CN110454457B - Flow unloading valve and hydraulic driving system of hydraulic excavator - Google Patents

Flow unloading valve and hydraulic driving system of hydraulic excavator Download PDF

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Publication number
CN110454457B
CN110454457B CN201910778815.5A CN201910778815A CN110454457B CN 110454457 B CN110454457 B CN 110454457B CN 201910778815 A CN201910778815 A CN 201910778815A CN 110454457 B CN110454457 B CN 110454457B
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valve rod
annular groove
communicated
valve
oil
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CN110454457A (en
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胡建军
陈登民
景军清
戚振红
赵鑫拓
吕德滨
何伟
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Xuzhou Amakai Hydraulic Technology Co ltd
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Xuzhou Amakai Hydraulic Technology Co ltd
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    • 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
    • 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
    • F15B13/023—Excess flow valves, e.g. for locking cylinders in case of hose burst
    • 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
    • F15B13/16—Special measures for feedback, e.g. by a follow-up device

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  • Engineering & Computer Science (AREA)
  • General Engineering & Computer Science (AREA)
  • Physics & Mathematics (AREA)
  • Fluid Mechanics (AREA)
  • Mechanical Engineering (AREA)
  • Mining & Mineral Resources (AREA)
  • Civil Engineering (AREA)
  • Structural Engineering (AREA)
  • Servomotors (AREA)
  • Operation Control Of Excavators (AREA)

Abstract

The invention discloses a flow unloading valve and a hydraulic driving system of a hydraulic excavator. The valve body is provided with an upper valve core hole and a lower valve core hole which penetrate through the valve body and are symmetrically arranged; an upper left screw plug, an upper spring, an upper valve rod and an upper right screw plug are sequentially arranged in the upper valve core hole; an oil port XBP1 communicated with the upper left spring cavity g, an oil port A communicated with the first annular groove of the upper valve rod, an oil port N1 communicated with the second annular groove of the upper valve rod and an oil port Dr communicated with the third annular groove of the upper valve rod are formed in the valve body; the bottom of the first annular groove of the upper valve rod is provided with an oil duct b communicated with the upper right cavity a; a long hole c for communicating the upper left spring cavity g and the upper right accommodating cavity a is formed in the upper valve rod; the negative flow control multi-way valve realizes the unification of the structure and the function of the negative flow control multi-way valve and hydraulic drive control signals, simplifies the complexity, simplifies the structural form of an oil way, improves the sensitivity of system response, reduces the processing difficulty of parts, reduces the duty ratio and realizes the purpose of slimming the hydraulic drive system of the hydraulic excavator.

Description

Flow unloading valve and hydraulic driving system of hydraulic excavator
Technical Field
The invention relates to a hydraulic valve for engineering machinery and a hydraulic drive system of a hydraulic excavator.
Background
The application environment of the engineering machinery is severe, the working condition is complex, and the uncontrollable factors are more; with the rapid development of engineering machinery, the requirements on indexes of the engineering machinery, such as energy-saving effect, control comfort and the like, are higher and higher. High requirements are also placed on the weight reduction and duty ratio of parts, and higher requirements are also placed on the responsiveness of parts.
Chinese patent discloses an unloading valve and an oil pressure driving system (CN 105909588A) of an oil hydraulic excavator, which provides a single unloading valve provided on a first circulation line and a second circulation line. An unloading valve provided in a first circulation line and a second circulation line in a hydraulic drive system of a construction machine is provided with: a housing having a first pump port on the pump side as the first circulation line, a first output port on the throttle side as the first circulation line, a second pump port on the pump side as the second circulation line, a second output port on the throttle side as the second circulation line, and a tank port; and a spool held in the housing and movable between a normal position at which the first pump port communicates with the first output port and the second pump port communicates with the second output port, and an unload position at which the first pump port and the second pump port communicate with the tank port.
