WATER INGRESS PREVENTING STRUCTURE FOR TAILPIPE

Abstract

Disclosed is a water ingress preventive structure for a tailpipe which discharges exhaust gas outside of a vehicle at a terminal of an exhaust passage system. A curved shape is imparted to the tailpipe. A partition is mounted on an inner periphery of a curved portion outward of a curved direction so as to be gradually spaced apart from the inner periphery toward downstream in a direction of flow of the exhaust gas. Thus, a dead end portion is defined by the partition and the inner periphery of the curved portion outward of the curved direction.

Claims

1: A water ingress preventive structure for a tailpipe for discharge of exhaust gas outside of a vehicle at a terminal of an exhaust passage system, a curved shape being imparted to said tailpipe, comprising a partition mounted on an inner periphery of a curved portion, outward of a curved direction, of said tailpipe so as to be gradually spaced apart from said inner periphery toward downstream in a direction of flow of the exhaust gas, whereby a dead end portion is defined by said partition and said inner periphery of the curved portion outward of the curved direction.

2: The water ingress preventive structure for the tailpipe as claimed in claim 1, wherein said curved portion is distended outward of the curved direction such that, in a condition without the partition, a flow passage cross-sectional area at a defined position of the dead end portion is larger than that upstream of the curved portion.

3: The water ingress preventive structure for the tailpipe as claimed in claim 1, wherein the flow passage cross-sectional area decreased by the partition is larger than an opening cross-sectional area of an outlet of the tailpipe.

4: A water ingress preventive structure for a tailpipe for discharge of exhaust gas outside of a vehicle at a terminal of an exhaust passage system, a curved shape being imparted to the tailpipe, comprising a drainage opening on a curved portion of the tailpipe at a position outward of a curved direction and opposite to an outlet of said tailpipe and a cover for covering, in a spaced-apart relationship, an outer periphery of said curved portion outward of the curved direction so as not to block said drainage opening, said cover extending upstream in a scroll shape from a downstream end of said drainage opening to open a drainage port upstream of said drainage opening.

5: The water ingress preventive structure for the tailpipe as claimed in claim 4, wherein the curved shape is vertically imparted to the tailpipe such that the flow of the exhaust gas from upward to downward is curved into a horizontal direction and is directed to the outlet.

6: The water ingress preventive structure for the tailpipe as claimed in claim 4, wherein the flow passage cross-sectional area of the curved portion is gradually reduced toward the outlet of the tailpipe such that ambient air can be taken into the tailpipe through the drainage port due to an effect of reduced pressure resulting from increase in flow rate of the exhaust gas directed to said outlet.

7: The water ingress preventive structure for the tailpipe as claimed in claim 2, wherein the flow passage cross-sectional area decreased by the partition is larger than an opening cross-sectional area of an outlet of the tailpipe.

8: The water ingress preventive structure for the tailpipe as claimed in claim 5, wherein the flow passage cross-sectional area of the curved portion is gradually reduced toward the outlet of the tailpipe such that ambient air can be taken into the tailpipe through the drainage port due to an effect of reduced pressure resulting from increase in flow rate of the exhaust gas directed to said outlet.

Description

BRIEF DESCRIPTION OF DRAWINGS

[0025] FIG. 1 is a perspective view showing a conventional example;

[0026] FIG. 2 is a front view of the tailpipe shown in FIG. 1;

[0027] FIG. 3 is a view looking in a direction of arrows III in FIG. 2;

[0028] FIG. 4 is a perspective view showing an embodiment of the invention;

[0029] FIG. 5 is a front view of the tailpipe shown in FIG. 4;

[0030] FIG. 6 is a view looking in a direction of arrows VI in FIG. 5;

[0031] FIG. 7 is a sectional view in a direction of arrows VII in FIG. 5;

[0032] FIG. 8 is a perspective view showing a further embodiment of the invention;

[0033] FIG. 9 is a front view of the tailpipe shown in FIG. 8;

[0034] FIG. 10 is a view looking in direction of arrows X in FIG. 9; and

[0035] FIG. 11 is a sectional view in a direction of arrows XI in FIG. 9.

DESCRIPTION OF EMBODIMENTS

[0036] Embodiments of the invention will be described in conjunction with the drawings.

[0037] FIGS. 4-7 show an embodiment of the invention in which parts same as those in FIGS. 1-3 are represented by same reference numerals. In the embodiment illustrated, a curved shape is employed just like the conventional example shown in FIGS. 1-3 such that direct water hammer does not affect deep upon high-pressure washing of a vehicle body. A partition 5 is mounted on an inner periphery of a curved portion 1a outward of a curved direction such that the partition 5 is gradually spaced apart from the inner periphery toward downstream in a direction of flow of exhaust gas 3 to thereby define a dead end portion 6 between the partition 5 and the inner periphery of the curved portion 1a outward of the curved direction.

[0038] In this case, the curved portion 1a is distended outward of the curved direction such that, in a condition without the partition 5, a flow passage cross-sectional area at a defined position of the dead end portion 6 is larger than that upstream of the curved portion 1a. Especially in the embodiment, the partition 5 is provided in a position relationship as if it were along a contour of the curved portion 1a of the conventional tailpipe 1 (see FIGS. 1-3) outward of the curved direction to thereby define the dead end portion 6 by the distended portion outward of the curved direction of the partition 5.

[0039] It is ensured that the flow passage cross-sectional area decreased by the partition 5 is larger than the opening cross-sectional area of the outlet 4 of the tailpipe 1. Thus, in the embodiment, with the partition 5 being added, ensured is a flow passage space substantially similar to that in the conventional example shown in FIGS. 1-3.

[0040] Arranged at a deep position upstream of the curved portion 1a of the tailpipe 1 is a sensor 2 for concentration-detection of particulates or particulate matter (PM) which can ascertain whether the particulates is properly reduced or not by a particulate filter (not shown) arranged further upstream.

[0041] Even if the washing water is sprayed toward the outlet 4 of the tailpipe 1 as shown by arrows W in FIGS. 6 and 7 upon high-pressure washing of the vehicle body, owing to the structure, the washing water linearly ingressed through the outlet 4 flows along the inner periphery of the curved portion 1a, outward of the curved direction, of the tailpipe 1 and impinges on and is dammed by the dead end portion 6 defined by the partition 5. Any splash upon the impingement is rebounded by the partition 5 overlying. Thus, the ingress of the washing water into a deep position in the tailpipe 1 upon high-pressure washing of the vehicle body can be prevented.

[0042] The partition 5 in the tailpipe 1 is arranged to be gradually spaced apart from the inner periphery of the curved portion 1a outward of the curved direction toward downstream in the direction of flow of the exhaust gas 3 so that the flow of the exhaust gas 3 can be smoothly guided without hardship in the curved direction of the curved portion 1a, thereby preliminarily preventing excessive pressure loss in the flow of the exhaust gas 3.

[0043] Especially, in the embodiment, the curved portion 1a is distended outward of the curved direction such that, in the condition without the partition 5, the flow passage cross-sectional area at the defined position of the dead end portion 6 is greater than that upstream of the curved portion 1a. This causes no excessive decrease in the flow passage cross-sectional area of the tailpipe 1 by the addition of the partition 5 and can ensure the dead end portion 6 large in size for damming the ingress of the washing water. Moreover, it is ensured that the flow passage cross-sectional area decreased by the partition 5 is larger than an opening cross-sectional area of the outlet 4 of the tailpipe 1, which can substantially suppress pressure loss in the flow of the exhaust gas 3 by the addition of the partition 5.

[0044] Thus, the above embodiment can prevent the ingress of the washing water to the deep position in the tailpipe 1 upon high-pressure washing of the vehicle body, so that the sensor 2, when arranged upstream of the curved portion 1a of the tailpipe 1, can be protected from the washing water. Moreover, responsiveness in detection by the sensor 2 can be kept high since there is no need of a sensing element of the sensor 2 being covered with a splash-preventive cover.

[0045] The fact that the curved portion 1a is distended outward of the curved direction such that, in the condition without the partition 5, the flow passage cross-sectional area at the defined position of the dead end portion 6 is greater than that upstream of the curved portion 1a can preliminarily prevent substantial increase in pressure loss due to excessive decrease of the flow passage cross-sectional area of the tailpipe 1 by the addition of the partition 5 and can increase in size the dead end portion 6 to dam more reliably the ingress of the washing water.

[0046] The fact that the flow passage cross-sectional area decreased by the partition 5 is ensured to be greater than the opening cross-sectional area of the outlet 4 of the tailpipe 1 can substantially suppress pressure loss in the flow of the exhaust gas 3 by the addition of the partition 5 to maintain exhaust performance as usual despite of the addition of the partition 5.

[0047] FIGS. 8-11 shows a further embodiment of the invention. In the embodiment illustrated, just like the conventional example shown in FIGS. 1-3, a curved shape is employed such that direct water hammer does not affect deep upon high-pressure washing of a vehicle body. A drainage opening 7 is opened at a position of a curved portion 1a outward of a curved direction and opposite to an outlet 4 of a tailpipe 1. A cover 9 is arranged to cover, in a spaced apart relationship, an outer periphery of the curved portion 1a outward of the curved direction so as not to block the drainage opening 7 and extends upstream in a scroll shape from a downstream end of the drainage opening 7 to provide a drainage port 8 upstream of the drainage opening 7.

