JPS5949403B2 - engine cooling system - Google Patents

Description

DETAILED DESCRIPTION OF THE INVENTION The present invention relates to an engine cooling system, and in particular to a cooling system in which a water-cooled lubricant cooler and a heater are installed in the cooling channel system of a water-cooled engine. This is designed to maintain the heater properly and improve the effectiveness of the heater.

Conventionally, when a lubricating oil cooler and a heater are installed in the cooling channel system of a water-cooled engine, cooling water flows between the engine 1, water pump 2, and radiator 3 in the direction of the arrow, as shown in FIG. Branch channels 5 and 6 are provided independently in the main cooling channel 4 that is forced to circulate, and the upstream end of the branch channel 5 is located inside the engine 1 so that the cooling water flows into the branch channel 5. It branches from a high water pressure part of the main cooling water channel 4, passes through a lubricating oil cooler 7, and reaches a low water pressure part of the main cooling water channel 4, that is, downstream of the branching part between the main cooling water channel 4 and the branch water channel 5, and the water The branch waterway 6 is provided so as to rejoin the main cooling waterway 4 upstream of the pump 2.
is a manually operated flow control system whose upstream end is branched from a high-pressure part of the main cooling water channel 4 in the engine 1 so that a sufficient amount of cooling water flows into the branch waterway 6 in order to improve heating performance. After passing through the valve 8, the main cooling water channel 4 passes through the heater 9.
In particular, it is provided so as to rejoin the main cooling water channel 4 in a part where the water pressure is low, that is, downstream of the radiator 3 outlet and upstream of the water pump 2.

In addition, 10 in the figure is an intermediate between the radiator 3 of the main cooling channel 4 and the engine 1 outlet, which switches the cooling water that cooled the engine 1 to the water pump 2 through the radiator 3 or the bypass passage 4 depending on the water temperature. This is a thermo valve installed.

By the way, the relationship between the water temperature and oil temperature with respect to the outside temperature during engine operation is shown in Figure 2. When the outside temperature is low, the water temperature tends to be lower than the oil temperature, and when the outside temperature is high, the water temperature tends to be lower than the oil temperature. There is.

Here, the water temperature is the temperature of the cooling water in the branch waterway 5 immediately upstream of the lubricating oil cooler 7 or the main cooling waterway 4, and the oil temperature is the temperature of the lubricating oil in the oil pan (not shown) of the engine 1. Both of them indicate the temperature immediately before passing through the lubricating oil cooler 7, that is, immediately before the lubricating oil cooler 7 exchanges heat between the water temperature and the oil temperature.

That is, the tendency shown in FIG. 2 above is that the circulation of cooling water to the radiator 3 is controlled by the thermovalve 10 installed in the main cooling water channel 4, and the water temperature is almost the same as that of the thermovalve 10 regardless of changes in the outside temperature. While the temperature is maintained near the set temperature, the lubricating oil stored in the oil pan 5 is affected by the outside temperature through the oil pan, which has a relatively large surface area, and the lower the outside temperature is, the cooler the lubricating oil is and the lower the oil temperature. This is thought to be caused by the

Therefore, in the prior art described above, the flow rate of cooling water supplied to the lubricating oil cooler 7 is always the same.

Even when the control valve 8 is opened when the outside temperature is low and the cooling water flows to the heater 9 side, the flow rate of the cooling water flowing to the lubricating oil cooler 7 side does not decrease slightly, but remains almost unchanged.

Therefore, as shown in the graph in Figure 2, when the outside air temperature is lower than the oil temperature and water temperature, that is, when the heater 9 is used, a large amount of cooling water flows into the lubricating oil cooler 7, causing the water temperature to drop. This caused a problem in that the effectiveness of the heater 9 deteriorated.

On the other hand, in order to prevent the water temperature from decreasing due to the lubricating oil cooler 7, if the flow rate of cooling water flowing to the lubricating oil cooler 7 side is reduced, the heater 9 can be turned off when the outside temperature is high, that is, when the oil temperature is higher than the water temperature. Since the flow rate hardly changes even when not in use, there is a drawback that the flow rate necessary to cool the lubricating oil is not secured, leading to an excessive rise in oil temperature.

This invention aims to eliminate the above-mentioned drawbacks.

A main cooling channel through which cooling water circulates between the engine and the radiator, a water pump interposed between the radiator outlet of the main cooling channel and the engine inlet, and a water pump interposed between the radiator inlet and the engine outlet of the main cooling channel. A thermo-valve interposed in between, and a water heater waterway that branches from the main cooling waterway inside the engine downstream of the water pump and upstream of the thermovalve, passes through the heater, and joins the main cooling waterway downstream of the radiator outlet and upstream of the water pump. At the same time, a lubricating oil cooler is provided by branching from the heater waterway upstream of the flow control valve provided upstream of the heater in the heater waterway and downstream of the branching point between the main cooling waterway and the heater waterway. By providing a lubricating oil cooler waterway downstream of the branch between the main cooling waterway and the heater waterway and merging with the main cooling waterway upstream of the water pump, the amount of water flowing into the lubricant cooler waterway can be adjusted to reduce the amount of water used by the heater. , to be affected by non-use, when the outside temperature is low, i.e. lower than the oil temperature and water temperature,
When using the heater, make sure that the amount of cooling water flowing into the lubricating oil cooler waterway is reduced by the amount that flows to the heater side, and make sure that the cooling water flowing to the heater is not cooled by the lubricating oil cooler. , prevents the cooling water from overcooling and improves the effectiveness of the heater, while at the same time, when the outside temperature is high,
In other words, when the oil amount is higher than the water temperature and the heater is not used, the cooling water that used to flow to the heater side flows to the lubricating oil cooler side, increasing the amount of cooling water and preventing the oil temperature from rising too high. The purpose of the present invention is to provide an engine cooling system that constantly maintains appropriate oil and water temperatures and improves engine performance.

