JPH0435524Y2 - - Google Patents

Description

[Detailed explanation of the idea] (Industrial application field) The present invention relates to a lubrication device for a vertical shaft type engine.

(Prior art and its problems) As shown in FIGS. 10 and 11, a conventional lubricating device uses oil that extends vertically on the inner circumferential surface of a bearing boss 6 that supports the lower output side portion of the crankshaft 3. A passage (vertical groove) 50 is formed, the lower end of the passage 50 is opened to a lubricating oil reservoir, and the upper end of the passage 50 is communicated with the upper end surface of the boss part (thrust receiving part E) which receives the thrust pressure of the crank gear 14. are doing.
The oil level of the lubricating oil L is generally kept below the crank gear 14 in order to prevent excessive oil scattering by the crank gear 14 and the cam gear. That is, oil scattered by a splasher or the like is stored in the oil passage 50 to lubricate the thrust receiving portion E and the like.

However, the device shown in Figure 10 is not designed to forcibly supply lubricating oil, so
Lubrication performance is low and lubrication is insufficient. Particularly in the thrust receiving part E, the friction between the crank gear 14 and the upper surface of the boss part is large, which causes a decrease in engine output.

As a countermeasure to this problem, it is possible to provide ball bearings, but this is insufficient for the thrust load.
Furthermore, when a thrust bearing is used, it is insufficient for the radial load and the cost increases. Incidentally, there is Utility Model Application Publication No. 56-103613 as a prior example.

(Means for Solving the Problems) In order to solve the above problems, the present invention forms an oil passage in the bearing boss portion that supports the lower output side portion of the crankshaft, and the rotation of the crankshaft causes the rotation of the crankshaft to form an oil passage in the oil passage. A pump with variable volume is provided, the lower part of the oil passage faces the lubricating oil reservoir through the oil inlet passage of the crankshaft, and the upper part of the oil passage is connected to the lubricated part through the oil outlet passage of the crankshaft. The pump is placed in the suction stroke within the rotational angle range of the crankshaft when the pressure in the crank chamber is positive, and the lower part of the oil passage is communicated with the lubricating oil reservoir via the oil inlet passage, while the upper part of the oil passage is closed, and when the pressure in the crank chamber is negative. In the rotation angle range of the crankshaft, the pump is set to the compression stroke, and the oil outlet passage is communicated with the upper part of the oil passage, and at the same time, the lower part of the oil passage is closed.

(Example 1) In FIG. 1, a cover crankcase 2 is fixed to the lower side of a crankcase 1, and a generally vertical crankshaft 3 is disposed in a crank chamber 4, and the upper part of the crankshaft 3 is shaped like a ball. It is supported by the crankcase 1 via a bearing 5, and the lower output side portion is supported by the boss portion 6 of the cover crankcase 2. The upper end of the crankshaft 3 protrudes upward and is integrally provided with a flywheel 7.
A cooling fan 11 is provided. The lower part of the crankshaft 3 protrudes downward as an output section.
A crank gear 14 is fixed to the lower side of the lower crank arm portion 3a of the crankshaft 3, and the lower surface of the crank gear 14 is supported in contact with the upper surface E of the boss portion 6.

A cylinder 8 is integrally formed in the crankcase 1, a cylinder head 9 is fixed to the end surface of the cylinder 8, and a cylinder head cover 10 is fixed to the end surface of the cylinder head 9.
A piston 12 is fitted into the cylinder 8, and the piston 12 is connected to the crankshaft 3 via a connecting rod 13.
It is interlocked and connected to the crank pin 19 of. The cylinder head 9 supports intake and exhaust valves 16 and has a rocker arm chamber 17 formed therein.
20 is a fan case that covers the cooling fan 11; 21;
is a breather chamber communicating with the rocker arm chamber 17.

The boss portion 6 has an oil passage 25 extending vertically.
An oil outlet passage 2 is formed in the crankshaft 3 at a position corresponding to the upper end of the oil passage 25.
6 is formed, and an oil inlet passage 29 is formed at a position corresponding to the lower end of the oil passage 25.

