JPH053661U - Fluid fitting - Google Patents

Abstract

(57) [Summary] [Purpose] To prevent accompanying rotation of the driven member due to residual working fluid in the labyrinth groove without causing power loss. [Structure] A protrusion 7A provided on the disk 7 on the drive shaft 1 side
And the projection 13A provided on the cover portion 13 of the housing 3 form a labyrinth groove located in the working chamber 9, and the slit 7C is provided at the base end portion of the projection 7A.

Description

[Detailed description of the device]

[0001]

[Industrial applications]

 The present invention relates to a fluid coupling, and particularly to a fluid coupling suitable for use in a fan coupling device for driving a cooling fan of an internal combustion engine for automobiles.

[0002]

[Prior Art]

 Conventionally, as this type of fluid coupling, for example, one described in Japanese Utility Model Publication No. 59-39218 is known.

In such a fluid coupling, a pair of ridges forming a labyrinth groove is provided at a portion of the fan drive shaft (driving member) side located in the working chamber facing the coupling housing (driven member). A working fluid storage chamber is connected to the working chamber through an inflow passage and a return passage that can be controlled to open and close, and an oil scraping element that partially narrows the labyrinth groove is further provided on the pair of protrusions. It is provided.

Then, by controlling the opening and closing of the inflow passage according to the air temperature after passing through the radiator, the inflow amount of the working fluid from the storage chamber to the working chamber is adjusted, and the torque transmitted from the rotor to the coupling housing is adjusted. The working fluid in the working chamber is returned to the storage chamber through the return passage. Further, the oil scraping element scrapes off the working fluid remaining in the labyrinth groove at the time of starting the engine in which the inflow passage is closed, etc., so that the torque transmission is almost completely shut off. In other words, this oil scraping element prevents the torque from being transmitted unnecessarily by the working fluid remaining in the labyrinth groove, and the rotation of the coupling housing due to the unnecessary torque transmission is called rotation. As a result, the warm-up characteristics are deteriorated when the engine is started.

[0005]

[Problems to be solved by the device]

 However, the oil scraping element partially narrows the labyrinth groove, which increases the frictional resistance, resulting in loss of horsepower of the engine. There is a problem that the flow resistance of the working fluid remaining in the groove increases, and the coupling housing is rotated together. Moreover, since the oil scraping element must be attached to the ridge forming the labyrinth groove, there is a problem that the structure becomes complicated and the manufacturing process becomes complicated.

An object of the present invention is to reliably prevent entrainment of a driven member due to residual working fluid in a labyrinth groove without causing power loss, and to provide a fluid with a simple structure. To provide a joint.

[0007]

[Means for Solving the Problems]

 The fluid coupling of the present invention is provided with a pair of protrusions located in the working chamber of the working fluid to form a labyrinth groove, at a position where the driving member and the driven member arranged so as to be rotatable relative to each other are disposed. In the fluid coupling in which the working fluid storage chamber communicates with the working fluid supply passage and the return passage whose opening / closing can be controlled, a slit is formed in at least one base end portion of the pair of protrusions. Is characterized by.

[0008]

[Action]

 The fluid coupling of the present invention can be driven by providing a slit at the base end portion of at least one of the pair of protrusions on the driving member side and the driven member side that form the labyrinth groove in the working chamber. When the rotation of the member is started, the working fluid remaining in the working chamber is quickly discharged to the outside of the labyrinth groove by the centrifugal force through the slit.

As a result, it is possible to surely prevent the follower member from rotating around due to the residual working fluid in the labyrinth groove without causing power loss. For example, the fluid coupling of the present invention can be used for a fan coupling of an automobile. When used as, the engine does not lose the horsepower of the engine and improves the warm-up characteristics when the engine is started.

Further, since it is only necessary to provide a slit in the protrusion forming the labyrinth groove, it is possible to simplify the structure.

[0011]

【Example】

 Hereinafter, an embodiment of the present invention will be described in detail with reference to the drawings. The present embodiment is an application example as a fan coupling of an automobile.

In the figure, 1 is a drive shaft that is a drive member having a flange to which a V belt pulley or the like is attached, and 3 is rotatably supported by the drive shaft 1 via a bearing 5, and a cooling fan is attached to the outer periphery thereof. A driven member housing, 7 is a disk fixed to the front end of the drive shaft 1 and housed in a working chamber 9 described later in the housing 3. The housing 3 includes a body portion 11 that is directly supported by the bearing 5, and a cover portion 13 that is connected to the front end of the body portion 11 by crimping. The inside of the housing 3 is a storage chamber 17 on the front side by a partition plate 15. It is separated from the working chamber 9 on the rear side.

A plurality of annular projections 7A and 13A meshing with each other with a predetermined gap are formed in the vicinity of the outer peripheral end of the disk 7 and the inner end wall of the cover 13, respectively. The labyrinth groove is configured with to obtain the viscous resistance of the working fluid such as silicone oil and to act as a fluid coupling.

The annular projection 7A on the disk 7 side is radially notched at four locations 7B at 90 ° intervals along the circumferential direction of the disk 7, and the operation is performed by centrifugal force passing through the notched locations 7B. The fluid is adapted to flow to the outer peripheral end side of the disk 7. Further, a plurality of slits 7C are formed at the base end portion of the annular protrusion 7A, that is, at the joint portion with the disk 7. In the case of this example, slits 7C are formed at eight locations at 45 ° intervals along the circumferential direction of the disk 7. These slits 7C are formed by a processing method such as cutting. Further, the disk 7 is provided with circular holes 7D at six positions at intervals of 60 ° along the circumferential direction.

