WO2015068869A1

WO2015068869A1 - Hydraulic device for construction machine

Info

Publication number: WO2015068869A1
Application number: PCT/KR2013/010083
Authority: WO
Inventors: 정해균; 김성곤
Original assignee: 볼보 컨스트럭션 이큅먼트 에이비; 정해균; 김성곤
Priority date: 2013-11-07
Filing date: 2013-11-07
Publication date: 2015-05-14

Abstract

Disclosed is an invention relating to a hydraulic device for a construction machine, comprising: a boom joining control valve provided between a first hydraulic pump and a hydraulic cylinder for a work device and controlling the joining flow supplied to a boom cylinder during spool conversion; a boom control valve provided between a second hydraulic pump and the boom cylinder and controlling the movement of the boom; a controller electrically connected to an operation lever and outputting a preset control signal at the time of boom-down operation; and a boom-down acceleration control valve outputting pilot signal pressure for converting the spools of the boom joining control valve and the boom control valve during a boom-down operation of the operation lever such that a valve opening amount is controlled according to the control signal applied from the controller.

Description

Hydraulics for Construction Machinery

The present invention relates to a hydraulic device for construction machinery, and more particularly, the flow rate discharged from two hydraulic pumps are joined to the boom cylinder when the operation of the boom in the construction site is joined to the boom cylinder and the speed-up mode switch during the operation of the boom lowering It relates to a hydraulic device for construction machinery that can increase the boom lowering speed by allowing the flow of the boom cylinder to be discharged to the hydraulic tank quickly in accordance with the operation of.

Typically, construction machinery, including excavators or wheel loaders, are utilized for excavation or loading of soil and transfer of materials depending on the work requirements. The work device including the boom, the arm and the bucket is driven by the hydraulic power source, and the movement of the work device is controlled to meet the work demand by the operator's operation.

In particular, the boom moves to raise and lower the pivotally connected arm and bucket, and the speed of movement is controlled by the flow rate provided to the boom cylinder.

1 is a schematic view of an excavator for explaining the movement of the boom descending at the construction site, Figure 2 schematically shows a conventional hydraulic circuit diagram is driven boom shown in FIG.

1 and 2, a construction machine including an excavator typically includes an engine (not shown) installed inside the engine room 3 and a first hydraulic pump connected to the engine to provide hydraulic pressure. The hydraulic pump P1 or the remote control valve 9 for outputting a pilot signal corresponding to the operation amount of the P1, the second hydraulic pump P2 and the operation lever 8 and the boom 2a for the up and down movement. Between the boom cylinder 5, the first hydraulic pump P1 and the second hydraulic pump P2 and the boom cylinder 5 supplied with hydraulic pressure from P2, according to the operation of the operation lever 9; A hydraulic circuit including a boom control valve 6 and a boom confluence control valve 7 switched by an output pilot signal is provided.

In order to move the boom up and down, a pilot signal is output from the remote control valve 9 corresponding to the operation amount of the operation lever 8, and the pilot signal is boom up or boom down. Is provided for spool switching of the boom control valve 6 or the boom confluence control valve 7 through each

pilot flow passage

1a or 1b.

In particular, during the boom up operation, the boom control valve 6 is spooled to the right in the drawing so that the flow rate discharged from the second hydraulic pump P2 is transferred to the large chamber of the boom cylinder 5 through the supply passage 10b. In addition to being supplied to 5a, the boom confluence control valve 7 is also spooled to the right so that the flow rate discharged from the first hydraulic pump P1 is large through the supply passage 10a of the boom cylinder 5. It is supplied to the chamber 5a. Accordingly, during the boom up operation by the driver at the construction site, the boom rises relatively quickly.

On the other hand, in the boom down operation, the boom control valve 6 is spooled to the left in the drawing so that only the supply flow rate of the second hydraulic pump P2 is supplied to the small chamber 5b of the boom cylinder 5. As a result, the boom has a relatively slow downward movement.

However, the work device including the boom 9 in the construction site, it is necessary to move downward of the construction machine in contact with the ground (H) or to control the downward movement of the boom to the maximum digging depth. In this case, there is a problem that the work efficiency is lowered as the movement section of the boom lowering according to the boom down operation becomes larger.

Therefore, the lowering speed of the boom needs to be controlled more quickly during the boom down operation at the construction site, the conventional hydraulic system is not able to increase the lowering speed of the boom.

