JP2015092063A - Nozzle plate mounting structure for fuel injection device - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide a nozzle plate mounting structure for a fuel injection device capable of reducing manufacturing manhours of the fuel injection device and reducing manufacturing costs of the fuel injection device.SOLUTION: When a cylindrical fitting portion of a nozzle plate is press-fitted to the tip side of a valve body, a projection of an arm portion brings the tip side of an arm portion body down into a locking groove of the valve body, the tip side of the arm portion body is pressed to a groove wall of the locking groove of the valve body in a state of being elastically deformed so that the tip side of the arm portion body is crushed (tip side of arm portion body and locking groove of valve body are engaged), and the nozzle plate is fixed to the tip side of the valve body in a state of being locked, thus manufacturing manhours of a fuel injection device can be reduced, and also manufacturing costs of the fuel injection device can be reduced in comparison with a conventional case where a metallic nozzle plate is welded and fixed to a tip of a metallic valve body.

Description

  The present invention relates to a structure for mounting a nozzle plate for a fuel injection device (hereinafter abbreviated as “nozzle plate” as appropriate) used to atomize and inject fuel flowing out from a fuel injection port of a fuel injection device. is there.

  An internal combustion engine such as an automobile (hereinafter abbreviated as “engine”) mixes fuel injected from a fuel injection device and air introduced through an intake pipe to form a combustible air-fuel mixture. Qi is burned in the cylinder. In such an engine, it is known that the mixed state of the fuel and air injected from the fuel injection device has a great influence on the performance of the engine, and in particular, the atomization of the fuel injected from the fuel injection device is reduced. It is known to be an important factor that affects engine performance.

  Therefore, conventionally, as shown in FIG. 10, in the fuel injection device 100, a metal nozzle plate 103 is welded to a metal valve body 102 in which a fuel injection port 101 is formed, and is injected from the fuel injection port 101. The fuel atomization is promoted by injecting the fuel into the intake pipe through the nozzle hole 104 formed in the nozzle plate 103 (see Patent Documents 1 and 2).

JP 11-270438 A JP 2011-144731 A

  However, the conventional fuel injection device 100 performs welding using a masking jig in order to prevent welding spatter from entering the nozzle holes 104 of the nozzle plate 103 and blocking the nozzle holes 104 by welding spatter. It was difficult to perform welding efficiently. As a result, the conventional fuel injection device 100 has a large number of manufacturing steps, and it is difficult to reduce the manufacturing cost.

  Thus, the present invention provides a nozzle plate mounting structure for a fuel injection device that can reduce the number of manufacturing steps of the fuel injection device and reduce the manufacturing cost of the fuel injection device.

  As shown in FIGS. 1 to 8, the present invention is a structure for mounting a nozzle plate 3 for a fuel injection device in which nozzle holes 7 for atomizing and injecting fuel flowing out from a fuel injection port 4 of the fuel injection device 1 are formed. It is about. In this invention, the metal valve body 5 of the fuel injection device 1 in which the fuel injection port 4 is formed has an annular locking groove 8 formed along the outer periphery. Further, the nozzle plate 3 for the fuel injection device is formed so as to close a cylindrical fitting portion 12 into which the distal end side of the valve body 5 is press-fitted, and one end side of the cylindrical fitting portion 12 so as to close the valve body. 5 on the bottom wall portion 14 with which the tip end face 13 is abutted and the nozzle hole is formed, and on the other end side of the tubular fitting portion 12 and in the locking groove 8 of the valve body 5. And an arm portion 10 to be engaged. Moreover, the said cylindrical fitting part 12, the said bottom wall part 14, and the said arm part 10 of the said nozzle plate 3 for fuel injection apparatuses are integrally formed with the synthetic resin material. The arm portion 10 includes an arm portion main body 25 whose front end 25 a is engaged with the locking groove 8, and an arm that is in contact with the outer peripheral surface of the valve body 5 on the rear end 25 b side of the arm portion main body 25. A protrusion 26 formed on the inner surface 25c side of the body part 25 and an arm part body support part 27 that elastically supports the arm part body 25 on the tubular fitting part 12 are provided. When the tubular fitting portion 12 is press-fitted into the valve body 5, the protrusion 26 is located on the distal end 25 a side of the arm portion main body 25 with the arm portion main body support portion 27 as a fulcrum. As a result, the tip 25a side of the arm body 25 is pressed against the groove wall 33 of the locking groove 8 and a difference in thermal expansion occurs between the valve body 5 and the nozzle plate 3 for the fuel injection device. Even in this case, the bottom wall portion 14 and the distal end surface 13 of the valve body 5 are caused by the elastic force acting on the contact portion between the distal end 25a side of the arm portion main body 25 and the groove wall 33 of the locking groove 8. The contact state with is maintained.

