KR20160017318A - A Hydraulic Control Device for Construction Equipment - Google Patents

Abstract

The present invention relates to a hydraulic control system of construction equipment, which comprises: a pressed oil storage tank; a cooling unit for cooling the construction equipment; a steering unit for controlling the movement direction of the construction equipment; a working unit for performing work through the construction equipment; a brake unit for controlling the movement of the construction equipment; a pump for supplying pressed oil stored in the pressed oil storage tank to the brake unit and the cooling unit; priority control equipment for controlling the pressed oil supplied from the pump to the brake unit or the cooling unit; and a steering/working unit controlling equipment for controlling the supply of pressed oil flowing in the steering unit or the working unit to the brake unit. The hydraulic control system of construction equipment according to the present invention has effects of: rapidly coping with a sudden flow interruption and an instantaneous flow change by connecting a pressed oil control system installed in the steering and working equipment with a brake and cooling system; and reducing the fatigue of a driver and increasing the motor durability of a fan by preventing noise caused by a speed change of the fan installed in the cooling system. The hydraulic control system of construction equipment according to the present invention is able to reduce the refilling number of the pressed oil in the brake system by flexibly supplying pressed oil flowing in the steering and working equipment.

Description

[0001] Hydraulic Control Device for Construction Equipment [0002]

The present invention relates to a hydraulic control system for a construction machine.

Construction equipment generally refers to construction civil engineering machinery, and each construction such as roads, rivers, ports, railways, and plants has a structure and performance suited to its characteristics. In other words, the construction equipment can be divided into excavation equipment, loading equipment, conveying equipment, loading equipment, compaction equipment, foundation equipment and the like due to the variety of work done in the industrial field. Specifically, the construction equipment can be classified into bulldozer, excavator, , Rollers, and the like.

The most basic work performed in the industrial field is digging. In the case of industrial construction, excavation works are mostly carried out by excavating the ground to a certain depth and installing various structures or laying pipes on the ground.

An excavator is a construction machine that carries out works such as excavation work for digging the ground in civil engineering, construction, construction site, loading work for transporting soil, crushing work for dismantling the building, suspension work for arranging the ground, And an upper revolving body mounted on the traveling body and rotated by 360 degrees and a working device.

Crawler crawlers are classified into crawler crawlers and tire-type wheel excavators according to the driving style of the vehicle. Crawler excavator is more widely used in each work site from 1 ton to more than 100 tons of equipment because it is stable and work productivity compared to wheel excavator. Wheel excavator is compared with crawler excavator It is used mainly in the work site where the work stability can be reduced but the road can be traveled and the work place can be moved without a trailer and frequently work and movement are required.

In addition, excavators can be used with appropriate working equipment depending on the state of the earth and rock, the type of work and the application. Buckets for general excavation and excavation, breakers for crushing hard ground, rocks, and crushers used for dismantling and crushing buildings.

In addition to the excavator, there is a front unit including a boom and a bucket in front of the main body of the construction machine. There is a wheel loader used for carrying aggregate materials such as crushed rocks, soil and the like, and for transportation at a short distance and a forklift used for lifting or transporting heavy cargo .

The conventional wheel loader was provided with a brake system and a pump for supplying pressurized oil to the cooling system, respectively. Therefore, unnecessary pressurized fluid flows to the brake system and the cooling system, resulting in pipe loss and power loss.

As a result, a control system has been developed to control the pressurized oil with a single pump to the brake system and the cooling system so that the pressurized oil can be appropriately supplied to the system requiring pressurized oil. However, even if the control system suddenly stops the supply of the flow instantaneously due to the sudden change in the flow rate of the pressurized oil, that is, the cavitation, there is a problem that serious damage occurs to the system.

Therefore, a lot of research and development are going on in order to solve the problem.

