JPH01176819A - Temperature sensitive type fluid fan coupling device - Google Patents

Abstract

PURPOSE:To aim at smoothing the rise-up of the rotational speed and at enhancing the transmission capacity by providing a dynamic pressure generating part in the outer peripheral section of a rotary plate in a fluid coupling, a small torque transmission part on one side of the rotary plate and a large torque transmission part on the other side of the rotary plate, and by supplying liquid into the large torque transmission part after the liquid being filled in the small torque transmission part. CONSTITUTION:There are provided a small torque transmission part on one side of a rotary plate 36 in a fluid coupling, a large torque transmission part 38 and a dynamic pressure generating part 39 composed of an outer peripheral inclined groove 38 and a radial communication hole on the other side of the rotary plate 36. In this arrangement, liquid led into a rear chamber during rotation is filled in a meshing section in the small torque transmission part 37 centrifugal force urging the liquid radially outward, and thereafter it is fed into a meshing section in the large torque transmission section 38 after overflowing from a piercing hole 42. Accordingly, it is possible to give a satisfactory rise-up characteristic during rise-up of the rotational speed and to exhibit a sufficient drive force upon maximum output operation.

Description

DETAILED DESCRIPTION OF THE INVENTION The present invention relates to a temperature-sensitive fluid fan coupling device, and more particularly to a temperature-sensitive fluid fan coupling device for mounting a radiator cooling fan or the like in an automobile.

(Prior Art) In general, a temperature-sensitive fluid fan coupling device has a function of adjusting the fan rotation speed by changing the slip ratio of a fluid coupling using the temperature sensing operation of a temperature sensing element. , for example, between a radiator cooling fan of an automobile and a fan drive source. Such a temperature-sensitive fluid fan coupling device increases the fan rotation speed to forcibly send cooling air to the radiator when the temperature of the air passing through the radiator increases when the vehicle is running at low speed or idling. On the other hand, when the temperature of the air passing through the radiator becomes low during normal driving, the fan is prevented from rotating more than necessary to improve fuel efficiency, reduce fan noise, and shorten warm-up time. In addition, when increasing the fan rotation speed, if load torque is suddenly applied to the idling engine, it is likely to cause engine stalling, etc.
A fan coupling device is required to have a smooth start-up characteristic that gradually increases the fan rotation speed.

A conventional temperature-sensitive fluid fan coupling device of this type is described in, for example, Japanese Patent Laid-Open No. 59-86722, as shown in FIG. In FIG. 7, reference numeral 1 denotes a rotary plate constituting a fluid coupling, and the rotary plate 1 is rotatably housed in the rear chamber 3 of the fan casing 2. A plurality of annular protrusions 11, 12, 13, and 14 of different sizes are formed on the rotary plate l so as to become smaller sequentially toward the outside. It is adapted to engage with a plurality of annular recesses (not shown) formed in the. Further, a notch 15 having a predetermined width is formed in the outer circumference of the rotating plate 1, and the rotating plate 1 has a minute gap g between the outer circumferential surface 1a and the circumferential surface 1b adjacent to the notch 15.
The fan casing 2 faces the fan casing 2. That is, an attempt is made to reduce the power transmission area of the fluid coupling from the center of the rotating plate 1 toward the outer circumference. When the rotary plate 1 is driven to rotate, torque is transmitted from the rotary plate 1 to the fan casing 2 via a liquid (not shown) of a predetermined viscosity led out into the rear chamber 3 of the fan casing 2. The fan attached to the fan casing 2 and the fan casing 2 rotate upward. At this time, rear compartment 3
The liquid drawn into the interior is urged toward the inner circumferential wall surface 2a of the fan casing 2 by centrifugal force based on the rotation of the rotating plate 1 and the fan casing 2, and is retained in an annular shape on the outer circumferential side of the rotating plate 1. The effective power transmission area of is small,
Therefore, from a state in which the fan casing 2 rotates at a low speed due to bearing friction or the like, the number of rotations is gradually increased according to the amount of liquid introduced.

(Problems to be Solved by the Invention) However, in such a conventional temperature-sensitive fluid fan coupling device, the power transmission area of the fluid coupling decreases from the center of the rotating plate 1 toward the outer circumference. Therefore, when starting up the fan rotation speed, the torque transmitted from the rotary plate l to the fan casing 2 can be gradually increased from a small torque to improve the start-up characteristics. The side power transmission area was small, and the transmission torque at maximum output was small.

Therefore, there was a problem that sufficient fan driving force could not be obtained.

