Vehicle and hydraulic retarder system and control method thereof

Abstract

The invention discloses a vehicle and a hydraulic retarder system and a control method thereof, and relates to the technical field of vehicles. The hydraulic retarder system comprises a retarder, a transmission and a heat exchanger; an output gear of the transmission is meshed with an input gear of the retarder; an oil inlet and an oil outlet of the oil cavity in the retarder are respectively communicated with the oil outlet pipe and the oil inlet pipe; an oil pump is arranged in the oil inlet pipe; a throttle valve is arranged in the oil outlet pipe; a liquid inlet and a liquid outlet of the heat exchanger are respectively communicated with a liquid outlet pipe and a liquid inlet pipe; the control method comprises the steps that when an output gear of the transmission drives an input gear of the retarder to start rotation, the current target oil pressure of an oil cavity in the retarder is obtained; and according to the oil temperature in the oil outlet pipe, the liquid temperature in the liquid outlet pipe and the current actual oil pressure of the oil cavity in the retarder, the opening degree of the throttling valve and the operation parameters of the oil pump are adjusted till the current actual oil pressure of the oil cavity in the retarder is at the current target oil pressure. The stability of oil temperature and oil pressure in the retarder is ensured, and the braking capacity of the retarder is improved.

Description

Technical Field

[0001] Embodiments of the present invention relate to the technical field of vehicles, and in particular, to a vehicle, a hydraulic retarder system thereof, and a control method therefor. Background Art

[0002] As an important auxiliary braking device, hydraulic retarders are increasingly widely used in the domestic commercial vehicle field, which can effectively improve the braking safety and driving comfort of vehicles under complex working conditions. With the diversification of the driving conditions of commercial vehicles, drivers' requirements for the performance of braking systems are constantly increasing.

[0003] In the prior art, a hydraulic retarder mainly converts the mechanical energy of a vehicle into the heat energy of oil through energy conversion, and exchanges the heat energy of the oil with the outside through the vehicle radiator, so as to effectively reduce the burden on the main braking system of the vehicle.

[0004] However, in the prior art, the oil inlet flow rate and oil discharge flow rate of the hydraulic retarder are usually fixedly set and cannot be dynamically adjusted according to the actual heat dissipation requirements, which may cause the radiator to be unable to effectively dissipate the heat of the oil in the hydraulic retarder. Under continuous braking conditions such as long downhill slopes, the hydraulic retarder will generate a large amount of heat during long-term operation. If the heat dissipation is not timely, the oil temperature in the hydraulic retarder will rise rapidly. When the oil temperature reaches the over-temperature threshold, the hydraulic retarder enters a torque-limiting state, resulting in a significant decrease in braking force, thereby affecting the braking ability of the vehicle. Summary of the Invention

[0005] The present invention provides a vehicle, a hydraulic retarder system thereof, and a control method therefor, which ensure the stability of the oil temperature and oil pressure in the hydraulic retarder by dynamically adjusting the oil inlet flow rate and oil discharge flow rate of the hydraulic retarder, thereby improving the braking ability of the hydraulic retarder system.

[0006] The first aspect of the present invention provides a control method for a vehicle hydraulic retarder system. The hydraulic retarder system includes a retarder, a transmission, and a heat exchanger; the input shaft of the transmission is connected to the output shaft of the vehicle engine, and the output gear of the transmission meshes with the input gear of the retarder; the oil inlet of the oil chamber in the retarder is communicated with an oil inlet pipe, and the oil outlet of the oil chamber in the retarder is communicated with an oil outlet pipe; a oil pump is arranged in the oil inlet pipe; a throttle valve is arranged in the oil outlet pipe; the heat exchanger is arranged in the path of the oil outlet pipe; the liquid inlet of the heat exchanger is communicated with a liquid inlet pipe, and the liquid outlet of the heat exchanger is communicated with a liquid outlet pipe; the control method for the vehicle hydraulic retarder system includes:

[0007] When the output gear of the transmission drives the input gear of the retarder to start rotating, obtain the current target oil pressure in the oil chamber of the retarder;

[0008] Obtain the oil temperature in the oil outlet pipe, the liquid temperature in the liquid outlet pipe, and the actual oil pressure in the oil chamber of the retarder in real time;

[0009] Adjust the opening degree of the throttle valve and the operating parameters of the oil pump according to the oil temperature in the oil outlet pipe, the liquid temperature in the liquid outlet pipe, and the current actual oil pressure in the oil chamber of the retarder until the current actual oil pressure in the oil chamber of the retarder is within the current target oil pressure.

[0010] Optionally, when the output gear of the transmission drives the input gear of the retarder to start rotating, obtaining the current target oil pressure in the oil chamber of the retarder includes:

[0011] When the output gear of the transmission drives the input gear of the retarder to start rotating, obtain the current rotational speed of the input gear of the retarder and the current braking torque percentage signal of the vehicle;

[0012] Obtain the mapping relationship between the rotational speed of the input gear of the retarder, the braking torque percentage signal of the vehicle, and the target oil pressure in the oil chamber of the retarder;

[0013] Determine the target oil pressure corresponding to the current rotational speed and the current braking torque percentage signal as the current target oil pressure in the oil chamber of the retarder according to the mapping relationship.

[0014] Optionally, before obtaining the oil temperature in the oil outlet pipe, the liquid temperature in the liquid outlet pipe, and the actual oil pressure in the oil chamber of the retarder in real time, it further includes:

[0015] Adjust the initial opening degree of the throttle valve to a first opening degree;

[0016] Adjust the operating parameters of the oil pump according to a preset parameter adjustment rule to increase the oil supply flow rate of the oil pump, and perform the step of obtaining the actual oil pressure in the oil chamber of the retarder in real time;

[0017] When the current actual oil pressure in the oil chamber of the retarder reaches the current target oil pressure, control the oil pump to work with the current operating parameters, and adjust the current opening degree of the throttle valve to a second opening degree; wherein, the first opening degree is smaller than the second opening degree.

[0018] Optionally, adjusting the opening degree of the throttle valve and the operating parameters of the oil pump according to the oil temperature in the oil outlet pipe, the liquid temperature in the liquid outlet pipe, and the current actual oil pressure in the oil chamber of the retarder until the current actual oil pressure in the oil chamber of the retarder is within the current target oil pressure includes:

[0019] Determine the current change rate of the oil temperature according to the oil temperature in the oil outlet pipe, and determine the current change rate of the liquid temperature according to the liquid temperature in the liquid outlet pipe;

[0020] Determine a current rate ratio between the current change rate of the oil temperature and the current change rate of the liquid temperature according to the current change rate of the oil temperature and the current change rate of the liquid temperature;

[0021] Adjust the opening degree of the throttle valve and the operating parameters of the oil pump according to the current oil temperature in the oil outlet pipe, the current liquid temperature in the liquid outlet pipe, the current rate ratio, and the current actual oil pressure in the oil chamber of the retarder until the current actual oil pressure in the oil chamber of the retarder is at the current target oil pressure.

[0022] Optionally, adjusting the opening degree of the throttle valve and the operating parameters of the oil pump according to the current oil temperature in the oil outlet pipe, the current liquid temperature in the liquid outlet pipe, the current rate ratio, and the current actual oil pressure in the oil chamber of the retarder until the current actual oil pressure in the oil chamber of the retarder is at the current target oil pressure includes:

[0023] When the current oil temperature in the oil outlet pipe is greater than or equal to a preset oil temperature threshold, the current liquid temperature in the liquid outlet pipe is greater than or equal to a preset liquid temperature threshold, and the current rate ratio is greater than a preset rate ratio threshold, determine a target opening degree of the opening degree of the throttle valve;

[0024] Adjust the current opening degree of the throttle valve to the target opening degree;

[0025] Adjust the operating parameters of the oil pump according to a preset parameter adjustment rule to increase the oil supply flow rate of the oil pump, and return to execute the step of obtaining the actual oil pressure in the oil chamber of the retarder in real time;

[0026] When the current actual oil pressure in the oil chamber of the retarder reaches the current target oil pressure, control the oil pump to work with the current operating parameters.

