Paver material conveying hydraulic system and paver

Abstract

The utility model relates to the technical field of paver, specifically disclose a kind of paver conveying hydraulic system and paver, paver conveying hydraulic system includes first conveying motor, first hydraulic pump, first conveying control valve and first cold start valve, the input end of first hydraulic pump is communicated with oil tank, first conveying control valve can make first hydraulic pump, first conveying motor and oil tank constitute open circuit, or make first hydraulic pump, first conveying motor disconnect, and both ends of first conveying motor are communicated with oil tank, first cold start valve has first oil inlet and first oil outlet, first oil outlet is connected oil tank by oil return oil circuit, first cold start valve can make first oil inlet and first oil outlet communicate or disconnect, when starting in low temperature operating condition, by first cold start valve can make first oil inlet and first oil outlet communicate, can make engine can be smoothly started, avoid engine damage.

Description

Technical Field

[0001] This utility model relates to the field of paver technology, and in particular to a paver material conveying hydraulic system and a paver. Background Technology

[0002] A paver is a construction device mainly used for paving various materials for the base and surface layers of highways. It consists of various systems working together to complete the paving operation. Most existing fully hydraulically driven pavers use hydraulic drives, including hydraulic systems for power generation, travel, material conveying, screed extension, auger distribution, compaction, vibration, and auxiliary hydraulic systems.

[0003] In the case of the paver's hydraulic conveying system, as disclosed in the existing patent application number CN201922346812.2, two metering pumps directly draw oil from the oil tank. These pumps then deliver hydraulic oil to two proportional solenoid valves. When the valves are open, hydraulic oil can flow to two conveying motors. When the valves are closed, the metering pumps are disconnected from the conveying motors, putting them in standby mode. However, during low-temperature starting conditions (e.g., winter), the high viscosity of the hydraulic oil causes significant resistance to the metering pumps, easily leading to engine start-up failure. If the user cannot start the engine, they may continue to attempt to start it. In low-temperature conditions, the aftertreatment system is prone to clogging due to the difficulty in starting the engine, resulting in a large amount of particulate matter. If clogging occurs during startup, the combustion process cannot function properly because the engine is not running normally. Restarting the engine will produce carbon deposits that can cause piston ring sticking, further leading to engine cylinder scoring and ultimately damaging the engine.

[0004] The information disclosed above in this background section is only intended to enhance the understanding of this background section, and therefore may include prior art that is not known to those skilled in the art. Utility Model Content

[0005] The purpose of this utility model is to provide a paver material conveying hydraulic system and a paver that enables the engine to start normally under low temperature conditions and avoids engine damage.

[0006] On the one hand, this utility model provides a paver material conveying hydraulic system, which includes:

[0007] First material conveying motor;

[0008] A first hydraulic pump is used to connect to the engine drive, and the input end of the first hydraulic pump is connected to the oil tank;

[0009] The first material conveying control valve has a P1 port, a T1 port, an A1 port, and a B1 port. The output end of the first hydraulic pump is connected to the P1 port. The A1 port is connected to one end of the first material conveying motor, and the B1 port is connected to the other end of the first material conveying motor. The T1 port is connected to the return oil circuit, and the return oil circuit is connected to the oil tank. The first material conveying control valve enables one of the P1 port and the T1 port to be connected to the A1 port, and the other of the two ports to be connected to the B1 port. The first material conveying control valve also enables the P1 port to be disconnected, and both the A1 port and the B1 port to be connected to the T1 port.

[0010] The first cold start valve has a first oil inlet and a first oil outlet. The output end of the first hydraulic pump is connected to the first oil inlet, and the first oil outlet is connected to the return oil circuit. The first cold start valve can connect or disconnect the first oil inlet and the first oil outlet.

[0011] As a preferred technical solution for the paver material conveying hydraulic system, the paver material conveying hydraulic system further includes a first shuttle valve and a first pressure compensation valve. The two input ends of the first shuttle valve are respectively connected to the two ends of the first material conveying motor, the output end of the first shuttle valve is connected to the pilot end of the first pressure compensation valve, the input end of the first pressure compensation valve is connected to the output end of the first hydraulic pump, and the output end of the first pressure compensation valve is connected to the return oil circuit.

