CN113719482A

CN113719482A - Hydraulic system and paver

Info

Publication number: CN113719482A
Application number: CN202111001348.9A
Authority: CN
Inventors: 刘涛; 王康; 刘启才
Original assignee: Hunan Sany Zhongyi Machinery Co Ltd
Current assignee: Hunan Sany Zhongyi Machinery Co Ltd
Priority date: 2021-08-30
Filing date: 2021-08-30
Publication date: 2021-11-30
Anticipated expiration: 2041-08-30
Also published as: CN113719482B

Abstract

The invention provides a hydraulic system and a paver, wherein the hydraulic system comprises a hydraulic cylinder, and the hydraulic cylinder comprises a rod cavity and a rodless cavity; the first check valve has a one-way conduction state and a two-way conduction state, and the first end of the first check valve is communicated with the rod cavity; a second check valve having a one-way communication state and a two-way communication state, a first end of the second check valve being in communication with a second end of the first check valve; and the first damper is connected with the first check valve or the second check valve in parallel. According to the hydraulic system provided by the invention, the first check valve and the second check valve are connected in series, and the first damper can realize the one-way conduction mode, the two-way conduction mode and the damping conduction mode of the oil circuit of the hydraulic system, so that different conduction modes can be selected according to different working conditions of equipment connected with the hydraulic system, different operation requirements of the equipment can be met, the structure is simple and practical, the control process is convenient, and the operation of a controller is convenient.

Description

Hydraulic system and paver

Technical Field

The invention relates to the technical field of vehicle engineering, in particular to a hydraulic system and a paver.

Background

The continuous development of highway construction in China puts higher requirements on the working performance of the paver, and particularly the requirement on the flatness of paved road surfaces is higher and higher. In order to improve the evenness of a paved surface, the screed is generally required to float in the paving process, namely, a rod cavity of a screed lifting oil cylinder is communicated with a rodless cavity.

In order to make the speed stable when the screed plate descends, most of the spreading machines increase damping on the lifting oil cylinder. However, when the ironing board is required to float after damping is increased, hysteresis and resistance are caused by damping, and real floating cannot be realized, so that starting impression or arching is caused.

Although the technical scheme that no damping exists when the ironing plate floats appears in the related technology, the ironing plate is generally realized by adopting a plurality of electromagnetic directional valves which are connected in parallel, the structure is relatively complex, the reliability of the system is low, and when any one electromagnetic valve fails, the ironing plate cannot be locked, so that safety accidents may occur.

Disclosure of Invention

The present invention is directed to solving or improving at least one of the technical problems of the prior art or the related art.

To this end, a first aspect of the invention proposes a hydraulic system.

A second aspect of the invention provides a paving machine.

In view of this, a first aspect of the present invention proposes a hydraulic system, including: the hydraulic cylinder comprises a rod cavity and a rodless cavity; the first check valve has a one-way conduction state and a two-way conduction state, and the first end of the first check valve is communicated with the rod cavity; a second check valve having a one-way communication state and a two-way communication state, a first end of the second check valve being in communication with a second end of the first check valve; the first damper is connected with the first check valve or the second check valve in parallel; when the first check valve and the second check valve are both in a one-way conduction state, the conduction directions of the first check valve and the second check valve are both directed to the first check valve by the second check valve.

The invention provides a hydraulic system which comprises a hydraulic cylinder, wherein the hydraulic cylinder comprises a rod cavity and a rodless cavity, and further comprises a first check valve and a second check valve which are connected in series, wherein the first end of the first check valve is communicated with the rod cavity, the first end of the second check valve is communicated with the second end of the first check valve, the first check valve and the second check valve respectively comprise a one-way conduction state and a two-way conduction state, and particularly, when the first check valve and the second check valve are both in the one-way conduction state, the second check valve points to the first check valve in the same direction. That is, when first check valve and second check valve are all in one-way conducting state, hydraulic oil in the hydraulic system can only flow to first check valve from the second check valve, and hydraulic oil also can only flow into the rod chamber of pneumatic cylinder, and when first check valve and second check valve are all in two-way conducting state, hydraulic oil can flow into the rod chamber and also can flow out from the rod chamber. Through the setting of the first check valve and the second check valve which are connected in series, the one-way conduction or the two-way conduction of the oil circuit of the hydraulic system can be realized. Further, the hydraulic system further includes a first damper connected in parallel with the first check valve or the second check valve. Through parallelly connected first attenuator and first check valve or second check valve, can control and be in one-way conducting state with parallelly connected first check valve or the second check valve of first attenuator, control another control valve simultaneously and be in two-way conducting state to can realize that the damping of hydraulic system oil circuit switches on, promptly, hydraulic oil realizes two-way damping through one in first check valve and the second check valve and switches on with first attenuator.

According to the hydraulic system provided by the invention, the first check valve and the second check valve are connected in series, and the first damper connected with the first check valve or the second check valve in parallel is arranged, so that the working states of the first check valve and the second check valve can be controlled, namely the first check valve and the second check valve are controlled to be in one-way conduction or two-way conduction, the one-way conduction mode, the two-way conduction mode and the damping conduction mode of an oil circuit of the hydraulic system can be realized, and further, different conduction modes can be selected according to different requirements of working conditions of equipment connected with the hydraulic system, so that different operation requirements of the equipment can be met.

According to the hydraulic system provided by the invention, the following additional technical characteristics can be provided:

in the above technical solution, further, the hydraulic system further includes: the first electromagnetic valve comprises a first interface, a second interface, a third interface and a fourth interface, and the first electromagnetic valve comprises a first working position, a second working position and a third working position; at a first working position of the first electromagnetic valve, the first interface is communicated with the third interface, and the second interface is communicated with the fourth interface; at a second working position of the first electromagnetic valve, the first interface is communicated with the fourth interface, and the second interface is communicated with the third interface; at a third working position of the first electromagnetic valve, the fourth port and the third port are both communicated with the second port; the first connector is communicated with the pressure oil port; the second interface is communicated with the oil return port; the third port is communicated with the second end of the second check valve; the fourth interface is communicated with a rodless cavity of the hydraulic cylinder.

In the technical solution, the hydraulic system further includes a first solenoid valve, the first solenoid valve is connected to a transmission pipeline for transmitting hydraulic oil in the hydraulic system, specifically, the first solenoid valve may include a Y-type three-position four-way valve, the first solenoid valve includes a first interface, a second interface, a third interface and a fourth interface, wherein the first interface is communicated with a pressure oil port of the hydraulic system, namely hydraulic oil enters the hydraulic system through the first interface, the second interface is communicated with an oil return port of the hydraulic system, namely hydraulic oil flows out of the hydraulic system through the second interface, the third interface is communicated with the second end of the second check valve, namely hydraulic oil can flow to the second check valve through the second interface, and then flows to the rod cavity of the hydraulic cylinder, and accordingly, the hydraulic oil flowing out of the rod cavity can flow into the first electromagnetic valve from the third interface through the first check valve and the second check valve; the fourth interface is communicated with a rodless cavity of the hydraulic cylinder, namely, hydraulic oil entering the first electromagnetic valve can flow to the rodless cavity through the fourth interface, and hydraulic oil flowing out of the rodless cavity can also flow into the first electromagnetic valve through the fourth interface.

Through the setting of first solenoid valve, when controlling hydraulic system, can adjust the operating position of first solenoid valve to realize the connection between the different interfaces of first solenoid valve, and then adjust the change of hydraulic oil flow path in the hydraulic system, and then realize the different mode of piston rod, realized hydraulic system's multifunctionality.

Further, the first solenoid valve includes first work position, second work position and third work position, and when first solenoid valve was in first work position, first interface and third interface intercommunication, second interface and fourth interface intercommunication to make hydraulic oil get into from hydraulic system's pressure hydraulic fluid port, the third interface of first interface of flow through, further flow through second check valve and first check valve and get into the pole chamber that has of pneumatic cylinder, so that the piston rod retracts, thereby realized the uninstallation operation of piston rod withdrawal pneumatic cylinder under the effort of hydraulic oil. It should be noted that, in the actual operation process, the component to which the piston rod is connected needs the piston rod to perform work in an unloading manner, that is, the piston rod needs a force for retracting the hydraulic cylinder, but the piston rod does not retract the hydraulic cylinder, specifically, taking the example that the hydraulic system is used for a paving machine, the piston rod is connected with the screed, where the unloading only provides a fixed upward acting force to reduce the downward acting force of the screed on the paving material, and the screed is not lifted (the piston rod retracts). Simultaneously, the first check valve and the second check valve are controlled not to be powered on, so that hydraulic oil can only flow into the rod cavity from the third interface and cannot flow out of the rod cavity, the retraction process of the piston rod is guaranteed not to stretch out, and safety accidents are avoided.

When the first electromagnetic valve is at the second working position, the first interface is communicated with the fourth interface, the second interface is communicated with the third interface, so that the hydraulic oil enters the first electromagnetic valve through the first interface and enters the rodless cavity of the hydraulic cylinder through the fourth interface to apply acting force to the hydraulic piston in the rodless cavity to push out the piston rod, thereby realizing the loading operation that the piston rod extends out of the hydraulic cylinder under the acting force of the hydraulic oil, and it should be noted that, in the actual operation process, the components connected with the piston rod need the piston rod to operate in a loading mode, but the piston rod does not extend out of the hydraulic cylinder, in particular, taking the example of a hydraulic system for a paver, the piston rod is connected with the screed plate, the piston rod has a downward acting force acting on the screed plate, but the piston rod may also be deactivated due to the supporting effect of the paving material, but this downward force is fixed. Simultaneously, control first check valve and the second check valve is not electrified for hydraulic oil that flows from having the pole chamber flows to the third interface of first solenoid valve through first check valve and the parallelly connected first attenuator of second check valve, when having realized that the piston rod stretches out, through the damping effect of first attenuator, avoids the piston rod to stretch out too fast and lead to the accident. Furthermore, the hydraulic oil flows to an oil return port of the hydraulic system through the second interface, and the circulation of the hydraulic oil is completed.

