JPS6065223A - Cooling device of engine - Google Patents

Abstract

PURPOSE:To both cool an engine and prevent overcooling of the engine when it is driven at a high speed, by coupling a cross flow fan in a radiator shroud to an oil hydraulic motor and connecting an oil hydraulic pump, connected to the oil hydraulic motor through a selector valve controlled to be opened and closed by the temperature of cooling water, to an engine through a fluid coupling which controls the maximum speed of the oil hydraulic pump. CONSTITUTION:An oil hydraulic motor 7, being coupled to a cross flow fan 1 arranged along the direction of width of a car body in a radiator shroud 4, is connected to an oil hydraulic pump 6 through a forward path 8 and a return path 11 which are connected by a selector valve 10 opening as the temperature of cooling water rises. A fluid coupling, through which the oil hydraulic pump 6 is coupled to the output shaft of an engine, restricts the maximum speed of the oil hydraulic pump. In this way, overcooling of the engine is prevented when it is driven at a high speed.

Description

[Detailed description of the invention] The present invention relates to an engine cooling device.

Water-cooled and air-cooled engine cooling systems are available. A water-cooled engine has a radiator, and by forcing air into the two radiators, cooling water passing through the radiator radiates heat. An axial fan or cross-flow fan is used to force air into the radiator.

An axial fan has a circular air flow, whereas a cross flow fan can be arranged along the inside of the vehicle body, making it possible to uniformly send cooling air to the entire surface of the radiator.

For this reason, crossflow fans are suitable for long nose vehicles with low vehicle height.

An example using a cross flow fan is, for example, Japanese Patent Application Laid-open No. 5
Publication No. 4-110519 and JP-A-57-16311
It is disclosed in Publication No. 8. These conventional examples use the rotational torque of an electric motor or an engine as a power source for the cross flow fan. When an electric motor is used, the load on the battery and alternator increases, which adversely affects other electronic auxiliary equipment, and requires a larger battery or the like. Furthermore, when using the rotational torque of the engine by connecting it to a fan using a belt, there is a great risk that the fan on the engine side and the cross-flow fan casing on the vehicle body will come into contact with each other due to the difference in vibration between them. The mounting position is also limited by its relationship with the crankshaft.

This invention is intended to solve the above-mentioned problems of the prior art. Basically, the cross flow fan is operated by hydraulic pressure, and the hydraulic pressure is obtained by an oil pump driven by an engine. , using technical means to control the rotation of the oil pump with a fluid coupling. By interposing a fluid coupling between the engine and the oil pump, the oil pump's discharge volume can be held constant even when the engine is running at high speeds, keeping the crossflow fan's rotation constant and preventing engine overcooling. can. As a result, even if the engine cooling water temperature is high and the oil motor is configured to have a capacity that allows the crossflow fan to secure the cooling air required during engine idling, excessive cooling air will not be sent to the engine during high engine rotation.

Embodiments of the invention will be described with reference to the accompanying drawings.

In FIG. 1, reference numeral 1 denotes a cross flow fan arranged along the inside direction of the vehicle body. A radiator 2 and/or a cooler condenser 3 are placed in front of the crossflow fan 1. The duplexer 4 guides the air passing through the radiator 2 to the crossflow fan 1 and forces the air to the engine 5.

The drive system of the cooling device is shown in FIG. An oil pump 6 driven by the output shaft of the engine 5 is connected to an oil motor 7 which is made and connected to the shaft of the cross flow fan 1, and oil from the oil motor is returned to the oil pump 6. A filter 9 and a switching valve 10 are provided on an outgoing path 8 from the oil pump 6 to the oil motor 7. The switching valve 10 allows the flow of oil on the outward path 8 to be short-circuited to the return path 11 from the oil motor 7 to the oil pump 6 without being supplied to the oil motor T. The outward path B is piped in the width direction of the vehicle at a position in front or behind the cross flow fan 1 or the radiator 2 and the condenser 3 to cool the oil.

In the example shown in FIG. 3, oil from the oil motor 7 is returned to the oil pan or oil tank 12, and the oil is supplied to the oil motor 7 by the oil pump 6. The switching valve 10 has its opening and closing controlled in response to signals from a water temperature sensor 13 and a cooler compressor high pressure sensor 14. Such control makes it possible to blow air according to the engine temperature. That is, for example, during engine cooling, the switching valve 10 is opened, the outgoing path 8 from the oil pump 6 is short-circuited to the incoming path 11 from the oil motor 7, and the rotation of the cross flow fan 10 is interrupted.

FIG. 4 shows an example in which the radiator shutter 15 and the shroud 4 are movable. FIG. 5 shows a drive circuit for the cooling device shown in FIG. 4.

A first switching valve 10 and a second switching valve 16 are arranged in parallel with the first switching valve 10 in the outward path 8 from the oil pump 6 to the oil motor 7, and the first switching valve 10 is connected to a water temperature sensor 13 and a cooler compressor high pressure sensor. The second switching valve 16 is controlled to open and close according to signals from the water temperature sensor 13 and the vehicle speed sensor 1T. 1st
The switching valve 10 is connected to the hydraulic motor T of the cross flow fan 1 and the drive cylinder 18 of the radiator shutter 15. Further, the first switching valve 10 is connected directly to the return path 11, so that the oil pump 6 can be short-circuited to the oil tank 12.

