CA2336349A1 - A method for manufacturing a resistance welding tip - Google Patents
A method for manufacturing a resistance welding tip Download PDFInfo
- Publication number
- CA2336349A1 CA2336349A1 CA002336349A CA2336349A CA2336349A1 CA 2336349 A1 CA2336349 A1 CA 2336349A1 CA 002336349 A CA002336349 A CA 002336349A CA 2336349 A CA2336349 A CA 2336349A CA 2336349 A1 CA2336349 A1 CA 2336349A1
- Authority
- CA
- Canada
- Prior art keywords
- core
- stock
- cavity
- welding tip
- welding
- Prior art date
- Legal status (The legal status is an assumption and is not a legal conclusion. Google has not performed a legal analysis and makes no representation as to the accuracy of the status listed.)
- Abandoned
Links
Classifications
-
- B—PERFORMING OPERATIONS; TRANSPORTING
- B23—MACHINE TOOLS; METAL-WORKING NOT OTHERWISE PROVIDED FOR
- B23K—SOLDERING OR UNSOLDERING; WELDING; CLADDING OR PLATING BY SOLDERING OR WELDING; CUTTING BY APPLYING HEAT LOCALLY, e.g. FLAME CUTTING; WORKING BY LASER BEAM
- B23K35/00—Rods, electrodes, materials, or media, for use in soldering, welding, or cutting
- B23K35/02—Rods, electrodes, materials, or media, for use in soldering, welding, or cutting characterised by mechanical features, e.g. shape
- B23K35/0205—Non-consumable electrodes; C-electrodes
-
- B—PERFORMING OPERATIONS; TRANSPORTING
- B23—MACHINE TOOLS; METAL-WORKING NOT OTHERWISE PROVIDED FOR
- B23K—SOLDERING OR UNSOLDERING; WELDING; CLADDING OR PLATING BY SOLDERING OR WELDING; CUTTING BY APPLYING HEAT LOCALLY, e.g. FLAME CUTTING; WORKING BY LASER BEAM
- B23K35/00—Rods, electrodes, materials, or media, for use in soldering, welding, or cutting
- B23K35/40—Making wire or rods for soldering or welding
- B23K35/402—Non-consumable electrodes; C-electrodes
Abstract
A method of manufacturing a welding tip for resistance welding includes the steps of forming stock having at least two concentric metallic layers; parti ng the stock into desired lengths, with each length having the concentric metallic layers; and applying a forming process to each length of stock so that a front end of each length defines a contact surface for resistance welding. The invention includes a welding tip for resistance welding.</SDOAB >
Description
a 04-07-2000 ;; " ,", ; ~", "' PCT/IB99/01192 . . . .. . . . . . ..
. .... . . . . . . . .
..
- . . .. . .. . .. ..
A METHOD FOR MANUFACTURING A RESISTANCE WELDING TIP
This invention relates to resistance welding. More particularly, this invention relates to a method of manufacturing a welding tip for resistance welding and to a welding tip for resistance welding.
DE-A-2554990 discloses a method of manufacturing a welding electrode having a pocket bore in the contact surface of the electrode and a bolt of a material with a high heat resistance placed in the bore. DE-A-2554990 also discloses that a welding electrode may be made from a blank cut off from a rod. "Welding Technique" 1987 35(3) 59-63 discloses a process for the manufacture of alumina dispersion strengthened composite electrodes. Such electrodes may be made from a composite rod. EP-A-97306 also discloses a resistance welding electrode formed from a swaged bar having a cylindrical portion comprising a core and a sheath.
According to a first aspect of the invention there is provided a method of manufacturing a welding tip for resistance welding, the method including the steps of:
forming an elongate stock having a metallic core and a metallic layer coaxial with the core;
parting the stock into desired lengths;
applying a first forming process to a length of stock to define a contact surface for resistance welding at a front end of the length of stock;
AMENDED SHEET
04-07-2000 ; ; , ; , ~' , ; , ~ ~ , ~' ~ PCT/1899/01192 .. . . . . . ..
. .... . . . . . . . .
~ . . . . . . . . ..
.. . .. . .. ..
. .... . . . . . . . .
..
- . . .. . .. . .. ..
A METHOD FOR MANUFACTURING A RESISTANCE WELDING TIP
This invention relates to resistance welding. More particularly, this invention relates to a method of manufacturing a welding tip for resistance welding and to a welding tip for resistance welding.
DE-A-2554990 discloses a method of manufacturing a welding electrode having a pocket bore in the contact surface of the electrode and a bolt of a material with a high heat resistance placed in the bore. DE-A-2554990 also discloses that a welding electrode may be made from a blank cut off from a rod. "Welding Technique" 1987 35(3) 59-63 discloses a process for the manufacture of alumina dispersion strengthened composite electrodes. Such electrodes may be made from a composite rod. EP-A-97306 also discloses a resistance welding electrode formed from a swaged bar having a cylindrical portion comprising a core and a sheath.
According to a first aspect of the invention there is provided a method of manufacturing a welding tip for resistance welding, the method including the steps of:
forming an elongate stock having a metallic core and a metallic layer coaxial with the core;
parting the stock into desired lengths;
applying a first forming process to a length of stock to define a contact surface for resistance welding at a front end of the length of stock;
AMENDED SHEET
04-07-2000 ; ; , ; , ~' , ; , ~ ~ , ~' ~ PCT/1899/01192 .. . . . . . ..
. .... . . . . . . . .
~ . . . . . . . . ..
.. . .. . .. ..
and applying a second forming process to the length of stock to define a cavity in an opposed rear end thereof, the cavity extending inwardly from the rear end of the metallic layer to a rear end of the metallic core, characterised in that the method includes urging material of the metallic layer behind the rear end of the core.
