JPS63192918A - Engine equipped with balancer - Google Patents

Abstract

PURPOSE:To miniaturize an engine by installing balancers outside an engine case and supporting the balancers by a part of the engine case and to miniaturize the whole equipment by forming an obtuse-angled wall surrounding the balancers, etc. and installing engine accessories, etc. in a space around the wall. CONSTITUTION:In a two-cylinder four-cycle engine 20 serving as an outboard motor, the driving gear 41 of a balancer equipment 40 is mounted to the upper shaft part 24b of a crankshaft 24, and gear parts 42c of two balancers 42, 42 placed in positions whose phases are shifted by about 180 deg. from each other around the driving gear 41, are engaged with the driving gear 41. The installation direction around the crankshaft 24 of each balancer 42 is inclined by a specified angle theta in the longitudinal direction of the engine 20. The lower parts of shafts 42b of respective balancer gears 42 are pivoted by a balancer case 43 installed adjacent to an engine case 21, an obtuse-angled wall W is formed in a section surrounded by the balancer case 43 and the engine case 21, etc., and a starter 50 is installed in a space S1 around the obtuse-angled wall W.

Description

DETAILED DESCRIPTION OF THE INVENTION (Field of Industrial Application) The present invention relates to an engine equipped with a balancer.

(Problems to be solved by the prior art and the invention) Inertial force is generated in the engine due to the reciprocating movement of the piston, etc.
It is known that vibrations and the like occur in the engine due to the inertial force. Therefore, the crankshaft is provided with a crank web in order to cancel out this inertial force caused by the piston and the like and to prevent vibrations of the engine. However, the crank web generates a new inertia force in a direction perpendicular to the direction of piston movement, causing another vibration cause, so it rotates in the opposite direction at the same speed as the crankshaft to counteract the extra inertia force of the crank web. A new balancer device will be required. That is, this balancer device cooperates with the crank web in the six directions of movement of the piston to cancel the inertial force of the piston, and also attempts to cancel the inertial force of the crank nib in the direction perpendicular to the movement of the piston.

As the above balancer device, the Utility Model Publication No. 52-32802
As shown in the above publication, a pair of balancers is generally installed on both sides of the crankshaft in the radial direction via gears, etc. However, since the balancers stick tightly to both sides of the crankshaft, the balancer Depending on the arrangement, the engine etc. may become larger, making it difficult to attach other engine accessories to the engine area.

The present invention has been made to solve the above-mentioned problems, and its purpose is to attach a balancer to a predetermined position on a crankshaft, and to attach engine components and engine auxiliary equipment to the engine and the balancer device. The objective is to secure an effective installation space for the engine and to make the entire device including the engine and its auxiliary equipment small and compact.

(Means for Solving the Problems) A means for solving the above problems is to provide a pair of engine balancers on both sides of the crankshaft in the radial direction, and to arrange the balancers formed by the balancers and the crankshaft. An obtuse-angled wall is formed on the outer wall surrounding the balancer and the engine so that the installation direction is oblique to the cylinder axis direction of the engine, and engine components or engine auxiliary equipment are placed in the space around the obtuse-angled wall. This means that the

(Function) Since the cylinder axis direction of the engine and the balancer arrangement direction intersect diagonally, the width of the device including the engine and balancer can be kept small, and this also allows the width of the device that surrounds the balancer and engine to be reduced. Since an obtuse-angled wall is formed on the outer wall and engine components or engine auxiliary equipment are arranged in the space around the obtuse-angled wall, the entire device equipped with the engine, balancer, etc. can be made small and compact. can.

The two balancers may be located on the same plane, or may be displaced from each other in the longitudinal direction of the crankshaft.

(Embodiment) A preferred embodiment of the present invention will be described in the attached first embodiment using an outboard motor as an example.
This will be explained in detail with reference to FIGS. 6 to 6.

