Vehicle hydraulic system, control method thereof and garbage truck

Abstract

The invention provides a vehicle hydraulic system, a control method of the vehicle hydraulic system and a garbage truck, and the control method comprises the steps that according to a received oil cylinder contraction instruction, the opening and closing states of a first valve and a second valve are controlled, so that hydraulic oil in a single-action oil cylinder flows into an oil tank through at least one of an independent oil way and a convergence oil way. The technical problem that the shrinkage speed of the single-action oil cylinder cannot be accurately controlled is solved.

Description

Technical Field

[0001] The present application relates to the field of hydraulic systems, and in particular to a vehicle hydraulic system and a control method thereof, and a garbage truck. Background Art

[0002] Nowadays, trucks, such as garbage trucks, sand trucks, etc., are equipped with hydraulic systems to facilitate transportation and unloading. The cylinders in the hydraulic system can automatically lift the carriage or some other parts to speed up the efficiency of cargo loading and unloading.

[0003] There are many cylinders in the hydraulic system. Based on the different positions of the cylinders and the different loads, some cylinders require a slower target retraction speed, while some cylinders require a faster target retraction speed, so as to coordinate the various components in the running vehicle to cooperate with each other, improve work efficiency and avoid the occurrence of safety accidents.

[0004] However, many washing liquid systems now use complete hydraulic systems to achieve parallel control of multiple cylinders. Since it is a complete hydraulic system, the pipe diameters of the oil supply and return lines for each cylinder in the hydraulic system are all the same, which can meet the lifting and lowering requirements of general cylinders. However, when the hydraulic system needs to control a cylinder that requires a faster target retraction speed, the same oil circuit of the hydraulic system will not be able to meet the user's needs. Summary of the invention

[0005] In order to solve the above technical problems, an embodiment of the present application provides a vehicle hydraulic system and a control method thereof to achieve controllable retraction speed of a single-acting cylinder.

[0006] According to one embodiment of the present application, the present application provides a vehicle hydraulic system, the vehicle hydraulic system comprising:

[0007] Oil tank, used to store hydraulic oil;

[0008] An oil pump, used to extract the hydraulic oil in the oil tank and transport it;

[0009] Single-acting cylinders are used to extend and retract according to the pressure of the hydraulic oil in the single-acting cylinder to push the load;

[0010] A confluent oil circuit, a first end of which is in communication with an interface of the single-acting oil cylinder, and a first valve is disposed on the confluent oil circuit;

[0011] a first multi-way valve, the first multi-way valve being in communication with the second end of the combined oil circuit, and the first multi-way valve being used to control the second end of the combined oil circuit to be in communication with the output end of the oil pump or the input end of the oil tank;

[0012] An independent oil circuit, the input end of the independent oil circuit is arranged between the first end of the merged oil circuit and the first valve, the output end of the independent oil circuit is connected to the input end of the oil tank, a second valve is provided on the independent oil circuit, and the independent oil circuit is used to transport the hydraulic oil in the single-acting cylinder to the oil tank.

[0013] According to an embodiment of the present application, a third valve is further provided in the vehicle hydraulic system, and two ends of the third valve are respectively connected to two sides of the second valve.

[0014] According to one embodiment of the present application, the first interface of the first multi-way valve is communicated with the second end of the merged oil circuit, the second interface of the first multi-way valve is communicated with the output end of the oil pump, and the third interface of the first multi-way valve is communicated with the input end of the oil tank;

[0015] Wherein, when the first interface of the first multi-way valve is connected only to the second interface of the first multi-way valve, the second end of the combined oil circuit is connected to the output end of the oil pump via the first multi-way valve, and the hydraulic oil in the oil tank can be delivered to the single-acting oil cylinder;

[0016] When the first interface of the first multi-way valve is connected only to the third interface of the first multi-way valve, the second end of the merged oil circuit is connected to the input end of the oil tank via the first multi-way valve, and the hydraulic oil in the single-acting cylinder can be delivered to the oil tank.

[0017] According to one embodiment of the present application, a double-acting cylinder is provided in the vehicle hydraulic system, a first interface and a second interface are provided in the double-acting cylinder, and a piston in the double-acting cylinder moves between the first interface and the second interface of the double-acting cylinder to drive a piston rod connected to the piston to move;

[0018] The vehicle hydraulic system is further provided with a second multi-way valve, a first interface of the second multi-way valve is communicated with a first interface of the double-acting oil cylinder, a second interface of the second multi-way valve is communicated with a second interface of the double-acting oil cylinder, a third interface of the second multi-way valve is communicated with an output end of the oil pump, and a fourth interface of the second multi-way valve is communicated with an input end of the oil tank;

[0019] The first interface of the second multi-way valve is connected to the third interface of the second multi-way valve, and the second interface of the second multi-way valve is connected to the fourth interface of the second multi-way valve, so that the first interface of the double-acting oil cylinder is connected to the output end of the oil pump, and the second interface of the double-acting oil cylinder is connected to the input end of the oil tank, and the piston in the double-acting oil cylinder moves toward the second interface of the double-acting oil cylinder, and the piston rod extends;

[0020] The first interface of the second multi-way valve is connected with the fourth interface of the second multi-way valve, and the second interface of the second multi-way valve is connected with the third interface of the second multi-way valve, so that the first interface of the double-acting cylinder is connected with the input end of the oil tank, and the second interface of the double-acting cylinder is connected with the output end of the oil pump, the piston in the double-acting cylinder moves toward the first interface of the double-acting cylinder, and the piston rod retracts.

[0021] According to one embodiment of the present application, the oil pump is a load-sensitive oil pump, the first multi-way valve and the second multi-way valve are load-sensitive proportional valves, the load-sensitive oil pump and the load-sensitive proportional valve are signal-connected, the load-sensitive proportional valve controls the speed of the oil pump according to the acquired load oil pressure to control the pressure difference between the load oil pressure and the output oil pressure of the load-sensitive oil pump, and the load oil pressure includes the oil pressure in the single-acting cylinder and the oil pressure in the double-acting cylinder.

[0022] According to an embodiment of the present application, the present application provides a control method, which is applied to any one of the vehicle hydraulic systems described above, and the control method includes:

[0023] According to the received cylinder contraction instruction, the opening and closing states of the first valve and the second valve are controlled so that the hydraulic oil in the single-acting cylinder flows into the oil tank via at least one of the independent oil circuit and the combined oil circuit.

[0024] According to one embodiment of the present application, the control method further includes:

[0025] According to the cylinder retraction instruction, a target retraction speed of the single-acting cylinder is obtained;

[0026] According to the speed range to which the target contraction speed belongs, the opening and closing states of the first valve and the second valve are controlled so that the hydraulic oil in the single-acting cylinder flows into the oil tank via the independent oil circuit and / or the combined oil circuit.

[0027] According to an embodiment of the present application, controlling the opening and closing states of the first valve and the second valve according to the speed interval to which the target contraction speed belongs includes:

[0028] If the target contraction speed is within the first speed range, the first valve is controlled to be opened and the second valve is controlled to be closed, so that the hydraulic oil in the single-acting cylinder flows to the oil tank via the combined oil path;

[0029] If the target contraction speed is within a second speed interval, the first valve is controlled to be closed and the second valve is controlled to be opened, so that the hydraulic oil in the single-acting cylinder flows to the oil tank via the independent oil path, and the minimum value of the second speed interval is greater than the maximum value of the first speed interval;

[0030] If the target contraction speed is within a third speed range, the first valve and the second valve are opened to allow the hydraulic oil in the single-acting cylinder to flow to the oil tank via the merged oil circuit and the independent oil circuit, and the minimum value of the third speed range is greater than the maximum value of the second speed range.

[0031] According to an embodiment of the present application, the opening and closing states of the first valve and the second valve are controlled according to the speed interval to which the target contraction speed belongs, and the control method further includes:

[0032] According to the pipe diameters of the independent oil circuit and the merged oil circuit, the speed interval is divided into a first speed interval, a second speed interval, and a third speed interval; wherein the minimum value of the second speed interval is greater than the maximum value of the first speed interval, and the minimum value of the third speed interval is greater than the maximum value of the second speed interval.

[0033] According to an embodiment of the present application, the speed interval is divided into a first speed interval, a second speed interval, and a third speed interval according to the pipe diameters of the independent oil circuit and the merged oil circuit, including:

[0034] Calculate the maximum pipeline flow of the independent oil circuit and the merged oil circuit according to the pipeline diameters of the independent oil circuit and the merged oil circuit and the pressure at the interface of the single-acting cylinder, the pipeline diameter of the independent oil circuit being greater than the pipeline diameter of the merged oil circuit;

[0035] The target contraction speed of the single-acting cylinder when working at the maximum pipeline flow rate of the merged oil circuit is a first contraction speed, and the target contraction speed of the single-acting cylinder when working at the maximum pipeline flow rate of the independent oil circuit is a second contraction speed;

[0036] A first speed interval, a second speed interval, and a third speed interval are determined according to the first contraction speed and the second contraction speed; wherein:

[0037] The first speed interval is greater than zero and less than or equal to the first contraction speed;

[0038] The second speed interval is greater than the first contraction speed, and less than or equal to the second contraction speed;

[0039] The third speed interval is greater than the second contraction speed, and less than or equal to the sum of the first contraction speed and the second contraction speed.

[0040] According to an embodiment of the present application, according to the received cylinder retraction instruction, controlling the opening and closing states of the first valve and the second valve includes:

[0041] Determine the maximum pipeline flow of the independent oil circuit and the merged oil circuit according to the pipeline diameters of the independent oil circuit and the merged oil circuit and the pressure at the interface of the single-acting cylinder;

[0042] According to the content indicated by the cylinder retraction instruction, a target retraction speed of the single-acting cylinder is obtained;

[0043] Calculating the required discharge flow rate of the single-acting cylinder according to the target contraction speed and the internal space parameters of the single-acting cylinder;

[0044] According to the maximum pipeline flow rates of the merged oil circuit and the independent oil circuit, at least one target oil circuit is selected from the merged oil circuit and the independent oil circuit to transport the hydraulic oil in the single-acting cylinder back to the oil tank, and the sum of the maximum pipeline flow rates of the target oil circuits is greater than or equal to the discharge flow rate.