[0012] As a preferred technical solution for the paver material conveying hydraulic system, the paver material conveying hydraulic system further includes a first relief valve, the input end of which is connected to the input end of the first hydraulic pump, and the output end of which is connected to the return oil circuit.

[0013] As a preferred technical solution for the paver's material conveying hydraulic system, the paver's material conveying hydraulic system further includes:

[0014] Second material conveying motor;

[0015] The second hydraulic pump is used to connect to the engine drive, and the input end of the second hydraulic pump is connected to the oil tank;

[0016] The second material conveying control valve has a P2 port, a T2 port, an A2 port, and a B2 port. The output end of the second hydraulic pump is connected to the P2 port. The A2 port is connected to one end of the second material conveying motor, and the B2 port is connected to the other end of the second material conveying motor. The T2 port is connected to the return oil circuit, which is connected to the oil tank. The second material conveying control valve enables one of the P2 port and the T2 port to be connected to the A2 port, and the other of the two ports to be connected to the B2 port. The second material conveying control valve also enables the P2 port to be disconnected, and both the A2 port and the B2 port to be connected to the T2 port.

[0017] The second cold start valve has a second oil inlet and a second oil outlet. The output end of the second hydraulic pump is connected to the second oil inlet, and the second oil outlet is connected to the return oil circuit. The second cold start valve can connect or disconnect the second oil inlet and the second oil outlet.

[0018] As a preferred technical solution for the hydraulic system of the paver material conveying system, the first hydraulic pump and the second hydraulic pump are a dual pump.

[0019] As a preferred technical solution for the paver material conveying hydraulic system, the paver material conveying hydraulic system further includes a second shuttle valve and a second pressure compensation valve. The two input ends of the second shuttle valve are respectively connected to the two ends of the second material conveying motor, the output end of the second shuttle valve is connected to the pilot end of the second pressure compensation valve, the input end of the second pressure compensation valve is connected to the output end of the second hydraulic pump, and the output end of the second pressure compensation valve is connected to the return oil circuit.

[0020] As a preferred technical solution for the paver material conveying hydraulic system, the paver material conveying hydraulic system further includes a second relief valve, the input end of which is connected to the input end of the second hydraulic pump, and the output end of which is connected to the return oil circuit.

[0021] As a preferred technical solution for the paver material conveying hydraulic system, the paver material conveying hydraulic system also includes an oil cooler installed on the return oil line, and a back pressure valve connected in parallel with the oil cooler.

[0022] As a preferred technical solution for the paver material conveying hydraulic system, the paver material conveying hydraulic system further includes a filter installed in the return oil circuit, the filter being located between the oil cooler and the oil tank.

[0023] The paver material conveying hydraulic system provided by this utility model has at least the following beneficial effects:

[0024] The paver's material conveying hydraulic system includes a first material conveying motor, a first hydraulic pump, a first material conveying control valve, and a first cold start valve. The first hydraulic pump is connected to the engine drive, and its input end is connected to the oil tank. The first material conveying control valve has a P1 port, a T1 port, an A1 port, and a B1 port. The output end of the first hydraulic pump is connected to the P1 port, the A1 port is connected to one end of the first material conveying motor, the B1 port is connected to the other end of the first material conveying motor, and the T1 port is connected to the return oil circuit. The first material conveying control valve connects one of the P1 and T1 ports to the A1 port and the other to the B1 port. It also disconnects the P1 port, ensuring that both the A1 and B1 ports are connected to the T1 port. The first cold start valve has a first inlet and a first outlet. The output of the first hydraulic pump is connected to the first inlet, and the first outlet is connected to the return oil circuit. The first cold start valve can connect or disconnect the first inlet and the first outlet. In this embodiment, when starting the paver under low-temperature conditions, the first cold start valve connects the first inlet and the first outlet. At this time, a circuit is formed between the oil tank, the first hydraulic pump, the first cold start valve, and the oil tank. The first hydraulic pump draws hydraulic oil from the oil tank, and the hydraulic oil pumped out by the first hydraulic pump flows back to the oil tank through the first cold start valve. This reduces the load on the outlet of the first hydraulic pump, allowing the engine to start smoothly and preventing engine damage.

