JP2001019364A - Crane arrangement - Google Patents

Abstract

PROBLEM TO BE SOLVED: To precisely detect the whole length of an extension boom without being affected by snowfall, rainfall and wind, in a crane wherein a boom body is supported onto an equipment body to be freely turned up and down by a hydraulic cylinder, and wherein the extension boom extended multistagedly along an axial direction is stored in the boom body to be freely extendable. SOLUTION: A target 24 for reflecting an electromagnetic wave is provided in one side out of a boom body 3A and a tip part of an extension boom 5, and a transmitter 23 faced to the target 24 to emit an electromagnetic wave for removing light and a receiver 25 for receiving the reflected electromagnetic wave reflected by the target 24 are provided in the other side. A boom length of the extension boom 5 is operated by a controller 9A based on a required time from an electromagnetic wave transmission starting time in the transmitter 23 to a reflected wave receiving time in the receiver 25, and based on a velocity of the electromagnetic wave.

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a crane device having a telescopic boom for expanding a maximum working range and transferring a load to a high place, and more particularly to a crane device configured to detect a boom length by electromagnetic waves. The present invention relates to a crane device that has been used.

[0002]

2. Description of the Related Art FIG. 5 shows a conventional crane 1 of this kind, in which a base end of a boom main body 3A is pivotally supported at the rear of a body 2 so that the boom main body 3A can be raised and lowered.
In order to set the boom angle, the front of the body 2 and the tip of the boom body 3A are connected by a double-acting hydraulic cylinder 4.

[0003] In order to make it possible to adjust the range of loading and unloading work of the crane 1, a telescopic boom 5 is stored in the boom main body 3A so as to be extendable and contractible in the boom axis direction.

The boom body 3A further includes a boom angle detecting means 6 for detecting a boom angle θ, a boom load detecting means 7 for detecting a boom load acting on the boom, and a telescopic boom 5 A boom length detecting means 8 for detecting the amount is provided, and these detection signals are output to a controller 9 to detect the detected value and a known value (the stability moment of the body, the center of gravity of the body, the boom length of the telescopic boom 5 and (The permissible maximum boom hanging load at each point based on the boom angle θ, the permissible maximum moment at each point based on the boom length of the telescopic boom 5 and the boom angle θ, the length of the boom body, and other known values such as the section modulus) , The working radius of the load and the load of the suspended load are obtained.

[0005] The controller 9 is configured to output a calculation signal to a display means 10 in the cabin.
In addition, the display means 10 displays when the boom hanging load based on the expansion and contraction of the telescopic boom 5 exceeds the allowable maximum boom hanging load.
A warning signal is output to the display means 10 and the buzzer 11 to warn.

Therefore, for the safe and efficient cargo handling work, the various detecting means 6, 7, 8, and 10 and the controller 9 are indispensable, and it is desirable to use a highly accurate device.

Therefore, conventionally, a pressure detector 7 attached to the hydraulic cylinder 4 and the cylinder body 4A is interposed as a boom load detecting means, and a potentiometer 14 is attached to the boom main body 3A as a boom angle detecting means. .
Further, the boom length detecting means is constituted by a mechanical code reel 18.

In this example, the cord reel 18 is provided with a measuring rope 17 fed from a drum (not shown) of the cordle reel 18 attached to the boom main body 3A along the side surface of the boom main body 3A. After being guided to the tip, the measurement rope 17 is guided by the guide ring 1 at the tip of each of the booms 5A, 5B, 5C constituting the telescopic boom 5.
The boom length of the telescopic boom 5 is determined by a detection value of a potentiometer (not shown) and fixed to the end of the boom through 8A, 18B, 18C.

[0009]

However, in a device for mechanically detecting the boom length by the measuring rope 17, the measuring rope 17 may be expanded, contracted, bent or deformed due to a temperature change.
Due to the vibration of the measuring rope 17 due to the wind pressure load and the wear of the mechanical encoder 18, there is a possibility that the detected values may vary, so that there is a drawback that accuracy is lacking. For this reason, the maximum boom hanging load at each hanging point of the boom is set low to ensure safety, and periodic maintenance must be performed for failure and wear of the mechanical encoder 18. .

