JP3777315B2 - Variable intake system for multi-cylinder engines - Google Patents

Description

[0001]
BACKGROUND OF THE INVENTION
  According to the present invention, an intake inlet connected to the intake passage of the throttle body is provided in the intake distribution box, and the inside of the intake distribution box is partitioned by a partition into first and second distribution chambers respectively communicating with the intake inlet. First and second intake branch pipes that open to the first and second distribution chambers and connect to the intake ports of the first and second banks of the engine, respectively, are connected to the intake distribution box, and the first and second intake pipes are connected to the partition wall. A valve hole communicating between the second distribution chambers and a butterfly type on-off valve for opening and closing the valve hole are provided, and the intake characteristics are changed by opening and closing the on-off valve according to the operating state of the engine, thereby reducing the engine speed. The present invention relates to a variable intake system for a multi-cylinder engine that can maintain high output performance in a wide operating range from high to low.
[0002]
[Prior art]
  Such a variable intake system for a multi-cylinder engine is already known as disclosed in, for example, Japanese Patent Laid-Open No. 9-88746.
[0003]
[Problems to be solved by the invention]
  By the way, in the air intake device disclosed in the above publication, the air distribution box is divided into a plurality of division surfaces parallel to the wall surface of the partition wall having the valve holes, the partition wall is made independent, and the partition wall casting, injection molding, etc. A valve hole is formed at the same time as molding.
[0004]
  However, depending on the structure of the intake device, there is a case where the intake distribution box is forced to be divided by a plane orthogonal to the wall surface of the partition wall having the valve hole due to the molding thereof. In such a case, the valve hole to the partition wall is required. It becomes difficult to form.
[0005]
  The present invention has been made in view of such circumstances, and even when the intake distribution box is divided by a plane orthogonal to the wall surface of the partition wall having the valve hole, the valve hole can be easily molded. An object of the present invention is to provide a variable intake device for a multi-cylinder engine.
[0006]
[Means for Solving the Problems]
  In order to achieve the above object, the present invention provides:TheInlet inlet connected to the intake path of the Lottle BodyFlat withThe inside of the intake distribution box is partitioned by a partition into first and second distribution chambers that communicate with the intake inlet, respectively.As well asThe first and second intake branch pipes that open to the first and second distribution chambers and connect to the intake ports of the first and second banks of the engine, respectively, are connected to the intake distribution box.Provided inThe variable intake device for a multi-cylinder engine is provided with a valve hole communicating with the first and second distribution chambers and a butterfly type on-off valve for opening and closing the valve hole in the partition wall.The intake inlet, the first and second intake branch pipes, and one half of the partition are integrally formed on a flat front wall on the first and second bank sides, and the rear wall on the opposite side Has a distribution box main body provided with an opening extending between the first and second distribution chambers, and the other half of the partition, and is detachable from the distribution box main body so as to close the opening. The intake distribution box is constituted by a light metal lid to be joined, the lid is made of high pressure die casting, and the valve hole and the valve of the on-off valve that opens and closes the valve hole are formed in the other half of the partition wall. A plurality of bearing holes arranged coaxially to support the shaft are formed, and the other half portion of the partition wall is a divided surface orthogonal to the wall surface of the partition wall, and the partition wall other half main body is bolted to this. The other half of the partition wall is divided into a plurality of bearing holes and a space between the bearing holes. The U-shaped deep notch is formed on the partition wall piece, and the U-shaped shallow notch forming the valve hole is formed in the partition piece together with the deep notch. MissingOn opposite side edgesIsThe distance between the side edges is tapered toward the opening surface.TheIt is characterized by that.
[0007]
  According to this feature,The lid made of light alloy high-pressure die-casting is small and simple in shape as compared with the distribution box main body integrated with the suction branch pipe, so that precision casting is possible. Therefore, it is possible to easily obtain a high-quality lid body that does not require post-processing of the valve hole, has high rigidity, and does not cause distortion even when the ambient temperature changes.
