JPH0618012Y2 - Cylinder body oil return structure - Google Patents

Description

[Detailed Description of the Invention] [Industrial field of application] The present invention is a cylinder body that quickly returns oil after lubricating and cooling cams, rocker arms, push rods, etc. in the cylinder head to the crankcase again. Oil return structure.

[Prior Art] The oil stored in the crankcase is supplied to the cam mechanism, the rocker arm mechanism, and the tappet mechanism in the cylinder head in order to ensure stable operation of these mechanisms. Further, in recent years, the oil in the crankcase is pumped out by a pump, and the pumped oil is sent to a series of supply passages that pass through the mutual contact portions of the push rod, rocker arm, and camshaft, and forced lubrication and Lubricating device for cooling valve train for internal combustion engine (Shokai 57-126514
No. publication) is known.

By the way, in order to return the oil after lubrication / cooling of each part (cam mechanism, rocker arm mechanism, tappet mechanism) to the crankcase, conventionally, an oil return passage as shown in FIGS. 3 and 4 is formed in the cylinder body. Was.

As shown in the figure, the cylinders of the cylinder body a are arranged in V-shape in two parallel rows, and the leg portions b orthogonal to the row direction of the cylinder body a are arranged along the gravity direction of the cylinder body a. In addition, an oil return passage d is formed on the side portion b thereof at a predetermined interval in the column direction of the cylinder c. An opening end d ₁ of each oil return passage d on the cylinder head (not shown) side is opened to an upper end surface a ₁ that is a base of the cylinder body a, and the other end is on a balancer rotation orbit of the crankshaft e or It was opened so as to face the inside of the crankcase below the rotating orbit.

[Problems to be solved by the invention] However, as described above, it is necessary to allow the oil from the cylinder head to move in the direction of centrifugal force by the crankshaft, the balancer, or the like, so that the opening end of the oil return passage faces the balancer rotation path. The problem that it is scattered to occurs. On the other hand, exposing the opening end downward on the balancer rotation orbit can solve the above problem, but due to the wall thickness of the cylinder body and crankcase, it is raised in the width direction with respect to the side. Therefore, the oil return passage must be formed. This is a problem in terms of weight and cost. Further, the fact that the oil cannot be properly returned into the crankcase remains as a problem to be solved because it is not possible to satisfactorily know the remaining amount of the oil stored in the crankcase.

[Means for Solving Problems] The present invention aims to solve the above problems. In this invention, the cylinder body is formed by offsetting the cylinder at a portion on one end side in the longitudinal direction of the cylinder body, and opening the same at the other end portion of the cylinder body to the bearing portion side of the cylinder body. An oil return passage that extends and opens to the outside is formed at a portion immediately above the bearing portion, and a passage connected to the oil chamber of the crankcase is connected to the opening of the oil return passage on the bearing portion side.

[Operation] Regardless of whether a single cylinder or a plurality of cylinders are formed in the cylinder body, the one end of the cylinder body is offset to form the oil return passage with the other end facing the oil chamber in the crankcase. Can be formed. By connecting a passage connected to the oil chamber of the crankcase to the opening of the oil return passage on the bearing side, the oil can be returned to the oil chamber while avoiding the balancer of the crankshaft. Therefore, the oil can be quickly returned to the oil chamber without changing the shape of the cylinder body or increasing the weight.

[Embodiment] A preferred embodiment of the oil return structure for a cylinder body of the present invention will be described below with reference to the accompanying drawings.

A cylinder body 1 shown in FIG. 1 has a plurality of cylinders 2 formed therein. The cylinders 2 are formed at a predetermined interval in the longitudinal direction of the cylinder body 1. In this embodiment, the cylinders 2 are formed.
Are arranged in parallel in two rows to form a V-shaped multi-cylinder cylinder body 1.

Further, in order to return the oil used for lubrication / cooling in the cylinder head (not shown) to the oil chamber 4 of the crankcase portion 3 again, the cylinder body 1 is configured as follows.

One of the cylinder rows 3a of the cylinder body 1 is moved toward one end side (= offset) in the longitudinal direction of the cylinder body 1 and the other cylinder row 3b is moved toward the other end side (here, each cylinder row 3a). , 3b, the pitch between cylinders cannot be changed. Oil return passages 4a and 4b are formed at the other end of one cylinder row 3a and at one end of the other cylinder row 3a, respectively. Each of the return passages 4a and 4b is opened at the upper end of the cylinder body 1 and the other end is formed at the other end like the cylinders.
The cylinder body 1 is opened to the side surfaces 5a and 5b on one end side or the other end side through the direction of gravity inside. The open ends 6 and 7 of the side surfaces 5a and 5b are formed so as to be positioned directly above the bearing portion 9 of the cylinder body 1 as shown in FIG. 2, and directly face the oil chamber 4 of the crankcase (not shown). The oil chamber 4 is connected to the passage 10 which has been removed, or a pipe such as a hose.

Next, the operation will be described.

Oil after lubricating / cooling the drive elements (neither shown) such as the cam mechanism, tappet mechanism, push rod mechanism, etc. in the cylinder head (not shown) is the oil return passage (Fig. Through the oil return passages 4a, 4b in the cylinder body 1 through the crankcase portion 8 without any obstruction.
It is returned to the oil chamber 9 inside. As a result, the returned oil is not attached to the crankshaft or the counter balancer and is not scattered by the crankshaft or the counter balancer, so that the oil can be smoothly circulated. As a result, the reliability of the oil storage amount measurement becomes high.

[Effect of the Invention] As is clear from the above description, the oil return structure of the cylinder body of the present invention can exert the following excellent effects.

The cylinder body is formed by offsetting the cylinder at a portion on one end side in the longitudinal direction of the cylinder body, and is opened at a portion on the other end side of the cylinder body to extend toward the bearing portion side of the cylinder body and the bearing portion thereof. An oil return passage that opens to the outside is formed immediately above, and the passage that connects to the oil chamber of the crankcase is connected to the opening on the bearing side of the oil return passage. Oil can be returned to the oil chamber without interruption.

BRIEF DESCRIPTION OF THE DRAWINGS FIG. 1 is a plan view showing a preferred embodiment of an oil return structure for a cylinder body of the present invention, and FIG. 2 is a II-I in FIG.
A sectional view taken along the line I, and FIG. 3 is a plan view of a conventional cylinder body,
FIG. 4 is a sectional view taken along line IV-IV in FIG. In the figure, 1 is a cylinder body, 2 is a cylinder, 3a and 3b.
Are cylinder rows, and 4a and 4b are oil return passages.

Claims (1)

[Scope of utility model registration request] 1. A cylinder body is formed by offsetting a cylinder at a portion on one end side in the longitudinal direction of the body, and is opened at a portion on the other end side of the cylinder body toward the bearing portion side of the cylinder body. An oil return passage extending outward and opening to the outside is formed at a portion directly above the bearing portion, and a passage connected to the oil chamber of the crankcase is connected to the opening on the bearing portion side of the oil return passage. Cylinder body oil return structure.