REFLECTION INNER RING

Abstract

A device for end-side welding of plastic profiles, preferably pipes, containing tensioning devices for retaining the plastic profiles in a coaxial position in relation to one another, a heating plate for generating heat rays for contact-free heating up of the plastic profile ends and a reflection outer ring for reflection of the heat radiation onto the plastic profile outer side, wherein a reflection inner ring is arranged on the heating plate, wherein the reflection inner ring reflects the heat rays of the heating plate onto the plastic profile inner side.

Claims

1. A device (1) for end-side welding of plastic profiles (6), preferably pipes, containing tensioning devices (2) for retaining the plastic profiles (6) in a coaxial position in relation to one another, a heating plate (3) for generating heat rays for contact-free heating up of the plastic profile ends (6) and a reflection outer ring (4) for reflection of the heat radiation onto the plastic profile outer side, wherein a reflection inner ring (5) is arranged on the heating plate (3), wherein the reflection inner ring (5) reflects the heat rays (13) of the heating plate (3) onto the plastic profile inner side.

2. The device (1) according to claim 1, wherein the heating plate (3) has a through-hole (9) in the centre, wherein the heating plate (3) preferably has a round outer contour.

3. The device (1) according to claim 2, wherein the reflection inner ring (5) is arranged concentrically in the through-hole (9) of the heating plate (3).

4. The device (1) according to claim 1, wherein the reflection inner ring (5) is formed to have a changeable length.

5. The device (1) according to claim 1, wherein the reflection inner ring (5) is capable of conducting heat.

6. The device (1) according to claim 1, wherein the reflection inner ring (5) has a maximum roughness Ra 1.2 μm.

7. The device (1) according to claim 1, wherein the reflection inner ring (5) has two bushings (10).

8. The device (1) according to claim 1, wherein the reflection inner ring (5) has tensioning elements (12).

9. The device (1) according to claim 5, wherein the bushings (10) of the reflection inner ring (5) are connected to one another with a changeable length by means of bolts (11) and tensioning elements (12).

10. A heating plate (3) for generating heat rays for contact-free heating up of the plastic profiles (6), preferably pipes in a device for end-side welding, wherein a reflection inner ring (5) is arranged on the heating plate (3), wherein the reflection inner ring (5) reflects the heat rays (13) of the heating plate (3) onto the plastic profile inner side.

11. The heating plate (3) according to claim 10, wherein the heating plate (3) has a through-hole (9) in the centre.

12. The heating plate (3) according to claim 10, wherein the reflection inner ring (5) is arranged concentrically in the through-hole (9) of the heating plate (3).

Description

DRAWINGS

[0024] An exemplary embodiment of the invention will be described on the basis of the figures, wherein the invention is not only restricted to the exemplary embodiment. In the figures:

[0025] FIG. 1 shows a schematic view of a device according to the invention,

[0026] FIG. 2 shows a partial view through the heating plate with reflection inner ring and a clamped plastic profile end and

[0027] FIG. 3 shows a three-dimensional view of a heating plate with reflection inner ring.

DETAILED DESCRIPTION

[0028] FIG. 1 shows a schematic view of a device 1 according to the invention for end-side welding of plastic profiles 6, preferably pipes, wherein the heating of plastic profile ends 6 is carried out in a contact-free manner.

[0029] Device 1 contains tensioning devices 2 which are arranged coaxially to one another. Tensioning devices 2 serves as a retaining device for plastic profiles 6. Tensioning devices 2 are preferably arranged on a base plate 7, wherein at least one of tensioning devices 2 can be displaced linearly to join together plastic profiles 6.

[0030] A heating plate 3 which serves to heat plastic profile ends 6 is arranged between tensioning devices 2. In order to heat heating plate 3, heat cartridges (not plotted) are arranged in heating cartridge holes 8, provided for this purpose, in heating plate 3, this being apparent from FIGS. 2 and 3.

[0031] In order to be able to cover a welded joint in a wide range of dimensions of plastic profiles with the same device 1, heating plate 3 preferably has a round shape, i.e. it is advantageous in terms of the arrangement of the heating cartridges and even heating if the heating plate is formed as a round disc. The heating cartridges preferably extend radially in heating cartridge holes 8 in heating plate 3, which enables a regular and star-shaped arrangement.

[0032] Device 1 furthermore has a reflection outer ring 4 which is arranged around heating plate 3, preferably concentrically. Reflection outer ring 4 is wider than heating plate 3 and projects in each case beyond both sides of heating plate 3. This enables the reflection of heat or IR rays of heating plate 3. This means that heat or IR rays 13 proceeding from heating plate 3 which strike the inner surface of reflection outer ring 4 are reflected there and projected onto the lateral outer surface of plastic profile 6, as a result of which plastic profile 6 or tube is also heated up from the outside. In order to optimize heating of plastic profile 6 by virtue of the fact that as even as possible heating takes place, heat rays or IR rays 13 are also projected onto the plastic profile inner side. This is achieved by reflection inner ring 5. Reflection inner ring 5 is arranged on heating plate 3 and reflects the heat rays or IR rays onto the inner lateral surface of plastic profile 6.

[0033] As a result of the production method of heating plate 3, heating plate 3 has a through-hole 9 in the centre. This serves primarily to attach radially running holes 8 for the heating cartridges. Holes 8 for the heating cartridges are preferably bored and subsequently countersunk, this not always being possible in the case of heating plates 3 which have larger dimensions, which is why a through-hole 9 which enables the escape of chips during boring and countersinking is arranged in the centre of heating plate 3.

[0034] Reflection inner ring 5 is arranged in through-hole 9 of heating plate 3, this having the advantage that through-hole 9 is closed and an air circulation which would discharge the heat can be prevented. Reflection inner ring 5 arranged concentrically in heating plate 3 preferably contains two bushings 10, wherein bushings 10 are preferably formed to be identical. Bushings 10 of reflection inner ring 5 are arranged in mirror symmetry to one another, as a result they can be optimally inserted into through-hole 9. Bushings 10 are preferably mounted on a bolt 11 which can be formed, for example, as a simple screw with nuts. In order to be able to accommodate the change in width of heating plate 3 as a result of its temperature changes, reflection inner ring 5 has tensioning elements 12 which make it possible for reflection inner ring 5 to change length and nevertheless still ensure that reflection inner ring 5 is arranged in a rotationally secured manner and without play in through-hole 9.

[0035] This means that heating plate 3 is heated and correspondingly expands in terms of the width or thickness, it pulls apart the two bushings 10 mounted on bolt 11, counter to the force of tensioning elements 12. If heating plate 3 cools again, if it also contracts in terms of its width and bushings 10 are thus also pushed together again, tensioning elements 12 push these together. It is thus ensured that reflection inner ring 5 behaves in accordance with the change in width of heating plate 3 and is guided in through-hole 9.

[0036] In FIG. 2, heat or IR rays 13 are represented by arrows which represent the reflection on the outer ring or on the outer lateral surface of reflection inner ring 5. Heat radiation 13 proceeding from heating plate 3 is reflected on reflection inner ring 5 and projected onto the inner lateral surface of plastic profile 6 or of the pipe. Plastic profile ends 6 are, as a result of the present invention, heated with heat rays or IR rays 13 which strike profile end 6 at the end side as well as via rays which heat the inner and outer lateral surface of plastic profile 6 as a result of the reflection on inner and outer reflection ring 4, 5. This produces even heating of profile end 6 which in turn produces a good bead and correspondingly a good welded joint.

LIST OF REFERENCE NUMBERS

[0037] 1 Device

[0038] 2 Tensioning device

[0039] 3 Heating plate

[0040] 4 Reflection outer ring

[0041] 5 Reflection inner ring

[0042] 6 Plastic profile/pipe

[0043] 7 Base plate

[0044] 8 Hole for heating cartridge

[0045] 9 Through-hole

[0046] 10 Bushing

[0047] 11 Bolt

[0048] 12 Tensioning element

[0049] 13 Heat or IR rays