JPH0441219Y2 - - Google Patents

Description

[Detailed Description of the Invention] [Technical Field of the Invention] This invention relates to a multi-cylinder water-cooled engine in which the cooling water outlet passages led out from the water jackets of two cylinder heads are controlled by one thermo valve.

[Technical background of the invention and its problems]

V-type, square 4 mounted on motorcycles, etc.
In a multi-cylinder water-cooled engine such as a type, each cylinder cannot be configured by an integrated cylinder head, so it is separated into several parts. In this case, the cooling water outlet passages led out from the water jackets of the two cylinder heads and connected to the radiator are merged, and the amount of cooling water flowing out of both cylinder heads is controlled by a thermo valve placed on the downstream side of the merging part. Often controlled at the same time.

For example, as shown in Fig. 4, in an engine in which a cylinder block a and a cylinder block B are arranged in parallel one behind the other, and cylinder heads c and d are connected to each other, cooling water outlets are connected to water jackets e and f of both cylinders c and d. A thermovalve j is attached to a cooling water outlet h on the rear side using a thermovalve cover k, and is connected to a radiator via a conduit l. The front cooling water outlet g is connected to the cooling water outlet h upstream of the thermovalve j via the connecting pipe i.

With the above structure, the cooling water in both cylinder heads c and d join together and flow out to the radiator while the flow rate is controlled by the thermovalve j. However, since the confluence part is located at the cooling water outlet h of the rear cylinder head d, the cooling water flow rate of the rear cylinder head d is equal to the cooling water flow rate of the front cylinder head c due to the difference in distance from the water jackets e and f. become more,
There is a difference in cooling performance. This causes a problem in that the outputs of each cylinder become unbalanced, making the multi-cylinder engine rotate unsmoothly and reducing output performance.

[Purpose of invention]

The purpose of this invention is to solve the above problems and
The objective is to obtain a multi-cylinder water-cooled engine in which the amounts of cooling water that merge from two cylinder heads and are sent to a radiator are balanced so as not to affect output performance.

[Summary of the idea]

In order to achieve the above object, this invention has the following features. That is, the cooling water led out from the water jackets of the two cylinder heads is combined and connected to the radiator via a thermo valve installed immediately downstream, and the combined part is connected to the water jackets of the two cylinder heads. A first water jacket of the cylinder head is formed on one side of the cylinder head, and an adjustment plate is installed at the merging portion. The second water jacket of the other cylinder head has a second opening in a side wall surface of the merging portion and communicates with the merging portion, and the adjusting plate
The cross-sectional area of the merging portion near the first opening is reduced at a position downstream of the first opening and facing the second opening, and the cross-sectional area of the merging portion in the second water jacket is reduced. It is arranged parallel to the axis near the second opening and controlled so that the amount of cooling water flowing out from both cylinder heads is equal.

[Example of idea]

Hereinafter, explanation will be made with reference to figures showing embodiments of this invention.

In FIG. 1, reference numeral 1 designates a cylinder head connected to one independent cylinder block of a multi-cylinder engine, and a cooling water outlet 3 led out from a water jacket 2 thereof opens upward. The cooling water outlet 3 functions as a confluence section as will be described later, and the water jacket 2 functions as a first water jacket. This water jacket 2 is attached to the upstream wall surface 3a of the cooling water outlet 3.
It has a first opening 2a nearby and communicates with the cooling water outlet 3. Further, 4 indicates a combustion chamber.

A thermovalve 6 is attached to the upper end of the cooling water outlet 3 with a thermovalve cover 5. A conduit 7 is connected to the thermovalve cover 5 to guide cooling water to the radiator. Also, the side wall surface 3b of the cooling water outlet 3
In this case, there is a union 8 immediately upstream of the thermovalve 6.
opens. A hose 9 connected to the cooling water outlet of another cylinder head water jacket is connected to this union 8, and the cooling water from that cylinder head joins the cooling water of the cylinder head 1 here, and the thermo valve 6 is connected to the hose 9. While being controlled,
As mentioned above, it is guided to the radiator. The above-mentioned other cylinder head water jacket, hose 9 and union 8 function as a second water jacket, and the opening 8b of the union 8 is formed in the side wall surface 3b as the second opening.

