JP4530577B2 - Intake device for V-type engine for outboard motor - Google Patents

Description

[0001]
BACKGROUND OF THE INVENTION
The present invention relates to an intake device for a V-type engine for an outboard motor that is disposed with a crankshaft vertically and heads of left and right banks facing backwards, and is covered with an engine hood. This relates to an intake system for an engine for an outboard motor, in which the intake characteristics are changed so that high output performance can be exhibited in a wide operating range from low speed to high speed of the engine.
[0002]
[Prior art]
In an outboard engine intake system, an effective pipe length of the intake system is switched according to the operating state of the engine to satisfy the output performance in a wide operating range, for example, according to Japanese Patent Laid-Open No. 10-61446. It is known.
[0003]
[Problems to be solved by the invention]
However, in the device disclosed in the above publication, since the intake pipe extending in the front-rear direction is arranged on one side of the engine in the left-right direction, the width of the engine hood that covers the engine provided with this intake pipe inevitably increases. However, it is inevitable to increase the size. In particular, when the above apparatus is applied to a vertical V-type engine, the tendency becomes remarkable.
[0004]
The present invention has been made in view of such circumstances, and while enabling a compact configuration to avoid an increase in the size of the engine hood, the intake characteristics are changed in accordance with the operating state of the engine, and the engine speed is reduced. An object of the present invention is to provide an outboard motor V-type intake system capable of exhibiting high output performance in a wide operating range over high speeds.
[0005]
[Means for Solving the Problems]
In order to achieve the above object, the present invention is an intake device for a V-type engine for an outboard motor, which is arranged with the crankshaft vertically and the heads of the left and right banks facing rearward and covered with an engine hood. In addition, an intake inlet connected to the intake passage of the throttle body is provided on one end in the vertical direction of the intake distribution box that is flat between the heads of the left and right banks and the rear wall of the engine hood. The inside of the intake distribution box is divided into left and right distribution chambers that communicate with the intake inlet and extend in the vertical direction by partition walls, and an on-off valve is provided on the partition wall that can communicate and block between the left and right distribution chambers, The left and right intake branch pipes that open to the left and right distribution chambers and that respectively connect to the intake ports of the left and right banks are integrated with the front wall of the intake distribution box so that they are arranged in the intake distribution box. In To form, the intake air-dispensing box, the intake inlet, which has a half portion of the left and right intake branch pipes and the partition wall, an opening over between the left and right distribution chamber opposite to the left and right intake branch pipes A distribution box main body provided on an outer wall; and a light metal cast lid having a second half of the partition and removably coupled to the distribution box main body so as to close the opening. The on-off valve is mounted on a valve shaft that is rotatably supported on the other half and extends in the vertical direction, and an operating lever is fixed to an outer end portion of the valve shaft that projects to the other end in the vertical direction of the intake distribution box. Then, an actuator for rotating the operation lever to open and close the on-off valve is attached to the other end of the intake distribution box, and is housed in the area of the vertical projection figure of the intake distribution box , Divide the valve hole along the bearing hole in the other half So that the, divided into a partition wall other half principal and the partition piece, the first, characterized in that the partition wall strip is bolted to the bulkhead other half entity.
[0006]
According to the first feature, the resonance supercharging intake system corresponding to the low speed and high speed operation of the engine can be configured by opening and closing the on-off valve, and high output performance can be exhibited in a wide range of operation. Moreover, since the intake distribution box that is flat in the front-rear direction is arranged close to the heads of the left and right banks of the engine, the intake distribution box should be arranged in a narrow space between the engine and the rear side wall of the engine hood. Can do. As a result, the space efficiency of the engine room can be improved and the engine hood can be prevented from being enlarged.
[0007]
Since the lid and the on-off valve constitute a single assembly, the on-off valve and its surroundings can be easily maintained by removing the lid from the distribution box body, improving maintenance. Can contribute.
[0008]
Moreover, since the lid made of light alloy casting is smaller and simpler in shape than the distribution box body integrated with the suction branch pipe, precision casting such as high-pressure die casting becomes possible. Therefore, it is easy to obtain a high-quality lid that does not require post-processing of the valve hole, is highly rigid, and does not cause distortion even when the ambient temperature changes. Can be ensured at all times regardless of changes in ambient temperature.
