JP2017132433A - Vibration damping structure for outboard engine - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide a vibration damping structure for an outboard engine that can effectively address water immersion and the like, secure and maintain proper operation constantly.SOLUTION: An axial gap between a drive shaft housing and a swivel bracket is formed in a space defined by upper and lower mounts. An atmosphere communication hole 44 for communicating the space to the atmosphere is formed in a front part of the lower mount 22B.SELECTED DRAWING: Figure 4

Description

  The present invention relates to an anti-vibration structure for an outboard motor including a steering force adjusting mechanism capable of adjusting a steering force for steering the outboard motor.

  An outboard motor attached to the stern portion of a propulsion device for a small vessel has an engine mounted on the upper portion of the drive shaft housing of the propulsion unit and is discharged into the water from the lower portion of the propulsion unit of the engine. The propulsion unit is rotatably supported by brackets (swivel brackets) attached to the hull side via mounts (vibration isolation members) at two locations on the upper and lower sides.

  For example, in the outboard motor according to Patent Document 1 or Patent Document 2, a space is formed in which the upper and lower portions between the drive shaft housing and the swivel bracket are closed by two upper and lower mount members.

JP 2002-347696 A JP-A-11-20791

  In the case of the outboard motor of Patent Document 1, it is normally sealed by the sliding contact portion of the mount member. However, the air in the space repeatedly expands and contracts due to the temperature change of the drive shaft housing, and the surrounding air may enter due to the inflow and outflow of the internal air. Further, since the lower mount member is formed of an elastic body, the sliding contact surface with the drive shaft housing is deformed by the propulsion force of the propeller, and there is a case where moisture enters due to a gap.

  In view of such circumstances, an object of the present invention is to provide an anti-vibration structure for an outboard motor that can effectively cope with moisture intrusion and the like and can always ensure and maintain proper operation.

  The vibration isolation structure for an outboard motor according to the present invention has an exhaust passage inside a drive shaft housing formed in a cylindrical shape, and the drive shaft is disposed in a vertical direction. The outer periphery of the cylindrical portion of the drive shaft housing is In an outboard motor having a swivel bracket that is supported at two upper and lower positions via an annular mount, and wherein the drive shaft housing is rotatably supported by the swivel bracket, a radial direction between the drive shaft housing and the swivel bracket A gap is formed in a space defined by the upper and lower mounts, and an air communication hole that connects the space to the atmosphere is formed in a front portion of the lower mount.

  In the vibration isolation structure for an outboard motor according to the present invention, the air communication hole is a passage formed in a groove shape on an outer peripheral surface of the lower mount.

  In the vibration isolation structure for an outboard motor according to the present invention, the air communication hole is formed at a front portion in a left-right direction that avoids a front-rear direction center line of the outboard motor.

  According to the present invention, water or the like entering the space between the upper and lower mounts constituting the vibration isolation structure can be quickly discharged to the outside of the space, and a smooth and appropriate steering function is ensured and maintained over a long period of time. can do.

1 is a side view showing an overall configuration of an outboard motor according to the present invention. It is sectional drawing which shows the internal structure of the outboard motor in this embodiment of this invention. It is sectional drawing which shows the internal structure around the mid unit in this embodiment of this invention. It is an upper perspective view of the mount concerning this embodiment of the present invention. It is a top view of the mount concerning this embodiment of the present invention. It is sectional drawing which follows the II line | wire of FIG. It is a downward perspective view of the mount concerning this embodiment of the present invention. It is a bottom view of the mount concerning this embodiment of the present invention.

Hereinafter, preferred embodiments of an anti-vibration structure for an outboard motor according to the present invention will be described with reference to the drawings.
FIG. 1 is a left side view illustrating a schematic configuration example of an outboard motor 10 as an application example of the present invention, and FIG. 2 is a cross-sectional view illustrating the inside of the outboard motor 10. In this example, the outboard motor 10 is fixed to the rear plate 2 of the hull 1 on the front side as shown in the figure. The outboard motor 10 is equipped with an engine 11, and in the following description, the front of the outboard motor 10 or the engine 11 is indicated by an arrow Fr and the rear is indicated by an arrow Rr as necessary. The right side of 10 is indicated by an arrow R, and the left side is indicated by an arrow L.

