A truck and a rear protection device for a truck

Abstract

The application discloses a truck and a truck rear protection device, which comprises a support, a protection beam and a lifting mechanism, a guide groove is arranged on the support, the protection beam is slidably connected to the support, the lifting mechanism comprises a power member and a guide rod, the guide rod is slidably connected to the guide groove, the guide rod is connected to the protection beam, the power member is installed on the support, an output shaft of the power member is connected to the guide rod, so as to adjust the ground clearance of the protection beam, the ground clearance of the protection beam is adjusted in a range of 300mm-500mm, and the application has the beneficial effects that the protection beam can be actively lifted when the truck is fully loaded and the body is sunken, the defects of the traditional fixed protection structure, such as insufficient ground clearance, easy scratching of the road surface and obstacles, can be effectively avoided, the protection beam height can be actively adjusted downward when the truck is empty and the body is lifted, the rear protection ground clearance is always maintained within the safety standard range, the truck tail driving safety is improved, the protection height can be dynamically adjusted according to the load change and the road conditions, and the protection height is suitable for various scenes, such as the empty truck, the fully loaded truck and the bumpy road.

Description

Technical Field

[0001] This invention relates to the field of vehicle bumpers, and more specifically to a truck and a truck rear protection device. Background Technology

[0002] With the rapid development of China's road freight industry, medium and heavy-duty trucks have become the core carriers of land logistics transportation, and their ownership continues to rise. Trucks generally feature large ground clearance, large weight and size, and strong body structure, while passenger cars and small commuter vehicles have low profiles and weak collision protection structures. Traffic accidents involving small vehicles rear-ending trucks are frequent. Because trucks lack effective protective structures at the rear, small vehicles can easily run directly under the truck chassis, causing front-end crushing and damage, and even serious accidents resulting in injuries or fatalities to drivers and passengers, posing a significant road safety hazard.

[0003] Chinese utility model patent CN209534976U discloses a rear protective device for a truck, including a connecting plate and a rear guard bar. One end of the connecting plate is welded to the rear guard bar, and the other end is bolted to the truck's longitudinal beam. There are two connecting plates, one on each side of the rear of the truck. A stop plate with an L-shaped cross-section is provided at the rear end of the truck's longitudinal beam. The stop plate is in close contact with the bottom and rear end faces of the truck's longitudinal beam, and its side is welded to the connecting plate. A reinforcing rib plate is also provided. The top surface of the reinforcing rib plate is welded to the edge of the stop plate, the bottom surface is welded to the edge of the rear guard bar, and the side is welded to the connecting plate.

[0004] The above has the following defects: the ground clearance of the rear guard bar is fixed. When the truck is fully loaded, the vehicle body sinks and the ground clearance decreases. The protective device is prone to scraping the road surface, roadbed or bumpy obstacles, causing structural deformation and damage. When the truck is unloaded, the ground clearance is too large, which cannot meet the protection height requirements. It is difficult to effectively prevent small vehicles from rear-ending and going under the chassis, and the risk of protection failure is extremely high. Summary of the Invention

[0005] The purpose of this invention is to overcome the above-mentioned technical deficiencies and propose a truck and a truck rear protection device to solve the technical problem that the ground clearance of the rear guard bar in the prior art cannot be flexibly adjusted according to the vehicle body status.

[0006] In a first aspect, the technical solution of the present invention provides a rear protection device for a truck, including a bracket, wherein the bracket is provided with a guide groove; The protective beam is slidably connected to the bracket; and, The lifting mechanism includes a power component and a guide rod. The guide rod is slidably connected to the guide groove and connected to the protective beam. The power component is mounted on the bracket, and the output shaft of the power component is connected to the guide rod to adjust the ground clearance of the protective beam. The ground clearance of the protective beam is adjustable in the range of 300mm-500mm.

[0007] In some embodiments, the lifting mechanism further includes a reinforcing beam, one end of which is slidably connected to the bracket, and the other end of which is connected to the protective beam.

