JPH0481554A - Lower crankcase for vertical industrial engine - Google Patents

Abstract

PURPOSE:To make lubricating oil drawn out of an oil suction port so as not to get an air bubble mixed in as well as to lubricate every sliding part of an engine so smoothly and maintain a stable function by installing the oil suction port and a governor gear at the opposite side each in bordering a rid provided with an oil passage. CONSTITUTION:An oil suction port 6 and a governor gear 3 are installed at the opposite side each in bordering a rid 7 provided with an oil passage. With this formation, when a lower crankcase 30 is tilted, lubricating oil 12 staying in the lower crankcase 30 is stirred by the governor gear 3, and even in the case where an air bubble 20 is formed in an inner part of the lubricating oil 12, the lubricating oil 12 inclusive of the air bubble 20 is hindered by the rid 7 provided with the oil passage, whereby its movement to the side of an oil inlet 5 is checked as far as practicable, therefore the air bubble 20 comes to be prevented from mixing in the lubricating oil 12 drawn out of the oil suction port 5 in consequence.

Description

[Detailed Description of the Invention] [Field of Industrial Application] The present invention relates to a vertically mounted general-purpose engine used in lawn mowers, etc., in which the crankshaft is arranged vertically, and in particular to a lubrication engine for this engine. This article relates to the structure of a lower crankcase that temporarily retains oil.

[Conventional technology]

FIG. 4 is a top view showing a conventional lower crankcase 1 of a vertically mounted general-purpose engine.

At the bottom 1a of the lower crankcase 1, in addition to a journal 2 that supports a crankshaft (not shown), a governor gear 3 that adjusts the engine speed, an oil pump 4,
Members such as an oil strainer 5 and an oil suction port 6 that sucks lubricating oil and supplies it to various parts of the engine are provided or formed therein.

Of these, the oil suction port 6 is formed in the bottom portion 1a of the lower crankcase 1 at a position close to the governor gear 3.

In FIG. 4, reference numeral 7 denotes a rib in which an oil passage (described later) for supplying lubricating oil to the journal 2 is formed.

The oil strainer 5 is disposed across the ends of the ribs 8.9 extending from both ends of the above-mentioned rib 7, and the oil strainer 5 is disposed between the ends of the ribs 8.9 and The area surrounded by 5 is a plate which will be described later, and its upper surface is eventually covered. In FIG. 4, reference numeral 10 denotes a boss portion in which a female threaded portion 10a of a bolt (to be described later) for fixing the above-mentioned plate is formed, and 11 denotes a rib 7.
This is a relief valve for the oil passage formed inside.

On the other hand, in the bottom part 1a of the lower crankcase 1 mentioned above,
As shown in Fig. 5, which is an enlarged sectional view taken along the line AA in Fig. 4, lubricating oil [2], which is normally pumped to various parts of the engine, remains.
This lubricating oil 12 is sucked in as shown by the arrow through the oil suction port 6 as shown in FIG. 5 by the suction force of the oil pump 4 shown in FIG. Ru.

In addition, in FIG. 5, the reference numeral 13 denotes a plate that covers the area surrounded by the above-mentioned ribs 7, 8, and 9 and the oil strainer 5.
14 is a bolt for fastening the plate 13, and 15 and 16 are oil passages formed in the rib 7.

[Problems to be Solved by the Invention] By the way, the vertical general-purpose engine having the above-mentioned lower crankcase 1 is used, for example, in a lawn mower. As shown in FIG. 6, the lower crankcase 1 may be tilted by an angle of θ centered on the governor gear 3 side.

When the lower crankcase 1 is tilted by θ with the governor gear 3 side as the center, the oil level of the lubricating oil 12 staying inside moves toward the governor gear 3 side as shown in the figure, so the lubricating oil 12 is agitated by the governor gear 3. , a large number of bubbles 20 are formed inside the bubble. When such air bubbles 20 enter the lubricating oil 12, the air bubbles 20 move to the oil suction port 6 side through the strainer 5, and the lubricating oil 1
2 and air bubbles 20 are sucked in as shown by the arrows through the oil suction port 6 and are forced into the sliding parts of the various parts of the engine, which has the disadvantage of causing damage such as seizure to the sliding parts of each engine.

In view of the above-mentioned circumstances, the present invention is designed to prevent the air bubbles from being forced into the sliding parts of the engine even if the lower crankcase is tilted and air bubbles are formed in the lubricating oil by the governor gear. The purpose of the present invention is to provide a lower crankcase for a vertically mounted general-purpose engine.

[Means to solve the problem]

In order to solve the above-mentioned problems, the present invention includes at least a governor gear that adjusts the rotation speed of the engine, an oil suction port that sucks the lubricating oil that remains and supplies it to each part of the engine, and a rib in which an oil passage is formed. In a lower crankcase of a vertically mounted general-purpose engine located at the bottom, the oil suction port and the governor gear are arranged on opposite sides of a rib in which the oil passage is formed.

[Effect]

According to the lower crankcase of the vertical general-purpose engine described above, since the oil suction port and the governor gear are arranged on opposite sides of the rib in which the oil passage is formed, the lower crankcase When the lower crankcase is tilted, the lubricating oil remaining in the lower crankcase is stirred by the governor gear, and even if air bubbles are formed inside the lubricating oil, the lubricating oil containing the air bubbles will form an oil passage. The ribs become a hindrance and prevent the lubricant from moving toward the oil suction port as much as possible, thereby preventing air bubbles from being mixed into the lubricating oil sucked from the oil suction port.

