functions. The rigid rod includes an upper seat belt support shaft, two lower seat belt support shafts, two stable connecting rods, and two lower safety belt support shafts and two stable connecting rods 4 are assembled to form a quadrilateral structure. The flexible sheet includes four deformable sheets with the same structure, and the upper seat belt support shaft and the two lower seat belt support shafts are fixedly connected in pairs. The invention can effectively and uniformly buffer the impact force brought by the seat belt to the occupant when applied in the collision safety protection of the vehicle occupant; the metamaterial composed of multiple unit cells can cope with various collision accidents in different situations; the structure is simple, the performance is stable, and the cost is low.

Description

Seat belt buffer, energy absorption and energy dissipation device for occupant collision safety protection

technical field

The invention belongs to the technical field of automobile safety, and relates to a seat belt buffering, energy-absorbing and energy-consuming device for passenger collision safety protection.

Background technique

When a car crashes, the kinetic energy dissipation of the occupants mainly consists of two parts: one part is the energy dissipated by the occupants through the deformation of the restraint system and the deformation of the interior of the vehicle body, which is the so-called restraint energy of the occupants; the other part is the energy transmitted by the occupants to the vehicle through the restraint system. The energy consumed in the deformation process of the front part of the car body is the so-called crush energy (also called Ride-down energy). When a collision occurs, the distribution of the above two kinds of energy has an important impact on the injury of the occupants. It is generally believed that under the premise of ensuring other parts and other indicators, increasing the efficiency of Ride-down as much as possible can improve the occupant response. Seat belts are an important part of the restraint system. On the premise of satisfying the living space, reducing the stiffness of the restraint system dominated by seat belts as much as possible helps to improve the ride-down efficiency and reduce the occupant response, thereby reducing the risk of serious injury to the occupants.

When the rigidity of the seat belt system is relatively large, although it can provide better restraint protection, it is also more likely to cause damage to the human body. Especially in the case of high-speed collisions, the reaction force brought by the safety to the human body may cause serious injuries, including fractures. In order to reduce the instantaneous impact force exerted by the seat belt on the human body when the body collides, better collision energy absorption characteristics and better comfort and convenience have always been a main idea in the design and development of seat belts. At present, the existing devices that can improve the impact energy absorption characteristics of seat belts are mainly force-limiting seat belts and airbag seat belts. In addition, the energy absorption characteristics such as strength and elongation of the seat belt webbing are required.

There are some defects and deficiencies in the existing safety belt collision energy absorbing devices or methods, mainly including the following problems:

(1) The protective effect is limited. Take force-limiting seat belts, for example, which rely on torsion bars in the retractors to provide cushioning. When the tension of the seat belt reaches the set limit value, the torsion bar triggers the rotation effect, and the extra webbing released from the torsion bar can be used as a buffer. The use of the force limiter can improve the cushioning characteristics of the seat belt, so that the seat belt can exert a more uniform restraint force on the occupant and reduce the discomfort during use. But the problems are: 1) This type of seat belt is greatly affected by the preset force limit value, and can only play a protective role after the belt tension exceeds this value; 2) This type of seat belt does not have the function of energy dissipation , the absorbed energy will be released to act on the occupants again; 3) If the limit force value is too small or too large, the protection effect is not good.

(2) The structure is complex, the control method is cumbersome, and the cost is relatively high. The protection effect of airbag seat belts is better than that of ordinary seat belts and force-limiting seat belts, but the structural complexity and cost have increased a lot. Generally speaking, they contain many components such as gas generators, sensors, etc., and the control is also more complicated. . Limited by the cost, this technology is more common in mid-to-high-end models, and the degree of promotion is insufficient, and it is difficult for ordinary users to install it by themselves.

(3) The requirements for the seat belt webbing itself are mainly energy absorption indicators such as strength and elongation. These indicators have basically been standardized, and they are similar until there is no new progress in energy-absorbing webbing materials. It is worth noting that for a certain type of seat belt webbing, its stiffness cannot be dynamically adjusted according to the collision situation, resulting in unstable cushioning effect. In addition, most of the energy absorbed by the seat belt webbing is not dissipated, but is released to the occupant again, which is prone to cause multiple injuries.

