JPH10331631A - Scavenging accelerator - Google Patents

Abstract

PROBLEM TO BE SOLVED: To furnish flexibility to provide a constant scavenging effect even when exhaust quantity changes to a certain degree and to reduce cost. SOLUTION: This device is furnished with an accelerating cylinder 10 having a connecting part 12 with an exhaust system pipe 11 on one end and an injection port 13 of exhaust gas on the other end and formed in a tapered shape to accelerate an exhaust gas flow and an enclosing cylinder 20 surrounding the outside of the accelerating cylinder 10 and provided and drilled on the upstream side of the accelerating cylinder 10 by negative pressure of a high degree in an annular clearance 21 continued on the overall periphery formed between itself and the injection port 13. Thereafter, a suction exhaust flow and an accelerating exhaust flow are discharged into the air from an exhaust cylinder 30 provided on the enclosing cylinder 20 rear end.

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to an apparatus for accelerating scavenging by accelerating the flow velocity of an exhaust gas flow reduced by the resistance of an exhaust system and discharging the exhaust gas to the atmosphere.

[0002]

2. Description of the Related Art For example, in the case of a piston engine, it is desirable that the exhaust gas be quickly released from the cylinder to the atmosphere from the viewpoint of engine efficiency. However, to keep the release location away from personnel,
In addition, an exhaust pipe is used from a safety point of view, and a muffler, a catalyst device, and the like are added to the exhaust pipe, and the back pressure becomes excessively large, obstructing the exhaust and reducing the scavenging efficiency. Focusing on this point, the present inventor has invented a system for discharging exhaust gas to the atmosphere in an accelerated state, and has filed applications in Japan and overseas.

Among them, there are inventions such as Japanese Patent Publication No. 7-42852 (Japanese Patent No. 2013958) and US Pat. No. 5,280,143 based thereon. These inventions aim at full utilization of exhaust energy, and improve the scavenging efficiency by utilizing the negative pressure formed thereby. However, the above-mentioned invention and the related inventions prior thereto do not solve the problem that the number of parts is large, and in addition to the problem that the desired effect cannot be obtained when the displacement of the piston engine changes. had. This causes a problem that various types of products need to be developed according to the size of the displacement.

[0004]

SUMMARY OF THE INVENTION The present invention has been made in view of the above-mentioned points, and an object of the present invention is to provide an effect adapted to each of the displacements even if the displacement changes to a certain degree. To have flexibility. Another object of the present invention is to make it possible to respond to the magnitude of the displacement by developing a smaller number of types of products and to reduce the number of parts, thereby facilitating cost reduction.

[0005]

In order to solve the above-mentioned problems, the present invention has a connection portion to an exhaust system pipe at one end and an exhaust gas injection port at the other end. The exhaust gas flow is accelerated by an accelerating cylinder that is formed in a tapered shape in which the cross-sectional area of the flow path gradually decreases for acceleration of the exhaust gas flow toward the outside, and has a through hole that opens to the outside on one end side, One end is connected to the accelerating cylinder upstream of the through-hole, and the other end surrounds the injection port of the accelerating cylinder to form an annular gap therebetween, and the annular gap is formed by a negative pressure generated by acceleration of the exhaust flow. And an enclosure that allows the exhaust gas flow to flow through the through-hole,
An exhaust pipe connected to the other end opening of the enclosing cylinder for discharging the accelerated exhaust stream injected from the injection port and the suction exhaust stream flowing out of the annular gap to the atmosphere, and the exhaust stream flowing downstream from the injection port is provided. A measure is taken to set the length of the exhaust tube to a length that can contact the exhaust tube.

[0006]

DESCRIPTION OF THE PREFERRED EMBODIMENTS An apparatus according to the present invention is an apparatus for accelerating scavenging by accelerating the flow velocity of an exhaust gas flow reduced by the resistance of an exhaust system and discharging the exhaust gas to the atmosphere.

