JPH01176817A - Temperature sensitive type fluid fan coupling device - Google Patents

Abstract

PURPOSE:To aim at smoothly raising the rotational speed of a fan by forming a front chamber having such a shape that the ratio between a displacement of a liquid lead-out opening section and a liquid lead-out amount varies so as to decrease the liquid lead-out amount upon rise-up of the drive force of the fan. CONSTITUTION:A fan casing is sectioned by means of a partition plate 23 so as to define a front chamber 24 having the longitudinal width which increases radially outward and reserves therein liquid 26 having a predetermined viscosity, and a rear chamber 25. Further, a bimetal temperature element 27 drives a liquid lead-out mechanism 32 composed of a center shaft 28, a link 29 and a lead-out pipe 31 in association with a temperature of air passing therethrough so as to lead the liquid 26 from the front chamber 24 to the rear chamber 25. Further, a fluid coupling 35 transmits a torque from a rotary plate 38 fitted on a rotary shaft 33 to the fan casing 21. Accordingly, the liquid lead-out amount is controlled to a slight amount upon rise-up of the drive force of the fan, thereby it is possible to smoothly raise the rotational speed of the fan.

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-induced 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, the fan is installed between the radiator cooling fan of an automobile and the engine that drives the fan. 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 decreases during normal driving, the fan is prevented from rotating more than necessary to improve engine fuel efficiency, reduce fan noise, and shorten warm-up time.

A conventional temperature-sensitive fluid fan coupling device of this type is described in, for example, Japanese Utility Model Application Laid-Open No. 58-6996, as shown in FIG. In Fig. 5, a power transmission means 1 such as a repulley is driven by an engine not shown.
When the rotating shaft 2 is rotationally driven via the fluid coupling 3, the torque is transmitted from the rotating shaft 2 to the fan casing 4 via the liquid 5 in the fan casing 4, and the A fan (not shown) rotates. At this time, the liquid 5 in the front chamber 6 and rear chamber 7 of the fan casing 4 is urged radially outward of the fan casing 4 by centrifugal force, and remains in an annular shape. Further, the dam 9 engaged with the rotating plate 8 of the fluid coupling 3 wipes off the liquid 5 adhering to the outer peripheral surface 8a of the rotating plate 8, and introduces the liquid 5 into the front chamber 6 via the liquid passage 10. Therefore, the amount of liquid 5 in the rear chamber 7 is reduced and the amount of liquid 5 in the rear chamber 7 is reduced.
The transmitted torque becomes smaller and the fan rotation speed decreases. On the other hand, when the temperature of the air passing through the radiator received by the front part of the fan casing 4 increases, the temperature sensing element 11 deforms in response to the air temperature, and performs a temperature sensing operation to rotate the valve element 12. At this time, the valve hole 13a of the partition plate 13 and the valve body 12
Accordingly, an opening 14 for leading out the liquid according to the temperature sensing operation of the temperature sensing element 11 is formed, and the end portion 14a of the opening 14 moves from the radial inside of the fan casing 4 to the radial outside according to the temperature of the air passing through the radiator. I try to do that. And opening 1
The front chamber 6 stays radially inward from the end 14a of 4.
The liquid 5 inside is led out to the rear chamber 7 through the opening 14 and supplied to the fluid coupling 3. Therefore, when the temperature of the air passing through the radiator increases, the transmission torque of the fluid coupling 3 increases, and the fan rotation speed increases. That is, the fan rotation speed is adjusted according to the temperature of the air passing through the radiator, so that the fan does not rotate more than necessary.

(Problems to be Solved by the Invention) However, in such a conventional temperature-sensitive fluid fan coupling device, the end of the opening 14 formed by the valve seal 12 and the valve hole 13a of the partition plate 13 Part 14a
Since the configuration is such that the amount of liquid drawn out is uniquely determined by the displacement of the fan, the transmission torque of the fluid coupling 3 rapidly increases when the fan driving force is started up, and good start-up characteristics cannot be obtained.

That is, as shown in FIG. 6, even if the amount of liquid 5 led out from the front chamber 6 to the rear chamber 7 is small, the transmitted torque increases and the fan rotation speed suddenly rises. Therefore, if the amount of output is uniquely proportional to the displacement of the opening 14, the engine load required to drive the fan will increase rapidly, causing problems such as engine stalling during idling operation.

