JP2008126798A - Engine cooling system for vehicle - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To reduce the drive power of an engine cooling system for a vehicle driving a cooling fan and a water pump for cooling a radiator by a motor. <P>SOLUTION: The pump motor 6 of the water pump 5 for circulating a cooling liquid is used as the driving source of the cooling fan 4. An electromagnetic clutch 21 is provided between the pump motor 6 and the cooling fan 4, and the clutch 21 is brought into a connected state when a temperature of the cooling liquid discharged from an engine 1 is a prescribed temperature or higher, and it is brought into a shut-off state when the temperature of the cooling liquid is lower than the prescribed temperature. Furthermore, when the temperature of the cooling liquid is lower than the prescribed temperature and a vehicle speed is a prescribed speed or higher, the clutch 21 is brought into the connected state, and the turning force of the cooling fan 4 receiving traveling air is transmitted to the pump motor 6, thereby reducing its load. <P>COPYRIGHT: (C)2008,JPO&INPIT

Description

  The present invention relates to a vehicle engine cooling system configured to cool engine coolant with a radiator, and more particularly, a cooling fan for cooling a radiator is driven by a motor of a water pump for circulating coolant. About.

In a vehicle engine cooling system, coolant that has risen in temperature due to cooling of the engine is sent to a radiator by a water pump, where it is cooled by air from a running wind or a cooling fan, and then returned to the engine again. It is basically based on circulating coolant.
Engine cooling is to prevent overheating. However, excessive cooling increases engine heat loss and mechanical loss due to increased friction in sliding parts such as bearings and piston rings. It is therefore desirable to perform proper cooling with minimal energy.

  According to the conventional example related to engine cooling, in the method of driving the water pump and the cooling fan by the engine (hereinafter referred to as Conventional Example 1), cooling by the radiator is possible by the natural convection of the coolant and the air flow obtained by running the vehicle. In this case, since the cooling fan is driven, there is a first drawback in that power for driving the cooling fan is wasted. Further, during high-speed operation, the water pump also has a second drawback in that unnecessary energy is consumed because the coolant speed becomes higher with the engine speed and more coolant than necessary is circulated.

  As an improved example, as described in Non-Patent Document 1, a cooling fan is driven by a motor, and the operation of the cooling fan is controlled in accordance with the cooling state of the engine (hereinafter, a conventional example). 2) and is generally implemented. According to this method, the first defect can be eliminated, but the second defect remains. Furthermore, a method (hereinafter, Conventional Example 3) is also implemented in which the water pump and the cooling fan are driven by individual motors, and the individual rotational speeds are controlled in accordance with the cooling state of the engine. According to this, the first and second drawbacks can be eliminated.

As another example of the driving method of the cooling fan, in addition to the above method, for example, in Patent Document 1, the cooling fan is driven by a motor directly connected to a warm water water pump that circulates the warm water of a heating regenerator. It is considered to be. Specifically, when the cooling fan is rotated, the impeller of the hot water water pump also rotates, but the impeller is rotated in the reverse direction so that the hot water is not circulated. When circulating the hot water, the motor is rotated in the opposite direction to that described above, and the hot water water pump circulates the hot water, but the cooling fan is not rotated using the power transmission selection means. According to this, it is said that the noise and driving power of the air cooling fan can be reduced because the cooling fan does not rotate during hot water circulation. However, in this configuration, when the temperature of the engine becomes high and the cooling fan is driven, the hot water water pump rotates in the direction opposite to that of the pump operation, so no power is generated to circulate the cooling liquid. In addition to energy loss due to rotation in the interior, there are the same disadvantages as in Conventional Example 2.
JP 2002-97956 A Automotive Technology Handbook 4 Design (Powertrain), Japan Society for Automotive Technology, 2005 p. 65-66)

  As described above, the cooling of the engine is performed by circulating a cooling liquid that has cooled the engine with a water pump and cooling the air with a radiator. The coolant directly cooling the engine needs to be circulated almost always during the operation of the engine. Therefore, the water pump is operated almost all time while the engine is operating. On the other hand, in the radiator, when the vehicle travels, wind is applied to the radiator by the traveling of the vehicle. Hereinafter, this wind is referred to as a traveling wind. Since the wind speed of the traveling wind that passes through the radiator is about 20 to 30% of the vehicle speed, there is a case where the coolant can be sufficiently cooled only by the traveling wind even when the cooling fan is not rotated at the time of middle / high speed traveling. Many. For this reason, the time required to operate the cooling fan is as short as about 10% of the total operating time of the engine, although it depends on the running conditions of the vehicle and the atmospheric temperature.

  As described above, the radiator is sufficiently cooled only by the traveling wind for many periods during traveling of the vehicle. While the vehicle is traveling, the cooling fan also obtains rotational force from the traveling wind. However, in the conventional examples 1, 2, and 3 and Patent Document 1, particularly in the conventional examples 2 and 3 and Patent Document 1, the driving power is reduced because the cooling fan obtains the rotational force by the traveling wind, but the effect is Only when the cooling fan is driven. Considering that the required operating time of the cooling fan is short as described above, the effect of the actual traveling wind is small.

  The present invention has been made in view of the above circumstances, and its purpose is to stop the driving of the cooling fan because the cooling liquid can be sufficiently cooled by the running air in the configuration in which the cooling fan of the radiator and the water pump are motor-driven. Even in such a case, to provide a vehicle engine cooling system that can reduce the power required for cooling by assisting the power of the water pump by using the rotational force of the cooling fan obtained by the traveling wind to drive the water pump. is there.

