WO2000065240A1

WO2000065240A1 - Device and method for control of construction machinery

Info

Publication number: WO2000065240A1
Application number: PCT/JP2000/002442
Authority: WO
Inventors: Kimimasa Onda
Original assignee: Shin Caterpillar Mitsubishi Ltd.
Priority date: 1999-04-27
Filing date: 2000-04-14
Publication date: 2000-11-02
Also published as: JP2000309948A; JP3645740B2

Abstract

A device and a method for control of construction machinery capable of controlling a pump flow rate so that a pump delivery pressure does not rise excessively even in a grading operation so as to suppress an engine output loss, and thus preventing a fuel efficiency from being deteriorated; the device comprising hydraulic pumps (51) and (52), a plurality of operation members (54), and a control means (1) to control a delivery flow rate from the hydraulic pumps; the control means (1) comprising a boom fine operation judgment means (2) which judges whether or not a boom fine operation is performed based on the manipulated variable of a boom operating member (54a), a stick fine operation judgment means (3) which judges whether or not a stick fine operation is performed based on the manipulated variable of a stick operating member (54b), a bucket fine operation judgment means (4) which judges whether or not a bucket fine operation is performed based on the manipulated variable of a bucket operating member (54c), and a pump inclination angle control means (5) which performs the inclination angle control of the hydraulic pumps (51) and (52) based on the judgment results of the boom fine operation judgment means (2), stick fine operation judgment means (3), and bucket fine operation judgment means (4).

Description

Description Control device and control method for construction machinery

The present invention relates to a control of a construction machine which controls an operation of a hydraulic actuator such as a boom cylinder / bucket cylinder by controlling a tilt angle of a hydraulic pump provided in the construction machine to control a pump discharge flow rate. The present invention relates to an apparatus and a control method. Background art

In general, a construction machine such as a hydraulic excavator includes an upper swing body 102, a lower traveling body 100, and a working device 118 as shown in FIG.

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 has a lower track 100 On the other hand, it is provided so as to be pivotable in a horizontal plane.

The working device 118 mainly consists of a boom 103, a stick 104, a bucket 108, and the like, and the boom 103 can rotate with respect to the upper swing body 102. Is pivoted to. A stick 104 is connected to the end of the boom 103 so as to be rotatable in the same vertical plane.

A boom drive hydraulic cylinder (boom cylinder, hydraulic actuator) 105 for driving the boom 103 is provided between the upper swing body 102 and the boom 103. In addition, between the boom 103 and the stick 104, there are provided 106 stick driving hydraulic cylinders (stick cylinders, hydraulic actuators) for driving the stick 104. Also, between the stick 104 and the bucket 108, A bucket driving hydraulic cylinder (bucket cylinder, hydraulic actuator) 107 for driving the bucket 107 is provided.

Each of the cylinders 105 to 107 described above includes a plurality of hydraulic pumps driven by an engine (mainly a diesel engine), a boom control valve, a stick control valve, a packet control valve, and the like. A hydraulic circuit (not shown) including a control valve is connected, and hydraulic oil of a predetermined hydraulic pressure is supplied from each hydraulic valve via each control valve, and driven in accordance with the hydraulic pressure supplied in this manner. It has become so.

Here, a plurality of control valves are interposed in hydraulic oil supply passages (hydraulic pump cylinder passages, PC passages) for supplying and discharging hydraulic oil to and from each cylinder 105 to 107 and hydraulic pumps. In addition to a PC throttle and a hydraulic oil discharge passage (cylinder tank passage, CT passage), a c-τ throttle is provided, and a bypass passage from the hydraulic pump to the reservoir tank is provided. It also has a bypass bypass restriction.

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

The operating room 101 has left lever, right lever, and left lever as operating members for controlling the operation (running, turning, boom turning, stick turning, and packet turning) of the excavator. Left pedal and right pedal etc. ing.

Then, for example, when the operator operates these operating members such as levers and pedals, each control valve of the hydraulic circuit is controlled, and each cylinder 105 to 107 is driven. 3. The stick 104 and the bucket 108 can be rotated.

In addition, a pilot hydraulic circuit is provided to control each control valve. As a result, in order to operate the boom 103 and the stick 104, the boom operating member in the driver's operation room 101 is operated by operating the stick operating member. Act on the valve-to-stick control valve to drive the boom control valve or stick control valve to the required position. This regulates the supply and discharge of hydraulic oil to the boom drive hydraulic cylinder 105 and the stick drive hydraulic cylinder 106, and the cylinders 105, 106 are driven to expand and contract to the required length. Will be done.

As described above, in the hydraulic excavator, the cylinders 105 to 107 are driven to expand and contract, and the working devices 118 such as the boom 103, the stick 104, and the baguette 108 are driven. Various operations such as excavation work are performed.

By the way, as one operation in such various operations, there is, for example, a so-called leveling operation (leveling operation). In this leveling operation, the above-described boom-up, stick-in, and baguette-in are simultaneously operated.

Here, when the boom up operation is performed, the boom 103 is driven as follows.

That is, when the boom-up operation is performed, the boom 103 can be raised by extending the boom drive hydraulic cylinder 105. this In this case, the pilot oil pressure is applied to the boom control valve through the pilot oil passage. As a result, the spool position of the boom control valve becomes the boom raising position, and the hydraulic oil from the hydraulic pump is supplied to one chamber of the boom driving hydraulic cylinder 105 through the oil passage. On the other hand, hydraulic oil in the other room of the boom drive hydraulic cylinder 105 is discharged to the tank through the oil passage. This causes the boom 103 to rotate upward as shown by the arrow a in FIG. 8 while the boom drive hydraulic cylinder 105 extends.

When the stick-in operation is performed, the stick 104 is driven as follows.

In other words, when the stick-in operation is performed, the stick drive hydraulic cylinder 106 may be extended to lower the stick 104. In this case, the pilot oil pressure is applied to the stick control valve through the pilot oil passage. Thereby, the spool position of the stick control valve becomes the stick lowered position, and the hydraulic oil from the hydraulic pump is supplied to one chamber of the stick driving hydraulic cylinder 106 through the oil passage. On the other hand, the hydraulic oil in the other room of the stick driving hydraulic cylinder 106 is discharged to the tank through the oil passage. As a result, the stick 104 is rotated downward as shown by the arrow d in FIG. 8 while the stick driving hydraulic cylinder 106 is extended.

Further, when a packet-in operation is performed, the packet 108 is driven as follows.

In other words, when the bucket-in operation is performed, the bucket 108 can be closed by extending the bucket driving hydraulic cylinder 107. In this case, the pilot oil pressure is applied to the bucket control valve through the pilot oil passage. As a result, the spool position of the packet control valve becomes the baggage closed position, and the hydraulic oil from the hydraulic pump is bucketed through the oil passage. The hydraulic cylinder for driving 107 is supplied to one chamber. On the other hand, hydraulic oil in the other chamber of the packet driving hydraulic cylinder 107 is discharged to the tank through the oil passage. As a result, the bucket 108 is moved in the closing direction as shown by an arrow f in FIG. 8 while the packet driving hydraulic cylinder 107 is extended.

In addition, in order to ensure the simultaneous operability of these booms 103, sticks 104 and buckets 108, the pressure of the hydraulic oil discharged from the hydraulic pump must be equal to the operating pressure of these working machines. It must be set to the maximum pressure (maximum pressure value). As a method of securing the hydraulic oil pressure, the pump discharge flow rate is slightly larger than the total flow rate of the hydraulic oil supplied to each cylinder, and the excess pump discharge flow rate is reduced by the control valve bypass passage throttle to increase the pressure. It is common.

