KR101693822B1 - hydraulic control system for construction machine - Google Patents

Abstract

The present invention provides a hydraulic system for the control of a construction machine, which comprises: a first hydraulic line guiding the movement of hydraulic oil, pumped from a first pump, to a first connection passage and a first driving motor via a first driving spool; a second hydraulic line guiding the movement of hydraulic oil, pumped from a first pump, to a second connection passage and a second driving motor via a second driving spool; a third hydraulic line guiding the movement of hydraulic oil, pumped from a third pump, to a hydraulic oil tank via an open center operation spool for the operation of an assisting device; a joining valve installed on a duct of the third hydraulic line, and making the hydraulic oil moved to a third connection passage to be collected from the third hydraulic line into the hydraulic oil tank; a joining line joining the first, second, and third connection passages, and guiding the movement of hydraulic oil flowed through each of the connection passages; and a guide line guiding the hydraulic oil, moved along the joining line, to a load sensing operation spool for the operation of a front device. As such, the present invention is capable of preventing a speed change, caused by a change of a load on each actuator of the front device for main work, while guaranteeing the linearity of driving, and maximizing working efficiency by optimally distributing oil supplied from each of the pumps.

Description

Technical Field [0001] The present invention relates to a hydraulic control system for a construction machine,

The present invention relates to a hydraulic system, and more particularly, to a hydraulic system that prevents a speed change due to a change in a load applied to each actuator of a front device corresponding to a main operation while ensuring the straightness of travel during a running operation, And more particularly, to a hydraulic system for controlling a construction machine according to a new type that maximizes work efficiency by optimally distributing a flow rate.

Generally, a hydraulic circuit of a flow distribution device applied to a construction machine such as an excavator is configured to drive a left traveling motor and a right traveling motor, and to drive a boom, an arm, a bucket or the like.

In the case of the hydraulic circuit in the running straight type, among these hydraulic circuits, the pressurized oil discharged from the first pump is recovered to the pressurized tank through the one-way traveling boom spool, the bucket spool and the arm spool via the running straight spool of the main control valve, The spool of the main control valve is returned to the pressurized tank through the opposite side running spool, the arm spool, the boom and the unidirectional option spool through the running straight spool of the main control valve, and the pressurized oil discharged from the third pump is returned to the dozer spool, And is recovered to the pressurized oil tank via the boom spool.

In the above-described traveling straight-ahead hydraulic circuit, when the working device is operated alone, the flow rate supplied to each spool is supplied through the serial flow path and the parallel flow path, while the combined flow of the two-way traveling and one or more other devices The direct-drive spool is switched by the logic of the signal line supplied from the pilot pump, and the serial flow path supplied to the other device is supplied only to the running straight spool and is shut off, and the parallel flow path through the orifice flow path of the running straight spool . Therefore, in the case of the boom and the arm, the second control spool has a problem that the smooth controllability in the minute control section can be ensured by having the second spool, but the outer shape of the main control valve becomes large due to the second spool of each of the boom and the arm.

In addition, the above-described traveling rectilinear hydraulic circuit has an advantage in that it can transmit sufficient power to traveling and each working device when the traveling and other working devices are interlocked. However, since only the first and second pumps are used, There is a problem that the speed change amount is larger than that of the traveling independent type flow distribution device during the single operation.

In the traveling independent hydraulic circuit, the pressure oil discharged from the first pump is recovered to the pressure oil tank through the boom spool and the bucket spool through the one-way traveling spool of the main control valve, and the pressure oil discharged from the second pump is recovered from the main control valve And is recovered to the pressure oil tank via the arm spool and the selector spool via the opposite side running spool.

This traveling independent hydraulic circuit supplies the pressurized oil supplied from the third pump to the boom spool and the arm spool through the selector valve for joining the boom spool and the arm spool, so that the second spool in the straight running type flow distributing device The energy saving effect and the speed change of each working device occurring during the interlocking operation are also made straightforward by using the flow rate of the third pump which is not used when the traveling and the working device are interlocked and which is recovered to the pressure oil tank. Type hydraulic circuit.

