JPH0735735U - Internal combustion engine - Google Patents

Abstract

(57) [Summary] [Purpose] The fuel system and intake system devices can be reasonably placed in a place where heat damage from a heating element such as a muffler is less likely to occur, thereby preventing engine malfunction. At the same time, to provide an internal combustion engine which can be constructed at low cost. An engine main body 30 in which a combustion chamber 41 is formed above a cylinder 31, intake side accessory parts 51 and 52 connected to the intake side of the engine main body 30, and an exhaust side of the engine main body 30 are connected. Exhaust side accessory 53,
Crankcase 35 arranged on the side of the cylinder
In the internal combustion engine including the fuel tank 56 and the fuel tank 56, the exhaust side accessory 53 and the intake side accessory 5
1 and 52 are arranged so as to be located on opposite sides to the cylinder 31 of the engine body 30.

Description

[Detailed description of the device]

[0001]

[Industrial applications]

 The present invention relates to an internal combustion engine, and more particularly to an internal combustion engine in which various engine accessories such as a fuel tank, a carburetor, an intake / exhaust device such as an air cleaner and a muffler are installed in an engine body.

[0002]

[Prior art]

 FIG. 2 is a schematic front view schematically showing a small-sized air-cooled two-cycle gasoline engine that is frequently used in a portable work machine as a conventional example of this type of internal combustion engine. In FIG. 2, an internal combustion engine 1 has a fuel tank 2 horizontally mounted on a lower end portion thereof, and a fuel tank 2 vertically arranged integrally above the fuel tank 2 and above a crankcase 4. An engine body 5 having a cylinder 3, a muffler 8 attached to the left and right sides of the engine body 5, an air cleaner and a carburetor 9, and the engine body 5 and the muffler 8, the air cleaner and the carburetor 9, Heat shields 6 and 7 are interposed in the gap with the fuel tank 2.

[0003]

[Problems to be solved by the device]

 In the conventional internal combustion engine as described above, the heat shield plate 7 is provided between the fuel tank 2 which is easily adversely affected by heat and the muffler 8 which is a heating element, but the overall size is made compact. Since they are placed very close to each other for the purpose of summarizing, it is difficult to avoid the influence of heat, and vapor lock occurs due to the vaporization of gasoline in the fuel tank 2, which disturbs the fuel supply action and causes engine malfunction. The problem was that Further, the high temperature exhaust gas discharged from the muffler 8 is sucked by the cooling fan and is recirculated (recirculated) from the suction port on the back side of the crankcase 4, thereby reducing the cooling effect. When gasoline is heated in the carburetor 9 to, for example, 60 ° C or more, a percolation phenomenon occurs in which gasoline is injected into the intake pipe, the air-fuel ratio becomes abnormally rich, idling instability, engine stall, There was a problem that problems such as difficulty in starting occurred.

Further, since the heat shield plates 6 and 7 are provided and the crankcase 4 has a double structure, the number of parts is large and the structure is complicated, so that the cost and space are reduced. Was also a disadvantage. The present invention has been made in view of such a problem, and its purpose is to enable a fuel system and an intake system device to be reasonably arranged in a place where heat damage to a heating element such as a muffler is less likely to occur. Therefore, it is an object of the present invention to provide an internal combustion engine that can prevent the engine from becoming out of order and can be configured at a low cost as a whole.

[0005]

[Means for Solving the Problems]

 In order to achieve the above-mentioned object, an internal combustion engine according to the present invention comprises an engine body having a combustion chamber formed in an upper portion of a cylinder, an intake side accessory connected to the intake side of the engine body, and an engine body of the engine body. In an internal combustion engine equipped with an exhaust side accessory connected to the exhaust side, a crankcase arranged below the cylinder, and a fuel tank, the exhaust side accessory and the intake side accessory are combined. It is characterized in that the fuel tanks are arranged so as to be located on opposite sides of the cylinder of the main body of the engine, and the fuel tank is arranged on the side of the crankcase on the intake side of the engine body. Further, as a more preferable specific example, the cylinder of the engine body is tilted and arranged, and the intake side accessory is arranged between the cylinder and the fuel tank.

[0006]

[Work]

 In the internal combustion engine according to the present invention constructed as described above, since the exhaust side accessory, the intake side accessory and the fuel tank are arranged so as to be separated from each other with the engine body sandwiched therebetween, the high temperature exhaust gas is exhausted. The influence of heat from the side accessories does not reach the fuel tank or the intake side accessories, and it is possible to prevent the engine from malfunctioning as much as possible.

[0007]

【Example】

 An embodiment of the present invention will be described below with reference to the drawings. FIG. 1 is a partially cutaway front view of a four-cycle type small internal combustion engine as one embodiment of the present invention. The illustrated internal combustion engine 10 is composed of an engine main body 30 having a cylinder 31 at the upper portion, and various engine accessories (described later) mounted on the engine main body 30.

