JPH0350885B2 - - Google Patents

Description

[Detailed Description of the Invention] [Industrial Application Field] The present invention relates to a two-stroke engine lubrication system suitable for use in outboard motors, etc., and particularly relates to a lubrication system for a two-stroke engine that is suitable for use in outboard motors, etc. The present invention relates to a separate lubrication device that supplies lubricating oil to various parts of an engine.

[Conventional technology]

The present applicant has proposed a lubrication system as the above-mentioned separate lubrication system, which makes it possible to apply an oil pump of the same capacity to two-stroke engines of various specifications, in the patent application filed in 1982-
This is proposed in No. 109976 (Japanese Patent Application Laid-Open No. 59-512). This already proposed lubricating device reciprocates the plunger of the oil pump in the vertical direction by the rotation of the crankshaft, and the pin of the adjustment plate that regulates the lower end position of the plunger is pressed against the adjustment cam by the spring. The pump lever that enables the adjustment cam to be driven and the throttle lever that is connected to the throttle valve shaft are connected by a ring, and the return torque of the throttle valve is smaller than that of the throttle valve, and the discharge amount of the oil pump is increased. A biasing torque is constantly applied to the pump lever, and the throttle lever is connected to the throttle valve shaft so that it can rotate relative to it within a predetermined angle range, and the maximum operating angle of the throttle lever can be adjusted. The minimum oil pump discharge amount is ensured at the initial opening stage, and the oil pump discharge amount is made variable according to subsequent changes in the opening of the throttle valve, and the width of the change in the oil pump discharge amount can be adjusted. It is something to do.

[Problem to be solved by the invention]

In the lubrication device already proposed above, the pump lever and the adjustment cam are integrated, and the pin of the adjustment plate is held at a predetermined upper level on a part of the cam surface of the adjustment cam to maintain the minimum discharge amount. It provides a contour with a constant radius that can be secured. Therefore, during the initial opening stage of the throttle valve, the biasing force of the spring that presses the pin against the adjustment cam remains constant and relatively large, and the frictional force acting between the adjustment cam and the pin also remains constant. At this stage, the drive torque that the pump lever should give to the adjustment cam also needs to be a constant, relatively large value. However, in this lubricating device, the pump lever is not rotated in the direction of increasing the oil pump discharge amount by forced drive from the throttle valve shaft side, but by being forced to act on the pump lever. It is possible to rotate the oil pump in the direction of increasing the discharge amount by applying the biasing torque.
It is difficult to stably apply a large driving torque exceeding a predetermined value to the adjusting cam.

Therefore, the previously proposed lubricating device may not be able to reliably operate the adjusting cam due to the biasing torque acting on the pump lever during the initial opening stage of the throttle valve. There is a possibility that the minimum discharge amount of the oil pump that is required at the initial opening stage of the throttle valve cannot be reliably secured.

The present invention provides a lubrication system that makes it possible to adjust the range of change in oil discharge amount that changes in accordance with changes in the opening degree of the throttle valve, and that makes it possible to apply oil pumps of the same capacity to two-stroke engines of various specifications. It is an object of the present invention to provide a lubricating device that can reliably secure the minimum discharge amount of an oil pump required at the initial opening stage of a valve.

[Means for Solving the Problems] In order to achieve the above object, the present invention provides a lubricating system for a two-stroke engine that has already been proposed by the applicant. It has a mating part, and the engaging part is
At the initial opening stage of the throttle valve, the throttle valve moves idly without engaging the adjusting cam, and after that time, it engages with the adjusting cam and becomes capable of driving the adjusting cam.

[Function] According to the present invention, the pump lever is provided with an idle range at the initial opening stage of the throttle valve. As a result, the adjustment cam holds the pin of the adjustment plate at a predetermined level without being driven by the pump lever during the initial opening stage of the throttle valve.
Stably maintains the minimum oil pump discharge amount required at the initial opening stage of the throttle valve.
Make sure to secure it.

