CN117945310A - Control method and system for forklift working device - Google Patents

Abstract

The invention discloses a control method and a system of a forklift working device, which relate to the field of hydraulic control, and when a first flow is smaller than a preset value, a second flow of oil output by a power source is larger than the first flow, and the oil flow at the input side of an electric proportional valve is larger than the oil flow at the output side, so that the situations of unstable action, shaking and the like of the electric proportional valve caused by the lack of flow under the condition of small oil flow are avoided; when the first flow is larger than a preset value, the third flow of the oil output by the power source is smaller than the first flow, so that the speed of the electric proportional valve for conveying the oil to the working device is improved, and energy consumption is avoided; the matching relation between the flow of the electric proportional valve and the flow of the oil provided by the power source is ensured by the first corresponding relation between the flow of the oil output by the preset power source and the opening of the electric proportional valve, the inching performance and the speed regulation performance of the electric proportional valve are improved, the vibration and the noise are reduced, the accurate control of the electric proportional valve is realized, the energy loss of the whole system is reduced, and the energy and the emission are saved.

Description

Control method and system for forklift working device

Technical Field

The invention relates to the field of hydraulic control, in particular to a control method and a system of a forklift working device.

Background

The operation processes of lifting, tilting and the like of a portal frame are realized by adopting mechanical multi-way valve control of a portal frame device and the like in the forklift industry, and a few forklifts adopt electric proportional valves to control and realize the operation processes of various operation devices, a power source outputs oil required by the operation of the operation devices to the input side of the electric proportional valves, and then the oil is output to the operation devices through the electric proportional valves so as to drive the operation devices to operate. However, the control system of the current working device cannot accurately control the electric proportional valve, so that effective control of the power source and the electric proportional valve matched with each other is difficult to realize, and the problems of energy loss, poor inching performance, action lag, inaccuracy and the like caused by mismatching of the oil output flow corresponding to the electric proportional valve and the oil output flow output from the power source to the electric proportional valve often occur.

Disclosure of Invention

The invention aims to provide a control method and a system for a forklift working device, which ensure the matching relation between the flow of an electric proportional valve and the flow of oil provided by a power source through a first corresponding relation between the flow of oil output by the power source and the opening of the electric proportional valve, improve the inching performance and the speed regulation performance of the electric proportional valve, reduce vibration and noise, realize the accurate control of the electric proportional valve, reduce the energy loss of the whole system, save energy and reduce emission.

In order to solve the technical problems, the invention provides a control method of a forklift working device, which is applied to a controller in a control system of the forklift working device, and comprises the following steps:

Receiving a target action signal of the working device, and determining a target opening of the electric proportional valve corresponding to the target action signal;

Determining a first flow corresponding to the target opening degree, and judging whether the first flow is larger than a preset value or not;

if not, determining a second flow of the oil output by the power source based on a first corresponding relation between the preset oil output by the power source and the opening of the electric proportional valve and the target opening; the second flow rate is greater than the first flow rate;

If yes, determining a third flow of the oil output by the power source based on a first corresponding relation between the preset oil output by the power source and the opening of the electric proportional valve and the target opening; the third flow rate is less than the first flow rate;

and controlling the power source to output oil to the electric proportional valve at the second flow rate or the third flow rate, and controlling the electric proportional valve to output oil to the working device at the first flow rate.

Optionally, the control method of the forklift working device further includes:

if the first flow is equal to the preset value, determining a fourth flow of the oil output by the power source based on a first corresponding relation between the preset oil output by the power source and the opening of the electric proportional valve and the target opening, wherein the fourth flow is equal to the first flow;

and controlling the power source to output oil to the electric proportional valve at the fourth flow rate, and controlling the electric proportional valve to output oil to the working device at the first flow rate.

Optionally, the control system of the forklift working device further includes a thumb switch, and the receiving the target action signal of the working device and determining the target opening of the electric proportional valve corresponding to the target action signal includes:

and determining a position signal of the thumb switch, and determining a target opening of the electric proportional valve corresponding to the position signal based on the position signal of the thumb switch.

Optionally, the determining the position signal of the thumb switch includes:

Acquiring a voltage signal output by the thumb switch;

A position signal of the thumb switch is determined based on a second correspondence of a position of the thumb switch to an output voltage.

Optionally, a voltage signal dead zone is provided at the neutral position and the maximum position of the thumb switch in the second correspondence of the position of the thumb switch to the output voltage.

Optionally, the controlling the electric proportional valve to output oil to the working device at the first flow rate includes:

Determining the current opening of the electric proportional valve and the current flow corresponding to the current opening;

And controlling the opening degree of the electric proportional valve to uniformly change from the current opening degree to the target opening degree according to a first preset speed, so that the output oil flow output by the electric proportional valve to the working device uniformly changes from the current flow to the first flow.

Optionally, the control method of the forklift working device further includes:

Determining the current opening of the electric proportional valve and the current flow corresponding to the current opening;

and when the target action signal of the working device is stopping action, controlling the opening degree of the electric proportional valve to uniformly change from the current opening degree to zero according to a second preset speed.

In order to solve the technical problem, the invention also provides a control system of the forklift working device, which comprises:

A memory for storing a computer program;

and the controller is used for realizing the steps of the control method of the forklift working device.

