JP3810892B2 - Engine cooling system - Google Patents

Description

[0001]
BACKGROUND OF THE INVENTION
The present invention relates to an engine cooling device that cools an engine with cooling water of a radiator.
[0002]
[Prior art]
Generally, in an engine cooling device for an automobile, the engine is cooled by cooling water from a radiator.
[0003]
FIG. 7 shows such an engine cooling device. In this engine cooling device, an outlet pipe 3 that guides cooling water from the cylinder head 1 to the radiator 2 is arranged in the cylinder head 1 of the engine. .
On the outlet side of the radiator 2, an inlet pipe 5 that guides cooling water from the radiator 2 to the cylinder block 4 is disposed.
[0004]
A bypass pipe 6 is arranged by connecting the outlet pipe 3 and the inlet pipe 5.
The outlet pipe 3 is provided with a temperature sensing valve 7 that closes the bypass pipe 6 with the bypass valve 7b when the main valve 7a is opened.
A pump 8 that is directly driven by the engine is disposed in the inlet pipeline 5.
[0005]
In such an engine cooling device, during normal operation, the main valve 7a of the temperature sensing valve 7 is opened, the bypass pipe 6 is closed by the bypass valve 7b, and the cooling water cooled by the radiator 2 is supplied to the inlet pipe 5 After flowing into the cylinder block 4 and cooling the cylinder block 4 and the cylinder head 1, the refrigerant is circulated from the outlet pipe 3 to the radiator 2.
[0006]
On the other hand, during the warm-up operation, the main valve 7a of the temperature sensing valve 7 is closed, the bypass pipe 6 is opened by the bypass valve 7b, and the cooling water from the cylinder head 1 is supplied from the outlet pipe 3 to the bypass pipe 6, After passing through the inlet pipe 5, it flows into the cylinder block 4 and is circulated through the cylinder head 1.
[0007]
[Problems to be solved by the invention]
However, in such a conventional engine cooling device, the cooling water from the cylinder head 1 passes through the outlet pipe 3, the bypass pipe 6, the inlet pipe 5, and the cylinder block 4 during the warm-up operation, and then the cylinder head. Therefore, there is a problem that sufficient warm-up performance cannot be obtained.
[0008]
Further, since the pump 8 is always driven by the engine, there is a problem that the engine load increases.
The present invention has been made to solve such a conventional problem, and provides an engine cooling device capable of significantly improving the warm-up performance as compared with the prior art and effectively reducing the engine load. With the goal.
[0009]
[Means for Solving the Problems]
The engine cooling device according to claim 1 includes an outlet pipe that guides cooling water from the cylinder head to the radiator, a first inlet pipe that guides cooling water from the radiator to the cylinder block, the outlet pipe, and the first pipe. A bypass pipe that connects the first inlet pipe, a second inlet pipe that is branched from the bypass pipe, and the outlet pipe that is disposed by the bypass valve when the main valve is opened. A temperature sensing valve for closing the bypass line; an electric pump disposed in the second inlet line; and an outlet side of the second inlet line, wherein the cooling water flow path is disposed on the cylinder head side. A switching valve that switches to the cylinder block side and a pump that is disposed in the first inlet pipe and is driven by an engine via an electromagnetic clutch.
[0010]
The engine cooling device according to claim 2 is characterized in that, in the engine cooling device according to claim 1, the temperature sensing valve is capable of changing a valve opening temperature of the main valve to a low temperature side by energizing a heater. And
[0011]
(Function)
In the engine cooling device according to the first aspect, during the warm-up operation, first, the main valve of the temperature sensing valve is closed, the bypass valve is opened, the switching valve is opened on the cylinder head side, the electric pump is turned off, and the electromagnetic clutch is turned off. This stops the circulation of the cooling water and shortens the warm-up time.
[0012]
Next, the electric pump is turned on, and the cooling water from the cylinder head is circulated only to the cylinder head via the outlet pipe, the bypass pipe, and the second inlet pipe, while taking measures against heat spot of the cylinder head. The engine is warmed up.
Next, when the temperature of the cooling water in the cylinder block reaches the set temperature, the switching valve is opened to the cylinder block side, and the cooling water in the cylinder block is supplied to the cylinder head, the outlet pipe, the bypass pipe, and the second inlet pipe. It is circulated through the path to the cylinder block.
[0013]
During general driving when the temperature of the cooling water exceeds a predetermined temperature, the main valve of the temperature sensing valve is opened, the bypass valve is closed, the switching valve is opened on the cylinder block side, the electric pump is on, and the electromagnetic clutch is off. Thus, the cooling water is circulated to the radiator by the electric pump, and the energy required for the cooling water circulation is minimized.
Further, during idling after heat resistant running, the peak water temperature is lowered by the maximum flow rate of the electric pump.
