JP4060927B2 - 4-cycle engine intake and lubrication system - Google Patents

Description

[0001]
BACKGROUND OF THE INVENTION
The present invention relates to an intake / lubricating device for a small four-cycle engine using a mixed fuel of oil and gasoline used for a brush cutter, for example.
[0002]
[Prior art]
As is well known, the conventional two-cycle engine uses a mixed fuel of oil and gasoline, and has the advantage that the oil contained in this mixed fuel can be adhered to the cylinder or piston and lubricated, but the exhaust is completely exhausted. Since the mixed gas of the fuel mixture and air is sucked into the cylinder before it is performed, a part of the sucked mixed gas is discharged with incomplete combustion, and harmful substances in the exhaust gas have an adverse effect on the environment. There was a problem of giving.
[0003]
In view of the problems of the two-cycle engine as described above, various small four-cycle engines using a mixed fuel of oil and gasoline have been developed in recent years.
An example of the four-cycle engine is that a mixed gas of oil and gasoline mixed with fuel and air reaches the crank chamber from the carburetor, and the mixed gas in the crank chamber is compressed in the crank chamber when the piston is lowered. The compressed mixed gas flows from the crank chamber to a chamber provided with a valve mechanism that includes a gear, a cam, and the like that drives a rocker arm that opens and closes the intake valve and the exhaust valve. Further, the intake valve and the exhaust valve The mixed gas flowing into the rocker arm chamber that is driven to open and close is configured to be sucked into the cylinder when the intake valve is opened during the intake stroke.
The mixed gas from the carburetor is circulated through the crank chamber, valve mechanism, and rocker arm chamber because the oil contained in the mixed fuel is driven to open and close the cylinder, piston, intake valve and exhaust valve. This is because the gears and cams, which are constituent members of the valve mechanism mechanism, are attached to the rocker arms that open and close the intake valves and the exhaust valves to perform a lubricating action.
[0004]
[Problems to be solved by the invention]
However, the conventional four-cycle engine as described above includes a carburetor, a crank chamber, a valve operating mechanism that opens and closes intake and exhaust valves, a rocker arm chamber that opens and closes intake and exhaust valves, and an intake valve. Due to the long intake passage leading to the large resistance of the flow of the mixed gas, the intake efficiency of the mixed gas into the cylinder is reduced when the intake valve is opened in the intake stroke, which causes a decrease in engine output. It was.
In addition, the oil contained in the mixed gas is attached to the gears, cams, rocker arms, etc. of the valve mechanism that opens and closes the cylinders, pistons, intake valves, and exhaust valves. There was a problem that there was a case.
[0005]
In order to eliminate the above-described problems, the present invention branches from the lower surface of the intake passage from the carburetor to the intake valve of the cylinder head, and the mixed gas containing a large amount of oil on the lower surface of the intake passage is supplied to the intake valve and By providing a passage provided with a check valve that circulates in the central portion of the valve mechanism that opens and closes the exhaust valve, the mixed gas containing a large amount of oil and the oil stored on the lower surface of the intake passage are: The valve mechanism and the crank chamber communicated with the valve mechanism through the passages, and further to the rocker arm chamber for lubrication, the mixed gas from the carburetor directly opens the intake valve. An object of the present invention is to provide an intake and lubrication device for a four-cycle engine that is configured to be supplied to a cylinder sometimes.
[0006]
[Means for Solving the Problems]
In order to achieve the above object, according to the first aspect of the present invention, an intake passage 4 is provided directly from the carburetor 1 to the intake valve 3 of the cylinder head 2, and is branched from the bottom surface 4a of the intake passage 4. A mixed gas containing a large amount of oil has a crank chamber at the center in the vertical direction of the valve operating mechanism 6 that drives the rocker arm 5 that opens and closes the intake valve 3 and the exhaust valve. And rocker arm chamber The outlet to the valve operating mechanism side faces the vertical position range of the push rod of the valve operating mechanism and includes a check valve 7 so as to flow directly without going through the valve. Further, the cylinder head is formed in a straight line with a constant circular cross section from the branch portion with the intake passage to the outlet to the valve operating mechanism side. The intake / lubricating device of the four-cycle engine is characterized in that a passage 8 is provided.
