Arrangement structure for exhaust pressure detector

Abstract

To provide an arrangement structure for an exhaust pressure detector capable of preventing freezing of a pressure sensor that detects exhaust pressure and preventing wrong detection of the pressure sensor.SOLUTION: A thermostat case 45 in which cooling water for cooling an engine body 22A flows is provided at an end part in a vehicle width direction of the engine body 22A. A pressure sensor 46 is disposed at a position that is overlapped with the thermostat case 45 in front view of a vehicle 1 and that is on the rear side of the thermostat case 45. A cooling water outlet 22B in which the cooling water is discharged from the engine body 22A is provided at an end part on the rear side and in the vehicle width direction of the engine body 22A. The thermostat case 45 is mounted to the cooling water outlet 22B. The pressure sensor 46 is mounted to the thermostat case 45.SELECTED DRAWING: Figure 1

Description

[Technical field]

[0001] The present invention relates to an arrangement structure of an exhaust pressure detection device. [Background technology]

[0002] Patent Document 1 describes an exhaust purification device for an internal combustion engine, which includes a substantially cylindrical case member that houses a DPF (diesel particulate filter), a differential pressure sensor that detects a differential pressure before and after the DPF, and a differential pressure pipe that connects an exhaust passage near the DPF to the differential pressure sensor. In Patent Document 1, the case member is a case half that is divided into two in the circumferential direction and is integrated by welding at an extension portion, and the differential pressure pipe is arranged along the outer circumferential surface of the case member and has an exposed curved portion and outer circumferential portion, and the exposed curved portion and outer circumferential portion are arranged along the outer circumferential surface of the case member on the vehicle rear side and are arranged on the vehicle rear side of the nearest extension portion among a plurality of extension portions adjacent in the circumferential direction. In addition, the differential pressure sensor is arranged above the front side of the engine. [Prior art documents] [Patent documents]

[0003] [Patent Document 1] Patent No. 6120825 Summary of the Invention [Problem to be solved by the invention]

[0004] However, in the conventional technology described in Patent Document 1, although it is possible to prevent the wind from directly hitting the differential pressure pipe, the pressure sensor (differential pressure sensor) is installed at the front of the vehicle, so when the temperature is low, such as when driving in below-freezing temperatures, the wind will hit the pressure sensor, causing condensation water to freeze inside the pressure sensor, which may make it impossible to measure the pressure properly.

[0005] The present invention has been made in consideration of the above-mentioned circumstances, and has an object to provide an arrangement structure for an exhaust pressure detection device that can prevent the pressure sensor that detects exhaust pressure from freezing and can prevent erroneous detection by the pressure sensor. [Means for solving the problem]

[0006] The present invention is an arrangement structure of an exhaust pressure detection device comprising an engine body arranged in an engine compartment at the front of a vehicle, an exhaust pipe attached to the front side of the engine body, a filter provided in the exhaust pipe for collecting particulate matter in the exhaust gas, and a pressure sensor for detecting through a pressure transmission pipe the differential pressure between the exhaust pressure upstream of the filter in the exhaust pipe and the exhaust pressure downstream of the filter, characterized in that a cooling device through which cooling water for cooling the engine body flows is provided at the end of the engine body in the vehicle width direction, and the pressure sensor is arranged in a position overlapping with the cooling device when viewed from the front of the vehicle and rearward of the cooling device. Effect of the Invention

[0007] As described above, according to the present invention, it is possible to provide an arrangement structure for an exhaust pressure detection device that can prevent the pressure sensor that detects the exhaust pressure from freezing and can prevent erroneous detection by the pressure sensor. [Brief description of the drawings]

[0008] [Figure 1] FIG. 1 is a side view of the front part of a vehicle equipped with an exhaust pressure detection device arrangement structure according to one embodiment of the present invention. [Diagram 2] FIG. 2 is a rear view of the front part of a vehicle equipped with an exhaust pressure detection device arrangement structure according to one embodiment of the present invention. DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS

[0009] An exhaust pressure detection device arrangement structure according to one embodiment of the present invention includes an engine body arranged in an engine compartment at the front of a vehicle, an exhaust pipe attached to the front side of the engine body, a filter provided in the exhaust pipe for collecting particulate matter in the exhaust gas, and a pressure sensor for detecting, through a pressure transmission pipe, a differential pressure between the exhaust pressure upstream of the filter in the exhaust pipe and the exhaust pressure downstream of the filter, characterized in that a cooling device through which cooling water for cooling the engine body flows is provided at an end of the engine body in the vehicle width direction, and the pressure sensor is arranged at a position overlapping with the cooling device and rearward of the cooling device when viewed from the front of the vehicle. As a result, the exhaust pressure detection device arrangement structure according to one embodiment of the present invention can prevent the pressure sensor for detecting the exhaust pressure from freezing and can prevent erroneous detection by the pressure sensor. EXAMPLES

[0010] DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS An arrangement and structure of an exhaust pressure detection device according to an embodiment of the present invention will now be described with reference to the drawings.

[0011] 1 and 2 are diagrams showing the layout structure of an exhaust pressure detection device according to an embodiment of the present invention. In Fig. 1 and Fig. 2, the up / down, front / rear, left / right directions refer to the front / rear direction of the vehicle, the left / right direction of the vehicle (vehicle width direction), and the up / down direction of the vehicle (vehicle height direction).

[0012] 1, a front grille 4 is provided at the front end of a vehicle 1. An engine room 21 surrounded by the front grille 4, a bonnet 2, a dash panel 3, etc. is formed at the front of the vehicle 1.

[0013] An engine 22 is installed in the engine compartment 21. A front grille 4 covers the engine 22 from the front, and a bonnet 2 covers the engine 22 from above. In addition, a dash panel 3 covers the engine 22 from the rear.

[0014] The engine 22 includes an engine body 22A and auxiliary machinery. The engine body 22A includes a cylinder block 23, a cylinder head 24 connected to the upper part of the cylinder block 23, a cylinder head cover 25 connected to the upper part of the cylinder head 24, and an oil pan 26 connected to the lower part of the cylinder block 23.

[0015] Cylinder block 23 is provided with a plurality of cylinders (not shown). Pistons (not shown) are housed in the cylinders and reciprocate vertically relative to the cylinders. The pistons are connected to a crankshaft (not shown) via connecting rods (not shown), and the reciprocating motion of the pistons is converted into rotational motion of the crankshaft via the connecting rods. Engine 22 is arranged horizontally in engine room 21 so that the plurality of cylinders are aligned in the width direction of vehicle 1.

[0016] The cylinder head 24 is provided with a plurality of intake ports, a plurality of intake valves for opening and closing the intake ports, a plurality of exhaust ports, and a plurality of exhaust valves for opening and closing the exhaust ports, all of which are not shown. The cylinder head 24 is also provided with an intake camshaft for opening and closing the intake valves, and an exhaust camshaft for opening and closing the exhaust valves.

[0017] An intake port (not shown) is opened on the rear surface of the cylinder head 24, and an intake manifold (not shown) is connected to this intake port.

[0018] An integrated exhaust manifold (not shown) is formed inside the cylinder head 24. An exhaust port (not shown) is opened in the front of the cylinder head 24, and an exhaust pipe 41 is attached to this exhaust port. The exhaust pipe 41 extends downward on the front side of the engine body 22A.

[0019] A GPF (Gasoline Particulate Filter) 43 serving as a filter for collecting particulate matter in exhaust gas is provided in the exhaust pipe 41. The GPF 43 is disposed in the exhaust pipe 41 at a position on the front side of a lower portion of the engine body 22A.

[0020] A pressure transmission pipe 47A is connected to the exhaust pipe 41 at a position upstream of the GPF 43. A pressure transmission pipe 47B is connected to the exhaust pipe 41 at a position downstream of the GPF 43.

[0021] The engine 22 is equipped with a pressure sensor 46 as an exhaust pressure detection device, and this pressure sensor 46 is connected to pressure transmission pipes 47A and 47B. The pressure sensor 46 detects the differential pressure between the exhaust pressure upstream of the GPF 43 and the exhaust pressure downstream of the GPF 43 through the pressure transmission pipes 47A and 47B.

