US3266471A

US3266471A - Automatic control apparatus for driving cooling fan of automobile engine

Info

Publication number: US3266471A
Application number: US311498A
Authority: US
Inventors: Masuura Kozo
Original assignee: Individual
Current assignee: Individual
Priority date: 1963-09-25
Filing date: 1963-09-25
Publication date: 1966-08-16
Anticipated expiration: 1983-08-16

Description

Aug. 16, 966 KOZO MASUURA 3,266,471

AUTOMATIC CONTROL APPARATUS FOR DRIVING COOLING FAN OF AUTOMOBILE ENGINE" Filed Sept. 25. 1965 2 Sheets-Sheet 1 IN VENTOR.

K Mh uuka BY 9111 63 m g- 1966 KOZO MASUURA 3,266,471

AUTOMATIC CONTROL APPARATUS FOR DRIVING COOLING 'FAN OF AUTOMOBILE ENGINE Filed Sept. 25. 1963 2 Sheets-Sheet 2 k Mnmqm INVENTOR.

United States Patent 3,266,471 AUTGMATIC CONTROL APPARATUS FOR DRIV- ING COOLING FAN OF AUTOMOBILE ENGINE Kozo Masuura, 58 Yawata Shimizu-mura, Sunto-gun, Shizuoka Prefecture, Japan Filed Sept. 25, 1-963, Ser. No. 311,498 1 Claim. (Cl. 12341.12)

This invention is concerned with providing a clutch mechanism for turning a fan, wherein a hollow tubular cavity 2 provided within a rotor shaft 1 of a Water pump along the axis of said shaft is divided into two parts, namely, a working shaft cavity 4 and a thermosensitive cavity 5 by means of reciprocating members 3 adapted for reciprocating in the direction of said axis, a thermo-sensitive chamber 7 is defined through contact of the circumferential wall of said thermo-sensitive cavity 5 with circulating water, said chamber being filled with a material 8 which is adaptable for changing the internal pressure therein according to temperature variations in said chamber, a spring is provided for reciprocating the working shaft 9 resiliently against the change in the' internal pressure, and said clutch mechanism for turning a fan is connected With the working shaft 9.

In the case that the material 8 to be filled in the thermosensitive chamber 7 provided in the apparatus of this invention is a liquid which is adaptable for changing the internal pressure through its evaporation and condensation, the quantity of the material should be such that both vapor and liquid phases can be kept at least until a predetermined pressure (a predetermined temperature) is reached, while use of such a material as wax, which can hardly be vaporized, makes it necessary to provide the working shaft 9 with the reciprocating movement of reciprocating members 3 through the spring 10'. For setting the Working temperature of the fan, the starting pressure of the working shaft 9 is restrained by restraining means 11, 11, 11" and 11" provided within the hollow tubular cavity formed in the rotor shaft and, when a predetermined pressure (a predetermined temperature) is reached, the restraint is removed so that the working shaft 9 is moved forward thereby the clutch is engaged. In turn, in order that the clutch will be auto: matically disengaged when the temperature of cooling water goes down to a predetermined value, means is adopted for regulating either the slope of a conical inner surface 13' adapted to be pressed by a clutch presscontacting surface 12 or the resiliency of the spring 10 or the both.

The characteristic features and advantages of this invention will be understood from the following description made with reference to the accompanying drawings, in which:

FIG. 1 is a longitudinal sectional view of an embodiment of this invention;

FIG. 2 is a sectional view taken along line II of FIG. 1;

FIG. 3 is a side view taken in section of the resilient member 20 in the portion indicated by A;

FIG. 4 is a longitudinal sectional view of another embodiment of this invention; and

FIG. 5 is a perspective view of a different form of a resilient member.

In the drawings, the like numerals indicate the like parts or the equivalents.

Referring to FIG. 1, a working shaft is restrained by means of restraining means provided within aworking shaft cavity 4, accordingly, a fan clutch is disengaged. 1 is a rotor shaft, 6 is the tube wall of a thermo-sensitive cavity 5, 8 is a material which is vaporized or condensed through change in its vapor tension according to the vari- 3,266,471 Patented August 1 6, 196.6

ations of Water temperature that may be sensed through the tube wall 6, 3 is reciprocating members adapted to divide the cavity 2 formed within the rotor shaft into the thermo-sensitive cavity 5 and the working-shaft cavity 4 respectively, 7 is a thermo-sensitive chamber confined by the reciprocating members 3, inner surface 14 of the cavity, and the tube wall 6 of the side cavity 5. The

reciprocating members 3 are provided by brazing at 15' the edges of bellows to the boundary of the cavities 4 and 5. 16 is a projection forming the head portion of the reciprocating

