DE102011010546B4 - Electric heater - Google Patents

Abstract

Electrical heating device (100,300,400), in particular for heating surfaces of objects (150,450) to be heated, with an inner lateral surface made of metal and at least one tubular coil cartridge or at least one tubular heating element (140,340,440,445), in which the inner lateral surface made of metal consists of at least two segments (101,102,301,302,401,402) is constructed, wherein each of the segments (101,102,301,302,401,402) is rigidly or movable, in particular foldable, connected or connectable to at least one adjacent segment (101,102,301,302,401,402) via at least one connecting element (103,108,109,110, 120,310,315,320,325), characterized in that a portion (141) of the coiled tubing cartridge or the tubular heating element (140) is guided in a gap between a first segment (101) and a second segment (102).

Description

The invention relates to an electrical heating device having the features of the preamble of patent claim 1.

Such heating devices are used, for example, to heat tools, machine parts and devices, in particular plastic injection nozzles. However, their application is not limited to this purpose.

Particularly popular embodiments of such heating devices are those with a cylindrical geometry. Previously, heating devices are known from the prior art, which are pushed onto the object to be heated from the front side. Such heaters disclose, for example, the DE 20 2008 013 626 U1 , the DE 20 2008 015 329 U1 , the EP 1 051 059 B1 and the U.S. 6,683,283 B2 .

When the "inner lateral surface" is mentioned in this application, it is always understood to be that which is in contact with the object to be heated; accordingly, an "outer surface" faces away from the object to be heated.

A disadvantage of the known heating devices is that they are not suitable for shapes of objects to be heated, the circumference of which decreases at least in sections when viewed from the front side or which have other dimensions that prevent the heating device from expanding over the extent of the object to be heated the object to be heated can be postponed so that an inner lateral surface of the heating device is nevertheless completely or almost completely in intimate contact with the surface of the object to be heated. But this is exactly what is absolutely necessary for good heat transfer.

More electric heaters are from DE 31 00 092 A1 and the CH 208911A known. In addition, the US 6,147,331A an electric heating device with the features of the preamble of patent claim 1.

The object of the invention is therefore to provide an electrical heating device which can be used for a greater variety of shapes of objects to be heated while avoiding poorly heated areas.

This object is achieved by an electrical heating device having the features of patent claim 1. Advantageous refinements of the invention can be found in the respective dependent claims.

The electrical heating device according to the invention has an inner lateral surface made of metal, in particular made of brass, and at least one coiled tubing cartridge or at least one tubular heating element. It is essential to the invention that the metal inner lateral surface is made up of at least two segments, each of the segments being rigidly or movable, in particular foldable, connected or connectable to at least one adjacent segment via at least one connecting element.

By dividing at least the inner lateral surface of the electrical heating device, i.e. the area which, when the electrical heating device is in contact with the object to be heated, into at least two segments, it is possible for the inner lateral surface to be heated not only by sliding it on, but also by to arrange a movement in a direction that is not parallel to the direction of extension of the component on the object to be heated. Specifically, for example, two separate segments in the form of half-shells can be placed on the sides of the object to be heated and then rigidly connected to one another with a connecting element, or two segments in the form of half-shells that are movably connected to one another by means of a hinge as a connecting element can be positioned laterally around the object to be heated be flipped around. Another advantage is that in the event of a malfunction, in many cases it is no longer the entire electrical heating device that has to be replaced, but only the affected segment, which leads to cost savings.

A particularly compact design is achieved when the segments have at least one groove into which the at least one coiled tubing cartridge or at least one tubular heating element is inserted.

An embodiment of the electrical heating device that is particularly well protected against environmental influences is achieved in that the segments have a closed cavity in which the at least one coiled tubing cartridge or the at least one tubular heating element is arranged. In addition to the surface that forms part of the inner lateral surface, such a segment also has wall surfaces and an outer surface section. Particularly good heat conduction properties of segments designed in this way are obtained when the cavity is completely or partially filled with a material, in particular with a powder or granulate.