The invention provides a control method of a forklift working device, which comprises the steps of determining a target opening of an electric proportional valve, and determining a flow condition of output oil of a power source corresponding to the target opening by utilizing a first corresponding relation between the output oil flow of a preset power source and the opening of the electric proportional valve and the target opening; then controlling the electric proportional valve to output oil to the working device according to the target opening, and controlling the power source to output oil to the electric proportional valve according to the determined flow condition corresponding to the target opening; in the first corresponding relation, when the first flow corresponding to the target opening is smaller than a preset value, the second flow of the oil output by the power source is larger than the first flow, so that the oil flow of the input side of the electric proportional valve is larger than the oil flow of the output side, the electric proportional valve is prevented from working in a low flow state, and the conditions of unstable action, shaking and the like of the electric proportional valve caused by the low flow under the condition of small oil flow are avoided; when the first flow corresponding to the target opening is larger than a preset value, the third flow of the oil output by the power source is smaller than the first flow, so that the oil flow on the input side of the electric proportional valve is smaller than the oil flow on the output side, the speed of the electric proportional valve for conveying the oil to the working device is improved, and energy consumption is avoided; the matching relation between the flow of the electric proportional valve and the flow of the oil provided by the power source is ensured by the first corresponding relation between the flow of the oil output by the preset power source and the opening of the electric proportional valve, the inching performance and the speed regulation performance of the electric proportional valve are improved, the vibration and the noise are reduced, the accurate control of the electric proportional valve is realized, the energy loss of the whole system is reduced, and the energy and the emission are saved.

The invention also provides a control system of the forklift working device, which has the same beneficial effects as the control method of the forklift working device.

Drawings

In order to more clearly illustrate the technical solutions of the embodiments of the present invention, the drawings required in the prior art and the embodiments will be briefly described below, and it is apparent that the drawings in the following description are only some embodiments of the present invention, and other drawings may be obtained according to these drawings without inventive effort for a person skilled in the art.

Fig. 1 is a schematic flow chart of a control method of a forklift working device provided by the invention;

FIG. 2 is a schematic diagram showing the correspondence between the opening of a thumb switch and the output oil flow of an electric proportional valve and the output oil flow of a power source;

Fig. 3 is a schematic structural diagram of a control device of a forklift working device according to the present invention;

FIG. 4 is a schematic diagram showing the correspondence between a current signal received by an electro-proportional valve and a thumb switch position signal;

FIG. 5 is a schematic diagram showing the correspondence between the position signal of the thumb switch and the voltage signal outputted by the thumb switch according to the present invention;

FIG. 6 is a schematic diagram showing the position signal of a thumb switch according to the present invention over time;

Fig. 7 is a flow chart of a control method of another forklift working device provided by the invention;

Fig. 8 is a schematic structural diagram of a control device of another forklift working device according to the present invention;

fig. 9 is a schematic structural diagram of a control system of a forklift working device provided by the invention.

Detailed Description

The invention provides a control method and a control system for a forklift working device, which ensure the matching relation between the flow of an electric proportional valve and the flow of oil provided by a power source through a first corresponding relation between the flow of oil output by the power source and the opening of the electric proportional valve, improve the inching performance and the speed regulation performance of the electric proportional valve, reduce vibration and noise, realize the accurate control of the electric proportional valve, and simultaneously reduce the energy loss of the whole system, save energy and reduce emission.

For the purpose of making the objects, technical solutions and advantages of the embodiments of the present invention more apparent, the technical solutions of the embodiments of the present invention will be clearly and completely described below with reference to the accompanying drawings in the embodiments of the present invention, and it is apparent that the described embodiments are some embodiments of the present invention, but not all embodiments of the present invention. All other embodiments, which can be made by those skilled in the art based on the embodiments of the invention without making any inventive effort, are intended to be within the scope of the invention.

Referring to fig. 1, fig. 1 is a flow chart of a control method of a forklift working device according to the present invention; referring to fig. 2, fig. 2 is a schematic diagram showing a correspondence relationship between a thumb switch opening and an output oil flow of an electric proportional valve and an output oil flow of a power source according to the present invention; in order to solve the technical problems, the invention provides a control method of a forklift working device, which is applied to a controller in a control system of the forklift working device, and the control method of the forklift working device comprises the following steps:

S11: receiving a target action signal of a working device, and determining a target opening of an electric proportional valve corresponding to the target action signal;

It can be understood that the target action signal, that is, the signal instruction corresponding to the next operation that needs to be performed by the working device, is generally transmitted to the controller in an electrical signal manner, and the controller can directly determine the target opening of the electric proportional valve corresponding to the target action signal according to the received target action signal; the opening of the electric proportional valve, that is, the displacement distance of the valve core of the electric proportional valve, the difference of the opening of the electric proportional valve can control the output flow of the oil liquid output to the working device through the electric proportional valve, the process of determining the target opening by the controller can be correspondingly determined through the corresponding relation between the target action signal and the opening set in the construction process of the control system of the forklift working device, and the specific type, implementation mode of the target action signal and the corresponding relation between the target action signal and the opening of the electric proportional valve can be determined and adjusted according to practical application conditions.

Specifically, taking the operation speed of the electric proportional valve control portal device as an example, the operation process of the portal device is mainly driven by a portal operation oil cylinder, oil liquid required by the portal operation oil cylinder is oil, the opening of the electric proportional valve determines the flow rate of the oil output to the portal operation oil cylinder, the portal operation oil cylinder can control the portal device to generate operation processes with different speeds according to the oil with different flow rates, and under the condition, the corresponding relation between a target operation signal and the opening of the electric proportional valve, namely, the corresponding relation between the operation speed of the portal device and the opening of the electric proportional valve can be directly determined according to the types and specific working conditions of the portal operation oil cylinder and the electric proportional valve.

