JP2011144731A - Fuel injection valve - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To provide a fuel injection valve inhibiting the inclination of a valve element by inhibiting the deformation of a guide part. <P>SOLUTION: The opening side end of a side wall of a nozzle forming member extends to a nozzle holder side. The wall thickness of the side wall of the nozzle forming member is set thinner than that of a nozzle body. The ends of the nozzle holder and the nozzle body opposed to each other are butted against each other. The end of the nozzle holder and the nozzle body are press-fitted in the inner face of the side wall of the nozzle forming member and the end of the nozzle holder is welded to the side wall of a plate. <P>COPYRIGHT: (C)2011,JPO&amp;INPIT

Description

  The present invention relates to a fuel injection valve that injects fuel into, for example, an internal combustion engine.

  As a conventional fuel injection valve, one disclosed in Patent Document 1 below is known. In this fuel injection valve, a valve assembly in which a spherical valve portion is provided on one end side of an elongated movable core includes an elongated cylindrical valve housing and a bottomed cylindrical shape provided on one end side of the valve housing. It is accommodated in an internal space formed by the valve seat member.

  A first fitting tube portion is formed at the end of the valve seat member on the valve housing side, and a second fitting tube portion is formed at one end side of the valve housing. The valve housing and the valve seat member are joined by press-fitting the joint tube portion into the second fitting tube portion. And the outer peripheral surface of the 1st fitting cylinder part and the end surface of the 2nd fitting cylinder part are joined by welding over the perimeter.

  A valve hole for injecting fuel is formed at the bottom of the valve seat member, and an injector plate having a plurality of fuel injection holes communicating with the valve hole on the outside of the bottom of the valve seat member Are joined.

  A guide hole for guiding the valve portion is formed in the inner peripheral wall of the valve seat member. The valve assembly slides in the longitudinal direction in the inner space formed by the valve housing and the valve seat member, and opens and closes the valve hole by the valve portion. At this time, the valve portion is supported by the guide hole so that the valve assembly does not tilt with respect to the sliding direction.

JP 2003-206820 A

  In the conventional fuel injection valve, the first fitting cylinder part of the valve seat member is press-fitted and joined to the second fitting cylinder part of the valve housing. The portion is deformed toward the center in the radial direction, and the guide hole is also deformed accordingly. Furthermore, since the second fitting cylinder part and the first fitting cylinder part are joined by welding, heat at the time of welding is transmitted to the valve seat member, and the guide hole is thermally deformed. As the guide hole is deformed in this manner, the valve assembly during the sliding is inclined, and the fuel injection amount from the valve hole varies.

  An object of the present invention is made in view of the above points, and is to provide a fuel injection valve capable of suppressing deformation of a guide portion and suppressing inclination of a valve body.

  In order to achieve the above object, the present invention employs the following technical means.

That is, in the invention according to claim 1, a cylindrical nozzle holder to which fuel is supplied,
A nozzle body having a bottomed cylindrical shape, in which a fuel hole through which fuel flows is formed at the bottom, and the opening side of the bottomed cylindrical shape is connected to one end in the longitudinal direction of the nozzle holder;
A cup-shaped nozzle hole forming member that has a nozzle hole communicating with the fuel hole and is provided outside the bottomed cylindrical bottom;
A needle valve that is disposed in a space formed by the nozzle holder and the nozzle body, and opens and closes the fuel hole by reciprocating in the longitudinal direction to intermittently inject fuel from the nozzle hole,
In the fuel injection valve in which the inclination with respect to the reciprocating displacement direction of the needle is suppressed by the guide portion provided on the inner peripheral wall of the nozzle body,
The opening side end of the side wall of the nozzle hole forming member extends to the nozzle holder side, and the thickness of the side wall of the nozzle hole forming member is set smaller than the thickness of the nozzle body,
The opposite ends of the nozzle holder and nozzle body are butted together,
The tip of the nozzle holder and the nozzle body are press-fitted into the inner surface of the side wall of the nozzle hole forming member,
The tip of the nozzle holder and the side wall of the plate are welded.

  According to this invention, the nozzle hole forming member having the nozzle hole communicating with the fuel hole is formed in a cup shape. Moreover, the mutually opposing end portions of the nozzle holder and the nozzle body are abutted, and the tip portion of the nozzle holder and the nozzle body are press-fitted into the inner surface of the side wall of the cup-shaped nozzle hole forming member. Furthermore, the front-end | tip part of a nozzle holder and the side wall of a plate are joined by welding. Therefore, the nozzle body can be easily and reliably connected to the nozzle holder.

