JP5361688B2 - Exhaust purification device - Google Patents

Description

  The present invention relates to an exhaust emission control device for a diesel engine.

  As an exhaust gas purification device for purifying exhaust gas from a diesel engine, as described in Patent Document 1, a DOC (Diesel Oxidation Catalyst), a DPF (Diesel Particulate Filter), and an SCR (Selective Catalyst Reduction) catalyst are sequentially provided in an exhaust passage from upstream. Those arranged in series are known. In this exhaust purification device, for example, for a vehicle such as a truck, the DOC, DPF, and SCR catalyst are mounted below a frame extending in the front-rear direction of the vehicle.

JP 2004-218475 A

  However, with the recent tightening of regulations on exhaust purification, it is necessary to increase the size of the DOC, DPF and SCR catalyst, and it has become difficult to ensure the minimum ground clearance required for vehicle travel. .

  Further, if the DOC, DPF, and SCR catalyst are mounted on the outer side of the vehicle width of the frame, there is a possibility that they interfere with the bodywork mounted on the upper surface of the frame or protrude outside the vehicle.

  In view of the above-described problems, an object of the present invention is to provide an exhaust emission control device that can cope with at least the enlargement of DPF and SCR catalyst.

For this reason, an exhaust emission control device according to the present invention has a first casing that extends in the vehicle front-rear direction while having a cylindrical shape that accommodates at least a DPF that collects particulate matter in the exhaust, and a vehicle width. When viewed from the direction and above, the first housing is diagonally above and outside the vehicle width, or diagonally below and within the vehicle width so that at least a part of the first housing overlaps. A cylindrical second housing that accommodates at least an SCR catalyst that is selectively reduced and purifies nitrogen oxides, and is disposed above the first housing and the second housing. On the side of the upper casing that is located and above the lower casing that is positioned below, the communication pipes that connect the far ends of each casing and the outer surface of the frame outside the vehicle width A fixed portion that is fixed so as to extend in the direction, and a fixed portion that does not protrude upward from the upper surface of the frame. And a support bracket having an overhang portion extending outward from the upper end of the vehicle width, and the tip of the overhang portion of the support bracket is inward of the upper half of the outer circumferential surface of the upper casing. While the upper casing is supported at the portion facing the, the fixing portion of the support bracket supports the lower casing.
The “tip” of the overhanging portion of the support bracket is a range including the periphery thereof.

  According to the present invention, the two cylindrical casings that respectively accommodate the DPF and the SCR catalyst are disposed so as to be higher from the inside of the vehicle toward the outside of the vehicle, and the far end portions of each casing are The communication pipe that communicates with the pipe is piped close to the side of the upper casing and above the lower casing. And while the front-end | tip of the overhang | projection part of a support bracket supports an upper housing | casing in the part which faces a vehicle width inside of the outer peripheral surface of the upper half side of an upper housing | casing, the fixing | fixed part of a support bracket is a lower housing | casing Support. Accordingly, since the exhaust purification device can be housed in the dead space of the vehicle, interference with the bodywork mounted on the upper surface of the frame and securing of each housing to the outside of the vehicle while ensuring a minimum ground clearance. It is possible to cope with at least enlargement of the DPF and the SCR catalyst without projecting the body.

The side view which looked at the exhaust emission control device which concerns on this invention from the vehicle front The perspective view about the exhaust emission control device which concerns on this invention Explanatory drawing when the exhaust emission control device according to the present invention is elastically supported Explanatory drawing about the support of the 2nd housing | casing of FIG. The perspective view which shows another shape of the support bracket of the exhaust gas purification apparatus which concerns on this invention

Hereinafter, the present invention will be described in detail with reference to the accompanying drawings.
1 and 2 show an embodiment of the present invention. The exhaust emission control device is attached to one side in the vehicle width direction of a ladder-shaped frame 10 in a vehicle such as a truck equipped with a diesel engine, for example.

  The exhaust purification apparatus includes a cylindrical first casing 12, a cylindrical second casing 14, a communication pipe 16 that connects the distal ends of the casings 12 and 14, and the frame 10. Two support brackets 18 that are fixed to be separated in the vehicle front-rear direction and support the casings 12 and 14 are configured.

  The first casing 12 has its exhaust upstream end 12a facing the vehicle rear side, its exhaust downstream end 12b facing the vehicle front side, and the second casing 14 has its exhaust upstream end 14a facing the vehicle rear side, The exhaust downstream end portion 14b is disposed toward the vehicle front side. That is, both the casings 12 and 14 are disposed so that the axis thereof extends substantially in the vehicle front-rear direction. Note that the first casing 12 and the second casing 14 may be arranged such that their axes are parallel to each other.

  In addition, the second housing 14 is located outward of the vehicle width from the first housing 12 so as to at least partially overlap the first housing 12 when viewed from the vehicle width direction and from above the frame. And it is located diagonally above the first housing 12. The first housing 12 houses the DPF, and the second housing 14 houses the SCR catalyst.

  The communication pipe 16 is located on the side of the second casing 14 (upper casing) and above the first casing 12 (lower casing). The exhaust downstream end 12b and the exhaust upstream end 14a communicate with each other.

  The communication pipe 16 can be configured to include a straight pipe portion 16a and connecting pipe portions 16b and 16c. The straight pipe portion 16a is disposed in the vicinity of the second casing 14 on the side of the second casing 14 and above the first casing 12 with an axis parallel to the axis of each casing. It is a straight hollow tube having a smaller diameter than the bodies 12 and 14. In addition, the connecting pipe portions 16b and 16c communicate and connect the straight tube portion 16a and the near end portions of the casings 12 and 14 so that the far end portions are connected via the straight tube portion 16a. .

  An exhaust inflow pipe 20 that turns the exhaust of the diesel engine back to the front of the vehicle and flows into the exhaust upstream end 12a (end of the vehicle rear side) of the first housing 12 covers the end surface of the end 12a. Connected. Further, the exhaust exhaust pipe 22 that exhausts exhaust that has passed through the second housing 14 from its exhaust downstream end portion 14b (end portion on the front side of the vehicle) to the rear of the vehicle through the lower portion of the second housing 14 and exhausted. However, they are connected so as to cover the end face of the end portion 14b.

  The support bracket 18 is fixed to the outer surface 10a outside the vehicle width of the frame 10 so that the member extends in the vertical direction, and the fixing portion 18a so as not to protrude upward from the upper surface 10b of the frame 10. And an overhanging portion 18b extending outward from the vehicle width. The lower portion of the fixed portion 18a may extend inward and downward in the vehicle width, or may extend downward in the vehicle width inward and downward.

  The tip of the overhanging portion 18b of the support bracket 18 supports the second housing 14 at a portion of the upper half outer peripheral surface of the second housing 14 that faces the vehicle width inward. On the other hand, the fixing portion 18 a of the support bracket 18 supports the first housing 12. When the lower portion of the fixing portion 18a extends inward and downward in the vehicle width, or when extending downward in the vehicle width inward and downward, the first casing 12 is extended at the extended end. Can be supported. Further, in order to stably support each of the casings 12 and 14 with the support bracket 18, the lower end of the fixing portion 18 a is a part of the outer peripheral surface on the lower half side of the first casing 12 facing the vehicle width inward. It is desirable to support the first housing 12. The “extension end” or “lower end” of the fixing portion 18a of the support bracket 18 is a range including the periphery of the extension end surface or the lower end surface.

  The support bracket 18 is obtained, for example, by bending a long material having a substantially hat-shaped cross section in which flange surfaces are arranged on both sides in the longitudinal direction in order to ensure the required bending strength while reducing the weight. It is desirable to be. In this case, when the support bracket 18 is fixed to the frame 10, the opening of the support bracket 18 may be opposed to the outer surface 10 a of the frame 10, so that the flange surface of the fixing portion 18 a is outside the frame 10. The support bracket 18 can be stably fixed to the frame 10 while being brought into contact with the side surface 10a. Further, in order to further improve the bending strength, a reinforcing plate 18c that covers at least a part of the opening of the overhanging portion 18b may be joined and attached to the flange surface of the overhanging portion 18b.

  The support bracket 18 directly supports the first housing 12 and the second housing 14. That is, for the first housing 12, for example, the first stay 12c erected from the outer peripheral surface of the first housing 12 toward the fixing portion 18a is fixed to the flange surface of the fixing portion 18a. As for the second casing 14, for example, a second stay 14c erected from the surface facing the vehicle width inside of the outer peripheral surface on the upper half side of the second casing 14 toward the straight pipe portion 16a. Is fixed to the bottom surface located below the lower surface of the tip of the overhang portion 18b.

  According to such an exhaust purification device, the cylindrical first housing 12 that houses the DPF and the cylindrical second housing 14 that houses the SCR catalyst are directed from the inside of the vehicle toward the outside of the vehicle. The communication pipe 16 that is disposed so as to be higher in this order and communicates with the distal ends of the respective casings 12 and 14 is provided above the first casing 12 and on the second casing 14 side. The pipes are in close proximity. And while the front-end | tip of the overhang | projection part 18b of the support bracket 18 supports the 2nd housing | casing 14 in the part which faces the vehicle width inside among the outer peripheral surfaces of the upper half side of the 2nd housing | casing 14, a support bracket The 18 fixed portions 18 a support the first housing 12. Accordingly, the exhaust purification device can be housed in the dead space of the vehicle, so that the minimum ground clearance can be ensured, interference with the bodywork mounted on the upper surface of the frame 10, and the housing outside the vehicle. It is possible to cope with at least an increase in the size of the DPF and the SCR catalyst without protruding 12, 14 and the like.

  In addition, when the fixing portion 18a of the support bracket 18 extends inward and downward in the vehicle width, or extends downward inward and downward of the vehicle width, the first housing at the extended end thereof. Since the body 12 is supported and the first housing 12 and the second housing 14 can be arranged inward of the vehicle width, it is possible to cope with further enlargement of at least the DPF and the SCR catalyst. it can.

