A car bumper crossbeam assembly structure, a car, and a collision energy absorption method.

Abstract

This invention discloses a car bumper beam assembly structure, a car, and a collision energy absorption method, including a lightweight bumper beam body, active telescopic energy-absorbing boxes, and connecting plates; a pair of active telescopic energy-absorbing boxes are symmetrically fixed at their upper ends to the lower ends of the left and right sides of the lightweight bumper beam body; each active telescopic energy-absorbing box is fixedly connected to a connecting plate at its lower end; the pair of active telescopic energy-absorbing boxes can drive the lightweight bumper beam body to extend and retract synchronously relative to the connecting plates; the bumper beam body of this invention uses lightweight materials, and the energy-absorbing boxes also integrate active telescopic functions, which can adjust the distance between the bumper and the anti-collision beam in the event of a low-speed collision, and has the advantages of simple overall structure, high strength, pedestrian protection, and reduced processing and maintenance costs.

Description

Technical Field

[0001] This invention relates to the field of automotive parts technology, and in particular to an automotive bumper beam assembly structure, an automotive vehicle, and a collision energy absorption method. Background Technology

[0002] Modern cars feature a bumper beam assembly at the front of the engine compartment as a passive safety protection component. The components within the bumper beam assembly are all made of stamped steel sheets, which are then combined to form the bumper beam assembly. To ensure the bumper beam itself has high strength and rigidity, it is typically designed with high-strength steel sheets, hot-formed steel sheets, or aluminum alloy materials, requiring a relatively thick material to meet performance requirements. While protecting the safety of occupants, it can also cause injury to pedestrians. The distance between the bumper and the anti-collision beam is determined according to the vehicle's safety design and crash test standards to ensure maximum protection of passengers and minimize vehicle damage in the event of a collision. Pedestrians are a vulnerable group among road users, and collisions between pedestrians and vehicles are characterized by high fatality rates, high serious injury rates, and high disability rates. While high-strength anti-collision beams facilitate the transfer and absorption of collision energy, they are also a primary cause of injury to pedestrians. Summary of the Invention

[0003] To address the aforementioned issues, this invention provides an automotive bumper beam assembly structure. The main body of the bumper beam is made of lightweight materials, and the energy-absorbing box integrates an active telescopic function, which can adjust the distance between the bumper and the anti-collision beam during low-speed collisions. It has advantages such as simple overall structure, high strength, pedestrian protection, and reduced processing and maintenance costs.

[0004] This invention proposes a car bumper crossbeam assembly structure, including a lightweight bumper crossbeam body, an active telescopic energy-absorbing box, and a connecting plate;

[0005] A pair of active telescopic energy-absorbing boxes are symmetrically fixed at the upper end to the lower end of the left and right sides of the lightweight bumper crossbeam body; each active telescopic energy-absorbing box is fixedly connected to a connecting plate at the lower end; the active telescopic energy-absorbing box adjusts the amount of oil in the cylinder to meet the needs of different types of collisions; the active telescopic energy-absorbing box also further absorbs collision energy through its own cross-section and outer surface structure.

[0006] A pair of active telescopic energy-absorbing boxes can synchronously extend and retract the lightweight bumper crossbeam relative to the connecting plate. The lightweight bumper crossbeam protects the assembly behind the crossbeam and the passenger space in the event of a collision, especially a frontal collision. The active telescopic energy-absorbing boxes are connected to the crossbeam as energy-absorbing components. The rear end of the connecting plate can be screwed and fixed to the vehicle's main crossbeam. Before crushing and deforming, the active telescopic energy-absorbing boxes can automatically adjust their displacement, causing the lightweight bumper crossbeam to move synchronously to meet the needs of different types of collisions, thereby reducing pedestrian injuries in low-speed collisions. In high-speed collisions, the active telescopic energy-absorbing boxes can more effectively disperse the impact force, reducing damage to the vehicle structure and thus lowering maintenance costs.