The above technology has the following disadvantages:
1. the oil pressure driving of the unloading valve and the oil pressure excavator mentioned in the patent has the disadvantages of complex oil path structure, difficult processing, more parts and complex and complicated assembly process;
2. the unloading valve and the hydraulic drive of the hydraulic excavator described in the patent have heavier valve body and larger volume, which is not beneficial to the light weight of the excavator;
3. the unloading valve and the oil pressure drive of the oil pressure excavator described in the patent have the disadvantages of complex oil path structure, large oil pressure loss and slow response;
4. the unloading valve and the hydraulic drive of the hydraulic excavator described in the patent are dedicated unloading and hydraulic drive of the hydraulic excavator, and one mechanism cannot be adapted to various systems, which is not favorable for popularization of the negative flow control multi-way valve.
Disclosure of Invention
In order to solve the technical problems, the invention provides a flow unloading valve and a hydraulic driving system of a hydraulic excavator, wherein the flow unloading valve combines an unloading valve, a confluence valve (a cut-off valve) and a hydraulic driving control signal, simplifies an oil path and improves the response sensitivity of the system.
The invention is realized by the following technical scheme: a flow unloading valve comprises a valve body; the valve body is provided with an upper valve core hole and a lower valve core hole which penetrate through the valve body;
an upper left screw plug, an upper spring, an upper valve rod and an upper right screw plug are sequentially arranged in the upper valve core hole; the left end of the upper valve rod is provided with an upper left spring cavity g, and the right end of the upper valve rod is provided with an upper right containing cavity a; a first annular groove, a second annular groove and a third annular groove are sequentially formed in the upper valve rod from left to right; an oil port XBP1 communicated with the upper left spring cavity g is formed in the valve body; the valve body is provided with an oil port A communicated with the first annular groove of the upper valve rod, an oil port N1 communicated with the second annular groove of the upper valve rod, and an oil port Dr communicated with the third annular groove of the upper valve rod; the bottom of the first annular groove of the upper valve rod is provided with an oil duct b communicated with the upper right cavity a; a throttling groove is formed in the right side of the second annular groove of the upper valve rod; a long hole c for communicating the upper left spring cavity g and the upper right accommodating cavity a is formed in the upper valve rod; the left end of the long hole c is provided with a section of sliding hole with the diameter larger than that of the long hole c, and an upper floating damper is installed in the sliding hole in a sliding mode;
a lower left screw plug, a lower spring, a lower valve rod and a lower right screw plug are sequentially arranged in the lower valve core hole; the left end of the lower valve rod is provided with a lower left spring cavity h, and the right end of the lower valve rod is provided with a lower right containing cavity d; a first annular groove, a second annular groove and a third annular groove are sequentially formed in the lower valve rod from left to right; an oil port XBP2 communicated with the lower left spring cavity h is formed in the valve body; an oil port B communicated with the first annular groove of the lower valve rod is formed in the valve body, an oil port N2 communicated with the second annular groove of the lower valve rod is formed in the valve body, and an oil port Dr in the valve body is communicated to a third annular groove of the lower valve rod; the bottom of the first annular groove of the lower valve rod is provided with an oil duct e communicated to the lower right cavity d; a throttling groove is formed in the right side of the second annular groove of the lower valve rod; a long hole f for communicating the lower left spring cavity h and the lower right accommodating cavity d is formed in the lower valve rod; the left end of the long hole f is provided with a section of sliding hole with the diameter larger than that of the long hole f, and a lower floating damper is installed in the sliding hole in a sliding mode.
It further comprises the following steps: an upper spring pad is arranged on the inner end face of the upper left screw plug, and the left end of the upper spring is mounted on the upper spring pad; the axis of the upper left screw plug is provided with a threaded through hole, and an upper adjusting screw is arranged in the threaded through hole of the upper left screw plug; the inner end of the upper adjusting screw abuts against the left side of the upper spring pad, and the outer end of the upper adjusting screw is provided with an upper locking nut.
