FIELD OF THE INVENTION
The present invention relates to a tool for soldering and, more particularly, to a tool for soldering an electrical conductor with a connection device.
BACKGROUND
A tool for soldering described in European Patent Application No. 296188A1 comprises a deformation unit having a fixed module and a movable module to deform a connection device around an electrical conductor. A solder joint is produced between the connection device and the electrical connector to further improve the electrical contact between the conductor and the connection device. The heat necessary to create the solder joint is generated by Joule effect at the junction of the electrical connector and the connection device. The tool makes it possible to obtain reliable and stable electrical connections, even when the electrical wires to be connected are small and/or made of aluminum.
The patent application EP 296188A1 describes two alternatives. In the first alternative, the electric current for creating the Joule effect circulates through a movable punch and passes into an upper surface of the electrical conductor and of the connection device to be soldered. In the other alternative, the electric current is brought through the punch, then passes through the electrical conductor and the connection device, and exits via an anvil of the fixed module.
The tool, however, consumes a great deal of electricity to reach a temperature which is sufficiently high to be able to perform the solder. Further, it is difficult to limit the heating to the desired area, notably in order to reduce the impact of the heat on any insulation present on the electrical conductor and/or the connection device.
SUMMARY
A tool for soldering an electrical conductor with a connection device includes a deformation unit plastically deforming the connection device around the electrical conductor. The deformation unit has a fixed deformation module and a movable deformation module that is movable with respect to the fixed deformation module. The fixed deformation module has an anvil with an electrical contact area on which the electrical conductor and the connection device are disposed. An electric current circulates through the electrical conductor and the connection device by passing through an electrically conductive first part of the anvil that is electrically insulated from a rest of the anvil.
BRIEF DESCRIPTION OF THE DRAWINGS
The invention will now be described by way of example with reference to the accompanying Figures, of which:
FIG. 1A is a sectional perspective view of a tool for soldering according to an embodiment;
FIG. 1B is a perspective view of an electrical conductor and a connection device;
FIG. 2A is a perspective view of a tool for soldering according to another embodiment;
FIG. 2B is a perspective view of an anvil of the tool of FIG. 2A;
FIG. 3 is a sectional perspective view of a tool for soldering according to another embodiment; and
FIG. 4 is a sectional side view of an anvil according to another embodiment.
DETAILED DESCRIPTION OF THE EMBODIMENT(S)
Exemplary embodiments of the present invention will be described hereinafter in detail with reference to the attached drawings, wherein like reference numerals refer to like elements. The present invention may, however, be embodied in many different forms and should not be construed as being limited to the embodiments set forth herein. Rather, these embodiments are provided so that the present disclosure will convey the concept of the invention to those skilled in the art. Characteristics and alternatives of any embodiment may be combined, independently of one another, with characteristics and alternatives of any other embodiment.
A tool 100 for soldering an electrical conductor 101 with a connection device 102 according to an embodiment is shown in FIG. 1A. The electrical conductor 101 and the connection device 102 are shown in FIG. 1B.
The electrical conductor 101, as shown in FIG. 1B, has a part provided with an insulation 110 and a part which is not provided with insulation and which is placed at a crimping shaft 102c of the connection device 102. The connection device 102 has a pair of crimp flanks 102a, 102b which extend along a first side and an opposite second side of the crimping shaft 102c. The crimping flanks 102a, 102b are deformed so as to surround the electrical conductor 101. A soldering area 140 corresponds to the area in which the crimping flanks 102a, 102b of the connection device 102 are soldered to each other in order to ensure the electrical contact between the electrical conductor 101 and the connection device 102. The connection device 102 also has a second set of insulation flanks 141a, 141b which are deformed around the insulation 110.
In some embodiments, in particular for a copper electrical conductor 101 of small cross-section, there may also be a soldering area directly between the copper electrical conductor 101 and the crimping shaft 102c, in addition to a solder between the crimping flanks 102a, 102b, in order to further strengthen the electrical contact.
