Tractor electric control brake system with liquid filling function and tractor

Abstract

The utility model relates to a tractor electric control brake system with liquid filling function and tractor, wherein, a tractor electric control brake system with liquid filling function, including oil tank, load sensitive pump, liquid filling valve, brake mechanism and power brake valve group, load sensitive pump's oil suction port communicates oil tank, and its oil outlet communicates liquid filling valve's oil inlet, brake mechanism includes energy accumulator, brake valve and brake, liquid filling valve's oil outlet communicates energy accumulator and power brake valve group's oil inlet, energy accumulator still communicates power brake valve group's oil inlet, brake valve's oil outlet communicates brake mouth of brake, power brake valve group oil outlet communicates first oil inlet of brake valve. The utility model can carry out electronic emergency brake or manual emergency brake under the condition of engine failure or pump failure, improves the security of brake.

Description

Technical Field

[0001] This utility model relates to the field of hydraulic system technology, and in particular to a tractor electric control braking system with fluid filling function and a tractor. Background Technology

[0002] With the modernization of agricultural machinery and the increasing demand for intelligent tractors, driverless tractors have become mainstream. However, currently, in the process of driverless CVT tractors, speed control can usually only perform passive braking, relying solely on the high-pressure overflow valve of the closed-loop system pump and motor in the CVT transmission for service braking. The service braking pressure controlled in this process is far from meeting the domestic braking requirement of a deceleration of 2.5 m / s^2, posing safety hazards and making the braking force uncontrollable. Addressing the shortcomings of existing tractors lacking active braking functions and unable to achieve electronic braking, some tractors can achieve active control through low-pressure switching valves. However, this control method lacks a good braking curve and braking force, especially in the event of engine or pump failure. In such cases, the safety and functionality of intelligent driving tractors are both deficient, resulting in a poor user experience. Utility Model Content

[0003] This utility model provides a tractor electronic braking system and tractor with fluid filling function, which can perform electronic emergency braking or manual emergency braking in the event of engine failure or pump failure, thereby improving braking safety.

[0004] The technical solution of this utility model to solve the above-mentioned technical problems is as follows: This utility model provides a tractor electronic braking system with a fluid filling function, including an oil tank, a load-sensitive pump, a fluid filling valve, a braking mechanism, and a power brake valve assembly for connection with the brake pedal. The oil inlet of the load-sensitive pump is connected to the oil tank, and its oil outlet is connected to the oil inlet of the fluid filling valve. The braking mechanism includes an accumulator, a brake valve, and a brake. The oil outlet of the fluid filling valve is connected to the oil inlet of the accumulator and the power brake valve assembly. The accumulator is also connected to the oil inlet of the power brake valve assembly. The oil outlet of the brake valve is connected to the brake port of the brake. The oil outlet of the power brake valve assembly is connected to the first oil inlet of the brake valve.

[0005] The beneficial effects of this utility model are as follows: When the vehicle starts, the accumulator is filled with oil through the load-sensitive pump. During driving, when the engine or pump fails, the driver can control the valve core of the power brake valve group to move by pressing the brake pedal according to the braking needs. The oil outlet of the power brake valve group is connected to the first oil inlet of the brake valve, and the oil outlet of the brake valve is connected to the brake port of the brake, so that the oil in the accumulator can flow into the control port of the brake, realizing the driving braking function in the manned driving mode. In the event of engine or pump failure, manual emergency braking can be performed, improving braking safety.

[0006] Based on the above technical solution, the present invention can be further improved as follows.

[0007] Furthermore, the outlet of the filling valve is also connected to the second inlet of the brake valve, and the accumulator is also connected to the second inlet of the brake valve. The brake valve can be switched to have its first inlet connected to its outlet, or its second inlet connected to its outlet.

[0008] Furthermore, the braking mechanism is provided in two sets, and the two brakes are respectively connected to the left and right rear axles of the tractor. The first oil outlet of the filling valve is connected to one of the accumulators, and the second oil outlet of the filling valve is connected to the other accumulator.