It is an object of the present invention to provide a brake system and a cooling system of a steering apparatus and a working apparatus which are connected to a pressure control system of a steering apparatus and a working apparatus so that sudden change in flow rate and interruption of flow rate And to provide a hydraulic control system of a construction machine for enabling quick response.

A hydraulic control system for a construction machine according to an aspect of the present invention includes: a pressure oil storage tank; A cooling unit for cooling a construction machine; A steering unit for controlling a moving direction of the construction machine; A work unit for performing an operation through the construction machine; A brake unit for controlling the movement of the construction machine; A pump for supplying pressure oil stored in the pressure oil storage tank to the brake unit and the cooling unit; A priority control device for controlling the pressure oil supplied from the pump to the brake unit or the cooling unit; And a steering and working unit control device for controlling supply of the pressure oil flowing into the steering unit or the working unit to the brake unit.

Specifically, the priority control device can selectively control supply from the pump to the brake unit or the cooling unit.

Specifically, the system may further include an accumulator provided between the priority control device and the brake unit, for pre-charging the pressure oil supplied from the pump to the brake unit.

Specifically, the priority control device can supply the pressure oil of the pump to the cooling unit when the pressure of the accumulator is equal to or higher than a predetermined value.

Specifically, when the pressure of the accumulator is less than a preset value, the steering and working unit control device may supply the accumulator with the pressure oil flowing into the steering unit or the working unit.

Specifically, a first sensor measures the pressure of the pressure oil flowing in the front end of the priority control device; And a second sensor for measuring the pressure of the accumulator.

Specifically, when the pressure value of the pressure oil measured by the first sensor is equal to or greater than a predetermined value, the pump increases the pressure oil discharge amount more than the average pressure oil discharge amount, and when the pressure value of the pressure oil measured by the first sensor is less than a predetermined value , It is possible to reduce the amount of the pressure oil discharged from the average pressure oil discharge amount.

More specifically, a control unit for controlling the pump, the priority control unit, the steering and the operation unit control unit through a pressure value measured by the first sensor, the second sensor, the third sensor, or the fourth sensor Wherein the control unit supplies pressure oil to the accumulator through the steering and working unit control device when the pressure value measured by the second sensor is lower than a preset accumulator pressure value, The pressure oil can be supplied to the brake unit through the steering and working unit control device when the value is lower than the preset brake unit pressure value.

The hydraulic control system of the construction machine according to the present invention has an effect that the hydraulic pressure control system provided in the steering and working apparatuses is connected to the brake and cooling system so that abrupt flow rate interruption and instantaneous change in flow rate can be quickly responded. It is possible to prevent the noise due to the change in the speed of the fan provided in the cooling system, thereby reducing the fatigue of the driver and increasing the motor durability of the fan.

Further, in the hydraulic control system of the construction machine according to the present invention, the supply of the pressure oil flowing in the steering and the working device is made flexible, thereby reducing the number of times the brake system is filled in the brake system.

1 is a side view of a construction machine having a hydraulic control system of the present invention.
2 is a conceptual diagram of a conventional construction machine hydraulic control system.
3 is a conceptual diagram of a construction machine hydraulic control system of the present invention.

BRIEF DESCRIPTION OF THE DRAWINGS The objects, particular advantages and novel features of the present invention will become more apparent from the following detailed description taken in conjunction with the accompanying drawings, in which: FIG. It should be noted that, in the present specification, the reference numerals are added to the constituent elements of the drawings, and the same constituent elements have the same numerical numbers as much as possible even if they are displayed on different drawings. In the following description, well-known functions or constructions are not described in detail since they would obscure the invention in unnecessary detail.

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

1 is a side view of a construction machine including a hydraulic control system. Hereinafter, a construction machine 1 including a construction machine hydraulic control system 21 according to an embodiment of the present invention will be described with reference to FIG. Here, the construction machine 1 shown in Fig. 1 may be a wheel loader 1 and is merely an example for illustrating the hydraulic control system of the present invention, but is not limited thereto.

