Heating element for a flow channel or a mould impression and injection-moulding nozzle with such a heating element

Abstract

A heating element for flow channel heating or for heating a mould impression and an injection-moulding nozzle incorporating the heating element are disclosed. The heating element has a carrier element which carries a heating conductor with first and second connection pins, and a connection device with an electrical connection cable with first and second conductors. The first and second connection pins end in an insulator. The insulator is arranged at least in certain portions in a receiving sleeve of the connection device, and the receiving sleeve points with a first end in the direction of the carrier element, is fixed with the first end on the carrier element and fixes the insulator in relation to the carrier element. A first crimping sleeve is fixed on the first connection pin and the first conductor, and a second crimping sleeve is fixed on the second connection pin and the second conductor.

Claims

1. A heating element for heating a flow channel or a mould cavity, comprising: a carrier element, which carries a heating conductor with a first connection pin and a second connection pin, and a connection device comprising: an electrical connection cable with a first conductor and a second conductor arranged within a protective jacket, an insulator having a neck portion and a base portion, a receiving sleeve for the insulator, the receiving sleeve having a first end and a second end, wherein the first and second connection pins end in the insulator of the connection device, wherein the insulator separates the first connection pin electrically from the second connection pin, wherein a first crimping sleeve is fixed on the first connection pin and a second crimping sleeve is fixed on the second connection pin, in each case by plastic deformation, wherein the first crimping sleeve is fixed on the first conductor and the second crimping sleeve is fixed on the second conductor, in each case by plastic deformation, wherein the insulator is arranged at least in sections in the receiving sleeve of the connection device, wherein the insulator has two through-holes, wherein one of the first and second crimping sleeves is arranged in each through-hole, wherein the through-holes are respectively formed by a first, a second, and a third portion, which have at least two different diameters, wherein the insulator is formed in two parts, comprising a standing element, which stands on the carrier element, and a head element, which is positioned adjacent to the standing element, wherein the standing element of the insulator stands with a resting surface of an adapted form on the carrier element, wherein the receiving sleeve pointing with a first end in the direction of the carrier element, is fixed with the first end on the carrier element and fixes the insulator in relation to the carrier element, and wherein the second end of the receiving sleeve forms a third crimping sleeve being fixed on the protective jacket of the electrical connection cable by plastic deformation.

2. The heating element according to claim 1, characterized in that the carrier element is in the form of a tube or sleeve.

3. The heating element according to claim 1, characterized in that the first end of the receiving sleeve reaches around the insulator and has at this first end two feet pointing outwards opposite from one another and fastened to the carrier element.

4. The heating element according to claim 3, characterized in that the feet are adapted to an outer contour of the insulator such that they follow the outer contour.

5. The heating element according to claim 1, characterized in that the heating conductor is applied to the carrier element by film technology.

6. The heating element according to claim 1, characterized in that the receiving sleeve consists of metal.

7. The heating element according to claim 1, wherein the receiving sleeve is supported on the base portion of the insulator.

8. The heating element according to claim 1, characterized in that an earthing conductor of the connection cable is connected in an electrically conducting manner to the receiving sleeve.

9. The heating element according to claim 1, characterized in that the first portion is arranged on the side of the carrier element and has a greater diameter than the second portion, which lies between the first and third portions, and in that the third portion has a greater diameter than the second portion, wherein the plastic deformations of the crimping sleeves in the region of the connection pins lie within the first portion, a middle region of the crimping sleeves without plastic deformation is arranged in the region of the second portion, and the plastic deformations of the crimping sleeves in the region of the conductors lie within the third portion.

10. The heating element according to claim 1, characterized in that the insulator is formed in two parts, comprising a standing element, which stands on the carrier element, and a head element, which is positioned adjacent to the standing element on the side opposite from the carrier element.

11. The heating element according to claim 1, characterized in that the insulator terminates with the crimping sleeves or protrudes beyond them.

12. The heating element according to claim 1, characterized in that the receiving sleeve consists of a first sleeve portion and a second sleeve portion, which are welded to one another, wherein the first sleeve portion forms the first end of the receiving sleeve.