[0014]
When the engine load is large and the maximum capacity of the electric pump exceeds the allowable water temperature of the cooling water, the electric pump is turned off and the electromagnetic clutch is turned on. The pump driven by the engine circulates the cooling water to the radiator. Is done.
In the engine cooling device according to claim 2, when the temperature sensing valve can change the valve opening temperature of the main valve to a low temperature side by energizing the heater, and the engine load is likely to increase rapidly, the energization to the heater is performed. The valve opening temperature of the main valve is changed to the low temperature side.
[0015]
DETAILED DESCRIPTION OF THE INVENTION
Hereinafter, embodiments of the present invention shown in the drawings will be described in detail.
FIG. 1 shows an embodiment of an engine cooling device according to the present invention. Reference numeral 11 denotes a cylinder of an engine having a cylinder head 13 and a cylinder block 15.
[0016]
The cylinder head 13 is provided with an outlet pipe 19 that guides cooling water from the cylinder head 13 to the inlet side of the radiator 17.
A first inlet pipe 21 that guides cooling water from the radiator 17 to the cylinder block 15 is arranged on the outlet side of the radiator 17.
A bypass pipe 23 is arranged by connecting the outlet pipe 19 and the first inlet pipe 21.
[0017]
A temperature sensitive valve 25 made of a thermostat is disposed at a branching portion of the outlet pipe 19 with the bypass pipe 23.
The temperature sensing valve 25 includes a main valve 27 that opens and closes the outlet pipe 19 toward the radiator 17, and a bypass valve 29 that opens and closes the bypass pipe 23.
The bypass pipe 29 is closed by the bypass valve 29 when the main valve 27 is opened, and the bypass pipe 23 is opened by the bypass valve 29 when the main valve 27 is closed.
[0018]
The main valve 27 is set to be opened when the temperature of the cooling water reaches 90 ° C., for example, and the temperature of the cooling water that is about 10 ° C. higher than the conventional temperature is increased.
A second inlet pipe 31 is arranged branched from the bypass pipe 23.
An electric pump 33 is disposed in the second inlet conduit 31.
[0019]
On the outlet side of the second inlet pipe 31, a switching valve 35 that switches the cooling water flow path between the cylinder head 13 side and the cylinder block 15 side is disposed.
The switching valve 35 is an electromagnetic valve having a two-system valve.
A pump 39 driven by an engine via an electromagnetic clutch 37 is disposed in the first inlet pipe 21.
[0020]
In this embodiment, the temperature sensing valve 25 can change the valve opening temperature of the main valve 27 to the low temperature side by energizing a heater (not shown).
That is, for example, the temperature sensing valve 25 disclosed in Japanese Patent Laid-Open No. 6-2076885 is used as the temperature sensing valve 25, and a heater arranged in wax in a temperature sensing case (not shown) is heated. Thus, the wax is expanded, and the valve opening temperature of the main valve 27 can be changed from 90 ° C. to 80 ° C., for example.
[0021]
Further, a pipe 41 connected to the second inlet pipe 31 is connected to the cylinder head 13, and a heater core 43 is disposed in the pipe 41.
In the above-described engine cooling device, the engine control device (not shown) energizes the heater of the temperature sensing valve 25, opens and closes the switching valve 35 to the cylinder head 13 or the cylinder block 15 side, and the electric pump. ON / OFF of 33 and ON / OFF of the electromagnetic clutch are controlled.
[0022]
In the engine cooling apparatus described above, during the warm-up operation, first, as shown in FIG. 2, the main valve 27 of the temperature sensing valve 25 is closed, the bypass valve 29 is opened, and the switching valve 35 is opened to the cylinder head 13 side. The electric pump 33 is turned off and the electromagnetic clutch 37 is turned off, whereby the circulation of the cooling water is stopped and the initial warm-up time is shortened.
Next, as shown in FIG. 3, the electric pump 33 is turned on, and the cooling water from the cylinder head 13 is supplied only to the cylinder head 13 through the outlet pipe 19, the bypass pipe 23 and the second inlet pipe 31. The engine is warmed up in the middle period while taking measures against heat spots of the cylinder head 13.
[0023]
Next, as shown in FIG. 4, when the temperature of the cooling water in the cylinder block 15 reaches the set temperature, the switching valve 35 is opened to the cylinder block 15 side, and the cooling water in the cylinder block 15 It is circulated to the cylinder block 15 through the pipe line 19, the bypass pipe line 23 and the second inlet pipe line 31, and the final warm-up is performed.
During general traveling when the temperature of the cooling water exceeds a predetermined temperature, as shown in FIG. 5, the main valve 27 of the temperature sensing valve 25 is opened, the bypass valve 29 is closed, and the switching valve 35 is moved to the cylinder block 15 side. Open, the electric pump 33 is turned on, and the electromagnetic clutch 37 is turned off, whereby the electric pump 33 circulates the cooling water to the radiator 17 and minimizes the energy required for the circulation of the cooling water.
