US3660626A

US3660626A - Sealed type current interrupting device

Info

Publication number: US3660626A
Application number: US13071A
Authority: US
Inventors: Seiichi Kawamura; Isamu Arano; Fumito Nakajima
Original assignee: Hitachi Ltd
Current assignee: Hitachi Ltd
Priority date: 1969-07-23
Filing date: 1970-02-20
Publication date: 1972-05-02
Anticipated expiration: 1989-05-02
Also published as: DE2009125A1; GB1275191A

Abstract

A sealed type current interrupting device for vehicles comprising electrode members for making and breaking current, a catalyst column containing a catalyst for decomposing ozone generated between said electrode members, and a casing member for sealing said electrode members and said catalyst column, whereby said electrode members and said catalyst column are substantially isolated from the outer atmosphere.

Description

0 United States Patent 1151 3,660,626 Kawamura et al. 1451 May 2, 1972 4] SEALED TYPE CURRENT [56] References Cited INTERRUPTING DEVICE UNITED STATES PATENTS Inventors: Seiichi Kawamura, Hitachi; sa u Ara 2,943,169 6/1960 Rice ..200/l68 G x Katsum; Fumim Nakflilmaa Hitachi all of 3,336,457 8/1967 Julian et al ....200/l68 0 Japan 3,348,0l3 10/1967 Waggoner ..200/19 R x [73] Assignee: Hitachi, Ltd., Tokyo, Japan [22] Filed: Feb. 20, 7 Primary E.\'am1 nerH. O. lones Attorney-Craig, Antonelll and H1" [21] Appl. No.: 13,071

, [57] ABSTRACT [30] Foreign Application Priority Dam A sealed type current interrupting device for vehicles com- July 23. 1969 Japan ..44/57690 pr ng l ro m m r r m ng and king r a catalyst column containing a catalyst for decomposing ozone [52] [1.8. CI ..200/l8 G, 200/19 R generated between said electrode members, and a casing [5 i [lit- Cl. member for ealing aid electrode members and aid catalys' [58] held of Search 200/1686, 19, 31 column, whereby Said electrode members and said catalyst column are substantially isolated from the outer atmosphere.

5 Claims, 7 Drawing Figures 1 B l-? ll1l iii) 8 l l6 ll 20 a 13 5 I15 PATENTEDMM 21912 3. 660.626

SHEET 5 [1F 5 INVENTORS SEIIcHI KAWAIWKRAI IsAMM ARANO d rumzro NAKA \TIMA @60 AQM M/ ATTORNEYS gines.

SEALED TYPE CURRENT INTERRUPTING DEVICE This invention relates 'to a sealed type electric current interrupting device for vehicles and, more particularly, to a distributor or a regulator for internal combustion engines, which is equipped in automobiles. I

A distributor for internal combustion engines, generally used in automobiles etc. comprises a current interrupting section, an angle-advancing mechanism section and a distributing section. A cap of the distributor thus constructed is provided with a central electrode for introducing a high voltage, and with a plurality of peripheral electrodes.

The introduced high voltage is distributed to the peripheral electrodes through a rotor electrode on a rotor thereby causing the plugsof the engine to spark. In this case, ozone (O is produced inside the distributing capdue to sparking caused by the distributing action. Particularly, ozone (O is remarkably strong in the oxidizing action, inducing the interior of the distributor to undergo rusting. Also, grease on the cam face of the cam shaft and/or lubricants on the individual parts have their rate of deterioration hastened, thus causing early wear to such parts. In addition, the ozone combines with nitrogen to form nitrogen oxides inside the cap, thereby bringing about such drawbacks as. leakage of a highvoltage caused between the rotor electrodeand-the peripheral electrodes disposed in thecap.

Therefore, various countermeasure have been taken in the prior art by providing ventilating means such as vent holes in the distributing cap or the'housing. Inthis case, however, dust and/or muddy water invade the interior of the distributor through the vent holes. Hence consideration shouldbe given to the position as well as the size of the vent holes dependent upon the mounting location of the distributor and the operating conditions of the vehicle. Accordingly, such countermeasures have made the design of the distributor very difficult and the manufacture of the same troublesome. In addition, although the vent holes .provide good results under some operating conditions, they sometimes become passages for the invasion of dust and/or muddy water thereby bringing about rusting of contacts inferior movement of the interrupter. Yet in addition, in casethe distributor isput in an atmosphere of gasoline onaccount ofany'd f ct in the fuel system, the vent holes provide passages for introducing the gasoline, whereby the introduced gasoline maybeinfiamed byarcs during distribution thus causing a. fire. Especially in vehicles wherein safety and reliability'areof prime importance, the above-mentioned facts shouldbe given sufficient consideration. Also, in other electric current interrupting devices for vehicles, such as regulators, relays, etc., rusting of parts and deterioration of lubricants and grease which will be caused by sparking, should be given sufficient consideration.