As shown in FIGS. 2 and 3, the thermovalve 6 is attached to the valve body 1 so as to block the cooling water outlet 3.
0 with a seal ring 11, and its valve port 10a
The valve plate 12 is brought into elastic contact with a spring 13. The tail end of the spring 13 is the valve body 10
Bottom part 14a of U-shaped stay 14 extending from
Locks on the top surface. A thermocylinder 15 is fixed to the valve plate 12 and is supported on the stay bottom 14a so as to be slidable in the axial direction. Thermo cylinder 1
A thermowax is sealed in the valve body 5, and a Lumo piston 16 is inserted through the valve body 5, the tip of which is in contact with the inner surface of the cap portion 17 of the valve body 10. When the temperature of the cooling water rises, the thermowax inside the thermocylinder 15 expands and pushes out the thermopiston 16, and the tip of the thermopiston 16 touches the cap part 1.
7, the thermo cylinder 15 descends, the valve plate 12 opens, and the cooling water flows out through the valve port 10a and into the radiator.

Next, an adjustment plate 18 is placed on the upper surface of the stay bottom 14a.
is placed. The adjustment plate 18 is placed in a shape that reduces the lower cross-sectional area near the first opening 2a of the cooling water outlet 3, and is set parallel to the axis near the opening 8b of the union 8.

By placing the adjustment plate 18 in this way, the cooling water outlet 3 can be adjusted from the water jacket 2 of the cylinder 1.
The amount of cooling water flowing from the other cylinder head through the union 8 to the cooling water outlet 3 is not restricted. Therefore, the amount of cooling water in cylinder head 1, which is originally short-circuited to cooling water outlet 3 and has a large flow rate, is reduced and becomes equal to the flow rate from other cylinder heads, equalizing the cooling performance in both cylinder heads and improving engine performance. Make it stable.

The shape and area of the adjusting plate 18 are set to be optimal for equalizing the flow rate. In addition, the stay bottom portion 14a
may be formed as an adjusting plate. Thermo valve 6
If it is necessary to place the adjustment plate in a position where it is not available, install it by separate means.

[Effect of idea]

As mentioned above, the multi-cylinder water-cooled engine according to this invention merges the cooling water drawn out from the water jackets of the two cylinder heads, and this junction is formed in one of the two cylinder heads. The first water jacket of the cylinder head, on which the adjusting plate is installed and the merging portion is formed, has a first opening near the upstream wall surface of the merging portion, and communicates with the merging portion. The second water jacket of the cylinder head has a second opening on a side wall surface of the junction and communicates with the junction; The cross-sectional area of the merging portion near the first opening is reduced at a position facing the second opening, and the second water jacket is placed in a state parallel to the axis near the second opening. This system equalizes the amount of water coming from both cylinder heads and directs it to the thermo valve, allowing the cooling performance of both cylinders to be equalized and controlled by a single thermo valve. . The adjustment plate can be easily installed using an existing thermo-valve, and the flow rate can be restricted in a wide range by simply changing the shape and area, making it easy to adjust and achieving great effects at low cost. can.

[Brief explanation of drawings]

FIG. 1 is a longitudinal sectional side view of one cylinder head of a multi-cylinder engine showing an embodiment of this invention; FIG. 2 is a longitudinal sectional front view of the cooling water outlet taken along arrow A-A in FIG. 1;
3 is a bottom view as viewed from arrow B in FIG. 1, and FIG. 4 is a longitudinal sectional side view illustrating a conventional multi-cylinder water-cooled engine cylinder head. 1... Cylinder head, 2... Water jacket, 3... Cooling water outlet, 6... Thermo valve,
8... Union, 14... Stay, 15... Thermo cylinder, 16... Thermo piston, 18...
Adjustment board.

Claims (1)

[Scope of utility model registration request] The cooling water led out from the water jackets of the two cylinder heads is combined and connected to the radiator via a thermo valve installed immediately downstream, and the merging section is connected to the water jacket of the two cylinder heads. A first water jacket of the cylinder head is formed on one side, and an adjusting plate is installed at the merging portion, and the first water jacket of the cylinder head in which the merging portion is formed has a first opening in the vicinity of the upstream wall surface of the merging portion. The second water jacket of the other cylinder head is in communication with the merging portion, and has a second opening in a side wall surface of the merging portion, and is communicated with the merging portion.
The adjusting plate is arranged at a position downstream of the first opening and facing the second opening to reduce the cross-sectional area of the merging portion near the first opening and to reduce the cross-sectional area of the merging portion near the first opening and to A multi-cylinder coolant engine, characterized in that the multi-cylinder coolant engine is arranged parallel to the axis near the second opening in the water jacket, and is controlled so that the amount of coolant flowing out from both the cylinder heads is equal.