  According to the mounting structure of the nozzle plate for a fuel injection device according to the present invention, when the cylindrical fitting portion of the nozzle plate is press-fitted into the distal end side of the valve body, the projection of the arm portion causes the distal end side of the arm portion main body to be in the valve body. The arm body is pushed down into the locking groove and pressed against the groove wall of the locking groove of the valve body in a state of being elastically deformed so that the front end side of the arm main body is crushed (the front end side of the arm main body and the valve body The metal nozzle plate is welded and fixed to the tip of the metal valve body. Compared to the conventional example, the number of manufacturing steps of the fuel injection device can be reduced, and the manufacturing cost of the fuel injection device can be reduced.

  Further, according to the nozzle plate mounting structure for a fuel injection device according to the present invention, when a difference in thermal expansion or a manufacturing error occurs between the nozzle plate and the valve body, the tip end side of the arm portion main body of the nozzle plate is elastically deformed. This absorbs the thermal expansion difference and manufacturing error between the nozzle plate and the valve body, and the tip of the arm body is pressed against the groove wall of the locking groove of the valve body (with the tip of the arm body Because the nozzle plate is fixed to the tip of the valve body in a state where the nozzle plate is prevented from coming off, even if the fuel injection pressure acts on the nozzle plate, the nozzle plate Does not fall off the valve body.

FIG. 2 is a diagram schematically showing a usage state of the fuel injection device 1. It is a figure which shows the attachment structure of the nozzle plate which concerns on 1st Embodiment of this invention. 2A is a front view of the front end side of the fuel injection device, and FIG. 2B is a side view of the front end side of the fuel injection device as viewed from the direction indicated by the arrow C1 in FIG. (C) is a front end side sectional view of the fuel injection device shown by cutting the nozzle plate along the line A1-A1 in FIG. 2 (a), and FIG. 2 (d) is A1-A1 in FIG. 2 (a). It is a front end side sectional view of a fuel injection device shown by cutting the whole along a line. 3A is a cross-sectional view taken along line A2-A2 in FIG. 2C, and FIG. 3B is cut along line A3-A3 in FIG. It is sectional drawing shown. FIG. 4A is a front view of the nozzle plate according to the first embodiment of the present invention, and FIG. 4B is a side view of the nozzle plate viewed from the direction of arrow C2 in FIG. 4 (c) is a cross-sectional view of the nozzle plate shown cut along line A4-A4 in FIG. 4 (a). Fig.5 (a) is a front view of the valve body which concerns on 1st Embodiment of this invention, FIG.5 (b) is a front end side view of a valve body. It is a figure which shows the attachment structure of the nozzle plate which concerns on 2nd Embodiment of this invention. 6A is a front view of the front end side of the fuel injection device, and FIG. 6B is a side view of the front end side of the fuel injection device viewed from the direction indicated by the arrow C3 in FIG. (C) is front end side sectional drawing of the fuel-injection apparatus which cut | disconnects and shows a nozzle plate along the A5-A5 line of Fig.6 (a). 7A is a cross-sectional view taken along line A6-A6 of FIG. 6C, and FIG. 7B is taken along line A7-A7 of FIG. 7A and FIG. 6C. It is sectional drawing cut | disconnected and shown along. FIG. 8A is a front view of the valve body according to the second embodiment of the present invention, and FIG. 8B is a side view of the distal end side of the valve body. It is a front end side sectional view of a fuel injection device showing the attachment structure of the conventional nozzle plate.

  Hereinafter, embodiments of the present invention will be described in detail with reference to the drawings.

[First Embodiment]
(Fuel injection device)
FIG. 1 is a diagram schematically showing a use state of the fuel injection device 1 (see FIG. 2). As shown in FIG. 1, a port injection type fuel injection device 1 is installed in the middle of an intake pipe 2 of an engine, injects fuel into the intake pipe 2, and introduces air and fuel introduced into the intake pipe 2. To form a combustible mixture.

