CN115899004A - Hydraulic dumping control system of dump truck and control method thereof - Google Patents
Hydraulic dumping control system of dump truck and control method thereof Download PDFInfo
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- CN115899004A CN115899004A CN202310023405.6A CN202310023405A CN115899004A CN 115899004 A CN115899004 A CN 115899004A CN 202310023405 A CN202310023405 A CN 202310023405A CN 115899004 A CN115899004 A CN 115899004A
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Abstract
The invention discloses a hydraulic dumping control system of a dump truck and a control method thereof, and relates to the technical field of hydraulic control of engineering machinery. A displacement sensor is arranged on a frame of the dump truck, a hydraulic dumping control system comprises a dump cylinder, a first hydraulic control reversing valve, a gear pump, a hydraulic control pilot handle and an electromagnetic reversing valve, the gear pump provides pilot oil for a control valve of the hydraulic control pilot handle, the control valve is connected with the dump cylinder through the first hydraulic control reversing valve, a first working oil port of the first hydraulic control reversing valve is communicated with a rodless cavity of the dump cylinder, and a second working oil port of the first hydraulic control reversing valve is communicated with a rod cavity of the dump cylinder; the control end of the electromagnetic directional valve is in signal connection with the displacement sensor, the oil inlet of the electromagnetic directional valve can be communicated with the oil outlet of the gear pump, the oil outlet of the electromagnetic directional valve is communicated with the first hydraulic control end of the first hydraulic control directional valve, and the first working oil port and the second working oil port of the first hydraulic control directional valve can be communicated with the oil return port of the first hydraulic control directional valve.
Description
Technical Field
The invention relates to the technical field of hydraulic control of engineering machinery, in particular to a hydraulic dumping control system of a dump truck and a control method thereof.
Background
The hinged dumper is an earth and stone transportation machine with strong universality and has high adaptability to climate and various terrains. In view of the working environment of the articulated dump truck in severe weather and complex terrains, reliability is a basic requirement for measuring the performance of the articulated dump truck.
As shown in fig. 1, the hydraulic dumping control system of the articulated dump truck operated by the hydraulic pilot handle in the prior art includes a hydraulic oil cylinder 1 ', a hydraulic control multi-way valve 2 ', a hydraulic control valve 3 ' of the hydraulic pilot handle, a pilot pump 4 ' and a pressure pump 5 '. The working principle is as follows: the pilot pump 4' provides a constant pilot pressure, ensuring timeliness of the operation of the pilot-operated handle. The pilot-controlled pilot handle is divided into four gear positions, namely an ascending gear, a stopping gear, a descending gear and a floating gear. When the pilot control pilot handle is not operated, no pilot pressure oil is used for driving, the valve core of the pilot control multi-way valve 2' does not move, and the valve core is in a stop gear at the moment; when the operation of pilot control pilot handle to rising fender position, decline fender position and the fender position of floating, the pivot angle and the pressure of pilot control pilot handle are directly proportional, and the case of pilot control multi-way valve 2 'moves different positions according to corresponding pilot pressure, the case that promotes pilot control multi-way valve 2', exports flow and pressure, also namely according to the different positions of pilot control pilot handle, realizes the rising of packing box, stops, descends, the function demand that floats. However, if the driver is unfamiliar with the operating rules or carelessness, the following situation may occur: (1) after the packing box dumps and finishes, descend to the in-process that is close to the frame, if not operating in time and keeping off the position that floats, can assault frame output, impact load can reduce frame life, and it is poor to drive the impression moreover. (2) If not operating the fender position that floats in the loading and the in-process of traveling, the additional impact load that jolt caused on road surface when the impact of goods and the traveling produced can produce the impact to hydraulic cylinder 1 ' when loading, and instantaneous pressure is great in messenger hydraulic cylinder 1 ', influences the life of hydraulic cylinder 1 '.
Disclosure of Invention
The invention aims to provide a hydraulic dumping control system of a dump truck and a control method thereof, which can avoid the influence on the service life of the dump truck and the driving experience of a driver caused by misoperation.
In order to achieve the purpose, the invention adopts the following technical scheme:
the hydraulic dumping control system of the dump truck comprises a cargo box and a frame, the hydraulic dumping control system comprises a dumping oil cylinder, a first hydraulic control reversing valve, a gear pump and a hydraulic control pilot handle, the gear pump provides pilot oil for a control valve of the hydraulic control pilot handle, the control valve is connected with the dumping oil cylinder through the first hydraulic control reversing valve, a first working oil port of the first hydraulic control reversing valve is communicated with a rodless cavity of the dumping oil cylinder, and a second working oil port of the first hydraulic control reversing valve is communicated with a rod cavity of the dumping oil cylinder; wherein,
a displacement sensor is arranged on the frame and used for detecting the distance between the container and the frame;
the hydraulic dumping control system further comprises an automatic floating valve, the automatic floating valve comprises an electromagnetic directional valve, the control end of the electromagnetic directional valve is in signal connection with the displacement sensor, the oil inlet of the electromagnetic directional valve can be communicated with the oil outlet of the gear pump, the oil outlet of the electromagnetic directional valve is communicated with the first hydraulic control end of the first hydraulic control directional valve, and the first working oil port of the first hydraulic control directional valve and the second working oil port of the first hydraulic control directional valve can be communicated with the oil return port of the first hydraulic control directional valve.