To sum up, the ideal seat belt restraint system should have the following two functional characteristics: 1) buffer function, that is, it can evenly pressure the seat belt on the occupant's body, reduce the occupant's response, and mainly reduce the occupant's instantaneous acceleration; 2) Energy absorption and energy dissipation function, that is, it can absorb a part of the occupant kinetic energy caused by the collision, and dissipate all or part of it, so that it cannot be applied to the occupant again.

From the structural point of view, it is feasible to improve the energy absorption characteristics of the seat belt. Metamaterials have special properties that natural materials do not have, and these properties come from artificial special structures. The compliant multi-stable mechanism has unique advantages in buffering energy absorption, including simple structure, convenient manufacturing, and remarkable energy absorption effect. The design of seat belt buffer energy-absorbing structure provides new ideas.

SUMMARY OF THE INVENTION

The present application proposes a seat belt buffering, energy-absorbing and energy-consuming device for occupant collision safety protection. The device utilizes the continuous deformation of the compliant single cell in the compliant metamaterial to buffer and absorb the instantaneous high pressure brought to the human body by the safety belt during a collision, so as to ensure the effective restraint of the safety belt on the human body and at the same time reduce the pressure on the chest and abdomen of the human body. buffering effect. The invention can also absorb the energy generated by the collision and dissipate all or part of it, that is, the functions of energy absorption and energy consumption are achieved.

The stiffness characteristics and energy absorption threshold of the flexible single cell can be adjusted by changing the material, structure and other parameters of the flexible single cell. The energy absorption threshold here means that when the absorbed energy reaches a certain value, the energy will be dissipated and the structure loses the ability to continue absorbing energy. Further, a metamaterial can be formed by assembling flexible unit cells with different parameters in a certain order, and its overall structure covers multiple stiffness characteristics and energy absorption thresholds, so that it can cope with various degrees of collision. The invention can be installed on the ordinary automobile safety belt according to the requirements, and has the characteristics of modularization, simple structure, convenient disassembly and assembly, high reliability, stable performance and low cost.

In order to realize the above invention, the technical scheme adopted in this application is as follows:

A seat belt buffering, energy absorbing and energy dissipation device for providing protection in a occupant collision scenario, the seat belt buffering, energy absorbing and energy dissipation device utilizes the continuous deformation of a compliant unit cell in a compliant metamaterial to be safe in a collision The instantaneous high pressure brought to the human body is buffered and absorbed. The flexible metamaterial is formed by connecting several flexible single cells with similar basic structures in series in a certain order.

The compliant cell body can be divided into two parts: rigid rod and flexible sheet 3 according to the deformation function. The rigid rod includes an upper seat belt support shaft 1 and two lower seat belt support shafts 2 with the same structure, which are parallel to each other and arranged in a "pin" shape, that is, the upper seat belt support shaft 1 is located at the two sides. The middle and upper part of the plane where the lower seat belt support shaft 2 is located. The rigid rod also includes two stable connecting rods 4 with the same structure, and two ends of each stable connecting rod 4 are provided with through holes for connecting the ends of the lower seat belt support shafts 2, and the two lower seat belt support shafts 2. After being assembled with the two stable connecting rods 4, a parallelogram structure is formed. The flexible sheet 3 includes four deformable sheets with the same structure, which are respectively fixed on both ends of the upper seat belt support shaft 1 in two groups, and the other ends of the four flexible sheets 3 are fixed on the lower seat belt support shaft 2, that is, A pair of four flexible sheets 3 connect the upper seat belt support shaft 1 and the two lower seat belt support shafts 2 respectively, so that the two flexible sheets 3 in the same plane are connected to the upper seat belt support shafts 1 and 2. A lower seat belt support shaft 2 forms a quadrangle. In addition, from the perspective of the end of the rigid rod, the upper seat belt support shaft 1 , the lower seat belt support shaft 2 , the flexible sheet 3 and the stabilizing connecting rod 4 form a triangular shape.

