Internal combustion engine

Abstract

To provide an internal combustion engine capable of measuring an exhaust temperature appropriately.SOLUTION: An internal combustion engine comprises: an exhaust manifold 4 having a plurality of introduction ports 6 through which exhaust gas is introduced from an exhaust port, a body part 7 in which the exhaust gas introduced from the plurality of introduction ports 6 temporarily gathers, a delivery port 10 that sends out the exhaust gas in the body part 7 toward an exhaust gas recirculation device 9, and a discharge port 12 that discharges the exhaust gas in the body part 7 to an exhaust passage 11; and an exhaust temperature sensor 5 provided in the exhaust manifold 4. The plurality of introduction ports 6 are arranged side by side in a first direction. The delivery port 10 is arranged so as to be adjacent to one of the plurality of introduction ports 6 in the first direction. The exhaust outlet 12 is arranged so as to face at least one of the plurality of introduction ports 6. The exhaust temperature sensor 5 is provided so as to be biased toward the delivery port 10 side with respect to a central position c of a formation area A, which is an area of the exhaust manifold 4 in the first direction in which the plurality of introduction ports 6 and the delivery port 10 are formed.SELECTED DRAWING: Figure 2

Description

Technical Field

[0001] This invention relates to an internal combustion engine.

Background Art

[0002] The temperature of the exhaust gas exhausted from an internal combustion engine serves as an indicator of whether the combustion state is normal. Therefore, an exhaust temperature sensor is provided inside an exhaust manifold or the like to measure the exhaust temperature. For example, in the internal combustion engine shown in Patent Document 1 below, a temperature sensor is provided near the outlet of an exhaust manifold where the exhaust gases discharged from each cylinder merge, and the exhaust temperature is measured (see FIG. 1 of Patent Document 1 below).

Prior Art Documents

Patent Documents

[0003]

Patent Document 1

Summary of the Invention

Problems to be Solved by the Invention

[0004] In order to accurately measure the exhaust gas temperature with a temperature sensor, it is necessary for the exhaust gas to directly hit the sensor and for there to be a sufficient exhaust gas flow rate. In the configuration according to Patent Document 1, since the temperature sensor is provided near the outlet of the exhaust manifold, the exhaust gas directly hits this temperature sensor and a sufficient exhaust gas flow rate is obtained. However, due to the continuous impact of the large-flow exhaust gas collected from a plurality of cylinders (in this patent document, four cylinders), there is a risk that the temperature sensor will overheat and malfunctions such as failures will occur.

[0005] Therefore, an object of this invention is to provide an internal combustion engine capable of appropriately measuring the exhaust temperature.

Means for Solving the Problems

[0006] In order to solve the above problems, this invention provides: An exhaust manifold having multiple inlets connected to each exhaust port of multiple cylinders, into which exhaust gas from the exhaust ports is introduced; a main body into which the exhaust gas introduced from the multiple inlets is temporarily collected; an outlet that sends the exhaust gas from the main body toward an exhaust gas recirculation device; and an outlet that discharges the exhaust gas from the main body toward an exhaust passage. The exhaust manifold includes an exhaust temperature sensor, The plurality of inlets are arranged in a line in the first direction, the outlets are arranged adjacent to one of the plurality of inlets in the first direction, and the discharge ports are arranged facing at least one of the plurality of inlets. The exhaust temperature sensor is positioned in the exhaust manifold, offset towards the outlet side from the center of the forming region, which is the region in the first direction where the plurality of inlets and outlets are formed, in the internal combustion engine.

[0007] In the above configuration, It is preferable that the exhaust temperature sensor is positioned so as to face the inlet that is closest to the outlet among the plurality of inlets.

[0008] In all of the above configurations, It is preferable that the exhaust temperature sensor is provided on the side of the multiple inlet ports, passing through an intermediate position in the size of the main body in a direction perpendicular to the first direction, and on the extension line extending toward the first direction.

[0009] In all of the above configurations, In the first direction, it is preferable that the center of the discharge port is located on the opposite side of the discharge port with respect to the central position of the forming region.

[0010] In all of the above configurations, It is preferable that the size of the main body in the direction perpendicular to the first direction decreases as you move along the first direction from the outlet side to the discharge side.