The present invention follows the basic principle developed by the present inventor in accelerating the flow rate of the exhaust gas flow and releasing it to the atmosphere. That is, in the present invention, an acceleration section A for accelerating the exhaust gas flow to near the discharge speed from the combustion chamber, a negative pressure suction section B for extracting a high negative pressure generated by this acceleration, and discharging the high-speed exhaust gas stream to the atmosphere. The negative pressure suction unit B has a configuration that communicates with the exhaust gas flow before it is highly accelerated upstream and bypasses the exhaust gas flow at a high speed.

The accelerating portion A mainly accelerates the exhaust gas flow in the central portion of the exhaust pipe, whereas the accelerating portion A converts the exhaust gas flow near the exhaust pipe wall, which becomes relatively slow, into a negative pressure suction portion B by the above configuration. It is accelerated by the suction action of. The flow velocity in the negative pressure suction part B has almost reached the flow velocity in the acceleration part A, so that the exhaust gas flow becomes a high-speed air flow as a whole. The speed of this high-speed airflow reaches a stage close to the speed of sound, which means that the closer to the exhaust speed discharged from the cylinder, the more efficiently the airflow works. Increasing the exhaust gas flow rate will also increase the exhaust gas flow rate.

Therefore, the scavenging accelerating device of the present invention comprises an accelerating cylinder 10 having a tapered shape, an encircling cylinder 20 disposed outside the accelerating cylinder 10, and an accelerating exhaust flow accelerated by the accelerating cylinder 10 and the encircling cylinder 20. An exhaust stack 30 is required for venting the suction exhaust stream flowing out of the annular gap 21 therebetween to the atmosphere.
The accelerating cylinder 10 corresponds to the accelerating section A, the space between the accelerating cylinder 10 and the surrounding cylinder 20, particularly the vicinity of the annular gap 21, corresponds to the negative pressure suction section B, and the exhaust cylinder 30 corresponds to the atmospheric discharge section C. I do.

A feature of the present invention is that the flow path of the negative pressure suction portion, which has conventionally been constituted by a plurality of holes, is replaced by an annular gap 21 having only a complete flow path.
And the number of component parts for that purpose is basically minimized to about three. Annular gap 2
1 is continuous over the entire circumference, and there is no flow resistance part.
Less affected by changes in exhaust flow rate.

FIG. 1 shows a first embodiment of the apparatus according to the present invention. This device comprises an acceleration cylinder 10, an enclosure 20 and an exhaust cylinder 30.
, And each part is a single structure.

The accelerating cylinder 10 has a connection portion 12 to an exhaust system pipe 11 at one end and an exhaust gas injection port 13 at the other end to accelerate the exhaust gas flow from one end to the other end. To
Tapered wall surface 14 with gradually reduced cross-sectional area
Is formed between both end portions, and has a configuration in which a plurality of through-holes 15 communicating with the outside are opened in a wall surface on one end side. The exhaust gas flow bypassing the negative pressure suction part B passes through the through hole 15, and its radial position is located outside the inner diameter of the connection part 12. Reference numeral 16 denotes an inversely tapered wall surface, which provides an enlarged cross-sectional area immediately after the connection, so that the exhaust gas flow once tends to expand here.

The enclosing cylinder 20 has one end connected to the accelerating cylinder 10 upstream of the through hole 15 and the other end extending to the rear end of the accelerating cylinder to form an annular gap 21 with the outside of the injection port 13. . Therefore, the surrounding cylinder 20 substantially surrounds the accelerating cylinder 10, and the front end 22 thereof is fitted into the fitting concave portion 17 formed immediately before the through hole of the accelerating cylinder 10 to integrate the surrounding cylinder 20 with the accelerating cylinder 10. . The body perimeter 23 of the enclosure 20 forms a space 24 with the acceleration cylinder 10 and provides a bypass for the suction and exhaust flow. The exemplary space 24 has a gradual increase in flow path cross-section in contrast to the accelerator, but may not. The rear end 25 of the surrounding tube 20 is a portion to which the exhaust tube 30 is connected.

