KR20110072587A - Hydraulic system of construction equipment - Google Patents

Hydraulic system of construction equipment Download PDF

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Publication number
KR20110072587A
KR20110072587A KR1020090129576A KR20090129576A KR20110072587A KR 20110072587 A KR20110072587 A KR 20110072587A KR 1020090129576 A KR1020090129576 A KR 1020090129576A KR 20090129576 A KR20090129576 A KR 20090129576A KR 20110072587 A KR20110072587 A KR 20110072587A
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KR
South Korea
Prior art keywords
control valve
boom
hydraulic pump
hydraulic
cylinder
Prior art date
Application number
KR1020090129576A
Other languages
Korean (ko)
Inventor
이양구
Original Assignee
볼보 컨스트럭션 이큅먼트 에이비
Priority date (The priority date is an assumption and is not a legal conclusion. Google has not performed a legal analysis and makes no representation as to the accuracy of the date listed.)
Filing date
Publication date
Application filed by 볼보 컨스트럭션 이큅먼트 에이비 filed Critical 볼보 컨스트럭션 이큅먼트 에이비
Priority to KR1020090129576A priority Critical patent/KR20110072587A/en
Publication of KR20110072587A publication Critical patent/KR20110072587A/en

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Classifications

    • E—FIXED CONSTRUCTIONS
    • E02—HYDRAULIC ENGINEERING; FOUNDATIONS; SOIL SHIFTING
    • E02F—DREDGING; SOIL-SHIFTING
    • E02F9/00—Component parts of dredgers or soil-shifting machines, not restricted to one of the kinds covered by groups E02F3/00 - E02F7/00
    • E02F9/14—Booms only for booms with cable suspension arrangements; Cable suspensions
    • E—FIXED CONSTRUCTIONS
    • E02—HYDRAULIC ENGINEERING; FOUNDATIONS; SOIL SHIFTING
    • E02F—DREDGING; SOIL-SHIFTING
    • E02F9/00—Component parts of dredgers or soil-shifting machines, not restricted to one of the kinds covered by groups E02F3/00 - E02F7/00
    • E02F9/20—Drives; Control devices
    • E02F9/22—Hydraulic or pneumatic drives
    • F—MECHANICAL ENGINEERING; LIGHTING; HEATING; WEAPONS; BLASTING
    • F15—FLUID-PRESSURE ACTUATORS; HYDRAULICS OR PNEUMATICS IN GENERAL
    • F15B—SYSTEMS ACTING BY MEANS OF FLUIDS IN GENERAL; FLUID-PRESSURE ACTUATORS, e.g. SERVOMOTORS; DETAILS OF FLUID-PRESSURE SYSTEMS, NOT OTHERWISE PROVIDED FOR
    • F15B11/00—Servomotor systems without provision for follow-up action; Circuits therefor
    • F15B11/16—Servomotor systems without provision for follow-up action; Circuits therefor with two or more servomotors
    • F15B11/17—Servomotor systems without provision for follow-up action; Circuits therefor with two or more servomotors using two or more pumps
    • F—MECHANICAL ENGINEERING; LIGHTING; HEATING; WEAPONS; BLASTING
    • F15—FLUID-PRESSURE ACTUATORS; HYDRAULICS OR PNEUMATICS IN GENERAL
    • F15B—SYSTEMS ACTING BY MEANS OF FLUIDS IN GENERAL; FLUID-PRESSURE ACTUATORS, e.g. SERVOMOTORS; DETAILS OF FLUID-PRESSURE SYSTEMS, NOT OTHERWISE PROVIDED FOR
    • F15B13/00—Details of servomotor systems ; Valves for servomotor systems
    • F15B13/02—Fluid distribution or supply devices characterised by their adaptation to the control of servomotors
    • F15B13/06—Fluid distribution or supply devices characterised by their adaptation to the control of servomotors for use with two or more servomotors

