JP4532032B2 - Forced air cooling engine - Google Patents

Description

[0001]
BACKGROUND OF THE INVENTION
The present invention relates to a forced air cooling engine in which measures for preventing freezing of a carburetor are taken.
[0002]
[Prior art]
The carburetor attached to the engine is a device that converts liquid fuel into gaseous fuel on the principle of spraying, and during this conversion, the gaseous fuel takes away ambient heat, so the carburetor is cooler than other devices.
When the engine is operated in a cold region, the carburetor may become below freezing and freeze. This phenomenon is called icing, and anti-freezing measures are essential to maintain stable operation.
[0003]
For example, Japanese Utility Model Publication No. 51-122219, “Engine”, as shown in FIGS. 1 and 2 of the same publication, warms the air pressurized by the fan 3 provided on the crankshaft 2 with the muffler 11, The obtained hot air is sent to the vaporizer 7 to prevent freezing. According to FIG. 1, after warming the carburetor 7, the hot air reaches the air cleaner 9 and becomes part of the combustion air of the engine.
[0004]
[Problems to be solved by the invention]
As is well known, when the engine output changes, the amount and temperature of the exhaust gas change. Specifically, when the output is high, the amount of exhaust gas is large and the exhaust gas temperature is high. Conversely, when the output is low, the amount of exhaust gas is small and the exhaust gas temperature is low. On the other hand, since the muffler is composed of a thin pipe or a thin plate, the heat capacity is small.
If the heat capacity is large, the muffler temperature will not change suddenly even if the exhaust gas temperature or quantity changes, but as mentioned above, the muffler has a small heat capacity. Go up and down.
[0005]
If the temperature of the muffler is low, the temperature of the hot air obtained is also low, the antifreezing action becomes insufficient, and freezing trouble occurs.
In addition, when the hot air reaches the air cleaner after warming the vaporizer, if the temperature of the hot air changes with the temperature change of the muffler, the temperature of the air at the inlet of the vaporizer directly changes. The mixing ratio (air / fuel) changes and appears as a carburetor setting failure.
[0006]
That is, if hot air warmed by the heat of the muffler is used to prevent freezing, there is a risk of inadequate countermeasures for freezing and poor setting of the vaporizer.
Accordingly, an object of the present invention is to provide a technique capable of sufficiently exhibiting countermeasures for freezing and capable of maintaining a good vaporizer setting.
[0009]
[Means for Solving the Problems]
To achieve the above object, the present invention is provided with a fan at one end of a crank shaft disposed horizontally, inclined cylinder cylinder axis extending from said crankshaft was positioned between the horizontal line and the vertical line according to claim 1 the provided, and along the air guide which also serves as a cover to the lower half among the outer periphery of the inclined cylinder, the carburetor is disposed on the side of the fan side of the inclined cylinder, placing the air cleaner above the vaporizer to direct the pressurized air in the fan to the tilt cylinder periphery, in the forced air-cooled engine of the type forced cooling the tilt cylinder through between the air guide and the tilt cylinder, and cooling said tilt cylinder the exhaust air after the first exhaust air guide for guiding the vicinity of the evaporator through the lower of the air guide after a U-turn, when attached to the inclined cylinder around To guide the exhaust air to subsequent to the first exhaust air guide to the vaporizer, the second exhaust air guide to turn leads to the air cleaner, to open the bottom surrounds the lower space of the air cleaner including the vaporizer It is characterized by being attached as follows .
[0010]
The air pressurized by the fan is guided to the cylinder periphery to force the cylinder. The exhaust air that has absorbed the heat of the cylinder is returned to the position closer to the fan than the cylinder through the first exhaust guide and under the cylinder and the air guide. The second wind guide that is wound around the air cleaner in a skirt shape includes an inlet of the air cleaner and a carburetor below the inside, and since it is a skirt, the lower portion is in an open state.
If the exhaust air from the first exhaust guide is guided to such a second exhaust guide, the carburetor can be sufficiently warmed by the exhaust air flowing through the second exhaust guide.
[0011]
As described above, since the temperature of the exhaust air that receives heat from the cylinder whose temperature change is slow is substantially constant, it is possible to prevent the carburetor from freezing stably and supply the exhaust air with little temperature change to the air cleaner. Therefore, the mixing ratio in the vaporizer can be stabilized.
[0012]
When an engine is mounted on a snowplow or the like, snow or ice may be mixed with air pressurized by a fan. These snow and ice ride on air and exhaust wind and reach the vicinity of the vaporizer through the first exhaust guide and the second exhaust guide. However, in the present invention, the second wind guide is formed in a skirt shape so that the lower part is open, and the snow and ice fall downward without facing the vaporizer. Therefore, the engine of the present invention is suitable for snow or ice work vehicles such as snowplows and snow vehicles.
[0013]
DETAILED DESCRIPTION OF THE INVENTION
Embodiments of the present invention will be described below with reference to the accompanying drawings. The drawings are viewed in the direction of the reference numerals.
FIG. 1 is a side view of a basic engine employed in the present invention, and FIG. 2 is a front view thereof. Before explaining the forced air-cooled engine with anti-freezing measures according to the present invention, a general-purpose engine without anti-freezing measures is basic. This is called engine 10 and will be described first.
[0014]
In FIG. 1, a basic engine 10 includes a crankcase 11, a cylinder 12 with air cooling fins (see FIG. 2), an air guide 13 extending along the lower half of the cylinder 12, a cylinder head 14, and a fan 15. This is a general-purpose forced air-cooled engine including a case 16, a cover 17 incorporating a recoil starter, a start grip 18, an air cleaner 19, an electrical board 21, a carburetor 22, a muffler 23, and a fuel tank 24.
[0015]
When the engine is started, the fan 15 rotating together with the crankshaft 25 causes the air to reach the fan case 16 as indicated by the arrow (1), and the air pressurized by the fan 15 strikes the cylinder 12 and the arrow (2). , Divide up and down as indicated by (3) and exit as indicated by arrows (4) and (4). The flow of arrows (2) and (3) will also be described in the next figure.
[0016]
In FIG. 2, a cylinder 12 with air-cooling fins is an inclined cylinder in which a cylinder shaft 27 extending from a crankshaft 25 is inclined at an angle θ (eg, θ = 25 °) with respect to a horizontal line 28. The air guide 13 is shown along the lower half of the outer periphery. As shown in the cross-sectional view shown in the lower right of the figure, the air guide 13 is a guide plate that is aligned with the cylinder 12 while maintaining an appropriate gap.
Thus, air flows from the back of the drawing to the front of the drawing (2) above the cylinder 12 and the bottom (3) of the cylinder 12 to forcibly cool the cylinder 12.
[0017]
Note that there are a fuel tank 24 and a muffler 23 above the cylinder 12, and these substantially serve as an air guide and cover. Therefore, no air guide is provided above the cylinder 12. On the other hand, since the lower part of the cylinder 12 faces the outside, a safety cover is necessary, and an air guide 13 that also serves as a safety cover is provided.
[0018]
FIG. 3 is a configuration diagram and a mounting diagram of the first exhaust guide according to the present invention. As shown in the perspective view below the drawing, the first exhaust guide 30 includes a cylinder side portion 31 that is divided for convenience, It consists of a cylinder head cover part 41, both of which are metal bent members.
Specifically, the cylinder side portion 31 includes an upper surface portion 32, a left side surface portion 33, a flange portion 34, and an arm portion 35.
The cylinder head cover part 41 includes a left side part 42, a front part 43, a bottom part 44, and a flange part 45.
[0019]
Then, in the above figure, the cylinder side portion 31 is placed in front of the cylinder 12 and fixed to the crankcase 11 with bolts 46, 47 and the like. Next, the cylinder head 14 is surrounded by the cylinder head cover portion 41, and the cylinder head cover portion 41 is fixed to the cylinder side portion 31 with bolts 48 and 49.
[0020]
FIG. 4 is a configuration diagram and a mounting diagram of the second exhaust guide according to the present invention, and the procedure for attaching the second exhaust guide 50 after the first exhaust guide 30 is attached to the basic engine 10 will be described.
As shown in the perspective view at the bottom of the figure, the second wind guide 50 is composed of a front part 51 and a right side part 52, and is a simple member that is simply bent in an L shape in plan view. It is a flexible rubber plate. 53 is a door for operating switches.
The second wind guide 50 is wound around the lower edge of the air cleaner 19 in a skirt shape and fixed with bolts 54, 55, 56, and the like.
[0021]
FIG. 5 is an installation view of the second exhaust guide according to the present invention, and is a second exhaust guide 50 comprising a front portion 51 and a right side portion 52, and a carburetor disposed below the air cleaner 19 and below the air cleaner 19. It shows that 22 is enclosed.
