JP2018123728A - Fuel injection valve - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide a fuel injection valve which reduces the possibility of lowering elastic force to be imparted to an electric actuator.SOLUTION: The fuel injection valve includes a control valve, an electric unit, a holder body 40, a stopper, a disc spring 602, an adjustment member 603, and an insertion member 72. The adjustment member 603 in a shaped having a through-hole 603a passing therethrough in the axial direction is arranged adjacent to the disc spring 602 in the axial direction for adjusting the elastic deformation amount of the disc spring 602 to be a desired value. The insertion member 72 is arranged inside an inner periphery side edge 602a of the disc spring 602 while being inserted through the through-hole 603a. A diameter d1 of a disc spring opposite face 72c as a portion opposite to the inner periphery edge 602a, of the outer peripheral face of the insertion member 72, is larger than a diameter d2 of an adjustment member opposite face 72d as a portion opposite to the wall face of the through-hole 603a, of the outer peripheral face of the insertion member 72.SELECTED DRAWING: Figure 3

Description

  The present invention relates to a fuel injection valve that controls fuel injection and injection stop by opening and closing a control valve with an electric actuator.

  Patent Document 1 discloses a fuel injection valve that controls fuel injection and injection stop by controlling the back pressure of a needle that opens and closes a nozzle hole by opening and closing a control valve by an electric actuator having a solenoid coil or the like. It is disclosed. The back pressure is the fuel pressure applied to the needle on the valve closing side. When the control valve is opened, the back pressure decreases and the needle opens to inject fuel from the nozzle hole. Is done.

  The electric actuator described above is housed inside the body while being sandwiched between the stopper and the disc spring in the axial direction, and the elastic force of the disc spring is applied as a pressing force for pressing the electric actuator against the stopper. An adjusting member for adjusting the amount of elastic deformation of the disc spring to a desired amount is disposed between the electric actuator and the disc spring. The adjustment member has a shape having a through hole penetrating in the axial direction, and an insertion member is inserted into the through hole and the center hole of the disc spring. Thereby, the movement of the disc spring and the adjustment member in the radial direction is restricted by the insertion member, and the disc spring and the adjustment member are positioned in the radial direction.

JP 2010-174822 A

  Here, when the adjustment member is displaced in the radial direction by the amount of the insertion clearance provided between the adjustment member and the insertion member, the insertion clearance on the other side is reduced by the amount that the insertion clearance on one side in the radial direction is reduced. growing. Then, the inner peripheral edge of the disc spring may enter the insertion clearance on the larger side. In this case, the disc spring is inclined from the normal direction, and the expected elastic deformation amount cannot be obtained, so that the elastic force (pressing force) is reduced. As a result, the knowledge that the vibration of the electric actuator due to the vibration of the internal combustion engine is larger than expected and the lead wire for supplying power to the electric actuator is broken, and the risk of damage to each part of the fuel injection valve is increased. The inventor got.

  The present invention has been made in view of the above problems, and an object of the present invention is to provide a fuel injection valve in which the possibility that the elastic force applied to the electric actuator is reduced is reduced.

  The invention disclosed herein employs the following technical means to achieve the above object. Note that the reference numerals in parentheses described in the claims and in this section indicate the correspondence with specific means described in the embodiments described later, and do not limit the technical scope of the invention. .

The disclosed invention
A control valve (65) for controlling fuel injection and injection stop from the nozzle hole (22) by opening and closing the fuel passage (53a);
An electric unit (U) including an electric actuator (60) for opening and closing the control valve;
A body (40) for accommodating the electric unit therein;
A stopper (601) for restricting the electric unit from moving to one side in the axial direction of the body;
It has a shape that extends annularly around the axial direction, and the annular inner peripheral edge (602a) and outer peripheral edge (602b) are in different positions in the axial direction, and exerts an elastic force that presses the electric unit against the stopper A disc spring (602) to perform,
An adjustment member (603) which has a through hole (603a) penetrating in the axial direction, is arranged adjacent to the disc spring in the axial direction, and adjusts the elastic deformation amount of the disc spring to a desired value;
An insertion member (72) arranged to be inserted into the inner peripheral side edge and the through hole;
With
The diameter of the disc spring facing surface (72c), which is the portion facing the inner peripheral edge of the outer peripheral surface of the insertion member, is the adjustment member facing surface (the portion facing the wall surface of the through hole) of the outer peripheral surface of the insertion member. The fuel injection valve is larger than the diameter of 72d).

  Based on the knowledge described above, in the above invention, the diameter of the disc spring facing surface of the insertion member is set larger than the diameter of the adjusting member facing surface. Therefore, even when the adjustment member is displaced in the radial direction by the amount of the insertion clearance, the inner circumferential edge moves in the radial direction toward the clearance on the larger side (the other side described above). The side edge is suppressed by contacting the conical spring facing surface. Therefore, since it can suppress that an inner peripheral edge enters into a through-hole, it can suppress that an elastic force (pressing force) becomes smaller than expected. Therefore, the vibration of the electric unit can be prevented from becoming larger than expected, and the risk of damage to each part of the fuel injection valve, such as disconnection of the lead wire, can be reduced.

