CN113719482B

CN113719482B - Hydraulic system and paver

Info

Publication number: CN113719482B
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: 2023-07-18
Anticipated expiration: 2041-08-30
Also published as: CN113719482A

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; a first check valve having a one-way conductive state and a two-way conductive state, a first end of the first check valve being in communication with the rod cavity; a second check valve having a one-way conductive state and a two-way conductive state, the first end of the second check valve being in communication with the 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, the two-way conduction and the damping conduction modes of the oil way of the hydraulic system, so that different conduction modes can be selected according to different requirements of working conditions of equipment connected with the hydraulic system, different operation requirements of the equipment can be met, the hydraulic system is simple and practical in structure, convenient in control process and convenient for control personnel to operate.

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 expressway construction in China brings higher requirements to the operation performance of the paver, and particularly the requirement on the flatness of paved roads is higher and higher. In order to improve the paving evenness, the screed is generally required to float in the paving process, namely, a rod cavity of the screed lifting cylinder is communicated with a rodless cavity.

In order to stabilize the speed of the screed as it descends, most pavers add damping to the lift cylinder. However, after the damping is added, hysteresis and resistance are caused by the damping when the screed is required to float, and the actual floating cannot be realized, so that starting indentation or arching is caused.

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

Disclosure of Invention

The present invention aims to solve or improve at least one of the technical problems existing in the prior art or related art.

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

A second aspect of the present invention proposes a paver.

In view of this, a first aspect of the present invention proposes a hydraulic system comprising: the hydraulic cylinder comprises a rod cavity and a rodless cavity; a first check valve having a one-way conductive state and a two-way conductive state, a first end of the first check valve being in communication with the rod cavity; a second check valve having a one-way conductive state and a two-way conductive state, the first end of the second check valve being in communication with the second end of the first check valve; a first damper connected in parallel with the first check valve or the second check valve; when the first check valve and the second check valve are 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 hydraulic system 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 mutually 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 both 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 both the first check valve and the second check valve are in a one-way conduction state, hydraulic oil in the hydraulic system can only flow from the second check valve to the first check valve, that is, hydraulic oil can only flow into the rod cavity of the hydraulic cylinder, and when both the first check valve and the second check valve are in a two-way conduction state, hydraulic oil can flow into the rod cavity and also flow out of the rod cavity. Through the arrangement of the first check valve and the second check valve which are connected in series, one-way conduction or two-way conduction of an oil way 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. By connecting the first damper in parallel with the first check valve or the second check valve, the first check valve or the second check valve connected in parallel with the first damper can be controlled to be in a one-way conduction state, and the other control valve can be controlled to be in a two-way conduction state, so that damping conduction of an oil way of the hydraulic system can be realized, that is, hydraulic oil can be realized to be in two-way damping conduction with the first damper through one of the first check valve and the second check valve.

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 in parallel with the first check valve or the second check valve is arranged at the same time, 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 in two-way conduction, the one-way conduction mode, the two-way conduction mode and the damping conduction mode of an oil way 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 are met.

The hydraulic system provided by the invention can also have the following additional technical characteristics:

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

In the technical scheme, the hydraulic system further comprises a first electromagnetic valve, the first electromagnetic valve is connected to a transmission pipeline used for transmitting hydraulic oil in the hydraulic system, specifically, the first electromagnetic valve can 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, 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 a second end of the second check valve, namely, hydraulic oil flows to the second check valve through the second interface and then flows to a rod cavity of the hydraulic cylinder, and accordingly, hydraulic oil flowing out of the rod cavity can flow into the first electromagnetic valve through the first check valve and the second check valve through the third interface; the fourth interface is communicated with the 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 the interior hydraulic oil flow path of hydraulic system, and then realize the different operating modes of piston rod, realized hydraulic system's multifunctionality.

Further, the first solenoid valve includes first working position, second working position and third working position, and when first solenoid valve was in first working 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 flowing through first interface, further flowing through second check valve and first check valve get into the pole chamber of pneumatic cylinder, so that the piston rod is retracted, thereby realized the unloading operation that the piston rod retracted pneumatic cylinder under the effort of hydraulic oil. It should be noted that during actual operation, the components to which the piston rod is connected require the piston rod to perform the work by unloading, i.e. the piston rod requires a force to retract the hydraulic cylinder, but the piston rod does not retract the hydraulic cylinder, in particular, in the case of a hydraulic system for a paver, the piston rod is connected to the screed, where the unloading only provides a fixed upward force, reducing the downward force of the screed on the paving material, and not lifting the screed (piston rod retraction). Meanwhile, the first check valve and the second check valve are controlled not to be electrified, so that hydraulic oil can only flow into the rod cavity from the third interface and cannot flow out of the rod cavity, the piston rod is prevented from extending out in the retracting process, and safety accidents are avoided.

