JP4500643B2 - Black smoke purification device for diesel engine - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To simply carry out desorption work for a DOC (oxidation catalyst converter) and a DPF (diesel particulate filter), and securely fix the DOC and the DPF in a muffler body. <P>SOLUTION: A DPF muffler 20 is provided with an outer cylinder 21 having an exhaust gas supply tube 25 protruded on the upstream side, and an open cylinder on the downstream side, an inner cylinder 30 removably inserted to an inner circumferential part of the outer cylinder 21 through a gasket 29, and a downstream side cover 22 detachably fixed to the opening in the outer cylinder 21, and having an exhaust tube 26 for exhaust gas protruded on the downstream side. On a circumferential edge of the opening of the outer cylinder 21 and a circumferential edge of the opening of the downstream cover 22, flanges 23 and 24 are respectively formed. They are connected to each other as the flanges 23 and 24 are abutted on each other in a junction state. <P>COPYRIGHT: (C)2006,JPO&amp;NCIPI

Description

  The present invention relates to a black smoke purification device for a diesel engine, and more particularly to a desorption structure for an oxidation catalyst and a particulate filter.

In order to purify the exhaust gas of a diesel engine, a black smoke purification device for diesel engine (hereinafter referred to as DPF muffler) has an oxidation catalytic converter (hereinafter referred to as DOC) on the upstream side of the exhaust system and a diesel putty on the downstream side. A curate filter (hereinafter referred to as DPF) is arranged in series, and particulate matter such as black smoke (hereinafter referred to as PM) in the exhaust gas is collected by this DPF, and the temperature of the exhaust gas is high. At this time, NO ₂ is generated from NO in the exhaust gas by the action of the oxidation catalyst, and PM collected in the DPF is incinerated and removed using this NO ₂ as an oxidizing agent.

  DOC and DPF need to be periodically cleaned or replaced because the conversion capacity of the catalyst is lowered or contamination is progressed depending on the period of use.

  Therefore, in the conventional DPF muffler, as shown in FIG. 4, the front cover 4 in which the air supply pipe 3 projects from the upstream side of the muffler body 2 is detachably joined via the flange 5. 2, a rear cover 7 having an exhaust pipe 6 projecting from the downstream side 2 is detachably joined via a flange 8. By removing the front cover 4 and the rear cover 7 from the muffler body 2, a DOC 9 and a DPF 10 are respectively attached. Has a structure that can be individually detached.

  As shown in FIG. 5, a rear cover 7 on the downstream side of the muffler body 2 is detachably joined via a flange 8, the rear cover 7 is removed from the muffler body 2, and a DPF 10 is provided inside. There is also a DPF muffler having a structure that can be removed in the order of the thermometer and the DOC 9 after the cartridge case 11 is detached with the DPF 10 attached.

  The method of fixing the DPF muffler to the muffler body 2 of the DPF muffler and the DPF 10 described above is a heat-resistant and heat-insulating material such as a steel net 13 and an interlam mat 14 on the outer periphery of the cartridge case 11 fitted with the DOC 9, DPF 10 or DPF. The mat material is secured and fitted into the muffler body 2 through these mat materials to prevent rattling and displacement within the muffler body 2. There was a problem to be described.

That is, in the case of the structure shown in FIG. 4, when exchanging the DOC 9 and the DPF 10, it is necessary to remove the upstream cover 4 and the downstream cover 7, respectively, and the muffler structure becomes complicated.
In the case of the structure shown in FIG. 5, since only the downstream cover 7 is removed, the muffler structure is simple, but the detaching operation of the DOC 9 and the DPF 10 is troublesome.
In any structure, since the mat members 13 and 14 are wound around the outer periphery and loaded into the muffler body 2, the mat member is likely to curl or wind up during loading, and the loading operation is troublesome and skillful. In addition, pulling out is troublesome because the clues during pulling out cannot be easily grasped.