[0045] According to an embodiment of the present application, the present application provides a garbage truck, applying the control method as described in any one of the above claims;

[0046] The garbage truck comprises the vehicle hydraulic system, a vehicle body and a vehicle front, wherein the vehicle body comprises a vehicle box and a vehicle frame, and the single-acting cylinder is arranged between the vehicle box and the vehicle frame and is used for pushing the vehicle box to flip the vehicle box relative to the vehicle frame.

[0047] According to one embodiment of the present application, the double-acting cylinder in the vehicle hydraulic system includes:

[0048] A compression cylinder, which is arranged in the garbage truck and is used to push and compress the garbage in the truck box;

[0049] A tailgate cylinder, which is arranged in the garbage truck and is used to push the tailgate arranged on one side of the vehicle box to control the opening and closing of the tailgate;

[0050] A top cover oil cylinder is arranged in the garbage truck and is used to push a top cover arranged at the loading port of the vehicle box to control the opening and closing of the loading port.

[0051] By setting up two oil circuits at the same time, the application can make the hydraulic oil in the single-acting cylinder flow back to the oil tank at the same time, so that the upper limit of the target retraction speed of the single-acting cylinder is greatly increased. On the other hand, by controlling the opening state of the first valve and the second valve, the speed of the hydraulic oil in the single-acting cylinder flowing back to the oil tank can be adjusted to a greater extent, that is, the degree of adjustment of the retraction speed of the single-acting cylinder is increased. Finally, through the three opening and closing methods of the first valve and the second valve, the retraction speed of the single-acting cylinder is controlled at three levels, which is beneficial for users to operate the single-acting cylinder at different retraction speeds according to different situations.

[0052] Other features and advantages of the present application will become apparent from the following detailed description, or may be learned in part by the practice of the present application.

[0053] It should be understood that the foregoing general description and the following detailed description are exemplary only and are not restrictive of the present application. BRIEF DESCRIPTION OF THE DRAWINGS

[0054] The above and other objects, features and advantages of the present application will become more apparent by describing in detail exemplary embodiments thereof with reference to the attached drawings.

[0055] Figure 1 A schematic diagram of a vehicle hydraulic system according to an embodiment of the present application is shown.

[0056] Figure 2 A schematic diagram of a hydraulic system according to an embodiment of the present application is shown.

[0057] Figure 3 A schematic diagram of a third valve according to an embodiment of the present application is shown.

[0058] Figure 4 A schematic diagram of oil inlet and oil return of a single-acting cylinder according to an embodiment of the present application is shown.

[0059] Figure 5 A physical schematic diagram of a hydraulic system according to an embodiment of the present application is shown.

[0060] Figure 6 Shows Figure 5 The connection relationship between the first valve and the second valve.

[0061] Figure 7 A schematic diagram showing the distribution of double-acting cylinders in a hydraulic system according to an embodiment of the present application is shown.

[0062] Figure 8 A schematic diagram showing a bidirectional balancing valve provided between a double-acting cylinder and a second multi-way valve according to an embodiment of the present application is shown.

[0063] Fig. 9 A schematic diagram of a vehicle hydraulic system provided with a filter according to an embodiment of the present application is shown.

[0064] Fig.10 A schematic diagram of a vehicle hydraulic system provided with a radiator according to an embodiment of the present application is shown.

[0065] Fig.11 A control method for a vehicle hydraulic system according to an embodiment of the present application is shown.

[0066] Fig.12A flow chart of controlling the opening and closing states of the first valve and the second valve according to the speed interval to which the target contraction speed belongs according to an embodiment of the present application is shown.

[0067] Fig.13 A flow chart for determining each speed interval according to an embodiment of the present application is shown.

[0068] Fig.14 A flow chart for accurately controlling a target retraction speed of a single-acting cylinder according to an embodiment of the present application is shown.

[0069] Fig.15 A flow chart of controlling the opening and closing states of the first valve and the second valve according to a cylinder contraction instruction according to another embodiment of the present application is shown.

[0070] Fig.16 A schematic structural diagram of a garbage truck according to an embodiment of the present application is shown.

[0071] Fig.17 A schematic structural diagram of a garbage truck according to another embodiment of the present application is shown.

[0072] Fig.18 A partial structural schematic diagram of a box body, a top cover, and a top cover opening and closing assembly according to an embodiment of the present application is shown.

[0073] Fig.19 A partial structural schematic diagram of a box body, a tailgate, and a tailgate opening and closing assembly according to an embodiment of the present application is shown.

[0074] Fig. 20 A partial structural schematic diagram of a box body and a garbage compression assembly according to an embodiment of the present application is shown.

[0075] Description of reference numerals:

[0076] 110, vehicle body; 111, vehicle frame; 112, vehicle box; 1121, box; 11211, loading port; 11212, discharge port; 11213, compression chamber; 11214, storage chamber; 1122, top cover; 1223, tailgate; 120, vehicle head; 210, fuel tank; 220, fuel pump; 231, single-acting cylinder; 232, double-acting cylinder; 2321, compression cylinder; 2322, tailgate cylinder; 2323, top cover cylinder; 241, first valve; 2411, first valve switch; 2422, first end of first valve; 2423, second end of first valve; 242, second valve; 2421, second valve switch; 2422, first end of second valve; 2423, second The second end of the valve; 251, the first multi-way valve; 243, the third valve; 252, the second multi-way valve; 260, the filter; 270, the radiator; 280, the two-way balancing valve; 290, the three-way valve; 291, the first interface of the three-way valve; 292, the second interface of the three-way valve; 293, the third interface of the three-way valve; 310, the top cover opening and closing assembly; 311, the top cover support; 312, the bending part; 313, the top cover cylinder support; 320, the tailgate opening and closing assembly; 321, the locking rod; 322, the locking slider; 3221, the locking bevel; 324 (323), the supporting pin; 331, the single-acting cylinder support; 332, the subframe; 340, the garbage compression assembly; 341, the compression head; 342, the guide plate. DETAILED DESCRIPTION

[0077] Example embodiments will now be described more fully with reference to the accompanying drawings. However, example embodiments can be implemented in a variety of forms and should not be construed as limited to the examples set forth herein; rather, these example embodiments are provided so that the description of the present application will be more comprehensive and complete and the concepts of the example embodiments will be fully conveyed to those skilled in the art. The accompanying drawings are only schematic illustrations of the present application and are not necessarily drawn to scale. The same reference numerals in the figures represent the same or similar parts, and thus their repeated description will be omitted.

[0078] In addition, the described features, structures or characteristics may be combined in one or more example embodiments in any suitable manner. In the following description, many specific details are provided to provide a full understanding of the example embodiments of the present application. However, those skilled in the art will appreciate that the technical solution of the present application may be practiced while omitting one or more of the specific details, or other methods, components, steps, etc. may be adopted. In other cases, known structures, methods, implementations or operations are not shown or described in detail to avoid obscuring the present application and making the various aspects of the present application obscure.

[0079] The flowcharts shown in the accompanying drawings are only exemplary illustrations and do not necessarily include all the contents and operations / steps, nor do they have to be executed in the described order. For example, some operations / steps can be decomposed, while some operations / steps can be combined or partially combined, so the actual execution order may change according to the actual situation. It should also be noted that the "multiple" mentioned in this application refers to two or more. "And / or" describes the association relationship of associated objects, indicating that three relationships can exist. For example, A and / or B can represent: A exists alone, A and B exist at the same time, and B exists alone. The character " / " generally indicates that the previous and subsequent associated objects are in an "or" relationship.

[0080] The terms "first", "second", "third", "fourth", etc. in the specification, claims and drawings of this application are used to distinguish different objects rather than to describe a specific order. The terms "include" and "have" and any variations thereof are intended to cover non-exclusive inclusions.

[0081] See also Figure 1 , Figure 1 A schematic diagram of a vehicle hydraulic system according to an embodiment of the present application is shown. The vehicle hydraulic system includes an oil tank 210, an oil pump 220, a single-acting oil cylinder 231, a confluent oil circuit, a first multi-way valve 251, and an independent oil circuit. The confluent oil circuit is provided with a first valve 241, and the independent oil circuit is provided with a second valve 242.

[0082] The oil tank 210 is used to store hydraulic oil.

[0083] The oil pump 220 is used to pump the hydraulic oil in the oil tank 210 to the single-acting cylinder 231 .

[0084] The single-acting cylinder 231, also known as the telescopic cylinder, determines its telescopic length based on the amount of hydraulic oil in the cylinder body. The more hydraulic oil in the cylinder body, the longer the length of the single-acting cylinder 231, until the single-acting cylinder 231 can no longer be extended. The less hydraulic oil in the cylinder body, the shorter the length of the single-acting cylinder 231, until the single-acting cylinder 231 can no longer be retracted. It should be further clarified that there is only one interface on the cylinder body of the single-acting cylinder 231, which is used to transport hydraulic oil to the inside of the single-acting cylinder 231 and also to output hydraulic oil from the inside of the single-acting cylinder 231 to the outside.

[0085] As Figure 2 As shown, Figure 2The schematic diagram of the hydraulic system according to one embodiment of the present application is shown. The input end of the oil pump 220 is connected to the output end of the oil tank 210, and the output end of the oil pump 220 can be connected to the second end of the confluent oil circuit through the first multi-way valve 251. The oil circuit between the first multi-way valve 251 and the single-acting oil cylinder 231 is a confluent oil circuit. The input end of the oil tank 210 can be connected to the second end of the confluent oil circuit via the first multi-way valve 251. The first end of the confluent oil circuit is connected to the interface of the single-acting oil cylinder 231.

[0086] In the embodiment of the present application, the first multi-way valve 251 can only connect the second end of the combined oil circuit to the input end of the oil tank 210, or can only connect the second end of the combined oil circuit to the output end of the oil pump 220. That is, when the first multi-way valve 251 is in different working states, the second end of the combined oil circuit is connected to different objects.