As shown in Fig. 1, the wheel loader 1 is a construction machine that carries out operations such as a loading operation for loading aggregates such as crushed rock mass, soil and the like, or a transportation operation for transporting such materials at a short distance, A wheel loader main body 30, and a traveling device 40. [

The working device 10 is provided at one side of the wheel loader 1 and comprises a bucket 12 and a boom 15. The boom 15 is operated by a boom cylinder 14, The bucket cylinder 11 and the loader linkage 13 can perform detailed operations.

For example, when the bucket cylinder 11 is compressed, the loader linkage 13 is rotated in the direction of the bucket 12, so that the end of the bucket 12 is moved forward. When the bucket cylinder 11 is tensioned, (13) is rotated in a direction opposite to the bucket (12), i.e., inside the bucket (12), so that the gravel or the like can be contained in the internal space.

Specifically, when the boom cylinder 14 is compressed, the boom 15 is rotated downward to move the bucket 12 toward the ground. As the end of the bucket 12 comes into contact with the ground due to the compression of the bucket cylinder 11, Ready state.

Thereafter, the bucket cylinder 11 is pulled to load aggregate such as crushed rock mass, soil and the like into the bucket 11, and the traveling device 40 to be described later is driven to move to an unloading place of the aggregate do. At this time, the bucket 11 can be moved to the unloading position while being positioned close to the ground. In a state where the bucket 11 is lifted from the ground by pulling the boom cylinder 14 and raising the boom 15 You can also move to an unloading location.

The wheel loader main body 30 includes a driving unit 31, a counterweight 32, and an engine 33, which are connected to the front portion of the work unit 10 and mounted on the driving unit 40 so as to be movable. .

The operating room 31 is provided with various operating devices that can operate the wheel loader 1 by a worker (not shown) such as a work device operating portion (not shown) and a traveling operating portion (not shown). A plurality of levers or switches for respectively operating the detailed configuration of the working device 10 can be provided on the working device operating portion. The traveling operating portion includes an accelerator pedal, a brake pedal, A plurality of traveling levers for adjusting the front, rear, left, and right directions can be provided.

A front wheel 42 is rotatably mounted on the front side of the main body 30 and a rear wheel 41 is rotatably mounted on the rear side thereof. It can be installed and configured as much as possible.

Hereinafter, prior to describing the construction machine hydraulic control system 21 of the present invention for driving the construction machine 1 as described above, the conventional construction machine hydraulic control system 20 will be described with reference to FIG. In addition, the construction machine hydraulic control systems 20 and 21 below may be provided in the crawler excavator shown in FIG. 1, but the present invention is not limited thereto and may be provided in other excavators.

2 is a conceptual diagram of a conventional construction machine hydraulic control system.

The pressure oil stored in the pressurized oil storage tank 210 is supplied to the brake unit 230 and the accumulator (not shown) by the pump 220, 240, and a cooling unit 260, respectively.

The supply amount of the pressurized oil stored in the pressurized oil storage tank 210 can be adjusted in accordance with the pressure value measured by the first sensor 291 provided at the front end of the control device 270 first. Specifically, when the pressure value measured by the first sensor 291 increases, the angle of the swash plate angle (not shown) of the variable displacement pump 221 is reduced under the control of the pump flow control valve 222, (220).

On the other hand, when the pressure value measured by the first sensor 291 decreases, the angle of the swash plate angle of the variable displacement pump 221 is increased under the control of the pump flow control valve 222, The flow rate of the pressure oil can be increased.