Figure 1 shows the overall view of an outboard motor installed on a small boat, and (2) shows the clamp member (2a) attached to the stern of the boat.
It is a stern bracket that is attached via a support shaft (3a), and pivotally supports a swivel bracket (3) via a support shaft (3a). An intermediate portion of a support arm (5) is supported on the head (4a) of a swivel shaft (4) rotatably supported in the swivel bracket (3), and the support arm (5)
An outboard motor main body (1) is supported at one end of the support arm (5) via an engine mount (6), and an operating handle (7) is attached to the other end of the support arm (5).

The external appearance of the outboard motor body (1) includes an engine cover (8),
Oil case (9) that supports the engine (20) and auxiliary equipment
), and a lower case (10) below which a propeller (11) etc. are attached, and each case (9),
(10) are connected together with bolts etc., and
The upper part of the lower case (10) is supported from both sides by extension mounds (12a) of an arm member (12) extending from the swivel shaft (4), and
) prevents side touching, etc.

Figure 2 shows the engine (
It shows the configuration of the engine (20) and auxiliary equipment.
is a two-cylinder, four-stroke type with a crankshaft (24) supported vertically, and its main external appearance consists of upper and lower cylinder parts (21a), (21a) formed inside, and pistons (22), (22). ), connecting rod (2
3).

(23), an engine case (21) having a crankshaft (24), etc., and a camshaft (28), a rocker shaft (2
7), an engine head (25) having intake and exhaust valves (28), and so on. In addition, the engine case (21) is connected to the cylinder part (21) on the front side of the engine (20).
a), (21a) and the cylinder part (21a),
(21a) Wider and rear crankcase part (2l)
b”).

The crankshaft (24) has a central crank portion (
24a) and upper and lower shaft parts (24b) and (24C) that partially protrude from the engine case (21). Four counteracting crank webs (24a-1), . . . (balance weights) are attached. Furthermore, two pistons (22),
Since (22) always moves in the same direction, the four crank webs (Ha-1), ... also move in the same direction to cancel the inertial force generated by the pistons (22), (22), etc. It happens.

The lower shaft portion (24c) of the crankshaft (24) of the engine (20) is connected to the propulsion device (11) via a rotation transmission means (not shown), and the upper shaft portion (24b)
A camshaft drive pulley (29) and a flywheel (30) are attached to the recoil starter (20) which manually starts the engine (20) via a starter pulley (31) supported by the flywheel (30).
32) are connected.

Now, the balancer device (40) includes a drive gear (41), balancer gears (42), (42), and a balancer case (4
3), case cover (44), etc., and includes the upper part of the engine case (21) and the camshaft drive pulley (
The drive gear (29) of this balancer device (40) is connected to the upper shaft portion (24b) of the crankshaft (24) between the
41) is attached to the drive gear (41), and as shown in FIG. 3, two balancers (42), (4
2) are meshed through their gear portions (42c) and (42c). The direction in which the balancers (42) and (42) are arranged around the crankshaft (24) is at a predetermined obtuse angle ( It is tilted by θ).

Here, the balancer (42) includes the gear part (42c) formed on its radial outer periphery, the weight part (42a) which is thick on one side in the radial direction, and the crankshaft (2).
4), etc., and the gear diameter of the gear portion (42c) is equal to that of the drive gear (41), so the crankshaft (24
) rotates in the opposite direction at the same speed as
are arranged in the same direction relative to the rotation of the crankshaft (24).

Further, the balancer (42) is pivotally supported by a balancer case (43) formed by projecting the lower part of the balancer shaft (42b) from the engine case (21), and the upper part of the balancer shaft (42b) is supported by the balancer case (43). ) is pivotally supported by the case cover (44). The case cover (44) supports the cover (32a) of the recoil starter (32).

Here, the functions of the crank webs (24a-1), . . . and the balancer device (40) will be described. The four crank webs (24a-1), . The parts (42a) and (42a) each have a quarter of the inertia force due to the reciprocating mass, and the crank web (24a-1), . . . and the balancer weight part (42a).

(42a) means the piston (22), the top of (22),
Since the directions are configured to match at the bottom dead center, the inertial force generated by the reciprocating motion of the pistons (22) and (22) is transferred to the crank web (24a-1),
... and the balancer device (40), the crank web (24a-1), ..., and the balancer weight part (42a).