[0009] Furthermore, the power brake valve assembly includes two power brake valves. The first oil outlet of the filling valve is connected to the oil inlet of one of the power brake valves, and the second oil outlet of the filling valve is connected to the oil inlet of the other power brake valve. The oil outlets of the two power brake valves are respectively connected to the first oil inlets of the two brake valves, and both power brake valves can be switched to have their oil inlets and their oil outlets connected.

[0010] Furthermore, the power brake valve assembly also includes two pipelines corresponding to the two power brake valves respectively. Both power brake valves can be switched to disconnect their oil inlet from the oil inlet of the corresponding pipeline and disconnect their oil outlet from the oil outlet of the corresponding pipeline, or both power brake valves can be switched to connect their oil inlet to the oil inlet of the corresponding pipeline and connect their oil outlet to the oil outlet of the corresponding pipeline. Both pipelines are equipped with a check valve.

[0011] Furthermore, the two pipelines are simultaneously connected to a first pipeline section and a second pipeline section. Both ends of the first pipeline section are simultaneously connected to the oil inlet of the corresponding pipeline and the oil inlet of the one-way valve. Both ends of the second pipeline section are simultaneously connected to the oil outlet of the corresponding pipeline and the oil outlet of the one-way valve. A third pipeline section is simultaneously connected to the middle of the first pipeline section and the second pipeline section. A shuttle valve is configured at the middle end of the first pipeline section and the oil inlet end of the third pipeline section. The shuttle valve can be switched under oil pressure to connect the oil inlet of the third pipeline section to one of the pipelines.

[0012] Furthermore, the second pipe section is equipped with two throttle valves, and the oil inlets of both throttle valves are connected to the oil outlet of the third pipe section.

[0013] Furthermore, both of the power brake valves have a first working position and a second working position. The valve cores of both power brake valves can be moved to the first working position so that their oil inlet can be disconnected from their corresponding oil outlet, or moved to the second working position so that their oil inlet can be connected to their corresponding oil outlet.

[0014] Furthermore, the filling valve has an oil return port connected to the oil tank and a second load sensitive port connected to the first load sensitive port of the load sensitive pump, and the filling valve can be switched to have its oil return port and its second load sensitive port internally connected.

[0015] This utility model also provides a tractor, including a tractor electronic control braking system with a fluid filling function. Attached Figure Description

[0016] Figure 1 This is a diagram showing the oil circuit for charging the accumulator in the initial state of the tractor electronic control braking system of this utility model. Figure 2 This is the oil circuit diagram of the tractor electric control braking system of this utility model under manned braking. Figure 3 This is the oil circuit diagram of the tractor electric control braking system of this utility model under unmanned driving braking. Figure 4 This is a diagram of the oil circuit when the filling valve of the tractor's electronic braking system stops filling. Figure 5 For the present utility model Figure 4 Enlarged view of the power brake valve assembly.

[0017] The attached diagram lists the components represented by each number as follows: 1. Oil tank; 2. Load-sensitive pump; 3. Filling valve; 4. Accumulator; 5. Brake valve; 6. Brake; 7. Power brake valve assembly; 71. Power brake valve; 72. Pipeline; 73. Check valve; 74. First pipe section; 75. Second pipe section; 76. Third pipe section; 77. Shuttle valve; 78. Throttle valve. Detailed Implementation

[0018] The principles and features of this utility model are described below with reference to the accompanying drawings. The examples given are only for explaining this utility model and are not intended to limit the scope of this utility model.

[0019] This utility model provides a tractor electronic braking system with fluid filling function, as detailed below.