members

3, 9 is a working shaft, 10 is a spring for engaging the end of the

shaft

9, 1" is a communicating aperture adapted for communication between the inner and outer portions of the hollow shaft, 17 is a resilient clutch fixed to the working shaft 9, which resilient clutch is adapted to reciprocate in a communicating aperture 1", 12 is a clutch mounted to an arm end, 12 is a clutch press-contacting surface, 13 is a truncated cone-shaped fan boss made of synthetic resin, 13' is an iron plate embedded in the conical inner side surface of the boss, 13 is an iron plate embedded in the vertical outer side surface of the boss, 18 is an annular plate secured to the shaft end, 18' is a clutch press-contacting surface, 19 is an engaging portion of the fan boss, 1 is a retainer for preventing the engaging portion 19 from sliding laterally, 20 is a resilient member consisting of a solid butterfly spring as shown in FIGS. 2 and 3, or a resilient member consisting of wave-shaped annular spring shown in FIG. 5, 21 is a pump housing, 23 is a pump rotor, 24 is a Water intake port of the pump, 25 is a water exhausting port, 26 is a cover, 27 is ball bearings and 22 is an arm for transmitting the rotation of a pulley 22 to the rotor shaft.

FIG. 4 shows another embodiment of this invention in Which wax is employed; but the structure and operations thereof are similar to those illustrated in FIG. 1 except for reciprocating member and part associated therewith, therefore, description of the structure and operations are eliminated. In fact, a combination of a reciprocating member 3 (rubber plate), soft rubber 3, projection 16 and spring 10' serves to provide the same function as in the case of the reciprocating members. I

In accordance with this invention, the structure can be greatly simplified, the manufacture can be facilitated, and

pump without using a conventional rotor. Also, the state.

in which the clutch is half-engaged can be avoided, since the forward movement of the working shaft due to the change in the internal pressure of the thermo-sensitive chamber is restrained by the restraining means until the predetermined pressure (predetermined temperature) is reached, thus regulating the time when the cltuch is to be engaged.

On the other hand, the. time for the clutch to be disengaged will be set by the decrease in the internal pressure of the thermo-sensitive chamber and by the action of the spring 10 through pre-adjustment of the slope of the press-contacting surface and the resiliently pressed state which occurs in the slanting inner surface of the fan boss by the clutch surface when the clutch is engaged.

Since the resilient member has resiliency, it regulates the position where the fan boss is out of contact with 3,2eaa71 the clutch surface 18', thereby smoothing the separation of the clutch on the boss outer surface 13''. v The major part of the fan is made of synthetic resin, and thus its entire weight becomes smaller, accordingly, its revolutionary momentum becomes smaller as compared with the conventional fans made of metal. Furthermore, in order to improve the friction in the clutch press-contacting surface, embedding iron plates in the inner and outer,

side surfaces

13 and 13" of the boss made of synthetic resin may cause the revolutionary torque of the fan to be smooth. A substantially great pressing force is required in order to rotate the fan by means of presscontact of the clutch, however, satisfactory results could not be obtained simply by means of cubical expansion of the material according to variations in the temperature of cooling water. Either only expansive force of gas or cubical expansion of a material such as wax has been employed heretofore, however, power resulting from the former is insufficient and the latter is short of resiliency.

In accordance with this invention, a liquid capable of creating vapor tension, which affords suificient pressure to drive the fan when the temperature of cooling water goes up to such a degree that the fan should be driven, is hermetically filled within the thermo-sensitive chamber 7, and the quantity of the hermetically filled liquid is made as large as that required in order to normally maintain both vapor and liquid phases at least until the predetermined pressure (predetermined temperature of water) is reached, whereby a pressing state that changes independently of the variations in the working volume of the thermosensitive chamber but changes according to only variations in temperature can be obtained.

For carrying out this invention, a liquid having desired vapor tension should be selected first and then a quantity of the liquid larger than V.D. value is preferably .fi'lled, wherein V is the maximum working volume of the thermo-sensitive chamber and D is the saturated density of the vapor of the liquid employed at the temperature (water temperature) in the thermosensitive chamber 7 when the fan starts to be driven.

Materials having effective vapor tension are given in the following table by way of example.

DATA BY RAMSAY AND YOUNG Furthermore, in accordance with this invention, the spring is adapted to be actuated by taking out of the chamber the cubical expansive force resulting from expansion of a liquid hermetically filled within the chamber, the liquid which is not vaporized even when the temperature at which the fan should be driven is reached and which has a relatively large expansion coefiicient, including such a material having a relatively high liquifaction temperature as wax. In this case, wax, or the like may be effectively employed. I

The driving mechanism using temperature setting in accordance with this invention will now be described with reference to the embodiments illustrated in the drawings.