[0007] Each active telescopic energy-absorbing box includes a cylinder body and a piston rod. The piston rod is slidably sleeved within the cylinder body, and the free end of the piston rod is detachably fixed to the end of the aligned lightweight bumper beam body via a U-shaped connecting arm fixed to the free end. The piston rod divides the cylinder body into a rod chamber and a rodless chamber, and the upper side wall of the rod chamber and the lower side wall of the rodless chamber are respectively provided with oil inlet / outlet a and oil inlet / outlet b. Oil inlet / outlet a and oil inlet / outlet b can be connected to the oil reservoir with an oil pump on the vehicle through pipelines, so that oil can be injected or extracted into the rod chamber and rodless chamber through pipelines according to the collision state during low-speed or high-speed driving, so as to realize the bidirectional movement of the piston rod. This allows the lightweight bumper beam body to reduce the injury to pedestrians in low-speed collisions or to complete the collision energy absorption of the lightweight bumper beam body and the energy-absorbing box in high-speed collisions, which can more effectively disperse the impact force, reduce damage to the vehicle structure, and thus reduce maintenance costs.

[0008] Each active telescopic energy-absorbing box cylinder has a cross-section with an outer square and inner circle structure to ensure that the energy-absorbing box maintains a certain strength against crushing deformation.

[0009] Several crushing guide ribs are symmetrically and evenly arranged on the four edges of the outer surface of each active telescopic energy-absorbing cylinder. When a car collides with another vehicle at high speed, the collision sensor sends a signal to the central controller within a very short time after the collision. The front bumper beam and the energy-absorbing box structure are crushed, the end of the energy-absorbing box piston rod moves backward, and when the oil space is compressed to the limit but still cannot meet the energy absorption space, the central controller issues a command to open the oil inlet and outlet a to discharge the excess oil. The energy-absorbing box structure itself is naturally crushed under the guidance of the crushing guide ribs to achieve the absorption of more collision energy.

[0010] The lightweight bumper beam has a hollow tubular cavity structure; the main body of the lightweight bumper beam is made of aluminum alloy or other high-strength lightweight materials, which helps to reduce the weight of the parts.

[0011] The lightweight bumper beam body is a hollow multi-tubular cavity structure, and its cross-section is in the shape of "日" (Chinese character for sun), "目" (Chinese character for eye), or "田" (Chinese character for field) to further enhance the compressive collapse deformation strength of the front and rear end walls of the lightweight bumper beam body in the X direction (the vehicle body length direction).

[0012] A vehicle includes a front main beam and also includes the above-mentioned vehicle bumper beam assembly structure. The vehicle bumper beam assembly structure is fixed to the front end face of the front main beam. The connection forms between the active telescopic energy-absorbing box, the connecting plate, and the front main beam are welding, chemical bonding, or screwing connection.

[0013] A vehicle further includes a pressure tube type pedestrian collision detection sensor, an oil storage tank with an oil pump, a vehicle computer, and a collision sensor. The pressure tube type pedestrian collision detection sensor is arranged through the front end face of the transverse dimension of the lightweight bumper beam body. The pressure tube type pedestrian collision detection sensor and the collision sensor are respectively electrically connected to the vehicle computer. The vehicle computer is electrically connected to the oil pump of the oil storage tank. The collision sensor is arranged at the front part of the vehicle body sheet metal. The oil pump on the oil storage tank is respectively connected to the oil inlet and outlet a and the oil inlet and outlet b through pipelines. Most of the collision sensors adopt an inertial mechanical switch structure, which is equivalent to a control switch, and its working state depends on the magnitude of the acceleration during vehicle collision.

[0014] A collision energy absorption method includes an energy absorption method for the bumper beam assembly structure in the pedestrian collision protection mode:

[0015] When the vehicle is in the startup state and maintains the speed limit on urban roads, a certain volume of oil is injected into the rodless cavity of the active telescopic energy-absorbing box. At the same time, a rodless cavity reserved oil-free space V is left, and the oil inlet and outlet b is closed.

