JP2001248186A - Control device for construction machine - Google Patents

Abstract

PROBLEM TO BE SOLVED: To enhance the operational efficiency of a control device for a construction machine by enhancing the efficiency of an entire system through a reduction in loss of engine outputs, and making efficient use of the engine outputs. SOLUTION: The control device includes a plurality of engine-driven hydraulic pumps 51 and 52 for discharging hydraulic fluid in a tank; a plurality of operating members 54a to 54d operated by an operator; and control means 1 for controlling the tilt angles of the plurality of hydraulic pumps 51 and 52 to adjust the rate of discharge from the plurality of hydraulic pumps 51 and 52. The control means 1 control the tilt angles of the plurality of hydraulic pumps 51 and 52 in accordance with electric signals from the plurality of operating members 54a to 54d so that the engine outputs from the engine are optimally distributed to the plurality of hydraulic pumps 51 and 52.

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention controls the flow rate of hydraulic oil from a hydraulic pump provided in a construction machine by a control valve to control the operation of hydraulic actuators such as a boom cylinder, a stick cylinder, a bucket cylinder, and a swing motor. The present invention relates to a control device of a construction machine for controlling.

[0002]

2. Description of the Related Art Generally, construction machines such as hydraulic excavators are
As shown in FIG. 12, the upper revolving unit 102 and the lower traveling unit 1
00 and a working device 118. Undercarriage 1
00 is a right track 100R that can be driven independently of each other.
And the left track 100L. On the other hand, the upper swing body 102 is provided so as to be able to swing in a horizontal plane with respect to the lower traveling body 100. Therefore, the upper rotating body 102
A working motor 118 is attached to the boom 10.
3, a stick 104, a bucket 108, and the like, and the boom 103 is pivotally attached to the upper swing body 102. Also, at the tip of the boom 103,
Similarly, a stick 104 is rotatably connected in the vertical plane.

[0003] A boom drive hydraulic cylinder (boom cylinder, boom drive hydraulic actuator) 105 for driving the boom 103 is provided between the upper swing body 102 and the boom 103.
Between the stick 3 and the stick 104, a stick driving hydraulic cylinder (stick cylinder, stick driving hydraulic actuator) for driving the stick 104
106 is provided. Further, between the stick 104 and the bucket 108, a bucket driving hydraulic cylinder (bucket cylinder,
A bucket driving hydraulic actuator 107 is provided.

The cylinders 105 to 107 and the swing motor are provided with a plurality of (generally two) hydraulic pumps driven by an engine (mainly a diesel engine), a control valve for a boom, a control valve for a stick, A hydraulic circuit (not shown) including a plurality of control valves such as a bucket control valve and a turning control valve is connected, and hydraulic oil of a predetermined hydraulic pressure is supplied from these hydraulic pumps via each control valve. ,
It is driven in accordance with the operating hydraulic pressure supplied in this way.

With such a configuration, the boom 103 moves in the directions of arrows a and b in the figure, the stick 104 moves in the directions of arrows c and d in the figure, and the bucket 108 moves in the directions of arrows e and f in the figure. It is configured to be rotatable. The rotation of the boom 103 in the direction of the arrow a in the figure is called boom up, and the rotation in the direction of the arrow b in the figure is called boom down. The rotation of the stick 104 in the direction of the arrow c in the figure is called stick-out, and the rotation in the direction of the arrow d in the figure is called stick-in. Also, the bucket 108
Rotation in the direction of arrow e in the figure is called bucket open,
Rotation in the direction of arrow f in the figure is called bucket-in.

The driving operation room 101 includes left lever, right lever, and left pedal as operation members for controlling the operation (running, turning, boom turning, stick turning, and bucket turning) of the hydraulic excavator. And a right pedal and the like. A plurality of work mode switches are also provided in the driver's cab 101, and various modes such as a truck loading mode (boom priority mode), a trenching mode (swing priority mode), a leveling mode, and a tamping mode are provided. The driving operator can appropriately select an optimum one according to the work. In a normal case where such a selection is not made, the operation of the stick 104 is important in the operation of the construction machine, and the operation of the stick 104 needs to be given the highest priority. It has become.

[0007] When an operator operates these operating members such as levers and pedals, the control valves of the hydraulic circuit are controlled, and the cylinders 105 to 107 are controlled.
And a swing motor are driven, whereby the boom 103,
By rotating the stick 104, the bucket 108, and the like, the upper swing body 102 can be swung. Further, a pilot hydraulic circuit is provided to control each control valve. Thereby, in order to operate the boom 103 and the stick 104, the boom operation member and the stick operation member in the operation room 101 are operated, and the pilot oil pressure is applied to the boom control valve and the stick control valve through the pilot oil passage. Then, the boom control valve and the stick control valve are driven to required positions. This allows
Supply and discharge of hydraulic oil to the boom drive hydraulic cylinder 105 and the stick drive hydraulic cylinder 106 are adjusted, and these cylinders 105 and 106 are driven to expand and contract to required lengths.

In order to operate the upper revolving unit 102, a turning operation member in the operation room 101 is operated.
The pilot hydraulic pressure is applied to the turning control valve through the pilot oil passage to move the turning control valve to a required position. As a result, the supply and discharge of hydraulic oil to and from the swing motor are adjusted, and the swing motor is driven. As described above, in the hydraulic shovel, the cylinders 105 to 107 are driven to expand and contract to drive the working devices 118 such as the boom 103, the stick 104, and the bucket 108, and to turn the upper turning body 102 by driving the turning motor. Excavation such as wall scraping work and leveling work, digging such as excavation work, and lift /
A turning operation and the like are performed.

Here, at the time of excavation, the stick-in operation and the turning operation are performed simultaneously. At the time of digging, the stick-in operation and the bucket operation are performed simultaneously. Further, during the lift / turn, the boom-up operation and the turn operation are performed simultaneously. During these operations, hydraulic oil is supplied from each of the plurality of hydraulic pumps to each hydraulic actuator. In this case, since these hydraulic pumps are driven by one engine, the engine output from the engine is used according to the pump load of each hydraulic pump on the engine. Note that the engine output includes engine power, engine torque, and engine horsepower output from the engine.

[0010]

However, in the control of the conventional hydraulic pump, the engine output (total horsepower, total pump horsepower) required to drive the plurality of hydraulic pumps and the engine output between the plurality of hydraulic pumps are required. The distribution (horsepower distribution between a plurality of hydraulic pumps) is set as a fixed value.

For example, if the maximum horsepower of the engine is about 140 horsepower (about 140 PS; about 102.20 kW), the total horsepower (total pump horsepower) of the plurality of hydraulic pumps driven by this one engine is about 140 horsepower. (About 140
PS; about 102.20 kW). Also, the horsepower distribution among the plurality of hydraulic pumps is generally set to be approximately equal and fixed.

If the total horsepower and the horsepower distribution are fixedly set as described above, the horsepower loss increases depending on the working conditions (for example, the magnitude of the load pressure and the combination of the actuating actuators), and the work becomes necessary. If sufficient force (power) cannot be obtained or sufficient work speed cannot be obtained, work efficiency will be reduced. Looking at the relationship between the fixedly set engine horsepower (total horsepower and total pump horsepower) and the load pressure, under the condition that the horsepower is fixed at a fixed value, if the load pressure is low, the hydraulic pump will Although the flow rate of the discharged hydraulic oil increases (pump flow rate = horsepower (constant) / load pressure), if the flow rate of the hydraulic oil discharged from the hydraulic pump increases, the pressure loss of the piping system increases, and the horsepower due to the pipe pressure loss Since the loss increases, the effective horsepower (effective operating oil pressure) that can be supplied to the hydraulic actuator among the engine horsepower (pump horsepower) decreases, and a sufficient force (power) necessary for the work cannot be obtained.

Further, the horsepower loss due to the pipe pressure loss becomes heat and raises the temperature of the hydraulic oil, and due to the temperature rise, the viscosity of the hydraulic oil decreases and the internal leak of hydraulic equipment increases, The efficiency of the hydraulic system (the efficiency of supplying hydraulic oil to the hydraulic actuator) is deteriorated, and the work efficiency is deteriorated without obtaining a sufficient work speed. Furthermore, a large oil cooler is required to prevent an excessive rise in operating oil temperature, and when a cooling fan is provided, extra horsepower is required to drive the cooling fan. .

Next, a look at the relationship of horsepower distribution (horsepower distribution of engine horsepower) among a plurality of hydraulic actuators shows a case where a plurality of operating members are operated in conjunction to operate a plurality of hydraulic actuators simultaneously. In addition, there are hydraulic actuators that preferentially operate powerfully, and hydraulic actuators that only need to operate minimally.

For example, when performing excavation work by simultaneously performing the stick-in and the bucket-in, the stick 104 is a working machine that the user prefers to operate with high priority and the bucket 108 operates with the minimum operation. It is a good work machine if you can give it. By the way, in consideration of such an operation pattern (for example, when a plurality of hydraulic actuators are simultaneously operated like excavation work), the hydraulic circuit is configured such that the hydraulic pumps corresponding to each hydraulic actuator are respectively connected. Have been.

However, for example, even if the second hydraulic pump is connected to the stick driving hydraulic cylinder 106 via an oil passage and the first hydraulic pump is connected to the bucket driving hydraulic cylinder 107, When both the first hydraulic pump and the second hydraulic pump are driven by one engine and the horsepower distribution between the first hydraulic pump and the second hydraulic pump is equally divided, a stick to be preferentially operated Since a sufficient amount of hydraulic oil is not supplied to the driving hydraulic cylinder 106 and sufficient hydraulic pressure cannot be obtained, the stick 104 cannot be powerfully operated and work efficiency (work cycle time, etc.) is improved. Absent.

Here, more engine horsepower (pump horsepower) is applied to the hydraulic pump (in the above example, the second pump connected to the stick driving hydraulic cylinder 106) connected to the hydraulic actuator that wants to be powerfully operated. ) Can improve work efficiency. However, if it is attempted to uniformly perform both the control for variably setting the total horsepower in accordance with the load pressure applied to the work implement and the control for varying the horsepower distribution among a plurality of hydraulic pumps regardless of the type of work. However, the following problems may occur.

For example, when performing control to variably set the total horsepower in accordance with the load pressure applied to the work implement, the horsepower is set to be uniformly reduced in accordance with the load pressure regardless of the type of work. If this happens, the work efficiency will be reduced depending on the type of work. For example, if the total horsepower is set to be smaller in accordance with the load pressure at the time of the boom up, a problem that the cycle time becomes longer occurs. For this reason, when the boom is raised, it is necessary to use the full horsepower of the engine horsepower as the pump horsepower of each hydraulic pump in the full load pressure range.

Further, when performing control for variably setting the horsepower distribution among a plurality of hydraulic pumps, if the horsepower distribution is uniformly performed regardless of the combination of a plurality of hydraulic actuators to be operated, a plurality of hydraulic power Depending on the combination of actuators, optimal horsepower distribution is not performed,
In some cases, the engine output cannot be used efficiently.

The present invention has been made in view of the above-described problems, and reduces the loss of the engine output to improve the efficiency of the entire system. An object of the present invention is to provide an improved control device for a construction machine.

[0021]

According to a first aspect of the present invention, there is provided a control apparatus for a construction machine according to the present invention, comprising a plurality of hydraulic pumps driven by an engine provided in the construction machine to discharge hydraulic oil in a tank. A plurality of operating members operated by an operator; and control means for controlling tilt angles of the plurality of hydraulic pumps to adjust discharge flow rates from the plurality of hydraulic pumps. Is characterized in that the tilt angles of the plurality of hydraulic pumps are controlled based on electric signals from the plurality of operating members so that can be optimally distributed to the plurality of hydraulic pumps.

According to a second aspect of the present invention, there is provided a construction machine control apparatus according to the first aspect, wherein the control means sets a distribution ratio of an engine output distributed to each of the plurality of hydraulic pumps, and It is characterized in that the tilt angles of each of the plurality of hydraulic pumps are controlled so as to be the ratio. According to a third aspect of the present invention, there is provided a control device for a construction machine according to the first aspect, further comprising a pressure sensor for detecting a pump discharge pressure of hydraulic oil discharged by a plurality of hydraulic pumps, and Set the engine output distributed to each of the multiple hydraulic pumps based on the upper limit output set according to the detection signal from the sensor, and control the tilt angle of each of the multiple hydraulic pumps so as to achieve the distributed output It is characterized by doing.