[0011] In all of the above configurations, The internal combustion engine is mounted on the vehicle such that the plurality of cylinders are arranged in the longitudinal direction of the vehicle, and it is preferable that the outlet is located behind the plurality of inlets. [Effects of the Invention]

[0012] In this invention, the exhaust temperature sensor provided in the exhaust manifold is positioned off-center towards the outlet side within the forming region. This ensures a predetermined amount of exhaust gas flow directly hitting the sensor while preventing the temperature from becoming too high due to direct contact with large volumes of exhaust gas from all cylinders, thereby enabling accurate measurement of the exhaust temperature. [Brief explanation of the drawing]

[0013] [Figure 1] This is a bottom view showing one embodiment of the internal combustion engine according to this invention when it is mounted in a vehicle. [Figure 2] This is a cross-sectional view showing one embodiment of an internal combustion engine according to the present invention. [Modes for carrying out the invention]

[0014] An embodiment of the internal combustion engine 1 according to this invention will be described based on the drawings. As shown in Figure 1, this internal combustion engine 1 is a four-cylinder in-line engine (hereinafter referred to as the engine, and denoted by the same reference numerals as the internal combustion engine 1) mounted on a vehicle 2, with the first cylinder 3a to the fourth cylinder 3d arranged in series. This engine 1 is a longitudinally mounted engine 1 in which the first cylinder 3a is located at the front of the vehicle 2 and the fourth cylinder 3d is located at the rear of the vehicle 2. As shown in Figure 2, the engine 1 mainly consists of an exhaust manifold 4 and an exhaust temperature sensor 5 provided in the exhaust manifold 4.

[0015] The exhaust manifold 4 has a plurality of inlet ports 6 (four in this embodiment) arranged in a first direction (in this embodiment, the vehicle's front-rear direction) into which exhaust gas from the engine 1, i.e., multiple cylinders 3a, 3b, 3c, and 3d is introduced; a main body 7 into which the exhaust gas introduced from the plurality of inlet ports 6 temporarily collects; an outlet port 10 that sends the exhaust gas in the main body 7 toward an exhaust gas recirculation device 9 that introduces the exhaust gas into the intake system 8; and an outlet port 12 that discharges the exhaust gas in the main body 7 toward the exhaust passage 11.

[0016] The inlet 6 is connected to each exhaust port (not shown) of the engine 1, which has cylinders 1a to 4d. Hereinafter, the inlet 6 connected to the exhaust port of cylinder 1a will be referred to as the first inlet 6a, the inlet 6 connected to the exhaust port of cylinder 2b will be referred to as the second inlet 6b, the inlet 6 connected to the exhaust port of cylinder 3c will be referred to as the third inlet 6c, and the inlet 6 connected to the exhaust port of cylinder 4d will be referred to as the fourth inlet 6d. Note that the number of cylinders of engine 1 is not limited to 4, and can be applied to, for example, a 3-cylinder engine, a 6-cylinder engine, etc. In this embodiment, each passage extending from the part connected to the exhaust port of each cylinder 3a, 3b, 3c, 3d to the main body 7 will also be treated as an inlet 6.

[0017] The main body 7 is a hollow portion that extends in the width direction (first direction), which is from the first inlet 6a to the fourth inlet 6d, and in the length direction (vehicle width direction), which is perpendicular to the width direction and is the direction in which the main exhaust flows. The first inlet 6a to the fourth inlet 6d and the outlet 10 are provided at one end of the main body 7 in the length direction, and the discharge port 12 is provided at the other end of the main body 7 in the length direction. The size of the main body 7 in the length direction gradually decreases along the first direction from the discharge port 12 side to the inlet 10 side (towards the rear).

[0018] The delivery port 10 is arranged adjacent to the opposite side of the third inlet port 6c of the fourth inlet port 6d along the arrangement of the plurality of inlet ports 6 (the first inlet port 6a to the fourth inlet port 6d) in the first direction. That is, the delivery port 10 is arranged adjacent to the inlet port 6 located at the outermost end in the first direction on the outer side in the first direction (the rear of the vehicle in this embodiment). The delivery port 10 is connected to an exhaust gas recirculation device 9 formed in the cylinder head of the engine 1, and exhaust gas is recirculated to the intake system 8 through this exhaust gas recirculation device 9. Hereinafter, the region in which the plurality of inlet ports 6 (the first inlet port 6a to the fourth inlet port 6d) and the delivery port 10 are formed side by side in the first direction is referred to as a formation region (the region indicated by the arrow A in FIG. 2), and the central position in the first direction of this formation region A is referred to as the central position c of the formation region A.