When the first electromagnetic valve is located at the third working position, the second interface is communicated with the third interface, and simultaneously the second interface is communicated with the fourth interface, so that the rod cavity of the hydraulic cylinder is communicated with the rodless cavity through the first check valve, the second check valve and the first electromagnetic valve, and simultaneously the second interface of the first electromagnetic valve can be communicated with an oil return port of the hydraulic system. And, control first check valve and second check valve all are in two-way conducting state for hydraulic oil can freely pass in and out from first check valve and second check valve has the pole chamber, makes hydraulic oil free flow in hydraulic system and can not receive the resistance effect, and then has realized the unsteady mode of operation of piston rod, also promptly the piston rod can freely stretch out or retract under the effect of external force, in order to promote the responsiveness.

In any of the above technical solutions, further, the hydraulic system further includes: and the inlet of the second electromagnetic valve is communicated with the pressure oil port, the outlet of the second electromagnetic valve is communicated with the rod cavity, and the inlet of the second electromagnetic valve and the outlet of the second electromagnetic valve can be selectively communicated or disconnected.

In the technical scheme, the hydraulic system can be further provided with a second electromagnetic valve, an inlet of the second electromagnetic valve is communicated with the oil inlet, and an outlet of the second electromagnetic valve is communicated with the rodless cavity of the hydraulic cylinder. Through the setting of second solenoid valve, can make hydraulic oil directly get into there being the pole chamber through floating valve group, specifically: and controlling the second electromagnetic valve to be electrified so that the hydraulic oil can flow into the rod cavity of the hydraulic cylinder through the inlet of the second electromagnetic valve, thereby pushing the hydraulic piston to enable the piston rod to retract into the rod cavity. Meanwhile, hydraulic oil flowing out of the rod cavity can flow through the first electromagnetic valve to the oil outlet, and oil circuit circulation is completed. Further, the inlet of the second electromagnetic valve and the outlet of the second electromagnetic valve can be selectively communicated or disconnected, so that when the second electromagnetic valve is not powered, the inlet and the outlet of the second electromagnetic valve are disconnected, and hydraulic oil does not circulate through the second electromagnetic valve.

Through the setting of second solenoid valve, when control piston rod withdrawal pneumatic cylinder, need not to control first check valve and second check valve, hydraulic system's control process can be simplified in relevant operational environment, promotes the convenience.

In any of the above technical solutions, further, the hydraulic system further includes: the one-way valve is arranged on a communication pipeline between the outlet of the second electromagnetic valve and the rod cavity; the hydraulic oil can be conducted in one way through the one-way valve along the direction from the second electromagnetic valve to the rod cavity.

In this technical scheme, hydraulic system still including set up in the export of second solenoid valve and have the check valve between the pole chamber to, hydraulic oil can be followed second solenoid valve and to have the one-way conduction of direction in pole chamber. Through the setting of check valve, can be so that at the in-process that the piston rod withdraws back through second solenoid valve control, avoid the hydraulic oil backward flow to avoid the piston rod to stretch out suddenly, the hydraulic system's that further improves security.

In any of the above technical solutions, further, the hydraulic system further includes: and the second damper is arranged between the outlet of the second electromagnetic valve and the one-way valve.

In this technical scheme, between the export of second solenoid valve and check valve, can also be provided with the second attenuator, through the setting of second attenuator, can play the removal damping effect to the flow of hydraulic oil, avoid hydraulic oil to flow at the excessive speed that leads to the piston rod to withdraw at the excessive speed, further promoted hydraulic system's security.

In any of the above technical solutions, further, the hydraulic system further includes: a pressure reducing valve; the first end of the pressure reducing valve is communicated with the pressure oil port of the oil inlet; the second end of the pressure reducing valve is communicated with a first interface of the first electromagnetic valve; the third end of the pressure reducing valve is communicated with the oil return port.

In this technical scheme, hydraulic system can also be provided with the relief pressure valve, specifically, the first end and the pressure hydraulic fluid port of relief pressure valve are linked together, the second end and the first interface of first solenoid valve of relief pressure valve are linked together, the third end and the oil return opening of relief pressure valve are linked together, also promptly, before hydraulic oil gets into first solenoid valve through the first interface of first solenoid valve, at first can pass through the relief pressure valve to make hydraulic oil at first adjust the pressure of hydraulic oil through the relief pressure valve before getting into first solenoid valve, thereby accurately control the size of the effort of loading and uninstallation.

In any of the above technical solutions, further, the hydraulic system further includes: the pressure oil source is communicated with the pressure oil port; the oil tank is communicated with the oil return port.

In this technical scheme, through the setting of pressure oil source, can provide drive power for the hydraulic oil in the hydraulic system to in driving the hydraulic oil from the pressure hydraulic fluid port to the hydraulic system with the hydraulic oil in the oil tank, realize the circulation of hydraulic oil, further, the oil return opening is linked together with the oil tank, and hydraulic oil after the hydraulic system circulation can flow to the oil tank in from the oil return opening.

In any of the above technical solutions, further, the first damper is a throttle valve.

According to a second aspect of the invention, there is provided a paver comprising: a screed plate; the hydraulic cylinder comprises a rod cavity and a rodless cavity; the first check valve has a one-way conduction state and a two-way conduction state, and the first end of the first check valve is communicated with the rod cavity; a second check valve having a one-way communication state and a two-way communication state, a first end of the second check valve being in communication with a second end of the first check valve; the first damper is connected with the first check valve or the second check valve in parallel; when the first check valve and the second check valve are both in a one-way conduction state, the conduction directions of the first check valve and the second check valve are both pointed to the first check valve by the second check valve; the screed is connected with a piston rod of the hydraulic cylinder.

The invention provides a paver, which comprises a hydraulic cylinder, wherein the hydraulic cylinder comprises a rod cavity and a rodless cavity, and further comprises a first check valve and a second check valve which are connected in series, wherein the first end of the first check valve is communicated with the rod cavity, the first end of the second check valve is communicated with the second end of the first check valve, the first check valve and the second check valve respectively comprise a one-way conduction state and a two-way conduction state, and particularly, when the first check valve and the second check valve are both in the one-way conduction state, the second check valve points to the first check valve in the same direction. That is, when first check valve and second check valve are all in one-way conducting state, hydraulic oil in the hydraulic system can only flow to first check valve from the second check valve, and hydraulic oil also can only flow into the rod chamber of pneumatic cylinder, and when first check valve and second check valve are all in two-way conducting state, hydraulic oil can flow into the rod chamber and also can flow out from the rod chamber. Through the setting of the first check valve and the second check valve which are connected in series, the one-way conduction or the two-way conduction of the oil circuit of the hydraulic system can be realized. Further, the hydraulic system further includes a first damper connected in parallel with the first check valve or the second check valve. Through parallelly connected first attenuator and first check valve or second check valve, can control and be in one-way conducting state with parallelly connected first check valve or the second check valve of first attenuator, control another control valve simultaneously and be in two-way conducting state to can realize that the damping of hydraulic system oil circuit switches on, promptly, hydraulic oil realizes two-way damping through one in first check valve and the second check valve and switches on with first attenuator. Further, the paver still includes: the hydraulic cylinder comprises a rod cavity and a rodless cavity; the first end of the first check valve is communicated with the rod cavity; the screed is connected with a piston rod of the hydraulic cylinder.

According to the paver provided by the invention, the first check valve and the second check valve are connected in series, and the first damper connected with the first check valve or the second check valve in parallel is arranged, so that the working positions of the first check valve and the second check valve can be controlled, namely the first check valve and the second check valve are controlled to be in one-way conduction or two-way conduction, the one-way conduction mode, the two-way conduction mode and the damping conduction mode of an oil circuit of a hydraulic system can be realized, and further the screed of the paver can be controlled to perform floating operation, lifting operation and other operation modes so as to meet the operation requirements of the paver, the paver is simple and practical in structure, convenient in control process and convenient for operators to operate.

Further, the paver also includes: the first electromagnetic valve comprises a first interface, a second interface, a third interface and a fourth interface, and the first electromagnetic valve comprises a first working position, a second working position and a third working position; at a first working position of the first electromagnetic valve, the first interface is communicated with the third interface, and the second interface is communicated with the fourth interface; at a second working position of the first electromagnetic valve, the first interface is communicated with the fourth interface, and the second interface is communicated with the third interface; at a third working position of the first electromagnetic valve, the fourth port and the third port are both communicated with the second port; the first connector is communicated with the pressure oil port; the second interface is communicated with the oil return port; the third port is communicated with the second end of the second check valve; the fourth interface is communicated with a rodless cavity of the hydraulic cylinder.

Specifically, the paver further comprises a first electromagnetic valve, the first electromagnetic valve is connected to a transmission pipeline for transmitting hydraulic oil in the hydraulic system, specifically, the first electromagnetic valve may comprise a Y-shaped three-position four-way valve, the first electromagnetic valve comprises a first interface, a second interface, a third interface and a fourth interface, wherein the first interface is communicated with a pressure oil port of the hydraulic system, namely hydraulic oil enters the hydraulic system through the first interface, the second interface is communicated with an oil return port of the hydraulic system, namely hydraulic oil flows out of the hydraulic system through the second interface, the third interface is communicated with the second end of the second check valve, namely hydraulic oil can flow to the second check valve through the second interface, and then flows to the rod cavity of the hydraulic cylinder, and accordingly, the hydraulic oil flowing out of the rod cavity can flow into the first electromagnetic valve from the third interface through the first check valve and the second check valve; the fourth interface is communicated with a rodless cavity of the hydraulic cylinder, namely, hydraulic oil entering the first electromagnetic valve can flow to the rodless cavity through the fourth interface, and hydraulic oil flowing out of the rodless cavity can also flow into the first electromagnetic valve through the fourth interface.