  FIG. 2 is a view showing the front end side of the fuel injection device 1 to which the fuel injection device nozzle plate 3 (hereinafter abbreviated as a nozzle plate) is attached. 2A is a front view of the front end side of the fuel injection device 1. FIG. Moreover, FIG.2 (b) is the front end side view of the fuel-injection apparatus 1 seen from the direction shown by the arrow C1 of Fig.2 (a). FIG. 2C is a front-end side cross-sectional view of the fuel injection device 1 shown by cutting the nozzle plate 3 along the line A1-A1 of FIG. FIG. 2D is a front end side sectional view of the fuel injection device 1 cut along the line A1-A1 in FIG.

  As shown in FIG. 2, in the fuel injection device 1, a nozzle plate 3 made of a synthetic resin material is attached to the distal end side of a metal valve body 5 in which a fuel injection port 4 is formed. In the fuel injection device 1, the needle valve 6 is opened and closed by a solenoid (not shown). When the needle valve 6 is opened, fuel in the valve body 5 is injected from the fuel injection port 4. The fuel injected from the port 4 passes through the nozzle holes 7 of the nozzle plate 3 and is injected outside. The valve body 5 has a circular shape when viewed from the front side (see FIG. 5A), and an annular locking groove 8 is formed along the circumferential direction on the outer peripheral surface on the distal end side (see FIG. 5). 5 (a) to (b)). The locking groove 8 has a rectangular cross-sectional shape (a cross-sectional shape along the generatrix of the valve body 5) so that the tip side of the arm portion 10 of the nozzle plate 3 is engaged (FIG. 2 ( c) to (d)). The nozzle plate 3 is injection molded using a synthetic resin material such as PPS, PEEK, POM, PA, PES, PEI, and LCP.

(Nozzle plate mounting structure)
Hereinafter, based on FIG. 2 thru | or FIG. 5, the attachment structure of the nozzle plate 3 which concerns on this embodiment is demonstrated. 3A is a cross-sectional view taken along line A2-A2 in FIG. 2C, and FIG. 3B is cut along line A3-A3 in FIG. It is sectional drawing shown. 4A is a front view of the nozzle plate 3, FIG. 4B is a side view of the nozzle plate 3 viewed from the direction C2 in FIG. 4A, and FIG. 4C is FIG. It is sectional drawing of the nozzle plate 3 cut | disconnected and shown along the A4-A4 line | wire of a). FIG. 5A is a front view of the front end side of the valve body 5, and FIG. 5B is a side view of the front end side of the valve body 5.

  As shown in FIGS. 2 to 5, the nozzle plate 3 closes the cylindrical fitting portion 12 that is press-fitted into the outer peripheral surfaces 11 a and 11 b of the valve body 5 and one end side of the cylindrical fitting portion 12. A pair is formed on the other end side of the bottom wall portion 14 with which the front end surface 13 of the valve body 5 is abutted and the cylindrical fitting portion 12 and is engaged with the locking groove 8 of the valve body 5. And a bottomed cylindrical body integrally having the arm portion 10. In addition, in this embodiment, although the arm part 10 illustrated the aspect formed as a pair in the other end side of the cylindrical fitting part 12, it is not restricted to this, At least the other end side of the cylindrical fitting part 12 is provided. It is sufficient if it is formed at one place.

  The cylindrical fitting portion 12 has a cylindrical shape, and is formed with an inner diameter dimension slightly smaller than an outer diameter dimension of the valve body 5 so as to be fitted to the distal end side of the valve body 5 with an interference fit. ing. One end of the cylindrical fitting portion 12 is closed by the bottom wall portion 14, and the other end is opened so that the distal end side of the valve body 5 can be inserted. Further, the cylindrical fitting portion 12 has a small-diameter hole portion 15 on one end side press-fitted into the small-diameter portion 16 on the distal end side of the valve body 5, and a large-diameter hole portion 17 on the other end side is large-diameter on the distal end side of the valve body 5. It is press-fitted into the part 18. The valve body 5 into which the tubular fitting portion 12 is press-fitted is used for locking between a distal end side small diameter portion 16 connected to the distal end surface 13 and a distal end side large diameter portion 18 positioned away from the distal end surface 13. A groove 8 is formed. The locking groove 8 of the valve body 5 is a recess having a rectangular cross-sectional shape cut along the central axis 20 of the valve body 5 (see FIGS. 2C to 2D and FIG. 5).