By the way, as mentioned above, there is, for example, a leveling operation as an operation for simultaneously operating the boom 103, the stick 104, and the bucket 108. This leveling operation includes any of a boom-up, a stick-in, and a baguette-in. Is also performed by a fine operation. Also, in this case, the load direction of the stick-in and bucket-in is the direction of falling of the linkage's own weight.Therefore, in these operations, the flow rate of the hydraulic oil discharged from the hydraulic pump is not so necessary, and the pressure of the hydraulic oil is also low. Not very necessary.

In such a leveling operation, the flow rate of the hydraulic oil discharged from the hydraulic pump during the other operation in which one of the boom 103, the stick 104, and the bucket 108 is operated without fine operation is the same. When an amount of hydraulic oil is supplied, an excess flow of hydraulic oil is supplied, and the pump discharge pressure from the hydraulic pump is also excessively increased.

As described above, the pump flow rate of the hydraulic pump is controlled so that the pump discharge pressure becomes excessive. This results in loss of gin output, which in turn leads to worse fuel economy. The present invention has been made in view of such a problem, and when the boom, the stick, and the bucket are finely operated during so-called leveling work, the pump flow control is performed so that the pump discharge pressure does not excessively increase. Accordingly, an object of the present invention is to provide a control device and a control method for a construction machine, which are capable of suppressing a loss in engine output and, consequently, preventing deterioration of fuel efficiency. Disclosure of the invention

A control device for a construction machine according to the present invention includes a hydraulic pump for discharging hydraulic oil in a tank, a plurality of operating members operated by an operator, and control means for controlling a discharge flow rate from the hydraulic pump. A control unit configured to determine whether the boom fine operation is performed based on an operation amount of the boom operation member of the plurality of operation members; and a stick operation of the plurality of operation members. A stick fine operation determining means for determining whether or not a stick fine operation has been performed based on the operation amount of the member; and a bucket fine operation based on the operation amount of the bucket operating member of the plurality of operating members. Bucket fine operation determining means for determining whether the hydraulic pump is tilted based on the determination results of the boom fine operation determining means, the stick fine operation determining means and the bucket fine operation determining means. It is characterized in that it comprises a pump tilting angle control means for controlling.

Preferably, the plurality of operation members are configured to output an electric signal according to the operation amount, and the control means is configured to perform a tilt angle control of the hydraulic pump based on the electric signals from the plurality of operation members. Constitute.

Further, the boom fine operation determining means is configured to determine whether or not the boom up fine operation has been performed, and the stick fine operation determining means includes: The bucket fine operation determining means is configured to determine whether the bucket-in fine operation has been performed, and the pump tilt angle control means is configured to determine whether the bucket fine operation has been performed. When the fine operation determining means, the stick fine operation determining means, and the bucket fine operation determining means determine that the boom-up fine operation, the stick-in fine operation, and the bucket-in fine operation have been performed, the boom operating member and the stick operation. It is also preferable to control the tilt angle of the hydraulic pump in accordance with an electric signal from the member and the bucket operating member.

Further, the boom fine operation determining means is configured to determine whether a boom up fine operation has been performed, and the stick fine operation determining means is configured to determine whether a States Quinn fine operation has been performed. The operation determining means is configured to determine whether a bucket-in operation has been performed, and the pump tilt angle controlling means is boom-up by the boom fine operation determining means, the stick fine operation determining means, and the bucket fine operation determining means. The discharge flow rate from the hydraulic pump when it is determined that the fine operation, the stick-in fine operation, and the bucket-in fine operation have been performed, and the discharge flow from the hydraulic pump when any of the fine operations is not a fine operation. The hydraulic pump may be configured to perform tilt angle control so as to reduce the flow rate below the flow rate.

A control method for a construction machine according to the present invention includes a hydraulic pump for discharging hydraulic oil in a tank, a plurality of operating members operated by an operator, and control means for controlling a discharge flow rate from the hydraulic pump. A machine control method, comprising: a boom fine operation determining step of determining whether a boom fine operation has been performed based on an operation amount of a boom operating member of the plurality of operating members; A stick fine operation determining step of determining whether a stick fine operation has been performed based on the operation amount of the stick operating member; and a stick fine operation determining step based on the operation amount of the bucket operating member of the plurality of operating members. bucket And a control step of performing a tilt angle control of the hydraulic pump based on a result of the determination in the determining step.

Preferably, in the control step, the tilt angle of the hydraulic pump is controlled based on an electric signal corresponding to the operation amounts of the plurality of operation members.

In the boom fine operation determination step, it is determined whether a boom-up fine operation has been performed. In the stick fine operation determination step, it is determined whether a stick-in fine operation has been performed. In the bucket fine operation step, a bucket-in fine operation is performed. In the control step, when it is determined in the determination step that the boom-up fine operation, the stick-in fine operation, and the bucket-in fine operation have been performed, the boom operating member and the stick operating member are determined. It is also preferable to control the tilt angle of the hydraulic pump in response to an electric signal from the bucket operating member.

Further, in the boom fine operation determination step, it is determined whether a boom up fine operation has been performed. In the stick fine operation step, it is determined whether a stick-in fine operation has been performed. In the bucket fine operation step, a packet in In the control step, if it is determined in the determination step that the boom-up fine operation, the stick-in fine operation, and the bucket-in fine operation have been performed, the discharge flow rate from the hydraulic pump is finely controlled. It is also preferable to control the tilt angle of the hydraulic pump so as to reduce the discharge flow rate from the hydraulic pump when any one of the operations is not a fine operation.

According to the control device and the control method for a construction machine of the present invention configured as described above, the boom-up fine operation and the stick are performed based on the operation amounts of the boom operation member, the stick operation member, and the baguette operation member. If the in-fine operation and the bucket-in fine operation are performed at the same time, it is determined that it is so-called leveling work, and the optimum pump flow rate for this leveling work is determined. Since the tilt angle control of the hydraulic pump is performed in a short time, the output loss of the engine that drives the hydraulic pump can be suppressed, and the fuel efficiency can be improved.

If the boom-up fine operation, the stick-in fine operation, and the bucket-in fine operation are simultaneously performed based on the operation amounts of the boom operation member, the stick operation member, and the packet operation member, it is determined that the operation is a leveling operation. The tilt angle of the hydraulic pump is controlled so as to reduce the pump discharge flow according to the operation amount of the boom operating member, the stick operating member, and the bucket operating member so that the pump discharge pressure does not excessively increase. However, the output loss of the engine that drives the hydraulic pump can be suppressed, and the fuel efficiency can be improved. BRIEF DESCRIPTION OF THE FIGURES

FIG. 1 is a control block diagram for explaining tilt angle control of a hydraulic pump in a control device for a construction machine according to an embodiment of the present invention.

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

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

FIG. 4 is a diagram showing 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. 5 is a diagram showing the relationship between the allowable flow rate of the negative flow control and the pump discharge pressure in the control device for the construction machine according to the embodiment of the present invention.

FIG. 6 is a schematic diagram of a control device for a construction machine according to an embodiment of the present invention. 6 is a flow chart for explaining a gating control. FIG. 7 is a flowchart for explaining pump tilt angle control (control method) in the control device for a construction machine according to one embodiment of the present invention. FIG. 8 is a schematic perspective view showing a conventional construction machine. BEST MODE FOR CARRYING OUT THE INVENTION

Hereinafter, embodiments of the present invention will be described with reference to the drawings.

First, a construction machine according to the present embodiment will be described.

This construction machine is a construction machine (working machine) such as a hydraulic shovel, as described in the prior art (see FIG. 8), and works with the upper revolving unit 102 and the lower traveling unit 100. The device consists of 1 1 8.

