WO2007142181A1

WO2007142181A1 - Muffler

Info

Publication number: WO2007142181A1
Application number: PCT/JP2007/061276
Authority: WO
Inventors: Buhei Kobayashi; Ryou Ono
Original assignee: Husqvarna Zenoah Co., Ltd.
Priority date: 2006-06-08
Filing date: 2007-06-04
Publication date: 2007-12-13
Also published as: JP2007327420A; TW200809079A

Abstract

A muffler for a small two-cycle engine comprises a muffler body having an expansion chamber, an exhaust gas guide member (21) for covering an exhaust gas feed port formed in the muffler body, and a cover hood (22) for covering an exhaust gas discharge port formed in the exhaust gas guide member. An attachment (20) is structured by integrating the exhaust gas guide member (21) with the cover hood (22). The attachment (20) can be so slid in relative to the muffler body that the attachment is capable of freely engaging with or disengaging from the muffler body.

Description

Specification

Scarf

Technical field

TECHNICAL FIELD [0001] The present invention relates to a muffler and relates to a muffler for a small engine mounted on a portable work machine such as a blower, a chain saw, a cut-off saw, or a brush cutter.

Background art

Conventionally, an engine blower, a chain saw, and the like are known as portable working machines driven by an engine. The engine of such a portable work machine is driven at a position relatively close to the worker, and the exhaust gas temperature from the muffler may be regulated because it is necessary to consider the surrounding environment. Emission is desired. Specifically, the exhaust gas temperature from the engine cover that covers the engine and muffler is regulated.

[0003] As a method for lowering the temperature of exhaust gas emitted from a muffler, for example, it has been proposed to reduce the temperature by taking in outside air by a jet of exhaust gas and mixing the exhaust gas and outside air (for example, patents) Reference 1). Specifically, an exhaust gas guide member for discharging the exhaust gas of the muffler body force in a predetermined direction is provided on the surface of the muffler body, and the exhaust gas guide member is covered with a cover hood. Exhaust gas guide member force Due to the ejector effect of the discharged exhaust gas, the outside air is taken into the cover hood, and the outside air and the exhaust gas are mixed to reduce the exhaust gas temperature.

[0004] Patent Document 1: JP-A-53-44998

Disclosure of the invention

Problems to be solved by the invention

[0005] However, in Patent Document 1, the cover hood necessary for taking in outside air is fixed to the muffler body by caulking, and the exhaust gas guide member is welded to the muffler main body by welding or the like. Since it is fixed, it is difficult to remove the cover hood easily to remove the muffler body force to clean the exhaust gas guide member, or to remove the muffler body force exhaust gas guide member to clean the inside. There was a problem.

[0006] Further, such an exhaust gas guide member cover hood is attached to a muffler book with a screw or the like. Force that can be detachably attached to the body It also takes time to remove and reattach the screws one by one. In addition, when the exhaust gas guide member and the cover hood are attached with separate screws, the number of force screws that are effective in terms of secure fixation increases, so that quick attachment / detachment cannot be performed.

[0007] An object of the present invention is to provide a muffler in which an exhaust gas guide member and a cover hood such as a cover hood can be easily attached and detached and the maintainability can be improved.

Means for solving the problem

[0008] The muffler of the present invention includes a muffler body having an expansion chamber, an exhaust gas guide member that covers an exhaust gas outlet provided in the muffler body, and a cover hood that covers an exhaust gas outlet side of the exhaust gas guide member The exhaust gas guide member and the cover hood are integrated to form an attachment, and the attachment has an insertion portion that is detachably inserted into a fitting portion provided in the muffler body. It is characterized by having it.

[0009] According to the present invention, the exhaust gas guide member and the cover hood are integrated to form the attachment, and the attachment is provided with the insertion portion. By sliding the attachment in a predetermined direction, the muffler body The exhaust gas guide member and the cover hood can be attached to and detached from the fitting portion at the same time, and the maintainability can be improved. In addition, even if the attachment is finally fixed to the muffler body using screws, the number of screws can be minimized, and there is no concern about hindering easy attachment / detachment.