[0008] In some embodiments, the lifting mechanism further includes a plurality of ball heads, a plurality of ball sleeves, and an elastic interlayer. The plurality of ball heads are respectively connected to the guide rod and the output shaft of the power component. The plurality of ball sleeves are all connected to the protective beam. The ball heads are hinged to the ball sleeves. The elastic interlayer is connected to the inner wall of the ball sleeves and abuts against the outer wall of the ball heads.

[0009] In some embodiments, the protective device further includes a buffer mechanism comprising a buffer plate and an elastic pad, the buffer plate being connected to the protective beam and the elastic pad being connected to the buffer plate.

[0010] In some embodiments, the buffer mechanism further includes a honeycomb core and a plurality of buffer bumps, the elastic pad is provided with a plurality of pressure relief holes, the plurality of pressure relief holes and the plurality of buffer bumps are spaced apart and connected to the elastic pad, and the honeycomb core is connected to the buffer plate.

[0011] In some embodiments, the buffer mechanism further includes an energy-absorbing column, a buffer sleeve, and a limiting cylinder. The energy-absorbing column is connected to the buffer plate, the limiting cylinder is connected to the protective beam, the energy-absorbing column is slidably connected inside the limiting cylinder, the buffer sleeve is connected to the outside of the energy-absorbing column, the buffer sleeve abuts against the inner wall of the limiting cylinder, and the buffer sleeve and the limiting cylinder are interference-fitted.

[0012] In some embodiments, the energy-absorbing column is provided with a plurality of collapse grooves, which extend along the axial direction of the energy-absorbing column to cause the energy-absorbing column to collapse along its own axial direction.

[0013] In some embodiments, the energy-absorbing column includes multiple columns connected end to end in sequence, and the energy-absorbing column as a whole is corrugated so that the energy-absorbing column collapses in stages.

[0014] In some embodiments, the buffer mechanism further includes a plurality of buffer protrusions, which are spaced apart along the axial direction of the limiting cylinder and connected to the inner wall of the limiting cylinder. The spacing between adjacent buffer protrusions gradually decreases from the outer side of the limiting cylinder to the inner side of the limiting cylinder, and the inner diameter of the buffer protrusion is smaller than the outer diameter of the energy-absorbing column.

[0015] Secondly, this application provides a truck equipped with a rear protective device.

[0016] Compared with existing technologies, the beneficial effects of this invention include: actively raising the protective beam when the truck is fully loaded and its body is lowered, effectively avoiding the shortcomings of traditional fixed protective structures such as insufficient ground clearance and easy scraping of the road surface and obstacles; actively lowering the height of the protective beam when the truck is unloaded and its body is raised, ensuring that the ground clearance of the rear protection is always maintained within the safe standard range, thus improving the driving safety of the truck's rear. The protective height can be dynamically adjusted according to changes in load and road conditions, adapting to various operating scenarios such as unloaded, fully loaded, bumpy roads, and trailer docking, overcoming the shortcomings of traditional fixed rear protection devices that have limited functionality and poor adaptability to different working conditions. Attached Figure Description

[0017] Figure 1 This is a first-view overall structural schematic diagram of the protective device provided by the present invention; Figure 2 This is a second-view overall structural diagram of the protective device provided by the present invention; Figure 3 This is a cross-sectional view of the overall structure of the protective device provided by the present invention; Figure 4 This invention provides Figure 3 Enlarged view of the local structure at point A in the middle.

[0018] Explanation of reference numerals in the attached figures: 1. Bracket; 3. Protective beam; 4. Lifting mechanism; 41. Power component; 42. Guide rod; 43. Guide groove; 44. Reinforcing beam; 45. Ball head; 46. Ball sleeve; 47. Elastic interlayer; 5. Buffer mechanism; 51. Buffer plate; 52. Elastic pad; 53. Honeycomb core; 54. Buffer protrusion; 55. Pressure relief hole; 6. Energy-absorbing column; 61. Buffer sleeve; 62. Limiting cylinder; 63. Collapse groove; 64. Column; 65. Buffer protrusion ring. Detailed Implementation

[0019] To make the objectives, technical solutions, and advantages of this invention clearer, the invention will be further described in detail below with reference to the accompanying drawings and embodiments. It should be understood that the specific embodiments described herein are merely illustrative and not intended to limit the invention.