By providing the intake passage 4 from the carburetor 1 to the intake valve 3 in this way, the mixed gas from the carburetor 1 is directly supplied to the intake valve 3 during the intake stroke of the engine. The efficiency of sucking the mixed gas into the cylinder 9 is increased, whereby the output of the engine can be improved.
On the other hand, a rocker arm 5 is branched from the bottom surface 4a of the intake passage 4 from the carburetor 1 to the intake valve 3 with a large opening area, and a mixed gas containing a large amount of oil opens and closes the intake valve 3 and the exhaust valve. By providing the passage 8 provided with the check valve 7 so as to flow to the valve mechanism mechanism 6 that drives the engine, the mixed gas containing a large amount of oil is lifted by the piston during the compression stroke and the exhaust stroke of the engine. Accompanying the negative pressure in the crank chamber and the valve mechanism mechanism chamber, the intake valve 3 and the exhaust valve are opened and closed by the rocker arm 5 and the valve mechanism mechanism 6 that drives the rocker arm 5 are sufficiently sucked. It can adhere to and lubricate.
[0007]
According to the second aspect of the present invention, the intake passage 4 is provided directly from the carburetor 1 to the intake valve 3 of the cylinder head 2 and is branched from the bottom surface 4a of the intake passage 4 to contain a large amount of oil. A crank chamber is provided at the center in the vertical direction of the valve mechanism 6 that drives the rocker arm 5 that opens and closes the intake valve 3 and the exhaust valve. And rocker arm chamber The outlet to the valve operating mechanism side faces the vertical position range of the push rod of the valve operating mechanism and includes a check valve 7 so as to flow directly without going through the valve. Further, the cylinder head is formed in a straight line with a constant circular cross section from the branch portion with the intake passage to the outlet to the valve operating mechanism side. A four-cycle engine characterized in that a passage 8 is provided, and further, a flow passage 12 is provided between the chamber 10 and the crank chamber 11 of the valve mechanism section 6 to allow a mixed gas to flow there between. This is an intake and lubrication system.
As described above, by providing the flow passage 12 between the chamber 10 and the crank chamber 11 of the valve mechanism 6 to allow the mixed gas to flow therethrough, when the piston 13 is lifted, Along with the negative pressure, the mixed gas in the chamber 10 of the valve mechanism 6 is sucked into the crank chamber 11, and the mixed gas in the crank chamber 11 is compressed and flows to the valve mechanism 6 when the piston 13 is lowered. That is, as the piston 13 moves up and down, the mixed gas moves between the valve mechanism 6 and the crank chamber 11, and the oil contained in the mixed gas is applied to the crank pin that rotates in the valve mechanism 6 and the crank chamber 11. It is possible to sufficiently adhere to the connecting portion of the connected connecting rods, and further, the piston and cylinder can be sufficiently lubricated by splashing the oil attached to the connecting portion to the piston and cylinder.
[0008]
Further, the invention described in claim 3 is provided with an intake passage 4 directly from the carburetor 1 to the intake valve 3 of the cylinder head 2 and branched from the bottom surface 4a of the intake passage 4 to contain a large amount of oil. A crank chamber is provided at the center in the vertical direction of a valve mechanism 6 that drives a rocker arm 5 that opens and closes an intake valve 3 and an exhaust valve. And rocker arm chamber So that the outlet to the valve operating mechanism side faces the position range of the push rod of the valve operating mechanism in the vertical direction. Furthermore, the cylinder head is linearly formed in the thick part of the cylinder head from the branching portion with the intake passage to the outlet to the valve operating mechanism side. A passage 8 is provided, a check valve 7 for the passage 8 is provided at an outlet 8a of the passage 8 toward the valve mechanism 6 and a space between the crank chamber 11 and the chamber 10 of the valve mechanism 6 is provided. A flow passage 12 through which the mixed gas flows is provided between the two, the chamber 10 of the valve mechanism 6 serves also as a vent pipe, and the mixed gas is sucked into the chamber 10 and the rocker arm chamber 14 of the valve mechanism 6. The intake and lubrication device for a four-cycle engine is characterized by being configured as described above.
