Lifting valve rod position detection mechanism, hydraulic lifting control device and forklift

Abstract

The lifting valve rod position detection mechanism comprises a control valve and a voltage change output unit, the control valve is provided with a lifting valve rod used for controlling lifting, and a shell of the voltage change output unit and a valve body of the control valve are relatively fixed. The movable part of the voltage change output unit is connected with a lifting valve rod of the control valve through a linkage structure, so that the movable part of the voltage change output unit generates displacement along with the position change of the lifting valve rod, and the voltage change output unit outputs a voltage value related to the displacement change. The voltage change output unit is used for detecting the position of the lifting valve rod, whether the lifting valve rod is in a working position or a middle position or not can be detected, and safety risks caused by misoperation can be reduced. The rotating speed signal can be provided for the pump motor by using the linearly changing voltage value output by the voltage change output unit, so that the rotating speed of the pump motor is linearly changed along with the position change of the lifting valve rod, and the energy consumption is favorably reduced.

Description

Technical Field

[0001] The utility model relates to the technical field of forklifts, in particular to a lifting valve stem position detection mechanism and a hydraulic lifting control device. Background Art

[0002] At present, most of the forklifts with front-mounted control valves in the prior art use a triggering microswitch to detect the position of the lifting valve stem of the control valve, so as to provide a speed signal to the pump motor, so that the pump motor works and the mast is lifted. The mast is lowered by its own weight, and the pump motor does not work. Specifically, when the lifting valve stem of the control valve is in the lifting working position, the microswitch will be triggered. When the control valve is in the middle position or the lowering working position, the microswitch cannot be triggered. However, the above method has the following shortcomings: the microswitch can only provide a switch signal, and after being triggered, the motor can achieve the maximum speed output, which will result in high system energy consumption and high hydraulic oil temperature. In addition, the use of a microswitch cannot detect whether the lifting valve stem is in the middle position. If the operating lever is triggered by an erroneous operation, there is a safety hazard. Utility Model Content

[0003] The utility model aims at the technical problems existing in the prior art and provides a lifting valve stem position detection mechanism, a hydraulic lifting control device and a forklift.

[0004] The technical solution adopted by the utility model to solve its technical problems is: a lifting valve stem position detection mechanism, including a control valve, the control valve has a lifting valve stem for controlling lifting; it is characterized in that: it also includes a voltage change output unit, the shell of the voltage change output unit is relatively fixed to the valve body of the control valve, the active part of the voltage change output unit is connected to the lifting valve stem of the control valve through a linkage structure, so that the active part of the voltage change output unit is displaced as the position of the lifting valve stem changes, and the voltage change output unit outputs a voltage value related to the displacement change.

[0005] Furthermore, the linkage structure includes an operating rod connected to the lifting valve stem and a transmission member connected to the operating rod. The movable part of the voltage change output unit is connected to the transmission member and can move with the operating rod along the length direction of the operating rod.

[0006] Furthermore, the transmission member is a fixed plate, which is fixedly mounted on the operating rod and is perpendicular to the operating rod; the tail end of the active part of the voltage change output unit faces downward.

[0007] Furthermore, the voltage change output unit is a potentiometer, a rheostat or a displacement sensor.

[0008] Furthermore, the voltage change output unit is mounted on a bracket, which is mounted on the frame of the forklift; the bracket is L-shaped, with its vertical side connected to the frame and its horizontal side mounted with the voltage change output unit.

[0009] Furthermore, when the lifting valve stem is in a neutral position, the voltage value output by the voltage change output unit is an initial voltage value.

[0010] The utility model further provides a hydraulic lifting control device, including a pump motor and a controller, and also includes a lifting valve stem position detection mechanism as described in the utility model above, the controller is connected to the pump motor and a voltage change output unit, and the controller controls the speed of the pump motor according to the voltage value transmitted by the voltage change output unit.

[0011] Furthermore, it also includes an alarm, which is connected to the controller so that when the voltage value output by the voltage change output unit is the voltage value corresponding to the lifting valve stem being in the middle position, the controller controls the alarm to release the alarm.