(Objective of the Invention) Therefore, the present invention provides a power transmission surface capable of transmitting large torque to a fluid coupling, and devises a route for the liquid supplied to the power transmission surface, thereby achieving good start-up characteristics and sufficient It is an object of the present invention to provide a temperature-sensitive fluid fan coupling device that can exhibit a high fan drive.

(Means for Solving the Problems) In order to achieve the above objects, the present invention provides a fan casing having a front chamber and a rear chamber partitioned by a partition plate, and a fan casing that is attached to the front part of the fan casing. a temperature sensing element that senses temperature in response to the temperature of the air received by the temperature sensing element; a liquid discharge mechanism that operates in response to the temperature sensing operation of the temperature sensing element and can lead liquid from the front chamber to the rear chamber; A fluid coupling that has a rotating shaft attached to the rear of the fan casing and a rotating plate fixed to the rotating shaft, and transmits torque from the rotating shaft to the fan casing via the rotating plate and liquid led into the rear chamber. and a liquid introduction mechanism that cooperates with a rotating plate of the fluid coupling to introduce liquid in the rear chamber into the front chamber, and the fluid coupling includes a small torque transmission section provided on one side of the rotating plate; The liquid derivation mechanism includes a large torque transmission section provided on the other side of the rotating plate, and a dynamic pressure generation section provided on the outer periphery of the rotating plate to separate the large torque transmission section and the small torque transmission section. After the liquid is supplied to the small torque transmission section and filled, it is supplied to the large torque transmission section.

(Function) In the present invention, the large torque transmission section and the small torque transmission section of the fluid coupling are separated by the dynamic pressure generation section provided on the outer periphery of the rotating plate, and the liquid from the liquid introduction mechanism is supplied to the small torque transmission section. After being filled, it is supplied to the large torque transmission section. Therefore, when the fan rotation speed is started up, the derived liquid is supplied to the small torque transmission section, and the transmission torque of the fluid coupling is gradually increased from the small torque to promote good startup characteristics.On the other hand, at the maximum output, the drawn liquid is supplied to the large torque transmission section. The discharged liquid is also supplied, and sufficient fan driving force is exerted.

(Example) Hereinafter, the present invention will be explained based on the drawings. 1 to 6 are diagrams showing one embodiment of the present invention, and are examples in which the present invention is applied to a coupling for a radiator cooling fan of an automobile.

First, the configuration will be explained. In FIG. 1.2, 21 is a fan casing, and the fan casing 21 has a radiator cooling fan (not shown) attached to its outer periphery and is disposed on the rear side of the vehicle body of the radiator 22. The fan casing 21 has a partition plate 23, and inside the fan casing 21 there is a front chamber 24 partitioned off by the partition plate 23.
and a rear chamber 25 are defined. A liquid 26 having a predetermined viscosity is stored in the front chamber 24 of the fan casing 21, and the liquid 26 is, for example, silicone oil with a small viscosity temperature coefficient. Reference numeral 27 denotes a temperature sensing body made of bimetal or the like, and the temperature sensing body 27 is formed in a spiral shape. The temperature sensing element 27 has one end 27a attached to the front part 21a of the fan casing 21 and the other end 27b connected to the central shaft 28. It deforms in response to the temperature of the air passing through it, and performs a temperature-sensing operation to rotate the central shaft 28. The center shaft 28 passes through the front part 21a of the fan casing 21 and is connected to a link 29 inside the front chamber 24, and the link 29 is connected to the center shaft 28.
At one swinging end 29a, which swings due to the rotation of the lead-out pipe 3,
It is rotatably connected to 1.

The outlet pipe 31 has a smooth liquid outlet passage 31 with a substantially circular cross section.
The outlet pipe 31 has a radial outer end opening 31b that opens into the rear chamber 25 and a radial inner end opening 31c that opens into the front chamber 24. The radiating outer end opening 31b of the outlet tube 31 is rotatably connected to the radiating outer end of the partition plate 23, and when the link 29 swings due to the temperature sensing operation of the temperature sensing element 27, the outlet tube 31 radiates. Inner end opening 3
1c is adapted to rotate in response to the temperature sensing operation of the temperature sensing element 27 so that it approaches and separates from the inner circumferential wall 21b of the fan casing 21. At this time, the fan casing 2
The liquid 26 in the fan casing 21
Since it is biased toward the side and retained, the radial inner end opening 31c sinks into the liquid 26 due to the rotation of the outlet pipe 31, and the liquid 26 is led out from the front chamber 24 through the outlet pipe 31 to the rear chamber 25. It is now possible to do so. That is, the central shaft 28, the link 29, and the lead-out pipe 31 are connected from the front chamber 24 to the rear chamber 25 according to the temperature sensing operation of the temperature sensing element 27.
A liquid ejection mechanism 32 is configured that can eject the liquid 26. In addition, the rear part 21 of the fan casing 21
A rotary shaft 33 is rotatably attached to C, and the rotary shaft 33 is rotationally driven by an engine (not shown) via a power transmission means 34 such as a pulley.