According to a fourth aspect of the present invention, there is provided a construction machine control device according to the first aspect, wherein the plurality of operation members are operated to turn the construction machine, and the construction machine is turned. A stick operating member operated to operate a stick provided in the vehicle, wherein the control means performs an excursion involving a turning operation and a stick operation based on an electric signal from the turning operation member and the stick operating member. Pump displacement angle control means for controlling the displacement angle of the hydraulic pump so as to adjust the discharge flow rate from the hydraulic pump; Means, when the excavation determination means determines that the operation is an excavation operation, the engine output from the engine is output to the plurality of hydraulic pumps. It is characterized by controlling the respective tilt angles of the plurality of hydraulic pumps based on the electric signal from the rotation operation member and the operation member for the stick so that it can optimally distributed, respectively.

According to a fifth aspect of the present invention, there is provided a control device for a construction machine according to the fourth aspect, further comprising a pressure sensor for detecting a pump discharge pressure of hydraulic oil discharged by a plurality of hydraulic pumps. The turning angle control means is allocated to each of the plurality of hydraulic pumps by subtracting a minimum turning required output required to turn the construction machine from an upper limit output set according to a detection signal from the pressure sensor. The present invention is characterized in that an engine output is set and a tilt angle of each of the plurality of hydraulic pumps is controlled so as to obtain a distributed output.

According to a sixth aspect of the present invention, there is provided a construction machine control device according to the first aspect, wherein the plurality of operation members are operated to operate a stick provided on the construction machine. And a bucket operating member operated to operate a bucket provided in the construction machine, wherein the control means performs a stick operation and a bucket operation based on an electric signal from the stick operating member and the bucket operating member. Digging determination means for determining whether or not the operation is accompanied by digging work, and pump tilt angle control means for controlling the tilt angle of the hydraulic pump so as to adjust the discharge flow rate from the hydraulic pump. The engine output from the engine when the digging operation is determined to be a digging operation. It is characterized by controlling the respective tilt angles of the plurality of hydraulic pump based on the electrical signal from the operation member and the bucket operation member stick to be optimally distributed to, respectively.

According to a seventh aspect of the present invention, there is provided a control device for a construction machine according to the sixth aspect, further comprising a pressure sensor for detecting a pump discharge pressure of hydraulic oil discharged by a plurality of hydraulic pumps. The turning angle control means is distributed to each of the plurality of hydraulic pumps by subtracting the minimum required bucket output required to operate the bucket from the upper limit output set according to the detection signal from the pressure sensor. The invention is characterized in that the engine output is set and the tilt angles of the plurality of hydraulic pumps are controlled so as to achieve the distributed output.

According to an eighth aspect of the present invention, there is provided the control device for a construction machine according to the first aspect, wherein the plurality of operation members are operated to operate a boom provided on the construction machine. And, comprising a turning operation member operated to turn the construction machine, the control means,
Lift / turn determination means for determining whether or not a lift / turn involving a boom operation and a turn operation based on electric signals from the boom operation member and the turn operation member; and a discharge flow rate from the hydraulic pump. Pump tilt angle control means for controlling the tilt angle of the hydraulic pump for adjustment, wherein the pump tilt angle control means outputs a signal from the engine when the lift / turn determination means determines that the lift / turn is being performed. Controlling the tilt angles of the plurality of hydraulic pumps based on electric signals from the turning operation member and the boom operation member so that the engine output of the plurality of hydraulic pumps can be optimally distributed to each of the plurality of hydraulic pumps. I have.

According to a ninth aspect of the present invention, there is provided a control device for a construction machine according to the eighth aspect, further comprising a pressure sensor for detecting a pump discharge pressure of hydraulic oil discharged by a plurality of hydraulic pumps. The turning angle control means is allocated to each of the plurality of hydraulic pumps by subtracting a minimum turning required output required to turn the construction machine from an upper limit output set according to a detection signal from the pressure sensor. The present invention is characterized in that an engine output is set and a tilt angle of each of the plurality of hydraulic pumps is controlled so as to obtain a distributed output.

[0029]

Embodiments of the present invention will be described below with reference to the drawings. First, a construction machine according to the present embodiment will be described. The construction machine is a construction machine (working machine) such as a hydraulic shovel, as described in the related art (see FIG. 12), and includes the upper swing body 102, the lower traveling body 100, and the working device 118. I have.

The undercarriage 100 has a right track 100R and a left track 100L that can be driven independently of each other, while the upper revolving structure 102 is
It is provided so as to be pivotable in a horizontal plane with respect to 00. The working device 118 mainly includes the boom 103, the stick 104, the bucket 108, and the like.
3 is pivotally attached to the upper swing body 102 so as to be rotatable. A stick 104 is connected to the tip of the boom 103 so as to be rotatable in a vertical plane.

A boom drive hydraulic cylinder (boom cylinder, boom drive hydraulic actuator) 105 for driving the boom 103 is provided between the upper swing body 102 and the boom 103, and the boom 10
Between the stick 3 and the stick 104, a stick driving hydraulic cylinder (stick cylinder, stick driving hydraulic actuator) for driving the stick 104
106 is provided. Further, between the stick 104 and the bucket 108, a bucket driving hydraulic cylinder (bucket cylinder,
A bucket driving hydraulic actuator 107 is provided.

With such a configuration, the boom 1
03 is configured to be rotatable in the directions a and b in the figure, the stick 104 is rotatable in the directions c and d in the figure, and the bucket 108 is configured to be rotatable in the directions e and f in the figure. Here, FIG. 2 is a diagram schematically showing a main part of a hydraulic circuit of such a hydraulic shovel.

As shown in FIG. 2, the left track 10
0L and the right track 100R are provided with traveling motors 109L and 109R as independent power sources, respectively, and the upper revolving unit 102 is used for rotating the upper revolving unit 102 with respect to the lower traveling unit 100. A swing motor 110 is provided. These traveling motors 10
The 9L, 109R and the swing motor 110 are configured as hydraulic motors operated by hydraulic pressure, and as described later, a plurality (two in this case) of hydraulic pumps 51, driven by an engine (mainly, a diesel engine) 50 Hydraulic oil from 52 is supplied at a predetermined pressure via a hydraulic circuit 53, and each hydraulic motor 109L, 109R, 110 is driven in accordance with the hydraulic pressure supplied in this manner.

Here, the hydraulic pumps 51 and 52 discharge the working oil in the reservoir tank 70 as a predetermined oil pressure. Here, a swash plate rotary piston pump (piston type variable displacement pump, variable discharge amount type piston) is used. Pump). These hydraulic pumps 51 and 52 can adjust the pump discharge flow rate by changing the stroke amount of a piston (not shown) provided in the hydraulic pump.

That is, in these hydraulic pumps 51 and 52, one end of the piston is configured to contact a swash plate (creep plate: not shown), and the inclination (tilt angle) of the swash plate will be described later. By changing the stroke amount of the piston based on the operation signal from the controller 1 to adjust the pump discharge flow rate.

As described above, the inclination of the swash plate can be changed based on the operation signal from the controller 1.
Since the amount of operation of each operating member 54 by the operator can be taken into account in addition to the pressure of the hydraulic oil in the oil passages constituting the hydraulic circuit, the pressure of the hydraulic oil in the oil passages is derived as in the related art. As compared with the case where the inclination of the swash plate is changed, the driving feeling of the operator can be improved.

The engine 50 can be set by switching the engine speed setting dial by an operator. Here, the maximum engine speed (for example, about 2000 rpm) and the minimum engine speed (for example, about 2000 rpm) are set. (For example, about 1000 rpm). It should be noted that the engine speed is not limited to such a stepwise switching.
It may be one that can be changed smoothly.

The cylinders 105 to 107 are also supplied from a plurality (here, two) of hydraulic pumps 51 and 52 driven by the engine 50, similarly to the traveling motors 109L and 109R and the swing motor 110. It is driven by the hydraulic pressure of the working oil. The total horsepower of the engine 50 is equivalent to those of the hydraulic pumps 51,
52 and a pilot pump 83 described later.

The driving operation room 101 includes a left lever, a right lever, a left pedal, a right pedal, etc. for controlling the operation (running, turning, boom turning, stick turning, bucket turning) of the hydraulic shovel. Are provided. These operation members 54 are configured as electric operation members (for example, electric operation levers), and output an electric signal corresponding to the operation amount to a controller (control means) 1 described later.

Further, a plurality of work mode switches are also provided in the driving cab 101, and various modes such as a boom priority mode, a swing priority mode, a leveling mode, and a tamping mode are set by the driver according to the work. Therefore, the most suitable one can be appropriately selected. In a normal case where such a selection is not made, the operation of the stick 104 is important in the operation of the construction machine, and the operation of the stick 104 needs to be given the highest priority.

When the operator operates these operating members 54, for example, the control valves 57 to 60 and 62 to 65 interposed in the hydraulic circuit 53 are controlled, and the cylinders 105 to 107 and the hydraulic motor are controlled. 109L, 109
R, 110 is driven. Thereby, the upper rotating body 10
2 can be turned, the boom 103, the stick 104, the bucket 108 and the like can be rotated, and the hydraulic shovel can be run.

The members to be operated when rotating the boom 103 are the boom operating member 54a and the stick 10
4 is operated when rotating the bucket 4, the bucket operating member 54 c is operated when rotating the bucket 108, and the upper revolving body 102 is operated when rotating the bucket 108.
The operation member 54 for turning is operated when turning the
It is called d.

Next, the hydraulic circuit 53 for controlling these cylinders will be described. The hydraulic circuit 53
As shown in FIG. 2, a first circuit unit 55 and a second circuit unit 56
And The first circuit portion 55 includes an oil passage 61 connected to the first hydraulic pump 51, a control valve 57 for a right running motor, a control valve 58 for a bucket,
First boom control valve 59, second stick control valve 60
And the like.

Then, the operating oil from the first hydraulic pump 51 is supplied to the right traveling motor 109R through the oil passage 61 and the right traveling motor control valve 57 to drive the right traveling motor 109R. . Also, the first hydraulic pump 51
Is supplied to the bucket driving hydraulic cylinder 107 via the oil passage 61 and the bucket control valve 58, and the boom driving hydraulic cylinder 105 via the oil passage 61 and the first boom control valve 59. Is supplied to the hydraulic cylinder 106 for driving the stick via the oil passage 61 and the control valve 60 for the second stick, whereby the cylinders 105, 106, and 107 are driven.

A throttle 81 is provided on the downstream side of the oil passage 61 of the first circuit portion 55, and the hydraulic oil from the first hydraulic pump 51 is supplied to the reservoir tank 70 through the throttle 81.
To return to The second circuit portion 56 includes an oil passage 66 connected to the second hydraulic pump 52, a left traveling motor control valve 62, and a turning motor control valve 6 interposed in the oil passage 66.
3, a control valve such as a control valve 64 for the first stick, a control valve 65 for the second boom, and a throttle 82.

Then, the operating oil from the second hydraulic pump 52 is supplied to the left traveling motor 109L via the oil passage 66 and the left traveling motor control valve 62, whereby the left traveling motor 109L is driven. It has become. Also, the second
Hydraulic oil from the hydraulic pump 52 is supplied to the turning motor 110 via the oil passage 66 and the turning motor control valve 63, whereby the turning motor 110 is driven. Further, the hydraulic oil from the second hydraulic pump 52 is supplied to the stick driving hydraulic cylinder 106 via the oil passage 66 and the first stick control valve 64, and the oil passage 66 and the second boom control valve 65. , And is supplied to the boom driving hydraulic cylinder 105, whereby the respective cylinders 105 and 106 are driven.

A throttle 82 is provided on the downstream side of the oil passage 66 of the second circuit section 56, and the hydraulic oil from the second hydraulic pump 52 is supplied to the reservoir tank 70 through the throttle 82.
To return to In addition, each control valve 57-60,
62 to 65 are housed in a control unit (not shown).

As described above, in the present embodiment, the stick 104 important for the operation of the construction machine is attached to the other work machine 11.
In addition to the hydraulic oil from the second hydraulic pump 52 of the second circuit portion 56, the hydraulic oil from the first hydraulic pump 51 of the first circuit portion 55 Hydraulic oil is also supplied to the stick driving hydraulic cylinder 106.

For this reason, the first stick control valve 64 is interposed in the oil passage 66 of the second circuit portion 56, and the first circuit portion 55
The second stick control valve 60 is interposed in the oil passage 61 of the second stick. The first stick control valve 64 is controlled by the proportional control valves 64a and 64b, and the second stick control valve 60 is controlled by the proportional control valves 60a and 60b.
6 can be supplied and discharged.

