Self-adaptive lifting truck rear underrun protection device

Abstract

The invention discloses a self-adaptive lifting truck rear underrun protection device, which belongs to the technical field of vehicle equipment, and comprises at least one group of protection components arranged at the bottom of a frame; the protection assembly comprises a swing arm and a pull rod. The top end of the swing arm is rotationally connected with the frame through a swing arm seat, a swing arm hole is formed in the middle of the swing arm, a sliding pin is arranged in the swing arm hole, the bottom end of the swing arm is connected with a rolling shaft, and a plurality of rollers are rotationally connected to the rolling shaft; the top end of the pull rod is rotationally connected with the frame through a pull rod seat, the bottom end of the pull rod extends into the swing arm hole, and a strip-shaped sliding groove is formed in the pull rod and is in sliding fit with the sliding pin; the outer side of the pull rod is sleeved with a spring, and the spring limits the sliding pin to the bottom end of the strip-shaped sliding groove. According to the protection device, the edge height and the tail departure angle can be adjusted in a self-adaptive mode according to the driving environment, the rear lower protection device can be lifted up completely in a self-adaptive mode when goods are loaded and unloaded at the position close to a local abrupt slope or a road surface obstacle in a backing-up mode, and the protection device is automatically restored to the normal working position after operation is completed.

Description

Technical Field

[0001] This invention relates to the field of vehicle equipment technology, and more specifically to an adaptive lifting rear underrun protection device for trucks. Background Technology

[0002] Currently, heavy and medium-duty trucks generally have high chassis. To prevent smaller vehicles from going under the truck in a rear-end collision and causing serious injuries or fatalities, the current national mandatory standards require that trucks with a gross vehicle weight greater than 3,500 kg, special-purpose vehicles modified from truck chassis, and trailers be equipped with rear underrun protection devices to protect the truck's driving safety and vehicles behind it.

[0003] Because national standards require that the lower edge of the rear underrun protection device should not be more than 500mm off the ground when the vehicle is unloaded, and existing truck rear underrun protection devices are not adjustable or cannot be adaptively adjusted according to the driving environment, the rear height and departure angle of the truck are greatly reduced after the installation of the rear underrun protection device. This seriously affects the truck's passability on mountain roads and uneven road surfaces. It is not convenient for the truck to pass through sections with steep slopes or road obstacles or to load and unload goods with the rear of the vehicle close to the ground. It is also easy for the rear underrun protection device to be scraped and damaged by the ground. Summary of the Invention

[0004] The purpose of this invention is to provide an adaptive lifting rear underrun protection device for trucks, in order to solve the problem that existing truck rear underrun protection devices are not convenient to adapt to the driving environment and are prone to contact with the ground, resulting in scratches and damage.

[0005] The technical solution of the present invention to solve the above-mentioned technical problems is as follows:

[0006] An adaptive lifting rear underrun protection device for a truck includes: at least one set of protection components disposed at the bottom of the vehicle frame; the protection components include a swing arm and a tie rod;

[0007] The top of the swing arm is rotatably connected to the frame via a swing arm seat. The middle of the swing arm has a swing arm hole with a sliding pin inside. The bottom of the swing arm is connected to a roller, and several rollers are rotatably connected to the roller.

[0008] The top of the tie rod is rotatably connected to the frame via a tie rod seat, and the bottom of the tie rod extends into the swing arm hole. The tie rod is provided with a strip groove, which slides in conjunction with a sliding pin. A spring is fitted on the outside of the tie rod, which restricts the sliding pin at the bottom of the strip groove.

[0009] Furthermore, the top of the aforementioned swing arm is provided with a strip-shaped buffer hole, and the top of the swing arm is connected to the swing arm seat through the swing arm shaft, with the swing arm shaft and the strip-shaped buffer hole slidingly engaged.

[0010] Furthermore, the top of the aforementioned swing arm extends into the swing arm seat, and a buffer pad is provided between the top of the swing arm and the inner wall of the swing arm seat.

[0011] Furthermore, the bottom end of the aforementioned pull rod is fitted with a U-shaped sleeve and is rotatably connected to the U-shaped sleeve. A sliding pin passes through the U-shaped sleeve and is slidably engaged with the U-shaped sleeve. A spring seat is provided near the top of the pull rod, and the spring is located between the U-shaped sleeve and the spring seat.