(Prerequisite configuration of the present invention)
The vehicle engine cooling system includes a water pump for circulating engine coolant, a radiator for cooling the coolant, and a cooling fan for cooling the radiator.
In the present invention, it is assumed that the drive source of the water pump is a motor (pump motor), and the cooling fan is rotationally driven using the rotation of the pump motor. Then, a clutch for intermittently connecting the cooling fan to the pump motor is provided, and this clutch is intermittently controlled by the control means.

(First means of the present invention)
In order to achieve the above object, the first means of the present invention (Claim 1) is provided with temperature detecting means for detecting the temperature of the cooling liquid, and the cooling liquid is cooled by the radiator according to the detected temperature of the temperature detecting means. In this case, it is possible to determine whether or not it is necessary to forcibly cool the radiator by rotating the cooling fan.

  Furthermore, in the present invention, when the cooling fan is rotated by receiving external wind pressure (including traveling wind pressure), an assist capability detecting means is provided for detecting whether or not the cooling fan has an assist capability for the pump motor. . Here, the assist capability means that when the cooling fan is forcibly rotated under the external wind pressure, the rotation speed of the cooling fan exceeds the speed when the cooling fan is rotated by the pump motor. By transmitting it to the pump motor, the cooling fan can reduce the load on the pump motor. In this way, it means the ability of the cooling fan to transmit the rotational force to the pump motor.

  The control means engages the clutch when the detected temperature of the temperature detecting means is equal to or higher than the predetermined temperature, or when the detected temperature of the temperature detecting means is less than the predetermined temperature and the assist capability detecting means detects that the assist capability is present. The pump motor and the cooling fan are connected, and when the detected temperature of the temperature detecting means is less than a predetermined temperature and the assist capability detecting means detects no assist capability, the clutch is disengaged to connect the pump motor and the cooling fan. Cut off.

  As described above, according to the first means, when the radiator needs to be cooled by the cooling fan (when the temperature detected by the temperature detecting means is equal to or higher than the predetermined temperature), the clutch is engaged and the cooling fan is operated by the pump motor. It is driven to rotate. When the radiator is not required to be cooled by the cooling fan, the clutch is disconnected as a general rule so that the pump motor does not drive the cooling fan, so that the pump motor is not operated wastefully.

  Moreover, even if it is no longer necessary to cool the radiator with the cooling fan, if the cooling fan has the assist capability, the clutch is in the connected state, so the rotation of the cooling fan that is forced to rotate by the external wind pressure is pumped. The load on the pump motor can be reduced by transmitting to the motor. Of course, when the radiator needs to be cooled by the cooling fan, the clutch is in the connected state. If the cooling fan is in an assisting state at this time, the pump is driven by the cooling fan that is forcibly rotated by the external wind pressure. The motor can be driven and the load can be reduced.

  In the first means, the assist capability detecting means determines that the assist capability is present when the vehicle speed sensor for detecting the speed of the vehicle and the detection speed of the vehicle speed sensor is equal to or higher than the predetermined speed, and the detection speed of the vehicle speed sensor is the predetermined speed. If it is less than the value, it can be constituted by a determination means for determining that there is no assist capability (claim 2).

  The assist capability detection means calculates motor rotation speed detection means for detecting the rotation speed of the pump motor, a vehicle speed sensor for detecting the speed of the vehicle, and calculates the detection speed of the vehicle speed sensor as the rotation speed of the cooling fan. When the rotation speed exceeds the rotation speed of the pump motor detected by the motor rotation speed detection means, it is determined that the assist capability is present. When the rotation speed of the cooling fan is equal to or less than the rotation speed of the pump motor, it is determined that there is no assist capability. It may be constituted by a determination means (claim 3).

  Further, the assist capability detection means includes a fan rotation speed detection means for detecting the rotation speed of the cooling fan, a motor rotation speed detection means for detecting the rotation speed of the pump motor, a vehicle speed sensor for detecting the speed of the vehicle, and a fan rotation. When the rotation speed of the cooling fan detected by the number detection means exceeds the rotation speed of the pump motor detected by the motor rotation speed detection means, it is determined that there is an assist capability, and when the vehicle speed sensor detects a predetermined speed or less, It can also be configured by a determination means for determining that there is no assist capability (claim 4).

(Second means of the present invention)
In order to achieve the above object, in the second means of the present invention (Claim 5), when the radiator needs to be cooled by a cooling fan (when the temperature detected by the temperature detecting means is equal to or higher than a predetermined temperature), the clutch is When the cooling fan is rotated by the pump motor in the connected state and the radiator need not be cooled by the cooling fan, the clutch is disconnected and the cooling fan is not rotated by the pump motor. A one-way clutch is provided between the pump motor and the cooling fan. When the cooling fan tries to rotate faster than the pump motor under the external wind pressure regardless of the intermittent state of the clutch (with assist capability), The rotation of the cooling fan is transmitted to the pump motor by the direction clutch.

  According to this second means, when it is not necessary to cool the radiator by the cooling fan, the clutch is disengaged so that the cooling fan is not driven to rotate by the pump motor, and by the action of the one-way clutch. When the cooling fan is rotated by the external wind pressure and has an assist capability, the rotation of the cooling fan is automatically transmitted to the pump motor to reduce the load on the pump motor.

(Additional configuration to the first and second means)
In the present invention, the following configuration can be added to the above-described first means and second means.

