JP2008196324A - Valve member and fuel ejection nozzle using it - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To provide a valve member having high wear resistance while inhibiting a rise of manufacturing cost and to provide a fuel injection nozzle using it. <P>SOLUTION: The valve member 20 is used in the injection nozzle 10 which has a nozzle hole 13, a nozzle body 11 formed with a vertical hole 12 communicating with the nozzle hole 13, and a cylinder 30 received in the vertical hole 12 and radially movable while comparting a pressure control chamber 19 for controlling open and close operation of the valve member 20 by insertion of an end of the valve member 20 opening and closing the nozzle hole 13. The valve member 20 has a valve element part 21 formed at an end on a nozzle hole 13 side for seating on and removing from the vertical hole 12, a cylinder slide part 22 formed at an end on the opposite side and slidably supported on an inner wall of the cylinder 30, and a body slide part 23 formed between the valve element part 21 and the cylinder slide part 22 and slidably supported in the vertical hole 12, and a wear resistant coating is formed only on portions of the valve member 21 disposed closer to the nozzle hole 13 side than the cylinder slide part 22. <P>COPYRIGHT: (C)2008,JPO&INPIT

Description

  The present invention relates to a fuel injection valve and a fuel injection nozzle using the same.

  2. Description of the Related Art Conventionally, there has been known a valve member that is housed in a fuel injection device and that controls fuel injection from an injection hole by opening and closing an injection hole formed at the tip by moving in the body in the axial direction. (For example, refer to Patent Document 1).

The valve member in Patent Document 1 has a sliding portion and a guide portion that are partially supported so as to be slidable in the axial direction on an inner peripheral wall of a nozzle body that is a main body of the fuel injection device. The valve member is formed with a valve body portion that comes into contact with a valve seat provided upstream of the nozzle hole formed in the nozzle body. The valve member is provided with a wear-resistant coating on all of the sliding portion, the guide portion, and the valve body portion. Thereby, every time the valve member reciprocates in the axial direction to open and close the nozzle hole, it is possible to suppress wear of a portion that slides on the nozzle body or a portion that collides with the nozzle body.
JP 2000-161174 A

  Usually, a coating apparatus grips an object to be coated and performs a coating process. However, when coating is performed on all the sliding or colliding parts as in the above-described prior art, a part that cannot be coated is generated in the first coating process, and therefore the coating process must be performed at least twice. . For this reason, the problem that the manufacturing cost of a valve member will raise generate | occur | produces.

  The present invention has been made to solve the above problems, and an object of the present invention is to provide a valve member having excellent wear resistance while suppressing an increase in manufacturing cost, and a fuel injection nozzle using the valve member.

In order to achieve the above object, according to the invention described in claim 1, a nozzle body in which a nozzle hole is formed at the tip and a vertical hole communicating with the nozzle hole is formed inside, and the nozzle hole is accommodated in the vertical hole. A rod-like valve member used for an injection nozzle having a cylinder movable in a radial direction while defining a pressure control chamber for controlling an opening / closing operation of the valve member by inserting an end portion of the valve member for opening and closing the valve member,
The valve member is formed at the end of the injection hole, and is formed at the end opposite to the end where the valve body is formed and the valve body that is seated in and out of the vertical hole, and slides on the inner wall of the cylinder A cylinder sliding part that is slidably supported, and a body sliding part that is formed between the valve body part and the cylinder sliding part and is slidably supported in the vertical hole. A wear-resistant coating is applied only to a portion disposed on the nozzle hole side of the sliding portion.

  The cylinder sliding portion is slidably supported by a cylinder accommodated in the vertical hole of the nozzle body. Since this cylinder is movable in the radial direction in the vertical hole, even if the valve member is displaced in the radial direction, it can follow the valve member.

  Since the body sliding portion of the valve member is directly supported by the vertical hole of the nozzle body, it cannot follow the radial movement of the valve member like a cylinder. Therefore, the wear of the body sliding portion is more remarkable than that of the cylinder sliding portion. The valve body part that is seated in and out of the vertical hole of the nozzle body is also significantly worn compared to the cylinder sliding part.

  According to the first aspect of the present invention, since the wear sliding coating is applied to the body sliding portion and the valve body portion that are at least more markedly worn than the cylinder sliding portion, the wear resistance of the valve member is reduced. Can be improved. Further, by not applying the anti-wear coating to the cylinder sliding portion, when the valve member is subjected to the coating treatment, the portion that becomes the cylinder sliding portion can be gripped and coated. This coating process can be completed by a single process, and an increase in the manufacturing cost of the valve member can be suppressed.

