JP2020007971A - Engine cooling device - Google Patents

Abstract

To provide an engine cooling device for enabling the shortening of a warming-up operation time.SOLUTION: The engine cooling device includes a cooling water passage 60 provided in the body of an engine 10 for distributing cooling water to cool the engine body, a cooling water pipe 68 connecting an inflow port 15A and an outflow port 15B of the cooling water passage for circulating the cooling water, a first water pump 50 provided in the cooling water pipe at the inflow port side of the cooling water passage for forcibly feeding the cooling water to the inflow port, a control valve 30 provided in the cooling water pipe at the outflow port side of the cooling water passage so as to be set into a closed state during warming-up operation of the engine and into an opened state after warming-up operation of the engine, a bypass passage 66 for bypassing the control valve in the cooling water pipe at the outflow port side of the cooling water passage, and a second water pump 55 provided in the bypass passage for forcibly feeding the cooling water to the outflow port during warming-up operation of the engine and stopping the forcible feed of the cooling water to the outflow port after finishing the warming-up operation of the engine.SELECTED DRAWING: Figure 1

Description

  The present invention relates to an engine cooling device.

  In an engine cooling device that cools an engine by circulating cooling water, the warm-up time is shortened by stopping the circulation of the cooling water to the engine body when the engine is cold started.

  For example, as shown in FIG. 6, an engine cooling device 101 described in Patent Literature 1 has an outflow water channel provided with a mechanical water pump 150, a communication water channel 166, a flow control valve 130, and a radiator 115. During the warm-up operation, the electronic control unit 140 controls the flow control valve 130 to close to close a part of the outflow water passage 168 formed in an annular shape.

  For this reason, during the warm-up operation, the cooling water discharged from the mechanical water pump 150 circulates around the water pump 150 without flowing to the main body of the engine 110 as shown by an arrow in FIG. The engine warm-up time is reduced.

JP 2017-137775 A

  By the way, in response to the recent tightening of environmental regulations, it is desired to further shorten the warm-up operation time in order to further improve fuel efficiency and achieve early activation of the exhaust gas purifying catalyst at the time of cold start.

  The present invention has been made in view of such a point, and an object of the present invention is to provide an engine cooling device capable of shortening a warm-up operation time.

  In order to solve the above problems, a first invention is provided with a cooling water passage provided in an engine main body and cooling the engine main body by flowing cooling water, and an inlet and an outlet of the cooling water passage. A cooling water pipe that forms a circulation path for connecting and circulating the cooling water, and a cooling water pipe that is provided on the cooling water passage of the cooling water passage near the inflow port and pumps the cooling water toward the inflow port. (1) a water pump, which is provided on the cooling water passage in the cooling water passage on the side of the outflow port, is closed when the engine is warmed up, and is opened after the engine is warmed up A control valve, a bypass passage provided to bypass the control valve on the side of the cooling water passage of the cooling water passage near the outflow port, and a bypass passage provided in the bypass passage, A second water pump for pumping the cooling water toward the outlet during the operation of the engine and stopping the pumping of the cooling water to the outlet after the warm-up operation of the engine is completed. It is.

  Next, a second invention of the present invention is the engine cooling device according to the first invention, wherein the second water pump is driven by rotational power transmitted from an output shaft of the engine via an electromagnetic clutch. When driven, the electromagnetic clutch is controlled to the connected side during the warm-up operation, transmits rotational power from the output shaft of the engine to the second water pump, and is controlled to be released after the warm-up operation is completed. An engine cooling device for stopping transmission of rotational power from an output shaft of the engine to the second water pump.

  According to the first aspect, during the warm-up operation, the cooling water is pumped from the first water pump to the inlet, and the cooling water is pumped from the second water pump to the outlet. As a result, the cooling water can be kept in the engine, the mechanical loss can be increased, and the fuel injection amount can be increased. Therefore, it is possible to further reduce the warm-up operation time, and to further improve the fuel efficiency and activate the catalyst at an early stage.

  According to the second invention, since both the first water pump and the second water pump can be mechanical water pumps, the mechanical loss is further increased as compared with the case where only the first water pump is a mechanical water pump. As a result, it is possible to further improve the exhaust gas temperature rising property of the exhaust gas.

FIG. 2 is a block diagram illustrating an overall configuration of an engine cooling device and control during a warm-up operation. FIG. 4 is a block diagram illustrating control after a warm-up operation of the engine cooling device is completed. It is a figure of a flowchart explaining the processing of warm-up operation control of an engine cooling device. FIG. 4 is a diagram illustrating a relationship between a cooling capacity of an engine cooling device and an engine output of the engine. FIG. 4 is a diagram illustrating a relationship between a water pump drive loss of the engine cooling device and an engine load of the engine. FIG. 7 is a block diagram illustrating the overall configuration of a conventional engine cooling device.

● [Schematic overall configuration of engine cooling device 1 (FIG. 1)]
The overall configuration of the engine cooling device 1 according to the embodiment of the present invention will be described with reference to FIG.

  As shown in FIG. 1, the engine cooling device 1 includes a radiator 15, a control valve 30, a first water pump 50, a second water pump 55, a cooling water passage 60, a radiator water passage 61, and a suction water passage 64. , A bypass passage 66, a cooling water pipe 68, and the control means 40.

  The cooling water passage 60 is a cooling water passage that is provided in the main body of the engine 10 and cools the main body of the engine 10 by flowing the cooling water. The cooling water pipe 68 connects the inflow port 15A and the outflow port 15B of the cooling water passage 60 to form a circulation path for circulating the cooling water.

  The first water pump 50 is provided on the side of the inlet 15A in the cooling water passage 60 of the cooling water pipe 68 to supply the sucked cooling water to the inlet 15A during the warm-up operation of the engine 10 and after the warm-up operation is completed. Pumped towards. The first water pump 50 is a mechanical water pump, is driven by rotational power transmitted from an output shaft of the engine 10, and pumps in the taken-in cooling water.

  The control valve 30 is provided on the side of the outlet 15B in the cooling water passage 60 of the cooling water pipe 68, and is closed when the engine 10 is warmed up, and is opened after the engine 10 is warmed up. .

  The bypass passage 66 is provided on the cooling water passage 60 of the cooling water pipe 68 on the side of the outlet 15B so as to bypass the control valve 30.

  The second water pump 55 is provided in the bypass passage 66 to pump the cooling water toward the outlet 15B during the warm-up operation of the engine 10, and to supply the cooling water to the outlet 15B after the warm-up operation of the engine 10 is completed. Stop pumping.

  The second water pump 55 is a mechanical water pump, has an electromagnetic clutch 55a controlled by the control unit 40, and is driven by rotational power transmitted from the output shaft of the engine 10 via the electromagnetic clutch 55a. You. The electromagnetic clutch 55a is controlled to the connected side during the warm-up operation, transmits the rotational power from the output shaft of the engine 10 to the second water pump 55, and is controlled to the open side after the warm-up operation is completed. The transmission of the rotational power from the output shaft of the engine to the second water pump 55 is stopped.

  The outlet water temperature sensor 25 is provided at the outlet 15B, measures the temperature of the cooling water flowing out of the outlet 15B through the cooling water passage 60 in the engine 10, and outputs a signal corresponding to the measurement to the control means 40. I do. The control means 40 controls the control valve 30 and the electromagnetic clutch 55a based on the temperature of the cooling water measured by the outlet water temperature sensor 25.

● [Description of warm-up operation control process of engine cooling device 1 (FIGS. 1 to 3)]
The control during the warm-up operation of the engine cooling device 1 and after the warm-up operation is completed will be described in detail with reference to FIGS. FIG. 1 is a block diagram illustrating control during a warm-up operation of the engine cooling device 1. FIG. 2 is a block diagram illustrating control after the warm-up operation of the engine cooling device 1 is completed. FIG. 3 is a flowchart illustrating a process of the warm-up operation control of the engine cooling device 1. Note that arrows in the cooling water passage 60 and the cooling water pipe 68 in FIGS. 1 and 2 indicate the direction in which the cooling water flows.

  The processing procedure of the control means 40 of the engine cooling device 1 will be described with reference to the flowchart of FIG. The control unit 40 executes the warm-up operation control process at predetermined time intervals (for example, at intervals of several [ms]) after the engine 10 is started. Hereinafter, each step of the warm-up operation control process will be described in detail.

  In step S010, when the control unit 40 determines that the temperature of the cooling water is lower than the predetermined temperature based on the information from the outlet water temperature sensor 25 (Yes), the control unit 40 proceeds to step S020, and proceeds to step S020. If it is determined that the temperature is not lower than the predetermined temperature (No), the process proceeds to step S040. The predetermined temperature is a preset temperature of the cooling water, and is stored in a storage unit (not shown) of the control unit 40.

  In step S020, control means 40 controls electromagnetic clutch 55a to the connection side, and proceeds to step S030.

  In step S030, the control means 40 controls the control valve 30 to the closed state, and ends the warm-up operation control process.

  In step S040, the control means 40 controls the electromagnetic clutch 55a to the release side, and proceeds to step S050.

