CN221896673U - An engine back pressure exhaust muffler for unmanned aerial vehicle - Google Patents

Abstract

The utility model discloses an engine back pressure exhaust silencer of an unmanned aerial vehicle, which comprises an air inlet section, a back pressure bag and a silencer which are sequentially connected, wherein the silencer comprises a shell, one end of the shell is provided with a front sealing plate, the other end of the shell is provided with a tail sealing plate, and an air outlet of the back pressure bag extends into the shell and is fixed on the front sealing plate; a tail pipe is arranged on the tail sealing plate, and a plurality of first small holes are uniformly distributed on the part of the tail pipe extending into the shell; the back pressure bag is added at the front end of the silencer, waste gas is pumped out and mixed gas is sent back to the engine, so that the air inlet efficiency of the engine is improved, meanwhile, the tail pipe is arranged in the shell of the silencer, a plurality of first small holes are formed in the air inlet end of the tail pipe for air inlet and exhaust, and therefore the pressure is released through the inner cavity of the shell, and the tail pipe is used for accelerating the exhaust, so that the exhaust noise can be greatly reduced.

Description

An engine back pressure exhaust muffler for unmanned aerial vehicle

Technical Field

The utility model relates to the technical field of exhaust silencing for unmanned aerial vehicles, and in particular to an engine back-pressure exhaust silencer for unmanned aerial vehicles.

Background Art

The engine is the main component of the UAV. The engine generally used is a two-stroke engine. The engine will produce exhaust emissions and noise during operation. Due to the intake and exhaust characteristics of the two-stroke engine, some of the new mixture entering the cylinder will enter the exhaust pipe from the exhaust port during exhaust, which will reduce the engine's intake efficiency.

It is necessary to reduce the noise when the engine discharges exhaust gas and to reflux the mixed gas entering the exhaust pipe.

Utility Model Content

1. Technical issues

The utility model aims to provide an engine back-pressure exhaust muffler for a drone, which solves the problem of significantly reducing the noise when exhaust gas of a two-stroke engine is discharged and improving the intake efficiency.

(II) Technical solution

In order to achieve the above purpose, the utility model provides the following technical solutions:

An engine back-pressure exhaust silencer for an unmanned aerial vehicle comprises an air intake section, a back-pressure bag and a silencer connected in sequence, the silencer comprising an outer shell, one end of the outer shell being provided with a front sealing plate, the other end of the outer shell being provided with a rear sealing plate, an air outlet of the back-pressure bag extending into the outer shell and being fixed to the front sealing plate; a tail pipe is mounted on the rear sealing plate, and a plurality of first small holes are evenly distributed on the portion of the tail pipe extending into the outer shell.

Preferably, a first partition and a second partition are provided in the shell, and through holes are provided on the first partition and the second partition; and the air outlet of the back pressure bag passes through the through holes of the first partition.

Preferably, the back pressure bag comprises a first diffuser, a second diffuser and a shrinkage tube which are connected in sequence, and the air inlet of the first diffuser is provided with a first flange; the diameters of the second diffuser and the first diffuser gradually increase, and the diameter of the shrinkage tube gradually decreases.

Preferably, a plurality of second small holes are formed on the shrink tube at a location between the front sealing plate and the first partition plate.

Preferably, the air intake section comprises an air intake pipe, the air intake port of the air intake pipe is provided with a connecting flange, and the air outlet of the air intake pipe is provided with a second flange.

Preferably, the air inlet pipe is a bent structure.

(III) Beneficial effects

By adding a back-pressure bag at the front end of the muffler, the exhaust gas can be extracted and the mixed gas can be sent back to the engine, thereby improving the engine's intake efficiency. At the same time, a tail pipe is arranged inside the outer shell of the muffler, and a plurality of first small holes are arranged at the air inlet end of the tail pipe to intake and discharge air. After the pressure is released through the inner cavity of the outer shell, the exhaust is accelerated through the tail pipe, thereby greatly reducing the exhaust noise.

BRIEF DESCRIPTION OF THE DRAWINGS

FIG1 is a schematic structural diagram of an embodiment of the utility model;

FIG2 is a schematic structural diagram of the assembly of the back pressure bag and the muffler in an embodiment of the utility model;

FIG3 is a schematic structural diagram of an air intake section in an embodiment of the present utility model;

FIG4 is a schematic diagram of the structure of a back pressure bag in an embodiment of the utility model;

In Figures 1 to 4, the corresponding relationship between component names or lines and figure numbers is as follows:

Intake section 1, connecting flange 101, intake pipe 102, second flange 103, back pressure bag 2, first flange 201, first diffuser 202, second diffuser 203, contraction tube 204, muffler 3, front sealing plate 301, first partition 302, outer shell 303, second partition 304, tail pipe 305, tail sealing plate 306.

DETAILED DESCRIPTION

The technical solutions in the embodiments of the present invention will be described clearly and completely below in conjunction with the drawings in the embodiments of the present invention. Obviously, the described embodiments are only part of the embodiments of the present invention, rather than all of the embodiments.

Referring to Figures 1 to 4, an embodiment of the utility model provides an engine back-pressure exhaust muffler for an unmanned aerial vehicle, comprising an intake section 1, a back-pressure bag 2 and a muffler 3 connected in sequence. The back-pressure bag 2 is added to extract the exhaust gas during the engine exhaust process and send the mixed gas back to the engine, thereby improving the intake efficiency of the two-stroke engine and improving the engine power. At the same time, noise reduction is performed by the muffler 3. Specifically, the muffler 3 includes a shell 303, one end of the shell 303 is provided with a front sealing plate 301, the other end of the shell 303 is provided with a tail sealing plate 306, the air outlet of the back pressure bag 2 extends into the shell 303 and is fixed on the front sealing plate 301, and a tail pipe 305 is installed on the tail sealing plate 306, and a plurality of first small holes are evenly distributed on the portion of the tail pipe 305 extending into the shell 303; the exhaust gas from the back pressure bag 2 enters the shell 303 and is depressurized, thereby reducing the noise after the exhaust gas enters the shell 303, and the plurality of small holes on the tail pipe 305 are used to disperse the exhaust gas to further reduce the exhaust noise.

