CN218261825U

CN218261825U - Safety control system of forklift

Info

Publication number: CN218261825U
Application number: CN202221865728.7U
Authority: CN
Inventors: 傅敏; 夏庆超; 娄鑫涛
Original assignee: Ningbo Ruyi JSCL
Current assignee: Ningbo Ruyi JSCL
Priority date: 2022-07-19
Filing date: 2022-07-19
Publication date: 2023-01-10
Anticipated expiration: 2032-07-19

Abstract

The utility model relates to a fork truck's safety control system, its characterized in that: the weighing device comprises a weighing module, a weighing module and a control module, wherein the weighing module is used for weighing the weight of goods to be lifted of the forklift; the height encoder is used for measuring the lifting height of the forklift; and a controller connected with the weighing module and the height encoder and configured to: the controller stores a function formula between the weight of the goods and the lifting height, calculates the lifting height allowed by a weighing result of the weighing module according to the function formula, and compares the lifting height with the lifting height measured by the height encoder so as to send a signal for indicating whether the forklift stops lifting. The utility model has the advantages that: the system can automatically realize the control of lifting through the controller, has simple realization mode, does not need artificial judgment, improves the accuracy rate of load condition judgment, and can ensure the safety of forklift operators.

Description

Safety control system of forklift

Technical Field

The utility model relates to an industrial vehicle technical field, in particular to fork truck's safety control system.

Background

According to the relevant standard requirements of industrial vehicles, clear and permanent labels are arranged at obvious positions of the forklift, at least the actual lifting capacity at the maximum lifting height and the actual lifting capacity at other lifting heights are marked on the labels, and manufacturers generally give the actual lifting capacity in the form of a load curve.

The load curve is a relation graph of the lifting capacity and the lifting height of the forklift, the load curves of different manufacturers and different vehicle types are different, when the forklift works, an operator needs to operate and control according to the relation graph corresponding to the lifting capacity and the lifting height given by the forklift manufacturer, namely, the weight of lifted goods cannot exceed the allowable height corresponding to the graph, otherwise, the forklift can tip over due to use exceeding the design capacity, property loss is caused to light persons, and casualties are caused to heavy persons.

Although a manufacturer provides a forklift load curve according to standard regulations, in actual use, a forklift operator often does not know the weight of currently operated goods and the accurate height of the current forklift during lifting, so that in order to prevent the forklift from tipping, on one hand, the operator needs to know the load capacity of the forklift, and on the other hand, the operator needs to accurately judge the load condition through experience and perform safety control, which obviously makes the forklift operator difficult. Further improvements are needed for this purpose.

SUMMERY OF THE UTILITY MODEL

The utility model aims to solve the technical problem that a can guarantee safe fork truck's safety control system is provided to above-mentioned prior art.

The utility model provides a technical scheme that above-mentioned technical problem adopted does: a safety control system of a forklift is characterized in that: comprises that

The weighing module is used for weighing the weight of the goods to be lifted of the forklift;

the height encoder is used for measuring the lifting height of the forklift; and

a controller coupled to the weighing module and the height encoder and configured to: the controller is stored with a function formula between the weight of the goods and the lifting height, calculates the result weighed by the weighing module according to the function formula, allows the lifting height, and compares the result with the lifting height measured by the height encoder, so as to send a signal whether the forklift stops lifting.

In order to realize the ascending and descending detection of the forklift and simultaneously detect the height, preferably, the height encoder is an incremental encoder which is driven to rotate by a lifting mechanism of the forklift.

In this scheme, the weighing module includes weighing sensor and the MCU that is connected with weighing sensor.

In order to make the weighing result more accurate, preferably, the weighing module further comprises an amplifying and filtering circuit and an a/D conversion circuit, wherein one end of the amplifying and filtering circuit is connected with the output end of the weighing sensor and is used for amplifying and filtering the electric signal output by the weighing sensor; the other end of the amplifying and filtering circuit is connected with one end of the A/D conversion circuit, and the other end of the A/D conversion circuit is connected with the MCU and used for converting analog signals collected by the weighing sensor into digital signals.

