JP2013147963A - Engine chain saw - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide an engine chain saw configured to improve cooling performance of an engine cylinder.SOLUTION: An engine chain saw is provided with a saw chain 6 driven by an engine, an oil pump 8 supplying lubricating oil to the saw chain 6, an oil supply pipe 11 to supply oil to the saw chain 6, and an oil tank 7 storing the lubricating oil. A flow channel 32 leading from an inlet 34 to an outlet 35 is provided inside an engine cylinder. A flow channel is formed by connecting an oil pump discharge port 85 to the inlet 34 and connecting the outlet 35 to the oil supply pipe 11 to the saw chain 6. The lubricating oil flows inside the cylinder to enhance cooling performance of the cylinder.

Description

  The present invention relates to an engine chain saw, and more particularly to an engine chain saw having a cooling mechanism with an improved lubricating oil feeding method.

  As shown in FIGS. 7 to 9, the conventional engine chain saw 201 has an internal combustion type having an intake port portion 9 for sucking air-fuel mixture and an exhaust port portion 10 for discharging combustion gas on the side wall of a cylinder 3 for reciprocally guiding the piston 2. The saw chain 6 is driven by the engine 211 and is slidably guided along the outer periphery of the chamber 5 to be used for cutting wood. The engine chain saw 201 includes an oil tank 7 for storing oil to be supplied to the saw chain 6, and the lubricating oil in the oil tank 7 is sucked out by the oil pump 8 to lubricate the saw chain 6 sliding guide portion. To the sliding guide. On the opposite side of the crankshaft 4 from the saw chain drive side end, a fan 13 is provided as shown in FIG. 8, and a starter coil 14 is attached adjacent to the fan 13 as shown in FIG. The fan 13 is formed integrally with the flywheel, and the engine 211 is cooled by guiding the wind to the vicinity of the cylinder 3 of the engine by the fan 13 and the air passage 15 (FIG. 8). The flow direction of the cooling air by the fan 13 exits from the air passage 15 straight upward (in the direction parallel to the paper surface of FIG. 8) by a guide (not shown), and near the upper portion (head) of the cylinder 3 (not shown). And a flow (arrow C) that is bent almost vertically (perpendicular to the plane of the drawing in FIG. 8) and hits the upper portion (head) of the cylinder 3 (arrow C), and rises obliquely upward and rearward (in the direction parallel to the drawing of FIG. 8) from the air passage 15. However, there is a flow (arrow D) that turns into the direction perpendicular to the paper surface, that is, from the intake port 9 side to the upper side of the cylinder 3 or the back side (the direction perpendicular to the paper surface in FIG. 8). The flow that mainly contributes to the cooling of the cylinder is the former flow.

Japanese Utility Model Publication No.59-35362

  By the way, in the engine of a chain saw like patent document 1, a catalyst is sometimes used for the reduction | decrease of exhaust gas in recent years, and an engine cylinder tends to become still higher temperature. When the temperature of the engine becomes high, there is a problem in that output reduction or seizure is likely to occur, and workability is significantly deteriorated due to output reduction or repair.

  The present invention has been made in view of the above problems, and an object of the present invention is to provide an engine chain saw that improves engine cooling performance and prevents seizure and the like, improves durability, and improves workability. .

  In order to achieve the above object, an engine chain saw according to the present invention supplies a piston, a cylinder for guiding the piston, an engine including a fan that applies cooling air to the cylinder, a saw chain driven by the engine, and lubricating oil to the saw chain. The oil pump, the oil supply pipe to the saw chain, and the oil tank for storing the lubricating oil are provided, and an oil passage is formed in the cylinder so as to flow around the cylinder (near the outer periphery of the cylinder). The cylinder has an inlet and outlet for the oil flow path, connected from the oil pump discharge port to the inlet of the flow path in the cylinder, and connected to the oil supply pipe to the saw chain. A communicating channel was provided.