  Darely, a wear resistant coating can be provided while suppressing an increase in manufacturing cost by applying a wear resistant coating only to a portion disposed on the nozzle hole side of the cylinder sliding portion.

  According to the invention described in claim 2, the wear resistant coating is a TiN, TiC, TiCN, CrN, DLC or WC / C coating.

  According to this configuration, by adopting a TiN, TiC, TiCN, CrN, DLC or WC / C coating as a wear resistant coating, the friction coefficient of the valve member can be reduced and the wear resistance is improved.

  According to a third aspect of the present invention, the valve member according to the first or second aspect, a vertical hole that accommodates the valve member, an injection hole that communicates with the vertical hole, an upstream side of the injection hole, and a valve member A valve seat on which the valve body portion of the valve member is attached and detached, and a nozzle body formed upstream of the valve seat and having a guide portion that slidably supports the body sliding portion of the valve member, and an upstream side of the support portion The valve is disposed in the vertical hole and slidably supports the cylinder sliding portion of the valve member, thereby allowing an adjustable fuel pressure to act on the fuel reservoir chamber communicating with the nozzle hole and the end of the cylinder sliding portion. And a cylinder that defines a pressure control chamber that controls the opening and closing operation of the member.

  According to this configuration, since the fuel injection nozzle uses the valve member described in claim 1 or 2 as a valve member, it is possible to provide a fuel injection nozzle excellent in wear resistance while suppressing an increase in manufacturing cost.

  An embodiment of a fuel injection nozzle to which the present invention is applied will be described with reference to FIGS. 1 and 2. FIG. 1 shows the overall configuration of a fuel injection valve provided with a fuel injection nozzle. The fuel injection valve 1 is used, for example, in an accumulator fuel injection device for a diesel engine, and injects high-pressure fuel supplied from an accumulator (common rail) (not shown) into an engine combustion chamber.

  As shown in FIG. 1, the fuel injection valve 1 includes an injection nozzle 10, an orifice plate 40, a valve body 50, a control valve 53, a lower body 60, a piezo actuator 62, a driving force transmission unit 63, and the like. The fuel injection valve 1 is laminated in the order of the injection nozzle 10, the orifice plate 40, the valve body 50, and the lower body 60 from below in the drawing, and is fixed to each other by a retaining nut 70.

  The injection nozzle 10 includes a nozzle body 11, a needle 20, a cylinder 30 and a coil spring 16. The nozzle body 11 is formed with nozzle holes 12 (corresponding to the vertical holes recited in the claims) from the upper end to the vicinity of the lower end. By disposing the orifice plate 40 at the upper end of the nozzle body 11, the nozzle hole 12 becomes a closed space. A nozzle hole 13 through which the nozzle hole 12 and the outer wall of the nozzle body 11 pass is formed at the tip of the nozzle body 11. In the nozzle hole 12, a valve seat 14 is formed on the upstream side of the opening of the injection hole 13. A guide portion 15 that supports the needle 20 so as to be slidable in the axial direction is formed on the side wall of the nozzle hole 12. In the nozzle hole 12, the needle 20, the coil spring 16, and the cylinder 30 are accommodated.

  The needle 20 corresponds to the valve member recited in the claims, and is formed in a rod shape. As shown in FIG. 2, a valve body portion 21 is formed at the tip of the valve body portion 21.

  A cylinder sliding portion 22 is formed at the opposite end of the valve body portion 21. The cylinder sliding portion 22 is a sliding portion that is slidably supported in the axial direction on an inner peripheral wall 31 of a cylinder 30 formed in a substantially cylindrical shape housed in the nozzle hole 12.

  Further, a body sliding portion 23 is formed between the valve body portion 21 and the cylinder sliding portion 22. The body sliding portion 23 is a sliding portion that is supported by the guide portion 15 of the nozzle hole 12 so as to be slidable in the axial direction. A cutout portion 24 for forming a gap with the nozzle hole 12 is formed at a portion where the body sliding portion 23 is formed. Since the notch part 24 is formed, fuel can be circulated from the cylinder sliding part 22 side to the valve body part 21 side.