S12: determining a first flow corresponding to the target opening degree, and judging whether the first flow is larger than a preset value;

It is easy to understand that in the control process of the working device, not only the opening degree of the electric proportional valve is required to control the oil with different flow rates to be output to the working device, but also the power source is required to be controlled to provide the oil with different flow rates to the electric proportional valve, so that the power source in the application is a speed-adjustable power source, namely a power source supporting the output of the oil with different flow rates, and for the electric proportional valve, two flow rates exist, one is the energy supply flow rate of the power source, the other is the valve core opening of the electric proportional valve, namely the output flow rate corresponding to the output of the electric proportional valve to the working device, in the control process of the working device, the two flow rates are all variables, and the action condition of the working device and the working performance of the electric proportional valve can be influenced by the two flow rates and the mutual matching condition between the two flow rates.

In order to improve the working performance of the electric proportional valve, the controller needs to determine the flow condition of the oil corresponding to the target action of the working device, so that after determining the first flow corresponding to the target opening, the controller judges the specific value of the first flow, and compares the specific value with a preset value to determine whether the flow condition of the oil corresponding to the target action is in a small flow state or a large flow state, and in different flow states, the electric proportional valve needs to work in different states to ensure good working performance such as micropower. The specific values and implementation modes of the preset values are not particularly limited, and the preset values can be selected and adjusted according to practical application conditions, experiments and other modes.

S13: if not, determining a second flow of the oil output by the power source based on a first corresponding relation between the preset oil output by the power source and the opening of the electric proportional valve and the target opening; the second flow is greater than the first flow;

if the first flow is smaller than the preset value, it indicates that the flow condition of the oil corresponding to the target action is a small flow condition, and the small flow often causes the electric proportional valve to work in a low flow condition, so that the action of the electric proportional valve is unstable, and abnormal conditions such as jitter occur.

S14: if yes, determining a third flow of the oil output by the power source based on a first corresponding relation between the preset oil output by the power source and the opening of the electric proportional valve and the target opening; the third flow rate is smaller than the first flow rate;

If the first flow is greater than the preset value, the flow condition of the oil corresponding to the target action is indicated to be a large flow state, the electric proportional valve does not work in a low flow state under the large flow state, stable work can be achieved, at the moment, in order to improve the response speed to the control process of the working device, the electric proportional valve can be controlled to directly and rapidly output the large flow of the oil to rapidly control the working device to perform corresponding actions, in order to further avoid energy consumption, the electric proportional valve is convenient to timely output all the oil received by the input side to the working device, the power source does not need to provide the large flow of the oil to the electric proportional valve, only the third flow of the oil smaller than the first flow output by the electric proportional valve is required to be provided to reduce energy consumption, and therefore, under the condition that the first flow is greater than the preset value, the flow of the oil output by the power source is required to be set to be the third flow smaller than the first flow.

S15: and controlling the power source to output oil to the electric proportional valve at the second flow or the third flow, and controlling the electric proportional valve to output oil to the working device at the first flow.

In practical application, under the conditions of different target actions, namely different required flow rates, various matching modes of the corresponding power source output flow rate, the corresponding electric proportional valve output flow rate and the corresponding electric proportional valve opening degree can be directly and intuitively and clearly embodied in a mode of a first corresponding relation between the power source output oil flow rate and the electric proportional valve opening degree, the first corresponding relation between the preset power source output oil flow rate and the electric proportional valve opening degree is recorded into a controller in advance, and the controller directly controls the power source and the electric proportional valve to cooperate to realize the action process of the working device according to the first corresponding relation and the target action condition of the working device. The specific types and implementation modes of the electric proportional valve and the power source are not particularly limited, and when the oil is oil, the power source can comprise an oil pump motor and an oil pump, and can also be implemented in the form of power sources such as an engine.

As a specific embodiment, the thumb switch can be directly adopted to set each switch gear, each switch gear of the thumb switch corresponds to the opening of the electric proportional valve one by one, when a user operates the thumb switch to enable the thumb switch to work in different switch gears, the target action signal is a voltage signal corresponding to the switch gear output by the thumb switch, the target opening of the electric proportional valve is the opening of the electric proportional valve directly corresponding to the working switch gear, and the different switch gears of the thumb switch are directly set in relation with the flow of oil output by the electric proportional valve. Taking oil as oil, taking an example that a power source comprises an oil pump motor and an oil pump, fig. 2 is a corresponding relation between the opening of a thumb switch and a first flow of oil output by an electric proportional valve and a second flow or a third flow provided by the oil pump, a solid line is a corresponding relation between the output flow of the electric proportional valve and the opening of the thumb switch, and a dotted line is a corresponding relation between the output flow of the oil pump and the opening of the thumb switch; dividing the opening of the thumb switch into 5 points, wherein the opening setting of the thumb switch comprises 10%, 80%, 90%, 95% and 100%, and when the opening of the thumb switch is 0%, the first flow of the oil output by the corresponding electric proportional valve is 0min/L, namely the corresponding flow output when the electric proportional valve is at the minimum opening; when the opening of the thumb switch is 10%, the first flow of the oil output by the corresponding electric proportional valve is Q1min/L, and is in a small flow state at the moment, the output flow Q1' of the oil pump motor is larger than the first flow Q1 corresponding to the opening of the electric proportional valve, the oil flow corresponding to the opening of the electric proportional valve is calculated flow of the relative speed which is directly determined according to the opening of the thumb switch, and the output flow of the oil pump is calculated flow plus safety margin flow. The reason for setting the safety margin flow is that under the condition of a small flow state, the power of the small flow oil is limited, namely, the opening of the thumb switch is 0 to 90 percent, and because the pipeline and the electric proportional valve have partial loss, the output flow of the oil pump is required to be larger than the corresponding opening flow of the electric proportional valve, namely, the second flow is larger than the first flow, so that the better inching performance and the better speed regulation performance of the electric proportional valve are ensured; when the opening of the thumb switch is 80%, the first flow of the oil output by the corresponding electric proportional valve is Q2min/L, and is in a small flow state at the moment, and the output flow Q2' of the oil pump motor is still larger than the first flow Q2 corresponding to the opening of the electric proportional valve; under the condition of a large flow state, namely in the process that the opening of the wood switch is 90-100%, setting the opening corresponding flow of the electric proportional valve to be larger than the output flow of the oil pump, wherein the oil supplied by the oil pump to the electric proportional valve can be hopefully directly supplied to a working device through the electric proportional valve, so that the energy loss generated by the pressure loss of the electric proportional valve is reduced, and the opening of the thumb switch corresponds to the maximum flow which can be achieved by the electric proportional valve when the opening of the wood switch is 100%; therefore, when the opening of the thumb switch is 95%, the first flow rate of the oil output by the corresponding electric proportional valve is Q4min/L, and is in a large flow rate state at the moment, the output flow rate Q4 'of the oil pump motor is smaller than the first flow rate Q4 corresponding to the opening of the electric proportional valve, and when the opening of the thumb switch is 100%, the first flow rate of the oil output by the corresponding electric proportional valve is Q5min/L, and is in a large flow rate state at the moment, and the output flow rate Q5' of the oil pump motor is smaller than the first flow rate Q5 corresponding to the opening of the electric proportional valve. Meanwhile, in order to ensure the normal operation of the working device, the maximum flow of the electric proportional valve corresponding to the opening of the thumb switch when the opening is 100% is required to meet the theoretical requirement, and the function of the working device is ensured to reach the corresponding normal speed. Specifically, when the opening of the thumb switch is 90%, the corresponding first flow rate of the oil output by the electric proportional valve is Q3min/L, and the oil output by the oil pump motor is in an intermediate state of large flow rate and small flow rate, and at this time, the output flow rate Q3' of the oil pump motor is equal to the first flow rate Q3 corresponding to the opening of the electric proportional valve.

