CN115288898A

CN115288898A - Fuel injector

Info

Publication number: CN115288898A
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: 2022-11-04
Anticipated expiration: 2042-07-20
Also published as: CN115288898B

Abstract

The invention discloses a fuel injector, comprising: the fuel injection device comprises a shell, wherein a first channel suitable for conveying a first fuel and a second channel suitable for conveying a 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; the tail end of the extension part is provided with a plurality of first injection ports and a plurality of second injection ports which are respectively communicated with the third channel and the fourth channel; a stopper movably disposed in the valve body and configured to move between a first position where the first injection port and the second injection port are simultaneously closed and a second position where the first injection port and the second injection port are simultaneously opened; and an actuating assembly arranged in the shell and suitable for driving the stopping piece to move between the first position and the second position. The first injection port and the second injection port are closed and opened simultaneously by the movement of the stopping member, so that the fuel injector has a simple structure and low energy consumption, and the fuel injection control precision is improved while two kinds of fuel are injected.

Description

Fuel injector

Technical Field

The invention relates to the technical field of engines, in particular to a fuel injector with a direct injection double channel in a cylinder, which is suitable for an engine.

Background

At present, the search for internal combustion engine fuels such as alcohol fuels, coal-based fuels, vegetable oils, ammonia and hydrogen to replace petroleum is an urgent need to achieve the strategic goal of "double carbon". The adoption of direct injection combustion in the cylinder can realize the high-efficiency utilization of the alternative fuel in the internal combustion engine. The in-cylinder direct injection combustion technology means that fuel or substances are directly injected into a combustion chamber in a high-pressure state, and efficient combustion is realized by adopting a spark plug ignition mode, a direct compression ignition mode or an ignition mode. In-cylinder injection of two fuels or two substances with different attributes can realize accurate control of combustible mixed gas layering, thermophysical layering and combustion layering, so that in-cylinder pollutant generation is reduced and heat efficiency is improved. There are two main technical solutions for realizing the in-cylinder injection of two fuels or substances, that is, two injectors for injecting two fuels or substances respectively and one injector for injecting two fuels or substances. For the internal combustion engine for the vehicle, two fuels or substances can be directly injected into one injector cylinder due to the limitation of the structures of the cylinder diameter, the valve and the like.

The use of a single injector to achieve direct injection of two fuels, or two substances, into the cylinder places greater demands on the injector design itself, particularly the size of the nozzle design. For example, the design requirements and the process manufacturing difficulty of a needle valve and a valve body are increased by designing a nested double-needle valve structure in one nozzle, and the rejection rate of batch production is high; in the existing technical scheme of the double needle valve, the power consumption of the ejector is increased due to the existence of oil return, so that the accessory power of the engine is increased, and the effective heat-work conversion efficiency of the engine is influenced. In the technical scheme of the existing double needle valve and single needle valve, 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, so that the fuel injection control precision is reduced and the fuel injection atomization effect is influenced.

Disclosure of Invention

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

the fuel injection device comprises a shell, wherein a first channel suitable for conveying a first fuel and a second channel suitable for conveying a 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

the extension part extends out of the shell, and the tail end of the extension part is provided with a plurality of first injection ports and a plurality of second injection ports which are respectively communicated with the third channel and the fourth channel;

a stopper movably disposed in the valve body and configured to move between a first position where the first injection port and the second injection port are simultaneously closed and a second position where 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 stopping piece to move between the first position and the second position.

In some embodiments of the present invention, in which a through hole penetrating in an axial direction is formed in the valve body, the shut-off member is slidably installed in the through hole,

a first cavity communicated with the third channel and surrounding the stopping piece is formed in the base of the valve body, a shoulder is formed at the position, located in the first cavity, of the stopping piece, the first fuel in the third channel generates pressure on the shoulder, so that the stopping piece has the tendency of moving away from the tail end of the valve body, the first cavity is communicated with the first injection port through a gap between the stopping piece and the inner wall of the through hole,

a fifth passage is provided in the stopper, one end of the fifth passage communicates with the fourth passage at a position farther from the projecting portion with respect to the first chamber, and the other end communicates with the second ejection port,

preferably, the shut-off member comprises a needle valve.