[0020] This invention provides a rear protective device for trucks, the structure of which is as follows: Figure 1 - Figure 4 As shown, it includes a support frame 1, a protective beam 3, and a lifting mechanism 4.

[0021] The bracket 1 is provided with a guide groove 43.

[0022] The protective beam 3 is slidably connected to the bracket 1.

[0023] The lifting mechanism 4 includes a power component 41 and a guide rod 42. The guide rod 42 is slidably connected to the guide groove 43 and connected to the protective beam 3. The power component 41 is mounted on the bracket 1, and the output shaft of the power component 41 is connected to the guide rod 42 to adjust the ground clearance of the protective beam 3. The ground clearance adjustment range of the protective beam 3 is 300mm-500mm.

[0024] In use, when the truck is fully loaded, the suspension is compressed and the ground clearance is reduced, the power component 41 drives the guide rod 42 upward, raising the protective beam 3 as a whole. This actively increases the ground clearance of the protective beam 3, preventing it from scraping the road surface, bumps, obstacles, or roadbed due to excessive height, and preventing the protective structure from being squeezed, deformed, or broken. When the truck is unloaded, the body is raised, and the ground clearance is increased, the power component 41 drives the guide rod 42 downward, lowering the protective beam 3 to the standard protection height, reducing the rear protection clearance. This prevents small vehicles from rear-ending and going under the truck chassis due to excessively high protection positions, ensuring that the rear protection height always meets safety requirements. Simultaneously, the sliding guide cooperation between the guide rod 42 and the guide groove 43 ensures the stability and uniform force distribution of the protective beam 3 during lifting and lowering. The direct-drive structure of the power component 41 has high transmission efficiency and rapid response.

[0025] In accordance with the mandatory standards for underrun protection on trucks, the national standard requires that the lower edge of the protective device be no more than 500mm above the ground when unloaded. This device has an upper adjustment limit of 500mm, allowing it to be lowered to within this height when the truck is unloaded. This reliably prevents small vehicles from rear-ending and underrunning the truck chassis, meeting regulatory requirements. The lower adjustment limit is set at 300mm to accommodate situations where the truck is fully loaded or heavily loaded, causing significant vehicle sag. This allows the protective beam 3 to be raised to 300mm above the ground, providing sufficient clearance to prevent it from scraping against the road surface, potholes, speed bumps, and gravel obstacles when fully loaded. This also prevents deformation of the protective beam 3, weld cracking, and damage to the bracket 1, extending the device's lifespan and reducing maintenance and replacement costs.

[0026] In this invention, the protective beam 3 can be actively raised when the truck is fully loaded and its body is lowered, effectively avoiding the shortcomings of traditional fixed protective structures, such as insufficient ground clearance and easy scraping of the road surface and obstacles. Conversely, the height of the protective beam 3 can be actively lowered when the truck is unloaded and its body is raised, ensuring that the ground clearance of the rear protection is always maintained within the safe standard range, thus improving the driving safety of the truck's rear. The protective height can be dynamically adjusted according to changes in load and road conditions, adapting to various operating scenarios such as unloaded, fully loaded, bumpy roads, and trailer docking, overcoming the shortcomings of traditional fixed rear protection devices, which have limited functionality and poor adaptability to different working conditions.

[0027] To improve the stability of protective beam 3, please refer to... Figure 2In a preferred embodiment, the lifting mechanism 4 further includes a reinforcing beam 44, one end of which is slidably connected to the bracket 1, and the other end of which is connected to the protective beam 3.