35 is a fluid coupling, and the fluid coupling 35 has a rotating plate 36 fixed to the rotating shaft 33 at the center and rotatably housed in the rear chamber 25. As shown in FIG. 3, the fluid coupling 35 includes a small torque transmitting section 37 provided on one side of the rotating plate 36, a large torque transmitting section 38 provided on the other side of the rotating plate 36, and a large torque transmitting section 38 provided on the other side of the rotating plate 36. and a dynamic pressure generating section 39 provided on the outer periphery of. The small torque transmitting portion 37 and the large torque transmitting portion 38 each have drive side uneven portions 37a and 38a formed on the rotary plate 36 to have a plurality of coaxial annular protrusions.
and driven side uneven parts 37b and 38b formed on the fan casing 21 so as to engage with the driving side uneven parts 37a and 38a with a minute gap, and the small torque transmission part 37 and the large torque transmission part 38 are connected to the rotating shaft. 3
3 rotates, torque is transmitted from the driving side uneven parts 37a, 38a to the driven side uneven parts 37b, 38b by fluid friction based on the viscosity of the liquid 26 in the rear chamber 25. That is, the fluid coupling 35 connects the rotating shaft 33 via the rotating plate 36 and the liquid 26 led out into the rear chamber 25.
The fan casing 21 is driven by transmitting torque from there to the fan casing 21.

Furthermore, the small torque transmitting portion 37 and the large torque transmitting portion 38 of the fluid coupling 35 have engaging surfaces S having mutually different areas.
S2 (corresponding to a power transmission surface), and the engagement surface S1 of the small torque transmission section 37 is smaller than the engagement surface S2 of the large torque transmission section 38. The engagement surface S2 of the large torque transmission section 38 has a sufficient area on the outer peripheral side of the rotary plate 36, so that a large torque can be transmitted when the maximum torque of the fluid coupling 35 is generated. Note that the engagement surface SI refers to the driving side uneven portion 37a and the driven side uneven portion 37.
The engagement surface S2 is a surface located between the driving side uneven portion 38a and the driven side uneven portion 38b.

In FIGS. 3 to 5, the dynamic pressure generating section 39 is attached to the outer periphery of the rotary plate 36 so as to have an inclination of a predetermined angle with respect to the communication hole 40 formed in the radial direction of the rotary plate 36 and the axis of the rotary plate 36. It consists of an inclined groove 41 formed. The communication hole 40 is connected to the rotating plate 3
The through hole 42 formed in 6 and the inclined groove 41 are made to communicate with each other, and the engaging portion of the small torque transmission section 37 is made to communicate with the inclined groove 41. During the rotation of the rotating shaft 33 (at this time, the radial ball bearing 4 described later
(The fan casing 21 is also rotating at a low speed due to the bearing friction of the fan casing 21, etc.) When the liquid 26 is led out from the liquid delivery mechanism 32 to the rear chamber 25, the liquid 26 is caused by the rotation of the fan casing 21 and the rotating plate 36. The force is applied radially outward by centrifugal force and is supplied to the engaging portion of the small torque transmitting portion 37, and is applied to the communication hole 40 as shown by arrow A in Fig. 3.4.
and flows to one side of the rotary plate 36 through the inclined groove 41. In addition, the liquid 2 from the liquid deriving mechanism 32
6 increases and the engaging portion of the small torque transmission section 37 is filled with the liquid 26, the liquid 26 flows into the through hole 4.
2. It flows into the inclined groove 41 through the path of the communication hole 40, and then overflows from the through hole 42 and is supplied to the meshing portion of the large torque transmission section 38.

Note that when both the small torque transmission section 37 and the large torque transmission section 38 are filled with the liquid 26, the liquid 26 flows into the fan casing 21 and the rotating plate 3 as shown by arrow B in FIG.
The rotating plate 36 is biased from the other side to the one side in accordance with the sliding speed (relative rotational speed) of the rotating plate 36. That is, the dynamic pressure generating section 39 generates a dynamic pressure in the liquid 26 in the inclined groove 41 from the other side of the rotating plate 36 to the one side, and the dynamic pressure causes the small torque transmitting section 37 and the large torque to be generated when the fan starts rotating. The transmission section 38 is separated and the liquid 26 is supplied to the small torque transmission section 37;
After being filled, it is supplied to the large torque transmission section 38.