The conventional hydraulic control system 20 connects the pressurized oil storage tank 210 with the brake unit 230 and the cooling unit 260 in parallel to supply the pressurized oil from the pressurized oil storage tank 210 to the brake unit 230 and the cooling unit 260 at the same time.

but. The pressure oil discharged from the pressure oil storage tank 210 is preferentially supplied to the brake unit 230 by the priority control valve 271 of the control device 270. [

At this time, the pressurized oil can be stored in the accumulator 240 provided between the service brake 231 of the brake unit 230 and the priority control valve 271 before the pressurized oil is supplied to the brake unit 230, When the pressure measurement value of the accumulator 240 measured by the second sensor 292 becomes equal to or larger than a predetermined value or when the pressure measurement value of the pressure supplied to the parking brake 232 measured by the third sensor 293 is When the pressure exceeds the predetermined value, the pressure oil is first supplied to the cooling system 260 by the control valve 271.

The cooling unit 260 includes a fan 261 to achieve cooling of various devices (not shown) through the drive of the fan 261. The fan 261 is driven by a hydraulic motor (Not shown).

The hydraulic pressure control system 20 of the conventional construction machine is configured such that when the pressure measurement value of the accumulator 240 becomes equal to or higher than a predetermined value or when the pressure measurement value of the pressure supplied to the parking brake 232 exceeds a predetermined value The amount of pressure oil supplied to the cooling system 260 is reduced when the serviced brake 231 or the parking brake 232 is driven, There is a problem that the speed of the fan 261 is reduced and thus noise and vibration are generated.

When the brakes 231 and 232 are driven frequently, a change in the flow rate supplied to the cooling system 260 occurs very frequently, so that a heavy load is applied to the cooling system 260, And vibrations are also generated very violently, resulting in an increase in fatigue of the operator. If the flow rate is suddenly reduced, cavitation occurs and the durability is extremely weakened.

Therefore, in order to solve such a problem, the hydraulic control system 21 of the construction machine of the present invention has been developed. Hereinafter, the hydraulic control system 21 of the construction machine of the present invention will be described in detail with reference to FIG. 3 .

3 is a conceptual diagram of a construction machine hydraulic control system of the present invention.

3, the construction machine hydraulic control system 21 of the present invention includes a pressure oil storage tank 210, a variable displacement pump 220, a brake unit 230, an accumulator 240, a cooling unit A control unit 250, a cooling unit 260, a priority control unit 270, a steering and operation unit control unit 280, and a control unit 290. The hydraulic control system 21 of the construction machine according to the present invention can be applied to the hydraulic control system 20 of the conventional construction machine described in Fig. 2 in addition to the steering and working unit control device 280 and the control unit 290, The same reference numerals are used for the sake of convenience, but they are not necessarily construed to be the same.

The construction machine hydraulic control system 21 according to the embodiment of the present invention includes a work unit 2811 for performing work through the construction machine 1 and a steering unit 2812 for controlling the movement direction of the construction machine 1 .

The working unit 2811 may include a main control valve (not shown) for controlling the working oil supplied to the working unit 10 and the working unit 10, and a steering unit (not shown) And a steering control valve (not shown) for controlling the pressure oil supplied to the steering device.

The working unit 2811 controls the pressure oil through the main control valve to drive the working device 10 and the steering unit 2812 can control the pressure oil through the steering control valve to drive the steering device.

The pressurized oil storage tank 210 stores the pressurized oil for operating the brake unit 230 and the cooling unit 260. The pressurized oil storage tank 210 can supply the stored pressurized oil to the brake unit 230 and the cooling unit 260 and can supply and store the pressurized oil after being used in the brake unit 230 and the cooling unit 260 .

The pump 220 supplies the pressurized oil stored in the pressurized oil storage tank 210 to the brake unit 230 and the cooling unit 260. The pump 220 supplies pressurized oil to not only the brake unit 230 and the cooling unit 260 but also the accumulator 240 to be described later so that the accumulator 240 can store the pressurized oil.

The pump 220 may include a variable displacement pump 221 and a pump flow control valve 222. The variable displacement pump 221 can control the flow rate of the pressure oil discharged from the pressure oil storage tank 210 by the swash plate angle (not shown) and can be driven by receiving power from the engine 33.