The inertia force in the direction perpendicular to the moving direction of the pistons (22) and (22) due to the pistons (42a) is also zero because their rotational directions are opposite, and the vibrations of the engine (20) are effectively suppressed.

Note that the balancer device (40) and crank web (24a-1
),...Which surface of inertia force acts on is the crankshaft (2
Since the crankshaft (4) is divided into upper and lower parts, the crankshaft (
24) acts on a couple that tries to rotate the crankshaft (24) up and down, and this couple acts on the oil case (24).
The outboard motor main body (1) is supported by the swivel bracket (3) above and below the engine mount (6) and extension mount (12a). Therefore, the force couple is absorbed and canceled by these mounts (8) and (12a).

Now, since the balancer case (43) and the like of the balancer device (40) are arranged above the engine case (21) and separately from the engine (20), the width of the engine (20) itself can be reduced and the engine ( 20) can be made smaller, and
Since the balancer case (43) and the like are disposed diagonally across the engine (20), the width of the outboard motor body (1) in which they are disposed can be kept as small as possible. The portions of the balancer case (43) etc. that protrude toward the rear side of the engine, that is, the crankcase portion (21b) of the engine case (21), and the cylinder portion (21a) of the engine case (21) are shown in FIG. As shown, since they intersect at an obtuse angle (θ), an obtuse-angled wall portion (W) is formed in a portion surrounded by the engine case (21), balancer case (43), etc.;
), a wide space (Sl) is formed above and below along the crankshaft (24).

In addition, the front side of the engine such as the balancer case (43) protrudes from the engine case (21), and the engine case (43) protrudes from the engine case (21).
21) and the balancer case (43) form a recess ff), so that a long front-rear space is formed in the front-rear direction of the engine (20) as shown in FIGS. 4 and 5 along the engine case (21). (Sl) is formed.

In the wide space (Sl), engine parts or engine accessories can be conveniently arranged in close contact with the engine (20), and in this embodiment, as shown in FIGS. 4 to 6, A starter (50) for automatic engine start is provided. The starter (50) has main body support parts (51), (51) attached to the engine case (21) with bolts, etc., and the upper drive gear (52) of the starter (50) is attached to the flywheel (30). The engine (20a) meshes with the ring gear (30a) attached to the
), and if the starter (50) is not required, the drive gear (52) moves below the ring gear (30a) as shown in FIG. 4 so that they do not interfere with each other.

Since the flywheel (30) is located above the balancer device (40), its meshing position with the drive gear (52) of the starter (50) is convenient.

That is, the drive gear (52) of the starter (50) moves up and down, so the ring gear (30) of the flywheel (30)
It is preferable that point (a) be located at the upper position, and since the starter (50) is attached to the upper part of the engine case (21), the drive gear (52) is naturally located at the upper position. Further, the palancer device (40) is connected to the crank web (24a-1) of the crankshaft (24),
...The closer one is, the crank shirt 1- (24)
This is preferable because the vertical couple generated in the above can be suppressed to a small value.

Also, the front and rear space (Sl) below the parenser device (40)
Engine parts or engine auxiliary equipment are also included in the engine (20
), but in this embodiment, the long space before and after the carburetor (6
0) etc. are arranged as shown in FIGS. 3 to 5. The carburetor (60) is attached to the engine head (25) via an intake manifold (61), and an air inlet pipe (62) is attached to the upstream side of the carburetor (60), so that the entire structure is long and parallel to the engine. It is set up.

In this case, the intake manifold (61) improves the mixing of the fuel oil and air mixture, and the two cylinder parts (
In order to evenly distribute the mixture to 21a) and (21a), it is preferable that the pipe be long to some extent, and the air inflow pipe (62) is also suitable for improving the rectifying effect of the air entering the carburetor (60). It is better to have a certain length. Therefore, this longitudinal space (Sl), which is long in the longitudinal direction along the engine (2o), is most effectively utilized in this case. In addition, by disposing a carburetor (60) etc. in this front and rear space (Sl), the outboard motor body (1)
can be made small and compact.