Abstract

PURPOSE: A hydraulic circuit for construction machinery is provided to improve workability by increasing a boom driving rate by improving the working fluid supply quantity the boom rising side. CONSTITUTION: A hydraulic circuit for construction machinery comprises a capacity variable first hydraulic pump(50), a capacity variable second hydraulic pump(51), the first traveling control valve, a first control valve, a second traveling control valve(62), second control valves(66,67,76) and a boom primary control valve(102). The first traveling control valve is installed on the passage of a center bypass of the first fluid pressure pump. The first traveling control valve controls the start, stop and direction conversion of a travel motor. The first control valve is installed on the center bypass which is on downstream side of the first traveling control valve. The first control valve is respectively connected through a parallel line. The second control valve for the work equipment is installed on the center bypass which is on downstream side of the first traveling control valve. The boom primary control valve controls the working fluid amount.

Description

Hydraulic system of construction equipment

The present invention is a hydraulic system using two hydraulic pumps that are universally applied to construction equipment such as excavators, the hydraulic pressure for construction equipment to increase the boom driving speed in the complex operation of driving the boom and the swinging device at the same time It is about the system.

More specifically, when performing a compound operation by operating the boom and the turning device operating lever at the same time according to the working conditions of the excavator, it is controlled to reduce the operating flow rate supplied to the turning device by the boom raising operation signal, Therefore, the present invention relates to a hydraulic system for construction equipment that increases the supply of hydraulic oil toward the boom up to increase the boom driving speed.

Hydraulic system for construction equipment according to the prior art shown in Figure 1 (refers to a hydraulic system using two hydraulic pumps),

Variable displacement first and second hydraulic pumps 50 and 51 (hereinafter referred to as first and second hydraulic pumps) connected to an engine (not shown);

A first control valve 54 for driving provided in the center bypass passage 52 of the first hydraulic pump 50 for controlling the starting, stopping, and direction change of the left traveling motor 53;

It is installed in the center bypass passage 52 to the downstream side of the first control valve 54 for travel and connected via the parallel line 55, respectively, the boom cylinder 64, the swing motor 56 and the arm cylinder 57 First control valves 68, 58, and 59 for controlling the hydraulic oil supplied to

A second control valve 62 for traveling installed in the center bypass passage 60 of the second hydraulic pump 51 for controlling the starting, stopping, and direction change of the right traveling motor 61;

It is installed in the center bypass passage 60 to the downstream side of the traveling second control valve 62 and connected via the parallel line 63, respectively, the boom cylinder 64, the bucket cylinder 65 and the arm cylinder 57 And second control valves (66, 67, 76) for the working device to control the hydraulic fluid supplied to the respective.

In the conventional hydraulic system configured as described above, as the first control valve 54 for the traveling motor is switched by the driving lever operation not shown to drive the excavator, the hydraulic pump is supplied from the first hydraulic pump 50. The left driving motor 53 is driven by the working oil, and the right driving motor 61 is driven by the hydraulic oil supplied from the second hydraulic pump 51 when the second control valve 62 for the driving motor is switched. Therefore, the construction equipment can run smoothly.

Meanwhile, as the first control valve 58 for the swing motor is switched to swing the construction equipment, the swing motor 56 may be driven by the hydraulic oil supplied from the first hydraulic pump 50. This allows the upper frame to pivot about the undercarriage of the excavator.

As the first control valve 68 for the boom is switched to the right in the drawing by the lever operation for the work device to drive the boom, the hydraulic oil discharged from the first hydraulic pump 50 is the first control valve 68. And the large chamber 64a of the boom cylinder 64 through the confluence passage 77.

In addition, as the second control valve 66 for the boom is switched to the left in the drawing, the hydraulic oil discharged from the second hydraulic pump 51 is joined to the confluence passage 77 through the second control valve 66. The boom cylinder 64 is supplied to the large chamber 64a. At this time, the hydraulic oil from the small chamber 64b of the boom cylinder 64 is returned to the hydraulic tank via the first and second control valves 68 and 66.

Therefore, it is possible to raise the boom.