Thus, the chamber 10 of the valve mechanism 6 serves also as a mixed gas ventilation pipe, and the mixed gas containing a large amount of oil flowing into the chamber 10 of the valve mechanism 6 through the passage 8 is Since it is configured to be sucked into the rocker arm chamber 14, the oil contained in the mixed gas can be attached to the intake valve 3, the exhaust valve, the rocker arm 5 that opens and closes the valve, etc., and lubrication can be improved.
[0009]
According to a fourth aspect of the present invention, a flow passage 12 is provided between the crank chamber 11 and the chamber 10 of the valve operating mechanism 6 so that a mixed gas flows between them. The gap between the cam 6b and timing gears 6c and 6c for driving the push rod 6a of the rocker arm 5 for opening and closing the intake valve 3 and the exhaust valve, which are constituent members of the mechanism unit 6, and the chamber 10 of the valve mechanism unit 6 is as follows. The mixed gas flows smoothly, the oil contained in the mixed gas adheres to the cam 6b and the timing gears 6c and 6c, and is set to a narrow gap that can be scraped up by the rotation of the cam 6b and the timing gears 6c and 6c. It is composed.
[0010]
As described above, by providing the flow passage 12 between the chamber 10 and the crank chamber 11 of the valve mechanism 6 to allow the mixed gas to flow therethrough, when the piston 13 is lifted, Along with the negative pressure, the mixed gas in the valve mechanism 6 is sucked into the crank chamber 11, and the mixed gas in the crank chamber 11 is compressed and flows to the valve mechanism 6 when the piston 13 is lowered. That is, as the piston 13 moves up and down, the mixed gas moves between the valve mechanism 6 and the crank chamber 11, and the oil contained in the mixed gas is applied to the crank pin that rotates in the valve mechanism 6 and the crank chamber 11. It is possible to sufficiently adhere to the connecting portion of the connected connecting rods, and further, the oil adhering to the connecting portion jumps to the piston and the cylinder to sufficiently lubricate the piston and the cylinder.
Furthermore, a narrow desired gap is set between the chamber 10 of the valve mechanism 6 and the cam 6b and timing gears 6c, 6c, which are constituent members of the valve mechanism 6, so that the cam 6b and timing gear 6c. , 6c is rotated, the oil accumulated in the narrow gap is swung up by the cam and the timing gear, and the oil is splashed to improve the lubrication of the entire valve mechanism.
[0011]
The invention according to claim 5 is the oil stored in the rocker arm chamber 14 between the upper surface 4 b of the intake passage 4 from the carburetor 1 to the intake valve 3 of the cylinder head 2 and the rocker arm chamber 14. A four-cycle engine intake / lubricating device is provided with a circulation passage 15 through which a mixed gas containing a large amount of gas can be circulated to the intake passage 4.
By providing the circulation passage 15 as described above, a mixed gas containing a large amount of oil stored in the rocker arm chamber 14 is returned to the intake passage 4 through the circulation passage 15, and in the intake stroke of the engine. Then, the gas is sucked into the cylinder together with the mixed gas from the carburetor, and the suction efficiency of the mixed gas can be improved.
According to a sixth aspect of the present invention, the intake passage has a circular cross section and extends horizontally, and the passage has a smaller diameter than the diameter of the intake passage. Because It extends horizontally, and the axial center of the intake passage and the axial center of the passage are in a torsional positional relationship, and the opening of the passage includes the bottom of the intake passage. The four-cycle engine intake / lubricating device is formed on the lower peripheral surface side and has an opening area larger than that when the two shaft centers intersect.
[0012]
DETAILED DESCRIPTION OF THE INVENTION
Hereinafter, each embodiment of the present invention will be described in detail.
FIG. 1 is a side view showing a valve mechanism that opens and closes an intake valve and an exhaust valve provided with an intake / lubricator of a four-cycle engine according to the present invention, and FIG. 2 is a four-cycle engine provided with an intake / lubricator. It is a longitudinal cross-sectional view.