  Since the outer diameter between the body sliding portion 23 and the valve body portion 21 is set to such a dimension that a gap is formed between the nozzle hole 12 and the guide portion 15, the outer diameter passes through the notch portion 24. The fuel thus obtained can be guided to the nozzle hole 13.

  The outer diameter between the cylinder sliding portion 22 and the body sliding portion 23 is smaller than the outer diameter of both the sliding portions 22 and 23. For this reason, the step part 25 is formed in the upper part of the body sliding part 23. A support ring 17 that supports the lower end of the coil spring 16 that urges the needle 20 downward (the direction in which the valve body 21 is seated on the valve seat 14, the valve closing direction) is engaged with the stepped portion 25. .

  A portion of the needle 20 disposed closer to the nozzle hole 13 than the cylinder sliding portion 22 is provided with a TiN, TiC, TiCN, CrN, DLC or WC / C coating as a wear-resistant coating. The cylinder sliding part 22 is intentionally prevented from being coated. The effect of providing the needle 20 with a place where the anti-wear coating is applied and a place where it is not applied will be described later.

  The coil spring 16 is disposed between the support ring 17 and the cylinder 30 while being compressed to some extent in the axial direction. Accordingly, the cylinder 30 is pressed against the lower end surface 44 of the orifice plate 40, and the needle 20 is pressed downward.

  As shown in FIG. 1, by storing the coil spring 16, the needle 20, and the cylinder 30 in the nozzle hole 12, the fuel reservoir chamber 18 is formed between the side wall of the nozzle hole 12 and the outer peripheral wall of the needle 20 and the cylinder 30. The pressure control chamber 19 is formed by the upper end portion of the cylinder sliding portion 22 of the needle 20, the inner peripheral wall 31 of the cylinder 30, and the lower end surface 44 of the orifice plate 40.

  The fuel reservoir chamber 18 is a space for accumulating high-pressure fuel injected from the injection hole 13 and communicates with the injection hole 13. When the needle 20 is seated on the valve seat 14, the communication between the fuel reservoir 18 and the injection hole 13 is cut off, and fuel injection from the injection hole 13 is stopped. When the needle 20 is separated from the valve seat 14, the fuel reservoir chamber 18 and the injection hole 13 communicate with each other, and fuel is injected from the injection hole 13.

  The pressure control chamber 19 is a space for accumulating high-pressure fuel that controls the axial movement of the needle 20. The fuel supplied to the pressure control chamber 19 acts on the upper end portion of the cylinder sliding portion 22 to press the needle 20 downward. A method for controlling the movement of the needle 20 in the axial direction will be described later.

  The orifice plate 40 is formed in a substantially disk shape and is disposed between the nozzle body 11 and the valve body 50. In the orifice plate 40, a fuel passage 41, a first communication passage 42, and a second communication passage 43 are formed so as to penetrate both end faces of the plate 40.

  The fuel passage 41 is a passage for supplying high-pressure fuel in the pressure accumulator to the fuel reservoir chamber 18 and is formed so as to penetrate the valve body 50 and the lower body 60 in the axial direction. The opening of the fuel passage 41 formed in the lower body 60 is connected to the pressure accumulator.

  The first communication passage 42 is a passage that connects the fuel reservoir chamber 18 and a valve chamber 51 formed in a valve body 50 described later. A substantially annular groove is formed in the lower end surface 44 of the orifice plate 40, and the fuel passage 41 and the first communication passage 42 are connected to the bottom of the groove. The second communication passage 43 is a passage connecting the pressure control chamber 19 and the valve chamber 51.

  The valve body 50 is formed in a substantially disk shape and is disposed between the orifice plate 40 and the lower body 60. The valve body 50 is formed with a valve chamber 51 that opens to a lower end surface in contact with the orifice plate 40. The first and second communication passages 42 and 43 described above are opened at the lower end surface of the valve chamber 51. A third communication passage 52 connected to a vertical hole 61 formed in the lower body 60 described later is opened at the upper end surface of the valve chamber 51.

  The valve chamber 51 accommodates a control valve 53 and a coil spring 56 that control the flow of fuel in the first, second, and third communication passages 42, 43, and 52. The control valve 53 has a low-pressure side sheet 54 formed on the upper side and a high-pressure side sheet 55 formed on the lower side.