[0016] When the pressure tube type pedestrian collision detection sensor identifies a collision with a pedestrian, the active scheme sensing time ST, the vehicle computer controls the oil pump to quickly inject oil from the oil inlet and outlet a. The left and right piston rods drive the lightweight bumper beam body to move backward a certain displacement L1. The mechanism execution time DT provides more collision buffer zones for pedestrians within the collision time TTC and the contact beam time HIT, reducing the injury to the pedestrian's leg area during the collision.

[0017] The active scheme sensing time ST + the mechanism execution time DT < the collision time TTC + the contact beam time HIT;

[0018] After the collision ends, the vehicle computer can command the oil pump to inject a certain volume of oil into the rodless cavity from the oil inlet and outlet b again. At the same time, the vehicle computer commands the oil pump to evacuate the oil injected into the rodless cavity from the oil inlet and outlet a, so that the lightweight bumper beam body returns to its initial position.

[0019] A collision energy absorption method includes an energy absorption method for the bumper beam assembly structure in the vehicle and occupant space protection mode:

[0020] When the vehicle speed exceeds the speed limit of urban roads, the pedestrian protection sensor will be disabled. When the vehicle collides with other objects at low speed, the collision sensor detects the intensity signal of the collision and the inertial force under the maximum deceleration when the vehicle collides. The signal is then input into the vehicle computer. The vehicle computer determines the position of the active telescopic energy absorption box based on the signal from the collision sensor and drives the oil pump to inject more oil into the inlet and outlet ports b to fill the V space and then close it. The collision impact force is transmitted from the lightweight bumper crossbeam to the piston rod of the active telescopic energy absorption box, which compresses the oil space to generate resistance and achieve buffering and energy absorption, reducing damage to the vehicle's front main crossbeam and longitudinal beams and other structural components, as well as reducing the injury to the occupants in the passenger compartment.

[0021] After a collision, the lightweight bumper beam will be crushed and deformed, but the active telescopic energy-absorbing box will not be damaged. The lightweight bumper beam can be replaced by removing the bolts between the active telescopic energy-absorbing box and the lightweight bumper beam, thus reducing maintenance costs.

[0022] Alternatively, when the vehicle's speed exceeds the speed limit on urban roads, the pedestrian protection sensor will be disabled. When a high-speed collision occurs between the vehicle and another vehicle, the collision sensor sends a signal to the vehicle's computer within a very short time after the collision. The lightweight bumper beam and the active telescopic energy-absorbing box structure crush, and the piston rod end of the active telescopic energy-absorbing box moves backward. Even if the oil space is compressed to its limit, it is still insufficient to absorb energy. The vehicle's computer issues a command to control the oil pump to remove excess oil from the inlet and outlet ports b. The active telescopic energy-absorbing box naturally crushes under the guidance of several crushing guide ribs to absorb more collision energy. At the same time, the vehicle's computer determines, based on the collision sensor signal, whether to detonate the inflatable element to inflate the airbag and other passive safety measures to reduce injury to the occupants of the passenger compartment.

[0023] Beneficial effects

[0024] The main body of the bumper beam of this invention is made of lightweight material, and the energy-absorbing box also integrates an active telescopic function, which can adjust the distance between the bumper and the anti-collision beam in the event of a low-speed collision. It has the advantages of simple overall structure, high strength, protection of pedestrians, and saving processing and maintenance costs. Attached Figure Description

[0025] Figure 1 This is a schematic diagram of the overall structure of the present invention.

[0026] Figure 2 This is a partially enlarged structural schematic diagram of the present invention.

[0027] Figure 3 yes Figure 2 A schematic diagram of the AA cross-sectional structure.

[0028] Figure 4 yes Figure 2 A schematic diagram of the BB cross-sectional structure.

[0029] Figure 5 yes Figure 2 A schematic diagram of the CC cross-sectional structure.

[0030] Figure 6 yes Figure 2 A schematic diagram of the DD cross-sectional structure.

[0031] Figure 7 This is a schematic diagram of the working principle and structure of the present invention. Figure 1 .

[0032] Figure 8 This is a schematic diagram of the working principle and structure of the present invention. Figure 2 .

