JPH09303233A - Accumulator fuel injection system - Google Patents

Abstract

PROBLEM TO BE SOLVED: To facilitate the working of a seat part of an accumulator vessel contacting with a clamping member as well as to lock the accumulator vessel and this fastening member both liquidtightly. SOLUTION: An accumulator vessel 11 and plate members 21 and 31 are formed separately from each other, and these plate members 21 and 31 are clamped tight to this accumulator vessel 11 by bolts 22 and 34. In addition, an accumulator chamber 11a accumulating fuel under pressure is formed in this accumulator vessel 11, and plural pieces of through holes interconnecting this accumulator chamber 11a and an external part of the accumulator vessel 11 are formed there. In this case a seat part, where each tip of a flow limiter 40 and a pressure limiter 51 contacts with, is formed in each through hole. The flow limiter 40 and the pressure limiter 51 are screwed tight to the plate members 31 and 21 screwed to the accumulator vessel 11, whereby the flow limiter 40 and the pressure limiter 51 are liquidtightly fastened to the accumulator vessel 11 tight enough.

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a pressure accumulating fuel injection device for accumulating high-pressure fuel supplied to an injector in a pressure accumulating chamber.

[0002]

2. Description of the Related Art An internal combustion engine (hereinafter referred to as an internal combustion engine) in which high-pressure fuel stored in a pressure accumulator is injected from a plurality of injectors
Fuel injectors (called "engines") are known.
This is to supply the high pressure fuel in the accumulator to a plurality of injectors provided corresponding to a plurality of cylinders of a multi-cylinder engine. The flow limiter that regulates the maximum flow rate of fuel, the pressure limiter that regulates the pressure of fuel, the connector having only the through hole, or the fuel pipe is directly connected to the pressure accumulator by screwing or the like. It is a structure.

For example, as shown in FIGS. 12 and 13, a pressure accumulation chamber 101 for accumulating fuel is formed in the axial direction of the pressure accumulation container 100, and the pressure accumulation chamber 101 and the pressure accumulation container 100 are formed.
A plurality of through holes 102 that communicate with the outside of the. A female screw portion 102a is formed on the inlet-side inner wall forming the through hole 102, and the pressure accumulating chamber 10 of the inner wall described above is formed.
A sheet portion 103 is formed on the first side. Female thread part 1
02a has a male threaded portion such as a flow limiter, a pressure limiter, a fuel pipe, etc., screw-coupled thereto, and a tip portion of the seat portion 103.
Abut.

[0004]

Some fuel pressures in the pressure accumulating chamber 101 reach 100 to 150 MPa,
Fastening members such as a flow limiter and a pressure limiter need to be liquid-tightly fixed to the seat portion 103. Further, in order to maintain the sealing property, it is necessary to align the seat portion 103 and the female screw portion 102a with high accuracy. However, in the structure of the conventional pressure accumulator as shown in FIG. 12 and FIG. 13, since the seat portion 103 is formed at the bottom of the through hole 102 including the female screw portion 102 side on the accumulator chamber 101 side, the accumulator container of the through hole 102 is formed. From the outer opening to the seat 10
3 are apart. Therefore, it is difficult to machine the conical surface of the seat portion 103 with high accuracy, and it is also difficult to align the seat portion 103 and the female screw portion 102a with high accuracy. Further, when the screw diameter of the fastening member is changed due to a change in the specifications of the fastening member such as the pressure limiter or the flow limiter, the through hole 10 formed in the pressure accumulating container 100.
Since it is difficult to change the screw diameter of 2
00 must be replaced according to the screw diameter of the fastening member.

The present invention has been made to solve such a problem, and facilitates processing of a sheet portion of a pressure accumulator container that abuts a fastening member, and a pressure accumulator that fixes the pressure accumulator container and the fastening member in a liquid-tight manner. An object of the present invention is to provide a fuel injection system. Another object of the present invention is to provide a pressure accumulating fuel injection device in which the fastening member can be easily attached to the pressure accumulating container by changing the plate member or the ring member even if the screw diameter changes due to the specification change of the fastening member. Especially.

[0006]

According to the pressure-accumulation type fuel injection device of the first aspect of the present invention, the plate member that is screwed to the fastening member and the pressure accumulation container that forms the seat portion are separately formed. Since the opening portion of the through hole on the outside of the pressure accumulating container and the seat portion are close to each other, it is possible to easily perform the processing of the seat portion that requires highly accurate processing. The manufacturing cost can be reduced by facilitating the processing.
Further, when a screw connection failure between the fastening member and the plate member or a seal failure between the plate member and the pressure accumulating container occurs, it is possible to deal with these defects by replacing the plate member without replacing the pressure accumulating container. it can. Further, even if the screw diameter of the fastening member changes due to a change in the specifications of the fastening member or the like, by changing the plate member according to the screw diameter of the fastening member, it is possible to cope with the specification change without replacing the pressure accumulating container. Therefore, the cost of replacement parts can be reduced.

Further, since the fastening member is screwed to the plate-shaped plate member, the plate member is less likely to be deformed eccentrically. Therefore, the sealing property between the fastening member and the pressure accumulator is improved. According to the pressure-accumulation fuel injection device of the second aspect of the present invention, the plate member can be firmly fixed to the pressure-accumulation container, so that the sealing property between the fastening member and the pressure-accumulation container can be improved.

According to the pressure-accumulation fuel injection device of the third aspect of the present invention, the ring member that is screwed to the fastening member and the pressure-accumulation container that forms the seat portion are separately formed, so that the pressure-accumulation container having the through hole is formed. Since the outer opening portion and the seat portion are close to each other, it is possible to easily perform the processing of the seat portion, which requires highly accurate processing. The manufacturing cost can be reduced by facilitating the processing. Further, when a screw connection failure between the fastening member and the ring member or a seal failure between the ring member and the pressure accumulating container occurs, it is possible to deal with these defects by replacing the ring member without replacing the pressure accumulating container. it can. Further, even if the screw diameter of the fastening member changes due to a change in the specifications of the fastening member or the like, by changing the ring member according to the screw diameter of the fastening member, it is possible to cope with the change in the specifications without replacing the pressure accumulating container. Therefore, the cost of replacement parts can be reduced.

Further, since the fastening member is screwed to the annular ring member, the ring member is less likely to be deformed eccentrically. Therefore, the sealing property between the fastening member and the pressure accumulator and the ring member and the pressure accumulator is improved. According to the pressure-accumulation type fuel injection device of claim 4 of the present invention, various members such as a flow rate adjusting member, a fluid pressure adjusting member, a member having only a through hole or a pipe or the like, which is liquid-tightly attached to the pressure accumulating container, are stored in the accumulating container. It can be installed tightly and easily.

[0010]

Embodiments of the present invention will be described below with reference to the drawings. (First Embodiment) FIG. 8 shows a system configuration diagram of a pressure accumulation type fuel injection device according to a first embodiment of the present invention. Pressure accumulator 10
Is composed of a pressure accumulator 11 and plate members 21 and 31. Three plate members 21 are screwed to the lower side of the pressure accumulating container 11 in FIG.
Six plate members 31 are screwed to the upper part of the. A pressure limiter 51 as a fluid pressure adjusting member is screwed to the leftmost side of the plate member 21 in FIG. 8, and a pipe connecting portion (not shown) is screwed to the other two plate members 21. A flow limiter 40 as a flow rate adjusting member is screwed to the plate member 31. Further, a pressure sensor 50 is fixed to one axial end of the pressure accumulating container 11 and the fuel pressure in the pressure accumulating chamber 11a is controlled by an engine control device (not shown below).
U ”) as a pressure signal.

The high-pressure fuel pressurized by the high-pressure fuel supply pump 60 is supplied to the pressure accumulating chamber 11a through the supply pipe 61 and a pipe connecting portion (not shown) and is accumulated at a predetermined pressure. Accumulation chamber 11a
The high-pressure fuel accumulated at a predetermined pressure in the above is supplied from the supply pipe 62 to the injector 70 arranged in each cylinder of the engine. The fuel pressure in the pressure accumulating chamber 11a is the pressure limiter 51.
When the fuel pressure in the pressure accumulating chamber 11a exceeds a predetermined pressure, excess fuel is returned from the pressure limiter 51 to the fuel tank or the like.

Next, the structure of the pressure accumulator 10 will be described in detail. The pressure accumulator 11 and the plate members 21 and 31 of the pressure accumulator 10 shown in FIGS. 1, 2 and 3 are formed separately, and the plate members 21 and 31 are formed by the bolt 2
It is fixed to the pressure accumulating container 11 by 2 and 34. As shown in FIG. 4 and FIG.
a, through holes 12 and 13 are formed. The through holes 12 and 13 communicate the pressure accumulating chamber 11 a with the outside of the pressure accumulating container 11. The seat portions 12a and 13a are the accumulator container 1
An inner wall forming through holes 12 and 13 following the outer wall of 1,
That is, the through holes 12 and 13 are formed in the vicinity of the opening on the outside of the accumulator container. The seat portion 12a is a portion with which the tips of the six flow limiters 40 corresponding to the number of engine cylinders are in contact, and the seat portion 13a is a portion with which the tips of the pressure limiters 51 and the pipe connecting portions are in contact. Two screw holes 14 are formed on both sides of the through holes 12 and 13 in the radial direction so as to form a predetermined angle with respect to the axial direction of the pressure accumulating container 11.

Since the plate members 21 and 31 have almost the same structure, the description of the plate member 31 also serves as the description of the plate member 21. As shown in FIGS. 6 and 7, the plate member 31 is formed in a rhombus shape in which the vertices are processed into an R shape in a plan view, and has a screw hole 32 in the center and two screw holes 32 on both sides in the radial direction. A through hole 33 is formed. A female screw portion 32 a is formed on the inner wall of the plate member 31 forming the screw hole 32.

Next, the procedure for assembling the pressure accumulator 10 and the flow limiter 40 will be described. Through hole 12 of accumulator 11
The screw hole 14 and the screw hole 32 and the through hole 33 of the plate member 31 are aligned with each other, and the bolt 34 is attached to the through hole 3
3, and the tip of the bolt 34 is screwed with a nut. After the plate member 31 is screwed to the pressure accumulating container 11, the flow limiter 40 is screwed to the female screw portion 32a of the plate member 31 and the tip of the flow limiter 40 is liquid-tightly fastened to the seat portion 12a. This flow limiter 4
It is also effective to temporarily fix the bolt 34 and the nut in order to facilitate the liquid-tight fastening of the seat 0 and the seat portion 12a.

The liquid tight connection between the flow limiter 40 and the pressure accumulator 11 has been described above, but the pressure limiter 51 has been described.
Also, since the fastening structure and the assembling procedure of the pipe connecting portion and the pressure accumulator 11 are almost the same as those of the flow limiter 40, the description thereof is omitted. In the above-described first embodiment of the present invention, the positions of the through holes 12 and 13 formed in the circumferential direction and the axial direction of the pressure accumulating container 11 are set in the plate member 2 in the pressure accumulating container 11.
It is possible to form 1 and 31 at any position as long as they can be fixed.

In the first embodiment, the plate members 21 and 31 are screwed to the pressure accumulating container 11 with bolts. However, a guide rail is provided on the outer wall of the pressure accumulating container, and the guide rail restricts the rotation of the plate member. It is also possible to lock the plate-shaped plate member so as not to separate from the pressure accumulating container, align the plate-shaped plate member with the through hole along the guide rail, and screw the fastening member and the plate member together. is there.

(Second Embodiment) A second embodiment of the present invention is shown in FIGS. 9, 10 and 11. The pressure accumulator 81 of the pressure accumulator 80 is formed in a cylindrical shape, and three ring members 82 and 83 are fitted into the pressure accumulator 81.
A flat surface 81a is formed on the upper side of the pressure accumulating container 81 in FIG. 9, and the flat member 81a engages with a flat portion (not shown) formed on the inner peripheral walls of the ring members 82 and 83. Positioning of 83 and 83 in the rotational direction can be facilitated.

The flow limiter 40 is screwed to the ring member 82, and the tip portion of the flow limiter 40 is in contact with the seat portion (not shown) of the pressure accumulating container 81. Ring member 82
There is only one threaded hole formed in the threaded hole to be threadedly connected to the flow limiter 40. The ring member 83 has two screw holes formed on both sides in the radial direction. The flow limiter 40 is screwed into one of the screw holes, and the pressure limiter 51 or the pipe connecting portion is screwed into the other screw hole of the ring member 83.

In the second embodiment, ring members 82 and 8
3 is fitted in the pressure accumulating container 81, and the flow limiter 40 and the pressure limiter 51 are screwed to the ring members 82 and 83. It can be fixed to the accumulator 81. Also, instead of using the ring member 83, the ring member 82
It is also possible to make it possible to fasten the two fastening members to be fastened by the ring member 83 at different positions by using two.

In the second embodiment of the present invention described above, the circumferential and axial positions of the through hole formed in the pressure accumulator 81 should be formed at any position as long as the ring member can be fixed to the accumulator. Is also possible. It is also possible to change the position of the screw hole formed in the ring member according to the through hole formed in the pressure accumulating container. According to each of the above-described embodiments of the present invention described above, the pressure accumulating container having the seat portion that contacts the flow limiter or the pressure limiter as the fastening member, and the plate member or the ring member that is screwed to the fastening member are different from the pressure accumulating container. Since the sheet portion is formed in the vicinity of the outer wall of the pressure accumulating container by forming the body portion, the sheet portion can be easily processed with high accuracy. Also, even if the screw diameter of the fastening member is changed due to changes in the specifications of the fastening member, etc., the plate member or ring member can be changed according to this screw diameter to easily fasten the pressure accumulating container without replacing the accumulating container. The member can be fixed. Therefore, the manufacturing cost of the pressure accumulator and the replacement cost of parts due to the specification change are reduced.

[Brief description of drawings]

FIG. 1 is a front view showing a pressure accumulator according to a first embodiment of the present invention.

FIG. 2 is a view in the direction of arrow II in FIG. 1;

FIG. 3 is a view on arrow III in FIG.

FIG. 4 is a partial cross-sectional view showing a pressure accumulator according to the first embodiment.

FIG. 5 is a view in the direction of arrow V in FIG. 4;

FIG. 6 is a plan view showing a plate member of the first embodiment.

7 is a sectional view taken along line VII-VII of FIG.

FIG. 8 is a system configuration diagram showing a pressure accumulation type fuel injection device of a first embodiment.

FIG. 9 is a front view showing a pressure accumulator according to a second embodiment of the present invention.

FIG. 10 is a view in the direction of the arrow X in FIG. 9;

FIG. 11 is a view on arrow XI in FIG. 9.

FIG. 12 is a sectional view showing a conventional pressure accumulator.

FIG. 13 is an enlarged cross-sectional view around a seat portion formed in a conventional pressure accumulator.

[Explanation of symbols]

10 Pressure Accumulator 11 Pressure Accumulator Container 11a Accumulator Chamber 12, 13 Through Hole 12a, 13a Seat Part 14 Screw Hole 21, 31 Plate Member 40 Flow Limiter (Flow Rate Adjusting Member) 51 Pressure Limiter (Fluid Pressure Adjusting Member) 60 High Pressure Fuel Supply Pump 61 , 62 supply pipe 70 injector 80 pressure accumulator 81 pressure accumulator 82, 83 ring member

Claims (4)

[Claims] 1. A pressure accumulating container for supplying fuel, which has accumulated pressure in a pressure accumulating chamber, to an injector, having a through hole for communicating the pressure accumulating chamber and the outside of the accumulator, and a sheet accumulating portion formed in the through hole. A container, a plate member having a screw hole provided with a female screw portion, and a plate member that is locked to the pressure accumulating container, and abuts against the sheet portion by screwing the female screw portion, and is liquid-tightly fixed to the pressure accumulating container. An accumulator type fuel injection device, comprising: 2. The pressure-accumulation fuel injection device according to claim 1, wherein the plate member is screwed to the pressure-accumulation container. 3. A pressure accumulator for supplying fuel, which has accumulated pressure in a pressure accumulator, to an injector, the accumulator having a through hole for communicating the accumulator with the outside of the accumulator, and a seat portion formed in the through hole. A container, a threaded hole provided with an internal thread portion, and a ring member to be fitted and inserted into the pressure accumulating container, and abutting against the seat portion by screwing with the internal thread portion, and fixed to the accumulator container in a liquid-tight manner. An accumulator type fuel injection device, comprising: 4. The pressure accumulator according to claim 1, 2 or 3, wherein the fastening member is one of a flow rate adjusting member, a fluid pressure adjusting member, a member having only a through hole, or a pipe. Fuel injection device.