JPH0314757B2 - - Google Patents

Description

DETAILED DESCRIPTION OF THE INVENTION The present invention automatically corrects the drive pressure of the hydraulic motor by the amount of turning moment generated by the slope when turning a hydraulic crane on a slope, and enables the same turning operation on a slope as on a flat land. The present invention relates to a swing control device for a hydraulic crane that can be operated.

In general, a hydraulic crane generally consists of a crane in which a lower traveling body is provided with an upper rotating body so as to be able to rotate, and a boom is attached to the upper rotating body, and a valve control open circuit for driving the upper rotating body to rotate. The valve control open circuit includes, for example, a fixed displacement hydraulic pump, a hydraulic motor that rotates the upper revolving structure, a pilot valve that generates secondary pressure as pilot pressure according to the amount of operation of the operating lever, and a secondary It is composed of a control valve that has a pressure reducing function that converts pressure into pilot pressure, and controls the flow direction and drive pressure of pressure oil from the hydraulic pump to the hydraulic motor using the pilot pressure from the pilot valve, and the hydraulic pump and hydraulic It is connected to the motor via a control valve. and,
As the control valve, for example, a center bypass type three-position directional switching valve having a pressure reducing function is used.

As described above, the upper revolving body control circuit of a hydraulic crane that employs a valve control open circuit is an open circuit control system, in which the secondary pressure of the pilot valve is controlled by the operating lever, and the control circuit is controlled by the secondary pressure. Control the valve.
Therefore, by controlling the drive pressure to the hydraulic motor by changing the secondary pressure of the pilot valve using the operating lever and adjusting the opening degree of the control valve, it is possible to change the rotation speed of the hydraulic motor. can. Also,
When the operating lever is in the neutral position, the pilot valve and control valve are also in the neutral position, and both the inflow and outflow sides of the hydraulic motor are connected to the tank and are in a tank pressure state. It also has the characteristics of being able to swivel and perform so-called "driving operation," while automatically aligning the upper revolving structure when lifting a suspended load from the ground, a so-called "ground cutting." ing. This characteristic is essential for the turning characteristics of a hydraulic crane.

By the way, although hydraulic cranes often work on flat land, depending on the situation at a construction site, etc., they may be installed and worked on sloped land. In this case, in a hydraulic crane that employs the swing valve control open circuit described above, when the operating lever is in the neutral position, both the inflow and outflow sides of the hydraulic motor are at tank pressure. If the parking brake is left inactive, a turning moment will be generated in the upper revolving structure due to the loads of the upper revolving structure, boom, hanging load, etc., and the upper revolving structure will move downwards on the slope against the operator's will. It has the disadvantage of turning towards the target.

In addition, in the turning valve control open circuit, the drive pressure of the hydraulic motor is controlled by the operating lever, but when turning to the right and turning to the left, when turning to the uphill side and when turning to the left. When turning down a slope, the load torque of the hydraulic motor differs by "turning moment x 2". As a result, the operability of the control lever varies greatly, making it extremely difficult to operate, which not only increases operator fatigue, but also has the disadvantage that there is a high possibility that dangerous conditions such as load swinging may occur. There is.

The present invention was developed in view of the above-mentioned drawbacks of the prior art, and when operating a hydraulic crane on a slope, it automatically corrects the drive pressure of the hydraulic motor by the amount of turning moment generated by the slope. By making it possible to perform the same turning operation as on flat ground, when the operating lever is in the neutral position, it is possible to maintain the upper revolving structure neutrally, thereby improving the safety of drifting operation and ground cutting on sloped ground. This is a hydraulic crane that is able to maintain the same amount of operation of the operating lever when going up and down slopes, is easy for the operator to operate, and can prevent the occurrence of load swing. The purpose of the present invention is to provide a swing control device.