[0012] Furthermore, it also includes an oil pump, a lifting cylinder, and an oil tank. The control valve has an oil inlet channel, an oil outlet channel, and an oil return channel for controlling the lifting. The pump motor provides a rotation speed to the oil pump. The oil inlet of the oil pump is connected to the oil tank, the oil outlet of the oil pump is connected to the oil inlet channel, the oil outlet channel is connected to the hydraulic chamber of the lifting cylinder, and the oil return channel is connected to the oil tank.

[0013] The utility model further provides a forklift, comprising the hydraulic lifting control device as described in the utility model.

[0014] Compared with the prior art, the utility model has the following beneficial effects:

[0015] 1. The utility model uses a voltage change output unit instead of a micro switch to detect the position of the lift valve stem. The active part of the voltage change output unit is displaced as the position of the lift valve stem changes, and the voltage change output unit outputs a voltage value related to the displacement change, so that the utility model can not only detect whether the lift valve stem is in the working position, but also detect whether the lift valve stem is in the middle position, which is conducive to reducing the safety risks caused by misoperation. In addition, the utility model can use the linearly changing voltage value output by the voltage change output unit to provide a speed signal to the pump motor, so that the speed of the pump motor changes linearly with the position of the lift valve stem, thereby helping to reduce energy consumption.

[0016] 2. The linkage structure includes an operating rod connected to the lifting valve stem and a transmission member connected to the operating rod. The sensing rod of the potentiometer is arranged parallel to the operating rod, and the tail end of the sensing rod is connected to the transmission member, so that the linkage structure is very simple and easy to assemble.

[0017] 3. The voltage change output unit is installed on the frame of the forklift using a bracket, making the voltage change output unit easy to install.

[0018] The present invention will be further described in detail below in conjunction with the accompanying drawings and embodiments; however, the lift valve stem position detection mechanism, hydraulic lift control device and forklift of the present invention are not limited to the embodiments. BRIEF DESCRIPTION OF THE DRAWINGS

[0019] Figure 1 This is a schematic diagram of the structure of the utility model Figure 1 ;

[0020] Figure 2 yes Figure 1 A magnified schematic diagram of part A;

[0021] Figure 3 This is a schematic diagram of the structure of the utility model Figure 2 ;

[0022] In the figure, 1. control valve, 11. lifting valve stem, 2. potentiometer, 21. sensing rod, 3. operating rod, 4. fixing plate, 5. bracket, 6. frame. DETAILED DESCRIPTION

[0023] In the present invention, the directions or positional relationships indicated by "upper" and "lower" are based on the directions or positional relationships shown in the drawings, which are only for the convenience of describing the present invention, and do not indicate or imply that the device referred to must have a specific direction, be constructed and operated in a specific direction, and therefore cannot be understood as limiting the scope of protection of the present invention. For ordinary technicians in this field, the specific meanings of the above terms in this application can be understood according to specific circumstances.

[0024] In addition, in the description of the present invention, unless otherwise clearly specified and limited, the terms "installation", "connection", etc. should be understood in a broad sense. For example, "connection" 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 components. For ordinary technicians in this field, the specific meanings of the above terms in the present invention can be understood according to specific circumstances.

[0025] See also Figure 1-Figure 3As shown, a lift valve stem position detection mechanism of the utility model includes a control valve 1, which can also be called a multi-way valve, and has a lift valve stem 11 for controlling lifting. The utility model also includes a voltage change output unit, the housing of the voltage change output unit is relatively fixed to the valve body of the control valve 1, and the active part of the voltage change output unit is connected to the lift valve stem 11 of the control valve 1 through a linkage structure, so that the active part of the voltage change output unit is displaced as the position of the lift valve stem 11 changes, and the voltage change output unit outputs a voltage value related to the displacement change. Therefore, the utility model uses a voltage change output unit to detect whether the lift valve stem 11 of the control valve 1 is in a working position or a neutral position. In this embodiment, the linkage structure includes an operating rod 3 connected to the lift valve stem 11 and a transmission member connected to the operating rod 3, and the active part of the voltage change output unit is connected to the transmission member, and can move with the operating rod 3 along the length direction of the operating rod 3. Specifically, the transmission member is a fixed plate 4, which is fixedly mounted on the operating rod 3 and is perpendicular to the operating rod 3.