[0020] Example 1 like Figure 1 and Figure 2 A tractor electric braking system with a fluid filling function includes an oil tank 1, a load-sensitive pump 2, a fluid filling valve 3, a braking mechanism, and a power brake valve assembly 7 for connection with the brake pedal. The oil inlet (S port) of the load-sensitive pump 2 is connected to the oil tank 1, and its oil outlet (A3 port) is connected to the oil inlet (P3 port) of the fluid filling valve 3. The braking mechanism includes an accumulator 4, a brake valve 5, and a brake 6. The oil outlet of the fluid filling valve 3 is connected to the accumulator 4 and the oil inlet of the power brake valve assembly 7. The accumulator 4 is also connected to the oil inlet of the power brake valve assembly 7. The oil outlet (A5 port) of the brake valve 5 is connected to the brake port of the brake 6. The oil outlet of the power brake valve assembly 7 is connected to the first oil inlet (P1 port) of the brake valve 5.

[0021] The beneficial effects of this embodiment are as follows: When the vehicle starts, the accumulator 4 is filled with oil by the load-sensitive pump 2. During driving, when the engine or pump fails, the driver can control the valve core of the power brake valve group 7 to move by pressing the brake pedal according to the braking needs. The oil outlet of the power brake valve group 7 is connected to the first oil inlet (P1 port) of the brake valve 5, and the oil outlet (A5 port) of the brake valve 5 is connected to the brake port of the brake 6, so that the oil in the accumulator 4 can flow into the control port of the brake 6, thereby realizing the driving braking function in the manned driving mode. In the event of engine failure or pump failure, manual emergency braking can be performed, improving braking safety.

[0022] The power brake valve assembly 7 is mechanically connected to the pedal, and the power brake valve assembly 7 is provided with an oil return port (T port) that connects to the oil tank 1.

[0023] Example 2 like Figure 3Based on Example 1, the oil outlet of the filling valve 3 is also connected to the second oil inlet (P2 port) of the brake valve 5, and the accumulator 4 is also connected to the second oil inlet (P2 port) of the brake valve 5. The brake valve 5 can be switched to have its first oil inlet (P1 port) and its oil outlet (A5 port) internally connected, or its second oil inlet (P2 port) and its oil outlet (A5 port) internally connected.

[0024] The beneficial effect of adopting the preferred solution in the above embodiments is that when the driver is in autonomous driving mode, the power brake valve group 7 remains disconnected from the brake valve 5. At this time, the second oil inlet (P2 port) and the oil outlet (A5 port) of the brake valve 5 are internally connected. The oil in the accumulator 4 can flow into the control port of the brake 6 through the second oil inlet (P2 port) and the oil outlet (A5 port) of the brake valve 5, thereby realizing electronic emergency braking under autonomous driving mode and improving braking safety.

[0025] In this embodiment, the brake valve 5 is a proportional pressure reducing valve, which has a first working position and a third working position; for example Figure 2 When in the first working position, the second oil inlet (P2 port) and oil outlet (A5 port) of brake valve 5 are disconnected; if Figure 3 When the brake valve 5 is in the third working position, the second oil inlet (P2 port) and the oil outlet (A5 port) of the brake valve 5 are internally connected. At this time, when the pedal is not pressed, that is, when the driver is unmanned, the second oil inlet (P2 port) and the oil outlet (A5 port) of the brake valve 5 are internally connected. The oil in the accumulator 4 can flow into the control port of the brake 6 through the second oil inlet (P2 port) and the oil outlet (A5 port) of the brake valve 5, so as to realize electronic emergency braking under unmanned driving and improve braking safety.

[0026] Example 3 like Figures 1-4 Based on embodiments 1 and 2, the braking mechanism is provided with two sets, and the two brakes 6 are respectively connected to the left and right rear axles of the tractor. The first oil outlet (A1 port) of the filling valve 3 is connected to one of the accumulators 4, and the second oil outlet (A2 port) of the filling valve 3 is connected to the other accumulator 4.

[0027] The beneficial effect of adopting the preferred solution in the above embodiments is that the left and right rear axles of the tractor are braked by two sets of braking mechanisms respectively, so as to achieve the single-sided braking function.