  SUMMARY OF THE INVENTION The present invention solves the above-described problems, and an object of the present invention is to provide a diesel engine in which DOC and DPF can be easily detached and the DOC and DPF can be securely fixed in the muffler body. A black smoke purification device is provided.

In order to achieve the above object, a black smoke purification apparatus for a diesel engine according to the present invention includes an inner cylinder having an oxidation catalyst and a diesel particulate filter catalyst therein, an outer cylinder into which the inner cylinder is detachably inserted,
An insertion hole that communicates the outer cylinder and the inner cylinder, and a temperature sensor that is detachably attached to the insertion hole and that measures the temperature between the oxidation catalyst and the diesel particulate filter catalyst in the inner cylinder If, when inserted the inner tube into the outer tube, e Bei and positioning means for determining the mating relationship between the outer cylinder and the inner cylinder, said positioning means, the inner periphery of the outer cylinder In the state where the portion of the insertion hole that faces the insertion hole is removed, the rod-shaped protrusion disposed in the axial direction and the outer circumferential surface of the inner cylinder are provided around the rod-like shape. A ring-shaped protrusion having a notch into which the protrusion is fitted, and when inserting the inner cylinder into the outer cylinder, the ring-shaped protrusion having the rod-shaped protrusion and the notch By fitting the protrusion, the inner cylinder is in a predetermined position in the circumferential direction with respect to the outer cylinder. Characterized in that it is fixed to.

  As described above, in the present invention, after the downstream cover is removed and the temperature sensor is removed, the simultaneous removal / removal operation of the DOC and DPF is completed by the insertion / removal operation of the inner cylinder. It is.

  Further, in the black smoke purification device for a diesel engine according to the present invention, a ring-shaped protrusion that is provided around the outer peripheral surface of the inner cylinder and a ring-shaped protrusion that is provided around the inner peripheral surface of the outer cylinder. And when the inner cylinder is inserted into the outer cylinder, compared to the case where a mat member is used to fit the inner cylinder to the outer cylinder via the fixing ring, The loading operation can be easily performed without being twisted or wound, and the positioning in the axial direction when the inner cylinder is inserted into the outer cylinder is simplified.

  And in the black smoke purification apparatus for diesel engines by this invention, the rod-shaped protrusion part arrange | positioned in the axial direction of the inner peripheral surface of an outer cylinder, and the circumference of the outer peripheral surface of an inner cylinder, and a rod-shaped protrusion part are provided. A ring-shaped protrusion having a notch to be fitted is provided, and positioning of the inner cylinder in the circumferential direction when the inner cylinder is inserted into the outer cylinder is simplified.

  Further, in the black smoke purification device for diesel engine according to the present invention, the axial positioning and the circumferential positioning of the inner cylinder when the inner cylinder is inserted into the outer cylinder are reliably performed, and the temperature sensor is inserted. Further, the center of the insertion hole drilled in the outer cylinder and the center of the insertion hole drilled in the inner cylinder always coincide with each other, so that the trouble of fitting the outer cylinder and the inner cylinder for inserting the temperature sensor can be saved.

  According to the present invention, the inner cylinder having the DOC and DPF can be easily attached and detached, and the inner cylinder is positioned in the axial direction and the circumferential position and reliability when the inner cylinder is inserted into the outer cylinder. The present invention relates to a black smoke purification device for a diesel engine that can be performed in a short time. DESCRIPTION OF EMBODIMENTS Hereinafter, preferred embodiments of the present invention will be described in detail with reference to the drawings.

  FIG. 1 is a side sectional view including a partially enlarged portion of a black smoke purification device for a diesel engine according to the present invention. FIG. 2 is a half sectional view taken along line AA in FIG. FIG. 3 is an exploded perspective view of the black smoke purification device for a diesel engine according to the present invention.