[0087] When the second end of the combined oil circuit is connected to the output end of the oil pump 220 via the first multi-way valve 251, and the first valve 241 on the combined oil circuit is opened, the oil pump 220 starts, and the hydraulic oil passes through the oil pump 220, the first multi-way valve 251, and the combined oil circuit in sequence and enters the single-acting cylinder 231, thereby extending the single-acting cylinder 231.

[0088] When the second end of the combined oil circuit is connected to the input end of the oil tank 210 via the first multi-way valve 251, and the first valve 241 on the combined oil circuit is opened, the hydraulic oil in the single-acting cylinder 231 flows back to the oil tank 210 through the combined oil circuit and the first multi-way valve 251 in sequence, thereby realizing the contraction of the single-acting cylinder 231.

[0089] Therefore, the combined oil circuit can realize oil inlet or oil outlet to the single-acting cylinder 231 through the first multi-way valve 251 .

[0090] In some embodiments, the first interface of the first multi-way valve 251 is connected to the second end of the combined oil circuit, the second interface of the first multi-way valve 251 is connected to the output end of the oil pump 220, and the third interface of the first multi-way valve 251 is connected to the input end of the oil tank 210;

[0091] When the first interface of the first multi-way valve 251 is only connected to the second interface of the first multi-way valve 251, the second end of the combined oil circuit is connected to the output end of the oil pump 220 via the first multi-way valve 251, and the hydraulic oil can be delivered to the single-acting cylinder 231;

[0092] When the first interface of the first multi-way valve 251 is only connected to the third interface of the first multi-way valve 251, the second end of the combined oil circuit is connected to the input end of the oil tank 210 via the first multi-way valve 251, and the hydraulic oil in the single-acting cylinder 231 is input into the oil tank 210.

[0093] In some embodiments, the first valve 241 is a solenoid steering valve for limiting the flow direction of hydraulic oil. The solenoid steering valve can only pass liquid in one direction.

[0094] For example, when the single-acting cylinder 231 is supplied with oil, the electromagnetic steering valve is powered off, and the hydraulic oil can only flow to the single-acting cylinder 231 through the electromagnetic steering valve, that is, the hydraulic oil can only flow from the second end of the merged oil circuit to the first end of the merged oil circuit. When the single-acting cylinder 231 is discharged from oil, the electromagnetic steering valve is powered on, and the hydraulic oil can only flow to the first multi-way valve 251 through the electromagnetic steering valve. That is, the hydraulic oil can only flow from the first end of the merged oil circuit to the second end of the merged oil circuit.

[0095] In some embodiments, the vehicle hydraulic system further includes an independent oil circuit. The independent oil circuit is only used to transport the hydraulic oil in the single-acting oil cylinder 231 to the oil tank 210. The input end of the independent oil circuit is arranged between the first end of the confluent oil circuit and the first valve 241, the output end of the independent oil circuit is connected to the input end of the oil tank 210, and the second valve 242 is arranged on the independent oil circuit.

[0096] That is, as long as the second valve 242 is opened, the hydraulic oil in the single-acting cylinder 231 will enter the oil tank 210 through the first end of the combined oil circuit and the second valve 242, thereby realizing the contraction of the single-acting cylinder 231.

[0097] In some embodiments, a plurality of independent oil circuits are provided to further optimize the retraction speed of the single-acting cylinder 231 or to further refine the control of the retraction speed of the cylinder.

[0098] If a plurality of independent oil circuits are provided, the contraction speed of the single-acting oil cylinder 231 can be controlled by opening different numbers of independent oil circuits, so that the single-acting oil cylinder 231 contracts at different speeds.

[0099] In some embodiments, the second valve 242 is also an electromagnetic steering valve, that is, when the independent oil circuit is not needed to transport the hydraulic oil in the single-acting cylinder 231 to the oil tank 210, the second valve 242 is adjusted to allow the liquid to flow only to the input end of the independent oil circuit. When the independent oil circuit is needed to transport the hydraulic oil in the single-acting cylinder 231 to the oil tank 210, the second valve 242 is adjusted to allow the liquid to flow only to the output end of the independent oil circuit, so that the hydraulic oil in the single-acting cylinder 231 flows to the oil tank 210.

[0100] For example, when the electromagnetic steering valve as the second valve 242 is powered off, the liquid can only flow to the input end of the independent oil circuit, and the hydraulic oil in the single-acting cylinder 231 is prevented from flowing out. When the electromagnetic steering valve as the second valve 242 is powered on, the liquid can only flow to the output end of the independent oil circuit, and the hydraulic oil in the single-acting cylinder 231 flows to the oil tank 210 via the independent oil circuit, so that the single-acting cylinder 231 is contracted.

[0101] In some embodiments, when the first valve 241 is opened, the second valve 242 is closed, and the second end of the merged oil circuit is connected to the input end of the oil tank 210 via the first multi-way valve 251, the hydraulic oil in the single-acting cylinder flows to the oil tank 210 via the first multi-way valve 251, thereby realizing the slow contraction of the single-acting cylinder 231.

[0102] In some embodiments, the diameter of the independent oil circuit is larger than the diameter of the combined oil circuit and other oil circuits. When the first valve 241 is closed and the second valve 242 is opened, the hydraulic oil in the single-acting oil cylinder flows to the oil tank 210 via the independent oil circuit, thereby realizing the medium-speed contraction of the single-acting oil cylinder 231.

[0103] In some embodiments, when the first valve 241 is opened and the second valve 242 is opened, the second end of the combined oil circuit is connected to the input end of the oil tank 210 via the first multi-way valve 251, and the hydraulic oil in the single-acting cylinder flows to the oil tank 210 via the first multi-way valve 251 and the independent oil circuit, respectively, to achieve rapid retraction of the single-acting cylinder 231.

[0104] Through the description of the above embodiments, it can be seen that Figure 2 The described vehicle hydraulic system realizes a three-level speed change of the return oil of the single-acting cylinder 231 by setting up two oil circuits for oil return, thereby realizing a three-level change of the contraction speed of the single-acting cylinder 231, giving users more choices and enabling the single-acting cylinder 231 to extend and retract at different speeds when dealing with different situations.

[0105] See also Figure 2 and Figure 3 , Figure 3 FIG. 2 shows a schematic diagram of a third valve 243 according to an embodiment of the present application.

[0106] In some embodiments, a third valve 243 is further provided in the hydraulic system, and the two ends of the third valve 243 are respectively connected to the two sides of the second valve 242. That is, when the second valve 242 is closed, opening the third valve 243 can also allow the hydraulic oil in the single-acting cylinder 231 to flow back to the oil tank 210. This is to prevent the single-acting cylinder 231 from being unable to contract or the hydraulic oil in the single-acting cylinder 231 from being unable to flow back to the oil tank 210 when the first valve 241 and the second valve 242 fail. The hydraulic oil in the single-acting cylinder 231 can be made to flow back to the oil tank 210 by controlling the opening and closing of the third valve 243.

[0107] In some embodiments, the third valve 243 is a solenoid steering valve and is electrically connected to a separate power source.

[0108] In some embodiments, the third valve 243 is a manual valve, and the user can manually control the opening and closing of the valve.

[0109] See also Figure 4 , Figure 4 A schematic diagram of oil inlet and oil return of a single-acting cylinder according to an embodiment of the present application is shown. Figure 4 As described, the single-acting cylinder 231 can return oil through the second valve 242 to be retracted. The single-acting cylinder 231 can take in oil and return oil through the first valve 241 to extend and retract, respectively.

[0110] Please continue reading Figure 5 , Figure 5 A physical schematic diagram of a hydraulic system according to an embodiment of the present application is shown.

[0111] As Figure 5 As shown, on one hand, the single-acting cylinder 231 can be connected to the oil tank 210 via the first valve 241 , the first multi-way valve 251 and the radiator 280 for oil return. On the other hand, the single-acting cylinder can be directly connected to the oil tank 210 via the second valve 242 .

[0112] See also Figure 5 and Figure 6 , Figure 6 Shows Figure 5 The connection relationship between the first valve and the second valve. Figure 6 As shown, the second valve 242 is provided with a second valve switch 2421, a first end 2422 of the second valve, and a second end 2423 of the second valve. The first valve 241 is provided with a first valve switch 2411, a first end 2412 of the first valve, and a second end 2413 of the first valve.

[0113] A three-way valve 290 is disposed at the first end 2422 of the second valve, and the first interface 291 and the second interface 292 of the three-way valve are respectively connected to the single-acting cylinder and the first end 2422 of the second valve, and the third interface 293 of the three-way valve is connected to the first end 2412 of the first valve. The hydraulic oil in the single-acting cylinder 231 can directly flow to the first end 2422 of the second valve through the third interface 293 of the three-way valve. At the same time, it can also directly flow to the first end 2412 of the first valve through the third interface 293 of the three-way valve, and the first multi-way valve 251 is connected via the second end 2413 of the second valve.

[0114] See also Figure 2 and Figure 7 , Figure 7 A schematic diagram of the distribution of double-acting cylinders 232 in a hydraulic system according to an embodiment of the present application is shown.

