FR2546775A1 - METHOD AND DEVICE FOR MANUFACTURING WIRE CONNECTION NUTS FOR IGNITION CANDLES - Google Patents

Abstract

The invention relates to a method and a device for manufacturing cable connection nuts for spark plugs. THE DEVICE INCLUDES A ROTARY DISC 7 CONNECTED TO A DRIVE MECHANISM AND ON THE PERIPHERY OF WHICH THE NEGATIVE OF THE PERIPHERAL PROFILE OF THE CABLE CONNECTION NUT IS FORMED, AS WELL AS A CONCAVE 8 TOOL, INSTALLED IN A FIXED POSITION IN THE MACHINE, BY ADAPTING TO THE PERIPHERY OF THE ROTARY DISC BY MEANS OF AN INTERVAL WHICH GRADUALLY DECREASES, SO AS TO PRODUCE A GRADUAL LAMINATION OF THE BLADE PASSING BETWEEN THE TWO TOOLS 7, 8, THE PARTS BEING THEN TRANSFERRED INTO A THREADING MACHINE .

Description

A 2546775

  METHOD AND DEVICE FOR MANUFACTURING CONNECTION NUTS

OF CABLE FOR SPARK PLUGS

  The present invention relates to a method and a device for manufacturing

  cation of cable connection nuts for spark plugs. In a known manner, the central-high voltage electrode of

  spark plugs of gasoline engines and the ignition cable are re-

  connected by standard high-voltage connection sockets which are arranged so that they can be fitted to a contact plug of

  substantially cylindrical shape which is provided at the end of the

  In order to secure the connection, the connection sockets

  are provided with an elastic clamping element which engages

  the groove formed in the lateral surface of the contact plug.

  In the corresponding standards, two values are prescribed for the spark plug contact plug diameter and the connection socket hole diameter. In the interests of replacement, spark plugs are manufactured. for this reason in such a way that the connection possibility is guaranteed for both diameters For a terminal of the central electrode, a threaded spindle is used which corresponds to the small diameter contact plug

  and as a large-diameter contact plug, a connection nut is used

  cable which can be screwed onto the threaded plug and which is acces-

  sible over an envelope with a peripheral surface

standardized standard.

  The cable manufacturing nuts are made during manufacture.

  series of spark plugs, generally by machining with

  chips, and more rarely by molding, from aluminum or

of copper.

  The machining with chip formation of a material in bars with automatic lathes gives rise to a relatively large chip production and results in high costs in terms of material and

the time spent.

  The manufacture of cable connection nuts by molding requires a costly device and the melting of the metal consumes a lot of energy. The object of the invention is to create a method by which we can

  cost-effective and energy-saving production of

  The invention relates to a substantially non-falling spark plug wire rope and at the same time eliminates the aforementioned drawbacks. Another object of the invention is to create a device for carrying out the method.

  mentioned above and which thus enables cost-effective and inexpensive manufacturing of

  cable connection nuts in series production.

  Thanks to the invention, a method and a device are

  attempt to fully automate the production of spark plug wire connection nuts by the use of known devices and

  simple for scheduling and bringing parts.

  The problem is solved according to the invention in that a cylindrical blank of tubular form is advantageously manufactured in the form

  of a raw material for the cable connection nuts, for-

  cold wipe from a wire material, then the blank is rolled

  between two profiled surfaces, in particular between a continuous

  profiled cylindrical face and a concave profiled surface ,, - meanwhile the profile of the cable connection nut is gradually imprinted in the lateral surface of the blank and simultaneously the inner profile is

  established, and finally a thread is formed in the profile thus produced.

  For the manufacture of the cylindrical blank, we use

  known cold forming threads and known mechanical threading threaders The peripheral-outer profile is formed by means of a device in which the profiled cylindrical surface is placed on the periphery of a rotary disc connected to a drive and whose profile corresponds to the negative of the peripheral profile of the cable connection nut, whereas the concave profiled surface is placed on the concave surface, adjacent to the rotary disk, of a tool placed in a fixed position on the device and forming a symmetrical image of the disk profile

rotary.