(Purpose of the Invention) Therefore, the present invention changes the ratio of the amount of liquid drawn out to the displacement of the liquid outlet opening by devising the shape of the front chamber, thereby reducing the amount of liquid drawn out when the fan driving force is started up. The purpose is to ensure good start-up characteristics.

(Means for Solving the Problem) In order to achieve the above object, the present invention provides a fan casing having a front chamber and a rear chamber separated by a partition plate, and a fan casing that is attached to the front part of the fan casing. is,
It has a temperature sensing element that operates in response to the temperature of the air received by the fan casing, and an opening that is displaced radially outward of the fan casing in response to the temperature sensing operation of the temperature sensing element. a liquid discharge mechanism capable of discharging liquid from the fan casing to the rear chamber; a rotating shaft attached to the rear of the fan casing; and a rotating plate fixed to the rotating shaft. a fluid coupling that transmits torque from a rotating shaft to a fan casing via a fluid coupling, and a fluid introduction mechanism that cooperates with a rotary plate of the fluid coupling to introduce liquid in a rear chamber into a front chamber, The chamber has an anteroposterior width that increases radially outward.

(Function) In the present invention, the fan casing is formed so that the front chamber has a longitudinal width that increases radially outward. Therefore, when the liquid is forced toward the radially outward side of the front chamber by the centrifugal force caused by the rotation of the fan casing, the amount of liquid that stays in the annular shape increases only in the radially outward direction. For this reason, when the fan driving force is started up with the liquid outlet opening located radially inward, the amount of liquid drawn out is small, and the transmission torque of the fluid coupling, that is, the fan driving force gradually increases from a small torque and starts smoothly. It can be raised.

(Example) Hereinafter, the present invention will be explained based on the drawings. 1 to 4 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 FIGS. 1 to 3, reference numeral 21 denotes 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. Further, the front chamber 24 is formed in a substantially circular shape, and the front chamber 24 has a small longitudinal width A0 on the radially inward side located within a predetermined radius r0 from the rotation center line, and has a small longitudinal width A0 located outside the predetermined radius r0. It has a longitudinal width Ax that increases in the radial direction on the radially outward side. That is, the front chamber 24 is formed into a chamber shape in which a radially inward small volume chamber and a radially outward annular large volume chamber are integrated (see FIG. 3).

27 is a temperature sensing body made of bimetal or the like;
It 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, the temperature sensing element 27 deforms in response to the temperature of the passing air from the radiator 22 received by the fan casing 21, and rotates the central shaft 28. It is designed to operate as a temperature sensor. The center shaft 28 passes through the front portion 21a of the fan casing 21 and is connected to a link 29 inside the front chamber 24, and the link 29 is guided out at one swinging end 29a that swings as the center shaft 28 rotates. It is rotatably connected to the tube 31.

The outlet pipe 31 has a smooth liquid outlet passage 31 with a substantially circular cross section.
The four outlet pipes 31 have an opening 31b at a radially outer end opening into the rear chamber 25 and an opening 31c at a radially inner end opening into the front chamber 24.

The opening 31b of the lead-out pipe 31 is rotatably connected to the radial 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 lead-out pipe 31 connects to the opening 31.
c is adapted to rotate in response to the temperature sensing operation of the temperature sensing element 27 so as to approach and separate from the inner circumferential wall 21b of the fan casing 21 (see FIG. 2). At this time, the liquid 26 in the front chamber 24 is urged toward the inner circumferential wall 21b of the fan casing 21 due to the centrifugal force caused by the rotation of the fan casing 21, which will be described later, and is retained in an annular shape. As a result, the opening 31c sinks into the liquid 26, and the liquid 26 can be led out from the front chamber 24 through the outlet pipe 31 to the rear chamber 25. That is, the central shaft 28, the link 29, and the outlet pipe 31 constitute a liquid outlet mechanism 32 that can guide the liquid 26 from the front chamber 24 to the rear chamber 25 through the opening 31c. It has an opening 3IC that is displaced radially outward of the fan casing 21 in response to the temperature sensing operation of the body 27. Note that when the liquid 26 in the front chamber 24 is urged radially outward and accumulates in an annular shape, the liquid level of the liquid 2G is transferred to the front chamber 24 by the liquid outlet mechanism 32.
It is adapted to be displaced radially inward and radially outward of the above-mentioned predetermined radius r0 according to the amount of liquid led out from the rear chamber 25 to the rear chamber 25, etc.