[0012] Furthermore, the aforementioned protective components consist of two sets, which are arranged in parallel, and the swing arms of the two sets of protective components are connected to the same roller.

[0013] Furthermore, the aforementioned swing arms are connected to support rods, and all support rods and all swing arms are connected to the same roller.

[0014] Furthermore, the aforementioned adaptive lifting rear underrun protection device for trucks also includes a limiting component, which includes an electromagnetic lock core, an electromagnetic lock armature, and a pressure control switch; the electromagnetic lock core and the electromagnetic lock armature are respectively connected to the pull rod and the swing arm and are arranged opposite to each other, and the pressure control switch is located inside the electromagnetic lock core and extends out of the electromagnetic lock core towards the side of the electromagnetic lock armature.

[0015] The first terminal of the pressure control switch is electrically connected to one of the electrodes of the power supply, and the first and second terminals of the electromagnetic lock core are electrically connected to the second terminal of the pressure control switch and the other electrode of the power supply, respectively.

[0016] When the electromagnetic lock cylinder comes into contact with the electromagnetic lock armature, the electromagnetic lock armature presses the pressure control switch, energizing the electromagnetic lock cylinder and attracting the electromagnetic lock armature.

[0017] Furthermore, the aforementioned adaptive lifting rear underrun protection device for trucks also includes a control component; the control component includes a first switch-type Hall integrated circuit H1, a second switch-type Hall integrated circuit H2, a first magnet and a second magnet, as well as a normally closed relay M1 and a power-off delay relay M2, all mounted on the same wheel; the first switch-type Hall integrated circuit H1 and the second switch-type Hall integrated circuit H2 are mounted on the brake base plate of the wheel and arranged sequentially from the inside to the outside along the radial direction of the wheel; the first magnet and the second magnet are mounted on the end face of the brake drum of the wheel, and the first magnet and the second magnet can respectively trigger and conduct the first switch-type Hall integrated circuit H1 and the second switch-type Hall integrated circuit H2 after the wheel rotates, the first magnet and the second magnet are misaligned relative to the circumference of the wheel to form a misalignment circumferential angle δ, so that the first switch-type Hall integrated circuit H1 and the second switch-type Hall integrated circuit H2 will not be triggered and conducted simultaneously;

[0018] The first terminal of the first switch-type Hall integrated circuit H1 is electrically connected to the second terminal of the voltage-controlled switch. The second terminal of the first switch-type Hall integrated circuit H1 is electrically connected to the first terminal of the normally closed relay M1. The third terminal of the first switch-type Hall integrated circuit H1 is electrically connected to the second terminal of the electromagnetic lock core. The second terminal of the normally closed relay M1 is electrically connected to the second terminal of the electromagnetic lock core. The contact terminal of the normally closed relay M1 is electrically connected to the first terminal of the electromagnetic lock core.

[0019] The first terminal of the second switch-type Hall integrated circuit H2 is electrically connected to the second terminal of the voltage-controlled switch. The second terminal of the second switch-type Hall integrated circuit H2 is electrically connected to the first terminal of the power-off delay relay M2. The third terminal of the second switch-type Hall integrated circuit H2 is electrically connected to the second terminal of the electromagnetic lock core. The second terminal of the power-off delay relay M2 is electrically connected to the second terminal of the electromagnetic lock core. The contact of the power-off delay relay M2 is electrically connected to the first terminal of the normally closed relay M1.

[0020] Furthermore, the delay time of the aforementioned power-off delay relay M2 is 3 seconds.

[0021] Furthermore, the aforementioned electromagnetic lock cylinder is connected in parallel with the car's hazard warning lights.