[0027] Optionally, after controlling the oil pump to work with the current operating parameters when the current actual oil pressure in the oil chamber of the retarder reaches the current target oil pressure, it further includes:

[0028] When the current oil temperature in the oil outlet pipe is less than the preset oil temperature threshold, or the current liquid temperature in the liquid outlet pipe is less than the preset liquid temperature threshold, or the current rate ratio is less than or equal to the preset rate ratio threshold, adjust the current opening degree of the throttle valve to a second opening degree;

[0029] Adjust the operating parameters of the oil pump according to a preset parameter adjustment rule to reduce the oil supply flow rate of the oil pump, and return to execute the step of obtaining the actual oil pressure in the oil chamber of the retarder in real time;

[0030] When the current actual oil pressure in the oil chamber of the retarder reaches the current target oil pressure, control the oil pump to operate with the current operating parameters.

[0031] Optionally, after adjusting the opening degree of the throttle valve and the operating parameters of the oil pump according to the oil temperature in the outlet pipe, the liquid temperature in the liquid outlet pipe, and the current actual oil pressure in the oil chamber of the retarder until the current actual oil pressure in the oil chamber of the retarder is within the current target oil pressure, it further includes:

[0032] When the input gear of the retarder stops rotating, adjust the current opening degree of the throttle valve to the maximum opening degree;

[0033] Adjust the operating parameters of the oil pump according to a preset parameter adjustment rule to reduce the oil supply flow rate of the oil pump until the oil supply flow rate of the oil pump is adjusted to 0.

[0034] A second aspect of the present invention provides a vehicle hydraulic retarder system, and the vehicle hydraulic retarder system includes: a retarder, a transmission, a heat exchanger, and a controller;

[0035] The input shaft of the transmission is connected to the output shaft of the vehicle engine, and the output gear of the transmission meshes with the input gear of the retarder;

[0036] The oil inlet of the oil chamber in the retarder is communicated with an inlet pipe, and the oil outlet of the oil chamber in the retarder is communicated with an outlet pipe; an oil pump is arranged in the inlet pipe; a throttle valve is arranged in the outlet pipe;

[0037] The heat exchanger is arranged in the path of the outlet pipe; the liquid inlet of the heat exchanger is communicated with a liquid inlet pipe, and the liquid outlet of the heat exchanger is communicated with a liquid outlet pipe;

[0038] The controller is respectively connected to the input gear of the retarder, the oil pump, and the throttle valve, and the controller is used to execute the control method of the vehicle hydraulic retarder system as described above.

[0039] Optionally, the vehicle hydraulic retarder system further includes: an oil sump, an oil pressure sensor, an oil temperature sensor, and a liquid temperature sensor;

[0040] One end of the inlet pipe and one end of the outlet pipe are both located in the oil sump; the oil sump is used to store oil;

[0041] The oil pressure sensor is arranged in the retarder, and the oil pressure sensor is used to obtain the oil pressure in the oil chamber of the retarder;

[0042] The oil temperature sensor is arranged in the outlet pipe, and the oil temperature sensor is used to obtain the oil temperature in the outlet pipe;

[0043] The liquid temperature sensor is arranged in the liquid outlet pipe, and the liquid temperature sensor is used to obtain the liquid temperature in the liquid outlet pipe;

[0044] The controller is also respectively connected to the oil pressure sensor, the oil temperature sensor and the liquid temperature sensor. The controller is further configured to obtain the oil pressure in the oil cavity of the retarder based on the oil pressure sensor, obtain the oil temperature in the liquid outlet pipe based on the oil temperature sensor, and obtain the liquid temperature in the liquid outlet pipe based on the liquid temperature sensor.

[0045] A third aspect of the present invention provides a vehicle, which includes: a vehicle frame, an engine arranged in the vehicle frame, and the vehicle hydraulic retarder system as described above.

[0046] According to the technical solution of the present invention, when the output gear of the transmission drives the input gear of the retarder to start rotating, the current target oil pressure in the oil cavity of the retarder is obtained, so that when it is necessary to generate a braking torque through the retarder, the current target oil pressure in the oil cavity of the retarder can be obtained, providing a basis for dynamically adjusting the opening of the throttle valve and the operating parameters of the oil pump subsequently. By obtaining the oil temperature in the liquid outlet pipe, the liquid temperature in the liquid outlet pipe and the actual oil pressure in the oil cavity of the retarder in real time, it is possible to judge in real time whether the oil temperature in the liquid outlet pipe exceeds the oil temperature threshold, whether the liquid temperature in the liquid outlet pipe exceeds the liquid temperature threshold, and whether the current actual oil pressure in the oil cavity of the retarder is maintained at the current target oil pressure. At the same time, by adjusting the opening of the throttle valve and the operating parameters of the oil pump according to the oil temperature in the liquid outlet pipe, the liquid temperature in the liquid outlet pipe and the current actual oil pressure in the oil cavity of the retarder until the current actual oil pressure in the oil cavity of the retarder is at the current target oil pressure, when the oil temperature in the liquid outlet pipe exceeds the oil temperature threshold and the liquid temperature in the liquid outlet pipe exceeds the liquid temperature threshold, the opening of the throttle valve can be increased and the operating parameters of the oil pump can be adjusted to increase the amount of oil entering the oil cavity of the retarder through the oil pump, so as to enhance the heat dissipation effect of the heat exchanger and enable the current actual oil pressure in the oil cavity of the retarder to return to the current target oil pressure, thereby maintaining the stability of the oil temperature and oil pressure in the oil cavity of the retarder, ensuring that the retarder can continuously output a stable braking torque, improving the braking ability of the hydraulic retarder system, and at the same time improving the smoothness and safety of the driving experience.

[0047] It should be understood that the content described in this part is not intended to identify the key or important features of the embodiments of the present invention, nor is it used to limit the scope of the present invention. Other features of the present invention will become easily understood through the following description. Description of the Drawings

[0048] To more clearly illustrate the technical solutions in the embodiments of the present invention, the following will briefly introduce the drawings required for the description of the embodiments. Obviously, the drawings in the following description are only some embodiments of the present invention. For those of ordinary skill in the art, without creative efforts, other drawings can be obtained based on these drawings.

[0049] Figure 1 It is a schematic structural diagram of a vehicle hydraulic retarder system provided in Embodiment 1 of the present invention;

[0050] Figure 2 It is a schematic flowchart of a control method for a vehicle hydraulic retarder system provided in Embodiment 2 of the present invention;

[0051] Figure 3 It is a schematic flowchart of a control method for a vehicle hydraulic retarder system provided in Embodiment 3 of the present invention. Detailed Embodiments

[0052] In order to enable those skilled in the art to better understand the solutions of the present invention, the following will clearly and completely describe the technical solutions in the embodiments of the present invention in conjunction with the drawings in the embodiments of the present invention. Obviously, the described embodiments are only some of the embodiments of the present invention, rather than all of them. Based on the embodiments of the present invention, all other embodiments obtained by those of ordinary skill in the art without creative efforts shall fall within the protection scope of the present invention.

[0053] It should be noted that the terms "first", "second", etc. in the specification and claims of the present invention and the above drawings are used to distinguish similar objects, and do not necessarily need to describe a specific order or sequence. It should be understood that such data can be interchanged under appropriate circumstances so that the embodiments of the present invention described here can be implemented in an order other than those illustrated or described here. In addition, the terms "comprising" and "having" and any variations thereof are intended to cover non-exclusive inclusion. For example, a process, method, system, product or device that includes a series of steps or units does not necessarily have to be limited to those steps or units clearly listed, but may include other steps or units not clearly listed or inherent to these processes, methods, products or devices.

[0054] Embodiment 1

[0055] Figure 1 It is a schematic structural diagram of a vehicle hydraulic retarder system provided in Embodiment 1 of the present invention, as Figure 1As shown in the figure, the vehicle hydraulic retarder system includes: a retarder 1, a transmission 2, a heat exchanger 3, and a controller 4; the input shaft of the transmission 2 is connected to the output shaft of the vehicle engine, and the output gear 21 of the transmission 2 meshes with the input gear 11 of the retarder 1; the oil inlet 12 of the oil chamber in the retarder 1 is communicated with the oil inlet pipe 51, and the oil outlet 13 of the oil chamber in the retarder 1 is communicated with the oil outlet pipe 52; a oil pump 6 is arranged in the oil inlet pipe 51; a throttle valve 7 is arranged in the oil outlet pipe 52; the heat exchanger 3 is arranged in the path of the oil outlet pipe 52; the liquid inlet 31 of the heat exchanger 3 is communicated with the liquid inlet pipe 81, and the liquid outlet 32 of the heat exchanger 3 is communicated with the liquid outlet pipe 82.

