JP3445167B2 - Hydraulic construction machine hydraulic pump torque control device - Google Patents

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a torque control device for a hydraulic pump of a hydraulic construction machine, and more particularly, it includes a diesel engine as a prime mover, and a hydraulic actuator is driven by pressure oil discharged from a hydraulic pump rotationally driven by the engine. The present invention relates to a torque control device for a hydraulic pump of a hydraulic construction machine such as a hydraulic excavator that drives and performs necessary work.

[0002]

2. Description of the Related Art Generally, a hydraulic construction machine such as a hydraulic excavator is equipped with a diesel engine as a prime mover, and at least one variable displacement type hydraulic pump is rotationally driven by the engine, and hydraulic oil is discharged by pressure oil discharged from the hydraulic pump. The actuator is being driven and the necessary work is being done. The diesel engine is provided with an input means for instructing a target rotation speed such as an accelerator lever, the fuel injection amount is controlled according to the target rotation speed, and the rotation speed is controlled.

Regarding control of an engine and a hydraulic pump in such a hydraulic construction machine, Japanese Patent Publication No. 62-8618 proposes a control method entitled "Control method of drive system including internal combustion engine and hydraulic pump". ing. This control method obtains the difference (rotational speed deviation) between the target rotational speed and the actual engine rotational speed from the rotational speed sensor, and uses this rotational speed deviation to control the input torque of the hydraulic pump. It is an example of control.

The purpose of this control is to reduce the load torque (input torque) of the hydraulic pump, prevent engine stop, and reduce engine output when the actual engine speed detected with respect to the target speed decreases. It is to use effectively.

[0005]

By the way, the reduction in engine output changes depending on the environment surrounding the engine.
For example, if the place of use is high, the engine output torque decreases due to the decrease in atmospheric pressure.

When the engine load is light, a point on the regulation of the fuel injection device (governor mechanism) becomes a matching point between the engine load and the output torque, and the engine speed is the target rotation speed regardless of the decrease in the engine output due to changes in the environment. It is a little higher than the number on the regulation characteristic line of the governor mechanism.

When the engine load increases, the output torque with respect to the target rotational speed determined by the engine output torque characteristic peculiar to the engine becomes a matching point with the engine load,
At this matching point, when the engine output decreases due to changes in the environment, the speed sensing control decreases the absorption torque of the hydraulic pump according to the decrease in the engine speed, and the absorption torque of the hydraulic pump and the output torque of the engine become equal. Match at the point where it became.

Therefore, in the above-mentioned conventional technique, when the engine load increases, if the engine output decreases due to a change in the environment, the engine speed greatly decreases as the engine load changes from a light load to a high load. For example, if the hydraulic construction machine is a hydraulic excavator and you are going to perform excavation work at a high altitude with this hydraulic excavator, the engine speed will be slightly higher than the target speed input by the operator when the bucket is empty, When the earth and sand are excavated, the engine speed decreases significantly.

As a result, noise and vibration of the vehicle body due to the engine speed change, and the operator feels tired.

On the other hand, in a hydraulic construction machine such as a hydraulic excavator, when the controller is mounted, the mounting space of the controller is limited and the processing capacity (capacity) of the controller is also limited accordingly. For this reason, when a program is installed in the controller, it is necessary to perform processing as fast as possible with the limited processing capacity of the controller. In particular, when a new function is added to the controller, it is necessary to enable fast processing even if there is another processing.

The object of the present invention is to reduce the decrease in the rotational speed of the prime mover under a high load even when the output of the prime mover is reduced due to a change in the environment, and to perform processing as fast as possible with the limited processing capacity of the controller. A torque control device for a hydraulic pump of a hydraulic construction machine.

[0012]

(1) In order to achieve the above object, the present invention provides a prime mover, a variable displacement hydraulic pump driven by the prime mover, and input means for instructing a target rotational speed of the prime mover. A first detection means for detecting an actual rotation speed of the prime mover, and a speed sensing control means for calculating a deviation between the target rotation speed and the actual rotation speed and controlling a maximum absorption torque of the hydraulic pump based on the deviation. In a torque control device for a hydraulic pump of a hydraulic construction machine including: a second detection unit that detects a plurality of state quantities related to the environment of the prime mover; and an environment of the prime mover based on a detection value of the second detection unit. For each state quantity related to, the individual calculation means for calculating the influence quantity of the output change corresponding to the detected value of the state quantity at that time from the relationship between the predetermined state quantity and the influence quantity of the output change of the prime mover, Of the torque correction means for correcting the maximum absorption torque of the oil <br/> pressure pump controlled by the speed sensing control means according to the calculated value of the individual operating means, provided in the individual operating means, said second detector And an input control means for inputting the detection value of the means at a predetermined time interval for each state quantity related to the environment of the prime mover.

Here, the state quantity related to the environment of the prime mover detected by the second detecting means includes cooling water temperature, intake air temperature, engine oil temperature, exhaust temperature, atmospheric pressure, intake pressure, exhaust pressure and the like.

In this way, the second detecting means detects the state quantity related to the environment of the prime mover, and the torque correcting means corrects the maximum absorption torque of the hydraulic pump based on the detected value, whereby the output of the prime mover due to a change in the environment. The maximum absorption torque of the hydraulic pump can be reduced in advance by the amount of decrease, and even if the output of the prime mover decreases due to environmental changes, the prime mover rotation speed at the maximum torque matching point does not decrease significantly, and the decrease in the prime mover rotation speed is small. Good workability can be secured.

Further, the input control means inputs the detection value of the second detection means at a predetermined time interval for each state quantity related to the environment of the prime mover, as compared with the case where the detection value is always input. , The amount of processing for inputting the detected value is reduced.
Therefore, even if the processing capacity of the controller is limited,
Can perform relatively fast processing.

(2) In the above item (1), preferably
The input control means is means for loading the detection value of the second detection means into the memory at the predetermined time interval, and the individual computing means uses the detection value loaded in the memory to detect the change in the output. Calculate the amount of influence.

As a result, as compared with the case where the detected value is constantly stored in the memory, the amount of the detected value stored in the memory is reduced, and the processing amount relating to the input of the detected value is reduced.

(3) Further, in the above (1), preferably, the input control means is means for taking the detection value of the second detection means into the individual calculation means at the predetermined time interval, The individual calculation means has means for calculating the influence amount of the output change by using the detected value acquired at the predetermined time interval and storing the calculated value in the memory.

As a result, as compared with the case where the detected value is always stored in the memory and the influence amount of the output change is constantly calculated using the fetched detected value, the amount of the detection value stored in the memory and the calculation amount of the influence amount of the output change are calculated. Is reduced and faster processing can be performed.

(4) Further, in the above (1), preferably, the input control means sets the time interval to be long for a detected value of a state quantity that changes little during the operation of the hydraulic construction machine, The time interval is set short for the detected value of the state quantity that greatly changes during the operation of the hydraulic construction machine.

As described above, by setting a long time interval and inputting the detected value for the detected value of the state quantity in which the change during the operation of the hydraulic construction machine is small, the detected value is detected. The accuracy of the maximum absorption torque correction by the torque correction means is set by setting the time interval short and inputting the detected value for the state quantity that changes greatly during the work of the hydraulic construction machine as the input processing amount of the value decreases. Is maintained.

(5) Further, in the above-mentioned (1), preferably, the individual calculating means has a relationship between the state quantity and the influence quantity of the output change of the prime mover for each state quantity related to the environment of the prime mover. The relationship between the state quantity and the correction gain of the output change of the prime mover is stored in advance, and from this relationship, the correction gain of the output change corresponding to the detected value of the state quantity at that time is calculated as the influence quantity of the output change.

Thus, the individual calculation means calculates the influence amount of the output change for each state quantity related to the environment of the prime mover as a correction gain, and the torque correction means can correct the maximum absorption torque of the hydraulic pump using the correction gain. .