Description

BRIEF DESCRIPTION OF THE DRAWINGS

(1) Further features, details and advantages of the invention emerge from the wording of the claims and from the following description of exemplary embodiments on the basis of the drawings, in which:

(2) FIG. 1 shows a perspective view of a heating element;

(3) FIG. 2 shows a section through a connection device of a heating element;

(4) FIG. 3 shows a longitudinal section through an insulator; and

(5) FIG. 4 shows a perspective exploded representation of an injection-moulding nozzle with a heating element.

DETAILED DESCRIPTION

(6) FIG. 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 part of a hot runner mould. The heating element 1 has a tubular carrier element 10, which carries a heating conductor 20 with a first connection pin 21 and a second connection pin 22. It also has a connection device 30 with an electrical connection cable 40 with a first and a second conductor 41, 42, wherein the first and second connection pins 21, 22 end in an insulator 50 of the connection device 30.

(7) The insulator 50 is arranged in certain portions in a receiving sleeve 60 of the connection device 30. It has in this case a neck portion 51 and a base portion 52, wherein the receiving sleeve 60 is supported on the base portion 52 of the insulator 50.

(8) The receiving sleeve 60 points with a first end 61 in the direction of the carrier element 10, is fixed with this first end 61 on the carrier element 10 and fixes the insulator 50 in relation to the carrier element 10. For this purpose, the first end 61 of the receiving sleeve 60 reaches around the insulator 50. Furthermore, the receiving sleeve 60 has at this first end 61 two feet 64, 65 pointing outwards opposite from one another and fastened to the carrier element 10. The two feet 64, 65 point oppositely in the longitudinal direction L of the tubular carrier element 10 and are fastened with a material bond on the carrier element 10, in particular are welded on or laser-welded. For this, the receiving sleeve 60 and the carrier element 10 respectively consist of a metal.

(9) It can be seen that the feet 64, 65 are formed monolithically in one part with the receiving sleeve 60. The feet 64, 65 are respectively divided into a leg portion 66, 67, which is fixed on the receiving sleeve 60, and a resting portion 68, 69, which rests on the carrier element 10 and is fastened to the carrier element 10. It can also be seen how the feet 64, 65, in particular their leg portions 66, 67, are adapted to the outer contour of the insulator 50 such that they follow the outer contour.

(10) A second end 62, opposite from the first end 61, is formed as a third crimping sleeve 63 and is fixed on the connection cable 40, in particular its protective jacket 46, by plastic deformation. The receiving sleeve 60 therefore extends with the second end 62 beyond the insulator 50.

(11) For assembly reasons, the receiving sleeve 60 is formed by a first and a second sleeve portion 71, 72, which are welded to one another, wherein the first sleeve portion 71 forms the first end 61 of the receiving sleeve 60 and the second sleeve portion 72 forms the third crimping sleeve 63.

(12) A fastening means 70 can also be seen on the outer side of the receiving sleeve 60, on which a thermocouple 80 is fixed. In particular, the fastening means 70 is an insertion opening, through which the thermocouple is inserted.

(13) It can be seen from the abutting surface 57 of the insulator 50 lying closely against the carrier element 10 that it is adapted in its form to the tube shape of the carrier element 10.

(14) FIG. 2 shows a section through a connection device 30 of a heating element 1. The description relating to FIG. 1 also applies to the representation shown in FIG. 2. Therefore, only the features that can be additionally seen are described hereafter.

(15) For instance, in the section shown in FIG. 2 there can be seen a heating conductor 20, which is formed by an electrically conducting thick film 23. This lies on a first insulating layer 24, which is applied to the carrier element 10 by the thick-film technique and is covered with a second insulating layer 25, applied by the thick-film technique. However, the first insulating layer 24 and the second insulating layer 25 have a clearance 26 in the region of the feet 64, 65.

(16) The heating conductor 20 has a first connection pin 21 and a second connection pin 22. These respectively have a relieving loop or bow and protrude perpendicularly from the carrier element 10. The first and second connection pins 21, 22 end in the insulator 50, which separates the first connection pin 21 electrically from the second connection pin 22. A first crimping sleeve 44 is fixed on the first connection pin 21 and a second crimping sleeve 45 is fixed on the second connection pin 22, in each case by plastic deformation.

