JP6270598B2 - Fuel injection device - Google Patents

Description

  The present invention relates to a fuel injection device for an internal combustion engine, and more particularly, to a fuel injection device provided with a sensor for detecting a state of a combustion chamber at a tip portion facing the combustion chamber.

  In a direct injection internal combustion engine, the fuel injection device is disposed in the cylinder head so that the tip of the valve body that forms the outer shell faces the combustion chamber. An injection hole is formed at the tip of the valve body, and fuel is injected from the injection hole into the combustion chamber in accordance with the driving of the valve body provided in the valve body. In such a fuel injection device, there is one in which a pressure sensor for detecting an in-cylinder pressure is supported at the tip of a valve body (for example, Patent Document 1). In the fuel injection device according to Patent Document 1, the pressure sensor is formed in an annular shape, and the tip of the valve body is inserted inside the pressure sensor, and is fixed to the valve body so as to face the combustion chamber.

  In such a fuel injection device, since the pressure sensor is supported by the valve body, it is not necessary to change the shape of the combustion chamber or the cylinder head in order to provide the pressure sensor. Further, since the pressure sensor can be disposed so as not to contact the cylinder head, vibrations of other cylinders, valve mechanism, and head cover transmitted through the cylinder head are less likely to affect the pressure sensor. Further, since the pressure sensor is cooled by the fuel passing through the inside of the valve body, damage due to heat is suppressed.

International Publication No. 2012/115036

  In the fuel injection device disclosed in Patent Document 1, after an annular pressure sensor is tightly fitted to the outer periphery of the valve body, the valve body and the end of the pressure sensor on the combustion chamber side are welded together. Therefore, the sensor may be deformed by welding heat, and stress may remain in the pressure sensor to change the detection characteristics of the pressure sensor. Further, in order to hermetically seal the gap between the outer periphery of the valve body and the inner periphery of the pressure sensor, welding must be performed over the entire inner periphery of the pressure sensor. Since the valve body and the pressure sensor are minute parts, there is a problem that high technology and a highly accurate apparatus are required for welding, and productivity is poor.

  In view of the above background, the present invention provides a fuel injection device provided with a sensor for detecting the state of a combustion chamber at a front end facing the combustion chamber, and hermetically seals between the fuel injection device and the sensor with a simple configuration. This is the issue.

  In order to solve the above problems, the present invention provides a valve body (41, 45) having a tip (41, 45) inserted into an injector hole (19) formed in an internal combustion engine body (3) and facing a combustion chamber (7). 33), a sensor (38) that is formed in a cylindrical shape, has a distal end portion of the valve body inserted therein, and is supported by an outer peripheral portion of the valve body, and an outer surface of the valve body and an inner surface of the sensor. An annular seal member (108) for sealing the gap, and a tip portion of the sensor disposed on the combustion chamber side extends to the combustion chamber side from the tip portion of the valve body, and is disposed on the inner surface thereof. The valve body has a locking portion (103) protruding toward the axial line side, and the seal member is disposed at a corner portion (101) formed by the inner surface of the sensor and the outer peripheral portion of the distal end surface of the valve body. And said locking Characterized in that it is sandwiched between said valve body.

  According to this configuration, since the gap between the inner surface of the sensor and the outer surface of the valve body is sealed by the sealing member, there is no need to seal the gap by welding, and the detection characteristics of the sensor due to the deformation of the sensor due to welding heat can be reduced. No change occurs.

  In the above invention, the seal member is flexible, receives a compressive force from the axial direction of the valve body by the locking portion and the valve body, and is in close contact with the sensor and the valve body. It is good to have.

  According to this configuration, the seal member, the inner surface of the sensor, and the tip surface of the valve body are in close contact with each other, so that the gap between the inner surface of the sensor and the outer surface of the valve body is reliably sealed.

  In the invention described above, the locking portion may extend in a circumferential direction around the axis of the valve body and be formed in an annular shape.

  According to this configuration, since the seal member is sandwiched between the locking portion and the valve body on the entire circumference, the seal is further ensured.

  In the above invention, the locking portion may have a wall portion (106) extending toward the tip end surface (45A) of the valve body at the protruding end.

  According to this configuration, the wall portion locks the seal member deformed by being sandwiched between the locking portion and the valve body, and the separation of the sealing member from the locking portion and the valve body is prevented. Suppress. Thereby, the contact pressure between the seal member, the valve body, and the sensor is increased, and high sealing performance is obtained. Moreover, when the wall portion covers the seal member, the exposed area of the seal member to the combustion chamber is reduced, and contact between the seal member and the high-temperature gas in the combustion chamber is suppressed. Thereby, deterioration of a sealing member is suppressed.