However, only when the selector spool is switched, the discharge pressure oil of the third pump can be transmitted to the main control valve of the first pump enema and the main control valve of the second pump enema, and the switching condition of the selector spool is also changed The signal lines must be formed up to the spools, i.e., the traveling spools on both sides, the boom spools, the arm spools, and the bucket spools, which increases the size of the main control valve and raises production costs.

10-1517240, 10-169878, 10-0518748, 10-0406277, 1995-0002377, and 10-1157267

SUMMARY OF THE INVENTION The present invention has been made in order to solve various problems of the prior art described above, and it is an object of the present invention to provide a front- And to provide a hydraulic system for controlling a construction machine according to a new type that can maximize work efficiency by distributing the flow rate supplied from each pump in an optimal manner.

In order to accomplish the above object, according to the present invention, there is provided a hydraulic system for controlling a construction machine, comprising: a first hydraulic line for guiding a flow of pressurized oil pumped from a first pump to a first traveling motor and a first connecting passage through a first traveling spool; ; A second hydraulic line for guiding the flow of the pressurized fluid pumped from the second pump to flow through the second traveling spool to the second traveling motor and the second connecting passage; A third hydraulic line for guiding the flow of the pressurized fluid pumped from the third pump to be recovered to the pressurized tank through the open center operation spool for auxiliary equipment for operation of the auxiliary equipment; A merging valve installed on a channel of the third hydraulic line for allowing the hydraulic fluid flowing from the third hydraulic line to be recovered to the pressure oil tank to flow through the third connection channel; A joining line for guiding the flow of the pressurized oil flowing through each of the connection flow paths while joining the first connection flow passage, the second connection flow passage and the third connection flow passage respectively; And a guide line for guiding the pressurized fluid flowing along the merging line to a load sensing operation spool for the front device for operation of the front device, respectively.

Here, the front device includes at least one of a boom, an arm, and a bucket, and each load sensing operation spool for each front device includes at least one of a boom spool, an arm spool, and a bucket spool, The load sensing operation spool is provided with a pressure compensator, and each of the pressure compensators is connected to a pump load sensing unit, and the discharge flow rates of the first pump and the second pump are variable based on the pressure oil load supplied from the respective pressure compensators So that the feedback signal is provided.

An operation signal line for receiving signals related to the operations of the first traveling spool and the second traveling spool is connected to the control line on which the control signal of the merging valve is provided.

An operation signal line for receiving a signal related to the operation of the first traveling spool, the second traveling spool, and the load sensing operation spool for each front device is connected to a control line provided with a control signal of the merging valve. do.

A first operation signal line for receiving a signal related to the operation of the first traveling spool and the second traveling spool is provided on a control line provided with a control signal of the merging valve, And a second operation signal line for receiving a signal related to the operation of the load sensing operation spool for each front device.

As described above, the hydraulic system for controlling a construction machine according to the present invention has the effect that stable operation of the auxiliary equipment and the front equipment can be performed while ensuring the straightness of traveling regardless of the operation type.

Particularly, the hydraulic system for controlling a construction machine according to the present invention simplifies the entire structure and has various effects as well as reducing the size of the overall system.

BRIEF DESCRIPTION OF THE DRAWINGS Fig. 1 is a schematic diagram of a hydraulic circuit for illustrating a hydraulic system for controlling a construction machine according to an embodiment of the present invention. Fig.
FIGS. 2 to 4 are diagrams for explaining the operation of the hydraulic system for controlling a construction machine according to the embodiment of the present invention,
Fig. 5 is a diagram showing a hydraulic circuit diagram for explaining another embodiment of a hydraulic system for controlling a construction machine according to the present invention. Fig.
Fig. 6 is a schematic diagram of a hydraulic circuit diagram for explaining another embodiment of a hydraulic system for controlling a construction machine according to the present invention. Fig.

DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS Hereinafter, a preferred embodiment of a hydraulic system for controlling a construction machine according to the present invention will be described with reference to FIGS. 1 to 6 attached hereto.

FIG. 1 is a hydraulic circuit diagram illustrating a hydraulic system for controlling a construction machine according to a preferred embodiment of the present invention.

As shown in these drawings, a hydraulic system for controlling a construction machine according to an embodiment of the present invention includes a first hydraulic line 100, a second hydraulic line 200, a third hydraulic line 300, (400), a merging line (500), and a plurality of guide lines (610, 620, 630).

This will be described in more detail below for each configuration.

First, the first hydraulic line 100 is a conduit in which the flow of pressurized oil pumped from the first pump 110 is involved in running in one direction.

One end of the first hydraulic line 100 is connected to the first pump 110 to be supplied with the pressurized oil pumped from the first pump 110 and the other end is connected to the first traveling spool 120 .

Here, the first traveling spool 120 provides selective pressure to the first traveling motor 130 for running in one direction or the first connecting flow path 140 for guiding the flow of the recovered pressing oil The pressure oil recovered through the first connection passage 140 may be surplus pressure oil other than the pressure oil supplied for driving the first traveling motor 130 or may be a surplus pressure oil for the first traveling motor 130, 1 < / RTI > pump < RTI ID = 0.0 > 110 < / RTI >

Next, the second hydraulic line 200 is a conduit in which the flow of the pressurized oil pumped from the second pump 210 is involved in traveling in the other direction.

One end of the second hydraulic line 200 is connected to the second pump 210 to be supplied with the pressurized oil pumped from the second pump 210 and the other end is connected to the second traveling spool 220 .

Here, the second traveling spool 220 provides selective pressure to the second traveling motor 230 for traveling in the other direction or the second connecting flow path 240 for guiding the flow of the recovered pressing oil And the pressure oil recovered through the second connection passage 240 may be surplus pressure oil other than the pressure oil supplied for driving the second traveling motor 230 or may be a surplus pressure oil for the second traveling motor 230, 2 pump 210, as shown in FIG.

Meanwhile, in the embodiment of the present invention, the first traveling motor 130 is a hydraulic motor for traveling in the leftward direction, and the second traveling motor 230 is a hydraulic motor for traveling in the rightward direction .

The first pump 110 and the second pump 210 are made of a flow rate variable pump so that the pumping flow rate of the pressurized oil is changed according to a load required when the front device 700 is operated.

Next, the third hydraulic line 300 is a flow path for guiding the flow of the pressure oil pumped from the third pump 310.

One end of the third hydraulic line 300 is connected to the third pump 310 so as to be supplied with the pressurized oil pumped from the third pump 310 and the other end is connected to the operation of the auxiliary device 800 And is connected to the open center operation spool 801 for at least one auxiliary machine and is connected to the pressurized oil tank 320 so that the pressurized oil can be recovered.

Here, the auxiliary device 800 may include at least one of a hydraulic motor 810 for swinging operation and an actuator 820 for operating the doser, and the open center operation spool 801 for the auxiliary device may include at least one of the hydraulic motor 810, At least one of a swing spool 811 for selectively supplying the hydraulic fluid to the hydraulic motor 810 and a doser spool 821 for selectively supplying the hydraulic fluid to the actuator 820 is included.

The auxiliary device 800 includes the hydraulic motor 810 and the actuator 820 for the operation of the doser and the open center operation spool 801 for the auxiliary device includes the swing spool 811 and the dozer 810. [ And a spool 821 as an example. Of course, although not shown, the auxiliary device 800 further includes an actuator for a boom swing, and the open center operation spool 801 for the auxiliary apparatus may further include a boom swing spool.

Meanwhile, the third pump 310 for supplying pressure oil to the third hydraulic pressure line 300 is constituted by a quantitative pump configured to supply only a predetermined amount of the pressurized oil.

