Heating element for a flow channel or mold cavity and injection molding nozzle with such a heating element

Abstract

Heating element (1) for heating a flow channel or a mold cavity, which has a support element (10) which carries a heating conductor (20) with a first connecting pin (21) and a second connecting pin (22), and which includes a connection device (30) with an electrical connecting cable (40) with a first and second conductor (41, 42), a) wherein the first and second connecting pins (21, 22) terminate in an insulating body (50) of the connecting device (30), which electrically separates the first connecting pin (21) from the second connecting pin (22), b) wherein the insulating body (50) is arranged at least partially in a receiving sleeve (60) of the connection device (30), c) wherein the receiving sleeve (60) points with a first end (61) towards the support element (10), is fixed with its first end (61) to the support element (10) and secures the insulating body (50) relative to the support element (10), d) wherein a first crimp sleeve (44) is fixed on the first terminal pin (21) and a second crimp sleeve (45) is fixed on the second terminal pin (22) by plastic deformation, and the first crimp sleeve (44) is fixed on the first conductor (41) and the second crimp sleeve (45) is fixed on the second conductor (42) by plastic deformation, characterized in that e) the receiving sleeve (60) has a second end (62) opposite the first end (61), which forms a third crimp sleeve (63) and is fixed on the connecting cable (40) by plastic deformation in such a way that a tensile restraint is formed which secures the connecting cable (40), and a tensile connection of a cable sheath of the connecting cable (40) to the carrier element (10) is formed via the receiving sleeve (60).

Description

[0001] The invention relates to a heating element for heating a flow channel or a mold cavity according to claim 1 and an injection molding nozzle with such a heating element according to claim 16.

[0002] In injection molding, a flow channel, particularly a hot runner, serves to supply a flowable material—for example, a plastic melt—at a predefined temperature and under high pressure into the cavity of a mold (e.g., a mold plate). A specific section of the flow channel can be formed by an injection molding nozzle. These nozzles typically have a material tube with a flow channel that terminates in a nozzle tip. The latter forms a nozzle outlet at its end, which opens into the mold cavity via a sprue.

[0003] To prevent the flowable material within the hot runner or flow channel from cooling prematurely, electric heating elements with heating conductors are used. Their electrical conductors are routed via cables from the injection mold, which encompasses the flow channel and the mold itself. The connections on the heating elements are thus exposed to high temperatures and strong shocks and vibrations. This is particularly true for heating elements mounted externally on the material tube of an injection molding nozzle. In this area, there is usually very little available space. In a specific design, the heating elements feature a sleeve-shaped support element and an electrical conductor that generates heat when an electrical voltage is applied or an electric current flows through it.

[0004] The same problems arise when heating a mold cavity. Here, too, the heating element, which may be applied to a section of the wall or embedded in the mold cavity wall, is subjected to strong shocks and vibrations, which puts considerable stress on the heating element's connections. In addition, the often limited space makes it difficult to provide a permanently reliable electrical connection.

[0005] The electrical conductor can be – as disclosed, for example, in DE 10 2006 049 669 A1 – a heating coil formed from resistance wire. US 4 486 650 A discloses, in combination with a heating coil, for example, a detachable plug connection between the terminals of the heating coil and the connecting cable of a power supply.

[0006] The following example uses a thick-film heating element mounted on a cylindrical support. However, the invention is not limited to this and can be applied in the same way to other types and shapes of heating elements.

[0007] DE 10 2006 049 667 A1 uses so-called thick-film heating elements, which are applied as heating conductor tracks to a sleeve as a carrier element using a screen printing process. An insulating layer, also applied as a thick film using a screen printing process, is optionally provided between the carrier element and the electrical conductor. To keep the size of the heating element particularly small, the carrier element – ​​as described in DE 199 41 038 A1 – can also be the material tube of an injection molding nozzle itself.

