CN-117365798-B - Dual fuel injector and engine

CN117365798BCN 117365798 BCN117365798 BCN 117365798BCN-117365798-B

Abstract

The invention discloses a dual fuel injector and an engine, the dual fuel injector, the ejector main body is provided with a first core chamber, a second core chamber, a first communication hole and a second communication hole. The first valve rod is arranged in the first core cavity, the first guide part of the first valve rod divides the first core cavity into a first pressure cavity and a second low pressure cavity, the first feeding channel is communicated with the first low pressure cavity through the first pressure cavity, the first guide part is provided with a first runner communicated with the first pressure cavity and a second runner communicated with the second low pressure cavity, the second valve rod is arranged in the second core cavity, the second guide part of the second valve rod divides the second core cavity into a second pressure cavity and a third low pressure cavity, the second feeding channel is communicated with the third low pressure cavity, the first communication hole and the second communication hole are both communicated with the second pressure cavity, the first communication hole can be communicated with the first runner, and the second communication hole can be communicated with the second runner. The dual fuel injector does not have mixed materials, and the actual working condition pressure range of the first fuel is larger.

Inventors

CHEN LIPING
YANG DIANYONG
CHEN NAN
WU XIAOXIAO
ZHOU TINGBO
XU YALEI

Assignees

一汽解放汽车有限公司

Dates

Publication Date: 20260508
Application Date: 20231115

Claims (11)