Next, the merging valve 400 is a direction switching valve that allows the pressurized oil flowing from the third hydraulic line 300 to be returned to the pressurizing tank 320 to flow into the third connecting passage 340 as needed.

The merging valve 400 is installed on a pipeline that passes through the swinging spool 811 and the doser spool 821 in the pipeline of the third hydraulic line 300, Hydraulic oil flowing along the third hydraulic line 300 by the operation is involved in the operation of at least one of the swing spool 811 and the dozer spool 821 and then the pressure oil tank 320, (340). ≪ / RTI >

At the same time, the converging valve 400 is made to receive a control signal for its operation via the control line 920.

On the other hand, the reference numeral 410 is a fourth pump for providing a pressure signal to the control line 920.

Next, the confluence line 500 is a flow path while guiding the pressurized fluid recovery flow.

The joining line 500 is connected to the first connection passage 140, the second connection passage 240 and the third connection passage 340 through the connection passages 140, 240 and 340, So as to collectively guide the flow.

Next, the guide lines 610, 620 and 630 guide the pressure oil flowing along the merging line 500 to at least one or more front-side load sensing operation spools 701 for operation of the front device 700 .

The front device 700 includes at least one of a boom 710, an arm 720 and a bucket 730. The front load sensing operation spool 701 for each front device includes a boom spool 711, An arm spool 721 and a bucket spool 731. [

In addition, the load sensing operation spool 701 for each front device is provided with pressure compensators 712, 722 and 732, and the pressure compensators 712, 722 and 732 are connected to the pump load sensing unit 740, The feedback signal is provided so that the discharge flow rate of the first pump 110 and the second pump 210 can be varied.

On the other hand, on the control line 920 to which the control signal to the merging valve 400 is supplied, the first and second traveling spools 120 and 220 are operated, The pressure signal is connected to the pressurized oil tank 320 through the control signal line 920 and the operation signal line. That is, the hydraulic fluid discharged from the third pump 310 is not connected to the third hydraulic line 300, the junction valve 400, and the seizing tank 320, .

Meanwhile, when the first and second traveling spools 120 and 220 are operated, the pressure signal generated by the fourth pump 410 is connected to the combined valve 400 through the control line, Line 930 is disconnected. That is, the pressure signal is transmitted to the junction valve 400 to switch the valves, and the pressurized fluid discharged from the third pump 310 flows into the third hydraulic line 300, the third connection channel 340, A connected circuit is constructed.

Hereinafter, the operation of the hydraulic system for controlling a construction machine according to the embodiment of the present invention described above will be described in more detail.

First, FIG. 2 shows the flow of pressurized oil during running operation.

That is, when the first pump 110 and the second pump 210 are pumped, the pumped oil pumped by the pumping operation of the first pump 110 is supplied to the first hydraulic line 100, The hydraulic oil pumped by the pumping operation of the second pump 210 is supplied to the first traveling motor 130 via the first traveling spool 120 along the second hydraulic line 200, Passes through the spool 220 and is supplied to the second traveling motor 230.

That is, the pressure oil provided by the first pump 110 and the second pump 210 is only involved in running, thereby ensuring the straightness of running.

Of course, surplus pressure oil that can not be supplied to the traveling motors 130 and 230 among the pressurized oil supplied by the first pump 110 and the second pump 210 may flow through the first connection passage 140 or the second connection passage 240 To the confluent line 500. [0043]

Next, Fig. 3 shows the pressurized oil flow when the running operation and the operation of the front device are simultaneously performed.

