KR20250037846A - Apparatus for prevening thh overturn of crane - Google Patents

Abstract

The present invention relates to a crane overturn prevention device, and more specifically, to a device for lifting a salvageable object and having a crane mounted on a movable body, the device comprising: a plurality of outriggers supporting the movable body and each including a hydraulic cylinder therein; a pressure sensor unit provided on one side of the hydraulic cylinder and detecting pressure generated from the hydraulic cylinder; a horizontal angle sensor unit mounted on the outrigger unit and measuring a horizontal inclination with respect to the outrigger unit; and a control unit receiving a measurement value of the horizontal angle sensor unit and controlling the operation of the hydraulic cylinder and the crane according to the received measurement value when an overturning moment that overturns the crane is activated by lifting the salvageable object.

Description

{APPARATUS FOR PREVENING THH OVERTURN OF CRANE}

The present invention relates to a crane overturn prevention device, and more specifically, to a crane overturn prevention device that reduces the maximum speed of a crane's operation based on the pressure of a pressure sensor and restricts the operation of the crane when the angle based on a horizontal sensor is greater than a preset angle.

In general, the function of a crane is to lift objects and move and transport heavy objects.

The boom installed on the crane vehicle is capable of horizontal and vertical rotation, so after hanging the salvage object on a lifting device such as a boom hook, the salvage object can be transported to a desired location by rotating the boom system horizontally or by raising and lowering it.

In this way, lifting a heavy load on the crane boom and operating the boom generates a moment in the crane vehicle, which may cause the truck mounted crane to overturn.

Therefore, in order to prevent the crane from overturning as described above, crane vehicles are generally equipped with outriggers, and outriggers are used on the sides of crane vehicles, which are particularly dangerous.

The overturn prevention devices installed in existing cranes were configured to sense the amount of outrigger extension using a stroke sensor.

Therefore, a large number of proximity sensors, stroke sensors, swing angle sensors, and load sensors are required to prevent overturning, and the system contains too many sensors, which increases the complexity of operation and costs a lot of money to build.

In addition, since the overturn prevention of existing cranes is controlled by mapping the load based on the outrigger spread amount and sensor information of the crane's control unit, the operation is not flexible and is controlled only by the on/off operation of the solenoid valve, so there is a problem that rapid changes occur and a strong impact is applied to the crane.

Korean Utility Model Publication No. 20-1998-038634 (published on September 15, 1998)

The present invention aims to prevent the overturning of a crane by improving the existing crane overturn prevention by reducing the maximum working speed of the crane based on the pressure of the pressure sensor of the outrigger and restricting the operation of the crane when the horizontal sensor reference angle is greater than a preset angle, thereby preventing impact from being applied to the crane without requiring many sensors.

The present invention relates to a device for lifting an object and having a crane mounted on a mobile body, the device comprising: a plurality of outriggers supporting the mobile body and each including a hydraulic cylinder therein; a pressure sensor unit provided on one side of the hydraulic cylinder and detecting pressure generated from the hydraulic cylinder; a horizontal angle sensor unit mounted on the outriggers and measuring a horizontal inclination with respect to the outriggers; and a control unit receiving a measurement value of the horizontal angle sensor unit and controlling the operation of the hydraulic cylinder and the crane according to the received measurement value when the object is lifted and an overturning moment that overturns the crane is activated.

Whether or not the above overturning moment has occurred can be determined by determining whether or not the horizontal angle sensor section exceeds a preset threshold angle.

Whether or not the above overturning moment has occurred can be determined by determining whether the pressure of the pressure sensor section is below a preset threshold pressure.

The operation of the above control unit may limit the operation of one or more of the winch drum, derrick cylinder, and telescopic unit mounted on the crane.

The operation of the above control unit can limit the operation of the crane even according to the operation input of the crane by using proportional control.

