JP2936158B2 - Outboard motor - Google Patents

Description

DETAILED DESCRIPTION OF THE INVENTION A. Object of the Invention (1) Field of Industrial Use The present invention relates to a casing including a driving force transmitting means,
A propeller coupled to the driving force transmitting means and supported at the lower end of the casing; an engine mount member coupled to the upper end of the casing; and a crankshaft mounted on the engine mounting member and interlocking with the driving force transmitting means , An engine to be connected, an oil pan coupled to the lower end of the engine mount member in the casing, an exhaust pipe for discharging exhaust gas from the engine into the casing, and a casing for discharging exhaust gas discharged into the casing into water. The present invention relates to an outboard motor including a main exhaust port provided at a lower portion of the casing and a sub exhaust port provided at an upper portion of the casing to discharge exhaust gas discharged into the casing into the atmosphere.

(2) Prior Art A structure in which an auxiliary exhaust port is provided at an upper portion of a casing for discharging exhaust gas from an engine into the atmosphere during low-speed operation is known, for example, from Japanese Utility Model Laid-Open No. 64-2700.

(3) Problems to be Solved by the Invention In the above-described conventional one, in an exhaust silencer for an outboard motor having a casing composed of an engine cover, an undercover, an extension case, etc. An oil pan surrounded by the outer wall is provided integrally with an undercover having an outer wall continuous up to an end face to be joined with the oil pan, and a seal wall extending between the oil pan and the outer wall is provided. The exhaust pipe penetrates through the seal wall and is opened into the extension case, an exhaust expansion chamber is provided above the seal wall by utilizing an extra space between the outer wall and the oil pan, and an under cover is provided from within the extension case. A sub exhaust passage is provided to the sub exhaust port via the exhaust expansion chamber. So that reduce the exhaust noise by the exhaust silencer chamber.

However, in the above-described conventional device, the structure of the under case is complicated and the number of parts is increased, which has contributed to an increase in product weight.

The present invention has been made in view of such circumstances,
It is an object of the present invention to provide an outboard motor having a simple structure and easy manufacture, wherein an exhaust silencer can be formed using a gasket interposed between an engine mount member and an oil pan.

B. Configuration of the Invention (1) Means for Solving the Problems In order to achieve the above object, the present invention provides a casing including a driving force transmitting means, and a bearing connected to the driving force transmitting means at a lower end of the casing. A propeller, an engine mount member coupled to the upper end of the casing, an engine mounted on the engine mount member and having a crankshaft interlocked and connected to the driving force transmitting means, and an engine mount member in the casing. An oil pan coupled to a lower end, an exhaust pipe for discharging exhaust gas from the engine into the casing, a main exhaust port provided at a lower portion of the casing to discharge exhaust gas discharged into the casing into water,
In an outboard motor including a sub-exhaust port provided at an upper part of the casing to exhaust the exhaust gas discharged into the casing into the atmosphere, between the engine mount member and the casing,
A common gasket is interposed between the member and the oil pan, and a lower surface of the engine mount member is provided on a lower surface of the joint between the member and the oil pan, the opening of which is closed by the gasket. A recess is provided along the joint, and the recess is divided into a plurality of recesses by a partition formed integrally with the lower surface of the engine mount member apart from the joint so as to cross the recess, Those recesses,
The partition wall and the gasket form a plurality of exhaust silence chambers that are arranged in series in an exhaust path between the exhaust pipe and the sub exhaust port, and the gasket has a plurality of first small silencers corresponding to the exhaust silence chamber at the upstream end thereof. A large number of second small holes are respectively formed in the gasket corresponding to the holes and the exhaust silence chamber at the downstream end thereof, and the partition wall has a large number of interconnecting adjacent exhaust silence chambers with the partition wall interposed therebetween. Wherein the third small holes are formed.