The undercarriage 100 has a right track 10OR and a left track 100L that can be driven independently of each other, while the upper revolving structure 102 has It is provided so that it can turn in a horizontal plane.

In addition, the working device 118 mainly comprises a boom 103, a stick 104, a knotting 108, and the like, and the boom 103 can rotate with respect to the upper swing body 102. Is pivoted to. A stick 104 is connected to the end of the boom 103 so as to be rotatable in the same vertical plane.

A boom drive hydraulic cylinder (boom cylinder, hydraulic actuator) 105 for driving the boom 103 is provided between the upper swing body 102 and the boom 103. At the same time, a hydraulic cylinder (stick cylinder, hydraulic actuator) 106 for driving the stick 104 is provided between the boom 103 and the stick 104. A bucket driving hydraulic cylinder (bucket cylinder, hydraulic actuator) 107 for driving the bucket 108 is provided between the stick 104 and the bucket 108. With such a configuration, the boom 103 is in the directions a and b in the figure, the stick 104 is in the directions c and d in the figure, and the knocket 108 is the direction e and f in the figure. It is configured to be rotatable.

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 100L and the right track 100R are provided with traveling motors 109L and 109R as independent power sources, respectively. The revolving unit 102 is provided with a revolving motor 110 for driving the upper revolving unit 102 to revolve with respect to the lower traveling unit 100.

These traveling motors 109 L and 109 R and the turning motor 110 are configured as hydraulic motors operated by hydraulic pressure, and as described later, the engine (mainly a diesel engine) 5 Hydraulic oil from a plurality (here, two) of hydraulic pumps 51, 52 driven by 0 is supplied at a predetermined pressure via a hydraulic circuit 53, and the hydraulic pressure supplied in this manner is provided. The hydraulic motors 109 L, 109 R, and 110 are driven in accordance with the conditions.

Here, the hydraulic pumps 51 and 52 discharge the hydraulic 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) is used. (Piston 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. To the operation signal from controller 1. Based on the change, the stroke amount of the piston can be changed to adjust the pump discharge flow rate.

In this way, the inclination of the swash plate can be changed based on the operation signal from the controller 1, and in addition to the pressure of the hydraulic oil in the oil passage that composes the hydraulic circuit, each operation by operating Since the amount of operation of the member 54 can be taken into account, the operator's driving feeling is improved compared to the conventional method in which the pressure of the hydraulic oil in the oil passage is guided to change the inclination of the swash plate. You can do that.

The engine 50 is designed so that the operator can set the engine speed by switching the engine speed setting dial. Here, the maximum engine speed (for example, about 200 rpm) and the minimum engine speed are set. It is designed to be able to be switched in multiple stages between a rotating speed (for example, about 100 rpm). Note that the engine speed is not limited to such a stepwise switching, but may be a type that can be changed smoothly. The total horsepower of the engine 50 is consumed to drive these hydraulic pumps 51, 52 and a pilot pump 83, which will be described later.

In addition, the cylinders 105 to 107 are also driven by the engine 50 in the same manner as the traveling motors 109 L and 109 R and the turning motor 110. Are driven by the hydraulic pressure of hydraulic oil supplied from two hydraulic pumps 51 and 52.

The operation room 101 has a left lever, a right lever, a left pedal and a right pedal for controlling the operation of the hydraulic excavator (running, turning, boom turning, stick turning, and baguette turning). A plurality of operation members 54 such as pedals 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. For example, when the operator operates these operating members 54, the control valves 57 to 60 and 62 to 65 interposed in the hydraulic circuit 53 are controlled, and the cylinders 1 to 1 are controlled. 05 to 107 and hydraulic motors 109L, 109R, 110 are driven. As a result, the upper swing body 102 can be turned, the boom 103, the stick 104, the bucket 108, and the like can be turned, and the hydraulic shovel can be run.

The member operated when rotating the boom 103 is referred to as a boom operating member 54a, and the member operated when rotating the stick 104 is referred to as a stick operating member 54b. A member operated when rotating the bucket 108 is referred to as a bucket operating member 54c.

Next, a hydraulic circuit 53 for controlling these cylinders and the like will be described.

As shown in FIG. 2, the hydraulic circuit 53 includes a first circuit unit 55 and a second circuit unit 56.

Among them, the first circuit section 55 is an oil passage connected to the first hydraulic pump 51.

6 1 and control of the right travel motor control valve 57 interposed in the oil passage 61, the packet control valve 58, the first boom control valve 59, the second stick control valve 60 etc. And a valve.

Then, the hydraulic oil from the first hydraulic pump 51 is supplied to the right traveling motor 109 R via the oil passage 61, the right traveling motor evening control valve 57, and the right traveling motor 109 R Is to be driven. The hydraulic oil from 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 oil passage 61, It is supplied to the boom drive hydraulic cylinder 105 via the first boom control valve 59, and is further connected to the stick drive hydraulic cylinder 106 via the oil passage 61 and the second stick control valve 60. To each cylinder 1 0 5, 1 0 6, 107 is driven.

A throttle (throttle with a relief valve) 81 is provided downstream of the oil passage 61 of the first circuit portion 55, and hydraulic fluid from the first hydraulic pump 51 is supplied to the reservoir through the throttle 81. It returns to tank 70.

The second circuit section 56 includes an oil passage 66 connected to the second hydraulic pump 52, a left traveling motor control valve 62 interposed in the oil passage 66, and a turning motor control valve 6 3 , A control valve for the first stick 64, a control valve for the second boom 65, etc .;

Then, the hydraulic oil from the second hydraulic pump 52 is supplied to the left traveling motor 109 L via the oil passage 66 and the left traveling motor control valve 62, whereby the left traveling motor 1 0 9 L is driven. Hydraulic oil from the second hydraulic pump 52 is supplied to the swing motor 110 via the oil passage 66 and the swing motor control valve 63, whereby the swing motor 110 is driven. It has become so. Further, the hydraulic oil from the second hydraulic pump 52 is supplied to the hydraulic cylinder 106 for driving the stick via the oil passage 66 and the control valve 64 for the first stick. It is supplied to the boom drive hydraulic cylinder 105 via the boom control valve 65, whereby the respective cylinders 105, 106 are driven.

A throttle (a throttle with a relief valve) 82 is provided on the downstream side of the oil passage 66 of the second circuit portion 56, and the hydraulic oil from the second hydraulic pump 52 is reservoired through the throttle 82. It is designed to return to one tank 70.

The control valves 57 to 60 and 62 to 65 are housed in a control unit (not shown).

As described above, in the present embodiment, the second stick is set so that a sufficient hydraulic oil is supplied to the important stick 104 in the operation of the construction machine even at the same time when the other work machine 118 is operated simultaneously. Operation of the circuit section 56 from the second hydraulic pump 52 In addition to the oil, hydraulic oil from the first hydraulic pump 51 of the first circuit section 55 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 second stick control valve 60 is interposed in the oil passage 61 of the first circuit portion 55. Is equipped. 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. The hydraulic cylinder for driving the stick 106 can supply and discharge the hydraulic oil c.Sufficient operation of the boom 103 when operating simultaneously with other work equipment ₁₁₈ as well as _c In order to supply oil, in addition to the hydraulic oil from the first hydraulic pump 51 of the first circuit section 55, the hydraulic oil from the second hydraulic pump 52 of the second circuit section 56 is also used for boom drive. As a result, the control valve 59 for the first boom is interposed in the oil passage 61 of the first circuit section 55, and the oil in the second circuit section 56 is supplied to the hydraulic cylinder 105. A second boom control valve 65 is interposed in the road 66. The first boom control valve 59 is controlled by the proportional control valves 59a and 59b, and the second boom control valve 65 is controlled by the proportional control valves 65a and 65b. The hydraulic oil can be supplied to and discharged from the boom drive hydraulic cylinder 105.

