Anti-falling safety protection device for hydraulic lift truck

Abstract

An anti-falling safety protection device for a hydraulic lift truck is characterized in that a telescopic arm of the hydraulic lift truck is provided with a movable hinge shaft on a truck body, and the anti-falling safety protection device is mounted on the truck body of the hydraulic lift truck and comprises a connecting bracket, a long rack, a short rack, a guide sleeve, a telescopic electric cylinder and a button box; the button box controls the telescopic electric cylinder to downwards push the short rack to be meshed with the long rack, so that the position of the long rack is fixed, the movable hinge shaft is locked to prevent the telescopic arm from moving up and down, and the working platform gravity borne by the telescopic arm is transmitted to the connecting support fixed to the vehicle body through the long rack and the short rack. And the working platform is stably stopped at the original position, so that the occurrence of falling is prevented. The hydraulic lift truck has mechanical and hydraulic double supports, the effect of effectively eliminating the potential safety hazard of accidental falling of the working platform caused by hydraulic faults is achieved, and the hydraulic lift truck has the advantages of being simple in structure, convenient to operate, low in manufacturing cost, safe and reliable.

Description

Technical Field

[0001] The present invention relates to the safe use of elevated equipment, and particularly to an anti-falling safety protection device for a hydraulic lift truck, belonging to the technical field of elevated equipment safety. Background Art

[0002] The hydraulic lift truck is one of the frequently used equipment for working at heights. Please refer to Figure 2 , the hydraulic lift truck includes a vehicle body 01, a working platform 02, a telescopic arm 03, a hydraulic station, a hydraulic cylinder and other parts. Among them, the hydraulic station is composed of components such as an oil tank, an oil pump, a relief valve, and high-pressure oil pipes. When the hydraulic station is powered on and the oil pump works, high-pressure oil is delivered into the hydraulic cylinder, and the telescopic arm 03 is lifted by the hydraulic cylinder, driving the working platform 02 to rise to the required working height. The upper part of the telescopic arm 03 supports the working platform 02, and the lower part is fixed on the chassis of the vehicle body 01. The telescopic arm 03 is a component articulated by a plurality of parallelogram link mechanisms. The two articulated shafts at its lower part are connected to the chassis of the vehicle body 01 and are at the same horizontal level. One of the articulated shafts is fixed on the chassis, and the other movable articulated pin shaft 031 can move horizontally along the chassis. When the movable articulated pin shaft 031 moves horizontally inward, the telescopic arm 03 extends upward through the action of the parallelogram link mechanism, thereby lifting the working platform 02 to reach the working height. During the operation, the hydraulic lift truck only relies on the hydraulic pressure provided by the hydraulic station and the hydraulic cylinder to support, so as to keep the position of the working platform 02 unchanged. When the operation is completed, the hydraulic station retracts the telescopic arm 03 by means of pressure relief and oil return, thereby lowering the working platform 02.

[0003] With the increase in the service life of the hydraulic lift truck and the complexity of various on-site working conditions, there are potential hazards of oil leakage, rupture or even explosion in the high-pressure oil pipes and hydraulic cylinders. If the working platform 02 only relies on the hydraulic pressure of the hydraulic station and the hydraulic cylinder for support alone, once the oil cylinder or oil pipe ruptures, it will cause the working platform 02 of the lift truck to fall due to weightlessness, and serious personal injury accidents may occur. Therefore, adding an anti-falling safety protection device to the hydraulic lift truck can effectively avoid the potential safety hazards to personnel caused by hydraulic failures. Summary of the Invention

[0004] The technical problem to be solved by the present invention is to make up for the safety defect that the working platform will fall when the hydraulic support system of the existing hydraulic lift truck fails, and provide an anti-falling safety protection device for the hydraulic lift truck, which is independent of the hydraulic system of the hydraulic lift truck and provides another mechanical support for the working platform, forming a second layer of safety protection for the hydraulic lift truck, so as to effectively eliminate the potential safety hazard of the working platform falling caused by hydraulic failures.