[0009]
Furthermore, the position of the actuator that opens and closes the on-off valve can be set freely around the valve shaft by selecting the coupling position of the operating lever with respect to the valve shaft of the on-off valve. It is easy to fit in the area of the figure, and therefore interference between the actuator and the rear wall of the engine hood adjacent to the rear surface of the intake distribution box can be easily avoided. In addition, since the intake inlet and the actuator are arranged at both upper and lower ends of the intake distribution box, interference between them can be avoided and the intake device can be made compact.
[0010]
Furthermore, the other half part of the partition wall is divided into the main part of the other half part of the partition wall and the partition piece so that the valve hole is divided along the bearing hole. , Half of the valve holes can be easily molded. After casting, troublesome valve hole processing is not required, and productivity can be improved.
[0011]
In addition to the first feature, the present invention has a second feature in that a recess is formed in a lower end surface of the intake distribution box, and the actuator is disposed obliquely forward so as to be received in the recess. To do.
[0012]
According to this second feature, a relatively large actuator can be installed in a narrow engine room without interfering with the intake distribution box and the engine hood.
[0013]
DETAILED DESCRIPTION OF THE INVENTION
The form of the Example of this invention is demonstrated below based on one Example of this invention shown to an accompanying drawing.
[0014]
1 is an overall side view of the outboard motor, FIG. 2 is a longitudinal sectional view of the main part of FIG. 1, FIG. 3 is a sectional view taken along line 3-3 in FIG. 2, and FIG. 5 is a sectional view taken along line 5-5 in FIG. 4, FIG. 6 is a sectional view taken along line 6-6 in FIG. 5, FIG. 7 is a sectional view taken along line 7-7 in FIG. 9 is a sectional view taken along line 9-9 of FIG. 8, FIG. 10 is an enlarged view of 10 part of FIG. 9, FIG. 11 is a view taken along arrow 11 in FIG. 8, and FIG. FIGS. 13A and 13B are sectional views taken along line 13-13 in FIG.
[0015]
In the following description, front / rear and left / right refer to the hull H to which the outboard motor O is attached.
[0016]
In FIG. 1 to FIG. 3, the outboard motor O attached to the rear end of the hull H is connected to the mount case 1, the extension case 2 connected to the lower end surface of the mount case 1, and the lower end surface of the extension case 2. The V-type 6-cylinder water-cooled four-stroke engine E is mounted on the upper end surface of the mount case 1 with the crankshaft 4 placed vertically.
[0017]
An annular under cover 14 is fixed to the mount case 1 via a stay 13. The under cover 14 covers the periphery of the section from the lower part of the engine E to the upper part of the extension case 2, and an engine hood 12 that covers the engine E from above is detachably attached to the upper end thereof. The engine hood 12 and the under cover 14 define an engine room 15 that houses the engine E.
[0018]
The engine E has a crankcase 5 that supports the vertically placed crankshaft 4 and a pair of left and right banks 6L and 6R that spread in a V shape from the crankcase 5 to the rear. The lower surface is bolted to the upper mounting surface of the mount case 1.
[0019]
As shown in FIGS. 5 and 6, each bank 6L, 6R includes a plurality (three in the illustrated example) of cylinder bores 7L, 7R arranged vertically. The left and right banks 6L and 6R are bolted to the rear end surface of the crankcase 25, and the cylinder block 7 having the left and right cylinder bores 7L and 7R, and the left and right sides of the cylinder block 7 where the cylinder bores 7L and 7R are opened. A pair of cylinder heads 9L, 9R coupled to the rear end surfaces by bolts, and a pair of head covers 10L coupled to the rear end surfaces of the cylinder heads 9L, 9R to close the valve operating chambers formed in the cylinder heads 9L, 9R. 10R.
[0020]
2 to 4, an air intake 16 is provided at the upper rear surface of the engine hood 12, and a flat ventilation duct 17 that communicates with the air intake 16 and opens the lower end to the lower portion of the engine room 15 is an engine hood. 12 is disposed along the inner surface of the rear wall. The air taken into the engine room 15 by the ventilation duct 17 is taken into the left and right banks 6L and 6R through the intake silencer 18 and the intake manifold Mi.