[Example] Hereinafter, an example of the present invention will be described with reference to the drawings.

FIG. 1 is a front view showing a two-stroke three-cylinder engine for an outboard motor to which an embodiment of the present invention is applied;
FIG. 2 is a sectional view showing the oil pump used in the same embodiment, and FIG. 3 is an enlarged view showing the main parts of FIG. 1.

Three cylinders are formed above and below in the cylinder block 11, and a vertical crankshaft 13 is supported between the cylinder block 11 and the crankcase 12. A drive shaft 13A disposed within the unit is connected. A piston 14 is housed in each cylinder, and each piston 14 is connected to the crankshaft 13 via a connecting rod 15. A carburetor 18 is connected to the crank chamber 16 of each cylinder via an intake manifold 17. In addition, 19 in the figure
is an oil tank that stores lubricating oil.

An oil pump 20 is fixed to the front lower part of the cylinder block 11. oil pump 20
As shown in FIG. 2, the oil tank 19 is connected to a suction pipe 21 and a discharge pipe 2 corresponding to each cylinder.
2, and a driven gear 2 that meshes with a drive gear 24 fixed to the crankshaft 13.
5, a ring gear 26 that meshes with the driven gear 25,
A revolving body 28 that forms an oil chamber 27 that communicates intermittently with the suction pipe 21 and the discharge pipe 22, and is integrated with the ring gear 26 and rotatably supported by the housing 23; A plunger 29 is housed and reciprocates up and down within the oil chamber 27, a spring 30 urges the plunger 29 downward, and a spring 30 is fixed to the housing 23 so that the tip of the pin 31 of the plunger 29 can be pushed upward. It has a cam 32 that That is, as the crankshaft 13 rotates, the drive gear 24 and the driven gear 2
5. When the rotating body 28 rotates within the housing 23 through the meshing of the driven gear 25 and the ring gear 26, the plunger 29, which rotates with the rotation of the rotating body 28, is rotated through the contact between its pin 31 and the cam 32. The lubricating oil is sucked in from the oil tank 19 through the suction hose 33 connected to the suction pipe 21 and transferred from each discharge pipe 22 to each discharge hose 34 by moving up and down inside the oil chamber 27. ,3
5, 36, the intake manifold 1 of each cylinder
7 and can be discharged into the air-fuel mixture.

The oil pump 22 also includes an adjustment plate 37 that is inserted into the inner circumference of the ring gear 26 so as to be able to move up and down, and a spring 3 that biases the adjustment plate 37 downward.
8, and an adjustment cam 4 that can regulate the tip of the pin 39 integrated with the adjustment plate 37 to a predetermined level.
0. The adjustment plate 37 has its upper surface abutted against the lower surface of the plunger 29 to regulate the lower end position of the plunger 29, thereby regulating the range of reciprocating movement of the plunger 29, thereby adjusting the slot of the oil pump 20. It is possible to regulate the minimum displacement amount required for the engine at the initial opening stage of the tutle valve and the maximum displacement amount determined according to the engine specifications. Here, an interlocking shaft 41 of a pump lever 42 is connected to the adjustment cam 40 in an interlocking relationship as will be described later, and the pump lever 42 is connected to a throttle valve shaft 44 via a link 43. Throttle lever 4
5 are combined. That is, as the opening degree of the throttle valve increases, the throttle lever 4
5. The pump lever 42 rotates via the link 43, and the adjustment cam 40 is interlocked with the pump lever 42.
When the operating angle θ _B of the oil pump 20 increases, the adjustment plate 37 moves below a predetermined level, and the reciprocating stroke of the plunger 29 increases, causing the oil pump 20
The discharge amount Q can be increased.

