Heat-generating element of a heating device

• US 7,667,166 B2
• Filed: 09/22/2006
• Issued: 02/23/2010
• Est. Priority Date: 09/23/2005
• Status: Active Grant

• Current Assignee: Catem GmbH & Co., KG
• Original Assignee: Catem GmbH & Co., KG
• Inventors: Niederer, Michael, Bohlender, Franz, Walz, Kurt, Zeyen, Michael
• Primary Examiner(s): Campbell; Thor S
• Application Number:
  US11/534,387
• Publication Number:
  US 20070068913A1
• Time in Patent Office: 1,250 Days
• Field of Search: 219/202, 219/504, 219/505, 219/520, 219/536, 219/537, 219/540, 219/541, 219/544, 219/548, 219/533, 392/347, 392/380, 156/291, 156/292
• US Class Current: 219/552
• CPC Class Codes: F24H 3/0405 using electric energy supply, e.g. the heating medium being a resistive element; Heating by direct contact, i.e. with resistive elements, electrodes and fins being bonded together without additional element in-between F24H3/06, F24H3/08, F24H3/10 take precedence
• CPC Class Codes: F24H 3/0429 For vehicles
• CPC Class Codes: F24H 3/0435 Structures comprising heat spreading elements in the form of fins
• CPC Class Codes: F24H 3/0447 Forms of the electrode terminals, e.g. tongues or clips
• CPC Class Codes: F24H 3/0464 Two-piece frames, e.g. two-shell frames, also including frames as a central body with two covers
• CPC Class Codes: F24H 3/0476 Means for putting the electric heaters in the frame under strain, e.g. with springs
• CPC Class Codes: F24H 3/082 The tubes being an electrical isolator containing the heater
• CPC Class Codes: F24H 9/1872 PTC
• CPC Class Codes: H05B 2203/02 Heaters using heating elements having a positive temperature coefficient
• CPC Class Codes: H05B 2203/023 Heaters of the type used for electrically heating the air blown in a vehicle compartment by the vehicle heating system
• CPC Class Codes: H05B 3/50 heating conductor arranged in metal tubes, the radiating surface having heat-conducting fins

Abstract

A heat-generating element of a heating device for heating air includes at least one PTC element and, lying on opposing side surfaces of the PTC element, electric strip conductors. A heat-generating element that is improved with a view to safety from electric flashovers and leakage currents is created with the invention under consideration by providing an insulating gap between the PTC element and the positioning frame material that circumferentially surrounds the frame opening. Also disclosed is a heating device for heating air with multiple heat-generating elements, each heat-generating element comprising at least one PTC element and, lying on opposing side surfaces of the PTC element, electric strip conductors and multiple heat-emitting elements that are arranged in parallel layers and that are held in position in a frame on opposing sides of the heat-generating element with a spring bias. Due to the use of a heat-generating element, the heating device is protected from electric flashovers and leakage currents with a higher degree of certainty.

Claims

1. A heat-generating element of a heating device for heating air, comprising:

at least one PTC element and a positioning frame which forms at least one frame opening for holding the at least one PTC element, wherein

the PTC element is supported in the positioning frame in a highly insulating manner and, wherein an insulating gap is provided between the PTC element and a portion of the positioning frame that circumferentially surrounds the frame opening, wherein an edge that circumferentially surrounds the frame opening supports an insulating strip and the insulating strip comprises a closed insulating frame that circumferentially lines the frame opening, and wherein the positioning frame forms a tongue that meshes in a retaining groove that is cut into a spacing medium that extends about the frame opening.

2. The heat-generating element according to claim 1, wherein the insulating gap prevents the PTC element from coming into direct contact with the positioning frame, and providing a dielectric strength suitable to prevent electric flashover within the heat generating element when subjected to a high voltage potential.

3. The heat-generating element according to claim 1, wherein at least one of the insulating spacing medium and the positioning frame is formed from an electrically high-grade insulating material.

4. Heat-generating element according to claim 3, wherein the high-grade insulating material is silicone.

5. The heat-generating element according to claim 1, wherein electric strip conductors lie against opposing side surfaces of the PTC element and the insulating gap continues between the electric strip conductors and the material of the positioning frame.

6. The heat-generating element according to claim 1, wherein the PTC element is connected to an electric strip conductor and, via insulating placement of the electric strip conductor with respect to the positioning frame, is arranged in such a way that an air gap is provided between the PTC element and the material of the positioning frame, said material circumferentially surrounding the frame opening.

7. The heat-generating element according to claim 6, wherein the air gap is surrounded by an insulating padding element.

8. The heat-generating element according to claim 7, wherein the electric strip conductors lies against the positioning frame either directly or via an insulating layer that is arranged on the exterior side of the electric strip conductor and that projects beyond the electric strip conductor, with a sealing element placed in between.

9. The heat-generating element according to claim 8, wherein the sealing element is formed by a plastic adhesive that connects the insulating layer to the positioning frame.

10. The heat-generating element according to claim 8, wherein the sealing element is formed as a single piece with the positioning frame as an injection-molded part.

11. The heat-generating element according to claim 10, wherein the sealing element extends at least in lengthwise direction of the positioning frame.

12. The heat-generating element according to claim 10, wherein the sealing element is arranged adjacent to a sealing medium edge that is formed by the positioning frame and that extends at least along the length of the positioning frame.

13. The heat-generating element according to claim 1, wherein the positioning frame forms bordering edges extending at a right angle to a supporting plane of the PTC element and bordering sides of an accommodation of the insulating layer.

14. The heat-generating element according to claim 5, wherein the positioning frame forms bordering edges extending at a right angle to a supporting plane of the PTC element and bordering sides of an accommodation of the electric strip conductor.

15. The heat-generating element according to claim 3, wherein the positioning frame is formed as a plastic injection-molded part from an insulating material and wherein the spacing medium is arranged on the positioning frame by molding around a highly insulating plastic component.

16. The heat-generating element according to claim 7, wherein the positioning frame is formed as a plastic injection-molded part from an insulating material and the sealing element is arranged on the positioning frame by molding around a highly insulating plastic component.

17. A heat-generating element of a heating device for heating air, comprising:

at least one PTC element and a positioning frame which forms at least one frame opening for holding the at least one PTC element, wherein

the PTC element is supported in the positioning frame in a highly insulating manner and, wherein an insulating gap is provided between the PTC element and a portion of the positioning frame that circumferentially surrounds the frame opening, and wherein the positioning frame forms pegs that extend at right angles to the supporting plane of the PTC element, said pegs meshing with cuts formed in electric strip conductors and forming a thickening formed by melting, via of which the electric strip conductors are secured to the positioning frame.

18. The heat generating element according to claim 17, wherein, on one side of the positioning frame, at least one electric strip conductor is connected to the positioning frame by molding around the highly insulating material that forms the positioning frame.

19. The heat-generating element according to claim 17, wherein an insulating layer is provided adjacent to an electric strip conductor and is connected to the positioning frame by molding around it.

20. A heat-generating element of a heating device for heating air, comprising:

a positioning frame having an inner circumferential edge defining a frame opening;

a PTC element held within the frame opening of the positioning frame;

an insulating gap, defined between the PTC element and the inner circumferential edge of the positioning frame supporting the PTC element in a highly insulating manner;

first and second electric strip conductors extending parallel to each other and lying on opposing sides of the PTC element, at least one of the first and second electric strip conductors being displaced from the positioning frame; and

an insulating layer covering and projecting laterally beyond an exterior side of at least one of the first and second electric strip conductors, and further comprising a sealing element provided between the positioning frame and the insulating layer, ensuring the positioning frame and the insulating layer remain insulated from each other.