[0028] In use, when a rear-end collision occurs, the protective beam 3 experiences a horizontal forward impact force. This load is simultaneously transmitted to both the guide rod 42 and the reinforcing beam 44, sharing the load. The reinforcing beam 44 can absorb most of the lateral and eccentric impact forces, preventing all the impact force from concentrating on a single guide rod 42 and preventing it from bending or deforming due to unilateral stress. During the lifting and adjustment process, the reinforcing beam 44 and the guide rod 42 slide vertically synchronously, forming multi-point constraints on both ends of the protective beam 3. This restricts the left and right deflection and front and back tilting of the protective beam 3, ensuring that the protective beam 3 maintains a horizontal posture throughout the lifting and lowering process, making the lifting and lowering of the protective beam 3 more stable and smooth. When the truck is fully loaded and traveling on bumpy roads, the vertical vibration load from the road surface is borne jointly by the reinforcing beam 44 and the guide rod 42, dispersing the fatigue stress at the connection between the support 1 and the guide rod 42. This reduces the risk of weld cracking of the support 1 and the guide rod 42, as well as accelerated wear of the sliding parts, improving the overall rigidity and vibration resistance of the entire lifting structure.

[0029] To reduce the possibility of damage to the power component 41 and guide rod 42, please refer to Figure 3 In a preferred embodiment, the lifting mechanism 4 further includes a plurality of ball heads 45, a plurality of ball sleeves 46, and an elastic interlayer 47. The plurality of ball heads 45 are respectively connected to the output shaft of the guide rod 42 and the power component 41. The plurality of ball sleeves 46 are all connected to the protective beam 3. The ball heads 45 are hinged to the ball sleeves 46. The elastic interlayer 47 is connected to the inner wall of the ball sleeves 46 and abuts against the outer wall of the ball heads 45. The elastic interlayer 47 is made of polyurethane.

[0030] During use, when the protective beam 3 is vertically raised and lowered, there are slight assembly tolerances and sliding friction deviations in the guide groove 43 and guide rod 42 of the bracket 1, which can easily cause slight lateral load, axial misalignment, and angular offset. This structure utilizes the adaptive rotation and fine-tuning swing of the ball head 45 within the ball sleeve 46 to automatically compensate for the assembly and sliding deviations generated during the raising and lowering process, ensuring smooth raising and lowering of the protective beam 3. The elastic interlayer 47 set on the inner wall of the ball sleeve 46 is tightly fitted to the outer wall of the ball head 45, forming an elastic pre-tightening covering structure. During normal raising and lowering adjustment, the elastic interlayer 47 eliminates the fit gap between the ball head 45 and the ball sleeve 46 through its own elastic deformation, suppressing swaying and looseness, and ensuring the accuracy of raising and lowering adjustment and structural stability. When a vehicle is involved in a rear-end collision or road bumps and vibrations, the elastic interlayer 47 can flexibly buffer and absorb the impact force and vibration load, weaken the rigid impact transmission, and avoid stress concentration at the hinge point of the ball head 45, effectively protecting the output shaft of the power component 41, the guide rod 42, and the hinge structure from deformation and breakage. Meanwhile, the combination of multiple sets of ball joints with 450,000-way hinges and multiple points of elastic buffer covering allows the protective beam 3 to adaptively adjust its angle when subjected to eccentric impacts or oblique impacts, avoiding local stress concentration that could lead to structural distortion and damage, and significantly improving the overall lifting structure's impact resistance, smooth operation, and structural durability.

[0031] To achieve a buffering effect, please refer to... Figure 2 In a preferred embodiment, the protective device further includes a buffer mechanism 5, which includes a buffer plate 51 and an elastic pad 52. The buffer plate 51 is connected to the protective beam 3, and the elastic pad 52 is connected to the buffer plate 51. The elastic pad 52 is made of EPDM rubber.