[0010] In the muffler of the present invention, each of the exhaust gas guide member and the cover hood is provided with a mounting piece that is overlapped and fixed, and the mounting piece engages with the muffler body. It is preferable to have a joint section.

[0011] According to the present invention, the exhaust gas guide member and the cover hood are integrally formed by fixing the attachment pieces provided to each other, and the attachment piece portions are doubled to increase the strength. Therefore, by providing the engagement portion in such a double portion, the engagement with the muffler body can be performed firmly.

Brief Description of Drawings

FIG. 1 is an overall perspective view showing a muffler according to a first embodiment of the present invention. FIG. 2 is a cross-sectional view of the muffler shown in FIG.

FIG. 3 is a cross-sectional view of the muffler shown in FIG.

FIG. 4 is an enlarged plan view showing the attachment of the muffler.

[FIG. 5] A view of the attachment shown in FIG.

[Fig. 6] A view of the attachment shown in Fig. 4 as seen from the rear side.

FIG. 7 is a view showing an attachment according to a second embodiment of the present invention.

Explanation of symbols

[0013] 1 ... muffler, 2 ... expansion chamber, 10 ... muffler body, 12A ... outlet, 20 ... attachment, 21 ... exhaust gas guide member, 22 ... cover hood, 23A ... discharge port, 23C, 24C ... Mounting piece, 25... Engaging portion, 26.

BEST MODE FOR CARRYING OUT THE INVENTION

[First Embodiment]

Hereinafter, a first embodiment of the present invention will be described with reference to the drawings.

FIG. 1 is an overall perspective view showing the muffler 1 according to the present embodiment. FIG. 2 is a cross-sectional view of the muffler 1 shown in FIG. 3 is a cross-sectional view of the muffler 1 shown in FIG. FIG. 4 is an enlarged plan view showing the attachment 20 of the muffler 1. FIG. 5 is a view of the attachment 20 shown in FIG. 4 as viewed from the front side, and FIG. 6 is a view as seen from the rear side. In the present specification, the front side refers to the front side in the flow direction of the exhaust gas, and the rear side refers to the rear side in the flow direction of the exhaust gas.

The muffler 1 of the present embodiment is for a small two-cycle engine mounted on an engine blower (not shown), and has a box-like muffler body 10 in which an expansion chamber 2 is formed, and an outer surface of the muffler body 10 And an attachment 20 attached thereto.

[0016] The muffler body 10 includes a base cover 11 having an introduction port 11A into which exhaust gas from the engine side is introduced, and a cover member 12 is attached to the base cover 11 by caulking at the peripheral portion. A baffle 13 having a plurality of round holes 13A is provided inside the inlet 11A. After the exhaust gas having entered the inlet 11A hits the opposite surface 13B of the baffle 13, each round hole 13A Spreads in expansion chamber 2 while dispersing force. The back side of the cover member 1 2 has a double structure, and a sound deadening material 14 is arranged inside it. Yes.

[0017] Further, the cover member 12 is provided with an outlet 12A for sending exhaust gas. Each of the outlet 12A and the aforementioned inlet 11A is provided at a position where it does not overlap in the thickness direction of the muffler body 10. One end of the tail pipe 15 is fixed to the delivery port 12A via a bracket 15A.

[0018] Further, the cover member 12 is provided with a pair of bolt insertion holes 12B, and the base force bar 11 is provided with a communication hole (not shown) corresponding to each insertion hole 12B. The insertion hole 12B and the communication hole communicate with each other through a guide pipe 17 in the muffler main body 10, and the muffler 1 is bolted to the engine by a bolt threaded through the guide pipe 17.

[0019] The attachment 20 includes an exhaust gas guide member 21 covering the delivery port 12A, and the exhaust gas guide member.

A cover hood 22 that covers 21 is provided integrally. The exhaust gas guide member 21 is provided with a guide part 23 bulging upward, and a discharge port 23A is provided on one end side of the guide part 23.

[0020] At the periphery of the guide portion 23, a flange-like insertion portion 23B is provided. A mounting piece 23C continuous with the insertion portion 23B is provided on the front side of the discharge port 23A. In the same plane of the mounting piece 23C, the portion immediately before the discharge port 23A is an opening 23D.

