Simulated forklift gantry chain fracture safety verification method

Abstract

The invention relates to a safety verification method for simulating the breakage of a forklift gantry chain, and the method comprises the following steps: obtaining the cylinder bottom pressure of a gantry under different working conditions in a standard load state, and determining the impact load weight according to the cylinder bottom pressure under different working conditions; one chain of the portal frame is detached, the portal frame is lifted to the highest point, the impact load is connected with the portal frame through a rope, the impact load is lifted to the test height and then released, and the influence of breakage of the chains and installation parts of the chains on the safety of the whole vehicle is verified. By simulating actual working conditions on the whole forklift, the safety of the forklift caused by breakage or tearing of a gantry chain and mounting parts is verified, the safety of the forklift in the using process is improved, and serious safety accidents such as gantry collapse are avoided.

Description

Technical Field

[0001] The present invention relates to the technical field of forklifts, and in particular to a method for verifying the safety of simulating the breakage of the mast chain of a forklift. Background Art

[0002] As an important component of a forklift, the strength of the structural parts of the mast is related to the safety of forklift operation. The mast chain of a forklift is the core transmission component of the forklift's lifting system, and its function runs through key links such as the lifting of the fork, the stability of the goods, and the linkage of the mast structure.

[0003] Currently, there is no relevant verification method in the industry for the safety of the mast lifting chain and its installation components of a forklift after breakage or tearing on the whole forklift. There are only corresponding tests on individual components according to design requirements and standards, which can only meet the design performance requirements of individual components and are not tested under the actual working conditions of the whole vehicle. How to ensure that when the chain and its installation components break or tear due to improper use or other problems while ensuring the strength of the structural parts, the mast system of the forklift can still remain safe and not cause serious safety accidents such as mast collapse is a technical problem that needs to be solved urgently at present. Summary of the Invention

[0004] Based on this, the purpose of the present invention is to provide a method for verifying the safety of simulating the breakage of the mast chain of a forklift, which simulates the safety problems of the forklift caused by the breakage or tearing of the mast chain and its installation components under actual working conditions on the whole vehicle, and improves the safety of the forklift during use.

[0005] To achieve the above purpose, the present invention adopts the following technical solutions: The present invention provides a method for verifying the safety of simulating the breakage of the mast chain of a forklift, which includes the following steps: S1. Under the standard load state, obtain the cylinder bottom pressure of the mast under different working conditions, and determine the impact load weight according to the cylinder bottom pressure under different working conditions; S2. Remove one of the chains of the mast, raise the mast to the highest point, connect the impact load to the mast through a rope, lift the impact load to the test height and then release it to verify the impact of the breakage of the chain and its installation components on the safety of the whole vehicle.

[0006] As a further improvement of the above solution of the present invention, in step S1, the obtaining of the cylinder bottom pressure of the mast under different working conditions includes: S11. Raise the mast to a predetermined height at the maximum lifting speed and collect the cylinder bottom pressure in real time; S12. Raise the mast to the highest point at the maximum lifting speed and collect the cylinder bottom pressure in real time; S13. Lower the mast from the highest point to a predetermined height at the maximum lowering speed and collect the cylinder bottom pressure in real time.

[0007] As a further improvement of the above solution of the present invention, the predetermined height h = 1 / 2H , H is the maximum lifting height of the gantry.

[0008] As a further improvement of the above solution of the present invention, in step S1, the determining the impact load weight according to the cylinder bottom pressure under different working conditions includes: Comparing the collected cylinder bottom pressures to obtain the peak value of the cylinder bottom pressure P max , designing the weight of the impact load M 冲击 is:

[0009] Wherein, K is the static and dynamic load conversion coefficient, K = 0.8; M 门架 is the weight of the gantry, A is the cross-sectional area of the oil cylinder, g is the acceleration due to gravity.

[0010] As a further improvement of the above solution of the present invention, in step S1, it further includes the step of designing the static and dynamic load conversion coefficient: Determining the weight of the static load M 静载 : P max × A = M 1 × g = (M 门架 +M 静载 ）×g； The weight of the static load satisfies: placing the static load on the fork and keeping the gantry stationary, the currently collected cylinder bottom pressure P 当前 is the same as the peak value of the cylinder bottom pressure P max ; Then design the static and dynamic load conversion coefficient K as .