That is, in the combined operation in which the running operation and the operation of the front device 700 are combined, the first pump 110 and the second pump 210 are pumped, The hydraulic fluid pumped by the operation is supplied to the first traveling motor 130 through the first traveling spool 120 along the first hydraulic line 100 and is pumped by the pumping operation of the second pump 210 The pressurized oil is supplied to the second traveling motor 230 through the second traveling spool 220 along the second hydraulic line 200 and is supplied to the second traveling motor 230. The pressure oil supplied by the first pump 110 and the second pump 210 Surplus pressure oil that can not be supplied to each of the traveling motors 130 and 230 is supplied to the merging line 500 through the first connection passage 140 or the second connection passage 240. At this time, the operation of the merging valve 400 is performed, and the pumped fluid pumped by the pumping operation of the third pump 310 is supplied to the merging line 500 through the third connecting flow path 340.

Therefore, the front device 700 can be smoothly operated by surplus pressure oil supplied from the first pump 110 and the second pump 210, and pressure oil supplied from the third pump 310.

Particularly, when the front device 700 operates, the pressure compensators 712, 722 and 732 provided in the respective operation spools 711, 721 and 731 can maintain a constant pressure. The pressure compensators 712, 740 to provide a feedback signal so that the discharge flow rate of the first pump 110 and the second pump 210 can be varied based on the pressure of oil supplied from the pressure compensators 712, So that a sufficient flow rate can be distributed to maintain the working speed at a constant level.

Next, Fig. 4 shows the flow of the pressurized oil when the auxiliary device 800 is operated.

That is, when operation of the auxiliary device 800 is performed, the compressed fluid pumped by the pumping operation of the third pump 310 is supplied to the auxiliary device 800, whereby the first pump 110 and the second pump The operation of the auxiliary device 800 can be smoothly performed while ensuring the straightness of travel as the supply of the pressurized oil to the auxiliary device 800 is performed irrespective of the running operation of the auxiliary device 800. [

As a result, in the hydraulic system for controlling a construction machine according to the present invention, hydraulic pressure is supplied only to the respective traveling motors 130 and 230 from the first pump 110 and the second pump 210 when the traveling alone operation is performed, Hydraulic oil is supplied to the traveling motors 130 and 230 from the first pump 110 and the second pump 210 and the hydraulic oil recovered through the first connection passage 140 and the second connection passage 240 and the third pump 310, The pressurized oil recovered through the third connection passage 340 by the operation of the first and second connection passages 340 and 340 is joined to the confluence line 500 and then flows to the guide lines 610, 620 and 630 so that the operation of the front device 700 can be performed in a complex manner The swinging spool 811 or the doser spool 821 is supplied with the oil pressure through the third pump 310 when the swing or the dozer is operated so that the driving straightness can be assured and the auxiliary equipment 800 The stable operation of the front device 700 becomes possible.

Particularly, the hydraulic system for controlling a construction machine according to the present invention simplifies the entire structure, so that various modifications can be made and the overall system size can be reduced.

That is, in the case of Japanese Patent Application No. 10-1157267, a running straight control spool is additionally used to perform the same function as the hydraulic system for controlling a construction machine according to the present invention. However, in the present invention, Functions can be performed, thereby simplifying the entire structure and minimizing the size.

On the other hand, the hydraulic system for controlling a construction machine of the present invention is not limited to the structure of the above-described embodiment.

5, the operation signal line 930 is connected to the first and second traveling spools 120 and 220, as well as to the operation of the load sensing operation spools 701 for the respective front apparatuses The operation signal line is provided to the first operation signal line 931 and the second operation signal line 932, respectively, as shown in FIG. 6, and the first operation signal line 931 Is connected to receive signals related to the operations of the first and second traveling spools 120 and 220 and the second operating signal line 932 is connected to the front load sensing operation spools 701 May be connected to receive only signals related to the operation of the mobile terminal 100 so as to give a change according to various operation modes.

As described above, the hydraulic system for controlling a construction machine of the present invention is a useful invention that can be modified in various ways.