  In the above invention, it is preferable that the wall portion has flexibility and is in contact with the distal end surface of the valve body while being elastically deformed.

  According to this structure, the exposed area of the seal member to the combustion chamber is further reduced by extending the tip of the wall portion until it contacts the tip surface of the valve body, and the contact between the seal member and the hot gas in the combustion chamber is reduced. It is further suppressed.

  Further, in the above invention, the locking portion and the wall portion extend in a circumferential direction around the axis of the valve body, are formed in an annular shape, and the wall portion and the distal end surface of the valve body The contact portion may be formed in an annular shape around the axis of the valve body.

  According to this configuration, the seal member is covered with the locking portion and the wall portion and is not exposed to the combustion chamber. Therefore, the seal member is prevented from coming into contact with the high temperature gas in the combustion chamber, and deterioration is suppressed.

  Further, in the above invention, the locking portion is a groove portion (201) recessed in a direction opposite to the distal end surface side of the valve body at a portion of the base portion facing the distal end surface side of the valve body. It is good to have.

  According to this configuration, the seal member that is deformed by receiving a compressive force between the locking portion and the front end surface of the valve body is guided to the groove portion side, and maintains a high contact pressure with the inner surface of the sensor. Can do.

  In the above invention, it is preferable that the seal member has a smaller width in the axial direction of the valve body in the outer peripheral side portion than in the inner peripheral side portion.

  According to this configuration, the seal member that is deformed by receiving a compressive force between the locking portion and the distal end surface of the valve body is guided to the outer peripheral side when the pressure on the outer peripheral side becomes smaller than the inner peripheral side, Contact with the inner surface of the sensor can be maintained.

  In the above invention, the tip end surface of the valve body may be formed as an inclined surface whose central side protrudes from the outer peripheral side.

  According to this configuration, the seal member that is deformed by receiving a compressive force between the locking portion and the distal end surface of the valve body is guided to the outer peripheral side of the distal end portion of the valve body and maintains contact with the inner surface of the sensor. can do.

  According to the above configuration, in the fuel injection device provided with the sensor for detecting the state of the combustion chamber at the front end facing the combustion chamber, the space between the fuel injection device and the sensor can be hermetically sealed with a simple configuration. .

Sectional drawing of the internal combustion engine with which the fuel-injection apparatus which concerns on 1st Embodiment was attached Sectional drawing of the fuel-injection apparatus which concerns on 1st Embodiment The expanded sectional view of the tip part of the fuel injection device concerning a 1st embodiment (A) Cross-sectional view in which the sensor is mounted on the small-diameter portion of the first body in the first embodiment, (B) Cross-sectional view in a state before the sensor is mounted on the small-diameter portion of the first body in the first embodiment. Sectional drawing of the state before mounting | wearing with the small diameter part of a 1st body in 2nd Embodiment. (A) Sectional view of the state before mounting the sensor on the small diameter portion of the first body in the third embodiment, (B) Before mounting the sensor on the small diameter portion of the first body in the modification of the third embodiment. Cross section of the state Sectional drawing of the state before mounting | wearing with the small diameter part of a 1st body in 4th Embodiment. (A) Cross-sectional view of the state before mounting the sensor on the small-diameter portion of the first body in the fifth embodiment, (B) Cross-sectional view of mounting the sensor on the small-diameter portion of the first body in the fifth embodiment.

  Embodiments in which the present invention is applied to a fuel injection device for a direct injection internal combustion engine of an automobile will be described below in detail with reference to the drawings.

(First embodiment)
As shown in FIG. 1, an automobile internal combustion engine 1 includes a cylinder block 2 and a cylinder head 3 joined to an upper portion of the cylinder block 2. A plurality of cylinders 4 are formed in the cylinder block 2, and a piston 5 is slidably received in each cylinder 4 along the axis of the cylinder 4. A portion of the cylinder head 3 that faces each cylinder 4 is formed with a combustion chamber recess 6 that is recessed in a substantially hemispherical shape. The combustion chamber recess 6 forms a combustion chamber 7 between the upper surface of the piston 5.

  A pair of intake ports 11 are opened on one side of the combustion chamber recess 6. Each intake port 11 extends from the combustion chamber recess 6 to one side wall of the cylinder head 3 and is open. A pair of exhaust ports 12 are opened on the other side of the combustion chamber recess 6. Each exhaust port 12 extends from the combustion chamber recess 6 to the other side wall of the cylinder head 3 and is open. An intake valve 13 and an exhaust valve 14 which are poppet valves for opening and closing the respective ports are provided at boundaries between the intake ports 11 and the exhaust ports 12 and the combustion chamber recess 6. A spark plug mounting hole 16 penetrating the cylinder head 3 up and down is formed in a central portion of the combustion chamber recess 6 and surrounded by each intake port 11 and each exhaust port 12. A spark plug 17 is inserted and fixed in the spark plug mounting hole 16.