1 is an overall cross-sectional view of a fuel injection valve according to a first embodiment of the present invention. Sectional drawing which expanded the part of the electric unit among FIG. Sectional drawing which expanded the part of the disc spring among FIG. Sectional drawing perpendicular | vertical with respect to an axial direction in the enlarged diameter part of the insertion member shown in FIG. FIG. 4 is an exploded view of a disc spring, an insertion member, and an adjustment member shown in FIG. 3. Sectional drawing of the fuel injection valve as a comparative example with respect to this invention. FIG. 7 is a cross-sectional view showing a state in which all of a plurality of disc springs are displaced in the radial direction in the structure of the comparative example shown in FIG. 6. FIG. 7 is a cross-sectional view showing a state in which some of the plurality of disc springs are displaced in the radial direction in the structure of the comparative example shown in FIG. 6. The graph which shows the test result which implemented the vibration test with respect to the fuel injection valve as a comparative example. The side view of the insertion member with which the fuel injection valve concerning 2nd Embodiment of this invention is provided.

  Hereinafter, a plurality of modes for carrying out the invention will be described with reference to the drawings. In each embodiment, portions corresponding to the matters described in the preceding embodiment may be denoted by the same reference numerals and redundant description may be omitted. In each embodiment, when only a part of the configuration is described, the other configurations described above can be applied to other portions of the configuration.

(First embodiment)
Hereinafter, an embodiment in which a fuel injection valve according to the present invention is applied to a common rail fuel injection system of a diesel engine (internal combustion engine) mounted on a vehicle will be described with reference to the drawings.

  A fuel injection valve 10 shown in FIG. 1 is inserted and mounted in a cylinder head (not shown) of an engine, and directly injects fuel supplied from a common rail into each cylinder of the engine. The fuel injection valve 10 includes a nozzle body 20, a needle 30, a holder body 40, an orifice plate 50, an electric unit U, and the like.

  The nozzle body 20 is fixed to the lower side (injection hole side) of the holder body 40 through the orifice plate 50 by the retaining nut 11. The nozzle body 20 is formed with a guide hole 21 that slidably accommodates the needle 30 and an injection hole 22 that injects fuel when the needle 30 is opened (lifted).

  The guide hole 21 is drilled from the upper end surface of the nozzle body 20 toward the tip of the nozzle body 20, and a high-pressure passage 23 that guides high-pressure fuel to the injection hole 22 through a gap between the inner peripheral surface of the guide hole 21 and the outer peripheral surface of the needle 30. Is formed. The high-pressure passage 23 (guide hole 21) is connected to a high-pressure passage 51 formed in the orifice plate 50 with an upstream end opened to the upper end surface of the nozzle body 20. Then, when the seat surface formed at the tip of the needle 30 is seated on the seating surface formed on the inner peripheral surface of the nozzle body 20, the needle 30 blocks and blocks the high-pressure passage 23 leading to the nozzle hole 22.

  A cylindrical spring pedestal 25 is press-fitted and fixed in the guide hole 21, and the needle 30 is closed in the valve closing direction (downward in FIG. 1) between the lower end surface of the spring pedestal 25 and the upper end surface of the needle 30. A spring 26 to be pressed is arranged. A back pressure chamber 27 is formed on the inner peripheral surface of the spring pedestal 25 to apply high pressure fuel pressure as a back pressure to the upper end surface of the needle 30. This back pressure biases the needle 30 in the valve closing direction (downward in FIG. 1).

  The holder body 40 corresponds to a body that houses the electric unit U therein. A pipe joint 41 that protrudes in a direction intersecting with the axial direction C1 (vertical direction in FIG. 1) of the holder body 40 is provided at a portion of the holder body 40 that is located on the upper end side (reverse injection hole side) of the electric unit U. Is provided. High-pressure fuel is supplied from the common rail through a fuel pipe (not shown) connected to the pipe joint 41.

  Inside the holder body 40, a high-pressure passage 42 for guiding the high-pressure fuel introduced into the pipe joint 41 to the high-pressure passage 23 of the nozzle body 20 through the high-pressure passage 51 of the orifice plate 50, and the electric unit U are inserted and arranged. An insertion hole 43 and the like are formed. The high pressure passage 42 and the insertion hole 43 have a shape extending in the axial direction C1 (vertical direction in FIG. 1) of the fuel injection valve 10.

  Regarding the arrangement layout of the electric unit U with respect to the holder body 40, in the present embodiment, the electric unit U and the high-pressure passage 42 are laid out in a direction perpendicular to the axial direction C1 of the holder body 40 (the left-right direction in FIG. 1). Yes. Therefore, the axial center position of the electric unit U, that is, the radial position of the one-dot chain line shown as the axial direction C2 of FIG. 1 with respect to the axial center position of the holder body 40, that is, the radial position of the one-dot chain line shown as the axial direction C1 of FIG. , In different positions.

  The “axial direction” referred to in the present specification is the longitudinal direction of the holder body 40 and the nozzle body 20, and is also the insertion direction of the fuel injection valve 10 inserted and mounted in the cylinder head.

  As shown in FIG. 2, the orifice plate 50 is formed with an inflow passage 52 through which high pressure fuel flows from the high pressure passage 51 to the back pressure chamber 27 and an outflow passage 53 through which the high pressure fuel flows out from the back pressure chamber 27 to the low pressure side. Yes. An inlet orifice 52a is formed in the inflow passage 52, and an outlet orifice 53a is formed in the outflow passage 53.

