CN109026476A - The variable pressure accumulation type piezoelectric fuel injector of fuel injection characteristic - Google Patents

Abstract

The object of the present invention is to provide a pressure accumulator piezoelectric fuel injector with variable fuel injection rules, which includes a pressure boost control valve part, a three-stage piston assembly, a fuel injection control valve part and a needle valve part. The invention adopts a boost control valve structure to control the boost area of the three-stage piston, which can effectively realize different boost ratios and make the fuel injection rule more flexible; the action process of the needle valve is driven by the piezoelectric stack, and the needle valve responds Fast speed, large degree of control freedom, flexible and controllable fuel injection rules, effectively improving the power and fuel economy of the diesel engine, enabling the diesel engine to meet more stringent emission regulations; in addition, the pressure accumulator chamber can slow down the pressure caused by fuel injection Fluctuation is beneficial to the precise control of fuel injection volume, especially for small fuel volume control accuracy can be significantly improved, the pressure stabilization effect of the pressure storage chamber reduces the size of the common rail pipe, prolonging the service life of the common rail pipe.

Description

Accumulator Piezoelectric Injector with Variable Injection Law

technical field

The invention relates to a diesel engine, in particular to a diesel engine fuel system.

Background technique

Mechanical fuel injectors have disadvantages such as inflexible fuel injection characteristics, slow response, and poor control accuracy of fuel injection volume due to the fuel injection characteristics such as fuel injection timing, fuel injection pressure and fuel injection rate being restricted by the cam of the high-pressure fuel supply pump. With the increasingly stringent emission regulations, it is difficult to further improve the economy and emission of the engine.

Compared with the mechanical injector, the electromagnetic control injector applied to the electronic control fuel injection system of diesel engine has faster response speed, flexible and controllable fuel injection characteristics, and more precise control of fuel injection quantity. Although the electromagnetic control injector has improved the emission performance of the diesel engine, there are still some shortcomings: the injector usually adopts the form of single-way oil inlet, and the response speed of the needle valve seat is slow, and due to the balance of the diameter of the inlet and outlet holes relationship, it is difficult to further improve the response characteristics; the dynamic oil return in the form of a two-position two-way valve is large, which affects fuel utilization; the axial gap between the needle valve and the control plunger causes static leakage in the injector Fuel problem; due to the inductance of the solenoid valve coil, there is a certain lag time in its response, which leads to further increase in the number of fuel injections is limited, and the repeatability of fuel injection needs to be improved; in the state of large fuel injection, the fuel injection of each cylinder Process uniformity and stability decline, etc.

Contents of the invention

The object of the present invention is to provide a pressure accumulator piezoelectric fuel injector with variable fuel injection rules capable of flexibly controlling the boost ratio to achieve different injection effects.

The purpose of the present invention is achieved like this:

The pressure accumulator piezoelectric fuel injector with variable fuel injection rules of the present invention is characterized in that it includes a fuel injector body, a pressure accumulator chamber wall, a pressure boost control valve part, a three-stage piston assembly, a fuel injection control valve part, a needle The valve part and the wall of the pressure accumulator are fixed above the injector body, the pressure boost control valve part and the three-stage piston assembly are installed in the injector body from top to bottom, and the fuel injection control valve part and the needle valve part pass through its external The nozzle tight cap is installed under the three-stage piston assembly, and a pressure storage chamber is opened in the wall of the pressure storage chamber, and the pressure storage chamber is connected to the high-pressure oil circuit;

The boost control valve part includes a piezoelectric stack, a boost control valve stem, a mushroom sleeve, a hydraulic core, a boost control valve stem sleeve, a piezoelectric stack sleeve, and a mushroom sleeve limit orifice , the booster piston limit orifice, the piezoelectric stack sleeve, the mushroom sleeve limit orifice and the booster piston limit orifice are set from top to bottom, the hydraulic core is installed in the hydraulic sleeve, the piezoelectric stack, hydraulic pressure The sleeve and the booster control valve stem sleeve are arranged in the piezoelectric stack sleeve from top to bottom, and the booster control valve stem is installed in the booster control valve stem sleeve, and the upper end of the booster control valve stem extends into the To the hydraulic sleeve and form a hydraulic oil chamber with the hydraulic core, the pressure boost control valve cavity is set in the limit orifice of the fungus sleeve, the fungus sleeve is set in the pressure boost control valve cavity, the boost control valve The lower end of the valve stem extends into the mushroom sleeve, and a plate spring is installed on the outside of the hydraulic sleeve. The bottom end of the plate spring is pressed above the stem sleeve of the booster control valve, and the upper end of the plate spring is pressed against the upper end of the hydraulic sleeve. , the middle part of the booster control valve stem is provided with a booster control valve stem protrusion, a booster control valve stem spring is set between the booster control valve stem protrusion and the fungus sleeve, and the cone surface of the fungus sleeve A sleeve spring is set between the lower end and the limit orifice of the booster piston, an oil return circuit and a first-stage booster oil circuit are set on the stem sleeve of the booster control valve, and an increaser is set on the limit orifice of the mushroom sleeve. The pressure orifice, the pressure booster piston limit orifice is provided with a secondary booster oil circuit, the primary booster oil channel is connected to the valve chamber of the booster control valve through the passage in the middle of the fungus sleeve, and the oil return circuit is connected to the low pressure oil. The booster orifice is respectively connected to the high-pressure oil circuit and the valve chamber of the booster control valve, and the secondary booster oil circuit is connected to the valve chamber of the booster control valve;

The three-stage piston assembly includes a booster piston and a piston return spring. The booster piston is a three-stage stepped cylinder structure, which are respectively the first-third cylinders from top to bottom, and the diameters are decreasing. The first cylinder and its A piston cavity is formed between the upper booster piston limiting orifice, and the piston cavity is connected to the high-pressure oil circuit through the hole in the booster piston limiting orifice. A first-stage pressurization chamber, a second-stage pressurization chamber is formed between the second and third cylinders and the injector body, a third-stage pressurization chamber is formed between the third cylinder and the injector body below, and three Piston return spring is installed in the stage booster chamber, the first stage booster chamber is connected to the first stage booster oil circuit, the second stage booster chamber is connected to the second stage booster oil circuit, and the third stage booster chamber is connected to the high pressure oil circuit through a check valve , there is a pressurized oil passage at the lower part of the three-stage pressurized chamber;

The fuel injection control valve part includes a fuel injection control valve piezoelectric stack, a fuel injection control valve hydraulic sleeve, a fuel injection control valve stem sleeve, a fuel injection control valve stem, a fuel injection control valve limit orifice, an umbrella The piston, the middle orifice plate, the fuel injection control valve piezoelectric stack, the fuel injection control valve hydraulic sleeve and the fuel injection control valve stem sleeve are arranged in the injector body from top to bottom, and the fuel injection control valve hydraulic sleeve is provided with a nozzle. The hydraulic core of the oil control valve and the valve stem of the fuel injection control valve are installed in the sleeve of the valve stem of the fuel injection control valve, and the upper end of the valve stem of the fuel injection control valve extends into the hydraulic sleeve of the fuel injection control valve and forms a hydraulic oil cavity , the fuel injector body, the limit orifice plate of the fuel injection control valve, and the middle orifice form the cavity of the fuel injection control valve, the umbrella-shaped piston is installed in the cavity of the fuel injection control valve, and the lower end of the valve stem of the fuel injection control valve is pressed against the umbrella-shaped On the piston, the return spring of the fuel injection control valve is installed between the lower end of the cone surface of the umbrella-shaped piston and the middle orifice plate, and the oil injection control valve plate spring is installed outside the hydraulic sleeve of the fuel injection control valve, and the plate spring of the fuel injection control valve The bottom end is pressed above the stem sleeve of the fuel injection control valve, and the upper end of the plate spring of the fuel injection control valve is pressed against the upper end of the hydraulic sleeve of the fuel injection control valve. The oil circuit and the oil inlet hole, the limit orifice of the fuel injection control valve is provided with a low-pressure oil drain hole, and the low-pressure oil drain hole is respectively connected to the low-pressure oil circuit and the valve chamber of the fuel injection control valve;

The needle valve part includes a needle valve limit orifice plate and a needle valve block. The needle valve limit orifice plate and the needle valve block are arranged under the middle orifice plate from top to bottom, and the upper cavity of the hydraulic compensation piston is set in the middle orifice plate Oil circuit, check channel, check valve is installed in the check channel, the oil inlet circuit in the upper chamber of the hydraulic compensation piston is connected to the high-pressure oil circuit, the check channel is connected to the oil inlet hole, and hydraulic compensation is set in the needle valve limit hole Piston, control chamber oil circuit, the hydraulic compensation piston is covered with a hydraulic compensation piston return spring, the upper end of the hydraulic compensation piston return spring is on the hydraulic compensation piston, and the lower end of the hydraulic compensation piston return spring is on the bottom On the limit orifice plate of the needle valve, the upper chamber of the hydraulic compensation piston is formed above the hydraulic compensation piston, which communicates with the oil inlet passage of the upper chamber of the hydraulic compensation piston. The position of the return spring of the hydraulic compensation piston is the lower chamber of the hydraulic compensation piston. A hydraulic compensation piston drain chamber is formed between the lower end of the hydraulic compensation piston and the needle valve limit orifice below it, and the oil passage in the control chamber is connected to the oil inlet hole; a needle valve is installed in the needle valve block, and a needle valve is set on the upper part of the needle valve Return spring, the upper end of the needle valve return spring is against the needle valve limit orifice, the lower end of the needle valve return spring is against the needle valve, the position of the needle valve return spring is the control chamber, and the control chamber is connected to the oil circuit of the control chamber. The needle valve block is provided with an oil tank inlet circuit, and an oil tank is formed between the needle valve and the needle valve block. There is a spray hole at the bottom of the needle valve block, and the oil tank inlet circuit is respectively connected to the oil tank and the pressurized oil circuit. The hydraulic compensation piston The lower chamber is connected to the check passage below the check valve through the oil inlet passage of the lower chamber of the hydraulic compensation piston, and the lower chamber of the hydraulic compensation piston is connected to the control chamber through the oil outlet passage of the hydraulic compensation piston.

The present invention may also include:

1. When working in non-pressurized mode, when the fuel injection control valve is partially energized, the piezoelectric stack of the fuel injection control valve presses the hydraulic sleeve of the fuel injection control valve and the hydraulic core of the fuel injection control valve to move downward together, so that the fuel injection control valve The oil pressure in the oil chamber formed by the hydraulic sleeve and the valve stem of the fuel injection control valve rises, and the valve rod of the fuel injection control valve moves downward under the pressure in the oil chamber, thereby pressing the umbrella-shaped piston to overcome the pressure of the return spring of the fuel injection control valve. The elastic force moves downward. At this time, the cone surface at the lower end of the fuel injection control valve stem is sealed, so that the high-pressure oil circuit is cut off. At the same time, the cone surface seal on the upper part of the umbrella piston is opened. The valve chamber of the oil control valve is connected with the low-pressure oil drain hole, and the fuel in the control chamber flows back into the fuel tank through the low-pressure oil drain hole; at the same time, the pressure in the lower chamber of the hydraulic compensation piston in the hydraulic compensation piston decreases accordingly, and the hydraulic compensation The pressure in the upper chamber of the piston is greater than the resultant force formed by the pressure in the lower chamber of the hydraulic compensation piston and the elastic force of the hydraulic compensation piston spring. At this time, the hydraulic compensation piston moves downward, the check valve is closed, and the hydraulic compensation piston is released through the hydraulic compensation piston. The oil circuit supplies oil to the control chamber to slow down the pressure drop in the control chamber; when the resultant force formed by the pressure in the control chamber and the spring force of the needle valve spring is smaller than the upward hydraulic pressure of the fuel in the oil tank, the needle valve lifts upward and the injection hole starts Fuel injection; when the fuel injection control valve is partially powered off, the valve stem of the fuel injection control valve is seated under the elastic force of the return spring of the valve stem of the fuel injection control valve, and the high pressure oil circuit is opened while the low pressure oil drain hole is closed to stop When the return valve is opened, the pressure of the control chamber is rebuilt through the oil inlet hole and the lower chamber of the hydraulic compensation piston. Reseat and stop spraying.

2. When working in low boost mode, the boost control valve is energized, and the piezoelectric stack is extended to the low pressure position under the action of the inverse piezoelectric effect, pressing the hydraulic sleeve and the hydraulic core to move downward together, so that the hydraulic sleeve and the booster The oil pressure in the oil chamber formed by the control valve stem rises, and the booster control valve stem moves downward under the pressure in the oil chamber, and the fungus sleeve opens while the taper surface on the booster control valve stem is sealed open. The barrel closes the channel at the head of the booster control valve stem. At this time, the high-pressure oil circuit is no longer connected to the first-stage booster oil circuit. The oil circuit is connected. The fuel in the first-stage pressurized chamber flows through the first-stage pressurized oil circuit and returns to the low-pressure fuel tank. The sum of the pressure in the pressure chamber and the elastic force of the piston return spring, the booster piston moves downward, and the check valve at the oil inlet of the three-stage booster chamber closes; the fuel injection control valve is partially energized, and the pressure of the fuel injection control valve The electric stack elongates under the action of the inverse piezoelectric effect, pressing the hydraulic sleeve of the fuel injection control valve and the hydraulic core of the fuel injection control valve to move downward together, so that the oil chamber formed by the hydraulic sleeve of the fuel injection control valve and the valve stem of the fuel injection control valve As the oil pressure in the oil rises, the valve stem of the fuel injection control valve moves downward due to the pressure in the oil chamber, and then the umbrella-shaped piston is forced to move downward against the elastic force of the return spring of the fuel injection control valve. At this time, the cone surface at the lower end of the fuel injection control valve stem is sealed, so that the high-pressure oil circuit is cut off, and at the same time, the cone surface seal on the upper part of the umbrella-shaped piston is opened, and the control chamber passes through the cone surface channel on the upper part of the umbrella-shaped piston and the valve chamber of the fuel injection control valve. It is connected with the low-pressure oil drain hole, and the fuel in the control chamber flows back into the fuel tank through the low-pressure oil drain hole; the pressure in the upper chamber of the hydraulic compensation piston is greater than that formed by the pressure in the lower chamber of the hydraulic compensation piston and the spring force of the hydraulic compensation piston spring At this time, the hydraulic compensation piston moves downward, the check valve is closed, and the hydraulic compensation piston supplies oil to the control chamber through the oil outlet of the hydraulic compensation piston; when the resultant force of its pressure and the return spring of the needle valve is less than When the hydraulic pressure of the needle valve is high, the needle valve lifts up, and the injection hole injects fuel; when the fuel injection control valve is partially powered off, the valve stem of the fuel injection control valve is seated under the elastic force of the valve stem return spring of the fuel injection control valve, Open the high-pressure oil circuit while closing the low-pressure oil drain hole, open the check valve, and re-build the pressure in the control chamber through the oil inlet hole and the lower chamber of the hydraulic compensation piston. When the pressure in the control chamber and the elastic force of the needle valve spring form When the resulting force is greater than the upward hydraulic pressure of the fuel in the oil tank, the needle valve will seat again to stop fuel injection; when the boost control valve is partially powered off, the boost control valve stem acts on the spring force of the boost control valve stem spring. When the taper surface of the booster control valve stem is closed, the passage in the mushroom-shaped sleeve is opened, and the high-pressure fuel re-enters the first-stage booster chamber through the first-stage booster oil circuit. At this time, the pressure in the piston chamber If it is less than the sum of the pressure in the first-stage booster chamber, the second-stage booster chamber and the third-stage booster chamber and the elastic force of the piston return spring, the booster piston returns to the initial position upwards, the check valve opens again, and the fuel passes through the one-way The valve enters into the three-stage pressurized chamber and then into the oil tank.

3. When working in high boost mode, the boost control valve is energized, and the piezoelectric stack extends to the high boost position under the action of the inverse piezoelectric effect, pressing the hydraulic sleeve and the hydraulic core to move downward together, so that the hydraulic sleeve and the hydraulic core The oil pressure in the oil chamber formed by the valve stem of the boost control valve rises, and the valve stem of the boost control valve moves downward under the pressure in the oil chamber, and bacteria The sleeve will close the channel at the head of the booster control valve stem; at this time, the high-pressure oil circuit is no longer connected to the first-stage booster oil circuit, and the first-stage booster oil circuit passes through the cone surface of the booster control valve stem and the first-stage booster oil circuit. The oil return circuit is connected, and the fuel in the first-stage booster chamber flows through the first-stage pressurized oil circuit and returns to the low-pressure fuel tank; the stem of the boost control valve continues to move downward, driving the fungus sleeve Moving downward, the cone seal of the mushroom sleeve is opened, and the fuel in the secondary pressurized chamber is connected to the oil return circuit through the cone seal of the mushroom sleeve; at this time, the pressure in the piston chamber is greater than that of the first stage. The resultant force formed by the pressure in the booster chamber, the second-stage booster chamber, and the third-stage booster chamber and the elastic force of the booster piston return spring, the booster piston moves downward, and the single pressure at the oil inlet of the third-stage booster chamber The fuel injection control valve is partially energized, and the piezoelectric stack of the fuel injection control valve is extended under the action of the inverse piezoelectric effect, pressing the hydraulic sleeve of the fuel injection control valve and the hydraulic core of the fuel injection control valve to move downward together, so that the fuel injection control valve The oil pressure in the oil chamber formed by the hydraulic sleeve of the oil control valve and the valve stem of the fuel injection control valve rises, and the valve stem of the fuel injection control valve moves downward due to the pressure in the oil chamber, thereby pressing the umbrella-shaped piston to overcome the back pressure of the fuel injection control valve. The elastic force of the bit spring moves downward; at this time, the cone surface at the lower end of the fuel injection control valve stem is sealed, so that the high-pressure oil circuit is cut off, and at the same time, the cone surface seal on the upper part of the umbrella-shaped piston is opened, and the control chamber passes through the cone surface on the upper part of the umbrella-shaped piston. The channel and the valve chamber of the fuel injection control valve are connected with the low-pressure oil drain hole, and the fuel in the control chamber flows back into the fuel tank through the low-pressure oil drain hole; the pressure in the upper chamber of the hydraulic compensation piston is greater than the pressure in the lower chamber of the hydraulic compensation piston and the hydraulic The resultant force formed by the elastic force of the force compensation piston spring, at this time, the hydraulic compensation piston moves downward, the check valve is closed, and the hydraulic compensation piston supplies oil to the control chamber through the oil outlet of the hydraulic compensation piston; when the pressure in the control chamber and the needle valve reset When the resultant force of the spring is less than the hydraulic pressure of the fuel in the oil tank on the needle valve, the needle valve lifts up and the injection hole injects fuel; when the fuel injection control valve is partially powered off, the valve stem of the fuel injection control valve Under the action of the elastic force of the return spring, the seat is seated, and the high-pressure oil circuit is opened while the low-pressure oil drain hole is closed, the check valve is opened, and the pressure of the control chamber is re-established through the oil inlet hole and the lower chamber of the hydraulic compensation piston. When the resultant force formed by the pressure in the control chamber and the elastic force of the needle valve spring is greater than the upward hydraulic pressure of the fuel in the oil tank, the needle valve will seat again and stop fuel injection; when the boost control valve is partially powered off, the boost control valve stem will Under the combined force of the booster control valve stem spring and fungus sleeve spring, the fungus sleeve is driven to sit together, the upper cone surface of the fungus sleeve is closed, and the cone surface of the booster control valve stem is closed and opened at the same time In the passage in the middle of the mushroom sleeve, the high-pressure fuel re-enters the first-stage pressurized chamber and the second-stage pressurized chamber through the first-stage pressurized oil passage and the second-stage pressurized oil passage. At this time, the pressure in the piston chamber Less than the sum of the pressure in the first-stage booster chamber, the second-stage booster chamber and the third-stage booster chamber and the elastic force of the return spring of the booster piston, the booster piston returns to the initial position; the pressure in the third-stage booster chamber Lower, the check valve opens again, and the fuel enters the three-stage pressurized chamber through the check valve and then enters the oil tank.

