JP2008240527A - Engine cooling device - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To suppress poor lubrication of a sliding portion of a water pump in an engine cooling device. <P>SOLUTION: In the cooling device 1 for the engine 2, the water pump 13 is arranged under the lower end of a water jacket 6 so that the sliding portion 13a of the water pump 13 is immersed in cooling water. A first valve 12 is closed to form a cooling water reservoir, whereby the sliding portion 13a of the water pump 13 is well lubricated. <P>COPYRIGHT: (C)2009,JPO&INPIT

Description

  The present invention relates to an engine cooling apparatus.

  Conventionally, cooling water pumped by a water pump in a cooling device for an engine is sent to a part such as a cylinder block or a cylinder head that requires cooling, and takes heat from such a cooling part. The cooling water that has taken heat from the cooling site is sent to the radiator, and the radiator releases heat into the atmosphere. As described above, the engine is cooled by heat exchange of the cooling water circulating in the engine. Such an engine that circulates cooling water is configured to reduce heat release by switching the flow path so that the cooling water does not flow into the radiator during warm-up.

  However, since the water jacket of such an engine cooling device is always filled with cooling water, the engine warms the cooling water in the system together with the cylinder block and the cylinder head when warming up. It took time. With respect to such a problem, in the engine cooling device disclosed in Patent Document 1, the cooling water in the engine body is extracted during the warm-up operation, and the level of the cooling water in the water jacket is lowered to correspond to the cooling water. When the heat capacity is reduced and the warm-up is completed, the cooling water is returned to the water jacket again. In such an engine, since the heat capacity corresponding to the cooling water is reduced, an effect of shortening the warm-up time is obtained as compared with an engine that does not extract the cooling water.

Japanese Utility Model Publication No. 3-26255

  By the way, there is a type of water pump that forms a thin liquid film on a sliding surface and seals it. The engine cooling device provided with such a water pump uses the cooling water as a lubricant to lubricate the sliding portion of the water pump. However, in the engine cooling device as disclosed in Patent Document 1, since the cooling water is extracted from the water jacket, the cooling water in the water pump is reduced and the cooling water is not supplied to the sliding portion of the water pump. Sometimes. Further, since such a water pump is driven by the rotation of the crankshaft, it continues to be driven unless the engine is stopped while the cooling water is extracted from the water jacket. In such a situation, the water pump sliding part is operated in a dry state without water, and heat is generated, and as a result, the sliding surface becomes rough and seized, causing water leakage and damage. There is a risk.

  Then, this invention makes it a subject to suppress the lubricous defect in the sliding part of the water pump in an engine cooling device.

  The engine cooling apparatus of the present invention that solves this problem is characterized in that the water pump is disposed so that the sliding portion of the water pump is immersed in the cooling water. By adopting such a configuration, the sliding portion of the water pump is immersed in the cooling water and is not operated in a dry state, and a good lubricating state is maintained.

  An engine cooling device capable of obtaining the same effect as such an engine cooling device includes a tank for storing cooling water extracted from the water jacket, and when the cooling water is extracted from the water jacket to the tank. The water pump can be arranged so that the sliding portion of the water pump is immersed in the cooling water (claim 2). Also, an engine cooling device (Claim 3) in which the water pump is arranged so that the sliding portion of the water pump is positioned below the coolant level, or the sliding portion of the water pump is provided in the engine. The engine cooling device (Claim 4) in which the water pump is arranged so as to be positioned below the lower end of the formed water jacket can achieve the same effect. In addition, these engine cooling devices can be configured to include a cooling water pool forming means below the sliding portion of the water pump.

  Further, an engine cooling device for the purpose of good lubrication of the sliding portion of the water pump is separated from a water jacket formed in the engine so that a closed circuit of cooling water including the water pump is formed. (Claim 6). With such a configuration, in an engine in which cooling water is extracted from the water jacket during warm-up, the cooling water circulates through the water pump even when the cooling water is extracted from the water jacket. For this reason, since the sliding part of a water pump is immersed in cooling water, it is not operated in a dry state and good lubrication is maintained.

  Such a cooling device for an engine can be configured to include a closed circuit constructing unit that forms a closed circuit for cooling water including a water pump by being separated from a water jacket formed in the engine. ). Further, such an engine cooling device includes a closed circuit construction unit that forms a closed circuit including a water pump by being separated from a water jacket formed in the engine, and the closed circuit construction unit includes the water pump of the water pump. A first switching valve disposed on the downstream side, a second switching valve disposed on the upstream side of the water pump, and a connection path connecting the first switching valve and the second switching valve. (Claim 8).

  The engine cooling device of the present invention can maintain a good lubrication state of the sliding portion of the water pump by adopting a configuration in which the sliding portion of the water pump is immersed in the cooling water.

  Hereinafter, the best mode for carrying out the present invention will be described in detail with reference to the drawings.

  Embodiment 1 of the present invention will be described with reference to the drawings. The cooling device 1 incorporated in the engine 2 of this embodiment is configured to improve the warm-up performance of the engine 2 by transferring cooling water between a water jacket 6 and a tank 7 formed in the engine body 3. It has become. FIG. 1 is an explanatory diagram showing the state of supply of cooling water to the water jacket 6 before the engine 2 is started and after being warmed up. FIG. 1A shows a state before starting the engine 2 (“pre-starting” state), and FIG. 1B shows a state in which the engine 2 is started and cooling water is supplied from the tank 7 to the water jacket 6. ("Water supply" state). FIG. 1C shows a state where the cooling water is extracted from the water jacket 6 to the tank 7 after the engine 2 is started (“drainage” state). Further, FIG. 1 (d) shows a state in which the cooling water is being supplied again from the tank 7 to the water jacket 6 (“re-watering” state), and FIG. 1 (e) is after the engine 2 has been warmed up. ("After warming up" state). Below, the outline of the transfer of the cooling water between the water jacket 6 and the tank 7 is demonstrated.

  When the engine 2 is stopped during the pre-operation, the cooling water in the water jacket 6 that has become hot due to the operation of the engine 2 is transferred to the tank 7. The transferred cooling water is kept warm in the tank 7 until the next engine start. Therefore, in the “before start” state before the start of starting, as shown in FIG. 1A, the cooling water is stored in the tank 7, and the water jacket 6 is almost empty.

  Next, when the ignition is turned on at the engine start stage, the cooling device 1 shifts to the “water supply” state shown in FIG. In this “water supply” state, the cooling water in the tank 7 is supplied to the water jacket 6. Thereby, the high-temperature cooling water kept warm in the tank 7 raises the temperature of the engine body 3.

  When the cooling water is transferred from the tank 7 to the water jacket 6 in the “water supply” state, the engine 2 starts and warms up. When the ECU 19 described later determines that the temperature of the cylinder head 4 and the cylinder block 5 constituting the engine body 3 is equal to or higher than the temperature of the cooling water by various sensors (not shown) of the engine, the “drainage” shown in FIG. Transition to the state. In the “drainage” state, the cooling water is drained from the water jacket 6 to the tank 7.

  When the warming-up is completed, the cooling device 1 shifts to the “re-water supply” state shown in FIG. 1 (d), and supplies the cooling water in the tank 7 to the water jacket 6 again.

  When the inside of the water jacket 6 is filled with cooling water in the “re-water supply” state, the cooling device 1 then shifts to the “after warm-up” state shown in FIG. When the cooling device 1 is in the “after warm-up” state, the cooled cooling water circulates in the engine 2 and the engine body 3 is cooled to a temperature suitable for the operating state.

  Next, the configuration of the engine 2 incorporating the cooling device 1 for transferring the cooling water between the water jacket 6 and the tank 7 will be described. FIG. 2 is an explanatory diagram showing a schematic configuration of the engine 2 incorporating the cooling device 1 of the present embodiment. The engine body 3 includes a cylinder head 4 and a cylinder block 5, and a water jacket 6 is formed inside the cylinder head 4 and the cylinder block 5.

  The cooling device 1 includes a tank 7 having a volume capable of accommodating the cooling water in the water jacket 6. The tank 7 has a heat storage structure and is disposed below the engine body 3. The water jacket 6 and the tank 7 communicate with each other through two paths, a first path 8 and a second path 9. One end of the first path 8 is connected to the bottom of the water jacket 6, and the other end is connected to the bottom of the tank 7. One end of the second path 9 is connected to the bottom of the water jacket 6, and the other end is connected to the top of the tank 7. In the first path 8, an electric pump 10, a three-way valve 11, a first valve 12, and a water pump 13 are disposed in order from the tank 7 side, and a second valve 14 is disposed in the second path 9. In the cooling device 1, a path through which the cooling water flows from the tank 7 toward the water jacket 6 is the first path 8, and a path through which the cooling water flows from the water jacket 6 toward the tank 7 is the second path 9.

  The water pump 13 is a mechanical pump that pumps cooling water by rotation of an impeller (not shown), and pumps cooling water from the tank 7 to the water jacket 6 by using a crankshaft (not shown) as a drive source. The sliding part 13a of the water pump 13 forms a so-called mechanical seal. Further, the water pump 13 is arranged such that the sliding portion 13 a of the water pump 13 is positioned below the lower end of the water jacket 6.

  The first valve 12 is disposed below the water pump 13 and can block the flow of the cooling water in the first path. The first valve 12 corresponds to the cooling water pool forming means of the present invention.

  The electric pump 10 is a pump that assists the water pump 13 that pumps cooling water from the tank 7 to the water jacket 6, and is disposed at the lower end of the tank 7. That is, the cooling water in the tank 7 pumped out by the electric pump 10 is supplied to the water pump 13, and the cooling water is pumped from there to the water jacket 6. The three-way valve 11 switches between a path connecting the electric pump 10 and the first valve 12 and a path connecting the radiator 15 and the first valve 12 described later. The second valve 14 can block the flow of the cooling water in the second path 9.

  In addition, the cooling device 1 includes a radiator 15, and the radiator 15 is connected to the three-way valve 11 through a third path 16. Furthermore, the cooling device 1 includes a fourth path 17, one end of the fourth path 17 is connected to the cylinder head 4 side of the water jacket 6, and the other end is between the radiator 15 and the three-way valve 11 of the third path 16. Connected. A thermostat 18 is disposed in the fourth path 17. The thermostat 18 is a three-way valve that changes the flow path when the temperature of the cooling water reaches a temperature at which the warm-up is completed. The thermostat 18 is a path that connects the water jacket 6 and the radiator 15 to the water jacket 6 and the third. The path connecting the path 16 is switched.

  In addition, the cooling device 1 includes an ECU (Electronic Control Unit) 19. The ECU 19 is electrically connected to the electric pump 10, the three-way valve 11, the first valve 12, and the second valve 14. The ECU 19 drives the electric pump 10, changes the path of the three-way valve 11, The opening and closing of the two valve 14 is controlled.

  Next, the arrangement of the water pump 13 will be described in detail while showing the operation of the cooling device 1 when the cooling water of the water jacket 6 is extracted to the tank 7. FIG. 3 is an explanatory diagram showing a schematic configuration of the engine 2 incorporating the cooling device 1 when cooling water is extracted from the water jacket 6 to the tank 7. In addition, the path | route shown with the broken line in FIG. 3 has shown that the cooling water is not distribute | circulating.

  When extracting from the water jacket 6 to the tank 7, the ECU 19 of the cooling device 1 stops the electric pump 10 and stops the pumping of the cooling water from the tank 7 to the water jacket 6. Further, the ECU 19 closes the first valve 12. Thereby, the inflow of the cooling water from the tank 7 to the water jacket 6 is blocked. Further, the ECU 19 opens the second valve 14. As shown by A in FIG. 3, the water pump 13 is arranged so that the sliding portion 13a is positioned below the lower end of the water jacket 6, so that the cooling water in the water jacket 6 is freed by the free fall. It flows into the tank 7 through the two paths 9. In this way, the cooling water in the water jacket 6 is extracted to the tank 7.

  Further, when the cooling water is extracted from the water jacket 6 to the tank 7, the water pump 13 is configured such that the sliding portion 13 a of the water pump 13 is lower than the level of the cooling water in the tank 7 as shown by B in FIG. 3. It arrange | positions so that it may be located below. That is, when the cooling water is extracted from the water jacket 6 to the tank 7, the water pump 13 is disposed so that the sliding portion 13a of the water pump 13 is immersed in the cooling water.

  Further, since the cooling device 1 closes the first valve 12, the cooling water flowing to the tank 7 side through the first path 8 is blocked by free fall, and a cooling water pool is formed above the first valve 12. Since the cooling water is stored in the cooling water pool and the sliding portion 13a of the water pump 13 is immersed in the cooling water, the sliding portion 13a of the water pump 13 does not become dry and the lubrication of the sliding portion 13a is maintained. Is done.

  Thus, the water pump 13 is arranged so that the sliding portion 13a of the water pump 13 is located below the lower end of the water jacket 6, and the first valve 12 that is closed to form a cooling water pool is used as the water pump. By being arranged below 13, lubrication of the sliding portion 13a is maintained.

  Next, Embodiment 2 of the present invention will be described with reference to the drawings. FIG. 4 is an explanatory diagram showing a schematic configuration of the engine 22 incorporating the cooling device 21 of the present embodiment. The cooling device 21 has substantially the same configuration as that of the cooling device 1 of the first embodiment, except that the first switching valve 23 is disposed instead of the first valve 12 and between the water pump 13 and the water jacket 6. The second switching valve 24 is different from the first switching valve 24 in that the connection path 25 connecting the first switching valve 23 and the second switching valve 24 is provided. The first switching valve 23 is a three-way valve that switches between a path through which cooling water flows from the three-way valve 11 to the water pump 13 and a path through which cooling water flows from the connection path 25 to the water pump 13. The second switching valve 24 is a three-way valve that switches between a path through which cooling water flows from the water pump 13 to the water jacket 6 and a path through which cooling water flows from the water pump 13 to the connection path 25. The first switching valve 23, the second switching valve 24, and the connection path 25 correspond to the closed circuit construction means of the present invention. The first switching valve 23 and the second switching valve 24 are electrically connected to the ECU 19 and change the flow path according to a signal from the ECU 19. In addition, the path | route shown with the broken line in FIG. 4 has shown that the cooling water is not distribute | circulating. In addition, since the other configuration is the same as that of the first embodiment, the same components as those of the first embodiment are denoted by the same reference numerals in the drawings, and detailed description thereof is omitted.

  The cooling device 21 of the engine 22 of this embodiment extracts the cooling water from the water jacket 6 to the tank 7 as in the first embodiment, and promotes warm-up. Hereinafter, the cooling device 21 in a state where the cooling water is extracted from the water jacket 6 to the tank 7 will be described. In a state where the cooling water is extracted from the water jacket 6 to the tank 7, the first switching valve 23 forms a path through which the cooling water flows from the connection path 25 to the water pump 13 based on a command signal from the ECU 19. The second switching valve 24 forms a path through which cooling water flows from the water pump 13 to the connection path 25 based on a command signal from the ECU 19. By forming the path in this way, a closed circuit including the water pump 13 is constructed. The ECU 19 sends a command signal for switching the flow path when cooling water is in the water pump 13. As a result, the cooling water flows and circulates in the closed circuit. Thus, since the cooling water circulates in the closed circuit including the water pump 13, the sliding portion 13a of the water pump 13 is immersed in the cooling water and is well lubricated.

  In the cooling device for constructing such a closed circuit including the water pump, the closed circuit including the cooling water is constructed so that the cooling water can be immersed in the sliding portion of the water pump. It can also arrange | position above a lower end part.

  The above-described embodiments are merely examples for carrying out the present invention, and the present invention is not limited thereto. Various modifications of these embodiments are within the scope of the present invention. It is apparent from the above description that various other embodiments are possible within the scope.

  The cooling device of this invention should just have arrange | positioned the water pump so that the sliding part of a water pump may be immersed in cooling water. For engines that draw cooling water from the water jacket to the tank, when the cooling water is drawn from the water jacket to the tank, if the water pump sliding part is below the cooling water level, the sliding part is used as cooling water. Can be soaked. For example, in an engine cooling device that extracts a part of the cooling water in the water jacket, if the water pump sliding part is below the water level in the water jacket after the cooling water has been transferred to the tank, the water pump Since the sliding portion is submerged in water, the sliding portion can be kept lubricated. In addition, the cooling device of the present invention is not limited to that provided in an engine that extracts cooling water from a water jacket to a tank.

It is explanatory drawing which showed the supply state of the cooling water between the water jacket and tank after a warming-up before engine starting, (a) shows a "before start" state, (b) shows "water supply" (C) shows a “drainage” state, (d) shows a “re-water supply” state, and (e) is an explanatory view showing a “after warm-up” state. It is explanatory drawing which showed schematic structure of the engine incorporating the cooling device of Example 1. FIG. It is explanatory drawing which showed schematic structure of the engine incorporating the cooling device which extracted the cooling water from the water jacket to the tank. It is explanatory drawing which showed schematic structure of the engine incorporating the cooling device of Example 2. FIG.

Explanation of symbols

DESCRIPTION OF SYMBOLS 1,21 Engine 2,22 Cooling device 3 Engine main body 6 Water jacket 7 Tank 10 Electric pump 12 First valve 13 Water pump 13a Sliding part 14 Second valve 15 Radiator 19 ECU
23 First switching valve 24 Second switching valve 25 Connection path

Claims (8)

An engine cooling apparatus, wherein the water pump is disposed so that a sliding portion of the water pump is immersed in cooling water. It has a tank to store the cooling water extracted from the water jacket,
An engine cooling apparatus, wherein the water pump is arranged so that a sliding portion of the water pump is immersed in the cooling water when the cooling water is extracted from the water jacket to the tank. An engine cooling apparatus, wherein the water pump is arranged so that a sliding portion of the water pump is positioned below a coolant level. An engine cooling apparatus, wherein the water pump is arranged so that a sliding portion of the water pump is positioned below a lower end of a water jacket formed in the engine. The engine cooling device according to any one of claims 1 to 4,
A cooling device for an engine, comprising cooling water pool forming means below a sliding portion of the water pump. A cooling system for an engine, which is divided from a water jacket formed in the engine to form a closed circuit of cooling water including a water pump. A cooling apparatus for an engine, comprising: a closed circuit construction means for separating a water jacket formed in the engine and forming a closed circuit of cooling water including a water pump. A closed circuit construction means for dividing a water jacket formed in the engine and forming a closed circuit including a water pump;
The closed circuit construction means includes a first switching valve disposed on the upstream side of the water pump, a second switching valve disposed on the downstream side of the water pump, a first switching valve, and a second switching valve. An engine cooling device comprising a connection path for connection.

Images