JPH0660658B2 - Fan coupling device for internal combustion engine - Google Patents

Description

Description: BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to an improvement in a temperature sensing type fan coupling device used for a cooling fan of an internal combustion engine for automobiles.

2. Description of the Related Art For example, in a cooling fan for an internal combustion engine for an automobile, a temperature-sensing fan coupling device capable of controlling a rotation speed according to an air temperature after passing a radiator is widely used.

FIG. 5 shows an example of the conventional fan coupling device. 1 is a hollow drive shaft equipped with a V belt pulley 2 and 3 is rotatably supported on the drive shaft 1 via a bearing 4. A housing 6 having a cooling fan 5 mounted on the outer periphery thereof is a rotor fixedly attached to the front end of the drive shaft 1 and housed in the housing 3. The inside of the housing 3 is stored in the front by a partition plate 7. A chamber 8 and a rear working chamber 9 accommodating the rotor 6 are separated from each other.
The outer peripheral portion of the rotor 6 and the inner wall of the housing 3 facing the outer peripheral portion of the rotor 6 are engaged with each other in a multi-stage labyrinth groove 1
0 and 11 are formed, and the viscous resistance of the working fluid is obtained between the both 10 and 11 to act as a fluid coupling.
In addition, the partition plate 7 is formed with a circulation hole 12 that communicates the storage chamber 8 and the working chamber, in the vicinity of the outer peripheral portion of the disk-shaped partition plate 7 and long in the radial direction. ing. Further, as shown in FIG. 6, a rotary shaft 14 to which a central end of an outer spiral bimetal 13 is fixed is supported at approximately the center of the side cover 3a of the housing 3. This rotating shaft 14
A valve plate 15 that opens and closes the flow hole 12 is supported on the inner end of the valve plate 15.
The circulation of the working fluid returned to the storage chamber 8 through the return passage 16 after passing through the labyrinth grooves 10 and 11 is controlled according to the air temperature after passing through the radiator (not shown).

That is, when the air temperature is low, the valve plate 15 closes the flow hole 12 to stop the circulation of the working fluid as shown by the solid line in FIG. Therefore, the amount of working fluid sent to the labyrinth grooves 10 and 11 is reduced,
Therefore, the torque transmitted from the rotor 6 to the housing 3 is reduced and the cooling fan 5 rotates at a low speed. On the other hand, when the air temperature is high, the valve plate 15 opens the flow hole 12 as shown by the alternate long and short dash line in FIG.
Flow into the working chamber 9. Therefore, labyrinth groove 1
The working fluid is sufficiently supplied to the 0 and 11 parts, the transmission torque from the rotor 6 to the housing 3 is increased, the difference in relative speed between the two is reduced, and the cooling fan 5 rotates at a high speed (Japanese Patent Laid-Open Publication No. Sho. 60-184724, etc.).

DISCLOSURE OF THE INVENTION Problems to be Solved by the Invention However, in the above-mentioned conventional apparatus, the valve plate 15 is rotated in the circumferential direction of the partition plate 7 and is provided near the outer peripheral portion of the partition plate 7. ON-OF the flow hole 12
It is designed so that it opens and closes suddenly in a F manner. That is, when the flow hole 12 is opened, the working fluid starts to flow from the storage chamber 8 into the working chamber 9, and the rotation speeds of the housing 3 and the cooling fan 5 increase. The centrifugal force that acts on the fluid increases, and the working fluid that flows from the flow holes 12 into the working chamber 9 rapidly increases. In other words, since the flow rate of the working fluid moving from the storage chamber 8 to the working chamber 9 cannot be finely adjusted, the rotation speed of the cooling fan 5 cannot be controlled with high accuracy according to the air temperature. Therefore, for example, immediately after the valve plate 15 is opened, the working fluid in the working chamber 9 suddenly increases and becomes excessively large, and as shown in FIG. There is a problem that 5 is rotated at a higher speed than necessary and is overcooled. Further, excessive rotation of the cooling fan 5 causes a reduction in engine output and noise. The rapid increase of the working fluid in the working chamber 9 reduces the difference in the number of rotations between the rotor 6 and the housing 3, and the working chamber 9 is returned to the storage chamber 8 via the return passage 16.
Needless to say, this is partly because the flow rate returned to the chamber is reduced.