[0025] On the other hand, this utility model provides a paver, including the paver material conveying hydraulic system of any of the above-mentioned solutions, and the paver also includes an engine, which is connected to the first hydraulic pump in a transmission connection.

[0026] The low-temperature start-up control method for the paver material conveying hydraulic system provided by this utility model has at least the following beneficial effects:

[0027] The paver includes the aforementioned paver material conveying hydraulic system, which enables the engine to start smoothly when starting the machine under low-temperature conditions. Attached Figure Description

[0028] Figure 1 This is a schematic diagram of the paver's material conveying hydraulic system in an embodiment of this utility model.

[0029] In the picture:

[0030] 10. First conveying motor; 11. First hydraulic pump; 12. First conveying control valve; 13. First cold start valve; 14. First shuttle valve; 15. First pressure compensation valve; 16. First relief valve;

[0031] 20. Second conveying motor; 21. Second hydraulic pump; 22. Second conveying control valve; 23. Second cold start valve; 24. Second shuttle valve; 25. Second pressure compensation valve; 26. Second relief valve;

[0032] 30. Engine;

[0033] 40. Return oil circuit;

[0034] 51. Oil cooler; 52. Back pressure valve;

[0035] 60. Filter;

[0036] 70. Fuel tank. Detailed Implementation

[0037] The technical solution of this utility model will now be clearly and completely described with reference to the accompanying drawings. Obviously, the described embodiments are only some, not all, of the embodiments of this utility model. Based on the embodiments of this utility model, all other embodiments obtained by those skilled in the art without creative effort are within the scope of protection of this utility model.

[0038] In the description of this utility model, it should be noted that the terms "center," "upper," "lower," "left," "right," "vertical," "horizontal," "inner," and "outer," etc., indicate the orientation or positional relationship based on the orientation or positional relationship shown in the accompanying drawings. They are used only for the convenience of describing this utility model and for simplifying the description, and do not indicate or imply that the device or element referred to must have a specific orientation, or be constructed and operated in a specific orientation. Therefore, they should not be construed as limitations on this utility model. Furthermore, the terms "first" and "second" are used for descriptive purposes only and should not be construed as indicating or implying relative importance. The terms "first position" and "second position" refer to two different positions. Moreover, "above," "on top of," and "over" the first feature in relation to the second feature includes the first feature directly above and diagonally above the second feature, or simply indicates that the first feature is at a higher horizontal level than the second feature. "Below," "under," and "below" the first feature in relation to the second feature includes the first feature directly below and diagonally below the second feature, or simply indicates that the first feature is at a lower horizontal level than the second feature.

[0039] In the description of this utility model, it should be noted that, unless otherwise explicitly specified and limited, the terms "installation," "connection," and "joining" should be interpreted broadly. For example, they can refer to a fixed connection, a detachable connection, or an integral connection; they can refer to a mechanical connection or an electrical connection; they can refer to a direct connection or an indirect connection through an intermediate medium; and they can refer to the internal connection of two components. Those skilled in the art can understand the specific meaning of the above terms in this utility model based on the specific circumstances.

[0040] The embodiments of this utility model are described in detail below. Examples of these embodiments are shown in the accompanying drawings, wherein the same or similar reference numerals denote the same or similar elements or elements having the same or similar functions throughout. The embodiments described below with reference to the accompanying drawings are exemplary and are only used to explain this utility model, and should not be construed as limiting this utility model.

[0041] In the paver's hydraulic conveying system, when starting the machine under low-temperature conditions, the high viscosity of the hydraulic oil causes significant resistance to the rotation of the metering pump, easily leading to engine start-up failure. When the user fails to start the machine, they may keep trying to start it. In low-temperature conditions, the aftertreatment system is prone to blockage due to the difficulty in starting the engine, resulting in a large amount of particulate matter clogging the aftertreatment system. If the aftertreatment system becomes blocked during startup, the combustion process cannot start properly because the engine is not working normally. The carbon deposits produced when restarting the engine can easily cause piston ring sticking, further leading to engine cylinder scoring and ultimately damaging the engine itself.

[0042] To address this issue, this embodiment provides a paver material conveying hydraulic system. This paver material conveying hydraulic system can be applied to a paver and used for material conveying operations.

[0043] like Figure 1 As shown, the paver's material conveying hydraulic system includes a first material conveying motor 10, a first hydraulic pump 11, a first material conveying control valve 12, and a first cold start valve 13. The first material conveying motor 10 drives the material conveying scraper to rotate. The first hydraulic pump 11 is connected to the engine 30, and its input end is connected to the oil tank 70. The first material conveying control valve 12 has a P1 port, a T1 port, an A1 port, and a B1 port. The output end of the first hydraulic pump 11 is connected to the P1 port. The A1 port is connected to one end of the first material conveying motor 10, the B1 port is connected to the other end of the first material conveying motor 10, and the T1 port is connected to the return oil circuit 40, which is connected to the oil tank 70. The first material conveying control valve 12 enables one of the P1 oil port and the T1 oil port to be connected to the A1 oil port, and the other of the two oil ports to be connected to the B1 oil port. The first material conveying control valve 12 can also disconnect the P1 oil port, and both the A1 oil port and the B1 oil port are connected to the T1 oil port. The first cold start valve 13 has a first oil inlet and a first oil outlet. The output end of the first hydraulic pump 11 is connected to the first oil inlet, and the first oil outlet is connected to the return oil circuit 40. The first cold start valve 13 enables the first oil inlet and the first oil outlet to be connected or disconnected.

[0044] The paver material conveying hydraulic system provided in this embodiment, when starting the machine under low temperature conditions, connects the first inlet and the first outlet of oil via the first cold start valve 13. At this time, a circuit is formed between the oil tank 70, the first hydraulic pump 11, the first cold start valve 13, and the oil tank 70. The first hydraulic pump 11 draws hydraulic oil from the oil tank 70, and the hydraulic oil pumped out by the first hydraulic pump 11 flows back to the oil tank 70 through the first cold start valve 13. This reduces the load at the outlet of the first hydraulic pump 11, allowing the engine 30 to start smoothly and thus preventing damage to the engine 30.

[0045] The system utilizes a temperature sensor to collect the actual temperature of the hydraulic oil. The controller then obtains this actual temperature and compares it with a preset temperature. When the actual hydraulic oil temperature does not exceed the preset temperature, it is considered a low-temperature operating condition; when it exceeds the preset temperature, it is considered a non-low-temperature operating condition. Similarly, a speed sensor can collect the actual rotational speed of the engine 30. The controller obtains this actual rotational speed and compares it with a preset speed. When the actual rotational speed does not exceed the preset speed, it is considered a start-up condition; when it exceeds the preset speed, the engine 30 is considered to have started successfully. Therefore, when both the actual hydraulic oil temperature and the actual engine speed do not exceed the preset temperature, it can be determined that a low-temperature start-up is in progress, and the first cold start valve 13 connects the first oil inlet and the first oil outlet. When either the actual hydraulic oil temperature exceeds the preset temperature or the actual engine speed exceeds the preset speed, the first cold start valve 13 disconnects the first oil inlet and the first oil outlet.

[0046] It should be noted that the specific value of the preset temperature can be set according to actual needs. For example, this embodiment provides a scheme with a preset temperature of 0℃. Similarly, the specific value of the preset speed can also be set according to actual needs. For example, this embodiment provides a scheme with a preset speed of 500rpm.

[0047] In this embodiment, the first material conveying control valve 12 is a three-position four-way solenoid valve. The valve core movement of the first material conveying control valve 12 enables it to have a first left position, a first middle position, and a first right position. When the first material conveying control valve 12 is in the first left position, the first material conveying control valve 12 connects the P1 oil port and the B1 oil port, and connects the A1 oil port and the T1 oil port. When the first material conveying control valve 12 is in the first middle position, the first material conveying control valve 12 disconnects the P1 oil port, and connects the B1 oil port, the A1 oil port, and the T1 oil port. When the first material conveying control valve 12 is in the first right position, the first material conveying control valve 12 connects the P1 oil port and the A1 oil port, and connects the B1 oil port and the T1 oil port.

[0048] In this embodiment, the first cold start valve 13 is a two-position two-way solenoid valve, which can connect or disconnect the first oil inlet and the first oil outlet by energizing and de-energizing the solenoid terminal of the first cold start valve 13.