Alternatively, the segments can also have at least one section of a winding body or carrier, on or in which the at least one coiled tubing cartridge or the at least one tubular heating element is arranged. This leads to an embodiment of the electrical heating device that is particularly easy to manufacture in terms of manufacturing technology.

In principle, it is also possible to combine individual segments designed according to the three different last-described embodiments with one another to form an electrical heating device.

If the segments, in addition to the inner lateral surface of the electrical heating device, also define an outer lateral surface of the electrical heating device which, when the segments are arranged on a component to be heated, is connected except for the seams between the segments, this leads to a very robust embodiment of the invention .

For good heat conduction, it is advantageous if the individual segments are fully or partially compressed.

In a particularly preferred embodiment of the invention, each of the segments is assigned at least one coiled tubing cartridge or at least one tubular heating element, so that each of the segments can be heated independently of the other segments.

In addition to greater flexibility and individual controllability with regard to the temperature distributions that can be achieved, each segment is then independent of the other segments and can therefore be exchanged particularly easily if it is affected by a defect.

A rigid connection between two segments is produced particularly easily if at least one of the connecting elements is a screw. This can simply be inserted through a hole in a first segment and screwed to a counter-thread introduced into the second segment.

A particularly simple embodiment of a movable connecting element is a hinge.

It is particularly advantageous if at least one clamping device is present, by means of which the segments can be clamped, in particular when the electrical heating device is arranged on a component to be heated. On the one hand, this ensures that the electrical heating device is seated securely, and on the other hand, this contributes to intimate contact with the component to be heated, which promotes heat transfer.

A particularly well reproducible temperature distribution can be ensured if the electrical heating device has at least one thermocouple or jacket thermometer.

This is advantageously accommodated in a bore or guide of at least one segment in order to protect it from external interference. The temperature distribution can be monitored and, if necessary, regulated particularly well if each segment has a thermocouple or mantle thermometer.

• 1a: Eine Darstellung eines Ausführungsbeispiels einer erfindungsgemäßen elektrischen Heizvorrichtung
• 1b: Eine dreidimensionale Darstellung des Ausführungsbeispiels aus 1a im auf ein zu beheizenden Objekt aufgebrachten Zustand,
• 1c: Eine zweidimensionale Seitenansicht der Anordnung aus 1b,
• 1d: Eine Querschnittsdarstellung durch die Anordnung aus 1c, geschnitten an der Linie A-A,
• 1e: Eine Querschnittsdarstellung durch die Darstellung aus 1c, geschnitten an der Linie B-B,
• 2a: Eine dreidimensionale Detaildarstellung eines aus Segmenten aufgebauten Innenmantels einer elektrischen Heizvorrichtung im auf ein zu beheizendes Objekt aufgebrachten Zustand.
• 2b: Eine Seitenansicht der Anordnung aus 2a,
• 2c: Die Anordnung aus 2a, gesehen von unten,
• 2d: Eine Querschnittsdarstellung durch die Anordnung aus 2c entlang der Linie A-A,
• 2e: Eine Querschnittsdarstellung durch die Anordnung aus 2c entlang der Linie B-B, wobei die Anordnung sich in aufgeklapptem Zustand befindet.
• 2f: Eine Querschnittsdarstellung durch die Anordnung aus 2c entlang der Linie C-C,
• 3a: Eine Darstellung einer anderen elektrischen Heizvorrichtung
• 3b: Eine dreidimensionale Darstellung der elektrischen Heizvorrichtung aus 3a im auf ein zu beheizenden Objekt aufgebrachten Zustand,
• 3c: Eine zweidimensionale Seitenansicht der Anordnung aus 3b,
• 3d: Eine Querschnittsdarstellung durch die Anordnung aus 3c, geschnitten an der Linie A-A,
• 3e: Eine Querschnittsdarstellung durch die Darstellung aus 3c, geschnitten an der Linie B-B,
• 4a: Eine Darstellung einer dritten elektrischen Heizvorrichtung
• 4b: Eine dreidimensionale Darstellung der elektrischen Heizvorrichtung aus 4a im auf ein zu beheizenden Objekt aufgebrachten Zustand,
• 4c: Eine zweidimensionale Seitenansicht der Anordnung aus 4b,
• 4d: Eine Querschnittsdarstellung durch die Anordnung aus 4c, geschnitten an der Linie A-A,und
• 4e: Eine Querschnittsdarstellung durch die Darstellung aus 4c, geschnitten an der Linie B-B,