As an alternative of a hydraulic dumping control system of a dump truck, the hydraulic control pilot handle has an ascending gear, a descending gear and a stopping gear, an oil inlet of the control valve is communicated with an oil outlet of the gear pump, when the hydraulic control pilot handle is in the ascending gear, the oil inlet of the control valve is communicated with a first working oil port of the control valve, the first working oil port of the control valve is communicated with a second hydraulic control end of the first hydraulic control reversing valve, so that the oil inlet of the first hydraulic control reversing valve is communicated with the first working oil port of the first hydraulic control reversing valve, and the second working oil port of the first hydraulic control reversing valve is communicated with an oil return port of the first hydraulic control reversing valve;
when the pilot operated handle is positioned at the descending gear, the oil inlet of the control valve is communicated with the second working oil port of the control valve, the second working oil port of the control valve is communicated with the first pilot operated end of the first pilot operated directional control valve, the oil inlet of the first pilot operated directional control valve can be communicated with the second working oil port of the first pilot operated directional control valve, and the first working oil port of the first pilot operated directional control valve is communicated with the oil return port of the first pilot operated directional control valve;
when the pilot operated handle is in the stop gear position, the oil inlet of the control valve is communicated with the oil return port of the control valve, and the oil return port of the control valve is communicated with the oil tank.
As an alternative of a hydraulic dumping control system of a dump truck, the automatic floating valve further comprises a second hydraulic control reversing valve, an oil inlet of the second hydraulic control reversing valve is communicated with an oil outlet of the electromagnetic reversing valve, an oil outlet of the second hydraulic control reversing valve is communicated with a first hydraulic control end of the first hydraulic control reversing valve, a hydraulic control end of the second hydraulic control reversing valve is communicated with a first working oil port of the control valve, an oil inlet of the second hydraulic control reversing valve is communicated with an oil return port of the second hydraulic control reversing valve, and the oil return port of the second hydraulic control reversing valve is communicated with the oil tank.
As an alternative of the hydraulic dumping control system of the dump truck, a first check valve is arranged between the second working oil port of the control valve and the oil outlet of the second hydraulic control reversing valve, and the first check valve is used for one-way communication of the second working oil port of the control valve to the first hydraulic control end of the first hydraulic control reversing valve.
As an alternative of a hydraulic dumping control system of the dumper, the second hydraulic control reversing valve is a two-position three-way hydraulic control reversing valve, and the electromagnetic reversing valve is a two-position two-way electromagnetic reversing valve.
As an alternative of the hydraulic dumping control system of the dump truck, the hydraulic control pilot handle comprises a magnet, and the magnet is arranged on one side close to the descending gear and can be magnetically connected with an operating rod of the hydraulic control pilot handle.
As an alternative of the hydraulic dumping control system of the dump truck, the hydraulic dumping control system further comprises an unloading valve, and the unloading valve is arranged between the gear pump and the control valve and between the gear pump and the automatic float valve.
As an alternative of a hydraulic dumping control system of a dump truck, the unloading valve comprises an energy accumulator, a pressure reducing valve and a second one-way valve, an oil outlet of the gear pump is communicated with an oil port of the energy accumulator and an oil inlet of the pressure reducing valve through the second one-way valve, and an oil outlet of the pressure reducing valve is communicated with an oil inlet of the control valve or an oil inlet of the electromagnetic directional valve.
As an optional scheme of a hydraulic dumping control system of a dump truck, the unloading valve further comprises a sequence valve, a hydraulic control end of the sequence valve is communicated with an oil port of the energy accumulator, an oil inlet of the sequence valve can be communicated with an oil outlet of the gear pump, and an oil outlet of the sequence valve is communicated with an oil tank.
The hydraulic dumping control method of the dump truck adopts the hydraulic dumping control system of the dump truck in any scheme, the hydraulic control pilot handle has a descending gear, and the hydraulic dumping control method comprises the following steps:
when the pilot-controlled pilot handle is operated to the descending gear, pilot oil of the gear pump enters the first pilot-controlled end of the first pilot-controlled reversing valve through the second working oil port of the control valve, and driving oil entering the first pilot-controlled reversing valve is communicated with the rod cavity of the dumping oil cylinder through the second working oil port of the first pilot-controlled reversing valve to drive the piston rod of the dumping oil cylinder to contract so as to enable the container to descend;
the cargo box descends to a set position and triggers the displacement sensor, the displacement sensor sends a signal to the control end of the electromagnetic directional valve, so that the electromagnetic directional valve is opened, pilot oil of the gear pump enters the first hydraulic control end of the first hydraulic control directional valve through the electromagnetic directional valve, a first working oil port of the first hydraulic control directional valve and a second working oil port of the first hydraulic control directional valve are communicated with an oil tank, and the dumping oil cylinder is in a floating state.
As an alternative of the hydraulic dumping control method of the dump truck, the automatic floating valve further comprises a second hydraulic control reversing valve, and the hydraulic control pilot handle has a rising gear; the hydraulic dump control method further comprises the steps of:
when the hydraulic control pilot handle is operated to a lifting gear, pilot oil of a first working oil port of the control valve enters a hydraulic control end of the second hydraulic control reversing valve, an oil inlet of the second hydraulic control reversing valve is communicated with an oil return port of the second hydraulic control reversing valve, the electromagnetic reversing valve enters the pilot oil of the first hydraulic control end of the first hydraulic control reversing valve through the second hydraulic control reversing valve and is cut off, an oil outlet of the gear pump is communicated with the oil inlet of the control valve, the pilot oil enters a second hydraulic control end of the first hydraulic control reversing valve through a first working oil port of the control valve, and at the moment, driving oil entering the first hydraulic control reversing valve is communicated with a rodless cavity of the dumping oil cylinder through a first working oil port of the first hydraulic control reversing valve to drive a piston rod of the dumping oil cylinder to extend so that the container rises.
