JPH0159452B2 - - Google Patents

Description

DETAILED DESCRIPTION OF THE INVENTION Field of Industrial Application The present invention relates to a method of transmitting torque between relatively rotating input and output members using a fluid medium, which is used in a drive device for a cooling fan device of an internal combustion engine. Regarding fluid couplings.

Conventional technology Conventionally, a vehicle consists of a body member and a cover member.
an output member that forms a working fluid storage chamber and a working chamber; an input member that is located in the working chamber and forms a fluid shearing space between the output member and is rotatable relative to the output member; A fluid coupling has been proposed which increases or decreases the torque transmitted from the input member to the output member via the fluid by increasing or decreasing the amount of fluid in the working chamber, particularly in the shearing space.

In this type of fluid coupling, the storage chamber is located on the side surface of the working chamber, and communication holes with the storage chamber are opened at the inner and outer peripheries of the working chamber, respectively. Here, the communication hole closer to the inner circumference acts as a supply passage for fluid from the storage chamber to the working chamber, and the communication hole closer to the outer circumference acts as a discharge passage for fluid from the work chamber to the storage chamber. In addition, a pump section consisting of a protrusion extending from the output member toward one side end face of the input member is provided near the outer periphery of the work chamber in order to efficiently discharge the fluid in the work chamber. The fluid supplied to the chamber acts as a torque transmission medium between the input and output members within the working chamber, and then is directed toward the outer periphery of the working chamber by centrifugal force, and is stored via the pump section provided there. circulation to the chamber (Special Publication No. 40-28282,
54-91674, etc.).

Problems to be Solved by the Invention However, in the conventional fluid coupling described above, although the output member and the input member are provided with a protrusion serving as a pump portion that controls the pump action, this protrusion does not reach the input member in the working chamber. On the other hand, even if there is only one or two, the pump efficiency cannot be sufficiently improved due to the length structure. That is,
For example, if the protrusion is provided only on the cover member side, it can act as a pump on the fluid in the gap between the cover member and the input member, but the protrusion can act as a pump on the fluid in the gap between the cover member and the input member. Since the fluid in the gap does not act as a pump at all, shear resistance of the fluid occurs in the gap, making it impossible to sufficiently reduce the idle rotational speed of the output member. As a result, unnecessary horsepower is consumed to drive the output member.

On the other hand, when protrusions are provided on both the cover member and the body member, the fluid collides with both protrusions, increasing the pressure and obtaining a relatively good pumping action. Since the lengths are approximately the same, the fluid pressure that collided with one protrusion is not further increased by the other protrusion, but is returned to the storage chamber with the pressure given by one collision. Therefore, there is a problem that the pump efficiency cannot be sufficiently improved.

Means for Solving the Problems The present invention has been devised in view of the above-mentioned conventional problems, and in particular, protrusions extending into the working chamber are provided on both the body member and the cover member of the output member, and the body member The input member is characterized in that the protrusion provided on the cover member is set longer rearward in the rotational direction of the input member than the protrusion provided on the cover member.

Function As the input member rotates, the fluid in the working chamber collides with both protrusions and the pressure is increased, so it goes without saying that the entire fluid in the working chamber can be effectively returned to the storage chamber, and the body member The fluid whose pressure is increased by colliding with the protrusions on the side quickly flows toward the cover member and collides with the protrusions on the cover member side, further increasing the pressure, thereby further improving pump efficiency.

Embodiments Hereinafter, embodiments of the present invention will be described in detail based on the drawings.

FIG. 1 is a cross-sectional view showing an example in which the fluid coupling according to the present invention is applied as a drive device for a cooling fan device for an internal combustion engine, and 1 is an input shaft having a flange portion 2 and a shaft portion 3; It is fixed to the outer engine side, and an input member 4 is fixed to the tip of the shaft portion 3.

5 is a body member rotatably attached to the input shaft 1 via a bearing 6, and 7 is a cover member, which forms an annular chamber 8 between opposing inner surfaces, and whose outer periphery is secured by bolts 9... and are fixed to each other to form an output member. The annular chamber 8 is divided into a working chamber 12 by a partition plate 10 that is fixed to the cover member 7 and has left and right communication holes 10a, and a valve plate 11 that can cover and close the communication hole 10a. It is separated into a storage room 13. 14 is a communication hole provided in the cover member 7 and communicating the working chamber 12 and the storage chamber 13.

Reference numeral 15 denotes a spiral bimetal as a temperature-sensitive member, the outer peripheral end of which is fixed to the cover member 7, and the inner peripheral end of which is fixed to one end of a center pin 16 rotatably attached to the cover member 7. , the other end of the center pin 16 is fixed to the valve plate 11. Thus, the valve plate 11 rotates about the center pin 16 as the bimetal 15 operates in response to changes in ambient temperature, thereby opening and closing the communication hole 10a of the partition plate 10.

In the working chamber 12, the input member 4 is rotatably mounted, and the input member 4 has a through hole 17 near the center that communicates with the left and right sides. A plurality of annular grooves 4a and 5a are provided on each of the facing surfaces of the input member 4 and the body member 5, and a shearing space indicated by the symbol S is formed.