[0005] To achieve the above object, the technical solution of the present invention is as follows:

[0006] An anti-falling safety protection device for a hydraulic lift truck. The hydraulic lift includes a vehicle body, a telescopic arm, and a working platform connected in sequence from bottom to top. A movable hinge pin shaft is provided at the bottom of the telescopic arm, and this movable hinge pin shaft can move horizontally along the vehicle body to lift the working platform by the telescopic arm. It is characterized in that: The anti-falling safety protection device is installed on the vehicle body and includes a bracket, a long rack, a short rack, a guide sleeve, a telescopic electric cylinder, and a button box;

[0007] The connecting bracket is fixed on the vehicle body. The long rack is horizontally arranged on the vehicle body, and its upper surface is provided with engaging teeth. One end of the long rack is fixedly connected to the movable hinge pin shaft and can move horizontally with this movable hinge pin shaft. The short rack is arranged parallel to the long rack above it, and its lower surface is provided with engaging teeth that can mesh with the engaging teeth of the long rack. The guide sleeve is connected between the connecting bracket and the short rack to restrict and guide the vertical movement of the short rack. The guide sleeve includes a guide shaft and a guide sleeve that are slidably engaged with each other. The guide shaft is fixed to the short rack and can slide up and down within the guide sleeve. The guide sleeve is vertically fixed on the connecting bracket. The upper end of the telescopic electric cylinder is fixedly connected to the connecting bracket, and the lower end is fixedly connected to the short rack and drives the short rack to move up and down. The button box is arranged on the working platform, is electrically connected to the telescopic electric cylinder, and controls the retraction and extension movement of the telescopic electric cylinder;

[0008] The button box controls the telescopic electric cylinder to extend and push the short rack downward, so that the engaging teeth of the short rack and the long rack mesh with each other, thereby restricting the horizontal movement of the long rack, and further locking the movable hinge shaft and the telescopic arm. The gravity of the working platform acting on the telescopic arm is transmitted to the connecting bracket fixed on the vehicle body through the long rack and the short rack, so that the working platform stops stably at its original position in the air to prevent the fall of the working platform caused by a hydraulic system failure.

[0009] Further, the engaging teeth of the short rack and the long rack are trapezoidal straight teeth.

[0010] Further, a limit switch is provided on the connecting bracket to limit the stroke of the telescopic electric cylinder and the short rack.

[0011] Further, the rated voltage of the telescopic electric cylinder is DCV, the maximum speed is 10mm / S, and the maximum stroke is 30mm.

[0012] Further, the button box includes an up button, a down button, and an indicator light. When the indicator light is on, it indicates that the anti-falling safety protection device is not in effect.

[0013] Furthermore, the number of the anti-falling safety protection devices is two sets, which are respectively installed on the front and rear sides of the body of the hydraulic lift truck.

[0014] Compared with the prior art, the present invention can support and lock the working platform in the case of the failure of the hydraulic system of the lift truck, prevent the accidental fall of the working platform, ensure the safety of the operators and equipment, and has the following advantages:

[0015] A. The anti-falling safety protection device has a simple structure and low manufacturing cost, and at the same time, it is convenient to batch-transform the existing lift trucks without this function.

[0016] B. The present invention is simple to use and convenient to operate, has low skill requirements for operators, and does not require special training for personnel.

[0017] C. The present invention is small in size and strong in load-bearing capacity, and can effectively support the working platform from falling in the case of the failure of the hydraulic system of the lift truck.

[0018] D. The present invention has an open structure, which is convenient for daily inspection and maintenance, and the wire-controlled button box is convenient for operators to control the anti-falling safety protection device at different positions.

[0019] In summary, the present invention achieves the effect of having double anti-falling safety protection of machinery and hydraulics during the high-altitude operation of the hydraulic lift truck, and has the advantages of simple structure, convenient operation, low cost and safety and reliability. BRIEF DESCRIPTION OF THE DRAWINGS

[0020] Figure 1 is a schematic structural diagram of the present invention.

[0021] Figure 2 is a schematic diagram of the installation position of the present invention on the hydraulic lift truck.

[0022] Figure 3 is Figure 2 a side view of

[0023] In the figure, 01 - body, 02 - working platform, 03 - telescopic arm, 031 - movable hinge pin shaft, 04 - anti-falling safety protection device, 1 - connecting bracket, 2 - long rack, 3 - short rack, 4 - guide sleeve, 5 - telescopic electric cylinder, 6 - button box. DETAILED DESCRIPTION OF THE EMBODIMENTS

[0024] The following further describes in detail the anti-falling safety protection device for the hydraulic lift truck according to the present invention with reference to the drawings and specific embodiments.

