JPH0441973A - Nozzle with holes variable in number - Google Patents

Abstract

PURPOSE:To miniaturize the title device and simplify its construction by using one fuel injection nozzle in such a manner as to inject fuel through plural holes in a low speed/low load and inject fuel through a single hole in high speed/heavy load. CONSTITUTION:In a low speed/low load of an engine, a rotary valve 12 is controlled to communicate an oil tube 11 with a fuel pump side. Consequently, high pressure fuel from the fuel pump is supplied from the oil tube 11 to an oil chamber 22 and an oil sump 35 of a nozzle main body 1. Meanwhile, fuel from the oil tube 13 is supplied to the oil chambers 31 and 32. In this case, oil pressure in the oil chamber 33 energizes downwardly a needle valve 4, which closes a single hole 38. Meanwhile, when the pressure in an oil chamber 22 reaches a specified value, which causes a nozzle 3 to be driven downwardly with a piston 25 against the energizing force of a spring 32. Thus, the plural holes 39 is opened, fuel from the oil sump 35 is injected from the plural holes 39.

Description

DETAILED DESCRIPTION OF THE INVENTION (Field of Industrial Application) The present invention relates to a variable nozzle with a variable number of injection holes that can change the number of fuel injection holes depending on the operating condition of an engine.

(Prior art) Conventional fuel injection nozzles use either a single hole nozzle with a single nozzle hole or a multi-nozzle nozzle with multiple nozzle holes depending on the strength of the vortex flow velocity in the combustion chamber. .

When the vortex velocity inside the combustion chamber is small, fuel is injected into the air inside the combustion chamber using a multi-hole nozzle, and the fuel is vaporized by the heat energy transferred from the air, creating an air-fuel mixture. let

On the other hand, when the vortex velocity inside the combustion chamber is high, the fuel is injected against the wall surface of the combustion chamber using a single hole nozzle, and the fuel is vaporized by the thermal energy transferred from the inner wall surface, resulting in a mixture of air-fuel mixture. generate.

However, in order to increase the vortex velocity within the combustion chamber, it is necessary to restrict the direction of intake air when it is taken into the combustion chamber, resulting in an increase in intake resistance and a decrease in volumetric efficiency. There is.

Therefore, the direct injection impingement method injects alcohol fuel from a single injection hole nozzle into the piston head into the combustion chamber where the vortex velocity is low, and causes the alcohol fuel to collide with the piston head and diffuse into the air supply. As a diffused stratified air supply system,
Internal Combustion Engine J Vol, 27No, 3451988.7
It is described in P35 to P44.

(Problems to be Solved by the Invention) According to the above-mentioned direct injection collision-diffusion stratified air supply system, it is said that the net thermal efficiency and output of the engine to which the system is applied are improved, but During load and startup, the temperature of the piston head surface is low, so alcohol fuel, which requires a larger amount of latent heat of vaporization than normal fuel, is difficult to vaporize, so the fuel and air are mixed well. normal combustion cannot be expected.

The above problem can be solved by injecting fuel from the multi-hole nozzle at low speeds and low loads and during startup, but the engine must be equipped with a single-hole nozzle and a multi-hole nozzle. However, there are problems in that it cannot be applied and the control device becomes complicated.

The present invention has been made in view of the above points, and it is an object of the present invention to provide a variable number of nozzle nozzle that can operate as a multi-nozzle nozzle or a single nozzle with a single fuel injection nozzle. .

(Means for Solving the Problems) According to the present invention, a first nozzle hole passing through the bottom of the bottomed cylindrical body, and a plurality of injection holes passing through the side wall surface near the bottom of the bottomed cylindrical body. A second nozzle hole, a first opening/closing means for opening and closing the first nozzle hole, and a second opening/closing means for opening and closing the second nozzle hole are always closed depending on the operating state of the internal combustion engine. It is possible to provide a variable nozzle number nozzle characterized by having a control means for opening a desired one of the first and second opening/closing means.

(Function) In the variable nozzle number nozzle of the present invention, a single fuel injection nozzle is provided with multiple injection holes and a single hole, and the opening and closing of the multiple injection holes and the single hole can be controlled by separate control systems. It is equipped with an opening/closing means.

Depending on the operating condition of the engine, at low speed and low load, the multiple injection holes are opened and fuel is injected from the multiple injection holes. Further, at high speed and high load, the single hole is opened and fuel is injected from the single hole.

The operation of the opening/closing means is controlled by a simple control operation such as switching a rotary valve.

(Example) Embodiments of the present invention will be described in detail below with reference to the drawings.

FIG. 1(a) is a sectional view showing the structure of a variable nozzle with a variable number of injection holes according to the present invention.

In the figure, 1 is a nozzle body, and the nozzle body 1 has an oil pipe 11 communicating with a fuel pump (not shown), and an oil pipe 13 communicating with a fuel pump and a tank (not shown) via a rotary valve 12. are connected. Incidentally, the rotary valve 12 is connected to the oil pipe 13 by an external signal.
The fuel pump communicates with either the fuel pump or the tank.

Reference numeral 2 denotes a cylinder, and an oil passage 21 bored in the cylinder 2 is connected to the oil pipe 11 and guides fuel to an oil chamber 22 provided inside the cylinder 2. Further, a separately provided oil passage 23 is connected to the oil pipe 13. A cylindrical holder 24 is provided at the tip of the cylinder 2.
are connected. The holder 24 is divided into two parts in the left and right direction in the figure, and after being combined into a cylindrical shape, the holder 24 is held by a stopper (not shown).

The oil chamber 22 is provided with a piston 25 and a nozzle 3 that slides on both the oil chamber 22 and the inner peripheral surface of the holder 24.

