JPS6123862A - Fuel injection controller - Google Patents

Abstract

PURPOSE:To permit the laminar injection and reduce the dimension of the apparatus by forming the first and the second fuel passages and joining these fuel passages to the vicinity of the seat part at the top edge of a needle valve. CONSTITUTION:The second fuel passage 10 is filled with light oil. When the light oil reaches to the top edge of a needle valve 3, the light oil pushes-away the alcohol previously filling the first fuel passage 8 from the vicinity of a seat part and fills the top edge part of an injection nozzle 1. Then alcohol is supplied to the first fuel passage 8, and the pressure increases. Then, the needle valve 3 rises, and the light oil filling the top edge part of the nozzle is jetted-out at first, and then alcohol is jetted-out. Since the filling of light oil and injection of alcohol are repeated in succession, the ignition of light oil and the combustion of alcohol are carried-out favourably.

Description

DETAILED DESCRIPTION OF THE INVENTION Field of Industrial Application The present invention relates to the structure of a fuel injection nozzle for an internal combustion engine, and in particular to an internal combustion engine in which dissimilar fuels, ie, a first fuel and a second fuel, are injected in a layered manner without mixing. The present invention relates to a fuel injection control device for an engine.

BACKGROUND ART One type of engine that burns different types of fuel is one in which, for example, light oil is first injected into a combustion chamber, and then, for example, alcohol is injected to operate the engine. In engines that use such different types of fuel, in order to minimize the amount of light oil that is injected as an ignition source and burn alcohol, the different types of fuels are burned in layers without being mixed. Must be sprayed indoors.

For this reason, a device has been proposed in the past, for example, as disclosed in Japanese Patent Application Laid-Open No. 49-85423, in which a single nozzle is provided with two needle valves and different types of fuel are respectively injected.

Problems to be Solved by the Invention However, in this case, there was a problem in that the structure of the injection nozzle was complicated and large.

In view of the above-mentioned problems, an object of the present invention is to provide a fuel injection control device for an internal combustion engine that has a simple configuration, can be made small, and can reliably perform stratified injection without mixing different types of fuel. do.

Means for Solving the Problems In order to achieve this object, the fuel injection control device of the present invention includes a valve body having an injection port for injecting fuel, and a valve body that is slidably fitted into the valve body. A first fuel injection nozzle is provided with a needle valve that is held and opens and closes the injection port.
A second fuel passage is provided for supplying different types of fuel from the fuel passage and the fuel supplied by the first fuel passage, and the two passages are merged near the seat portion at the tip of the needle valve.

In the above structure, the first fuel passage may be formed in an annular shape between the inner peripheral surface of the valve body and the outer peripheral surface of the needle valve, and the second fuel passage may be formed within the shaft of the needle valve.

Further, the first fuel passage and the second fuel passage may be provided in a sliding fit holding surface between the valve body and the needle valve, so as to be separated from each other at a portion other than the merging portion near the seat portion. .

Furthermore, a cylindrical sleeve is interposed between the valve body and the needle valve to form two passages separated by the cylindrical sleeve except for the vicinity of the seat part, one being a first fuel passage and the other being a first fuel passage. It is also possible to have two fuel passages.

According to the present invention, the structure is simple and only one injection port is used.
From □, different types of fuel can be injected in layers without mixing, making stable combustion possible.

Furthermore, it can be made smaller, and the installation has a great advantage in terms of space.