It is to be understood that there are various implementations of the correspondence between the setting of the operation gear of the operation device such as the thumb switch and the opening of the electric proportional valve, and the flow rate of the oil output by the electric proportional valve corresponding to the setting of the operation gear can satisfy the normal operation process of the working device, for example, the states that the opening of the thumb switch includes 10%, 20% and 100%, and the states that the opening of the thumb switch corresponds to 20%, 40% and 80% respectively, and the oil output flow rate corresponding to the electric proportional valve with the opening of 80% can satisfy the normal operation process of the working device can be set.

Specifically, referring to fig. 3, fig. 3 is a schematic structural diagram of a control device of a forklift working device according to the present invention; the main function of the control system of the forklift working device is to control the action parameters such as the speed of each action of the working device, so that the speed of the working device can realize the control of the action processes such as the speed of the working device by operating a thumb switch or other types of operation devices, for example, the larger the opening of the thumb switch is, the larger the flow of oil received by the driving device of the corresponding working device, namely the oil received by the oil cylinder is, and the faster the corresponding working device acts. Considering that the power source itself generally needs an independent controller, taking an oil liquid driven portal device as an example, a control system of the whole forklift working device comprises a control part and a hydraulic part, wherein the control part comprises a thumb switch or other types of operating devices, a controller and an oil pump motor controller, the hydraulic part comprises an oil pump motor, an oil pump, an electric proportional valve and a portal action oil cylinder, the controller receives a target action signal which is output by the thumb switch and is realized in an electric signal mode, determines a current signal for controlling the electric proportional valve and an indication signal for the oil pump motor controller based on the target action signal, controls the opening of the electric proportional valve to control the oil liquid flow which is output to the portal action oil cylinder through the current signal, and then controls the rotating speed of the oil pump motor by the oil pump motor controller, so that the oil pump outputs oil liquid with corresponding flow to the electric proportional valve.

As can be understood, referring to fig. 4, fig. 4 is a schematic diagram showing a correspondence relationship between a current signal received by an electric proportional valve and a position signal of a thumb switch according to the present invention; the controller is usually implemented by current signals for controlling the opening of the electric proportional valve, the opening of the electric proportional valve corresponds to the current signals one by one, so that the process of determining the target opening of the electric proportional valve corresponding to the target action signal, that is, generating the current signal for controlling the electric proportional valve according to the target action signal, according to fig. 2, the corresponding relation between the position signal of the thumb switch and the current signal for controlling the electric proportional valve as shown in fig. 4 can be further obtained, the abscissa of fig. 4 is the position signal of the thumb switch, the ordinate is the current signal output by the controller to the electric proportional valve, K1 or K2 is the maximum positions of the thumb switch in two different directions, the controller can directly determine the current signal output to the electric proportional valve based on fig. 4, imin is the minimum starting current of the electric proportional valve, I10 is the starting current of the electric proportional valve corresponding to 10% of the opening of the thumb switch, I80 is the starting current of the electric proportional valve corresponding to 80% of the opening of the thumb switch, I95% is the starting current of the electric proportional valve corresponding to 95% of the opening of the thumb switch, imax is the maximum position of the opening of the thumb switch, that is the electric proportional valve corresponding to 100%.

It is easy to understand that the matching relation between the oil flow output by the electric proportional valve and the oil flow output by the power source is controlled by the preset first corresponding relation between the oil flow output by the power source and the opening of the electric proportional valve, and the oil flow output by the electric proportional valve and the oil flow output by the power source with different matching relations are set under different flow conditions, so that the better inching performance and the better speed regulation performance of the electric proportional valve are ensured, the vibration and the noise are reduced, the energy loss of the system is reduced, and the energy conservation and the emission reduction are realized.

The invention provides a control method of a forklift working device, which comprises the steps of determining a target opening of an electric proportional valve, and determining a flow condition of output oil of a power source corresponding to the target opening by utilizing a first corresponding relation between the output oil flow of a preset power source and the opening of the electric proportional valve and the target opening; then controlling the electric proportional valve to output oil to the working device according to the target opening, and controlling the power source to output oil to the electric proportional valve according to the determined flow condition corresponding to the target opening; in the first corresponding relation, when the first flow corresponding to the target opening is smaller than a preset value, the second flow of the oil output by the power source is larger than the first flow, so that the oil flow of the input side of the electric proportional valve is larger than the oil flow of the output side, the electric proportional valve is prevented from working in a low flow state, and the conditions of unstable action, shaking and the like of the electric proportional valve caused by the low flow under the condition of small oil flow are avoided; when the first flow corresponding to the target opening is larger than a preset value, the third flow of the oil output by the power source is smaller than the first flow, so that the oil flow on the input side of the electric proportional valve is smaller than the oil flow on the output side, the speed of the electric proportional valve for conveying the oil to the working device is improved, and energy consumption is avoided; the matching relation between the flow of the electric proportional valve and the flow of the oil provided by the power source is ensured by the first corresponding relation between the flow of the oil output by the preset power source and the opening of the electric proportional valve, the inching performance and the speed regulation performance of the electric proportional valve are improved, the vibration and the noise are reduced, the accurate control of the electric proportional valve is realized, the energy loss of the whole system is reduced, and the energy and the emission are saved.

Based on the above embodiments:

as an alternative embodiment, the control method of the forklift working device further includes:

if the first flow is equal to the preset value, determining a fourth flow of the oil output by the power source based on a first corresponding relation between the preset oil output by the power source and the opening of the electric proportional valve and the target opening, wherein the fourth flow is equal to the first flow;

and controlling the power source to output oil to the electric proportional valve at the fourth flow rate, and controlling the electric proportional valve to output oil to the working device at the first flow rate.

It will be appreciated that there is an intermediate state between the high flow state and the low flow state where the first flow is equal to the preset value, and in this intermediate state, the fourth flow of the oil output by the power source may be equal to the first flow of the oil output by the electric proportional valve, and in this state, the power source or the electric proportional valve is not required to output a larger flow of the oil to improve the working performance of the electric proportional valve and the whole control process. In practical applications, the preset value may be set by determining a specific condition of the intermediate state of the electric proportional valve, and the intermediate state of the electric proportional valve may be determined by a plurality of tests or the like.

Specifically, in the intermediate state that the first flow is equal to the preset value, the fourth flow of the oil output by the power source is equal to the first flow of the oil output by the electric proportional valve, so that the working performance and the energy consumption of the electric proportional valve can be balanced, the control process of the electric proportional valve and the power source is further perfected, and the effective realization of the whole control process is facilitated.

Referring to fig. 5, fig. 5 is a schematic diagram showing a correspondence relationship between a position signal of a thumb switch and a voltage signal output by the thumb switch according to the present invention; as an alternative embodiment, the control system of the forklift working device further includes a thumb switch for receiving a target action signal of the working device and determining a target opening of the electric proportional valve corresponding to the target action signal, including:

And determining a position signal of the thumb switch, and determining a target opening of the electric proportional valve corresponding to the position signal based on the position signal of the thumb switch.

It is to be understood that, for convenience of user operation, the control of the working device may be achieved by providing an operating device of the type of a thumb switch in the control system of the forklift working device, at this time, the target action signal may be directly set to a voltage signal corresponding to a switch gear of the thumb switch, that is, an opening degree of the thumb switch, and a correspondence relationship between the opening degree of the thumb switch and the power source output flow rate, and the electric proportional valve output flow rate is set in advance, at this time, the controller may directly determine the target opening degree of the electric proportional valve and the first flow rate corresponding to the target opening degree based on a position signal of the thumb switch, that is, the opening degree of the thumb switch. The application is not particularly limited herein as to the specific type and implementation of the thumb switch, and may be implemented with other types of gear-adjustable operating devices.

Specifically, the thumb switch type operating device can be adopted to directly establish the connection between the operating processes of different gears and different openings and the output flow of the power source and the output flow of the electric proportional valve, so that a user can directly adjust the gears according to requirements to accurately control the action of the working device, and the control system of the whole forklift working device is facilitated to be simply and conveniently realized.

As an alternative embodiment, determining the position signal of the thumb switch comprises:

acquiring a voltage signal output by a thumb switch;

The position signal of the thumb switch is determined based on a second correspondence of the position of the thumb switch to the output voltage.

It is easy to understand that different opening degrees of the thumb switch can be output to the controller in a voltage signal mode, and the controller can determine the opening degree of the thumb switch, namely a position signal of the thumb switch according to the received voltage signal; the thumb switch can set the second corresponding relation between the position and the output voltage in advance, as shown in fig. 5, and the process of determining the position signal of the thumb switch by the controller can be a process of searching for the corresponding relation by directly using the second corresponding relation; taking the power source including the oil pump as an example, after determining the position signal of the thumb switch, the controller can determine the opening of the corresponding electric proportional valve and the rotational speed of the oil pump according to the corresponding relation between the opening of the thumb switch and the output flow, which is set in advance, wherein the corresponding relation between the opening of the thumb switch and the output flow includes the corresponding relation between the opening of the thumb switch and the output flow of the electric proportional valve, and the corresponding relation between the opening of the thumb switch and the output flow of the oil liquid of the power source, as shown in fig. 2.