1. A dual fuel injector comprising an injector body (1) and a control valve assembly (2), the injector body (1) being provided with a first feed channel (11), a second feed channel (12), a first low pressure chamber (13), a first nozzle (511) and a second nozzle (521), the first feed channel (11) being adapted to feed fuel, the first feed channel (11) being adapted to communicate with the first low pressure chamber (13) and the first nozzle (511), the second feed channel (12) being adapted to communicate with the second nozzle (521), the control valve assembly (2) being adapted to selectively shut off or communicate the communication of the first feed channel (11) with the first nozzle (511), and to shut off or communicate the communication of the second feed channel (12) with the second nozzle (521), characterized in that it further comprises: A first core cavity (14) and a first valve rod (31), wherein the first core cavity (14) is formed in the injector main body (1), the first valve rod (31) is movably arranged in the first core cavity (14), the first valve rod (31) comprises a first guide part (311) and a first main body part (312), the shaft diameter of the first guide part (311) is larger than that of the first main body part (312), the first guide part (311) divides the first core cavity (14) into a first pressure cavity (141) and a second low pressure cavity (142) which are not communicated with each other, the first feeding channel (11) is communicated with the first low pressure cavity (13) through the first pressure cavity (141), the first guide part (311) is provided with a first flow channel (313) communicated with the first pressure cavity (141), and a second flow channel (314) communicated with the second low pressure cavity (142), and the first flow channel (313) is not communicated with the second flow channel (314); The second core cavity (15) is formed in the ejector main body (1) and is arranged with the first core cavity (14) at intervals, the second valve rod (32) is movably arranged in the second core cavity (15), the second valve rod (32) comprises a second guide part (321) and a second main body part (322), the second guide part (321) divides the second core cavity (15) into a second pressure cavity (151) and a third low pressure cavity (152) which are not communicated, and the second feeding channel (12) is communicated with the third low pressure cavity (152); A first communication hole (161) and a second communication hole (162), wherein the first communication hole (161) and the second communication hole (162) are both opened on the ejector main body (1) and are both communicated with the second pressure cavity (151), the first communication hole (161) can be communicated with the first flow channel (313), and the second communication hole (162) can be communicated with the second flow channel (314); In the closed state of the dual fuel injector, the control valve assembly (2) cuts off the communication between the first pressure chamber (141) and the first low pressure chamber (13), the first feed channel (11), the first pressure chamber (141), the first flow channel (313), the first communication hole (161) and the second pressure chamber (151) are communicated, the second communication hole (162) is disconnected from the second flow channel (314), the oil pressure of the first pressure chamber (141) drives the first valve rod (31) to cut off the communication between the first feed channel (11) and the first nozzle (511), the oil pressure of the second pressure chamber (151) drives the second valve rod (32) to cut off the communication between the second feed channel (12) and the second nozzle (521), and in the open state of the dual fuel injector, the control valve assembly (2) communicates the first pressure chamber (141) with the first low pressure chamber (13), the first communication hole (161) and the second communication hole (314) are disconnected from the first flow channel (313), the second communication hole (142) and the second flow channel (521).
2. The dual fuel injector as claimed in claim 1, characterized in that the first flow passage (313) includes a first oil hole (3131) and a second oil hole (3132), the first oil hole (3131) extends along a direction from the first pressure chamber (141) to the first low pressure chamber (13), one end of the first oil hole (3131) is communicated with the first pressure chamber (141), the other end of the first oil hole (3131) is communicated with the second oil hole (3132), the second oil hole (3132) extends along a direction from the first pressure chamber (141) to the second pressure chamber (151), and in a closed state of the dual fuel injector, one end of the second oil hole (3132) is communicated with the first communication hole (161).
3. The dual fuel injector of claim 2, characterized in that the second flow passage (314) includes a third oil hole (3141) and a fourth oil hole (3142), the third oil hole (3141) is spaced from the second oil hole (3132) along the direction from the first pressure chamber (141) to the second low pressure chamber (142), and is located near one end of the second low pressure chamber (142), one end of the fourth oil hole (3142) is communicated with the third oil hole (3141), the other end is communicated with the second low pressure chamber (142), and in the open state of the dual fuel injector, one end of the third oil hole (3141) is communicated with the second communication hole (162).
4. A dual fuel injector as claimed in claim 1, characterized in that the second guide portion (321) comprises at least two guide shaft sections (3211), a connecting shaft section (3212) with a shaft diameter smaller than that of the guide shaft sections (3211) is connected between two adjacent guide shaft sections (3211), and the inner walls of the adjacent guide shaft sections (3211), the connecting shaft section (3212) and the second core cavity (15) are jointly enclosed to form a fourth low pressure cavity (153).
5. A dual fuel injector as claimed in claim 1, characterized in that a first return spring (41) is provided in the third low pressure chamber (152), the second body portion (322) is provided with a first abutment shaft section (3221), one end of the first abutment shaft section (3221) is connected with the first return spring (41), and in the open state of the dual fuel injector, the elastic force of the first return spring (41) can drive the second body portion (322) to move towards one end of the second pressure chamber (151) so as to communicate the second feed channel (12) with the second nozzle (521).
6. The dual fuel injector as claimed in claim 5, characterized in that the second guide portion (321) and the second main body portion (322) are formed separately, an end of the first abutting shaft section (3221) away from the first return spring (41) abuts against the second guide portion (321), a projection shape of the first abutting shaft section (3221) is elliptical along an axial direction of the first abutting shaft section (3221), a shaft diameter large end of the first abutting shaft section (3221) is in clearance fit with the third low pressure chamber (152), and a shaft diameter small end of the first abutting shaft section (3221) and an inner wall of the third low pressure chamber (152) form a fuel flow passage.
7. A dual fuel injector as claimed in claim 1, further comprising a nozzle assembly, the nozzle assembly comprising a first nozzle (51) and a second nozzle (52), the first nozzle (51) being sleeved on one end of the first valve stem (31) extending out of the first core cavity (14), a first injection channel (512) being formed between an inner wall of the first nozzle (51) and an outer wall of the first valve stem (31), the first nozzle (511) being provided on the first nozzle (51) and being in communication with one end of the first injection channel (512), the first nozzle (51) being provided with a first discharge channel (513), one end of the first discharge channel (513) being communicable with the first feed channel (11), the other end of the first discharge channel (513) being communicable with the other end of the first injection channel (512); The second nozzle (52) is sleeved on the first nozzle (51), a second injection channel (522) is formed between the inner wall of the second nozzle (52) and the outer wall of the first nozzle (51), the second nozzle (521) is arranged on the second nozzle (52) and is communicated with one end of the second injection channel (522), the first nozzle (51) is further provided with a second discharging channel (514), one end of the second discharging channel (514) can be communicated with the third low-pressure cavity (152), and the other end of the second discharging channel (514) is communicated with the other end of the second injection channel (522).
8. A dual fuel injector as claimed in claim 7, characterized in that the outer wall of the end of the second body portion (322) remote from the second pressure chamber (151) is provided with a first inclined surface (3222) in the circumferential direction, the inner wall of the end of the second discharge channel (514) communicating with the third low pressure chamber (152) is provided with a second inclined surface (5141) in the circumferential direction, and in the closed state of the dual fuel injector, the first inclined surface (3222) is fitted to the second inclined surface (5141) so as to cut off the communication between the third low pressure chamber (152) and the second discharge channel (514).
9. A dual fuel injector as claimed in any one of claims 1-8, characterized in that a valve plate (6) is provided in the first low pressure chamber (13), an oil through hole (61) and a communication channel (62) are provided in the valve plate (6), one end of the oil through hole (61) is communicated with the first pressure chamber (141), the other end of the oil through hole (61) can be selectively blocked or communicated by the control valve assembly (2), and the first feed channel (11) is communicated with the first pressure chamber (141) through the communication channel (62).
10. The dual fuel injector of claim 9, characterized in that the control valve assembly (2) comprises an electromagnet (21), an armature (22), a needle valve (23) and a sealing ball (24), the armature (22) is magnetically attracted to the electromagnet (21), the needle valve (23) is disposed on a side of the armature (22) away from the electromagnet (21), the sealing ball (24) is disposed on an end of the needle valve (23) away from the armature (22), and the sealing ball (24) is capable of sealing an end of the oil hole (61) away from the first pressure chamber (141).
11. An engine comprising a dual fuel injector as claimed in any one of claims 1 to 10.