  The electric unit U includes an electric actuator 60, an internal terminal 67, a housing main body 68, and the like described below. The electric actuator 60 includes a stator 63 having an electromagnetic coil 62 wound around a resin bobbin 61, an armature 64 that moves in opposition to the stator 63, and the like. The armature 64 accommodates a ball valve 65 (control valve) that moves integrally with the armature 64 and opens and closes the outlet orifice 53a (fuel passage).

  When the electromagnetic coil 62 is energized, the armature 64 is magnetized by the generated magnetic flux and is attracted to the stator 63 by the magnetic attraction force to move. Further, the spring 66 disposed in the central portion of the stator 63 urges the armature 64 in the direction in which the ball valve 65 is closed (downward in FIG. 2).

  A portion of the insertion hole 43 of the holder body 40 located below the stator 63 functions as a valve chamber 43a for accommodating the ball valve 65, and the armature 64 is accommodated together with the ball valve 65 in the valve chamber 43a. Yes. The valve chamber 43a is filled with low-pressure fuel that has flowed out of the outlet orifice 53a.

  An annular groove 54 and a groove 55 extending radially outward from the groove 54 are formed on the upper end surface of the orifice plate 50, and fuel in the valve chamber 43 a passes through the grooves 54, 55 to hold the holder body. 40 communicates with a low-pressure passage 44 formed in 40. The low pressure passage 44 is formed to extend in the axial direction C1 in parallel with the high pressure passage 42. An annular groove 56 is formed in the lower end surface of the orifice plate 50, and the high pressure passage 51 of the orifice plate 50 and the high pressure passage 23 of the nozzle body 20 communicate with each other through the groove 56. The high-pressure passage 42 and the electric unit U are arranged so as to be aligned in a direction perpendicular to the axial direction C1 of the holder body 40 (left-right direction in FIG. 1).

  An internal terminal 67 is attached to the electric actuator 60. Specifically, one end 67 a of the internal terminal 67 is inserted into the bobbin 61 and electrically connected to the electromagnetic coil 62. In the state of being electrically connected in this way, the internal terminal 67 is primarily molded together with the bobbin 61 and the electromagnetic coil 62 by the resin material 60a. Thereby, the internal terminal 67 is attached to and integrated with the electric actuator 60.

  A resin housing body 68 is attached to a portion of the electric actuator 60 opposite to the armature 64. The housing body 68 is formed in a substantially cylindrical shape extending in the axial direction C2 (see FIG. 1) of the electric unit U. The housing main body 68 is formed with through holes 68a penetrating both end surfaces of the cylinder. A part of the internal terminal 67 is inserted and arranged in the through hole 68a, and the housing body 68 holds the internal terminal 67 in an insulated state.

  Between the housing main body 68 and the internal terminal 67, an internal seal member 69, which is a rubber O-ring, is disposed. An outer seal member 73 that is a rubber O-ring is disposed between the outer peripheral surface of the housing body 68 and the inner peripheral surface of the holder body 40.

  The electric unit U includes a primary molded product having an internal terminal 67, a bobbin 61, an electromagnetic coil 62, and a resin material 60a. In the state where the stator 63 (iron core portion) is inserted into the primary molded product and the internal terminal 67 is inserted into the through hole 68a of the housing main body 68, the housing main body 68 is fixed together with the primary molded product by the resin material 60b. Next molded. Thereby, the housing main body 68 is attached to and integrated with the electric actuator 60 together with the internal terminal 67.

  A resin-made housing head 71 is connected to a cylindrical end surface of the housing main body 68 opposite to the electric actuator 60. For this connection, heat welding or an adhesive may be used, but the housing main body 68 and the housing head 71 may be integrally molded with resin. The housing head 71 is formed in a substantially cylindrical shape arranged coaxially with the housing body 68.

  Polyphenylene sulfide (PPS) is used as the material of the housing head 71 and the housing body 68. PPS is a thermoplastic crystalline plastic that can secure a sufficient compressive strength against the pressing force (elastic force) of the disc spring 602, which will be described later, and is excellent in swelling resistance and creep strength.

  An insertion hole 71 a into which the other end 67 b of the internal terminal 67 is inserted is formed in the cylindrical end surface of the housing head 71 on the housing body 68 side. Further, an insertion hole 71b is formed in the opposite end of the cylinder, and an insertion member 72 for holding the lead wire 46b is inserted into the insertion hole 71b.

  A resin connector housing 46 (see FIG. 1) is attached to the upper part of the holder body 40 on the side opposite to the injection hole, and this connector housing 46 holds a connector terminal 46a to which power is supplied from the outside. The electric power supplied from the connector terminal 46 a is supplied to the electromagnetic coil 62 through the lead wire 46 b and the internal terminal 67.

  As shown in FIGS. 2 to 4, the insertion member 72 includes a columnar base 721 extending in the axial direction C <b> 2, a diameter-enlarged portion 722 that expands radially from the base 721, and a lower end of the base 721 in the axial direction C <b> 2. And a pin 723 extending.

