JPH0561421U - Catalyst muffler device - Google Patents

Abstract

(57) [Abstract] [Purpose] The main feature of this invention is to integrate the function as an oxidation catalyst and the function as a muffler into one. [Structure] A ceramic honeycomb 17 in which small hole groups 17a are alternately plugged is provided, and a catalyst 19 is coated on the surface of the ceramic honeycomb 17 to form a catalyst muffler device. The ceramic honeycombs 17 are alternately plugged to form a muffler-like function of suppressing the passage of sound, and the catalysts 1 are attached to the ceramic honeycombs 17.
By coating 7a, a function of converting harmful components such as HC contained in the exhaust gas into a harmless substance by an oxidation reaction was formed.

Description

[Detailed description of the device]

[0001]

[Industrial applications]

 The present invention relates to a catalyst muffler device mounted on a gas system of an engine.

[0002]

[Prior Art]

 Since exhaust gas contains harmful components, and the exhaust gas becomes noise, the engine installed in a vehicle for traveling is equipped with exhaust gas measures and noise measures.

As a countermeasure for this, conventionally, as shown in FIG. 4, a structure is provided in which an exhaust passage 3 connected to an exhaust manifold 2 of an engine 1 is provided with a catalytic converter 4 and a muffler 5 from the upstream side.

As shown in FIG. 5, the catalytic converter 4 includes, for example, a honeycomb type oxidation catalyst 7a, an electric heater 7b (immediately after the engine is started, an oxidation catalyst 7a is oxidized to enhance the catalytic effect of the oxidation catalyst 7a). (For heating the catalyst 7a), a heat reflection portion 7c (for directing heat of the electric heater 7b to the oxidation catalyst 7a), and the like are used. The muffler 5 has, for example, a structure in which a muffler chamber (not shown) is formed in the casing 8 and the like, and the harmful components such as HC contained in the exhaust gas in the catalytic converter 4 are harmless by the oxidation reaction of the oxidation catalyst 7. a H ₂ and O such as the conversion, are the exhaust gas in muffler 5 to lower and sound pressure.

[0005]

[Problems to be solved by the device]

 However, such catalytic converter 4 and muffler 5 require a large area for installation.

Therefore, as shown in FIG. 2, the pipe forming the discharge passage 3 needs a large number of bent portions 9, and accordingly, the length of the pipe becomes longer and the pressure loss (pressure loss) in the discharge passage 3 is increased. ) Was increased.

Moreover, since the catalytic converter 4 and the muffler 5 have to be separately arranged, there is a disadvantage that the mounting positions of the catalytic converter 4 and the muffler 5 are also limited.

The present invention has been made in view of such circumstances, and its purpose is to make it possible to combine a function as an oxidation catalyst and a function as a muffler into one. It is to provide a muffler.

[0009]

[Means for Solving the Problems]

 In order to achieve the above object, the present invention provides a catalyst muffler device by providing a ceramic honeycomb in which small hole groups are alternately plugged on the end side, and coating a catalyst on the surface of the ceramic honeycomb. It is in.

[0010]

[Action]

 According to the catalyst muffler device of the present invention, the function as the oxidation catalyst and the function as the muffler coexist in the ceramic honeycomb. That is, the ceramic honeycomb is alternately plugged, so that a function of suppressing the passage of sound is formed in the small hole which is communicated with the inlet side and the outlet side. As a result, sound is suppressed in the small hole group, and gas passes through the wall of the ceramic honeycomb. Further, by coating the catalyst on the ceramic honeycomb, harmful components such as HC contained in the exhaust gas are converted into harmless substances by the oxidation reaction. In other words, the catalytic muffler device has both a noise reducing effect and a purifying effect. As a result, the measures taken with the catalytic converter and the muffler can be reduced to one device.

[0011]

【Example】

 The invention will be described below with reference to an embodiment shown in FIGS.

FIG. 1 shows an example in which the present invention is applied to an exhaust system of a traveling methanol engine mounted on an automobile, for example, 11 is a methanol engine, and 12 is an exhaust manifold of the engine 11.

The exhaust manifold 12 is connected to an exhaust passage 13 whose tip is open to the atmosphere. A catalyst muffler device 14, which is an essential part of the present invention, is installed in the middle of the exhaust passage 13. The structure of the catalyst muffler device 14 is shown in FIGS. 2 and 3.

Explaining the structure of the catalyst muffler device 14, reference numeral 15 is, for example, a cylindrical casing. An inlet 16a is formed at one end of the casing 15, and an outlet 16b is formed at the other end. The introduction portion 16a communicates with the exhaust manifold 12 side, and the derivation portion 16b communicates with the tip end portion of the discharge passage 13. The ceramic honeycomb 17 is housed in the casing 15 on the side of the lead-out portion 16b.