Through the setting of first solenoid valve, when controlling the paver, can adjust the operating position of first solenoid valve to realize the connection between the different interfaces of first solenoid valve, and then adjust the change of hydraulic oil flow path in the hydraulic system, and then realize the different mode of piston rod, realized the multifunctionality when paver screed moves.

Further, the first solenoid valve includes first work position, second work position and third work position, and when first solenoid valve was in first work position, first interface and third interface intercommunication, second interface and fourth interface intercommunication to make hydraulic oil get into from hydraulic system's pressure hydraulic fluid port, the third interface of first interface of flow through, further flow through second check valve and first check valve and get into the pole chamber that has of pneumatic cylinder, so that the piston rod retracts, thereby realized the uninstallation operation of piston rod withdrawal pneumatic cylinder under the effort of hydraulic oil. It should be noted that, in the actual operation process, the component to which the piston rod is connected needs the piston rod to perform work in an unloading manner, that is, the piston rod needs a force to retract the hydraulic cylinder, but the piston rod does not retract the hydraulic cylinder. Simultaneously, the first check valve and the second check valve are controlled not to be powered on, so that hydraulic oil can only flow into the rod cavity from the third interface and cannot flow out of the rod cavity, the retraction process of the piston rod is guaranteed not to stretch out, and safety accidents are avoided.

When the first electromagnetic valve is located at the second working position, the first interface is communicated with the fourth interface, and the second interface is communicated with the third interface, so that hydraulic oil enters the first electromagnetic valve through the first interface and flows into the rodless cavity of the hydraulic cylinder through the fourth interface to exert acting force on the hydraulic piston in the rodless cavity to push out the piston rod, and loading operation that the piston rod extends out of the hydraulic cylinder under the acting force of the hydraulic oil is realized. It should be noted that, in the actual operation process, the components connected to the piston rod require the piston rod to perform work in a loading manner, but the piston rod does not extend out of the hydraulic cylinder. Simultaneously, control first check valve and the second check valve is not electrified for hydraulic oil that flows from having the pole chamber flows to the third interface of first solenoid valve through first check valve and the parallelly connected first attenuator of second check valve, when having realized that the piston rod stretches out, through the damping effect of first attenuator, avoids the piston rod to stretch out too fast and lead to the accident. Furthermore, the hydraulic oil flows to an oil return port of the hydraulic system through the second interface, and the circulation of the hydraulic oil is completed.

Further, the paver also includes: and the inlet of the second electromagnetic valve is communicated with the pressure oil port, the outlet of the second electromagnetic valve is communicated with the rod cavity, and the inlet of the second electromagnetic valve and the outlet of the second electromagnetic valve can be selectively communicated or disconnected.

Specifically, the hydraulic system can be further provided with a second electromagnetic valve, an inlet of the second electromagnetic valve is communicated with the oil inlet, and an outlet of the second electromagnetic valve is communicated with the rodless cavity of the hydraulic cylinder. Through the setting of second solenoid valve, can make hydraulic oil directly get into there being the pole chamber through floating valve group, specifically: and controlling the second electromagnetic valve to be electrified so that the hydraulic oil can flow into the rod cavity of the hydraulic cylinder through the inlet of the second electromagnetic valve, thereby pushing the hydraulic piston to enable the piston rod to retract into the rod cavity. Meanwhile, hydraulic oil flowing out of the rod cavity can flow through the first electromagnetic valve to the oil outlet, and oil circuit circulation is completed. Further, the inlet of the second electromagnetic valve and the outlet of the second electromagnetic valve can be selectively communicated or disconnected, so that when the second electromagnetic valve is not powered, the inlet and the outlet of the second electromagnetic valve are disconnected, and hydraulic oil does not circulate through the second electromagnetic valve.

Further, the paver also includes: the one-way valve is arranged on a communication pipeline between the outlet of the second electromagnetic valve and the rod cavity; the hydraulic oil can be conducted in one way through the one-way valve along the direction from the second electromagnetic valve to the rod cavity.

Specifically, the hydraulic system further comprises a one-way valve arranged between the outlet of the second electromagnetic valve and the rod cavity, and the hydraulic oil can be conducted in one way along the direction from the second electromagnetic valve to the rod cavity. Through the setting of check valve, can be so that at the in-process that the piston rod withdraws back through second solenoid valve control, avoid the hydraulic oil backward flow to avoid the piston rod to stretch out suddenly, the hydraulic system's that further improves security.

Further, the paver also includes: and the second damper is arranged between the outlet of the second electromagnetic valve and the one-way valve.

Specifically, between the export of second solenoid valve and check valve, can also be provided with the second attenuator, through the setting of second attenuator, can play the removal damping effect to the flow of hydraulic oil, avoid hydraulic oil to flow at the excessive speed that leads to the piston rod withdrawal too fast, further promoted hydraulic system's security.

Further, the paver also includes: a pressure reducing valve; the first end of the pressure reducing valve is communicated with the pressure oil port of the oil inlet; the second end of the pressure reducing valve is communicated with a first interface of the first electromagnetic valve; the third end of the pressure reducing valve is communicated with the oil return port.

Specifically, hydraulic system can also be provided with the relief pressure valve, specifically, the first end and the pressure hydraulic fluid port of relief pressure valve are linked together, the second end and the first interface of first solenoid valve of relief pressure valve are linked together, the third end and the oil return opening of relief pressure valve are linked together, also promptly, before hydraulic oil gets into first solenoid valve through the first interface of first solenoid valve, at first can pass through the relief pressure valve to make hydraulic oil at first adjust the pressure of hydraulic oil through the relief pressure valve before getting into first solenoid valve, thereby accurately control the size of the effort of loading and uninstallation.

Further, the paver also includes: the pressure oil source is communicated with the pressure oil port; the oil tank is communicated with the oil return port.

Further, the first damper is a throttle valve.

In any one of the above technical solutions, further, the paver includes a first operating state, a second operating state, a third operating state, a fourth operating state, and a fifth operating state.

When the paver is in a first working state, the first check valve and the second check valve are both in a two-way conduction state, the first electromagnetic valve is in a third working position, the inlet of the second electromagnetic valve is disconnected with the outlet of the second electromagnetic valve, so that the rod cavity is communicated with the rodless cavity, and the rod cavity and the rodless cavity are both communicated with the oil return port.

In the technical scheme, the paver is provided with a first working state, at the moment, the first electromagnetic valve is in a third working position, the second interface is communicated with the third interface, and meanwhile, the second interface is communicated with the fourth interface, so that a rod cavity of the hydraulic cylinder is communicated with a rodless cavity through the first check valve, the second check valve and the first electromagnetic valve, and meanwhile, the second interface of the first electromagnetic valve can be communicated with an oil return port of a hydraulic system. And, control first check valve and second check valve all are in the state of getting electric for hydraulic oil can freely pass in and out from first check valve and second check valve has the pole chamber, makes hydraulic oil free flow in hydraulic system and can not receive the resistance effect, and then has realized the floating operation mode of screed, also the piston rod can freely stretch out or retract under the effect of external force, in order to promote the responsiveness.

Further, when the paver is in a second working state, the check valve connected with the first damper in parallel in the first check valve and the second check valve is in a one-way conduction state, the other check valve is in a two-way conduction state, the first electromagnetic valve is in a first working position, and the inlet of the second electromagnetic valve is disconnected with the outlet of the second electromagnetic valve, so that the rodless cavity is communicated with the pressure oil port, and the rod cavity is communicated with the oil return port.

Specifically, the paver has a second working state, at this time, the first electromagnetic valve is in a second working position, the first interface is communicated with the fourth interface, and the second interface is communicated with the third interface, so that hydraulic oil enters the first electromagnetic valve through the first interface and flows through the fourth interface to enter the rodless cavity of the hydraulic cylinder, and an acting force is applied to the hydraulic piston in the rodless cavity to push out the piston rod, so that the loading operation of the screed plate under the acting force of the hydraulic oil is realized. Meanwhile, the check valve connected with the first damper in parallel in the first check valve and the second check valve is controlled to be in a one-way conduction state, the other check valve is in a two-way conduction state, and the inlet of the second electromagnetic valve is disconnected with the outlet of the second electromagnetic valve, so that hydraulic oil flowing out of the rod cavity flows to the third interface of the first electromagnetic valve through one of the first check valve and the second check valve and the first damper, the ironing plate is loaded, and meanwhile, accidents caused by the fact that the ironing plate stretches out too fast are avoided through the damping effect of the first damper. Furthermore, the hydraulic oil flows to an oil return port of the hydraulic system through the second interface, and the circulation of the hydraulic oil is completed.

Further, when the paver is in a third working state, the first check valve and the second check valve are both in a one-way conduction state, the first electromagnetic valve is in a first working position, an inlet of the second electromagnetic valve is disconnected with an outlet of the second electromagnetic valve, so that the rodless cavity is communicated with the oil return port, and the rod cavity is communicated with the pressure oil port.

