CN108999843B - Amplitude falling hydraulic system and crane - Google Patents

Amplitude falling hydraulic system and crane Download PDF

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Publication number
CN108999843B
CN108999843B CN201811042179.1A CN201811042179A CN108999843B CN 108999843 B CN108999843 B CN 108999843B CN 201811042179 A CN201811042179 A CN 201811042179A CN 108999843 B CN108999843 B CN 108999843B
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oil
valve
amplitude
way
communicated
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CN108999843A (en
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杨耀祥
陆晓兵
黄孟
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Sany Automobile Hoisting Machinery Co Ltd
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Sany Automobile Hoisting Machinery Co Ltd
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    • 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
    • F15B21/00—Common features of fluid actuator systems; Fluid-pressure actuator systems or details thereof, not covered by any other group of this subclass
    • F15B21/001—Servomotor systems with fluidic control
    • B—PERFORMING OPERATIONS; TRANSPORTING
    • B66—HOISTING; LIFTING; HAULING
    • B66C—CRANES; LOAD-ENGAGING ELEMENTS OR DEVICES FOR CRANES, CAPSTANS, WINCHES, OR TACKLES
    • B66C23/00—Cranes comprising essentially a beam, boom, or triangular structure acting as a cantilever and mounted for translatory of swinging movements in vertical or horizontal planes or a combination of such movements, e.g. jib-cranes, derricks, tower cranes
    • B66C23/62—Constructional features or details
    • B66C23/82—Luffing gear
    • 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
    • F15B11/08—Servomotor systems without provision for follow-up action; Circuits therefor with only one servomotor
    • 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
    • F15B13/021—Valves for interconnecting the fluid chambers of an actuator

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  • Engineering & Computer Science (AREA)
  • Mechanical Engineering (AREA)
  • Physics & Mathematics (AREA)
  • Fluid Mechanics (AREA)
  • General Engineering & Computer Science (AREA)
  • Chemical & Material Sciences (AREA)
  • Analytical Chemistry (AREA)
  • Fluid-Pressure Circuits (AREA)

Abstract

The invention provides a falling amplitude hydraulic system and a crane, relating to the technical field of hoisting equipment thereof, wherein the falling amplitude hydraulic system comprises: the reversing valve is communicated with a rod cavity of the amplitude-variable oil cylinder through a first oil way, and the reversing valve is communicated with a rodless cavity of the amplitude-variable oil cylinder through a second oil way; the overflow valve is respectively communicated with the first oil way and the oil return tank through an overflow oil way. The amplitude falling hydraulic system provided by the invention relieves the technical problem of jitter generated in the amplitude falling process of the amplitude falling hydraulic system in the related technology.

Description

Amplitude falling hydraulic system and crane
Technical Field
The invention relates to the technical field of hoisting equipment, in particular to a amplitude falling system and a crane.
Background
At present, a small-tonnage automobile crane amplitude changing system adopts a power amplitude falling mode, a rod cavity of an amplitude changing oil cylinder is pressurized, the control pressure of a balance valve is derived from hydraulic oil introduced into the rod cavity when amplitude falls, and the opening of the balance valve is controlled to realize speed regulation.
When the automobile crane does amplitude falling motion, hydraulic oil enters the rod cavity of the amplitude-changing oil cylinder through the reversing valve, meanwhile, the valve core of the amplitude-changing balance valve is pushed to move, the valve port of the balance valve is opened, and the rodless cavity of the amplitude-changing oil cylinder returns oil through the reversing valve, so that amplitude falling is realized. The overflow valve plays a role of a safety valve, and the amplitude falling speed is realized by regulating the speed of the balance valve.
The drop-width hydraulic system in the related art has the following problems:
1. the amplitude of fall is opened and is easily caused instantaneous stall, and at the moment, the pressure of the oil circuit with the rod cavity is instantly reduced, the control oil circuit loses pressure, the opening of the main valve core of the balance valve is reduced, the amplitude of fall is reduced, the oil supply of the rod cavity is sufficient, the pressure of the control oil circuit is increased, and the opening of the valve core is suddenly increased, so that continuous jitter is generated.
2. The balance valve needs to realize speed regulation, and the valve core structure of the balance valve is complex, long in stroke and high in manufacturing cost.
Disclosure of Invention
The invention aims to provide a dropping amplitude hydraulic system to relieve the technical problem of shaking generated in the dropping amplitude process of the dropping amplitude hydraulic system in the related art.
The invention provides a hydraulic system for amplitude falling, which comprises: the reversing valve is communicated with a rod cavity of the variable amplitude oil cylinder through a first oil way, and the reversing valve is communicated with a rodless cavity of the variable amplitude oil cylinder through a second oil way;
the overflow valve is respectively communicated with the first oil way and the oil return tank through an overflow oil way.
Optionally, a first oil port of the reversing valve is communicated with the first oil path, a second oil port of the reversing valve is communicated with the second oil path, and a third oil port of the reversing valve and a fourth oil port of the reversing valve are both communicated with an oil tank.
Optionally, the reversing valve is a manual reversing valve.
Optionally, the reversing valve is a three-position four-way valve.
Optionally, the amplitude falling hydraulic system further includes a balancing assembly, and the balancing assembly is disposed on the second oil path and is communicated with the first oil path.
Optionally, the balance assembly includes a variable amplitude balance valve, and the variable amplitude balance valve is disposed in the second oil path and is communicated with the first oil path;
and a balance valve core is arranged in the amplitude-variable balance valve, hydraulic oil in the first oil way generates acting force on the first end of the balance valve core, and hydraulic oil in the second oil way and an elastic piece in the amplitude-variable balance valve generate acting force on the second end of the balance valve core.
Optionally, the variable amplitude balance valve is provided with a first cavity and a second cavity therein, the first cavity is communicated with the first oil path, the second cavity is communicated with the second oil path, and the balance valve core is used for isolating the first cavity from the second cavity.
Optionally, the balancing assembly includes a hydraulic control check valve, and the hydraulic control check valve is disposed in the second oil path and is communicated with the first oil path;
the hydraulic control one-way valve can be opened by hydraulic oil in the first oil way and hydraulic oil in the second oil way.
The invention aims to provide a web drop control method, which comprises the following steps:
controlling the first oil way to be an oil inlet oil way and the second oil way to be an oil return oil way through a reversing valve, or controlling the second oil way to be an oil inlet oil way and the first oil way to be an oil return oil way;
the amplitude falling speed is adjusted by adjusting a valve core of the reversing valve.
The invention also aims to provide a crane comprising the amplitude falling hydraulic system.
The invention provides a hydraulic system for amplitude falling, which comprises: the reversing valve is communicated with a rod cavity of the amplitude-variable oil cylinder through a first oil way, and the reversing valve is communicated with a rodless cavity of the amplitude-variable oil cylinder through a second oil way; the overflow valve is respectively communicated with the first oil way and the oil return tank through an overflow oil way. The flow direction and the flow rate of the hydraulic oil in the first oil path and the second oil path are changed through the reversing valve; when the amplitude falls, the reversing valve is adjusted, the first oil way is an oil inlet oil way, the second oil way is an oil return oil way, when a valve core of the reversing valve is opened to the maximum position, the pressure in the first oil way is equal to the overflow pressure of the overflow valve, and the flow of hydraulic oil in the first oil way is controlled by controlling the opening size of the reversing valve, so that the amplitude falling speed is controlled and is irrelevant to the load.
Drawings
In order to more clearly illustrate the technical solutions of the embodiments of the present invention or related technologies, the drawings used in the description of the embodiments or related technologies will be briefly introduced below, and it is obvious that the drawings in the following description are some embodiments of the present invention, and other drawings can be obtained by those skilled in the art without creative efforts.
Fig. 1 is a first schematic structural diagram of a boom lowering hydraulic system according to an embodiment of the present invention;
fig. 2 is a schematic structural diagram ii of a boom drop hydraulic system according to an embodiment of the present invention.
Icon: 100-variable amplitude oil cylinder; 200-a reversing valve; 300-an overflow valve; 400-a first oil path; 500-a second oil path; 600-a variable amplitude balance valve; 700-hydraulic control one-way valve; v1-first oil port; v2-second oil port; p-a third oil port; t-fourth oil port.
Detailed Description
The technical solutions of the present invention will be described clearly and completely with reference to the accompanying drawings, and it should be understood that the described embodiments are some, but not all embodiments of the present invention. All other embodiments, which can be derived by a person skilled in the art from the embodiments given herein without making any creative effort, shall fall within the protection scope of the present invention.
In the description of the present invention, it should be noted that the terms "center", "upper", "lower", "left", "right", "vertical", "horizontal", "inner", "outer", etc., indicate orientations or positional relationships based on the orientations or positional relationships shown in the drawings, and are only for convenience of description and simplicity of description, but do not indicate or imply that the device or element being referred to must have a particular orientation, be constructed and operated in a particular orientation, and thus, should not be construed as limiting the present invention. Furthermore, the terms "first," "second," and "third" are used for descriptive purposes only and are not to be construed as indicating or implying relative importance.
In the description of the present invention, it should be noted that, unless otherwise explicitly specified or limited, the terms "mounted," "connected," and "connected" are to be construed broadly, e.g., as meaning either a fixed connection, a removable connection, or an integral connection; can be mechanically or electrically connected; they may be connected directly or indirectly through intervening media, or they may be interconnected between two elements. The specific meanings of the above terms in the present invention can be understood in specific cases to those skilled in the art.
The hydraulic system that falls a width of cloth that embodiment of this invention provides includes: the variable-amplitude oil cylinder 100, the reversing valve 200 and the overflow valve 300, wherein the reversing valve 200 is communicated with a rod cavity of the variable-amplitude oil cylinder 100 through a first oil way 400, and the reversing valve 200 is communicated with a rodless cavity of the variable-amplitude oil cylinder 100 through a second oil way 500;
the relief valve 300 is communicated with the first oil passage 400 and the oil return tank through relief oil passages, respectively.
Specifically, the reversing valve 200 has a first port V1, a second port V2, a third port P, and a fourth port T, the first port V1 of the reversing valve 200 is communicated with the first oil path 400, the second port V2 of the reversing valve 200 is communicated with the second oil path 500, and both the third port P of the reversing valve 200 and the fourth port T of the reversing valve 200 are communicated with the oil tank.
Optionally, the directional valve 200 is a manual directional valve 200.
An operator can manually adjust the reversing valve 200 to change the state of the hydraulic oil in the first oil path 400 and the second oil path 500, so that the amplitude-dropping hydraulic system can be adjusted.
Optionally, the directional valve 200 is a three-position four-way valve.
An operator can change the connection and disconnection conditions of the first oil port V1, the second oil port V2, the third oil port P and the fourth oil port T by adjusting the position of the valve core, so that the flowing state of hydraulic oil in the first oil path 400 and the second oil path 500 is changed, and the adjustment of the amplitude-falling hydraulic system is realized.
Optionally, the amplitude-dropping hydraulic system further includes a balancing assembly, and the balancing assembly is disposed in the second oil path 500 and is communicated with the first oil path 400.
Specifically, the balance assembly is respectively communicated with the first oil path 400 and the second oil path 500, the hydraulic oil in the rodless cavity passes through the balance assembly and then flows into the reversing valve 200, and both the hydraulic oil in the first oil path 400 and the hydraulic oil in the second oil path 500 generate acting force on the balance assembly. The balance assembly balances the first oil path 400 and the second oil path 500, and improves the stability during amplitude falling.
As shown in fig. 1, the balancing assembly includes a variable amplitude balancing valve 600, and the variable amplitude balancing valve 600 is disposed in the second oil passage 500 and is communicated with the first oil passage 400;
a balance valve core is arranged in the variable amplitude balance valve 600, hydraulic oil in the first oil path 400 generates acting force on a first end of the balance valve core, and hydraulic oil in the second oil path 500 and an elastic element in the variable amplitude balance valve 600 generate acting force on a second end of the balance valve core.
Specifically, the variable amplitude balance valve 600 has a housing and a balance valve core, the balance valve core can move in the housing, the first oil path 400 is communicated with the interior of the housing, and the hydraulic oil in the first oil path 400 generates acting force on a first end surface of the balance valve core; the second oil path 500 is communicated with the shell, hydraulic oil in the second oil path 500 flows into the reversing valve 200 through the shell, and the reversing valve 200 returns oil and throttles to generate acting force on the second end face of the balance valve core; and a spring is arranged between the balance valve core and the inner wall of the shell and generates acting force on the second end surface of the balance valve core.
In the amplitude falling process, the reversing valve 200 is adjusted to the leftmost position, the pressure of the hydraulic oil in the first oil path 400 is directly increased to the overflow pressure Pc of the overflow valve 300, the amplitude-changing balance valve 600 is fully opened, and the oil return throttling function of the reversing valve 200 generates corresponding back pressure Pa. When the pressure of the first end surface of the variable amplitude balance valve 600 reaches the resultant force of the main valve core spring force Ft of the variable amplitude balance valve 600 and the return oil back pressure Pa of the hand valve 200, the balance valve core of the variable amplitude balance valve 600 reaches mechanical balance:
pc × a ═ Ft + Pa × a, available as such;
Pa＝Pc－Ft/A
the relief valve 300 functions as a pressure stabilizing valve, and the set pressure Pc is a constant value, and Pa is a constant value as can be seen from the above calculation.
The flow rate in the first oil passage 400 is:
Figure BDA0001793170070000071
wherein Q is the flow rate in the first oil passage 400;
c is a flow coefficient;
Apthe oil return throttling area of the reversing valve 200 is determined by the valve core position of the reversing valve 200;
ρ is the density of the hydraulic oil.
The flow rate of the hydraulic oil in the first oil passage 400 is determined by the oil return restriction area of the selector valve 200, and is independent of the load, so that the amplitude falling speed can be controlled by adjusting the spool position of the selector valve 200.
Optionally, the variable amplitude balance valve 600 has a first cavity and a second cavity therein, the first cavity is communicated with the first oil path 400, the second cavity is communicated with the second oil path 500, and the balance valve core is used for isolating the first cavity from the second cavity.
Hydraulic oil in the first oil path 400 enters the first cavity to generate acting force on the first end face of the balanced valve core; hydraulic oil in the rodless cavity of the amplitude cylinder 100 flows back to the reversing valve 200 through the second cavity, the reversing valve 200 generates corresponding back pressure under the action of oil return throttling, the back pressure acts on the second end face of the balance valve core, the spring is located in the second cavity, and when the spring generates elastic deformation, acting force is generated on the second end face of the balance valve core; the balance valve core moves between the first cavity and the second cavity according to forces received by the two ends, and the balance in the first oil path 400 and the second oil path 500 is adjusted, so that the amplitude of the oil drops more stably.
Optionally, the balancing assembly includes a pilot operated check valve 700, and the pilot operated check valve 700 is disposed in the second oil passage 500 and is communicated with the first oil passage 400;
the pilot operated check valve 700 may be opened by both the hydraulic oil in the first oil passage 400 and the hydraulic oil in the second oil passage 500.
As shown in fig. 2, the hydraulic oil in the first oil path 400 can enter the pilot-controlled check valve 700, so that the spool of the pilot-controlled check valve 700 is opened; alternatively, when the hydraulic oil in the second oil path 500 flows from the bottom to the top, the spool of the pilot operated check valve 700 is opened. The pilot operated check valve 700 balances the first oil passage 400 and the second oil passage 500, and improves the stability of the amplitude drop.
The purpose of the embodiment of the invention comprises providing a cropping control method, which comprises the following steps:
controlling the first oil path 400 to be an oil inlet path and the second oil path 500 to be an oil return path through the reversing valve 200, or controlling the second oil path 500 to be an oil inlet path and the second oil path 500 to be an oil return path;
the amplitude falling speed is adjusted by adjusting the spool of the directional valve 200.
Specifically, during amplitude dropping, the spool of the reversing valve 200 is located at the left position, the first oil path 400 is an oil inlet path, and the second oil path 500 is an oil return path; when the hydraulic rod of the variable amplitude oil cylinder 100 moves upwards, the valve core of the reversing valve 200 is positioned at the right position, the second oil path 500 is an oil inlet path, and the first oil path 400 is an oil return path; when the hydraulic rod needs to be balanced, the valve core of the reversing valve 200 is located at the middle position, and the first oil path 400 and the second oil path 500 are both oil inlet paths. During amplitude falling, the amplitude falling speed of the amplitude falling hydraulic system is adjusted by adjusting the throttling area of the reversing valve 200, and the amplitude falling stability is improved.
The embodiment of the invention also aims to provide a crane, which comprises the amplitude falling hydraulic system.
Specifically, the hydraulic amplitude falling system is arranged in the crane, and when the crane performs amplitude falling operation, the amplitude falling speed is adjusted through the reversing valve 200, so that the amplitude falling stability is improved.
The hydraulic system that falls a width of cloth that embodiment of this invention provides includes: the variable-amplitude oil cylinder 100, the reversing valve 200 and the overflow valve 300, wherein the reversing valve 200 is communicated with a rod cavity of the variable-amplitude oil cylinder 100 through a first oil way 400, and the reversing valve 200 is communicated with a rodless cavity of the variable-amplitude oil cylinder 100 through a second oil way 500; the relief valve 300 is communicated with the first oil passage 400 and the oil return tank through relief oil passages, respectively. The flow direction and the flow rate of the hydraulic oil in the first oil passage 400 and the second oil passage 500 are changed by the selector valve 200; when the amplitude falls, the reversing valve 200 is adjusted, the first oil path 400 is an oil inlet path, the second oil path 500 is an oil return path, when the valve core of the reversing valve 200 is opened to the maximum position, the pressure in the first oil path 400 is equal to the overflow pressure of the overflow valve 300, the flow of hydraulic oil in the first oil path 400 is controlled by controlling the opening size of the reversing valve 200, and therefore the amplitude falling speed is controlled and is independent of the load.
Finally, it should be noted that: the above embodiments are only used to illustrate the technical solution of the present invention, and not to limit the same; while the invention has been described in detail and with reference to the foregoing embodiments, it will be understood by those skilled in the art that: the technical solutions described in the foregoing embodiments may still be modified, or some or all of the technical features may be equivalently replaced; and the modifications or the substitutions do not make the essence of the corresponding technical solutions depart from the scope of the technical solutions of the embodiments of the present invention.