The present invention improves the existing crane overturn prevention by reducing the maximum working speed of the crane based on the pressure of the pressure sensor of the outrigger and restricting the operation of the crane when the horizontal sensor reference angle is greater than a preset angle, so that the overturn of the crane can be prevented by preventing impact to the crane without requiring many sensors for overturn prevention.

FIG. 1 is a configuration diagram illustrating a crane overturn prevention device according to one embodiment of the present invention.
Figure 2 is an electro-hydraulic MCV circuit diagram according to one embodiment of the present invention.
Figure 3 is a circuit diagram of an electro-hydraulic outrigger unit according to one embodiment of the present invention.

Hereinafter, embodiments disclosed in this specification will be described in detail with reference to the attached drawings. Regardless of the reference numerals used in the drawings, identical or similar components will be given the same reference numerals and redundant descriptions thereof will be omitted. In addition, when describing embodiments disclosed in this specification, if it is determined that a detailed description of a related known technology may obscure the gist of the embodiments disclosed in this specification, the detailed description thereof will be omitted.

Terms that include ordinal numbers, such as first, second, etc., may be used to describe various components, but the components are not limited by the terms. The terms are used only to distinguish one component from another.

Singular expressions include plural expressions unless the context clearly indicates otherwise.

In this application, each step described may be performed regardless of the listed order, except in cases where it must be performed in the listed order due to a special causal relationship.

In this application, it should be understood that terms such as “comprises” or “has” are intended to specify the presence of a feature, number, step, operation, component, part or combination thereof described in the specification, but do not exclude in advance the possibility of the presence or addition of one or more other features, numbers, steps, operations, components, parts or combinations thereof.

Hereinafter, the present invention will be described with reference to the attached drawings.

Figure 1 is a configuration diagram showing a crane overturn prevention device according to one embodiment of the present invention, Figure 2 is a circuit diagram of an electro-hydraulic MCV (Main Control Valve) according to one embodiment of the present invention, and Figure 3 is a circuit diagram of an electro-hydraulic outrigger part according to one embodiment of the present invention.

In one embodiment of the present invention, the prevention of overturning of a crane may be applied to a main or sub electronic controller as an MCU (Main Controller Unit).

Here, the maximum speed of the crane equipment can be reduced based on the pressure of the MCU and pressure sensor, and the operation of the crane equipment can be prohibited when the horizontal sensor is at a reference angle or higher.

In one embodiment of the present invention, a proportional valve is operated in a FEH (Full Electronic Hydraulic control system) type MCV to increase or decrease the maximum speed of the crane equipment, and the operation of the crane equipment is controlled even when a joystick is input. A variable horsepower control pump is applied to the FEH.

For reference, the FEH system allows electronic proportional control with a fingertip lever.

In this way, compared to existing equipment that uses both hands with manual levers for long periods of time, which increases fatigue and reduces work efficiency, user convenience is increased, and since electronic fingertip levers are used, work convenience and fatigue are reduced.

The FEH system automatically controls the flow rate in complex operations using electronic proportional control.

In other words, the controller automatically calculates the flow rate required for the task and controls it according to the task mode, thereby reducing worker fatigue and enabling the implementation of a comfortable system for the worker.

Depending on the work mode, flow control variables can be tuned, and a smart system can be built that can be customized according to the operator's tendencies.

In terms of operation, you can set Auto mode and Manual mode, and if you select Auto mode in the combined operation of the telescopic part and winch drum, the winch drum will operate together.

And regardless of the auto or manual mode, the flow rate control ratio can be automatically selected and controlled using an electronic proportional control valve.

First, referring to FIG. 1, in one embodiment of the present invention, a crane is configured as a straight-line type truck mounted crane and has the function of lifting an object.

The crane includes a boom system installed on the body to lift the load and an outrigger part (100) to support the crane from the ground.

