Design method of automobile trailer hook

Abstract

The present invention discloses a design method for an automobile towing hook, which relates to the technical field of automobile parts. The design method for the automobile towing hook includes the following steps: S10. Construct a simulated connection structure; S20. The length of the effective connection section of the towing hook tube in the energy absorption box is X3; S30. X3 can take multiple values. After applying and unloading the load on the towing hook corresponding to each value, the residual deformation △d A and the residual angle α. If △d A ≤0.7 mm and α≤1.5°, it means that the value of X3 can meet the requirements of the towing strength; S40. Among the values of X3 that meet the towing strength, select the minimum value as the final value of X3, and then determine the aperture of the through hole. The design method for the towing hook tube provided by the present invention is convenient for users to operate while ensuring that the towing hook meets the towing strength.

Description

Technical Field

[0001] The invention relates to the technical field of automobile parts, and in particular to a design method for an automobile trailer hook. Background Art

[0002] The rear-mounted car trailer hook is a temporary towing device that can be connected through a tow rope and a tow bar. It is usually connected to the vehicle body structure by a threaded connection to ensure that the entire vehicle body is evenly stressed when towing. At the same time, the bumper skin needs to be opened. When the trailer hook is not in use, the hole is closed with a plug to ensure the integrity and aesthetics of the shape. The size and position of the opening must meet the styling requirements and ensure that there is an appropriate gap with the trailer hook to avoid interference or friction during use.

[0003] Usually when arranging a trailer hook, in order to ensure stability during towing, the trailer hook tube needs to be firmly connected to the vehicle body to ensure sufficient strength. The longer the X-direction length of the trailer hook tube connected to the vehicle body, the better the trailer hook can withstand the tensile pressure during towing. However, the longer the X-direction length of the trailer hook tube connected to the vehicle body means that the end of the trailer hook tube is farther away from the opening on the bumper skin, which makes it inconvenient for the user to screw the trailer hook into the trailer hook tube, causing inconvenience to the user's operation. Therefore, in order to ensure the towing strength of the trailer hook and the convenience of user operation, the X-direction dimensions of the main connecting components and gaps between the trailer hook and the bumper need to be reasonably designed. Summary of the invention

[0004] The main purpose of the invention is to propose a design method for a vehicle trailer hook, aiming to solve the technical problem of ensuring the traction strength of the trailer hook while facilitating user operation.

[0005] To achieve the above object, the design method of the automobile trailer hook proposed by the present invention comprises the following steps:

[0006] S10, constructing a simulated connection structure: the trailer hook tube can be fixed in the energy absorption box by a fixing structure, a through hole is opened on the bumper skin, one end of the trailer hook can extend into the trailer hook tube through the through hole and be connected to the trailer hook tube thread;

[0007] S20. In the X direction, the effective length of the energy absorption box is X1, the length of the fixed structure of the trailer hook tube is X2, the length of the effective connection section of the trailer hook tube in the energy absorption box is X3, and the length of the trailer hook tube is h; wherein, X2+X3<X1, and X3<h(1);

[0008] S30, on the basis of satisfying the relational expression (1) in step S20, X3 can take multiple values, each value corresponding to a connection state of the trailer hook tube in the energy absorption box, and the towing performance of the trailer hook in each connection state is analyzed to obtain the residual deformation Δd at the towing position of the trailer hook after the load is applied and unloadedA and the residual angle α, if Δd A ≤0.7mm, α≤1.5°, it means that the value of X3 can meet the demand of traction strength;

[0009] S40. Among the X3 values ​​that satisfy the traction strength, select the minimum value as the final value of X3 to determine the effective connection section of the trailer hook tube in the energy absorption box, and then determine the aperture of the through hole.

[0010] In one embodiment, in step S30, analyzing the traction performance of the trailer hook in each connection state includes the following steps:

[0011] S301. Mesh the trailer hook and related local components using finite element analysis software Hypermesh to establish a finite element model;

[0012] S302, applying a load to the towing position of the trailer hook;

[0013] S303, using the Abaqus solver to calculate and analyze the residual deformation of the center point A of the towing part of the towing hook and the residual deformation of the center point B of the end surface of the connecting end of the towing hook after the towing hook is loaded and unloaded, and the residual displacement Δd of point A is obtained from the post-processing software HyperView A and the residual displacement Δd at point B B , through Δd A and Δd B This results in a residual angle α.

