A turnover mechanism of a telescopic arm forklift

Abstract

The utility model provides a kind of turnover mechanism of telescopic arm fork truck, including the arm support and pallet fork frame of rotation connection, the elbow of the arm support is rotatably installed, and the end of the elbow is rotatably connected with the pallet fork frame by connecting rod;Turnover cylinder is installed on the arm support, and the piston rod of the turnover cylinder is rotatably connected with the elbow.The utility model's turnover mechanism reduces the oil pressure of turnover cylinder, so that the pallet fork can be flexibly turned up, and the high-pressure impact force on the arm support and elbow is also reduced;And through the structure of the elbow, the strength and service life of the elbow structure are further increased.

Description

Technical Field

[0001] This utility model relates to the field of telescopic boom forklift technology, specifically to a tipping mechanism for a telescopic boom forklift. Background Technology

[0002] A telescopic boom forklift is a multi-purpose engineering machine that integrates the functions of a forklift and a crane. It generally has a telescopic boom that is connected to a fork carriage with forks installed through the boom, so that the length of the telescopic boom can be flexibly adjusted to adapt to different operating needs. It is often used in warehouses, production lines and outdoor sites to efficiently handle long and narrow goods or hard-to-reach materials.

[0003] To prevent cargo from falling during the boom's ascent and descent, the forks must remain horizontal at all times. Therefore, the fork carriage must be able to tilt up and down relative to the boom. A tilting cylinder is typically used to connect the boom and fork carriage, driving the fork carriage to tilt up and down. When the forks are loaded and tilting upwards, the thrust of the tilting cylinder must overcome the significant resistance created by the weight of the cargo, causing a sharp increase in hydraulic pressure. If the hydraulic pressure in the tilting cylinder exceeds the set value of the hydraulic system's relief valve (e.g., 28 MPa, the hydraulic pressure in the tilting cylinder can momentarily overpressure to 35 MPa), the forks will be unable to tilt upwards. Simultaneously, the high-pressure impact can cause stress concentration in the boom, affecting its strength and potentially reducing its service life. Utility Model Content

[0004] In view of this, the present invention aims to provide a tipping mechanism for a telescopic boom forklift to overcome the shortcomings of the prior art, thereby reducing the pressure of the tipping cylinder during tipping operations, while increasing the strength and service life of the boom.

[0005] The specific technical solution is as follows:

[0006] A tipping mechanism for a telescopic forklift includes a boom and a fork carriage rotatably connected together. A curved arm is rotatably mounted on the boom, and the end of the curved arm is rotatably connected to the fork carriage via a connecting rod. A tipping cylinder is mounted on the boom, and the piston rod of the tipping cylinder is rotatably connected to the curved arm.

[0007] In a further embodiment, the curved arm has an arc-shaped structure. One end of the curved arm is rotatably connected to the boom via a first pin, and the other end is rotatably connected to one end of a connecting rod via a third pin. The other end of the connecting rod is rotatably connected to the fork carriage via a fourth pin. The middle part of the curved arm is rotatably connected to the piston end of the tilting cylinder via a second pin.

[0008] In a further embodiment, the boom includes two symmetrically arranged side plates connected by a web plate; a boom mounting seat is installed at one end of the boom and a connecting rod mounting seat is installed at the other end; cylinder mounting holes are symmetrically opened on the two side plates located in the middle of the boom.

[0009] Preferably, the boom mounting base and the connecting rod mounting base are both cylindrical structures, which pass through the two side uprights respectively.

[0010] In a further embodiment, a reinforcing plate is fixed to the outer side wall of the side plate, the thickness of the side plate and the reinforcing plate is not less than 30 mm, and the thickness of the web plate is not less than 15 mm.

[0011] In a further embodiment, forks are installed on the fork carriage. When the forks are loaded with goods and are flipped during the lifting process, with the hinge point between the bent arm and the boom as the fulcrum P, the ratio of the lever arm L1 of the force exerted by the flipping cylinder on the bent arm and the lever arm L2 of the force exerted by the connecting rod on the bent arm is not less than 0.5, and the ratio of the pushing and pulling force F of the flipping cylinder to the weight G of the goods is not greater than 10.

[0012] This application rotatably connects the boom, tilting cylinder, boom arm, connecting rod, and fork carriage, forming a six-bar linkage. The extension and retraction of the piston rod of the tilting cylinder drives the boom arm to move the connecting rod, which in turn drives the fork carriage and forks to tilt together.

[0013] This application limits the ratio of the lever arm L1 of the tilting cylinder to the lever arm L2 of the connecting rod when the forklift is tilting during lifting and lowering, ensuring it is not less than 0.5. It also limits the ratio of the pushing / pulling force F of the tilting cylinder to the weight G of the cargo to not more than 10. This reduces the hydraulic pressure in the tilting cylinder, allowing the forks to tilt more flexibly. It also reduces the high-pressure impact force on the boom and the forklift.

