JP2005256763A - Intake air cooling structure for outboard motor - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To cool an intake manifold while suppressing enlargement of an engine. <P>SOLUTION: The intake manifold 31 includes intake branch pipes 33(1)-33(4). A vapor separator 24 is provided in a space IS formed between the intake branch pipe 33 and a cylinder block 13 together with an intake manifold cooler 30. The intake manifold cooler 30 includes a cooling water passage 38 and a plurality of ribs 31a, and is provided from the lowermost intake branch pipe 33 over the uppermost intake branch pipe 33(4). The cooling water passage 38 is formed by covering a left side part of the intake manifold 31 from a left side by a cover body 34. The cover body 34 has a shape which has a notch at a lower section on a rear side in a side view, and includes an inclined part 34a facing obliquely rear downward, and cross section the cooling water passage 38 in a horizontal direction gets larger as it goes upper. <P>COPYRIGHT: (C)2005,JPO&NCIPI

Description

  The present invention relates to an intake air cooling structure for an outboard motor equipped with a vertical water-cooled multi-cylinder engine having an intake manifold.

Conventionally, in an outboard motor, the intake manifold is usually made of metal and is heated by heat radiation from the cylinder block or the crankcase. An outboard motor intake cooling structure is known in which a cooling water passage is provided inside the intake manifold, that is, on the side of the intake manifold on the cylinder block or crankcase side to cool the intake manifold. An outboard motor in which an engine auxiliary machine such as a vapor separator is provided in the engine is also known.
JP-A-6-123225 JP-A-7-305631

  However, in recent years, where downsizing of the engine is required, especially in an outboard motor provided with a cooling water passage for an intake manifold, it may lead to an increase in the size of the engine unless the layout of the engine auxiliary equipment is sufficiently examined. .

  In an outboard motor equipped with a so-called vertical multi-cylinder engine in which the crankshaft is arranged along the vertical direction, the upper cylinder is usually hotter than the lower cylinder. In general, engine cooling water is supplied from below and discharged from the upper part, the upper cylinder is more susceptible to the heat generated by the flywheel magneto arranged in the upper part of the engine, and the engine cover This is due to the fact that the upper temperature distribution is higher. As a result, the intake branch pipe (intake branch) corresponding to each cylinder of the intake manifold also becomes hotter as the upper intake branch pipe. The tendency becomes stronger as the number of cylinders increases.

  Therefore, in order to sufficiently reduce the intake air temperature in the uppermost intake branch pipe, which is the highest temperature, it is necessary to increase the capacity of the cooling water passage accordingly. However, simply increasing the capacity of the cooling water passage leads to space saving and increases the size of the engine.

  The present invention has been made to solve the above-described problems of the prior art, and an object thereof is to provide an intake air cooling structure for an outboard motor capable of cooling an intake manifold while suppressing an increase in size of the engine. There is.

  In order to achieve the above object, an outboard motor intake air cooling structure according to claim 1 of the present invention is a water-cooled multi-cylinder engine having a fuel injection device, a cylinder block having a plurality of cylinders, and an intake manifold. Are arranged in parallel in the vertical direction, and the intake air cooling structure of the outboard motor mounted vertically, wherein the intake manifold is formed in a space formed between the cylinder block and the intake manifold. A cooling water passage for cooling the engine and an engine accessory are provided.

  In order to achieve the above object, an outboard motor intake air cooling structure according to claim 3 of the present invention is a water-cooled multi-cylinder engine including a fuel injection device and a cylinder block having a plurality of cylinders. An outboard motor air intake cooling structure that is mounted vertically so as to be arranged in parallel with each other, and having a plurality of intake branch pipes arranged in parallel in the vertical direction corresponding to each cylinder In the space formed between the intake manifold and the cylinder block and the intake manifold, the intake manifold is disposed from the height of the lowermost intake branch pipe to the height of the uppermost intake branch pipe. A cooling water passage for cooling, and the cooling water passage is configured such that a horizontal sectional area of the cooling water passage increases upward.

  According to the intake air cooling structure for an outboard motor according to claim 1 of the present invention, it is possible to cool the intake manifold and dispose the engine auxiliary equipment while suppressing the enlargement of the engine.

  According to the intake air cooling structure for an outboard motor according to claim 3 of the present invention, the intake manifold can be efficiently cooled while suppressing the enlargement of the engine.