Therefore, a reflector is provided on one of the boom body 3A and the distal end of the telescopic boom 5,
This type of problem can be solved by disposing a distance measuring device that measures the distance by light or ultrasonic waves on the other side of the boom main body 3A or the telescopic boom 5 and measuring the boom length in a non-contact manner. Attempts have been made to shine light on the reflector,
It is easily affected by the adverse effects of snowfall, rainfall, and fog, and ultrasonic waves may be swept away by wind, and none of them is adopted.

Therefore, there arises a technical problem to be solved for accurately detecting the entire length of the telescopic boom without being affected by snowfall, rainfall, wind and fog. The present invention solves the problem. The purpose is to solve.

[0012]

SUMMARY OF THE INVENTION The present invention has been proposed in order to achieve the above-mentioned object, and a base of a boom body is rotatably supported on a revolving body around a horizontal axis. A crane device provided with a hydraulic cylinder that supports the boom body so that the boom body can be raised and lowered, and further provided with a telescopic boom that expands and contracts in the boom axis direction in the boom body, and a hydraulic cylinder that expands and contracts the boom on the telescopic boom, A target is provided on one of the boom main body side and the telescopic boom side to reflect an electromagnetic wave, and an electromagnetic wave (excluding light) is emitted facing the target at the other of the boom main body side and the telescopic boom side. A transmitter and a receiver for receiving the electromagnetic wave reflected from the target are provided, and further, when the reflected wave of the receiver is received from the start of the electromagnetic wave transmission of the transmitter. A crane device provided with a calculating device for calculating the length of expansion and contraction of the telescopic boom based on the required time and the speed of the electromagnetic wave, boom load detecting means for detecting a boom load of the boom body, and the boom angle Boom angle detection means for detecting the boom working radius, boom load, boom hanging load by a calculation with a boom angle as a calculation element, the calculation means,
When the boom hanging load exceeds the allowable maximum hanging load, the extension of the hydraulic cylinder for expanding and contracting the telescopic boom is stopped, or the movement of the hydraulic cylinder for lowering the boom body to the falling side is stopped. A crane device configured to output a stop signal to an actuator that turns the revolving unit when the calculated lifting load exceeds the allowable maximum lifting load. An apparatus is provided.

[0013]

DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS An embodiment of the present invention applied to a self-propelled crane having a telescopic boom will be described below in detail with reference to FIGS. It is to be noted that the same components as those of the related art are denoted by the same reference numerals.

FIG. 1 shows a self-propelled crane 21 whose length is set by the expansion and contraction of each of the boom elements 5A, 5B and 5C constituting the telescopic boom 5 and the boom angle θ is set by the expansion and contraction of the double-acting hydraulic cylinder 4. Set. The boom body 3A is provided with a pressure detector 7 as a boom load detecting means for detecting a boom load.
The potentiometer 14 is provided. And
Boom length detecting means 22 is provided on the boom body 3A and the telescopic boom 5 to detect the boom length of the telescopic boom 5.

The boom length detecting means 22 reflects a pulse-modulated electromagnetic wave (excluding light), for example, a centimeter wave, a millimeter wave, etc., via a transmission antenna 26 and a target (reflection plate) 24. Incoming electromagnetic waves (reflected waves)
And a receiver 25 that receives the signal via the reception antenna 27. The transmitter 23 and the receiver 25 are arranged side by side adjacent to each other at the tip of the boom body 3A, while the target 24 The electromagnetic wave (excluding light) emitted from the antenna 26 and the reflected wave received by the receiving antenna 27 are disposed at right angles to the gonad.

The receiver 25 is electrically configured to amplify and detect (demodulate) the reflected wave input via the receiving antenna 27. The controller 9A is connected to the transmitter 23 and the receiver 25 via signal cables, respectively, and uses a distance detecting means 28 that integrates the number of pulses from the time of transmission to the time of reception of the electromagnetic wave using its internal counter. A distance signal output means 29 for converting the operation value calculated by the distance detection means 28 into a signal and outputting the signal, a distance signal output from the distance signal output means 29, and a boom load (support force) corresponding to the support pressure. ) When a signal and a boom angle signal corresponding to the boom angle θ are output, an overboom load of the crane 21 is determined by calculation, and at the time of the overboom load, a control signal is sent to boom overload prevention means (described later). And an arithmetic means 30 for outputting the following.

