JP2013221459A - Peripheral structure for internal combustion engine - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide a peripheral structure for an internal combustion engine, which can reduce a radiation amount from an exhaust manifold and can improve degree of freedom of a mounting layout of onboard auxiliary equipment mounted in the rear of a vehicle of the internal combustion engine.SOLUTION: A peripheral structure for an internal combustion engine includes: an exhaust manifold cooling circuit 51 which cools an exhaust manifold 3 provided in the rear of a vehicle of an engine 1 by circulation of coolant; and a bypass cooling circuit 52 which communicates to the exhaust manifold cooling circuit 51 and is arranged in peripheral space K at onboard auxiliary equipment side between the exhaust manifold 3 and an alternator 4 mounted in the rear of the vehicle of the engine 1. The peripheral structure controls a flow rate of the coolant circulating through the bypass cooling circuit 52 in accordance with a temperature of the alternator 4, by a flow control valve 53.

Description

  The present invention relates to a peripheral structure of an internal combustion engine including an exhaust manifold provided on the rear side of the internal combustion engine and an in-vehicle auxiliary device mounted on the rear side of the internal combustion engine.

  2. Description of the Related Art Conventionally, a peripheral structure of an internal combustion engine having an exhaust manifold that has one end connected to the rear surface of the engine facing the rear of the vehicle and extending toward the rear of the vehicle and an alternator disposed on the rear side of the engine is known. (For example, refer to Patent Document 1).

Japanese Patent No. 4010259

By the way, in the conventional peripheral structure of the internal combustion engine, the exhaust manifold extends from the back of the engine where the traveling wind is difficult to hit to the rear of the vehicle, so the cooling effect due to the traveling wind cannot be expected, and the exhaust manifold becomes hot. It was easy to be. For this reason, when the alternator is disposed close to the exhaust manifold, the alternator may be affected by the heat released from the exhaust manifold.
That is, the distance between the exhaust manifold and the alternator has to be ensured so that the alternator is not affected by the heat from the exhaust manifold. For this reason, the mounting position of on-vehicle auxiliary equipment such as an alternator including electrical components is limited by the amount of heat released from the exhaust manifold, resulting in a problem that the degree of freedom in layout is reduced.

  The present invention has been made paying attention to the above problems, and can reduce the amount of heat released from the exhaust manifold and improve the mounting layout flexibility of the in-vehicle auxiliary equipment mounted on the vehicle rear side of the internal combustion engine. An object is to provide a peripheral structure of an internal combustion engine.

In order to achieve the above object, in the peripheral structure of the internal combustion engine of the present invention, an exhaust manifold, an in-vehicle auxiliary machine, an exhaust manifold cooling circuit, a bypass cooling circuit, an auxiliary machine temperature detecting means, and a flow rate control mechanism are provided. Prepared.
The exhaust manifold extends from the internal combustion engine toward the rear of the vehicle.
The in-vehicle auxiliary machine is mounted on the vehicle rear side of the internal combustion engine.
The exhaust manifold cooling circuit cools the exhaust manifold by circulating cooling water.
The bypass cooling circuit communicates with the exhaust manifold cooling circuit and is disposed in a space around the on-vehicle accessory side of the exhaust manifold.
The auxiliary machine temperature detecting means detects the temperature of the in-vehicle auxiliary machine.
The flow rate control mechanism controls the flow rate of the cooling water flowing through the bypass cooling circuit in accordance with the temperature of the in-vehicle auxiliary machine detected by the auxiliary machine temperature detecting means.

In the peripheral structure of the internal combustion engine of the present invention, the flow rate of the cooling water flowing through the bypass cooling circuit is controlled by the flow rate control mechanism in accordance with the temperature of the on-vehicle auxiliary machine.
Therefore, the flow rate of the cooling water flowing through the bypass cooling circuit is controlled so as to match the temperature of the in-vehicle auxiliary equipment, and the peripheral space on the in-vehicle auxiliary equipment side of the exhaust manifold can be appropriately cooled, and from this exhaust manifold to the periphery The amount of heat released can be suppressed.
As a result, the temperature increase of the in-vehicle auxiliary equipment can be suppressed, so that the in-vehicle auxiliary equipment can be laid out without being limited by the heat radiation from the exhaust manifold, and the in-vehicle auxiliary equipment mounted on the vehicle rear side of the internal combustion engine. The degree of freedom for mounting the machine can be improved.