  When the low-pressure side seat 54 is seated on the upper end surface of the valve chamber 51, the opening of the third communication passage 52 is closed, and the fuel reservoir chamber 18, the first communication passage 42, the valve chamber 51, the second communication passage 43, the pressure control. A first path connecting the chambers 19 is formed, and the high-pressure fuel in the fuel reservoir chamber 18 is supplied to the pressure control chamber 19.

  When the high-pressure side seat 55 is seated on the lower end surface of the valve chamber 51 (the upper end surface of the orifice plate 40), the opening of the first communication passage 42 is blocked and the opening of the third communication passage 52 is opened. As a result, a second path connecting the pressure control chamber 19, the second communication passage 43, the valve chamber 51, the third communication passage 52, and the vertical hole 61 of the lower body 60 is formed, and the high pressure fuel in the pressure control chamber 19 is low. It is discharged into a certain vertical hole 61. As a result, the pressure in the pressure control chamber 19 decreases. By operating the control valve 53 in this way, the pressure in the pressure control chamber 19 can be adjusted.

  The lower body 60 accommodates the piezo actuator 62 and the driving force transmission portion 63 in a longitudinal hole 61 formed in the axial direction, and supports the valve body 50 on the lower end surface. The piezoelectric actuator 62 is formed by alternately stacking piezoelectric ceramic layers such as PZT and electrode layers, and expands and contracts in the stacking direction (vertical direction) by charging and discharging with a drive circuit (not shown). The vertical hole 61 is connected to a low pressure side such as a fuel tank via a passage (not shown).

  The driving force transmission unit 63 is disposed below the piezo actuator 62 and transmits the displacement of the piezo actuator 62 to the control valve 53 via the pin 64 accommodated in the third communication path 52.

  When the piezo actuator 62 is charged, the piezo actuator 62 extends. The control valve 53 is pushed downward by the pin 64, the low pressure side seat 54 is separated from the upper end surface of the valve chamber 51, and the high pressure side seat 55 is seated on the lower end surface of the valve chamber 51, and the first communication path 42. The opening of is closed. Thereby, the high-pressure fuel in the pressure control chamber 19 is discharged to the low-pressure side through the second path.

  When the piezo actuator 62 is discharged, the piezo actuator 62 contracts. When the piezo actuator 62 contracts, the control valve 53 and the pin 64 move upward by the biasing force of the coil spring 56. When the control valve 53 moves upward, the high-pressure side seat 55 is separated from the lower end surface of the valve chamber 51, and the low-pressure side seat 54 is seated on the upper end surface of the valve chamber 51, and the third communication passage 52 is opened. Is blocked. As a result, the high-pressure fuel in the fuel reservoir 18 is supplied to the pressure control chamber 19 through the first path.

  Next, the operation of the fuel injection valve 1 having the above configuration will be described. When high pressure fuel is supplied from the pressure accumulator to the fuel injection valve 1 when the piezo actuator 62 is discharged and the control valve 53 closes the opening of the third communication passage 52, the high pressure fuel passes through the fuel passage 41. Then, the fuel is supplied to the fuel reservoir chamber 18 and is also supplied to the pressure control chamber 19 through the first path.

  The needle 20 has a force in which the high-pressure fuel in the pressure control chamber 19 acts on the upper end surface of the needle 20 to press the needle 20 downward (in the valve closing direction), a force to press the needle 20 downward by the biasing force of the coil spring 16, In addition, the high-pressure fuel in the fuel reservoir chamber 18 acts in the vicinity of the valve body 21 to push up the needle 20 upward (in the valve opening direction).

  At this time, the force that pushes the needle 20 downward exceeds the force that pushes the needle 20 upward, so that the valve body portion 21 is seated on the valve seat portion 14 and fuel is not injected from the nozzle hole 13.

  When the piezo actuator 62 is charged, the control valve 53 is pushed downward by the pin 64, the high pressure side seat 55 closes the opening of the first communication passage 42, and the low pressure side seat 54 opens the third communication passage 52. Is released. Then, the high-pressure fuel in the pressure control chamber 19 is discharged to the low-pressure side through the second path, and the pressure in the pressure control chamber 19 starts to decrease.

  When the pressure in the pressure control chamber 19 decreases to the valve opening pressure, the force that pushes the needle 20 upward exceeds the force that pushes the needle 20 downward, the needle 20 lifts upward, and the valve body 21 separates from the valve seat 14. The fuel is injected from the nozzle hole 13.

