WO2014054492A1

WO2014054492A1 - Cooling structure for engine

Info

Publication number: WO2014054492A1
Application number: PCT/JP2013/076003
Authority: WO
Inventors: 洋介勝谷
Original assignee: スズキ株式会社
Priority date: 2012-10-01
Filing date: 2013-09-26
Publication date: 2014-04-10
Also published as: CN104685181B; JP2014070623A; IN2015DN01739A; CN104685181A; JP6003491B2

Abstract

A cooling structure for an engine is provided to enable a component such as an injector to be appropriately cooled, the component being affected by the heat of the cylinder of the engine and the heat of the cylinder head thereof. The cooling structure for an engine comprises: an air guide member which covers portions of both the cylinder and the cylinder head of the engine and which forms a cooling channel for guiding cooling air to both the cylinder and the cylinder head; and an air delivery member for delivering air to the cooling channel. The cooling structure for an engine is characterized by being configured such that the air guide member has a body section for forming the cooling channel and also has a cover section for forming a branch channel at a position separated from both the cylinder and the cylinder head, the branch channel being branched from the cooling channel and guiding air to a component which is separate from both the cylinder and the cylinder head.

Description

Engine cooling structure

The present invention relates to an engine cooling structure, and more particularly to an engine cooling structure provided with an air guide member.

2. Description of the Related Art Conventionally, a motorcycle that employs an engine cooling structure including a shroud that covers a cylinder and a cylinder head and a fan for blowing air is known (for example, see Patent Document 1). In this type of motorcycle, air is guided by a fan for blowing air through a flow path formed by a shroud to cool a heated cylinder and cylinder head. Since the fan is rotated by the power of the engine and the cylinder and the cylinder head are forcibly cooled, higher cooling efficiency can be obtained compared to natural cooling by running wind.

In such a motorcycle, an injector for controlling the supply of fuel to the combustion chamber is disposed in the vicinity of the cylinder head of the engine. When the injector becomes hot due to heat from the cylinder and the cylinder head, the fuel in the injector is vaporized, causing problems such as unstable engine speed and reduced output. Therefore, in the cooling structure described in Patent Document 1, a flow path that guides the air that has passed through the cylinder and the cylinder head to the injector is formed so that the injector is cooled.

JP 2010-223211

However, in the engine cooling structure described in Patent Document 1, since the air whose temperature has passed through the cylinder and the cylinder head is guided to the injector, the cooling efficiency of the injector may be reduced. In this case, it is difficult to prevent the fuel in the injector from being vaporized.

The present invention has been made in view of such a point, and an object thereof is to provide an engine cooling structure capable of appropriately cooling components such as an injector and the like that are affected by heat of an engine cylinder and a cylinder head.

An engine cooling structure of the present invention provided to solve the above-described problems covers a part of an engine cylinder and a cylinder head, and forms a cooling flow path that guides cooling air to the cylinder and the cylinder head. A cooling structure for an engine comprising: an air guide member that performs air blowing; and a blower member that sends the air to the cooling flow path, wherein the air guide member includes a body portion that forms the cooling passage, the cylinder, and the cylinder A branching channel for guiding the air to a part different from the cylinder and the cylinder head at a position away from the cylinder head; and a shielding part formed by branching the cooling channel. To do.

According to this configuration, the air guide member has the shielding part that forms the branch flow path that guides the air to a component different from the main body part, and therefore, air different from the air that cools the cylinder and the cylinder head of the engine. Can cool parts. Further, since the branch flow path is formed at a position away from the cylinder and the cylinder head, the propagation of heat from the cylinder and the cylinder head to the branch flow path can be suppressed, and the cooling efficiency of the parts can be increased. Therefore, an engine cooling structure capable of appropriately cooling components affected by the heat of the cylinder and the cylinder head is realized.

In the engine cooling structure of the present invention having the above characteristics, it is preferable that the shielding portion branches the cooling flow path at a position before the air from the blowing member reaches the cylinder and the cylinder head. According to this structure, since the shielding part branches the cooling flow path at a position before the air from the air blowing member reaches the cylinder and the cylinder head, the air flowing through the branch flow path due to the heat of the cylinder and the cylinder head. Temperature rise can be prevented. Therefore, the cooling efficiency of components can be improved.

In the engine cooling structure of the present invention, the branch flow path may be formed along the inner wall surface of the air guide member so as to sandwich the cooling flow path between the cylinder and the cylinder head. preferable. According to this configuration, the branch flow path is formed along the inner wall surface of the air guide member so as to sandwich the cooling flow path between the cylinder and the cylinder head. Can further suppress the propagation of heat. Further, since the cooling channel is not blocked by the branch channel, the cooling efficiency of the cylinder and the cylinder head can be maintained high.

Also, in the engine cooling structure of the present invention, it is preferable that the shielding portion is separate from the main body portion of the air guide member and is formed of a member formed of a different material. According to this configuration, since the degree of freedom of the shape is increased as compared with the case where the air guide member and the shielding portion are integrally formed, the cooling flow path and the branch flow path are reliably separated from the cylinder and the cylinder head. The propagation of heat to the branch channel can be suppressed. Further, since the material of the air guide member and the material of the shielding part can be changed, the heat insulating effect of the shielding part can be enhanced, and the propagation of heat from the cylinder and the cylinder head to the branch channel can be further suppressed.

Further, in the engine cooling structure of the present invention, the another component may be a fuel injection device. According to this configuration, since the fuel injection device can be appropriately cooled by the air supplied through the branch flow path, the fuel can be stably supplied by preventing the fuel from evaporating in the fuel injection device.

As described above, according to the present invention, it is possible to provide an engine cooling structure capable of appropriately cooling components such as an injector affected by the heat of the cylinder and the cylinder head.

1 is a perspective view showing an appearance of a motorcycle to which an embodiment of the present invention can be applied. Fig. 2 is a left side view showing a structure around a rear wheel of the motorcycle shown in Fig. 1. Fig. 2 is a right side view showing a structure around a rear wheel of the motorcycle shown in Fig. 1. FIG. 2 is a perspective view showing a structure of the engine of the motorcycle shown in FIG. 1 and its surroundings. FIG. 5 is a cross-sectional view of the engine shown in FIG. 4 cut along a plane perpendicular to the vehicle width direction. It is a perspective view for demonstrating the cooling structure of the engine shown by FIG. It is a perspective view which shows the shape of the shroud in the cooling structure of the engine shown by FIG. It is a perspective view of the shielding part in an engine cooling structure. It is a schematic diagram which shows the flow of the air in a shroud shown by FIG.

Hereinafter, embodiments of the present invention will be described in detail with reference to the accompanying drawings. In the following, an example in which the engine cooling structure according to the present invention is applied to a scooter type motorcycle will be described, but the application target is not limited to this and can be changed. For example, the engine cooling structure according to the present invention may be applied to other types of motorcycles, four-wheeled vehicles, and the like.

In addition, in the following description, the expressions indicating up and down, left and right, front and rear, etc. are used in the illustrated state or in the state where the motorcycle is installed. For example, the front of the vehicle body is indicated by an arrow F in each figure used in the following description. In the following drawings, some components may be omitted for convenience of explanation.

As shown in FIG. 1 to FIG. 3, the scooter type motorcycle 1 is configured by attaching various covers as a vehicle body exterior to an underbone frame 11 made of steel or aluminum alloy. A leg shield 21 that protects the driver's legs is provided at the front of the motorcycle 1, and a step board 22 on which the legs are placed is disposed behind the leg shield 21. A side cover 23 that covers the side surface of the vehicle body is provided behind the step board 22.

The front fork 31 is rotatably supported at the front of the vehicle body via a steering shaft (not shown). A handlebar 32 for steering the front wheel 3 is provided above the front fork 31. A brake lever 33 is provided on the handle bar 32, and a headlamp 34 is disposed in front of the handle bar 32. A front fender 35 that covers the upper part of the front wheel 3 is installed at the lower part of the front fork 31 while the front wheel 3 is rotatably supported. The front wheel 3 is provided with a brake disk and a caliper (both not shown) that sandwich the brake disk.

The seat 5 is disposed above the side cover 23, and a tail lamp 47 and a rear fender 48 are provided at the rear of the side cover 23. Inside the side cover 23, a fuel tank (not shown) is disposed below the seat 5, and an engine 6 is provided further below the fuel tank. As shown in FIG. 4, an injector (fuel injection device) 7 that controls fuel supply is attached to the left front portion of the engine 6. Fuel is sent from the fuel tank to the injector 7 through the fuel hose 71.