  Here, since the thickness of the nozzle hole forming member is set to be smaller than the thickness of the nozzle body, the rigidity of the nozzle body can be made larger than the rigidity of the nozzle hole forming member. When press-fitting into the inner surface of the side wall of the nozzle hole forming member, the deformation of the nozzle body can be suppressed, and the deformation of the guide portion formed on the inner peripheral wall of the nozzle body can be suppressed.

  Furthermore, since the tip of the nozzle holder and the side wall of the nozzle hole forming member are joined by welding, it is possible to suppress the heat at the time of welding from being directly transmitted to the nozzle body and to guide by the heat at the time of welding. The thermal deformation of the part can be suppressed.

  Therefore, it is possible to provide a fuel injection valve capable of suppressing the deformation of the guide portion and suppressing the inclination of the needle.

  The invention according to claim 2 is characterized in that the outer diameter of the nozzle holder and the nozzle body are formed to be the same.

  According to this invention, since the inner diameter dimension in the axial direction of the nozzle hole forming member can be set to be the same, the nozzle hole forming member can have a simple shape, and the molding of the nozzle hole forming member becomes easy.

In the invention according to claim 3, an O-ring for sealing is mounted on the outer peripheral side of the nozzle holder,
The opening side end of the side wall of the nozzle hole forming member is characterized in that a retaining portion for projecting outward in the radial direction of the nozzle holder and preventing the O-ring from slipping is formed.

  According to the present invention, in the case where the O-ring is mounted on the outer peripheral side of the nozzle holder, the stopper portion can be easily formed by utilizing the opening side end portion of the side wall of the nozzle hole forming member.

  The invention according to claim 4 is characterized in that the retaining portion is formed by press-fitting the opening side end portion of the side wall of the injection hole forming member inside the annular member formed in an annular shape. .

  According to this invention, the retaining portion can be easily formed by press-fitting the opening side end portion of the side wall of the nozzle hole forming member into the annular member.

  The invention according to claim 5 is characterized in that the retaining portion is a flange portion in which the opening side end portion of the side wall of the nozzle hole forming member is expanded and bent radially outward.

  According to the present invention, it is possible to easily form the retaining portion by providing the flange portion that is expanded and bent radially outward at the opening side end portion of the side wall of the nozzle hole forming member. In this case, since the retaining portion can be formed integrally with the nozzle hole forming member, the number of parts can be reduced.

  The invention according to claim 6 is characterized in that the retaining portion is formed by forming an annular member formed in an annular shape outside the opening side end portion of the side wall of the nozzle hole forming member. .

  According to this invention, since the annular member is formed outside the opening side end portion of the side wall of the nozzle hole forming member, the retaining portion can be formed and assembled at the same time. There is no need to prepare a stopper, and the number of steps for assembling the stopper in a single state by press-fitting can be reduced, and the stopper can be easily formed.

It is sectional drawing which shows the structure of the whole injector in 1st Embodiment to which this invention is applied. It is an enlarged view which shows the II section in FIG. It is sectional drawing which shows the O-ring vicinity of the injector in 2nd Embodiment to which this invention is applied. It is sectional drawing which shows the O-ring vicinity of the injector in 3rd Embodiment to which this invention is applied. It is sectional drawing which shows the O-ring vicinity of the injector in 4th Embodiment to which this invention is applied.

  A plurality of modes for carrying out the present invention will be described below with reference to the drawings. In each embodiment, parts corresponding to the matters described in the preceding embodiment may be denoted by the same reference numerals, and redundant description may be omitted. When only a part of the configuration is described in each mode, the other modes described above can be applied to the other parts of the configuration. Not only combinations of parts that clearly indicate that the combination is possible in each embodiment, but also a combination of the embodiments even if they are not clearly specified unless there is a problem with the combination. It is also possible.

(First embodiment)
Hereinafter, a first embodiment to which the present invention is applied will be described with reference to FIGS. 1 and 2. FIG. 1 is a cross-sectional view showing the overall structure of an injector 100A in the first embodiment, and FIG. 2 is an enlarged view showing a II part in FIG.

  The injector 100A is a fuel injection valve, and is applied to, for example, a port injection type gasoline engine. When the injector 100A is applied to a port injection type gasoline engine, the injector 100A is mounted on an engine head (not shown).

