An electrically controlled trolley power operation system and method

Abstract

The application discloses a kind of electric car power running system and method based on electrical control, it is related to electric car technical field, including electric control hydraulic subsystem, trailer hook device and control unit.In the application, when the traction hook is stressed, it will pull the poking component, the round boss in poking component pokes travel switch, travel switch converts mechanical signal into electrical signal and transmits to control unit, and control unit controls electric control hydraulic subsystem operation according to the electrical signal received, to realize the intelligent release and recovery of axle brake, this way avoids the complex pipeline arrangement in hydraulic control, can realize trailer function in minimum space, it is convenient to access whole vehicle electrical system to realize real-time display alarm, less fault is convenient to overhaul, accumulator cooperates with pressure switch to make system energy saving and pressure stable, it can also be perfectly combined with original vehicle braking system, and do not affect each other.

Description

Technical Field

[0001] This invention belongs to the field of tram technology, specifically, it relates to a tram power operation system and method based on electrical control. Background Technology

[0002] With the continuous development of new energy-driven methods, higher requirements are being placed on the power operation system of electric vehicles. Traditional electric vehicle power operation systems, especially those involving trailer functions, mostly rely on pure hydraulic control methods. For example, in the prior art, Chinese patent number CN104442411A discloses a regenerative braking and hydraulic hybrid braking system applied to a tractor. This control method has revealed many drawbacks in long-term application: From a spatial layout perspective, the complex hydraulic pipeline layout not only occupies a large amount of valuable interior space, greatly limiting the overall design and layout of the vehicle, but also increases the difficulty of installation and maintenance. In terms of system functionality, pure hydraulic control is difficult to seamlessly integrate with the vehicle's electrical control system, and cannot perform real-time data display and fault alarms, resulting in untimely and inaccurate monitoring of the vehicle's operating status, posing potential risks to operational safety. Moreover, the hydraulic system itself has many potential failure points, and once a fault occurs, the troubleshooting and repair process is cumbersome, consuming a lot of time and manpower. Summary of the Invention

[0003] The technical problem to be solved by the present invention is to overcome the shortcomings of the prior art and provide an electric vehicle power operation system based on electrical control that can overcome or at least partially solve the above problems.

[0004] To solve the above-mentioned technical problems, the basic concept of the technical solution adopted by this invention is: an electric control-based tram power operation system, comprising: an electro-hydraulic subsystem for converting mechanical signals into electrical signals and realizing the release and restoration of tram axle braking through electrical signals; a trailer hitch device, located at the rear of the tram frame, for connecting towing vehicles; and a control unit for detecting the force state of the trailer hitch device and controlling the operation of the electro-hydraulic subsystem; the electro-hydraulic subsystem specifically includes: a solenoid valve for receiving electrical signals and controlling the flow direction of hydraulic oil; an electric pump, controlled by electrical signals to start and stop, for pumping hydraulic oil; an accumulator for storing and releasing hydraulic oil; and a pressure switch for... The system includes: a pressure detection system and a control system for starting and stopping the electric pump based on the detection results; a check valve located at the outlet of the electric pump; an axle brake located within the axle assembly, which controls the clamping force between the brake friction pads and the brake disc via hydraulic oil pressure; a foot brake valve connected in series in the hydraulic circuit to regulate the flow of hydraulic oil into the axle brake; and a battery that powers the electric pump, solenoid valve, pressure switch, and control unit. The trailer hitch assembly includes: a towing hook for connecting to a towing vehicle; an actuation assembly connected between the towing hook and the frame to return the towing hook to its original position after the towing force is released; and a limit switch located near the actuation assembly to detect the force state of the trailer hitch and convert it into an electrical signal.

[0005] In some implementations, the actuation assembly includes a first connecting rod slidably connected to the frame, one end of the first connecting rod being connected to a tow hook, and the other end of the first connecting rod being fixedly connected to a second connecting rod. The end diameter of the second connecting rod is larger than that of the first connecting rod. A return spring sleeved on the first connecting rod is fixedly connected between the second connecting rod and the frame. A circular protrusion for actuating the limit switch is fixedly connected to the surface of the second connecting rod.