Means for Solving the Problems The present invention has been devised in view of the above-mentioned problems of the related art. In the inside of a housing rotatably supported by a drive shaft, the inside of the housing is provided with a storage chamber and a working chamber. And a partition plate that is separated from the chamber, a through hole that communicates the chambers with each other is formed in the partition plate, and the partition plate is rotatably supported about the center of the side portion of the housing through a temperature-sensitive member. An arm is fixed to the inner end of the shaft, a valve plate is rotatably supported on the inner side of the housing, and one side piece of the valve plate is rocked on the end of the arm via an engaging means. It is characterized in that it is movably engaged and that the other side piece of the valve plate is configured to slide and open and close the flow hole in the radial direction of the partition plate.

According to the present invention having the above-described configuration, when the air temperature near the temperature sensing member is low, for example, when the cold start is performed, the valve plate closes the flow hole with the arm through the engaging means while the other side piece is substantially horizontal. Held in position. Therefore, the inflow amount of the working fluid from the storage chamber to the working chamber is reduced, and the transmission torque to the housing is reduced. On the other hand, when the temperature of the air near the temperature-sensing member becomes higher than the set temperature, the other side piece of the valve plate slides toward the outer peripheral edge along the substantially radial direction of the partition plate as the arm rotates in the circumferential direction. Gradually open the flow hole from the inner end. In this way, since the flow holes can be opened from the inside, the flow rate of the working fluid flowing from the storage chamber into the working chamber can be controlled with high accuracy according to the air temperature.

Embodiment Hereinafter, an embodiment of the present invention will be described in detail with reference to the drawings.
The same parts as those of the fan coupling device of FIG. 5 described above are designated by the same reference numerals, and the duplicated description will be omitted.

FIG. 1 shows a first embodiment of the present invention, 1 is a hollow drive shaft, 3 is a housing having a cooling fan 5 on the outer circumference, and 6
Is a rotor, 7 is a partition plate that divides the housing 3 into a storage chamber 8 and a working chamber 9, 10 and 11 are labyrinth grooves, and 12 is a partition plate 7, and the storage chamber 8 and the working chamber 9 are drilled. Is a square through hole communicating with and 13 is a spiral bimetal which is a temperature sensitive member that operates according to the temperature of the surrounding air, and 14 is a bearing in the center of the cover 3a fixed to the opening of the housing 3 by caulking. The rotation shaft rotates forward and backward as the bimetal 13 expands and contracts.

Then, the inner end portion 14a of the rotating shaft 14 facing the storage chamber 8
As shown in FIG. 2 and FIG. 3, one end 21a of a relatively long rectangular arm 21 is fixed to this, and the other end 21b of this arm 21 has an engaging means at the center of the outer surface. The engaging pin 22 which is a part of the above is provided. On the inner side surface of the cover 3a, one side piece 25 of the substantially L-shaped valve plate 23 that opens and closes the flow hole 12 is attached to the pivot pin 2.
It is rotatably supported via 4. Specifically, the valve plate 23 is provided with a relatively short one side piece 25 and a relatively long step-shaped other side piece 26, and the side bent pieces 25, 26 have central bent portions. The pivot pin 2 provided
4 is the center O of the flow hole 12 with respect to the radial connection X connecting the center P of the rotary shaft 14 and the center O of the flow hole 12.
It is arranged on an intersection line Y that vertically intersects with the above and at an angle position of about 30 ° from the connection line X centered on the above P. Further, a long hole 27 which is a part of engaging means with which the engaging pin 24 is movably engaged is formed at the center of the end of the one side piece 25. On the other hand, the other side piece 26 is arranged in front of the flow hole 12 of the partition plate 7, and slides on the partition plate 7 substantially along the connection X as the arm 21 rotates in the circumferential direction. It is formed to open and close the flow hole 12.

Therefore, when the air temperature near the spiral bimetal 13 is low, for example, at the time of starting the cold machine, the arm 21 as shown in FIG.
Rotates in the clockwise direction in the figure via the rotary shaft 14 and stops at the position shown in the figure. It is blocked.