  The bottom wall portion 14 has a plurality of nozzle holes 7 (six locations at equal intervals in the circumferential direction) for injecting fuel injected from the fuel injection port 4 of the fuel injection device 1 toward the outside (inside the intake pipe 2). Is formed. The bottom wall portion 14 is a flat surface on the inner surface 21 side (the surface side in close contact with the tip surface 13 of the valve body 5), and the center portion 23 on the outer surface 22 side is recessed. That is, in the bottom wall portion 14, the central portion 23 in which the nozzle hole 7 is formed is a disk-shaped thin portion, is an area surrounding the central portion 23, and is connected to one end side of the tubular fitting portion 12. The peripheral portion 24 is a thick portion formed thicker than the central portion 23. In the present embodiment, a total of six nozzle holes 7 are formed in the bottom wall portion 14, but the present invention is not limited to this, and the optimum number, hole diameter, etc. are determined according to the required fuel injection characteristics. .

  The arm portion 10 is in contact with the arm portion main body 25 whose front end 25 a side is engaged with the locking groove 8 of the valve body 5, the rear end 25 b side of the arm portion main body 25, and the outer peripheral surface 11 b of the valve body 5. It has a projection 26 formed on the inner surface 25 c side of the arm portion main body 25, and an arm portion main body support portion 27 that elastically supports the arm portion main body 25 on the cylindrical fitting portion 12.

  The arm body 25 is substantially contoured by a pair of first axial grooves 28, 28, a pair of second axial grooves 30, 30 and a circumferential groove 31 formed in the cylindrical fitting portion 12. Yes. The first axial grooves 28, 28 are formed so as to cut from one end 32 of the cylindrical fitting portion 12 in a direction along the central axis 20 of the cylindrical fitting portion 12 (a direction along the generatrix). A pair is formed at intervals in the circumferential direction of the cylindrical fitting portion 12. The second axial groove 30 is formed on the extension line (extension line along the central axis 20) of the first axial groove 28 so as to be separated from the first axial groove 28 (with a gap). A pair of elongated holes (grooves extending in the direction along the central axis 20) are formed on the cylindrical fitting portion 12 so as to face the extended lines of the pair of first axial grooves 28, 28. ing. The end portion of the second axial groove 30, 30 that is located closer to the first axial groove 28, 28 is defined as one end side of the second axial groove 30, 30. , 30 and the end located far from the first axial grooves 28, 28 are the other ends of the second axial grooves 30, 30, and the other pair of second axial grooves 30, 30 The end side is connected by the circumferential groove | channel 31 formed along the circumferential direction of the cylindrical fitting part 12. FIG. The pair of first axial grooves 28, 28, the pair of second axial grooves 30, 30, and the circumferential groove 31 penetrate from the outer peripheral surface to the inner surface of the cylindrical fitting portion 12. As described above, the arm portion main body 25 is formed by the pair of first axial grooves 28 and 28, the pair of second axial grooves 30 and 30, and the circumferential groove 31 formed in the cylindrical fitting portion 12. It is separated from the cylindrical fitting part 12 except for the parts (arm part main body support parts 27, 27). The arm body 25 has one end (open end) 32 side of the tubular fitting portion 12 as one end (rear end) 25b, and extends from the one end (open end) 32 of the tubular fitting portion 12 toward the central axis 20. Assuming that the end located far away is the other end (tip) 25a, the substantially intermediate portion between the one end 25b and the other end 25a is elastically supported by the arm portion main body support portions 27 and 27. Further, in the present embodiment, the circumferential groove 31 is inclined so that the edge on the outer peripheral surface side is located closer to the bottom wall portion 14 than the end on the inner peripheral surface side of the cylindrical fitting portion 12. Is formed. As a result, the distal end surface 25d of the arm portion body 25 is inclined with an angle of θ (for example, θ = 10 ° to 45 °) with respect to the virtual straight line 19 orthogonal to the central axis 20 of the cylindrical fitting portion 12. It has become. In addition, as shown in FIG.2 (b) and FIG.4 (b), the shape which looked at the arm part main body 25 from the side surface side of the nozzle plate 3 is substantially rectangular shape.

  The arm portion main body support portions 27 and 27 are left uncut between the pair of first axial grooves 28 and 28 formed in the cylindrical fitting portion 12 and the pair of second axial grooves 30 and 30. Part. The arm portion main body support portions 27, 27 connect both sides of the arm portion main body 25 (both sides in the width direction along the circumferential direction of the cylindrical fitting portion 12) to the cylindrical fitting portion 12. The arm portion main body 25 is elastically supported with respect to the cylindrical fitting portion 12 so that the main body 25 can swing.