[0008] To supply the thick-film heating element with energy, a connection contact is provided at each end of the heating conductor track, e.g., in the form of a connecting wire or a connecting pin (see WO 2005 / 053361 A2, DE 10 2008 004 526 A1 or DE 10 2008 015 376 A1). The heating conductor track is connected to the connecting lead of a power source via the connection contact.

[0009] Furthermore, DE 10 2012 101 400 A1 discloses an injection molding nozzle with an electric heating element, which includes a connection device for generating an electrical connection to a connecting cable. The connecting contacts of the heating element terminate in an insulating body of the connecting device, which electrically isolates the connecting contacts from one another. The connecting cable has contact elements that can be electrically contacted with the connecting contacts of the heating element, the insulating body being arranged at least partially in a receiving sleeve of the connecting device. The connecting cable has a plug or coupling at its end that can be detachably fixed in or on the receiving sleeve such that the contact elements of the connecting cable make electrical contact with the connecting contacts of the heating element. A first end of the receiving sleeve, pointing towards the heating element, surrounds the insulating body.At this first end, the receiving sleeve also has two feet pointing outwards opposite each other and attached to the heating element.

[0010] A disadvantage of this design is that the entire connection has a considerable height, protruding from the heating element. This requires additional space in the injection mold. Consequently, the arrangement of flow channels and additional injection nozzles within this space is precluded. The design of the mold cavity is also limited. Furthermore, the relatively tall structure creates a relatively long lever arm, which, when the cable is pulled, can exert pressure on the connection and potentially damage it.

[0011] Furthermore, US 5 235 737 A describes a method for manufacturing a valve for an injection molding device with an electric heating element that is placed in a channel.

[0012] Furthermore, US 2003 / 0218006 A1 describes a heating device for injection molding processes and its manufacture.

[0013] Furthermore, US 4207552A describes an electric heating element with a particularly advantageous electrical connector.

[0014] The object of the invention is therefore to provide a heating element for a flow channel or a mold cavity, as well as an injection molding nozzle with such a heating element, wherein the heating element has a compact connection device. The connection device should ensure a consistently sufficient and reliable electrical contact between the connection contacts of the heating conductors and the connecting cable connected to the power source. Due to the high temperatures prevailing during injection molding, it must be temperature-resistant and withstand mechanical tensile loads that can occur during the installation and removal of the injection molding nozzle and / or when replacing the heating element, as well as due to vibrations and shocks.

[0015] The main features of the invention are specified in the characterizing part of claim 1 and in claim 16. Embodiments are the subject of claims 2 to 15.

[0016] The invention relates to a heating element for heating a flow channel or a mold cavity, in particular a hot runner, comprising a support element which carries a heating conductor with a first connecting pin and a second connecting pin, and comprising a connection device with an electrical connecting cable having a first and second conductor, wherein the first and second connecting pins terminate in an insulating body of the connection device which electrically separates the first connecting pin from the second connecting pin, wherein the insulating body is arranged at least partially in a receiving sleeve of the connection device, and wherein the receiving sleeve points with a first end towards the support element, is fixed with its first end to the support element and secures the insulating body relative to the support element.wherein a first crimp sleeve is fixed on the first terminal pin and a second crimp sleeve is fixed on the second terminal pin, each by plastic deformation, and the first crimp sleeve is fixed on the first conductor and the second crimp sleeve is fixed on the second conductor, each by plastic deformation.

[0017] The advantage of this design is that, compared to a plug-in connection, whose overall height can be reduced to approximately 33 mm, the overall height or protrusion above the support element can be reduced to 19 mm or even less. The connection between the receiving sleeve and the support element results in a stable connection, and the electrical conductors and connecting pins are well protected from external stresses within the insulating body. A consistently sufficient and reliable electrical contact is established between the connection contacts of the heating conductor tracks and the connecting cable to the power source. This contact is also resistant to high temperatures, vibrations, and shocks.

[0018] The receiving sleeve is designed to have a second end opposite the first, which forms a third crimp sleeve and is secured to the connecting cable by plastic deformation. This creates a tensile restraint that secures the connecting cable. This reduces the risk of the crimp connections or the connecting pins being subjected to tensile forces. In particular, this creates a tensile connection between the cable sheath and the support element via the receiving sleeve.

[0019] In a preferred embodiment, the support element is tubular or sleeve-shaped. This makes it particularly suitable for heating a flowing fluid. The fluid can either flow directly through the support element, or the support element can be placed or slid onto a tube. In particular, a support element designed in this way can be placed onto a material tube of an injection molding nozzle for the production of plastic parts.

[0020] Increased connection strength is achieved when the insulating body rests on the support element with a form-fitting contact surface. For a tubular or sleeve-shaped support element, a concave contact surface, especially a partially cylindrical one, is ideal.

[0021] In a more detailed embodiment of the invention, the first end of the receiving sleeve encompasses the insulating body and has two feet at this first end that point outwards opposite each other and are attached to the support element.

[0022] The feet provide a stable connection to the support element and effectively counteract tilting moments in an otherwise slim connection. The feet are preferably bonded to the support element; in particular, both the feet and the support element should be made of metal and welded together.

[0023] Furthermore, the feet should be formed in one piece, especially monolithically, attached to and from the receiving sleeve. This ensures high strength between the feet and the receiving sleeve.

[0024] According to a special variant of the invention, the feet are each fixed to the receiving sleeve with a leg section and are each attached to the support element with a support section resting on the support element.

[0025] A particularly advantageous design features feet that are adapted to the outer contour of the insulating body in such a way that they follow the outer contour, especially with the leg section. This ensures a secure hold on the insulating body and a very compact connection device.

[0026] The connection device is particularly suitable for variants where the heating conductor is applied to the carrier element using layer technology. In these variants, the contact points at the transition to the contact pins are especially sensitive to tensile and compressive stresses. According to the invention, these stresses can be largely prevented. An electrically conductive thick film proves to be particularly suitable as a heating conductor. Preferably, such an electrically conductive thick film is arranged on a first insulating layer applied to the carrier element using layer technology, particularly thick-film technology. This allows the carrier element to be made of electrically conductive material, especially a metal. It is advantageous to cover the electrically conductive thick film with a second insulating layer applied using layer technology, particularly thick-film technology. This encapsulates and protects the electrical conductors.For direct attachment of the feet to the support element, the first insulating layer and / or the second insulating layer should have a recess in the area of ​​the feet.

[0027] Another variant of the invention provides that the receiving sleeve is made of metal. Metal is heat-resistant and can withstand tensile forces well. It is also easily plastically deformed and thus crimped. The support element is also preferably made of metal.

[0028] Due to its specific shape, the insulating body has a neck section and a base section, with the receiving sleeve resting on the base section of the insulating body. This design means the connection is wider and stable only in the area of ​​the support element. Further away from the support element, it is slim. Furthermore, this creates a secure, positive fit between the receiving sleeve and the insulating body.

[0029] To increase safety, an addendum stipulates that an earthing conductor of the connecting cable is electrically connected to the receiving sleeve. If the electrical supply or return line, or the heating conductor track, comes into contact with the receiving sleeve, the current is then diverted via the earthing cable.

[0030] To avoid electrical contact, a design is suitable in which the insulating body has two through holes, with one of the first and second crimp sleeves arranged in each through hole.