On the other hand, when the boom and the swinging device are simultaneously driven according to the working conditions to carry out the combined work, the boom and the swinging first control valves 68 and 58 are switched, respectively, and are discharged from the first hydraulic pump 50. A part of the working oil is supplied to the large chamber 64a of the boom cylinder 64 via the first control valve 68 for the boom. At the same time, a part of the hydraulic oil discharged from the first hydraulic pump 50 is supplied to the swing motor 56 via the parallel line 55 and the first control valve 58 for the swing motor.

At this time, when the hydraulic oil pressure generated in the boom cylinder 64 becomes larger than the hydraulic oil pressure generated in the swinging motor 56, the hydraulic oil supplied from the first hydraulic pump 50 to the boom cylinder 64 is pivoted. The amount of hydraulic oil supplied to the motor 56 becomes relatively large. This slows down the boom speed and decreases workability.

On the other hand, in the case of the excavator, the circuit is configured so that the flow rate increases toward the boom more than the normal turning in the combined operation of the boom and the turning.

As a conventional hydraulic system (see FIG. 1) designed to give priority to a boom as described above, in a pair of hydraulic pump systems, two boom spools and one swing spool are used. Is designed to use two hydraulic pumps and two spools simultaneously and one hydraulic pump and one spool for turning.

In this case, when the boom and turning are operated simultaneously, one hydraulic pump of the two hydraulic pumps is used as the boom only, and the remaining one hydraulic pump is supplied to the boom and the turner so that the flow rate of the boom is higher than the turning so that the boom has priority. .

Conceptually, assuming that the maximum discharge flow rate of one hydraulic pump is 100, the flow rate for the boom alone is the maximum flow rate of the two hydraulic pubs, that is, 200, and the maximum flow rate of one hydraulic pump for the swing alone. 100 will be used. In this case, when the boom and the swing move simultaneously, the boom uses 150 using the maximum flow rate of one hydraulic pump and the other half of the hydraulic pump, and the swing uses 50 using the half of one hydraulic pump. It has a flow distribution of 50 to give priority to the boom.

Such a conventional hydraulic system may have a 3: 1 flow distribution when the boom and the turning load pressure are the same, but if the load pressure of the boom is higher than the turning load pressure, the boom in the flow rate branched from one hydraulic pump This reduces the possible flow rate, making it impossible to distribute the flow rate of 3: 1.

In addition, in the case of an excavator, the load of the boom and the turning pressure is changed according to the position of the work equipment, and if the load pressure of the boom and the turning load is variable, this flow distribution is also variable, so that the stable boom priority is impossible.

Embodiment of the present invention, in the construction equipment to which the hydraulic system using the two hydraulic pumps are applied, the swivel device by the boom lift operation signal during the composite work by operating the boom and the swing lever operating lever at the same time according to the working conditions It is related to the hydraulic system for construction equipment, which is designed to improve the workability by controlling to reduce the amount of oil supplied to the engine and increasing the amount of oil supplied toward the boom to increase the boom driving speed.

Hydraulic system for construction equipment according to an embodiment of the present invention,

A variable displacement first hydraulic pump and a second hydraulic pump,

A first control valve for driving provided in the center bypass passage of the first hydraulic pump for controlling the starting, stopping, and direction change of the left traveling motor;

A first control valve installed in the center bypass passage downstream of the first control valve for traveling and connected through a parallel line, respectively, for controlling hydraulic oil supplied to the boom cylinder, the swing motor and the arm cylinder;

A second control valve for driving provided in the center bypass passage of the second hydraulic pump for controlling starting, stopping, and direction change of the right traveling motor;

A second control valve for a work device installed in the center bypass passage downstream of the second control valve for travel and connected through parallel lines, respectively, for controlling the hydraulic oil supplied to the boom cylinder, the bucket cylinder and the arm cylinder;

It is installed in the passage where one end is connected to the supply side port of the first control valve for the swing motor and the other end is connected to the parallel flow path, and the area of the passage is controlled according to the input amount of the boom lift control signal for controlling the first control valve for the boom. Including a boom priority control valve for controlling the amount of operating oil supplied to the first control valve for the swing motor,

In the combined operation of simultaneously operating the boom and the turning device, the boom lift control signal inputted to the boom priority control valve reduces the operating flow rate supplied from the first hydraulic pump to the swing motor, and relatively the boom cylinder from the first hydraulic pump. The operating speed of the boom cylinder is increased by increasing the working flow rate.