An object .of -thepresent invention is to provide a sealed type currentinterrupting device for vehicles which eliminates the undesirable, effect of ozone produced by sparking.

Another object of the present invention is ,to provide a sealed type current interrupting device provided with a catalyst for decomposing ozone whereby rusting of parts and deterioration of lubricants and grease may be sufficiently eliminated.

Further object of the present invention is to provide a cur- -rent interrupting device of the fireproof type which is completely isolated from the atmosphere thereby to avoide the invasion of dust, muddy-water and. gasoline into the inside of the. device.

Still further object of the present invention is to provide a fireproof type distributor suitable for internal combustion en- The accompanying drawings illustrate embodiments of distributors for internal combustion engines according to the presentinvention, in which: i I

FIG. 1 is a plan of a cap portion of the distributor;

FIG. 2 is a drawing of longitudinal local section of the dis- .tributor; 2

"FIG. 3 is an enlarged sectional view of a portion where a I catalystcase. is disposed;

FIG. 4 is a drawing of longitudinal local section of the distributor of another embodiment of the present invention;

FIG. 5 is a plan of an interruptor, which shows the installation of catalyst cases;

FIG. 6a is a perspective view of the main portion of a regulator for automobiles; and

FIG. 6b is a perspective view of a cover of the regulator shown in FIG. 6a.

In the embodiment shown in FIGS. 1 and 2, a housing 1 is integrally provided with a rotary-shaft supporting portion 2, and supports a rotary shaft 4 directly coupled with an engine, through bearing

members

3 and 3a. A cam shaft 5 is loosely fitted onto the rotary shaft 4. The cam shaft is equipped at the lower part thereof with a timing'lever 7 which is actuated in engagement with a governor weight 6. A rotor 9 which has a rotor electrode 8 is fixed at the upper end of cam shaft 5.

Numeral l0 designates a base which is fitted onto the inner peripheral surface of the housing being secured by means of screws 28. On the base 10 is slidably mounted a movable base 12 which is moved in response to the camshaft 5 which drives an interrupter l 1. The cam shaft Spenetrates through the base 10. A vacuum controller 13 is hermetically secured onto the outside of the housing l through a packing 14, and drives the movable base 12 through connecting means 15.

In the projections A and B of a distributor cap 16, a central electrode 17 and peripheral electrodes 18, l8a, 18b and 18c are embedded. The central electrode is kept in contact with the rotor electrode 8, and it is surrounded by

peripheral electrodes

18, 18a, 18b and 180. The distributing cap 16 is hermetically mounted on the housing 1 with a packing 19 interposed therebetween, and is fixed by means of a-clip 20. In this embodiment, an ozone decomposing catalyst 21 composed of, for example, Ag (silver) Al,0;, (alumina) is filled in the

respective catalyst cases

22, 22a, 22b and 22c which are respectively secured to the wall of the cap 16 or the housing 1 in the vicinity of the peripheral electrodes, and it is jointly used with a catalyst 24 in catalyst cases 23 disposed at the bottom part of the housing 1.

The catalyst cases 22,

22a

22b, 22c and 23 comprise, for instance, cylinders each being formed with a transparent synthetic resin. Each of these cases is press-fitted into a through hole 25 previouslybored in the housing 1 or the distributor cap 16. At the outer end of each case there is disposed a removable lid 26, while at the inner end there is laid a net 27, whereby gas permeabilityis maintained and simultaneously the

catalyst

21 or 24 is fully contained, within the cylinder. Also in this case, the state of the catalyst'may be observed through the catalyst case when it is made of a transparent material. Furthermore, as regards the attachment of the catalyst columns, the invention is not restricted to the foregoing embodiments, but it may also employ, for instance, the socalled capsule in which the catalyst is previously packed into a capsule case whose one end is made permeable to air through a net or the like and adapted to keep the catalyst in contact with only the air inside the'distributor. By employing such a capsule, the catalyst capsule is periodically changed in accordance with the running distance or period, and not only the assemblage of the catalyst case, but also the replacement of the same is facilitated.

Description will now be made of the operation of the device having the construction as outlined above. During driving of the engine, high voltage sparks pass between the rotor electrode 8 and the

peripheral electrodes

18, 18a, 18b and 18c, whereupon ozone (O is produced. The ozone (O is blown against the inner wall of the distributor cap 16 through a fan effect due to the rotation of the rotor 9, and is decomposed by the catalyst 21 packed in the

catalyst cases

22, 22a, 22b and 22c. With respect to ozone (0 which has not yet been decomposed, it is then decomposed by the second catalyst 24 disposed at the bottom of the housing 1, because ozone (O is the invention should not be restricted to the above description.