  In the overall configuration of the outboard motor 10, an upper unit (or power unit) 12, a mid unit 13, and a lower unit 14 are sequentially arranged from the upper part to the lower part with reference to FIGS. 1 and 2. The engine 11 is mounted on the upper unit 12, and is mounted and supported vertically so that the crankshaft 15 (crankshaft) faces the vertical direction. As the engine 11, a single cylinder engine can be typically employed. The outboard motor main body including the upper unit 12, the mid unit 13 and the lower unit 14 is horizontally arranged by upper and lower rotation support portions 17 (an upper rotation support portion 17A is shown in FIG. 2) provided on the swivel bracket 16. It is rotatably supported. A specific configuration of the rotation support portion 17 will be described later. A pair of clamp brackets 18 (stern brackets) are provided on both the left and right sides of the swivel bracket 16, and both are connected via a tilt shaft 19 set in the left-right direction. The clamp bracket 18 is fixed to the rear plate 2 positioned at the rear end of the hull 1, and the entire outboard motor 10 is supported via the swivel bracket 16 so as to be rotatable around the tilt shaft 19 in the vertical direction.

  In the support structure of the outboard motor main body, referring to FIG. 3, the swivel bracket 16 includes upper and lower rotation support portions 17A and 17B. A handle bracket 21 to which a tiller handle 20 (FIG. 1) is coupled is rotatably attached to the rotation support portion 17A on the upper part of the swivel bracket 16. The handle bracket 21 is generally formed in a cylindrical shape, supports the base portion of the tiller handle 20, and is configured to correspond to the rotation support portion 17A. A mount 22A formed of an elastic body is inserted inside the handle bracket 21, and a drive shaft housing 23 is fitted further inside the mount 22A. An exhaust passage through which exhaust gas from the engine 11 flows is formed in the drive shaft housing 23. The handle bracket 21 and the drive shaft housing 23 are integrally coupled to each other via a mount 22A. The drive shaft housing 23 is rotatably supported by the rotation support portion 17A via the handle bracket 21 and the mount 22A. The engine 11 is mounted and supported on the drive shaft housing 23, and the entire power unit including the drive shaft housing 23 can be horizontally rotated on the rotation support portion 17 </ b> A by rotating the tiller handle 20. Since the mount 22A is inserted between the handle bracket 21 coupled to the tiller handle 20 and the drive shaft housing 23 on which the engine 11 is mounted, it is structured to reduce the vibration of the engine 11 from being transmitted to the tiller handle 20. Yes.

  Further, in the vicinity of the lower portion of the mid unit 13, a lower rotation support portion 17B is provided spaced apart from the upper rotation support portion 17A by a predetermined distance downward. The drive shaft housing 23 is also supported by the rotation support portion 17B so as to be horizontally rotatable. In this case, a mount 22B formed of an elastic body is inserted into the lower end portion of the swivel bracket 16, and thus the drive shaft housing 23 is inserted into the upper and lower end portions of the swivel bracket 16 via the mount 22A and the mount 22B. It has the support structure which elastically supports.

  The drive shaft housing 23 generally has a hollow cylindrical shape, on which the engine 11 is integrally coupled. A drive shaft 24 connected to the lower end portion of the crankshaft 15 is vertically disposed in the drive shaft housing 23, and the driving force of the drive shaft 24 is transmitted to the propeller shaft in the gear case 25 of the lower unit 14. It has become so. A propeller 26 is attached to the rear end of the propeller shaft, and the power of the engine 11 is finally transmitted to the propeller 26 through a power transmission path composed of the crankshaft 15, the drive shaft 24, the propeller shaft, and the like. Can be driven.

