PTC HEATING MODULE

Abstract

A PTC heating module for heating a fluid may include two contact plates between which at least one cuboid PTC thermistor is arranged and at least one contact socket with a contact side. The PTC thermistor may have two main sides disposed opposite each other and defining a thermistor thickness therebetween. The contact side of the at least one contact socket may rest against a first main side of the at least one PTC thermistor and another side may rest against a first contact plate. A geometric contact surface between the first main side and the contact side of the at least one contact socket may be smaller than a geometric surface of the first main side. A clearance distance extending between the two contact plates and a creapage distance extending from the at least one contact socket to a second contact plate may be larger than the thermistor thickness.

Claims

1. A PTC heating module for heating a fluid, comprising: at least one cuboid PTC thermistor with two main sides disposed opposite each other, which are spaced apart from one another and define a thermistor thickness of the at least one PTC thermistor therebetween; two contact plates, between which the at least one PTC thermistor is arranged and with which the at least one PTC thermistor is electrically contacted; at least one contact socket with a contact side, the at least one contact socket resting on one side electrically conductively with the contact side against a first main side of the two main sides of the at least one PTC thermistor and on an other side resting electrically conductively against a first contact plate of the two contact plates; wherein a thickness of the at least one contact socket provides a distance between the two contact plates that is enlarged and a geometric contact surface between the first main side of the at least one PTC thermistor and the contact side of the at least one contact socket is smaller than a geometric surface of the first main side of the at least one PTC thermistor such that a clearance distance extending between the two contact plates and a creapage distance extending from the at least one contact socket to a second contact plate of the two contact plates is larger than the thermistor thickness of the at least one PTC thermistor.

2. The PTC heating module according to claim 1, wherein: the at least one contact socket includes two contact sockets each having a respective contact sides, the two contact sockets respectively resting on one side electrically conductively with the respective contact side against one of the two main sides of the at least one PTC thermistor and on a respective other side resting electrically conductively against one of the two contact plates; and a second creapage distance extending between the two contact sockets is larger than the thermistor thickness of the at least one PTC thermistor.

3. The PTC heating module according to claim 1, wherein: a width of the first main side of the at least one PTC thermistor defining the geometric surface is larger than a width of the contact side of the at least one contact socket defining a geometric surface; and the at least one PTC thermistor protrudes on both sides from the at least one contact socket in a width direction such that the creapage distance extending between the at least one contact socket and the second contact plate is larger than the thermistor thickness of the at least one PTC thermistor.

4. The PTC heating module according to claim 1, wherein: a length of the first main side of the at least one PTC thermistor defining the geometric surface is larger than a length of the contact side of the at least one contact socket defining a geometric surface; and the at least one PTC thermistor protrudes on both sides from the at least contact socket in a longitudinal direction such that the creapage distance extending between the at least one contact socket and the second contact plate is larger than the thermistor thickness of the at least one PTC thermistor.

5. The PTC heating module according to claim 1, wherein: an electrically conducting coating is coupled on the first main side of the at least one PTC thermistor and is arranged between the contact side of the at least one contact socket and the first main side of the at least one PTC thermistor; and a geometric surface of the coating corresponds to the geometric contact surface.

6. The PTC heating module according to claim 1, wherein the at least one contact socket is provided integrally with the first contact plate.

7. The PTC heating module according to claim 1, wherein a geometric cross-sectional area of the at least one contact socket increases one of consistently and in stages from the contact side in a direction of the first contact plate.

8. The PTC heating module according to claim 1, wherein: one of the two contact plates defines a first housing part and the other of the two contact plates defines a second housing part electrically insulated from the first housing part; and the first housing part and the second housing part define a housing encasing the at least one PTC thermistor.

9. The PTC heating module according to claim 8, wherein the housing is electrically insulated, at least in sections, by an insulating layer facing towards an outside.

10. The PTC heating module according to claim 8, wherein the housing is filled, at least in sections, with a heat-conducting and electrically insulating material.

11. The PTC heating module according to claim 1, wherein the at least one contact socket includes two contact sockets arranged on the at least one PTC thermistor, which respectively rest against one of the two main surfaces of the at least one PTC thermistor via a respective contact side.

12. The PTC heating module according to claim 1, wherein the at least one PTC thermistor includes a plurality of PTC thermistors which, in a longitudinal direction, are arranged next to one another between the two contact plates and are electrically contacted by the two contact plates.

13. The PTC heating module according to claim 1, wherein at least one of the creapage distance and the clearance distance is 110% to 500% of the thermistor thickness of the at least one PTC thermistor.

14. The PTC heating module according to claim 1, wherein the creapage distance and the clearance distance is 110% to 500% of the thermistor thickness of the at least one PTC thermistor.

15. A PTC heating module for heating a fluid, comprising: at least one cuboid PTC thermistor having two main sides facing opposing directions and a thermistor thickness extending between the two main sides; a first contact plate and a second contact plate between which the at least one PTC thermistor is arranged and with which the at least one PTC thermistor is electrically contacted; a first contact socket arranged between the at least one PTC thermistor and the first contact plate, the first contact socket having a thickness and a contact side electrically conductively contacting a first main side of the two main sides; a second contact socket arranged between the at least one PTC thermistor and the second contact plate, the second contact socket having a thickness and a contact side electrically conductively contacting a second main side of the two main sides; wherein: a geometric contact surface between the first main side and the contact side of the first contact socket is smaller than a geometric surface of the first main side; a geometric contact surface between the second main side and the contact side of the second contact socket is smaller than a geometric surface of the second main side; and a clearance distance extending between the first contact plate and the second contact plate, a first creapage distance extending from the first contact socket to the second contact plate, and a second creapage distance extending from the second contact socket to the first contact plate are larger than the thermistor thickness.

16. The PTC heating module according to claim 15, wherein a third creapage distance extending between the first contact socket and the second contact socket is larger than the thermistor thickness.

17. The PTC heating module according to claim 15, wherein: one of the first contact plate and the second contact plate defines a first housing part and the other of the first contact plate and the second contact plate defines a second housing part, the second housing part electrically insulated from the first housing part; and the first housing part and the second housing part define a housing encasing the at least one PTC thermistor.

18. The PTC heating module according to claim 17, further comprising an electrically insulating layer disposed on an exterior surface of the housing facing away from the at least one PTC thermistor.

19. The PTC heating module according to claim 17, wherein the housing is at least partially filled with a heat-conducting and electrically insulating material.

20. A PTC heating module for heating a fluid, comprising: a plurality of cuboid PTC thermistors each having two main sides facing opposing directions and a thermistor thickness extending between the two main sides; two contact plates between which the plurality of PTC thermistors are arranged next to one another and with which the plurality of PTC thermistors are electrically contacted; a plurality of contact sockets respectively arranged between a corresponding PTC thermistor of the plurality of PTC thermistors and a corresponding contact plate to the two contact plates, the plurality of contact sockets respectively having a thickness and a contact side electrically conductively contacting a corresponding main side of the two main sides of the corresponding PTC thermistor; wherein a geometric contact surface between the contact side and the corresponding main side is smaller than a geometric surface of the corresponding main side; and wherein a clearance distance extending between the two contact plates and a creapage distance extending from the plurality of contact sockets to a non-corresponding contact plate of the two contact plates are larger than the thermistor thickness.

Description

BRIEF DESCRIPTION OF THE DRAWINGS

[0022] Preferred exemplary embodiments of the invention are depicted in the drawings and explained in detail in the description hereunder, wherein identical reference symbols refer to identical or similar or functionally identical components, in which, schematically,

[0023] FIG. 1 shows a sectional view of a PTC heating module according to the invention in a first embodiment;

[0024] FIGS. 2 to 5 show further sectional views of the PTC heating module according to the invention in the first embodiment;

[0025] FIG. 6 shows a sectional view of a PTC heating module according to the invention in a second embodiment;

[0026] FIGS. 7 to 10 show further sectional views of the PTC heating module according to the invention in the second embodiment;

[0027] FIG. 11 shows a sectional view of a PTC heating module according to the invention of a third embodiment;

[0028] FIGS. 12 to 15 show further sectional views of the PTC heating module according to the invention in the third embodiment;

[0029] FIG. 16 shows a view of contacting plates in the third embodiment of the PTC heating module;

[0030] FIG. 17 shows a sectional view of a PTC heating module with a two-part housing.