In this embodiment, a stick regeneration valve 76 is interposed in the oil passages 67, 68 for supplying and discharging hydraulic oil to and from the hydraulic cylinder 106 for driving the stick. A predetermined amount of hydraulic oil can be regenerated from the side oil passage to the hydraulic oil supply-side oil passage.

Similarly, boom regeneration valves 77 are also interposed in the oil passages 7 8 and 7 9 that supply and discharge hydraulic oil to the boom drive hydraulic cylinder 105, and operate from the hydraulic oil discharge side oil passage. A predetermined amount of hydraulic oil can be regenerated to the oil supply side oil passage. Here, as shown in FIG. 3, each of the control valves 57 to 60 and 62 to 65 is configured as a spool valve, and each is provided with a plurality (here, five) of throttles.

That is, as shown in FIG. 3, each of the control valves 57 to 60 and 62 to 65 is an oil passage that connects the first hydraulic pump 51 and the second hydraulic pump 52 to the stick driving hydraulic cylinder 106. (Hydraulic oil supply passage, P-C passage) 61-a, 66-a, a P-C throttle 8 and an oil passage connecting the stick drive hydraulic cylinder 106 and the reservoir tank 70 ( (Hydraulic oil discharge passage, C-T passage) Connects the C-T throttle 9 interposed between 66 b, 69, the first hydraulic pump 51, the second hydraulic pump 52, and the reservoir tank 70. The oil passage (bypass passage) 61 b, 66 c is provided with a bypass passage throttle 10 interposed therebetween.

Although the stick control valves 60 and 64 are in the stick lowered position in FIG. 3, the stick control valves 60 and 64 are moved upward in FIG. By interposing the bypass passage restrictor 10 in the bypass passages 61b and 66c, the stick control valves 60 and 64 can be set to the neutral position. In Fig. 3, by moving it to the uppermost position, the PC throttles 8 of the stick control valves 60 and 64 are interposed in the PC passages 61a and 66a, and the stick control is performed. By interposing the C—T throttle 9 of the valves 60 and 64 in the C—T passages 66 b and 69, the stick control valves 60 and 64 can be in the stick-up position.

In setting the diameters of the apertures 8, 9, and 10, the operating members 54 are fully operated to ensure the interlocking of the working devices 118 such as the boom 103 and the stick 104. All working devices 1 18 are considered to move when they are in use. The opening area of the oil passages 61 a and 66 a communicating the first hydraulic pump 51 and the second hydraulic pump 52 and the stick driving hydraulic cylinder 106 by the P_C throttle 8 (the hydraulic oil supply) The opening area of the passage and the PC opening area are adjusted.

The opening area (opening area of the hydraulic oil discharge passage, opening area of C-T opening) of the oil passages 66 b and 69 communicating the stick drive hydraulic cylinder 106 and the reservoir tank 70 is increased by the C-T throttle 9. Adjusted.

By the bypass passage restrictor 10, the opening area (opening area of the bypass passage) of the oil passages 61b and 66c communicating the first hydraulic pump 51 and the second hydraulic pump 52 with the reservoir tank 70 is reduced. Adjusted.

By the way, in this embodiment, as shown in FIG. 2, in order to control each of the control valves 57 to 60, 62 to 65, a pilot pump 83 and proportional pressure reducing valves 57a to 60a, 57b A pilot hydraulic circuit including を 60 b, 62 a〜65 a, and 62 b〜65 b is provided. In Fig. 2, the pilot pump 83 provided in the pilot hydraulic circuit and the proportional pressure reducing valves 57a to 60a, 57b to 60b, 62a to 65a, 62b 665b only, the pilot oil passage is omitted, and the pilot oil pressure is indicated by the symbol P. Here, the proportional pressure reducing valves 57a to 60a, 57b to 60b, 62a to 65a, 62b to 65b are solenoid valves, and are operated by the controller 1 described later. It is activated by a signal. As a result, the pilot oil pressure from the pilot pump 83 is applied to each of the control valves 57 to 60 and 62 to 65 as a predetermined pressure based on the operation signal from the controller 1.

With such a configuration, for example, in order to operate the boom 103, the boom operating member 54a in the operation room 101 is operated to reduce the hydraulic pressure P from the pilot pump 83. Through a pie mouth oil passage not shown By operating the boom control valves 59, 65, the boom control valves 59, 65 are moved to required positions. Accordingly, 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 drive hydraulic cylinder 105 may be contracted. In this case, the pilot port hydraulic pressure is applied to 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 becomes oily. It is supplied to one chamber of the boom drive hydraulic cylinder 105 via the passages 95 and 79, and is supplied to one chamber of the boom drive hydraulic cylinder 105. On the other hand, the hydraulic oil in the other room of the boom drive hydraulic cylinder 105 is discharged to the reservoir tank 70 through the oil passages 78 and 69. As a result, the boom driving hydraulic cylinder 105 contracts while the boom 103 is turned downward as shown by the arrow b in FIG.

Conversely, to rotate the boom 103 upward (boom up), the boom drive hydraulic cylinder 105 may be extended. In this case, the pilot oil pressure is applied to the first boom control valve 59 and the second boom control valve 65 through the pilot oil passage. As a result, the spool position of the first boom control valve 59 and the second boom control valve 65 becomes the boom upper rotation position (boom up position), and the first hydraulic pump 5 of the first circuit portion 55 Hydraulic oil from 1 is supplied to one chamber of the boom drive hydraulic cylinder 105 through oil passages 95, 788, and further actuated from the second hydraulic pump 52 of the second circuit section 56. Oil is supplied to the other chamber of the boom drive hydraulic cylinder 105 via the oil passages 66a, 90, 78. On the other hand, the hydraulic oil in one room of the boom drive hydraulic cylinder 105 flows through the oil passages 79, 91, 66 b or 79, 69. Is discharged to the reservoir tank 70. This causes the boom 103 to rotate upward as shown by the arrow a in FIG. 8 while the boom drive hydraulic cylinder 105 extends.

In addition, in order to maintain the current state of the boom drive hydraulic cylinder 105, the pilot hydraulic pressure is applied to the first boom control valve 59 and the second boom control valve 65 appropriately to control the first boom. The position of each spool of the valve 59 and the second boom control valve 65 may be set to the neutral position (the hydraulic supply / discharge path shutoff position). As a result, 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.

Further, for example, to operate the stick 104, the operating member 54 in the operation room 101 is operated, and the pilot hydraulic pressure P from the pilot pump 83 is passed through a pipe oil passage (not shown). By acting on the stick control valves 60 and 64, the stick control valves 60 and 64 are driven to required positions. As a result, the hydraulic fluid of the stick driving hydraulic cylinder 106 is adjusted for supply and discharge, and these cylinders 105 and 106 are driven to extend and contract to a required length, whereby the stick 104 is operated. You.

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 rotation position (stick-in position), and the hydraulic oil from the first hydraulic pump 51 of the first circuit portion 55 flows through the oil passage. It is supplied to one chamber of the stick driving hydraulic cylinder 106 via 61 and 67. On the other hand, hydraulic oil in the other chamber of the stick driving hydraulic cylinder 106 is discharged to the reservoir tank 70 via the oil passages 68, 69. As a result, the stick driving hydraulic cylinder 106 extends while the stick 104 extends. Is rotated inward as shown by arrow d in FIG.