The upper spring is covered by an upper sleeve, and the circumferential surface of the middle part of the upper sleeve is provided with an oil through hole communicated with the oil hole XBP 1; the periphery of the upper spring pad is in sliding fit with the inner wall of the upper sleeve, the left end of the upper sleeve abuts against the inner side face of the upper left screw plug, and the right end of the upper sleeve is opposite to the upper valve rod and is provided with a gap.
And a fourth annular groove is formed in the right side of the third annular groove in the upper valve rod, and an oil hole communicated with the oil duct b is formed in the bottom of the fourth annular groove in the upper valve rod.
The inner end surface of the lower left screw plug is provided with a lower spring pad, and the left end of the lower spring is arranged on the lower spring pad; the axis of the lower left screw plug is provided with a threaded through hole, and a lower adjusting screw is arranged in the threaded through hole of the lower left screw plug; the inner end of the lower adjusting screw abuts against the left side of the lower spring pad, and the outer end of the lower adjusting screw is provided with an upper locking nut.
The lower spring is covered by a lower sleeve, and the circumferential surface of the middle part of the lower sleeve is provided with an oil through hole communicated with the oil hole XBP 2; the circumferential surface of the lower spring pad is in sliding fit with the inner wall of the lower sleeve, the left end of the lower sleeve abuts against the inner side surface of the lower left screw plug, and the right end of the lower sleeve is opposite to the lower valve rod and is provided with a gap.
And a fourth annular groove is formed in the right side of the third annular groove in the lower valve rod, and an oil hole communicated with the oil duct e is formed in the bottom of the fourth annular groove in the lower valve rod.
A hydraulic drive system of a hydraulic excavator comprises a flow unloading valve; the oil port A is communicated with a variable pump source P1 through a multiway valve, and the oil port B is communicated with a variable pump source P2 through the multiway valve; the oil port N1 is connected with an adjusting mechanism of a variable pump source P1, and the oil port N2 is connected with an adjusting mechanism of a variable pump source P2; the oil port Dr is connected with an oil tank; the oil port XBP1 and the oil port XBP2 are connected with a pilot oil source.
Compared with the prior art, the invention has the beneficial effects that:
1, automatic control of a hydraulic drive system can be realized, and an external pilot pressure and other auxiliary control mechanisms are not needed;
2, combining the flow unloading valve and the excavator hydraulic driving mechanism with the mechanism of the load sensitive system to realize the function and performance of the negative flow control system;
3, by utilizing the working characteristics of the negative flow control multi-way valve of the excavator under the idle working condition and utilizing the structural form and function of the two-position two-way valve to replace an unloading valve and a converging valve (cut-off valve) structure, the unification of the structure and function of the negative flow control multi-way valve and hydraulic drive control signals is realized, the complexity is simplified, the structural form of an oil way is simplified, the sensitivity of system response is improved, the processing difficulty of parts is reduced, the duty ratio is reduced, and the purpose of slimming of a hydraulic drive system of the hydraulic excavator is realized;
4, the system can correspond to negative flow control systems of different models, realizes one-to-many, and reduces cost in various aspects such as research and development, manufacture and the like.
Drawings
FIG. 1 is a front view of the present invention;
FIG. 2 is a front view of the valve body;
FIG. 3 is a schematic diagram of a hydraulic drive system;
in the figure: the valve comprises a valve body 1, a lower locking nut 2, a lower adjusting screw 3, a lower left plug screw 4, an upper spring pad 5, an upper sleeve 6, an upper spring 7, an upper valve rod 8 and an upper right plug screw 9; the upper left screw plug 10, the lower spring pad 11, the lower spring 12, the lower sleeve 13, the lower valve rod 14, the lower right screw plug 15, the upper locking nut 16 and the upper adjusting screw 17.
Detailed Description
The following are specific embodiments of the present invention, and the present invention will be further described with reference to the accompanying drawings.
Example one
Referring to fig. 1 and 2, an upper valve core hole and a lower valve core hole penetrating through a valve body 1 are formed in the valve body 1.