The tool 100, as shown in FIG. 1A, has a fixed deformation module 103 and a movable deformation module 104. The deformation modules 103, 104 are used to deform the flanks 102a, 102b and 141a, 141b of the connection device 102 around the electrical conductor 101 and also to perform the soldering.
As shown in FIG. 1A, the fixed deformation module 103 is statically and immovably mounted on a fixing plate 105 while the movable deformation module 104 is movable with respect to the fixed deformation module 103, which is indicated by the double-headed arrow 106.
The fixed deformation module 103 has an anvil 107. When the tool 100 is in use, the connection device 102 and the electrical conductor 101 are placed at a peak 130 of the anvil 107 of the fixed deformation module 103.
The movable deformation module 104, as shown in FIG. 1A, has a punch 109 which may be displaced so as to press on the electrical conductor 101 and the connection device 102 in order to plastically deform the crimping flanks 102a, 102b of the connection device 102 around the electrical conductor 101 when the tool 100 is used.
The punch 109 includes several parts, as shown in FIG. 1A, including a first part 109a, a second part 109b, and a third part 109c. The first part 109a and the second part 109b press onto the electrical conductor 101, while the third part 109c presses onto the insulation flanks 141a, 141b at the insulation 110. The punch 109 is configured such that an electric current I is capable of passing through it.
The first electrically conductive part 109a of the punch 109 is electrically insulated from the rest of the punch 109. The second part 109b may be electrically insulating. In this embodiment, the punch 109 is configured such that an electric current I is capable of passing through the first conductive part 109a which is insulated from the rest of the punch 109. When the tool 100 is being used, the first part 109a of the punch 109 presses onto the electrical conductor 101 at the soldering area 140. The third part 109c presses at the insulation 110 of the electrical conductor 101. The second electrically insulating part 109b presses at a transition between the flanks 102a/b and 141a/b.
The anvil 107 of the fixed deformation module 103 is capable of making an electric current I circulate through the electrical conductor 101 and the connection device 102 while the tool 100 is being used. The anvil 107, as shown in FIG. 1A, has a first electrically conductive part 107a which is electrically insulated from the rest of the anvil 107. The anvil 107, and in particular the first part 107a, is manufactured from a steel capable of withstanding a high temperature, such that a temperature in the order of 280° C. can be achieved in the electrical connector 101 to be soldered onto the connection device 102. The steel may be, for example, the W360 SFP 57 HRC type which withstands temperatures of around 600° C.
The first conductive part 107a is insulated from a second part 107b by an insulating interface 111, shown in FIG. 1A, which forms the rest of the anvil 107. In FIG. 1A, the insulating interface 111 extends from a base 131 to the peak 130 of the anvil 107. The insulating interface 111 is, for example, a ceramic layer. In an embodiment, the surface of the peak 130 of the second part 107b of the anvil 107 is also covered with insulation or the second part 107b is made of an electrically insulating material. Thus, the electric current I may only circulate in a limited part of the anvil 107, and it is also possible to reduce the volume of the anvil 107 which will be heated, which extends the lifespan of the anvil 107. An electrical contact area 108 is formed at the peak 130 of the anvil 107, at the first part 107a.
The base 131 of the anvil 107 is fixed to the fixing plate 105 a plurality of screws 112a and 112b, as shown in FIG. 1A. The electrical connection of the anvil 107 to a current generator is also performed via one of the screws, here screw 112a, which simplifies the design of the fixed deformation module 103. The screw 112a, which crimps the electrical supply cable 113 of the current generator, is electrically conductive so as to be capable of routing the electric current in the anvil 107. The screws 112a,112b, as well as the electrical supply 113, extend into an aperture 120 inside a frame 121 on which the fixing plate 105 of the tool 100 is located.