[0028] Example 4 like Figure 2Based on embodiments 1-3, the power brake valve assembly 7 includes two power brake valves 71. The first oil outlet (A1 port) of the filling valve 3 is connected to the oil inlet (P4 port) of one of the power brake valves 71, and the second oil outlet (A2 port) of the filling valve 3 is connected to the oil inlet (P4 port) of the other power brake valve 71. The oil outlets (A4 ports) of the two power brake valves 71 are respectively connected to the first oil inlet (P1 port) of the two brake valves 5, and both power brake valves 71 can be switched to connect their oil inlet (P4 port) and their oil outlet (A4 port).

[0029] The beneficial effect of adopting the preferred solution in the above embodiments is that, during driving, when engine failure or pump failure occurs, the driver controls the valve core of the power brake valve group 7 to move by pressing the brake pedal according to the braking needs, so that the oil inlet (P4 port) of the power brake valve 71 can be connected to the corresponding oil outlet (A4 port). At the same time, the oil outlet (A4 port) of the power brake valve 71 is connected to the first oil inlet (P1 port) of the brake valve 5, and the oil outlet (A5 port) of the brake valve 5 is connected to the brake port of the brake 6, so that the oil in the accumulator 4 flows into the control port of the brake 6, thereby realizing the driving braking function in the manned driving mode.

[0030] like Figure 3 When the vehicle is unmanned and the pedal is not pressed, the oil inlet (P4 port) and the corresponding oil outlet (A4 port) of the two power brake valves 71 are disconnected. At this time, the second oil inlet (P2 port) and the oil outlet (A5 port) of the brake valve 5 are internally connected. The oil in the accumulator 4 can flow into the control port of the brake 6 through the second oil inlet (P2 port) and the oil outlet (A5 port) of the brake valve 5, thereby realizing electronic emergency braking under unmanned driving and improving braking safety.

[0031] Example 5 like Figure 3 and Figure 5 Based on embodiments 1-4, the power brake valve assembly 7 further includes two pipelines 72 corresponding to the two power brake valves 71 respectively. Both power brake valves 71 can be switched to disconnect their oil inlet (P4 port) from the oil inlet of the corresponding pipeline 72 and disconnect their oil outlet (A4 port) from the oil outlet of the corresponding pipeline 72. Alternatively, both power brake valves 71 can be switched to connect their oil inlet (P4 port) to the oil inlet of the corresponding pipeline 72 and connect their oil outlet (A4 port) to the oil outlet of the corresponding pipeline 72. Both pipelines 72 are equipped with a one-way valve 73.

[0032] The beneficial effect of adopting the preferred solution in the above embodiments is that, when manual braking occurs, the valve cores of the two power brake valves 71 move, and under the connection of the pipeline 72, the oil inlet (P4 port) of the power brake valve 71 can be connected with the corresponding oil outlet (A4 port), and under the action of the one-way valve 73, the one-way delivery of oil is realized.

[0033] Among them, the one-way valve 73 can be a spring-loaded one-way valve.

[0034] Example 6 like Figure 5 Based on embodiments 1-5, two pipelines 72 are simultaneously connected to a first pipeline section 74 and a second pipeline section 75. Both ends of the first pipeline section 74 are simultaneously connected to the oil inlet of the corresponding pipeline 72 and the oil inlet of the one-way valve 73. Both ends of the second pipeline section 75 are simultaneously connected to the oil outlet of the corresponding pipeline 72 and the oil outlet of the one-way valve 73. A third pipeline section 76 is simultaneously connected to the middle of the first pipeline section 74 and the oil inlet end of the third pipeline section 76. A shuttle valve 77 is configured at the middle end of the first pipeline section 74 and the oil inlet end of the third pipeline section 76. The shuttle valve 77 can be switched under oil pressure to connect the oil inlet of the third pipeline section 76 to one of the pipelines 72.