  A plurality of pins 723 are provided and are inserted into the support holes of the housing body 68. This prevents the insertion member 72 from rotating relative to the housing body 68 around the axial direction C2 and allows the insertion member 72 to move relative to the housing body 68 in the radial direction. Is prevented. Further, the insertion member 72 is disposed so that the lower end surface of the base 721 contacts the housing head 71. This prevents the insertion member 72 from moving to the opposite side of the connector housing 46 in the axial direction C2.

  Returning to the description of FIG. 2, a cylindrical stopper 601 is disposed in the valve chamber 43a. The stopper 601 restricts the electric unit U from moving to one side in the axial direction C2 (the lower side in FIG. 2). The stopper 601 is in contact with the upper end surface of the orifice plate 50 and the lower end surface of the stator 63, so that the separation distance between the orifice plate 50 and the stator 63 in the axial direction C2 becomes the length of the stopper 601 in the axial direction C2. Stipulate. As a result, the size of the air gap between the upper end surface of the armature 64 and the lower end surface of the stator 63 when not energized depends on the accuracy of the axial dimension C2 length of the stopper 601, and the air gap is set to a desired value. Dimensioning can be specified with high accuracy.

  A cylindrical adjustment member 603 is disposed on the upper end surface of the electric unit U, and a disc spring 602 is disposed on the upper end surface of the adjustment member 603. That is, the housing head 71, the adjustment member 603, and the disc spring 602 are disposed adjacent to the axial direction C2. The upper end surface of the disc spring 602 abuts on the holder body 40, and the disc spring 602 is disposed between the holder body 40 and the adjustment member 603 and elastically deformed in the axial direction C2. The elastic force generated by the disc spring 602 is applied to the electric unit U via the adjusting member 603, and the electric unit U is pressed against the stopper 601 by the applied elastic force.

  As the material of the adjusting member 603, a metal is used so as to ensure a sufficient compressive strength against the pressing force (elastic force) of the disc spring 602. Since the pressing force is not applied to the insertion member 72, a material (for example, resin) having a lower compressive strength than that of the adjustment member 603 is used as the material of the insertion member 72. Resin is used for the material of the insertion member 72, but resin polyphenylene sulfide (PPS) excellent in swelling resistance and creep strength may be employed, and for example, phenol resin may be used. The materials of the insertion member 72, the adjustment member 603, and the housing head 71 are not limited to polyphenylene sulfide, and a metal may be used.

  As shown in FIGS. 3 and 5, the disc spring 602 has a shape that extends in an annular shape around the axial direction C2, and a shape in which the annular inner peripheral edge 602a and the outer peripheral edge 602b are in different positions in the axial direction C2. It is. In other words, in the cross-sectional shape shown in FIG. 5, the shape is inclined with respect to the vertical direction of the axial direction C2 (the left-right direction in FIG. 5). In the example illustrated in FIG. 3, the inner peripheral edge 602 a is arranged in a direction positioned closer to the adjustment member 603 than the outer peripheral edge 602 b.

  In addition, a plurality of disc springs 602 are arranged in an axial direction (stacked arrangement), and all the disc springs 602 are arranged in the same direction. Of the plurality of disc springs 602, the inner peripheral edge 602 a of the disc spring 602 adjacent to the adjustment member 603 contacts the adjustment member 603, and the outer peripheral side edge 602 b of the disc spring 602 adjacent to the holder body 40 contacts the holder body 40. Therefore, the plurality of disc springs 602 are elastically deformed with the inner peripheral edge 602 a that contacts the adjustment member 603 and the outer peripheral edge 602 b that contacts the holder body 40 as fulcrums. The greater the elastic deformation, the shorter the axial direction C2 length of the disc spring 602 and the larger the outer diameter, and the inner diameter D3 (see FIG. 5) remains the same.

  The elastic deformation amount of the disc spring 602 is defined by the axial dimension L3 (see FIG. 5) of the adjustment member 603. Therefore, the elastic deformation amount is adjusted to a desired value by selecting the adjustment member 603 having the axial dimension L3 that provides the desired elastic deformation amount, and the pressing force against the electric unit U is adjusted.

  The adjustment member 603 has a shape having a through hole 603a that penetrates in the axial direction C2, and the disc spring 602 has a shape that extends in an annular shape around the axial direction C2. The insertion member 72 is inserted and disposed inside the inner peripheral edge 602 a, that is, the center hole 602 c of the disc spring 602 and the through hole 603 a of the adjustment member 603. As shown in FIG. 3, the disc spring 602 is inserted into the enlarged diameter portion 722 of the insertion member 72, and the adjustment member 603 is inserted into a portion of the base portion 721 that is located on the housing head 71 side with respect to the enlarged diameter portion 722. Is done. In the following description, the portion of the outer peripheral surface of the insertion member 72 that faces the inner peripheral surface of the disc spring 602 is referred to as a disc spring facing surface 72c, and the portion that faces the inner peripheral surface of the adjusting member 603 is the adjusting member facing surface. 72d.

  The dimensional relationship among the parts of the disc spring 602, the insertion member 72, and the adjustment member 603 is set as follows. That is, the diameter d1 of the disc spring facing surface 72c is larger than the diameter d2 of the adjusting member facing surface 72d and larger than the inner diameter D4 of the through hole 603a of the adjusting member 603. The inside diameter D3 of the disc spring 602 is larger than the diameter d1 of the disc spring facing surface 72c, and the inside diameter D4 of the adjusting member 603 is larger than the diameter d2 of the adjusting member facing surface 72d. In addition, the axial dimension L <b> 2 of the enlarged diameter portion 722 is larger than the axial dimension L <b> 1 of the inner peripheral surface of the disc spring 602.

