JPH0314756B2 - - Google Patents

Description

DETAILED DESCRIPTION OF THE INVENTION The present invention automatically corrects the driving pressure of the hydraulic motor by the amount of turning moment generated by the slope when turning a hydraulic crane on a slope, so that the same turning operation can be achieved even 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 an upper revolving body is rotatably provided on a lower traveling body and a boom is attached to the upper revolving body, and a bleed-off circuit for driving the upper revolving body to rotate. The bleed-off 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 operating amount of the operating lever, and the pilot valve. The hydraulic pump is comprised of a control valve that controls the flow direction of pressure oil from the hydraulic pump to the hydraulic motor and the driving pressure using pilot pressure, and the hydraulic pump and the hydraulic motor are connected via the control valve. As the control valve, for example, a center bypass type three-position directional switching valve is used.

In this way, the crane upper revolving body control circuit that employs a bleed-off circuit is a bleed-off control, in which the secondary pressure of the pilot valve is controlled by the operating lever, and the control valve is controlled by the secondary pressure. do. Therefore, if the drive pressure to the hydraulic motor is controlled by changing the secondary pressure of the pilot valve using the operating lever and adjusting the opening degree of the control valve,
The rotation speed of the hydraulic motor can be changed. In addition, when the operating lever is in the neutral position, the pilot valve and control valve are also in the neutral position, the inflow and outflow sides of the hydraulic motor are both connected to the tank and are in a tank pressure state, and the upper rotating body is not affected by inertial force or external force. It is possible to turn even when it is tilted, so-called "driving operation", and on the other hand, it can lift suspended loads from the ground.
It has the characteristic that the positioning of the revolving superstructure can be automatically performed at the time of so-called "ground cutting". 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 on sloped land for work. In this case, in a hydraulic crane that employs the swing bleed-off 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. When the brake is inactive, a swinging moment is generated in the upper revolving structure due to the loads of the upper revolving structure, boom, suspended load, etc., and the upper revolving structure is directed downward on the slope against the operator's will. The disadvantage is that it turns around.

In addition, in the turning bleed-off circuit, the drive pressure of the hydraulic motor is controlled by the operating lever, but if we compare the times when turning right and turning left,
The load torque of the hydraulic motor differs by "turning moment x 2" when turning up a slope and when turning down a slope. As a result,
The operability of the control lever varies widely and is very difficult to operate, which not only increases the fatigue of the operator but also has the disadvantage that there is a high possibility that dangerous conditions such as load swinging may occur.

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 a flat platform, when the control lever is in the neutral position, it is possible to maintain the upper rotating structure in neutral, thereby improving the safety of drifting operation on slopes and ground cutting. This hydraulic crane is designed to ensure the same amount of operation of the control lever when going up and down slopes, making it easy for the operator to operate, and preventing 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 operation amount of the operating lever that performs the rotation operation of the upper rotating structure; and a pressure detector that detects the inflow pressure and outflow pressure of the hydraulic motor, respectively. an electro-hydraulic converter valve that supplies 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 converter valve. The calculation device calculates the drive pressure of the hydraulic motor corresponding to the torque generated by the tilting of the crane by inputting each detection signal from the boom angle detector, load detector, and tilt angle detector. Perform calculations to find the correction amount,
Next, a calculation is performed to obtain a new motor drive pressure on a slope by adding the control lever command pressure based on the detection signal from the control lever detector and the correction amount of the drive pressure. The present invention is configured to perform calculations to output a control signal to match the new motor driving pressure to the electro-hydraulic conversion valve while inputting a pressure signal from an inflow and outflow side of the hydraulic motor from a pressure detector. .

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

1 to 6 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 that is rotatably provided on the lower traveling body 2, and an upper rotating body 3 that is installed on the upper rotating body 3 so that it can be tilted down. It is roughly composed of boom 4. The boom 4 can be depressed downward via a downward restraining 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 bleed-off 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 hydraulic pump that drives the upper revolving body 3 as a load. A hydraulic motor 13 rotates 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 three-position directional switching valve having switching positions (a) and (b). 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
When the is in the neutral position, the hydraulic pump 11 and the drive circuit 14 are connected to the tank 16 via the unload circuit 18, and the drive circuits 17A and 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.
is in communication 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, and 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 bleed-off circuit constructed as described above is essentially the same as the conventional technology.