[0048] Especially, in the embodiment, the curved shape is vertically imparted to the tailpipe 1 such that the flow of exhaust gas 3 from upward to downward is curved into a horizontal direction and is directed to the outlet 4. The curved portion 1a is flattened toward the outlet 4 of the tailpipe 1 to gradually decrease the flow passage cross-sectional area, whereby the ambient air can be taken through the drainage port 8 due to an effect of reduced pressure resulting from increase in flow rate of the exhaust gas 3 to the outlet 4.

[0049] Arranged at a deep position of the tailpipe 1 upstream of the curved portion 1a is a sensor 2 for concentration-detection of particulates or particulate matter (PM). Arranged further upstream is a particulate filter (not shown) which ascertains whether the particulates are properly reduced or not.

[0050] Then, even if the washing water is sprayed to the outlet 4 of the tailpipe 1 as shown by arrows W in FIGS. 10 and 11 upon high-pressure washing of the vehicle body, owing to the structure, the washing water linearly ingressed through the outlet 4 passes through the drainage opening 7 to the inner periphery of the cover 9, flows along the inner periphery of the cover 9 between the same and the outer periphery of the tailpipe 1 and is discharged outside of the tailpipe 1 through the drainage port 8 substantially away from the outlet 4, which prevents ingress of the washing water to a deep position in the tailpipe 1 upon high-pressure washing of the vehicle body.

[0051] In this case, since the cover 9 extends upstream in the scroll shape from the downstream end of the drainage opening 7, the washing water linearly ingressed through the outlet 4 of the tailpipe 1 smoothly flows along the inner periphery of the tailpipe 1 outward of the curved direction as well as the inner periphery of the cover 9, which are continuous surfaces without steps, and readily reaches and is discharged through the drainage port 8 without greatly losing power, thereby preliminarily preventing a situation that great splash is caused by violent impingement of the washing water against wall surfaces.

[0052] The drainage opening 7 of the tailpipe 1 is covered with the cover 9 to prevent ingress of the washing water and the splash and the drainage port 8 defined by the cover 9 is opened at the position substantially spaced apart upstream from the outlet 4 of the tailpipe 1. Thus, even in the situation of the ingress of the washing water into the outlet 4 of the tailpipe 1 upon the high-pressure washing, the ingress to the drainage port 8 is hard to occur; even if the ingress of the washing water into the drainage port 8 is caused, there is no fear that the washing water then flows round toward upstream again through the downstream drainage opening 7.

[0053] Especially, in the embodiment, the curved shape is vertically imparted to the tailpipe 1 such that the flow of the exhaust gas 3 from upward to downward is curved into the horizontal direction and is directed to the outlet 4, so that the washing water remaining in the cover 9 at the end of the high-pressure washing flows down due to gravity and is certainly discharged through the outlet 4.

[0054] Moreover, the flow passage cross-sectional area of the curved portion is gradually reduced toward the outlet 4 of the tailpipe 1 such that the ambient air can be taken into the tailpipe 1 through the drainage port 8 due to the effect of reduced pressure resulting from the increase in flow rate of the exhaust gas 3 to the outlet 4, so that the ambient air is taken through the drainage port 8 as the exhaust gas 3 flows through the tailpipe 1; such admixing of the ambient air lowers a temperature of the exhaust gas 3.

[0055] Thus, according to the above-mentioned embodiment, the ingress of the washing water to a deep position of the tailpipe 1 upon high-pressure washing of vehicle body can be prevented so that the sensor 2, when arranged upstream of the curved portion 1a of the tailpipe 1, can be protected from the washing water. Moreover, there is no need of a sensing element of the sensor 2 being covered with a splash-preventive cover, which can maintains high responsiveness in detection by the sensor 2.

[0056] At an end of the high-pressure washing, the washing water remaining in the cover 9 flows down due to gravity and can be reliably discharged through the outlet 4 of the tailpipe 1 so that production of rust and the like due to remaining of the washing water in the tailpipe 1 can be preliminarily prevented. Moreover, the ambient air can be taken through the drainage port 8 into mixing with the exhaust gas 3 as the exhaust gas 3 flows through the tailpipe 1, thereby decreasing the temperature of the exhaust gas 3. This can enhance safeness against, for example, pedestrians passing by the outlet 4 of the tailpipe 1 during stop of the vehicle.

[0057] It is to be understood that the water ingress prevention structure for the tailpipe according to the invention is not limited to the above embodiments and that various changes and modifications may be made without departing from the scope of the invention. For example, the exhaust emission control device upstream of the tailpipe is not restricted to that with the particulate filter and the selective reduction catalyst arranged in parallel with each other. The sensor on the tailpipe is not restricted to the sensor for the particulates or particulate matter (PM).

REFERENCE SIGNS LIST

[0058] 1 tailpipe [0059] 1a curved portion [0060] 3 exhaust gas [0061] 4 outlet [0062] 5 partition [0063] 6 dead end portion [0064] 7 drainage opening [0065] 8 drainage port [0066] 9 cover