  Hereinafter, embodiments of the present invention will be described with reference to the drawings.

  FIG. 1 is a right side view of an outboard motor to which an outboard motor intake air cooling structure according to an embodiment of the present invention is applied. Hereinafter, for the outboard motor 1 of the present embodiment, the right side (the hull side) of the figure is referred to as “front”, the left side as “rear”, and the upper side as “upward”. FIG. 2 is a right side view of the engine portion of the outboard motor 1. 3 is a schematic diagram of a cross section taken along line III-III in FIG.

  As shown in FIG. 1, the outboard motor 1 includes an engine holder 3, and the engine 2 is installed above the engine holder 3. The engine 2 is a water-cooled four-cycle in-line four-cylinder engine in which a crankshaft 15 (see FIG. 3) is disposed substantially vertically (vertically). Accordingly, each cylinder 26 (one shown in FIG. 3) of the cylinder block 13 to be described later is arranged in parallel in the vertical direction.

  An oil pan 4 is joined and fixed to the lower surface of the engine holder 3, and a drive shaft housing 9 and a gear case 10 are sequentially arranged below the oil pan 4. The engine cover 5 surrounds the engine 2, the engine holder 3, and the oil pan 4. Covered.

  A drive shaft (not shown) is disposed substantially vertically in the engine holder 3, the oil pan 4, and the drive shaft housing 9. The drive shaft receives rotational force from the crankshaft 15, and the bevel gear and the propeller shaft ( The propeller 6 which is a propulsion device is configured to be driven via any of them (not shown).

  A bracket 28 is fixed to the engine holder 3, and the outboard motor 1 is fixed to a stern plate of a hull (not shown) via the bracket 28.

  As shown in FIG. 1, a water pump 27 driven by the drive shaft is installed on the upper part of the gear case 10. The gear case 10 is provided with a water inlet 8, and external water (seawater, lake water, river water, etc.) is taken in as cooling water from the water inlet 8 by the water pump 27. The cooling water cools an intake manifold 31 and the like which will be described later, and the water that has returned after performing the cooling function is discharged together with the exhaust gas from the center hole (not shown) of the propeller 6 into the water outside the outboard motor 1.

  As shown in FIGS. 2 and 3, a cylinder block 13 and a cylinder head 12 are sequentially arranged behind the crankcase 14 arranged at the foremost part (the bow side) of the engine 2. A head cover 11 is mounted. The crankshaft 15 is pivotally supported on the joint surface portion between the crankcase 14 and the cylinder block 13. As shown in FIG. 3, the reciprocating motion of the piston 41 slidably inserted into the cylinder 26 is converted into the rotational motion of the crankshaft 15 via the connecting rod 39.

  As shown in FIG. 2, a low pressure fuel filter 19 and a fuel pump 20 are disposed at the rear of the engine 2, and a fuel cooler 17 and a delivery pipe 21 are both disposed in the vertical direction. A fuel hose 23 is disposed at the lower right side of the engine 2 and is connected to the low pressure fuel filter 19. A high pressure fuel filter 18 is disposed at the upper part of the engine 2. Further, an oil filter 16 is disposed at the lower right portion of the cylinder block 13, and a cooling water hose 22 disposed at the rear lower portion of the right side portion of the engine 2 is connected to the fuel cooler 17.

  A vapor separator 24 is disposed in a space IS formed between the intake branch pipe 33 and the cylinder block 13. The vapor separator 24 is fixed to the left side of the intake manifold 31 with a bolt or the like. The vapor separator 24 includes a pressure regulator and a high-pressure pump (not shown), and is connected to the fuel pump 20 by a fuel hose 40 and to the delivery pipe 21 via the high-pressure fuel filter 18.

  An intake manifold 31 is provided on the right side of the engine 2. The intake manifold 31 includes a surge tank 32 and four intake branch pipes 33 (33 (1) to 33 (4)). The intake branch pipes 33 (1) to 33 (4) are arranged in parallel in the vertical direction corresponding to each cylinder 26, and the surge tank 32 and the corresponding intake port 42 (see FIG. 3) of the cylinder head 12. Is in communication. Each intake port 42 is provided with an injector 25 (25 (1) to 25 (4)).