[0056] Among them, the retarder 1 can be specifically understood as an auxiliary braking device installed in the vehicle transmission system. The retarder 1 is used to generate a braking torque to achieve vehicle deceleration, thereby reducing the burden on the main braking system, such as brake pads, reducing brake pad wear, and avoiding the braking efficiency heat fade caused by overheating of the main braking system, improving driving safety. Specifically, the retarder 1 internally includes a rotor and a stator. The rotor is a rotatable component, and the stator is a fixed component. The rotor and the stator jointly form the oil chamber of the retarder 1 at a fixed distance. At the same time, the oil inlet 12 of the oil chamber in the retarder 1 is communicated with the oil inlet pipe 51, and the oil outlet 13 of the oil chamber in the retarder 1 is communicated with the oil outlet pipe 52, so that the oil can enter the oil chamber of the retarder 1 through the oil inlet pipe 51, and the oil can flow out of the oil chamber of the retarder 1 through the oil outlet pipe 52. Exemplarily, the oil can include hydraulic oil, which has high viscosity, high temperature resistance, and good lubrication performance, and can maintain stability under high temperature and high pressure, thus ensuring the efficient operation of the retarder 1.

[0057] The input shaft of the transmission 2 is connected to the output shaft of the vehicle engine, so that after the transmission 2 obtains the speed and torque of the vehicle engine, it can adjust the speed and torque of the vehicle engine through the internal gear set, for example, adjust the high speed and low torque of the engine to low speed and high torque to match the different braking force requirements of the vehicle under working conditions such as climbing, accelerating, or driving at a constant speed. The output gear 21 of the transmission 2 meshes with the input gear 11 of the retarder 1, so that after the transmission 2 adjusts the speed and torque of the engine, it can transmit the adjusted power to the input gear 11 of the retarder 1 through its output gear 21. The input gear 11 of the retarder 1 is used to drive the rotor in the retarder 1 to rotate according to the power transmitted by the output gear 21 of the transmission 2, thereby providing mechanical energy input for the retarder 1.

[0058] Specifically, when braking is required during the driving of the vehicle, the power of the vehicle engine is transmitted through the transmission 2 to the output gear 21 of the transmission 2 and the input gear 11 of the retarder 1 in sequence. The input gear 11 of the retarder 1 drives the rotor in the retarder 1 to rotate. When the rotor rotates, it will drive the oil in the oil chamber of the retarder 1 to flow at high speed, so that the high-speed flowing oil impacts the stator that is fixed in the retarder 1, thereby generating shear force and eddy current effect, which hinders the rotation of the rotor, so as to generate braking torque through the hindering effect of the stator on the rotation of the rotor. This braking torque can be transmitted reversely through the rotor to the vehicle's transmission shaft 21 and finally to the wheels, reducing the wheel speed and thus achieving vehicle deceleration. It can be understood that the oil in the retarder 1 can convert the mechanical energy of the vehicle into heat energy due to the shear and eddy current effects during braking, causing the oil temperature to rise. The high-temperature oil can flow out through the outlet pipe 52 and then pass through the heat exchanger 3. The heat exchanger 3 can use the coolant flowing in through the inlet pipe 81 to exchange heat with the high-temperature oil. After absorbing the heat of the oil, the coolant temperature rises and can flow out through the outlet pipe 82. Exemplarily, the coolant can include an ethylene glycol aqueous solution. The high-temperature oil is then cooled, and the cooled oil flows back into the oil chamber of the retarder 1 through the inlet pipe 51, thus completing the oil circulation in the hydraulic retarder system.

[0059] In addition, an oil pump 6 is provided in the inlet pipe 51. Exemplarily, the oil pump 6 can include a variable flow pump. By adjusting the magnitude of the control current of the oil pump 6, the flow rate of the oil provided by the oil pump 6 to the oil chamber in the retarder 1 can be changed, so as to control the amount of oil entering the oil chamber in the retarder 1. A throttle valve 7 is provided in the outlet pipe 52. Exemplarily, the throttle valve 7 can include an electronically controlled throttle valve. The electronically controlled throttle valve can include multiple opening levels, such as a first opening level, a second opening level, and a third opening level with the opening increasing from small to large, so as to control the amount of oil flowing out of the oil chamber of the retarder 1 by adjusting the opening of the throttle valve 7. It can be understood that by dynamically adjusting the operating parameters of the oil pump 6 and the opening of the throttle valve 7, the heat dissipation effect of the heat exchanger 3 can also be dynamically adjusted. By increasing the oil discharge amount, more high-temperature oil can flow into the heat exchanger 3, thereby increasing the heat dissipation amount of the heat exchanger 3, ensuring the stability of the oil temperature, avoiding the over-temperature torque limit of the retarder 1 caused by too high oil temperature, and thus improving the braking ability of the retarder 1. At the same time, by dynamically adjusting the working states of the oil pump 6 and the throttle valve 7, the control of the oil inlet amount and the oil discharge amount in the oil chamber of the retarder 1 can be realized, so as to maintain the stability of the oil amount in the oil chamber, and thus maintain the stability of the oil pressure in the oil chamber, ensure the stability of the braking torque generated by the retarder 1, guarantee the vehicle deceleration effect, and improve the smoothness and safety of the driving experience.

[0060] Optionally, continue to refer to Figure 1, the vehicle hydraulic retarder system further includes: an oil sump 9, an oil pressure sensor 101, an oil temperature sensor 102, and a liquid temperature sensor 103; one end of the inlet pipe 51 and one end of the outlet pipe 52 are both located in the oil sump 9; the oil sump 9 is used to store oil; the oil pressure sensor 101 is arranged in the retarder 1, and the oil pressure sensor 101 is used to obtain the oil pressure in the oil chamber of the retarder 1; the oil temperature sensor 102 is arranged in the outlet pipe 52, and the oil temperature sensor 102 is used to obtain the oil temperature in the outlet pipe 52; the liquid temperature sensor 103 is arranged in the liquid outlet pipe 82, and the liquid temperature sensor 103 is used to obtain the liquid temperature in the liquid outlet pipe 82.

[0061] Among them, the oil sump 9 is used to store the oil provided to the retarder 1 by the oil pump 6. Specifically, the oil sump 9 can receive the oil cooled by the heat exchanger 3 through one end of the outlet pipe 52. At the same time, the oil sump 9 can provide a stable oil supply to the retarder 1 through one end of the inlet pipe 51 and the oil pump 6 to ensure the sufficiency of the oil volume in the oil chamber of the retarder 1, so as to maintain the stability of the braking torque generated by the retarder 1.

[0062] The oil pressure sensor 101 can include a piezoresistive or capacitive pressure sensor. The oil pressure sensor 101 can be arranged in the oil chamber of the retarder 1 to obtain the oil pressure in the oil chamber in real time. The oil temperature sensor 102 can include a thermistor or thermocouple temperature sensor. The oil temperature sensor 102 can be arranged at the oil outlet 13 of the outlet pipe 52 close to the oil chamber of the retarder 1 to obtain the temperature of the high-temperature oil flowing out of the oil chamber in real time. The liquid temperature sensor 103 can include a thermistor or thermocouple temperature sensor. The liquid temperature sensor 103 can be arranged at the liquid outlet 32 of the liquid outlet pipe 82 close to the heat exchanger 3 to obtain the coolant temperature flowing out of the heat exchanger 3 in real time.

[0063] In addition, the controller 4 is respectively connected to the input gear 11, the oil pump 6, the throttle valve 7, the oil pressure sensor 101, the oil temperature sensor 102, and the liquid temperature sensor 103 of the retarder 1, so that the controller 4 can obtain the oil pressure in the oil chamber of the retarder 1 based on the oil pressure sensor 101 in real time, obtain the oil temperature in the outlet pipe 52 based on the oil temperature sensor 102, and obtain the liquid temperature in the liquid outlet pipe 82 based on the liquid temperature sensor 103, and can dynamically adjust the operating parameters of the oil pump 6 and the opening of the throttle valve 7 according to the oil pressure in the oil chamber of the retarder 1, the oil temperature in the outlet pipe 52, and the liquid temperature in the liquid outlet pipe 82.

[0064] It can be understood that the controller 4 in the vehicle hydraulic retarder system can execute the control method of the vehicle hydraulic retarder system provided by the embodiments of the present invention, and has the corresponding functional modules and beneficial effects of the execution method. For the technical details not described in detail in this embodiment, reference can be made to the control method of the vehicle hydraulic retarder system described in the following embodiments.