EXAMPLES Below, preferred embodiments of the present invention will be described with reference to the drawings. 1 to 4 show a first embodiment of the present invention. In FIG. 1, an injection port 6 for injecting fuel is formed at the lower end of a nozzle body 2 of an injection nozzle 1. As shown in FIG. Further, the center of the nozzle body 2 is hollow, and a needle valve 3 is slidably fitted into the nozzle body 2, and a tapered part 4 at the tip thereof is inserted.
can be brought into close contact with the seat portion 5 on the nozzle body 2 side. Therefore, the injection port 6 is opened and closed by the vertical movement of the needle valve 3. Further, the tip tapered portion 4 of the needle valve 3,
An annular first fuel passage 8 is formed in the middle of the sliding portion with the nozzle body 2 and communicates with a communication passage 7 extending from the upper end of the nozzle body 2 . On the other hand, a second fuel passage 10 is formed within the shaft of the needle valve 3, and opens into a communication passage 11 toward the tapered tip portion 4 of the needle valve 3. The communication passage 11 opens near the seat portion 5 of the nozzle body 2 and is connected to the first fuel passage 8 . On the other hand, an annular groove 12 is formed in the inner peripheral surface of the nozzle body 2 corresponding to the open end of the second fuel passage 10, and is connected to a communication passage 9 extending from above the nozzle body 2.

FIG. 2 shows a cross section taken along the line I[-If in FIG. An annular groove 13 similar to 12 is formed in the sliding portion 16 on the nozzle body 2 side, and is connected to a fuel leak passage 14 extending from a communication groove 15 formed in the upper end surface of the nozzle body 2. FIG. 3 illustrates the arrangement of the communication passages 7, 9, and 14 when viewed from above in FIG. 2. This fuel leak passage 14 and annular groove 1
3 prevents the fuel in the annular groove 12 communicating from the first fuel passage 8 and the second fuel passage 10 from being mixed in the vibrating part 16. That is, when fuel is supplied to each passage at high pressure, the fuel leaks into the annular groove 13 where the pressure is low, and the mutual flow of fuel into the annular groove 12 and the first fuel passage 8 is prevented.

FIG. 4 shows an injection nozzle according to the present invention applied to a four-cylinder diesel engine. Its configuration is as follows. Injection nozzle 1a.

Ib and 1O-11d are prepared for the number of cylinders of the engine. Furthermore, the same number of fuel pressure bags f as the number of injection nozzles 1 are added.
125a, 25b, 125c, and 25d are arranged. This pressure feeding device 25 is for feeding fuel with good ignitability, such as light oil, and as shown in the cross section of 25b,
It is composed of two communication passages 26 and 30 and a piston 27 that connects the two communication passages. Piston 27 is spring 2
9 is pressed against the stepped portion 28, but the communication path 2
When the pressure of the fuel in the communication passage 30 increases, the piston 27 rises against the force of the spring 29 and compresses the fuel in the communication passage 30. At this time, the communication passage 30 is provided with a check valve 31 and a check valve 32, and the fuel in the communication passage 30 flows only in the right direction in the figure.

The fuel tank 20 is filled with alcohol, which has poor compression ignitability, and the fuel tank 21 is filled with light oil, which has good ignitability. Alcohol is sucked into the oil feed pump 22 through a pipe 33 and supplied to the fuel injection pump 24 through a pipe 34.

The fuel injection pump 24 compresses alcohol at high pressure and supplies it to each fuel pumping device from its discharge port. At this time, the cylinders of the engine and the discharge ports of the injection pump are matched. In other words, I
In the case of a cylinder, the fuel pumping device 25 is provided via the pipe 37a.
Alcohol is fed under pressure to the pipe 38a, and further supplied to the injection nozzle 1a through the pipe 38a.In the case of the cylinder (2), the pressure feeding device 25b is relayed through the pipe 37b, and then the alcohol is fed to the injection nozzle 1a through the pipe 38a.
b to injection nozzle 1b, in the case of ■ cylinder, 37d → 25
．． d → 38d → 1C, respectively. The pressure-fed alcohol is supplied to the first fuel passage 8 through the communication passage 7 of each injection nozzle 1, and when the pressure rises sufficiently, the needle valve 3 is pushed up and alcohol is injected from the injection hole 6.

On the other hand, light oil flows from the fuel tank 21 through the pipe 35 to
Each fuel pressure feeding device 25a from the pipe 36 with the oil feeding pump 23
, 25b, 25c, and 25d.