As the exhaust stream is injected from the injection port 13 while being highly accelerated by the acceleration section, immediately after that, a negative pressure is generated in proportion to the speed. In the present invention, the negative pressure region 31 is enlarged as the annular gap 21 in the present invention, and since there is no member serving as a resistance, the ability to suck by the negative pressure is remarkably enhanced. As a result, it is easy to deal with a change in the flow rate of the suctioned exhaust gas, especially when the flow rate is increased, and the flexibility is provided.

The accelerated exhaust stream and the suction exhaust stream are released from the exhaust stack 30 to the atmosphere as a high-speed exhaust stream. At this time, the high-speed exhaust gas is discharged to the atmosphere while diffusing downstream from the injection port 13, but the outer peripheral portion 32 maintaining the flow of the high-speed exhaust gas flow
The exhaust pipe 30 has a length that can contact the trailing edge 34 of the exhaust pipe 30.
Set the length of In this way, the rear negative pressure region 33 is closed by the outer peripheral portion 32, and a constant negative pressure can be maintained. On the other hand, if the outer peripheral portion 32 is not closed by the exhaust pipe 30, the desired effect cannot be sufficiently achieved.

FIG. 2 shows a second embodiment of the apparatus according to the present invention, which differs from the first embodiment in that the surrounding cylinder 20 is formed by combining a plurality of parts. Therefore, the surrounding cylinder 20 will be described.
9-1, 29-2, etc., constitute the trunk peripheral portion 23, and a separate rear end member 27 is used. Among them, many small holes can be formed in the innermost cylinder. Multiple cylinder 29
-1, 29-2 are held concentrically in fitting recesses 17 ', 27' at the front end 22 'and the rear end 25', and are integrated by a coupling shaft 28 which passes through the acceleration cylinder 10 and the rear end member 27. Be transformed into

Since other configurations may be the same as those of the first embodiment, reference numerals are used and detailed description is omitted. Example 2
Is suitable for a large-sized device as compared with the case of the first embodiment. Although the number of points is apparently increased as compared with that of the first embodiment, since the cylindrical bodies 29-1... Do not require processing, processing of three parts can be practically completed.

FIG. 3 shows a third embodiment of the device according to the present invention, which corresponds to the exhaust tube 30 of the first embodiment provided with a cooling cylinder 35. Therefore, other configurations may be the same as those of the first embodiment as indicated by reference numerals. The cooling cylinder 35 is formed to be equal to or slightly longer than the exhaust cylinder 30 and is connected at its front end to a mounting portion 36 at the rear end of the surrounding cylinder. A negative pressure portion 37 is formed at the rear end by the exhaust gas flow released to the atmosphere from the exhaust
External air can be introduced from the pores 38 between the cylinder 0 and the cooling cylinder 35 to lower the exhaust gas temperature.

FIG. 4 shows a fourth embodiment, in which a cooling cylinder 35 is added to the second embodiment, and a narrowing portion 39 is formed at the trailing edge to enhance the negative pressure maintaining effect. In addition, utilizing the multiple structure of the surrounding cylinder 20, the outside air introduced from the air introduction port 40 on the front is taken into the internal space 24 from the ventilation hole 41 formed in the innermost cylinder 29-1, and the high speed with the exhaust gas flow is obtained. By causing agitation, the temperature of the exhaust stream can be reduced. Other configurations may be the same as those of the second embodiment.