Similarly, in addition to the hydraulic oil from the first hydraulic pump 51 of the first circuit section 55, the hydraulic oil is supplied from the first hydraulic pump 51 of the first circuit section 55 so that sufficient hydraulic oil is supplied to the boom 103 even during simultaneous operation with another working machine 118. Hydraulic oil from the second hydraulic pump 52 of the second circuit section 56 is also supplied to the boom drive hydraulic cylinder 105. Therefore, the oil passage 6 of the first circuit portion 55
1 is provided with a first boom control valve 59,
A second boom control valve 65 is interposed in the oil passage 66 of the second boom. Then, the first boom control valve 59 is changed to the proportional control valve 59.
a, 59b, and by controlling the second boom control valve 65 with the proportional control valves 65a, 65b, hydraulic oil can be supplied to and discharged from the boom drive hydraulic cylinder 105.

In this embodiment, the oil passage 6 for supplying and discharging the hydraulic oil to and from the hydraulic cylinder 106 for driving the stick is provided.
A regeneration valve 76 for a stick is interposed in 7, 68 so that a predetermined amount of hydraulic oil can be regenerated from the hydraulic oil discharge side oil passage to the hydraulic oil supply side oil passage. Similarly, boom regeneration valves 77 are also interposed in oil passages 78 and 79 for supplying and discharging hydraulic oil to and from the hydraulic cylinder 105 for boom drive. A predetermined amount of hydraulic oil can be regenerated.

Here, each control valve 57-60, 62-65
Are configured as spool valves as shown in FIG. 3, and each is provided with a plurality of (here, five) throttles. That is, each of the control valves 57 to 60 and 62 to 65
As shown in the figure, the first hydraulic pump 51 and the second hydraulic pump 5
2, a PC throttle 8 interposed in oil passages (hydraulic oil supply passages, PC passages) 61a and 66a communicating the stick 2 with the stick driving hydraulic cylinder 106, the stick driving hydraulic cylinder 106 and the reservoir tank 70. The first hydraulic pump 51, the second hydraulic pump 52, and the reservoir tank 70 communicate with the CT throttle 9 interposed in oil passages (hydraulic oil discharge passages, CT passages) 66b and 69 that communicate with the first hydraulic pump 51 and the second hydraulic pump 52. Passage restrictor 1 interposed in oil passages (bypass passages) 61b, 66c
0.

In FIG. 3, the stick control valve 60,
Although 64 is in the stick lowered position, the stick control valves 60 and 64 are moved upward in FIG.
Bypass passage throttle 10 for stick control valves 60 and 64
Are disposed in the bypass passages 61b and 66c, the stick control valves 60 and 64 can be set to the neutral position, and the stick control valves 60 and 64 are
Move the stick control valve 60, 6
The PC throttle 8 of FIG. 4 is interposed in the PC passages 61a and 66a, and the CT of the stick control valves 60 and 64 is controlled.
By interposing the throttle 9 in the CT passages 66b and 69,
The stick control valves 60, 64 can be in the stick up position.

In setting the diameters of the apertures 8, 9, and 10, the working device 1 such as the boom 103 or the stick 104 is used.
In order to ensure the interlocking of the 18, it is considered that all the working devices 118 move when each operating member 54 is fully operated. The opening areas of the oil passages 61a and 66a that connect the first hydraulic pump 51 and the second hydraulic pump 52 to the stick driving hydraulic cylinder 106 (opening area of the hydraulic oil supply passage, P- C opening area) is adjusted.

The opening area of the oil passages 66b and 69 (the opening area of the hydraulic oil discharge passage, the opening area of the CT opening) that connects the stick driving hydraulic cylinder 106 and the reservoir tank 70 is adjusted by the CT throttle 9. You. The first hydraulic pump 51 and the second hydraulic pump 5
Oil passages 61b, 66 communicating the reservoir 2 with the reservoir tank 70.
The opening area of c (the opening area of the bypass passage) is adjusted.

In the present embodiment, as shown in FIG. 2, the pilot pump 83 and the proportional pressure reducing valves 57a-60
a, 57b-60b, 62a-65a, 62b-65b
And a pilot hydraulic circuit comprising: In FIG. 2, the pilot pump 83 and the proportional pressure reducing valves 57a to 60a, 57b provided in the pilot hydraulic circuit are shown.
60b, 62a-65a, 62b-65b, and the pilot oil pressure is omitted by omitting the pilot oil passage.
Indicated by.

Here, the proportional pressure reducing valves 57a to 60a, 57
Reference numerals b to 60b, 62a to 65a, and 62b to 65b denote solenoid valves, which are operated by operation signals from the controller 1 described later. As a result, the pilot oil pressure from the pilot pump
Each of the control valves 57-
60, 62-65.

With such a configuration, for example, in order to rotate the upper revolving unit 102, the turning operation member 54d in the operation room 101 is operated, and the pilot oil pressure P from the pilot pump 83 is applied to a pilot oil passage (not shown). Through this, it acts on the swing motor control valve 63 to move the swing motor control valve 63 to a required position. This allows
Supply and discharge of hydraulic oil to and from the swing motor 110 are adjusted, whereby the swing motor 110 is operated.

For example, to turn the upper swing body 102 rightward, the swing motor 110 may be turned clockwise.
In this case, the pilot oil pressure is applied to the swing motor control valve 63 through the pilot oil passage. This allows
The turning motor control valve 63 is set to the right turning position, and the operating oil from the second hydraulic pump 52 of the second circuit portion 56 is supplied to the oil passage 66.
a, 96, the hydraulic oil in the left oil chamber of the swing motor 110 is supplied to the right oil chamber of the swing motor 110,
The oil is discharged to the reservoir tank 70 through the oil passages 97 and 66b. As a result, the turning motor 110 is turned clockwise, and the upper turning body 102 turns right.

Conversely, to rotate the upper swing body 102 to the left, the swing motor 110 may be rotated to the left. In this case, the pilot oil pressure is applied to the swing motor control valve 63 through the pilot oil passage. As a result, the turning motor control valve 63 is turned to the left turning position, and the operating oil from the second hydraulic pump 52 of the second circuit portion 56 is supplied to the oil passage 66.
a, 97, the hydraulic oil in the right oil chamber of the swing motor 110 is supplied to the left oil chamber of the swing motor 110,
The oil is discharged to the reservoir tank 70 through the oil passages 96 and 66b. As a result, the turning motor 110 is turned counterclockwise, and the upper turning body 102 turns left.

Further, in order to maintain the current state of the upper swing body 102, the pilot hydraulic pressure is applied to the swing motor control valve 63 as appropriate, and the spool position of the swing motor control valve 63 is set to the neutral position (hydraulic supply / discharge). (Road blocking position).
Accordingly, the supply and discharge of hydraulic oil in each oil chamber of the swing motor 110 is stopped, and the upper swing body 102 is held at the current position.

Further, for example, to operate the boom 103, the boom operating member 54 a in the operation room 101 is operated, and the pilot hydraulic pressure P
Is acted on the boom control valves 59 and 65 through a pilot oil passage (not shown) to move the boom control valves 59 and 65 to required positions. Thereby, the supply and discharge of the hydraulic oil of the boom drive hydraulic cylinder 105 is adjusted, and these cylinders 105 are driven to expand and contract to a required length, whereby the boom 103 is operated.

For example, to rotate the boom 103 downward (boom down), the boom driving hydraulic cylinder 10
5 may be contracted. In this case, the pilot oil pressure is made to act on the first boom control valve 59 through the pilot oil passage. As a result, the spool position of the first boom control valve 59 becomes the boom lower rotation position (boom down position), and the hydraulic oil from the first hydraulic pump 51 of the first circuit portion 55 flows through the oil passages 95 and 79. , And is supplied to one chamber of the boom driving hydraulic cylinder 105 and supplied to one chamber of the boom driving hydraulic cylinder 105. On the other hand, the hydraulic oil in the other chamber of the boom drive hydraulic cylinder 105 is supplied to the oil passages 78 and 6.
After that, it is discharged to the reservoir tank 70. Thereby, while the boom drive hydraulic cylinder 105 contracts,
The boom 103 is rotated downward as shown by the arrow b in FIG.

Conversely, to rotate the boom 103 upward (boom up), the boom drive hydraulic cylinder 10
5 may be extended. In this case, the pilot oil pressure is made to act on the first boom control valve 59 and the second boom control valve 65 through the pilot oil passage. Thereby, the first
The spool positions of the boom control valve 59 and the second boom control valve 65 become the boom upper rotation position (boom up position), and the hydraulic oil from the first hydraulic pump 51 of the first circuit portion 55 is supplied to the oil passage 95. , 78, and is supplied to one chamber of the boom driving hydraulic cylinder 105, and further, the hydraulic oil from the second hydraulic pump 52 of the second circuit portion 56 is supplied to the oil passages 66a, 90, 7,
After that, the boom drive hydraulic cylinder 105 is supplied to another chamber. On the other hand, the boom drive hydraulic cylinder 10
The hydraulic oil in one chamber of the fifth oil passage 79, 91, 66b or
The oil is discharged to the reservoir tank 70 through the oil passages 79 and 69. Thus, the boom 103 is rotated upward as shown by an arrow a in FIG. 12 while the boom drive hydraulic cylinder 105 is extended.

Further, the boom drive hydraulic cylinder 105
In order to maintain the current state, the pilot hydraulic pressure is applied to the first boom control valve 59 and the second boom control valve 65 as appropriate, and the first boom control valve 59 and the second boom control valve 65 are controlled.
Set the position of each spool to the neutral position (hydraulic supply / discharge path cutoff position)
What should I do? Accordingly, the supply and discharge of hydraulic oil in each oil chamber of the boom drive hydraulic cylinder 105 is stopped, and the boom 103 is held at the current position.

In order to operate the stick 104, for example, the operating member 54 in the operation room 101 is operated, and the pilot oil pressure P from the pilot pump 83 is passed through a pilot oil passage (not shown) to control the stick control valve 60, 64 to control the stick control valves 60, 6
4 is driven to a required position. This allows
The supply and discharge of the hydraulic oil for the stick driving hydraulic cylinder 106 is adjusted, and these cylinders 105 and 106 are driven to expand and contract to a required length, whereby the stick 104 is operated.

For example, to rotate the stick 104 inward (stick-in), the stick driving hydraulic cylinder 106 may be extended. In this case, the pilot oil pressure is applied to the second stick control valve 60 through the pilot oil passage. As a result, the spool position of the second stick control valve 60 becomes the stick inner rotation position (stick-in position), and the operating oil from the first hydraulic pump 51 of the first circuit portion 55 flows through the oil passages 61 and 67. After that, it is supplied to one chamber of the stick driving hydraulic cylinder 106. On the other hand, the stick driving hydraulic cylinder 1
06, the hydraulic oil in the other chamber is discharged to the reservoir tank 70 via the oil passages 68, 69. As a result, while the stick driving hydraulic cylinder 106 extends, the stick 1
04 is rotated inward as shown by arrow d in FIG.

Conversely, to rotate the stick 104 outward (stick-out), the stick driving hydraulic cylinder 106 may be contracted. In this case, the pilot oil pressure is applied to the second stick control valve 60 through the pilot oil passage. As a result, the spool position of the second stick control valve 60 becomes the stick outside rotation position (stick out position), and the hydraulic oil from the first hydraulic pump 51 of the first circuit portion 55 flows through the oil passages 61 and 68. After that, it is supplied to another chamber of the stick driving hydraulic cylinder 106. On the other hand, the stick driving hydraulic cylinder 1
Hydraulic oil in one room of 06 is discharged to the reservoir tank 70 through the oil passages 67 and 69. As a result, while the stick driving hydraulic cylinder 106 contracts, the stick 1
04 is rotated outward as shown by arrow c in FIG.

Further, the stick driving hydraulic cylinder 1
In order to maintain the current state of 06, the pilot oil pressure is applied to the second stick control valve 60 as appropriate, and the position of each spool of the second stick control valve 60 is set to the neutral position (the hydraulic supply / discharge path shutoff position). do it. Thus, the supply and discharge of hydraulic oil in each oil chamber of the stick driving hydraulic cylinder 106 is stopped, and the stick 104 is held at the current position.

In order to operate the bucket 108, for example, the bucket operating member 54c in the operation room 101 is operated.
, The pilot oil pressure P from the pilot pump 83 is applied to the bucket control valve 58 through a pilot oil passage (not shown) to move the bucket control valve 58 to a required position. Thereby, the supply and discharge of the hydraulic oil of the bucket driving hydraulic cylinder 107 is adjusted, and these cylinders 107 are driven to expand and contract to a required length.
The bucket 108 is operated.