The ceramic honeycomb 17 is made of ceramic into a honeycomb having an outer shape corresponding to the inner cavity shape of the casing 15. Further, as shown in FIG. 3, the ceramic honeycomb 17 has the openings alternately closed at both ends of the small hole group 17a. The checkerboard-like plugging of the ceramic honeycomb 17 allows exhaust gas to pass through the walls. With this structure, inside the ceramic honeycomb 17, a sound suppressing portion 18 that provides the same noise reduction effect as the muffler is configured.

The surface of the ceramic honeycomb 17 is coated with a catalyst 19 to make the ceramic honeycomb 17 function as an oxidation catalyst (convert harmful components such as HC into harmless components by oxidation reaction). ..

An electric heater 20 for heating the ceramic honeycomb 17 and a heat reflecting portion 21 for directing the heat of the heater to the ceramic honeycomb 17 are provided on the introduction portion 16 a side in the casing 15. Although not shown, the electric heater 20 is connected to the control unit so that when the engine is started, the electric heater 20 is energized for a predetermined time immediately after that. Thus, immediately after the engine is started, the temperature of the ceramic honeycomb 17 is increased to enhance the catalytic effect. Next, the operation of the catalyst muffler device 14 thus configured will be described.

When the methanol engine 11 is started, a control unit (not shown) energizes the electric heater 20 in response to the start of the engine 11. Then, the ceramic honeycomb 17 is heated. As a result, the temperature of the ceramic honeycomb 17 rapidly rises, and the catalyst 19 operates efficiently immediately after the engine is started. On the other hand, the exhaust gas exhausted from the methanol engine 11 is introduced into the ceramic honeycomb 17 through the exhaust manifold 12 and the introduction portion 16a.

Here, since the ceramic honeycomb 17 has a function of suppressing the passage of sound in the small hole group 17a by being alternately plugged, the sound is suppressed in the small hole group. .. As a result, the noise caused by the exhaust gas is reduced. Further, the gas passes through the wall portion of the ceramic honeycomb 17. At this time, the harmful components of the exhaust gas such as unburned HC are physically adsorbed.

Since the ceramic honeycomb 17 is coated with the catalyst 19, harmful components such as HC contained in the exhaust gas are converted into harmless substances by the oxidation reaction. Then, the exhaust gas that has been purified is discharged to the atmosphere through the exhaust passage 3. That is, the catalyst muffler device 14 has both the function of reducing noise and the function of purifying. Therefore, one catalytic muffler device 14 can be used for the countermeasures that have been conventionally taken with the catalytic converter and the muffler.

Therefore, when installing the apparatus vinegar, as is apparent from FIG. 1, the pipe forming the discharge path 13 has fewer bent portions, and the pipe length can be shortened accordingly. However, it is possible to reduce the pressure loss (pressure loss). In addition, since one catalyst muffler device 14 needs to be installed, there is an advantage that it is much easier to mount on a vehicle than in the past.

In addition, the structure in which the exhaust gas passes through the ceramic honeycomb 17 to adsorb the harmful components of the exhaust gas reduces the harmful components when the catalytic effect at the engine start does not work sufficiently. It is effective.

In addition, when the ceramic honeycomb 17 is combined with the electric heater 20 in a structure for enhancing the catalytic effect immediately after the engine is started as in the above embodiment, the heat from the electric heater 20 can be stored ( Since the small hole group 17a is closed in a checkered pattern), the catalytic effect can be immediately applied immediately after the engine is started. These effects are effective for engines that do not emit black smoke and require an oxidation catalyst, such as the above-described methanol engine 1 and gasoline engine.

[0024]

[Effect of the device]

 As described above, according to this invention, the function as an oxidation catalyst and the function as a muffler can be integrated.

Therefore, since only one catalyst muffler device needs to be installed, the pipe forming the discharge path has few bends and the length of the pipe can be short. Moreover, the pressure loss is also reduced. In addition, since it is sufficient to install one catalyst muffler device, it becomes much easier to mount on a car than before.

In addition, the fact that the exhaust gas passes through the ceramic honeycomb can be used to adsorb the harmful components of the exhaust gas. This function is effective in reducing harmful components when the catalytic effect at engine start does not work sufficiently.

[Brief description of drawings]

FIG. 1 is a diagram showing a catalyst muffler device according to an embodiment of the present invention together with an exhaust diameter system of an engine equipped with the device.

FIG. 2 is a sectional view of a catalyst muffler device.

3 is a sectional view taken along the line AA in FIG.

FIG. 4 is a diagram showing an exhaust system in a conventional engine against exhaust gas and noise.

FIG. 5 is a sectional view showing a conventional catalytic converter.

[Explanation of symbols]

14 ... Catalyst muffler device, 15 ... Casing, 16a ...
Introducing part, 16b ... Deriving part, 17 ... Ceramic honeycomb,
17a ... Small hole group, 19 ... Catalyst, 20 ... Electric heater, (combustion means), 20 ... Oxidation catalyst.

Claims (1)

[Scope of utility model registration request] 1. A honeycomb structure made of ceramic,
A catalyst muffler device comprising: a ceramic honeycomb in which small hole groups are alternately plugged on the end side; and a catalyst coated on the surface of the ceramic honeycomb.