In order to achieve the above object, the features of the configuration adopted by the present invention include a boom angle detector that detects the boom angle, a load detector that detects the load of the load suspended by the boom, and a crane in the longitudinal and lateral directions. an inclination angle detector that detects the inclination angle of the upper rotating body; an operating lever detector that detects the operating amount of the operating lever that performs the swing operation of the upper rotating structure; and an electric-hydraulic system that supplies pilot pressure corresponding to the signal amount to the control valve. a conversion valve; and a calculation device that receives signals from each of the detectors and outputs a control signal to the electro-hydraulic conversion valve, and the calculation device is configured to control the boom angle detector, the load detector, and the inclination angle. By inputting each detection signal from the detector, a calculation is performed to obtain a correction amount for the driving pressure of the hydraulic motor corresponding to the torque generated by the tilting of the crane, and then the detection signal from the operating lever detector is input. A calculation is performed to obtain a new motor drive pressure on a slope by adding the command pressure of the operating lever based on the above and the correction amount of the drive pressure, and the new motor drive pressure is added to operate the control valve. The present invention is configured to perform a computation to output a corresponding control signal to the electro-hydraulic conversion valve.

Hereinafter, the present invention will be described in detail based on embodiments shown in the drawings.

1 to 5 show a first embodiment of the invention.

In the figure, 1 is a crane, and the crane 1 includes a lower traveling body 2, an upper rotating body 3 rotatably provided on the lower traveling body 2, and a boom provided on the upper rotating body 3 so as to be movable up and down. It is roughly composed of 4. The boom 4 can be moved up and down via a hoisting rope 6 and a pendant rope 7 wound around the gantry 5, and a hoisting rope 8,
A suspended load 10 can be lifted and hung via a hook 9.

Next, referring to the valve control open circuit for driving the upper revolving body 3, 11 is a hydraulic pump driven by a power source (not shown) such as an engine or an electric motor, and 12 is a load for the upper revolving body. A hydraulic motor rotates the body 3 together with the boom 4, etc., and 13 is a hydraulic pilot type control valve.The control valve 13 is, for example, a center bypass type 3-position directional switching valve having a pressure reducing function. In addition to the pilot pressure being input, the secondary side pressure of the control valve 13 is also input via the hydraulic pilots 13A' and 13B', thereby performing feedback control. Further, 14 is a drive circuit connected between the hydraulic pump 11 and the control valve 13, 15 is a return circuit connected between the control valve 13 and the tank 16, and 17A and 17B are the outflow side of the control valve 13. A drive circuit 18 is an unload circuit connected between each inlet and outlet of the hydraulic motor 12. By switching the control valve 13 to the switching position A or B, the drive circuit 14 is switched to the drive circuit 17B or 17A of the hydraulic motor 12, and pressure oil is supplied to the hydraulic motor 1 according to the switching stroke.
2 and rotate forward and reverse. On the other hand, the control valve 13
is in the neutral position, the drive circuit 14 of the hydraulic pump 11 is connected to the tank 16 via the unload circuit 18, and the drive circuits 17A, 17B of the hydraulic motor 12 are connected to the tank 16 via the return circuit 15. The entire amount of pressure oil from the hydraulic pump 11 is returned to the tank 16, and the hydraulic oil is returned to the hydraulic motor 12.
communicates with the tank 16, and the upper revolving body 3 can rotate due to inertial load and gradually come to a stop. In the figure, 1
9 is a relief valve that sets the maximum pressure of the drive circuit 14; 20A and 20B are a return circuit 15 and drive circuits 17A and 17B to prevent cavitation on the low pressure side when the control valve 13 rotates in the neutral position;
This is a check valve installed between the and,
The valve control open circuit constructed as described above is essentially the same as the prior art.

Further, 21A and 21B are electro-hydraulic conversion valves for supplying a pilot pressure proportional to the magnitude (voltage or current amount) of a control signal from an arithmetic unit, which will be described later, to hydraulic pilots 13A and 13B of the control valve 13. As the electro-hydraulic conversion valves 21A and 21B, for example, electromagnetic proportional valves that generate hydraulic pressure proportional to the magnitude of the electric signal amount are used (hereinafter referred to as electro-hydraulic valves).
The hydraulic conversion valves 21A and 21B are
A, 21B”). And the electromagnetic proportional valve 21
A, 21B has the pilot pump 2 on its inflow side.
2 and the outflow side is connected to each hydraulic pilot 13A, 13B of the control valve 13, and when no signal is input to the solenoid section, the hydraulic pilots 13A, 13B are communicated with the tank 16, and the control valve 13 is placed in the neutral position. When a signal is input to the solenoid section, pressure oil from the pilot pump 22 is supplied to the hydraulic pilots 13A and 13B in accordance with the amount of the electric signal, and the control valve 13 is switched to the switching position A or B. In addition, 23A, 23B
is a diode for preventing back electromotive force of the electromagnetic proportional valves 21A and 21B.