[0022] The present invention has the following beneficial effects:

[0023] This invention provides an adaptively height-adjustable rear underrun protection device for trucks. When the vehicle is driving on uneven roads, the height of the lower edge of the rear underrun protection device and the departure angle of the rear of the vehicle can be adaptively adjusted. When reversing to load or unload goods near a local steep slope or road obstacle, the rear underrun protection device can be temporarily raised as needed. When the loading and unloading operation is completed and the vehicle leaves, the device will automatically return to its normal working position, thereby improving the vehicle's passability and preventing damage to the protection device. Attached Figure Description

[0024] Figure 1 A longitudinal structural schematic diagram of the adaptive lifting rear underrun protection device for trucks provided in an embodiment of the present invention;

[0025] Figure 2 A schematic diagram of the transverse structure of the adaptive lifting rear underrun protection device for trucks provided in an embodiment of the present invention;

[0026] Figure 3 A schematic diagram of the structure of the pull rod provided for an embodiment of the present invention;

[0027] Figure 4 A schematic diagram of the mounting structure end face of the control component provided in an embodiment of the present invention;

[0028] Figure 5 A schematic cross-sectional view of the installation structure of the control component provided in an embodiment of the present invention.

[0029] Figure 6 A control circuit diagram of a control component provided for an embodiment of the present invention;

[0030] Figure 7 This is a diagram illustrating the usage state of an adaptive lifting rear underrun protection device for a truck, provided as an embodiment of the present invention, wherein the electromagnetic lock core and the electromagnetic lock armature are attracted together.

[0031] In the diagram: 10-Frame; 11-Wheel; 12-Brake base plate; 13-Brake drum; 21-Swing arm; 22-Tie rod; 23-Swing arm seat; 24-Swing arm hole; 25-Sliding pin; 26-Roller; 27-Tie rod seat; 28-Strip groove; 29-Spring; 30-Strip buffer hole; 31-Swing arm shaft; 32-Buffer pad; 33-U-shaped sleeve; 34-Spring seat; 35-Support rod; 36-Roller; 41-Electromagnetic lock core; 42-Electromagnetic lock armature; 43-Pressure control switch; 44-Alarm flashing light; 51-First magnet; 52-Second magnet; H1-First switch-type Hall integrated circuit; H2-Second switch-type Hall integrated circuit; M1-Normally closed relay; M2-Power-off delay relay. Detailed Implementation

[0032] The principles and features of the present invention are described below with reference to the accompanying drawings. The examples given are only for explaining the present invention and are not intended to limit the scope of the present invention.

[0033] like Figures 1 to 3 As shown, this embodiment provides an adaptive lifting rear underrun protection device for a truck, including: at least one set of protection components disposed at the bottom of the frame 10, the protection components including a swing arm 21 and a pull rod 22. The top end of the swing arm 21 is rotatably connected to the bottom of the frame 10, and the top end of the pull rod 22 is rotatably connected to the bottom of the frame 10. The connection point of the pull rod 22 to the frame 10 is closer to the rear of the truck 10 than the connection point of the swing arm 21 to the frame 10. Preferably, the line connecting the connection points of the pull rod 22 and the swing arm 21 is aligned with the length direction of the truck. The bottom end of the swing arm 21 is connected to a plurality of rollers 36 via a roller 26. The rollers 36 are preferably made of rubber. The bottom end of the pull rod 22 passes through the middle of the swing arm 21 and slides to adjust the height of the rollers 36. Preferably, the extension direction of the roller 26 is the width direction of the truck, and all rollers 36 are parallel and spaced apart on the roller 26 and can rotate on the roller 26.

[0034] When the number of protective components is greater than one, all protective components are arranged in parallel. They can each have their own roller 26 or share a single roller 26. In this embodiment, there are two sets of protective components, which are arranged at intervals and share a single roller 26 to improve the overall stability of the entire protective device.

[0035] The top end of the swing arm 21 has a strip-shaped buffer hole 30 extending along its extension direction. A swing arm shaft 31 is slidably disposed within the strip-shaped buffer hole 30. Both ends of the swing arm shaft 31 are connected to the swing arm seat 23, which is fixedly connected to the bottom of the frame 10. The strip-shaped buffer hole 30 is used to provide a certain buffer space when the roller 36 is subjected to compressive force. In order to further absorb impact loads, in this embodiment, the top of the swing arm 21 extends into the interior of the swing arm seat 23, and a buffer pad 32 is provided between the inner wall of the swing arm seat 23 and the top of the swing arm 21.