  The tool placed in a fixed position fits the rotating disk so that the spacing between the uppermost surfaces of the two opposing profiles corresponds to the diameter of the blank in its inlet area and the smallest outside diameter of the cable connection nut

  in the extreme cold-forming zone and that it gradually decreases

  The rotary disk and / or the fixed tool each comprise a support shoulder on the two edges, that is to say on both sides of the profile to be formed. In the extension of the tool fixed, it is also possible to fix a concave calibration tool-from the extreme forming zone, whose profile corresponds to the profile of the fixed tool and which is spaced, over its entire length of the profile of the rotating disk

  the same distance as the adjacent end of the fixed tool.

  The main advantage of the method and device according to the invention

  ventiôn, can be considered as consisting in that, thanks to the cold forming practically free of falls, it is possible to considerably reduce p. compared to the known process and used the specific material consumption

  and energy, as well as the expense in labor time of manufacturing

  connection nuts.

  Another advantage is that the device used can be easily incorporated into the production line by means of known and simple scheduling and feeding devices, so that the process

  can be automated without difficulties and without significant expense.

  Other features and advantages of the invention will be

  prominently in the following description, given by way of example no

  FIG. 1 shows, in half sectional view, the upper portion of an alloying plug provided with the cable connection nut made in accordance with the invention; Figure 2 shows, in half section, the blank according to the invention which is arranged for the manufacture of the cable connection nut; FIG. 3 is a schematic side view of a portion, essential from the point of view of the invention, of the device serving

  to make the profile of the cable connection nut

  ble; and FIG. 4 is a sectional view of the device taken along the line AA. As shown in FIG. 1, a cable connection nut 3 produced in accordance with the invention is screwed onto a threaded plug 1 protruding from a ceramic insulator 2 The cable connection nut according to the invention differs from the cable connection nuts made by known methods only in that they comprise an internal thread extending over the whole of the hole whereas in according to the invention, only part of the inner hole is provided with an internal thread.

  no influence on the correct function of the contact card

sented.

  According to the invention, a cylindrical blank of tu-

  The bung shown in FIG. 2 is manufactured by cold-forming, without producing chips, preferably from a raw material having a volume equal to the volume of the final cable connection nut, for example from a section of son cut in series, the outer diameter of this blank corresponding outer diameter D of the final part, the wall thickness corresponding to the wall thickness of the non-deformed parts of the cable connection nut and the

  length being equal to the length of the cable connection nut.

  * The outer peripheral profile of the cable connection nut

  3 is achieved by progressively rolling the blank between a surface

  cylindrical profiled, in rotation and a concave profiled surface adapts

  to the same, the blank material being gradually impressed approximately radially in areas corresponding to a surface

  conical 4 and a groove 5, until the desired profile is obtained.

  During the formation of the peripheral profile, the material pushed inward also takes the inner profile of the nut 3 After completion of the outer forming, an internal thread 6 is formed in

  the inner surface portion which is defined by the groove 5 and

  cable connection nut 3 is then completed.

  The devices suitable for implementing the method described comprise, in the exemplary embodiment shown, the following elements: known wire unwinding and cutting machines, also known cold plastic forming means, a device for forming the profile external device, known threading devices and known devices for scheduling and transferring parts between

the different workstations.

  The device for forming the outer peripheral profile comprises a conventional machine frame, a standard-compliant drive and a

  forming unit shown diagrammatically in FIG.

  It has a rotating steel disc 7 connected to the drive mechanism.

  mounted in a fixed position in the machine frame and on the

  The negative outer circumferential profile of the cable connection nut is formed along the periphery of the rotary disk 7. A semicircular tool 8, made of steel, is installed in a fixed position in the housing. frame of the machine and having a concave surface adjacent to the rotating disc 7 which forms a symmetrical image of the profile provided on the periphery of the rotary disc 7, as shown in Figure 4 The concave surface of the tool 8 has an arc shape in which case its radius of curvature on a forming surface 12 is greater than the radius of a forming surface 13 of the disk

  7 of a value corresponding to the arithmetic average of the diameter

  outside D of the blank and the diameter d of the groove 5, and the tool 8

  is adapted to the rotary disc 7 so that the spacing of the surfaces

  these forming 12 and 13 is equal to the outside diameter D of the blank in an input zone 8a and the diameter d of the groove 5 in a zone

extreme 8 b.