4. The valve stem of the booster control valve and the mushroom-shaped sleeve form a triangular part, and the inner wall of the fungal sleeve is longer than the length of the triangular part.

The advantages of the present invention are as follows: 1. The accumulator piezoelectric fuel injector with variable fuel injection rules of the present invention adopts a three-stage stepped circular platform booster piston, and changes the boosting ratio by changing the pressure acting area, so that The fuel pressure in the oil tank can be adjusted according to the actual working conditions, which effectively improves the flexibility of fuel injection, enables the diesel engine to better meet the requirements of strict emission regulations, and effectively improves the economy and power of the diesel engine; 2 , The boost control valve adopted in the present invention can realize multi-stage positioning, realize the controllable on-off of multiple booster oil circuits, thereby adjust the high-pressure oil action area of the booster piston, and ensure the flexibility of the booster ratio of the electronically controlled injector 3. The present invention uses a piezoelectric driver to realize the different positioning of the boost control valve, which not only makes the positioning of the boost control valve more accurate and flexible, but also speeds up the adjustment speed of the boost ratio of the boost piston, so that The control accuracy of fuel injection law is further improved; 4. The pressure accumulator chamber can slow down the pressure fluctuation caused by fuel injection, which is beneficial to the precise control of fuel injection quantity, especially for the control accuracy of small fuel quantity can be significantly improved. At the same time, it is beneficial to reduce the material requirements of the common rail pipe and improve its service life. There is an orifice structure in the accumulator chamber, which can throttle and filter the fuel flowing from the accumulator chamber to the high-pressure oil pipe of the injector, thereby reducing the pressure fluctuation of the fuel in the injector and reducing the fluctuation of the cycle fuel injection quantity. Further and more accurately control the multiple injection process of the high-pressure common rail fuel system. The hydraulic compensation piston can supply oil to the control chamber during the process of oil return from the control chamber, slow down the oil pressure drop in the control chamber, and bypass the oil passage during the pressure build-up process of the control chamber to speed up Control the chamber pressure build-up speed, so that the injection law curve presents the law of slow first and then fast.

Description of drawings

Fig. 1 is a structural representation of the present invention;

Figure 2 is a schematic diagram of the partial structure of the pressure control valve;

Fig. 3 is a structural schematic diagram of a three-stage booster assembly;

Fig. 4 is a schematic diagram of the partial structure of the fuel injection control valve;

Fig. 5 is a schematic diagram of the structure of the needle valve part;

Fig. 6 is a schematic diagram of the structure of the hydraulic compensation piston.

Detailed ways

The present invention is described in more detail below in conjunction with accompanying drawing example:

1-6, the present invention is a pressure accumulator piezoelectric fuel injector with variable fuel injection rules, which consists of a fastening cap 1, a pressure accumulator chamber wall 2, a pressure boost control valve part 3, a three-stage piston assembly 4, The fuel injection control valve part 5, the needle valve part 6, the fuel injector body 8, the pressure accumulator chamber 9 and the filter orifice plate 10 are composed. The boost control valve part 3 is mainly composed of a piezoelectric stack 12, a gasket 13, a plate spring 14, a boost control valve stem 16, a fungus sleeve 18, a fungus sleeve limiting orifice 22, a fungus Shaped sleeve spring 24, boost control valve stem spring 25, boost control valve stem sleeve 26, hydraulic core 27 and hydraulic sleeve 28 form. There is a triangular fuel oil passage at the head of the booster control valve stem 16, and the fungus-shaped sleeve 18 is set on the head of the booster control valve stem 16, which cuts off and opens the fuel passage in the fungus-shaped sleeve through relative movement, and It communicates with the first-stage booster oil circuit 17 and the valve chamber 21 of the booster control valve. 21 communicates with the secondary boost oil circuit 19 and the boost orifice 23, and the mushroom-shaped sleeve 18 is located in the valve chamber 21 of the boost control valve. The three-stage piston assembly 4 mainly includes a booster piston 35, a piston return spring 32 and a one-way valve 34. The booster piston 35 has a three-stage stepped circular platform structure, and the booster piston 35 and the injector body 8 constitute a first-stage booster. Chamber 29, secondary pressurized chamber 30 and tertiary pressurized chamber 31, primary pressurized chamber 29 communicates with primary pressurized oil circuit 17, secondary pressurized chamber 30 communicates with secondary pressurized oil circuit 19 , The three-stage pressurized chamber 31 communicates with the oil tank 56 and communicates with the high-pressure oil circuit through the check valve 34 . The fuel injection control valve part 5 is composed of a fuel injection control valve piezoelectric stack 37, a fuel injection control valve gasket 38, a fuel injection control valve plate spring 39, a fuel injection control valve return spring 42, and a fuel injection control valve limiter. The orifice plate 46, the umbrella-shaped piston 47, the oil injection control valve hydraulic sleeve 50 and the oil injection control valve hydraulic core 49 are jointly formed. The needle valve part 6 includes a check valve 59 , a hydraulic compensation piston 60 , a hydraulic compensation piston spring 64 , a control chamber 51 , an oil tank 56 , a spray hole 55 , a needle valve 53 and a needle valve spring 52 . The hydraulic compensation piston part 58 is installed on the upper part of the needle valve part 6, and the needle valve limit orifice 57 is provided with a hydraulic compensation piston upper chamber 66, a hydraulic compensation piston lower chamber 65 and a hydraulic compensation piston oil drain chamber 63, The top of the hydraulic compensation piston upper chamber 66 communicates with the high-pressure oil circuit, the hydraulic compensation piston lower chamber 65 communicates with the hydraulic compensation piston oil inlet circuit 61 and the hydraulic compensation piston oil outlet circuit 62 respectively, and the hydraulic compensation piston oil inlet circuit 61 A check valve 59 is installed inside.

Figure 1 is a schematic diagram of the overall structure of the pressure accumulator piezoelectric fuel injector with variable fuel injection rules of the present invention, which mainly consists of a fastening cap 1, a pressure accumulator chamber wall 2, a boost control valve part 3, a three-stage piston assembly 4, The fuel injection control valve part 5, the needle valve part 6, the fuel injector body 8 and the filter orifice 10 are composed. The fastening cap 1 fastens and fastens the pressure boost control valve part 3 on the injector body 8 through the thread, and the nozzle tight cap 7 presses the fuel injection control valve part 5 and the needle valve part 6 together through the thread and fastens and fixes them On the fuel injector body 8 , the fastening cap 1 seals the accumulator chamber 9 through threads, and at the same time, the fastening cap 1 is processed with a fuel inlet 11 for introducing high-pressure oil into the accumulator chamber 9 .