[0036] The swing arm 21 has a swing arm hole 24 in the middle for the pull rod 22 to pass through, and a sliding pin 25 is provided in the swing arm hole 24. The bottom ends of the swing arms 21 of the two sets of protective components are connected by the same roller 26. In order to improve the support of the roller 26 and the overall integrity of the protective device, each swing arm 21 is provided with a support rod 35, which is also connected to the roller 26. Therefore, the roller 26 has 4 support points, which improves the stability of the roller 26.

[0037] The top end of the pull rod 22 is rotatably connected to the pull rod seat 27 via a pull rod shaft. The pull rod seat 27 is fixedly connected to the bottom of the frame 10. The bottom of the pull rod 22 passes through the swing arm hole 24 and can move within the swing arm hole 24. The middle part of the pull rod 22 is provided with a strip-shaped groove 28 arranged along its extension direction. The sliding pin 25 passes through the strip-shaped groove 28 and can slide and rotate within the strip-shaped groove 28. In the initial position, the sliding pin 25 is located at the bottom end of the strip-shaped groove 28. A spring 29 is sleeved on the outside of the pull rod 22 to press the sliding pin 25 against the bottom end of the strip-shaped groove 28. When the roller 36 is impacted by the rear trolley, the swing arm 21 will resist the forward displacement of the roller 36 and the roller shaft 26 to prevent the trolley from entering the bottom of the vehicle. At the same time, the roller 36 and the buffer pad 32 can absorb part of the impact load through elastic deformation. When the bottom of the roller 36 is pressed by a raised ground or obstacle, the roller 36 will drive the swing arm 21 to rotate upward. At this time, the sliding pin 25 slides upward in the strip groove 28, and the spring 29 is compressed. At the same time, the roller 36 also avoids the roller shaft 26 being damaged by the friction of the ground or obstacle by its own rotation. When the roller 36 leaves the raised ground or obstacle, the swing arm 21 will return to the initial position under the action of gravity and the elastic force of the spring 29.

[0038] In this embodiment, the bottom of the pull rod 22 is provided with a U-shaped sleeve 33. The bottom of the pull rod 22 passes through the U-shaped sleeve 33 and slides in engagement with the U-shaped sleeve 33. The U-shaped sleeve 33 is located outside the swing arm hole 24. The sliding pin 25 passes through the U-shaped sleeve 33 and rotates in engagement with the U-shaped sleeve 33. The U-shaped sleeve 33 serves as a force-bearing component, used to transmit pressure and elastic force between the spring 29 and the sliding pin 25.

[0039] A spring seat 34 is fitted near the top of the pull rod 22, and the spring 29 is located between the spring seat 34 and the U-shaped sleeve 33.

[0040] The adaptive lifting rear underrun protection device for trucks provided in this embodiment also includes a limiting component, which includes an electromagnetic lock core 41, an electromagnetic lock armature 42, and a pressure control switch 43. The electromagnetic lock core 41 is mounted on the spring seat 34, and the electromagnetic lock armature 42 is mounted on the top of the U-shaped sleeve 33. The electromagnetic lock core 41 and the electromagnetic lock armature 42 are positioned opposite each other. The pressure control switch 43 is located inside the electromagnetic lock core 41 and extends out of the electromagnetic lock core 41 towards the electromagnetic lock armature 42. When the swing arm 21 moves upward to its limit position, the electromagnetic lock core 41 contacts the electromagnetic lock armature 42, and the electromagnetic lock armature 42 presses the pressure control switch 43, energizing the electromagnetic lock core 41 and attracting it to the electromagnetic lock armature 42, thus fixing the swing arm 21 at its upward limit position.

[0041] The first end of the pressure control switch 43 is electrically connected to one of the electrodes of the power supply, and the first and second ends of the electromagnetic lock core 41 are electrically connected to the second end of the pressure control switch 43 and the other electrode of the power supply, respectively.

[0042] When the electromagnetic lock cylinder 41 and the electromagnetic lock armature 42 are attracted together, the electromagnetic lock cylinder 41 and the electromagnetic lock armature 42 can be separated manually, or the separation can be performed automatically by the control component.

