JP2001248523A - Inlet filter - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide an inexpensive inlet filter which is capable of trapping even if foil or needle shaped foreign matter is contained in fuel. SOLUTION: In the inlet filter A pressed in an attaching part 221 of a fuel passage 22 of an inlet 2 of an injector provided with a conical surface 21 while mounting together with a stopper 3 having a lock surface 31, a plurality of tapered and nearly circular arc cross sectional first and second vertical grooves are alternately formed on one plate surface side from an upper end and a low end to a near side of the outer end, and a thin rectangular metallic plate wherein a nearly circular arc cross sectional horizontal groove for connecting the adjacent first and second vertical grooves to each other is spirally and tightly wound so as to set the one plate surface side to an inside.

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to an inlet filter mounted on a fuel passage of an inlet of an injector.

[0002]

2. Description of the Related Art Conventionally, an iron columnar member having a press-fit portion (large diameter) and a gap portion (small diameter) having different diameters is press-fitted into a cylindrical portion (fuel passage) of an inlet of an injector and passes through the gap. A bar filter for filtering foreign matter of the fuel is used (see FIG. 7).

[0003]

However, since the flow path is a gap, the filter cannot be trapped if the fuel contains foil-like or needle-like foreign matter. In addition, since it is necessary to control the size of the gap, there is a problem that the cylindrical surface of the cylindrical portion of the inlet needs to be machined with high accuracy, which increases the cost.

A first object of the present invention is to provide an inexpensive inlet filter which can trap even if foil-like or needle-like foreign matter is contained in fuel. Second embodiment of the present invention
It is an object of the present invention to provide a method of manufacturing an inlet filter which does not require high-precision machining of a fuel passage of an inlet of an injector to which the inlet filter is mounted. A third object of the present invention is to provide an injector that can be trapped by an inlet filter even if foil-like or needle-like foreign matter is contained in fuel.

[0005]

Means for Solving the Problems In the inlet filter, the first vertical groove and the second vertical groove having a tapered cross section and having a substantially circular arc shape are alternately formed in one plate from the upper end and the lower end to the vicinity of the other end. A thin rectangular metal plate having a plurality of lateral grooves having a substantially arc-shaped cross section formed on a plate surface side, and a plurality of lateral grooves having a substantially arc-shaped cross section connecting the adjacent first and second vertical grooves is formed on the plate surface side. It is wound in a spiral shape. When the inlet filter is rotated and pressed into the fuel passage of the inlet of the injector, the diameter is narrowed along the conical surface, and the metal plates adhere to each other, so that the passage formed by the first vertical groove, the horizontal groove, and the second vertical groove is formed. It is formed.

When a fuel pressure is applied to the fuel passage in which the inlet filter is mounted, the inner and outer cylindrical surfaces of the inlet filter receive pressure and are compressed in the radial direction, so that the metal plates further adhere to each other. Fuel enters through the first flute of the inlet filter, passes through the horizontal flute, and flows into the second flute.

[0007] When the fuel contains foreign matter in the form of foil or needles, the foreign matter is trapped when passing through the lateral groove. Since the first vertical groove and the second vertical groove are tapered and have a substantially arc-shaped cross section, the cross-sectional areas of the inlet side and the outlet side are large and the flow path resistance is small, so that the fuel can be efficiently filtered.

The stopper prevents the passage of fuel from the winding start end and the winding end by the locking surface, and also prevents the shape of the inlet filter from being deformed by the fuel pressure. This inlet filter can be mounted on the mounting portion of the fuel passage without performing high-precision processing.

[Claim 2] Fuel enters from the first vertical groove of the inlet filter, passes through the horizontal groove, and flows into the second vertical groove, but the pressure decreases as it goes closer to the inner part of the first vertical groove.
For this reason, the diameter of the lateral groove formed closer to the lower end on the fuel outlet side in a spirally dense state is increased in diameter to increase the filtration efficiency.

[Claim 3] By pressing a rectangular metal plate with a rolling roll having a convex portion, the horizontal groove and the first and second vertical grooves can be easily formed. In addition, all the grooves may be formed at once by one rolling roll, and the first and second vertical grooves are formed by the rolling rolls for forming the vertical grooves, and the horizontal grooves are formed by the rolling rolls for forming the horizontal grooves. Is also good.

[Claim 4] A lock for preventing fuel from passing from the winding start end and the winding end to the fuel passage of the inlet of the injector, wherein a conical surface having a passage diameter decreasing toward the downstream is formed on the inlet side. The inlet filter to be press-fitted and mounted together with the hollow cylindrical stopper having a surface can be easily manufactured at low cost through the following rolling process → rolling process → cutting process.

A rectangular metal plate is pressed by a rolling roll having a plurality of convex portions, and first and second vertical grooves having a substantially arc-shaped cross section reaching near the opposite end, and adjacent first vertical grooves having an inverted shape. , Second
A horizontal groove having a substantially arc-shaped cross section connecting the vertical grooves is formed on one plate surface side of the metal plate (rolling step). It has a spiral passage with a smaller radial diameter as it goes further, and a spiral shape is passed through a metal plate that has been thinned through a rolling process on the raceway surface of a rolling device in which a plurality of rollers are arranged on the raceway surface of the passage. (Rolling process). The spirally wound cylindrical body is cut into predetermined lengths (cutting step).