[0011] As a further improvement of the above solution of the present invention, in step S2, the end of the rope far from the impact load is fixed at the central position of the gantry fork.

[0012] As a further improvement of the above solution of the present invention, in step S2, the test height is 50 mm.

[0013] Compared with the prior art, the present invention has the following beneficial effects: The present invention verifies the safety of a forklift caused by the fracture or tearing of the mast chain and its mounting components by simulating the actual working conditions on the whole vehicle, improves the safety of the forklift during use, and avoids serious safety accidents such as the collapse of the mast. BRIEF DESCRIPTION OF THE DRAWINGS

[0014] Figure 1 FIG. is a flowchart of a method for verifying the safety of a simulated forklift mast chain fracture according to an embodiment of the present invention; Figure 2 FIG. is a schematic connection diagram of an impact load and a forklift in a method for verifying the safety of a simulated forklift mast chain fracture according to an embodiment of the present invention; Figure 3 FIG. is the cylinder bottom pressure change curve of a 1.6t forklift under different working conditions in an embodiment of the present invention; Figure 4 FIG. is the cylinder bottom pressure change curve of a 1.6t forklift under a 2.4t load impact in an embodiment of the present invention.

[0015] Reference numerals: 1, impact load; 2, rope; 3, mast; 4, forklift; 5, fork. DETAILED DESCRIPTION OF THE EMBODIMENTS

[0016] For ease of understanding of the present invention, the present invention will be described more comprehensively below in conjunction with specific embodiments. However, the present invention can be implemented in many different forms and is not limited to the embodiments described herein. On the contrary, these embodiments are provided so that the disclosure of the present invention will be more thorough and comprehensive.

[0017] Unless otherwise defined, all technical and scientific terms used herein have the same meaning as commonly understood by those skilled in the technical field to which the present invention belongs. The terms used in the description of the present invention herein are only for the purpose of describing specific embodiments and are not intended to limit the present invention.

[0018] Refer to Figure 1 , an embodiment of the present invention proposes a method for verifying the safety of a simulated forklift mast chain fracture, which includes the following steps: S1. Under the standard load state, obtain the cylinder bottom pressure of the mast under different working conditions, and determine the impact load weight according to the cylinder bottom pressure under different working conditions.

[0019] In this embodiment, obtaining the cylinder bottom pressure of the mast under different working conditions includes: S11. Lift the mast to a predetermined height at the maximum lifting speed and collect the cylinder bottom pressure in real time; S12. Lift the mast to the highest point at the maximum lifting speed and collect the cylinder bottom pressure in real time; S13. Lower the mast from the highest point to the predetermined height at the maximum descent speed and collect the bottom pressure of the cylinder in real time.

[0020] It should be noted that different forklifts have different maximum lifting speeds and maximum descent speeds, and the maximum lifting speeds and maximum descent speeds of each type of forklift mast are known. To ensure data stability, steps S11, S12, and S13 of this embodiment can be repeated several times to stack multiple sets of data and verify repeatability.

[0021] In step S11, the predetermined height h = 1 / 2H , H is the maximum lifting height of the mast. Similarly, the maximum lifting heights of the masts of different forklifts are also different. In this embodiment, a pressure recorder can be used to collect the bottom pressure of the cylinder.

[0022] In this embodiment, determining the impact load weight according to the bottom pressure of the cylinder under different working conditions includes the following steps: Compare the collected bottom pressure of the cylinder, draw a pressure change curve, and obtain the peak bottom pressure P max , design the weight of the impact load M 冲击 as:

[0023] Among them, K is the static and dynamic load conversion coefficient, K = 0.8; M 门架 is the weight of the mast, A is the cross-sectional area of the oil cylinder, g is the acceleration due to gravity.

[0024] Among them, the static and dynamic load conversion coefficient K is designed by the following method: Determine the weight of the static load M 静载 : P max × A = M 1 × g = (M 门架 +M 静载 ）×g； The weight of the static load satisfies: Place the static load on the fork and keep the mast stationary, and the currently collected bottom pressure of the cylinder P 当前 is equal to the peak bottom pressure P max ; Then design the static and dynamic load conversion coefficient K as 。

[0025] S2. Remove one of the chains of the forklift mast, and the remaining chain is used as the verification chain; in combination with Figure 2 , raise the mast 3 to the highest point, connect the impact load 1 to the forklift mast fork 5 through the rope 2, lift the impact load 1 to the test height and then release it, and verify the impact on the vehicle safety caused by the fracture of the verification chain and its installation components.

