Pressure accumulation type fuel injection system

Abstract

The utility model discloses a pressure accumulation type fuel injection system which is characterized in that a pressure accumulation volume is arranged in an oil injector, and a high-pressure common rail pipe is omitted; by adopting the flow metering device which is closed when the oil inlet valve is powered off, the driving current is reduced; the high-pressure oil pump is driven by an eccentric cam, a plunger reset spring is cancelled, and a forced descending device is additionally arranged; a one-way valve is arranged on a low-pressure oil way of the high-pressure oil pump, fuel oil is sucked from the outside through the downward stroke of a plunger, and an external oil delivery pump is replaced And the electronic controller is integrated on the high-pressure oil pump. The structure of the pressure accumulation type fuel injection system is greatly simplified, higher pumping efficiency, smaller high-pressure oil pump size and lower noise can be achieved, and particularly lower system comprehensive cost is achieved.

Description

TECHNICAL FIELD

[0001] The present application relates to an engine fuel injection system, in particular a pressure accumulation type fuel injection system. BACKGROUND

[0002] The fuel injection system on an engine is a system device responsible for pressurizing fuel and injecting high pressure fuel into the combustion chamber. The fuel injection system at least includes a high pressure pump responsible for pressurization, an injector responsible for injecting fuel into the combustion chamber, and in an electronically controlled fuel injection system, a separate electronic controller. To ensure stable and sufficient oil supply to the high pressure pump, an additional oil pump is usually provided before the high pressure pump.

[0003] In a pressure accumulation type electronically controlled fuel injection system, the prior art also includes a high pressure common rail pipe with a hollow pressure accumulation volume, which provides pressure stabilization and high pressure fuel distribution to the injectors. The high pressure outlet of the high pressure pump is connected to the inlet of the high pressure common rail pipe through a high pressure oil pipe, and the outlet of the pressure accumulation volume is connected to the inlet of the injector through a high pressure oil pipe. The high pressure connection structure between multiple injectors on the same engine is in parallel relationship. This pressure accumulation type electronically controlled fuel injection system with a high pressure common rail pipe is commonly referred to as a high pressure common rail fuel injection system.

[0004] The flow metering device on the high pressure pump controls the flow of high pressure fuel and the pressure accumulation pressure, and there are currently three types.

[0005] 1. High pressure relief type. This flow metering device is installed after the outlet valve and relieves excess high pressure. This control method has extremely low pumping efficiency, high cost, and insufficient reliability, and has been eliminated.

[0006] 2. Inlet throttling type. This flow metering device is installed before the inlet valve and uses a proportional electromagnetic valve to adjust the throttle area of the fuel passage to control the size of the fuel flow into the high pressure pump plunger, thereby controlling the high pressure accumulation pressure. This form is currently the mainstream, but its pressure control response speed is slow, the inlet throttling has efficiency loss and cavitation risk, and the proportional valve cost is high.

[0007] 3. The oil inlet valve is closed by power. The flow metering device is installed on the oil inlet valve, and the armature core is arranged between the electromagnetic valve coil and the oil inlet valve one-way sealing line. In normal state, the armature core is pushed open by the spring force, so that the oil inlet valve is kept open, and the fuel is returned to the low-pressure oil circuit from the oil inlet valve when the oil pump plunger goes up, and no high-pressure fuel is generated outward. When the electromagnetic valve is powered on, the armature core is separated from the oil inlet valve, so that the oil inlet valve is closed under the double action of the internal and external pressure difference and the oil inlet valve spring, and the fuel is pressurized to output to the high-pressure oil circuit through the oil outlet valve. By adjusting the closing time of the oil inlet valve, the control of the high-pressure fuel output flow size and pressure is realized. This form has high pumping efficiency, but the electromagnetic valve needs a large driving force to close, the electromagnetic valve is large in size, and the electronic controller needs to provide a large driving current, and the system has high comprehensive cost.

