A crush energy absorbing steering column structure and method

Abstract

The application relates to the technical field of automobile steering columns, and discloses a collapse energy-absorbing steering column structure and method, which comprises an upper column, the lower end of the upper column extends into a lower column to realize connection with the lower column, an upper shaft is arranged in the upper column, a lower shaft is arranged in the lower column, and the upper shaft and the lower shaft are fixedly connected; a protrusion is arranged at the upper end of the lower column, a cavity is formed between the inner side of the protrusion and the outer wall of the upper column; a buckling plate is arranged on the outer wall of the upper column at the cavity, a pasting plate is arranged on the outer side of the buckling plate, a rivet extends to the through hole of the upper column after penetrating through the pasting plate and the buckling plate; a long circular hole is arranged on the buckling plate, a sliding groove is arranged on the protrusion, the outer side of the pasting plate is slidingly matched with a stop block, and a collapse screw extends to the long circular hole after penetrating through the stop block and the pasting plate; the stop block and the sliding groove are in the same plane; the application does not adopt a conventional pull-off block structure, the design can reduce the production of a pull-off block single piece and related nylon injection equipment and processes, save costs, and simplify the manufacturing process.

Description

Technical Field

[0001] This invention relates to the field of automotive steering column technology, and in particular to a collapsible energy-absorbing steering column structure and method. Background Technology

[0002] In the field of automotive steering systems, the manually adjustable four-way steering column has become a core component of mainstream passenger and commercial vehicle steering systems because it can meet the personalized driving posture needs of different drivers, improving driving comfort and ease of operation. Its core functions include not only adjusting the steering column in four directions (up, down, forward, and backward), but more importantly, absorbing collision energy through its own structural crumple zone deformation in the event of a collision. This prevents the steering column from directly impacting the driver due to excessive rigidity, thus ensuring the safety of occupants. Therefore, crumple zone energy absorption performance is one of the core indicators for evaluating the design rationality of a manually adjustable four-way steering column. Currently, most manual four-way adjustable steering columns in the industry adopt a composite structure of "aluminum on top and steel on the bottom" in their main structural design. This means the upper structure of the steering column is made of aluminum alloy, while the lower structure is made of steel. The initial intention of this design was to reduce the overall weight of the steering column by leveraging the lightweight properties of aluminum alloy, while ensuring overall structural strength, thus meeting the current automotive industry's demand for lightweight vehicles. To achieve the crumple zone energy absorption requirement during a collision, existing designs typically employ a combination of stacked mounting brackets and corresponding energy-absorbing components. Specifically, a pull-out block is installed at the upper mounting bracket of the steering column, usually connected and fixed to the upper mounting bracket via a molded pin. Simultaneously, a pull-out band is installed between the upper and lower structures, utilizing the interference fit between them to collectively construct the steering column's crumple zone energy absorption system. During a collision, the impact force acts on the steering column, first causing the molded pin to break, separating the pull-out block from the upper mounting bracket. Subsequently, the pull-out band gradually stretches or breaks under the impact force. Combined with the gradual release of the interference fit between the upper and lower structures, this achieves crumple zone deformation of the entire steering column, thereby absorbing the collision energy. However, the aforementioned traditional manual four-way adjustable steering column design involves multiple complex technological steps, including the stacking and combination of mounting brackets, the injection-molded pin connection between the pull-out block and the upper mounting bracket, the assembly of the pull-out band, and the control of the interference fit between the upper and lower structures. This not only leads to cumbersome production processes and increases manufacturing difficulty but also raises quality control costs during production, hindering large-scale and efficient production. Furthermore, because the design relies on the pull-out block to initiate the crumple zone energy absorption process, in a real-world collision, the pull-out block separates from the upper mounting bracket and becomes an independent, scattered component. This can not only cause additional impact or interference to other components around the steering system but, more importantly, the detachment of the pull-out block can damage the original structural integrity of the steering column, leading to a significant decrease in structural stability during subsequent crumple. This lack of structural stability can easily cause problems such as the crumple path deviating from the preset trajectory, excessive fluctuations in crumple force, or the crumple stroke failing to meet design requirements. This directly affects the actual performance of the steering column in crumple zone energy absorption, making it difficult to reliably and stably ensure the safety of occupants in collision accidents and failing to meet the ever-increasing demands for automotive safety performance. Therefore, how to optimize the structural design of the manual four-way adjustable steering column, simplify the process and reduce manufacturing costs, while improving the structural stability during the collision process and ensuring the reliability of the crumple zone energy absorption performance, has become a key technical problem that needs to be solved by those skilled in the art. Summary of the Invention

