CN212393013U - Electric heating device - Google Patents

Abstract

The utility model relates to an electric heating device, electric heating device has the casing that has the partition wall, the partition wall will connect the cavity and separate with the heating cavity in order to be used for heat output to protruding as the direction of heating rib towards the heating cavity from at least one PTC heating device, wherein, PTC heating device has at least one PTC component and has the conductor area of being connected with PTC component electricity conduction for the PTC component power supply that has different polarities, the conductor area is connected electrically in connecting the cavity, and the casing constitutes the face of putting to power transistor. The placement surface is formed by a partition wall and is arranged offset in relation to a cooling dome, which corresponds to the placement surface and is arranged in the heating chamber, in the longitudinal direction of the PTC heating device.

Description

Electric heating device

Technical Field

The utility model relates to an electric heating equipment, this electric heating equipment have the casing that has the partition wall, and this partition wall will connect the cavity and separate with the heating cavity in order to be used for heat output. At least one PTC heating device protrudes from the partition wall as a heating rib in a direction toward the heating chamber. The PTC heating device has at least one PTC element and, for energizing PTC elements of different polarity, conductor strips which are electrically conductively connected to the PTC element and are electrically connected in a connection chamber.

Background

An electric heating device with a cooling dome which projects into the heating chamber and has power transistors applied to its contact surfaces on opposite sides is known from EP 3334142 a 1. In this prior art, the power transistor is located in a special receptacle of the control housing, which is separate from the connection chamber.

An electrical heating device is known from EP 1872986 a1, in whose connection chamber a printed circuit board is also provided, which is equipped so that the heating device is particularly compact in construction, and the power transistors are placed on a cooling surface formed by the housing.

DE 19738318 a1 discloses an electric heating device, in which a cooling element is provided for each power transistor, which cooling element projects into a heating chamber, and there is formed a cooling dome exposed in the heating chamber, by means of which cooling dome the power losses generated by the power transistors are used for heating the air to be extracted.

SUMMERY OF THE UTILITY MODEL

The present invention is to provide an electric heating device of compact design, which is capable of delivering the power loss generated by the power transistor well and using this power loss for heating the medium to be heated.

Therefore, the utility model provides an electric heating equipment.

Such an electric heating device is preferably an electric heating device for a motor vehicle. The housing is generally a housing which is suitable for the construction for heating the fluid medium and which for this purpose has inlet and outlet connections and additionally seals the heating chamber. The dividing wall separates the connection chamber from the heating chamber, typically in a fluid-tight manner. The upper end of the PTC heating device extends through the partition wall. A plurality of PTC heating devices are typically provided which project into the heating chamber as heat sinks. The end of the PTC heating device projecting into the connection chamber usually comprises contact tongues which are electrically contacted in the connection chamber, for which purpose a contact device is preferably provided which combines different PTC heating devices by dividing the contact tongues into heating circuits and is provided with contact tongues which are aligned with the contact tongues of the PTC heater and project into the equipped printed circuit board. The printed circuit board, which is equipped to control the supply current for heating the PTC heating device, generally forms the control device.

In the electric heating apparatus according to the present invention, the placement surface is formed by the partition wall. The resting face is therefore generally opposite the heating chamber and is exposed in the connecting chamber. This means that the distance between the medium to be heated and the resting surface is very large. The resting surface is thermally connected to a corresponding cooling dome, which is arranged in the heating chamber.

According to a first aspect of the invention, the cooling domes are staggered with respect to the corresponding resting surfaces. This offset is shown in the longitudinal direction in a plan view of the PTC heating device. This longitudinal direction corresponds to the insertion direction when the PTC heating device is inserted into the partition wall. This longitudinal direction corresponds to the longitudinal extension of the contact tongues on the PTC heating device. The longitudinal direction extends generally at right angles to the main extension direction of the partition wall. The cooling dome is then not arranged in a direct extension as a resting surface. The heating chamber can be provided with a smaller floor than the connecting chamber, which is particularly important in the case of compact electric heating devices for motor vehicles. The center point of the resting surface is offset with respect to the longitudinal center axis or the plane of symmetry of the cooling dome.

According to a second aspect of the invention, the cooling dome has an outer face extending parallel to the adjacent edge face of the heating chamber. The outer face forms a cooling channel together with the edge face of the heating chamber. The cooling channels have a relatively small width. The width of the cooling channel, i.e. the distance between the edge surface and the outer surface of the cooling dome, is selected in such a way that turbulent flow conditions occur between the cooling dome and the edge surface, whereby the heat removal from the cooling dome and thus also the cooling of the power transistor is improved. Preferably, the width of the cooling channel is preferably between 3mm and 8 mm.