  One edge (inner end) of the injector hole 19 is opened between the pair of intake ports 11 on one side edge of the combustion chamber recess 6. The injector hole 19 extends along a linear axis, and the other end (outer end) is opened on a side wall on one side of the cylinder head 3. The outer end of the injector hole 19 is disposed closer to the cylinder block 2 than the intake port 11 on one side wall. A mounting seat 21 that forms a plane perpendicular to the axis of the injector hole 19 is formed around the outer end of the injector hole 19. The injector hole 19 is a hole having a circular cross section, the inner end side is formed smaller in diameter than the outer end side, and the diameter continuously changes in the intermediate portion. As described above, the injector hole 19 is configured to penetrate the cylinder head 3 and communicate the combustion chamber 7 with the outside of the cylinder head 3.

  A fuel injection device (injector) 30 is inserted into the injector hole 19. The fuel injection device 30 is a device that extends along a predetermined axis A. When one end side along the axis A of the fuel injection device 30 is the front end and the opposite end is the base end, the fuel injection device 30 faces the combustion chamber 7 and the base end side extends from the injector hole 19 to the cylinder head 3. Is inserted into the injector hole 19 so as to protrude outward.

  As shown in FIG. 2, the fuel injection device 30 has a valve body 33 in which a fuel passage 32 is formed, a nozzle member 34 provided at the tip of the valve body 33, and can be advanced and retracted into the fuel passage 32. It has a received valve body 35, a solenoid 37 for driving the valve body 35, and a sensor 38 provided on the outer periphery of the tip of the valve body 33. A first resin portion 39 and a second resin portion (covering material) 40 are insert-molded on the outer surface of the valve body 33.

  The valve body 33 includes a first body 41, a second body 42, and a third body 43. The 1st-3rd bodies 41-43 are formed from the magnetic body which has electroconductivity. The first body 41 extends coaxially with the axis A of the fuel injection device 30, and has a small diameter portion 45, a tapered portion 46, and a large diameter portion 47 in this order from the distal end side, which is one end, to the proximal end side, which is the other end. ing. The small-diameter portion 45, the tapered portion 46, and the large-diameter portion 47 each have a circular cross section and are arranged coaxially with each other. The large-diameter portion 47 has a larger outer diameter than the small-diameter portion 45, and the tapered portion 46 gradually increases in outer diameter as it proceeds from the distal end side to the proximal end side. The first body 41 has a first hole 48 that extends coaxially with the axis A from the distal end to the proximal end. The first hole 48 has a larger inner diameter on the large diameter portion 47 side than on the small diameter portion 45 side.

  The second body 42 includes a cylindrical shaft portion 51 that extends coaxially with the axis A of the fuel injection device 30, and an outer peripheral surface of the shaft portion 51 that is a predetermined distance from the tip of the shaft portion 51. A disk-like flange portion 52 protruding outward in the radial direction. In the second body 42, the distal end of the shaft portion 51 is inserted into the large diameter portion 47 of the first body 41 and is coupled to the first body 41 coaxially. The insertion depth of the second body 42 with respect to the first body 41 is determined by the flange portion 52 of the second body 42 and the proximal end surface of the large-diameter portion 47 of the first body 41 coming into contact with each other. A second hole 53 is formed in the shaft portion 51 so as to penetrate from the base end to the tip end coaxially with the axis A. When the first and second bodies 41 and 42 are coupled to each other, the first and second holes 48 and 53 communicate with each other to form the fuel passage 32.

  The third body 43 includes a cylindrical tube portion 56 and an end wall portion 57 provided so as to close one end of the tube portion 56. An insertion hole 58, which is a through hole having a circular cross section that is coaxial with the cylindrical portion 56, is formed at the center of the end wall portion 57. The opening end side of the inner peripheral surface of the cylindrical portion 56 is enlarged in steps so that the flange portion 52 of the second body 42 can be received. The third body 43 is arranged such that the end wall portion 57 is on the tip side with respect to the cylindrical portion 56, the large-diameter portion 47 of the first body 41 is inserted into the insertion hole 58, and the third body 43 is inserted into the cylindrical portion 56. By inserting the flange portion 52 of the two bodies 42, the two bodies 42 are assembled coaxially with the first and second bodies 41, 42. When the flange portion 52 abuts on a step portion (not shown) formed on the inner surface of the cylindrical portion 56, the position of the third body 43 relative to the first and second bodies 41, 42 is determined. Thus, an annular solenoid chamber surrounded by the cylindrical portion 56, the end wall portion 57, and the flange portion 52 is formed on the outer peripheral side of the large diameter portion 47 of the first body 41. The first to third bodies 41 to 43 are joined to each other by welding at appropriate positions.