[0065] Embodiment 2

[0066] Figure 2 FIG. is a schematic flow chart of a control method for a vehicle hydraulic retarder system provided in Embodiment 2 of the present invention. This embodiment can be used to control the vehicle hydraulic retarder system in the above embodiment. This method can be executed by a control device of the vehicle hydraulic retarder system. The device can be implemented in a software and / or hardware manner and is generally integrated in the controller of the vehicle hydraulic retarder system. Correspondingly, as Figure 2 shown, the control method of the vehicle intake bypass system may include:

[0067] S101. When the output gear of the transmission drives the input gear of the retarder to start rotating, obtain the current target oil pressure in the oil chamber of the retarder.

[0068] Specifically, the rotation of the output gear of the transmission driving the input gear of the retarder can be triggered by the driver operating the retarder control handle installed in the cockpit. Exemplarily, the retarder control handle can include a multi-gear lever-type handle, for example, it can include 5 gears, and the braking torque percentages corresponding to each gear are 0%, 25%, 50%, 75%, and 100% respectively. When the driver pushes the handle from the 0th gear to the 2nd gear, it indicates that braking torque needs to be generated by the retarder at this time. The transmission will obtain the engine speed and torque of the vehicle and make adjustments so that the transmission can transmit the adjusted power to the input gear of the retarder through its output gear, thereby driving the input gear of the retarder to start rotating. At the same time, the input gear of the retarder can drive the rotor in the retarder to rotate according to the power transmitted by the output gear of the transmission, thereby providing mechanical energy input for the retarder. When the controller detects that the output gear of the transmission drives the input gear of the retarder to start rotating, it will obtain the current target oil pressure in the oil chamber of the retarder, thereby providing a basis for dynamically adjusting the opening of the throttle valve and the operating parameters of the oil pump in the subsequent process, so that the current actual oil pressure in the oil chamber of the retarder can be maintained at the current target oil pressure, ensuring that the current oil pressure in the oil chamber of the retarder can remain stable during the process of generating braking torque through the retarder.

[0069] Optionally, when the output gear of the transmission drives the input gear of the retarder to start rotating, obtaining the current target oil pressure in the oil chamber of the retarder includes: when the output gear of the transmission drives the input gear of the retarder to start rotating, obtaining the current rotation speed of the input gear of the retarder and the current braking torque percentage signal of the vehicle; obtaining the mapping relationship between the rotation speed of the input gear of the retarder and the braking torque percentage signal of the vehicle and the target oil pressure in the oil chamber of the retarder; and determining the target oil pressure corresponding to the current rotation speed and the current braking torque percentage signal as the current target oil pressure in the oil chamber of the retarder according to the mapping relationship.

[0070] Specifically, when the output gear of the transmission drives the input gear of the retarder to start rotating, the controller can obtain the current speed of the input gear of the retarder through the speed sensor installed on the input gear of the retarder. At the same time, the controller can also obtain the current braking torque percentage signal of the vehicle through the retarder control handle manipulated by the driver. For example, when the retarder control handle is in the second gear, the corresponding current braking torque percentage of the vehicle is 25%. After obtaining the current speed of the input gear of the retarder and the current braking torque percentage signal of the vehicle, the controller can also determine the target oil pressure corresponding to the current speed and the current braking torque percentage signal as the current target oil pressure of the oil chamber in the retarder according to the mapping relationship between the speed of the input gear of the retarder, the current braking torque percentage signal of the vehicle and the target oil pressure of the oil chamber in the retarder.

[0071] Among them, the mapping relationship between the speed of the input gear of the retarder, the current braking torque percentage signal of the vehicle and the target oil pressure of the oil chamber in the retarder can be established based on experimental data, mathematical models or empirical laws, and is used to map the value of the current speed and the value of the current braking torque percentage signal to the corresponding value of the target oil pressure of the oil chamber in the retarder, and take the corresponding value of the target oil pressure as the current target oil pressure of the oil chamber in the retarder. Exemplarily, the mapping relationship can be implemented through a MAP diagram between the speed of the input gear of the retarder, the current braking torque percentage signal of the vehicle and the target oil pressure of the oil chamber in the retarder. By establishing a suitable mapping relationship, it is possible to dynamically adjust the target oil pressure of the oil chamber in the retarder according to the changes in the speed of the input gear of the retarder and the current braking torque percentage signal of the vehicle when the output gear of the transmission drives the input gear of the retarder to start rotating.

[0072] It can be understood that the braking torque of the retarder is mainly determined by the oil pressure in the oil chamber of the retarder, and the oil pressure in the oil chamber of the retarder is closely related to the rotational speed of the input gear of the retarder and the demand for the braking torque percentage of the vehicle. The input gear of the retarder is used to drive the rotor in the retarder to rotate. Therefore, the rotational speed of the input gear of the retarder reflects the rotational speed of the rotor. The rotational speed of the rotor determines the shear force and the intensity of the eddy current effect of the oil in the oil chamber of the retarder, thereby affecting the oil pressure demand in the oil chamber of the retarder. Exemplarily, when the vehicle speed is relatively high, the rotational speeds of both the input gear of the retarder and the rotor increase accordingly. The oil in the oil chamber of the retarder is driven more quickly, resulting in an enhanced impact force of the oil on the stator, thereby causing the dynamic pressure in the oil chamber to increase. Therefore, a greater oil pressure is required to match the higher rotor speed to generate a greater braking torque to meet the braking demand during high-speed driving. The braking torque percentage of the vehicle reflects the driver's braking demand, and the target braking torque corresponding to the braking demand needs to be achieved through a specific oil pressure in the oil chamber of the retarder. By comprehensively considering the current rotational speed of the input gear of the retarder and the demand for the current braking torque percentage of the vehicle when the output gear of the transmission drives the input gear of the retarder to start rotating, the current target oil pressure in the oil chamber of the retarder can be determined more precisely, so as to ensure that the braking torque generated by the retarder matches the driver's braking demand, guarantee the vehicle deceleration effect, and improve the smoothness and safety of the driving experience.

[0073] S102. Obtain the oil temperature in the oil outlet pipe, the liquid temperature in the liquid outlet pipe, and the actual oil pressure in the oil chamber of the retarder in real time.

[0074] Specifically, during the process of generating the braking torque by the retarder, the controller can obtain the oil temperature in the oil outlet pipe in real time based on the oil temperature sensor arranged in the oil outlet pipe, obtain the liquid temperature in the liquid outlet pipe based on the liquid temperature sensor arranged in the liquid outlet pipe, and obtain the actual oil pressure in the oil chamber of the retarder based on the oil pressure sensor arranged in the retarder. By obtaining the oil temperature in the oil outlet pipe in real time, the controller can determine whether the oil temperature in the oil outlet pipe exceeds the oil temperature threshold. By obtaining the liquid temperature in the liquid outlet pipe in real time, the controller can evaluate the heat dissipation efficiency of the heat exchanger. If the liquid temperature is too high, it indicates that the heat dissipation capacity of the heat exchanger is insufficient at this time. By obtaining the actual oil pressure in the oil chamber of the retarder in real time, the controller can compare the actual oil pressure in the oil chamber of the retarder with the current target oil pressure in the oil chamber of the retarder, thereby providing a data basis for the controller to dynamically adjust the opening degree of the throttle valve and the operating parameters of the oil pump.

[0075] S103. Adjust the opening degree of the throttle valve and the operating parameters of the oil pump according to the oil temperature in the oil outlet pipe, the liquid temperature in the liquid outlet pipe, and the current actual oil pressure in the oil chamber of the retarder until the current actual oil pressure in the oil chamber of the retarder is within the current target oil pressure.

[0076] Specifically, after the controller obtains the oil temperature in the oil outlet pipe, the liquid temperature in the liquid outlet pipe, and the actual oil pressure in the oil chamber of the retarder in real time, it can adjust the opening degree of the throttle valve and the operating parameters of the oil pump according to the oil temperature in the oil outlet pipe, the liquid temperature in the liquid outlet pipe, and the current actual oil pressure in the oil chamber of the retarder. Among them, the oil pump can include a variable flow pump. By adjusting the magnitude of the control current of the oil pump, the flow rate of the oil supplied by the oil pump to the oil chamber of the retarder can be changed, so that the amount of oil entering the oil chamber of the retarder can be controlled; the throttle valve can include an electronically controlled throttle valve, and the electronically controlled throttle valve can include multiple opening degrees, such as a first opening degree, a second opening degree, and a third opening degree with the opening degree increasing from small to large, so as to be able to control the amount of oil flowing out of the oil chamber of the retarder by adjusting the opening degree of the throttle valve. Exemplarily, when the oil temperature in the oil outlet pipe exceeds the oil temperature threshold and the liquid temperature in the liquid outlet pipe exceeds the liquid temperature threshold, the controller can increase the opening degree of the throttle valve to enable more high-temperature oil to flow into the heat exchanger, thereby enhancing the heat dissipation effect of the heat exchanger and being able to reduce the oil temperature in the oil chamber of the retarder. After increasing the oil discharge amount in the oil chamber of the retarder by increasing the opening degree of the throttle valve, it may cause the current actual oil pressure in the oil chamber of the retarder to decrease. Therefore, the controller can adjust the magnitude of the control current of the oil pump to increase the amount of oil entering the oil chamber of the retarder through the oil pump, and can obtain the current actual oil pressure in the oil chamber of the retarder in real time, so that the current actual oil pressure in the oil chamber of the retarder is restored to the current target oil pressure, thereby maintaining the stability of the oil pressure in the oil chamber of the retarder.

[0077] By dynamically adjusting the opening degree of the throttle valve and the operating parameters of the oil pump to maintain the stability of the oil temperature and oil pressure in the oil chamber of the retarder, it avoids the limitation of the braking torque output by the retarder due to too high oil temperature and the oil pressure fluctuation in the oil chamber of the retarder, ensures that the retarder can continuously output a stable braking torque, improves the braking ability of the hydraulic retarder system, and realizes the expected deceleration effect of the vehicle. At the same time, it avoids the speed jitter during the vehicle deceleration process caused by the sudden change of the braking performance of the hydraulic retarder system, and improves the smoothness and safety of the driving experience.

[0078] Optionally, before obtaining the oil temperature in the oil outlet pipe, the liquid temperature in the liquid outlet pipe, and the actual oil pressure in the oil chamber of the retarder in real time, it further includes: adjusting the initial opening degree of the throttle valve to the first opening degree; adjusting the operating parameters of the oil pump according to a preset parameter adjustment rule to increase the oil supply flow rate of the oil pump, and performing the step of obtaining the actual oil pressure in the oil chamber of the retarder in real time; when the current actual oil pressure in the oil chamber of the retarder reaches the current target oil pressure, controlling the oil pump to work with the current operating parameters, and adjusting the current opening degree of the throttle valve to the second opening degree; where the first opening degree is less than the second opening degree.

[0079] Specifically, before the oil temperature in the oil outlet pipe, the liquid temperature in the liquid outlet pipe, and the actual oil pressure in the oil chamber are obtained in real time, it is necessary to first adjust the actual oil pressure in the oil chamber of the retarder to the current target oil pressure to ensure that the retarder can quickly enter a state of stably outputting braking torque. The controller can first adjust the initial opening of the throttle valve to a first opening with a smaller opening to limit the oil flow out of the oil chamber of the retarder, so that the oil in the oil chamber of the retarder accumulates quickly, and the oil pressure in the oil chamber of the retarder can quickly reach the current target oil pressure. At the same time, the controller can adjust the operating parameters of the oil pump according to a preset parameter adjustment rule. Exemplarily, the controller can increase the current of the oil pump to increase the oil supply flow rate of the oil pump in a linear or non-linear manner, so that the oil pressure in the oil chamber of the retarder rises quickly, thereby shortening the time from the start of the retarder to the stable output of braking torque, and improving the timeliness of the braking response of the vehicle hydraulic retarder system. During the process of increasing the oil supply flow rate of the oil pump, the controller can also obtain the actual oil pressure in the oil chamber of the retarder in real time through the oil pressure sensor arranged in the retarder, so as to be able to control the oil pump to work stably with the current operating parameters when the actual oil pressure in the oil chamber of the retarder reaches the current target oil pressure, and no longer adjust the oil supply flow rate of the oil pump. At the same time, to avoid the continuous increase of the oil pressure in the oil chamber of the retarder due to the oil inlet volume being greater than the oil outlet volume, the controller can also adjust the current opening of the throttle valve to a second opening with a larger opening when the current actual oil pressure in the oil chamber of the retarder reaches the current target oil pressure, so as to increase the oil flow out of the oil chamber of the retarder, reduce the net accumulation of oil in the oil chamber of the retarder, and avoid the risk of overpressure caused by the continuous increase of the oil pressure in the oil chamber of the retarder. Thus, it is ensured that the current actual oil pressure in the oil chamber of the retarder can be stabilized at the current target oil pressure, so that the retarder can continuously output stable braking torque, ensure that the expected deceleration effect of the vehicle can be achieved, and improve the smoothness and safety of the driving experience.

[0080] In this embodiment, when the output gear of the transmission drives the input gear of the retarder to start rotating, the current target oil pressure in the oil chamber of the retarder is obtained, so that when it is necessary to generate a braking torque through the retarder, the current target oil pressure in the oil chamber of the retarder can be obtained, providing a basis for dynamically adjusting the opening of the throttle valve and the operating parameters of the oil pump subsequently. By obtaining the oil temperature in the oil outlet pipe, the liquid temperature in the liquid outlet pipe, and the actual oil pressure in the oil chamber of the retarder in real time, it is possible to determine in real time whether the oil temperature in the oil outlet pipe exceeds the oil temperature threshold, whether the liquid temperature in the liquid outlet pipe exceeds the liquid temperature threshold, and whether the current actual oil pressure in the oil chamber of the retarder is maintained at the current target oil pressure. At the same time, by adjusting the opening of the throttle valve and the operating parameters of the oil pump according to the oil temperature in the oil outlet pipe, the liquid temperature in the liquid outlet pipe, and the current actual oil pressure in the oil chamber of the retarder until the current actual oil pressure in the oil chamber of the retarder is at the current target oil pressure, when the oil temperature in the oil outlet pipe exceeds the oil temperature threshold and the liquid temperature in the liquid outlet pipe exceeds the liquid temperature threshold, the opening of the throttle valve can be increased and the operating parameters of the oil pump can be adjusted to increase the amount of oil entering the oil chamber of the retarder through the oil pump, so as to enhance the heat dissipation effect of the heat exchanger and enable the current actual oil pressure in the oil chamber of the retarder to return to the current target oil pressure, thereby maintaining the stability of the oil temperature and oil pressure in the oil chamber of the retarder, ensuring that the retarder can continuously output a stable braking torque, improving the braking ability of the hydraulic retarder system, and at the same time improving the smoothness and safety of the driving experience.

[0081] Embodiment III

[0082] Figure 3 It is a schematic flow chart of a control method for a vehicle hydraulic retarder system provided in Embodiment III of the present invention. On the basis of the above embodiment, the method for adjusting the opening of the throttle valve and the operating parameters of the oil pump according to the oil temperature in the oil outlet pipe, the liquid temperature in the liquid outlet pipe, and the current actual oil pressure in the oil chamber of the retarder is described in detail. Correspondingly, as Figure 3 shown, the control method for the vehicle hydraulic retarder system in this embodiment may include:

[0083] S201. When the output gear of the transmission drives the input gear of the retarder to start rotating, obtain the current target oil pressure in the oil chamber of the retarder.

[0084] S202. Obtain the oil temperature in the oil outlet pipe, the liquid temperature in the liquid outlet pipe, and the actual oil pressure in the oil chamber of the retarder in real time.

[0085] S203. Determine the current change rate of the oil temperature according to the oil temperature in the oil outlet pipe, and determine the current change rate of the liquid temperature according to the liquid temperature in the liquid outlet pipe.

[0086] Specifically, after the controller obtains the oil temperature in the oil outlet pipe and the liquid temperature in the liquid outlet pipe in real time, the controller can calculate the current change rate of the oil temperature based on the oil temperature in the oil outlet pipe. The change rate of the oil temperature can be specifically understood as the change amount of the oil temperature in the oil outlet pipe within a certain time period, and can be determined by continuously collecting the oil temperature in the oil outlet pipe at multiple time points and calculating the change of the oil temperature in the oil outlet pipe per unit time. Similarly, the controller can also calculate the current change rate of the liquid temperature based on the liquid temperature in the liquid outlet pipe. The change rate of the liquid temperature can be specifically understood as the change amount of the liquid temperature in the liquid outlet pipe within a certain time period, and can be determined by continuously collecting the liquid temperature in the liquid outlet pipe at multiple time points and calculating the change of the liquid temperature in the liquid outlet pipe per unit time. It can be understood that the current change rate of the oil temperature reflects the heat generation rate of the oil in the oil chamber of the retarder, that is, the heat accumulation speed generated by the oil shear and eddy current effects during the braking process of the retarder. The greater the current change rate of the oil temperature, the faster the oil in the oil chamber of the retarder generates heat, which may cause the oil temperature in the oil chamber of the retarder to rise rapidly. The current change rate of the liquid temperature reflects the heat dissipation capacity of the heat exchanger, that is, the efficiency of the heat exchanger to absorb and dissipate the heat of the oil through the coolant. The greater the current change rate of the liquid temperature, the faster the temperature of the coolant rises per unit time, indicating that the heat dissipation capacity of the heat exchanger is insufficient and cannot dissipate the absorbed heat to the outside in time, resulting in the continuous rise of the coolant temperature. By determining the current change rate of the oil temperature and the current change rate of the liquid temperature, the controller can comprehensively master the heat generation rate of the oil in the oil chamber of the retarder and the heat dissipation capacity of the heat exchanger in the vehicle hydraulic retarder system, laying a foundation for subsequent adjustment of the throttle valve opening and the operating parameters of the oil pump.

[0087] S204. Determine the current rate ratio between the current change rate of the oil temperature and the current change rate of the liquid temperature according to the current change rate of the oil temperature and the current change rate of the liquid temperature.

[0088] Specifically, after the controller determines the current change rate of the oil temperature and the current change rate of the liquid temperature, the controller can further calculate the ratio between the current change rate of the oil temperature and the current change rate of the liquid temperature, that is, the current rate ratio. It can be understood that the current change rate of the oil temperature reflects the heat generation rate of the oil in the oil chamber of the retarder, and the current change rate of the liquid temperature reflects the heat dissipation rate of the heat exchanger. Therefore, the current rate ratio represents the ratio between the heat generation rate of the oil in the oil chamber of the retarder and the heat dissipation rate of the heat exchanger. If the current rate ratio is too large, it indicates that the change rate of the oil temperature in the outlet pipe is much greater than the change rate of the liquid temperature in the liquid outlet pipe, that is, the heat generation rate of the oil in the oil chamber of the retarder is much higher than the heat dissipation rate of the heat exchanger, and the heat exchanger cannot dissipate the heat generated by the oil in the oil chamber of the retarder in time, which may cause the oil temperature in the oil chamber of the retarder to rise rapidly, increasing the risk of overheating; if the current rate ratio is small, it means that the heat dissipation rate of the heat exchanger can better match or exceed the heat generation rate of the oil in the oil chamber of the retarder, and the rise of the oil temperature in the oil chamber of the retarder can be effectively controlled. Through the current rate ratio, the controller can intuitively quantify the dynamic balance relationship between the heat generation rate of the oil in the oil chamber of the retarder and the heat dissipation rate of the heat exchanger, providing a data basis for adjusting the opening of the throttle valve and the operating parameters of the oil pump in the subsequent stage.

[0089] S205. Adjust the opening of the throttle valve and the operating parameters of the oil pump according to the current oil temperature in the outlet pipe, the current liquid temperature in the liquid outlet pipe, the current rate ratio, and the current actual oil pressure in the oil chamber of the retarder until the current actual oil pressure in the oil chamber of the retarder is at the current target oil pressure.

[0090] Specifically, after the controller obtains the oil temperature in the outlet pipe, the liquid temperature in the liquid outlet pipe, the current rate ratio, and the actual oil pressure in the oil chamber of the retarder in real time, it can adjust the opening of the throttle valve and the operating parameters of the oil pump according to the current oil temperature in the outlet pipe, the current liquid temperature in the liquid outlet pipe, the current rate ratio, and the current actual oil pressure in the oil chamber of the retarder to maintain the stability of the oil temperature in the oil chamber of the retarder, and can maintain the oil pressure in the oil chamber of the retarder at the current target oil pressure, avoiding the limitation of the braking torque output by the retarder due to too high oil temperature and the oil pressure fluctuation in the oil chamber of the retarder, ensuring that the retarder can continuously output a stable braking torque, and improving the braking ability of the hydraulic retarder system.

[0091] Optionally, according to the current oil temperature in the oil outlet pipe, the current liquid temperature in the liquid outlet pipe, the current speed ratio, and the current actual oil pressure in the oil chamber of the retarder, adjust the opening degree of the throttle valve and the operating parameters of the oil pump until the current actual oil pressure in the oil chamber of the retarder is at the current target oil pressure, including: when the current oil temperature in the oil outlet pipe is greater than or equal to the preset oil temperature threshold, the current liquid temperature in the liquid outlet pipe is greater than or equal to the preset liquid temperature threshold, and the current speed ratio is greater than the preset speed ratio threshold, determine the target opening degree of the throttle valve; adjust the current opening degree of the throttle valve to the target opening degree; adjust the operating parameters of the oil pump according to the preset parameter adjustment rule to increase the oil supply flow rate of the oil pump, and return to execute the step of obtaining the actual oil pressure in the oil chamber of the retarder in real time; when the current actual oil pressure in the oil chamber of the retarder reaches the current target oil pressure, control the oil pump to work with the current operating parameters.

[0092] Specifically, the controller can compare the current oil temperature in the oil outlet pipe, the current liquid temperature in the liquid outlet pipe, and the current speed ratio obtained in real time with their respective preset thresholds. When the current oil temperature in the oil outlet pipe is greater than or equal to the preset oil temperature threshold, the current liquid temperature in the liquid outlet pipe is greater than or equal to the preset liquid temperature threshold, and the current speed ratio is greater than the preset speed ratio threshold, it indicates that the current oil temperature in the oil outlet pipe is too high, the current liquid temperature in the liquid outlet pipe is too high, and the heat generation rate of the oil in the oil chamber of the retarder is greater than the heat dissipation rate of the heat exchanger. At this time, the retarder has a risk of overheating, which may cause the braking torque output by the retarder to be limited. Therefore, the controller determines the target opening degree of the throttle valve and adjusts the current opening degree of the throttle valve to the target opening degree. Exemplarily, the target opening degree can be the maximum opening degree of the throttle valve, that is, the third opening degree, to maximize the oil discharge amount in the oil chamber of the retarder, so that more high-temperature oil can flow into the heat exchanger, enhancing the heat dissipation ability of the retarder, thereby reducing the overheating risk of the retarder. Among them, the preset oil temperature threshold, the preset liquid temperature threshold, and the preset speed ratio threshold can be set according to actual needs, and the embodiments of the present invention do not make specific limitations on this.

[0093] After increasing the current opening degree of the throttle valve, to maintain the oil pressure stability in the oil chamber of the retarder, the controller can also adjust the operating parameters of the oil pump according to the preset parameter adjustment rule. Exemplarily, the controller can increase the current of the oil pump to increase the oil supply flow rate of the oil pump linearly or non-linearly to increase the amount of oil entering the oil chamber of the retarder. At the same time, the controller can also obtain the actual oil pressure in the oil chamber of the retarder in real time through the oil pressure sensor arranged in the retarder. When the current actual oil pressure in the oil chamber of the retarder reaches the current target oil pressure, control the oil pump to work stably with the current operating parameters and no longer adjust the oil supply flow rate of the oil pump, avoiding the oil pressure drop in the oil chamber of the retarder caused by the increase in the oil discharge amount, ensuring that the current actual oil pressure in the oil chamber of the retarder can be stabilized at the current target oil pressure, so that the retarder can continuously output a stable braking torque, improving the smoothness and safety of the driving experience.

[0094] Optionally, when the current actual oil pressure in the oil chamber of the retarder reaches the current target oil pressure, controlling the oil pump to operate with the current operating parameters further includes: when the current oil temperature in the oil outlet pipe is less than a preset oil temperature threshold, or the current liquid temperature in the liquid outlet pipe is less than a preset liquid temperature threshold, or the current rate ratio is less than or equal to a preset rate ratio threshold, adjusting the current opening degree of the throttle valve to a second opening degree; adjusting the operating parameters of the oil pump according to a preset parameter adjustment rule to reduce the oil supply flow rate of the oil pump, and then returning to execute the step of obtaining the actual oil pressure in the oil chamber of the retarder in real time; when the current actual oil pressure in the oil chamber of the retarder reaches the current target oil pressure, controlling the oil pump to operate with the current operating parameters.