[0022] The front grille 4 has a grill opening 4A, and a running wind is introduced through the grill opening 4A into the engine compartment 21. Here, the running wind refers to the air flow generated when the vehicle 1 is running and that air.

[0023] A radiator 42 is disposed behind the front grill 4 and in front of the engine body 22A in the engine compartment 21. The radiator 42 cools the coolant by heat exchange with air introduced into the engine compartment 21.

[0024] A fan shroud 42A is disposed on the rear surface of the radiator 42. An electric cooling fan (not shown) is housed in the fan shroud 42A. The electric cooling fan operates when the temperature of the cooling water reaches or exceeds a threshold value, and blows air in front of the radiator 42 rearward.

[0025] The radiator 42 is connected to the engine 22 via an inlet pipe 42B that introduces high-temperature cooling water from the engine body 22A, and an outlet pipe 42C that returns the cooling water to the engine body 22A after cooling. The inlet pipe 42B and the outlet pipe 42C are mostly made of metal, and partially made of rubber.

[0026] The outlet pipe 42C is connected to the right end of the lower part of the radiator 42. The outlet pipe 42C extends diagonally upward and rearward to the left of the exhaust pipe 41, extends rearward along the upper surface of the transmission 30, and extends rightward at the rear surface of the engine body 22A. The downstream end of the outlet pipe 42C is connected to a water pump (not shown) that is arranged at the right end of the lower part of the engine body 22A.

[0027] The inlet pipe 42B is connected to the left end of the upper part of the radiator 42. The inlet pipe 42B passes to the left of the exhaust pipe 41 and extends rearward.

[0028] A thermostat case 45 through which coolant for cooling the engine body 22A flows is provided at the left end in the vehicle width direction of the engine body 22A. A coolant outlet 22B through which the coolant is discharged from the engine body 22A is provided at the rear of the engine body 22A and at the left end in the vehicle width direction. This coolant outlet 22B discharges the coolant that has cooled the engine body 22A and become high temperature.

[0029] The thermostat case 45 is attached to the cooling water outlet 22B. A thermostat (not shown) is housed inside the thermostat case 45. The thermostat case 45 constitutes the cooling device of the present invention. An inlet pipe 42B is connected to the thermostat case 45.

[0030] When the temperature of the cooling water at the cooling water outlet 22B rises above a predetermined temperature, the thermostat inside the thermostat case 45 opens, and the cooling water circulates between the radiator 42 and the engine body 22A via the inlet pipe 42B and the outlet pipe 42C.

[0031] A side case 33 is provided at the left end of the engine body 22A in the vehicle width direction. A sensor for detecting the rotation of the camshaft is attached inside the side case 33. The side case 33 is disposed above and behind the thermostat case 45. The side case 33 covers the pressure sensor 46 from above.

[0032] As shown in FIG. 2, in a rear view of the vehicle, the pressure sensor 46 is disposed at a position behind the thermostat case 45, and is covered by the thermostat case 45 from the front.

[0033] Therefore, the pressure sensor 46 is disposed at a position overlapping with the thermostat case 45 in a front view of the vehicle and at a position rearward of the thermostat case 45. In other words, the pressure sensor 46 is disposed at a position rearward of the thermostat case 45 and hidden by the thermostat case 45 in a front view of the vehicle.

[0034] 1 and 2, pressure sensor 46 is attached to thermostat case 45. More specifically, pressure sensor 46 has legs 46A, which are fixed to thermostat case 45. In this manner, pressure sensor 46 is supported by thermostat case 45 via legs 46A. Legs 46A are made of a material with excellent heat conductivity, such as metal.

[0035] Since the pressure sensor 46 is attached to the thermostat case 45, the pressure sensor 46 can receive heat from the thermostat case 45, which is warmed by high-temperature cooling water, via the legs 46A. Also, since most of the inlet pipe 42B is made of metal, the pressure sensor 46 can receive heat via the air warmed by the inlet pipe 42B. Also, the pressure transmission pipes 47A and 47B are routed along the inlet pipe 42B. Therefore, the pressure transmission pipes 47A and 47B can receive heat via the air warmed by the inlet pipe 42B.