Next, 24 is the angle θ _B of the boom 4 with respect to the horizontal plane
A boom angle detector 25 is provided on the boom 4 to detect the load of the suspended load 10 due to the boom 4.
A load detector for detecting W _W , the load detector 25
For example, the rope 6 for elevation is attached to the gasoline 5.
The load W _W can be detected from the tension of the Reference numeral 26 denotes an inclination angle detector that detects the inclination angle θ in the longitudinal direction and the inclination angle θ in the horizontal direction of the crane 1 with respect to the horizontal plane. It is configured as a two-axis detector capable of detection, and is installed at a suitable location within the upper revolving body 3, preferably at the center of rotation. Reference numeral 27 denotes a control lever provided in the operator's cab for rotating the upper revolving structure 3; 28 is a control lever detector for detecting the amount of operation of the control lever 27;
For example, a potentiometer that outputs a signal proportional to the operating angle of the operating lever 27 is used.

Furthermore, 29 is an arithmetic device, and the arithmetic device 29, as shown in FIG. , "CPU31"
), a RAM 32 that stores each data described below.
and ROM33 that stores the written program.
It consists of On the other hand, 34 is a preprocessing circuit that performs gain adjustment, zero point adjustment, etc. of the analog signals inputted from the aforementioned detectors 24, 25, 26, and 28, and 35 is an input provided at the next stage of the preprocessing circuit 34. Multiplexer for channels, 36
is the A/
A digital signal from the A/D converter 36 is stored in the RAM 32 via the I/F 30. Furthermore, 37 is a solenoid drive circuit, and the drive circuit 37 controls the electromagnetic proportional valve 29 based on a control signal output from the arithmetic unit 29 via the I/F 30.
It is converted into a valve operation signal to be input to each solenoid section A and 21B.

Next, regarding the arithmetic processing operation of the arithmetic unit 29,
This will be explained with reference to FIG.

First, the crane 1 is stopped on a slope, and the boom angle detector 24, load detector 25,
The detectable signal from the tilt angle detector 26 is stored in the RAM 32 from the I/F 30 via the preprocessing circuit 34, the multiplexer 35, and the A/D converter 36.
Under the control of the ROM 33, the CPU 31 executes step 1.
As shown in the figure, the following equation is calculated to find the turning torque T generated by the inclination.

T=T _C +T _S +T _F +T _W = {k ₁ + (k ₂ + W _W )・B・√1−( _B +) ² }−β …(1) Here, k ₁ = W _C・l _C +W _S・l _S +W _BF・l _BF k ₂ = W _BF +W _F , and T _C : Turning torque by counterweight, T _S : Turning torque by upper rotating structure 3, T _F : Turning torque by hook 9. , T _W : Turning torque due to the suspended load 10, W _W : Weight of the suspended load 10, W _C : Weight of the counterweight, W _S : Weight of the upper rotating structure 3, W _BF : Boom foot equivalent weight, W _BP : Boom point Equivalent weight, B: Length of boom 4, θ _B : Angle of boom 4, α: Angle of inclination in the longitudinal direction of the revolving upper structure 3, β: Angle of inclination in the left-right direction of the revolving upper structure 3, l _C : Center of rotation Length from to the center of gravity of the counterweight, l _S : Length from the center of swing to the center of gravity of the upper rotating body 3, l _BF : Length from the center of swing to the boom foot.

