RU1825888C - Injector for internal combustion engine - Google Patents

Abstract

SUMMARY OF THE INVENTION: an additional chamber is made in the spray gun of the formula, into which, when the needle is raised as much as possible, part of the fuel flows from the needle room connected to the fuel supply channel, as a result of which the pressure increase in the latter less sharply. 1 s.p. file, 3 ill.

Description

The invention relates to the field of engine building and is intended to inject fuel, mainly into a diesel engine.

The purpose of the invention is to increase injection efficiency and simplify nozzle design.

The protected nozzle differs from the prototype in that the distance between the needle room and the additional cameras is less than the maximum needle stroke, and the diameter of the step of the guide part from the side above the needle chamber is 1.0 ... 2.0 of the step diameter from the side of the needle chamber ; the volume of the additional camera is equal to 0.2 ... 1.0, the volume of the needle chamber.

The invention is as follows.

In the prototype, the fuel is compressed in two chambers before being fed into the nozzle openings, which leads to a decrease in the injection pressure, since the pressure decreases with an increase in the compression volume. In addition, in the analogues and prototype we add both the nozzle and the entire fuel system. In the proposed nozzle at idle and low load conditions, the fuel is compressed in the needle chamber, which increases the injection pressure, and as the cyclic supply increases, the fuel is compressed in two chambers so that the pressure in the system does not increase excessively. This helps to increase the reliability and service life of the nozzle. It should also be noted that the proposed nozzle is much easier to manufacture, assemble and operate, as well as during repair and maintenance.

By varying the volume of the cavities, the diameters of the individual parts of the needle, the distances between the cavities and the course of the needle when refining a particular engine and nozzle, it is possible to achieve a stable and efficient injection of fuel depending on the mode of operation of the engine, which cannot be achieved in the prototype and in analogues. This allows us to conclude that the claimed nozzle and aspect ratio are interconnected by a single inventive concept.

In FIG. 1-3 are schematic diagrams of the nozzle with the same (Fig. 1,2) and with different (Fig. 3) diameters of two precision s

AND

00

to

(I AM

with

00

areas of the locking needle and the spray, and in figure 1 an additional chamber is made in the spray, and in figures 2 and 3 - in the spray and locking needle.

The nozzle contains a housing 1 with a fuel supply channel 2, a sprayer 3 with an annular groove 4 and a channel 5, a locking needle 6, overlapping the well 7 and nozzle holes 8. The needle 6 is closed by a spring mechanism or liquid, which can be used as working fuel . The needle chamber 9 is constantly in communication with the channel 5, is located closer to the well 7 and is separated from the additional chamber 10 by a precision section 11, the mating length of which is less, for example, equal to 0.2-0.8 of the maximum needle travel to the ears. The diameter da of the precision portion 12 is 1.0 to 2.0 times the diameters of the first portion SN. The locking needle has one 13 (Fig. 1,2) or two 13 and 14 (Fig. 3) differential pads. The volume V2 of the chamber 10 is equal to 0.2-1.0 of the volume Vi of the chamber 9. The housing 1 is a stop for the needle, limiting its pressure. The surface 15 of the chamber Vz is beveled to increase the reliability of the nozzle.

Fuel injection is carried out as follows. The fuel from the injection pump through the channel 12, the annular groove 4 and the channel 5 in the atomizer 5 enters the chamber 9 and is compressed therein with increasing pressure. Part of the fuel, through the precision section 11, enters the cavity 10, in which it is also compressed. When the force from the pressure of the fuel on the needle below becomes greater than the force from the locking mechanism, determined by the tightening of the spring or the pressure of the locking liquid, the needle rises and part of the fuel through the well 7 enters the nozzle holes 8. When, the fuel enters the chamber 10 through the cross section between the needle and the nozzle, determined by the diameter di and height (y-x). The maximum cross section will be when the needle reaches the stop, when the height of the cross section is equal to (max-x).

At low load and rotational speed modes, including idle modes, compression and increase of fuel pressure before sawing are carried out mainly in chamber 9. At medium and high load and rotational speed modes, for example, at higher than 0.3-0, 4 of the nominal value, compression and increase in fuel pressure are carried out: in the initial stage a of chamber 9, and as the needle moves upwards, when, in two chambers 9 and 10.

Compression and increase in fuel pressure before entering the well in modes

0

low loads and rotational speeds, including idling, in the chamber 9 helps to increase the fuel injection pressure, i.e. injection efficiency. At the same time, this contributes to the stability of injection, since the fuel in these modes is compressed in a small volume.

With an increase in the load and speed, the chambers 9 and 10 communicate with each other, which allows them to compress a greater amount of fuel without a sharp increase in pressure in them, which also contributes to efficient and stable fuel injection in medium and heavy loads and rotation frequencies. The foregoing can be explained by an analysis of the fuel balance equation (fuel continuity equation).

Before the needle begins to move, the equation of continuity of fuel motion will be as follows:

 d RF1 a

(1)

5

where from

0

5

0

t d-Vni-a), (2)

dt avi

where a is the compressibility factor of the fuel; Vi is the volume of the needle room; fr is the passage sectional area of channel 5 at the outlet to chamber 9; St is the speed of the fuel in the output section of the channel 5; Vni-2 is the second flow of fuel flows from the chamber 9 into the chamber 10 through the mating surface 11; Pf1 - fuel pressure in the chamber 9; t is time.

It can be seen from equation (2) that the pressure RF1 increases with decreasing Vi, ceteris paribus. Vni-2 is greater, the smaller the length of the mating surface 11.

When Рф1 becomes equal to Рф0, the needle begins to move and the equation of continuity of motion of the fuel will be as follows:

 -CT-Vni-2- c -fc -Сс- No., (3)

where fic fc CC - second fuel consumption through nozzle openings;

f 1 l di2 / 4 is the cross-sectional area of the needle along the first precision section 11; C is the speed of the needle.

5

From equation (3)

ЈW fT CT-Vn1-2- fcX

x Cc - f 1 C. (4)

As the fuel leakage increases, the pressure Pf1 decreases.

The crossflows will be large as the needle moves upward, increase substantially at and will be maximum at

.

The pressure in the working cavity 10 is determined as follows. With a stationary needle

 Vn1 2 - Vn2,

(Vnl-2-Vnz).

where Va is the volume of the chamber 10: Рф2 is the fuel pressure in the chamber 10;

Vn2 is the second flow rate of fuel flows from the chamber 10 into the supra-needle cavity through the second conjugate surface 12, which is determined by the pressures Pf2 and the fuel pressure in the supra-needle cavity, for example, the pressure of the locking fluid when the nozzles are hydraulically locked.

When the needle moves, the pressure in the working cavity 10 is determined as follows

a v2 ЈЈЈЈ Vni-a - Vn2 - f2 Cu, (7) at

where from

- „“ -v-e-h-CAro

where h Jtd22 / 4 is the cross-sectional area of the needle in the second precision section 12.

With an increase in Vni-2 and a decrease in Vn2 (8), the pressure in the chamber 10 increases, and the area fa also affects Pf2.

In this regard, depending on the purpose of the engine, the operating characteristics of the fuel system and the engine, the distance between the working cavities is made smaller, for example, equal to 0.2-0.8 of the maximum needle stroke, with only one chamber 9 communicating with channel 5. located closer to the sprayer well, and V2 (0.2 ... 1.0) Vi; d2 (1,0 ... 2,0 di By varying these parameters within the specified limits, when creating and refining the fuel equipment for a particular engine, stable and effective injection of fuel into the engine cylinder is achieved depending on its operating mode, which is impossible to achieve in the prototype and analogues .

It should also be noted that the protected nozzle is much simpler to manufacture, assemble and operate, as well as during repair and maintenance, which confirms the reliability of the achievement of the technical result, and does not represent

difficulties creating nozzles in existing mass production and. furthermore, serial needle and spray blanks can be used 5

One of the most important advantages of a protected nozzle is the possibility of using it on all types of fuel equipment, for example, during hydraulic locking

10 nozzles, nozzles without a drain line, with widespread spring locking of nozzles, in pump nozzles, in fuel systems with electromagnetic control of nozzles, in

15 of the battery fuel equipment, the nozzles being normally closed, i.e. multi-hole, pin, valve, valve-nozzle, with detachable nozzle tip.

Thus, the invention allows the fuel to be stably and efficiently injected in a wide range of modes with simultaneous simplification of the nozzle, and Pf0 does not decrease with an increase in the angular rotation speed, which takes place in the prototype. If in the prototype the separator, the diameter of which is larger than the diameter of the guide part of the needle, degrades the manufacturability of the needle and forces

If the spray gun is composite, that is, with a detachable nozzle tip, then according to our decision, the needle manufacturing technology is simplified, and the spray gun can be made both integral and composite.

Claims (2)

1. An injector for an internal combustion engine, comprising a body with a fuel supply channel, a nozzle mounted on the body with a seat, nozzle holes 40 and a cavity separated by a jumper, and a needle with a differential pad, a two-stage guide and locking parts, located in the nozzle cavity with the formation of a sub-needle, additional and sup-needle chambers separated by a guide part, and the differential platform is made between the guide and locking parts and enters a positive cavity, Generalized with the fuel supply channel and nozzle holes, and the edge formed by the intersection of the surfaces of the guide part and the differential platform is located at the level of the crossbar 55 when the needle is on the saddle, characterized in that, in order to increase the injection efficiency and simplify the design, the distance the distance between the needle room and the auxiliary camera is less than the maximum needle stroke, and the diameter of the step of the guide part from the side of the needle chamber is 1.0-2.0 of the diameter of the step from the side of the needle camera. 13 7 9 13 2 m # eleven 2. Injector 1, distinguished by the fact that the volume of the additional camera is equal to 0.2-1.0 of the volume of the needle chamber. 139 1 13 g / figz Editor E. Savina Compiled by A.Karakaev Tehred M. Morgenthal Corrector E. Papp