[0031] Particularly good strain relief of the connecting pins can be achieved with a special design in which the through-holes are each formed from a first, a second, and a third section, each having at least two different diameters. Specifically, the first section should be located on the side of the support element and have a larger diameter than the second section, which lies between the first and third sections. The plastic deformations of the crimp sleeves in the area of ​​the connecting pins are located within the first section, a central area of ​​the crimp sleeves without plastic deformation is located in the area of ​​the second section, and the plastic deformations of the crimp sleeves in the area of ​​the conductors are located within the third section.In this way, a positive fit can be formed between the insulating body and the crimp sleeves. For this to work, the diameter of the second section should be smaller than the diameter of the crimp sleeves in the area of ​​plastic deformation. It is advantageous if the diameter of the second section essentially corresponds to the diameter of the crimp sleeves in the non-plastically deformed area. For common heating capacities in injection molding, diameters of 1.6 ± 0.10 mm for the first and third sections and 1.15 ± 0.10 / - 0.05 mm for the second section are suitable, for example. A crimp sleeve with a diameter of 1.00 mm can be used here as an example.

[0032] Furthermore, the first and second crimp sleeves should each have a cylindrical outer surface. Such crimp sleeves provide a minimal diameter and thus a compact connection device. Preferably, the first and second crimp sleeves each have an internal chamfer, at least on the conductor side. This facilitates the insertion of the conductors.

[0033] For assembly reasons, a specific embodiment of the invention provides that the insulating body is formed in two parts: a support element that rests on the carrier element, and a head element that is positioned adjacent to the support element on the side opposite the carrier element. This enables a positive fit with the crimp sleeves on both sides. For this purpose, the first and second sections should be formed in the support element, while the third section should be formed in the head element. This allows the support element to be slid over the crimp sleeves after they have been crimped onto the connecting pins. It is advantageous if the connecting pins are essentially or exactly flush with the support element. During assembly, the remaining free end of the crimp sleeves then protrudes from the support element and can be crimped to the electrical conductors.The head element is then pushed from the conductors onto the crimp sleeves and to the mounting element.

[0034] To separate the electrical conductors from each other, the insulating body should be flush with or extend beyond the crimp sleeves, especially perpendicular to the longitudinal direction.

[0035] According to a specific embodiment of the heating element, the receiving sleeve consists of a first and a second sleeve section that are welded together, with the first sleeve section forming the first end of the receiving sleeve. In other words, the first sleeve section secures the insulating body, or at least its support element, to the carrier element. This effectively protects the connecting pins before the electrical conductors are connected to the crimp sleeves and can exert uncontrolled tensile and leverage forces on the connecting pins by hanging down. Preferably, the two sleeve sections are joined by laser welding. In particular, the second sleeve section can first be slid onto the conductors or the connecting cable until the first and second crimp sleeves are deformed. The second sleeve section can then be slid towards the first sleeve section and connected to it.

[0036] Preferably, the second sleeve section is inserted into the first sleeve section. Optionally, a circumferential weld groove can be formed between the first and second sleeve sections, into which the weld is then placed. Such a groove preferably has a triangular cross-section. This facilitates convenient assembly and welding, and also results in a high-quality appearance.

[0037] With a two-part receiving sleeve, it is possible to route a grounding conductor of the connecting cable between the two sleeve sections and electrically secure it to the outside of one of the sleeve sections, particularly by laser marking. This is especially simple and cost-effective.

[0038] Optionally, one or two additional connection contacts with contact pins are arranged in the insulating body, which are electrically connected to a temperature sensor. Both wire-type temperature sensors and, in particular, temperature sensors manufactured using thick-film technology are suitable. For wire-type temperature sensors, the receiving sleeve can optionally have a fastening element. This is then preferably located on the outside of the receiving sleeve.

[0039] The invention further relates to an injection molding nozzle with a flow channel, in particular a hot runner, in a material tube, and with a heating element as described above, which is thermally coupled to the material tube for heating the flow channel. Such an injection molding nozzle thus has a stable electrical connection and is particularly compact. It is therefore suitable for particularly small distances between injection points arranged in a mold plate, into which the material tube opens.

[0040] The injection molding nozzle can have a housing that encloses the heating element. This housing protects the heating element. Preferably, the housing has a lateral recess that is open in the longitudinal direction of the flow channel, with the receiving sleeve projecting through this recess. This facilitates easy (dis)assembly.

[0041] Further features, details and advantages of the invention will become apparent from the wording of the claims and from the following description of exemplary embodiments with reference to the drawings. The drawings show: Fig. 1. A perspective view of a heating element; Fig. 2 a section through a connection device of a heating element; Fig. 3 a longitudinal section through an insulating body; and Fig. 4 A perspective exploded view of an injection molding nozzle with a heating element.

[0042] Fig. Figure 1 shows a perspective view of a heating element 1 for heating a flow channel in a hot runner nozzle, which is, for example, a component of a hot runner mold. The heating element 1 has a tubular support element 10, which carries a heating conductor 20 with a first connecting pin 21 and a second connecting pin 22. It also has a connection device 30 with an electrical connection cable 40 having a first and second conductor 41, 42, wherein the first and second connecting pins 21, 22 terminate in an insulating body 50 of the connection device 30.

[0043] The insulating body 50 is arranged section by section in a receiving sleeve 60 of the connection device 30. It has a neck section 51 and a base section 52, wherein the receiving sleeve 60 is supported on the base section 52 of the insulating body 50.

[0044] The receiving sleeve 60 has a first end 61 pointing towards the support element 10, is fixed to the support element 10 at this first end 61, and secures the insulating body 50 relative to the support element 10. For this purpose, the first end 61 of the receiving sleeve 60 encompasses the insulating body 50. Furthermore, the receiving sleeve 60 has two opposing, outwardly projecting feet 64, 65 at this first end 61, which are attached to the support element 10. The two feet 64, 65 point in opposite directions along the longitudinal direction L of the tubular support element 10 and are bonded to the support element 10, in particular by welding or laser welding. For this purpose, the receiving sleeve 60 and the support element 10 are each made of the same metal.

[0045] It can be seen that the feet 64, 65 are formed monolithically as a single piece with the receiving sleeve 60. Each foot 64, 65 is divided into a leg section 66, 67, which is fixed to the receiving sleeve 60, and a support section 68, 69, which rests on the support element 10 and is attached to the support element 10. Furthermore, it can be seen how the feet 64, 65, in particular their leg sections 66, 67, are adapted to the outer contour of the insulating body 50 in such a way that they follow the outer contour.

[0046] A second end 62, opposite the first end 61, is formed as a third crimp sleeve 63 and is fixed to the connecting cable 40, in particular its protective sheath 46, by plastic deformation. The receiving sleeve 60 thus extends beyond the insulating body 50 with its second end 62.

[0047] For assembly reasons, the receiving sleeve 60 is formed from a first and a second sleeve section 71, 72, which are welded together, wherein the first sleeve section 71 forms the first end 61 of the receiving sleeve 60 and the second sleeve section 72 forms the third crimp sleeve 63.

[0048] Furthermore, a fastening element 70 can be seen on the outside of the receiving sleeve 60, to which a temperature sensor 80 is attached. In particular, the fastening element 70 is a through-hole through which the temperature sensor is threaded.

[0049] Based on the contact surface 57 of the insulating body 50, which lies close to the support element 10, it can be seen that it is shaped to fit the tube shape of the support element 10.

[0050] Fig. Figure 2 shows a section through a connection device 30 of a heating element 1. The description of Fig. 1 also applies to the representation according to Fig. 2. Therefore, only the additional recognizable features will be described below.

[0051] On average, this is how one can see after Fig. 2 a heating conductor 20, which is formed from an electrically conductive thick film 23. This lies on a first insulating layer 24 applied to the support element 10 using thick-film technology and is covered with a second insulating layer 25 applied using thick-film technology. However, the first insulating layer 24 and the second insulating layer 25 have a recess 26 in the area of ​​the feet 64, 65.

[0052] The heating conductor 20 has a first connecting pin 21 and a second connecting pin 22. These each have a relief loop or arc and project perpendicularly from the support element 10. The first and second connecting pins 21, 22 terminate in the insulating body 50, which electrically isolates the first connecting pin 21 from the second connecting pin 22. A first crimp sleeve 44 is attached to the first connecting pin 21 and a second crimp sleeve 45 is attached to the second connecting pin 22, each by plastic deformation.

