JPS6349093B2 - - Google Patents

Description

DETAILED DESCRIPTION OF THE INVENTION The present invention uses a fluid medium, a relatively rotating input,
The present invention relates to a type of fluid coupling that transmits torque between output members.

A fluid coupling of the above type is used, for example, for driving a cooling fan device of an internal combustion engine, and the ones shown in FIGS. 1 to 4 are known. To explain this, 1 is an input member, the input member 1 has a flange portion 2 and a shaft portion 3, and the flange portion 2 is fixed on the engine side (not shown). A bearing 4 and a driving member 5 are inserted into the shaft portion 3, and are integrally fixed to the shaft 3 by expanding the diameter of the tip 3a of the shaft portion 3. As shown in FIGS. 2 and 3, the drive member 5 has a substantially disk shape, and has a hole 6 for inserting the shaft portion 3 in the center, and radially outwardly spaced holes 6 at equal intervals in the circumferential direction. It has a plurality of communication holes 7 provided therein.
Further, a weir 8 is provided at one open end of the communication hole 7 along a part of the circumference of the communication hole 7 at the rear in the rotational direction (arrow) of the drive member 5 . Further, a plurality of annular grooves 9 are formed outside the communication hole 7, and a hole 10 is provided further outside the annular groove 9. On the other hand, 11 is a body member, and the body member 1
1 is rotatably attached to the shaft portion 3 of the input member 1 via a bearing 4, and a bolt 1 is attached to the outside thereof.
2 is integrally fixed to the cover member 13,
A working chamber 14 and a storage chamber 15 are formed between these chambers and accommodate the driving member 5 at intervals. In addition, the body member 11 has a plurality of annular grooves 16.
is formed, cooperating with the annular groove 9 of the drive member 5 in the working chamber 14 to interpose a shearing space designated by S. On the other hand, the cover member 13 is provided with a communication hole 17 that communicates the work chamber 14 and the storage chamber 15, and near the opening end of the communication hole 17 on the work chamber 14 side, there is a hole for carrying out work as shown in FIG. A protrusion 18 is formed in the direction of the chamber 14, and forms a pump portion 19, which will be described later, between the protrusion 18 and the side surface 5a of the drive member 5. Between the work chamber 14 and the storage chamber 15, there is a partition plate 21 having a communication hole 20 and fixed to the cover member 13, and a partition plate 21 located on the side of the storage chamber 15 that covers and closes the communication hole 20. Possible valve plate 2
2 are installed to separate the two chambers. Reference numeral 23 denotes a spiral bimetal as a temperature sensing device, the outer peripheral end of the bimetal 23 is fixed to the cover member 13, and the inner peripheral end is a center pin rotatably attached to the axial center hole 24 of the cover member 13. The center pin 25 is fixed to one end of the valve plate 25, and the other end of the center pin 25 is fixed to the valve plate 22. In addition, 26
is a fan blade fixed to the body member 11 and the cover member 13 as output members by bolts 27. In addition, the work room 14 and the storage room 15
is filled with the desired amount of working fluid.