[0014] In one embodiment, in step S301, the parts related to the trailer hook include: an energy absorption box, a bumper skin, a trailer hook tube, and a fixing structure for fixing the trailer hook tube.

[0015] In one embodiment, in step S302, the magnitude of the applied load F is: F=G M *g / 2, where G M It is the sum of the mass of the vehicle when it is unloaded and the maximum mass that the vehicle can load, and g is the acceleration due to gravity;

[0016] The directions of applied load F include: Direction 1, along the positive direction of the X-axis; Direction 2, in the XY plane, at an upward angle of 5° with the positive semi-axis of the X-axis; Direction 3, in the XY plane, at a downward angle of 5° with the positive semi-axis of the X-axis; Direction 4: in the XZ plane, at an angle of 25° to the left with the positive semi-axis of the X-axis; Direction 5, in the XZ plane, at an angle of 25° to the right with the positive semi-axis of the X-axis.

[0017] In one embodiment, in step S303, the residual angle α is calculated as follows: α=arctan(Δd A -Δd B) / D AB (2);

[0018] Among them, D AB is the distance between point A and point B.

[0019] In one embodiment, in step S301, the steps of establishing a finite element model for the trailer hook and related local components are as follows: the trailer hook and the trailer hook tube are solid models, which are simulated using HEX8 hexahedral solid units; the sheet metal around the trailer hook is modeled using PSHELL units, and the grid size is 3mm×3mm; the threaded connection between the trailer hook and the trailer hook tube is modeled using *Tie contact, the weld between the trailer hook tube and the energy absorption box is simulated using rigid units, and the electric welding between local sheet metal parts is simulated using cweld units.

[0020] In one embodiment, in step S30, when the applied load is along the positive direction of the X-axis, Δd A ≤0.7mm; when the direction of the applied load is in the XY plane, α≤1.5°; when the direction of the applied load is in the XZ plane, α≤0.2°.

[0021] In one implementation, in step S30, the value of X3 is determined in descending order.

[0022] In one embodiment, in step S40, the method for determining the aperture of the through hole is: after the X3 value is determined, CAE is used to superimpose the trailer hook position and state obtained under each load corresponding to the X3 value to form an envelope, and the maximum circumference of the envelope is obtained. The aperture of the through hole is the maximum circumference plus 3 mm.

[0023] In one embodiment, in step S10, the trailer hook is a rear trailer hook.

[0024] The technical solution of the present invention adopts different values ​​of X3, that is, different values ​​are taken for the length of the effective connection section of the trailer hook tube in the energy absorption box, and the traction performance analysis is performed on the trailer hook corresponding to each value to obtain the corresponding residual deformation and residual angle, and analyze whether the residual deformation and residual angle meet the design requirements. If they do, the X3 value meets the traction strength requirements, and multiple X3 values ​​that meet the traction strength are obtained in this way. Among the X3 values ​​that meet the traction strength, the smallest X3 value is selected as the final value, thereby determining the length of the effective connection section of the trailer hook tube in the energy absorption box, and the distance between the end of the trailer hook tube and the through hole is also determined. When the X3 value is small, the distance between the end of the trailer hook tube and the through hole is also small, so it is convenient for the user to screw the trailer hook into the trailer hook tube; when the fixed position of the trailer hook tube is determined, the aperture of the through hole is determined to better avoid interference or friction during use. Therefore, the design method of the trailer hook tube provided by the present invention is convenient for users to operate while ensuring that the trailer hook meets the traction strength. The trailer hook can be easily screwed into the trailer hook tube, and interference or friction can be better avoided during use. BRIEF DESCRIPTION OF THE DRAWINGS

[0025] In order to more clearly illustrate the embodiments of the present invention or the technical solutions in the prior art, the drawings required for use in the embodiments or the description of the prior art will be briefly introduced below. Obviously, the drawings described below are only some embodiments of the present invention. For ordinary technicians in this field, other drawings can be obtained based on the structures shown in these drawings without paying creative work.