  The protrusion 26 is located closer to the one end 32 side (one end 25b side of the arm portion main body 25) of the cylindrical fitting portion 12 than the arm portion main body support portion 27, and when the nozzle plate 3 is press-fitted into the valve body 5, It is a bulge of a rectangular shape formed so as to be able to contact with a large area in the circumferential direction of the valve body 5. The projection 26 has one end 26a near the one end 32 of the cylindrical fitting portion 12 and one end 26a when the end away from the one end 32 of the cylindrical fitting portion 12 along the central axis 20 is the other end 26b. It is formed so as to be located closer to the center axis 20 (radially inward) of the cylindrical fitting portion 12 than the other end 26b. When the cylindrical fitting portion 12 of the nozzle plate 3 is press-fitted into the valve body 5, the projection 26 having such a shape is provided on the one end 25 b side of the arm portion body 25 with the pair of arm portion body support portions 27, 27 serving as fulcrums. Is lifted away from the outer peripheral surface of the valve body 5 as shown in FIG. 3 (b), and the other end (tip) 25a side of the arm body 25 is brought down into the locking groove 8 (FIG. 3 (a) )), And the other end (tip) 25a side of the arm portion body 25 is elastically deformed so as to be crushed, and the tip end surface 25d of the arm portion body 25 is inclined to the edge 35 of the groove wall 33 of the locking groove 8. (The edge 35 formed by the groove wall 33 near the front end surface 13 of the valve body 5 and the outer peripheral surface of the valve body 5 of the pair of groove walls 33, 34 of the locking groove 8) (FIG. 2C) To (d)). As a result, the nozzle plate 3 has an elastic force acting in a direction in which the bottom wall portion 14 is pressed against the distal end surface 13 of the valve body 5 (an elastic force generated by crushing the other end (front end) 25a side of the arm body 25). ) Always works. In order to facilitate the press-fitting work between the cylindrical fitting portion 12 and the valve body 5, it is preferable to chamfer the inner peripheral edge on the one end 32 side of the cylindrical fitting portion 12 and the one end 26a of the protrusion 26. Further, as shown in FIG. 5B, a chamfer 34 a may be formed at the end portion of the distal end side large diameter portion 18 on the locking groove 8 side. The chamfer 34a is a chamfer that can smoothly guide the movement of the one end 25b of the arm portion main body 25 and the projection 26 by an inclined surface in order to facilitate the press-fitting work of the tubular fitting portion 12 and the valve body 5. It is preferable that the inner surface 25c of 25 be chamfered so as not to contact the valve body 5.

(Effect of 1st Embodiment)
According to the mounting structure of the nozzle plate 3 according to the present embodiment as described above, when the cylindrical fitting portion 12 of the nozzle plate 3 is press-fitted into the distal end side of the valve body 5, the protrusion 26 of the arm portion 10 becomes the arm portion main body. 25, the front end 25a side of the valve body 5 is folded into the locking groove 8 of the valve body 5, and the front end 25a side of the arm body 25 is elastically deformed so as to be crushed. Pressed against the edge 35 (the distal end 25a side of the arm body 25 and the locking groove 8 of the valve body 5 are engaged) and fixed to the distal end side of the valve body 5 with the nozzle plate 3 being prevented from coming off. Therefore, as compared with the conventional example in which the metal nozzle plate 103 is welded and fixed to the tip of the metal valve body 102 (see FIG. 9), the number of manufacturing steps of the fuel injection device 1 can be reduced, and the fuel injection device It can reduce the cost of production.

  Further, according to the mounting structure of the nozzle plate 3 according to the present embodiment, after the nozzle plate 3 is press-fitted into the valve body 5, there is a difference in thermal expansion between the nozzle plate 3 made of synthetic resin material and the valve body 5 made of metal. When this occurs, the other end (tip) 25a side of the arm portion body 25 that has been elastically deformed so as to be crushed is elastically restored to absorb the thermal expansion difference between the nozzle plate 3 and the valve body 5, and the arm portion body 25. 25 d can be kept pressed against the edge 35 of the groove wall 33 of the locking groove 8 so that a gap is formed between the bottom wall portion 14 of the nozzle plate 3 and the front end surface 13 of the valve body 5. The elastic force on the other end (tip) 25a side of the arm body 25 that is elastically deformed so as to be crushed opposes the force in the direction of removing the nozzle plate 3 from the valve body 5. As a result, according to the mounting structure of the nozzle plate 3 according to the present embodiment, even if the fuel injection pressure acts on the nozzle plate 3, the nozzle plate 3 does not fall off the valve body 5, and the nozzle plate 3 3 exhibits a desired function (function of atomizing fuel). The nozzle plate 3 made of a synthetic resin material has a larger coefficient of thermal expansion than that of the metal valve body 5, so that the elongation due to thermal expansion is greater than that of the metal valve body 5.