[0006] In some implementations, a shearing assembly is provided between the end of the first connecting rod connected to the traction hook and the traction hook, which is used to break the force transmission path when the traction force exceeds the safe range.

[0007] In some implementations, the shearing assembly includes a concave pin seat fixedly connected to one end of the first connecting rod, a shaft pin connected to the concave pin seat, and the traction hook connected to the surface of the shaft pin via a hinge.

[0008] In some implementations, the axle pin includes a multi-layer structure, comprising: an inner layer made of a low-melting-point tin alloy and an outer layer made of high-strength stainless steel. When the traction force exceeds the safe range, the tin alloy layer melts first to absorb part of the overload energy, and then the stainless steel layer breaks to cut off the force transmission path.

[0009] In some implementations, a temperature sensor is installed on the surface of the pin. When the tin alloy layer experiences a local temperature rise during the melting process, the temperature sensor on the pin surface will trigger an alarm.

[0010] In some implementations, the alarm signal from the temperature sensor is transmitted to the control unit, which responds to the signal by executing a control command to reduce the output pressure of the electric pump and constrain the speed of the tram.

[0011] The present invention also provides a method for the operation of a tram based on electrical control, comprising:

[0012] When the towing hook is under force, it will pull the toggle assembly to toggle the limit switch. After receiving the signal, the control unit starts the electric pump, the solenoid valve is energized and reverses, the hydraulic oil enters the axle brake to release the brake, the accumulator stores excess hydraulic oil and replenishes hydraulic oil when the system pressure drops, the pressure switch monitors the system pressure and disconnects the electric pump circuit when the set value is reached.

[0013] When the tractor vehicle brakes to a stop, the force on the towing hook disappears, the actuating component returns to its original position and disconnects the limit switch. After receiving the signal, the control unit de-energizes the solenoid valve and reverses the direction, allowing the hydraulic oil in the axle brake to flow back to the oil tank and restore braking.

[0014] By adopting the above technical solution, the present invention has the following beneficial effects compared with the prior art:

[0015] In this application, when the towing hook is subjected to force, it will pull the actuation component. The circular protrusion in the actuation component will actuate the limit switch. The limit switch will convert the mechanical signal into an electrical signal and transmit it to the control unit. The control unit will control the operation of the electro-hydraulic subsystem according to the received electrical signal, thereby realizing the intelligent release and restoration of the axle brake, and providing an efficient and precise control method for vehicle braking.

[0016] The advantages of this design approach are as follows:

[0017] In terms of space utilization, thanks to the adoption of an integrated electro-hydraulic design, multiple functional components are compactly integrated together, avoiding the complex pipeline layout in traditional hydraulic control. This enables the trailer function to be realized in the smallest space, improving the utilization rate of the vehicle's interior space and providing more space for the layout and functional expansion of other vehicle components.

[0018] In terms of electrical system access, the system has reserved standardized electrical interfaces to facilitate quick and stable connection with the vehicle's electrical system. It can collect system operating status data in real time and display it on the vehicle's display screen. At the same time, it can trigger alarm functions in a timely manner when the system malfunctions, so that operators can keep abreast of the vehicle's operating status and ensure the safe and stable operation of the vehicle.

[0019] In terms of system reliability and maintainability, the system has significantly fewer failure points due to the reduction of complex pipeline connections and mechanical transmission components, making it easier for maintenance personnel to quickly locate and troubleshoot faults. In addition, the accumulator installed in the system can store or release hydraulic energy when the system pressure fluctuates. It works in conjunction with the pressure switch to adjust the working state in real time according to the system pressure, making the system more energy-efficient and with stable pressure.

[0020] More importantly, the electro-hydraulic subsystem of this application is designed with full consideration of compatibility with the original vehicle braking system. Its hydraulic circuit is independent of the original vehicle braking system's hydraulic circuit, ensuring that the hydraulic oil of the two systems will not mix. In terms of electrical control, the control unit adopts independent signal processing logic, only processing signals related to the trailer function, and will not send interference signals to the control module of the original vehicle braking system, thereby achieving a perfect integration with the original vehicle braking system without affecting each other. Attached Figure Description

[0021] In the attached diagram:

[0022] Figure 1 A schematic diagram of the electrical and hydraulic circuit connections of an electric vehicle power operation system based on electrical control, provided for an embodiment of this application;

[0023] Figure 2 for Figure 1 Schematic diagram of the connection structure between the toggle assembly and the limit switch Figure 1 ;

[0024] Figure 3 for Figure 1 Schematic diagram of the connection structure between the toggle assembly and the limit switch Figure 2 ;

[0025] Figure 4 A schematic flowchart of a tram power operation method based on electrical control provided in this application embodiment. Figure 1 ;

[0026] Figure 5 A schematic flowchart of a tram power operation method based on electrical control provided in this application embodiment. Figure 2 .

[0027] In the diagram: 1. Solenoid valve; 2. Foot brake valve; 3. Axle brake; 4. Accumulator; 5. Check valve; 6. Electric pump; 7. Limit switch; 8. Actuating assembly; 81. First connecting rod; 82. Second connecting rod; 83. Return spring; 84. Circular protrusion; 85. Concave pin seat; 86. Shaft pin; 87. Temperature sensor; 9. Towing hook; 10. Battery; 11. Pressure switch. Detailed Implementation

[0028] To make the objectives, technical solutions, and advantages of the embodiments of the present invention clearer, the technical solutions in the embodiments will be clearly and completely described below with reference to the accompanying drawings. The following embodiments are used to illustrate the present invention, but are not intended to limit the scope of the present invention.

[0029] Example 1

[0030] like Figure 1-5 As shown, an electric vehicle power operation system based on electrical control includes an electro-hydraulic subsystem, a trailer hitch device, and a control unit.

[0031] like Figure 1 As shown, the electro-hydraulic subsystem includes a solenoid valve 1, an electric pump 6, an accumulator 4, a pressure switch 11, a check valve 5, an axle brake 3, a foot brake valve 2, and a battery 10.

[0032] Among them, solenoid valve 1, as the core of hydraulic oil flow control, receives electrical signals from the control unit and controls the flow path of hydraulic oil through steering operations to realize the contact and recovery of the axle brake; electric pump 6 is controlled by electrical signals to start and stop, and is responsible for pumping hydraulic oil from the tank to the hydraulic circuit to provide power for brake release; accumulator 4 stores hydraulic oil and releases it when the system needs it to maintain stable pressure in the hydraulic circuit, while reducing the working time of electric pump 6 and improving system energy efficiency; pressure switch 11 detects the pressure in the hydraulic circuit, and disconnects the electric pump 6 circuit when the pressure reaches the set value to prevent overpressure. When the pressure decreases, the circuit is reconnected, and the electric pump 6 is started to replenish the hydraulic oil. The one-way valve 5 is located at the outlet of the electric pump 6 to prevent hydraulic oil from leaking through the electric pump 6 when it is not in use, thus ensuring the safety of the braking system. The axle brake 3 is located inside the axle assembly and controls the clamping force between the brake friction pads and the brake disc through hydraulic oil pressure to achieve vehicle braking. The foot brake valve 2 is connected in series in the hydraulic circuit to regulate the flow of hydraulic oil entering the axle brake 3, thereby controlling the braking intensity. The battery 10 provides power to the electric pump 6, solenoid valve 1, pressure switch 11, and control unit.

[0033] like Figure 1 As shown, the trailer hook device includes a towing hook 9 for connecting to a towing vehicle, an actuation assembly 8, and a limit switch 7 located near the actuation assembly 8 for detecting the force state of the trailer hook and converting it into an electrical signal.

[0034] like Figure 2 and Figure 3As shown, the actuating assembly 8 includes a first connecting rod 81 slidably connected to the frame. One end of the first connecting rod 81 is connected to the tow hook 9, and the other end of the first connecting rod 81 is fixedly connected to a second connecting rod 82. The end diameter of the second connecting rod 82 is larger than the end diameter of the first connecting rod 81. A return spring 83 sleeved on the first connecting rod 81 is fixedly connected between the second connecting rod 82 and the frame. A circular protrusion 84 for actuating the limit switch 7 is fixedly connected to the surface of the second connecting rod 82.