As an alternative of the hydraulic dumping control method for the dump truck, the hydraulic dumping control system further includes an unloading valve, the unloading valve includes an accumulator and a sequence valve, the pilot-operated handle has a stop gear, and the hydraulic dumping control method further includes the steps of:
when the pilot control handle is operated to the stop gear, pilot oil pressure of the gear pump rises, and oil at an oil outlet of the gear pump enters the energy accumulator to charge the energy accumulator;
when the oil pressure of an oil port of the energy accumulator reaches the set charging pressure of the energy accumulator, the sequence valve is opened, and pilot oil of an oil outlet of the gear pump enters the sequence valve and flows back to the oil tank through the oil outlet of the sequence valve.
The invention has the beneficial effects that:
the invention provides a hydraulic dumping control system of a dump truck, which is characterized in that a displacement sensor is arranged on a frame and used for detecting the distance from a container to the frame, the hydraulic dumping control system comprises an automatic floating valve, the automatic floating valve comprises an electromagnetic directional valve, when the displacement sensor detects that the frame descends to a set position, a signal is sent to a control end of the electromagnetic directional valve, the electromagnetic directional valve is opened, an oil inlet of the electromagnetic directional valve can be communicated with an oil outlet of a gear pump, an oil outlet of the electromagnetic directional valve is communicated with a first hydraulic control end of a first hydraulic control directional valve, so that pilot oil provided by the gear pump enters the first hydraulic control end of the first hydraulic control directional valve through the electromagnetic directional valve, a first working oil port and a second working oil port of the first hydraulic control directional valve are both communicated with an oil return port of the first hydraulic directional valve, a rodless cavity and a rod cavity of a dumping oil cylinder are both communicated with an oil tank, and the dumping oil cylinder is in a floating state. According to the hydraulic dumping control system of the dump truck, a driver does not need to operate the hydraulic control pilot handle, when the container moves to the position where the displacement sensor can sense the container, a signal is sent to the electromagnetic directional valve, so that the dumping oil cylinder is automatically in a floating state, the impact of the container on the frame caused by misoperation of the driver and the impact of impact load caused by bumping of goods and the road surface on the dumping oil cylinder are avoided, the service lives of the frame and the dumping oil cylinder are prolonged, and the driving experience of the driver is improved.
The invention provides a hydraulic dumping control method of a dump truck, which is characterized in that the hydraulic dumping control system of the dump truck is applied, a cargo box starts to descend by operating a hydraulic control pilot handle to a descending gear, when the cargo box descends to a set position, a displacement sensor is triggered, the displacement sensor sends a signal to a control end of an electromagnetic directional valve, the electromagnetic directional valve is opened, an oil inlet of the electromagnetic directional valve is communicated with an oil outlet of a gear pump, pilot oil enters a first hydraulic control end of a first hydraulic control directional valve through the electromagnetic directional valve, a valve core of the first hydraulic control directional valve moves, a rodless cavity and a rod cavity of a dumping oil cylinder are both communicated with an oil tank, and the dumping oil cylinder is automatically in a floating state. The hydraulic dumping control method of the dump truck can prolong the service life of the frame and the dumping oil cylinder and improve the driving experience of a driver.
Drawings
FIG. 1 is a schematic diagram of a hydraulic dump control system of a dump truck in the prior art;
fig. 2 is a schematic diagram of a hydraulic dump control system of a dump truck according to an embodiment of the present invention.
In the figure:
1' and a hydraulic oil cylinder; 2' and a hydraulic control multi-way valve; 3', a hydraulic control valve; 4', a pilot pump; 5', a pressure pump;
100. a cargo box; 200. a frame; 300. a displacement sensor;
1. dumping an oil cylinder; 2. a first hydraulic control directional control valve; 3. a control valve; 4. a gear pump; 5. an automatic float valve; 6. an unloading valve; 7. a first check valve; 8. a pressure source;
51. an electromagnetic directional valve; 52. a second hydraulic control directional control valve; 61. an accumulator; 62. a pressure reducing valve; 63. a second one-way valve; 64. a sequence valve; 65. an overflow valve.
Detailed Description
Reference will now be made in detail to the embodiments of the present invention, examples of which are illustrated in the accompanying drawings, wherein like reference numerals refer to the same or similar elements or elements having the same or similar functions throughout. The embodiments described below with reference to the drawings are illustrative and intended to be illustrative of the invention and are not to be construed as limiting the 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 the like are used for descriptive purposes only and are not to be construed as indicating or implying relative importance. Wherein the terms "first position" and "second position" are two different positions.
Unless expressly stated or limited otherwise, the terms "mounted," "connected," and "secured" are to be construed broadly and encompass, for example, both fixed and removable connections; can be mechanically or electrically connected; either directly or indirectly through intervening media, either internally or in any other relationship. The specific meanings of the above terms in the present invention can be understood by those skilled in the art according to specific situations.