As one of the prior arts, Korean Patent Publication No. 2001-0061821 (published on July 7, 2001) discloses a boom lowering speed control device of an excavator. In this prior art, the hydraulic pressure of the large chamber of the boom cylinder is returned to the hydraulic tank through the selector valve. However, this prior art is also limited to increasing the descending speed due to the weight of the boom, there is a disadvantage that can not increase the descending speed of the boom in accordance with the need of construction sites or boom lowering work.

The present invention was created to solve the above problems,

In the construction site, when the boom is raised, the flow rates of the two hydraulic pumps are joined and supplied to the boom cylinder. When the boom is lowered, the boom cylinder flow rate is controlled depending on the speed increase mode so that the construction machine can be quickly discharged to the hydraulic tank. The purpose is to provide a hydraulic device for the purpose.

Another object of the present invention is to provide a hydraulic device for a construction machine that detects a lowering operation of the boom and controls the flow rate of the boom cylinder to be quickly discharged to the hydraulic tank.

One feature of the present invention for solving the above technical problem,

engine;

Work tools including booms, arms and buckets;

First and second hydraulic pumps connected to the engine and supplying hydraulic oil for driving the work device;

A remote control valve for outputting a pilot signal corresponding to the operation amount of the operation lever;

A boom confluence control valve installed between the first hydraulic pump and the hydraulic cylinder for the work device and controlling a confluence flow rate supplied to the boom cylinder when the spool is switched;

A boom control valve installed between the second hydraulic pump and the boom cylinder to control movement of the boom;

A controller electrically connected to the operation lever and outputting a preset control signal during a boom down operation; And

A boom down speed control valve for outputting a pilot signal pressure for switching the boom confluence control valve and the spool of the boom control valve during the boom down operation of the operation lever, the valve opening being controlled by a control signal applied from the controller. It is achieved by providing a hydraulic device for a construction machine comprising a.

According to one embodiment of the invention, the boom down speed control valve is composed of a solenoid valve.

According to another embodiment of the present invention, the boom-down speed control valve is composed of an electromagnetic proportional control valve, the electromagnetic proportional control valve to proportionally control the pilot signal pressure supplied from the pilot pump, accordingly The hydraulic pressure is quickly discharged to the hydraulic tank.

According to the embodiment, a predetermined signal detection sensor is connected to the controller, and the signal detection sensor detects a boom up signal and a boom down signal for the boom confluence control valve and the boom control valve to increase the hydraulic pressure of the boom cylinder. Quickly discharge into the hydraulic tank.

Preferably, the signal detection sensor comprises a pilot signal pressure sensor for spool switching.

In the hydraulic device for a construction machine according to the present invention, a speed increase mode switch for increasing the boom lowering speed is connected to the controller.

Hydraulic apparatus for construction machinery according to the present invention,

If the construction site needs to control the downward movement of the boom down to the ground (H) or to the maximum digging depth, the operator can operate the speed increase mode switch to quickly discharge the flow from the large chamber of the boom cylinder to the hydraulic tank. There is an advantage.

In addition, the hydraulic device for construction machinery according to the present invention, by detecting the lowering operation of the boom, simultaneously controlling the spool switching of the boom control valve and the boom confluence control valve proportionally simultaneously through the boom down speed control valve to increase the flow rate of the boom cylinder It has the advantage of being discharged quickly to the hydraulic tank.

1 is a schematic diagram of an excavator for explaining the movement of the boom descending at the construction site,

FIG. 2 is a conventional hydraulic circuit diagram schematically showing the driving of the boom shown in FIG. 1;

3 is a hydraulic circuit diagram of a hydraulic device for a construction machine according to an embodiment of the present invention;

4 is a hydraulic circuit diagram of a hydraulic device for a construction machine according to another embodiment of the present invention;

Figure 5 is a flow chart illustrating the step of controlling the spool switching of the boom control valve and the boom confluence control valve when operating the speed increase mode switch in accordance with an embodiment of the present invention,

Figure 6 is a flow chart illustrating the step of controlling the spool switching of the boom control valve and the boom confluence control valve when operating the speed increase mode switch in accordance with another embodiment of the present invention,

The terms or words used in this specification and claims are not to be construed as being limited to their ordinary or dictionary meanings, and the inventors may legally define the concept of terms in order to best describe their invention. On the basis of the principle that the present invention should be interpreted as meanings and concepts corresponding to the technical idea of the present invention.