First, the controller 9A calculates the total length L of the telescopic boom 5 from the time difference from the start of transmission to the reception of the signal from the signal from the distance detection means 28, that is, the round trip time T to the target, based on the following equation (1). L = C × T / 2 (1) where T is the round trip time of the electromagnetic wave C is the speed of the electromagnetic wave Next, the total length L of the telescopic boom 5 and the boom angle detection means 6 output Boom angle θ and known values (the stable moment of the body, the center of gravity of the body, the allowable maximum boom hanging load at each point based on the boom length and the boom angle θ of the telescopic boom 5, the boom length and the boom angle θ of the telescopic boom 5 The maximum allowable moment at each point, the total length of the boom body 3A, and other factors such as the section modulus) are read out from the reference table of the memory as calculation elements, and then the working radius of the telescopic boom 5 is calculated. , It calculates the boom hanging load.

The calculated working radius R of the telescopic boom 5 is
If the maximum allowable lifting load at the suspension point is exceeded, the extension of the hydraulic cylinder (described later) for extending the telescopic boom 5 is stopped to stop the telescopic boom 5, or the boom body 3A falls down. The reduction of the hydraulic cylinder 4 is stopped, and the lowering of the boom body 3A is stopped. When the suspended load exceeds the allowable maximum suspended load when the upper revolving unit 16 turns, the drive of the hydraulic motor 34 (see FIG. 4) for revolving the upper revolving unit 16 is operated to stop the upper revolving unit 16. To improve safety.

As described above, in the present embodiment, the boom length L is detected in a non-contact and accurate manner by the transmission and reception of electromagnetic waves (excluding light) without being affected by disturbances such as rainfall, snowfall, wind and dirt. The operation of the controller 9A based on the length L and the various operation elements stored in advance determines the working radius R of the boom 3 and the allowable maximum suspension load of the load corresponding to the operation radius R, and calculates the suspension for the allowable maximum suspension load. The extension of the hydraulic cylinder (to be described later) for extending and retracting the telescopic boom 5 is stopped based on the comparison of the load, or the reduction of the hydraulic cylinder for lowering the boom main body 3A is stopped. When the swing load exceeds the allowable maximum suspension load during the swing of the swing motor, the swing motor is operated / stopped. For this reason, it is possible to carry out the cargo handling work safely and quickly with the maximum capacity.

The above-mentioned modulation method is not limited to the pulse modulation, but may be another FM-CW method, a two-frequency C
It is configured to use the W method and the spread spectrum method,
Then, the total length L of the telescopic boom 5 and the boom turning radius R may be determined by equations corresponding to each system.

FIG. 2 shows an operating hydraulic circuit 31 for controlling the operating hydraulic circuit 31 of the telescopic boom 5 which expands and contracts in three stages by the controller 9A. Each of the boom elements 5A, 5B, 5C constituting the telescopic boom 5 includes: A double-acting hydraulic cylinder 32, 33, 34 is attached, and a hydraulic circuit 31 for operating the double-acting hydraulic cylinders 32, 33, 34 has a directional control valve 3 comprising a three-chamber 6-port switching valve.
5 and an electromagnetic valve 37, and the expansion and contraction of the telescopic boom 5 can be performed in three stages by switching between the valves 35 and 37. A relief valve 41 for relieving pressure oil to a drain 40 is interposed between the oil pump 39 for supplying hydraulic oil to the operating hydraulic circuit 31 and the direction control valve 35, A valve opening pressure setting port 42 for setting a valve opening pressure of 41 can be connected to the drain 40 via a vent relief valve (overload prevention means) 43.

When the suspension load calculated by the above calculation exceeds the allowable maximum suspension load at the suspension point, the controller 9A cuts off the supply of the excitation signal to the vent relief valve 43 and disconnects the vent port 44 and the drain 40.
Are communicated with each other to release the control pressure for the relief valve 41, and when the suspension load obtained by the calculation is equal to or less than the allowable maximum suspension load at the suspension point, an excitation signal is transmitted to the vent relief valve 43. The valve pressure is supplied to cut off the communication between the vent port 44 and the drain 40 to apply a circuit pressure to the valve opening pressure setting port 42.