[0032] In use, when a rear-end collision occurs, the external force first acts on the elastic pad 52. The elastic pad 52, relying on its own elastic material, undergoes compression deformation, initially dissipating the kinetic energy of the low-speed, minor impact, reducing the direct rigid impact, and minimizing the damage to the front of the rear-end vehicle. The impact force is further transmitted to the rear buffer plate 51, which bears the remaining impact load and distributes it evenly across the entire area of ​​the protective beam 3, preventing the impact stress from concentrating at localized points on the protective beam 3, causing dents or cracks. In addition, when the truck travels over potholes and speed bumps, generating continuous bumps and vibrations, the elastic pad 52 can isolate the impact from gravel and debris behind, weakening the transmission of vibration to the protective beam 3 and the lifting mechanism 4, and reducing fatigue wear on sliding and transmission components such as the bracket 1, guide rod 42, and power component 41.

[0033] To improve buffering performance, please refer to... Figure 3 In a preferred embodiment, the buffer mechanism 5 further includes a honeycomb core 53 and a plurality of buffer bumps 54. The elastic pad 52 is provided with a plurality of pressure relief holes 55. The plurality of pressure relief holes 55 and the plurality of buffer bumps 54 are spaced apart and connected to the elastic pad 52. The honeycomb core 53 is connected to the buffer plate 51.

[0034] When in use, if a minor scrape or low-speed rear-end collision occurs, the impact force first acts on the buffer protrusion 54 on the outer side of the elastic pad 52. The buffer protrusion 54 is compressed first, and consumes a small amount of impact kinetic energy by using its own elastic deformation. The pressure relief holes 55 on the surface of the elastic pad 52 contract synchronously and release pressure during the compression of the protrusion, avoiding the accumulation of air pressure inside the elastic pad 52 to form a reverse hard impact. The buffering process is gentle and without rebound, reducing the damage to the front of small vehicles from scrapes. When the impact force increases, after the buffer protrusion 54 and the elastic pad 52 are fully compressed, the impact force is transmitted inward to the honeycomb core 53. The honeycomb core 53 is fixed between the buffer plate 51 and the elastic pad 52, and the honeycomb holes inside the honeycomb core 53 extend through the front and rear length direction of the truck. The impact load acts along the axial direction of the honeycomb holes, and the thin wall of the honeycomb holes undergoes orderly plastic collapse deformation, dissipating the medium impact kinetic energy over a large area, dispersing the impact load, and preventing the impact force from being directly and concentratedly transmitted to the rear protective beam 3 and the lifting mechanism 4, and preventing stress overload deformation at the hinge position of the guide rod 42 and the ball head 45.

[0035] To further improve the buffering effect, please refer to Figure 4 In a preferred embodiment, the buffer mechanism 5 further includes an energy-absorbing column 6, a buffer sleeve 61, and a limiting cylinder 62. The energy-absorbing column 6 is connected to the buffer plate 51, the limiting cylinder 62 is connected to the protective beam 3, the energy-absorbing column 6 is slidably connected inside the limiting cylinder 62, the buffer sleeve 61 is connected to the outside of the energy-absorbing column 6, the buffer sleeve 61 abuts against the inner wall of the limiting cylinder 62, and the buffer sleeve 61 and the limiting cylinder 62 are interference-fitted.

[0036] In use, during a rear-end collision, the impact force is transmitted to the buffer plate 51 via the elastic pad 52 and honeycomb core 53. The buffer plate 51 drives the energy-absorbing column 6 to slide axially towards the rear of the vehicle, and the energy-absorbing column 6 is simultaneously compressed and extended into the limiting cylinder 62. Due to the interference fit between the buffer sleeve 61 and the inner wall of the limiting cylinder 62, the buffer sleeve 61 is continuously compressed and deformed during the sliding of the energy-absorbing column 6. The outer wall of the buffer sleeve 61 and the inner wall of the limiting cylinder 62 generate continuous sliding friction, which consumes a large amount of impact kinetic energy through frictional resistance, forming a second-stage damping energy absorption link. The limiting cylinder 62 provides full-circumferential radial constraint on the energy-absorbing column 6, limiting the energy-absorbing column 6 to slide only in a straight line along the front and rear impact direction of the truck, preventing the energy-absorbing column 6 from tilting due to eccentric impact, ensuring that all impact force is dissipated axially, and no lateral ineffective component force is generated. When the impact stroke reaches its limit, the tail of the energy-absorbing column 6 abuts against the bottom of the limiting cylinder 62 to form a rigid limit, preventing the buffer plate 51 from moving excessively backward and impacting the protective beam 3 and damaging the rear lifting mechanism 4. The small, reciprocating impacts caused by road bumps during truck operation will drive the energy-absorbing column 6 to slide back and forth slightly within the limiting cylinder 62. The buffer sleeve 61 continuously dissipates vibration energy through friction, weakening the transmission of vibration to the protective beam 3, bracket 1, and power component 41, and reducing fatigue wear of the lifting sliding components and the ball head 45 hinge structure. The interference fit structure of the buffer sleeve 61 can eliminate the assembly gap between the energy-absorbing column 6 and the limiting cylinder 62, so there is no metal shaking or abnormal noise during operation. At the same time, the buffer sleeve 61 itself provides elastic cushioning to prevent the energy-absorbing column 6 from hard-contact wear with the inner wall of the limiting cylinder 62.