  Further, according to the mounting structure of the nozzle plate 3 according to the present embodiment, when there is a manufacturing error between the valve body 5 and the nozzle plate 3, the other end (tip) 25a side of the arm body 25 is elastically deformed. The manufacturing error of the valve body 5 and the nozzle plate 3 is absorbed by contact with the edge 35 of the groove wall 33 of the stop groove 8, and the other end (tip) 25 a side of the arm portion body 25 and the groove wall of the locking groove 8. The elastic force on the other end (tip) 25a side of the arm body 25, which is elastically deformed so as to be crushed, is maintained in an elastic contact state with the edge 35 of 33, in the direction of removing the nozzle plate 3 from the valve body 5. Opposes power. As a result, according to the mounting structure of the nozzle plate 3 according to the present embodiment, even if there is a manufacturing error between the metal valve body 5 and the synthetic resin material nozzle plate 3, the bottom wall portion 14 of the nozzle plate 3. There is no gap between the valve body 5 and the front end surface 13 of the valve body 5, and the nozzle plate 3 does not fall out of the valve body 5 even if fuel injection pressure acts on the nozzle plate 3.

  Further, according to the mounting structure of the nozzle plate 3 according to the present embodiment, when the cylindrical fitting portion 12 of the nozzle plate 3 is press-fitted into the distal end side of the valve body 5, the protrusion 26 of the arm portion 10 is formed on the arm portion main body 25. The other end (tip) 25a side is folded into the locking groove 8 of the valve body 5, and the other end (tip) 25a of the arm body 25 is elastically deformed so as to be crushed. The nozzle plate 3 is pressed against the edge 35 of the locking groove 8 (the other end (tip) 25a side of the arm body 25 is engaged with the locking groove 8 of the valve body 5), and the nozzle plate 3 is prevented from coming off. In this state, the metal nozzle plate 103 is fixed to the front end side of the valve body 5, so that a defect such as in the conventional example in which the metal nozzle plate 103 is welded and fixed to the front end of the metal valve body 102 (the nozzle hole 104 is blocked by welding spattering). Refers bug) without occurs (see FIG. 9), all the nozzle holes 7 is reliably exhibit the features for fuel atomization.

  As shown in FIGS. 2A and 4A, the arm part 10 is illustrated as a pair formed along the circumferential direction of the cylindrical fitting part 12, but the present invention is not limited to this. It suffices to form at least one place in the cylindrical fitting portion 12, or three or more places in the cylindrical fitting portion 12.

  In the mounting structure of the nozzle plate 3 according to the present embodiment, the front side shape of the nozzle plate 3 and the valve body 5 is not limited to a circle, but a polygonal shape such as a hexagonal shape, a D shape, an oval shape, and other shapes. But you can.

[Second Embodiment]
6 to 8 are views showing the mounting structure of the nozzle plate 3 according to the second embodiment of the present invention. In addition, the description of the attachment structure of the nozzle plate 3 according to the present embodiment will be described by assigning the same reference numerals to the components common to the attachment structure of the nozzle plate 3 of the first embodiment in FIGS. A description overlapping the description of the nozzle plate 3 of the first embodiment is omitted.

  In the mounting structure of the nozzle plate 3 according to the present embodiment, the groove wall 33 near the distal end surface 13 of the pair of groove walls 33 and 34 forming the locking groove 8 of the valve body 5 is an inclined surface, and is cylindrical. When the fitting portion 12 is press-fitted into the distal end side of the valve body 5, the projection 26 pushes up one end (rear end) 25b side of the arm portion main body 25 and the other end (front end) 25a side of the arm portion main body 25 is for locking. For locking in a state where the arm body 25 is collapsed into the groove 8 and elastically deformed so that the other end (tip) 25a side (particularly the inner side in contact with the groove wall 33 as an inclined surface) of the arm body 25 is crushed. The nozzle plate 3 is pressed against a groove wall 33 as an inclined surface of the groove 8 and is fixed to the distal end side of the valve body 5 in a state where the nozzle plate 3 is prevented from coming off.

  According to such a mounting structure of the nozzle plate 3 according to the present embodiment, when a difference in thermal expansion occurs between the metal valve body 5 and the synthetic resin material nozzle plate 3, the locking groove 8 is formed. The other end (tip) 25a side of the arm portion main body 25 that is in contact with the groove wall 33 as an inclined surface in an elastically deformed state is elastically restored to absorb the difference in thermal expansion between the valve body 5 and the nozzle plate 3, and the arm portion. The elastic contact state between the other end (tip) 25a side of the main body 25 and the groove wall 33 as the inclined surface of the locking groove 8 is maintained. The elastic force on the other end (tip) 25a side of the arm main body 25 that has been elastically deformed so as to be crushed opposes the force in the direction of removing the nozzle plate 3 from the valve body 5. As a result, even if a difference in thermal expansion occurs between the metal valve body 5 and the synthetic resin material nozzle plate 3 after the nozzle plate 3 is attached to the distal end side of the valve body 5, the bottom wall portion of the nozzle plate 3. 14 and the tip end surface 13 of the valve body 5, the elastic force on the other end (tip) 25 a side of the arm portion main body 25 that is elastically deformed so as to be crushed does not cause the nozzle plate 3 to move. In order to counteract the force in the direction of removing from the valve body 5, the nozzle plate 3 does not fall off the valve body 5 even if fuel injection pressure acts on the nozzle plate 3.

  Further, according to the mounting structure of the nozzle plate 3 according to the present embodiment, when there is a manufacturing error between the valve body 5 and the nozzle plate 3, the other end (tip) 25a side of the arm body 25 is elastically deformed. The manufacturing error of the valve body 5 and the nozzle plate 3 is absorbed by contact with the groove wall 33 as the inclined surface of the stop groove 8, and the other end (tip) 25 a side of the arm body 25 and the locking groove 8 are inclined. The elastic contact state of the groove wall 33 as a surface is maintained. As a result, according to the mounting structure of the nozzle plate 3 according to the present embodiment, even if there is a manufacturing error between the metal valve body 5 and the synthetic resin material nozzle plate 3, the bottom wall portion 14 of the nozzle plate 3. There is no gap between the valve body 5 and the tip surface 13 of the valve body 5, and the elastic force on the other end (tip) 25a side of the arm body 25 which has been elastically deformed so as to be crushed causes the nozzle plate 3 to move. In order to counteract the force in the direction of removing from the valve body 5, the nozzle plate 3 does not fall off the valve body 5 even if fuel injection pressure acts on the nozzle plate 3.

  According to the mounting structure of the nozzle plate 3 according to the present embodiment as described above, the same effect as the mounting structure of the nozzle plate 3 according to the first embodiment can be obtained. That is, according to the mounting structure of the nozzle plate 3 according to the present embodiment, when the cylindrical fitting portion 12 of the nozzle plate 3 is press-fitted into the distal end side of the valve body 5, the protrusion 26 of the arm portion 10 is formed on the arm portion main body 25. The other end (tip) 25a side is brought down into the locking groove 8 of the valve body 5, and the other end (tip) 25a side of the arm portion body 25 is elastically deformed so as to be crushed. The nozzle plate 3 is pressed against a groove wall 33 as an inclined surface of the locking groove 8 (the other end (tip) 25a side of the arm body 25 is engaged with the locking groove 8 of the valve body 5). Is fixed to the distal end side of the valve body 5 in a state where it is prevented from coming off, compared with a conventional example in which a metal nozzle plate 103 is welded and fixed to the distal end of the metal valve body 102 (see FIG. 9). Injection device 1 Can reduce the number of manufacturing steps, it is possible to reduce the cost of manufacturing the fuel injection device 1.

  Further, according to the mounting structure of the nozzle plate 3 according to the present embodiment, when the cylindrical fitting portion 12 of the nozzle plate 3 is press-fitted into the distal end side of the valve body 5, the protrusion 26 of the arm portion 10 is formed on the arm portion main body 25. The other end (tip) 25a side is brought down into the locking groove 8 of the valve body 5, and the other end (tip) 25a side of the arm portion body 25 is elastically deformed so as to be crushed. The nozzle plate 3 is pressed against a groove wall 33 as an inclined surface of the locking groove 8 (the other end (tip) 25a side of the arm body 25 is engaged with the locking groove 8 of the valve body 5). Since the metal nozzle plate 103 is fixed to the tip of the valve body 102 by welding with the metal nozzle plate 103 being fixed to the tip of the valve body 5 in a state where it is prevented from coming off (nozzle hole by welding sputtering). 1 4 without failure) occurs that is closed (see FIG. 9), all the nozzle holes 7 is reliably exhibit the features for fuel atomization.

