JPH0544458A - Exhaust gas purifying device for outboard motor - Google Patents

Abstract

PURPOSE:To form an exhaust gas purifying device in a compact shape, to facilitate its installation, to improve exhaust gas purifying efficiency, and to increase its durability. CONSTITUTION:In an exhaust gas purifying device 18 for an outboard motor, the one side of a metallic plate 19 bent so as to have two sides forms a catalyst size 19a and the other side forms a fixing side 19b. A number of pores 21 are formed in the catalyst side 19a and catalyst carriers 24 containing a catalyst component are carried on the surface and the back. The fixing side 19b is fixed in an exhaust gas passage 15 located in the vicinity of an exhaust port 13, and one to a plurality of the catalyst sides 19a are arranged in a manner to extend in parallel to an exhaust gas flow (g) in an exhaust gas collecting chamber 15 and to stand up toward the exhaust port 13.

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to an exhaust gas purification device for an outboard motor.

[0002]

2. Description of the Related Art In an internal combustion engine for a vehicle, an exhaust purification device using a catalyst is provided for reburning unburned components contained in exhaust gas to purify and release them into the atmosphere. In an internal combustion engine of an automobile, a muffler containing a catalyst body having a catalyst component adhered to a honeycomb-shaped carrier made of ceramics is connected inside the exhaust pipe connected to the exhaust port of the internal combustion engine. When the exhaust gas passes through the exhaust gas, an oxidation reaction is caused to reburn the unburned components contained in the exhaust gas to purify the unburned components.
In a small internal combustion engine such as a motorcycle, the inner surface of the exhaust pipe connected to the exhaust port of the internal combustion engine is lined with a catalyst body in which a catalyst component is adhered to a medium such as glass wool, and is fastened with a pressing piece, and flows in the exhaust pipe. The exhaust gas is brought into contact with the catalyst body to reburn the unburned components to purify them.

[0003]

However, in the case of the catalyst body using the honeycomb-shaped carrier as described above, since the exhaust gas passes through a large number of honeycomb-shaped small holes, the flow passage area is reduced and the resistance is increased. As a result, the output of the engine is reduced, and especially in a small internal combustion engine, the performance disadvantage suffered by the reduction in output is great. Further, the catalyst body using the honeycomb carrier has a large volume and the weight thereof increases, and accordingly, the exhaust pipe itself has a large volume. On the other hand, in the case where a catalyst body made of glass wool or the like is lined on the inner peripheral surface of the exhaust pipe, its attachment is complicated, the cost is high, and the durability is also problematic.

Although it is desirable to take exhaust gas purification measures also in the outboard motor, the internal combustion engine itself of the outboard motor is small,
Moreover, since the exhaust passage is provided in a narrow space inside the drive shaft housing, the existing exhaust gas purifying device for automobiles and motorcycles cannot be applied, and even if it is applicable, the above-mentioned problems are more strongly manifested. It will be.

The present invention has been made in consideration of the above problems, and provides an outboard motor exhaust gas purification device that is compact and easy to install, has good exhaust gas purification efficiency, and at the same time has high durability. The purpose is to

[0006]

In order to achieve the above object, an exhaust gas purification apparatus for an outboard motor according to the present invention is an exhaust gas purification apparatus for an outboard motor in which a catalyst is provided in an exhaust passage of an internal combustion engine. A metal plate bent so as to have two sides has one side as a catalyst side and the other side as a fixed side. A large number of small holes are provided on the catalyst side, and a catalyst component is supported on the front and back sides of the metal plate. Fixed inside the exhaust passage near the exhaust port,
One to several catalyst sides are arranged parallel to the exhaust gas flow inside the exhaust passage and standing upright toward the exhaust port.

[0007]

With this structure, the volume of the catalyst body is reduced, the exhaust gas purification device is made very compact, and the exhaust gas purification device is easily mounted inside the exhaust passage.