1 is an overall perspective view showing a peripheral structure of an internal combustion engine according to a first embodiment. It is explanatory drawing which shows the cooling circuit of Example 1 typically. FIG. 3 is a plan view illustrating a cooling circuit according to the first embodiment. It is a side view which shows the exhaust manifold cooling circuit of Example 1. FIG. FIG. 3 is an explanatory diagram illustrating a flow of cooling water in the peripheral structure of the internal combustion engine according to the first embodiment. FIG. 6 is a perspective view showing an external appearance of an exhaust manifold according to a second embodiment. (a) is a top view when it sees from the arrow A direction shown in FIG. 6, (b) is BB sectional drawing shown in FIG. FIG. 6 is an explanatory diagram showing a flow of cooling water in a peripheral structure of an internal combustion engine according to a second embodiment. FIG. 6 is an explanatory diagram schematically showing a cooling circuit in a peripheral structure of an internal combustion engine according to a third embodiment.

  EMBODIMENT OF THE INVENTION Hereinafter, the form for implementing the surrounding structure of the internal combustion engine of this invention is demonstrated based on Example 1- Example 3 shown on drawing.

First, the configuration will be described.
The configuration of the peripheral structure of the internal combustion engine of the first embodiment will be described by dividing it into “the overall configuration around the internal combustion engine” and “the configuration of the cooling circuit”.

[Overall configuration around the internal combustion engine]
FIG. 1 is an overall perspective view showing a peripheral structure of the internal combustion engine of the first embodiment. Note that the direction indicated by the arrow X in FIG. 1 indicates the front of the vehicle.

  The peripheral structure of the internal combustion engine of the first embodiment includes an engine (internal combustion engine) 1, an automatic transmission 2, an exhaust manifold 3, an alternator (on-vehicle auxiliary machine) 4, and a cooling circuit 5.

The engine 1 is a gasoline engine or a diesel engine, and is disposed in an engine room formed in the front portion of the vehicle. An automatic transmission 2 is connected to the engine output shaft via a flywheel (not shown). And this engine 1 has the back surface 1a which faced the vehicle rear, the some exhaust port 11 ... formed in this back surface 1a, and the cooling water channel | path 12 formed in the inside.
The cooling water passage 12 is configured such that cooling water circulates in the engine 1, but further includes a cooling water outlet 12a formed on the back surface 1a and a cooling water inlet 12b formed on the back surface 1a (FIG. 2). Reference).

  The automatic transmission 2 is, for example, a stepped transmission that automatically switches stepped gears such as forward 7 speed / reverse 1 speed according to vehicle speed, accelerator opening, and the like. The output shaft of the automatic transmission 2 is connected to left and right drive wheels via a propeller shaft, a differential, and left and right drive shafts (not shown).

The exhaust manifold 3 is a part for collectively delivering exhaust gas discharged from the plurality of exhaust ports 11 of the engine 1 to the exhaust pipe 35. The exhaust manifold 3 is connected to the rear surface 1a of the engine 1 and is disposed at the rear of the vehicle. Has been extended towards. The exhaust manifold 3 includes a plurality of exhaust ducts 31,... Connected to the plurality of exhaust ports 11,..., A support plate 32 that integrally supports the plurality of exhaust ducts 31,. .., And a catalyst 34 provided between the collective duct 33 and the exhaust pipe 35.
Each of the plurality of exhaust ducts 31 is formed of an iron pipe and has a fixing flange 31a for fixing to the back surface 1a of the engine 1 at one end. The support plate 32 is fixed to, for example, a cross member (not shown).

The alternator 4 is one of in-vehicle auxiliary devices mounted on the back surface 1a side of the engine 1, that is, on the vehicle rear side of the engine 1, and converts mechanical kinetic energy transmitted from the engine 1 into alternating electrical energy. And it is an apparatus which charges a vehicle-mounted battery (not shown). Although not shown, the alternator 4 includes a power generation unit that generates three-phase AC power and a rectification unit that converts the generated three-phase AC power into DC power.
The alternator 4 is provided with a temperature sensor 41 for detecting the internal temperature of the alternator 4. The value detected by the temperature sensor 41 is input to a flow rate control valve 53 described later.

  The cooling circuit 5 is a circuit that communicates with a cooling water passage 12 formed in the engine 1 and cools the exhaust manifold 3 and its surroundings when cooling water for cooling the engine 1 flows.

