JPH0121126Y2 - - Google Patents

Description

[Detailed Description of the Invention] The present invention relates to a muffler for an agricultural engine that is suitable for installation in a narrow engine room.

BACKGROUND ART Conventionally, in the field of agricultural machinery and the like, it has been proposed that the muffler is formed into a so-called direct-mounted muffler that is directly attached to the engine without a long exhaust pipe, and the muffler body is installed in the engine room. However, conventional direct mufflers are often formed in a cylindrical or oval cylindrical shape.
Because the muffler outer cylinder tends to interfere with the engine part, it is difficult to place it in a narrow engine room. A flat rectangular type muffler has also been considered, but since the internal partition wall is formed from a straight plate, there are design problems such as the muffler mounting bolts getting in the way of the partition wall. Not, but
In order to improve the flow of exhaust gas in the muffler, it is necessary to increase the volume of the second chamber so that the area through which the exhaust gas flows from the first chamber to the second chamber is large.

The present invention was developed based on the above-mentioned circumstances, and its purpose is to attach the muffler body formed in a rectangular shape directly to the engine so that the inside of the muffler body faces the exhaust port from the engine. The first chamber is separated from the second chamber through a partition wall that sequentially guides exhaust gas from the first chamber to the tail pipe side, and at least the portion of the partition wall that partitions the first chamber and the second chamber is moved downward. A sloped part is provided between the first chamber and the second chamber, and a guide plate is placed on the partition wall, facing in front of the exhaust port at a predetermined distance w, and with a gap above the sloped part. The left and right ends of the guide plate are integrally connected to the left and right side plates of the muffler, respectively, and a large number of ventilation holes are provided in the sloped parts, thereby making the muffler body as small as possible. Although it can be made flat and can be installed compactly in the narrow space of the engine room, it is also possible to set the passage area of the exhaust gas from the first chamber to the second chamber as large as possible, thereby improving the overall exhaust flow. It is an object of the present invention to provide a muffler for an engine for agricultural machinery, which can achieve good noise reduction effects and high-temperature heat generation prevention effects.

To explain the configuration of the present invention with reference to an embodiment shown in the drawings, FIG. 1 shows an engine main body 1 for agricultural machinery.
The figure shows the internal structure of an engine room with a built-in engine, in which 2 is a flywheel, 3 is an engine pulley, and 4a, 4b, and 4c are drive belts, respectively. The engine body 1 is fixed to a vibration isolating rubber 6 set on a body frame 5 via a fixing frame 7 and nuts 8. Reference numeral 9 denotes a rod fixed to the fixing plate 7 or the engine body 1, one end of which is extended to the vicinity of the outer end of the engine pulley 3, and the extended end side is connected to the fuselage frame 5 with a bolt 10.
It is fitted into a pipe-shaped rubber 12 housed in a fixed holder 11, and is constructed so that the pipe-shaped rubber 12 near the load point of the engine pulley 3 can completely prevent twisting of the engine due to a belt clutch, etc. ing.

13 is a rectangular muffler directly attached to the engine body 1 via a short manifold block 14 and mounting bolts 15; 16 is a mounting reinforcement plate; 16'
1 is a mounting pipe, and 17 is a heat shield cover for the muffler 13. 18 is a partition wall, and the inside of the muffler 13 is divided into a first chamber a which faces the exhaust port 19 from the engine body 1, and a second chamber a which sequentially guides exhaust gas from the first chamber to the tail pipe 20 side. room b
The subsequent chambers (third chamber c, fourth chamber d) are separated. 21 is a separation plate between the second chamber b and third chamber c, 22 is a separation plate between the third chamber c and fourth chamber d, and these separation plates 2
1 and 22 are provided with a plurality of ventilation holes 21' and 22', respectively. Note that these separation plates 21, 2
In No. 2, the aperture ratio is adjusted to the optimum state by adjusting the hole diameter, number of holes, etc., in order to obtain a good sound deadening effect.

By the way, the partition wall 18 is as shown in FIG.
The left and right sides, that is, the second chamber b and the fourth chamber d, are each formed in a downwardly inclined chevron shape, and the second chamber b
A large number of ventilation holes 18'a are provided in the side inclined portion 18a.

Reference numeral 23 denotes an exhaust pipe provided at one end of the lower part of the muffler 13, which communicates and connects the fourth chamber d and the tail pipe 20.

Incidentally, the inclined part 18b on the fourth chamber d side is for improving exhaust air since the tail pipe 20 is extended downward, and when the tail pipe 20 is extended laterally, this inclined part 18b may be omitted. good.

Reference numeral 24 denotes a guide plate erected and fixed on the partition wall 18 in front of the exhaust port 19, facing each other at a predetermined interval W, and with a gap A on the inclined parts 18a and 18b. The first chamber a is opened by the plate 24.
The lower side of the chamber is divided into an anterior chamber B and a rear chamber C.
The left and right ends of the guide plate 24 are integrally connected to the left and right side plates of the muffler 13 by welding or the like, and the integral structure of the partition wall 18, the guide plate 24, and the muffler side plates further increases the overall strength of the muffler 13. It has a structure. A sound-absorbing material 25' such as glass wool is filled between the perforated plate 26 fixed above the first chamber a and the top plate 13' of the muffler 13, and a sound-absorbing wall 25 is formed in this area.