  As shown in FIGS. 1 and 2, the DPF muffler 20 includes an outer cylinder 21 having a cylindrical shape with an exhaust gas supply pipe 25 projecting on the upstream side and an opening on the downstream side, and an inner peripheral portion of the outer cylinder 21. An inner cylinder 30 that is detachably inserted through a gasket 29, and a downstream cover 22 that is detachably disposed at an opening of the outer cylinder 21 and has an exhaust pipe 26 for exhaust gas projecting downstream. The flanges 23 and 24 are formed on the periphery of the opening of the outer cylinder 21 and the periphery of the opening of the downstream cover 22, respectively, and are connected in a state where the flanges 23 and 24 are butted together. Fastening means such as a buckle, a clamp tool, and a bolt and nut are employed as the connecting means.

The material of the outer cylinder 21, the inner cylinder 30, and the downstream cover 22 is, for example, a heat resistant material such as stainless steel.
A temperature sensor mounting boss 27 protrudes from the outer peripheral surface of the outer cylinder 21 in the axial center, and the temperature sensor mounting boss 27 has an insertion hole 27a through which the temperature sensor 28 can be inserted.
The inner cylinder 30 is integrated with a cylindrical portion 31 having an outer diameter slightly smaller than the inner diameter of the outer cylinder 21, and a downstream peripheral edge of the cylindrical portion 31, and is sandwiched between the flanges 23 and 24 in a mounted state of the outer cylinder. The flange 32 is provided.

  Further, the DOC 33 is fixed on the upstream side in the inner cylinder 30, and the DPF 34 is fixed on the downstream side with a predetermined gap therebetween. Furthermore, an insertion hole 35 that penetrates the inside and outside of the cylindrical portion 31 through which the temperature sensor 28 can be inserted is opened in a gap portion between the DOC 33 and the DPF 34.

  The gasket 29 disposed at the upstream end inside the outer cylinder 21 is used for fitting the tip of the inner cylinder 30 to position the inner cylinder in the axial direction when the inner cylinder is inserted. A groove 29 a for receiving the tip of the cylindrical portion 31 is formed inside the gasket 29. Therefore, when the inner cylinder 30 is inserted into the outer cylinder 21, the axial position is determined by inserting until the tip of the inner cylinder 30 contacts the groove 29a.

  A pair of front and rear fixing rings 36 having a semicircular cross section are fitted and fixed to the outer peripheral portion of the cylindrical portion 31. The fixing ring 36 has an outer diameter that is substantially the same as the inner diameter of the outer cylinder 21. For example, the fixing ring 36 is a material that is rich in heat resistance and elasticity, such as stainless steel, and the inner cylinder 30 is loaded in the outer cylinder 21. The cylindrical portion 31 is fitted and held with a predetermined gap between the cylindrical portion 31 and the outer cylinder 21 in accordance with the elasticity. Further, since the inner cylinder is fitted to the outer cylinder via the fixing ring, positioning in the axial direction when the inner cylinder is inserted into the outer cylinder is facilitated.

  Then, a semicircular projection 37 having a semicircular cross section for guiding the inner cylinder in the axial direction of the outer cylinder 21 is integrally fixed to the inner peripheral surface of the outer cylinder 21 at the projecting position of the temperature sensor mounting boss 27. A concave groove 36 a is formed in a part of the outer peripheral portion of the fixing ring 36 so as to engage with the protrusion 37. A concave groove 29 b is also formed in a part of the outer periphery of the gasket 29 so as to engage with the protrusion 37. Therefore, when the inner cylinder 30 is inserted into the outer cylinder 21, the groove 36 a of the fixing ring 36 that is fitted and fixed to the outer peripheral portion of the inner cylinder 30 is engaged with the protrusion 37, so that the circumferential position Is determined.