[0037] To limit the collapse direction of the energy-absorbing column 6, please refer to... Figure 4 In a preferred embodiment, the energy-absorbing column 6 is provided with a plurality of collapse grooves 63, which extend along the axial direction of the energy-absorbing column 6 so that the energy-absorbing column 6 collapses along its own axial direction.

[0038] In use, when the rear-end collision impact load is transmitted to the energy-absorbing column 6 through the buffer plate 51, the energy-absorbing column 6 slides backward along the axis within the limiting cylinder 62. After the load exceeds the bearing limit of the friction damping of the buffer sleeve 61, the energy-absorbing column 6 is subjected to the reverse support force at the bottom of the limiting cylinder 62, and the column body 64 generates axial compressive stress. Since the cross-sectional strength of the cylinder wall at the location of the collapse groove 63 is lower, the energy-absorbing column 6 will not bend or twisted irregularly. It can only fold inward in an orderly manner and collapse axially along the preset weak position of the collapse groove 63, continuously consuming the kinetic energy of the high-intensity impact through metal plastic deformation. The crumple groove 63 is arranged along the axial direction of the energy-absorbing column 6, which is consistent with the direction of the impact force of the vehicle at the front and rear. This ensures that the crumple deformation is carried out along the axis of the energy-absorbing column 6 throughout the entire process, without lateral deviation. In conjunction with the radial constraint of the limiting cylinder 62, it further prevents the energy-absorbing column 6 from jamming and failing. At the same time, the multiple circumferential crumple grooves 63 evenly distribute the compressive stress, making the crumple process of the energy-absorbing column 6 smooth and the energy absorption stable. This avoids the instantaneous change in impact force being transmitted to the rear protective beam 3 and the lifting mechanism 4, and provides protection for the bracket 1, the power component 41, and the hinged structure of the ball head 45.

[0039] To achieve the gradual collapse of the energy-absorbing column 6, please refer to... Figure 4 In a preferred embodiment, the energy-absorbing column 6 includes a plurality of columns 64 connected end to end in sequence, and the energy-absorbing column 6 is corrugated as a whole, so that the energy-absorbing column 6 collapses in stages.

[0040] In use, the impact force generated by the rear-end collision is transmitted to the front end of the energy-absorbing column 6 through the buffer plate 51. The energy-absorbing column 6 slides axially backward within the limiting cylinder 62. The buffer sleeve 61 first consumes the initial impact energy through interference friction. As the load continues to increase, the corrugated first column 64 is first compressed and folded, dissipating the moderate impact kinetic energy through the plastic deformation of this section of metal. If the impact energy is further increased, after the first corrugated section is completely compacted, the pressure is automatically transmitted to the next column 64, and the second corrugated section collapses and deforms accordingly, thus achieving segmented and progressive collapse. The corrugated segmented structure divides the overall energy absorption stroke into multiple independent deformation intervals. The greater the impact force, the more corrugated segments participate in the collapse. The buffer resistance increases continuously with the compression stroke, and there will be no instantaneous impact peak. At the same time, the corrugated structure is arranged along the impact axis. With the radial constraint of the limiting cylinder 62, all columns 64 are folded neatly only in the front and rear direction of the truck, and there will be no lateral twisting, skew, or jamming. All impact kinetic energy is dissipated in an orderly manner along the axis, avoiding stress concentration impacting the rear protective beam 3, lifting mechanism 4, and hinged components.