An upper left screw plug 10, an upper spring 7, an upper valve rod 8 and an upper right screw plug 9 are sequentially arranged in the upper valve core hole, the left end of the upper valve rod 8 is provided with an upper left spring cavity g, and the right end of the upper valve rod 8 is provided with an upper right accommodating cavity a. In order to adjust the pressure of the upper spring 7 conveniently, the upper spring pad 5 is arranged on one side of the inner end face of the upper left screw plug 10, and the left end of the upper spring 7 is installed on the upper spring pad 5; the axle center of the upper left screw plug 10 is provided with a threaded through hole, an adjusting screw 17 is arranged in the threaded through hole of the upper left screw plug 10, the inner end of the upper adjusting screw 17 abuts against the left side of the upper spring pad 5, and the outer end of the upper adjusting screw 17 is provided with a locking nut 16. An upper sleeve 6 is covered outside the upper spring 7, and an oil through hole communicated with the oil hole XBP1 is formed in the circumferential surface of the middle part of the upper sleeve 6; the circumferential surface of the upper spring pad 5 is in sliding fit with the inner wall of the upper sleeve 6, the left end of the upper sleeve 6 is propped against the inner side surface of the upper left screw plug 10, and the right end of the upper sleeve 6 is opposite to the upper valve rod 8 with a gap.
A first annular groove, a second annular groove, a third annular groove and a fourth annular groove are sequentially formed in the upper valve rod 8 from left to right, and a throttling groove is formed in the right side of the second annular groove of the upper valve rod 8. The valve body 1 is provided with an XBP1, an oil port A, an oil port N1 and an oil port Dr. The oil port XBP1 is communicated with the upper left spring cavity g; the oil port A is communicated with a first annular groove of the upper valve rod 8; the oil port N1 is communicated with a second annular groove of the upper valve rod 8; the oil port Dr has a third annular groove with the upper valve stem 8. An oil duct b communicated with the upper right cavity a is formed at the bottom of the first annular groove of the upper valve rod 8, and an oil hole communicated with the oil duct b is formed at the bottom of the fourth annular groove of the upper valve rod 8.
A long hole c communicated with the upper left spring cavity g and the upper right accommodating cavity a is formed in the upper valve rod 8; the left end of the long hole c is provided with a section of sliding hole with the diameter larger than that of the long hole c, and an upper floating damper is installed in the sliding hole in a sliding mode.
The lower valve core hole is sequentially provided with a lower left plug screw 4, a lower spring 12, a lower valve rod 14 and a lower right plug screw 15, the left end of the lower valve rod 14 is provided with a lower left spring cavity h, and the right end of the lower valve rod 14 is provided with a lower right cavity d. In order to adjust the pressure of the lower spring 12 conveniently, a lower spring pad 11 is arranged on one side of the inner end face of the lower left screw plug 4, and the left end of the lower spring 12 is installed on the lower spring pad 11; the axle center of the lower left screw plug 4 is provided with a threaded through hole, and the lower left screw plug 4 is provided with a lower adjusting screw 3 in the threaded through hole. The inner end of the lower adjusting screw 3 is abutted against the left side of the lower spring pad 11, and the outer end of the lower adjusting screw 3 is provided with an upper locking nut 2. The lower spring 12 is covered by a lower sleeve 13, and the circumferential surface of the middle part of the lower sleeve 13 is provided with an oil through hole communicated with an oil hole XBP 2; the circumferential surface of the lower spring pad 11 is in sliding fit with the inner wall of the lower sleeve 13, the left end of the lower sleeve 13 is abutted against the inner side surface of the lower left screw plug 4, and the right end of the lower sleeve 13 is opposite to the lower valve rod 14 with a gap.
The lower valve rod 14 is provided with a first annular groove, a second annular groove, a third annular groove and a fourth annular groove from left to right in sequence, and the right side of the second annular groove of the lower valve rod 14 is provided with a throttling groove. An oil port XBP2, an oil port B and an oil port N2 are formed in the valve body 1; an oil port XBP2 is communicated with the lower left spring cavity h, and an oil port B is communicated with the first annular groove of the lower valve rod 14; the port N2 communicates with the second annular groove of the lower stem 14. The oil port Dr is simultaneously communicated to a third annular groove of the lower valve rod 14. An oil passage e communicated with the lower right cavity d is formed in the bottom of the first annular groove of the lower valve rod 14, and an oil hole communicated with the oil passage e is formed in the bottom of the fourth annular groove of the lower valve rod 14.