Description

Dual fuel injector and engine Technical Field The invention relates to the technical field of engines, in particular to a dual-fuel injector and an engine. Background An engine is a machine capable of converting other forms of energy into mechanical energy, and is widely used in various mechanical devices. As one of many engine types, a dual fuel engine capable of simultaneously combusting two fuels has a wide application market, in which a dual fuel injector is a core component of the dual fuel engine, and combustion is performed by providing two fuel passages on the injector and injecting the two fuels into a combustion chamber of the engine. In the existing dual fuel injector, two core cavities, two valve cores, two feeding channels, two nozzles and one electromagnetic valve control assembly are arranged in the injector main body, so that injection of two fuels is simultaneously controlled by the electromagnetic valve control assembly, the whole structure of the engine is more compact, the arrangement of the engine is facilitated, and the manufacturing cost is saved. The dual fuel injector described above still has some problems. Specifically, since the first core cavity and the second oil passage of the injector body are communicated in both the closed state and the open state of the dual-fuel injector, when the oil inlet pressure of the first feed channel is too high, the oil inlet pressure can still be transmitted to the push rod through the first core cavity and the second oil passage, so that the pressure of the second feed channel and the elastic force of the first return spring can not push the push rod open or completely push the push rod, and finally the second fuel can not be normally sprayed out of the second nozzle, therefore, in order to ensure that the second fuel can be normally sprayed, the dual-fuel injector has higher requirements on the oil inlet pressure of the first feed channel, so that the oil injection pressure of the first fuel is limited, and the actual working condition pressure range of the first fuel is smaller. In addition, when the dual fuel injector is in an open state, the fuel oil of the second oil duct cannot be discharged or is completely discharged, so that a small amount of fuel oil enters the second discharging channel through a gap between the guide hole and the push rod, and is further mixed with the second fuel oil and then is sprayed out of the second nozzle, and the engine is abnormal in operation. Disclosure of Invention The invention aims to provide a dual-fuel injector and an engine, which are used for solving the problems that the prior dual-fuel injector has higher requirement on the oil inlet pressure of a first feeding channel, so that the oil injection pressure of first fuel is limited, the actual working condition pressure range of the first fuel is smaller, and the fuel oil of a second oil duct possibly enters a second discharging channel to be mixed with the first fuel and then is sprayed out of a second nozzle together, so that the engine works abnormally. To achieve the purpose, the invention adopts the following technical scheme: A dual fuel injector comprising an injector body and a control valve assembly, the injector body defining a first feed passage, a second feed passage, a first low pressure chamber, a first orifice, and a second orifice, the first feed passage being configured to admit fuel, the first feed passage being configured to communicate with the first low pressure chamber and the first orifice, the second feed passage being configured to communicate with the second orifice, the control valve assembly being configured to selectively block or communicate communication between the first feed passage and the first orifice, and to block or communicate communication between the second feed passage and the second orifice, further comprising: The first core cavity is formed in the ejector main body, the first valve rod is movably arranged in the first core cavity, the first valve rod comprises a first guide part and a first main body part, the shaft diameter of the first guide part is larger than that of the first main body part, the first guide part divides the first core cavity into a first pressure cavity and a second low pressure cavity which are not communicated with each other, the first feeding channel is communicated with the first low pressure cavity through the first pressure cavity, a first runner communicated with the first pressure cavity and a second runner communicated with the second low pressure cavity are formed in the first guide part, and the first runner is not communicated with the second runner; The second core cavity is formed in the ejector main body and is arranged at intervals with the first core cavity, the second valve rod is movably arranged in the second core cavity, the second valve rod comprises a second guide part and a second main body part, the second guide part divides the second core cavity into a sec