Support structure for fuel injection valve

Abstract

The present invention provides a simple structure of a fuel injection valve support structure, which can prevent the fuel injection valve from rotating around the axis of the valve housing even without a special rotation stopper provided on the elastic support member. In the support structure, a notch (19) for receiving the valve housing (1) is provided on the base plate (15) of the elastic support member (S), and a rotation stopper protrusion (20) for engaging with the notch (19) to prevent the fuel injection valve (I) from rotating around the axis (A) of the valve housing (1) is formed on the synthetic resin molded portion (6) which protrudes to one side of the coupler (14) and covers the outer circumferential surface of the valve housing (1).

Description

Technical Field

[0001] This invention relates to a support structure for a fuel injection valve used in an engine, and particularly to an improvement in the support structure of a fuel injection valve in which the fuel nozzle portion of the valve housing is fitted into the injection valve mounting hole of the engine, and a fuel supply cap for a fuel distribution pipe supported by the engine is fitted into the fuel inlet portion of the valve housing. An elastic support member is sandwiched between the valve housing and the fuel supply cap, applying force to the valve housing toward the injection valve mounting hole, thereby elastically clamping the fuel injection valve between the engine and the fuel supply cap to prevent axial movement. Background Technology

[0002] Such a support structure for a fuel injection valve is known, as disclosed in Patent Document 1 below.

[0003] Existing technical documents

[0004] Patent documents

[0005] Patent Document 1: Japanese Patent Application Publication No. 2013-174227 Summary of the Invention

[0006] The problem that the invention aims to solve

[0007] In such a fuel injection valve support structure, during engine operation, when the fuel injection valve rotates slightly around its valve housing axis due to engine vibration, the orientation of the fuel injected from the fuel nozzle changes, adversely affecting the combustion state of the fuel in the engine. Therefore, in the fuel injection valve support structure described in Patent Document 1, a pair of anti-rotation plates extending curvedly from both ends toward the fuel nozzle side are continuously provided on the base plate of the aforementioned elastic support member, and these anti-rotation plates abut against the flat surfaces formed on both sides of the valve housing to prevent the aforementioned rotation of the fuel injection valve.

[0008] However, the above-mentioned support structure has the following disadvantages: continuously setting a pair of anti-rotation plates on the base plate will make the shape of the elastic support component complicated, increase the processing steps, and reduce the yield of raw materials, resulting in an increase in the cost of the support structure.

[0009] The present invention was made in view of the following circumstances, and its object is to provide a support structure for a fuel injection valve with a simple structure that can prevent the fuel injection valve from rotating about the axis of the valve body even without setting a special anti-rotation plate on the elastic support component.

[0010] Methods for solving problems

[0011] To achieve the above objectives, a first feature of the present invention is a support structure for a fuel injection valve, wherein a fuel nozzle portion of the valve housing is fitted into an injection valve mounting hole of an engine, a fuel supply cap for a fuel distribution pipe supported by the engine is fitted into the fuel inlet portion of the valve housing, and an elastic support member is sandwiched between the valve housing and the fuel supply cap. The elastic support member exerts force on the valve housing toward the injection valve mounting hole and is connected to the fuel supply cap in a manner that prevents rotation about the axis of the valve housing. The elastic support member comprises: a base plate abutting against a base surface of a synthetic resin molded portion opposite to the fuel supply cap, the synthetic resin molded portion protruding to one side for use with a power supply coupler and covering the outer peripheral surface of the valve housing; and an elastic sheet extending from one end of the base plate and elastically contacting the fuel supply cap, wherein a notch for receiving the valve housing is provided on the base plate, and an anti-rotation protrusion engaging with the notch to prevent the fuel injection valve from rotating about the axis of the valve housing is formed in the synthetic resin molded portion.

[0012] In addition to the first feature, the second feature of the present invention is that the elastic sheet is formed as a pair in such a way that it spans the valve housing and the end portion overlaps with the end portion of the base plate, and the anti-rotation protrusion is also engaged between the end portions of the pair of elastic sheets.

[0013] Furthermore, in addition to the first or second feature, a third feature of the invention is that the anti-rotation protrusion is disposed between the valve housing and the coupler.

[0014] Invention Effects

[0015] According to a first feature of the invention, a notch for receiving the valve housing is provided on the base plate of the elastic support member, and an anti-rotation protrusion that engages with the notch is formed in the synthetic resin molding portion covering the valve housing. This prevents the fuel injection valve from rotating about the axis of the valve housing, ensuring a stable orientation of the injected fuel from the fuel nozzle barrel. Therefore, it is unnecessary to continuously provide a pair of complex-shaped anti-rotation plates on the elastic support member. Furthermore, the aforementioned anti-rotation protrusion can be integrally molded with the coupler into the synthetic resin molding portion covering the valve housing. This reduces the cost of the fuel injection valve support structure without increasing the number of parts processed and improves the yield of raw materials.

[0016] Furthermore, according to a second feature of the invention, the ends of a pair of elastic plates spanning the valve housing of the elastic support member overlap with the ends of the base plate, and the anti-rotation protrusion also engages between the ends of the pair of elastic plates. This enhances the engagement force between the elastic support member and the anti-rotation protrusion, thereby reliably preventing the rotation of the fuel injection valve.

[0017] Furthermore, according to a third feature of the invention, the protrusion is disposed between the valve housing and the coupler. Therefore, when the elastic support member is inserted between the fuel injection valve and the fuel supply pipe, by inserting it from the side opposite to the coupler, the elastic support member can be easily engaged with the anti-rotation protrusion without interfering with the coupler, resulting in good assemblability. Attached Figure Description

[0018] Figure 1 This is a partial longitudinal sectional front view showing the support structure of the fuel injection valve in a multi-cylinder engine according to an embodiment of the present invention.

[0019] Figure 2 yes Figure 1 Enlarged sectional view along line 2-2.

[0020] Figure 3 yes Figure 2 3-3 line section view.

[0021] Figure 4 These are individual three-dimensional views of the elastic support components in each figure. Detailed Implementation

[0022] The embodiments of the present invention will be described with reference to the accompanying drawings.

[0023] First of all, Figure 1 and Figure 2 In this multi-cylinder engine E, multiple fuel injection valves I capable of injecting fuel into the combustion chambers Ec of multiple cylinders are mounted on the cylinder head Eh, along with a fuel distribution pipe D that distributes fuel to these fuel injection valves I. Furthermore, in order to hold each fuel injection valve I in a fixed position, an elastic support structure with an elastic support member S is used. This structure will be described in detail below.

[0024] Each fuel injection valve I has a cylindrical valve body 1 at its center. The front end of the valve body 1 becomes the fuel nozzle cylinder 2, the rear end becomes the fuel inlet cylinder 4, and the middle part becomes the electromagnetic coil 3. When the electromagnetic coil 3 is energized, the valve inside the fuel nozzle cylinder 2 is opened, and the fuel inlet cylinder 4 injects the fuel introduced from the fuel distribution pipe D into the corresponding combustion chamber Ec.

[0025] In addition, the electromagnetic coil section 3 is covered by the synthetic resin molding section 6, and a coupler 14 for supplying power to the electromagnetic coil section 3 is integrally provided on one side of the synthetic resin molding section 6.

[0026] An annular sealing and buffering member 8 is installed on the outer periphery of the fuel nozzle cylinder 2, which is in close contact with the front end face of the synthetic resin molding part 6. In addition, an O-ring 9 is installed in the sealing groove 4a on the outer periphery of the fuel inlet cylinder 4.

[0027] In addition, the rear end face of the synthetic resin molding part 6 facing the fuel inlet cylinder part 4 is a flat base surface 5.

[0028] On the other hand, the cylinder head Eh is provided with an injection valve mounting hole 10 with its inner end opening to the top surface of each combustion chamber Ec and an annular recess 11 surrounding its outer opening end. The fuel nozzle cylinder 2 of the fuel injection valve I is embedded in the injection valve mounting hole 10, and a sealing and buffering component 8 is housed in the recess 11.

[0029] Furthermore, the fuel distribution pipe D is arranged along the arrangement direction of the multiple cylinders of the engine E, and fuel is pumped from one end by a fuel pump (not shown). Multiple fuel supply caps Da are protruding from one side of the fuel distribution pipe D and arranged coaxially with the multiple fuel injection valves I fitted into the multiple injection valve mounting holes 10. These fuel supply caps Da are respectively fitted into the outer periphery of the fuel inlet cylinder 4 of the corresponding fuel injection valve I. At this time, the O-ring 9 is in close contact with the inner circumferential surface of the fuel supply cap Da. A flat stop surface 7 parallel to the axis A of the valve housing 1 is formed on the outer surface of each fuel supply cap Da. A bracket Db is fixedly provided at the base of each fuel supply cap Da, and the bracket Db is fixed by bolts 13 to a support column 12 erected on the upper surface of the cylinder head Eh.

[0030] like Figures 2 to 4 As shown, the above-mentioned elastic support component S is made by stamping steel plate and consists of base plate 15, elastic sheet 16 and positioning sheet 18.

[0031] The base plate 15 overlaps with the base surface 5, and has a U-shaped notch 19 at its center to accommodate the valve housing 1. A pair of elastic pieces 16 are integrally connected to one end of the base plate 15 opposite to the U-shaped notch 19, and are in elastic contact with the front end face of the fuel supply cover Da. The two elastic pieces 16 are arranged such that they are spaced apart by a gap that can accommodate the fuel inlet cylinder 4 of the fuel injection valve I.

[0032] Each elastic sheet 16 is composed of a first elastic portion 16a and a second elastic portion 16b. The first elastic portion 16a bends upward from one end of the base plate 15 into a transverse U-shape. The second elastic portion 16b bends upward from the first elastic portion 16a and extends toward the other end, with its end portion 16ba slidably elastically contacting the upper surface of the base plate 15. The radius of curvature R2 of the second elastic portion 16b is set to be sufficiently larger than the radius of curvature R1 of the first elastic portion 16a (see reference). Figure 4 ).

[0033] Furthermore, in the free state of the elastic sheet 16, the distance L1 from the apex of the second elastic part 16b to the lower surface of the base plate 15 (refer to...) Figure 4The distance L2 from the base surface 5 to the front end surface of the fuel supply cover Da is set to (refer to...). Figure 2 Therefore, when the base plate 15 and the elastic sheet 16 are inserted between the base surface 5 and the fuel supply cover Da, the elastic sheet 16 causes the first and second elastic portions 16a and 16b to flex and elastically contact the front end face of the fuel supply cover Da. When the first and second elastic portions 16a and 16b flex, the end portion 16ba of the second elastic portion 16b can slide on the upper surface of the base plate 15, and in order to make its sliding smooth, it becomes an upwardly curved shape.

[0034] A positioning piece 18 is integrally and continuously provided at one end of the base plate 15, which rises vertically upward from between a pair of elastic pieces 16. The positioning piece 18 can abut against the stop surface 7 of the fuel supply cover Da.

[0035] In addition, an anti-rotation protrusion 20 is integrally formed on the synthetic resin molding part 6, protruding from the base surface 5 between the valve housing 1 and the coupler 14. When the elastic support member S is positioned in a fixed position between the synthetic resin molding part 6 and the fuel supply cover Da, the anti-rotation protrusion 20 engages between the notch 19 of the base plate 15 and the end portions 16ba of a pair of elastic sheets 16 that are in elastic contact with the base plate 15.

[0036] Next, the function of this implementation method will be explained.

[0037] When installing the fuel injection valve I onto the engine E, firstly, the fuel supply cap Da of the fuel distribution pipe D is installed on the fuel inlet cylinder 4 of the fuel injection valve I. Next, with the opening of the U-shaped notch 19 of the base plate 15 as the lead, the elastic support member S is inserted from the outside of the fuel injection valve I on the side opposite to the coupler 14 between the base surface 5 of the fuel injection valve I and the fuel supply cap Da, accommodating the valve housing 1 between the notch 19 of the base plate 15 and a pair of elastic plates 16, and the positioning plate 18 abuts against the stop surface 7 of the fuel supply cap Da.