(6) Further, in the above (1), preferably, the torque correction means obtains a torque correction value of the hydraulic pump according to a calculation value of the individual calculation means, and based on this torque correction value. The maximum absorption torque of the hydraulic pump is corrected.

As described above, the maximum correction torque of the hydraulic pump can be corrected by obtaining the output decrease of the prime mover due to the change of environment as the torque correction value by the torque correction means.

(7) In the above (1), the torque correction means obtains a rotation speed correction value of the prime mover according to the calculation value of the individual calculation means, and based on this rotation speed correction value, the hydraulic pump The maximum absorption torque may be corrected.

As described above, the maximum absorption torque of the hydraulic pump can be corrected even if the torque correction means calculates the output reduction of the prime mover due to environmental changes as the rotation speed correction value.

(8) Further, in the above (1), preferably, the speed sensing control means calculates the pump base torque according to the target rotation speed, and at the same time, the speed sensing torque deviation according to the rotation speed deviation. And a first means for calculating the target maximum absorption torque of the hydraulic pump by adding the speed sensing torque deviation to the pump base torque, and limiting the maximum displacement of the hydraulic pump based on the target maximum absorption torque. And a second means, wherein the torque correction means calculates a torque correction value for the target maximum absorption torque according to the calculation value of the individual calculation means, and the pump base torque is calculated by the first means. A fourth procedure for correcting the target maximum absorption torque by subtracting the torque correction value when adding the speed sensing torque deviation. With the door.

In this way, the output reduction amount of the prime mover due to the environmental change is obtained as a torque correction value, and this torque correction value is subtracted from the pump base torque to correct the target maximum absorption torque, whereby the maximum absorption torque of the hydraulic pump is calculated. Can be corrected.

(9) In the above item (1), the speed sensing control means calculates the pump base torque according to the target rotation speed, and subtracts the target rotation speed from the actual rotation speed to obtain the rotation speed deviation. First means for correcting the pump base torque in accordance with the rotational speed deviation to obtain the target maximum absorption torque of the hydraulic pump, and limiting control of the maximum capacity of the hydraulic pump based on the target maximum absorption torque. A second means, wherein the torque correction means calculates a rotation speed correction value for the target rotation speed based on the calculated value of the individual calculation means; and the first means calculates an actual rotation speed from the actual rotation speed. The rotation speed correction value may be further reduced when the target rotation speed is reduced.

In this way, the target maximum absorption torque of the hydraulic pump can be corrected also by obtaining the output reduction of the prime mover due to environmental changes as the rotation speed correction value and further subtracting the rotation speed correction value from the actual rotation speed. it can.

[0032]

BEST MODE FOR CARRYING OUT THE INVENTION Embodiments of the present invention will be described below with reference to the drawings. The following embodiment is a case where the present invention is applied to an engine / pump control device for a hydraulic excavator.

First, a first embodiment of the present invention will be described with reference to FIGS.

In FIG. 1, reference numerals 1 and 2 denote, for example, swash plate type variable displacement hydraulic pumps. The discharge passages 3 and 4 of the hydraulic pumps 1 and 2 are connected with a valve device 5 shown in FIG. Pressure oil is sent to the plurality of actuators 50 to 56 via the device 5 to drive these actuators.

Reference numeral 9 denotes a fixed displacement type pilot pump, and a discharge passage 9a of the pilot pump 9 is connected to a pilot relief valve 9b for keeping the discharge pressure of the pilot pump 9 at a constant pressure.

Hydraulic pumps 1, 2 and pilot pump 9
Is connected to the output shaft 11 of the prime mover 10 and is rotationally driven by the prime mover 10. Reference numeral 12 is a cooling fan, and 13 is a heat exchanger.

Details of the valve device 5 will be described.

In FIG. 2, the valve device 5 is a flow control valve 5
a to 5d and flow control valves 5e to 5i, and the flow control valves 5a to 5d are the discharge passage 3 of the hydraulic pump 1.
Is located on the center bypass line 5j connected to, and the flow rate control valves 5e to 5i are located on the center bypass line 5k connected to the discharge passage 4 of the hydraulic pump 2. The discharge passages 3 and 4 are provided with a main relief valve 5m that determines the maximum discharge pressure of the hydraulic pumps 1 and 2.

Flow control valves 5a-5d and flow control valve 5e
5i is a center bypass type, and the hydraulic pump 1,
The pressure oil discharged from No. 2 is supplied to the corresponding one of the actuators 50 to 56 by these flow rate control valves. The actuator 50 is a hydraulic motor for traveling right (right traveling motor), the actuator 51 is a hydraulic cylinder for bucket (bucket cylinder), the actuator 52 is a hydraulic cylinder for boom (boom cylinder), the actuator 5
3 is a turning hydraulic motor (turning motor), actuator 54 is an arm hydraulic cylinder (arm cylinder),
The actuator 55 is a spare hydraulic cylinder, the actuator 56 is a hydraulic motor for traveling left (left traveling motor), the flow control valve 5a is for traveling right, the flow control valve 5b is for bucket, and the flow control valve 5c is for first boom. , Flow control valve 5
d is for the second arm, flow control valve 5e is for turning, flow control valve 5f is for the first arm, flow control valve 5g is for the second boom, flow control valve 5h is for backup, flow control valve 5i is for left traveling. Is. That is, the boom cylinder 52 is provided with the two flow rate control valves 5g and 5c, and the arm cylinder 54
Is also provided with two flow rate control valves 5d and 5f, so that the pressure oils from the two hydraulic pumps 1 and 2 can be merged and supplied to the bottom sides of the boom cylinder 52 and the arm cylinder 54, respectively. ing.

An operation pilot system for the flow control valves 5a-5i is shown in FIG.

The flow rate control valves 5i and 5a are operated by the operation pilot pressures TR from the operation pilot devices 39 and 38 of the operation device 35.
The flow control valve 5b and the flow control valves 5c, 5g are operated by the operation pilot device 4 of the operation device 36 by 1, TR2 and TR3, TR4.
By the operation pilot pressures BKC, BKD and BOD, BOU from 0, 41, the flow control valves 5d, 5f and the flow control valve 5e are operated by the operation pilot pressures ARC, ARD and SW1, Flow control valve 5h by SW2
Is the operating pilot pressure AU1, from the operating pilot device 44
Switching operation is performed by AU2.

The operation pilot devices 38 to 44 respectively include a pair of pilot valves (pressure reducing valves) 38a, 38b to 4 respectively.
4a, 44b, and operation pilot devices 38, 39,
Reference numeral 44 indicates the operation pedals 38c, 39c and 44c, respectively.
And the operation pilot devices 40, 41 further have a common operation lever 40c, and the operation pilot devices 42, 43
Further has a common operating lever 42c. Operation pedals 38c, 39c, 44c and operation levers 40c, 42
When c is operated, the pilot valve of the related operation pilot device operates according to the operation direction, and the operation pilot pressure according to the operation amount is generated.

Further, shuttle valves 61 to 67 are connected to the output lines of the pilot valves of the operation pilot devices 38 to 44, and shuttle valves 68, 69, 100 to 103 are hierarchically arranged on the shuttle valves 61 to 67. Connected to the
Shuttle valves 61, 63, 64, 65, 68, 69, 10
1, the maximum operating pilot pressure of the operating pilot devices 38, 40, 41, 42 is detected as the control pilot pressure PL1 of the hydraulic pump 1, and the shuttle valves 62, 64,
The maximum pressure of the operation pilot pressures of the operation pilot devices 39, 41, 42, 43, 44 is detected as the control pilot pressure PL2 of the hydraulic pump 2 by 65, 66, 67, 69, 100, 102, 103.

The above-described hydraulic drive system is provided with an engine / pump control device equipped with the torque control device for the hydraulic pump of the present invention. The details will be described below.

In FIG. 1, the hydraulic pumps 1 and 2 are provided with regulators 7 and 8, respectively. Control to control the pump discharge flow rate.