(2) Function According to the above specification, a plurality of exhaust silence chambers can be easily formed by using a plurality of recesses on the lower surface of the engine mount member that are easily machined and a gasket, thereby reducing exhaust noise during low-speed operation. This gasket is used as a seal between the engine mount member and the casing and between the mount member and the oil pan, thereby simplifying the structure and reducing the number of parts. In addition, a large number of first and second units are provided on the upper and lower sides of the silencing chamber to enhance the silencing effect.
Small holes can be easily formed in the gasket.

Also, particularly on the lower surface of the engine mount member, a downward recess is provided along the joint portion outside the joint portion between the member and the oil pan, and the concave portion is formed from the joint portion so as to cross the joint. Since the plurality of recesses are defined by being separated by a partition formed integrally on the lower surface of the engine mount member, the capacity of the plurality of exhaust silence chambers is independent of the shape of the oil pan connection portion of the engine mount member. Can be secured sufficiently.

(3) Example Hereinafter, an example of the present invention will be described with reference to the drawings.

First, in FIGS. 1 and 2, a casing 1 is mounted on a stern plate of a hull (not shown) via a support means 2, and an engine E is mounted on an upper portion of the casing 1, and an engine E is mounted on the casing 1. Is transmitted to a propeller 4 supported at a lower portion of the casing 1 via a driving force transmitting means 3 built in the casing 1.

With reference to FIGS. 3 and 4 together, the casing 1
Are an extension case 5 extending vertically and a gear case 7 coupled to a lower end of the extension case 5.
The engine body 8 of the engine E is connected to an engine mount member 6 connected to the upper end of the extension case 5. Moreover, the engine mount member 6
The upper part of the extension case 5 is covered with a cover 9.
A cover 12 consisting of 10 and an engine upper cover 11 is connected to cover the engine E.

The engine E is, for example, a three-cylinder four-stroke engine, and the engine body 8 is coupled to the engine mount member 6 with its crankshaft 13 in a vertical direction.

The driving force transmitting means 3 includes a driving shaft 14 having an axis eccentrically shifted from the axis of the crankshaft 13 and extending in the casing 1 in the vertical direction, and an upper end of the driving shaft 14 and the space between the crankshaft 13. Gear train 15 for interlocking and coupling, and drive shaft
14 includes a pinion shaft 16 coaxially connected to the lower end of the shaft 14, a bevel gear mechanism 18 interposed between the rotation shaft 17 and the pinion shaft 16 connected to the propeller 4, and the bevel gear mechanism 18 is configured to be able to switch between forward and reverse. You. The gear train 15 is accommodated and arranged between the engine mount member 6 as a primary gear case and the engine body 8. Drive shaft 14
The upper end portion is rotatably supported by the engine mount member 6 and the lower end portion is rotatably supported by the gear case 7. The pinion shaft 16 and the bevel gear mechanism 18 are housed and arranged in the gear case 7. You.

Referring to FIGS. 5 and 6, an oil pan 21 for storing lubricating oil is connected to a lower portion of engine mount member 6. The lubricating oil in the oil pan 21 is
The oil is pumped through an oil strainer 22 by an oil pump (not shown) driven by a camshaft or a crankshaft 13 and supplied to each lubricating portion of the engine E. Moreover, the lubricating oil from each lubricating portion is returned from the lower part of the engine body 8 into the oil pan 21 via the engine mount member 6.
That is, at the lower end of the engine body 8, there is provided an engine mount member coupling connecting cylinder portion 23 for accommodating the gear train 15 and coupling to the engine mount member 6. A connecting cylinder 24 for coupling the engine body is provided to be coupled to the lower end surface of the cylinder 23. Moreover, a plate portion 25 having the connecting cylinder portion 24 as a peripheral wall is provided on the upper surface of the engine mount member 6, and lubricating oil from each lubricating portion of the engine E is coupled to the engine mount member at the lower portion of the engine body 8. After being collected in the connecting cylinder portion 23, it flows down to the plate portion 25. In addition, an oil passage 26 that opens at the deepest portion of the plate portion 25 and extends downward and that opens above the oil pan 21 is provided in the engine mount member 6, and the lubricating oil that has flowed down to the plate portion 25 receives the oil passage 26. From the oil pan 21.