[Configuration of cooling circuit]
FIG. 2 is an explanatory diagram schematically illustrating a cooling circuit according to the first embodiment. FIG. 3 is a plan view illustrating the cooling circuit according to the first embodiment. FIG. 4 is a side view showing the exhaust manifold cooling circuit of the first embodiment.

  As shown in FIG. 2, the cooling circuit 5 includes an exhaust manifold cooling circuit 51 that cools the exhaust manifold 3, a bypass cooling circuit 52 that cools a space K between the exhaust manifold 3 and the alternator 4, and a cooling circuit 5. And a flow rate control valve (flow rate control mechanism) 53 for controlling the flow rate of the flowing cooling water.

  The exhaust manifold cooling circuit 51 includes a plurality of upper surface ducts 51a,..., A plurality of lower surface ducts 51b,... (See FIG. 4), a first communication duct 51c, a second communication duct 51d, and a cooling water inflow duct 51e. And a cooling water outflow duct 51f.

  The plurality of upper surface ducts 51a,... Are iron pipes welded and fixed to the surfaces of the plurality of exhaust ducts 31,... Facing the vehicle, and extend in the same direction as the extending direction of each exhaust duct 31. ing.

  The plurality of lower surface ducts 51b,... Are iron pipes welded and fixed to the surfaces of the plurality of exhaust ducts 31,... Facing the vehicle lower side, and extend in the same direction as the extending direction of each exhaust duct 31. ing.

  The first communication duct 51c communicates one end of the upper surface duct 51a on the engine 1 side and one end of the lower surface duct 51b on the engine 1 side, and integrally communicates the adjacent upper and lower surface ducts 51a and 51b. The first communication duct 51c is welded and fixed to the surfaces of the plurality of exhaust ducts 31,.

  The second communication duct 51d communicates one end of the upper surface duct 51a on the support plate 32 side and one end of the lower surface duct 51b on the support plate 32 side, and integrally communicates the adjacent upper and lower surface ducts 51a and 51b. . The second communication duct 51d is welded and fixed to the surfaces of the plurality of exhaust ducts 31,.

  The cooling water inflow duct 51e is an iron pipe that connects the first communication duct 51c and the cooling water outlet 12a.

  The cooling water outflow duct 51f is an iron pipe that connects the first communication duct 51c and the cooling water inlet 12b.

The bypass cooling circuit 52 is made of an iron pipe communicating with the exhaust manifold cooling circuit 51, and has one end connected to the first communication duct 51c and the other end connected to the second communication duct 51d. That is, the bypass cooling circuit 52 is formed by branching the first communication duct 51c and the second communication duct 51d.
The bypass cooling circuit 52 extends in the same direction as the extending direction of the exhaust duct 31, but is disposed with a gap S between the bypass duct 52 and the exhaust duct 31 closest to the alternator 4. (See FIGS. 2 and 3). In other words, the bypass cooling circuit 52 is disposed in the space K between the exhaust manifold 3 and the alternator 4, which is a space around the alternator side of the exhaust manifold 3.

The flow rate control valve (flow rate control mechanism) 53 is a solenoid valve provided in the middle of the cooling water inflow duct 51e, and this cooling control valve 53 (flow rate control mechanism) 53 The water inflow duct 51e is controlled to open and close.
That is, the flow rate control valve 53 opens the cooling water inflow duct 51e when the detected value of the temperature sensor 41 becomes a predetermined value or more, and allows the cooling water to flow through the exhaust manifold cooling circuit 51 and the bypass cooling circuit 52. When the detected value of the temperature sensor 41 is less than the predetermined value, the cooling water inflow duct 51e is closed, and the cooling water circulation to the exhaust manifold cooling circuit 51 and the bypass cooling circuit 52 is stopped. Thereby, the flow rate of the cooling water flowing through the bypass cooling circuit 52 is controlled by the temperature of the alternator 4 detected by the temperature sensor 41.
The “predetermined value” described above is a limit temperature that does not adversely affect the function (power generation function) of the alternator 4.

  Next, the operation of the peripheral structure of the internal combustion engine of the first embodiment will be described by dividing it into “exhaust manifold cooling operation” and “on-vehicle accessory cooling operation”.

[Exhaust manifold cooling action]
FIG. 5 is an explanatory diagram illustrating the flow of cooling water in the peripheral structure of the internal combustion engine according to the first embodiment.