  3 and 4A, the nozzle member 34 has a cylindrical peripheral wall portion 61 and a bottom wall portion 62 that closes one end of the peripheral wall portion 61, and is formed in a cup shape. . In the nozzle member 34, the peripheral wall portion 61 is fitted into the opening end on the front end side of the first hole 48 so that the bottom wall portion 62 is disposed on the front end side with respect to the peripheral wall portion 61. The distal end portion of the peripheral wall portion 61 is welded to the distal end portion of the small diameter portion 45, and the nozzle member 34 is joined to the first body 41. The center portion of the bottom wall portion 62 swells in a hemispherical shape toward the distal end side, and the inner surface side (base end side) is recessed to form a valve seat 64. A plurality of injection holes 65 are formed in the central portion of the bottom wall portion 62 so as to penetrate the bottom wall portion 62.

  As shown in FIG. 2, the valve body 35 includes a rod 76 that extends in the first hole 48 along the axis A, and a diameter-expanded portion 77 formed in the rod 76. The enlarged diameter portion 77 has an outer diameter larger than the inner diameter at the end portion on the distal end side of the second hole 53 and can come into contact with the distal end surface of the shaft portion 51. The tip of the rod 76 has a shape that can be seated on a valve seat 64 formed on the nozzle member 34. The enlarged diameter portion 77 is formed with a plurality of fuel holes 71 extending in parallel with the axis A and passing through the enlarged diameter portion 77. As a result, the first hole 48 and the second hole 53 communicate with each other via the plurality of fuel holes 71. The valve body 35 is made of a magnetic material.

  A cylindrical spring seat 78 is press-fitted and fixed in the second hole 53. A first spring 79 that is a compression coil spring is interposed between the spring seat 78 and the enlarged diameter portion 77 of the valve body 35. The valve body 35 is urged toward the distal end side by the first spring 79. As a result, the tip of the rod 76 is seated on the valve seat 64 of the nozzle member 34 and blocks the first hole 48 and the injection hole 65.

  An annular solenoid 37 (coil) centered on the axis A is disposed in the solenoid chamber. Solenoid wires 83 are connected to both ends of the windings constituting the solenoid 37, respectively. The solenoid wiring 83 passes through a through hole formed in the flange portion 52 and is drawn out to the base end side outside the valve body 33. Most of the solenoid wires 83 in the longitudinal direction are bundled with each other and extend integrally.

  An O-ring groove 85 that is annularly recessed along the circumferential direction is formed on the outer peripheral proximal end side of the shaft portion 51. A flexible O-ring 86 is attached to the O-ring groove 85. A filter 87 for removing foreign matter from the fuel is mounted in the opening end on the proximal end side of the second hole 53.

  The sensor 38 is a sensor that detects the state of the combustion chamber 7, for example, a pressure sensor that detects the pressure in the combustion chamber 7, a temperature sensor that detects the temperature in the combustion chamber 7, and an oxygen concentration in the combustion chamber 7. It is a known sensor such as an oxygen concentration sensor. In the present embodiment, an example in which the sensor 38 is configured as a pressure sensor will be described.

  Although detailed illustration is omitted, the sensor 38 includes a case forming an outer shell and a piezoelectric element accommodated in the case. The outer shape of the sensor 38 is formed in a cylindrical shape with both ends opened. The outer shell of the sensor 38 is made of, for example, a metal material. As shown in FIGS. 3 and 4A, the sensor 38 has an inner hole 38B formed by an inner peripheral surface 38A having a circular cross section. The inner hole 38B is a through-hole, and the distal end of the small diameter portion 45 is inserted from the proximal end side. The small diameter portion 45 is tightly fitted in the inner hole 38 </ b> B, and the sensor 38 is attached to the outer peripheral tip of the small diameter portion 45.

  In a state where the sensor 38 is attached to the small diameter portion 45, the distal end portion of the sensor 38 extends to the distal end side (combustion chamber side) from the distal end surface 45 </ b> A of the small diameter portion 45. In other words, the tip surface 45A of the small diameter portion 45 is disposed inside the inner hole 38B of the sensor 38. As a result, as shown in FIGS. 4A and 4B, a corner 101 extending in an annular shape is formed by the inner peripheral surface 38 </ b> A of the sensor 38 and the tip surface 45 </ b> A of the small diameter portion 45.

  A locking portion 103 that protrudes radially inward is provided on the inner peripheral surface 38 </ b> A of the distal end portion of the sensor 38. In the present embodiment, the locking portion 103 extends in the circumferential direction along the inner peripheral surface 38A. The locking portion 103 may be formed integrally with the sensor 38, or may be formed by coupling an annular member 104 forming the locking portion 103 to the sensor 38.