On the right side of the engine 6, a shroud 101 is attached as a wind guide member that covers a part of the engine 6. An opening 1O1a is provided on the right side surface of the shroud 101, and a fan 102 as a blower member is disposed inside the shroud 101 corresponding to the opening 1O1a (see FIG. 3). The fan 102 is connected to a crankshaft (not shown) so as to be rotated by the power of the engine 6 and takes air into a space covered by the shroud 101. The engine 6 is forcibly cooled by the shroud 101 and the fan 102 even during idling.

The engine 6 and transmission (not shown) are integrated with a unit swing 8 that can swing up and down. A rear cushion unit 81 is attached between the unit swing 8 and the frame 11. The rear wheel 4 is rotatably supported at the rear part of the unit swing 8. A mission cover 41 is disposed on the left side of the rear wheel 4. The power of the engine 6 is transmitted to the rear wheel 4 via a pulley and a belt (both not shown) stored in the mission cover 41. In addition, a stand 42 that supports the vehicle body at the time of parking is provided in front of the mission cover 41 (lower left of the step board 22) (see FIG. 1).

An air cleaner box 43 is disposed above the mission cover 41. The air taken into the air cleaner box 43 is sent to the engine 6 through the intake hose 44, the throttle body 45, and the intake manifold 46. The combustion chamber of the engine 6 is supplied and mixed with air from the intake manifold 46 and fuel from the injector 7. The gas after combustion is discharged as exhaust gas from a muffler 61 provided on the right rear side of the engine 6.

Next, the engine 6 and its cooling structure according to this embodiment will be described. FIG. 5 is a cross-sectional view of the engine 6 cut along a plane perpendicular to the vehicle width direction. As shown in FIGS. 4 and 5, the engine 6 includes a substantially cylindrical cylinder 112 in front of the crankcase 111, and a cylinder head 113 and a cylinder head cover 114 are attached to the front of the cylinder 112. The cylinder 112 is provided with a plurality of heat radiation fins 112b.

A crankshaft (not shown) is accommodated in the crank chamber 111a in the crankcase 111 so that the rotation shaft is parallel to the vehicle width direction. A cylindrical space 112a in the cylinder 112 accommodates a piston (not shown) that can reciprocate in the cylinder axis direction (front-rear direction). The crankshaft and the piston are connected via a connecting rod (not shown) so that the reciprocating motion of the piston is converted into the rotational motion of the crankshaft.

The cylinder head 113 is formed with an intake port 113a for sending a mixture of air and fuel into the combustion chamber and an exhaust port 113b for discharging the gas after combustion outside the combustion chamber. An intake manifold 46 and an injector 7 are connected to the intake port 113a, and air and fuel are supplied. The cylinder head 113 is provided with an intake valve 113c for opening and closing the intake port 113a and an exhaust valve 113d for opening and closing the exhaust port 113b. An ignition plug (not shown) is provided adjacent to the intake port 113a and the exhaust port 113b, and the air-fuel mixture in the combustion chamber can be ignited by electric discharge.

The intake and exhaust of the engine 6 is performed by OHC (Overhead Camshaft) that opens and closes the intake valve 113c and the exhaust valve 113d by a camshaft (not shown). The camshaft includes a cam (not shown) having a shape corresponding to the opening / closing timing of the intake valve 113c or the exhaust valve 113d. One end of the camshaft is connected to the crankshaft via a power transmission mechanism (not shown) such as a sprocket or a cam chain. Thereby, the rotational force of the crankshaft is transmitted to the camshaft, and the intake valve 113c and the exhaust valve 113d are opened and closed so as to correspond to the rotation of the crankshaft.