Regulators 7 and 8 of hydraulic pumps 1 and 2
Are tilt actuators 20A and 20B (hereinafter, represented by 20 as appropriate) and first servo valves 21A, which perform positive tilt control based on the operation pilot pressures of the operation pilot devices 38 to 44 shown in FIG. 3, respectively. 21B (hereinafter, appropriately represented by 21) and second servo valves 22A, 22B (hereinafter, appropriately represented by 22) for controlling the total horsepower of the hydraulic pumps 1 and 2 are provided.
2 from the pilot pump 9 to the tilt actuator 2
The pressure of the hydraulic oil acting on 0 is controlled, and the tilted positions of the hydraulic pumps 1 and 2 are controlled.

The tilt actuator 20 and the first and second servo valves 21, 22 will be described in detail.

Each tilting actuator 20 has an operating piston 20c having a large diameter pressure receiving portion 20a and a small diameter pressure receiving portion 20b at both ends, and pressure receiving chambers 20d and 20e in which the pressure receiving portions 20a and 20b are located. When the pressures in the pressure receiving chambers 20d and 20e are equal, the working piston 20c moves to the right in the figure, whereby tilting of the swash plate 1a or 2a becomes smaller, the pump discharge flow rate decreases, and the pressure receiving chamber 20d on the large diameter side decreases. When the pressure decreases, the working piston 20c moves to the left in the drawing, whereby tilting of the swash plate 1a or 2a becomes large and the pump discharge flow rate increases. In addition, the pressure receiving chamber 20 on the large diameter side
d is connected to the discharge passage 9a of the pilot pump 9 via the first and second servo valves 21 and 22, and is connected to the pressure receiving chamber 2 on the small diameter side.
0e is directly connected to the discharge passage 9a of the pilot pump 9.

Each first servo valve 2 for positive tilt control
Reference numeral 1 is a valve that operates by the control pressure from the solenoid control valve 30 or 31 to control the tilted positions of the hydraulic pumps 1 and 2. When the control pressure is high, the valve body 21a moves to the right in the drawing, and the pilot The pilot pressure from the pump 9 is transmitted to the pressure receiving chamber 20d without being reduced, the tilt of the hydraulic pump 1 or 2 is reduced, and the valve body 2 is reduced as the control pressure decreases.
1a moves to the left in the drawing by the force of the spring 21b to reduce the pilot pressure from the pilot pump 9 to reduce the pressure in the pressure receiving chamber 20d.
To increase the tilt of the hydraulic pump 1 or 2.

Each second servo valve 22 for total horsepower control is a valve that operates by the discharge pressure of the hydraulic pumps 1 and 2 and the control pressure from the solenoid control valve 32 to control the total horsepower of the hydraulic pumps 1 and 2. Yes, the solenoid control valve 32 limits the maximum absorption torque of the hydraulic pumps 1 and 2.

That is, the discharge pressures of the hydraulic pumps 1 and 2 and the control pressure from the solenoid control valve 32 are introduced into the pressure receiving chambers 22a, 22b, 22c of the operation drive unit, respectively, and the hydraulic pressures of the discharge pressures of the hydraulic pumps 1 and 2 are increased. Is lower than a set value determined by the difference between the elastic force of the spring 22d and the hydraulic pressure of the control pressure guided to the pressure receiving chamber 22c, the valve body 22e moves to the right in the figure, and the pilot pressure from the pilot pump 9 is moved. Is transmitted to the pressure receiving chamber 20d to increase the tilt of the hydraulic pumps 1 and 2, and as the sum of the hydraulic pressures of the discharge pressures of the hydraulic pumps 1 and 2 becomes higher than the set value, the valve body 22a becomes Moving to the left in the drawing, the pilot pressure from the pilot pump 9 is transmitted to the pressure receiving chamber 20d without being reduced, and the hydraulic pump 1,
Decrease the tilt of 2. When the control pressure from the solenoid control valve 32 is low, the set value is increased to increase the hydraulic pumps 1 and 2 from the higher discharge pressure.
Of the hydraulic pumps 1 and 2 is decreased, and the set value is decreased as the control pressure from the solenoid control valve 32 increases, and the tilts of the hydraulic pumps 1 and 2 are decreased from the lower discharge pressure of the hydraulic pumps 1 and 2.

The solenoid control valves 30, 31, 32 are proportional pressure reducing valves which are operated by the drive currents SI1, SI2, SI3. When the drive currents SI1, SI2, SI3 are minimum, the control pressure to be output becomes maximum, As the drive currents SI1, SI2, SI3 increase, the output control pressure decreases. Drive current
SI1, SI2, SI3 are output from the controller 70 shown in FIG.

The prime mover 10 is a diesel engine,
A fuel injection device 14 is provided. This fuel injection device 14
Has a governor mechanism and controls the engine speed so as to reach the target engine speed NR1 according to the output signal from the controller 70 shown in FIG.

The type of the governor mechanism of the fuel injection device is an electronic governor control device for controlling to a target engine speed by an electric signal from a controller, or a motor connected to a governor lever of a mechanical fuel injection pump, There is a mechanical governor control device that drives a motor to a predetermined position based on a command value from a controller to control a governor lever position. Any type of fuel injection device 14 of the present embodiment is effective.

The prime mover 10 has a target engine speed input section 7 in which an operator manually inputs a target engine speed.
1, the input signal of the target engine speed NR0 is taken into the controller 70 as shown in FIG. 4, the signal of the target speed NR1 is output from the controller 70 to the fuel injection device 14, and the speed of the prime mover 10 is increased. Is controlled.
The target engine speed input unit 71 may be directly input to the controller 70 by an electrical input means such as a potentiometer, and the operator selects the reference engine speed level.

Further, a rotation speed sensor 72 for detecting the actual rotation speed NE1 of the prime mover 10 and pressure sensors 73, 74 for detecting the control pilot pressures PL1, PL2 of the hydraulic pumps 1, 2.
(See FIG. 3) are provided.

Further, as a sensor for detecting the environment of the prime mover 10, an atmospheric pressure sensor 75 and a fuel temperature sensor 7 are provided.
6, cooling water temperature sensor 77, intake air temperature sensor 78,
An intake pressure sensor 79, an exhaust temperature sensor 80, an exhaust pressure sensor 81, and an engine oil temperature sensor 82 are provided, and an atmospheric pressure sensor signal TA, a fuel temperature sensor signal TF, a cooling water temperature sensor signal TW, and an intake temperature sensor signal TI, respectively. , Intake pressure sensor signal PI, Exhaust temperature sensor signal TO, Exhaust pressure sensor signal PO, Engine oil temperature sensor signal TL are output.

FIG. 4 shows the input / output relationship of signals of the entire controller 70. The controller 70 inputs the signal of the target engine speed NR0 of the target engine speed input unit 71 as described above, and outputs the signal of the target engine speed NR1.
4 to control the rotation speed of the prime mover 10.

Further, the controller 70 has a signal of the actual rotation speed NE1 of the rotation speed sensor 72 and pressure sensors 73 and 74.
Pump control pilot pressure PL1, PL2 signals, environmental sensor 75-82 atmospheric pressure sensor signal TA, fuel temperature sensor signal TF, cooling water temperature sensor signal TW, intake temperature sensor signal TI, intake pressure sensor signal PI, exhaust temperature The sensor signal TO, the exhaust pressure sensor signal PO, and the engine oil temperature sensor signal TL are input, predetermined arithmetic processing is performed, and the drive currents SI1, SI2, SI3 are output to the solenoid control valves 30 to 32, and the hydraulic pumps 1 and 2 are output. The tilt position, that is, the discharge flow rate is controlled.

The processing functions relating to the control of the hydraulic pumps 1 and 2 of the controller 70 are shown in FIGS.

In FIG. 5, the controller 70 includes pump target tilt calculators 70a and 70b, solenoid output current calculators 70c and 70d, a base torque calculator 70e, a rotation speed deviation calculator 70f, a torque converter 70g, and a limiter calculator. 70h, speed sensing torque deviation correction unit 7
0i, a base torque correction unit 70j, and a solenoid output current calculation unit 70k.