[0021]
The intake silencer 18 is attached to the upper surface of the engine E, has a box shape, and includes a pair of left and right inlets 20 and 20 and an outlet 21 disposed between the inlets 20 and 20. An upstream end of the intake passage 22 a of the throttle body 22 is connected to the outlet 21. A throttle valve 23 that is linked to an accelerator lever (not shown) provided on the hull H is pivotally supported on the intake passage 22a.
[0022]
5 to 7, the intake manifold Mi connected to the downstream end of the intake passage 22a of the throttle body 22 is disposed facing the valley 24 between the left and right banks 6L, 6R. The valley 24 is connected to a plurality of left intake pipes 26L connected to a plurality of intake ports 25L of the cylinder head 9L of the left bank 6L and a plurality of intake ports 25R formed in the cylinder head 9R of the right bank 6R. A plurality of right intake pipes 26R are arranged with their upstream ends directed rearward. A left connecting flange 27L that interconnects the left intake pipes 26L is integrally formed at the upstream ends of the plurality of left intake pipes 26L, and a right connection flange 27R that connects them mutually at the upstream ends of the plurality of right intake pipes 26R. Are integrally formed. Electromagnetic fuel injection valves 28L and 28R for injecting fuel toward the intake valves of the corresponding banks 6L and 6R are attached to the intake pipes 26L and 26R of the left and right banks 6L and 6R.
[0023]
The intake manifold Mi includes an intake distribution box 30 that is long in the vertical direction and flat in the front-rear direction, and is arranged so as to straddle the rear surfaces of both heads of the left and right banks 6L and 6R. A connection flange 32 having an intake inlet 31 at the center is formed on the upper portion of the front wall of the intake distribution box 30, and a connection flange 33 formed at the downstream end of the throttle body 22 is coupled to the connection flange 32.
[0024]
A partition wall 35 extending in the vertical direction is provided in the intake distribution box 30, whereby the interior of the intake distribution box 30 is partitioned into a left distribution chamber 37 </ b> L and a right distribution chamber 37 </ b> R that communicate with the intake inlet 31, respectively. The partition wall 35 is provided with a guide wall 36 for diverting the air flowing into the intake port 31 to the left and right distribution chambers 37L and 37R.
[0025]
A plurality of left intake branch pipes 38L and right intake branch pipes 38R communicating with the left and right distribution chambers 37L and 37R are integrally formed on the front wall facing the valley 24 of the intake distribution box 30. The downstream ends of the left and right intake branch pipes 38L and 38R are integrally formed with one connection flange 39 for connecting them to each other, and this is bolted to the connection flanges 27L and 27R of the left and right intake pipes 26L and 26R. Combined.
[0026]
The partition wall 35 that divides the inside of the intake distribution box 30 into left and right distribution chambers 37L and 37R is provided with a pair of upper and lower valve holes 40 that directly communicate between the distribution chambers 37L and 37R. A pair of butterfly type on-off valves 41 is pivotally supported.
[0027]
Thus, during operation of the engine E, the air flowing into the left and right inlets 20 and 20 of the intake silencer 18 merges in the intake silencer 18, exits the outlet 21, passes through the intake passage 22 a of the throttle body 22, The intake manifold Mi is directed toward the intake inlet 31 of the intake distribution box 30. At that time, in the intake passage 22a, the intake amount of the engine E is controlled by the opening degree of the throttle valve 23.
[0028]
In the low-speed operation region of the engine E, the on-off valve 41 in the intake distribution box 30 is closed, and the air flowing into the intake inlet 31 of the intake manifold Mi flows into the left and right distribution chambers 37L and 37R extending vertically. Divide. The air divided into the left distribution chamber 37L is further divided into a plurality of left intake branch pipes 38L, passes through the left intake pipe 26L, passes through the intake port 25L of the left bank 6L, and is sucked into the corresponding cylinder bore 27L. The air divided into the right distribution chamber 37R is further divided into a plurality of right intake branch pipes 38R, passes through the right intake pipe 26R, passes through the intake port 25R of the right bank 6R, and is sucked into the corresponding cylinder bore 27R.