Specifically, the paver has a third working state, at this time, the first electromagnetic valve is located at a first working position, the first interface is communicated with the third interface, the second interface is communicated with the fourth interface, an inlet of the second electromagnetic valve is disconnected with an outlet of the second electromagnetic valve, so that hydraulic oil enters from a pressure oil port of a hydraulic system and flows through the third interface of the first interface, and further flows through the second check valve and the first check valve to enter a rod cavity of the hydraulic cylinder, so that the piston rod retracts, thereby achieving the unloading operation of the screed under the action force of the hydraulic oil. Simultaneously, control first check valve and second check valve all are in one-way conducting state for hydraulic oil can only flow into there being the pole intracavity from the third interface, and unable follow has the pole intracavity to flow out, has guaranteed that the in-process of screed withdrawal can not fall back, avoids the incident.

Further, when the paver is in a fourth working state, one of the first check valve and the second check valve, which is connected with the first damper in parallel, is in a one-way conduction state, the other one of the first check valve and the second check valve is in a two-way conduction state, the first electromagnetic valve is in a third working position, and an inlet of the second electromagnetic valve is disconnected with an outlet of the second electromagnetic valve, so that the rod cavity is communicated with the rodless cavity and is communicated with the oil return port.

Specifically, the paver has a fourth operating condition, at this moment, one of the first check valve and the second check valve connected in parallel with the first damper is in a one-way conduction state, the other one is in a two-way conduction state, simultaneously, the first electromagnetic valve is controlled to be in the third working position, the inlet of the second electromagnetic valve and the outlet of the second electromagnetic valve are disconnected, and further, a rod cavity and a rodless cavity of the hydraulic cylinder are communicated, and simultaneously, the hydraulic cylinder is communicated with an oil return port of a hydraulic system, at this moment, hydraulic oil does not have driving force action, so that an ironing plate connected with the piston rod can freely fall under the action of gravity, so as to realize gravity descending operation of the paver, and through the setting of the damper, the falling process can be more stable, and accidents caused by too fast falling can be avoided.

Further, when the paver is in a fifth working state, an inlet of the second electromagnetic valve is communicated with an outlet of the second electromagnetic valve, the first check valve and the second check valve are both in a one-way conduction state, the first electromagnetic valve is in a third working position, so that the rod cavity is communicated with the pressure oil port, and the rodless cavity is communicated with the oil return port.

Specifically, the paver has a fifth operating condition, and at this moment, the import of second solenoid valve and the export intercommunication of second solenoid valve for hydraulic oil can flow in the pole chamber that has of pneumatic cylinder through the import of second solenoid valve, thereby promotes hydraulic piston, so that the piston rod contracts the screed that drives the paver and returns to there being the pole chamber, in order to realize the promotion operation of paver screed. Meanwhile, the first electromagnetic valve is controlled to be in a third working position, so that hydraulic oil flowing out of the rod cavity can flow through the first electromagnetic valve to the oil outlet, and oil circuit circulation is completed.

Additional aspects and advantages of the invention will be set forth in part in the description which follows, and in part will be obvious from the description, or may be learned by practice of the invention.

Drawings

The above and/or additional aspects and advantages of the present invention will become apparent and readily appreciated from the following description of the embodiments, taken in conjunction with the accompanying drawings of which:

FIG. 1 illustrates a schematic diagram of a hydraulic system provided by an embodiment of the present invention;

FIG. 2 is a schematic diagram illustrating the configuration of the hydraulic system of FIG. 1 in a float mode of operation;

FIG. 3 is a schematic diagram illustrating the configuration of the hydraulic system of FIG. 1 in a loading mode of operation;

FIG. 4 is a schematic diagram illustrating the configuration of the hydraulic system of FIG. 1 in an unloaded mode of operation;

FIG. 5 is a schematic diagram illustrating the hydraulic system of FIG. 1 in a lift mode of operation;

FIG. 6 is a schematic diagram illustrating the hydraulic system of FIG. 1 in a gravity-lowering mode;

wherein, the correspondence between the reference numbers and the part names in fig. 1 to 6 is:

100 hydraulic system, 110 hydraulic cylinder, 112 rod chamber, 114 rodless chamber, 122 first check valve, 124 second check valve, 126 first damper, 130 first solenoid valve, 140 second solenoid valve, 150 check valve, 160 second damper, 170 pressure reducing valve, 180 oil through valve block.

Detailed Description

In order that the above objects, features and advantages of the present invention can be more clearly understood, a more particular description of the invention will be rendered by reference to the appended drawings. It should be noted that the embodiments and features of the embodiments of the present application may be combined with each other without conflict.

In the following description, numerous specific details are set forth in order to provide a thorough understanding of the present invention, however, the present invention may be practiced in other ways than those specifically described herein, and therefore the scope of the present invention is not limited by the specific embodiments disclosed below.

A hydraulic system and paving machine according to some embodiments of the invention are described below with reference to fig. 1-6.

As shown in fig. 1, a first aspect of the present invention proposes a hydraulic system 100, comprising: a hydraulic cylinder 110, the hydraulic cylinder 110 including a rod chamber 112 and a rodless chamber 114; a first check valve 122, the first check valve 122 having a one-way communication state and a two-way communication state, a first end of the first check valve 122 being in communication with the rod chamber 112; a second check valve 124, the second check valve 124 having a one-way conducting state and a two-way conducting state, a first end of the second check valve 124 communicating with a second end of the first check valve 122; a first damper 126, the first damper 126 being connected in parallel with the first check valve 122 or the second check valve 124; wherein, when the first check valve 122 and the second check valve 124 are both in the one-way communication state, the communication directions of the first check valve 122 and the second check valve 124 are both directed to the first check valve 122 by the second check valve 124.

The hydraulic system 100 provided by the invention comprises a hydraulic cylinder 110, wherein the hydraulic cylinder 110 comprises a rod cavity 112 and a rodless cavity 114, and further comprises a first check valve 122 and a second check valve 124 which are connected in series, wherein a first end of the first check valve 122 is communicated with the rod cavity 112, a first end of the second check valve 124 is communicated with a second end of the first check valve 122, and the first check valve 122 and the second check valve 124 both comprise a one-way conduction state and a two-way conduction state, and particularly, when the first check valve 122 and the second check valve 124 are both in the one-way conduction state, the first check valve 122 and the second check valve 124 are both directed to the first check valve 122 by the second check valve 124 in the same direction. That is, when the first check valve 122 and the second check valve 124 are both in the one-way communication state, hydraulic oil in the hydraulic system 100 can only flow from the second check valve 124 to the first check valve 122, that is, hydraulic oil can only flow into the rod chamber 112 of the hydraulic cylinder 110, and when the first check valve 122 and the second check valve 124 are both in the two-way communication state, hydraulic oil can both flow into the rod chamber 112 and flow out of the rod chamber 112. Through the arrangement of the first check valve 122 and the second check valve 124 which are connected in series, one-way conduction or two-way conduction of the oil circuit of the hydraulic system 100 can be realized. Further, the hydraulic system 100 also includes a first damper 126, the first damper 126 being connected in parallel with the first check valve 122 or the second check valve 124. By connecting the first damper 126 in parallel with the first check valve 122 or the second check valve 124, the first check valve 122 or the second check valve 124 connected in parallel with the first damper 126 can be controlled to be in a one-way conducting state, and the other control valve can be controlled to be in a two-way conducting state, so that the damping conduction of the oil path of the hydraulic system 100 can be realized, that is, the hydraulic oil can be in two-way damping conduction with the first damper 126 through one of the first check valve 122 and the second check valve 124.

The present invention provides a hydraulic system 100 that, by placing a first check valve 122 and a second check valve 124 in series, a first damper 126 is also provided in parallel with the first check valve 122 or the second check valve 124, thereby controlling the operating states of the first check valve 122 and the second check valve 124, i.e., controlling the first check valve 122 and the second check valve 124 in one-way communication or in two-way communication, so that the one-way conduction mode, the two-way conduction mode and the damping conduction mode of the oil circuit of the hydraulic system 100 can be realized, and thus the selection of different conduction modes may be made depending on the different devices to which hydraulic system 100 is connected, so that different conduction modes can be selected according to different requirements of the working conditions of the equipment connected with the hydraulic system 100, the device has the advantages of meeting different operation requirements of equipment, being simple and practical in structure, convenient in control process and convenient for operation of control personnel.

In the above embodiment, further, as shown in fig. 1 to 4, the hydraulic system 100 further includes: the first solenoid valve 130, the first solenoid valve 130 includes a first interface, a second interface, a third interface and a fourth interface, the first solenoid valve 130 includes a first working position, a second working position and a third working position; in the first working position of the first electromagnetic valve 130, the first port is communicated with the third port, and the second port is communicated with the fourth port; in the second working position of the first electromagnetic valve 130, the first port is communicated with the fourth port, and the second port is communicated with the third port; in the third working position of the first electromagnetic valve 130, the fourth port and the third port are both communicated with the second port; the first connector is communicated with the pressure oil port; the second interface is communicated with the oil return port; the third port communicates with a second end of the second check valve 124; the fourth port communicates with the rodless chamber 114 of the hydraulic cylinder 110.