The pump target tilt calculation unit 70a inputs a signal of the control pilot pressure PL1 on the hydraulic pump 1 side, refers to this signal in a table stored in the memory, and responds to the control pilot pressure PL1 at that time. The target tilt θR1 of the hydraulic pump 1 is calculated. This target tilt θR1 is a reference flow metering for positive tilt control with respect to the manipulated variable of the pilot operating devices 38, 40, 41, 42, and the target tilt θR1 is also stored in the memory table as the control pilot pressure PL1 increases. The relationship between PL1 and θR1 is set to increase.

The solenoid output current calculation unit 70c determines that θR1
In contrast, a drive current SI1 for tilt control of the hydraulic pump 1 that obtains this θR1 is obtained, and this is output to the solenoid control valve 30.

Similarly, the pump target tilt calculation unit 70b and the solenoid output current calculation unit 70d also calculate the drive current SI2 for tilt control of the hydraulic pump 2 from the signal of the pump control pilot pressure PL2, and use this to calculate the solenoid control valve. Output to 31.

The base torque calculation unit 70e inputs a signal of the target engine speed NR0, refers to this signal in a table stored in the memory, and obtains a pump base torque TRO corresponding to the target engine speed NR0 at that time. calculate. In the memory table, NR0 and TR are set so that the pump base torque TRO increases as the target engine speed NR0 increases.
O relationship is set.

The engine speed deviation calculating section 70f is provided with a engine speed deviation ΔN which is a difference between the target engine speed NR1 and the actual engine speed NE1.
To calculate.

The torque converter 70g multiplies the speed deviation ΔN by the speed sensing gain KN to calculate the speed sensing torque deviation ΔTO.

The limiter calculation unit 70h multiplies the speed sensing torque deviation ΔTO by the upper and lower limit limiter to obtain the speed sensing torque deviation ΔT1.

Speed sensing torque deviation correction unit 70
i is calculated from this speed sensing torque deviation ΔT1 as shown in FIG.
The torque correction value ΔTFL obtained in the process of 1 is subtracted to obtain the torque deviation ΔTNL.

The base torque correction unit 70j adds the torque deviation ΔTNL to the pump base torque TRO calculated by the base torque calculation unit 70e to obtain the absorption torque TR1. this
TR1 becomes the target maximum absorption torque of the hydraulic pumps 1 and 2.

Solenoid output current calculation unit 70k
Against TR3, the drive current SI3 of the solenoid control valve 32 for controlling the maximum absorption torque of the hydraulic pumps 1 and 2 is obtained.
And outputs this to the solenoid control valve 32.

The solenoid control valve 32 that has received the drive current SI3 in this way operates on the hydraulic pumps 1 and 2 as described above.
Control the maximum absorption torque of.

In FIG. 6, the controller 70 further has respective functions of correction gain calculation units 70m to 70u, torque correction value calculation unit 70v, input timing control units 96a to 96h, and memory input / output control units 97a to 97h. ing.

The input timing control section 96a sends the atmospheric pressure sensor signal TA to the memory input / output control section 9 at a predetermined time interval TTA based on the function of the timer 88 shown in FIG.
7a, and the memory input / output control unit 97a loads the atmospheric pressure sensor signal TA into the memory as the atmospheric pressure sensor memory value MTA.

The correction gain calculation unit 70m inputs the atmospheric pressure sensor memory value MTA stored in the memory via the memory input / output control unit 97a, and stores this as an atmospheric pressure sensor signal TA in a table stored in the memory. To calculate a correction gain KTA according to the atmospheric pressure sensor signal TA. The correction gain KTA is a value stored in advance for the characteristics of the engine alone.
The same applies to other correction gains described below.

Here, since the output of the engine decreases when the atmospheric pressure decreases, the correction gain KTA correspondingly increases in the memory table as the atmospheric pressure sensor signal TA decreases. The relationship between the atmospheric pressure sensor signal TA and the correction gain KTA is set.

The input timing control section 96b inputs the fuel temperature sensor signal TF to the memory input / output control section 97b at a predetermined time interval TTF based on the function of the timer 88 shown in FIG. 97b shows the fuel temperature sensor signal TF as the fuel temperature sensor memory value MTF.
As in the memory.

The correction gain calculation unit 70n inputs the fuel temperature sensor memory value MTF stored in the memory through the memory input / output control unit 97b, and uses this as a fuel temperature sensor signal TF in a table stored in the memory. To calculate the correction gain KTF according to the fuel temperature sensor signal TF at that time.

Since the output decreases when the fuel temperature is low or high, the memory gain correspondingly increases the correction gain KTF as the fuel temperature sensor signal TF decreases. The relationship between the fuel temperature sensor signal TF and the correction gain KTF is set so that the correction gain KTF increases as the fuel temperature sensor signal TF increases.

The input timing control section 96c inputs the cooling water temperature sensor signal TW to the memory input / output control section 97c at a predetermined time interval TTW based on the function of the timer 88 shown in FIG. The section 97c stores the cooling water temperature sensor signal TW in the memory as the cooling water temperature sensor memory value MTW.

The correction gain calculation unit 70p inputs the cooling water temperature sensor memory value MTW stored in the memory through the memory input / output control unit 97c, and stores it in the memory as the cooling water temperature sensor signal TW. A certain table is referred to, and a correction gain KTW corresponding to the cooling water temperature sensor signal TW at that time is calculated.

Since the output decreases when the cooling water temperature is low or high, the correction gain KTW increases correspondingly as the cooling water temperature sensor signal TW decreases in the memory table. In addition, the relationship between the cooling water temperature sensor signal TW and the correction gain KTW is set so that the correction gain KTW increases as the cooling water temperature sensor signal TW increases.

The input timing control section 96d inputs the intake air temperature sensor signal TI to the memory input / output control section 97d at a predetermined time interval TTI based on the function of the timer 88 shown in FIG. 97d shows the intake air temperature sensor signal TI as the intake air temperature sensor memory value MTI
As in the memory.

The correction gain calculation unit 70q inputs the intake air temperature sensor memory value MTI fetched in the memory through the memory input / output control unit 97d, and stores this as an intake air temperature sensor signal TI in a table stored in the memory. To calculate the correction gain KTI according to the intake air temperature sensor signal TI at that time.

Since the output decreases when the intake air temperature is low or high, the correction gain KTI correspondingly increases as the intake air temperature sensor signal TI decreases in the memory table. In addition, as the intake air temperature sensor signal TI increases, the correction gain KTI also increases so that the intake air temperature sensor signal T
The relationship between I and the correction gain KTI is set.

The input timing control unit 96e inputs the intake pressure sensor signal PI to the memory input / output control unit 97e at a predetermined time interval TPI based on the function of the timer 88 shown in FIG. 97e shows the intake pressure sensor signal PI as the intake pressure sensor memory value MPI
As in the memory.

The correction gain calculation unit 70r inputs the intake pressure sensor memory value MPI stored in the memory through the memory input / output control unit 97e, and uses this as an intake pressure sensor signal PI in a table stored in the memory. To calculate the correction gain KPI according to the intake pressure sensor signal PI at that time.

Since the output decreases when the intake air pressure is low or high, the correction gain KPI correspondingly increases as the intake pressure sensor signal PI decreases in the memory table. , And so that the correction gain KPI increases as the intake pressure sensor signal PI increases,
The relationship between I and the correction gain KPI is set.

The input timing control section 96f inputs the exhaust temperature sensor signal TO to the memory input / output control section 97f at a predetermined time interval TTO based on the function of the timer 88 shown in FIG. 97f shows the exhaust temperature sensor signal TO as the exhaust temperature sensor memory value MTO
As in the memory.

The correction gain calculation unit 70s inputs the exhaust gas temperature sensor memory value MTO stored in the memory via the memory input / output control unit 97f, and stores this as an exhaust gas temperature sensor signal TO in a table stored in the memory. To calculate the correction gain KTO according to the exhaust temperature sensor signal TO at that time.