When the first electromagnetic valve is in the second working position, the first interface is communicated with the fourth interface, the second interface is communicated with the third interface, so that hydraulic oil enters the first electromagnetic valve through the first interface, flows through the fourth interface and enters the rodless cavity of the hydraulic cylinder, so that acting force is applied to the hydraulic piston in the rodless cavity to push out the piston rod, loading operation that the piston rod stretches out of the hydraulic cylinder under the acting force of the hydraulic oil is achieved, and it is required that in the actual operation process, a part connected with the piston rod needs to operate in a loading mode, but the piston rod does not stretch out of the hydraulic cylinder, specifically, a hydraulic system is used for a paver, the piston rod is connected with the screed, downward acting force acts on the screed, but due to supporting action of paving materials, the piston rod can not act, and the downward acting force is fixed. Meanwhile, the first check valve is controlled to be electrified, the second check valve is controlled to be not electrified, so that hydraulic oil flowing out of the rod cavity flows to a third interface of the first electromagnetic valve through the first check valve and a first damper connected with the second check valve in parallel, and when the extension of the piston rod is realized, the accident caused by the fact that the extension of the piston rod is too fast is avoided through the damping action of the first damper. Further, hydraulic oil enters an oil return port flowing to the hydraulic system through the second interface, and circulation of the hydraulic oil is completed.

When the first electromagnetic valve is in the 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 the rodless cavity through the first check valve, the second check valve and the first electromagnetic valve, and meanwhile, the rod cavity can be communicated with an oil return port of the hydraulic system through the second interface of the first electromagnetic valve. And the first check valve and the second check valve are controlled to be in a two-way conduction state, so that hydraulic oil can freely enter and exit the rod cavity from the first check valve and the second check valve, the hydraulic oil can freely flow in the hydraulic system without being subjected to resistance action, and further a floating operation mode of the piston rod is realized, namely the piston rod can freely extend or retract under the action of external force, so that the responsiveness is improved.

In any of the above solutions, further, the hydraulic system further includes: 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 is the pole chamber through the valves that floats, specifically: the second solenoid valve is controlled to be electrified so that hydraulic oil can flow into the rod cavity of the hydraulic cylinder through the inlet of the second solenoid valve, thereby pushing the hydraulic piston to retract the piston rod 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 connected 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 controlling piston rod withdrawal pneumatic cylinder, need not to control first check valve and second check valve, can simplify hydraulic system's control process in relevant operational environment, promote the convenience.

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

In this technical scheme, hydraulic system still includes the check valve that sets up between the export of second solenoid valve and the pole chamber to, hydraulic oil can be followed the second solenoid valve and directed one-way conduction of pole chamber. Through the setting of check valve, can make the in-process that control piston rod was retracted through the second solenoid valve, avoid hydraulic oil backward flow to avoid the piston rod to stretch out suddenly, the security of further improvement hydraulic system.

In any of the above solutions, further, the hydraulic system further includes: 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 too fast and lead to the too fast of piston rod withdrawal's speed, further promoted hydraulic system's security.

In any of the above 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 of relief pressure valve is linked together with the pressure hydraulic fluid port, and the second end of relief pressure valve is linked together with the first interface of first solenoid valve, and the third end of relief pressure valve is linked together with the oil return mouth, that is, before hydraulic oil passes through the first interface of first solenoid valve and gets into first solenoid valve, can first pass through the relief pressure valve to make hydraulic oil get into first solenoid valve before the pressure of hydraulic oil first adjust through the relief pressure valve, thereby the size of the effort of loading and uninstallation is controlled accurately.

In any of the above 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.

According to the technical scheme, through the arrangement of the pressure oil source, driving force can be provided for hydraulic oil in the hydraulic system, so that the hydraulic oil in the oil tank is driven to the hydraulic system from the pressure oil port, circulation of the hydraulic oil is achieved, further, the oil return port is communicated with the oil tank, and the hydraulic oil after the circulation of the hydraulic system can flow into the oil tank from the oil return port.

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

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

The invention provides a paver, which comprises a hydraulic cylinder, wherein the hydraulic cylinder comprises a rod cavity, a rodless cavity, a first check valve and a second check valve which are mutually 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 both 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 first check valve and the second check valve are both oriented to the first check valve in the same direction. That is, when both the first check valve and the second check valve are in a one-way conduction state, hydraulic oil in the hydraulic system can only flow from the second check valve to the first check valve, that is, hydraulic oil can only flow into the rod cavity of the hydraulic cylinder, and when both the first check valve and the second check valve are in a two-way conduction state, hydraulic oil can flow into the rod cavity and also flow out of the rod cavity. Through the arrangement of the first check valve and the second check valve which are connected in series, one-way conduction or two-way conduction of an oil way 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. By connecting the first damper in parallel with the first check valve or the second check valve, the first check valve or the second check valve connected in parallel with the first damper can be controlled to be in a one-way conduction state, and the other control valve can be controlled to be in a two-way conduction state, so that damping conduction of an oil way of the hydraulic system can be realized, that is, hydraulic oil can be realized to be in two-way damping conduction with the first damper through one of the first check valve and the second check valve. Further, the paver further 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 the piston rod of pneumatic 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 in parallel with the first check valve or the second check valve is arranged at the same time, 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 in 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 plate of the paver can be controlled to carry out floating operation, lifting operation and other operation modes so as to meet the operation requirements of the paver.