Further, the communication hole 1 provided in the cover member 7
4, near the opening end on the working chamber 12 side, there is a protrusion 2 in the direction of the working chamber 12, as shown in FIGS. 2 and 3.
0 is provided to form a pump section which will be described later. Further, a protrusion 19 extending toward the working chamber 12 and having a desired circumferential length is provided on the side surface of the body member 5 facing the peripheral edge of the input member 4 .
These protrusions 19 and 20 are arranged at positions substantially facing each other, and the protrusions 19 and 20 provided on the body member 5
9 is provided protrudingly facing the outer circumferential surface at the same time as one side of the input member 4, and the length of the protrusion 19 in the circumferential direction is
The length of the protrusion 20 on the cover member 7 in the circumferential direction is set to be longer at the rear in the rotational direction of the input member 4 .
Specifically, as shown in FIG. 2, a protrusion 19 provided on the body member 5, facing the protrusion 20 provided near the open end of the communication hole 14 of the cover member 7, is provided on one side of the input member 4 as well as on the outer circumferential surface. It is located protruding from above. Further, the circumferential length l ₂ of the protrusion 19 is longer than the circumferential length l ₁ of the protrusion 20, as shown in FIG. 20b are disposed at corresponding positions sandwiching the input member 4, so that the length _l2 of the protrusion 19 is longer than the length _l1 of the protrusion 20 in the rotational direction of the input member 4 (arrow X direction). At the rear, it is longer by l ₃ in this example. Further, on the outer periphery of the input member 4, an L-shaped radial protrusion 23 is formed at a desired height, and a groove 24 of a desired width is formed.
A plurality of grooves 24 are provided on the circumference, and the grooves 24 act as a passage connecting both the left and right sides of the input member 4. Further, the circumferential pitch P of the groove 24 is set shorter than the circumferential length l ₁ of the protrusion 20 provided on the cover member 7. By doing so, a decrease in pumping action due to fluid leakage is suppressed.

Note that 21 is a fan blade fixed to the body member 5 and the cover member 7, which are output members, with bolts 22.

In this configuration, the storage chamber 13 is filled with a desired amount of working fluid, and when the input member 4 is rotated via the input shaft 1 by an engine (not shown) and the ambient temperature near the bimetal 15 rises, the bimetal 15 responds to this, rotates the valve plate 11 via the center pin 16, and connects the communication hole 10 provided in the partition plate 10 by the valve plate 11.
The cover of a is gradually released and opened to allow the fluid in the storage chamber 13 to flow into the working chamber 12, thereby filling the shearing space S with the fluid. Here, the torque transmitted from the input member 4 to the output member body member 5 and cover member 7 is expressed as a function of the amount of fluid in the working chamber 12, particularly as a function of the amount of fluid in the shear space S. Therefore, the body member 5 which is the output member
and a fan blade 2 fixed to the cover member 7
1 increases the rotational speed as the fluid fills the shear space S and cools the engine. Subsequently, the fluid in the working chamber 12 is directed toward the outer circumference of the working chamber 12 by centrifugal force and flows into the pump section. Then, since the input member 4 is rotating in the direction of the arrow X shown in FIG. Each front end surface 19 of the protrusion 20
a, 20a, respectively, and the pressure is increased here. Therefore, the entire fluid within the working chamber 12 is effectively sent into the storage chamber 13 through the communication hole 14 by the pumping action. Moreover, the fluid in the gap between the body member 5 and the input member 4 collides with the front end surface 19a of the protrusion 19 provided on the body member 5, and the pressure is increased there, and then the fluid is inputted through the groove 24. The pressure flows from the right side to the left side of the member 4, and then collides with the front end surface 20a of the protrusion 20 provided on the cover member 7, thereby further increasing the pressure. In other words, the fluid is forcefully pushed into the groove 24 due to the high pressure generated in the first stage due to the collision at the front end surface 19a of the projection, and then quickly crosses the inside of the groove 24 to reach the front end surface 20a of the projection of the cover member 7 as it is. Since the pressure is further increased in the second stage by colliding with the liquid, the circulation effect returning to the storage chamber 13 via the communication hole 14 is greatly improved. In other words, the protrusion 19 on the body member 5 side
Since the length is set to be longer than the protrusion 20 of the cover member 7 in the rotational direction of the input member 4, the pumping efficiency for fluid is significantly improved compared to the conventional art.

On the other hand, when the ambient temperature near the bimetal 15 decreases, the bimetal 15 reacts to it, closes the communication hole 10a of the partition plate 10 by closing the valve plate 11, and cuts off the supply of fluid from the storage chamber 13 to the working chamber 12. . Therefore, the fluid in the working chamber 12 is stored in the storage chamber 13 by the pump action, the amount of fluid in the shearing space S is reduced, and the rotational speed difference between the input member 4 and the output members 5, 7 is reduced. The fan blade 21 rotates at idle. At this time, since the projections 19 and 20 efficiently send the fluid between the input member 4 and the output members 5 and 7 into the communication hole 14 while pushing out the fluid between the input member 4 and the output members 5 and 7, Substantially the entire amount of fluid can be stored in the storage chamber 13 without any remaining fluid in the gap, and therefore the idle rotational speed of the fan blade 21 is significantly reduced.

