JPH068277Y2 - Engine case - Google Patents

Description

DETAILED DESCRIPTION OF THE INVENTION (Industrial field of application) The present invention relates to an engine case, and more particularly to an engine case having a flow path for allowing oil in a mission chamber to flow out of the engine.

(Problems to be solved by the conventional technology and device) As shown in FIG. 8, in the engine case, the wall (124a) facing the mission chamber (131) has an opening toward the mission chamber (131) side. A flow path (175) having a portion (175a) is formed so that oil scraped up by the transmission gears (155), (156) is allowed to flow out of the engine case (124) through this flow path (175). There is.

Conventionally, in order to form this flow path in the engine case, as shown in FIG. 9, a bulging portion (180) having a substantially circular cross section and linearly extending is formed in a wall portion (124a) of the engine case (124). The bulging portion (180a) is formed in advance by forming a hole (180a) along the axial center of the bulging portion (180) with a drill in the bulging portion (180) as shown in FIG. ) Is formed into a hollow shape such as a cylinder, and finally the first
As shown in FIG. 1, the opening (175a) is formed by cutting the bulging portion (180) on the mission chamber (131) side with a cutting tool or the like.

As described above, conventionally, the engine case has to be processed twice or more in order to form the flow path in the engine case. Therefore, the processing is troublesome and the processing time is long.

The present invention has been made in view of such conventional circumstances, and an object thereof is to provide an engine case capable of forming a flow path by one-time processing.

(Means for Solving the Problems) In order to achieve the above-mentioned object, the present invention provides a thick chamber that forms a mission chamber in an engine case and linearly extends to a wall portion of the engine case facing the mission chamber. In an engine case in which a bulged portion is formed, and a flow path is formed in the bulged portion in a direction in which the bulged portion extends so as to flow the oil scraped up by the rotating member in the mission chamber to the outside of the engine case. ,
The flow channel is formed to have a circular cross section, the center of the flow channel is deviated from the center of the bulging portion, and a part of the contour line of the flow channel intersects the contour line of the bulging portion in a sectional view. An opening is formed in the bulging portion, and the flow passage and the transmission chamber are communicated with each other at the opening, and the opening is formed along the axial direction of the rotation center of the rotating member. Is located at the center or the upper part of the bulging portion.

(Function) A bulging portion that extends in a straight line having a substantially circular cross section is formed on a wall portion of the engine case facing the mission chamber, and the bulging portion is formed by a drill whose center line is deviated from the cross sectional center of the bulging portion. Since the flow path is formed by processing the portion in the extending direction, the flow path can be formed by one-time processing, and the processing can be simplified and the processing time can be shortened.

(Embodiment) A preferred embodiment of the present invention will be described below with reference to the accompanying drawings.

FIG. 1 is a side view of a motorcycle, FIG. 2 is a transverse sectional view of an engine, and FIG. 3 is a longitudinal sectional view.

In the drawing, (1) is a motorcycle, (3) is a front wheel, (5) is a rear wheel, (7)
Is the body frame, and the left and right front forks (11), (11)
A handle (15) for steering the front wheels (3) is provided on the top, and a rear fork (10) for suspending the rear wheels (5) is provided at the rear of the body frame (7).
Is swingable up and down.

The vehicle body frame (7) is composed of a main pipe (18) extending from the head tube (16) to the rear and composed of two upper and lower pipes, and left and right down tubes (20) depending from the main pipe (18).
And a down tube lower (21) that extends substantially horizontally rearward from the lower end of the down tube (20), and a down tube lower (21).
(21) A center tube (22) for connecting the rear end and the main pipe (18) and the like.

The engine (E) is mounted on the down tube lower (21).

The engine (E) is a V-type two-cylinder two-cycle engine in which the cylinder block is V-shaped in a side view, and the engine case (24) of the engine (E) is an upper case (25) and a lower case.
(26) consists of A crank chamber (30) and a mission chamber (31) are formed between the upper case (25) and the lower case (26) in a state where these (25) and (26) are joined, and the crank chamber (30) and the mission are formed. The chamber (31) is separated from the upper case (25) and partition walls (25a) and (26a) formed in the lower case (26).

The crankcase (30) of the engine case (24) has front wheels (3).
On the side, the mission chamber (31) is arranged substantially horizontally between the front and rear wheels (3), (5) such that the mission chamber (31) is on the rear wheel (5) side. ((L) in Fig. 2
Shows a line parallel to the road surface. Further, two cylinder blocks (33a) and (33b), which are V-shaped in side view, are vertically formed on the front side of the crankcase (30) of the engine case (24). , Pistons (35a), (35b) are slidably inserted into the cylinder blocks (33a), (33b), respectively, and the pistons (35a), (35b) and the cylinder blocks (33a), (33b) are )
Combustion chambers (36a), (36b) are formed between the cylinder heads (34a), (34b) fixed to the. Further, exhaust passages (37a) and (37b) and scavenging passages (38a) and (38b) are formed in the cylinder blocks (33a) and (33b), respectively. Cylinder block (33a), (33
Of the b), the cylinder block (33a) is formed on the lower case (26) side and the cylinder block (33b) is formed on the upper case (25) side, that is, the engine case (24) is formed on the upper case (2).
5) The split surface (P) that divides into the lower case (26) extends approximately parallel to the ground in the middle of the upper and lower cylinder blocks (33b) and (33a), and the engine case (24) is approximately at the center of the height. It will be divided into upper and lower cases.