[0013]
In the first aspect of the present invention, as shown in FIGS. 1 to 3, an intake passage 4 extending from the carburetor 1 to the intake valve 3 of the cylinder head 2 is provided, and the opening area is increased from the bottom surface 4 a of the intake passage 4. Therefore, the mixed gas containing a large amount of oil is branched (range of ¼ of the peripheral length of the intake passage 4) and drives the rocker arm 5 that opens and closes the intake valve 3 and the exhaust valve (not shown). A passage 8 including a check valve 7 is provided so as to flow to the valve mechanism 6.
That is, as shown in FIG. 3, one end of the passage 8 is connected to an opening having a wide opening area in the bottom surface 4a of the intake passage 4, and includes a large amount of oil in the mixed gas. A liquid portion (a mixed gas containing a large amount of oil) is likely to flow from one end of the passage 8.
[0014]
Thus, by providing the intake passage 4 directly from the carburetor 1 to the intake valve 3, the mixed gas of the oil-mixed fuel and air from the carburetor 1 is directly supplied to the intake valve 3 during the intake stroke of the engine. Therefore, the intake efficiency of the mixed gas into the cylinder 9 is increased when the intake valve 3 is opened, thereby improving the output of the engine.
[0015]
On the other hand, the rocker arm 5 is branched from the bottom surface 4a of the intake passage 4 extending from the carburetor 1 to the intake valve 3 with a large opening area, and the mixed gas containing a large amount of oil drives the intake valve 3 and the exhaust valve to open and close. By providing the passage 8 provided with the check valve 7 so as to flow to the valve mechanism mechanism 6 that drives the engine, the mixed gas containing a large amount of oil is lifted by the piston during the compression stroke and the exhaust stroke of the engine. Accompanying the negative pressure in the crank chamber and the valve mechanism mechanism chamber, the intake valve 3 and the exhaust valve are opened and closed and the rocker arm 5 that drives the rocker arm 5 and the valve mechanism mechanism 6 that drives the rocker arm 5 are sucked and mixed. The oil contained in the gas is sufficiently adhered to the valve operating mechanism 6 and the lubricating action can be sufficiently performed.
[0016]
According to the second aspect of the present invention, the intake passage 4 extending from the carburetor 1 to the intake valve 3 of the cylinder head 2 is provided, and the opening is enlarged from the bottom surface 4a of the intake passage 4 to branch the oil. A passage 8 provided with a check valve 7 is provided so that the mixed gas containing a large amount flows to the valve mechanism 6 that drives the rocker arm 5 that opens and closes the intake valve 3 and the exhaust valve. Between the chamber 10 of the valve mechanism section 6 and the crank chamber 11, a flow passage 12 through which a mixed gas flows is provided.
[0017]
As described above, by providing the flow passage 12 between the chamber 10 and the crank chamber 11 of the valve mechanism 6 to allow the mixed gas to flow therethrough, when the piston 13 is lifted, Along with the negative pressure, the mixed gas in the valve mechanism 6 is sucked into the crank chamber 11, and the mixed gas in the crank chamber 11 is compressed and flows to the valve mechanism 6 when the piston 13 is lowered. That is, as the piston 13 moves up and down, the mixed gas moves between the valve operating mechanism 6 and the crank chamber 11, and the oil contained in the mixed gas rotates in the valve operating mechanism 6 and the crank chamber 11. The connecting rod 19 can be sufficiently attached to the connecting portion of the connecting rod 19, and the oil attached to the connecting portion can splash the piston 13 and the cylinder 9 to sufficiently lubricate the piston 13 and the cylinder 9.
[0018]
According to the third aspect of the present invention, an intake passage 4 extending from the carburetor 1 to the intake valve 3 of the cylinder head 2 is provided, and an opening area is made large from the bottom surface 4a of the intake passage 4 to branch the oil. A passage 8 in which a large amount of mixed gas flows in the central portion of the valve mechanism 6 that drives the rocker arm 5 that opens and closes the intake valve 3 and the exhaust valve is provided, and the passage 8 toward the valve mechanism 6 is provided. A check valve 7 on the side of the passage 8 is provided at the outlet 8a, and a flow passage 12 through which a mixed gas flows is provided between the crank chamber 11 and the chamber 10 of the valve mechanism 6; The chamber 10 of the valve mechanism 6 serves also as a mixed gas vent pipe, and the mixed gas is sucked into the chamber 10 and the rocker arm chamber 14 of the valve mechanism 6.