Further, the flexible sheet 3 can be straight, folded or curved, that is, the flexible sheet 3 can be an angled curved sheet as a thin sheet, which can be abstracted as straight, folded or curved from the side.

Further, in each compliant unit cell, the number of the flexible sheets 3 may be an even number greater than four, and are still symmetrically arranged on both sides of the upper seat belt support shaft 1 according to the above logic. For example, on the basis of the above four flexible sheets, one flexible sheet can be added in parallel along the normal direction of the original flexible sheet to form an eight flexible sheet structure.

Further, the width and length of the flexible sheet 3 are much larger than its thickness, and the difference is generally more than 10 times.

Further, the connection relationship between the upper seat belt support shaft 1 , the lower seat belt support shaft 2 and the flexible sheet 3 of the compliant cell body can be realized by integral manufacturing, or can be realized by separately manufacturing and then assembling. The stabilizer connecting rod 4 is manufactured separately and then assembled with the upper and lower seat belt support shafts 1 and 2 and the flexible sheet 3 which are manufactured or assembled in one body.

Further, no matter what changes occur to the shapes of the above-mentioned components, it is conceivable to realize the above-mentioned deformation process by ensuring that the force relationship between these components is similar to each other.

Further, the angle θ between the flexible sheet 3 and the stable connecting rod 4 and the geometric parameters (length, width and thickness) of the flexible sheet 3 can be used as control parameters for controlling the buffering, energy absorption and energy dissipation effects of the compliant cell body, that is, Control parameters for stiffness properties and energy absorption thresholds. The adjustment of these parameters is done before manufacture and cannot be adjusted after manufacture. In addition, the material of the flexible sheet is also one of the parameters to adjust its stiffness characteristics and energy absorption threshold.

Further, each compliant unit cell has certain deformation energy absorption characteristics (ie stiffness characteristics and energy absorption threshold) after setting the control parameters, which can be applied independently, but this deformation energy absorption characteristic is single and immutable. In order to enhance the effects of buffering, energy absorption and energy consumption of the present invention, so that it has wider stiffness characteristics and energy absorption thresholds, compliant cells with different stiffness characteristics and energy absorption thresholds can be connected in series to form a multi- A metamaterial with flexible single cells to cope with different degrees of collision. One of the characteristics of the metamaterial is that its deformation energy absorption characteristics are not only affected by the properties of each compliant unit cell, but also change due to the different arrangement of each compliant unit cell. By setting the parameters of each compliant unit separately and arranging them in series in a certain order, a reasonable arrangement of the stiffness properties and energy absorption thresholds of metamaterials can be achieved. The serial connection is implemented as follows: a lower seat belt support shaft 2 is shared between two adjacent compliant cells, and the stable connecting rods 4 of the two compliant cells are both connected to the shared lower seat belt support shaft 2 . Alternatively, other connection solutions or integrated manufacturing can be adopted to achieve this effect.

When the compliant cell of the present invention is installed and used, the seat belt needs to be in contact with the surfaces of the upper seat belt support shaft 1 and the lower seat belt support shaft 2 at the same time. The contact sequence of the belt support shaft 2 passes through these rigid rod surfaces in sequence. During this process, the seat belt continuously passes through the quadrangular area formed by the two flexible sheets and the upper and lower seat belt support shafts respectively. When the seat belt is tightened by force, the upper seat belt support shaft 1 will follow the seat belt to move toward the plane of the two lower seat belt support shafts 2 after being pressed by the seat belt, and the four flexible sheets 3 will be deformed accordingly. The force on the seat belt can be buffered, absorbed and consumed by the deformation of the flexible sheet 3 . It should be noted that, when the devices described in this application are connected, when the flexible sheet deforms, it will drive the lower seat belt support shaft 2 connected to it to rotate around the through hole where the latter is in contact with the stable connecting rod 4 .