Specifically, the second corresponding relation between the position set by the thumb switch and the output voltage is recorded in the controller in advance, and the controller can directly search and determine the position signal of the thumb switch based on the voltage signal output by the thumb switch and the second corresponding relation, so that the action requirement of a user is determined, and a target action signal is obtained, so that the opening of the electric proportional valve and the output oil flow of the power source meeting the requirement of the user can be accurately determined later.

As an alternative embodiment, the second thumb switch position-output voltage correspondence is provided with a voltage signal dead zone at the neutral position and the maximum position of the thumb switch.

In view of the fact that there may be inconsistency between the output voltages of different types of thumb switches or other types of operating devices, in order to facilitate the controller to accurately respond to the output voltages of different types of operating devices, the controller may perform dead zone processing on the voltage signals output by the thumb switches, as shown in fig. 5, where the abscissa of fig. 5 is the voltage signal output by the thumb switch, and the ordinate is the position signal of the thumb switch, when the output voltage corresponding to the full stroke of the thumb switch is in the voltage range of 0-5V, the neutral position of the thumb switch, that is, the output voltage in the middle position state is 2.5V, and in order to reduce the problem that errors between components cause malfunction in the system, the controller needs to perform dead zone setting on the thumb switch signals of 0-5V, that is, setting the electrical signal at the neutral position and the maximum position of the thumb switch no longer increases. The ordinate is the position signal of the thumb switch, K1 and K2 are the maximum positions of the thumb switch in two directions, 0 is the neutral position of the thumb switch, the processed voltage signal is in the voltage range of 0-5V, and 2.5V corresponds to the neutral position. The present application is not limited to the specific arrangement of the dead zone of the voltage signal, and the above embodiment is only one specific implementation.

It should be noted that, the positions of the thumb switch in two directions are for conveniently controlling different working processes of the working device, for the portal device, the positions of the thumb switch in two directions can respectively control two opposite working processes of ascending and descending of the portal, correspondingly, the electric proportional valve also has two output ports in two directions, and respectively respond to the position signals of the thumb switch in two directions, thereby further realizing the control of the ascending and descending working processes of the portal.

Specifically, in order to avoid the situation of misoperation after the controller receives the output voltage signals of the thumb switches, the controller can set corresponding voltage signal dead zones according to the second corresponding relation, and the misoperation of the working device caused by component errors when the controller faces different thumb switches is avoided through the dead zone setting mode, so that the accuracy and the reliability of the whole control process are improved.

Referring to fig. 6, fig. 6 is a schematic diagram showing a time-varying signal of a thumb switch according to the present invention; as an alternative embodiment, controlling an electro-proportional valve to output oil to a working device at a first flow rate includes:

determining the current opening of the electric proportional valve and the current flow corresponding to the current opening;

And controlling the opening degree of the electric proportional valve to be uniformly changed from the current opening degree to the target opening degree according to the first preset speed, so that the output oil flow output to the working device by the electric proportional valve is uniformly changed from the current flow to the first flow.

It is to be understood that in the process of adjusting the output oil flow rate by the electric proportional valve and the power source based on the control of the controller, in order to avoid the impact on the electric proportional valve, the power source and components in the whole system caused by the instantaneous change of the flow rate, in the process of adjusting the output oil of the electric proportional valve and the power source by the controller, the controller performs slope filtering processing on a target action signal received from the thumb switch, and in the process of receiving the position signal of the thumb switch, namely, the target action signal and in the process of determining the output oil flow rate of the electric proportional valve and the power source based on the target action signal, a certain delay is set to enable the output oil flow rate of the electric proportional valve to gradually change to a first flow rate corresponding to the target action signal, and the output oil flow rate of the power source also gradually changes to a second flow rate or a third flow rate; in particular, this gradual change process may be a process that uniformly changes at a preset speed.

Specifically, as shown in fig. 6, the abscissa of fig. 6 is time, the ordinate is the position signal of the thumb switch, when the target action signal received by the controller from the thumb switch, that is, the position signal is K1, the controller sets the rising delay time INC 1 when the position signal of the thumb switch reaches a preset maximum value of K1 from the minimum, the opening of the electric proportional valve is gradually changed from the minimum opening corresponding to the neutral position of the thumb switch to the maximum opening corresponding to the maximum position of the thumb switch based on the rising delay time INC 1, and the output oil flow of the corresponding power source is also gradually increased from zero to the second flow or the third flow corresponding to the maximum opening of the electric proportional valve; when the position signal of the thumb switch is changed from the preset maximum value of K1 to the minimum value, the falling delay time DEC T1 is set, the opening of the electric proportional valve is gradually changed from the maximum opening corresponding to the maximum position K1 of the thumb switch to the minimum opening corresponding to the neutral position based on the falling delay time DEC T1, and the output oil flow of the corresponding power source is gradually reduced to zero from the second flow or the third flow corresponding to the maximum opening of the electric proportional valve. For the setting mode of the position signal K2 in the other direction is the same as the setting mode of the position signal K1, the rising delay time INC T2 and the falling delay time DEC T2 corresponding to the position signal K2 are set, and the invention is not described herein.

Specifically, the main purpose of setting up delay time and down delay time, namely setting certain delay time is to avoid impact caused by instantaneous change of flow, and the change process of the output oil flow of the electric proportional valve and the power source is gradually changed by setting delay or setting the change speed of the opening of the electric proportional valve, so that the stability of working processes such as starting and stopping of the action of the working device is ensured, hydraulic impact is reduced, and the safety and reliability of the whole system are further improved.

As an alternative embodiment, the control method of the forklift working device further includes:

determining the current opening of the electric proportional valve and the current flow corresponding to the current opening;

When the target action signal of the working device is stopping action, the opening of the electric proportional valve is controlled to be uniformly changed to zero from the current opening according to a second preset speed.

It should be understood that, when the target operation signal of the working device is the stop operation, in order to ensure the stability of the stop operation process of the working device, the process of reducing the output oil flow rate of the electric proportional valve and the power source controlled by the controller needs to be a gradual change process, and at this time, the opening degree of the electric proportional valve needs to be gradually changed to the minimum opening degree, and the minimum opening degree is usually zero.

Specifically, in order to avoid impact caused by instantaneous change of flow, the change process of the output oil flow of the electric proportional valve and the power source is gradually changed by setting delay or setting the change speed of the opening of the electric proportional valve, so that the stability of working processes such as stopping of a working device is ensured, hydraulic impact is reduced, and the safety and reliability of the whole system are further improved.

As a specific embodiment, referring to fig. 7, fig. 7 is a schematic flow chart of a control method of another forklift working device according to the present invention, based on the control device of the forklift working device shown in fig. 3; the method comprises the steps that a user operates a thumb switch to output a target action signal of a required working device to a controller, after the controller receives an electric signal output by the thumb switch, the electric signal is sent to an oil pump motor controller, so that the oil pump motor controls to determine a second flow or a third flow corresponding to a first flow of an electric proportional valve according to the electric signal output by the thumb switch and a first corresponding relation between a preset power source output oil flow and an electric proportional valve opening, and starts a corresponding oil pump motor rotating speed instruction to control the oil pump motor based on the second flow or the third flow, and the oil pump motor controls the oil pump to output the corresponding second flow or the oil of the third flow to the electric proportional valve according to the rotating speed instruction; and the controller outputs a current value of the control electric proportional valve corresponding to the target opening according to the corresponding relation between the current signal received by the electric proportional valve and the position signal of the thumb switch after slope filtering processing is carried out on the electric signal received by the thumb switch, and the current value acts on the electric proportional valve to enable a valve core of the electric proportional valve to generate displacement corresponding to the target opening, so that oil liquid with a first flow rate is output to a portal acting oil cylinder by utilizing oil liquid received from an oil pump, and a working device generates corresponding action or an action process reaching a preset speed.

Referring to fig. 8, fig. 8 is a schematic structural diagram of a control device of another forklift working device according to the present invention; in order to solve the technical problem, the invention also provides a control device of the forklift working device, which is applied to a controller in a control system of the forklift working device, and the control device of the forklift working device comprises:

A target opening determining unit 11 for receiving a target operation signal of the working device and determining a target opening of the electric proportional valve corresponding to the target operation signal;

a first flow rate determining unit 12, configured to determine a first flow rate corresponding to the target opening, and determine whether the first flow rate is greater than a preset value; if not, triggering a second flow determining unit, and if so, triggering a third flow determining unit;

A second flow determining unit 13, configured to determine a second flow of the oil output by the power source based on a first corresponding relationship between the preset flow of the oil output by the power source and the opening of the electric proportional valve and the target opening; the second flow is greater than the first flow;

A third flow rate determining unit 14, configured to determine a third flow rate of the oil output by the power source based on a first corresponding relationship between the preset oil output by the power source and the opening of the electro proportional valve and the target opening; the third flow rate is smaller than the first flow rate;

and the control unit 15 is used for controlling the power source to output oil to the electric proportional valve at the second flow rate or the third flow rate and controlling the electric proportional valve to output oil to the working device at the first flow rate.

For the description of the control device of the forklift working device provided by the present invention, reference is made to the embodiment of the control method of the forklift working device, and the description of the present invention is omitted herein.

Referring to fig. 9, fig. 9 is a schematic structural diagram of a control system of a forklift working device according to the present invention. In order to solve the technical problem, the invention also provides a control system of the forklift working device, which comprises:

a memory 21 for storing a computer program;

a controller 22 for implementing the steps of the control method of the fork truck working apparatus as described above.

Among other things, the controller 22 may include one or more processing cores, such as a 4-core processor, an 8-core processor, and the like. The controller 22 may be implemented in at least one hardware form of DSP (DIGITAL SIGNAL Processor), FPGA (Field-Programmable gate array), PLA (Programmable Logic Array ). The controller 22 may also include a main processor, which is a processor for processing data in an awake state, also called a central processor, and a coprocessor; a coprocessor is a low-power processor for processing data in a standby state. In some embodiments, the controller 22 may integrate a GPU (graphics processing unit, graphics processor) for rendering and drawing of content that is required to be displayed by the display screen. In some embodiments, the controller 22 may also include an AI (ARTIFICIAL INTELLIGENCE ) processor for processing computing operations related to machine learning.

Memory 21 may include one or more computer-readable storage media, which may be non-transitory. Memory 21 may also include high-speed random access memory, as well as non-volatile memory, such as one or more magnetic disk storage devices, flash memory storage devices. In this embodiment, the memory 21 is at least used for storing a computer program, where the computer program is loaded and executed by the controller 22 to implement the relevant steps of the control method of the forklift working device disclosed in any one of the foregoing embodiments. In addition, the resources stored in the memory 21 may also include an operating system, data, and the like, and the storage manner may be transient storage or permanent storage. The operating system may include Windows, unix, linux, among other things. The data may include, but is not limited to, data of a control method of the forklift work device, and the like.

In some embodiments, the control system of the forklift working device can further comprise a display screen, an input-output interface, a communication interface, a power supply and a communication bus.

It will be appreciated by those skilled in the art that the configuration shown in fig. 9 is not limiting of the control system of the truck working device and may include more or fewer components than shown.

For the description of the control system of the forklift working device provided by the present invention, please refer to an embodiment of the control method of the forklift working device, and the description of the present invention is omitted herein.