DETAILED DESCRIPTION

[0031] FIGS. 1 to 5 show sectional views of a PTC heating module 1 according to the invention in a first embodiment. The PTC heating module 1 according to the invention defines a longitudinal direction LR and a width direction BR which are at right angles to one another. FIG. 1 shows a sectional view of the PTC heating module 1 vertically to the width direction BR. FIG. 2 and FIG. 3 are sectional views of the PTC heating module 1 through a plane respectively defined by the longitudinal direction LR and the width direction BR. FIG. 4 shows a sectional view of the PTC heating module 1 at right angles to the longitudinal direction LR of the PTC heating module 1. In FIG. 5 an enlarged cut-out of the PTC heating module 1 from FIG. 4 is shown. Basically the thickness of the individual elements in the PTC heating module 1 is determined vertically to a plane defined by the longitudinal direction LR and width direction BR. Further the length of individual elements in the PTC heating module 1 is determined in longitudinal direction LR and the width of individual elements in the PTC heating module 1 is determined in width direction BR.

[0032] The PTC heating module 1 according to the invention is provided for heating a fluid such as air or coolant in a hybrid or electric vehicle. The PTC heating module 1 comprises a number of PTC thermistors 2 with respectively two main sides 3a and 3b opposite each other, which are spaced apart and define a thermistor thickness D.sub.PTC of the respective PTC thermistor 2. The PTC heating module 1 further comprises two contact plates 4a and 4b, between which the respective PTC thermistor 2 is arranged. The respective PTC thermistors 2 are affixed next to each other in longitudinal direction LR between the two contact plates 4a and 4b.

[0033] In the first embodiment the PTC heating module 1 comprises a contact socket 5a with a contact side 6a, the contact socket 5a on one side resting electrically conductively with its contact side 6a against the one main side 3a of the respective PTC thermistor 2 and on the other side resting electrically conductively against the one contact plate 4a. The contact socket 5a has a thickness D.sub.S,A, which increases a distance between the contact plates 4a and 4b. With its contact side 6a the contact socket 5a rests full-surface against the main side 3a of the respective PTC thermistor 2, so that a geometric contact surface F.sub.K,A between the main side 3a of the respective PTC thermistor 2 and the contact side 6a of the contact socket corresponds to a geometric surface F.sub.S,A of the contact side 6a. The geometric contact surface F.sub.K,A and the geometric surface F.sub.S,A of the contact side 6a of the contact socket 5a are smaller than the geometric surface F.sub.PTC of the main side 3a of the respective PTC thermistor 2. The width B.sub.PTC of the main side 3a of the respective PTC thermistor 2 which defines the geometric surface F.sub.PTC is larger than a width B.sub.S,A of the contact side 6a of the contact socket 5a, which defines a geometric surface F.sub.S,A. Further a length L.sub.PTC of the main side 3a of the respective PTC thermistor 2 which defines the geometric surface F.sub.PTC is larger than a length L.sub.S,A of the contact side 6a of the contact socket 5a which defines the geometric surface F.sub.S,A. As a result the respective PTC thermistor 2 is protruding from the contact socket 5a in both longitudinal direction LR and in width direction BR. This leads to a clearance distance 7a between the contact plates 4a and 4b and a creapage distance 7b between the contact socket 5a and the contact plate 4b being larger than the thermistor thickness D.sub.PTC of the PTC thermistor 2. The clearance distance 7a between the two contact plates 4a and 4b is defined by the shortest distance and thus by the distance of the two contact plates 4a and 4b from each other. The creapage distance 7b between the contact socket 5a and the contact plate 4b is defined by the shortest distance along the surface of the PTC thermistor 2 between the contact socket 5a and the contact plate 4b. The creapage distance 7b in longitudinal direction LR according to FIG. 1 and in width direction BR according to FIG. 4 are identical in this embodiment, but can also differ. It is provided that the creapage and/or clearance distances 7a and 7b lies over 100%, especially between 110% and 500%, especially between 120% and 300%, of the thermistor thickness D.sub.PTC of the respective PTC thermistor 2.

