JP6035647B2 - Fuel injection valve - Google Patents

Description

The present invention includes a nozzle member having a nozzle hole and a valve seat, a 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 a nozzle hole, a linkage connected to the rear end of the valve body, a movable core connected to the rear end of the linkage, and a fixed core facing the movable core; a return spring said fixed core and compressed state between the valve assembly for biasing the valve body in the valve closing side, is disposed so as to surround the fixed core, when energized, the movable by generating a magnetic force And a coil for opening the valve body by sucking the core into the fixed core, a fuel chamber communicating with a fuel supply unit is provided between the connection and the valve housing, and the valve body and the valve When the valve element is opened between the valve housings, the fuel chamber is It relates to an improvement of a fuel injection valve provided outside the fuel passage communicating with the nozzle hole.

  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 element is opened, the fuel in the outer fuel chamber on the outer periphery of the valve element is injected from the nozzle hole through a flow path formed between the valve element and the valve seat. By the way, with the increase in engine output, there is a demand for an increase in fuel injection amount. To meet this demand, the valve opening stroke of the valve body is set large, and the fuel flow path between the valve body and the valve seat is widened. Although it is conceivable, 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 power consumption of the coil.

  The present invention has been made in view of such circumstances, and can increase the fuel injection amount by enabling expansion of the fuel flow path around the valve body without increasing the valve opening stroke. An object of the present invention is to provide the fuel injection valve.

To achieve the above object, the present invention includes a nozzle member having a nozzle hole and a valve seat, a cylindrical valve housing which is provided continuously to the rear end of the nozzle member, is accommodated within the valve housing, said A valve assembly comprising a valve body for opening and closing the nozzle hole in cooperation with a valve seat , a linkage connected to the rear end of the valve body, and a movable core connected to the rear end of the linkage ; A fixed core facing the movable core, a return spring that is contracted between the fixed core and the valve assembly and biases the valve body toward the valve closing side, and is disposed so as to surround the fixed core, A coil for opening the valve body by attracting the movable core to the fixed core by the generated magnetic force when energized, and a fuel chamber communicating with the fuel supply unit between the connection and the valve housing. Between the valve body and the valve housing. In the fuel injection valve provided with an outer fuel passage that communicates the fuel chamber with the nozzle hole, the valve body is disposed at an annular valve portion facing the valve seat and a rear end of the valve portion. A connecting cylinder part connected to the front end of the linkage, the connecting cylinder part having a journal part slidably fitted to the inner peripheral surface of the valve housing; An outer fuel passage is formed in an annular shape so that it surrounds the valve portion, and a first notch that communicates the outer fuel passage with the fuel chamber is provided in the connecting cylinder portion, and inside the valve portion. When the valve element is opened, a cylindrical inner fuel passage that communicates with the nozzle hole is formed, and a second notch that communicates the inner fuel passage with the fuel chamber is provided at the front end of the joint. This is the first feature.

  According to the present invention, in addition to the first feature, an outer peripheral surface of the valve body facing the outer fuel passage is formed to have a smaller diameter than the journal portion, while facing the outer fuel passage of the valve housing. A second feature is that the inner peripheral surface is formed to have a larger diameter than the outer diameter of the journal portion.

  According to the first feature of the present invention, the valve body is connected to the annular valve portion and the rear end of the valve portion, and the connection end portion of the front portion of the linkage is fitted and connected. The connecting cylinder part has a journal part slidably fitted to the inner peripheral surface of the valve housing, and the outer fuel passage is formed in an annular shape so as to surround the valve part. In addition, a first notch that communicates this outer fuel passage with the fuel chamber on the outer periphery of the joint is provided in the connecting cylinder part, and the inside of the valve part is a cylindrical inner part that communicates with the nozzle hole when the valve body is opened. Since the second cutout that is formed in the fuel passage and communicates the inner fuel passage with the fuel chamber is provided in the connecting end portion, the fuel chamber and the nozzle hole are both cylindrical with a relatively large volume. The fuel passage around the valve body can be expanded by communicating with the inner fuel passage of the valve through the annular outer fuel passage. Thus without increasing the opening stroke of the valve body, the fuel injection amount from the nozzle holes obtained easily increased, it is possible to meet higher output of the engine. In addition, since there is no need to increase the valve opening stroke, it is possible to avoid an increase in the size of the coil and thus the fuel injection valve, and it is possible to suppress an increase in power consumption of the coil.