[0019]
Thus, the chamber 10 of the valve mechanism 6 serves also as a mixed gas ventilation pipe, and the mixed gas containing a large amount of oil flowing into the chamber 10 of the valve mechanism 6 through the passage 8 is Since the rocker arm chamber 14 is configured to be sucked through the chamber 10 of the valve mechanism 6, oil contained in the mixed gas is attached to the intake valve 3, the exhaust valve, and the rocker arm 5 that opens and closes the valve. Lubrication can be improved.
[0020]
According to a fourth aspect of the present invention, a flow passage 12 is provided between the crank chamber 11 and the chamber 10 of the valve operating mechanism 6 so that a mixed gas flows between them. The gap between the cam 6b and timing gears 6c and 6c for driving the push rod 6a of the rocker arm 5 for opening and closing the intake valve 3 and the exhaust valve, which are constituent members of the mechanism unit 6, and the chamber 10 of the valve mechanism unit 6 is as follows. The mixed gas flows smoothly, and the oil contained in the mixed gas adheres to the cam 6b and the timing gears 6c and 6c, and is set to a narrow gap that can be scraped up by the rotation of the cam 6b and the timing gears 6c and 6c. It is composed.
[0021]
As described above, by providing the flow passage 12 between the chamber 10 and the crank chamber 11 of the valve mechanism 6 to allow the mixed gas to flow therethrough, when the piston 13 is lifted, Along with the negative pressure, the mixed gas in the valve mechanism 6 is sucked into the crank chamber 11, and the mixed gas in the crank chamber 11 is compressed and flows to the valve mechanism 6 when the piston 13 is lowered. That is, as the piston 13 moves up and down, the mixed gas moves between the valve operating mechanism 6 and the crank chamber 11, and the oil contained in the mixed gas rotates in the valve operating mechanism 6 and the crank chamber 11. The connecting rod 19 can be sufficiently attached to the connecting portion of the connecting rod 19, and the oil attached to the connecting portion can splash the piston 13 and the cylinder 9 to sufficiently lubricate the piston 13 and the cylinder 9.
[0022]
Furthermore, when a desired narrow gap is set between the chamber 10 of the valve mechanism 6 and the cam 6b and timing gear 6c which are constituent members of the valve mechanism 6, the cam 6b and timing gear 6c rotate. The oil accumulated in the narrow gap can be swept up by a cam or timing gear to make the oil splash, thereby improving the lubrication of the entire valve mechanism.
[0023]
The invention according to claim 5 is the oil stored in the rocker arm chamber 14 between the upper surface 4 b of the intake passage 4 from the carburetor 1 to the intake valve 3 of the cylinder head 2 and the rocker arm chamber 14. Is provided with a circulation passage 15 through which a mixed gas containing a large amount of gas can circulate in the intake passage 4. The cross-sectional area of the circulation passage 15 is set to a value smaller than 1/5 of the cross-sectional area of the intake passage 4.
[0024]
By providing the mixed gas circulation passage 15 containing a large amount of oil as described above, the mixed gas containing a large amount of oil stored in the rocker arm chamber 14 returns to the intake passage 4 through the circulation passage 15. In the intake stroke of the engine, it is sucked into the cylinder together with the mixed gas from the carburetor, and the suction efficiency of the mixed gas can be improved.
[0025]
In these drawings, reference numeral 16 denotes a coil spring that urges the intake valve 3 in the valve closing direction, and 17 denotes a crankshaft supported by a bearing 18 and projecting at both ends from the crank chamber 11. A connecting rod 19 is provided between the crankpin 17 a in the cylinder 11 and the piston 13. A rotor 20 is attached to the left end of the crankshaft 17 in the figure. A cooling fan 20 a is attached to the inner surface of the rotor 20, and a permanent magnet 20 b is provided on a part of the peripheral surface of the rotor 20. 21 is an ignition coil, 21a is an iron core of the ignition coil 21, and a high voltage is generated in the ignition coil 21 each time the permanent magnet 20b on the peripheral surface of the rotor 20 passes close to the iron core 21a. A high voltage is applied to the spark plug 23 via the high voltage cord 22.