〔Example〕

Hereinafter, one embodiment of the lower crankcase of a vertically mounted general-purpose engine according to the present invention will be described in detail.

FIG. 1 is a top view showing a lower crankcase 30 of a vertically mounted general-purpose engine according to the present invention, and the same parts as in FIGS. 4 to 6 are designated by the same reference numerals.

In addition to the journal 2 that supports the crankshaft (not shown), the bottom part 30a of the lower crankcase 30 includes a governor gear 3 that adjusts the engine speed, an oil pump 4, an oil strainer 5, and a lubricating oil that sucks the engine. A member such as an oil suction eye 6 for supplying oil to each part is provided or formed there.

Of these, the oil suction port 6 and the governor gear 3 are disposed on opposite sides of a rib 7 in which an oil passage is formed. The oil suction port 6 is formed on the opposite side of the governor gear 3 with the rib 7 as a boundary, and is formed as close to the center of the crankcase 30 as possible.

In addition, as shown in the figure, ribs 8 extending from both ends of the rib 7
．． 9 is also formed on the side opposite to the governor gear 3 with the rib 7 in which the oil passage is formed as a border, and this rib 7.8
．． A region surrounded by the oil strainer 9 and the oil strainer 5 is also disposed on the opposite side from the governor gear 3 with the rib 7 in which the oil passage is formed as a boundary.

On the other hand, as shown in FIG. 2, which is an enlarged cross-sectional view of BB in FIG. The oil 12 is sucked in as shown by the arrows through the oil suction port 6 by the suction force of the oil pump 4 shown in FIG.

Next, the operation of the above-mentioned lower crankcase 30 will be explained.

The vertical general-purpose engine having the lower crankcase 30 described above is used, for example, in a lawn mower, so if the lawn mower is to be driven on an inclined slope, the 0-ac crank case is used as shown in Fig. 3. 30 may be inclined by θ centering on the governor gear 3 side.

When the lower crankcase 30 or the governor gear 3 side is tilted by θ in this way, the oil surface of the lubricant oil 2 retained inside moves toward the governor gear 3 side, so that the lubricant oil 12 is agitated by the governor gear 3, and Many bubbles 20 inside
or is formed.

However, the lower crankcase 30 described above,
A rib 7 in which an oil passage is formed stands between the oil suction port 6 and the governor gear 3, and the oil suction port 6 and the governor gear 3 are separated from each other by the rib 7 in which the oil passage is formed. Since it is disposed on the opposite side, when the lower crankcase 30 is tilted, the lubricating oil 12 remaining in the lower crankcase 30 is transferred to the governor gear 3.
Even if air bubbles 20 are formed inside the lubricating oil 12, the lubricating oil 12 containing the air bubbles 20 will be obstructed by the ribs 7 in which the oil passages are formed, and as shown in FIG. The lubricating oil 12' staying in the vicinity of the oil suction port 6 is prevented from being mixed with air bubbles 20 because the lubricating oil 12' is prevented from moving toward the suction port 6 side as much as possible.

Therefore, due to the suction force of the oil pump 4 shown in FIG. 1, the lubricating oil 12'', which does not contain air bubbles 20 and remains near the oil suction port 6, flows through the oil suction port 6 as shown by the arrow as shown in FIG. It is sucked in and forced to be sent to each sliding part of the engine, including the journal 2, to smoothly lubricate each sliding part.

Note that, as shown in FIG. 1, the oil suction port 6 is formed on the opposite side of the governor gear 3 with the rib 7 as a boundary, and is located as close to the center of the lower crankcase 30 as possible. Even if the lower crankcase 30 is tilted, the oil suction port 6 is prevented from coming out onto the surface of the lubricating oil 12, and as a result, the engine is prevented from becoming unlubricated. be prevented.

〔Effect of the invention〕

As explained above, in the lower crankcase of the vertically mounted general-purpose engine according to the present invention, the oil suction port and the governor gear are arranged on opposite sides of the rib formed in the oil passage. Therefore, even if the lubricating oil remaining in the lower crankcase is stirred by the governor gear and air bubbles are formed inside the lower crankcase when the lower crankcase is tilted, the lubricating oil containing the air bubbles will flow into the oil passage. The ribs formed thereon act as obstacles and prevent the lubricating oil from moving toward the oil suction port as much as possible, so air bubbles do not get mixed in with the lubricating oil sucked from the oil suction port. It is possible to provide a vertically mounted general-purpose engine that smoothly lubricates each sliding part without causing damage such as seizure to each sliding part and maintains stable function.

[Brief explanation of the drawing]

Fig. 1 is a top view of the lower crankcase of a vertically mounted general-purpose engine according to the present invention, and Figs. 2 and 3 are B of Fig. 1.
FIG. 4 is a top view of a conventional lower crankcase of a vertically installed general-purpose engine, and FIGS. 5 and 6 are enlarged AA sectional views of FIG. 1. 3... Governor gear, 6... Oil suction port, 7...
Rib in which an oil passage is formed, 30...lower crankcase, 30a...bottom.

Claims (1)

[Scope of Claims] A vertical general-purpose vehicle having at least a governor gear that adjusts the rotational speed of the engine, an oil suction port that sucks the lubricating oil that remains and supplies it to each part of the engine, and a rib in which an oil passage is formed at the bottom. A lower crankcase of a vertical general-purpose engine, characterized in that, in the lower crankcase of the engine, the oil suction port and the governor gear are arranged on opposite sides of a rib in which the oil passage is formed. Crankcase.