[0115] In some embodiments, a double-acting oil cylinder 232 is provided in the hydraulic system, and a first interface and a second interface are provided in the double-acting oil cylinder 232. The piston in the double-acting oil cylinder 232 moves between the first interface and the second interface of the double-acting oil cylinder 232 to drive the piston rod connected to the piston to move;

[0116] The hydraulic system is further provided with a second multi-way valve 252, a first interface of the second multi-way valve 252 is communicated with a first interface of the double-acting oil cylinder 232, a second interface of the second multi-way valve 252 is communicated with a second interface of the double-acting oil cylinder 232, a third interface of the second multi-way valve 252 is communicated with an output end of the oil pump 220, and a fourth interface of the second multi-way valve 252 is communicated with an input end of the oil tank 210;

[0117] When the first interface of the second multi-way valve 252 is connected to the third interface of the second multi-way valve 252, so that the first interface of the double-acting oil cylinder 232 is connected to the output end of the oil pump 220, and the second interface of the second multi-way valve 252 is connected to the fourth interface of the second multi-way valve 252, so that the second interface of the double-acting oil cylinder 232 is connected to the input end of the oil tank 210, the piston in the double-acting oil cylinder 232 moves toward the second interface of the double-acting oil cylinder 232, and the piston rod connected to the piston extends;

[0118] When the first interface of the second multi-way valve 252 is connected with the fourth interface of the second multi-way valve 252, so that the first interface of the double-acting cylinder 232 is connected to the input end of the oil tank 210, the second interface of the second multi-way valve 252 is connected with the third interface of the second multi-way valve 252, so that the second interface of the double-acting cylinder 232 is connected to the output end of the oil pump 220, the piston in the double-acting cylinder 232 moves toward the first interface of the double-acting cylinder 232, and the piston rod connected to the piston retracts.

[0119] In the embodiment of the present application, the hydraulic system can include a single-acting cylinder 231 and a double-acting cylinder 232 at the same time. The simultaneous use of the single-acting cylinder 231 and the double-acting cylinder 232 can enable the hydraulic system to be applied to more machines, have a larger application field, and more application possibilities.

[0120] It should be noted that, in some embodiments, when the first multi-way valve 251 and the second multi-way valve 252 are electromagnetic steering valves, the opening or closing of the first multi-way valve 251 and the second multi-way valve 252 corresponds to the power-on or power-off state of the first multi-way valve 251 and the second multi-way valve 252. Exemplarily, the first multi-way valve 251 is powered on to be the first multi-way valve 251 is in the open state, and the first multi-way valve 251 is powered off to be the first multi-way valve 251 is in the closed state.

[0121] In some embodiments, see Figure 1 and Figure 8 , Figure 8 A schematic diagram of a bidirectional balancing valve 280 is shown between a double-acting oil cylinder 232 and a second multi-way valve 252 according to an embodiment of the present application. A first balancing valve is provided between the first interface of the double-acting oil cylinder 232 and the first interface of the second multi-way valve 252, and a second balancing valve is provided between the second interface of the double-acting oil cylinder 232 and the second interface of the second multi-way valve 252. A third interface is provided on the first balancing valve, and the third interface of the first balancing valve is connected to any position between the second balancing valve and the second multi-way valve through a first pressure differential pipeline. A third interface is provided on the second balancing valve, and the third interface of the second balancing valve is connected to any position between the first balancing valve and the second multi-way valve through a second pressure differential pipeline.

[0122] It should be clear that when the pressure difference between the first balancing valve and the second balancing valve is less than a set value, the first pressure difference pipeline and the second pressure difference pipeline are in a closed state.

[0123] The first pressure differential pipeline can only flow in one direction from the first balancing valve to the second balancing valve. When the pressure of the liquid in the first balancing valve is greater than the first set value of the liquid pressure in the second balancing valve, the first pressure differential pipeline is opened, and the hydraulic oil in the first balancing valve flows to the second balancing valve.

[0124] The second pressure differential pipeline can only flow in one direction from the second balancing valve to the first balancing valve. When the pressure of the liquid in the second balancing valve is greater than the second set value of the liquid pressure in the first balancing valve, the second pressure differential pipeline is opened, and the hydraulic oil in the first balancing valve flows to the second balancing valve.

[0125] This can prevent the double-acting oil cylinder 232 from automatically contracting when the load of the double-acting oil cylinder 232 has a small normal fluctuation. It also prevents the pressure difference on both sides of the piston in the double-acting oil cylinder from being too large, thereby damaging the hydraulic system.

[0126] In some embodiments, a plurality of double-acting cylinders 232 are provided in the hydraulic system, and each double-acting cylinder 232 is provided with a corresponding second multi-way valve 252. That is, the number of the second multi-way valves 252 is the same as the number of the double-acting cylinders 232.

[0127] In some embodiments, the oil pump 220 is a load-sensitive oil pump 220, the first multi-way valve 251 and the second multi-way valve 252 are load-sensitive proportional valves, the load-sensitive oil pump 220 is electrically connected to the load-sensitive proportional valve, the load-sensitive proportional valve controls the speed of the oil pump 220 to control the pressure difference between the load oil pressure and the output oil pressure of the load-sensitive oil pump 220, and the load oil pressure includes the oil pressure in the single-acting cylinder 231 and the oil pressure in the double-acting cylinder 232.

[0128] In the embodiment of the present application, the size of the oil outlet at the oil outlet of the oil circuit is fixed when oil is flowing in. By controlling the load-sensitive oil pump 220 to change the operating power, the oil output at the oil outlet of the oil circuit when oil is flowing in can be changed to control the extension speed of the single-acting cylinder 231 and the extension speed of the piston rod of the multi-acting cylinder.

[0129] In some embodiments, the load-sensitive oil pump 220 adjusts the operating power of the oil pump 220 so that the difference between the output oil pressure of the load-sensitive oil pump 220 and the load oil pressure always remains constant. In this way, the load-sensitive proportional valve changes the oil output at the oil outlet of the oil circuit when the oil is inlet by changing the size of the oil outlet of the oil circuit when the oil is inlet, so as to control the extension speed of the single-acting cylinder 231 and the extension speed of the piston rod of the multi-acting cylinder.

[0130] See also Figure 2 and Fig. 9 , Fig. 9 A schematic diagram of a vehicle hydraulic system provided with a filter 260 according to an embodiment of the present application is shown.

[0131] In some embodiments, the input end of the filter 260 is connected to the output end of the radiator 270, and the output end of the filter 260 is connected to the input end of the oil tank 210, so as to filter the hydraulic oil returned to the oil tank 210 to prevent the hydraulic oil from clogging the oil circuit.

[0132] See also Figure 2 and Fig.10 , Fig.10 A schematic diagram of a vehicle hydraulic system provided with a radiator 270 according to an embodiment of the present application is shown.

[0133] In some embodiments, a radiator 270 is provided in the hydraulic system to cool the hydraulic oil that is about to enter the oil tank 210 when filtering the hydraulic oil.

[0134] In some embodiments, the output end of the independent oil circuit is connected to the input end of the filter 260 , and the output end of the filter 260 is connected to the input end of the oil tank 210 .

[0135] In some embodiments, the second end of the combined oil circuit is connected to the input end of the filter 260 via the first multi-way proportional valve, and the output end of the filter 260 is connected to the input end of the oil tank 210 .

[0136] In some embodiments, the fourth interface of the second multi-way proportional valve is connected to the input end of the filter 260 , and the output end of the filter 260 is connected to the input end of the oil tank 210 .

[0137] The following embodiments are used to describe the control process of the above-mentioned vehicle hydraulic system.

[0138] In some embodiments, when the cylinder retraction instruction indicates slow retraction, the first valve 241 is controlled to open and the second valve 242 is controlled to close, and the hydraulic oil in the single-acting cylinder 231 flows back to the oil tank 210 via the combined oil path, thereby achieving slow retraction of the single-acting cylinder 231.

[0139] In some embodiments, when the cylinder contraction instruction indicates medium-speed contraction, the first valve 241 is controlled to close and the second valve 242 is controlled to open, and the hydraulic oil in the single-acting cylinder 231 flows back to the oil tank 210 through an independent oil circuit, thereby achieving medium-speed contraction of the single-acting cylinder 231.

[0140] In some embodiments, when the cylinder contraction instruction indicates rapid contraction, the first valve 241 is controlled to open, the second valve 242 is controlled to open, and the hydraulic oil in the single-acting cylinder 231 flows back to the oil tank 210 via the independent oil circuit and the merged oil circuit, respectively, to achieve rapid contraction of the single-acting cylinder 231.

[0141] In some embodiments, the contraction instruction directly indicates the opening and closing states of the first valve 241 and the second valve 242 .

[0142] In other embodiments, the contraction indicates the target contraction speed, and then controls the opening and closing state of the first valve 241 and the second valve 242 according to the target contraction speed. It should be clarified that the cylinder contraction instruction refers to the instruction information formed by the vehicle hydraulic system according to the user's operation behavior. The cylinder contraction instruction indicates the target contraction speed of the single-acting cylinder 231 or directly indicates the opening and closing state of the first valve 241 and the second valve 242. It should be further clarified that the user's operation behavior can be the user's pressing behavior on the physical button or virtual button set in the vehicle hydraulic system. The user's operation behavior can be to issue a sound message, and the vehicle hydraulic system determines the cylinder contraction instruction according to the user's sound information. The user's operation behavior can be to make a gesture or a human body posture, and the vehicle hydraulic system determines the cylinder contraction instruction according to the user's gesture or human body posture. The user's operation behavior can be to send operation information to the vehicle hydraulic system through the terminal, and the vehicle hydraulic system can determine the cylinder contraction instruction according to the received operation information.

[0143] See also Fig.11 , Fig.11 A control method for a vehicle hydraulic system according to an embodiment of the present application is shown. The present application embodiment provides control steps for a vehicle hydraulic system, including:

[0144] Step S201, obtaining a target retraction speed of a single-acting cylinder according to a cylinder retraction instruction;

[0145] Step S202, according to the speed interval to which the target contraction speed belongs, controlling the opening and closing states of the first valve and the second valve, so that the hydraulic oil in the single-acting cylinder flows into the oil tank through the independent oil circuit and / or the combined oil circuit.

[0146] The above two steps are described in detail below.

[0147] In step S201 , according to the acquired cylinder contraction instruction, the target contraction speed of the single-acting cylinder 231 indicated by the cylinder contraction instruction is acquired.

[0148] In step S202, the opening and closing states of the first valve 241 and the second valve 242 are determined according to the speed range of the target contraction speed. Since the opening and closing states of the first valve 241 and the second valve 242 are different, different target contraction speeds of the single-acting cylinder 231 can be achieved.