Further, the axial clearance between the input member 4 and the output members 5 and 7 is sufficiently wide except for the protruding parts of the protrusions 19 and 20, and the radial clearance is also wide except for the protrusion 19 parts, so that the output member 5 , 7 during idle rotation, even if fluid remains in the gap, the shear resistance caused by the residual fluid can be reduced and the idle rotation speed can be sufficiently lowered. Furthermore, the protrusion 23 provided on the outer periphery of the input member 4 is effective in scraping out the fluid passing through the groove 24 or the fluid existing in the radial gap between the input member 4 and the output members 5 and 7. , when the input member 4 rotates at a relatively low speed and the impact force of the fluid against each of the protrusions 19, 20 is reduced. Furthermore, the fluid that has collided with the front end 19a of the protrusion is forced into the cavity 27 defined by the protrusion 23, where the pressure is increased by the scraping action of the axial portion 23a of the protrusion 23. When flowing out from the groove 24 to the left side, the flow velocity becomes extremely high, and then it strongly collides with the protrusion front end 20a of the cover member 7. Therefore, this large collision force promotes the pumping action and efficiently returns the fluid in the working chamber 12 to the storage chamber 13, thereby allowing the output member 5,
7's idle rotation speed can be sufficiently lowered, thereby reducing the horsepower consumption.

According to a specific embodiment, the protrusion 23 of the input member 4
The height of the protrusion is about 1.5 mm, the width of the groove 24 is about 1.0 mm, and 30 pieces are provided on the circumference, the circumferential length l ₁ of the protrusion 20 of the cover member 7 is about 14 mm, and the protrusion 1 of the body member 5 is
9, the circumferential length _l2 is approximately 42 mm, the distance _l4 between opposing surfaces of each of the body member 5 or cover member 7 and the input member 4 is approximately 3.7 mm, _l5 is approximately 3.0 mm, each protrusion 19,
The axial clearance _l6 between 20 and input member 4 is approximately 0.75
mm, characteristics as shown by the solid line N in FIG. 6 were obtained. In other words, the conventional engine speed is
At 4000 rpm, the idle rotation speed of the fan blade, which is the output member, is approximately 920 rpm as shown by the broken line C.
However, in this example, the speed decreased to about 500 rpm. In addition, the horsepower consumption at this time was reduced from about 0.4 PS to about 0.1 PS.

Note that the protrusion provided on the outer periphery of the input member is not limited to an L-shape, and may simply be an axial protrusion, or may be an oblique protrusion as shown in FIG. 7 in order to efficiently flow the fluid in the axial direction. As the directional projection 25, a diagonal groove 26 may be provided.

Effects of the Invention As is clear from the above explanation, in the present invention, since both the body member and the cover member are provided with protrusions extending into the working chamber, as the input member rotates, the fluid in the entire working chamber is transferred to both protrusions. Of course, it is possible to effectively return the input member into the storage chamber by the pumping action of Because it is configured to be set for a long time,
The fluid in the working chamber can be efficiently circulated in the storage chamber by the stepwise pumping action of each of the projections. Therefore, when attempting to idle the output member, it is possible to quickly and reliably suppress fluid remaining in the working chamber. As a result, it is possible to sufficiently reduce the idle rotation speed,
Unnecessary horsepower consumption for driving the output member is reduced. As a result, it is possible to save energy and obtain a fluid coupling with extremely high performance.

[Brief explanation of drawings]

FIG. 1 is a sectional view showing an embodiment of the present invention as a driving device for a cooling fan device, FIG. 2 is an enlarged sectional view of the main part of FIG. 1, and FIG. 3 is a sectional view taken along the - line in FIG. Fig. 4 is a partially cutaway front view of the input member, Fig. 5 is a sectional view taken along the line V-V in Fig. 4, Fig. 6 is a rotational characteristic diagram of the fluid coupling, and Fig. 7 is another implementation of the input member. FIG. 3 is a perspective view of main parts showing an example. 4...Input member, 5...Body member (output member), 7...Cover member (output member), 12...Working chamber, 13...Storage chamber, 14...Communication hole, 19,
20...protrusion.

Claims (1)

[Claims] 1 consisting of a body member and a cover member, forming a working fluid storage chamber and a working chamber, an output member having a communication hole opening between the two chambers, and an output member located in the working chamber and rotating relative to the output member. In the fluid coupling, which includes a movable input member and transmits torque between the input and output members via fluid in the working chamber, the body member and the cover are located near the opening end of the communicating hole in the working chamber. A fluid fluid characterized in that both members are provided with protrusions extending into the working chamber, and the protrusions provided on the body member are set longer rearward in the rotational direction of the input member than the protrusions provided on the cover member. Fittings.