JP5982704B2 - Fuel injection valve - Google Patents

Description

The present invention includes a nozzle member having a valve seat and a nozzle hole, the cylindrical valve housing which is provided continuously to the rear end of the nozzle member, is accommodated within the valve housing, wherein in cooperation with the valve seat A valve assembly comprising a valve body for opening and closing the nozzle hole, a linkage connected to the rear end of the valve body, and a movable core connected to the rear end of the linkage , and a suction surface at the front end to the movable core A fixed core to be opposed, a return spring that is contracted between the fixed core and the valve assembly and biases the valve body in a valve closing direction, and is disposed so as to surround the fixed core, A coil that causes the movable core to be attracted to the fixed core by the generated magnetic force to open the valve body, and a central fuel passage that communicates with a fuel supply unit is provided at the center of the fixed core and the movable core, In addition, between the linkage and the valve housing, the middle A fuel injection valve that defines a fuel chamber that communicates with a fuel passage, and has an outer fuel passage that communicates the fuel chamber with the nozzle hole between the valve body and the valve housing when the valve body is opened. Regarding improvements.

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

JP 2006-77777 A

  In such a fuel injection valve, when the valve body is opened, the fuel moves from the central fuel passage provided in the center of the fixed core movable core to the fuel chamber inside the valve housing through the horizontal hole of the movable core, and The nozzle hole is injected through an outer fuel passage defined between the valve housing and the valve body. Therefore, there are multiple bends in the fuel flow path from the central fuel passage to the nozzle hole, and this becomes flow resistance, so if there is a demand for an increase in fuel injection amount due to higher engine output, It is necessary to set many valve opening strokes and valve opening times. However, doing so is not preferable because it causes not only an increase in the capacity of the coil and an increase in the size of the fuel injection valve, but also an increase in the power consumption of the coil.

  The present invention has been made in view of such circumstances, and it is possible to reduce the flow resistance between the central fuel passage and the nozzle hole as much as possible and to increase the fuel injection without increasing the valve opening stroke and the valve opening time. An object of the present invention is to provide the fuel injection valve capable of increasing the amount.

To achieve the above object, the present invention includes a nozzle member having a valve seat and a nozzle hole, a tubular valve housing which is provided continuously to the rear end of the nozzle member, is accommodated within the valve housing, said valve body for opening and closing the nozzle hole in cooperation with the valve seat, communicates rod which is connected to the rear end of the valve body, and a valve assembly consisting of the movable core which is connected to the rear end of the connecting rod, the front end A stationary core that faces the movable core, a return spring that is compressed between the stationary core and the valve assembly and biases the valve body in a valve closing direction, and surrounds the stationary core. And a coil that causes the movable core to be attracted to the fixed core by the generated magnetic force when energized to open the valve body, and a fuel supply unit is provided at the center of the fixed core and the movable core. There is a central fuel passage that communicates with the A fuel chamber communicating with the central fuel passage is defined between the valve housings, and an outer fuel passage communicating the fuel chamber with the nozzle hole between the valve body and the valve housing when the valve body is opened. The fuel injection valve is provided with a rear concave portion that opens to the central fuel passage and a rear notch that opens the rear concave portion to the fuel chamber at the rear end of the linkage. A body is formed in a hollow cylindrical shape, and an inner fuel passage communicating with the nozzle hole when the valve body is opened is provided on the inner side of the body, and a front concave portion opened to the inner fuel passage is formed at a front end portion of the joint. The first feature is that a front notch for opening the front recess to the fuel chamber is provided.

  According to the second aspect of the invention, in addition to the first feature, the depths of the rear and front notches are set equal to or deeper than the corresponding depths of the rear and front recesses. Features.

  Furthermore, in addition to the second feature, the present invention has a third feature that conical guide protrusions are formed on the bottom surfaces of the rear and front recesses.

  According to the first feature of the present invention, the rear end portion of the linkage is provided with a rear recess opening in the central fuel passage and a rear notch opening the rear recess into the fuel chamber. The fuel can flow smoothly from the central fuel passage to the fuel chamber through the rear recess and the rear notch, and the front recess that opens into the inner fuel passage of the valve body and the front recess By providing a front notch that opens to the fuel chamber, fuel can flow smoothly from the fuel chamber to the inner fuel passage through the rear notch and the rear recess, and further outside and inside the valve body, By providing the inner and outer fuel passages that communicate in parallel with the nozzle holes when the valve body is opened, the fuel flow path around the valve body can be expanded, which increases the valve opening stroke. Without increasing the fuel injection amount from the nozzle hole And obtained by, it is possible to meet higher output of the engine. In addition, since there is no need to increase the valve opening stroke and valve opening time, it is possible to avoid an increase in the size of the coil and hence the fuel injection valve, and also to suppress an increase in power consumption of the coil. .