[0149] See also Fig.12 , Fig.12 A flow chart of controlling the opening and closing states of the first valve and the second valve according to the speed interval to which the target contraction speed belongs according to an embodiment of the present application is shown. The embodiment of the present application provides a step S202 of controlling the opening and closing states of the first valve and the second valve according to the speed interval to which the target contraction speed belongs, including:

[0150] Step S2021a, if the target contraction speed is within the first speed range, the first valve is controlled to be opened and the second valve is controlled to be closed, so that the hydraulic oil in the single-acting cylinder flows to the oil tank through the merging oil path;

[0151] Step S2022a, if the target contraction speed is within the second speed interval, the first valve is controlled to be closed and the second valve is controlled to be opened, so that the hydraulic oil in the single-acting cylinder flows to the oil tank through the independent oil path, and the minimum value of the second speed interval is greater than the maximum value of the first speed interval;

[0152] Step S2023a, if the target contraction speed is within the third speed range, open the first valve and the second valve to allow the hydraulic oil in the single-acting cylinder to flow to the oil tank via the combined oil circuit and the independent oil circuit, and the minimum value of the third speed range is greater than the maximum value of the second speed range.

[0153] The above three steps are described in detail below.

[0154] In step S2021, if the target retraction speed is within the first speed range, the first valve 241 is controlled to be opened and the second valve 242 is controlled to be closed, so that the hydraulic oil in the single-acting cylinder 231 flows to the oil tank 210 via the combined oil circuit. This is because the pipe diameter of the combined oil circuit is smaller than the pipe diameter of the independent oil circuit, that is, the return oil speed of the combined oil circuit is slower than that of the independent oil circuit. Therefore, when the target retraction speed is within the first speed range, only the first valve 241 is opened and the second valve 242 is closed to achieve slow retraction of the single-acting cylinder 231.

[0155] In step S2022, if the target contraction speed is within the second speed range, the first valve 241 is controlled to be closed and the second valve 242 is controlled to be opened, so that the hydraulic oil in the single-acting cylinder 231 flows to the oil tank 210 through an independent oil circuit, thereby realizing medium-speed contraction of the single-acting cylinder 231, and the minimum value of the second speed range is greater than the maximum value of the first speed range.

[0156] In step S2203, if the target contraction speed is within the third speed range, the first valve 241 and the second valve 242 are opened to allow the hydraulic oil in the single-acting cylinder 231 to flow to the oil tank 210 via the combined oil circuit and the independent oil circuit, thereby realizing rapid contraction of the single-acting cylinder 231, and the minimum value of the third speed range is greater than the maximum value of the second speed range.

[0157] In an embodiment of the present application, the target contraction speed of the single-acting cylinder 231 is determined by the cylinder contraction instruction, and then the opening and closing states of the first valve 241 and the second valve 242 are determined according to the target contraction speed of the single-acting cylinder 231, so that the single-acting cylinder 231 contracts at its target contraction speed.

[0158] In some embodiments, before controlling the opening and closing of the first valve 241 and / or the second valve 242 according to the speed range to which the target contraction speed belongs, the first speed range, the second speed range, and the third speed range are determined according to the pipe diameters of the independent oil circuit and the merged oil circuit, wherein the minimum value of the second speed range is greater than the maximum value of the first speed range, and the minimum value of the third speed range is greater than the maximum value of the second speed range.

[0159] For details, please refer to Fig.13 , Fig.13 A flow chart of determining each speed interval according to an embodiment of the present application is shown. The embodiment of the present application provides steps for determining each speed interval, including:

[0160] Step S301, calculating the maximum pipeline flow of the independent oil circuit and the merged oil circuit according to the pipeline diameters of the independent oil circuit and the merged oil circuit and the pressure at the interface of the single-acting cylinder, wherein the pipeline diameter of the independent oil circuit is greater than the pipeline diameter of the merged oil circuit;

[0161] Step S302, the target contraction speed of the single-acting cylinder when working at the maximum pipeline flow rate of the combined oil circuit is a first contraction speed, and the target contraction speed of the single-acting cylinder when working at the maximum pipeline flow rate of the independent oil circuit is a second contraction speed;

[0162] Step S303, determining a first speed interval, a second speed interval, and a third speed interval according to the first contraction speed and the second contraction speed; wherein,

[0163] The first speed interval is greater than zero and less than or equal to the first contraction speed;

[0164] The second speed interval is greater than the first contraction speed and less than or equal to the second contraction speed;

[0165] The third speed interval is greater than the second contraction speed, and less than or equal to the sum of the first contraction speed and the second contraction speed.

[0166] The above three steps are described in detail below.

[0167] In step S301, since the oil return speed of the independent oil circuit and the confluent oil circuit depends on the pipeline diameter and the pressure difference between the hydraulic oil at the single-acting cylinder 231 and the oil tank 210, the maximum pipeline flow of the independent oil circuit and the confluent oil circuit is calculated according to the pipeline diameter of the independent oil circuit and the confluent oil circuit and the pressure at the interface of the single-acting cylinder 231. The pipeline diameter of the independent oil circuit is greater than the pipeline diameter of the confluent oil circuit. The pipeline flow refers to the oil output of the pipeline per unit time.

[0168] It should be made clear that in order to prevent the oil discharge speed of the single-acting cylinder 231 from being affected by the size of the interface of the single-acting cylinder 231, the size of the interface of the single-acting cylinder 231 is set to be greater than or equal to the pipe diameter of the independent oil circuit. If the size of the interface of the single-acting cylinder 231 is smaller than the pipe diameter of the independent oil circuit, the size of the interface of the single-acting cylinder 231 is used as the pipe diameter of the independent oil circuit. Similarly, if the size of the interface of the single-acting cylinder 231 is smaller than the pipe diameter of the merged oil circuit, the size of the interface of the single-acting cylinder 231 is used as the pipe diameter of the merged oil circuit and the independent oil circuit.

[0169] In step S302, the target contraction speed of the single-acting cylinder 231 when working at the maximum pipeline flow rate of the merged oil circuit is the first contraction speed, and the target contraction speed of the single-acting cylinder 231 when working at the maximum pipeline flow rate of the independent oil circuit is the second contraction speed.

[0170] In step S303, the first speed interval, the second speed interval, and the third speed interval are determined according to the first contraction speed and the second contraction speed; wherein the first speed interval is greater than zero and less than or equal to the first contraction speed; the second speed interval is greater than the first contraction speed and less than or equal to the second contraction speed; the third speed interval is greater than the second contraction speed and less than or equal to the sum of the first contraction speed and the second contraction speed. That is, the target contraction speed of the first speed interval can be completely achieved by only opening the first valve 241 and returning oil through the merging oil circuit. The target contraction speed of the second speed interval can be achieved by only opening the second valve 242 and returning oil through the independent oil circuit.

[0171] In some embodiments, as long as the target retraction speed is in the first speed interval, only the first valve 241 is opened to make the single-acting cylinder 231 retract at the first retraction speed without fine division. Similarly, as long as the target retraction speed is in the second speed interval, only the second valve 242 is opened to make the single-acting cylinder 231 retract at the second retraction speed without fine division. As long as the target retraction speed is in the third speed interval, the first valve 241 and the second valve 242 are opened at the same time to make the single-acting cylinder 231 retract at the sum of the first retraction speed and the second retraction speed, so as to realize the three-stage speed change of the retraction of the single-acting cylinder 231, so as to cope with the situation that different target retraction speeds are required under different working conditions.

[0172] In some embodiments, the combined oil circuit is provided with a first throttle valve, which is used to control the pipeline flow of the combined oil circuit. The independent oil circuit is provided with a second throttle valve, which is used to control the pipeline flow of the independent oil circuit. According to different target contraction speeds indicated by the contraction designation, precise control of the actual target contraction speed of the single-acting cylinder 231 is achieved by controlling the first throttle valve and the second throttle valve.

[0173] For details, please refer to Fig.14 , Fig.14 A flow chart of accurately controlling the target retraction speed of a single-acting cylinder according to an embodiment of the present application is shown. The present application embodiment provides steps for accurately controlling the target retraction speed of a single-acting cylinder, including:

[0174] Step S401, obtaining a target retraction speed of a single-acting cylinder according to the content indicated by the cylinder retraction instruction;

[0175] Step S402, calculating the required discharge flow rate of the single-acting cylinder according to the target contraction speed and the internal space parameters of the single-acting cylinder;

[0176] Step S403, if the target contraction speed is in the first speed range, the first valve is opened, the second valve is closed, and the first throttle valve is adjusted to adjust the pipeline flow of the merging oil circuit to the discharge flow;

[0177] Step S404, if the target contraction speed is in the second speed range, the first valve is closed, the second valve is opened, and the second throttle valve is adjusted to adjust the pipeline flow of the independent oil circuit to the discharge flow;

[0178] Step S405, if the target contraction speed is in the third speed range, the first valve and the second valve are opened, and the first throttle valve and / or the second throttle valve are adjusted to adjust the sum of the pipeline flow of the independent oil circuit and the merged oil circuit to the discharge flow.

[0179] The above three steps are described in detail below.

[0180] In step S401 , according to the content indicated by the cylinder contraction instruction, the target contraction speed of the single-acting cylinder 231 indicated by the cylinder contraction instruction is obtained, and the content indicated by the cylinder contraction instruction includes the target contraction speed of the single-acting cylinder 231 .

[0181] In step S402, the required discharge flow rate of the single-acting cylinder 231 is calculated according to the target retraction speed and the internal space parameter of the single-acting cylinder 231. The internal parameter of the single-acting cylinder 231 refers to the volume of the internal space of the single-acting cylinder 231, so as to determine how much discharge flow rate the single-acting cylinder 231 needs to achieve the target retraction speed indicated by the cylinder retraction instruction.

[0182] In step S403, if the target retraction speed is in the first speed range, the first valve 241 is opened, the second valve 242 is closed, and the first throttle valve is adjusted to adjust the pipeline flow of the combined oil circuit to the discharge flow, so that the target retraction speed of the single-acting oil cylinder 231 reaches the target retraction speed.

