US3734070A - Engine body construction of a chain saw - Google Patents

Engine body construction of a chain saw Download PDF

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Publication number
US3734070A
US3734070A US00183346A US3734070DA US3734070A US 3734070 A US3734070 A US 3734070A US 00183346 A US00183346 A US 00183346A US 3734070D A US3734070D A US 3734070DA US 3734070 A US3734070 A US 3734070A
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United States
Prior art keywords
lubricating oil
oil tank
crank case
fuel tank
chain saw
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Legal status (The legal status is an assumption and is not a legal conclusion. Google has not performed a legal analysis and makes no representation as to the accuracy of the status listed.)
Expired - Lifetime
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US00183346A
Inventor
T Kobayashi
H Miyata
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Kioritz Corp
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Kioritz Corp
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Publication date
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    • B—PERFORMING OPERATIONS; TRANSPORTING
    • B27—WORKING OR PRESERVING WOOD OR SIMILAR MATERIAL; NAILING OR STAPLING MACHINES IN GENERAL
    • B27B—SAWS FOR WOOD OR SIMILAR MATERIAL; COMPONENTS OR ACCESSORIES THEREFOR
    • B27B17/00—Chain saws; Equipment therefor
    • F—MECHANICAL ENGINEERING; LIGHTING; HEATING; WEAPONS; BLASTING
    • F01—MACHINES OR ENGINES IN GENERAL; ENGINE PLANTS IN GENERAL; STEAM ENGINES
    • F01P—COOLING OF MACHINES OR ENGINES IN GENERAL; COOLING OF INTERNAL-COMBUSTION ENGINES
    • F01P1/00—Air cooling
    • F01P1/02—Arrangements for cooling cylinders or cylinder heads, e.g. ducting cooling-air from its pressure source to cylinders or along cylinders
    • F—MECHANICAL ENGINEERING; LIGHTING; HEATING; WEAPONS; BLASTING
    • F02—COMBUSTION ENGINES; HOT-GAS OR COMBUSTION-PRODUCT ENGINE PLANTS
    • F02B—INTERNAL-COMBUSTION PISTON ENGINES; COMBUSTION ENGINES IN GENERAL
    • F02B63/00—Adaptations of engines for driving pumps, hand-held tools or electric generators; Portable combinations of engines with engine-driven devices
    • F02B63/02—Adaptations of engines for driving pumps, hand-held tools or electric generators; Portable combinations of engines with engine-driven devices for hand-held tools
    • F—MECHANICAL ENGINEERING; LIGHTING; HEATING; WEAPONS; BLASTING
    • F02—COMBUSTION ENGINES; HOT-GAS OR COMBUSTION-PRODUCT ENGINE PLANTS
    • F02F—CYLINDERS, PISTONS OR CASINGS, FOR COMBUSTION ENGINES; ARRANGEMENTS OF SEALINGS IN COMBUSTION ENGINES
    • F02F1/00—Cylinders; Cylinder heads 
    • F02F1/002—Integrally formed cylinders and cylinder heads
    • F—MECHANICAL ENGINEERING; LIGHTING; HEATING; WEAPONS; BLASTING
    • F02—COMBUSTION ENGINES; HOT-GAS OR COMBUSTION-PRODUCT ENGINE PLANTS
    • F02B—INTERNAL-COMBUSTION PISTON ENGINES; COMBUSTION ENGINES IN GENERAL
    • F02B75/00—Other engines
    • F02B75/02—Engines characterised by their cycles, e.g. six-stroke
    • F02B2075/022—Engines characterised by their cycles, e.g. six-stroke having less than six strokes per cycle
    • F02B2075/025—Engines characterised by their cycles, e.g. six-stroke having less than six strokes per cycle two

