DE112013004803T5 - Fuel injection valve - Google Patents

Abstract

A fuel injection valve, which has provided therein: a central fuel passage (49) which is connected to a fuel supply unit in the central portion of a fixed core (5) and a movable core (12); a valve body (13) formed in a hollow cylindrical shape; an inner fuel passage (56) in the interior of the valve body (13), which is connected to a nozzle hole (9) when the valve body (13) is open; and a vertical groove (54) on the outer circumference of a connecting rod (14) which linearly connects the central fuel passage (49) with the inner fuel passage (56). As a result, a fuel injection valve can be provided in which the flow path resistance between the central fuel passage and the nozzle hole is reduced as much as possible, and the fuel injection amount can be increased without the opening stroke of the valve body or the time that the valve body is open to raise.

Description

TECHNICAL AREA

The present invention relates to an improvement of a fuel injection valve comprising a nozzle member having a valve seat and a nozzle hole, a tubular valve housing, which is provided at a rear end of the nozzle member, a fixed core which is connected to a rear end of the Valve housing is provided, a valve assembly which is formed of a valve body which opens and closes the nozzle hole in cooperation with the valve seat, a movable core, which faces an attraction surface at a front end of the fixed core, and a connecting rod which the valve body and the movable core connects, a return spring which is provided in a compressed state between the fixed core and the valve assembly and which urges the valve body in a valve closing direction, and a coil which is arranged so as to the fixed Ke and which, when energized, causes the movable core to be attracted to the solid core by a generated magnetic force to open the valve body.

TECHNICAL BACKGROUND

Such a fuel injection valve is already known as disclosed in the following Patent Document 1.

STATE OF THE ART DOCUMENTS

PATENT DOCUMENTS

• Patent Document 1: Japanese Patent Application Laid-open No. 2006-77777

OVERVIEW OF THE INVENTION

PROBLEMS TO BE SOLVED BY THE INVENTION

In such a fuel injection valve, at the time of valve opening from the valve body, fuel moves from a middle fuel passage provided in a central part of a fixed core / movable core to a fuel chamber on the inside of a valve housing via a side hole of the movable one Kern, passes through an outer fuel passage, which is defined between the valve housing and the valve body, and is then injected by means of a nozzle hole. Therefore, there are a plurality of bends in a fuel flow path from the central fuel passage to the nozzle hole, causing a flow path resistance, and when there is a demand for an increase in the injected fuel amount along with an increase in the output of an engine, an increase in the Valve opening strokes and the valve opening time of the valve body inevitable. However, this is undesirable because not only does the capacity of a coil increase, thus increasing the size of the fuel injector, but also the power consumption from the coil increases.

The present invention has been made in view of such circumstances, and an object thereof is to provide a fuel injection valve for which the flow path resistance between a central fuel passage and a nozzle hole is reduced as much as possible so as to allow the injected fuel amount to be increased without increasing the valve opening stroke and the valve opening time of the valve body.

MEANS OF SOLVING THE PROBLEMS

In order to achieve the above object, according to a first aspect of the present invention, there is provided a fuel injection valve comprising a nozzle member having a valve seat and a nozzle hole, a tubular valve housing provided at a rear end of the nozzle member, a fixed core, which is provided at a rear end of the valve housing, a valve assembly which is formed by a valve body which in cooperation with the valve seat opens and closes the nozzle hole, a movable core which faces an attraction surface at a front end of the fixed core and a connecting rod connecting the valve body and the movable core, a return spring which is provided in a compressed state between the fixed core and the valve assembly and which urges the valve body in a valve closing direction, and a spool which is arranged to surround the solid core and which, when energized, causes the movable core to be attracted to the solid core by a generated magnetic force to open the valve body, characterized in that a middle one A fuel passage communicating with a fuel supply part is provided at central parts of the fixed core and the movable core, whereas an inner fuel passage communicating with the nozzle hole at the time of valve opening from the valve body is located in an interior of the valve body is provided, which is formed as a hollow cylindrical shape, and a longitudinal groove is provided on an outer periphery of the connecting rod, wherein the longitudinal groove provides a linear connection between the central fuel passage and the inner fuel passage.