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

preferably, the shut-off member comprises:

a main body portion, a first end of the main body portion being coupled to the actuating assembly;

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

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

In some embodiments of the present invention, wherein the end of the insertion portion of the shut-off member is formed with an arc-shaped groove communicating with the fifth passage, the shut-off member further includes:

a spherical member partially received in the arcuate recess; and

a plurality of connecting members arranged at regular intervals in a circumferential direction of the arc-shaped groove, the plurality of connecting members being configured to partially hold the spherical member in the arc-shaped groove;

the spherical part and the connecting piece move synchronously with the inserting part, and the transition part and the spherical part of the stopping piece respectively abut against the first injection port and the second injection port under the condition that the stopping piece is at the first position, so that the first injection port and the second injection port are simultaneously closed; in a state where the cut-off member is at the second position, the transition portion and the spherical member of the cut-off member are disengaged from the first injection port and the second injection port, respectively, so that the first passage, the third passage and the first injection port are in conduction, and the second passage, the fourth passage, the fifth passage and the second injection port are in conduction.

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

the actuating assembly includes:

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

a plurality of first magnets disposed inside the protrusion;

a plurality of second magnets disposed outside the protrusion and having magnetism cooperating with that of the first magnets; and

and the piezoelectric actuator is configured to drive the first annular piece 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 actuating assembly further comprises a resilient biasing assembly disposed on the base of the valve body and 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 piece, in the through hole of the valve body;

a second ring member disposed outside the valve body;

and a third ring member disposed in the valve body and abutting on an end surface of the stopper member distal 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 present invention, wherein,

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 communicated with the first control chamber and the first channel is formed in the shell;

the protruding portion, the inner wall of the shell, the second magnet, the first annular piece, the elastic pressing assembly, the inner wall of the through hole of the valve body and the stopping piece form a second control chamber in an enclosed mode, the second control chamber is isolated from the first control chamber in a liquid mode, 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 annular piece.

In some embodiments of the invention, wherein at least a portion of the first passage at the opening is configured as a reduced diameter section, the first fuel flowing in the first passage forms a venturi effect at 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:

the first channel and the second channel are arranged in the upper shell;

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

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

According to the fuel injector of the embodiment of the invention, the two fuel passages are isolated through the sealing fit of the stopping piece with the first injection port and the second injection port, the synchronous opening and closing of the fuel passages can be realized, and the stopping piece is controlled to realize the high-precision injection of the fuel through the movement of the actuating assembly.

Drawings

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

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

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

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

FIG. 5 schematically shows an enlarged schematic view of section C of FIG. 1; and

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

Description of the reference numerals

1-an upper shell;

11-a first channel;

12-a second channel;

13-a flange;

14-a protrusion;

15-opening;

16-a reducing section;

17-a clamping portion;

2-a lower shell;

3-a valve body;

31-a base;

311-a third channel;

312-a fourth channel;

313-a first chamber;

32-an extension;

321-first injection ports;

322-second injection ports;

323-hemispherical portion;

33-a via hole;

34-a gap;

4-a stop;

41-shoulder;

42-a fifth channel;

43-a body portion;

44-an insertion portion;

45-a transition;

46-an arc-shaped groove;

47-a ball;

48-a connector;

49-needle valve;

5-an actuating assembly;

51-a piezoelectric actuator;

52-a first magnet;

53-a second magnet;

54-a first annular member;

55-elastic pressing piece;

551-an elastic member;

552-a second ring member;

553-third Ring piece

6-a first control room;

7-a second control room;

8-an electrical connection assembly;

9-second chamber.

Detailed Description

In order to make the objects, technical solutions and advantages of the present invention more apparent, the present invention is further described in detail with reference to the accompanying drawings in combination with the embodiments.

It is to be understood that such description is merely illustrative and not intended to limit the scope of the present 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. Moreover, in the following description, descriptions of well-known technologies are omitted so as to avoid unnecessarily obscuring the concepts 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 the features, steps, operations 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 to which this invention belongs, unless otherwise defined. It is noted that the terms used herein should be interpreted as having a meaning that is consistent with the context of this specification and should not be interpreted in an idealized or overly formal sense.