Next, the CPU 31 performs the following steps as shown in the next step 2.
Based on the early swing torque T, a correction amount P _K of the drive pressure of the hydraulic motor 12 necessary to generate the torque T is determined. Since this driving pressure correction amount P _K is expressed as a function proportional to the torque T,
This is done by accessing the table of the function stored in the ROM 33.

On the other hand, when the operator operates the operating lever 27 to rotate the upper revolving structure 3, a detection signal corresponding to the operating amount output from the operating lever detector 28 is transmitted from the I/F 30 to the RAM 3 as described above.
2. Further, the ROM 33 stores a table showing the relationship between the lever stroke of the operating lever 27 and the command pressure P _L as shown in FIG. 4, and the CPU 31 accesses the table and stores it in the RAM 32 as shown in step 3. Command pressure corresponding to the memorized detected value of the operating lever detector 28
P _L is calculated (hereinafter, the calculation for determining the pressure corresponding to the amount of operation of the operating lever 27 as described above will be referred to as "pressure metering conversion").

Next, as shown in step 4, the CPU 31 calculates a new motor drive pressure P _M in step 5 by adding the drive pressure correction amount _PK and the command pressure _PL . That is, the calculation process of P _M = P _K + P _L (2) is performed. In this case, when the upper rotating body 3 turns in the direction up the slope, P _K >0, so the motor drive pressure P _M becomes a value larger than the command pressure P _L , and conversely, in the direction in which the upper rotating body 3 turns down the slope. Since P _K <0 when the vehicle turns, the motor drive pressure P _M has a value smaller than the command pressure P _L .

Further, based on the drive pressure calculated as described above, the CPU 31 performs a calculation to output a control signal corresponding to the drive pressure as shown in step 6, and transmits the control signal from the I/F 30 to the solenoid drive circuit 37. The signal is inputted to the solenoid portions of the electromagnetic proportional valves 21A and 21B via the motor to control the motor drive pressure.

Here, in the valve control open circuit, when the hydraulic motor 12 is an inertial load, the rotation speed of the hydraulic motor 12 is determined by the differential pressure between the inflow pressure and the outflow pressure. In order to control this, it is sufficient to control the supply pressure to the drive circuit 17A or 17B and the return pressure to the return circuit 15 at the switching position A or B of the control valve 13. For this reason, the ROM 33 stores a function table consisting of the motor drive pressure R _M and the output voltage _V as shown in FIG.
The control signal to be outputted to the electromagnetic proportional valves 21A and 21B is calculated by accessing the function table in the table. As a result, the electromagnetic proportional valves 21A and 21B operate the hydraulic pilot 13 of the control valve 13 using the pressure oil proportional to the amount of electric signal based on the control signal as pilot pressure.
A and 13B to set the valve opening at switching position A or B. On the other hand, the control valve 13 has its hydraulic pilots 13A', 13B' connected to drive circuits 17A,
By inputting the pressures P _A and P _B in the hydraulic pilots 17B as the primary pilot pressures, mechanical feedback control is performed such that the pilot pressures corresponding to the control signals input to the hydraulic pilots 13A and 13B match as described above. Do this. As a result, the motor driving pressure P _M and the differential pressure before and after the hydraulic motor 12 (|P _A −P _B |) are made equal, and the hydraulic motor 12
is rotated according to the new motor drive pressure P _M on the slope calculated by the calculation device 29.

The present embodiment is constructed as described above, but first, the operation when the crane 1 is stopped on a slope where it is about to turn to the right and the operating lever 27 is in the neutral position will be described.

At this time, even though the operating lever 27 is in the neutral position, the upper rotating body 3 generates a right-turning torque based on the inclination as shown in equation (1). As a result, the calculation device 29 calculates the turning torque T (1) in step 1, and then calculates the turning torque T in step 2.
Find the drive pressure correction amount P _K required to generate . On the other hand, since the operating lever 27 is in the neutral position, the command pressure P _L is zero even in the pressure metering conversion in step 3. However, even in this case, since the driving pressure correction amount P _K is not zero, the addition of equation (2) is performed in step 4,
In step 5, the motor drive pressure P _M is calculated. Furthermore, in step 6, the arithmetic unit 29 calculates the motor drive pressure from the function table shown in FIG.
A control signal corresponding to _PM is calculated and outputted to the solenoid section of the electromagnetic proportional valve 21A via the solenoid drive circuit 37.