In the embodiment shown in FIG. 1A, the anvil 107 is positioned beside a carrier strip cutting device 114 which allows the electrical conductor 101 to be cut off from a neighboring electrical conductor. An insulating element 114a is placed onto an outer surface of the carrier strip cutting device 114 in order to electrically insulate it from the anvil 107 to prevent losses of electric current circulating in the anvil 107 toward the carrier strip cutting device 114. The insulation 114a may be manufactured from a ceramic material or from another material which is electrically insulating. In another embodiment, the insulation 114a could also be placed onto an outer surface of the anvil 107.
The anvil 107 is electrically insulated with respect to the fixing plate 105. This may be performed using an insulating fixing plate 105, shown in FIG. 1A, manufactured from ceramic material, for example. In another embodiment, the fixing plate 105 may be covered with insulation at least on the area in which the anvil 107 and the fixing plate 105 are in contact. In another embodiment, insulating inserts may be introduced between the anvil 107 and the fixing plate 105.
The operation of the tool 100 will now be described in greater detail with reference to FIGS. 1A and 1B.
When the fixed deformation module 103 and the movable deformation module 104 are spaced apart from one another, the electrical conductor 101 and the connection device 102 to be assembled with one another are placed at the peak 130 of the anvil 107 in such a manner that the part of the electrical conductor 101 to be soldered and the part of the connection device 102 to be soldered are placed onto the first conductive part 107a of the anvil 107.
The punch 109 of the movable deformation module 104 is then displaced towards the anvil 107 to deform the crimp flanks 102a, 102b of the connection device 102 around the electrical conductor 101 and the insulation flanks 141a, 141b. The first conductive part 109a of the punch 109 comes back into contact with the part of the electrical conductor 101 to be soldered and the part of the connection device 102 to be soldered while the third part 109c of the punch 109 presses on the insulation flanks 141a, 141b at the insulation 110 of the electrical connector 101.
While the anvil 107 and the punch 109 are in contact with the electrical conductor 101 and the connection device 102, an electric current I is allowed to circulate via the first electrically conductive part 107a of the anvil 107. The electric current I is routed to the electrical contact area 108 at the peak 130 of the anvil 107 and then circulates through the electrical conductor 101 and the connection device 102 and thus makes it possible to solder them through the heat dissipated by Joule effect when a temperature of at least 260° Celsius is reached at the soldering area close to the electrical contact area 108. Then, as illustrated by the arrows 115, the electric current I flows out via the punch 109. By limiting the surface via which the current passes into the electrical conductor 101 and the connection device 102, it is possible to reduce the risk of damaging the insulation 110 of the electrical conductor.
In the geometry of the anvil 107 shown in FIG. 1A, the main part of the current passes through the first part 109a of the punch 109. This effect is even more pronounced if the first part 109a is electrically insulated from the rest of the punch 109. In an embodiment, the current will also be able to pass in the other direction or an alternating current will also be able to be applied.
By limiting the passage of the electric current to the punch 109 and to only one part of the anvil 107, the tool 100 makes it possible to improve the control of the heating area and to facilitate or even improve the solder compared with the tool known from the prior art. In an embodiment, with an electric current of around 750A at an applied voltage in the order of 1 to 2 V, the solder joint may be obtained in approximately 150 milliseconds. The supply of electric current is then interrupted. The electrical connector 101 and the connection device 102 which are soldered then cool for 200 to 300 milliseconds before being freed by the displacement of the punch 109 of the movable deformation module 104 to open the tool 100.
A tool 200 according to another embodiment, as shown in FIGS. 2A and 2B, includes a fixed deformation module 203 and a movable deformation module 204 which operate in the same manner as the fixed deformation module 103 and movable deformation module 104 from the first embodiment but with a punch 209 and an anvil 207 with a different structure. Elements bearing the same reference numbers as in the first embodiment of the invention illustrated in FIGS. 1A and 1B will not be described anew, but reference is made to the descriptions thereof above.
The punch 209 of the movable deformation module 204, as shown in FIG. 2A, includes several parts, including an electrically conductive first part 209a. In an embodiment, the first part 209a may be insulated from the rest of the punch 209, for example via a second electrically insulating part 109b and a third part 109c. The punch 209 is therefore also configured in such a manner that the electric current I is capable of passing through the punch 209.
The first part 209a of the punch 209, as shown in FIG. 2A, has an aperture 216. The first conductive part 209a and the second part 109b, which is electrically insulating, of the punch 209 are partially separated by a gap 217 or a slot. The aperture 216 may be of any shape and may or may not entirely pass through the first part 209a. In some embodiments, there may also be several apertures 216 of the same and/or different sizes and shapes. Similarly, instead of having a gap 217 between the first part 209a and the second insulating part 109b, there may be several gaps 217 of the same sizes and shapes and/or different sizes and shapes. In another embodiment, an aperture 216 or a gap 217 may be present. The aperture 216 may be of 5 millimeters by 5 millimeters in size over the entire thickness of the punch 209. The gap 217 may measure 8 millimeters high by 0.2 millimeters deep.
The use of the apertures 216 and/or gaps 217 makes it possible to bring the hottest area closer to the electrical contact area 108, and therefore to the area in which attempts are made to reach the highest temperature to be able to perform the solder. The hottest point in the anvil 207 is positioned just below the peak 230 of the anvil 207. Thus, after the current has been cut, fast cooling of the soldered-together electrical connector 101 and the connection device 102 is obtained.
The fixed deformation module 203, as shown in FIGS. 2A and 2B, has an anvil 207 which has the same function and the same electrical supply as the anvil 107 described in the embodiment of FIG. 1A. The anvil 207 is manufactured from the same materials with the same properties as the anvil 107.
The anvil 207, as shown in FIGS. 2A and 2B, has a first conductive part 207a which is electrically insulated from a second part 207b. In contrast to the anvil 107, the insulating interface of the anvil 207 comprises two parts 211a and 211b. The first part 207a and the second part 207b of the anvil 207 are insulated from one another by an aperture 211a at a base 231 of the anvil 207. At the peak 230 of the anvil 207, the two parts 207a and 207b are electrically insulated by an insulating interface 211b. In an embodiment, the insulating interface 211b is made of ceramic material, but could also be made of diamond-type carbon or of another electrically insulating material. In an embodiment, the first part 207a of the anvil 207 has one or more apertures like the punch 209 to be able to displace the point of the hottest area toward the electrical contact area 108.
In an embodiment, a peak 230b of the second part 207b, shown in FIG. 2B, may also be covered with a ceramic or diamond-type carbon insulating coating in order to improve its electrical insulation close to the electrical contact area 108 located on the first part 207a of the anvil 207. As the second part 207b of the anvil 217 may be heated only by mechanical contact with the first part 207a of the anvil 207 in which the electric current I circulates, the insulating coating is less thermally loaded than if it was performed directly on the first part 207a of the anvil 207. The electric current I may therefore only circulate in a limited part of the anvil 207. The soldering area 140 during use can therefore be better controlled.
As shown in FIGS. 2A and 2B, a part 207a of the anvil 207 is also electrically insulated with respect to the fixing plate 205 via an insulating coating 250. Furthermore, the fixing plate 205 and thus the coating 250 is provided with a channel 218 in order to insulate to an even greater degree the first and second parts 207a and 207b of the anvil 207, each being fixed at one side of the channel 218, respectively. In an embodiment, the fixing plate 205 may be made of an insulating material or comprise inserts of an insulating material.
The operation of the tool 200 is similar to that of the tool 100 described in greater detail in the description of FIG. 1A. The particular geometry of the punch 209 and of the anvil 207 makes it possible to control the localization of the heating area and to concentrate the heat toward the electrical contact area 108 and thus in the soldering area 140 of the electrical conductor 101 and the connection device 102 in order to facilitate the soldering.