[0043] like Figure 4 and Figure 5 As shown, the control components include a first switch-type Hall integrated circuit H1, a second switch-type Hall integrated circuit H2, a first magnet 51 and a second magnet 52, all mounted on the same wheel 11, as well as a normally closed relay M1 and a power-off delay relay M2. The first switch-type Hall integrated circuit H1 and the second switch-type Hall integrated circuit H2 are mounted on the brake base plate 12 of the wheel 11 and arranged sequentially from the inside to the outside along the radial direction of the wheel 11. The first magnet 51 and the second magnet 52 are mounted on the end face of the brake drum 13 of the wheel 11. As the wheel 11 rotates, the first magnet 51 and the second magnet 52 can respectively activate and conduct the first switch-type Hall integrated circuit H1 and the second switch-type Hall integrated circuit H2. The first magnet 51 and the second magnet 52 are misaligned relative to the circumference of the wheel 11, forming a misalignment circumferential angle δ, preventing the first switch-type Hall integrated circuit H1 and the second switch-type Hall integrated circuit H2 from being activated simultaneously. In this embodiment, when the vehicle moves forward, the second switch-type Hall integrated circuit H2 will conduct before the first switch-type Hall integrated circuit H1.

[0044] like Figure 6As shown, the circuit connection between the control component and the limit component is as follows: the first terminal of the first switch-type Hall integrated circuit H1 is electrically connected to the second terminal of the pressure control switch 43; the second terminal of the first switch-type Hall integrated circuit H1 is electrically connected to the first terminal of the normally closed relay M1; the third terminal of the first switch-type Hall integrated circuit H1 is electrically connected to the second terminal of the electromagnetic lock core 41; the second terminal of the normally closed relay M1 is electrically connected to the second terminal of the electromagnetic lock core 41; and the contact of the normally closed relay M1 is electrically connected to the first terminal of the electromagnetic lock core 41.

[0045] The first terminal of the second switch-type Hall integrated circuit H2 is electrically connected to the second terminal of the voltage-controlled switch 43. The second terminal of the second switch-type Hall integrated circuit H2 is electrically connected to the first terminal of the power-off delay relay M2. The third terminal of the second switch-type Hall integrated circuit H2 is electrically connected to the second terminal of the electromagnetic lock core 41. The second terminal of the power-off delay relay M2 is electrically connected to the second terminal of the electromagnetic lock core 41. The contact of the power-off delay relay M2 is electrically connected to the first terminal of the normally closed relay M1.

[0046] Preferably, the delay time of the power-off delay relay M2 is 3s, and the electromagnetic lock core 41 is connected in parallel with the car's alarm flasher 44.

[0047] like Figure 1 and Figure 7 As shown, the automatic control principle of the adaptive lifting rear underrun protection device for trucks in this embodiment is as follows:

[0048] (1) When the protective device is in the normal working position, the sliding pin 25 is located at the bottom of the strip groove 28, the pressure control switch 43 is in the open circuit state, and the control circuit is in the non-working state.

[0049] (2) When the swing arm 21 rotates upward to the limit position under the action of external force, the sliding pin 25 is close to the top of the strip groove 28 or located at the top of the strip groove 28. The electromagnetic lock core 41 is in contact with the electromagnetic lock armature 42, the pressure control switch 43 is pressed and turned on, and the current is turned on by the contact of the normally closed relay M1 to energize the electromagnetic lock core 41 and generate electromagnetic force, which attracts and fixes the electromagnetic lock armature 42, fixing the protective device in the upward limit position. At the same time, the car's alarm flashing light 44 is energized and works.