According to a second aspect of the invention there is provided a method of manufacturing a welding tip for resistance welding, the method including the steps of:
forming an elongate stock having a metallic core and a metallic layer coaxial with the core;
parting the stock into desired lengths;
applying a first forming process to a length of stock to define a contact surface for resistance welding at a front end of the length of stock;
and applying a second forming process to the length of stock to define a cavity in an opposed rear end thereof, characterised in that the cavity is defined in the metallic core and a portion of the core is radially deformed to provide a cavity wall.
The stock may be formed by drawing a circular cylindrical tube of a first metallic material over a circular cylindrical rod of a second metallic material. At least one of the rod and the tube may be deformed in the AMENDED SHEET
04-07-2000 ; ; , ; , ~ ~ , ; , ~ ~ , ~ ~ ~ PCT/ I B99/01192 . . . .. . . . . . .. .
. .... . . . . . . . .
_ . . . . . . . . . ..
.. . .. . .. ..
According to a second aspect of the invention there is provided a method of manufacturing a welding tip for resistance welding, the method including the steps of:
forming an elongate stock having a metallic core and a metallic layer coaxial with the core;
parting the stock into desired lengths;
applying a first forming process to a length of stock to define a contact surface for resistance welding at a front end of the length of stock;
and applying a second forming process to the length of stock to define a cavity in an opposed rear end thereof, characterised in that the cavity is defined in the metallic core and a portion of the core is radially deformed to provide a cavity wall.
The stock may be formed by drawing a circular cylindrical tube of a first metallic material over a circular cylindrical rod of a second metallic material. At least one of the rod and the tube may be deformed in the AMENDED SHEET
04-07-2000 ; ; , ; , ~ ~ , ; , ~ ~ , ~ ~ ~ PCT/ I B99/01192 . . . .. . . . . . .. .
. .... . . . . . . . .
_ . . . . . . . . . ..
.. . .. . .. ..
drawing to retain the rod in the tube once the tube has been drawn over the rod.
Instead, the stock may be formed by extruding a circular cylindrical tube of a first metallic material over a circular cylindrical rod of a second metallic material. Further instead, the stock may be formed by extruding a circular cylindrical tube of a first metallic material and simultaneously extruding a rod of a second metallic material, the tube being extruded over the rod and coaxially therewith.
The method may include shaping the length of stock so that the rear end of the length of stock defines a mounting formation for mounting the welding tip on to a resistance welding tool.
The first forming process applied to the length of stock for defining the contact surface may comprise cold forging. The second forming process applied to the length of stock for defining the cavity may comprise cold forging. The shaping of the length of stock to define the mounting formation may be by means of cold forging.
The cavity of the length of stock may be shaped to provide the mounting formation for mounting the welding tip on to the resistance welding tool. Then, an inner, cavity-defining surface of the length of stock may be shaped to provide the mounting formation for mounting the welding AMENDED SHEET
04-07-2000 ; : , ; , ~' , ; , ", " ~ PCT/I 899/01192 . . . .. . . . . . .. .
. .... . . : . . . . .
..
- . . .. . .. . .. ..
Instead, the stock may be formed by extruding a circular cylindrical tube of a first metallic material over a circular cylindrical rod of a second metallic material. Further instead, the stock may be formed by extruding a circular cylindrical tube of a first metallic material and simultaneously extruding a rod of a second metallic material, the tube being extruded over the rod and coaxially therewith.
The method may include shaping the length of stock so that the rear end of the length of stock defines a mounting formation for mounting the welding tip on to a resistance welding tool.
The first forming process applied to the length of stock for defining the contact surface may comprise cold forging. The second forming process applied to the length of stock for defining the cavity may comprise cold forging. The shaping of the length of stock to define the mounting formation may be by means of cold forging.
The cavity of the length of stock may be shaped to provide the mounting formation for mounting the welding tip on to the resistance welding tool. Then, an inner, cavity-defining surface of the length of stock may be shaped to provide the mounting formation for mounting the welding AMENDED SHEET
04-07-2000 ; : , ; , ~' , ; , ", " ~ PCT/I 899/01192 . . . .. . . . . . .. .
. .... . . : . . . . .
..
- . . .. . .. . .. ..
tip on to the resistance welding tool.
The contact surface of the length of stock may be formed in a first operation, the cavity may be formed in a second operation, and the cavity may be shaped to provide the mounting formation in a third operation. Instead, the contact surface and the cavity may be formed and the cavity may be shaped to provide the mounting formation in a single operation.
The tube may be drawn over the rod in the absence of a lubricating medium between the rod and the tube.
According to a third aspect of the invention there is provided a welding tip for resistance welding, the welding tip including a metallic body having a passage defined therethrough; and a discreet metallic core secured to the body within the passage and coterminous with the body, a front end of the body and a corresponding front end of the core being shaped to define a contact surface for resistance welding, characterised in that a cavity is defined in a rear end of the core, the cavity opening at a rear end of the core and the body and providing a mounting formation for mounting the welding tip on to a resistance welding tool.
The passage may have a first portion proximate the front end AMENDED SHEET
04-07-2000 :. .: . ". : ~ ~ ~ ~ ~ .. pCT/IB99/01192 . . . .. . . . . . ..
. . . . .... . . ~ . a . . . ~
_ . . . . . . . . . . . ~
. . .. . .. . .. ..
of the body and a second wider portion proximate the rear end of the body, the cavity being defined in a portion of the core located in the wider portion of the passage.
The contact surface of the length of stock may be formed in a first operation, the cavity may be formed in a second operation, and the cavity may be shaped to provide the mounting formation in a third operation. Instead, the contact surface and the cavity may be formed and the cavity may be shaped to provide the mounting formation in a single operation.