  When the piezo actuator 62 is discharged again, the control valve 53 closes the opening of the third communication path 52 and opens the opening of the first communication path 42. Then, the high-pressure fuel in the fuel reservoir chamber 18 is supplied again to the pressure control chamber 19 through the first path, and the pressure in the pressure control chamber 19 increases.

  When the pressure in the pressure control chamber 19 rises to the valve closing pressure, the force that presses the needle 20 downward exceeds the force that pushes the needle 20 upward, the needle 20 moves downward, and the valve body 21 is seated on the valve seat 14. The fuel injection from the nozzle hole 13 ends.

  Next, the characteristic part in this embodiment is demonstrated in detail with reference to FIG. As described above, the needle 20 is provided with a TiN, TiC, TiCN, CrN, DLC or WC / C coating as a wear-resistant coating at a portion disposed on the nozzle hole 13 side of the cylinder sliding portion 22. . The cylinder sliding portion 22 is not coated with the above coating.

  In general, when a wear-resistant coating is applied to the surface of an object to be coated, for example, the coating apparatus applies the coating while a jig holds a part of the object to be coated. Therefore, the part gripped by the jig of the object to be coated cannot be coated.

  If the coating for wear resistance is applied to all of the sliding portion, guide portion, and valve body portion of the needle as in the prior art, at least two coating treatments are required for the reasons described above. , Increase manufacturing costs. In addition, when the coating process is performed twice or more, there is a risk of unevenness in the coating.

  A cylinder sliding portion 22 is formed at the end of the needle 20 of the present embodiment. As described above, the cylinder sliding portion 22 is supported by the inner peripheral wall 31 of the cylinder 30 so as to be slidable in the axial direction. The cylinder 30 is accommodated in the nozzle hole 12 of the nozzle body 11, and is movable to some extent in the radial direction while contacting the lower end surface 44 of the orifice plate 40. For this reason, even if the needle 20 is displaced in the radial direction, the cylinder 30 can follow the movement of the needle 20 in the radial direction.

  The body sliding portion 23 formed between the valve body portion 21 and the cylinder sliding portion 22 of the needle 20 is directly supported by the guide portion 15 as described above. Unlike the cylinder 30 described above, the guide portion 15 cannot follow the movement of the needle 20 in the radial direction.

  For the above reason, when the needle 20 moves in the radial direction, the body sliding portion 23 is more worn than the cylinder sliding portion 22. Needless to say, the valve body 21 formed at the tip of the needle 20 is seated at the lower end of the nozzle hole 12 so that the wear is more significant than the cylinder sliding portion 22.

  The inventor pays attention to the circumstances relating to the above-described coating process and the wear characteristics of the needle 20 having the cylinder sliding portion 22 supported by the cylinder 30 and the body sliding portion 23 supported by the guide portion 15, By using the needle 20 having a configuration in which the portion disposed on the nozzle hole 13 side of the cylinder sliding portion 22 is coated with wear resistance, the needle 20 that satisfies both circumstances can be obtained. It was.

  The cylinder sliding portion 22 is held by a jig of the coating apparatus and coated for wear resistance, so that the above-described configuration, that is, the portion disposed closer to the nozzle hole 13 than the cylinder sliding portion 22 is wear resistant. It is possible to manufacture the needle 20 with the coating for.

  According to the needle 20 manufactured in this way, at least the valve body 21 and the body sliding portion 23 where wear is remarkable are coated with wear resistance, so the wear resistance of the needle 20 is improved. Can be made. In addition, since the cylinder sliding portion 22 that is not subjected to coating is provided, the jig of the coating apparatus can grip this part, and the coating process can be completed in one time, thereby suppressing an increase in manufacturing cost. Can do.

  Further, after coating the needle 20, the sliding clearance between the cylinder sliding portion 22 and the inner peripheral wall 31 of the cylinder 30 and the sliding clearance between the body sliding portion 23 and the guide portion 15 are set to optimum values. For matching work.

  The matching operation between the cylinder sliding portion 22 and the inner peripheral wall 31 of the cylinder 30 is performed by cutting the cylinder sliding portion 22. The matching operation between the body sliding portion 23 and the guide portion 15 is performed by cutting the guide portion 15.