Conversely, to rotate the stick 104 outward (stick out), the stick drive 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 passage. It is supplied to the other chamber of the stick driving hydraulic cylinder 106 via 61 and 68. On the other hand, the hydraulic oil in one chamber of the stick driving hydraulic cylinder 106 is discharged to the reservoir tank 70 through the oil passages 67, 69. As a result, the stick driving hydraulic cylinder 106 is contracted while the stick 104 is rotated outward as shown by the arrow c in FIG.

Furthermore, in order to maintain the current state of the stick drive hydraulic cylinder 106, the pilot hydraulic pressure is applied to the second stick control valve 60 as appropriate, and each spool of the second stick control valve 60 is controlled. Should be set to the neutral position (hydraulic supply / discharge path cutoff position). As a result, the supply and discharge of the 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.

Also, for example, to operate the bucket 108, the bucket operating member 54c in the operator's cab 101 is operated, and the pilot port hydraulic pressure P from the pilot pump 83 is not shown. By acting on the bucket control valve 58 through the pipe oil passage, the bucket control valve 58 is moved to a required position. As a result, the supply and discharge of the hydraulic oil for the packet driving hydraulic cylinder 107 is adjusted, and these cylinders 107 are driven to expand and contract to a required length, whereby the packet 108 is operated.

For example, to rotate packet 108 inward (baguette in), The bucket driving hydraulic cylinder 107 may be extended. In this case, the pilot oil pressure is applied to the bucket control valve 58 through the pilot oil passage. As a result, the spool position of the bucket control valve 58 becomes the packet inside rotation position (bucket-in position), and the hydraulic oil from the first hydraulic pump 51 of the first circuit portion 55 passes through the oil passage 61. , 92, and is supplied to one chamber of the hydraulic cylinder 107 for driving the packet. On the other hand, the 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, 69. This causes the bucket 108 to rotate inward as indicated by the arrow f in FIG. 8, 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 applied to the bucket control valve 58 through the pilot oil passage. As a result, the spool position of the bucket control valve 58 becomes the baguette outside rotation position (packet open position), and the hydraulic oil from the first hydraulic pump 51 of the first circuit portion 55 flows through the oil passages 94, After 93, it is supplied to the other chamber of the bucket driving hydraulic cylinder 107. 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. As a result, the baguette driving hydraulic cylinder 107 is contracted while the baguette 108 is rotated outward as shown by an arrow e in FIG.

Further, in order to maintain the current state of the bucket driving hydraulic cylinder 107, the pilot hydraulic pressure is applied to the bucket control valve 58 as appropriate, and the position of the spool of the bucket control valve 58 is set to the neutral position. (Hydraulic supply / discharge path cutoff position). As a result, the supply and discharge of hydraulic oil to and from the oil chamber of the bucket driving hydraulic cylinder 107 are 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 50 for driving the hydraulic pumps 51 and 52 is provided with an engine speed sensor 71, and a detection signal from the engine speed sensor 71 is transmitted to a controller 1 described later. It has been The controller 1 performs feedback control so that the actual engine speed becomes the target engine speed set by the engine speed setting dial during the operation.

Also, the first hydraulic pump 51 of the first circuit section 55 and the first hydraulic pump 51 of the second circuit section 56

(2) On the discharge side of the hydraulic pump 52, a pressure sensor (PZS-P1) 72 and a pressure sensor (PZS-P2) 73 are provided to detect the pump discharge pressure. The detection signals from 72 and 73 are sent to the controller 1 described later.

Further, downstream of each of the control valves 57 to 60 of the oil passage 61 of the first circuit unit 55 and each of the control valves 62 to 65 of the oil passage 66 of the second circuit unit 56, a pressure sensor ( PZS-N 1) 74 and pressure sensor (PZS-N 2) 75 are provided, and the detection signals from these pressure sensors 74 and 75 are sent to the controller 1 described later. .

Further, a pressure sensor (PZS-BMd) 80 is provided in an oil passage for supplying and discharging hydraulic oil to and from the boom drive hydraulic cylinder 105. The boom drive hydraulic cylinder 100 is provided by the pressure sensor 80. The rod side pressure (load pressure) of 5 can be detected. The detection signal from the pressure sensor 80 is sent to the controller 1 described later.

In this embodiment, the construction machine configured as described above is controlled. In particular, a controller 1 is provided.

Based on the detection signals from the sensors 71 to 75 and 80 and the electric signals from the operating member 54, the controller 1 controls the first hydraulic pump 51, the second hydraulic pump 52, 7 6, 7 7, and output control signals to each control valve 57 to 60 and 62 to 65 to control the tilt angle of the first hydraulic pump 51 and the second hydraulic pump 52, The position control of the control valves 57 to 60 and 62 to 65, the position control of the regeneration valves 76 and 77, and the like are performed.

Of these, the tilt angle control of the first hydraulic pump 51 and the second hydraulic pump 52 by the controller 1 is performed on the downstream side of the bypass passage 61 b of the first circuit section 55 and the second circuit section 56. Negative control is performed based on detection signals from the respective pressure sensors 74 and 75 provided on the downstream side of the bypass passage 66c. 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 a pump flow control with a negative characteristic that reduces the pump discharge flow rate when the pressure on the downstream side of the bypass passage 6 lb, 66 c increases. Say.

Here, the negative flow control is based on the operation amount of each operation member 54, that is, the flow 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 pressure. And horsepower control in which the pump discharge flow rate is controlled according to the pressure.

Among them, 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. It can control the speed of Kuchiyue overnight.

By the way, when the operation members 54 are fully operated and the pump discharge flow rate is maximum and the speed of the actuator is maximum, the pump discharge flow rate (that is, the speed of the actuator) is determined by the following equation. Is done.

Pump discharge flow Q = Allowable horsepower Pump discharge pressure P

In this state, if the load pressure applied to the actuator changes, the pump discharge pressure P also changes, and the pump discharge flow rate Q also changes according to the above equation, so that the speed of the actuator changes as well. Will be. 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. The magnitude of Q is referred to as horsepower control when 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 the operation members 54 and requests the maximum speed of the actuator, the actual speed of the actuator will not exceed the load pressure. It depends on the size. In this case, the horsepower of the engine 50 becomes the maximum allowable value.

Also, for example, in the case of operating a plurality of actuators simultaneously, even if each operating member 54 is not fully operated, hydraulic oil is supplied to each actuator and the negative control pressure is reduced. If the required flow rate falls below the allowable flow rate determined by the allowable horsepower, the pump tilt angle control is performed so that the required flow rate in the horsepower control is achieved.

By the way, when the operation member 54 is in the neutral position, that is, when the operator does not operate the operation member 54, the work machine 118 does not work at all, and there is no need to drive the actuator. The pump discharge flow rate from the hydraulic pumps 51 and 52 is desirably set to zero. For this reason, in the present embodiment, the control valves 57 to 60 and 62 to 65 are open centers (arranged so that the bypass passages 61b and 66c are open at the spool neutral position). When the operating member 54 is at the neutral position, the hydraulic oil supplied from the hydraulic pumps 51 and 52 returns to the reservoir tank 70 through the bypass passages 61 b and 66 c.

Thus, when the operation member 54 is in the neutral position, the bypass passages 6 1,

The pressure immediately upstream of the throttles 81, 82 interposed downstream of 66c increases, and the negative flow control controls the pump discharge flow from the variable displacement hydraulic pumps 51, 52 to decrease. It has become so.

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 and the like), and the remaining hydraulic oil is supplied to the bypass passages 6 1 b and 66 c. Through the reservoir tank 70.