[0050] With the protective device fixed in the upward limit position, if the vehicle moves forward, as the brake drum 13 rotates forward, the second switch-type Hall integrated circuit H2 will turn on and off before the first switch-type Hall integrated circuit H1. The turning on of the second switch-type Hall integrated circuit H2 will cause the power-off delay relay M2 to activate and deactivate after a certain delay t (preferably 3 seconds). For a truck with a wheel radius of R, when its forward speed is less than... When the power-off delay relay M2 is activated, it will disconnect due to the expiration of the delay before the first switch-type Hall integrated circuit H1 is turned on. The normally closed relay M1 remains in the conducting state, meaning the electromagnetic lock core 41 is continuously engaged with the electromagnetic lock armature 42, keeping the protective device in its highest position. When its forward speed exceeds [a certain value], [the device will remain in the highest position]. At this time, the first switch-type Hall integrated circuit H1 will conduct before the power-off delay relay M2 is disconnected. The coil current of the normally closed relay M1 is turned on, the contacts are opened, the electromagnetic lock core 41 loses its attraction to the electromagnetic lock armature 42, the pressure control switch 43 is released, the control circuit is cut off from power, and the protective device returns to its initial position under the combined action of gravity and spring 29. Thus, by reasonably setting the offset circumferential angle δ, it can be achieved that after the vehicle is actively lifted, the protective device will automatically return to the normal protective position unless it is moving forward at a very low speed.

[0051] With the protective device fixed in the upward extreme position, if the car reverses, as the brake drum 13 rotates backward, the first switch-type Hall integrated circuit H1 will turn on and off before the second switch-type Hall integrated circuit H2. Therefore, when the reversing speed is lower than... When the power-off delay relay M2 contacts are opened before the first switch-type Hall integrated circuit H1 is turned on, the normally closed relay M1 remains in the conducting state, that is, the electromagnetic lock core 41 is continuously engaged with the electromagnetic lock armature 42, keeping the protective device in the highest position; when the reversing speed is higher than At that time, since the conduction time of the first switch-type Hall integrated circuit H1 is earlier than the contact opening time of the power-off delay relay M2, the coil current of the normally closed relay M1 is turned on and the contacts are opened. The electromagnetic lock core 41 loses its attraction force on the electromagnetic lock armature 42, the pressure control switch 43 is released, the power supply to the control circuit is cut off, and the protective device returns to its initial position under the action of gravity and spring 29. Thus, when the car is reversing at a low speed, the protective device remains in an upward-raised state; while when reversing at a higher speed, the protective device can be promptly restored to its normal protective position.

[0052] The protective principle of the adaptive lifting rear underrun protection device for trucks in this embodiment is as follows:

[0053] (1) When the truck is traveling on an uneven surface and the roller 36 touches the ground, in addition to eliminating the tangential friction of the ground by rolling, the roller 36 also transmits the normal pressure of the ground to the swing arm 21 through the roller 26. The vertical component of this normal pressure along the swing arm 21 will generate an upward swinging torque on the swing arm 21, and through the sliding pin 25, it will drive the U-shaped sleeve 33 to slide along the strip groove 28 to compress the spring 29, so that the swing arm 21 can swing upward around the swing arm axis 31. At the same time, the tie rod 22 swings forward and upward around the tie rod axis. Meanwhile, the longitudinal component of the normal pressure of the ground along the swing arm 21 causes the swing arm 21 to move forward axially along the front strip buffer hole 30, and after the end of the swing arm 21 is squeezed against the buffer pad 32 to mitigate the action, it is transmitted to the frame 10, thereby automatically raising the height of the protective device and mitigating the external force on the protective device from the ground, so as to avoid the protective device being scratched and damaged.

[0054] (2) When the rear of the truck is rear-ended by a small car, the collision process is first partially mitigated by the rubber elasticity of the roller 36 to reduce the impact and the resulting loss. Then, since the collision force is parallel or nearly parallel to the longitudinal direction of the vehicle body, the vertical component of the collision force on the roller 26 along the swing arm 21 points to the ground, causing the swing arm 21 to generate a downward swinging torque around the swing arm axis 31. Since the downward movement of the sliding pin 25 is constrained by the tie rod 22, the tie rod axis, the tie rod seat 27 and the frame 10, the downward swinging torque will not actually cause the swing to swing downward. Meanwhile, the longitudinal component of the impact force on the roller 26 along the swing arm 21 will cause the swing arm 21 to move forward axially along the strip-shaped buffer hole 30 at its front end. The impact load is then mitigated by the compression of its end against the buffer pad 32 before being transmitted to the frame 10. When the buffer pad 32 is compressed, causing the end face of the long strip hole of the swing arm 21 to contact the swing arm shaft 31, the longitudinal movement of the swing arm 21 stops due to the constraint of the swing arm shaft 31, the buffer pad 32, and the swing arm seat 23. This prevents the small vehicle involved in the rear-end collision from moving forward and going under the truck. During this process, the impact force is applied to the truck frame 10 in a relatively gentle manner by the buffer pad 32, further reducing the impact impulse and mitigating accident damage, thus effectively achieving the protective purpose.