[0022]
Returning to FIG. 4, the basic engine 10 described in FIGS. 1 and 2 is provided with the first and second exhaust guides 30 and 50. The forced air cooling engine of the present invention (forced cooling engine with antifreezing measures). 60.
[0023]
Next, the operation of the first and second exhaust guides 30 and 50 having the above-described configuration will be described.
FIG. 6 is a diagram for explaining the operation of the first and second exhaust guides according to the present invention. Exhaust air indicated by arrows (4) and (4) (see FIG. 1) is dammed by the left side surfaces 33 and, and is U-turned. (Arrow {circle over (5)}) then flows as indicated by arrow {circle around (6)} along the bottom 44 and the front portion not shown. That is, the exhaust air passes under the cylinder after making a U-turn.
The above is the operation of the first exhaust guide 30.
[0024]
Next, the exhaust air indicated by the arrow (7) warms the carburetor 22 in the process of rising in the second exhaust guide 50, then reaches the lower surface of the air cleaner 19 and enters the air cleaner 19 as indicated by the arrow (8).
[0025]
FIG. 7 is a forced air cooling system diagram of the forced air cooling engine of the present invention. The operation of FIGS. 1, 2 and 6 is summarized and the principle is illustrated, and a fan 15 provided at one end of the crankshaft 25 is illustrated. Suction (arrow (1)), pressurized air is allowed to flow around the cylinder 12 of the engine as indicated by arrows (2) and (3) to forcibly cool the cylinder 12, and the exhaust air that has absorbed the heat is indicated by arrow (4). , (5), (6) and (7) lead to the vaporizer 22 to warm the vaporizer 22, thereby preventing the vaporizer 22 from freezing.
[0026]
Since the cylinder 12 of the engine is generally a metal casting and has a large heat capacity, the temperature change becomes slow. That is, even if the amount and temperature of the exhaust gas change suddenly as the engine output changes, the temperature of the cylinder 12 changes gradually. As a result, hot air having a predetermined temperature or higher can be obtained, and this hot air can be applied to the carburetor 22, so that the carburetor 22 can be prevented from freezing without being affected by the output of the engine.
[0027]
In order to realize such an air and exhaust flow, the cylinder 12 and the air guide 13 are surrounded by the first exhaust guide 30 and the space below the air cleaner 19 including the carburetor 22 is surrounded by the second exhaust guide 50. Is a structural feature.
[0028]
That is, the exhaust air that has absorbed the heat of the cylinder 12 is returned to the position closer to the fan 15 than the cylinder 12 through the first exhaust air guide 30 under the cylinder 12 and the air guide 13. The second wind guide 50 wound in a skirt around the air cleaner 19 includes an inlet of the air cleaner 19 and a vaporizer 22 below the inlet.
If the exhaust air from the first exhaust guide 30 is guided to the second exhaust guide 50, the carburetor 22 can be sufficiently warmed by the exhaust air flowing through the second exhaust guide 50.
[0029]
As described above, since the temperature of the exhaust air that receives heat from the cylinder 12 whose temperature change is slow is substantially constant, the carburetor 22 can be prevented from freezing stably, and the exhaust air with little temperature change can be removed from the air cleaner 19. Therefore, the mixing ratio in the vaporizer 22 can be stabilized.
[0030]
When an engine is mounted on a snowplow or the like, snow or ice may be mixed with air pressurized by a fan. These snow and ice ride on air and exhaust wind and reach the vicinity of the vaporizer through the first exhaust guide and the second exhaust guide. However, in the present invention, the second wind guide is formed in a skirt shape so that the lower part is opened, and the snow and ice fall downward without going to the vaporizer (arrow (9)). A specific example will be described next.
[0031]
FIG. 8 is a side view of a snowplow equipped with the forced air cooling engine of the present invention. The snowplow 70 has an auger that collects snow at the front of a machine body 74 having drive wheels 71, driven wheels 72 and crawlers 73. 75, an auger housing 76 that surrounds the auger 75, a fan 77 that blows up the collected snow upward, a fan housing 78 that surrounds the fan 77, and a chute 79 that guides the snow that has been blown up. This is a walking type snow remover that includes the forced air cooling engine 60 of the present invention, extends an operation handle 81 from the rear part of the machine body 74, and an operator takes with the machine body 74 while holding the operation handle 81.