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

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, the first electromagnetic valve can 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, 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 a second end of the second check valve, namely, hydraulic oil flows to the second check valve through the second interface and then flows to a rod cavity of the hydraulic cylinder, and accordingly, hydraulic oil flowing out of the rod cavity can flow into the first electromagnetic valve through the first check valve and the second check valve through the third interface; the fourth interface is communicated with the 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 working position of first solenoid valve to realize the connection between the different interfaces of first solenoid valve, and then adjust the change of the interior hydraulic oil flow path of hydraulic system, and then realize the different mode of piston rod, realized the multifunctionality when paver screed is operated.

Further, the first solenoid valve includes first working position, second working position and third working position, and when first solenoid valve was in first working 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 flowing through first interface, further flowing through second check valve and first check valve get into the pole chamber of pneumatic cylinder, so that the piston rod is retracted, thereby realized the unloading operation that the piston rod retracted pneumatic cylinder under the effort of hydraulic oil. It should be noted that during actual operation, the component to which the piston rod is connected requires the piston rod to perform the operation by unloading, i.e. the piston rod requires a force to retract the hydraulic cylinder, but the piston rod does not retract the hydraulic cylinder. Meanwhile, the first check valve and the second check valve are controlled not to be electrified, so that hydraulic oil can only flow into the rod cavity from the third interface and cannot flow out of the rod cavity, the piston rod is prevented from extending out in the retracting process, and safety accidents are avoided.

When the first electromagnetic valve is in 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, flows through the fourth interface and enters the rodless cavity of the hydraulic cylinder, so that acting force is applied to the hydraulic piston in the rodless cavity, the piston rod is pushed out, and loading operation that the piston rod extends out of the hydraulic cylinder under the acting force of the hydraulic oil is realized. In the actual operation, the member to which the piston rod is connected requires the piston rod to perform the operation by loading, but the piston rod does not extend out of the hydraulic cylinder. Meanwhile, the first check valve is controlled to be electrified, the second check valve is controlled to be not electrified, so that hydraulic oil flowing out of the rod cavity flows to a third interface of the first electromagnetic valve through the first check valve and a first damper connected with the second check valve in parallel, and when the extension of the piston rod is realized, the accident caused by the fact that the extension of the piston rod is too fast is avoided through the damping action of the first damper. Further, hydraulic oil enters an oil return port flowing to the hydraulic system through the second interface, and circulation of the hydraulic oil is completed.

Further, the paver further includes: 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 is the pole chamber through the valves that floats, specifically: the second solenoid valve is controlled to be electrified so that hydraulic oil can flow into the rod cavity of the hydraulic cylinder through the inlet of the second solenoid valve, thereby pushing the hydraulic piston to retract the piston rod 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 connected 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 further includes: the one-way valve is arranged on a communicating pipeline between the outlet of the second electromagnetic valve and the rod cavity; the hydraulic oil can be conducted unidirectionally along the direction from the second electromagnetic valve to the rod cavity through the one-way valve.

Specifically, the hydraulic system further includes a check valve disposed between the outlet of the second solenoid valve and the rod chamber, and hydraulic oil can be conducted in one direction from the second solenoid valve to the rod chamber. Through the setting of check valve, can make the in-process that control piston rod was retracted through the second solenoid valve, avoid hydraulic oil backward flow to avoid the piston rod to stretch out suddenly, the security of further improvement hydraulic system.

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

Specifically, between the outlet of the second electromagnetic valve and the one-way valve, a second damper can be further arranged, through the arrangement of the second damper, the movable damping effect can be achieved on the flow of hydraulic oil, the situation that the piston rod retracts too fast due to too fast flow of the hydraulic oil is avoided, and the safety of a hydraulic system is further improved.

Further, the paver 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.

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

Further, the paver further 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 of the above technical solutions, further, the paver includes 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 in a two-way conduction state, the first electromagnetic valve is in a third working position, the inlet of the second electromagnetic valve and the outlet of the second electromagnetic valve are disconnected, so that the rod cavity is communicated with the rodless cavity, and the rod cavity and the rodless cavity are 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 the rodless cavity through the first check valve, the second check valve and the first electromagnetic valve, and meanwhile, the rod cavity of the hydraulic cylinder can be communicated with an oil return port of the hydraulic system through the second interface of the first electromagnetic valve. And the first check valve and the second check valve are controlled to be in a power-on state, so that hydraulic oil can freely enter and exit the rod cavity from the first check valve and the second check valve, the hydraulic oil can freely flow in the hydraulic system without being subjected to resistance action, and further a floating operation mode of the screed plate is realized, namely, the piston rod can freely extend or retract under the action of external force, so that the responsiveness is improved.

Further, when the paver is in the 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 the first working position, the inlet of the second electromagnetic valve and the outlet of the second electromagnetic valve are disconnected, 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 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, flows through the fourth interface and enters the rodless cavity of the hydraulic cylinder, so that acting force is applied to the hydraulic piston in the rodless cavity to push out the piston rod, loading operation of the screed plate under the acting force of the hydraulic oil is achieved, and it is noted that the piston rod is connected with the screed plate, the piston rod has downward acting force acting on the screed plate, but due to supporting action of paving materials, the piston rod may not act, but the downward acting force is fixed. 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 controlled to be in a two-way conduction state, and the inlet of the second electromagnetic valve and the outlet of the second electromagnetic valve are disconnected, 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, loading of the screed is realized, and meanwhile, the accident caused by too fast extension of the screed is avoided through the damping action of the first damper. Further, hydraulic oil enters an oil return port flowing to the hydraulic system through the second interface, and circulation of the hydraulic oil is completed.