  According to the second feature of the present invention, the depths of the rear and front notches are set equal to or deeper than the corresponding depths of the rear and front recesses. Therefore, the rear recess cooperates with the rear notch to flow fuel from the central fuel passage to the fuel chamber, and the front recess cooperates with the front notch. Thus, the flow of fuel from the fuel chamber to the inner fuel passage can be guided smoothly, and the amount of fuel injected from the nozzle hole can be increased more easily.

  According to the third aspect of the present invention, conical guide protrusions are formed on the bottom surfaces of the rear and front recesses, so that the flow of fuel from the central fuel passage to the fuel chamber and the inner fuel passage from the fuel chamber The flow of fuel to each can be guided more smoothly.

The longitudinal cross-sectional view of the injection valve for gas fuel which concerns on embodiment of this invention. FIG. 2 is an enlarged view of part 2 in FIG. 1 (however, the valve is open). FIG. FIG. 3 is an exploded perspective view of the valve assembly in FIG. 2.

  Embodiments of the present invention will be described below with reference to the accompanying drawings. In the injection valve of the present invention, the nozzle member side is referred to as the front, and the fuel inlet cylinder side is referred to as the rear.

  First, in FIG. 1 and FIG. 2, a gas fuel injection valve I has a front end portion attached to an attachment hole Ea provided in a pipe wall of an intake pipe E of the engine. Inject into. A valve body 1 of the injection valve I includes a cap-shaped nozzle member 2 and a hollow cylindrical valve made of a magnetic material that is joined by welding or the like by fitting the front end portion to the inner peripheral surface of the nozzle member 2. A housing 3, a fixed core 5 integrally connected to the rear end of the valve housing 3 via a nonmagnetic cylinder 4, and a hollow cylindrical fuel integrally connected to the rear end of the fixed core 5 It consists of an inlet tube 6. The fixed core 5 has a front end portion that has a front end surface as an attraction surface 5 a and is inserted into the nonmagnetic cylindrical body 4.

  The nozzle member 2 is provided with a flat valve seat 7 and a plurality of nozzle holes 9 arranged on a predetermined circumference C (see FIG. 3) in the valve seat 7.

  A central portion of the fixed core 5 is provided with a rear spring accommodating hole 19 and a retainer press-fitting hole 18 having a diameter larger than that of the rear spring accommodating hole 19, and an inner periphery of the retainer press-fitting hole 18. A pipe-like spring retainer 36 having a hollow portion 36a on the surface is press-fitted and fixed. The spring retainer 36 is provided with a single slit 37, whereby the spring retainer 36 can be elastically reduced in diameter, and the outer diameter of the spring retainer 36 has an allowance for press-fitting into the retainer press-fit hole 18. Considering this, the inner diameter of the retainer press-fitting hole 18 is set larger than the inner diameter in a free state. A rear spring seat 35 is constituted by the front end face of the spring retainer 36.

  A hollow portion 6a of the fuel inlet cylinder 6 having a larger diameter is connected to the rear end of the retainer press-fitting hole 18, and a fuel filter 38 is attached to the inlet of the fuel inlet cylinder 6.

As shown in FIGS. 2 to 4, the inner peripheral surface of the valve housing 3 is a sliding guide surface 3 a, and the valve assembly 10 accommodated in the valve housing 3 is fitted on the sliding guide surface 3 a. Is done. The valve assembly 10 is slidably fitted to the sliding guide surface 3 a and has a cylindrical movable core 12 whose rear end face is opposed to the suction surface 5 a at the front end of the fixed core 5, and the valve seat 7. a valve body 13 for opening and closing the nozzle holes 9, 9 ... to work, Ru is connected to the rear end of the valve body 13 so as to connected between the movable core 12 and the valve body 13, which the movable core 12, the valve body 13 than is composed of a small diameter communicating rod 14, the movable core 12 is connected to the rear end of the connecting rod 14. A predetermined gap corresponding to the valve opening stroke of the valve body 13 is set between the opposed surfaces of the fixed core 5 and the movable core 12 when the valve body 13 is seated on the valve seat 7.

  The movable core 12 has a front spring accommodating hole 30 aligned coaxially with the rear spring accommodating hole 19 of the fixed core 5 at the center thereof, and a connecting cylinder portion 12a at the front end thereof.

  The valve body 13 generally has a hollow cylindrical shape, and includes an annular valve portion 13a facing the valve seat 7 and a connecting cylinder portion 13b integrally connected to the rear end of the valve portion 13a. The part 13a opens and closes the nozzle holes 9, 9 ... by being separated from and seated on the valve seat 7.