Unless expressly stated or limited otherwise, the first feature "on" or "under" the second feature may include the first feature being in direct contact with the second feature, or may include the first feature being in direct contact with the second feature but being in contact with the second feature by another feature therebetween. Also, the first feature being "on," "above" and "over" the second feature includes the first feature being directly on and obliquely above the second feature, or merely indicating that the first feature is at a higher level than the second feature. A first feature being "under," "below," and "beneath" a second feature includes the first feature being directly under and obliquely below the second feature, or simply meaning that the first feature is at a lesser elevation than the second feature.
The technical scheme of the invention is further explained by the specific implementation mode in combination with the attached drawings.
As shown in fig. 2, the present embodiment provides a hydraulic dumping control system for a dump truck, where the dump truck includes a cargo box 100 and a frame 200, the hydraulic dumping control system includes a dumping cylinder 1, a first hydraulic control directional valve 2, a gear pump 4 and a hydraulic control pilot handle, the gear pump 4 provides pilot oil for a control valve 3 of the hydraulic control pilot handle, the control valve 3 is connected with the dumping cylinder 1 through the first hydraulic control directional valve 2, a first working oil port of the first hydraulic control directional valve 2 is communicated with a rod-free cavity of the dumping cylinder 1, and a second working oil port of the first hydraulic control directional valve 2 is communicated with a rod-containing cavity of the dumping cylinder 1. An oil inlet of the first hydraulic control reversing valve 2 is communicated with the pressure source 8, and an oil return port of the first hydraulic control reversing valve 2 is communicated with an oil tank.
The pressure source 8 provides driving oil for the dumping oil cylinder 1, and the first hydraulic control reversing valve 2 is a four-position four-way hydraulic control reversing valve and comprises an ascending position, a stopping position, a descending position and a floating position; when the valve core of the first hydraulic control reversing valve 2 moves to the ascending position, the oil inlet of the first hydraulic control reversing valve 2 is communicated with the first working oil port of the first hydraulic control reversing valve 2, the second working oil port of the first hydraulic control reversing valve 2 is communicated with the oil return port of the first hydraulic control reversing valve 2, the driving oil entering the first hydraulic control reversing valve 2 enters the rodless cavity of the dump oil cylinder 1 to drive the piston rod of the dump oil cylinder 1 to move, the piston rod extends to drive the container 100 to ascend, and the oil in the rod cavity of the dump oil cylinder 1 returns through the oil return port of the first hydraulic control reversing valve 2.
When the valve core of the first hydraulic control reversing valve 2 moves to the stop position, the oil inlet and the oil return opening of the first hydraulic control reversing valve 2 are both closed, and the dumping oil cylinder 1 does not work.
When the valve core of the first hydraulic control reversing valve 2 moves to the descending position, the oil inlet of the first hydraulic control reversing valve 2 is communicated with the second working oil port of the first hydraulic control reversing valve 2, the first working oil port of the first hydraulic control reversing valve 2 is communicated with the oil return port of the first hydraulic control reversing valve 2, driving oil of the pressure source 8 enters the rod cavity of the dumping oil cylinder 1 through the first hydraulic control reversing valve 2, the piston rod contracts to drive the container 100 to descend, and oil in the rodless cavity of the dumping oil cylinder 1 returns through the oil return port of the first hydraulic control reversing valve 2.
When the valve core of the first hydraulic control reversing valve 2 moves to the floating position, the oil inlet of the first hydraulic control reversing valve 2 is closed, the first working oil port and the second working oil port of the first hydraulic control reversing valve 2 are communicated with the oil tank, so that the rodless cavity and the rod cavity of the dumping oil cylinder 1 are communicated with the oil tank, and the dumping oil cylinder 1 is in a floating state.
In order to avoid the situation that when the cargo box 100 descends to be close to the frame 200 due to misoperation of a driver and the dump truck is loaded or runs, the valve core of the first hydraulic control reversing valve 2 cannot move to a floating position in time, so that the cargo box 100 impacts the frame 200 and impact load caused by cargo loading and road surface bumping impacts the dump cylinder 1, and the service lives of the frame 200 and the dump cylinder 1 are influenced. In the hydraulic dump control system of the dump truck according to the present embodiment, the frame 200 is provided with the displacement sensor 300, and the displacement sensor 300 is used for detecting the distance between the cargo box 100 and the frame 200. The hydraulic dumping control system further comprises an automatic floating valve 5, the automatic floating valve 5 comprises an electromagnetic directional valve 51, the control end of the electromagnetic directional valve 51 is in signal connection with the displacement sensor 300, the oil inlet of the electromagnetic directional valve 51 can be communicated with the oil outlet of the gear pump 4, the oil outlet of the electromagnetic directional valve 51 is communicated with the first hydraulic control end of the first hydraulic control directional valve 2, and the first working oil port of the first hydraulic control directional valve 2 and the second working oil port of the first hydraulic control directional valve 2 can be communicated with the oil return port of the first hydraulic control directional valve 2.
The hydraulic dumping control system of the dump truck provided by the embodiment, a driver does not need to operate a pilot operated pilot handle, when the cargo box 100 moves to the position where the displacement sensor 300 can sense the cargo box 100, the displacement sensor 300 can send a signal to the control end of the electromagnetic directional valve 51, the electromagnetic directional valve 51 is opened, so that pilot oil enters the first pilot operated end of the first pilot operated directional valve 2 through the electromagnetic directional valve 51, the pilot oil drives the valve core of the first pilot operated directional valve 2 to move to the floating position, the dumping oil cylinder 1 is automatically in the floating state, thereby avoiding the impact of the cargo box 100 to the truck frame 200 caused by the misoperation of the driver, avoiding the impact of impact load caused by the cargo and road surface bumping to the dumping oil cylinder 1, prolonging the service lives of the truck frame 200 and the dumping oil cylinder 1, and improving the driving experience of the driver.