The orifices 81, 82 are provided downstream of the bypass passages 61b, 66c as described above. Pressure sensors 74, 66 are provided in bypass passages 61b, 66c immediately upstream of these throttles 81, 82.

The tilt angle control of the hydraulic pumps 51 and 52 is performed based on the pressure immediately upstream of the throttles 81 and 82 detected by the pressure sensors 74 and 75. I'm sorry.

When the operator operates the operation member 54, the control valves 57 to 60 and 62 to 65 move according to the operation amount of the operation member 54, and the bypass passages 6 lb and 66 c are throttled, and the bypass passages are reduced. The flow rate of hydraulic oil flowing through 6 1 b and 6 6 c decreases, but the diameter of the throttles 8 1 and 8 2 is constant. The pressure, that is, the pressure detected by the pressure sensors 74 and 75, decreases, and the pump discharges according to the reduced pressure. The tilt angle control of the variable displacement hydraulic pumps 51 and 52 is performed so that the flow rate increases.

This means that the pump discharge flow rate is controlled to increase according to the operator's request, that is, the operation amount of the operation member 54 by the operator. This means that the speed of the actuator (each cylinder) can be controlled by controlling the pump discharge flow from 51 and 52.

Here, basic pump tilt angle control in the negative flow control by the controller 1 will be described.

In other words, the controller 1 reads the operating oil pressures (negative control pressures) P _N1 and P _N2 detected by the pressure sensors 74 and 75 and correlates the negative control pressure P _N with the required flow rate Q _N as shown in FIG. from a map, the request corresponds to the negative control pressure P _N1, P _N2 read flow Q _N1, Q _N2 (determined specifically main flow Q _N1, Q pump tilting angle corresponding to _{_N2} V _N1, V _N2) Is set. The required flow rate is the flow rate required in negative flow control. Also shows only 4 in negative control pressure P _N1 required flow rate Q that correspond to _N1 (specifically required flow rate Q _N1, a pump corresponding to the tilting angle V _N1).

On the other hand, the controller 1 reads the pump discharge pressures P _P1 and P _P2 detected by the pressure sensors ₇₂ and 73 and associates the pump discharge pressure P _P with the allowable flow rate Q _P as shown in FIG. from Matsupu, allowable flow corresponding to the pump discharge pressure read _{_{_{P P 1, P P2 Q P1}}} , Q P2 ( specifically allowable flow Q _P1, the pump tilting angle corresponding to Q _{_P2} V _P1, V _P2) Is set. The allowable flow rate refers to a pump discharge flow rate according to the allowable horsepower of the engine 50 that drives the first hydraulic pump 51 and the second hydraulic pump 52. Further, allowable flow Q _P1 (specifically allowable flow rate corresponding to the pump discharge pressure P _P1 in FIG. 5 Only the pump tilt angle V _P1 ) corresponding to Q _P1 is shown.

The controller 1 compares the required flow rates Q _N1 and Q _N2 with the allowable flow rates Q _P1 and Q _P2 and determines the smaller pump flow rate (required flow rate Q _N1 and Q _N2 or allowable flow rate Q _P1 and Q _P2 ). The pump tilt angle (pump tilt angle V _N1 , V _N2 or pump tilt angle V _P1 , V _P2 ) is set so that the first hydraulic pump 51 and the first hydraulic pump 51 are used as tilt angle control signals. The output is provided to the second hydraulic pump 52.

Next, the basic operation of the pump tilt angle control in the negative flow control by the controller 1 will be described with reference to the flowchart of FIG.

That is, first, at step S10, the negative control pressures P _N1 and P _N2 are read, and at step S20, the pump discharge pressures P _P1 and P _P2 are read.

Next, in step S30, the required flow rates Q _N1 and Q _N2 corresponding to the negative control pressures P _N1 and P _N2 read in step S 10 are calculated from the map of FIG. 4 and read in step S 20 in step 40. the allowable flow Q _P1, Q _P2 is calculated from the map of FIG. 5 corresponding to the pump discharge pressure _P _P1, P P ₂ that. Then, allowed the required flow rate Q _N1, Q _N2 in Step S 5 0 flow rate Q _P1, Q less whether determined than _P2, the result of this determination, required flow rate Q _N1, Q _N2 is allowable flow Q _P1, If it is determined that the flow rate is smaller than Q _P2 , the process proceeds to step S60, where the required flow rates Q _N1 and Q _N2 are set as the pump flow rates, and the routine returns. Thus, the tilt angles of the first hydraulic pump 51 and the second hydraulic pump 52 are set to be the tilt angles corresponding to the required flow rates Q _N1 and Q _N2 .

On the other hand, when it is determined that the required flow rates Q _NI and Q _N2 are equal to or higher than the allowable flow rates Q _P1 and Q _P2 , the process proceeds to step S70, where the allowable flow rates Q _P1 and Q _P2 are set as the pump flow rates and the return is performed. I do. As a result, the tilt angles of the first hydraulic pump 51 and the second hydraulic pump 52 become tilt angles corresponding to the allowable flow rates Q _P1 and Q _P2. It is set as follows.

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. In the present embodiment, during the so-called leveling operation, the boom-up fine operation and the stick-in fine operation are performed. When the bucket-in and bucket-in fine operations are performed at the same time, pump flow control different from the pump flow control in the normal negative flow control is performed.

Next, the pump flow control in the case where the boom-up fine operation, the stick-in fine operation, and the bucket-in fine operation are simultaneously performed during the leveling work, which is a feature of the control device and the control method of the construction machine according to the present embodiment. Will be described.

Here, FIG. 1 is a control block diagram for explaining the pump flow rate 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 boom-up fine operation determining means (boom fine operation determining means) 2, a stick-in fine operation determining means (stick fine operation determining means) 3, and a bucket. It is configured to include a toe fine operation determination means (bucket fine operation determination means) 4 and a pump tilt angle control means 5.

Among them, the boom-up fine operation determining means 2 determines whether or not the boom-up fine operation has been performed based on an electric signal corresponding to the operation amount of the boom operation member 54a, and determines the result of the pump operation. A signal is output to the tilt angle control means 5.

The stick-in fine operation determining means 3 determines whether or not the fine operation of the stick-in has been performed based on an electric signal corresponding to the operation amount of the stick operating member 54, and determines the pump tilt angle control based on the determination result. A signal is output to means 5. The bucket-in fine operation determination means 4 determines whether or not the bucket-in fine operation has been performed based on an electric signal corresponding to the operation amount of the bucket operating member 54c, and determines the pump tilt angle control means based on the determination result. It outputs a signal to 5.

The pump tilt angle control means 5 includes a boom-up fine operation, a stick-in fine operation, and a bucket based on signals from the boom-up fine operation determination means 2, the stick-in fine operation determination means 3, and the baguette-in fine operation determination means 4. When it is determined that the fine operation is performed simultaneously, the operation member for boom 54 a, the operation member for stick 54 b and the operation member for bucket 54 c are set so that the optimum pump flow rate in this operation pattern is obtained. The pump tilt angles of the hydraulic pumps 51 and 52 are controlled based on an electric signal corresponding to the operation amount of the pump.

Specifically, in the present embodiment, the pump displacement angle control means 5 controls the displacement angles of the hydraulic pumps 51 and 52 as follows.

The pump tilt angle control means 5 basically controls the tilt angles of the hydraulic pumps 51 and 52 by negative flow control.