The engine body 10 includes a cylinder block 33 having a piston 32 that reciprocates therein, a cylinder head 34 mounted on an upper end of the cylinder block 33, and the cylinder block 33. The crankcase 35 is integrally formed at the lower end, and an oil pan 36 is installed at the bottom of the crankcase 35. A balance weight 38a fixed to the crankshaft 38 is arranged in the crankcase 35 to balance the rotation, and the balance weight 38a is connected to the piston 32 and the piston 32 via a crankpin 38b. It is connected to a large end 39a of a connecting rod 39 which connects the crankshaft 38. A combustion chamber 41 is formed in the cylinder head 34 between an upper inner wall of the cylinder head 34 and an upper surface of the piston 32, and an opening is formed in the combustion chamber 41 to form an intake pipe 42 on the intake side. The exhaust pipes 43 are provided on the respective sides. Further, an intake valve 45 and an exhaust valve 46 are provided at the connecting portions of the combustion chamber 41, the intake pipe 42, and the exhaust pipe 43, respectively. A rocker arm 47, 47, which is rocked at a predetermined timing by a cam shaft (not shown) driven by a gear or the like connected to the crankshaft 38, is opened and closed. In the engine body 10 of this illustrated example, as can be seen from FIG. 1, the cylinder 31 is arranged so as to be inclined.

On the intake side of the combustion chamber 41 of the engine body 10, an intake side accessory such as a diaphragm type carburetor 52 having an air cleaner 51 at its tip is connected to the intake pipe via an insulator 37. A muffler 53, which is an exhaust side accessory, is connected to the exhaust pipe 43 on the exhaust side. The intake side accessory parts 51 and 52 and the muffler 53 are arranged on opposite sides of the cylinder 31 of the engine body 10 with respect to each other.

Further, a fuel tank 56 is erected on the side of the crankcase 35 on the intake side, which is the side opposite to the mounting position of the muffler 53, with respect to the engine body 10. As described above, since the exhaust side accessory 53, the intake side accessories 51 and 52, and the fuel tank 56 are arranged apart from each other with the engine body 30 interposed therebetween, the exhaust side accessory The influence of heat generated by the component 53 does not extend to the fuel tank 56 or the intake side accessory components 51 and 52, and the occurrence of percolation, vapor lock, etc. is suppressed, and therefore the engine malfunction can be prevented. Wear. Further, by making the cylinder 31 inclined and accommodating the intake side accessory part in the space between the fuel tank 56 and the fuel tank 56, the overall structure can be made compact.

Although one embodiment of the present invention has been described in detail above, the present invention is not limited to the above-mentioned embodiment, and does not deviate from the present invention described in the scope of claims for utility model registration. Various design changes can be made. For example, in order to further improve the heat-shielding effect, a heat-shielding plate may be appropriately provided if necessary, and it may be applied to a two-cycle engine.

[0012]

[Effect of device]

 As can be understood from the above description, the fuel system and the intake system device can be reasonably arranged in a place where heat damage from a heating element such as a muffler is less likely to occur, thereby preventing the engine from malfunctioning. In addition to preventing it, the whole structure can be constructed at low cost.

[Brief description of drawings]

FIG. 1 is a partially cutaway front view of an internal combustion engine according to an embodiment of the present invention.

FIG. 2 is a schematic front view schematically showing an example of a conventional internal combustion engine.

[Explanation of symbols]

 30 Engine Main Body 31 Cylinder 35 Crankcase 41 Combustion Chamber 51 Intake Side Attachment (Air Cleaner) 52 Intake Side Attachment (Carburetor) 53 Exhaust Side Attachment (Muffler) 56 Fuel Tank

Claims (2)

[Scope of utility model registration request] 1. An engine body 30 having a combustion chamber 41 formed in an upper portion of a cylinder 31, intake side accessories 51 and 52 connected to an intake side of the engine body 30, and an exhaust side of the engine body 30. Connected exhaust side accessories 53
In the internal combustion engine including: a crankcase 35 disposed below the cylinder 31; and a fuel tank 56, the exhaust side accessory 53 and the intake side accessory 51, 5
2 and 2 are arranged so as to be located on opposite sides to the cylinder 31 of the engine body 30, and the fuel tank 56 is arranged on the side of the crankcase 35 on the intake side of the engine body 30. Characteristic internal combustion engine. 2. The cylinder 3 of the engine body 30.
1 is arranged so as to be inclined, and the intake side accessory parts 51, 52 are provided between the cylinder 31 and the fuel tank 56.
The internal combustion engine according to claim 1, wherein the internal combustion engine is arranged.