Specifically, in the pump 220, the pump flow control valve 222 is operated through the pressure or flow rate value of the pressure oil supplied to the control device 270, and the pump flow control valve 222 adjusts the swash plate angle And adjusts the amount of the pressurized oil discharged from the variable displacement pump 221. The pump 220 can control the flow rate of the pressure oil discharged from the pressurized oil storage tank 210.

The brake unit 230 controls the movement of the construction machine 1. The brake unit 230 can be constituted by the service brake 231 and the parking brake 232. Since the operation of the brakes 231 and 232 is very important for the safety of the operator in the operation of the construction machine 1, (230) can be preferentially supplied with the pressurized oil.

The accumulator 240 may first be installed between the controller 270 and the brake unit 230 and may pre-charge the pressure oil supplied from the pump 220 to the brake unit 230.

The accumulator 240 stores the pressure oil to be supplied to the brake unit 230, so that the pressure oil can be supplied in a timely manner when the brake unit 230 is operated. Therefore, the accumulator 240 should always be kept at a predetermined level of pressure so that the pressure oil in the accumulator 240 should be stored at a predetermined value or higher.

At this time, the pressure value of the pre-set accumulator may be 100 to 150 bar, and preferably 125 bar.

The cooling unit control device 250 can control the flow rate of the pressure oil supplied to the cooling unit 260. [ The cooling unit control device 250 may include a cooling unit control valve 251 and may control the flow rate of the pressure oil supplied to the cooling unit 260 according to the switching of the cooling unit control valve 251.

The cooling unit 260 can cool the devices (not shown) driven by the construction machine 1 and improve the durability of the devices driven by the construction machine 1 through the cooling of the cooling unit 260 .

The cooling unit 260 may include a fan 261, and air can be flowed by driving the fan 261, so that the air-cooling type heat exchange can be performed. At this time, the strength of the air flow can be adjusted by the pressure oil supplied from the pressure oil storage tank 210 by the fan 261.

For example, when the supply of the pressurized oil to the cooling unit 260 increases due to the cooling unit control valve 251, the load of the hydraulic motor (not shown) increases and the driving speed of the fan 261 driven through the hydraulic motor When the supply of the pressurized oil to the cooling unit 260 is reduced, the load of the hydraulic motor is reduced and the driving speed of the fan 261 driven by the hydraulic motor is decreased.

First, the control device 270 controls the pressure oil supplied from the pump 220 to the brake unit 230 or the cooling unit 260. The control device 270 can selectively control the supply from the pump 220 to the brake unit 230 or the cooling unit 260. [

Specifically, first, the control device 270 may include the control valve 271 first.

The control valve 271 can supply the pressurized oil to the cooling unit 260 when the pressure of the hydraulic oil supplied to the brake unit 230 is equal to or higher than the preset priority control pressure, If the oil pressure is equal to or higher than the preset priority control pressure, the cooling unit 260 can be supplied with the pressurized oil.

First, the control valve 271 cuts off the pressure oil supplied to the cooling unit 260 when the pressure of the pressure oil supplied to the brake unit 230 is lower than the predetermined brake unit pressure value, The entire flow rate can be supplied to the brake unit 230. In addition, even when the pressure of the pressure oil stored in the accumulator 240 is lower than the pre-set accumulator pressure value, the pressure oil supplied to the cooling unit 260 is blocked and the total flow quantity of the pressure oil discharged from the pressure oil storage tank 210 is supplied to the brake unit 230, respectively.

Here, the preset brake unit pressure value preset accumulator pressure value may be 100 to 150 bar, and preferably 125 bar.

The steering and working unit control device 280 controls the supply of the pressure oil flowing into the steering unit 2812 or the working unit 2811 to the brake unit 230.

Since the pressure of the brake fluid is always maintained at a value equal to or higher than the predetermined brake unit pressure, there is a problem that the supply of pressure oil to the cooling unit 260 is unstable. Specifically, if the consumption of the pressure oil suddenly increases in the brake unit 230, the pressure oil stored in the accumulator 240 is instantaneously decreased. As a result, the control unit 270 stops the pressure oil supplied to the cooling unit 260 , And supplies the pressurized oil to the brake unit 230, that is, the accumulator 240.