[0049] In some embodiments, the paver material conveying hydraulic system further includes a first shuttle valve 14 and a first pressure compensation valve 15. The two input ends of the first shuttle valve 14 are respectively connected to the two ends of the first material conveying motor 10. The output end of the first shuttle valve 14 is connected to the pilot end of the first pressure compensation valve 15. The input end of the first pressure compensation valve 15 is connected to the output end of the first hydraulic pump 11. The output end of the first pressure compensation valve 15 is connected to the return oil circuit 40. With this configuration, the first shuttle valve 14 compares the oil pressures at both ends of the first conveying motor 10 and outputs the hydraulic oil from the end with the higher oil pressure to the pilot end of the first pressure compensation valve 15. The first pressure compensation valve 15 maintains an appropriate opening based on the difference between the oil pressure at the output end of the first hydraulic pump 11 and the oil pressure at the pilot end, ensuring that the difference between the oil pressure at the output end of the first hydraulic pump 11 and the maximum oil pressure in the circuit containing the first conveying motor 10 remains stable. This also ensures that the oil pressure at port P1 of the first conveying control valve 12 remains stable compared to the maximum oil pressure at ports A1 and B1, guaranteeing normal system operation. The specific structure of the first shuttle valve 14 is existing technology and will not be described in detail here.

[0050] Specifically, such as Figure 1 As shown, the first pressure compensation valve 15 also includes a first compression spring, and the first compression spring and the hydraulic oil at the pilot end of the first pressure compensation valve 15 work together to act on one end of the valve core of the first pressure compensation valve 15, while the hydraulic oil supplied by the output end of the first hydraulic pump 11 acts on the other end of the valve core of the first pressure compensation valve 15. The forces at both ends of the valve core of the first pressure compensation valve 15 remain balanced, and the position of the valve core of the first pressure compensation valve 15 is determined by the pressure difference between the hydraulic oil supplied by the output end of the first hydraulic pump 11 and the hydraulic oil at the pilot end of the first pressure compensation valve 15, thereby enabling the first pressure compensation valve 15 to connect the output end of the first hydraulic pump 11 and the oil tank 70 with different opening degrees.

[0051] In some embodiments, the paver's material conveying hydraulic system further includes a first relief valve 16, the input end of which is connected to the input end of the first hydraulic pump 11, and the output end of the first relief valve 16 is connected to the return oil circuit 40. With this configuration, when the oil pressure at the output end of the first hydraulic pump 11 exceeds a threshold, it can flow back to the oil tank 70 through the first relief valve 16.

[0052] In this embodiment, after the engine 30 starts successfully, if the first material control valve 12 is in the first neutral position, the hydraulic oil output by the first hydraulic pump 11 will flow back to the return oil circuit through the first pressure compensation valve 15 and flow into the oil tank 70; if the first material control valve 12 is in the first left position or the first right position, the hydraulic oil output by the first hydraulic pump 11 will drive the first material motor 10 to rotate through the first material control valve 12, and then flow back to the return oil circuit 40 and back to the oil tank 70.

[0053] In some embodiments, the paver's material conveying hydraulic system further includes a second material conveying motor 20, a second hydraulic pump 21, a second material conveying control valve 22, and a second cold start valve 23. The second material conveying motor 20 drives the material conveying scraper to rotate; the second hydraulic pump 21 is connected to the engine 30, and its input end is connected to the oil tank 70; the second material conveying control valve 22 has a P2 port, a T2 port, an A2 port, and a B2 port; the output end of the second hydraulic pump 21 is connected to the P2 port; the A2 port is connected to one end of the second material conveying motor 20; the B2 port is connected to the other end of the second material conveying motor 20; the T2 port is connected to the return oil circuit 40, and the return oil circuit 40 is connected to the oil tank 70. The second material conveying control valve 22 can connect one of the P2 oil port and the T2 oil port to the A2 oil port, and the other of the two oil ports to the B2 oil port. The second material conveying control valve 22 can also disconnect the P2 oil port, and both the A2 oil port and the B2 oil port can be connected to the T2 oil port. The second cold start valve 23 has a second oil inlet and a second oil outlet. The output end of the second hydraulic pump 21 is connected to the second oil inlet, and the second oil outlet is connected to the return oil circuit 40. The second cold start valve 23 can connect or disconnect the second oil inlet and the second oil outlet. When starting the engine under low-temperature conditions, the second cold start valve 23 connects the second oil inlet and the second oil outlet. At this time, a circuit is formed between the oil tank 70, the second hydraulic pump 21, the second cold start valve 23, and the oil tank 70. The second hydraulic pump 21 draws hydraulic oil from the oil tank 70, and the hydraulic oil pumped out by the second hydraulic pump 21 flows back to the oil tank 70 through the second cold start valve 23. This reduces the load on the outlet end of the second hydraulic pump 21, allowing the engine 30 to start smoothly and thus preventing damage to the engine 30.