[0026] Figure 1 A schematic diagram of the structure of the trailer hook and related parts provided by the present invention;

[0027] Figure 2 for Figure 1 Schematic diagram of the structure of the middle trailer hook;

[0028] Figure 3 A schematic diagram of a structure for applying loads to a trailer hook in directions one, two and three provided by the present invention;

[0029] Figure 4 A schematic diagram of the structure of applying loads to a trailer hook in directions four and five provided by the present invention;

[0030] Figure 5 A schematic structural diagram of a residual angle α formed by a trailer hook provided by the present invention when a load is applied;

[0031] Figure 6 A schematic structural diagram of an envelope formed by a trailer hook provided by the present invention when a load is applied.

[0032] Description of Figure Numbers:

[0033] 100. Trailer hook and related parts; 1. Energy absorption box; 2. Anti-collision beam; 3. Bumper skin; 31. Through hole; 4. Trailer hook tube; 41. Fixed structure; 5. Trailer hook.

[0034] The realization of the purpose, functional features and advantages of the present invention will be further explained in conjunction with embodiments and with reference to the accompanying drawings. DETAILED DESCRIPTION

[0035] The following will be combined with the drawings in the embodiments of the present invention to clearly and completely describe the technical solutions in the embodiments of the present invention. Obviously, the described embodiments are only part of the embodiments of the present invention, not all of the embodiments. Based on the embodiments of the present invention, all other embodiments obtained by ordinary technicians in this field without creative work are within the scope of protection of the present invention.

[0036] It should be noted that if the embodiments of the present invention involve directional indications (such as up, down, left, right, front, back, etc.), the directional indications are only used to explain the relative position relationship, movement status, etc. between the components in a certain specific posture. If the specific posture changes, the directional indication will also change accordingly.

[0037] In addition, if there are descriptions involving "first", "second", etc. in the embodiments of the present invention, the descriptions of "first", "second", etc. are only used for descriptive purposes and cannot be understood as indicating or implying their relative importance or implicitly indicating the number of technical features indicated. Therefore, the features limited to "first" and "second" may explicitly or implicitly include at least one of the features. In addition, if "and / or" or "and / or" appears in the full text, its meaning includes three parallel solutions. Taking "A and / or B" as an example, it includes solution A, solution B, or solutions that satisfy both A and B. In addition, the technical solutions between the various embodiments can be combined with each other, but it must be based on the ability of ordinary technicians in this field to implement. When the combination of technical solutions is contradictory or cannot be implemented, it should be deemed that such combination of technical solutions does not exist and is not within the scope of protection required by the present invention.

[0038] Usually when arranging a trailer hook, in order to ensure stability during towing, the trailer hook tube needs to be firmly connected to the vehicle body to ensure sufficient strength. The longer the X-direction length of the trailer hook tube connected to the vehicle body, the better the trailer hook can withstand the tensile pressure during towing. However, the longer the X-direction length of the trailer hook tube connected to the vehicle body means that the end of the trailer hook tube is farther away from the opening on the bumper skin, which makes it inconvenient for the user to screw the trailer hook into the trailer hook tube, causing inconvenience to the user's operation. Therefore, in order to ensure the towing strength of the trailer hook and the convenience of user operation, the X-direction dimensions of the main connecting components and gaps between the trailer hook and the bumper need to be reasonably designed.

[0039] In view of this, the present invention proposes a design method for a vehicle trailer hook, aiming to solve the technical problem of ensuring the traction strength of the trailer hook while facilitating user operation.