At the lower end in the extension case 5, a cooling water pump 30, which is rotationally driven by the drive shaft 14, is provided on the gear case 7.
The water introduced through the filter 31 is pumped up by the cooling water pump 30, and is connected to the cooling water pump 30 and extends from a water supply pipe 32 extending upward to the oil pan 21 and the engine mount. The cooling water is supplied to the cooling water jacket 33 of the engine body 8 via the member 6.

That is, the engine body 8 is provided with three cylinders 35 into which the pistons 34 are slidably fitted, respectively, and the cooling water jacket 33 is provided on the engine body 8 so as to surround the cylinders 35. Can be The lower surface of the engine body 8 is provided with an inlet 36 for guiding the cooling water rising inside the engine mount member 6 to the cooling water jacket 33, and the cooling water discharged from the engine body 8 is supplied to the engine mounting member 6. An outlet 37 leading to the member 6 is provided adjacent to the inlet 36. In addition, a thermostat valve 38 that operates according to the temperature of the cooling water is disposed at the upper end of the cooling water jacket 33. The cooling water jacket 33 is connected to the outlet 36 and provided in the cooling water passage provided in the engine body 8. 39 is connected via the thermostat valve 38.

At the upper end of the oil pan 21, an outer edge is formed by extending a part of the connection portion with the engine mount member 6 to the side, and the outer edge is connected to the upper end of the water supply pipe 32. A concave portion 43 having an opening 42 at a lower closed end is provided to open upward. The engine mount member 6 has a water rising passage 44 formed between the recess 43 and the inlet 36 of the engine body 8, and a water descending passage 45 communicating with the outlet 36 of the engine body 8. Drilled.

On the other hand, an exhaust passage 46 for discharging exhaust gas is provided in the engine body 8, and an exhaust passage 47 communicating with the exhaust passage 46 is formed in the engine mount member 6 so as to extend up and down. An exhaust passage 48 communicating with the exhaust passage 47 extends vertically and is also formed at the outer edge portion at the upper end of the, and an exhaust pipe 49 extending downward in the extension case 5 is connected to the exhaust passage 48. The exhaust gas discharged from the engine E is supplied to the extension case 5
Will be discharged inside. In addition, the extension case 5 is provided with a sub-exhaust port 50 for discharging exhaust gas into the atmosphere during low-speed operation, and is opened above the water surface at the rear side. A main exhaust port 41 for discharging air to the rear is opened rearward at a position higher than the propeller 4.

That is, the exhaust gas pressure in the extension case 5 and the gear case 7 changes according to the operation state, and the exhaust gas pressure is relatively low during low-speed operation, so that the water surface in the casing 1 is located higher than the main exhaust port 41, Exhaust gas is discharged into the atmosphere from the upper auxiliary exhaust port 50. In high-speed operation, the exhaust gas pressure is relatively high.
The inner water surface is located below the main exhaust port 41, and the exhaust gas is discharged into the water from the main exhaust port 41.

Referring also to FIG. 7, the engine mount member 6 and the extension case 5, and the engine mount member 6 and the oil pan 21 are connected in the same plane. The members 6 are connected to each other with a common gasket 27 interposed therebetween. That is, at the lower part of the engine mount member 6, an oil pan coupling connecting cylinder 28 corresponding to the upper opening edge of the oil pan 21 and an extension case coupling coupling cylinder 29 for coupling with the extension case 5 are provided. Is provided, the extension case coupling connecting cylinder 29 is formed so as to surround the oil pan coupling coupling cylinder 28,
The lower end surfaces of the two connection cylinder portions 28, 29, that is, the coupling surfaces 28a, 29a are formed on the same plane. Thus, the gasket 27 is formed in a flat plate shape with the outer periphery of the extension case coupling connecting tube portion 29 as the outer peripheral edge and the inner periphery of the oil pan coupling connecting tube portion 28 as the inner peripheral edge. Recess
An opening 51 for communicating the water passage 43 of the engine mount member 6 with the water rising passage 44;
An opening for communicating the exhaust passage 47 and the exhaust passage 48 of the oil pan 21
52.

