Electrical heating device, method for the production thereof, and vehicle seat with such a heating device

Abstract

An electrical heating device includes at least one support; at least one ohmic heating resistor; and at least one temperature sensor. The heating resistor includes a heating conductor strand, which is laid out on, or in, the support in a track-like, curving, or meandering pattern to span a heating field. The heating conductor strand includes a measurement loop formed by at least two heating conductor sections that are separated from one another, and, in each case, are connected together electrically conductively at one end, and which are laid out around the temperature sensor and form a delimited measurement field. The temperature sensor is placed in a measurement position within the measurement field spanned by the measurement loop so that it is positioned as a function of a surface area formed by the measurement field at a greater or smaller distance from an opening of the measurement loop.

Claims

1. An electrical heating device comprising: a. at least one support; b. at least one ohmic heating resistor; and c. at least one temperature sensor; wherein the at least one ohmic heating resistor comprises at least one heating conductor strand, the at least one heating conductor strand is laid out on, or in, the at least one support in a track-like, curving, or meandering pattern in order to span a heating field, wherein the at least one heating conductor strand comprises at least one measurement loop, which is formed by two straight heating conductor strand sections that are separated from one another and connected together electrically conductively at one end, the two straight heating conductor strand sections are laid out around the at least one temperature sensor and thereby form a delimited measurement field, wherein the at least one temperature sensor is placed in a measurement position within the delimited measurement field spanned by the at least one measurement loop in such a way that the at least one temperature sensor: i. has approximately a same distance from the two straight heating conductor strand sections of the at least one measurement loop, and ii. is positioned within the at least one measurement loop as a function of a surface area formed by the delimited measurement field.

2. The electrical heating device according to claim 1, wherein the delimited measurement field spans the surface area having a defined magnitude, and wherein depending on the defined magnitude of the surface area of the delimited measurement field, a certain position in the surface area of the delimited measurement field is associated with the at least one temperature sensor.

3. The electrical heating device according to claim 1, wherein the at least one temperature sensor is arranged approximately equidistantly between the two straight heating conductor strand sections, and wherein a distance from a section connecting the two straight heating conductor strand sections or from an opening formed between the two straight heating conductor strand sections is a function of the surface area of the delimited measurement field.

4. The electrical heating device according to claim 1, wherein the two straight heating conductor strand sections that form the delimited measurement field are oriented at least approximately parallel to one another or parallel to one another in at least some sections.

5. The electrical heating device according to claim 1, wherein the two straight heating conductor strand sections that form the delimited measurement field are arranged at a distance which is between 4 mm and 10 mm from one another.

6. The electrical heating device according to claim 1, wherein the at least one temperature sensor is formed as an NTC sensor which is narrowly localized spatially.

7. The electrical heating device according to claim 1, wherein the at least one heating conductor strand and/or the at least one temperature sensor is/are sewn into the at least one support.

8. The electrical heating device according to claim 1, wherein the at least one temperature sensor comprises a plurality of temperature sensors that are attached in two or more positions within the electrical heating device.

9. The electrical heating device according to according to claim 1, wherein a correlation between a temperature measurement value delivered by the at least one temperature sensor and an actual temperature averaged over the surface area of the heating field corresponds to the delimited measurement field that is matched to an individual heating device.

10. A heatable vehicle seat having a seat pad and/or a backrest pad, wherein at least the seat pad and/or the backrest pad is/are provided with the electrical heating device according to claim 1 which forms a seat heater of the vehicle seat.

11. A method for production of the electrical heating device according to claim 1 comprising: arranging the at least one heating conductor strand in a curving or meandering pattern in at least some sections; and acquiring a magnitude of a distance and/or a surface area between the two straight heating conductor strands that form the delimited measurement field; and fixing the at least one temperature sensor in a defined position within the delimited measurement field as a function of the acquired magnitude.

