JPS6120253Y2 - - Google Patents

Description

[Detailed Description of the Invention] The present invention relates to a cooling fan for an engine of an automobile or the like.

BACKGROUND ART In engines such as automobiles, water-cooled or air-cooled cooling systems are used to release heat loss generated during engine operation.
In these cooling systems, a cooling fan is used for the purpose of improving the heat dissipation effect, but this cooling fan is generally directly connected to the crankshaft of the engine. Therefore, the rotational speed of the cooling fan is determined centrally by the rotational speed of the engine crankshaft, and it is not possible to control the rotational speed of the cooling fan according to the temperature state of the engine. It was not possible to reduce the fan noise.

Conventionally, therefore, an electromagnetic coupling is interposed between the crankshaft and the fan, and the fan is rotated by magnetic force.When the rotational resistance of the fan becomes greater than the attractive force of the magnet, slipping occurs and the fan rotates at high speeds. Devices have been proposed to reduce noise.

However, in this conventional device, the fan rotates even when the engine is started, blowing out unnecessary air, and even if the engine overheats for some reason, a certain amount of air cannot be obtained. Additionally, engine noise tends to be louder when the engine is cold.

For this purpose, for example, Japanese Patent Application Laid-Open No. 49-30723 and Japanese Patent Application Laid-open No. 52-46240 disclose techniques for controlling a cooling fan using a magnetic material and a magnetic material. However, if a magnetic material and a magnetic material are simply used in this way, it is difficult to adjust the distance between the two, and there is also a delay in operation, making it impossible to control the air volume quickly.

Therefore, the purpose of the present invention is to achieve fast operation speed and
To provide an engine cooling fan whose air volume can be easily adjusted.

The cooling fan according to the present invention has a bracket that is slidably attached to a drive shaft such as a crankshaft, and a bracket that is supported by a bearing and is attached to the drive shaft, and both brackets are equipped with a magnet and magnetic material, respectively. The cylinder device is attached to the body to form a magnetic coupling, is equipped with an engine temperature state detection means, and is provided with a cylinder device that slides a bracket on the drive shaft in the axial direction in response to the engine temperature state detection means.

Therefore, if the engine temperature is low,
Since the engine temperature state detection means does not operate the cylinder device, the magnet and magnetic body are separated.
The fan does not rotate because it is not coupled by magnetic force. However, when the temperature of the engine becomes high, the cylinder device is actuated by a signal from the engine's temperature detection means, and the magnet and the magnetic body are brought closer to each other, so that the fan immediately rotates. Therefore, there is no delay in operation, and air volume control can be performed promptly. Furthermore, since it is operated mechanically, the gap between the magnet and the magnetic body can be easily controlled, and slippage does not occur due to fan resistance. That is, since the gap between the magnetic couplings can be mechanically adjusted, suitable air volume control can be performed.

When implementing the present invention, it is preferable to use an engine coolant temperature switch as the engine temperature state detection means. As the cylinder device, it is preferable to use an air cylinder operated by compressed air from a brake air tank, and to use a magnetic valve that is opened and closed by a temperature switch.

Embodiments of the present invention will be described below with reference to the drawings in comparison with a conventional device.

FIG. 1 shows a conventional cooling fan, in which a bracket 2 is attached to the tip of a drive shaft 1 of a crankshaft or the like, and a magnetic material 3 is embedded in one surface of the bracket. On the other hand, drive shaft 1
A permanent magnet 6 is attached to a bracket 5, which is rotatably supported by a bearing 4, opposite the magnetic body 3, thereby forming a magnetic coupling. A fan 7 is attached to this bracket 5 to serve as a cooling fan.

In this conventional cooling fan, the fan 7 is driven via the magnetic coupling as the drive shaft 1 rotates, so as the rotation of the drive shaft increases, the resistance of the fan causes the fan to slide against the magnetic coupling. occurs and when the resistance of the fan reaches a certain value, the rotational speed of the fan will no longer increase. Therefore, although it is possible to suppress noise when the fan rotates at high speed, the fan rotates even when the engine is started, which is undesirable.

Therefore, the present invention provides a device in which the coupling force of a magnetic coupling can be mechanically adjusted.