[0026] In this embodiment, to ensure the accuracy of the test, the end of the rope far from the impact load 1 is fixed at the central position of the forklift mast fork 5.

[0027] In this embodiment, other equipment (such as another forklift) can be used to lift the impact load to the test height, and the test height is preferably 50 mm here.

[0028] Next, a forklift with a standard load of 1.6 t, a three-stage full-free mast, and a maximum mast lifting height of 4.7 meters is used to verify the feasibility of the method of this embodiment, and the cylinder bottom pressure change curve as shown in Figure 3 is obtained. By analysis, the peak value of the cylinder bottom pressure P max = 21.5 MPa, and the weight of the impact load is obtained as 2.4 t; the 2.4 impact load is lifted by 50 mm and released, and the cylinder bottom pressure change curve as shown in Figure 4 is obtained. It can be regarded that the released impact pressure is 21.97 MPa, which is the same as the peak pressure in the actual working condition, verifying the feasibility of the method of this embodiment.

[0029] The technical features of the above-described embodiments can be combined arbitrarily. For the sake of brevity of description, not all possible combinations of the technical features in the above-described embodiments are described. However, as long as there is no contradiction in the combination of these technical features, it should be considered as the scope recorded in this specification.

[0030] The above-described embodiments only represent several implementation manners of the present invention. The description is relatively specific and detailed, but it should not be construed as a limitation on the scope of the invention patent. It should be noted that for those of ordinary skill in the art, without departing from the concept of the present invention, several deformations and improvements can still be made, and these all belong to the protection scope of the present invention. Therefore, the protection scope of the present invention patent shall be subject to the appended claims.

Claims

1. A method for verifying the safety of a forklift mast chain breakage simulation, characterized in that, It includes the following steps: S1. Under the standard load condition, obtain the cylinder bottom pressure of the mast under different working conditions, and determine the impact load weight according to the cylinder bottom pressure under different working conditions; S2. Remove one of the chains of the mast, lift the mast to the highest point, connect the impact load to the mast through a rope, lift the impact load to the test height and then release it to verify the impact on the vehicle safety caused by the fracture of the chain and its installation components.

2. The method for verifying the safety of the simulated forklift mast chain breakage according to claim 1, wherein, In step S1, the obtaining of the cylinder bottom pressure of the mast under different working conditions includes: S11. Lift the mast to a predetermined height at the maximum lifting speed and collect the cylinder bottom pressure in real time; S12. Lift the mast to the highest point at the maximum lifting speed and collect the cylinder bottom pressure in real time; S13. Lower the mast from the highest point to a predetermined height at the maximum lowering speed and collect the cylinder bottom pressure in real time.

3. The method for verifying the safety of the simulated forklift mast chain breakage according to claim 2, wherein, The predetermined height h = 1 / 2H , H is the maximum lifting height of the gantry.

4. The method for verifying the safety of the simulation forklift mast chain breakage according to claim 1, characterized in that, In step S1, the determining of the impact load weight according to the cylinder bottom pressure under different working conditions includes: Compare the collected bottom pressure of the cylinder to obtain the peak bottom pressure of the cylinder P max , design the weight of the impact load M 冲击 It is: Among them, K is the dynamic-static load conversion coefficient, K = 0.8; M 门架 is the weight of the gantry, A is the cross-sectional area of the oil cylinder, g is the acceleration due to gravity.

5. The method for verifying the safety of the simulated forklift mast chain breakage according to claim 4, wherein In step S1, it also includes the step of designing the dynamic and static load conversion coefficient: Determine the weight of the static load M 静载 : P max ×A = M 1 ×g = (M 门架 +M 静载 ）×g； The weight of the static load satisfies that when the static load is placed on the forks and the mast is kept stationary, the currently collected bottom pressure of the cylinder P 当前 is the same as the peak bottom pressure of the cylinder P max ; Then design the dynamic and static load conversion coefficient K is .

6. The method for verifying the safety of the simulated forklift mast chain breakage according to claim 1, characterized in that In step S2, the end of the rope far from the impact load is fixed at the center position of the mast fork.

7. The method for verifying the safety of the simulated forklift mast chain breakage according to claim 1, wherein In step S2, the test height is 50 mm.

Images