Heat exchanger

Abstract

To provide a heat exchanger capable of suppressing stress concentration to a stationary part of a ceramic heater.SOLUTION: A heat exchanger 10 comprises: a porcelain tube 20 which extends in an axial direction and is cylindrically formed; a first flange 30 which is disposed on one side of the porcelain tube 20 in the axial direction and expanded in diameter from an outer periphery of the porcelain tube 20 to the outside in a radial direction; a ceramic heater 11 including a terminal part 25 which is disposed on one side of the porcelain tube 20 in the axial direction rather than the first flange 30, and a heating section 28 which is disposed on the other side of the porcelain tube 20 in the axial direction rather than the first flange 30; and a housing 60 in which the porcelain tube 20 is stored and to which the ceramic heater 11 is fixed via the first flange 30 in a water-tight manner. The heat exchange 10 is mounted on a vehicle. The ceramic heater 11 comprises a second flange 40 which is disposed separately from the first flange 30 in the axial direction and expanded in diameter from the outer periphery of the porcelain tube 20 to the outside in the radial direction, and is fixed to the housing 60 via the second flange 40.SELECTED DRAWING: Figure 1

Description

Technical Field

[0001] The present disclosure relates to a heat exchanger.

Background Art

[0002] Conventionally, an electric heating type hot water heating device described in Japanese Patent Application Laid-Open No. 2013-126844 (Patent Document 1 below) has been known. The electric heating type hot water heating device of Patent Document 1 includes a case having an inlet, a flow path, and an outlet for a heat medium, and a ceramic heater disposed in the flow path. A flange is attached to the outer periphery of the terminal portion side of the ceramic heater. The ceramic heater is fixed in the case by attaching this flange to the inner peripheral surface of an insertion port provided in the case via a sealing member such as an O-ring.

Prior Art Documents

Patent Documents

[0003]

Patent Document 1

Summary of the Invention

Problems to be Solved by the Invention

[0004] In the above configuration, the ceramic heater is fixed via one flange to the case. For this reason, for example, when the electric heating type hot water heating device is for in-vehicle use, stress may concentrate on the fixing portion between the flange and the case or the fixing portion between the ceramic heater and the flange due to vibrations of the vehicle or the like.

[0005] The present disclosure has been completed based on the above circumstances, and an object thereof is to provide a heat exchanger capable of suppressing stress concentration on the fixing portion of the ceramic heater.

Means for Solving the Problems

[0006] The heat exchanger of the present disclosure includes a ceramic heater having a heat pipe that extends in the axial direction and has a cylindrical shape, a first flange disposed on one side in the axial direction of the heat pipe and having a diameter that expands radially outward from the outer periphery of the heat pipe, a terminal portion disposed on one side in the axial direction of the heat pipe relative to the first flange, and a heating portion disposed on the other side in the axial direction of the heat pipe relative to the first flange, and a housing that houses the heat pipe and to which the ceramic heater is watertightly fixed via the first flange. The ceramic heater includes a second flange that is spaced apart from the first flange in the axial direction and has a diameter that expands radially outward from the outer periphery of the heat pipe, and is fixed to the housing via the second flange.

Advantages of the Invention

[0007] According to the present disclosure, it is possible to provide a heat exchanger that can suppress stress concentration on the fixing portion of the ceramic heater.

Brief Description of the Drawings

[0008]

Figure 1

Figure 2

Figure 3

Figure 4

Figure 5

Figure 6

Embodiments for Carrying Out the Invention

[0009] [Description of Embodiments of the Present Disclosure] First, embodiments of the present disclosure will be listed and described. (1) The heat exchanger of the present disclosure includes a ceramic heater having a tube extending in the axial direction and having a cylindrical shape, a first flange disposed on one side in the axial direction of the tube and expanding radially outward from the outer periphery of the tube, a terminal portion disposed on one side in the axial direction of the tube relative to the first flange, and a heating portion disposed on the other side in the axial direction of the tube relative to the first flange, and a housing in which the tube is accommodated and the ceramic heater is watertightly fixed via the first flange, wherein the ceramic heater is disposed at a distance from the first flange in the axial direction and includes a second flange expanding radially outward from the outer periphery of the tube, and is fixed to the housing via the second flange.

[0010] According to such a configuration, since the ceramic heater is fixed to the housing by the first flange and the second flange, the stress applied to the fixing portion between the ceramic heater and the housing in a vibration environment can be dispersed at two locations. Further, compared with the case where only one fixing portion between the flange and the tube is provided, the stress can be dispersed to the fixing portion between the first flange and the tube and the fixing portion between the second flange and the tube, respectively.

[0011] (2) In the heat exchanger according to (1), it is preferable that the first flange and the second flange are fixed to the inner peripheral surface of the housing via a seal member disposed on their outer peripheries.

[0012] According to such a configuration, the first flange and the second flange can be watertightly fixed to the housing.

[0013] (3) In the heat exchanger according to (1), it is preferable that the second flange is disposed on one side in the axial direction relative to the terminal portion.

[0014] With such a configuration, the space between the first flange and the second flange arranged axially apart can be effectively utilized, and the heat exchanger can be miniaturized.

