JP2014070501A - Oil cooling structure - Google Patents

Abstract

PROBLEM TO BE SOLVED: To solve a problem such that temperature of oil used in a speed change gear is low and fuel efficiency is reduced due to a friction loss in starting an engine.SOLUTION: An oil cooling structure has: a water outlet pipe connected to a cooling water intake port of a water jacket of an engine; a thermostat for opening and closing the cooling water intake port; a water inlet pipe connected to a cooling water exhaust port of the water jacket; an upper tank communicated with the water inlet pipe; a radiator core communicated with the upper tank; a lower tank communicated with the radiator core and communicated with the water outlet pipe; an oil cooler provided inside the lower tank and cooling oil of a speed change gear; a bypass pipe directly communicated with the lower tank from the water inlet pipe; and a thermo-valve provided in the water inlet pipe and switching a flow passage to the bypass pipe. Under not more than temperature at which the thermostat is fully opened, the flow passage is switched to the bypass pipe.

Description

  The present invention relates to an oil cooling structure for cooling hydraulic oil (oil) used in a transmission of an automobile.

  The transmission of an automobile generates friction because mechanical parts are engaged with each other and driven. Oil is used to reduce this friction. Since the oil is made so as to obtain the most effect when the transmission is operating steadily, it does not work effectively when the temperature is low such as at the time of starting. As a result, the friction increases at the time of starting, causing deterioration of fuel consumption.

  On the other hand, since oil deteriorates or lowers its lubricating ability even if the temperature rises too much, it must be cooled to an oil temperature below a certain level. Oil cooling is performed by an oil cooler. Many oil coolers are built into the engine radiator. Therefore, if cooling water is circulating through the radiator when the engine is started, the oil is cooled and the oil cannot be warmed up.

  That is, at the time of starting the engine, it is preferable from the viewpoint of reducing the friction that the oil temperature quickly rises, and once the temperature rises, it is cooled so that it is not further heated.

  Patent Document 1 discloses an invention in which a bypass pipe is provided between a feed pipe and a return pipe of an oil cooler. That is, when the oil at the time of starting the engine is low temperature, the oil is not sent to the oil cooler, and the oil is prevented from being cooled by the oil cooler.

  Patent Document 2 discloses an invention in which the cooling water is not sent to the oil cooler at the start-up, and a heating wire is provided in the oil cooler to warm the oil cooler at the start-up.

JP-A-10-231727 JP 2007-16857 A

  Increasing the oil temperature as soon as possible when starting the engine reduces the friction, resulting in improved fuel efficiency. The method of Patent Document 1 is preferable in that it prevents oil from being cooled during startup. However, since the transmission basically has no internal combustion mechanism like the engine, the oil temperature rises due to the frictional heat of the transmission itself. Therefore, it is difficult to raise the oil temperature in the early period after starting.

  In Patent Document 2, since cold oil at the time of starting is warmed by a heater, it may be possible to raise the oil temperature in an early period. However, it is necessary to separately provide a heater having a heat capacity sufficient to warm up the oil at an early stage, which increases power consumption. In the case of an automobile, the power source has a limited capacity. Especially when starting in cold regions, the use of extra power as much as possible should be avoided. This is because an excessive load is applied to the battery.

  In view of the above-described problems, the present invention provides an oil cooling structure that makes it possible to increase the oil temperature at an early stage by effectively using the heat obtained from the engine as much as possible.

More specifically, the oil cooling structure of the present invention is
An oil cooling structure for cooling the transmission oil,
A drain pipe connected to the cooling water intake of the engine water jacket;
A thermostat for opening and closing the cooling water inlet;
A water inlet pipe connected to the cooling water outlet of the water jacket;
An upper tank communicating with the water inlet pipe;
A radiator core communicating with the upper tank;
A lower tank that communicates with the radiator core and communicates with the drain pipe;
An oil cooler installed in the lower tank for cooling the transmission oil;
A bypass pipe directly communicating with the lower tank from the water inlet pipe;
A thermo valve installed in the water inlet pipe and switching the flow path to the bypass pipe;
When the thermostat is below the temperature at which the cooling water intake is fully opened,
The thermo valve switches the flow path to the bypass pipe.

  In the present invention, when the oil cooler is arranged in the lower tank of the radiator, the cooling water from the warm engine is directly supplied to the lower tank. Since the engine burns fuel in the cylinder, it is a large heat source, and the water temperature in the water jacket rises quickly in a short time. The oil cooler is warmed with the warmed cooling water. Thus, the oil can be warmed in a short time after startup.

  In addition, since warm water produced by the engine is used, a battery having a large heat capacity is not used, and the battery is not burdened.

It is a figure showing composition of an oil cooling structure concerning the present invention, and a thermovalve shows a fully closed state. It is a figure which shows a thermo valve in a fine open state. It is a figure which shows a thermo valve in a fully open state.

  The structure of the exhaust pipe according to the present invention will be described below with reference to the drawings. The following description exemplifies an embodiment of the present invention, and changes within the scope of the present invention are included in the technical scope of the present invention without departing from the spirit of the present invention. Needless to say.

  FIG. 1 shows a configuration of an oil cooling structure 1 according to the present invention. The oil cooling structure 1 includes an engine water jacket 10, a radiator 12, and an oil cooler 16 disposed in a lower tank 15 of the radiator 12. The water jacket 10 is a space arranged around the cylinder head 9 and the cylinder block 8 for cooling them. A cooling water inlet 10in and a cooling water outlet 10out are provided.

  In the water jacket 10, a flow path 10p is provided from the cooling water intake 10in to the cooling water discharge port 10out. The cooling water sent from the cooling water inlet 10in flows along the flow path 10p, and is finally discharged from the cooling water discharge port 10out while cooling each part of the engine.

  Further, the water jacket 10 is provided with a thermostat 11 for switching whether or not the cooling water from the radiator 12 is taken into the cooling water intake 10 in depending on the temperature of the cooling water. When the coolant temperature is low, the thermostat 11 completely closes the coolant inlet 10in so that the coolant does not flow to the radiator 12.

  Therefore, when the engine is started, the cooling water is not sent to the radiator 12, but only circulates in the water jacket 10, so that the temperature of the cooling water can be quickly raised. The thermostat 11 has at least three open / close modes depending on the water temperature: fully closed, slightly opened, and fully opened. “Fully closed” means that the cooling water intake 10 in is completely closed and the cooling water is circulated only in the water jacket 10.

  “Slightly open” means that a part of the cooling water in the water jacket 10 is sent to the radiator 12 when the cooling water temperature rises slightly. In other words, cold cooling water from the radiator 12 is taken into the water jacket 10. “Fully open” means that the cooling water path to the radiator 12 is fully opened. As a result, most of the cooling water that has passed through the flow path 10 p in the water jacket 10 is sent to the radiator 12.

  An impeller (water pump) 10m that is rotationally driven is provided so that the cooling water flows along the flow path 10p. The water jacket 10 may be provided with a heater core 7. The heater core 7 is an apparatus that uses the cooling water whose temperature has been increased by cooling the engine as a heat source.

  The radiator 12 includes an upper tank 13, a radiator core 14, and a lower tank 15. The upper tank 13, the radiator core 14, and the lower tank 15 communicate with each other. That is, the cooling water stored in the upper tank 13 flows to the radiator core 14, and the cooling water that flows through the radiator core 14 is stored in the lower tank 15.

  The upper tank 13 is connected to a water intake pipe 21 that communicates with the cooling water discharge port 10out of the water jacket 10. Further, the lower tank 15 communicates with a water discharge pipe 22 that communicates with the cooling water intake 10 in of the water jacket 10.

  An oil cooler 16 is also disposed in the lower tank 15. The oil cooler 16 communicates with the transmission unit 6 through an oil feeding pipe 6out and an oil receiving pipe 6in. That is, from the transmission unit 6, oil is sent to the oil cooler 16 through the oil feed pipe 6out, and returns through the oil receiving pipe 6in.

  An oil bypass pipe 6b is provided between the oil receiving pipe 6in and the oil feeding pipe 6out. The oil bypass pipe 6b is provided with an oil thermostat 6t. The oil thermostat 6t switches whether oil flows from the transmission unit 6 to the oil cooler 16 or the oil bypass pipe 6b. The oil that has flowed through the oil bypass pipe 6 b does not go to the oil cooler 16 and returns to the transmission unit 6 as it is.

  The oil thermostat 6t operates in conjunction with the movement of the thermostat 11. When the thermostat 11 is fully closed, oil flows through the oil bypass pipe 6b. When the thermostat 11 is slightly opened or fully opened, oil is passed through the oil cooler 16.

  A branch pipe is disposed on the water jacket 10 side of the inlet pipe 21 from the inlet 13 a to the upper tank 13. The branch pipe communicates directly with the lower tank 15 without passing through the radiator core 14. This branch pipe is called a bypass pipe 25. A thermo valve 26 for switching the flow path between the water inlet 21 and the bypass pipe 25 is provided inside the water inlet 21 at the connection portion between the water inlet 21 and the bypass 25.

  The thermo valve 26 switches the flow path to the bypass pipe 25 when the engine is started and when the thermostat 11 is below the water temperature at which the thermostat 11 is fully opened. Once the thermostat 11 is fully opened, the flow path is maintained in the inlet pipe 21 until the temperature of the cooling water cools thereafter.

  Here, when the engine is started, it means a period from about several minutes to several tens of minutes from when the engine is started from the stopped state to when warm-up is completed. However, the case where the temperature of the cooling water is equal to or lower than a predetermined temperature may be included regardless of whether the engine is operating. That is, even immediately after starting from the engine stop state, when the temperature of the cooling water is equal to or higher than the predetermined temperature, it is not necessary to call it when starting the engine.

  The operation of the oil cooling structure 1 having the above configuration will be described below. Assume that the car is stopped and the engine is cold enough. When the engine is started, the cooling water in the water jacket 10 is also cooled. The thermostat 11 is “fully closed”. Further, the thermo valve 26 allows the water inlet pipe 21 and the upper tank 13 to communicate with each other. The oil thermostat 6t sets a flow path so that oil passes through the oil bypass pipe 6b. When the engine is started, the impeller 10m rotates and the cooling water flows through the flow path 10p in the water jacket 10.

  Since the thermostat 11 is fully closed, the cooling water in the water jacket 10 circulates only in the water jacket 10 according to the flow path 10p. Since the engine burns fuel and generates high heat, the temperature of the cooling water immediately rises. At this time, the oil in the transmission unit 6 passes through the oil bypass pipe 6b and is not sent to the oil cooler 16.

  FIG. 2 shows a state where the thermostat 11 is “slightly opened”. When the thermostat 11 is in the “slightly open” state due to the rise in the coolant temperature, warm coolant in the water jacket 10 flows from the coolant outlet 10out toward the radiator 12 through the water inlet 21. With this warm cooling water, the thermo valve 26 switches the flow path to the bypass pipe 25 side. This warm cooling water flows through the bypass pipe 25 and flows to the lower tank 15. When the thermo valve 26 switches the flow path to the bypass pipe 25, the oil thermostat 6t changes the flow path so that oil flows to the oil cooler 16 side.

  Since the oil cooler 16 is installed in the lower tank 15, the warm cooling water warms the oil cooler 16. Since the oil from the transmission unit 6 flows through the oil cooler 16, the oil is warmed by the oil cooler 16 and returned to the transmission unit 6. In this manner, the oil in the transmission unit 6 can be warmed before the warm-up operation after the engine is started. As a result, friction generated in the transmission unit 6 can be reduced.

  In addition, when the temperature of the cooling water in the water jacket 10 further increases, the thermostat 11 is in the “fully open” state. FIG. 3 shows the situation at this time. The thermo valve 26 switches the flow path from the bypass pipe 25 to the water inlet pipe 21 at this timing. By doing so, the heated cooling water is sent to the upper tank 13 and stored. The cooling water in the upper tank 13 passes through a thin tube of the radiator core 14 and is heat-exchanged to become cooled cooling water.

  The cooled cooling water flows into the lower tank 15 and cools the oil cooler 16. And it returns to the water jacket 10 through the water discharge pipe 22 again. Since the oil thermostat 6t is interlocked with the movement of the thermostat 11, the flow path is set so that the oil flows to the oil cooler 16 side unless the thermostat 11 is closed.

  The thermo valve 26 that once switched the flow path to the water inlet pipe 21 maintains the flow path in the water inlet pipe 21 until the coolant temperature reaches a predetermined temperature such as room temperature. This is because even when the engine is started, while the engine is warm, the oil is considered to be within a predetermined range, and it is not necessary to warm the oil cooler 16 again.

  In the above embodiment, the thermo valve 26 has been described so as to detect and open the water temperature itself. However, a water temperature sensor in the water inlet 21 is prepared, and a control device or the like is prepared according to the water temperature in the water inlet 21. You may make it switch a valve from. That is, the thermo valve 26 does not exclude a configuration other than a single component. Further, the oil thermostat 6t may be constituted by a solenoid valve, and the opening / closing control may be performed according to the oil temperature of the transmission unit 6.

  The present invention can be suitably used for cooling oil used in an automobile transmission. In particular, it can be easily used for a vehicle having a cooling system of a type in which an oil cooler is built in the radiator.

DESCRIPTION OF SYMBOLS 1 Oil cooling structure 6 Transmission unit 6b Oil bypass pipe 6t Oil thermostat 6in Oil receiving pipe 6out Oil feeding pipe 7 Heater core 8 Cylinder block 8in Oil receiving pipe 8out Oil feeding pipe 9 Cylinder head 10 Water jacket 10in Cooling water inlet 10out Cooling water outlet 10p Flow Road 10m Impeller 11 Thermostat 12 Radiator 13 Upper tank 13a (Upper tank) inlet 14 Radiator core 15 Lower tank 16 Oil cooler 21 Inlet pipe 22 Outlet pipe 25 Bypass pipe 26 Thermo valve

Claims (1)

An oil cooling structure for cooling the transmission oil,
A drain pipe connected to the cooling water intake of the engine water jacket;
A thermostat for opening and closing the cooling water inlet;
A water inlet pipe connected to the cooling water outlet of the water jacket;
An upper tank communicating with the water inlet pipe;
A radiator core communicating with the upper tank;
A lower tank that communicates with the radiator core and communicates with the drain pipe;
An oil cooler installed in the lower tank for cooling the transmission oil;
A bypass pipe directly communicating with the lower tank from the water inlet pipe;
A thermo valve installed in the water inlet pipe and switching the flow path to the bypass pipe;
When the thermostat is below the temperature at which the cooling water intake is fully opened,
The oil cooling structure, wherein the thermo valve switches the flow path to the bypass pipe.