[0055] (3) When the vehicle needs to move backward to a slope or protrusion close to the ground due to special circumstances such as loading or unloading goods, the swing arm 21 can be raised in advance to make the electromagnetic lock core 41 and the electromagnetic lock armature 42 fit together. At this time, the control circuit is activated, and the electromagnetic force generated by the electromagnetic lock core 41 firmly attracts the electromagnetic lock armature 42, so that the entire protective device is at its maximum ground clearance. At the same time, the vehicle's warning flashing lights are activated to alert vehicles and personnel behind to pay attention to safety. Afterward, as the wheels 11 roll backward at a low speed, the electromagnetic lock core 41 is in a continuous state of attraction to the electromagnetic lock armature 42, keeping the protective device in the highest position, and the vehicle can continue to move backward to a position close to the ground protrusion. When the vehicle finishes moving backward to approach the slope or protrusion and turns forward, as the wheels 11 roll forward and the vehicle speed reaches After the above steps, the electromagnetic lock core 41 loses its attraction to the electromagnetic lock armature 42. Under the combined action of gravity and spring 29, the protective device returns to its normal protective position. The vehicle's warning lights 44 also stop working simultaneously, allowing the driver to automatically restore the protective function of the rear lower protective device without special operation, thus ensuring driving safety. Through the above steps, when a truck needs to actively move backward to approach a slope or protrusion due to special circumstances such as loading or unloading goods, it can adjust its parking position by slowly moving forward or backward. Furthermore, it ensures that when the truck finishes moving backward to approach the slope or protrusion and begins normal forward movement, the protective device automatically returns to its normal protective position.

[0056] The above description is only a preferred embodiment of the present invention and is not intended to limit the present invention. Any modifications, equivalent substitutions, improvements, etc., made within the spirit and principles of the present invention should be included within the protection scope of the present invention.

Claims

1. An adaptive lifting rear underrun protection device for trucks, characterized in that, include: At least one set of protective components disposed at the bottom of the frame (10); the protective components include a swing arm (21) and a tie rod (22). The top end of the swing arm (21) is rotatably connected to the frame (10) via the swing arm seat (23). The middle part of the swing arm (21) is provided with a swing arm hole (24). A sliding pin (25) is provided in the swing arm hole (24). The bottom end of the swing arm (21) is connected to a roller (26). Several rollers (36) are rotatably connected to the roller (26). The top end of the pull rod (22) is rotatably connected to the frame (10) through the pull rod seat (27), and the bottom end of the pull rod (22) extends into the swing arm hole (24). The pull rod (22) is provided with a strip groove (28), and the strip groove (28) is slidably engaged with the sliding pin (25). A spring (29) is sleeved on the outside of the pull rod (22), and the spring (29) restricts the sliding pin (25) to the bottom end of the strip groove (28).

2. The adaptive lifting rear underrun protection device for trucks according to claim 1, characterized in that, The top of the swing arm (21) is provided with a strip-shaped buffer hole (30). The top of the swing arm (21) is connected to the swing arm seat (23) through the swing arm shaft (31). The swing arm shaft (31) and the strip-shaped buffer hole (30) are in sliding cooperation.

3. The adaptive lifting rear underrun protection device for trucks according to claim 2, characterized in that, The top of the swing arm (21) extends into the swing arm seat (23), and a buffer pad (32) is provided between the top of the swing arm (21) and the inner wall of the swing arm seat (23).

4. The adaptive lifting rear underrun protection device for trucks according to claim 1, characterized in that, The bottom end of the pull rod (22) is fitted with a U-shaped sleeve (33) and slides with the U-shaped sleeve (33). The sliding pin (25) passes through the U-shaped sleeve (33) and is rotatably connected with the U-shaped sleeve (33). A spring seat (34) is provided near the top of the pull rod (22). The spring (29) is located between the U-shaped sleeve (33) and the spring seat (34).