Since the output decreases when the exhaust temperature is low or high, the correction gain KTO increases correspondingly as the exhaust temperature sensor signal TO decreases in the memory table. Moreover, the relationship between the exhaust temperature sensor signal TO and the correction gain KTO is set so that the correction gain KTO increases as the exhaust temperature sensor signal TO increases.

The input timing control section 96g inputs the exhaust pressure sensor signal PO to the memory input / output control section 97g at a predetermined time interval TPO based on the function of the timer 88 shown in FIG. 97g shows the exhaust pressure sensor signal PO as the exhaust pressure sensor memory value MPO
As in the memory.

The correction gain calculation unit 70t inputs the exhaust pressure sensor memory value MPO stored in the memory through the memory input / output control unit 97g, and stores this as an exhaust pressure sensor signal PO in a table stored in the memory. To calculate a correction gain KPO corresponding to the exhaust pressure sensor signal PO at that time.

Here, since the output decreases as the exhaust pressure increases, the table of the memory correspondingly corresponds to this, so that the correction gain KPO increases as the exhaust pressure sensor signal PO increases. The relationship between the pressure sensor signal PO and the correction gain KPO is set.

The input timing control section 96h inputs the engine oil temperature sensor signal TL to the memory input / output control section 97h at a predetermined time interval TTL based on the function of the timer 88 shown in FIG. Part 97h
Captures the engine oil temperature sensor signal TL in the memory as the engine oil temperature sensor memory value MTL.

The correction gain calculation unit 70u determines the engine oil temperature sensor memory value MTL stored in the memory.
Is input via the memory input / output control unit 97h, and this is referred to the table stored in the memory as the engine oil temperature sensor signal TL, and the correction gain KTL corresponding to the engine oil temperature sensor signal TL at that time is set. Calculate

Since the output decreases when the engine oil temperature is low or high, the correction gain KTL increases correspondingly as the engine oil temperature sensor signal TL decreases in the memory table. And the correction gain KTL increases as the engine oil temperature sensor signal TL increases.
Relationship with KTL is set.

In the above, the time intervals TTA, TTF, TTW, T
Considering the characteristics of each sensor signal, TI, TPI, TTO, TPO, and TTL are set short for sensor signal values that change little during work, and for sensor signal values that change greatly during work. It is set long. An example of the time interval is shown below.

TTA: 1 hour TTF: 10 to 20 minutes TTW: 1 minute TTI: 30 minutes TPI: 40 minutes TTO: 10 to 100 ms TPO: 10 to 100 ms TTL: 5 minutes The torque correction value calculation unit 70v uses the above correction. The correction gains calculated by the gain calculators 70m to 70u are weighted to calculate the torque correction value ΔTFL. In this calculation method, the amount of output reduction for each correction gain is grasped in advance for the performance peculiar to the engine, and the reference torque correction value ΔT for the torque correction value ΔTFL to be obtained.
Provide B internally as a constant. Furthermore, the weighting of each correction gain is grasped in advance, and the correction amount of the weighting is provided inside the controller as matrices A, B, C, D, E, F, G, and H. Using these values, the torque correction value ΔTFL is calculated by the calculation shown in the torque correction value calculation block of FIG.

Although the calculation formula of FIG. 6 is expressed by a linear expression, the purpose thereof is to calculate the final torque correction value ΔTFL, and therefore the same effect can be obtained even if it is calculated by a quadratic expression or the like.

In the above, the target engine speed input unit 71 constitutes an input means for instructing the target speed of the prime mover (engine) 10, and the rotation speed sensor 72 is the first detecting means for detecting the actual speed of the prime mover. The base torque calculation unit 70e, the rotation speed deviation calculation unit 70f, and the torque conversion unit 7 are configured.
0g, limiter calculation unit 70h, base torque correction unit 70
j, the solenoid output current calculation unit 70k, the solenoid control valve 32, and the second servo valves 22A and 22B calculate the deviation between the target rotational speed and the actual rotational speed, and the maximum absorption torque of the hydraulic pumps 1 and 2 based on the deviation. Speed sensing control means for controlling the.

Further, the environment sensors 75 to 82 constitute second detecting means for detecting the state quantity related to the environment of the prime mover 10, the input timing control sections 96a to 96h, the memory input / output control sections 97a to 97h, and the correction gain. Calculation unit 70m ~
70u is the prime mover 1 based on the detection value of the second detecting means.
For each state quantity related to the environment of 0, an individual calculation means for calculating the influence quantity of the output change corresponding to the detected value of the state quantity at that time from the relationship between the predetermined state quantity and the influence quantity of the output change of the prime mover is provided. The torque correction value calculation unit 70v and the speed sensing torque deviation correction unit 70i form a torque correction unit that corrects the maximum absorption torque of the hydraulic pumps 1 and 2 according to the calculation value of the individual calculation unit.

Further, the input timing control units 96a to 96 are provided.
h is provided in the individual calculation means, and constitutes an input control means for inputting the detection value of the second detection means at a predetermined time interval for each state quantity related to the environment of the prime mover 10.

The speed sensing control means, the second detection means, the individual calculation means, the torque correction means, and the input control means constitute the torque control device for the hydraulic pump of the present invention.

Next, the characteristics of the operation of the present embodiment having the above configuration will be described.

FIG. 7 shows the engine output torque and pump absorption torque (engine negative torque) according to the torque control system of the present embodiment .
It is a figure which shows the matching point of ( load) . FIG. 8 is a diagram showing, for comparison, a matching point between the engine output torque and the hydraulic pump absorption torque (engine load) by the conventional torque control device. Both of these matching points are those when the output torque of the engine is normal and when the output decreases due to changes in the environment when the target rotation speed is constant. In the figure,
“A” is the normal engine output torque curve, and “B” is the output.
Engine output torque curve when force is reduced, "C" is speed
Maximum speed of pump maximum absorption torque during sensing control
"Gas" is the fuel injection device (cover
This is a regulation characteristic line of the mechanism. Also, FIG.
"C" of the broken line of is the speed sensing gain at the normal time,
The solid line "C" is the speed sensing gain when the output drops.
Is.

Here, as the conventional speed sensing control, the speed sensing torque deviation correction unit 7 of FIG. 5 is used.
There is no 0i, and the speed sensing torque deviation ΔT1 obtained by the limiter calculation unit 70h is directly used as the base torque correction unit 70j.
Is added to the pump base torque TRO, and the target maximum absorption torque is assumed.

First, the reduction in engine output changes depending on the environment surrounding the engine. For example, if the altitude to be used is high, the engine output torque decreases from curve A to curve B as the atmospheric pressure decreases.

Engine load (absorption torque of hydraulic pump)
When is light, the point on the regulation characteristic line D of the fuel injection device (governor mechanism) becomes the matching point between the engine load and the output torque. If the target speed is Na, the output of the engine will decrease regardless of the engine output when the load is light. The engine speed is, for example, a point Na0 on the regulation characteristic line D of the governor mechanism, which is slightly higher than the target speed Na. this is,
This embodiment of FIG. 7 and the prior art of FIG. 8 are the same.

When the engine load increases, points on the engine output torque curves A and B become matching points of the engine load and the output torque. This point is called the maximum torque matching point.

At the time of normal output, the maximum torque matching point is the point Ma on the engine output torque curve A corresponding to the target rotational speed Na. While the excavator is working, the engine speed changes from Na0 to N as the load changes from light to high.
Matching point of engine load and output torque decreases to a
Is the maximum torque matching point Ma . This also applies to the present embodiment shown in FIG. 7 and the conventional technique shown in FIG.