On the other hand, a crankshaft (40) is provided in the crank chamber (30), and a gear transmission mechanism (41) is provided in the mission chamber (31). The crankshaft (40) has its journal part rotatably supported by a ball bearing (41), and the two crankpin parts are connected to the pistons (35a) and (35b) described above by connecting rods (45a) and (45b), respectively. Are connected via. Further, the speed change gear mechanism (41) is composed of a main shaft (50) and a counter shaft (51) which are supported substantially in parallel via ball bearings (48) and (49), and these shafts (50) and (51) The spline-connected gears (55) and (56) are meshed with each other to form a gear train corresponding to the shift speed. This gear shifting mechanism
As well known in (41), the gears (55), (56) slide on the shafts (50), (51) in the axial direction by the operation of a gear shift lever (not shown),
The gear train corresponding to the operation of the shift lever is established to shift the engine power.

In the upper case (25), as shown in detail in FIG. 4, two intake passages (58a), (58b) are formed substantially parallel to each cylinder, and the intake passages (58a), (58b) are formed. One end of the crank chamber
The opening is made in (30) and the other end is connected to the carburetor (62) through the intake pipes (60a), (60b).

(63a) and (63b) are reed valves provided in the intake passages (58a) and (58b), and (64a) and (64b) are stoppers thereof.

A breather chamber (65) is formed between the intake passages (58a) and (58b) of the upper case (25), and the chamber (65) is formed in the upper case (25) and the lower case (26). It communicates with the mission chamber (31) by 66), while it is open to the atmosphere by a drain pipe (67).

In this embodiment, as shown in FIG. 5, the upper case (25)
And the lower case (26) are fastened with bolts (70) and (71). Among them, the bolt (70) is the partition wall (26a) of the lower case (26).
Screwed into the bolt hole (26a1) formed in and the bolt hole (25a1) formed in the partition wall (25a) of the upper case (25), while the bolt (71) is the inner wall of the scavenging passageway (38a) of the lower case (26). From the upper case (25) to the bolt hole (26a2) formed in the upper case (25) and the bolt hole (25a2) formed in the upper case (25), and then the upper case (25) and the lower case (26) are fastened. To be done.

By the way, a flow path (75) is formed in a wall portion of the engine case (24) which faces the mission chamber (31). The flow path (75) is for rotating the gears (55) and (56) in the mission chamber (31) to rotate and scrape the oil to the outside of the engine case (24) (for example, the tip of the push rod of the clutch). The flow path is formed as follows.

First, as shown in FIG. 6, a bulge portion (80) is formed in advance on the wall portion (24a) of the engine case (24) which faces the mission chamber (31). The bulging portion (80) has a substantially circular cross section, and is linearly formed along the engine case (24) (in the direction perpendicular to the paper surface of FIG. 2).

Next, as shown in FIG. 7, use a drill (81) having a center line (81a) deviated from the center (80a) of the cross section of the bulge (80) to bulge the bulge.
(80) is processed in the extending direction. As a result, a flow path (75) having an opening (80b) on the mission chamber (31) side is formed as shown in FIGS. That is, the flow path (7
5) is formed in a circular cross section, and the center of this flow path (75) is offset from the center of the bulging part (80), and as shown in FIG. 7, the outline of the flow path (75) with a circular cross section. An opening portion (80b) is formed by intersecting a part of the with the outline of the bulging portion (80).
The flow path (75) and the mission chamber (31) communicate with each other through the opening (80b).

According to the present embodiment as described above, the bulging portion (80), a drill having a center line (81a) deviated from the cross-sectional center (80a) of the bulging portion (80)
By processing with (81), the flow path (75) can be formed by one-time processing, and the processing can be simplified and the processing time can be shortened.

(Effect of the Invention) As described above, according to the present invention, the flow path is formed in a circular cross section, and the center of the flow path is deviated from the center of the bulging portion to form a part of the outline of the flow path. Since the opening portion is formed in the bulging portion by intersecting the outline of the bulging portion in a cross-sectional view, there are a conventional processing for forming a flow path and a processing for forming the opening portion. The two processes are not required, and the openings can be formed at the same time when the flow path is processed, so that the process can be simplified and the process time can be shortened.

Further, since the oil is introduced into the flow channel through the opening formed in the bulging portion, the oil can be introduced into the flow channel without interposing a special member. Further, when oil is introduced into the flow path, it is scraped through the rotary member in the mission chamber, so an oil pump or the like is not required, and the number of parts can be reduced.

[Brief description of drawings]

Fig. 1 is a side view of a motorcycle, Fig. 2 is a transverse sectional view of an engine, Fig. 3 is a longitudinal sectional view of the same, Fig. 4 is a sectional view taken along line IV-IV of Fig. 2, and Fig. 5 is an upper case. FIG. 6 is an enlarged cross-sectional view of a main part showing a joining state between the lower case and the lower case, FIG.
FIG. 7 is a bulging portion showing a processed state, and FIGS. 8 to 11 are drawings showing a conventional flow path forming procedure. In the drawing, (24) is an engine case, (31) is a mission chamber, (75) is a flow path, (80) is a bulging portion, (81a) is a cross-sectional center of the bulging portion, (81) is a drill, (81a) is the center line of the drill.

Claims (1)

[Scope of utility model registration request] 1. A mission chamber is formed in an engine case, a thick bulging portion extending linearly is formed in a wall portion of the engine case facing the mission chamber, and the mission chamber is provided in the bulging portion. In an engine case in which a flow path for causing the oil scraped up by the rotating member to flow out of the engine case is formed in the extending direction of the bulging portion, the flow path is formed in a circular cross section and The center is offset from the center of the bulging portion, and a part of the outline of the flow path intersects the outline of the bulging portion in a cross-sectional view to form an opening portion in the bulging portion, A portion that communicates the flow path with the mission chamber, the opening is formed along the axial direction of the rotation center of the rotating member, and the opening is located in the center or upper part of the bulging portion. An engine case featuring.