5. The adaptive lifting rear underrun protection device for trucks according to claim 1, characterized in that, The protective components are in two sets, which are arranged in parallel, and the swing arms (21) of the two sets of protective components are connected to the same roller (26).

6. The adaptive lifting rear underrun protection device for trucks according to claim 5, characterized in that, The swing arm (21) is connected to a support rod (35), and all the support rods (35) and all the swing arms (21) are connected to the same roller (26).

7. The adaptive lifting rear underrun protection device for trucks according to any one of claims 1 to 6, characterized in that, It also includes a limiting component, which includes an electromagnetic lock core (41), an electromagnetic lock armature (42), and a pressure control switch (43); the electromagnetic lock core (41) and the electromagnetic lock armature (42) are respectively connected to the pull rod (22) and the swing arm (21) and are arranged opposite to each other; the pressure control switch (43) is disposed inside the electromagnetic lock core (41) and extends out of the electromagnetic lock core (41) on the side facing the electromagnetic lock armature (42); The first end of the pressure control switch (43) is electrically connected to one of the electrodes of the power supply, and the first and second ends of the electromagnetic lock core (41) are electrically connected to the second end of the pressure control switch (43) and the other electrode of the power supply, respectively. When the electromagnetic lock core (41) comes into contact with the electromagnetic lock armature (42), the electromagnetic lock armature (42) presses the pressure control switch (43), so that the electromagnetic lock core (41) is energized and attracts the electromagnetic lock armature (42).

8. The adaptive lifting rear underrun protection device for trucks according to claim 7, characterized in that, It also includes a control component; the control component includes a first switch-type Hall integrated circuit H1, a second switch-type Hall integrated circuit H2, a first magnet (51) and a second magnet (52) disposed on the same wheel (11), as well as a normally closed relay M1 and a power-off delay relay M2; the first switch-type Hall integrated circuit H1 and the second switch-type Hall integrated circuit H2 are disposed on the brake base plate (12) of the wheel (11) and are arranged sequentially from the inside to the outside along the radial direction of the wheel (11); the first magnet (51) and the second magnet (52) The first magnet (51) and the second magnet (52) are disposed on the end face of the brake drum (13) of the wheel (11), and the first magnet (51) and the second magnet (52) can respectively trigger the first switch-type Hall integrated circuit H1 and the second switch-type Hall integrated circuit H2 after the wheel (11) rotates. The first magnet (51) and the second magnet (52) are misaligned relative to the circumferential direction of the wheel (11) to form a misaligned circumferential angle δ, so that the first switch-type Hall integrated circuit H1 and the second switch-type Hall integrated circuit H2 will not be triggered and turned on at the same time. The first terminal of the first switch-type Hall integrated circuit H1 is electrically connected to the second terminal of the voltage-controlled switch (43), the second terminal of the first switch-type Hall integrated circuit H1 is electrically connected to the first terminal of the normally closed relay M1, the third terminal of the first switch-type Hall integrated circuit H1 is electrically connected to the second terminal of the electromagnetic lock core (41), the second terminal of the normally closed relay M1 is electrically connected to the second terminal of the electromagnetic lock core (41), and the contact of the normally closed relay M1 is electrically connected to the first terminal of the electromagnetic lock core (41). The first terminal of the second switch-type Hall integrated circuit H2 is electrically connected to the second terminal of the voltage-controlled switch (43), the second terminal of the second switch-type Hall integrated circuit H2 is electrically connected to the first terminal of the power-off delay relay M2, the third terminal of the second switch-type Hall integrated circuit H2 is electrically connected to the second terminal of the electromagnetic lock core (41), the second terminal of the power-off delay relay M2 is electrically connected to the second terminal of the electromagnetic lock core (41), and the contact of the power-off delay relay M2 is electrically connected to the first terminal of the normally closed relay M1.

9. The adaptive lifting rear underrun protection device for trucks according to claim 8, characterized in that, The delay time of the power-off delay relay M2 is 3 seconds.

10. The adaptive lifting rear underrun protection device for trucks according to claim 7, characterized in that, The electromagnetic lock core (41) is connected in parallel with the car's alarm flasher (44).

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