FIG. 1 schematically illustrates a perspective view of a fuel injector, according to an embodiment of the invention; FIG. 2 schematically illustrates an axial cross-sectional view of a fuel injector according to an embodiment of the invention.

According to an embodiment of an aspect of the present invention, there is provided a fuel injector, as shown in fig. 1, 2, including: a housing, a first passage 11 adapted to convey a first fuel and a second passage 12 adapted to convey a second fuel being provided in a side wall of the housing, the side wall of the housing defining a housing through-hole penetrating the housing in an axial direction (vertical direction in fig. 2); a valve body 3, comprising: a base 31 installed in the connection housing, a third passage 311 and a fourth passage 312 respectively communicating with the first passage 11 and the second passage 12 being formed in a sidewall of the base 31; and a protruding portion 32 protruding from the housing, a tip end of the protruding portion 32 being provided with a plurality of first injection ports 321 and a plurality of second injection ports 322 communicating with the third passage 311 and the fourth passage 312, respectively; a stopper 4 movably disposed 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 5, arranged inside the casing, suitable for driving the stop member 4 between the first position and the second position.

According to the fuel injector of the above embodiment of the present invention, the single shut-off member 4 is in sealing engagement with the first injection ports 321 and the second injection ports 322 to isolate the two fuel passages, so that the fuel passages can be opened and closed synchronously, and the shut-off member 4 is controlled to inject fuel with high precision by the movement of the actuating assembly.

Fig. 3 schematically shows an enlarged schematic view of a 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 mounted 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 shoulder 41 is formed in a portion of the shut-off member 4 located in the first chamber 313, the pressurized first fuel in the third passage 311 generates a pressure on the shoulder 41, so that the shut-off member 4 has a tendency to move away from the tip of the valve body 3, so that the shut-off member 4 moves upward in a case where the downward force acting on the shut-off member 4 is smaller than the upward component force 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 the 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 projecting from the first chamber 313, and the other end communicates with the second injection port 322, and the needle valve 4 includes a needle valve opening 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 shut-off member 4 and the inner wall of the through hole 33, and the first injection port 321; a second delivery passage adapted to deliver the second fuel is formed by the first passage 12, the fourth passage 312, the fifth passage 42, and the second injection ports 322.

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

In some embodiments of the present invention, wherein, 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, a first injection port 321 is provided at the root of the hemispherical portion 323, a second injection port 322 is provided at the top of the hemispherical portion 323, and the blocking piece 4 includes: a main body portion 43, a first end of the main body portion 43 being coupled with the actuating assembly 5; an insertion portion 44 having an outer diameter smaller than that of the body portion 43 and inserted into the hemispherical portion 323 to close or open the second injection port 322; and a transition portion 45 between the main body portion 43 and the insertion portion 44 and formed in an arc shape to be fitted to a root of the hemispherical portion 323 to close or open the first injection port 321. The end of the insertion portion 44 of the shut-off member 4 is formed with an arc-shaped groove 46 communicating with the fifth passage 42, and the shut-off member 4 further includes: a spherical member 47 partially received in the arcuate recess 46; and a plurality of connection pieces 48, the plurality of connection pieces 48 being evenly spaced along the circumferential direction of the arc-shaped groove 46, the second fuel from the fifth passage 42 flowing to the second injection port 322 through a gap between the connection pieces 48, the plurality of connection pieces 48 being configured to partially hold the ball 47 in the arc-shaped groove 46; wherein, the spherical member 47 and the connecting member 48 move synchronously with the insertion portion 44, and the transition portion 45 and the spherical member 47 of the cut-off member 4 respectively abut against the first injection port 321 and the second injection port 322 in a state that the cut-off member 4 is at the first position, so that the first injection port 321 and the second injection port 322 are simultaneously closed; in the state where the cut-off member 4 is at the second position, the transition portion 45 and the spherical member 47 of the cut-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 brought into conduction, and the second passage, the fourth passage 312, the fifth passage 42 and the second injection port 322 are brought into conduction.

In the embodiment of the present invention, the connection member 48 is made of an elastic material, so that an elastic sealing structure formed by the connection 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 from the fifth passage.

Further, the connection member 48 and the spherical member 47 realize that the single needle valve 49 controls the first injection ports and the second injection ports of the two sets of passages for delivering the first fuel and the second fuel in a self-compensating plastic connection manner, thereby avoiding the problem that the first injection ports and the second injection ports cannot be operated synchronously due to the wear of the sealing surface, realizing the simultaneous control of the start of injection, the continuous injection or the stop of injection of two or the same fuels or substances in the two delivery passages with high accuracy by the opening and closing of one needle valve 49, and achieving the effects of simple structure of the injector and realizing the control of the injection amount with high accuracy.

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

In some embodiments of the present invention, wherein, 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 position of the second chamber 9 close to the base 31 of the valve body 3, and the inner side of the flange 13 extends toward the valve body 3 to form a protrusion 14, the actuating assembly 5 includes: a piezoelectric actuator 51 disposed within the second chamber 9 and extending into the protrusion 14; a plurality of first magnets 52 provided inside the protruding portion 14; a plurality of second magnets 53 provided outside the protruding portion 14 and having magnetism cooperating with the magnetism of the first magnets 52; and a first ring member 54 fitted between the outside 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-N-S permanent magnet, the second magnet 53 is an S-N-S-N-S-N permanent magnet, the first magnet 52 and the second magnet 53 are mutually adsorbed to reciprocate and synchronously move in the axial direction under the driving of the actuating assembly, the actuating assembly intermittently drives the first annular member by utilizing a high-power electricity conversion inverse piezoelectric effect, and the electromagnetic isolation power transmission of the actuating assembly to the stopping member is realized.

In some embodiments of the invention, wherein the actuation assembly 5 further comprises a resilient pressing assembly provided on the base of the valve body 3, configured to drive the stop member 4 in response to a movement of the first ring 54 between the first position and the second position, the resilient pressing assembly comprises: an elastic member 551 provided in the through hole 33 of the valve body 3 near one end of the first ring 54; a second annular member 552 provided outside the valve body 3; a third ring 553 disposed inside the valve body 3 and abutting on an end face of the stopper 4 distal from the end of the projection 32, the elastic member 551 being compressed between the second ring 552 and the third ring 553 to apply a predetermined elastic force to the stopper 4. The flange 13, the protrusion 14, the inner wall of the housing, the second magnet 53 and the first ring 54 enclose a first control chamber 6, and an opening 15 communicating the first control chamber 6 and the first channel 11 is formed in the housing; the protruding part 14, the inner wall of the housing, the second magnet 53, the first ring-shaped member 54, the elastic pressing assembly, the inner wall of the through hole 33 of the valve body 3, and the stopping member 4 enclose a second control chamber 7, the second control chamber 7 is in liquid isolation from the first control chamber 6, a preset liquid is contained in the second control chamber 7, and the pressure in the second control chamber 7 is changed along with the movement of the first ring-shaped member 54. The downward equivalent force of the liquid (preset liquid) in the second control chamber to the needle valve 49 is PLWS, the upward equivalent force of the liquid (first fuel) in the first chamber to the needle valve 49 is PLWX, the gravity of the needle valve 49 is G, the pressure of the elastic member to 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 closed at the same time; when the first ring 54 moves closer to the flange 13, the second control chamber decreases in volume due to the PLWS decreasing, the needle valve 49 moves from the first position to the second position, and the first injection ports 321 and the second injection ports 322 are opened simultaneously.

In some embodiments of the present invention, wherein at least a portion of the first channel 11 located at the opening 15 is configured as a reduced diameter section 16, the first fuel flowing in the first channel 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 channel 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 is increased, the flow velocity is inversely proportional to the flow cross section, 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 action of the venturi effect. The venturi effect formed by the necking 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, thereby achieving the effect of low power consumption operation.

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

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

fuel injector stop injection: 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 part 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 needle valve 49 is forced to G + PT + PLWS > PLWX, and the transition portion 45 and the spherical member 47 of the needle valve 49 seal the first injection ports 321 and the second injection ports 322, respectively, so that the first and second fuels or substances in the first and second delivery passages stop being injected.