When in use, the present invention, as an accessory device of the seat belt, needs the correct installation of the seat belt to function. Specifically: when there is only one compliant unit cell, the seat belt continuously passes through the upper and lower seat belt support shafts 1 and 2 and the flexible The two quadrilaterals formed by the sheets remain in contact with these rigid bar surfaces after installation. When there are multiple compliant cells to form the metamaterial, the installation of the seat belt is similar to the above process, except that the contact sequence of the lower seat belt support shaft 2 - the upper seat belt support shaft 1 - the lower seat belt support shaft 2 should be continuously passed through all the The inside of the quadrilateral formed by the upper and lower seat belt support shafts and the flexible sheet can keep the seat belt in contact with all rigid rod surfaces after installation. In general, the good installed feature of the present invention is that when the seat belt is stressed and tensioned, the compliant unit cell can maintain a good support for the seat belt so as to transmit the force. When the car collides and the human body rushes forward to cause instantaneous high tension on the seat belt body, the seat belt is tightened and the upper seat belt support shaft is stressed, and the flexible sheet 3 is driven and deformed accordingly. The deformation process of the flexible sheet 3 is the process of buffering and energy absorption. Since the deformation process is irreversible, the absorbed energy is dissipated, thereby avoiding secondary damage to the occupants.

The beneficial effects of the present invention are:

(1) In the present invention, the application of the compliant single cell in the collision safety protection of the vehicle occupants can effectively uniform the impact force brought by the seat belt to the occupants and absorb the kinetic energy of the occupants. And the absorbed energy will be dissipated so that it cannot act on the occupants again.

(2) The collision accidents that a single compliant unit cell can deal with are limited, and after multiple compliant unit cells form a metamaterial, it can achieve a wider margin of stiffness characteristics and energy absorption thresholds, so that it can cope with a variety of collision accidents in different situations, Better protection for occupants.

(3) In addition, the present invention can be installed on ordinary automobile seat belts according to requirements, and has the characteristics of modularization, simple structure, convenient disassembly and assembly, high reliability, stable performance, and low cost.

Description of drawings

FIG. 1 is a schematic diagram of the structure of a compliant unit cell in the buffering, energy-absorbing and energy-consuming device for an automobile seat belt proposed in the present application.

FIG. 2 is a schematic diagram of the cooperation and installation of a certain unit cell of the vehicle seat belt buffering, energy absorbing and energy consuming device proposed in the present application and the seat belt.

FIG. 3 is a schematic diagram of the working deformation of the core unit cell of the automobile seat belt buffering, energy absorbing and energy consuming device proposed in the present application.

FIG. 4 is a specific embodiment of the compliant cell body using eight bending flexible sheets in the buffering, energy-absorbing and energy-consuming device of the automobile seat belt proposed in the present application.

FIG. 5 is a schematic diagram of the structure and composition of the metamaterial in the cushioning, energy-absorbing and energy-consuming device of the automobile seat belt proposed in the present application.

FIG. 6 is an example of a compliant metamaterial formed by a tri-compliant unit cell in the cushioning, energy-absorbing and energy-consuming device for an automobile seat belt proposed in the present application.

FIG. 7 is a schematic diagram of a specific installation of the vehicle seat belt buffering, energy-absorbing and energy-consuming device proposed in the present application.

In the figure, 1 upper seat belt support shaft, 2 lower seat belt support shaft, 3 flexible sheet, 4 stable connecting rod, 5 seat belt, 51 seat belt D ring, 52 seat belt buckle, 53 seat belt anchor point, 6 buffer Energy absorbing device.

Detailed ways

The specific embodiments of the present invention will be described in detail below with reference to the technical solutions and the accompanying drawings.