The invention is explained in more detail below with reference to drawings. Show it:

• 1a : A representation of an embodiment of an electrical heating device according to the invention
• 1b : A three-dimensional representation of the embodiment of FIG 1a in the state applied to an object to be heated,
• 1c : A two-dimensional side view of the arrangement 1b ,
• 1d : A cross-sectional view through the assembly 1c , intersected at line AA,
• 1e : A cross-sectional representation through the representation 1c , cut at line BB,
• 2a : A three-dimensional detailed representation of an inner jacket made up of segments of an electrical heating device in the state applied to an object to be heated.
• 2 B : A side view of the assembly 2a ,
• 2c : The arrangement off 2a , seen from below,
• 2d : A cross-sectional view through the assembly 2c along line AA,
• 2e : A cross-sectional view through the assembly 2c along line BB with the assembly in the unfolded state.
• 2f : A cross-sectional view through the assembly 2c along line CC,
• 3a : An illustration of another electric heating device
• 3b : A three-dimensional representation of the electric heating device 3a in the state applied to an object to be heated,
• 3c : A two-dimensional side view of the arrangement 3b ,
• 3d : A cross-sectional view through the assembly 3c , intersected at line AA,
• 3e : A cross-sectional representation through the representation 3c , cut at line BB,
• 4a : An illustration of a third electric heater
• 4b : A three-dimensional representation of the electric heating device 4a in the state applied to an object to be heated,
• 4c : A two-dimensional side view of the arrangement 4b ,
• 4d : A cross-sectional view through the assembly 4c , cut at line AA,and
• 4e : A cross-sectional representation through the representation 4c , cut at line BB,

Identical reference symbols are used in all figures for the same components of the same exemplary embodiments.

1a shows an electrical heating device 100 with a first segment 101 and a second segment 102, which together form the inner lateral surface of the electrical heating device. The exact structure of the first segment 101 and the second segment 102 is den 2a until 2f refer to. It is of course also possible to use more than two segments.

2a and 2 B show the first segment 101 and the second segment 102 of the electrical heating device 100 in the state arranged on an object 150 to be heated. The object 150 to be heated is cylindrically symmetrical and has only one 2a visible channel 151 on. Sections 152, 153 are arranged at both ends of the object 150 to be heated, which have a larger radius than a central section 154 of the object and make it impossible to slide on an electric heating device.

The first segment 101 and the second segment 102 are connected to one another with a connecting element, which is embodied as a hinge 103 in a movable, in particular foldable, manner. Furthermore, a groove 104, 105 is introduced into the first segment 101 and into the second segment 102, each of which has a meandering configuration here.

2c shows the arrangement 2a , seen from below. As a result, only the second segment 102 with the groove 105 is visible from the electric heating device 100, which bears against the object 150 to be heated with the sections 152, 153 with a larger radius in the area of the middle section 154 and thus a part of the inner lateral surface of the electric heating device forms. In 2c you can also see that two additional rigid connecting elements between the second segment 102 and the in 2c not visible first segment 101 in the form of a first screw 110 and a second screw 120 are provided.