In the engine 6 as described above, when the piston moves toward the bottom dead center, the intake valve 113c is opened, and air and fuel are sent into the combustion chamber through the intake manifold 46 and the injector 7 (intake stroke). Thereafter, the intake valve 113c is closed, and the air-fuel mixture is compressed by moving the piston toward the top dead center (compression stroke). When the piston reaches top dead center, the compressed air-fuel mixture ignited by the spark plug burns (combustion stroke). When the pressure in the combustion chamber increases due to the combustion of the air-fuel mixture, the piston moves toward the bottom dead center. Thereafter, when the piston reaches the bottom dead center and begins to move toward the top dead center again due to inertia, the exhaust valve 113d is opened and the burned gas is discharged from the exhaust port 113b (exhaust stroke). The valve operating apparatus including the intake valve 113c and the exhaust valve 113d provided in the cylinder head 113 enables such an operation.

The engine 6 converts the reciprocating motion of the piston into the rotational motion of the crankshaft by repeating the intake stroke, the compression stroke, the combustion stroke, and the exhaust stroke as described above. For this reason, the cylinder 112 and the cylinder head 113 are heated with the operation of the engine 6. In the engine 6 of the present embodiment, the cylinder 112 and the cylinder head 113 are cooled and kept at an appropriate temperature by the cooling structure including the shroud 101 and the fan 102.

Hereinafter, the cooling structure of the engine according to the present embodiment will be described with reference to FIGS.

6 and 7, the shroud 101 includes a right half 101R that covers the right side of the engine 6 and a left half 101L that covers the left front side of the engine 6.

The right half 101R extends to the left from the right wall WR covering the right front side of the engine 6, the upper right wall WRU extending leftward (inward in the vehicle width direction) from the front upper end of the right wall WR, and the front lower end of the right wall WR. A right lower wall WRD and a right front wall WRF extending leftward from the front end of the right wall WR are provided. The right wall WR is formed so as to cover the right side surface of the crankcase 111, the cylinder 112, and the cylinder head 113. The upper right wall WRU is formed to cover the upper right side of the cylinder 112 and the cylinder head 113, and the lower right wall WRD is formed to cover the lower right side of the cylinder 112 and the cylinder head 113.

The left half 101L includes a left wall WL covering the left front side of the engine 6, a left upper wall WLU extending rightward (inward in the vehicle width direction) from the upper end of the left wall WL, and a lower left wall extending rightward from the lower end of the left wall WL. WL. The left wall WL is formed so as to cover the left side surfaces of the cylinder 112 and the cylinder head 113. The upper left wall WLU is formed to cover the upper left side of the cylinder 112 and the cylinder head 113, and the lower left wall WLD is formed to cover the lower left side of the cylinder 112 and the cylinder head 113.

The right wall WR, the upper right wall WRU, the lower right wall WRD, the left wall WL, the upper left wall WLU, and the lower left wall WLD of the left half 101L are all a crankcase 111, a cylinder 112, and a cylinder head 113. It is arranged in the position away from. That is, in a state where the shroud 101 is attached to the engine 6, a space through which air flows is formed between the crankcase 111, the cylinder 112, the cylinder head 113, and the shroud 101.

In the right half 101R, a cylindrical portion C protruding rightward (outward in the vehicle width direction) is provided at the rear portion of the right wall WR, and an opening 1O1a serving as an intake port is provided at the right end of the cylindrical portion C. Is formed. The cylindrical portion C and the opening 1O1a are provided at positions corresponding to the fan 102. That is, with the shroud 101 attached to the engine 6, the fan 102 is disposed in the space on the left side of the cylindrical portion C (in the vehicle width direction).

When the fan 102 rotates in this cooling structure, air is taken into the shroud 101 through the opening 1O1a. The air taken into the shroud 101 flows through a space formed between the shroud 101 and the engine 6. The rotation of the fan 102 creates an air flow in the shroud 101 from the right rear space of the engine 6 to the left front space via the right front space, and the cylinder 112, the cylinder head 113, and The injector 7 is cooled. As described above, a cooling flow path for cooling the cylinder 112, the cylinder head 113, and the injector 7 is formed in the shroud 101.

By the way, when the air whose temperature has risen through the cylinder 112 and the cylinder head 113 is guided to the injector 7 by the cooling flow path, the cooling efficiency of the injector 7 is greatly reduced. Therefore, in the cooling structure according to the present embodiment, a shielding portion that branches the cooling flow path is provided in the shroud 101, and the air flow path for cooling the cylinder 112 and the cylinder head 113 and the injector 7 are cooled. Separate the air flow path.

FIG. 8 is a perspective view showing the configuration of the shielding part. As shown in FIGS. 7 and 8, the shielding portion 103 has a curved shape along the inner wall surface of the right half portion 101 </ b> R of the shroud 101. Specifically, the shielding portion 103 includes an upstream portion 103a disposed along the right wall WR and the upper right wall WRU of the shroud 101, a midstream portion 103b disposed along the right front wall WRF and the upper right wall WRU, And a downstream portion 103 c that forms a flow of air toward the injector 7. By attaching the shielding portion 103 to the inner wall surface of the shroud 101, a branch channel that branches the cooling channel is formed.

Inside the shroud 101 to which the shielding part 103 is attached, an opening 1O2a for taking in air from the fan 102 into the branch flow path is formed by the upstream part 103a, the right wall WR, and the upper right wall WRU. Further, the air flowing in from the opening 1O2a is guided to the left front by the midstream portion 103b, the right front wall WRF, and the upper right wall WRU. Thus, since the branch flow path is formed at a position away from the cylinder 112 and the cylinder head 113 along the inner wall surface of the shroud 101, the propagation of heat from the cylinder 112 and the cylinder head 113 to the branch flow path is prevented. It is suppressed.

In the above cooling structure, the upstream portion 103a is positioned along the air flow from the fan 102, and the branch flow path is bent only in the boundary region between the upstream portion 103a and the midstream portion 103b. For this reason, air can flow smoothly in the branch flow path, and high cooling efficiency can be obtained. In the downstream portion 103c, a rectifying portion 103d that regulates the air flow is disposed in a region in contact with the right front wall WRF. The flow of air toward the injector 7 is adjusted by the rectifying unit 103d, and the cooling efficiency of the injector 7 is enhanced.

Also, the area of the opening 1O2a is sufficiently large, and the flow rate of air necessary for cooling the injector 7 is secured. By changing the area of the opening 1O2a, the flow rate of air for cooling the injector 7 can be adjusted. The shield 103 may be formed of a material different from that of the shroud 101. For example, the propagation of heat from the cylinder 112 and the cylinder head 113 to the branch flow path can be further suppressed by forming the shielding portion 103 using a material having high heat insulating properties. The same effect can be obtained also when a heat insulating member is attached to the shielding part 103.

FIG. 9 is a schematic diagram showing an air flow in the cooling structure according to the present embodiment. As shown in FIG. 9, the air taken into the shroud 101 from the opening 1O1a is sent forward by a fan 102 (not shown in FIG. 9). A part of the air is supplied to the cylinder 112 and the cylinder head 113 through the cooling flow path P1. Another part of the air flows into the opening 1O2a and is blown to the injector 7 through the branch flow path P2. The cylinder 112 and the cylinder head 113 are cooled by the air supplied through the cooling flow path P1, and the injector 7 is cooled by the air blown through the branch flow path P2.

Thus, the cooling efficiency of the injector 7 can be increased by blowing air to the injector 7 through the branch flow path P2 formed exclusively for cooling the injector 7. Since this branch channel P2 is formed so as to sandwich the cooling channel P1 between the cylinder 112 and the cylinder head 113, the cooling channel P1 is not blocked by the branch channel P2. Therefore, the cooling efficiency of the cylinder 112 and the cylinder head 113 is also maintained high.

As described above, according to the engine cooling structure of the present invention, the shroud (wind guide member) 101 has the shielding portion 103 that forms the branch flow path P <b> 2 that guides air to the injector (fuel injection device) 7. Therefore, the injector 7 can be cooled with air different from the air that cools the cylinder 112 and the cylinder head 113. Further, since the branch flow path P2 is formed at a position away from the cylinder 112 and the cylinder head 113, the propagation of heat from the cylinder 112 and the cylinder head 113 to the branch flow path P2 is suppressed, and the cooling efficiency of the injector 7 is reduced. Can be increased. Therefore, an engine cooling structure capable of appropriately cooling components such as the injector 7 affected by the heat of the cylinder 112 and the cylinder head 113 is realized.

Moreover, since the shielding part 103 branched the cooling flow path P1 in the position before the air from the fan (blower member) 102 reached the cylinder 112 and the cylinder head 113, it branches by the heat of the cylinder 112 and the cylinder 113. The temperature rise of the air flowing through the flow path P2 can be prevented. Therefore, the cooling efficiency of components such as the injector 7 can be increased.

Further, since the branch flow path P2 is formed along the inner wall surface of the shroud 101 so as to sandwich the cooling flow path P1 between the cylinder 112 and the cylinder head 113, the branch flow path P2 extends from the cylinder 112 and the cylinder head 113. The propagation of heat to P2 can be further suppressed. Further, since the cooling flow path P1 is not blocked by the branch flow path P2, the cooling efficiency of the cylinder 112 and the cylinder head 113 can be maintained high.

Moreover, since the shielding part 103 is comprised with a member different from the shroud 101, since the freedom degree of a shape increases compared with the case where the shroud 101 and the shielding part 103 are shape | molded integrally, the cooling flow path P1 and It is possible to reliably separate the branch flow path P2 and suppress the propagation of heat from the cylinder 112 and the cylinder head 113 to the branch flow path P2. Moreover, since the material of the shroud 101 and the material of the shielding part 103 can be changed, the heat insulation effect of the shielding part 103 is enhanced, and the propagation of heat from the cylinder 112 and the cylinder head 113 to the branch flow path P2 is further suppressed. Can do.

In addition, this invention is not limited to the said embodiment, It can be implemented in various changes. In the above-described embodiment, the size, shape, and the like illustrated in the accompanying drawings are not limited to this, and can be appropriately changed within a range in which the effect of the present invention is exhibited. In addition, various modifications can be made without departing from the scope of the object of the present invention.

For example, in the above embodiment, the configuration in which the injector is cooled by the air flowing through the branch flow path is exemplified, but the engine cooling structure according to the present invention is not limited thereto. In an engine using a carburetor as a fuel injection device, the carburetor may be cooled with air flowing through a branch flow path. The cooling target may be at least a component different from the cylinder and the cylinder head. Moreover, in this embodiment, although the branch flow path is formed inside the shroud, the branch flow path may be formed outside the shroud.

Further, the shielding part may be configured to be detachable so that the area of the opening of the branch channel can be changed by replacing the shielding part. In this case, the flow rate of the air that cools the injector can be arbitrarily adjusted. In the present embodiment, the shroud and the shielding portion are separate members, but the shroud and the shielding portion may be a single member configured integrally. When the shroud and the shielding portion are integrated, the manufacturing cost of the cooling structure can be suppressed.

The engine cooling structure according to the present invention is useful, for example, as an engine cooling structure in a motorcycle.

1 Motorcycle 6 Engine 7 Injector (fuel injection device)
43 Air cleaner box 44 Intake hose 45 Throttle body 46 Intake manifold 61 Muffler 71 Fuel hose 101 Shroud (air guide member)
101R Right half 101L Left half 102 Fan (Blowing member)
103 Shielding part 103a Upstream part 103b Midstream part 103c Downstream part 103d Rectifying part 111 Crankcase 112 Cylinder 113 Cylinder head 114 Cylinder head cover C Cylindrical part 1O1a, 1O2a Opening P1 Cooling flow path P2 Branch flow path WL Left wall WLD Left lower wall WLU Upper left Wall WR right wall WRD right lower wall WRU upper right wall

Claims

An air guide member that covers a part of the cylinder and cylinder head of the engine and forms a cooling flow path that guides engine cooling air to the cylinder and the cylinder head; and a blower member that sends the air to the cooling flow path An engine cooling structure comprising:
The air guide member has a main body part that forms the cooling passage, and a branch flow path that guides the air to a part other than the cylinder and the cylinder head at a position away from the cylinder and the cylinder head. A cooling structure for an engine, comprising: a shielding portion formed by branching the cooling flow path.
The engine cooling structure according to claim 1, wherein the shielding portion branches the cooling flow path at a position before the air from the air blowing member reaches the cylinder and the cylinder head.
The said branch flow path is formed along the inner wall surface of the said air guide member so that the said cooling flow path may be pinched | interposed between the said cylinder and the said cylinder head. The engine cooling structure described.
The engine according to any one of claims 1 to 3, wherein the shielding portion is a separate member from the main body portion of the air guide member and is formed of a member formed of a different material. Cooling structure.
The engine cooling structure according to any one of claims 1 to 4, wherein the another component is a fuel injection device.