JPH0614029Y2 - Engine cylinder liner cooling structure - Google Patents

Description

DETAILED DESCRIPTION OF THE INVENTION (Industrial field of application) The present invention relates to a cooling structure for a cylinder liner that is press-fitted into a cylinder of an engine.

(Prior Art) In some engines, a cylinder liner is press-fitted into the inner peripheral surface of the cylinder body (for example, Japanese Patent Publication No. 49-437).
(See FIG. 7 of Japanese Patent Publication No. 38). A cylinder liner of this type is shown in FIG.

In FIG. 4, reference numeral 1 denotes a cylinder liner, which has a flange portion 1a on the combustion chamber 2 side of the engine and is press-fitted into the inner peripheral surface 10a of the cylinder body 10 from the combustion chamber 2 side. On the inner peripheral surface 10a of the cylinder body 10, as shown in FIG.
A chamfered portion 11 for press-fitting the cylinder liner is provided on the upper end 10b.
On the other hand, the outer peripheral surface 1 of the cylinder liner 1 is formed.
b is polished. Reference numeral 3 is a relief recess for polishing, which is formed in the outer peripheral surface 1b of the cylinder liner 1 in the vicinity of the flange portion 1a. A water jacket 12 is formed in the cylinder body 10, and the cylinder liner 1 is cooled by the cooling water in the water jacket 12. In addition,
5 is a seal ring.

(Problems to be Solved by the Invention) In the above-mentioned conventional example, a small space 6 exists between the chamfered portion 11 for press-fitting the cylinder liner and the relief recess 3 for polishing. Since 6 is located between the water jacket 12 near the upper end 1c on the combustion chamber 2 side of the cylinder liner 1 and is a kind of heat insulating space, heat from the vicinity 1c near the upper end to the water jacket 12 is thereby provided. Is difficult to reach. Moreover, since the vicinity 1c of the upper end of the cylinder liner 1 is arranged at a position close to the combustion chamber 2 of the engine, the temperature 1c (the end portion on the combustion chamber side) of the upper end of the cylinder liner 1 is likely to become high in temperature. Therefore, the formation of the space 6 between the upper end vicinity 1c and the water jacket 12 is not preferable for sufficiently cooling the upper end vicinity 1c of the cylinder liner 1 on the combustion chamber 2 side.

Further, as shown in FIG. 4, when two cylinders 7A and 7B are provided, the cylinders 7A and 7B are arranged close to each other, so that the cylinder main body 10 between the adjacent cylinder liners 1 and 1 has no water. It is not possible to provide a jacket. Therefore, the upper end vicinity 1c of the cylinder liner 1 between the cylinders 7A and 7B cannot be sufficiently cooled.

This invention was made in view of the above conventional inconveniences,
An object of the present invention is to provide a cooling structure for an engine cylinder liner capable of sufficiently cooling the combustion chamber side end of the cylinder liner having a collar portion.

(Means for Solving the Problems) In order to achieve the above object, the present invention provides a chamfered portion for press-fitting a cylinder liner by forming a plurality of grooves on an end surface of the cylinder body that abuts on a flange portion of the cylinder liner. The space formed between the relief recess for polishing and the water recess in the cylinder body is communicated with the space.

Further, in an engine in which a plurality of cylinders are arranged in parallel and close to each other, a groove is formed on the upper surface of the cylinder body between adjacent cylinder liners, and both ends of this groove are communicated with the water jacket of the cylinder body. Is preferred.

(Operation) According to the inventions of the claims of this application, a plurality of grooves are formed in the end surface of the cylinder body, and the grooves are formed between the chamfered portion for press-fitting the cylinder liner and the relief recess for polishing. Since the space is communicated with the water jacket, the cooling water in the water jacket flows through the groove through the groove, and the end of the cylinder liner on the combustion chamber side is sufficiently cooled by the cooling water.

Particularly, according to the invention of claim (2), the groove is formed on the upper surface of the cylinder body between the adjacent cylinder liners, and both ends of the groove are communicated with the water jacket, so that the cooling water in the water jacket is Flow through the groove, and the cooling water sufficiently cools the ends of the cylinder liner on the combustion chamber side between the cylinders.

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

1 is a sectional view taken along the line I-I of FIG. 2, and in FIG. 1, reference numeral 30 is an engine having two cylinders 7A and 7B,
It is mounted on a vehicle body of a motorcycle (not shown) in a forward leaning posture. That is, the front portion 1 of the cylinder body 10 shown in FIG.
The rear part 10f is inclined so as to be higher than 0e. The cylinders 7A and 7B are arranged in parallel with each other in the left-right direction A of the vehicle body. The cylinder body 10
Is integrally formed by casting such as aluminum die cast.

In the cylinder body 10 shown in FIG. 1, a plurality of grooves 21A and 21B are formed on the end surface 10c which is in contact with the collar portion 1a of each cylinder liner 1 at a position separated by 180 degrees as shown in FIG. It is molded. These grooves 21
As shown in FIG. 3, A and 21B have a space 6 formed between the chamfered portion 11 for press-fitting the cylinder liner and the relief recess 3 for polishing, and the water jacket 12 in the cylinder body 10. It is intended for communication.

On the other hand, one groove 22 is formed by casting in the upper surface 10d of the cylinder body 10 between the adjacent cylinder liners 1 and 1 in FIG. As shown in FIG. 2, both ends 22a and 22b of the groove 22 communicate with the water jacket 12 of the cylinder body 10, respectively.