[0040] See also Figure 1 In one embodiment of the present invention, the design method of the automobile trailer hook comprises the following steps:

[0041] S10, constructing a simulated connection structure: the trailer hook tube 4 can be fixed in the energy absorption box 1 through the fixing structure 41, the bumper skin 3 is provided with a through hole 31, one end of the trailer hook 5 can extend into the trailer hook tube 4 through the through hole 31 and be threadedly connected to the trailer hook tube 4, wherein the energy absorption box 1 is fixed between the longitudinal beam and the anti-collision beam 2;

[0042] S20. In the X direction, the effective length of the energy absorption box is X1, the length of the fixed structure of the trailer hook tube is X2, the length of the effective connection section of the trailer hook tube in the energy absorption box is X3, and the length of the trailer hook tube is h; wherein, X2+X3<X1, and X3<h(1);

[0043] S30, on the basis of satisfying the relational expression (1) in step S20, X3 can take multiple values, each value corresponding to a connection state of the trailer hook tube in the energy absorption box, and the towing performance of the trailer hook in each connection state is analyzed to obtain the residual deformation Δd at the towing position of the trailer hook after the load is applied and unloaded A and the residual angle α, if Δd A ≤0.7mm, α≤1.5°, it means that the value of X3 can meet the demand of traction strength;

[0044] S40. Among the X3 values ​​that satisfy the traction strength, select the minimum value as the final value of X3 to determine the effective connection section of the trailer hook tube in the energy absorption box, and then determine the aperture of the through hole.

[0045] The technical solution of the present invention adopts different values ​​of X3, that is, different values ​​are taken for the length of the effective connection section of the trailer hook tube in the energy absorption box, and the traction performance analysis is performed on the trailer hook corresponding to each value to obtain the corresponding residual deformation and residual angle, and analyze whether the residual deformation and residual angle meet the design requirements. If they do, the X3 value meets the traction strength requirements, and multiple X3 values ​​that meet the traction strength are obtained in this way. Among the X3 values ​​that meet the traction strength, the smallest X3 value is selected as the final value, thereby determining the length of the effective connection section of the trailer hook tube in the energy absorption box, and the distance X4 between the end of the trailer hook tube and the through hole is also determined. When the X3 value is small, the distance between the end of the trailer hook tube and the through hole is also small, so it is convenient for the user to screw the trailer hook into the trailer hook tube; when the fixed position of the trailer hook tube is determined, the aperture of the through hole is determined to better avoid interference or friction during use. Therefore, the design method of the trailer hook tube provided by the present invention ensures that the trailer hook meets the traction strength and is convenient for users to operate, that is, the trailer hook can be easily screwed into the trailer hook tube, and interference or friction can be better avoided during use. Specifically, the trailer hook is a rear trailer hook.

[0046] In step S30, analyzing the traction performance of the trailer hook in each connection state includes the following steps:

[0047] S301. Mesh the trailer hook and related local components using finite element analysis software Hypermesh to establish a finite element model;

[0048] S302, applying a load to the towing position of the trailer hook;

[0049] S303. Use the Abaqus solver to calculate and analyze the residual deformation of the center point A of the traction part of the trailer hook and the residual deformation of the center point B of the end face of the connecting end of the trailer hook after the load is applied and unloaded. The residual displacement ΔdA at point A and the residual displacement ΔdB at point B are obtained from the post-processing software HyperView, and the residual angle α is obtained through ΔdA and ΔdB.

[0050] The technical solution of the present invention uses finite element analysis software to establish a finite element model of the trailer hook and related local components, and then applies a load to the traction part of the trailer hook to obtain the residual displacement ΔdA at point A and the residual displacement ΔdB at point B, thereby obtaining the residual angle α. Specifically, for point A and point B, the participants Figure 2 The center axis of the trailer hook is C1C2, the point where the center axis C1C2 intersects with the front end surface of the trailer hook is point B, and the point where the center axis C1C2 intersects with the traction part of the trailer hook is point A.

[0051] Specifically, in step S301, the local components related to the trailer hook include: an energy absorption box, a bumper skin, a trailer hook tube, and a fixing structure for fixing the trailer hook tube.

[0052] In order to better simulate the load that the trailer hook can bear under different working conditions, in step S302, the magnitude of the applied load F is: F = G M *g / 2, where G M It is the sum of the mass of the vehicle when it is unloaded and the maximum mass that the vehicle can load, and g is the acceleration due to gravity;

[0053] The directions of applied load F include: Direction 1, along the positive direction of the X-axis; Direction 2, in the XY plane, at an upward angle of 5° with the positive semi-axis of the X-axis; Direction 3, in the XY plane, at a downward angle of 5° with the positive semi-axis of the X-axis; Direction 4: in the XZ plane, at an angle of 25° to the left with the positive semi-axis of the X-axis; Direction 5, in the XZ plane, at an angle of 25° to the right with the positive semi-axis of the X-axis.

