Speed regulating mechanism for graded descending of forklift

Abstract

The utility model discloses a speed regulating mechanism for graded descending of a forklift, which comprises an oil supply unit comprising a main oil supply path, a first branch oil path, a second branch oil path and an oil pump, and the first branch oil path and the second branch oil path are simultaneously communicated with the oil pump; according to the oil supply unit, when the pallet fork descends between the first height and the second height, the first branch oil way communicates with the main oil supply way, the second branch oil way is disconnected from the main oil supply way, and when the pallet fork descends between the second height and the third height, the first branch oil way and the second branch oil way communicate with the main oil supply way at the same time. According to the utility model, by connecting or disconnecting the second branch oil path, changing the oil flow rate in the main oil supply path and adjusting the contraction speed of the first driving oil cylinder and the second driving oil cylinder, the descending speeds of the pallet fork in two stages are equal, so that the descending speeds of the pallet fork in the two stages are equal, and the safety and the stability of the forklift are improved.

Description

Technical Field

[0001] The utility model relates to the technical field of forklifts, in particular to a speed regulating mechanism for graded descent of a forklift. Background Art

[0002] A forklift is a tool used to transport goods. The forklift is equipped with a liftable fork. Goods can be picked up by the fork. The lifting of the fork can drive the goods on the fork to rise and fall, so as to complete the picking and placing of goods.

[0003] Among them, the lifting height of the fork itself is limited. When the fork rises to the maximum height, the fork can be driven to continue to rise through the mast to increase the maximum lifting height of the fork. However, such a design brings a defect: that is, the descent of the fork has a first stage and a second stage. In the first stage, the mast drives the fork to descend together. At this time, the total gravity of the mast, the fork and / or the goods on the fork does work, and the descent speed is faster; in the second stage, the mast no longer descends, and the fork descends alone. At this time, the gravity of the fork and / or the goods on the fork makes its descent speed slower than that of the first stage.

[0004] It can be seen that there are two stages with different speeds in the descending process of the fork. The fork descends faster in the first stage and slower in the second stage. The speed difference in different stages has an adverse effect on the safety and stability of the goods. Summary of the invention

[0005] In view of the above-mentioned deficiencies in the prior art, the technical problem to be solved by the present invention is to propose a speed regulating mechanism for the graded descent of a forklift, so as to solve the problems in the prior art of reduced safety and stability caused by speed differences when the forks of the forklift descend at different stages.

[0006] The utility model solves the technical problem by adopting a technical solution that is a speed regulating mechanism for graded descent of a forklift, the forklift comprising: a mast and a fork, the mast comprising a fixed frame and a sliding frame, the sliding frame being movable relative to the fixed frame in a height direction, the fork being arranged on the sliding frame and being movable relative to the sliding frame in a height direction; a first driving oil cylinder for driving the sliding frame to rise and fall and a second driving oil cylinder for driving the fork to rise and fall; a first height, a second height and a third height are marked in sequence along the descending direction of the fork, when the fork is between the first height and the second height, the first driving oil cylinder is extended and retracted to drive the fork to rise and fall; when the fork is between the second height and the third height, the second driving oil cylinder is extended and retracted to drive the fork to rise and fall, the speed regulating mechanism comprising:

[0007] The oil supply unit comprises a main oil supply oil circuit, the first driving oil cylinder and the second driving oil cylinder are connected to the main oil supply oil circuit at the same time; a first branch oil circuit, a second branch oil circuit and an oil pump, the first branch oil circuit and the second branch oil circuit are connected to the oil pump at the same time;

[0008] The oil supply unit is configured such that when the fork is lowered between a first height and a second height, the first branch oil passage is connected to the main oil supply passage, and the second branch oil passage is disconnected from the main oil supply passage, and when the fork is lowered between the second height and a third height, the first branch oil passage and the second branch oil passage are simultaneously connected to the main oil supply passage.

[0009] Furthermore, a solenoid valve is provided on the second oil branch circuit, and the solenoid valve is used to connect or disconnect the second oil branch circuit and the main oil supply circuit.

[0010] Furthermore, it also includes a control unit, which includes a PLC chip, and the PLC chip is used to control the opening and closing of the solenoid valve.

[0011] Furthermore, a sensor unit is provided, and the sensor unit is used to send a signal to the PLC chip to open the solenoid valve when the fork is at the second height.

[0012] Furthermore, the sensing unit includes a first sensing element and a second sensing element, the first sensing element is at a second height and is fixedly connected to the fixing frame, and the second sensing element is fixedly connected to the sliding frame.

[0013] Furthermore, a second throttle valve is provided on the second oil branch line.

[0014] Furthermore, a first throttle valve is provided on the first oil branch line.

[0015] Compared with the prior art, the utility model has at least the following beneficial effects:

[0016] By connecting or disconnecting the second branch oil circuit, the oil flow rate in the main oil supply circuit is changed, and the contraction speed of the first driving cylinder and the second driving cylinder is adjusted, so that the speed of the fork when descending in the two stages is equal, and the speed of the fork when descending in the two stages is equal, thereby improving the safety and stability of the forklift. BRIEF DESCRIPTION OF THE DRAWINGS

[0017] Figure 1 It is a schematic diagram of the structure of the gantry and the fork in the embodiment;

[0018] Figure 2 Schematic diagram of the oil circuit of the speed regulating mechanism in the embodiment;

[0019] In the figure:

[0020] 100. fixing frame; 110. sensing unit;

[0021] 200, sliding frame; 210, first driving cylinder;

[0022] 300, cargo fork; 310, second driving cylinder;

[0023] 400, main oil supply circuit; 410, first branch oil circuit; 411, first throttle valve; 420, second branch oil circuit; 421, second throttle valve; 422, solenoid valve. DETAILED DESCRIPTION

[0024] The following are specific embodiments of the present invention and the accompanying drawings to further describe the technical solution of the present invention, but the present invention is not limited to these embodiments.

[0025] Please refer to Figure 1-Figure 2 The utility model discloses a speed regulating mechanism for graded descent of a forklift, the forklift comprising: a gantry and a fork 300, the gantry comprising a fixed frame 100 and a sliding frame 200, the sliding frame 200 being movable in a height direction relative to the fixed frame 100, the fork 300 being arranged on the sliding frame 200 and being movable in a height direction relative to the sliding frame 200; a first driving oil cylinder 210 for driving the sliding frame 200 to rise and fall, and a second driving oil cylinder 310 for driving the fork 300 to rise and fall; a first height, a second height and a third height are marked in sequence along the descending direction of the fork 300, when the fork 300 is between the first height and the second height, the first driving oil cylinder 210 is extended and retracted to drive the fork 300 to rise and fall; when the fork 300 is between the second height and the third height, the second driving oil cylinder 310 is extended and retracted to drive the fork 300 to rise and fall, the speed regulating mechanism comprising:

[0026] The oil supply unit includes a main oil supply circuit 400, the first driving cylinder 210 and the second driving cylinder 310 are connected to the main oil supply circuit 400; a first branch oil circuit 410, a second branch oil circuit 420 and an oil pump, the first branch oil circuit 410 and the second branch oil circuit 420 are connected to the oil pump;

[0027] The oil supply unit is configured such that when the fork 300 is lowered between the first height and the second height, the first branch oil passage 410 is connected to the main oil supply passage 400, and the second branch oil passage 420 is disconnected from the main oil supply passage 400; when the fork 300 is lowered between the second height and the third height, the first branch oil passage 410 and the second branch oil passage 420 are simultaneously connected to the main oil supply passage 400.

[0028] It should be noted that, between the first position and the second position, the shelf (including the goods on the fork 300) and the sliding frame 200 descend together, and the overall gravity is relatively large during this process, so the descending speed is relatively fast; between the second position and the third position, the sliding frame 200 has descended to the lowest position, and the fork 300 descends alone. During this process, the overall gravity is relatively small, so the descending speed is relatively slow.