[0053] Furthermore, the electrical connecting cable 40 has a first and a second conductor 41, 42. The first crimp sleeve 44 is fixed to the first conductor 41 and the second crimp sleeve 45 is fixed to the second conductor 42, each by plastic deformation. The insulating body 50 has two through-holes 53, 54, with one of the first and second crimp sleeves 44, 45 being arranged in each through-hole 53, 54. The first and second crimp sleeves 44, 45 each have a cylindrical outer and inner sheath surface, at least before they are deformed. In addition, the first and second crimp sleeves 44, 45 have an inner chamfer 47, at least on the side of the conductors 41, 42.

[0054] Furthermore, it can be seen that the insulating body 50 is formed in two parts: a support element 55, which rests on the support element 10, and a head element 56, which is positioned adjacent to the support element 55 on the side opposite the support element 10. The connecting pins 21, 22 are flush with the support element 55.

[0055] In this way, the head element 56 can first be slid onto the electrical conductors 41, 42 during assembly, while the support element 55 is already fixed to the carrier element 10 by the first sleeve section 71. As soon as the conductors 41, 42 are connected to the first and second crimp sleeves 44, 45, the head element 56 is then slid onto the support element 55. The insulating body 50 then projects beyond the first and second crimp sleeves 44, 45, particularly with the head element 56.

[0056] The second sleeve section 72 can also initially be pushed onto the conductors 41, 42 or the connecting cable 40 until the first and second crimp sleeves 44, 45 are deformed. The second sleeve section 72 can then be pushed to the first sleeve section 71 and connected to it. It then also secures the head element 56 of the insulating body 50.

[0057] In Fig. Figure 3 shows a longitudinal section through an insulating body 50. A through-hole 53 is located in this longitudinal section and is composed of a first, a second, and a third section A1, A2, A3. The sections A1, A2, and A3 have two different diameters. The first section A1, which is later arranged on the side of the support element 10, in particular with a bearing surface 57, has a larger diameter than the second section A2. The second section A2 is arranged between the first and third sections A1 and A3. The third section A3 has a larger diameter than the second section A2. Specifically, the first and third sections A1 and A3 have the same diameter.

[0058] In this way, it is possible for the plastic deformations of the crimp sleeves on the side of the connecting pins to lie within the first section A1, a central area of ​​the crimp sleeves without plastic deformation to be located in the area of ​​the second section A2, and the plastic deformations of the crimp sleeves on the conductor side to lie within the third section A3. A stable connection is achieved when the diameter of the second section A2 is smaller than the diameter of the crimp sleeves in the area of ​​plastic deformation. For this to occur, the diameter of the second section A2 should essentially correspond to the diameter of the crimp sleeves in the area without plastic deformation.

[0059] To enable assembly, the insulating body 50 consists of a support element 55, which forms a base section 52 with a bearing surface 57, and a head element 56, which forms a neck section 51. The support element 55 carries the first and second sections A1 and A2. It can be slid onto the support element once the crimp sleeves are connected to the terminals. The crimp sleeves can then be connected to terminals outside the support element 55 before the head element is slid over the deformation of the crimp sleeve.

[0060] For common heating capacities in injection molding, diameters of 1.6 ± 0.10 mm for the first and third sections and 1.15 ± 0.10 / - 0.05 mm are suitable. A crimp sleeve with a 1.00 mm diameter can be used as an example.

[0061] Fig. Figure 4 shows a perspective exploded view of an injection molding nozzle 100 with a heating element 1. In particular, the heating element 100 corresponds technically to the representation in Fig. 1. Therefore, regarding the description of the heating element, please refer to the description above.

[0062] The sleeve-shaped heating element 1 is pushed onto a material tube 102 of the injection molding nozzle, which extends in the direction of the longitudinal axis L. This thermally couples the heating element 1 to the material tube 102 for heating the flow channel 101. Preferably, at room temperature, a clearance fit is formed between the material tube 102 and the sleeve-shaped heating element 1. At the operating temperature of the heating element and the material tube 102, an interference fit should be formed. This achieves good thermal coupling with simple assembly. For this purpose, the coefficient of thermal expansion of the material tube 102 should be greater than the coefficient of thermal expansion of the heating element 1, in particular of its sleeve-shaped support element.

[0063] Furthermore, it can be seen that a housing 103 is provided, consisting of a housing head 105 and a housing shaft 106. A recess 104 in the form of a lateral longitudinal slot is provided in the housing head 105, which is open in the direction of the connection device 30.

[0064] In the exploded view shown, the material tube 102 with the heating element 1 has been pulled out of the housing shaft 106. Furthermore, the heating element 1 is not fully pushed onto the material tube 102.

[0065] The injection molding nozzle 100 is correctly mounted when the heating element 1 is pushed longitudinally L towards the housing head 105, so that the connecting device 30, projecting transversely to the longitudinal direction, is positioned within the lateral recess 104 in the housing head 105. The housing shaft 106 is also pushed longitudinally L towards the housing head 105 until their opposing flange edges abut each other. The housing shaft 106 and the housing head 105 are then fixed together using screws 107. The material tube 102 and the heating element 1 are then essentially located inside the housing 103.

[0066] Such an injection molding nozzle can be connected either to a central machine nozzle or a distributor plate, in particular with the housing head 105. At the other end, the housing shaft 106 and the material tube 102 then protrude into a sprue opening of a mold plate, in which a cavity for forming a component is formed (also called mold cavity).

[0067] The invention is not limited to one of the embodiments described above, but can be modified in many ways.

[0068] In particular, it is possible to electrically connect an earthing conductor of the connecting cable 40 to the receiving sleeve 60. Specifically, the earthing conductor of the connecting cable 40 can be routed out between the two sleeve sections 71, 72 and electrically secured to the outside of one of the sleeve sections 71, 72, in particular by laser welding.

[0069] It is also conceivable (not shown further) to use the heating element 1 in a (likewise not shown) mold cavity of an injection mold, for example to heat a section of the mold cavity wall.

[0070] All features and advantages arising from the claims, the description and the drawing, including design details, spatial arrangements and process steps, can be essential to the invention both individually and in various combinations. Reference symbol list 1 heating element 10 support element 20 heating conductors 21 first connecting pin 22 second connecting pin 23 electrically conductive thick film 24 first insulating layer 25 second insulating layer 26 recess 30 Connection device 40 connection cables 41 first leader 42 second conductor 44 first crimp sleeve 45 second crimp sleeve 46 Protective coat 47 Inner chamfer 50 insulating bodies 51 Neck section 52 Base section 53 first through hole 54 second through hole 55 uprising element 56 Head element 57 contact area 60 Mounting sleeve 61 first end (receiving sleeve) 62 second end (receiving sleeve) 63 third crimp sleeve 64 first foot 65 second foot 66 Thigh section (first foot) 67 Thigh section (second foot) 68 Support section (first foot) 69th page (second foot) 70 Fasteners 71 first sleeve section 72 second sleeve section 80 thermocouples 100 injection molding nozzles 101 Flow channel 102 Material pipe 103 cases 104 recess 105 Housing head 106 Housing shaft A1 first section A2 second section A3 third section L Longitudinal direction (support element)