In addition, a rotation shaft 3 is provided at the rear part 2IC of the fan casing 21.
3 is rotatably attached, and the rotating 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 power transmission section 36 on the front side and a power transmission section 37 on the rear side. Power transmission section 36
．． Reference numeral 37 consists of a driving-side uneven portion having a plurality of coaxial annular protrusions and a driven-side mouth protruding portion formed to engage with the driving-side uneven portion with a slight gap, and the driving-side uneven portion is fixed to the rotating shaft 33. The rotating plate 38 is formed with the driven side uneven portion, and the driven side uneven portion is formed on the fan casing 21. The power transmission parts 36 and 37 are connected to the rear chamber 2 when the rotating shaft 33 rotates.
Rotating plate 3 due to fluid friction based on the viscosity of liquid 26 in 5
Torque is transmitted from the drive-side uneven portion of the fan casing 21 to the driven-side uneven portion of the fan casing 21. That is,
The fluid coupling 35 has a rotating plate 38 fixed to the rotating shaft 33, and transmits torque from the rotating shaft 33 to the fan casing 21 via the rotating plate 38 and the liquid 26 led out into the rear chamber 25. It is adapted to drive the fan casing 21.

On the other hand, a dam 41 is engaged with the outer peripheral portion 38a of the rotating plate 38, and the dam 41 is attached to the fan casing 21. The dam 41 comes into sliding contact with the outer circumferential portion 38a of the rotary plate 38 according to the sliding speed of the fan casing 21 and the rotary plate 38 when the fluid coupling 35 is operated, and wipes off the liquid 26 adhering to the rotary plate 38 and removes the liquid 26 from the fan casing 21. The liquid is introduced into the front chamber 24 through a liquid passage 42 formed in the front chamber 24. That is, the dam 41 and the liquid passage 42
constitutes a liquid introduction/mechanism 43 that cooperates with the rotary plate 38 of the fluid coupling 35 to introduce the liquid 26 in the rear chamber 25 into the front chamber 24, and the liquid 26 is introduced by the pumping action of the liquid introduction mechanism 43. Front chamber 24, liquid outlet mechanism 32
, the rear chamber 25 and the liquid introduction structure 43.

Note that 45 is a bearing such as a radial ball bearing, and the bearing 45 supports the rotating shaft 33 and also restricts the fan casing 21 and the rotating shaft 33 from moving in the axial direction when the fan is driven. . Also, 46.
47 is a seal ring, and the seal rings 46 and 47 are respectively attached to the fan casing 21 to maintain fluid turbulence in the front chamber 24 or the rear chamber 25.

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 point, the liquid 26 in the fan casing 21 is urged toward the inner circumferential wall 21b of the fan casing 21 by centrifugal force based on the rotation of the fan casing 21, and stays in an annular shape with the inner circumferential wall 21b as the bottom surface. At the same time, the dam 41 of the liquid introduction mechanism 43
The liquid 26 adhering to the outer circumferential portion 38H of the rotary plate 38 is wiped away, and then flows through the liquid passage 42 to the front chamber 24.
will be introduced in Therefore, the liquid 26 in the rear chamber 25 gradually becomes I! As a result, the effective power transmission area of the fluid coupling 35 gradually decreases, the sliding speed of the fluid coupling 35 increases, and the fan rotation speed decreases. During this time, the opening 31c of the outlet pipe 31 is located slightly above the level of the liquid 26 staying on the ring within the fan casing 21, that is, on the radially inward side of the fan casing 21.

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 opening 31 of the outlet pipe 3I
C sinks into the liquid 26 while approaching the inner circumferential wall 21b of the fan casing 21, and the liquid 26 staying inward from the opening 31c passes through the liquid introduction passage 31a and flows into the front chamber 24.
from there to the rear chamber 25. Therefore, when the temperature of the air passing through the radiator increases, the amount of liquid 26 in the rear chamber 25 increases, and the effective power transmission area of the fluid coupling 35 gradually increases.
Fan speed increases. That is, the fan rotation speed is adjusted in accordance with the temperature of the air passing through the radiator 22, which improves the fuel efficiency of the engine that is the driving source, shortens the warm-up time, and reduces fan noise.

Here, the rise characteristics of the fan rotation speed will be described, including the relationship between the displacement of the opening 31c of the outlet pipe 31 and the amount of the liquid 26 led out from the front chamber 24 to the rear chamber 25.

