CN115288898B

CN115288898B - Fuel injector

Info

Publication number: CN115288898B
Application number: CN202210855910.2A
Authority: CN
Inventors: 李永志; 尧命发; 梁和平; 钱立宏; 李波; 黎金辉; 郑尊清; 刘海峰; 王浒
Original assignee: Tianjin University
Current assignee: Tianjin University
Priority date: 2022-07-20
Filing date: 2022-07-20
Publication date: 2023-06-16
Anticipated expiration: 2042-07-20
Also published as: CN115288898A

Abstract

The invention discloses a fuel injector, comprising: a first channel suitable for conveying the first fuel and a second channel suitable for conveying the second fuel are arranged in the side wall of the shell; a valve body, comprising: the base is arranged in the connecting shell, and a third channel and a fourth channel which are respectively communicated with the first channel and the second channel are formed in the side wall of the base; and an extension portion extending from the housing, the end of the extension portion being provided with a plurality of first ejection openings and a plurality of second ejection openings communicating with the third passage and the fourth passage, respectively; a shutoff member movably disposed within the valve body and configured to move between a first position in which the first injection port and the second injection port are simultaneously closed, and a second position in which the first injection port and the second injection port are simultaneously opened; and an actuating assembly disposed within the housing and adapted to drive the stop member between the first position and the second position. By moving the shut-off member to simultaneously close and open the first injection port and the second injection port, the fuel injector can be made simple in structure and low in energy consumption, and fuel injection control accuracy can be improved while two kinds of fuel injection are realized.

Description

Fuel injector

Technical Field

The invention relates to the technical field of engines, in particular to a direct injection dual-channel fuel injector suitable for an engine.

Background

Currently, finding fuels for internal combustion engines that replace petroleum such as alcohol fuels, coal-based fuels, vegetable oils, ammonia, hydrogen, and the like is an urgent need to achieve the "two-carbon" strategic goal. The use of direct in-cylinder injection combustion can achieve efficient use of alternative fuels in internal combustion engines. The in-cylinder direct injection combustion technology refers to that fuel or substances are directly injected into a combustion chamber in a high-pressure state, and high-efficiency combustion is realized by adopting a spark plug ignition, direct compression ignition or ignition mode. The fuel injection device has the advantages that the fuel injection device can realize precisely controlled combustible mixture layering, thermophysical layering and combustion layering by injecting two fuels or substances with different properties in a cylinder, so that the generation of pollutants in the cylinder is reduced, and the thermal efficiency is improved. The main technical schemes for realizing in-cylinder injection of two fuels or substances are two, namely, two injectors are adopted to respectively inject the two fuels or substances, and one injector is adopted to inject the two fuels or substances. For the internal combustion engine of the vehicle, two fuels or substances can be directly injected into the cylinder of one injector due to the limitation of structures such as cylinder diameter, valve and the like.

The use of one injector for achieving direct injection of two fuels, or two substances, in a cylinder places higher demands on the injector structure itself, in particular on the size of the nozzle structure. For example, the design requirement and the process manufacturing difficulty of designing a nested double needle valve structure in one nozzle for the needle valve and the valve body are increased, and the rejection rate of mass production is higher; in the existing double needle valve technical scheme, the power consumption of the injector is increased due to the existence of oil return, so that the work of an engine accessory is increased, and the effective heat-work conversion efficiency of the engine is affected. In the prior technical scheme of double needle valves and single needle valves, the fuel channel is longer, the volume is larger, namely, the channel for communicating the actual sealing surface of the injector with the combustion chamber is longer, thereby reducing the fuel injection control precision and affecting the fuel injection atomization effect.

Disclosure of Invention

To solve at least some of the technical problems described above and other aspects of the prior art, according to an embodiment of one aspect of the present invention, there is provided a fuel injector including:

a first channel suitable for conveying the first fuel and a second channel suitable for conveying the second fuel are arranged in the side wall of the shell;

a valve body, comprising:

the base is arranged in the shell, and a third channel and a fourth channel which are respectively communicated with the first channel and the second channel are formed in the side wall of the base; and

an extension part extending from the housing, the end of the extension part being provided with a plurality of first injection ports and a plurality of second injection ports respectively communicating with the third channel and the fourth channel;

a shutoff member movably disposed within the valve body and configured to move between a first position in which the first injection port and the second injection port are simultaneously closed, and a second position in which the first injection port and the second injection port are simultaneously opened; and

and the actuating assembly is arranged in the shell and is suitable for driving the stop piece to move between a first position and a second position.

In some embodiments of the invention, wherein a through hole penetrating in an axial direction is formed in the valve body, the stopper is slidably installed in the through hole,

a first chamber which is communicated with the third channel and surrounds the stop member is formed in the base of the valve body, a shoulder is formed at the position of the stop member, which is positioned in the first chamber, the first fuel in the third channel generates pressure on the shoulder, so that the stop member has a trend of moving away from the tail end of the valve body, the first chamber is communicated with the first injection port through a gap between the stop member and the inner wall of the through hole,

a fifth passage is arranged in the stop member, one end of the fifth passage is communicated with the fourth passage at a position which is farther away from the extension part relative to the first chamber, the other end of the fifth passage is communicated with the second jet orifice,

preferably, the stop comprises a needle valve.

In some embodiments of the invention, wherein the tip of the protruding portion is configured as a hemispherical portion, a root of the hemispherical portion is provided with a first injection port, a tip of the hemispherical portion is provided with a second injection port,

preferably, the blocking member comprises:

a body portion having a first end coupled to the actuation assembly;

an insertion portion having an outer diameter smaller than an outer diameter of the main body portion and inserted into the hemispherical portion to close or open the second injection port;

and a transition portion located between the main body portion and the insertion portion and formed in an arc shape to be fitted with a root portion of the hemispherical portion to close or open the first injection port.

In some embodiments of the present invention, wherein the end of the insertion portion of the blocking member is formed with an arc-shaped groove communicating with the fifth channel, the blocking member further comprises:

a ball partially received in the arcuate recess; and

a plurality of connectors uniformly spaced along the circumference of the arcuate groove, the plurality of connectors configured to retain the ball member partially within the arcuate groove;

the spherical part and the connecting piece move synchronously with the insertion part, and in the state that the blocking piece is at the first position, the transition part of the blocking piece and the spherical part respectively lean against the first jet orifice and the second jet orifice so as to enable the first jet orifice and the second jet orifice to be closed at the same time; in a state in which the shut-off member is in the second position, the transition portion of the shut-off member and the spherical member are disengaged from the first ejection port and the second ejection port, respectively, so that the first passage, the third passage, and the first ejection port are in communication, and the second passage, the fourth passage, and the fifth passage are in communication with the second ejection port.

In some embodiments of the invention, wherein a second chamber is formed in the housing, the second chamber forms a flange protruding inward toward the base of the valve body, the inner side of the flange extends toward the valve body to form a protrusion,

the actuation assembly includes:

a piezoelectric actuator disposed within the second chamber and extending into the protrusion;

a plurality of first magnets disposed inside the protruding portion;

a plurality of second magnets disposed outside the protruding portion and having magnetism matched with magnetism of the first magnets; and

and a first ring member sleeved between the outer side of the second magnet and the inner wall of the housing, wherein the piezoelectric actuator is configured to drive the first ring member to move between a third position far away from the flange and a fourth position close to the flange through the first magnet and the second magnet.

In some embodiments of the invention, wherein the actuation assembly further comprises a resilient biasing assembly disposed on the base of the valve body, configured to drive the stop member between the first position and the second position in response to movement of the first ring member,

preferably, the elastic pressing assembly includes:

the elastic component is arranged at one end, close to the first annular component, in the through hole of the valve body;

the second annular piece is arranged outside the valve body;

and a third ring member disposed in the valve body and abutting on an end surface of the stopper member remote from the end of the protruding portion, the elastic member being compressed between the second ring member and the third ring member to apply a predetermined elastic force to the stopper member.

In some embodiments of the invention, the method comprises, among other things,

the flange, the protruding part, the inner wall of the shell, the second magnet and the first annular piece enclose a first control chamber, and an opening communicating the first control chamber and the first channel is formed in the shell;

the protrusion, the inner wall of the housing, the second magnet, the first ring member, the elastic pressing assembly, the inner wall of the through hole of the valve body, and the blocking member enclose a second control chamber, the second control chamber is in liquid isolation from the first control chamber, a preset liquid is contained in the second control chamber, and the pressure in the second control chamber changes along with the movement of the first ring member.