In this negative flow control, when the boom operating member 54a, the stick operating member 54b, and the bucket operating member 54c are operated, these operating members 54a, 54b, 54c The amount of movement of each control valve 58 to 60, 64, 65 is controlled in accordance with the operation amount of the cylinder, and the boom drive hydraulic cylinder 105, the stick drive hydraulic cylinder 106, and the bucket drive Since the hydraulic oil is supplied to the hydraulic cylinder 107, the pressure of the hydraulic oil downstream of each of these control valves 58 to 60, 64, 65 (in the bypass passages 61b, 66c) The pressure of the hydraulic oil) decreases, and this pressure is detected by the pressure sensors 74 and 75 and used in negative flow control, and the tilt angles of the hydraulic pumps 51 and 52 are increased so that the pump discharge flow rate increases. Is controlled It is.

For this reason, the boom-up fine operation, the stick-in fine operation, and the bucket-in fine operation are performed at the same time. In the case of so-called leveling work, the hydraulic pumps 51, 52 are operated so that the excessive pump discharge flow rate is obtained. The tilt angle control is performed. Therefore, in the present embodiment, the pump tilt angle control means 5 determines that the boom-up fine operation, the stick-in fine operation, and the packet-in fine operation have been performed at the same time. , Boom operation member 54a, stick operation member 54b, and bucket operation member 54c based on electric signals from the stick operation member 54b and the bucket operation member 54c. The pump tilt angles of the hydraulic pumps 51 and 52 are controlled so that the pump discharge flow rate decreases in accordance with the operation amount of the pump.

In this way, when the pump tilt angle control of the hydraulic pumps 51 and 52 is performed, for example, the boost pressure (the differential pressure between the pump discharge pressures of the hydraulic pumps 51 and 52 and the load pressure) becomes a predetermined pressure ( Approximately 100 kgf Z cm ² ). For this reason, a predetermined pressure than the pump discharge pressure is the load pressure (approximately 1 0 0 kgf / cm ²⁾ becomes higher as the boom operation member 5 4 a, 5 4 b the stick operation member and the bucket preparative operation member The pump tilt angle control may be performed based on an electric signal from 54c.

In order to ensure the simultaneous operability of the boom 103, the stick 104, and the baguette 108, the pressure of the hydraulic oil discharged from the hydraulic pumps 51, 52 must be controlled by these working machines. It is necessary to set so that it becomes the maximum pressure (maximum pressure value) of the operation pressure of 1 18. For this reason, the control flow of the negative flow control described above is also increased by slightly increasing the pump discharge flow rate from the total flow rate of the hydraulic oil supplied to each cylinder 105 to 107, thereby reducing the excess pump discharge flow rate to each control valve. To increase the pressure It is set to let.

On the other hand, the pump tilt angle control means 5 is based on signals from the boom-up fine operation determination means 2, the stick-in fine operation determination means 3, and the bucket-in fine operation determination means 4, and performs boom-up fine operation and stick-in fine operation. If it is determined that the bucket and the bucket-in micro-operation are not performed at the same time, the other operation of operating the boom 103, the stick 104 and the bucket 108 without performing the micro-operation is performed. As one example, the pump flow rate of the hydraulic pumps 51 and 52 is controlled so that the optimum pump flow rate in a normal negative flow control is obtained.

Here, the normal negative flow control means that, as described above, the control valves 57 to 60 and 62 to 65 operate according to the operation amounts of the operation members 54 and the bypass oil passage 6. The pressure (negative control pressure) generated by the change in the flow rate of the hydraulic oil of 1b, 66c is detected by the pressure sensors 74, 75, and the pump tilt angle of the hydraulic pumps 51, 52 To control the pump flow rate. In this case, the pump tilt angle control based on the electric signals from the boom operation member 54a, the stick operation member 54b, and the bucket operation member 54c is not performed.

In this way, when the pump tilting angle control of the hydraulic pump 5 1, 5 2 is performed, for example, the boost pressure becomes a predetermined pressure (about ^{1 5 0~2 0 0 kgf / /} cm 2). Therefore, the pump discharge pressure is higher than the load pressure by a predetermined pressure (approximately

150 to 200 kgf / cm ² ) It is also possible to control the pump tilt angle so that it becomes higher.

Here, in the negative flow control, the required pump flow rate is different depending on the difference of the lever pattern and the operation amount.

For example, as a difference in the operation pattern of the operation member 54, when the boom-up and the stick-out are linked, the boost pressure becomes a predetermined pressure (about 20 O kgf / cm ² ). When the boom-up and the bucket are linked, the pump flow should be such that the boost pressure becomes a predetermined pressure (about 150 kgf / cm ² ).

On the other hand, differences in the operation amount of the operation member 54 include, for example, a boom-up fine operation, a stick-in operation (approximately 50% to 100% of the total operation amount), and a bucket-in operation (all operations). (Operation of about 50% to 100% of the volume) is equivalent to excavation using stick 104 and bucket 108, and the pump discharge pressure is balanced with the excavation load. The applied pressure is reached. In this case, since no boost pressure is generated, a pump flow rate corresponding to the operation amount of the operation member 54 is supplied to secure productivity.

The control device for a construction machine according to the present embodiment is configured as described above, and operates as shown in the flowchart of FIG. 7 to perform optimal pump flow rate control (control method) during so-called leveling work.

That is, in step A10, the electric signal from each operation member 54 is read, and the process proceeds to step A20.

In step A20, the boom-up fine operation determining means 2 determines whether or not the boom-up fine operation has been performed based on the operation amount of the boom operating member 54a.

As a result of the determination, when it is determined that the boom-up fine operation has been performed, the process proceeds to step A30, and the stick-in fine operation determining means 3 determines whether the stick-in fine operation has been performed based on the operation amount of the stick operating member 54b. It is determined whether a fine operation has been performed.

As a result of the determination, when it is determined that the stick-in fine operation has been performed, the process proceeds to step A40, and the bucket-in fine operation determining means 4 further performs the bucket-in operation based on the operation amount of the bucket operating member 54c. It is determined whether or not the fine operation of the bucket has been performed. If it is determined that the operation has been performed, the flow proceeds to step A50, and the boom-up fine operation, the stick-in fine operation, and the bucket-in fine operation are simultaneously performed. The boom operating member 54a, the stick operating member 54b and the bucket operating member 5 are controlled by the control means 5 so that the optimum pump flow rate during the leveling work (at the time of fine operation of the boom, stick and bucket) is obtained. 4 Perform pump tilt angle control according to the operation amount of c and return.

On the other hand, if it is determined in step A20 that the fine boom-up operation has not been performed by the fine boom-up operation determining means 2, the stick-in fine operation determining means 3 does not perform the fine-in-stick operation in step A30. When it is determined that the bucket-in fine operation has not been performed by the bucket-in fine operation determination means 4 in step A40, it is determined that the leveling work has not been performed in any case. Judgment proceeds to step A60, where the pump tilt angle control is performed so that the optimum pump flow rate in normal negative flow control is obtained, and the routine returns.

Here, the table below shows the measurement results of fuel efficiency when the optimal pump flow control is performed during the leveling operation. The table shows the measurement results when the leveling operation (leveling operation) was performed for 10 cycles.

As shown in this table, when the optimum pump flow control in this embodiment is performed, the fuel consumption during leveling work is reduced by about 2 times compared to the conventional pump flow control. It can be seen that it can be improved by 5%. It should be noted that the fuel consumption when the packet operation member 54c ゃ stick operation member 54b is fully operated is almost the same as the conventional case.

Therefore, according to the present embodiment, the boom-up fine operation and the stick-in fine operation are performed based on the operation amounts of the boom operation member 54a, the stick operation member 54b, and the bucket operation member 54c. If the bucket-in fine operation is performed at the same time, it is determined that the operation is a so-called leveling operation. In order to control the tilt angles of the hydraulic pumps 51 and 52 so that the optimum pump flow rate is obtained in the leveling operation, the hydraulic pressure is controlled. There is an advantage that the output loss of the engine 50 that drives the pumps 51 and 52 can be suppressed, and consequently fuel efficiency can be improved.

