JPH0513759B2 - - Google Patents

Description

[Detailed Description of the Invention] [Industrial Application Field] The present invention is a centering and clamping device for pipe-like workpieces to be welded together, which is equipped with an inert gas supply system on both sides of the welding part, and has a a first clamping unit having one clamping means and a second clamping unit having at least two clamping means, the clamping means having a wedge-shaped clamping groove opening outward; Each of the clamp grooves accommodates a row of clamp members, and the wall surfaces of the clamp grooves are formed of annular members that are movable in the axial direction relative to each other, and the annular member located at the outermost side of the annular members is The innermost annular member and The present invention relates to a device in which the welding part is arranged on the holding part in such a way that it can be displaced in the longitudinal direction.

The above-mentioned pipe-shaped workpiece means a pipe member, an elbow, a flange, and, in a broader sense, any workpiece that has an internal diameter portion that can be aligned and tightened by a clamping device.

PRIOR ART Clamping devices of the type described above are well known (see, for example, German Utility Model No. 85.07555 and German Utility Model No. 85.25952). They are designed as elongated bodies inserted into pipe-like workpieces that are welded together. A welding location called a so-called welding portion is provided with an annular recess into which an inert gas supply orifice opens. A clamp unit having two clamping means is arranged on one side of the welding part, and a clamping unit having only one clamping means is arranged on the other side, and the row of clamping members of each clamping means is arranged with an annular coil spring. It is formed.

For clamping straight pipe sections, a clamping unit is used which has two clamping means arranged in series to ensure exact alignment. For clamping short pipe parts such as elbows or flanges, clamping units with only one clamping means are used.

[Problem to be solved by the invention] To be able to obtain all combinations, at least three types of devices are required. That is, a device with two clamping units each having two clamping means for welding straight pipe parts, and a clamping unit with only one clamping means so as to be able to tighten the elbow. a device placed adjacent to the free end and for tightening the flange;
A device is required in which the clamping unit with only one clamping means is located at a distance from the free end of the device, far from the weld, and a stop is provided for positioning and centering the flange.

Since these are sophisticated instruments, it is very costly to stock at least three different devices for each nominal caliber.

[Object of the Invention] Therefore, it is an object of the present invention to reduce the cost of equipment necessary for the above three main uses.

[Means for solving the problem] In the solution according to the invention, at least the inner annular member and the welding part can change their respective positions on the piston rod and the holding part as follows. That is, in the first assembled state,
A weld is located near the free end of the device, and the first clamping unit is located between the free end of the device and the weld. In the second assembled state, the weld is located far from the free end of the device, and the second clamping unit is located between the free end of the device and the weld.

More specifically, the present invention is a centering and clamping device for pipe-like workpieces that is used by being inserted inside pipe-like workpieces to be welded together,
An inert gas supply system is provided on both sides of the weld, and a first clamping unit having at least one clamping means and a second clamping unit having at least two clamping means are provided. The clamp means includes a wedge-shaped clamp groove that opens outward, and each of the clamp grooves accommodates clamp members arranged in a row in the axial direction. The wall surfaces of the clamp grooves are formed by annular members 17, 18, 19, 20 that are movable in the axial direction relative to each other. The outermost annular members among the annular members can approach each other against the biasing force of the spring, and can be loosened by the biasing force of the spring. An inner annular member and weld 16 is disposed on the holding parts 11, 13 with an inner diameter slightly larger than the outer diameter of the holding parts 11, 13.

In order to be able to use the device for different purposes, the inner annular member and the weld can change their positions on the piston rod and the retaining part, respectively, as follows: . That is, in the first assembled state, the weld is located near the free end of the device, and the first clamping unit is located between the free end of the device and the weld. In the second assembled state, the weld is located far from the free end of the device, and the second clamping unit is located between the free end of the device and the weld. If a total of four clamping means are provided, a third assembly state can exist with two clamping units each having two clamping means.

ADVANTAGES OF THE INVENTION Since the positions of the parts directly forming the clamping unit can be changed, one and the same device can be used for all practical purposes by changing the assembly state. Labor costs for changeovers are relatively low, as all drive components remain unchanged. It is only necessary to remove the fixing member at the end of the device and, after converting the member, to retighten said fixing member. The overall cost in terms of equipment costs and inventory costs is reduced by about 1/3 as a result.

A total of four clamping means are provided, so that in the third assembled state the two clamping units can each be equipped with two clamping means for clamping a straight pipe member. In the first and second assembled states, the first clamping unit comprises only one clamping means and the second clamping unit comprises three clamping means. At the same time, the clamping member of the third clamping means of the second clamping unit can be removed, so that
In reality, only the remaining two clamping means are effective. If the device is shortened, the clamping means should be
It would also be possible to provide only one. However, in general, shortening the device during assembly and conversion
This is more complicated than installing a second clamping unit with a third clamping means.

Preferably, the weld as well as the annular member forming the wall of the groove are arranged on the holding part in such a way that they can be removed and their position changed. In this case, if desired, the latter can be fixedly mounted on the drive or on the piston rod. However, since it is inconvenient to supply inert gas to the welding part using a simple method, generally the welding part is fixedly attached to a holding part, and the position of the holding part as a whole can be changed. It is more preferable to design.

In order to supply inert gas in a simple way to the welds which are arranged in different axial positions depending on the assembly state, it is preferable that in all assembly states the holding part is connected to the weld on the one hand and to the weld on the other hand. The piston rod encloses an elongated inert gas supply space that communicates with an inert gas supply orifice provided in the piston rod.

The holding part is composed of two holding members, the first holding member holding the welded part and forming a gas supply space having a length at least about half of the distance between the two outermost annular members. However, it is convenient if the gas supply orifice is located approximately in the center of the two annular members, while the second holding member can be mounted on one side or the other side of the first holding member, respectively. In this case, the welds can be located either at the two outermost ends (first and second assembled states) or in the middle (third assembled state). The two holding elements can be connected in any suitable manner, for example by suitable mating surfaces or by a threaded connection, in order to form a centered guide surface. However, if they are both coaxial with respect to the piston rod, no direct connection as described above is necessary.

The biasing means for returning the annular member to the released position after the clamping action caused by the drive are formed by one or more springs seated on the piston rod. As a result, these also
can remain unchanged, and the end face of the holding part and the end face of the piston rod or the face facing the part connected to the drive part suitably surround a spring space which has the same length in all assembled states. . Preferably, however, the biasing means are formed solely by an annular spring provided with a row of clamping members or by forming a row of clamping members. The spring surrounding the piston rod can be partially or completely eliminated, simplifying its construction and use.

In particular, it is preferred that the spring force of one clamping unit be greater than that of the other, either as a result of additional internal springs or different spring forces inherent in the clamping means. This means that in clamping units with a lower spring force opposing a lower resistance to the clamping actuation, the row of clamping members is placed in front of the clamping members of the other clamping units on the inner surface of the combined workpiece. This ensures that the workpiece is pressed outwardly against the workpiece, so that the workpiece is secured before the other workpieces. This facilitates mutual alignment. If the biasing means is formed solely by the clamping means, annular springs with different spring constants are preferably used. Alternatively, it would be possible to provide the clamping grooves with different wedge angles. However, it is more preferable that the clamp grooves have basically the same shape.

If a total of four clamping means are provided,
Two relatively weak springs and two relatively strong springs are provided, such that in the first and second assembled states, the first clamping unit is fitted with a relatively strong spring, and in the third assembled state, each clamping unit is fitted with two relatively strong springs. Two identical springs are each installed.

In order to effectively cool the device, in particular its parts adjacent to the welds, according to the invention it is generally sufficient to cool the piston rod with a closed cooling duct, the cooling effect being on the one hand As a result of heat conduction and radiation, on the other hand, it is transferred from the piston rod to the parts adjacent to the weld by transport by inert gas.

[Example] Hereinafter, the present invention will be described in detail with reference to the drawings showing preferred embodiments of the present invention. Here, 3
The two drawings show longitudinal sections of the same embodiment of the device according to the invention in different assembled states.

The drive unit 1 of the device includes a cylinder 2 whose inner end is closed with a wall 3. The cylinder 2
houses a piston 4 and a piston rod 6 which are fixed to a connecting portion 5. Said connection 5 is used to connect supply hoses, in particular compressed gas supply hoses for inert gas, for the introduction and discharge of cooling water, and for actuating the piston/cylinder arrangement. The inert gas is conveyed through line 7 to an inert gas outlet orifice 8, while the cooling water flows through line 9 into the vicinity of the closed end of piston rod 6 and thereafter flows back through piston rod 6. A piston rod gland 10 is attached to the cylinder wall 3.

A first holding element consisting of a cylindrical sleeve 11 and an end disk 12 is coaxially guided by the piston rod 6. A second holding member consisting of a sleeve 13 and a disk 14 is joined to the first holding member. The outer diameters of both sleeves 11 and 13 are approximately equal to the outer diameter of the extension 15 of the cylinder wall 3.

