JP2549739B2 - Welding device for plastic tubular members - Google Patents

Description

Description: TECHNICAL FIELD The present invention relates to a welding device for a plastic tubular member, and more particularly to a welding device of the type described in the preamble of claim 1.

[Conventional technology]

As a welding device for tubular members, a welding device is known in which an annular groove is formed in the inner circumference of a heatable jaw and a vacuum is generated in the groove during or after the step of welding the tubular members axially butted together. is there. This vacuum condition makes it possible to prevent internal penetration of molten material and formation of internal beads during welding. However, it has been found that with this welding method or welding device, a welded joint with satisfactory strength and a smooth inner peripheral surface cannot be realized.

It is also known to arrange an elastic charge which presses the internal weld bead in order to reduce the internal weld bead on the inner peripheral surface of the tubular member (DE 28 30 72).
No. 2).

However, during welding, the opposed end faces of the tubular members that are pressed against the heating element and heated are brought into contact with each other. This method does not achieve a welded joint without beads at all, and since the inside of the tubular member is contaminated by heating the front end face of the tubular member, the joint part of the piping system suitable for conveying the high-purity medium is connected. It is not possible to achieve the required cleanliness in.

DE 29 23 205 A1 discloses a welding device having the above-mentioned construction which makes it possible to weld the front end face of a plastic tubular member without a bead.

[Problems to be Solved by the Invention]

This known welding device can only be applied to tubular members of a particular pipe diameter. The heating device has a metal dish-shaped half, the central part of which serves as a butt joint can be electrically heated, and the other part has cooling chambers at both ends in the longitudinal direction. Such a structure is very disadvantageous since it is costly and needs to control each zone individually. Also,
Since the heating zone is not cooled in a short time to complete heating, welding takes a long time.

An object of the present invention is to enable a plastic tubular member to be firmly joined without a bead, to greatly simplify the structure, and to use it without any problem even in a place where a piping system suitable for carrying a high-purity medium is installed. The object is to propose a welding device having the above-mentioned configuration that can be used.

Furthermore, the welding device of the present invention realizes a short installation time, a short welding time and an always good weld joint,
It must be usable for welding tubular members of different tube diameters.

[Means for solving the problem]

The present invention solves the above problems by the features described in the latter part of claim 1.

〔Example〕

Furthermore, particularly advantageous embodiments of the invention are as described in the dependent claims.

 Hereinafter, the present invention will be described in detail with reference to the illustrated embodiments.

1 is a partial front view of a welding apparatus according to the present invention, FIG. 2 is a sectional view taken along line II-II of FIG. 1, FIG. 3 is a partial sectional view taken along line III-III of FIG. 4 is a partial cross-sectional view showing a modification of FIG. 2 in a plane intersecting with the heating device, and FIG. 5 is a cross-sectional view taken along the line VV of FIG.

FIG. 1 is a partial front view of a welding device according to the invention comprising a support frame 1, a heating device 2 and a tube fixing device 3, on the other side of the heating device 2 a further tube fixing device (not shown) is further provided. ing.

As shown in FIG. 2, a guide member 4 is provided on the support frame 1.
By disposing a and 4b, the pipe fixing device 3 can be displaced in the longitudinal direction on the guide member and can be firmly connected to the support frame 1 by the clamp device 5.

The heating device 2 is mounted on the guide members 4a, 4b and can be firmly fastened by the clamping device 5, in which case the pins 6 arranged in the support frame 1 are fitted into the corresponding recesses 7 of the heating device 3. Thus, the guide member 4 can be positioned in the longitudinal direction.

As shown in FIG. 2, the heating device 2 comprises a lower part 20 having a receiving member 21a having a semicircular cross-section that fits the tubular member 8 to be welded, and an upper part having a receiving member 21b having a corresponding cross-sectional shape. It consists of 22 and. The upper part 22 is a rotary joint 23
The open side is connected to the lower part 20 by means of the clamp device 24 and can be fixed by the clamp device 24 on the opposite side.

The clamping device 24 is provided with an eccentric disc 26 that can be rotated via a rotary knob 25, and the eccentric inner clamping surface 26 is provided.
Cooperate a with the fastening bolts 27 of the lower part 20. As shown in FIG. 3, in each of the receiving members 21a and 21b, a centrally arranged electric heating jaw 28 and holding jaws 29 on both sides thereof are provided.
And a side wall 30, which are fixed to the casing 20a of the lower part 20 and the casing 22a of the upper part 22, respectively.

A holding jaw 29 made of a material having low heat conductivity, such as stainless steel, is attached to the side wall 30 via a bolt 31 and a spacer 32.
And the heating jaws 28 are held fixed between the holding jaws 29. Each heating jaw 28 made of a material having a high heat conductivity, such as steel, is provided with an electric heating cartridge 33 or other electric heating device. A common groove 34 surrounding the heating jaw 28 and the holding jaw 29 is formed in the inner wall and the side wall 30 of the casings 20a, 22a, and cooling air that can be generated by the blower 9 is passed through the groove. The blower 9 is arranged directly below the heating device 2 arranged on the box-shaped support frame 1, and
It can be driven by the electric motor 10 (see FIGS. 1 and 2).
See figure).

A recess 35 is provided on the inner circumference of the side wall 30, which corresponds in shape and size to the bead provided on the tubular member 8 to be welded, which is formed as a pipe joint. As a result, the pipe joint is held at an appropriate position in the axial direction.

A unique heating device 2 can be mounted on the support frame according to each pipe diameter of the tubular member to be welded, and the mounting and heating device can support nominal pipe diameters of 16 mm, 20 mm, 25 mm, 32 mm, 40 mm, 50 mm and 65 mm. It is suitable to form. The heating devices 2 are arranged side by side in the longitudinal direction of the guide member 4, and a power switch 11 is provided on the support frame 1 corresponding to each heating device.

When the heating device 2 for a specific pipe diameter is mounted, the contact switch 11 associated with the heating device is operated by the pin 36 fixed to the heating device, and the program control device 12 is set according to the pipe diameter. Adjust heating program. The program controller 12 is arranged in the support frame 1 and is operatively connected to an operation panel (not shown) arranged on the front side.

Further, the support frame 1 has a support device 15 that can be expanded.
A small electric compressor 14 is provided for generating the compressed air required for the operation of the above (see FIG. 1). Support device
15 is formed as a bladder and is connected to the compressor via an air pipe 16. A pressure sensor 17 provided in the air pipe 16 is operatively connected to the program controller via a pressure regulator to ensure that the required regulating pressure can be maintained in the bladder during the welding process. The compressor automatically operates when the pressure drops.

Each pipe fixing device 3 is provided with an upper portion 41 which is openably and closably attached to a lower portion 40 by a rotary joint 23, and replaceable half-plate-shaped clamp jaws 42 are arranged in these portions.
Lower part of the clamp jaw 42 corresponding to the pipe diameter to be welded
40 and upper part 41 are inserted and fixed. Clamping device 2 for clamping the lower and upper parts 40, 41 together
4 has the same configuration as the clamp device for the heating device 2.

The electrothermal cartridges 33 of the heating device 2 each have a thermal sensor 37 and are operatively connected to the program control device 12.

Each contact switch 11
An associated adjusting element is provided for adjusting a predetermined heat supply for the.

The amount of heat supplied is determined by the integrated value of the measured temperature in the heating device over a predetermined time, and the integration starts from an adjustable temperature, for example 210 ° C.

4 and 5 show a modified example of the heating device 2. The heating device of this example can also be mounted on the support frame 1, and can be connected to the support frame 1 in a positioned state by the pin 51 and the clamp mechanism 50. A plug contact member 52 having a contact element 53 is arranged in the casing 20a of the lower portion 20.

The second plug contact member 54 having the contact element 55 corresponding to the contact element 53 is inserted into the plug contact member 52 while centering with the pin 51 after mounting the heating device 2. It is advantageous to provide a total of 15 contact elements 53, 55 on each plug contact member 52, 54, and to program four contact elements for both heating cartridges 33 and four contact elements for both thermal sensors 37, respectively. Combined with the control device 12, the remaining 7 contact elements are used to encode various heating devices 2 required for different pipe diameters, and the required welding program corresponding to each pipe diameter in the program control device 12 is selected and executed. It is possible. These plug contact members should be replaced with the contact switch 11 and the pin 36 described above with reference to FIGS. 1 to 3, and as a result, the welding apparatus can be simplified.

A holding member 60 is fixed to each of the lower portion 20 and the upper portion 22 of the heating device 2, and the heating jaws 62 can be arranged in a centered state in the recess 61 of each holding member.

The heating jaw 62, in the intermediate region 63 passing through the recess 64,
It is assumed that the receiving member 21 has a small wall thickness so that good heat transfer from the heating cartridge to the welding location is performed.

A heating element 65, which is preferably made of copper, is located in the recess 64, the heating element 62 being made of stainless steel.
And welded together. The heating cartridge 33 and the thermal sensor 37 are inserted and arranged in the heating member 65. The temperature transition is determined by the cross-sectional shape of the recess 64 in the intermediate region 63, a so-called heating zone. In this case, the both side regions 66 as the temperature adjustment zone are not heated strongly because of the large wall thickness D.