When the engine output decreases due to a change in the environment, in the case of the conventional technique, the maximum absorption torque of the hydraulic pump is decreased by the speed sensing control according to the decrease of the engine speed (the increase of the speed deviation ΔN). At this time, the ratio of the decrease in the pump maximum absorption torque to the decrease in the engine speed (increase in the rotation speed deviation ΔN) is determined by the gain KN of the torque converter 70g shown in FIG. When this is called the speed sensing gain of the pump maximum absorption torque, the slope of the characteristic “C” in FIG. 8 corresponds to this.

In the conventional speed sensing control, FIG.
Since there is no speed sensing torque deviation correction unit 70i, the characteristic of the speed sensing gain C is constant even if the engine output decreases due to changes in the environment. Therefore, when the engine output decreases from the curve A to the curve B when the engine load increases, the maximum absorption torque of the hydraulic pump decreases according to the characteristics of the speed sensing gain C according to the decrease of the engine speed by the speed sensing control. Then, the absorption torque of the hydraulic pump and the output torque of the engine become equal at the point of Ma1, and they match. That is, the maximum
The luck matching point moves from Ma to Ma1.

As described above, when the engine output decreases due to the change of environment, the engine speed changes from Na0 to Na1 as the load changes from light to high during the operation of the hydraulic excavator.
(<Na).

For example, when excavating at a high altitude, when the bucket is empty, the engine speed becomes Na0 which is slightly higher than the target speed Na input by the operator, but when excavating earth and sand, the engine speed becomes higher. Is Na1
Declines to.

As a result, noise and vibration of the vehicle body due to the engine speed change, which makes the operator feel tired.

In contrast to the above-described conventional technique, in the case of the present embodiment, when the output of the engine decreases due to the change of environment, the sensors 75 to 82 detect the change of environment, and the correction gain calculation units 70m to 70u and the torque. Correction value calculation unit 70v
Inputs the signal to estimate a decrease in engine output as a torque correction value ΔTFL, and the speed sensing torque deviation correction unit 70i and the base torque correction unit 70j subtract the torque correction value ΔTFL from the speed sensing torque deviation ΔTI to obtain a torque deviation ΔTNL. Is added to the pump base torque TRO to obtain the absorption torque TR1 (target maximum absorption torque). This process is equivalent to the target maximum absorption torque TR1 being reduced in advance by calculating the amount of engine output reduction due to environmental changes as the torque correction value ΔTFL, and reducing the pump base torque TRO by this amount. Figure as the torque decreases (as the torque correction value ΔTFL increases)
The speed sensing sensor of the pump maximum absorption torque shown in 7
The characteristic of IN C moves downward from the broken line to the solid line by the torque correction value ΔTFL.

As a result, the matching point with the pump absorption torque when the engine output is reduced becomes Ma2, the engine speed is the same as Na at the normal output, and good workability with little decrease in the engine speed can be secured. .

Further, according to the present invention, even when the output of the prime mover is lowered due to the change in the environment as described above, when the load is high,
Although the decrease in the rotation speed of the prime mover is reduced, a large number of sensors 75 to 82 are required for this purpose. When there are a large number of sensors as described above, if the signals of all the sensors are directly input and stored in the memory, and the torque correction value is calculated, the processing capacity of the controller 70 is limited. Spends a lot of time on capture, especially the controller 70
If other processing functions are built in, the processing speed becomes slow.

However, the sensor value has a different character depending on the type of the environmental state quantity which is the object of detection, and there are some that have large and some that have an orthodox variation. For example, atmospheric pressure does not change significantly during the work of a hydraulic excavator, so that the sensor values do not change significantly during work. The same applies to the sensor values of intake air temperature and intake air pressure. On the other hand, the engine oil temperature has a non-constant rate of progress depending on the working condition, and changes greatly during working. The same applies to sensor values of fuel temperature, cooling water temperature, exhaust temperature, and exhaust pressure.

In the present embodiment, paying attention to such a difference in the character of the sensor value, the input timing control sections 96a to 96h are provided for the memory input / output control sections 97a to 97h for the respective sensor signals, and the operation is in progress. The sensor signal is stored in the memory at a long time interval for a sensor value with a small change, and the sensor signal is stored in the memory for a short time interval for a sensor value with a large change during work. For example, sensor signals T from the atmospheric pressure sensor 75, the intake temperature sensor 78, and the intake pressure sensor 79.
For A, TI, PI, TTA: 1 hour, TTI: 30 minutes, TP
I: The sensor signal is taken into the memory at a time interval of 40 minutes. Therefore, the sensor signal TA,
Compared to the case where TI and PI are stored in the memory, the processing amount of the controller 70 is reduced, the controller 70 has a margin, and relatively fast processing can be performed even when other processing is performed. Further, the fuel temperature sensor 76, the cooling water temperature sensor 77, the exhaust temperature sensor 80, the exhaust pressure sensor 8
1. Sensor signal T of engine oil temperature sensor 82
For F, TW, TO, PO, TL, TTF: 10-20 minutes, TT
W: 1 minute, TTO: 10 to 100 ms, TPO: 10 to 100
ms, TTL: By retrieving the sensor signal in the memory at relatively short time intervals such as 5 minutes and correcting the torque, the rotation speed of the prime mover decreases when the output of the prime mover decreases due to changes in the environment as described above. Can be reduced.

As described above, according to this embodiment, even when the engine output is reduced due to a change in the environment, it is possible to reduce the reduction in the engine speed at a high load and ensure good workability.

Further, the speed sensing for always controlling the absorption torque of the hydraulic pump due to the rotational speed deviation is carried out as usual, and the engine is stopped even when a sudden load is applied or the output of the engine is unexpectedly decreased. It can be prevented.

Further, since the speed sensing control is performed, it is not necessary to set the absorption torque of the hydraulic pump in advance with a margin, and the engine output can be effectively used as it is. For example, it is possible to prevent the engine from being stopped when the engine load is high even if the engine output decreases due to variations in the performance of the equipment or changes over the years.

Further, since the processing capacity of the controller 70 can be effectively used, even if the controller 70 performs other processing with the limited processing capacity of the controller 70, relatively fast processing can be performed.

In the above embodiment, the speed sensing torque deviation correcting unit 70i subtracts the torque correction value ΔTFL from the speed sensing torque deviation ΔTI, but the base torque correcting unit 70j subtracts the torque correction value ΔTFL from the torque deviation ΔTNL. The good thing is of course.

A second embodiment of the present invention will be described with reference to FIGS. In the figure, the same components as those shown in FIGS. 5 to 7 are designated by the same reference numerals.

In FIG. 9, the controller includes pump target tilt calculation units 70a, 70b, solenoid output current calculation units 70c, 70d, base torque calculation unit 70e, rotation speed deviation calculation unit 70Af, torque conversion unit 70g, limiter calculation unit. It has respective functions of 70h, a base torque correction unit 70j, and a solenoid output current calculation unit 70k.

The rotational speed deviation calculation unit 70Af calculates the rotational speed deviation ΔN by obtaining the difference between the target engine rotational speed NR1 and the actual engine rotational speed NE1, and further subtracting the rotational speed correction value ΔNFL obtained by the processing of FIG. To do.

In the torque conversion unit 70g, the rotation speed deviation ΔN is multiplied by the speed sensing gain KN to calculate the speed sensing torque deviation ΔTO. Speed sensing torque deviation ΔT1
Then, the base torque correction unit 70j obtains the absorption torque TR1 (target maximum absorption torque) from the speed sensing torque deviation ΔT1 and the pump base torque TRO.

Other than that, it is the same as the first embodiment shown in FIG.

In FIG. 10, the controller further includes
The correction gain calculation units 70m to 70u, the rotation speed correction value calculation unit 70Av, the input timing control units 96a to 96h, and the memory input / output control units 97a to 97h are provided.

Input timing control sections 96a to 96h, memory input / output control sections 97a to 97h, correction gain calculation section 7
The processing from 0 m to 70 u is the same as in the first embodiment shown in FIG.

