JPS5850115Y2 - fluid coupling device - Google Patents

Description

[Detailed Description of the Invention] The present invention relates to a fluid coupling device, particularly a viscous fluid coupling device for driving an engine cooling fan of a vehicle or the like.

Conventionally, it has been desirable to increase the rotation speed of an engine cooling fan when the engine temperature is high, and to decrease the fan rotation speed when the engine temperature is low, in order to reduce engine power loss and noise. an input member having a rotating rotor thereon; an output member rotatably supported on the input member; a casing fluid-tightly fixed to the output member; and an input member formed by the output member and the casing. a partition plate forming a storage chamber for a viscous fluid and a working chamber for accommodating the rotor in a space; and a partition plate formed in the center of the partition plate to provide air communication between the storage chamber and the working chamber. an air communication hole; a first passage formed in the casing that communicates between the working chamber and the storage chamber; a pumping mechanism that sends viscous fluid from the working chamber to the storage chamber via the first passage; a second passage formed in a partition plate for communicating viscous fluid from the storage chamber to the working chamber; and a second passage driven by a temperature sensitive means to close the second passage when the temperature sensed by the temperature sensitive means is equal to or lower than a predetermined temperature. A fluid coupling device is proposed, comprising a valve means for opening the second passage when a sensed temperature is a predetermined temperature or higher, and transmitting torque from the rotor to the output member by the shear force of the viscous fluid in the working chamber. ing.

However, in the above type of conventional device, when the vehicle is in a stopped state, the viscous fluid in the operating chamber and the storage chamber are always communicated through a viscous fluid feed passage from the operating chamber to the storage chamber. Therefore, they are essentially at the same level.

When starting the next vehicle, even in low temperature conditions, enough viscous fluid remains in the operating chamber to transmit torque from the input member to the output member, so the cooling installed on the output member A so-called overshoot phenomenon occurs in which the fan rotates in a nearly direct connection state.

This results in inferior warm-up characteristics when the vehicle is idling, and is disadvantageous in that it increases the loss of transmitted torque.

Therefore, in view of the above-mentioned problems of the conventional device, the present invention aims to prevent the occurrence of the overshoot phenomenon.

In order to achieve this objective, the present invention provides a check valve in the air communication hole formed in the partition plate to allow only air communication from the storage chamber to the working chamber, and also includes a check valve formed in the casing. A one-way valve device is provided in the first passage to allow fluid communication from the working chamber to the storage chamber but block fluid communication in the opposite direction, and the one-way valve device is fixed to the casing. and a valve portion disposed on a partition plate inside the annular member, and the valve portion is configured to be held in the open position by fluid pressure from the operating chamber to the storage chamber. .

By adopting this configuration, when the vehicle stops with the viscous fluid in the working chamber being at a substantially minimum level, the introduction of viscous fluid from the storage chamber to the working chamber is prevented, that is, the overshoot phenomenon is prevented. It has achieved its intended purpose.

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

FIG. 1 shows a viscous fluid coupling device 10 according to the present invention.
Output member 13 and output member 1 rotatably supported on
It has a casing 14 that is fluid-tightly fixed to the casing 3.

A well-known fan assembly is secured to the casing 14 by suitable means.

The input member 11 holds a substantially disk-shaped rotor 15 that is fitted into one end thereof, and the opposing surfaces of the rotor 15 and the output member 13 are such that when the drive shaft 11 rotates, the rotor 15 is connected to the output member 13. A torque transmission surface 16 is formed.

A partition plate 17 whose outer periphery is fixed to the inner stepped shoulder of the casing 14 separates the inside of the output member 13 and the casing 14 into a working chamber 18 in which the rotor 15 is accommodated and a storage chamber 19 .

A viscous fluid, such as silicone oil, stored in the storage chamber 19 is returned to the working chamber 18 through a slot 20 provided in the partition plate 17, and when the drive shaft 110 rotates, the working chamber 18
Torque is transmitted from the drive shaft 11 to the output member 13 by the shear force of the viscous fluid inside.

The feeding of viscous fluid from the working chamber 18 to the storage chamber 19 is as follows:
This is done through a pumping element 21 disposed in the inner wall of the casing 14 and protruding toward the working chamber 18, and a passage 22 provided in the casing 14 so as to open to the circumferential walls of both chambers.

The amount of viscous fluid in the working chamber 18 is thus determined by the amount introduced via the slot 20 and the amount removed via the passage 22.

The outer periphery of the rotor 15 may be provided with notch means that cooperates with the pumping element 21 to perform a gear pumping function.

A temperature sensitive member, for example a disc-shaped bimetal 23, is held by a holder 24 fixed to the casing 14 so as to be able to rotate in response to temperature.

The bimetal 23 can come into contact with a rod 25 that extends through the casing 14 in a liquid-tight manner, and the other end of the rod 25 comes into contact with or is fixed to an arm-shaped valve member 26 .

The valve member 26 has one end fixed to the partition plate 17 and has a valve portion 27 at the other end that controls opening and closing of the slot 20.

The valve member 26 is always biased to the left by a spring 28 stretched between the valve member 26 and the partition plate 17, but when the bimetal 23 is in the position indicated by the solid line in the figure, it completely blocks the slot 20. .

When the bimetal 23 senses a temperature higher than a predetermined temperature and acts in reverse as shown by the dotted line in the figure, the valve member 26 is also displaced to the position shown by the dotted line, so that the valve part 27 is displaced laterally in the figure to open the slot 20. be.

A one-way valve 29, detailed in FIGS. 2 and 3, is disposed in the passage 22 described above.

The one-way valve 29 is an annular member 3 fixed to the casing 14.
The pumping element 21 has an umbrella shape 32 disposed on a partition plate provided on the inner peripheral surface of the annular member 30.
It may be provided above.

Thus, the valve portion 32 functions as a one-way valve that allows fluid communication from the working chamber 18 to the storage chamber 19, but blocks reverse flow.

A check valve 33, detailed in FIG. 4, is arranged on the partition plate 17.

The check valve 33 is provided in the partition plate 17 and is configured to control opening and closing of a center hole 34 that communicates air between the compartments 18 and 19.

The hole 34 acts as an escape hole for air as the viscous fluid is introduced into the storage chamber 19 (see the dotted line in Figure 4), but is configured to prevent communication of the viscous fluid between the compartments 18 and 19. .

The operation of the embodiment of the present invention constructed as described above is as follows.

When the drive shaft 11 is rotated by the engine via a power transmission means such as a pulley or belt (not shown), the rotor 15
Torque is transmitted to the output member 13 and the casing 14 by the shear force of the viscous fluid in the working chamber 18 caused by the rotation of the fan assembly, thereby rotating the fan assembly.

The transmitted torque is responsive to the shear force of the viscous fluid, ie, the amount of viscous fluid within the working chamber.

When the vehicle is operating particularly in cold conditions, in other words, when the vehicle is operating when the temperature sensed by the bimetal 23 is below a predetermined temperature, the valve portion 27 of the pulp member 26 controls the slit 20 to be shut off. The viscous fluid in the working chamber 18 is thus pumped into the storage chamber 19 via the gear pumping function described above and is reduced to a substantially minimum amount.

When the vehicle is stopped in this state, the valve portion 27 and the check valve 33 are in a position to cut off the communication of viscous fluid between the two chambers 18 and 19, and the one-way valve 29 is arranged in the passage 22 to store the viscous fluid. Viscous fluid communication from chamber 19 to working chamber 18 is blocked.

Therefore, when the vehicle is operated next time, the amount of viscous fluid in the working chamber 18 is kept to a substantially minimum level, and the fan rotation speed during cold conditions can be kept as low as possible.

FIG. 5 shows the fan rotation speed according to the above embodiment with respect to the engine rotation speed a.

The dotted line C in the same figure shows the fan rotation speed in a device in which the one-way valve 29 is not installed, and when the engine is stopped, viscous fluid flows from the storage chamber to the working chamber, and therefore it is difficult to operate the fan during the next operation. Excessive fan rotation occurs until the viscous fluid in the chamber reaches a substantial minimum.

When the bimetal 23 senses a temperature above a predetermined value, the valve portion 27 of the valve member 26 is actuated to separate the slot 20, thereby introducing viscous fluid from the storage chamber 19 into the working chamber 18 to rotate the fan assembly. This enables effective torque transmission.

FIG. 6 shows a modified embodiment of the one-way valve of the above-described embodiment of the present invention.

The one-way valve 29a is a normally closed valve portion 3 that is biased by a spring 32b to open and close a communication path provided in a member 30a.
Consisting of 2a.

The viscous fluid is fed from the working chamber to the storage chamber by the pressure of the fluid itself against the spring 32b.
This is done by opening up the

Therefore, the one-way valve 29a in FIG. 6 has the same function as the one-way valve 29 in FIGS. 2 and 3.

FIG. 7 shows a modified embodiment of FIG.
Components that are the same as in the figures are designated by the same reference numerals.

The bimetal 23a in this embodiment has a spiral shape, and one end thereof is fixed to the casing 14 via a holder 28a, and the other end is fixed to a rod 25a extending through the casing 14.

The other end of the rod 25a fixedly holds the valve member 26a.

In this configuration, the end portion of the bimetal 23a fixed to the rod 25a expands and contracts in response to temperature changes, and when a temperature above a predetermined value is detected, the rod 25a and the valve member 26a are moved as shown in FIG. When viewed from the left, the slot 20 is rotated clockwise to control opening and closing.

Other configurations and functions are the same as those of the embodiments in FIGS. 1 to 4,
Detailed explanation will be omitted.

Since the device of the present invention is constructed as described above,
Regardless of the driving situation of the vehicle, communication of viscous fluid from the storage chamber to the working chamber via the passage 22 can be prevented.

Therefore, especially when the vehicle is stopped with the viscous fluid in the working chamber at a substantial minimum, the introduction of viscous fluid from the storage chamber into the working chamber is prevented, thus preventing excessive fan rotation during the next low-temperature operation. This has the effect of preventing this and improving the idle link characteristics.

Moreover, since the passage for feeding the viscous fluid from the working chamber to the storage chamber has an opening in the peripheral side wall of the storage chamber,
The viscous fluid communicated from the working chamber to the storage chamber via the one-way valve is immediately uniformly distributed on the circumferential side wall of the storage chamber.

Therefore, the smooth flow of the viscous fluid from the storage chamber to the working chamber through the slot provided in the partition plate is not impaired.

[Brief explanation of drawings]

FIG. 1 is a sectional view of a fluid coupling device according to the present invention, FIG. 2 is an enlarged view of part A in FIG. 1 showing a one-way valve which is the main part of the present invention, and FIG. FIG. 4 is an enlarged sectional view of FIG. 1 showing a check valve, FIG. 5 is an operational characteristic diagram of the fluid coupling device shown in FIG. 1, FIG. 6 is a sectional view showing a modification of the one-way valve, and FIG. The figure is a sectional view showing a modification of FIG. 1. 10... Fluid coupling device, 11... Input member, 13... Output member, 14... Casing, 15... Rotor, 17・・・・・・
Partition plate, 18... Working chamber, 19... Storage chamber, 20... Slot, 22... Passage, 23... Bimetal, 26... Balf member, 27... Valve portion, 29... One-way valve, 30... Annular member, 31...
Partition plate, 32... Umbrella type, 33... Check valve, 34... Center hole.

Claims (1)

[Scope of utility model registration request] an input member driven by an engine and having a rotating rotor thereon; an output member rotatably supported on the input member; a casing fluid-tightly fixed to the output member; and the output member and the casing. a partition plate forming a storage chamber for a viscous fluid and a working chamber for accommodating the rotor in a space formed by the partition plate; an air communication hole that communicates with the casing, a first passage formed in the casing that communicates between the working chamber and the storage chamber, and a pumping mechanism that sends viscous fluid from the working chamber to the storage chamber through the first passage. a second passage formed in the partition plate for communicating viscous fluid from the storage chamber to the working chamber; and a second passage driven by a temperature sensitive means to close the second passage when the temperature sensed by the temperature sensitive means is equal to or lower than a predetermined temperature. valve means for opening the second passage when the sensed temperature is equal to or higher than a predetermined temperature;
In the fluid coupling device that transmits torque from the rotor to the output member by the shear force of viscous fluid in the working chamber, there is a reverse configuration in which only air communication from the storage chamber to the working chamber is allowed in the air communication hole. a stop valve is provided, and the first
A one-way valve device that allows fluid communication from the working chamber to the storage chamber but blocks fluid communication in the opposite direction is provided in the passage, and the one-way valve device includes an annular member that can be fixed to the casing; a valve portion disposed on a partition plate inside an annular member, the valve portion being held in an open position by fluid pressure of viscous fluid flowing from the working chamber to the storage chamber. Device.