The sleeve 11 has a welded portion formed therein, and an annular member 16 corresponding to the sleeve 11 provided with a plurality of through holes for supplying inert gas.
is fixed. On the side of the annular member 16,
A replaceable annular member 17 is provided. Further, a sleeve-shaped annular member 18 and an annular member 19 supported by the elongated portion 15 of the drive portion 1 are arranged coaxially with the elongated portion 15. A dish-shaped annular member 20 is removably attached to the free end of the piston rod 6 by means of an easily removable fixing member 21, for example a threaded nut or key. All annular members have an inner diameter that is slightly larger than the outer diameter of the sleeves 11, 13 and the extension 15. They have conical end faces facing each other forming a clamping groove 22 in which coil springs are arranged as clamping members in series, in particular a relatively weak coil spring 23 and a relatively strong coil spring 23. 24 are arranged.

To tighten the device, a pressure medium is introduced into the cylindrical space between the piston 4 and the cylinder wall 3, so that the piston rod 6 is pulled to the right in the figure and the outer annular members 19 and 20 are brought closer together. As a result, the end surfaces of the clamp grooves 22 also approach each other, and the coil springs 23,
24 is pressed outwardly towards the inner surface of the workpiece to be clamped. As a result, each clamp groove 22 has a coil spring 23 located within the groove 22,
Together with 24, they form a clamping means. Up to this point, all assembly states shown in the figures correspond to one another.

In the first assembled state shown in FIG.
6 is located near the free end of the device. The first clamping unit 25 has only one clamping means with a strong spring 24, while the second clamping unit 26 has three clamping means, the outer two of these having weak springs 23. However, the inner one is equipped with a strong spring 24. The first holding portions 11, 12 are located near the free end of the device, and the welding portion 16 is similarly located near the free end of the device.

The inert gas supply space 27 again reaches the gas supply orifice 8 in this case. This is because the right disk 12 and the outermost annular member 2
0 is somewhat larger than half the distance between the two outermost annular members 19 and 20, and the gas supply orifice 8 is located midway therebetween.

Weak spring 23 of clamp unit 26
This ensures that the straight pipe member to be clamped is initially secured with a gentle force if the piston/cylinder arrangement is initially subjected to only a slight pressure. The clamping elbow of the clamping unit 25 can then be aligned with the pipe member and the position of the pipe member relative to the weld 16 of the device can be checked. The piston/cylinder arrangement is then subjected to full pressure and the two workpieces are clamped together with a predetermined force. After welding, when the drive is stopped and the annular members 18, 19, 20 move axially away from each other, the springs 23, 24 are compressed again and the device is again separated from the workpiece.

According to FIG. 2, in the second assembled state, the holding parts 11 and 13 and the annular member 18 with respect to the welded part 16 are
The arrangement is opposite to the first assembled state. In order to fix and align the flange to be tightened by the first clamp unit, the stop flange 28 is attached to the drive part 1.
The clamp unit 26, on the other hand, is used for clamping straight pipe members.

A relatively strong spring 24 is connected to the first clamp unit 2.
5, a relatively weak spring 23 is arranged in the second clamping unit 26, the latter being loaded first of all when the clamping operation begins, so that before the final tightening the relative position can be checked and the flange can be aligned on the first clamp unit 25. If the flange is to be tightened first and then to the pipe member, the first
The clamp unit 25 must be equipped with a weak spring, and the clamp unit 26 must be attached independently with a strong spring.

Although the weld 16 is at a very large distance from the free end of the piston rod 6, it can also be supplied with inert gas from the supply orifice 8. This is because the distance between the annular member 19 and the gas supply orifice 8 is such that the distance between the annular member 19 and the left terminal disk 1 is
This is because it is smaller than the distance from 2.

In the first and second assembled states, the second holding part 1
3 and 14 were arranged on the side of the first holding parts 11 and 12 on the side away from the welding part 16, but according to FIG. 1 adjacent to the end of the holding part. the result,
The weld 16 is located in the center of the annular members 19, 20, and it does not matter which of the two retainers is closer to the free end of the device.

In the above assembled state, two clamp units 2
5 and 26 are each equipped with two clamping devices,
One of the two clamping devices is fitted with a relatively weak coil spring and the other with a relatively strong coil spring.

In the above device, the fixing member 21 is removed, the holding part is
1 by pulling out the annular member and spring and reinstalling them in the desired configuration.
It can be easily changed from one assembly state to another.

[Brief explanation of the drawing]

The drawings show different assembled states of the same embodiment of the device for centering and clamping pipe-like workpieces to be welded together according to the present invention, and FIG. 1 shows the device in the first assembled state. FIG. 2 is a vertical cross-sectional view of the device in a second assembled state, and FIG. 3 is a vertical cross-sectional view of the device in a third assembled state. 1... Drive unit, 6... Pull rod (piston rod), 8... Inert gas supply orifice, 11,
13... Holding part, 16... Welding part, 17, 18,
19, 20... annular member, 22... clamp groove,
23, 24...clamp member (annular spring), 25
...first clamp unit, 26...second clamp unit, 27...inert gas supply space.

Claims (1)

[Claims] 1. A centering and clamping device for pipe-like workpieces that is used by being inserted inside pipe-like workpieces to be welded together, comprising: an inert gas supply system on both sides of the welding part 16; , a first clamping unit 25 having at least one clamping means and a second clamping unit 2 having at least two clamping means.
6, the clamping means is provided with a clamping groove 22 formed in a wedge shape and opening outward, and each of the clamping grooves accommodates clamp members 23 and 24 arranged in a row in the axial direction, The wall surfaces of the clamp grooves are formed by annular members 17, 18, 19, and 20 that are movable in the axial direction relative to each other, and the annular members 19 and 20 located at the outermost side of the annular members are adapted to the biasing force of the spring. Via the pull rod 6 and the drive part 1, by being able to approach and loosen each other against
While removably connected to each other, the innermost annular members 17 and 18 and the welded portion 16 have an inner diameter slightly larger than the outer diameter of the holding parts 11 and 13. 13, and in the first assembled state (see FIG. 1), the welded portion 16
is arranged near the free end of the device, and a first clamping unit 25 is located between the free end of the device and the weld 16, and in the second assembled state (see FIG. 2) the weld 16 at least the inner annular members 17, 18 are arranged far from the free end of the device and the second clamping unit 26 is located between the free end of the device and the weld 16.
A device for centering and clamping pipe-like workpieces to be welded together, characterized in that the welding part 16 can change its position on the piston rod 6 and the holding parts 11, 13, respectively. 2 Total of four clamping means 22, 23; 2
2, 24, and the second clamping unit 26 is provided with three clamping means in the first and second assembled states.
Apparatus described in section. 3 In the third assembled state (see Figure 3), 2
3. Device according to claim 2, characterized in that each of the two clamping units (25, 26) is provided with two clamping means. 4. The device according to any one of claims 1 to 3, characterized in that the welded part 16 is fixedly arranged on the holding part 11 whose position can be changed. 5. The holding part 11 is characterized in that in all assembled states it includes an elongated inert gas supply space 27 which communicates with the welding part 16 and with the inert gas supply orifice 8 provided in the piston rod 6. The device according to claim 4. 6 The above-mentioned holding part consists of two holding members 11 and 13, and the first holding member 11 includes a welded part 16 and annular members 19 and 2 located at the outermost side.
forming a gas supply space 27 having a length at least about half the distance between the gas supply orifices 8;
is located approximately at the center of the outermost annular members 19, 20, and the second holding member 13 can be selectively attached to one side or the other side of the first holding member 11. An apparatus according to claim 4 or 5. 7. Device according to claim 6, characterized in that the holding members 11, 13 can be connected to each other to form aligned guide surfaces. 8. The end face of the holding part and the end face of the member 3, 20 connected to the end of the piston rod or the drive part 1 and facing the above-mentioned holding part are connected by a spring having an equal length in all assembled states. The device according to any one of claims 1 to 7, characterized in that a space is formed. 9. Claims 1 to 8, characterized in that the biasing means is formed solely by an annular spring provided by the row of clamp members 23, 24.
Apparatus according to any one of paragraphs. 10. The device according to any one of claims 1 to 9, characterized in that the spring force of one clamp unit 22, 24 is greater than the spring force of the other clamp unit 22, 23. . 11. The device according to claim 10, wherein the annular springs 23 and 24 have different spring constants. 12. Device according to claim 10 or 11, characterized in that the clamping grooves 22 have essentially the same shape. 13. Device according to claim 10 or 11, characterized in that the clamping grooves have different wedge angles. 14 Equipped with two relatively weak springs 23 and two relatively strong springs 24, in the first and second assembled states, the relatively strong springs 24 are attached to the first clamp unit 25, and in the third assembled state, each unit 2
12. Device according to claim 11, characterized in that two identical springs 23 or 24 are attached to the springs 5, 26. 15. Apparatus according to any one of claims 1 to 14, characterized in that the pull rod houses a closed-ended cooling duct.