Therefore, the oil pan 21
The fall of the lubricating oil into the inside, the rising of the cooling water from the outer edge of the oil pan 21 to the engine mount member 6, and the flow of the exhaust gas from the engine mount member 6 to the outer edge of the oil pan 21 are performed via the gasket 27. Although it is performed freely, the cooling water flowing downward in the water descending passage 45 provided in the engine mount member 6 is blocked by the gasket 27 from flowing to the oil pan 21 side. Thereby, the gasket 27 also has a function of forming the cooling water passage 55 for guiding the cooling water flowing down from the engine E to the downstream, and the first and second exhaust silence chambers 58 and 59 with the engine mount member 6. Will fulfill.

That is, in the engine mount member 6, the water descending passage 45 is provided to be opened between the connecting cylinder 28 for connecting the oil pan and the connecting cylinder 29 for connecting the extension case. A pair of partition walls 53 and 54 are provided between the connecting cylinder portion 28 for connecting the oil pan and the connecting cylinder portion 29 for connecting the extension case so as to define the area including the partition as one section. Accordingly, the connection pipe section 28 for connecting the oil pan, the connection pipe section 29 for connecting the extension case, the partition walls 53 and 54, and the gasket 27 allow the cooling water passage 55 to be located outside the upper open end of the oil pan 21.
Is formed. Further, a plurality of cooling water discharge ports 56 are formed in the gasket 27 at a portion corresponding to the cooling water passage 55.

Referring again to FIG. 3, an inner wall 5a is provided at a rear portion of the extension case 5 so as to extend inward from the outer wall and outward from the oil pan 21. A partition wall 57 abutting on the upper end via the gasket 27 is provided between the connecting cylinder portion 28 for connecting the oil pan and the connecting cylinder portion 29 for connecting the extension case in the engine mount member 6. Thus, the engine mount member 6 is formed with the first concave portion 6a which is opened downward to be closed by the gasket 27 by the partition walls 53, 54, 57 and the connecting cylinder portion 28 for oil pan connection,
A second concave portion 6b which is opened downward to be closed by the gasket 27 is formed between the connecting cylinder portion 29 for connecting the extension case and the partition wall 57. Thus, the first and second
The concave portions 6a and 6b constitute a concave portion of the present invention as a whole, and also constitute a plurality of concave portions of the present invention in which the concave portion is divided by the partition wall 57.

Thus, between the engine mount member 6 and the gasket 27, except for the cooling water passage 55, a first exhaust silencer 58 is defined by the first recess 6a and the gasket 27, and the second recess 6b and A second exhaust silencer 59 is defined between the gaskets 27. The third outer case, the inner wall 5a and the gasket 27 of the extension case 5 make the third case possible.
An exhaust silencer 60 is defined, and the sub exhaust 50 is a third exhaust silencer.
The extension case 5 is provided on the rear outer wall of the extension case 5 in a row.

The gasket 27 has a plurality of exhaust introduction holes as first small holes at a portion corresponding to the first exhaust silence chamber 58 to guide exhaust gas discharged from the exhaust pipe 49 into the extension case 5 to the first exhaust silence chamber 58. 61 is drilled and a second exhaust gas is introduced from the second exhaust silencer 59 to the third exhaust silencer 60.
A large number of second exhaust holes 62 are formed in portions corresponding to the third exhaust silence chambers 59 and 60. Also partition wall 57
Are provided with a number of third small holes 63 for guiding exhaust gas from the first exhaust silencer 58 to the second exhaust silencer 59.