For reference, in the case of a special vehicle using an outrigger (100), there is a change in the pressure of the outrigger (100) when there is no unfolding amount and when it is unfolded to the maximum. Therefore, the moment increases depending on the unfolding amount, requiring more force, and the pressure increases to create that force.

It includes a lifting device that lifts a load by being able to be lifted, including a base (21) installed on a body of a crane vehicle, a post (22) installed on the base so as to be rotatable in a horizontal direction, a boom (20) installed on the post (22) so as to be rotatable in a vertical direction, a telescopic part (900) provided so as to be able to adjust the length of the boom (20), and a wire (28) supported on an end of the telescopic part (900).

The base (21) functions to connect the body of the crane vehicle and the boom (22). Therefore, by fixing the base (21) to the body of the crane vehicle, the boom (20) can be easily installed on the crane.

The post (22) is installed so as to be rotatable horizontally on the base (21) and acts as a kind of pillar connecting the base (21) and the boom (20).

Accordingly, as the post (22) rotates horizontally, the boom (20) can be rotated horizontally, thereby enabling various movements of the boom (20) and making it easy to lift. In this case, the horizontal rotation of the post (22) can be achieved by a hydraulic motor or the like.

The boom (20) is hinge-connected to the post by a hinge axis, and can be rotated vertically as the derrick piston (27) of the derrick cylinder (26) is withdrawn and retracted.

In addition, the boom (20) may be equipped with a telescopic part (900), and additional auxiliary sub-booms may be installed on the telescopic part (900), and the length of the boom (20) may be adjusted as each part is extended and retracted.

One end of the wire (28) is connected to a winch drum (not shown), and the other end is connected to a lifting device. Accordingly, the wire (28) can be wound or unwound according to the rotation of the winch drum (not shown), and through this, the lifting device can be raised and lowered.

The lifting device is raised and lowered through a wire by the winding or unwinding action of a winch drum (not shown), and may be configured with a hook or the like to facilitate the lifting of the object to be lifted.

A boom (20) having the above configuration can move a salvage object to a desired location by hanging it on a salvage device and lifting it. In addition, it can be moved by being installed on a crane.

First, in the present invention, the crane overturn prevention device (10) is a device that lifts a load and is mounted on a mobile body with a crane, and includes an outrigger unit (100), a pressure sensor unit (300), a horizontal angle sensor unit (500), and a control unit (700).

The outrigger part (100) is composed of a plurality of parts that support the crane body and each have a hydraulic cylinder (110) inside. A support part connected by a hinge part may be located at one end of the outrigger part (100), and a plate (not shown) may be additionally connected.

That is, the outrigger part (100) may be located, for example, on the front left, front right, rear left, rear right, etc. of the crane, and it is obvious that such arrangement does not limit the scope of the present invention.

Next, a pressure sensor unit (300) is provided on one side of the hydraulic cylinder (110) and detects the pressure generated in the hydraulic cylinder (110).

This pressure sensor unit (300) can detect the pressure generated from the hydraulic cylinder (110) and transmit the detected pressure information to the control unit (700) in the form of a current or voltage in a predetermined mA or mV unit, thereby enabling control so as not to be affected by external noise.

The hydraulic cylinder (110) can be extended and contracted toward or against the ground by hydraulic pressure, and a pressure sensor unit (300) is provided on one side of the hydraulic cylinder (110) to detect the pressure inside the hydraulic cylinder (110).

The pressure sensor unit (300) can sense the pressure of the hydraulic cylinder (110) and transmit it to the control unit (700) as CAN data, for example.

For example, if an input of 1,000 mV to 5,000 mV becomes an output of 0 to 250 bar and a CAN message is required to be sent in units of 1 bar, the logic can use 250/4000 = 0.0625 bar/mV resolution for calculation.

That is, the pressure sensor unit (300) transmits a pressure signal to the control unit (700) in real time, converts the signal transmitted from each outrigger unit (100) into a load value, and then monitors the center of gravity of the crane in real time, and operates the valve through the control unit (700) to limit the operation of the boom (20), etc., so that the crane does not move and thus avoids overturning.

The pressure can be checked and set to the initial value when the outrigger part (100) is not unfolded, and the pressure can be checked and set to the maximum value when the outrigger part (100) is unfolded to the maximum.

In this case, the intermediate value increases or decreases proportionally due to the influence of the moment between the maximum and minimum values, so the amount of expansion of the outrigger part (100) can be known by comparing the maximum and minimum values.

Meanwhile, the horizontal angle sensor unit (500) is mounted on the outrigger unit (100) and serves to measure the horizontal inclination of the outrigger unit (100).

The horizontal angle sensor unit (500) is located on multiple outrigger units (100) and has the function of measuring the angle when the angle of the support unit is adjusted.

The angle measured at this time may be the angle between the support and the ground, and if the support of the outrigger part (100) is located on flat ground, the angle measured by the horizontal angle sensor part (500) is 0°.

The control unit (700) receives the measurement value of the horizontal angle sensor unit (500), and when the overturning moment that overturns the crane is activated by lifting the object, it controls the operation of the hydraulic cylinder (110) and the crane according to the input measurement value to stop or avoid the operation.

That is, when the crane lifts an object, the crane may overturn, and the horizontal angle sensor unit (500) first measures the angle and transmits it to the control unit (700).

Then, the control unit (700) receives the measured angle and determines whether the overturning moment that overturns the crane is activated.

If an overturning moment that overturns the crane is activated, the control unit (700) controls the operation of the hydraulic cylinder (110) and the crane.

The control unit (700) is a device that receives a signal from the pressure sensor unit and monitors the calculation and change of the center of gravity. It receives a signal regarding the pressure of the cylinder detected from the pressure sensor unit (300) and can convert it into a load value, etc. by a conversion program.

Using these load values, the movement of the boom (20) in the crane can be blocked or limited.

The control unit (700) has a parameter variable that can be set so that it can receive a signal from the pressure sensor unit (300) and convert the pressure into a load value according to the size of the hydraulic cylinder (110) installed inside the outrigger unit (100), and can monitor the change in the center of gravity of the crane in real time based on the collected load information of each outrigger unit (100).

In addition, the motion limiting device is activated through the control unit (700) to stop the crane from operating any further, and the outrigger unit (100), boom (20), and swing can be selectively or compositely operated within a limited range.

Meanwhile, in order to determine whether an overturning moment that overturns the crane has occurred, it can be determined whether the horizontal angle sensor unit (500) has exceeded a preset threshold angle.

That is, this function is used when judging whether the crane itself is lifted or not. For example, if the body is tilted by 5° or 10°, the crane may overturn. This angle is determined in advance, and it is obvious that the scope of the present invention is not limited thereto.

If the angle of the support portion of multiple outrigger parts (100) is greater than the critical angle, it can be determined that the support portion is not properly anchored to the ground, the support portion is floating in the air separated from the ground, or a part of the support portion is separated from the ground.

Next, in order to determine whether an overturning moment that overturns the crane has occurred, it can be determined whether the pressure of the pressure sensor unit (300) is less than a preset threshold pressure.

The occurrence of a crane overturn can also be detected through pressure in the hydraulic cylinder section of the outrigger section (100).

For example, if the pressure of one of the four hydraulic cylinders (110) drops from 100 bar to 0 bar, the pressure balance of the outrigger section (100) may be lost, causing it to capsize.

Therefore, the pressure value of each hydraulic cylinder can be compared and the operation of the crane can be controlled if it exceeds a predetermined balance value set by the control unit (700).

These balance values can be set so that the average and standard deviation of multiple cylinder pressure values can be calculated as predetermined values and compared with a specific cylinder pressure value.

If the pressure inside the chamber of a plurality of outrigger parts (100) is lower than the critical pressure, it can be determined that the parts are not properly seated on the ground, the support parts are separated from the ground and floating in the air, or a part of the support parts is separated from the ground.