An oil chamber 31 is provided on the outer peripheral surface of the nozzle 3.
1 is communicated with the oil passage 23 mentioned above. A spring 32 is disposed inside the oil chamber 31 and urges the nozzle 3 upward in the figure. Further, an oil chamber 33 communicating with the oil chamber 31 is provided at the upper end of the nozzle 3, and a spring 34 is disposed in the oil chamber 33.

Further, an oil reservoir 35 is provided inside the nozzle 3, and the oil in the oil chamber 22 is fed to the oil reservoir 35 through an oil passage 36 formed in both the piston 25 and the nozzle 3. is supplied.

Furthermore, a flange 37 is provided at the tip of the nozzle 3, a single hole 38 is bored in the center of the flange 37, and a plurality of multiple injection holes 39 are bored in the upper part of the flange 37. has been done.

The upper surface of the flange 37 is pressed against the lower end surface of the holder 24 by the biasing force of the spring 32, and the multiple injection holes 39 are closed by the holder 24.

Further, a needle valve 4 is slidably held inside the nozzle 3, and the single hole 38 is connected to the spring 34.
The needle valve 4 is closed by the needle valve 4 energized by the needle valve 4 .

By the way, FIG. 1(b) is a perspective sectional view of the tip of the nozzle 3.

Next, the operation of the variable nozzle with the above configuration will be explained.

FIG. 2 is a sectional view showing injection from multiple injection holes.

When the engine is operating at low speed and low load, the rotary valve 12 is controlled and the oil pipe 1 is communicated with the fuel pump side. Then, high-pressure fuel from the fuel pump is first supplied to the oil chamber 22 and oil sump 35 from the oil pipe 11. On the other hand, fuel from the oil pipe 13 is supplied to the oil chamber 31 and the oil chamber 33.

In this state, the oil pressure in the oil chamber 33 acts on the needle valve 4 and urges the needle valve 4 downward in the figure, so that the needle valve 4 closes the single hole 38. On the other hand, when the force S of the nozzle 3 is urged upward by the spring 32 and the pressure in the oil chamber 22 reaches a predetermined pressure or higher, the nozzle 3 is pushed down together with the piston 25 against the urging force of the spring 32. drive in the direction. Then, the multiple injection holes 39 are opened, and the fuel from the oil reservoir 35 is ejected from the multiple injection holes 39.

The predetermined pressure at which the multiple injection holes 39 are opened is determined by the strength of the spring 32, and is, for example, 240 k.
g/cm".

Next, the case of injection from a single hole will be explained.

FIG. 3 is a sectional view showing injection from a single hole.

When the engine is operating at high speed and high load, the rotary valve 12 is controlled to communicate the oil pipe 11 with the tank side. Then, high pressure fuel from the fuel pump flows through oil pipe 1.
1 to the oil chamber 22 and oil sump 35. On the other hand, the oil pressure inside the oil chamber 31 and the oil chamber 33 is released to the tank via the oil pipe 13.

The needle valve 4 is urged downward in the figure by a spring 34, but when the pressure in the oil reservoir 35 reaches a predetermined pressure or higher, it resists the urging force of the spring 34,
Drive the needle valve 4 downward. Then, singlet hole 3
8 is opened, and fuel from the oil sump 35 is jetted out from the single hole 38.

The predetermined pressure at which the single hole is opened is determined by the spring 34.
For example, 100 kg/
It is set to about cm2.

Therefore, since the pressure set by the spring 34 is lower than the pressure set by the spring 32, the nozzle 3 remains biased upward during injection from the single hole shown in FIG. It will never be released.

Although the embodiments of the present invention have been described in detail above, various different embodiments can be easily constructed without departing from the spirit of the present invention. Other than limitations, there is no intention to be bound by the particular embodiments.

(Effects of the Invention) As explained above, according to the present invention, one fuel injection nozzle opens the multiple injection holes at low speed and low load depending on the operating condition of the engine, and injects fuel from the multiple injection holes. At high speed and high load, the single hole is opened and fuel is injected from the single hole, so the device does not become bulky and can be applied to small engines.

Further, since the switching of the nozzle holes is controlled by a simple control operation such as switching of a rotary valve, a variable nozzle with a variable number of nozzle holes can be provided without complicating the control device.

[Brief explanation of the drawing]

FIG. 1(a) is a cross-sectional view showing the structure of a variable nozzle number nozzle according to the present invention, FIG. 1(b) is a perspective cross-sectional view of the tip of the nozzle 3, and FIG. A cross-sectional view showing the time of injection,
FIG. 3 is a sectional view showing injection from a single hole. DESCRIPTION OF SYMBOLS 1... Nozzle body, 2... Cylinder, 3... Nozzle, 4... Needle valve, 12... Rotary valve, 38-... Single hole, 39... Multiple injection holes. Patent applicant: Isuf Ceramics Research Institute Co., Ltd. Representative: Patent attorney Minoru Tsuji Figure 1

Claims (3)

[Claims] (1) A first nozzle hole penetrating the bottom of the bottomed cylindrical body, a plurality of second nozzle holes penetrating the side wall surface near the bottom of the bottomed cylindrical body, and the first nozzle nozzle hole penetrating the bottom of the bottomed cylindrical body. A first opening/closing means for opening/closing the hole, a second opening/closing means for opening/closing the second nozzle hole, and the first and second opening/closing means always closed depending on the operating state of the internal combustion engine. a control means for opening a desired one of the opening/closing means. (2) The variable nozzle number nozzle according to claim 1, wherein the first and second opening/closing means are operated by the fluid pressure of the fuel. (3) The variable number nozzle according to claim 2, wherein the control means is a rotary valve that switches the fluid pressure of the fuel supplied to the first and second opening/closing means.