The displacement sensor 300 may be a proximity switch, when the cargo box 100 descends to a position (i.e., a position close to the vehicle frame 200) that can be sensed by the proximity switch, the proximity switch may trigger the control end of the electromagnetic directional valve 51, the control end of the electromagnetic directional valve 51 is opened after receiving a signal, so that the oil inlet of the electromagnetic directional valve 51 is communicated with the oil outlet of the gear pump 4, at this time, the pressure of the oil inlet of the electromagnetic directional valve 51 is less than the pressure of the oil inlet of the control valve 3 of the pilot operated handle, the pilot oil provided by the gear pump 4 may enter the oil inlet of the electromagnetic directional valve 51, thereby entering the first pilot operated end of the first pilot operated directional valve 2, at this time, the pressure of the pilot oil at the first pilot operated end of the first pilot operated directional valve 2 may push the spool of the first pilot operated directional valve 2 to move to a floating position, so that the dump cylinder 1 is in a floating state.
The hydraulic control pilot handle has an ascending gear, a descending gear and a stopping gear, an oil inlet of the control valve 3 is communicated with an oil outlet of the gear pump 4, when the hydraulic control pilot handle is in the ascending gear, an oil inlet of the control valve 3 is communicated with a first working oil port of the control valve 3, a first working oil port of the control valve 3 is communicated with a second hydraulic end of the first hydraulic control reversing valve 2, a pressure driving valve core of pilot oil entering the second hydraulic end of the first hydraulic control reversing valve 2 moves to the ascending position, the oil inlet of the first hydraulic control reversing valve 2 is communicated with the first working oil port of the first hydraulic control reversing valve 2, driving oil provided by the pressure source 8 enters a rodless cavity of the dumping oil cylinder 1, a second working oil port of the first hydraulic control reversing valve 2 is communicated with an oil return port of the first hydraulic control reversing valve 2, a piston rod of the driving oil cylinder 1 extends, and accordingly the container 100 ascends.
When the pilot-controlled pilot handle is in a descending gear, an oil inlet of the control valve 3 is communicated with a second working oil port of the control valve 3, the second working oil port of the control valve 3 is communicated with a first pilot-controlled end of the first pilot-controlled reversing valve 2, the pressure of pilot oil entering the first pilot-controlled end of the first pilot-controlled reversing valve 2 pushes the valve element to move to a descending position, the oil inlet of the first pilot-controlled reversing valve 2 can be communicated with the second working oil port of the first pilot-controlled reversing valve 2, driving oil provided by the pressure source 8 enters a rod cavity of the dumping oil cylinder 1, and the first working oil port of the first pilot-controlled reversing valve 2 is communicated with an oil return port of the first pilot-controlled reversing valve 2; the piston rod of the dump cylinder 1 is driven to retract, thereby lowering the cargo box 100.
In order to extend the piston rod of the dump cylinder 1 in the floating state when the pilot control handle is operated to the up shift position, the pilot oil supplied from the electromagnetic directional valve 51 to the first pilot control end of the first pilot control directional valve 2 needs to be cut off. The automatic floating valve 5 further comprises a second hydraulic control reversing valve 52, an oil inlet of the second hydraulic control reversing valve 52 is communicated with an oil outlet of the electromagnetic reversing valve 51, an oil outlet of the second hydraulic control reversing valve 52 is communicated with a first hydraulic control end of the first hydraulic control reversing valve 2, a hydraulic control end of the second hydraulic control reversing valve 52 is communicated with a first working oil port of the control valve 3, an oil inlet of the second hydraulic control reversing valve 52 can be communicated with an oil return port of the second hydraulic control reversing valve 52, and an oil return port of the second hydraulic control reversing valve 52 is communicated with an oil tank. By arranging the second hydraulic control reversing valve 52, when the hydraulic control pilot handle is operated to the ascending position, pilot oil flowing out from the first working oil port of the control valve 3 firstly enters the hydraulic control end of the second hydraulic control reversing valve 52, the valve core of the second hydraulic control reversing valve 52 is driven to move, the oil outlet of the second hydraulic control reversing valve 52 is sealed, so that the pressure of the oil inlet of the electromagnetic reversing valve 51 is increased, the pilot oil provided by the gear pump 4 can enter the control valve 3 through the oil inlet of the control valve 3 and enters the second hydraulic control end of the first hydraulic control reversing valve 2 through the first working oil port of the control valve 3, the valve core of the first hydraulic control reversing valve 2 is driven to move to the ascending position, the rodless cavity of the dumping oil cylinder 1 is used for oil inlet, the rod cavity is used for oil return, and the piston rod extends to drive the cargo box 100 to ascend.
In order to prevent the pilot oil from entering from the electromagnetic directional valve 51, the pilot oil flowing out of the oil outlet of the second hydraulic directional valve 52 enters the second working oil port of the control valve 3, a first check valve 7 is arranged between the second working oil port of the control valve 3 and the oil outlet of the second hydraulic directional valve 52, and the first check valve 7 is used for one-way communication of the second working oil port of the control valve 3 to the first hydraulic control end of the first hydraulic directional valve 2.
