JP2023151362A - internal combustion engine - Google Patents

Abstract

To provide a new configuration capable of contributing to downsizing an internal combustion engine.SOLUTION: An internal combustion engine E according to one embodiment of the present invention comprises: an engine body B compartmentalized into a common intake section 30 which is common to a plurality of cylinders 16 and a plurality of intake branch sections 34 which are branched from a downstream side of the common intake section and extended in a gap between combustion chambers 24 respectively corresponding to the intake branch sections and the common intake section; a throttle body 14 which is connected to the engine body and compartmentalized into an intake passage 14a communicating with the common intake section; and a plurality of injectors 28 which are connected to the engine body and arranged so as to inject fuel into the combustion chambers of the corresponding cylinders respectively.SELECTED DRAWING: Figure 5

Description

The present invention relates to internal combustion engines.

Conventionally, internal combustion engines have been installed in various vehicles. For example, internal combustion engines are installed in straddle-type vehicles such as motorcycles, vehicles capable of traveling on rough terrain such as multi-utility vehicles (MUVs), and four-wheeled vehicles. Patent Document 1 discloses an example of a vehicle called an all-terrain vehicle (ATV) or a side-by-side vehicle, which is frequently used on rough terrain. The vehicle of Patent Document 1 has left and right front wheels, left and right rear wheels, and has left and right front seats and left and right rear seats. A dashboard is placed in front of the front seats, and the area in front of the dashboard covered by the front cover is defined as the front area. The engine of the engine unit is disposed near the center of the vehicle body in the longitudinal direction, and an intake duct connected to a cylinder portion of the engine is connected to an air cleaner. The intake duct has a first pipe part extending in the front-rear direction and a second pipe part connected to the front part of the first pipe part and extending in the vertical direction, so that the air cleaner is disposed in the front area. ing. The air cleaner has an intake port in its upper part that sucks in outside air, and this intake port opens to the right. By opening the intake port in a direction perpendicular to the direction in which the vehicle travels, it is possible to reduce the possibility that dust or the like will be sucked in through the intake port when the vehicle is running.

Furthermore, conventionally, in an internal combustion engine having a plurality of cylinders, that is, a so-called multi-cylinder engine, an intake manifold is connected to a cylinder head in order to distribute intake air to each cylinder (see, for example, Patent Document 2). A throttle valve and an air cleaner may be provided in the intake passage on the upstream side of the intake manifold in this order from the downstream side.

JP2020-108976A Japanese Patent Application Publication No. 2010-048137

Incidentally, in various vehicles such as vehicles capable of traveling on rough terrain, there is a demand for compactly mounting internal combustion engines from various viewpoints such as securing space for passengers. In addition, straddle-type vehicles such as motorcycles are smaller than four-wheeled vehicles and require severe compactness due to the arrangement of parts. The same applies to multi-cylinder internal combustion engines. SUMMARY OF THE INVENTION Therefore, an object of the present invention is to provide a novel configuration that can contribute to downsizing of an internal combustion engine having a plurality of cylinders.

In order to achieve the above object, one aspect of the present invention is to
An internal combustion engine having multiple cylinders,
an intake common part common to the plurality of cylinders; and a plurality of intake branch parts branched downstream of the intake common part, each of which has a plurality of intake branch parts extending between the combustion chamber of a corresponding cylinder and the intake common part. an engine body forming a section with an intake branch;
a throttle body connected to the engine main body and defining an intake passage communicating with the intake common portion;
Provided is an internal combustion engine, comprising a plurality of injectors connected to the engine main body, each of which is arranged to inject fuel into the combustion chamber of a corresponding cylinder. do.

According to the above configuration, an intake common part common to a plurality of cylinders and a plurality of intake branch parts branching from the common intake part are formed in the engine body, and the throttle body and the injector are connected to the engine body. Compared to the case where a so-called intake manifold is disposed between the intake manifold and the throttle body, for example, a flange portion for connecting the intake manifold can be omitted. In this way, the above configuration can contribute to making the internal combustion engine more compact.

Preferably, a fuel distribution pipe common to the plurality of injectors is arranged between the engine main body and the throttle body. With this configuration, the throttle body can be placed closer to the engine body, making it possible to further downsize the internal combustion engine.

Preferably, the fuel distribution pipe common to the plurality of injectors is arranged to be aligned with the throttle body in the cylinder axis direction. With this configuration, the throttle body can be placed even closer to the engine body, making it possible to further downsize the internal combustion engine.