Therefore, it is possible to extend the telescopic boom 5 until the hanging load of the telescopic boom 5 becomes equal to the allowable maximum hoisting load. When the hoisting load exceeds the allowable maximum hoisting load,
By returning the telescopic boom 5 slightly, the maximum boom radius L
Can be unloaded. Therefore, safety and work efficiency are significantly improved as compared with the related art.

FIG. 3 shows the boom body 3A by switching the expansion and contraction of a double-acting hydraulic cylinder 4 for raising and lowering the boom body 3A.
Shows an operating hydraulic circuit 31 for controlling the undulation. The hydraulic circuit components described with reference to FIG. 2 are omitted for convenience of description. As shown in the figure, the operating hydraulic circuit 31 is configured so that the hydraulic cylinder 4 for raising and lowering the boom main body 3A expands and contracts by switching a direction control valve (three-chamber 6-port switching valve) 55. A relief valve 56 for relieving pressure oil is provided in the drain 40 between the oil pump 39 and the direction control valve 55, and the drain 4
A valve-opening pressure setting port 58 for setting the valve-opening pressure of the relief valve 56 is communicated with a zero through a vent relief valve (overload prevention means) 57.

In this example, when the suspension load based on the above calculation exceeds the allowable maximum suspension load, the controller 9A shuts off the supply of the excitation signal to the vent relief valve 57 and disconnects the vent port 59 and the drain 40.
And, as a result, the relief valve 56
When the load is equal to or less than the allowable maximum suspension load, an excitation signal is supplied to the vent relief valve 57 to cut off the communication between the vent port 59 and the drain 40, and as a result, The valve opening pressure setting port 58 is configured to act on the circuit pressure.

Accordingly, the boom 3 is caused to fall down until the suspended load of the boom 3 becomes equal to the maximum allowable suspended load, and the cargo can be loaded at an optimum boom angle. Further, as described above, since the controller 9A detects the length of the boom in a non-contact manner using electromagnetic waves other than light as a detection wave, the controller 9A does not have an influence of disturbance such as rainfall, snowfall, wind, and dirt. Calculate the lifting load accurately. For this reason,
Crane 2 compared to conventional mechanical boom length detection means
1 can be safely driven with maximum capacity.

FIG. 4 shows an operating hydraulic circuit 46 of a swing motor (hydraulic motor) 45 for swinging the upper swing body 16.
The rotation of the rotation motor 45 is rotated forward and reverse by switching between the normal rotation and the reverse rotation by the operation lever 47, and the transmission of the rotational driving force to the rotation motor 45 is stopped by returning the pressure oil to the drain 40 by the neutral switching. I do. The pilot oil passages 49 and 50 for switching the direction control valve 48 are connected to the pilot operation circuit 51 of the operation lever 47, respectively.
1 and the drain 40 are connected by an openable / closable solenoid valve (overload prevention means) 52, and the solenoid valve 52 is electrically connected to the controller 9A.

In this case, the controller 9A outputs an open signal to the solenoid valve 52 when the suspension load obtained by the above calculation exceeds the allowable maximum suspension load at the suspension point. 51 and drain 4
0, the switching position of the direction control valve 48 is returned to the neutral position, and the pressure oil supplied to the turning motor 45 is returned to the drain 40 on the upstream side.

Therefore, the swing motor 45 is controlled by the operation lever 4
The switching operation of Step 7 is made substantially invalid, the turning motor 45 is stopped, and the turning of the upper turning body 16 on which the telescopic boom 5 is mounted is stopped. For this reason, the turning of the upper revolving unit 16 is allowed until the hanging load of the telescopic boom 5 becomes equal to the allowable maximum hanging load. When the hanging load is equal to the allowable maximum hanging load, the turning of the upper turning body 16 is automatically performed. regulate. When the suspension load falls within the allowable maximum suspension load due to the ups and downs of the boom 3 and the extension of the telescopic boom 5, the vehicle can be turned again. Therefore, the stop control of the turning motor 45, the extension boom 5
The safety can be improved as much as possible by using the expansion / contraction control of the boom 3 and the up / down control of the boom 3, and an accident due to an erroneous operation can be prevented beforehand.