  As shown in FIGS. 1 and 2, the injector 100 </ b> A includes a tubular member 110, a nozzle holder 120, a nozzle body 130, an injection hole forming member 140, a needle valve 150, and a drive unit 160. Hereinafter, as the direction of the injector 100A, a direction in which the tubular member 110 extends is referred to as an axial direction Z (vertical direction in FIG. 1), and one of the axial directions Z is defined as a valve opening direction Z1 (upward in FIG. The other side of the axial direction Z is referred to as the valve closing direction Z2 (downward in FIG. 1, the nozzle hole 142 side).

  The cylindrical member 110 is formed in a cylindrical shape whose inner diameter is substantially the same in the axial direction Z. The cylindrical member 110 includes a fuel inlet portion 111, a fuel filter 112, a magnetic portion 113, and a nonmagnetic portion 114. The fuel inlet 111 is an opening that opens at the end of the tubular member 110 on the valve opening direction Z1 side. The fuel filter 112 is a filter provided at the fuel inlet 111 to remove foreign matters contained in the fuel. Fuel supplied from a fuel pump (not shown) flows into the inner peripheral side of the cylindrical member 110 via the fuel inlet 111 and the fuel filter 112.

  The magnetic part 113 is a part having magnetism in the cylindrical member 110, and the non-magnetic part 114 is a part having no magnetism in the cylindrical member 110. The most part of the cylindrical member 110 is formed as a magnetic part 113, and the nonmagnetic part 114 is formed at the end of the cylindrical member 110 on the valve closing direction Z2 side. The nonmagnetic part 114 prevents a magnetic short circuit between the magnetic part 113 and a nozzle holder 120 described later.

  The nozzle holder 120 is formed in a cylindrical shape, and is provided at the end of the cylindrical member 110 on the valve closing direction Z2 side. The nozzle holder 120 has magnetism. Therefore, the nonmagnetic portion 114 of the cylindrical member 110 is located between the magnetic portion 113 and the magnetic nozzle holder 120 in the axial direction Z.

  The nozzle body 130 is formed in a bottomed cylindrical shape, and the opening-side end portion of the bottomed cylindrical shape is attached to and connected to the valve closing direction Z2 side end portion of the nozzle holder 120. The outer diameter of the nozzle body 130 is set to be substantially the same as the outer diameter of the nozzle holder 120 within a tolerance range. The wall thickness of the side wall of the nozzle body 130 is set larger than the wall thickness of the nozzle holder 120.

  A fuel hole 131 through which fuel flows from the inside of the nozzle body 130 to the outside (engine cylinder) is provided at the center of the bottom of the nozzle body 130. The outer peripheral side of the fuel hole 131 inside the nozzle body 130 is formed in a mortar shape that inclines so that the inner diameter increases in the valve opening direction Z1, and the mortar-shaped inclined portion is a seal for a needle valve 150 described later. The valve seat 132 is seated by the portion 155.

  Inside the side wall of the nozzle body 130, a guide portion 133 that suppresses the inclination of the needle valve 150 with respect to the reciprocating displacement direction, that is, the axial direction Z is formed. The guide part 133 is disposed at the end of the side wall of the nozzle body 130 on the valve opening direction Z1 side, and is formed so as to protrude toward the center side of the bottomed cylindrical shape. That is, the inner diameter of the bottomed cylindrical nozzle body 130 gradually increases from the fuel hole 131 side toward the opening side, then a section having a constant inner diameter is formed, and the inner diameter decreases further on the opening side. The inner peripheral wall of the portion formed with a small inner diameter serves as a guide portion 133.

  The nozzle hole forming member 140 is a member in which a thin plate material is formed in a cup shape by, for example, deep drawing. The thickness of the nozzle hole forming member 140 is set to be smaller than the thickness of the side wall of the nozzle body 130 and the thickness of the nozzle holder 120. That is, the thickness of each member becomes smaller in the order of the nozzle body 130, the nozzle holder 120, and the nozzle hole forming member 140.

  The bottom 141 of the cup-shaped nozzle hole forming member 140 has a circular plate shape corresponding to the bottom of the nozzle body 130, and is disposed outside the bottom of the nozzle body 130. A plurality of injection holes 142 communicating with the fuel holes 131 are formed at the center of the bottom portion 141. The plurality of injection holes 142 are arranged so as to be dispersed in the region of the fuel holes 131. The inner diameter of one injection hole 142 is formed smaller than the inner diameter of the fuel hole 131, and the plurality of injection holes 142 make the fuel flowing out from the fuel hole 131 fine.