[0015] (4) In the heat exchanger according to (3), it is preferable that the second flange is watertightly fixed to the housing.

[0016] By watertightly fixing the first flange and the second flange to the housing, water leakage to the terminal portion arranged between the first flange and the second flange can be prevented.

[0017] (5) In the heat exchanger according to (1), it is preferable that the second flange is arranged on the other side in the axial direction than the terminal portion.

[0018] With such a configuration, by fixing one side in the axial direction than the terminal portion with the first flange and fixing the other side in the axial direction than the terminal portion with the second flange, it becomes easier to suppress the vibration on the other side of the ceramic heater, and it is possible to suppress the concentration of stress on the fixing portion between the ceramic heater and the first flange.

[0019] (6) In the heat exchanger according to any one of (1) to (3), the housing includes a first housing in which the heat pipe is accommodated, a third housing assembled to the first housing and watertightly fixed to the first flange, and a second housing formed separately from the third housing and fixed to the second flange, and it is preferable that the first flange has a sandwiching portion sandwiched between the first housing and the third housing in the axial direction.

[0020] With such a configuration, the heat exchanger can be easily assembled. Also, the ceramic heater can be positioned in the axial direction.

[0021] (7) In the heat exchanger according to any one of (1) to (3), the housing includes a first housing that houses the heat pipe, and a second housing that is fixed to the second flange, and the first flange preferably has a clamping portion that is clamped between the first housing and the second housing in the axial direction.

[0022] According to such a configuration, the first flange can be fixed to the housing by clamping the clamping portion between the first housing and the second housing.

[0023] [Details of the Embodiments of the Present Disclosure] <Embodiment 1> Embodiment 1 of the present disclosure will be described with reference to FIGS. 1 to 4. It should be noted that the present disclosure is not limited to these examples, but is defined by the claims, and is intended to include all modifications within the meaning and scope equivalent to the claims. In the following description, for a plurality of identical members, only some members may be labeled, and the labels of other members may be omitted.

[0024] <Heat Exchanger> The heat exchanger 10 according to the present embodiment is a device that heats a liquid such as water. The heat exchanger 10 is mounted on a vehicle such as an electric vehicle (EV), for example, and is used for heating the passenger compartment and keeping the battery warm. As shown in FIGS. 1 and 2, the heat exchanger 10 includes a ceramic heater 11 and a housing 60 that houses the ceramic heater 11.

[0025] <Ceramic Heater> The ceramic heater 11 includes a heat pipe 20, a first flange 30, a second flange 40, and a terminal portion 25. The heat pipe 20 has a cylindrical shape centered on the axis AX. The heat pipe 20 extends in the axial direction (the direction in which the axis AX extends). The heat pipe 20 includes a ceramic pipe 21 having a cylindrical shape and a ceramic layer 22 that covers substantially the entire outer periphery of the ceramic pipe 21. The ceramic pipe 21 and the ceramic layer 22 are made of a ceramic material such as alumina, for example.

[0026] As shown in FIG. 3, a heater pattern layer 23 and a pair of internal terminals 24 are formed on the inner peripheral surface (the surface on the side of the ceramic tube 21) or inside the ceramic layer 22. The heater pattern layer 23 has a meandering thin wire shape. The internal terminal 24 has a wide rectangular shape compared to the heater pattern layer 23. These internal terminals 24 are electrically connected to the terminal portion 25 via a via conductor or the like (not shown). The terminal portion 25 is formed on the outer peripheral surface of the ceramic layer 22.

[0027] The ceramic tube 20 can be manufactured, for example, by firing a ceramic tube 21 that has been pre-fired and wrapped with a ceramic sheet 26. A conductor layer 27 such as tungsten is formed on the surface or inside of the ceramic sheet 26. After firing, the conductor layer 27 becomes the heater pattern layer 23, the internal terminal 24, and the terminal portion 25.

[0028] The first flange 30 is, for example, an annular member made of a metal such as stainless steel. The first flange 30 generally has a cup shape, for example. The first flange 30 includes a bottom portion 31, a peripheral wall portion 32, and a clamping portion 33. As shown in FIG. 4, a through hole 31A that penetrates the bottom portion 31 in the axial direction is formed in the first flange 30. The peripheral wall portion 32 has a substantially cylindrical shape and extends in the axial direction from the outer peripheral edge portion of the bottom portion 31. The clamping portion 33 has a plate shape and extends radially outward from the end portion of the peripheral wall portion 32 on the side opposite to the bottom portion 31. Here, the radial direction is a direction orthogonal to the axial direction and refers to the direction in which a virtual axis intersecting the axis AX extends. The radially outer side refers to the direction away from the axis AX along the virtual axis. The radially inner side refers to the direction approaching the axis AX along the virtual axis.

[0029] The first flange 30 is fixed to the obstruction tube 20 with the obstruction tube 20 inserted through the through-hole 31A. Specifically, the first flange 30 is fixed to the obstruction tube 20 by filling the space formed by the bottom 31, the peripheral wall portion 32, and the outer peripheral surface of the obstruction tube 20 with glass 34. The first flange 30 is disposed on one side (the left side in FIGS. 1 and 2) in the axial direction of the obstruction tube 20 and has a diameter that expands radially outward from the outer periphery of the obstruction tube 20. As shown in FIG. 1, the terminal portion 25 is disposed on one side in the axial direction with respect to the first flange 30.

[0030] The second flange 40 is, for example, an annular member made of a metal such as stainless steel. The second flange 40 generally has a cylindrical shape, for example. The second flange 40 includes a large-diameter portion 41, a small-diameter portion 42 having a smaller diameter than the large-diameter portion 41, and a connecting portion 43 that forms a step and axially connects the large-diameter portion 41 and the small-diameter portion 42.

[0031] As shown in FIG. 4, the second flange 40 is fixed to the obstruction tube 20 with one end of the obstruction tube 20 in the axial direction inserted inside the second flange 40. Specifically, the second flange 40 is fixed to the obstruction tube 20 by filling the space surrounded by the outer peripheral surface of the obstruction tube 20, the inner peripheral surface of the second flange 40 from the large-diameter portion 41 to the connecting portion 43, and a spacer 50 described later with glass 44.

[0032] The outer diameter of the obstruction tube 20 is smaller than the inner diameter of the small-diameter portion 42, and a gap is formed between the outer peripheral surface of the obstruction tube 20 and the inner peripheral surfaces of the small-diameter portion 42 and the connecting portion 43. By disposing the spacer 50 in this gap, a space is formed for accumulating the glass 44 for fixing the second flange 40 to the obstruction tube 20. The spacer 50 includes a cylindrical portion 51 that has a cylindrical shape and extends in the left-right direction, and a flange portion 52 that projects radially outward from the edge of the cylindrical portion 51. The inner peripheral surface of the cylindrical portion 51 is disposed along the outer peripheral surface of the obstruction tube 20. The flange portion 52 is disposed in contact with the inner peripheral surface of the connecting portion 43.

[0033] The second flange 40 is arranged at an axial distance from the first flange 30 and has a diameter that expands radially outward from the outer periphery of the obstruction tube 20. The second flange 40 is arranged on one side in the axial direction relative to the first flange 30. Also, as shown in FIG. 1, the second flange 40 is arranged on one side in the axial direction relative to the terminal portion 25.

[0034] At the connection portions of each of the flanges 30, 40 and the obstruction tube 20 in the ceramic heater 11 (i.e., the portions sealed with the glass 34, 44), liquid leakage is prevented. As the glass 34, 44, for example, glass of the Na2O·Al2O3·B2O3·SiO2 system, so-called glass of the Al2O3·B2O3·SiO2 system (borosilicate glass) is used.

[0035] <Housing> As shown in FIGS. 1 and 2, the housing 60 houses the ceramic heater 11. The housing 60 forms part of a flow path FC through which liquid flows. The housing 60 fixes the ceramic heater 11 in a watertight manner via the first flange 30. Also, the housing 60 fixes the ceramic heater 11 via the second flange 40. Specifically, the housing 60 may fix the ceramic heater 11 in a watertight manner via the second flange 40. Here, watertight fixing means that a plurality of members are fixed by a fixing portion, and liquid leakage through this fixing portion is prevented.

[0036] The housing 60 includes a third housing 70, a second housing 80, and a first housing 90 that are formed separately. The third housing 70 is assembled to the second housing 80. The first housing 90 is assembled to the third housing 70. The third housing 70 is watertightly fitted to the first flange 30. The second housing 80 is watertightly fitted to the second flange 40. Here, watertight fitting means that a plurality of members are fitted at a fitting portion, and liquid leakage through this fitting portion is prevented.

[0037] <First housing> The first housing 90 houses a portion of the obstruction tube 20 that is opposite to the portion where the first flange 30, the terminal portion 25, and the second flange 40 are arranged in the axial direction. As shown in FIG. 3, the portion of the obstruction tube 20 arranged within the first housing 90 is a portion that includes most of the heater pattern layer 23 and is a portion (hereinafter referred to as the heating portion 28) that is mainly heated by energizing the ceramic heater 11. As shown in FIGS. 1 and 2, the heating portion 28 is arranged on the other side (the right side in the illustrations of FIGS. 1 and 2) in the axial direction of the obstruction tube 20 relative to the first flange 30.

[0038] As shown in FIGS. 1 and 2, the first housing 90 includes an obstruction tube housing portion 91 that houses the heating portion 28 of the obstruction tube 20, a discharge tube 92 formed in communication with the obstruction tube housing portion 91, a base wall 93 that extends radially outward from one end of the obstruction tube housing portion 91 in the axial direction, and an enclosure wall 94 that extends in one direction in the axial direction from the base wall 93. The obstruction tube housing portion 91 has a bottomed cylindrical shape. The inner diameter of the obstruction tube housing portion 91 is formed to be larger than the outer diameter of the obstruction tube 20. The discharge tube 92 extends radially outward, for example, from one end of the obstruction tube housing portion 91 in the axial direction.

[0039] A part of the third housing 70 described later is housed in the space formed by the base wall 93 and the enclosure wall 94. A female screw portion 94A is formed on the inner peripheral surface of the enclosure wall 94. The female screw portion 94A is adapted to be screwed with a male screw portion 72A formed on the outer peripheral surface of the third housing 70. A seal groove 94B for arranging a seal member S3 is formed between the female screw portion 94A and the base wall 93 on the inner peripheral surface of the enclosure wall 94. This seal member S3 is annular and liquid-tightly seals between the outer peripheral surface of the third housing 70 and the inner peripheral surface of the enclosure wall 94.

[0040] The first housing 90 is formed with a first abutting portion 95 that abuts against the clamping portion 33 of the first flange 30 from the other side (the right side in the illustrations of FIGS. 1 and 2) in the axial direction. The first abutting portion 95 may protrude, for example, in one direction in the axial direction from the base wall 93.

[0041] <The third housing> The third housing 70 includes a base wall 71 extending in the radial direction and an enclosing wall 72 extending from the base wall 71 to one side in the axial direction. A first accommodating portion 73 is formed in the third housing 70 so as to penetrate the base wall 71. The first accommodating portion 73 includes a first cylindrical portion 73A through which the obstruction pipe 20 is inserted, a second cylindrical portion 73B in which the peripheral wall portion 32 of the first flange 30 is accommodated, and a third cylindrical portion 73C in which the clamping portion 33 is accommodated. The inner diameter of the third cylindrical portion 73C is larger than the inner diameter of the second cylindrical portion 73B. The inner diameter of the second cylindrical portion 73B is larger than the inner diameter of the first cylindrical portion 73A.

[0042] The inner peripheral surface of the second cylindrical portion 73B watertightly fixes the peripheral wall portion 32 of the first flange 30 via the seal member S1. In other words, an annular seal member S1 is attached to the outer peripheral surface of the peripheral wall portion 32, and the first flange 30 is fixed to the inner peripheral surface of the second cylindrical portion 73B via this seal member S1. Alternatively, the seal member S1 may be mounted in a seal groove (not shown) provided on the inner peripheral surface of the second cylindrical portion 73B. The seal member S1 is compressed in the radial direction by the outer peripheral surface of the peripheral wall portion 32 and the inner peripheral surface of the second cylindrical portion 73B. That is, the first flange 30 is fixed in the radial direction by the second cylindrical portion 73B of the third housing 70. The seal member S1 can prevent liquid from leaking from the first housing 90 side of the first accommodating portion 73 to one side in the axial direction. Therefore, it is possible to prevent the liquid flowing through the flow path FC from leaking to the terminal portion 25 side.

[0043] The third housing 70 is formed with a second abutting portion 74 that abuts on the clamping portion 33 of the first flange 30 from one side in the axial direction. The second abutting portion 74 is arranged at a stepped portion connecting the third cylindrical portion 73C and the second cylindrical portion 73B. The clamping portion 33 is clamped in the axial direction by the first abutting portion 95 and the second abutting portion 74. That is, the first flange 30 is fixed in the axial direction by the third housing 70 and the first housing 90.

[0044] In the space formed by the surrounding wall 72 and the base wall 71, there are arranged a terminal portion 25, a wiring member (not shown) connected to the terminal portion 25, and a part of a second housing 80 described later. A male screw portion 72A is formed on the outer peripheral surface of the surrounding wall 72. The male screw portion 72A is arranged at a position near the other end portion of the surrounding wall 72 in the axial direction. The male screw portion 72A is adapted to be screwed with a female screw portion 94A of the first housing 90. A female screw portion 72B is formed on the inner peripheral surface of the surrounding wall 72. The female screw portion 72B is adapted to be screwed with a male screw portion 82A formed on the outer peripheral surface of the second housing 80. The female screw portion 72B is arranged at a position near one end portion of the surrounding wall 72 in the axial direction. Further, a through hole (not shown) for leading out the wiring member to the outside may be formed in the surrounding wall 72.

[0045] <Second housing> The second housing 80 includes a base wall 81 extending in the radial direction and a surrounding wall 82 extending from the base wall 81 to one side in the axial direction. A second accommodating portion 83 is formed in the second housing 80 so as to penetrate the base wall 81. The second accommodating portion 83 includes a first cylindrical portion 83A through which the small-diameter portion 42 of the second flange 40 can be inserted, and a second cylindrical portion 83B in which the large-diameter portion 41 of the second flange 40 is accommodated. The inner diameter of the second cylindrical portion 83B is larger than the inner diameter of the first cylindrical portion 83A. A part of the connecting portion 43 of the second flange 40 may be accommodated in the first cylindrical portion 83A, and the other part of the connecting portion 43 may be accommodated in the second cylindrical portion 83B. Further, the entire connecting portion 43 may be accommodated in the second cylindrical portion 83B.

[0046] The inner peripheral surface of the second cylindrical portion 83B watertightly fixes the large-diameter portion 41 of the second flange 40 via the seal member S2. In other words, an annular seal member S2 is attached to the outer peripheral surface of the large-diameter portion 41, and the second flange 40 is fixed to the inner peripheral surface of the second cylindrical portion 83B via this seal member S2. Alternatively, the seal member S2 may be mounted in a seal groove (not shown) provided on the inner peripheral surface of the second cylindrical portion 83B. The seal member S2 is radially compressed by the outer peripheral surface of the large-diameter portion 41 and the inner peripheral surface of the second cylindrical portion 83B. That is, the second flange 40 is radially fixed by the second cylindrical portion 83B of the second housing 80. The seal member S2 can prevent liquid from leaking from one side to the other side in the axial direction of the second housing portion 83. Therefore, it is possible to prevent the liquid passing through the flow path FC from leaking to the terminal portion 25 side.

[0047] The small-diameter portion 42 of the second flange 40 is arranged in the space formed by the surrounding wall 82 and the base wall 81. A male screw portion 82A is formed on the outer peripheral surface of the surrounding wall 82. The male screw portion 82A is arranged at a position near the other end in the axial direction of the surrounding wall 82. The male screw portion 82A is adapted to be screwed with the female screw portion 72B of the third housing 70.

[0048] As shown in FIG. 2, the heat exchanger 10 has a flow path FC through which a liquid to be heated flows. The flow path FC includes a first flow path FC1 formed inside the ceramic heater 11 and a second flow path FC2 mainly constituted by the first housing 90. The first flow path FC1 includes the internal space of the small-diameter portion 42 and the internal space of the heat pipe 20. The second flow path FC2 is hermetically sealed by the seal members S1 and S3. As shown by the arrow, the liquid is introduced from the small-diameter portion 42, passes through the heating portion 28 of the heat pipe 20, and enters the second flow path FC2. Thereafter, while the liquid is in thermal contact with the outer peripheral surface of the heating portion 28, it advances to one side in the axial direction and is discharged from the discharge pipe 92. The liquid is heated in the first flow path FC1 and the second flow path FC2. The flow path FC may have a connection flow path (not shown) that liquid-tightly connects, for example, between the discharge pipe 92 and the small-diameter portion 42, or the liquid may be configured to circulate in the flow path FC.

[0049] <Effect of Embodiment 1> As described above, the heat exchanger 10 of Embodiment 1 includes a ceramic heater 11 having a fin tube 20 that extends in the axial direction and has a cylindrical shape, a first flange 30 that is disposed on one side in the axial direction of the fin tube 20 and has a diameter that expands radially outward from the outer periphery of the fin tube 20, a terminal portion 25 that is disposed on one side in the axial direction of the fin tube 20 with respect to the first flange 30, and a heating portion 28 that is disposed on the other side in the axial direction of the fin tube 20 with respect to the first flange 30. The heat exchanger 10 is mounted on a vehicle and includes a housing 60 in which the fin tube 20 is accommodated and the ceramic heater 11 is watertightly fixed via the first flange 30. The ceramic heater 11 is disposed at a distance from the first flange 30 in the axial direction and includes a second flange 40 that expands radially outward from the outer periphery of the fin tube 20, and is fixed to the housing 60 via the second flange 40.

[0050] According to such a configuration, since the ceramic heater 11 is fixed to the housing 60 by the first flange 30 and the second flange 40, the stress applied to the fixing portion between the ceramic heater 11 and the housing 60 in a vibration environment can be dispersed at two locations. Further, compared with the case where only one fixing portion between the flange and the fin tube is provided, the stress can be dispersed at the fixing portion between the first flange 30 and the fin tube 20 and the fixing portion between the second flange 40 and the fin tube 20, respectively.

[0051] In Embodiment 1, the first flange 30 and the second flange 40 are fixed to the inner peripheral surface of the housing 60 via seal members S1 and S2 disposed on their outer peripheries.

[0052] According to such a configuration, the first flange 30 and the second flange 40 can be watertightly fixed to the housing 60.

[0053] In Embodiment 1, the second flange 40 is disposed on one side in the axial direction with respect to the terminal portion 25 and is watertightly fixed to the housing 60.

[0054] With such a configuration, the space between the first flange 30 and the second flange 40 arranged at an axial distance can be effectively utilized, and the heat exchanger 10 can be miniaturized. Further, since the first flange 30 and the second flange 40 are watertightly fixed to the housing 60, water leakage to the terminal portion 25 arranged between the first flange 30 and the second flange 40 can be prevented.

[0055] In Embodiment 1, the housing 60 includes a third housing 70 that is watertightly fitted to the first flange 30, and a second housing 80 that is formed separately from the third housing 70 and is watertightly fitted to the second flange 40.

[0056] With such a configuration, the heat exchanger 10 becomes easy to assemble.

[0057] In Embodiment 1, the housing 60 further includes a first housing 90 that is assembled to the third housing 70, and the first flange 30 has a clamping portion 33 that is clamped between the third housing 70 and the first housing 90 in the axial direction.

[0058] With such a configuration, the ceramic heater 11 can be positioned in the axial direction.

[0059] <Embodiment 2> Embodiment 2 of the present disclosure will be described with reference to FIG. 5. In the following description, for the configurations corresponding to those in Embodiment 1, the reference numerals in Embodiment 1 with 200 added to the numerical part will be used, and the description of the same configurations as those in Embodiment 1 may be omitted.

[0060] The heat exchanger 210 according to Embodiment 2 includes a ceramic heater 211 and a housing 260 that houses the ceramic heater 211. In Embodiment 1, the second flange 40 was arranged on one side in the axial direction of the obstruction pipe 20 (the left side in FIGS. 1 and 2), but in Embodiment 2, the second flange 240 is arranged on the other side in the axial direction of the obstruction pipe 220 (the right side in FIG. 5).

[0061] The ceramic heater 211 includes a heat pipe 220, a first flange 230, a second flange 240, and a terminal portion 225.

[0062] The first flange 230 includes a bottom portion 231 having a through hole, a first peripheral wall portion 232, a clamping portion 233, and a second peripheral wall portion 235. The first peripheral wall portion 232 extends from the outer peripheral edge portion of the bottom portion 231 to the other side in the axial direction. The second peripheral wall portion 235 extends from the inner peripheral edge portion of the bottom portion 231 to one side in the axial direction. The clamping portion 233 extends radially outward from the end portion of the first peripheral wall portion 232 on the side opposite to the bottom portion 231.

[0063] The first flange 230 is fixed to the heat pipe 220 with the heat pipe 220 inserted through the second peripheral wall portion 235. Specifically, the connection portion between the second flange 240 and the heat pipe 220 is sealed with glass 234.

[0064] The second flange 240 is arranged at a distance from the first flange 230 in the axial direction and has a diameter that expands radially outward from the outer periphery of the heat pipe 220. The second flange 240 is arranged on the other side in the axial direction with respect to the first flange 230. Also, the second flange 240 is arranged on the other side in the axial direction with respect to the terminal portion 225. The second flange 240 includes a bottom portion 241 and a peripheral wall portion 242 that extends from the outer peripheral edge portion of the bottom portion 241 to the other side in the axial direction. The connection portion between the second flange 240 and the heat pipe 220 is sealed with glass 244.

[0065] The housing 260 houses the ceramic heater 211. The housing 260 constitutes a part of the flow path FC through which the liquid flows. The housing 260 fixes the ceramic heater 211 in a watertight manner via the first flange 230. Also, the housing 260 fixes the ceramic heater 211 via the second flange 240. Specifically, the housing 260 may fix the ceramic heater 211 in a watertight manner via the second flange 240.

[0066] The housing 260 includes a second housing 280 and a first housing 290 that are formed separately. The first housing 290 is assembled to the second housing 280. The second housing 280 is hermetically fitted to the first flange 230.

[0067] The first housing 290 houses a portion of the obstruction pipe 220 that is opposite to the portion where the first flange 230 and the terminal portion 225 are arranged in the axial direction. The second flange 240 is housed in the first housing 290 together with the obstruction pipe 220. The heating portion 228 is arranged on the other side of the obstruction pipe 220 in the axial direction from the first flange 230 and on one side of the obstruction pipe 220 in the axial direction from the second flange 240. An outflow hole 229 that constitutes a part of the flow path FC is formed between the heating portion 228 and the second flange 240 in the obstruction pipe 220.

[0068] The first housing 290 includes an obstruction pipe housing portion 291 that houses the heating portion 228 and the second flange 240 of the obstruction pipe 220, a discharge pipe 292 formed to communicate with the obstruction pipe housing portion 291, a base wall 293 that extends radially outward from one end of the obstruction pipe housing portion 291 in the axial direction, and a surrounding wall 294 that extends in one direction in the axial direction from the base wall 293.

[0069] A part of the second housing 280 described later is housed in the space formed by the base wall 293 and the surrounding wall 294. A female screw portion is formed on the inner peripheral surface of the surrounding wall 294, and the female screw portion is adapted to be screwed with a male screw portion formed on the outer peripheral surface of the second housing 280. A seal groove for arranging the seal member S3 is formed between the female screw portion and the base wall 293 on the inner peripheral surface of the surrounding wall 294. This seal member S3 is annular and hermetically seals between the outer peripheral surface of the second housing 280 and the inner peripheral surface of the surrounding wall 294.

[0070] A first contact portion 295 that contacts the clamping portion 233 of the first flange 230 from the other side in the axial direction is formed on the first housing 290. The first contact portion 295 may protrude, for example, in one direction in the axial direction from the base wall 293.

[0071] The second housing 280 includes a base wall 281 extending in the radial direction and an enclosing wall 282 extending from the base wall 281 to one side in the axial direction. A second abutting portion 284 that abuts against the clamping portion 233 from one side in the axial direction is formed on the base wall 281. The clamping portion 233 is clamped in the axial direction by the first abutting portion 295 and the second abutting portion 284. That is, the first flange 230 is fixed in the axial direction by the second housing 280 and the first housing 290.

[0072] An annular seal member S1 is attached between the first peripheral wall portion 232 of the first flange 230 and the second housing 280. The seal member S1 is compressed in the radial direction by the first peripheral wall portion 232 and the second housing 280. The seal member S1 can prevent liquid from leaking from the inside of the first housing 290 to the inside of the second housing 280. Therefore, it is possible to prevent the liquid flowing through the flow path FC from leaking to the terminal portion 225 side.

[0073] <Embodiment 3> Embodiment 3 of the present disclosure will be described with reference to FIG. 6. In the following description, for the configuration corresponding to that of Embodiment 1, the reference numerals of Embodiment 1 will be used with 300 added to the numerical part, and the description of the same configuration as that of Embodiment 1 may be omitted.

[0074] The heat exchanger 310 of Embodiment 3 includes a ceramic heater 311 and a housing 360 that houses the ceramic heater 311. In Embodiment 1, the second housing 80 and the third housing 70 were formed separately, but in Embodiment 3, a second housing 280 in which the second housing 80 and the third housing 70 are integrated is provided.

[0075] The ceramic heater 311 includes a honeycomb tube 320, a first flange 330, a second flange 340, and a terminal portion 325.

[0076] The first flange 330 includes a bottom portion 331 and a peripheral wall portion 332. A through hole 331A that axially penetrates the bottom portion 331 is formed in the first flange 330. The peripheral wall portion 332 has a substantially cylindrical shape and extends to the other side in the axial direction from the outer peripheral edge portion of the bottom portion 331.

[0077] The first flange 330 is fixed to the obstruction tube 320 with the obstruction tube 320 inserted through the through hole 331A. Specifically, the first flange 330 is fixed to the obstruction tube 320 by filling the space formed by the bottom portion 331, the peripheral wall portion 332, and the outer peripheral surface of the obstruction tube 320 with glass 334. The first flange 330 is disposed on one side (the left side in the illustration of FIG. 6) in the axial direction of the obstruction tube 320 and has an enlarged diameter radially outward from the outer periphery of the obstruction tube 320. The terminal portion 325 is disposed on one side in the axial direction with respect to the first flange 330.

[0078] The second flange 340 generally has a cylindrical shape. The second flange 340 includes a main body portion 341 having a cylindrical shape and a plurality of annular ribs 342 formed on the outer peripheral surface of the main body portion 341. The annular ribs 342 protrude radially outward from the outer peripheral surface of the main body portion 341, and a plurality of them are arranged at equal intervals in the axial direction of the obstruction tube 320. Three annular ribs 342 are illustrated in the present embodiment. The second flange 340 is fixed to the obstruction tube 320 with one end in the axial direction of the obstruction tube 320 inserted into the second flange 340.

[0079] The housing 360 includes a second housing 380 and a first housing 390 that are formed separately. The first housing 390 is assembled to the second housing 380. The first housing 390 is watertightly fitted to the first flange 330.

[0080] The first housing 390 houses a portion of the obstruction tube 320 that is opposite to the portion where the terminal portion 325 and the second flange 340 are disposed in the axial direction. The heating portion 328 is disposed on the other side in the axial direction of the obstruction tube 320 with respect to the first flange 330.

[0081] The first housing 390 includes a heat pipe housing portion 391 that houses the heating portion 328 of the heat pipe 320, a discharge pipe 392 formed to communicate with the heat pipe housing portion 391, a base wall 393 that extends radially outward from one end of the heat pipe housing portion 391 in the axial direction, and a surrounding wall 394 that extends axially on one side from the base wall 393.

[0082] The first flange 330 is housed in the space formed by the base wall 393 and the surrounding wall 394. A male screw portion is formed on the outer peripheral surface of the surrounding wall 394. The male screw portion is adapted to be screwed with a female screw portion formed on the inner peripheral surface of a surrounding wall 382 of the second housing 380 described later. A seal member S1 is disposed between the inner peripheral surface of the surrounding wall 394 and the outer peripheral surface of the peripheral wall portion 332 of the first flange 330. The seal member S1 is annular and hermetically seals the space between the outer peripheral surface of the peripheral wall portion 332 and the inner peripheral surface of the surrounding wall 394.

[0083] On the radially inner side of the base wall 393 of the first housing 390, a first abutting portion 395 is formed to abut against the peripheral wall portion 332 of the first flange 330 from the other side in the axial direction.

[0084] The second housing 380 includes a base wall 381 that extends in the radial direction, a surrounding wall 382 that extends axially on the other side from the outer peripheral edge of the base wall 381, and a cylindrical pipe 383 that penetrates the base wall 381 in the axial direction. A fixing wall 384 for fixing the second flange 340 is formed at the other end of the pipe 383 in the axial direction. The fixing wall 384 has a cylindrical shape with a larger diameter than the pipe 383 and is formed to communicate with the pipe 383.

[0085] Inside the surrounding wall 382 and on the other side in the axial direction from the fixed wall 384, a holding member 385 is fixed. When the second housing 380 is attached to the first housing 390, the peripheral wall portion 332 of the first flange 330 is sandwiched between the holding member 385 and the first abutting portion 395, so that the first flange 330 is fixed to the housing 360. At the same time, the second flange 340 is housed inside the fixed wall 384, so that the second flange 340 is fixed to the housing 360. Further, the pipeline 383 communicates with the inside of the obstruction pipe 320 to constitute a part of the flow path FC.

[0086] The sealing member S1 is compressed in the radial direction by the outer peripheral surface of the peripheral wall portion 332 of the first flange 330 and the inner peripheral surface of the surrounding wall 394 of the first housing 390. That is, the first flange 330 is fixed in the radial direction by the surrounding wall 394 of the first housing 390. The sealing member S1 can prevent liquid from leaking from the inside of the first housing 390 to the inside of the second housing 380. Therefore, it is possible to prevent the liquid passing through the flow path FC from leaking to the terminal portion 325 side.

[0087] <Other Embodiments> (1) In Embodiment 1, the first flange 30 and the second flange 40 were each fixed to the obstruction pipe 20 by glass 34, 44, but the first flange and the second flange may be fixed to the obstruction pipe by other fixing members. Also, in the embodiment, the spacer 50 was provided, but the second flange may be fixed to the obstruction pipe without using the spacer.

[0088] (2) The shapes of the first flange, the second flange, and the obstruction pipe may be changed as appropriate.

[0089] (3) In Embodiment 1, the housing 60 included the third housing 70, the second housing 80, and the first housing 90, but the housing may be composed of 2 or less or 4 or more members. Also, the shape of the housing may be changed as appropriate.

[0090] (4) In the first embodiment, the third housing 70 and the second housing 80 are assembled to each other by screwing the male screw portion 82A and the female screw portion 72B, and the third housing 70 and the first housing 90 are assembled to each other by screwing the male screw 72A and the female screw portion 94A. However, each housing may be assembled by other assembling methods.

Explanation of Signs

[0091] 10, 210, 310... Heat exchanger 11, 211, 311... Ceramic heater 20, 220, 320... Porous tube 21, 211... Ceramic tube 22, 222... Ceramic layer 23... Heater pattern layer 24... Internal terminal 25, 225, 325... Terminal portion 26... Ceramic sheet 27... Conductor layer 28... Heating portion 229... Outlet hole 30, 230, 330... First flange 31, 231, 331... Bottom portion 31A, 331A... Through hole 32, 332... Peripheral wall portion 33, 233... Clamping portion 34, 234, 334... Glass 232... First peripheral wall portion 235... Second peripheral wall portion 40, 240, 340... Second flange 41... Large diameter portion 42... Small diameter portion 43... Connecting portion 44, 244... Glass 341... Main body portion 241... Bottom portion 242... Peripheral wall portion 342... Annular rib 50... Spacer 51... Cylindrical portion 52... Flange portion 60, 260, 360... Housing 70... Third housing 71... Base wall 72... Surrounding wall 72A... Male screw portion 72B... Female screw portion 73... First accommodating portion 73A... First cylindrical portion 73B... Second cylindrical portion 73C... Third cylindrical portion 74... Second abutting portion 80, 280, 380... Second housing 81, 281, 381... Base wall 82, 282, 383... Surrounding wall 82A... Male screw portion 83... Second accommodating portion 83A... First cylindrical portion 83B... Second cylindrical portion 284... Second abutting portion 383... Pipe 384... Fixed wall 385... Holding member 90, 290, 390... First housing 91, 291, 391... Porous tube accommodating portion 92, 292, 392... Discharge pipe 93, 293, 393... Base wall 94, 294, 394... Surrounding wall 94A... Female screw portion 94B... Seal groove 95, 295, 395... First abutting portion AX... Axis FC... Flow path, FC1... First flow path, FC2... Second flow path S1, S2, S3... Sealing members

Claims

1. A ceramic heater comprising: a refractory tube extending in the axial direction and having a cylindrical shape; a first flange disposed on one side of the refractory tube in the axial direction and having a diameter that expands radially outward from the outer periphery of the refractory tube; a terminal portion disposed on one side of the refractory tube in the axial direction relative to the first flange; and a heating portion disposed on the other side of the refractory tube in the axial direction relative to the first flange. A heat exchanger mounted on a vehicle, comprising: a housing that houses the refractory tube and to which the ceramic heater is watertightly fixed via the first flange. The ceramic heater is spaced apart from the first flange in the axial direction and includes a second flange having a diameter that expands radially outward from the outer periphery of the refractory tube, and is fixed to the housing via the second flange.

2. The heat exchanger according to claim 1, wherein the first flange and the second flange are fixed to the inner peripheral surface of the housing via a sealing member disposed on their outer peripheries.

3. The heat exchanger according to claim 1, wherein the second flange is disposed on one side of the terminal portion in the axial direction.

4. The heat exchanger according to claim 3, wherein the second flange is watertightly fixed to the housing.

5. The heat exchanger according to claim 1, wherein the second flange is disposed on the other side of the terminal portion in the axial direction.

6. The housing includes: a first housing that houses the refractory tube; a third housing that is assembled to the first housing and is watertightly fixed to the first flange; and a second housing that is formed separately from the third housing and is fixed to the second flange. The heat exchanger according to any one of claims 1 to 3, wherein the first flange has a clamping portion that is clamped between the first housing and the third housing in the axial direction.

7. The housing includes: a first housing that houses the refractory tube; and a second housing that is fixed to the second flange. The heat exchanger according to any one of claims 1 to 3, wherein the first flange has a clamping portion that is clamped between the first housing and the second housing in the axial direction.

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