The tube may be drawn over the rod in the absence of a lubricating medium between the rod and the tube.
According to a third aspect of the invention there is provided a welding tip for resistance welding, the welding tip including a metallic body having a passage defined therethrough; and a discreet metallic core secured to the body within the passage and coterminous with the body, a front end of the body and a corresponding front end of the core being shaped to define a contact surface for resistance welding, characterised in that a cavity is defined in a rear end of the core, the cavity opening at a rear end of the core and the body and providing a mounting formation for mounting the welding tip on to a resistance welding tool.
The passage may have a first portion proximate the front end AMENDED SHEET
04-07-2000 :. .: . ". : ~ ~ ~ ~ ~ .. pCT/IB99/01192 . . . .. . . . . . ..
. . . . .... . . ~ . a . . . ~
_ . . . . . . . . . . . ~
. . .. . .. . .. ..
of the body and a second wider portion proximate the rear end of the body, the cavity being defined in a portion of the core located in the wider portion of the passage.
5 According to a fourth aspect of the invention there is provided a welding tip for resistance welding, the welding tip including a metallic body having a passage defined therein opening at a front end of the body; and a discreet metallic core arranged within the passage, the front end of the body and a corresponding front end of the core being shaped to define a contact surface for resistance welding and a cavity being defined in a rear end of the body, the cavity providing a mounting formation for mounting the welding tip on to a resistance welding tool, and the cavity extending inwardly from the rear end of the body to a rear end of the core, characterised in that a cold forged slug of material of the body is arranged within the cavity behind the rear end of the core.
The core and the passage may define complementary waisted axial profiles, thereby to secure the core in the passage. The cavity may be frusto-conical in shape, tapering inwardly from the rear end of the body.
The core may project from the front end of the body. Instead, the front end of the care may be substantially flush with the front end of AMENDED SHEET
04-07-2000 ~ ~ ~ ~ ~ ~ ~ ~ ~ ~ PCT/IB99/01192 ~ .~
i . ~ . ~ ~ . . ~ ~ ~ ~
. ~ . ~ ~~~~ ~ . ~ ~ t ~ ~ ~ .
_ . ~ ~ . ~ . ~ ~ . ~ . .
. ~ ~~ . .~ . ~. ~.
The core and the passage may define complementary waisted axial profiles, thereby to secure the core in the passage. The cavity may be frusto-conical in shape, tapering inwardly from the rear end of the body.
The core may project from the front end of the body. Instead, the front end of the care may be substantially flush with the front end of AMENDED SHEET
04-07-2000 ~ ~ ~ ~ ~ ~ ~ ~ ~ ~ PCT/IB99/01192 ~ .~
i . ~ . ~ ~ . . ~ ~ ~ ~
. ~ . ~ ~~~~ ~ . ~ ~ t ~ ~ ~ .
_ . ~ ~ . ~ . ~ ~ . ~ . .
. ~ ~~ . .~ . ~. ~.
the body.
One of the body and the core may be of a material having a higher electrical conductivity than the material of the other of the body and the core. One of the body and the core may be of a material having a higher tensile strength than the material of the other of the body and the core. One of the body and the core may be of a material having a higher hardness than the material of the other of the body and the core.
The body may be of substantially pure copper. The core may be of an alloy of copper. Instead, the core may be of an alloy of silver.
The alloy of copper may be one of the following:
(a) Copper-Chromium-Zirconium;
(b) Copper-Zirconium;
(c) Copper-Chromium;
(d) Copper-Nickel-Tin-Chromium;
(e) Copper-Nickel-Cobalt-Beryllium;
(f) Copper-Beryllium;
(g) Sintered Copper-Tungsten;
(h) Copper-Silver.
The invention is now described, by way of examples, with reference to the accompanying drawings.
AMENDED SHEET
One of the body and the core may be of a material having a higher electrical conductivity than the material of the other of the body and the core. One of the body and the core may be of a material having a higher tensile strength than the material of the other of the body and the core. One of the body and the core may be of a material having a higher hardness than the material of the other of the body and the core.
The body may be of substantially pure copper. The core may be of an alloy of copper. Instead, the core may be of an alloy of silver.
The alloy of copper may be one of the following:
(a) Copper-Chromium-Zirconium;
(b) Copper-Zirconium;
(c) Copper-Chromium;
(d) Copper-Nickel-Tin-Chromium;
(e) Copper-Nickel-Cobalt-Beryllium;
(f) Copper-Beryllium;
(g) Sintered Copper-Tungsten;
(h) Copper-Silver.
The invention is now described, by way of examples, with reference to the accompanying drawings.
AMENDED SHEET
In the drawings, Figure 1 shows a side sectioned view of a first embodiment of a length of stock, in accordance with the invention, for welding tips for resistance welding;
Figure 2 shows a side sectioned view of a welding tip, in accordance with the invention, for resistance welding, fabricated from the stock of Figure 1;
Figure 3 shows a side sectioned view of a second embodiment of a length of stock, in accordance with the invention, for welding tips for resistance welding;
Figure 4 shows a side sectioned view of a second embodiment of a welding tip, in accordance with the invention, for resistance welding, manufactured from the stock of Figure 3;
Figure 5 shows a length of stock to be used in the manufacture of a welding tip for resistance welding according to a method of the invention;
Figure 6 shows the length of stock in a first stage of the manufacture of the welding tip;
Figure 7 shows the length of stock in a second stage of manufacture of the welding tip;
Figure 8 shows the length of stock in a third stage of manufacture of the welding tip;
Figure 9 shows a side sectioned view of a third embodiment of the welding tip;
Figure 10 shows dimensions of the welding tip of Figure 4; and _ $
Figure 1 1 shows a side sectioned view of a fourth embodiment of the welding tip.
In Figure 1, reference numeral 10 generally indicates a length of stock, in accordance with the invention, for manufacturing welding tips for resistance welding.
The length of stock 10 includes a circular cylindrical tube 12 and a cylindrical rod 14. The tube 12 is drawn over the rod 14 in a conventional drawing process with the absence of a lubricant between the rod 14 and the tube 12.
The tube 12 is of cathodic copper while the rod 14 is of a copper alloy. The tube 12 is of a more readily deformable than the rod 14.
Thus, as the tube 12 is drawn over the rod 14, the tube 12 is deformed.
This, together with the fact that a lubricating medium is not used, results in the rod 14 being fixed within the tube 12.
The copper alloy can be chosen to suit a user's requirements.
Some examples of the copper alloy are:
(a) Copper-Chromium-Zirconium (b) Copper-Zirconium (c) Copper-Chromium (dl Copper-Nickel-Tin-Chromium _ 9 (e) Copper-Nickel-Cobalt-Beryllium (f) Copper-Beryllium It will be appreciated that, instead, the rod 14 may be of a alloy of silver.
The stock 10 can be supplied in indefinite lengths or in predetermined lengths, depending on a user's requirements. The stock 10 can also be supplied in different diameters to suit a user's requirements.
In Figure 2, reference numeral 20 generally indicates a first embodiment of a welding tip, in accordance with the invention, manufactured from the stock 10.
The tip 20 includes a body 22 having a passage 23 defined therethrough. A core 24 is fixed within the body 22. A front end 26 of the body 22 is flush with a front end 28 of the core 24.
The front ends 26, 28 of the body 22 and the rod 28, respectively, are shaped to define a contact surface 30 suitable for resistance welding. In particular, the front ends 26, 28 are shaped to define a domed profile. Those skilled in the art will appreciate that the front ends 26, 28 can be of any shape to suit a particular application.
WO 00/01507 PC'C/IB99/01192 A cavity 32 is defined in a rear end 34 of the core 24. The cavity 32 is formed so that a portion 36 of the core 24 is radially deformed to define a wall 38 which defines the cavity 32.
5 The cavity 32 is formed in a stamping operation while the body 22 is inhibited from moving radially outwardly. This results in a portion 40 of the body 22 surrounding the wall 38 being reduced in thickness.
The cavity 32 facilitates mounting of the tip 20 on to a welding 10 tool (not shownl.
In Figure 3, reference numeral 50 generally indicates a second embodiment of a length of stock, in accordance with the invention, for the manufacture of welding tips for resistance welding. With reference to Figure 2, like reference numerals refer to like parts, unless otherwise specified.
The tube 12 of the stock 50 has an outer diameter of approximately 16,0 mm. The rod 14 of the stock 50 has a diameter of approximately 6, 3 mm.
In Figure 4, reference numeral 60 generally indicates a second embodiment of a welding tip, in accordance with the invention, manufactured from the stock 50. With reference to Figure 2, like reference numerals refer to like parts, unless otherwise specified.
04-07-2000 ~ ~ ~ ~ ~ ~ ~ ~ ~ ~ PCT/IB99/01192 .. .. . . .
s . . . . . . . . . . . .
. . . . .... : . . . . . . .
- . . . . . . . . . . .
. . .. . .. . .. ..
The body 22 of the welding tip 60 defines the cavity 32. The cavity 32 is frusto-conical and tapers inwardly from the rear end 34 of the body 22.
The core 24 of the welding tip 60 is positioned in a passage 62 which extends from a front end 64 of the cavity 32 to open at the front end 26 of the body 22. The core 24 and the passage 62 define corresponding waisted axial profiles. It follows that the core 24 is effectively locked in the passage 62. The front end 28 of the core 24 is proud of the front end 26 of the body 22 to an extent of approximately 0,2 mm.
In Figures 6 to 8, there are shown three stages of transformation of a length 66 of stock 50, shown in Figure 5, to the welding tip 60 during the manufacture of the welding tip 60. With reference to Figures 1 to 4, like reference numerals refer to like parts, unless otherwise specified.
In a first stage of manufacture, a front end 68 of the length 66 of stock 50 is cold forged so that the front end 68 has a curved axial profile as shown in Figure 6. In a second stage of manufacture, the length 66 is held in a die and a circular cylindrical cavity 70 is punched into a rear end 72 of the length 66. This results in elongation of the length 66 and the formation of the core 24 positioned in the passage 62. This also has the AMENDED SHEET
04-07-2000 ; , , ; , ~ ~ , ; , ~ ~ , ~ ~ ~ PCT/1899/01192 . . . .. . . . . . ..
..... . . . . . . ..
_ . . . . . . . . . ..
.. . .. . .. .:
effect of urging the core 24 forward to stand proud as described above.
Further, as a result of the different characteristics of the rod 14 and the tube 12, the core 24 and the tube 12 are deformed so that the core 24 and the passage 62 define the complementary waisted axial profiles described above.
In a third stage of operation, the length 66 is held in a die and a tapering tool is pressed into the cavity 70 to form the frusto-conical cavity 32 described above. This results in further elongation of the tube 12 so that the body 22 reaches a desired length at this stage.
In Figure 9, reference numeral 70 generally indicates a third embodiment of a welding tip, in accordance with the invention, manufactured from the stock 50. With reference to Figures 2 and 4, like reference numerals refer to like parts, unless otherwise specified.
The welding tip 70 has the same general shape as the welding to 60 of Figure 4, and is manufactured in the same general process described above in respect of the tip 60, illustrated in Figures 5 to 8, with the exception that in forming the cavity 32, a slug 73 of the material of the body 22 is urged behind a rear end 74 of the core 24.
The following table give typical dimensions of the tip 60, illustrated in Figure 4, with reference to Figure 10:
AMENDED SHEET
A 16.Omm B 20.Omm C 8.Omm D 6.5mm E 10.3mm F 12.7mm G 0.2mm It will be appreciated that the above dimensions are for example purposes only, and may be varied to suit user requirements.
In Figure 1 1, reference numeral 80 generally indicates a fourth embodiment of a welding tip, in accordance with the invention, manufactured from the stock 50. With reference to Figures 2, 4, and 9, like reference numerals refer to like parts, unless otherwise specified.
Again, the welding tip 80 has the same general. shape as the welding to 60 of Figure 4, and is manufactured in the same general process described above in respect of the tip 60, illustrated in Figures 5 to 8, with the exception that in forming the contact surface 30, a front portion 82 is tapered to provide a more pointed profile than is the case with the tip 60.
It is a problem with welding tips that they wear out at a rate which results in excessive downtime of welding equipment and resultant high costs. The reason for this is that, generally, welding ~ tips are of a metal which has a high electrical conductivity. Such a metal is cathodic copper. Unfortunately, cathodic copper is of a relatively low tensile strength and relatively low wear resistance. Consequently, it tends to wear out at ari unacceptable rate.
It has been found that by using welding tips of a copper alloy the wear rate can be reduced. However, copper alloys do not have the high electrical conductivity of copper and this can result in certain problems.
By having the core 24 of the copper alloy and the body 22 of cathodic copper, the applicant believes it can obtain a suitable electrical conductivity together with adequate strength. Furthermore, the applicant believes that by using the method of this invention, the stock 10 can be produced at a relatively low cost.
Figure 2 shows a side sectioned view of a welding tip, in accordance with the invention, for resistance welding, fabricated from the stock of Figure 1;
Figure 3 shows a side sectioned view of a second embodiment of a length of stock, in accordance with the invention, for welding tips for resistance welding;
Figure 4 shows a side sectioned view of a second embodiment of a welding tip, in accordance with the invention, for resistance welding, manufactured from the stock of Figure 3;
Figure 5 shows a length of stock to be used in the manufacture of a welding tip for resistance welding according to a method of the invention;
Figure 6 shows the length of stock in a first stage of the manufacture of the welding tip;
Figure 7 shows the length of stock in a second stage of manufacture of the welding tip;
Figure 8 shows the length of stock in a third stage of manufacture of the welding tip;
Figure 9 shows a side sectioned view of a third embodiment of the welding tip;
Figure 10 shows dimensions of the welding tip of Figure 4; and _ $
Figure 1 1 shows a side sectioned view of a fourth embodiment of the welding tip.
In Figure 1, reference numeral 10 generally indicates a length of stock, in accordance with the invention, for manufacturing welding tips for resistance welding.
The length of stock 10 includes a circular cylindrical tube 12 and a cylindrical rod 14. The tube 12 is drawn over the rod 14 in a conventional drawing process with the absence of a lubricant between the rod 14 and the tube 12.
The tube 12 is of cathodic copper while the rod 14 is of a copper alloy. The tube 12 is of a more readily deformable than the rod 14.
Thus, as the tube 12 is drawn over the rod 14, the tube 12 is deformed.
This, together with the fact that a lubricating medium is not used, results in the rod 14 being fixed within the tube 12.
The copper alloy can be chosen to suit a user's requirements.
Some examples of the copper alloy are:
(a) Copper-Chromium-Zirconium (b) Copper-Zirconium (c) Copper-Chromium (dl Copper-Nickel-Tin-Chromium _ 9 (e) Copper-Nickel-Cobalt-Beryllium (f) Copper-Beryllium It will be appreciated that, instead, the rod 14 may be of a alloy of silver.
The stock 10 can be supplied in indefinite lengths or in predetermined lengths, depending on a user's requirements. The stock 10 can also be supplied in different diameters to suit a user's requirements.
In Figure 2, reference numeral 20 generally indicates a first embodiment of a welding tip, in accordance with the invention, manufactured from the stock 10.
The tip 20 includes a body 22 having a passage 23 defined therethrough. A core 24 is fixed within the body 22. A front end 26 of the body 22 is flush with a front end 28 of the core 24.
The front ends 26, 28 of the body 22 and the rod 28, respectively, are shaped to define a contact surface 30 suitable for resistance welding. In particular, the front ends 26, 28 are shaped to define a domed profile. Those skilled in the art will appreciate that the front ends 26, 28 can be of any shape to suit a particular application.
WO 00/01507 PC'C/IB99/01192 A cavity 32 is defined in a rear end 34 of the core 24. The cavity 32 is formed so that a portion 36 of the core 24 is radially deformed to define a wall 38 which defines the cavity 32.
5 The cavity 32 is formed in a stamping operation while the body 22 is inhibited from moving radially outwardly. This results in a portion 40 of the body 22 surrounding the wall 38 being reduced in thickness.
The cavity 32 facilitates mounting of the tip 20 on to a welding 10 tool (not shownl.
In Figure 3, reference numeral 50 generally indicates a second embodiment of a length of stock, in accordance with the invention, for the manufacture of welding tips for resistance welding. With reference to Figure 2, like reference numerals refer to like parts, unless otherwise specified.
The tube 12 of the stock 50 has an outer diameter of approximately 16,0 mm. The rod 14 of the stock 50 has a diameter of approximately 6, 3 mm.
In Figure 4, reference numeral 60 generally indicates a second embodiment of a welding tip, in accordance with the invention, manufactured from the stock 50. With reference to Figure 2, like reference numerals refer to like parts, unless otherwise specified.
04-07-2000 ~ ~ ~ ~ ~ ~ ~ ~ ~ ~ PCT/IB99/01192 .. .. . . .
s . . . . . . . . . . . .
. . . . .... : . . . . . . .
- . . . . . . . . . . .
. . .. . .. . .. ..
The body 22 of the welding tip 60 defines the cavity 32. The cavity 32 is frusto-conical and tapers inwardly from the rear end 34 of the body 22.
The core 24 of the welding tip 60 is positioned in a passage 62 which extends from a front end 64 of the cavity 32 to open at the front end 26 of the body 22. The core 24 and the passage 62 define corresponding waisted axial profiles. It follows that the core 24 is effectively locked in the passage 62. The front end 28 of the core 24 is proud of the front end 26 of the body 22 to an extent of approximately 0,2 mm.
In Figures 6 to 8, there are shown three stages of transformation of a length 66 of stock 50, shown in Figure 5, to the welding tip 60 during the manufacture of the welding tip 60. With reference to Figures 1 to 4, like reference numerals refer to like parts, unless otherwise specified.
In a first stage of manufacture, a front end 68 of the length 66 of stock 50 is cold forged so that the front end 68 has a curved axial profile as shown in Figure 6. In a second stage of manufacture, the length 66 is held in a die and a circular cylindrical cavity 70 is punched into a rear end 72 of the length 66. This results in elongation of the length 66 and the formation of the core 24 positioned in the passage 62. This also has the AMENDED SHEET
04-07-2000 ; , , ; , ~ ~ , ; , ~ ~ , ~ ~ ~ PCT/1899/01192 . . . .. . . . . . ..
..... . . . . . . ..
_ . . . . . . . . . ..
.. . .. . .. .:
effect of urging the core 24 forward to stand proud as described above.
Further, as a result of the different characteristics of the rod 14 and the tube 12, the core 24 and the tube 12 are deformed so that the core 24 and the passage 62 define the complementary waisted axial profiles described above.
In a third stage of operation, the length 66 is held in a die and a tapering tool is pressed into the cavity 70 to form the frusto-conical cavity 32 described above. This results in further elongation of the tube 12 so that the body 22 reaches a desired length at this stage.
In Figure 9, reference numeral 70 generally indicates a third embodiment of a welding tip, in accordance with the invention, manufactured from the stock 50. With reference to Figures 2 and 4, like reference numerals refer to like parts, unless otherwise specified.
The welding tip 70 has the same general shape as the welding to 60 of Figure 4, and is manufactured in the same general process described above in respect of the tip 60, illustrated in Figures 5 to 8, with the exception that in forming the cavity 32, a slug 73 of the material of the body 22 is urged behind a rear end 74 of the core 24.
The following table give typical dimensions of the tip 60, illustrated in Figure 4, with reference to Figure 10:
AMENDED SHEET
A 16.Omm B 20.Omm C 8.Omm D 6.5mm E 10.3mm F 12.7mm G 0.2mm It will be appreciated that the above dimensions are for example purposes only, and may be varied to suit user requirements.
In Figure 1 1, reference numeral 80 generally indicates a fourth embodiment of a welding tip, in accordance with the invention, manufactured from the stock 50. With reference to Figures 2, 4, and 9, like reference numerals refer to like parts, unless otherwise specified.
Again, the welding tip 80 has the same general. shape as the welding to 60 of Figure 4, and is manufactured in the same general process described above in respect of the tip 60, illustrated in Figures 5 to 8, with the exception that in forming the contact surface 30, a front portion 82 is tapered to provide a more pointed profile than is the case with the tip 60.
It is a problem with welding tips that they wear out at a rate which results in excessive downtime of welding equipment and resultant high costs. The reason for this is that, generally, welding ~ tips are of a metal which has a high electrical conductivity. Such a metal is cathodic copper. Unfortunately, cathodic copper is of a relatively low tensile strength and relatively low wear resistance. Consequently, it tends to wear out at ari unacceptable rate.
It has been found that by using welding tips of a copper alloy the wear rate can be reduced. However, copper alloys do not have the high electrical conductivity of copper and this can result in certain problems.
By having the core 24 of the copper alloy and the body 22 of cathodic copper, the applicant believes it can obtain a suitable electrical conductivity together with adequate strength. Furthermore, the applicant believes that by using the method of this invention, the stock 10 can be produced at a relatively low cost.
Claims (28)
1. A method of manufacturing a welding tip for resistance welding, the method including the steps of:
forming an elongate stock (10) having a metallic core (14) and a metallic layer (12) coaxial with the core (14);
parting the stock (10) into desired lengths (66);
applying a first forming process to a length of stock (66) to define a contact surface (30) for resistance welding at a front end (68) of the length of stock (66); and applying a second forming process to the length of stock (66) to define a cavity (32) in an opposed rear end (72) thereof, the cavity (32) extending inwardly from the rear end (72) of the metallic layer (12) to a rear end of the metallic core (12), characterised in that the method includes urging material (73) of the metallic layer (12) behind the rear end (74) of the core (14) .
forming an elongate stock (10) having a metallic core (14) and a metallic layer (12) coaxial with the core (14);
parting the stock (10) into desired lengths (66);
applying a first forming process to a length of stock (66) to define a contact surface (30) for resistance welding at a front end (68) of the length of stock (66); and applying a second forming process to the length of stock (66) to define a cavity (32) in an opposed rear end (72) thereof, the cavity (32) extending inwardly from the rear end (72) of the metallic layer (12) to a rear end of the metallic core (12), characterised in that the method includes urging material (73) of the metallic layer (12) behind the rear end (74) of the core (14) .
2, A method of manufacturing a welding tip for resistance welding, the method including the steps of:
forming an elongate stock (10) having a metallic core (14) and a metallic layer (12) coaxial with the core (14);
parting the stock (10) into desired lengths;
applying a first forming process to a length of stock to define a contact surface (30) for resistance welding at a front end of the length of stock (10); and applying a second forming process to the length of stock to define a cavity (32) in an opposed rear end thereof, characterised in that the cavity (32) is defined in the metallic core (14) and a portion of the core (14) is radially deformed to provide a cavity wall (38).
forming an elongate stock (10) having a metallic core (14) and a metallic layer (12) coaxial with the core (14);
parting the stock (10) into desired lengths;
applying a first forming process to a length of stock to define a contact surface (30) for resistance welding at a front end of the length of stock (10); and applying a second forming process to the length of stock to define a cavity (32) in an opposed rear end thereof, characterised in that the cavity (32) is defined in the metallic core (14) and a portion of the core (14) is radially deformed to provide a cavity wall (38).
3, The method as claimed in Claim 1 or Claim 2, in which the stock (10,50) is formed by drawing a circular cylindrical tube (12) of a first metallic material over a circular cylindrical rod (14) of a second metallic material.
4, The method as claimed in Claim 3, in which at least one of the rod (14) and the tube (12) is deformed in the drawing to retain the rod (14) in the tube (12) once the tube (12) has been drawn over the rod (14).
5. The method as claimed in Claim 1 or Claim 2, in which the stock (10,50) is formed by extruding a circular cylindrical tube (12) of a first metallic material over a circular cylindrical rod (14) of a second metallic material.
6, The method as claimed in Claim 1 or Claim 2, in which the stock (10, 50) is formed by extruding a circular cylindrical tube (12) of a first metallic material and simultaneously extruding a rod (14) of a second metallic material, the tube (12) being extruded over the rod (14) and coaxially therewith.
7, The method as claimed in Claim 1 or Claim 2, which includes shaping the length of stock (66) so that the rear end (72) of the length of stock defines a mounting formation for mounting the welding tip on to a resistance welding tool.
8. The method as claimed in Claim 1 or Claim 2, in which the first forming process applied to the length of stock (66) for defining the contact surface (30) comprises cold forging.
9. The method as claimed in Claim 1 or Claim 2, in which the second forming process applied to the length of stock (66) for defining the cavity (32) comprises cold forging.
10. The method as claimed in Claim 7, in which the shaping of the length of stock (66) to define the mounting formation is by means of cold forging.
11. The method as claimed in Claim 7, in which the cavity (32) of the length of stock (66) is shaped to provide the mounting formation for mounting the welding tip on to a resistance welding tool.
12. The method as claimed in Claim 11, in which the contact surface (30) of the length of stock (66) is formed in a first operation, the cavity (32) is formed in a second operation, and the cavity (32) is shaped to provide the mounting formation in a third operation.
13. The method as claimed in Claim 11, in which the contact surface (30) and the cavity (32) are formed and the cavity (32) is shaped to provide the mounting formation in a single operation.
14. The method as claimed in Claim 3, in which the tube (12) is drawn over the rod (14) in the absence of a lubricating medium between the rod (14) and the tube (12).
15. A welding tip for resistance welding, the welding tip including a metallic body (22) having a passage (23) defined therethrough; and a discreet metallic core (24) secured to the body (22) within the passage (23) and coterminous with the body (22), a front end (26) of the body (22) and a corresponding front end (28) of the core (24) being shaped to define a contact surface (30) for resistance welding, characterised in that a cavity (32) is defined in a rear end (34) of the core (24), the cavity (32) opening at a rear end (34) of the core (24) and the body (22) and providing a mounting formation for mounting the welding tip on to a resistance welding tool.
16. The welding tip as claimed in Claim 15, in which the passage (23) has first portion proximate the front end (26) of the body (22) and a second wider portion proximate the rear end of the body (22), the cavity (32) being defined in a portion of the core (24) located in the wider portion of the passage (23).
17. A welding tip for resistance welding, the welding tip including a metallic body (22) having a passage (23) defined therein opening at a front end (26) of the body (22); and a discreet metallic core (24) arranged within the passage (23), the front end (26) of the body (22) and a corresponding front end (28) of the core (24) being shaped to define a contact surface (30) for resistance welding and a cavity (32) being defined in a rear end of the body (22), the cavity providing a mounting formation for mounting the welding tip on to a resistance welding tool, and the cavity (32) extending inwardly from the rear end of the body (22) to a rear end (34) of the core (24), characterised in that a cold forged slug (73) of material of the body (22) is arranged within the cavity (32) behind the rear end (34) of the core (24).
18. The welding tip as claimed in Claim 17, in which the core (24) and the passage (23) define complementary waisted axial profiles, thereby to secure the core (24) in the passage (23).
19. The welding tip as claimed in Claim 18, in which the cavity (32) is frusto-conical in shape, tapering inwardly from the rear end of the body (22).
20. The welding tip as claimed in any one of claims 15 to 19, in which one of the body (22) and the core (24) is of a material having a higher electrical conductivity than the material of the other of the body (22) and the core (24).
21. The welding tip as claimed in any one of claims 15 to 19, in which one of the body (22) and the core (24) is of a material having a higher tensile strength than the material of the other of the body (22) and the core (24).
22. The welding tip as claimed in any one of claims 15 to 19, in which one of the body (22) and the core (24) is of a material having a higher hardness than the material of the other of the body (22) and the core (24).
23. The welding tip as claimed in any one of claims 15 to 19, in which the body (22) is of substantially pure copper.
24. The welding tip as claimed in Claim 23, in which the core (24) is of an alloy of copper.
25. The welding tip as claimed in Claim 24, in which the alloy of copper is one of the following:
(a) Copper-Chromium-Zirconium;
(b) Copper-Zirconium;
(c) Copper-Chromium;
(d) Copper-Nickel-Tin-Chromium;
(e) Copper-Nickel-Cobalt-Beryllium;
(f) Copper-Beryllium;
(g) Sintered Copper-Tungsten;
(h) Copper-Silver.
(a) Copper-Chromium-Zirconium;
(b) Copper-Zirconium;
(c) Copper-Chromium;
(d) Copper-Nickel-Tin-Chromium;
(e) Copper-Nickel-Cobalt-Beryllium;
(f) Copper-Beryllium;
(g) Sintered Copper-Tungsten;
(h) Copper-Silver.
26. The welding tip as claimed in any one of claims 15 to 19, in which the core (24) is of an alloy of silver.
27. A method of manufacturing a welding tip for resistance welding substantially as herein described with reference to the accompanying diagrammatic drawings.
28. A welding tip for resistance welding substantially as herein described with reference to the accompanying diagrammatic drawings.
Applications Claiming Priority (3)
| Application Number | Priority Date | Filing Date | Title |
|---|---|---|---|
| ZA985819 | 1998-07-02 | ||
| ZA98/5819 | 1998-07-02 | ||
| PCT/IB1999/001192 WO2000001507A1 (en) | 1998-07-02 | 1999-06-24 | A method for manufacturing a resistance welding tip |
Publications (1)
| Publication Number | Publication Date |
|---|---|
| CA2336349A1 true CA2336349A1 (en) | 2000-01-13 |
Family
ID=25587116
Family Applications (1)
| Application Number | Title | Priority Date | Filing Date |
|---|---|---|---|
| CA002336349A Abandoned CA2336349A1 (en) | 1998-07-02 | 1999-06-24 | A method for manufacturing a resistance welding tip |
Country Status (3)
| Country | Link |
|---|---|
| AU (1) | AU4639099A (en) |
| CA (1) | CA2336349A1 (en) |
| WO (1) | WO2000001507A1 (en) |
Families Citing this family (1)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| FR2859401B1 (en) * | 2003-09-10 | 2006-03-17 | Le Bronze Ind Sa | RESISTOR WELDING ELECTRODE AND METHOD FOR MANUFACTURING SAME |
Family Cites Families (6)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| US2180396A (en) * | 1938-01-27 | 1939-11-21 | James P Burke | Electrical contactor |
| FR1410358A (en) * | 1964-07-29 | 1965-09-10 | Le Bronze Ind Rene Loiseau & C | resistance welding electrode |
| DE2554990A1 (en) * | 1975-12-06 | 1977-06-16 | Kabel Metallwerke Ghh | Copper electrode for resistance welding - comprising a core of copper alloy surrounded by pure copper or high conductivity copper alloy |
| US4288024A (en) * | 1977-10-25 | 1981-09-08 | The Nippert Company | Method for making a bimetal resistance welding electrode |
| DE3381586D1 (en) * | 1982-06-18 | 1990-06-28 | Scm Corp | METHOD FOR PRODUCING DISPERSION-ENHANCED METAL BODIES AND THIS BODY. |
| JPH04339575A (en) * | 1991-03-12 | 1992-11-26 | Kobe Steel Ltd | Manufacture of resistance welding electrode |
-
1999
- 1999-06-24 AU AU46390/99A patent/AU4639099A/en not_active Abandoned
- 1999-06-24 WO PCT/IB1999/001192 patent/WO2000001507A1/en active Application Filing
- 1999-06-24 CA CA002336349A patent/CA2336349A1/en not_active Abandoned
Also Published As
| Publication number | Publication date |
|---|---|
| WO2000001507A1 (en) | 2000-01-13 |
| AU4639099A (en) | 2000-01-24 |
Similar Documents
| Publication | Publication Date | Title |
|---|---|---|
| CA1186874A (en) | Method of making a male resistance welding electrode | |
| US4288024A (en) | Method for making a bimetal resistance welding electrode | |
| DE69815356T2 (en) | METHOD FOR PRODUCING A SOLDERING IRON TIP AND PRODUCED SOLDERING IRON TIP FOR THIS | |
| CN100495585C (en) | producing method of combined material of aluminum oxide fringing copper and chromium-copper alloy | |
| IE860436L (en) | Spark plug electrode | |
| KR20030036056A (en) | Metal tube and its production method | |
| US20050092728A1 (en) | Resistance welding electrode and associated manufacturing method | |
| EP2226136B1 (en) | Method of producing metallic shell for spark plug and die for producing the metallic shell | |
| US5490408A (en) | Method of and apparatus for extruding a billet of a light metal alloy | |
| US6177647B1 (en) | Electrode for plasma arc torch and method of fabrication | |
| US6225591B1 (en) | Resistance welding electrode and process for making | |
| KR100440754B1 (en) | Resistance welding electrode and process for making | |
| US4345136A (en) | Copper bimetal brazed resistance welding electrode | |
| CA2336349A1 (en) | A method for manufacturing a resistance welding tip | |
| EP1322144A3 (en) | Method of forming an electrode | |
| KR19990036716A (en) | Heating tip and method of manufacturing the same | |
| EP3482869B1 (en) | Plasma arc torch electrode and manufacturing method thereof | |
| KR920703230A (en) | Metal Extrusion Member | |
| US20080173063A1 (en) | Torsional wire treatment drawing system | |
| EP0399334A2 (en) | Method of producing contact tip | |
| DE3221663A1 (en) | SPARK PLUG AND METHOD FOR THE PRODUCTION THEREOF | |
| JP2001219214A (en) | Wire drawing die | |
| US4706383A (en) | Electrical contact assembly with composite contact construction | |
| DE10210421B4 (en) | Electrode element for plasma torches and method for the production | |
| JP3471410B2 (en) | Manufacturing method of metal shell for spark plug |
Legal Events
| Date | Code | Title | Description |
|---|---|---|---|
| FZDE | Dead |