[0095] Specifically, after the controller increases the opening degree of the throttle valve and the oil supply flow rate of the oil pump to make the current actual oil pressure in the oil chamber of the retarder reach the current target oil pressure, the controller can continue to obtain in real time the current oil temperature in the oil outlet pipe, the current liquid temperature in the liquid outlet pipe, and the current rate ratio between the current change rate of the oil temperature and the current change rate of the liquid temperature. When the controller detects that the current oil temperature in the oil outlet pipe is less than the preset oil temperature threshold, or the current liquid temperature in the liquid outlet pipe is less than the preset liquid temperature threshold, or the current rate ratio is less than or equal to the preset rate ratio threshold, it indicates that the over-temperature risk of the retarder has been lifted, the heat generation rate of the oil in the oil chamber of the retarder is balanced with the heat dissipation rate of the heat exchanger or the heat dissipation rate of the heat exchanger is dominant, and the oil temperature in the oil outlet pipe and the liquid temperature in the liquid outlet pipe are within a safe range. At this time, the controller reduces the opening degree of the throttle valve from a larger opening degree, such as a third opening degree, to a second opening degree to reduce the oil discharge amount in the oil chamber of the retarder, thereby reducing the heat dissipation load of the heat exchanger. After reducing the current opening degree of the throttle valve, to maintain the stability of the oil pressure in the oil chamber of the retarder, the controller can also adjust the operating parameters of the oil pump according to a preset parameter adjustment rule. Exemplarily, the controller can reduce the oil supply flow rate of the oil pump in a linear or non-linear manner by reducing the current of the oil pump to reduce the amount of oil entering the oil chamber of the retarder. At the same time, the controller can also obtain the actual oil pressure in the oil chamber of the retarder in real time through the oil pressure sensor installed in the retarder. When the current actual oil pressure in the oil chamber of the retarder reaches the current target oil pressure, the oil pump is controlled to operate stably with the current operating parameters, and the oil supply flow rate of the oil pump is no longer adjusted, avoiding the increase in the oil pressure in the oil chamber of the retarder caused by the reduction of the oil discharge amount, ensuring that the current actual oil pressure in the oil chamber of the retarder can be stabilized at the current target oil pressure, so that the retarder can continuously output a stable braking torque, and improving the smoothness and safety of the driving experience.

[0096] Optionally, after adjusting the opening degree of the throttle valve and the operating parameters of the oil pump according to the oil temperature in the oil outlet pipe, the liquid temperature in the liquid outlet pipe, and the current actual oil pressure in the oil chamber of the retarder until the current actual oil pressure in the oil chamber of the retarder is at the current target oil pressure, it further includes: when the input gear of the retarder stops rotating, adjusting the current opening degree of the throttle valve to the maximum opening degree; adjusting the operating parameters of the oil pump according to a preset parameter adjustment rule to reduce the oil supply flow rate of the oil pump until the oil supply flow rate of the oil pump is adjusted to 0.

[0097] Specifically, when the driver pushes the retarder control handle back to the 0th gear, it indicates that the braking torque generated by the retarder is no longer required. At this time, the output gear of the transmission no longer transmits the adjusted vehicle engine power to the input gear of the retarder, causing the input gear of the retarder to stop rotating, and the oil in the oil chamber of the retarder no longer needs to continue to generate shear force and eddy current effect. To quickly drain the remaining oil in the oil chamber of the retarder, the controller can adjust the current opening degree of the throttle valve to the maximum opening degree, that is, the third opening degree, to maximize the oil discharge volume of the oil chamber of the retarder, so that the oil in the oil chamber of the retarder quickly flows into the heat exchanger through the oil outlet pipe and finally enters the oil sump. At the same time, it can also adjust the operating parameters of the oil pump according to a preset parameter adjustment rule. Exemplarily, the controller can reduce the current of the oil pump to 0 so that the oil supply flow rate of the oil pump can be reduced to 0 in a linear or non-linear manner, so that the oil pump stops supplying oil to the oil chamber of the retarder, ensuring that no new oil enters the oil chamber of the retarder, thereby accelerating the oil drainage process, avoiding the oil pressure residue or continuous increase in oil temperature in the oil chamber of the retarder caused by oil retention, reducing the heat load and mechanical wear of the retarder in the non-working state, extending the service life of each component in the vehicle hydraulic retarder system, and improving the stability of the vehicle hydraulic retarder system.

[0098] In this embodiment, by determining the current change rate of the oil temperature based on the oil temperature in the oil outlet pipe and the current change rate of the liquid temperature based on the liquid temperature in the liquid outlet pipe, the controller can comprehensively understand the heat generation rate of the oil in the oil chamber of the retarder and the heat dissipation capacity of the heat exchanger in the vehicle hydraulic retarder system. And by determining the current rate ratio between the current change rate of the oil temperature and the current change rate of the liquid temperature, when the current oil temperature in the oil outlet pipe is greater than or equal to the preset oil temperature threshold, the current liquid temperature in the liquid outlet pipe is greater than or equal to the preset liquid temperature threshold, and the current rate ratio is greater than the preset rate ratio threshold, the controller can adjust the current opening degree of the throttle valve to the target opening degree, enhancing the heat dissipation capacity of the retarder, thereby reducing the over-temperature risk of the retarder, and can adjust the operating parameters of the oil pump according to the preset parameter adjustment rule to increase the oil supply flow rate of the oil pump, ensuring that the current actual oil pressure in the oil chamber of the retarder can be stabilized at the current target oil pressure. At the same time, when the current oil temperature in the oil outlet pipe is less than the preset oil temperature threshold, or the current liquid temperature in the liquid outlet pipe is less than the preset liquid temperature threshold, or the current rate ratio is less than or equal to the preset rate ratio threshold, the controller can also reduce the opening degree of the throttle valve from a larger opening degree to the second opening degree, so that when the over-temperature risk of the retarder is eliminated, the oil discharge amount in the oil chamber of the retarder can be reduced, thereby reducing the heat dissipation load of the heat exchanger, and can adjust the operating parameters of the oil pump according to the preset parameter adjustment rule to reduce the oil supply flow rate of the oil pump, ensuring that the current actual oil pressure in the oil chamber of the retarder can be stabilized at the current target oil pressure, enabling the retarder to continuously output a stable braking torque and improving the smoothness and safety of the driving experience. In addition, when the input gear of the retarder stops rotating, the controller can adjust the current opening degree of the throttle valve to the maximum opening degree and can adjust the oil supply flow rate of the oil pump to 0, reducing the heat load and mechanical wear of the retarder in the non-working state and extending the service life of each component in the vehicle hydraulic retarder system.

[0099] Embodiment 4

[0100] An embodiment of the present invention provides a vehicle, which includes a vehicle frame, an engine disposed within the vehicle frame, and the vehicle hydraulic retarder system of the above embodiment.

[0101] Therefore, the vehicle provided in this embodiment has the structure and operation of the vehicle hydraulic retarder system of the above embodiment and can achieve the effects of the control method of the vehicle hydraulic retarder system of the above embodiment. The same parts can be referred to the above description and will not be repeated here.

[0102] It should be understood that the various forms of processes shown above can be used, with steps reordered, added or deleted. For example, the steps described in the present invention can be executed in parallel, sequentially or in different orders, as long as the desired results of the technical solutions disclosed in the present invention can be achieved, and no limitation is imposed herein.

[0103] The above specific embodiments do not constitute a limitation on the protection scope of the present invention. Those skilled in the art should understand that various modifications, combinations, sub - combinations and substitutions can be made according to design requirements and other factors. Any modifications, equivalent substitutions and improvements made within the spirit and principle of the present invention shall be included within the protection scope of the present invention.