  Further, the connecting cylinder part of the valve body has a journal part slidably provided on the inner peripheral surface of the valve housing, so that the opening and closing posture of the valve body can be stabilized, and the first notch of the connecting cylinder part allows The fuel chamber and the outer fuel passage can be communicated with each other without being interfered by the journal portion.

  In addition, since the valve body and the linkage that are fitted and joined to each other are individually manufactured, the first notch can be easily formed as the valve body and the second notch can be easily formed as the linkage. , Productivity can be increased.

  According to the second feature of the present invention, the outer peripheral surface of the valve body facing the outer fuel passage is formed to have a smaller diameter than the journal portion, while the inner peripheral surface of the valve housing facing the outer fuel passage is journaled. The outer fuel passage is defined between the outer peripheral surface of the valve body having a smaller diameter than the journal portion and the inner peripheral surface of the valve housing having a larger diameter than the journal portion. As a result, the volume of the outer fuel passage can be enlarged, and the fuel passage around the valve body can be enlarged, so that the fuel injection amount from the nozzle hole can be easily increased.

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. 3 is a sectional view taken along line 3-3 in FIG. 2. 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, and gas fuel is supplied to the intake pipe E during the intake stroke 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-fitting 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 first notches 50, 50,... That open to the inner peripheral surface, the outer peripheral surface, and the rear end surface.

  The connecting rod 14 is composed of a pair of front and rear cylindrical connecting ends 14a and 14a and a connecting flange 14b integrally connecting the connecting ends 14a and 14a. There is no. One of the connecting end portions 14a is fitted to the inner peripheral surface of the connecting cylindrical portion 12a of the movable core 12 and connected by welding or the like, and the other connecting cylindrical portion 14a is connected to the inner periphery of the connecting cylindrical portion 13b of the valve body 13. Fitting to the surface and joining by welding or the like. In this way, the movable core 12, the linkage 14, and the valve body 13 are integrally coupled.

  Each connecting end 14 a of the linkage 14 has a circular recess 51 that opens to its end surface, a plurality of second notches 52 that open the recess 51 to the outer peripheral surface, and protrudes from the bottom surface of the recess 51. And a conical guide protrusion 53 is provided. Further, on the outer periphery of the flange portion 14b, a plurality of longitudinal grooves 54, 54... Communicating between the second notches 52, 52 of the front and rear connection end portions 14a, 14a are provided. A part of the rear end face of the rear connecting end portion 14 a fitted to the connecting cylindrical portion 12 a of the movable core 12 constitutes an annular front spring seat 34 that faces the front spring accommodating hole 30 of the movable core 12. Further, the front connecting end portion 14a and the connecting cylinder portion 13b of the valve body 13 are fitted so that the phases of the first and second notches 50 and 52 coincide with each other.

  Between the connecting rod 14 and the inner peripheral surface of the valve housing 3 facing the outer peripheral surface thereof, the vertical grooves 54, 54... Of the connecting rod 14 and the first notches 50, 50. The first 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. The inner fuel passage 56 communicates with the recess 51 and the second notches 52, 52... Of the front connection end 14a.