  The side wall 143 of the cup-shaped nozzle hole forming member 140 is formed so as to extend from the outer peripheral edge of the bottom portion 141 to the nozzle holder 120 side (valve opening direction Z1 side). The opening-side end 144 on the side of the valve opening direction Z1 of the side wall 143 is set at a position separated from the valve-closing direction Z2 side end of the nozzle holder 120 by a predetermined length toward the valve opening direction Z1. . The opening end 144 is smoothly expanded outward in the radial direction. The inner diameter of the side wall 140 is set to be slightly smaller than the outer diameters of the nozzle holder 120 and the nozzle body 130.

  Hereinafter, the details of the connection structure of the nozzle holder 120, the nozzle body 130, and the nozzle hole forming member 140 will be described with reference to FIG.

  The opposite end portions of the nozzle holder 120 and the nozzle body 130, that is, the end portion on the valve closing direction Z2 side of the nozzle holder 120, and the end portion on the valve opening direction Z1 side of the nozzle body 130 face each other. Then, the entire region in the axial direction Z of the nozzle body 130 and the region for a predetermined length from the end in the valve closing direction Z2 side of the nozzle holder 120 toward the valve opening direction Z1 side are on the side wall 143 of the injection hole forming member 140. It is press-fitted into the inner peripheral surface. By this press fitting, the bottom of the nozzle body 130 is in contact with the bottom 141 of the nozzle hole forming member 140. Furthermore, the bottom of the nozzle body 130 and the bottom 141 of the nozzle hole forming member 140 are joined by welding. The welding between the nozzle body 130 and the nozzle hole forming member 140 draws a circle around the bottom 141 in the region outside the fuel hole 131 and the plurality of nozzle holes 142, as indicated by the black triangles in FIG. Has been done so. Therefore, in joining the nozzle body 130 and the nozzle hole forming member 140, the side wall of the nozzle body 130 and the side wall 143 of the nozzle hole forming member 140 are not welded. Welding in the vicinity of the outer peripheral side is not performed. Further, the outer peripheral surface of the end portion on the valve closing direction Z2 side of the nozzle holder 120 and the inner peripheral surface of the nozzle hole forming member 143 are joined by welding. The welding between the nozzle holder 120 and the nozzle hole forming member 140 is performed over the circumferential direction of the side wall 143 as shown by black triangle marks in FIG.

  The nozzle holder 120 and the nozzle body 130 are pressed into the side wall 143 as follows. First, the nozzle body 130 is press-fitted into the inner peripheral surface of the side wall 143. At this time, the nozzle body 130 is press-fitted until the bottom of the nozzle body 130 contacts the bottom 141 of the nozzle hole forming member 140. And the bottom part of the nozzle body 130 and the bottom part 141 of the nozzle hole formation member 140 are joined by welding. Next, the end of the nozzle holder 120 in the valve closing direction Z <b> 2 is press-fitted into the inner peripheral surface of the side wall 143. At this time, the end of the nozzle holder 120 in the valve closing direction Z2 side is press-fitted so as to come into contact with the end of the nozzle body 130 in the valve opening direction Z1 side. And the edge part of the nozzle holder 120 and the side wall 143 are joined by welding.

  When the nozzle body 130 and the nozzle holder 120 are press-fitted into the inner peripheral surface of the side wall 143, the opening-side end 144 of the side wall 143 is smoothly expanded radially outward, so that press-fitting is easy.

  The needle valve 150 is an elongated valve member extending in the axial direction Z, and is accommodated in an internal space formed by the nozzle holder 120 and the nozzle body 130 so as to be capable of reciprocating in the axial direction Z. The needle valve 150 opens and closes the fuel hole 131 by reciprocating in the axial direction Z, and intermittently injects fuel from the injection hole 142. The needle valve 150 is disposed substantially coaxially with the nozzle holder 120 and the nozzle body 130, and includes a shaft portion 151, an inflow port 152, communication holes 153 and 154, and a seal portion 155.

  The shaft portion 151 is an elongated cylindrical member whose end in the valve closing direction Z2 is closed, and constitutes a main body portion of the needle valve 150. The inflow port 152 is an opening that opens on the valve opening direction Z1 side of the shaft portion 151. The communication holes 153 are circular holes that are opened in the circumferential direction of the shaft portion 151 near the inflow port 152. The communication hole 153 allows the inside of the shaft portion 151 to communicate with the internal space formed in the nozzle holder 120 and the nozzle body 130. The communication hole 154 is an oval hole having a plurality of openings in the circumferential direction of the shaft portion 151 in the vicinity of the end portion on the valve closing direction Z2 side of the shaft portion 151. The communication hole 154 allows the inside of the shaft portion 151 to communicate with the internal space formed in the nozzle holder 120 and the nozzle body 130. Further, the seal portion 155 is formed by chamfering along the inclination of the valve seat 132 of the nozzle body 130 at the end portion of the shaft portion 151 on the valve closing direction Z2 side. The seal portion 155 can be seated on the valve seat 132. The end of the needle valve 150 on the valve opening direction Z1 side is joined to a movable core 162 described later.