A long hole f for communicating the lower left spring cavity h and the lower right accommodating cavity d is formed in the lower valve rod 14; the left end of the long hole f is provided with a section of sliding hole with the diameter larger than that of the long hole f, and a lower floating damper is installed in the sliding hole in a sliding mode.
Example two
In addition to the first embodiment, with reference to fig. 3, a hydraulic drive system of a hydraulic excavator:
the oil port A is communicated with a variable pump source P1 through a multiway valve, and the oil port B is communicated with a variable pump source P2 through the multiway valve; the oil port N1 is connected with an adjusting mechanism of a variable pump source P1, and the oil port N2 is connected with an adjusting mechanism of a variable pump source P2; the oil port Dr is connected with an oil tank; the oil port XBP1 and the oil port XBP2 are connected with a pilot oil source.
The working principle is as follows:
1. when the system is in an initial state, the hydraulic pump discharges no flow, the upper valve rod and the lower valve rod are in initial positions under the action of upper and lower spring forces, the A, B accommodating cavity is not communicated with the N1 accommodating cavity and the N2 accommodating cavity under the matching of the valve rod and the valve core hole, and the N1 accommodating cavity and the N2 accommodating cavity are communicated with the Dr accommodating cavity through the throttling groove on the valve rod step shaft.
2. When the pumps P1 and P2 are in a working state (or only a single pump works) and the oil ports of the multi-way valve are in an initial state, namely the reversing valve rods of the multi-way valve are in a middle position. At the moment, the flow discharged by the P1 and P2 pumps (or the flow discharged by the single pump during working) is transmitted to a A, B oil port (or one of A, B oil ports) through an internal oil circuit of the multi-way valve, hydraulic oil in a A, B (or one of A, B oil ports) cavity is transmitted to an accommodating cavity a or an accommodating cavity d at one end of the upper and lower valve rods through an oil duct b or e on the upper and lower valve rods, the hydraulic pressure in the accommodating cavity a or the accommodating cavity d pushes the upper and lower valve rods to move leftwards, an A, B accommodating cavity is communicated with N1 and N2 accommodating cavities, and the hydraulic oil in the N1 and N2 accommodating cavities is communicated with Dr through a throttling groove on a step shaft, so that the.
In this state, oil between the A, B cavity and the N1 and N2 cavities flows without throttling, that is, the pressure of the A, B cavity is equal to that of the N1 and N2 cavities; the N1 and N2 cavities are communicated with the Dr cavity by a throttling groove on a step shaft. Opening pressure signals of the upper valve rod and the lower valve rod are determined by upper spring force and lower spring force, opening pressure signals of the N1 cavities and the N2 cavities can adjust pre-tightening pressure of the upper spring and the lower spring through upper adjusting screws and lower adjusting screws, and flow of the N1 cavities and the N2 cavities to the oil return port Dr can be adjusted by adjusting the area of the throttling grooves in the upper valve rod and the lower valve rod. In short, the opening pressures of the upper valve rod and the lower valve rod are adjusted by adjusting the compression amount of the upper spring and the lower spring, and the flow rates from the N1 and N2 containing cavities to the oil return port Dr are adjusted by adjusting the areas of the throttling grooves on the upper valve rod and the lower valve rod.
Through the adjustment, the pressures of the N1 and N2 cavities and the pressures of the N1 and N2 cavities are fed back to the hydraulic pump to control the displacement of the hydraulic pump to be balanced with the unloading amount of the valve rod, and the energy conservation of the negative flow control hydraulic system at idle speed is realized through the balance of the N1, the N2 cavities, the N1 and the N2 cavities.