  Further, the connecting cylinder portion 13b has a flange-like journal portion 13b1 on the outer periphery thereof that is slidably fitted to the sliding guide surface 3a. The connecting cylinder portion 13b is provided with a plurality of notches 50, 50,.

  The linkage 14 includes a pair of rear and front connection ends 14a and 14c arranged in the axial direction, and a flange 14b having a smaller diameter than the rear and front connection ends 14a and 14c. It has a symmetrical shape. The rear connection end portion 14a is fitted to the inner peripheral surface of the connection cylindrical portion 12a of the movable core 12 and connected by welding or the like, and the front connection end portion 14c is connected to the inner peripheral surface of the connection cylindrical portion 13b of the valve body 13. Fit and join by welding. In this way, the movable core 12, the linkage 14, and the valve body 13 are integrally coupled.

  The 14 rear and front connecting end portions 14a and 14c have circular rear and front concave portions 51a and 51b that open to the respective end surfaces, and the corresponding rear end and front concave portions 51a and 51b. , 14c open to the outer peripheral surface of each of the plurality of rear and front notches 52a, 52a... 52b, 52b. And are provided. Each rear part and front notch 52a, 52b are formed so that each depth may become equal to or deeper than the depth of the corresponding recessed part 51a, 51b.

  Further, on the outer periphery of the flange portion 14b, a plurality of longitudinal grooves 54, 54,... That communicate linearly between the rear and front notches 52a, 52b are provided. A part of the rear end surface of the rear connection end portion 14 a fitted to the connection cylinder portion 12 a of the movable core 12 constitutes an annular front spring seat 34 that faces the front spring accommodation hole 30 of the movable core 12. Further, the front connection end portion 14c and the connection cylinder portion 13b of the valve body 13 are fitted so that the phases of the notches 52b and 50 coincide with each other.

  The hollow portion 36 a, the rear spring accommodating hole 19, and the front spring accommodating hole 30 of the spring retainer 36 constitute a central fuel passage 49 that passes through the central portions of the fixed core 5 and the movable core 12 and communicates with the inside of the fuel inlet cylinder 6. In the central fuel passage 49, a rear recess 51a and a rear notch 52a are opened. The hollow portion of the valve portion 13a serves as an inner fuel passage 56, and communicates with the nozzle holes 9, 9 ... when the valve portion 13a is separated from the valve seat 7. In the inner fuel passage 56, the front recess 51b and the front notch 52b of the linkage 14 are opened.

  The vertical grooves 54, 54... Of the linkage 14 and the notches 50, 50... Of the valve body 13 open between the linkage 14 and the inner circumferential surface of the valve housing 3 facing the outer circumference. A chamber 55 is defined, and each notch 50 has a bottom surface 50a facing the fuel chamber 55 in the axial direction.

  The hollow portion of the valve portion 13a is an inner fuel passage 56, and communicates with the nozzle holes 9, 9 ... when the valve portion 13a is separated from the valve seat 7. In the inner fuel passage 56, a front recess 51b and front notches 52b, 52b,.

  An annular outer fuel passage 57 in which notches 50, 50... Of the valve body 13 are opened is defined between the valve body 13 and the valve housing 3 in front of the journal portion 13b1. At that time, the outer peripheral surface of the valve body 13 facing the outer fuel passage 57 is formed to have a smaller diameter than the journal portion 13b1, while the inner peripheral surface of the valve housing 3 facing the outer fuel passage 57 is An enlarged diameter portion 3b having a larger diameter than the journal portion 13b1 is provided. Accordingly, the outer fuel passage 57 is defined between the outer peripheral surface of the valve body 13 having a smaller diameter than the journal portion 13b1 and the enlarged diameter portion 3b of the inner peripheral surface of the valve housing 3 having a larger diameter than the journal portion 13b1. It will be of volume.

  In FIG. 1 again, a return spring 33 disposed in the rear and front spring accommodating holes 19 and 30 is contracted between the front spring seat 34 and the rear spring seat 35 with a predetermined set load. The load urges the valve body 13 in the valve closing direction, that is, in the seating direction on the valve seat 7. The set load is adjusted by the press-fitting depth of the spring retainer 36 into the retainer press-fitting hole 18.

  A coil assembly 20 is disposed from a region where the movable core 12 of the valve housing 3 is fitted to the fixed core 5 and surrounding them. The coil assembly 20 includes a valve housing 3, a bobbin 21 fitted to the outer periphery of the nonmagnetic cylindrical body 4 and the fixed core 5, and a coil 22 wound around the outer periphery of the bobbin 21. A magnetic coil housing 23 is disposed on the outer periphery of the solid 20 to cover it.