In some embodiments of the invention, wherein at least a portion of the first passage located at the opening is configured as a reduced diameter section, the first fuel flowing in the first passage forms a venturi effect in the reduced diameter section to allow the first fuel in the first control chamber to flow through the opening to the first passage.

In some embodiments of the invention, wherein the housing comprises:

an upper housing in which the first and second channels are disposed;

and the lower shell is in threaded connection with the upper shell, the base of the valve body is arranged in the lower shell, and the extending part extends out of the lower shell.

In some embodiments of the invention, an electrical connection assembly is provided at an end of the housing remote from the first ejection port, the electrical connection assembly being adapted to power the piezoelectric actuator.

According to the fuel injector of the embodiment of the invention, the two paths of fuel channels are isolated through the sealing cooperation of the stop piece and the first injection port and the second injection port, so that the synchronous opening and closing of the fuel channels can be realized, and the high-precision injection of fuel is realized by controlling the stop piece through the movement of the actuating component.

Drawings

FIG. 1 schematically illustrates a perspective view of a fuel injector according to an embodiment of the present disclosure;

FIG. 2 schematically illustrates an axial cross-sectional view of a fuel injector according to an embodiment of the present disclosure;

FIG. 3 schematically illustrates an enlarged schematic view of portion A of FIG. 2;

FIG. 4 schematically illustrates an enlarged schematic view of portion B of FIG. 2;

FIG. 5 schematically illustrates an enlarged schematic view of portion C of FIG. 1; and

fig. 6 schematically shows an enlarged schematic view of the portion D in fig. 2.

Description of the reference numerals

1-an upper housing;

11-a first channel;

12-a second channel;

13-flanges;

14-a protrusion;

15-opening;

16-reducing section;

17-a clamping part;

2-a lower housing;

3-a valve body;

31-a base;

311-third channel;

312-fourth channel;

313-a first chamber;

32-an extension;

321-a first ejection port;

322-second ejection port;

323-hemispherical portion;

33-through holes;

34-gap;

4-a stop;

41-shoulder;

42-fifth channel;

43-a body portion;

44-an insertion portion;

45-transition;

46-arc-shaped grooves;

47-ball member;

48-connecting piece;

49-needle valve;

51-piezoelectric actuator;

52-a first magnet;

53-a second magnet;

54-a first ring member;

55-elastic pressing member;

551-an elastic member;

552-a second ring member;

553-third annular piece

6-a first control room;

7-a second control room;

8-an electrical connection assembly;

9-a second chamber.

Detailed Description

The present invention will be further described in detail below with reference to specific embodiments and with reference to the accompanying drawings, in order to make the objects, technical solutions and advantages of the present invention more apparent.

It should be understood that the description is only illustrative and is not intended to limit the scope of the invention. In the following detailed description, for purposes of explanation, numerous specific details are set forth in order to provide a thorough understanding of the embodiments of the invention. It may be evident, however, that one or more embodiments may be practiced without these specific details. In the following description, descriptions of well-known techniques are omitted so as not to unnecessarily obscure the concept of the present invention.

The terminology used herein is for the purpose of describing particular embodiments only and is not intended to be limiting of the invention. The term "comprising" as used herein indicates the presence of a feature, step, operation, but does not preclude the presence or addition of one or more other features.

All terms (including technical and scientific terms) used herein have the same meaning as commonly understood by one of ordinary skill in the art unless otherwise defined. It should be noted that the terms used herein should be construed to have meanings consistent with the context of the present specification and should not be construed in an idealized or overly formal manner.

FIG. 1 schematically illustrates a perspective view of a fuel injector according to an embodiment of the present disclosure; fig. 2 schematically illustrates an axial cross-section of a fuel injector according to an embodiment of the invention.

According to an embodiment of one aspect of the present invention, there is provided a fuel injector, as shown in fig. 1 and 2, including: a housing having a first passage 11 for transporting a first fuel and a second passage 12 for transporting a second fuel provided in a side wall thereof, the side wall of the housing defining a receiving through hole penetrating the housing in an axial direction (up-down direction in fig. 2); valve body 3, comprising: a base 31 installed in the housing, a third channel 311 and a fourth channel 312 communicating with the first channel 11 and the second channel 12, respectively, being formed in a sidewall of the base 31; and an extension portion 32 extending from the housing, the end of the extension portion 32 being provided with a plurality of first ejection openings 321 and a plurality of second ejection openings 322 communicating with the third passage 311 and the fourth passage 312, respectively; a shutoff member 4 movably provided in the valve body 3 and configured to move between a first position where the first injection port 321 and the second injection port 322 are simultaneously closed, and a second position where the first injection port 321 and the second injection port 322 are simultaneously opened; and an actuating assembly disposed within the housing and adapted to drive the stop 4 between the first and second positions.