Further, 21A and 21B apply 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 the hydraulic pilot 1 of the control valve 13.
As the electro-hydraulic conversion valves 21A and 21B, for example, an electromagnetic proportional valve that generates a hydraulic pressure proportional to the magnitude of the electric signal amount is used (hereinafter referred to as The electro-hydraulic conversion valves 21A, 21B are called "electromagnetic proportional valves 21A, 2".
1B”). And the electromagnetic proportional valve 21A, 2
1B has its inflow side connected to the pilot pump 22, and its outflow side connected to each hydraulic pilot 13A, 13B of the control valve 13, and communicates the hydraulic pilot 13A, 13B with the tank 16 when no signal is input to the solenoid section. The control valve 13 is held in the neutral position, and a signal is input to the solenoid section, so that the pressure oil from the pilot pump 22 is transferred to the hydraulic pilot 13 according to the amount of the electric signal.
A and 13B, and switch the control valve 13 to the switching position (a) or (b). Note that 23A and 23B are diodes 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 downward restraining rope 6 is attached to the gantry 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 an operating lever provided in the operator's cab for rotating the upper revolving structure 3; 28 indicates an operating lever detector for detecting the amount of operation of the operating lever 27;
For example, a potentiometer or the like that outputs a signal proportional to the operating angle of the operating lever 27 is used.

On the other hand, 29A and 29B are pressure detectors that detect pressures P _A and P _B corresponding to the inflow pressure or outflow pressure of the hydraulic motor 12.
B is provided, for example, in the vicinity of the hydraulic motor 12 in the middle of the drive circuits 17A, 17B.

Furthermore, 30 is an arithmetic device, and the arithmetic device 30
As shown in FIG.
32''), and stores each data described below.
Stores RAM33 and written programs
It consists of ROM34. On the other hand, 35 is each of the aforementioned detectors 24, 25, 26, 28 and 29.
A preprocessing circuit that performs gain adjustment, zero point adjustment, etc. of the analog signal input from A and 29B; 36 is an input channel multiplexer provided at the next stage of the preprocessing circuit 35; 37 is the next stage of the multiplexer 36; The A/D converter installed in the
The digital signal from the D converter 37 is stored in the RAM 33 via the I/F 31. Furthermore, 38 is a solenoid drive circuit, and the drive circuit 38 is an I/F
Based on the control signal outputted from the arithmetic unit 30 via the controller 31, the control signal is converted into a valve operation signal to be input to each solenoid section of the electromagnetic proportional valves 21A and 21B.

Next, regarding the arithmetic processing operation of the arithmetic device 30,
This will be explained with reference to FIG.

First, the crane 1 is stopped on a slope, and the boom detectors 24, load detectors 25,
Each detection signal from the tilt angle detector 26 is stored in the RAM 33 from the I/F 31 via the preprocessing circuit 35, multiplexer 36, and A/D converter 37.
Under the control of the ROM 34, the CPU 32 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 }-...(1) Here, k ₁ = W _C l _C + W _S・l _S + W _BF・l _BF k ₂ = W _BP + W _F , and T _C : Turning by counterweight Torque, T _S : Turning torque by the upper rotating structure 3, T _F : Turning torque by the hook 9, T _W : Turning torque by the suspended load 10, W _W : Weight of the suspended load 10, W _C : Weight of the counterweight, W _S : Weight of rotating upper structure 3, W _BF : Equivalent weight of boom foot, W _BP : Equivalent weight of boom point B: Length of boom 4 θ _B : Angle of boom 4 α: Angle of inclination of upper rotating structure 3 in the longitudinal direction, β: Lateral inclination angle of the upper rotating body 3, l _C : Length from the center of rotation to the center of gravity of the counterweight, l _S : Length from the center of rotation to the center of gravity of the upper rotating body 3, l _BF : Center of rotation Length from to boom foot,
represents.

Next, the CPU 32 performs the following steps as shown in the next step 2.
Based on the turning torque T, a correction amount P _K of the driving 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 34.