[0008]
  Further, the other half of the partition wall is divided into a partition wall other half main body and a partition wall piece bolted to the partition wall half.TheThe other half of the partition wall is formed mainly with the plurality of bearing holes and a U-shaped deep notch disposed between the bearing holes, while the partition hole is provided with the valve hole together with the deep notch. By forming a shallow U-shaped notch that matches the opening surfaces to each other, the other half main body and the partition pieceHigh pressure die castingAt the time of molding, the notches can be formed at the same time, and the valve holes can be easily configured by aligning their opening surfaces. Also especially deep cutoutsSince the opposite side edges of the taper are tapered such that the distance between the side edges increases toward the opening surface, high pressure die casting is performed.It is easy to release from the notch during molding, and it is possible to obtain a precise valve hole without scratches on the inner surface without performing troublesome valve hole finishing after molding, improving productivity. Can be planned. AlsoBulkhead part with deep and shallow notches(I.e., bulkhead and other half main parts and bulkhead pieces)Therefore, it is possible to reliably prevent the heat distortion of the valve, and thus the deformation of the valve hole, to always ensure an accurate opening / closing function of the opening / closing valve.
[0009]
DETAILED DESCRIPTION OF THE INVENTION
  Embodiments of the present invention will be described below based on one embodiment of the present invention shown in the accompanying drawings.
[0010]
  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. FIG. 13 is a cross-sectional view taken along line 13-13 in FIG. 11, and FIG. 14 is a cross-sectional view showing a method for casting the lid.
[0011]
  In the following description, front / rear and left / right refer to the hull H to which the outboard motor O is attached.
[0012]
  1 to 3, the outboard motor O attached to the rear end of the hull H is coupled to the mount case 1, the extension case 2 coupled 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.
[0013]
  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.
[0014]
  The engine E includes 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.
[0015]
  As shown in FIGS. 5 and 6, each of the banks 6L and 6R includes a plurality (three in the illustrated example) of cylinder bores 7L and 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 banks of the cylinder block 7 where the cylinder bores 7L and 7R are opened. A pair of cylinder heads 9L, 9R bolted to the rear end surfaces, and a pair of head covers 10L, coupled to the rear end surfaces of the cylinder heads 9L, 9R, in order to close the valve chambers formed in the cylinder heads 9L, 9R. 10R.
[0016]
  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.
[0017]
  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.
[0018]
  5-7, 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. Further, in the valley 24, 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 are connected. A plurality of right intake pipes 26R are arranged with their upstream ends directed rearward. At the upstream ends of the plurality of left intake pipes 26L, left connection flanges 27L are integrally formed. The left connection flanges 27R are connected to each other 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.
[0019]
  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 both rear surfaces 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 thereto.
[0020]
  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 inlet 31 to the left and right distribution chambers 37L and 37R.
[0021]
  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. At the downstream ends of the left and right intake branch pipes 38L and 38R, one connecting flange 39 is formed integrally with the left and right intake pipes 26L and 26R. Combined.
[0022]
  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.
[0023]
  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, the intake air amount of the engine E is controlled by the opening degree of the throttle valve 23 in the intake passage 22a.
[0024]
  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 enters the left and right distribution chambers 37L and 37R that extend 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.
[0025]
  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 resonance supercharging intake systems in which no intake interference occurs are configured, and the natural vibration of each resonance supercharging intake system is substantially the same as 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.
[0026]
  Further, in the high-speed operation region of the engine E, the on-off valve 41 in the intake distribution box 30 is opened, so that the left and right distribution chambers 37L and 37R communicate with each other through the valve hole 40 and have a large capacity. Since one surge tank is configured and the upstream ends of the left and right intake branch pipes 38L and 38R are opened in this 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. Thus, the intake charging efficiency in the high-speed operation region of the engine E is increased, and the output performance can be improved.
