CN110735823A - Hydraulic holding device, hydraulic system, and excavator - Google Patents

Hydraulic holding device, hydraulic system, and excavator Download PDF

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Publication number
CN110735823A
CN110735823A CN201911010218.4A CN201911010218A CN110735823A CN 110735823 A CN110735823 A CN 110735823A CN 201911010218 A CN201911010218 A CN 201911010218A CN 110735823 A CN110735823 A CN 110735823A
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China
Prior art keywords
valve
hydraulic
buffer
holding device
reversing
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CN201911010218.4A
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Chinese (zh)
Inventor
郑乾坤
应伟健
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Sany Heavy Machinery Ltd
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Sany Heavy Machinery Ltd
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Priority to CN201911010218.4A priority Critical patent/CN110735823A/en
Publication of CN110735823A publication Critical patent/CN110735823A/en
Pending legal-status Critical Current

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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
    • F15B13/00—Details of servomotor systems ; Valves for servomotor systems
    • F15B13/01—Locking-valves or other detent i.e. load-holding devices
    • 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
    • E02F9/2264—Arrangements or adaptations of elements for hydraulic drives
    • E02F9/2267—Valves or distributors
    • 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
    • E02F9/2278—Hydraulic circuits
    • E02F9/2285—Pilot-operated systems
    • 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
    • F15B13/04—Fluid distribution or supply devices characterised by their adaptation to the control of servomotors for use with a single servomotor

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

Abstract

The invention provides hydraulic holding devices, a hydraulic system and an excavator, and relates to the technical field of engineering machinery, wherein each hydraulic holding device comprises a safety valve and a buffer pipeline, an inlet of the safety valve is communicated with a working cavity of an external telescopic driving piece, the safety valve can be opened when the medium pressure in the working cavity of the external telescopic driving piece exceeds a set pressure, an outlet of the safety valve is communicated with an outlet of the buffer pipeline, a throttling part is arranged on the buffer pipeline and used for reducing the flow rate of a medium passing through the throttling part, and the hydraulic system comprises an oil source, an oil cylinder and the hydraulic holding device, and the hydraulic holding device is communicated between the oil cylinder and the oil source.

