JP2006022703A - Throttle body in fuel injection device - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To completely remove working burr in a penetrating part in a downstream side of a fuel injection passage concurrently with processing of the fuel injection passage and to suppress air turbulence. <P>SOLUTION: Fuel injected from a fuel injection valve J is injected and supplied to inside of an intake passage 11 via the fuel injection passage 2. From a downstream side of a throttle body 10 toward the upstream side, a relief recessed part 1 is provided so as to be recessed. At a tip of the relief recessed part 1, a spherical part 1a is formed. A downstream part 2a of the fuel injection passage 2 penetrates through the spherical part 1a of the relief recessed part 1 and is opened, and a penetration angle A in the penetrating part K of the fuel injection passage 2 is formed to be an obtuse angle around the circumference. <P>COPYRIGHT: (C)2006,JPO&NCIPI

Description

  The present invention relates to a fuel injection device in which the fuel in a fuel tank is boosted by a fuel pump, and the boosted fuel is supplied to the intake passage of a throttle body via the fuel injection valve, and of these, the fuel injection valve is particularly mounted Related to the throttle body.

A first example of a conventional throttle body is disclosed in FIGS.
Reference numeral 10 denotes a throttle body having an intake passage 11 penetrating therethrough laterally. The opening area of the intake passage 11 is controlled to be opened and closed by a throttle valve 13 attached to a throttle valve shaft 12.
J is a fuel injection valve that injects fuel toward the intake passage 11, and its front end portion J 1 is inserted and supported in the throttle body 10, and its rear end portion J 2 is inserted and supported in the fuel distribution pipe 14. It is held between the throttle body 10 and the fuel distribution pipe 14.
In the above, the following holes and passages are formed in the throttle body 10 that supports the tip J1 of the fuel injection valve J.
That is, the seal hole 15 is drilled from the lower end surface 10a of the throttle body 10 obliquely upward to the left. Further, a relief recess 16 is formed from the downstream side of the throttle body 10 (the left end 10b side of the throttle body 10) to the upstream side (the right end 10c side of the throttle body 10). 11 and open.
A fuel injection passage 17 having a diameter smaller than that of the seal hole 15 is formed through the seal hole 15 toward the escape recess 16.
Here, in the above description, the longitudinal axis of the seal hole 15 and the fuel injection passage 17 are arranged concentrically on the same axis XX, and the tip of the escape recess 16 (right end in the figure) A flat portion 16a orthogonal to the axial center line XX is formed.
That is, the tip of the fuel injection passage 17 opens perpendicularly toward the flat portion 16 a of the escape recess 16.
According to the above, the tip end portion J1 of the fuel injection valve J is inserted and arranged slightly projecting from the seal hole 15 into the fuel injection passage 17, and the elastic seal member 18 placed in the seal hole 15 is arranged on the outer periphery of the tip portion J1. Accordingly, the fuel injection passage 17 and the atmosphere are kept airtight, and air is not sucked into the intake passage 11 from the fuel injection passage 17.

A second example of a conventional throttle body will be described with reference to FIG.
In addition, about the same structure part as FIG. 4, the description is abbreviate | omitted using the same code | symbol.
Reference numeral 19 denotes a fuel injection passage having a diameter smaller than that of the seal hole 15, and is formed directly into the intake passage 11 from the seal hole 15.
According to the above, the front end portion J1 of the fuel injection valve J is inserted and disposed so as to protrude from the seal hole 15 into the fuel injection passage 19, and the elastic seal member 18 disposed in the seal hole 15 is disposed on the outer periphery of the front end portion J1. Thus, the fuel injection passage 17 and the atmosphere are kept airtight.