If the injection timing of diesel oil and alcohol is performed at the same time, the diesel oil will not be ignited efficiently and the alcohol will not be burned stably.

Therefore, in order to inject light oil before alcohol,
Fill the injection nozzle with light oil in advance. To do this, use the injection order to use the alcohol injection cycle of other cylinders before the alcohol injection cycle of your own cylinder, and fill the diesel oil at a low pressure that does not cause it to be injected from the injection nozzle. In the alcohol injection cycle, alcohol is injected while pushing out the light oil filled first.

The injection order in this example is I −1[[−1V−
■It is. Therefore, as shown in FIG. 3, the light oil pressurized by the fuel pumping device 25a is passed through the pipe 39a.
(2) Supplied to the injection nozzle 1C of the cylinder. Similarly 25b
From there, pipe 39b goes to the injection nozzle 1a of the construction pipe, 2
From 5c, it is supplied to 1d through a pipe 390, and from 25d, it is supplied to 1b through a pipe 39d. In the case of the injection nozzle 1a, for example, light oil is supplied to the communication passage 9, and further passes through the sliding part, and then fills the second fuel passage 10. When reaching the tip of the needle valve 3, the first fuel passage 8, which had been filled in advance from near the seat of the injection nozzle 1,
The alcohol inside is pushed out and the tip of the injection nozzle 1 is filled. Next, when alcohol is fed under high pressure from the discharge port of the injection pump 24, the alcohol is sent from the pipe 38a to the first fuel passage 8 via the pipes 37a and 25a. A check valve 32 is provided in the fuel pressure-feeding bag [25b, which has delivered the fuel, to prevent the backflow of light oil from the injection nozzle 1a to the fuel pressure-feeding device 25b, and the pressure in the first fuel passage 8 increases. . Then, the needle valve 3 rises, and the light oil filling the nozzle tip is injected first, and then the alcohol is injected. In this way, the filling of light oil and the injection of alcohol are repeated in sequence, and the light oil is ignited and the alcohol is combusted well.

5 to 9 show a second embodiment of the invention.

In FIGS. 5 to 9, reference numeral 41 indicates the entire fuel injection nozzle, and an injection port 45 is opened at the tip of the nozzle body 42. In FIG. This injection port 45 is opened and closed by a tapered tip portion 46 of a needle valve 44 inserted into the center of the nozzle body 42 and a seat portion 42 of the nozzle body 42 . On the other hand, a distance piece is coaxially joined to the upper end of the nozzle body 42 using, for example, a knock bottle.

Communication passages 50 and 51 are opened in the distance piece 43, respectively, and are aligned with the cutting line Vl- of FIG. 5 as shown in FIG.
A communication groove 52 in the cross section of the nozzle body 42 along Vl.
53 respectively.

The nozzle body 42 has an inner circumferential surface 55 that is slidably in contact with an outer circumferential surface 54 of the needle valve 44, as shown in FIG. , a first fuel passage 48 having a four-part shape, and a second fuel passage 48 having a four-part shape.
Fuel passage 49 opens. At this time, the first fuel passage 48 and the second fuel passage 49 are separated by a sliding surface formed by the outer peripheral surface 54 of the needle valve 44 and the inner peripheral surface 55 of the nozzle body 42 . Returning to FIG. 5 again, the communication groove 52 is connected to the first fuel passage 48, and the communication groove 53 is connected to the second fuel passage 49. First and second fuel passages 48 and 49 extending to the tip of the nozzle body 42 communicate with each other through an annular passage 56 formed on the nozzle body 42 side.

8 and 9 show shapes of the first fuel passage 57, 58 and the second fuel passage 59, 60 that are different from the shape shown in FIG. 7, and may take such shapes.

The configuration of the fuel injection nozzle 41 of the second embodiment applied to a diesel engine is similar to that of the first embodiment.