Hydraulic system for construction equipment according to an embodiment of the present invention configured as described above has the following advantages.

In construction equipment to which hydraulic system using two hydraulic pumps are applied, the operating pressure of boom and turning device is operated simultaneously according to the working condition, and the working flow rate supplied to the turning device by the boom raising operation signal is reduced during the compound work. By increasing the hydraulic oil supply toward the boom rise relatively, the workability can be improved by increasing the boom driving speed.

In addition, even when driving the boom and the swinging device at the same time it is possible to prevent the rapid rotation of the swinging device to ensure safety and reliability.

Hereinafter, preferred embodiments of the present invention will be described with reference to the accompanying drawings, which are intended to describe in detail enough to enable those skilled in the art to easily practice the invention, and therefore It does not mean that the technical spirit and scope of the present invention is limited.

Hydraulic system for construction equipment according to an embodiment of the present invention shown in Figure 2 (refer to the hydraulic system using two hydraulic pumps),

A variable displacement first hydraulic pump 50 and second hydraulic pump 51 (hereinafter referred to as a first hydraulic pump and a second hydraulic pump);

A first control valve 54 for driving provided in the center bypass passage 52 of the first hydraulic pump 50 for controlling the starting, stopping, and direction change of the left traveling motor 53;

It is installed in the center bypass passage 52 to the downstream side of the first control valve 54 for traveling and connected through the parallel line 55, respectively, the boom cylinder 64, the fixed displacement swing motor 56 and the arm cylinder. First control valves 68, 58, 59 for controlling the hydraulic oil supplied to the 57;

A second control valve 62 for traveling installed in the center bypass passage 60 of the second hydraulic pump 51 for controlling the starting, stopping, and direction change of the right traveling motor 61;

It is installed in the center bypass passage 60 to the downstream side of the second control valve 62 for travel and connected via the parallel line 63, respectively, the boom cylinder 64, the bucket cylinder 65 and the arm cylinder 57 Second control valves 66, 67, and 76 for the working device to control the hydraulic fluid supplied to

It is installed in the passage 100, one end of which is connected to the supply side port of the first control valve 58 for the swing motor, and the other end of which is connected to the parallel flow path 55, and the boom raising control signal (boom) through the signal pressure line 105. Including a boom priority control valve 102 for controlling the amount of operating oil supplied to the first control valve 58 for the swing motor by controlling the area of the passage 100 in accordance with the input of the up pilot signal,

In the combined operation of simultaneously operating the boom and the swinging device, the amount of operating fluid supplied from the first hydraulic pump 50 to the swinging motor 56 is reduced by the boom lift control signal input to the boom priority control valve 102, Relatively increasing the operating flow rate supplied to the boom cylinder 64 from the first hydraulic pump 50 to increase the drive speed of the boom cylinder (64).

At this time, in the combined operation of simultaneously operating the above-described boom and the turning device, the boom to reduce the operating flow rate supplied to the swing motor 56 and to increase the operating flow rate supplied to the boom cylinder 64 to increase the boom driving speed Since the configuration of the hydraulic system except for the priority control valve 102 is substantially the same as the configuration of the hydraulic system shown in FIG. 1, detailed descriptions of their configuration and operation are omitted, and overlapping reference numerals are denoted the same.

Hereinafter, with reference to the accompanying drawings an example of the use of the hydraulic system for construction equipment according to an embodiment of the present invention will be described in detail.

As shown in FIG. 2, as the first control valve 58 for the swing motor is switched to pivot the upper frame of the construction equipment with respect to the lower traveling body, the parallel flow path 55 from the first hydraulic pump 50 is changed. ) And the turning motor 56 may be driven by the hydraulic oil supplied through the boom priority control valve 102 designed to have a constant area. This allows the upper frame to pivot about the undercarriage of the excavator.

On the other hand, as the first control valve 68 for the boom is switched to the right in the drawing by the pilot signal pressure supplied through the signal pressure line 104 to drive the boom, the first hydraulic pump 50 The discharged hydraulic oil is supplied to the large chamber 64a of the boom cylinder 64 through the parallel passage 55, the first control valve 68, and the confluence passage 77.

In addition, as the second control valve 66 is switched to the left in the drawing, the hydraulic oil discharged from the second hydraulic pump 51 passes through the conduit 63 and the second control valve 66 for the boom. Joined to 77 is supplied to the large chamber 64a to the boom cylinder 64. At this time, the hydraulic oil from the small chamber 64b of the boom cylinder 64 is returned to the hydraulic tank via the second control valve 66 for boom.

Therefore, it is possible to secure the boom rising speed.

On the other hand, according to the working conditions to switch the first control valve 68 for the boom and the first control valve 58 for the swing motor in order to drive the boom and the swinging device at the same time to perform a combined operation, the first hydraulic pump A part of the hydraulic oil discharged from the 50 is supplied to the large chamber 64a of the boom cylinder 64 via the parallel passage 55, the first control valve 68, and the confluence passage 77. At the same time, a part of the hydraulic oil discharged from the first hydraulic pump 50 is supplied to the swing motor 56 via the parallel line 55, the supply line 100, and the first control valve 68.

At this time, the boom raising control signal for switching the first control valve 68 for the boom pressurizes the piston 106 through the signal pressure line 105 to increase the back pressure chamber pressure of the boom priority control valve 102.

As a result, the area of the passage 100 having one end connected to the supply side port of the first control valve 58 for the swinging motor is reduced. Therefore, the operating flow rate supplied to the swing motor 56 is reduced from the first hydraulic pump 50 via the first control valve 58 for the swing motor. On the other hand, the amount of hydraulic oil supplied from the first hydraulic pump 50 to the large chamber 64a of the boom cylinder 64 through the merging passage 77 via the first control valve 68 for the boom is relatively increased. .

On the other hand, when the pilot signal pressure is supplied to the right port of the first control valve 68 for the boom so as to deflate and drive the boom cylinder 64, the control valve 103 provided in the signal pressure line 104 is piloted from the outside. Since the signal pressure is switched downward in the figure, the hydraulic oil of the signal pressure line 104 is drained to the hydraulic tank.

Accordingly, since the first control valve 68 for the boom is switched to the left in the drawing, the hydraulic oil from the large chamber 64a of the boom cylinder 64 is drained to the hydraulic tank through the confluence passage 77.

As described above, the hydraulic system for construction equipment according to the embodiment of the present invention, in the hydraulic system using two hydraulic pumps that are universally applied to the construction equipment, the turning device in the combined operation to operate the boom and the turning device at the same time It is possible to improve workability by increasing the operating speed of the boom cylinder by reducing the amount of operating oil supplied to the boom and relatively increasing the amount of operating oil supplied to the boom.

1 is a schematic diagram of a hydraulic system for construction equipment according to the prior art,

2 is a hydraulic circuit diagram of a hydraulic system for construction equipment according to an embodiment of the present invention.

* Explanation of symbols used in the main part of the drawing

50; Variable displacement first hydraulic pump

51; Variable displacement type 2nd hydraulic pump

52,60; Center bypass passage

53; Left motor

56; Turning motor

58,59,68; 1st control valve

61; Right driving motor

64; Boom cylinder

77; Confluence

100; Passage

102; Boom priority control valve

103; Control valve

104; Signal line

105; Signal line

106; piston

Claims (1)