Preferably, a sensor related to intake air flowing through the intake passage of the throttle body is attached to an outer surface of the engine body. With this configuration, the throttle body can be made more compact than when the sensor is disposed on the throttle body.

Preferably, the connectors of the plurality of injectors are oriented in different directions. By arranging the connectors of a plurality of injectors facing different directions, the injectors can be efficiently installed in the gaps between them and surrounding components.

Preferably, the engine body is a cylinder head. According to this configuration, an intake common portion common to a plurality of cylinders and a plurality of intake branch portions branching from the common intake portion can be formed in the cylinder head, so that the internal combustion engine can be made more compact. Note that the location where the sensor related to the intake air flowing through the intake passage of the throttle body is attached is not limited to the cylinder head of the engine body, but may be the head cover.

According to the above-mentioned aspect of the present invention, it is possible to contribute to the downsizing of an internal combustion engine having a plurality of cylinders, which is provided with the above-described novel configuration that has not been seen in the past.

1 is a perspective view of a part of an internal combustion engine according to an embodiment of the present invention, and is a perspective view of the vicinity of a throttle body connected to a cylinder head of an engine main body. 2 is a side view of a portion of the internal combustion engine of FIG. 1; FIG. 2 is a perspective view of a portion of the internal combustion engine of FIG. 1 from another angle; FIG. FIG. 2 is a step-by-step cross-sectional view from the throttle body to the cylinder of the internal combustion engine in FIG. 1, in which (a) is a cross section at the cylinder, (b) is a cross section at the intake branch, and (c) is a cross section at the branch start point. , (d) shows a cross section at the throttle body. FIG. 2 is a front view showing a throttle body and an injector arranged in a model of the intake passage portion of the cylinder head of the internal combustion engine shown in FIG. 1; FIG. 2 is a right side view showing a throttle body and an injector arranged in a model of the intake passage portion of the cylinder head of the internal combustion engine shown in FIG. 1; 6 is a cross-sectional view of a portion of the internal combustion engine of FIG. 1 at a position corresponding to the position along the line VII-VII of FIG. 5; FIG. 6 is a cross-sectional view of a portion of the internal combustion engine of FIG. 1 at a position corresponding to the position along line VIII-VIII of FIG. 5; FIG. 2 is a conceptual diagram regarding an intake structure of the internal combustion engine of FIG. 1. FIG.

Embodiments according to the present invention will be described below based on the accompanying drawings. Identical parts (or configurations) are given the same reference numerals, and their names and functions are also the same. Therefore, detailed description thereof will not be repeated.

An internal combustion engine E according to an embodiment of the present invention will be described based on FIGS. 1 to 9. FIG. 1 shows a perspective view of a portion of the intake side of an internal combustion engine E in which a throttle body 14 is directly connected to a cylinder head 20 of an engine body B, and FIG. 2 shows a side view thereof. Fig. 3 shows a part of the internal combustion engine E shown in Fig. 1, seen from a different position than Fig. 1, specifically, from the upper side of the cylinder head, and Fig. 4 shows a part of the internal combustion engine E shown in Fig. 1, which is almost the same as Fig. 3. 1 shows a step-by-step cross-sectional view of the internal combustion engine from the throttle body to the cylinder, viewed from the side. Note that Figure 4(a) is a cross section at the cylinder, Figure 4(b) is a cross section at the intake branch, Figure 4(c) is the cross section at the branch start, and Figure 4(d) is the cross section at the throttle body. A cross section is shown. FIG. 5 is a front view showing the throttle body 14 and the injector 28 arranged on a model M of the intake passage of the cylinder head of the internal combustion engine E, and FIG. 6 shows the throttle body 14 and the injector 28 arranged on the model M. 7 is a sectional view of a part of the internal combustion engine E at a position corresponding to the position along line VII-VII in FIG. 5, and FIG. 8 is a right side view showing the arrangement. FIG. 2 is a cross-sectional view of a portion of the internal combustion engine E at a position corresponding to the position along line VIII-VIII of FIG. FIG. 9 is a conceptual diagram of the intake structure IS of the internal combustion engine E, and the exhaust system is omitted. Note that in FIGS. 5 to 8, fuel F injected from the injector 28 is schematically shown.