Further, the operation in the second embodiment is also similar to that in the first embodiment.

10 to 14 show a third embodiment of the present invention.

In FIG. 10, 61 is the entire injection nozzle, and an injection port 64 for injecting fuel is opened at the lower end of the nozzle body 62. A cylindrical sleeve 63 is coaxially joined to this nozzle body 62 by, for example, a dowel pin. The lower end of the cylindrical sleeve 63 has a sleeve shape,
Nozzle body 6 along inner circumferential surface 72 of nozzle body 62
2 to the lower end. At this time, the inner circumferential surface 72 of the nozzle body 62 and the outer circumferential surface 71 of the cylindrical sleeve 63 do not come into close contact with each other, but exhibit a spatial volume, thereby forming a second fuel passage 73 . On the other hand, the needle valve 66 is slidably fitted and held in the cylindrical sleeve 63, and a tapered portion 67 at the lower end of the needle valve 66
is tightly closed to the seat portion 65 of the nozzle body 62. Therefore, the injection port 64 is opened and closed by moving the needle valve 66 up and down. Although the upper end outer peripheral surface 80 of the needle valve 66 and the inner peripheral surface 81 of the cylindrical sleeve 63 are in close contact with each other, the needle valve 66
The lower end outer circumferential surface 68 and the inner circumferential surface 69 of the cylindrical two-shaped sleeve 63
do not come into close contact with each other, exhibiting a spatial volume and forming the first fuel passage 70. The second fuel diagonal passage 73 and the first fuel passage 7
0 are communicated by an annular passage 74 at the lower end. Further, a communication passage 79 opening in the cylindrical sleeve 63 is connected to the first fuel passage 70 via an annular vortex 77 and a groove 78, and the communication passage 76
is connected to the second fuel passage 73 via a communication groove 75 formed in the nozzle body 62. FIG. 11 shows a cross section taken along the line XI-XI in FIG.
9 shows the separation between a first fuel passage 70 formed by 9 and a second fuel passage 73 formed by an outer circumferential surface 71 of the cylindrical sleeve 63 and an inner circumferential surface 72 of the nozzle body 62.

FIG. 12 shows another aspect of the third embodiment of the present invention, and is a cross-sectional view of the injection nozzle taken horizontally, similar to FIG. 11, but in this aspect, the cross-sectional shape of the cylindrical sleeve is different. ing. That is, the first fuel passage 83 is formed by the outer peripheral surface of the needle valve 66 and the inner peripheral surface of the cylindrical sleeve 82, and the outer peripheral surface of the cylindrical sleeve 82 forming the second fuel passage 84 has a substantially square shape. A support portion 87 is formed in close contact with the inner circumferential surface of the nozzle body 62, so that the nozzle body 62, the cylindrical sleeve 82, and the needle valve 66 can be easily arranged coaxially.

FIG. 13 also shows another aspect of the third embodiment, in which a needle valve 94 that is slidably fitted and held in a nozzle body 92 equipped with an injection port 93 is inserted. The injection port 93 is opened and closed by the close contact between the lower end tapered portion 103 and the seat portion 102 of the nozzle body 92 . An outer circumferential surface 95 of the needle valve 94 and an inner circumferential surface 96 of the nozzle body 92 form a space, into which a cylindrical sleeve 97 is inserted. The cylindrical sleeve 97 is a stepped portion of the nozzle body 92]
04, and its upper end is pressed and held in the groove 105 of the nozzle body 92, and is divided into a first fuel passage 99 and a second fuel passage 101. Further, the first fuel passage 99 has a communication passage 98 , and the second fuel passage 101 has a communication passage 100 .
are connected to each other. 14, the lower end of the sleeve 97 (the part in contact with the stepped portion 104) has a notch 106, which connects the first fuel passage 99 and second fuel passage 101 in FIG. Communication is established near the portion 103.