[0054] The technical solution of the present invention applies loads in multiple directions to the traction part of the trailer hook, that is, corresponding to multiple working conditions, so that the traction strength of the trailer hook can better meet different working conditions. Figure 3 , F1 corresponds to the application of load F along the positive direction of the X-axis, F2 corresponds to the application of load F at an upward angle of 5° with the positive semi-axis of X, and F3 corresponds to the application of load F at a downward angle of 5° with the positive semi-axis of X; refer to Direction 4 and Direction 5 Figure 4 , F4 corresponds to the application of load F at an angle of 25° to the left of the positive semi-axis of X, and F5 corresponds to the application of load F at an angle of 25° to the right of the positive semi-axis of X.

[0055] In order to ensure that the traction strength of the trailer hook can better meet the actual working conditions under the corresponding X3 value, in step S303, the calculation formula of the residual angle α is: α = arctan (Δd A -Δd B ) / D AB (2); where D AB is the distance between point A and point B.

[0056] In step S301, the steps of establishing a finite element model for the trailer hook and related local components are as follows: the trailer hook and the trailer hook tube are solid models, which are simulated using HEX8 hexahedral solid units; the sheet metal around the trailer hook is modeled using PSHELL units, and the grid size is 3mm×3mm; the threaded connection between the trailer hook and the trailer hook tube is modeled using *Tie contact, the weld between the trailer hook tube and the energy absorption box is simulated using rigid units, and the electric welding between local sheet metal parts is simulated using cweld units.

[0057] The technical solution of the present invention saves calculation costs while ensuring calculation requirements by establishing a finite element model for the trailer hook and related local components.

[0058] In step S30, when the applied load is along the positive direction of the X-axis, Δd A ≤0.7mm; when the direction of the applied load is in the XY plane, α≤1.5°; when the direction of the applied load is in the XZ plane, α≤0.2°.

[0059] The technical solution of the present invention can better ensure that the traction strength of the trailer hook meets the use requirements of various complex working conditions by limiting the residual displacement and residual angle generated by the loads under different working conditions.

[0060] In step S30, the value of X3 is determined in descending order.

[0061] The technical solution of the present invention selects the value of X3 in order from large to small, so as to obtain the minimum value of X3 that meets the requirements more quickly.

[0062] The smallest X3 value is selected as the final value, thereby determining the length of the effective connection section of the trailer hook tube in the energy absorption box, and the distance between the end of the trailer hook tube and the through hole is also determined. Then, the size of the through hole diameter needs to be determined to effectively avoid interference or friction during use. In step S40, the method for determining the through hole diameter is: after the X3 value is determined, CAE is used to superimpose the trailer hook position and state obtained under each load corresponding to the X3 value to form an envelope, and the maximum circumference of the envelope is obtained. The aperture of the through hole is the maximum circumference plus 3mm.

[0063] The technical solution of the present invention uses the envelope formed by the superposition of the positions and states generated under various working conditions as the basis for determining the aperture of the through hole, and the maximum circumference of the envelope plus 3mm is used as the aperture size. The aperture size determined in this way can effectively avoid interference or friction during use.

[0064] The above description is only an exemplary embodiment of the present invention, and does not limit the patent scope of the present invention. All equivalent structural changes made by using the contents of the present invention specification and drawings under the technical concept of the present invention, or directly / indirectly applied in other related technical fields are included in the patent protection scope of the present invention.