  In the first embodiment, when the exhaust gas is discharged from the plurality of exhaust ports 11,... As the engine 1 is driven, the exhaust gas passes through the exhaust ducts 31,. It flows and is discharged to the atmosphere.

  At this time, since the engine 1 becomes high temperature, the exhaust gas also becomes high temperature, and the exhaust manifold 3 through which the high-temperature exhaust gas flows becomes high temperature. Further, the internal temperature of the alternator 4 disposed behind the vehicle of the engine 1 also rises due to the heat effect from the engine 1 and the heat generated by driving the internal power generation unit. At this time, since the exhaust manifold 3 and the alternator 4 are disposed on the back surface 1a side of the engine 1, a cooling effect by the traveling wind cannot be expected.

  Therefore, when the detected value from the temperature sensor 41 provided in the alternator 4 becomes equal to or greater than a predetermined value, the flow rate control valve 53 that has closed the cooling water inflow duct 51e is driven to open the cooling water inflow duct 51e. . Thereby, the cooling water outlet 12a and the cooling water inflow duct 51e communicate with each other, and the cooling water circulating through the cooling water passage 12 in the engine 1 flows into the cooling circuit 5. Then, the cooling water flowing into the cooling circuit 5 flows out from the cooling water outflow duct 51f to the cooling water inlet 12b and is circulated to the cooling water passage 12.

Here, the cooling water that has flowed into the exhaust manifold cooling circuit 51 of the cooling circuit 5 flows from the first communication duct 51c to the upper surface ducts 51a and the lower surface ducts 51b, and passes through the second communication duct 51d to flow out the cooling water. It flows into the duct 51f.
The first communication duct 51c, each upper surface duct 51a, each lower surface duct 51b, and the second communication duct 51d are welded and fixed to the surface of the exhaust duct 31, respectively. For this reason, heat exchange is performed between the cooling water flowing through the ducts 51a, 51b, 51c, and 51d and the exhaust duct 31, and the heat of the exhaust duct 31 is absorbed by the cooling water, thereby cooling the exhaust duct 31. .
As a result, the amount of heat generated from the exhaust manifold 3 is suppressed, and the temperature around the exhaust manifold 3 is suppressed from becoming high.

[Vehicle auxiliary machine cooling action]
As described above, when the flow rate control valve 53 is driven when the detection value from the temperature sensor 41 provided in the alternator 4 becomes a predetermined value or more and the cooling water flows into the cooling circuit 5, the cooling water It flows from the inflow duct 51e to the first communication duct 51c and further flows into the bypass cooling circuit 52 branched from the first communication duct 51c.

  The cooling water that has flowed into the bypass cooling circuit 52 exchanges heat with the air in the space K between the exhaust manifold 3 in which the bypass cooling circuit 52 is disposed and the alternator 4. Thereby, the heat in the space K is absorbed by the cooling water, and the space K is cooled.

As a result, the peripheral space on the alternator 4 side of the exhaust manifold 3 is appropriately cooled, and the amount of heat that affects the alternator 4 can be suppressed. Thereby, the temperature rise of the alternator 4 can be positively suppressed, and the alternator 4 can be laid out without being limited by the amount of heat released from the exhaust manifold 3.
That is, for example, the layout of the alternator 4 mounted on the vehicle rear side of the engine 1 can be improved, for example, by laying out the alternator 4 close to the exhaust manifold 3.

  Furthermore, by improving the mounting layout flexibility of the alternator 4 on the vehicle rear side of the engine 1, the collision space in the engine room can be expanded, and the weight of the shock absorbing member at the time of the collision provided in the vehicle body can be reduced.

  Then, by adjusting the opening degree of the flow control valve 53, the flow rate of the cooling water flowing into the cooling circuit 5 is adjusted, whereby the exhaust manifold 3 and the space K between the exhaust manifold 3 and the alternator 4 (of the exhaust manifold 3). The cooling performance of the peripheral space on the alternator 4 side) can be adjusted.

That is, even if the detected value from the temperature sensor 41 exceeds a predetermined value, when the detected value is relatively low, the opening degree of the flow control valve 53 is made relatively small. Thereby, the flow rate of the cooling water flowing into the cooling circuit 5 is reduced, and the cooling performance of the exhaust manifold 3 and the space K can be kept low. Thereby, the cooling performance of the engine 1 is not suppressed unnecessarily, and the cooling performance of the engine 1 can be ensured.
On the other hand, when the detected value from the temperature sensor 41 exceeds a predetermined value and the detected value is relatively high, the opening degree of the flow control valve 53 is made relatively large. As a result, the flow rate of the cooling water flowing into the cooling circuit 5 increases, the cooling performance of the exhaust manifold 3 and the space K can be increased, and the heat influence on the alternator 4 can be prevented.