[0014] This application designs the boom as an arc-shaped structure and adds a web and reinforcing plates to improve the overall structural strength of the boom. Furthermore, the reinforcing plates are connected to the boom frame, reducing wear on the side uprights of the boom body. In addition, this application limits the minimum thickness of the web, side uprights, and reinforcing plates, further increasing the strength and service life of the boom structure. Attached Figure Description

[0015] Figure 1 This is a schematic diagram of the structure of this utility model;

[0016] Figure 2 This is a schematic diagram of the curved arm structure in this utility model;

[0017] Figure 3 This is a force diagram of the flipping mechanism of this utility model.

[0018] In the diagram: 1-Boom, 2-Tilting cylinder, 3-Arching boom, 4-Linkage, 5-Fork carriage, 6-Forks, 8-Telescopic boom; 31-Side upright, 32-Body plate, 33-Reinforcing plate, Boom mounting base 311, Cylinder mounting hole 312, Linkage mounting base 313.

[0019] L1 - the lever arm of the tilting cylinder on the bent arm, L2 - the lever arm of the connecting rod on the bent arm, F is the pushing and pulling force of the tilting cylinder, G is the weight of the cargo, and P is the fulcrum. Detailed Implementation

[0020] To make the objectives, technical solutions, and advantages of this utility model clearer, the present utility model 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 of the present utility model and are not intended to limit the present utility model.

[0021] Example 1:

[0022] like Figure 1-2 As shown, a tipping mechanism for a telescopic forklift includes a boom 1 and a fork carriage 5 that are rotatably connected. Specifically, they can be connected by a connecting shaft 7, allowing the fork carriage 5 to rotate around the connecting shaft 7. A telescopic boom 8 is mounted on the boom 1, and forks 6 are mounted on the fork carriage 5. The length of the telescopic boom 8 can be flexibly adjusted so that the forks 6 can adapt to the loading needs of goods at different distances.

[0023] A curved arm 3 is rotatably mounted on the boom 1, and the end of the curved arm 3 is rotatably connected to the fork carriage 5 via a connecting rod 4. A tilting cylinder 2 is mounted on the boom 1, and the piston rod of the tilting cylinder 2 is rotatably connected to the curved arm 3. That is, the cylinder of the tilting cylinder 2 is rotatably mounted on the boom 1 via a pin 5, and the piston rod of the tilting cylinder 2 is rotatably connected to the curved arm 3. The extension and retraction of the piston rod of the tilting cylinder 2 drives the curved arm 3 to move the connecting rod 4, which in turn drives the fork carriage 5 and the forks 6 to tilt together. Thus, the boom 1, the tilting cylinder 2, the curved arm 3, the connecting rod 4, and the fork carriage 5 form a six-bar linkage mechanism.

[0024] Specifically, the connection method is that the curved arm 3 has an arc-shaped structure (e.g., Figure 2 As shown, one end of the curved boom 3 is rotatably connected to the boom 1 via pin 1, and the other end is rotatably connected to one end of the connecting rod 4 via pin 3. The other end of the connecting rod is rotatably connected to the fork carriage 5 via pin 4. The middle part of the curved boom is rotatably connected to the piston end of the tilting cylinder 2 via pin 2.

[0025] like Figure 2As shown, the boom 3 includes two symmetrically arranged side plates 31, which are connected by a web plate 32; a boom mounting seat 311 is installed at one end of the boom 3 and a connecting rod mounting seat 313 is installed at the other end; cylinder mounting holes 312 are symmetrically opened on the two side plates 31 located in the middle of the boom 3.

[0026] Among them, the boom mounting base 311 and the connecting rod mounting base 313 are both cylindrical structures, which pass through the two side upright plates 31 respectively, and are used to connect the boom and connecting rod after the pin is inserted.

[0027] To enhance the structural strength of the curved arm 3, a reinforcing plate 33 is fixed to the outer wall of the side upright plate 31. The thickness of the side upright plate 31 and the reinforcing plate 33 is not less than 30 mm, and the thickness of the web plate 32 is not less than 15 mm.

[0028] When the forks 6 are loaded with goods and are tilted during the lifting process, the hinge point between the curved arm 3 and the boom 1 is used as the fulcrum P, such as... Figure 3 As shown, the ratio of the lever arm L1 of the tilting cylinder 2 to the lever arm L2 of the connecting rod to the bending arm is not less than 0.5, and the ratio of the pushing and pulling force F of the tilting cylinder 2 to the weight G of the cargo is not greater than 10.

[0029] Example 2:

[0030] This embodiment specifically describes the tipping mechanism of a 4-ton telescopic forklift, which includes a boom, a tipping cylinder, a curved arm, a connecting rod, and a fork carriage. The boom 1 and the fork carriage 5 are connected by a connecting shaft 7. One end of the curved arm 3 is rotatably connected to the boom 1, and the other end is rotatably connected to the fork carriage 5 through a connecting rod 4. The cylinder of the tipping cylinder 2 is rotatably mounted on the boom 1, and the piston rod of the tipping cylinder 2 is rotatably connected to the curved arm 3. The extension and retraction movement of the piston rod of the tipping cylinder 2 drives the curved arm 3 to move the connecting rod 4, thereby causing the fork carriage 5 and the forks 6 to perform a tipping movement together.

[0031] The maximum upward tilt angle of the fork carriage is approximately 15°, and the maximum downward tilt angle is approximately 125°. When the fork carriage is in its maximum upward tilt state, the pushing and pulling force F of the tilting cylinder is at its maximum. Taking the hinge point P between the fork arm and the boom as the fulcrum, the ratio of the lever arm L1 of the tilting cylinder force to the lever arm L2 of the connecting rod force is approximately 0.6, while the ratio of the tilting cylinder pushing and pulling force F to the weight G of the cargo is approximately 9.5. The fork arm is a welded component consisting of side uprights, a web, and reinforcing plates. The web thickness is 20mm, the side upright thickness is 35mm, and the reinforcing plate thickness is 45mm.

[0032] Through multibody dynamics simulation analysis and structural finite element analysis, the maximum pressure of the tilting cylinder in this embodiment is no greater than 25MPa in all operating scenarios, which is less than the overflow pressure of 28MPa set by the hydraulic system; thus improving the flexibility of the fork tilting operation. Furthermore, the stress on the boom is less than its set bearing capacity, meeting its fatigue life design requirements. Therefore, the tilting mechanism of this invention overcomes the shortcomings of the prior art, achieving the goal of reducing the hydraulic pressure of the tilting cylinder during tilting operations, while also increasing the strength and service life of the boom.

[0033] Those skilled in the art will readily understand that the above description is merely a preferred embodiment of the present utility model and is not intended to limit the present utility model. Any modifications, equivalent substitutions, and improvements made within the spirit and principles of the present utility model should be included within the protection scope of the present utility model.

Claims

1. A tilting mechanism for a telescopic arm fork lift truck comprising a pivotally connected arm frame (1) and a fork frame (5), characterised in that, A curved arm (3) is rotatably mounted on the boom (1), and the end of the curved arm (3) is rotatably connected to the fork carriage (5) via a connecting rod (4); a tilting cylinder (2) is mounted on the boom (1), and the piston rod of the tilting cylinder (2) is rotatably connected to the curved arm (3).

2. The roll-over mechanism of a telehandler according to claim 1, characterized in that, The curved arm (3) has an arc-shaped structure. One end of the curved arm (3) is rotatably connected to the boom (1) through a pin one, and the other end is rotatably connected to one end of the connecting rod (4) through a pin three. The other end of the connecting rod is rotatably connected to the fork carriage (5) through a pin four. The middle part of the curved arm is rotatably connected to the piston end of the tilting cylinder (2) through a pin two.

3. The roll over mechanism for a telehandler as claimed in claim 2 wherein, The boom (3) includes two symmetrically arranged side plates (31), which are connected by a web plate (32); a boom mounting seat (311) is installed at one end of the boom (3), and a connecting rod mounting seat (313) is installed at the other end; cylinder mounting holes (312) are symmetrically opened on the two side plates (31) located in the middle of the boom (3).

4. The roll-over mechanism of a telehandler according to claim 3, characterized in that, The boom mounting base (311) and the connecting rod mounting base (313) are both cylindrical structures, which pass through the two side uprights (31) respectively.

5. The roll-over mechanism of a reach truck as claimed in claim 3, wherein, A reinforcing plate (33) is fixedly provided on the outer side wall of the side plate (31), the thickness of the side plate (31) and the reinforcing plate (33) is not less than 30 mm, and the thickness of the web plate (32) is not less than 15 mm.

6. The roll over mechanism for a telehandler as set forth in claim 1, wherein, The fork carriage (5) is equipped with forks (6). When the forks (6) are loaded with goods and are flipped during the lifting process, with the hinge point between the bent arm (3) and the boom (1) as the fulcrum P, the ratio of the force arm L1 of the flipping cylinder (2) on the bent arm and the force arm L2 of the connecting rod on the bent arm is not less than 0.5, and the ratio of the pushing and pulling force F of the flipping cylinder (2) to the weight G of the goods is not greater than 10.

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