JPS6015961Y2 - 2-axis balancer engine - Google Patents

Description

[Detailed Description of the Invention] The present invention relates to a two-shaft balancer engine that has a crankcase with high strength, is compact, and is inexpensive.

Conventionally, in a two-shaft balancer engine, oil leakage was prevented in the camshaft pivot hole that pivots one end of the camshaft and each balancer shaft pivot hole that pivots one end of each of the 11th and 2nd balancer shafts. It is designed to be covered with an oil-tight lid.

The oil-tight lid is prevented from being removed by a structure in which a mounting bolt that is inserted through the mounting flange of each lid is screwed into one side wall of the crankcase.

However, with this conventional structure, it is relatively difficult to form a host part into which the mounting bolt is screwed using aluminum alloy die-casting, and the screw hole formed in this boss part penetrates into the crank chamber. There is a risk of oil leaking from the hole, the strength of the crankcase will be reduced by drilling the screw hole, and the spacing between each bolt and each pivot hole should be relatively large in order to work on the lines of each mounting bolt. There are problems such as the need to take

In order to solve the above problem, the present invention supports each oiltight cover in a way that prevents it from being removed by the mounting flange of the main bearing case that fits inside the crankcase pivot hole that pivots one end of the crankshaft. It is characterized by having

Hereinafter, embodiments of the present invention will be described based on the drawings.

Figure 1 is a front view of the horizontal water-cooled two-shaft balancer engine, Figure 2
The figure is a cross-sectional view taken along the line A--A, and the crankcase 2 of the engine 1 is integrally formed with a cylinder valve chuck 3 by die-casting from an aluminum alloy.

Reference numeral 4 is a head block, and 5 is a rocker arm cover.

The front wall 6 of the crankcase 2 includes a crankshaft pivot hole 8 for pivotally supporting the crankshaft 7, and both first and second balancer shafts 9.
, 10, each balancer shaft pivot hole 11,
A camshaft pivot hole 13 for pivotally supporting the camshaft 12 is provided transparently.

The oil-tight lid 14 covering each of the balancer shaft pivot holes 11 is constructed by interposing an O-ring 16 between the outer race of the Haranza shaft hair ring 15 fitted in the pivot hole 11. It is fitted in a sealed manner.

An oil-tight lid 14 is similarly fitted into the camshaft pivot hole 13 in a sealing manner.

Reference numeral 17 denotes a main bearing case, which is fitted into the crankshaft pivot hole 8 and into which the main bearing 18 fitted onto the crankshaft 7 is fitted in a positioning manner.

This main bearing case 17 is fixed to the front side of the crankcase 2 with bolts 20.

Some of these bolts 20 are attached to the bearing case 17.
This bolt also serves as a bolt for fixing the bearing cover 21' to the front side of the bearing cover 21'.

The mounting flange portion 21 of the bearing case 17 covers part of the outer end surfaces of the balancer shaft pivot hole 11 and the cam shaft pivot hole 13.

Each oiltight M14 cannot be pulled out to the front side of the crankcase 2 by being stopped by the mounting flange 21 of the main bearing case 17 fixed to the crankcase 2 on its front end surface.

As explained above, in the present invention, each oil-tight cover 14 that seals the cam shaft pivot hole 13 and both balancer shaft pivot holes 11 in an oil-tight manner is attached to the mounting flange portion of the main bearing case 17.
1, the removal is in the form of a stop, and the receiving part is in the form of a stop, so compared to the conventional type in which each oiltight cover 14 is fixed to the crankcase 2 with a mounting bolt, the mounting bolt can be omitted, and it is an inexpensive product with fewer parts. Can be done.

Moreover, there is no need for the effort of tightening and operating the mounting bolts, and the cost of assembling each oiltight lid 14 can be reduced.

In addition, the screw holes for screwing the mounting bolts can be omitted, so there is no need to reduce the strength of the crankcase 2. Those axes because there is no need to set intervals for group work? , 9, 10, and 12, the crankcase 2 can be made smaller.

Furthermore, since there is no need to provide the crankcase with a boss portion for recessing the screw hole, the crankcase 2 can be formed easily and at low cost.

[Brief explanation of the drawing]

The drawings show an embodiment of the present invention, and FIG. 1 is a front view of a horizontal water-cooled two-shaft balancer engine, and FIG. 2 is a cross-sectional view taken along line A--A. 2...Crank case, 6...-side wall, 7...Crankshaft, 8...Crankshaft pivot hole, 9... 1st balancer axis, 10...
...Second balancer shaft, 11...Balancer shaft pivot hole, 12...Cam shaft, 13...Cam shaft pivot hole, 14...・Oiltight lid, 17...
Main bearing case, 21... Mounting flange part.

Claims (1)

[Scope of utility model registration request] A crankshaft pivot hole 8 for pivotally supporting the crankshaft 7, a camshaft pivot hole 13 for pivotally supporting the camshaft 12, and first and second balancer shafts 9 and 10 are provided in the side wall 6 of the crankcase 2. Each of the balancer shaft pivot holes 11 to be pivoted is transparently provided, and these pivot holes 11 and 13 are oil-tightly sealed in the cam shaft pivot hole 13 and both balancer shaft pivot holes 11, respectively. The mounting flange portion 21 of the main bearing case 17, which is fitted inside the crankshaft pivot hole 8, is fitted with an oil-tight lid 14 that fits inside the crankshaft pivot hole 8. A two-shaft balancer engine characterized in that the mounting flange portion 21 is fixed to the oil-tight i14 in a manner to prevent removal.