Fig. 2 shows the boost control valve part 3 of the accumulator piezoelectric fuel injector with variable fuel injection rules. The boost control valve part 3 mainly includes a piezoelectric stack 12, a gasket 13, a plate spring 14, a boost Control valve stem 16, mushroom sleeve 18, mushroom sleeve limit orifice plate 22, mushroom sleeve spring 24, boost control valve stem spring 25, boost control valve stem sleeve 26, hydraulic core 27 and hydraulic sleeve 28. The piezoelectric stack 12 and the spacer 13 are stacked. The hydraulic core 27 is nested in the middle of the hydraulic sleeve 28, and the booster control valve stem 16 is also inserted into the hydraulic sleeve 28 to form a hydraulic oil cavity. The bottom end of the plate spring 14 is pressed above the valve stem sleeve 26 of the booster control valve, and the upper end of the plate spring 14 presses the hydraulic sleeve 28 tightly on the gasket 13, so that the hydraulic sleeve 28 and the hydraulic core 27 are aligned with the piezoelectric stack 12. Action by action. The booster control valve stem 16 passes through the booster control valve stem sleeve 26, the lower end of the booster control valve stem 16 is covered with a fungal sleeve 18, and the fungal sleeve 18 is located on the limit orifice 22 of the fungal sleeve. In the supercharging control valve chamber 21 surrounded by the booster piston limit orifice 20, the fungus sleeve 18 is lifted up under the action of the elastic force of the fungus sleeve spring 24, and the conical surface of the fungus sleeve 18 is in contact with the The fungus sleeve limiting orifice 22 forms a sealing surface. Between the fungus sleeve 18 and the boost control valve stem 16, a boost control valve stem spring 25 is placed. The spring force of the boost control valve stem spring 25 is smaller than that of the fungus sleeve spring 24. The valve stem 16 of the boost control valve is lifted upward under the applied force, and the tapered surface of the valve stem 16 of the boost control valve forms a sealing surface with the sleeve 26 of the valve stem of the boost control valve. The valve stem 16 of the booster control valve and the mushroom-shaped sleeve 18 are processed into a triangular shape. The length of the inner wall of the fungal sleeve 18 is longer than the length of the triangular part. In the initial state, the triangular part is not completely covered by the fungal sleeve. The cylinder 18 is airtight, and the fuel oil can be communicated up and down through the gap at the matching place. When the booster control valve stem 16 moves downward relative to the mushroom-shaped sleeve 18, the triangular part is completely sealed by the mushroom-shaped sleeve 18, and the fuel passage in the mushroom-shaped sleeve 18 is closed. A booster orifice 23 is processed in the limit orifice 22 of the mushroom sleeve. One end of the booster orifice 23 is connected to the high-pressure oil circuit, and the other end is connected to the valve chamber 21 of the booster control valve to introduce the high-pressure oil into the booster. Control valve chamber 21. A secondary boost oil circuit 19 is processed on the boost piston limiting orifice 20 , and the secondary boost oil circuit 19 communicates with the valve cavity 21 of the boost control valve. On the booster control valve stem sleeve 26 between the fungus sleeve 18 and the booster control valve stem 16, a first-stage booster oil circuit 17 is processed, and the first-stage booster oil channel 17 passes through the middle of the fungus-shaped sleeve 18 The passage is connected with the chamber 21 of the boost control valve. The booster control valve stem sleeve 26 on the top of the cone surface of the booster control valve stem 16 is processed with an oil return oil circuit 15, and the oil return oil circuit 15 communicates with the low pressure oil circuit.

The booster piston 35, the fuel injector body 8, the piston return spring 32 and the one-way valve 34 together constitute the three-stage piston assembly 4 of the accumulator piezoelectric fuel injector with variable fuel injection rules, as shown in Figure 3 . The booster piston 35 is a three-stage stepped cylinder structure, and forms a piston cavity 36 together with the booster piston limiting orifice 20 , and high-pressure oil passes into the piston cavity 36 through the hole opened on the piston limiting orifice 20 . The booster piston 35 and the fuel injector body 8 jointly constitute the first-stage booster chamber 29, the second-stage booster chamber 30 and the third-stage booster chamber 31, wherein the first-stage booster chamber 29 and the second-stage booster chamber 30 are respectively connected to The first-stage booster oil circuit 17 and the second-stage booster oil circuit 19 are connected, and the high-pressure oil in the valve cavity 21 of the booster control valve enters the first-stage booster oil circuit 17 and the second-stage booster oil circuit 19 respectively. Pressure chamber 29 and secondary pressurized chamber 30. The three-stage pressurized chamber 31 communicates with the high-pressure oil circuit through the one-way valve 34. A piston return spring 32 is placed in the three-stage pressurized chamber 31. At the same time, the lower part of the three-stage pressurized chamber 31 also has a pressurized oil passage 33. The pressurized oil passage 33 introduces the oil in the three-stage pressurized chamber 31 to the oil storage tank 56 .

Fuel injection control valve piezoelectric stack 37, fuel injection control valve gasket 38, fuel injection control valve plate spring 39, fuel injection control valve stem return spring 42, fuel injection control valve limit orifice plate 46, umbrella piston 47. The injection control valve hydraulic sleeve 50 and the injection control valve hydraulic core 49 together constitute the injection control valve part 5 of the accumulator piezoelectric injector with variable injection rules, as shown in FIG. 4 . The piezoelectric stack 37 of the fuel injection control valve and the gasket 38 of the fuel injection control valve are superimposed and placed, wherein the hydraulic core 49 of the fuel injection control valve is nested in the middle of the hydraulic sleeve 50 of the fuel injection control valve, and the valve stem 48 of the fuel injection control valve is also inserted into the fuel injection control valve. A hydraulic oil cavity is formed in the hydraulic sleeve 50 of the oil control valve. The bottom end of the fuel injection control valve plate spring 39 is pressed above the fuel injection control valve stem sleeve 40, and the upper end of the fuel injection control valve plate spring 39 presses the fuel injection control valve hydraulic sleeve 50 tightly against the fuel injection control valve gasket 38 On the other hand, the hydraulic sleeve 50 of the fuel injection control valve and the hydraulic core 49 of the fuel injection control valve are moved along with the action of the piezoelectric stack 37 of the fuel injection control valve. The fuel injection control valve stem 48 passes through the fuel injection control valve sleeve. The fuel injection control valve limiting orifice 46 and the middle orifice 44 jointly constitute the fuel injection control valve chamber 43, and the lower end of the fuel injection control valve stem 48 is pressed against the valve under the spring force of the fuel injection control valve return spring 42. On the umbrella piston 47. The umbrella piston 47 is located in the valve cavity 43 of the fuel injection control valve. In an initial state, the upper cone surface of the umbrella piston 47 forms a sealing surface with the valve stem sleeve 40 of the fuel injection control valve. When the valve stem 48 of the fuel injection control valve moves downward, its lower cone surface will form a sealing surface with the valve stem sleeve 40 of the fuel injection control valve, and the valve stem 48 of the fuel injection control valve will also drive the umbrella piston 47 to move downward, The sealing surface of the umbrella piston 47 is opened. The fuel injection control valve stem sleeve 40 on the lower conical surface of the fuel injection control valve stem 48 is processed with an oil circuit that communicates with the high-pressure oil circuit, and the fuel injection control valve stem sleeve 40 between the two sealing cone surfaces An oil inlet hole 45 is processed to communicate with the control cavity 51 . A low-pressure oil drain hole 41 is also processed in the limiting orifice plate 46 of the fuel injection control valve, one end communicates with the valve cavity 43 of the fuel injection control valve, and the other end communicates with the low-pressure fuel tank.

FIG. 5 is a structural diagram of the needle valve part 6 of the pressure accumulator piezoelectric fuel injector with variable injection rules, including a needle valve 53 , a needle valve spring 52 , a hydraulic compensation piston part 58 and a nozzle 54 . As shown in FIG. 6 , the hydraulic compensation piston part 58 includes a hydraulic compensation piston 60 and a hydraulic compensation piston spring 64 . The hydraulic compensation piston part 58 is located in the needle valve limit orifice 57, and forms a hydraulic compensation piston lower cavity 65 and a hydraulic compensation piston oil drain cavity 63 with the needle valve limit orifice 57, and forms a fluid pressure with the middle orifice 46 at the same time. The upper cavity 66 of the force compensation piston and the needle valve spring 52 are located in the lower cavity 65 of the hydraulic compensation piston. The upper chamber 66 of the hydraulic compensation piston communicates with the high-pressure oil circuit, while the lower chamber 65 of the hydraulic compensation piston communicates with the valve cavity 43 and The control chambers 51 communicate with each other, and a check valve 59 is arranged in the oil inlet passage 61 of the hydraulic compensation piston. The nozzle 54 and the needle valve limiting orifice 57 form a control chamber 51 and an oil tank 56 , and the needle valve spring 52 is located in the control chamber 51 . The lower end of the nozzle 54 is provided with a nozzle hole 55. When the resultant force formed by the elastic force of the needle valve spring 52 and the pressure in the control chamber 51 is greater than the pressure exerted by the oil tank 56 on the needle valve 53, the needle valve 53 is seated to close the nozzle hole 55; When the valve 53 was lifted, the spray hole 55 was communicated with the oil tank 56 to start spraying oil.

The fuel enters the accumulator chamber 9 from the fuel inlet 11, and a filter orifice 10 is arranged horizontally in the accumulator chamber 9. The accumulator chamber 9 is located at the top of the injector, and is respectively connected with the fuel inlet 11 and the lower high-pressure oil circuit. The high-pressure oil circuit leads a branch at the limit orifice 22 of the mushroom sleeve, enters the pressure boost control valve cavity 21 through the pressure boost orifice 23, and then divides into two circuits through the pressure boost control valve cavity 21 , one way enters the first-stage pressurized chamber 29 through the first-stage pressurized oil passage 17 , and the other enters the second-stage pressurized chamber 30 through the second-stage pressurized oil passage 19 . The fuel oil continues to draw a branch at the booster piston limiting orifice 20, and this branch leads to the piston chamber 36. The fuel continues to go down in the fuel injector body 8 and is divided into two paths: one path continues to go down through the high-pressure oil path in the limit orifice 46 of the fuel injection control valve and the lower cone of the valve stem 48 of the fuel injection control valve, and then passes through The oil inlet hole 45 enters the control chamber 51 ; the other enters into the three-stage pressurized chamber 31 through the check valve 34 , and then enters into the oil tank 56 through the pressurized oil passage 33 downwards. Now the hydraulic pressure in the piston chamber 36 is less than the resultant force formed by the hydraulic pressure in the first-stage pressurization chamber 29, the second-stage pressurization chamber 30 and the third-stage pressurization chamber 31 and the elastic force of the piston return spring 32, and the booster piston 35 It is in the highest position, so the fuel in the three-stage pressurization chamber 31 is not pressurized. Simultaneously, the resultant force formed by the pressure in the oil tank 56 and the needle valve spring 52 is greater than the pressure in the control chamber 51, and the needle valve 53 is seated at this time. According to the different fuel injection process, the fuel injector can be divided into three different working modes: no boost mode, low boost mode and high boost mode.