The present invention can be variously modified without departing from the spirit of the present invention, and it goes without saying that the present invention extends to the modified ones.

[0031]

According to the first aspect of the present invention, a target for reflecting an electromagnetic wave is provided on one of the boom main body and the tip of the telescopic boom, and the other is for transmitting an electromagnetic wave excluding light facing the target. And a receiver for receiving electromagnetic waves reflected from the target. For this reason, the boom length of the telescopic boom can be accurately detected without contact irrespective of snowfall, rainfall, fog, and target contamination, and the cargo can be efficiently loaded with the maximum capacity. Further, the present invention is very effective in that it is non-contact and resistant to contamination of the target, so that maintenance-free operation can be achieved.

According to a second aspect of the present invention, the extension of the hydraulic cylinder for expanding and contracting the telescopic boom is stopped, or the movement of the hydraulic cylinder for lowering the boom body to the falling side is stopped. As a result, the present invention has a truly remarkable effect, for example, it is possible to improve the safety and reliability of the crane handling operation as much as possible.

According to a third aspect of the present invention, the calculation means is configured to output a stop signal to an actuator that turns the revolving unit when the calculated suspension load exceeds the allowable maximum suspension load. Therefore, it is an invention that exhibits a truly significant effect, such as the ability to carry out cargo handling more safely.

[Brief description of the drawings]

FIG. 1 is a side view showing a self-propelled crane having a telescopic boom and a boom length detecting means according to an embodiment of the present invention.

FIG. 2 is a hydraulic circuit diagram showing an embodiment of the present invention and showing an operating hydraulic circuit of a hydraulic cylinder for operating a telescopic boom of a crane that expands and contracts in three stages.

FIG. 3 is a hydraulic circuit diagram showing an embodiment of the present invention and showing an operating hydraulic circuit of a double-acting hydraulic cylinder that raises and lowers a boom main body.

FIG. 4 is a hydraulic circuit diagram showing an embodiment of the present invention and showing an operating hydraulic circuit of a swing motor for swinging a swing body of a crane equipped with a telescopic boom.

FIG. 5 is a side view showing a conventional example and showing a self-propelled crane having a telescopic boom.

[Explanation of symbols]

 3A boom body 5 telescopic boom 9A controller (computing means) 23 transmitter 24 target 25 receiver

Claims (3)

[Claims] 1. A hydraulic cylinder for supporting a base of a boom main body on a revolving body so as to be rotatable around a horizontal axis and supporting the boom main body on the revolving body so as to be able to move up and down.
In a crane apparatus provided with a telescopic boom that expands and contracts in the boom axis direction on the boom main body and a hydraulic cylinder that expands and contracts the boom on the telescopic boom, electromagnetic waves are reflected on either the boom main body side or the telescopic boom side. A transmitter for emitting an electromagnetic wave (excluding light) facing the target on the other side of the boom body or the telescopic boom, and a receiver for receiving the electromagnetic wave reflected from the target. Provided, further comprising an arithmetic device for calculating the length of expansion and contraction of the telescopic boom based on the required time and electromagnetic wave speed from the start of electromagnetic wave transmission of the transmitter to the time of reception of the reflected wave of the receiver. Crane equipment characterized. 2. A boom load detecting means for detecting a boom load of the boom main body, and a boom angle detecting means for detecting the boom angle, wherein the calculating means includes at least a boom working radius, a boom load, and a boom angle. The boom hanging load is calculated by a calculation using as a calculation element, and when the boom hanging load exceeds the allowable maximum hanging load, the extension of the hydraulic cylinder for expanding and contracting the telescopic boom is stopped, or the boom main body falls down. 2. The crane device according to claim 1, wherein the hydraulic cylinder is configured to stop the movement of the hydraulic cylinder toward the falling side. 3. The system according to claim 1, wherein the calculating means outputs a stop signal to an actuator that turns the revolving body when the calculated lifting load exceeds the allowable maximum lifting load. The crane device as described.