Therefore, the inflow amount of the working fluid from the storage chamber 8 to the working chamber 9 is reduced, so that the transmission torque to the housing 3 is reduced and the cooling fan 5 is rotated at a low speed. Next, spiral bimetal 13
When the air temperature in the vicinity becomes higher than the set temperature, when the arm 21 rotates counterclockwise in the figure as shown in FIG. 3, the engagement pin 22 slides in the long hole 27 to slide the long hole. The end piece 27 hits the end edge, and the one side piece 25
Valve plate 23
Gradually rotates clockwise around the pivot pin 24 in the figure. Therefore, the other side piece 26 of the valve plate 23 slides in the direction of the outer peripheral edge of the partition plate 7 along the connection line x, and the flow hole 12 is provided on the center side in the radial direction of the partition plate 7 so that the working fluid shown in FIG. It is gradually opened from the inner end 12a which is formed at the substantially same position as the liquid level L. In this way, the flow hole 12 can be opened from the inner end 12a, so that the flow rate of the working fluid flowing from the storage chamber 8 into the working chamber 9 can be controlled to an optimum flow rate according to the air temperature. As a result, the rotation speed of the cooling fan 5 has a gradual characteristic according to the air temperature as shown in FIG. Note that the alternate long and short dash line on the partition plate 7 in FIGS. 2 and 3 indicates the liquid level L of the working fluid.

On the other hand, when the flow hole 12 is closed from the open state,
It gradually closes from the outer end 12b and closes slowly. Therefore, similarly to the above, the flow rate of the working fluid can be controlled with high accuracy according to the air temperature.

In addition, one side piece 25 of the arm 21 and the valve plate 23.
The length of the other side piece 26, the drilling direction of the long hole 27, the length, etc. are determined by the set temperature of the bimetal 13, etc., but the valve plate 23 is not limited to the bent shape, It may be a thin plate.

EFFECTS OF THE INVENTION As is clear from the above description, according to the fan coupling device for an internal combustion engine of the present invention, the flow hole of the partition plate can be gradually opened and closed from the inner and outer ends by the valve plate. The flow rate of the working fluid flowing from the storage chamber into the working chamber can be adjusted according to the air temperature, and the rotation speed of the housing can be controlled with high accuracy according to the air temperature. Therefore, overcooling of the engine can be reliably prevented, and unnecessary rotation of the housing is prevented,
Reduced engine output and noise generation are eliminated.

[Brief description of drawings]

FIG. 1 is a cross-sectional view of an essential part showing an embodiment of a fan coupling device for an internal combustion engine according to the present invention, FIG. 2 is a front view of the essential part showing a closed state of a valve plate of this embodiment, and FIG. FIG. 4 is a front view of an essential part showing the opening operation state of the valve plate.
FIG. 5A is a graph showing a cooling fan rotation speed characteristic of this embodiment, FIG. 7B is a graph showing a conventional cooling fan rotation speed characteristic, and FIG. FIG. 6 is a front view showing the conventional device with a part thereof cut away. 1 ... Drive shaft, 3 ... Housing, 7 ... Partition plate, 8 ...
... Storing chamber, 9 ... Operating chamber, 12 ... Flow hole, 13 ... Bimetal (temperature sensitive member), 14 ... Rotary shaft, 21 ... Arm, 22 ... Engaging pin (engaging means), 23 ...... Valve plate, 24 ...... Pivot pin, 25 ...... One side piece, 26 ......
Other side piece, 27 ... elongated hole (engaging means).

Claims (1)

[Claims] 1. A partition plate for partitioning the interior of the housing into a storage chamber and a working chamber is provided inside a housing rotatably supported by a drive shaft, and the partition plate communicates both chambers. An arm is fixed to an inner end portion of a rotary shaft which is provided with a through hole and which is pivotally supported substantially at the center of a side portion of the housing and rotates via a temperature sensing member. The valve plate is rotatably supported, one end of the valve plate is swingably engaged with the end of the arm through an engaging means, and the other end of the valve plate partitions the flow hole. A fan coupling device for an internal combustion engine, which is configured to slide and open and close in a substantially radial direction of a plate.