[0024]
Further, the peak water temperature is lowered by the maximum flow rate of the electric pump 33 during idling after the heat-resistant running.
When the engine load is large and the maximum capacity of the electric pump 33 is in heat-resistant running exceeding the allowable water temperature of the cooling water, as shown in FIG. 6, the electric pump 33 is turned off and the electromagnetic clutch 37 is turned on and driven by the engine. The cooling water is circulated to the radiator 17 by the pump 39.
[0025]
Further, in the engine cooling device described above, when the engine load is likely to increase suddenly during the general running and heat resistant running shown in FIGS. 5 and 6, the heater is energized and the main valve 27 is opened. The temperature is changed from 90 ° C. to 80 ° C., for example.
In the engine cooling apparatus configured as described above, the electric pump 33 is disposed in the second inlet conduit 31, and the coolant flow path is connected to the cylinder head 13 side on the outlet side of the second inlet conduit 31. Since the switching valve 35 for switching to the cylinder block 15 side is arranged, the warm-up performance can be greatly improved as compared with the prior art.
[0026]
In addition, since the pump 39 driven by the engine via the electromagnetic clutch 37 is disposed in the first inlet pipe 21, the engine load can be effectively reduced by turning off the electromagnetic clutch 37.
Furthermore, in the engine cooling device described above, the temperature sensing valve 25 can change the valve opening temperature of the main valve 27 to the low temperature side by energizing the heater, so that when the engine load is likely to increase rapidly, By energizing the heater and changing the valve opening temperature of the main valve 27 to the low temperature side, the valve can be opened without waiting for the engine coolant temperature to rise, and the safety of the engine can be ensured. .
[0027]
【The invention's effect】
As described above, in the engine cooling device according to the first aspect, the electric pump is arranged in the second inlet pipe, and the cooling water flow path is arranged on the cylinder head side and the cylinder on the outlet side of the second inlet pipe. Since the switching valve for switching to the block side is arranged, the warm-up performance can be greatly improved as compared with the prior art.
[0028]
In addition, since the pump driven by the engine via the electromagnetic clutch is arranged in the first inlet pipe, the engine load can be effectively reduced by turning off the electromagnetic clutch.
In the engine cooling device according to the second aspect, since the temperature sensing valve can change the valve opening temperature of the main valve to the low temperature side by energizing the heater, when the engine load is likely to increase rapidly, The valve opening temperature of the main valve is changed to a low temperature side, so that the valve can be opened without waiting for the engine coolant temperature to rise, and the safety of the engine can be ensured.
[Brief description of the drawings]
FIG. 1 is a piping diagram showing an embodiment of an engine cooling device of the present invention.
2 is a piping system diagram showing an initial state of warm-up running in the engine cooling device of FIG. 1. FIG.
3 is a piping system diagram showing a middle state of warm-up running in the engine cooling device of FIG. 1; FIG.
4 is a piping system diagram showing a final state of warm-up running in the engine cooling device of FIG. 1. FIG.
FIG. 5 is a piping system diagram showing a general running state in the engine cooling device of FIG. 1;
6 is a piping system diagram showing a heat-resistant running state in the engine cooling device of FIG. 1. FIG.
FIG. 7 is a piping system diagram showing a conventional engine cooling device.
[Explanation of symbols]
13 Cylinder Head 15 Cylinder Block 17 Radiator 19 Outlet Line 21 First Inlet Line 23 Bypass Line 25 Temperature Sensing Valve 27 Main Valve 29 Bypass Valve 31 Second Inlet Line 33 Electric Pump 35 Switching Valve 37 Electromagnetic Clutch 39 pump

Claims (2)

An outlet pipe (19) for guiding cooling water from the cylinder head (13) to the radiator (17);
A first inlet pipe (21) for guiding cooling water from the radiator (17) to the cylinder block (15);
A bypass line (23) connecting the outlet line (19) and the first inlet line (21);
A second inlet line (31) arranged branched from the bypass line (23);
A temperature sensitive valve (25) disposed in the outlet pipe (19) and closing the bypass pipe (23) by a bypass valve (29) when the main valve (27) is opened;
An electric pump (33) disposed in the second inlet line (31);
A switching valve (35) disposed on the outlet side of the second inlet pipe (31) and switching the flow path of the cooling water between the cylinder head (13) side and the cylinder block (15) side;
A pump (39) disposed in the first inlet line (21) and driven by an engine via an electromagnetic clutch (37);
An engine cooling device comprising: The engine cooling device according to claim 1.
The engine cooling device characterized in that the temperature sensing valve (25) can change the valve opening temperature of the main valve (27) to a low temperature side by energizing a heater.

Images