When the fuel injector works in the non-boost mode, the pressure boost control valve part 3 is not energized, and because the pressure on each acting surface of the three-stage piston is balanced at this time, the check valve 34 is opened, so the pressure in the three-stage boost chamber 31 The fuel pressure does not increase, and the fuel pressure in the oil tank 56 is equal to the pressure on the other side of the check valve 34 . When the fuel injection control valve part 5 is energized, the fuel injection control valve piezoelectric stack 37 elongates under the action of the inverse piezoelectric effect, driving the fuel injection control valve gasket 38 to press the fuel injection control valve hydraulic sleeve 50 and the fuel injection control valve The hydraulic core 49 moves downward together, so that the oil pressure in the oil chamber formed by the hydraulic sleeve 50 of the fuel injection control valve and the valve stem 48 of the fuel injection control valve rises, and the valve stem 48 of the fuel injection control valve is subjected to the pressure in the oil chamber to move downward. Movement, and then compress the umbrella piston 47 to overcome the elastic force of the fuel injection control valve return spring 42 to move downward. At this time, the conical surface of the lower end of the fuel injection control valve stem 48 is sealed, so that the high-pressure oil circuit is cut off, and at the same time, the conical surface seal on the upper part of the umbrella-shaped piston 47 is opened, and the control chamber 51 passes through the conical surface passage on the upper part of the umbrella-shaped piston 47 and the fuel injection valve. The control valve chamber 43 communicates with the low-pressure oil drain hole 41 , and the fuel in the control chamber 51 flows back into the fuel tank through the low-pressure oil drain hole 41 . Simultaneously, the pressure in the lower chamber 65 of the hydraulic compensation piston in the hydraulic compensation piston 60 decreases accordingly, and the pressure in the upper chamber 66 of the hydraulic compensation piston is greater than the resultant force formed by the pressure in the lower chamber 65 of the hydraulic compensation piston and the elastic force of the hydraulic compensation piston spring 64 At this time, the hydraulic compensation piston 60 moves downward, the check valve 59 is closed, and the hydraulic compensation piston 60 supplies oil to the control chamber 51 through the hydraulic compensation piston oil outlet 62, so that the pressure drop speed of the control chamber 51 is slowed down. When the resultant force formed by the pressure in the control chamber 51 and the spring force of the needle valve spring 52 is less than the upward hydraulic pressure of the fuel in the oil tank 56, the needle valve 53 lifts up, the nozzle hole 55 opens, and the injector starts to inject fuel. When the fuel injection control valve part 5 is powered off, the fuel injection control valve stem 48 is seated under the elastic force of the fuel injection control valve stem return spring 42, and the high pressure oil circuit is opened while the low pressure oil drain hole 41 is closed, The check valve 59 is opened, and the pressure of the control chamber 51 is rebuilt through the oil inlet hole 45 and the lower chamber 65 of the hydraulic compensation piston. During upward hydraulic pressure, the needle valve 53 takes a seat again, and the fuel injector stops injecting oil.

When the fuel injector works in the low boost mode, the boost control valve is energized, and the piezoelectric stack 12 is extended to the low pressure position under the action of the inverse piezoelectric effect, and the gasket 13 is driven to press the hydraulic sleeve 28 and the hydraulic core 27 together. Moving downward, the oil pressure in the oil chamber formed by the hydraulic sleeve 28 and the booster control valve stem 16 increases, and the booster control valve stem 16 moves downward by the pressure in the oil chamber, and the booster control valve When the tapered seal on the valve stem 16 is opened, the fungus sleeve 18 closes the passage at the head of the boost control valve stem 16 . At this time, the high-pressure oil circuit is no longer in communication with the first-stage booster oil circuit 17 , and the first-stage booster oil circuit 17 is in communication with the return oil circuit 15 through the tapered surface of the booster control valve stem 16 . The fuel in the primary boost chamber 29 returns to the low-pressure fuel tank through the primary boost oil circuit 17 and the return oil circuit 15. At this time, the pressure in the primary boost chamber 29 decreases, and the pressure in the piston chamber 36 is greater than The sum of the pressure in the primary boost chamber 29, the secondary boost chamber 30 and the pressure in the tertiary boost chamber 31 and the elastic force of the piston return spring 32, the boost piston 35 moves downward, and the intake of the tertiary boost chamber 31 The one-way valve 34 at the oil port is closed, and the fuel pressure in the three-stage pressurized chamber 31 is pressurized to increase, thereby causing the fuel pressure in the oil tank 56 to increase. Then the fuel injection control valve 3 is partially energized, and the piezoelectric stack 37 of the fuel injection control valve elongates under the action of the inverse piezoelectric effect, driving the fuel injection control valve gasket 38 to press the fuel injection control valve hydraulic sleeve 50 and the fuel injection control valve hydraulic valve. The core 49 moves downward together, so that the oil pressure in the oil chamber formed by the oil injection control valve hydraulic sleeve 50 and the oil injection control valve stem 48 rises, and the oil injection control valve stem 48 moves downward due to the pressure in the oil chamber , and then the umbrella piston 47 is forced to move downward against the elastic force of the return spring 42 of the fuel injection control valve. At this time, the conical surface of the lower end of the fuel injection control valve stem 48 is sealed, so that the high-pressure oil circuit is cut off, and at the same time, the conical surface seal on the upper part of the umbrella-shaped piston 47 is opened, and the control chamber 51 passes through the conical surface passage on the upper part of the umbrella-shaped piston 47 and the fuel injection valve. The control valve chamber 43 communicates with the low-pressure oil drain hole 41 , and the fuel in the control chamber 51 flows back into the fuel tank through the low-pressure oil drain hole 41 . At this time, the pressure in the control chamber 51 decreases, and the pressure in the lower chamber 65 of the hydraulic compensation piston in the hydraulic compensation piston 60 decreases accordingly, and the pressure in the upper chamber 66 of the hydraulic compensation piston is greater than the pressure in the lower chamber 65 of the hydraulic compensation piston. The resultant force formed by the elastic force of the force compensation piston spring 64, at this time the hydraulic compensation piston 60 moves downward, the check valve 59 is closed, and the hydraulic compensation piston 60 supplies oil to the control chamber 51 through the hydraulic compensation piston oil outlet 62, so that The pressure drop rate of the control chamber 51 slows down. When the resultant force of its pressure and the needle valve return spring 51 is less than the hydraulic pressure of the fuel in the oil tank 56 to the needle valve 53, the needle valve 53 lifts up, the nozzle hole 55 is opened, and the injector starts to spray oil. When the fuel injection control valve part 5 is powered off, the fuel injection control valve stem 48 is seated under the elastic force of the fuel injection control valve stem return spring 42, and the high pressure oil circuit is opened while the low pressure oil drain hole 41 is closed, The check valve 59 is opened, and the pressure of the control chamber 51 is rebuilt through the oil inlet hole 45 and the lower chamber 65 of the hydraulic compensation piston. During upward hydraulic pressure, the needle valve 53 takes a seat again, and the fuel injector stops injecting oil. When the boost control valve part 3 is powered off, the boost control valve stem 16 is seated again under the spring force of the boost control valve stem spring 25, and opens while the boost control valve stem 16 cone is closed. The passage in the mushroom sleeve 18, the high-pressure fuel re-enters the first-stage pressurized chamber 29 through the first-stage pressurized oil circuit 17, and the pressure in the piston chamber 36 is lower than that of the first-stage pressurized chamber 29 and the second-stage pressurized chamber 30. And the sum of the pressure in the three-stage boost chamber 31 and the elastic force of the piston return spring 32, the boost piston 35 returns to the initial position upwards. The pressure in the three-stage pressurized chamber 31 decreases, and the check valve 34 is opened again, and the fuel enters the three-stage pressurized chamber 31 through the check valve 34 and then enters the fuel tank 56 .

When the injector works in the high boost mode, the boost control valve is energized, and the piezoelectric stack 12 is extended to the high boost position under the action of the inverse piezoelectric effect, driving the gasket to press the hydraulic sleeve 28 and the hydraulic core 27 Together, they move downward to increase the oil pressure in the oil chamber formed by the hydraulic sleeve 28 and the boost control valve stem 16, and the boost control valve stem 16 is moved downward by the pressure in the oil chamber, and the boost control When the tapered seal on the valve stem 16 is opened, the fungus sleeve 18 closes the passage at the head of the boost control valve stem 16 . At this time, the high-pressure oil circuit is no longer connected with the first-stage booster oil circuit 17, and the first-stage booster oil circuit 17 is connected with the return oil circuit 15 through the taper surface of the booster control valve stem 16, and the first-stage booster chamber The fuel pressure in 29 drops. The fuel in the primary pressurized chamber 29 flows through the primary pressurized oil circuit 17 and returns to the low-pressure fuel tank through the oil return circuit 15 . Subsequently, the booster control valve stem 16 continues to move downward, driving the fungus sleeve 18 to move downward, so that the tapered surface of the fungus sleeve 18 is sealed and opened, and the fuel in the secondary booster chamber 30 passes through the fungus sleeve 18 The cone seal of the taper is in communication with the oil return oil passage 15, and the pressure in the secondary pressurized chamber 30 also drops. Now the pressure in the piston chamber 36 is greater than the resultant force formed by the pressure in the first-stage booster chamber 29, the second-stage booster chamber 30 and the third-stage booster chamber 31 and the elastic force of the booster piston return spring 32, and the booster piston 35 Moving downward, the check valve 34 at the oil inlet of the three-stage pressurized chamber 31 is closed, and the fuel pressure in the three-stage pressurized chamber 31 increases, which in turn causes the fuel pressure in the oil tank 56 to increase. Then the fuel injection control valve part 5 is energized, and the fuel injection control valve piezoelectric stack 37 elongates under the action of the inverse piezoelectric effect, driving the fuel injection control valve gasket 38 to press the fuel injection control valve hydraulic sleeve 50 and the fuel injection control valve hydraulic pressure. The core 49 moves downward together, so that the oil pressure in the oil chamber formed by the oil injection control valve hydraulic sleeve 50 and the oil injection control valve stem 48 rises, and the oil injection control valve stem 48 moves downward due to the pressure in the oil chamber , and then the umbrella piston 47 is forced to move downward against the elastic force of the return spring 42 of the fuel injection control valve. At this time, the conical surface of the lower end of the fuel injection control valve stem 48 is sealed, so that the high-pressure oil circuit is cut off, and at the same time, the conical surface seal on the upper part of the umbrella piston 47 is opened, and the control chamber passes through the conical surface channel on the upper part of the umbrella piston 47 and the fuel injection control valve. The valve chamber 43 communicates with the low-pressure oil drain hole 41, and the fuel in the control chamber flows back into the fuel tank through the low-pressure oil drain hole 41. Simultaneously, the pressure in the lower chamber 65 of the hydraulic compensation piston in the hydraulic compensation piston 60 decreases accordingly, and the pressure in the upper chamber 66 of the hydraulic compensation piston is greater than the resultant force formed by the pressure in the lower chamber 65 of the hydraulic compensation piston and the elastic force of the hydraulic compensation piston spring 64 At this time, the hydraulic compensation piston 60 moves downward, the check valve 59 is closed, and the hydraulic compensation piston 60 supplies oil to the control chamber 51 through the hydraulic compensation piston oil outlet 62, so that the pressure drop speed of the control chamber 51 is slowed down. At this time, the pressure in the control chamber 51 drops, and when the resultant force of the pressure and the needle valve return spring 51 is less than the hydraulic pressure of the fuel in the oil tank 56 on the needle valve 53, the needle valve 53 is lifted upwards, the nozzle hole 55 is opened, and the oil is injected. The injector starts to spray oil. When the fuel injection control valve part 5 is powered off, the fuel injection control valve stem 48 is seated under the elastic force of the fuel injection control valve stem return spring 42, and the high pressure oil circuit is opened while the low pressure oil drain hole 41 is closed, The check valve 59 is opened, and the pressure of the control chamber 51 is re-established through the oil inlet hole 45 and the lower chamber 65 of the hydraulic compensation piston. When the hydraulic pressure of the fuel oil in the 56 was upward, the needle valve 53 took a seat again, and the fuel injector stopped injecting oil. When the boost control valve part 3 is powered off, the boost control valve stem 16 drives the fungus sleeve 18 to sit together under the combined force of the boost control valve stem spring 25 and the fungus sleeve spring 24. The upper cone surface of the mushroom-shaped sleeve 18 is closed, and then the passage in the middle of the mushroom-shaped sleeve 18 is opened while closing the cone surface of the booster control valve stem 16, and the high-pressure fuel passes through the first-stage booster oil circuit 17 and the second-stage booster The oil passage 19 re-enters the primary boost chamber 29 and the secondary boost chamber 30, and now the pressure in the piston chamber 36 is less than that in the primary boost chamber 29, the secondary boost chamber 30 and the tertiary boost chamber 31. The sum of the pressure and the elastic force of the supercharging piston return spring 32, the supercharging piston 35 returns to the initial position upwards. The pressure in the three-stage pressurized chamber 31 decreases, and the check valve 34 is opened again, and the fuel enters the three-stage pressurized chamber 31 through the check valve 34 and then enters the fuel tank 56 .

From the working process of the accumulator piezoelectric fuel injector with variable fuel injection rules, it can be known that the present invention can achieve different boost ratios to achieve different fuel injection pressures by changing the action response of the boost control valve during the working process. , so that the injector can achieve more flexible fuel injection characteristics. At the same time, the present invention adopts a piezoelectric fuel injection control valve, which further improves the response speed and control precision of the fuel injector on the basis of electromagnetic drive, so that the present invention can realize more accurate multiple injections. Effectively improve the power and fuel economy of the diesel engine. The present invention uses a piezoelectric driver to realize the different positioning of the boost control valve, which not only makes the positioning of the boost control valve more accurate and flexible, but also speeds up the adjustment speed of the boost ratio of the boost piston, so that the regular injection The control precision is further improved. . The pressure accumulator chamber can effectively slow down the pressure fluctuation caused by fuel injection, which is beneficial to the precise control of the fuel injection quantity, especially for the control accuracy of small fuel quantity can be significantly improved. At the same time, when the injector is used in the common rail fuel system, the pressure stabilization effect of the accumulator can reduce the size of the common rail pipe of the diesel engine, which is conducive to reducing the material requirements of the common rail pipe and improving its service life. At the same time, there is an orifice structure in the accumulator chamber, and throttle holes with different diameters are drilled on the orifice plate, which can throttle and filter the fuel flowing from the accumulator chamber to the high-pressure oil pipe of the injector, thereby reducing the fuel injection. The pressure fluctuation of the fuel in the oil tank reduces the fluctuation of the cycle fuel injection quantity, and further more accurately controls the multiple injection process of the high-pressure common rail fuel system. The adopted hydraulic compensation piston structure replenishes oil when the control chamber releases pressure, and plays the role of two-way oil inlet when the pressure is built up, so that the oil injection pattern can be slow first and then urgent, and the oil injection performance can be improved.

Claims (9)

1. the variable pressure accumulation type piezoelectric fuel injector of fuel injection characteristic, it is characterized in that: including oil injector body, pressure accumulation cavity wall, pressurization control Valve portion, three-level piston component, Injection Control valve portion, needle-valve portion, pressure accumulation cavity wall are fixed on above oil injector body, pressurization control Valve portion processed and three-level piston component are mounted in oil injector body from top to bottom, and Injection Control valve portion and needle-valve portion pass through it The external tight cap of nozzle is mounted below three-level piston component, and pressure accumulation chamber is opened up in pressure accumulation cavity wall, and pressure accumulation chamber is connected to high-pressure oil passage；

The pressurization control valve portion includes piezoelectric pile, supercharger control valve valve rod, bacterium shape sleeve, hydraulic core, supercharger control valve valve Rod sleeve, piezoelectric pile sleeve, bacterium shape sleeve limit orifice plate, charged piston limit orifice plate, piezoelectric pile sleeve, bacterium shape sleeve limit hole Plate and charged piston limit orifice plate are arranged from top to bottom, and hydraulic core is mounted in hydraulic sleeve, piezoelectric pile, hydraulic sleeve, pressurization control Valve stem sleeve is arranged in from top to bottom in piezoelectric pile sleeve, and supercharger control valve valve rod is installed in supercharger control valve stem sleeve, The upper end of supercharger control valve valve rod stretches in hydraulic sleeve and is formed between hydraulic core hydraulic fluid chamber, and bacterium shape sleeve limits orifice plate In be arranged supercharger control valve valve chamber, bacterium shape sleeve be arranged in supercharger control valve valve chamber, the lower end of supercharger control valve valve rod is protruded into In bacterium shape sleeve, the exterior panel shape spring of hydraulic sleeve, the bottom end of plate-shaped springs is pressed in above supercharger control valve stem sleeve, The upper end of plate-shaped springs is pressed in the upper end of hydraulic sleeve, and the middle part setting supercharger control valve valve rod protrusion of supercharger control valve valve rod increases Supercharger control valve valve rod spring, the conical surface lower end of bacterium shape sleeve and pressurization are set between pressure control valve valve rod protrusion and bacterium shape sleeve Setting is set with sleeve spring between piston limit orifice plate, and oil return circuit and level-one pressurised oil is arranged on supercharger control valve stem sleeve Road, bacterium shape sleeve limit setting pressurization throttle orifice on orifice plate, and charged piston, which limits, is arranged two-stage supercharging oil circuit on orifice plate, level-one increases Pressure oil road is connected to supercharger control valve valve chamber by the access among bacterium shape sleeve, and oil return circuit is connected to low pressure oil way, pressurization throttling Hole is respectively communicated with high-pressure oil passage and supercharger control valve valve chamber, two-stage supercharging oil communication supercharger control valve valve chamber；

The three-level piston component includes charged piston, piston return spring, and charged piston is three-level stepped cylinder structure, from upper And lower is respectively the first-third cylinder, and diameter successively decreases, the first cylinder and the charged piston above it are limited and are formed between orifice plate Plunger shaft, plunger shaft limit the hole in orifice plate by charged piston and are connected to high-pressure oil passage, the first cylinder and the second cylinder and oil spout Level-one booster cavity is formed between body, and two-stage supercharging chamber, third column are formed between the second cylinder and third cylinder and oil injector body Three-level booster cavity is formed between body and oil injector body below, and piston return spring, level-one pressurization are installed in three-level booster cavity Chamber is connected to level-one Pressure Increasing Oil-Line, and two-stage supercharging chamber is connected to two-stage supercharging oil circuit, and three-level booster cavity is connected to high pressure oil by check valve Road, three-level booster cavity lower part are provided with Pressure Increasing Oil-Line；

The Injection Control valve portion includes injector control valve piezoelectric pile, injector control valve hydraulic sleeve, injector control valve valve stem sleeve Cylinder, injector control valve valve rod, injector control valve limit orifice plate, umbrella shape piston, intermediate orifice plate, injector control valve piezoelectric pile, oil spout Control valve hydraulic sleeve and injector control valve stem sleeve are arranged in oil injector body from top to bottom, set in injector control valve hydraulic sleeve The hydraulic core of injector control valve is set, injector control valve valve rod is mounted in injector control valve stem sleeve, injector control valve valve rod Upper end stretch in injector control valve hydraulic sleeve and with hydraulic fluid chamber, oil injector body and injector control valve limit hole are formed between it Plate, intermediate orifice plate form injector control valve valve chamber, and umbrella shape piston is mounted in injector control valve valve chamber, under injector control valve valve rod Side pressure installs injector control valve return spring, oil spout between the conical surface lower end of umbrella shape piston and intermediate orifice plate on umbrella shape piston The external of control valve hydraulic sleeve installs injector control valve plate-shaped springs, and the bottom end of injector control valve plate-shaped springs is pressed in Injection Control Above valve stem sleeve, the upper end of injector control valve plate-shaped springs is pressed in the upper end of injector control valve hydraulic sleeve, injector control valve The oil circuit being connected to high-pressure oil passage and oil inlet metering-orifice are offered on stem sleeve, and low pressure is set on injector control valve limit orifice plate Oil leak hole, low pressure oil leak hole are respectively communicated with low pressure oil way and injector control valve valve chamber；

The needle-valve portion includes needle-valve limit orifice plate, needle-valve block, needle-valve limit orifice plate and during needle-valve block is arranged in from top to bottom Between below orifice plate, fluid power compensating piston epicoele in-line, non-return passage are set in intermediate orifice plate, non-return is installed in non-return passage Valve, fluid power compensating piston epicoele in-line are connected to high-pressure oil passage, and non-return passage is connected to oil inlet metering-orifice, sets in needle-valve limit hole Fluid power compensating piston, control chamber oil circuit are set, fluid power compensating piston reset spring is cased with outside fluid power compensating piston, fluid power compensation is lived The upper end of plug reset spring is withstood on fluid power compensating piston, and the lower end of fluid power compensating piston reset spring withstands on needle-valve below It limits on orifice plate, is formed on the fluid power compensating piston communicated with fluid power compensating piston epicoele in-line above fluid power compensating piston Chamber, fluid power compensating piston reset spring present position are fluid power compensating piston cavity of resorption, fluid power compensating piston lower end with below Needle-valve, which limits, forms fluid power compensating piston draining chamber, control chamber oil communication oil inlet metering-orifice between orifice plate；Needle is installed in needle-valve block Valve, needle-valve top are cased with needle-valve reset spring, and the upper end of needle-valve reset spring is withstood on needle-valve limit orifice plate, needle-valve reset spring Lower end withstand on needle-valve, needle-valve reset spring present position is control chamber, and control chamber is connected to control chamber oil circuit, is set in needle-valve block Oil holding slot in-line is set, forms oil holding slot between needle-valve and needle-valve block, spray orifice, oil holding slot in-line difference is arranged in needle-valve block bottom It is connected to oil holding slot and Pressure Increasing Oil-Line, fluid power compensating piston cavity of resorption is connected to below check-valves by fluid power compensating piston cavity of resorption in-line Non-return passage, fluid power compensating piston cavity of resorption by fluid power compensating piston vent line be connected to control chamber.

2. the variable pressure accumulation type piezoelectric fuel injector of fuel injection characteristic according to claim 1, it is characterized in that: without under boost mode When work, when injector control valve partial current, injector control valve piezoelectric pile oppresses injector control valve hydraulic sleeve and Injection Control The hydraulic core of valve moves downward jointly, the oil pressure liter in oil pocket for forming injector control valve hydraulic sleeve and injector control valve valve rod Height, injector control valve valve rod is moved downward by pressure effect in oil pocket, and then is oppressed umbrella shape piston overpowers injector control valve and returned The elastic force of position spring moves downward, and the conical surface of injector control valve valve rod lower end is closed at this time, is cut off high-pressure oil passage, while umbrella The conical surface seal of shape upper piston area is opened, control chamber by the conical surface channel of umbrella shape upper piston area and injector control valve valve chamber with it is low Pressure oil leak hole is connected, and the fuel oil in control chamber is flow back into fuel tank by low pressure oil leak hole；Liquid in fluid power compensating piston simultaneously The pressure of force compensating piston cavity of resorption decreases, the pressure of fluid power compensating piston epicoele be greater than under fluid power compensating piston cavity pressure with The resultant force that the elastic force of fluid power compensating piston spring is formed, fluid power compensating piston moves downward at this time, closure of check ring, fluid power compensation Piston slows down control cavity pressure decrease speed by the fuel-displaced road direction control chamber repairing of fluid power compensating piston；When in control chamber When the resultant force that the elastic force of pressure and needle valve spring is formed is less than the upward hydraulic coupling of fuel oil in oil holding slot, needle-valve is lifted up, spray Hole commencement of fuel injection；When the power-off of Injection Control valve portion, bullet of the injector control valve valve rod in injector control valve valve rod return spring It takes a seat under power effect, high-pressure oil passage is opened while by low pressure draining bore closure, check-valves is opened, and control chamber passes through oil inlet quantity Hole and fluid power compensating piston cavity of resorption build pressure again, contain when the resultant force that the elastic force of pressure and needle valve spring in control chamber is formed is greater than In oil groove when the upward hydraulic coupling of fuel oil, needle-valve drops back into one's seat, and stops oil spout.

3. the variable pressure accumulation type piezoelectric fuel injector of fuel injection characteristic according to claim 1 or 2, it is characterized in that: low pressure charging mould When working under formula, supercharger control valve is powered, and piezoelectric pile is elongated to locations of low pressure under the action of inverse piezoelectric effect, oppresses hydraulic sleeve It is moved downward jointly with hydraulic core, the oil pressure in oil pocket for forming hydraulic sleeve and supercharger control valve valve rod increases, pressurization control Valve valve rod is moved downward by the pressure in oil pocket, bacterium shape set while opening the conical surface seal on supercharger control valve valve rod Cylinder closes the channel on supercharger control valve valve rod head, and high-pressure oil passage is no longer connected to level-one Pressure Increasing Oil-Line at this time, while level-one Pressure Increasing Oil-Line is connected by the conical surface of supercharger control valve valve rod with oil return circuit.Fuel oil in level-one booster cavity is increased by level-one Pressure oil road flows through oil return circuit and returns in low-pressure reservoir, and the pressure in plunger shaft is greater than level-one booster cavity, two-stage supercharging chamber at this time With the sum of the elastic force of pressure and piston return spring in three-level booster cavity, charged piston is moved downward, three-level booster cavity into The closed check valve of oil port；Injector control valve partial current, injector control valve piezoelectric pile are stretched under the action of inverse piezoelectric effect It is long, it oppresses injector control valve hydraulic sleeve and the hydraulic core of injector control valve moves downward jointly, make injector control valve hydraulic sleeve and spray The oil pressure in oil pocket that oil control valve valve rod is formed increases, and injector control valve valve rod is moved downward by pressure effect in oil pocket, And then the elastic force for oppressing umbrella shape piston overpowers injector control valve return spring moves downward.Injector control valve valve rod lower end at this time The conical surface is closed, is cut off high-pressure oil passage, while the conical surface seal of umbrella shape upper piston area is opened, and control chamber passes through on umbrella shape piston The conical surface channel in portion and injector control valve valve chamber are connected with low pressure oil leak hole, and the fuel oil in control chamber passes through low pressure oil leak hole stream It returns in fuel tank；The pressure of fluid power compensating piston epicoele is greater than cavity pressure and fluid power compensating piston spring under fluid power compensating piston The resultant force that elastic force is formed, fluid power compensating piston moves downward at this time, closure of check ring, and fluid power compensating piston is compensated by fluid power and lived Fill in fuel-displaced road direction control chamber repairing；When the resultant force of its pressure and needle-valve reset spring is less than in oil holding slot fuel oil to the hydraulic of needle-valve When power, needle-valve is lifted up, spray orifice oil spout；When the power-off of Injection Control valve portion, injector control valve valve rod is in injector control valve It takes a seat under the elastic force effect of valve rod return spring, high-pressure oil passage is opened while by low pressure draining bore closure, check-valves is opened, Control chamber builds pressure by oil inlet metering-orifice and fluid power compensating piston cavity of resorption again, when the elastic force of pressure and needle valve spring in control chamber When the resultant force of formation is greater than the upward hydraulic coupling of fuel oil in oil holding slot, needle-valve drops back into one's seat, and stops oil spout；When pressurization control valve portion When disjunction electricity, supercharger control valve valve rod drops back into one's seat under the spring-force driven dual of supercharger control valve valve rod spring, will be pressurized control The access in bacterium shape sleeve is opened while the valve valve rod conical surface processed is closed, high pressure fuel reenters one by level-one Pressure Increasing Oil-Line Grade booster cavity, the pressure in plunger shaft is less than level-one booster cavity, two-stage supercharging chamber and pressure and work in three-level booster cavity at this time Fill in the sum of the elastic force of return spring, charged piston is again turned on back up into initial position, check valve, fuel oil by check valve into Enter and enters back into oil holding slot into three-level booster cavity.