In the configuration as described above, the high-temperature expansion pressure gas exhausted from the engine body 1 after completion of combustion enters the first chamber a of the muffler 13 as indicated by the arrow in FIG. 24. Then, the direction changes downward while hitting the sound deadening wall 25 and attenuating the sound wave energy. At this time, the downward exhaust gas is
The sonic energy is further reduced by interfering with the subsequent hot turgor gas rising along 4. Incidentally, the downward exhaust gas is guided toward the inclined portion 18a of the partition wall 18 in a state where the first chamber a is divided into a front chamber B and a rear chamber C back and forth by the guide plate 24, and is guided to the gap above the inclined portion 18a. As the sound waves of the branched exhaust gas join together at the point A, the sound wave energy is further attenuated by the amount of the opposite phase wave. ,... into the second chamber b, and then through the ventilation holes 21', 21', of the separation plate 21.
...and further into the third chamber c through the ventilation hole 2 of the separation plate 22.
After passing through 2', 22', etc., and being guided to the fourth chamber d, the gas enters the tail pipe 20 via the exhaust pipe 23, and is discharged from its extending end to the outside of the engine room. During the series of exhaust gas movement steps described above, the exhaust gas is gradually muffled as it passes through each chamber a, b, c, and d.

By the way, in the present invention, the partition wall 18 in the muffler 13 is formed in the shape of a mountain with both left and right sides inclined downward, and a large number of ventilation holes 18'a are formed in the inclined part 18a that partitions the first chamber a and the second chamber b. Because it was established,
The area through which the exhaust gas passes from the first chamber to the second chamber b is increased, and the inclined portion 18a also serves as a guide for the exhaust gas, so that the flow of the exhaust gas is maintained at a smooth flow without sudden changes. Therefore, there is no need to set the capacity of the second chamber b particularly large as in the conventional case, and the entire muffler 13 can be made as small and flat as possible.

By achieving this compact and flat design, even though it is a direct muffler, it can be compactly installed in a narrow space without interfering with the engine.

In addition, since the inclined portion 18b serves as a guide for the exhaust outlet side in the muffler 13, the exhaust gas in the fourth chamber d can flow smoothly and quickly toward the tail pipe 20. Furthermore, since the muffler body 13 is formed into a rectangular parallelepiped It is easy to process, and together with the fact that it is formed into a directly mounted muffler without using a long exhaust pipe, further cost reductions can be achieved. In addition,
By slanting both sides of the partition wall 18, the partition wall 18 can be mounted while allowing the mounting bolts 5 to escape, which facilitates machining. Furthermore, since the guide plate 24 is provided in the first chamber a facing the exhaust port 19, the high temperature exhaust gas does not directly hit the outer wall of the muffler, thereby preventing the outer wall of the muffler from becoming hot as much as possible. .

As mentioned above, in this invention, a muffler body formed in a rectangular shape is directly attached to the engine, and the first chamber faces the exhaust port from the engine inside the muffler body, and the first chamber sequentially exhausts the air to the tail pipe side. The second and subsequent chambers that guide the gas are separated via a partition wall, and at least the portion of the partition wall that partitions the first and second chambers is inclined downward to create a space between the first and second chambers. A sloped portion is provided, and a guide plate is fixed upright on the partition wall with a predetermined interval w in front of the exhaust port facing each other, and a gap is provided above the sloped portion. Since the end portions are integrally connected to the left and right side plates of the muffler, and a large number of ventilation holes are provided in the inclined portion, the muffler main body can be made as small and flat as possible, and can be installed compactly in the narrow space of the engine room. However, the flow of exhaust gas that has entered the first chamber of the muffler from the exhaust port can be effectively controlled by the guide plate in the process of reaching the second chamber, so the flow of exhaust gas from the first chamber can be effectively controlled. This not only makes it possible to attenuate the sonic energy of the exhaust gas as much as possible, but also increases the passage area of the exhaust gas from the first chamber to the second chamber, improving the overall flow of the exhaust gas. In addition to being able to achieve good silencing effects and high-temperature heat generation prevention effects, it is easy to process and can reduce costs.Moreover, it has the advantage of further increasing the overall strength of the muffler with the guide plate. .

[Brief explanation of drawings]

Figure 1 is a partially cutaway side view of the engine room equipped with the present invention, Figure 2 is a front view showing the engine support structure, Figure 3 is an enlarged front view of a portion of Figure 2, and Figure 4 is a partially cutaway side view of the engine room equipped with the present invention. 5 is a sectional view taken along the line A--A in FIG. 4, and FIG. 6 is a view taken along arrow B in FIG. 4. In the figure, 1 is the engine, 13 is the muffler body, 18
is a partition wall, 18a is a slope, 18'a is a ventilation hole,
19 is the exhaust port, c is the first chamber, b is the second chamber, c is the third chamber, d is the fourth chamber, and a is the gap.

Claims (1)

[Scope of utility model registration request] A rectangular muffler body is mounted directly on the engine, and the first chamber faces the exhaust port from the engine inside the muffler body, and the second and subsequent chambers guide exhaust gas from the first chamber to the tailpipe side sequentially. The chambers are separated via a partition wall, and at least a portion of the partition wall that partitions the first chamber and the second chamber is sloped downward to provide an inclined portion between the first chamber and the second chamber, and a slope is provided between the first chamber and the second chamber. In this case, a guide plate is fixed upright in front of the exhaust port with a predetermined interval w and facing each other and with a gap on the slope, and the left and right end sides of the guide plate are placed in the left and right sides of the muffler, respectively. 1. A muffler for an agricultural machinery engine, characterized in that the muffler is integrally connected to a side plate of the engine, and has a number of ventilation holes provided in the inclined portion.