In this configuration, the torque transmitted from the drive member 5 that rotates together with the input member 1 to the body member 11 and cover member 13 as output members is as follows.
It is expressed as a function of the amount of fluid in the working chamber 14, in particular as a function of the amount of fluid in the shearing space S mentioned above.
Therefore, when there is no fluid in the shear space S, the difference in rotational speed between the input member 1 and the output members 11, 13 is greatest, and as the amount of fluid increases, the difference decreases. becomes. Here, the valve plate 22 connected to the bimetal 23, which separates the working chamber 14 and the storage chamber 15 together with the partition plate 21, connects to the communication hole 20 of the partition plate 21 according to changes in the ambient temperature near the bimetal. cooperatively controlling the amount of fluid flowing into the working chamber 14;
It functions to control the torque and rotational speed difference transmitted between the input member 1 and the output members 11 and 13.
That is, as shown in FIG. 5, when the ambient temperature near the bimetal 23 increases, the bimetal 23 tends to contract, and the valve plate 22 is rotated counterclockwise from the position shown by the solid line via the center pin 25, and the valve plate The opening area of the communication hole 20 is increased by gradually removing the cover of the communication hole 20 provided in the partition plate 21 by the cover 22. As a result, the fluid in the storage chamber 15 flows into the working chamber 14, filling the shearing space S with fluid and reducing the rotational speed difference between the input member 1 and the output members 11, 13. At this time, the fluid flowing from the communication hole 20 of the partition plate 21 toward the working chamber 14 enters the gap 28 between the partition plate 21 and the drive member 5, and flows near the communication hole 7 of the drive member 5. By the weir 8 provided in the direction of reducing the gap 28 at the rear in the rotational direction,
The fluid in the gap 28 is collected and flows into the working chamber 14 through the communication hole 7. Next, work room 1
The fluid No. 4 is directed toward the outer periphery of the working chamber 14 by centrifugal force, reaches the side surface 5 a of the drive member 5 through the hole 10 , and flows into the pump section 19 . Then, as shown in FIG. 4, since the driving member 5 is rotating in the direction of the arrow, this fluid rotates along with the driving member 5 and collides with the right side surface of the protrusion 18 provided on the cover member 13. , where the pressure is increased, that is, under the action of a pump, to the storage chamber 15 through the communication hole 17.
Return to On the other hand, when the ambient temperature decreases, the valve plate 22 is moved to the fifth position by the action of the bimetal 23.
It is rotated clockwise from the position indicated by the two-dot chain line in the figure to cover and close the communication hole 20 of the partition plate 21, thereby cutting off the supply of fluid from the storage chamber 15 to the working chamber 14. Therefore, the fluid in the working chamber 14 remains stored in the storage chamber 15 due to the pump action, and since no fluid is present in the shearing space S, rotation between the input member 1 and the output members 11, 13 is prevented. This increases the speed difference.

By the way, in an internal combustion engine, as the rotational speed of the engine increases, the amount of heat generated also increases. Therefore, as described above, the fluid coupling that drives the cooling fan device operates to rotate it as quickly as possible. However, when an internal combustion engine is installed in an automobile, when the engine rotation speed is high, the vehicle speed is also high, i.e. when driving at high speed, and the engine is cooled by the amount of air received by the vehicle itself depending on the vehicle speed. I can do it. Therefore,
A fluid coupling used in a cooling fan drive device for an internal combustion engine for an automobile is desired to have a characteristic of reducing the rotational speed of the cooling fan device again when the engine rotational speed increases above a desired rotational speed.

However, in the conventional example, the partition plate 21
The communication hole 20 opens and the fluid that flows into the gap 28 is collected by the weir 8 provided in the drive member 5, and almost all of it is collected and enters the working chamber 14 from the communication hole 7.
In order to fully fill the shearing space, the fan plate 26 connected to the output members 11, 13
was to continue rotating at the fastest driven rotation speed.

The present invention has been made in view of the above-mentioned circumstances, and the inner diameter surface of the communication hole of the drive member is made into a tapered surface that widens toward the partition plate at least at the rear in the rotational direction of the drive member. In this case, the amount of fluid flowing into the working chamber is reduced, thereby reducing the driven rotational speed of the output member.Examples of the present invention will be described in detail below with reference to the drawings. In addition, the same reference numerals are attached to the same components as in the prior art, and redundant explanation thereof will be omitted.

FIG. 6 is a partially cutaway front view of the drive member 5 showing an embodiment of the present invention, and FIG. 7 is a sectional view taken along the line -- in FIG. In the figure, 7 is a communication hole, and the inner diameter surface of the communication hole 7 is in the rotational direction (arrow direction) of the drive member 5.
It has a tapered surface 7a that widens toward the partition plate 21 at the rear.

By configuring the drive member 5 in this way, when it is applied to the drive device of the cooling fan device shown in FIG. 1, the valve plate 22 is rotated by the action of the bimetal 23. When the communication hole 20 of the partition plate 21 opens and the fluid in the storage chamber 15 is guided to the gap 28 between the partition plate 21 and the drive member 5, when the drive member 5 is rotating at a relatively low speed. In this case, substantially the entire amount of the fluid that has flowed into the gap 28 flows into the working chamber 14 through the communication hole 7, and the shear space S formed between the drive member 5 and the body member 11 is filled by an appropriate amount. Accordingly, the body member 11 and the cover member 13 serving as output members are driven to rotate at a desired differential rotational speed with respect to the rotation of the drive member 5, that is, the input member 1. When the rotational speed of the drive member 5 further increases from this state, the fluid that has flowed into the gap 28 connects the communication hole 7 of the drive member 5 and attempts to flow into the working chamber 14. A force in the opposite direction to the inflow direction is applied by the surface 7a, and the inflow into the working chamber 14 is prevented. Then, the gap 2
The fluid in 8 passes between the driving member 5 and the cover member 13, reaches the pump section 19, and returns to the storage chamber 15 due to centrifugal force. Therefore, no fluid is supplied to said shear space S, which reduces the transmitted torque and increases the rotational speed difference between the input member 1 and the output members 11, 13. That is, the rotational speed of the fan plate 26 is reduced. Note that the rotational speed at which fluid is prevented from flowing into the working chamber 14 can be variously selected by changing the angle of the tapered surface 7a. Furthermore, the inner diameter surface of the communication hole 7 may be shaped like a truncated cone. Thus, input member 1
Above the desired rotational speed, the transmission of torque and rotational speed to the output members 11, 13 is reduced, reducing the consumption of engine power for driving the cooling fan device, and caused by the high speed rotation of the fan blades 26. Can prevent noise.