  The radial clearance between the inner peripheral edge 602a of the disc spring 602 and the disc spring facing surface 72c is smaller than the radial clearance between the inner peripheral surface of the adjusting member 603 and the adjusting member facing surface 72d. When the adjustment member 603 is displaced to one side (for example, the right side in FIG. 3) by the clearance in the radial direction, the clearance on the one side is increased by the amount that the clearance on the other side (for example, the left side in FIG. 3) is reduced. Thus, even in the state where the clearance on one side is increased, the diameter d1 of the conical spring facing surface 72c and the size of the clearance so that the increased clearance is covered with the enlarged diameter portion 722. Is set.

  These clearances are gaps necessary for the assembly operator to insert the adjustment member 603 and the disc spring 602 into the insertion member 72. The radial clearance between the outer peripheral edge 602b of the disc spring 602 and the inner wall surface of the holder body 40 is a gap necessary for the disc spring 602 to be elastically deformed.

  Further, the upper end surface of the adjustment member 603 is in contact with the lower end surface of the enlarged diameter portion 722 so that the clearance in the axial direction C2 between the adjustment member 603 and the enlarged diameter portion 722 becomes zero. Of the upper end surface of the adjustment member 603, the edge portion 603b of the through hole 603a is formed in an inclined or curved chamfered shape.

  As shown in FIG. 4, the insertion member 72 is formed with the previously described insertion hole 72a and an insertion groove 72b that extends in the radial direction from the outer peripheral surface and communicates with the insertion hole 72a. 4, the width of the insertion groove 72b is set to be smaller than the diameter of the insertion hole 72a, thereby preventing the lead wire 46b from coming out of the insertion hole 72a. The lead wire 46b is inserted into the insertion groove 72b from the outer peripheral surface side of the insertion member 72, and is pushed in until it reaches the insertion hole 72a while elastically deforming the insertion member 72 so as to expand the width of the insertion groove 72b. The insertion hole 72a and the insertion groove 72b have a shape extending over the entire axial direction C2 of the insertion member 72, and a plurality of the insertion holes 72a and the insertion grooves 72b are formed at positions symmetrical with respect to the radial center point in the cross-sectional view shown in FIG. Has been.

  Further, since the diameter d1 of the disc spring facing surface 72c is larger than the inner diameter D4 of the adjusting member 603 as described above, the adjusting member 603 is inserted into the insertion member 72 unless it is from the opposite side (lower side in FIG. 2) of the connector housing 46. It cannot be inserted and assembled in place. On the other hand, the disc spring 602 can be inserted into the insertion member 72 from any side and assembled at a predetermined position. In view of these points, in the present embodiment, first, the adjustment member 603 is inserted into the insertion member 72 from below. Thereafter, the pin 723 is inserted into the housing body 68 and the insertion member 72 is assembled to the housing body 68. Thereafter, the disc spring 602 is inserted into the insertion member 72 from above.

  Next, the operation of the fuel injection valve 10 will be described.

  When the electromagnetic coil 62 is energized, the armature 64 is attracted to the magnetized stator 63 and the armature 64 moves toward the stator 63 against the urging force of the spring 66. As a result, the ball valve 65 opens and the outlet orifice 53a communicates with the valve chamber 43a. Therefore, the high pressure fuel in the back pressure chamber 27 is opened to the low pressure side (valve chamber 43a) through the outlet orifice 53a. Since both the orifices 53a and 52a are set so that the outflow amount from the outlet orifice 53a with respect to the back pressure chamber 27 is larger than the inflow amount from the inlet orifice 52a, the back pressure chamber is opened when the ball valve 65 is opened as described above. 27 fuel pressure decreases. As a result, the needle 30 lifts up (valve opening operation), and the high-pressure fuel supplied from the common rail to the fuel injection valve 10 is injected from the injection hole 22 through the high-pressure passages 42, 51, and 23.

  The low pressure fuel released to the valve chamber 43 a as the ball valve 65 is opened flows into the low pressure passage 44 through the grooves 54 and 55 of the orifice plate 50. Then, it flows out of the fuel injection valve 10 from the low pressure passage 44 and is returned to a fuel tank (not shown).

  Thereafter, when energization of the electromagnetic coil 62 is stopped, the armature 64 is pushed back to the spring 66, and the ball valve 65 closes the outlet orifice 53a, so that the fuel pressure in the back pressure chamber 27 rises again. As a result, the needle 30 is seated on the seat surface of the nozzle body 20 and the passage between the high-pressure passage 23 and the injection hole 22 is blocked, thereby terminating the injection.

  Next, the effect exhibited by the configuration of the present embodiment will be described.

  In the present embodiment, the diameter d1 of the disc spring facing surface 72c is set larger than the diameter d2 of the adjusting member facing surface 72d. The effect by this structure is demonstrated, comparing the fuel injection valve 10x shown in FIGS. 6-8 as a comparative example. The insertion member 72x provided in the fuel injection valve 10x as a comparative example is different from the insertion member 72 according to the present embodiment in that the diameter expansion portion 722 is not provided.