Thus, when the electromagnetic proportional valve 21A is switched in proportion to the amount of the control signal, pressure oil from the pilot pump 22 is supplied to the hydraulic pilot 13A of the control valve 13, and the valve is switched to the switching position A. As a result, pressure oil from the hydraulic pump 11 passes through the drive circuit 14 and the control valve 13 to the drive circuit 17B.
The pressure on the drive circuit 17B side is maintained so as to be apparently zero. As a result, the hydraulic motor 12 performs a pumping action due to the inertial load of the upper rotating body 3, which is an inertial body, and the drive circuit 17B side becomes high pressure by the amount of swing torque based on the inertial load, causing oil pressure to leak from the hydraulic pump 11. However, as mentioned above, the drive circuit 17B
Since the motor drive pressure P _M is equal to the turning torque on the side as well, the differential pressure between each drive circuit 17A and 17B becomes substantially zero. Then, while the operating lever 27 is in the neutral position, the control valve 13 inputs the pressures P _A and P _B of the drive circuits 17A and 17B to their hydraulic pilots 13A' and 13B', and P _B - P _A is applied to the motor. Perform mechanical feedback to match driving pressure P _M. In this way, the revolving upper structure 3 is in the same state as if it were stopped on a flat ground, and it is possible to prevent the revolving upper structure 3 from turning to the right due to inclination.

Next, when the crane 1 is stopped on a slope where it is about to turn right, and the operating lever 27 is switched to the left or right operating position in order to turn the upper rotating structure 3 to the left or right. The operation of the is described below.

At this time as well, the upper revolving body 3 generates a turning torque based on the inclination as shown in equation (1), so the calculation device 29 calculates the turning torque T of equation (1) in step 1, and calculates this turning torque T in step 2. Find the drive pressure correction amount P _K required to generate turning torque. on the other hand,
By stroking the operating lever 27 to the left turning position or right turning position, the operating lever detector 2
8 outputs a signal corresponding to the manipulated variable. As a result, the arithmetic unit 29 performs pressure metering conversion in step 3 based on the characteristics shown in FIG.
Calculate command pressure P _L. Next, in step 4, a computation is performed to add the command pressure P _L and the drive pressure correction amount _PK , which is the correction pressure on the slope, and in step 5, a new motor drive pressure P _M on the slope is determined.
Then, in step 6, the control signal necessary to set the motor drive pressure P _M is calculated, and the electromagnetic proportional valve 2
Output to 1A and 21B.

Thus, first, the operating lever 27 is operated to rotate the upper rotating body 3 to the right, and the electromagnetic proportional valve 21
Assuming that A is switched, pilot pump 2
The pressure oil from 2 is connected to the hydraulic pilot 13 of the control valve 13.
B and is switched to switching position B. As a result, the pressure oil from the hydraulic pump 11 is transferred to the drive circuits 14 and 1.
7A to the hydraulic motor 12 to turn it to the right.

However, first, a case will be considered in which the operating lever 27 is operated to turn to the right while the crane 1 is in a position to turn to the right in the direction of going down a slope. In this case, since the upper rotating body 3 generates a turning torque that causes it to turn to the right due to the inertial load, the correction amount P _K of the motor drive pressure is negative. Therefore, in step 4, P _K +P _L
The motor drive pressure P _M obtained by performing the calculation satisfies P _M < P _L . In this way, the hydraulic motor 12 can be turned to the right from the calculation device 29 based on the motor drive pressure P _M which is smaller than the command pressure P _L of the operating lever 27 by the correction amount P _K , and the upper rotating structure 3 can be flattened. It is possible to turn right while remaining on the ground.

On the other hand, a case will be considered in which the operating lever 27 is operated to turn to the left while the crane 1 is in a position to turn to the right in the direction of going down a slope. In this case, since the drive pressure correction amount P _K is positive, the motor drive pressure P _M >P _L.
Therefore, the arithmetic unit 29 rotates the hydraulic motor 12 to the right based on the motor drive pressure P _M which is greater than the command pressure P _L of the operating lever 27 by the drive pressure correction amount P _K. 3 can be turned left in the same condition as on flat ground.