(17) Furthermore, the electrical connection cable 40 has a first and a second conductor 41, 42. The first crimping sleeve 44 is fixed on the first conductor 41 and the second crimping sleeve 45 is fixed on the second conductor 42, in each case by plastic deformation. The insulator 50 has two through-holes 53, 54, wherein one of the first and second crimping sleeves 44, 45 is arranged in each through-hole 53, 54. The first and second crimping sleeves 44, 45 respectively have a cylindrical outer and inner lateral surface, at least before they are deformed. The first and second crimping sleeves 44, 45 also have at least on the side towards the conductors 41, 42 an inner bevel 47.

(18) It can also be seen that the insulator 50 is formed in two parts, comprising a standing element 55, which stands on the carrier element 10, and a head element 56, which is positioned adjacent to the standing element 55 on the side opposite from the carrier element 10. The connection pins 21, 22 terminate flush with the standing element 55.

(19) In this way, during assembly the head element 56 can first be pushed onto the electrical conductors 41, 42, while the standing element 55 is already fixed with the first sleeve portion 71 on the carrier element 10. As soon as the conductors 41, 42 are connected to the first and second crimping sleeves 44, 45, the head element 56 is then pushed towards the standing element 55. The insulator 50 then protrudes in particular with the head element 56 beyond the first and second crimping sleeves 44, 45.

(20) The second sleeve portion 72 may likewise first be pushed onto the conductors 41, 42, or the connection cable 40, until the first and second crimping sleeves 44, 45 are deformed. Subsequently, the second sleeve portion 72 may then be pushed towards the first sleeve portion 71 and connected to it. It then also fixes the head element 56 of the insulator 50.

(21) In FIG. 3, a longitudinal section through an insulator 50 can be seen. In the longitudinal section there lies a through-hole 53, which is made up of a first, a second and a third portion A1, A2, A3. The portions A1, A2, A3 have two different diameters. The first portion A1, which is later arranged on the side of the carrier element 10, in particular with a resting surface 57, has a greater diameter than the second portion A2. The second portion A2 is arranged between the first and third portions A1, A3. In this case, the third portion A3 has a greater diameter than the second portion A2. In particular, the first and third portions A1, A3 have a diameter of the same size.

(22) In this way it is possible that the plastic deformations of the crimping sleeves on sides of the connection pins lie within the first portion A1, a middle region of the crimping sleeves without plastic deformation is arranged in the region of the second portion A2, and the plastic deformations of the crimping sleeves in the region of the conductors lie within the third portion A3. A stable connection is produced if the diameter of the second portion A2 is less than the diameter of the crimping sleeves in the region of the plastic deformations. For this purpose, the diameter of the second portion A2 should substantially correspond to the diameter of the crimping sleeves in the non-plastically-deformed region.

(23) To allow the whole thing to be assembled, the insulator 50 is made up of a standing element 55, which forms a base portion 52 with the resting surface 57, and a head element 56, which forms a neck portion 51. The standing element 55 carries the first and second portions A1, A2. It can be pushed on when the crimping sleeves have been connected to the connection pins. Subsequently, the crimping sleeves can be connected to connection conductors outside the standing element 55, before the head element is pushed over the deformation of the crimping sleeve.

(24) Suitable for commonly used heating outputs in injection-moulding technology are for example diameters of 1.60.10 mm for the first and third portions and of 1.15+0.10/0.05 mm for the second portion. A crimping sleeve with a diameter of 1.00 mm may be used here by way of example.

(25) FIG. 4 shows a perspective exploded representation of an injection-moulding nozzle 100 with a heating element 1. In particular, the heating element 100 is technically constructed in a way corresponding to the representation in FIG. 1. Therefore, with regard to the description of the heating element, reference is made to the foregoing description.

(26) The sleeve-shaped heating element 1 has been pushed onto a material tube 102 of the injection-moulding nozzle, which extends in the direction of the longitudinal axis L. As a result, the heating element 1 is thermally coupled to the material tube 102 for the heating of the flow channel 101. In an embodiment, a loose fit is formed between the material tube 102 and the sleeve-shaped heating element 1 at room temperature. At operating temperature of the heating element and of the material tube 102, a press fit should be formed. As a result, a good thermal coupling is achieved with at the same time easy 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 carrier element.

(27) It can also be seen that a housing 103 consisting of a housing head 105 and a housing shaft 106 is provided. Incorporated in the housing head 105 is a clearance 104 in the form of a lateral longitudinal slit, which is formed as open in the direction of the connection device 30.