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 31 to the RAM 3 as described above.
3 is stored. Further, the ROM 34 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 32 accesses the table and stores it in the RAM 33 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 32 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 .

Here, in the bleed-off circuit, when the hydraulic motor 12 is an inertial load, the hydraulic motor 1
2 is determined by the differential pressure between the inflow pressure P _A and the outflow pressure P _B , so the inflow pressure
In order to control P _A , the switching position of the control valve 13 must be
Drive circuit 17A or 17B in (a) or (b)
What is necessary is just to control the supply pressure to and the return pressure to the return circuit 15. Therefore, in the next step 6, the CPU 32 uses the previously calculated motor drive pressure P _M and
From the detected pressures P _A and P _B stored in the RAM 33, a calculation is performed to find the deviation P as follows: P _M - | P _A - P _B | = P (3). Furthermore, in the next step 7, the control signal P _p is calculated as P _p = P _M + P = (4), and the control signal P _O is
1 of the program from the solenoid drive circuit 38 to the solenoids of the electromagnetic proportional valves 21A and 21B.
Output every cycle. In specific processing
The ROM34 contains motor drive pressure as shown in Figure 5.
A function table of V _M = f (P _M ) consisting of P _M and output voltage V _M is stored, and the deviation P〓 and output voltage
A function table consisting of V〓=f(P〓) is stored, and the CPU 32 performs the calculation of the following equation (4)' while accessing the table, V _O = V _M + V〓 . . . (4)' A control signal V _O corresponding to the electrical signal amount obtained thereby is output for each cycle of the program. As a result, through feedback control for each cycle of the program, the pressure is damped and oscillated toward the motor drive pressure P _M while approaching P=0.
That is, pressure control is performed such that the motor drive pressure P _M and the differential pressure across the hydraulic motor 12 (|P _A −P _B ) match.

In addition, in the function shown in FIG. 6, the output voltage is kept constant when the deviation exceeds a predetermined deviation ± _P〓O , thereby preventing the occurrence of extreme pressure fluctuations in one program cycle. Alternatively, the pressure of the hydraulic motor 12 may be controlled by directly outputting a control signal corresponding to the deviation P obtained by the calculation in step 5. In this case, motor drive pressure P _M
Pressure control will be performed to asymptotically approach P = 0, but the control time will be slightly longer than damped oscillatory control based on equation (4).

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 30 calculates the turning torque T (1) in step 1, and calculates the turning torque T in step 2.
Find the driving 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, the arithmetic unit 30 calculates equation (3) in step 6, and then calculates equation (4) in step 7.
The control signal P _O is obtained by calculating the formula. In this way, the CPU 32 performs feedback control so that the difference between the motor drive pressure P _M and the detected pressures P _A and P _B input from the pressure detectors 29 and 29B coincides with each other every cycle of the program, and also outputs the control signal.
P _O (specifically, an electrical control signal V _O corresponding to the control signal P _O as shown in equation (4)') is output. This control signal is input to the solenoid section of the electromagnetic proportional valve 21A via the solenoid drive circuit 38.

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 that the pressure on the drive circuit 17B side is 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 attempts to reach a high pressure by the amount of turning torque based on the inertial load, and attempts to turn right. However, as mentioned above, since the drive circuit 17B side also supplies the motor drive pressure P _M corresponding to the swing torque to the hydraulic motor 12, the torque generated in the hydraulic motor 12 due to the differential pressure between each drive circuit 17A and 17B is Balances the torque generated by the tilt. Then, while the operation lever 27 is in the neutral position, the calculation device 30 inputs the detected pressures P _A and P _B from the pressure detectors 29A and 29B,
A control signal such that P _B - P _A matches the motor drive pressure P _M is output to the electromagnetic proportional valve 21A. 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 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 to the right from a state where the crane 1 is stopped on a slope where it is about to turn to the 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 30 calculates the turning torque T of equation (1) in step 1, and calculates this turning torque T in step 2. The driving pressure correction amount P _K required to generate the turning torque T is determined. 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 this manipulated variable. As a result, the arithmetic unit 30 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 deviation P is calculated, and in the next step 7, a calculation is performed to obtain the control signal _PO , and the control signal is output to the electromagnetic proportional valves 21A 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 the switching position (B). Thereby, the pressure oil from the hydraulic pump 11 is transferred to the drive circuit 14,
It is supplied to the hydraulic motor 12 via 17A 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 rotated to the right from the calculation device 30 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 body 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 calculation device 30 rotates the upper rotating structure by turning the hydraulic motor 12 to the right based on the motor drive pressure P _M which is larger 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.