In this embodiment, the hydraulic system 100 further includes a first solenoid valve 130, the first solenoid valve 130 is connected to a transmission line for transmitting hydraulic oil in the hydraulic system 100, specifically, the first solenoid valve 130 may include a Y-type three-position four-way valve, the first solenoid valve 130 includes a first port, a second port, a third port and a fourth port, wherein, the first port is communicated with the pressure port of the hydraulic system 100, that is, the hydraulic oil enters the hydraulic system 100 through the first port, the second port is communicated with the oil return port of the hydraulic system 100, that is, the hydraulic oil flows out of the hydraulic system 100 through the second port, the third port is communicated with the second end of the second check valve 124, that is, the hydraulic oil can flow to the second check valve 124 through the second port, and further to the rod chamber 112 of the hydraulic cylinder 110, and accordingly, the hydraulic oil flowing out of the rod chamber 112 can flow into the first solenoid valve 130 through the first check valve 122 and the second check valve 124 from the third port; the fourth port is connected to the rod-less chamber 114 of the hydraulic cylinder 110, that is, the hydraulic oil entering the first solenoid valve 130 can flow to the rod-less chamber 114 through the fourth port, and the hydraulic oil flowing out of the rod-less chamber 114 can also flow into the first solenoid valve 130 through the fourth port.

Through the setting of first solenoid valve 130, when controlling hydraulic system 100, can adjust the operating position of first solenoid valve 130 to realize the connection between the different interfaces of first solenoid valve 130, and then adjust the change of hydraulic oil flow path in hydraulic system 100, and then realize the different mode of piston rod, realized hydraulic system 100's multifunctionality.

Further, as shown in fig. 2, the first solenoid valve 130 includes a first operating position, a second operating position, and a third operating position. When the first solenoid valve 130 is in the first working position, the first port is communicated with the third port, and the second port is communicated with the fourth port, so that hydraulic oil enters from the pressure port of the hydraulic system 100, flows through the third port of the first port, further flows through the second check valve 124 and the first check valve 122, enters the rod chamber 112 of the hydraulic cylinder 110, so that the piston rod retracts, and therefore unloading operation of retracting the piston rod into the hydraulic cylinder 110 under the acting force of the hydraulic oil is realized. It should be noted that, in the actual operation process, the component to which the piston rod is connected needs the piston rod to perform work in an unloading manner, that is, the piston rod needs a force for retracting the hydraulic cylinder, but the piston rod does not retract the hydraulic cylinder, specifically, taking the example that the hydraulic system 100 is used for a paving machine, the piston rod is connected with the screed plate, where the unloading only provides a fixed upward acting force, reduces the downward acting force of the screed plate on the paving material, and does not lift the screed plate (the piston rod retracts). Meanwhile, the first check valve 122 and the second check valve 124 are controlled not to be powered, so that hydraulic oil can only flow into the rod cavity 112 from the third interface and cannot flow out of the rod cavity 112, the piston rod is guaranteed not to extend out in the retraction process, and safety accidents are avoided.

Specifically, as shown in fig. 3, when the first electromagnetic valve 130 is in the second working position, the first port is communicated with the fourth port, and the second port is communicated with the third port, so that hydraulic oil enters the first electromagnetic valve 130 through the first port, flows through the fourth port, enters the rodless cavity 114 of the hydraulic cylinder 110, applies an acting force to the hydraulic piston in the rodless cavity 114, pushes out the piston rod, and thus, a loading operation is performed in which the piston rod extends out of the hydraulic cylinder 110 under the acting force of the hydraulic oil. It should be noted that, in the actual operation process, the component to which the piston rod is connected needs the piston rod to operate in a loading manner, but the piston rod does not extend out of the hydraulic cylinder, specifically, taking the example that the hydraulic system 100 is used for a paving machine, the piston rod is connected with a screed plate, and the downward acting force of the piston rod acts on the screed plate, but due to the supporting effect of the paving material, the piston rod may not act, but the downward acting force is fixed. Meanwhile, the first check valve 122 and the second check valve 124 are controlled to be powered, so that the hydraulic oil flowing out of the rod chamber 112 flows to the third interface of the first solenoid valve 130 through the first check valve 122 and the first damper 126 connected with the second check valve 124 in parallel, and when the piston rod extends out, accidents caused by the fact that the piston rod extends out too fast are avoided through the damping effect of the first damper 126. Further, the hydraulic oil flows to the oil return port of the hydraulic system 100 through the second port, and the circulation of the hydraulic oil is completed.

Specifically, as shown in fig. 4, when the first solenoid valve 130 is in the third operating position, the second port is communicated with the third port, and the second port is communicated with the fourth port, so that the rod chamber 112 of the hydraulic cylinder 110 is communicated with the rod-less chamber 114 through the first check valve 122, the second check valve 124 and the first solenoid valve 130, and is also communicated with the oil return port of the hydraulic system 100 through the second port of the first solenoid valve 130. And, the first check valve 122 and the second check valve 124 are controlled to be in the two-way conduction state, so that the hydraulic oil can freely flow in and out of the rod cavity 112 from the first check valve 122 and the second check valve 124, the hydraulic oil can freely flow in the hydraulic system 100 without being subjected to resistance, and then the floating operation mode of the piston rod is realized, that is, the piston rod can freely extend or retract under the action of external force, so as to improve the responsiveness.

In any of the above embodiments, further, as shown in fig. 1, the hydraulic system 100 further includes: and the inlet of the second solenoid valve 140 is communicated with the pressure oil port, the outlet of the second solenoid valve 140 is communicated with the rod chamber 112, and the inlet of the second solenoid valve 140 and the outlet of the second solenoid valve 140 can be selectively communicated or disconnected.

In this embodiment, the hydraulic system 100 may further be provided with a second solenoid valve 140, an inlet of the second solenoid valve 140 being in communication with the oil inlet, and an outlet being in communication with the rodless chamber 114 of the hydraulic cylinder 110. By the arrangement of the second solenoid valve 140, it is possible to make the hydraulic oil enter the rod chamber 112 directly without passing through the floating valve group, specifically: the second solenoid valve 140 is controlled to be energized so that hydraulic oil can flow into the rod chamber 112 of the hydraulic cylinder 110 through the inlet of the second solenoid valve 140, thereby pushing the hydraulic piston so that the piston rod is retracted into the rod chamber 112. At the same time, the hydraulic oil flowing out from the rod chamber 112 is allowed to flow through the first solenoid valve 130 to the oil outlet, completing the oil circuit circulation. Further, the inlet of the second solenoid valve 140 and the outlet of the second solenoid valve 140 may be selectively connected or disconnected, so that when the second solenoid valve 140 is not powered, the inlet and the outlet of the second solenoid valve 140 are disconnected, and the hydraulic oil is not circulated through the second solenoid valve 140.

Through the arrangement of the second solenoid valve 140, when the piston rod is controlled to retract into the hydraulic cylinder 110, the first check valve 122 and the second check valve 124 do not need to be controlled, the control process of the hydraulic system 100 can be simplified in the relevant operating environment, and convenience is improved.

In any of the above embodiments, further, as shown in fig. 1, the hydraulic system 100 further includes: a check valve 150 disposed on a communication line between the outlet of the second solenoid valve 140 and the rod chamber 112; hydraulic oil can be conducted in one direction through the check valve 150 in the direction from the second solenoid valve 140 to the rod chamber 112.

In this embodiment, the hydraulic system 100 further includes a check valve 150 disposed between the outlet of the second solenoid valve 140 and the rod chamber 112, and hydraulic oil can be conducted in one direction in the direction from the second solenoid valve 140 to the rod chamber 112. Through the arrangement of the check valve 150, the backflow of the hydraulic oil can be avoided during the process of controlling the retraction of the piston rod through the second electromagnetic valve 140, so that the piston rod is prevented from being suddenly extended, and the safety of the hydraulic system 100 is further improved.

In any of the above embodiments, further, as shown in fig. 1, the hydraulic system 100 further includes: and a second damper 160 disposed between the outlet of the second solenoid valve 140 and the check valve 150.

In this embodiment, a second damper 160 may be further disposed between the outlet of the second electromagnetic valve 140 and the check valve 150, and through the arrangement of the second damper 160, a movement damping effect may be performed on the flow of the hydraulic oil, so as to avoid that the speed of retraction of the piston rod is too fast due to too fast flow of the hydraulic oil, and further improve the safety of the hydraulic system 100.

In any of the above embodiments, further, as shown in fig. 1, the hydraulic system 100 further includes: a pressure reducing valve 170; a first end of the pressure reducing valve 170 is communicated with the oil inlet pressure port; a second end of the pressure reducing valve 170 is in communication with a first port of the first solenoid valve 130; the third end of the pressure reducing valve 170 communicates with the oil return port.

In this embodiment, the hydraulic system 100 may further be provided with a pressure reducing valve 170, specifically, a first end of the pressure reducing valve 170 is communicated with the pressure port, a second end of the pressure reducing valve 170 is communicated with the first port of the first electromagnetic valve 130, and a third end of the pressure reducing valve 170 is communicated with the oil return port, that is, before hydraulic oil enters the first electromagnetic valve 130 through the first port of the first electromagnetic valve 130, the hydraulic oil first passes through the pressure reducing valve 170, so that before the hydraulic oil enters the first electromagnetic valve 130, the pressure of the hydraulic oil is first adjusted through the pressure reducing valve 170, thereby accurately controlling the magnitude of the acting force for loading and unloading.

In any of the above embodiments, further, the hydraulic system 100 further includes: the pressure oil source is communicated with the pressure oil port; the oil tank is communicated with the oil return port.

In this embodiment, through the arrangement of the pressure oil source, a driving force can be provided for the hydraulic oil in the hydraulic system 100, so that the hydraulic oil in the oil tank is driven into the hydraulic system 100 from the pressure oil port, thereby realizing the circulation of the hydraulic oil, further, the oil return port is communicated with the oil tank, and the hydraulic oil circulated by the hydraulic system 100 can flow into the oil tank from the oil return port.

Further, the first damper 126 is a throttle valve.