(28) In the exploded representation shown, the material tube 102 with the heating element 1 has been pulled out from the housing shaft 106. Furthermore, the heating element 1 has not been pushed completely onto the material tube 102.

(29) The injection-moulding nozzle 100 is correctly assembled when the heating element 1 is pushed in the longitudinal direction L in the direction of the housing head 105, so that the connection device 30 protruding transversely in relation to the longitudinal direction is arranged within the lateral clearance 104 in the housing head 105. Furthermore, the housing shaft 106 should be pushed in the longitudinal direction L in the direction of the housing head 105, until the two butt against one another with opposite flange peripheries. The housing shaft 106 and the housing head 105 are subsequently fixed to one another with screws 107. The material tube 102 and the heating element 1 then lie substantially within the housing 103.

(30) Such an injection-moulding nozzle may be connected either to a central machine nozzle or to a manifold plate, in particular with the housing head 105. With the other end, the housing shaft 106 and the material tube 102 then protrude into a gate of a mould plate, in which a cavity for the forming of a component is formed (also referred to as mould impression).

(31) The invention is not restricted to one of the embodiments described above but can be modified in various ways.

(32) For instance, it is possible in particular to connect an earthing conductor of the connection cable 40 in an electrically conducting manner to the receiving sleeve 60. In particular, the earthing conductor of the connection cable 40 may be led out between the two sleeve portions 71, 72 and fixed in an electrically conducting manner, in particular lasered on, on the outer side of one of the sleeve portions 71, 72.

(33) Also conceivable is the use (not shown any further) of the heating element 1 in a mould impression (likewise not shown) of an injection-moulding tool, in order for example to heat a portion of the wall of the mould impression.

(34) All of the features and advantages that are disclosed by the claims, the description and the drawing, including structural design details, spatial arrangements and method steps, may be essential to the invention both on their own and in the widest variety of combinations.

Additional Description

(35) With reference to the figures, further embodiments are discussed:

(36) Embodiment 1 is a heating element (1) for heating a flow channel or a mould impression that has a carrier element (10), which carries a heating conductor (20) with a first connection pin (21) and a second connection pin (22), and that comprises a connection device (30) with an electrical connection cable (40) with a first and a second conductor (41, 42), wherein the first and second connection pins (21, 22) end in an insulator (50) of the connection device (30) that separates the first connection pin (21) electrically from the second connection pin (22), wherein the insulator (50) is arranged at least in certain portions in a receiving sleeve (60) of the connection device (30), and wherein the receiving sleeve (60) points with a first end (61) in the direction of the carrier element (10), is fixed with the first end (61) on the carrier element (10) and fixes the insulator (50) in relation to the carrier element (10), characterized in that a first crimping sleeve (44) is fixed on the first connection pin (21) and a second crimping sleeve (45) is fixed on the second connection pin (22), in each case by plastic deformation, and the first crimping sleeve (44) is fixed on the first conductor (41) and the second crimping sleeve (45) is fixed on the second conductor (42), in each case by plastic deformation.

(37) Embodiment 2 is the heating element (1) according to Embodiment 1, characterized in that the receiving sleeve (60) has a second end (62), which is opposite from the first end (61), forms a third crimping sleeve (63) and is fixed on the connection cable (40) by plastic deformation.

(38) Embodiment 3 is the heating element (1) according to either of Embodiment 1 and Embodiment 2, characterized in that the carrier element (10) is in the form of a tube or sleeve.

(39) Embodiment 4 is the heating element (1) according to any of Embodiment 1 to Embodiment 3, characterized in that the first end (61) of the receiving sleeve (60) reaches around the insulator (50) and has at this first end (61) two feet (64, 65) pointing outwards opposite from one another and fastened to the carrier element (10).

(40) Embodiment 5 is the heating element (1) according to any of Embodiment 1 to Embodiment 4, characterized in that the feet (64, 65) are adapted to the outer contour of the insulator (50) such that they follow the outer contour.

(41) Embodiment 6 is the heating element (1) according to any of Embodiment 1 to Embodiment 5, characterized in that the heating conductor (20) is applied to the carrier element (10) by film technology.

(42) Embodiment 7 is the heating element (1) according to any of Embodiment 1 to Embodiment 6, characterized in that the receiving sleeve (60) consists of metal.