A seat belt buffering, energy-absorbing and energy-consuming device for providing protection in a collision scenario of an occupant, the seat belt buffering, energy-absorbing and energy-consuming device utilizes the continuous deformation of a compliant metamaterial to safely bring the human body during a collision. Instantaneous high pressure for buffering and absorption. The flexible metamaterial is formed by connecting several flexible single cells with similar basic structures in series in a certain order. The compliant cell body can be divided into two parts: rigid rod and flexible sheet 3 according to the deformation function. The rigid rod includes an upper seat belt support shaft 1 and two lower seat belt support shafts 2 with the same structure, which are parallel to each other and arranged in a "pin" shape, that is, the upper seat belt support shaft 1 is located at the two sides. The middle and upper part of the lower seat belt support shaft 2. The rigid rod also includes two stable connecting rods 4 with the same structure, and two ends of each stable connecting rod 4 are provided with through holes for connecting the ends of the lower seat belt support shafts 2, and the two lower seat belt support shafts 2. A parallelogram structure is formed with the two stabilizing connecting rods 4 . The stable connecting rods 4 are respectively located at both ends of the lower seat belt support shaft 2 and connect the lower seat belt support shaft 2, that is, the two stable connecting rods 4 and the two lower seat belt support shafts also form a parallelogram. The flexible sheet 3 includes four deformable sheets with the same structure, which are respectively fixed on both ends of the upper seat belt support shaft 1 in two groups, and the other ends of the four flexible sheets 3 are fixed on the lower seat belt support shaft 2, that is, The upper seat belt support shaft 1 is fixedly connected with the two lower seat belt support shafts 2 in pairs of four flexible sheets 3, so that the two flexible sheets 3 in the same plane are connected with the upper seat belt support shaft 1. and a lower seat belt support shaft 2 to form a quadrilateral. In addition, from the perspective of the end of the rigid rod, the upper seat belt support shaft 1 , the lower seat belt support shaft 2 , the flexible sheet 3 and the stabilizing connecting rod 4 form a triangular shape.

FIG. 1 is a schematic diagram of the compliant unit cell structure of the vehicle seat belt buffering, energy absorbing and energy dissipation device proposed in the present application. The performance of the compliant unit cell, that is, the effects of buffering, energy absorption and energy dissipation, is guaranteed by its material and structure parameters. For the convenience of description, the compliant structures mentioned in this application are all made of the same material by default. However, it should be noted that the rational arrangement of materials with different compliant structures and the regulation of other structural parameters to realize the adjustment of the overall performance is also envisaged. In terms of the structure of the flexible single cell, the deformation threshold force can be adjusted by changing the angle parameter θ between the flexible sheet 3 and the stable connecting rod 4, so as to obtain the expected deformation performance.

FIG. 2 is a schematic diagram of the cooperation and installation of the compliant unit cell and the seat belt of the vehicle seat belt buffering, energy-absorbing and energy-consuming device proposed in the present application. When the compliant cell is installed and used, the seat belt is in contact with the surfaces of the upper seat belt support shaft 1 and the lower seat belt support shaft 2 at the same time, that is, according to the lower seat belt support shaft 2 - upper seat belt support shaft 1 - lower seat belt support shaft The contact sequence of 2 passes sequentially through these rigid rod surfaces. When the seat belt is tightened by force, the upper seat belt support shaft 1 will have a tendency to move with the seat belt after being pressed by the seat belt, and the four flexible sheets 3 will be deformed accordingly. The force on the seat belt can be buffered, absorbed and consumed by the deformation of the flexible sheet 3 . It should be noted that the upper seat belt support shaft 1 moves in the direction of the lower seat belt support shaft 2 during this process, and when the flexible sheet is deformed, it will drive the lower seat belt support shaft 2 connected to it, and the latter is the same as the stable connecting rod 4. The contact vias are rotated around the center.

FIG. 3 is a schematic diagram showing the composition of the metamaterial morphological structure of the automobile seat belt buffering, energy absorbing and energy dissipation device proposed in the present application, which represents a specific embodiment. Specifically, the metamaterial is composed of several compliant cells with different parameters connected in series in the order shown in the figure, and two adjacent compliant cells share a lower seat belt support shaft 2 . The upper and lower seat belt support shafts 1 and 2 and the flexible sheet 3 of each compliant unit cell are manufactured integrally, while the stabilizing connecting rod 4 is manufactured separately and participates in assembly through its end through holes. After the compliant cells are fabricated, the parameters have been determined and cannot be modified, but the metamaterial can adjust the overall buffering, energy absorption and energy consumption effects by rationally arranging the number of compliant cells with different parameters and the order of connection between them. The engagement sequence is the sequence of who the compliant monomers with different parameters adjoin or share the lower seat belt support shaft.