  A calibrating tool 9 in the form of a circular arc is placed after the fixed tool 8 in the end zone 8b, it is fixed on the frame of the machine and has a profile identical to that of the forming surface 12, the spacing of the forming surface 12 with respect to the forming surface 13 of the rotary disk 7 being everywhere equal to the diameter

d of the groove 5.

  On both sides of the rotary disk 7, and on both sides of the concave surfaces of the fixed tool 8 and the calibration tool 9, it is

  provided support shoulders It forming stops of the forming profile.

  At a distance greater than the outer diameter D of the cable connection nut 3 from 1 to 2 mm, there is provided a separation wedge 10 which is fixed on the machine frame and the surface of which

  is tilted when viewed from the calibration tool.

  9, the wedge being loosely fitted to the peripheral surface of the

rotating disc 7.

  The operating mode of the device used to form the peripheral profile of the cable connection nut can be better understood by considering the figures: the blanks such as those indicated in FIG. 2, arrive at their order through the channel shown diagrammatically in FIG. 3 or by means of a chute, individually up to the profiled surface of the rotary disc 7 rotating in the direction indicated in the entry zone 8 a of the fixed tool 8, where they are driven by friction by the rotary disc 7 and are progressively rolled between the two profiled surfaces

  of Figure 4, placed facing each other. The material of the sketch-

  the corresponding area is gradually imbedded in the corresponding areas.

  to the conical surface 4 and the groove 5 until, at the end of the operation, the outer profile and the inner profile of the cable connection nut 3 are obtained in the end zone 8b. The calibration tool 9 then carries out the finishing and the calibration of the profile

  outside in cooperation with the rotary disk 7.

  The finished forming parts can be brought in an orderly way.

  1, via a trough shown schematically in FIG. 3 or a channel, to the threading station. The parts possibly adhering to the rotary disk 7 are detached by the

separator corner 10.

Claims (3)

  1. A method for manufacturing spark plug wire connection nuts, according to which a tubular cylindrical blank is manufactured, an outer peripheral profile is formed, and an internal profile necessary for the production of a thread is formed. of a nut and machined a nut thread, characterized in that the outer peripheral profile and the inner peripheral profile are made in a single work operation by cold forming, by gradual imprint of the outer peripheral profile during the progressive rolling of the piece between a profiled cylindrical surface and a profiled surface concave adapted to it.   2. Device for implementing the method according to the claim   1, which is composed of the essentially cold forming means   necessary for the manufacture of the tubular form blank, a   having a profiled cylindrical surface and a surface area   concave yarn for the formation of the outer profile and the inner profile, a threading means and scheduling and feeding devices essentially ensuring the connection between the different work stations of the parts, characterized in that the surface cylindrical profile is formed on the periphery of a rotating disk (7) connected to a drive mechanism and whose profile corresponds to the negative of an outer profile of a cable connection nut (3) while the profiled surface concave is formed on a surface, adjacent to the rotating disk (7), of a tool (8) installed in a fixed position in the device, the profile of the concave profiled surface forming a symmetrical image of the profile of the rotary dis (7) in that in addition the concave profiled surface is adapted to the rotary disk (7) so that the spacing of the central forming surfaces (12, 13) of the two profiles corresponds to an outer diameter (D) of the bauche in an entry zone (8 a) of the workpiece and at a diameter (d) of a finite groove (5) in an extreme zone (8b) and gradually decreases between these two zones, and -in in addition it is provided on the edges of the rotary disk (7) and / or the fixed tool (8), that is to say on 1   two sides of the forming profile (12), respectively a shoulder of May (11).   3 Device according to claim 2, characterized in that a concave calibration tool (9) in the form of a circular arc, having the same thread as the forming surface (12) of the tool (8), is connected to the tool fi (8) in the end zone (8b), and in that a central forming surface (12) of the calibration tool (9) is placed at a spacing distance from the opposite forming surface (13) of the rotating disc (7) which is equal   to the diameter (d) of the final groove (5).