[0025] The present invention is used for preventing the fall of the working platform of a hydraulic lift truck, and realizes a second mechanical support for the telescopic arm of the hydraulic lift truck to prevent the accidental fall of the working platform when a hydraulic system failure occurs. Please refer to Figure 1 and Figure 2 , the hydraulic lift truck includes a vehicle body 01, a working platform 02 and a telescopic arm 03; the working platform 02 is arranged on the upper part of the telescopic arm 03, the lower part of the telescopic arm 03 is fixed on the chassis of the vehicle body 01, and the telescopic arm 03 is composed of a plurality of parallelogram link mechanisms hinged together, and the two hinge shafts at the lowermost part are connected to the chassis of the vehicle body 01, and the movable hinge shaft 031 thereof can move horizontally along the chassis of the vehicle body 01.

[0026] Embodiment

[0027] Please refer to Figure 1 , the anti-fall safety protection device 04 is installed on the vehicle body 01 and includes a connecting bracket 1, a long rack 2, a short rack 3, a guide sleeve 4, a telescopic electric cylinder 5 and a button box 6.

[0028] The connecting bracket 1 is welded to the body 01 of the hydraulic lift truck. The long rack 2 is horizontally arranged on the chassis of the body 01, with a length of 0.5 * body length + 170 mm. The upper surface is provided with trapezoidal teeth. One end of the long rack 2 is fixedly connected to the movable hinge pin 031 at the bottom of the telescopic arm 03 through a steel sleeve, and can move horizontally along with the movable hinge pin 031 when the telescopic arm 03 is lifted and telescoped. The other end is a free end. The guide sleeve 4 is connected between the connecting bracket 1 and the short rack 3. The guide sleeve 4 includes a guide shaft and a guide sleeve that are slidably engaged with each other. The guide shaft is fixed to the short rack 3 and can slide up and down in the guide sleeve. The guide sleeve is vertically and fixedly connected to the connecting bracket 1, which is used to restrict the lateral movement of the short rack 3 and bear the lateral force, and at the same time provides a stable guide for the longitudinal movement of the short rack 3. The short rack 3 is arranged parallel to the long rack 2, and the lower surface is provided with trapezoidal teeth that mesh with the trapezoidal teeth of the long rack 2. The length of the short rack 3 is 170 mm. The telescopic electric cylinder 5 is a hydraulically driven cylinder powered by electricity. The upper end is fixedly connected to the connecting bracket 1, and the lower end is fixedly connected to the short rack 3. The telescopic electric cylinder 5 is of model STA02, with a voltage grade of DC24V, a speed of 10 mm / S, and a stroke of 30 mm. A limit switch is provided on the connecting bracket 1 to limit the stroke of the telescopic electric cylinder 5 and the short rack 3, and model TZ-8108 is selected. The button box 6 is arranged on the working platform 02 of the hydraulic lift truck and is electrically connected to the telescopic electric cylinder 5. The button box 6 is suspended on the railing of the working platform 02 through a metal box, which is convenient for the operator to operate. The button box 6 includes an up button, a down button, an indicator light, etc., and can control the telescopic electric cylinder 5 to drive the short rack 3 to move up and down. The indicator light is red. When the indicator light is lit, it means that the anti-falling safety protection device is not in effect, and the hydraulic lift truck is in an unsafe state.

[0029] The button box 6 controls the telescopic electric cylinder 5 to extend downward, pushing the short rack 3 to mesh with the trapezoidal teeth of the long rack 2, thereby fixing the movement of the long rack 2, locking the position of the long rack 2, and then locking the movable hinge shaft 031 to prevent the up and down movement of the telescopic arm 03. At this time, the force received by the telescopic arm 03 will be transmitted to the connecting bracket 1 fixed on the body 01 through the long rack 2 and the short rack 3, so that the working platform 02 stops stably at the original position in the air, achieving the purpose of preventing the working platform from falling due to hydraulic system failure. When the button box 6 controls the telescopic electric cylinder 5 to lift upward, pulling the short rack 3 to disengage from the long rack 2, thereby unlocking the telescopic arm 03, and then the working platform 02 can move up and down under the drive of the hydraulic system again.

[0030] For safety and reliability, a fall prevention safety protection device 04 can be installed on each of the front and rear sides of the body 01 of the hydraulic lift truck, as shown in Figure 3 .