  In the above case, the upper unit 12 is covered with the exterior cover 27. The exterior cover 27 includes an upper cover 27A that covers the upper part of the upper unit 12 and a lower cover 27B that covers the lower part of the upper unit 12, and these are integrally joined together to form, for example, a generally egg-shaped or lemon-shaped outer form. Form.

  Here, when the engine 11 is outlined, the engine 11 may be, for example, an OHV (Over Head Valve) engine or the like, and on the drive shaft housing 23 such that the crankshaft 15 of the upper unit 12 faces the vertical direction as shown in FIG. Mounted and supported vertically. The engine 11 includes a cylinder block 29, a cylinder head 30, and a cylinder head cover 31 integrally connected to a rear portion of the engine case 28 sequentially. When the outboard motor 10 is mounted on the hull 1 as shown in FIG. 1, typically, the cylinder axis Z is directed rearward in a horizontal direction perpendicular to the vertical direction.

  The engine case 28 is divided into an upper engine case 28A and a lower engine case 28B each integrally provided with a cylinder block 29. Although not shown in detail, the crankshaft 15 is rotatably supported in the crank chamber 32 by bearing portions provided in the upper engine case 28A and the lower engine case 28B, as shown in FIG. A piston 33 is accommodated in a cylinder bore formed in the cylinder block 29 so as to be capable of reciprocating along the cylinder axial direction. The crankshaft 15 and the piston 33 are connected to each other via a connecting rod. As the piston 33 reciprocates in the cylinder axial direction within the cylinder bore of the cylinder block 29, the crankshaft 15 is driven to rotate via the connecting rod.

  The engine 11 further includes an intake system that supplies a mixture of air (intake air) and fuel, an exhaust system that exhausts exhaust gas after combustion in the cylinder from the engine 11, a cooling system that cools the engine 11, and the engine 11 A lubrication system that lubricates the movable parts and a control system (ECU; Engine Control Unit) that controls the operation thereof are included. A plurality of functional systems cooperate with the above-described auxiliary machines and the like by the control of the control system, whereby the engine 11 as a whole is smoothly operated.

  By appropriately rotating the tiller handle 20 in the outboard motor 10 having the above-described configuration, the outboard motor main body including the engine 11 and the drive shaft housing 23 are connected to the upper and lower rotation support portions 17A and 17 via the handle bracket 21. It rotates with the rotation support part 17B. The power unit can be horizontally rotated on the rotation support portion 17A and the rotation support portion 17B by the turning operation of the tiller handle 20, that is, steering, and the propeller 26 can be steered to a desired angle.

  Further, referring to FIG. 3, the drive shaft housing 23 is supported by the swivel bracket 16 so as to be slidable and rotatable, and a steering force adjusting mechanism 34 for adjusting a steering force for slidingly rotating the drive shaft housing 23 is provided. In the specific configuration of the steering force adjusting mechanism 34, at least the upper rotation support portion 17A has an adjusting operation portion 36 having a screw hole 35 penetrating the swivel bracket 16. A screw shaft 37 whose tip is in contact with a pressing member, which will be described later, is screwed into the screw hole 35 of the adjustment operation unit 36, that is, screwed. A pressing surface 38 is set on the outer periphery of the handle bracket 21 corresponding to the adjustment operation unit 36, and a pressing member 39 is attached between the pressing surface 38 and the tip of the screw shaft 37.

  The pressing surface 38 of the handle bracket 21 is formed in the small-diameter step portion 40 having a smaller diameter than the portion corresponding to the upper rotation support portion 17A. The small diameter step portion 40 is configured by concentrically reducing the lower end portion of the handle bracket 21, and the outer peripheral surface thereof is formed as a pressing surface 38. An operation knob 41 is coupled to the proximal end side of the screw shaft 37 so as to rotate integrally. When the operation knob 41 is rotated to the left or right, the screw shaft 37 advances and retreats in the axial direction. The strength of pressure contact is adjusted. In the above case, as shown in FIG. 4, an annular or short cylindrical resin bushing 42 of the swivel bracket 16 and the handle bracket 21 is mounted on the upper rotation support portion 17 </ b> A. In actual use, the bushing 42 is charged with a lubricant such as grease or an appropriate lubricating oil.