[0035] The control unit is used to detect the stress state of the trailer hook device and control the operation of the electro-hydraulic subsystem according to the received electrical signals, so as to realize the intelligent release and restoration of the axle brake.

[0036] When the towing hook 9 is under force, it pulls the first connecting rod 81 in the actuation assembly 8 to slide on the frame. Since the first connecting rod 81 is connected to the second connecting rod 82, the second connecting rod 82 will move accordingly and compress the return spring 83 during the sliding of the first connecting rod 81. At the same time, the circular protrusion 84 on the second connecting rod 82 will actuate the limit switch 7. After receiving the signal from the limit switch 7, the control unit starts the electric pump 6, which energizes the solenoid valve 1 to reverse. At this time, hydraulic oil enters the axle brake 3, thereby releasing the brake. The accumulator 4 is responsible for storing excess hydraulic oil and replenishing hydraulic oil when the system pressure decreases. The pressure switch 11 continuously monitors the system pressure. When the pressure reaches the set value, the pressure switch 11 will disconnect the electric pump 6 circuit.

[0037] When the tractor vehicle brakes to a stop, the force on the towing hook 9 disappears, and the actuating component 8 returns to its original position under the action of the return spring 83. At the same time, the limit switch 7 is disconnected, and after the control unit receives the signal, the solenoid valve 1 is de-energized and reversed, and the hydraulic oil in the axle brake 3 flows back to the oil tank, thereby restoring braking.

[0038] The system adopts an electro-hydraulic control method, which converts mechanical signals into electrical signals to control the electric pump 6 and the solenoid valve 1 to switch. This avoids the complex pipeline layout in hydraulic control and enables towing function in a minimal space. Moreover, this method is more convenient to connect to the vehicle's electrical control system to achieve real-time display and alarm. At the same time, there are fewer fault points, making maintenance easier. The accumulator 4 and pressure switch 11 work together to make the system more energy-efficient and pressure stable.

[0039] Furthermore, while utilizing the original vehicle's system resources, this system does not affect the original vehicle's braking system, achieving a perfect integration with the original vehicle system.

[0040] Example 2

[0041] Based on the above embodiment one, this embodiment improves the towing hook 9 to further enhance the safety and stability of the system under complex traction conditions, such as... Figure 2 and Figure 3 As shown, the first connecting rod 81 is connected to one end of the traction hook 9 and a shearing assembly is provided between the first connecting rod 81 and the traction hook 9. The purpose of the shearing assembly is to break in time to cut off the force transmission path when the traction force exceeds the safe range, so as to avoid serious damage to the entire tram power operation system due to excessive traction force.

[0042] The shearing assembly includes a concave pin seat 85 fixedly connected to one end of the first connecting rod 81, a shaft pin 86 connected to the concave pin seat 85, and a traction hook 9 connected to the surface of the shaft pin 86 by a hinge. The shaft pin 86 includes a multi-layer structure, wherein the inner layer is made of a low melting point tin alloy and the outer layer is made of high strength stainless steel.

[0043] Under normal traction conditions, pin 86 can stably transmit traction force, ensuring a reliable connection between the tram and the traction vehicle. However, when the traction force exceeds the safe range, the low-melting-point tin alloy layer will melt first. This process can absorb some of the overload energy and play a certain buffering role. Subsequently, the high-strength stainless steel layer will break due to excessive force, thus completely cutting off the force transmission path. This layered fracture design effectively avoids the entire system from being severely impacted by excessive traction force, ensuring the safety of key system components and extending the system's service life.

[0044] This design takes into account the various complex traction conditions that trams may encounter during actual operation, such as sudden acceleration, emergency braking, or travel on uneven surfaces. These situations can cause a sudden increase in traction force, exceeding the system's safe operating range. Without a shearing component, excessive traction force would be directly transmitted to various components of the tram's power system, such as the electro-hydraulic subsystem and axle brakes 3, potentially causing damage such as hydraulic line rupture or axle brake 3 failure. This would severely affect the normal operation of the vehicle and could even lead to safety accidents. The addition of axle pin 86, however, mitigates this risk. When the load is applied, the risk source can be directly and physically isolated. When the shaft pin 86 breaks and cuts off the force transmission path, the electric pump 6 will not start and stop frequently due to excessive traction force, avoiding increased power consumption and aggravated equipment wear caused by frequent start and stop. At the same time, it also reduces the possibility of hydraulic oil leakage and prevents braking instability caused by hydraulic system fluctuations. In addition, as a disposable safety component, the shaft pin 86 can restore system function by simply replacing the new shaft pin 86 after it breaks, without the need for a comprehensive overhaul of the entire complex system. Compared with hydraulic system leakage or solenoid valve 1 failure, the maintenance cost of the shaft pin 86 is lower and the efficiency is higher, which greatly improves the maintainability of the system.

[0045] Example 3

[0046] Based on the above embodiment two, this embodiment further optimizes the system by adding a temperature monitoring function to improve the safety and stability of the system under abnormal operating conditions. A temperature sensor 87 is installed on the surface of the axle pin 86. When the traction force exceeds the safe range and the tin alloy layer begins to melt, a local temperature rise will occur. The temperature sensor 87 will quickly detect this temperature change and immediately transmit an alarm signal to the control unit. The control unit responds to the signal and quickly executes the control command to reduce the output pressure of the electric pump 6 and constrain the travel speed of the tram. By reducing the output pressure of the electric pump 6, the pressure shock inside the system can be reduced, avoiding damage to other components due to excessive pressure. Constraining the travel speed can reduce the kinetic energy of the vehicle, reduce the additional traction force caused by inertia, and further reduce the load on the system.

[0047] In Embodiment 2, although the layered fracture design of the axle pin 86 can cut off the force transmission path when the traction force exceeds the safe range, the local temperature rise during the melting process of the tin alloy layer may have a thermal effect on the surrounding components, and may even cause other potential problems. For example, high temperature may cause changes in the properties of the surrounding hydraulic oil, affecting the normal operation of the hydraulic system, or damage nearby electrical components, affecting the electrical control function of the system.

[0048] By installing temperature sensor 87, the temperature change during the melting process of the tin alloy layer can be monitored in real time, and potential abnormalities in the system can be detected in advance. The control unit can make timely adjustments based on the temperature signal, such as reducing the output pressure of electric pump 6 and restricting the driving speed. This can effectively avoid a series of problems caused by excessive temperature and further reduce the operating risk of the system under abnormal conditions. From the perspective of temperature monitoring and system control, it provides more comprehensive safety protection for the entire electric vehicle power operation system and further improves the stability and reliability of the system.

[0049] like Figure 4 and Figure 5 As shown, the present invention also provides a method for the operation of a tram based on electrical control, comprising:

[0050] When the towing hook 9 is under force, it will pull the toggle assembly 8 to toggle the limit switch 7. After receiving the signal, the control unit starts the electric pump 6, the solenoid valve 1 is energized and reverses, the hydraulic oil enters the axle brake 3 to release the brake, the accumulator 4 stores the excess hydraulic oil and replenishes the hydraulic oil when the system pressure drops, the pressure switch 11 monitors the system pressure and disconnects the electric pump 6 circuit when the set value is reached.

[0051] When the tractor vehicle brakes to a stop, the force on the towing hook 9 disappears, the actuating component 8 returns to its original position and disconnects the limit switch 7. After receiving the signal, the control unit de-energizes the solenoid valve 1 and reverses the direction, and the hydraulic oil in the axle brake 3 flows back to the oil tank, restoring braking.

[0052] The above description is merely a preferred embodiment of the present invention and is not intended to limit the present invention in any way. Although the present invention has been disclosed above with reference to preferred embodiments, it is not intended to limit the present invention. Any person skilled in the art can make some modifications or alterations to the above-described technical content to create equivalent embodiments without departing from the scope of the present invention. Any simple modifications, equivalent changes, and alterations made to the above embodiments based on the technical essence of the present invention without departing from the scope of the present invention shall still fall within the scope of the present invention.

Claims

1. A tram power operation system based on electrical control, comprising: An electro-hydraulic subsystem, used to convert mechanical signals into electrical signals and to release and restore the braking of the tram axle via these electrical signals, is characterized by further comprising: A trailer hitch device is located at the rear of the tram frame and is used to connect to a towing vehicle; The control unit is used to detect the force state of the trailer hook device and control the operation of the electro-hydraulic subsystem. The electro-hydraulic subsystem specifically includes: Solenoid valve (1) is used to receive electrical signals and control the flow of hydraulic oil; The electric pump (6) is controlled by an electrical signal to start and stop, and is used to pump hydraulic oil. Accumulator (4) is used to store and release hydraulic oil; Pressure switch (11) is used to detect system pressure and control the start and stop of electric pump according to the detection result; A check valve (5) is installed at the outlet of the electric pump (6); The axle brake (3) is installed in the axle assembly and controls the clamping force between the brake friction pads and the brake disc by hydraulic oil pressure. Foot brake valve (2), connected in series in the hydraulic circuit, is used to regulate the flow of hydraulic oil entering the axle brake (3); The battery (10) supplies power to the electric pump (6), solenoid valve (1), pressure switch (11) and control unit; A trailer hitch device is located at the rear of the tram frame and is used to connect to a towing vehicle; The trailer hitch device includes: Towing hook (9), used to connect towing vehicles; The actuating component (8) is connected between the towing hook (9) and the frame and is used to return the towing hook (9) to its original position after the trailer force is lost. Limit switch (7), located near toggle assembly (8), is used to detect the force state of trailer hook and convert it into an electrical signal; The first connecting rod (81) is connected to one end of the traction hook (9) and a shearing assembly is provided between the traction hook (9) and the first connecting rod (81). The shearing assembly is used to break when the traction force exceeds the safe range to cut off the force transmission path. The shearing assembly includes a concave pin seat (85) fixedly connected to one end of the first connecting rod (81). A shaft pin (86) is connected to the concave pin seat (85). The traction hook (9) is connected to the surface of the shaft pin (86) by a hinge. The pivot pin (86) includes a multi-layer structure, the multi-layer structure comprising: The inner layer is made of a low-melting-point tin alloy; The outer layer is made of high-strength stainless steel; When the traction force exceeds the safe range, the tin alloy layer melts first to absorb part of the overload energy, and then the stainless steel layer breaks to cut off the force transmission path. A temperature sensor (87) is installed on the surface of the pin (86). When the tin alloy layer generates a local temperature rise during the melting process, the temperature sensor (87) installed on the surface of the pin (86) will be triggered to alarm.

2. The electric vehicle power operation system based on electrical control according to claim 1, characterized in that, The actuating assembly (8) includes a first connecting rod (81) slidably connected to the frame. One end of the first connecting rod (81) is connected to the tow hook (9). The other end of the first connecting rod (81) is fixedly connected to a second connecting rod (82). The end diameter of the second connecting rod (82) is larger than the end diameter of the first connecting rod (81). A return spring (83) sleeved on the first connecting rod (81) is fixedly connected between the second connecting rod (82) and the frame. A circular protrusion (84) for actuating the limit switch (7) is fixedly connected to the surface of the second connecting rod (82).

3. The electric vehicle power operation system based on electrical control according to claim 1, characterized in that, The alarm signal from the temperature sensor (87) is transmitted to the control unit, which responds to the signal by executing a control command to reduce the output pressure of the electric pump (6) and constrain the speed of the tram.

4. A method for the operation of a tram based on electrical control, applied to the tram power operation system based on electrical control as described in claim 1, characterized in that, include: When the towing hook (9) is under force, it will pull the toggle assembly (8) to toggle the limit switch (7). After receiving the signal, the control unit starts the electric pump (6), the solenoid valve (1) is energized and reverses, the hydraulic oil enters the axle brake (3) to release the brake, the accumulator (4) stores excess hydraulic oil and replenishes hydraulic oil when the system pressure decreases, the pressure switch (11) monitors the system pressure and disconnects the electric pump (6) circuit when the set value is reached; When the tractor vehicle stops braking, the force on the towing hook (9) disappears, the toggle assembly (8) returns to its original position and disconnects the limit switch (7). After receiving the signal, the control unit de-energizes the solenoid valve (1) and reverses the direction, and the hydraulic oil in the axle brake (3) flows back to the oil tank, restoring braking.

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