CN106312257B

CN106312257B - Holding device for welding

Info

Publication number: CN106312257B
Application number: CN201510329422.8A
Authority: CN
Inventors: 徐扬; 刘照鸿; 张玉亮
Original assignee: High Almost Finite Co
Current assignee: High Almost Finite Co
Priority date: 2015-06-15
Filing date: 2015-06-15
Publication date: 2020-03-24
Anticipated expiration: 2035-06-15
Also published as: CN106312257A

Abstract

The invention provides a holding device (1) for welding, the holding device (1) comprising: a body (10), the body (10) comprising a holding aperture (140) configured for holding at least one workpiece (61) to be welded; wherein a shielding gas passage (162) for flowing a shielding gas for welding is provided in the body (10), and the shielding gas passage (162) is opened toward a welding operation side in the vicinity of the holding hole (140).

Description

Holding device for welding

Technical Field

The invention relates to a holding device for welding.

Background

The statements in this section merely provide background information related to the present disclosure and may not constitute prior art.

In practical applications, it is known to be necessary to weld a workpiece, such as a tubular member, to another workpiece, such as a plate-like member. When these workpieces are welded, for example, by a welding method such as GTAW (gas tungsten arc welding), protective gas from a welding tool mainly protects the front surface side of the welded portion, but it is difficult to effectively protect the back surface side of the welded portion.

Disclosure of Invention

According to one aspect of the present invention, a holding device for supplying a welding shielding gas to a workpiece to be welded is provided.

According to another aspect of the present invention, there is provided a holding device for welding, the holding device including: a body comprising a holding aperture configured for holding at least one workpiece to be welded; wherein a shielding gas passage through which a shielding gas for welding flows is provided in the body, and the shielding gas passage is opened toward a welding operation side near the holding hole.

Preferably, the shielding gas passage extends partially or completely around the periphery of the holding aperture.

Preferably, the body is provided with an inlet passage in fluid communication with the shielding gas passage.

Preferably, the air inlet channel is provided with an air inlet joint connected with an external protective gas source.

Preferably, the cross-sectional shape of the holding orifice includes at least one of a circular shape, an oval shape, a square shape, a T shape, and an L shape.

Preferably, the holding device further comprises a height adjustment device for adjusting the height of the holding device.

Preferably, the holding device further comprises a cover plate covering the shielding gas channel, the cover plate having evenly distributed gas discharge holes, the gas discharge holes being in fluid communication with the shielding gas channel.

Preferably, the holding device further comprises a sealing member located between the body and the cover plate, wherein the sealing member has a slit for passage of a shielding gas.

Preferably, the cover plate is formed with a groove around the vent hole such that a shielding gas enrichment zone is formed within the groove.

Preferably, the body is provided with a recessed land around the retaining aperture, the cover plate and the sealing member being seated within the recessed land flush with the surface of the body.

Preferably, the body comprises a first base provided with a first portion of the retaining aperture and a second base provided with a second portion of the retaining aperture, the first and second portions cooperating to form the retaining aperture.

Preferably the holding aperture holds the at least one workpiece which is a tubular member and at least one other workpiece which is a plate-like member is formed with an aperture which mates with the tubular member and rests on a surface of the body.

Preferably, the holding means is provided with at least one holding member for holding the at least one further workpiece against the surface of the body.

Preferably, the first substrate is provided with a first channel portion of at least one shielding gas channel, the second substrate is provided with a second channel portion of the at least one shielding gas channel, the first channel portion and the second channel portion being in fluid communication at a surface where the first substrate and the second substrate are joined to each other.

Preferably, the first and second channel portions of the at least one shielding gas channel extend 90 ° around the outer circumference of the first and second portions of the retaining aperture, respectively.

Preferably, the first and second substrates are clamped together by a clamping mechanism.

Preferably, one of the first and second substrates is provided with an alignment pin, and the other of the first and second substrates is provided with an alignment hole into which the alignment pin is inserted.

Further areas of applicability will become apparent from the description provided herein. It should be understood that the specific examples and embodiments described in this section are for illustrative purposes only and are not intended to limit the scope of the invention.