A variable displacement first hydraulic pump and a second hydraulic pump; A first control valve installed in a center bypass passage of the first hydraulic pump and configured to control start, stop, and direction change of the left driving motor; A first control valve installed in a center bypass passage downstream of the first control valve for driving and connected through a parallel line, respectively, for controlling hydraulic oil supplied to a boom cylinder, a swing motor, and an arm cylinder; A second control valve installed in the center bypass passage of the second hydraulic pump and configured to control start, stop and direction change of the right traveling motor; A second control valve for a work device installed in a center bypass passage downstream of the second control valve for driving and connected through a parallel line, respectively, for controlling hydraulic oil supplied to a boom cylinder, a bucket cylinder, and an arm cylinder; And The swing motor is provided in a passage where one end is connected to a supply side port of the first control valve for the swing motor and the other end is connected to the parallel flow path, and the boom lift control signal for controlling the first control valve for the boom is used for the swing motor. Including a boom priority control valve for controlling the amount of operating oil supplied to the first control valve, In the combined operation of simultaneously operating the boom and the swinging device, the amount of operating fluid supplied from the first hydraulic pump to the swinging motor is reduced by the boom raising control signal inputted to the boom priority control valve, and relatively from the first hydraulic pump. Hydraulic system for construction equipment, characterized in that to increase the operating flow rate supplied to the boom cylinder to increase the drive speed of the boom cylinder.
KR1020090129576A 2009-12-23 2009-12-23 Hydraulic system of construction equipment KR20110072587A (en)

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Applications Claiming Priority (1)

Application Number Priority Date Filing Date Title
KR1020090129576A KR20110072587A (en) 2009-12-23 2009-12-23 Hydraulic system of construction equipment

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Cited By (7)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
WO2013051741A1 (en) * 2011-10-07 2013-04-11 볼보 컨스트럭션 이큅먼트 에이비 Priority control system for construction machine
WO2015012423A1 (en) * 2013-07-24 2015-01-29 볼보 컨스트럭션 이큅먼트 에이비 Hydraulic circuit for construction machine
KR101532683B1 (en) * 2013-10-29 2015-07-01 국방과학연구소 Hydraulic system
WO2015099440A1 (en) * 2013-12-26 2015-07-02 두산인프라코어 주식회사 Method and apparatus for controlling main control valve of construction machine
WO2016208780A1 (en) * 2015-06-22 2016-12-29 볼보 컨스트럭션 이큅먼트 에이비 Hydraulic circuit for construction equipment
JP2019011792A (en) * 2017-06-29 2019-01-24 株式会社クボタ Hydraulic system of work machine
CN110645220A (en) * 2019-10-17 2020-01-03 江苏汇智高端工程机械创新中心有限公司 Hydraulic system for work vehicle and excavator

Cited By (13)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
WO2013051741A1 (en) * 2011-10-07 2013-04-11 볼보 컨스트럭션 이큅먼트 에이비 Priority control system for construction machine
CN103857850A (en) * 2011-10-07 2014-06-11 沃尔沃建造设备有限公司 Priority control system for construction machine
EP2765244A4 (en) * 2011-10-07 2015-05-27 Volvo Constr Equip Ab Priority control system for construction machine
US9651063B2 (en) 2011-10-07 2017-05-16 Volvo Construction Equipment Ab Priority control system for construction machine
WO2015012423A1 (en) * 2013-07-24 2015-01-29 볼보 컨스트럭션 이큅먼트 에이비 Hydraulic circuit for construction machine
KR101532683B1 (en) * 2013-10-29 2015-07-01 국방과학연구소 Hydraulic system
CN105899737A (en) * 2013-12-26 2016-08-24 斗山英维高株式会社 Method and apparatus for controlling main control valve of construction machine
WO2015099440A1 (en) * 2013-12-26 2015-07-02 두산인프라코어 주식회사 Method and apparatus for controlling main control valve of construction machine
US10385544B2 (en) 2013-12-26 2019-08-20 Doosan Infracore Co., Ltd. Method and device for controlling main control valve of construction machinery
WO2016208780A1 (en) * 2015-06-22 2016-12-29 볼보 컨스트럭션 이큅먼트 에이비 Hydraulic circuit for construction equipment
JP2019011792A (en) * 2017-06-29 2019-01-24 株式会社クボタ Hydraulic system of work machine
US11286645B2 (en) 2017-06-29 2022-03-29 Kubota Corporation Hydraulic system for working machine
CN110645220A (en) * 2019-10-17 2020-01-03 江苏汇智高端工程机械创新中心有限公司 Hydraulic system for work vehicle and excavator

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