The internal combustion engine (hereinafter referred to as engine) E is an engine having multiple cylinders, that is, a multi-cylinder engine, and more specifically, an engine having two cylinders. However, the present invention does not limit the number of cylinders of the engine. The engine 10 includes a cylinder block 18 defining cylinders 16, a cylinder head 20 connected to the cylinder block 18, and a head cover 22 connected to the cylinder head 20. A mixture of intake air taken in through an intake passage 26 and fuel injected from an injector 28 is combusted in a combustion chamber 24 defined by a cylinder block 18, a cylinder head 20, and a piston. The piston reciprocates within the cylinder block 16 along the cylinder axis C, which rotates the crankshaft rotatably supported by the crankcase on the opposite side of the cylinder head 20 of the cylinder block 18, and the engine E is powered. Output. Note that in this specification, the engine body B refers to a part of the engine E that includes the cylinder block 18, the cylinder head 20, the head cover 22, and the crankcase. An intake device including a throttle body 14 is connected to the cylinder head 20 of the engine body B, and an exhaust device including an exhaust purification device and a muffler is connected thereto.

In the engine E, an air cleaner (not shown) and a throttle body 14 are provided in the intake passage 26 in this order from the upstream side in the intake flow direction. The air cleaner and the throttle body 14 each define a part of the intake passage 26. Note that the air cleaner communicates with the intake port on the upstream side thereof.

The throttle body 14 defines an intake passage 14 a having a substantially circular cross section and forming a part of the intake passage 26 . The throttle body 14 is rotatably supported within the throttle body 14 by a throttle valve shaft 14b that is perpendicular to the flow direction of intake air in the intake passage 14a, that is, perpendicular to the center axis of the intake passage 14a. The intake passage 14a is provided with a throttle valve 14c that can variably control the flow passage area of the intake passage 14a and open and close the intake passage 14a. The throttle valve 14c is of a butterfly type and includes a throttle valve shaft 14b and a disk-shaped valve body 14d that is fixed to the throttle valve shaft 14b and rotates integrally with the throttle valve shaft 14b.

In the engine E, the intake passage 26 branches downstream of the throttle body 14 so as to distribute intake air to each cylinder. In particular, here, an intake common part 30 common to a plurality of cylinders 16, a branch start part 32 that directly communicates with the downstream side of the intake common part 30, and a plurality of intake branch parts 34 that branch from the branch start part 32 to the downstream side. is formed in the engine body B, particularly in the cylinder head 20 thereof. The throttle body 14 is directly connected to the cylinder head 20 so that the intake passage 14a of the throttle body 14 directly communicates with the intake common portion 30 of the cylinder head 20. The engine E is a four-valve engine with two intake valves and two exhaust valves for each cylinder 16, and since it has two cylinders, four intake branch portions 34 are defined in the cylinder head 20. Two adjacent intake branches 34 among the four intake branches 34 communicate with one cylinder 16, and the remaining two intake branches 34 communicate with the other cylinder 16.

Therefore, as shown in FIG. 4, the intake air that has passed through the air cleaner through the intake port passes through the intake passage 14a (FIG. 4(d)) of the throttle body 14 depending on the open state of the throttle valve 14c. It reaches the intake common part 30 (FIG. 4(c)) of the cylinder head 20, is divided at the downstream branch start part 32 (FIG. 4(c)), and is connected via each intake branch part 34 (FIG. 4(b)). can flow into the cylinder 16 where the

An injector 28 is provided to inject fuel into the intake air. In the engine E, an injector 28 is provided for each cylinder, so two injectors 28 are used. Each injector 28 is directly connected to the cylinder head 20 of the engine body B. The insertion portion 36 of the injector 28 is positioned above the connection portion 14e of the throttle body 14 to the cylinder head 20, when the direction from the crankshaft to the cylinder head 20 side is defined as upward in the direction of the cylinder axis C. (See Figures 1, 2, 7, and 8). Each injector 28 is provided in the cylinder head 20 so as to supply fuel injected from the downstream portion of the intake common portion 30, that is, around the branch start portion 32, to the combustion chamber 24 via the two corresponding intake branch portions 34. Therefore, fuel injected from one injector 28 is supplied to the combustion chamber 24 together with intake air via the two intake branches 34 connected to the corresponding cylinder 16.