Hereinafter, exemplary embodiments of the present invention will be described in detail with reference to the accompanying drawings.

1 is a schematic diagram of an excavator for explaining the movement of the boom descending in the construction site, Figure 2 is a conventional hydraulic circuit diagram schematically shown to explain the driving of the boom shown in Figure 1, Figure 3 is a view of the present invention 4 is a hydraulic circuit diagram of a hydraulic device for a construction machine according to an embodiment, FIG. 4 is a hydraulic circuit diagram of a hydraulic device for a construction machine according to another embodiment of the present invention, and FIG. 5 is an operation of a speed increase mode switch according to an embodiment of the present invention. Flow chart for explaining the step of controlling the spool switching of the boom control valve and the boom confluence control valve, Figure 6 is a spool switching of the boom control valve and boom confluence control valve during operation of the speed increase mode switch according to another embodiment of the present invention A flow chart describing the steps of controlling the.

Prior to description, reference numeral 1 denotes a pilot pump, 5 denotes a boom cylinder, 9 denotes a remote control valve of an operating lever, 20 denotes a boom confluence control valve, 21 denotes a boom control valve, 22 denotes a controller, and 23 denotes a speed increase mode switch. And 40 are schematic representations of boom down speed control valves.

The hydraulic device for a construction machine according to the present invention is useful for increasing the work efficiency by increasing the speed of the boom down movement by the operator operating the speed increase mode switch in the construction site.

More specifically, referring to FIG. 3, the hydraulic device for a construction machine according to the present invention includes an engine (not shown) mounted inside an engine room 3, a boom 2a, an arm 2b, and a bucket ( A working device 2 including 2c) and first and second hydraulic pumps P1 and P2 connected to the engine and supplying hydraulic oil for driving the working device 2 are included.

Typically, the work device 2 is composed of a plurality of hydraulic cylinders for the work device driven by the hydraulic oil discharged from the first hydraulic pump (P1) or the second hydraulic pump (P2), the first hydraulic pump ( Between the P1) or the second hydraulic pump P2 and the hydraulic cylinder for the work device, a plurality of hydraulic control valves for controlling the start, stop and direction change of the work device 2 may be configured.

For example, as shown in Figure 3, for the operation of the work device 2 for the loading or dumping of the soil, the hydraulic oil discharged from the first hydraulic pump (P1) or the second hydraulic pump (P2) Arm cylinder control valve, bucket cylinder control valve or swing motor control valve may be further connected to be connected to the supply passage (10a or 10b).

Hydraulic device for a construction machine according to the present invention, between the remote control valve 9 for outputting a pilot signal corresponding to the operation amount of the operation lever 8 and the first hydraulic pump (P1) and the hydraulic cylinder for the working device. It is installed between the boom confluence control valve 20 and the second hydraulic pump 21 and the boom cylinder (5) for controlling the flow rate of the flow supplied to the boom cylinder (5) when switching the spool and the boom (2a) It is configured to include a boom control valve 21 for controlling the movement of.

The remote control valve 9 outputs the pilot hydraulic oil supplied from the pilot pump 1 as a pilot signal corresponding to the operation amount of the operation lever 8.

On the other hand, the hydraulic device for a construction machine according to the present invention, the boom down of the controller 22 and the operation lever 8 is electrically connected to the operation lever 8 and outputs a predetermined control signal during the boom down operation. Outputs a pilot signal pressure for switching the spools of the boom confluence control valve 20 and the boom control valve 21 during operation, while the valve opening is controlled by a control signal applied from the controller 22. It is configured to include a speed increase control valve (30, 40).

The control signal of the controller 22 includes an output of an electrical signal for performing a series of steps as shown in FIGS. 5 and 6, depending on a preset algorithm. In addition, the controller 22 is connected to the boom down

speed control valves

30 and 40 through a control line 27. For example, the control line 27 of the controller 22 is connected to a signal pressure port or a

solenoid portion

31 or 41 formed in the boomdown speed-up

control valves

30 and 40, and an electrical signal of the controller 22. The opening amount or the communication flow rate of the boom down speed increasing

control valves

30 and 40 is controlled depending on the output of.