Description of the drawings: the positions of the upper valve rod and the lower valve rod are adjusted according to the pressure fed back to the cavity a and the cavity d from the A, B port, when the pressure of the cavity a and the cavity d rises, the upper valve rod and the lower valve rod move leftwards, the throttle area from the cavity N1 or the cavity N2 to Dr is reduced, the pressure of the cavity N1 or the cavity N2 rises, the cavity N1 or the cavity N2 is fed back to a displacement control port of the hydraulic pump, and the displacement of the pump is reduced until the required flow and pressure are in a balanced state. On the contrary, the displacement of the lift pump is in a balanced state after the flow and the pressure meet the requirements. And automatic adjustment of the hydraulic driving system is realized.
3. The working state is as follows: when any one or any one of the pumps P1 and P2 is in a working state and one or two valve rods of the corresponding multi-way valve are in a reversing state, the valve rods of the multi-way valve are reversed to cut off the oil passages of the corresponding A, B cavity and the oil passages P1 and P2. A. The pressure of the A, B cavity is reduced due to the cutting of the oil circuit of the cavity B or one of the oil circuits of the cavity B, the pressure of the cavity a and the cavity d is reduced, the upper valve rod and the lower valve rod move rightwards under the action of the upper spring force, the lower spring force and the hydraulic pressure, the area of the throttling groove on the step shaft is increased due to the fact that the upper valve rod and the lower valve rod move rightwards, the pressure of the corresponding cavity N1, the cavity N2 or one of the cavities is reduced, the pressure change of the cavity N1 and the cavity N2 is fed back to the corresponding pump, the displacement of the.
Description of the drawings: under the three working conditions, the XBP1 pilot control ports and the XBP2 pilot control ports are communicated with the oil tank through an external control mechanism.
4. A confluence state: when the flow rate required by the actuator corresponding to the P1 pump or the P2 pump is larger than the flow rate provided by the single pump, the two pumps need to be merged at the time. The working process is as follows:
under the working condition that the flow provided by a P1 pump cannot meet the flow required by an actuating mechanism and the flow provided by a P2 pump, under the working condition, an XBP2 pilot control port is not communicated with an oil tank through an external control mechanism, an XBP2 cavity becomes a closed cavity, an XBP2 cavity is communicated with a cavity d under the action of an elongated hole f, because an XBP2 cavity is the closed cavity, according to the static pressure principle, the pressure of the cavity d is equal to that of the XBP2 cavity, a lower valve rod moves rightwards under the action of a lower spring force until the lower valve rod is in an initial state, the cavity B is isolated from the cavity N2 under the action of the lower valve rod, at the moment, the N2 cavity is communicated with a Dr cavity, the flow area is at the maximum position, the pressure of an N2 cavity is at the minimum, the pressure of the N2 cavity is fed back to a P2 pump variable mechanism, the displacement of the P2 pump is at the maximum displacement position, the flow discharged by a P2.
The embodiment organically integrates the unloading valve, the confluence valve (cut-off valve) and the hydraulic drive control signal, realizes the perfect combination of the unloading valve, the confluence valve (cut-off valve) and the hydraulic drive control signal, simplifies the structural form of an oil way, and improves the response sensitivity of the system. The combination realizes simplification, reduces the number of parts, reduces the processing difficulty of the parts, reduces the manufacturing cost, reduces the volume of an unloading valve, a converging valve (a cut-off valve) and a hydraulic drive control signal, and reduces the duty ratio. The working characteristics of the negative flow control multi-way valve of the excavator under the idling working condition are fully utilized, the structure form and the function of the two-position two-way valve are utilized to replace an unloading valve and a converging valve (cut-off valve) structure, the structure and the function of the negative flow control multi-way valve and the hydraulic drive control signal are unified, and the purpose of slimming a hydraulic drive system of the hydraulic excavator is realized.