[0021] The cover hood 22 includes an outlet 23A and an outside air mixing unit 24 that covers the front side thereof. On the rear side of the outside air mixing unit 24, a fixed piece 24A having a tip fixed to the upper surface of the guide unit 23 is extended. The gap between the outside air mixing unit 24 and the guide unit 23 becomes an outside air introduction gap 24B for introducing outside air into the outside air mixing unit 24.

[0022] On both sides of the outside air mixing section 24, mounting pieces 24C having the same shape as the mounting pieces 23C of the guide section 23 are provided, and the mounting pieces 23C, 24C are fixed to each other by spot welding or the like. Such attachment pieces 23C, 24C are provided with semi-elliptical engagement portions 25 that are open to the rear side.

[0023] On the front end side of the outside air mixing unit 24, an exhaust port 24D for exhausting the exhaust gas after the outside air mixing is provided. On the upper edge of the exhaust port 24D, there is provided a projecting piece 24E that is bent toward the center in the in-plane direction of the opening. The position of the projecting piece 24E is not limited to the upper edge as long as the projecting piece 24E is provided in the vicinity of the exhaust port 24D so as to close the exhaust port 24D. Ma In the middle of the outside air mixing portion 24, a reduced diameter portion 24F having a cross-sectional area that decreases toward the front side is provided. On the upper surface of the reduced diameter portion 24F, a recess 24G that is recessed inward is provided. ing.

[0024] In such an attachment 20, the exhaust gas guide member 21 and the cover hood 22 are integrated in advance, and the insertion portion 23B is provided on the mounting surface 12C on the surface of the cover member 12 by sliding from the front side to the rear side. The mating part 18 is inserted and fitted, and each engaging part 25 force S is engaged with the screw 19 temporarily fixed to the cover member 12, and is fixed to the muffler body 10 by tightening this screw 19. Is done. At this time, the spark arrester 16 is disposed inside the exhaust gas guide member 21 in a state of protruding from the head part discharge port 23A.

[0025] Further, the tip of the cover hood 22 protrudes from the side surface of the muffler main body 10, and the exhaust port 24D force is also exhausted into the side surface of the exhaust gas so that the generation of vortex is suppressed and directed outward. And flow in a straight line. At this time, the projecting piece 24E has a function of exhausting the exhaust gas of the exhaust outlet 24D force in a concave shape when viewed from the front, thereby increasing the area of the exhaust gas in contact with the outside air and further reducing the exhaust gas temperature. Is possible.

[0026] Hereinafter, the flow of exhaust gas will be described with reference to FIG.

Inlet 11A (Fig. 2) The exhaust gas that has also entered the expansion chamber 2 is sent into the exhaust gas guide member 21 through the tail pipe 15, and is discharged from the exhaust port 23A of the exhaust gas guide member 21 into the cover hood 22. . At this time, the exhaust gas from the discharge port 23A is gradually expanded to the top surface 24H side of the cover hood 22 according to the direction force on the front end side of the flow direction of the exhaust gas S in the cross-sectional shape of the guide 23 Then, it spouts to spread while facing the top surface 24H.

[0027] Then, due to the ejector effect when the exhaust gas is ejected from the discharge port 23A, the external air force S through the external air introduction gap 24B formed between the exhaust gas internal member 21 and the cover hood 22 It is introduced into the outside air mixing unit 24. In the outside air mixing section 24, the discharged exhaust gas and the introduced outside air are mixed and mixed, and the mixed exhaust gas is cooled and the exhaust port 24D force is also exhausted.

[0028] On the other hand, if the muffler 1 is used for a long time and the spark arrester 16 becomes clogged or the internal tail pipe 15 becomes clogged, remove the attachment 20 from the muffler body 10 and clean it. There is a need to do. In this case, loosen the two screws 19 Remove the entire attachment 20 by pulling it forward. By doing so, the spark arrester 16 may be removed and cleaned, and the exposed outlet 23A and tail pipe 15 may be cleaned with a brush or the like. After cleaning, slide the attachment 20 and insert and fit the insertion part 23B into the fitting part 18, engage the engaging part 25 with the screw 19, and retighten the screw 19!