  In the present embodiment, the locking portion 103 is formed from an annular member 104 that is a separate member from the sensor 38. The annular member 104 protrudes in a direction parallel to the axis of the main body portion 105 from the inner peripheral edge of the main body portion 105 and has an annular shape along the inner peripheral edge of the main body portion 105. And a wall 106 formed. The wall portion 106 has an inner surface formed on a circumferential surface centering on the axis of the main body portion 105 and an outer surface composed of a tapered surface inclined inward in the radial direction toward the protruding end.

  The annular member 104 is inserted coaxially into the inner hole 38B of the sensor 38 and contacts the inner peripheral surface 38A of the sensor 38 on the outer peripheral surface. At this time, the end surface on the front end side of the main body portion 105 is disposed so as to be substantially flush with the front end surface of the sensor 38. Moreover, the wall part 106 is arrange | positioned so that it may face the back | inner side of the inner hole 38B.

  The annular member 104 is coupled to the sensor 38 by welding or the like. The annular member 104 and the sensor 38 may be welded continuously or intermittently over the entire outer periphery of the annular member 104. The annular member 104 and the sensor 38 are welded before the pressure detection characteristic of the sensor 38 is determined. That is, the calibration operation of the sensor 38 is performed after welding. For this reason, even if stress due to thermal deformation accompanying welding of the annular member 104 and the sensor 38 remains in the sensor 38, the stress does not affect the detection system of the sensor 38. In the present embodiment, the distal end portion of the outer peripheral surface of the main body portion 105 and the distal end portion of the inner peripheral surface 38 </ b> A of the sensor 38 are welded over the entire circumference to form the welded portion 107.

  When the sensor 38 is mounted on the small diameter portion 45, the main body portion 105 and the wall portion 106 of the locking portion 103 extend to a position overlapping the tip surface 45 </ b> A of the small diameter portion 45 when viewed from the direction of the axis A. In the direction of the axis A, a seal member 108 is sandwiched between the distal end surface 45A of the small diameter portion 45 and the locking portion 103. The seal member 108 is formed of a member having flexibility and heat resistance, for example, a fluororesin such as polytetrafluoroethylene. As shown in FIG. 4B, the seal member 108 is formed in an annular shape having a square cross section when no load is applied. The seal member 108 is disposed along the corner 101 extending in an annular shape by the inner peripheral surface 38A of the sensor 38 and the tip surface 45A of the small diameter portion 45.

  As shown in FIG. 4A, the seal member 108 is compressed and deformed by the locking portion 103 and the distal end surface 45A of the small diameter portion 45 from the direction of the axis A, and the distal end surfaces of the locking portion 103 and the small diameter portion 45 are deformed. 45A and the inner peripheral surface 38A of the sensor 38 are in close contact with each other to cover the corner portion 101, and the gap between the inner peripheral surface 38A of the sensor 38 and the outer peripheral surface of the small diameter portion 45 is hermetically sealed. The wall portion 106 of the locking portion 103 suppresses the radially inward bulging of the seal member 108 that is deformed by receiving a compressive force, and maintains the seal member 108 at the corner portion 101. Further, the wall 106 covers the radially inner portion of the seal member 108 to reduce the exposed area of the seal member 108 to the combustion chamber 7, and contact between the seal member 108 and the hot gas in the combustion chamber 7. Reduce the area. Thereby, the seal member 108 is prevented from being deteriorated by heat. The protruding end of the wall portion 106 is preferably close to the distal end surface 45A of the small diameter portion 45, and may contact the distal end surface 45A of the small diameter portion 45.

  In the present embodiment, the nozzle member 34 protrudes further toward the tip side than the tip surface 45 </ b> A of the small diameter portion 45, and a side wall by the outer surface of the peripheral wall portion 61 of the nozzle member 34 is formed at the boundary between the nozzle member 34 and the small diameter portion 45. Yes. The peripheral wall portion 61 of the nozzle member 34 is in contact with the seal member 108 and suppresses the expansion of the seal member 108 radially inward.

  As shown in FIG. 3, the outer peripheral proximal end portion of the sensor 38 is a connection portion 88 whose outer diameters are reduced in steps. A sensor wiring 91 for transmitting an electrical signal of the sensor 38 extends from the connection portion 88. The sensor wiring 91 is a wiring such as a known flexible printed circuit board (FPC).