  The pressing surface 38 is provided on the small-diameter step portion 40 at the lower end portion of the handle bracket 21 as described above. In this case, as shown in FIG. 3, the pressing surface 38 is provided to extend downward from the handle bracket 21 so as to be positioned between the upper rotation support portion 17A and the lower rotation support portion 17B.

  In actual use of the outboard motor 10, the outboard motor main body is rotated through the upper and lower rotation support portions 17 </ b> A and 17 </ b> B by the rotation operation of the passenger's tiller handle 20, and the propeller 26 is rotated to a desired angle. You can steer. At this time, the pressing member 39 at the tip of the screw shaft 37 presses the pressing surface 38 appropriately to make sliding contact, and an appropriate steering force of the tiller handle 20 is obtained. Thus, when the outboard motor 10 is steered, the drive shaft housing 23, specifically, the handle bracket 21 is supported by the swivel bracket 16 so as to be slidable and rotatable. It is configured to be screwed into the hole 35 and press the pressing surface 38 of the handle bracket 21 by the pressing member 39 to increase the frictional force of the contact surface, thereby increasing the steering force with respect to the drive shaft housing 23, that is, the operation knob. The desired steering force can be set by rotating operation 41.

  In the outboard motor 10 according to the present invention, referring to FIG. 3, a radial gap between the drive shaft housing 23 and the swivel bracket 16 is formed by a space 43 defined by the upper and lower mounts 22A and 22B. . As shown in FIGS. 4 and 5, an atmospheric communication hole 44 that communicates the space 43 with the atmosphere is formed in the front portion of the lower mount 22 </ b> B.

More specifically, a plurality of atmospheric communication holes 44 are formed in the front-rear direction of the outboard motor 10, that is, in the left-right front portion avoiding the center line M in the traveling direction F. In this example, four atmospheric communication holes 44 are arranged with respect to the center line M, two each on the left and right by center distribution. A projecting portion 22a for defining a position in the rotational direction with respect to the swivel bracket 16 protrudes from the lower portion of the mount 22B.
Further, in the present embodiment, each air communication hole 44 penetrates the mount 22B in the vertical direction as shown in FIG.

  As shown in FIGS. 7 and 8, each air communication hole 44 opens at the lower surface of the mount 22B. That is, the lower surface of the mount 22B has two openings 44a on the left and right by center distribution with respect to the center line M as in the upper surface. It is formed. In this case, each opening 44 a is disposed in a recess 45 formed by recessing the lower surface of the mount 22. The recess 45 reaches the outer peripheral edge of the lower surface of the mount 22B, and a gap is formed by the recess 45 between the step portion 23a of the drive shaft housing 23 where the lower surface of the mount 22B is elastically contacted and the lower surface of the mount 22B as shown in FIG. Is done. Thereby, the space 43 between the mount 22 </ b> A and the mount 22 </ b> B communicates with the atmosphere via the atmosphere communication hole 44 and the recess 45.

  In the vibration isolation structure for an outboard motor according to the present invention, according to the basic operation, the mount 22A is inserted between the handle bracket 21 and the drive shaft housing 23, and the vibration of the engine 11 is transmitted to the tiller handle 20. Can be reduced.

