A range extended vehicle fueled by natural gas

Abstract

This utility model discloses a range-extended electric vehicle (REEV) fueled by natural gas, belonging to the field of natural gas vehicle technology. It mainly includes a vehicle body and wheels. A front subframe is located at the front of the vehicle body, and a rear axle is located at the rear. A natural gas range extender is housed in the front compartment of the vehicle body and is suspended on the front subframe. The crankshaft of the range extender faces the same direction as the vehicle's travel. The front subframe is connected to the vehicle body and the front wheels via MacPherson strut suspension. A gas cylinder and a power battery are fixedly connected to the bottom of the vehicle body. The gas cylinder is connected to the range extender via pipelines. A drive motor is located on the rear axle, and the power battery powers the drive motor. This utility model converts the energy of natural gas into electrical energy, stores it in the power battery, and then uses it to drive the motor to propel the vehicle. It possesses the characteristics of good responsiveness and strong power of electric vehicles, fundamentally solving the shortcomings of low energy density and weak power of natural gas-fueled vehicles.

Description

Technical Field

[0001] This utility model belongs to the field of natural gas vehicle technology, and more specifically, it relates to a range-extended vehicle that uses natural gas as fuel. Background Technology

[0002] Natural gas, as a fuel, emits fewer pollutants and is cheaper than gasoline and diesel. Vehicles using natural gas significantly reduce fuel costs for users, especially in Sichuan, Xinjiang, and Gansu provinces in my country, where it holds a considerable market share. However, natural gas has a low energy density, resulting in noticeable power shortages when vehicles are fully loaded, climbing hills, or overtaking. Furthermore, in low-temperature environments, the vaporization of natural gas is less efficient, leading to unstable fuel supply and difficulty starting the engine.

[0003] Patent publication number CN118618037A discloses a vehicle range extender power system, control method, and vehicle, including a generator, a gas engine, a fuel supply device, and a controller. The controller acquires the pressure value within the fuel supply device and, if the pressure value meets preset operating conditions, determines whether to start the gas engine. If it is determined that the gas engine needs to be started, the target torque requirement is acquired, and the gas flow rate of the fuel supply device is controlled based on the target torque requirement. This addresses the problem of low efficiency in gas range extenders through software control.

[0004] However, the above solution still has the following shortcomings: 1. The integration of the fuel supply device (air tank, pressure regulator, valve) and the range extender system (engine, generator) will occupy a lot of chassis space, affecting the interior layout or luggage compartment volume, especially with poor adaptability to compact models; 2. The setting of multi-stage valves and sensors increases the system complexity and will lead to more failure points. For example, failure of high-pressure solenoid valve or differential pressure sensor requires professional equipment for detection, which increases after-sales maintenance costs and the threshold for user use. Utility Model Content

[0005] The technical problem to be solved by this utility model is to overcome the shortcomings of the prior art and provide a range-extended electric vehicle that uses natural gas as fuel. The energy from burning natural gas is not directly used to drive the vehicle. Instead, the energy of natural gas is converted into electrical energy and stored in the power battery before driving the motor to drive the vehicle. It has the characteristics of good responsiveness and strong power of electric vehicles, and fundamentally solves the shortcomings of low energy density and weak power of natural gas fuel vehicles.

[0006] The aforementioned range-extended electric vehicle (REEV) using natural gas as fuel includes a body and wheels. A front subframe is located at the front of the body, and a rear axle is located at the rear of the body. A natural gas range extender is located in the front compartment of the body and is mounted on the front subframe. The crankshaft of the natural gas range extender is oriented in the same direction as the vehicle's travel. The front subframe is connected to the body and the front wheels via MacPherson strut suspension. A gas cylinder and a power battery are fixedly connected to the bottom of the body. The gas cylinder is connected to the natural gas range extender via pipelines. A drive motor is located on the rear axle, and the power battery supplies power to the drive motor.

[0007] Preferably, the rear axle adopts a leaf spring suspension and is an integrated electric drive axle, with the drive motor and the rear axle forming a "Y" shape.

[0008] Preferably, the gas range extender includes a gas engine, a generator, a flywheel, and a torsional damper. The flywheel is fixedly connected to the rear end of the crankshaft of the gas engine, the torsional damper is fixedly connected to the flywheel, the power input end of the generator is connected to the torsional damper, and the generator is fixedly connected to the gas engine.

[0009] Preferably, the gas engine is provided with a gas injection rail on top, and the pipeline on the gas cylinder is connected to the gas injection rail via a pressure regulating valve and a gas filter. The gas injection rail is connected to the intake manifold on the cylinder head of the gas engine.

[0010] Preferably, the gas engine is a 2.0L naturally aspirated four-stroke gas engine, and the generator is connected to the power battery.

[0011] Preferably, a gas cylinder bracket is fixedly connected to the bottom of the vehicle body, the gas cylinder is fixedly mounted on the gas cylinder bracket, and the gas cylinder and the power battery are arranged side by side.

[0012] Preferably, it also includes a generator controller (GCU), a vehicle control unit (VCU), a battery management system (BMS), and a motor controller (MCU). The generator controller (GCU) and the vehicle control unit (VCU) are fixedly connected to the vehicle body via brackets, the motor controller (MCU) is connected to the drive motor, and the battery management system (BMS) is integrated into the power battery.

[0013] Compared with the prior art, the beneficial effects of this utility model are:

[0014] 1. The front axle of this utility model adopts a MacPherson strut suspension, the rear axle adopts a leaf spring suspension, the gas range extender is front-mounted and fixed to the front subframe by three-point suspension on the left, right and rear to ensure the stability of the gas range extender installation; and the longitudinal arrangement of the gas range extender and the crankshaft orientation are consistent with the vehicle's direction of travel, which can improve the utilization rate of the vehicle's internal engine compartment space.

[0015] 2. Gas cylinders and power batteries are arranged side by side at the bottom of the vehicle body, which optimizes the use of vehicle space, balances the load on the front and rear axles, improves driving stability, and provides two ways to replenish energy for the vehicle: refueling with natural gas and external charging. In areas where charging is convenient, the vehicle can be directly charged and stored to achieve pure electric driving. In areas where outdoor charging is inconvenient, such as Xinjiang and Gansu, natural gas can be refueled and generated through a gas range extender to achieve electric driving of the vehicle.

[0016] 3. Compared with traditional vehicles that use natural gas as fuel, this utility model adopts the "gas range extender power generation + electric motor drive" mode. That is, the energy of burning natural gas is not directly used to drive the vehicle. Instead, the energy of natural gas is converted into electrical energy and stored in the power battery, and then used to drive the electric motor to drive the vehicle. In other words, there is no linear proportional relationship between the output power of the gas engine and the throttle of the car. Therefore, it has the characteristics of good responsiveness and strong power of electric vehicles, and can fundamentally solve the shortcomings of low energy density and weak power of natural gas fuel vehicles.

[0017] 4. This utility model uses a generator to drive ignition, with a starting speed of over 1000 rpm. The higher the starting speed, the faster the air flow inside the gas engine, and the better the mixing effect of the gas injection with the air, which is more conducive to ignition. At high speeds, more heat is generated by friction and compression inside the cylinder, which helps to increase the cylinder temperature and makes the fuel easier to burn. Compared with traditional vehicles that use natural gas as fuel, it is easier to start the gas engine. Attached Figure Description

[0018] Figure 1 This is a three-dimensional structural diagram of the present invention;

[0019] Figure 2 This is the front view of the present invention;

[0020] Figure 3 This is a top view of the present invention;

[0021] Figure 4 This is a schematic diagram of the breakdown of a gas range extender;

[0022] Figure 5 This is a schematic diagram of the gas injection rail structure;

[0023] Figure 6 This is a schematic diagram of the control strategy of this utility model.

[0024] In the diagram, 1. Gas engine; 2. Generator; 3. Suspension frame; 4. Front subframe; 5. MacPherson strut suspension; 6. Wheel; 7. Generator controller (GCU); 8. Gas cylinder; 801. Gas cylinder bracket; 9. Gas injection rail; 901. Gas pipe; 10. Rear axle; 11. Drive motor; 12. Power battery; 13. Motor controller (MCU); 14. Flywheel; 15. Torsional damper. Detailed Implementation

[0025] The present invention will be further described below with reference to the accompanying drawings:

[0026] The directional terms used in the detailed description paragraphs are only for the convenience of those skilled in the art to understand the technical solutions described in this application based on the visual orientation shown in the accompanying drawings. Unless otherwise expressly specified and limited, the terms "setting," "installation," "connection," etc., should be interpreted broadly, and those skilled in the art can understand the specific meaning of the above terms in this utility model according to the specific circumstances.

[0027] Example 1:

[0028] like Figures 1 to 5 As shown, a range-extended electric vehicle (REEV) using natural gas as fuel includes a body and wheels 6. A front subframe 4 is provided at the front end of the body, and a rear axle 10 is provided at the rear end of the body. The body is a monocoque body. A natural gas range extender is provided in the front compartment of the body. Suspension brackets 3 are fixedly connected to the left, right, and rear sides of the natural gas range extender. The suspension brackets 3 are fixedly connected to the front subframe 4. That is, the natural gas range extender is fixed to the front subframe 4 by suspension at the left, right, and rear three points. The crankshaft of the natural gas range extender is oriented in the same direction as the vehicle's travel direction. That is, the natural gas range extender is longitudinally arranged in the front compartment of the body, and the natural gas engine 1 of the natural gas range extender faces the front end of the vehicle to ensure that the power transmission direction is coordinated with the travel direction.

[0029] In this embodiment, the front axle uses a MacPherson strut suspension 5, and the rear axle 10 uses a leaf spring suspension. The front subframe 4 is connected to the vehicle body and the front wheels 6 via the MacPherson strut suspension 5, providing lightweight and responsive suspension performance. A gas cylinder 8 and a power battery 12 are fixedly connected to the bottom of the vehicle body. The gas cylinder 8 is used to store natural gas fuel, and a gas cylinder bracket 801 is fixedly connected to the bottom of the vehicle body. The gas cylinder 8 is fixed to the bottom of the vehicle body via the gas cylinder bracket 801, and the gas cylinder 8 and the power battery 12 are arranged side by side, optimizing the space utilization of the entire vehicle.

[0030] Gas cylinder 8 is connected to the gas injection rail 9 of the gas range extender via pipeline, pressure regulating valve, and gas filter, ensuring a clean and stable fuel supply within the gas range extender. A drive motor 11 is mounted on the rear axle 10, and a power battery 12 provides energy to the drive motor 11, enabling vehicle propulsion.

[0031] The rear axle 10 adopts a leaf spring suspension, which is suitable for load-bearing requirements. The rear axle 10 is an integrated electric drive axle, which integrates a drive motor 11. The drive motor 11 and the rear axle 10 form a "Y" shape, which simplifies the transmission path and improves efficiency.

[0032] like Figure 4 and Figure 5As shown, the gas range extender includes a gas engine 1, a generator 2, a flywheel 14, and a torsional damper 15. The flywheel 14 is fixedly connected to the rear end of the crankshaft of the gas engine 1, and the torsional damper 15 is fixedly connected to the flywheel 14. The power input end of the generator 2 is connected to the torsional damper 15, and the generator 2 is fixedly connected to the gas engine 1. By linking the torsional damper 15 with the generator 2, the impact of crankshaft torsional vibration on the generator 2 is reduced, ensuring stable power generation.

[0033] The gas engine 1 is equipped with a gas injection rail 9 on top. The pipeline on the gas cylinder 8 is connected to the gas injection rail 9 via a pressure regulating valve and a gas filter. The gas injection rail 9 is connected to the intake manifold on the cylinder head of the gas engine 1 via multiple gas pipes 901, so that natural gas enters the gas injection rail 9 through the pipeline in sequence via the pressure regulating valve and the gas filter. The gas injection rail 9 divides the natural gas from one path into multiple paths, which then enter the intake manifolds corresponding to each cylinder of the gas engine 1. In the intake manifolds, the natural gas is mixed with air to form a mixture, which makes the natural gas burn more completely in the gas engine 1.

[0034] In this embodiment, an MPV van model is preferred. The gas engine 1 is a 2.0L naturally aspirated four-stroke gas engine that can provide a rated power output of 92kw. In conjunction with the generator 2, it can generate a rated power of 50kw. The generator 2 is connected to the power battery 12.

[0035] In this embodiment, a 100L compressed natural gas cylinder 8 and a 27.85kWh power battery 12 are preferably used to form an energy storage device, enabling the vehicle to achieve a range of more than 350km.

[0036] Example 2:

[0037] like Figure 6 As shown, a range-extended electric vehicle (REEV) fueled by natural gas also includes a generator controller (GCU7), a vehicle control unit (VCU), a battery management system (BMS), and a motor controller (MCU13). The generator controller (GCU7) and the vehicle control unit (VCU) are fixedly connected to the vehicle body via brackets. The motor controller (MCU13) is connected to the drive motor (11), meaning the drive motor assembly consists of the drive motor (11) and the motor controller (MCU13), capable of outputting a rated power of 45kW and a peak power of 90kW. The battery management system (BMS) is integrated into the power battery (12). Other aspects are the same as in Embodiment 1.

[0038] The working principle of this utility model is as follows:

[0039] This utility model adopts a monocoque chassis, with a MacPherson strut front axle suspension 5 and a leaf spring rear axle 10. The gas range extender is front-mounted, and the drive motor 11 is rear-mounted, classifying it as a rear-wheel drive vehicle. The gas range extender consists of a gas engine 1 and a generator 2 connected by bolts via a flywheel 14 and a torsional damper 15, achieving a mode where the gas range extender generates electricity and the motor drives the vehicle. That is, the gas range extender does not directly drive the vehicle; it only activates when the power battery 12 is low on charge or when the vehicle's power demand exceeds the power battery 12's discharge capacity. It charges the power battery 12 or directly provides energy to the drive motor 11. In other words, the electrical energy provided by the power battery 12 or the gas range extender is converted into mechanical energy by the drive motor 11, enabling the vehicle to move.

[0040] By setting up a gas cylinder 8 and a power battery 12, this utility model can achieve two energy replenishment methods: natural gas refueling and external charging. In areas where charging is convenient, it can directly charge and store energy to start the drive motor 11. The power battery 12 supplies power to the drive motor 11, enabling the vehicle to drive purely on electricity. In areas where outdoor charging is inconvenient, such as Xinjiang and Gansu, natural gas can be refueled. The natural gas enters the gas injection rail 9 through the pipeline, passing through the pressure regulating valve and the gas filter. The gas injection rail 9 divides the natural gas from one path into multiple paths, which then enter the intake manifolds corresponding to each cylinder of the gas engine 1. In the intake manifolds, the natural gas mixes with air to form a mixture, allowing the natural gas to burn completely in the gas engine 1. The energy generated by the combustion of natural gas drives the flywheel 14, the torsional damper 15, and the generator 2 to rotate in sequence. The rotor in the generator 2 rotates in the stator, cutting magnetic field lines and generating an induced electromotive force to discharge externally, charging the power battery 12. In other words, it generates electricity through the gas range extender, which can also enable the vehicle to drive electrically.

[0041] Compared to traditional vehicles fueled by natural gas, this invention does not directly drive the vehicle using the energy from burning natural gas. Instead, it converts the energy of natural gas into electrical energy, stores it in the power battery 12, and then uses the electrical motor to drive the vehicle. This means there is no linear proportional relationship between the output power of the gas engine 1 and the vehicle's throttle, thus giving it the advantages of good responsiveness and strong power characteristic of electric vehicles. This fundamentally solves the problems of low energy density and weak power in natural gas-fueled vehicles. To reduce costs, a smaller power battery 12 can be used, thereby achieving higher power output at a lower cost for natural gas vehicles.

[0042] Traditional natural gas-powered vehicles use a starter motor for ignition, with a starting speed of approximately 300-400 rpm. This invention, however, uses a generator 2 for ignition, achieving a starting speed above 1000 rpm. Higher starting speeds result in faster airflow inside the gas engine 1, leading to better mixing of the injected gas with air and thus facilitating ignition. The increased heat generated by cylinder friction and compression at higher speeds further raises the cylinder temperature, making fuel combustion easier. In short, the gas engine 1 is easier to start compared to traditional natural gas-powered vehicles.

[0043] like Figure 6 As shown, the vehicle control unit (VCU) sends commands to the battery management system (BMS) and the motor controller (MCU13) based on the actual operating conditions of the vehicle and pedal requests. This causes the power battery (12) to provide energy to the drive motor (11), which then converts electrical energy into mechanical energy and transmits it to the wheels (6) through the transmission system, thereby driving the vehicle. Due to the inherent characteristics of the drive motor (11), it can output maximum torque instantly upon startup, unlike traditional engines which rely on engine speed to achieve maximum torque output. Therefore, whether starting from 0 or accelerating while moving, its power delivery is faster than that of traditional vehicles, improving the insufficient power problem caused by traditional gas engines (1) and providing a better driving experience.

[0044] Once the start-up conditions for the gas range extender are met, the vehicle control unit (VCU) controls the generator controller (GCU) to start the gas engine 1 at different target speeds based on the coolant temperature request of the gas engine 1. The specific starting speeds are shown in the table below. The VCU then determines and matches the jet start-up conditions based on the starting speed to ensure successful ignition.

[0045] Engine coolant temperature / °C -30 -20 -15 -7 0 30 and above Drag speed / rpm 1350 1300 1250 1200 1100 1000

[0046] At higher engine speeds, a better ignition environment can be created in the combustion chamber, making it easier to start the engine of this invention compared to traditional vehicles fueled by natural gas.

[0047] Finally, although this specification describes embodiments, not every embodiment contains only one independent technical solution. This way of describing the specification is only for clarity. Those skilled in the art should regard the specification as a whole. The technical solutions in each embodiment can also be appropriately combined to form other embodiments that can be understood by those skilled in the art.

Claims

1. A range-extended vehicle fueled by natural gas, comprising a vehicle body and vehicle wheels (6), the front end of the vehicle body is provided with a front subframe (4), and the rear end of the vehicle body is provided with a rear axle (10), characterized in that: A gas range extender is installed in the front compartment of the vehicle body. The gas range extender is mounted on the front subframe (4). The crankshaft of the gas range extender is oriented in the same direction as the vehicle's travel. The front subframe (4) is connected to the vehicle body and the front wheels (6) respectively through MacPherson strut suspension (5). A gas cylinder (8) and a power battery (12) are fixedly connected to the bottom of the vehicle body. The gas cylinder (8) is connected to the gas range extender through a pipeline. A drive motor (11) is installed on the rear axle (10). The power battery (12) supplies power to the drive motor (11).

2. The range extended vehicle fueled by natural gas according to claim 1, characterized in that: The rear axle (10) adopts a leaf spring suspension and is an integrated electric drive axle. The drive motor (11) and the rear axle (10) are in a "Y" shape.

3. The range extended vehicle of claim 1, wherein: The gas range extender includes a gas engine (1), a generator (2), a flywheel (14), and a torsional damper (15). The flywheel (14) is fixedly connected to the rear end of the crankshaft of the gas engine (1), the torsional damper (15) is fixedly connected to the flywheel (14), the power input end of the generator (2) is connected to the torsional damper (15), and the generator (2) is fixedly connected to the gas engine (1).

4. The range extended vehicle of claim 3, wherein: The gas engine (1) is equipped with a gas injection rail (9) on top. The pipeline on the gas cylinder (8) is connected to the gas injection rail (9) via a pressure regulating valve and a gas filter. The gas injection rail (9) is connected to the intake manifold on the cylinder head of the gas engine (1).

5. The range extended vehicle of claim 4, wherein: The gas engine (1) is a 2.0L naturally aspirated four-stroke gas engine, and the generator (2) is connected to the power battery (12).

6. The range extended vehicle of claim 1, wherein: A gas cylinder bracket (801) is fixedly connected to the bottom of the vehicle body. The gas cylinder (8) is fixedly installed on the gas cylinder bracket (801), and the gas cylinder (8) and the power battery (12) are arranged side by side.

7. The range extended vehicle fueled by natural gas according to any one of claims 1 to 6, characterized in that: It also includes a generator controller GCU (7), a vehicle control unit VCU, a battery management system BMS, and a motor controller MCU (13). The generator controller GCU (7) and the vehicle control unit VCU are fixedly connected to the vehicle body through a bracket. The motor controller MCU (13) is connected to the drive motor (11). The battery management system BMS is integrated into the power battery (12).

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