[0029]
By the way, in the low-speed operation region of the engine E, the left distribution chamber 37L and the right distribution chamber 37R in which the upstream ends of the left and right intake branch pipes 38L and 38R open are closed except for the communication portion with the upper intake inlet 31. The open / close valve 41 shuts off the intake system from the left distribution chamber 37L to the intake port 25L of the left bank 6L and the intake system from the right distribution chamber 37R to the intake port 25R of the right bank 6R. Two resonant supercharging intake systems that do not cause intake interference are configured, and the natural vibration of each resonant supercharging intake system is approximately the opening / closing cycle of the intake valves of the banks 6L and 6R in the low speed operation region of the engine E. Therefore, the resonance supercharging effect is effectively exhibited, the intake charging efficiency in the low speed operation region of the engine is increased, and the output performance can be improved.
[0030]
In the high-speed operation region of the engine E, the on-off valve 41 in the intake distribution box 30 is opened, whereby the left and right distribution chambers 37L and 37R communicate with each other via the valve hole 40 and have a large capacity. Since one surge tank is formed and the upstream ends of the left and right intake branch pipes 38L and 38R are opened in the surge tank, the intake inertia capacity in each of the banks 6L and 6R is increased, and the resonance intake system is substantially reduced. As the length decreases, the natural frequency of the resonant intake system increases to coincide with the opening / closing cycle of the intake valves of the banks 6L and 6R in the high-speed operation region of the engine E, and the resonance supercharging effect is effectively exhibited. As a result, the intake charge efficiency in the high-speed operation region of the engine E increases, and the output performance can be improved.
[0031]
As shown in FIGS. 5 to 8, the intake distribution box 30 includes a distribution box main body 43 made of synthetic resin and a lid body 44 made of high pressure die casting made of a light alloy such as an Al alloy or Mg alloy. The The distribution box main body 43 is formed integrally with the connecting flange 32, the left and right intake branch pipes 38L and 38R, and the half portion 35a of the partition wall 35. The rear wall opposite to the intake branch pipes 38L and 38R has left and right An opening 45 is provided to open over both the distribution chambers 38L and 38R, and the periphery of the opening 45 is an inward joint flange 46. The lid 44 closes the opening 45, and has a loop-shaped surrounding wall 47 surrounding the opening 45 and facing the joining flange 46 on the inner side surface, and the other half 35 b of the partition wall 35. And a plurality of mounting bosses 47 a are formed on the surrounding wall 47. Then, the opening wall 45 is hermetically closed by overlapping the surrounding wall 47 on the joint flange 46 with the seal member 49 interposed therebetween, and connecting the mounting boss 47a to the joint flange 46 with the bolt 51. At that time, the seal member 52 is also interposed between the half portion 35a and the other half portion 35b of the partition wall 35.
[0032]
The pair of upper and lower valve holes 40 and the on-off valve 41 are provided in the other half portion 35b of the partition wall. Each valve hole 40 is formed in a rectangular shape whose long side is directed in the vertical direction, and correspondingly, each on-off valve 41 has a rectangular shape. The pair of upper and lower on-off valves 41 are attached to one common valve shaft 53 extending in the vertical direction. The valve shaft 53 is formed by three coaxially drilled holes from the lower end surface of the lid body 44 to the other half portion 35b of the partition wall. Both end portions and an intermediate portion are rotatably supported by the bearing holes 54a, 54b, 54c.
[0033]
Both valve holes 40 are disposed offset from the center in the longitudinal direction of the partition wall 35 on the lower end side, which is the processing start end side of the bearing holes 54a, 54b, 54c. In this way, the span of the valve shaft 53 can be set to the minimum length necessary only for supporting the on-off valve 41, and a relatively short drill can be used when processing the bearing holes 54a, 54b, 54c. The processing accuracy of each of the bearing holes 54a, 54b, 54c can be easily increased without requiring a high degree of skill. Further, since the machining start ends of the bearing holes 54a, 54b, 54c are located on the side opposite to the intake inlet 31, the bearing holes 54a, 54b, 54c can be easily and highly raised with a relatively short drill regardless of the presence of the intake inlet 31. It can be processed with high accuracy.
[0034]
Thus, the on-off valve 41 is pivotally supported on the other half portion 35b of the partition wall integral with the lid plate 98. Therefore, after the assembly of the lid plate 98 and the on-off valve 41 is assembled, the lid plate 98 is fixed to the intake distribution box 30. By doing so, the intake distribution box 30 with the on-off valve 41 can be assembled efficiently. Further, the loop-shaped enclosure wall 47 on the inner surface of the lid body 44 coupled to the joint flange 46 of the distribution box main body 43 secures the required volume of the intake distribution box 30 and increases the rigidity of the lid body 44 together with the other half portion 35b of the partition wall. It also functions as a reinforcing rib to reinforce, and contributes to reducing the thickness of the lid 44 and thus reducing its weight while preventing warping after molding of the lid 44 and distortion due to the bolt tightening force to the distribution box body 43. be able to.
[0035]
In particular, the lid body 44 having the valve hole 40 is smaller and simpler in shape than the distribution box main body 43 integrated with the suction branch pipes 38L and 38R, so that precision casting such as high-pressure die casting is possible. Therefore, it is possible to easily obtain a high-quality lid body 44 that does not require post-processing of the valve hole 40, has high rigidity, and does not cause distortion even when the ambient temperature changes.
[0036]
Further, since the lid body 44 is effectively reinforced by the surrounding wall body 47, the bearing holes 54a, 54b, 54c formed in the other half portion 35b integral with the lid body 44 are particularly deformed. Therefore, the on-off valve 41 that supports the valve shaft 53 in the bearing holes 54a, 54b, 54c can always be opened and closed smoothly regardless of changes in the ambient temperature. Furthermore, the enclosure wall body 47 on the inner surface of the lid body 44 also serves to expand the runner when the lid body 44 is cast, and improves the castability of the lid body 44, thereby contributing to the improvement of quality.
[0037]
On the outer wall of the lid body 44, an outwardly bulging portion 44a is formed at a portion corresponding to the valve hole 40, and by the formation, an increase in the height of the other half portion 35b of the partition wall is obtained to open the portion. The valve hole 40 having a large area can be formed. Further, the volume of the intake distribution box 30 can be increased by the bulging portion 44a.
[0038]
Further, in order to allow the molding of the valve hole 40, as shown in FIG. 9, the other partition wall half portion 35b is divided into the valve hole 40 along the bearing holes 54a, 54b, 54c. The valve hole 40 is divided into a main body 55 and a partition piece 56, and each valve hole 40 includes a relatively deep notch 40 a formed in the partition wall other half main body 55 and a relatively shallow notch 40 b formed in each partition piece 56. Is done. Both ends of the partition piece 56 are coupled to the partition other half main body 55 by bolts 57 (see FIG. 12).
[0039]
Thus, the notches 40a and 40b can be easily molded when the partition wall other half main body 55 and the partition piece 56 are cast. Can be improved. Further, a plurality of valve holes 40 are provided, and both end portions and intermediate portions of the valve shaft 53 common to the plurality of on-off valves 41 for opening and closing the valve holes 40 are supported by a plurality of bearing holes 54a, 54b, 54c in the other partition half portion 35b. As a result, the valve shaft 53 can be prevented from being bent while the overall opening area of the valve hole 40 is set large, and a smooth opening / closing operation of the opening / closing valve 41 can be ensured.
[0040]
9, 11 and 13, the lower end portion of the valve shaft 53 protrudes below the lid body 44, and the operating lever 60 is fixed to the lower end portion. The actuating lever 60 includes three arms 60 a, 60 b, 60 c arranged at intervals in the circumferential direction, and the first arm 60 a is a stopper projection 61 formed on the lower end surface of the lid 44. , The fully open position of the on-off valve 41 is defined, and the second arm 60b abuts on a stopper bolt 62 that is adjustably screwed to the stopper protrusion 61, whereby the on-off valve 41 is fully closed. It has come to be specified. A valve spring 63 that biases the opening / closing valve 41 in the opening direction is connected to the operating lever 60.
[0041]
An operating rod 65 of a negative pressure actuator 64 is connected to the third arm 60c. The negative pressure actuator 64 includes a casing 66 supported by a bracket 67 screwed to the lower surface of the lid 44, an interior of the casing 66 is divided into an air chamber 69 and a working chamber 70, and an outer peripheral edge is coupled to the casing 66. An operating rod 65 that is pivotally connected to the third arm 60c through the atmosphere chamber 69 is fixed to the center of the diaphragm 71. The working chamber 70 also houses a return spring 72 that biases the diaphragm 71 in the opening direction of the on-off valve 41.
[0042]
A negative pressure introduction pipe 73 connected to the negative pressure chamber projects from the casing 66 of the negative pressure actuator 64, and a control 76 is interposed in the middle of a negative pressure conduit 75 connecting the negative pressure tank 74. This control 76 is constituted by an electromagnetic valve, and is excited in the low speed operation region of the engine E to make the negative pressure conduit 75 conductive by the control of an electronic control unit (not shown) and demagnetized in the high speed operation region. In addition, the negative pressure chamber of the negative pressure actuator 64 is released to the atmosphere. Accordingly, the negative pressure actuator 64 is operated to close the on-off valve 41 in the low speed operation region of the engine E, and the negative pressure actuator 64 is inactivated in the high speed operation region. It will open with a biasing force.
[0043]
The negative pressure tank 74 is connected to a negative pressure conduit 79 connected to a negative pressure extraction pipe 78 formed at the top of the intake distribution box 30, and the negative pressure is extracted from the negative pressure tank 74 in the middle of the negative pressure conduit 79. A check valve 80 is interposed to prevent negative pressure backflow into the tube 78. Accordingly, the intake negative pressure generated in the intake distribution box 30 during operation of the engine E can be stored in the negative pressure tank 74 through the negative pressure conduit 79 and the check valve 80.
[0044]
As shown in FIGS. 9 and 10, the lid 44 has an annular seal housing 82 adjacent to the outer end of the lowermost bearing hole 22 a and a washer housing adjacent to the outer end of the seal housing 82. 83 is formed. An annular seal member 84 is attached to the seal housing 82. The washer housing 83 accommodates a clip 85 that is locked to the outer periphery of the valve shaft 53 and faces the outer end surface of the seal member 84, and one or a plurality of washers 86 that abut against the clip 85 so as to be able to rotate and slide. Then, a holding plate 87 that prevents the washer 86 from being detached is screwed to the lower surface of the lid 44. The seal member 84 is made of an elastic material such as rubber, and has a pair of seal lips 84a and 84b integrally protruding on the inner peripheral surface thereof and projecting in directions away from each other and in close contact with the outer peripheral surface of the valve shaft 53, A metal reinforcing ring 89 that is press-fitted into the inner peripheral surface of the seal housing 82 is baked on the outer peripheral surface.
[0045]
Thus, even if the intake pulsation, that is, the pressure fluctuation in which the negative pressure and the positive pressure are alternately repeated, occurs in the intake distribution box 30 during the operation of the engine E, the seal lips 84a and 84b of the seal member 84 It is possible to reliably prevent outside air from entering the intake distribution box 30 and the pressure in the intake distribution box 30 from leaking through the lowermost bearing hole 54a. It is possible to avoid leakage of fuel, blow bioile, etc. when blown back.
[0046]
As shown in FIG. 13, the actuator 64 is disposed so as to fit within a projection figure below the intake distribution box 30. At this time, in order to avoid the interference of the actuator 64 with the intake distribution box 30, a recess 90 for receiving the upper portion of the actuator 64 is formed on the lower surface of the intake distribution box 30 as shown in FIGS.
[0047]
Thus, the position of the actuator 64 for driving the opening / closing valve 41 can be freely set around the valve shaft 53 by selecting the coupling position of the operating lever 60 with respect to the valve shaft 53 of the opening / closing valve 41. By simply tilting 64 forward, it can be accommodated within the region of the vertical projection figure of the intake distribution box 30, and therefore the actuator 64 and thereby the engine hood 12 close to the rear face of the head of the intake distribution box 30. Interference with the rear wall can be easily avoided. In addition, since the intake inlet 31 and the actuator 64 are arranged at both upper and lower ends of the intake distribution box 30, interference between them can be avoided and the intake device can be made compact. In addition, by receiving the upper portion of the actuator 64 in the recess 90 on the lower surface of the intake distribution box 30, the relatively large actuator 64 can be installed in a narrow engine room without causing interference with the intake distribution box 30 and the engine hood 12.