  The fixed core 5 is integrally formed with a yoke flange 24 that protrudes from the outer peripheral surface and supports the rear end surface of the bobbin 21, and the rear end portion of the coil housing 23 is fitted to the outer peripheral surface of the yoke flange 24. Further, an annular end wall 23a abutting against the front end surface of the bobbin 21 and a forward projection from the inner peripheral end of the annular end wall 23a are fitted and fixed to the outer peripheral surface of the valve housing 3 at the front end portion of the coil housing 23. The cylindrical portion 23b is integrally formed. Thus, the coil assembly 20 and the coil housing 23 are attached to the valve body 1. A resin mold layer 26 that continuously covers them is formed on the outer peripheral surfaces of the coil housing 23 and the fuel inlet cylinder 6, and a coupler 28 that projects to one side is integrally formed on the resin mold layer 26. The molded coupler 28 holds a current-carrying terminal 27 connected to the coil 22.

  A pair of front and rear flanges 41 and 42 that define an annular front seal groove 40 are formed on the outer periphery of the nozzle member 2, and the nozzle member 2 is attached to a mounting hole for an intake pipe E of the engine in the front seal groove 40. When inserted into Ea, a seal member 43 that is in close contact with the inner peripheral surface thereof is mounted.

  An annular rear seal groove 45 is defined on the outer periphery of the rear end portion of the fuel inlet tube 6, and the inner periphery of the fuel distribution pipe D fitted to the rear end portion of the fuel inlet tube 6 is formed in the rear seal groove 45. A seal member 47 that is in close contact with the surface is attached.

  Next, the operation of this embodiment will be described.

  In the demagnetized state of the coil 22, as shown in FIG. 1, the valve assembly 10 is pressed forward by the set load of the return spring 33, and the valve body 13 is seated on the valve seat 7.

  When the coil 22 is excited by energization, the magnetic flux generated by the coil 22 sequentially travels through the coil housing 23, the valve housing 3, the movable core 12, the fixed core 5, and the coil housing 23, and the magnetic force generated between the fixed core 5 and the movable core 12 As shown in FIG. 2, the valve assembly 10 is attracted to the suction surface 5 a of the fixed core 5 against the set load of the return spring 33, the valve body 13 is separated from the valve seat 7, and the nozzle holes 9, 9 …open.

  When the nozzle holes 9, 9... Are opened, the gas fuel sent from the gas fuel tank (not shown) to the fuel distribution pipe D flows into the fuel inlet cylinder 6 and is filtered by the fuel filter 38, and the central fuel passage 49 (spring retainer). After passing through the hollow portion 36a of 36, the rear spring accommodating hole 19 of the fixed core 5, and the front spring accommodating hole 30 of the movable core 12, it flows into the rear concave portion 51a of the linkage 14. The gas fuel flowing into the rear recess 51a is deflected in the radial direction by a conical guide projection 53a protruding from the bottom surface of the rear recess 51a, so that a plurality of rear notches 52a, 52a are smoothly supplied. Therefore, the gas fuel does not stagnate at the bottom of the rear recess 51a. The gas fuel moved from the rear recess 51a to the fuel chamber 55 in the valve housing 3 flows forward, and part of the fuel hits the bottom surfaces 50a of the plurality of notches 50, 50. The fuel flows into the inner and outer fuel passages 56 and 57 substantially equally, and the other fuel flows along the longitudinal grooves 54, 54... Of the linkage 14 and passes through the front notches 52b, 52b. It flows into the inner fuel passage 56 inside the portion 13a. At that time, the gas fuel flowing down the bottom surfaces of the longitudinal grooves 54, 54... Is guided by the lower conical guide protrusion 53 and can smoothly flow into the front recess 51b, and gas flows into the bottom of the front recess 51b. There is no fuel. In this way, the gas fuel that has been diverted from the fuel chamber 55 into the inner and outer fuel passages 56, 57 is injected into the intake pipe E of the engine through the plurality of nozzle holes 9, 9.

  As described above, the fuel chamber 55 on the outer periphery of the linkage 14 and the nozzle holes 9, 9... Therefore, the fuel flow path around the valve body 13 can be expanded, and the fuel injection amount from the nozzle hole 9 can be reduced without increasing the valve opening stroke and the valve opening time of the valve body 13. It can be easily increased to meet the higher engine output. Further, since it is not necessary to increase the valve opening stroke of the valve body 13, it is possible to avoid an increase in the size of the coil, and hence the injection valve I, and it is possible to suppress an increase in power consumption of the coil.