[0034] The contact socket 5a and the contact plates 4a and 4b are conveniently electrically conducting, so that the respective PTC thermistor 2 can be electrically connected through the contact socket 5a and the contact plate 4a to a positive pole and through the contact plate 4b to a negative pole, or vice versa. Further conveniently the contact plates 4a and 4b and the contact socket 5a are heat-conducting, so that the heat generated in the respective PTC thermistor 2 can be effectively dissipated to outside via the contact plates 4a and 4b and the contact socket 5a. In order to reduce the contact resistance between the contact socket 5a and the respective PTC thermistor 2, the PTC heating module 1 comprises an electrically conducting coating 8a, which is arranged between the main side 3a of the PTC thermistor 2 and the contact side 6a of the contact socket 5a. The coating 8a may for example consist of silver or another metal. The coating 8a can be arranged on the main side 3a of the PTC thermistor 2 and the PTC thermistor 2 with the coating 8a can be fixed to the contact socket 5a cohesively by soldering or gluing or mechanical by pressing. Basically a thickness of the coating 8a is low, so that the contact plate 4a and the PTC thermistor 2 have a distance from each other which is approx. equal to the thickness D.sub.S,A of the contact socket 5a. A geometric surface F.sub.B,A of the coating 8a corresponds, i.e. with a deviation of up to 15%, to the the geometric surface F.sub.S,A of the contact side 6a of the contact socket 5a, so that the creapage distance 7b between the contact socket 5a and the contact plate 4b is not shortened. The PTC heating module 1 comprises further an electrically conducting coating 12b, which is arranged on the main side 3b of the PTC thermistor 2. The PTC thermistor 2 with the coating 12b can be fixed to the contact plate 4b in the same manner as on the contact socket 5a. The coating 12b may for example consist of silver or another metal. Basically a thickness of the coating 12b is low, so that the contact plate 4b and the PTC thermistor 2 have a distance from each other which is negligible small.

[0035] In the PTC heating module 1 the distance and thus the clearance distance 7a between the two contact plates 4a and 4b can be adapted to a specified voltage, not by the thermistor thickness D.sub.PTC, but by the thickness D.sub.S,A of the contact socket 5a. The creapage distance 7b can also be adapted by the contact surface F.sub.K,A. The thermistor thickness D.sub.PTC of the respective PTC thermistor 2 is therefore independent of the specified voltage and can be advantageously reduced, in comparison to conventional solutions.

[0036] FIGS. 6 to 10 show sectional views of the PTC heating module 1 according to the invention in a second embodiment. FIG. 6 shows a sectional view of the PTC heating module 1 vertically to the width direction BR. In FIG. 7 and FIG. 8 sectional views of the PTC heating module 1 are shown through a plane defined by the longitudinal direction LR and width direction BR. FIG. 9 shows a sectional view of the PTC heating module 1 vertically to the longitudinal direction LR of the PTC heating module 1. In FIG. 10 an enlarged cut-out of the PTC heating module 1 from FIG. 9 is shown. Here again the thickness of individual elements in the PTC heating module 1 is determined vertically to a plane defined by the longitudinal direction LR and the width direction BR. The length of individual elements in the PTC heating module 1 and the width thereof are defined correspondingly in longitudinal direction LR/in width direction BR. Next the differences between the two embodiments of the PTC heating modules 1 will be separately discussed. In other respects the construction of the PTC heating module 1 is identical in both embodiments.

[0037] In the second embodiment of the PTC heating module a contact socket 5b is arranged between the PTC thermistor 2 and the contact plate 4b. The contact socket 5b rests with one contact side 6b against the main side 3b of the respective PTC thermistor 2. In addition an electrically conducting coating 8b is arranged between the main side 3b of the PTC thermistor 2 and the contact side 6b of the contact socket 5b. The construction and arrangement of the contact socket 5b substantially corresponds to the construction and arrangement of the contact socket 5a on the PTC thermistor 2. In difference to the first embodiment of the PTC heating module 1 here the distance between the two contact plates 4a and 4b and thus the clearance distance 7a is composed of the thermistor thickness D.sub.PTC of the PTC thermistor 2 and the respective thicknesses D.sub.S,A and D.sub.S,B of the contact sockets 5a and 5b. Here too, a thickness of the coating 8b is negligibly small. In this exemplary embodiment the thicknesses D.sub.S,A and D.sub.S,B of the two contact sockets 5a and 5b are identical, but they may be different from one another. The respective geometric contact surfaces F.sub.K,A and F.sub.K,B in this embodiment of the PTC heating module 1 also corresponds to the respective geometric surfaces F.sub.S,A and F.sub.S,B of the contact socket 5a and 5b and are respectively smaller than the geometric surfaces F.sub.PTC of the respective main sides 3a and 3b of the respective PTC thermistor 2, so that a creapage distance 7c between the two contact socket 5a and 5b is larger than the thermistor thickness D.sub.PTC. The creapage distance 7c between the contact sockets 5a and 5b is defined by the shortest distance along the surface of the PTC thermistor 2 between the contact sockets 5a and 5b. In this embodiment, the creapage distance 7c in longitudinal direction LR according to FIG. 1 and in width direction BR according to FIG. 4 are identical, but can also differ.

[0038] FIGS. 11 to 15 show sectional views of the PTC heating module 1 according to the invention in a third embodiment. FIG. 11 shows a sectional view of the PTC heating module 1 vertically to the width direction BR. In FIG. 12 and FIG. 13 sectional views of the PTC heating module 1 are shown through a plane defined respectively by a longitudinal direction LR and a width direction BR. FIG. 14 shows a sectional view of the PTC heating module 1 vertically to the longitudinal direction LR of the PTC heating module 1. FIG. 15 shows an enlarged cut-out of the PTC heating module 1 shown in FIG. 14. FIG. 16 shows a view of the contact plates 4a and 4b of the PTC heating module 1. Corresponding to the above definition here too the thickness of individual elements in the PTC heating module 1 is determined vertically to a plane defined by the longitudinal direction LR and width direction BR. The length and width of individual elements in the PTC heating module 1 are defined in longitudinal direction LR and width direction BR. Next the differences between the two embodiments of PTC heating modules 1 will be separately discussed. In other respects the construction of the PTC heating module 1 is identical in both embodiments.

[0039] In the third embodiment of the PTC heating module 1 the respective PTC thermistors 2 are electrically contacted by a common contact socket 5a with the contact plate 4a. The contact socket 5a is formed integrally with the contact plate 4a. The common contact plate 5a extends in longitudinal direction and the contact side 6a of the contact socket 5a rests against the main side 3a of the PTC thermistors 2. The respective geometric contact surface F.sub.K,A is smaller than the geometric surface F.sub.S,A of the contact side 6a of the contact socket 5a and is defined respectively by the width B.sub.S,A of the contact side 6a of the contact socket 5a and the length L.sub.PTC of the main side 3a of the respective PTC thermistor 2. The width B.sub.S,A of the contact side 6a of the contact socket 5a is smaller than the width B.sub.PTC of the main side 3a of the respective PTC thermistor 2. As a result the respective PTC thermistor 2 protrudes from the contact socket 5a on both sides in width direction BR, but not in longitudinal direction LR. The contact surface F.sub.K,A is thus smaller than the geometric surface F.sub.PTC of the main side 3a, and a creapage distance 7c between the contact sockets 5a and 5b is larger than the thermistor thickness D.sub.PTC of the PTC thermistor 2.