[0026]
Reference numeral 24 denotes a centrifugal clutch shoe attached to the outer surface of the rotor 20, and a clutch drum 26 attached to the end of the rotary output shaft 25 is interposed on the outer periphery of the centrifugal clutch shoe 24 so that the engine rotates at a predetermined speed. If it becomes above, the said centrifugal clutch shoe 24 will contact the said clutch drum 26 with a centrifugal force, and the rotational force of the crankshaft 17 will be transmitted to the rotation output shaft 25. FIG.
[0027]
A recoil starter 27 is provided on the right side of the crankshaft 17 in the drawing to pull the starter rope 27a and rotate the crankshaft 17 when starting the engine. 28 is a fuel tank, 28a is a fuel tank cap, 29 is an air cleaner, 30 is an air cleaner cover, 31 is a weighted filter 32 attached to one end, and the other end is connected to the carburetor 1. The fuel pipe 33 is inserted into the fuel tank 28 at one end and the overflow pipe 34 is connected to the carburetor 1 at the other end, and 34 is provided outside the bearings 18 and 18 that support the crankshaft 17. This is a seal member provided so that the mixed gas that has passed through does not escape to the outside.
[0028]
【The invention's effect】
Since the invention described in claim 1 is configured as described above, that is, by providing an intake passage from the carburetor directly to the intake valve, the mixed gas from the carburetor is directly taken into the intake stroke during the intake stroke of the engine. Since the intake gas is supplied to the valve, the intake efficiency of the mixed gas into the cylinder is increased when the intake valve is opened, thereby improving the output of the engine.
On the other hand, a mixed gas containing a large amount of oil is branched from the bottom surface of the intake passage from the carburetor to the intake valve, and the center in the vertical direction of the valve mechanism that drives the rocker arm that opens and closes the intake and exhaust valves. In the crank chamber And rocker arm chamber So that the outlet to the valve mechanism part faces the vertical position range of the push rod of the valve mechanism part, and a check valve is provided. Further, the cylinder head is formed in a straight line with a constant circular cross section from the branch portion with the intake passage to the outlet to the valve operating mechanism side. By providing the passage, the mixed gas containing a large amount of oil is sucked by the rocker arm that opens and closes the intake valve and the exhaust valve through the passage and the valve mechanism that drives the rocker arm, and the mixed gas The oil contained in can be adhered sufficiently to provide a lubricating action.
That is, most of the mixed gas is sucked into the cylinder during the intake stroke of the engine to improve the suction efficiency, while the mixed gas containing a large amount of oil is sucked into the valve mechanism through the passage and lubricated. Can be better.
[0029]
Further, since the invention according to claim 2 is configured as described above, that is, between the chamber of the valve mechanism and the crank chamber, there is a flow passage through which a mixed gas flows. As a result, the mixed gas in the valve mechanism is sucked into the crank chamber along with the negative pressure in the crank chamber when the piston is raised, and the mixed gas in the crank chamber is compressed when the piston is lowered to move the valve mechanism Flowing into. That is, the connecting rod is connected by connecting the oil contained in the mixed gas to the crank pin that rotates in the valve operating mechanism and the crank chamber by moving the piston between the valve operating mechanism and the crank chamber by moving the piston up and down. In addition, the oil adhering to the connecting portion can be splashed onto the piston and the cylinder to sufficiently lubricate the piston and the cylinder.
In particular, since a mixed gas containing a large amount of oil flows between the crank chamber and the valve mechanism mechanism chamber, a timing gear or cam disposed near the crank chamber in the valve mechanism portion. Thus, the oil contained in the mixed gas can be sufficiently adhered to the portion that needs the most lubrication, such as the lower end portion of the push rod pushed by the cam.