The rotation speed correction value calculation unit 70Av weights the correction gains calculated by the correction gain calculation units 70m to 70u to calculate the rotation speed correction value ΔNFL. This calculation method preliminarily grasps the amount of output reduction for each correction gain for the engine-specific performance, and internally sets the reference rotation speed correction value ΔNB for the rotation speed correction value ΔNFL to be obtained as a constant. Prepare Furthermore, the weighting of each correction gain is grasped in advance, and the correction amount of the weighting is provided inside the controller as matrices A, B, C, D, E, F, G, and H. Using these values, the rotation speed correction value ΔTFL is calculated by the calculation shown in the rotation speed correction value calculation block in FIG.

Also in this case, the same effect can be obtained even if the calculation formula of FIG. 6 is calculated by, for example, a quadratic formula.

The drive current SI3 generated by the solenoid output current calculator 70j is output to the solenoid control valve 32 shown in FIG. 1 to control the maximum absorption torque of the hydraulic pumps 1 and 2 as described above.

In the above, in this embodiment, the input timing control units 96a to 96h and the memory input / output control unit 97 are used.
a to 97h, the correction gain calculation units 70m to 70u are the first
The second detection means (environment sensor 75
Based on the detected value of (1) to (82), the output corresponding to the detected value of the state quantity at that time from the relationship between the predetermined state quantity and the influence quantity of the output change of the prime mover for each state quantity related to the environment of the prime mover 10. An individual calculation means for calculating the influence amount of change is configured,
Rotation speed correction value calculation unit 70Av, rotation speed deviation calculation unit 70A
f constitutes a torque correction means for correcting the maximum absorption torque of the hydraulic pumps 1 and 2 according to the calculated value of the individual calculation means.

In the present embodiment configured as described above, when the output of the engine decreases due to a change in the environment, the signals from the sensors 75 to 82 are input and the correction gain calculating unit 70m is input.
.About.70u and the engine speed correction value calculation unit 70Av estimate the engine output decrease as the engine speed correction value ΔNFL, and the engine speed deviation calculation unit 70Af further corrects the engine speed from the deviation between the target engine speed NR1 and the actual engine speed NE1. Reduce the value ΔNFL,
The speed sensing torque deviation ΔTNL is calculated from the reduced rotation speed deviation ΔN, and the absorption torque TR1 (target maximum absorption torque) is calculated. This process is equivalent to the target maximum absorption torque TR1 is reduced in advance by calculating the engine output reduction amount due to the change in the environment as the rotation speed correction value ΔNFL and reducing the target engine rotation speed NRO by this amount.
As the engine output decreases (as the rotational speed correction value ΔTFL increases), the characteristic of the gain C of speed sensing of the pump maximum absorption torque shown in FIG. 11 is the rotational speed correction value ΔNFL.
Is moved to the left in the figure.

As a result, the matching point with the pump absorption torque when the engine output decreases is Ma2 point as in the first embodiment shown in FIG. 7, and the engine speed is the same as Na at the normal output.

Therefore, according to this embodiment, it is possible to secure good workability with a small decrease in the engine speed, and
The same effects as those of the first embodiment can be obtained by preventing the engine from stopping even when a sudden load is applied by the speed sensing control or when the output of the engine is unexpectedly reduced.

Also in this embodiment, the input / output timing control sections 96a to 96h are provided for the memory input / output control sections 97a to 97h for the respective sensor signals, so that it takes a long time for the sensor values which change little during work. Since the sensor signal is fetched in the memory at intervals and the sensor signal is fetched in the memory at short time intervals for the sensor value which changes greatly during the work, the controller 70 has a margin and can perform a fast process.

In the above embodiment, the target engine speed NR1 and the actual engine speed N are calculated by the engine speed deviation calculation unit 70Af.
The engine speed correction value ΔNFL was further reduced from the deviation of E1.This is the same as subtracting the engine speed correction value ΔNFL from the target engine speed NR1 from the actual engine speed NE1. A means for adding the rotation speed correction value ΔNFL to the number NR1 may be provided, and the rotation speed deviation calculation unit 70Af may subtract this addition value from the actual engine rotation speed NE1.

The third embodiment of the present invention will be described with reference to FIG. The present embodiment relates to the processing of the sensor value and further reduces the processing amount of the controller. In the figure, FIG.
The same functions as those shown in are given the same reference numerals.

In FIG. 12, the controller according to the present embodiment has correction gain calculation units 70m to 70u, a torque correction value calculation unit 70v, and input timing control units 96a to 9c.
6h, the memory input / output control units 97a to 97h, and further has respective functions of operation timing control units 98a to 98h and memory input / output control units 99a to 99h.

Correction gain calculation units 70m to 70u, torque correction value calculation unit 70v, input timing control units 96a to 9
6h, processing in the memory input / output control units 97a to 97h is the same as that of the first embodiment shown in FIG.

The calculation timing control unit 98a has a predetermined time interval TTA based on the function of the timer 88 shown in FIG.
The correction gain calculation unit 70m is activated by the correction gain calculation unit 70m, and the correction gain calculation unit 70m receives the atmospheric pressure sensor memory value MTA stored in the memory at the time interval TTA.
It is input via 7a and the correction gain KTA is calculated using this as the atmospheric pressure sensor signal TA. Calculation timing control unit 9
Similarly, 8b to 98h have predetermined time intervals TTF, TTW, TTI, TPI, TT based on the function of the timer 88 shown in FIG.
The correction gain calculation units 70n to 70u are activated by O, TPO, and TTL, and the correction gain calculation units 70n to 70u start the time interval TT.
F, TTW, TTI, TPI, TTO, TPO, TTL, the respective sensor memory values MTF, MTW, MT loaded in the memory
I / MPI, MTO, MPO, MTL are memory input / output control units 97b-
Input via 97h, and input this to each sensor signal
Correction gains KTF, KT as TF, TW, TI, PI, TO, PO, TL
Calculate W, KTI, KPI, KTO, KPO, KTL.

The memory input / output control unit 99a loads the value of the correction gain KTA calculated by the correction gain calculation unit 70m into the memory as the correction gain memory value MKTA. Similarly, the memory input / output control units 99b to 99h also have the correction gains KTF, KTW, KTI, K calculated by the correction gain calculation units 70n to 70u.
Correction gain memory values MKTF, M for PI, KTO, KPO, KTL values
Capture in memory as KTW, MKTI, MKPI, MKTO, MKPO, MKTL.

The torque correction value calculation unit 70v has the correction gain memory values MKTA, MKTF, MKTW,
MKTI, MKPI, MKTO, MKPO, MKTL correction gain LTA, KTF,
KTW, KTI, KPI, KTO, KPO, and KTL are input via the memory input / output control units 99a to 99h, and the correction gain is weighted to calculate the torque correction value ΔTFL.

According to the present embodiment configured as described above, since the correction gain calculation units 70m to 70u perform calculation at predetermined time intervals, the processing amount of the controller is further reduced and the processing capacity of the controller is further increased. It can be used effectively and the processing speed of the controller can be further increased.

[0150]

According to the present invention, even when the output of the prime mover is reduced due to a change in the environment, it is possible to reduce the decrease in the rotational speed of the prime mover at a high load, and to ensure good workability.

Further, since the speed sensing control is performed as before, it is possible to prevent the prime mover from stopping even when the output of the prime mover is lowered due to a sudden load or an unexpected situation.

Further, since the speed sensing control is performed, it is not necessary to set the absorption torque of the hydraulic pump in advance with a margin, and the output of the prime mover can be effectively used as in the conventional case. For example, even if the output of the prime mover decreases due to variations in the performance of the equipment or changes over the years, it is possible to prevent the prime mover from stopping during high load.

Further, according to the present invention, since the processing capacity of the controller can be effectively used, relatively fast processing can be performed with the limited processing capacity of the controller.

[Brief description of drawings]

FIG. 1 is a diagram showing an engine / pump control device provided with a torque control device for a hydraulic pump according to a first embodiment of the present invention.

FIG. 2 is a hydraulic circuit diagram of a valve device and an actuator connected to the hydraulic pump shown in FIG.