The structure and operation of the injection nozzle applied to the deep-pil engine in the third embodiment are the same as those described in the first embodiment, and therefore the explanation thereof will be omitted.

Effects of the Invention According to the present invention, with a simple configuration, different types of fuel can be injected in layers from one injection port without mixing, and stable combustion is possible. Moreover, it can be made smaller and has a great advantage in mounting space.

[Brief explanation of drawings]

FIG. 1 is a cross-sectional view of a fuel injection valve in a fuel injection control device according to a first embodiment of the present invention, FIG. 2 is a cross-sectional view taken along the line ■-■ in FIG. 1, and FIG. 4 is a system diagram when the fuel injection valve according to the present invention is applied to a 4-cylinder diesel engine, and FIG. 5 is a diagram showing the second embodiment of the present invention.
A cross-sectional view of a fuel injection valve in a fuel injection suppressing device according to an embodiment, FIG. 6 is a cross-sectional view taken along the line Vl-Vl in FIG. 5, FIG. 7 is a cross-sectional view taken along the line ■-■ in FIG. 5, FIG. 8 shows the first and second parts of the second embodiment of the present invention, which have a different shape from those shown in FIG. 7.
9 is a sectional view of a fuel injection valve having a fuel passage, and FIG. 9 is a sectional view of a fuel injection valve having first and second fuel passages having a shape different from that of FIGS. 7 and 8 in the second embodiment of the present invention. 10 is a sectional view of a fuel injection valve in a fuel injection control device according to a third embodiment of the present invention, and FIG.
12 is a sectional view taken along the line I-XI, FIG. 12 is a sectional view of a fuel injection valve having first and second fuel passages of a different shape from FIG. 11 in a third embodiment of the present invention, and FIG. FIG. 14 is a sectional view of a fuel injection valve in a different aspect from FIG. 10 according to a third embodiment of the invention, and FIG. 14 is a perspective view of the lower part of the cylindrical sleeve. 1...Fuel injection nozzle 2.42.62. 64.92... Nozzle body 3.44.66.94... Needle valve 4...
...Tapered part 5.47.65.102 ・= -Shi t- part 6.45.
64.93...Injection lower, 9.11.26. 30.50, 51.79...Communication path 8.48.
70. 83.99...First fuel passage 10.49.73. 84.101...Second fuel passage 12...
・Annular groove 13.77...Annular groove 14...Fuel leak passage 15.52.53.75...Communication groove 16...
... Vibration part 20.21 ... Fuel tank 22.23 ... Oil feed pump 24 ... Fuel injection pump 25 ... Fuel pressure feeding device 27. ... Piston 28 ... Step portion 29 ... Spring 31.32 ... Check valve 33.34.35.36. 37.38.39...Vibro 3.82.97...Cylindrical sleeve 1st drawing ■ No. 0 Fig. 13 Fig. 14

Claims (4)

[Claims] (1) A first fuel passage is connected to a fuel injection nozzle that includes a valve body having an injection port for injecting fuel, and a needle valve that is slidably fitted and held in the valve body to open and close the injection port. and a second fuel passage supplying fuel of a different type from the fuel supplied by the first fuel passage, and both passages are merged near the seat portion at the tip of the needle valve. Control device. (2) The fuel according to claim 1, wherein the first fuel passage is formed in an annular shape between the inner peripheral surface of the valve body and the outer peripheral surface of the needle valve, and the second fuel passage is formed within the shaft of the needle valve. Injection control device. (3) A patent in which a first fuel passage and a second fuel passage are provided on the sliding fitting holding surface of the valve body and the needle valve so as to be separated from each other at a portion other than the merging portion near the seat portion. A fuel injection control device according to claim 1. (4) A cylindrical sleeve is interposed between the valve body and the needle valve, and the cylindrical sleeve forms two passages separated except for the vicinity of the seat part, one of which is a first fuel passage;
The fuel injection control device according to claim 1, wherein the other is a second fuel passage.