Claims

Heating element (1) for heating a flow channel or a mold cavity, comprising a support element (10) which carries a heating conductor (20) with a first connecting pin (21) and a second connecting pin (22), and comprising a connection device (30) with an electrical connecting cable (40) having a first and second conductor (41, 42), a) wherein the first and second connecting pins (21, 22) terminate in an insulating body (50) of the connection device (30), which electrically separates the first connecting pin (21) from the second connecting pin (22), b) wherein the insulating body (50) is arranged at least partially in a receiving sleeve (60) of the connection device (30), c) wherein the receiving sleeve (60) has a first end (61) pointing towards the support element (10), is fixed to the support element (10) with its first end (61), and separates the insulating body (50) relative to the support element (10). determinesd) wherein a first crimp sleeve (44) is fixed on the first connecting pin (21) and a second crimp sleeve (45) is fixed on the second connecting pin (22) by plastic deformation, and the first crimp sleeve (44) is fixed on the first conductor (41) and the second crimp sleeve (45) is fixed on the second conductor (42) by plastic deformation, characterized in that e) the receiving sleeve (60) has a second end (62) opposite the first end (61), which forms a third crimp sleeve (63) and is fixed on the connecting cable (40) by plastic deformation in such a way that a tensile restraint is formed which secures the connecting cable (40), and a tensile connection of a cable sheath of the connecting cable (40) to the support element (10) is formed via the receiving sleeve (60). Heating element (1) according to claim 1, characterized in that the support element (10) is tubular or cuff-shaped. Heating element (1) according to one of the preceding claims, characterized in that the first end (61) of the receiving sleeve (60) surrounds the insulating body (50) and has two feet (64, 65) opposite each other and directed outwards at this first end (61) and attached to the support element (10). Heating element (1) according to claim 3, characterized in that the feet (64, 65) are adapted to the outer contour of the insulating body (50) in such a way that they follow the outer contour. Heating element (1) according to one of the preceding claims, characterized in that the heating conductor (20) is applied to the carrier element (10) using layer technology. Heating element (1) according to one of the preceding claims, characterized in that the receiving sleeve (60) is made of metal. Heating element (1) according to one of the preceding claims, characterized in that the insulating body (50) has a neck section (51) and a base section (52), wherein the receiving sleeve (60) is supported on the base section (52) of the insulating body (50). Heating element (1) according to one of the preceding claims, characterized in that an earthing conductor of the connecting cable (40) is electrically connected to the receiving sleeve (60). Heating element (1) according to one of the preceding claims, characterized in that the insulating body (50) has two through holes (53, 54), wherein one of the first and second crimp sleeves (44, 45) is arranged in each through hole (53, 54). Heating element (1) according to claim 9, characterized in that the through holes (53, 54) are each formed from a first, a second and a third section (A1, A2, A3) which have at least two different diameters. Heating element (1) according to claim 10, characterized in that the first section (A1) is arranged on the side of the support element (10) and has a larger diameter than the second section (A2), which lies between the first and third sections (A1, A3), and that the third section (A3) has a larger diameter than the second section (A2), wherein the plastic deformations of the crimp sleeves (44, 45) in the area of ​​the connecting pins (21, 22) are located within the first section (A1), a central area of ​​the crimp sleeves (44, 45) without plastic deformation is arranged in the area of ​​the second section (A2), and the plastic deformations of the crimp sleeves (44, 45) in the area of ​​the conductors (41, 42) are located within the third section (A3). Heating element (1) according to one of the preceding claims, characterized in that the insulating body (50) is formed in two parts from a support element (55) which rests on the support element (10) and a head element (56) which is positioned on the side opposite the support element (10) adjacent to the support element (55). Heating element (1) according to one of the preceding claims, characterized in that the insulating body (50) terminates with or extends beyond the crimp sleeves (44, 45). Heating element (1) according to one of the preceding claims, characterized in that the receiving sleeve (60) consists of a first and a second sleeve section (71, 72) which are welded together, wherein the first sleeve section (71, 72) forms the first end (61) of the receiving sleeve (60). Injection molding nozzle (100) with a flow channel (101) in a material tube (102), and with a heating element (1) according to one of the preceding claims, which is thermally coupled to the material tube (102) for heating the flow channel (101).

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