Further, according to a second aspect of the present invention, in addition to the first aspect, a fuel chamber is defined between the valve housing and the connecting rod, the longitudinal groove opens into the fuel chamber, an outer fuel passage is defined between the valve housing and the valve body, the outer fuel passage is is in communication with the nozzle hole while being parallel to the inner fuel chamber at the time of valve opening from the valve body, and a cutout providing communication between the fuel chamber and the outer fuel passage is provided in the valve body.

EFFECTS OF THE INVENTION

According to the first aspect of the present invention, the middle fuel passage communicating with the fuel supply part is provided in the central parts of the fixed core and the movable core, whereas the valve body is formed in the hollow cylindrical shape and the inner fuel passage is is provided on the inner side thereof, the longitudinal groove which provides a linear connection between the central fuel passage and the inner fuel passage is provided on the outer periphery of the connecting rod, the fuel flow path, which connects the central fuel passage of the fixed core and the movable core and the inner fuel passage of the valve body for it, is linear and has a low resistance due to the longitudinal groove of the connecting rod, and therefore it is possible I increase the amount of fuel injected from the nozzle hole without increasing the valve opening stroke and the valve opening time of the valve body to allow it to meet the demand for increased output of an engine. Further, since it is not necessary to increase the valve opening stroke and the valve opening time of the valve body, it is possible to avoid any increase in the dimensions of the spool and hence the fuel injection valve, and it is also possible to increase any of the energy consumption from the spool suppress.

According to the second aspect of the present invention, since the fuel chamber into which the longitudinal groove opens is defined between the valve housing and the connecting rod, the outer fuel passage communicating with the nozzle hole while being parallel to the inner fuel passage at the time valve opening of the valve body defined between the valve housing and the valve body, and the cutout providing communication between the fuel chamber and the outer fuel passage is provided in the valve body, the fuel flow path around the valve body is increased by the inner and outer fuel passages which are parallel to each other, and the fuel flow path connecting the central fuel passage and the nozzle hole therefor still has a lower resistance so as to allow the amount of fuel injected is further increased.

BRIEF DESCRIPTION OF THE DRAWINGS

1 FIG. 12 is a vertical sectional view of a gaseous fuel injection valve related to an embodiment of the present invention. FIG. First Embodiment

2 is an enlarged view of a part 2 in 1 , (Which shows a valve opening state) (First Embodiment)

3 is a sectional view taken along a line 3-3 in 2 , First Embodiment

4 is an exploded perspective view of a valve assembly in 2 , First Embodiment

LIST OF REFERENCE NUMBERS

I

Fuel injector (gaseous fuel injector)

2

nozzle member

3

valve housing

5

solid core

7

valve seat

9

nozzle hole

10

valve assembly

12

movable core

13

valve body

14

connecting rod

22

Kitchen sink

33

Return spring

49

medium fuel passage

50

neckline

54

longitudinal groove

55

Fuel chamber

56

internal fuel passage

57

outer fuel passage

MODES FOR CARRYING OUT THE INVENTION

Modes for carrying out the present invention will be explained below with reference to the accompanying drawings.

With respect to the injection valve of the present invention, the nozzle member side is referred to as the front side, and the fuel inlet pipe part side is referred to as the back side.

FIRST EMBODIMENT

First up 1 and 2 Referring to FIG. 1, a front end portion of a gaseous fuel injection valve I is inserted into a mounting hole Ea provided in a pipe wall of an intake pipe E of an engine and injecting gaseous fuel into the intake pipe E at the time of an engine intake stroke. A valve body 1 of this injection valve I is formed of a cap-shaped nozzle member 2 , a hollow cylindrical valve body 3 which is made of a magnetic material, the front end part thereof in an inner peripheral surface of the nozzle member 2 is inserted and connected to this by welding, etc., a solid core 5 which is integral with the rear end of the valve housing 3 by means of a non-magnetic cylindrical body 4 is connected, and a hollow cylindrical fuel inlet pipe 6 which is integral with the rear end of the fixed core 5 is provided connected. The front end part of the solid core 5 stands in the non-magnetic cylindrical body 4 in that the front end surface of the front end portion as an attraction surface 5a serves.