A common fuel distribution pipe 38 is connected to these plurality of injectors 28 . Fuel from a fuel tank (not shown) is pumped by a fuel pump (not shown), reaches the fuel distribution pipe 38, and is supplied to the combustion chamber 24 via the injector 28. The fuel distribution pipe 38 is provided so as to extend parallel to the direction in which the cylinders 16 are arranged. The fuel distribution pipe 38 is arranged between the engine body B and the throttle body 14, as shown in FIGS. 1 to 3, 7, and 8. Here, the actuator 40 for rotationally driving the throttle valve shaft 14b is provided at one end of the throttle body 14 in the direction in which the cylinders 16 are arranged, and the throttle valve shaft 14b is provided so as to extend parallel to the direction in which the cylinders 16 are arranged. ing. Therefore, the fuel distribution pipe 38 extends substantially parallel to the throttle valve shaft 14b. In FIGS. 2, 7, and 8, the cylinders 16 are lined up in a direction perpendicular to the plane of the paper, and the throttle valve shaft 14 extends. 2, 7, and 8, a substantially V-shaped space is formed between the head cover 22 side of the cylinder head 20 of the engine body B and the throttle body 14. In FIGS. The fuel distribution pipe 38 is arranged in this approximately V-shaped space. That is, as shown in FIGS. 2, 7, and 8, when the engine body B is viewed in the direction in which the cylinders 16 are lined up or in the direction in which the throttle valve shaft 14 extends, the fuel distribution pipe 38 is connected to the cylinder head 20 of the engine body B. It is more obvious that the throttle body 14 is disposed between the throttle body 14 and the throttle body 14.

As shown in FIGS. 2, 7, and 8, the fuel distribution pipe 38 common to the plurality of injectors 28 is arranged to line up with the throttle body 14 in the direction of the cylinder axis C. That is, as described above, when defining the direction from the crankshaft to the cylinder head 20 side as upward in the direction of the cylinder axis C, the fuel distribution pipe 38 is arranged above the throttle body 14, and in this embodiment, the fuel distribution pipe 38 is arranged above the throttle body 14. It is provided directly above and close to the body 14.

Further, the injector 28 is provided with a coupler 42 which is a connector to which an output terminal of a harness connected to a control device (for example, an ECU) not shown is connected. The couplers 42 in the two injectors 28 are oriented in different directions. This is as shown in FIGS. 3 and 5, and is also clear from the fact that in the schematic diagram of FIG. 9, the center lines L1 and L2 of the two couplers 42 are non-parallel.

By the way, in recent years, various sensors have been arranged in the throttle body 14, specifically, an intake negative pressure sensor (Pb sensor), an intake air temperature sensor (Ta sensor), and a throttle position sensor (TPS sensor). It has become to. The intake negative pressure sensor detects the pressure of the intake air, the intake air temperature sensor detects the temperature of the intake air, and the throttle position sensor detects the opening degree of the throttle valve 14d, that is, the intake air taken into the combustion chamber 24. It detects the amount. That is, the intake negative pressure sensor, intake air temperature sensor, and throttle position sensor are all sensors related to intake air flowing through the intake passage 14a of the throttle body 14. Here, one of the sensors, specifically the suction negative pressure sensor 44, is attached to the outer surface B1 of the engine body B, particularly here to the outer surface 22o of the head cover 22. Note that the remaining sensors are housed in an electrical component housing portion 14f that is integrated with the throttle body 14, and are disposed in the throttle body 14, as in the past. Note that the sensor attached to a location away from the throttle body 14, that is, the outer surface 22o of the head cover 22, is the suction negative pressure sensor 44 here, but is not limited to the suction negative pressure sensor 44, and may be, for example, a suction negative pressure sensor (Pb sensor). ) and an intake air temperature sensor (Ta sensor). Note that the location where at least one of these sensors is attached is not limited to the outer surface 22o of the head cover 22, but may be the outer surface 20o of the cylinder head 20.

As described above, the engine E is characterized by the intake structure IS including the intake common part 30 and the intake branch part 34 formed in the cylinder head 20. The features, that is, the configuration, and the operations and effects thereof will be explained below.