[0029] In order to make the descending speed of the two stages equal, the oil supply unit in this embodiment is set as the main oil supply circuit 400 to supply oil to the first driving cylinder 210 and the second driving cylinder 310 at the same time, and two branch oil circuits (namely the first branch oil circuit 410 and the second branch oil circuit 420) are set between the main oil supply circuit 400 and the oil pump.

[0030] Specifically, when the sliding frame 200 and the fork 300 are lowered together, the second oil branch 420 is disconnected, and only the first oil branch 410 is connected to the main oil supply oil circuit 400. Then, the oil flow rate in the main oil supply oil circuit 400 is slow, and the speed of contraction of the first driving oil cylinder 210 is reduced, thereby slowing down the speed of the sliding frame 200 and the fork 300 when they are lowered together; when the fork 300 is lowered alone, the first oil branch 410 and the second oil branch 420 are connected at the same time, then the oil flow rate in the main oil supply oil circuit 400 is fast, and the second driving oil cylinder 310 contracts faster. In this way, by connecting or disconnecting the second oil branch 420, the oil flow rate in the main oil supply oil circuit 400 is changed, and the contraction speed of the first driving oil cylinder 210 and the second driving oil cylinder 310 is adjusted, so that the speed of the fork 300 when it is lowered in the two stages is equal, and the speed of the fork 300 when it is lowered in the two stages is the same, thereby improving the safety and stability of the forklift.

[0031] Furthermore, a solenoid valve 422 is provided on the second oil branch circuit 420 , and the solenoid valve 422 is used to connect or disconnect the second oil branch circuit 420 and the main oil supply circuit 400 .

[0032] Specifically, by opening or closing the solenoid valve 422, the connection between the second branch oil circuit 420 and the main oil supply circuit 400 can be connected or disconnected, thereby changing the flow rate in the main oil supply circuit 400 and adjusting the retraction speed of the driving cylinder to achieve the purpose of adjusting the descending speed of the fork 300.

[0033] Furthermore, a sensor unit 110 is provided, and the sensor unit 110 is used to send a signal to the PLC chip to open the solenoid valve 422 when the fork 300 is at the second height.

[0034] The sensor unit 110 includes a first sensor and a second sensor. The first sensor is located at a second height and is fixed to the fixed frame 100 , and the second sensor is fixed to the sliding frame 200 .

[0035] It also includes a control unit, which includes a PLC chip. The PLC chip is used to control the opening and closing of the solenoid valve 422.

[0036] Specifically, when the sliding frame 200 drives the fork 300 to descend from the first position to the second position, the second sensor on the sliding frame 200 is at the same height and aligned with the first sensor. At this time, the first sensor or the second sensor sends a signal to the PLC chip. After receiving the signal, the PLC chip controls the solenoid valve 422 to open and connect the second oil branch circuit 420. Then the fork 300 continues to descend at the same speed. During the process of the fork 300 continuing to descend, the position of the sliding frame 200 no longer changes, so the first sensor and the second sensor are always aligned, and the sensor unit 110 no longer sends a signal.

[0037] Furthermore, a first throttle valve 411 is provided on the first oil branch path 410 , and a second throttle valve 421 is provided on the second oil branch path 420 .

[0038] Specifically, by adjusting the first throttle valve 411, the flow rate of the first oil path 410 can be controlled, thereby adjusting the descending speed of the fork 300 between the first position and the second position; by the second throttle valve 421, the flow rate of the second oil path 420 can be controlled, thereby adjusting the speed at which the fork 300 descends from the second position to the third position. That is, by adjusting the throttle valves on the two oil paths, the descending speed of the fork 300 at different stages can be adjusted, so that the fork 300 can descend at a uniform speed at different stages. Of course, by adjusting the two throttle valves, the fork 300 can also be made to descend at a uniform speed at different speeds.