[0040] The PTC heating module 1 here comprises a number of contact sockets 5b, on which in deviation from the second embodiment of the PTC heating module 1 the geometric surface F.sub.S,B is larger than the contact surface F.sub.K,B. The contact surface F.sub.K,B is defined by the length L.sub.S,B of the contact side 6b of the contact socket 5b and the width B.sub.PTC of the main side 3b of the PTC thermistor 2. The length L.sub.S,B of the contact side 6b of the contact socket 5b is smaller than the length L.sub.PTC of the main side 3b of the respective PTC thermistor 2, so that the respective PTC thermistor 2 protrudes from the contact socket 5b, not in width direction BR, but on both sides in longitudinal direction LR. As a result the contact surface F.sub.K,B is smaller than the geometric surface F.sub.PTC and a creapage distance 7c between the contact sockets 5a and 5b is larger than the thermistor thickness D.sub.PTC of the PTC thermistor 2. The respective contact sockets 5b are formed integrally with the contact plate 4b.

[0041] The creapage distance 7c between the contact sockets 5a and 5b is therefore defined by the contact socket 5a when viewed in width direction BR, und by the contact socket 5b when viewed in longitudinal direction LR, on the respective PTC thermistor 2. In this embodiment the socket 5a and the socket 5b are not identical. In this case, the contact surfaces F.sub.K,A and F.sub.K,B, the lengths L.sub.S,A and L.sub.S,B of the contact sides 6a and 6b, the widths B.sub.S,A and B.sub.S,B of the contact sides 6a and 6b are different. Furthermore, the creapage distance 7c in longitudinal direction LR differs from the creapage distance 7c in width direction BR, but can be identical to it.

[0042] FIG. 17 shows a sectional view of the PTC heating module 1 according to the invention. Here the contact plate 4a forms a first housing part 9a and the contact plate 4b forms a second housing part 9b. The first housing part 9a and the second housing part 9b thus form a housing 9 encasing the respective PTC thermistors 2. The first housing part 9a and the second housing part 9b are electrically insulated by an insulation 10 towards the outside and from each other. The insulation 10 is conveniently heat-conducting so that the heat generated in the respective PTC thermistor 2 can be dissipated to outside. Advantageously the PTC heating module 1 comprises only a few layers so that the heat can be efficiently dissipated towards the outside. Further the insulating layer 10 forms the outermost layer with the largest heat-dissipating surface 11 of the PTC heating module 1. Since the insulating layer 10 usually comprises a lower heat conductivity than the contact plates 4a and 4b, the larger heat-dissipating surface 11 can compensate for the lower heat conductivity of the insulating layer 10. Thus the output of the PTC heating module 1 can be altogether increased. In FIG. 17 the construction of the contact sockets 5a and 5b corresponds to the second embodiment of the PTC heating module 1 in FIGS. 6 to 10. The difference here is that the contact sockets 5a and 5B are designed integrally with the contact plates 4a and 4b.

[0043] In conclusion the distance between the two contact plates 4a and 4b in the PTC heating module 1 according to the invention can be adapted to the specified voltage in a simple way, not by the thermistor thickness D.sub.PTC, but by the adjusted thickness D.sub.S,A and/or D.sub.S,B of the contact socket. The clearance distance 7a defined by the distance of the contact plates 4a and 4b is larger than the thermistor thickness D.sub.PTC of the respective PTC thermistor 2. Further the creapage distances 7b und 7c can be adapted to the specified voltage, not by the thermistor thickness D.sub.PTC, but by the contact surface F.sub.K. The thermistor thickness D.sub.PTC of the respective PTC thermistor 2 is therefore independent of the specified voltage and can in comparison to conventional solutions be adapted to the desired output of the PTC heating module 1.