Further, when the paver is in the third working state, the first check valve and the second check valve are in a one-way conduction state, the first electromagnetic valve is in the first working position, the inlet of the second electromagnetic valve and the outlet of the second electromagnetic valve are disconnected, 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 in the first working position, the first interface is communicated with the third interface, the second interface is communicated with the fourth interface, the inlet of the second electromagnetic valve is disconnected from the outlet of the second electromagnetic valve, so that hydraulic oil enters from the pressure oil port of the hydraulic system, flows through the third interface of the first interface, further flows through the second check valve and the first check valve to enter the rod cavity of the hydraulic cylinder, so that the piston rod is retracted, and therefore the unloading operation of the screed plate under the acting force of the hydraulic oil is realized. Simultaneously, control first check valve and second check valve all are in one-way conduction state for hydraulic oil can only flow in from the third interface and have the pole intracavity, can't flow out from having the pole intracavity, has guaranteed that the in-process that the screed was retracted can not fall back, avoids the incident.

Further, when the paver is in the fourth working state, one of the first check valve and the second check valve, which is connected in parallel with the first damper, 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 the inlet of the second electromagnetic valve and the outlet of the second electromagnetic valve are disconnected, so that the rod cavity is communicated with the rodless cavity and is communicated with the oil return port.

Specifically, the paver has the fourth operating condition, and at this moment, one of first check valve and second check valve and first attenuator parallelly connected is in one-way conducting state, and another one is in two-way conducting state, and the first solenoid valve of simultaneous control is in the third working position, and the import of second solenoid valve and the export disconnection of second solenoid valve, and then the pole chamber that makes the pneumatic cylinder is linked together with the rodless chamber, simultaneously again be linked together with hydraulic system's oil return port, at this moment, hydraulic oil does not have the driving force effect, can make the screed that is connected with the piston rod can freely fall under the effect of gravity to realize the gravity decline operation of paver, and, through the setting of attenuator, can make the whereabouts process more steady, avoid whereabouts too soon to cause the accident.

Further, when the paver is in the 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, and the first electromagnetic valve is in the 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 working state, at this time, the inlet of the second electromagnetic valve is communicated with the outlet of the second electromagnetic valve, so that 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, so that the piston rod contracts to drive the screed of the paver to return to the rod cavity, and lifting operation of the screed of the paver is realized. 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 to the oil outlet through the first electromagnetic valve, and oil circuit circulation is completed.

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

Drawings

The foregoing and/or additional aspects and advantages of the invention will become apparent and may be better understood from the following description of embodiments taken in conjunction with the accompanying drawings in which:

FIG. 1 shows a schematic diagram of a hydraulic system according to an embodiment of the present invention;

FIG. 2 shows a schematic diagram of the hydraulic system of FIG. 1 in a floating mode of operation;

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

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

FIG. 5 shows a schematic view of the hydraulic system of FIG. 1 in a lift mode of operation;

FIG. 6 shows a schematic view of the hydraulic system of FIG. 1 in a gravity descent mode;

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

100 hydraulic system, 110 hydraulic cylinder, 112 with rod chamber, 114 without rod 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 relief valve, 180 oil-through valve block.

Detailed Description

In order that the above-recited objects, features and advantages of the present invention will be more clearly understood, a more particular description of the invention will be rendered by reference to the appended drawings and appended detailed description. It should be noted that, in the case of no conflict, the embodiments of the present application and the features in the embodiments may be combined with each other.

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 described herein, and therefore the scope of the present invention is not limited to the specific embodiments disclosed below.

A hydraulic system and a paver according to some embodiments of the invention are described below with reference to fig. 1 to 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 conductive state and a two-way conductive 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 conductive state and a two-way conductive state, a first end of the second check valve 124 being in communication 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 unidirectional conductive state, the conductive 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 mutually 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 comprise a one-way conduction state and a two-way conduction state, in particular, when the first check valve 122 and the second check valve 124 are 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 in the same direction. That is, when both the first check valve 122 and the second check valve 124 are in the unidirectional conductive state, hydraulic oil in the hydraulic system 100 can only flow from the second check valve 124 to the first check valve 122, i.e., hydraulic oil can only flow into the rod chamber 112 of the hydraulic cylinder 110, and when both the first check valve 122 and the second check valve 124 are in the bidirectional conductive state, hydraulic oil can flow into the rod chamber 112 and also flow out of the rod chamber 112. By providing the first check valve 122 and the second check valve 124 in series, one-way communication or two-way communication of the oil passage of the hydraulic system 100 can be achieved. 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 conduction state while the other control valve is controlled to be in a two-way conduction state, so that damping conduction of the oil passage of the hydraulic system 100 can be achieved, that is, hydraulic oil is brought into two-way damping conduction with the first damper 126 through one of the first check valve 122 and the second check valve 124.

According to the hydraulic system 100 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 states 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 in two-way conduction, so that 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, the selection of different conduction modes can be carried out according to different equipment connected with the hydraulic system 100, the selection of different conduction modes can be carried out according to different requirements of the working conditions of the equipment connected with the hydraulic system 100, the different operation requirements of the equipment can be met, the structure is simple and practical, the control process is convenient, and the operation of control personnel is convenient.