Claims

1. A control method for a vehicle hydraulic retarder system, characterized in that: The hydraulic retarder system comprises a retarder, a transmission and a heat exchanger; the input shaft of the transmission is connected to the output shaft of the vehicle engine, and the output gear of the transmission is meshed with the input gear of the retarder; the oil inlet of the oil chamber in the retarder is communicated with the oil inlet pipe, and the oil outlet of the oil chamber in the retarder is communicated with the oil outlet pipe; an oil pump is arranged in the oil inlet pipe; a throttle valve is arranged in the oil outlet pipe; and the heat exchanger is arranged in the path of the oil outlet pipe; The liquid inlet of the heat exchanger is connected to the liquid inlet pipe, and the liquid outlet of the heat exchanger is connected to the liquid outlet pipe; the control method of the hydraulic retarder system includes: When the output gear of the transmission drives the input gear of the retarder to start rotating, obtaining the current target oil pressure of the oil chamber in the retarder; Real-time acquisition of the oil temperature in the oil outlet pipe, the liquid temperature in the liquid outlet pipe, and the actual oil pressure in the oil chamber of the retarder; According to the oil temperature in the oil outlet pipe, the liquid temperature in the liquid outlet pipe and the current actual oil pressure in the oil chamber of the retarder, the opening of the throttle valve and the operating parameters of the oil pump are adjusted until the current actual oil pressure in the oil chamber of the retarder is at the current target oil pressure.

2. The control method of the vehicle hydraulic retarder system according to claim 1, characterized in that: When the output gear of the transmission drives the input gear of the retarder to start rotating, obtaining the current target oil pressure of the oil chamber in the retarder includes: When the output gear of the transmission drives the input gear of the retarder to start rotating, obtaining a current rotation speed of the input gear of the retarder and a current braking torque percentage signal of the vehicle; Acquire a mapping relationship between the rotation speed of the input gear of the retarder, the braking torque percentage signal of the vehicle, and the target oil pressure of the oil chamber in the retarder; According to the mapping relationship, a target oil pressure corresponding to the current rotational speed and the current braking torque percentage signal is determined as the current target oil pressure of the oil chamber in the retarder.

3. The control method of the vehicle hydraulic retarder system according to claim 1, characterized in that: Before obtaining the oil temperature in the oil outlet pipe, the liquid temperature in the liquid outlet pipe, and the actual oil pressure in the oil chamber of the retarder in real time, the method further includes: adjusting the initial opening of the throttle valve to a first opening; The operating parameters of the oil pump are adjusted according to a preset parameter adjustment rule to increase the oil supply flow of the oil pump, and the actual oil pressure of the oil chamber in the retarder is obtained in real time; When the current actual oil pressure of the oil chamber in the retarder reaches the current target oil pressure, the oil pump is controlled to operate with current operating parameters, and the current opening of the throttle valve is adjusted to a second opening; wherein the first opening is smaller than the second opening.

4. The control method of the vehicle hydraulic retarder system according to claim 1, characterized in that: According to the oil temperature in the oil outlet pipe, the liquid temperature in the liquid outlet pipe and the current actual oil pressure in the oil chamber of the retarder, adjusting the opening of the throttle valve and the operating parameters of the oil pump until the current actual oil pressure in the oil chamber of the retarder is at the current target oil pressure, including: Determining a current rate of change of the oil temperature according to the oil temperature in the oil outlet pipe, and determining a current rate of change of the liquid temperature according to the liquid temperature in the liquid outlet pipe; determining a current rate ratio between the current rate of change of the oil temperature and the current rate of change of the liquid temperature according to the current rate of change of the oil temperature and the current rate of change of the liquid temperature; According to the current oil temperature in the oil outlet pipe, the current liquid temperature in the liquid outlet pipe, the current speed ratio and the current actual oil pressure in the oil chamber in the retarder, the opening of the throttle valve and the operating parameters of the oil pump are adjusted until the current actual oil pressure in the oil chamber in the retarder is at the current target oil pressure.

5. The control method of the vehicle hydraulic retarder system according to claim 4, characterized in that: According to the current oil temperature in the oil outlet pipe, the current liquid temperature in the liquid outlet pipe, the current speed ratio, and the current actual oil pressure in the oil chamber of the retarder, adjusting the opening of the throttle valve and the operating parameters of the oil pump until the current actual oil pressure in the oil chamber of the retarder is at the current target oil pressure, comprising: When the current oil temperature in the oil outlet pipe is greater than or equal to a preset oil temperature threshold, the current liquid temperature in the liquid outlet pipe is greater than or equal to a preset liquid temperature threshold, and the current speed ratio is greater than a preset speed ratio threshold, determining a target opening of the throttle valve; adjusting the current opening of the throttle valve to the target opening; adjusting the operating parameters of the oil pump according to a preset parameter adjustment rule to increase the oil supply flow of the oil pump, and returning to execute the step of obtaining the actual oil pressure of the oil chamber in the retarder in real time; When the current actual oil pressure of the oil chamber in the retarder reaches the current target oil pressure, the oil pump is controlled to operate with current operating parameters.

6. The control method of the vehicle hydraulic retarder system according to claim 5, characterized in that: When the current actual oil pressure of the oil chamber in the retarder reaches the current target oil pressure, after controlling the oil pump to operate with the current operating parameters, the method further includes: When the current oil temperature in the oil outlet pipe is less than the preset oil temperature threshold, or the current liquid temperature in the liquid outlet pipe is less than the preset liquid temperature threshold, or the current speed ratio is less than or equal to the preset speed ratio threshold, adjusting the current opening of the throttle valve to a second opening; adjusting the operating parameters of the oil pump according to a preset parameter adjustment rule to reduce the oil supply flow of the oil pump, and returning to execute the step of obtaining the actual oil pressure of the oil chamber in the retarder in real time; When the current actual oil pressure of the oil chamber in the retarder reaches the current target oil pressure, the oil pump is controlled to operate with current operating parameters.

7. The control method of the vehicle hydraulic retarder system according to claim 1, characterized in that: After adjusting the opening of the throttle valve and the operating parameters of the oil pump according to the oil temperature in the oil outlet pipe, the liquid temperature in the liquid outlet pipe and the current actual oil pressure in the oil chamber of the retarder until the current actual oil pressure in the oil chamber of the retarder is at the current target oil pressure, the method further includes: When the input gear of the retarder stops rotating, adjusting the current opening of the throttle valve to the maximum opening; The operating parameters of the oil pump are adjusted according to a preset parameter adjustment rule to reduce the oil supply flow rate of the oil pump until the oil supply flow rate of the oil pump is adjusted to 0.

8. A vehicle hydraulic retarder system, characterized in that: include: Retarder, transmission, heat exchanger and controller; The input shaft of the transmission is connected to the output shaft of the vehicle engine, and the output gear of the transmission is meshed with the input gear of the retarder; The oil inlet of the oil chamber in the retarder is communicated with the oil inlet pipe, and the oil outlet of the oil chamber in the retarder is communicated with the oil outlet pipe; an oil pump is arranged in the oil inlet pipe; a throttle valve is arranged in the oil outlet pipe; The heat exchanger is arranged in the path of the oil outlet pipe; the liquid inlet of the heat exchanger is connected to the liquid inlet pipe, and the liquid outlet of the heat exchanger is connected to the liquid outlet pipe; The controller is respectively connected to the input gear of the retarder, the oil pump and the throttle valve, and the controller is used to execute the control method of the vehicle hydraulic retarder system as described in any one of claims 1-7.

9. The vehicle hydraulic retarder system according to claim 8, characterized in that: Also includes: Oil sump, oil pressure sensor, oil temperature sensor and fluid temperature sensor; One end of the oil inlet pipe and one end of the oil outlet pipe are both located in the oil pool; The oil pool is used to store oil; The oil pressure sensor is arranged in the retarder, and is used to obtain the oil pressure of the oil chamber in the retarder; The oil temperature sensor is arranged in the oil outlet pipe, and the oil temperature sensor is used to obtain the oil temperature in the oil outlet pipe; The liquid temperature sensor is arranged in the liquid outlet pipe, and the liquid temperature sensor is used to obtain the liquid temperature in the liquid outlet pipe; The controller is also connected to the oil pressure sensor, the oil temperature sensor and the liquid temperature sensor respectively, and is also used to obtain the oil pressure in the oil chamber in the retarder based on the oil pressure sensor, the oil temperature in the oil outlet pipe based on the oil temperature sensor, and the liquid temperature in the liquid outlet pipe based on the liquid temperature sensor.

10. A vehicle, characterized in that: include: A vehicle frame, an engine arranged in the vehicle frame, and a vehicle hydraulic retarder system as claimed in any one of claims 8 to 9.

Images