[0038] Due to this contact, the elastic support component S cannot rotate relative to the fuel supply cover Da.

[0039] In addition, while the above-mentioned contact occurs, the anti-rotation protrusion 20 of the synthetic resin molding part 6 engages between the notch 19 of the base plate 15 of the elastic support member S and a pair of elastic sheets 16, thereby preventing the rotation of the fuel injection valve I relative to the fuel supply cover Da around the axis A of the valve housing 1.

[0040] Then, the fuel nozzle cylinder 2 of the aforementioned fuel injection valve I is inserted into the injection valve mounting hole 10 of the cylinder head Eh, and the sealing and buffering component 8, which is in close contact with the front end face of the synthetic resin molding part 6, is housed in the recess 11. Then, while applying a compressive load to the elastic support component S, the bracket Db is fixed to the support column 12 of the cylinder head Eh with bolts 13.

[0041] At this time, a pair of elastic plates 16 cause the first and second elastic portions 16a and 16b to flex and elastically press the front end face of the fuel supply cover Da on the plane containing the axis A of the valve housing 1 through the vertex of the second elastic portion 16b. The pressing reaction force presses the base plate 15 against the base surface 5. Therefore, the fuel injection valve I is elastically clamped between the cylinder head Eh and the fuel supply cover Da via the elastic support member S and the sealing and buffering member 8. Moreover, the pressing reaction force of the elastic plate 16 on the fuel supply cover Da acts on the fuel injection valve I along its central axis A, so that the fuel injection valve I will not tilt and can be stably supported.

[0042] In this way, the rotation of the fuel injection valve I mounted on the engine E relative to the fuel supply cover Da about the axis A of the valve housing 1 is prevented via the elastic support member S, thereby ensuring that the orientation of the injected fuel from the fuel nozzle cylinder 2 remains stable.

[0043] Furthermore, the anti-rotation of the fuel injection valve I relative to the axis A of the valve housing 1 around the elastic support member S is achieved, as described above, by engaging the anti-rotation protrusion 20 of the synthetic resin molding portion 6 between the notch 19 of the base plate 15 and the pair of elastic plates 16 that are originally provided in the elastic support member S. Therefore, it is not necessary to have the special anti-rotation plates as in the past on the elastic support member S, which simplifies the shape of the elastic support member S. In addition, the anti-rotation protrusion 20 and the coupler 14 are integrally molded on the synthetic resin molding portion 6 that covers the valve housing 1 in a manner that surrounds the electromagnetic coil portion 3. Therefore, the number of parts to be processed is not increased, and the yield of raw materials can be improved, thereby reducing the cost of the support structure for the fuel injection valve I.

[0044] Furthermore, in this invention, in order to engage only the notch 19 of the base plate 15 with the anti-rotation protrusion 20, for example, the height of the anti-rotation protrusion 20 can be set to be equal to the thickness of the base plate 15, or the ends 16ba of the pair of elastic plates 16 can end in front of the anti-rotation protrusion 20. However, as mentioned above, if both the base plate 15 and the elastic plates 16 are engaged with the anti-rotation protrusion 20, the engagement force between the elastic support member S and the anti-rotation protrusion 20 can be enhanced, and the rotation of the fuel injection valve I can be reliably prevented.

[0045] Furthermore, since the aforementioned anti-rotation protrusion 20 is disposed between the valve housing 1 and the coupler 14, when the elastic support member S is inserted between the fuel injection valve I and the fuel supply cover Da, by inserting it from the side opposite to the coupler 14, the elastic support member S can be easily engaged with the anti-rotation protrusion 20 without interfering with the coupler 14, resulting in good assembly.

[0046] Furthermore, each elastic piece 16 is composed of a first elastic portion 16a and a second elastic portion 16b. The first elastic portion 16a is connected to one end of the base plate 15 and has a small radius of curvature R1. The second elastic portion 16b extends from the first elastic portion 16a and its end portion 16ba slidably abuts against the upper surface of the other end of the base plate 15 and has a large radius of curvature R2. Therefore, the second elastic portion 16b is supported on the base plate 15 at both ends via the end portion 16ba and the first elastic portion 16a. Thus, even if the first elastic portion 16a undergoes plastic deformation (generally, the part that is bent by reducing the radius of curvature is prone to plastic deformation), the elastic force of the second elastic portion 16b can maintain the force application function of each elastic piece 16 on the fuel supply cover Da. Furthermore, by making the radius of curvature R2 of the second elastic part 16b larger than the radius of curvature R1 of the first elastic part 16a, the height of each elastic piece 16 can be suppressed to a very low level, making it easy to install the elastic support member S into the narrow space between the base surface 5 and the fuel supply cover Da.

[0047] The embodiments of the present invention have been described above, but the present invention is not limited thereto, and various modifications can be made without departing from its spirit. For example, the present invention can also be applied to a structure in which a fuel injection valve I is installed in the intake system of an engine.

[0048] Symbol Explanation

[0049] A: The axis of the valve body;

[0050] D: Fuel distribution pipe;

[0051] Da: Fuel supply cover;

[0052] E: Engine;

[0053] I: Electromagnetic fuel injection valve;

[0054] S: Elastic support component;

[0055] 2: Fuel nozzle cylinder section;

[0056] 3: Electromagnetic coil section;

[0057] 4: Fuel inlet cylinder;

[0058] 5: Base surface;

[0059] 6: Synthetic resin molding section;

[0060] 7: Stop surface;

[0061] 10: Injection valve mounting hole;

[0062] 14: Coupler;

[0063] 15: Base plate;

[0064] 16: Elastic sheet;

[0065] 16ba: The end portion of the elastic sheet;

[0066] 18: Positioning plate;

[0067] 19: Gap;

[0068] 20: Stopping the rotation and rising abruptly.

Claims

1. A support structure for a fuel injection valve, wherein a fuel nozzle cylinder (2) of a valve housing (1) is fitted into an injection valve mounting hole (10) of an engine (E), a fuel supply cap (Da) of a fuel distribution pipe (D) supported by the engine (E) is fitted into a fuel inlet cylinder (4) of the valve housing (1), and an elastic support member (S) is sandwiched between the valve housing (1) and the fuel supply cap (Da), the elastic support member (S) exerting force on the valve housing (1) toward the injection valve mounting hole (10) and being connected to the fuel supply cap (Da) in a manner that prevents rotation about the axis (A) of the valve housing (1). The elastic support member (S) consists of the following components: a base plate (15) abutting against the base surface (5) of the valve housing (1) opposite to the fuel supply cap (Da); and an elastic sheet (16) extending from one end of the base plate (15) and elastically contacting the fuel supply cap (Da). The base plate (15) has a notch (19) for receiving the valve housing (1), characterized in that, The valve housing (1) protrudes to one side from the power supply coupler (14) and is covered by a synthetic resin molding part (6). The base surface (5) is formed by the rear end surface of the synthetic resin molding part (6). The synthetic resin molding section (6) includes the following components: An extension plane extends from the end edge of the base surface (5) to the coupler (14) and forms a plane with the base surface (5); and An anti-rotation protrusion (20), which protrudes from the transition portion and engages with the notch (19), prevents the fuel injection valve (I) from rotating about the axis (A) of the valve housing (1), the transition portion extending across the extended plane from the base surface (5) in the plane. The anti-rotation protrusion (20) is disposed between the valve housing (1) and the coupler (14), and the width of the notch (19) that engages with it is formed to be approximately the same as the outer diameter of the fuel inlet cylinder (4) that is configured to protrude from the base surface (5).

2. The support structure for the fuel injection valve according to claim 1, characterized in that, The elastic sheet (16) is formed as a pair across the valve housing (1) and with its end portion (16ba) overlapping the end portion of the base plate (15), and the anti-rotation protrusion (20) also engages between the ends of the pair of elastic sheets (16).

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