According to one embodiment of the invention, the boom down speed control valve is composed of a solenoid valve 30, the solenoid valve 30 is configured to include a solenoid portion 31 and the inner flow path (33).

On the other hand, according to another embodiment of the present invention, as shown in Figure 4, the boom down speed control valve is composed of an electromagnetic proportional control valve 40, the electromagnetic proportional control valve 40 is a solenoid portion 41 ) And an internal passage 43 and a pilot signal pressure port 42.

The electromagnetic proportional control valve 40 proportionally controls the pilot signal pressure supplied from the pilot pump 1, and accordingly, when a control signal is applied from the controller 22, the boom confluence control valve 20. ) And a secondary pilot signal pressure for spool switching of the boom control valve 21.

In another embodiment of the invention, a predetermined signal detection sensor 44 is configured to be connected to the controller 22, the signal detection sensor 44 is the boom confluence control valve 20 and boom control valve 21 The hydraulic pressure of the boom cylinder 5 is quickly discharged to the hydraulic tank T by detecting the boom up signal and the boom down signal.

Preferably, the signal detection sensor 44 includes a pilot signal pressure sensor for spool switching, and a boom down signal for the boom confluence control valve 20 and the boom control valve 21, for example, an operation. When the lever 8 is pulled out, the pilot signal pressure output from the remote control valve 9 is sensed.

In the hydraulic device for a construction machine according to the present invention described above, a speed increase mode switch 23 for increasing the boom lowering speed is connected to the controller 22. For example, the speed increase mode switch 23 may be electrically connected to the controller 22 through a control line connected to one side of the cab or the operation lever 8.

Hereinafter, the operating principle of the hydraulic device for a construction machine according to the present invention.

As shown in Figs. 3 and 4, when the driver wants to raise the boom 2a by operating the operation lever 8, the pilot signal pressure from the remote control valve 9 is transmitted through the pilot line 20a. Is provided. The pilot signal pressure acts as a boom up signal to spool the boom confluence control valve 20 and the boom control valve 21 to the right in the drawing.

At this time, the pressure oil discharged from the second hydraulic pump P2 is supplied to the large chamber 5a of the boom cylinder 5 through the supply line 13, and at the same time, the pressure oil discharged from the first hydraulic pump P1 also merges. The line 24 is supplied to the large chamber 5a of the boom cylinder 5.

In addition, the pressurized oil returned from the small chamber 5b of the boom cylinder 5 is returned to the hydraulic tank T through the return line 14, thereby raising the boom.

When the boom confluence control valve 20 and the boom control valve 21 are neutral, the pressurized oil flows to the hydraulic tank T through the center bypass line 25.

According to the present invention, the operator can increase the speed of the boom down movement faster by operating the speed increase mode switch 23 in the construction site. For example, when the construction site needs to control the downward movement of the boom 2a to the bottom of the ground H or to the maximum excavation depth, the operator activates the speed increase mode switch 23 ON. In addition, the operation lever 8 of the boom 2a is driven.

More specifically, referring to FIGS. 3 and 5, in accordance with an embodiment of the present invention, the driver operates the operation lever 8 while the operator activates the speed increase mode switch 23 in an ON state. In order to increase the boom lowering speed, the controller 22 provides the solenoid valve 30 with a control signal for speed increase according to a preset algorithm.

In response to the control signal, the solenoid valve 30 acts as a signal pressure control valve for increasing the speed of the boom 2a. The solenoid valve 30 is switched to the right in the drawing so that the internal flow path 33 is a pilot flow path 21a for boom down. In communication with.

At this time, the pilot signal pressure spools the boom confluence control valve 20 and the boom control valve 21 through the pilot flow passage 21a to the left in the drawing. Accordingly, the pressure oil is simultaneously discharged from the large chamber 5a of the boom cylinder 5 which is under the combined hydraulic pressure to the hydraulic tank T through the respective return lines 26, thereby increasing the downward movement of the boom 2a. do.

As shown in FIG. 5, the above-described boom lowering movement can be controlled at twice the speed according to a preset algorithm in the controller 22, and the speed increase rate is varied to meet the specifications of the equipment and the needs of the operator. Can be modified.

On the other hand, according to another embodiment of the present invention, referring to Figures 4 and 6, the driver activates the speed increase mode switch 23 to the ON (on) state as well as operating the operation lever 8 to the boom In order to increase the falling speed, the controller 22 provides a control signal for increasing the speed to the proportional control valve 40 according to a preset algorithm.