In the above embodiment, further, as shown in fig. 1 to 4, the hydraulic system 100 further includes: a first solenoid valve 130, the first solenoid valve 130 comprising a first interface, a second interface, a third interface, and a fourth interface, the first solenoid valve 130 comprising a first operating position, a second operating position, and a third operating position; in the first working position of the first electromagnetic valve 130, the first interface is communicated with the third interface, and the second interface is communicated with the fourth interface; in the second working position of the first electromagnetic valve 130, the first interface is communicated with the fourth interface, and the second interface is communicated with the third interface; in the third working position of the first electromagnetic valve 130, the fourth interface and the third interface are communicated with the second interface; 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, where the first solenoid valve 130 is connected to a transmission line in the hydraulic system 100 for transmitting hydraulic oil, 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, where the first port is in communication with a pressure port of the hydraulic system 100, that is, hydraulic oil enters the hydraulic system 100 through the first port, the second port is in communication with an oil return port of the hydraulic system 100, that is, hydraulic oil exits the hydraulic system 100 through the second port, and the third port is in communication with a second end of the second check valve 124, that is, hydraulic oil may flow through the second port to the second check valve 124, and thus to the rod chamber 112 of the hydraulic cylinder 110, and accordingly, hydraulic oil flowing out of the rod chamber 112 may flow into the first solenoid valve 130 through the first check valve 122 and the second check valve 124 through the third port; the fourth port is in communication with the rodless chamber 114 of the hydraulic cylinder 110, i.e., hydraulic oil entering the first solenoid valve 130 may flow to the rodless chamber 114 through the fourth port, and hydraulic oil exiting the rodless chamber 114 may also flow to 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 the hydraulic oil flow path in the hydraulic system 100, and then realize the different mode of operation of piston rod, realized the multifunctionality of hydraulic system 100.

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 interface is communicated with the third interface, and the second interface is communicated with the fourth interface, so that hydraulic oil enters from the pressure oil port of the hydraulic system 100, flows through the third interface of the first interface, further flows through the second check valve 124 and the first check valve 122 to enter the rod cavity 112 of the hydraulic cylinder 110, so that the piston rod is retracted, and the 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 during actual operation, the components to which the piston rod is connected require the piston rod to perform the operation by unloading, i.e. the piston rod requires a force to retract the hydraulic cylinder, but the piston rod does not retract the hydraulic cylinder, in particular, in the case of the hydraulic system 100 for a paver, the piston rod is connected to the screed, where unloading only provides a fixed upward force, reducing the downward force of the screed on the paving material, rather than lifting the screed (piston rod retraction). Meanwhile, the first check valve 122 and the second check valve 124 are controlled not to be electrified, 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 prevented from extending in the retracting process, and safety accidents are avoided.

Specifically, as shown in fig. 3, when the first solenoid valve 130 is in 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 solenoid valve 130 through the first interface, flows through the fourth interface and enters the rodless cavity 114 of the hydraulic cylinder 110, so as to apply a force to the hydraulic piston in the rodless cavity 114, push out the piston rod, and realize a loading operation that the piston rod extends out of the hydraulic cylinder 110 under the force of the hydraulic oil. It should be noted that, during actual operation, the component to which the piston rod is connected requires the piston rod to perform the operation by means of loading, but the piston rod does not extend out of the hydraulic cylinder, specifically, in the example of the hydraulic system 100 for the paver, the piston rod is connected to the screed, the piston rod has a downward force acting on the screed, but the piston rod may not act due to the supporting effect of the paving material, but the downward force is fixed. Meanwhile, the first check valve 122 is controlled to be electrified, the second check valve 124 is controlled to be unpowered, so that hydraulic oil flowing out of the rod cavity 112 flows to the third interface of the first electromagnetic 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 extension of the piston rod is realized, the accident caused by the fact that the extension of the piston rod is too fast is avoided through the damping action of the first damper 126. Further, the hydraulic oil flows into 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 communicates with the third port, while the second port communicates with the fourth port, so that the rod chamber 112 of the hydraulic cylinder 110 communicates with the rodless chamber 114 through the first check valve 122, the second check valve 124, and the first solenoid valve 130, while also communicating 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 a two-way conduction state, so that hydraulic oil can freely enter and exit 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 action, and further a floating operation mode of the piston rod is realized, namely, the piston rod can freely extend or retract under the action of external force, so that the responsiveness is improved.

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

In this embodiment, the hydraulic system 100 may also be provided with a second solenoid valve 140, the inlet of the second solenoid valve 140 communicating with the oil inlet and the outlet communicating with the rodless chamber 114 of the hydraulic cylinder 110. By the provision of the second solenoid valve 140, hydraulic oil can be made to directly enter the rod chamber 112 without passing through the float valve group, specifically: the second solenoid valve 140 is controlled to be energized such 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 such that the piston rod is retracted into the rod chamber 112. At the same time, the hydraulic oil flowing out of the rod chamber 112 can 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 the inlet and outlet of the second solenoid valve 140 are disconnected when the second solenoid valve 140 is not energized, and hydraulic oil is not circulated through the second solenoid valve 140.