  The fuel pump 20 sucks fuel from a tank (not shown) through the fuel hose 23 and the low-pressure fuel filter 19 and supplies the fuel to the vapor separator 24. The vapor separator 24 separates the vapor from the supplied fuel. The fuel from which the vapor has been separated is pumped from the vapor separator 24 to the high-pressure fuel filter 18 and injected from each injector 25 into the corresponding intake port 42 via the delivery pipe 21.

  On the right side of the engine 2, a cooling unit (hereinafter referred to as “in-manicooler”) 30 for cooling the intake manifold 31 is provided. The intake manifold cooler 30 is disposed in a space IS formed between the intake branch pipe 33 and the cylinder block 13, and includes a cooling water passage 38 and a plurality of ribs 31a.

  That is, as shown in FIG. 3, the cooling water passage 38 is formed by covering the side portion (left side portion) of the intake manifold 31 facing the cylinder block 13 from the left side with the cover body 34. The cover body 34 is fixed to the intake manifold 31 with screws or the like. On the left side of the intake manifold 31, a plurality of ribs 31 a are integrally formed so as to protrude into the cooling water passage 38. The rib 31a increases the surface area in contact with the cooling water and plays the role of a cooling fin. As shown in FIG. 2, the cooling water passage 38 is provided with a cooling water inlet 35 at the lower part and a cooling water outlet 36 at the upper part.

  As shown in FIG. 2, the intake manifold 30 is provided from the uppermost intake branch pipe 33 (1) to the lowermost intake branch pipe 33 (4). The cover body 34 has a shape in which a lower part on the rear side in a side view (when the outboard motor 1 is viewed from the right side) is cut off, and specifically includes an inclined portion 34a that faces obliquely rearward and downward, The inclined portion 34 a is also the inclined portion 30 a of the intake manifold cooler 30. Thereby, it is comprised so that the horizontal cross-sectional area of the cooling water channel | path 38 may become large as it goes upwards. Each rib 31a extends in the up-down direction, and the length in the up-down direction is shorter from the rib 31a in the middle in the front-rear direction to the rear rib 31a according to the inclination of the inclined portion 30a. As a result, the number of ribs 31 a increases as it goes above the intake manifold cooler 30. With these configurations, the cooling effect of the intake manifold cooler 30 is increased toward the top.

  On the other hand, the vapor separator 24 is located in the space IS together with the intake manifold cooler 30. Moreover, the vapor separator 24 is disposed obliquely rearward and downward of the intake manifold cooler 30 in the vicinity of the inclined portion 30 a of the intake manifold cooler 30. That is, since the space in the side view is secured by the notched portion of the cover body 34 in the side view, the vapor separator 24 is disposed using this space. Thereby, the vapor separator 24 and the intake manifold cooler 30 can be arranged without difficulty, and the enlargement of the engine 2 is avoided.

  The cooling water taken from the water inlet 8 by the water pump 27 (see FIG. 1) is first introduced into the cooling water passage 38 from the cooling water inlet 35 (see FIG. 2), and as shown in FIG. , The intake manifold 31 is cooled mainly through the ribs 31a to lower the intake air temperature, and then discharged from the cooling water outlet 36. The cooling water taken in from the water intake port 8 also cools each part of the engine 2 and is also supplied to the fuel cooler 17 through, for example, the cooling water hose 22 to cool the fuel and be discharged from the upper part of the fuel cooler 17. The

  According to the present embodiment, the horizontal cross-sectional area of the cooling water passage 38 increases as it goes upward, and the number of the ribs 31a increases toward the upper side of the intake manifold 30. Therefore, the intake manifold 30 includes a plurality of intake branches. A higher cooling effect is exerted on the upper one of the pipes 33 that is hotter. Therefore, compared with the case where the intake manifold cooler 30 is configured so as to ensure a large cross-sectional area over the entire vertical direction in accordance with the uppermost intake branch pipe 33 (1), a compact cooling water passage is formed. Since all the intake manifolds 31 can be cooled reasonably, the increase in size of the engine 2 can be suppressed while maintaining appropriate cooling efficiency as a whole.

  Moreover, the cooling water passage 38 is formed by covering the intake manifold 31 from the left side with the cover body 34, and the rib 31a is formed to protrude into the cooling water passage 38, so that the cooling efficiency can be improved with a simple configuration. Can be increased.