On the other hand, the cover portion 13 is provided with a bent supply passage 19 and a return passage 21 that communicate the storage chamber 17 and the working chamber 9, and the latter return passage 21 is opened on the working chamber 9 side. A protrusion 23 is provided on one end in the circumferential direction. The projection 23 constitutes a pump mechanism with the side end surface of the disk 7.

Further, the partition plate 15 is formed with first, second and third communication holes 24, 25 and 26 for communicating the storage chamber 17 with the working chamber 9. Further, the insides of the storage chamber 17 and the working chamber 9 are partitioned by a sub plate 41 and a plug plate 42. The sub-plate 41 connects the supply passage 19 and the third communication hole 26, and connects the return passage 21 to the first and second communication holes 24 and 25 via the storage chamber 17, The inside of the storage chamber 17 is partitioned. On the other hand, the plug plate 42 is attached to the partition plate 15 so that the second and third communication holes 25 and 26 communicate with each other. Thereby, as a passage for the working fluid in the storage chamber 17 to flow into the working chamber 9, the first passage passing through the first communicating hole 24, the second and third communicating passages 25, 26 and the supply A second passage through the passage 19 is formed.

A rotary shaft 29, in which the central end of the outer spiral bimetal 27 is fixed, is borne in the substantial center of the cover portion 13, and the inner end of the rotary shaft 29 has the above-mentioned first portion. A valve plate 31 that opens and closes the second communication holes 24 and 25 is supported. The outer peripheral end of the spiral bimetal 27 is fixed at a fixed position of the cover portion 13, detects the temperature of the air passing through a radiator (not shown), and rotates the rotating shaft 29 together with the valve plate 31 in accordance with the temperature. It is designed to move.

Next, the operation will be described.

First, when the atmospheric temperature near the bimetal 27 is low immediately after the engine is started, that is, immediately after the rotation of the drive shaft 1 driven by the engine is started, the valve plate 31 is operated by the action of the bimetal 27. The first and second communication holes 24 and 25 are closed to substantially stop the circulation of the working fluid. At that time, the working fluid remaining in the labyrinth groove flows to the outside of the disk 7 through the slit 7C by the centrifugal force and is sent out into the storage chamber 17 through the return passage 21 by the above-mentioned pump mechanism. .. As a result, the working fluid remaining in the labyrinth groove is quickly discharged at the same time as the engine is started, and the housing 3 is no longer accompanied by the remaining working fluid, and the housing 3 is no longer needed. It does not rotate at high speed, but rotates at low speed with the cooling fan. Therefore, the warm-up characteristic at the time of starting the engine is improved.

Next, when the atmospheric temperature near the bimetal 27 rises, the valve plate 31 gradually opens the first and second communication holes 24 and 25, and the working fluid in the storage chamber 17 is opened by the communication hole 25. Will flow into the working chamber 9. Then, a drive torque corresponding to this inflow amount is generated, and the housing 3, and thus the cooling fan, rotate at high speed. At that time, the working fluid supplied to the labyrinth groove is guided by the centrifugal force into the labyrinth groove on the outer peripheral side of the disk 7 through the slit 7C. Since the labyrinth groove located on the outer peripheral side of the disk 7 efficiently transmits the torque, the rotation speed of the housing 3 and eventually the cooling fan is sufficiently increased, and the cooling efficiency of the engine is improved. ..

The height H of the slit 7C (see FIG. 4), the length, the shape, the number of the slits 7C, and the like are appropriately changed according to various conditions. For example, it is preferable that the total length of the plurality of slits 7C in the entire circumference of the annular projection 7A be about 1/4 to 1/2 of the entire circumference of the annular projection 7A. The slit 7C may be provided on the annular projection 13A side of the cover 13 together with the annular projection 7A side or instead of the annular projection 7A side.

[0022]

[Effect of the device]

 As described above, in the fluid coupling of the present invention, at least one of the pair of projections on the driving member side and the driven member side forming the labyrinth groove in the working chamber has a slit at the base end portion of the projection. Since the structure is provided, the working fluid remaining in the working chamber can be promptly discharged to the outside of the labyrinth groove through the slit by the centrifugal force when the rotation of the drive member is started.

As a result, it is possible to reliably prevent accompanying rotation of the driven member caused by the residual working fluid in the labyrinth groove without causing power loss. Therefore, for example, when the fluid coupling of the present invention is used as a fan coupling of an automobile, it is possible to improve the warm air characteristic at the time of starting the engine without causing a loss of horsepower of the engine.

Moreover, the structure is simple because it is only necessary to provide slits in the protrusions that form the labyrinth groove.

[Brief description of drawings]

FIG. 1 is a sectional view showing an embodiment of the present invention.

2 is a plan view of the disc shown in FIG. 1. FIG.

FIG. 3 is a sectional view taken along the line III-III in FIG.

FIG. 4 is a sectional view taken along line IV-IV in FIG.

[Explanation of symbols]

 1 Drive Shaft (Drive Member) 3 Housing (Following Member) 7 Disk 7A Annular Protrusion 7C Slit 9 Working Chamber 11 Body Part 13 Cover Part 13A Annular Protrusion 17 Storage Chamber 19 Supply Passage 21 Return Passage

Claims (1)

[Claims for utility model registration] Claims: 1. A pair of projections that form a labyrinth groove located in the working chamber of the working fluid are provided at the facing portions of the driving member and the driven member that are arranged so as to be rotatable relative to each other. In a fluid coupling provided with the working chamber, the working fluid storage chamber communicating with the working fluid supply passage and the return passage, the opening and closing of which can be controlled, in at least one base end portion of the pair of protrusions. A fluid coupling characterized in that a slit is formed.