For example, to rotate the bucket 108 inward (bucket-in), the bucket driving hydraulic cylinder 107 may be extended. In this case, the pilot hydraulic pressure is applied to the bucket control valve 58 through the pilot oil passage. Thereby, the spool position of the bucket control valve 58 is shifted to the bucket inner rotation position (bucket-in position).
Thus, the hydraulic oil from the first hydraulic pump 51 of the first circuit section 55 is supplied to one chamber of the bucket driving hydraulic cylinder 107 through the oil passages 61 and 92. On the other hand, hydraulic oil in the other chamber of the bucket driving hydraulic cylinder 107 is discharged to the reservoir tank 70 through the oil passages 93 and 69. This causes the bucket 108 to rotate inward as indicated by the arrow f in FIG. 12 while the bucket driving hydraulic cylinder 107 extends.

Conversely, to rotate the bucket 108 outward (bucket open), the bucket driving hydraulic cylinder 107 may be contracted. In this case, the pilot oil pressure is supplied to the bucket control valve 58 through the pilot oil passage.
To act on. As a result, the spool position of the bucket control valve 58 becomes the bucket outside rotation position (bucket open position), and the first hydraulic pump 51 of the first circuit portion 55
Is supplied to another chamber of the bucket driving hydraulic cylinder 107 through the oil passages 94 and 93. On the other hand,
Hydraulic oil in one chamber of the bucket driving hydraulic cylinder 107 is discharged to the reservoir tank 70 through the oil passages 92 and 69. Thereby, the bucket driving hydraulic cylinder 107
While contracting, the bucket 108 is rotated outward as shown by an arrow e in FIG.

Further, the bucket driving hydraulic cylinder 10
7, the pilot hydraulic pressure is applied to the bucket control valve 58 as appropriate to control the bucket control valve 58.
May be set to the neutral position (the hydraulic supply / discharge path shutoff position). Thereby, the supply and discharge of the hydraulic oil in the oil chamber of the bucket driving hydraulic cylinder 107 is stopped, and the bucket 108 is held at the current position.

By the way, various sensors are attached to the construction machine configured as described above, and a detection signal from each sensor is sent to a controller 1 described later. For example, an engine speed sensor 71 is attached to the engine 50 that drives the hydraulic pumps 51 and 52, and a detection signal from the engine speed sensor 71 is sent to the controller 1 described later. The controller 1 performs feedback control so that the actual engine speed becomes the target engine speed set by the engine speed setting dial by the operator.

The first hydraulic pump 5 of the first circuit section 55
On the discharge side of the second hydraulic pump 52 of the first and second circuit units 56, pressure sensors (P
/ S-P1) 72 and a pressure sensor (P / S-P2) 73, and detection signals from these pressure sensors 72, 73 are sent to the controller 1 described later.

The pressure sensors (P / P) are provided downstream of the control valves 57 to 60 of the oil passage 61 of the first circuit portion 55 and the control valves 62 to 65 of the oil passage 66 of the second circuit portion 56, respectively. S
-N1) 74 and a pressure sensor (P / S-N2) 75, and detection signals from these pressure sensors 74 and 75 are sent to the controller 1 described later.

A pressure sensor (P / S-BMd) is provided in an oil passage for supplying and discharging hydraulic oil to and from the boom drive hydraulic cylinder 105, that is, a rod side pressure (load pressure) of the boom drive hydraulic cylinder 105. ) 80 is provided, and a detection signal from the pressure sensor 80 is sent to the controller 1 described later. In the present embodiment, the controller 1 is provided to control the construction machine configured as described above.

The controller 1 controls each of the sensors 71 to 71 described above.
The first hydraulic pump 51, the second hydraulic pump 5 based on the detection signals from 75 and 80 and the electric signal from the operation member 54.
2, each regeneration valve 76, 77, each control valve 57-60, 62-
By outputting an operation signal to the first and second hydraulic pumps 65, 65, the tilt angle control of the first hydraulic pump 51 and the second hydraulic pump 52 and the control valves 57
60, 62 to 65, the position control of each of the regeneration valves 76 and 77, and the like.

The tilt angle control of the first hydraulic pump 51 and the second hydraulic pump 52 by the controller 1
Negative flow control is performed based on detection signals from respective pressure sensors 74 and 75 provided on the downstream side of the bypass passage 61b of the circuit portion 55 and on the downstream side of the bypass passage 66c of the second circuit portion 56. ing. Since the negative flow control is performed based on the pressures detected by the pressure sensors 74 and 75, the pressure detected by the pressure sensors 74 and 75 is also referred to as a negative control pressure.

Here, the negative flow control (electronic negative flow control system) is
This means a pump flow rate control having a negative characteristic such that the pump discharge flow rate is reduced when the pressure on the downstream side of the bypass passages 61b and 66c increases. Here, the pump is controlled by controlling the operation amount of each operating member 54, that is, the flow rate control in which the pump discharge flow rate is controlled according to the negative control pressure, and the load pressure applied to the actuator, that is, the pump discharge flow rate in accordance with the pump discharge pressure. Controlled horsepower control is divided into.

The flow control can control the speed of the actuator (each cylinder) within the allowable horsepower. That is, the pump discharge flow rate can be controlled in accordance with the operation amount of each operation member 54, that is, the negative control pressure.
The speed of the actuator can be controlled. By the way, when the operation members 54 are fully operated and the pump discharge flow rate is maximum and the actuator speed is maximum, the pump discharge flow rate (that is, the actuator speed) is determined by the following equation.

Pump discharge flow rate Q = allowable horsepower W / pump discharge pressure P In this state, if the load pressure applied to the actuator fluctuates, the pump discharge pressure P also fluctuates, and from the above equation, the pump discharge flow rate Q also fluctuates. Therefore, this also causes the speed of the actuator to fluctuate. As described above, the pump discharge flow rate Q is not controlled according to the operation amount of each operation member 54, but is controlled according to the load pressure applied to the actuator, that is, the pump discharge pressure P. Is called horsepower control in a state where the control depends on the allowable horsepower W of the engine 50 that drives the first hydraulic pump 51 and the second hydraulic pump 52.

When such horsepower control is performed, even if the operator fully operates each operation member 54 and requests the maximum speed of the actuator, the actual speed of the actuator is determined by the magnitude of the load pressure. become. In this case, the horsepower of the engine 50 becomes the allowable maximum value. Further, for example, when a plurality of actuators are simultaneously operated, even if each operation member 54 is not fully operated, the hydraulic oil is supplied to each actuator, the negative control pressure is reduced, and the required flow rate is reduced. When the flow rate exceeds the allowable flow rate determined by the allowable horsepower, the pump tilt angle control is performed so as to achieve the allowable flow rate in the horsepower control.

When the operating member 54 is in the neutral position, that is, when the operator is not operating the operating member 54, the working device 118 does not perform any work and it is not necessary to drive the actuator. The pump discharge flow from 52 is desirably zero. For this reason, in this embodiment, each control valve 57-60, 62-65.
Is an open center (spool neutral position and bypass passage 6
1b and 66c are open), and when the operating member 54 is in the neutral position, the hydraulic pump 5
Hydraulic oil supplied from the first and the second passages 52,
It returns to the reservoir tank 70 through 66c.

As a result, when the operating member 54 is at the neutral position, the pressure immediately upstream of the throttles 81, 82 provided downstream of the bypass passages 61b, 66c increases, and the variable capacity is controlled by negative flow control. The pump discharge flow rate from the hydraulic pumps 51 and 52 is controlled to decrease. On the other hand, when the operation member 54 is operated, an amount of hydraulic oil corresponding to the operation amount is supplied to each actuator (cylinder or the like), and the remaining hydraulic oil returns to the reservoir tank 70 through the bypass passages 61b and 66c. It has become.

As described above, the throttles (orifices) 81, 82 are provided downstream of the bypass passages 61b, 66c.
Is provided. The pressure sensors 7 are provided in the bypass passages 61b, 66c immediately upstream of the throttles 81, 82.
4, 75 are interposed, and the tilt angles of the hydraulic pumps 51, 52 are controlled based on the pressures immediately upstream of the throttles 81, 82 detected by the pressure sensors 74, 75. .

When the operator operates the operation member 54, the control valves 57 to 6 are controlled according to the operation amount of the operation member 54.
0, 62 to 65 move to bypass passages 61b, 66c.
And the flow rate of the hydraulic oil flowing through the bypass passages 61b and 66c decreases, but the diameters of the throttles 81 and 82 are constant. The pressure detected by the pressure sensors 74 and 75 decreases, and the tilting angle control of the variable displacement hydraulic pumps 51 and 52 is performed so that the pump discharge flow rate increases in accordance with the reduced pressure.

This means that the pump discharge flow rate is controlled so as to increase in accordance with the operator's request, that is, the amount of operation of the operation member 54 by the operator. Hydraulic pump 5
It means that the speed of the actuator (each cylinder) can be controlled by controlling the pump discharge flow rate from the pumps 1 and 52.

In this embodiment, the controller 1 controls the positions of the control valves 57 to 60 and 62 to 65 by controlling the positions of the control valves 57 to 60 and 62 to 65 in accordance with the operation of the operation member 54 by the operator. In addition to the control, the position control of each of the control valves 57 to 60 and 62 to 65 according to the engine speed is also performed. That is, the controller 1 adjusts the pilot oil pressure applied to each of the control valves 57 to 60 and 62 to 65 based on the electric signal from the operation member 54, and controls the proportional pressure reducing valves (pilot pressure control valves) 57a to 60a and 57b to 60b, 62a-65
a, an operation signal is output to control the operations of 62b to 65b.

Further, the controller 1 controls each of the control valves 57 to 60, 62 based on a detection signal from an engine speed sensor 71 attached to the engine 50 for driving the first hydraulic pump 51 and the second hydraulic pump 52. Proportional pressure reducing valves (pilot pressure control valves) 57a-60a, 57b-60b, 62a-
An operation signal is output to control the operations of 65a, 62b to 65b.

The proportional pressure reducing valves 57a to 60a, 57b to 60b, 62a to 6
5a, 62b to 65b are operated, whereby the pressure of the pilot hydraulic pressure supplied from the pilot pump 83 is adjusted, and the spool stroke amount (spool movement amount) of each of the control valves 57 to 60, 62 to 65 is adjusted. It has become.

The control device for a construction machine according to the present embodiment is configured as described above, and various controls are performed by the controller 1. Further, in the present embodiment, the pump flow rate control (hydraulic pressure) in the normal negative flow control is performed. In addition to the basic tilt angle control of the pumps), a plurality of hydraulic pumps 51 based on electric signals from a plurality of operating members 54 so that the engine output from the engine can be optimally distributed to each of the plurality of hydraulic pumps 51 and 52. , 52 (pump tilt angle control). Note that the engine output includes engine power, engine torque, and engine horsepower output from the engine.

Incidentally, for example, under the condition that the engine horsepower (pump horsepower) is fixed at a fixed value, the solid line A in FIG.
As shown by, when the load pressure applied to the work machine is low, the flow rate of the hydraulic oil discharged from the hydraulic pump increases (pump flow rate = horsepower (constant) / load pressure). When the flow rate increases, the pressure loss of the piping system increases and the horsepower loss due to the piping pressure loss increases, as indicated by the hatched area in FIG. 4, so that the effective power that can be supplied to the hydraulic actuator out of the engine horsepower (pump horsepower). The horsepower (effective operating oil pressure, indicated by arrow C in FIG. 4) decreases, and in FIG. 4, the solid line A changes to the solid line B, and a sufficient hydraulic oil flow rate necessary for the work cannot be obtained. Sufficient output (power) cannot be obtained.

Further, the horsepower loss due to the pipe pressure loss becomes heat and raises the temperature of the hydraulic oil, and due to this temperature rise, the viscosity of the hydraulic oil decreases and the internal leak of the hydraulic equipment increases. The efficiency of the hydraulic system (the efficiency of supplying hydraulic oil to the hydraulic actuator) is deteriorated, and the work efficiency is deteriorated without obtaining a sufficient work speed. On the other hand, in a region where the load pressure is high, and as a result, in a region where the pump flow rate is small, the horsepower loss due to the pipe pressure loss is reduced, so that the effective horsepower of the engine horsepower (pump horsepower) that can be supplied to the hydraulic actuator increases.

For this reason, in this embodiment, in consideration of the efficiency of the entire hydraulic system, the engine horsepower (pump horsepower) in the low load pressure / large flow rate region in which the horsepower loss due to the pipe pressure loss is large, in conjunction with the load pressure. Set to be smaller,
The engine horsepower (pump horsepower) is set to be large in a high load pressure / small flow rate region where horsepower loss due to pipe pressure loss is small.