On the nozzle element 2 are a flat valve seat 7 and a plurality of nozzle holes 9 provided, which on a predetermined circumference C (see 3 ) from the valve seat 7 are arranged.

In a central part of the solid core 5 are a back feather reception hole 19 and a bracket press-fit hole 18 provided with the rear end of the rear spring receiving hole 19 is connected and has a larger diameter than that of it, and in an inner peripheral surface of the bracket-Einpressloch 18 Pressed and fixed to this is a tubular spring holder 36 which has a hollow section 36a Has. A long straight slot 37 is in the spring holder 36 provided what allows the spring retainer 36 is elastically compressed, and the outer diameter of the spring holder 36 is set to be larger in the free state than the inner diameter of the bracket press-fit hole 18 is while a game for a press fit in the bracket press-fit hole 18 is taken into account. A front end surface of the spring holder 36 forms a rear spring seat 35 ,

A hollow section 6a from the large diameter fuel inlet pipe 6 is at the rear end of the bracket press-fit hole 18 in conjunction and a fuel filter 38 is in an inlet of the fuel inlet pipe 6 used.

As in 2 to 4 As shown, an inner peripheral surface of the valve housing is used 3 as a sliding guide surface 3a and a valve assembly 10 is in the sliding guide surface 3a used. The valve arrangement 10 consists of a cylindrical movable core 12 , which is slidable in the Gleitführungsfläche 3a is inserted and the rear end surface of the attraction surface 5a at the front end of the fixed core 5 opposite, a valve body 13 which the nozzle holes 9 in cooperation with the valve seat 7 opens and closes, and a small diameter connecting rod 14 which is the moving core 12 and the valve body 13 connects and has a smaller diameter than this. A predetermined gap, which the Ventilöffnungshub of the valve body 13 is between opposite surfaces of the solid core 5 and the moving core 12 adjusted when the valve body 13 on the valve seat 7 seated.

The mobile core 12 has a front spring receiving hole in its central part 30 which is coaxial with the rear spring receiving hole 19 from the solid core 5 is arranged, and has at its front end a connecting pipe section 12a ,

The valve body 13 has a generally hollow cylindrical shape and is of an annular valve portion 13a formed, which the valve seat 7 opposite, and a connecting pipe section 13b which is integral with the rear end of the valve portion 13a is connected, wherein the valve portion 13a from the valve seat 7 is dissolved or on the valve seat 7 sits up, so the nozzle holes 9 to open and close.

Furthermore, the connecting pipe section has 13b on its outer periphery a flange-shaped journal portion 13b1 , which is slidable in the Gleitführungsfläche 3a is used. In the connecting pipe section 13b are a plurality of cutouts 50 provided opening on an inner peripheral surface, an outer peripheral surface and a rear end surface thereof.

The connecting rod 14 has a symmetrical shape in the longitudinal direction and includes a pair of front and rear cylindrical connecting end portions 14a and 14a and one small diameter bar section 14b , which provides an integral connection between the connection end sections 14a and 14a provides. A connection end section 14a is in an inner circumferential surface of the connecting pipe section 12a from the moving core 12 inserted and connected thereto by welding, etc., and the other connecting pipe section 14a is in an inner circumferential surface of the connecting pipe section 13b from the valve body 13 used and connected to it by welding and so on. In this way, these are three, ie the moving core 12 , the connecting rod 14 and the valve body 13 integrally connected with each other.

At the front and rear connection end sections 14a from the connecting rod 14 are a circular recess part 51 opening on an end face thereof and a tapered guide projection 53 , which from the bottom of the recess part 51 projected, provided. Further, on the outer periphery of the rod portion 14b a plurality of longitudinal grooves 54 provided, which extend along the entire length, wherein each longitudinal groove 54 at each of the front and rear connection end portions 14a a slot without a groove bottom is and with the recess part 51 communicates.

A part of a rear end surface of the rear connection end portion 14a from the connecting rod 14 , which in the connecting pipe section 12a from the moving core 12 is inserted, forms an annular front spring seat 34 leading to the front spring receiving hole 30 from the moving core 12 has. Further, the front connection end portion 14a and the connecting pipe section 13b from the valve body 13 assembled in such a way that the phases of the cutout 50 and the longitudinal groove 54 agree with each other.

The hollow section 36a from the spring holder 36 , the rear spring-receiving hole 19 and the front spring receiving hole 30 form a medium fuel passage 49 passing through central parts of the solid core 5 and the moving core 12 extends and with the interior of the fuel inlet pipe 6 communicates, and the longitudinal groove 54 and the recess part 51 from the rear connection end portion 14a from the connecting rod 14 open in the middle fuel passage 49 , Further, a hollow part is used by the valve portion 13a as an internal fuel passage 56 and when the valve section 13a from the valve seat 7 is solved, stands the inner fuel passage 56 with the nozzle holes 9 in connection. The longitudinal groove 54 and the recess part 51 from the front connection end portion 14a from the connecting rod 14 open in the inner fuel passage 56 , The middle fuel passage 49 stands with the inner fuel passage 56 by means of the plurality of longitudinal grooves 54 from the connecting rod 14 linear or straight in connection.

A fuel chamber 55 is between the connecting rod 14 and the inner peripheral surface of the valve housing 3 defined opposite to an outer peripheral surface thereof, the longitudinal grooves 54 from the connecting rod 14 open in the fuel chamber 55 , and every clipping 50 has a floor 50a , which is the fuel chamber 55 in the axial direction opposite.

Further, on the inner peripheral surface of the valve housing 3 an enlarged diameter section 3b provided, which a portion of the valve body 13 which is further forward than the journal portion 13b1 is, and between the inner peripheral surface of the enlarged diameter portion 3b and the valve body 13 is an outer fuel passage 57 defined, which with the cutouts 50 from the valve body 13 communicates. This outer fuel passage 57 stands with nozzle holes 9 in contact while going to the inner fuel passage 56 is parallel when the valve section 13a from the valve seat 7 is solved.

Again on 1 Referring to a return spring 33 , which in the rear and front spring receiving holes 19 and 30 is arranged, in a compressed state with a predetermined set load between the front spring seat 34 and the rear spring seat 35 provided and the set load urges the valve body 13 in the valve closing direction, ie, in the direction in which it rests on the valve seat 7 seated. The set load is set by the depth to which the spring retainer 36 into the bracket press-fit hole 18 is pressed.

A coil arrangement 20 is disposed so as to surround a portion extending from a portion of the valve housing 3 from where the moving core 12 inserted into it, to the solid core 5 extends. This coil arrangement 20 is formed of a bobbin 21 which surrounds the outer peripheries of the valve housing 3 , the non-magnetic cylindrical body 4 and the solid core 5 around and a coil 22 which surround the outer circumference of the bobbin 21 is wound around, and a bobbin case 23 which is made of a magnetic material is on the outer periphery of the coil assembly 20 arranged to cover them.

A yoke flange 24 is integral with the solid core 5 trained, the yoke flange 24 is from an outer peripheral surface of the fixed core 5 and supports a rear end surface of the bobbin 21 from and a rear end part of the coil housing 23 is on an outer circumferential surface of the yoke flange 24 appropriate. Further, integrally formed with a front end part of the coil housing 23 an annular end wall 23a , which at a front end surface of the bobbin 21 abuts, and a cylindrical section 23b which is from the inner peripheral end of the annular end wall 23a projects forward and on the outer peripheral surface of the valve housing 3 attached and secured. In this way, the coil arrangement 20 and the coil housing 23 on the valve body 1 appropriate. A resin / synthetic resin molding layer 26 is on outer peripheral surfaces of the coil housing 23 and the fuel inlet pipe 6 designed so that it covers continuously, and a coupler 28 is integral with the resin / synthetic resin molding layer 26 shaped so as to protrude to a side, wherein the coupler 28 one with the coil 22 connected power supply connection 27 holds.

A pair of front and rear flanges 41 and 42 which has an annular front sealing groove 40 are at the outer periphery of the nozzle member 2 formed and a sealing element 43 is in the front seal groove 40 used, wherein the sealing element 43 a close contact with an inner circumferential surface of the mounting hole Ea from the engine inlet pipe E to the nozzle member 2 produces when the nozzle element 2 is inserted therein.

Further, an annular rear seal groove 45 on the outer periphery of a rear end part of the fuel inlet pipe 6 defined, and a sealing element 47 , which is in close contact with an inner peripheral surface of a fuel distribution pipe D, which is on the rear end part of the fuel inlet pipe 6 is attached, is in the rear seal groove 45 used.

The operation of the embodiment will now be explained.

When the coil 22 is in a de-energized state, the valve assembly 10 , as in 1 shown by the set load of the return spring 33 pressed forward, leaving the valve body 13 on the valve seat 7 is put on.

If the coil 22 is supplied with energy by passing an electric current through it, the resulting magnetic flux flows through the coil case in order 23 , the valve body 3 , the mobile core 12 , the solid core 5 and the coil housing 23 , as in 2 shown, the valve assembly 10 against the set load of the return spring 33 by the action of a magnetic force which exists between the solid core 5 and the moving core 12 is generated, to the attraction area 5a from the solid core 5 used and the valve body 13 gets from the valve seat 7 solved so the nozzle holes 9 to open.

If the nozzle holes 9 open, gaseous fuel which has been supplied from an unillustrated gaseous fuel tank to the fuel distribution pipe D flows into the fuel inlet pipe 6 , is through the fuel filter 38 filtered, passes through the middle fuel passage 49 within the solid core 5 and the mobile core 12 and then flows into the longitudinal groove 54 and the rear notch part 51 from the connecting rod 14 into it. Gaseous fuel entering the longitudinal groove 54 has flowed, becomes linear through the longitudinal groove 54 passed, reaches the inner fuel passage 56 from the valve body 13 and enters the engine intake pipe E through the plurality of nozzle holes 9 injected. In this way, the fuel flow path, which is the mean fuel passage 49 from the solid core 5 and the moving core 12 with the internal fuel passage 56 from the valve body 13 connects, straight and has a low resistance due to the longitudinal groove 54 from the connecting rod 14 , Therefore, it is possible that of the nozzle hole 9 to increase the injected fuel amount without the valve opening stroke and the valve opening time of the valve body 13 so as to enable the need for increased output of an engine to be met. Further, since it is unnecessary to increase the valve opening stroke and the valve opening time of the valve body, it is possible to avoid any increase in the size of the spool and hence the fuel injection valve, and it is also possible to suppress any increase in power consumption from the spool ,

On the other hand, due to the fact that the flow of gaseous fuel, which in the rear recess portion 51 has flowed in the radial direction through the conical guide projection 53 which is from the bottom of the recess part 51 protrudes, it is easily to the plurality of longitudinal grooves 54 from the connecting rod 14 and the fuel chamber 55 on the outer circumference of the connecting rod 14 Therefore, the gaseous fuel stagnates in the bottom part of the recess part 51 Not. Gaseous fuel extending from the recess portion 51 to the longitudinal groove 54 has increased the flow rate of gaseous fuel, which in the longitudinal groove 54 flows down. In this process, when gaseous fuel, which along the groove bottom of each longitudinal groove 54 flows down, the lower recess part 51 from the connecting rod 14 achieved, he is easily through the guide projection 53 which projects from the bottom thereof to the inner fuel passage 56 directed.

Furthermore, because the inner fuel passage 56 and the outer fuel passage 57 , which are parallel to each other and with the nozzle hole 9 in communication, on the inner periphery and the outer periphery of the valve body 13 are provided, the fuel flow path around the valve body 13 increased and the fuel flow path, which the average fuel passage 49 and connecting the nozzle hole still has less resistance so as to allow the injected amount of fuel to be slightly increased.

In addition, the valve body 13 , the moving core 12 and the connecting rod 14 which are attached to each other and connected to each other, manufactured individually and when each of them is made, it is possible to cut the cutout 50 in the valve body 13 easy to work with and the longitudinal groove 54 in the connecting rod 14 easy to work without interference from parts where the valve body 13 , the moving core 12 and the connecting rod 14 are joined together to improve productivity.

Further, because of the cutout 50 the ground 50a has which fuel, which from the fuel chamber 55 was obtained between the inner and outer fuel passages 56 and 57 Distributed, it is possible to fuel, which from the fuel chamber 55 in the neckline 50 has flowed through the ground 50a from the clipping 50 substantially uniform between the inner and outer fuel passages 56 and 57 divide.

The present invention is not limited to the above embodiments and can be modified in a variety of ways as long as the modifications do not depart from the spirit and scope thereof. For example, the present invention may be applied to a liquid fuel injection valve such as gasoline.

Claims (2)

Fuel injection valve, comprising a nozzle element ( 2 ), which has a valve seat ( 7 ) and a nozzle hole ( 9 ), a tubular valve housing ( 3 ) which is connected at a rear end of the nozzle element ( 2 ), a fixed core ( 5 ) which is connected at a rear end of the valve housing ( 3 ) is provided, a valve assembly ( 10 ), which is formed by a valve body ( 13 ), which the nozzle hole ( 9 ) in cooperation with the valve seat ( 7 ) opens and closes, a moving core ( 12 ), which is an attraction ( 5a ) at a front end of the fixed core ( 5 ) and a connecting rod ( 14 ), which the valve body ( 13 ) and the movable core ( 12 ), a return spring ( 33 ), which in a compressed state between the solid core ( 5 ) and the valve assembly ( 10 ) is provided and the valve body ( 13 ) urges in a valve closing direction, and a coil ( 22 ) which is arranged such that it forms the solid core ( 5 ) and which, when energized, causes the movable core to ( 12 ) by a generated magnetic force to the solid core ( 5 ) is attracted to the valve body ( 13 ), characterized in that a middle fuel passage ( 49 ), which communicates with a fuel supply part, in central parts of the solid core (FIG. 5 ) and the movable core ( 12 ), whereas an internal fuel passage ( 56 ), which with the nozzle hole ( 9 ) at the time of valve opening from the valve body ( 13 ) in an interior of the valve body ( 13 ) is provided, which is formed as a hollow cylindrical shape, and a longitudinal groove ( 54 ) on an outer periphery of the connecting rod ( 14 ) is provided, wherein the longitudinal groove ( 54 ) a linear connection between the middle fuel passage ( 49 ) and the internal fuel passage ( 56 ). Fuel injection valve according to claim 1, wherein a fuel chamber ( 55 ) between the valve housing ( 3 ) and the connecting rod ( 14 ), the longitudinal groove ( 54 ) into the fuel chamber ( 55 ), an outer fuel passage ( 57 ) between the valve housing ( 3 ) and the valve body ( 13 ), the outer fuel passage ( 57 ) communicates with the nozzle hole while being parallel to the inner fuel chamber ( 56 ) is, at the time of valve opening of the valve body ( 13 ), and a cutout, which a connection between the fuel chamber ( 55 ) and the outer fuel passage ( 57 ), in the valve body ( 13 ) is provided.

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