Exhaust gas emitted from the exhaust port of the internal combustion engine contacts the front and back sides of the catalyst side standing upright toward the exhaust port, so that unburned components in the exhaust gas are carried on the front and back sides of the catalyst side. The exhaust gas is efficiently purified because it sufficiently contacts the catalyst component and undergoes an oxidation reaction.

Further, since the catalyst body is formed of a metal plate, high durability is imparted.

[0010]

DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS An embodiment of the present invention will be described below with reference to the drawings.

The outboard motor 1 has an internal combustion engine 4 (a two-stroke two-cylinder cylinder) covered with an engine cover 3 on an upper portion of a drive shaft housing 2 as shown in a vertical cross section in FIG. It shows the case of the engine). The reciprocating motion of the piston 6 sliding in the cylinder 5 of the internal combustion engine 4 is converted into the rotational motion of the crankshaft 8 by the connecting rod 7, and the rotation of the crankshaft 8 is transmitted to the propeller shaft 11 through the drive shaft 9.
The propeller 12 is driven to generate thrust.

The exhaust passage of the internal combustion engine 4 has an exhaust collecting chamber 15 formed by an exhaust cover 14 covering the exhaust port 13 of the cylinder 5, an exhaust pipe 16 connected to the exhaust collecting chamber 15 and extending downward, and a drive shaft. It is composed of an exhaust expansion chamber 17 formed inside the housing 2. The exhaust pipe 16 opens downward in the exhaust expansion chamber 17, and the exhaust expansion chamber 17 extends downward so that the propeller shaft 1
Along 1 there is an opening in the water.

Therefore, from the cylinder 5 to the exhaust port 13
The exhaust gas that has flowed through the exhaust gas collection chamber 15 is purified of unburned components by an exhaust purification device 18, which will be described later, and then passes through the exhaust pipe 16 into the exhaust expansion chamber 17 where it is expanded and discharged into water. It

FIG. 3 is an enlarged view of the III portion of FIG. 2, and FIG. 4 is a sectional view taken along the line IV-IV of FIG.

Exhaust gas exhaust purification system 18 according to the present invention
Is installed inside the exhaust collecting chamber 15, which is an exhaust passage near the exhaust port 13, and is composed of one to several metal plates 19 that serve as catalysts.

The metal plate 19 is bent to have two sides, one side being a catalyst side 19a and the other side being a fixed side 19b. The catalyst side 19a is wider than the fixed side 19b and is provided with a large number of small holes 21. As shown in FIG. 5 (a), non-toxic metal, ceramics, cermet or the like is sprayed on the front and back sides thereof. A carrier layer 22 having fine irregularities is formed on the surface, and a catalyst solution 23 containing a catalyst component and a catalyst carrier 24 are formed on the surface of the carrier layer 22.
A slurry 25 composed of and is adhered by coating or the like, and this is dried and baked to fix the catalyst carrier 24 containing the catalyst component to the surface of the carrier layer 22 as shown in FIG. 5B.

The fixed side 19b of the metal plate 19 is fixed to the inside of the exhaust cover 14 by a rivet 26 or by welding, for example, and one to several (three in this embodiment) catalyst sides 19a are connected to the exhaust collecting chamber. It is arranged parallel to the exhaust gas flow g inside 15 and standing upright toward the exhaust port 13.

At this time, the fixed side 19b serves as a spacer that abuts the adjacent metal plates 19 as shown in FIG. 3, so that it becomes easy to provide a constant space between the catalyst sides 19a.

The small holes 21 provided on the catalyst side 19a are
Even if the metal plate 19 is provided on the fixed side 19b side, there is no problem, so that a punching plate or the like can be used as the metal plate 19 as it is.

FIGS. 6A to 6M show examples of the shape of the metal plate 19, and FIG. 6A shows the basic shape of the catalyst side 19.
6A to 6E has a fixed side 1 with respect to the catalyst side 19a.
9b has a non-perpendicular angle, and the catalyst side 19a has a non-flat surface. 6 (F) and 6 (G) show a fold 27 at the center of the catalyst side 19a in the longitudinal direction, and FIGS. 6 (H) to 6 (K) show two faces with the fold 27 as a boundary. The modification of a shape is shown. Further, FIG. 6 (L),
(M) is an example in which the catalyst side 19a has a zigzag shape and a wavy shape. In this way, the angle of the catalyst side 19a and the method of making the fold can be arbitrarily selected.