According to a second aspect of the present invention, as shown in fig. 1 to 6, there is provided a paver comprising: a screed plate; a hydraulic cylinder 110, the hydraulic cylinder 110 including a rod chamber 112 and a rodless chamber 114; a first check valve 122, the first check valve 122 having a one-way communication state and a two-way communication state, a first end of the first check valve 122 being in communication with the rod chamber 112; a second check valve 124, the second check valve 124 having a one-way conducting state and a two-way conducting state, a first end of the second check valve 124 communicating with a second end of the first check valve 122; a first damper 126, the first damper 126 being connected in parallel with the first check valve 122 or the second check valve 124; when the first check valve 122 and the second check valve 124 are both in the one-way communication state, the communication directions of the first check valve 122 and the second check valve 124 are both directed to the first check valve 122 by the second check valve 124; the screed is connected to the piston rod of the hydraulic cylinder 110.

The paver provided by the invention comprises a hydraulic cylinder 110, wherein the hydraulic cylinder 110 comprises a rod cavity 112 and a rodless cavity 114, and further comprises a first check valve 122 and a second check valve 124 which are connected in series, wherein a first end of the first check valve 122 is communicated with the rod cavity 112, a first end of the second check valve 124 is communicated with a second end of the first check valve 122, the first check valve 122 and the second check valve 124 both comprise a one-way communication state and a two-way communication state, and particularly, when the first check valve 122 and the second check valve 124 are both in the one-way communication state, the first check valve 122 and the second check valve 124 are both directed to the first check valve 122 by the second check valve 124 in the same direction. That is, when the first check valve 122 and the second check valve 124 are both in the one-way communication state, hydraulic oil in the hydraulic system 100 can only flow from the second check valve 124 to the first check valve 122, that is, hydraulic oil can only flow into the rod chamber 112 of the hydraulic cylinder 110, and when the first check valve 122 and the second check valve 124 are both in the two-way communication state, hydraulic oil can both flow into the rod chamber 112 and flow out of the rod chamber 112. Through the arrangement of the first check valve 122 and the second check valve 124 which are connected in series, one-way conduction or two-way conduction of the oil circuit of the hydraulic system 100 can be realized. Further, the hydraulic system 100 also includes a first damper 126, the first damper 126 being connected in parallel with the first check valve 122 or the second check valve 124. By connecting the first damper 126 in parallel with the first check valve 122 or the second check valve 124, the first check valve 122 or the second check valve 124 connected in parallel with the first damper 126 can be controlled to be in a one-way conducting state, and the other control valve can be controlled to be in a two-way conducting state, so that the damping conduction of the oil path of the hydraulic system 100 can be realized, that is, the hydraulic oil can be in two-way damping conduction with the first damper 126 through one of the first check valve 122 and the second check valve 124. Further, the paver still includes: a hydraulic cylinder 110, the hydraulic cylinder 110 including a rod chamber 112 and a rodless chamber 114; a first end of the first check valve 122 communicates with the rod chamber 112; the screed is connected to the piston rod of the hydraulic cylinder 110.

According to the paver provided by the invention, the first check valve 122 and the second check valve 124 are connected in series, and the first damper 126 connected in parallel with the first check valve 122 or the second check valve 124 is arranged at the same time, so that the working positions of the first check valve 122 and the second check valve 124 can be controlled, namely the first check valve 122 and the second check valve 124 are controlled to be in one-way conduction or two-way conduction, and therefore, the one-way conduction mode, the two-way conduction mode and the damping conduction mode of an oil way of the hydraulic system 100 can be realized, and further, the screed of the paver can be controlled to perform floating operation, lifting operation and other operation modes, so that the operation requirements of the paver are met.

In the above embodiment, further, as shown in fig. 1, the paver further includes: the first solenoid valve 130, the first solenoid valve 130 includes a first interface, a second interface, a third interface and a fourth interface, the first solenoid valve 130 includes a first working position, a second working position and a third working position; in the first working position of the first electromagnetic valve 130, the first port is communicated with the third port, and the second port is communicated with the fourth port; in the second working position of the first electromagnetic valve 130, the first port is communicated with the fourth port, and the second port is communicated with the third port; in the third working position of the first electromagnetic valve 130, the fourth port and the third port are both communicated with the second port; the first connector is communicated with the pressure oil port; the second interface is communicated with the oil return port; the third port communicates with a second end of the second check valve 124; the fourth port communicates with the rodless chamber 114 of the hydraulic cylinder 110.

In this embodiment, the paver further comprises a first solenoid valve 130, the first solenoid valve 130 is connected to a transmission line for transmitting hydraulic oil in the hydraulic system 100, specifically, the first solenoid valve 130 may comprise a Y-type three-position four-way valve, the first solenoid valve 130 comprises a first interface, a second interface, a third interface and a fourth interface, wherein, the first port is communicated with the pressure port of the hydraulic system 100, that is, the hydraulic oil enters the hydraulic system 100 through the first port, the second port is communicated with the oil return port of the hydraulic system 100, that is, the hydraulic oil flows out of the hydraulic system 100 through the second port, the third port is communicated with the second end of the second check valve 124, that is, the hydraulic oil can flow to the second check valve 124 through the second port, and further to the rod chamber 112 of the hydraulic cylinder 110, and accordingly, the hydraulic oil flowing out of the rod chamber 112 can flow into the first solenoid valve 130 through the first check valve 122 and the second check valve 124 from the third port; the fourth port is connected to the rod-less chamber 114 of the hydraulic cylinder 110, that is, the hydraulic oil entering the first solenoid valve 130 can flow to the rod-less chamber 114 through the fourth port, and the hydraulic oil flowing out of the rod-less chamber 114 can also flow into the first solenoid valve 130 through the fourth port.

Through the setting of first solenoid valve 130, when controlling the paver, can adjust the operating position of first solenoid valve 130 to realize the connection between the different interfaces of first solenoid valve 130, and then adjust the change of hydraulic oil flow path in hydraulic system 100, and then realize the different mode of piston rod, realized the multifunctionality when paver screed moves.

Further, as shown in fig. 4, the first solenoid valve 130 includes a first working position, a second working position, and a third working position, when the first solenoid valve 130 is in the first working position, the first port is communicated with the third port, and the second port is communicated with the fourth port, so that hydraulic oil enters from the pressure port of the hydraulic system 100, flows through the third port of the first port, and further flows through the second check valve 124 and the first check valve 122 to enter the rod chamber 112 of the hydraulic cylinder 110, so as to retract the piston rod, thereby achieving the unloading operation of retracting the piston rod into the hydraulic cylinder 110 under the action force of the hydraulic oil. It should be noted that, in the actual operation process, the component to which the piston rod is connected needs the piston rod to perform work in an unloading manner, that is, the piston rod needs a force to retract the hydraulic cylinder, but the piston rod does not retract the hydraulic cylinder. Meanwhile, the first check valve 122 and the second check valve 124 are controlled not to be powered, so that hydraulic oil can only flow into the rod cavity 112 from the third interface and cannot flow out of the rod cavity 112, the piston rod is guaranteed not to extend out in the retraction process, and safety accidents are avoided.

Specifically, as shown in fig. 3, when the first electromagnetic valve 130 is in the second working position, the first port is communicated with the fourth port, and the second port is communicated with the third port, so that hydraulic oil enters the first electromagnetic valve 130 through the first port, flows through the fourth port, enters the rodless cavity 114 of the hydraulic cylinder 110, applies an acting force to the hydraulic piston in the rodless cavity 114, pushes out the piston rod, and thus, a loading operation is performed in which the piston rod extends out of the hydraulic cylinder 110 under the acting force of the hydraulic oil. It should be noted that, in the actual operation process, the components connected to the piston rod require the piston rod to perform work in a loading manner, but the piston rod does not extend out of the hydraulic cylinder. Meanwhile, the first check valve 122 and the second check valve 124 are controlled to be powered, so that the hydraulic oil flowing out of the rod chamber 112 flows to the third interface of the first solenoid valve 130 through the first check valve 122 and the first damper 126 connected with the second check valve 124 in parallel, and when the piston rod extends out, accidents caused by the fact that the piston rod extends out too fast are avoided through the damping effect of the first damper 126. Further, the hydraulic oil flows to the oil return port of the hydraulic system 100 through the second port, and the circulation of the hydraulic oil is completed.

Specifically, as shown in fig. 2, when the first solenoid valve 130 is in the third operating position, the second port is communicated with the third port, and the second port is communicated with the fourth port, so that the rod chamber 112 of the hydraulic cylinder 110 is communicated with the rod-less chamber 114 through the first check valve 122, the second check valve 124 and the first solenoid valve 130, and is also communicated with the oil return port of the hydraulic system 100 through the second port of the first solenoid valve 130. And, the first check valve 122 and the second check valve 124 are controlled to be in the two-way conduction state, so that the hydraulic oil can freely flow in and out of the rod cavity 112 from the first check valve 122 and the second check valve 124, the hydraulic oil can freely flow in the hydraulic system 100 without being subjected to resistance, and then the floating operation mode of the piston rod is realized, that is, the piston rod can freely extend or retract under the action of external force, so as to improve the responsiveness.

Further, as shown in fig. 1, the hydraulic system 100 further includes: and the inlet of the second solenoid valve 140 is communicated with the pressure oil port, the outlet of the second solenoid valve 140 is communicated with the rod chamber 112, and the inlet of the second solenoid valve 140 and the outlet of the second solenoid valve 140 can be selectively communicated or disconnected.