Claims (7)

1. A flow unloading valve comprises a valve body (1); the method is characterized in that: an upper valve core hole and a lower valve core hole which penetrate through the valve body (1) are formed in the valve body (1);
an upper left plug screw (10), an upper spring (7), an upper valve rod (8) and an upper right plug screw (9) are sequentially arranged in the upper valve core hole; the left end of the upper valve rod (8) is provided with an upper left spring cavity g, and the right end of the upper valve rod (8) is provided with an upper right containing cavity a; a first annular groove, a second annular groove and a third annular groove are sequentially formed in the upper valve rod (8) from left to right; an oil port XBP1 communicated with the upper left spring cavity g is formed in the valve body (1); an oil port A communicated with a first annular groove of the upper valve rod (8) is formed in the valve body (1), an oil port N1 communicated with a second annular groove of the upper valve rod (8) is formed in the valve body (1), and an oil port Dr communicated with a third annular groove of the upper valve rod (8) is formed in the valve body (1); an oil duct b communicated with the upper right cavity a is formed in the bottom of the first annular groove of the upper valve rod (8); a throttling groove is formed in the right side of the second annular groove of the upper valve rod (8); a long hole c communicated with the upper left spring cavity g and the upper right containing cavity a is formed in the upper valve rod (8); the left end of the long hole c is provided with a section of sliding hole with the diameter larger than that of the long hole c, and an upper floating damper is installed in the sliding hole in a sliding mode;
a lower left plug screw (4), a lower spring (12), a lower valve rod (14) and a lower right plug screw (15) are sequentially arranged in the lower valve core hole; the left end of the lower valve rod (14) is provided with a lower left spring cavity h, and the right end of the lower valve rod (14) is provided with a lower right containing cavity d; a first annular groove, a second annular groove and a third annular groove are sequentially formed in the lower valve rod (14) from left to right; an oil port XBP2 communicated with the lower left spring cavity h is formed in the valve body (1); an oil port B communicated with a first annular groove of the lower valve rod (14) is formed in the valve body (1), an oil port N2 communicated with a second annular groove of the lower valve rod (14) is formed in the valve body (1), and an oil port Dr in the valve body (1) is communicated to a third annular groove of the lower valve rod (14); an oil duct e communicated with the lower right cavity d is formed in the bottom of the first annular groove of the lower valve rod (14); a throttling groove is formed in the right side of the second annular groove of the lower valve rod (14); a long hole f communicated with the lower left spring cavity h and the lower right containing cavity d is formed in the lower valve rod (14); the left end of the long hole f is provided with a section of sliding hole with the diameter larger than that of the long hole f, and a lower floating damper is slidably arranged in the sliding hole;
the oil port A is communicated with a variable pump source P1 through a multiway valve, and the oil port B is communicated with a variable pump source P2 through the multiway valve; the oil port N1 is connected with an adjusting mechanism of a variable pump source P1, and the oil port N2 is connected with an adjusting mechanism of a variable pump source P2; the oil port Dr is connected with an oil tank; the oil port XBP1 and the oil port XBP2 are connected with a pilot oil source.
2. A flow unloader valve according to claim 1, wherein: an upper spring pad (5) is arranged on the inner end face of the upper left screw plug (10), and the left end of the upper spring (7) is mounted on the upper spring pad (5); the axis of the upper left screw plug (10) is provided with a threaded through hole, and an upper adjusting screw (17) is arranged in the threaded through hole of the upper left screw plug (10); the inner end of the upper adjusting screw (17) abuts against the left side of the upper spring pad (5), and the outer end of the upper adjusting screw (17) is provided with an upper locking nut (16).
3. A flow unloader valve according to claim 2, wherein: an upper sleeve (6) is covered outside the upper spring (7), and an oil through hole communicated with the oil port XBP1 is formed in the circumferential surface of the middle part of the upper sleeve (6); the periphery of the upper spring pad (5) is in sliding fit with the inner wall of the upper sleeve (6), the left end of the upper sleeve (6) is abutted against the inner side face of the upper left screw plug (10), and the right end of the upper sleeve (6) is opposite to the upper valve rod (8) and a gap is reserved between the right end of the upper sleeve (6) and the upper valve rod.