  That is, when the inner cylinder 30 is inserted into the outer cylinder 21, first, the groove 36a is inserted while being engaged with the protrusion 37, whereby the circumferential fitting relationship between the inner cylinder 30 and the outer cylinder 21 is determined. Since the axial fitting relationship between the inner cylinder and the outer cylinder is uniquely determined by inserting the tip of the inner cylinder 30 until it contacts the groove 29a of the gasket 29, a temperature sensor is inserted. Therefore, the center of the insertion hole 27a drilled in the outer cylinder 21 and the center of the insertion hole 35 drilled in the inner cylinder 30 always coincide.

  As shown in FIG. 3, in this embodiment, the temperature sensor passage position of the protrusion 37 is perforated and removed. However, even if the protrusion 37 is not fixed at the crossing position of the insertion hole 27a, the concave groove As long as the inner cylinder 30 is completely loaded, the insertion hole 35 may be positioned so that the insertion hole 35 is inevitably positioned at the position corresponding to the insertion hole 27a.

Moreover, in this embodiment, although the protrusion 37 was made into one place, two or more places may be sufficient, and what is necessary is just to form the concave grooves 29a and 36a in two places or more according to the position.
Therefore, as shown in FIG. 3, when the gasket 29 and the inner cylinder 30 are positioned and loaded inside the outer cylinder 21 from each part disassembled state, the flange 32 overlaps the flange 23 of the outer cylinder 21 and the insertion hole 35. Since the temperature sensor 28 coincides with the insertion hole 27a, the temperature sensor 28 can be inserted into the inner cylinder 30, and then the downstream cover 22 is covered with the opening, so that as shown in FIG. Both ends are positioned and are fixedly fitted and fixed by the fixing ring 36 inside the outer cylinder 21 with a predetermined gap.

  Further, when the inner cylinder 30 is extracted from this assembled state, the flange 32 of the inner cylinder 30 becomes a clue at the time of extraction by removing the downstream cover 22 after the temperature sensor 28 is extracted. It can be easily removed with a provided tap or the like.

It is a sectional side view including the one part enlarged part of the black smoke purification apparatus for diesel engines which concerns on this invention. It is a half sectional view in the AA line of FIG. It is a disassembled perspective view of the black smoke purification apparatus for diesel engines which concerns on this invention. It is a sectional side view which shows an example of the conventional black smoke purification apparatus for diesel engines. It is side sectional drawing which shows the other example of the conventional black smoke purification apparatus for diesel engines.

Explanation of symbols

20 DPF muffler 21 Outer cylinder 22 Downstream cover 23, 24 Flange 25 Air supply pipe 26 Exhaust pipe 27 Temperature sensor mounting boss 27a Insertion hole 28 Temperature sensor 29 Gasket 29a Concave groove 30 Inner cylinder 31 Tube part 31a Groove 32 Flange 33 DOC ( Oxidation catalytic converter)
34 DPF (diesel particulate filter)
35 Insertion hole 36 Fixing ring 36a Concave groove 37 Projection

Claims (1)

An inner cylinder having an oxidation catalyst and a diesel particulate filter catalyst inside;
An outer cylinder in which the inner cylinder is detachably inserted;
An insertion hole communicating the outer cylinder and the inner cylinder;
A temperature sensor that is detachably attached to the insertion hole, and that measures a temperature between the oxidation catalyst in the inner cylinder and the diesel particulate filter catalyst;
When inserted the inner tube into the outer tube, Bei example a positioning means for determining the mating relationship between the outer cylinder and the inner cylinder,
The positioning means includes
A rod-shaped protrusion disposed in the axial direction in a state where the insertion hole is exposed at an inner circumferential surface of the outer cylinder at a position where the insertion hole is formed,
A ring-shaped protrusion having a notch that is provided around the outer peripheral surface of the inner cylinder and into which the rod-shaped protrusion is fitted;
When the inner cylinder is inserted into the outer cylinder, the inner cylinder is rotated around the outer cylinder by fitting the rod-shaped protrusion and the ring-shaped protrusion having the notch. A black smoke purification device for a diesel engine, which is fixed at a predetermined position in the direction .

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