[0054] In this embodiment, the paver material conveying hydraulic system, when starting the machine under low-temperature conditions, connects the second inlet and the second outlet of the second cold start valve 23. At this time, a circuit is formed between the oil tank 70, the second hydraulic pump 21, the second cold start valve 23, and the oil tank 70. The second hydraulic pump 21 draws hydraulic oil from the oil tank 70, and the hydraulic oil pumped out by the second hydraulic pump 21 flows back to the oil tank 70 through the second cold start valve 23. This reduces the load at the outlet of the second hydraulic pump 21, allowing the engine 30 to start smoothly and thus preventing damage to the engine 30.

[0055] In some embodiments, the first hydraulic pump 11 and the second hydraulic pump 21 are a combined pump, which is synchronously driven to rotate by the engine 30.

[0056] In this embodiment, the second material conveying control valve 22 is a three-position four-way solenoid valve. The valve core movement of the second material conveying control valve 22 enables it to have a second left position, a second middle position, and a second right position. When the second material conveying control valve 22 is in the second left position, it connects the P2 oil port and the B2 oil port, and connects the A2 oil port and the T2 oil port. When the second material conveying control valve 22 is in the second middle position, it disconnects the P2 oil port and connects the B2 oil port, the A2 oil port, and the T2 oil port. When the second material conveying control valve 22 is in the second right position, it connects the P2 oil port and the A2 oil port, and connects the B2 oil port and the T2 oil port.

[0057] In this embodiment, the second cold start valve 23 is a two-position two-way solenoid valve, which can connect or disconnect the second oil inlet and the second oil outlet by energizing or de-energizing the solenoid terminal.

[0058] In some embodiments, the paver material conveying hydraulic system further includes a second shuttle valve 24 and a second pressure compensation valve 25. The two input ends of the second shuttle valve 24 are respectively connected to the two ends of the second material conveying motor 20. The output end of the second shuttle valve 24 is connected to the pilot end of the second pressure compensation valve 25. The input end of the second pressure compensation valve 25 is connected to the output end of the second hydraulic pump 21. The output end of the second pressure compensation valve 25 is connected to the return oil circuit 40. With this configuration, the second shuttle valve 24 compares the oil pressure at both ends of the second conveying motor 20 and outputs the hydraulic oil from the end with the higher oil pressure to the pilot end of the second pressure compensation valve 25. The second pressure compensation valve 25 maintains an appropriate opening based on the difference between the oil pressure at the output end of the second hydraulic pump 21 and the oil pressure at the pilot end, ensuring that the difference between the oil pressure at the output end of the second hydraulic pump 21 and the maximum oil pressure in the circuit containing the second conveying motor 20 remains stable. This also ensures that the difference between the oil pressure at port P2 of the second conveying control valve 22 and the maximum oil pressure at ports A2 and B2 remains stable, guaranteeing the normal operation of the system. The specific structure of the second shuttle valve 24 is existing technology and will not be described in detail here.

[0059] Specifically, such as Figure 1As shown, the second pressure compensation valve 25 also includes a second compression spring. The second compression spring and the hydraulic oil at the pilot end of the second pressure compensation valve 25 work together to act on one end of the valve core of the second pressure compensation valve 25. The hydraulic oil supplied by the output end of the second hydraulic pump 21 acts on the other end of the valve core of the second pressure compensation valve 25. The forces at both ends of the valve core of the second pressure compensation valve 25 remain balanced. The position of the valve core of the second pressure compensation valve 25 is determined by the pressure difference between the hydraulic oil supplied by the output end of the second hydraulic pump 21 and the hydraulic oil at the pilot end of the second pressure compensation valve 25. This allows the second pressure compensation valve 25 to connect the output end of the second hydraulic pump 21 and the oil tank 70 with different opening degrees.