Therefore, the flow rate of the pressure oil supplied to the cooling unit 260 suddenly decreases to stop the driving of the fan 261, so that the cooling operation of the driving device of the construction machine 1 is not performed, If the flow rate of the pressure oil flowing into the fan 261 suddenly decreases, cavitation may occur and the durability of the fan 261 may be seriously reduced.

Accordingly, the pressure oil control system 21 of the construction machine according to the embodiment of the present invention further includes a steering and operation unit control device 280 to control the operation of the steering and work unit (not shown) even if the amount of pressure oil consumption suddenly increases in the brake unit 230 2811 and 2812 to the brake unit 230, the flow rate of the pressure oil supplied to the cooling unit 260 can be kept constant.

Therefore, the operation of the cooling unit 260 can be smoothly performed, noise and vibration of the fan 261 are reduced, and durability of the fan 261 is also increased.

The steering and working unit control device 280 controls the operation of the working unit 2811 and the steering unit 2812 when the pressure or flow rate of the pressure oil supplied to the brake unit 230 is less than the predetermined brake unit pressure or flow value The pressure oil flowing into the working unit 2811 and the steering unit 2812 can be supplied to the accumulator 240 when the pressure of the accumulator 240 is lower than the preset accumulator pressure value have.

The hydraulic control system 21 of the construction machine according to the embodiment of the present invention includes a first sensor 291 for measuring the pressure of the hydraulic fluid flowing in the front end of the control device 270 and a second sensor 291 for measuring the pressure of the accumulator 240 A third sensor 293 for measuring the pressure of the hydraulic oil supplied to the brake unit 230 and a fourth sensor 294 for measuring the pressure of the hydraulic oil supplied to the cooling unit 260 .

Each of the sensors 291, 292, 293, and 294 can transmit the measured pressure value to the control unit 290, which will be described later, by wire or wirelessly.

The control unit 290 can receive the pressure values measured by the respective sensors 291, 292, 293 and 294 by wire or wireless and control the pump 220, the priority control device 270, the steering and the operation unit control device 280 .

Specifically, when the pressure value measured by the first sensor 291 is equal to or greater than the predetermined priority control pressure value, the control unit 290 operates the pump flow control valve 222 to control the flow rate of the pressure oil discharged from the pressurized oil storage tank 210 When the pressure value measured by the first sensor 291 is less than the predetermined priority control pressure value, the pump flow control valve 222 is operated to increase the flow rate of the pressure oil discharged from the pressure oil storage tank 210 have.

The control unit 290 may supply the pressurized oil to the accumulator 240 through the steering and working unit control device 280 when the pressure value measured by the second sensor 292 is less than the preset accumulator pressure value, 3 sensor 293 is lower than the predetermined brake unit pressure value, the pressure oil can be supplied to the brake unit 230 through the steering and working unit control device 280. [

The controller 290 decreases the flow rate of the pressure oil supplied from the pressure oil storage tank 210 through the cooling unit controller 250 when the pressure value measured by the fourth sensor 294 is equal to or higher than the preset pressure value of the cooling unit And if the pressure value measured by the fourth sensor 294 is lower than the predetermined cooling unit pressure value, the flow rate of the pressure oil supplied from the pressure oil storage tank 210 through the cooling unit control unit 250 can be increased.

Thus, the hydraulic control system 21 of the construction machine according to the present invention controls the hydraulic and hydraulic control system (not shown) of the brake and cooling hydraulic control systems (not shown) provided in the steering and working units 2811 and 2812, (Not shown) to prevent noise due to a change in the speed of the fan 261 provided in the cooling unit 260, It is possible to reduce the fatigue of the fan 261 and to increase the motor durability of the fan 261.