8, the support means 2 includes a stern bracket 65 attached to the stern plate of the hull, a swivel case 66 connected to the stern bracket 65 in a tiltable manner, and a swivel case 66. A swivel shaft 67 rotatably supported, an upper support arm 68 provided above the swivel shaft 67, a lower support arm 69 provided below the swivel shaft 67, an upper support arm 68 and the engine mount member 6.
A pair of elastic members 70 connecting between them, and a pair of elastic members connecting between the lower support arm 69 and the extension case 5
71.

A cylinder 72 connected to the swivel case 66 is clevis supported on the stern bracket 65 to tilt the swivel case 66.

The upper support arm 68 is formed so that the distal end side is branched into two branches, and a side surface of the engine mount member 6 on the support means 2 side so that the elastic members 70 attached to the distal ends of the upper support arm 68 are fixedly fitted. Is provided with a pair of fitting recesses 73.

Next, the operation of this embodiment will be described. The cooling water supplied to the engine E from the cooling water pump 30 is guided from the cooling water passage 39 to the water descending passage 45 after the cooling of the engine main body 8, and the engine mounting member 6 and gasket 7
It is sent to a cooling water passage 55 formed therebetween. Therefore, the relatively high-temperature lubricating oil returning from the engine E to the oil pan 21 is cooled by the engine mount member 6 which comes in contact with the oil pan 21 as a result, and as a result, the oil temperature may rise excessively even if continuous full-load operation is continued. Since this is avoided and the intake air temperature is prevented from rising, the charging efficiency of the engine E does not decrease. Excessive temperature rise of the engine mount member 6 due to exhaust gas flowing through the exhaust passage 47 is avoided by the water rising passage 44, and lubricating oil returning from each lubricating portion of the engine E to the oil pan 21 via the engine mount member 6 is removed. Heating by the engine mount member 6 is also prevented.

In addition, the cooling water in the cooling water passage 55 falls from the plurality of cooling water discharge ports 56 provided in the gasket 27 to the periphery of the oil pan 21.
21 itself is cooled, thereby preventing lubricating oil from being overheated more effectively.

By the way, exhaust gas from the engine E during low-speed operation is
The exhaust gas is discharged from the exhaust pipe 49 into the extension case 5 through the exhaust passages 46, 47, and 48. The exhaust gas introduction hole 61, the first exhaust silence chamber 58, the conducting hole 63, the second exhaust silence chamber 59, the exhaust outlet hole 62, The exhaust gas is discharged from the sub exhaust port 50 to the outside through the third exhaust silencer 60. By passing through such an exhaust path, the passage resistance can be increased while securing the passage area of the exhaust gas, and therefore, it is possible to contribute to the reduction of the exhaust noise during low-speed operation.

C. Effects of the Invention As described above, according to the present invention, a common gasket is interposed between the engine mount member and the casing, and between the member and the oil pan, and the lower surface of the engine mount member is provided with the member. A plurality of downward recesses are provided outside the coupling portion between the exhaust pipe and the oil pan, and the plurality of recesses and the gasket form a plurality of exhaust silence chambers interposed in series in an exhaust path between the exhaust pipe and the sub exhaust port. A number of first small holes are formed in the gasket corresponding to the exhaust muffle chamber at the upstream end, and a plurality of second small holes are formed in the gasket corresponding to the exhaust muffle chamber at the downstream end. Since a large number of third small holes are formed in the partition wall between the adjacent concave portions, a plurality of exhaust sound-absorbing chambers are easily formed by using a plurality of concave portions on the lower surface of the engine mount member that are easy to process and a gasket. It is possible to contribute to the reduction of the exhaust noise at the time of low-speed operation, and therefore, the gasket is also used in combination with the sealing means between the engine mount member and the casing and between the mount member and the oil pan. Since this can greatly contribute to the simplification of the structure and the reduction of the number of parts, cost reduction and improvement in mass productivity can be achieved while reducing weight. In addition, since a large number of first and second small holes respectively provided on the upper and lower sides of the silencing chamber to enhance the silencing effect can be easily formed in a gasket,
It is possible to further reduce costs and improve mass productivity while securing a sufficient noise reduction effect.