  In addition, in this embodiment, although the groove | channel 8 for latching illustrated the structure which made the whole groove wall 33 near the bottom wall part 14 of a pair of groove walls 33 and 34 into an inclined surface, it is not restricted to this. A part of the groove wall 33 may be an inclined surface. Further, in the present embodiment, the distal end surface 25d of the arm portion body 25 is formed so that θ in FIG. 4C is 0 ° (θ = 0 °), but is shown in FIG. 6C. As long as the contact state between the other end (tip) 25a side of the arm body 25 and the groove wall 33 can be maintained, θ> 0 ° may be set.

  DESCRIPTION OF SYMBOLS 1 ... Fuel injection device, 3 ... Nozzle plate (nozzle plate for fuel injection devices), 4 ... Fuel injection port, 5 ... Valve body, 7 ... Nozzle hole, 8 ... Locking groove, 10 ... ... arm part, 12 ... cylindrical fitting part, 13 ... tip surface, 14 ... bottom wall part, 25 ... arm part body, 25a ... other end (tip), 25b ... one end (rear end) 25c ...... Inner surface, 26 ...... Protrusions, 27 ... Arm body support

Claims (4)

In the mounting structure of the nozzle plate for the fuel injection device in which the nozzle hole for atomizing the fuel flowing out from the fuel injection port of the fuel injection device is formed,
The metal valve body of the fuel injection device in which the fuel injection port is formed has an annular locking groove along the outer periphery.
The nozzle plate for the fuel injection device is formed so as to close a cylindrical fitting portion into which the distal end side of the valve body is press-fitted, and one end side of the cylindrical fitting portion, and the distal end surface of the valve body abuts And a bottom wall part in which the nozzle hole is formed, and an arm part formed on the other end side of the cylindrical fitting part and engaged with the locking groove of the valve body,
The cylindrical fitting portion, the bottom wall portion, and the arm portion of the fuel injection device nozzle plate are integrally formed of a synthetic resin material,
The arm portion is formed on the inner surface side of the arm portion main body that is in contact with the outer surface of the valve body on the rear end side of the arm portion main body and the arm portion main body whose front end side is engaged with the locking groove. A protrusion, and an arm part body support part that elastically supports the arm part body on the cylindrical fitting part,
When the cylindrical fitting portion is press-fitted into the valve body, the protrusion causes the arm portion main body support portion to be a fulcrum and the tip side of the arm portion main body is brought down into the locking groove, whereby the arm Even when the distal end side of the main body is pressed against the groove wall of the locking groove and a difference in thermal expansion occurs between the valve body and the nozzle plate for the fuel injection device, the front end side of the arm main body and the locking The contact state between the bottom wall portion and the tip end surface of the valve body is maintained by the elastic force acting on the contact portion of the groove with the groove wall,
A structure for mounting a nozzle plate for a fuel injection device. The contact portion is a contact portion between a front end surface of the arm portion main body and an edge of the groove wall, and a front end surface of the arm portion main body obliquely contacts the edge of the groove wall, and the contact portion The bottom wall portion is pressed against the valve body by an inclined component force caused by the elastic force acting on the valve body,
The nozzle plate mounting structure for a fuel injection device according to claim 1. The contact portion is a contact portion between the distal end side of the arm portion main body and the inclined surface of the groove wall, and the bottom wall portion is caused by a slope component force caused by the elastic force acting on the contact portion. Pressed against the valve body,
The nozzle plate mounting structure for a fuel injection device according to claim 1. The arm part body has a pair of first axial grooves formed so as to be cut from the other end of the cylindrical fitting part in a direction along the central axis of the cylindrical fitting part, and the first axial direction. A pair of second axial grooves formed in the cylindrical fitting portion with a gap in the direction along the central axis direction, and ends of the pair of second axial grooves, and the first Formed by a circumferential groove connecting an end located far from the axial groove along the circumferential direction of the cylindrical fitting portion,
The arm part main body support part is an uncut portion formed between the pair of first axial grooves and the pair of second axial grooves,
The protrusion is located on the other end side of the cylindrical fitting portion with respect to the arm portion main body support portion,
The pair of first axial grooves, the pair of second axial grooves, and the circumferential groove penetrate from the outer peripheral surface side to the inner peripheral surface side of the cylindrical fitting portion.
The nozzle plate mounting structure for a fuel injection device according to any one of claims 1 to 3.

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