[0033] Figure 9 This is a schematic diagram of the working principle and structure of the present invention. Figure 3 .

[0034] In the picture:

[0035] 1. Lightweight bumper crossbeam main body;

[0036] 2. Active telescopic energy absorption box; 21. Hydraulic cylinder body; 211. Rod chamber; 2111. Oil inlet / outlet a; 212. Rodless chamber; 2121. Oil inlet / outlet b; 213. Crushing guide rib; 22. Piston rod; 23. U-shaped connecting arm;

[0037] 3. Connecting plate. Detailed Implementation

[0038] To make the technical problems solved by the present invention, the technical solutions adopted, and the technical effects achieved clearer, the technical solutions of the present invention will be further described below in conjunction with the accompanying drawings and specific embodiments. It should be understood that the specific embodiments described herein are merely for explaining the present invention and are not intended to limit the present invention. Furthermore, it should be noted that, for ease of description, only the parts related to the present invention are shown in the accompanying drawings, not all of them.

[0039] In the description of this invention, it should be noted that the terms "center," "upper," "lower," "left," "right," "vertical," "horizontal," "inner," and "outer," etc., indicate the orientation or positional relationship based on the orientation or positional relationship shown in the accompanying drawings. They are used only for the convenience of describing the invention and for simplifying the description, and do not indicate or imply that the device or element referred to must have a specific orientation, or be constructed and operated in a specific orientation. Therefore, they should not be construed as limitations on the invention. Furthermore, the terms "first" and "second" are used for descriptive purposes only and should not be construed as indicating or implying relative importance. The terms "first position" and "second position" refer to two different positions.

[0040] In the description of this invention, it should be noted that, unless otherwise explicitly specified and limited, the terms "installation," "connection," and "linking" should be interpreted broadly. For example, they can refer to fixed connections or detachable connections; mechanical connections or electrical connections; direct connections or indirect connections through an intermediate medium; and internal connections between two components. Those skilled in the art can understand the specific meaning of these terms in this invention based on the specific circumstances.

[0041] Example 1

[0042] See Figures 1-6 As shown, a car bumper crossbeam assembly structure includes a lightweight bumper crossbeam body 1, an active telescopic energy-absorbing box 2, and a connecting plate 3.

[0043] A pair of active telescopic energy-absorbing boxes 2 are symmetrically fixed at their upper ends to the lower ends of the left and right sides of the lightweight bumper beam body 1; each active telescopic energy-absorbing box 2 is fixedly connected to a connecting plate 3 at its lower end.

[0044] A pair of active telescopic energy-absorbing boxes 2 can drive the lightweight bumper beam body 1 to extend and retract synchronously relative to the connecting plate 3.

[0045] Each active telescopic energy-absorbing box 2 includes a hydraulic cylinder body 21 and a piston rod 22; the piston rod 22 is slidably sleeved inside the hydraulic cylinder body 21, and the free end of the piston rod 22 is detachably fixed to the end of the aligned lightweight bumper beam body 1 through a U-shaped connecting arm 23 fixed to the free end; the piston rod 22 divides the hydraulic cylinder body 21 into a rod chamber 211 and a rodless chamber 212, and the upper side wall of the rod chamber 211 and the lower side wall of the rodless chamber 212 are respectively provided with an oil inlet / outlet a2111 and an oil inlet / outlet b2121.

[0046] Each active telescopic energy-absorbing box 2 has a cross-section with an outer square and inner circle structure.

[0047] Sixteen crushing guide ribs 213 are symmetrically and evenly arranged on the four edges of the outer surface of the cylinder body 21 of each active telescopic energy absorption box 2.

[0048] The lightweight bumper beam body 1 is a hollow tubular cavity structure; the material of the lightweight bumper beam body 1 is aluminum alloy material.

[0049] The lightweight bumper beam body 1 is a hollow multi-tubular cavity structure, and its cross-section is in the shape of a "day" character structure.