  Further, as another configuration, the lubricating oil discharged from the oil pump discharge port is branched, one branched is connected to the inlet of the flow path in the cylinder, and the other branched is connected to the saw chain oil supply pipe. The oil that flows in from the inlet of the flow path in the cylinder and flows in the vicinity of the outer periphery of the cylinder is discharged from the outlet of the flow path and returns to the oil tank through the return flow path connected to the oil tank. The branch passage of the lubricating oil discharged from the oil pump discharge port is configured such that the cross-sectional area on the connection side to the inlet of the flow path in the cylinder is larger than the cross-sectional area on the connection side to the saw chain oil supply pipe. good. Further, it is preferable to connect a part of the return flow path connected to the flow path outlet in the cylinder to the oil tank after turning around the vicinity of the intake port 9 side.

  According to the first aspect of the present invention, a continuous flow path from the inlet to the outlet is provided inside the cylinder, the oil pump discharge port is connected to the inlet of the flow path in the cylinder, and the outlet of the flow path in the cylinder is connected to the saw chain. Since the flow path connected to and connected to the oil supply pipe is provided, when the engine is driven, the oil pump causes the lubricating oil in the oil tank to flow through the flow path in the cylinder and then to the saw chain side. Lubricating oil in the oil tank is cooler than the cylinder and is at about room temperature, so the low-temperature lubricating oil flows through the cylinder flow path, effectively cooling the cylinder, reducing seizure and other durability. Can be improved.

  According to the second aspect of the present invention, a continuous flow path from the inlet to the outlet is provided inside the cylinder, the connection from the oil pump discharge port to the flow path inlet in the cylinder, and the oil pump discharge port to the saw chain oil supply pipe. Branched to the connection. In addition, a return channel connected to the oil tank from the channel outlet in the cylinder was provided. For this reason, the lubricating oil in the oil tank can be circulated between the flow path in the cylinder and the oil tank, and the flow rate of the lubricating oil to the flow path in the cylinder can be increased to further increase the cylinder cooling effect. it can.

  According to the invention of claim 3, at the branch point from the oil pump discharge port, the flow area on the connection side to the inlet of the flow path in the cylinder is larger than the flow area on the connection side to the saw chain oil supply pipe. In addition to increasing the flow rate of lubricating oil to the flow path in the cylinder and decreasing the flow rate of lubricating oil to the saw chain side, the amount of oil supplied to the saw chain side can be maintained appropriately. The cylinder can be cooled effectively.

  According to the invention of claim 4, since a part of the return flow path connected to the outlet in the cylinder flow path is connected to the oil tank after turning around the vicinity of the intake port, the wind from the fan is Cooling of the oil which hits a part and returns to the oil tank is promoted, and the cylinder can be cooled effectively. Furthermore, since the air that is not the main cooling air of the cylinder is returned and used for cooling the lubricating oil, the cylinder can be effectively cooled while suppressing a decrease in the cylinder cooling efficiency due to the air.

1 is a perspective view showing an external appearance of an engine chain saw according to an embodiment of the present invention. It is the side view by the side of the oil pump of the engine chain saw which concerns on the Example of this invention, Comprising: It is the figure which showed the part with sectional drawing. FIG. 3 is a partially enlarged sectional view in the vicinity of a cylinder in FIG. 2. It is a partial expanded sectional view of the oil pump side principal part of the engine chain saw which concerns on 2nd Example of this invention. It is the figure which showed the fan 13 vicinity of the engine chain saw which concerns on 3rd Example of this invention with sectional drawing. FIG. 6 is a cross-sectional view that passes through the vicinity of the crankshaft and the vicinity of the intake port 9 of FIG. 5. It is the side view of the conventional engine chain saw, and is the figure which showed the structure of the oil pump 8 vicinity with sectional drawing. It is the side view of the conventional engine chain saw, and is the figure which showed the fan 13 vicinity with sectional drawing. It is a cross-sectional view which passes along the crankshaft 4 vicinity of the conventional engine chain saw.

  Hereinafter, embodiments of the present invention will be described with reference to FIGS. In the following drawings, the same portions are denoted by the same reference numerals, and repeated description is omitted.

  As shown in FIG. 1, an engine chain saw 101 equipped with a two-cycle engine 1 that uses mixed gasoline or the like as a fuel has a saw chain 6 attached to the outer periphery of the chamber 5 and the engine 1 attached to the rear end side of the chamber 5. . The output of the engine 1 is transmitted from the crankshaft 4 (see FIG. 2) to the saw chain 6 via a sprocket. An operator operates the engine chain saw 101 by holding the front handle 112 and the rear handle 113 attached to the engine case 114.

  As shown in FIGS. 2 and 3, a cylindrical cylinder liner 31 is fitted on the inner peripheral side of the cylinder block 30 of the engine 1 of this embodiment. A continuous groove is provided on the outer peripheral side of the cylinder liner 31, and the cylinder liner 31 is fitted into the inner periphery of the cylinder block 30 to form the in-cylinder flow path 32. One end of the groove formed on the outer peripheral side of the cylinder liner 31 is connected to a groove extending from an inlet 34 formed in the cylinder block 30, and the other end is connected to a groove extending from an outlet 35 formed in the cylinder block 30. . The two grooves connected to the inlet 34 and the outlet 35 are formed so as to wind the cylinder liner at a predetermined interval, that is, to extend upward in a spiral shape, and by connecting these grooves at the upper end portion. The in-cylinder flow path 32 communicating from the inlet 34 to the outlet 35 is formed. The arrangement of the in-cylinder flow path 32 is arbitrary, and other arrangements and formation methods may be used in addition to the spiral formation as in the present embodiment.

  An oil pump 8 is provided below the crankshaft 4. As the oil pump 8, a known oil pump driven by a worm 83 fixed to the crankshaft 4 can be used. A suction pipe 81 extending inside the oil tank 7 is connected to the suction port of the oil pump 8, and a discharge pipe 85 connected to the inlet 34 of the in-cylinder flow path 32 is connected to the discharge port of the oil pump 8. An oil supply pipe 11 for connecting to the chamber oil supply port 12 is connected to the outlet 35 side of the in-cylinder flow path 32.

  According to the engine chain saw 101 configured in this manner, when the engine 1 is started, the crankshaft 4 rotates, the saw chain 6 is driven around the chamber 5 and the oil pump 8 is operated simultaneously, and lubrication in the oil tank 7 is performed. Oil is sucked out of the oil tank 7. At this time, the sucked lubricating oil flows through the suction pipe 81, the oil pump 8, and the discharge pipe 85 to the inlet 34 of the in-cylinder flow path 32 as indicated by an arrow A. The lubricating oil that has flowed around the outer periphery of the cylinder liner 31 in the in-cylinder flow path 32 flows out from the outlet 35 to the oil supply pipe 11 as shown by the arrow B and flows to the chamber oil supply port 12. And the sliding part of the saw chain 6 and the chamber 5 is lubricated. Here, the lubricating oil in the oil tank 7 is at a normal temperature and is sufficiently lower than the temperature of the cylinder 3 during operation. Therefore, normal temperature lubricating oil flows through the in-cylinder flow path 32 to promote cooling of the cylinder 3 and prevent seizure or the like. Note that the lubricating oil flowing through the in-cylinder flow path 32 is a space separated from the combustion chamber, and therefore is not mixed with the lubricating oil for the engine existing on the piston 2 side.

  Next, a second embodiment of the present invention will be described with reference to FIG. In the first embodiment shown in FIGS. 2 and 3, the lubricating oil sucked out by the oil pump 8 is supplied to the saw chain 6 after flowing through the in-cylinder flow path 32. However, in the second embodiment, the flow path of the lubricating oil sucked out by the oil pump 8 is branched, a part of the lubricating oil is guided to the in-cylinder flow path 32, and the rest is directly supplied to the saw chain 6. Configured. 4, the in-cylinder flow path 32 is the same as that in FIG. 2, but a branch portion 90 is provided in the discharge pipe 85 of the oil pump 8, and one is connected from the branch portion 90 to the inlet 34 of the in-cylinder flow path 32. The other one is connected to the first discharge pipe 91, and the other one is connected to the second discharge pipe 92 connected from the branch portion 90 to the oil supply pipe 11 on the chamber 5 side. The lubricating oil flowing in from the inlet 34 in the direction of arrow A flows out of the outlet 35 in the direction of arrow B after flowing through the in-cylinder channel 32. Since the outlet 35 of the in-cylinder flow path 32 is connected to the return pipe 20 connected to the oil tank 7, the lubricating oil that has flowed through the in-cylinder flow path 32 returns to the oil tank 7 and is reused. Note that the flow rate of the lubricating oil flowing through the first discharge pipe 91 and the flow rate of the lubricating oil flowing through the second discharge pipe 92 at the branch portion 90 are based on the required cooling amount of the cylinder 3 and the required oil supply amount to the saw chain 6. It is preferable to select optimally. For example, the flow area of the second discharge pipe 92 is preferably smaller than the flow area of the first discharge pipe 91.

  According to the engine chain saw 101 configured as described above, when the engine 1 is driven, the saw chain 6 is driven around the chamber 5. At the same time, the oil pump 8 is also driven, and the lubricating oil in the oil tank 7 is sucked out from the oil tank 7, and the suction pipe 81, the oil pump 8, the discharge pipe 85, the branch part 90, the first discharge pipe 91, the in-cylinder flow path. 32, flows through the return pipe 20 to the oil tank 7. On the other hand, the gas flows from the branching portion 90 through the second discharge pipe 92 and the oil supply pipe 11 to the chamber oil supply port 12. And the sliding part of the saw chain 6 and the chamber 5 is lubricated. In this case, the lubricating oil flowing through the in-cylinder flow path 32 is sucked out of the oil tank 7 and returns to the oil tank 7. Due to the difference in the size of the flow path area at the branch portion 90, a large amount of lubricating oil flows into the in-cylinder flow path 32, and a small amount of flow toward the chamber oil supply port 12 side. The lubricating oil in the oil tank 7 is at an ordinary temperature at the initial stage, and the temperature is lower than that of the cylinder 3 even after driving. Lubricating oil at normal temperature circulates in the flow path 32 in the cylinder and flows in a large amount to further promote cooling of the cylinder 3 to prevent seizure and the like. It can be suppressed.

  Next, a third embodiment of the present invention will be described with reference to FIGS. In the second embodiment shown in FIG. 4, the lubricating oil flowing through the in-cylinder flow path 32 is returned to the oil tank 7 and sucked and circulated. However, the oil is immediately supplied from the outlet 55 of the in-cylinder flow path 32. This is a configuration of a return pipe returning to the tank 7. However, in the third embodiment, a part of the return pipe 40 connected to the outlet 55 of the in-cylinder flow path 32 is returned to the oil tank 7 after turning the vicinity of the intake port 9 side. Yes. In FIG. 5, the path to the oil tank 7, the oil pump 8, and the in-cylinder flow path 32 is the same as that in FIG. 4, but the outlet 55 of the in-cylinder flow path 32 is on the fan 13 side and the return pipe 40 connected thereto. The intermediate portion of the oil tank 7 is connected to the oil tank 7 after the vicinity of the intake port 9 side (the lower side of the intake port 9 in FIGS. 5 and 6) is turned.