FIG. 4 is an example of adding a flexible sheet to a compliant unit cell in the cushioning, energy-absorbing and energy-consuming device for an automobile seat belt proposed in the present application, and all the flexible sheets are bent sheets. In this embodiment, the upper and lower seat belt support shafts 1 and 2 are still symmetrically arranged with four pairs of eight flexible sheets 3 at both ends according to the aforementioned logic. It can be understood that the aforementioned four flexible sheet structures are along the normal direction of the flexible sheets 3 After adding four flexible sheets 3 in parallel, other connecting structures are obtained by making corresponding changes. In this way, the two flexible sheets 3 connected to the end of a certain lower seat belt support shaft 2 at the same time are parallel, and from the perspective of a certain end of the seat belt support shaft, there are four flexible sheets in two "eight" shapes. ” in parallel with the upper and lower seat belt support shafts 1 and 2.

FIG. 5 is a schematic diagram of the working deformation of the basic compliant unit cell in the cushioning, energy-absorbing and energy-consuming device of the automobile seat belt proposed in the present application. The device mainly relies on the deformation of the flexible sheet 3 to buffer, absorb and dissipate energy. When the seat belt is tightened by force, the upper seat belt support shaft 1 will follow the seat belt to move toward the plane of the two lower seat belt support shafts after being pressed by the seat belt, and the four flexible sheets 3 will be deformed accordingly. The force on the seat belt can be buffered, absorbed and consumed by the deformation of the flexible sheet 3 . As a specific embodiment, when the flexible sheet 3 is deformed, it will drive the lower seat belt support shaft 2 connected to it to rotate centered on the through hole where the latter is in contact with the stable connecting rod 4 .

The above-mentioned represent the basic flexible cell deformation energy absorption process. In metamaterials composed of several compliant cells, each compliant cell exhibits different stiffness properties and energy absorption thresholds due to different parameters. Those with a low threshold are easy to deform and can be used as a buffer, whereas those with a low threshold are not easily deformed and can absorb more energy relatively. In this way, the whole system can achieve a good response to different collision situations.

Specifically, FIG. 6 represents an embodiment in which three compliant cells are connected in series to form a compliant metamaterial by sharing a lower seat belt support shaft. The detailed settings are as follows; 1) Set all unit cell materials to use 6061 aluminum; 2) Set all lower seat belt support shafts to be cylindrical rigid rods with a diameter of 20mm and a length of 110mm, and they are spaced 100mm from each other 3) Set the upper seat belt support shaft as a cylindrical rigid rod with a diameter of 20mm and a length of 90mm; 4) Set the flexible sheets to be thin sheets with a thickness of 1.5 mm and a width of 20 mm; 5) Set the flexible sheets to be the same as the upper and lower safety bars The connection with the support shaft is completed by integrated manufacturing; 6) Set the stable connecting rod to be a rigid rod with a length of 120mm, a width of 20mm and a thickness of 5mm, and its two ends have through holes with an inner diameter of 20mm, which are used to connect with the two lower safety rods. The ends with support shafts are connected; 7) Set the included angles θ ₁ , θ ₂ and θ ₃ between the stable connecting rods and the flexible sheets in the compliant cells 1, 2, and 3 to be 30°, 50°, and 40°, respectively. FIG. 7 shows a specific installation method of the compliant metamaterial and the safety belt.

The above-mentioned embodiments only represent the embodiments of the present invention, but should not be construed as a limitation on the scope of the present invention. It should be pointed out that for those skilled in the art, without departing from the concept of the present invention, Several modifications and improvements can also be made, which all belong to the protection scope of the present invention.