  In step S050, the control means 40 controls the control valve 30 to the open state, and ends the warm-up operation control process.

[Control during warm-up operation (Fig. 1)]
Since the control valve 30 is in the closed state, the cooling water pumped by the second water pump 55 flows into the outlet 15B. Further, the first water pump 50 pumps the cooling water toward the inflow port 15A. Therefore, the cooling water is pumped in the cooling water passage 60 in two directions: a direction from the inlet 15 </ b> A into the engine 10 and a direction from the outlet 15 </ b> B into the engine 10. , Stays in the cooling water passage 60 and is not circulated in the cooling water piping 68.

  Since the cooling water remains in the cooling water passage 60 of the engine 10, the exhaust gas temperature rises in a shorter period of time as compared with the case where the cooling water flows through the cooling water passage 60 and circulates in the cooling water pipe 68. The time required for the warm-up operation is reduced. Further, since both the first water pump 50 and the second water pump 55 are driven, the mechanical loss is further increased and the exhaust gas temperature rises as compared with the case where only the first water pump 50 is a mechanical water pump. Performance can be improved.

[Control after completion of warm-up operation (FIG. 2)]
The first water pump 50 pumps the cooling water toward the inlet 15A. Since the electromagnetic clutch 55a is on the open side, the second water pump 55 stops driving and does not pump cooling water. Further, since the control valve 30 is in the open state, the cooling water pumped by the first water pump 50 and flowing toward the inflow port 15A flows through the cooling water passage 60 and flows out from the outflow port 15B. The cooling water flowing out of the outlet 15B is passed through the radiator 15 via the radiator water channel 61 in the cooling water pipe 68. Then, the cooling water that has passed through the radiator 15 is taken into the suction port of the first water pump 50 via the suction water passage 64 in the cooling water piping 68, is circulated through the cooling water passage 60, and flows through the cooling water piping 68. Circulated. Since the cooling water is circulated in the cooling water pipe 68 through the cooling water passage 60, necessary cooling capacity after the warm-up operation is ensured.

[Explanation of Effects of the Present Invention (FIGS. 4 and 5)]
FIG. 4 is a diagram illustrating the relationship between the engine output of the engine and the cooling capacity of the engine cooling device. FIG. 5 is a diagram illustrating the relationship between the engine load of the engine and the water pump drive loss of the engine cooling device. Note that, for simplicity, the engine speed is constant in FIGS. 4 and 5.

  In FIG. 4, a straight line Sa1 shows general characteristics in the cooling capacity of an engine cooling device using a mechanical water pump, a straight line Sa2 shows characteristics in a case where an electric water pump or the like is used, and a straight line Sa3 shows This shows the characteristics when the circulation of the cooling water is stopped during the warm-up operation of the engine when an electric water pump or the like is used. Further, a straight line Sa4 shows the characteristic of the cooling capacity when the engine cooling device of the present invention is used.

  In FIG. 5, a straight line Sb1 shows general characteristics of a water pump drive loss of an engine cooling device using a mechanical water pump, a straight line Sb2 shows characteristics when an electric water pump or the like is used, and a straight line Sb3. Shows the characteristics when the circulation of the cooling water is stopped during the warm-up operation of the engine when an electric water pump or the like is used. Further, a straight line Sb4 indicates a characteristic of a water pump driving loss when the engine cooling device of the present invention is used.

  4, the horizontal axis indicates the engine output, and the vertical axis indicates the cooling capacity of the engine cooling device. Regarding the engine output on the abscissa, the low engine output side is a normal use area, and the high engine output side is a high output area. The cooling capacity on the vertical axis is relatively expressed as high / low.

  In the engine cooling device using the mechanical water pump, the cooling capacity is adjusted so that the cooling capacity can be ensured even when the engine output is in the high output range. Therefore, the cooling capacity is excessive in the normal range (straight line Sa1). ).

  In the case of an electric water pump or a water pump that can mechanically change the flow rate of cooling water, the cooling capacity can be adjusted according to the engine output. Therefore, the cooling capacity can be adjusted to be low in the normal use area and high in the high output area (straight line Sa2). By stopping the electric water pump and the like, the cooling capacity is reduced as much as possible (straight line Sa3).

  The engine cooling device according to the embodiment of the present invention stops the circulation of the cooling water in the cooling water passage during the warm-up operation and keeps the cooling water in the engine. (Straight line Sa4). Thereby, the engine cooling device of the present invention can improve the warm-up property.

  In FIG. 5, the horizontal axis represents the load of the engine, and the vertical axis represents the drive loss of the water pump of the engine cooling device. Regarding the engine output on the abscissa, the low engine output side is a normal use area, and the high engine output side is a high output area. The water pump drive loss on the vertical axis is relatively expressed as large and small.

  In the engine cooling device using the mechanical water pump, the engine pump speed is constant from the normal load range to the high output range, so that the water pump drive loss is constant (straight line Sb1).

  In the case of an electric water pump or a water pump that can mechanically change the flow rate of the cooling water, the discharge flow rate of the water pump can be changed to adjust the cooling capacity according to the engine load, so that the cooling capacity can be adjusted. Therefore, the water pump drive loss can be reduced in the normal use area, and the water pump drive loss can be increased in the high output area (straight line Sb2). Further, by stopping the electric water pump or the like, the water pump driving loss is reduced as much as possible (straight line Sb3).

  In the engine cooling device according to the embodiment of the present invention, since both the first water pump and the second water pump are mechanical water pumps, when the warm-up operation uses one conventional mechanical water pump. As compared with (straight line Sb1), the water pump drive loss in the normal to high output range can be increased (straight line Sb4). During the warm-up operation, the second water pump is disconnected by using the electromagnetic clutch, and thus the water pump drive loss after the warm-up operation is a straight line Sb1. That is, after the warm-up operation is completed, the engine cooling device of the present invention can suppress the drive loss to the same level as in the related art using one mechanical water pump.

As a result, during the warm-up operation, the mechanical loss based on the water pump drive loss increases. Therefore, control is performed to increase the engine output with respect to the mechanical loss, and specifically, the fuel amount to the engine is increased. Due to the increase in the amount of fuel, the amount of heat (heat) input to the engine during the warm-up operation increases, so that the warm-up operation time is shortened. Accordingly, although the amount of fuel during the warm-up operation of the engine increases, the warm-up operation time can be shortened, so that the fuel efficiency is improved as a whole, and the catalyst can be activated early.
● [Effects of the present application]

  As described above, during the warm-up operation, the engine cooling device described in the present embodiment pumps cooling water from the first water pump to the inlet, and sends cooling water from the second water pump to the outlet. To pump. As a result, the cooling water can be kept in the engine, the mechanical loss can be increased, and the fuel injection amount can be increased. Therefore, it is possible to further reduce the warm-up operation time, and to further improve the fuel efficiency and activate the catalyst at an early stage.

  The engine cooling device of the present invention is not limited to the configuration, structure, and the like described in the present embodiment, and various changes, additions, and deletions can be made without changing the gist of the present invention. In particular, the second water pump 55 is not limited to a mechanical water pump, but may be an electric water pump.

Reference Signs List 1 engine cooling device 10 engine 15 radiator 15A inflow port 15B outflow port 25 outflow water temperature sensor 30 control valve 40 control means 50 first water pump 55 second water pump 55a electromagnetic clutch 60 cooling water passage 61 radiator water passage 64 suction water passage 66 bypass Passage 68 Cooling water pipe Sa1 Straight line Sa2 Straight line Sa3 Straight line Sa4 Straight line Sb1 Straight line Sb2 Straight line Sb3 Straight line Sb4 Straight line 101 Engine cooling device 110 Engine 115 Radiator 130 Flow control valve 140 Electronic control unit 150 Water pump 166 Outgoing water channel 168

Claims (2)

A cooling water passage provided in the main body of the engine and cooling the main body of the engine by flowing cooling water;
A cooling water pipe forming a circulation path that connects the inflow port and the outflow port of the cooling water passage and circulates the cooling water,
A first water pump that is provided on the side of the cooling water passage of the cooling water passage near the inflow port and pumps cooling water toward the inflow port;
A control valve that is provided on the cooling water passage in the cooling water passage on the side of the outflow port, is closed when the engine is warmed up, and is opened after the engine has been warmed up,
A bypass passage provided to bypass the control valve, on a side of the cooling water passage in the cooling water passage of the cooling water pipe;
Provided in the bypass passage, for pumping the cooling water toward the outlet during the warm-up operation of the engine, and stopping the pumping of the coolant to the outlet when the warm-up operation of the engine is completed, With two water pumps,
Engine cooling device. The engine cooling device according to claim 1,
The second water pump is driven by rotational power transmitted from an output shaft of the engine via an electromagnetic clutch,
The electromagnetic clutch,
Controlled to the connection side during the warm-up operation, transmitting rotational power from the output shaft of the engine to the second water pump,
After the warming-up operation is completed, the opening side is controlled to the open side to stop transmission of rotational power from the output shaft of the engine to the second water pump,
Engine cooling device.

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