  The drive unit 160 drives the needle valve 150 along the axial direction Z, and in addition to the cylindrical member 110 and the nozzle holder 120, the fixed core 161, the movable core 162, the spool 163, the coil 164, the upper magnetism A plate 165, a lower magnetic plate 166, an adjusting pipe 167, and a spring 168 are provided.

  The fixed core 161 is formed in a cylindrical shape from a magnetic material such as iron, and is fixed to the inner peripheral side of the cylindrical member 110 by, for example, press fitting. The valve closing direction Z2 side end of the fixed core 161 is positioned on the valve opening direction Z1 side by a predetermined amount from the valve closing direction Z2 side end of the cylindrical member 110, and the valve opening direction Z1 side end of the fixed core 161 is Reaches the middle region of the cylindrical member 110.

  The movable core 162 is installed so as to be capable of reciprocating in the axial direction Z on the inner peripheral side of the cylindrical member 110 and the nozzle holder 120 on the valve closing direction Z2 side of the fixed core 161. The movable core 162 is formed in a cylindrical shape from a magnetic material such as iron. A seating surface that protrudes toward the center of the shaft is formed at the center in the axial direction Z of the movable core 162. This seat surface is a seat surface with which the end of the spring 167 in the valve closing direction Z2 abuts. The inner diameter of the movable core 162 on the valve opening direction Z1 side is set substantially equal to the inner diameter of the fixed core 161. Further, the needle valve 150 is joined to the movable core 162 on the valve closing direction Z2 side by press-fitting and welding, and the inner space of the movable core 162 and the inner space of the needle valve 150 are communicated with each other.

  On the outer periphery of the end portion on the valve opening direction Z1 side of the movable core 162, an outer peripheral surface portion slightly protruding outward in the radial direction is formed, and this outer peripheral surface portion is in contact with the inner peripheral surface portion of the nonmagnetic portion 114. It is displaced in the axial direction Z. Thereby, the movable core 162 is guided to move in the axial direction Z by the nonmagnetic portion 114.

  The spool 163 is a member made of a resin and formed in a cylindrical shape, and is installed on the outer peripheral side of the cylindrical member 110 so as to correspond to the positions of the nonmagnetic portion 114 and both end portions thereof. The coil 164 is a winding that generates a magnetic force that attracts the movable core 162 to the fixed core 161 when energized, and is wound around the outer periphery of the spool 163. The coil 164 is electrically connected to the terminal portion 164b of the connector 164a. The terminal portion 164b is electrically connected to an external electric circuit (not shown) attached to the connector 164a, and the energization state to the coil 164 is controlled by the external electric circuit.

  The upper magnetic plate 165 is made of a magnetic material and is provided so as to cover the outer periphery of the coil 164 on the valve opening direction Z1 side. The lower magnetic plate 166 is made of a magnetic material and is provided so as to cover the outer periphery of the coil 164 on the valve closing direction Z2 side. The valve closing direction Z2 side of the lower magnetic plate 166 is formed as a small diameter portion 166a having a smaller outer diameter than the valve opening direction Z1 side, and this small diameter portion 166a is connected to the outer peripheral surface of the nozzle holder 120. . Furthermore, a groove portion 166b is formed in the circumferential direction on the outer peripheral surface of the end portion on the valve closing direction Z2 side of the small diameter portion 166a.

  The adjusting pipe 167 is a cylindrical member and is press-fitted into the inner peripheral portion of the fixed core 161 on the valve opening direction Z1 side. The spring 168 is an elastic member and is disposed inside the fixed core 161 and the movable core 162. That is, the end portion of the spring 168 in the valve closing direction Z2 side is in contact with the seating surface of the movable core 162, and the end portion in the valve opening direction Z1 side is in contact with the adjusting pipe 167. The spring 168 has a force that extends in the axial direction Z. Therefore, the movable core 162 and the needle valve 150 are pressed by the spring 168 in the valve closing direction Z2 that is seated on the valve seat 132. The load of the spring 168 is adjusted by adjusting the amount of press-fitting of the adjusting pipe 167. When the coil 164 is not energized, the movable core 162 and the needle valve 150 are pressed in the valve closing direction Z2, and the seal portion 155 is seated on the valve seat 132.

  Sealing the inside and outside of the engine head when the injector 100A is mounted on the engine head is performed on the outer peripheral side that is the valve opening direction Z1 side of the nozzle holder 120, that is, on the outer peripheral surface of the small diameter portion 166a of the lower magnetic plate 166. An O-ring 170 is attached. An annular member 171 formed in an annular shape is attached to the groove 166 b of the lower magnetic plate 166. The annular member 171 includes a disk-shaped portion that protrudes radially outward from the annular main body portion. The O-ring 170 is sandwiched between the step of the lower magnetic plate 166 (the step where the small-diameter portion 166a is formed) and the annular member 171. The O-ring 171 is closed by the annular member 171 in the valve closing direction Z2 side. I try to prevent it from slipping out.

  Next, the operation of the injector 100A configured as described above will be described.

  First, the operation when the valve is opened will be described. When energization of the coil 164 is stopped, no magnetic attractive force is generated between the fixed core 161 and the movable core 162. Therefore, the movable core 162 is pressed by the valve closing force f that is the pressing force of the spring 168, moves in the valve closing direction Z2, and moves away from the fixed core 161. Accordingly, the needle valve 150 also moves in the valve closing direction Z <b> 2, and the seal portion 155 is seated on the valve seat 132. Therefore, the fuel hole 131 is closed and fuel is not injected from the injection hole 142.

  When the coil 164 is energized from the valve closed state as described above, the magnetic field generated in the coil 164 causes a magnetic flux in the upper magnetic plate 165, the magnetic part 113, the fixed core 161, the movable core 162, the nozzle holder 120, and the lower magnetic plate 166. Flows to form a magnetic circuit. As a result, a magnetic attractive force is generated between the fixed core 161 and the movable core 162. When the magnetic attractive force generated between the fixed core 161 and the movable core 162 becomes larger than the valve closing force f of the spring 168, the movable core 162 starts to move in the valve opening direction Z1. At this time, the needle valve 150 moves together with the movable core 162 in the valve opening direction Z1. As a result, the seal portion 155 of the needle valve 150 is separated from the valve seat 132 and the fuel hole 131 is opened.

  The fuel that has flowed into the cylindrical member 110 from the fuel inlet portion 111 flows into the fuel filter 112, the inner peripheral side of the cylindrical member 110, the inner peripheral side of the adjusting pipe 167, the inner peripheral side of the fixed core 161, and the movable core 162. It flows into the inner peripheral side of the shaft portion 151 of the needle valve 150 through the peripheral side and the inlet 152 in order. The fuel that has flowed into the shaft 151 passes through the communication holes 153 and 154, passes between the nozzle holder 120 and the needle valve 150, and between the nozzle body 130 and the needle valve 150, and flows into the fuel hole 131. . Thereby, fuel is injected from the injection hole 142.

  Next, the operation when the valve is closed will be described. When energization to the coil 164 is stopped from the valve open state, the magnetic attractive force between the fixed core 161 and the movable core 162 disappears. Thereby, the movable core 162 starts to move in the valve closing direction Z2 by the valve closing force f of the spring 163. Then, the needle valve 150 starts moving in the valve closing direction Z2 together with the movable core 162. Therefore, the seal portion 155 of the needle valve 150 is again seated on the valve seat 132, the flow of fuel in the nozzle holder 120 and between the nozzle body 130 and the fuel hole 131 is cut off, and fuel is injected from the injection hole 142. Ends.

  When the needle valve 150 is reciprocally displaced in the axial direction Z when the valve is opened or closed, the outer peripheral surface portion of the movable core 162 is guided to the inner peripheral surface portion of the nonmagnetic portion 114, and the needle valve 150 The needle valve 150 is prevented from tilting with respect to the axial direction Z by guiding the end in the valve closing direction Z2 to the guide 133.

  In the present embodiment, in the injector 100A, the nozzle hole forming member 140 having the nozzle holes 142 communicating with the fuel holes 131 of the nozzle body 130 is formed in a cup shape. Further, the end portions of the nozzle holder 120 and the nozzle body 130 facing each other are butted together, and the end portion of the nozzle holder 120 in the valve closing direction Z2 and the nozzle body 130 are press-fitted into the inner surface of the side wall 143. Further, the end of the nozzle holder 120 in the valve closing direction Z2 and the side wall 143 are joined by welding. Therefore, the nozzle body 130 can be easily and reliably connected to the nozzle holder 120.