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

Note that the same equipment as the conventional example shown in FIG. 1 is given the same reference numeral.

In the cooling channel diagram of the present invention shown in FIG.
A main cooling water channel 4K in which cooling water is forcibly circulated between the water pump 2 and the radiator 3; A heater water channel 20 is provided that branches off and rejoins the main cooling channel 4 on the suction side of the water pump 2, that is, downstream of the radiator 3 and upstream of the water pump 2, and a flow rate that is manually operated from the upstream side is provided in the heater water channel 20. A control valve 8 and a heater 9 are provided as in the conventional case.

It branches from a part downstream of the branching part of the heater waterway 20 and the main cooling waterway 4 and upstream of the flow rate control valve 8, and between the engine 1 and the thermovalve 10, that is, the main cooling waterway 4 and the heater waterway 20. downstream of the branch and water pump 2
Lubricating oil cooler waterway 3D that joins the upstream main cooling waterway 4
Furthermore, a lubricating oil cooler 7 is interposed in the water channel 30.

The passage area of the heater waterway 20 and the lubricating oil cooler waterway 30 branching from the waterway 20 is determined by the flow rate of cooling water flowing to the heater 9 side and the flow rate of cooling water flowing to the lubricating oil cooler 7 side when the heater 9 is used. Each cooling water flow rate is set to a size sufficient to ensure only the required flow rate.

As described above (the lubricating oil cooler waterway 30 is replaced with the heater waterway 20)
By providing more branches, when the outside temperature is low, the flow control valve 8 is opened to allow the cooling water to flow to the heater 9 side.
The amount of cooling water passing through is the amount required when the outside temperature is low.

Therefore, when the outside temperature is low, such as when the flow rate control valve 8 is opened to flow cooling water to the heater 9 side, the amount of cooling water flowing to the lubricating oil cooler 7 is reduced by the amount flowing to the heater 9 side. It is possible to suppress a drop in the temperature of the cooling water caused by the lubricating oil cooler 7 due to the water temperature being higher than the water temperature, and prevent a drop in the temperature of the water circulating in the main cooling channel 4, thereby improving the effectiveness of the heater. do.

On the other hand, when the outside temperature is high, such as when the flow control valve 8 is closed and the use of the heater 9 is stopped, the cooling water that had been flowing to the heater 9 side flows to the lubricating oil cooler T side, and the cooling water flowing to the lubricating oil cooler 7 The amount of water flowing through the lubricating oil increases, and since the water temperature is lower than the oil temperature at this time, the lubricating oil can be effectively cooled by the cooling water, and an excessive rise in oil temperature can be reliably prevented.

That is, 1 the present invention branches the lubricating oil cooler waterway 30 from the heater waterway 20 branched from the main cooling waterway 4, so that the amount of water flowing into the lubricating oil cooler waterway 30 influences whether the heater 7 is used or not. the heater 7.
The amount of water flowing into the lubricating oil cooler conduit 30 is automatically reduced when the outside temperature is low, that is, when the heater 7 is not used, that is, when the outside temperature is lower than the oil temperature and the water temperature. When the temperature is high, that is, when the oil temperature is higher than the water temperature, the amount of water flowing into the lubricating oil cooler waterway 30 is dynamically increased.

As described above, according to the cooling system of the present invention, it is possible to maintain appropriate water and oil temperatures regardless of changes in outside temperature simply by branching the lubricating oil cooler waterway from the heater waterway and changing the orchid pipes. can.

Therefore, since a drop in the temperature of the cooling water is prevented when the outside temperature is low, the effectiveness of the heater is improved, and an excessive rise in oil temperature when the outside temperature is warm can be prevented.

[Brief explanation of the drawing]

FIG. 1 is a circuit diagram of a cooling channel system showing a conventional example, FIG. 2 is a graph showing the relationship between oil temperature and water temperature, and FIG. 3 is a circuit diagram of a cooling channel system according to the present invention. 1...Engine, 2...Water pump, 3...
・Radiator, 4... Main cooling waterway, 7... Lubricating oil cooler, 8... Flow control valve, 9... Heater, 10...
・Thermo valve, 20... Heater waterway, 30...
Lubricating oil cooler waterway.

Claims (1)

[Claims] 1. A main cooling waterway in which cooling water circulates between the engine and the radiator, a water pump interposed between the radiator outlet of the rescue cooling waterway and the engine inlet, and a radiator inlet and the engine outlet of the main cooling waterway. A thermo-valve interposed between the thermo-valve and the heater, which branches from the main cooling water channel inside the engine downstream of the water pump and upstream of the thermo-valve, passes through the heater, and joins the main cooling water channel downstream of the radiator outlet and upstream of the water pump. Along with being equipped with an irrigation canal,
Upstream of the flow rate control valve provided upstream of the heater in the heater waterway and downstream of the branching point between the main cooling waterway and the heater waterway, the heater waterway branches off and passes through the lubricating oil cooler to form the main cooling waterway. An engine cooling system characterized in that a lubricating oil cooler waterway is provided downstream of a branching point between the water pump and the heater waterway and joins the main cooling waterway upstream of the water pump.