The apparatus of the present invention having such a configuration is as follows.
For example, in the case of an automobile engine 40, a load resistance such as a catalyst device 41 or a muffling device 42 may be provided between the exhaust system and the exhaust system in connection with the exhaust system pipe 11. However, this also has the advantage of being extremely easy to install. Engine 4
When the exhaust gas flow discharged from the 0 combustion chamber 43 reaches the present apparatus with the flow velocity lowered by the load resistance and reaches the present apparatus, it is accelerated to the limit in the acceleration part A, approaches the discharge speed from the cylinder, and at the same time, A strong negative pressure is generated in a wide area 31. Due to this negative pressure, a part of the exhaust gas flow before acceleration is sucked through the through hole 15, bypasses and merges with the accelerated exhaust flow at the exhaust pipe upstream, diffusely flows out as a high-speed exhaust flow, and is released to the atmosphere. Is as described above. As a result, the exhaust gas is dragged at a high speed, and the speed of the entire exhaust system is increased to reach the exhaust port of the cylinder, so that the combustion gas in the combustion chamber is quickly sucked and discharged at the exhaust timing and replaced with fresh air. Becomes That is, scavenging can be extremely promoted.

[0021]

According to the present invention having the above-described contents, a high negative pressure is generated in a larger amount as compared with the conventional apparatus, and the annular pressure is increased in accordance with the high acceleration of the exhaust gas flow. The clearance can be maintained, so that even if the engine displacement is somewhat large or small, it is sufficiently possible to cope with it by one kind of the present apparatus. Therefore, there is an effect that the engine can be provided with a smaller number of product types and with a wider variety of engines, and can be used more easily and at a lower cost.

[Brief description of the drawings]

FIG. 1 is a sectional view showing a first embodiment of a scavenging promoting device according to the present invention.

FIG. 2 is a sectional view showing Embodiment 2 of the scavenging promoting device according to the present invention.

FIG. 3 is a sectional view showing Embodiment 3 of the scavenging promoting device according to the present invention.

FIG. 4 is a sectional view showing Embodiment 4 of the scavenging promoting device according to the present invention.

FIG. 5 is a side view for explaining an example of installation of the device and an operation thereof.

Claims (4)

[Claims] An apparatus for promoting scavenging by accelerating the flow rate of an exhaust gas flow reduced by the resistance of an exhaust system to discharge the exhaust gas to the atmosphere, and having one end connected to an exhaust system pipe Has an exhaust gas injection port at the other end, and is formed in a tapered shape in which the cross-sectional area of the flow path gradually decreases for acceleration of the exhaust gas flow from one end to the other end. An accelerating cylinder having a through-hole that opens to the outside on the peripheral surface, and one end coupled to the accelerating cylinder upstream of the through-hole, the other end surrounding the injection port of the accelerating cylinder and forming an annular gap therebetween, An enclosure that allows the exhaust gas flow to flow out through the annular gap and through-hole due to the negative pressure generated by the acceleration of the exhaust flow, and discharges the accelerated exhaust flow injected from the injection port and the suction exhaust flow flowing out of the annular gap to the atmosphere. An exhaust pipe connected to the other end opening of the enclosure. A scavenging accelerating device having a configuration in which the length of the exhaust cylinder is set to a length at which the exhaust gas flowing downstream from the injection port can contact the exhaust cylinder. 2. An accelerating cylinder having a tapered shape, wherein a scavenging is promoted by accelerating a flow velocity of an exhaust gas flow reduced by resistance of an exhaust system to discharge exhaust gas to the atmosphere, and comprising: An enclosure which is disposed on the outside, and an exhaust cylinder for venting an accelerated exhaust stream accelerated by the acceleration cylinder and a suction exhaust stream flowing out from an annular gap between the enclosure and the enclosure. 2. The scavenging promoting device according to 1. 3. A cooling cylinder surrounding the exhaust cylinder and having an end protruding rearward from a trailing edge of the cooling cylinder is provided outside the exhaust cylinder, and outside air is introduced into the outer periphery of the exhaust cylinder through a pore formed in the cooling cylinder. Item 4. The scavenging promoting device according to Item 1. 4. The scavenging accelerating device according to claim 2, wherein outside air taken in from an inlet for introducing outside air into the enclosure is introduced between the acceleration cylinder and the enclosure to generate a suction exhaust flow and high-speed stirring. .