In addition, the balancer (42) of the balancer device (40), (
42) are arranged substantially on the same plane across the crankshaft (24) in this embodiment for an outboard motor, but in a general crankshaft vertical support type engine, one side is placed on the upper shaft of the crankshaft. Even if the other part is shifted to the lower shaft part and disposed outside the engine case, the wide space and the front and rear spaces as described above are sufficiently secured, and the equipment surrounding the engine can be made sufficiently compact. In this case, since the balancer is disposed so as to sandwich the crank web vertically, there is no force couple that would cause the crankshaft to rotate up and down due to the inertial force of the crank web and balancer. Furthermore, in this embodiment, a two-stroke, four-cycle engine in which the crankshaft is supported vertically was explained as an example, but the engine is not limited to this, and an engine in which the crankshaft is supported horizontally may also be used. The number may change.

Furthermore, in this embodiment, balancers (42), (42)
Even if the engine is housed in the engine case (21), a wide upper and lower space (Sl) can still be secured. However, in this case, if the two balancers (42) and (42) are arranged on the same plane, the front and rear space (Sl) will be divided vertically and become smaller. ) side balancer (42) must be shifted toward the outer end of the crankshaft (21) from the engine case (21).

(Effects of the Invention) As is clear from the above, according to the present invention, since the engine balancer is disposed obliquely with respect to the longitudinal direction of the engine,
The width of the entire device on which the engine, balancer device, etc. are mounted can be reduced, and the device can be made smaller.

In addition, since the longitudinal direction of the engine and the direction in which the balancer is disposed obliquely intersect, an obtuse-angled wall can be formed on the outer wall surrounding the balancer and the engine, and the space around the obtuse-angled wall can be Engine components or engine accessories can be disposed in close contact with the engine, and the entire device including the engine can be made small and compact.

In addition, a balancer is disposed at the outer end of the crankshaft outward from the engine case, and an engine starter is disposed in the space around the obtuse-angled wall, and the flywheel of the engine is driven by the starter. Since the engine and balancer are separated, the engine can be made smaller, and the space around the obtuse-angled wall can be used effectively, making the engine more compact. Furthermore, since the flywheel is provided closer to the outer end of the crankshaft than the balancer installation surface of the crankshaft, single power transmission between the starter and the flywheel, which are relatively long vertically, is achieved.
Additionally, the starter can be easily attached to the engine or the like.

[Brief explanation of the drawing]

Fig. 1 is a diagram showing the entire outboard motor, Fig. 2 is a cross-sectional side view of the engine and its surroundings, Fig. 3 is a cross-sectional view of the balancer device, etc., and Fig. 4 is a plan cross-sectional view of the engine and carburetor. , FIG. 5 is a diagram showing how the balancer, starter, carburetor, etc. are installed, and FIG. 6 is a side view of FIG. 5. In the drawing, (20) is the engine, (21) is the engine case, (24) is the crankshaft, (30) is the flywheel, (40) is the balancer device, (42) is the balancer gear, (50) is the starter, (Sl) is a wide space;
(W) is an obtuse-angled wall portion.

Claims (2)

[Claims] (1) A pair of engine balancers are arranged around the crankshaft with their phases shifted by approximately 180 degrees, and the direction of arrangement of the balancers around the crankshaft is oriented obliquely with respect to the cylinder axis direction of the engine, An engine equipped with a balancer, characterized in that an obtuse-angled wall is formed on an outer wall surrounding the balancer and the engine, and engine components or engine auxiliary equipment are disposed in a space around the obtuse-angled wall. (2) The balancer is located on the outer end of the crankshaft outside the engine case, and a flywheel is attached to the crankshaft located further on the outer end side of the balancer installation surface, and the flywheel is driven. 2. The engine equipped with a balancer according to claim 1, wherein an engine starting device is disposed in a space around the obtuse angle wall.