Engine E has multiple cylinders 16. The cylinder head 20 of the engine body B of the engine E has an intake common part 30 common to the plurality of cylinders 16, and a plurality of intake branch parts 34 branched on the downstream side of the intake common part 30, each of which has a A plurality of intake branch portions 34 extending between the combustion chamber 24 of the corresponding cylinder 16 and the intake common portion 30 are defined. The throttle body 14 is connected to the cylinder head 20 of the engine main body B, and defines an intake passage 14a that communicates with the intake common portion 30. The plurality of injectors 28 are each connected to the engine body B, and each is arranged to inject fuel into the combustion chamber 24 of the corresponding cylinder 16. Therefore, the cylinder head 20 of the engine body B is formed with an intake common part 30 common to a plurality of cylinders 16 and a plurality of intake branch parts 34 branching from the common intake part 30, and the throttle body 14 and the injector 28 are formed in the engine body B. By connecting, compared to the case where a so-called intake manifold is disposed between the engine body B and the throttle body 14, for example, a flange portion for connecting the intake manifold can be omitted. In this way, the engine E including this intake structure IS can contribute to making the engine E more compact.

Further, a fuel distribution pipe 38 common to the plurality of injectors 28 is arranged between the engine body B and the cylinder head 20 of the throttle body 14. More specifically, in the internal combustion engine E, as shown in FIGS. 2, 7, and 8, when the engine body B is viewed in the direction in which the cylinders 16 are lined up or in the direction in which the throttle valve shaft 14 extends, 38 is arranged between the cylinder head 20 of the engine body B and the throttle body 14. With this configuration, the throttle body 14 can be placed closer to the engine body B, so that the engine E can be made even more compact.

Further, a fuel distribution pipe 38 common to the plurality of injectors 28 is arranged to line up with the throttle body 14 in the direction of the cylinder axis C. With this configuration, the throttle body 14 can be placed even closer to the engine body B. Therefore, according to this configuration, it is possible to further downsize the internal combustion engine.

The couplers 42, which are the connectors of the plurality of injectors 28, face in different directions. Therefore, by arranging the couplers 42 of the plurality of injectors 28 so as to face in different directions, the injector 28 can be efficiently installed in the gap between the injector 28 and the surrounding parts.

Furthermore, a sensor related to intake air flowing through the intake passage 14a of the throttle body 14, here an intake negative pressure sensor 44, is attached to the outer surface 22o of the head cover 22 of the outer surface B1 of the engine body B. With this configuration, the throttle body 14 can be made more compact than when the sensor 44 is disposed on the throttle body. Note that the location where the sensor 44 and the like are attached is not limited to the outer surface 22o of the head cover 22, but may be the outer surface 20o of the cylinder head 20, and the same effect can be achieved thereby.

Although the embodiments and modifications thereof according to the present invention have been described above, the present invention is not limited thereto. Various substitutions and changes are possible without departing from the spirit and scope of the invention as defined by the claims of this application. The present invention is applicable to various internal combustion engines, and is applicable to internal combustion engines installed in various vehicles, such as straddle-type vehicles such as motorcycles, multi-utility vehicles (MUV), etc. It is applicable to vehicles capable of traveling on rough terrain or internal combustion engines mounted on four-wheeled vehicles.

E Internal combustion engine B Engine body 14 Throttle body 14a Intake passage 14c Throttle valve 16 Cylinder 20 Cylinder head 24 Combustion chamber 30 Intake common part 34 Intake branch part 42 Coupler (connector)

Claims (6)

An internal combustion engine (E) having a plurality of cylinders,
An intake common part (30) common to the plurality of cylinders (16), and a plurality of intake branch parts (34) branched downstream of the intake common part (30), each of which has a corresponding cylinder (16). an engine main body (B) defining a plurality of intake branch portions (34) extending between the combustion chamber (24) and the intake common portion (30);
a throttle body (14) that is connected to the engine body (B) and defines an intake passage (14a) that communicates with the intake common portion (30);
A plurality of injectors (28) connected to the engine body (B), each of which is arranged to inject fuel into the combustion chamber (24) of a corresponding cylinder (16). ) An internal combustion engine (E) characterized by comprising: The fuel distribution pipe (38) common to the plurality of injectors (28) is arranged between the engine body (B) and the throttle body (14). Internal combustion engine (E). 3. The fuel distribution pipe (38) common to the plurality of injectors (28) is arranged in line with the throttle body (14) in the direction of the cylinder axis (C). Internal combustion engine (E) as described. Any one of claims 1 to 3, wherein a sensor (44) related to intake air flowing through the intake passage (14a) of the throttle body (14) is attached to an outer surface (B1) of the engine body (B). The internal combustion engine (E) according to item 1. Internal combustion engine (E) according to any one of claims 1 to 4, characterized in that the connectors (42) of the plurality of injectors (28) face in mutually different directions. The internal combustion engine (E) according to any one of claims 1 to 5, wherein the engine body (B) is a cylinder head (20).

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