[0030]
Further, since the invention according to claim 3 is configured as described above, that is, an intake passage is provided from the carburetor directly to the intake valve of the cylinder head, and the oil passage is branched from the bottom surface of the intake passage. The mixed gas containing a large amount of the crank chamber at the center in the vertical direction of the valve mechanism that drives the rocker arm that opens and closes the intake and exhaust valves And rocker arm chamber So that the outlet to the valve operating mechanism side faces the position range of the push rod of the valve operating mechanism in the vertical direction. Furthermore, the cylinder head is linearly formed in the thick part of the cylinder head from the branching portion with the intake passage to the outlet to the valve operating mechanism side. A passage is provided, and a check valve to the passage side is provided at the outlet of the passage toward the valve mechanism portion. Between the crank chamber and the valve mechanism portion, there is a flow of mixed gas between the two. Since the flow path to be performed is provided, the valve mechanism mechanism chamber also serves as a ventilation pipe, and the mixed gas is configured to be sucked into the valve mechanism mechanism chamber and the rocker arm chamber. The mixed gas travels between the valve mechanism and the crank chamber, so that the oil can sufficiently adhere to the timing gear and the cam at the lower part of the valve mechanism, and the crank pin rotating in the crank chamber It is possible to sufficiently adhere to the connecting portion of the connected connecting rods, and further, the oil adhering to the connecting portion jumps to the piston and the cylinder to sufficiently lubricate the piston and the cylinder.
Further, since the chamber of the valve mechanism part serves as a ventilation pipe and communicates with the rocker arm chamber, the oil contained in the mixed gas is sufficiently adhered to the push rod and the rocker arm in the upper part of the valve mechanism part. I can do it.
[0031]
Further, since the invention according to claim 4 is configured as described above, that is, between the chamber of the valve operating mechanism and the crank chamber, a flow passage through which a mixed gas is circulated is provided. As a result, when the piston rises, the mixed gas in the valve mechanism is sucked into the crank chamber along with the negative pressure in the crank chamber, and when the piston moves down, the mixed gas in the crank chamber is compressed to the valve mechanism. Flowing. That is, the connecting rod is connected by connecting the oil contained in the mixed gas to the crank pin that rotates in the valve operating mechanism and the crank chamber by moving the piston between the valve operating mechanism and the crank chamber by moving the piston up and down. Further, the oil adhering to the connecting portion can be splashed onto the piston or cylinder to sufficiently lubricate the piston or cylinder.
Further, since a narrow desired gap is set between the valve mechanism mechanism chamber and the cam and timing gear which are constituent members of the valve mechanism section, the cam and timing gear are stored in the narrow gap when the cam and timing gear rotate. A cam or timing gear scoops up the oil and splashes the oil to improve lubrication of the entire valve mechanism.
[0032]
The invention according to claim 5 is configured as described above, that is, between the upper surface of the intake passage from the carburetor to the intake valve of the cylinder head, and the rocker arm chamber. By providing a circulation passage through which the mixed gas containing a large amount of oil stored in the intake passage can be circulated, the mixed gas containing a large amount of oil stored in the rocker arm chamber passes through the circulation passage. Then, in the intake stroke of the engine, it is sucked into the cylinder together with the mixed gas from the carburetor, and the suction efficiency of the mixed gas can be improved.
[Brief description of the drawings]
FIG. 1 is a side view showing a valve operating mechanism that opens and closes an intake valve and an exhaust valve provided with an intake and lubrication device for a four-cycle engine according to the present invention.
FIG. 2 is a longitudinal sectional view of a four-cycle engine provided with an intake / lubricating device according to the present invention.
FIG. 3 is a diagram showing a part of the configuration of the intake / lubricating device of the present invention;
FIG. 4 is a view showing another part of the configuration of the intake / lubricating device of the present invention.