On the other hand, as shown in FIG.
A dam 43 is engaged with the fan casing 21 , and the dam 43 is attached to the fan casing 21 on one side of the rotating plate 36 . The dam 43 is in sliding contact with the outer circumferential portion 36a of the rotary plate 36 at a speed corresponding to the sliding speed when the fluid coupling 35 is activated, and
The liquid 26 adhering to the fan casing 21 is wiped away and the liquid 26 is passed through the liquid passage 44 formed in the fan casing 21 to the front chamber 24.
It is planned to be introduced in That is, the dam 43 and the liquid passage 44 constitute a liquid introduction mechanism 45 that cooperates with the rotating plate 36 of the fluid coupling 35 to introduce the liquid 26 in the rear chamber 25 into the front chamber 24. The pumping action causes the liquid 26 to circulate through the front chamber 24, the liquid outlet mechanism 32, the rear chamber 25, and the liquid introduction mechanism 45.

Note that 46 is a bearing such as a radial ball bearing, and the bearing 46 supports the rotating shaft 33 while restricting movement of the fan casing 21 and the rotating shaft 33 in the axial direction. Seal rings 47 and 48 are respectively attached to the fan casing 21 and maintain the front chamber 24 or the rear chamber 25 liquid-tight.

Next, the effect will be explained.

When the rotating shaft 33 is driven by the engine via the power transmission means 34, the liquid 26 remaining in the rear chamber 25 is transferred from the rotating shaft 33 to the fan casing 2 by the fluid coupling 35.
Torque is transmitted to the fan casing 21 and the fan rotate at a relatively low rotation speed. At this time, the liquid 26 in the fan casing 21 is urged toward the inner circumferential wall 21b of the fan casing 21 based on the rotation of the fan casing 210 (by centrifugal force), and the liquid 2G in the front chamber 24 has the inner circumferential wall 21b as its bottom surface. At the same time, the liquid 26 adhering to the outer circumference 36a of the rotary plate 36 is wiped off by the dam 43 of the liquid introduction mechanism 45 and introduced into the front chamber 24 via the liquid passage 44. The amount of liquid 26 in 25 is reduced, the effective power transmission area of fluid coupling 35 gradually decreases, the sliding speed of fluid coupling 35 increases, and the fan rotation speed decreases. The part 31c is the fan casing 21
Slightly above the liquid level of the liquid 26 that accumulates in an annular shape,
In other words, it is located on the radially inward side, and the rear compartment 2
5 is urged from the other side of the rotary plate 36 to one side within the inclined groove 41 by the dynamic pressure generated by the dynamic pressure generating part 39, so that the liquid 26 is discharged from the meshing part of the large torque transmitting part 38. After this, the liquid 26 is discharged from the engagement portion of the small torque transmission portion 37 (see FIG. 5).

On the other hand, when the temperature of the passing air from the radiator 22 that is received by the front part 21a of the fan casing 21 increases, the temperature sensing element 27 deforms in response to the air temperature and performs a temperature sensing operation.
The outlet pipe 31 of the liquid outlet mechanism 32 rotates in accordance with the temperature sensing operation of the temperature sensing element 27. At this time, the radial inner end opening 31c of the outlet pipe 31 sinks into the liquid 26 while approaching the inner circumferential wall 21b of the fan casing 21, and then the liquid 26 staying inward from the radial inner end opening 31C is drawn out. Passage 31
4 is taken out from the front chamber 24 to the rear chamber 25 through a. Therefore, as the radiator passing air temperature increases,
The amount of liquid 26 in the rear chamber 25 is increased, the effective power transmission area of the fluid coupling 35 is increased, and the fan rotation speed is increased. That is, the fan rotation speed is adjusted in accordance with the temperature of the air passing through the radiator, which helps improve the fuel efficiency of the engine that is the driving source, shorten the warm-up time, and reduce fan noise.

Here, the liquid 26 from the liquid derivation mechanism 32 is transferred to the fluid coupling 3.
The operation of the fan rotation speed at startup will be explained in detail, including the path for supplying the fan. First, when the liquid 26 is led out from the liquid delivery mechanism 32 to the rear chamber 25, the liquid 26 is urged radially outward by centrifugal force based on the rotation of the fan casing 21 and the rotary plate 36, and the small torque transmission section 37
It is supplied to the engaging part of the