[0003] In view of the shortcomings of the existing technology, the purpose of this invention is to provide a collapsible energy-absorbing steering column structure and method, which does not adopt the conventional pull-out block structure. This design can reduce the production of individual pull-out blocks and the related equipment and processes for nylon injection molding, thereby saving costs and simplifying the manufacturing process.

[0004] To achieve the above objectives, the present invention is implemented through the following technical solution: Firstly, a collapsible energy-absorbing steering column structure includes an upper column, the lower end of which extends into a lower column for connection. An upper mandrel is located inside the upper column, and a lower mandrel is located inside the lower column; the upper and lower mandrels are fixedly connected. A protrusion is located at the upper end of the lower column, forming a cavity between the inner side of the protrusion and the outer wall of the upper column. A snap-on plate is located on the outer wall of the upper column at the cavity, and a mounting plate is located on the outer side of the snap-on plate. One end of a rivet passes through the mounting plate and the snap-on plate and extends to a through hole in the upper column. An elongated hole is located on the snap-on plate, and a groove is located on the protrusion. A stop block is slidably fitted on the outer side of the mounting plate, and one end of a collapsible screw passes through the stop block and the mounting plate and extends to the elongated hole. The stop block and the groove are on the same plane.

[0005] As a further implementation, the lower tube column is provided with flat plates on both sides of the upper end. The flat plates cooperate with the bracket, which is equipped with an adjustment handle. After the adjustment handle is locked, the lower tube column hugs the upper tube column.

[0006] As a further implementation, the stop block can slide within the groove, and the stop block has a set distance from the inner wall of the groove.

[0007] As a further implementation, the buckle plate is a U-shaped plate that is fastened to the outer wall of the upper column. An elongated hole is provided on the top plate of the buckle plate, and the length direction of the elongated hole is in the same direction as the length direction of the upper column.

[0008] As a further implementation, the plate is a rectangular plate structure with rivet mating holes at both ends for one end of the rivet to pass through. The rivet mating holes and the corresponding through holes are arranged coaxially.

[0009] As a further implementation, the chute is a rectangular chute, which is opened on the raised top plate, and the length direction of the chute is in the same direction as the length direction of the lower pipe column; the width of the stop block is adapted to the width of the chute.

[0010] As a further implementation, the size of the plate is larger than the size of the groove.

[0011] As a further implementation, the mounting plate is located inside the raised top plate; the mounting plate has a through hole for the rivet to pass through; the top of the collapsible screw protrudes from the groove.

[0012] As a further implementation, the lower tube column is a cast aluminum part, and a connecting sleeve is provided on the lower tube column, with the connecting sleeve and the lower tube column being an integral structure.

[0013] Secondly, a method for operating a collapsible energy-absorbing steering column structure, characterized in that it employs any of the above-described collapsible energy-absorbing steering column structures, comprising the following steps: After the lower column clamps the upper column, the upper and lower columns achieve frictional engagement through holding force. When a vehicle collision occurs, if the impact energy of the driver's head exceeds the upper limit of the frictional force mainly based on holding force, the upper column collapses downward along the axis of the lower column. After the collapsible screw drives the stop block to complete its travel in the slide groove, the rivet is subjected to shear force. This is the peak force of the steering column collapse structure. After the peak point, the collapsible screw slides in the elongated hole, and the plate and the stop block slide together.