  FIG. 6 shows a state in which the disc spring 602 is positioned concentrically with the insertion member 72x, and there is no bias in the clearance between the outer peripheral surface of the insertion member 72x and the inner peripheral surface of the disc spring 602. In this state, the inner peripheral edge 602a of the disc spring 602 does not enter the through hole 603a of the adjustment member 603, and the disc spring 602 does not tilt and the amount of elastic deformation does not decrease.

  FIG. 7 shows a state in which the plurality of disc springs 602 are all eccentric to the same side (right side in FIG. 7) with respect to the insertion member 72x, and the clearance is biased. In this state, the inner peripheral edge 602a enters the through hole 603a, the disc spring 602 is inclined, the amount of elastic deformation is reduced, and the pressing force is reduced. As a result, the vibration of the electric unit U due to the vibration of the engine becomes larger than expected, and the lead wire 46b is easily disconnected. For example, the electrical connection portion between the lead wire 46b and the internal terminal 67 and the electrical connection portion between the lead wire 46b and the connector terminal 46a are damaged and easily disconnected.

  FIG. 8 shows a state in which some of the plurality of disc springs 602 are eccentrically located on one side with respect to the insertion member 72x, and the other disc springs 602 are eccentric on the other side. That is, the direction of eccentricity differs for each disc spring 602. Specifically, the upper and lower two disc springs 602 are eccentric on the left side of FIG. 8, and the central disc spring 602 is eccentric on the right side of FIG. Since the lower disc spring 602 is decentered, the inner peripheral edge 602a enters the through hole 603a in the same manner as in FIG. 7, and the disc spring 602 is inclined to reduce the amount of elastic deformation. Moreover, in the case of FIG. 8, since the middle disc spring 602 is eccentric in a direction different from the upper and lower two disc springs 602, the amount of elastic deformation is further reduced as compared with the case of FIG. Becomes larger.

  FIG. 9 is a graph showing the results of a vibration test performed by the present inventor. In this vibration test, the fuel injection valve is actually vibrated in the axial direction C1 until the lead wire 46b is disconnected. Then, the number of vibration cycles at the time of disconnection, that is, the number of times the fuel injection valve is moved up and down is measured. The vibration test is carried out a plurality of times with different displacement amplitudes, and the results obtained by the measurement are plotted in FIG. The displacement amplitude used in the test is set on the assumption of the displacement amplitude when the elastic force (pressing force) is lowered due to the state shown in FIGS.

  From the test results shown in FIG. 9, it was found that the larger the displacement amplitude, the more the disconnection occurs with a smaller number of vibration cycles. That is, suppressing the decrease in the amount of elastic deformation by suppressing the inclination of the disc spring 602 means that it is effective in preventing disconnection.

  In view of this test result, in this embodiment, the diameter d1 of the disc spring facing surface 72c is set larger than the diameter d2 of the adjusting member facing surface 72d. Therefore, even when the adjustment member 603 is displaced in the radial direction by the amount corresponding to the insertion clearance, the inner peripheral edge 602a moves in the radial direction toward the larger clearance. Is suppressed by coming into contact with the disc spring facing surface 72c. Therefore, since it can suppress that the inner peripheral side edge 602a enters the through-hole 603a, it can suppress that the disc spring 602 inclines, and can suppress that the elastic force (pressing force) of the disc spring 602 becomes smaller than expected. Therefore, it can suppress that the vibration of the electric unit U becomes larger than expected, and the fear of the disconnection of the lead wire 46b can be reduced.

  Further, by providing the insertion member 72 with the enlarged diameter portion 722, the movement of the disc spring 602 toward the radial center is suppressed. Therefore, even when the disc spring 602 having a large inner diameter D3 is employed, that is, when the clearance between the inner peripheral surface of the disc spring 602 and the outer peripheral surface of the insertion member 72 is large, the inner peripheral edge 602a penetrates. It can suppress entering into the hole 603a. Therefore, in selecting the disc spring 602, the dimensional constraint on the inner diameter D3 can be relaxed, and the selection range can be expanded.

  Furthermore, in this embodiment, since the diameter d1 of the disc spring facing surface 72c is set larger than the diameter D4 of the through hole 603a, the inner peripheral edge 602a enters the through hole 603a and the disc spring 602 is inclined. It can be further suppressed. In particular, if the insertion member 72 and the adjustment member 603 are located concentrically, the entire clearance between the insertion member 72 and the adjustment member 603 is blocked by the enlarged diameter portion 722, so that the inner peripheral edge 602a can be prevented from entering the through hole 603a.

  Furthermore, in this embodiment, the adjustment member 603 is in contact with the enlarged diameter portion 722 so that the clearance in the axial direction C2 between the adjustment member 603 and the enlarged diameter portion 722 becomes zero. Therefore, it is possible to further suppress the inner peripheral edge 602a from entering the through hole 603a and tilting the disc spring 602.