  Here, since the thickness of the nozzle hole forming member 140 is set to be smaller than the thickness of the side wall of the nozzle body 130, the rigidity of the nozzle body 130 is made larger than the rigidity of the nozzle hole forming member 140. When the nozzle body 130 is press-fitted into the inner surface of the side wall 143, the deformation of the nozzle body 130 can be suppressed, and the deformation of the guide portion 133 formed on the inner peripheral wall of the nozzle body 130 can be suppressed.

  Furthermore, since the end of the nozzle holder 120 in the valve closing direction Z2 side and the side wall 143 are welded and joined, the heat at the time of welding is suppressed from being directly transmitted to the nozzle body 130, and the heat at the time of welding is suppressed. The thermal deformation of the guide part 133 due to can be suppressed.

  Therefore, it is possible to provide the injector 100A that can suppress the deformation of the guide portion 133 and suppress the inclination of the needle valve 150.

  Moreover, since the outer diameter dimensions of the nozzle holder 120 and the nozzle body 130 are set to be substantially the same, the inner diameter dimension in the axial direction of the nozzle hole forming member 140 can be set to be the same, and the nozzle hole The forming member 140 can have a simple shape, and the injection hole forming member 140 can be easily formed.

(Second Embodiment)
An injector 100B of the second embodiment is shown in FIG. In the injector 100B in the second embodiment, the length of the nozzle holder 120 and the needle valve 150 in the axial direction Z is shorter than that of the injector 100A in the first embodiment, and the opening-side end 144 of the side wall 143 is made the lower magnetic plate. 166 is disposed close to the end in the valve closing direction Z2 side. In the lower magnetic plate 166, the groove 166b described in the first embodiment is abolished, and a retaining portion 172 is provided at the opening end 144 of the side wall 143. The retaining portion 172 is an annular member formed in an annular shape.

  Here, the outermost diameter of the opening-side end 144 of the side wall 143 is set to be slightly larger than the inner diameter of the retaining portion 172 on the valve closing direction Z2 side. The inner diameter dimension of the retaining portion 172 on the valve opening direction Z1 side is set to be larger than the outer diameter dimension of the lower magnetic plate 166 on the valve closing direction Z2 side. The opening-side end 144 of the side wall 141 is press-fitted into the valve closing direction Z2 side of the retaining part 172, and the retaining part 172 is fixed to the side wall 143.

  The press-fitting of the retaining portion 172 is performed as follows. That is, first, the nozzle body 130 is press-fitted into the nozzle hole forming member 140, then the retaining portion 172 is press-fitted into the side wall 143, and finally, the nozzle holder 120 is press-fitted into the side wall 143.

  As a result, the groove 166b of the lower magnetic plate 166 can be eliminated, and the retaining portion 172 can be fixed by press-fitting using the opening-side end 144 of the side wall 143, which facilitates parts processing and assembly. Can do.

(Third embodiment)
An injector 100C of the third embodiment is shown in FIG. The injector 100C in the third embodiment is formed as a flange portion 145 in which the retaining portion 172 is abolished and the opening side end portion of the side wall 143 is expanded and bent radially outward with respect to the injector 100B in the second embodiment. ing. The outer diameter of the flange portion 145 is set so as to be larger than the outer diameter of the opening-side end portion 144 of the second embodiment and further to the outside of the center point of the circular cross section of the O-ring 170 in FIG. Is good.

  Thereby, since the flange part 145 provided in the side wall 143 can be used as a retaining part, the retaining part 172 can be eliminated, and the number of parts with respect to the retaining part 172 described in the second embodiment can be reduced. In addition, the assembly man-hours can be reduced.

(Fourth embodiment)
An injector 100D of the fourth embodiment is shown in FIG. An injector 100C according to the fourth embodiment is formed by forming a retaining portion 173 with respect to the injector 100B according to the second embodiment. The retaining portion 173 is an annular member formed in an annular shape.

  In the fourth embodiment, after the assembly of the injector 100D is formed, this assembly is put into a resin molding die, and the retaining portion 173 is molded out of the opening side end 144 of the side wall 143 with a resin material. Yes.

  As a result, the retaining portion 173 can be molded and assembled at the same time, so there is no need to prepare a retaining portion in a single state, and the number of steps for assembling the retaining portion in a single state by press-fitting is reduced. Therefore, the retaining portion 173 can be easily formed.