  In particular, the inner and outer fuel passages 56, 57 are fitted to the inner peripheral surface of the valve body 13, and the notches 50 provided at the rear end portion of the valve body 13 and opening to the inner peripheral surface, outer peripheral surface and rear end surface thereof. Since it communicates with the fuel chamber 55 in the valve housing 3 through the front notch 52b and the longitudinal groove 54 of the joint 14 to be joined together, it is not obstructed by the fitting portion of the valve body 13 and the joint 14 , The fuel can be smoothly diverted from the fuel chamber 55 to the inner and outer fuel passages 56 and 57. In addition, since the valve body 13 and the linkage 14 to be fitted to each other are individually manufactured, the notch 50 and the front notch 52b can be easily formed at the time of each processing, and productivity is increased. Can be increased.

  Further, the connecting cylinder portion 12a of the valve body 13 has a bowl-shaped journal portion 13b1 slidably fitted to the inner peripheral surface of the valve housing 3, so that the opening and closing posture of the valve body 13 can be stabilized. In addition, the notch 50 of the connecting cylinder portion 12a allows communication between the fuel chamber 55 and the outer fuel passage 57 without interference with the journal portion 13b1.

  Moreover, the outer fuel passage 57 is defined between the outer peripheral surface of the valve body 13 having a smaller diameter than the journal portion 13b1 and the enlarged diameter portion 3b of the inner peripheral surface of the valve housing 3 having a larger diameter than the journal portion 13b1. By increasing the volume of the outer fuel passage 57 and thus expanding the fuel flow path around the valve body 13, the amount of fuel injected from the nozzle hole 9 can be easily increased.

  The present invention is not limited to the embodiments described above, and various design changes can be made without departing from the scope of the invention. For example, the present invention can be applied to an injection valve for liquid fuel such as gasoline.

I ... Fuel injection valve (Injection valve for gas fuel)
2 ... Nozzle member 3 ... Valve housing 5 ... Fixed core 7 ... Valve seat 9 ... Nozzle hole 10 ... Valve assembly 12- ... movable core 13 ... valve element 14 ... linkage 22 ... coil 33 ... return spring 49 ... central fuel passage 51a ... rear recess 51b ... Front recess 52a ... rear notch 52b ... front notch 53a ... guide projection 53b ... guide projection 55 ... fuel chamber 56 ... inner fuel passage 57 ... Outer fuel passage

Claims (3)

A valve seat (7) and the nozzle member (2) having a nozzle hole (9), a cylindrical valve housing which is provided continuously to the rear end of the nozzle member (2) (3), wherein the valve housing (3) housed within the valve body which cooperates with the valve seat (7) for opening and closing the nozzle hole (9) (13), communicating rod which is connected to the rear end of the valve body (13) (14), In addition, a valve assembly (10) comprising a movable core (12) connected to the rear end of the linkage (14), and a fixed core (5) with the suction surface (5a) at the front end facing the movable core (12). ), A return spring (33) that is contracted between the fixed core (5) and the valve assembly (10) to urge the valve body (13) in the valve closing direction, and the fixed core (5) The movable core (12) is attracted to the fixed core (5) by the generated magnetic force when energized. And a coil (22) for opening the valve body (13), and a central fuel passage (49) communicating with the fuel supply section is provided at the center of the fixed core (5) and the movable core (12). Further, a fuel chamber (55) communicating with the central fuel passage (49) is defined between the linkage (14) and the valve housing (3), and the valve body (13) and the valve housing (3) are defined. ) During the opening of the valve body (13), the fuel injection valve provided with an outer fuel passage (57) communicating the fuel chamber (55) with the nozzle hole (9),
A rear recess (51a) that opens to the central fuel passage (49) and a rear notch that opens the rear recess (51a) to the fuel chamber (55) at the rear end of the linkage (14). (52a) is formed, and the valve body (13) is formed in a hollow cylindrical shape, and an inner fuel passage (56) communicated with the nozzle hole (9) when the valve body (13) is opened. At the front end of the linkage (14), and a front recess (51b) that opens to the inner fuel passage (56), and a front portion that opens the front recess (51b) to the fuel chamber (55). A fuel injection valve provided with a notch (52b). The fuel injection valve according to claim 1, wherein
The fuel injection valve characterized in that each depth of the rear and front notches (52a, 52b) is set equal to or deeper than the corresponding depth of the rear and front recesses (51a, 51b). . The fuel injection valve according to claim 2,
A fuel injection valve, wherein conical guide protrusions (53a, 53b) are formed on the bottom surfaces of the rear and front recesses (51a, 51b).

Images