Also, particularly on the lower surface of the engine mount member, a downward recess is provided along the joint portion outside the joint portion between the member and the oil pan, and the concave portion is formed from the joint portion so as to cross the joint. Separated by a partition formed integrally on the lower surface of the engine mount member so as to define the plurality of recesses, so that regardless of the shape of the oil pan connection portion of the engine mount member, the plurality of exhaust The capacities can be sufficiently secured, and the exhaust noise silencing effect is improved accordingly, and the setting for enhancing the noise silencing effect is facilitated.

[Brief description of the drawings]

BRIEF DESCRIPTION OF THE DRAWINGS The drawings show an embodiment of the present invention, FIG. 1 is an overall side view of an outboard motor, FIG. 2 is a sectional view taken along line II-II of FIG.
3 is a partially enlarged longitudinal sectional side view taken along the line III-III of FIG. 2, FIG. 4 is a sectional view taken along the line IV-IV of FIG. 3, FIG. 5 is a sectional view taken along the line VV of FIG. FIG. 6 is a sectional view taken along line VI-VI of FIG. 3,
7 is a sectional view taken along the line VII-VII of FIG. 3, and FIG. 8 is a sectional view of FIG.
It is a VIII-VIII line expanded sectional view. DESCRIPTION OF SYMBOLS 1 ... Casing, 3 ... Driving force transmission means, 4 ... Propeller, 6 ... Engine mount member, 6a, 6b ... recess
First and second concave portions as a plurality of concave portions, 21... An oil pan,
27 …… Gasket, 41 …… Main exhaust port, 49 …… Exhaust pipe, 50
… Auxiliary exhaust port, 57… Partition wall, 58,59… First and second noise reduction chambers as exhaust noise reduction chambers, 61… Exhaust introduction holes as first small holes, 62… as second small holes Exhaust outlet hole, 63 ... Conductor hole as third small hole, E ... Engine

──────────────────────────────────────────────────続 き Continued on the front page (58) Field surveyed (Int.Cl. ⁶ , DB name) F01N 7/12

Claims (1)

(57) [Claims] 1. A casing (1) containing a driving force transmitting means (3), a propeller (4) connected to the driving force transmitting means (3) and supported at a lower end of the casing (1), and a casing. An engine mount member (6) coupled to the upper end of (1), and a crankshaft (13) mounted on the engine mount member (6) and driving force transmitting means (3).
And an oil pan (21) connected to the lower end of the engine mount member (6) in the casing (1), and exhaust gas from the engine (E) is placed in the casing (1). An exhaust pipe (49) to be discharged, a main exhaust port (41) provided at a lower portion of the casing (1) for discharging exhaust gas discharged into the casing (1) into water,
An outboard motor including a sub-exhaust port (50) provided at an upper portion of the casing (1) for discharging exhaust gas discharged into the casing (1) into the atmosphere, wherein the engine mount member (6) and the casing ( 1)
A common gasket (27) is interposed between the member (6) and the oil pan (21), and the member (6) and the oil pan (21) are provided on the lower surface of the engine mount member (6). )
On the outside of the joint, the gasket (27) is provided with a downward recess (6a, 6b) whose opening is closed along the joint, and the recess (6a, 6b) A partition wall (57) integrally formed on the lower surface of the engine mount member (6) is separated from the coupling portion so as to cross the concave portion and is divided into a plurality of concave portions (6a, 6b). The partition wall (57) and the gasket (27) form a plurality of exhaust silence chambers (58, 59) that are interposed in series in an exhaust path between the exhaust pipe (49) and the sub exhaust port (50). The gasket (27) has a number of first small holes (61) corresponding to the exhaust silencer (58) at the upstream end, and the gasket (27) corresponds to the exhaust silencer (59) at the downstream end. A large number of second small holes (62) are formed in the partition wall (57). Room (58,5
9) An outboard motor, wherein a number of third small holes (63) are formed to communicate with each other.