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

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

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 unidirectionally in the direction from the second solenoid valve 140 to the rod chamber 112. By the arrangement of the check valve 150, the hydraulic oil is prevented from flowing back in the process of controlling the retraction of the piston rod by the second electromagnetic valve 140, thereby preventing the piston rod from suddenly extending, and further improving 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: the second damper 160 is 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 by setting the second damper 160, a movement damping effect may be played on the flow of hydraulic oil, so that the hydraulic oil is prevented from flowing too fast to cause the retraction speed of the piston rod to be too fast, 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: a pressure reducing valve 170; the first end of the pressure reducing valve 170 is communicated with the oil inlet pressure oil port; a second end of the pressure relief valve 170 communicates with a first port of the first solenoid valve 130; a third end of the relief valve 170 communicates with the 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 connected to the pressure port, a second end of the pressure reducing valve 170 is connected to the first port of the first solenoid valve 130, and a third end of the pressure reducing valve 170 is connected to the oil return port, that is, before hydraulic oil enters the first solenoid valve 130 through the first port of the first solenoid valve 130, the pressure of the hydraulic oil is first adjusted through the pressure reducing valve 170, so that the magnitude of the loading and unloading force is accurately controlled.

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, by setting 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 from the pressure oil port to the hydraulic system 100, so as to realize circulation of the hydraulic oil, further, the oil return port is communicated with the oil tank, and the hydraulic oil after the circulation of 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 conductive state and a two-way conductive 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 conductive state and a two-way conductive state, a first end of the second check valve 124 being in communication 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 both the first check valve 122 and the second check valve 124 are in the unidirectional conductive state, the conductive 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 with 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 mutually 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 respectively comprise a one-way conduction state and a two-way conduction state, in particular, when the first check valve 122 and the second check valve 124 respectively are in the one-way conduction state, the first check valve 122 and the second check valve 124 respectively point to the first check valve 122 in the same direction. That is, when both the first check valve 122 and the second check valve 124 are in the unidirectional conductive state, hydraulic oil in the hydraulic system 100 can only flow from the second check valve 124 to the first check valve 122, i.e., hydraulic oil can only flow into the rod chamber 112 of the hydraulic cylinder 110, and when both the first check valve 122 and the second check valve 124 are in the bidirectional conductive state, hydraulic oil can flow into the rod chamber 112 and also flow out of the rod chamber 112. By providing the first check valve 122 and the second check valve 124 in series, one-way communication or two-way communication of the oil passage of the hydraulic system 100 can be achieved. 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 conduction state while the other control valve is controlled to be in a two-way conduction state, so that damping conduction of the oil passage of the hydraulic system 100 can be achieved, that is, hydraulic oil is brought into 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 further 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 with 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 in two-way conduction, 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 plate of the paver can be controlled to carry out floating operation, lifting operation and other operation modes so as to meet the operation requirement of the paver.

In the above embodiment, further, as shown in fig. 1, the paver further includes: a first solenoid valve 130, the first solenoid valve 130 comprising a first interface, a second interface, a third interface, and a fourth interface, the first solenoid valve 130 comprising a first operating position, a second operating position, and a third operating position; in the first working position of the first electromagnetic valve 130, the first interface is communicated with the third interface, and the second interface is communicated with the fourth interface; in the second working position of the first electromagnetic valve 130, the first interface is communicated with the fourth interface, and the second interface is communicated with the third interface; in the third working position of the first electromagnetic valve 130, the fourth interface and the third interface are communicated with the second interface; 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 electromagnetic valve 130, the first electromagnetic valve 130 is connected to a transmission pipeline in the hydraulic system 100 for transmitting hydraulic oil, in particular, the first electromagnetic valve 130 may comprise a Y-shaped three-position four-way valve, the first electromagnetic valve 130 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 100, that is, hydraulic oil enters the hydraulic system 100 through the first interface, the second interface is communicated with an oil return port of the hydraulic system 100, that is, hydraulic oil flows out of the hydraulic system 100 through the second interface, that is, the third interface is communicated with a second end of the second check valve 124, that is, hydraulic oil flows to the second check valve 124 through the second interface, and then to the rod cavity 112 of the hydraulic cylinder 110, and accordingly, hydraulic oil flowing out of the rod cavity 112 may flow into the first electromagnetic valve 130 through the first check valve 122 and the second check valve 124 through the third interface; the fourth port is in communication with the rodless chamber 114 of the hydraulic cylinder 110, i.e., hydraulic oil entering the first solenoid valve 130 may flow to the rodless chamber 114 through the fourth port, and hydraulic oil exiting the rodless chamber 114 may also flow to the first solenoid valve 130 through the fourth port.

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

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, the second port is communicated with the fourth port, so that hydraulic oil enters from a 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 to enter the rod cavity 112 of the hydraulic cylinder 110, so that the piston rod is retracted, and thus, the 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 during actual operation, the component to which the piston rod is connected requires the piston rod to perform the operation by unloading, i.e. the piston rod requires 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 electrified, 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 prevented from extending in the retracting process, and safety accidents are avoided.