According to a fifth aspect of the present invention, a fuel passage from the start end and the end of the winding is prevented in the fuel passage of the inlet of the injector, in which the conical surface whose passage diameter becomes smaller toward the downstream side is formed on the inlet side. The inlet filter manufactured by the method for manufacturing an inlet filter according to claim 4 is press-fitted together with a hollow cylindrical stopper having a locking surface to be engaged.

An injector having the structure of claim 5 is
Even if foil-like or needle-like foreign matter is contained in the fuel, it can be trapped by the inlet filter. In addition, when drilling a hole in a mounting portion for mounting an inlet filter in a fuel passage, conventionally, honing was required for clearance management with a bar filter. Since honing is unnecessary, manufacturing costs can be reduced.

[0015]

DESCRIPTION OF THE PREFERRED EMBODIMENTS One embodiment of the present invention (Claims 1 to 5)
Will be described with reference to FIGS. The inlet filter A includes a first vertical groove 11, a second vertical groove 12, and a horizontal groove 13.
Is formed by spirally winding the metal plate 1 on which the metal plate 1 is formed (see FIGS. 1 and 2). The inlet filter A is mounted together with the hollow cylindrical stopper 3 on the mounting portion 221 of the inlet 2 of the injector B (FIGS. 3, 4, and 6).
reference).

The metal plate 1 is a rectangular thin plate having a length of 15 mm, a width of 94 mm and a thickness of 0.1 mm to 0.3 mm. An upper end 101 and a lower end 10 are provided on one plate surface 10 side of the metal plate 1.
From 2 to the vicinity of the other end, a plurality of tapered first vertical grooves 11 and second vertical grooves 12 having a semicircular cross section are formed alternately.
In addition, the cross-sectional shape of the first vertical groove 11 and the second vertical groove 12 may be an ellipse or an arc other than a semicircle.

The first vertical groove 11 and the second vertical groove 1
A lateral groove 13 having a semicircular cross section connecting the two has a plate surface 1 on one side.
A plurality is formed on the 0 side. The cross-sectional shape of the lateral groove 13 may be an ellipse, an arc, or a rectangle other than a semicircle. In this embodiment, the lateral groove 13 is formed such that the diameter increases as the position approaches the lower end 102 on the fuel outlet side.

Attachment 22 of fuel passage 22 of inlet 2
1 has an inner diameter of about 5 mm and a length of about 14 mm, and has a conical surface 21 formed on the inlet side, the diameter of which decreases toward the downstream side (see FIGS. 4 and 6).

The stopper 3 has an outer diameter of 5 mm and an axial length of 2.
It is made of 5 mm metal and manufactured by press molding.
As shown in FIG. 3, the stopper 3 has a locking surface 31 for preventing fuel from passing from the winding start end 14 and the winding end 15.

Next, the manufacturing process of the inlet filter A,
The mounting of the inlet filter A to the mounting portion 221 of the fuel passage 22 of the inlet 2 of the injector B will be described.

(1) A rectangular metal plate is pressed by one rolling roll (not shown) having a plurality of convex portions, and is pressed as shown in FIG.
As shown in the figure, the first vertical groove 1 having a semicircular cross section reaching the vicinity of the opposite end.
1, a second vertical groove 12 and an adjacent first vertical groove 11 having an inverse shape;
A horizontal groove 13 having a semicircular cross section for connecting the second vertical grooves 12 is formed on one plate surface 10 (rolling step).

(2) A rolling device 4 (see FIG. 5) having a helical passage 41 whose radial diameter decreases as going forward, and a plurality of rollers 421 to 428 arranged on a raceway surface 42 of the passage 41. Metal sheet 1 thinned through rolling process on track surface
Through the wire (rolling process). (3) The cylindrical body wound in a spiral shape is cut every 94 mm (cutting step).

(4) The stopper 3 is inserted all the way into the mounting portion 221 of the fuel passage 22 of the inlet 2 of the injector B. Next, the inlet filter A is pressed into the mounting portion 221 of the fuel passage 22 while rotating. As a result, the diameter is reduced along the conical surface 21, and the metal plates 1 are brought into close contact with each other, so that a passage formed by the first vertical groove 11, the horizontal groove 13, and the second vertical groove 12 is formed.

Next, the advantages of this embodiment will be described. [A] The conventional bar filter could not trap a foil-like or needle-like foreign matter. However, inlet filter A
Indicates that the fuel flow path is in the axial direction (first vertical groove 11) → radial direction (lateral groove 13) → axial direction (second vertical groove 12), and
The cross section of the lateral groove 13 at the portion for filtering the fuel is semicircular.
For this reason, when the fuel contains a foil-like or needle-like foreign matter, it can be trapped and removed.