FIG. 3 is a diagram showing an operation pilot system of the flow control valve shown in FIG.

FIG. 4 is a diagram showing an input / output relationship of the controller shown in FIG.

FIG. 5 is a functional block diagram showing a part of processing functions of a controller.

FIG. 6 is a functional block diagram showing another part of the processing functions of the controller.

FIG. 7 is a diagram showing a matching point between an engine output torque and a pump absorption torque under speed sensing control according to the first embodiment.

FIG. 8 is a diagram showing matching points between engine output torque and pump absorption torque according to conventional speed sensing control.

FIG. 9 is a functional block diagram showing a part of processing functions of the controller according to the second embodiment of the present invention.

FIG. 10 is a functional block diagram showing another part of the processing functions of the controller.

FIG. 11 is a diagram showing a matching point between an engine output torque and a pump absorption torque under speed sensing control according to the second embodiment.

FIG. 12 is a functional block diagram showing a part of processing functions of a controller according to a third embodiment of the present invention.

[Explanation of symbols]

1, 2 hydraulic pump 1a, 2a swash plate 5 valve device 7,8 regulator 10 prime mover 14 Fuel injection device 20A, 20B tilting actuator 21A, 21B 1st servo valve 22A, 22B Second servo valve 30-32 solenoid control valve 38-44 Operation pilot device 50-56 actuator 70 controller 70a, 70b Pump target tilt calculation unit 70c, 70d Solenoid output current calculator 70e Base torque calculation unit 70f Rotation speed deviation calculation unit 70Af Rotational speed deviation calculator 70g torque converter 70h limiter calculation unit 70i Speed sensing torque deviation correction unit 70j Base torque correction unit 70k solenoid output current calculator 70m-70u Correction gain calculation unit 70v torque correction value calculator 70Av rotation speed correction value calculation unit 71 Target engine speed input section 72 speed sensor 73,74 Pressure sensor 75 atmospheric pressure sensor 76 Fuel temperature sensor 77 Cooling water temperature sensor 78 Intake air temperature sensor 79 Intake pressure sensor 80 Exhaust temperature sensor 81 Exhaust pressure sensor 82 Engine oil temperature sensor 88 timer 96a to 96h Input timing control unit 97a-97h Memory input / output control unit 98a to 98h Operation timing control unit 99a-99h Memory input / output control unit

Continuation of the front page (56) Reference JP-A-59-37286 (JP, A) JP-A-60-195338 (JP, A) JP-A-4-5487 (JP, A) JP-A-57-65822 (JP , A) JP 55-102002 (JP, A) JP 11-182443 (JP, A) JP 8-135475 (JP, A) JP 6-280808 (JP, A) JP 4-258418 (JP, A) JP-A-9-177679 (JP, A) JP-A-62-265481 (JP, A) JP-A-10-89305 (JP, A) JP-B-62-8618 (JP, A) B2) (58) Fields investigated (Int.Cl. ⁷ , DB name) F02D 29/00-29/06 F04B 49/00

Claims (9)

(57) [Claims] 1. A prime mover, a variable displacement hydraulic pump driven by the prime mover, input means for instructing a target speed of the prime mover, and a first detecting the actual speed of the prime mover.
Torque control device for hydraulic pump of hydraulic construction machine, comprising: detection means; speed sensing control means for calculating a deviation between the target speed and actual speed and controlling the maximum absorption torque of the hydraulic pump based on the deviation. In detecting a plurality of state quantities related to the environment of the prime mover,
Based on the detection means and the detection value of the second detection means, for each state quantity related to the environment of the prime mover, the state quantity at that time is calculated from the relationship between the predetermined state quantity and the influence quantity of the output change of the prime mover. Individual calculating means for calculating the influence amount of the output change corresponding to the detected value, and the speed sensor according to the calculated value of the individual calculating means.
Torque correction means for correcting the maximum absorption torque of the hydraulic pump controlled by the engine control means, and the detection value of the second detection means provided in the individual calculation means, for each state quantity related to the environment of the prime mover in advance. A torque control device for a hydraulic pump of a hydraulic construction machine, comprising input control means for inputting at a predetermined time interval. 2. The torque control device for a hydraulic pump of a hydraulic construction machine according to claim 1, wherein the input control means is means for storing a detection value of the second detection means in a memory at the predetermined time interval. A torque control device for a hydraulic pump of a hydraulic construction machine, wherein the individual calculation means calculates the amount of influence of the output change using the detection value stored in the memory. 3. The torque control device for a hydraulic pump of a hydraulic construction machine according to claim 1, wherein the input control means causes the individual calculation means to detect the detection value of the second detection means at the predetermined time interval. The individual calculation means includes means for calculating the influence amount of the output change using the detection value acquired at the predetermined time interval, and acquiring the calculated value in a memory. Torque control device for hydraulic pump of hydraulic construction machinery. 4. The torque control device for a hydraulic pump of a hydraulic construction machine according to claim 1, wherein the input control means sets the time interval for a detected value of a state quantity that is small in change during the operation of the hydraulic construction machine. Is set to be long, and the time interval is set to be short for the detected value of the state quantity that is largely changed during the operation of the hydraulic construction machine, the torque control device for the hydraulic pump of the hydraulic construction machine. 5. A torque control device for a hydraulic pump of a hydraulic construction machine according to claim 1, wherein the individual calculation means is, for each state quantity related to the environment of the prime mover, an influence quantity of the state quantity and an output change of the prime mover. The relationship between the state quantity and the correction gain of the output change of the prime mover is stored in advance as a relationship with, and the output change correction corresponding to the detected value of the state quantity at that time as the influence quantity of the output change is stored from this relationship. A torque control device for a hydraulic pump of a hydraulic construction machine, which calculates a gain. 6. A torque control device for a hydraulic pump of a hydraulic construction machine according to claim 1, wherein said torque correction means obtains a torque correction value of said hydraulic pump in accordance with a calculation value of said individual calculation means, A torque control device for a hydraulic pump of a hydraulic construction machine, wherein the maximum absorption torque of the hydraulic pump is corrected based on a correction value. 7. A torque control device for a hydraulic pump of a hydraulic construction machine according to claim 1, wherein said torque correction means obtains a rotation speed correction value of said prime mover in accordance with a calculation value of said individual calculation means, A torque control device for a hydraulic pump of a hydraulic construction machine, wherein the maximum absorption torque of the hydraulic pump is corrected based on a number correction value. 8. A torque control device for a hydraulic pump of a hydraulic construction machine according to claim 1, wherein the speed sensing control means calculates a pump base torque in accordance with the target rotational speed and also in accordance with the rotational speed deviation. The first means for calculating the speed sensing torque deviation by adding the speed sensing torque deviation to the pump base torque to obtain the target maximum absorption torque of the hydraulic pump, and the maximum value of the hydraulic pump based on the target maximum absorption torque. A second means for limiting and controlling the capacity, wherein the torque correction means calculates a torque correction value for the target maximum absorption torque according to the calculation value of the individual calculation means, and the first means. This torque correction value is subtracted when adding the speed sensing torque deviation to the pump base torque with Torque control system for a hydraulic construction machine hydraulic pump and having a fourth means for correcting the torque. 9. The torque control device for a hydraulic pump of a hydraulic construction machine according to claim 1, wherein the speed sensing control means calculates a pump base torque according to the target rotational speed, and the actual rotational speed is used to calculate the pump base torque. A first rotation speed is subtracted to obtain a target rotation speed deviation, and the pump base torque is corrected according to the rotation speed deviation to obtain a target maximum absorption torque of the hydraulic pump.
Means and second means for limiting and controlling the maximum displacement of the hydraulic pump based on the target maximum absorption torque, the torque correction means with respect to the target rotation speed based on the calculation value of the individual calculation means. Third means for calculating a rotation speed correction value; and torque control of a hydraulic pump of a hydraulic construction machine, wherein the rotation speed correction value is further reduced when the target rotation speed is subtracted from the actual rotation speed by the first means. apparatus.