Claims

1. A method for designing a vehicle trailer hook, characterized in that: The steps include: S10, constructing a simulated connection structure: the trailer hook tube can be fixed in the energy absorption box by a fixing structure, a through hole is opened on the bumper skin, one end of the trailer hook can extend into the trailer hook tube through the through hole and be connected to the trailer hook tube thread; S20. In the X direction, the effective length of the energy absorption box is X1, the length of the fixed structure of the trailer hook tube is X2, the length of the effective connection section of the trailer hook tube in the energy absorption box is X3, and the length of the trailer hook tube is h; wherein, X2+X3<X1, and X3<h(1); S30, on the basis of satisfying the relational expression (1) in step S20, X3 can take multiple values, each value corresponding to a connection state of the trailer hook tube in the energy absorption box, and the towing performance of the trailer hook in each connection state is analyzed to obtain the residual deformation Δd at the towing position of the trailer hook after the load is applied and unloaded A and the residual angle α, if Δd A ≤0.7mm, α≤1.5°, it means that the value of X3 can meet the demand of traction strength; S40. Among the X3 values ​​that satisfy the traction strength, select the minimum value as the final value of X3 to determine the effective connection section of the trailer hook tube in the energy absorption box, and then determine the aperture of the through hole.

2. The design method of the automobile trailer hook according to claim 1, characterized in that: In step S30, analyzing the traction performance of the trailer hook in each connection state includes the following steps: S301. Mesh the trailer hook and related local components using finite element analysis software Hypermesh to establish a finite element model; S302, applying a load to the towing position of the trailer hook; S303, using the Abaqus solver to calculate and analyze the residual deformation of the center point A of the towing part of the towing hook and the residual deformation of the center point B of the end surface of the connecting end of the towing hook after the towing hook is loaded and unloaded, and the residual displacement Δd of point A is obtained from the post-processing software HyperView A and the residual displacement Δd at point B B , through Δd A and Δd B This results in a residual angle α.

3. The design method of the automobile trailer hook according to claim 2, characterized in that: In the step S301, the parts related to the trailer hook include: an energy absorption box, a bumper skin, a trailer hook tube, and a fixing structure for fixing the trailer hook tube.

4. The design method of a vehicle trailer hook as claimed in claim 2, characterized in that: In step S302, the magnitude of the applied load F is: F=G M *g / 2, where G M It is the sum of the mass of the vehicle when it is unloaded and the maximum mass that the vehicle can load, and g is the acceleration due to gravity; The directions of applied load F include: Direction 1, along the positive direction of the X-axis; Direction 2, in the XY plane, at an upward angle of 5° with the positive semi-axis of the X-axis; Direction 3, in the XY plane, at a downward angle of 5° with the positive semi-axis of the X-axis; Direction 4: in the XZ plane, at an angle of 25° to the left with the positive semi-axis of the X-axis; Direction 5, in the XZ plane, at an angle of 25° to the right with the positive semi-axis of the X-axis.

5. The method for designing a vehicle trailer hook according to claim 2, characterized in that: In step S303, the calculation formula of the residual angle α is: α=arctan(Δd A -Δd B ) / D AB (2); Among them, D AB is the distance between point A and point B.

6. The method for designing a vehicle trailer hook according to claim 2, characterized in that: In step S301, the steps of establishing a finite element model for the trailer hook and related local components are as follows: the trailer hook and the trailer hook tube are solid models, which are simulated using HEX8 hexahedral solid units; the sheet metal around the trailer hook is modeled using PSHELL units, and the grid size is 3mm×3mm; the threaded connection between the trailer hook and the trailer hook tube is modeled using *Tie contact, the weld between the trailer hook tube and the energy absorption box is simulated using rigid units, and the electric welding between local sheet metal parts is simulated using cweld units.

7. The method for designing a vehicle trailer hook according to claim 1, characterized in that: In step S30, when the applied load is along the positive direction of the X-axis, Δd A ≤0.7mm; when the direction of the applied load is in the XY plane, α≤1.5°; when the direction of the applied load is in the XZ plane, α≤0.2°.

8. The method for designing a vehicle trailer hook according to claim 1, characterized in that: In step S30, the value of X3 is determined in descending order.

9. The method for designing a vehicle trailer hook according to claim 1, characterized in that: In step S40, the method for determining the aperture of the through hole is: after the X3 value is determined, CAE is used to superimpose the trailer hook position and state obtained under each load corresponding to the X3 value to form an envelope, and the maximum circumference of the envelope is obtained. The aperture of the through hole is the maximum circumference plus 3mm.

10. The method for designing a vehicle trailer hook according to claim 1, characterized in that: In the step S10, the trailer hook is a rear trailer hook.

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