[0050] Embodiment 2

[0051] A vehicle includes a front main beam, and also includes the above-mentioned vehicle bumper beam assembly structure. The vehicle bumper beam assembly structure is fixed to the front end face of the front main beam. The connection forms between the active telescopic energy-absorbing box 2, the connecting plate 3 and the front main beam are all welding.

[0052] A vehicle further includes a pressure tube type pedestrian collision detection sensor, an oil storage tank with an oil pump, a vehicle computer and a collision sensor. The front end face of the lightweight bumper beam body 1 running through the transverse dimension is provided with a pressure tube type pedestrian collision detection sensor. The pressure tube type pedestrian collision detection sensor and the collision sensor are respectively electrically connected to the vehicle computer. The vehicle computer is electrically connected to the oil pump of the oil storage tank. The collision sensor is arranged at the front part of the vehicle head sheet metal. The oil pump on the oil storage tank is respectively connected to the oil inlet and outlet a2111 and the oil inlet and outlet b2121 through pipelines.

[0053] Embodiment 3

[0054] See Figures 1-8 As shown, a collision energy absorption method includes an energy absorption method for the bumper beam assembly structure in the pedestrian collision protection mode:

[0055] When the vehicle is in the startup state and maintains the urban road speed limit, a certain volume of oil is injected into the rodless cavity 212 of the active telescopic energy-absorbing box 2. At the same time, an oil-free space V is reserved in the rodless cavity 212, and the oil inlet and outlet b2121 is closed;

[0056] When the pressure tube type pedestrian collision detection sensor identifies a pedestrian collision, the active scheme sensing time ST, the vehicle computer controls the oil pump to quickly inject oil from the oil inlet and outlet a2111; the two left and right piston rods 22 drive the lightweight bumper beam body 1 to move backward a certain displacement L1, and the mechanism execution time DT; within the collision time TTC and the contact beam time HIT, more collision buffer zones are provided for pedestrians to reduce the injury to the pedestrian's leg area during the collision; the active scheme sensing time ST + the mechanism execution time DT < the collision time TTC + the contact beam time HIT;

[0057] After the collision, the vehicle computer can instruct the oil pump to inject a certain volume of oil back into the rodless chamber 212 through the oil inlet / outlet port b2121. At the same time, the vehicle computer instructs the oil pump to evacuate the oil injected into the rod chamber 211 through the oil inlet / outlet port a2111, so that the lightweight bumper beam body 1 returns to its initial position.

[0058] Example 4

[0059] See Figures 1-9 As shown, a collision energy absorption method includes a bumper beam assembly structure energy absorption method for vehicle and occupant space protection modes:

[0060] When the vehicle speed exceeds the speed limit of urban roads, the pedestrian protection sensor will be disabled. When the vehicle collides with other objects at low speed, the collision sensor detects the intensity signal of the collision and the inertial force under the maximum deceleration when the vehicle collides. The signal is then input into the vehicle computer. The vehicle computer determines the position of the active telescopic energy absorption box 2 based on the signal from the collision sensor and drives the oil pump to inject more oil into the inlet and outlet ports b2121 to fill the V space and then close it. The collision impact force is transmitted from the lightweight bumper beam body 1 to the piston rod 22 of the active telescopic energy absorption box 2, which then compresses the oil space to generate resistance and achieve buffering and energy absorption.

[0061] After the collision, the lightweight bumper beam body 1 will be crushed and deformed, while the active telescopic energy absorption box 2 will not be damaged. The lightweight bumper beam body 1 can be replaced by removing the bolts between the active telescopic energy absorption box 2 and the lightweight bumper beam body 1.

[0062] Alternatively, when the vehicle speed exceeds the speed limit on urban roads, the pedestrian protection sensor will be disabled. When the vehicle collides with another vehicle at high speed, the collision sensor sends a signal to the vehicle's computer within a very short time after the collision. The lightweight bumper beam body 1 and the active telescopic energy-absorbing box 2 are crushed. The piston rod 22 of the active telescopic energy-absorbing box 2 moves backward. Even if the oil space is compressed to its limit, it still cannot meet the energy absorption space. The vehicle's computer issues a command to control the oil pump to remove the excess oil in the inlet and outlet ports b2121. The active telescopic energy-absorbing box 2 is naturally crushed under the guidance of several crushing guide ribs 213. At the same time, the vehicle's computer determines whether to detonate the inflatable element to inflate the airbag and other passive safety measures of the vehicle based on the signal from the collision sensor.