The second switching valve 16 is connected to the drive cylinder 1 of the movable shroud 4.
9 and can be short-circuited with the return path 11. In the example shown in FIGS. 4 and 5, when the water temperature and high pressure compressor values are high, the cross flow fan 1 is operated and the radiator shutter 15 is opened, and when the respective values are low, the first switching valve 10 is activated. This short-circuits the outgoing path 8 to the incoming path 11, deactivates the cross flow fan 1, closes the radiator shutter 15, and interrupts the air blowing to the engine. Similarly, when the vehicle speed is low and the radiator water temperature is high, the oil from the oil pump 6 is transferred to the cylinder 19 via the second switching valve 16.
The shroud 4 is closed, and the cross flow fan 1 and the open radiator shutter 15 send cooling air to the engine. Further, when the vehicle speed is high, the movable shroud 4 and the radiator shutter 15 are opened, and the cross flow fan 1 is deactivated to send the wind cut by the vehicle to the engine.

As shown in FIG. 4, the lower end of the upper movable shroud 4 is arranged to be located in front near the horizontal plane passing through the center of the rotation axis of the cross flow fan 1, and when it is opened, it moves to the position shown by the imaginary line, and , when the lower shroud 20 is disposed below the shroud 20 substantially parallel to the horizontal plane, the cross-flow fan 1 is rotated counterclockwise in order to reduce the rotational resistance due to the wind of the cross-flow fan and increase the air blowing efficiency. let On the other hand, as shown in FIG. 6, when the front of the lower shroud 20 extends close to the horizontal plane and the lower end of the movable shroud 4 is located near and behind the flow fan 1, Rotate the flow fan 1 clockwise.

In order to prevent overcooling of the engine even when the engine speed is high, the cross flow fan speed is suppressed by 10 times, and
If the engine temperature is high even though the engine speed is low (for example, during idling), it is necessary to ensure the crossflow fan 10 rotations as much as possible. For this reason, a fluid coupling 21 is arranged between the engine output shaft and the oil pump 6, as shown in FIG. The fluid coupling 21 causes a slipping phenomenon when the rotational speed of the engine output shaft exceeds a certain value, suppresses the maximum rotational speed of the oil pump 6 to a constant value, and has good transmission efficiency of rotational torque when the engine is running at low rotational speeds. As a result, the 8th
The cross-flow fan rotation speed (Nf) relative to the engine rotation speed (NK) is obtained as shown by the solid line in the figure. As is clear from the figure, the number of rotations of the cross flow fan 1 can be suppressed when the engine is running at high speeds, and the minimum number of rotations of the cross flow fan 1 can be ensured when the engine is running at low speeds. Pottery,
Since FIG. 7 is substantially the same as the example shown in FIG. 3 with a fluid coupling 21, the operation is the same as the example shown in FIG. 3, and the explanation thereof will be omitted. Instead of the fluid coupling, a variable type hydraulic pump 6 in which the amount of oil discharged is not electrically proportional to the engine speed may be used to obtain the same effect.

Even if the engine speed is low and the engine temperature is high, in order to more reliably secure the crossflow fan 10 rotation speed when the engine temperature is high, an electric motor that operates only in this state may be connected to the crossflow fan 1. in this case,
By operating the electric motor, a larger amount of cooling air can be supplied to the engine. This level of electric motor operation does not adversely affect other electronic auxiliary equipment.
There is no need to increase the size of the battery or alternator.

Without providing an electric motor, the capacity of the oil motor can be configured so that the engine cooling water is at a high temperature and the cross 70-fan can supply the cooling air required during engine idling. Even in this case, the fluid coupling functions to prevent excessive air from being sent to the engine when the engine rotates at high speeds, so overcooling of the engine can be prevented.

[Brief explanation of drawings]

Fig. 1 is a side view of one example of this invention, Fig. 2 is a plan view thereof, Fig. 3 is an explanatory diagram showing an operating circuit, Fig. 4 is a side view showing another example, and Fig. 5 is its operating circuit. FIG. 6 is a side view showing the example shown in FIG. 5 with the shroud installed differently, FIG. 7 is a side view showing another example, and FIG. It is a figure showing the relationship with the number of rotations of a crossflow fan. In the diagram: 1...Cross flow fan, 2...Radiator, 4...Movable shroud, 5...Engine, 6
...Oil pump 7...Oil motor, 10.16...
Switching valve, 13, 14. 17... sensor, 15...
radiator shutter. Agent Patent Attorney Hideaki Kuwahara

Claims (1)

[Claims] a radiator, a crossflow fan disposed in the shroud and close to the radiator, an oil motor that rotates the crossflow fan, an oil pump that supplies hydraulic oil to the oil motor and is driven by the engine, the oil motor; An engine cooling circuit that connects the oil pump (a switching valve that is connected and controlled to open and close depending on the cooling water temperature, and a fluid coupling that is arranged between the oil pump and the engine and that controls the maximum rotation speed of the oil pump) Device.