[0014] The beneficial effects of the present invention are as follows: 1. This invention uses a pull-out mechanism with buckles, plates, blocks, collapsible screws, and rivets inside the protrusion, instead of a conventional pull-out block structure. This design reduces the production of individual pull-out blocks and the related equipment and processes for nylon injection molding, saving costs and simplifying the manufacturing process. At the same time, the pull-out method of this invention maintains the position of the lower column tube when collapse occurs, resulting in good stability during the collapse process.

[0015] 2. The lower column tube of this invention is made of cast aluminum and is an integrally cast structure. The connecting sleeve structure is directly reflected on the casting, which can reduce the processing of existing lower mounting brackets and the welding process of brackets. Attached Figure Description

[0016] The accompanying drawings, which form part of this invention, are used to provide a further understanding of the invention. The illustrative embodiments of the invention and their descriptions are used to explain the invention and do not constitute an improper limitation of the invention.

[0017] Figure 1 This is a schematic diagram of the collapsible energy-absorbing steering column structure in an embodiment of the present invention; Figure 2 This is a schematic diagram of the cross-sectional structure of the collapsible energy-absorbing steering column in an embodiment of the present invention; Figure 3 This is a schematic diagram of the lower tubular column in an embodiment of the present invention; Figure 4 This is a schematic diagram of the upper tubular column in an embodiment of the present invention; Figure 5 This is a partial structural schematic diagram of the upper tubular column in an embodiment of the present invention; Figure 6 This is a schematic diagram of a partial structure of the collapsible energy-absorbing steering column in an embodiment of the present invention.

[0018] The diagram exaggerates the spacing or dimensions between parts to show their positions; the diagram is for illustrative purposes only.

[0019] Among them: 1. Upper mandrel, 2. Lower mandrel, 3. Upper tube post, 36. Through hole, 4. Lower tube post, 5. Support; 31. Snap-on plate; 311. Oblong hole; 32. Adhesive plate; 33. Rivet; 34. Collapsible screw; 35. Stop block; 41. Slide groove, 42. Connecting sleeve, 43. Flat plate, 44. Protrusion. Detailed Implementation

[0020] It should be noted that the following detailed description is illustrative and intended to provide further explanation of the invention. Unless otherwise specified, all technical and scientific terms used in this invention have the same meaning as commonly understood by one of ordinary skill in the art to which this invention pertains.

[0021] Example 1 In a typical embodiment of the present invention, reference is made to Figures 1-6As shown, a collapsible energy-absorbing steering column structure includes an upper column 3, the lower end of which extends into a lower column 4 for connection. An upper mandrel 1 is located inside the upper column 3, and a lower mandrel 2 is located inside the lower column 4. The upper mandrel 1 and lower mandrel 2 are fixedly connected. A protrusion 44 is located at the upper end of the lower column 4, forming a cavity between the inner side of the protrusion 44 and the outer wall of the upper column. A buckle plate 31 is located on the outer wall of the upper column 3 at the cavity. A patch plate 32 is located on the outer side of the buckle plate 31. One end of a rivet 33 passes through the patch plate 32 and the buckle plate 31 and extends to a through hole in the upper column 3. The buckle plate 31 has an elongated hole 311, and the protrusion 44 has a sliding groove 41. A stop block 35 slides on the outer side of the patch plate 32. One end of a collapsible screw 34 passes through the stop block 35 and the patch plate 32 and extends to the elongated hole 311. The stop block 35 and the sliding groove 41 are on the same plane.

[0022] Specifically, such as Figure 1 and Figure 2 As shown, the collapsible energy-absorbing steering column structure includes an upper mandrel 1, a lower mandrel 2, an upper column 3, a lower column 4, and a support 5.

[0023] like Figure 3 and Figure 4 As shown, the upper end of the lower tube column 4, which is close to the upper tube column 1, is provided with two flat plates 43 on both sides. The line connecting the center lines of the two flat plates is located on the outside of the lower tube column 4. The flat plates cooperate with the bracket, which is equipped with an adjustment handle. After the adjustment handle is locked, the lower tube column can hug the upper tube column, so that the upper and lower tube columns are in frictional fit, and the friction force serves as the holding force.