Moreover, between the housing 23 of the oil pump 20 and the pump lever 42, the return spring torque T A of the throttle valve interposed between the throttle valve shaft 44 and the carburetor body is smaller than the return spring torque T _A of the throttle valve, and the oil A spring 46 is interposed that can apply a biasing torque T _B to the pump lever 42 in the direction of increasing the discharge amount of the pump 20. In addition, a notch 47 is formed in the connecting portion of the throttle lever 45 to the throttle valve shaft 44, so that the throttle valve shaft 44 and the throttle lever 45 can rotate relative to each other within a predetermined angular range (θ _A2 +α). It is said that In the figure, reference numeral 47A is a pushing surface on which the throttle valve shaft 44 comes into contact and the return spring torque _TA of the throttle valve acts on the throttle lever 45. Further, the carburetor body is provided with an adjustment screw 48 that comes into contact with the side of the throttle lever 45 and allows the maximum operating angle θ _A1 of the throttle lever 45 to be adjusted.

Therefore, the adjustment cam 40 in this embodiment
The interlocking relationship between the pump lever 42 and the interlocking shaft 41 is as shown in FIGS. 4A to 4C and FIG. 5. That is, the interlocking shaft 41 of the pump lever 42 is formed with an engaging portion 41A that engages with the adjustment cam 40 and enables the adjustment cam 40 to be driven. The engaging portion 41A of the interlocking shaft 41 does not engage with the adjusting cam 40 at the initial opening stage of the throttle valve, but engages with the adjusting cam 40 by the subsequent rotation of the interlocking shaft 41. It is possible to drive. FIG. 4A shows the closing stage of the throttle valve, F ₁ shows the relatively large biasing force of the spring 38 pressing the pin 39 against the adjusting cam 40, and FIG. 4B
shows the condition of the throttle valve at the end of the initial opening phase; FIG. _4C shows the condition of the throttle valve after the initial opening phase;
8, which shows a relatively small biasing force.

Note that the adjustment cam 40 includes a return spring (not shown).
The biasing torque Tc is always applied. This biasing torque Tc is smaller than the biasing torque T _B of the spring 46, but larger than the biasing torque of the spring 38 (torque due to F1 to F2). Thereby, when the adjustment cam 40 is not driven by the engaging portion 41A, it is pressed against the original position setting pin 100 by the biasing torque Tc and is automatically set to the original position. The pin position of this original position setting pin 100 may be adjustable.

Next, the operation of the above embodiment will be explained.

When the throttle valve shaft 44 rotates from the closed position to an intermediate opening corresponding to the maximum operating angle θ _A1 of the throttle lever 45, the biasing torque of the spring 46
Due to T _B , the throttle lever 45 rotates to its maximum operating angle θ _A1 , and the pump lever 42 rotates to its maximum operating angle θ _BK .

Here, at the initial opening stage of the throttle valve when the pump lever 42 rotates from its original position to the angle θ _BO shown in FIG. 6, the interlocking shaft 41 of the pump lever 42 is rotated as shown in FIGS. Therefore, the adjusting cam 40 is not driven by the pump lever 42 and rotates through the adjusting plate 37.
pin 39 is held at a predetermined upper level to ensure the minimum oil pump discharge amount Q ₀ shown in FIG.

After the initial opening stage of the throttle valve has passed,
The interlocking shaft 41 of the pump lever 42 rotates together with the adjustment cam 40 as shown in FIG.
is displaced from a predetermined upper level to a lower level. At this time, the biasing force of the spring 38 that presses the pin 39 against the adjustment cam 40 is F1 to _F4 in FIG. 4B.
The pump lever 4 gradually weakens as shown in _F2 in Figure C, and the frictional force acting between the adjusting cam 40 and the pin 39 also gradually decreases.
2 also gradually decreases the driving torque to be applied to the adjusting cam 40, so that the adjusting cam 40 is smoothly driven by the biasing torque of the spring 46 acting on the pump lever 42, and the oil pump discharges. The amount can be surely increased as shown in FIG.