(43) Embodiment 8 is the heating element (1) according to any of Embodiment 1 to Embodiment 7, characterized in that the insulator (50) has a neck portion (51) and a base portion (52), wherein the receiving sleeve (60) is supported on the base portion (52) of the insulator (50).

(44) Embodiment 9 is the heating element (1) according to any of Embodiment 1 to Embodiment 8, characterized in that an earthing conductor of the connection cable (40) is connected in an electrically conducting manner to the receiving sleeve (60).

(45) Embodiment 10 is the heating element (1) according to any of Embodiment 1 to Embodiment 9, characterized in that the insulator (50) has two through-holes (53, 54), wherein one of the first and second crimping sleeves (44, 45) is arranged in each through-hole (53, 54).

(46) Embodiment 11 is the heating element (1) according to Embodiment 10, characterized in that the through-holes (53, 54) are respectively formed by a first, a second and a third portion (A1, A2, A3), which have at least two different diameters.

(47) Embodiment 12 is the heating element (1) according to Embodiment 11, characterized in that the first portion (A1) is arranged on the side of the carrier element (10) and has a greater diameter than the second portion (A2), which lies between the first and third portions (A1, A3), and in that the third portion (A3) has a greater diameter than the second portion (A2), wherein the plastic deformations of the crimping sleeves (44, 45) in the region of the connection pins (21, 22) lie within the first portion (A1), a middle region of the crimping sleeves (44, 45) without plastic deformation is arranged in the region of the second portion (A2), and the plastic deformations of the crimping sleeves (44, 45) in the region of the conductors (41, 42) lie within the third portion (A3).

(48) Embodiment 13 is the heating element (1) according to any of Embodiment 1 to Embodiment 12, characterized in that the insulator (50) is formed in two parts, comprising a standing element (55), which stands on the carrier element (10), and a head element (56), which is positioned adjacent to the standing element (55) on the side opposite from the carrier element (10).

(49) Embodiment 14 is the heating element (1) according to any of Embodiment 1 to Embodiment 13, characterized in that the insulator (50) terminates with the crimping sleeves (44, 45) or protrudes beyond them.

(50) Embodiment 15 is the heating element (1) according to any of Embodiment 1 to Embodiment 14, characterized in that the receiving sleeve (60) consists of a first and a second sleeve portion (71, 72), which are welded to one another, wherein the first sleeve portion (71, 72) forms the first end (61) of the receiving sleeve (60).

(51) Embodiment 16 is an injection-moulding nozzle (100) with a flow channel (101) in a material tube (102), and with a heating element (1) according to any of Embodiment 1 to Embodiment 15 which for heating the flow channel (101) is thermally coupled to the material tube (102).

(52) Embodiment 17 is the injection-moulding nozzle (100) of Embodiment 16, further comprising a housing (103) consisting of a housing head (105) and a housing shaft (106), wherein the connection device (30) is arranged within a lateral clearance (104) in the housing head (105).

(53) Embodiment 18 is the injection-moulding nozzle (100) of Embodiment 17, wherein the lateral clearance (104) is a lateral longitudinal slit.

LIST OF DESIGNATIONS

(54) 1 Heating element 10 Carrier element 20 Heating conductor 21 First connection pin 22 Second connection pin 23 Electrically conducting thick film 24 First insulating layer 25 Second insulating layer 26 Clearance 30 Connection device 40 Connection cable 41 First conductor 42 Second conductor 44 First crimping sleeve 45 Second crimping sleeve 46 Protective jacket 47 Inner bevel 50 Insulator 51 Neck portion 52 Base portion 53 First through-hole 54 Second through-hole 55 Standing element 56 Head element 57 Resting surface 60 Receiving sleeve 61 First end (receiving sleeve) 62 Second end (receiving sleeve) 63 Third crimping sleeve 64 First foot 65 Second foot 66 Leg portion (first foot) 67 Leg portion (second foot) 68 Resting portion (first foot) 69 Resting portion (second foot) 70 Fastening means 71 First sleeve portion 72 Second sleeve portion 80 Thermocouple 100 Injection-moulding nozzle 101 Flow channel 102 Material tube 103 Housing 104 Clearance 105 Housing head 106 Housing shaft A1 First portion A2 Second portion A3 Third portion L Longitudinal direction (carrier element)