Next, the effect will be described.
In the peripheral structure of the internal combustion engine of the first embodiment, the following effects can be obtained.

(1) an exhaust manifold 3 extending from the internal combustion engine 1 toward the rear of the vehicle;
An in-vehicle auxiliary machine (alternator) 4 mounted on the vehicle rear side of the internal combustion engine 1;
An exhaust manifold cooling circuit 51 for cooling the exhaust manifold 3 by circulating cooling water;
A bypass cooling circuit 52 that communicates with the exhaust manifold cooling circuit 51 and is disposed in a space (space K) on the in-vehicle accessory side of the exhaust manifold 3;
Auxiliary equipment temperature detecting means (temperature sensor) 41 for detecting the temperature of the in-vehicle auxiliary equipment 4;
A flow rate control mechanism (flow rate control valve) 53 for controlling the flow rate of the cooling water flowing through the bypass cooling circuit 52 according to the temperature of the in-vehicle auxiliary device 4 detected by the auxiliary device temperature detecting means 41;
It was set as the structure provided with.
As a result, the amount of heat released from the exhaust manifold can be reduced, and the degree of freedom for mounting the on-vehicle auxiliary equipment mounted on the vehicle rear side of the internal combustion engine can be improved.

Example 2 is an example in which the exhaust manifold is formed of cast iron.
FIG. 6 is a perspective view showing an external appearance of the exhaust manifold of the second embodiment. 7A is a plan view when viewed from the direction of arrow A shown in FIG. 6, and FIG. 7B is a cross-sectional view taken along line BB shown in FIG.

  The exhaust manifold 3 </ b> A according to the second embodiment illustrated in FIG. 6 includes an exhaust manifold head 6, a support plate 32, and a collective duct 33. Here, since the support plate 32 and the collective duct 33 are the same as those in the first embodiment, detailed description thereof is omitted.

  The exhaust manifold head (hereinafter referred to as “exhaust manifold head”) 6 includes a head body 61, a fixing flange 62, a plurality of exhaust passages 63,..., And an exhaust manifold cooling water passage 64. It is integrally formed with cast iron. On the side of the exhaust manifold 3A, an alternator 4 that is an in-vehicle auxiliary machine is mounted.

  The head main body 61 is a cast iron block to which a cooling water inflow duct 51e and a cooling water outflow duct 51f are connected, and is disposed behind the engine 1 in the vehicle. The cooling water inflow duct 51 e is connected to the cooling water outlet 12 a and communicates the cooling water passage 12 and one end of the exhaust manifold cooling water passage 64. A flow control valve 53 is provided in the middle of the cooling water inflow duct 51e. The cooling water outlet duct 51f is connected to the cooling water inlet 12b, and communicates the cooling water passage 12 and the other end of the exhaust manifold cooling water passage 64.

  The fixing flange 62 is a plate-like portion for fixing the head main body 61 to the back surface 1 a of the engine 1, and is integrally formed on the peripheral edge of the head main body 61 on the engine 1 side.

  The plurality of exhaust passages 63,... Are spaces where one end communicates with the plurality of exhaust ports 11, formed in the engine 1 and the other end connects to the collecting duct 33, and exhaust flows. The head body 61 is penetrated. The plurality of exhaust passages 63 are provided independently for each of the plurality of exhaust ports 11.

  The exhaust manifold cooling water passage 64 is a space in which a part of the exhaust water passage 64 communicates with the cooling water inflow duct 51 e and a part of the exhaust manifold cooling water passage 64 communicates with the cooling water outflow duct 51 f and flows through the head body 61. . Further, an intermediate portion of the exhaust manifold cooling water passage 64 includes a plurality of cooling portions 64a extending along the plurality of exhaust passages 63, and a communication portion 64b communicating the plurality of cooling portions 64a,. have. A part of the cooling section 64a (indicated by 64a 'in FIG. 7) is disposed on the outer peripheral portion of the exhaust passage 63 closest to the alternator 4, and includes an exhaust passage 63 through which exhaust flows and an alternator that is an in-vehicle accessory. 4 is arranged in a space K1 between the four. That is, a part of the exhaust manifold cooling water passage 64 constitutes an exhaust manifold cooling circuit for cooling the exhaust manifold 3A, and another part of the exhaust manifold cooling water passage 64 provides an on-vehicle auxiliary machine for the exhaust manifold 3A. A bypass cooling circuit arranged in the side peripheral space is configured.