  The number of rotations of the pump motor may be varied depending on the detected temperature of the temperature detecting means (Claim 6), and the temperature of the coolant at the inlet side and the temperature at the outlet side of the engine The height may be changed according to the magnitude of the difference (claim 7). When the rotational speed of the pump motor is changed in this way, the rotational speed of the cooling fan can be increased when the coolant needs to be cooled more strongly by the radiator.

  Further, rotation transmission from the pump motor to the water pump can be performed by magnetic coupling (claim 8). According to this configuration, since the pump motor and the water pump can be shielded without using a mechanical seal, leakage of the coolant in the power transmission portion from the pump motor to the water pump is eliminated, and friction loss due to the seal is reduced. Can be reduced.

  The energization of the pump motor may be delayed from the engine start. In this way, since the pump motor is energized while avoiding the engine start when a large current flows through the starter motor, the load on the vehicle battery can be reduced.

  In addition to the cooling fan, a radiator or a cooling fan for cooling an object to be cooled other than the radiator is provided, and a motor for driving the other cooling fan is provided when the driving of the other cooling fan is not required. When receiving a rotational force from another cooling fan, the motor generator may function as a generator. In this way, when the other cooling fan is rotated by the external wind pressure, the motor generator can generate power to charge the vehicle battery.

(First embodiment)
A first embodiment of the present invention will be described below with reference to FIGS. FIG. 2 schematically shows a configuration of a cooling system of an engine as a vehicle propulsion source, for example, a gasoline engine. As shown in FIG. 2, a jacket 2 is formed in the engine 1, and cooling of the engine 1 is performed by passing a coolant through the jacket 2. The engine cooling system is a system for cooling the engine 1 by circulating the coolant whose temperature has been increased by cooling the engine 1 so that it is cooled outside and returned to the engine 1 again. A fan 4, a water pump 5, and a pump motor 6 that drives the water pump 5 are provided.

  The pump motor 6 is fixed to a support frame 7 attached to the rear part of the radiator 3. The pump motor 6 is composed of, for example, a brushless DC motor, and as shown in FIG. 1, a stator 9 fixed to a motor case 8 and a rotor 11 rotatably supported by the motor case 8 via a bearing 10. And. Then, both end portions of the rotating shaft 12 of the rotor 11 protrude from the motor case 8 to both the front and rear sides. The stator 9 is formed by winding a multi-phase coil 9b around a stator core 9a. The rotor 11 is of a permanent magnet type in which a permanent magnet 11b magnetized with a plurality of poles is attached to the outer periphery of the rotor core 11a.

  The water pump 5 is attached to the rear part of the pump motor 6. The water pump 5 is configured as a centrifugal type, and the impeller 14 in the casing 13 is fixed to the rear end portion of the rotary shaft 12 of the pump motor 6. The water pump 5 and the pump motor 6 are sealed by a mechanical seal 15 so that the coolant does not leak to the pump motor 6 side. The mechanical seal 15 is a seal that is provided on the side of the partition plate 17 that partitions the floating seat 16 provided on the impeller 14 and the water pump 5 and the pump motor 6 and is pressed against the floating seat 16 by a bellows spring 18. The floating sheet 16 is configured to slide relative to the seal ring 19.

  On the other hand, the cooling fan 4 is rotatably supported via a bearing 20 at the front end portion of the rotary shaft 12 of the pump motor 6. A clutch such as an electromagnetic clutch 21 is provided between the cooling fan 4 and the pump motor 6. The electromagnetic clutch 21 includes a clutch plate 22 fixed to the rotating shaft 12, a clutch plate 24 made of a magnetic material such as iron attached so as to be movable in the axial direction by a pin 23 protruding from the cooling fan 4 side, And an electromagnetic coil 25 fixed to the motor case 8 of the pump motor 6.

  When the electromagnetic coil 25 is energized, the magnetic force thereof causes the clutch plate 24 of the cooling fan 4 to be attracted to the clutch plate 22 of the rotary shaft 12 to be connected, and the rotary shaft 12 of the pump motor 6 and the cooling fan 4 are connected. Connected. Then, when the electromagnetic coil 25 is disconnected, the suction of the cooling fan 4 to the clutch plate 22 of the clutch plate 24 is released, and the connection between the rotary shaft 12 of the pump motor 6 and the cooling fan 4 is released. .

  Now, the water pump 5 is for circulating the coolant, and as shown in FIG. 3, its inlet 5a is connected to the outlet 2a of the jacket 2 of the engine 1 by a hose 26, and the outlet 5b is The thermo valve 27 is connected to the inlet 27 a via a hose 28. The thermo-valve 27 has two outlets 27b and 27c. While the temperature of the coolant is low, the outlet 27c is opened and the outlet 27b is throttled. When the temperature of the coolant rises, the outlet 27b is opened and the outlet 27c is throttled. One outlet 27 b of the thermo valve 27 is connected to the inlet 3 a of the radiator 3 via a hose 29, and the other outlet 27 c is connected to the inlet 2 b of the jacket 2 of the engine 1 via a hose 30. Further, the outlet 3 b of the radiator 3 is also connected to the inlet 2 b of the jacket 2 of the engine 1 via the hose 31.

  FIG. 4 is a block diagram showing a control configuration of the cooling system. The control of the cooling system is performed by a control circuit 32 as a control means mainly composed of a microcomputer (not shown), for example, and the control circuit 32 includes an electromagnetic coil 25 of the electromagnetic clutch 21. In addition, a liquid temperature sensor 33, a vehicle speed sensor 34, an inverter drive device 35, and the like are connected as a coolant temperature detection means.

  The liquid temperature sensor 33 detects the temperature of the coolant at, for example, the outlet 2 a of the jacket 2. The vehicle speed sensor 34 is for detecting the speed of the vehicle. For example, the vehicle speed sensor 34 detects the rotational speed of the axle and inputs the detection output to the control circuit 32. The control circuit 32 is configured to calculate the vehicle speed based on the rotation speed detected by the vehicle speed sensor 34 and the tire diameter stored in advance in a memory (not shown).

  The inverter drive device 35 is for driving the pump motor 6 with an inverter, and a vehicle battery 36 is used as the DC power source. The rotational speed control of the pump motor 6 is performed by a pulse width modulation (PWM) method. For this purpose, the pump motor 6 is provided with, for example, a frequency generator 37 as a rotation speed detection means for detecting the rotation speed, and the detection output is input to the control circuit 32. Then, the control circuit 32 compares the rotational speed of the pump motor 6 detected by the frequency generator 37 with a preset rotational speed, and gives a drive signal corresponding to the speed deviation to the inverter drive device 35. Then, the inverter drive device 35 forms a PWM signal corresponding to the speed deviation given from the control circuit 32 and controls the pump motor 6 so as to become the set rotational speed. The set rotational speed is stored in a memory (not shown) included in the control circuit 32.

  Next, the operation of the above configuration will be described. First, in this embodiment, whether or not the cooling liquid needs to be forcibly cooled is determined based on the temperature detected by the liquid temperature sensor 33. That is, when the liquid temperature sensor 33 detects a predetermined temperature or higher, it is determined that forced cooling is necessary. When forced cooling is necessary, the cooling fan 4 is connected to the rotary shaft 12 of the pump motor 6, and the cooling fan 4 is rotationally driven by the pump motor 6.

  When the speed of the vehicle is equal to or higher than a predetermined speed, the cooling fan 4 receives the traveling wind pressure (external wind pressure) and tries to rotate faster than the rotational speed of the pump motor 6. It is determined that the load on the pump motor 6 can be reduced by transmission (with an assist capability), and the cooling fan 4 is connected to the rotary shaft 12 of the pump motor 6. Note that the vehicle speed at which it is determined that the assist capability is present is determined in advance as a vehicle speed obtained through experiments and stored in a memory included in the control circuit 32. In the present embodiment, the vehicle speed is obtained by experiments in consideration of the correlation with the rotational speed of the cooling fan.

  The cooling of the coolant will be described below. First, the engine 1 is started by starting an ignition switch (not shown). Then, the control circuit 32 starts the pump motor 6 at the same timing as the start of the engine 1 and circulates the coolant of the engine 1. At the beginning of the engine 1, since the engine 1 is not yet sufficiently warm, the thermo valve 27 closes the outlet 27 b. Accordingly, the coolant circulates from the outlet 2 a of the jacket 2 through the hose 26, the water pump 5, the hose 28, the thermo valve 27, and the hose 30 and returns to the inlet 2 b of the jacket 2, and is sent to the radiator 3. I can't.

  When the engine 1 is warmed and the temperature of the coolant rises, the thermo valve 27 throttles the outlet 27c and opens the outlet 27b, so that the coolant circulates through the jacket 2 and the radiator 3. That is, the coolant in the jacket 2 circulates from the outlet 2a of the jacket 2 to the jacket 2 through the hose 26, the water pump 5, the thermo valve 27, the hose 29, the radiator 3, and the hose 31 in this order. The coolant that has cooled the engine 1 to a high temperature is cooled when passing through the radiator 3.

  On the other hand, when the engine 1 is started, the control circuit 32 starts to execute the electromagnetic clutch control routine of FIG. That is, when entering the electromagnetic clutch control routine of FIG. 5, the control circuit 32 first sets the electromagnetic clutch 21 in the disconnected state as an initial setting (step S1). Next, the control circuit 32 acquires the temperature detected by the liquid temperature sensor 33 (step S2), and determines whether or not the temperature is equal to or higher than a predetermined temperature T (° C.) (step S3). When the engine 1 is about to start, the temperature of the coolant has not increased so much and the temperature detected by the fluid temperature sensor 33 is less than T. Therefore, the control circuit 32 performs forced cooling by the cooling fan 4. It is determined that it is not necessary (“NO” in step S3).

  If it is determined that forced cooling is not necessary, the control circuit 32 acquires the detection speed of the vehicle speed sensor 34 in order to connect and disconnect the electromagnetic clutch 21 according to the presence or absence of the assisting capability of the cooling fan 4 (step S4). Is determined to be equal to or higher than a predetermined speed V (km / s) (step S5: assist ability detecting means, determining means). By the way, when the vehicle speed starts traveling, when the electromagnetic clutch 21 is in the disconnected state, the cooling fan 4 receives the traveling wind pressure and rotates. In this case, when the speed of the vehicle is less than the predetermined speed V, even if the cooling fan 4 is rotated by receiving the traveling wind pressure, the rotation speed of the pump motor 6 is not exceeded, so the control circuit 32 determines that there is no assist capability. ("NO" in step S5), the electromagnetic clutch 21 remains in the disconnected state (step S6).