[0035] The beneficial effect of the preferred scheme in the above embodiments is that, during manual braking, when the oil passes through two power brake valves 71 and two sets of braking mechanisms to brake the left and right rear axles of the tractor respectively, during the process of the oil entering the power brake valve 71 being output to the oil outlet (A4 port) of the power brake valve 71 through the pipeline 72, when the oil pressure of one path is higher than that of the other path, the pressure pushes the shuttle valve 77 to adjust. The oil inlet of the third pipe section 76 is directly connected to the oil inlet (P4 port) of the power brake valve 71 of the path with higher oil pressure and the oil inlet of the one-way valve 73. The oil of the path with higher oil pressure can be directly diverted to the two pipelines 72 through the third pipe section 76 and the second pipe section 75, and output through the oil outlet (A4 port) of the two power brake valves 71 until the pressure of the two paths reaches balance. The third pipe section 76 is closed by the steel ball of the shuttle valve 77. In this way, the balance of braking pressure on both sides can be guaranteed.

[0036] Example 7 like Figure 5 Based on Examples 1-6, the second pipe section 75 is equipped with two throttle valves 78, and the oil inlets of the two throttle valves 78 are connected to the oil outlet of the third pipe section 76.

[0037] The beneficial effect of adopting the preferred scheme in the above embodiments is that the oil flow rate and velocity of the corresponding pipe section can be controlled by two throttle valves 78 to achieve regulation, thereby achieving the regulation of braking pressure.

[0038] Example 8 like Figure 5Based on embodiments 1-7, both power brake valves 71 have a first working position and a second working position. The valve cores of both power brake valves 71 can be moved to the first working position so that their oil inlet (P4 port) can be disconnected from the corresponding oil outlet (A4 port), or the valve cores of both power brake valves 71 can be moved to the second working position so that their oil inlet (P4 port) can be connected to the corresponding oil outlet (A4 port).

[0039] The beneficial effect of adopting the preferred solution in the above embodiments is that, during driving, when engine failure or pump failure occurs, the driver, according to braking needs, depresses the brake pedal, causing the valve core of the power brake valve 71 to move to the second working position, and enabling the oil inlet (P4 port) of the power brake valve 71 to connect with the corresponding oil outlet (A4 port). Simultaneously, the oil outlet (A4 port) of the power brake valve 71 connects to the first oil inlet (P1 port) of the brake valve 5, and the oil outlet (A5 port) of the brake valve 5 connects to the brake port of the brake 6, so as to automatically force the oil in the accumulator 4. The brake valve assembly 7 and brake valve 5 flow into the control port of the brake 6 to realize the service braking function in the manned driving mode; when the driver is driving, the valve core of the power brake valve 71 is in the first working position, and its oil inlet (P4 port) can be disconnected from the corresponding oil outlet (A4 port). At this time, the second oil inlet (P2 port) and oil outlet (A5 port) of the brake valve 5 are internally connected, and the oil in the accumulator 4 can flow into the control port of the brake 6 through the second oil inlet (P2 port) and oil outlet (A5 port) of the brake valve 5 to realize electronic emergency braking under driverless driving and improve braking safety.

[0040] Example 9 like Figure 4 Based on embodiments 1-8, the filling valve 3 has an oil return port T that connects to the oil tank 1 and a second load sensitive port (LS2) that connects to the first load sensitive port (LS1) of the load sensitive pump 2. The filling valve 3 can be switched to connect its oil return port (T) and its second load sensitive port (LS2).