[0041] To achieve a gradual increase in buffer resistance, please refer to... Figure 4 In a preferred embodiment, the buffer mechanism 5 further includes a plurality of buffer protrusions 65, which are connected at intervals along the axial direction of the limiting cylinder 62 to the inner wall of the limiting cylinder 62. The spacing between adjacent buffer protrusions 65 gradually decreases from the outer side of the limiting cylinder 62 to the inner side of the limiting cylinder 62, and the inner diameter of the buffer protrusions 65 is smaller than the outer diameter of the energy-absorbing column 6.

[0042] In use, the inner wall of the limiting cylinder 62 is axially spaced with multiple buffer convex rings 65, and the spacing between adjacent buffer convex rings 65 gradually decreases and the density gradually increases from the outer impact end to the inner support end. Simultaneously, the inner diameter of the buffer convex rings 65 is smaller than the outer diameter of the energy-absorbing column 6, ensuring that the energy-absorbing column 6 maintains an interference fit with the buffer convex rings 65 throughout its sliding motion within the limiting cylinder 62. When a rear-end collision occurs and the energy-absorbing column 6 slides inward along the axial direction of the limiting cylinder 62, the outer wall of the energy-absorbing column 6 sequentially presses against and scrapes against each buffer convex ring 65, continuously generating frictional damping to dissipate kinetic energy through the elastic deformation of the convex rings. Because the inner buffer convex rings 65 are more densely arranged, the more the energy-absorbing column 6 collapses inward, the more convex rings come into contact with and are compressed per unit stroke, resulting in greater superimposed compression resistance and a continuous, gradual increase in overall frictional damping force with the impact stroke. In the initial stage of impact, the short travel distance and small number of contacting convex rings result in low buffering resistance, achieving flexible buffering for minor impacts and avoiding instantaneous hard impacts. As the impact depth increases, the buffer convex rings 65 in the high-density area gradually participate in the compression and energy dissipation, and the damping resistance continues to increase. Combined with the progressive plastic collapse of the corrugated multi-stage column 64, a dual progressive energy absorption effect is formed.

[0043] This application also discloses a truck equipped with a truck rear protection device.

[0044] To better understand this invention, the following is combined with... Figure 1 - Figure 4 The working principle of a truck rear protection device according to the present invention is described in detail as follows: When the truck is fully loaded, the vehicle suspension is compressed and sinks, and the ground clearance of the chassis decreases, the guide rod 42 can be driven upward by the power component 41, which drives the protective beam 3 to rise as a whole, actively increasing the ground clearance of the protective beam 3, preventing the protective beam 3 from scraping the road surface, bumps, obstacles, or roadbed due to being too low, and preventing the protective structure from being squeezed, deformed, broken, or damaged. When the truck is unloaded, the vehicle body is raised, and the ground clearance of the chassis increases, the guide rod 42 can be driven downward by the power component 41, which drives the protective beam 3 to descend to the standard protection height, reducing the rear protection clearance and preventing small vehicles from rear-ending and going under the truck chassis due to the protection position being too high, ensuring that the rear protection height always meets the safety protection requirements. At the same time, the sliding guide cooperation between the guide rod 42 and the guide groove 43 can ensure the stability of the protective beam 3 during the lifting process and the uniform force distribution. The direct drive structure of the power component 41 has high transmission efficiency and fast response.