  When the speed of the vehicle becomes equal to or higher than the predetermined speed V, the cooling fan 4 that rotates by receiving the traveling wind pressure rotates at a rotational speed equal to or higher than the rotational speed of the pump motor 6. Then, the control circuit 32 determines that the cooling fan 4 that rotates by receiving the traveling wind pressure has an assist capability (“YES” in step S5), and energizes the electromagnetic coil 25 to bring the electromagnetic clutch 21 into a connected state (step S5). S7). When the electromagnetic clutch 21 is in the connected state, the rotation of the cooling fan 4 is transmitted to the rotary shaft 12 of the pump motor 6 via the clutch plates 24 and 22 of the electromagnetic clutch 21. For this reason, the load of the pump motor 6 driving the water pump 5 is reduced by the rotational force received from the cooling fan 4 (motor assist).

  After a while from the start of the engine 1, the temperature of the coolant rises. When the temperature of the coolant at the outlet 2a of the jacket 2 becomes equal to or higher than the predetermined temperature T, the control circuit 32 determines that the radiator 3 needs to be forcibly cooled ("YES" in step S3), and the electromagnetic coil 25 Energization is performed to bring the electromagnetic clutch 21 into a connected state (step S8). Thereby, the rotation of the pump motor 6 is transmitted to the cooling fan 4 via the clutch plates 22 and 24, and the cooling fan 4 is rotationally driven.

  When the temperature of the coolant at the outlet 2a of the jacket 2 is equal to or higher than the predetermined temperature T, the electromagnetic clutch 21 remains in the connected state regardless of whether or not the vehicle speed is equal to or higher than the predetermined speed V. . Therefore, when the speed of the vehicle is equal to or higher than the predetermined speed V, the cooling fan 4 has an assist capability. However, since the electromagnetic clutch 21 is in the connected state, the rotation of the cooling fan 4 due to the traveling wind pressure is automatically transferred to the pump motor 6. It is transmitted to reduce the load.

  By the way, for example, when running at medium to high speed, the radiator 3 is cooled by the running wind. Therefore, in the normal case, the coolant at the outlet 2a of the jacket 2 is not required to rotate the cooling fan 4 by the pump motor 6. Is less than a predetermined temperature T. If it becomes like this, the control circuit 32 will carry out intermittent control of the electromagnetic clutch 21 according to the presence or absence of the assist capability of the cooling fan 4 similarly to having mentioned above.

  That is, when the detected temperature of the liquid temperature sensor 33 becomes lower than the predetermined temperature T (“NO” in step S3), the control circuit 32 determines whether or not the detected speed of the vehicle speed sensor 34 is equal to or higher than the predetermined speed V ( Step S4, 5). When the vehicle speed is V or higher, the control circuit 32 determines that the cooling fan 4 has the assist capability (“YES” in step S5), energizes the electromagnetic coil 25 and keeps the electromagnetic clutch 21 in the connected state. And Thereby, the rotation of the cooling fan 4 is transmitted to the pump motor 6 to reduce the load on the pump motor 6 driving the water pump 5. When the speed of the vehicle is less than V, the control circuit 32 puts the electromagnetic clutch 21 into the disconnected state (step S6) so that the pump motor 6 does not drive the cooling fan 4 unnecessarily.

When the vehicle is stopped and the ignition switch is turned off, the engine 1 is stopped, and accordingly, the pump motor 6 is also disconnected and the water pump 5 is stopped. Then, the control circuit 32 also stops the execution of the electromagnetic clutch control routine of FIG.
As described above, according to this embodiment, the drive source of the cooling fan 4 is the pump motor 6 and both are intermittently connected by the electromagnetic clutch 21, so that it is not necessary to forcibly cool the radiator 3 by the cooling fan 4. Until then, the cooling fan 4 is not driven by the pump motor 6.

  Moreover, when it is necessary to forcibly cool the radiator 3 with the cooling fan 4, if the cooling fan 4 that receives the traveling wind pressure has an assist capability, the pump motor 6 is connected via the electromagnetic clutch 21 in which the rotation of the cooling fan 4 is in the connected state. Therefore, the load on the pump motor 6 is reduced. In addition, even if it is not necessary to forcibly cool the radiator 3 with the cooling fan 4, if the cooling fan 4 that receives the traveling wind pressure has assist capability, the electromagnetic clutch 21 is switched from the disconnected state to the connected state to rotate the cooling fan 4. Is transmitted to the pump motor 6, the load on the pump motor 6 can be reduced as described above.

  Therefore, when it is necessary to forcibly cool the radiator 3, if the electromagnetic clutch 21 is in the connected state and the radiator 3 does not have to be forcibly cooled, the electromagnetic clutch 21 is in a disengaged state. Even when the radiator 3 is cooled by the traveling wind and forced cooling by the cooling fan 4 is not required during medium and high speed traveling of the vehicle, if the cooling fan 4 has assist capability, the electromagnetic clutch 21 is connected to the cooling fan. The rotation of 4 can be transmitted to the pump motor 6 to reduce the load on the pump motor 6, and the fuel consumption of the engine 1 can be increased accordingly.

(Second Embodiment)
6 and 7 show a second embodiment of the present invention. This second embodiment is different from the first embodiment described above in that the presence or absence of the assisting capability of the cooling fan 4 is determined by comparing the rotational speed of the cooling fan 4 and the rotational speed of the pump motor 6. is there.
That is, in this embodiment, as shown in FIG. 6, there is no vehicle speed sensor 34, and instead, a rotational speed sensor 38 as a fan rotational speed detection means for detecting the rotational speed of the cooling fan 4 is provided. Yes. Although not shown, the rotational speed sensor 38 is, for example, a permanent magnet provided in the cooling fan 4 and a magnetic detection element such as a Hall element provided in the support frame 7 for detecting the magnetism of the permanent magnet. The magnetic detection element outputs a number of pulses corresponding to the number of rotations of the cooling fan 4. The control circuit 32 calculates the rotational speed of the cooling fan 4 based on the pulse number input from the rotational speed sensor 38.