[0041] The beneficial effect of adopting the preferred solution in the above embodiments is that when there is no braking requirement and the starting fluid filling reaches the fluid filling pressure set by the fluid filling valve 3, that is, when the high pressure of the oil outlet (A3 port) of the load-sensitive pump 2 is greater than the spring pressure value set by the valve core of the fluid filling valve 3, the fluid filling valve 3 reverses. At this time, the second load-sensitive port (LS2 port) of the fluid filling valve 3 is internally connected to the return port (T port) and simultaneously connected to the first load-sensitive port (LS1 port) of the load-sensitive pump 2. According to the control principle of the load-sensitive system, the load-sensitive pump 2 will stop outputting oil in this state, and the pressure of the accumulator 4 will be maintained. The pressure of the accumulator 4 will act on the fluid filling valve 3 at the same time. When the vehicle brakes, the pressure of the accumulator 4 will drop until the pressure drops to less than the spring setting value of the fluid filling valve 3, at which point the fluid filling valve 3 will reverse again and resume fluid filling.

[0042] In this embodiment of the invention, the filling valve 3 includes a one-way valve, a first control valve, and a second control valve. The one-way valve ensures unidirectional flow of the oil output from the outlet (A3 port) of the self-load sensitive pump 2. The first control valve controls whether filling occurs; when its valve core is in the right position, P3 port is connected to LS2 port, and filling occurs. The pressure increases with the filling flow rate. When the pressure rises above the spring pressure value on the right side of the first control valve, the valve core moves to the left, disconnecting P3 port from LS2 port. Simultaneously, LS2 port connects to T port, and filling stops. The outlet of the second control valve 3 is connected to the accumulator 4 through ports A1 and A2. If the filling pressure at port A1 is higher than that at port A2, the pressure acting on the left side of the second control valve will be higher than that on the right side, causing the valve core of the second control valve to move to the right. This increases the filling flow rate to port A2, thus ensuring the balance of filling pressure and flow rate at ports A1 and A2.

[0043] Example 10 This embodiment provides a tractor, including the tractor electronic control braking system with fluid filling function according to any one of embodiments 1-9.

[0044] By employing the above-mentioned tractor electronic braking system with fluid filling function, the specific working principle of the tractor of this utility model is as follows: In the initial state, such as Figure 1 Before starting the vehicle, the accumulator 4 is not filled with fluid. After the vehicle starts, the oil outlet A port of the load-sensitive pump 2 is connected to the oil inlet P port of the filling valve 3. At the same time, the oil outlet of the filling valve 3 is connected to the LS port of the filling valve 3 and fed back to the LS signal port of the load-sensitive pump 2. According to the control principle of the load-sensitive system, the pump will output oil in this state and fill the two accumulators 4 with oil through the A1 and A2 ports of the filling valve 3 respectively.

[0045] Working status one, such as Figure 2When the vehicle is driven by a driver, the driver controls the movement of the valve cores of the two power brake valves 71 by pressing the brake pedal according to the braking needs (the brake pedal and the power brake valves 71 are mechanically connected). At this time, the oil inlet P port and the corresponding oil outlet A port of the two power brake valves 71 are internally connected, and the oil outlet A port of the two power brake valves 71 are respectively connected to the control port of the corresponding brake 6 through the internal shuttle valve of the two brake valves 5. In this state, the oil in the two accumulators 4 can flow into the control port of the corresponding brake 6 to realize the driving braking function in the manned driving mode.

[0046] Working status two, such as Figure 3 When the vehicle is unmanned, the second oil inlet P2 of the brake valve 5 is connected to the internal shuttle valve and the oil outlet A, and is connected to the control port of the brake 6. The oil in the accumulator 4 can flow into the control port of the brake 6 through the second oil inlet P2 and the oil outlet A of the brake valve 5, realizing electronic emergency braking under unmanned driving and improving braking safety.

[0047] Working status three, such as Figure 4 When there is no braking requirement and the fluid filling reaches the set filling pressure of the filling valve 3, that is, when the high pressure of the oil outlet A port of the load-sensitive pump 2 is greater than the spring pressure value set by the valve core of the filling valve 3, the filling valve 3 reverses. At this time, the LS port of the filling valve 3 is internally connected to the oil return port T port, and is also connected to the LS port of the load-sensitive pump 2. According to the control principle of the load-sensitive system, the load-sensitive pump 2 will stop outputting oil in this state, and will maintain the pressure of the accumulator 4. The pressure of the accumulator 4 will act on the filling valve 3 at the same time. When the vehicle brakes, the pressure of the accumulator 4 will drop until the pressure drops below the spring set value of the filling valve 3, at which point the filling valve 3 will reverse again and resume filling.