  Particularly in the present invention, the space 43 between the mount 22 </ b> A and the mount 22 </ b> B constituting the vibration isolating structure communicates with the atmosphere through the atmosphere communication hole 44 and the recess 45. The water (or seawater) that has entered the space 43 can be quickly discharged to the outside of the space 43, and salt, waste, etc. contained in the water accumulate in the space 43 and the mount 22A and the mount 22B. It is possible to effectively prevent the operability of the sliding portion from being affected. Therefore, a smooth and appropriate steering function and the like can be secured and maintained over a long period of time. In addition, the outboard motor 10 is at the lowest position in a state in which the outboard motor 10 is tilted up (typically, an angle of 90 ° or less at which the drive shaft 24 is substantially horizontal), and is connected to the front of the lower mount 22B. By positioning the hole 44, drainage can be performed even during storage of the outboard motor 10, and a more reliable drainage effect is realized.

  In the above case, the air communication holes 44 are disposed on the left and right sides of the front portion of the mount 22B, avoiding the center line M in the traveling direction F of the outboard motor 10. The mount 22B receives the thrust of the outboard motor 10 when the hull 1 moves forward, and particularly the portion that overlaps the center line M in the traveling direction F of the outboard motor 10 receives the largest load. Since the air communication hole 44 is disposed avoiding such a portion where a large load is applied, it is difficult to be subjected to deformation due to the load and the like, and an appropriate drainage function can be ensured.

  Next, in a modification of the present invention, the air communication hole is configured as a passage formed in a groove shape on the outer peripheral surface of the lower mount 22B. As shown by the dotted lines in FIG. 5, the concave groove-like passages 46 are arranged one by one on the left and right sides of the center of the traveling direction F in the front part of the mount 22 </ b> B. The Each concave groove-like passage 46 penetrates the outer peripheral surface of the mount 22B in the vertical direction.

  According to the concave groove-like passage 46, as in the case of the air communication hole 44, water (or seawater) that has entered the space 43 can be quickly discharged to the outside of the space 43, and the outboard motor 10 is tilted. It becomes possible to drain more reliably at the lowest position in the up state.

As mentioned above, although this invention was demonstrated with various embodiment, this invention is not limited only to these embodiment, A change etc. are possible within the scope of the present invention.
For example, in the above-described embodiment, the numbers of the air communication holes 44 and the concave groove-like passages 46 can be appropriately increased or decreased as necessary.
In the above embodiment, an example of an OHV engine has been described as the engine 11, but other types such as an OHC engine may be used.

10 outboard motor, 11 engine, 12 upper unit, 13 mid unit, 14 lower unit, 15 crankshaft, 16 swivel bracket, 17A upper rotation support, 17B lower rotation support, 18 clamp bracket, 19 tilt shaft, 20 Tiller handle, 21 Handle bracket, 22 Mount, 23 Drive shaft housing, 23a Step, 24 Drive shaft, 25 Gear case, 26 Propeller, 27 Exterior cover, 28 Engine case, 29 Cylinder block, 30 Cylinder head, 31 Cylinder head cover , 32 Crank chamber, 33 Piston, 34 Steering force adjustment mechanism, 35 Screw hole, 36 Adjustment operation part, 37 Screw shaft, 38 Press surface, 39 Press member, 40 Small diameter step part, 41 Operation knob, 2 bushes space, 43 space, 44 air communication hole 45 recess 46 recess groove-like passage.

Claims (3)

Inside the drive shaft housing formed in a cylindrical shape, an exhaust passage is provided and the drive shaft is arranged vertically, and the outer periphery of the cylindrical portion of the drive shaft housing is supported at two upper and lower positions via annular mounts. In an outboard motor comprising a swivel bracket, and the drive shaft housing is rotatably supported by the swivel bracket.
A radial clearance between the drive shaft housing and the swivel bracket is formed in a space defined by the upper and lower mounts,
An anti-vibration structure for an outboard motor, wherein an atmospheric communication hole for communicating the space with the atmosphere is formed in a front portion of the lower mount.   2. The vibration isolation structure for an outboard motor according to claim 1, wherein the air communication hole is a passage formed in a groove shape on an outer peripheral surface of the lower mount.   The vibration isolation structure for an outboard motor according to claim 1, wherein the air communication hole is formed at a front portion in a left-right direction avoiding a front-rear direction center line of the outboard motor.

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