Next, the operation of the peripheral structure of the internal combustion engine of the second embodiment will be described.
FIG. 8 is an explanatory diagram showing the flow of cooling water in the peripheral structure of the internal combustion engine of the second embodiment.

  In the second embodiment, when the exhaust gas is discharged from the plurality of exhaust ports 11,... As the engine 1 is driven, the exhaust gas passes through the exhaust passages 63,. (Not shown) and discharged to the atmosphere.

  At this time, since the engine 1 becomes high temperature, the exhaust gas becomes high temperature, and the exhaust head 6 of the exhaust manifold 3A through which the high temperature exhaust gas flows becomes high temperature. Further, the internal temperature of the alternator 4 disposed behind the vehicle of the engine 1 also rises due to the heat effect from the engine 1 and the heat generated by driving the internal power generation unit.

  When the detected value from the temperature sensor 41 provided in the alternator 4 becomes equal to or greater than a predetermined value, the flow rate control valve 53 that has closed the cooling water inflow duct 51e is driven to open the cooling water inflow duct 51e. . As a result, the cooling water outlet 12 a and the exhaust manifold cooling water passage 64 communicate with each other, and the cooling water circulating through the cooling water passage 12 in the engine 1 flows into the exhaust manifold cooling water passage 64. Then, the cooling water flowing into the exhaust manifold cooling water passage 64 flows out from the cooling water outflow duct 51 f to the cooling water inlet 12 b and is circulated to the cooling water passage 12.

Here, the cooling water that has flown into the exhaust manifold cooling water passage 64 sequentially flows through the cooling portions 64a,... And the communication portion 64b. That is, the cooling water flowing into the exhaust manifold cooling water passage 64 flows so as to sew between the exhaust passages 63. As a result, heat exchange is performed between the exhaust gas in the exhaust passage 63 and the cooling water, the heat of the exhaust gas is absorbed by the cooling water, and the head body 61 is cooled.
As a result, the amount of heat generated from the exhaust manifold 3A is suppressed, and the temperature around the exhaust manifold 3A is suppressed from becoming high.

Further, in this exhaust manifold cooling water passage 64, a part of the cooling portion 64 a (indicated by 64 a ′ in FIG. 8) is disposed on the outer peripheral portion of the exhaust passage 63 closest to the alternator 4. Therefore, the heat in the space K1 between the exhaust manifold 6 and the alternator 4 is absorbed by the cooling water, and the space K1 is cooled.
As a result, the peripheral space on the alternator 4 side of the exhaust manifold 3A is appropriately cooled, and the temperature rise of the alternator 4 is positively suppressed. Then, the alternator 4 can be laid out close to the exhaust manifold 3A, for example, without being limited by the amount of heat released from the exhaust manifold 3A. That is, even if it is cast iron exhaust manifold 3A, the mounting layout freedom degree of the alternator 4 mounted in the vehicle rear side of the engine 1 can be improved.

The third embodiment is an example in which cooling fins are provided in the cooling circuit.
FIG. 9 is an explanatory diagram schematically showing a cooling circuit in the peripheral structure of the internal combustion engine of the third embodiment.

  In the peripheral structure of the internal combustion engine of the third embodiment, as shown in FIG. 9, an exhaust manifold cooling circuit 51 for cooling the exhaust manifold 3, and a bypass cooling circuit 52 for cooling the space K between the exhaust manifold 3 and the alternator 4; , And a plurality of cooling fins 7.

The cooling fins 7 are formed to protrude from part of the surfaces of the exhaust manifold cooling circuit 51 and the bypass cooling circuit 52, and promote heat dissipation from the cooling water flowing inside the exhaust manifold cooling circuit 51 and the bypass cooling circuit 52.
Here, a large number of cooling fins 7 are provided in directions other than the alternator 4 so as not to dissipate heat toward the alternator 4 that is an in-vehicle auxiliary machine. That is, a large number of the cooling fins 7,... Are radiated from the exhaust manifold cooling circuit 51 and the bypass cooling circuit 52, for example, provided on the surface of the second communication duct 51d and the bypass cooling circuit 52 in the vicinity of the second communication duct 51d. It is provided on the surfaces of the exhaust manifold cooling circuit 51 and the bypass cooling circuit 52 not facing the alternator 4 so as not to direct the direction toward the alternator 4.