[0060] In some embodiments, the paver's material conveying hydraulic system further includes a second relief valve 26. The input end of the second relief valve 26 is connected to the input end of the second hydraulic pump 21, and the output end of the second relief valve 26 is connected to the return oil circuit 40. With this configuration, when the oil pressure at the output end of the second hydraulic pump 21 exceeds a threshold, it can flow back to the oil tank 70 through the second relief valve 26.

[0061] In this embodiment, after the engine 30 starts successfully, if the second material control valve 22 is in the second neutral position, the hydraulic oil output by the second hydraulic pump 21 will flow back to the return oil circuit through the second pressure compensation valve 25 and flow into the oil tank 70; if the second material control valve 22 is in the second left position or the second right position, the hydraulic oil output by the second hydraulic pump 21 will drive the second material motor 20 to rotate through the second material control valve 22, and then flow back to the return oil circuit 40 and back to the oil tank 70.

[0062] In some embodiments, the paver's material conveying hydraulic system further includes an oil cooler 51 disposed on the return oil line 40, and a back pressure valve 52 connected in parallel with the oil cooler 51. This configuration allows the oil cooler 51 to cool and reduce the temperature of the flowing hydraulic oil, and when the oil cooler 51 becomes blocked, the hydraulic oil can bypass the oil cooler 51 through the back pressure valve 52 and continue to flow back to the oil tank 70.

[0063] In some embodiments, the paver's material conveying hydraulic system further includes a filter 60 disposed in the return oil line 40, located between the oil cooler 51 and the oil tank 70. By providing the filter 60, the flowing hydraulic oil can be filtered to remove impurities from the hydraulic oil.

[0064] This embodiment also provides a paver, which includes the aforementioned paver material conveying hydraulic system. The paver also includes an engine 30, which is drivenly connected to the first hydraulic pump 11. Preferably, the engine 30 is also drivenly connected to the second hydraulic pump 21. When the engine 30 is started under low-temperature conditions, the first cold start valve 13 disconnects the first oil inlet and the first oil outlet, and the second cold start valve 23 disconnects the second oil inlet and the second oil outlet. This reduces the load on the outlet ends of the first hydraulic pump 11 and the second hydraulic pump 21, allowing the engine 30 to start smoothly.

[0065] The above description is merely a preferred embodiment of this utility model and an explanation of the technical principles employed. Those skilled in the art should understand that the scope of disclosure involved in this utility model is not limited to the technical solutions formed by specific combinations of the above-described technical features, but should also cover other technical solutions formed by arbitrary combinations of the above-described technical features or their equivalents without departing from the above-described concept. For example, technical solutions formed by substituting the above-described features with (but not limited to) technical features with similar functions disclosed in this utility model.

[0066] Furthermore, while several specific implementation details are included in the above discussion, these should not be construed as limiting the scope of this invention. Certain features described in the context of individual embodiments may also be implemented in combination in a single embodiment. Conversely, various features described in the context of a single embodiment may also be implemented individually or in any suitable sub-combination in multiple embodiments.

[0067] Although the subject matter has been described using language specific to structural features and / or methodological logic, it should be understood that the subject matter defined in the appended claims is not necessarily limited to the specific features or actions described above. Rather, the specific features and actions described above are merely illustrative examples of implementing the claims.