Definitions

  • ABSTRACT In the construction of an engine body of a portable chain saw, a crank case, fuel tank and a lubricating oil tank are made integral. At least a part of the outside of the crank case is surrounded by the lubricating oil tank, and at least a part of the circumference of the latter is surrounded by the fuel tank.
  • a partition wall between the crank case and the lubricating oil tank is provided with a double wall construction having therein a space which opens at either one or both sides thereof, whereby cooling air may be drawn through the inside of the space.
  • This invention relates to an improvement of the construction of the engine body of a portable chain saw, and more particularly to the construction of the engine body of a portable chain saw in which the overheating of a fuel tank is prevented to ensure the smooth running of the engine.
  • a portable chain saw Since a portable chain saw has, in general, relatively a large output for its small size, the calorific value of the engine is large as much. Because of its small size, the heat generated through the calofication is liable to be transmitted to various portions of the chain saw adjacent to the engine. Accordingly, the temperature at those portions is likely to rise abruptly. Particularly in the event that the temperature at the fuel tank rises, the fuel therein is overheated, which results in malfunction of the engine.
  • an improved construction of an engine body of a portable chain saw wherein a crank case of the engine, a fuel tank and a lubricating oiltank are made integral, at least a part of the outside of the crank case being surrounded by the lubricating oil tank, at least a partof the circumference of the lubricating oil tank being surrounded by the fuel tank.
  • an improved construction of an engine body of a portable chain saw wherein a crank case of the engine, a fuel tank and a lubricating oil tank are made integral, at least a part of the outside of the crank case being surrounded by the lubricating oil tank, at least a part of the circumference of the lubricating oil tank being surrounded by the fuel tank so that adirect heattransmission from said crank case to said fuel tank may be shielded by said lubricating oil tank, a partition wall between said crank case and said lubricating oil tank being provided with a double wall construction having therein a space which opens at either one or both sides thereof whereby cooling air may be drawn throughthe inside of said space.
  • the primary object of the present invention as summarized above isto provide an engine body constructio n of a chain saw which the heat generated at the engine is prevented from transmitting directly to the fuel tank by the intervention of a lubricating oil tank between the engine and the fuel tank, whereby the temperature rise in the fuel tank is suppressed and the running of the engine is made normal and smooth.
  • FIG. 2 is a cross sectional 11-11 of FIG. 1.
  • DESCRIPTION o 'THE PREFERRED EMBODIMENT j view taken along the line trifugal clutch 14.
  • the other end of the crank shaft 13' is provided with a cooling fan 17 fixed thereto and further with a starting device 16.
  • the reference numeral 11 indicates a spike
  • 19 indicates a throttle lever
  • 20 indicates a stopping button for the throttle lever 19
  • 18a and 18b indicate handles, respectively.
  • a crank case 2 is made integral with a lubricating oil tank 4 and a fuel tank 7 by casting. Further, the outer wall of the crank case 2 serves as the inner wall of the lubricating oil tank 4..
  • the lubricating oil tank 4 is surrounded by a fuel tank 7.
  • the engine body housing including the crank case 2, the lubricating oil tank 4 and the fuel tank 7 is composed of two divisions dividable by a plane extending parallel to the axis of the crank shaft 13.
  • the reference numeral 6 indicates an inlet port for the lubricating oil
  • 8 indicates an inlet port for the fuel.
  • the lubricating oil in the lubricating oil tank 4 is sent to various portions to be lubricated in the chain saw by an oil supply 15 through a lubricating oil inhaling hose 5.
  • the boundary wall construction of the crank case 2 and the lubricating oil tank 4 is made of a double wall construction as shown in FIG. 1, so that cooling air may be drawn through the space 2a between the two walls of the double wall construction.
  • cooling air may be naturally drawn, this air, if necessary, is forcibly drawn by means of fan means such as an engine cooling fan as indicated by the numeral 17.
  • fan means such as an engine cooling fan as indicated by the numeral 17.
  • the heat generated from the engine 1 is distributed over the crank case with the maximum distribution on the cylinder head.
  • the cylinder head is cooled by cooling air blown off by an engine cooling fan 17.
  • the outer side of the crank case wall may be effectively cooled by the cooling air that is continuously drawn through the above space in the double wall construction, and thus the heat-transmission to the lubricating oil tank may be limited to that extent.
  • some part of the heat transmitted to the lubricating oil tank is accumulated in and warms the oil, a further heat transmission from the oil tank to the fuel tank 7 may be kept minimal so that the fuel in the fuel tank is effectively prevented from being abruptly heated.
  • the chain saw is not continuously driven for such a long time, but intermittently operated. Further, the amount of fuel and lubricating oil is limited to a comparatively small one, and accordingly, new fuel and oil is replenished after relatively a short time of driving. Therefore, the control of the heat transmission by the construction of the body housing is very effective to prevent the overheat of the fuel of the chain saw.

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  • Engineering & Computer Science (AREA)
  • Mechanical Engineering (AREA)
  • Chemical & Material Sciences (AREA)
  • Combustion & Propulsion (AREA)
  • General Engineering & Computer Science (AREA)
  • Life Sciences & Earth Sciences (AREA)
  • Wood Science & Technology (AREA)
  • Forests & Forestry (AREA)
  • Lubrication Details And Ventilation Of Internal Combustion Engines (AREA)

Abstract

In the construction of an engine body of a portable chain saw, a crank case, fuel tank and a lubricating oil tank are made integral. At least a part of the outside of the crank case is surrounded by the lubricating oil tank, and at least a part of the circumference of the latter is surrounded by the fuel tank. A partition wall between the crank case and the lubricating oil tank is provided with a double wall construction having therein a space which opens at either one or both sides thereof, whereby cooling air may be drawn through the inside of the space.

Description

United States Patent [191 Kobayashi et a1.
[54] ENGINE BODY CONSTRUCTION OF A CHAIN SAW [75] Inventors: Torao Kobayashi, Tokyo; Hiromasa Miyata, Mitaka, both of J apan [73] Assignee: Kioritz Corporation, Tokyo, Japan [22] Filed: Sept. 24, 1971 [21] Appl. No.: 183,346
[52] US. Cl. ..l23/41.31, l23/4l.7, 123/122 E,
123/136, 123/195 R, 143/32 [51] Int. Cl. ..F01p l/06, F02f 7/00 [58] Field of Search ..123/l95 R, 195 C,
123/195 P, 198 E, 122 E, 179 SE, 44.31, 41.7,136; 143/32; 74/606 [56] References Cited UNITED STATES PATENTS 3,036,566 5/1962 Dobbertin ..123/l98 E 3,372,679 3/1968 Aitken ..l23/l36 1 May 22, 1973 1 3,561,414 2/1971 Schou ..123/l36 FOREIGN PATENTS OR APPLICATIONS 651,976 11/1962 Canada 143/32 206,748 8/1966 Sweden ..143/32 Primary ExaminerAl Lawrence Smith Att0rneyKarl W. Flocks [57] ABSTRACT In the construction of an engine body of a portable chain saw, a crank case, fuel tank and a lubricating oil tank are made integral. At least a part of the outside of the crank case is surrounded by the lubricating oil tank, and at least a part of the circumference of the latter is surrounded by the fuel tank. A partition wall between the crank case and the lubricating oil tank is provided with a double wall construction having therein a space which opens at either one or both sides thereof, whereby cooling air may be drawn through the inside of the space.
1 Claim, 2 Drawing Figures PATENTEU HAYZ 2 I973 SHEET 2 [1F 2 1 ENGINE BODY CONSTRUCTION OF A CHAIN SAW BACKGROUND OF THE INVENTION This invention relates to an improvement of the construction of the engine body of a portable chain saw, and more particularly to the construction of the engine body of a portable chain saw in which the overheating of a fuel tank is prevented to ensure the smooth running of the engine.
Since a portable chain saw has, in general, relatively a large output for its small size, the calorific value of the engine is large as much. Because of its small size, the heat generated through the calofication is liable to be transmitted to various portions of the chain saw adjacent to the engine. Accordingly, the temperature at those portions is likely to rise abruptly. Particularly in the event that the temperature at the fuel tank rises, the fuel therein is overheated, which results in malfunction of the engine.
Under the conventional disposition as described above, it has been required to prevent the overheat of the fuel tank in the above kind of portable chain saw.
SUMMARY OF THE INVENTION In accordance with the presentinvention, there is provided an improved construction of an engine body of a portable chain saw wherein a crank case of the engine, a fuel tank and a lubricating oiltank are made integral, at least a part of the outside of the crank case being surrounded by the lubricating oil tank, at least a partof the circumference of the lubricating oil tank being surrounded by the fuel tank.
In accordance with the present invention, there is provided an improved construction of an engine body of a portable chain saw wherein a crank case of the engine, a fuel tank and a lubricating oil tank are made integral, at least a part of the outside of the crank case being surrounded by the lubricating oil tank, at least a part of the circumference of the lubricating oil tank being surrounded by the fuel tank so that adirect heattransmission from said crank case to said fuel tank may be shielded by said lubricating oil tank, a partition wall between said crank case and said lubricating oil tank being provided with a double wall construction having therein a space which opens at either one or both sides thereof whereby cooling air may be drawn throughthe inside of said space.
The primary object of the present invention as summarized above isto provide an engine body constructio n of a chain saw which the heat generated at the engine is prevented from transmitting directly to the fuel tank by the intervention of a lubricating oil tank between the engine and the fuel tank, whereby the temperature rise in the fuel tank is suppressed and the running of the engine is made normal and smooth.
Other objects,features andadvantages will be made apparent'from the description of the preferred embodiment described hereinbelow withreference to the accompanying drawing.
BRIEF DESCRIPTION or rn DRAWING and FIG. 2 is a cross sectional 11-11 of FIG. 1.
DESCRIPTION o 'THE PREFERRED EMBODIMENT j view taken along the line trifugal clutch 14. The other end of the crank shaft 13' is provided with a cooling fan 17 fixed thereto and further with a starting device 16. In the drawing, the reference numeral 11 indicates a spike, 19 indicates a throttle lever, 20 indicates a stopping button for the throttle lever 19, and 18a and 18b indicate handles, respectively.
In the present invention, as shown in the embodiment illustrated, a crank case 2 is made integral with a lubricating oil tank 4 and a fuel tank 7 by casting. Further, the outer wall of the crank case 2 serves as the inner wall of the lubricating oil tank 4.. The lubricating oil tank 4 is surrounded by a fuel tank 7. The engine body housing including the crank case 2, the lubricating oil tank 4 and the fuel tank 7 is composed of two divisions dividable by a plane extending parallel to the axis of the crank shaft 13.
The reference numeral 6 indicates an inlet port for the lubricating oil, and 8 indicates an inlet port for the fuel. The lubricating oil in the lubricating oil tank 4 is sent to various portions to be lubricated in the chain saw by an oil supply 15 through a lubricating oil inhaling hose 5.
Further, the boundary wall construction of the crank case 2 and the lubricating oil tank 4 is made of a double wall construction as shown in FIG. 1, so that cooling air may be drawn through the space 2a between the two walls of the double wall construction. Although said cooling air may be naturally drawn, this air, if necessary, is forcibly drawn by means of fan means such as an engine cooling fan as indicated by the numeral 17. By sending air blown into the space 2a by the fan 17 to cool the crank case, the heat transmission from the crank case to the fuel tank through the lubricating oil tank can be effectively shielded.
Furthermore, by mounting a piece of proper heat insulating material (not shown) to the surfaces 4a and 7a of the lubricating oil tank 4 and the fuel tank 7 opposite to the cylinder, the insulation of the heat transmission to the tanks can be further improved.
The heat generated from the engine 1 is distributed over the crank case with the maximum distribution on the cylinder head. The cylinder head is cooled by cooling air blown off by an engine cooling fan 17. On the crank case side of the engine, the outer side of the crank case wall may be effectively cooled by the cooling air that is continuously drawn through the above space in the double wall construction, and thus the heat-transmission to the lubricating oil tank may be limited to that extent. Although some part of the heat transmitted to the lubricating oil tank is accumulated in and warms the oil, a further heat transmission from the oil tank to the fuel tank 7 may be kept minimal so that the fuel in the fuel tank is effectively prevented from being abruptly heated.
In spite of the above steps of transmission of the heat, it should be understood that the fuel will finally by heated to the temperature as high as the crank case after a long time of driving of the engine.
However, in practical use, the chain saw is not continuously driven for such a long time, but intermittently operated. Further, the amount of fuel and lubricating oil is limited to a comparatively small one, and accordingly, new fuel and oil is replenished after relatively a short time of driving. Therefore, the control of the heat transmission by the construction of the body housing is very effective to prevent the overheat of the fuel of the chain saw.
What is claimed is:
1. An engine body construction of a chain saw comis surrounded by said fuel tank so that a direct heat-n transmission from said crank case to said fuel tank may be shielded by said lubricating oil tank, a partition wall between said crank case and said lubricating oil tank is provided with a double wall construction having therein a space which opens at either one or both sides thereof, whereby cooling air may be drawn through the inside of said space.