According to the fuel injector of the above embodiment of the present invention, the two fuel passages are isolated by the sealing engagement of the single shutoff member 4 with the first injection port 321 and the second injection port 322, the synchronous opening and closing of the fuel passages can be achieved, and the shutoff member 4 is controlled to achieve high-precision injection of fuel by the movement of the actuation assembly.

Fig. 3 schematically shows an enlarged schematic view of the portion a in fig. 2.

In some embodiments of the present invention, as shown in fig. 3, a through hole 33 penetrating in the axial direction is formed in the valve body 3, the shut-off member 4 is slidably installed in the through hole 33, a first chamber 313 communicating with the third passage 311 and surrounding the shut-off member 4 is formed in the base 31 of the valve body 3, that is, the third passage 311 is provided between the first passage 11 and the first chamber 313, a portion of the shut-off member 4 located in the first chamber 313 forms a shoulder 41, pressurized first fuel in the third passage 311 presses the shoulder 41 so that the shut-off member 4 has a tendency to move away from the end of the valve body 3, so that the shut-off member 4 moves upward in a case where a downward force acting on the shut-off member 4 is smaller than an upward force component of the first fuel acting on the shoulder 41, the first chamber 313 communicates with the first injection port 321 through a gap 34 between the shut-off member 4 and an inner wall of the through hole 33, a fifth passage 42 is provided in the shut-off member 4, one end of the fifth passage 42 communicates with the fourth passage 312 at a portion farther from the extension 32 than the first chamber 313, and the other end communicates with the fourth injection port 322, and the shut-off member 4 includes a shut-off member 49.

Thus, a first delivery passage adapted to deliver the first fuel is formed by the first passage 11, the third passage 311, the first chamber 313, the gap 34 between the shutoff member 4 and the inner wall of the through hole 33, and the first injection port 321; a second delivery passage adapted to deliver a second fuel is formed by the first passage 12, the fourth passage 312, the fifth passage 42, and the second injection port 322.

FIG. 4 schematically illustrates an enlarged schematic view of portion B of FIG. 2; fig. 5 schematically shows an enlarged schematic view of the portion C in fig. 1.

In some embodiments of the present invention, in which, as shown in fig. 4 and 5, the tip of the protruding portion 32 is configured as a substantially spherical hemispherical portion 323 protruding axially outward, the root of the hemispherical portion 323 is provided with a first injection port 321, the tip of the hemispherical portion 323 is provided with a second injection port 322, and the shutoff member 4 includes: a body portion 43, a first end of the body portion 43 being coupled to an actuation assembly; an insertion portion 44, the outer diameter of the insertion portion 44 being smaller than the outer diameter of the main body portion 43, and being inserted into the hemispherical portion 323 to close or open the second injection port 322; a transition portion 45 located between the main body portion 43 and the insertion portion 44 and formed in an arc shape to be fitted with the root of the hemispherical portion 323 to close or open the first injection port 321. The end of the insertion portion 44 of the blocking member 4 is formed with an arc-shaped groove 46 communicating with the fifth passage 42, and the blocking member 4 further includes: a spherical element 47, partially housed in the arcuate recess 46; and a plurality of connection members 48, the plurality of connection members 48 being disposed at regular intervals in a circumferential direction of the arc-shaped groove 46, the second fuel from the fifth passage 42 flowing to the second injection port 322 through gaps between the connection members 48, the plurality of connection members 48 being configured to partially hold the spherical member 47 within the arc-shaped groove 46; wherein the spherical member 47 and the connecting member 48 move in synchronization with the insertion portion 44, and in a state in which the shutoff member 4 is in the first position, the transition portion 45 of the shutoff member 4 and the spherical member 47 abut against the first injection port 321 and the second injection port 322, respectively, so that the first injection port 321 and the second injection port 322 are closed at the same time; in a state where the shut-off member 4 is in the second position, the transition portion 45 and the spherical member 47 of the shut-off member 4 are disengaged from the first injection port 321 and the second injection port 322, respectively, so that the first passage 11, the third passage 311, and the first injection port 321 are in communication, and the second passage, the fourth passage 312, and the fifth passage 42 are in communication with the second injection port 322.

In the embodiment of the present invention, the connecting member 48 is made of an elastic material, so that an elastic sealing structure formed by the connecting member 48 and the spherical member 47 is provided at the lower end of the needle valve 49, the spherical member 47 forms a sealing surface with the hemispherical portion 323 at the upper portion of the second injection port, the needle valve 49 forms a line seal with the first injection port, and the contact portion of the needle valve 49 with the valve body is in transition sealing engagement for isolating the third passage 311 and the fifth passage.

Further, the connecting member 48 and the spherical member 47 realize that the single needle valve 49 controls the first injection port and the second injection port of the two groups of passages for delivering the first fuel and the second fuel by means of the self-compensating plastic connecting body, thereby avoiding the problem that the first injection port and the second injection port cannot be operated synchronously due to the wear of the sealing surfaces, realizing that the injection start, the continuous injection or the stop of the injection of two or the same fuel or substance in the two delivery passages is controlled simultaneously with high precision by the opening and the closing of one needle valve 49, and achieving the effects of simple structure of the injector and realizing the high-precision injection quantity control.

In some embodiments of the invention, in which, as shown in fig. 6, a second chamber 9 is formed in the housing, a flange 13 protruding toward the inner diameter is formed at a portion of the second chamber 9 near a base 31 of the valve body 3, and an inner side of the flange 13 extends toward the valve body 3 to form a protrusion 14, the actuating assembly includes: a piezoelectric actuator 51 disposed within the second chamber 9 and extending into the projection 14; a plurality of first magnets 52 disposed inside the protruding portion 14; a plurality of second magnets 53 disposed outside the protruding portion 14 and having magnetism that matches the magnetism of the first magnets 52; and a first ring member 54 sleeved between the outer side of the second magnet 53 and the inner wall of the housing, the piezoelectric actuator 51 being configured to drive the first ring member 54 to move between a third position away from the flange 13 and a fourth position close to the flange 13 by the first magnet 52 and the second magnet 53. For example, the first magnet 52 is an N-S-N-S permanent magnet, the second magnet 53 is an S-N-S permanent magnet, and the first magnet 52 and the second magnet 53 are attracted to each other so as to reciprocate synchronously in an axial direction under the driving of the actuating assembly, and the actuating assembly intermittently drives the first annular member by utilizing high-power conversion inverse piezoelectric effect, so that electromagnetic isolation power conduction of the actuating assembly to the stop member is realized.

In some embodiments of the invention, wherein the actuation assembly further comprises a resilient pressing assembly provided on the base of the valve body 3, configured to drive the stop 4 between the first and second positions in response to the movement of the first ring 54, the resilient pressing assembly comprising: an elastic member 551 provided in the through hole 33 of the valve body 3 at one end close to the first ring member 54; a second ring 552 disposed outside the valve body 3; a third annular piece 553 provided in the valve body 3 and abutting on an end face of the stopper 4 remote from the end of the protruding portion 32, the elastic member 551 being compressed between the second annular piece 552 and the third annular piece 553 to apply a predetermined elastic force to the stopper 4. The flange 13, the projection 14, the inner wall of the housing, the second magnet 53 and the first ring member 54 enclose the first control chamber 6, and an opening 15 is formed in the housing communicating the first control chamber 6 with the first passage 11; the protrusion 14, the inner wall of the housing, the second magnet 53, the first ring member 54, the elastic pressing member, the inner wall of the through hole 33 of the valve body 3, and the shut-off member 4 enclose a second control chamber 7, the second control chamber 7 is fluidly isolated from the first control chamber 6, and a predetermined liquid is contained in the second control chamber 7, and the pressure in the second control chamber 7 varies with the movement of the first ring member 54. The downward equivalent force of the liquid in the second control chamber (preset liquid) against the needle valve 49 is PLWS, the upward equivalent force of the liquid in the first chamber (first fuel) against the needle valve 49 is PLWX, the gravity of the needle valve 49 is G, the pressure of the elastic member against the needle valve 49 is PT, and when g+pt+plws > PLWX, the needle valve 49 is in the first position, and the first injection ports 321 and the second injection ports 322 are simultaneously closed; when the first ring 54 moves closer to the flange 13, the second control chamber decreases PLWS due to the volume increase, the needle valve 49 moves from the first position to the second position, and the first injection ports 321 are opened simultaneously with the second injection ports 322.