[0048] In the description of this utility model, it should be understood that the terms "center", "longitudinal", "transverse", "length", "width", "thickness", "upper", "lower", "front", "rear", "left", "right", "vertical", "horizontal", "top", "bottom", "inner", "outer", "clockwise", "counterclockwise", "axial", "radial", "circumferential", etc., indicating the orientation or positional relationship are based on the orientation or positional relationship shown in the accompanying drawings, and are only for the convenience of describing this utility model and simplifying the description, and are not intended to indicate or imply that the device or element referred to must have a specific orientation, or be constructed and operated in a specific orientation, and therefore should not be construed as a limitation of this utility model.

[0049] Furthermore, the terms "first" and "second" are used for descriptive purposes only and should not be construed as indicating or implying relative importance or implicitly specifying the number of indicated technical features. Thus, a feature defined as "first" or "second" may explicitly or implicitly include at least one of that feature. In the description of this utility model, "a plurality of" means at least two, such as two, three, etc., unless otherwise explicitly specified.

[0050] In this utility model, unless otherwise explicitly specified and limited, the terms "installation," "connection," "joining," and "fixing," etc., should be interpreted broadly. For example, they can refer to a fixed connection, a detachable connection, or an integral part; they can refer to a mechanical connection or an electrical connection; they can refer to a direct connection or an indirect connection through an intermediate medium; they can refer to the internal communication of two components or the interaction between two components, unless otherwise explicitly limited. Those skilled in the art can understand the specific meaning of the above terms in this utility model according to the specific circumstances.

[0051] In this utility model, unless otherwise explicitly specified and limited, "above" or "below" the second feature can mean that the first feature is in direct contact with the second feature, or that the first feature is in indirect contact with the second feature through an intermediate medium. Furthermore, "above," "on top of," and "over" the second feature can mean that the first feature is directly above or diagonally above the second feature, or simply that the first feature is at a higher horizontal level than the second feature. "Below," "below," and "under" the second feature can mean that the first feature is directly below or diagonally below the second feature, or simply that the first feature is at a lower horizontal level than the second feature.

[0052] In the description of this specification, the references to terms such as "one embodiment," "some embodiments," "example," "specific example," or "some examples," etc., indicate that a specific feature, structure, material, or characteristic described in connection with that embodiment or example is included in at least one embodiment or example of the present invention. In this specification, the illustrative expressions of the above terms do not necessarily refer to the same embodiment or example. Furthermore, the specific features, structures, materials, or characteristics described may be combined in any suitable manner in one or more embodiments or examples. Moreover, without contradiction, those skilled in the art can combine and integrate the different embodiments or examples described in this specification, as well as the features of different embodiments or examples.

[0053] Although embodiments of the present invention have been shown and described above, it is understood that the above embodiments are exemplary and should not be construed as limiting the present invention. Those skilled in the art can make changes, modifications, substitutions and variations to the above embodiments within the scope of the present invention.

Claims

1. A tractor electronic braking system with fluid filling function, characterized in that, The system includes an oil tank (1), a load-sensitive pump (2), a filling valve (3), a braking mechanism, and a power brake valve assembly (7) for connection with the brake pedal. The oil inlet of the load-sensitive pump (2) is connected to the oil tank (1), and its outlet is connected to the inlet of the filling valve (3). The braking mechanism includes an accumulator (4), a brake valve (5), and a brake (6). The outlet of the filling valve (3) is connected to the inlet of the accumulator (4) and the power brake valve assembly (7). The accumulator (4) is also connected to the inlet of the power brake valve assembly (7). The outlet of the brake valve (5) is connected to the brake port of the brake (6). The outlet of the power brake valve assembly (7) is connected to the first inlet of the brake valve (5).

