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Publication numberUS3849850 A
Publication typeGrant
Publication dateNov 26, 1974
Filing dateSep 20, 1973
Priority dateSep 22, 1972
Also published asDE2340068A1
Publication numberUS 3849850 A, US 3849850A, US-A-3849850, US3849850 A, US3849850A
InventorsGoutard R
Original AssigneeAutomatisme & Technique
Export CitationBiBTeX, EndNote, RefMan
External Links: USPTO, USPTO Assignment, Espacenet
System for automated production of spark plugs
US 3849850 A
Abstract
A system for automated production of spark plugs, which comprises a first station for the production of insulators, a second station for the assembly of the central component of the spark plug, and a final assembly station; each station operates, at least partially, in continuous kinematic motion, and the transfer means between the stations comprises storage means. The system also comprises means for servo-control and synchronization of the stations, the parts, before their final assembly, being transferred in vehicles belonging to each station or part of a station.
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Description  (OCR text may contain errors)

United States Patent 1 Goutard [4 1 Nov. 26, 1974 SYSTEM FOR AUTOMATED PRODUCTION OF SPARK PLUGS [75] Inventor: Rene Michel Goutard, Verrieres Le Buisson, France [73] Assignee: Automatisme & Technique, Arcueil (Val de Marne), France [22] Filed: Sept, 20, 1973 [2]] Appl. No.: 398,927 no] Foreign Application Priority Data Sept.22 1972 France ..72.33739 [52] U.S. Cl 29/25.19, 29/200 A, 29/430 [51] Int. Cl. H0lj 9/48 [58] Field of Search 29/25.l9, 25.2, 25.12,

29/429, 430, 200 A, 203 D, 208 D; 198/19 [56] References Cited UNITED STATES PATENTS Christie et al. 29 25.19

Primary ExaminerRoy Lake Assistant ExaminerJames W. Davie Attorney, Agent, or FirmKinzer, Plyer, Dorn & McEachran [5 7] ABSTRACT A system for automated production of spark plugs, which comprises a first station for the production of insulators, a second station for the assembly of the central component of the spark plug, and a final assembly station; each station operates, at least partially, in continuous kinematic motion, and the transfer means betweenthe stations comprises storage means, The system also comprises means for servo-control and synchronization of the stations, the parts, before their final assembly, being transferred in vehicles belonging to each station or part of a station.

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SYSTEM FOR AUTOMATED PRODUCTION or SPARK PLUGS The present invention relates to a system for the automated production of spark plugs for internal combustion engines.

Present systems for mass production of spark plugs require a number of machines operating on a batch basis. Each machine produces or assembles the constituent parts of a spark plug; usually, a sub-assembly of part is. first produced, then stored, and subsequently brought to another machine where additional operations are carried out, also on a batch basis. These systems, of very varied types, all have the disadvantage of giving relatively low production rates, being complicated, and requiring a relatively large amount of labor, as there are many handling operations between the machining and assembly machines.

for automated production of spark plugs at a high rate,

which can be adapted to the production of a wide variety of types of spark plug by simple additions to or modifications of the constituent parts.

To this end, the invention relates to a system for the automated production of spark plugs, characterised in that it comprises a first station for the production of insulators, a second station for the assembly of the central component of the spark plug, and a final assembly station, each station operating at least partially in continuous kinematic motion. The transfer means between the stations comprises storage means; the system also comprises means for servo-control and synchronization of the stations, the parts, before their final assembly,

being transferred in vehicles belonging to each station or part of station.

- Under the invention, the system for automated production of spark plugs combines the advantages of a series of production stations operating in continuous motion, at a high production rate, with the avoidance of the disadvantages of a too rigid and complicated construction, by virtue of the transfer means between the stations. This transfer means comprises storage and synchronization means, allowing compensation for changes in the relative operating rates of the stations without interrupting operation of the overall system.

is very much longer than that of the operations that precede it, the insulators are passed in parallel lines through several curing tunnels in order to obtain a sufficient output rate. Moreover, because the sintering machine in separate, special vehicles especially suited to heat treatment can be used in it; these vehicles are not necessarily identical with the vehicles used in the compacting and machining apparatus.

The completed insulators are transferred to a central component assembly station, in which the internal conductive components are assembled in each insulator and cemented in place. At the next and final station, the conductive holder is mounted on each central component, together with any required mounted gaskets and the like, finishing the complete spark plug manufacturing operation. The transport between the operating station allows for some differential in production rates without requiring system shutdown.