Next, as shown by arrow A in FIG.
0 and the inclined groove 41 to flow out to the liquid introduction mechanism 45 side. Furthermore, when the small torque transmitting section 37 is filled with the liquid 2G, the liquid 26 overflows through the through hole 42 and is supplied to the meshing part of the large torque transmitting section 38, and the liquid 26 flows into the small torque transmitting section 37 and the large torque transmitting section 38. is filled. Therefore, when the temperature of the air passing through the radiator increases and the fan rotation speed increases, the fluid coupling 35 starts transmitting torque from the small torque transmitting section 37 with a small power transmitting surface, and the fluid from the liquid deriving mechanism 32 After a predetermined time period corresponding to the derived amount, the large torque transmission section 38 with a large power transmission area
starts transmitting large torque. During this time, the small torque transmitting section 37 and the large torque transmitting section 38 gradually increase the transmitted torque according to the amount of liquid 2G filled, so that the rotational speed of the fan casing 21 and the fan can be smoothly increased from low speed. . At maximum output, large torque is transmitted by both the small torque transmitting section 37 and the large torque transmitting section 38, and sufficient run driving force is exerted.

In this way, in this embodiment, the small torque transmission section 37
The large torque transmitting section 38 is separated by the dynamic pressure generating section 39, and the liquid from the liquid deriving mechanism 32 is transferred to the small torque transmitting section 37.
Since the transmission torque is supplied to the large torque transmission section 38 after being filled and filled, the transmission torque can be gradually increased from a small torque when the fan rotation speed is started up, and good startup characteristics can be obtained. Fan driving force can be demonstrated. In this embodiment, the number of annular protrusions of the small torque transmitting part 37 is smaller than that of the large torque transmitting part 38, so that the engaging surface S1 is smaller than the engaging surface S2, but the heights of these annular protrusions are different. Needless to say, it may be anything. Furthermore, even if the meshing surfaces sl and St are approximately equal, the small torque transmitting portion 37 and the large torque transmitting portion 38
A similar effect can also be obtained by changing the diameter of the annular projection.

(Effects) According to the present invention, the large torque transmitting part and the small torque transmitting part of the fluid coupling are separated by the dynamic pressure generating part, and after the liquid from the liquid derivation mechanism is supplied and filled into the small torque transmitting part, the large torque transmitting part and the small torque transmitting part are separated. Since the torque is supplied to the transmission section, when the fan rotation speed is started up, the transmission torque can be gradually increased from a small torque by the small torque transmission section to obtain good startup characteristics.On the other hand, at maximum output, Large torque can be transmitted by both the large torque transmission section and the small torque transmission section, and sufficient fan driving force can be exerted.

[Brief explanation of the drawing]

1 to 6 are views showing an embodiment of the temperature-sensitive fluid fan coupling device according to the present invention, FIG. 1 is a side sectional view of the fan coupling device, and FIG. 3 is a partially enlarged sectional view of the fluid coupling, FIG. 4.5 is a view taken along the line IV-IV' in FIG. 3, and FIG. 6 is a view taken along the line IV-IV' in FIG. FIG. 7 is a partial cross-sectional view of a fluid coupling of a conventional temperature-sensitive fluid fan coupling device. 21... Fan casing, 21a... Front, 21c... Rear, 23... Partition plate, 24... Front chamber, 25 ... Rear chamber, 26 ... Liquid, 27 ... Temperature sensing element, 32 ... Liquid ejection mechanism, 33 ... Rotating shaft, 35... Fluid coupling, 36... Rotating plate, 37... Small torque transmission section 38... Large torque transmission section, 39... Dynamic pressure generation section, 45...Liquid introduction mechanism.

Claims (1)

[Claims] A fan casing having a front chamber and a rear chamber separated by a partition plate, a temperature sensing element attached to the front part of the fan casing and operating to sense temperature in response to the temperature of air received by the fan casing, and a temperature sensing element. The fan casing has a liquid extraction mechanism that operates in response to the temperature-sensing operation of the fan and can extract liquid from the front chamber to the rear chamber, a rotating shaft attached to the rear of the fan casing, and a rotating plate fixed to the rotating shaft. and a fluid coupling that transmits torque from the rotating shaft to the fan casing via the rotary plate and the liquid led into the rear chamber, and a fluid coupling that cooperates with the rotary plate of the fluid coupling to introduce the liquid in the rear chamber into the front chamber. A liquid introduction mechanism, the fluid coupling includes a small torque transmission section provided on one side of the rotary plate, a large torque transmission section provided on the other side of the rotary plate, and a large torque transmission section and the small torque transmission section. and a dynamic pressure generation section provided on the outer periphery of the rotary plate to separate the transmission section, and the liquid from the liquid derivation mechanism is supplied to the small torque transmission section, and after being filled, is supplied to the large torque transmission section. A temperature-sensitive fluid fan coupling device characterized in that: