CN106368870A - Temperature control system of in-cylinder direct injection gasoline injector - Google Patents

Abstract

A temperature control system for an in-cylinder direct-injection gasoline injector, including a temperature control module installed in the injector and an engine control unit installed in the driver's cab. Compared with the optimum fuel temperature, the engine control unit controls the power supply to apply the required heating electric power to the heating cylinder to achieve accurate closed-loop control of the optimum fuel temperature.

Description

Temperature Control System of In-Cylinder Direct Injection Gasoline Injector

technical field

The invention relates to a gasoline engine fuel injector, in particular to a temperature control system for an in-cylinder direct-injection gasoline fuel injector.

Background technique

The wide application of direct injection system of gasoline engine enhances the transient response ability of gasoline engine and improves its fuel economy at the same time. However, the problems of difficult start-up of direct-injection gasoline engines under cold start conditions and excessive emission of exhaust particulate matter have always been the focus of research in academic and industrial circles. Studies have shown that properly raising the fuel temperature to achieve fuel flash spray can significantly improve the fuel atomization and evaporation effects under low fuel injection pressure conditions, reduce gasoline engine exhaust emissions, and improve fuel economy.

At present, all such technologies for heating fuel oil basically realize the open-loop heating of the fuel temperature through the material properties of the electric adder system itself, that is, design an electric heating module inside the nozzle, and use the resistance characteristics of PTC ceramics to heat the fuel. . Although this solution can significantly improve the effect of fuel atomization and evaporation, it needs to be designed separately for different engine structures, which increases the complexity and cost of nozzle design. In addition, the accuracy of fuel temperature is low and cannot be really applied to product engines. middle. There are the following problems:

1. The ceramic material PTC characteristic is used to heat the fuel, the ambient temperature is low at the start-up stage, and the resistance heating speed is slow;

2. Open-loop heating using the characteristics of ceramic materials cannot accurately control the fuel temperature;

3. The heating mechanism needs to be designed separately for different engines, and the versatility is poor.

Contents of the invention

The technical problem to be solved by the present invention is to provide a temperature control system for in-cylinder direct injection gasoline injectors, which can accurately collect the fuel temperature of the gasoline injector and compare it with the optimum fuel temperature. The power supply applies the required heating electric power to the heating cylinder to realize the accurate closed-loop control of the optimum fuel temperature.

In order to realize the purpose of the present invention, technical scheme of the present invention is as follows:

A temperature control system for an in-cylinder direct injection gasoline injector, which is characterized in that the temperature control system includes a temperature control module arranged on the fuel injector and an engine control unit arranged on the engine compartment, and the in-cylinder direct injection gasoline The needle valve of the fuel injector moves axially in the guide tube through the bottom-up valve seat, needle valve guide seat, heating cylinder insulating pad, temperature control module and armature. The needle valve external self-heating cylinder Above the insulating mat is the temperature control module, the temperature control module is an insulating gasket, a heating cylinder and a temperature control block with a temperature sensor from bottom to top, the heating cylinder has electrodes, and the heating cylinder has electrodes. The temperature control block is provided with a wiring port, the temperature sensor is connected to the engine control unit through the wiring port, the electrode is connected to the power supply through the wiring port, and the engine control unit The needle valve temperature is collected in real time through the temperature sensor, and the current fuel temperature is obtained according to the calibration; the target fuel temperature in the working environment is calculated, and compared with the current fuel temperature, the heating electric power required for heating the cylinder is calculated and controlled, so as to reach the target temperature.

The beneficial effects of the present invention are:

1. Outside the needle valve of the present invention is the temperature control module. The temperature control module consists of an insulating gasket, a heating cylinder and a temperature control block with a temperature sensor from bottom to top. The heating cylinder There are electrodes, and a wiring port is provided on the temperature control block, and the temperature sensor is connected with the engine control unit through the wiring port, and the temperature sensor collects the fuel temperature in real time, and the engine control unit can Accurately collect the fuel temperature and compare it with the optimal fuel temperature to achieve accurate closed-loop control of the optimal fuel temperature;

2. The needle valve is used as the heating carrier, which improves the heating efficiency and directly controls the fuel temperature at the outlet of the nozzle;

Description of drawings

Fig. 1 is a schematic cross-sectional view of the overall structure of the fuel injector designed in the present invention.

Figure 2 is a schematic diagram of the structure of the heating cylinder, a is a top view, and b is a main view.

Fig. 3 is a structural schematic diagram of a heating control module.

Fig. 4 is a schematic diagram of the wiring terminals of the heating module.

In the figure, 1-valve seat, 2-needle valve guide seat, 3-fuel temperature control assembly, 4-buffer spring, 5-armature, 6-preload spring seat , 7-preload spring, 8-electromagnetic coil terminal , 9- Heating module wiring terminal, 10- Heating cylinder insulating pad, 11- Needle valve, 12- Guide pipe, 3-1 Temperature control module, 3-2 Heating cylinder, 3-3 Insulating gasket, 3-4 Wiring Ports; 3-2-1 Heating Bath, 3-2-2 Electrodes.

detailed description

In order to make the object, technical solution and advantages of the present invention clearer, the present invention will be further described in detail below in combination with specific examples and with reference to the accompanying drawings.

Please refer to FIG. 1 first. FIG. 1 is a cross-sectional view of the overall structure of the fuel injector involved in the present invention. As can be seen from the figure, the temperature control system of the direct injection gasoline injector in the cylinder of the present invention includes a fuel temperature control assembly 3 arranged on the injector and an engine control unit (not shown) arranged on the engine compartment, the described The needle valve 11 of the in-cylinder direct injection gasoline injector is bound in the guide tube 12 along the inner edge of the guide pipe 12 through the bottom-up valve seat 1, the needle valve guide seat 2, the heating cylinder insulation pad 10, the fuel temperature control assembly 3 and the armature 5. Axial movement, above the needle valve 11 outer self-heating cylinder insulation pad 10 is the temperature control module 3, the fuel temperature control assembly 3 is the insulation gasket 3-3, the heating cylinder 3-2 and a temperature control block 3-1 with a temperature sensor, the heating cylinder 3-2 has an electrode 3-2-2, and a wiring port 3-1 is provided on the temperature control block 3-1 4. The temperature sensor is connected to the engine control unit through the wiring port 3-4, the electrode 3-2-2 is connected to the power supply through the wiring port 3-4, and the The engine control unit collects the needle valve temperature in real time through the temperature sensor, and obtains the current fuel temperature according to the calibration; calculates the target fuel temperature in this working environment, and compares it with the current fuel temperature to calculate the heating required for the heating cylinder 3-2 Electric power is controlled to achieve the target temperature.

The needle valve guide seat 2 is located inside the spray hole and is used to limit the position of the needle valve 11, and the axial movement of the needle valve 11 controls the movement of the steel ball (at the bottom of the needle valve). The temperature sensor is located in the fuel temperature control assembly 3 for real-time feedback of fuel temperature. When the electromagnetic attraction force is greater than the pre-tightening force of the pre-tightening spring 7 and the system resistance, the moving part composed mainly of the needle valve and the armature moves along the axial direction bound by the guide tube 12, and the needle valve 11 and the needle valve guide seat 2 The contact surface disengages, resulting in an oil injection action, and with the upward movement of the needle valve, the preload spring is compressed by the needle valve and the preload spring seat 7 to limit the maximum lift of the needle valve; when the preload force of the preload spring 7 is greater than the electromagnetic suction force and the system resistance When combined force, needle valve 11 descends, and the steel ball at the lower end of needle valve 11 is in contact with the contact surface of needle valve guide seat 2 again, and the fuel injection stops, and buffer spring 4 assists needle valve 11 to be stationary.

Fig. 2 is a schematic diagram of the structure of the heating cylinder, which is composed of a heating cylinder 3-2, a heating tank 3-2-1 and an electrode 3-2-2. The electrode 3-2-2 is connected with the power supply to provide electric heating for the heating cylinder 3-2, and the fuel oil flows through the heating tank 3-2-1 and is heated by the heating cylinder 3-2 to realize the control of the fuel oil temperature.

Fig. 3 is a structural schematic diagram of the heating control module. The fuel temperature control assembly 3 consists of an insulating gasket 3-3, a heating cylinder 3-2 and a temperature control block 3-1 with a temperature sensor from bottom to top. The temperature control module first Receive the fuel temperature target signal from the ECU and the fuel temperature signal fed back by the temperature sensor, process and calculate the above signals, and then output the control signal to the heating control module to form a closed-loop control loop to accurately control the fuel temperature.

Figure 4 is the connection part of this design and external electrical appliances. The solenoid valve terminal 8 receives the boost circuit signal from the ECU for controlling the needle valve lift, and the heating module terminal 9 is used to receive the target fuel temperature signal given by the ECU. .

The object of the present invention is to quantitatively change the fuel temperature, because different fuel temperatures lead to different fuel sprays, so it is necessary to adjust the fuel temperature to achieve the best fuel spray configuration. The specific working process is as follows:

The high-pressure fuel flows into the cavity surrounded by the guide pipe 12 and the valve seat 2. With the operation of the engine, under the action of the solenoid valve, the needle valve 11 is sucked up together with the armature 5, and the high-pressure fuel flows from the bottom of the injector at a high The speed is injected into the cylinder;

1. The fuel temperature control assembly 3 collects the temperature of the fuel in real time and feeds it back to the engine control unit;

2. The engine control unit calculates the optimal target fuel temperature of the fuel under the operating conditions according to the operating conditions of the engine;

3. The engine control unit adjusts the temperature of the needle valve by controlling the voltage at both ends of the armature 5, so as to realize the function of changing the fuel temperature;

4. The temperature of the fuel flowing into the injector cavity is low. If there is no external heating, the temperature of the fuel will cool down quickly;

When the target fuel temperature is higher than the current measured fuel temperature, the control unit increases the power provided to the needle valve 11 to rapidly heat up to realize the increase of the fuel temperature;

Compared with conventional gasoline injectors, the present invention adds a closed-loop fuel control system, specifically embodied in Figures 2-4, through the temperature feedback of the temperature sensor, and the monitoring of the engine speed and load, etc., to determine the current state of the engine. In the working state, according to the prior data obtained from previous experiments, the fuel temperature can be precisely controlled to produce the target spray pattern.

Claims (1)

1. a kind of temperature control system of in-cylinder direct-jet gasoline ejector is it is characterised in that this temperature control system includes being arranged on fuel injector Temperature control modules (3) and the control unit of engine being arranged on engine bin, the pin of described in-cylinder direct-jet gasoline ejector Valve (11) is by valve seat (1) from bottom to top, needle-valve guide holder (2), heating cylinder felt pad (10), fuel oil temperature control assembly (3) and armature (5) is strapped in guide pipe (12) axially movable, described needle-valve (11) outer self-heating cylinder felt pad (10) On be described fuel oil temperature control assembly (3), this fuel oil temperature control assembly (3) is insulating washer from bottom to top successively (3-3), heating cylinder (3-2) and the temperature control modules (3-1) being provided with temperature sensor, described heating cylinder (3-2) has There is electrode (3-2-2), Wiring port (3-4) is provided with described temperature control modules (3-1), described temperature sensor is led to Cross described Wiring port (3-4) to be connected with described control unit of engine, described electrode (3-2-2) passes through described connecing Line end mouth (3-4) is connected with power supply, and described control unit of engine passes through temperature sensor Real-time Collection needle-valve temperature, and root Obtain current fuel temperature according to nominal data；Calculate the Targeted fuel temperature under this working environment, and with current fuel temperature Contrast, calculates the heating electric power needed for heating cylinder (3-2) and is controlled by, to reach target temperature.