The oil outlet passage 26 is formed radially at right angles to the crankshaft 3 and extends from the outer peripheral edge of the crankshaft 3 to the center line of the crankshaft 3. The oil outlet passage 26 can be opened and closed from the oil passage 25 , and the end of the oil outlet passage 26 on the crankshaft center side communicates with a passage 30 in the crankshaft 3 .
The passage 30 in the crankshaft 3 extends upward, communicates with the thrust receiving part E on the upper end surface of the boss part 6 via a radial communication passage 27, and further extends upward to communicate with the inside of the crank arm 3a and the crank pin 19. It passes through the inside and reaches the ball bearing 5 portion, and communicates with an oil supply passage 37 on the upper wall of the cylinder. The oil supply passage 37 reaches the rocker arm chamber 17.
A lower end portion of the rocker arm chamber 17 communicates with the crank chamber 4 via a check valve 35 and a return passage 38. As shown in FIG. 3, radial lubricating grooves 28 are formed in the thrust receiving portion E. As shown in FIG.

The oil inlet passage 29 in FIG. 1 has a U-shaped cross section, and its upper opening can be opened and closed with respect to the lower end of the oil passage 25 by rotation of the crankshaft 3. It can be opened and closed with respect to the oil L in the oil reservoir.

The oil outlet passage 26 communicates with the upper end of the oil passage 25 as shown in FIG. 4a during the compression stroke of the plunger pump 31, which will be described later, and communicates with the upper end of the oil passage 25 as shown in FIG. 4b during the suction stroke of the pump 31.
It is formed in the crankshaft angle range that closes the upper end of the crankshaft.

On the other hand, during the compression stroke of the pump 31, the oil inlet passage 29 closes the lower end of the oil passage 25 to the oil reservoir (oil L) as shown in FIGS. 6a and 7a, and during the suction stroke of the pump 31, As shown in FIG. 7b, the lower end of the oil passage 25 is formed in a position that opens to the oil reservoir.

A pump chamber 33 is formed in the middle of the oil passage 25 in FIG.
It is biased toward the crankshaft 3 by a coil spring 32 compressed within the crankshaft 3, and is brought into contact with a cam 35 of the crankshaft 3. The center of the cam 35 is eccentric from the center of the crankshaft, and the plunger is reciprocated by rotation of the crankshaft, causing the pump 31 to undergo a compression stroke and a suction (expansion) stroke.

(Example 2) FIG. 8 is an explanatory diagram showing another example. In other words, the pressure inside the crank chamber 4 in FIG. 1 fluctuates at the cycle shown in FIG. 8 with respect to the crankshaft angle due to the movement of the piston 12, but the maximum negative pressure value between point B and point C is Crankshaft angle range N around Mn
At this point, the oil outlet passage 26 is open and the pump 31 is in the compression stroke. Also, A in Figure 8
In the crankshaft angle range P near the maximum positive pressure value Mp between point B and point B, the oil inlet passage 29
is opened, and the pump 31 is configured to enter the suction stroke. The other configurations are the same as in Example-1.

(Function) During engine operation, when the pump 31 is in the suction stroke as shown in FIG. 2, the lower end of the oil passage 25 opens to the oil reservoir via the oil inlet passage 29, and the upper end of the oil passage 25 closes. ing. Further, in Example-2, the inside of the crank chamber 4 is under positive pressure. Therefore, the lubricating oil L is efficiently filled into the oil passage 25 by the suction action of the pump 31 and the pushing action by the positive pressure of the crank chamber 4. Next, when the pump 31 enters the compression stroke as shown in FIG. It's pressure. Therefore, the oil in the oil passage 25 is discharged from the oil passage 25 by the discharge action of the pump 31 and the suction action by the negative pressure in the crank chamber 4, and a part of the oil is discharged from the oil passage 25 onto the crankshaft 3.
The thrust receiving portion E on the upper surface of the boss portion 6 is supplied from the passage 27 therein. The thrust receiving part E lubricates the part E and raises the crank gear 14, thereby improving lubrication performance, preventing wear, and preventing a decrease in engine output. Further, a portion of the oil discharged from the oil passage 25 also enters between the boss portion 6 and the crankshaft 3 and lubricates the inner circumferential surface of the boss portion 6.

The remaining lubricating oil in the crankshaft internal passage 30 is
It lubricates the crank pin 19, etc., reaches the upper ball bearing 5, and then enters the rocker arm chamber 17 through the passage 37, where it lubricates the valve arm driving portion, etc. The oil accumulated in the lower part of the rocker arm chamber 17 returns to the crank chamber 4 through the check valve 35 and the return passage 38 when the crank chamber 4 is under negative pressure.

(Another embodiment) The cam 35 for driving the plunger pump is
As shown in the figure, a spacer 3 is placed between the lower surface of the crank gear 14 and the boss portion 6 of the cover crankcase 2.
6 can also be provided on this spacer 36. The spacer 36 rotates integrally with the crank gear 14. Also, the cam 35 is attached to the crank gear 14.
can also be provided directly.