Specifically, as shown in fig. 3, when the first solenoid valve 130 is in 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 solenoid valve 130 through the first interface, flows through the fourth interface and enters the rodless cavity 114 of the hydraulic cylinder 110, so as to apply a force to the hydraulic piston in the rodless cavity 114, push out the piston rod, and realize a loading operation that the piston rod extends out of the hydraulic cylinder 110 under the force of the hydraulic oil. In the actual operation, the member to which the piston rod is connected requires the piston rod to perform the operation by loading, but the piston rod does not extend out of the hydraulic cylinder. Meanwhile, the first check valve 122 is controlled to be electrified, the second check valve 124 is controlled to be unpowered, so that hydraulic oil flowing out of the rod cavity 112 flows to the third interface of the first electromagnetic 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 extension of the piston rod is realized, the accident caused by the fact that the extension of the piston rod is too fast is avoided through the damping action of the first damper 126. Further, the hydraulic oil flows into 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 communicates with the third port, while the second port communicates with the fourth port, such that the rod chamber 112 of the hydraulic cylinder 110 communicates with the rodless chamber 114 through the first check valve 122, the second check valve 124, and the first solenoid valve 130, while also communicating 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 a two-way conduction state, so that hydraulic oil can freely enter and exit 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 action, and further a floating operation mode of the piston rod is realized, namely, the piston rod can freely extend or retract under the action of external force, so that the responsiveness is improved.

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

Specifically, the hydraulic system 100 may further be provided with a second solenoid valve 140, wherein an inlet of the second solenoid valve 140 is communicated with the oil inlet, and an outlet of the second solenoid valve is communicated with the rodless chamber 114 of the hydraulic cylinder 110. By the provision of the second solenoid valve 140, hydraulic oil can be made to directly enter the rod chamber 112 without passing through the float valve group, specifically: the second solenoid valve 140 is controlled to be energized such 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 such that the piston rod is retracted into the rod chamber 112. At the same time, the hydraulic oil flowing out of the rod chamber 112 can 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 the inlet and outlet of the second solenoid valve 140 are disconnected when the second solenoid valve 140 is not energized, and 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 provided on a communication pipe between the outlet of the second solenoid valve 140 and the rod chamber 112; hydraulic oil can be unidirectionally conducted in the direction from the second solenoid valve 140 to the rod chamber 112 via the check valve 150.

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 unidirectionally in the direction from the second solenoid valve 140 to the rod chamber 112. By the arrangement of the check valve 150, the hydraulic oil is prevented from flowing back in the process of controlling the retraction of the piston rod by the second electromagnetic valve 140, thereby preventing the piston rod from suddenly extending, and further improving the safety of the hydraulic system 100.

Further, as shown in fig. 1, the hydraulic system 100 further includes: the second damper 160 is 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 by setting the second damper 160, a moving damping effect may be achieved on the flow of hydraulic oil, so that the too fast speed of retraction of the piston rod caused by too fast flow of hydraulic oil is avoided, and the safety of the hydraulic system 100 is further improved.

Further, as shown in fig. 1, the hydraulic system 100 further includes: a pressure reducing valve 170; the first end of the pressure reducing valve 170 is communicated with the oil inlet pressure oil port; a second end of the pressure relief valve 170 communicates with a first port of the first solenoid valve 130; a third end of the relief valve 170 communicates with the 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 oil port, a second end of the pressure reducing valve 170 is communicated with the first interface of the first solenoid 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 solenoid valve 130 through the first interface of the first solenoid valve 130, the pressure of the hydraulic oil is first adjusted through the pressure reducing valve 170, so that the magnitude of the acting force of loading and unloading is accurately controlled.

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 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 from the pressure oil port to the hydraulic system 100, circulation of the hydraulic oil is realized, furthermore, the oil return port is communicated with the oil tank, and the hydraulic oil after the circulation of 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 condition 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 via the first check valve 122, the second check valve 124, and the first solenoid valve 130, and is also in communication with the return port of the hydraulic system 100 via 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 power-on state, so that the hydraulic oil can freely enter and exit 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 action, and further, the floating operation mode of the screed plate is realized, namely, the piston rod can freely extend or retract under the action of external force, so that the responsiveness is improved.

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 connected in parallel with the first damper 126 is in a unidirectional conduction state, the other is in a bidirectional conduction state, the first electromagnetic valve 130 is in the first working position, 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 pressure oil port, and the rod cavity 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 in 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 130 through the first interface, flows through the fourth interface and enters the rodless cavity 114 of the hydraulic cylinder 110, so as to apply acting force to the hydraulic piston in the rodless cavity 114, push out the piston rod, and realize loading operation of the screed plate under the acting force of the hydraulic oil. In particular, the piston rod is connected to the screed with a downward force acting on the screed, but the piston rod may not be active due to the supporting effect of the paving material, but this downward force is fixed. Meanwhile, one of the first check valve 122 and the second check valve 124 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 hydraulic oil flowing out of the rod cavity 112 flows to the third interface 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, loading of the screed is realized, and meanwhile, the accident caused by too fast extension of the screed is avoided through the damping action of the first damper 126. Further, the hydraulic oil flows into 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 the unidirectional conduction state, the first electromagnetic valve 130 is in the first working position, 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, in which the first solenoid 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 solenoid valve 140 and the outlet of the second solenoid valve 140 are disconnected, 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 is retracted, 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 the unloading is only to provide a fixed upward force, reducing the downward force of the screed on the paving material, and not necessarily lifting the screed (piston rod retracted). 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 situation that the ironing plate cannot fall back in the retracting process is ensured, and safety accidents are avoided.