[0008] The stroke of the plunger of the high-pressure oil pump in the oil suction process is realized by the reset spring. Because the plunger runs at a high speed and has a very short downward time, the reset spring is large in size and is subjected to harsh force, which leads to large working noise and is not conducive to the miniaturization of the high-pressure oil pump, and the cost of the high-pressure oil pump is high.

[0009] In summary, the existing technology of the pressure accumulation type electronically controlled fuel injection system with a high-pressure common rail pipe has the disadvantages of complex structure, low pumping efficiency, large size, large noise, and high cost. SUMMARY

[0010] The purpose of the present application is to provide a pressure accumulation type fuel injection system, which includes the following innovative points.

[0011] A pressure accumulation volume is arranged in the fuel injector, and the pressure accumulation volumes of multiple fuel injectors on the same engine are in series with each other. A pressure accumulation pressure sensor and a pressure accumulation pressure limiting valve are installed on the high-pressure oil pump, and the high-pressure common rail pipe is cancelled;

[0012] The high-pressure oil pump adopts a flow metering device of the oil inlet valve power-off closing type, and the driving current is reduced;

[0013] The high-pressure oil pump is driven by an eccentric cam, the plunger reset spring is cancelled, and a forced downward reset device is additionally arranged, so that the structure of the oil pump is simplified, and the limit speed of the oil pump can be improved;

[0014] A one-way valve is arranged on the low-pressure oil circuit of the high-pressure oil pump, and the fuel is sucked from the outside during the downward stroke of the plunger, so that the external fuel pump is replaced;

[0015] The electronic controller is integrated on the high-pressure oil pump, and the assembly and wiring harness arrangement of the engine are simpler and more convenient.

[0016] In combination with the above part or all of the innovative points, the structure is simpler, higher efficiency, smaller size, lower noise, and lower cost can be realized.

[0017] To achieve the above object, the present application adopts the following technical solutions.

[0018] The present application provides a pressure-accumulating fuel injection system, which comprises a high-pressure fuel pump, an injector, a high-pressure fuel pipe and an electronic controller.

[0019] The high-pressure fuel pump comprises a pump body, a camshaft, a plunger and a high-pressure module. The plunger is arranged in a compression chamber of the high-pressure module and can reciprocate along the axial direction of the plunger. An oil inlet valve and an oil outlet valve are arranged adjacent to the top of the compression chamber. The oil inlet valve, under the action of an oil inlet spring, keeps the fuel flowing from an external low-pressure fuel chamber to the compression chamber in a one-way manner. The oil outlet valve, under the action of an oil outlet spring, keeps the fuel flowing from the compression chamber to an external high-pressure oil outlet in a one-way manner.

[0020] The injector is provided with a pressure-accumulating volume and a first high-pressure joint and a second high-pressure joint which are in communication with the pressure-accumulating volume. The pressure-accumulating volumes of the multiple injectors on the same engine are in series with each other. Specifically, the first high-pressure joint of the first injector is in communication with the high-pressure oil outlet of the high-pressure fuel pump through the high-pressure fuel pipe, the second high-pressure joint is in communication with the first high-pressure joint of the adjacent another injector through the high-pressure fuel pipe, and so on until the first high-pressure joint of the last injector. That is, the pressure-accumulating volumes in each injector are in series with each other through the high-pressure fuel pipe to provide stable pressure for the system.

[0021] Preferably, the high-pressure fuel pump is further provided with a second high-pressure oil outlet. The second high-pressure joint of the last injector is in communication with the second high-pressure oil outlet of the high-pressure fuel pump through the high-pressure fuel pipe or is closed by a high-pressure plug.

[0022] Preferably, the high-pressure fuel pump is provided with a pressure-accumulating pressure sensor and a pressure-limiting valve on the high-pressure fuel circuit. The output signal of the pressure-accumulating pressure sensor is connected to the electronic controller through a wire harness.