According to the first conventional example, fuel whose pressure is increased from the fuel distribution pipe 14 into the fuel injection valve J is supplied to the fuel injection passage 17 from the nozzle hole at the tip J1 of the fuel injection valve J. Further, this fuel is supplied to the intake passage 11 through the escape recess 16.
In the first example, the relief recess 16, the seal hole 15, and the fuel injection passage 17 are formed by casting when the throttle body is molded.
That is, the relief recess 16 is formed by casting with a first core drawn leftward in the drawing, and the fuel injection passage 17 including the seal hole 15 is formed by casting with a second core drawn rightward. A thin cast film is formed between the flat portion 16a of the escape recess 16 and the tip of the fuel injection passage 17 by disposing the tip of the first core and the tip of the second core facing each other. .
When the throttle body 10 is processed, the cast film is removed by being penetrated from the fuel injection passage 17 side with a drill substantially the same as the diameter of the fuel injection passage 17.
Here, at the time of passage machining, a machining burr is generated at a part through which the drill penetrates (referred to as a penetration portion K). This machining burr is more easily peeled off as the drill penetration angle becomes obtuse and becomes an acute angle. It is known that it remains in the penetrating part.
According to the first example, since the fuel injection passage 17 is disposed through the flat portion 16a orthogonal to the fuel injection passage 17, a through angle A of 90 degrees is formed over the entire circumference of the through portion K. The
According to this, the processing burr generated in the penetrating part K is peeled off or remains, and it takes a lot of time for the inspection and reworking, and it is difficult to improve the production efficiency.
Furthermore, since the relief recess 16 has a large volume from the flat portion 16a toward the left end 10b and its shape changes abruptly from the intake passage 11 toward the escape recess 16, a turbulent flow is likely to occur in the air flow. Reduces inhalation efficiency. This defective portion is indicated by a cross line in FIG.

  Here, as shown in FIG. 6, it is considered that the angle of the flat portion 16a is changed to a dotted line or a one-dot chain line. Aa is formed and the problem is still not solved.

Further, according to the second example, since the fuel injection passage 19 is directly communicated with the intake passage 11 without passing through the escape recess, a reduction in suction efficiency can be suppressed.
However, since one penetration angle Aa of the penetration part K to the intake passage 11 of the fuel injection passage 19 is formed at an acute angle, the improvement in production efficiency is still not solved.

  The throttle body in the fuel injection device according to the present invention is made in view of the above problems, and supplies fuel injected from the fuel injection valve to the intake passage through the fuel injection passage. The purpose is to prevent the production burr from occurring and to improve the production efficiency and to suppress the reduction of the intake efficiency.

In order to achieve the above object, the fuel injection device according to the present invention has a fuel injection valve mounted on a throttle body that has an intake passage extending through the inside thereof. In the throttle body supplied into the intake passage through the fuel injection passage,
The first is that a spherical portion is formed at the tip from the downstream side to the upstream side of the throttle body, a relief recess facing the intake passage is provided, and the downstream of the fuel injection passage is opened toward the spherical portion of the relief recess. It is characterized by.

  According to the second aspect of the present invention, in addition to the first feature, the center R of the spherical surface portion of the escape recess is provided within the extension line of the diameter of the fuel injection passage and within the diameter of the intake passage. It is characterized by.

According to the first feature of the present invention, the fuel injected from the fuel injection valve is injected from the fuel injection passage into the escape recess through the spherical portion and supplied into the intake passage.
The cast film formed at the downstream end of the fuel injection passage is removed by inserting a drill from the fuel injection passage into the escape recess. At this time, the fuel injection passage is opened toward the spherical surface of the escape recess. Therefore, the penetrating angle in the penetrating portion of the fuel injection passage can be formed as an obtuse angle over the entire circumference, and thereby processing burrs generated in the penetrating portion can be effectively removed, thereby improving the production efficiency.
Further, since the tip side of the escape recess is formed into a spherical surface, the volume corresponding to the spherical surface can be reduced as compared with the tip side forming a flat portion, and the shape from the intake passage toward the escape recess can be changed gently. As a result, the generation of turbulence in the air flow can be suppressed, and the reduction in suction efficiency can be suppressed.

  Further, according to the second feature of the present invention, the center of the spherical portion of the escape recess is located within the extension line of the diameter of the fuel injection passage and within the diameter of the intake passage. It can be opened toward the center of the part, so that the penetration angle in the penetration part of the fuel injection passage can be formed uniformly and obtusely, and the processing burr generated in the penetration part can be removed more reliably. it can.

An embodiment of a throttle body in a fuel injection device according to the present invention will be described below with reference to FIGS.
FIG. 1 is a longitudinal sectional view of a throttle body.
FIG. 2 is a left side view of FIG.
It is.
In addition, the same structure part as FIG. 4 uses the same code | symbol, and abbreviate | omits description.
Reference numeral 1 denotes a relief recess that is recessed from the downstream side (left end 10b) of the throttle body 10 toward the upstream side (right end 10c), and a spherical surface portion 1a is formed at the tip thereof.
The relief recess opens toward the intake passage 11 and the left end 10b of the throttle body 10.
The fuel injection passage 2 is formed concentrically with the seal hole 15, and the downstream 2 a of the fuel injection passage 2 is opened toward the spherical portion 1 a of the escape recess 1.
Here, the fuel injection passage 2 including the escape recess and the seal hole 15 is formed at the same time as the injection of the throttle body 10. At this time, the spherical portion 1 a of the escape recess 1 and the downstream of the fuel injection passage 2 are formed. Since the cores 2a and 2a are opposed to each other, a cast film is formed at the facing portion as in the conventional example.
The cast film formed in the facing portion is inserted into the fuel injection passage 2 with a drill having a diameter substantially the same as the diameter of the fuel injection passage 2 through the seal hole 15 and penetrated into the escape recess 1. Thus, the cast film is processed and removed, and the downstream 2a of the fuel injection passage 2 can be arranged to penetrate toward the escape recess 1.

According to the structure of the fuel injection passage, the downstream 2a of the fuel injection passage 2 penetrates toward the spherical portion 1a of the escape recess 1 so that the penetration angle A of the penetration portion K with respect to the escape recess 1 of the fuel injection passage 2 is injected into the fuel. An obtuse angle can be formed over the entire circumference of the passage 2.
This is understood by the enlarged view of FIG.
According to the above, first, since there is no portion where the penetration angle A of the penetration portion K with respect to the relief recess 1 of the fuel injection passage 2 is formed at an acute angle over the entire circumference, the fuel injection passage 2 is penetrated with a drill. Then, when the cast film is processed and removed, all burrs can be removed during drilling without generating burrs in the penetrating portion K.
Therefore, the production efficiency can be greatly improved and the quality can be stabilized.

  Also, according to the fact that the tip shape of the relief recess 1 is the spherical surface portion 1a, the volume of the relief recess 1 is reduced as shown by the crossing line shown in FIG. Since the shape can be smoothly changed from the intake passage 11 toward the escape recess 1, the turbulent flow of air flowing into the escape recess 1 from the intake passage 11 can be suppressed, There is no reduction in the efficiency of air intake toward the engine.

  Furthermore, according to the fact that the center R of the spherical portion 1a of the escape recess 1 is provided within the extension line of the diameter of the fuel injection passage 2 and within the diameter D of the intake passage 10, the fuel injection passage 2 is formed into the spherical portion. Since it can open toward the center of 1a, the penetration angle A of the penetration part K of the fuel injection passage 2 can be formed to a uniform obtuse angle over the entire circumference, and the occurrence of machining burrs can be suppressed even more uniformly during drilling. it can.

The longitudinal cross-sectional view which shows one Example of the throttle body in the fuel-injection apparatus of this invention. The left view of FIG. The expanded sectional view of the penetration part of the fuel-injection channel | path of FIG. The longitudinal cross-sectional view of the conventional throttle body. The left view of FIG. The simplified expanded sectional view of the penetration part of the fuel-injection channel | path of FIG. The longitudinal cross-sectional view of another conventional throttle body.

Explanation of symbols

DESCRIPTION OF SYMBOLS 1 Escape recessed part 1a Spherical surface part 2 Fuel injection path 2a Downstream 10 Intake path J Fuel injection valve

Claims (2)

In a throttle body in which a fuel injection valve is attached to a throttle body that is drilled through the intake passage and fuel injected from the fuel injection valve is supplied into the intake passage through the fuel injection passage.
A spherical portion 1 a is formed at the tip from the downstream side to the upstream side of the throttle body 10, a relief recess 1 facing the intake passage 11 is provided, and a downstream 2 a of the fuel injection passage 2 is formed on the spherical portion 1 a of the relief recess 1. A throttle body in a fuel injection device characterized by opening toward the front. 2. The fuel injection device according to claim 1, wherein the center R of the spherical surface portion 1 a of the escape recess is provided within the extension line of the diameter d of the fuel injection passage 2 and within the diameter D of the intake passage 10. Throttle body in Japan.

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