[0026] In this embodiment, the voltage change output unit is a potentiometer 2, and the movable part is the sensing rod 21 of the potentiometer 2, the sensing rod 21 is parallel to the operating rod 3, and the tail end of the sensing rod 21 faces the valve body of the control 1 and is connected to the above-mentioned fixing plate 4. In other embodiments, the voltage change output unit is a rheostat or a displacement sensor, when the voltage change output unit is a rheostat, the movable part is the slider of the rheostat; when the voltage change output unit is a displacement sensor, the movable part is the movable brush of the displacement sensor.

[0027] In this embodiment, the voltage change output unit (i.e., the potentiometer 2) is mounted on a bracket 5, and the bracket 5 is mounted on the frame 6 of the forklift. Specifically, the bracket 5 is L-shaped, and its vertical side is connected to the frame 6, and its horizontal side is mounted with the potentiometer 2. The housing of the potentiometer 2 is specifically connected to the bracket 5 using a plurality of bolt assemblies, and the bracket 5 is also connected to the frame 6 of the forklift using a plurality of bolt assemblies, and the bolt assembly includes bolts and nuts matched therewith.

[0028] The utility model discloses a hydraulic lifting control device, including a pump motor, an oil pump, a lifting cylinder, an oil tank and a controller. The pump motor provides a rotation speed for the oil pump, and the oil inlet of the oil pump is connected to the oil tank. The utility model also includes a lifting valve stem position detection mechanism as described above. The control valve 1 has an oil inlet channel, an oil outlet channel and an oil return channel for controlling lifting. The oil outlet of the oil pump is connected to the oil inlet channel, the oil outlet channel is connected to the hydraulic chamber of the lifting cylinder, and the oil return channel is connected to the oil tank. The controller connects the pump motor and a voltage change output unit (i.e., a potentiometer 2), and the controller controls the rotation speed of the pump motor according to the voltage value transmitted by the potentiometer 2.

[0029] The utility model also includes an alarm, which is connected to the controller, so that when the voltage value output by the potentiometer 2 is the voltage value corresponding to when the lifting valve stem 11 is in the middle position, the controller controls the alarm to release the alarm.

[0030] The working principle of the utility model is as follows:

[0031] When the lift valve stem 11 is in the middle position, the voltage value output by the potentiometer 2 is set to the initial voltage value. When the operating rod 3 is pulled upward, the lift valve stem 11 moves upward to the working position driven by the operating rod. During this process, the fixed plate 4 on the operating rod 3 pushes the sensing rod 21 of the potentiometer 2 to move in the contraction direction, so that the potentiometer 2 outputs a corresponding voltage value through the displacement change of the sensing rod 21 as the speed signal of the pump motor, that is, the controller controls the speed of the pump motor according to the voltage value output by the potentiometer 2. Since the potentiometer 2 can provide a linearly changing voltage value, the speed of the pump motor can be linearly changed with the displacement of the lift valve stem 11.

[0032] When the lifting valve stem 11 is not in the middle position, the sensing rod 21 of the potentiometer 2 will have a certain displacement relative to the initial position, causing a change in the voltage value of the potentiometer 2. If the current voltage value output by the potentiometer 2 is different from the initial voltage value, the controller can determine that the lifting rod of the control valve 1 is not in the middle position, and control the alarm to sound, and stop the hydraulic action of the entire vehicle. After the lifting valve stem 11 returns to the middle position, the alarm is controlled to be cleared. This can prevent safety risks caused by improper operation of the operating rod 3.