[0183] In step S404, if the target contraction speed is in the second speed range, the first valve 241 is closed, the second valve 242 is opened, and the second throttle valve is adjusted to adjust the pipeline flow of the independent oil circuit to the discharge flow, so that the target contraction speed of the single-acting cylinder 231 reaches the target contraction speed.

[0184] In step S405, if the target contraction speed is in the third speed range, the first valve 241 and the second valve 242 are opened, and the first throttle valve and / or the second throttle valve are adjusted to adjust the sum of the pipeline flow rates of the independent oil circuit and the merged oil circuit to the discharge flow rate, so that the target contraction speed of the single-acting cylinder 231 reaches the target contraction speed.

[0185] In the embodiment of the present application, the target retraction speed of the single-acting cylinder 231 is precisely controlled by setting a throttle valve, so that the vehicle hydraulic system can meet more user needs and the single-acting cylinder 231 meets the conditions for fine operations.

[0186] See also Fig.15 , Fig.15 A flow chart of controlling the opening and closing states of the first valve and the second valve according to the cylinder retraction instruction according to another embodiment of the present application is shown. The present application embodiment provides a step S202 of controlling the opening and closing states of the first valve and the second valve according to the cylinder retraction instruction, including:

[0187] S2021b, determining the maximum pipeline flow rate of the independent oil circuit and the combined oil circuit according to the pipeline diameters of the independent oil circuit and the combined oil circuit and the pressure at the interface of the single-acting cylinder;

[0188] S2022b, obtaining a target retraction speed of the single-acting cylinder according to the content indicated by the cylinder retraction instruction;

[0189] S2023b, calculating the required discharge flow rate of the single-acting cylinder according to the target contraction speed and the internal space parameters of the single-acting cylinder;

[0190] S2024b, according to the maximum pipeline flow rates of the merged oil circuit and the independent oil circuit, select at least one target oil circuit from the merged oil circuit and the independent oil circuit to transport the hydraulic oil in the single-acting cylinder back to the oil tank, and the sum of the maximum pipeline flow rates of the target oil circuits is greater than or equal to the discharge flow rate.

[0191] The above four steps are described in detail below.

[0192] In step S2021b, the maximum pipeline flow rates of the independent oil circuits and the combined oil circuits are determined according to the pipeline diameters of the independent oil circuits and the combined oil circuits and the pressure at the interface of the single-acting oil cylinder 231. For details, please refer to step S402.

[0193] In step S2022b, the target retraction speed of the single-acting cylinder 231 is obtained according to the content indicated by the cylinder retraction instruction.

[0194] In step S2023 b , the required discharge flow rate of the single-acting cylinder 231 is calculated based on the target contraction speed and the internal space parameters of the single-acting cylinder 231 .

[0195] In step S2024b, at least one target oil circuit is selected from the merged oil circuit and the independent oil circuit based on the maximum pipeline flow rates of the merged oil circuit and the independent oil circuit, and the hydraulic oil in the single-acting cylinder 231 is transported back to the oil tank 210, and the sum of the maximum pipeline flow rates of the target oil circuits is greater than or equal to the discharge flow rate.

[0196] In some embodiments, there are multiple independent oil circuits, and the maximum pipeline flow rates of the multiple independent oil circuits are the same.

[0197] In some embodiments, there are multiple independent oil circuits, and the maximum pipeline flow rate of each independent oil circuit is different.

[0198] In some embodiments, when determining the discharge flow required by the single-acting cylinder 231, if there is a merged oil circuit or an independent oil circuit with a maximum pipeline flow greater than or equal to the discharge flow, the merged oil circuit or the independent oil circuit with a maximum pipeline flow greater than or equal to the discharge flow is determined as the target oil circuit. If there are multiple target oil circuits, only the target oil circuit with the maximum discharge flow closest to the discharge flow is retained.

[0199] In some embodiments, if there is no merged oil circuit or independent oil circuit with a maximum pipeline flow greater than or equal to the discharge flow, then N oil circuits whose sum of maximum pipeline flow is greater than the discharge flow are taken as the target oil circuit group, where N is greater than or equal to 2. If there are multiple target oil circuit groups, only the target oil circuit group with the smallest N is retained, and the oil circuits in the target oil circuit group are the target oil circuits.

[0200] If there are multiple target oil circuit groups with the smallest N, only the target oil circuit group with the maximum discharge flow rate closest to the discharge flow rate is retained.

[0201] The following is the application of the vehicle hydraulic system and its control method in a garbage truck.

[0202] See also Fig.16 , Fig.16 The schematic diagram of the structure of a garbage truck according to an embodiment of the present application is shown. The garbage truck may include: a front 120 and a body 110, wherein the front 120 is used for driving by a driver. The body 110 includes a frame 111 connected to the front 120 and a box 112 disposed on the frame 111. The frame 111 is used to carry the box 112.

[0203] It should be clear that in the embodiments of the present application, the garbage truck can apply the liquid system described in each embodiment of this document.

[0204] In some embodiments, the single-acting cylinder 231 is disposed between the vehicle box and the vehicle body and is used to push the vehicle box so that the vehicle box can be flipped relative to the vehicle frame.

[0205] Exemplarily, a box lifting assembly 330 is provided in the garbage truck, and the box lifting assembly 330 includes a single-acting cylinder 231. The box lifting assembly is driven by the single-acting cylinder 231 and cooperates with the single-acting cylinder 231 to lift and lower the vehicle box 112.

[0206] For details, please refer to Fig.16 and Fig.17 , Fig.17 1 shows a schematic structural diagram of a garbage truck according to another embodiment of the present application. The vehicle box 112 may include a box body 1121, the rear end of which is rotatably connected to the rear end of the frame 111, and the front end of the box body 1121 can rotate around the rotation axis of the rear end of the box body 1121. The box body lifting assembly 330 is disposed on the frame 111, and the box body lifting assembly 330 is connected to the box body 1121 so as to be able to lift the box body 1121.

[0207] The box lifting assembly 330 may include a single-acting cylinder 231. One end of the single-acting cylinder 231 is disposed on the vehicle frame 111, and the other end is rotatably connected to the front end of the box 1121. The single-acting cylinder 231 can lift and support the front end of the box 1121, so that the box 1121 rotates around the rotation axis of the rear end of the box 1121, thereby realizing the dumping of garbage in the box 1121 and improving the garbage disposal efficiency.

[0208] The cylinder body of the single-acting cylinder 231 is rotatably connected to the front end of the box 1121, and the telescopic end of the single-acting cylinder 231 is rotatably connected to the frame 111. The telescopic end of the single-acting cylinder 231 extends to lift the box 1121 to dump garbage, and the telescopic end of the single-acting cylinder 231 contracts to place the box 1121 on the frame 111 to receive the garbage.

[0209] In some embodiments, the box lifting assembly 330 may further include a single-acting cylinder support 331 and a sub-frame 332. The single-acting cylinder support 331 is fixedly connected to the front end surface of the box 1121, and the single-acting cylinder support 331 is rotatably connected to the cylinder body of the single-acting cylinder 231. The sub-frame 332 is fixedly connected to the front end of the frame 111, and the sub-frame 332 is rotatably connected to the telescopic end of the single-acting cylinder 231, so that when the single-acting cylinder 231 supports the box 1121, the weight of the box 1121 and the garbage can be evenly transferred to the frame 111 through the sub-frame 332, thereby ensuring the structural strength and reliability of the vehicle body 110.

[0210] In other embodiments, the single-acting cylinder support 331 is disposed at the lower portion of the front end surface of the box 1121 to prevent the box 1121 from colliding with the single-acting cylinder 231 during lifting, thereby improving the safety and reliability of the single-acting cylinder 231 .

[0211] In the above embodiment, since the single-acting cylinder 231 can achieve multi-stage speed change of the retraction speed, the box body 1121 of the garbage truck can also control the descending speed to meet the user's control requirements, while allowing the garbage truck to be applied to more scenarios.

[0212] In some embodiments, based on the description of the hydraulic system, a plurality of double-acting cylinders may be provided in the garbage truck to achieve different functions.

[0213] See also Fig.15 and Fig.17 In this embodiment, the vehicle box 112 may further include a top cover 1122 and a tailgate 1223. A loading port 11211 is provided at the upper portion of the front end of the box body 1121, a discharge port 11212 is provided at the rear end of the box body 1121, the top cover 1122 can be opened and closed to cover the loading port 11211, and the tailgate 1223 can be opened and closed to cover the discharge port 11212.

[0214] In this embodiment, the box body 1121 may include a compression bin 11213 located at the front end of the box body 1121 and a storage bin 11214 located at the rear end of the box body 1121, and a delivery port 11211 is provided at the upper portion of the compression bin 11213. The storage bin 11214 is connected to the compression bin 11213. When garbage enters the compression bin 11213 through the delivery port 11211, the garbage is compressed in the compression bin 11213 and then input into the storage bin 11214 for storage, so as to improve the space utilization rate of the garbage truck and improve the garbage collection efficiency.

[0215] Fig.18 A partial structural schematic diagram of a box body, a top cover, and a top cover opening and closing assembly according to an embodiment of the present application is shown. Fig.19 A partial structural schematic diagram of a box body, a tailgate, and a tailgate opening and closing assembly according to an embodiment of the present application is shown. Fig. 20 A partial structural schematic diagram of a box body and a garbage compression assembly according to an embodiment of the present application is shown.

[0216] See also Figures 16 to 20In this embodiment, the garbage truck may include a top cover opening and closing assembly 310 for opening and closing the top cover 1122, a tailgate opening and closing assembly 320 for opening and closing the tailgate 1223, and a compression assembly 340 for compressing garbage. The top cover opening and closing assembly 310 may be disposed in the box body 1121 to drive the top cover to open and close the delivery port 11211. The tailgate opening and closing assembly 320 is disposed in the box body 1121 to drive the tailgate 1223 to open and close the discharge port 11212.