Referring now to FIGS. 4 and 5, an explanation will be given of further embodiments of the present invention. in the vicinity of the rotor electrode 8 and the

peripheral electrodes

18, 18a, 18b and 18c inside the distributor, cases 29 containing a catalyst'therein are secured by using, in common, mounting screws 28 for fixing the base 10. Thus, similar to the previous embodiment, ozone produced between the electrodes is absorbed and decomposed by the catalyst. The catalyst used here consists of an active ingredient and a carrier, and the active ingredient decomposes the ozone (0 thereby to prevent rusting and simultaneously prevent grease from being deteriorated, also it decomposes nitrogen oxides thereby to prevent deterioration in the insulation and leakage of the high voltage. The carrier of the latter component adsorbs the water contents to prevent rusting and disperses the active ingredient of the catalyst to increase the activity thereof.

Experiments by the inventors have revealed that for the ozone decomposing catalyst the most effective are; silver, activated carbon, copper oxide (CuO), manganesedioxide (M- n0 platinum, palladium, etc. Silver particularly exhibits the best decomposing property, and when air containing 1 to 2 ppm of ozone was brought into contact with silver dispersed in the porous alumina, the ozone could be decomposed to the extent that no more could be detected.

Such catalysts are practical when used by supporting them in any suitable carrier, and they should preferably be supported in such granules or pellets of alumina, silicious marl, etc. In the case of silvers, porous alumina granules are impregnated with a solution of silver nitrate, and then these granules are sintered to decompose the silver nitrate. Through the decomposition of silver nitrate, the silver catalyst is dispersed and supported in the form of a mixture of metallic silver and silver oxide. A catalyst consisting of silver and activated carbon in combination is obtained by impregnating a solution of silver nitrate into granular activated carbon and thereafter baking the solution-impregnated granules. In the case of copper oxide, copper nitrate and silicious marl are mixed together and kneaded with water. The kneaded mixture is molded into pellets or glanuls, and is then baked so as to obtain a copper oxide catalyst. In the case of manganese dioxide, potassium permanganate may be utilized. In an example of the present invention, copper oxide or manganese dioxide in powdery form and silicious marl were mixed together and kneaded, and the kneaded mixture obtained was formed into pellets, thus attaining the desired ozone decomposing catalyst. Silver demonstrated the most excellent effect in the decomposition of ozone. Accordingly, by using a combination of silver with the CuO catalyst or the CuO-Mn0 catalyst, better results may be expected. In the model experiment of the present invention, a catalyst with silver supported in alumina granules was supplied for the decomposition of ozone generated in the distributor. Even after a continuous running for one month, corrosion of any contacts or change in color of grease was barely noticeable. Based upon such facts as mentioned above, it has been experimentally verified that the present invention enables the distributor to be of the completely sealed type.

Furthermore, by employing a capsule containing the catalyst which is packed beforehand, the periodical replacement of the catalyst is facilitated, hence, it is possible for even a driver possessing relatively poor technical knowledge to perform the replacement in accordance with the running distance or period and without spending much time.

As described above, ozone (0,) generated in the distributor is absorbed and decomposed by the catalysts in the catalyst column disposed in the vicinity of the rotor electrode and at the lower portion of the distributor, so that rusting due to the presence of ozone (0 and/or the deterioration of the angleadvancing characteristic may be prevented. The deterioration of lubricants such as grease can be prevented, whereby all the mechanism is improved in endurability.

In addition, there is eliminated the necessity for the separate provision of vent holes, and simultaneously there will be no fear of the invasion of dust and/or muddy water through the vent holes as experienced in the prior art. Also, since a completely sealed construction can be employed, there is no invasion of liquid or vaporized gasoline into the interior of the distributor, hence, there is completely removed the fear of fire accident taking place, thus making the distributor excellent in safety and reliability.

As stated above, since, in accordance with the present invention, the completely sealed construction can be employed, the present invention is also applicable to other current interrupting devices in which troubles of the generation of ozone and the invasion of dust and muddy water should be paid attention to.

As an example, a regulator embodying the present invention is shown in FIG. 6a and 6b, in which a base 66 has a flat portion, legs 56 are provided with holes 58 for mounting it on a vehicle body. On the flat portion of the base, there are disposed a pair of electromagnetic relays 60 and a catalyst column 62 containing a catalyst therein. The catalyst column 62 is secured to the base through a frange 64.

A cover casing 50 shown in FIG. 6b is mounted on the base 66 by means of holes 52 provided in the flange portion 54 and holes 52a provided in the base 66 so as to isolate the air in th regulator from the atmosphere.

