JPH04287855A - Cooling device for internal combustion engine - Google Patents

Abstract

PURPOSE:To prevent the clogging of upper side groove-like refrigerant passages requiring refrigerant performance so as to prevent the increase of unnecessary pressure loss by supplying refrigerant to the groove like refrigerant passages on the upper side of a cylinder liner from a pump through a filter, and supplying refrigerant to groove like refrigerant passages on the lower side directly from the pump. CONSTITUTION:A refrigerant force-feed pump 30 delivers refrigerant in the state of being branched into two. One refrigerant is provided with large refrigerant pressure and supplied to an inflow port 28a through a filter 31, and the other refrigerant is provided with small refrigerant pressure and supplied directly to an inflow port 28b. The refrigerant at the inflow port 28a is distributed into cylinder upper part annular cooling grooves 211-213 through a communicating groove 24a and flows out of an outflow port 29a through a communicating groove 25a. The refrigerant at the inflow port 28b is distributed into cylinder lower part annular cooling grooves 214-216 through a communicating groove 24b and flows out of an outflow port 29b through a communicating groove 25b. The refrigerant from the outflow port 29a and that from the outflow port 29b are united and circulated to the pump 30 through a radiator.

Description

[Detailed description of the invention]

0001

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to an internal combustion engine cooling system for cooling cylinders of an internal combustion engine.

0002

2. Description of the Related Art Conventionally, as described in Japanese Utility Model Application Laid-Open No. 63-168242, there has been a cooling system that cools an internal combustion engine by providing a spiral or annular cooling groove on the outer periphery of a cylinder liner to allow a refrigerant to flow therethrough.

FIGS. 2A, 2B, and 2C show a plan view, a front view, and a side view of an example of a conventional cylinder liner, respectively. In the figure, annular cooling grooves 11 are formed at equal intervals on the outer periphery of a thin linear liner 10. Further, all the annular cooling grooves 11 are communicated with each other through communicating passages 12 and 13 formed in the axial direction. The refrigerant flowing in from the inlet 14 flows through the communication path 12
It is distributed to each annular cooling groove 11 through the communication passage 13 and flows out from the outlet 15.

0004

[Problem to be Solved by the Invention] In the above-mentioned cooling device, dirt or water scale in the refrigerant is removed from the annular cooling groove 11 or the communication path 1.
In order to prevent the refrigerant from clogging the refrigerant 2, it is conceivable to supply the refrigerant to the inlet 14 through a filter.

However, when all of the refrigerant passes through a filter, the pressure loss of the refrigerant becomes large, and the drive loss of the pump also increases.
There was a problem in that the refrigerant flow rate of the cooling device decreased, resulting in a decrease in cooling capacity.

[0006] The present invention has been made in view of the above points.
By supplying refrigerant through a filter only to the groove-shaped refrigerant passage on the upper side of the cylinder liner, the groove-shaped refrigerant passage on the upper side where cooling performance is required is prevented from clogging, and unnecessary pressure loss of the refrigerant is increased. An object of the present invention is to provide a cooling device for an internal combustion engine that prevents the above.

[0007]

[Means for Solving the Problems] In order to solve the above problems, the present invention provides a cooling system for an internal combustion engine that cools a cylinder liner by forming a plurality of groove-shaped refrigerant passages on the outer periphery of a cylinder liner. The groove-shaped refrigerant passages are made independent on the upper side and lower side near the combustion chamber in the axial direction of the cylinder liner, and refrigerant is supplied from the pump through a filter to the upper groove-shaped refrigerant passage, and the groove-shaped passages on the lower side are separated. Refrigerant is supplied directly to the refrigerant passage from a pump.

[0008]

[Function] In the present invention, by supplying refrigerant to the upper groove-shaped refrigerant passage through a filter, it is possible to prevent the upper groove-shaped refrigerant passage, which requires cooling performance, from clogging, and also to prevent the upper groove-shaped refrigerant passage, which requires cooling performance, from clogging. By supplying the refrigerant directly to the shaped refrigerant passage without passing it through a filter, the pressure loss of the refrigerant is prevented from increasing.

[0009]

DESCRIPTION OF THE PREFERRED EMBODIMENTS FIG. 1 shows a sectional view of an embodiment of a cooling system for an internal combustion engine according to the present invention.

