JPH1182240A - Injection valve - Google Patents

Abstract

PROBLEM TO BE SOLVED: To miniaturize with a simple structure, to improve manufacturing- ability such as assembling-ability and adjusting workability, and to improve function characteristics such as injection responsibility and preventing fuel leakage. SOLUTION: An energizing mean to energize and hold a steel ball valve body 6 (valve body) to a sheet surface 2b is a leaf spring having a support arm extending toward the steel ball valve body 6, a circularly stamped out part as an opening along an outline of the support arm, a fan-shaped cut-out, and an injection hole 7g to inject fluid, and rubber elastic sheet 8 is provided.

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to an injection valve which opens a valve by the pressure of a supplied fluid to inject the fluid, improves the response at the time of the injection, and is easy to assemble and adjust with a simple structure. Technology for

[0002]

2. Description of the Related Art Conventionally, as an injection valve of this type, for example, a valve element is provided at an intake portion of an engine to create a mixture to drive the engine, and a valve body is opened by pressurized fuel pressure. At the same time, there is a fuel injection valve that injects fuel. FIGS. 5A and 5B are views for explaining the cross-sectional configuration of the fuel injection valve 101. FIG. 5A shows the entire configuration, and FIG. FIG. 3 is an enlarged view of a nozzle tip portion.

[0003] Fuel which is pressurized to a predetermined pressure in accordance with the fuel injection timing is supplied to a fuel injection valve 101 through a fuel supply pipe 102.

[0004] The fuel supply pipe 102 is provided with a fixed flange portion 102 a protruding in a flange shape at the tip end thereof, and a connection hole 103 a provided at one end of the connection sleeve 103.
Is fixed by an O-ring 104 and a fixing plug 105 while maintaining the hermeticity.

[0005] A cylindrical body 106 of the fuel injection valve 101 is hermetically fixed to a connection hole 103b provided at the other end of the connection sleeve 103 by press-fitting or the like. A sleeve 107 is fitted and fixed to the inner periphery of the injection side of the body 106, and a valve seat 108 is fitted and fixed to the inner periphery of the sleeve 107.

[0006] The valve seat 108 has a valve body 109 composed of a spherical steel ball valve 109a in contact with the valve seat surface 108a and a rod 109b connected thereto.

A spring retainer 109c is fixed to the rod 109b on the side opposite to the steel ball valve element 109a. The spring retainer 109c is urged upward in the drawing by a spring 110 having the end of the sleeve 107 on the side of the fuel supply pipe 102 as a fixed pedestal, so that the steel ball valve body 109a is kept closed. I have to.

At the end of the valve seat 108 on the ejection side,
A nozzle plate 111 having a fuel injection hole 111a for atomizing and injecting fuel is attached to the tip. 1
Reference numeral 12 denotes a cylindrical nozzle cap for protecting the tip of the fuel injection valve 101.

The operation of the fuel injection valve 101 will be briefly described. The fuel supplied at a predetermined pressure by the fuel supply pipe 102 is supplied to the connection chamber 11 in which the spring 110 is accommodated.
3. The sleeve 107 is guided to the steel ball valve element 109a through the passage 108b at the inner diameter portion of the valve seat 108, presses the steel ball valve element 109a with a predetermined pressure to open the valve, and is injected from the fuel injection hole 111a. .

The injection timing and injection amount according to the state of the engine are determined by a control unit (not shown). A fuel pressurizing pump, a pressure regulator that regulates the pressure of the pressurized fuel within a certain range, and a distribution device that includes an electromagnetic valve that regulates the flow rate allow the engine to operate while intermittent pressure waves are generated. The fuel is distributed and supplied to a predetermined number of fuel supply pipes 102 according to the model and the number of cylinders, and is injected from each fuel injection valve.

Accordingly, the fuel injection valve 101 is opened by the pressure of the supplied fuel. When the fuel is below a predetermined pressure, the valve is held in the valve closing direction and the fuel is not injected but supplied. Only when the pressure of the fuel is high, the valve is opened and fuel is injected.

[0012]

However, the fuel injection valve 101 having such a structure is required to be further improved in order to maintain the competitiveness of products by solving the following problems.

A) The configuration of the fuel injection valve 101 is complicated and large.

B) The valve body 109 is assembled by pressing the valve seat 108 into the sleeve 107,
And the spring 110 are combined and mounted, and then the tip of the rod 109b and the steel ball valve element 109a are welded in the vicinity of the valve seat surface 108a of the valve seat 108. Low in nature.

C) The components constituting the movable portion when the valve is opened are the spring 110, the spring retainer 109c, the rod 109b and the steel ball valve element 109a, and the mass of the movable portion increases. Therefore, the responsiveness at the time of applying the pressure is deteriorated, and the injection flow rate characteristics particularly when the pulse width is short are reduced.