Specifically, a first partition plate 302 and a second partition plate 304 are provided in the outer shell 303, and through holes are provided on the first partition plate 302 and the second partition plate 304, wherein the air outlet of the back pressure bag 2 passes through the through holes of the first partition plate 302; after adding the first partition plate 302 and the second partition plate 304 in the outer shell 303, the airflow entering the outer shell 303 can be further decelerated, thereby improving the noise reduction effect.

The back-pressure package 2 uses the resonant beam wave back-pressure principle to extract the exhaust gas and return the mixed gas to the engine. The back-pressure package 2 includes a first diffuser 202, a second diffuser 203 and a contraction tube 204 connected in sequence. The air inlet of the first diffuser 202 is provided with a first flange 201, wherein the diameters of the second diffuser 203 and the first diffuser 202 gradually increase, and the diameter of the contraction tube 204 gradually decreases; the back-pressure package 2 is connected to the air intake section 1 through the first flange 201, and the resonant beam wave back-pressure is realized by utilizing the changes in the diameters of the first diffuser 202, the second diffuser 203 and the contraction tube 204 to separate the exhaust gas and the mixed gas and discharge the exhaust gas, while the mixed gas flows back into the engine.

At the same time, a plurality of second small holes are opened on the shrink tube 204 at a position between the front sealing plate 301 and the first partition plate 302. When the back pressure bag 2 discharges the exhaust gas into the muffler 3, the second small holes are used to disperse the flow to further reduce noise, and the arrangement of the second small holes is a non-uniform arrangement.

Specifically, the intake section 1 includes an intake pipe 102, the air inlet of the intake pipe 102 is provided with a connecting flange 101, and the air outlet of the intake pipe 102 is provided with a second flange 103, wherein the intake pipe 102 is a bent structure; the noise reduction of the exhaust and intake process is achieved by the intake pipe 102 with a bent structure, and at the same time, the intake pipe 102 is installed on the engine by using the connecting flange 101, and the connection between the back pressure bag 2 and the intake section 1 is achieved by the cooperation of the second flange 103 and the first flange 201.

In the present invention, unless otherwise clearly specified and limited, the terms "install", "connect", "connect", "fix" and the like should be understood in a broad sense, for example, it can be a fixed connection, a detachable connection, or an integral connection; it can be a mechanical connection or an electrical connection; it can be a direct connection or an indirect connection through an intermediate medium, it can be the internal connection of two elements or the interaction relationship between two elements. For ordinary technicians in this field, the specific meanings of the above terms in the present invention can be understood according to specific circumstances.

In the description of the present utility model, it should be noted that the terms "center", "upper", "lower", "left", "right", "inner", "outer", etc. indicate the orientation or position relationship based on the orientation or position relationship shown in the drawings, or the orientation or position relationship in which the utility model product is usually placed when in use, which is only for the convenience of describing the utility model and simplifying the description, and does not indicate or imply that the device or element referred to must have a specific orientation, be constructed and operated in a specific orientation, and therefore cannot be understood as a limitation on the present utility model. In addition, the terms "first", "second", etc. are only used to distinguish the description, and cannot be understood as indicating or implying relative importance.

It is obvious to those skilled in the art that the present invention is not limited to the details of the exemplary embodiments described above, and that the present invention can be implemented in other specific forms without departing from the spirit or essential features of the present invention. Therefore, the embodiments should be regarded as exemplary and non-restrictive from any point of view, and the scope of the present invention is defined by the appended claims rather than the above description, and it is intended that all changes falling within the meaning and scope of the equivalent elements of the claims be included in the present invention. Any reference numeral in a claim should not be regarded as limiting the claim to which it relates.

Claims (6)

1. An engine back pressure exhaust muffler for a drone, characterized in that it comprises an air intake section, a back pressure bag and a muffler connected in sequence, the muffler comprises a shell, one end of the shell is provided with a front sealing plate, the other end of the shell is provided with a rear sealing plate, the air outlet of the back pressure bag extends into the shell and is fixed to the front sealing plate; A tail pipe is installed on the tail sealing plate, and a plurality of first small holes are evenly distributed on the portion where the tail pipe extends into the shell. 2. The engine back pressure exhaust muffler of a drone according to claim 1, characterized in that: a first partition plate and a second partition plate are provided in the shell, and through holes are provided on the first partition plate and the second partition plate; The air outlet of the back-pressure bag passes through the through hole of the first partition plate. 3. The engine back pressure exhaust silencer of a UAV according to claim 2, characterized in that: the back pressure pack comprises a first diffuser, a second diffuser and a contraction tube connected in sequence, and the air inlet of the first diffuser is provided with a first flange; The diameters of the second diffuser tube and the first diffuser tube gradually increase, and the diameter of the shrinkage tube gradually decreases. 4. An engine back-pressure exhaust muffler for an unmanned aerial vehicle according to claim 3, characterized in that a plurality of second small holes are provided on the shrink tube at a position between the front sealing plate and the first partition plate. 5. An engine back-pressure exhaust silencer for an unmanned aerial vehicle according to claim 4, characterized in that: the air intake section comprises an air intake pipe, the air intake of the air intake pipe is provided with a connecting flange, and the air outlet of the air intake pipe is provided with a second flange. 6. The engine back-pressure exhaust muffler of a UAV according to claim 5, characterized in that the air intake pipe is a bent structure.