[0048]
As mentioned above, although the Example of this invention was explained in full detail, this invention can perform a various design change in the range which does not deviate from the summary.
[0049]
【The invention's effect】
As described above, according to the first feature of the present invention, the intake of the V-type engine for an outboard motor, which is disposed with the crankshaft vertically and the heads of the left and right banks facing rearward and covered with the engine hood. An intake inlet connected to the intake passage of the throttle body is provided at one end in the vertical direction of the intake distribution box that is flat between the heads of the left and right banks and the rear wall of the engine hood and is flat in the front-rear direction. The intake distribution box is partitioned by a partition into left and right distribution chambers that communicate with the intake inlet and extend in the longitudinal direction, and an on-off valve that can communicate and block between the left and right distribution chambers. The left and right intake branch pipes are respectively opened in the left and right distribution chambers and connected to the intake ports of the left and right banks, respectively , so that they are arranged in the intake distribution box. One on the wall Molded into, the intake air-dispensing box, the intake inlet, opposite which has a half portion of the left and right intake branch pipes and the partition wall, an opening over between the left and right dispensing chamber and the left and right intake branch pipes A distribution box main body provided on an outer wall of the light source, and a light metal casting lid having a second half of the partition and removably coupled to the distribution box main body so as to close the opening. The on-off valve is attached to a valve shaft that is rotatably supported by the other half and extends in the vertical direction, and an operating lever is provided at an outer end of the valve shaft that projects to the other end in the vertical direction of the intake distribution box. fixation, and is attached to an actuator for opening and closing the on-off valve by rotating the actuating lever to said other end of said intake air-dispensing box, housed in the area of vertical projected figure of the intake distribution box, the partition The other half of the valve hole along the bearing hole. As split, divided into a partition wall other half principal and the partition piece, since the partition member is bolted to the bulkhead other half mainly by the opening and closing of the on-off valve, respectively corresponding to the low and high speed operation of the engine resonance A supercharged intake system can be configured to demonstrate high output performance over a wide range of operation. Moreover, since the intake distribution box that is flat in the front-rear direction is arranged close to the heads of the left and right banks of the engine, the intake distribution box should be arranged in a narrow space between the engine and the rear side wall of the engine hood. It is possible to improve the space efficiency of the engine room and suppress the increase in the size of the engine hood.
[0050]
Since the lid and the on-off valve constitute a single assembly, the on-off valve and its surroundings can be easily maintained by removing the lid from the distribution box body, improving maintenance. Can contribute.
[0051]
Moreover, since the lid made of light alloy casting is smaller and simpler in shape than the distribution box body integrated with the suction branch pipe, precision casting such as high-pressure die casting becomes possible. Therefore, it is easy to obtain a high-quality lid that does not require post-processing of the valve hole, is highly rigid, and does not cause distortion even when the ambient temperature changes. Can be ensured at all times regardless of changes in ambient temperature.
[0052]
Furthermore, the position of the actuator that opens and closes the on-off valve can be set freely around the valve shaft by selecting the coupling position of the operating lever with respect to the valve shaft of the on-off valve. It is easy to fit in the area of the figure, and therefore interference between the actuator and the rear wall of the engine hood adjacent to the rear surface of the intake distribution box can be easily avoided. In addition, since the intake inlet and the actuator are arranged at both upper and lower ends of the intake distribution box, interference between them can be avoided and the intake device can be made compact.
[0053]
Furthermore, the other half part of the partition wall is divided into the main part of the other half part of the partition wall and the partition piece so that the valve hole is divided along the bearing hole. , Half of the valve holes can be easily molded. After casting, troublesome valve hole processing is not required, and productivity can be improved.
[0054]
According to the second feature of the present invention, in addition to the first feature , a recess is formed in a lower end surface of the intake distribution box, and the actuator is disposed obliquely forward so that the actuator is received in the recess. Therefore, a relatively large actuator can be installed in a narrow engine room without interfering with the intake distribution box or the engine hood.
[Brief description of the drawings]
FIG. 1 is an overall side view of an outboard motor according to an embodiment of the present invention.
FIG. 2 is a longitudinal sectional view of a main part of FIG.
3 is a cross-sectional view taken along line 3-3 in FIG.