Claims (7)

1. A drop amplitude hydraulic system, comprising: the reversing valve is communicated with a rod cavity of the variable amplitude oil cylinder through a first oil way, and the reversing valve is communicated with a rodless cavity of the variable amplitude oil cylinder through a second oil way;
the overflow valve is respectively communicated with the first oil way and the oil return tank through an overflow oil way;
the amplitude falling hydraulic system also comprises a balance assembly, and the balance assembly is arranged on the second oil way and is communicated with the first oil way;
the balance assembly comprises a variable amplitude balance valve, and the variable amplitude balance valve is arranged on the second oil way and communicated with the first oil way;
a balance valve core is arranged in the amplitude-variable balance valve, acting force of hydraulic oil in the first oil way on the first end of the balance valve core is Pc × A, acting force of hydraulic oil in the second oil way and acting force of an elastic element in the amplitude-variable balance valve on the second end of the balance valve core are Pa × A and Ft respectively, and when amplitude falls, Pc × A is equal to Ft + Pa × A;
wherein Pc is the overflow pressure of the overflow valve, Pa is the back pressure generated by the oil return throttling action of the reversing valve, and A is the area of the end face of the balance valve core;
the variable amplitude balance valve is internally provided with a first cavity and a second cavity, the first cavity is communicated with the first oil way, the second cavity is communicated with the second oil way, and the balance valve core is used for isolating the first cavity from the second cavity.
2. The amplitude hydraulic system according to claim 1, wherein a first oil port of the reversing valve is communicated with the first oil path, a second oil port of the reversing valve is communicated with the second oil path, and a third oil port of the reversing valve and a fourth oil port of the reversing valve are both communicated with an oil tank.
3. The framing hydraulic system of claim 2, wherein the directional valve is a manual directional valve.
4. The framing hydraulic system of claim 3, wherein the reversing valve is a three-position, four-way valve.
5. The drop amplitude hydraulic system of claim 1, wherein the balancing assembly comprises a pilot operated check valve disposed in the second oil passage and in communication with the first oil passage;
the hydraulic control one-way valve can be opened by hydraulic oil in the first oil way and hydraulic oil in the second oil way.
6. A drop width control method using the drop width hydraulic system according to any one of claims 1 to 5, comprising:
controlling the first oil way to be an oil inlet oil way and the second oil way to be an oil return oil way through a reversing valve, or controlling the second oil way to be an oil inlet oil way and the first oil way to be an oil return oil way;
the amplitude falling speed is adjusted by adjusting a valve core of the reversing valve;
the variable amplitude balance valve on the second oil way achieves mechanical balance under the elastic force of an internal spring, the overflow pressure of the overflow valve and the back pressure generated by the oil return throttling action of the reversing valve.
7. A crane, characterized by comprising the drop amplitude hydraulic system of any one of claims 1-5.
CN201811042179.1A 2018-09-07 2018-09-07 Amplitude falling hydraulic system and crane Active CN108999843B (en)

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CN113479800B (en) * 2021-07-30 2023-08-22 三一汽车起重机械有限公司 Amplitude falling control method and system and crane

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* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
CH543028A (en) * 1972-11-09 1973-10-15 Beringer Hydraulik Gmbh Hydraulic lowering brake shut-off valve
DE3420890A1 (en) * 1984-06-05 1985-12-05 Gewerkschaft Eisenhütte Westfalia, 4670 Lünen Pressure-relief valve, in particular for hydraulic telescopic props and the like
CN2625680Y (en) * 2003-07-04 2004-07-14 天津特***压股份有限公司 Plug-in mounting straight moving type dual-purpose safety valve controlling balance inside and outside
CN101634317B (en) * 2009-08-21 2011-12-28 宁波汉商液压有限公司 Plug-in type balance valve
CN104879334B (en) * 2015-04-23 2017-08-04 凯迈（洛阳）测控有限公司 Piston elevating mechanism and its hydraulic control device
CN205187683U (en) * 2015-11-20 2016-04-27 徐州重型机械有限公司 Hoist, jib loading boom system and hydraulic control system
CN107781250A (en) * 2016-08-29 2018-03-09 何志杰 Novel load sensitive balance valve

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