4. the variable pressure accumulation type piezoelectric fuel injector of fuel injection characteristic according to claim 1 or 2, it is characterized in that: high pressure-charging mould When working under formula, supercharger control valve is powered, and piezoelectric pile is elongated to high pressure-charging position under the action of inverse piezoelectric effect, oppresses hydraulic Set and hydraulic core move downward jointly, and the oil pressure in oil pocket for forming hydraulic sleeve and supercharger control valve valve rod increases, pressurization control Valve valve rod processed is moved downward by the pressure in oil pocket, bacterium shape while opening the conical surface seal on supercharger control valve valve rod Sleeve closes the channel on supercharger control valve valve rod head；High-pressure oil passage is no longer connected to level-one Pressure Increasing Oil-Line at this time, while one Grade Pressure Increasing Oil-Line is connected by the conical surface of supercharger control valve valve rod with oil return circuit, and the fuel oil in level-one booster cavity passes through level-one Pressure Increasing Oil-Line flows through oil return circuit and returns in low-pressure reservoir；Supercharger control valve valve rod continues to move downward, drive bacterium shape sleeve to Lower movement opens the conical surface seal of bacterium shape sleeve, and the intracavitary fuel oil of two-stage supercharging passes through the conical surface seal of bacterium shape sleeve and returns Oil circuit is connected；The pressure in plunger shaft is greater than the pressure in level-one booster cavity, two-stage supercharging chamber and three-level booster cavity at this time The resultant force formed with the elastic force of charged piston return spring, charged piston move downward, the list at the oil inlet of three-level booster cavity It is closed to valve；Injector control valve partial current, injector control valve piezoelectric pile extend under the action of inverse piezoelectric effect, oppress oil spout Control valve hydraulic sleeve and the hydraulic core of injector control valve move downward jointly, make injector control valve hydraulic sleeve and injector control valve valve rod Oil pressure in the oil pocket of formation increases, and injector control valve valve rod is moved downward by pressure effect in oil pocket, and then oppresses umbrella shape The elastic force of piston overpowers injector control valve return spring moves downward；The conical surface of injector control valve valve rod lower end is closed at this time, makes High-pressure oil passage is cut off, while the conical surface seal of umbrella shape upper piston area is opened, and control chamber is logical by the conical surface of umbrella shape upper piston area Road and injector control valve valve chamber are connected with low pressure oil leak hole, and the fuel oil in control chamber flow back into fuel tank by low pressure oil leak hole It is interior；The elastic force that the pressure of fluid power compensating piston epicoele is greater than cavity pressure and fluid power compensating piston spring under fluid power compensating piston is formed Resultant force, fluid power compensating piston moves downward at this time, closure of check ring, fluid power compensating piston pass through fluid power compensating piston vent line To control chamber repairing；When the resultant force of control cavity pressure and needle-valve reset spring is less than in oil holding slot fuel oil to the hydraulic coupling of needle-valve When, needle-valve is lifted up, spray orifice oil spout；When the power-off of Injection Control valve portion, injector control valve valve rod is in injector control valve valve It takes a seat under the elastic force effect of bar return spring, high-pressure oil passage is opened while by low pressure draining bore closure, check-valves is opened, control Chamber processed builds the newly-built pressure of ballast by oil inlet metering-orifice and fluid power compensating piston cavity of resorption again, when the pressure and needle valve spring in control chamber The resultant force that is formed of elastic force when being greater than the upward hydraulic coupling of fuel oil in oil holding slot, needle-valve drops back into one's seat, and stops oil spout；When pressurization is controlled When valve portion processed powers off, supercharger control valve valve rod band under the force action of supercharger control valve valve rod spring and bacterium shape sleeve spring Dynamic bacterium shape sleeve is taken a seat together, and the upper conical surface of bacterium shape sleeve is closed, and is opened while the supercharger control valve valve rod conical surface is closed Access among bacterium shape sleeve, high pressure fuel by level-one Pressure Increasing Oil-Line and two-stage supercharging oil circuit reenter level-one booster cavity and Two-stage supercharging chamber, at this time the pressure in plunger shaft be less than level-one booster cavity, two-stage supercharging chamber and three-level booster cavity in pressure with The sum of the elastic force of charged piston return spring, charged piston is back up into initial position；Pressure reduction in three-level booster cavity, it is single It is again turned on to valve, fuel oil is entered in three-level booster cavity by check valve and enters back into oil holding slot.

5. the variable pressure accumulation type piezoelectric fuel injector of fuel injection characteristic according to claim 3, it is characterized in that: under high pressure-charging mode When work, supercharger control valve is powered, and piezoelectric pile is elongated to high pressure-charging position under the action of inverse piezoelectric effect, compressing hydraulic sleeve and Hydraulic core moves downward jointly, and the oil pressure in oil pocket for forming hydraulic sleeve and supercharger control valve valve rod increases, supercharger control valve Valve rod is moved downward by the pressure in oil pocket, bacterium shape sleeve while opening the conical surface seal on supercharger control valve valve rod The channel on supercharger control valve valve rod head is closed；High-pressure oil passage is no longer connected to level-one Pressure Increasing Oil-Line at this time, while level-one increases Pressure oil road is connected by the conical surface of supercharger control valve valve rod with oil return circuit, and the fuel oil in level-one booster cavity is pressurized by level-one Oil circuit flows through oil return circuit and returns in low-pressure reservoir；Supercharger control valve valve rod continues to move downward, and bacterium shape sleeve is driven to transport downwards It is dynamic, open the conical surface seal of bacterium shape sleeve, the intracavitary fuel oil of two-stage supercharging passes through the conical surface seal of bacterium shape sleeve and oil return oil Road is connected；The pressure in plunger shaft is greater than level-one booster cavity, two-stage supercharging chamber and pressure and increasing in three-level booster cavity at this time The resultant force for pressing the elastic force of piston return spring to be formed, charged piston move downward, the check valve at the oil inlet of three-level booster cavity It closes；Injector control valve partial current, injector control valve piezoelectric pile extend under the action of inverse piezoelectric effect, oppress Injection Control Valve hydraulic sleeve and the hydraulic core of injector control valve move downward jointly, form injector control valve hydraulic sleeve and injector control valve valve rod Oil pocket in oil pressure increase, injector control valve valve rod by oil pocket pressure effect move downward, and then oppress umbrella shape piston The elastic force of injector control valve return spring is overcome to move downward；The conical surface of injector control valve valve rod lower end is closed at this time, makes high pressure Oil circuit is cut off, while the conical surface seal of umbrella shape upper piston area is opened, control chamber by the conical surface channel of umbrella shape upper piston area and Injector control valve valve chamber is connected with low pressure oil leak hole, and the fuel oil in control chamber is flow back into fuel tank by low pressure oil leak hole；Liquid The pressure of force compensating piston upper chamber is greater than the conjunction that the elastic force of cavity pressure and fluid power compensating piston spring is formed under fluid power compensating piston Power, fluid power compensating piston moves downward at this time, closure of check ring, and fluid power compensating piston passes through the fuel-displaced road direction control of fluid power compensating piston Chamber repairing processed；When the resultant force for controlling cavity pressure and needle-valve reset spring is less than the hydraulic coupling of fuel oil in oil holding slot to needle-valve, needle Valve is lifted up, spray orifice oil spout；When the power-off of Injection Control valve portion, injector control valve valve rod is in injector control valve valve rod return It takes a seat under the elastic force effect of spring, high-pressure oil passage is opened while by low pressure draining bore closure, check-valves is opened, and control chamber is logical It crosses oil inlet metering-orifice and fluid power compensating piston cavity of resorption builds the newly-built pressure of ballast again, when the elastic force of pressure and needle valve spring in control chamber When the resultant force of formation is greater than the upward hydraulic coupling of fuel oil in oil holding slot, needle-valve drops back into one's seat, and stops oil spout；When pressurization control valve portion When disjunction electricity, supercharger control valve valve rod drives bacterium shape under the force action of supercharger control valve valve rod spring and bacterium shape sleeve spring Sleeve is taken a seat together, and the upper conical surface of bacterium shape sleeve is closed, and bacterium shape set is opened while the supercharger control valve valve rod conical surface is closed The intermediate access of cylinder, high pressure fuel reenters level-one booster cavity by level-one Pressure Increasing Oil-Line and two-stage supercharging oil circuit and second level increases Chamber is pressed, the pressure in plunger shaft is less than pressure and pressurization work in level-one booster cavity, two-stage supercharging chamber and three-level booster cavity at this time The sum of the elastic force of return spring is filled in, charged piston is back up into initial position；Pressure reduction in three-level booster cavity, check valve is again Secondary opening, fuel oil are entered in three-level booster cavity by check valve and enter back into oil holding slot.

6. the variable pressure accumulation type piezoelectric fuel injector of fuel injection characteristic according to claim 1 or 2, it is characterized in that: pressurization control At three rib type parts at valve valve rod and the sleeve cooperation of bacterium shape, bacterium shape sleeve lining length is longer than three rib type partial-lengths.

7. the variable pressure accumulation type piezoelectric fuel injector of fuel injection characteristic according to claim 3, it is characterized in that: supercharger control valve valve At three rib type parts at bar and the sleeve cooperation of bacterium shape, bacterium shape sleeve lining length is longer than three rib type partial-lengths.

8. the variable pressure accumulation type piezoelectric fuel injector of fuel injection characteristic according to claim 4, it is characterized in that: supercharger control valve valve At three rib type parts at bar and the sleeve cooperation of bacterium shape, bacterium shape sleeve lining length is longer than three rib type partial-lengths.

9. the variable pressure accumulation type piezoelectric fuel injector of fuel injection characteristic according to claim 5, it is characterized in that: supercharger control valve valve At three rib type parts at bar and the sleeve cooperation of bacterium shape, bacterium shape sleeve lining length is longer than three rib type partial-lengths.