By the way, in order to solve the above problem,
First, it is conceivable to simplify the configuration of the fuel injection valve.
Therefore, referring to U.S. Pat. No. 4,932,374, there is an example in which a nozzle portion 200 of an injection valve is formed using a diaphragm as shown in FIG.

FIG. 6A is a sectional view of a main part of the nozzle portion 200, FIG. 6B is a view taken in the direction of arrows V101-V101 in FIG. 6A, and FIG. It is a figure explaining the state where it is injected.

The structure of the nozzle 200 is such that the closed end 20 having a communication hole 202 at the center at one end 201a.
3 and the cylindrical sleeve 20
And a diaphragm 205 made of a thin disk-shaped member that covers the outside of the one closed end 203.

The diaphragm 205 has a plurality of injection holes 206 at positions outside the communication hole 202 which are not opposed to each other.
When the fuel at a predetermined pressure is supplied to the sleeve 201, the diaphragm 205 is moved by the fuel supply pressure as shown in FIG.
As shown in (c), the fuel cell is deformed so as to expand outward, and fuel is injected from the injection hole 206 along a path indicated by an arrow A101.

However, in the configuration of the nozzle portion 200, since the communication hole 202 is closed by the central region 205a of the diaphragm 205 when the fuel is not injected, it is difficult to completely close the valve, and the fuel leakage Is likely to occur easily.

Further, since the valve opening pressure is the pressure of the fuel which deforms the diaphragm 205 from the communication hole 202, it is difficult to easily change the valve opening pressure at the time of assembling or after assembling. There is a problem that the variation becomes large, and it is impossible to use the fuel injection valve 101 shown in FIG.

SUMMARY OF THE INVENTION The present invention has been made to solve the above-mentioned problems of the prior art, and its object is to provide a simple structure that can be reduced in size, and to assemble and adjust workability. It is an object of the present invention to provide an injection valve that achieves improved fuel economy and improved functional characteristics such as injection responsiveness and fuel leakage prevention.

[0023]

In order to achieve the above object, according to the present invention, there is provided a valve body contacting a seat surface formed at one end of a cylindrical valve seat member, and the valve body is provided with the valve body. Biasing means for biasing the surface to close the valve,
An injection valve, in which the valve body is separated from the seat surface and opened by the pressure of the fluid supplied to the valve seat member against the urging force of the urging means. A leaf spring having a support arm extending toward the front, an opening along the contour of the support arm, and an ejection hole for ejecting a fluid, and a rubber-like elastic film for preventing leakage of fluid from the opening of the leaf spring. It is characterized by having.

As a result, the valve body is urged by the support arm of the leaf spring. Then, when the valve element is opened by the pressure of the fluid, the fluid flowing out of the gap between the seat surface and the valve element is
It is injected to the outside from the injection hole provided in the leaf spring.

Further, the leaf spring has a disk shape, and its support arm is formed by a plurality of cuts extending from the center to the outer periphery. The rubber-like elastic film covers at least one surface of the leaf spring. It is also preferable to have a feature.

Thus, the support arm can stably urge the valve body, and can cover the cut for forming the support arm with the rubber-like elastic film.

[0027] It is also preferable that a leaf spring holding member is provided which can adjust the urging force of the supporting arm to the valve body by changing the position of the leaf spring with respect to the seat surface.

Thus, the urging force of the support arm against the valve body can be adjusted, and the valve opening pressure of the injection valve can be adjusted.

[0029]

DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS An injection valve according to an embodiment of the present invention will be described below with reference to FIG. The injection valve 1 is provided in an intake section of the engine, for example, in order to create an air-fuel mixture for driving the engine, and has an injection timing and an injection amount according to an engine state determined by a control unit (not shown). As used to inject fuel as a fluid.

The injection valve 1 used for such a purpose has an electromagnetic valve which is pressurized to a constant pressure by a fuel pressurizing pump and a pressure regulator (not shown) and which opens and closes at a predetermined timing. Provides fuel with intermittent pressure waves. Then, the injection valve 1 opens according to the pressure of the fuel to inject the fuel.

(Embodiment 1) FIG. 1 (a) is an explanatory sectional view of an injection valve 1 according to a first embodiment of the present invention, and FIG. 1 (b) is a sectional view of FIG. 1 (a). FIG. 1C is an enlarged view of the nozzle tip, and FIG. 1B is a view of FIG. 1B viewed from the arrow V1-V1.