4. A flow unloader valve according to claim 1, wherein: and a fourth annular groove is formed in the right side of the third annular groove in the upper valve rod (8), and an oil hole communicated with the oil duct b is formed in the bottom of the fourth annular groove in the upper valve rod (8).
5. A flow unloader valve according to claim 1, wherein: a lower spring pad (11) is arranged on the inner end face of the lower left screw plug (4), and the left end of the lower spring (12) is installed on the lower spring pad (11); the axis of the lower left screw plug (4) is provided with a threaded through hole, and a lower adjusting screw (3) is arranged in the threaded through hole of the lower left screw plug (4); the inner end of the lower adjusting screw (3) abuts against the left side of the lower spring pad (11), and the outer end of the lower adjusting screw (3) is provided with an upper locking nut (2).
6. A flow unloader valve according to claim 5, wherein: the lower spring (12) is covered by a lower sleeve (13), and the circumferential surface of the middle part of the lower sleeve (13) is provided with an oil through hole communicated with an oil port XBP 2; the periphery of the lower spring pad (11) is in sliding fit with the inner wall of the lower sleeve (13), the left end of the lower sleeve (13) is abutted against the inner side face of the lower left screw plug (4), and the right end of the lower sleeve (13) is opposite to the lower valve rod (14) and a gap is reserved between the right end of the lower sleeve (13) and the lower valve rod (14).
7. A flow unloader valve according to claim 1, wherein: and a fourth annular groove is formed in the right side of the third annular groove in the lower valve rod (14), and an oil hole communicated with the oil duct e is formed in the bottom of the fourth annular groove in the lower valve rod (14).
CN201910778815.5A 2019-08-22 2019-08-22 Flow unloading valve and hydraulic driving system of hydraulic excavator Active CN110454457B (en)

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CN115405576A (en) * 2022-10-31 2022-11-29 索特传动设备有限公司 Variable differential pressure valve, load sensitive hydraulic system and engineering machinery

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JPH07217765A (en) * 1994-01-31 1995-08-15 Toyooki Kogyo Co Ltd Electromagnetically operated pressure reducing valve
CN101846111A (en) * 2010-06-10 2010-09-29 江苏鼎晟液压有限公司 Pilot proportional multi-path reversing valve
CN103603971A (en) * 2013-12-04 2014-02-26 湘潭大学 Multi-way valve with single oil duct and double valve elements in parallel connection and used for high-power excavator
JP2015072055A (en) * 2013-10-04 2015-04-16 川崎重工業株式会社 Control valve
CN204704187U (en) * 2015-06-29 2015-10-14 象山盛韵汽配科技有限公司 Overload unloading valve
CN205371728U (en) * 2016-02-02 2016-07-06 南京航海仪器二厂有限公司 Quick off -load relief valve
CN105909588A (en) * 2015-02-24 2016-08-31 川崎重工业株式会社 Unloading valve and hydraulic drive system for hydraulic excavator

Patent Citations (7)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
JPH07217765A (en) * 1994-01-31 1995-08-15 Toyooki Kogyo Co Ltd Electromagnetically operated pressure reducing valve
CN101846111A (en) * 2010-06-10 2010-09-29 江苏鼎晟液压有限公司 Pilot proportional multi-path reversing valve
JP2015072055A (en) * 2013-10-04 2015-04-16 川崎重工業株式会社 Control valve
CN103603971A (en) * 2013-12-04 2014-02-26 湘潭大学 Multi-way valve with single oil duct and double valve elements in parallel connection and used for high-power excavator
CN105909588A (en) * 2015-02-24 2016-08-31 川崎重工业株式会社 Unloading valve and hydraulic drive system for hydraulic excavator
CN204704187U (en) * 2015-06-29 2015-10-14 象山盛韵汽配科技有限公司 Overload unloading valve
CN205371728U (en) * 2016-02-02 2016-07-06 南京航海仪器二厂有限公司 Quick off -load relief valve

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