100. First hydraulic line 110. First pump
120. First traveling spool 130. First traveling motor
140. First connection line 200. Second hydraulic line
210. Second pump 220. Second travel spool
230. Second traveling motor 240. Second connecting channel
300. Third hydraulic line 310. Third pump
320. Pressure oil tank 340. Third connection channel
400. Combination valve 410. Fourth pump
500. Confluence line 610, 620, 630. Guide line
700. Front unit 701. Load sensing operation spool for front unit
710. Boom 720. Arm
730. Bucket 711. Boom spool
721. Arm spools 731. Bucket spools
712, 722, 732. Pressure compensator 740. Pump load sensing section
800. Auxiliary equipment 801. Open center operation spool for auxiliary equipment
810. Hydraulic motor 820. Actuator
811. Swing spool 821. Dozer spool
920. Control line 930. Operation signal line
931. A first motion signal line 932. A second motion signal line

Claims (5)

A first hydraulic line 100 for guiding the flow of pressure oil pumped from the first pump 110 to flow through the first traveling spool 120 to the first traveling motor 130 and the first connecting flow path 140;
A second hydraulic line 200 for guiding the flow of the pressure oil pumped from the second pump 210 to flow through the second traveling spool 220 to the second traveling motor 230 and the second connecting flow path 240;
The third hydraulic line 300 for guiding the flow of the pressurized oil pumped from the third pump 310 to the pressurized oil tank 320 through the open center operation spool 801 for auxiliary equipment for operation of the auxiliary device 800, ;
The third hydraulic fluid line 300 is connected to the third hydraulic fluid line 300 through the third hydraulic fluid line 300. The third hydraulic fluid line 300 is connected to the third hydraulic fluid line 300, );
A joining line 500 for guiding the flow of the pressurized oil introduced through each of the connection channels 140, 240 and 340 while joining the first connection channel 140, the second connection channel 240 and the third connection channel 340, ;
And guiding lines 610, 620 and 630 guiding the pressurized fluid flowing along the merging line 500 to the load sensing operation spool 701 for the front device for operation of the front device 700,
The hydraulic pressure is supplied only to the traveling motors 130 and 230 from the first pump 110 and the second pump 210 during the traveling alone operation and from the first pump 110 and the second pump 210 during the traveling complex operation The hydraulic fluid is supplied to the traveling motors 130 and 230 and the hydraulic fluid is recovered through the first connection passage 140 and the second connection passage 240 and the third connection passage 340 are combined to the confluence line 500 and then flowed to the guide lines 610, 620, 630 so that the operation of the front device 700 can be performed in a complex manner. In operation of the auxiliary device 800, Wherein the hydraulic pump is operable to supply the hydraulic oil to the open center operation spool (801) for auxiliary equipment through the third pump (310). The method according to claim 1,
The front device 700 includes at least one of a boom 710, an arm 720 and a bucket 730. The front load sensing operation spool 701 for each front device includes a boom spool 711, (721) and a bucket spool (731)
Each of the pressure compensators 712, 722 and 732 is connected to the pump load sensing unit 740 and is supplied from the respective pressure compensators 712, 722 and 732. The pressure compensators 712, Wherein a feedback signal is provided to vary the discharge flow rate of the first pump (110) and the second pump (210) based on a pressure load of the hydraulic pump. The method according to claim 1,
An operation signal line 930 for receiving signals related to the operations of the first and second traveling spools 120 and 220 is provided on a control line 920 provided with a control signal of the merging valve 400 And a hydraulic system for controlling a construction machine. The method according to claim 1,
A control signal for controlling the operation of the first traveling spool 120, the second traveling spool 220, and the load sensing operation spool 701 for each front device is provided on the control line 920 provided with the control signal of the converging valve 400 And an operation signal line (930) for receiving a signal is connected. The method according to claim 1,
A first operation signal line 931 for receiving signals related to the operations of the first and second traveling spools 120 and 220 is provided on a control line 920 provided with a control signal of the merging valve 400. [ And a second operation signal line 932 for receiving a signal related to the operation of the first traveling spool 120, the second traveling spool 220, and the load sensing operation spool 701 for each front device, And a hydraulic system for controlling a construction machine.

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