Drawings

The drawings described herein are for illustration purposes only and are not intended to limit the scope of the present disclosure in any way, the drawings are not to scale and some features may be exaggerated or minimized to show details of particular components. In the drawings:

FIG. 1 is a perspective view of a holding device for welding according to an embodiment of the present invention;

FIG. 2a is a side view of a holding device according to an embodiment of the invention;

FIG. 2B is a cross-sectional view taken along line B-B in FIG. 2 a;

FIG. 3a is a top view of a holding device according to an embodiment of the invention;

FIG. 3b is a cross-sectional view taken along line C-C in FIG. 3 a;

FIG. 4 is another side view of a holding device according to an embodiment of the invention;

FIG. 5 is an exploded schematic view of a holding device according to an embodiment of the invention;

FIG. 6 is a perspective view of a second base of a retaining device according to an embodiment of the present invention;

FIG. 7 is a top view of a second base of a retaining device according to an embodiment of the present invention;

fig. 8 is a perspective view of the second base body of the holder device assembled with the cover plate, the seal member, and the holder according to the embodiment of the present invention, in which the supply direction of the shielding gas is shown;

FIG. 9a shows a first workpiece and a second workpiece to be welded together, wherein the first workpiece and the second workpiece are separated from each other and the first workpiece is seated on a base plate;

FIG. 9b shows a first and second work piece to be welded together, wherein the first work piece passes through the aperture of the second work piece and shows weld A;

FIG. 10 is a perspective view of a holding device according to an embodiment of the present invention assembled with a first workpiece and a second workpiece in use;

FIG. 11 is a perspective view of a holding device according to an embodiment of the present invention assembled with only a first workpiece; and

fig. 12 is a side view of a holding device assembled with a first workpiece and a second workpiece according to an embodiment of the invention.

Detailed Description

The following description is merely exemplary in nature and is not intended to limit the present disclosure, application, or uses. It should be understood that throughout the drawings, corresponding reference numerals indicate like or corresponding parts and features. For purposes of clarity, not all of the components in the drawings are labeled.

Throughout the drawings, it is noted that references herein to directional terms such as front, rear, left, right, up, down, etc., are for descriptive purposes only and are not intended to limit the orientation and direction of embodiments of the invention in practical use.

The basic structure and operation method of the holding device for welding according to the embodiment of the present invention will be described below with reference to fig. 1 to 12.

Referring first to fig. 1, a holding device 1 according to an embodiment of the present invention includes a body 10 and various accessories, such as a clamping mechanism 20, an intake connector 30, a holder 40, and the like.

The body 10 comprises at least one holding aperture 140, said holding aperture 140 extending through the holding device 1 and being configured for receiving at least one workpiece to be welded. In the present embodiment, the body 10 comprises two holding apertures 140 having a substantially circular cross-section. In other embodiments, it is contemplated that the body 10 may include any number of retention apertures 140 and that the cross-section of the retention apertures 140 may be any shape, such as circular, triangular, square, oval, T-shaped, L-shaped, and the like. It is also conceivable that the holding aperture 140 is not completely closed in the lateral direction, but may be open in the lateral direction. In other words, the present holding device 1 may completely surround the above-mentioned at least one workpiece or partially surround the workpiece. It is emphasized that although referred to herein as a "holding aperture", it is understood that it is essentially a holding portion that holds the workpiece to be welded, as described above, there are a number of options for the shape of the holding portion, preferably the shape of the holding portion substantially matches the shape of the workpiece to be welded.

Referring to fig. 2a, fig. 2a shows a side view of the holding device 1, the holding device 1 preferably being provided with an air inlet connection 30 on its side surface (the surface as shown in fig. 2a), one end of the air inlet connection 30 being connected to an air inlet channel 164 (see fig. 2b), and the other end of the air inlet connection 30 being connected to a (e.g. external) shielding gas source (not shown).

Referring to fig. 2b, the inlet channel 164 is open at the side of the holding device 1 and extends inward as far as the shielding gas channel 162. In use, the inlet fitting 30 introduces shielding gas into the shielding gas passage 162 via the inlet passage 164, the shielding gas passage 162 being open to the welding operation side, so as to direct shielding gas from the shielding gas source to the welding operation side, in particular to the back side of the weld of another work piece to be welded resting on the holding device 1. In the present embodiment, two intake fittings 30 are shown connected to respective intake passages 164, which in turn are connected to the shielding gas passages 162 that are not communicated with each other. However, it is contemplated that in other embodiments, multiple shielding gas passages 162 within the body 10 may be in direct fluid communication with each other or share a single inlet passage 164 or inlet fitting 30. It is contemplated that the shielding gas source may be an internal shielding gas source or an external shielding gas source. It is contemplated that multiple shielding gas passages may be used for different types of shielding gases. It is contemplated that intake passage 164 may be disposed elsewhere in the present retention device or open at other surfaces. Even intake passage 164 may be omitted.

Referring to fig. 2b, preferably the shielding gas channel 162 is positioned as close as possible to the holding aperture 140 and extends around the holding aperture 140 through an angle which may be any angle between 0 ° and 360 °, such as 45 °, 90 °, 180 ° and 360 °. Preferably, the shielding gas passage 162 is annular or a portion of an annular shape.

Referring to fig. 3a, a gas discharge hole 132 (described in detail below) is provided on an upper surface (i.e., a surface facing the side of the welding operation) of the holder 1, the gas discharge hole 132 being located at an open side of the shielding gas passage 162 so as to guide the shielding gas out of the holder 1. Fig. 3b shows a cross-sectional view along the line C-C in fig. 3 a. As can be seen in fig. 3b, the shielding gas passage 162 is open to the welding operation side, so that the shielding gas is directed directly to the back side of the weld of the workpieces to be welded.

Fig. 4 shows a further side view of the holding device 1, a holder 40 being provided on the surface of the body 10 facing the side of the welding operation, a step being provided on the side of the holder 40 facing the body 10, whereby a clamping space S is defined between the holder 40 and the body 10 for accommodating at least one further workpiece to be welded resting on the surface of the holding device 1 for holding said at least one further workpiece between the holder 40 and the body 10. The thickness of the S space corresponds approximately to the thickness of at least one other workpiece. It is conceivable that the S space may not adjoin the holding device 1 but be at a distance from the holding device 1, whereby the at least one further workpiece may be held at a distance from the holding device 1.

Fig. 5 shows an exploded view of the present holding device 1, as shown in fig. 5, the body 10 is composed of two substrates, namely a first substrate 11 and a second substrate 12. It is contemplated that in other embodiments, the body 10 is formed of three or more substrates, and the body 10 may be a unitary piece having the retaining orifice 140 and shielding gas channel 162 described above disposed thereon or therein.

The present holding device 1 may further include a clamping mechanism 20. In the present embodiment, the holding device 1 has two clamping mechanisms 20, the two clamping mechanisms 20 being respectively provided on both sides of the body 10 and each being coupled to the first base 11 and the second base 12, for example, by fasteners. The clamping mechanism 20 is movable between a first position, in which the clamping mechanism 20 allows the first substrate 11 and the second substrate 12 to be separated from each other, and a second position; in the second position, the clamping device 20 presses or clamps the first substrate 11 and the second substrate 12 together. The clamping mechanism 20 may be, for example, a quick-grip toggle clamp or any other clamp known in the art capable of quick-grip and release.

The first substrate 11 and the second substrate 12 divide the holding aperture 140 into two portions 142, 144 (refer to fig. 1) such that the first portion 142 of the holding aperture 140 is disposed on the first substrate 11 and the second portion 144 of the holding aperture 140 is disposed on the second substrate 12. Preferably, in the present embodiment, the first base 11 and the second base 12 bisect the two substantially circular-section holding apertures 140 along their axes. The first and

second portions

142, 144 form the retention aperture 140 and retain, preferably clamp, at least one workpiece when the first and

second substrates

11, 12 are mated together. Such as providing sizing for the tubular member being retained.

Preferably, in the present embodiment, the first substrate 11 and the second substrate 12 have substantially the same structure and are symmetrical with respect to the joint surface of the two.

Preferably, the first substrate 11 and the second substrate 12 divide the at least one shielding gas channel 162 into two

portions

162A, 162B, with particular reference to fig. 2B, the first substrate 11 is provided with a first channel portion 162A of the shielding gas channel 162, the second substrate 12 is provided with a second channel portion 162B of the shielding gas channel 162, the first channel portion 162A and the second channel portion 162B being connected or in fluid communication at the surface where the first substrate 11 and the second substrate 12 are joined to each other.

A recessed land 150 is provided on the surface of the body 10 or the

base bodies

11, 12 on the side toward the welding operation, radially outside the holding hole 140. Referring to fig. 6 and 7, in the present embodiment, the recessed table 150 is preferably opened toward the holding aperture 140 and the welding operation side, and the shielding gas passage 162 is opened toward the bottom surface of the recessed table 150. Preferably, the protective gas channel 162 is closed on the side facing the holding opening 140 by a thin wall 166 formed by the

basic bodies

11, 12. Preferably, the shielding gas passage 162 is annular or a portion of an annular shape around the periphery of the retention orifice 140 that is substantially coaxial with the retention orifice 140.

The height of the lands 150 is considerably smaller than the height of the

substrates

11, 12, for example the former being one quarter or even less of the latter. Preferably, in this embodiment, the recessed land 150 is in the form of a quarter ring coaxial with the circular retaining aperture 140. In the present embodiment, four recessed lands 150 are provided on the body 10, and one recessed land 150 is provided radially outward of each of the first and

second portions

142 and 144 of the two holding apertures 140.

Preferably, with reference to fig. 7, the first and

second channel portions

162A, 162B of the shielding gas channel 162 have openings on the side of the

substrates

11, 12 facing each other, which openings are correspondingly aligned when the

substrates

11, 12 are fitted together, so that the first and

second channel portions

162A, 162B are in fluid communication with each other through the openings. As shown in fig. 2B, the first channel portion 162A and the second channel portion 162B on the first substrate 11 and the second substrate 12, respectively, are in fluid communication through openings facing each other and form a continuous shielding gas channel 162, which continuous shielding gas channel 162 is preferably semi-annular, i.e. extends 180 ° in the circumferential direction. In other embodiments, the continuous shielding gas channel may extend in the circumferential direction at any angle, such as 90 °, 270 °, or 360 °. In other embodiments, the respective channel portions of the shielding gas channels may not be in direct communication with each other, i.e., the respective channel portions of the shielding gas channels do not form openings at the facing junction surfaces, and the channel portions of each shielding gas channel may be in direct fluid communication with the inlet channel 164 or the inlet fitting 30, respectively.

Optionally, a cover plate 130 covering the shielding gas channel 162 may be disposed within the recessed land 150. In the present embodiment, referring to fig. 5, the cover plate 130 is preferably in the form of a quarter ring and is substantially the same shape as the recess 150. In this embodiment, it is preferred that the cover plate 130 has an outer surface that is flush with the outer surface of the body 10 or the

base

11, 12 when seated on the recessed station 150 on the side of the welding operation, thereby providing a flat surface for another workpiece to be welded to rest thereon.

A gas discharge hole 132 is formed in the lid plate 130, the gas discharge hole 132 extending through the lid plate 130, one end of the gas discharge hole 132 being in fluid communication with the shielding gas passage 162, and the other end thereof being open toward the welding operation side for guiding the shielding gas in the shielding gas passage 162 of the holder 1 toward the welding operation side. Preferably, the vent hole 132 is disposed as close as possible to the holding aperture 140. Preferably, the cover plate 130 includes a plurality of gas discharge holes 132, and the plurality of gas discharge holes 132 are equally spaced or uniformly arranged around the holding aperture 140 so that the shielding gas flows out of the holding device 1 in a uniformly distributed manner to be uniformly delivered to the back side of the welded portion of the work to be welded.

In the present embodiment, a sealing member 170, such as a rubber packing, is preferably provided between the body 10 and the cover plate 130 within the recessed table 150, and the sealing member 170 has a slit 172 for passage of the shielding gas. The seal member 170 prevents the shielding gas from leaking out of the holding fixture 1 in the lateral direction (i.e., the transverse direction) between the body 10 and the lid plate 130, while allowing the shielding gas to be intensively delivered toward the welded portion on the side of the welding operation. Preferably, the cutout 172 is formed on the sealing member 170 near the retaining aperture 140 (i.e., radially inward of the sealing member 170) and is generally aligned with the shielding gas channel 162 in a direction in which the shielding gas channel 162 is open, thereby allowing the shielding gas to flow through the cutout 172 into the vent hole 132 of the cover plate 130.

In the present embodiment, for example, fixing holes are provided on the

base bodies

11 and 12, the seal member 170, and the cover plate 130, respectively, to fix the cover plate 130 and the seal member 170 to the

base bodies

11, 12 by means of the fasteners 80, as shown in fig. 5.

Preferably, alignment means are provided on the

substrates

11, 12. As shown in fig. 5, alignment pins 15 and alignment holes 16 are provided on the surfaces of the

substrates

11, 12 facing each other, respectively, and when the

substrates

11, 12 are mated together, the alignment pins 15 are inserted into the alignment holes 16, thereby aligning the

substrates

11, 12 with each other and, in turn, aligning the first and

second portions

142, 144 of the holding aperture 140 with each other.

Fig. 8 shows a perspective view of the second base body 12 assembled with the cover plate 130, the seal member 170, and the holder 40, in which the supply direction of the protective gas is shown in operation. The shielding gas from the shielding gas source flows to the exhaust hole 132 via the gas inlet joint 30, the gas inlet passage 164, and the shielding gas passage 162, and then exits the exhaust hole 132 in the direction indicated by the arrow in fig. 8 (toward the welding operation side). Also shown in fig. 8 is a groove 134 located around the vent hole 132, which will be described in detail below.

Fig. 9a and 9b show a base plate 60, a first workpiece (which is comprised in the at least one workpiece) 61 and a second workpiece (which is comprised in the at least one further workpiece) 62, wherein the first workpiece 61 is connected to the base plate 60. It should be noted that the base plate 60 should be understood as any member to which the first workpiece 61 is attached, and is not limited to the shape and structure shown in the drawings. As shown in fig. 9a, four substantially identical first workpieces 61 extend over the base plate 60, the first workpieces 61 being tubular in this embodiment. In view of structural stability and the like, in practical applications, it is necessary to weld the second workpiece 62 on two or more first workpieces 61, and in the present embodiment, the second workpiece 62 includes a plate-like member. The second piece 62 has a corresponding aperture 64 formed therein for receiving the first piece 61. As shown in fig. 9b, the second workpiece 62 is fitted over at least one of the first workpieces 61 such that the first workpiece 61 passes through an aperture 64 in the second workpiece 62. In the present embodiment, welding is performed at a position where the first workpiece 61 is in contact with or close to the second workpiece 62, on the facing (i.e., adjacent) sides of two first workpieces 61 provided with the same second workpiece 62, the position of the welded portion a being schematically shown in fig. 9 b. In other embodiments, the weld a may be arbitrarily selected as needed, and for example, the weld may be formed at any position or positions in the circumferential direction of the first workpiece 61, or take other forms, such as being formed as a continuous weld. In the present embodiment, as shown in fig. 9b, spot welding is performed at point a from above in the drawing, that is, from the front side of the welded portion a. During welding, it is necessary to supply a shielding gas from below in fig. 9b, i.e., the back side of the welded portion a, in order to prevent oxidation of the back side of the welded portion a.

The operation method of the present holding apparatus 1 will be described below with reference to fig. 10.

In use, as shown in fig. 10, first, the second workpiece 62 is placed at a suitable welding position or height, then the first and

second substrates

11, 12 are moved from both sides towards the second and

first workpieces

62, 61, respectively, preferably aligned by the alignment mechanism, and finally merged and mated together, optionally with the clamping mechanism 20 such that the second workpiece 62 is held between the holder 40 and the

substrates

11, 12 while the first workpiece 61 is held within the holding aperture 140. Preferably, the first portion 142 of the base 11 and the second portion 144 of the base 12 can hold or even clamp the first workpiece 61. Preferably, in the present embodiment, the clamping device 20 of the holding device 1 clamps the

basic bodies

11, 12 together after the

basic bodies

11, 12 are fitted together, so that the holding device 1 cannot be moved relative to the first workpiece 61 to adapt to different welding positions or heights of the second workpiece 62, wherein the holding aperture 140 also has a sizing effect. It is envisaged that the present holding device may also be moved relative to the workpiece after assembly. At this time, the gas discharge hole 132 is located in the vicinity of the back side of the welded portion a, so that the shielding gas is supplied to the back side of the welded portion a in use. Note that the exhaust holes 132 may be arbitrarily arranged depending on the position of the welded portion a.

Fig. 11 shows a perspective view of the holding device 1, wherein the holding device 1 is assembled with the first workpiece 61, while the second workpiece 62 is hidden. As can be seen in fig. 11, a groove 134 is provided around the vent hole 132. Due to the existence of the groove 134, the shielding gas ejected from the gas exhaust hole 132 does not directly encounter the second workpiece 62 and rapidly diffuses, but is concentrated in the groove 134, so that a uniform shielding gas layer is formed around the back side of the welding portion a, and a better shielding effect is achieved.

In other embodiments, the groove 134 may not be formed. Alternatively, the body 10 of the holding fixture 1 may not be in contact with the second workpiece 62 by means of the holding member 40 or the like, but a gap may be formed between the body 10 and the second workpiece 62, which may also form a shielding gas enrichment region, thereby improving welding quality and aesthetics.

Fig. 12 shows a front view of the holding device 1 assembled with the second work piece 62 and the first work piece 61, wherein the holding device 1 further comprises a height adjustment device 70, for example a height pin. As shown in fig. 12, in the present embodiment, the height adjusting means 70 protrudes from the surface of the

base bodies

11, 12 on the side facing away from the welding operation to support the

base bodies

11, 12 on the base plate 60, and the height of the height adjusting means 70 is adjustable to accommodate different welding heights or positions of the second workpiece 62 relative to the base plate 60.

Preferably, in some embodiments, after the two

bases

11 and 12 of the holding device 1 are clamped by the clamping device 20, the holding device 1 secures itself firmly with the first workpiece 61 so that the holding device 1 does not come into contact with the base plate 60 or any supporting structure to accommodate different welding heights or positions of the second workpiece 62.

The above-described holding device for welding is only one embodiment of the present invention, and on one hand, can supply the shielding gas to the welding portion, particularly the back side of the welding portion, to prevent the welding portion, particularly the back side of the welding portion, from being oxidized, thereby ensuring the welding quality and the appearance; on the other hand, the holding device has the advantages of simple operation and quick installation.

By using a two-piece base, two or more workpieces that need to be welded together can be more easily held or clamped together.

In general, protective gas can be supplied simultaneously during welding, and for thin-wall parts, oxidation is easy to occur on the back surface, so that the supply of the protective gas to the back surface is important, and the holding device provides a good back surface protection measure for the welding of the thin-wall tubular part and the thin plate.

Although various embodiments of the present invention have been described in detail herein, it is to be understood that this invention is not limited to the particular embodiments described and illustrated in detail herein, and that other variations and modifications may be effected by one skilled in the art without departing from the true spirit and scope of the invention. All such variations and modifications are intended to be within the scope of the present invention.

List of reference numerals

1 holding device

10 main body

11 first substrate

12 second substrate

15 alignment pin

16 aligned holes

20 clamping mechanism

30 air inlet joint

40 holder

60 base plate

61 first workpiece

62 second workpiece

64 orifice

70 height adjusting device

80 fastener

130 cover plate

132 vent hole

134 groove

140 holding orifice

142 first part

144 second part

150 concave table

162 shield gas channel

162A first channel portion

162B second channel portion

164 air intake passage

166 thin wall

170 sealing member

172 cut

Claims

1. A holding device (1) for welding, the holding device (1) comprising:

a body (10), said body (10) comprising a holding aperture (140) configured for holding at least one tubular workpiece (61), said at least one tubular workpiece (61) being to be welded to at least another workpiece (62), said at least another workpiece (62) resting on a surface of said body (10), said at least another workpiece being formed with an aperture (64) cooperating with said at least one tubular workpiece (61) so that said at least one tubular workpiece (61) can pass through said aperture (64); and

-a height adjustment device (70), said height adjustment device (70) being adapted to adjust the height of the holding device (1) to the welding position between the at least one tubular workpiece (61) and the at least one further workpiece (62);

wherein a shielding gas passage (162) for flowing a shielding gas for welding is provided in the body (10), the shielding gas passage (162) is opened toward a welding operation side in the vicinity of the holding hole (140),

the holding device (1) further comprising a cover plate (130) covering the shielding gas channel (162), the cover plate (130) having an evenly distributed venting hole (132), the venting hole (132) being in fluid communication with the shielding gas channel (162),

the holding device (1) further comprising a sealing member (170) between the body (10) and the cover plate (130), wherein the sealing member (170) has a cut-out (172) for passage of a protective gas,

wherein the body (10) is provided with a recessed land (150) around the retention aperture (140), the cover plate (130) and the sealing member (170) being seated within the recessed land (150) flush with the surface of the body (10).

2. The holding device (1) according to claim 1, wherein the shielding gas channel (162) extends partially or completely around the circumference of the holding aperture (140).

3. The holding device (1) according to claim 1, wherein the body (10) is provided with an inlet channel (164) in fluid communication with the shielding gas channel (162).

4. Holding device (1) according to claim 3, wherein the air inlet channel (164) is provided with an air inlet connection (30) to an external protective gas source.

5. The holding device (1) according to any one of claims 1 to 4, wherein the cross-sectional shape of the holding aperture (140) comprises at least one of a circular, oval, square, T-shaped and L-shaped shape.

6. The holding device (1) according to claim 1, wherein the cover plate (130) is formed with a groove (134) around the venting hole (132) such that a protective gas enrichment zone is formed within the groove (134).

7. The holding device (1) according to any one of claims 1 to 4 and 6, wherein the body (10) comprises a first base body (11) and a second base body (12), the first base body (11) being provided with a first portion (142) of the holding aperture (140), the second base body (12) being provided with a second portion (144) of the holding aperture (140), the first portion (142) and the second portion (144) cooperating to form the holding aperture (140).

8. The holding device (1) according to any one of claims 1 to 4 and 6, wherein the at least one tubular workpiece (61) is clamped by the holding aperture (140) and the at least one further workpiece (62) is a plate-like piece.

9. The holding device (1) according to claim 8, wherein the holding device (1) is provided with at least one holder (40) for holding the at least one further workpiece (62) against a surface of the body (10).

10. The holding device (1) according to claim 7, wherein the first base body (11) is provided with a first channel portion (162A) of at least one shielding gas channel (162), the second base body (12) is provided with a second channel portion (162B) of the at least one shielding gas channel (162), the first channel portion (162A) and the second channel portion (162B) being in fluid communication at a surface where the first base body (11) and the second base body (12) are joined to each other.

11. The holding device (1) according to claim 10, wherein the first channel portion (162A) and the second channel portion (162B) of the at least one shielding gas channel (162) extend 90 ° around the periphery of the first portion (142) and the second portion (144), respectively, of the holding aperture (140).

12. The holding device (1) according to claim 7, wherein the first base body (11) and the second base body (12) are clamped together by a clamping mechanism (20).

13. The holding device (1) according to claim 7, wherein one of the first and second substrates (11, 12) is provided with an alignment pin (15), and the other of the first and second substrates (11, 12) is provided with an alignment hole (16) into which the alignment pin (15) is inserted.