[Explanation of symbols]
1 Carburetor
2 Cylinder head
3 Intake valve
4 Intake passage
4a Bottom
4b Top surface
5 Rocker arm
6 Valve mechanism
6a push rod
6b cam
6c Timing gear
7 Check valve
8 passage
8a Exit
9 cylinders
10 rooms
11 Crank chamber
12 Flow path
13 Piston
14 Rocker arm room
15 Circulation passage
16 Coil spring
17 Crankshaft
17a Crank pin
18 Bearing
19 Connecting rod
20 Rotor
20a Cooling fan
20b Permanent magnet
21 Ignition coil
21a iron core
22 High voltage cord
23 Spark plug
24 Centrifugal clutch shoe
25 Rotation output shaft
26 Clutch drum
27 Recoil starter
27a Starter rope
28 Fuel tank
28a Fuel tank cap
29 Air cleaner
30 cover
31 Fuel pipe
32 Filter with weight
33 Overflow pipe
34 Sealing member

Claims (6)

An intake passage that leads directly from the carburetor to the intake valve of the cylinder head is provided, and a rocker arm that branches off from the bottom of the intake passage and that opens and closes the intake and exhaust valves is driven by a mixed gas containing a large amount of oil. The outlet range to the valve mechanism section side is the position range of the push rod of the valve mechanism section in the vertical direction so that it flows directly to the central part in the vertical direction of the valve mechanism section without passing through the crank chamber and the rocker arm chamber. A passage formed in the thick part of the cylinder head in a straight line with a constant circular cross section from the branching portion with the intake passage to the outlet to the valve operating mechanism side. An intake and lubrication device for a four-cycle engine, characterized in that An intake passage that leads directly from the carburetor to the intake valve of the cylinder head is provided, and a rocker arm that branches off from the bottom surface of the intake passage and that opens and closes the intake and exhaust valves is driven by a mixed gas containing a large amount of oil. The outlet range to the valve mechanism section side is the position range of the push rod of the valve mechanism section in the vertical direction so that it flows directly to the central part in the vertical direction of the valve mechanism section without passing through the crank chamber and the rocker arm chamber. A passage formed in the thick part of the cylinder head in a straight line with a constant circular cross section from the branching portion with the intake passage to the outlet to the valve operating mechanism side. And a flow passage through which a mixed gas flows between the chamber of the valve operating mechanism and the crank chamber is provided. An intake passage that leads directly from the carburetor to the intake valve of the cylinder head is provided, and a rocker arm that branches off from the bottom surface of the intake passage and that opens and closes the intake and exhaust valves is driven by a mixed gas containing a large amount of oil. The outlet to the valve mechanism is within the vertical position range of the push rod of the valve mechanism so that it flows directly to the center of the valve mechanism in the vertical direction without going through the crank chamber and rocker arm chamber . extraordinary seen further from said branch portion of the intake passage to the outlet to the valve mechanism portion side, it provided a certain passage formed in the thick portion of the cylinder head in a straight line with a circular cross-section, movement of the passage A check valve to the passage side is provided at the outlet to the valve mechanism portion side, and a flow passage is provided between the crank chamber and the valve mechanism portion between which the mixed gas flows, Ventilation chamber is ventilated The doubles, mixed gas intake and lubrication system for a four-cycle engine, characterized by being configured so as to be sucked into the chamber of the chamber and the rocker arm of the valve operating mechanism. A flow passage is provided between the crank chamber and the valve mechanism mechanism chamber so that a mixed gas flows between them, and the intake valve and exhaust valve, which are constituent members of the valve mechanism mechanism, are opened and closed. The gap between the cam and timing gear that drives the push rod of the drive rocker arm and the chamber of the valve mechanism mechanism allows the mixed gas to flow smoothly, and the oil contained in the mixed gas adheres to the cam and timing gear, 4. The intake / lubricating device for a 4-cycle engine according to claim 2, wherein the clearance is set to a narrow gap that can be scraped up by rotation of a cam or a timing gear. A mixed gas containing a large amount of oil stored in the rocker arm chamber can circulate in the intake passage between the upper surface portion of the intake passage from the carburetor to the intake valve of the cylinder head and the chamber of the rocker arm. The intake / lubricating device for a 4-cycle engine according to any one of claims 1 to 4, wherein a circulation passage is provided. The intake passage has a circular cross section and extends horizontally.
Said passage, said a smaller diameter than the diameter of the intake passage is extended in a horizontal shape,
The axial center of the intake passage and the axial center of the passage are in a twisted positional relationship,
The opening of the passage is formed on the lower peripheral surface side of the intake passage so as to include the bottom of the intake passage, and the opening area is set larger than that when the two shaft centers intersect. The intake / lubricating device for a four-cycle engine according to any one of claims 1 to 5, wherein

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