Fuel injector opening 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 part 54 also moves upwards under the action of the first magnet 52 and the second magnet 53; the ring member 54 moves upward to press 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 small, and when G + PT + PLWS < PLWX, the needle valve 49 moves upward so that the transition portion 45 of the needle valve 49 and the spherical member 47 are separated from the first injection port 321 and the second injection port 322, respectively, the first and second delivery passages are communicated with the combustion chamber, respectively, and the first and second fuels or substances in the first and second delivery passages open the injection passage to the combustion chamber.

The fuel injector continuously injects: the needle valve 49 moves upwards, the PT is increased, when G + PT + PLWS = PLWX, the needle valve 49 stops moving upwards, when the fuel or substance injection in the third channel 311 reaches a certain flow rate, the second fuel or substance in the first control chamber 6 is continuously transferred to the third channel 311 under the action of the Venturi effect, the pressure of the first control chamber 6 is reduced to drive the ring piece 54 to move upwards and further drive the needle valve 49 to continuously move upwards, the lower position of the piezoelectric actuator 51 is kept at a preset position by controlling the voltage applied to the piezoelectric actuator 51, the position of the ring piece 54 is further controlled, the needle valve 49 is kept at the maximum upward displacement, namely at the upper limit position, the equivalent cross section of the communication between the first delivery channel and the combustion chamber is maximum, and the first fuel or substance in the first delivery channel and the second delivery channel is continuously injected to the maximum.

Fuel injector reduced injection: the voltage applied to the piezoelectric actuator 51 is reduced, so that the lower part of the piezoelectric actuator 51 moves downwards gradually to drive the ring-shaped member 54 and the needle valve 49 to move downwards, the equivalent cross section of the first delivery passage and the equivalent cross section of the second delivery passage communicated with the combustion chamber is reduced, the injection rate of the first fuel or substance in the first delivery passage and the injection rate of the second fuel or substance in the second delivery passage are reduced, when the piezoelectric actuator 51 does not apply the voltage, the lower part of the piezoelectric actuator 51 is at the lower limit position for controlling the movement, and the transition part 45 and the spherical member 47 of the needle valve 49 respectively seal the first injection port 321 and the second injection port 322, so that the injection of the first fuel or substance in the first delivery passage and the second delivery passage is stopped.

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, and the connection member 48 and the spherical member 47 realize that a single needle valve 49 controls the first injection ports and the second injection ports of two sets of passages for delivering the first fuel and the second fuel in a self-compensating plastic connection manner, thereby avoiding the problem that the first injection ports and the second injection ports cannot be operated synchronously due to the abrasion of the sealing surface, 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 can be simultaneously controlled with high precision through the opening and closing of one needle valve 49, and achieving the effects of simple structure of the injector and realizing the control of the injection quantity with high precision. The embodiment of the invention adopts a linear sealing surface and liquid pressure auxiliary sealing, the fuel or material injection control precision is high, the electromagnetic isolation control formed by the Venturi effect formed by the necking section and the actuating assembly realizes the oil return-free injection control, the oil return-free injection control realizes the opening and closing of the needle valve 49 with low energy consumption and high precision, and the effect of low power consumption operation is achieved. The piezoelectric actuator 51 in the embodiment of the present invention is a piezoelectric ceramic actuator, and realizes high-precision control by using an inverse piezoelectric effect, and the arrangement structure is simple and reasonable.

So far, the embodiments of the present invention have been described in detail with reference to the accompanying drawings. It is to be noted that, in the attached drawings or in the description, the implementation modes not shown or described are all the modes known by the ordinary skilled person in the field of technology, and are not described in detail. In addition, the above definitions of the components are not limited to the specific structures, shapes or manners mentioned in the embodiments, and those skilled in the art may easily modify or replace them.

It should also be noted that in the particular examples of the invention, unless otherwise indicated, the numerical parameters set forth in the specification and attached claims are approximations that can vary depending upon the desired properties sought to be obtained by the teachings of the present invention. In particular, all numbers expressing dimensions of components, ranges, and so forth used in the specification and claims are to be understood as being modified in all instances by the term "about". Generally, the expression is meant to encompass variations of ± 10% in some embodiments, 5% in some embodiments, 1% in some embodiments, 0.5% in some embodiments by the specified amount.

It will be appreciated by a person skilled in the art that various combinations and/or combinations of features described in the various embodiments and/or in the claims of the invention are possible, even if such combinations or combinations are not explicitly described in the invention. In particular, various combinations and/or combinations of the features recited in the various embodiments and/or claims of the present invention may be made without departing from the spirit or teaching of the invention. All such combinations and/or associations fall within the scope of the present invention.