When the pump horsepower is set small, the effective horsepower that can be supplied to the hydraulic actuator also decreases in proportion to this. In this case, the horsepower loss due to the pipe pressure loss causes the temperature of the hydraulic oil to rise as heat. As a result, a secondary problem such as an increase in internal leak of the hydraulic device is reduced, and the efficiency of the entire system can be improved in the balance evaluation with this.

Further, for example, in the case where control for variably setting the engine horsepower (pump horsepower) according to the load pressure applied to the work implement is performed, the engine horsepower (pump horsepower) is uniformly determined according to the load pressure regardless of the type of work. If the pump horsepower is set to be small, the work efficiency will be reduced depending on the type of work. For example, if the engine horsepower (pump horsepower) is set to be small in accordance with the load pressure applied to the work equipment at the time of boom up,
A problem that the cycle time becomes longer occurs.
For this reason, when the boom is raised, it is necessary to use the full horsepower of the engine horsepower as the pump horsepower of each hydraulic pump in the full load pressure range.

Further, in the case where the control for variably setting the horsepower distribution (the horsepower distribution of the engine horsepower) among the plurality of hydraulic pumps is performed, the horsepower is uniformly distributed regardless of the combination of the plurality of hydraulic actuators to be operated. Therefore, it cannot be said that the optimum horsepower distribution is always performed depending on the combination of the plurality of hydraulic actuators,
In some cases, the engine output cannot be used efficiently. In such a case, the distribution ratio of the horsepower distribution among the plurality of hydraulic pumps may be changed.

For this reason, in this embodiment, each operating member 5
Based on the operation signal (electric signal) from the control unit 4, each control is used properly according to the type of work. Next, the engine output, which is a feature of the construction machine control device according to the present embodiment, is output to the plurality of hydraulic pumps 51,
The pump tilt angle control (horsepower control) that is performed by distributing to each of the 52 will be described.

Here, FIG. 1 is a control block diagram for explaining pump tilt angle control by the control device of the construction machine according to the present embodiment. In the present embodiment, as shown in FIG. 1, the controller 1 includes a low power / high power determination unit 2, a digging determination unit 3, an excavation determination unit 4, a lift / turn determination unit 5, a pump tilt angle control unit. 6 is provided.

The low-power / high-power determining means 2 determines whether to use low power or high power in accordance with the work load applied to the working device 118, and determines the result of this determination based on the pump tilt described later. This is output to the digging control unit 6B and the excavation control unit 6C of the angle control unit 6. As a result, it is possible to automatically determine whether to use low power or high power in accordance with the workload. Therefore, an electric signal corresponding to the pump discharge pressure detected by the pressure sensors 72 and 73 is input to the low-power / high-power determining means 2.

The low power / high power determination means 2
Is not output to the lift / turn determination means 5 because a boom-up operation is involved in the lift / turn operation, and high power is always required in the case of the boom-up operation. Specifically, the low power / high power determination means 2 determines that one of the pump discharge pressures detected by the pressure sensors 72 and 73 is a predetermined pressure (for example, 200 kgf / cm ² ;
6MPa) or more, the pump discharge pressure is determined to be a predetermined pressure (for example, 200 kgf / cm ² ; about 19.6MPa).
a) When it is equal to or more than the above, it is determined that the power should be high, while the pump discharge pressure is a predetermined pressure (for example, about 200 kgf / c
m ² ; about 19.6 MPa) or less, it is determined that the power should be low.

Here, the working device 11 such as the boom 103 is used.
8, the pump discharge pressure changes according to the work load applied to the pump.
m ² ; about 19.6 MPa) or more to determine whether the work load on the work device 118 such as the boom 103 is large (or small).

Here, depending on whether the pump discharge pressure is equal to or higher than a predetermined pressure (for example, 200 kgf / cm ² ; about 19.6 MPa), the engine 50 should be set to either low power or high power. Is determined, a plurality of predetermined pressures are set as threshold values, and it is determined whether the pump discharge pressure is equal to or higher than one of a plurality of predetermined pressures. The output may be controlled. Further, it may be configured to determine whether or not both of the pump discharge pressures detected by the pressure sensors 72 and 73 are equal to or higher than a predetermined pressure (for example, 200 kgf / cm ² ; about 19.6 MPa). The average value of the pump discharge pressure detected by the sensors 72 and 73 is a predetermined pressure (for example, 200 kgf / cm ² ; about 19.6MPa).
a) You may comprise as what determines whether it is above. In addition, the magnitude of the predetermined pressure is determined based on whether the power needs to be increased in consideration of the feeling (operation speed) of the operator. The digging determination means 3 determines whether or not a digging operation is performed based on electric signals from the stick operation member 54b and the bucket operation member 54c, and determines the result of this determination by the pump tilt angle control means 6 described later. This is output to the digging control section 6B.

In the digging determination means 3, the stick-in operation is performed based on the electric signals from the stick operating member 54b and the bucket operating member 54c, and the bucket operating member 54c is operated. In this case, it is determined that the operation is a digging operation. Here, the digging work is a work in which the stick-in operation and the bucket operation are performed simultaneously.
For example, there are excavation work performed with high power (heavy excavation work), and leveling work and excavation work performed with low power (light excavation work).

The excavation determining means 4 determines whether or not the operation is an excavation operation based on the electric signals from the stick operating member 54b and the turning operating member 54d. This is output to the excavation control unit 6C of the tilt angle control means 6. In the excavation determining means 4, the stick-in operation is performed based on the electric signals from the stick operation member 54b and the turning operation member 54d, and the turning operation member 54d is operated. Is determined to be an excavation work.

Here, the excavation work is a work in which the stick-in operation and the turning operation are performed simultaneously. The excavation work includes a work performed at low power and a work performed at high power. Note that low power refers to a case where the load pressure applied to the stick driving hydraulic cylinder 106 is low, and thus the pump discharge pressure is lower than a predetermined value.
On the other hand, high power refers to a case where the load pressure applied to the stick driving hydraulic cylinder 106 is high, and therefore the pump discharge pressure becomes higher than a predetermined value.

For example, as an operation performed at low power, there is a diagonal smoothing operation in which a stick operation and a turning operation are interlocked, and the turning operation is an operation pattern in which the full operation is not performed. Here, the diagonal leveling operation is a leveling operation in which the bucket blade is lightly inserted into the ground, and the operation amount of the operation member is reduced without rotating the upper rotating body 102 and pressing the work implement against the side wall. This is performed while the upper swing body 102 is swung accordingly.
This oblique leveling work has a small reaction force and therefore has little rattling of the fuselage, so it can be used in both the X-axis direction and the Y-axis direction.
Can be operated in the modulation position. In this regard, it can be distinguished from a side wall excavation operation.

[0109] As a high power operation, there is a side wall scraping operation (side wall excavation operation, side wall cutting operation) in which a stick-in operation is performed while a work machine is pressed against a side wall by a turning operation. Here, in the side wall scraping operation, the turning operation member 54d is fixed in a fully operated state (in this case, since the working machine hits the side wall, the upper turning body 102 does not actually turn, but It is only pressed), and is performed by performing stick-in by a modulation operation.
In this operation, the turning operation member 54d and the stick operation member 54b are constituted by a single operation lever, and when the operation lever is operated in the X-axis direction, the operation becomes a turning operation, and when the operation lever is operated in the Y-axis direction, the operation is performed. Under these conditions, the operation in the X-axis direction and the operation in the Y-axis direction are performed due to the stick operation. However, it is difficult to fix it at the modulation position.

The lift / turn control means 5 determines whether or not a lift / turn operation is to be performed based on electric signals from the boom operation member 54a and the turn operation member 54d. This is output to the lift / turn controller 6D of the tilt angle control means 6. This lift /
In the turning determination means 5, a boom-up operation is performed based on electric signals from the boom operating member 54a and the turning operation member 54d, and the turning operation member 54
When d is operated, it is determined that the operation is a lift / turn operation.

Here, the lift / turn operation is an operation in which the boom-up operation and the turn operation are performed simultaneously.
For example, it is performed as one operation in a loading operation for loading earth and sand on a dump truck or the like. The pump tilt angle control means 6 includes a basic tilt angle control unit 6A, a digging control unit 6B, an excavation control unit 6C,
And a turning control section 6D.
1 and 52 to output an operation signal.

In the present embodiment, the pump tilt angles of the hydraulic pumps 51 and 52 are basically set by the basic tilt angle control unit 6A. However, during digging, excursion, and lift / turn, the engine is tilted. The pump tilt angles of the hydraulic pumps 51 and 52 are controlled so that the engine output from the engine 50 is optimally distributed. Of these, the basic tilt angle control unit 6A includes pressure sensors 72, 73, 74,
The basic pump tilt angle control of the hydraulic pumps 51 and 52 is performed based on the detection information from 75.

Here, the negative by the basic tilt angle control unit 6A
For pump tilt angle control in active flow control
explain about. That is, the basic tilt angle control unit 6 </ b> A
The operating oil pressure (negative) detected by the force sensors 74 and 75
Con pressure) P_N1, P_N2And read the negative control pressure P_NAnd the key
Flow rate Q_NMap as shown in Fig. 5
Negative pressure P_N1, P _N2Request corresponding to
Flow Q_N1, Q_N2(Specifically, the required flow rate Q_N1, Q_N2Equivalent to
Pump tilt angle V_N1, V_N2Began to set)
I have. The required flow rate refers to the negative flow control.
Means the flow rate required by the tool. In FIG.
Gakon pressure P_N1Required flow Q corresponding to_N1(Specifically, request
Flow Q_N1, The pump tilt angle V corresponding to_N1) Only shows
You.

On the other hand, the basic tilt angle control section 6A outputs the pump discharge pressures P _P1 and P P detected by the pressure sensors 72 and 73.
Loading _P2, allowable flow Q _P1, Q from a map as shown the pump discharge pressure P _P and allowable flow Q _P in FIG. 6 related, corresponding to the pump discharge pressure P _P1, P _P2 read
_P2 (specifically allowable flow Q _P1, the pump tilting angle corresponding to Q _P2 V _P1, V _P2) is adapted to set a. In addition,
The allowable flow rates are the first hydraulic pump 51 and the second hydraulic pump 5
2 means the pump discharge flow rate according to the allowable horsepower of the engine 50 that drives the engine 2. Also shows allowable flow Q _P1 only (pump tilting angle V _P1 specifically corresponding to allowable flow Q _P1) corresponding to the pump discharge pressure P _P1 in FIG.

Then, the basic tilt angle control section 6A performs the above-described operation.
Required flow Q_N1, Q_N2And allowable flow rate Q_P1, Q_P2And compare
The smaller pump flow rate (required flow rate Q_N1, Q_N2Or permissible flow
Quantity Q _P1, Q_P2) So that the pump tilt angle (pump tilt)
Angle V_N1, V_N2Or pump tilt angle V_P1, V_P2),
This is used as the tilt angle control signal for the first hydraulic pump 51 and the
It outputs to the two hydraulic pumps 52.

Next, the basic operation of the pump tilt angle control in the negative flow control by the basic tilt angle control section 6A will be described with reference to the flowchart of FIG. That is, first, in step S10, the negative control pressures P _N1 and P _N2 are read, and in step S20, the pump discharge pressures P _P1 and P _P2 are read.

Next, in step S30, in step S10
Loaded negative control pressure P_N1, P_N2Required flow rate corresponding to
Q_N1, Q_N2Is calculated from the map of FIG.
Pump discharge pressure read in step S20 in step 40
P_P1, P_P2Flow rate Q corresponding to_P1, Q_P2To the map in FIG.
Calculated from the Then, in step S50, the required flow rate Q
_N1, Q_N2Is the allowable flow rate Q_P1, Q_P2Is smaller than
As a result of this determination, the required flow rate Q_N1, Q_N2Is the allowable flow rate
Q_P1, Q _P2If it is determined to be smaller than
Proceeding to S60, the required flow rate Q_N1, Q _N2As the pump flow rate
Set and return. Thereby, the first hydraulic pump 5
The tilt angle of the first and second hydraulic pumps 52 is equal to the required flow rate Q._N1, Q
_N2Is set so as to have a tilt angle corresponding to.

