CA2902839C - Improved water jacket configuration for spot welding assembly - Google Patents

Abstract

An assembly for a spot welding gun assembly comprises an arm with an end region to locate an electrode in an operative position. The arm and electrode are configured to enable a coolant exchange during use between one or more internal cooling passages in the arm and a water jacket tube in the electrode. The end region further comprises a first bore to receive the electrode and a second transverse bore.
The second transverse bore is configured to receive an insert therein, The insert further comprises a first threaded passage to be operably aligned with the one or more passages and to threadably secure the water jacket tube therein.

Description

IMPROVED WATER JACKET CONFIGURATION
FOR SPOT WELDING ASSEMBLY
FIELD OF THE DISCLOSURE
[0001] The present disclosure relates to cooling of spot welding assemblies.
BACKGROUND

[0002] Water jackets for internally ported spot welding arms are commonly attached to an arm, by threadably engaging a water jacket tube in a corresponding threaded bore directly in an aluminum body of the arm. Galvanic action arises owing to the presence of coolant at the threaded connection resulting in accelerated corrosion, which may cause early malfunction, and require expensive repair or discarding of the arm.
SUMMARY

[0003] Some aspects of this disclosure may provide a method and apparatus for that overcome some of the drawbacks of known techniques, or at least, provides the public with a useful alternative.

[0004] In an aspect, there is provided an assembly for a spot welding gun assembly comprising an arm with an end region to locate an electrode in an operative position. The arm and electrode are configured to enable a coolant exchange during use between one or more internal cooling passages in the arm and a water jacket tube in the electrode. The end region further comprises a first bore to receive electrode and a second transverse bore. The second transverse bore is configured to receive an insert therein.
The insert further comprises a first threaded passage to be operably aligned with the one or more passages and to threadably secure the water jacket tube therein.

[0005] In another aspect, there is provided a spot welding gun assembly comprising a pair of assemblies as defined in the preceding aspect.
HON-WJI/CDA

[0006] In another aspect, there is provided a method of reducing corrosion in a coolant exchange network in a support arm of a spot welding assembly comprising providing a transverse passage in the support arm to interrupt a coolant exchange network at a location in which a water jacket tube of an electrode is to be positioned on the support arm, providing an insert to sealingly extend into the transverse passage wherein the insert includes a threaded passage to threadably engage the water jacket tube.
BRIEF DESCRIPTION OF THE FIGURES

[0007] Several embodiments of the present disclosure will be provided, by way of examples only, with reference to the appended drawings, wherein:

[0008] Figure 1 is a plan view of a prior art spot welding assembly;

[0009] Figure 2 is a fragmentary perspective view of a portion of an arm of the prior art assembly of figure 1;

[0010] Figure 3 is a perspective view of an insert according to an exemplary embodiment;

[0011] Figure 4 is a side view of the insert of figure 3;

[0012] Figure 4a is a plan view of the insert of figure 3;

[0013] Figure 5 is an end view of the insert of figure 3;

[0014] Figure 6 is a fragmentary perspective assembly view of the insert of figure 3 and a spot welding assembly arm configured to receive it, according to an exemplary embodiment;

[0015] Figure 7 is a sectional view of a spot welding assembly according to figure 6;

[0016] Figure 8 is a side view of the assembly of figure 7;

HON-wnicDA

[0017] Figure 9 is a plan view of the assembly of figure 7; and

[0018] Figure 10 is a sectional view taken on line 10-10 of figure 9.
DETAILED DESCRIPTION

[0019] It should be understood that the invention is not limited in its application to the details of construction and the arrangement of components set forth in the following description or illustrated in the drawings. The invention is capable of other embodiments and of being practiced or of being carried out in various ways. Also, it is to be understood that the phraseology and terminology used herein is for the purpose of description and should not be regarded as limiting. The use of "including,"
"comprising,"
or "having" and variations thereof herein is meant to encompass the items listed thereafter and equivalents thereof as well as additional items. Unless limited otherwise, the terms "connected," "coupled," and "mounted," and variations thereof herein are used broadly and encompass direct and indirect connections, couplings, and mountings. In addition, the terms "connected" and "coupled" and variations thereof are not restricted to physical, mechanical or electrical connections or couplings. Furthermore, and as described in subsequent paragraphs, the specific mechanical and/or other configurations illustrated in the drawings are intended to exemplify embodiments of the invention. However, other alternative mechanical and/or electrical or other configurations are possible which are considered to be within the teachings of the instant disclosure.

[0020] Figures 1 and 2 show prior art versions of a spot welding gun assembly 10 with a pair of arms 12 with remote ends supporting respective electrodes 14.

[0021] Figures 3 to 10 (and starting at figure 6) show exemplary embodiments of a spot welding gun assembly 20 comprising an arm 22 with an end region 24 to locate an electrode 26 (Figure 7) in an operative position.

[0022] As will be described, the arm 22 and electrode 26 are configured to enable a coolant exchange during use between one or more internal cooling passages, in this case as shown in figure 7 as supply cooling passage 28 and a return cooling passage 30, in the arm 22 and a water jacket tube 36 in the electrode 26. The end region 24 further comprises a first bore 40 to receive the electrode 26, and the water jacket tube 36 located therein, and a second transverse bore 42. The second transverse bore 42 is configured to receive an insert therein, as shown at 50. Referring to figure 3, the insert 50 further comprises a first threaded passage 52 to be operably aligned relative to the passages 28, 30 and to threadably secure the water jacket tube 36 therein.

[0023] In some exemplary embodiments, as can be seen in figures 6 and 7, the second transverse bore 42 is formed between the passages 28, 30, as one configuration to enable the water jacket tube 36 to be in fluid communication with the supply cooling passage 28.
Furthermore, the insert 50 is configured to enable fluid communication of a return passage 30 with a return channel downstream from the water jacket tube 36, as shown generally at 54 in figure 7, which is formed by the coaxial placement of the water jacket tube 36 relative to the inner wall of hollow structure of the electrode 26.

[0024] The insert 50 may be formed from a material different to the arm 22, at least in the region of the arm 22 near the second transverse bore 42, and comprises a head portion 74 and an end portion 76. The second transverse bore 42 has a recessed entry region showed at 44 to receive the head portion 74 and an end region 46 (figure 10) complementary to the end portion 76. In the exemplary embodiment shown, the end region 46 is open, and the insert 50 is provided with a second threaded passage 78 aligned with the end region 46 to receive a threaded fastener 80 therethrough, in this case a bolt, to secure the insert 50 in position. However, other configurations may also be deployed to secure the insert 50 in position, such as by the use of a threaded extension on the insert that extends beyond second bore to threadably engage a complementary nut fastener, among others.

[0025] The insert 50 is further provided with at least a pair of o-ring receiving regions 82, 84 to receive corresponding o-rings 86, 88, as shown in figure 10, each on an opposite side of the first threaded passage 52 for sealing the coolant exchange.
Sealing may also be carried out using other measures, such as by the provision of o-rings in similar alignment, but otherwise mounted in the second transverse bore 42.

HON-WJI/CDA

[0026] In the exemplary embodiments of figures 3 to 5, the end portion 76 includes an anchor section 90 of reduced diameter to define a transition face 92 to locate o-ring 88.
Meanwhile, as shown in figure 10, the end region 46 of the second transverse bore 42 includes an anchoring zone 48 with a corresponding diameter and configured to engage the anchor section 90, with the o-ring 88 held between the transition face 92 and an adjacent face on the anchoring zone.

[0027] Returning to figure 3, the head portion 74, in this case, is oblong with a pair of aligned planar edge regions 94 to engage a corresponding pair of aligned planar surface regions 96 in the recessed entry region, as shown in figure 6.

[0028] Thus, a pair of such assemblies as shown at 20 may be used in a spot welding gun assembly of the type shown in figure 1.

[0029] Thus, in some exemplary embodiments, similar configurations may be deployed with the aim of reducing corrosion in a coolant exchange network in a spot welding assembly, by providing a transverse passage in a support arm to interrupt a coolant exchange network at a location in which a water jacket tube of an electrode is to be positioned on the support arm, and by providing an insert to sealingly extend into the transverse passage wherein the insert includes a threaded passage to threadably engage the water jacket tube. The insert may then be secured into position in the transverse passage. Provision may be made to secure the insert in place, by installing a threaded fastener through a reduced region of the transverse passage into the end portion.

[0030] Thus, some exemplary embodiments may provide a relatively inexpensive insert or adaptor to which the cooling water jacket can be attached, wherein the adaptor has a threaded feature to receive the water jacket and by its formation from copper or the like, can be configured to be relatively less reactive than aluminum at the intersection of the water jacket and the cooperating passages when in the presence of the coolant. As a result, the threaded connection may provide a longer operating life. As and when corrosion occurs, the insert or adaptor may be replaced, with minimal, if any, HON-WJVCDA

consequences to the arm itself.

[0031] The insert may be deployed in different sizes to accommodate different arm configurations and may be made from copper, as described, or alloys thereof.
Other materials may also be deployed such as zinc, magnesium and cadmium, as well as graphite. Some polymer materials may also be applicable provided that a capable threaded connection may be formed therein. Other securable connections may also be deployed, in place of threading, though perhaps at further cost.

[0032] While the present disclosure describes various exemplary embodiments, the disclosure is not so limited. To the contrary, the disclosure is intended to cover various modifications and equivalent arrangements, as will be readily appreciated by the person of ordinary skill in the art.

HON-WJI/CDA

Claims (13)

CLAIMS:

1. An assembly for a spot welding gun assembly comprising an arm with an end region to locate an electrode in an operative position, the arm and electrode configured to enable a coolant exchange during use between one or more internal cooling passages in the arm and a water jacket tube in the electrode, the end region further comprising a first bore to receive the electrode and a second transverse bore, the second transverse bore configured to receive an insert therein, the insert further comprising a first threaded passage to be operably aligned with the one or more passages and to threadably secure the water jacket tube therein.

2. The assembly of claim 1, the cooling passages including a pair of passages, the second transverse bore being formed therebetween.

3. The assembly of claim 2, the insert further comprising a head portion, the second bore further comprising a recessed entry region to receive the head portion.

4. The assembly of claim 3, the insert further comprising an end portion, the second bore further comprising an end region complementary with the end portion.

5. The assembly of claim 4, the end region being open, the insert further comprising a second threaded passage aligned with the end region to receive a threaded fastener therethrough to secure the insert in position.

6. The assembly of any one of claims 1 to 5, the insert configured to receive at least a pair of o-rings, each on an opposite side of the first threaded passage for sealing the coolant exchange.

7. The assembly of claim 6, the end portion including an anchor section of reduced diameter to define a transition face to locate a first of the o-rings, the end region including an anchoring zone with a corresponding diameter and configured to engage the anchor section, with the first o-ring held between the transition face and an adjacent face on the anchoring zone.

8. The assembly of any one of claims 3 to 7, the head portion being oblong with a pair of aligned planar edge regions to engage a corresponding pair of aligned planar surface regions in the recessed entry region.

9. The assembly of any one of claims 1 to 8, wherein the insert is formed from a material different to the arm, at least in the region of the arm near the second transverse bore.

10. A spot welding gun assembly comprising a pair of assemblies as defined in any one of claims 1 to 9.

11. A method of reducing corrosion in a coolant exchange network in a support arm of a spot welding assembly comprising providing a transverse passage in the support arm to interrupt a coolant exchange network at a location in which a water jacket tube of an electrode is to be positioned on the support arm, providing an insert to sealingly extend into the transverse passage wherein the insert includes a threaded passage to threadably engage the water jacket tube.

12. The method of claim 11, further comprising securing the insert in the transverse passage.

13. The method of claim 12, wherein the insert has a head portion and an end portion, further comprising installing a threaded fastener through a reduced region of the transverse passage into the end portion.