  According to the present embodiment, the vapor separator 24 and the intake manifold cooler 30 are disposed in the space IS using the space IS formed between the intake branch pipe 33 and the cylinder block 13. In realizing cooling of the intake manifold 31 and disposition of the vapor separator 24, it is possible to suppress an increase in size of the engine. In particular, the shape of the side view of the intake manifold cooler 30 is devised as described above, and the vapor separator 24 is disposed close to the inclined portion 30a obliquely rearward and downward of the intake manifold cooler 30 so that the notched portion by the inclined portion 30a is vaporized. Since it corresponds to the escape portion with respect to the separator 24, both the vapor separator 24 and the intake manifold cooler 30 can be easily arranged in a narrow space. Moreover, the fact that the inclined portion 30a is formed in the intake manifold cooler 30 is convenient for efficiently cooling the upper intake branch pipe 33 by changing the cross-sectional area in the vertical direction as described above. This is advantageous in that it is not a structural restriction.

  In addition, when employ | adopting the structure which enlarges the cross-sectional area of the horizontal direction of the cooling water channel | path 38 of the intake manifold cooler 30 upwards, the arrangement position of the vapor separator 24 is not limited to the back lower direction of the intake manifold cooler 30. FIG. For example, what is necessary is just to consider how to reduce the outer shape in order to reduce the cross-sectional area below the cooling water passage 38 and the arrangement position of the vapor separator 24.

  The engine accessory disposed in the space IS together with the intake manifold cooler 30 is not limited to the vapor separator 24, and may be another engine accessory.

  The application of the present invention is not limited to a 4-cylinder outboard motor, and the present invention can be applied to an outboard motor equipped with a water-cooled multi-cylinder engine.

1 is a right side view of an outboard motor to which an outboard motor intake air cooling structure according to an embodiment of the present invention is applied. It is a right view of the engine part of an outboard motor. It is a schematic diagram of the cross section along the III-III line of FIG.

Explanation of symbols

DESCRIPTION OF SYMBOLS 1 Outboard motor 2 Engine 13 Cylinder block 24 Vapor separator (engine auxiliary machine)
25 Injector (fuel injection device)
26 cylinder 30 intake manifold cooler 30a inclined portion 31 intake manifold 31a rib 32 surge tank 33 intake branch pipe 34 cover body 38 cooling water passage IS space

Claims (5)

A water-cooled multi-cylinder engine (2) including a fuel injection device (25), a cylinder block (13) having a plurality of cylinders, and an intake manifold (31) is arranged such that each cylinder is arranged in parallel in the vertical direction. In addition, the outboard motor intake cooling structure mounted vertically,
A cooling water passage (38) and an engine accessory (24) for cooling the intake manifold are disposed in a space (IS) formed between the cylinder block and the intake manifold. An outboard motor intake cooling structure.   The cooling water passage has an inclined portion (30a) that faces obliquely downward in a lower portion on one side in the side view, and the engine accessory is adjacent to the inclined portion in the oblique lower portion of the cooling water passage. The outboard motor intake air cooling structure according to claim 1, wherein the outboard motor intake air cooling structure is disposed. A water-cooled multi-cylinder engine (2) having a fuel injection device (25) and a cylinder block (13) having a plurality of cylinders is mounted vertically so that each cylinder is arranged in parallel in the vertical direction. An outboard motor intake air cooling structure,
An intake manifold (31) having a plurality of intake branch pipes (33) arranged in parallel in the vertical direction corresponding to each cylinder;
In the space (IS) formed between the cylinder block and the intake manifold, the height of the uppermost intake branch pipe (33 (1)) from the height of the lowermost intake branch pipe (33 (4)). A cooling water passage (38) disposed at a height for cooling the intake manifold,
An outboard motor intake air cooling structure, wherein the cooling water passage is configured such that a horizontal sectional area of the cooling water passage increases upward.   The cooling water passage is formed by covering a side portion of the intake manifold facing the cylinder block with a cover body (34), and a rib (31a) is formed in the side portion in the cooling water passage. The outboard motor intake air cooling structure according to claim 3, wherein the intake air cooling structure is provided so as to protrude toward the outside.   5. The outboard motor intake air cooling structure according to claim 4, wherein the cooling water passage is configured so that the number of the ribs increases upward.

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