2. The tractor electronic braking system with fluid filling function according to claim 1, characterized in that, The outlet of the filling valve (3) is also connected to the second inlet of the brake valve (5), and the accumulator (4) is also connected to the second inlet of the brake valve (5). The brake valve (5) can be switched to have its first inlet connected to its outlet, or its second inlet connected to its outlet.

3. The tractor electronic braking system with fluid filling function according to claim 2, characterized in that, The braking mechanism is provided in two sets, and the two brakes (6) are respectively connected to the left and right rear axles of the tractor. The first oil outlet of the filling valve (3) is connected to one of the accumulators (4), and the second oil outlet of the filling valve (3) is connected to the other accumulator (4).

4. The tractor electronic braking system with fluid filling function according to claim 3, characterized in that, The power brake valve assembly (7) includes two power brake valves (71). The first oil outlet of the filling valve (3) is connected to the oil inlet of one of the power brake valves (71), and the second oil outlet of the filling valve (3) is connected to the oil inlet of the other power brake valve (71). The oil outlets of the two power brake valves (71) are respectively connected to the first oil inlets of the two brake valves (5), and both power brake valves (71) can be switched to connect their oil inlets and their oil outlets.

5. The tractor electronic braking system with fluid filling function according to claim 4, characterized in that, The power brake valve assembly (7) also includes two pipelines (72) corresponding to the two power brake valves (71) respectively. Both power brake valves (71) can be switched to disconnect their oil inlet from the oil inlet of the corresponding pipeline (72) and disconnect their oil outlet from the oil outlet of the corresponding pipeline (72). Alternatively, both power brake valves (71) can be switched to connect their oil inlet to the oil inlet of the corresponding pipeline (72) and connect their oil outlet to the oil outlet of the corresponding pipeline (72). Both pipelines (72) are equipped with check valves (73).

6. The tractor electronic braking system with fluid filling function according to claim 5, characterized in that, The two pipes (72) are simultaneously connected to a first pipe section (74) and a second pipe section (75). Both ends of the first pipe section (74) are simultaneously connected to the oil inlet of the corresponding pipe (72) and the oil inlet of the one-way valve (73). Both ends of the second pipe section (75) are simultaneously connected to the oil outlet of the corresponding pipe (72) and the oil outlet of the one-way valve (73). The middle of the first pipe section (74) and the second pipe section (75) are simultaneously connected to a third pipe section (76). A shuttle valve (77) is provided at the middle end of the first pipe section (74) and the oil inlet end of the third pipe section (76). The shuttle valve (77) can be switched under oil pressure to connect the oil inlet of the third pipe section (76) to one of the pipes (72).

7. The tractor electronic braking system with fluid filling function according to claim 6, characterized in that, The second pipe section (75) is equipped with two throttle valves (78), and the oil inlets of the two throttle valves (78) are connected to the oil outlet of the third pipe section (76).

8. The tractor electronic braking system with fluid filling function according to claim 4, characterized in that, Both of the power brake valves (71) have a first working position and a second working position. The valve cores of both power brake valves (71) can be moved to the first working position so that their oil inlet can be disconnected from the corresponding oil outlet, or moved to the second working position so that their oil inlet can be connected to the corresponding oil outlet.

9. A tractor electronic braking system with fluid filling function according to any one of claims 1-8, characterized in that, The filling valve (3) has an oil return port that connects to the oil tank (1) and a second load sensitive port that connects to the first load sensitive port of the load sensitive pump (2). The filling valve (3) can be switched to have its oil return port and its second load sensitive port connected internally.

10. A tractor, characterized in that, Including the tractor electronic braking system with fluid filling function as described in any one of claims 1-9.

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