Specifically, the hydraulic system 100 may further be provided with a second solenoid valve 140, an inlet of the second solenoid valve 140 being communicated with the oil inlet, and an outlet being communicated with the rodless chamber 114 of the hydraulic cylinder 110. By the arrangement of the second solenoid valve 140, it is possible to make the hydraulic oil enter the rod chamber 112 directly without passing through the floating valve group, specifically: the second solenoid valve 140 is controlled to be energized so that hydraulic oil can flow into the rod chamber 112 of the hydraulic cylinder 110 through the inlet of the second solenoid valve 140, thereby pushing the hydraulic piston so that the piston rod is retracted into the rod chamber 112. At the same time, the hydraulic oil flowing out from the rod chamber 112 is allowed to flow through the first solenoid valve 130 to the oil outlet, completing the oil circuit circulation. Further, the inlet of the second solenoid valve 140 and the outlet of the second solenoid valve 140 may be selectively connected or disconnected, so that when the second solenoid valve 140 is not powered, the inlet and the outlet of the second solenoid valve 140 are disconnected, and the hydraulic oil is not circulated through the second solenoid valve 140.

Further, as shown in fig. 1, the hydraulic system 100 further includes: a check valve 150 disposed on a communication line between the outlet of the second solenoid valve 140 and the rod chamber 112; hydraulic oil can be conducted in one direction through the check valve 150 in the direction from the second solenoid valve 140 to the rod chamber 112.

Specifically, the hydraulic system 100 further includes a check valve 150 disposed between the outlet of the second solenoid valve 140 and the rod chamber 112, and hydraulic oil can be conducted in one direction in the direction from the second solenoid valve 140 to the rod chamber 112. Through the arrangement of the check valve 150, the backflow of the hydraulic oil can be avoided during the process of controlling the retraction of the piston rod through the second electromagnetic valve 140, so that the piston rod is prevented from being suddenly extended, and the safety of the hydraulic system 100 is further improved.

Further, as shown in fig. 1, the hydraulic system 100 further includes: and a second damper 160 disposed between the outlet of the second solenoid valve 140 and the check valve 150.

Specifically, a second damper 160 may be further disposed between the outlet of the second electromagnetic valve 140 and the check valve 150, and through the arrangement of the second damper 160, a movement damping effect may be performed on the flow of the hydraulic oil, so as to avoid that the speed of retraction of the piston rod is too fast due to too fast flow of the hydraulic oil, and further improve the safety of the hydraulic system 100.

Further, as shown in fig. 1, the hydraulic system 100 further includes: a pressure reducing valve 170; a first end of the pressure reducing valve 170 is communicated with the oil inlet pressure port; a second end of the pressure reducing valve 170 is in communication with a first port of the first solenoid valve 130; the third end of the pressure reducing valve 170 communicates with the oil return port.

Specifically, the hydraulic system 100 may further be provided with a pressure reducing valve 170, specifically, a first end of the pressure reducing valve 170 is communicated with the pressure port, a second end of the pressure reducing valve 170 is communicated with the first interface of the first electromagnetic valve 130, and a third end of the pressure reducing valve 170 is communicated with the oil return port, that is, before hydraulic oil enters the first electromagnetic valve 130 through the first interface of the first electromagnetic valve 130, the hydraulic oil first passes through the pressure reducing valve 170, so that the pressure of the hydraulic oil is first adjusted through the pressure reducing valve 170 before the hydraulic oil enters the first electromagnetic valve 130, thereby accurately controlling the magnitude of the acting force of loading and unloading.

Further, as shown in fig. 1, the hydraulic system 100 further includes: the pressure oil source is communicated with the pressure oil port; the oil tank is communicated with the oil return port.

Specifically, through the setting of the pressure oil source, a driving force can be provided for the hydraulic oil in the hydraulic system 100, so that the hydraulic oil in the oil tank is driven into the hydraulic system 100 from the pressure oil port, the circulation of the hydraulic oil is realized, further, the oil return port is communicated with the oil tank, and the hydraulic oil circulated by the hydraulic system 100 can flow into the oil tank from the oil return port.

Further, the first damper 126 is a throttle valve.

In any of the above embodiments, further, as shown in fig. 2, the paving machine includes a first operating state, a second operating state, a third operating state, a fourth operating state, and a fifth operating state.

In this embodiment, the paving machine has a first operating state in which the first solenoid valve 130 is in the third operating position, the second port is in communication with the third port, and the second port is in communication with the fourth port, such that the rod chamber 112 of the hydraulic cylinder 110 is in communication with the rodless chamber 114 through the first check valve 122, the second check valve 124, and the first solenoid valve 130, and is also in communication with the oil return port of the hydraulic system 100 through the second port of the first solenoid valve 130. And, the first check valve 122 and the second check valve 124 are controlled to be in an energized state, so that the hydraulic oil can freely flow in and out of the rod cavity 112 from the first check valve 122 and the second check valve 124, so that the hydraulic oil can freely flow in the hydraulic system 100 without being subjected to resistance, and further, a floating operation mode of the screed plate is realized, that is, the piston rod can freely extend or retract under the action of external force, so as to improve the responsiveness.

Further, as shown in fig. 3, when the paver is in the second working state, one of the first check valve 122 and the second check valve 124, which is connected in parallel with the first damper 126, is in a one-way conduction state, the other one is in a two-way conduction state, the first solenoid valve 130 is in the first working position, an inlet of the second solenoid valve 140 is disconnected from an outlet of the second solenoid valve 140, so that the rodless chamber 114 is communicated with the pressure oil port, and the rod chamber 112 is communicated with the oil return port.

Specifically, the paver has a second working state, at this time, the first electromagnetic valve 130 is located at a second working position, the first interface is communicated with the fourth interface, and the second interface is communicated with the third interface, so that hydraulic oil enters the first electromagnetic valve 130 through the first interface and enters the rodless cavity 114 of the hydraulic cylinder 110 through the fourth interface, an acting force is applied to the hydraulic piston in the rodless cavity 114, the piston rod is pushed out, and the loading operation of the screed plate under the acting force of the hydraulic oil is realized. In particular, the piston rod is connected to the screed, on which the downward force acts, but which may also be deactivated due to the supporting effect of the paving material, but which downward force is fixed. Meanwhile, one of the first check valve 122 and the second check valve 124, which is connected in parallel with the first damper 126, is in a one-way conduction state, the other one is in a two-way conduction state, and the inlet of the second solenoid valve 140 and the outlet of the second solenoid valve 140 are disconnected, so that the hydraulic oil flowing out of the rod chamber 112 flows to the third port of the first solenoid valve 130 through one of the first check valve 122 and the second check valve 124 and the first damper 126, and the accident caused by the quick extension of the screed is avoided through the damping effect of the first damper 126 while the screed is loaded. Further, the hydraulic oil flows to the oil return port of the hydraulic system 100 through the second port, and the circulation of the hydraulic oil is completed.

Further, as shown in fig. 4, when the paver is in the third working state, the first check valve 122 and the second check valve 124 are both in a one-way conduction state, the first electromagnetic valve 130 is in the first working position, and the inlet of the second electromagnetic valve 140 and the outlet of the second electromagnetic valve 140 are disconnected, so that the rodless cavity 114 is communicated with the oil return port, and the rod cavity 112 is communicated with the pressure oil port.

Specifically, the paver has a third operating state, at this time, the first electromagnetic valve 130 is in the first operating position, the first port is communicated with the third port, the second port is communicated with the fourth port, and the inlet of the second electromagnetic valve 140 is disconnected from the outlet of the second electromagnetic valve 140, so that hydraulic oil enters from the pressure oil port of the hydraulic system 100, flows through the third port of the first port, further flows through the second check valve 124 and the first check valve 122, and enters the rod cavity 112 of the hydraulic cylinder 110, so that the piston rod retracts, and the unloading operation of the screed plate under the acting force of the hydraulic oil is realized. In particular, the piston rod is connected to the screed, where unloading merely provides a fixed upward force, reducing the downward force of the screed on the paving material, and not necessarily lifting the screed (piston rod retraction). Meanwhile, the first check valve 122 and the second check valve 124 are controlled to be in a one-way conduction state, so that hydraulic oil can only flow into the rod cavity 112 from the third interface and cannot flow out of the rod cavity 112, the ironing plate is guaranteed not to fall back in the retracting process, and safety accidents are avoided.

Further, as shown in fig. 5, when the paver is in the fourth operating state, one of the first check valve 122 and the second check valve 124, which is connected in parallel with the first damper 126, is in a one-way conducting state, the other one is in a two-way conducting state, the first solenoid valve 130 is in the third operating position, and the inlet of the second solenoid valve 140 and the outlet of the second solenoid valve 140 are disconnected, so that the rod chamber 112 is communicated with the rodless chamber 114 and is communicated with the oil return port.

Specifically, the paver has a fourth operating state, at this time, one of the first check valve 122 and the second check valve 124, which is connected in parallel with the first damper 126, is in a one-way conduction state, the other one is in a two-way conduction state, and the first electromagnetic valve 130 is controlled to be in the third operating position at the same time, the inlet of the second electromagnetic valve 140 and the outlet of the second electromagnetic valve 140 are disconnected, so that the rod cavity 112 of the hydraulic cylinder 110 is communicated with the rod-free cavity 114, and simultaneously, the rod cavity is communicated with the oil return port of the hydraulic system 100, at this time, hydraulic oil does not have driving force effect, so that the ironing plate connected with the piston rod can fall freely under the action of gravity, so as to realize gravity descending operation of the paver, and through the setting of the damper, the falling process can be more stable, and accidents caused by too fast falling can be avoided.

Further, as shown in fig. 6, when the paver is in the fifth working state, the inlet of the second electromagnetic valve 140 is communicated with the outlet of the second electromagnetic valve 140, the first check valve 122 and the second check valve 124 are both in the one-way conduction state, and the first electromagnetic valve 130 is in the third working position, so that the rod chamber 112 is communicated with the pressure oil port, and the rodless chamber 114 is communicated with the oil return port.