[0024] It is understandable that the bracket and adjusting handle are existing technologies. The friction fit between the upper and lower tubing columns is also existing technology. For example... Figure 2 As shown, the outer diameter of the upper tube column 1 is matched with the inner diameter of the lower tube column 4, achieving a friction fit between them. The upper mandrel 1 is mounted in the upper tube column 3 via bearings, and the lower mandrel 2 is mounted in the lower tube column 4 via bearings. The upper mandrel 1 and the lower mandrel 2 are keyed together. The upper mandrel 1 can drive the lower mandrel 2 to rotate synchronously.

[0025] like Figure 2 As shown, a cavity is formed between the inner side of the protrusion 44 and the outer wall of the upper column 1, and a pull-out structure is provided in the cavity.

[0026] The pull-out structure includes a snap plate 31, a mounting plate 32, a rivet 33, a collapsible screw 34, and a stop block 35. For example... Figure 2 and Figure 4 , Figure 5 As shown, the buckle plate is a U-shaped plate, which is fastened to the outer wall of the upper column 3. The elongated hole is located on the top plate of the buckle plate and in the middle position. The length direction of the elongated hole 311 is in the same direction as the length direction of the upper column.

[0027] The buckle plate has two through holes, with an elongated hole between them. The through holes are used for rivets to pass through. Two through holes 36 are also provided on the wall surface of the upper column 1 near the lower column 4. These two through holes 36 correspond one-to-one with the through holes on the buckle plate, making it easy for the lower end of the rivet to extend to the through hole position on the upper column 1.

[0028] like Figure 2 and Figure 4 As shown, the mounting plate is a rectangular plate structure, located on the outer side of the top plate of the buckle plate 31, and arranged parallel to the top plate. Through holes are provided at both ends of the mounting plate for the lower ends of rivets 33 to pass through. The through holes and corresponding through holes are arranged coaxially. The rivets engage with the through holes, and the lower ends of the rivets 33 pass through the through holes on the buckle plate, extending to the through hole of the upper column 1.

[0029] like Figure 2 , Figure 4 and Figure 5 As shown, the outer side of the plate 32 has a sliding stop, and the stop 35 has a rectangular cross-section. Figure 4 In the middle, a stop block 35 is located above the plate, and a hole is provided in the middle of the stop block 35. A threaded hole is provided on the plate 32, which is located between two through holes and near the lower end of the upper tube column. One end of the collapsible screw 34 passes through the hole on the stop block, and then, after engaging with the threaded hole on the plate 32, extends to the elongated hole.

[0030] like Figure 1 and Figure 2 As shown, a groove 41 is provided on the protrusion 44. The stop block and the groove are on the same plane. Specifically, the stop block is inside the groove and can slide within the groove 41. The groove 41 is a rectangular groove, which is opened on the top plate of the protrusion. The length direction of the groove 41 is the same as the length direction of the lower pipe column. The width of the stop block 35 is adapted to the width of the groove. In its natural state, the stop block 35 and the inner wall surface of the right end of the groove 41 have a set distance, such as... Figure 2 As shown.

[0031] In this embodiment, the size of the mounting plate is larger than the size of the sliding groove, so that the mounting plate is located below the raised top plate, that is, the mounting plate is located inside the raised top plate and can slide relative to the raised top plate. The top of the collapsible screw protrudes out of the sliding groove.

[0032] The lower tubular column is made of cast aluminum and has a connecting sleeve integrated with it. The upper tubular column is a steel structure; this embodiment uses a "lower aluminum, upper steel" structure. The mounting structure (connecting sleeve 42) on the lower cast aluminum component is directly machined onto the cast aluminum part, reducing the need for stamping and welding in traditional structures. The upper steel component does not use common pull-out structures such as "pull-out blocks" or "pull-out bands" for its support; instead, it uses a fixed mounting structure. The collapsible energy-absorbing structure of this invention, in addition to the sliding friction between the upper and lower parts, also utilizes rivets and grooves. The entire tubular column assembly reduces costs by minimizing investment in injection molding, stamping, and welding equipment while increasing crush stability.