FIG. 2 shows an embodiment of the present invention, in which a spline or long key 12 is formed on the drive shaft 11, and a bracket 13 is engaged with the spline or long key 12 so that it can rotate and slide freely. It's attached. A magnetic material 14 is attached to this bracket 13, and a pawl 16 is engaged with this bracket 13 via a thrust bearing 15.

On the other hand, a bracket 18 is rotatably supported at the tip of the drive shaft 11 via a radial bearing 17, and a fan 19 is attached to this bracket 18. Furthermore, a dust seal 20 is attached to the tip of the shaft 11 to prevent dust between it and the bracket. And this bracket 18
On the side surface, a permanent magnet 21 is placed opposite the magnetic material 14.
is attached, forming a magnetic coupling.

The pawl 16, which engages the bracket 13, is connected to a piston 23 of an air cylinder 22, which is connected to an air tank 25 via a magnetic valve 24. This magnetic valve 24 is controlled by a temperature switch 26 provided at a temperature measuring section for cooling water or the like.

Since this device is configured as described above, when the bracket 13 is in the state shown in the figure pushed out by the spring 27, the gap d between the magnetic material 14 and the permanent magnet 21 is small, and the gap between the two is small. It constitutes a magnetic coupling. Therefore, Juan 1
The shaft 9 rotates in response to the rotation of the drive shaft 11, and when the number of revolutions exceeds a certain level, it slips and cannot rotate any further.

However, when the engine is cold or cold, such as when starting the engine, the temperature switch 26 detects this and switches the magnetic valve 24. There, the air cylinder 22 communicates with the air tank 25, and the piston 23 moves in the direction of arrow A in the figure, so that the bracket 13 is separated from the bracket 18 via the pawl 16 against the force of the spring 27. Therefore, the gap d between the magnetic material 14 and the permanent magnet 21 becomes too large, and the magnetic coupling is broken, causing the fan 1 to
9 is not driven.

Therefore, the warm-up time when the engine is cold is shortened, and engine noise is also reduced.

In this embodiment, an air cylinder is used as a means for moving the bracket 13, but a hydraulic cylinder may also be used. Also, if you use electromagnets instead of permanent magnets and adjust the strength of the coupling by controlling the current according to the temperature,
The rotation speed of the fan can be controlled to always be optimal.

Next, in another embodiment of the present invention shown in FIG. 3, in addition to the above-described device, the brackets 13 and 18 can be directly connected mechanically when necessary, and an additional device is provided on the outside of the bracket 13. Attach the sliding member 30 and insert a claw 3 at the tip of the sliding member 30.
1 is formed. A claw 32 is also formed on the side of the bracket 18 so that the two engage with each other.

Furthermore, if the air cylinder 22 is set to move in two stages, when the water temperature rises, the claw 1
6 moves in the direction of arrow B, the sliding member 30 is pushed out by the spring 33, the pawls 31 and 32 engage, and the fan is driven directly connected to the drive shaft. Therefore, sufficient air volume can be obtained and engine overheating can be prevented.

Since the present invention is constructed as described above, the magnetic coupling is connected and disconnected depending on the cooling state, and when necessary, it is directly connected mechanically to drive the fan, which prevents noise and prevents engine overflow. Cool and can completely prevent overheating. This also has the effect of reducing the horsepower consumed by the engine due to the drive of the fan.

[Brief explanation of the drawing]

Fig. 1 is a cross-sectional side view showing a conventional cooling fan, Fig. 2 is a cross-sectional side view of main parts showing one embodiment of the cooling fan of the present invention, and Fig. 3 is a main part showing another embodiment of the present invention. FIG. 11... Drive shaft, 12... Spline or long key, 13... Bracket, 14... Magnetic material, 18
... Bracket, 19 ... Fan, 21 ... Permanent magnet, 22 ... Air cylinder, 24 ... Magnetic valve, 25 ... Air tank, 30 ...
Sliding member, 31, 32...claw.

Claims (1)

[Scope of utility model registration request] It has a bracket that is slidably attached to the drive shaft of a crankshaft, etc., and a bracket that is supported by a bearing on the drive shaft and has a fan attached to it, and a magnet and a magnetic material are attached to each of the brackets to form a magnetic coupling. What is claimed is: 1. A cooling fan for an engine, comprising: an engine temperature state detection means; and a cylinder device that slides a bracket on a drive shaft in the axial direction in accordance with the engine temperature state detection means.