The system of .the invention, some principal characteristics of which are enumerated above, produces spark plugs automatically at a high rate, but is not limited to any one type of spark plug, and can be adapted to different types very simply by changing or moving a The system of the invention starts with a rotary insulator compacting mechanism, which produces a series of dense, compacted insulator blanks. These insulator blanks are transferred to an insulator machining drum that includes a mill. The forward machining speed of the mill is adjusted uniformly or proportionally to the mass of the matter removed, by means of a cam also used to compensate for wear of the mill. The machining drum is enclosed so that dust and other machining byproducts are controlled and contained. These byproducts are recovered for use in the fabrication of new blanks, for which purpose they can be returned to the hopper ofthe initial compacting drum. The mill of the machining drum can be dismantled rapidly to allow for effective maintenance operations conducted outside the machine.

The system utilizes a sintering machine which is separate from the compacting and machining apparatus; consequently, heat from the sintering machine does not adversely affect the compacting and machining operations. Because the duration of the sintering operation working unit or a working drum. Since the parts, and particularly the insulators, are transported in vehicles, they are not subjected to wear or shock, which considerably reduces the number of plugs that are rejected. Another advantage of this method resides in the fact that since the insulator is not subjected to wear, there is no formation of abrasive dusts, which can cause rapid wear of the components of the machines and the systern.

The present system will be described in greater detail with the aid of one embodiment of the invention, represented schematically, by way of non-limitative example, in the accompanying drawings in which:

FIG. 1 is a detailed view of a conventional spark plug, which can be produced by a system constructed in accordance with the invention;

FIG. 2 is a detailed elevational view of the central component of the spark plug of FIG. 1;

Y FIG. 3 is a schematic diagram of the whole of the system according to the invention;

FIG. 4 is an axial half cross-section of the insulator compacting drum;

FIG. 4A shows a detail of the compacting drum in the mold closure area;

FIGS. 48, 4c, 4D ShOW schematically the three stages of the operation of the compacting drum;

FIG. 5 is a detailed view of the axial cross-section of the insulator machining drum;

FIGS. 5A and 5B show the insulator being machined on the drum of FIG. 5; v

FIG. 6 is a plan view of the whole of the central com ponent assembly station;

FIGS6A through 6H show the various stages of the assembly of the central component of a spark plug at the station of FIG. 6;

FIG. 7 is a schematic plan view of the final assembly station;

FIGS. 7A through 7N show the various stages of the work in the final assembly station of FIG. 7;

FIG. 8 is an axial section of the insulatorintroducing drum;

FIGS. 8A and 8B are horizontal cross-sections taken approximately along lines VIIIaVIIIa and VIIIb-- VIIb in FIG. 8;

FIG. 9 is an axial section of a detail of a marking drum;

FIG. 10 is a right hand, half section of an enamelling drum utilized in the system of the invention;

FIG. 11 is an axial sectionv of an electrodeintroducing drum;

FIG. 11A is a detail sectional view taken approximately along line XIA in FIG. 11;

FIG. 11B is a horizontal section taken approximately aling line XIBXIB in FIG. 11;

FIG. 11C is a detailed view of the end piece of the electrode feed rails;

FIG. 11D is a plan view of the drum of FIG. 11;

FIG. 12 is an axial half-section of a cementintroducing drum;

FIG. 12A is a simplified horizontal section taken approximately along the plane XIIA in FIG. 12;

FIG. 13 is a partial axial section of a connecting rodintroducing drum;

FIG. 13A is a detailed horizontal section taken approximately along the plane XIIIA in FIG. 13;

FIG. 14 is a detailed axial sectional view of a'drum for positioning the lower gasket;

FIG. 14A is a plan view of a gasket-arrival slide piece;

The system comprises an insulator-production station 1, constituted, in general, by an insulator compressing and machining machine 11 and a sintering machine 12. These two machines operate in continuous kinematic motion and are interconnected through a series of transfer drums.

FIG. 148 shows the successive stages in the introduc- I tion of the gasket;

FIG. 15 is an axial cross-section of an assembly compacting drum;

FIG. 16 is a detailed axial section ofa crimping drum;

FIG. 17 is a detailed view of the axial section of a connecting-nut screwing drum;

FIG. 17A shows the axial cross-section of the area in which the nut screwing drum is associated with the transfer drum that feeds it;

FIG. 178 shows a plan view of the same area as that in FIG. 17A;

FIG. 18 is a detailed axial cross-section of a sealing control drum.

The system of the invention provides fully automated manufacture of spark plugs for internal combustion engines. In general, and without the system being limited to any specific type of spark plug, the system may be utilized in manufacturing a conventional spark plug (FIG. 1) which comprises a central subassembly a. consisting (FIG. 2) of an insulator b, rotationally symmetrical, and having an axial opening into which an electrical connection rod 0 extends. The rod 0 is connected to an electrode d. The cement e forms this electrical connection and alsoimmobilizes the rod 0 and seals the central subassembly or component a. The central component a is mounted in a metal holder f that is adapted to be screwed into the cylinder head of an engine. A seal between the holder f and the central component a is obtained at the upper part of the spark plug by means of an upper gasket h, pressed against the central component a by the crimp I. This seal is reinforced by a lower gasket k. In use of the spark plug, the holder f is screwed, so as to effect a seal, into the cylinder head of an engine, by means of a cylinder head gasket 1'. Lastly, a nut g is threaded onto the free end of the rod 0.