12. The method according to claim 11, wherein the method includes a step of acquiring by means of a camera system, an exact pattern of the two straight heating conductor strand sections forming the heating conductor loop.

13. The method according to claim 11 wherein a target position of the at least one temperature sensor within the delimited measurement field is indicated by means of a light spot, in particular, by means of a laser pointer, which gives a manual, partially automatic or automatic positioning of the at least one temperature sensor within the electrical heating device.

14. The electrical heating device according to claim 1, wherein the at least one measurement loop has a parabolic shape.

15. The electrical heating device according to claim 1, wherein the two straight heating conductor strand sections are spaced apart by a distance of 7 mm, and a sensor head of the at least one temperature sensor is placed at a depth of 21 mm from the opening of the at least one measurement loop.

16. The electrical heating device according to claim 1, wherein the two straight heating conductor strand sections are spaced apart by a distance of 6 mm, and a sensor head of the at least one temperature sensor is placed at a depth of 19 mm from the opening of the at least one measurement loop.

17. The electrical heating device according to claim 1, wherein the two straight heating conductor strand sections are spaced apart by a distance of 8 mm, and a sensor head of the at least one temperature sensor is placed at a depth of 23 mm from the opening of the at least one measurement loop.

18. An electrical heating device comprising: a. at least one support; b. at least one ohmic heating resistor; and c. at least one temperature sensor; wherein the at least one ohmic heating resistor comprises at least one heating conductor strand, the at least one heating conductor strand is laid out on or in the at least one support in a track-like, curving or meandering pattern in order to span a heating field, wherein the at least one heating conductor strand comprises at least one measurement loop, which is formed by at least two straight heating conductor strand sections that are separated from one another and connected together electrically conductively at one end, and which are laid out around the at least one temperature sensor and thereby form a delimited measurement field, wherein the at least one temperature sensor is placed in a measurement position within the delimited measurement field spanned by the at least one measurement loop in such a way that the at least one temperature sensor: i. has approximately same distances between the at least two straight heating conductor strand sections of the at least one measurement loop, and ii. as a function of a surface area formed by the delimited measurement field, the at least one temperature sensor is positioned at a larger distance from an opening of the at least one measurement loop, wherein a distance from a section connecting the at least two straight heating conductor strand sections or from an opening formed between the at least two straight heating conductor strand sections is variable as a function of the surface area of the delimited measurement field, wherein the at least two straight heating conductor strand sections that form the delimited measurement field are oriented at least approximately parallel to one another or parallel to one another in at least some sections, wherein sections of the at least two straight heating conductor strand sections that form the delimited measurement field are arranged at a distance between 6 mm and 8 mm from one another, wherein the at least one heating conductor strand and/or the at least one temperature sensor, is/are sewn into the at least one support, and wherein a correlation between a temperature measurement value delivered by the at least one temperature sensor and an actual temperature averaged over the surface area of the heating field corresponds to an individual electrical heating device.

Description

BRIEF DESCRIPTION OF THE DRAWINGS

(1) FIG. 1 shows a diagrammatic top view of an embodiment variant of an electrical heating device according to the invention.

(2) FIG. 2A shows an enlarged section of a detail from FIG. 1.

(3) FIG. 2B shows a detailed view of a placement of a temperature sensor.

(4) FIG. 2C shows an additional detailed view of a placement of the temperature sensor.

(5) FIG. 2D shows an additional detailed view of the placement of the temperature sensor.

(6) FIG. 3 shows a chart of the method to illustrate the required method steps in the production of the electrical heating device.

DETAILED DESCRIPTION

(7) This application claims priority to and the benefit of German Application DE102015004872.4, filed on Apr. 17, 2015, the disclosure of which is hereby incorporated by reference herein in its entirety for all purposes.