Furthermore, FIGS. 6 to 9 show a second embodiment of the present invention.

In the first embodiment described above, when calculating the correction amount P _K of the driving pressure based on the turning torque T generated by the tilt in step 2,
The calculation was performed assuming the mechanical efficiency of the hydraulic motor 12 to be 100%. However, the hydraulic motor 12 has a problem in that the mechanical efficiency is not 100% due to frictional resistance, the influence of viscosity due to oil temperature, etc.

That is, the above-mentioned turning torque T and drive pressure correction
P _K is as follows.

P _K = K・T/η _T (3) where K: indicates displacement, a constant determined by reduction ratio, etc., and η _T : indicates mechanical efficiency.

Therefore, in the turning control on a slope described in the first embodiment, by including the mechanical efficiency η _T in the calculation of the drive pressure correction amount P _K , the hydraulic motor drive pressure required by the hydraulic motor 12 and the operating lever 27 can be reduced. The relationship with the manipulated variable can be more closely approximated.

This embodiment has been developed in view of the above-mentioned problems, and will be explained based on the embodiments shown in FIGS. 6 to 9. Note that the same components as those in the first embodiment described above are given the same reference numerals, and their explanations will be omitted.

However, reference numeral 41 denotes a rotation speed detector for detecting the rotation of the hydraulic motor 12, and the rotation speed detector 41 uses, for example, electromagnetic or optical pulse transmitting means.
Reference numeral 42 denotes an oil temperature detector for detecting the temperature of hydraulic oil in the hydraulic circuit, and the oil temperature detector 42 is, for example, the return circuit 1.
It is set in the middle of 5. Furthermore, 43A, 43B
are pressure detectors that detect pressures P _A and P _B corresponding to the inflow side or the outflow side of the hydraulic motor 12, and the pressure detectors 43A and 43B are installed, for example, in the vicinity of the hydraulic motor 12 in the middle of the drive circuits 17A and 17B. provided. Then, in the calculation of the mechanical efficiency η _T described later, it is used to calculate the pressure P=P _A −P _B.
Here, the rotation speed detector 41 is connected to the preprocessing circuit 34 via an F/V converter 44 for converting pulses into voltage, and an oil temperature detector 42 and a pressure detector 4
3A and 43B are also connected to the preprocessing circuit 34, and the detection signals from these are sent to the multiplexer 35 and the A/D
The data is stored in the RAM 32 of the arithmetic unit 29 via the converter 36.

This embodiment is configured as described above, but in step 1, the calculation device 29 calculates the torque T generated by the inclination in the same way as in the first embodiment.
In step 2, a motor drive pressure correction amount P _K is calculated. In this calculation, the mechanical efficiency η _T is expressed by the following formula.

η _T =1−C _f −C _d μn/P …(4) However, C _f , C _d : Friction coefficient, μ : Viscosity, n : Rotational speed of the hydraulic motor 12 , P : Between the inflow and outflow of the hydraulic motor 12 Pressure (P = P _A - P _B ) Also, the viscosity μ is a function of oil temperature as shown in Figure 9.
It is expressed as μ=f(t).

Therefore, since the mechanical efficiency η _T is expressed as a function including the rotation speed n of the hydraulic motor 12, the pressure P, and the oil temperature t, in step 2, the arithmetic unit 29
Store the table of μ=f(t) in the ROM33,
The CRU31 uses the rotational speed η, pressure P, and oil temperature t stored in the RAM32, and μ=f in the ROM33.
While accessing the table showing (t), calculations of equations (3) and (4) are performed to obtain the driving pressure correction amount P _K including the mechanical efficiency η _T .

Furthermore, the arithmetic processing in steps 3 to 6 is performed, and control signals are output to the solenoid portions of the electromagnetic proportional valves 21A and 21B to control the rotation of the hydraulic motor 12. As a result, the influence of viscosity due to oil temperature,
Turning control can be performed in consideration of frictional resistance.