On the other hand, if it is determined that the required flow rates Q _N1 , Q _N2 are equal to or greater than the allowable flow rates Q _P1 , Q _P2 , the process proceeds to step S.
The routine proceeds to 70, where the allowable flow rates Q _P1 and Q _P2 are set as pump flow rates, and the routine returns. Thereby, the first hydraulic pump 51
And the tilt angle of the second hydraulic pump 52 is set to the allowable flow rate Q _P1 , Q _P2
Is set so as to have a tilt angle corresponding to. The digging control unit 6B provides the stick driving hydraulic cylinder 106 and the bucket driving hydraulic cylinder 10 when the digging determining means 3 determines that digging is being performed, that is, when it is determined that the stick-in operation and the bucket operation are being performed simultaneously.
The distribution of the engine output to the hydraulic pumps 51 and 52 is set so that the hydraulic oil is supplied to the hydraulic pumps 51 and 52 without excess and deficiency. 52 is to control the pump tilt angle. Note that the pump tilt angle control of each of the hydraulic pumps 51 and 52 is the same as that of the above-described basic tilt angle control unit 6A.
As a result, the engine output is reduced by the hydraulic pumps 51 and 52.
And the first hydraulic pump 51
And the pump discharge flow rate of each of the second hydraulic pumps 52 becomes a pump discharge flow rate sufficient to simultaneously operate the stick 104 and the bucket 108, and the fuel efficiency is improved by efficiently using the engine output. Can be.

Specifically, in the digging control section 6B,
Based on the determination result from the low power / high power determination means 2, setting of a distribution ratio (distribution horsepower) for distributing the engine output from the engine 50 to each of the hydraulic pumps 51 and 52, as described later, , 52 (the upper limit horsepower). Here, when high power is to be set, the upper limit horsepower is the maximum horsepower of the engine (for example, about 140 PS; about 102.20 kW).
Is set to On the other hand, if low power is to be set, the upper limit horsepower is a predetermined horsepower less than the maximum horsepower of the engine (for example, about 1 horsepower).
20PS; about 87.60 kW).

The digging controller 6B controls each hydraulic pump 5 based on an electric signal corresponding to the operation amount of the stick operating member 54b and the bucket operating member 54c.
The distribution of the engine output between the engine outputs 1 and 52 is set. Here, Table 1 below shows an example of the distribution ratio of the engine output and an example of the setting of the upper limit horsepower. This Table 1
5 shows the distribution ratio of the engine output when each operation member 54 is fully operated. Table 1 also shows the pump horsepower according to the distribution ratio of the engine output. The first hydraulic pump 51 mainly supplies hydraulic oil to the bucket driving hydraulic cylinder 107, and the second hydraulic pump 52 mainly supplies hydraulic oil to the stick driving hydraulic cylinder 106.

[0121]

[Table 1]

As shown in Table 1, when low power is to be set, the engine output from the engine 50 is
A minimum bucket request ratio (for example, about 30%) is allocated to supply the minimum required engine output to drive the bucket 108 to the first hydraulic pump 51, and the second hydraulic pump 52
In order to provide the engine output necessary to operate the stick 104 at a sufficient operating speed, the stick request ratio (for example, about 70%) larger than the bucket request ratio is allocated.

That is, when low power is to be set, the upper limit of the total horsepower distributed to each of the hydraulic pumps 51 and 52 is equal to the low power upper horsepower (for example, about 120 PS; about 87.6 k).
W). And this engine horsepower is the first
The bucket drive required horsepower (for example, about 36 PS; about 26.28 kW) is distributed to supply the hydraulic pump 51 with the minimum engine horsepower required to drive the bucket 108, and the stick 104 is sufficiently operated by the second hydraulic pump 52. A higher stick horsepower (eg, about 84 PS; about 61.32 kW) than the bucket horsepower will be allocated to provide the engine horsepower required to operate at speed.

On the other hand, when high power is to be provided, the engine output from the engine 50 is required to operate the bucket 108 at a sufficient operating speed with the first hydraulic pump 51 as shown in Table 1 above. A bucket request ratio (for example, about 40%) is allocated to supply the engine output, and is larger than the bucket request ratio to supply the second hydraulic pump 52 with the engine output necessary to operate the stick 104 at a sufficient operation speed. The stick request ratio (for example, about 60%) is allocated.

That is, when high power is to be set, the upper limit of the total horsepower distributed to each of the hydraulic pumps 51 and 52 is equal to the high power upper horsepower (the maximum horsepower of the engine;
0PS; about 102.20 kW). And
This engine horsepower is supplied to the first hydraulic pump 51 by the bucket 1
08 to provide the engine horsepower required to operate the 08 at sufficient operating speed (eg, about 56 horsepower).
PS; about 40.88 kW) distributed, the second hydraulic pump 5
2 to provide the engine horsepower required to operate the stick 104 at a sufficient operating speed.
S; about 61.32 kW).

Here, the engine horsepower distributed to the first hydraulic pump 51 is set to a predetermined horsepower (for example, about 56 PS;
The reason why the pressure is set to 0.88 kW is that the first hydraulic pump 51 that supplies hydraulic oil to the bucket driving hydraulic cylinder 107 to drive the bucket 108 is driven with a larger engine horsepower (high power) than at low power. This is to secure the operation speed of the bucket 108 and improve the work efficiency.

As described above, in both the low-power and high-power cases, the reason why the engine output is largely distributed to the second hydraulic pump 52 is that the engine output is supplied from the second hydraulic pump 52 to the stick driving hydraulic cylinder 106. This is because, by increasing the flow rate of the operating oil to be performed and increasing the operating speed of the stick 104 that most affects the working efficiency, the working efficiency is improved as a whole.

Further, as described above, in the control for variably setting the engine horsepower (pump horsepower) according to the load pressure applied to the work machine, the total horsepower of the plurality of hydraulic pumps 51 and 52 is set to be small. Even in such a case, by performing control capable of variably setting the horsepower distribution, a large amount of horsepower is distributed to the hydraulic actuator (here, the hydraulic cylinder for stick drive) to be preferentially operated (for example, when high horsepower is set). By distributing the same horsepower as above), it is possible to improve the working efficiency of the hydraulic actuator that is to be preferentially operated.

Further, as described above, the control for variably setting the engine horsepower (pump horsepower) in accordance with the load pressure applied to the work machine and the control for variably setting the horsepower distribution among the plurality of hydraulic pumps are described below. By combining based on operation signals (electric signals) from the respective operation members, the efficiency (including productivity / heat loss) of the entire system can be improved.

The distribution ratio of engine output (distribution horsepower) when each operation member 54 is not fully operated is the distribution ratio of engine output (distribution horsepower) when each operation member 54 is fully operated. ) May be set by correcting according to the operation amount of each operation member 54. When the excavation determining means 4 determines that the excavation is being performed, that is, when the stick-in operation and the turning operation are performed simultaneously, the excavation control unit 6C controls the stick driving hydraulic cylinder 106 and the turning motor. The distribution of the engine output to the hydraulic pumps 51 and 52 is set so that the hydraulic oil is supplied to the hydraulic pumps 51 and 52 without excess and deficiency. 52 is to control the pump tilt angle. Note that the pump tilt angle control of each of the hydraulic pumps 51 and 52 is the same as that of the above-described basic tilt angle control unit 6A.

As a result, the engine output can be optimally distributed to both the hydraulic pumps 51 and 52, and the pump discharge flow rates of the first hydraulic pump 51 and the second hydraulic pump 52 are determined by the operation of the stick 104 and the upper part. Revolving body 10
In addition to a pump discharge flow rate sufficient to simultaneously perform the two turns, fuel efficiency can be improved by efficiently utilizing the engine output.

More specifically, the excavation control unit 6
In C, based on the determination result from the low power / high power determination means 2, setting of a distribution ratio (distribution horsepower) for distributing the engine output from the engine 50 to each of the hydraulic pumps 51 and 52, as described later, The upper limit output (upper limit horsepower) of the total horsepower of the hydraulic pumps 51 and 52 is set. Note that the upper limit output (upper limit horsepower) of the total horsepower corresponds to the full output (full horsepower) of the engine output (engine horsepower).

Here, if high power is to be set, the upper limit horsepower is set to the maximum horsepower of the engine (for example, about 140 PS; about 102.20 kW). On the other hand, if low power is to be set, the upper limit horsepower is set to a predetermined horsepower (for example, about 120 PS; about 87.60 kW) that is equal to or less than the maximum horsepower of the engine. In the excavation control unit 6C,
Stick operation member 54b and turning operation member 54d
Each hydraulic pump 5 based on an electric signal corresponding to the operation amount of
The engine output distribution is set for the engine outputs 1 and 52.

Here, Table 2 below shows an example of the distribution ratio of the engine output and an example of the setting of the upper limit horsepower. Table 2 shows the distribution ratio of the engine output when each operation member 54 is fully operated. Table 2 also shows the pump horsepower according to the distribution ratio of the engine output. The first hydraulic pump 51 mainly supplies hydraulic oil to the stick driving hydraulic cylinder 106, and the second hydraulic pump 52 mainly supplies hydraulic oil to the turning motor 110.

[0135]

[Table 2]

As shown in Table 2, in the case of, for example, a leveling operation, the load pressure of the stick driving hydraulic cylinder 106 is low, and therefore the pump discharge pressure is lower than a predetermined value. Is required to supply the first hydraulic pump 51 with the engine output necessary to operate the stick 104 at a sufficient operating speed (for example, about 70%).
The minimum required rotation rate (for example, about 30%) is distributed to supply the second hydraulic pump 52 with the minimum engine output required to rotate the upper rotating body 102.

At this time, the upper limit of the total horsepower distributed to each of the hydraulic pumps 51 and 52 is set to the low power upper limit horsepower (for example, about 120 PS; about 87.60 kW). The engine horsepower is distributed to the first hydraulic pump 51 to supply the engine horsepower required to operate the stick 104 at a sufficient operating speed (for example, about 84 PS; about 61.32 kW). The minimum required horsepower for turning (for example, about 36 PS; about 26.28 kW) is distributed to supply the engine hydraulic power required to turn the upper turning body 102 to the two hydraulic pumps 52.

On the other hand, in the case of the side wall scraping operation (sidewall excavation), the load pressure of the stick driving hydraulic cylinder 106 is high, and therefore, the pump discharge pressure is larger than a predetermined value. As shown in
A stick request ratio (for example, about 75%) is allocated to supply the first hydraulic pump 51 with an engine output required to operate the stick 104 at a sufficient operating speed, and the upper revolving unit 102 is swung to the second hydraulic pump 52. The minimum required turn ratio (for example, about 25%) is allocated to supply the minimum required engine output to perform the turning.

At this time, the upper limit value of the total horsepower distributed to each of the hydraulic pumps 51 and 52 is a high power upper horsepower (maximum horsepower of the engine; for example, about 140 PS; about 102.20 k).
W). And this engine horsepower is the first
The required stick horsepower (eg, about 104 PS; about 75.92) to provide the hydraulic pump 51 with the engine horsepower necessary to operate the stick 104 at a sufficient operating speed.
kW) distributed to the second hydraulic pump 52 and
2 to provide the minimum engine horsepower required to turn the vehicle 2 (eg, about 36 PS; about 26.2).
8 kW).

Here, the engine horsepower distributed to the first hydraulic pump 51 is set to a predetermined horsepower (for example, about 104 PS; about 75.92 kW) because the stick driving hydraulic cylinder 106 is used to operate the stick 104.
By operating the first hydraulic pump 51 that supplies the operating oil to the engine with a larger engine horsepower (high power) than at the time of low power, the operating speed of the stick 104 is secured and the working efficiency is improved.

As described above, in both low power and high power cases, the engine output is largely distributed to the first hydraulic pump 51 because the engine power is supplied from the first hydraulic pump 51 to the stick driving hydraulic cylinder 106. Stick 1 that has the greatest effect on work efficiency by increasing the flow rate of hydraulic oil
This is because, by improving the operation speed of No. 04, the work efficiency is improved as a whole.

As described above, in the control for variably setting the engine horsepower (pump horsepower) in accordance with the load pressure applied to the work implement, the total horsepower of the plurality of hydraulic pumps 51 and 52 is set to be small. Even in the case where the power is distributed, a control can be performed to variably set the horsepower distribution, thereby distributing a large amount of horsepower to a hydraulic actuator (in this case, a stick driving hydraulic cylinder) to be preferentially operated, thereby giving priority to The working efficiency of the hydraulic actuator that is desired to be actuated can be improved.

As described above, the control for variably setting the engine horsepower (pump horsepower) in accordance with the load pressure applied to the work machine and the control for variably setting the horsepower distribution among the plurality of hydraulic pumps are described below. By combining based on operation signals (electric signals) from the respective operation members, the efficiency (including productivity / heat loss) of the entire system can be improved.