Optionally, the second hydraulic control directional valve 52 is a two-position three-way hydraulic control directional valve, and the electromagnetic directional valve 51 is a two-position two-way electromagnetic directional valve.
When the pilot operated handle is in the stop gear position, the oil inlet of the control valve 3 is communicated with the oil return port of the control valve 3, and the oil return port of the control valve 3 is communicated with the oil tank. At this time, no pilot oil drives the first pilot-controlled directional control valve 2, and the spool of the first pilot-controlled directional control valve 2 moves to the stop position.
In order to realize the pressure relief of the pilot oil provided by the gear pump 4, the hydraulic dumping control system further comprises an unloading valve 6, and the unloading valve 6 is arranged between the gear pump 4 and the control valve 3 and the automatic floating valve 5. When the pilot control handle of liquid accuse operated to stop to keep off the position, realized the pressure release of the guide fluid that gear pump 4 flows out, avoided getting back to gear pump 4 again from the guide fluid that gear pump 4 flows out, caused the damage to gear pump 4.
Specifically, the unloading valve 6 comprises an energy accumulator 61, a pressure reducing valve 62 and a second check valve 63, an oil outlet of the gear pump 4 is communicated with an oil port of the energy accumulator 61 and an oil inlet of the pressure reducing valve 62 through the second check valve 63, and an oil outlet of the pressure reducing valve 62 is communicated with an oil inlet of the control valve 3 or an oil inlet of the electromagnetic directional valve 51. The pressure of the pilot oil supplied by the gear pump 4 is controlled by a pressure reducing valve 62. When the pilot control handle is operated to the stop gear, the pressure of the oil outlet of the gear pump 4 rises, and at the moment, pilot oil enters the energy accumulator 61 to charge the energy accumulator 61.
The unloading valve 6 further comprises a sequence valve 64, a hydraulic control end of the sequence valve 64 is communicated with an oil port of the energy accumulator 61, an oil inlet of the sequence valve 64 can be communicated with an oil outlet of the gear pump 4, and an oil outlet of the sequence valve 64 is communicated with an oil tank. When the accumulator 61 is filled with oil, if the pressure of the oil outlet of the gear pump 4 does not reach the rated pressure, when the pressure of the oil outlet of the accumulator 61 reaches the set charging pressure, the sequence valve 64 is opened, and the pilot oil flowing out of the oil outlet of the gear pump 4 flows into the sequence valve 64 through the oil inlet of the sequence valve 64 and then flows back to the oil tank for unloading.
In addition, after the dump truck is stopped, the energy accumulator 61 can still ensure that the pilot control pilot handle acts, when the pilot control pilot handle is operated to a descending gear, pilot oil stored in the energy accumulator 61 enters the control valve 3 and then enters the first pilot control end of the first pilot control reversing valve 2 through the second working oil port of the control valve 3 to drive the valve core of the first pilot control reversing valve 2 to move to a descending position, and driving oil provided by the pressure source 8 enters the rod cavity of the dumping oil cylinder 1 to drive the container 100 to descend, so that the container 100 cannot be put down after the dump truck is stopped.
The unloading valve 6 further comprises an overflow valve 65, an oil inlet of the overflow valve 65 is communicated with an oil outlet of the gear pump 4, and an oil outlet of the overflow valve 65 is communicated with an oil tank. When the pressure of the oil outlet of the gear pump 4 reaches the overflow pressure, the pressure can overflow through the overflow valve 65, and the gear pump 4 is protected.
In this embodiment, the relief pressure of the relief valve 65 is set to be higher than the set charging pressure of the accumulator 61, and the sequence valve 64 functions to save energy and prevent the gear pump 4 from being in a relief state during operation.
Optionally, the pilot operated handle includes magnet, and magnet sets up in the one side that is close to the decline fender position, can inhale with the action bars magnetism of pilot operated handle and be connected. When the pilot operated handle of liquid accuse operated to descending to keep off the position, the magnet actuation with the action bars actuation of pilot operated handle of liquid accuse to can liberate both hands, reduce driver's fatigue strength, improve and drive and experience.
The embodiment also provides a hydraulic dumping control method of the dump truck, which adopts the hydraulic dumping control system of the dump truck, and the hydraulic dumping control method comprises the following steps:
when the pilot control pilot handle is operated to a descending gear, pilot oil of the gear pump 4 enters the first pilot control end of the first pilot control reversing valve 2 through the second working oil port of the control valve 3, driving oil entering the first pilot control reversing valve 2 is communicated with the rod cavity of the dumping oil cylinder 1 through the second working oil port of the first pilot control reversing valve 2, and a piston rod of the dumping oil cylinder 1 is driven to contract, so that the container 100 descends.
The container 100 is lowered to the set position and the displacement sensor 300 is triggered. The displacement sensor 300 sends a signal to the control end of the electromagnetic directional valve 51, so that the electromagnetic directional valve 51 is opened, the pilot oil of the gear pump 4 enters the first hydraulic control end of the first hydraulic control directional valve 2 through the electromagnetic directional valve 51, the first working oil port of the first hydraulic control directional valve 2 and the second working oil port of the first hydraulic control directional valve 2 are both communicated with the oil tank, and the dump oil cylinder 1 is in a floating state.