Next, FIG. 7 shows a second embodiment of the present invention,
The feature of this embodiment is that the electro-hydraulic conversion valve is replaced with the electromagnetic proportional valves 21A and 21B in the first embodiment, and
The reason is that it is composed of several solenoid valves.

That is, in FIG. 7, the same components as in the first embodiment described above are given the same reference numerals and their explanations will be omitted. The solenoid valves 41 and 44 are normally closed, and the solenoid valves 42 and 43 are normally open.
Solenoid valves 41, 44 and 43, 54 are connected in series between the pilot pump 22 and the tank 16, and the hydraulic pilots 13A, 13B of the control valve 13 are connected between the solenoid valves 41 and 42, 43 and 44, respectively.

Since the present embodiment is configured in this way, the control signal can be controlled by outputting the control signal from the arithmetic unit 30 to the solenoids 41A and 42A and by supplying the pressure oil from the pilot pump 22 to the hydraulic pilot 13A of the control 13. The hydraulic pump 11 supplies driving pressure in a direction to turn the hydraulic motor 12 to the right by an amount corresponding to the signal amount. Conversely, by outputting a control signal from the arithmetic device 30 to the solenoids 43A and 44A, the hydraulic pump 11 supplies driving pressure in a direction to turn the hydraulic motor 12 to the right in accordance with the signal amount.

Furthermore, FIGS. 8 to 11 show the third embodiment of the present invention.
An example is shown below.

In the first and second embodiments described above, the turning torque T generated by the tilt in step 2 is
When calculating the driving pressure correction amount P _K based on
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 (5) 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 by focusing on the above-mentioned problems, and will be explained based on the embodiments shown in FIGS. 8 to 11. Note that the same components as in the first embodiment described above are denoted by the same reference numerals, and the explanation thereof will be omitted.

However, 51 is a rotation speed detector for detecting the rotation of the hydraulic motor 12, and the rotation speed detector 51 uses, for example, electromagnetic or optical pulse transmitting means.
Reference numeral 52 denotes an oil temperature detector that detects the temperature of hydraulic oil in the hydraulic circuit, and the oil temperature detector 52 is, for example, the return circuit 1.
It is set in the middle of 5. And the rotation speed detector 5
1 is connected to the preprocessing circuit 35 via the F/V converter 53 for converting pulses into voltage, and the oil temperature detector 52 is also connected to the preprocessing circuit 35, and the detection signals from these are sent to the multiplexer 36, The data is stored in the RAM 33 of the arithmetic unit 30 via the A/D converter 37.

This embodiment is configured as described above, but in step 1, the calculation device 30 calculates the torque T generated by the inclination 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 ...(6) However, C _f , C _d : coefficient of friction, μ : viscosity, n : rotational speed of hydraulic motor 12 , P : introduction to outflow of hydraulic motor 12 pressure.

Further, the viscosity μ is expressed as a function of oil temperature, μ=f(t), as shown in FIG.

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 30
Store the table of μ=f(t) in the ROM34, and
32 calculates equations (5) and (6) while accessing the rotation speed n, pressure P, and oil temperature t stored in the RAM 33 and the table showing μ=f(t) in the ROM 34. Find the driving pressure P _K including the efficiency η _T.

Furthermore, the arithmetic processing in steps 3 to 7 is performed, and a control signal is output to the solenoid sections 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.

Furthermore, FIG. 12 shows a fourth embodiment of the present invention.