The above-mentioned embodiments, objects, technical solutions and advantages of the present invention are further described in detail, it should be understood that the above-mentioned embodiments are only examples of the present invention, and should not be construed as limiting the present invention, and any modifications, equivalent substitutions, improvements and the like made within the spirit and principle of the present invention should be included in the protection scope of the present invention.

Claims

1. A fuel injector, comprising:

a valve body, comprising:

the tail end of the extension part is provided with a plurality of first injection ports and a plurality of second injection ports which are respectively communicated with the third channel and the fourth channel;

a stopper movably disposed in the valve body and configured to move between a first position where the first and second injection ports are simultaneously closed and a second position where the first and second injection ports 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.

2. The fuel injector of claim 1, wherein a through hole is formed in the valve body to pass therethrough in an axial direction, the stopper is slidably mounted in the through hole,

a first cavity which is communicated with the third channel and surrounds the stop piece is formed in the base of the valve body, a shoulder is formed at the position, located in the first cavity, of the stop piece, pressure is generated on the shoulder by the first fuel in the third channel, the stop piece is enabled to have a tendency of moving away from the tail end of the valve body, and the first cavity is communicated with the first injection port through a gap between the stop piece and the inner wall of the through hole;

a fifth passage is arranged in the stopping piece, one end of the fifth passage is communicated with the fourth passage at a position which is far away from the protruding part relative to the first chamber, and the other end of the fifth passage is communicated with the second jet port;

preferably, the shut-off member comprises a needle valve.

3. The fuel injector of claim 2, wherein a tip of the protruding portion is configured as a hemispherical portion, a root of the hemispherical portion providing the first injection port, a top of the hemispherical portion providing the second injection port;

preferably, the shut-off member comprises:

a body portion, a first end of the body portion being coupled to the actuating assembly;

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

a transition portion 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.

4. The fuel injector of claim 3, wherein a tip of the insertion portion of the stopper is formed with an arc-shaped groove communicating with the fifth passage, the stopper further comprising:

a ball partially received in the arcuate recess; and

the spherical piece and the connecting piece move synchronously with the inserting part, and the transition part and the spherical piece of the stopping piece respectively abut against the first injection port and the second injection port under the condition that the stopping piece is at the first position, so that the first injection port and the second injection port are simultaneously closed; in a state where the cut-off member is at the second position, the transition portion and the spherical member of the cut-off member are separated from the first injection port and the second injection port, respectively, so that the first passage, the third passage and the first injection port are communicated, and the second passage, the fourth passage, the fifth passage and the second injection port are communicated.

5. The fuel injector of any of claims 1-4, wherein a second chamber is formed within the housing, a portion of the second chamber proximate the base of the valve body forming a radially inwardly projecting flange, an inner side of the flange extending toward the valve body forming a protrusion,

the actuating assembly includes:

a plurality of first magnets disposed inside the protrusion;

a plurality of second magnets disposed outside the protrusion and having magnetism matched with that of the first magnets; and

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

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

preferably, the elastic pressing assembly includes:

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

a second ring member disposed outside the valve body;

and a third ring member provided in the valve body and abutting on an end surface of the stopper distal 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.

7. The fuel injector of claim 6,

the protruding portion, the inner wall of the shell, the second magnet, the first annular piece, the elastic pressing assembly, the inner wall of the through hole of the valve body and the stopping piece form a second control chamber in a surrounding mode, the second control chamber is in liquid isolation from the first control chamber, 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 annular piece.

8. The fuel injector of claim 7, wherein at least a portion of the first passage at the opening is configured as a reduced diameter section, the first fuel flowing in the first passage creating a venturi effect at the reduced diameter section to allow the first fuel in the first control chamber to flow through the opening to the first passage.

9. The fuel injector of any of claims 1-4, wherein the housing comprises:

an upper housing, the first and second passages disposed within the upper housing;

10. The fuel injector of any one of claims 1-4, wherein an end of the housing distal from the first injection port is provided with an electrical connection assembly adapted to power the piezoelectric actuator.