In the figure, 20 is a cylinder liner, and annular cooling grooves 211 to 216 are formed on the outer periphery of the cylinder liner 20 at approximately equal intervals in the axial direction.

[0011] This cylinder liner 20 is inserted into a bore formed in a cylinder block 22. Bore inner circumferential surface 2
3, communication grooves 24a, 24b and 25a, 25b extending in the axial direction are provided at positions at a rotation angle of 180 degrees. They are separated by walls 26 and 27, respectively. Further, the cylinder block 22 has communication grooves 24a, 2
Inflow ports 28a, 28b and communication groove 25 that communicate with each other
Outlets 29a and 29b are formed which communicate with a and 25b, respectively. When the cylinder liner 20 is inserted into the bore, the outer peripheral surface 20a of the cylinder liner 20 is the inner peripheral surface 2 of the bore.
It abuts substantially the entire surface except for the communication grooves 24a, 24b, 25a, and 25b of No. 3. Furthermore, a separation wall 26,
27 come into contact with each other.

The refrigerant pump 30 divides the refrigerant into two parts and sends the refrigerant into two branches, one of which is supplied to the inlet 28a through the filter 31 with a high refrigerant pressure, and the other is supplied directly to the inlet 28b with a low refrigerant pressure. Supplied. Inflow port 28a
The refrigerant is distributed to the cylinder upper annular cooling grooves 211 to 213 through the communication groove 24a, and is distributed to the cylinder upper annular cooling grooves 211 to 213 through the communication groove 25a.
It passes through and flows out from the outlet 29a. The refrigerant supplied to the inlet 28b passes through the communication groove 24b and is distributed to the annular cooling grooves 214 to 216 at the bottom of the cylinder.
It flows out through the outlet 29b. Outlet 29a, 2
The refrigerant flowing out from 9b is combined and circulated to pump 30 through a radiator (not shown).

In this way, the refrigerant is supplied through the filter 31 to the annular cooling grooves 211 to 213 in the upper part of the cylinder, which are close to the combustion chamber and require good cooling performance. It can prevent clogging, and the refrigerant pressure is said to be high, so
Considering the lubrication of the inner circumferential surface of the cylinder liner 20 and the sliding parts of the piston (not shown), boundary lubrication with a low lubricating oil temperature and a thick film can be performed. In addition, since the refrigerant is supplied to the annular cooling grooves 214 to 216 at the bottom of the cylinder without passing through a filter, the pressure loss of the refrigerant is not increased unnecessarily, and the refrigerant pressure is small, so that the piston Regarding the lubrication of the sliding parts, fluid lubrication with a high lubricating oil temperature and a thin film thickness can be performed.

[0014]

As described above, according to the cooling system for an internal combustion engine of the present invention, by supplying refrigerant through the filter only to the groove-shaped refrigerant passages on the upper side of the cylinder liner, the refrigerant can be cooled in the upper part where refrigerant performance is required. This is extremely useful in practice since it is possible to prevent the groove-shaped refrigerant passages from clogging and also to prevent an unnecessary increase in pressure loss of the refrigerant.

[Brief explanation of the drawing]

FIG. 1 is a cross-sectional structural diagram of an embodiment of the device of the present invention.

FIG. 2 is a plan view, a front view, and a side view of an example of a conventional device.

[Explanation of symbols]

20 Cylinder liners 211 to 216 Annular cooling groove 22 Cylinder blocks 24a, 24b, 25a, 25b Communication grooves 28a, 2
8b Inlet 29a, 29b Outlet 30 Pump 31 Filter

Claims (1)

[Claims] 1. A cooling device for an internal combustion engine that cools the cylinder liner by forming a plurality of groove-shaped coolant passages on the outer periphery of the cylinder liner, wherein the plurality of groove-shaped coolant passages are used for combustion in the axial direction of the cylinder liner. The upper side and lower side near the room are separated, and the refrigerant is supplied from a pump through a filter to the groove-shaped refrigerant passage on the upper side, and the refrigerant is directly supplied from the pump to the groove-shaped refrigerant passage on the lower side. A cooling device for an internal combustion engine characterized by: