JPH0429079Y2 - - Google Patents

Description

[Detailed Description of the Invention] [Industrial Application Field] The present invention relates to a fuel injection valve used in internal combustion engines and the like.

[Prior Art] As a conventional fuel injection valve of this type, one shown in FIG. 3 is known.

A valve body 5 having a fuel injection nozzle 3 at its tip is partially housed and fixed in one end of a housing 1, and the nozzle 3 is opened and closed by a valve needle body 9 driven by excitation and demagnetization of an electromagnetic coil 7. death,
It controls the amount of fuel injection.

A connector 11 having a cylindrical portion 11A inserted into the electromagnetic coil 7, a flange 11B, and a through hole 11C in the center is fixed to the other end of the housing 1 by the flange 11B. .

Furthermore, an anchor member 9A made of a magnetic material is fixed to the terminal end of the valve needle body 9.

Reference numeral 13 denotes a spring that presses the valve needle body 9, and an initial load is applied to this spring 13 by a pressing force adjustment pipe 15 that is caulked and fixed within the through hole 11C of the connector 11.

When the electromagnetic coil 7 is excited, the valve needle body 9 is attracted together with the anchor member 9A, the nozzle 3 of the valve body 5 is opened, and fuel pressurized to a predetermined pressure is injected from the nozzle 3. When the electromagnetic coil is demagnetized, the valve needle body 9 is seated on the valve seat by the force of the spring 13, closing the injection port 3 and stopping the injection.

[Problems to be solved by the invention] By the way, such fuel injection valves have to be manufactured under strict standards in order to accommodate the wide range of fuel injection amount requirements from the idling state to the maximum output state of the internal combustion engine to which they are installed. Therefore, appropriate flow rate adjustment management is required.

Therefore, conventionally, in order to manage the maximum flow rate,
The static flow characteristics of the valve body 5, which has been drilled and machined, are checked, and the dynamic flow characteristics are checked by sending a predetermined number of drive pulses to check the flow rate after the fuel injection valve is assembled.

However, in the conventional fuel injection valve structure, although the valve body 5 alone passes the static flow rate check, when assembled as a fuel injection valve, due to pressure changes in the fuel passage due to the assembly,
There are some cases where the dynamic flow characteristics do not meet the predetermined requirements. Since there is no way to adjust such valves, the entire fuel injection valve has to be discarded as a defective product, resulting in poor production yields and high manufacturing costs.

Further, even if the predetermined requirements are met, there is a problem in that a certain width has to be provided, so some variation in the product has to be tolerated.

An object of the present invention is to solve the problems of the conventional fuel injection valve, and to provide a fuel injection valve that is easy to manufacture, has a high yield, and can ensure a certain level of quality in terms of performance.

[Means for Solving the Problems] In order to achieve the above object, the fuel injection valve of the present invention includes a housing, a valve body partially housed in the housing and having a nozzle at its tip;
a valve needle body that opens and closes the nozzle; an electromagnetic means that excites and drives the valve needle body; a connector whose flange is fixed to the housing and has a through hole in the center; In a fuel injection valve, the pressure adjustment pipe is provided with a passageway in the valve needle and a pressure adjustment pipe that applies an initial load to a spring that presses the valve needle, and the pressure adjustment pipe is centered at its axis at least when inspecting the flow rate characteristics. The pipe for adjusting the pressing force is provided with a rotation operation part for rotating the pipe for adjusting the pressing force, and the side wall of the connector and the side wall of the pipe for adjusting the pressing force are each provided with a turning operation part for rotating the pressing force adjusting pipe. A hole is provided in which the area of the flow path can be changed by a combination of the two according to the rotation of the pressing force adjustment pipe.

[Operation] According to the present invention, a valve body in which a valve needle body is attached to a housing, an electromagnetic means, and a connector in which a spring and a pressure adjustment pipe are attached in a through hole are incorporated, and then static flow rate characteristics are determined. and check the dynamic flow characteristics.

As a result of checking the flow rate characteristics, even if the predetermined requirements are not met, the flow area obtained by the combination of holes provided in the side wall of the connector and the side wall of the pressure adjustment pipe is used for pressure adjustment. The desired flow rate can be adjusted by rotating the pipe.

Therefore, as long as there are no significant manufacturing errors, the flow rate characteristics can be adjusted, making it possible to obtain fuel injection valves with excellent yield and stable quality.

[Example] Hereinafter, an example of the present invention will be described based on the accompanying drawings.

FIG. 1 is a sectional view showing an embodiment of the present invention.

In the figure, 21 is a housing, which includes a valve body accommodating portion 21A and an electromagnetic coil accommodating portion 21A.
It has B. 23 is a valve body, which has a fuel injection nozzle 23A at its tip and a nozzle 23 at the center.
A valve seat 23C is provided on the inner side of the through hole 23B connected to A and the nozzle 23A. 25 is guided to the through hole 23B of the valve body 23 and is connected to the nozzle 23.
A is a valve needle body that opens and closes, and a needle portion 25A projects with a space between it and the nozzle 23A.
and the shoulder portion 2 that comes into contact with the valve seat 23C.
5B, a guide cutout 25C, and a stroke regulating flange 25D, and an anchor member 25E made of a magnetic material is fixed to the terminal end. In addition,
23D is a protector for protecting the protruding needle portion 25A.