When the pilot-controlled pilot handle is operated to a lifting gear, pilot oil of a first working oil port of the control valve 3 enters a pilot-controlled end of the second hydraulic-controlled reversing valve 52, an oil inlet of the second hydraulic-controlled reversing valve 52 is communicated with an oil return port of the second hydraulic-controlled reversing valve 52, pilot oil of the electromagnetic reversing valve 51 entering the first hydraulic-controlled end of the first hydraulic-controlled reversing valve 2 through the second hydraulic-controlled reversing valve 52 is cut off, an oil outlet of the gear pump 4 is communicated with an oil inlet of the control valve 3, the pilot oil enters a second hydraulic-controlled end of the first hydraulic-controlled reversing valve 2 through a first working oil port of the control valve 3, at the moment, driving oil entering the first hydraulic-controlled reversing valve 2 is communicated with a rodless cavity of the dumping oil cylinder 1 through a first working oil port of the first hydraulic-controlled reversing valve 2, and a piston rod of the dumping oil cylinder 1 is driven to extend, so that the cargo box 100 rises.
When the pilot control handle is operated to a stop gear, the pilot oil pressure of the gear pump 4 is increased, and meanwhile, oil in an oil outlet of the gear pump 4 enters the energy accumulator 61 to charge the energy accumulator 61;
when the oil pressure of the oil port of the accumulator 61 reaches the set charging pressure of the accumulator 61, the sequence valve 64 is opened, and the pilot oil at the oil port of the gear pump 4 enters the sequence valve 64 and flows back to the oil tank through the oil port of the sequence valve 64.
The hydraulic dumping control method of the dump truck can prolong the service life of the frame 200 and the dumping oil cylinder 1 and improve the driving experience of a driver.
The above description is only a preferred embodiment of the present invention, and for those skilled in the art, the present invention should not be limited by the description of the present invention, which should be interpreted as a limitation.
Claims (12)
1. The hydraulic dumping control system of the dump truck comprises a cargo box (100) and a frame (200), the hydraulic dumping control system comprises a dumping oil cylinder (1), a first hydraulic control reversing valve (2), a gear pump (4) and a hydraulic control pilot handle, the gear pump (4) provides pilot oil for a control valve (3) of the hydraulic control pilot handle, the control valve (3) is connected with the dumping oil cylinder (1) through the first hydraulic control reversing valve (2), a first working oil port of the first hydraulic control reversing valve (2) is communicated with a rodless cavity of the dumping oil cylinder (1), and a second working oil port of the first reversing valve (2) is communicated with a rod cavity of the dumping oil cylinder (1); it is characterized in that the preparation method is characterized in that,
a displacement sensor (300) is arranged on the frame (200), and the displacement sensor (300) is used for detecting the distance between the container (100) and the frame (200);
the hydraulic dumping control system further comprises an automatic floating valve (5), the automatic floating valve (5) comprises an electromagnetic directional valve (51), the control end of the electromagnetic directional valve (51) is in signal connection with the displacement sensor (300), an oil inlet of the electromagnetic directional valve (51) can be communicated with an oil outlet of the gear pump (4), an oil outlet of the electromagnetic directional valve (51) is communicated with a first hydraulic control end of the first hydraulic control directional valve (2), and a first working oil port of the first hydraulic control directional valve (2) and a second working oil port of the first hydraulic control directional valve (2) can be communicated with an oil return port of the first hydraulic control directional valve (2).
2. The hydraulic dumping control system of the dump truck according to claim 1, wherein the hydraulic pilot control handle has an ascending gear, a descending gear and a stopping gear, an oil inlet of the control valve (3) is communicated with an oil outlet of the gear pump (4), when the hydraulic pilot control handle is in the ascending gear, the oil inlet of the control valve (3) is communicated with a first working oil port of the control valve (3), a first working oil port of the control valve (3) is communicated with a second hydraulic control end of the first hydraulic control directional valve (2), so that the oil inlet of the first hydraulic control directional valve (2) is communicated with the first working oil port of the first hydraulic control directional valve (2), and a second working oil port of the first hydraulic control directional valve (2) is communicated with an oil return port of the first hydraulic control directional valve (2);
when the pilot operated pilot handle is positioned at the descending gear, an oil inlet of the control valve (3) is communicated with a second working oil port of the control valve (3), the second working oil port of the control valve (3) is communicated with a first pilot operated end of the first pilot operated directional control valve (2), so that the oil inlet of the first pilot operated directional control valve (2) is communicated with a second working oil port of the first pilot operated directional control valve (2), and a first working oil port of the first pilot operated directional control valve (2) is communicated with an oil return port of the first pilot operated directional control valve (2);
when the pilot operated handle is in the stop gear position, the oil inlet of the control valve (3) is communicated with the oil return port of the control valve (3), and the oil return port of the control valve (3) is communicated with the oil tank.
3. The hydraulic dumping control system of the dump truck according to claim 2, wherein the automatic floating valve (5) further comprises a second hydraulic control directional control valve (52), an oil inlet of the second hydraulic control directional control valve (52) is communicated with an oil outlet of the electromagnetic directional control valve (51), an oil outlet of the second hydraulic control directional control valve (52) is communicated with a first hydraulic control end of the first hydraulic control directional control valve (2), a hydraulic control end of the second hydraulic control directional control valve (52) is communicated with a first working oil port of the control valve (3), so that an oil inlet of the second hydraulic control directional control valve (52) is communicated with an oil return port of the second hydraulic control directional control valve (52), and an oil return port of the second hydraulic control directional control valve (52) is communicated with the oil tank.