The throttle valve shaft 44 has the intermediate opening degree,
When rotating between the intermediate opening position and the fully open position, which is the sum of the operating angle θ _A2 , the throttle valve shaft 4
4 freely moves inside the notch 47, and the maximum operating angles θ _BK and θ _A1 of the pump lever 42 and the throttle lever 45 are maintained by the biasing torque T _B of the spring 46. That is, the maximum discharge amount of the oil pump 20 is determined by the pump lever 4 as shown in FIG.
Q _K corresponds to the maximum operating angle θ _BK in this case of 2, and by changing the maximum operating angle θ _BK of the pump lever 42 by adjusting the adjusting screw 48, the maximum discharge amount Q of the oil pump 20 can be adjusted. It becomes possible to adjust the upper limit of _K. In addition,
The throttle valve shaft 44 is connected to the throttle lever 4
When the throttle valve is closed from the maximum operating angle θ _A1 of 5 to the fully closed position, the throttle valve return spring torque is
Since T _A acts on the throttle lever 45 from the throttle valve shaft 44 via the pushing surface 47A, the pump lever 42 and the throttle lever 4
5 can be returned to these closed positions by the return spring torque _TA .

Although the above embodiment describes the case where the present invention is applied to a two-stroke engine for an outboard motor, the present invention is applicable to a general two-stroke engine.

[Effects of the Invention] As described above, according to the present invention, it is possible to adjust the range of change in the oil discharge amount that changes according to the change in the opening degree of the throttle valve. It is possible to obtain a lubricating device which can be applied to the oil pump and which can reliably ensure the minimum discharge amount of the oil pump required at the initial opening stage of the throttle valve.

[Brief explanation of drawings]

FIG. 1 is a front view showing a two-stroke three-cylinder engine for an outboard motor to which an embodiment of the present invention is applied;
Fig. 2 is a sectional view showing the oil pump used in the same embodiment, Fig. 3 is an enlarged view showing the main parts of Fig. 1, and Figs. 4 A to C show the discharge amount of the oil pump. Explanatory diagram showing the adjustment state, fifth
The figure is a schematic diagram taken along the - line of FIG. 4A, and FIG. 6 is a diagram showing the discharge characteristics of the same oil pump. 13... crankshaft, 18... carburetor, 20...
...Oil pump, 29...Plunger, 37...
Adjustment plate, 40... Adjustment cam, 42... Pump lever, 43... Link, 44... Throttle valve shaft, 45... Throttle lever, 46... Spring,
T _A : Return torque, T _B : Biasing torque.

Claims (1)

[Claims] 1 The plunger of the oil pump is reciprocated in the vertical direction by the rotation of the crankshaft, and the pin of the adjustment plate that regulates the lower end position of the plunger is pressed against the adjustment cam by the spring, so that the adjustment cam can be driven. The pump lever and the throttle lever connected to the throttle valve shaft are linked together, and a biasing torque that is smaller than the return torque of the throttle valve and that increases the oil pump discharge amount is constantly applied to the pump lever. The throttle lever is interlocked with the throttle valve shaft in the rotation range of the throttle valve from the closed position to the intermediate opening, and the throttle lever is interlocked with the throttle valve shaft in the rotation range of the throttle valve exceeding the above intermediate opening. The throttle lever is connected to the throttle valve shaft so that it moves freely relative to the throttle lever, and the maximum operating angle of the throttle lever can be adjusted, and the setting position of the adjustment plate by the adjustment cam is adjusted to the throttle valve opening By adjusting according to the
The discharge amount of the oil pump is made variable according to subsequent changes in the opening degree of the throttle valve, and the range of change in the discharge amount of the oil pump is adjustable.
In a cycle engine lubricating device, the pump lever has an engaging portion that can drive the adjusting cam, and the engaging portion does not engage the adjusting cam at the initial opening stage of the throttle valve and remains empty. 1. A lubrication device for a two-stroke engine, characterized in that the lubrication device engages with an adjustment cam after the movement and can drive the adjustment cam.