The opening 31c of the discharge pipe 31 before and after the discharge of the liquid 26
is located near the liquid level of the liquid 26, but this liquid level is located near the outlet pipe 3.
1 opening 31c is located on the inner peripheral wall 21 of the fan casing 21.
It is located radially inward from the predetermined radius r0 in a low temperature state (the state shown in FIG. 1) farthest from b. In addition, the thermosensor 27
When the opening 31c of the outlet pipe 31 is displaced radially outward so as to approach the inner circumferential wall 21b of the fan casing 21 in response to the temperature sensing operation, the liquid 2 flows into the rear chamber 25 through the opening 31.
6 is drawn out, and the liquid level in the front chamber 24 moves. At this time, since the front chamber 24 is formed in the shape of a small-volume chamber having a longitudinal width A0 radially inward, the amount of liquid 26 led out to the rear chamber 25 by the rotation of the outlet pipe 31 is minute. . Therefore, when the air temperature passing through the radiator becomes high and the fan driving force increases, the effective power transmission area of the fluid coupling 35 is gradually increased, and the fan rotation speed is smoothly increased.

Next, when the temperature of the air passing through the radiator becomes higher, the opening 31G of the outlet pipe 31 is opened in accordance with the temperature sensing operation of the temperature sensing element 27.
is further displaced radially outward by a predetermined radius r. reach further outwards. At this time, the opening 31c of the outlet pipe 31 reaches the annular large volume chamber of the front chamber 24, and as shown in FIG.
increases significantly compared to when the fan driving force is started up. Therefore, when the maximum output is required to cool the radiator 22, sufficient fan driving force is exerted.

In this way, in this embodiment, by increasing the longitudinal width of the front chamber 24 radially outward, the amount Q of liquid drawn into the rear chamber 25 is controlled to an appropriate amount in response to an increase in the air temperature passing through the radiator. Appropriate fan driving force corresponding to the increase in air temperature can be obtained.

For this reason, good start-up characteristics as shown by the fan rotation speed N in FIG. 4 are ensured. In addition, in Fig. 4, the broken line NAS
QA is the conventional fan rotation speed NA and introduced liquid amount QA shown for comparison, and it can be seen that the rise characteristic of the fan rotation speed in this example is significantly improved compared to the conventional one.

(Effect) According to the present invention, since the fan casing is formed so that the front chamber has a front-rear width that increases radially outward, the opening of the liquid introduction mechanism is located radially inward. When the fan is started up, the amount of liquid drawn out is controlled by a small amount, and the transmission torque of the fluid coupling is gradually increased from a small torque, allowing the fan rotation speed to be started up smoothly.

[Brief explanation of the drawing]

1 to 4 are diagrams showing an embodiment of the temperature-sensitive fluid fan coupling device according to the present invention, in which FIG. 1 is a side sectional view thereof, and FIG. 3 is a partial front sectional view showing the shape of the front chamber, FIG. 4 is a graph showing the rise characteristics of the fan rotation speed, and 5.
FIG. 6 is a diagram showing a conventional temperature-sensitive fluid fan coupling device, FIG. 5 is a side sectional view thereof, and FIG. 6 is a graph showing the relationship between the amount of liquid discharged and the fan rotation speed. 21...Fan casing, 21a...Front, 21C...Rear, 23...Partition plate, 24...Front chamber, 25 ...Rear chamber, 26...Liquid, 27...Temperature sensing element, 31...Outlet pipe. 31C...Opening, 32...Liquid delivery mechanism, 33...Rotating shaft, 35...Fluid coupling, 38...Rotating plate , 43...Liquid delivery mechanism, Ax...Front and rear width.

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 in response to the temperature of the air received by the fan casing, and a temperature sensing element a liquid discharge mechanism that has an opening that is displaced radially outward of the fan casing in response to a temperature-sensing operation and is capable of discharging liquid from the front chamber to the rear chamber through the opening; A fluid coupling includes a rotating shaft, a rotating plate fixed to the rotating shaft, and transmits torque from the rotating shaft to a fan casing via the rotating plate and a liquid led out to a rear chamber; and a fluid coupling that cooperates with the rotating plate of the fluid coupling. a liquid introduction mechanism that operates to introduce liquid in a rear chamber into a front chamber, and the front chamber of the fan casing has a front-rear width that increases radially outward. coupling device.