The feature of this embodiment is that it shows a modification of steps 6 and 7 in the first embodiment described above.
In Figure 2, 61 is a subtractor that calculates the circuit pressure P by subtracting the detected pressures P _A and P _B from the pressure detectors 29A and 29B, and 62 is the circuit pressure P obtained by the subtractor 61 that is used as the output voltage. It is a hydraulic pressure to voltage converter that converts to V _p . Further, 63 is a hydraulic pressure-voltage converter that converts the motor drive pressure P _M calculated in step 5 in the first embodiment into an output voltage V _M. 6
4 is a subtracter, and the subtracter 64 is based on the input voltages V _p and V _M from the respective hydraulic pressure-voltage converters 62 and 63,
The deviation ε is obtained by subtracting ε=|V _M −V _p |. 65A and 65B are function generators, one function generator 65A generates an output voltage V corresponding to the deviation ε when ε>0, and the other function generator 65B generates an output voltage V〓 corresponding to the deviation ε when ε<0. This generates an output voltage V〓 corresponding to the deviation ε. Note that the function generators 65A and 65B correspond to the function table shown in FIG. Furthermore, 66A, 66B
indicates an adder, one adder 66A combines the output voltage V _M from the hydraulic pressure-voltage converter 63 and the function generator 6.
By adding the output voltage V〓 from 5A as V _O =V _M +V〓, the control signal V _O is applied to the electromagnetic proportional valve 2.
It outputs to 1A. Further, the other adder 66B outputs the output voltage from the hydraulic pressure-voltage converter 63.
V _M and the output voltage V from the function generator 65B, V _O
By adding as =V _M +V〓, the control signal
This outputs V _O to the electromagnetic proportional valve 21B.

The present embodiment is constructed as described above, but the subtracter 64 corresponds to the operation in step 6 in the first embodiment, and the adders 66A and 66B similarly correspond to the operation in step 7. These perform calculations at predetermined time intervals based on clock signals,
Pressure control is performed by controlling the electromagnetic proportional valves 21A and 21B.

Note that also in this embodiment, the adders 66A, 6
6B is omitted, and the output voltage V from the function generators 65A, 65B is used as a control signal to control the electromagnetic proportional valves 21A,
It may be output to 21B. In this case, pressure control is performed such that the pressure asymptotically approaches the motor drive pressure P _M so that the deviation ε=0.

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 6 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 device, 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, FIG. 6 is a diagram showing the relationship between deviation and output voltage, and FIG. 7 is an overall configuration diagram showing the second embodiment of the present invention. 8 to 11 show a third embodiment of the present invention, in which FIG. 8 is an overall configuration diagram thereof, FIG. 9 is a circuit configuration diagram consisting of each detector and an arithmetic unit, and FIG.
Figure 0 is an explanatory diagram explaining the processing in the arithmetic unit, the first
FIG. 1 is a diagram showing the relationship between oil temperature and viscosity, and FIG. 12 is a circuit configuration diagram showing a fourth embodiment of the present invention. 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...Pressure detector, 30...Calculation device, 35...
...Preprocessing circuit, 36...Multiplexer, 37...
...A/D converter, 51... Rotation speed detector, 52...
...Oil temperature 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. and a control valve for controlling the flow direction and driving pressure of pressure oil, and the hydraulic crane is configured to connect the hydraulic pump and the hydraulic motor by a bleed-off circuit via the control valve. a boom angle detector that detects the load of the load suspended by the boom; a tilt angle detector that detects the tilt angle of the crane in the longitudinal direction and the left-right direction; and the rotation of the upper rotating structure. an operating lever detector that detects the operating amount of the operating lever that performs the operation, a pressure detector that detects the inflow pressure and outflow pressure of the hydraulic motor, and supplies pilot pressure corresponding to the signal amount to the control valve. Signals from the electro-hydraulic conversion valve and each of the detectors are input,
and a calculation device that outputs a control signal to the electro-hydraulic conversion valve, and the calculation device controls the crane by receiving each detection signal from the boom angle detector, load detector, and inclination angle detector. Calculation is performed to determine the correction amount of the drive pressure of the hydraulic motor corresponding to the torque generated by the tilt, and then the command pressure of the control lever based on the detection signal from the control lever detector and the correction amount of the drive pressure are calculated. A calculation is performed to obtain a new motor drive pressure on a slope by adding the above, and the pressure signals on the inflow and outflow sides of the hydraulic motor are inputted from each of the pressure detectors to match the new motor drive pressure. 1. A swing control device for a hydraulic crane, characterized in that the swing control device for a hydraulic crane is configured to perform calculations for outputting a control signal to the electro-hydraulic conversion valve.