(8) In the diagrammatic representation of FIG. 1, a seat area of a vehicle seat 10 is indicated. In the inside area, in a support 12 which forms an inner seat area, an electrical heating device 14 in the form of a seat heater 15 is installed. The electrical heating device 14 forming the seat heater 15 is spanned by a plurality of heating conductor strands 16 connected together. For an ideal operation, the heating conductor strands 16 form so-called heating conductor loops 18. At least one of these heating conductor loops 18 is used as measurement loop in which a measurement field 20 is spanned. In the measurement field 20, a temperature sensor 22 is to be placed, which is in the form of an NTC sensor comprising an NTC sensor head 24 on which the temperatures within the seat heater 15 are measured. This can be seen in the enlarged representation in FIG. 2A.

(9) Ideally, the heating conductor loop 18 is spanned by parallel heating conductor strands 16 at a separation distance of approximately 7 mm for example, as represented in FIG. 2B. A camera system that is not shown acquires the exact course of the heating conductor strands 16 and calculates via software an ideal fastening position for the installation of the temperature sensor 22 or of NTC sensor. The NTC sensor head 24, in the case of this acquired separation distance of the heating conductor strands 16 of 7 mm, is ideally placed at a depth of 21 mm in the measurement field 20, measured from the opening 26 of the heating conductor loop 18, which is located in each case at the bottom in the representations of FIGS. 2A-2D. By means of the spot of a laser pointer, this fastening position is represented as a reference point for the attachment of the temperature sensor 22 or NTC sensor. The temperature sensor 22 or NTC sensor can subsequently be manually attached rapidly and simply, and is ideally positioned in the measurement field 20 in order to acquire temperature measurement values by means of which the actual temperature of the seat heater 15 can be calculated. In this manner, an ideal setting of the temperature of the seat heater 15 is made possible.

(10) FIG. 2C represents another possible case. Here, the separation distance of the parallel heating conductor strands 16 in the heating conductor loop 18 is only 6 mm. The camera system again acquires the exact course of the heating conductor strands 16 and calculates the ideal fastening position for the attachment of the NTC sensor 22, which comprises the NTC sensor head 24 which is now located at a depth of 19 mm in the measurement field 20, measured again from the lower opening 26 of the loop 18. As a result of this procedure, it is ensured, in spite of the smaller heating conductor loop 18, that the NTC sensor 22 is uniformly heated by the heating conductor strands 16, as in the ideal case described in FIG. 2B. As a result, an incorrect calculation of the actual temperature of the seat heater 15 is avoided.

(11) FIG. 2D shows a case in which the separation distance of the parallel heating conductor strands 16 in the heating conductor loop 18 assumes a value of 8 mm, for example, which is thus greater than in the ideal case. After the camera system has acquired the exact course of the heating conductor strands 16, the result is an ideal fastening position for the attachment of the NTC sensor 22 of 23 mm in the measurement field 20, measured from the lower opening 26 of the loop 18. Thus, in this case as well, an ideal heatingdescribed in FIG. 2Bof the NTC sensor 22 is ensured.

(12) FIG. 3 shows a chart of the method for illustrating the method of production of the electrical heating device 14 according to the invention. In the first step 30, the method comprises a process in which at least one heating conductor strand 16 is laid out in a meandering arrangement. Subsequently, in the following step 32, the magnitude of surface area between two directly adjacent heating conductor strands is acquired. In the third step 34, the temperature sensor 22 is fixed in a defined position, which has been determined as a function of the acquired magnitude.

(13) The invention has been described in reference to a preferred embodiment. However, it is conceivable to a person skilled in the art that deviations or changes can be made to the invention without thereby leaving the scope of protection of the following claims.

LIST OF REFERENCE NUMBERS

(14) 10 Vehicle seat

(15) 12 Support

(16) 14 Electrical heating device

(17) 15 Seat heater

(18) 16 Heating conductor strand

(19) 18 Heating conductor loop

(20) 20 Measurement field

(21) 22 Temperature sensor, NTC sensor

(22) 24 NTC sensor head

(23) 26 Opening

(24) 30 Step 1

(25) 32 Step 2

(26) 34 Step 3