Claims

1. A paver material conveying hydraulic system, characterized in that, include: First feeding motor (10); A first hydraulic pump (11) is used to drive the engine (30), and the input end of the first hydraulic pump (11) is connected to the oil tank (70); The first material conveying control valve (12) has a P1 port, a T1 port, an A1 port and a B1 port. The output end of the first hydraulic pump (11) is connected to the P1 port. The A1 port is connected to one end of the first material conveying motor (10). The B1 port is connected to the other end of the first material conveying motor (10). The T1 port is connected to the return oil circuit (40). The return oil circuit (40) is connected to the oil tank (70). The first material conveying control valve (12) can make one of the P1 port and the T1 port connected to the A1 port and the other of the two ports connected to the B1 port. The first material conveying control valve (12) can also make the P1 port disconnected, and both the A1 port and the B1 port are connected to the T1 port. The first cold start valve (13) has a first oil inlet and a first oil outlet. The output end of the first hydraulic pump (11) is connected to the first oil inlet, and the first oil outlet is connected to the return oil circuit (40). The first cold start valve (13) can make the first oil inlet and the first oil outlet connected or disconnected.

2. The paver material conveying hydraulic system according to claim 1, characterized in that, The paver's material conveying hydraulic system also includes a first shuttle valve (14) and a first pressure compensation valve (15). The two input ends of the first shuttle valve (14) are respectively connected to the two ends of the first material conveying motor (10). The output end of the first shuttle valve (14) is connected to the pilot end of the first pressure compensation valve (15). The input end of the first pressure compensation valve (15) is connected to the output end of the first hydraulic pump (11). The output end of the first pressure compensation valve (15) is connected to the return oil circuit (40).

3. The paver material conveying hydraulic system according to claim 1, characterized in that, The paver material conveying hydraulic system also includes a first overflow valve (16), the input end of which is connected to the input end of the first hydraulic pump (11), and the output end of which is connected to the return oil circuit (40).

4. The paver material conveying hydraulic system according to claim 1, characterized in that, The paver's material conveying hydraulic system also includes: Second feeding motor (20); The second hydraulic pump (21) is used to drive the engine (30), and the input end of the second hydraulic pump (21) is connected to the oil tank (70); The second material control valve (22) has a P2 port, a T2 port, an A2 port and a B2 port. The output end of the second hydraulic pump (21) is connected to the P2 port. The A2 port is connected to one end of the second material conveying motor (20). The B2 port is connected to the other end of the second material conveying motor (20). The T2 port is connected to the return oil circuit (40). The return oil circuit (40) is connected to the oil tank (70). The second material control valve (22) can make one of the P2 port and the T2 port connected to the A2 port and the other of the two ports connected to the B2 port. The second material control valve (22) can also make the P2 port disconnected, and both the A2 port and the B2 port are connected to the T2 port. The second cold start valve (23) has a second oil inlet and a second oil outlet. The output end of the second hydraulic pump (21) is connected to the second oil inlet, and the second oil outlet is connected to the return oil circuit (40). The second cold start valve (23) can make the second oil inlet and the second oil outlet connected or disconnected.

5. The paver material conveying hydraulic system according to claim 4, characterized in that, The first hydraulic pump (11) and the second hydraulic pump (21) are a tandem pump.

6. The paver material conveying hydraulic system according to claim 4, characterized in that, The paver's material conveying hydraulic system also includes a second shuttle valve (24) and a second pressure compensation valve (25). The two input ends of the second shuttle valve (24) are respectively connected to the two ends of the second material conveying motor (20). The output end of the second shuttle valve (24) is connected to the pilot end of the second pressure compensation valve (25). The input end of the second pressure compensation valve (25) is connected to the output end of the second hydraulic pump (21). The output end of the second pressure compensation valve (25) is connected to the return oil circuit (40).

7. The paver material conveying hydraulic system according to claim 4, characterized in that, The paver material conveying hydraulic system also includes a second relief valve (26), the input end of which is connected to the input end of the second hydraulic pump (21), and the output end of which is connected to the return oil circuit (40).

8. The paver material conveying hydraulic system according to any one of claims 1-7, characterized in that, The paver material conveying hydraulic system also includes an oil cooler (51) installed on the return oil circuit (40) and a back pressure valve (52) connected in parallel with the oil cooler (51).

9. The paver material conveying hydraulic system according to claim 8, characterized in that, The paver's material conveying hydraulic system also includes a filter (60) installed in the return oil circuit (40), the filter (60) being located between the oil cooler (51) and the oil tank (70).

10. A paver, characterized in that, The paver includes the material conveying hydraulic system of any one of claims 1-9, and the paver further includes an engine (30) that is connected to the first hydraulic pump (11).

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