The distribution ratio (distribution horsepower) of the engine output when each operation member 54 is not fully operated is the distribution ratio (distribution horsepower) of the engine output when each operation member 54 is fully operated. ) May be set by correcting according to the operation amount of each operation member 54. The lift / turn control unit 6D provides the boom operation member 54a and the turn operation when the lift / turn determination unit 5 determines that the lift / turn operation is performed, that is, when the boom-up operation and the turn operation are performed simultaneously. Based on the electric signal corresponding to the operation amount of the member 54d, the distribution of the engine output to the hydraulic pumps 51 and 52 is adjusted so that the hydraulic oil is supplied to the boom drive hydraulic cylinder 105 and the swing motor 110 without excess or deficiency. The pump tilt angle of each of the hydraulic pumps 51 and 52 is controlled so as to be set and such an engine output distribution. Note that the pump tilt angle control of each of the hydraulic pumps 51 and 52 is the same as that of the above-described basic tilt angle control unit 6A.

Thus, the engine output can be optimally distributed to both of the hydraulic pumps 51 and 52, and the pump discharge flow rate of each of the first hydraulic pump 51 and the second hydraulic pump 52 is controlled by the operation of the boom 103 and the upper part. The pump discharge flow rate is sufficient to simultaneously rotate the revolving superstructure 102, and fuel efficiency can be improved by efficiently utilizing the engine output.

More specifically, the lift / turn controller 6D sets a distribution ratio (distribution horsepower) for distributing the engine output from the engine 50 to the hydraulic pumps 51 and 52, as described later, , 52 are set to the upper limit output (upper limit horsepower) of the total horsepower. Here, the upper limit horsepower is the maximum horsepower of the engine (for example, about 140
PS; about 102.20 kW).

The lift / turn control section 6D uses the hydraulic pumps 51, 52 based on electric signals corresponding to the operation amounts of the boom operation member 54a and the turn operation member 54d.
To set the engine power distribution to the engine. Here, Table 3 below shows an example of the distribution ratio of the engine output. Table 3 shows the distribution ratio of the engine output when each operation member 54 is fully operated. In addition,
Table 3 also shows the engine horsepower according to the distribution ratio of the engine output. The first hydraulic pump 51 mainly supplies hydraulic oil to the boom drive hydraulic cylinder 105,
The second hydraulic pump 52 mainly supplies hydraulic oil to the swing motor 110.

[0148]

[Table 3]

As shown in Table 3, the engine output from the engine 50 is a boom request ratio (for example, about 1%) to supply the first hydraulic pump 51 with the engine output necessary to operate the boom 103 at a sufficient operating speed. 70%), and a minimum required swing ratio (for example, about 30%) is allocated to supply the second hydraulic pump 52 with the minimum engine output required to swing the upper swing body 102.

At this time, the upper limit of the total horsepower distributed to each of the hydraulic pumps 51 and 52 is equal to the upper limit horsepower (for example, about 140 P).
S; about 102.20 kW). This is because a boom-up operation always requires high power. Then, the engine horsepower is distributed to the first hydraulic pump 51 to supply the engine horsepower necessary to operate the boom 103 at a sufficient operating speed (for example, about 98 PS; about 71.54 kW). The minimum required horsepower for turning (for example, about 42 PS; about 30.66 kW) is distributed in order to supply the minimum required engine horsepower for turning the upper turning body 102 to the second hydraulic pump 52.

The engine output is controlled by the first hydraulic pump 51.
The reason is that the flow rate of the hydraulic oil supplied from the first hydraulic pump 51 to the boom driving hydraulic cylinder 105 is increased to improve the operation speed of the boom 103, thereby improving work efficiency. It is. The distribution ratio (distribution horsepower) of the engine output when each operation member 54 is not fully operated is the distribution ratio (distribution horsepower) of the engine output when each operation member 54 is fully operated. What is necessary is just to set by correcting according to the operation amount of each operation member 54.

The control device for a construction machine according to this embodiment is configured as described above, and the main routine according to the present control operates according to the procedure shown in the flowchart of FIG. First, in step S10, an electric signal from each operation member 54 is read, and the process proceeds to step S20. Step S
At 20, the digging determination means 3, the excavation determination means 4, and the lift / turn determination means 5 determine whether or not the stick-in operation has been performed based on the electric signal from the stick operation member 54b. As a result, if it is determined that the sticking-in operation has been performed by the digging determining means 3 and the excavation determining means 4, the process proceeds to step S30.

In the step S30, the low power / high power
The power determination means 2 detects the detection information from the pressure sensors 72 and 73.
(Corresponding to the pump discharge pressure), and
Proceed to step S40, and in step S40, low power / high power
The determination means 2 is detected by the pressure sensors 72 and 73
Pump discharge pressure is a predetermined pressure (for example, 200 kgf / c
m ^TwoAbout 19.6 MPa) or more.

If it is determined that the pump discharge pressure is equal to or higher than the predetermined pressure (for example, 200 kgf / cm ² ; about 19.6 MPa), the process proceeds to step S50, and the digging control of the pump tilt angle control means 6 is performed. Unit 6B and the excavation control unit 6C
The upper limit of the engine output distributed to the hydraulic pumps is set to a high power upper limit horsepower (for example, about 140 PS; about 102.20 kW), and the predetermined horsepower is optimally distributed to the hydraulic pumps 51 and 52 to perform the pump tilt angle control. In order to perform this, an optimal power distribution pump tilt angle control routine at the time of high power is executed. The optimum power distribution pump tilt angle control routine at the time of high power will be described later.

On the other hand, in step S40, the pump discharge pressure
Predetermined pressure (for example, 200 kgf / cm ^TwoAbout 19.6MP
a) If it is determined that it is not the above, the process proceeds to step S60.
And the digging control unit 6B of the pump tilt angle control means 6.
And the excavation control unit 6C
The lower limit of the engine output allocated to
-Maximum horsepower (for example, about 120 PS; about 87.60 kW)
And the predetermined horsepower is applied to each of the hydraulic pumps 51 and 52.
In order to control the pump tilt angle with appropriate power distribution,
Optimum power distribution at power pump tilt angle control routine
Execute. The optimal power distribution pump at low power
The tilt angle control routine will be described later.

If it is determined in step S20 that the stick-in operation has not been performed, the flow advances to step S70 to execute an optimal power distribution pump tilt angle control routine for lift / turn. The optimal power distribution pump tilt angle control routine during lift / turn will be described later. Next, in the control device of the construction machine according to the present embodiment, the optimal power distribution pump tilt angle control routine (step S50 in FIG. 8) at the time of high power operates according to the procedure shown in the flowchart in FIG.

That is, in step A10, the digging judging means 3 and the excavation judging means 4 judge whether or not the bucket operation has been performed based on the electric signal from the bucket operating member 54c. As a result of the judgment,
If the digging determination means 3 determines that the bucket operation has been performed, it means that the stick-in operation and the bucket operation have been performed simultaneously. Since this is considered to be a digging operation, the process proceeds to step A50, and the pump tilt is performed. The digging control unit 6B of the turning angle control means 6 controls the hydraulic pumps 51 and 52 based on the electric signals from the stick operating member 54b and the bucket operating member 54c so that the engine output from the engine 50 is optimally distributed. The distribution of engine power to the engine.

Here, the digging control unit 6B distributes the engine output to the first hydraulic pump 51 by the bucket request ratio (for example, about 40%) and distributes the engine output to the second hydraulic pump 52 by the stick request ratio (for example, about 60%). . That is, the digging control unit 6B sends the engine horsepower whose upper limit value is set to the high power upper limit horsepower (for example, about 140 PS; about 102.20 kW) to the first hydraulic pump 51 for the bucket required horsepower (for example, about 56 PS; 88 kW) to the second hydraulic pump 52 for the required stick horsepower (for example, about 84
PS; about 61.32 kW).

Then, the pump tilt angles of the hydraulic pumps 51 and 52 are controlled so as to achieve such engine output distribution, and the routine returns. On the other hand, if the excavation determination means 4 determines in step A10 that the bucket operation has not been performed, the process proceeds to step A20, where the excavation determination means 4 further turns the turning operation member 54d.
It is determined whether or not the turning operation has been performed based on the electric signal from.

As a result of this determination, when the excavation determination means 4 determines that the turning operation has been performed, it means that the stick-in operation and the turning operation have been performed simultaneously, which is an excavation operation. Therefore, the process of step A30 is performed. Next, in step A30, the excavation control unit 6C operates the hydraulic pumps 51 so that the engine output from the engine 50 is optimally distributed based on the electric signals from the stick operation member 54b and the turning operation member 54d. , 52 are set.

Here, the excavation control unit 6C
Distributes the engine output to the first hydraulic pump 51 with a stick request ratio (for example, about 75%), and
To the minimum required turn ratio (for example, about 25%). That is, the excavation control unit 6C sets the upper limit value to the high power upper limit horsepower (for example, about 140 PS; about 102.20 k
W), the engine horsepower set in the first hydraulic pump 51
The required stick horsepower (for example, about 104 PS, about 75.
92 kW) and the minimum turning required horsepower (for example, about 36 PS; about 26.28 kW) to the second hydraulic pump 52.

Then, the pump tilt angles of the hydraulic pumps 51 and 52 are controlled so as to achieve such an engine output distribution, and the routine returns. By the way, if the excavation determination means 4 determines in step A20 that the turning operation has not been performed, it is considered that the operation is not an excavation operation, and therefore the pump tilt angle control during the excavation is not performed. And return.

Next, the control device of the construction machine according to the present embodiment performs the optimum power distribution pump tilt angle control routine (step S60 in FIG. 8) at the time of low power as shown in the flowchart of FIG. Operate. That is,
In step B10, the digging determination means 3 and the excavation determination means 4 determine whether or not a bucket operation has been performed based on an electric signal from the bucket operation member 54c.

As a result of the determination, when the digging determination means 3 determines that the bucket operation has been performed, it means that the stick-in operation and the bucket operation have been performed simultaneously, and this is considered to be a digging operation. ,
Proceeding to step B50, the digging control unit 6B of the pump tilt angle control unit 6 determines whether the digging control unit 6B is operated based on the electric signals from the stick operation member 54b and the bucket operation member 54c.
The distribution of the engine output to each of the hydraulic pumps 51 and 52 is set so that the engine output from the engine 50 is optimally distributed.

Here, the digging control unit 6B distributes the engine output to the first hydraulic pump 51 with the minimum bucket request ratio (eg, about 30%), and distributes the engine output to the second hydraulic pump 52 with the stick request ratio (eg, about 70%). I do. That is,
The digging control unit 6B sends the engine horsepower of which the upper limit is set to the low power upper limit horsepower (for example, about 120 PS; about 87.60 kW) to the first hydraulic pump 51 for the bucket minimum required horsepower (for example, about 36 PS; about 26.28 kW). ) And distribute to the second hydraulic pump 52 the required stick horsepower (for example, about 84 PS; about 61.32 kW).

Then, the pump tilt angles of the hydraulic pumps 51 and 52 are controlled so as to achieve such engine output distribution, and the routine returns. On the other hand, if the excavation determination means 4 determines in step B10 that the bucket operation has not been performed, the process proceeds to step B20, where the excavation determination means 4 further turns the turning operation member 54d.
It is determined whether or not the turning operation has been performed based on the electric signal from.

As a result of this determination, when the excavation determining means 4 determines that the turning operation has been performed, it means that the stick-in operation and the turning operation have been performed simultaneously, which is an excavation operation. Therefore, the process of step B30 is performed. Next, in step B30, the excavation control unit 6C of the pump tilt angle control means 6 optimally distributes the engine output from the engine 50 based on the electric signals from the stick operation member 54b and the turning operation member 54d. The distribution of the engine output to each of the hydraulic pumps 51 and 52 is set so as to be performed.

Here, the excavation control unit 6C
Distributes the engine output to the first hydraulic pump 51 to a stick request ratio (for example, about 70%) and the second hydraulic pump 52
To the minimum required turn ratio (for example, about 30%). That is, the excavation control unit 6C sets the upper limit value to the low power upper limit horsepower (for example, about 120 PS; about 87.60 k
W), the engine horsepower set in the first hydraulic pump 51
The required stick horsepower (for example, about 84PS; about 61.3)
2 kW) and the minimum turning required horsepower (for example, about 36 PS; about 26.28 kW) to the second hydraulic pump 52.

Then, the pump tilt angles of the hydraulic pumps 51 and 52 are controlled such that the engine output is distributed, and the process returns. By the way, in step B20, when the excavation determination means 4 determines that the turning operation is not performed, it is considered that the operation is not the excavation operation, and therefore the pump tilt angle control at the time of the excavation is not performed. And return.