[0033] The utility model uses a potentiometer 2 instead of a micro switch to detect the position of the lift valve stem 11, which can not only detect whether the lift valve stem 11 of the control valve 1 is in the working position, but also detect whether the lift valve stem 11 of the control valve 1 is in the middle position, which is conducive to reducing the safety risks caused by misoperation. In addition, the utility model can use the linearly changing voltage value output by the potentiometer 2 to provide a speed signal to the pump motor, so that the speed of the pump motor can change linearly with the position change of the lift valve stem 11, which is more energy-saving.

[0034] The potentiometer 2 of the utility model is easy to install and has wide applicability, and is applicable to most forklifts currently having a front-mounted control valve 1 .

[0035] A forklift of the utility model comprises the hydraulic lifting control device of the utility model as described above.

[0036] The utility model provides a lifting valve stem position detection mechanism and a hydraulic lifting control device, and the uninvolved parts are the same as the prior art or can be implemented by using the prior art.

[0037] The above embodiments are only used to further illustrate a lifting valve stem position detection mechanism, a hydraulic lifting control device and a forklift of the utility model, but the utility model is not limited to the embodiments. Any simple modifications, equivalent changes and modifications made to the above embodiments based on the technical essence of the utility model fall within the protection scope of the technical solution of the utility model.

Claims

1. A lifting valve stem position detection mechanism, comprising a control valve, the control valve having a lifting valve stem for controlling lifting; characterized in that: It also includes a voltage change output unit, the shell of which is relatively fixed to the valve body of the control valve, and the movable part of the voltage change output unit is connected to the lifting valve stem of the control valve through a linkage structure, so that the movable part of the voltage change output unit is displaced as the position of the lifting valve stem changes, and the voltage change output unit outputs a voltage value related to the displacement change.

2. The lifting valve stem position detection mechanism according to claim 1, characterized in that: The linkage structure includes an operating rod connected to the lifting valve stem and a transmission member connected to the operating rod. The movable part of the voltage change output unit is connected to the transmission member and can move with the operating rod along the length direction of the operating rod.

3. The lifting valve stem position detection mechanism according to claim 2, characterized in that: The transmission member is a fixed plate, which is fixedly mounted on the operating rod and is perpendicular to the operating rod.

4. The lift valve stem position detection mechanism according to claim 1, characterized in that: The voltage change output unit is a potentiometer, a variable resistor or a displacement sensor.

5. The lift valve stem position detection mechanism according to claim 1, characterized in that: The voltage change output unit is installed on a bracket, and the bracket is installed on the frame of the forklift; the bracket is L-shaped, with its vertical side connected to the frame and its horizontal side installed with the voltage change output unit.

6. The lift valve stem position detection mechanism according to claim 1, characterized in that: When the lifting valve stem is in the middle position, the voltage value output by the voltage change output unit is an initial voltage value.

7. A hydraulic lifting control device, comprising a pump motor and a controller, characterized in that: It also includes a lifting valve stem position detection mechanism as described in any one of claims 1-6, the controller is connected to the pump motor and the voltage change output unit, and the controller controls the speed of the pump motor according to the voltage value transmitted by the voltage change output unit.

8. The hydraulic lifting control device according to claim 7, characterized in that: It also includes an alarm connected to the controller so that when the voltage value output by the voltage change output unit is the voltage value corresponding to when the lifting valve stem is in the middle position, the controller controls the alarm to release the alarm.

9. The hydraulic lifting control device according to claim 7, characterized in that: It also includes an oil pump, a lifting cylinder, and an oil tank. The control valve has an oil inlet channel, an oil outlet channel, and an oil return channel for controlling lifting. The pump motor provides a rotation speed to the oil pump. The oil inlet of the oil pump is connected to the oil tank, the oil outlet of the oil pump is connected to the oil inlet channel, the oil outlet channel is connected to the hydraulic chamber of the lifting cylinder, and the oil return channel is connected to the oil tank.

10. A forklift, characterized in that: It comprises a hydraulic lifting control device as described in any one of claims 7 to 9.

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