Specifically, the paver has a fifth operating state, and at this time, the inlet of the second electromagnetic valve 140 is communicated with the outlet of the second electromagnetic valve 140, so that hydraulic oil can flow into the rod cavity 112 of the hydraulic cylinder 110 through the inlet of the second electromagnetic valve 140, thereby pushing the hydraulic piston, so that the piston rod retracts to drive the screed of the paver to return to the rod cavity 112, and thereby lifting operation of the screed of the paver is realized. Meanwhile, the first solenoid valve 130 is controlled to be in the third working position, so that the hydraulic oil flowing out of the rod chamber 112 can flow through the first solenoid valve 130 to the oil outlet, and oil circuit circulation is completed.

Further, as shown in fig. 1 to 6, the hydraulic system 100 further includes: the oil through valve block 180 comprises an oil inlet channel and an oil outlet channel; the oil inlet channel comprises a pressure oil port; the oil outlet channel comprises an oil return port.

Specifically, through the arrangement of the oil passing valve block 180, on one hand, the connection between the pressure oil source and the first electromagnetic valve 130 and the second electromagnetic valve 140 can be more convenient and stable, and on the other hand, the arrangement of an oil passing pipeline can be reduced, the risk of hydraulic oil leakage is reduced, and the stability of the hydraulic system 100 is improved.

The oil inlet channel of the oil passing valve block 180 includes a pressure oil port, hydraulic oil enters the oil inlet channel of the oil passing valve block 180 through the pressure oil port, and then enters the first electromagnetic valve 130, the second electromagnetic valve 140 and other components from the oil inlet channel, and further, the oil outlet channel of the oil passing valve block 180 includes an oil return port, so that hydraulic oil flowing out of the hydraulic system 100 is discharged to the oil tank from the oil return port.

In the present invention, the term "plurality" means two or more unless explicitly defined otherwise. The terms "mounted," "connected," "fixed," and the like are to be construed broadly, and for example, "connected" may be a fixed connection, a removable connection, or an integral connection; "coupled" may be direct or indirect through an intermediary. The specific meanings of the above terms in the present invention can be understood by those skilled in the art according to specific situations.

In the description herein, the description of the terms "one embodiment," "some embodiments," "specific embodiments," etc., means that a particular feature, structure, material, or characteristic described in connection with the embodiment or example is included in at least one embodiment or example of the invention. In this specification, the schematic representations of the terms used above do not necessarily refer to the same embodiment or example. Furthermore, the particular features, structures, materials, or characteristics described may be combined in any suitable manner in any one or more embodiments or examples.

The above is only a preferred embodiment of the present invention, and is not intended to limit the present invention, and various modifications and changes will occur to those skilled in the art. Any modification, equivalent replacement, or improvement made within the spirit and principle of the present invention should be included in the protection scope of the present invention.

Claims

1. A hydraulic system, comprising:

the hydraulic cylinder comprises a rod cavity and a rodless cavity;

a first check valve having a one-way communication state and a two-way communication state, a first end of the first check valve being in communication with the rod chamber;

a second check valve having a one-way communication state and a two-way communication state, a first end of the second check valve being in communication with a second end of the first check valve;

a first damper in parallel with the first or second check valve;

when the first check valve and the second check valve are both in a one-way conduction state, the conduction directions of the first check valve and the second check valve are both directed to the first check valve by the second check valve.

2. The hydraulic system of claim 1, further comprising:

the first electromagnetic valve comprises a first interface, a second interface, a third interface and a fourth interface, and the first electromagnetic valve comprises a first working position, a second working position and a third working position; in a first working position of the first electromagnetic valve, the first port is communicated with the third port, and the second port is communicated with the fourth port; in a second working position of the first electromagnetic valve, the first port is communicated with the fourth port, and the second port is communicated with the third port; in a third working position of the first electromagnetic valve, the fourth port and the third port are both communicated with the second port;

the first connector is communicated with the pressure oil port;

the second interface is communicated with the oil return port;

the third port is communicated with the second end of the second check valve;

the fourth interface is communicated with a rodless cavity of the hydraulic cylinder.

3. The hydraulic system of claim 2, further comprising:

and the inlet of the second electromagnetic valve is communicated with the pressure oil port, the outlet of the second electromagnetic valve is communicated with a communication pipeline which is connected with the rod cavity and the first end of the first check valve, and the inlet of the second electromagnetic valve is selectively communicated or disconnected with the outlet of the second electromagnetic valve.

4. The hydraulic system of claim 3, further comprising:

one end of the one-way valve is communicated with an outlet of the second electromagnetic valve, and a second end of the one-way valve is communicated with a communication pipeline which connects the rod cavity and the first end of the first check valve;

hydraulic oil in the communicating pipeline can be conducted in a one-way mode through the one-way valve along the direction from the second electromagnetic valve to the rod cavity;

and the second damper is arranged between the outlet of the second electromagnetic valve and the one-way valve.

5. The hydraulic system of any one of claims 2 to 4, further comprising a pressure relief valve;

the first end of the pressure reducing valve is communicated with the pressure oil port;

the second end of the pressure reducing valve is communicated with a first interface of the first electromagnetic valve;

and the third end of the pressure reducing valve is communicated with the oil return port.

6. The hydraulic system of claim 5, further comprising:

the pressure oil source is connected with the pressure oil port;

the oil tank is communicated with the oil return port.

7. The hydraulic system of any one of claims 1-4, wherein the first damper is a throttle valve.

8. A paving machine, comprising:

a screed plate; and

the hydraulic cylinder comprises a rod cavity and a rodless cavity;

a first damper in parallel with the first or second check valve;

wherein when the first check valve and the second check valve are both in a one-way communication state, the communication directions of the first check valve and the second check valve are both directed to the first check valve by the second check valve,

the screed plate is connected with a piston rod of the hydraulic cylinder.

9. The paving machine of claim 8, wherein: further comprising:

the first electromagnetic valve comprises a first interface, a second interface, a third interface and a fourth interface, and the first electromagnetic valve comprises a first working position, a second working position and a third working position; in a first working position of the first electromagnetic valve, the first port is communicated with the third port, and the second port is communicated with the fourth port; in a second working position of the first electromagnetic valve, the first port is communicated with the fourth port, and the second port is communicated with the third port; in a third working position of the first electromagnetic valve, the fourth port and the third port are both communicated with the second port; the first interface is communicated with the pressure oil port; the second interface is communicated with the oil return port; the third port is communicated with the second end of the second check valve; the fourth interface is communicated with a rodless cavity of the hydraulic cylinder;

an inlet of the second electromagnetic valve is communicated with the pressure oil port, an outlet of the second electromagnetic valve is communicated with a communication pipeline which connects the rod cavity and the first end of the first check valve, and the inlet of the second electromagnetic valve is selectively communicated or disconnected with the outlet of the second electromagnetic valve;

one end of the one-way valve is communicated with an outlet of the second electromagnetic valve, and a second end of the one-way valve is communicated with a communication pipeline which connects the rod cavity and the first end of the first check valve; hydraulic oil in the communicating pipeline can be conducted in a one-way mode through the one-way valve along the direction from the second electromagnetic valve to the rod cavity;

the second damper is arranged between the outlet of the second electromagnetic valve and the one-way valve;

a pressure reducing valve; the first end of the pressure reducing valve is communicated with the pressure oil port; the second end of the pressure reducing valve is communicated with a first interface of the first electromagnetic valve; the third end of the pressure reducing valve is communicated with the oil return port;

the pressure oil source is connected with the pressure oil port;

the oil tank is communicated with the oil return port;

the first damper is a throttle valve.

10. The paving machine of claim 9, wherein:

the paver comprises a first working state, a second working state, a third working state, a fourth working state and a fifth working state;

when the paver is in a first working state, the first check valve and the second check valve are both in a two-way conduction state, the first electromagnetic valve is in the third working position, and the inlet of the second electromagnetic valve is disconnected with the outlet of the second electromagnetic valve, so that the rod cavity is communicated with the rodless cavity, and the rod cavity and the rodless cavity are both communicated with the oil return port;

when the paver is in a second working state, one of the first check valve and the second check valve which is connected with the first damper in parallel is in a one-way conduction state, the other one of the first check valve and the second check valve is in a two-way conduction state, the first electromagnetic valve is in the second working position, and an inlet of the second electromagnetic valve is disconnected with an outlet of the second electromagnetic valve, so that the rodless cavity is communicated with the pressure oil port, and the rod cavity is communicated with the oil return port;

when the paver is in a third working state, the first check valve and the second check valve are both in a one-way conduction state, the first electromagnetic valve is in the first working position, and an inlet of the second electromagnetic valve is disconnected with an outlet of the second electromagnetic valve, so that the rodless cavity is communicated with the oil return port, and the rod cavity is communicated with the pressure oil port;

when the paver is in a fourth working state, one of the first check valve and the second check valve which is connected with the first damper in parallel is in a one-way conduction state, the other one of the first check valve and the second check valve is in a two-way conduction state, the first electromagnetic valve is in the third working position, and an inlet of the second electromagnetic valve is disconnected with an outlet of the second electromagnetic valve, so that the rod cavity is communicated with the rodless cavity and is communicated with the oil return port;

when the paver is in a fifth working state, the inlet of the second electromagnetic valve is communicated with the outlet of the second electromagnetic valve, the first check valve and the second check valve are both in a one-way conduction state, the first electromagnetic valve is in a third working position, so that the rod cavity is communicated with the pressure oil port, and the rodless cavity is communicated with the oil return port.