Description

Hydraulic holding device, hydraulic system, and excavator
Technical Field
The invention relates to the technical field of engineering machinery, in particular to an hydraulic holding device, a hydraulic system and an excavator.
Background
The lifting and lowering of the boom of the excavator are realized by the expansion and contraction of a boom cylinder hinged with the boom. The movable arm oil cylinder comprises a rodless cavity and a rod cavity provided with an oil cylinder output shaft, and the rod cavity and the rodless cavity are respectively communicated with the oil tank through pipelines. The output shaft of the oil cylinder can move by changing the volume of oil in the rod cavity and the rodless cavity, and then the boom oil cylinder is made to stretch and retract so as to drive the boom of the excavator to lift or descend.
In order to prevent the hydraulic oil in the rodless chamber of the boom cylinder from being pressed back into the tank by the pressure of the boom when the boom is in a lifted state, i.e., to prevent the arm drop of the excavator, a hydraulic maintaining device is provided between the boom cylinder and the tank of the existing excavator, as shown in fig. 1, the hydraulic maintaining device includes a shuttle valve 1 ' and a direction control valve 2 ', the shuttle valve 1 ' is provided in a conduit between the rodless chamber of the boom cylinder 3 ' and the tank 4 ', the shuttle valve 1 ' is communicated with the direction control valve 2 ', the direction control valve 2 ' is communicated with the tank 4 ', conduits are further communicated with the side of the direction control valve 2 ', the conduits can be filled with or drained of the hydraulic oil, when the boom is lifted, the hydraulic maintaining device does not operate, the tank 4 ' can supply oil into the rodless chamber, thereby extending the boom cylinder 3 ', the boom is lifted, when the supply of the hydraulic oil into the rodless chamber is stopped, the shuttle valve 1 ' disconnects the conduit between the rodless chamber and the direction control valve 2 ' does not operate, the direction control valve 2 ' is in a closed state, the direction control valve 2 ' can return to the direction control valve 4 ' to the tank 4 ' to control the direction of the boom cylinder, and the direction control valve 2 ' to be lowered when the direction control valve 2 ' is not operated, the direction of the boom cylinder 2 ', the direction control valve 2 ' is lowered, the direction control valve 2 ' is not to shorten.
In order to prevent the pressure in the pipeline between the rodless cavity and the hydraulic holding device and the oil tank 4 ' from being too high, the hydraulic holding device also comprises an overflow valve 5 ', wherein the overflow valve 5 ' is used for ensuring that the pressure in the rodless cavity and the pressure in the pipeline do not exceed a certain set pressure, as shown in figure 1, a pipeline between the rodless cavity and the shuttle valve 1 ' is communicated with an inlet of the overflow valve 5 ', an outlet of the overflow valve 5 ' is communicated with the oil tank 4 ', when abnormal high pressure occurs in the pipeline and exceeds the opening pressure of the overflow valve 5 ', the overflow valve 5 ' is opened, and part of hydraulic oil in the rodless cavity can overflow back to the oil tank 4 ' through the overflow valve 5 ', so that the pressure in the pipeline is reduced.
When the movable arm is emergently braked in the descending process, in order to prevent the hydraulic oil in the rodless cavity from continuously flowing out, the pressure in a pipeline between the rodless cavity, the hydraulic holding device and the oil tank 4 'is increased, so that the oil pressure in the rodless cavity is increased and is higher than the opening pressure of the overflow valve 5', at the moment, the overflow valve 5 'is opened, the oil pressure in the rodless cavity is instantly restored to the certain set pressure, meanwhile, the oil pressure in the rod cavity and the rodless cavity of the movable arm oil cylinder 3' is balanced, and the emergency brake immediately takes effect.
Disclosure of Invention
The invention aims to provide hydraulic holding devices, a hydraulic system and an excavator, which are used for relieving the technical problems that emergency braking is immediately effective when a movable arm of the excavator descends, but the movable arm still tends to descend, parts such as a chassis, a cab and the like of the excavator generate upward impact force on the movable arm, the movable arm generates large overturning moment on the parts such as the chassis, the cab and the like of the excavator under the impact force of the parts such as the chassis, the cab and the like of the excavator and the inertia force of the movable arm, and the side of the excavator chassis far away from the movable arm is prone to be tilted upwards and turned over.
The hydraulic holding device provided by the invention comprises a safety valve and a buffer pipeline;
the inlet of the safety valve is communicated with the working cavity of the external telescopic driving piece, and the safety valve can be opened when the medium pressure in the working cavity of the external telescopic driving piece exceeds a set pressure so as to enable the medium in the working cavity of the external telescopic driving piece to flow out;
the outlet of the safety valve is communicated with the outlet of the buffer pipeline, and a medium can be introduced into the inlet of the buffer pipeline;
the buffer pipeline is provided with a throttling part, and the throttling part is used for reducing the flow velocity of the medium passing through the throttling part in the buffer pipeline.