4. The hydraulic dumping control system of a dump truck according to claim 3, wherein a first check valve (7) is arranged between a second working oil port of the control valve (3) and an oil outlet of the second hydraulic control directional valve (52), and the first check valve (7) is used for one-way communication of the second working oil port of the control valve (3) to the first hydraulic control end of the first hydraulic control directional valve (2).
5. The hydraulic dump control system of a dump truck according to claim 3, wherein the second hydraulic control directional valve (52) is a two-position three-way hydraulic control directional valve, and the electromagnetic directional valve (51) is a two-position two-way electromagnetic directional valve.
6. The hydraulic dump control system of claim 2 wherein the pilot operated handle comprises a magnet disposed on a side of the hydraulic dump truck adjacent the lower gear position and magnetically engageable with the lever of the pilot operated handle.
7. The hydraulic dump control system of the dump truck as claimed in claim 1, characterized in that the hydraulic dump control system further comprises an unloading valve (6), and the unloading valve (6) is arranged between the gear pump (4) and the control valve (3) and the automatic float valve (5).
8. The hydraulic dumping control system of a dump truck according to claim 7, wherein the unloading valve (6) comprises an energy accumulator (61), a pressure reducing valve (62) and a second check valve (63), an oil outlet of the gear pump (4) is communicated with an oil port of the energy accumulator (61) and an oil inlet of the pressure reducing valve (62) through the second check valve (63), and an oil outlet of the pressure reducing valve (62) is communicated with an oil inlet of the control valve (3) or an oil inlet of the electromagnetic directional valve (51).
9. The hydraulic dump control system of the dump truck as set forth in claim 8, wherein the unloading valve (6) further comprises a sequence valve (64), a hydraulic control end of the sequence valve (64) is communicated with an oil port of the accumulator (61), an oil inlet of the sequence valve (64) can be communicated with an oil outlet of the gear pump (4), and an oil outlet of the sequence valve (64) is communicated with an oil tank.
10. A hydraulic dump control method for a dump truck, characterized in that the hydraulic dump control system for a dump truck according to any one of claims 1 to 9 is used, the pilot-operated handle has a down shift, and the hydraulic dump control method comprises the steps of:
when the pilot-controlled pilot handle is operated to the descending gear, pilot oil of the gear pump (4) enters a first pilot-controlled end of the first pilot-controlled reversing valve (2) through a second working oil port of the control valve (3), driving oil entering the first pilot-controlled reversing valve (2) is communicated with a rod cavity of the dumping oil cylinder (1) through a second working oil port of the first pilot-controlled reversing valve (2), and a piston rod of the dumping oil cylinder (1) is driven to contract so that the container (100) descends;
the container (100) is lowered to a set position and the displacement sensor (300) is triggered; the displacement sensor (300) sends a signal to the control end of the electromagnetic directional valve (51), so that the electromagnetic directional valve (51) is opened, the pilot oil of the gear pump (4) passes through the electromagnetic directional valve (51) enters the first hydraulic control end of the first hydraulic control directional valve (2), so that the first working oil port of the first hydraulic control directional valve (2) and the second working oil port of the first hydraulic control directional valve (2) are communicated with the oil tank, and the dump oil cylinder (1) is in a floating state.
11. The hydraulic dump control method of a dump truck according to claim 10, wherein the automatic float valve (5) further comprises a second hydraulic directional control valve (52), and the hydraulic pilot control handle has an ascending gear; the hydraulic dump control method further comprises the steps of:
when the hydraulic control pilot handle is operated to a lifting gear, pilot oil of a first working oil port of the control valve (3) enters a hydraulic control end of the second hydraulic control reversing valve (52), an oil inlet of the second hydraulic control reversing valve (52) is communicated with an oil return port of the second hydraulic control reversing valve (52), the electromagnetic reversing valve (51) enters a pilot oil port of a first hydraulic control end of the first hydraulic control reversing valve (2) through the second hydraulic control reversing valve (52) and is cut off, an oil outlet of the gear pump (4) is communicated with an oil inlet of the control valve (3), the pilot oil enters a second hydraulic control end of the first hydraulic control reversing valve (2) through a first working oil port of the control valve (3), and driving oil entering the first hydraulic control reversing valve (2) is communicated with a rodless cavity of the dumping oil cylinder (1) through a first working oil port of the first hydraulic control reversing valve (2) at the moment to drive a piston rod of the dumping oil cylinder (1) to extend so that the cargo box (100) rises.
12. The hydraulic dump control method for a dump truck according to claim 10, wherein the hydraulic dump control system further comprises an unloading valve (6), the unloading valve (6) comprises an accumulator (61) and a sequence valve (64), the pilot-controlled pilot handle has a stop gear, and the hydraulic dump control method further comprises the steps of:
when the pilot control pilot handle is operated to the stop gear, the pilot oil pressure of the gear pump (4) rises, and simultaneously oil at an oil outlet of the gear pump (4) enters the energy accumulator (61) to charge the energy accumulator (61);
when the oil pressure of the oil port of the energy accumulator (61) reaches the set charging pressure of the energy accumulator (61), the sequence valve (64) is opened, the pilot oil at the oil outlet of the gear pump (4) enters the sequence valve (64), and flows back to the oil tank through the oil outlet of the sequence valve (64).
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