[0039] It should be noted that all directional indications in the embodiments of the present invention (such as up, down, left, right, front, back...) are only used to explain the relative position relationship, movement status, etc. between the components under a certain specific posture (as shown in the accompanying drawings). If the specific posture changes, the directional indication will also change accordingly.

[0040] In addition, in the present invention, the descriptions of "first", "second", "one", etc. are only used for descriptive purposes and cannot be understood as indicating or implying their relative importance or implicitly indicating the number of the indicated technical features. Therefore, the features defined as "first" or "second" may explicitly or implicitly include at least one of the features. In the description of the present invention, the meaning of "plurality" is at least two, such as two, three, etc., unless otherwise clearly and specifically defined.

[0041] In the present invention, unless otherwise clearly specified and limited, the terms "connection", "fixation", etc. should be understood in a broad sense. For example, "fixation" can be a fixed connection, a detachable connection, or an integral connection; it can be a mechanical connection or an electrical connection; it can be a direct connection or an indirect connection through an intermediate medium, it can be the internal connection of two elements or the interaction relationship between two elements, unless otherwise clearly defined. For ordinary technicians in this field, the specific meanings of the above terms in the present invention can be understood according to specific circumstances.

[0042] In addition, the technical solutions between the various embodiments of the present invention can be combined with each other, but it must be based on the fact that ordinary technicians in the field can implement it. 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.

Claims

1. A speed regulating mechanism for graded descent of a forklift, the forklift comprising: A gantry and a fork, wherein the gantry comprises a fixed frame and a sliding frame, the sliding frame can move in the height direction relative to the fixed frame, the fork is arranged on the sliding frame and can move in the height direction relative to the sliding frame; a first driving cylinder for driving the sliding frame to rise and fall and a second driving cylinder for driving the fork to rise and fall; a first height, a second height and a third height are marked in sequence along the descending direction of the fork, when the fork is between the first height and the second height, the first driving cylinder is extended and retracted to drive the fork to rise and fall; when the fork is between the second height and the third height, the second driving cylinder is extended and retracted to drive the fork to rise and fall, characterized in that the speed regulating mechanism comprises: The oil supply unit comprises a main oil supply oil circuit, the first driving oil cylinder and the second driving oil cylinder are connected to the main oil supply oil circuit at the same time; a first branch oil circuit, a second branch oil circuit and an oil pump, the first branch oil circuit and the second branch oil circuit are connected to the oil pump at the same time; The oil supply unit is configured such that when the fork is lowered between a first height and a second height, the first branch oil passage is connected to the main oil supply passage, and the second branch oil passage is disconnected from the main oil supply passage, and when the fork is lowered between the second height and a third height, the first branch oil passage and the second branch oil passage are simultaneously connected to the main oil supply passage.

2. A speed regulating mechanism for graded descent of a forklift according to claim 1, characterized in that: The second oil branch circuit is also provided with an electromagnetic valve, and the electromagnetic valve is used to connect or disconnect the second oil branch circuit and the main oil supply circuit.

3. A speed regulating mechanism for graded descent of a forklift according to claim 2, characterized in that: It also includes a control unit, which includes a PLC chip, and the PLC chip is used to control the opening and closing of the solenoid valve.

4. A speed regulating mechanism for graded descent of a forklift according to claim 3, characterized in that: A sensor unit is also provided, and the sensor unit is used to send a signal to the PLC chip to open the solenoid valve when the fork is at the second height.

5. The speed regulating mechanism for graded descent of a forklift according to claim 4, characterized in that: The sensor unit includes a first sensor and a second sensor. The first sensor is at a second height and is fixed to the fixed frame, and the second sensor is fixed to the sliding frame.

6. The speed regulating mechanism for graded descent of a forklift according to claim 1, characterized in that: A second throttle valve is also provided on the second oil branch line.

7. The speed regulating mechanism for graded descent of a forklift according to claim 1, characterized in that: A first throttle valve is also provided on the first oil branch line.

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