FIG. 3 is a schematic diagram of the whole of a system or machine for the production of spark plugs similar to the plug described above in relation to FIGS. 1 and 2.

The compressing and machining machine 11 comprises a compressing drum 111 which forms a stable insulator blank from a predetermined quantity of inorganic powder. The machining drum 112 machines this blank in order to give it a form approximating that of the final insulator b. (FIGS. 1 and 2). The machine 11 (FIG. 3) comprises a number of transfer drums 113, which transfer the blanks between the drums Ill and 112, as well as returning the vehicles receiving these blanks.

The insulator-production station 1 comprises, in addition, a sintering machine 12 which is supplied by a loading and transfer device 121, which brings the insulators into a sintering or curing tunnel I22 .and then into a cooling area 123. Four curing tunnels 122 are shown in FIG. 3; a larger or smaller number may be provided, depending on the production rate of the system and other related factors.

The loading device 121 is an endless conveyor comprising a vehicle-loading component 1211 at the outlet point of the compressing and machining machine 11, a component 1212 for distributing the vehicles carrying the insulators to the curing or sintering lines passing through the respective curing tunnels 122. On emerging from the cooling area 123, there is a combining component 1212 similar to the loading component 1212 but operating in the opposite manner. This combining component 1212' combines the four lines of vehicles into a single line.

Lastly, an unloading componnet 1211' enables the sintered insulators b to be separated from the transfer vehicles which are brought back to the loading component 1210.

The insulators I) thus manufactured in station I pass into a central component-assembly station 2. This station 2 comprises a central component-assembly machine 21 and curing station 22. The central component-assembly machine 21 comprises a certain number of working drums.

In the present case, the machine 21, shown in further detail in FIG. 6, comprises an insulator-introducing unit with a number of drums 210 and a distributor 219, in which the insulators b are placed in position in vehicles for transfer to the machine 21, a marking drum 211, where identification indicia and other marks are printed on the insulator, and a flaming drum 212 which dries the marking ink and pre-heats the insulator before its passage into an enamelling drum 213 which coats the insulator with enamel.

This assembly machine 21 also comprises an electrode-introducing unit, including a drum 214 and an electrode distributor 219, followed by proportioning and compacting drums 215, 215' for the cement, and a unit 216 for introducing the rods 0 comprising a drum 216 and a distributor 219". Following this, the assembled part is checked in an assembly control drum 217. If the result of the check is satisfactory, the vehicle and the assembled central component a pass to the vehicle changing drum 218, in which the central component a which has just been obtained, leaves the vehicle of the machine 21 and is brought into a heat-treatment vehicle V (FIG. 6H).

The machine 21 (FIG. 6) comprises a number of distributors such as the insulator distributor 219, the electrode distributor 219 and the connecting rod distributor 219". These distributors, of known construction, are connected to the corresponding drums 210, 214, 216.

The check that is made in the drum 217 consists in checking the level of the head of the rod c. Thus, if any of the constituent components are defective or are not of the required size, the level required is not reached and the vehicle is diverted from its normal trajectory and ejected from the system.

The change of vehicle effected at the drum 218 is necessary because the central component a is to be cured. For, in the assembly machine 21, the vehicles are intended simply to support the insulator b during the assembly of the component a. The assembly vehicles are subjected only to mechanical stresses. However, during heat treatment, the vehicles V must be able to withstand temperatures of above 1,000 C but do not have to withstand any further great mechanical stresses. 7

The assembly vehicles of the machine 21 are recovered by the vehicle changing drum 218 and brought back to the introducing drum 210.

The heat-treatment vehicles V enter the assembly station 2 by passing through a synchronization device such as a helicoidal-screw which brings them to the operating speed of the station 3 (FIG. 3). The empty vehicles V are brought back to the machine 21, if necessary, passing through a storage device such as the turning tables 225. On entering the machine 21, the vehicles are again synchronized in accordance with the speed of the machine 21.

These operations take place in various drums 211 tp 217 and are shown schematically in FIGS. 6A through 6H.

FIG. 6A shows the insulator b being marked, FIG. 6B shows the insulator b being flamed or pre heated, FIG. 6C shows the insulator b being enamelled, FIG. 6D shows the electrode d being introduced, FIG. 6E shows the cement e being introduced and compacted, and FIG. 6F shows the rod 0 being introduced. FIG. 6G shows the assembled but uncured central component a being checked and FIG. 6H shows the vehicles being changed, that is, the assembled central component a being transferred from the vehicle of the machine 21 to the heat-treatment vehicle V.