4 is a cross-sectional view taken along line 4-4 of FIG.
5 is a cross-sectional view taken along line 5-5 in FIG.
6 is a cross-sectional view taken along line 6-6 in FIG.
7 is a cross-sectional view taken along line 7-7 in FIG.
FIG. 8 is an exploded view of the main part of the intake manifold corresponding to FIG. 5;
9 is a cross-sectional view taken along line 9-9 in FIG.
10 is an enlarged view of a portion 10 in FIG. 9. FIG.
11 is a view taken in the direction of arrow 11 in FIG. 8;
12 is a sectional view taken along line 12-12 of FIG.
13 is a cross-sectional view taken along line 13-13 in FIG.
[Explanation of symbols]
E ... Engine O ... Outboard motor 4 ... Crankshafts 6L, 6R ... Left and right banks 22 ... Throttle body 22a ... Intake passages 25L, 25R .. Left and right intake ports 30... Intake distribution box 31... Intake inlet 35... Partition wall 35 a ... partition wall half part 35 b ... partition other half parts 37 L and 37 R. Distribution chambers 38L, 38R ... Left and right intake branch pipes 40 ... Valve hole 41 ... Open / close valve 43 ... Distribution box main body 44 ... Cover body 45 ... Opening 53・ ・ ・ ・ Valve shaft 55 ・ ・ ・ ・ Partition other half main part 56 ・ ・ ・ ・ Partition piece 60 ・ ・ ・ ・ Operating lever 64 ・ ・ ・ ・ Actuator 90 ・ ・ ・ ・ Concavity

Claims (2)

A V-type engine intake system for an outboard motor that is arranged with the crankshaft (4) vertically and the heads of the left and right banks (6L, 6R) facing rearward and covered with an engine hood (12). ,
A throttle body (22) is disposed at one end in the vertical direction of an intake distribution box (30) that is flat in the front-rear direction and disposed between the heads of the left and right banks (6L, 6R) and the rear wall of the engine hood (12). An intake inlet (31) connected to the intake passage (22a) is provided, and left and right distributions extending in the vertical direction are communicated with the intake inlet (31) by partition walls (35) in the intake distribution box (30). The chamber (37L, 37R) is partitioned, and the partition wall (35) is connected to the left and right distribution chambers (37L, 37R) with a valve hole (40) and an open / close valve (41 ) for opening and closing the valve hole (40). Left and right intake branch pipes (38L, 38R) respectively open to the left and right distribution chambers (37L, 37R) and connected to the intake ports (25L, 25R) of the left and right banks (6L, 6R). the, these are before Molded integrally with the front wall of the intake distribution box (30) so as to be disposed in an intake dispensing box (30), said intake air-dispensing box (30), the intake inlet (31), the intake of the right and left A branch pipe (38L, 38R) and a half (35a) of the partition wall (35) are provided, and an opening (45) extending between the left and right distribution chambers (37L, 37R) is provided in the left and right intake branch pipes (38L). , 38R) and a distribution box main body (43) provided on the outer wall opposite to the partition wall (35), and the other half (35b) of the partition wall (35), so as to close the opening (45). A light metal cast lid (44) removably coupled to the main body (43), and rotatably supported by the other half (35b) and extending vertically to the valve shaft (53). An on-off valve (41) is attached, and the intake distribution box (3 ) Is fixed to the outer end protruding to the other end in the vertical direction, and the actuator (64) for opening and closing the on-off valve (41) by rotating the operation lever (60) is provided for the actuator (64). Attached to the other end side of the intake distribution box (30) and accommodated in the region of the vertically projected figure of the intake distribution box (30), the other half (35b) of the partition wall (25) is placed in the bearing hole (54a, 54b, 54c) so as to divide the valve hole (40) along the partition wall other half main body (55) and the partition wall piece (56), and the partition wall other half main body (55) An air intake system for a V-type engine for an outboard motor, characterized in that a bulkhead piece (56) is bolted to the outer side. The V-type engine intake system for an outboard motor according to claim 1,
A multi-cylinder characterized in that a recess (90) is formed in a lower end surface of the intake distribution box (30), and the actuator (64) is disposed obliquely forward so as to be received in the recess (90). Engine intake system.

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