[0032]
Since the forced air cooling engine 60 is a freezing countermeasure engine having the first and second exhaust air guides 30 and 50, there is no fear that the carburetor freezes even if snow removal work is performed on a low temperature snow road. Even if a part of the snow or ice discharged by the chute 79 or a part of the snow from the blizzard rides on the air indicated by the arrow (1) shown in FIG. As described above, it falls from the lower part of the second exhaust air guide 50, so there is no problem.
[0033]
Therefore, the forced air cooling engine 60 of the present invention is suitable for a snow or ice work vehicle such as a snowplow or a snow vehicle. However, since the forced air cooling engine 60 of the present invention can be used for other purposes, the application is not particularly limited.
[0034]
In the present embodiment, the first exhaust air guide 30 has a two-part structure, but it may have a non-partition structure. Moreover, if the attachment / detachment is possible, the first and second wind guides 30 and 50 may be integrated. Furthermore, the number and arrangement of bolts for fixing the first and second wind guides 30 and 50 are arbitrary.
[0036]
【The invention's effect】
The present invention exhibits the following effects by the above configuration.
In the invention which concerns on Claim 1, the air pressurized with the fan is guide | induced to the cylinder outer periphery, and a cylinder is forced-air-cooled. The exhaust air that has absorbed the heat of the cylinder is returned to the position closer to the fan than the cylinder through the first exhaust guide and under the cylinder and the air guide . The second exhaust guide includes an air cleaner inlet and a vaporizer below the second exhaust guide, and the lower part is open.
If the exhaust air from the first exhaust guide is guided to such a second exhaust guide, the carburetor can be sufficiently warmed by the exhaust air flowing through the second exhaust guide.
[0037]
As described above, since the temperature of the exhaust air that receives heat from the cylinder whose temperature change is slow is substantially constant, it is possible to prevent the carburetor from freezing stably and supply the exhaust air with little temperature change to the air cleaner. Therefore, the mixing ratio in the vaporizer can be stabilized.
[0038]
When an engine is mounted on a snowplow or the like, snow or ice may be mixed with air pressurized by a fan. These snow and ice ride on air and exhaust wind and reach the vicinity of the vaporizer through the first exhaust guide and the second exhaust guide. However, the present invention is open in the bottom of the second exhaust air guide, snow and ice without directing the carburetor, can fall downwards.
[Brief description of the drawings]
FIG. 1 is a side view of a basic engine employed in the present invention. FIG. 2 is a front view of the basic engine employed in the present invention. FIG. 3 is a configuration diagram and mounting diagram of a first exhaust guide according to the present invention. FIG. 5 is a view showing the construction and mounting of the second exhaust guide according to the present invention. FIG. 5 is an installation view of the second exhaust guide according to the present invention. FIG. 7 is a forced air cooling system diagram of the forced air cooling engine of the present invention. FIG. 8 is a side view of a snowplow equipped with the forced air cooling engine of the present invention.
DESCRIPTION OF SYMBOLS 10 ... Basic engine, 12 ... Cylinder, 13 ... Air guide, 15 ... Fan, 19 ... Air cleaner, 22 ... Vaporizer, 25 ... Crankshaft, 27 ... Cylinder shaft, 28 ... Horizontal axis, 30 ... 1st exhaust guide 50 ... second wind guide, 60 ... forced air cooling engine of the present invention, 70 ... snow remover, .theta .... inclination angle of cylinder axis with respect to horizontal axis.

Claims (1)

Comprising a fan at one end of a crank shaft disposed horizontally, an inclined cylinder is positioned between the cylinder axis and horizontal and vertical line extending from the crank shaft, the cover down half among the outer periphery of the inclined cylinder and along the air guide which also serves as the laterally of the fan side of the inclined cylinder arranged carburetor, an air cleaner is disposed above the carburetor, lead pressurized air by the fan to the inclined cylinder periphery , in the forced air-cooled engine of the type forced cooling the tilt cylinder through between the air guide and the tilt cylinder,
A first exhaust guide that guides the exhausted air after cooling the inclined cylinder to the vicinity of the carburetor through a U-turn after the U-turn is provided around the inclined cylinder. subsequently the wind guide guides the exhaust air to the carburetor, the second exhaust air guide to turn leads to the air cleaner, that it has attached so as to open the bottom surrounds the lower space of the air cleaner including the vaporizer The featured forced air cooling engine.

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