The cooling dome is generally located in the extension of the PTC heating device in its width direction. PTC heating devices usually have a longitudinal extension representing the maximum dimension of a square PTC heating device. The width direction is the second largest extension. The third stretch is the thickness direction which connects the main sides for heat dissipation, which are opposite to each other, to each other. The main side is usually defined by the width direction and, quite importantly, the longitudinal extension of the PTC heating device.

The plan view according to the preferred embodiment corresponds to a sectional view of the PTC heating device in the direction of the partition wall. In this top view, the cooling dome has a convexly curved outer face. The opposite edge face of the heating chamber is preferably concavely shaped in accordance with the contour of the cooling dome, so that a cooling channel with a sufficient axial extent is obtained. In plan view, the cooling dome is in the present case preferably designed as an elongated, preferably curved rib. As mentioned above, the ribs extend parallel to the opposite edge faces of the heating chamber at least on the outside, so that the cooling channel is formed with a substantially constant cross section profiled in the flow direction. The elongate ribs preferably extend in a roof shape over both flow channels. These flow channels are flow channels formed by a single PTC heating device on the main sides of the PTC heating devices which are arranged opposite and parallel to one another. This measure also results in an improved heat output at the face of the cooling dome, since the flow transition from one of the flow channels to the other is achieved by the elongate ribs. In a corresponding configuration, the cooling dome is preferably located in the widthwise extension of the PTC heating device.

Drawings

Other advantages and details of the invention are obtained from the following description of embodiments in conjunction with the accompanying drawings. Wherein:

fig. 1 shows a perspective exploded view of an embodiment of an electric heating device;

figure 2 shows a top view of the upper part of the housing provided with the printed circuit board;

FIG. 3 shows a cross-sectional view along the line IV-IV illustrated in FIG. 2;

fig. 4 shows a plan view according to fig. 2 with the printed circuit board removed;

FIG. 5 shows a cross-sectional view according to the line V-V of the illustration in FIG. 4;

FIG. 6 shows a cross-sectional view according to the line VI-VI of the diagram in FIG. 4;

FIG. 7 shows a bottom perspective view of the embodiment;

FIG. 8 shows a bottom view of the embodiment;

fig. 9 shows a sectional view according to the line IX-IX of the illustration in fig. 8;

figure 10 shows a transverse cross-section through the heating chamber towards the dividing wall; and

fig. 11 shows detail D from fig. 10 in an enlarged illustration.

Detailed Description

Fig. 1 shows an exemplary embodiment of an electric heating device 100 with a multi-part housing, which comprises a lower housing part 102 made of a plastic material and an upper housing part 104 made in one piece of metal by means of die casting.

The housing lower part 102 is channel-shaped and encloses a heating chamber 106, the heating chamber 106 being provided with inlet and outlet connections 110 which project from the bottom 106. These inlet and outlet fittings 110 are integrally formed with the lower housing portion 102 by injection molding.

Inlet and outlet fittings 110 project from the base 108. The inlet and outlet fittings extend at right angles from the flat face formed by the base 106.

Between the housing upper part 104 and the housing lower part 102, a plurality of PTC heating devices 112 are shown in the figure, which have PTC elements arranged in the PTC heating devices 112, which are in electrically conductive contact via conductor tracks. The conductor strips are electrically connected by means of contact tongues 114. The PTC heating device 112 is held in an insertion contact manner in a receptacle 116 provided for this purpose of a partition wall 117 of the housing upper part 104. Details of this construction are described in the applicant's relevant EP 3334242 a 1.

Other elements of the heating device 100 are shown between the lower housing portion 102 and the upper housing portion 104. A high-pressure plug element is designated by reference numeral 118, which is screwed to the housing lower part 104 and has contact elements which extend into a connection chamber 120 of the housing upper part 104. Such a contact element is electrically connected to a printed circuit board, designated by reference numeral 122, which can be accommodated in the channel-shaped housing upper part 104. A seal, indicated by reference numeral 124, seals the lower housing part 102 against the upper housing part 104, thereby sealing the heating chamber 106.