  According to the engine chain saw 101 configured as described above, the flow of the lubricating oil after the engine 1 is driven includes a circulating flow returning from the oil tank 7 to the oil tank 7 via the in-cylinder flow path 32 and the return pipe 40, and a saw chain. 4 is the same as FIG. 4 except that the middle part of the return pipe 40 is arranged near the intake port 9 side, so that a part of the cooling air of the fan 13 is hit and cooled. The Then, the lubricating oil flowing in the return pipe 40 also returns to the oil tank 7 after being urged to cool. Accordingly, the temperature of the lubricating oil circulating through the in-cylinder flow path 32 can be made lower than that in the case of FIG. 4, and the cylinder 3 can be cooled effectively. Further, since the wind generated by the fan 13 flowing on the side of the air inlet 9 is not the main cooling air for the cylinder, it can be used effectively without reducing the cylinder cooling efficiency due to the wind even if it is used for cooling the return lubricant. Cylinder cooling can be effectively performed in combination with cooling by oil circulation.

  As mentioned above, although this invention was demonstrated based on the Example, this invention is not limited to the above-mentioned Example, A various deformation | transformation and improvement are possible. For example, in the above-described embodiment, the cylinder liner 31 having a groove on the outer periphery is fitted into the inner peripheral side of the cylinder block 30 to form the in-cylinder flow path 32. However, other manufacturing methods may be employed. A groove may be provided on the outer peripheral side of the cylindrical cylinder, and it may be formed by a cylindrical outer cover that is fitted on the cylinder. Further, the location where the in-cylinder flow path is provided is not limited to the entire outer peripheral surface of the cylinder, but may be a part of the outer peripheral surface or may be provided only around the cylinder head. The positions of the inlet 34 and the outlet 55 of the in-cylinder flow path 32 are not limited to the lower side of the cylinder 3 and may be appropriate positions.

1 Engine 2 Piston 3 Cylinder 4 Crankshaft 5 Chamber 6 Saw Chain 7 Oil Tank 8 Oil Pump 9 Intake Port 10 Exhaust Port 11 Oil Supply Pipe 12 Chamber Oil Supply Port 13 Fan 14 Starter Coil 15 Air Channel 20 Return Pipe 30 Cylinder Block 31 Cylinder Liner 32 In-cylinder flow path 34 Inlet 35 (in-cylinder flow path) Inlet 35 (In-cylinder flow path) Outlet 40 Return pipe 55 (In-cylinder flow path) Outlet 81 Suction pipe 83 Warm 85 Discharge pipe 90 Branch portion 91 First Discharge pipe 92 Second discharge pipe 101 Engine chain saw 112 Front handle 113 Rear handle 114 Engine case 201 Engine chain saw 211 Engine 211 Internal combustion engine

Claims (4)

An engine including a piston and a cylinder for guiding the piston;
A saw chain driven by the engine;
An oil pump for supplying lubricating oil to the saw chain;
An oil supply pipe to the saw chain;
In an engine chain saw comprising an oil tank for storing the lubricating oil,
Provide a continuous flow path from the inlet to the outlet around the cylinder,
An engine chain saw, wherein the discharge port of the oil pump is connected to the inlet, and the outlet is connected to the oil supply pipe. An engine including a piston and a cylinder for guiding the piston;
A saw chain driven by the engine;
An oil pump for supplying lubricating oil to the saw chain;
An oil supply pipe to the saw chain;
In an engine chain saw comprising an oil tank for storing the lubricating oil,
Provide a continuous flow path from the inlet to the outlet around the cylinder,
A branch from the discharge port of the oil pump to the inlet and a connection from the discharge port of the oil pump to the oil supply pipe are arranged,
An engine chain saw comprising a return flow path connected from the outlet to the oil tank.   3. The engine chain saw according to claim 2, wherein, in the branch, a flow area on a connection side to an inlet of a flow path inside the cylinder is larger than a flow area on a connection side to the saw chain refueling pipe. . 4. The engine chain saw according to claim 2, wherein a part of the return flow path connected to the outlet is turned around the intake side of the cylinder and the other end is connected to the oil tank. 5. .

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