Further, based on the operation amounts of the boom operation member 54a, the stick operation member 54b, and the bucket operation member 54c, the boom-up fine operation, the stick-in fine operation, and the bucket-in fine operation are simultaneously performed. In this case, it is determined that the operation is a leveling operation, and the operating member for boom 54 a, the operating member for stick 54 b and the operating member for bucket 54 are used so that the pump discharge pressure does not excessively increase. In order to control the tilt angles of the hydraulic pumps 51 and 52 according to the operation amount of c, that is, to control the tilt angles of the hydraulic pumps 51 and 52 so as to reduce the pump discharge flow rate, There is an advantage that the output loss of the engine 50 that drives the pumps 51 and 52 can be suppressed, and consequently fuel efficiency can be improved.

In the above embodiment, the case where the boom-up fine operation, the stick-in fine operation, and the bucket-in fine operation are performed has been described. However, the present invention is not limited to this, and the boom-down fine operation (boom fine operation), The present invention is similarly applicable to the case where stick-out fine operation (stick fine operation) and packet open fine operation (bucket fine operation) are performed. Can be used.

In this case, the boom fine operation determining means 2 is configured to determine whether the boom down fine operation has been performed based on the operation amount of the boom operating member 54a, and the stick fine operation determining means 3 The bucket fine operation determining means 4 is configured to determine whether or not the fine operation of the stick is performed based on the operation amount of the stick operating member 54b, and the bucket fine operation determining means 4 is used for the operation of the bucket operating member 54c. It is configured to determine whether the bucket open fine operation has been performed based on this. The pump tilt angle control means 5 determines the tilt angles of the hydraulic pumps 51, 52 based on the determination results of the boom fine operation determination means 2, the stick fine operation determination means 3, and the bucket fine operation determination means 4. Control will be performed.

Further, in the above-described embodiment, the case where the present invention is applied to the control device and the control method of the construction machine that performs the negative flow control is described. However, the present invention is applied to the control device of the construction machine that performs the positive flow control. You may. Industrial applicability

INDUSTRIAL APPLICABILITY As described above, the control device and the control method for a construction machine of the present invention are useful for a construction machine (for example, a hydraulic shovel) that performs a leveling operation by finely operating a boom, a stick, and a bucket. It is suitable for construction machinery that supplies hydraulic oil discharged by an engine-driven hydraulic pump during a hydraulic work to drive work machines (booms, sticks, and buckets).

Claims

The scope of the claims

1. A hydraulic pump (51), (52) for discharging hydraulic oil in the tank, and a plurality of operating members (54) operated by an operator;

Control means (1) for controlling a discharge flow rate from the hydraulic pump, wherein the control means (1) comprises:

Boom fine operation determining means (2) for determining whether a boom fine operation has been performed based on the operation amount of the boom operating member (54a) of the plurality of operating members (54);

Stick fine operation determining means (3) for determining whether or not a stick fine operation has been performed based on the operation amount of the stick operating member (54b) of the plurality of operating members (54);

Bucket fine operation determining means (4) for determining whether a bucket fine operation has been performed based on the operation amount of the bucket operating member (54c) of the plurality of operating members (54);

A pump for controlling the tilt angle of the hydraulic pump based on the determination results of the boom fine operation determining means (2), the stick fine operation determining means (3) and the bucket fine operation determining means (4). A control device for a construction machine, comprising: a tilt angle control means (5).

2. The above-mentioned plural operation members (54) force are configured to output an electric signal according to the operation amount,

The control means (1) performs tilt angle control of the hydraulic pumps (51) and (52) based on electric signals from the plurality of operating members (54). 2. The control device for a construction machine according to claim 1, wherein

3. The boom fine operation determination means (2) Force is configured to determine whether a boom up fine operation has been performed,

The fine stick operation determining means (3) is configured to determine whether a fine stick-in operation has been performed,

The bucket fine operation determining means (4) is configured to determine whether a force bucket-in fine operation has been performed,

The pump tilt angle control means (5) is controlled by the boom fine operation determining means (2), the stick fine operation determining means (3) and the bucket fine operation determining means (4) to perform a boom up fine operation. When it is determined that the stick-in fine operation and the bucket-in fine operation have been performed, the operation member for boom (54a), the operation member for stick (54b), and the operation member for bucket (54c) are used. 3. The control device for a construction machine according to claim 2, wherein tilt angle control of said hydraulic pumps (51), (52) is performed in accordance with said electric signal.

4. The boom fine operation determining means (2) is configured to determine whether a boom up fine operation has been performed,

The stick fine operation determining means (3) is configured to determine whether a stick-in fine operation has been performed,

The pump tilt angle control means (5) is operated by the boom fine operation determining means (2), the stick fine operation determining means (3) and the bucket fine operation determining means (4) to perform a boom up fine operation. When it is determined that the stick-in fine operation and the bucket-in fine operation have been performed, the discharge flow rate from the hydraulic pumps (51) and (52) is set to the value when one of the fine operations is not a fine operation. Hydraulic pump (51), (52) The control device for a construction machine according to claim 1, wherein the tilt angle control of the pressure pumps (51) and (52) is performed.

5. Hydraulic pumps (5 1) and (5 2) for discharging hydraulic oil in the tank, and a plurality of operating members (54) operated by the operator,

A control means (1) for controlling a discharge flow rate from the hydraulic pump.

A boom fine operation determining step of determining whether a boom fine operation has been performed based on the operation amount of the boom operating member (54a) of the plurality of operating members (54); A stick fine operation determining step of determining whether a stick fine operation has been performed based on the operation amount of the stick operating member (54b) of (54); and a stick fine operation determining step of the plurality of operating members (54). A bucket fine operation determining step of determining whether a bucket fine operation has been performed based on the operation amount of the baguette operating member (54c);

Controlling the tilt angle of the hydraulic pump based on a result of the determination in the determining step.

6. In the control step, tilt angle control of the hydraulic pumps (51), (52) is performed based on an electric signal corresponding to an operation amount of the plurality of operation members (54). 6. The method for controlling a construction machine according to claim 5, wherein

7. In the boom fine operation determination step, it is determined whether a boom up fine operation has been performed.

In the stick fine operation determination step, it is determined whether a stick-in fine operation has been performed. In the bucket fine operation step, it is determined whether bucket-in fine operation has been performed.

In the control step, when it is determined that the boom-up fine operation, the stick-in fine operation, and the bucket-in fine operation are performed in the determination step, the boom operation member (54a) and the stick operation member (54) b) and the tilt angle control of the hydraulic pumps (51) and (52) according to an electric signal from the packet operating member (54c). 6. The method for controlling a construction machine according to item 6.

8. In the boom fine operation determination step, it is determined whether a boom up fine operation has been performed.

In the stick fine operation step, it is determined whether a stick-in fine operation has been performed.

In the bucket fine operation step, it is determined whether the bucket-in fine operation has been performed, and

In the control step, when it is determined in the determination step that the boom-up fine operation, the stick-in fine operation, and the bucket-in fine operation have been performed, the discharge flow rate from the hydraulic pumps (51) and (52) is determined. When any of the above fine operations is not a fine operation, the tilt angle control of the hydraulic pumps (51) and (52) is reduced so as to reduce the discharge flow from the hydraulic pumps (51) and (52). 6. The method for controlling a construction machine according to claim 5, wherein the control is performed.