The holding member 126 provided with the elastic protrusion has heating device accommodating portions 128 that individually accommodate the respective PTC heating devices 112, respectively, and that engage with the outer peripheral surfaces of the respective PTC heating devices 112. In the assembled state, the holding element 126 is also connected to the housing lower part 104 in a form-fitting and/or force-fitting manner.

Arranged above the housing upper part 104 and below the printed circuit board 122 are contact devices 130, which electrically connect all the contact tongues 114 and group the individual PTC heating devices 112 into a heating circuit. The electrical connection between the contact device 130 and the printed circuit board 122 is established by means of contact tongues 132 protruding from the contact device 130. A control signal plug element is shown at 134 in connection with and protruding from the printed circuit board 142. The control signal plug element 134 is screwed to the printed circuit board 122.

Above the printed circuit board 122, a further circumferential seal 136 and a control housing cover 138 are shown, by means of which the connection chamber 120 of the housing upper part 104 is covered and sealed. The control housing cover 138 is formed from metal in order to shield the housing upper part 104 from electromagnetic radiation which is generated by the switching on of the power current in the control housing 104, 136, 138. A support backbone 140 is arranged between the control housing cover 138 and the printed circuit board 122, and a compression element 142 is supported between itself and the printed circuit board 122, for example, in order to press the power transistors mounted on the printed circuit board 122 against a cooling surface which is in heat-conducting connection with a cooling dome which extends into the heating chamber 106. The cooling surface is in heat-conducting connection with the power transistor.

After assembly, the connecting rod 144 engages behind locking projections 146 which are provided on the housing lower part 102 and the housing upper part 104 in order to connect the two parts 102, 104 to one another in a form-fitting manner without or with little loss. Details of this are described in EP 2796804 a 1.

The control housing cover 138, together with the housing upper portion 104 and the seal 136, form a control housing 146. Here, the control housing cover 138 and the housing upper part 104 form a shield, due to their metallic material, around a control device 148 accommodated in a control housing 146, which is essentially formed by the printed circuit board 122. The connecting bolt 150 projects from the control housing 146 in the direction of the plug elements 118, 134 (from the connector 110). The connecting bolt 150 is used to ground the metal control housing 146 and is screwed to the control housing 146.

Fig. 3 shows a populated printed circuit board 300 equipped with components generally indicated at 306 on one side, which also includes a power transistor 308. As shown on the left in fig. 2, the power-current contact element 442 of the power-current plug, which is designated by the reference numeral 440 in fig. 7 to 10, is contacted directly in the printed circuit board 300, which has the contact tongue receptacle 304 for this purpose. An insulating tab, designated by reference numeral 446, is received in a T-shaped receptacle in the printed circuit board 300 in order to increase the air gap and the creepage distance between the individual power current contact elements 442.

The power transistor 308 rests on a cooling surface 510, which is formed by the housing upper part 500, in particular the partition 117, and is inserted into the printed circuit board 300, against the cooling surface 510. The printed circuit board 300 is modified in the region of the power transistor 308 in such a way that it is particularly thermally conductive. In fig. 3 it has been shown that: the cooling domes 512 corresponding to the respective cooling surfaces 510 are each shifted to the right in fig. 3. The cooling dome 512 is also displaced slightly inward and toward the direction of the heating chamber 106. As shown in particular in fig. 10, the cooling dome 512 is shaped as an elongated rib and has a convexly curved outer face 514 which is arranged slightly towards the edge face 580 of the housing lower part 102, so that a cooling channel 582 is formed between the edge face 580 of the cooling dome 512 and the outer face 514. Due to the elongated shape of the cooling dome 512, the cooling channel 512 has a substantially constant width in the top view of the cooling dome 512 shown in fig. 10 and 11. The inner face of the cooling dome 512, indicated by reference numeral 516, is concavely shaped. Because the cooling dome 512 is shaped as an elongated cooling rib.

In fig. 9-11, the PTC heating apparatus, which is designated by reference numeral 112 in fig. 1, is designated by reference numeral 600. The PTC heating devices 600 each have opposite main sides 602, which each define a flow channel 604 in which the liquid medium to be heated is conducted. The PTC heaters 600 are respectively applied to the edge faces 580 of the housing lower part 102 which are opposite to each other. The housing lower part 102 forms a receptacle 584, which is C-shaped in cross section according to fig. 5 and which receives the end face 606 of the PTC heating device 600 in itself. Here, the end surface 606 connects the main sides, which are designated by reference numeral 602, for heat dissipation. The end surface 606 of the PTC heating element 600 abuts against the edge surface 580. In fig. 10, each first PTC heating element 600 abuts against the upper edge face 580, and each second PTC heating element 600 abuts against the lower edge face of the housing lower part 102.