In this way, through the critical pressure, it is possible to determine whether the support parts of the multiple outrigger parts (100) are properly anchored to the ground and properly support the crane from the ground, and it is possible to determine whether an overturning moment that overturns the crane occurs.

Therefore, the occurrence of the overturning moment is judged based on whether the pressure of the four hydraulic cylinders (110) is less than the preset critical pressure.

If such a critical pressure is reached, the withdrawal and retraction movements of the telescopic part (900) of the crane can be restricted, or the lifting movement of the winch can be restricted.

For example, the flow rate control of the outrigger part (100) requires a maximum of 25 LPM (liter per minute) per unit, and 100 LPM when a maximum of 4 units are selected. The flow rate value can be set in various ways, and it is obvious that the scope of the present invention is not limited thereto.

Meanwhile, the operation of the outrigger part (100) can be controlled by EPFC (Electronic Pump Flow Control).

That is, as will be described later, the MCU applies proportional control to the FEH type MCV to increase or decrease the maximum speed of the crane equipment, thereby enabling a flexible stop.

In addition, it is possible to prevent the crane from moving even when the operator changes the joystick, and to make the crane equipment stop softly without applying a large impact when it stops.

For reference, in one embodiment of the present invention, a variable capacity pump is used, and the setting is possible by controlling the inclination angle of the swash plate.

A variable displacement pump varies the hydraulic fluid discharge according to the pressure requirement of the hydraulic system, and the pump's delivery volume can be changed by a pump compensator inside the piston.

Additionally, it includes a function to stop or limit the movement of the boom mounted on the crane.

Therefore, if the overturning moment operates, the control unit (700) can limit the operation of one or more of the winch drum (not shown), the derrick cylinder (26), and the telescopic unit (900) mounted on the crane.

Specifically, in the case of a winch drum (not shown), two main and sub winches can be installed, and the ascent of these winches can be limited, and in the case of a derrick cylinder (26), the descent can be limited, and the extension movement of the telescopic part (900) can be limited.

Meanwhile, the control unit (700) can limit the operation of the crane to a certain level even with respect to the operation input of the crane through proportional control.

No matter how much the crane operator pushes or pulls the joystick that operates the crane, the movement will stop, and the crane will stop flexibly without any shock.

Previously, a method for preventing overturning was conceived by sensing the amount of expansion of the outrigger part (100) using a stroke sensor, but according to the present invention, since the amount of expansion of the outrigger part (100) is sensed using a pressure sensor, a configuration such as a stroke sensor is eliminated, so the system can be configured in a simple and cost-saving manner.

For example, the calculation of the overturn rate is calculated by calculating the pressure of each outrigger (100) pressure sensor as 100% 5 seconds after the initial outrigger operation when the Seat S/W is input, and when the pressure in each cylinder is input to "0" bar during crane operation, it is converted to 0% and used.

When pressure exceeding the setting pressure is detected, it is 100%, and when pressure below the setting pressure, percentage can be applied. There are pressure sensors in a total of 4 outriggers, and among each pressure sensor, the one with the largest decrease in change amount (%) is calculated and output and sent to CAN data.

The outrigger (100) angle sensor can sense the inclination value of the body and transmit it to the crane system as CAN data.

If the overturn rate is 91% or higher, reduce it to 10% (Max current - Minimum current) from the initial 100% to 100%.

And when the top seat S/W is initially input, joystick and fingertip inputs are restricted for 10 seconds (tuning variable), after which the overturning rate is set using the outrigger (100) pressure sensor, and then work can begin.

Referring to the electro-hydraulic MCV circuit diagram in Figure 2, a spool valve can be added to control direction and flow rate by moving the internal spool when the left/right pilot pressure is input.

In particular, a compensator may be added to maintain the differential pressure of the component. The main compensator (810) is a logic valve that receives load sensing input and maintains a certain differential pressure, and the sub compensator (830) has the function of maintaining the differential pressure for each function.

A relief valve (850) can be added here to limit the maximum pressure of the MCV.

Comparing the present invention with the existing MCV circuit diagram, the existing one is configured without a pre-compensator by the operation of the manual lever, so the operation is performed abruptly in sections in a discontinuous manner, which causes a lot of shock, but the present invention has been improved to reduce such shock and enable flexible operation.

Referring to the electro-hydraulic outrigger circuit diagram of Fig. 3, an extension and retraction cylinder (111) may be installed in the outrigger (100), and a jack up-down cylinder (113) for raising or lowering the jack may be installed in the outrigger (100).

A holding valve (115) is installed in the jack up/down cylinder (113) to perform a locking function to prevent natural lowering of the outrigger.

In this electro-hydraulic outrigger circuit diagram, a directional control valve (117) for electronically controlling the extension of the outrigger jack may be installed, and a flow control valve (119) for electronically controlling the speed of the outrigger when it is operated through the input of the joystick may be installed.

Additionally, a flow control valve (119) is installed so that residual pressure in the outrigger can be removed.

In addition, as another embodiment of the present invention, if a pressure sensor is additionally installed at the bottom of each outrigger part (100) jack cylinder after removing the residual pressure relief solenoid valve and check valve, the pressure applied to the upper part, such as the tube side of the outrigger part jack cylinder, due to the load can be known by using the area ratio, and thus the overturning pressure can be converted by using this pressure (upper pressure - lower part X area ratio).

This configuration eliminates the need for additional piping, check valves, solenoid valves, etc., thereby improving the problem of abnormal descent due to failure of internal components such as conventional solenoid valves and check valves.

The technical features disclosed in each embodiment of the present invention are not limited to that embodiment, and, unless they are mutually incompatible, the technical features disclosed in each embodiment may be combined and applied to different embodiments.

Therefore, each embodiment will focus on explaining each technical feature, but unless each technical feature is incompatible with each other, it can be applied in combination with each other.

The present invention is not limited to the above-described embodiments and the attached drawings, and various modifications and variations are possible from the viewpoint of those skilled in the art to which the present invention pertains. Therefore, the scope of the present invention should be determined not only by the claims of this specification but also by the equivalents of these claims.

10: Crane overturn prevention device 100: Outrigger
300: Pressure sensor part 500: Horizontal angle sensor part
700: Control Unit 800: Compensator
900: Telescopic section

Claims (5)

A device that lifts objects and is equipped with a crane on a mobile body.
A plurality of outriggers supporting the above movable body, each of which includes a hydraulic cylinder therein;
A pressure sensor unit provided on one side of the hydraulic cylinder to detect pressure generated from the hydraulic cylinder:
A horizontal angle sensor unit mounted on the above outrigger unit to measure a horizontal inclination with respect to the outrigger unit; and
A crane overturn prevention device including a control unit that receives a measurement value of the horizontal angle sensor unit and controls the operation of the hydraulic cylinder and the crane according to the received measurement value when an overturning moment that overturns the crane is activated by lifting a salvage object.
In the first paragraph,
Judgment on whether the above overturning moment has occurred is as follows:
A crane overturn prevention device that determines whether the horizontal angle sensor section exceeds a preset critical angle and pressure sensor.
In the first paragraph,
Judgment on whether the above overturning moment has occurred is as follows:
A crane overturn prevention device that determines whether the pressure of the pressure sensor section is below a preset threshold pressure.
In the first paragraph,
The operation of the above control unit is:
A crane overturn prevention device that restricts the movement of one or more of a winch drum, a derrick cylinder, and a telescopic section mounted on the above crane.
In paragraph 5,
The operation of the above control unit is:
A crane overturn prevention device that limits the operation of a crane even when the crane's operation input is used by using proportional control.