  A seal device 92 is coupled to the proximal end portion of the sensor 38. The sealing device 92 has a cylindrical shape and includes a collar member 93 through which the small diameter portion 45 is inserted. The collar member 93 is formed with a receiving portion 96 whose diameter is increased stepwise at the inner circumferential tip. The connection portion 88 of the sensor 38 enters the reception portion 96, and the reception portion 96 covers the outer surface of the connection portion 88. A collar 109 is provided with a welded portion 109 that is airtightly welded to the sensor 38. The collar member 93 and the sensor 38 are welded before the pressure detection characteristics of the sensor 38 are determined.

  On the outer peripheral portion of the collar member 93, two seal grooves 94 extending in the circumferential direction and forming an annular shape are formed. An annular seal member (chip seal) 95 is mounted in each seal groove 94. The seal device 92 is also attached to the outer peripheral tip of the small diameter portion 45 in a state where the sensor 38 is attached to the tip of the small diameter portion 45.

  A procedure for assembling the sensor 38, the seal member 108, and the seal device 92 to the fuel injection device 30 will be described. First, the annular member 104 and the sealing device 92 that form the locking portion 103 are welded to the sensor 38 to form a unit. The sensor wiring 91 passes through the inside of the collar member 93 and is pulled out from the base end portion of the collar member 93. In this state, the detection characteristics of the sensor 38 are determined. The tip of the small diameter portion 45 is inserted into the unitized sensor 38 so as to pass through the sealing device 92, and is tightly fitted. At this time, as shown in FIG. 4B, the seal member 108 is disposed between the distal end surface 45A of the small diameter portion 45 and the engaging portion 103, and the seal member 108 is disposed between the distal end surface 45A and the engaging portion 103. Hold it. The sealing device 92 is coupled to the small diameter portion 45 via a sensor 38 coupled to the small diameter portion 45 by an interference fit.

  As shown in FIG. 2, a first receiving groove 98 extending in the direction of the axis A over the small diameter portion 45, the taper portion 46 and the large diameter portion 47 is recessed in the outer surface of the first body 41. The first receiving groove 98 is formed deeper in the portion of the small diameter portion 45 facing the collar member 93 than in other portions. In the deep part of the first receiving groove 98, the end portion on the distal end side extends to a position corresponding to the receiving portion 96, and the end portion on the proximal end side extends further to the proximal end side than the collar member 93.

  The sensor wiring 91 extends from the connection portion 88 of the sensor 38 through the first receiving groove 98 to the proximal end side of the sealing device 92 and reaches the proximal end portion of the small diameter portion 45. The surface of the sensor wiring 91 is covered with, for example, an epoxy-based adhesive and bonded to the surface of the valve body 33.

  As shown in FIG. 2, the first resin portion 39 is molded on the outer surface of the shaft portion 51, and the second resin portion 40 is formed on the outer surfaces of the first body 41, the second body 42, and the first resin portion 39. Is molded. The first resin portion 39 covers a portion extending from the flange portion 52 of the shaft portion 51 to the proximal end side, and protrudes laterally to form the connector portion 110. A terminal is provided inside the connector part 110. Sensor wiring 91 and solenoid wiring 83 extending through the first and second resin portions 39 and 40 are connected to the terminals.

  As shown in FIG. 1, the fuel injection device 30 configured as described above is arranged such that the first body 41 is located in the injector hole 19 and the third body 43 is located outside the injector hole 19. The An annular tolerance ring 111 is disposed coaxially with the injector hole 19 on the mounting seat 21 disposed at the outer peripheral edge of the injector hole 19. The tolerance ring 111 has conductivity and has a tapered surface so that the inner portion can contact the inclined surface 99 of the third body 43. Thus, the valve body 33 is electrically connected to the cylinder head 3 via the tolerance ring 111 and grounded.

  The fuel injection device 30 is arranged so that the tip of the first body 41 to which the nozzle member 34 is attached and the sensor 38 face the combustion chamber 7. In the sealing device 92, each sealing member 95 abuts on the inner surface of the injector hole 19 and seals between the injector hole 19 and the collar member 93. The collar member 93 is hermetically coupled to the sensor 38, and the sensor 38 and the small diameter portion 45 of the valve body 33 are hermetically sealed by the seal member 108. As shown in FIG. 1, the base end portion of the shaft portion 51 that constitutes the base end portion of the valve body 33 is inserted into a connection pipe 113 provided in a delivery pipe 112 that supplies fuel to each fuel injection device 30. Connected. The O-ring 86 seals between the shaft portion 51 and the connection pipe 113. As a result, fuel is supplied from the delivery pipe 112 to the fuel passage 32 including the first hole 48 and the second hole 53 via the connection pipe 113.

  A connector (not shown) of a harness extending from the ECU that drives and controls the fuel injection device 30 is connected to the connector portion 110, and a sensor signal from the sensor 38 is transmitted to the ECU and a drive signal from the ECU to the solenoid wiring 83. Is transmitted.