In the cross-sectional view of the 2d In addition to the central section 154 of the object 150 to be heated with channel 151, one can again see the first segment 101 with a groove 104 and the second segment 102 with a groove 105. The first segment 101 and the second segment 102 are connected to a hinge 103, of which 2d only one pin 131 can be seen, movably connected to one another. On the side of the channel 151 opposite the hinge 103 or its pin 131, the screw 110 is arranged as a second, rigid connecting element. The screw 110 engages with its thread (not shown) in a counter-thread 111 cut into or inserted into the first segment 101 . The second segment 102 is penetrated by a hole 112 for receiving the screw 110, which has a concentrically extending enlarged portion 113 for receiving the screw head.

The cross-sectional view of the 2e differs from the cross-sectional representation of the 2d not only by the different place where the cut was made, but also in that it shows the first segment 101 with groove 104 and the segment 102 with groove 105 connected thereto by means of the pin 132 of the hinge 103 in the unfolded state. It is clear that thanks to the division according to the invention, in particular of the inner lateral surface of the electric heating device 100 into segments 101, 102, it is possible to bring the segments 101, 102 together from different directions on the middle section 153 of the object 150 to be heated and then to fix them. For fixation are in 2e a counter-thread 121 in the first segment 101 and a hole 122 with a concentric extended portion 123 is provided, so that after the segments 101,102 are folded shut, the inner surfaces 106,107 forming the inner lateral surface can be one in 2e second screw 120, not shown, can be fixed in intimate contact with the object 150 to be heated, in particular its middle section 154.

2f shows a cross section of the arrangement 2a along the direction of extension of the object to be heated 150. One can see the channel 151, the sections with a larger radius 152,153 and the middle section 154 as well as the first segment 101 with groove 105 and the cut-open hinge 103, which connects the movable connecting element to the second, not visible in this representation Segment 102 represents.

In addition to the from the 2a until 2f details that can be removed shows the 1a another tubular coil cartridge or a tubular heating element 140, which is inserted into the grooves 104, 105, particularly preferably by being rolled up.

Based on 1b one recognizes as a further detail that here in contrast to the embodiment 2a until 2f two flexible metal strips 108, 109, which are fastened to the first segment 101 and to the second segment 102, serve as connecting elements and allow the electrical heating device 100 to be bent or folded open. In this configuration, it is possible to use the metal strips 108, 109 to define a gap between the first segment 101 and the second segment 102, in which a section 141 of the coiled tubing cartridge or the tubular heating element 140 is guided. This configuration avoids the creation of poorly heated areas, which can lead to problems particularly when using hinges, while at the same time providing a movable connection between the segments 101, 102.

In addition, a thermocouple 170 can also be seen in this representation, which is inserted into a bore of the first segment 101 .

The representation of 1c essentially corresponds to that of the 2c with the two above using the 1a and 1b discussed differences, namely the representation of the electric heating device 100 belonging to the inserted coiled tubing cartridge or the inserted tubular heater 140 and the use of flexible metal strips 108,109 as connecting elements. The same connection exists between the 1d and 2d .

The sectional view of 1e shows the same basic structure as 1d , but the cut is located at the location of the electrical heater 100 where the thermocouple 170 is inserted into the electrical heater 100. FIG. In particular, therefore, in addition to the above-described components of the electrical heating device 100 arranged on the object 150 to be heated, the section 171 of the thermocouple 170, which is arranged on the central section 154 of the object 150 to be heated, can be seen particularly well.

• Wie insbesondere aus den 3a,3b und 3c zu entnehmen ist, liegt hier die Zuführung 341 von Rohrwendelpatrone oder Rohrheizkörper 340 mittig und nicht an einem Ende der elektrischen Heizvorrichtung.

The in the 3a until 3e The electric heating device 300 shown with a first segment 301 with a groove 304, a second segment 302 with a groove 305, a tubular coil cartridge or tubular heating element 340 inserted into the respective grooves and a thermocouple 370 with an end section 371 differs from the configurations discussed so far only with regard to the following details:

• As in particular from the 3a , 3b and 3c can be seen, the feed 341 of the coiled tubing cartridge or tubular heating element 340 is in the middle and not at one end of the electrical heating device.