  In the electromagnetic clutch control routine shown in FIG. 7, the control circuit 32 forcibly cools the radiator 3 by the cooling fan 4 when the temperature at the outlet 2 a of the coolant jacket 2 is lower than the predetermined temperature T (“NO” in step A <b> 3). When there is no need, the rotation speed detected by the rotation speed sensor 38 is acquired (step A4). And the control circuit 32 acquires the rotation speed of the pump motor 6 from the frequency generator 37 as a motor rotation speed detection means, and when the rotation speed of the cooling fan 4 is below the rotation speed of the pump motor 6, there is no assist capability. Judgment is made ("NO" in step A5: judgment means), the electromagnetic clutch 21 is disengaged (step A6), and when the number of revolutions of the cooling fan 4 exceeds the number of revolutions of the pump motor 6, it is judged that the assist capability is present. ("YES" in step A5: determination means) The electromagnetic clutch 21 is brought into a connected state (step A7).

  When the rotation speed of the pump motor 6 is controlled to be a preset rotation speed as in the present embodiment, the setting rotation speed stored in a memory (not shown) of the control circuit 32 is acquired. (Motor rotational speed detection means) may be configured so that the rotational speed of the rotational speed sensor 38 is not acquired. Further, when the rotation of the pump motor 6 is transmitted to the cooling fan 4 via the speed reduction mechanism, the output speed of the speed reduction mechanism becomes the speed of the pump motor 6.

(Third embodiment)
FIG. 8 shows a third embodiment of the present invention. This embodiment is different from the second embodiment described above in that the presence or absence of the cooling fan 4 has an assist capability, the number of rotations of the cooling fan 4 by the traveling wind is calculated from the traveling speed of the vehicle, and the calculated cooling fan 4 and the number of rotations of the pump motor 6 are compared. Therefore, in this embodiment, the rotation speed sensor 38 in the second embodiment is not provided, but the vehicle speed sensor 34 in the first embodiment is provided instead.
That is, when determining whether or not the cooling fan 4 has the assist capability, the control circuit 32 acquires the detection speed of the vehicle speed sensor 34 (step a4 in FIG. 8), and the running wind of the cooling fan 4 is determined from this detection speed. Is calculated (step a5). Note that the detection speed (vehicle speed) of the vehicle speed sensor 34 and the rotation speed of the cooling fan 4 are obtained in advance by experiments and stored in the storage means, and when the detection speed of the vehicle sensor 34 is acquired, cooling is performed from the storage means. You may make it carry out by searching the rotation speed of the fan 4. FIG. Further, the rotation speed of the cooling fan 4 may be calculated by substituting the detection speed of the vehicle speed sensor 34 into a predetermined calculation formula.

  After calculating the rotational speed of the cooling fan 4, the control circuit 32 compares the calculated rotational speed of the cooling fan 4 with the rotational speed of the pump motor 6, and the rotational speed of the cooling fan 4 is obtained from the frequency generator 37. When the rotational speed of the pump motor 6 is less than or equal to the rotational speed of the pump motor 6, it is determined that there is no assist capability ("NO" in step a6: determination means), the electromagnetic clutch 21 is disconnected (step a7), and the rotational speed of the cooling fan 4 is the pump motor. If the rotational speed exceeds 6, the assist capability is determined to be present ("YES" in step a6: determination means), and the electromagnetic clutch 21 is brought into a connected state (step a8).

(Fourth embodiment)
9 to 11 show a fourth embodiment of the present invention. This embodiment differs from the first embodiment described above in that the cooling fan 4 is attached to the rotary shaft 12 of the pump motor 6 via a one-way clutch 39 as shown in FIG. As the one-way clutch 39, for example, a one-way ball clutch or a one-way roller clutch can be considered. In this embodiment, the electromagnetic clutch 21 is a main clutch and the one-way clutch is an auxiliary clutch. Moreover, as a control structure, as shown in FIG. 10, the vehicle speed sensor 34 is not provided.

  In the electromagnetic clutch control routine shown in FIG. 11, the control circuit 32 performs only control for intermittently connecting the electromagnetic clutch 21 in accordance with the temperature of the coolant at the outlet 2 a of the jacket 2. That is, when the temperature detected by the liquid temperature sensor 33 is lower than the predetermined temperature T (“NO” in step B3), the control circuit 32 disengages the electromagnetic clutch 21 (step B4), and the temperature detected by the liquid temperature sensor 33 is When the temperature is equal to or higher than the predetermined temperature T ("YES" in step B3), the electromagnetic clutch 21 is brought into a connected state (step B4).

  The operation of transmitting or not transmitting the rotation of the cooling fan 4 to the pump motor 6 according to the presence or absence of the assisting capability of the cooling fan 4 is automatically performed according to the rotation speed of the cooling fan by the action of the one-way clutch 39. Done. The one-way clutch 39 has a function of transmitting only the rotation of the cooling fan 4 in one direction relative to the rotation shaft 12 of the pump motor 6 to the rotation shaft 12. With this function, when the electromagnetic clutch 21 is in the disconnected state, the one-way clutch 39 is cooled by the rotational speed of the cooling fan 4 that rotates by receiving the traveling wind pressure exceeding the rotational speed of the rotary shaft 12 of the pump motor 6. When the fan 4 rotates in one direction relative to the rotation shaft 12, the rotation of the cooling fan 4 is automatically transmitted to the rotation shaft 12 to assist the pump motor 6.