(Other embodiments)
The preferred embodiments of the present invention have been described above, but the present invention is not limited to the above-described embodiments, and various modifications can be made without departing from the spirit of the present invention.

  In the first to fourth embodiments, the outer diameter of the nozzle holder 120 and the nozzle body 130 is set to be substantially the same. However, the setting is not limited to this, and different settings may be used. For example, under the condition that the opposite ends of the nozzle holder 120 and the nozzle body 130 face each other, the outer diameter of the nozzle holder 120 is made larger than the outer diameter of the nozzle body 130, and the inner diameter dimension of the nozzle hole forming member 140 is The nozzle holder 120 and the nozzle body 130 may be different from each other.

  In the first, second, and fourth embodiments, the opening-side end 144 of the side wall 143 is formed so as to expand smoothly, but a straight side wall 143 may be used.

  Further, in each embodiment, the needle valve 150 is joined to the movable core 162, and the valve closing force f is applied to the movable core 162 and the needle valve 150 by one spring 168. The present invention may be applied to a fuel injection valve in which the needle valve 150 and the movable core 162 are separated, and a spring acting on each of the needle valve 150 and the movable core 162 is provided.

  Moreover, in each embodiment, although the main-body part of injector 100A-D was mainly comprised from the cylindrical member 110 and the nozzle holder 120, not only this but the cylindrical member 100 and the nozzle holder 120 were integrally formed. It is good also as a thing etc. with which the cylindrical member 110 was formed from the some member.

  Further, the fixed form of the fixed core 161 in the housing is not limited to the above-described embodiments. For example, the fixed core 161 may be integrated with the magnetic part 113 of the cylindrical member 110.

  In each of the above embodiments, the injectors 100A to 100D are applied to a port injection type gasoline engine. However, the injectors 100A to 100D are not limited to a port injection type gasoline engine, but are a direct injection type gasoline engine or a diesel engine. You may apply to.

100A-D injector (fuel injection valve)
DESCRIPTION OF SYMBOLS 120 Nozzle holder 130 Nozzle body 131 Fuel hole 133 Guide part 140 Injection hole formation member 141 Bottom part 142 Injection hole 143 Side wall 144 Opening side edge part 145 Flange part 150 Needle valve 170 O-ring 172, 173 Retaining part

Claims (6)

A cylindrical nozzle holder in which fuel is supplied; and
A nozzle body having a bottomed cylindrical shape, in which a fuel hole through which the fuel flows is formed at the bottom, and the opening side of the bottomed cylindrical shape is connected to one end in the longitudinal direction of the nozzle holder;
A cup-shaped nozzle hole forming member that has a nozzle hole communicating with the fuel hole and is provided outside the bottomed cylindrical bottom;
A needle valve which is disposed in a space formed by the nozzle holder and the nozzle body and which opens and closes the fuel hole by reciprocating in the longitudinal direction to intermittently inject fuel from the nozzle hole. ,
In the fuel injection valve in which the inclination with respect to the reciprocating displacement direction of the needle is suppressed by the guide portion provided on the inner peripheral wall of the nozzle body,
The opening side end of the side wall of the nozzle hole forming member extends to the nozzle holder side, and the thickness of the side wall of the nozzle hole forming member is set smaller than the thickness of the nozzle body,
The opposite ends of the nozzle holder and the nozzle body are abutted,
The tip of the nozzle holder and the nozzle body are press-fitted into the inner surface of the side wall of the nozzle hole forming member,
A fuel injection valve, wherein a tip end portion of the nozzle holder and a side wall of the plate are welded.   The fuel injection valve according to claim 1, wherein the nozzle holder and the nozzle body have the same outer diameter. An O-ring for sealing is mounted on the outer peripheral side of the nozzle holder,
2. The retaining portion for preventing the O-ring from slipping out is formed at an opening side end portion of the side wall of the nozzle hole forming member so as to protrude radially outward of the nozzle holder. The fuel injection device according to claim 2.   4. The fuel according to claim 3, wherein the retaining portion is formed by press-fitting an opening-side end portion of the side wall of the nozzle hole forming member inside an annular member formed in an annular shape. Injection valve.   4. The fuel injection valve according to claim 3, wherein the retaining portion is a flange portion in which an opening side end portion of a side wall of the nozzle hole forming member is expanded and bent outward in the radial direction.   4. The fuel according to claim 3, wherein the retaining portion is formed by forming an annular member formed in an annular shape outside an opening side end portion of a side wall of the nozzle hole forming member. Injection valve.

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