In some embodiments of the invention, wherein at least a portion of the first passage 11 located at the opening 15 is configured as a reduced diameter section 16, the first fuel flowing in the first passage 11 forms a venturi effect in the reduced diameter section to allow the first fuel in the first control chamber 6 to flow through the opening 15 to the first passage 11. The venturi effect is represented by the phenomenon that when the restricted flow passes through the reduced flow cross section, the flow velocity of the fluid increases, the flow velocity of the fluid is inversely proportional to the flow cross section, and low pressure is generated near the fluid flowing at high speed, so that adsorption is generated, and the first fuel in the first control chamber 6 flows into the first channel 11 through the opening 15 under the venturi effect. The venturi effect formed by the reducing section and the electromagnetic isolation control formed by the actuating assembly realize oil return-free injection control, and the oil return-free injection control realizes the opening and closing of the needle valve 49 with low energy consumption and high precision, so that the low-power-consumption operation effect is achieved.

In some embodiments of the invention, wherein the housing comprises: an upper case 1, a first passage 11 and a second passage 12 are provided in the upper case 1; the lower housing 2 is screwed with the upper housing 1, the base of the valve body 3 is installed in the lower housing 2, and the protruding portion 32 protrudes from the lower housing 2. The end of the housing remote from the first ejection port 321 is provided with an electrical connection assembly 8, the electrical connection assembly 8 being adapted to power the piezoelectric actuator 51. In the present embodiment, as shown in fig. 1, a clamping portion 17 for fixing the fuel injector is further provided on the upper case 1 to mount the fuel injector on the engine.

In some embodiments of the invention, the fuel injector has four operating conditions, including:

the fuel injector stops injecting: the piezoelectric actuator 51 which is not powered is in a free extension state, the lower part of the piezoelectric actuator 51 is in a lower limit position of control movement, and the annular piece 54 is also in the lower limit position of control movement under the action of the first magnet 52 and the second magnet 53; at this time, the force condition of the needle valve 49 is g+pt+plws > PLWX, and the transition portion 45 and the spherical member 47 of the needle valve 49 seal the first injection port 321 and the second injection port 322, respectively, so that the first and second fuels or substances in the first and second delivery passages stop being injected.

Fuel injector on injection: a certain voltage is applied to the piezoelectric actuator 51 through an external control line, the piezoelectric actuator 51 is contracted by the inverse piezoelectric effect to drive the lower part of the piezoelectric actuator 51 to move upwards, and the annular piece 54 moves upwards under the action of the first magnet 52 and the second magnet 53; the upward movement of the ring 54 presses the first liquid or substance in the first control chamber 6 to be transferred to the third passage 311 through the opening 15, PLWS becomes smaller, and when g+pt+plws < PLWX, the upward movement of the needle valve 49 causes the transition portion 45 and the ball member 47 of the needle valve 49 to disengage from the first injection port 321 and the second injection port 322, respectively, the first and second delivery passages communicating with the combustion chamber, respectively, and the first and second fuels or substances in the first and second delivery passages opening the injection passage combustion chamber.

The fuel injector continues to inject: the needle valve 49 moves upward, PT increases, the upward movement of the needle valve 49 is stopped when g+pt+plws=plwx, when the fuel or substance injection in the third passage 311 reaches a certain flow rate, the second fuel or substance in the first control chamber 6 continues to be transferred to the third passage 311 by the venturi effect, the pressure in the first control chamber 6 decreases to drive the ring member 54 to move upward and then drive the needle valve 49 to continue to move upward, the lower portion of the piezoelectric actuator 51 is maintained at a predetermined position by controlling the voltage applied to the piezoelectric actuator 51, the ring member 54 is further controlled to be positioned such that the needle valve 49 is maintained at the maximum upward displacement, that is, the upper limit position, the equivalent cross section of the communication between the first and second delivery passages and the combustion chamber is maximized, and the maximum continuous injection of the first and second fuel or substance in the first and second delivery passages is achieved.