Reference numeral 27 denotes a C-shaped stopper against which the stroke regulating flange 25D of the valve needle body 25 comes into contact.

After the valve body 23 with the stopper 27 and the valve needle body 25 attached thereto is partially inserted into the valve body accommodating portion 21A of the housing 21, the end portion 21C of the housing 21 is bent and fixed.

29 is an O-ring for sealing.

31 is a bobbin around which a coil 33 is wound;
It has a fuel passage groove 31A in the inner circumference.

35 is a cylindrical portion 3 located inside the bobbin 31
5A, a flange 35B, and a through hole 35C in the center, and the end 21D of the housing 21 is bent and fixed by the flange 35B. A hole 35D is bored in the side wall of the cylindrical portion 35A of the connector 35, as shown clearly in FIG.

37 is the anchor member 25 of the valve needle body 25
This is a spring that contacts and presses E.

39 is installed in the through hole 35C and the spring 3
It is a pipe for adjusting the pressing force to apply an initial load to 7, and has a passage 39A in the center, an axially long hole 39B in the side wall as shown in FIG. 2, and a driver etc. at the end. It has an engaging groove 39C that can be fitted. Note that 39D is a filament for ensuring secure caulking fixation with the connector 35. Furthermore, 4
Reference numeral 1 is a socket for connecting wiring for supplying power to the coil 33, reference numeral 43 is a fuel hose, and reference numerals 45 and 47 are O-rings for sealing.

In the fuel injection valve having the above structure, the fuel passage is formed as follows.

That is, the fuel supplied from the fuel hose 43 under a predetermined pressure flows from the passage 39A of the pressure adjustment pipe 39 to the hole 39B, the hole 35D of the side wall of the connector 35, the fuel passage groove 31A of the bobbin 31, and the anchor member 25. It passes between the housing 21 and between the valve needle body 25 and the valve body 23 and reaches the nozzle port 23A.

By the way, immediately after being assembled as a fuel injection valve in this way, the pressing force adjustment pipe 39 is in a state where it can move freely.

Therefore, as described above, the static flow characteristics are checked and the dynamic flow characteristics are checked.

When adjusting the static flow rate characteristics, move the pressing force adjusting pipe 39 in its axial direction and setting the initial load of the spring 37. When adjusting the dynamic flow rate characteristics, move the pressing force adjusting pipe 39.
9 is rotated using the engagement groove 39C to change the opening area due to the overlap between the hole 39B and the hole 35D.

In this way, even at a position where both characteristics satisfy predetermined values, the neck portion 35E of the connector 35 is crimped to fix the pressing force adjustment pipe and the adjustment is completed.

In this embodiment, a type of fuel injection valve in which a valve seat exists on the inner side of the injection port has been described, but this can also be applied to other types of fuel injection valves, such as those equipped with a mushroom-shaped needle valve. Needless to say, it is applicable.

[Effects of the invention] As explained above, the fuel injection valve of the invention has the following advantages:
This is because the flow path area is changed by rotating the pressure adjustment pipe and shifting the positional relationship between the hole provided on the pressure adjustment pipe side and the hole provided on the connector side. The static and dynamic flow characteristics of the fuel injection valve can be adjusted while the fuel injection valve is assembled, and fuel injection valves of constant and stable quality can be easily manufactured with high yield.

[Brief explanation of the drawing]

Fig. 1 is a sectional view showing one embodiment of the present invention;
The figure is a perspective view showing the relationship between the connector and the pressure adjustment pipe, and FIG. 3 is a sectional view showing a conventional fuel injection valve. 21...housing, 23...valve body,
23A... Nozzle, 25... Valve needle body, 3
3... Coil, 35... Connector, 35B... Flange, 35C... Through hole, 35D... Hole, 37...
Spring, 39...pipe for adjusting pressure force, 39
A...Aisle, 39B...hole.

Claims (1)

[Claims for Utility Model Registration] A housing, a valve body that is partially housed in the housing and has a nozzle at its tip, a valve needle body that opens and closes the nozzle, and electromagnetic means that excites and drives the valve needle body. , a connector whose flange is fixed to the housing and has a through hole in the center; and a connector installed in the through hole and having a passage in the center for adjusting the pressing force to apply an initial load to a spring that presses the valve needle. In the fuel injection valve equipped with a pipe, the pushing force adjustment pipe is rotatable around its axis at least when inspecting flow rate characteristics, and the pushing force adjusting pipe is rotated around the pushing force adjusting pipe. A rotation operation section is provided on each of the side wall of the connector and the side wall of the pressure adjustment pipe, and the flow path area is changed by a combination of the two according to the rotation of the pressure adjustment pipe. A fuel injection valve characterized by being provided with a hole that can be used.