  The effect of the fuel injection device 30 configured as described above will be described. In the present embodiment, since the gap between the inner peripheral surface 38A of the sensor 38 and the outer surface of the small diameter portion 45 of the valve body 33 is sealed by the seal member 108, there is no need to seal the gap by welding, which results from the heat of welding. The detection characteristics of the sensor 38 are not changed. The locking portion 103 that holds the seal member 108 between the distal end surface 45A of the small-diameter portion 45 has a wall portion 106 on the inner peripheral edge, and restricts the movement of the seal member 108 that is deformed by receiving a compressive force. The seal member 108 is maintained at the corner 101 where the gap between the sensor 38 and the small diameter portion 45 is opened, and can be reliably sealed.

  Further, since the wall 106 covers the inner peripheral portion of the seal member 108, the exposed area of the seal member 108 to the combustion chamber 7 is reduced, and contact between the seal member 108 and the high-temperature gas in the combustion chamber 7 is suppressed. . Thereby, deterioration of the seal member 108 is suppressed.

  Hereinafter, second to fifth embodiments in which a part of the above embodiment is modified will be described. The fuel injection devices 200, 300, 400, and 500 according to the second to fifth embodiments are partially different from the fuel injection device 30 according to the first embodiment, and most other configurations are the same. Therefore, in the description of the fuel injection devices 200, 300, 400, and 500 according to the following second to fifth embodiments, the same components as those of the fuel injection device 30 according to the first embodiment are denoted by the same reference numerals. Description is omitted.

(Second Embodiment)
As shown in FIG. 5, in the fuel injection device 200 according to the second embodiment, the groove portion 201 (notch) is formed in the outer peripheral portion (base portion) of the portion facing the distal end surface 45 </ b> A side of the main body portion 105 of the locking portion 103. Has been. The groove portion 201 is formed from the end surface of the main body portion 105 facing the front end surface 45 </ b> A to the outer peripheral surface, and the corner portion of the main body portion 105 is notched. In other words, the groove 201 can be said to be an enlarged diameter part in which the outer diameter of the main body part 105 is increased.

  By providing the groove portion 201 on the outer peripheral side of the main body portion 105, the seal member 108 is guided to the groove portion 201 side when being sandwiched between the locking portion 103 and the distal end surface 45 </ b> A, and is maintained at the corner portion 101. The contact pressure between the inner peripheral surface 38A and the front end surface 45A of the sensor 38 can be kept high. Thereby, the sealing by the sealing member 108 is further ensured.

(Third embodiment)
As shown in FIG. 6A, in the fuel injection device 300 according to the third embodiment, a notch 301 is formed in the outer peripheral portion of the portion facing the tip end face 45A side of the seal member. By forming the notch 301, the seal member 108 has a smaller width in the direction of the axis A in the outer peripheral portion than in the inner peripheral portion.

  By providing the notch 301 on the outer peripheral side of the seal member 108, the compression pressure of the outer peripheral portion is higher than that of the inner peripheral portion when the seal member 108 is sandwiched between the locking portion 103 and the tip surface 45 </ b> A. Becomes smaller. Therefore, the seal member 108 escapes to the outer peripheral side and is maintained at the corner portion 101, so that the contact pressure between the inner peripheral surface 38A and the front end surface 45A of the sensor 38 can be maintained at a high level. Thereby, the sealing by the sealing member 108 is further ensured.

  As a modification of the third embodiment, as shown in FIG. 6B, a notch 302 may be formed in the outer peripheral portion of the portion facing the main body 105 side of the seal member 108.

(Fourth embodiment)
As shown in FIG. 7, the front end surface 45A of the small diameter portion 45 according to the fourth embodiment is formed as an inclined surface that is inclined so as to advance toward the front end side as it proceeds inward in the radial direction. According to this configuration, the inclined front end surface 45A restricts the seal member 108 sandwiched between the locking portion 103 and the front end surface 45A, and the expansion of the seal member 108 radially inward is suppressed. Can do.

(Fifth embodiment)
As shown in FIG. 8A, in the fuel injection device 500 according to the fifth embodiment, the wall portion 506 of the locking portion 103 is formed to be thin and flexible. The wall portion 506 protrudes from the inner peripheral edge of the annularly formed main body portion 105 toward the distal end surface 45A side of the small diameter portion 45 in parallel with the axis of the main body portion 105, and in the circumferential direction along the inner peripheral edge of the main body portion 105. It extends and is formed in an annular shape. The front end portion 506A of the wall portion 506 is bent and radially inward (on the axis A side) and on the front end surface 45A side of the small diameter portion 45 before the sensor 38 is attached to the small diameter portion 45 of the first body 41. It extends.