[0033] like Figure 2 , Figures 4-6 As shown, when a high-speed car collides with a low-speed or stationary object, the high-speed car will experience a significant deceleration. According to Newton's laws, the driver will continue to move forward due to inertia.

[0034] Statistics show that for medium-sized sedans, the steering column collapsible energy-absorbing structure can absorb approximately 18% of the total energy from a secondary collision. Therefore, the collapsible performance and consistency of the steering column play a crucial role in passive safety restraint systems.

[0035] After the lower column clamps the upper column, the upper and lower columns achieve frictional engagement through holding force. When a vehicle collision occurs, if the impact energy of the driver's head exceeds the upper limit of the frictional force mainly based on holding force, the upper column collapses downward along the axis of the lower column. After the collapsible screw drives the stop block to complete its travel in the slide groove, the rivet is subjected to shear force. This is the peak force of the steering column collapse structure. After the peak point, the collapsible screw slides in the elongated hole, and the plate and the stop block slide together.

[0036] The structural design described in this invention optimizes both the structural design and manufacturing process of the steering column assembly, and improves the stability of the steering column assembly's collapsibility performance. This will be elaborated below: Regarding structural design and process optimization, as can be seen from the aforementioned structural design description and accompanying drawings, firstly, the bracket of this invention only serves the function of installation and fixation, therefore, it does not employ a conventional pull-out block structure. Thus, the individual pull-out blocks (usually cast aluminum parts, 2 pieces) and their associated nylon injection-molded pins (usually a total of 8) can be eliminated. This design reduces the production of individual pull-out blocks (cast aluminum parts, usually outsourced) and the related equipment and processes for nylon injection molding (connection between the pull-out blocks and the mounting bracket). Secondly, the lower column tube 4 is made of cast aluminum, forming a one-piece cast structure. The connecting sleeve 42 structure is directly reflected in the casting, which reduces the machining of existing lower mounting bracket parts and the welding process for bracket parts.

[0037] In this embodiment, when collapse occurs, the position of the lower tube remains unchanged, and the collapse process is relatively stable. The first stage is maintained by the holding force. After the adjustment handle is locked, the lower tube body hugs the lower tube body, and the friction between the two serves as the holding force. The second stage consists of the holding force plus the rivet shearing force. The second stage includes the collapse peak. The third stage consists of the continuous collapse holding force provided by the interference fit movement of the collapse screw in the groove of the slide block plus the clamping force of the upper and lower tube bodies.

[0038] Example 2 like Figures 1-6 As shown, a method for operating a collapsible energy-absorbing steering column structure, employing the collapsible energy-absorbing steering column structure as described in Example 1, includes the following steps: First, during normal operation, the holding force of the steering column assembly is achieved as follows: after the adjustment handle is locked, the lower column body will hug the upper column body, and the limit of the frictional force between the two sliding relative to each other is the holding force.

[0039] Secondly, when a full-vehicle collision occurs, after the secondary impact on the driver and the activation of the restraint system, the driver's head impacts the deployed airbag, which transmits the impact energy to the steering column assembly. When the steering column collapses, as described above, the lower column tube remains in position (maintaining its assembly with the instrument panel beam). Once the impact energy to the driver's head exceeds the upper limit of the frictional force, which is primarily based on the holding force, the upper column tube collapses downwards along the column axis. When the above... Figure 2 In the middle section, after the collapsible screw and stop block have exhausted their travel (typically about 30mm, adjustable as needed) in the lower tube column's slide groove, the stop block is blocked by the inner wall of the slide groove. This causes the stop block to exert a force on the plate through the collapsible screw. The direction of this force is opposite to the movement direction of the upper tube column 3. At this point, the rivet begins to bear force. If the impact energy of the head is large enough, the rivet will undergo shearing. By selecting the rivet specifications, the corresponding shearing force can be adjusted. This is the peak force of the collapsible structure of the steering tube column. After the peak point, the collapsible screw and stop block can slide in the slide groove block, with the lower end of the collapsible screw sliding in the elongated hole. It can be understood that the stop block can be interference-fitted with the slide groove.