Fuel injector reduced injection: decreasing the voltage at the piezoelectric actuator 51 causes the lower portion of the piezoelectric actuator 51 to move downward stepwise, which in turn causes the ring 54 and the needle valve 49 to move downward, the equivalent cross-section of the first and second delivery passages communicating with the combustion chamber decreases, the first and second fuel or substance injection rates in the first and second delivery passages decrease, the lower portion of the piezoelectric actuator 51 is in the lower limit position of the control movement when no voltage is applied to the piezoelectric actuator 51, and the needle valve 49 transition portion 45 and the ball 47 seal the first injection port 321 and the second injection port 322, respectively, such that the first and second fuel or substance injection in the first and second delivery passages stops.

According to the fuel injector of the above embodiment of the present invention, the needle valve 49 can simultaneously isolate two fuel or substance passages through the spherical member 47 and the transition portion 45, the connecting member 48 and the spherical member 47 realize that the single needle valve 49 controls the first injection port and the second injection port of the two groups of passages for delivering the first fuel and the second fuel by means of the self-compensating plastic connecting body, thereby avoiding the problem that the first injection port and the second injection port cannot be operated synchronously due to the wear of the sealing surfaces, realizing that the injection, the continuous injection or the stop of the two or the same fuel or substance in the two delivery passages is simultaneously controlled with high precision by the opening and closing of one needle valve 49, and achieving the effects of simple structure of the injector and realizing the high-precision injection quantity control. The embodiment of the invention adopts the linear sealing surface and the liquid pressure auxiliary sealing, the fuel or substance injection control precision is high, the electromagnetic isolation control formed by the venturi effect formed by the reducing section and the actuating component realizes the oil return-free injection control, and the oil return-free injection control realizes the opening and closing of the needle valve 49 with low energy consumption and high precision, thereby achieving the effect of low-power consumption operation. The piezoelectric actuator 51 in the embodiment of the invention adopts a piezoelectric ceramic actuator, realizes high-precision control by utilizing the inverse piezoelectric effect, and has a simple and reasonable arrangement structure.

Thus, embodiments of the present invention have been described in detail with reference to the accompanying drawings. It should be noted that, in the drawings or the text of the specification, implementations not shown or described are all forms known to those of ordinary skill in the art, and not described in detail. Furthermore, the above definitions of the components are not limited to the specific structures, shapes or modes mentioned in the embodiments, and may be simply modified or replaced by those of ordinary skill in the art.

It should also be noted that in the embodiments of the present invention, unless otherwise known, numerical parameters in the present specification and attached claims are approximations that may vary depending upon the desired properties sought to be obtained by the present invention. In particular, all numbers expressing dimensions, range conditions, and so forth, used in the specification and claims are to be understood as being modified in all instances by the term "about". In general, the meaning of expression is meant to include a variation of + -10% in some embodiments, a variation of + -5% in some embodiments, a variation of + -1% in some embodiments, and a variation of + -0.5% in some embodiments by a particular amount.

Those skilled in the art will appreciate that the features recited in the various embodiments of the invention and/or in the claims may be combined in various combinations and/or combinations, even if such combinations or combinations are not explicitly recited in the invention. In particular, the features recited in the various embodiments of the invention and/or in the claims can be combined in various combinations and/or combinations without departing from the spirit and teachings of the invention. All such combinations and/or combinations fall within the scope of the invention.

The foregoing description of the embodiments has been provided for the purpose of illustrating the general principles of the invention, and is not meant to limit the invention thereto, but to limit the invention thereto, and any modifications, equivalents, improvements and equivalents thereof may be made without departing from the spirit and principles of the invention.

Claims

1. A fuel injector, comprising:

the device comprises a shell, wherein a first channel suitable for conveying first fuel and a second channel suitable for conveying second fuel are arranged in the side wall of the shell, a second chamber is formed in the shell, a flange protruding towards the inner diameter is formed at the position, close to a base of the valve body, of the second chamber, and the inner side of the flange extends towards the valve body to form a protruding part;

a valve body, comprising:

a base mounted in the housing, a third channel communicating with the first channel and a fourth channel communicating with the second channel being formed in a side wall of the base; and

a protruding portion protruding from the housing, a plurality of first injection ports communicating with the third passage and a plurality of second injection ports communicating with a fourth passage being provided at a tip of the protruding portion;

a shutoff member movably disposed within the valve body and configured to move between a first position in which the first and second injection ports are simultaneously closed and a second position in which the first and second injection ports are simultaneously opened; and

an actuation assembly disposed within the housing and adapted to drive the stop member between the first position and the second position, the actuation assembly comprising:

