JP2012132379A - Engine cooling water device - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide an engine cooling water device that effectively improves fuel consumption, while promoting engine warming-up.SOLUTION: The engine cooling water device includes: a cooling water circuit 13, 15 and 16 circulating cooling water between an engine 10 and a radiator 14; a bypass flow path 17 detouring cooling water from the radiator 14; a flow path switching means 18 switching the flow path of the cooing water to the bypass flow path 17 when a temperature of cooling water is not more than a predetermined one; a heat exchanger 19 making heat exchange between engine lubricating oil and the cooling water; an electric water pump 20 for pressure sending and supplying of the cooling water; and a controlling means 40 controlling the water pump 20 to repeat stopping and driving when the engine is warmed up.

Description

  The present invention relates to an engine cooling water device, and more particularly to an engine cooling water device including an electric water pump.

  In general, an engine cooling water device is provided with a bypass flow path that bypasses cooling water flowing out from the engine from the radiator in a cooling water circuit that circulates the cooling water between the engine and the radiator. When the engine is warming up, the engine is warmed up by closing the thermostat and allowing the coolant to flow through the bypass passage.

  For example, Patent Document 1 discloses cooling in which cooling water is circulated between a cylinder head and a cylinder block when the engine is cold, and cooling water is circulated between the cylinder head, the cylinder block, and a radiator when the engine is warm and heavy. A water device is disclosed.

Japanese Patent Application Laid-Open No. 2004-270652

  By the way, when the engine is warming up, the engine oil that lubricates the sliding portions in the engine is in a low temperature state. Therefore, the viscosity of the engine oil is increased, and the friction of each sliding portion is increased, so that the fuel efficiency of the engine is deteriorated.

  Further, since the coolant temperature is low at the start of warm-up, the combustion chamber temperature of the engine also decreases. For this reason, the amount of HC and CO in the exhaust gas increases, and exhaust emission may be deteriorated.

  The present invention has been made in view of the above points, and an object thereof is to effectively improve fuel efficiency while promoting warm-up of the engine.

  In order to achieve the above object, an engine cooling water device according to the present invention includes a cooling water circuit that circulates cooling water between an engine and a radiator, and a bypass that bypasses the cooling water circulating through the cooling water circuit from the radiator. When the temperature of the cooling water circulating through the cooling water circuit is equal to or lower than a predetermined temperature, the cooling water circuit is provided with channel switching means for switching the cooling water channel to the bypass channel, A heat exchanging section for exchanging heat between the lubricating oil of the engine and cooling water; an electric water pump provided in the cooling water circuit for supplying the cooling water by pressure; and a control means for controlling driving of the electric water pump; The control means controls the electric water pump so that the electric water pump repeatedly stops and drives when the engine is warming up.

  The control means controls the driving of the electric water pump according to the operating state of the engine after the engine is warmed up, and if the electric water pump is driven when the engine is warmed up, The electric water pump may be driven at a higher rotational speed than the above driving.

  According to the engine coolant system of the present invention, it is possible to effectively improve fuel efficiency while promoting warm-up of the engine.

It is a typical whole block diagram which shows the engine cooling water apparatus which concerns on one Embodiment of this invention. It is a figure which shows the relationship between the water flow volume of the cooling water in the engine cooling water apparatus which concerns on one Embodiment of this invention, and the amount of electric heat.

  Hereinafter, an engine cooling water device 1 according to an embodiment of the present invention will be described with reference to FIGS. The same parts are denoted by the same reference numerals, and their names and functions are also the same. Therefore, detailed description thereof will not be repeated.

  As shown in FIG. 1, an engine cooling water device 1 according to an embodiment of the present invention includes an engine 10, a cooling water flow path 13 provided in the engine 10, and a predetermined interval in front of the engine 10. The disposed radiator 14, the inlet pipe 15 that communicates the outlet portion 13 b of the cooling water passage 13 and the inlet portion 14 a of the radiator 14, and the outlet portion 14 b of the radiator 14 and the inlet portion 13 a of the cooling water passage 13 communicate with each other. Outlet piping 16, bypass piping (bypass passage) 17 that bypasses the radiator 14, thermostat 18 that switches the cooling water passage, and oil that exchanges heat between engine cooling water and engine oil (lubricating oil) It has a cooler 19, an electric water pump 20 that pumps and supplies cooling water, and an ECU (electronic control unit) 40.