(Fifth embodiment)
FIG. 12 shows a fifth embodiment of the present invention. This embodiment differs from the first embodiment described above in that rotation transmission from the rotary shaft 12 of the pump motor 6 to the impeller 14 of the water pump 5 is performed by magnetic coupling.
That is, as shown in FIG. 12, the rotating shaft 12 of the pump motor 6 is shortened so as not to protrude toward the water pump 5 side. Further, a cylindrical wall 17a is formed on the center side of the partition plate 17 between the water pump 5 and the pump motor 6, and a boss portion 17b is formed inside the cylindrical wall 17a. A support shaft 40 is fitted into the boss portion 17 b of the partition plate 17, and the impeller 14 is rotatably supported by the support shaft 40 via a bearing 41.

  On the other hand, the magnetic coupling 43 that transmits the rotation of the rotating shaft 12 to the impeller 14 is composed of two permanent magnet rings 44 and 45 having different large and small diameters. These permanent magnet rings 44 and 45 are magnetized so that N poles and S poles are alternately arranged along the circumferential direction, and the permanent magnet ring 44 on the large diameter side is a rotor of the pump motor 6. The permanent magnet ring 45 on the small diameter side is attached to the outside of the cylindrical portion 47 provided on the impeller 14. The permanent magnet ring 45 is attached to the inside of the cylindrical portion 46 provided on the rotor core 11 a. These permanent magnet rings 44 and 45 face each other through the cylindrical wall 17a of the partition plate 17 and exert a magnetic force on each other. The rotation of the rotor 11 is transmitted to the impeller 14 by the magnetic attractive force between the permanent magnet rings 44 and 45.

  According to the present embodiment configured as described above, the space between the water pump 5 and the pump motor 6 can be completely sealed by the partition plate 17 and the support shaft 40. Therefore, the leakage of the coolant can be reliably eliminated. Moreover, the friction loss by a seal | sticker can be reduced compared with 1st Embodiment using the mechanical seal 15 with a sliding part.

(Sixth embodiment)
FIG. 13 shows a sixth embodiment of the present invention. The difference from the first embodiment is that an auxiliary cooling fan 48 is provided separately from the cooling fan 4 to cool the radiator 3. It is in. The auxiliary cooling fan 48 is also driven by a motor, and a motor generator 49 is used as the motor. The motor generator 49 is composed of a permanent magnet type DC motor, and functions as both a motor and a generator.

  The motor generator 49 is attached to the radiator 3 via the support arm 50. When it is necessary to forcibly cool the radiator 3, the motor generator 49 is energized and functions as a motor to rotate the auxiliary cooling fan 48. When it is not necessary to drive the auxiliary cooling fan 48, the motor generator 49 functions as a generator by turning off the motor and rotating the auxiliary cooling fan 48 by the running wind. At this time, the electric power generated by the motor generator 49 is configured to charge the battery 36. Whether or not the auxiliary cooling fan 48 has assist capability is preferably determined based on the vehicle speed, but is not limited thereto.

(Other embodiments)
The present invention is not limited to the embodiment described above and shown in the drawings, and can be expanded or changed as follows.
You may make it change the rotation speed of the pump motor 6 according to the temperature detected by the liquid temperature sensor 33. In this way, the higher the coolant temperature is, the more coolant is circulated, and the cooling fan 4 is also rotated at a high speed, so that the coolant is cooled well.
A liquid temperature sensor for detecting the temperature of the coolant is provided at the outlet 2a and the inlet 2b of the jacket 2 of the engine 1, and the rotational speed of the pump motor 6 is changed in accordance with the detected temperature difference between the two liquid temperature sensors. Also good. In this way, the circulating amount of the coolant can be changed according to the required cooling strength, and the cooling fan 4 is rotated at a speed according to the cooling strength, and the wind speed according to the required cooling strength is increased. The radiator 3 can be cooled by the cooling air.

The position where the liquid temperature sensor 33 is provided is not limited to the outlet 2a and the inlet 2b of the jacket 2, and the radiator 3 and the cir may be provided on the valve 27 or the like. Further, the liquid temperature sensor 33 may be provided so as to be in contact with the cooling liquid and directly detect the temperature of the cooling liquid, or may be detected via the wall of the flow path of the cooling liquid. good.
The activation of the pump motor 6 may be delayed for a predetermined short time from the start of the engine 1. In this way, when the engine 1 is started, a large amount of electric power is required for starting the starter motor, so that the electric power for starting the pump motor 6 is not superimposed on this.
The pump motor 6 is not limited to an electric motor, and may be a motor of another mechanism such as a hydraulic motor.
In the sixth embodiment of FIG. 13, the auxiliary cooling fan 48 may cool an object to be cooled different from the radiator 3, for example, a condenser of an air conditioner.

1 shows a first embodiment of the present invention, and is a longitudinal sectional view of an essential part. Side view showing the entire cooling system Cooling system piping configuration diagram Block diagram showing control configuration Flow chart for electromagnetic clutch control FIG. 4 equivalent view showing the second embodiment of the present invention Figure equivalent to FIG. FIG. 5 equivalent view showing the third embodiment of the present invention FIG. 1 equivalent view showing a fourth embodiment of the present invention 4 equivalent diagram Figure equivalent to FIG. FIG. 1 equivalent view showing a fifth embodiment of the present invention FIG. 2 equivalent view showing a sixth embodiment of the present invention

Explanation of symbols

  In the drawings, 1 is an engine, 2 is a jacket, 3 is a radiator, 4 is a cooling fan, 5 is a water pump, 6 is a pump motor, 12 is a rotating shaft, 14 is an impeller, 21 is an electromagnetic clutch, 25 is an electromagnetic coil, 27 Is a thermo valve, 32 is a control circuit (control means, assist capability detection means, determination means), 33 is a liquid temperature sensor (temperature detection means), 34 is a vehicle speed sensor, 37 is a frequency generator (motor rotation speed detection means), Reference numeral 38 denotes a rotation speed sensor (fan rotation speed detection means), 29 a one-way clutch, 43 a magnetic coupling, 48 an auxiliary cooling fan, and 49 a motor generator.

Claims (10)

A water pump for circulating engine coolant, which is the propulsion source of the vehicle,
A pump motor for driving the water pump;
Temperature detecting means for detecting the temperature of the coolant;
A radiator for cooling the coolant circulated by the water pump;
A cooling fan for cooling the radiator;
A clutch for intermittently connecting the cooling fan to the pump motor;
An assist capability detection means for detecting whether or not there is an assist capability to apply a rotational force from the cooling fan to the pump motor when the cooling fan rotates by receiving external wind pressure;
Control means for controlling the clutch,
When the detected temperature of the temperature detecting means is equal to or higher than a predetermined temperature, and when the detected temperature of the temperature detecting means is less than a predetermined temperature and the assist capability detecting means detects that the assist capability exists, the control means When the detected temperature of the temperature detecting means is lower than a predetermined temperature and the assist capability detecting means detects that the assist capability is absent, the clutch is disconnected. The vehicle engine cooling system is characterized in that the pump motor and the cooling fan are shut off. The assist ability detecting means includes
A vehicle speed sensor for detecting the speed of the vehicle;
And determining means for determining that the assist capability is present when the detection speed of the vehicle speed sensor is equal to or greater than a predetermined speed, and determining that the assist capability is absent when the detection speed of the vehicle speed sensor is less than the predetermined speed. The vehicle engine cooling system according to claim 1. The assist ability detecting means includes
Motor rotation number detecting means for detecting the rotation number of the pump motor;
A vehicle speed sensor for detecting the speed of the vehicle;
The speed detected by the vehicle speed sensor is calculated as the number of rotations of the cooling fan, and when the number of rotations exceeds the number of rotations of the pump motor detected by the motor rotation number detection means, it is determined that the assist capability is present. When the number of rotations of the cooling fan is equal to or less than the number of rotations of the pump motor, a determination unit that determines that the assist capability is absent
The vehicle engine cooling system according to claim 1, comprising: The assist ability detecting means includes
Fan rotation speed detection means for detecting the rotation speed of the cooling fan;
Motor rotation number detecting means for detecting the rotation number of the pump motor;
A vehicle speed sensor for detecting the speed of the vehicle;
When the rotation speed of the cooling fan detected by the fan rotation speed detection means exceeds the rotation speed of the pump motor detected by the motor rotation speed detection means, it is determined that the assist capability is present, and the vehicle speed sensor The vehicular engine cooling system according to claim 1, further comprising a determination unit that determines that the assist capability is absent when a predetermined speed or less is detected. A water pump for circulating engine coolant, which is the propulsion source of the vehicle,
A pump motor for driving the water pump;
Temperature detecting means for detecting the temperature of the coolant;
A radiator for cooling the coolant circulated by the water pump;
A cooling fan for cooling the radiator;
A clutch for intermittently connecting the cooling fan to the pump motor;
When the detected temperature of the temperature detecting means is equal to or higher than a predetermined temperature, the clutch is connected to connect the pump motor and the cooling fan, and when the detected temperature of the temperature detecting means is lower than the predetermined temperature, the clutch is Control means for shutting off the pump motor and the cooling fan by shutting off;
The cooling fan is provided between the pump motor and the cooling fan, and when the cooling fan is subjected to external air pressure to rotate faster than the pump motor, the cooling fan is connected to the pump motor and receives the external air pressure. A vehicle engine comprising a one-way clutch that disconnects the cooling fan from the rotary shaft of the pump motor when the rotational speed of the cooling fan rotating is lower than the rotational speed of the pump motor Cooling system.   6. The vehicular engine cooling system according to claim 1, wherein the number of revolutions of the pump motor is controlled to change in accordance with the detected temperature of the temperature detecting means.   7. The pump motor according to claim 1, wherein the number of revolutions of the pump motor is controlled so as to change depending on a difference between an inlet side temperature and an outlet side temperature of the coolant. The engine cooling system for vehicles described in 1.   The vehicle engine cooling system according to any one of claims 1 to 7, wherein the rotation transmission from the pump motor to the water pump is based on a magnetic coupling.   The vehicle engine cooling system according to any one of claims 1 to 8, wherein the pump motor is configured to be started later than when the engine is started.   In addition to the cooling fan, a cooling fan for cooling the radiator or the object to be cooled other than the radiator is provided, and the motor for driving the other cooling fan is not required to drive the other cooling fan. The vehicle engine cooling system according to any one of claims 1 to 9, further comprising a motor generator that functions as a generator when receiving rotational force from the other cooling fan.

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