[0217] The compression assembly 340 includes a compression cylinder 2321, which is driven by the compression cylinder 2321 and cooperates with other parts of the garbage compression assembly 340 to compress the garbage. The top cover opening and closing assembly 310 includes a top cover cylinder 2323, which is driven by the top cover cylinder 2323 and cooperates with other parts of the top cover opening and closing assembly 310 to open and close the top cover 1122. The tailgate opening and closing assembly 320 includes a tailgate cylinder 2322, which is driven by the tailgate cylinder 2322 and cooperates with other parts of the tailgate opening and closing assembly 320 to open and close the tailgate 1223.

[0218] When the garbage truck is collecting garbage, the top cover opening and closing assembly 310 opens the top cover 1122 and pours the garbage in the garbage can 90 into the box body 1121 through the delivery port 11211. When the garbage truck dumps the garbage, the tailgate opening and closing assembly 320 can drive the tailgate 1223 to open the discharge port 11212, and the garbage compression assembly 340 compresses the garbage in the box body to improve the compression efficiency of the garbage, thereby improving the space utilization rate in the box body 1121, so as to facilitate the compression and transportation of the garbage.

[0219] See also Fig.16 , Fig.17 , Fig.18 and Fig. 20 In this embodiment, the top cover opening and closing assembly 310 may include a top cover support 311, a bending member 312, a top cover cylinder support 313 and a top cover cylinder 2323. The top cover support 311 is arranged on the side wall of the storage bin 11214. The bending member 312 is hinged on the top cover support 311 so that the bending member 312 can rotate around the top cover support 311. The top cover cylinder support 313 is arranged on the side wall of the storage bin 11214, the top cover cylinder support 313 is hinged to the cylinder body of the top cover cylinder 2323, and the rotation axis of the top cover cylinder 2323 is arranged parallel to the rotation axis of the bending member 312. The telescopic end of the top cover cylinder 2323 is hinged to the bending piece 312 , so that the top cover cylinder 2323 can push the bending piece 312 and the top cover 1122 to rotate around the top cover support 311 , thereby opening and closing the drop-in port 11211 .

[0220] When the car box 112 collects garbage, the telescopic end of the top cover cylinder 2323 extends out, the top cover cylinder 2323 rotates around the top cover cylinder support 313, and the bending part 312 and the top cover 1122 rotate around the top cover support 311, so that the top cover 1122 opens and the garbage can enter the box body 1121 through the delivery port 11211.

[0221] In some embodiments, the top cover support 311 is disposed on the front side wall and / or the rear side wall of the compression chamber 11213, and is located at the compression chamber 11213 away from the delivery port 11211, and the rotation axis of the bending member 312 extends in the front-to-back direction. The top cover cylinder support 313 is disposed on the front side wall and / or the rear side wall of the compression chamber 11213, and is located on the side of the top cover support 311 away from the delivery port 11211, and the rotation axis of the top cover cylinder 2323 extends in the front-to-back direction. In the up-down direction, the top cover cylinder support 313 is located below the top cover support 311, so that the top cover cylinder 2323 can open and close the top cover 1122.

[0222] When the telescopic end of the top cover cylinder support 313 is extended, the top cover cylinder 2323 rotates around the top cover cylinder support 313, the bending part 312 rotates around the top cover support 311 close to the delivery port 11211, and the top cover 1122 rotates upward around the top cover support 311 to open the delivery port 11211. In addition, the top cover 1122 can be kept away from the delivery port 11211 to prevent garbage from falling onto the top cover 1122 when dumping, thereby preventing the garbage from affecting the opening and closing of the top cover 1122, ensuring the safety and stability of the top cover opening and closing assembly 310, and improving the opening and closing efficiency of the top cover 1122.

[0223] In some embodiments, the top cover cylinder 2323 may be a double-acting cylinder with a single piston rod, which can realize reciprocating movement of the telescopic end, thereby realizing the opening and closing of the top cover 1122.

[0224] See also Fig.16 , Fig.17 , Fig.19 In this embodiment, the upper portion of the tailgate 1223 is hinged to the upper portion of the rear end of the box body 1121. The tailgate opening and closing assembly 320 is disposed between the rear end of the box body 1121 and the tailgate 1223, so as to drive the tailgate 1223 to rotate close to the box body 1121 to close the discharge port 11212 or to drive the tailgate 1223 to rotate away from the box body 1121 to open the discharge port 11212, thereby reducing manual intervention, improving the safety of the garbage truck, and effectively improving work efficiency.

[0225] The tailgate opening and closing assembly 320 may include a tailgate cylinder 2322. The cylinder body of the tailgate cylinder 2322 is hinged to the lower part of the box body 1121, and the telescopic end of the tailgate cylinder 2322 is hinged to the upper part of the tailgate 1223. When the telescopic end of the tailgate cylinder 2322 is extended, the tailgate cylinder 2322 rotates to be able to abut against the tailgate 1223, so that the lower part of the tailgate 1223 rotates away from the box body 1121, thereby opening the discharge port 11212. When the telescopic end of the tailgate cylinder 2322 is retracted, the tailgate cylinder 2322 rotates to be able to pull the tailgate 1223, so that the lower part of the tailgate 1223 rotates toward the box body 1121, thereby closing the discharge port 11212.

[0226] In some embodiments, the tailgate cylinder 2322 may be a double-acting cylinder with a single piston rod, which can achieve reciprocating movement of the telescopic end, thereby achieving the opening and closing of the tailgate 1223 .

[0227] See also Fig.16 , Fig.17 and Fig. 20 In this embodiment, a locking rod 321 may be provided on the tailgate 1223. The locking rod 321 is located on the side of the tailgate 1223 facing the box body 1121, and the locking rod 321 extends in left and right directions, and both ends of the locking rod 321 are fixedly connected to the tailgate 1223 respectively.

[0228] The tailgate opening and closing assembly 320 may further include a locking slider 322. The locking slider 322 is slidably disposed at the rear end of the box body 1121 and is located at the lower side of the discharge port 11212. The upper portion of the locking slider 322 is hinged to the cylinder body of the tailgate cylinder 2322 so that the tailgate cylinder 2322 can drive the locking slider 322 to move up and down when the tailgate cylinder 2322 is extended or retracted. In the front-to-back direction, a locking bevel 3221 is recessed on a side wall of the locking slider 322 that is away from the box body 1121 relative to the locking rod 321. In a plane perpendicular to the left-right direction, the locking bevel 3221 extends downwardly at an angle.

[0229] When the tailgate 1223 is opened, the telescopic end of the tailgate cylinder 2322 extends out, the locking slider 322 slides downward, the lower part of the tailgate 1223 rotates upward, the locking rod 321 escapes from the locking chute 3221, and the discharge port 11212 opens, so that the garbage in the box 1121 can be discharged through the discharge port 11212.

[0230] When the tailgate 1223 is closed, the telescopic end of the tailgate cylinder 2322 contracts, the locking slider 322 slides upward, the lower part of the tailgate 1223 rotates downward, the locking rod 321 rotates into and abuts against the bottom of the locking inclined groove 3221, so that the locking rod 321 is limited on the locking slider 322, and the tailgate 1223 covers the rear end of the box body 1121 to close the discharge port 11212, thereby reducing labor costs and improving the opening and closing efficiency of the vehicle box 112.

[0231] In some embodiments, the tailgate opening and closing assembly 320 may further include a support latch 323. The lower end of the support latch 323 is rotatably connected to the locking slider 322, and the upper end of the support latch 323 can rotate around the rotation axis of the lower end of the support latch 323 to switch between the supporting position and the folded position.

[0232] When the support latch 323 rotates to the supporting position, the upper end of the support latch 323 rotates in a direction away from the box body 1121, so that the upper end of the support latch 323 abuts against and supports the tailgate 1223, thereby preventing the tailgate 1223 from being accidentally closed and causing safety hazards. When the support latch 323 rotates to the folding position, the support latch 323 is away from the tailgate 1223, so that the tailgate 1223 can cover the rear end of the box body 1121.

[0233] In some embodiments, the tailgate opening and closing assembly 320 may further include a sealing strip (not shown). The sealing strip is disposed at the rear end of the box body 1121 and is disposed around the outer periphery of the discharge port 11212. The sealing strip can be in sealing contact with the tailgate 1223 to improve the sealing performance of the vehicle box 112, prevent liquid garbage from leaking to the outside, and improve the environmental performance of the garbage truck.

[0234] Fig. 20 It is a partial structural schematic diagram of the box body and the garbage compression assembly of the present invention.

[0235] See also Fig. 20 In this embodiment, the garbage compression assembly 340 may include a compression cylinder 2321 and a compression head 341. The compression cylinder 2321 and the compression head 341 are both located in the box 1121 to compress the garbage entering the box 1121 through the delivery port 11211, reduce the space occupied by the garbage, improve the space utilization of the box 1121, and thus improve the garbage transportation efficiency.

[0236] The cylinder body of the compression cylinder 2321 is connected to the box body 1121 , and the telescopic end of the compression cylinder 2321 is connected to the compression head 341 , so that the compression cylinder 2321 can push the compression head 341 to compress the garbage in the box body 1121 .

[0237] In some embodiments, the garbage compression assembly 340 can be disposed in the compression bin 11213. The compression cylinder 2321 extends in the front-to-back direction. The cylinder body of the compression cylinder 2321 is connected to the front end wall of the compression bin 11213, and the telescopic end of the compression cylinder 2321 can be telescoped backward. The telescopic end of the compression cylinder 2321 is connected to the compression head 341, so that the head 341 can be pushed backward and the garbage is compressed, and the garbage is pushed into the storage bin 11214.

[0238] In some embodiments, the garbage compression assembly 340 may further include a guide plate 342. The guide plate 342 is disposed in the compression chamber 11213, and is disposed opposite to the delivery port 11211 and is located on the upper side of the compression cylinder 2321. In the direction from top to bottom, the guide plate 342 extends obliquely from front to rear, and the guide plate 342 can receive and guide the garbage poured into the delivery port 11211, so as to facilitate the reciprocating movement of the compression head 341 to compress the garbage.