[0023] Preferably, the top of the oil inlet valve of the high-pressure fuel pump is provided with a flow metering electromagnetic valve and an armature plate. There is a small magnetic gap between the flow metering electromagnetic valve and the armature plate. The coil of the flow metering electromagnetic valve is arranged between the one-way sealing line of the oil inlet valve and the armature plate. When the flow metering electromagnetic valve is powered on, the electromagnetic force generated thereby attracts the armature plate, which presses the stem of the oil inlet valve, so that the oil inlet valve always keeps open. When the plunger goes up, the fuel in the compression chamber flows back to the external low-pressure fuel chamber from the oil inlet valve, and high-pressure fuel is not generated. When the flow metering electromagnetic valve is powered off, the electromagnetic force disappears, and the oil inlet valve restores the one-way flow trend.

[0024] The control time of the flow metering solenoid valve is controlled to realize the control of the output flow size and pressure of the high-pressure fuel. The flow metering solenoid valve only needs a small electromagnetic force, and the size can be small, and the electronic controller only needs to provide a small driving current, which is beneficial to reduce the comprehensive cost of the system.

[0025] Preferably, a cylindrical eccentric wheel is arranged on the camshaft, an eccentric ring rotatable around the shaft is sleeved on the eccentric wheel, and a reset block is arranged on the eccentric ring; the reciprocating sliding direction of the plunger is perpendicular to the axial direction of the eccentric ring; a push-pull foot is arranged at the bottom of the plunger and is transversely and slidably arranged in a parallel sliding groove between the eccentric ring and the reset block; the eccentric ring abuts against the bottom of the push-pull foot to push the plunger upward, and the reset block abuts against the back of the push-pull foot to pull the plunger downward; under the limitation of the eccentric ring and the reset block, the plunger reciprocates with the rotation of the eccentric wheel.

[0026] It can be seen that the downward reset of the plunger is forced, and the plunger reset spring is not needed. Therefore, the high-pressure oil pump has smaller size, wider speed adaptability and reliability.

[0027] Preferably, the high-pressure oil pump is provided with a first one-way valve and a second one-way valve; the inlet of the first one-way valve is communicated with the oil inlet of the high-pressure oil pump, the outlet is communicated with the low-pressure fuel chamber outside the oil inlet valve, and the tendency of one-way flow of fuel from the oil inlet to the low-pressure fuel chamber outside the oil inlet valve is maintained; the inlet of the second one-way valve is communicated with the low-pressure fuel chamber outside the oil inlet valve, and the outlet is communicated with the transition oil passage in the pump body, and the tendency of one-way flow of fuel from the low-pressure fuel chamber outside the oil inlet valve to the transition oil passage is maintained. The transition oil passage is communicated with the relief valve and finally communicated with the oil return port of the high-pressure oil pump. Under this low-pressure oil path structure, the fuel is inhaled from the outside during the downward stroke of the plunger, replacing the external fuel pump, and further reducing the comprehensive cost of the system.

[0028] Preferably, the electronic controller is integrated on the high-pressure oil pump, and the electronic controller is provided with an electrical interface and is electrically connected with the flow metering solenoid valve, the pressure accumulation pressure sensor, the fuel injector and other sensors and actuators on the high-pressure oil pump to realize accurate control of the pressure and injection of the pressure accumulation type fuel injection system. It can be seen that the electronic controller is closer to the fuel metering device and the control line of the fuel injector, and the assembly and wiring harness arrangement on the engine are simpler and more convenient.

[0029] The beneficial effects of the present application are as follows:

[0030] By setting up the pressure accumulation volume in the fuel injector, the high-pressure common rail pipe is cancelled; by using the flow metering device of the oil inlet valve de-energized closing type, the driving current is reduced; the high-pressure oil pump driving uses the eccentric cam, the plunger reset spring is cancelled, the forced down device is additionally arranged, the oil pump structure is simplified, and the limit rotating speed of the oil pump can be improved; the one-way valve is arranged on the low-pressure oil way of the high-pressure oil pump, the external fuel is inhaled from the outside during the plunger down stroke, and the external fuel pump is replaced; the electronic controller is integrated on the high-pressure oil pump, and the engine assembly is simplified. In combination with the above partial or all innovation points, the structure of the pressure accumulation type fuel injection system is greatly simplified, higher pumping efficiency, smaller high-pressure oil pump size, lower noise, and especially lower system comprehensive cost can be realized. BRIEF DESCRIPTION OF DRAWINGS

[0031] Figure 1 is a structure schematic diagram of a pressure accumulation type fuel injection system of the present application.

[0032] Figure 2 is a structure schematic diagram of an embodiment of the high-pressure oil pump of the present application.

[0033] Figure 3 is a local three-dimensional schematic diagram of the eccentric cam-reset block-plunger structure of the high-pressure oil pump of the present application.

[0034] Figure 4 is a local schematic diagram of the oil suction process of the plunger of the high-pressure oil pump of the present application.

[0035] Figure 5 is a local schematic diagram of the oil discharge process of the plunger of the high-pressure oil pump of the present application.

[0036] Figure 6 is a local schematic diagram of the high-pressure oil delivery process of the plunger of the high-pressure oil pump of the present application.

[0037] In the figure: 100-high-pressure oil pump; 200-fuel injector; 300-high-pressure oil pipe; 400-electronic controller; 11-pump body; 12-camshaft; 12a-eccentric wheel; 13-plunger; 13a-pushing and pulling leg; 13b-leg bottom; 13c-leg back; 14-high-pressure module; 14a-oil inlet spring; 14b-oil inlet valve; 14c-low-pressure fuel chamber; 14d-compression chamber; 14e-oil outlet valve; 14f-oil outlet spring; 14g-high-pressure oil outlet; 14g'-second high-pressure oil outlet; 15-pressure accumulation pressure sensor; 16-pressure accumulation pressure limiting valve; 17-flow metering electromagnetic valve; 18-armature sheet; 19-eccentric ring; 20-reset block; 21-first one-way valve; 22-second one-way valve; 23-transition oil way; 24-oil inlet; 25-pressure relief valve; 26-oil return; 210-pressure accumulation volume; 220-first high-pressure joint; 230-second high-pressure joint. DETAILED DESCRIPTION

[0038] The application will be further described below in conjunction with the drawings and embodiments. It should be understood that the specific embodiments described herein are intended to be merely illustrative of the application and not in limitation thereof. It should also be noted that, for the purpose of clarity, only those structures related to the application are shown in the drawings.

[0039] In the description of the application, unless otherwise explicitly specified and limited, the terms "connected", "connected", "fixed" should be understood broadly, for example, it can be fixedly connected, or it can be detachably connected, or it can be integrated; it can be mechanically connected, or it can be electrically connected; it can be directly connected, or it can be indirectly connected through an intermediate medium; it can be the internal communication of two elements or the interaction relationship between two elements. For those skilled in the art, the specific meaning of the above terms in the application can be understood according to the specific circumstances.

[0040] In the present application, unless otherwise explicitly specified and limited, the "upper" or "lower" of the first feature to the second feature can include that the first and second features are in direct contact, or that the first and second features are not in direct contact but are in contact through another feature between them. Moreover, the "upper", "above" and "on" of the first feature to the second feature includes that the first feature is directly above and obliquely above the second feature, or only indicates that the horizontal height of the first feature is higher than that of the second feature. The "below", "under" and "under" of the first feature to the second feature includes that the first feature is directly below and obliquely below the second feature, or only indicates that the horizontal height of the first feature is less than that of the second feature.

[0041] In the description of the present embodiment, the terms "upper", "lower", "left", "right" and the like orientation or position relationship are based on the orientation or position relationship shown in the drawings, and are only for the convenience of description and simplification of operation, and do not indicate or imply that the device or element referred to must have a particular orientation, be constructed and operated in a particular orientation, and therefore cannot be understood as a limitation on the application. In addition, the terms "first" and "second" are only used to distinguish in the description and have no special meaning. Embodiment

[0042] As Figures 1-6 shown in the embodiment, a pressure-accumulating fuel injection system includes a high-pressure oil pump 100, an injector 200, a high-pressure oil pipe 300, and an electronic controller 400.

[0043] The high-pressure oil pump 100 comprises a pump body 11, a camshaft 12, a plunger 13 and a high-pressure module 14. The plunger 13 is arranged in a compression chamber 14d of the high-pressure module 14 and can reciprocate axially along the plunger 13, and an oil inlet valve 14b and an oil outlet valve 14e are arranged adjacent to the top of the compression chamber 14d: the oil inlet valve 14b keeps the fuel in a one-way flow from an oil inlet valve 14b external low-pressure fuel chamber 14c to the compression chamber 14d under the action of an oil inlet spring 14a; the oil outlet valve 14e keeps the fuel in a one-way flow from the compression chamber 14d to the external high-pressure oil outlet 14g under the action of an oil outlet spring 14f.

[0044] As shown in Figure 1 The injection device 200 is provided with a pressure accumulation volume 210, and a first high-pressure connector 220 and a second high-pressure connector 230 which respectively communicate with the pressure accumulation volume 210. In this embodiment, a 4-cylinder engine is provided with 4 injection devices 200, and the high-pressure communication structure between the pressure accumulation volumes 210 of the injection devices 200 is in series, specifically: the first high-pressure connector 220 of the first injection device 200 communicates with the high-pressure oil outlet 14g of the high-pressure oil pump 100 through the high-pressure oil pipe 300, the second high-pressure connector 230 communicates with the first high-pressure connector 220 of the adjacent another injection device 200 through the high-pressure oil pipe 300, and so on until the first high-pressure connector 220 of the last injection device 200, that is, the pressure accumulation volumes 210 in each injection device 200 are connected in series through the high-pressure oil pipe 300, and collectively provide stable pressure for the system.

[0045] In this embodiment, the high-pressure oil pump 100 is also provided with a second high-pressure oil outlet 14g'. The second high-pressure connector 230 of the last injection device 200 is connected to the second high-pressure oil outlet 14g' of the high-pressure oil pump 100 through the high-pressure oil pipe 300.

[0046] When the high-pressure oil pump 100 has only one plunger 13 and only one high-pressure oil outlet 14g, the second high-pressure connector 230 of the last injection device 200 is closed by a high-pressure plug. The structure of the high-pressure plug is a conventional technology, which is simple and easy to understand, and is omitted here.

[0047] The high-pressure oil circuit of the high-pressure oil pump 100 is provided with a pressure accumulation pressure sensor 15 and a pressure accumulation pressure limiting valve 16, and the output signal of the pressure accumulation pressure sensor 15 is connected to the electronic controller 400 through a wire harness. In the prior art, the pressure accumulation pressure sensor 15 and the pressure accumulation pressure limiting valve 16 are arranged on the high-pressure common rail pipe, and this embodiment provides a solution to cancel the high-pressure common rail pipe and install the pressure accumulation pressure sensor 15 and the pressure accumulation pressure limiting valve 16 on the high-pressure oil pump 100.

[0048] The flow metering solenoid valve 17 and the armature plate 18 are arranged on the top of the high-pressure oil pump 100 inlet valve 14b, and there is a small magnetic gap between the flow metering solenoid valve 17 and the armature plate 18. The flow metering solenoid valve 17 coil is arranged between the one-way sealing line of the inlet valve 14b and the armature plate 18. When the flow metering solenoid valve 17 is energized, the electromagnetic force generated attracts the armature plate 18, which presses the rod of the inlet valve 14b, so that the inlet valve 14b always tends to be open. When the plunger 13 goes up, the fuel in the compression chamber 14d flows back to the low-pressure fuel chamber 14c from the inlet valve 14b, and high-pressure fuel is not generated. When the flow metering solenoid valve 17 is de-energized, the electromagnetic force disappears, and the inlet valve 14b tends to be one-way flow.

[0049] By controlling the de-energization time of the flow metering solenoid valve 17, the output flow size and pressure of the high-pressure fuel are controlled. When the flow metering solenoid valve 17 is energized, the inlet valve 14b is in an open state, and the armature plate 18 is already in the position closest to the flow metering solenoid valve 17, i.e., the smallest magnetic gap. When the inlet valve 14b is closed, the action of the armature plate 18 does not need to be driven by the flow metering solenoid valve 17, so the flow metering solenoid valve 17 only needs a very small electromagnetic force, and the size can be made smaller. The electronic controller 400 only needs to provide a very small driving current, which is conducive to reducing the overall cost of the system. The flow metering device of this type of inlet valve de-energization closing type has high pumping efficiency and low overall system cost.

[0050] As shown in Figures 2-3 The camshaft 12 is provided with a cylindrical eccentric wheel 12a, the eccentric ring 19 is sleeved on the eccentric wheel 12a and can rotate around the shaft, and the reset block 20 is arranged on the eccentric ring 19. The reciprocating sliding direction of the plunger 13 is perpendicular to the axial direction of the eccentric ring 19. The plunger 13 is provided with a push-pull foot 13a at the bottom, the push-pull foot 13a is transversely and slidably arranged in the parallel sliding groove between the eccentric ring 19 and the reset block 20, the eccentric ring 19 abuts against the foot bottom 13b of the push-pull foot 13a to push the plunger 13 upward, and the reset block 20 abuts against the foot back 13c of the push-pull foot 13a to pull the plunger 13 downward. The plunger 13 is limited by the eccentric ring 19 and the reset block 20 and reciprocates with the rotation of the eccentric wheel 12a.

[0051] It can be seen that the downward reset of the plunger 13 is forced and does not need a reset spring. Therefore, the high-pressure oil pump 100 has smaller size, wider speed adaptability and reliability.

[0052] As shown in Figure 2As shown, the high-pressure oil pump 100 is provided with a first one-way valve 21 and a second one-way valve 22. The inlet of the first one-way valve 21 is connected to the oil inlet 24 of the high-pressure oil pump 100, and the outlet is connected to the low-pressure fuel chamber 14c outside the oil inlet valve 14b, so as to keep the fuel flowing from the oil inlet 24 to the low-pressure fuel chamber 14c outside the oil inlet valve 14b in a single direction. The inlet of the second one-way valve 22 is connected to the low-pressure fuel chamber 14c outside the oil inlet valve 14b, and the outlet is connected to the transition oil passage 23 in the pump body 11, so as to keep the fuel flowing from the low-pressure fuel chamber 14c outside the oil inlet valve 14b to the transition oil passage 23 in a single direction. The transition oil passage 23 leads to the relief valve 25 and finally to the oil return port 26 of the high-pressure oil pump 100. In this low-pressure oil passage structure, the fuel is inhaled from the outside during the downward stroke of the plunger 13, replacing the external fuel pump, and further reducing the overall cost of the system.

[0053] Figures 4-6 The process of oil suction, oil discharge and high-pressure oil delivery of the plunger 13 of the high-pressure oil pump 100 is specifically shown.

[0054] When the plunger 13 is descending, the oil inlet valve 14b is opened under the action of the internal and external pressure difference, and the fuel is inhaled from the oil inlet 24 through the first one-way valve 21, the low-pressure fuel chamber 14c and the oil inlet valve 14b into the compression chamber 14d. At this time, the armature plate 18 is pulled close to the flow metering electromagnetic valve 17 under the action of the oil inlet valve 14b.