In response to the control signal, the proportional control valve 40 acts as a proportional signal pressure control valve for increasing the speed of the boom 2a. The proportional control valve 40 is switched to the right in the drawing so that the internal flow path 43 is a pilot flow path for the boom down. It is in communication with 21a. For example, the internal flow path 43 of the proportional control valve 40 is switched to connect the pilot oil pressure discharged from the pilot pump 1 to the pilot flow path 21a.

The boom confluence control valve 20 and the boom control valve 21 are spooled to the left in the drawing by the pilot signal pressure via the internal flow path 43 and the pilot flow path 21a of the proportional control valve 40. Switch. Accordingly, the oil pressure is simultaneously discharged from the large chamber 5a of the boom cylinder 5, which is under the combined hydraulic pressure, to the hydraulic tank T through the respective return lines 26, thereby increasing the descending speed of the boom 2a. Will be.

On the other hand, when the signal detection sensor 44 detects the pilot signal pressure according to the boom down operation of the operation lever 8, the controller 22 determines whether the driver boom down operation. Subsequently, when the speed increase mode switch 23 is activated in the ON state, the downward movement of the boom is controlled to correspond to the secondary signal pressure output through the proportional control valve 40.

Ultimately, if the driver has to move the boom 2a to the bottom of the ground H at the construction site or lower the work tool to the maximum digging depth, the driver activates the above-mentioned speed increase mode switch 23 to lower the speed of the boom. Can be controlled to be more than twice as compared with the prior art.

Although the above embodiments have been described in detail with reference to the accompanying drawings and embodiments, the accompanying drawings and the above embodiments have been described by way of example to help those skilled in the art to understand the present invention. . Accordingly, the above embodiments are to be considered as illustrative and not restrictive, and the scope of the present invention should be construed in accordance with the invention set forth in the appended claims, the scope of which should be understood by those skilled in the art. Include various changes, alternatives, and equivalents by

The hydraulic device for a construction machine with a float function according to the present invention, when the operation of the boom in the construction site, the flow rate discharged from the hydraulic pumps are joined and supplied to the boom cylinder, under the ground (H) at the construction site Alternatively, when the boom must be lowered to the maximum digging depth, the flow rate of the boom cylinder is quickly discharged to the hydraulic tank according to the operation of the speed increase mode switch, which is very useful for increasing and controlling the boom lowering speed.

Claims

engine;

Work tools including booms, arms and buckets;

First and second hydraulic pumps connected to the engine and supplying hydraulic oil for driving the work device;

A remote control valve for outputting a pilot signal corresponding to the operation amount of the operation lever;

A boom confluence control valve installed between the first hydraulic pump and the hydraulic cylinder for the work device and controlling a confluence flow rate supplied to the boom cylinder when the spool is switched;

A boom control valve installed between the second hydraulic pump and the boom cylinder to control movement of the boom;

A controller electrically connected to the operation lever and outputting a preset control signal during a boom down operation; And

A boom down speed control valve for outputting a pilot signal pressure for switching the boom confluence control valve and the spool of the boom control valve during the boom down operation of the operation lever, the valve opening being controlled by a control signal applied from the controller. Hydraulic device for a construction machine, characterized in that comprising a.
The method of claim 1,

The boom down speed control valve is a hydraulic device for a construction machine, characterized in that consisting of a solenoid valve.
The method of claim 1,

The boom-down speed control valve is composed of an electronic proportional control valve, the hydraulic proportional control device for a construction machine, characterized in that the proportional control of the pilot signal pressure supplied from the pilot pump.
The method of claim 1,

Hydraulic device for a construction machine, characterized in that the regeneration flow path is further configured between the boom confluence control valve and the boom control valve.
The method according to claim 2 or 3,

And a signal detection sensor is connected to the controller, wherein the signal detection sensor detects a boom up signal and a boom down signal for the boom confluence control valve and the boom control valve.
The method of claim 5,

The signal detection sensor is a hydraulic device for a construction machine comprising a pilot signal pressure sensor for spool switching.
The method of claim 5,

Hydraulic apparatus for a construction machine, characterized in that the increase mode switch for increasing the boom lowering speed is configured to be connected to the controller.