[0029] As described above, in the attachment 20 of the muffler 1, the exhaust gas guide member 21 and the cover hood 22 are integrally provided, and can be easily attached to the muffler body 10 in a sliding manner. It can be easily removed. In this case, however, the work is simple in that it is not necessary to completely remove the screw 19. Therefore, since the attachment 20 can be easily engaged and disengaged, cleaning of the spark arrester 16 and the tail pipe 15 can be facilitated, and workability can be improved.

[0030] In addition, since the exhaust gas guide member 21 and the cover hood 22 are both fastened to the muffler main body 10 by the screw 19 and securely fixed, the attachment strength to the muffler main body 10 is also increased in this respect. Can be big. In particular, since the engaging portion 25 that engages with the screw 19 has a double structure, the screw 19 can be sufficiently tightened and can be firmly fixed.

[Second Embodiment]

FIG. 7 shows an attachment 20 according to the second embodiment of the present invention. In the attachment 20 of this embodiment, the attachment piece 23C of the exhaust gas guide member 21 is provided in a size that extends to the side of the muffler main body force not shown, whereas the attachment piece 24C of the cover hood 22 The entire length of the cover hood 22 is shortened without extending. For this reason, in the state where the attachment 20 is attached to the muffler body, the position of the exhaust port 24D is closer to the delivery port than in the first embodiment. However, even in such a case, since the mounting piece 23C extends to the side, the exhaust port 24D force is prevented from being involved in the exhausted exhaust gas, and smooth exhaust can be realized as described above.

[0032] Further, the cover hood 22 is crimped and fixed to the exhaust gas guide member 21 by the force of a pair of folded portions 241 provided on the attachment piece 23C of the exhaust gas guide member 21, and as an engaging portion. The exhaust gas guide member 21 is connected to the exhaust hole 26 by a screw not shown. Both are fastened to the muffler body. The structure in which the entire attachment 20 is fixed to the muffler main body by fitting the insertion portion 23B of the exhaust gas guide member 21 to the fitting portion 18 and screwing the screw is the same as that in the first embodiment. Further, the outside air mixing portion 24 of the cover hood 22 is the same along the flow direction of the width dimensional force exhaust gas, and there is no reduced diameter portion as in the first embodiment.

[0033] In the attachment 20 of the present embodiment, it is necessary to completely remove the two screws, but the exhaust gas guide member 21 and the cover hood 22 can be integrally engaged with and disengaged from the fitting portion 18, and these are separated. As compared with the first embodiment, the handleability can be improved, and the maintainability can be improved as in the first embodiment. Further, since the attachment 20 is securely fixed to the muffler body by tightening the screws around the through-hole 26 having a double structure, the same effect as that of the first embodiment can be obtained in terms of mounting strength. be able to.

[0034] The best configuration, method and the like for carrying out the present invention are disclosed above. 1S The present invention is not limited to this. In other words, the present invention is mainly illustrated and described mainly with respect to specific embodiments, but the technical idea and scope of the present invention does not depart from the above-described embodiments. Various modifications can be made by those skilled in the art in terms of shape, quantity, and other detailed configurations. Accordingly, the description of the shape, quantity and the like disclosed above is exemplary only for easy understanding of the present invention, and does not limit the present invention. In addition, description in the name of a member excluding some or all of the limitations such as quantity is included in the present invention.

Industrial applicability

[0035] The present invention can be suitably used as a muffler for a small engine mounted on a portable work machine such as a blower, a chain saw, a cut-off saw, or a brush cutter.

Claims

The scope of the claims

[1] A muffler body having an expansion chamber;

An exhaust gas guide member that covers an exhaust gas outlet provided in the muffler body; and a cover hood that covers an exhaust gas outlet port provided in the exhaust gas guide member, the exhaust gas guide member and the cover hood being integrated Configure the attachment,

This attachment has an insertion portion that is removably inserted into a fitting portion provided in the muffler body.

A muffler characterized by that.

[2] In the muffler according to claim 1,

Each of the exhaust gas guide member and the cover hood is provided with a mounting piece that is overlapped and fixed.

The mounting piece is provided with an engaging portion that engages with the muffler body.