As described above, the exhaust gas purification device 18 is arranged so that the catalyst sides 19a having the catalyst components fixed to the front and back sides are erected parallel to the exhaust gas flow inside the exhaust gas collecting chamber 15 and toward the exhaust port 13. Therefore, the exhaust gas emitted from the exhaust port 13 of the cylinder 5 contacts the entire front and back surfaces of the catalyst side 19a without hindering the flow of the exhaust gas, and the unburned components in the exhaust gas become sufficient catalyst components. Exhaust gas is efficiently purified because it touches and undergoes an oxidation reaction.

Further, since the exhaust purifying device 18 has a catalyst body having a small volume and is extremely compact, the exhaust purifying device 18 can be accommodated in the internal space of the exhaust gas collecting chamber 15 with a sufficient space, and at the same time, it can be installed. It has a high durability because the catalyst body is made of a metal plate.

[0023]

As described above, the exhaust gas purification apparatus for an outboard motor according to the present invention has two sides in the exhaust gas purification apparatus for an outboard motor in which the catalyst is provided in the exhaust passage of the internal combustion engine. One side of the bent metal plate is the catalyst side, the other side is the fixed side, a large number of small holes are provided on the catalyst side, and the catalyst component is loaded on the front and back sides, and the fixed side is near the exhaust port. It is fixed inside the exhaust passage and is arranged so that one or several catalyst sides stand parallel to the exhaust gas flow inside the exhaust passage and toward the exhaust port.

Therefore, the exhaust gas emitted from the exhaust port of the internal combustion engine contacts the entire front and back surfaces of the catalyst side without obstructing the flow of the exhaust gas, and the unburned components in the exhaust gas undergo oxidation reaction to generate exhaust gas. It is efficiently purified.

Further, since the volume of the catalyst is small and the exhaust gas purifying device can be made very compact, it can be accommodated without any problem even when the internal volume is small such as the exhaust passage of the outboard motor. At the same time, it can be installed extremely easily, and since the catalyst body is made of a metal plate, it has high durability.

[Brief description of drawings]

FIG. 1 is a vertical sectional view of an outboard motor to which the present invention is applied.

FIG. 2 is a sectional view taken along line II-II in FIG.

FIG. 3 is an enlarged view of a part III in FIG.

FIG. 4 is a sectional view taken along line IV-IV in FIG.

5A is a cross-sectional view of the catalyst side showing a state in which a slurry of a carrier layer is applied, and FIG. 5B is a cross-sectional view of the catalyst side showing a state after the slurry is dried and calcined.

6A to 6M are perspective views showing examples of respective shapes of metal plates.

[Explanation of symbols]

 1 Outboard Motor 2 Drive Shaft Housing 4 Internal Combustion Engine 5 Cylinder 13 Exhaust Port 14 Exhaust Cover 15 Exhaust Collecting Chamber 16 Exhaust Pipe 18 Exhaust Purifier 19 Metal Plate 19a Catalyst Side 19b Fixed Side 21 Small Hole 24 Catalyst Carrier 26 Rivet g Exhaust Gas Flow

─────────────────────────────────────────────────── ─── Continuation of the front page (51) Int.Cl. ⁵ Identification code Office reference number FI technical display location F01N 3/28 Z 9150-3G

Claims (1)

[Claims] 1. In an exhaust gas purification apparatus for an outboard motor, wherein a catalyst is provided in an exhaust passage of an internal combustion engine, one side of a metal plate bent so as to have two sides is fixed to a catalyst side and the other side is fixed. The catalyst side is provided with a large number of small holes, the catalyst components are supported on the front and back sides, and the fixed side is fixed inside the exhaust passage near the exhaust port. An outboard engine exhaust gas purification device, which is arranged parallel to the exhaust gas flow and upright toward the exhaust port.