(Effects of the invention) As explained above, the invention forms an oil passage in the bearing boss that supports the lower output side portion of the crankshaft, and provides a pump inside the oil passage whose volume changes with the rotation of the crankshaft. , the lower part of the oil passage faces the lubricating oil reservoir through the oil inlet passage of the crankshaft, and the upper part of the oil passage is connected to the lubricated part through the oil outlet passage of the crankshaft,
During the suction stroke of the pump, or when the pump is on the suction stroke and the pressure inside the crank chamber is positive, the lower part of the oil passage is communicated with the lubricating oil reservoir via the oil inlet passage, and at the same time the upper part of the oil passage is closed, and during the compression stroke of the pump, or Since the pump is configured to communicate with the upper part of the oil passage while simultaneously closing the lower part of the oil passage when the pump is in the compression stroke and the pressure in the crank chamber is negative, there are the following advantages. That is: (1) Since the crankshaft 3 and the bearing boss portion 6 constitute a check valve for suction and discharge, operation is reliable and failures are rare. It also functions reliably even at high speeds. Therefore, highly reliable lubrication is possible and is also advantageous in terms of maintenance.

(2) When the pressure inside the crank chamber 4 is positive, the lower end of the oil passage is opened and the upper end is closed at the same time, and the pump 31
Since this is the suction stroke, oil can be sucked into the oil passage 25 by the pushing action of positive pressure in addition to the suction action of the pump 31. Therefore, even if the output of the pump 31 is small, sufficient oil can be sucked in, so that the output of the crankshaft 3 is not wasted too much to drive the pump, and the pump suction is prevented from decreasing in engine output. Performance is improved.

(3) When the pressure inside the crank chamber 4 is negative, the lower end of the oil passage is closed and the upper end is opened at the same time, and the pump is in the compression stroke. pump 3
In addition to the discharge action of 1, oil can be discharged from the oil passage 25 by a suction action due to negative pressure. Therefore, even if the output of the pump 31 is small, sufficient discharge can be achieved, thereby preventing a decrease in the engine output and increasing the output of the pump 31.
The discharge action is improved.

(4) Items (2) and (3) above also improve the lubrication performance of each lubricated part.

(5) Since the performance of the pump 31 is improved by utilizing pressure fluctuations within the crank chamber 4, the pump 31 can be made smaller, thereby reducing costs.

[Brief explanation of drawings]

Fig. 1 is a vertical sectional view of a vertical shaft type engine to which the present invention is applied, Fig. 2 is a partial longitudinal sectional view showing the state when the crank chamber is under positive pressure, and Fig. 3 is an enlarged cross-sectional view of Fig. 1. Figures 4a, 5a, 6a, and 7a are enlarged cross-sectional views of Figure 1 showing the state when the crank chamber is under negative pressure, and Figures 4b, 5b, 6b, and 7b. The figures below show the conditions when the crank chamber is under positive pressure.
-, -, - An enlarged cross-sectional view, Fig. 8 is a graph showing the relationship between the crankshaft angle and the pressure in the crank chamber, Fig. 9 is a partial vertical sectional view showing another embodiment,
FIG. 10 is a vertical cross-sectional partial view of the conventional example, and FIG. 11 is a cross-sectional view taken from FIG. 10. 3...Crankshaft, 4...Crank chamber, 6...Boss part, 25...
...Oil passage, 26...Oil outlet passage, 29...
...Oil inlet passage, 31...Plunger pump, E...Thrust receiver (an example of a lubricating part).

Claims (1)

[Scope of utility model registration request] In a vertical shaft type engine in which the crankshaft is arranged in a generally vertical position, an oil passage is formed in the bearing boss that supports the lower output side portion of the crankshaft, and a pump whose volume changes with the rotation of the crankshaft is installed in the oil passage. The lower part of the oil passage faces the lubricating oil reservoir through the crankshaft oil inlet passage, and the upper part of the oil passage is connected to the lubricated part through the crankshaft oil outlet passage. The pump is placed in the suction stroke within the rotational angle range of the crankshaft, and the lower part of the oil passage is communicated with the lubricating oil reservoir via the oil inlet passage, and at the same time the upper part of the oil passage is closed. A lubricating device for a vertical shaft engine, characterized in that the pump is in a compression stroke within an angular range, and the oil outlet passage is communicated with the upper part of the oil passage, while at the same time the lower part of the oil passage is closed.