On leaving the assembly machine 21, the assembled central component a with its vehicle V is conveyed to the curing station 22 (FIG. 3). This curing station 22 consists of a transfer device 221 which conveys the untion 3, having passed through the storage devices 224. e

The pressing drum 223 cools the parts leaving'the curing station 22 by means of forced convection and a given mechanical pressure. As an example, the pressing operation is carried out for a period of seconds, which corresponds to the setting time of the cement e under the heating conditions of the example. On leaving the drum 223 the parts are conveyed to the final as sembly station 3. Dynamic storage devices 224 are provided between the assembly station 2 and the station 3 in order to compensate for any lack of synchronization between the station 2 and the station 3. These devices 224, for example, may comprise turning tables arranged in series. The reserves which they can carry are variable. In the particular case where the reserve is nil, the parts pass directly through the storage devices 224.

When the stations 2 and 3 are synchronized, it is advantageous to have the devices 224 half filled. If the station 2 stops operating, the station 3 can continue to operate until the reserves are exhausted. If the station 3 stops operating, station 2 can continue operating until the storage devices 224 have been filled. This allows limited shutdowns of either station 2 or station 3 without interruption of overall system operation.

Lastly, it is possible to servo-control the system so that the operating rate of the stations 2 and 3 is a function of the rate at which the storage devices 224 are filled.

The divider component 221 divides the single line of vehicles V coming from the assembly machine 21 into a certain number of parallel lines, for example, three, which pass through the respective tunnels 222 of the passage oven 22. On leaving these tunnels, a combining component 221, similar to the divider, but operating in the opposite manner, recombines the several lines again into a single line.-

In the final assembly station 3, each central component a is separated from its heat-treatment vehicle V and the vehicle is returned at the vehicle-changing drum 218 of the assembly machine 21.

The final assembly station 3 assembles the central component a into the holder f, interposing the gaskets h, i, k, and screwing the nut g (FIGS. 7A-N).

The assembly station 3 (FIG. 7) comprises a unit for introducing the holder f including a drum 301 and a drum 302 for positioning the lower gasket k. Following this, a drum 303 is provided for inserting the central component a into the holder f provided with a lower gasket k. This partial assembly is controlled in a control drum 304 and the part then passes into the unit which positions the upper gasket h, comprising the drum 305.

A drum 306 in the compacting unit places the whole into position and a cold crimping drum 307. in the crimping unit turns over the upper lip of the holder f, in order to hold the upper gasket h.

A heating drum 308 heats the holder and a drum 309 hot crimps the assembly. The connecting nut g is screwed onto the part that has been made in the screwing drum 310 of the unit for distributing the nuts g. The spark plug is then finished. A drum 311 adjusts the electrode and a drum 312 checks the seal of the spark

Patent Citations
Cited PatentFiling datePublication dateApplicantTitle
US2716267 *Jun 1, 1951Aug 30, 1955Champion Spark Plug CoMachine for assembling spark plug electrodes
Referenced by
Citing PatentFiling datePublication dateApplicantTitle
US4049389 *Apr 13, 1976Sep 20, 1977Ijun Iosifovich GrinbergMethod and apparatus for assembling aerosol valve
US4070740 *Aug 11, 1975Jan 31, 1978Automatisme & TechniqueContinuous production hot-setting installation
US4486932 *Aug 6, 1982Dec 11, 1984Apx Group, Inc.Process for making a replacement muffler
US4516659 *Feb 6, 1984May 14, 1985Apx Group, Inc.Replacement muffler and process for making same
US4569241 *Apr 16, 1984Feb 11, 1986Ratier-FigeacBall-type screw/nut systems and a process for producing them
US5706569 *Nov 28, 1995Jan 13, 1998Sumitomo Wiring Systems, Ltd.Apparatus for assembling plug joint
CN102738709A *Apr 16, 2012Oct 17, 2012日本特殊陶业株式会社Method for manufacturing spark plug
CN102738709B *Apr 16, 2012Jan 14, 2015日本特殊陶业株式会社Method for manufacturing spark plug
CN105071226A *Sep 3, 2015Nov 18, 2015温州智信机电科技有限公司Spark plug sheathing machine with monitoring and material detection functions
CN105071226B *Sep 3, 2015May 4, 2016温州智信机电科技有限公司带监控和物料检测的火花塞套护套机
CN105173150A *Sep 3, 2015Dec 23, 2015温州智信机电科技有限公司Spark plug sleeve protector with material detection
CN105173150B *Sep 3, 2015May 17, 2017沈祥明带物料检测的火花塞套护套机
Classifications
U.S. Classification445/67, 445/7, 445/66, 29/783, 29/710, 29/430
International ClassificationH01T21/02, H01T21/00, H01T13/00
Cooperative ClassificationH01T21/02
European ClassificationH01T21/02