  Thereby, the cooling effect of the exhaust manifold 3 and the space K by the cooling water flowing through the exhaust manifold cooling circuit 51 and the bypass cooling circuit 52 is promoted, and the heat absorbed by the cooling water is controlled not to go to the alternator 4. The Therefore, the heat influence from the exhaust manifold 3 on the alternator 4 can be further suppressed, and the layout flexibility of the alternator 4 can be further improved.

Next, the effect will be described.
In the peripheral structure of the internal combustion engine of the first embodiment, the following effects can be obtained.

(2) At least one of the exhaust manifold cooling circuit 51 or the bypass cooling circuit 52 has a cooling fin 7 that promotes heat radiation from the cooling water and controls the heat radiation direction.
Thereby, the thermal influence from the exhaust manifold 3 to the alternator 4 which is an in-vehicle auxiliary machine can be further suppressed, and the layout flexibility of the alternator 4 can be further improved.

  As described above, the peripheral structure of the internal combustion engine of the present invention has been described based on the first to third embodiments, but the specific configuration is not limited to these embodiments, and the invention according to each claim is not limited thereto. Design changes and additions are allowed without departing from the gist.

  In the first to third embodiments, the alternator 4 that also generates heat is used as the in-vehicle auxiliary device mounted on the rear side of the engine 1. However, for example, a battery, various sensors, a starter motor, or the like may be used.

  In the first embodiment, the flow rate control valve 53 as a flow rate adjusting means is provided on the upstream side of the exhaust manifold cooling circuit 51 and the bypass cooling circuit 52, and the opening degree of the flow rate control valve 53 is adjusted to adjust the exhaust manifold cooling circuit. 51 and the bypass cooling circuit 52 are configured to simultaneously adjust the flow rates. However, the present invention is not limited to this. For example, the flow rate control valve 53 is provided between the first communication duct 51 c and the bypass cooling circuit 52, and the cooling water flowing through the bypass cooling circuit 52 by adjusting the opening degree of the flow control valve 53 The configuration may be such that only the flow rate is adjusted.

  Furthermore, in the first embodiment, the cooling water passage 12 through which the cooling water for cooling the engine 1 flows and the cooling circuit 5 through which the cooling water for cooling the exhaust manifold 3 and the space K flow communicate to share the cooling water. However, the cooling water that cools the engine 1 and the cooling water that cools the exhaust manifold 3 and the space K may flow in circuits that do not communicate with each other.

1 engine (internal combustion engine)
1a Back 11 Exhaust port 12 Cooling water passage 12a Cooling water outlet 12b Cooling water inlet 3 Exhaust manifold 31 Exhaust duct 32 Support plate 33 Collecting duct 34 Catalyst 35 Exhaust pipe 4 Alternator (on-vehicle auxiliary machine)
41 Temperature sensor (Auxiliary machine temperature detection means)
5 Cooling circuit 51 Exhaust manifold cooling circuit 51a Upper surface duct 51b Lower surface duct 51c First communication duct 51d Second communication duct 51e Cooling water inflow duct 51f Cooling water outflow duct 52 Bypass cooling circuit 53 Flow control valve (flow control mechanism)

Claims (2)

An exhaust manifold extending from the internal combustion engine toward the rear of the vehicle;
An in-vehicle accessory mounted on the vehicle rear side of the internal combustion engine;
An exhaust manifold cooling circuit for cooling the exhaust manifold by circulating cooling water;
A bypass cooling circuit that communicates with the exhaust manifold cooling circuit and is disposed in a space around the vehicle auxiliary equipment side of the exhaust manifold;
Auxiliary temperature detection means for detecting the temperature of the in-vehicle auxiliary machine,
A flow rate control mechanism for controlling the flow rate of the cooling water flowing through the bypass cooling circuit in accordance with the temperature of the in-vehicle auxiliary device detected by the auxiliary device temperature detecting means;
A peripheral structure of an internal combustion engine, comprising: The peripheral structure of the internal combustion engine according to claim 1,
At least one of the exhaust manifold cooling circuit or the bypass cooling circuit has cooling fins for promoting heat radiation from the cooling water and controlling the heat radiation direction.