[0055] When the plunger 13 is close to the bottom dead center, the flow metering electromagnetic valve 17 is energized to generate an electromagnetic force to attract the armature plate 18, so that the oil inlet valve 14b remains in an open state. At this time, when the plunger 13 is ascending, the fuel in the compression chamber 14d is discharged in reverse through the oil inlet valve 14b, the low-pressure fuel chamber 14c and the second one-way valve 22 into the transition oil passage 23.

[0056] When the plunger 13 ascends to a certain position, the flow metering electromagnetic valve 17 is de-energized, the armature plate 18 loses the electromagnetic attraction force, and the oil inlet valve 14b is closed under the combined action of the internal and external pressure difference and the oil inlet spring 14a. As the plunger 13 continues to ascend, high pressure is generated in the compression chamber 14d, the fuel rushes out of the oil outlet valve 14e, and high-pressure fuel is delivered to the high-pressure oil outlet 14g.

[0057] It can be seen that by controlling the de-energization time of the flow metering electromagnetic valve 17, the fuel inhaled in the compression chamber 14d can be controlled, and the proportion of the fuel flowing out of the oil inlet valve 14b and the oil outlet valve 14e can be controlled, so as to realize the control of the size and pressure of the high-pressure fuel flow.

[0058] As Figure 1As shown, the electronic controller 400 is integrated on the high-pressure oil pump 100. Without being specifically shown in the figure, it can be made according to conventional technology that the electronic controller 400 is provided with electrical interfaces electrically connected with the flow metering valve 17, the accumulator pressure sensor 15, the injector 200 and other sensors and actuators on the high-pressure oil pump 100, so as to realize accurate control of the pressure and injection amount of the accumulator type fuel injection system. It can be seen that the electronic controller 400 is closer to the control lines of the flow metering valve 17 and the injector 200, and the assembly and wiring harness arrangement on the engine are simpler and more convenient.

[0059] Obviously, the above embodiments of the present application are only examples for clearly illustrating the present application, and are not intended to limit the embodiments of the present application. Various obvious changes, re-adjustments and substitutions can be made by those skilled in the art without departing from the scope of the present application. It is unnecessary and impossible to enumerate all the embodiments. Any modification, equivalent substitution and improvement within the spirit and principle of the present application shall be included in the protection scope of the claims of the present application.

Claims

1. A pressure-accumulating fuel injection system comprising a high-pressure fuel pump (100), a fuel injector (200), a high-pressure fuel pipe (300) and an electronic controller (400), characterized in that: the high-pressure fuel pump (100) comprises a pump body (11), a camshaft (12), a plunger (13) and a high-pressure module (14); the plunger (13) is arranged in a compression chamber (14d) of the high-pressure module (14) and can reciprocate along the plunger (13) in an axial direction, an oil inlet valve (14b) and an oil outlet valve (14e) are arranged adjacent to the top of the compression chamber (14d); the oil inlet valve (14b) is under the action of an oil inlet spring (14a) to keep the fuel flowing from an external low-pressure fuel chamber (14c) of the oil inlet valve (14b) to the compression chamber (14d) in a one-way direction; the oil outlet valve (14e) is under the action of an oil outlet spring (14f) to keep the fuel flowing from the compression chamber (14d) to an external high-pressure oil outlet (14g) in a one-way direction; the fuel injector (200) is provided with an accumulator volume (210) and a first high-pressure connector (220) and a second high-pressure connector (230) which are in communication with the accumulator volume (210), respectively; the accumulator volumes (210) of multiple fuel injectors (200) on the same engine are in series with each other in terms of high-pressure communication structure, specifically: the first high-pressure connector (220) of the first fuel injector (200) is in communication with the high-pressure oil outlet (14g) of the high-pressure fuel pump (100) through the high-pressure fuel pipe (300), the second high-pressure connector (230) is in communication with the first high-pressure connector (220) of the adjacent another fuel injector (200) through the high-pressure fuel pipe (300), and so on until the first high-pressure connector (220) of the last fuel injector (200) is communicated, that is: the accumulator volumes (210) in each fuel injector (200) are communicated in series through the high-pressure fuel pipe (300).