The cooling dome 512 is present opposite the opposite end surface 606. The inner face 516 surroundingly covers the respective end face 606. The inner face serves to divert the flow of the fluid stream guided in the flow channel 604.

The design of the PTC heating device 600 shown in fig. 10 and its arrangement relative to the edge face 580 of the housing lower part 102 result in a meandering flow channel 604 which leads the fluid from the widened inlet 608 (upper left) to the widened outlet 610 (lower right) in fig. 10. In this case, the medium to be heated flows through all the main sides 602. The deflection of the (abfinden) flow is compensated for, respectively, at the height of the cooling dome 512. This allows a small portion to flow through the cooling channel 582. Accordingly, the cooling channel 582 is well surrounded by the medium to be heated and thus cooled. The flow volume and width of the cooling channel 582 is set such that: resulting in turbulent conditions at the cooling channel 582 which results in improved heat transfer from the cooling dome 512 to the fluid to be heated.

In fig. 10, the tip of a temperature sensor, designated by reference numeral 400, can be seen in the region of the outlet 610, which temperature sensor measures the outlet temperature of the fluid to be heated and controls the heating power accordingly.

In fig. 10, the lower housing portion 102 can be seen in more detail. The C-shaped receptacle 584 is shaped such that a slit 586, which extends in the longitudinal direction L of the PTC heating device 600, is formed between the end face 606 and the face of the C-shaped receptacle 584 opposite thereto. Since the PTC heating device 600 may be subject to fluctuations in size and shape on its end faces due to manufacture, on the other hand, the PTC heating device should be accommodated as fluid-tightly as possible in the receptacle 584, the slits serving to compensate for tolerances. The slits 586 also allow the C-shaped receiver 584 to be spread apart to such an extent that the two legs of the C-shaped receiver 584 can be brought from the outside against the PTC heating apparatus 600.

In the embodiment shown, the lower housing part 102 is made of a synthetic material.

As can also be seen in fig. 10, the heating chamber 106 has a substantially rectangular cross section in the top view shown. For this, the PTC heating device 600 is obliquely oriented such that the width of the heating chamber 106 (in the vertical direction of fig. 5) is smaller than the width of the PTC heating device 600. The PTC heating device is inclined at about 30 to 50 °. Thereby, a more compact construction of the electric heating device is obtained. However, the PTC heating devices 600 are oriented to extend parallel to each other in order to form parallel-extending flow channels 604 having the same width. The inlet and outlet ports 608, 610 are located in the corners of the substantially rectangular bottom surface.

As can be seen from fig. 9, the PTC heating device 600 is inserted with its other end into the receiving portion on the bottom of the housing lower part 102 and with its upper end into the receiving portion 116 of the partition wall 117. Thus, the flow channel 604 is delimited at the upper and lower sides by the PTC heating device.

Fig. 10 also shows a fluid-technical advantageous design of the heating chamber 106. This avoids a rectangular flow cross section. Opposite the cooling dome 512, the edge surface of the housing lower part 102 is concavely shaped in order to transfer the fluid from one flow channel 604 to the next flow channel with low loss at the free end surface 606 of the PTC heating device 600. All deflection points in the upper part of the heating chamber 106 are formed by one cooling dome 512 each.

This embodiment then has a compact construction and enables good cooling of the power transistor by improving the heat output to the medium heated in the heating chamber 106.

List of reference numerals

100 electric heating device

102 lower part of the housing

104 upper part of the housing

106 heating chamber

108 bottom

110 inlet and outlet fittings

112 PTC heating device

114 contact tongue

116 accommodating part

117 separating wall

118 high-voltage plug element

120 connecting chamber

122 printed circuit board

124 seal

126 holding element

128 heating device receptacle

130 contact device

132 contact pin

134 control signal plug-in element

136 seal

138 control housing cover

140 supporting framework

142 compression element

144 connecting rod

146 control housing

148 control device

150 connecting bolt

300 printed circuit board

304 contact tongue receiving portion

306 member

308 power transistor

400 temperature sensor

442 power current contact element

440 power current plug

446 insulating tab

480 control current plug

500 upper part of the shell

510 cooling surface

512 cooled dome

516 cool the inner face of the dome

580 edge surface

582 cooling channel

584C-shaped receiving part

586 slit extending in the longitudinal direction L

600 PTC heating device

602 major side surface

604 flow channel

606 PTC heating device end face

608 widened inlet

610 widened outlet

L longitudinal direction.

