JPS6116083Y2 - - Google Patents

Description

[Detailed Description of the Invention] The present invention relates to a chain saw for cutting trees and the like using a saw chain rotated by an engine.

Conventionally, in this type of chain saw, the oil tank was pressurized by the pressure inside the engine's crankcase, and lubricating oil was pumped to the saw chain for lubrication. At the connecting portion of the pressurizing passage, there were problems such as incomplete positioning, making it impossible to maintain airtightness, and vibrations causing the connection between the engine and the engine case to loosen, resulting in damage to the joint.

The present invention provides a connecting cylinder made of a rigid material for this pressurizing passage, and one end of this connecting cylinder is fixed to either the crankcase or the engine case, and is inserted into the fitting hole provided in the other. , by engaging the other end of the connecting cylinder, it ensures airtightness of the connecting part of the pressurizing passage, and also prevents loosening of the connection between the engine and the engine case, and prevents damage to the connecting part. It is.

Hereinafter, one embodiment of the present invention will be described in detail with reference to the drawings.

In the figure, 1 is an engine fixed in an engine case 3 by screws 5, 7 is a crankcase, 9 is a cylinder, and 11 is a carburetor. 13 is a front handle that is fixed to the engine case 3; 15 is a rear handle that is integrally formed with the engine case 3; 17 is an oil tank that is integrally formed with the engine case 3; and 19 is an oil tank cover. A saw chain 21 rotates around a guide bar 23 fixed to the side of the engine case 3, and is rotationally driven by the crankshaft 25 of the engine 1. 27 is a variable throttle valve provided between the crankcase 7 and the oil tank 17, and is constructed as follows. That is, 29 is a valve body that fits into a cylindrical part 31 provided in the engine case 3 that is integrated with the oil tank 17, and has a valve hole 3 that passes through the inside.
3 is opened and closed by the end of a control valve 35 that is screwed into the valve body 29. A check valve 37 is made of an elastic material such as rubber and communicates between the cylindrical portion 31 and the oil tank 17, and communicates only in the direction of the oil tank 17. 39 is a metal connecting cylinder whose one end is screwed into the crankcase 7, and whose other end is engaged with a fitting hole 41 provided in the cylindrical part 31 of the engine case 3 to position the crankcase 7 with respect to the engine case 3. is being carried out. 43 is a pressurizing passage that communicates between the crankcase 7 and the inside of the oil tank 17 via the inner diameter part of the connecting cylinder 39, the valve holes 3, 3, the cylindrical part 31, and the check valve 37. 45 is an oil supply pipe, 47 is a filter, 49 is a check valve, 51 is a throttle valve, and 53 is an oil supply part of the saw chain 21.

In the above embodiment, the saw chain 21 is rotated around the guide bar 23 by the engine 1 . The pressurized air in the crankcase 7 passes through the pressurizing passage 43 and pressurizes the oil tank 17 from the check valve 37 . Due to this pressurization, the lubricating oil in the oil tank 17 is sent to the oil supply section 53 of the saw chain 21 via the oil supply pipe 45 and is supplied therewith. When assembling the engine 1 to the engine case 3, connect the connecting tube 39 screwed onto the crankcase 7 to the engine case 3.
The engine 1 is fitted into the fitting hole 41 of the cylindrical portion 31 of the engine 1.
The crank case 7 is positioned and engaged with the engine case 3.

Since the present invention has the configuration as described in the claims, it can be positioned accurately and firmly, ensures airtightness of the connection part of the pressurizing passage, and prevents loosening of the engine and engine case. This can prevent damage to the joint.

It should be noted that the present invention is not limited to the above-mentioned embodiments, but can be implemented in other embodiments as well. Further, the symbols shown in the claims do not limit the technical scope of the present invention.

[Brief explanation of the drawing]

FIG. 1 is a side sectional view of one embodiment of the present invention, FIG. 2 is an enlarged side sectional view of the main part, and FIG. 3 is an explanatory diagram of the oil supply system. Explanation of the symbols representing the main parts of the drawing, 1...
Engine, 3...Engine case, 7...Crank case, 17...Oil tank, 21...Saw chain, 39...Connecting cylinder, 41...Fitting hole, 43
...Pressure passage.

Claims (1)

[Scope of utility model registration request] In a chain saw for cutting trees or the like with a saw chain 21 that rotates under the drive of an engine 1, an oil tank 17 is pressurized by the pressure in the crankcase 7 of the engine 1 to lubricate the saw chain 21. A connecting tube 39 made of a rigid material is provided in a pressurizing passage 43 communicating between the engine case 3 housing the engine 1 and the crankcase 7, and one end of the connecting tube 39 is connected to the crankcase 7 and the engine. A chain saw characterized in that the connecting tube 39 is fixedly provided on one side of the case 3 and the other end of the connecting tube 39 is engaged with a fitting hole 41 provided on the other side.