Next, the control device of the construction machine according to the present embodiment performs the optimum power distribution pump tilt angle control routine (step S70 in FIG. 8) at the time of lift / turn.
It operates as shown in the flowchart of FIG. That is, in step C10, the lift / turn determination unit 5 determines whether a boom-up operation has been performed based on the electric signal from the boom operation member 54a, and as a result of this determination, it is determined that the boom-up has been performed. If so, the process proceeds to step C20, and it is determined whether or not the turning operation has been performed based on the electric signal from the turning operation member 54d.

As a result of this determination, when it is determined that the turning operation has been performed, it means that the boom-up operation and the turning operation have been performed simultaneously, and it is considered that this is a lift / turn operation. Then, the lift / turn control unit 6C of the pump tilt angle control means 6 controls the engine output from the engine 50 to be optimally distributed based on the electric signals from the boom operation member 54a and the turn operation member 54d. Of the engine output to each of the hydraulic pumps 51 and 52 is set.

Here, the lift / turn control section 6C distributes the engine output to the first hydraulic pump 51 for the boom request rate (for example, about 70%), and distributes the engine output to the second hydraulic pump 52 for the minimum turn request rate (for example, about 30%). ) To distribute. That is, the lift / turn controller 6C sets the upper limit to the upper limit horsepower (for example, about 14
0 PS; about 102.20 kW, the engine horsepower set to the first hydraulic pump 51 for the required boom horsepower (for example, about 9
8PS; about 71.54 kW)
The minimum required horsepower for turning (for example, about 42 PS; about 30.6
6 kW).

Then, the pump tilt angles of the hydraulic pumps 51 and 52 are controlled such that the engine output is distributed, and the process returns. When the lift / turn determination unit 5 determines that the boom-up operation is not performed in step C10, and when the lift / turn determination unit 5 determines that the rotation operation is not performed in step C20, It is considered that the operation is not a swing / turn operation, so the routine returns without performing the pump tilt angle control at the time of lift / turn.

Therefore, according to the construction machine control device of this embodiment, the engine output is
1 and 52, the hydraulic pumps 51 and 52
In this case, it is possible to prevent the engine speed from being reduced due to insufficient pump output due to insufficient engine output, and to improve the working efficiency.

In addition, the engine output is supplied to the hydraulic pumps 51 and 52 more than necessary, which causes an increase in pipe pressure loss to generate horsepower loss, or an internal leak due to a rise in hydraulic oil temperature due to this. Another advantage is that inefficiencies in the overall system can be improved, such as increasing and consuming extra horsepower for cooling. In the above-described embodiment, two hydraulic pumps are provided, and the engine output is distributed to these hydraulic pumps. However, by providing two or more hydraulic pumps, a work load applied to each hydraulic actuator is provided. , The engine output may be distributed to each of these hydraulic pumps.

In the above-described embodiment, the hydraulic pump 5
Although the swash plate rotary piston pumps 1 and 52 are configured as variable displacement pumps that can control the pump discharge flow rate by an operation signal from the controller 1, for example, a swash shaft type piston pump or a variable discharge amount type It may be a vane pump or the like. In the above-described embodiment, the digging control unit 6B and the excavation control unit 6C include:
The upper limit value of the engine output distributed to each of the hydraulic pumps 51 and 52 is changed between the low power state and the high power state according to the work load applied to the work unit 118 based on the determination result of the low power / high power determination means 2. The lift /
Also in the turning control unit 6D, the engine distributed to each of the hydraulic pumps 51 and 52 at the time of low power and at the time of high power according to the work load applied to the work device 118 based on the determination result of the low power / high power determination means 2. The upper limit of the output may be changed.

In the above-described embodiment, the digging control unit 6B and the excavation control unit 6C determine whether the low power or high power The engine output distributed to the hydraulic pumps 51 and 52 is controlled at the time of high power and at the time of high power.
In the above, the engine output distributed to the hydraulic pumps 51 and 52 at the time of low power and at the time of high power is controlled according to the work load applied to the work device 118 based on the determination result of the low power / high power determination means 2. May be.

In the above-described embodiment, the case where the present invention is applied to the control device of the construction machine which performs the negative flow control is described. However, the present invention is applied to the control device of the construction machine which performs the positive flow control. You may.

[0179]

As described above in detail, according to the control apparatus for a construction machine according to the present invention, since the engine output is optimally distributed to each hydraulic pump, a sufficient engine power for the hydraulic pump can be obtained. There is an advantage that it is possible to prevent the output from being supplied and the pump output from becoming insufficient and the working speed from being reduced, thereby improving the working efficiency. Also, it is possible to prevent the engine output from being supplied to the hydraulic pump more than necessary, to cause an increase in piping pressure loss to generate a horsepower loss, and to increase an internal leak due to a rise in hydraulic oil temperature due to this, Another advantage is that inefficiencies in the overall system, such as consuming extra horsepower for cooling, can be reduced.

[Brief description of the drawings]

FIG. 1 is a control block diagram for explaining pump tilt angle control by optimal power distribution in a control device for a construction machine according to one embodiment of the present invention.

FIG. 2 is an overall configuration diagram of a control device for a construction machine according to an embodiment of the present invention.

FIG. 3 is a schematic diagram for explaining a control valve of the control device for the construction machine according to the embodiment of the present invention.

FIG. 4 is a diagram for explaining a horsepower loss due to a pipe pressure loss in a general construction machine and an effective horsepower that can be supplied to a hydraulic actuator.

FIG. 5 is a diagram illustrating a relationship between a required flow rate of negative flow control and a negative control pressure in the control device for a construction machine according to one embodiment of the present invention.

FIG. 6 is a diagram illustrating a relationship between an allowable flow rate of negative flow control and a pump discharge pressure in a control device for a construction machine according to an embodiment of the present invention.

FIG. 7 is a flowchart for explaining negative flow control in the control device for a construction machine according to one embodiment of the present invention.

FIG. 8 is a flowchart illustrating a main routine of optimal power distribution pump tilt angle control in the control device for a construction machine according to one embodiment of the present invention.

FIG. 9 is a flowchart illustrating a pump tilt angle control routine at the time of high power in the control device for the construction machine according to the embodiment of the present invention.

FIG. 10 is a flowchart illustrating a low-power pump tilt angle control routine in the control device for the construction machine according to the embodiment of the present invention.

FIG. 11 is a flowchart illustrating a pump tilt angle control routine at the time of lift / turn in the control device for the construction machine according to the embodiment of the present invention.

FIG. 12 is a schematic perspective view showing a conventional construction machine.

[Explanation of symbols]

 DESCRIPTION OF SYMBOLS 1 Controller (control means) 2 Low power / high power judgment means 3 Digging judgment means 4 Excavation judgment means 5 Lift / turning judgment means 6 Pump tilt angle control means 6A Basic tilt angle control unit 6B Digging control unit 6C EX Cavitation control unit 6D Lift / turn control unit 7 Proportional pressure reducing valve control unit for turning 51 First hydraulic pump 52 Second hydraulic pump 54 Operating member 54a Operating member for boom 54b Operating member for stick 54c Operating member for bucket 54d Operating for turning Member 63 Control valve for turning 63a, 63b Proportional pressure reducing valve for turning 102 Upper revolving unit

 ──────────────────────────────────────────────────続 き Continued on the front page F term (reference) 2D003 AA01 AB02 AB03 AB04 AB05 AB06 BA02 BA05 BB07 BB12 CA04 DA03 DA04 DB02 DB03 DC02 5H316 AA09 AA18 CC01 CC10 DD07 EE22 EE25 ES02 FF05 FF06 GG03 GG09 HH04

Claims (9)

[Claims] 1. A plurality of hydraulic pumps driven by an engine provided in a construction machine to discharge hydraulic oil in a tank, a plurality of operating members operated by an operator, and a discharge flow rate from the plurality of hydraulic pumps Control means for controlling the tilt angles of the plurality of hydraulic pumps in order to adjust the hydraulic pressure, so that the control means can optimally distribute the engine output from the engine to each of the plurality of hydraulic pumps. A control device for a construction machine, wherein the tilt angles of the plurality of hydraulic pumps are controlled based on electric signals from the plurality of operation members. 2. The control means sets a distribution ratio of an engine output distributed to each of the plurality of hydraulic pumps, and sets a tilt angle of each of the plurality of hydraulic pumps so that the distribution ratio becomes the distribution ratio. The control device for a construction machine according to claim 1, wherein 3. A pressure sensor for detecting a pump discharge pressure of hydraulic oil discharged from the plurality of hydraulic pumps, wherein the control means is configured to output a pressure based on an upper limit output set in accordance with a detection signal from the pressure sensor. The engine output allocated to each of the plurality of hydraulic pumps is set by the control, and the tilt angle of each of the plurality of hydraulic pumps is controlled so as to become the allocated output. A control device for a construction machine according to the above. 4. The operating member for turning, which is operated for turning the construction machine, and the operating member for stick, which is operated for operating a stick provided on the construction machine, wherein the plurality of operating members are operated. An excavation judging means for judging whether or not the excavation work involves a turning operation and a stick operation based on an electric signal from the turning operation member and the stick operation member. And a pump tilt angle control means for controlling a tilt angle of the hydraulic pump to adjust a discharge flow rate from the hydraulic pump. If it is determined that the operation is a carvation operation, the engine output from the engine is optimally distributed to each of the hydraulic pumps. And controlling the respective tilt angles of the plurality of hydraulic pumps of the on the basis of the operation member and the electrical signal from the operation member stick times, construction machine control device according to claim 1. 5. A pressure sensor for detecting a pump discharge pressure of hydraulic oil discharged from the plurality of hydraulic pumps, wherein the pump tilt angle control means is set according to a detection signal from the pressure sensor. The engine output allocated to each of the plurality of hydraulic pumps is set by subtracting the minimum required turning power required for turning the construction machine from the upper limit output, and the above-mentioned allocated output is set so as to become the allocated output. The control device for a construction machine according to claim 4, wherein the tilt angle of each of the plurality of hydraulic pumps is controlled. 6. A stick operating member, wherein the plurality of operating members are operated to operate a stick provided to the construction machine, and a bucket operated to operate a bucket provided to the construction machine. Digging determining means for determining whether or not the digging operation involves stick operation and bucket operation based on electric signals from the stick operating member and the bucket operating member. And pump tilt angle control means for controlling the tilt angle of the hydraulic pump so as to adjust the discharge flow rate from the hydraulic pump. The pump tilt angle control means performs a digging operation by the digging determination means. If it is determined that there is, the engine output from the engine is optimally distributed to each of the hydraulic pumps. And controlling the respective tilt angles of the plurality of hydraulic pumps of the based on the electric signal from the tick operation member and the bucket operation member, a construction machine control device according to claim 1. 7. A pressure sensor for detecting a pump discharge pressure of hydraulic oil discharged by the plurality of hydraulic pumps, wherein the pump tilt angle control means is set according to a detection signal from the pressure sensor. The engine output allocated to each of the plurality of hydraulic pumps is set by subtracting the minimum required output of the bucket required to operate the bucket from the upper limit output, and the above-described output is set so as to be the allocated output. The control device for a construction machine according to claim 6, wherein the tilt angles of the plurality of hydraulic pumps are controlled. 8. A boom operating member which is operated to operate a boom provided in the construction machine, and a turning operation member which is operated to turn the construction machine. Wherein the control means includes a lift / boom operation and a swing operation based on electric signals from the boom operation member and the swing operation member.
Lift / turn determination means for determining whether or not the vehicle is turning, and pump tilt angle control means for controlling the tilt angle of the hydraulic pump to adjust the discharge flow rate from the hydraulic pump; The tilt angle control means is adapted to optimally distribute the engine output from the engine to each of the plurality of hydraulic pumps when the lift / turn determination means determines that a lift / turn is being performed. The control device for a construction machine according to claim 1, wherein the tilt angles of the plurality of hydraulic pumps are controlled based on electric signals from the turning operation member and the boom operation member. 9. A pressure sensor for detecting a pump discharge pressure of hydraulic oil discharged from the plurality of hydraulic pumps, wherein the pump tilt angle control means is set according to a detection signal from the pressure sensor. The engine output allocated to each of the plurality of hydraulic pumps is set by subtracting the minimum required turning power required for turning the construction machine from the upper limit output, and the above-mentioned allocated output is set so as to become the allocated output. The control device for a construction machine according to claim 8, wherein the tilt angles of the plurality of hydraulic pumps are controlled.