Claims (14)

1. An electric heating device (100) having a housing (102; 104) with a partition (117) which separates a connecting chamber (120) from a heating chamber (106) for heat output and protrudes from at least one PTC heating device (112; 600) as a heating rib in the direction of the heating chamber (106), wherein the PTC heating device (112; 600) has at least one PTC element and, for supplying power to PTC elements having different polarities, conductor strips which are electrically connected to the PTC element and are electrically connected in the connecting chamber (120), the housing (102; 104) forming a resting face for a power transistor (308), characterized in that the resting face (510) is formed by the partition (117) and is arranged offset in relation to a cooling dome (512) in the longitudinal direction (L) of the PTC heating device (112; 600), the cooling dome corresponds to the resting surface (510) and is arranged in the heating chamber.

2. Electrical heating device (100) according to claim 1, characterised in that, in the longitudinal direction of the PTC heating device (112; 600), the resting face (510) is arranged offset with respect to the corresponding cooling dome (512) in the lateral direction or at right angles to the lateral direction and inwards in the direction of the heating chamber (106) and thus in the transverse direction of the heating chamber (106) with an elongated bottom face.

3. Electric heating device (100) according to claim 2, characterized in that in a top view of the cooling dome (512), in the longitudinal extension direction of the PTC heating arrangement (112; 600), the outer face of the cooling dome (512) is convexly curved.

4. Electrical heating device (100) according to claim 3, characterized in that, in a top view of the cooling dome (512), in the direction of longitudinal extension of the PTC heating means (112; 600), the cooling dome (512) is designed as an elongated rib.

5. An electric heating device (100) according to claim 4, characterized in that the elongated ribs are configured in a manner parallel to the opposite edge faces (580) of the heating chamber (106).

6. Electrical heating device (100) according to claim 5, characterised in that the outer faces of the elongated ribs and the opposite edge faces (580) of the heating chamber (106) constitute, in top view, cooling channels (582) of constant width.

7. Electrical heating device (100) according to claim 6, characterised in that the inner face (516) of the elongate rib is concavely configured and covers two flow channels (604) extending parallel to a main side of one of the PTC heating means (112) in a roof-like manner.

8. An electric heating device (100) having a housing (102; 104) with a partition wall (117) which separates a connection chamber (120) from a heating chamber (106) for heat output and protrudes from at least one PTC heating device (112; 600) as a heating rib in the direction of the heating chamber (106), wherein the PTC heating device (112; 600) has at least one PTC element and, for supplying power to PTC elements having different polarities, conductor strips which are electrically connected to the PTC element and are electrically connected in the connection chamber (120), the housing (102; 104) forming a resting face for a power transistor (308), characterized in that a cooling dome (512) corresponding to the resting face (510) for the power transistor (308) has an outer face which extends parallel to an adjacent edge face (580) of the heating chamber (106), such that a cooling channel (582) is formed between the edge face (580) and the exterior face.

9. Electrical heating device (100) according to claim 8, characterised in that, in the longitudinal direction of the PTC heating device (112; 600), the resting face (510) is arranged offset with respect to the corresponding cooling dome (512) in the lateral direction or at right angles to the lateral direction and inwards in the direction of the heating chamber (106) and thus in the transverse direction of the heating chamber (106) with an elongated bottom face.

10. Electric heating device (100) according to claim 9, characterized in that in a top view of the cooling dome (512), in the longitudinal extension direction of the PTC heating arrangement (112; 600), the outer face of the cooling dome (512) is convexly curved.

11. Electric heating device (100) according to claim 10, characterized in that the cooling dome (512) is designed as an elongated rib in a top view of the cooling dome (512) in the longitudinal extension direction of the PTC heating arrangement (112; 600).

12. An electric heating device (100) according to claim 11, characterized in that the elongated ribs are configured in a manner parallel to the opposite edge faces (580) of the heating chamber (106).

13. Electrical heating device (100) according to claim 12, wherein the outer faces of the elongated ribs and the opposite edge faces (580) of the heating chamber (106) constitute, in top view, cooling channels (582) having a constant width.

14. Electrical heating device (100) according to claim 13, characterized in that the inner face (516) of the elongated rib is concavely configured and covers two flow channels (604) extending parallel to a main side of one of the PTC heating devices (112) in a roof-like manner.

Images