[0031] The working principle of the present invention is as follows:

[0032] Please refer to Figure 2 and Figure 3 . At the working site of the hydraulic lift truck, when the working platform 02 of the hydraulic lift truck is raised to the working height, the operator presses and holds the "ON" button of the control box 6 for a long time. The telescopic electric cylinder 5 will push the short rack 3 downward to engage it with the long rack 2. At the same time as the racks are engaged, the limit switch is pressed down, and the red indicator light on the control box 6 goes out, and the fall prevention safety protection device 04 comes into effect. The gravity of the working platform 02 will be transmitted to the long rack 2 through the telescopic arm 03, then through the short rack 3 and the guide sleeve 4 to the connecting bracket 1, and finally transmitted to the body 01 of the hydraulic lift truck, so as to support and lock the position of the working platform 02 to prevent falling. After the operator finishes the high-altitude operation, press and hold the "OFF" button, the telescopic electric cylinder will drive the short rack 3 upward to separate it from the long rack 2, and at the same time the red indicator light on the control box 6 lights up, and the operator can operate the working platform 02 to rise and fall freely.

[0033] The present invention can support the working platform in the case of the failure of the hydraulic system of the lift truck, achieving the effect of double support and double protection of machinery and hydraulics during the high-altitude operation of the hydraulic lift truck. It has the advantages of simple structure, safety and reliability, and convenient operation, and is more suitable for the use of front-line production personnel.

[0034] The scope of protection required by the present invention is not limited to the above embodiments, but should also include other obvious transformations and alternative solutions to the present invention.

Claims

1. An anti-falling safety protection device for a hydraulic lift truck. The hydraulic lift truck includes a vehicle body, a telescopic arm, and a working platform that are sequentially connected from bottom to top. A movable hinge pin shaft is provided at the bottom of the telescopic arm, and the movable hinge pin shaft can move horizontally along the vehicle body to lift the working platform by the telescopic arm. It is characterized in that: The anti-fall safety protection device is installed on the vehicle body, and includes a bracket, a long rack, a short rack, a guide sleeve, a telescopic electric cylinder and a button box; The connecting bracket is fixed to the vehicle body, the long rack is horizontally arranged on the vehicle body, and an engaging tooth is provided on the upper surface, one end of the long rack is fixedly connected to the movable hinge pin and can move horizontally with the movable hinge pin, the short rack is arranged above the long rack in parallel, and an engaging tooth is provided on the lower surface that can mesh with the engaging tooth of the long rack, the guide sleeve is connected between the connecting bracket and the short rack to constrain and guide the vertical movement of the short rack, the guide sleeve includes a guide shaft and a guide sleeve that slide with each other, the guide shaft is fixed on the short rack and can slide up and down in the guide sleeve, the guide sleeve is vertically fixed on the connecting bracket, the upper end of the telescopic electric cylinder is fixedly connected to the connecting bracket, and the lower end is fixedly connected to the short rack and drives the short rack to move up and down, the button box is arranged on the working platform, is electrically connected to the telescopic electric cylinder and controls the retraction and extension movement of the telescopic electric cylinder; The button box controls the extension of the telescopic electric cylinder and pushes the short rack downward, so that the meshing teeth of the short rack and the long rack mesh with each other, thereby limiting the horizontal movement of the long rack, and then locking the movable articulated shaft and the telescopic arm. The gravity of the working platform exerted on the telescopic arm is transmitted to the connecting bracket fixed on the vehicle body through the long rack and the short rack, so that the working platform can be stably stopped at its original position in the air to prevent the working platform from falling due to a hydraulic system failure.

2. The anti-falling safety protection device for a hydraulic lift truck according to claim 1, characterized in that: The meshing teeth of the short rack and the long rack are trapezoidal straight teeth.

3. The anti-falling safety protection device for a hydraulic lift truck according to claim 1, characterized in that: The connecting bracket is provided with a limit switch for limiting the travel of the telescopic electric cylinder and the short rack.

4. The anti-falling safety protection device for a hydraulic lift truck according to claim 1, wherein: The rated voltage of the telescopic electric cylinder is DCV, the maximum speed is 10 mm / S, and the maximum stroke is 30 mm.

5. The anti-falling safety protection device for a hydraulic lift truck according to claim 1, characterized in that: The button box comprises an ascending button, a descending button and an indicator light. When the indicator light is on, it indicates that the anti-falling safety protection device is not effective.

6. The anti-falling safety protection device for a hydraulic lift truck according to claim 1, characterized in that: The number of the anti-falling safety protection devices is two sets, which are respectively installed on the front and rear sides of the body of the hydraulic lifting vehicle.

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