Claims (1)

1. An engine body construction of a chain saw comprising a crank case of an engine, a fuel tank and a lubricating oil tank, wherein said case, said fuel tank and said lubricating oil tank are made integral with each other, at least a part of the outer side of said crank case is surrounded by said lubricating oil tank, and at least a part of the circumference of said lubricating oil tank is surrounded by said fuel tank so that a direct heat-transmission from said crank case to said fuel tank may be shielded by said lubricating oil tank, a partition wall between said crank case and said lubricating oil tank is provided with a double wall construction having therein a space which opens at either one or both sides thereof, whereby cooling air may be drawn through the inside of said space.
US00183346A 1971-09-24 1971-09-24 Engine body construction of a chain saw Expired - Lifetime US3734070A (en)

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Cited By (5)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
US4382333A (en) * 1980-03-31 1983-05-10 Kioritz Corporation Chain saw
US4571833A (en) * 1983-08-30 1986-02-25 Kioritz Corporation Sawdust discharge port
US4756396A (en) * 1983-09-06 1988-07-12 Kioritz Corporation Centrifugal clutch
US4936271A (en) * 1988-06-10 1990-06-26 Kioritz Corporation Portable powered working machine
US20130180504A1 (en) * 2012-01-13 2013-07-18 Hitachi Koki Co., Ltd. Chainsaw having ventholes for ventilation

Cited By (6)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
US4382333A (en) * 1980-03-31 1983-05-10 Kioritz Corporation Chain saw
US4571833A (en) * 1983-08-30 1986-02-25 Kioritz Corporation Sawdust discharge port
US4756396A (en) * 1983-09-06 1988-07-12 Kioritz Corporation Centrifugal clutch
US4936271A (en) * 1988-06-10 1990-06-26 Kioritz Corporation Portable powered working machine
US20130180504A1 (en) * 2012-01-13 2013-07-18 Hitachi Koki Co., Ltd. Chainsaw having ventholes for ventilation
US9494120B2 (en) * 2012-01-13 2016-11-15 Hitachi Koki Co., Ltd. Chainsaw having ventholes for ventilation

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