  In the exhaust emission control device of the present embodiment, the first housing 12 can be divided into two parts, that is, an upstream side of exhaust and a downstream side of exhaust at an arbitrary position in the axial direction, for example, approximately 12d near the center. It can also be. Thereby, at the time of DPF cleaning, the exhaust upstream side of the first casing 12 and the exhaust inflow pipe 20 which are lighter than the exhaust purification device as a whole are removed to the rear of the vehicle without removing the exhaust purification device from the frame 10. The DPF accommodated in the first housing 12 can be easily taken out.

  The first casing 12 has a DOC on the exhaust upstream side of the DPF, and the second casing 14 has an ammonia oxidation catalyst for oxidizing ammonia that has passed through the SCR catalyst on the exhaust downstream side of the SCR catalyst. Each can be stored. In this case, the first housing 12 may have a structure that can be divided with a surface that separates the DOC and the DPF as a boundary. Thereby, the DPF can be taken out without separating the DOC from the first housing 12.

  Further, the support bracket 18 directly supports the first casing 12 and the second casing 14, but instead of this, as shown in FIG. You may support through the elastic member 24, respectively. For example, FIG. 4 illustrates the second housing 14 with the upper surface of the second stay 14c formed in a U-shaped cross section facing downward and the upper surface thereof positioned below the lower surface of the distal end of the overhanging portion 18b. With an elastic member 24 such as rubber or a spring material interposed between the upper surface and the bottom surface, bolts are inserted into the upper surface, the bottom surface, and through holes formed in the elastic member 24 to Fastening with a nut from the protruding portion 18b side or the second stay 14c side. Thereby, it can suppress that the vibration which generate | occur | produces from an engine is transmitted to a vehicle body via an exhaust gas purification apparatus. However, even when each housing 12 and 14 is directly fixed to the support bracket 18, for example, by using an accordion exhaust pipe between the engine and the exhaust inflow pipe 20, vibrations generated from the engine are It is possible to suppress transmission to the vehicle body via the exhaust purification device.

  Furthermore, instead of disposing the second housing 14 obliquely above the first housing 12, the first housing 12 may be disposed obliquely above the second housing 14. Also with this configuration, the effects of the above-described embodiment can be achieved. In this case, the exhaust inflow pipe 20 may be connected so as to cover the end surface on the vehicle front side of the first casing 12, and the exhaust discharge pipe 22 is connected to the end of the second casing 14 on the vehicle rear side. What is necessary is just to cover and connect a part end surface.

  In the exhaust purification apparatus of the present embodiment, the support bracket 18 has a substantially hat-shaped cross section. However, the present invention is not limited to this, and a known structural material such as a channel material as shown in FIG. 5 may be used.

  As shown in FIGS. 1 and 2, a nozzle attachment hole 26 for attaching an injection nozzle that injects a liquid reducing agent toward the inside of the straight tube portion 16 a is formed in the connection tube portion 16 b. This ensures a sufficient linear length for the uniform diffusion of the liquid reducing agent into the exhaust. As an aid for uniform diffusion, a diffuser plate having a mesh shape or the like may be installed in the communication pipe 16.

DESCRIPTION OF SYMBOLS 12 1st housing | casing 14 2nd housing | casing 16 Communication pipe 16a Straight pipe part 16b, c Connection pipe part 18 Support bracket 18a Fixing part 18b Overhang | projection part 18c Exhaust inflow pipe 22 Exhaust discharge pipe 24 Elastic member

Claims (6)

A first housing that has a cylindrical shape that accommodates at least a DPF that collects particulate matter in the exhaust, and whose axis extends in the vehicle front-rear direction;
When viewed from the vehicle width direction and from above, the first housing is diagonally above and outside the vehicle width, or diagonally below so that at least a part of the first housing overlaps. A cylindrical second housing that is disposed at the inner side of the vehicle width and contains at least an SCR catalyst that selectively reduces and purifies nitrogen oxides;
Of the first housing and the second housing, the far end portions of the respective housings communicate with each other on the side of the upper housing located above and above the lower housing located below. A communication pipe
A fixed portion that is fixed so that a member extends in the vertical direction on an outer side surface of the outer side of the vehicle width of the frame, and extends outward from the upper end of the fixed portion so as not to protrude upward from the upper surface of the frame. A support bracket having an overhang, and
Comprising
While the tip of the projecting portion of the support bracket supports the upper casing in the portion facing the vehicle width inward of the outer peripheral surface of the upper half of the upper casing,
The exhaust purifying device according to claim 1, wherein the fixing portion of the support bracket supports the lower casing.   The lower portion of the fixed portion extends inward and downward in the vehicle width, or extends downward and inward in the vehicle width, and extends downward to support the lower casing at an extended end thereof. The exhaust emission control device according to claim 1.   The exhaust purification device according to claim 1, wherein the support bracket has a hat-shaped cross section.   The exhaust emission control device according to claim 3, wherein a reinforcing plate that covers at least a part of the opening is attached to the projecting portion of the support bracket.   The exhaust purification device according to any one of claims 1 to 4, wherein the support bracket directly supports the upper casing and the lower casing.   The exhaust purification device according to any one of claims 1 to 4, wherein the support bracket supports the upper casing and the lower casing via an elastic member.

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