[0040] The above description is merely a preferred embodiment of the present invention and is not intended to limit the invention. Various modifications and variations can be made to the present invention by those skilled in the art. Any modifications, equivalent substitutions, improvements, etc., made within the spirit and principles of the present invention should be included within the scope of protection of the present invention.

Claims

1. A collapsible energy-absorbing steering column structure, characterized in that, The device includes an upper tube column, the lower end of which extends into a lower tube column for connection. An upper mandrel is located inside the upper tube column, and a lower mandrel is located inside the lower tube column; the upper and lower mandrels are fixedly connected. A protrusion is located at the upper end of the lower tube column, forming a cavity between the inner side of the protrusion and the outer wall of the upper tube column. A snap-on plate is located on the outer wall of the upper tube column at the cavity, and a mounting plate is located on the outer side of the snap-on plate. One end of a rivet passes through the mounting plate and the snap-on plate and extends to a through hole in the upper tube column. An elongated hole is located on the snap-on plate, and a groove is located on the protrusion. One end of a collapsible screw passes through a stop block and the mounting plate and extends to the elongated hole. The stop block and the groove are on the same plane. The buckle plate is a U-shaped plate that is fastened to the outer wall of the upper column. An elongated hole is provided on the top plate of the buckle plate, and the length direction of the elongated hole is in the same direction as the length direction of the upper column. The lower column is a cast aluminum part, and a connecting sleeve is provided on the lower column. The connecting sleeve and the lower column are an integral structure. The stop block can slide within the groove, and there is a set distance between the stop block and the inner wall of the groove. After the collapsible screw has completed its stroke in the groove, the stop block is blocked by the inner wall of the groove. The stop block exerts a force on the plate through the collapsible screw, and the rivet is sheared under the force. After shearing, the collapsible screw slides in the elongated hole. The stop block has a hole in the middle, and the plate has a threaded hole. After the collapsible screw passes through the hole on the stop block, it cooperates with the threaded hole on the plate and extends to the elongated hole.

2. The collapsible energy-absorbing steering column structure according to claim 1, characterized in that, The lower tube column is provided with flat plates on both sides of its upper end. The flat plates cooperate with the bracket, which is equipped with an adjustment handle. After the adjustment handle is locked, the lower tube column hugs the upper tube column.

3. The collapsible energy-absorbing steering column structure according to claim 1, characterized in that, The plate is a rectangular plate structure with rivet mating holes at both ends for one end of the rivet to pass through. The rivet mating holes and the corresponding through holes are arranged coaxially.

4. The collapsible energy-absorbing steering column structure according to claim 1, characterized in that, The chute is a rectangular chute, which is opened on the raised top plate. The length direction of the chute is in the same direction as the length direction of the lower pipe column; the width of the stop block is adapted to the width of the chute.

5. The collapsible energy-absorbing steering column structure according to claim 4, characterized in that, The size of the plate is larger than the size of the groove.

6. The collapsible energy-absorbing steering column structure according to claim 5, characterized in that, The mounting plate is located inside the raised top plate; the mounting plate has a through hole for the rivet to pass through; the top of the collapsible screw protrudes from the groove.

7. A working method for a collapsible energy-absorbing steering column structure, characterized in that, The collapsible energy-absorbing steering column structure as described in claim 2 includes the following steps: When collapse occurs, the position of the lower tube remains unchanged; The first stage is maintained by the holding force. After the adjustment handle is locked, the lower tube column is held by the lower tube column. The upper and lower tube columns achieve frictional engagement through the holding force, and the friction between the two serves as the holding force. When a vehicle collision occurs, the impact energy to the driver's head exceeds the upper limit of the friction force, which is mainly based on the holding force. The upper column collapses downward along the axis of the lower column. After the collapse screw drives the stop block to complete its travel in the groove, the rivet is subjected to shearing force. This is the peak force of the steering column collapse structure. The second stage consists of holding force and rivet shear force, and includes the collapse peak. After the peak point, the collapsible screw slides in the elongated hole; The third stage consists of the interference fit movement of the collapsible screw in the groove and the clamping force of the upper and lower tubular bodies providing a continuous collapsible retention force.

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