In order to solve the above technical problem, the present invention further provides a computer readable storage medium, on which a computer program is stored, which when executed by a processor implements the steps of the control method of the forklift working device as described above.

It will be appreciated that the methods of the above embodiments, if implemented in the form of software functional units and sold or used as stand-alone products, may be stored on a computer readable storage medium. Based on this understanding, the technical solution of the present application may be embodied essentially or in part or all of the technical solution or in part in the form of a software product stored in a storage medium for performing all or part of the steps of the method according to the embodiments of the present application. In particular, the computer readable storage medium may include, but is not limited to, any type of disk including floppy disks, optical disks, and removable hard disks, etc., or any type of medium or device suitable for storing instructions, data, etc., the application is not limited in particular herein.

For an introduction of a computer readable storage medium provided by the present invention, please refer to an embodiment of a control method of the forklift working device, and the disclosure is not repeated herein.

In the present specification, each embodiment is described in a progressive manner, and each embodiment is mainly described in a different point from other embodiments, and identical and similar parts between the embodiments are all enough to refer to each other. For the device disclosed in the embodiment, since it corresponds to the method disclosed in the embodiment, the description is relatively simple, and the relevant points refer to the description of the method section.

It should also be noted that in this specification, relational terms such as first and second, and the like are used solely to distinguish one entity or action from another entity or action without necessarily requiring or implying any actual such relationship or order between such entities or actions. Moreover, the terms "comprises," "comprising," or any other variation thereof, are intended to cover a non-exclusive inclusion, such that a process, method, article, or apparatus that comprises a list of elements does not include only those elements but may include other elements not expressly listed or inherent to such process, method, article, or apparatus. Without further limitation, an element defined by the phrase "comprising one … …" does not exclude the presence of other like elements in a process, method, article, or apparatus that comprises the element.

Those of skill would further appreciate that the various illustrative elements and algorithm steps described in connection with the embodiments disclosed herein may be implemented as electronic hardware, computer software, or combinations of both, and that the various illustrative elements and steps are described above generally in terms of functionality in order to clearly illustrate the interchangeability of hardware and software. Whether such functionality is implemented as hardware or software depends upon the particular application and design constraints imposed on the solution. Skilled artisans may implement the described functionality in varying ways for each particular application, but such implementation decisions should not be interpreted as causing a departure from the scope of the present invention.

The previous description of the disclosed embodiments is provided to enable any person skilled in the art to make or use the present invention. Various modifications to these embodiments will be readily apparent to those skilled in the art, and the generic principles defined herein may be applied to other embodiments without departing from the spirit or scope of the invention. Thus, the present invention is not intended to be limited to the embodiments shown herein but is to be accorded the widest scope consistent with the principles and novel features disclosed herein.

Claims (8)

1. The control method of the forklift working device is characterized by being applied to a controller in a control system of the forklift working device, and comprises the following steps of:

Receiving a target action signal of the working device, and determining a target opening of the electric proportional valve corresponding to the target action signal;

Determining a first flow corresponding to the target opening degree, and judging whether the first flow is larger than a preset value or not;

if not, determining a second flow of the oil output by the power source based on a first corresponding relation between the preset oil output by the power source and the opening of the electric proportional valve and the target opening; the second flow rate is greater than the first flow rate;

If yes, determining a third flow of the oil output by the power source based on a first corresponding relation between the preset oil output by the power source and the opening of the electric proportional valve and the target opening; the third flow rate is less than the first flow rate;

and controlling the power source to output oil to the electric proportional valve at the second flow rate or the third flow rate, and controlling the electric proportional valve to output oil to the working device at the first flow rate.

2. The method of controlling a forklift working device according to claim 1, further comprising:

if the first flow is equal to the preset value, determining a fourth flow of the oil output by the power source based on a first corresponding relation between the preset oil output by the power source and the opening of the electric proportional valve and the target opening, wherein the fourth flow is equal to the first flow;

and controlling the power source to output oil to the electric proportional valve at the fourth flow rate, and controlling the electric proportional valve to output oil to the working device at the first flow rate.

3. The method of controlling a forklift working device according to claim 1, wherein the control system of the forklift working device further includes a thumb switch, the receiving a target action signal of the working device and determining a target opening of the electric proportional valve corresponding to the target action signal includes:

and determining a position signal of the thumb switch, and determining a target opening of the electric proportional valve corresponding to the position signal based on the position signal of the thumb switch.

4. A method of controlling a forklift working device according to claim 3, wherein said determining the position signal of the thumb switch comprises:

Acquiring a voltage signal output by the thumb switch;

A position signal of the thumb switch is determined based on a second correspondence of a position of the thumb switch to an output voltage.

5. The method of claim 4, wherein the second thumb switch position-output voltage correspondence is provided with a voltage signal dead zone at a neutral position and a maximum position of the thumb switch.

6. A method of controlling a forklift working device as claimed in any one of claims 1 to 5, wherein said controlling said electro-proportional valve to output oil to said working device at said first flow rate comprises:

Determining the current opening of the electric proportional valve and the current flow corresponding to the current opening;

And controlling the opening degree of the electric proportional valve to uniformly change from the current opening degree to the target opening degree according to a first preset speed, so that the output oil flow output by the electric proportional valve to the working device uniformly changes from the current flow to the first flow.

7. The method of controlling a forklift working device according to claim 6, further comprising:

Determining the current opening of the electric proportional valve and the current flow corresponding to the current opening;

and when the target action signal of the working device is stopping action, controlling the opening degree of the electric proportional valve to uniformly change from the current opening degree to zero according to a second preset speed.

8. A control system for a forklift working device, comprising:

A memory for storing a computer program;

A controller for implementing the steps of the method of controlling a forklift working device according to any one of claims 1 to 7.