  An annular outer fuel passage 57 communicating with the first notches 50, 50... Of the valve body 13 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 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 hollow portion 36a of the spring retainer 36 is obtained. After passing through 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 concave portion 51 at the rear part of the linkage 14. The gas fuel that has flowed into the rear recess 51 is deflected in the radial direction by the conical guide protrusion 53 protruding from the bottom surface of the recess 51, so that a plurality of second notches 52, 52. Therefore, the gas fuel does not stagnate at the bottom of the recess 51. The gas fuel moved from the recess 51 to the fuel chamber 55 in the valve housing 3 flows forward, and a part of the fuel hits the bottom surfaces 50a of the plurality of first notches 50, 50. The fuel flows into the inner and outer fuel passages 56 and 57 substantially evenly, and the other fuel flows along the longitudinal grooves 54, 54... Of the linkage 14 and passes through the second notches 52, 52. Then, it flows into the inner fuel passage 56 inside the valve portion 13a. At that time, the gas fuel flowing down the bottom surfaces of the longitudinal grooves 54, 54... Can be guided into the lower conical guide protrusion 53 and smoothly flow into the recess 51. 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... Opening in the valve seat 7 both have a cylindrical inner fuel passage 56 and an annular outer fuel passage 57 having a relatively large volume. Therefore, the fuel flow path around the valve body 13 can be expanded, thereby easily increasing the fuel injection amount from the nozzle hole 9 without increasing the valve opening stroke of the valve body 13. As a result, it can respond to 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 and 57 are provided at the rear end portion of the valve body 13 and open to the inner peripheral surface, the outer peripheral surface and the rear end surface thereof, and the inner peripheral surface of the valve body 13. The valve body 13 and the connecting rod 14 are fitted to each other through the second notch 52 provided at the connecting end portion 14a of the front portion of the connecting rod 14 fitted and connected to the fuel chamber 55. The fuel can be smoothly diverted from the fuel chamber 55 to the inner and outer fuel passages 56 and 57 without being interrupted by the joint. In addition, the individual manufacture of the valve body 13 and the linkage 14 can be facilitated, and the first and second notches 50 and 52 can be formed at the time of manufacture, so that productivity can be improved.

  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 first notch 50 of the connecting cylinder portion 12a can communicate between the fuel chamber 55 and the outer fuel passage 57 without being interfered 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 body 13a ... valve part 13b ... connecting cylinder part 13b1 ... journal part 14 ... linkage 22 ... coil 50 ... first Notch 52 ... Second notch 55 ... Fuel chamber 56 ... Inner fuel passage 57 ... Outer fuel passage

Claims (2)

Nozzle holes (9) and the valve seat (7) a nozzle member having a (2), a cylindrical valve housing which is provided continuously to the rear end of the nozzle member (2) (3), wherein the valve housing (3) A valve body (13) accommodated in the valve seat (7) for opening and closing the nozzle hole (9) in cooperation with the valve seat (7), a linkage (14) connected to the rear end of the valve body (13 ) , A valve assembly (10) comprising a movable core (12) connected to the rear end of the linkage (14), a fixed core (5) facing the movable core (12), and the fixed core (5 ) And the valve assembly (10), and a return spring (33) for urging the valve body (13) toward the valve closing side, and a fixed core (5) are disposed to surround the return spring (33). , When energized, the movable core (12) is attracted to the fixed core (5) by the generated magnetic force to open the valve body (13). A fuel chamber (55) communicating with the fuel supply section is provided between the linkage (14) and the valve housing (3), and the valve body (13) and the valve A fuel injection valve provided with an outer fuel passage (57) that communicates the fuel chamber (55) with the nozzle hole (9) between the housings (3) when the valve body (13) is opened.
The valve body (13) is connected to an annular valve portion (13a) facing the valve seat (7) and a rear end of the valve portion (13a), and a front end portion of the linkage (14) is The connecting cylinder part (13b) includes a journal part (13b1) that is slidably fitted to the inner peripheral surface of the valve housing (3). The outer fuel passage (57) is annularly formed so as to surround the valve portion (13a), and the outer fuel passage (57) communicates with the fuel chamber (55) in a first notch (50). ) Is provided in the connecting cylinder part (13b), and a cylindrical inner fuel passage (communication to the nozzle hole (9) when the valve body (13) is opened is provided inside the valve part (13a)). 56) and a second notch (56) that communicates the inner fuel passage (56) with the fuel chamber (55). Fuel injection valve according to claim 2) that is provided on the front end portion of the connecting rod (14). The fuel injection valve according to claim 1, wherein
An 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 outer fuel passage (57) of the valve housing (3) is formed. The fuel injection valve is characterized in that the inner peripheral surface facing the nozzle is formed to have a larger diameter than the outer diameter of the journal portion (13b1).

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