  Further, in the present embodiment, a plurality of disc springs 602 are stacked in the axial direction C2. In this case, as illustrated in FIG. 8, in addition to a decrease in the amount of elastic deformation due to the inclination of the disc spring 602, a decrease in the amount of elastic deformation due to a different direction of eccentricity also occurs, so the pressing force to the electric unit U is insufficient. Are even more concerned. Therefore, in this case, according to the present embodiment, in which the diameter d1 of the disc spring facing surface 72c is set larger than the diameter d2 of the adjusting member facing surface 72d, the through hole 603a of the inner peripheral edge 602a is applied. The effect of suppressing entry into the water is more remarkably exhibited.

  Further, according to the setting of the diameters d1 and d2 according to the present embodiment, the clearance between the disc spring 602 and the insertion member 72 becomes smaller than when both the diameters d1 and d2 are made the same against the present embodiment. The amount by which the plurality of disc springs 602 are displaced in the radial direction can be reduced. Therefore, it is possible to suppress a decrease in the amount of elastic deformation caused by the eccentricity of the plurality of disc springs 602 in different directions as shown in FIG. Therefore, in the case where a plurality of disc springs 602 are stacked, according to the present embodiment to which the diameter d1 of the disc spring facing surface 72c is set larger than the diameter d2 of the adjusting member facing surface 72d, the elastic force ( The effect of suppressing the decrease in pressing force is more remarkably exhibited.

  Furthermore, in this embodiment, the axial center position of the electric unit U with respect to the axial center position of the holder body 40 is different. That is, the axial center of the disc spring 602 is decentered with respect to the axial center of the holder body 40. In the case of this configuration, since the compressive stress applied to the holder body 40 is transmitted eccentrically to the disc spring 602, the inventor has found that a phenomenon occurs in which the disc spring 602 rotates around the axis center due to vibration of the engine. Is getting. The compressive stress is generated in the holder body 40 when the fuel injection valve 10 inserted and arranged at a predetermined part of the engine is pressed in the insertion direction by a clamp (not shown).

  And if the disc spring 602 rotates like the said knowledge, concern that the inner peripheral edge 602a of the disc spring 602 will enter into the through-hole 603a of the adjustment member 603 will become large. Therefore, in this case, according to the present embodiment, in which the diameter d1 of the disc spring facing surface 72c is set larger than the diameter d2 of the adjusting member facing surface 72d, the through hole 603a of the inner peripheral edge 602a is applied. The effect of suppressing entry into the water is more remarkably exhibited.

(Second Embodiment)
In this embodiment, the insertion member 72 having the structure shown in FIGS. 3 and 4 is changed to an insertion member 720 having the structure shown in FIG.

  Specifically, the insertion member 720 according to the present embodiment is formed in a portion opposite to the disc spring facing surface 72c with respect to the adjusting member facing surface 72d, and protrudes radially outward from the adjusting member facing surface 72d. It has a protruding portion 721a having a shape. The protrusion 721a is formed in a shape that protrudes radially outward from the outer peripheral surface of the base 721 and extends in the axial direction (vertical direction in FIG. 10). The protruding height of the protruding portion 721a is set to be the same as the protruding height of the enlarged diameter portion 722.

  In the axial direction, the protruding portion 721a is located on the opposite side of the enlarged diameter portion 722 with respect to the base portion 721. Therefore, the adjustment member 603 inserted and arranged on the adjustment member facing surface 72d is positioned between the enlarged diameter portion 722 and the protruding portion 721a in the axial direction, and is moved in the axial direction by the enlarged diameter portion 722 and the protruding portion 721a. Be regulated.

  Furthermore, the insertion member 720 according to the present embodiment is formed in a shape that can be elastically deformed so as to displace the radial position of the protruding portion 721a toward the radial center. Specifically, a portion of the insertion member 720 including the protruding portion 721a and the enlarged diameter portion 722 is formed in a cylindrical shape having an internal space and has a notch 721b extending in the axial direction. In the example shown in FIG. 10, a plurality of (for example, two) notches 721b are formed. Thus, since the insertion member 720 has a cylindrical shape and a structure having the notch 721b, the cylindrical portion of the insertion member 720 can be elastically deformed so as to shrink in the radial direction. Therefore, the adjustment member 603 can be inserted so as to get over the protruding portion 721a while reducing the diameter of the cylindrical portion, and the adjustment member 603 can be inserted and disposed on the adjustment member facing surface 72d.

  As described above, the insertion member 720 according to the present embodiment is formed in a portion opposite to the disc spring facing surface 72c with respect to the adjusting member facing surface 72d, and has a shape protruding outward in the radial direction from the adjusting member facing surface 72d. It has a protrusion 721a. Therefore, the adjustment member 603 inserted and arranged on the adjustment member facing surface 72d is restricted from moving in the axial direction by the enlarged diameter portion 722 and the protruding portion 721a. Therefore, when the adjustment member 603 is assembled to the insertion member 720 and then the insertion member 720 is assembled to the housing main body 68, the adjustment member 603 can be prevented from falling off the insertion member 720, so that the assembly workability can be improved.

  Furthermore, according to the present embodiment, the insertion member 720 is formed in a shape that can be elastically deformed so as to displace the radial position of the protruding portion 721a toward the radial center. Specifically, a notch 721 b extending in the axial direction is formed in the insertion member 720. Therefore, it is possible to insert the adjusting member 603 so as to get over the protruding portion 721a while elastically deforming the protruding portion 721a so as to be displaced toward the center in the radial direction.