On the outer periphery of the support member 60, a recess 67 is formed as a groove 34 for passing the cooling air generated by the blower 9.

A recess for accommodating the heating member 65 on the inner periphery of the support member 60
A central portion 68 is provided, through which cooling air is likewise passed to rapidly cool the heating element 65 and the weld joint. The remaining structure of the welding apparatus according to this example is similar to that described above with reference to FIGS.

[Action]

 Welding work is performed as follows.

Depending on the pipe diameter of the pipe or joint to be welded, the corresponding heating device 2 is attached to the guide member 4 and the corresponding clamp jaw 42 is attached to the pipe fixing device 3.

The tube or fitting is placed in the heating device, and in the case of the tube, ultimately in the tube fixing device, by clamping the upper part 22, 41 to the lower part 20, 40 by the clamping device 24. Clamp tightly by.

When the heating device 2 is attached, the corresponding welding parameters are set by the operation of the corresponding power switch 11 or the contact element.
Adjusted automatically by 53,55. When installing pipes or fittings, place the bladder 15 in the internal space of the welded joint area.
To place. When the start key is pressed in this state, the following operation is automatically started: 1. The bladder is pressurized by the operation of the compressor.

2. Heating is started and the maximum controlled temperature (200-300 ° C) is reached quickly without overshoot. The required heating energy per unit size is set before welding. The integration of heating energy starts at about 210 ° C.

3. Stop heating after reaching adjusted heating energy.

4. Operate the blower for cooling air until an adjustable temperature of approx. 90 ° C is reached.

5. Stop the supply of cooling air. At the same time the bladder pressure is released.

6. Finish the welding process. Remove the welded pipe or fitting from the device and pull out the bladder.

The welding device goes into a standby state to realize the next welding connection.

 ─────────────────────────────────────────────────── ─── Continuation of the front page (56) References JP-A-59-1213 (JP, A) JP-A-61-175022 (JP, A) JP-A-61-274920 (JP-A) JP-A-64- 4332 (JP, A) US Patent 4008118 (US, A)

Claims (11)

(57) [Claims] 1. A welding device for welding and joining a plastic tubular member, wherein the joining end portion of the tubular member is held so that the end faces aligned in the axial direction are in contact with each other, and the opening surrounds the tubular member. In the welding device, which can be heated by a possible heating device and which further comprises a supporting device arranged inside the tubular member, can be fixed in a positioning state on the supporting frame (1) according to each pipe diameter of the pipe to be welded. The heating device (2) is provided, and the electric contact elements (53, 55, 11) provided in each heating device (2) are set according to each pipe diameter when the heating device (2) is mounted on the support frame. Welding device capable of selecting the welding program of the programmed program control device (12). 2. The welding apparatus according to claim 1, wherein each welding program is set so that heating energy that can be changed is supplied over an adjustable time. 3. The welding device according to claim 1, wherein the heating device (2) is capable of electrically heating the jaws (28, 6).
A welding device, characterized in that 2) is surrounded by a common groove (34), which groove is operatively connected to a blower (9) for generating cooling air. 4. The welding device according to claim 3, wherein the fan (9) is arranged directly below the heating device (2) in the support frame (1). 5. The welding device according to claim 1, wherein the support frame (1) is provided with a longitudinal guide member (4), and the heating device is positioned on the guide member. A welding device, characterized in that it is fixable, and a pipe fixing device (3) having at least one releasable clamp jaw (42) can be clamped at a longitudinally adjustable position. 6. The welding apparatus according to any one of claims 1 to 5, wherein an electric compressor (14) for generating compressed air is arranged in the support frame (1). apparatus. 7. The welding device according to claim 6, wherein the compressor (14) is connected via an air pipe (16) to a support mechanism (15) formed as a bladder that can be expanded by compressed air. Characteristic welding equipment. 8. The welding device according to claim 1, wherein the heating jaw (28) can be heated by the electric heating cartridge (33) and is operatively connected to the program control device (12). Welding device characterized by having a heat sensor (37). 9. The welding device according to claim 1, wherein the electric contact element (53, 55) has a first plug contact member (54) provided on the support frame (1). When,
A welding device arranged on a second plug contact member (52) provided on each separate heating device (2). 10. The welding device according to claim 2, wherein a heating jaw (6) is provided to improve heat transfer.
The wall thickness of 2) is larger than that of the adjacent area on both sides (66) by the intermediate area (6
Welding equipment characterized by being thin in 3). 11. The welding device according to claim 10, wherein each heating jaw (62) is coupled with a copper heating member (65) having a heating cartridge (33) in an intermediate region (63),
A welding device characterized by being made of stainless steel.