Example 1 (FIG. 1)

The rotor shaft 1, annular plate 18, and clutch 12 were normally combined with each other in operation, and

during operation of the engine they were normally kept rotating through the pulley 22 connected with the shaft 1. The drawing shows a manner in which the fan boss is disengaged since the clutch is disconnected.

At the temperature of cooling water of C., the gauge pressure required for driving the fan was 1 kg./cm. the V.D. value of the acetone employed being made approximately twice as large as the calculated value. The vapor tension of the liquid acetone within the thermosensitive chamber 7 increased according to the increases in the cooling water temperature, however, the actuation of the working shaft 9 had been restrained through adjustment of the restraining means 11, 11, 11" and 11 until the cooling water temperature reached 77 C., and the said shaft was adapted to move forward when the temperature would rise beyond 77 C.

An excess of the vapor pressure over the saturated vapor pressure approximately at 77 C. caused the ball 11 of the restraining means to be extracted from the recess 11 and thus the working shaft 9 moved forward resisting against the stress of the spring 10, while at the same time the

clutch surfaces

12 and 18 instantly pressed both the inner and outer side surfaces 13" and 13" therebetween. The temperature went up to 80 C., very soon, and then the clutch was completely engaged, whereby the fan was rotated at the same speed as that of the rotor shaft. By taking into consideration that frictional resistance would occur in the inner and outer side surfaces of the boss 13, the iron plates were embedded, thereby the press-contact of the clutch was greatly improved.

Decrease in the vapor tension of the acetone due to decrease in the cooling water temperature resulting from driving the fan caused the internal pressure within the thermo-sensitive chamber 7 to be decreased, thus reducing the pressing force of the working shaft 9, however, since the clutch was pressed into conically engaging relationship with the inner side of the boss by means of the arm 17, the press-contact surfaces remained resiliently press-contacted between the surfaces engaged into presscontact with each other, whereby the cooling water temperature gradually decreased while the clutch was engaged.

The time for the clutch remaining resiliently presscontacted to be disengaged was set so that the clutch would be disengaged when the cooling water temperature became approximately 70 C. (the gauge pressure became about 0.6 kg./cm. through adjustment of the resilient force of the spring 10 tending to return the spring to its original condition and the angle of the inner slanting surface of the fan boss. When the clutch was disengaged, the working shaft 9 was retracted due to the decrease in the internal pressure within the thermo-sensitive chamber and due to the resilient force of the spring 10 and thus it was returned to the original retaining position and retained thereat.

The above operations were repeated, and the cooling fan was driven andautomatically controlled.

Example 2 (FIG. 4)

FIG. 4 illustrates another embodiment of this invention, wherein only the illustrated part differs from the embodiment shown in FIG. 1 but the remainder thereof is similar to the embodiment shown in FIG. 1. Namely, wax was employed as-the thermo-sensitive material in the embodiment illustrated in FIG. 4, wherein the cubical expansion of the Wax deformed the spring 10' through the rubber plate 3 and soft rubber 3', thereby pressing the working shaft 9. Furthermore, the combination of the reciprocating members 3 and 3', projection 16, and spring 10' shown in FIG. 4 is adapted for performing the same function as the reciprocating members 3 and projection 16 shown in FIG. 1.

What I claim is:

An automatic control apparatus for driving the cooling fan of an automobile engine comprising, a rotor shaft, a water pump along the axis of said shaft, a working shaft cavity and a thermosensitive cavity formed along said shaft, a reciprocating member connected to said shaft at one end separating said cavities and serving as the Working wall of said thermosensitive cavity, said thermosensitive cavity having a circumferential Wall in contact with water circulated by said pump, said thermosensitive cavity acting as a confined chamber acting on said working wall; thermosensitive material hermetically placed in said confined chamber changing the internal pressure in said chamber according to temperature variations, longitudinally displacing said working wall and reciprocating member, spring means acting on said reciprocating member biased to maintain said working wall against said pressure, a clutch arm mounted on said shaft and a clutch with an outer engaging section mounted on the outer end of said clutch arm; a truncated shaped open cone boss including an inner engaging section disposed coaxially with said clutc'h, said clutch being inclined to enter and engage said cone, non-slip resilient means on said engaging sections, and, restraining means for restraining the References Cited by the Examiner UNITED STATES PATENTS 2,438,161 3/4948 Greenlee 123-4112 2,658,400 11/1953 Dodge 121341.12 2,879,755 3/1959 Weir 12341.l2 3,103,308 9/1963 Wolfram 123-4112 OTHER REFERENCES Vapor Pressure--Temperature Curves, published by Clifford Mfg. Co., Boston, Mass, 1940.

LAURENCE v. EFNER, Primary Examiner.