2. The pressure-accumulating fuel injection system according to claim 1, characterized in that: the high-pressure fuel pump (100) is further provided with a second high-pressure oil outlet (14g’); the second high-pressure connector (230) of the last fuel injector (200) is communicated to the second high-pressure oil outlet (14g’) of the high-pressure fuel pump (100) through the high-pressure fuel pipe (300), or is closed by a high-pressure plug.

3. The pressure-accumulating fuel injection system according to claim 1, characterized by: The high-pressure fuel pump (100) is provided with an accumulator pressure sensor (15) and an accumulator pressure limiting valve (16) on the high-pressure fuel circuit, and the output signal of the accumulator pressure sensor (15) is connected to the electronic controller (400) through a wire harness.

4. The pressure-accumulating fuel injection system according to claim 1, characterized by: The high-pressure oil pump (100) is provided with a flow metering electromagnetic valve (17) and an armature plate (18) on the top of the oil inlet valve (14b), and there is a small magnetic gap between the flow metering electromagnetic valve (17) and the armature plate (18). The coil of the flow metering electromagnetic valve (17) is arranged between the one-way sealing line of the oil inlet valve (14b) and the armature plate (18). When the flow metering electromagnetic valve (17) is energized, the electromagnetic force generated thereby attracts the armature plate (18), which presses the rod part of the oil inlet valve (14b), so that the oil inlet valve (14b) always tends to be opened. When the plunger (13) goes up, the fuel in the compression chamber (14d) flows back to the low-pressure fuel chamber (14c) from the oil inlet valve (14b) and cannot generate high-pressure fuel. When the flow metering electromagnetic valve (17) is de-energized, the electromagnetic force disappears, and the oil inlet valve (14b) tends to resume one-way flow.

5. The pressure-accumulating fuel injection system according to claim 1, characterized by: The camshaft (12) is provided with a cylindrical eccentric wheel (12a), the eccentric wheel (12a) is sleeved with an eccentric ring (19) which can rotate around the shaft, and the eccentric ring (19) is provided with a reset pressing block (20). The reciprocating sliding direction of the plunger (13) is perpendicular to the axial direction of the eccentric ring (19). The bottom of the plunger (13) is provided with a push-pull foot (13a) which is transversely and slidably arranged in the parallel sliding groove between the eccentric ring (19) and the reset pressing block (20). The eccentric ring (19) abuts against the foot bottom (13b) of the push-pull foot (13a) to push the plunger (13) to go up, and the reset pressing block (20) abuts against the foot back (13c) of the push-pull foot (13a) to pull the plunger (13) to go down. Under the limitation of the eccentric ring (19) and the reset pressing block (20), the plunger (13) reciprocates with the rotation of the eccentric wheel (12a).

6. The pressure-accumulating fuel injection system according to claim 1, characterized by: The high-pressure oil pump (100) is provided with a first one-way valve (21) and a second one-way valve (22). The inlet of the first one-way valve (21) is connected to the oil inlet (24) of the high-pressure oil pump (100), and the outlet is connected to the low-pressure fuel chamber (14c) outside the oil inlet valve (14b), so as to keep the fuel flowing in one direction from the oil inlet (24) to the low-pressure fuel chamber (14c) outside the oil inlet valve (14b). The inlet of the second one-way valve (22) is connected to the low-pressure fuel chamber (14c) outside the oil inlet valve (14b), and the outlet is connected to the transition oil passage (23) in the pump body (11), so as to keep the fuel flowing in one direction from the low-pressure fuel chamber (14c) outside the oil inlet valve (14b) to the transition oil passage (23). The transition oil passage (23) leads to the pressure relief valve (25) and finally to the oil return port (26) of the high-pressure oil pump (100).

7. The pressure-accumulating fuel injection system according to claim 1, characterized by: The electronic controller (400) is integrated on the high-pressure oil pump (100), and the electronic controller (400) is provided with an electrical interface.

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