[A] In the inlet filter A, as shown in FIG. 1, since the first vertical grooves 11 are spirally arranged, the flow path area can be increased. Further, since the first vertical groove 11 and the second vertical groove 12 are tapered and have a semicircular cross-section, the cross-sectional areas of the inlet side and the outlet side are wide and the flow resistance is small. For this reason,
The inlet filter A can efficiently filter the fuel.

[C] The inlet filter A can have a larger flow passage area by the first vertical grooves 11 arranged in a spiral shape, compared to the prior art in which a flow passage is formed in the gap at the outer peripheral portion of the bar filter.

[D] By the above [C], the total area of the lateral grooves can be increased, so that excellent filtration performance can be obtained even if the entire length of the inlet filter A is shorter than the conventional bar filter. By reducing the overall length of the inlet filter A, the degree of freedom in designing the peripheral portion of the inlet 2 can be increased.

[E] By changing the maximum length of the minimum cross section of the lateral groove in each groove, the size of the foreign matter that can be trapped can be changed.

[F] When drilling a hole in a mounting portion for mounting an inlet filter in a fuel passage, a honing process was conventionally required for clearance management with a bar filter. Is unnecessary, so that the manufacturing cost can be reduced.

[G] Since the inlet filter A and the stopper 3 are press-worked, they can be manufactured at a lower cost than a conventional inlet filter equipped with a bar filter requiring cutting.

[Brief description of the drawings]

FIG. 1 is a perspective view of an inlet filter according to one embodiment of the present invention.

FIG. 2 is an explanatory diagram showing a state where the inlet filter is developed.

FIG. 3 is an explanatory diagram of a stopper.

FIG. 4 is an explanatory view showing a state in which an inlet filter is attached to a mounting portion of a fuel passage of an inlet of an injector together with a stopper.

FIG. 5 is an explanatory view of a rolling device used in a roll process of spirally winding a metal plate through a raceway surface.

FIG. 6 is an explanatory view of an injector in which an inlet filter is mounted on a mounting portion of a fuel passage of the inlet.

FIG. 7 is an explanatory view of an injector according to the related art equipped with a bar filter.

[Explanation of symbols]

 DESCRIPTION OF SYMBOLS A Inlet filter B Injector 1 Metal plate 2 Inlet 3 Stopper 4 Rolling device 10 One plate surface 11 First longitudinal groove 12 Second longitudinal groove 13 Horizontal groove 14 Winding end 15 Winding end 21 Conical surface 22 Fuel passage 31 Locking surface 41 Passage 42 Track surface 101 Upper end 102 Lower end 421-428 Roller

Claims (5)

[Claims] 1. A hollow having a conical surface on the inlet side, the diameter of which decreases toward the downstream side, wherein the fuel passage of the inlet of the injector has a locking surface for preventing fuel from passing from the winding start end and the winding end. An inlet filter that is press-fitted and mounted together with a cylindrical stopper, and wherein, from an upper end and a lower end to a vicinity of the other end, a first vertical groove and a second vertical groove having a substantially arc-shaped cross section are alternately formed on one plate surface side. A thin rectangular metal plate formed by forming a plurality of lateral grooves having a substantially arc-shaped cross section connecting the adjacent first longitudinal groove and second longitudinal groove on the one plate surface side, wherein the one plate surface side is inside. Filter that is spirally wound as described above. 2. The inlet filter for an injector according to claim 1, wherein the diameter of the lateral groove formed closer to the lower end on the fuel outlet side in a spirally dense state is increased. 3. The rectangular groove is formed by pressing a rectangular metal plate with a rolling roll having a convex portion to form the horizontal groove and the first and second vertical grooves.
Injector inlet filter as described. 4. A hollow having a conical surface on the inlet side, in which the diameter of the passage decreases toward the downstream side, wherein the fuel passage of the inlet of the injector has an engaging surface for preventing fuel from passing from the winding start end and the winding end. What is claimed is: 1. A method for manufacturing an inlet filter, which is press-fitted and mounted together with a cylindrical stopper, comprising: pressing a rectangular metal plate with a rolling roll having a plurality of convex portions; , Second
A rolling step of forming, on one plate surface side, a vertical groove and an adjacent inverted first and second vertical grooves connecting the substantially vertical arc-shaped horizontal grooves; Having a spiral passage,
A rolling step of spirally passing a thin metal plate through the rolling step on the raceway surface of a rolling device in which a plurality of rollers are disposed on the raceway surface of the passage; and a spirally wound cylindrical body. A method for manufacturing an inlet filter, comprising: a cutting step of cutting at predetermined lengths. 5. A hollow having a conical surface on the inlet side in which the diameter of the passage decreases toward the downstream side, wherein the fuel passage of the inlet of the injector has a locking surface for preventing fuel from passing from the winding start end and the winding end. An injector which is press-fitted with an inlet filter manufactured by the method for manufacturing an inlet filter according to claim 4, together with a cylindrical stopper.