  In addition, the cooling water flow path 13, the inlet piping 15, and the outlet piping 16 of this embodiment comprise the cooling water circuit of this invention. Moreover, the oil cooler 19 of this embodiment is corresponded to the heat exchange part of this invention. Furthermore, the ECU 40 of this embodiment corresponds to the control means of the present invention.

  The cylinder head 11 and the cylinder block 12 of the engine 10 are provided with a water jacket (not shown). This water jacket is connected to the cooling water flow path 13, and circulates the cooling water that is pressure-fed and supplied by the electric water pump 20. That is, the cooling water that has flowed from the inlet portion 13 a of the cooling water passage 13 is configured to flow to the outlet portion 13 b of the cooling water passage 13 through the water jacket of the cylinder head 11 and the cylinder block 12.

  An inlet pipe 15 is connected to an inlet portion 14 a provided on the upper side of the radiator 14. Further, an outlet pipe 16 is connected to an outlet portion 14 b provided on the lower side portion of the radiator 14. And the radiator 14 cools the cooling water which flows out out of the cooling water flow path 13 and flows in via the inlet piping 15 by heat exchange with outside air. Thereafter, the cooled cooling water is returned to the cooling water flow path 13 via the outlet pipe 16 so that the cooling water is circulated.

  The bypass pipe 17 has one end connected to the inlet pipe 15 and the other end connected to the outlet pipe 16 so as to bypass the radiator 14. A thermostat 18 is interposed at a branch portion between the bypass pipe 17 and the inlet pipe 15.

  The thermostat 18 is an on-off valve that opens when the temperature of the cooling water flowing through the inlet pipe 15 rises to a predetermined temperature and allows the cooling water to flow to the radiator 14. That is, when the temperature of the cooling water is equal to or lower than the predetermined temperature, the thermostat 18 is closed and the cooling water flows into the bypass pipe 17. Then, the cooling water flowing through the bypass pipe 17 is returned to the cooling water flow path 13 via the outlet pipe 16 so that the cooling water is bypassed from the radiator 14 and circulated. As this thermostat 18, for example, a known wax type thermostat is used.

  The oil cooler 19 is interposed in the outlet pipe 16 located on the downstream side of the junction between the outlet pipe 16 and the bypass pipe 17. The oil cooler 19 is connected to a lubricating oil circulation path (not shown) for heat exchange between the cooling water and the engine oil. This engine oil lubricates each sliding part (not shown) in the engine 10, and examples of the sliding part in the engine 10 include a rocker arm, a camshaft, a piston, a piston pin, a crankshaft bearing, and the like. is there.

  The electric water pump 20 is provided in the outlet pipe 16 located between the junction of the outlet pipe 16 and the bypass pipe 17 and the oil cooler 19. The electric water pump 20 is a known centrifugal pump that pumps cooling water by rotation of an impeller (not shown), and includes a drive motor 21 connected to a shaft of the impeller (not shown). The operation of the drive motor 21 is controlled by the ECU 40. That is, the electric water pump 20 is configured to perform the pumping supply (circulation) of the cooling water and stop the pumping supply (stopping the circulation) by controlling the operation of the drive motor 21 by the ECU 40. .

  The ECU 40 performs various controls of the engine 10 and the vehicle on which the engine 10 is mounted, and includes a known CPU, ROM, RAM, input port, output port, and the like. In order to perform these various controls, a rotation sensor, an accelerator sensor, and a drive motor 21 (not shown) are electrically connected to the ECU 40 via electric wiring.

  The ECU 40 also controls the operation of the drive motor 21 (hereinafter also referred to as driving of the electric water pump 20). Specifically, the ECU 40 controls the operation of the drive motor 21 according to the operating state of the engine 10 after the warm-up of the engine 10 is finished. That is, after the warming up of the engine 10 is finished, the electric water pump 20 is driven according to the operating state of the engine 10, and the cooling water is pumped and supplied by the electric water pump 20 according to the operating state of the engine 10.

  On the other hand, when the engine 10 is warming up, the ECU 40 does not output an operation signal to the drive motor 21 until the cooling water boils first. That is, when the engine 10 starts warming up, the electric water pump 20 is stopped until boiling cooling is achieved. When the cooling water boils, the ECU 40 outputs to the drive motor 21 an operation signal having a higher rotational speed than the control according to the operating state of the engine 10 performed after the warm-up ends (control during normal time). In other words, when boiling cooling is performed, the electric water pump 20 is driven such that the pumping supply amount of the cooling water is larger than the pumping supply amount after normal warming (normal pumping supply amount). After that, the ECU 40 is configured to repeatedly control the stopping and driving of the electric water pump 20 until the warming up of the engine 10 is completed.

  With the configuration as described above, the engine cooling water device 1 according to one embodiment of the present invention has the following operational effects.

  At the start of warming up of the engine 10, the electric water pump 20 is first stopped with the thermostat 18 closed. That is, the cooling water stays in the cooling water flow path 13 and the water temperature rapidly rises due to heat transfer from the water jacket in the cylinder head 11 or the cylinder block 12. Then, boiling of the cooling water starts and boiling cooling is performed, so that the heat transfer amount is rapidly increased (see point A in FIG. 2).

  Thereafter, the electric water pump 20 is driven at a higher rotational speed than the rotational speed after completion of warming (normal rotational speed), and high-temperature cooling water (see point B in FIG. 2) with a high heat transfer amount is oil cooler. 19 is pumped and supplied. That is, the oil temperature of the engine oil is effectively raised when the engine 10 is warmed up by heat exchange with the high-temperature cooling water flowing into the oil cooler 19. Further, the stopping and driving of the electric water pump 20 are repeated until the warming up of the engine 10 is completed.

  Therefore, by repeatedly stopping and driving the electric water pump 20 when the engine 10 is warmed up, the warming up of the engine 10 can be promoted, and the oil temperature of the engine oil is raised at an early stage so that each sliding portion By reducing the friction, it is possible to effectively improve the fuel efficiency during warm-up.

  Further, the warming up of the engine 10 is promoted, and the temperature of the combustion chamber (not shown) of the engine 10 rises early, so that HC and CO contained in the exhaust can be reduced, and the exhaust emission is effectively deteriorated. Can be suppressed.

  In addition, this invention is not limited to the above-mentioned embodiment, In the range which does not deviate from the meaning of this invention, it can change suitably and can implement.

  For example, in the above-described embodiment, the pumping supply of the cooling water has been described as being performed by the electric water pump 20, but may be performed by a water pump (not shown) driven by the power of the engine 10 via an electromagnetic clutch. it can.

  In this case, when the engine 10 is warmed up, the electromagnetic clutch is controlled to be disengaged when the water pump is stopped, and the electromagnetic clutch is controlled to be engaged when the water pump is driven.

  Further, the number of revolutions when the electric water pump 20 is driven when the engine 10 is warmed up does not necessarily need to be set higher than the control performed after the warming up (control at the normal time), and is approximately the same as the control after the warming up. You may set to the rotation speed of. Also in this case, since the high-temperature cooling water with a high heat transfer amount flows into the oil cooler 19, the oil temperature of the engine oil can be effectively increased.

10 Engine 13 Engine cooling water flow path (Cooling water circuit)
14 Radiator 15 Inlet piping (cooling water circuit)
16 Outlet piping (cooling water circuit)
17 Bypass piping (bypass flow path)
18 Thermostat (Channel switching means)
19 Oil cooler (heat exchanger)
20 Electric water pump 40 ECU (control means)

Claims (2)

A cooling water circuit for circulating cooling water between the engine and the radiator;
A bypass passage for bypassing the coolant circulating in the coolant circuit from the radiator;
When the temperature of the cooling water circulating through the cooling water circuit is equal to or lower than a predetermined temperature, channel switching means for switching the channel of the cooling water to the bypass channel;
A heat exchanging unit provided in the cooling water circuit for exchanging heat between the lubricating oil of the engine and the cooling water;
An electric water pump that is provided in the cooling water circuit and supplies the cooling water by pressure;
Control means for controlling the drive of the electric water pump,
The engine cooling water device, wherein the control means controls the electric water pump so that the electric water pump repeatedly stops and drives when the engine is warming up. The control means includes
After the engine is warmed up, the driving of the electric water pump is controlled according to the operating state of the engine, and when the electric water pump is driven when the engine is warmed up, the driving after the warming up is higher The engine cooling water device according to claim 1, wherein the electric water pump is driven at a rotational speed.

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