Like those in particular 3c and 3d show, no movable connecting element is provided between the first segment 301 and the second segment 302 in this electrical heating device, but only rigid connecting elements in the form of screws 310,315,320,325. Like that one in particular 3d it can be seen that the screws 310 , 315 engage with their threads (not shown) in counter threads 311 , 316 cut into or inserted into the first segment 301 . The second segment 302 is penetrated by holes 312,317 for receiving the screws 310,315, each having a concentrically extending enlarged portion 313,318 for receiving the screw head. This makes it possible to create an almost gap-free inner lateral surface, in which the risk of locations occurring at the transition points between the individual segments 301, 302 at which only a lower heating output is transmitted to the object 150 to be heated is minimized.

• Erstens weist die elektrische Heizvorrichtung 400, wie bereits im vorigen Abschnitt erwähnt wurde, zwei Rohrwendelpatronen oder Rohrheizkörper 440,445 auf. Insbesondere in der Darstellung der 4a wird deutlich, dass die Rohrwendelpatrone oder der Rohrheizkörper 440 nur in der Nut 404 des ersten Segments 401 verläuft und dass die Rohrwendelpatrone oder der Rohrheizkörper 445 nur in der Nut 405 des zweiten Segments 402 verläuft. Damit sind die beiden Segmente 401, 402 völlig unabhängig voneinander beheizbar bzw. regelbar und ohne Weiteres einzeln austauschbar, was wartungstechnische Vorteile und eine bessere Kontrolle über die erreichten bzw. erreichbaren Temperaturverteilungen mit sich bringt.

The in the 4a until 4e The illustrated electric heating device 400 with a first segment 401 with a groove 404, a second segment 402 with a groove 405, coiled tubing cartridges or tubular heating elements 440 and 445 inserted into the respective grooves, and a thermocouple 470 with an end section 471 deviates from the embodiment according to only the following details 3 a until 3e away:

• First, as mentioned in the previous section, the electrical heater 400 has two coiled tubing cartridges or tubular heaters 440,445. Especially in the presentation of 4a it is clear that the coiled tubing cartridge or tubular heater 440 only in the groove 404 of the first segment 401 runs and that the coiled tubing cartridge or the tubular heater 445 runs only in the groove 405 of the second segment 402. The two segments 401, 402 can thus be heated or regulated completely independently of one another and can easily be exchanged individually, which entails advantages in terms of maintenance and better control over the temperature distributions that have been achieved or can be achieved.

Second, the geometric arrangement of the as in 3 chosen differently by screws 410,415,420,425. The staggered arrangement, in particular the 4c it can be seen that a deformation of the segments 401, 402 during operation of the electrical heating device can be counteracted more uniformly over the direction of extension of an object to be heated.

Third, the object to be heated is here, such as in particular the 4b and 4c can be seen, specifically designed as a spray nozzle 450, as is used in spray machines. The spray nozzle 450 has a nozzle body 451 with a channel 455 for the material to be sprayed. At the spray end, the nozzle body 451 merges into a nozzle head 453 with a spray opening 454 that projects radially beyond the circumference of the nozzle body 451, while a radially thickened area 452 is present at its device-side end. It is obviously not possible to slide a heating element onto a spray nozzle 450 designed in this way.

Reference List

100,300,400

electric heater

101,301,401

first segment

102,302,402

second segment

103

hinge

104,105,304,305,404,405

groove

106,107

interior surfaces

108,109

flexible metal strip

110,120,310,315,320,325,410,415,420,425

screw

111,121,311,316

counter thread

112,122,312,317

Hole

113,123,313,318

extended section

131,132

hinge pins

140,340,440,445

Tubular coil cartridge or tubular heater

141

Section of coiled tubing cartridge or tubular heater

150

object to be heated

151

channel

152,153,

Sections of the object to be heated

154

Central section of the object to be heated

170,370,470

thermocouple

171,371,471

section of the thermocouple

341

feeding

450

spray nozzle

451

nozzle body

452

radially thickened area

453

nozzle head

454

spray port

Claims (14)

Electrical heating device (100,300,400), in particular for heating surfaces of objects (150,450) to be heated, with an inner lateral surface made of metal and at least one tubular coil cartridge or at least one tubular heating element (140,340,440,445), in which the inner lateral surface made of metal consists of at least two segments (101,102,301,302,401,402) is constructed, wherein each of the segments (101,102,301,302,401,402) is rigidly or movable, in particular foldable, connected or connectable to at least one adjacent segment (101,102,301,302,401,402) via at least one connecting element (103,108,109,110, 120,310,315,320,325), characterized in that a portion (141) of the coiled tubing cartridge or the tubular heating element (140) is guided in a gap between a first segment (101) and a second segment (102). Electrical heater (100,300,400) after claim 1 , characterized in that the segments (101, 102, 301, 302, 401, 402) have at least one groove (104, 105, 304, 305, 404, 405) into which the at least one coiled tubing cartridge or the at least one tubular heating element (140, 340, 440, 445) is inserted. Electrical heater (100,300,400) after claim 1 , characterized in that the segments (101, 102, 301, 302, 401, 402) have a closed cavity in which the at least one coiled tubing cartridge or the at least one tubular heating element (140, 340, 440, 445) is arranged. Electrical heater (100,300,400) after claim 3 , characterized in that the cavity is completely or partially filled with a material, in particular with a powder or granulate. Electrical heater (100,300,400) after claim 1 , characterized in that the segments (101, 102, 301, 302, 401, 402) have at least one section of a winding body or carrier on or in which the at least one coiled tubing cartridge or the at least one tubular heating element (140, 340, 440, 445) are arranged. Electrical heating device (100,300,400) according to one of the preceding claims, characterized in that the segments (101,102,301,302,401,402) define not only the inner lateral surface of the electrical heating device but also an outer lateral surface of the electrical heating device which, when the segments (101,102,301,302,401, 402) are on a surface to be heated Object (150,450) are arranged until the seams between the segments (101,102,301,302, 401,402) are connected. Electrical heating device (100,300,400) according to one of the preceding claims, characterized in that the individual segments (101,102,301,302,401,402) are fully or partially compressed. Electrical heating device (100,300,400) according to any preceding claim, characterized in that each of the segments (101,102,301,302,401,402) is assigned at least one coiled tubing cartridge or at least one tubular heating element (140,340,440,445), so that each of the segments (101,102,301,302,401,402) independently of the other segments (101,102,301,302,401,402) heatable is. Electric heating device (100,300,400) according to one of the preceding claims, characterized in that at least one of the connecting elements is a screw (110,120,310,315,320,325). Electric heating device according to one of the preceding claims, characterized in that at least one of the connecting elements is a hinge (103). Electrical heating device (100,300,400) according to one of the preceding claims, characterized in that at least one clamping device is present, by means of which the segments (101,102,301,302,401,402) can be clamped, in particular when the electrical heating device (100,300,400) is arranged on an object (150,450) to be heated are. Electrical heating device (100,300,400) according to one of the preceding claims, characterized in that the electrical heating device (100,300,400) has at least one thermocouple (170,370,470) or mantle thermometer. Electrical heater (100,300,400) after claim 12 , characterized in that the at least one thermocouple (170,370,470) is accommodated in a bore or guide of at least one segment (101,102, 301,302,401,402). Electric heater (100,300,400) according to any one of Claims 12 or 13 , characterized in that each segment (101,102,301,302,401,402) has a thermocouple (170,370,470) or mantle thermometer.

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