The injection valve 1 has a fuel supply pipe 3 at one end (upper end in the figure) of a cylindrical valve seat member 2.
The ring 4 and the plug 5 are connected and fixed while maintaining the hermeticity. Then, the fuel is introduced by the fuel supply pipe 3 through the inner diameter portion 2a of the valve seat 2 to the seat surface 2b formed at the other end.

The steel ball valve 6 is in contact with the seat surface 2b, and closes the flow path when the steel ball valve 6 is in the closed state.

The steel ball valve 6 is urged and supported in the valve closing direction by a leaf spring 7 as urging means. Leaf spring 7
Has a disk shape, and both sides are covered with a thin rubber-like elastic film 8.

As shown in FIG. 2 (a), the leaf spring 7 has a circular punched portion 7a at the center of the disk, and four fan-shaped cuts 7b (a plurality of notches 7b) extending from the circular punched portion 7a toward the outer periphery. ) Is formed. And between the oblique sides 7c (plurality) of the adjacent fan-shaped cuts 7b are support arms 7d (plurality) for urging the steel ball valve 6.

Each support arm 7d is provided at the outer peripheral end 7e of the leaf spring 7.
The tip portion 7f (a part of the contour of the circular punched portion 7a) is bent so as to rise in the axial direction toward the steel ball valve body 6 so as to correspond to the valve opening stroke of the steel ball valve body 6.

In the region between the outer peripheral end 7e and the root of the support arm 7d, two injection holes 7g for injecting fuel are provided in this embodiment so as to face each other. Although the injection hole 7g can be provided in the support arm 7d, it is preferable to provide the injection hole in a region other than the support arm 7d in order to stabilize the injection direction and the injection shape.

The rubber-like elastic film 8 is integrally formed on both surfaces of the leaf spring 7 by a method such as vulcanization molding or adhesive bonding.
A circular punched portion 7a as an opening of the leaf spring 7 and a fan-shaped cut 7b are covered. However, only the periphery of the injection hole 7g is not provided as the opening 8a.

Accordingly, when viewed from the nozzle tip side of the injection valve 1 as shown in FIG. 1 (c), the rubber-like elastic film 8 indicated by oblique lines appears on the surface, and the leaf spring 7 The injection hole 7 which is hidden inside and located at the opening 8a
It is not possible to look directly at places other than g.

The leaf spring 7 has an outer peripheral end 7e (covered by the rubber-like elastic film 8) supported by an inward flange 9a of a nozzle sleeve 9 as a leaf spring holding member. The adjustment of the urging force (set load) on the steel ball valve element 6 can be performed by adjusting the relative positional relationship between the nozzle sleeve 9 and the valve seat member 2 in the axial direction. In this embodiment, the position at which the nozzle sleeve 9 is press-fitted to the valve seat member 2 during assembly is determined.

The joint between the nozzle sleeve 9 and the leaf spring 7 is sealed by caulking or the like, and the fuel flowing into the gap 10 between the end face 2c of the valve seat member 2 and the leaf spring 7 is injected into the injection hole. Leaks other than 7 g are eliminated. Therefore, the gap 10 is a chamber closed by the end face 2 c of the valve seat member 2, the leaf spring 7, and the axial wall 9 b of the nozzle sleeve 9.

According to the injection valve 1 having such a configuration, the steel ball valve element 6 urged in the valve closing direction by the leaf spring 7 resists the urging force due to the pressure of the fuel pressurized and supplied at the injection timing. Then, when the valve moves in the injection direction (downward in the figure) and the valve is opened, fuel is supplied from the seat surface 2b, passes through the gap 10, and is injected from the injection hole 7g.

At other than the injection timing, the pressure of the supplied fuel is low, and the steel ball valve 6 is urged by the leaf spring 7 to be in the valve closed state.

Accordingly, the urging and holding of the steel ball valve body 6 against the seat surface 2b can be performed by the leaf spring 7 having a simple configuration, and the configuration of the injection valve 1 can be simplified and downsized. Along with this, adjustment of the assembling and the set load can be easily performed, and the manufacturability can be improved.

The use of a steel ball valve 6 as the valve mechanism results in less fuel leakage when the valve is closed, and a smooth flow without obstructing the flow of fuel passing through the seat surface when the valve is opened. Further, since the urging means is constituted by the leaf spring 7, the structure and mass of the movable portion can be reduced, and the functional characteristics such as the ejection responsiveness can be improved.

When it is necessary to change the set load and the urging stroke of the leaf spring 7 with respect to the steel ball valve 6,
By changing the thickness of the support arm 7d, or as shown in FIG.
As shown in FIG. 7, the cut-out groove 7b 'that bends in the circumferential direction from the circular punched portion 7a' allows the U-shaped support arm 7 to be bent.
It is also possible to form d '. Also in this case, the cut groove 7b 'serving as the opening is covered with the rubber-like elastic film, and the fuel does not leak from the cut groove 7b'.

(Embodiment 2) FIG. 3 is a sectional view showing a main part of a nozzle tip of an injection valve 21 according to a second embodiment. In this figure, the same components as those in the first embodiment are denoted by the same reference numerals, and description thereof will be omitted.

In this embodiment, a rubber-like elastic member 28 covering the surface of the leaf spring 27 is formed only on the surface opposite to the steel ball valve 6.

Therefore, since the steel ball valve 6 is in direct contact with the support arm 27d of the leaf spring 27, the rubber-like elastic member 28 at the portion in contact with the steel ball valve 6 due to long-term use is deteriorated or deformed. Alternatively, it is possible to prevent problems due to damage.

That is, the valve opening pressure is stabilized by stabilizing the set load, and the injection shape of the injected fuel can be made constant. Other functions and effects are the same as those of the injection valve 1 of the first embodiment.

(Embodiment 3) FIG. 4 is a sectional view showing a main part of a configuration of a nozzle tip of an injection valve 31 according to a third embodiment. In this figure, the same components as those in the first embodiment are denoted by the same reference numerals, and description thereof will be omitted.

In the injection valve 31 of the third embodiment, the bending direction of the leaf spring 37 for urging the steel ball valve 6 is opposite to that of the first and second embodiments. It has a cross-sectional shape that swells.

Rubber-like elastic member 3 covering the surface of leaf spring 37
8 is formed on the entire surface opposite to the steel ball valve 6 and on the outer peripheral portion of the surface of the steel ball valve 6. The injection hole 37g is formed on the support arm 37d at a position close to the sheet surface 2b.

As described above, by making the bending direction of the leaf spring 37 outward, the volume of the gap 10 ′ between the end face 2 c of the valve seat member 2 and the leaf spring 37 can be set small, and the fuel Can be reduced. Further, since the injection holes 37g are provided in the region where the pressure loss is small, it is possible to obtain a well-formed fuel injection shape.

[0055]

According to the present invention, the biasing and holding of the valve element can be performed by a leaf spring having a simple structure, and the structure of the injection valve can be simplified and downsized.

As a result, adjustment of the assembling and set load can be easily performed, and the manufacturability can be improved.

Further, since the valve mechanism closes the valve body, fuel leakage at the time of closing the valve is small, the structure and mass of the movable portion are reduced, and the injection responsiveness can be improved.

[Brief description of the drawings]

FIG. 1 (a) is an explanatory view of a cross-sectional configuration of an injection valve according to a first embodiment, FIG. 1 (b) is an enlarged view of a nozzle portion thereof, and FIG. 1 (c) is an arrow V1. FIG.

FIG. 2 is a view of a leaf spring.

FIG. 3 is an enlarged sectional view of a nozzle portion of an injection valve according to a second embodiment.

FIG. 4 is an enlarged sectional view of a nozzle portion of an injection valve according to a third embodiment.

FIG. 5 is an explanatory view of a cross-sectional configuration of a conventional injection valve.

FIG. 6 is an explanatory view of a cross-sectional configuration of a nozzle portion of a conventional injection valve.

[Explanation of symbols]

 1, 21, 31 Injection valve 2 Valve seat member 2a Inner diameter portion 2b Seat surface 3 Fuel supply pipe 4 O-ring 5 Plug 6 Steel ball valve (valve) 7 Leaf spring (biasing means) 7a Circular punched portion 7b Sector-shaped Notch 7c Oblique side 7d Support arm 7e Outer end 7f Tip 7g Injection hole 8 Rubber-like elastic film 8a Opening 9 Nozzle sleeve (leaf spring holding member) 9a Flange 9b Axial wall 10 Gap

Claims (3)

[Claims] 1. A valve body contacting a seat surface formed at one end of a cylindrical valve seat member, and an urging means for urging the valve body against the seat surface to close the valve. An injection valve in which the valve element is separated from the seat surface by a pressure of the fluid supplied to the valve seat member and opens against the urging force of the urging means. A leaf spring having a support arm extending toward the front, an opening along the contour of the support arm, and an ejection hole for ejecting fluid, wherein a rubber-like elastic film for preventing leakage of fluid from the opening of the leaf spring is provided. An injection valve, comprising: 2. The leaf spring has a disk shape, and a support arm thereof is formed by a plurality of cuts extending from a central portion to an outer periphery. The rubber-like elastic film covers at least one surface of the leaf spring. The injection valve according to claim 1, wherein: 3. The apparatus according to claim 1, further comprising: a leaf spring holding member configured to adjust a biasing force of the supporting arm to the valve body by changing a position of the leaf spring with respect to a seat surface. Injection valve as described.