[0019] The discharge port 12 faces the plurality of inlet ports 6 (the first inlet port 6a to the fourth inlet port 6d), and the center of the discharge port 12 is arranged on the opposite side of the delivery port 10 with respect to the central position c of the formation region A (the front of the vehicle in this embodiment). In this embodiment, the third inlet port 6c is approximately at the central position c of the formation region A, and the center of the discharge port 12 is located between the second inlet port 6b and the third inlet port  6c. The exhaust gas discharged from the discharge port 12 is sent to the exhaust passage 11.

[0020] The exhaust temperature sensor 5 is provided biased toward the delivery port 10 side from the central position c of the formation region A in the first direction. More specifically, it is provided so as to face the fourth inlet port 6d, which is the closest to the delivery port 10 among the plurality of inlet ports 6 (the first inlet port 6a to the fourth inlet port 6d). Further, this exhaust temperature sensor 5 is provided offset toward the inlet port 6 side (the fourth inlet port 6d side in this embodiment) from an extension line e that passes through the central position of the length direction size t of the main body portion 7 and extends in the first direction (refer to the arrow s in FIG. 2). Note that the central position of the length direction size t of the main body portion 7 means the center of the distance from one end to the other end in the length direction of the main body portion 7.

[0021] The exhaust gas introduced into the main body 7 from the first inlet 6a, second inlet 6b, and third inlet 6c, which are close to the discharge port 12, is discharged directly from the discharge port 12 in larger quantities than the amount that flows toward the fourth inlet 6d and the outlet 10 (see arrows f1 to f3 in Figure 2). On the other hand, the exhaust gas introduced into the main body 7 from the fourth inlet 6d flows in a manner that branches appropriately in both directions, toward the discharge port 12 and toward the outlet 10, because the outlet 10 is formed right next to it (see arrows f4 and f4' in Figure 2).

[0022] In particular, in the above embodiment, since the outlet 10 is formed next to the fourth inlet 6d, unlike the case where there is no outlet 10 (when the wall of the main body 7 is located), the pressure does not rise locally near the fourth inlet 6d inside the main body 7, which is preferable in terms of measurement sensitivity.

[0023] In the above-described internal combustion engine 1, the exhaust temperature sensor 5 is positioned towards the outlet 10 side of the central position c of the forming region A, with multiple inlets 6 (first inlet 6a to fourth inlet 6d) and outlet 10 arranged in a first direction. This ensures a predetermined amount of exhaust gas flow directly to the exhaust temperature sensor 5 while preventing the large flow rate of exhaust gas from all cylinders from directly hitting the exhaust temperature sensor 5 and causing it to overheat, thereby enabling appropriate measurement of the exhaust temperature. In this embodiment, "exhaust gas directly hitting the exhaust temperature sensor 5" means that the exhaust gas flowing from the inlet 6 towards the outlet 12 hits the exhaust temperature sensor 5.

[0024] In particular, in the above embodiment, the exhaust temperature sensor 5 is positioned opposite the fourth inlet 6d, which is closest to the outlet 10, among the multiple inlets 6. Therefore, high measurement accuracy can be obtained by introducing exhaust gas at an appropriate flow rate through this fourth inlet 6d.

[0025] Furthermore, in the internal combustion engine 1 described above, the exhaust temperature sensor 5 is positioned opposite the fourth inlet 6d, passing through the center of the length t of the main body 7 in a direction perpendicular to the first direction, and offset toward the fourth inlet 6d side from the extension line e extending toward the first direction. As a result, the exhaust gas introduced from the fourth inlet 6d is reliably received by the exhaust temperature sensor 5, while the exhaust gas flowing from the first inlet 6a, second inlet 6b, and third inlet 6c towards the outlet 10 side is more likely to pass toward the outlet 12 side in the length direction of the main body 7 than the exhaust temperature sensor 5. Therefore, the flow rate of exhaust gas hitting the exhaust temperature sensor 5 can be optimized, and the exhaust temperature can be measured with high accuracy.