Claims (7)

1. A safety belt buffering, energy-absorbing and energy-consuming device for passenger collision safety protection is characterized in that the safety belt buffering, energy-absorbing and energy-consuming device utilizes continuous deformation of a flexible single cell body in a flexible metamaterial to buffer and absorb instantaneous high pressure of a safety belt to a human body during collision; the compliant metamaterial is formed by serially connecting a plurality of compliant single cells with similar basic structures according to a certain sequence;

the flexible cell body can be divided into a rigid rod and a flexible sheet (3) according to the deformation function; the rigid rod comprises an upper safety belt support shaft (1) and two lower safety belt support shafts (2) with the same structure, wherein every two safety belt support shafts are parallel to each other and arranged in a shape like a Chinese character 'pin'; the rigid rod further comprises two stabilizing connecting rods (4) with the same structure, through holes for connecting the end parts of the lower safety belt supporting shafts (2) are formed in the two ends of each stabilizing connecting rod (4), and the two lower safety belt supporting shafts (2) and the two stabilizing connecting rods (4) are assembled to form a parallelogram structure; the flexible sheets (3) comprise four deformable sheets with the same structure, the upper safety belt supporting shafts (1) are fixedly connected with the two lower safety belt supporting shafts (2) in a pairwise mode, and the two flexible sheets (3) in the same plane, the upper safety belt supporting shafts (1) and the lower safety belt supporting shafts (2) form a quadrangle; from the end view of the rigid rod, a triangle is formed among the upper safety belt supporting shaft (1), the lower safety belt supporting shaft (2), the flexible sheet (3) and the stabilizing connecting rod (4);

when the flexible cell body is installed and used, the safety belt needs to be simultaneously contacted with the front surfaces of the upper safety belt supporting shaft (1) and the lower safety belt supporting shaft (2), and the safety belt continuously penetrates through quadrilateral areas respectively formed by the two flexible sheets and the upper and lower safety belt supporting shafts; when the safety belt is pulled tightly by force, the upper safety belt supporting shaft (1) moves towards the plane where the two lower safety belt supporting shafts (2) are located along with the safety belt after being pressed by the safety belt, and the four flexible sheets (3) deform along with the movement; the force borne by the safety belt is buffered, absorbed and consumed through the deformation of the flexible sheet (3); when the flexible sheet (3) deforms, the lower safety belt supporting shaft (2) connected with the flexible sheet is driven to rotate by taking the through hole in contact with the stable connecting rod (4) as a center.

2. The seatbelt buffering, energy absorbing and energy dissipating device for passenger crash safety protection as claimed in claim 1, wherein the compliant cells with different stiffness characteristics and energy absorption thresholds can be connected in series to form a metamaterial comprising a plurality of compliant cells to cope with different levels of crash conditions.

3. The seatbelt buffering, energy absorbing and energy dissipating apparatus for passenger crash safety protection according to claim 1, wherein said series connection is implemented by: a lower safety belt supporting shaft (2) is shared between two adjacent flexible single cells, and the stable connecting rods (4) of the two flexible single cells are connected with the shared lower safety belt supporting shaft (2); or be made integrally.

4. A belt buffering, energy absorbing and dissipating device for passenger crash safety protection according to claim 1, characterized in that the width and length of the flexible sheet (3) are greater than its thickness.

5. The seatbelt buffering, energy absorbing and energy dissipating device for passenger collision safety protection as claimed in claim 1, wherein the upper seatbelt supporting shaft (1), the lower seatbelt supporting shaft (2) and the flexible sheet (3) in the compliant cell body can be manufactured integrally or assembled separately.

6. The seatbelt buffering, energy absorbing and energy dissipating device for passenger crash safety protection as claimed in claim 1, wherein the included angle θ between the flexible sheet (3) and the stabilizing connecting rod (4), the material of the flexible sheet and the geometric parameters of the flexible sheet (3) are used as the controlling parameters for controlling the buffering, energy absorbing and energy dissipating effects of the compliant cell body, i.e. the stiffness characteristic and the energy absorbing threshold.

7. The seatbelt buffering, energy absorbing and energy dissipating device for passenger crash safety protection as claimed in claim 1, wherein the number of the flexible sheets (3) in each of the compliant cells is an even number greater than four, and is symmetrically disposed on both sides of the upper seatbelt supporting shaft (1).

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