[0045] In accordance with the mandatory standards for underrun protection on trucks, the national standard requires that the lower edge of the protective device be no more than 500mm above the ground when unloaded. This device has an upper adjustment limit of 500mm, allowing it to be lowered to within this height when the truck is unloaded. This reliably prevents small vehicles from rear-ending and underrunning the truck chassis, meeting regulatory requirements. The lower adjustment limit is set at 300mm to accommodate situations where the truck is fully loaded or heavily loaded, causing significant vehicle sag. This allows the protective beam 3 to be raised to 300mm above the ground, providing sufficient clearance to prevent it from scraping against the road surface, potholes, speed bumps, and gravel obstacles when fully loaded. This also prevents deformation of the protective beam 3, weld cracking, and damage to the bracket 1, extending the device's lifespan and reducing maintenance and replacement costs.

[0046] The specific embodiments of the present invention described above do not constitute a limitation on the scope of protection of the present invention. Any other corresponding changes and modifications made in accordance with the technical concept of the present invention should be included within the scope of protection of the claims of the present invention.

Claims

1. A rear protective device for trucks, characterized in that, include: The bracket is provided with guide grooves; The protective beam is slidably connected to the bracket; and, The lifting mechanism includes a power component and a guide rod. The guide rod is slidably connected to the guide groove and connected to the protective beam. The power component is mounted on the bracket, and the output shaft of the power component is connected to the guide rod to adjust the ground clearance of the protective beam. The ground clearance of the protective beam is adjustable in the range of 300mm-500mm.

2. The truck rear protection device according to claim 1, characterized in that, The lifting mechanism also includes a reinforcing beam, one end of which is slidably connected to the bracket, and the other end of which is connected to the protective beam.

3. The truck rear protection device according to claim 1, characterized in that, The lifting mechanism also includes multiple ball heads, multiple ball sleeves, and an elastic interlayer. The multiple ball heads are respectively connected to the guide rod and the output shaft of the power component. The multiple ball sleeves are all connected to the protective beam. The ball heads are hinged to the ball sleeves. The elastic interlayer is connected to the inner wall of the ball sleeves and abuts against the outer wall of the ball heads.

4. The truck rear protection device according to claim 1, characterized in that, The protective device further includes a buffer mechanism, which includes a buffer plate and an elastic pad. The buffer plate is connected to the protective beam, and the elastic pad is connected to the buffer plate.

5. The truck rear protection device according to claim 5, characterized in that, The buffer mechanism further includes a honeycomb core and multiple buffer bumps. The elastic pad is provided with multiple pressure relief holes, and the multiple pressure relief holes and multiple buffer bumps are connected to the elastic pad at intervals. The honeycomb core is connected to the buffer plate.

6. The truck rear protection device according to claim 5, characterized in that, The buffer mechanism further includes an energy-absorbing column, a buffer sleeve, and a limiting cylinder. The energy-absorbing column is connected to the buffer plate, the limiting cylinder is connected to the protective beam, the energy-absorbing column is slidably connected inside the limiting cylinder, the buffer sleeve is connected to the outside of the energy-absorbing column, the buffer sleeve abuts against the inner wall of the limiting cylinder, and the buffer sleeve and the limiting cylinder are interference-fitted.

7. The truck rear protection device according to claim 7, characterized in that, The energy-absorbing column is provided with a plurality of collapse grooves, which extend along the axial direction of the energy-absorbing column so that the energy-absorbing column collapses along its own axial direction.

8. The truck rear protection device according to claim 7, characterized in that, The energy-absorbing column comprises multiple columns connected end to end in sequence. The energy-absorbing column as a whole is corrugated so that the energy-absorbing column collapses in stages.

9. The truck rear protection device according to claim 7, characterized in that, The buffer mechanism further includes multiple buffer protrusions, which are connected to the inner wall of the limiting cylinder at intervals along the axial direction of the limiting cylinder. The distance between adjacent buffer protrusions gradually decreases from the outer side of the limiting cylinder to the inner side of the limiting cylinder, and the inner diameter of the buffer protrusion is smaller than the outer diameter of the energy-absorbing column.

10. A truck, characterized in that, The truck is equipped with the rear protective device as described in any one of claims 1-9.

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