[0063] Although the invention has been specifically shown and described in conjunction with preferred embodiments, those skilled in the art should understand that various changes in form and detail may be made to the invention without departing from the spirit and scope of the invention as defined in the appended claims, all of which shall be within the scope of protection of the invention.

Claims

1. A collision energy absorption method, characterized in that: Including pedestrian collision protection mode bumper beam assembly structure energy absorption method: When the car is started and the speed limit on urban roads is maintained, a certain volume of oil is injected into the rodless chamber (212) of the active telescopic energy absorption box (2), while the rodless chamber (212) is reserved with an oil-free space V, and the oil inlet and outlet b (2121) are closed. When the pressure tube pedestrian collision detection sensor identifies a pedestrian collision, the active solution perception time ST, the vehicle computer controls the oil pump to quickly inject oil from the inlet / outlet a (2111); the left and right piston rods (22) drive the lightweight bumper crossbeam body (1) to move backward by a certain displacement L1, the mechanism execution time DT; within the collision time TTC and the contact time HIT, more collision buffer is provided for the pedestrian, reducing the damage to the pedestrian's leg area from the collision; active solution perception time ST + mechanism execution time DT < collision time TTC + contact time HIT; After the collision, the vehicle computer can instruct the oil pump to inject a certain volume of oil into the rodless chamber (212) through the oil inlet / outlet port b (2121). At the same time, the vehicle computer instructs the oil pump to pump out the oil injected into the rod chamber (211) through the oil inlet / outlet port a (2111), so that the lightweight bumper beam body (1) returns to its initial position. The automotive bumper beam assembly structure includes a lightweight bumper beam body (1) and an active telescopic energy-absorbing box (2); the upper ends of a pair of active telescopic energy-absorbing boxes (2) are symmetrically fixed to the lower ends of the left and right sides of the lightweight bumper beam body (1); Each active telescopic energy-absorbing box (2) includes a cylinder body (21) and a piston rod (22); the piston rod (22) is slidably sleeved inside the cylinder body (21); the piston rod (22) divides the cylinder body (21) into a rod chamber (211) and a rodless chamber (212), and the upper side wall of the rod chamber (211) and the lower side wall of the rodless chamber (212) are respectively provided with an oil inlet / outlet a (2111) and an oil inlet / outlet b (2121).

2. The collision energy absorption method according to claim 1, characterized in that: Including energy absorption methods for the bumper beam assembly structure in vehicle and passenger space protection modes: When the car speed exceeds the speed limit of urban roads, the pedestrian protection sensor will be disabled. When the car collides with other objects at low speed, the collision sensor detects the intensity signal of the car collision, detects the inertial force under the maximum deceleration when the car collides, and inputs the signal into the vehicle computer. The vehicle computer determines the position of the active telescopic energy absorption box (2) based on the signal of the collision sensor and drives the oil pump to inject more oil into the inlet and outlet ports b (2121) to fill the V space and then closes it. The collision impact force is transmitted from the lightweight bumper beam body (1) to the piston rod (22) of the active telescopic energy absorption box (2) and then compresses the oil space to generate resistance to achieve buffering and energy absorption. After the collision, the lightweight bumper beam body (1) will be crushed and deformed, and the active telescopic energy absorption box (2) will not be damaged. The new lightweight bumper beam body (1) can be replaced by removing the bolts between the active telescopic energy absorption box (2) and the lightweight bumper beam body (1). Alternatively, when the vehicle speed exceeds the speed limit on urban roads, the pedestrian protection sensor will be disabled. When the vehicle has a high-speed collision with other vehicles, within an extremely short time after the collision occurs, the collision sensor sends a signal to the vehicle computer. The lightweight bumper beam main body (1) and the active telescopic energy-absorbing box (2) structure are crushed. The end of the piston rod (22) of the active telescopic energy-absorbing box (2) moves backward. The oil hydraulic space is compressed to the limit but still cannot meet the energy-absorbing space. The vehicle computer issues an instruction to control the oil pump to discharge the excess oil in the oil inlet and outlet b (2121). The active telescopic energy-absorbing box (2) is naturally crushed under the guidance of several crushing guiding ribs (213). At the same time, the vehicle computer determines whether to detonate the inflatable element to inflate the airbag and other passive safety measures of the vehicle according to the signal of the collision sensor; On the four edges of the outer surface of the cylinder block (21) of each active telescopic energy-absorbing box (2), several crushing guiding ribs (213) are symmetrically and evenly arranged.

3. A car bumper crossbeam assembly structure, characterized in that, For implementing the collision energy absorption method described in claim 2; It includes a lightweight bumper beam main body (1), an active telescopic energy-absorbing box (2), and a connecting plate (3); A pair of upper ends of the active telescopic energy-absorbing boxes (2) are symmetrically fixed to the lower end surfaces of the left and right sides of the lightweight bumper beam main body (1); a connecting plate (3) is fixedly connected to the lower end of each active telescopic energy-absorbing box (2); A pair of active telescopic energy-absorbing boxes (2) can drive the lightweight bumper beam main body (1) to synchronously expand and contract relative to the connecting plate (3).

4. The automotive bumper crossbeam assembly structure according to claim 3, characterized in that: Each active telescopic energy-absorbing box (2) includes a cylinder block (21) and a piston rod (22); the piston rod (22) is slidably sleeved in the cylinder block (21). The free end of the piston rod (22) is detachably fixed to the end of the corresponding lightweight bumper beam main body (1) through a U-shaped connecting arm (23) fixed to the free end; the piston rod (22) divides the cylinder block (21) into a rod chamber (211) and a rodless chamber (212), and an oil inlet and outlet a (2111) and an oil inlet and outlet b (2121) are respectively provided on the upper side wall of the rod chamber (211) and the lower side wall of the rodless chamber (212).

5. The automotive bumper crossbeam assembly structure according to claim 4, characterized in that: The cross-section of the cylinder block (21) of each active telescopic energy-absorbing box (2) has an outer square and inner circular structure.

6. The automotive bumper crossbeam assembly structure according to claim 5, characterized in that: On the four edges of the outer surface of the cylinder block (21) of each active telescopic energy-absorbing box (2), several crushing guiding ribs (213) are symmetrically and evenly arranged.

7. The automotive bumper crossbeam assembly structure according to claim 6, characterized in that: The lightweight bumper beam main body (1) is a hollow tubular cavity structure; the material of the lightweight bumper beam main body (1) is aluminum alloy material.

8. The automotive bumper crossbeam assembly structure according to claim 7, characterized in that: The lightweight bumper beam main body (1) is a hollow multi-tubular cavity structure, and its cross-section has a structure of "day" shape, "eye" shape or "field" shape.

9. A car, characterized in that: It includes a front main beam, and also includes the vehicle bumper beam assembly structure described in any one of claims 3-8. The vehicle bumper beam assembly structure is fixed to the front end face of the front main beam. The connection forms between the active telescopic energy-absorbing box (2), the connecting plate (3), and the front main beam are welding, chemical bonding or screwing connection.

10. A car according to claim 9, characterized in that: It also includes a pressure tube pedestrian collision detection sensor, an oil tank with an oil pump, a vehicle computer and a collision sensor. The lightweight bumper beam body (1) has a pressure tube pedestrian collision detection sensor installed on the front end face through the transverse dimension. The pressure tube pedestrian collision detection sensor and the collision sensor are electrically connected to the vehicle computer, and the vehicle computer is electrically connected to the oil pump of the oil tank. The collision sensor is installed at the front of the vehicle body sheet metal. The oil pump on the oil tank is connected to the oil inlet / outlet a (2111) and the oil inlet / outlet b (2121) through pipelines.

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