According to a specific example, the diameter of the communicating hole 7 is 14 mm.
When the tapered surface 7a with an angle of 30° was provided, the characteristics shown by the solid line A in FIG. 8 were obtained. In other words, the rotational speed of the fan blade is the same as the engine rotational speed.
It increases in proportion to the engine rotation speed up to about 2100 rpm, but gradually decreases after that, and when the engine rotation speed is about 3000 rpm, it decreases to about 1200 rpm. This rotation speed is equal to the engine rotation speed.
Equivalent to the rotation speed of about 1200 rpm. Also,
Conventionally, when the engine speed is 3000 rpm, the horsepower used to drive the fan blade is approximately 1.8 PS.
However, in this specific example, it was approximately 0.4 PS. In addition. A broken line B in the figure shows the characteristics obtained when the communication hole 7 has a conventional cylindrical inner diameter surface.

As explained above, according to the present invention, the drive member is fixed to the input member and has a communication hole communicating with the left and right sides, and the drive member is rotatably attached to the input member,
a body member that forms a shearing space with the driving member; and a cover member that is fixed to the body member and that forms a working chamber and a storage chamber that receive the driving member at a distance therebetween. and a partition plate located between the working chamber and the storage chamber to separate the two chambers and having a communication hole between the two chambers that can be selectively opened and closed, wherein Since the inner diameter surface of the hole is a tapered surface that widens toward the partition plate at least at the rear in the rotational direction of the drive member, when this is used to drive a cooling fan device of an internal combustion engine, the rotation speed is higher than the desired rotational speed of the engine. You can reduce the rotation speed of the cooling fan device. As a result, the horsepower consumption of the engine for the cooling fan device can be reduced, and the amount of fuel consumed accordingly can be reduced, and the generation of noise due to high-speed rotation of the fan blades can also be prevented.

[Brief explanation of drawings]

Fig. 1 is a sectional view showing a conventional fluid coupling as a drive device for a cooling fan device, Fig. 2 is a partially cutaway front view of the drive member of the conventional fluid coupling, and Fig. 3 is a line taken along the line shown in Fig. 2. Cross-sectional view, Figure 4 is the same as in Figure 1.
5 is a diagram illustrating the operation of the valve plate; FIG. 6 is a partially cutaway front view of a drive member showing an embodiment of the present invention; and FIG. 7 is a diagram illustrating the operation of the valve plate. FIG. 8A is a cross-sectional view of the main part of the driving member in the fluid coupling of the present invention,
FIG. 8B is a sectional view of a main part of a conventional drive member in comparison with this drive member, and FIG. 8C is a rotation characteristic diagram of each fluid coupling having these different drive members. DESCRIPTION OF SYMBOLS 1...Input member, 5...Drive member, 7...Communication hole, 7
a...Tapered surface, 11...Body member, 13...Cover member, 14...Working chamber, 15...Storage chamber, 20...Communication hole, 21...Partition plate, 22...Valve plate, S...
shear space.

Claims (1)

[Claims] 1. A drive member fixed to an input member and having a communication hole communicating with the left and right sides, a body member rotatably attached to the input member and forming a shearing space between the drive member, and this body member. a cover member which is fixed to the drive member and forms a working chamber and a storage chamber between which the driving member is received at a distance; In addition, in the fluid coupling having a partition plate having a communication hole between both chambers that can be selectively opened and closed, the inner diameter surface of the communication hole of the drive member is at least on the partition plate side at the rear in the rotational direction of the drive member. A fluid coupling characterized by having a tapered surface that widens in the direction.