[0027]
  As shown in FIGS. 5 to 8, the intake distribution box 30 is composed of a distribution box main body 43 made of a synthetic resin and a lid body 44 made of a 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 enclosure 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 enclosure wall 47 is overlapped on the joint flange 46 with the seal member 49 interposed therebetween, and the mounting boss 47a is coupled to the joint flange 46 with a bolt 51, whereby the opening 45 is closed in an airtight manner. At that time, the sealing member 52 is also interposed between the half portion 35a and the other half portion 35b of the partition wall 35.
[0028]
  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 with the long side directed in the vertical direction and rounded at each corner, and correspondingly, each on-off valve 41 has a similar 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, and the valve shaft 53 is formed by three coaxially drilled 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.
[0029]
  Both valve holes 40 are offset from the central portion in the longitudinal direction of the partition wall 35 and are generally offset from 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 opposite side of the intake inlet 31, the bearing holes 54a, 54b, 54c can be easily and highly formed with a relatively short drill regardless of the presence of the intake inlet 31. It can be processed with high accuracy.
[0030]
  In this way, the opening / closing valve 41 is pivotally supported by 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 body 43 increases the rigidity of the lid body 44 together with the other half portion 35b of the partition wall while ensuring the necessary volume of the intake distribution box 30. It also functions as a reinforcing rib to reinforce, and contributes to the thinning of the lid body 44 and its weight reduction while preventing warping after molding of the lid body 44 and distortion due to the bolt tightening force to the distribution box main body 43. be able to.
[0031]
  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 it is possible to perform precision casting such as high-pressure die casting. Therefore, it is possible to easily obtain a high-quality lid 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.
[0032]
  Further, since the lid body 44 is effectively reinforced by the surrounding wall body 47 on the inner surface thereof, 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.
[0033]
  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.
[0034]
  Furthermore, in order to enable the molding of the valve hole 40, as shown in FIG. 9, the partition other half half portion 35b is mainly composed of the partition other half half portion so as to divide the valve hole 40 along a plane perpendicular to the wall surface of the partition wall 35. 55 and the partition piece 56, each valve hole 40 has a U-shaped relatively deep notch 40 a that opens in the partition surface of the partition wall other half main body 55, and U that opens in the partition surface of the partition piece 56. A relatively shallow notch 40b having a letter shape is formed by matching each opening surface. At that time, the opposite side edges of the U-shaped relatively deep notch 40a are provided with a taper θ in which the distance between the side edges increases toward the opening surface. On the other hand, the U-shaped relatively shallow notch 40b is rounded from the opening edge to the bottom surface. Needless to say, the on-off valve 41 is formed in a shape corresponding to the valve hole 40. Both end portions of the partition piece 56 are coupled to the partition other half main body 55 by bolts 57 (see FIG. 12).
[0035]
  As is apparent from FIG. 14, the casting mold 95 of the lid 44 includes a female die 95b and a male die 95a that are divided at the peripheral edge of the lid 44, and the male die 95a is the deep notch 40a. , And the same taper θ as that of the deep notch 40a is attached to both side edges of the projection 97. Thus, when the lids 44 are formed by closing the molds 95a and 95b and pouring the molten metal into the cavity 96 defined between them, the deep notch 40a is formed by the protrusion 97 of the male mold 95a. The After casting, if both molds 95a and 95b are opened, the taper θ attached to each side edge of the deep notch 40a and the protrusion 97 becomes a die-cutting slope, so that the mold release from the deep notch 40a is easy. Since it can be performed, a precise deep notch 40a having no scratch on the inner surface can be obtained. Further, by casting the partition piece 56 in the same manner, the shallow notch 40b can be precisely formed. Therefore, troublesome valve hole machining is not required after casting, and productivity can be improved.
[0036]
  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.
[0037]
  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 body 44. , The fully open position of the on-off valve 41 is defined, and the fully closed position of the on-off valve 41 is established by the second arm 60b abutting on a stopper bolt 62 screwed to the stopper projection 61 in an adjustable manner. 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. Therefore, the opening / closing limit of the on-off valve 41 can be accurately defined without providing the actuator 64 with a stopper means, and the structure of the valve hole 40 can be simplified by integrating the stopper projection 97 with the lid 44. Combined with the simplicity of the formation, it can greatly contribute to cost reduction.
[0038]
  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 atmospheric chamber 69 and an operating 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.
[0039]
  The casing 66 of the negative pressure actuator 64 is provided with a negative pressure introduction pipe 73 connected to the negative pressure chamber, and a control 76 is interposed in the middle of a negative pressure conduit 75 that connects 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 by an electronic control unit (not shown), and demagnetized in the high speed operation region to cause the negative pressure conduit 75 to flow. 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.
[0040]
  The negative pressure tank 74 is connected to a negative pressure conduit 79 connected to a negative pressure take-out pipe 78 formed at the upper portion of the intake distribution box 30, and the negative pressure is taken out 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.
[0041]
  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 84 a and 84 b that protrude in a direction away from each other and are 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.
[0042]
  Thus, during operation of the engine E, even if an intake pulsation, that is, a pressure fluctuation in which negative pressure and positive pressure are alternately repeated, is generated in the intake distribution box 30, 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, and to prevent dust from entering the intake air intake distribution box 30; It is possible to avoid leakage of fuel, blow bioile, etc. during blowback.
[0043]
  As shown in FIG. 13, the actuator 64 is arranged so as to be within a projection figure below the intake distribution box 30. At this time, in order to avoid 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.
[0044]
  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 is possible to fit within the area of the vertical projection graphic of the intake distribution box 30, and therefore the actuator 64 and thereby the rear wall of the engine hood 12 proximate to the rear surface of the intake distribution box 30. 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 apparatus can be made compact. Moreover, by allowing the upper portion of the actuator 64 to be received 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 interfering with the intake distribution box 30 and the engine hood 12.
[0045]
  Although the embodiments of the present invention have been described in detail above, various design changes can be made without departing from the scope of the present invention.The
[0046]
【The invention's effect】
  As described above, the present inventionInAccording toTheInlet inlet connected to the intake path of the Lottle BodyFlat withThe inside of the intake distribution box is partitioned by a partition into first and second distribution chambers that communicate with the intake inlet, respectively.As well asThe first and second intake branch pipes that open to the first and second distribution chambers and connect to the intake ports of the first and second banks of the engine, respectively, are connected to the intake distribution box.Provided inThe variable intake device for a multi-cylinder engine is provided with a valve hole communicating with the first and second distribution chambers and a butterfly type on-off valve for opening and closing the valve hole in the partition wall.The intake inlet, the first and second intake branch pipes, and one half of the partition are integrally formed on a flat front wall on the first and second bank sides, and the rear wall on the opposite side Has a distribution box main body provided with an opening extending between the first and second distribution chambers, and the other half of the partition, and is detachable from the distribution box main body so as to close the opening. The intake distribution box is configured with a light metal lid to be joined, the lid is made of high pressure die casting, the valve hole in the other half of the partition, and the valve shaft of the on-off valve that opens and closes the valve hole A plurality of bearing holes arranged on the same axis to support the partition wall, and the other half portion of the partition wall is divided by a partition surface orthogonal to the wall surface of the partition wall. Since it is divided into bulkhead pieces, the lid made of light alloy casting is a distribution box body that has a suction branch pipe integrally inside Compared since compact and shape is simpler, it is possible to precision casting such as high-pressure die casting. Therefore, it is possible to easily obtain a high-quality lid body that does not require post-processing of the valve hole, has high rigidity, and does not cause distortion even when the ambient temperature changes.