In addition, 23 is a pin contact part, and the cylinder main body 10 after casting
This is a portion with which a push-out pin (not shown) for die cutting contacts when die is die-cut from the die. Other configurations are the same as those in FIG. 4, and the same portions are denoted by the same reference numerals and detailed description thereof will be omitted.

In the above structure, the end surface 10 of the cylinder body 1 of FIG.
Since a plurality of grooves 21A and 21B for communicating the space 6 and the water jacket 12 are formed in c as shown in FIG. 2, the cooling water in the water jacket 12 is, as shown by an arrow A1,
Pass through the space 6 from the groove 21A on the front portion 10e side to the rear portion 10f.
Flows to the side groove 21B. Therefore, the space 6 which is a conventional heat insulating space sufficiently cools the vicinity 1c of the upper end of the cylinder liner 1 on the combustion chamber 2 side of FIG.

Further, in the case where the groove 22 communicating with the water jacket 12 is formed on the upper surface 10d of the cylinder body 10 between the cylinders 7A and 7B in FIG. 1, when the groove 22 communicating with the water jacket 12 is formed, as shown by an arrow A2 in FIG. Water jacket 1 on part 10e
The cooling water in 2 flows through the groove 22 to the water jacket 12 on the rear portion 10f side. Therefore, the cooling water sufficiently cools the vicinity 1c of the upper end of the cylinder liner 1 between the cylinders 7 in FIG.

By the way, it is possible that the diameter of the space 6 in FIG. 2 is small and cooling water does not easily flow into the space 6. However, the cooling water in the space 6 is boiled and vaporized if it stays, thereby partially increasing the pressure in the space 6, and this pressure causes a part of the cooling water to be extruded. Is obtained. Further, the vicinity 1c of the upper end of the cylinder liner 1 is likely to reach an extremely high temperature. Therefore, even if the temperature (water temperature) in the space 6 reaches the boiling point of 120 to 130 degrees, the vicinity 1c of the high temperature should be cooled. You can

Further, in the engine mounted on the vehicle body of the motorcycle, the cylinder main body 10 may have a rear portion 1 rather than a front portion 10e.
Since 0f is inclined so as to be higher, when the cooling water boils in the space 6 and the groove 22, as shown by arrows A1 and A2, respectively, from the lower front portion 10e side to the higher rear portion 10e. Steam easily flows toward the 10f side.
Therefore, there is no risk of steam or air being trapped.

Further, in this embodiment, since the grooves 21A, 21B, 22 are formed by casting, there is no need to separately perform groove processing, and there is an advantage that the production process can be simplified.

Needless to say, the grooves 21A, 21B, 22 may be formed by using a tool such as a drill instead of forming by casting.

(Effects of the Invention) As described above, according to the invention of each claim, since the cooling water is introduced into the space between the chamfered portion and the escape recess, the above-mentioned space, which is a conventional heat insulating space, is used. The end of the cylinder liner having the flange portion on the combustion chamber side can be sufficiently cooled.

In particular, according to the invention of claim (2), the groove is formed on the upper surface of the cylinder body between the adjacent cylinder liners, and the cooling water is introduced into this groove, so that the combustion chamber side of the cylinder liner between the cylinders is provided. The edges can also be cooled sufficiently.

[Brief description of drawings]

1 is a sectional view showing a cooling structure of an engine cylinder liner according to the present invention, FIG. 2 is a sectional view taken along the line II-II in FIG. 1, and FIG. 3 is an enlarged sectional view in the vicinity of the collar portion in FIG. FIG. 4 is a cross-sectional view showing a conventional cooling structure for a cylinder liner of an engine, and FIG. 5 is an enlarged cross-sectional view in the vicinity of the collar portion of FIG. 1 ... Cylinder liner, 1a ... Collar part, 1b ... Outer peripheral surface, 2 ... Combustion chamber, 3 ... Escape recess, 6 ... Space, 7
A, 7B ... cylinder, 10 ... cylinder body, 10a ...
Inner peripheral surface, 10b ... upper end, 10c ... end surface, 10d ...
Top, 11 ... Chamfer, 12 ... Water jacket, 21
A, 21B, 22 ... Grooves, 22a, 22b ... Both ends.

Claims (2)

[Scope of utility model registration request] 1. A cylinder liner having a flange on the combustion chamber side of the engine is press-fitted into the cylinder body of the engine from the combustion chamber side, and a chamfered portion for press-fitting the cylinder liner is formed at the upper end of the inner peripheral surface of the cylinder body. A cooling structure for an engine cylinder liner, wherein an outer peripheral surface of the cylinder liner is ground, and a clearance recess for polishing is formed in the outer peripheral surface of the cylinder liner in the vicinity of the collar portion. A cylinder liner for an engine in which a plurality of grooves are formed on an end surface that abuts on the flange portion, and a space formed between the chamfered portion and the escape recess for polishing communicates with a water jacket in the cylinder body. Cooling structure. 2. The engine according to claim 1, wherein a plurality of cylinders are arranged in parallel and close to each other, and a groove is formed on an upper surface of a cylinder body between adjacent cylinder liners.
Cooling structure for engine cylinder liner with both ends of this groove communicating with the water jacket of the cylinder body.