  From the point of this matching operation, there is a reasonable reason not to coat the cylinder sliding portion 22. Since the cylinder 30 is a component that supports the needle 20 so as to be slidable in the axial direction, in particular, the upper end surface of the cylinder 30 (the portion that contacts the lower end surface 44 of the orifice plate 40) and the inner peripheral wall 31 of the cylinder 30. It is necessary to increase the verticality. For this reason, the cylinder 30 is processed with high accuracy in order to increase the perpendicularity before being accommodated in the nozzle hole 12.

  When the matching operation between the cylinder sliding portion 22 and the inner peripheral wall 31 of the cylinder 30 is performed, the cylinder sliding portion 22 is not cut, but the inner peripheral wall 31 of the cylinder 30 that has been processed with high accuracy to increase the degree of perpendicularity. Matching work is done by shaving. Since the coating is not applied to the cylinder sliding portion 22 as in this embodiment, the matching operation between the cylinder sliding portion 22 and the inner peripheral wall 31 of the cylinder 30 is facilitated.

  By employing a TiN, TiC, TiCN, CrN, DLC or WC / C coating as a wear resistant coating, the friction coefficient of the valve member can be reduced and the wear resistance is improved. Preferably, among the coatings described above, it is desirable to employ TiN, CrN, or DLC. In addition to the function of reducing the coefficient of friction, these coatings are excellent in the function of suppressing the exposure of carbides to the coating surface and the low attack on the nozzle body 11.

  More preferably, it is desirable to employ DLC capable of nonmetallizing the surface. The fuel contains a carboxylate, which contains polar molecules. Adhesion of fuel degradation products to the needle 20, that is, deposit deposition, occurs when molecules having this polarity are attracted to the metal surface. Since the surface of DLC can be made non-metallic, the above-described phenomenon is less likely to occur, and adhesion of fuel degradation products to the needle 20 can be prevented.

It is sectional drawing of a fuel injection valve provided with the fuel injection nozzle in 1st Embodiment of this invention. It is a side view of the needle used for the fuel injection nozzle in a 1st embodiment.

Explanation of symbols

DESCRIPTION OF SYMBOLS 1 Fuel injection valve, 10 Injection nozzle, 11 Nozzle body, 12 Nozzle hole (vertical hole), 13 Injection hole, 14 Valve seat, 15 Guide part, 18 Fuel reservoir chamber, 19 Pressure control chamber, 20 Needle (valve member), 21 Valve body, 22 Cylinder sliding portion, 23 Body sliding portion, 30 Cylinder, 31 Inner peripheral wall, 40 Orifice plate, 41 Fuel passage, 42 First communication passage 43 Second communication passage, 44 Lower end surface, 50 Valve body, 52 3rd communication path, 53 Control valve, 60 Lower body, 61 Vertical hole, 62 Piezo actuator, 63 Driving force transmission part, 70 Retaining nut

Claims (3)

A nozzle body in which a nozzle hole is formed at the tip and a vertical hole communicating with the nozzle hole inside, and the valve member housed in the vertical hole and inserted into the end of the valve member that opens and closes the nozzle hole A rod-shaped valve member used for an injection nozzle having a cylinder movable in a radial direction while defining a pressure control chamber for controlling the opening and closing operation of
The valve member is formed at an end portion on the injection hole side, and is formed at an end portion on the side opposite to the end portion where the valve body portion is formed, and a valve body portion that is separated from and seated in the vertical hole, and the cylinder A cylinder sliding portion that is slidably supported on the inner wall, and a body sliding portion that is formed between the valve body portion and the cylinder sliding portion and is slidably supported in the vertical hole. And
A valve member, wherein a wear-resistant coating is applied only to a portion of the valve member that is disposed closer to the nozzle hole than the cylinder sliding portion.   The valve member according to claim 1, wherein the wear-resistant coating is a TiN, TiC, TiCN, CrN, DLC or WC / C coating. The valve member according to claim 1 or 2,
A vertical hole that accommodates the valve member, a nozzle hole that communicates with the vertical hole, a valve seat that is formed on the upstream side of the nozzle hole, on which the valve body portion of the valve member is seated, and upstream of the valve seat A nozzle body having a guide portion formed on the side and slidably supporting the body sliding portion of the valve member;
A fuel reservoir chamber communicating with the nozzle hole and the cylinder sliding portion are disposed in the vertical hole upstream of the support portion and slidably support the cylinder sliding portion of the valve member. And a cylinder for defining a pressure control chamber for controlling an opening / closing operation of the valve member by applying an adjustable fuel pressure to an end of the fuel injection nozzle.

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