(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 as illustrated below. Not only combinations of parts that clearly show that combinations are possible in each embodiment, but also combinations of the embodiments even if they are not explicitly stated unless there is a problem with the combination. Is also possible.

  In the first embodiment, as shown in FIG. 3, the inner peripheral edge 602 a is arranged in a direction that is positioned closer to the adjustment member 603 than the outer peripheral edge 602 b in any of the plurality of disc springs 602. . In other words, all the disc springs 602 are arranged in a direction that protrudes toward the adjustment member 603 side (lower side). On the other hand, as long as the disc spring 602 that contacts the adjustment member 603 is arranged in a direction that protrudes downward, the other disc spring 602 may be arranged in a direction that protrudes upward. Moreover, although the fuel injection valve 10 shown in FIG. 3 is provided with the some disc spring 602, the structure provided with the one disc spring 602 may be sufficient.

  The fuel injection valve 10 according to the first embodiment has a shaft center (see reference C2 in FIG. 1) of the electric unit U, that is, a disc spring 602, with respect to the shaft center of the holder body 40 (see reference C1 in FIG. 1). The center of the shaft is in an eccentric position. On the other hand, the fuel injection valve 10 in which the axial center of the electric unit U coincides with the axial center of the holder body 40 may be used.

  In the electric unit U according to the first embodiment, the ball valve 65 is opened / closed by the electromagnetic force of the electric actuator 60, but the ball valve 65 may be opened / closed by the displacement force of the piezo element.

  The lead wire 46b according to the first embodiment is held by the insertion member 72 and is protected by the insertion member 72 so as not to be damaged by contact with the holder body 40. In contrast, the lead wire 46b may be held and protected by a member different from the insertion member 72. In other words, the insertion member 72 is not limited to the one having the lead wire 46b inside, and may have a shape in which the insertion hole 72a and the insertion groove 72b are eliminated.

  In the fuel injection valve 10 according to the first embodiment, as shown in FIG. 1, the elastic force of the disc spring 602 applied to the electric unit U is changed from the counter-injection hole side (upper side in FIG. 1) to the injection hole side (see FIG. 1). 1). On the other hand, the structure which provides the said elastic force from a nozzle hole side to a counter nozzle hole side may be sufficient.

  In the first embodiment, as shown in FIG. 3, the upper end surface of the adjustment member 603 is set to the lower end surface of the enlarged diameter portion 722 so that the clearance in the axial direction C2 between the adjustment member 603 and the enlarged diameter portion 722 becomes zero. In contact. On the other hand, the adjustment member 603 and the enlarged diameter part 722 may be arranged so that the clearance is provided without the adjustment member 603 and the enlarged diameter part 722 contacting each other.

  22 injection hole, 40 body, 53a fuel passage, 60 electric actuator, 601 stopper, 602 disc spring, 602a inner peripheral edge, 602b outer peripheral edge, 603 adjustment member, 603a through hole, 65 control valve, 72 insertion member, 721 Base, 721a projecting portion, 722 enlarged diameter portion, 72c conical spring facing surface, 72d adjusting member facing surface, U electric unit.

Claims (5)

A control valve (65) for controlling fuel injection and injection stop from the nozzle hole (22) by opening and closing the fuel passage (53a);
An electric unit (U) including an electric actuator (60) for opening and closing the control valve;
A body (40) for accommodating the electric unit therein;
A stopper (601) for restricting movement of the electric unit to one side in the axial direction of the body;
A shape extending annularly around the axial direction, and a shape in which the annular inner peripheral edge (602a) and the outer peripheral edge (602b) are at different positions in the axial direction, and the electric unit is pressed against the stopper A disc spring (602) that exerts an elastic force;
An adjusting member (603) which has a through hole (603a) penetrating in the axial direction, is arranged adjacent to the disc spring in the axial direction, and adjusts the elastic deformation amount of the disc spring to a desired value. When,
An insertion member (72) arranged to be inserted into the inner peripheral edge and the through hole;
With
The diameter of the conical spring facing surface (72c), which is the portion of the outer peripheral surface of the insertion member that faces the inner peripheral edge, is adjusted in the portion of the outer peripheral surface of the insertion member that faces the wall surface of the through hole. A fuel injection valve larger than the diameter of the member facing surface (72d). The insertion member has a base portion (721) that forms the adjustment member facing surface, and a diameter expanding portion (722) that expands from the base portion and forms the conical spring facing surface,
2. The fuel injection valve according to claim 1, wherein the adjustment member is in contact with the enlarged diameter portion so that a clearance in the axial direction between the adjustment member and the enlarged diameter portion becomes zero.   The fuel injection valve according to claim 1 or 2, wherein the plurality of disc springs are stacked in the axial direction.   The fuel injection valve according to any one of claims 1 to 3, wherein an axial center of the disc spring is in an eccentric position with respect to an axial center of the body. The insertion member is
It has a protruding portion (721a) that is formed on the opposite side of the disc spring facing surface with respect to the adjusting member facing surface, and has a shape protruding outward in the radial direction from the adjusting member facing surface.
The fuel injection valve according to any one of claims 1 to 4, wherein the fuel injection valve has a shape that can be elastically deformed so as to displace the radial position of the protruding portion toward the radial center.

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