  As shown in FIG. 8B, in a state where the sensor 38 is mounted on the small diameter portion 45 of the first body 41, the wall portion 506 is disposed so as to cover the inner peripheral portion of the seal member 95, and its distal end portion 506A. Comes into contact with the tip surface of the nozzle member 34 while being elastically deformed. The restoring force of the wall 506 acts to push the tip 506A toward the nozzle member 34, and the tip 506A is in close contact with the nozzle member 34. A contact portion between the tip 506A of the wall 506 and the nozzle member 34 extends in the circumferential direction around the axis A and is formed in an annular shape. As a result, the seal member 95 is covered with the main body portion 105 and the wall portion 506 of the locking portion 103 and is isolated from the combustion chamber. As a result, exposure of the seal member to the high temperature gas in the combustion chamber 7 is avoided, and deterioration of the seal member 108 is suppressed.

  In the fifth embodiment, the tip 506A of the wall 506 is in contact with the tip of the nozzle member 34. However, in other embodiments, the radial width of the seal member is reduced, and the tip of the wall 506 is reduced. 506A may be configured to abut on the tip surface 45A of the small diameter portion 45. The wall portion 506 only needs to contact the member constituting the tip portion of the valve body 33 and cover the seal member 108.

  Although the description of the specific embodiment is finished as described above, the present invention is not limited to the above embodiment and can be widely modified. For example, in other embodiments, the locking portion 103 may omit the wall portion 106. Further, a cut portion may be formed on the inner peripheral portion of the end surface on the side opposite to the front end surface 45A of the main body portion 105. By providing the cut portion, interference between the locking portion 103 and the fuel injected from the injection hole 65 can be avoided, and the fuel spray angle can be set wider.

DESCRIPTION OF SYMBOLS 1 ... Internal combustion engine 3 ... Cylinder head (internal combustion engine main body), 7 ... Combustion chamber, 19 ... Injector hole, 30 ... Fuel injection apparatus, 33 ... Valve body, 34 ... Nozzle member, 35 ... valve body, 38 ... sensor, 38A ... inner peripheral surface, 38B ... inner hole, 41 ... first body, 42 ... second body, 43. 3rd body, 45 ... small diameter part, 45A ... tip surface, 61 ... circumferential wall part, 62 ... bottom wall part, 65 ... injection hole, 92 ... sealing device, 93 ... collar member, 95 ... seal member, 101 ... corner, 103 ... locking part, 104 ... annular member, 105 ... main body part, 106 ... wall part, 108 ... Seal member, A ... Axis

Claims (7)

A valve body inserted into an injector hole formed in the internal combustion engine body and having a tip facing the combustion chamber;
A sensor that is formed in a cylindrical shape, the tip of the valve body is inserted inside, and supported on the outer periphery of the valve body;
An annular seal member that seals a gap between the outer surface of the valve body and the inner surface of the sensor;
A tip portion disposed on the combustion chamber side of the sensor has a locking portion that extends toward the combustion chamber side than the tip portion of the valve body and protrudes on the inner side of the valve body on the inner surface thereof.
The seal member is disposed at a corner formed by the inner surface of the sensor and the outer peripheral portion of the distal end surface of the valve body, and is sandwiched between the locking portion and the valve body ,
The locking portion has a wall portion extending to a tip end side of the valve body at a protruding end thereof,
The fuel injection device according to claim 1, wherein the wall portion is flexible and abuts against a distal end surface of the valve body while being elastically deformed .   The seal member is flexible, receives a compressive force from the axial direction of the valve body by the locking portion and the valve body, and is in close contact with the sensor and the valve body. The fuel injection device according to claim 1.   3. The fuel injection device according to claim 1, wherein the locking portion extends in a circumferential direction centering on an axis of the valve body, and is formed in an annular shape. The locking portion and the wall portion extend in a circumferential direction around the axis of the valve body, and are formed in an annular shape.
The contact part of the said wall part and the front end surface of the said valve body is formed in the cyclic | annular form centering on the axis line of the said valve body, The Claim 1 characterized by the above-mentioned. Fuel injectors. The said locking part has a groove part recessed in the direction which opposes the said front end surface side of the said valve body in the part which faces the said front end surface side of the said valve body of the base part. The fuel injection device according to any one of claims 4 to 5. The fuel injection device according to any one of claims 1 to 5 , wherein the seal member has a smaller width in an axial direction of the valve body in an outer peripheral side portion than in an inner peripheral side portion. . The fuel injection device according to any one of claims 1 to 6 , wherein a distal end surface of the valve body is formed as an inclined surface with a central side protruding from an outer peripheral side.

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