[0026] Furthermore, in the first direction, the internal combustion engine 1 is positioned such that the center of the outlet 12 is located on the opposite side of the outlet 10 with respect to the central position c of the forming region A. This prevents a large amount of exhaust gas introduced from each inlet 6 (in this embodiment, the first inlet 6a, the second inlet 6b, and the third inlet 6c) on the opposite side of the outlet 10 from flowing towards the outlet 10, thereby optimizing the exhaust gas flow rate and enabling high-precision measurement of the exhaust temperature.

[0027] In particular, in the above embodiment, the lengthwise size of the main body 7 decreases as it moves from the discharge port 12 towards the outlet port 10. This suppresses the flow of exhaust gas from the first inlet 6a, second inlet 6b, and third inlet 6c towards the fourth inlet 6d, where the lengthwise size of the main body 7 is reduced, thereby preventing large-flow exhaust gas from hitting the exhaust temperature sensor 5.

[0028] Furthermore, in the above-described internal combustion engine 1, the engine 1 is mounted longitudinally in the vehicle 2, and the outlet 10 is located further back in the vehicle than the multiple inlets 6 (first inlet 6a to fourth inlet 6d). As a result, the fourth cylinder 3d side, which is further back, is less cooled than the first cylinder 3a side, which is hit first by the airflow (see the wavy arrow w in Figure 2) that flows through the radiator. Therefore, by placing the exhaust temperature sensor 5 on the fourth cylinder 3d side (outlet 10 side), as in the above embodiment, the exhaust temperature sensor 5 is not excessively cooled by the airflow w, and the accuracy of the exhaust temperature sensor 5 can be ensured.

[0029] The embodiments disclosed herein should be considered in all respects to be illustrative and not restrictive. Accordingly, the scope of the invention is indicated by the claims rather than by the foregoing description, and all modifications within the meaning and scope equivalent to the claims are intended to be included. [Explanation of Symbols]

[0030] 1. Internal combustion engine 2 vehicles 3a Cylinder 1 3b 2nd cylinder 3c Third Cylinder 3d 4th cylinder 4 Exhaust Manifold 5. Exhaust temperature sensor 6 Inlet 6a First Inlet 6b Second Inlet 6c Third Inlet 6d Fourth Inlet 7 Main body 8. Intake System 9. Exhaust gas recirculation device 10 outlet 11 Exhaust passage 12 Outlet A Formation area c (Central position of the forming region) e extension line t (length of the main body)

Claims

1. An exhaust manifold having multiple inlets connected to each exhaust port of multiple cylinders, into which exhaust gas from the exhaust ports is introduced; a main body into which the exhaust gas introduced from the multiple inlets is temporarily collected; an outlet that sends the exhaust gas from the main body toward an exhaust gas recirculation device; and an outlet that discharges the exhaust gas from the main body toward an exhaust passage. The exhaust manifold includes an exhaust temperature sensor, The plurality of inlets are arranged in a line in the first direction, the outlets are arranged adjacent to one of the plurality of inlets in the first direction, and the discharge ports are arranged facing at least one of the plurality of inlets. The exhaust temperature sensor is positioned so as to be offset towards the outlet side of the forming region, which is the region in the first direction where the plurality of inlets and outlets are formed, of the exhaust manifold. An internal combustion engine in which the exhaust temperature sensor is provided so as to face the inlet that is closest to the outlet among the plurality of inlets.

2. The internal combustion engine according to claim 1, wherein the exhaust temperature sensor is provided on the side of the plurality of inlet ports, passing through an intermediate position in the size of the main body in a direction perpendicular to the first direction, and with respect to an extension line extending toward the first direction.

3. The internal combustion engine according to claim 1 or 2, wherein, in the first direction, the center of the outlet is located on the opposite side of the outlet with respect to the central position of the forming region.

4. The internal combustion engine according to claim 1 or 2, wherein the size of the main body in a direction perpendicular to the first direction decreases as it moves from the discharge port side towards the outlet port side along the first direction.

5. The internal combustion engine according to claim 1 or 2, wherein the plurality of cylinders are mounted on the vehicle so as to be arranged in the longitudinal direction of the vehicle, and the outlet is located behind the plurality of inlets.

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