Further, as shown in fig. 5, when the paving machine is in the fourth operating state, one of the first check valve 122 and the second check valve 124 connected in parallel with the first damper 126 is in the unidirectional conductive state, the other is in the bidirectional conductive 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-shaped 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 connected in parallel with the first damper 126 is in a unidirectional conduction state, the other one is in a bidirectional conduction state, and meanwhile, the first solenoid valve 130 is controlled to be in a third operating position, the inlet of the second solenoid valve 140 and the outlet of the second solenoid valve 140 are disconnected, so that the rod cavity 112 of the hydraulic cylinder 110 is communicated with the rodless cavity 114 and is also communicated with the oil return port of the hydraulic system 100, at this time, hydraulic oil has no driving force effect, so that a screed plate connected with a piston rod can freely fall under the action of gravity to realize the gravity falling operation of the paver, and through the arrangement of the damper, the falling process can be more stable, and accidents caused by too fast falling are 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 a one-way conduction state, and the first electromagnetic valve 130 is in the third working position, so that the rod cavity 112 is communicated with the pressure oil port, and the rodless cavity 114 is communicated with the oil return port.

Specifically, the paver has a fifth working state, in which 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 contracts to drive the screed of the paver to return to the rod cavity 112, and the lifting operation of the screed of the paver is realized. Meanwhile, the first electromagnetic valve 130 is controlled to be in the third working position, so that hydraulic oil flowing out of the rod cavity 112 can flow to the oil outlet through the first electromagnetic valve 130, and oil circuit circulation is completed.

Further, as shown in fig. 1 to 6, the hydraulic system 100 further includes: an oil passing valve block 180 including an oil inlet passage and an oil outlet passage; 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 the oil passing pipeline can be reduced, the risk of leakage of hydraulic oil is reduced, and the stability of the hydraulic system 100 is improved.

The oil inlet channel of the oil passing valve block 180 comprises 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 components such as the first electromagnetic valve 130, the second electromagnetic valve 140 and the like from the oil inlet channel, and further, the oil outlet channel of the oil passing valve block 180 comprises an oil return port, so that hydraulic oil flowing out of the hydraulic system 100 is discharged to an 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," "secured," and the like are to be construed broadly, and may be, for example, fixedly connected, detachably connected, or integrally connected; "coupled" may be directly coupled or indirectly coupled through intermediaries. The specific meaning of the above terms in the present invention can be understood by those of ordinary skill in the art according to the specific circumstances.

In the description of the present specification, the terms "one embodiment," "some embodiments," "particular embodiments," and the like, mean 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 present invention. In this specification, schematic representations of the above terms 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, but various modifications and variations can be made to the present invention by those skilled in the art. Any modification, equivalent replacement, improvement, etc. 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 conductive state and a two-way conductive state, a first end of the first check valve in communication with the rod cavity;

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

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

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

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 the rodless cavity of the hydraulic cylinder;

the first damper is a throttle valve.

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

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 communicating 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 and the outlet of the second electromagnetic valve can be selectively communicated or disconnected.

4. A hydraulic system according to claim 3, further comprising:

one end of the one-way valve is communicated with the outlet of the second electromagnetic valve, and the second end of the one-way valve is communicated with a communicating pipe connecting the rod cavity and the first end of the first check valve;

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

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 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 the 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. A paver, characterized by comprising:

a screed plate; and

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

wherein when the first check valve and the second check valve are 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 screed is connected with a piston rod of the hydraulic cylinder.

8. Paver according to claim 7, characterized in that: further comprises:

the first electromagnetic valve comprises a first interface, a second interface, a third interface and a fourth interface, and comprises a first working position, a second working position and a third working position; in a first working position of a first electromagnetic valve, the first interface is communicated with the third interface, and the second interface is communicated with the fourth interface; in 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; in a third working position of the first electromagnetic valve, the fourth interface and the third interface are communicated with the second interface; 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 the rodless cavity of the hydraulic cylinder;

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 communicating pipe which is used for connecting the rod cavity with the first end of the first check valve, and the inlet of the second electromagnetic valve and the outlet of the second electromagnetic valve can be selectively communicated or disconnected;

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

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 the 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.

9. Paver according to claim 8, characterized in that:

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 in a two-way conduction state, the first electromagnetic valve is in the third working position, the inlet of the second electromagnetic valve and the outlet of the second electromagnetic valve are disconnected, so that the rod cavity is communicated with the rodless cavity, and the rod cavity and the rodless cavity are 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 in parallel with the first damper, 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, the inlet of the second electromagnetic valve and the outlet of the second electromagnetic valve are disconnected, 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 in a one-way conduction state, the first electromagnetic valve is in the first working position, the inlet of the second electromagnetic valve and the outlet of the second electromagnetic valve are disconnected, 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 in parallel with the first damper, 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 the inlet of the second electromagnetic valve and the outlet of the second electromagnetic valve are disconnected, 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 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.