The swing control device for a hydraulic crane according to the present invention, as described in detail above, can perform the same swing operation even on a slope as on a flat ground, and therefore has the following effects.

Even if the swing control lever is held in the neutral position with the parking brake inactive, the upper revolving structure can be held stationary, making it possible to carry out swinging turns on slopes, and to lift suspended loads. It is possible to ensure the safety of ground cutting during lifting, and also to prevent the upper revolving structure from running away.

Since the operating amount of the operating lever can be the same when turning down a slope and when turning up a slope, even an unskilled operator can easily perform turning operations on a slope. It is possible to improve operability and reduce operator fatigue.

Since the swing operation is easy, it is possible to prevent the danger of hanging loads from swinging out and improve the safety of work on slopes.

Since it is possible to perform control that takes into account the influence of oil temperature during turning operations on slopes, it is possible to maintain acceleration performance similar to that on flat lands.

Even in the case where the lower traveling body is a floating crane capable of navigating underwater, it is possible to perform a turning operation that takes into account the rocking caused by waves (the inclination of the upper rotating body).

[Brief explanation of the drawing]

1 to 4 show a first embodiment of the present invention, FIG. 1 is an overall configuration diagram thereof, FIG. 2 is a circuit configuration diagram consisting of each detector and an arithmetic unit, and FIG. 3 is an arithmetic operation diagram. An explanatory diagram explaining the processing in the device, FIG. 4 is a diagram showing the relationship between the operating lever stroke and the command pressure,
Fig. 5 is a diagram showing the relationship between motor drive pressure and output voltage, Figs. 6 to 9 show a second embodiment of the present invention, Fig. 6 is its overall configuration diagram, and Fig. 7 shows each FIG. 8 is an explanatory diagram illustrating processing in the arithmetic device; FIG. 9 is a diagram showing the relationship between oil temperature and viscosity. 1... Crane, 2... Lower traveling body, 3... Upper revolving body, 4... Boom, 10... Hanging load, 11...
... Hydraulic pump, 12 ... Hydraulic motor, 13 ... Control valve, 14, 17A, 17B ... Drive circuit, 15
...Return circuit, 21A, 21B...Electro-hydraulic conversion valve (electromagnetic proportional valve), 24...Boom angle detector,
25...Load detector, 26...Inclination angle detector, 2
7... Operating lever, 28... Operating lever detector,
29...Arithmetic unit, 34...Preprocessing circuit, 35...
...Multiplexer, 36...A/D converter, 41
...Rotation speed detector, 42...Oil temperature detector, 43
A, 43B...Pressure detector.

Claims (1)

[Claims] 1. A crane in which an upper revolving body is rotatably provided on a lower traveling body and a boom is attached to the upper revolving body, a hydraulic pump, a hydraulic motor that swings and drives the upper revolving body, and a transmission from the hydraulic pump to the hydraulic motor. In order to control the flow direction and driving pressure of the pressure oil, the hydraulic pump and the hydraulic motor are connected to a valve control open circuit via the control valve. In the hydraulic crane that is connected to the an inclination angle detector for detecting an angle of inclination; an operating lever detector for detecting an operating amount of an operating lever for rotating the upper rotating body; and an electro-hydraulic conversion valve for supplying a pilot pressure corresponding to a signal amount to the control valve. and an arithmetic device that receives signals from each of the detectors and outputs a control signal to the electro-hydraulic conversion valve, and the arithmetic device includes the boom angle detector, the load detector, and the inclination angle detector. By inputting each detection signal from the operating lever detector, calculation is performed to obtain a correction amount for the drive pressure of the hydraulic motor corresponding to the torque generated by the tilting of the crane, and then based on the detection signal from the operating lever detector. A calculation is performed to obtain a new motor drive pressure at the slope value by adding the command pressure of the operating lever and the correction amount of the drive pressure, and further, in order to operate the control valve, the new motor drive pressure is added. A swing control device for a hydraulic crane, characterized in that it is configured to perform calculations to output a corresponding control signal to the electro-hydraulic conversion valve.