A tool 300 according to another embodiment, as shown in FIG. 3, includes a movable deformation module, which is not shown in FIG. 3 but may be structurally similar to the deformation module 104 or to the deformation module 204 which are described in the two preceding embodiments. In the tool 300, the punch is isolated from the earth in order to avoid the punch losing current. Elements bearing the same reference numbers as in the preceding embodiments will not be described anew, but reference is made to the descriptions thereof above.
A fixed deformation module 303, as shown in FIG. 3, has an anvil 307 capable of making an electric current I circulate through the electrical conductor 101 and the connection device 102. The anvil 307 has two electrically conductive parts 307a and 307b which are electrically insulated from one another by an insulating interface 311. The insulating interface 311 is, for example, a ceramic layer which extends from a base 331 to a peak 330 of the anvil 307. The anvil 307 is manufactured from the same materials with the same properties as those set out in the description of the first and the second embodiments of the anvil 107, 207.
The anvil 307, as shown in FIG. 3, is fixed to the fixing plate 105 by a plurality of screws 112a, 312b introduced into the aperture 120 in the frame 121. The electrical connection with the anvil 307 is produced for the first and the second parts 307a and 307b of the anvil 307. The connection with a current generator is also established via screws 112a, 312b, which simplifies the design of the fixed deformation module 303. The screws 112a, 312b, which crimp the electrical supply cables 113 of the current generator, are therefore conductive in order to be capable of making the electric current flow into and out of the anvil 307.
The operation of the tool 300 will now be described in greater detail with reference to FIG. 3. The plastic deformation of the crimping flanks 102a, 102b and of the insulation flanks 141a, 141b of the device 102 around the electrical conductor 101, shown in FIG. 1B, is accomplished in the same manner as in the first and second embodiments by the punch of the movable deformation module.
In the tool 300, the electric current I is routed into the first part 307a from the base 331 to the peak 330 of the anvil 307 and then circulates through the electrical conductor 101 and the connection device 102 then, as illustrated by the arrows 115, the electric current I returns into the second part 307b of the anvil 307 and exits from the second conductive part 307b to the base 331 of the anvil 307. In other embodiments, the current I may also pass in the other direction or an alternating current may be used.
The electrical contact area 108 is located on the first part 307a and the second part 307b of the anvil 307, as shown in FIG. 3. The electric current which serves to heat the conductor 101 and the connection device 102 therefore passes only into the fixed part of the deformation module 303. Given that, the electric current I does not pass into the punch of the fixed deformation module, the contact geometry of which is typically more complex than that of the anvil 307, and which, moreover, corresponds to a moving element, this third embodiment thus makes it possible to simplify the electrical assembly.
A tool 400 according to another embodiment, as shown in FIG. 4, includes an anvil 407 that is different from the anvil 307.
The anvil 407, as shown in FIG. 4, has a first electrically conductive part 407a and a second electrically conductive part 407b which are directly linked without the interposition of electrical insulation at their peak 430 at the electrical contact area 108. Moreover, the first and the second parts 407a 407b are electrically insulated from one another by an aperture 416 at a base 431 of the anvil 407. As in the tool 300, the anvil 407 may be fixed to a fixing plate 105 and be electrically connected thereto. In an embodiment, instead of using an aperture 416 to insulate the two parts 407a, 407b at the base 431, it is also possible to arrange insulation such as a ceramic layer or diamond-type amorphous carbon layer.
In the tool 400, the electric current 415 not only passes through the conductor 101 and the connection device 102 at the electrical contact area 108 to form the soldering area 140, as in the tool 300 from FIG. 3, but also just below the peak 430 of the anvil 407. The operation of the tool 400 nevertheless remains similar to that of the tool 300. This is because the electric current which serves to heat the soldering area 140 also passes only into the fixed part of the deformation module. In this embodiment, the electric current I does not pass into the punch, the contact geometry of which is typically more complex than that of the anvil 407, and which, moreover, corresponds to a moving element, this embodiment thus also makes it possible to simplify the electrical supply needs for ensuring the soldering.
Patent Application
20200044369