In order to realize the safety control of the forklift, a communication module is further arranged between the controller and a lifting controller of the forklift.

Further, the communication module comprises a CAN bus and a canopy protocol stack, wherein the CAN bus is connected with a lifting controller of the forklift, and the canopy protocol stack is used for realizing communication between the controller and the lifting controller of the forklift.

Further, the controller also comprises a power supply module used for supplying power for the controller.

Compared with the prior art, the utility model has the advantages of: through the function formula between the weight of the goods and the lifting height stored in the controller, the controller calculates the result weighed by the weighing module according to the function formula, the lifting height can be allowed, and the result is compared with the lifting height measured by the height encoder, so that a signal indicating whether the forklift stops lifting is sent. Therefore, the system can automatically realize the control of lifting through the controller, has simple realization mode, does not need artificial judgment, improves the accuracy rate of load condition judgment, and can ensure the safety of forklift operators.

Drawings

Fig. 1 is a schematic block diagram of a safety control system of a forklift in an embodiment of the present invention;

fig. 2 is a waveform diagram of the output of the incremental encoder of fig. 1.

Detailed Description

The present invention will be described in further detail with reference to the following embodiments.

As shown in fig. 1, the forklift includes a lift controller, a lift switch K1, a lowering switch K2, and a lift generator. The safety control system of the forklift in this embodiment includes a weighing module, a height encoder, and a controller (i.e., CPU in fig. 1). The weighing module is used for weighing the weight of goods to be lifted of the forklift and can be arranged on fork teeth of the forklift; the height encoder is used for measuring the lifting height of the forklift; the controller is coupled to the weighing module and the height encoder and configured to: the controller stores a function formula between the weight of the goods and the lifting height, calculates the result weighed by the weighing module according to the function formula, allows the lifting height, compares the result with the lifting height measured by the height encoder, and sends a signal whether the forklift stops lifting action or not, and the lifting controller controls the lifting generator to stop after receiving the signal for stopping lifting action.

The height encoder can be an absolute encoder, certainly, the rising of fork truck in this embodiment includes two processes of rising and descending, in order to realize when measuring the rising height, also can judge that fork truck is currently in and rises, still descends, and the height encoder is incremental encoder in this embodiment (prior art can be referred to this incremental encoder's concrete principle, does not expand here and describe), and incremental encoder is rotatory by the hoisting mechanism drive of fork truck.

The lifting mechanism on the forklift is driven to rotate, two pulse signals A, B are output during rotation, the phase difference of A, B output signals is 90 degrees, and the output signals have vectority as shown in figure 2. The rotation direction of the incremental encoder is identified through the phase difference, namely the current forklift is in an ascending state or a descending state, so that the addition and subtraction operation can be performed on the height change.

The output pattern of the incremental encoder is: number of millimeters per pulse (mm/P). The height is calculated from the number of pulses output by the encoder.

The software design requires the following definition for the output phase of the encoder A, B:

if the A signal leads the B signal by 90 degrees (as shown in the waveform on the left side of the figure 2) when the forklift rises, the addition operation is adopted; on the other hand, when the forklift descends, the phase of the B signal is 90 degrees ahead of that of the A signal (as shown in the waveform on the right side of the figure 2), and subtraction is performed.

For example: the output of the selected incremental encoder is 0.15mm/p, namely, the measurement height of the incremental encoder is 0.15mm when the incremental encoder outputs 1 pulse, if the incremental encoder outputs 2000 pulses and the phase of an output signal A is 90 degrees ahead of the phase of B, the forklift is in a rising state by definition, and the controller software calculates the lifting height of the forklift to be 300mm according to the input number of the pulses and accumulates the lifting height on the original height; on the contrary, if the output signal B leads the phase A by 90 degrees, the forklift is in a descending state by definition, the controller software calculates the descending height of the forklift to be 300mm according to the pulse input number, and subtracts the original height to calculate the actual height of the current forklift.