In addition, the hydraulic control system 21 of the construction machine according to the present invention has an effect that the supply of pressure oil flowing to the steering and working units 2811, 2812 is made flexible so that the number of times of pushing the brake unit 230 is reduced have.

While the present invention has been particularly shown and described with reference to exemplary embodiments thereof, it is to be understood that the same is by way of illustration and example only and is not to be construed as limiting the present invention. It is obvious that the modification and the modification are possible.

It will be understood by those skilled in the art that various changes in form and details may be made therein without departing from the spirit and scope of the invention as defined by the appended claims.

1: Construction machine 10: Work machine
11: Bucket cylinder 12: Bucket
13: Loader linkage 14: Boom cylinder
15: boom 20: conventional hydraulic control system
21: Hydraulic control system 210 of the present invention: Pressurized oil storage tank
220: pump 221: variable displacement pump
222: Pump flow control valve 230: Brake unit
231: Service de brakes 232: Parking brakes
240: Accumulator 250: Cooling unit control device
251: Cooling unit control valve 260: Cooling unit
261: Fan 270: Priority control device
271: First control valve 280: Steering and working unit control device
281: Steering and working unit control valve 2811: Working unit
2812: Steering unit 290:
291: first sensor 292: second sensor
293: third sensor 294: fourth sensor
30: Wheel loader main body 31: Cab
32: Counterweight 33: Engine
40: traveling device 41: rear wheel
42: front wheel

Claims (8)

Pressure oil storage tank;
A cooling unit for cooling a construction machine;
A steering unit for controlling a moving direction of the construction machine;
A work unit for performing an operation through the construction machine;
A brake unit for controlling the movement of the construction machine;
A pump for supplying pressure oil stored in the pressure oil storage tank to the brake unit and the cooling unit;
A priority control device for controlling the pressure oil supplied from the pump to the brake unit or the cooling unit; And
And a steering and working unit control device for controlling supply of the hydraulic fluid flowing to the steering unit or the working unit to the brake unit. 2. The apparatus according to claim 1,
Wherein the control unit selectively controls supply to the brake unit or the cooling unit from the pump. The method according to claim 1,
Further comprising an accumulator disposed between the priority control device and the brake unit for precharging the hydraulic fluid supplied from the pump to the brake unit. 4. The apparatus according to claim 3,
And supplies the pressure oil of the pump to the cooling unit when the pressure of the accumulator is equal to or greater than a predetermined value. 4. The steering and working unit control device according to claim 3,
Wherein the control unit supplies the accumulator with the pressure oil flowing into the steering unit or the operation unit when the pressure of the accumulator is less than a predetermined value. The method of claim 3,
A first sensor for measuring the pressure of the pressure oil flowing in the front end of the priority control device; And
A second sensor for measuring the pressure of the accumulator;
A third pre sentence for measuring pressure of the pressure oil supplied to the brake unit; And
And a fourth sensor for measuring a pressure of the hydraulic oil supplied to the cooling unit. 7. The pump according to claim 6,
When the pressure value of the pressure oil measured by the first sensor is equal to or greater than a predetermined value, the pressure oil discharge amount is increased beyond the mean pressure oil discharge amount,
Wherein when the pressure value of the pressure oil measured by the first sensor is equal to or less than a predetermined value, the pressure oil discharge amount is reduced more than the average pressure oil discharge amount. The method according to claim 6,
Further comprising a control unit for controlling the pump, the priority control unit, the steering and the operation unit control unit through a pressure value measured by the first sensor, the second sensor, the third sensor or the fourth sensor,
Wherein,
When the pressure value measured by the second sensor is lower than a pre-set accumulator pressure value, the pressure oil is supplied to the accumulator through the steering and working unit control device,
And when the pressure value measured by the third sensor is lower than the predetermined brake unit pressure value, supplies the pressure oil to the brake unit through the steering and working unit control device.

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