In such construction, ozone generated due to an interrupting operation between a movable contact 70 and. a stationary contact 72 is absorbed through small holes 68 provided in the catalyst column and sufficiently decomposed by the catalyst packed in the catalyst column, whereby both the undesirable effect of ozone and the invasion of dust and muddy water can be completely eliminated.

As well known, in the conventional current interrupting devices which are not of the sealed type from the consideration of ventilation, they have suffered from corrosion due to salt and moisture during the transportation thereof by ship. In accordance with the current interrupting device of the present invention, however, owing to its completed sealed construction, the above mentioned troubles can be completely removed. 7

What we claim is:

l. A sealed type current interrupting device comprising at least a pair of electrode member for making and breaking current in an atmosphere containing ozone generated by sparking between said electrode members, driving means for changing the relative distance between said electrode members to cause interruption, a casing member for sealing said electrode members, said driving means and said atmosphere therein, characterized in that said casing member is so constructed as to substantially isolate said atmosphere from the outer atmosphere, and a catalyst column containing a catalyst comprising porous alumina granules containing Ag distributed therein for decomposing ozone is disposed in said casing member.

2. In a current interrupting device having at least a pair of electrode means for making and breaking current in an atmosphere whereby a contaminant comprising ozone is generated by sparking between said electrode means the improvement comprising means, disposed adjacent said electrode means, for converting said contaminant generated by said sparking into a'substance non-contaminating to said electrode means, said converting means comprising a catalyst consisting of a material selected from the group consisting of silver, cupric oxide, manganese oxide platinum and palladium, which is chemically active with said ozone whereby said electrode means are protected from adverse effects of said contaminant.

3. A device according to claim 2, wherein said catalyst consists of silver.

4. In a current interrupting device having it least a pair of electrode means for making and breaking current in an atmosphere whereby a contaminant comprising ozone is generated by sparking between said electrodes means, the improvement comprising means disposed adjacent said electrode means, for converting said contaminant generated by said sparking into a substance non-contaminating to said electrode means said converting means comprising a catalyst consisting of a material selected from the group consisting of a mixture of silver and CuO and silver and CuO-MnO, which is chemically active with said ozone, whereby said electrode means are protected from adverse efiects of said contaminant.

5. In a current interrupting device having at least a pair of electrode means for making and breaking current in an atmosphere whereby a contaminant comprising ozone is generated by sparking between said electrode means, the im-' provement comprising means, disposed adjacent said electrode means, for converting said contaminant generated by said sparking into a substance non-contaminating to said electrode means, said converting means comprising a catalyst comprising porous aluminum granules containing silver distributed therein, which is chemically active with said ozone, whereby said electrode means are protected from adverse effects of said contaminant.

I! i l

Claims

1. A sealed type current interrupting device comprising at least a pair of electrode member for making and breaking current in an atmosphere containing ozone generated by sparking between said electrode members, driving means for changing the relative distance between said electrode members to cause interruption, a casing member for sealing said electrode members, said driving means and said atmosphere therein, characterized in that said casing member is so constructed as to substantially isolate said atmosphere from the outer atmosphere, and a catalyst column containing a catalyst comprising porous alumina granules containing Ag distributed therein for decomposing ozone is disposed in said casing member.

2. In a current interrupting device having at least a pair of electrode means for making and breaking current in an atmosphere whereby a contaminant comprising ozone is generated by sparking between said electrode means the improvement comprising means, disposed adjacent said electrode means, for converting said contaminant generated by said sparking into a substance non-contaminating to said electrode means, said converting means comprising a catalyst consisting of a material selected from the group consisting of silver, cupric oxide, manganese oxide , platinum and palladium, which is chemically active with said ozone , whereby said electrode means are protected from adverse effects of said contaminant.

3. A device according to claim 2, wherein said catalyst consists of silver.

4. In a current interrupting device having it least a pair of electrode means for making and breaking current in an atmosphere whereby a contaminant comprising ozone is generated by sparking between said electrodes means, the improvement comprising means disposed adjacent said electrode means, for converting said contaminant generated by said sparking into a substance non-contaminating to said electrode means , said converting means comprising a catalyst consisting of a material selected from the group consisting of a mixture of silver and CuO and silver and CuO-MnO2 , which is chemically active with said ozone, whereby said electrode means are protected from adverse effects of said contaminant.

5. In a current interrupting device having at least a pair of electrode means for making and breaking current in an atmosphere whereby a contaminant comprising ozone is generated by sparking between said electrode means, the improvement comprising means, disposed adjacent said electrode means, for converting said contaminant generated by said sparking into a substance non-contaminating to said electrode means, said converting means comprising a catalyst comprising porous aluminum granules containing silver distributed therein, which is chemically active with said ozone, whereby said electrode means are protected from adverse effects of said contaminant.