In the embodiment, the weighing module comprises a weighing sensor, an amplifying and filtering circuit, an A/D conversion circuit and an MCU which are sequentially connected, wherein the amplifying and filtering circuit is used for amplifying and filtering an electric signal output by the weighing sensor so as to meet the requirement of the A/D converter on the level of an input signal, and filtering and eliminating interference force which is generated by other factors and acts on the weighing sensor when the forklift is dynamically weighed, so that the measurement precision is improved; the A/D conversion circuit is used for converting the analog signals collected by the weighing sensor into digital signals.

And a communication module is also arranged between the controller and a lifting controller of the forklift. In this embodiment, the communication module includes a CAN bus that connects the controller and the lift controller of the forklift, and a canopy protocol stack that realizes communication between the controller and the lift controller of the forklift.

The DC-DC converter is responsible for voltage reduction and voltage stabilization of an external power supply and provides stable working voltage for the controller.

The working principle of the safety control system of the forklift in the embodiment is as follows: the forklift lifting switch is closed, the lifting motor operates, the forklift lifts, the weight of goods is obtained through the weighing module, the controller calculates the allowable lifting height of the weighing result of the weighing module according to a function formula between the weight of the goods and the lifting height, the allowable lifting height is compared with the lifting height measured by the height encoder, when the actual lifting height is larger than the calculated allowable lifting height, the controller sends message data to the lifting controller through the CAN bus, the lifting controller stops the driving output of the lifting motor, the forklift lifts in a limited mode, and automatic control of the load according to the load curve requirement is achieved.

The automatic control device for the forklift load can be widely applied only by rewriting a curve function formula according to the load curve requirements of different vehicle types, and has good integration.

The foregoing is only a preferred embodiment of the present invention, and it should be noted that, for those skilled in the art, a plurality of improvements and decorations can be made without departing from the technical principle of the present invention, and these improvements and decorations should also be regarded as the protection scope of the present invention.

Claims

1. The utility model provides a fork truck's safety control system which characterized in that: comprises that

a controller connected with the weighing module and the height encoder and configured to: the controller stores a function formula between the weight of the goods and the lifting height, calculates the lifting height allowed by the weighing result of the weighing module according to the function formula, and compares the lifting height with the lifting height measured by the height encoder so as to control whether the forklift stops lifting.

2. The safety control system for a forklift according to claim 1, characterized in that: the height encoder is an incremental encoder, and the incremental encoder is driven to rotate by a lifting mechanism of a forklift.

3. The safety control system for a forklift according to claim 1, characterized in that: the weighing module comprises a weighing sensor and an MCU connected with the weighing sensor.

4. The safety control system for a forklift according to claim 3, characterized in that: the weighing module further comprises an amplifying and filtering circuit and an A/D conversion circuit, wherein one end of the amplifying and filtering circuit is connected with the output end of the weighing sensor and is used for amplifying and filtering the electric signal output by the weighing sensor; the other end of the amplifying and filtering circuit is connected with one end of the A/D conversion circuit, and the other end of the A/D conversion circuit is connected with the MCU and used for converting analog signals collected by the weighing sensor into digital signals.

5. The safety control system for a forklift according to claim 1, characterized in that: and a communication module is also arranged between the controller and a lifting controller of the forklift.

6. The safety control system for a forklift according to claim 5, characterized in that: the communication module comprises a CAN bus and a canopy protocol stack, wherein the CAN bus is connected with a lifting controller of the forklift, and the canopy protocol stack is used for realizing communication between the controller and the lifting controller of the forklift.

7. The safety control system for a forklift according to any one of claims 1 to 6, wherein: the controller also comprises a power supply module used for supplying power to the controller.