a plurality of first magnets disposed inside the protruding portion;

a first ring member sleeved between an outer side of the second magnet and an inner wall of the housing, the piezoelectric actuator being configured to drive the first ring member to move between a third position away from the flange and a fourth position close to the flange by the first magnet and the second magnet;

a through hole penetrating in an axial direction is formed in the valve body, the blocking member is slidably installed in the through hole, a first chamber which is communicated with the third channel and surrounds the blocking member is formed in a base of the valve body, a shoulder is formed at a position of the blocking member, which is positioned in the first chamber, and first fuel in the third channel presses the shoulder, so that the blocking member has a tendency to move away from the tail end of the valve body, and the first chamber is communicated with the first injection port through a gap between the blocking member and the inner wall of the through hole;

a fifth channel is arranged in the stop piece, one end of the fifth channel is communicated with the fourth channel at a position far away from the extension part relative to the first chamber, and the other end of the fifth channel is communicated with the second jet orifice;

and voltage is applied to the piezoelectric actuator through an external control wire, the piezoelectric actuator is contracted by the inverse piezoelectric effect to drive the lower part of the piezoelectric actuator to move upwards, the first annular piece moves upwards under the action of the first magnet and the second magnet, and the first annular piece moves upwards to squeeze the first fuel of the first control chamber to transfer to the third channel through the opening.

2. The fuel injector of claim 1, wherein the shut-off member comprises a needle valve.

3. The fuel injector according to claim 1, wherein a tip of the protruding portion is configured as a hemispherical portion, a root of the hemispherical portion is provided with the first injection port, and a tip of the hemispherical portion is provided with the second injection port.

4. A fuel injector as claimed in claim 3, wherein the shut-off member comprises:

a body portion having a first end coupled to the actuation assembly;

5. The fuel injector of claim 4, wherein a tip of the insert of the shut-off member is formed with an arcuate groove in communication with the fifth passage, the shut-off member further comprising:

a ball partially received in the arcuate recess; and

a plurality of connectors uniformly spaced along the circumference of the arcuate groove, the plurality of connectors configured to retain the ball partially within the arcuate groove;

the spherical member and the connecting member move synchronously with the insertion portion, the transition portion of the blocking member abuts against the first injection port in the state that the blocking member is at the first position, and the spherical member of the blocking member abuts against the second injection port, so that the first injection port and the second injection port are closed at the same time; and in a state that the blocking piece is at the second position, the transition part of the blocking piece is separated from the first jet orifice, the spherical piece of the blocking piece is separated from the second jet orifice, so that the first channel, the third channel and the first jet orifice are communicated, and the second channel, the fourth channel, the fifth channel and the second jet orifice are communicated.

6. The fuel injector of any one of claims 1 to 5, wherein the actuation assembly further comprises a resilient biasing assembly disposed on a base of the valve body, configured to drive movement of the stop between the first and second positions in response to movement of the first ring.

7. The fuel injector of claim 6, wherein the resilient biasing assembly comprises:

the second annular piece is arranged outside the valve body;

and a third ring member disposed in the valve body and abutting on an end face of the stopper distal from the protruding portion, the elastic member being compressed between the second ring member and the third ring member to apply a predetermined elastic force to the stopper.

8. The fuel injector of claim 6, wherein,

the protrusion, the inner wall of the housing, the second magnet, the first ring-shaped member, the elastic pressing assembly, the inner wall of the through hole of the valve body, and the stop member enclose a second control chamber, the second control chamber is in liquid isolation with the first control chamber, a preset liquid is contained in the second control chamber, and the pressure in the second control chamber changes along with the movement of the first ring-shaped member.

9. The fuel injector of claim 8, wherein at least a portion of the first passage located at the opening is configured as a reduced diameter section at which the first fuel flowing in the first passage forms a venturi effect to allow the first fuel in the first control chamber to flow through the opening to the first passage.

10. The fuel injector of any one of claims 1-5, wherein the housing comprises:

an upper housing, the first and second channels being disposed within the upper housing;

and the lower shell is in threaded connection with the upper shell, the base of the valve body is arranged in the lower shell, and the protruding part protrudes from the lower shell.

11. The fuel injector of any one of claims 1-5, wherein an end of the housing remote from the first injection port is provided with an electrical connection assembly adapted to power the piezoelectric actuator.