[0239] In some embodiments, when the compression cylinder 2321 contracts, the rear end of the guide plate 342 extends backward beyond the compression head 341 or is flush with the compression head 341, so that the garbage guided by the guide plate 342 falls into the rear side of the compression head 341, so as to improve the compression efficiency of the garbage, thereby improving the space utilization in the box 1121, so as to facilitate the compression and transportation of the garbage.

[0240] Those skilled in the art will readily appreciate other embodiments of the present application after considering the specification and practicing the embodiments disclosed herein. The present application is intended to cover any variations, uses or adaptations of the present application, which follow the general principles of the present application and include common knowledge or customary technical means in the art that are not disclosed in the present application.

[0241] It should be understood that the above content is only a preferred exemplary embodiment of the present application and is not intended to limit the implementation scheme of the present application. A person skilled in the art can easily make corresponding changes or modifications based on the main concept and spirit of the present application. Therefore, the scope of protection of the present application shall be based on the scope of protection required by the claims.

Claims

1. A vehicle hydraulic system, characterized in that: The vehicle hydraulic system comprises: Oil tank, used to store hydraulic oil; An oil pump, used to extract the hydraulic oil in the oil tank and transport it; Single-acting cylinders are used to extend and retract according to the pressure of the hydraulic oil in the single-acting cylinder to push the load; A confluent oil circuit, a first end of which is in communication with an interface of the single-acting oil cylinder, and a first valve is disposed on the confluent oil circuit; a first multi-way valve, the first multi-way valve being in communication with the second end of the combined oil circuit, and the first multi-way valve being used to control the second end of the combined oil circuit to be in communication with the output end of the oil pump or the input end of the oil tank; An independent oil circuit, the input end of the independent oil circuit is arranged between the first end of the merged oil circuit and the first valve, the output end of the independent oil circuit is connected to the input end of the oil tank, a second valve is provided on the independent oil circuit, and the independent oil circuit is used to transport the hydraulic oil in the single-acting cylinder to the oil tank.

2. The vehicle hydraulic system according to claim 1, characterized in that: The vehicle hydraulic system is further provided with a third valve, and two ends of the third valve are respectively connected to two sides of the second valve.

3. The vehicle hydraulic system according to claim 1, characterized in that: The first interface of the first multi-way valve is communicated with the second end of the merged oil circuit, the second interface of the first multi-way valve is communicated with the output end of the oil pump, and the third interface of the first multi-way valve is communicated with the input end of the oil tank; Wherein, when the first interface of the first multi-way valve is connected only to the second interface of the first multi-way valve, the second end of the combined oil circuit is connected to the output end of the oil pump via the first multi-way valve, and the hydraulic oil in the oil tank can be delivered to the single-acting oil cylinder; When the first interface of the first multi-way valve is connected only to the third interface of the first multi-way valve, the second end of the merged oil circuit is connected to the input end of the oil tank via the first multi-way valve, and the hydraulic oil in the single-acting cylinder can be delivered to the oil tank.

4. The vehicle hydraulic system according to claim 1, characterized in that: The vehicle hydraulic system is provided with a double-acting cylinder, the double-acting cylinder is provided with a first interface and a second interface, and the piston in the double-acting cylinder moves between the first interface and the second interface of the double-acting cylinder to drive the piston rod connected to the piston to move; The vehicle hydraulic system is further provided with a second multi-way valve, a first interface of the second multi-way valve is communicated with a first interface of the double-acting oil cylinder, a second interface of the second multi-way valve is communicated with a second interface of the double-acting oil cylinder, a third interface of the second multi-way valve is communicated with an output end of the oil pump, and a fourth interface of the second multi-way valve is communicated with an input end of the oil tank; The first interface of the second multi-way valve is connected to the third interface of the second multi-way valve, and the second interface of the second multi-way valve is connected to the fourth interface of the second multi-way valve, so that the first interface of the double-acting oil cylinder is connected to the output end of the oil pump, and the second interface of the double-acting oil cylinder is connected to the input end of the oil tank, and the piston in the double-acting oil cylinder moves toward the second interface of the double-acting oil cylinder, and the piston rod extends; The first interface of the second multi-way valve is connected with the fourth interface of the second multi-way valve, and the second interface of the second multi-way valve is connected with the third interface of the second multi-way valve, so that the first interface of the double-acting cylinder is connected with the input end of the oil tank, and the second interface of the double-acting cylinder is connected with the output end of the oil pump, the piston in the double-acting cylinder moves toward the first interface of the double-acting cylinder, and the piston rod retracts.

5. The vehicle hydraulic system according to claim 1 or 4, characterized in that: The oil pump is a load-sensitive oil pump, the first multi-way valve and the second multi-way valve are load-sensitive proportional valves, the load-sensitive oil pump and the load-sensitive proportional valve are signal-connected, the load-sensitive proportional valve controls the rotation speed of the oil pump according to the acquired load oil pressure to control the pressure difference between the load oil pressure and the output oil pressure of the load-sensitive oil pump, the load oil pressure includes the oil pressure in the single-acting cylinder and the oil pressure in the double-acting cylinder.

6. A method for controlling a vehicle hydraulic system, applied to the vehicle hydraulic system according to any one of claims 1 to 5, characterized in that: The control method comprises: According to the received cylinder contraction instruction, the opening and closing states of the first valve and the second valve are controlled so that the hydraulic oil in the single-acting cylinder flows into the oil tank via at least one of the independent oil circuit and the combined oil circuit.

7. The control method according to claim 6, characterized in that: The control method further comprises: According to the cylinder retraction instruction, a target retraction speed of the single-acting cylinder is obtained; According to the speed range to which the target contraction speed belongs, the opening and closing states of the first valve and the second valve are controlled so that the hydraulic oil in the single-acting cylinder flows into the oil tank via the independent oil circuit and / or the combined oil circuit.

8. The control method according to claim 7, characterized in that: According to the speed interval to which the target contraction speed belongs, controlling the opening and closing states of the first valve and the second valve includes: If the target contraction speed is within the first speed range, the first valve is controlled to be opened and the second valve is controlled to be closed, so that the hydraulic oil in the single-acting cylinder flows to the oil tank via the combined oil path; If the target contraction speed is within a second speed interval, the first valve is controlled to be closed and the second valve is controlled to be opened, so that the hydraulic oil in the single-acting cylinder flows to the oil tank via the independent oil path, and the minimum value of the second speed interval is greater than the maximum value of the first speed interval; If the target contraction speed is within a third speed range, the first valve and the second valve are opened to allow the hydraulic oil in the single-acting cylinder to flow to the oil tank via the merged oil circuit and the independent oil circuit, and the minimum value of the third speed range is greater than the maximum value of the second speed range.

9. The control method according to claim 7, characterized in that: According to the speed interval to which the target contraction speed belongs, controlling the opening and closing states of the first valve and the second valve, the control method further includes: According to the pipe diameters of the independent oil circuit and the merged oil circuit, the speed interval is divided into a first speed interval, a second speed interval, and a third speed interval; wherein the minimum value of the second speed interval is greater than the maximum value of the first speed interval, and the minimum value of the third speed interval is greater than the maximum value of the second speed interval.

10. The control method according to claim 9, characterized in that: According to the pipe diameters of the independent oil circuit and the merged oil circuit, the speed interval is divided into a first speed interval, a second speed interval, and a third speed interval, including: Calculate the maximum pipeline flow of the independent oil circuit and the merged oil circuit according to the pipeline diameters of the independent oil circuit and the merged oil circuit and the pressure at the interface of the single-acting cylinder, the pipeline diameter of the independent oil circuit being greater than the pipeline diameter of the merged oil circuit; The target contraction speed of the single-acting cylinder when working at the maximum pipeline flow rate of the merged oil circuit is a first contraction speed, and the target contraction speed of the single-acting cylinder when working at the maximum pipeline flow rate of the independent oil circuit is a second contraction speed; A first speed interval, a second speed interval, and a third speed interval are determined according to the first contraction speed and the second contraction speed; wherein: The first speed interval is greater than zero and less than or equal to the first contraction speed; The second speed interval is greater than the first contraction speed, and less than or equal to the second contraction speed; The third speed interval is greater than the second contraction speed, and less than or equal to the sum of the first contraction speed and the second contraction speed.

11. The control method according to claim 6, characterized in that: According to the received cylinder retraction instruction, the opening and closing states of the first valve and the second valve are controlled, including: Determine the maximum pipeline flow of the independent oil circuit and the merged oil circuit according to the pipeline diameters of the independent oil circuit and the merged oil circuit and the pressure at the interface of the single-acting cylinder; According to the content indicated by the cylinder retraction instruction, a target retraction speed of the single-acting cylinder is obtained; Calculating the required discharge flow rate of the single-acting cylinder according to the target contraction speed and the internal space parameters of the single-acting cylinder; According to the maximum pipeline flow rates of the merged oil circuit and the independent oil circuit, at least one target oil circuit is selected from the merged oil circuit and the independent oil circuit to transport the hydraulic oil in the single-acting cylinder back to the oil tank, and the sum of the maximum pipeline flow rates of the target oil circuits is greater than or equal to the discharge flow rate.

12. A garbage truck, characterized in that: Applying the control method as described in any one of claims 6 to 11; The garbage truck comprises the vehicle hydraulic system, a vehicle body and a vehicle front, wherein the vehicle body comprises a vehicle box and a vehicle frame, and the single-acting cylinder is arranged between the vehicle box and the vehicle frame and is used to push the vehicle box so that the vehicle box flips relative to the vehicle frame.

13. The garbage truck according to claim 12, characterized in that: The double-acting cylinders in the vehicle hydraulic system are provided with one or more, which are used as one or more of the following cylinders, including: A compression cylinder, which is arranged in the garbage truck and is used to push and compress the garbage in the truck box; A tailgate cylinder, which is arranged in the garbage truck and is used to push the tailgate arranged on one side of the vehicle box to control the opening and closing of the tailgate; A top cover oil cylinder is arranged in the garbage truck and is used to push a top cover arranged at the loading port of the vehicle box to control the opening and closing of the loading port.

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