[0036] Next, the operation will be described. As shown by arrow A1 in Fig. 1, airflow from the vehicle 1 is drawn into the engine compartment 21 through the grill opening 4A of the front grill 4. When the temperature is low, such as when the vehicle is traveling below freezing, the airflow drawn into the engine compartment 21 is at a low temperature.

[0037] In this embodiment, a thermostat case 45 through which cooling water for cooling the engine body 22A flows is provided at the end of the engine body 22A in the vehicle width direction, and the pressure sensor 46 is positioned behind the thermostat case 45 in a position overlapping with the thermostat case 45 when viewed from the front of the vehicle 1.

[0038] As a result, the airflow introduced into engine compartment 21 hits thermostat case 45 in front of pressure sensor 46, and then changes direction and flows rearward away from thermostat case 45 as indicated by arrows A2 and A3.

[0039] Therefore, by disposing the pressure sensor 46 at the rear and behind the thermostat case 45, the thermostat case 45 in front of the pressure sensor 46 functions as a windbreak member (wind shield member) and prevents the low-temperature air caused by traveling from directly hitting the pressure sensor 46. As a result, the pressure sensor 46 that detects the exhaust pressure can be prevented from freezing, and erroneous detection by the pressure sensor 46 can be prevented.

[0040] Furthermore, since the side case 33 is disposed above and behind the thermostat case 45, the side case 33 also functions as a windbreak member, which further prevents the pressure sensor 46 from freezing and prevents erroneous detection by the pressure sensor 46.

[0041] In this embodiment, a cooling water outlet 22B through which cooling water is discharged from the engine body 22A is provided at the rear end in the vehicle width direction of the engine body 22A, and the thermostat case 45 is attached to the cooling water outlet 22B.

[0042] As a result, the thermostat case 45 is warmed by high-temperature (e.g., 70°C to 90°C) coolant flowing out from the engine body 22A via the coolant outlet 22B. Therefore, the pressure sensor 46 receives heat from the thermostat case 45, which prevents the pressure sensor 46 from freezing and erroneous detection by the pressure sensor 46.

[0043] In this embodiment, a pressure sensor 46 is attached to the thermostat case 45 .

[0044] This allows the pressure sensor 46 to directly receive heat from the cooling water flowing through the thermostat case 45. This makes it possible to more effectively prevent the pressure sensor 46 from freezing, and thus to prevent the pressure sensor 46 from making erroneous detections.

[0045] Although an embodiment of the invention has been disclosed, it will be apparent to one of ordinary skill in the art that modifications may be made therein without departing from the spirit and scope of the invention, and it is intended that all such modifications and equivalents be included in the following claims. [Explanation of symbols]

[0046] 1...vehicle, 21...engine compartment, 22A...engine body, 22B...cooling water outlet, 41...exhaust pipe, 43...GPF (filter), 45...thermostat case (cooling device), 46...pressure sensor, 47A, 47B...pressure transmission pipe

Claims

1. An engine body disposed in an engine compartment at the front of the vehicle; an exhaust pipe attached to a front side of the engine body; a filter provided in the exhaust pipe for collecting particulate matter in the exhaust gas; a pressure sensor that detects a differential pressure between an exhaust pressure upstream of the filter in the exhaust pipe and an exhaust pressure downstream of the filter through a pressure transmission pipe, a cooling device through which cooling water for cooling the engine body flows is provided at an end of the engine body in a vehicle width direction, 13. An exhaust pressure detection device according to claim 12, wherein the pressure sensor is disposed at a position overlapping with the cooling device in a front view of the vehicle and at a position rearward of the cooling device.

2. a cooling water outlet through which cooling water is discharged from the engine body is provided at a rear end of the engine body in a vehicle width direction; 2. The exhaust pressure detection device according to claim 1, wherein the cooling device is attached to the cooling water outlet.

3. 3. The arrangement of an exhaust pressure detection device according to claim 1, wherein the pressure sensor is attached to the cooling device.

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