[0047]
  Further, the other half portion of the partition wall is formed with the plurality of bearing holes and a U-shaped deep notch disposed between the bearing holes, while the partition piece includes the deep notch and the deep notch. A U-shaped shallow notch forming the valve hole was formed.Because of the other half main part and the bulkhead pieceHigh pressure die castingEach is available during castingDoBy forming a deep cutout and a shallow cutout at the same time and aligning their opening surfaces, the valve hole can be easily configured. Especially deep cutoutsofOn opposite side edgesIsSince the distance between the side edges is tapered toward the opening surface,High pressure die castingIt is easy to release from the notch during molding, and it is possible to obtain a precise valve hole without scratches on the inner surface without performing troublesome valve hole finishing after molding, improving productivity. Can be planned. AlsoBulkhead part with deep and shallow notches(I.e., bulkhead and other half main parts and bulkhead pieces)Therefore, it is possible to reliably prevent the heat distortion of the valve, and thus the deformation of the valve hole, to always ensure an accurate opening / closing function of the opening / closing valve.
[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.
FIG. 14 is a cross-sectional view showing a lid casting method.
[Explanation of symbols]
E ... Engine
6L, 6R ... 1st and 2nd banks (left and right banks)
22 ... Throttle body
22a: Intake passage
25L, 25R ... 1st and 2nd intake ports (left and right intake ports)
30 ... Intake distribution box
31 .... Intake inlet
35 .. Bulkhead
35a: half of the partition wall
35b ... Partition other half
37L, 37R: First and second distribution chambers (left and right distribution chambers)
38L, 38R ... 1st and 2nd intake branch pipes (left and right intake branch pipes)
40 ... Valve hole
40a ... deep notch
40b ... shallow notch
41... Open / close valve
55... Partition part having a deep notch (partition wall other half main part)
56... Partition part having a shallow notch (partition piece 56)

Claims (1)

The partition wall (35) a flat intake air-dispensing box (30) having slot Le intake path of the body (22) an intake inlet communicating with (22a) (31), first and respectively communicating with the intake inlet (31) In addition to partitioning into the second distribution chamber (37L, 37R), the first and second distribution chambers (37L, 37R) open to the intake air of the first and second banks (6L, 6R) of the engine (E), respectively. First and second intake branch pipes (38L, 38R) respectively connected to the ports (25L, 25R) are provided in the intake distribution box (30) , and the partition wall (35) includes the first and second distribution chambers. A variable intake device for a multi-cylinder engine provided with a valve hole (40) communicating between (37L, 37R) and a butterfly type on-off valve (41) for opening and closing the valve hole (40) ,
One half part (35a) of the intake inlet (31), the first and second intake branch pipes (38L, 38R) and the partition wall (35) is a front wall on the first and second bank (6L, 6R) side. And a partition box main body (43) provided with an opening (45) between the first and second distribution chambers (37L, 37R) on the opposite rear wall, and the partition wall ( 35) a light metal lid (44) having a second half (35b) and removably coupled to the distribution box body (43) so as to close the opening (45); Constituting the intake distribution box (30),
The lid (44) is made of high pressure die casting, and the valve hole (40) and the valve of the on-off valve (41) for opening and closing the valve hole (40) are formed in the other half (35b) of the partition wall (35). A plurality of bearing holes (54a, 54b, 54c) arranged on the same axis to support the shaft (53);
Further, the other half portion (35b) of the partition wall (25) is a partition plane orthogonal to the wall surface of the partition wall (35), and the partition wall other half portion main body (55) and the partition piece (56) to be bolted to this The partition and the other half main part (55) are U-shaped and arranged between the bearing holes (54a, 54b, 54c) and the bearing holes (54a, 54b, 54c). The U-shaped shallow notch (40b) that forms the valve hole (40) together with the deep notch (40a) is formed in the partition wall piece (56). Forming,
The side edges of opposing deep notches of the U-shaped (40a) is characterized in that the distance between the both side edges are subjected taper (theta) that extends toward the opening face, a multi-cylinder engine Variable intake device.

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