, the hydraulic pressure maintaining device further comprises a selection valve and a reversing valve, wherein the selection valve comprises inlets and two outlets, and the reversing valve comprises two inlets and outlets;
outlets of the selector valve are communicated with the inlet of the safety valve, and the other outlets of the selector valve are communicated with inlets of the reversing valve;
the other inlets of the reversing valve are reversing inlets, and a medium can be introduced into the reversing inlets of the reversing valve to drive the reversing valve to reverse.
, the inlet of the buffer pipe is connected to the reversing inlet of the reversing valve.
, the hydraulic retention device further includes a direction conduit having an outlet in communication with the direction inlet of the direction valve.
, a media source in communication with the external telescoping drive member is in communication with the outlet of the reversing valve.
, a media source in communication with the external telescopic drive member is in communication with the outlet of the safety valve.
Further , the restriction is a depression disposed on the buffer tube, the depression being depressed toward an axis of the buffer tube.
, the throttle part is a baffle vertically arranged on the inner wall of the buffer pipeline, the baffle is provided with a perforation, and the area of the perforation is smaller than the area of the radial section of the buffer pipeline.
The hydraulic system provided by the invention comprises an oil source, an oil cylinder and the hydraulic holding device of any item in the technical scheme, wherein the hydraulic holding device is communicated between the oil cylinder and the oil source.
The excavator provided by the invention comprises the hydraulic system.
The hydraulic holding device, the hydraulic system and the excavator provided by the invention can produce the following beneficial effects:
the invention provides a hydraulic holding device, which comprises a safety valve and a buffer pipeline, wherein when a medium in a working cavity of an external telescopic driving piece communicated with the safety valve flows out, the external telescopic driving piece is shortened, a part connected with the external telescopic driving piece can be a movable arm of an excavator, when the movable arm descends, the medium in the working cavity of the external telescopic driving piece communicated with the safety valve flows out, the medium pressure in the working cavity is reduced, the safety valve does not work, at the moment, the medium can be introduced to the side of an outlet of the safety valve, which is far away from an inlet, through the buffer pipeline, when the movable arm is braked emergently, the medium is not supplied to the buffer pipeline and the outlet of the safety valve, and part of the medium is withdrawn from the buffer pipeline.
When the movable arm is braked suddenly, the medium in the working cavity of the external telescopic driving piece, which is communicated with the safety valve, does not flow out continuously any more, the pressure of the medium in the working cavity of the external telescopic driving piece, which is communicated with the safety valve, is increased instantaneously and exceeds the reduced opening pressure of the safety valve, and at the moment, the safety valve is opened and works.
In addition, when the opening pressure of the safety valve is recovered to the original set opening pressure value, the safety valve can continue to work normally without influencing the use effect of the safety valve.
The hydraulic system provided by the invention comprises the hydraulic holding device, and the excavator provided by the invention comprises the hydraulic system, so that the hydraulic system and the excavator provided by the invention both comprise the hydraulic holding device, and the hydraulic system and the excavator have the same beneficial effects as the hydraulic holding device.
Drawings
In order to more clearly illustrate the embodiments of the present invention or the technical solutions in the prior art, the drawings used in the description of the embodiments or the prior art will be briefly described below, and it is obvious that the drawings in the following description are embodiments of the present invention, and other drawings can be obtained by those skilled in the art without creative efforts.
FIG. 1 is a schematic diagram of the operation of a prior art hydraulic retention device;
FIG. 2 is a schematic diagram of the operation of a hydraulic retention device provided in accordance with an embodiment of the present invention;
FIG. 3 is a schematic view of the buffer pipe and the throttle portion of FIG. 2;
FIG. 4 is a schematic view of another structure of the throttle portion provided in the embodiment of the present invention;
fig. 5 is a graph showing a change in opening pressure value of the relief valve according to embodiment of the present invention.
Icon: 1' -a shuttle valve; a 2' -directional control valve; 3' -a boom cylinder; 4' -a fuel tank; 5' -an overflow valve; 1-safety valve; 2-a buffer pipe; 20-a throttle; 3-an external telescopic driving member; 30-rodless cavities; 31-a rod cavity; 4-a selector valve; 5-a reversing valve; 6-a reversing pipe; 7-a source of media.
Detailed Description
The technical solution of this embodiment will be described clearly and completely with reference to the following embodiments, and it is obvious that the described embodiments are some, but not all, embodiments .
Example :
as shown in fig. 2, the hydraulic pressure holding device provided in this embodiment includes a relief valve 1 and a buffer pipe 2, an inlet of the relief valve 1 communicates with the working chamber of the external telescopic driver 3, and the relief valve 1 can be opened when the pressure of the medium in the working chamber of the external telescopic driver 3 exceeds a set pressure, so that the medium in the working chamber of the external telescopic driver 3 can flow out. The outlet of the safety valve 1 is communicated with the outlet of the buffer pipeline 2, and the inlet of the buffer pipeline 2 can be filled with a medium. As shown in fig. 3-4, the buffer pipe 2 is provided with a throttling portion 20, and the throttling portion 20 is used for reducing the flow rate of the medium passing through the throttling portion 20 in the buffer pipe 2.
In practical application, the relief valve 1 may be an overflow valve in an existing hydraulic holding device; the external telescopic driving part 3 can be a telescopic driving part such as an oil cylinder or an air cylinder; the part connected with the external telescopic driving piece 3 can be a movable arm on an excavator or a telescopic arm on an automobile crane and the like. In addition, the medium may be hydraulic oil or gas, etc. corresponding to the external telescopic driving member 3.
In the present embodiment, the working principle of the hydraulic holding device is described below by taking the external telescopic driving unit 3 as a cylinder, the medium as hydraulic oil, and the member connected to the external telescopic driving unit 3 as a boom of the excavator as an example:
the oil cylinder comprises a rodless cavity 30 and a rod cavity 31, a piston rod is arranged in the rod cavity 31 of the oil cylinder, and the piston rod is connected with the movable arm. When the hydraulic oil in the working chamber of the oil cylinder (i.e. the rodless chamber 30 of the oil cylinder) communicated with the safety valve 1 flows out, the oil cylinder is shortened, and the movable arm of the excavator can be driven to descend. When the movable arm descends, hydraulic oil in a working cavity of the oil cylinder, which is communicated with the safety valve 1, flows out, the oil pressure in the working cavity is reduced, the safety valve 1 does not work, and at the moment, the hydraulic oil can be introduced to the outlet side of the safety valve 1 through the buffer pipeline 2. When the boom is suddenly braked, the hydraulic oil is no longer supplied to the buffer pipe 2 and the outlet of the relief valve 1, and the part of the hydraulic oil is withdrawn from the buffer pipe 2. Because the throttling part 20 is arranged on the buffer pipeline 2, the hydraulic oil on the buffer pipeline 2 and the outlet side of the safety valve 1 can slowly withdraw from the buffer pipeline 2, and at the moment, the oil pressure exists at the outlet of the safety valve 1, and the opening pressure of the safety valve 1 can be reduced. As the hydraulic oil at the buffer pipe 2 and the outlet side of the relief valve 1 gradually exits from the buffer pipe 2, the opening pressure of the relief valve 1 gradually increases to its original set opening pressure value.
The real-time opening pressure value P of the safety valve 1 is obtained in the process that the hydraulic oil in the buffer pipeline 2 is gradually withdrawn1Can be calculated according to the following equation (1):
P1＝P0-Pt(1)
wherein t is the time required for the hydraulic oil in the buffer pipeline 2 to gradually exit; p0The opening pressure value originally set for the safety valve 1, which is a known fixed value; ptIs the oil pressure present at the outlet of the relief valve 1, it is of variable quantity and it is gradually reduced to zero by a fixed value of during time t.
As shown in fig. 5, during the boom-down process, the hydraulic oil exists in the buffer pipe 2 and the outlet side of the relief valve 1, and at this time PtIs present and is less than P0 constant value, opening pressure P at relief valve 11Is less than P0. When the movable arm is emergently braked in the descending process, the hydraulic oil in the buffer pipeline 2 is gradually withdrawn, PtThe constant value of is reduced to zero in time t, and the opening pressure at the safety valve 1 is reducedForce P1Gradually increase until it equals P0。
When the movable arm is emergently braked, the hydraulic oil in the working cavity of the oil cylinder communicated with the safety valve 1 does not continuously flow out, the pressure of the hydraulic oil in the working cavity is instantly increased and exceeds the reduced opening pressure of the safety valve 1, and at the moment, the safety valve 1 is opened and works. Due to the opening pressure P of the safety valve 11Is lowered and thus maintained at P compared to the prior art relief valve 10The hydraulic oil in the working chamber of the oil cylinder in the embodiment, which is communicated with the safety valve 1, flows out in advance, so that the oil pressure in the working chamber of the oil cylinder, which is communicated with the safety valve 1, is lower than the pressure value initially set in the working chamber. Following the opening pressure P of the safety valve 11Gradually increases to P0The oil pressure in the working chamber of the oil cylinder, which communicates with the safety valve 1, is also gradually increased to the initially set pressure value therein, and is not instantaneously restored to the initially set pressure value therein.
Therefore, in the process of descending the movable arm, compared with the prior art, the oil pressure in the working cavity of the oil cylinder communicated with the safety valve 1 is firstly low and then high, the oil pressure in the rodless cavity 30 of the oil cylinder and the oil pressure in the rod cavity 31 cannot be instantly balanced to meet the braking requirement, the braking effect can be prevented from being immediately effective, the braking process can be prevented from being buffered, the upward impact force on the movable arm caused by parts such as a chassis and a cab of the excavator can be further reduced, the movable arm is prevented from generating larger overturning moment on the parts such as the chassis and the cab of the excavator, and the side of the chassis of the excavator far away from the movable arm is further prevented from being upwards overturned to turn on the side.
In addition, when the opening pressure of the safety valve 1 is restored to the original set opening pressure value, the safety valve 1 can continue to work normally without affecting the use effect.
The time t can be adjusted by the size of the throttle 20 in the buffer pipe 2. It should be noted that the time t should not be too long so as not to affect the braking effect.
It can be seen that the hydraulic holding device provided by the embodiment alleviates the technical problem that in the prior art, when the boom of the excavator descends, emergency braking is immediately effective, but the boom still tends to descend, meanwhile, parts such as the chassis and the cab of the excavator generate upward impact force on the boom, and under the impact force of the chassis and the cab of the excavator and the inertia force of the boom, the boom generates a large overturning moment on the chassis and the cab of the excavator, so that the side of the chassis of the excavator far from the boom is prone to tilt upwards and turn over.
As shown in FIG. 2, the hydraulic pressure maintaining device provided by the embodiment further comprises a selector valve 4 and a reversing valve 5, wherein the selector valve 4 comprises inlets and two outlets, the reversing valve 5 comprises two inlets and outlets, a medium for driving the external telescopic driving piece 3 to stretch and contract can be introduced at the inlet of the selector valve 4, outlets of the selector valve 4 are communicated with the inlet of the safety valve 1, the other outlets of the selector valve 4 are communicated with inlets of the reversing valve 5, the other inlets of the reversing valve 5 are reversing inlets, and the medium can be introduced at the reversing inlet of the reversing valve 5 to drive the reversing valve 5 to reverse.
When the boom is lifted, the hydraulic holding device does not operate, and at this time, hydraulic oil can be supplied into the rodless chamber 30 of the cylinder, so that the cylinder is extended and the boom is lifted. When the movable arm needs to be stopped, oil supply to the rodless cavity 30 needs to be stopped, the selector valve 4 is in a working state at the moment, a pipeline between the rodless cavity 30 and an oil source can be blocked, meanwhile, the reversing valve 5 does not work, hydraulic oil cannot return to the oil source from the rodless cavity 30, and the movable arm can be kept stationary. When the boom descends, it is not only necessary to supply oil to the rod chamber 31, but also to communicate the selector valve 4 with the direction valve 5 and to change the direction of the direction valve 5. After the reversing valve 5 is reversed, the hydraulic oil in the rodless cavity 30 can sequentially pass through the selector valve 4 and the reversing valve 5 and then flow back to the oil source, at the moment, the boom oil cylinder is shortened, and the boom descends.
The selector valve 4 may be a shuttle valve in an existing hydraulic holding device, and the direction change valve 5 may be a direction control valve in the existing hydraulic holding device. The selector valve 4 and the reversing valve 5 are used in cooperation to realize three processes of lifting, stopping and descending of the boom, and since the application of the shuttle valve and the directional control valve in the existing hydraulic holding device is common knowledge, the specific working processes of the selector valve 4 and the reversing valve 5 are not described in detail in this embodiment.
As shown in fig. 2, the inlet of the buffer pipe 2 communicates with the reversing inlet of the reversing valve 5.
The reversing valve 5 needs to be reversed when the movable arm descends, oil can be supplied to the reversing inlet at the moment, the inlet of the buffer pipeline 2 is communicated with the reversing inlet of the reversing valve 5, so that oil can be fed into the buffer pipeline 2 while the reversing valve 5 is reversed by supplying oil to the reversing valve 5, and the hydraulic oil for driving the reversing valve 5 to reverse does not need to be too high in oil pressure, so that the hydraulic oil in the buffer pipeline 2 cannot flow into the rodless cavity 30 through the buffer pipeline 2 after passing through the safety valve 1, the descending process of the oil cylinder cannot be influenced, and fixed oil pressure can exist on the side of the outlet of the safety valve 1, which is far away from the inlet, by the hydraulic oil entering the buffer pipeline 2.
In addition, when the boom is suddenly braked during the lowering process, the direction change valve 5 needs to be changed again, and at this time, the hydraulic oil in the direction change valve 5 needs to be removed. At the same time when the hydraulic oil in the reversing valve 5 is withdrawn, the hydraulic oil in the buffer pipeline 2 is also withdrawn, and then the effect of buffer braking can be achieved by using the throttling part 20 on the buffer pipeline 2.
The inlet of the buffer pipeline 2 is communicated with the reversing inlet of the reversing valve 5, so that the reversing valve 5 can supply oil to the buffer pipeline 2 while reversing, an oil source is not required to be additionally arranged for the buffer pipeline 2, the oil source is not required to be additionally supplied for the buffer pipeline 2, and the hydraulic oil in the buffer pipeline 2 can be withdrawn when the reversing valve 5 reverses again. Therefore, the inlet of the buffer pipeline 2 is communicated with the reversing inlet of the reversing valve 5, the reversing valve 5 can work normally, and meanwhile, the reversing process of the reversing valve 5 is utilized to control the buffer pipeline 2 to work normally, so that the structure of the hydraulic holding device can be simplified, and the working efficiency of the hydraulic holding device can be improved.
As shown in fig. 2, the hydraulic pressure holding apparatus provided in the present embodiment further includes a direction change pipe 6, and an outlet of the direction change pipe 6 communicates with a direction change inlet of the direction change valve 5.
The reversing pipeline 6 is convenient for sending hydraulic oil in the oil source into the reversing valve 5 and the buffer pipeline 2, and the oil source does not need to be additionally arranged for the reversing valve 5 and the buffer pipeline 2, so that the structure of the hydraulic holding device can be simplified in step , and the working efficiency of the hydraulic holding device can be improved.
As shown in fig. 2, a medium source 7, which communicates with the external telescopic drive 3, communicates with the outlet of the reversing valve 5.
The medium source 7 communicated with the external telescopic driving piece 3 is communicated with the outlet of the reversing valve 5, so that hydraulic oil flowing out of the reversing valve 5 can return to the medium source 7 (the medium source 7 can be an oil source), the hydraulic oil flowing out of the reversing valve 5 can be recycled, the waste of media is avoided, and the effect of saving energy is achieved.
As shown in fig. 2, a medium source 7, which communicates with the external telescopic drive 3, communicates with the outlet of the safety valve 1.
The medium source 7 that communicates with outside flexible driving piece 3, and the export intercommunication of relief valve 1 can make the hydraulic oil that flows out in the relief valve 1 get back to in the medium source 7, and then can recycle the hydraulic oil that flows out in the relief valve 1, avoid extravagant medium, reach the effect of energy can be saved.
As shown in fig. 3, the throttle portion 20 may be a recessed portion provided on the buffer pipe 2, the recessed portion being recessed toward the axis of the buffer pipe 2.
When the throttling part 20 is a concave part, the area of the radial section of the throttling part 20 of the buffer pipeline 2 can be smaller than that of the radial section of the rest part of the buffer pipeline 2, so that the hydraulic oil can play a role of blocking when exiting from the buffer pipeline 2, and the hydraulic oil in the buffer pipeline 2 is prevented from exiting instantly.
As shown in fig. 4, the throttling portion 20 may also be a baffle plate vertically disposed on the inner wall of the buffer pipe 2, and the baffle plate is provided with a through hole, and the area of the through hole is smaller than the area of the radial cross section of the buffer pipe 2.
When the throttling part 20 is a baffle provided with a through hole, the area of the radial section of the throttling part 20 of the buffer pipeline 2 can be smaller than that of the radial section of the rest part of the buffer pipeline 2, and the throttling part can also play a role in blocking when hydraulic oil exits from the buffer pipeline 2, so that the hydraulic oil in the buffer pipeline 2 is prevented from exiting instantly.
Example two:
the hydraulic system of this embodiment includes an oil source, a cylinder, and the hydraulic retaining apparatus of embodiment , the hydraulic retaining apparatus being in communication between the cylinder and the oil source.
Because the hydraulic system provided by the embodiment comprises the hydraulic holding device in the embodiment , the hydraulic system provided by the embodiment can solve the same technical problems as the hydraulic holding device in the embodiment , and achieves the same technical effects.
Example three:
the excavator provided by the embodiment includes the hydraulic system in the second embodiment, and the excavator provided by the embodiment controls the expansion and contraction of the oil cylinder by using the hydraulic system in the second embodiment, so as to control the lifting and descending processes of the boom.
Since the excavator provided by this embodiment includes the hydraulic system of the second embodiment and the hydraulic system of the second embodiment includes the hydraulic holding device of the , the hydraulic system provided by this embodiment can solve the same technical problems and achieve the same technical effects as the hydraulic system of the second embodiment and the hydraulic holding device of the embodiment .
Finally, it should be noted that: the above embodiments are only used for illustrating the technical solution of the present embodiment, and not for limiting the same; although the present embodiment has been described in detail with reference to the foregoing embodiments, it should 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 these modifications or 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 embodiment.

Claims (10)

  1. Hydraulic holding device of the kind , characterized in that, the hydraulic holding device includes a relief valve (1) and a buffer pipe (2);
    the inlet of the safety valve (1) is communicated with the working cavity of the external telescopic driving part (3), and the safety valve (1) can be opened when the medium pressure in the working cavity of the external telescopic driving part (3) exceeds a set pressure so as to enable the medium in the working cavity of the external telescopic driving part (3) to flow out;
    the outlet of the safety valve (1) is communicated with the outlet of the buffer pipeline (2), and a medium can be introduced into the inlet of the buffer pipeline (2);
    the buffer pipeline (2) is provided with a throttling part (10), and the throttling part (10) is used for reducing the flow speed of a medium passing through the throttling part (10) in the buffer pipeline (2).
  2. 2. The hydraulic holding device according to claim 1, further comprising a selector valve (4) and a direction valve (5), wherein the selector valve (4) comprises inlets and two outlets, and the direction valve (5) comprises two inlets and outlets;
    outlets of the selector valve (4) are communicated with the inlet of the safety valve (1), and the other outlets of the selector valve (4) are communicated with inlets of the reversing valve (5);
    the other inlets of the reversing valve (5) are reversing inlets, and a medium can be introduced into the reversing inlets of the reversing valve (5) to drive the reversing valve (5) to reverse.
  3. 3. Hydraulic holding device according to claim 2, characterised in that the inlet of the buffer conduit (2) communicates with a reversing inlet of the reversing valve (5).
  4. 4. The hydraulic holding device according to claim 3, further comprising a direction-changing conduit (6), an outlet of the direction-changing conduit (6) communicating with a direction-changing inlet of the direction-changing valve (5).
  5. 5. Hydraulic holding device according to claim 2, characterised in that a medium source (7) communicating with the external telescopic drive (3) communicates with the outlet of the reversing valve (5).
  6. 6. Hydraulic holding device according to claim 1, characterised in that a medium source (7) communicating with the external telescopic drive (3) communicates with an outlet of the safety valve (1).
  7. 7. The hydraulic retention device according to , characterized in that the restriction (10) is a recess provided on the buffer conduit (2), which recess is recessed towards the axis of the buffer conduit (2).
  8. 8. The hydraulic retention device according to , characterized in that the restriction (10) is a baffle plate arranged perpendicularly to the inner wall of the buffer tube (2) and provided with perforations having an area smaller than the area of the radial cross-section of the buffer tube (2).
  9. A hydraulic system of comprising an oil source, a cylinder, and the hydraulic retention device of any of claims 1-8, the hydraulic retention device being in communication between the cylinder and the oil source.
  10. 10, excavator, characterized in that the excavator comprises the hydraulic system of claim 9.
CN201911010218.4A 2019-10-23 2019-10-23 Hydraulic holding device, hydraulic system, and excavator Pending CN110735823A (en)

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CN201911010218.4A CN110735823A (en) 2019-10-23 2019-10-23 Hydraulic holding device, hydraulic system, and excavator

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CN102889273A (en) * 2012-10-18 2013-01-23 浙江大学 Electro-hydraulic system for recycling and releasing potential energy of engineering machinery

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* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
CN102889273A (en) * 2012-10-18 2013-01-23 浙江大学 Electro-hydraulic system for recycling and releasing potential energy of engineering machinery

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