Heat exchanger

Abstract

Provided is a heat exchanger capable of suppressing stress concentration on a fixed portion of a ceramic heater. The heat exchanger (10) is provided with a ceramic heater (11). A first flange (30) which is disposed on one side of the insulating tube in the axial direction and which expands in diameter from the outer circumference of the insulating tube to the outside in the radial direction; and a terminal part (25) which is disposed on one side of the insulating tube in the axial direction than the first flange (30). And a heating section (28) disposed further toward the other side in the axial direction of the insulating tube than the first flange. And a housing (60) that accommodates the insulating tube and fixes the ceramic heater (11) in a watertight manner via a first flange, the heat exchanger (10) is mounted on the vehicle, the ceramic heater is provided with a second flange (40) that is disposed so as to be separated from the first flange in the axial direction and that expands in diameter from the outer circumference of the insulating tube to the outside in the radial direction, and the ceramic heater is fixed to the housing via the second flange.

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 (hereinafter referred to as Patent Document 1) has been known. The electric heating type hot water heating device of Patent Document 1 includes a housing having a heat medium inlet, a flow path, and an outlet, 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 housing by attaching the flange to the inner peripheral surface of an insertion port provided in the housing via a sealing member such as an O-ring.

[0003] Prior Art Documents

[0004] Patent Documents

[0005] Patent Document 1: Japanese Patent Application Laid-Open No. 2013-126844 Summary of the Invention

[0006] Problems to be Solved by the Invention

[0007] In the above structure, the ceramic heater is fixed to the housing via a single flange. Therefore, for example, when the electric heating type hot water heating device is for vehicle use, there is a concern that stress may concentrate on the fixing portion between the flange and the housing or the fixing portion between the ceramic heater and the flange due to vibrations of the vehicle or the like.

[0008] 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.

[0009] Means for Solving the Problems

[0010] The heat exchanger of the present disclosure includes: a ceramic heater including an insulating tube extending in the axial direction and having a cylindrical shape, a first flange disposed on one side in the axial direction of the insulating tube and having a diameter enlarged radially outward from the outer periphery of the insulating tube, a terminal portion disposed on a side closer to the insulating tube than the first flange in the axial direction, and a heating portion disposed on a side farther from the insulating tube than the first flange in the axial direction; and a housing that houses the insulating tube and watertightly fixes the ceramic heater via the first flange. The heat exchanger is mounted on a vehicle, wherein the ceramic heater includes a second flange disposed separately from the first flange in the axial direction and having a diameter enlarged radially outward from the outer periphery of the insulating tube, and the ceramic heater is fixed to the housing via the second flange.

[0011] Effects of the Invention

[0012] According to the present disclosure, a heat exchanger capable of suppressing stress concentration in a fixing portion of a ceramic heater can be provided. BRIEF DESCRIPTION OF THE DRAWINGS

[0013] Figure 1 FIG. 1 is a cross-sectional view showing an overall structure of a heat exchanger according to Embodiment 1.

[0014] Figure 2 FIG. 2 is a cross-sectional view of the heat exchanger showing an internal structure of the ceramic heater.

[0015] Figure 3 FIG. 3 is an explanatory view for explaining a manufacturing process of an insulating tube.

[0016] Figure 4 FIG. 4 is an enlarged cross-sectional view of the ceramic heater showing mounting portions of a first flange and a second flange.

[0017] Figure 5 FIG. 5 is a cross-sectional view of the heat exchanger showing an internal structure of the ceramic heater according to Embodiment 2.

[0018] Figure 6 FIG. 6 is a cross-sectional view of the heat exchanger showing an internal structure of the ceramic heater according to Embodiment 3. DETAILED DESCRIPTION

[0019] [Description of Embodiments of the Present Disclosure]

[0020] First, embodiments of the present disclosure will be described by way of example.

[0021] (1) The heat exchanger of the present disclosure includes: a ceramic heater including an insulating tube extending in an axial direction and having a cylindrical shape, a first flange disposed on one side in the axial direction of the insulating tube and having a diameter enlarged radially outward from an outer periphery of the insulating tube, a terminal portion disposed on a side closer to the insulating tube than the first flange in the axial direction, and a heating portion disposed on a side farther from the insulating tube than the first flange in the axial direction; and a housing that houses the insulating tube and watertightly fixes the ceramic heater via the first flange. The heat exchanger is mounted on a vehicle. The ceramic heater includes a second flange disposed separately from the first flange in the axial direction and having a diameter enlarged radially outward from the outer periphery of the insulating tube, and the ceramic heater is fixed to the housing via the second flange.

[0022] According to such a structure, since the ceramic heater is fixed to the housing by the first flange and the second flange, the stress acting on the fixing portion between the ceramic heater and the housing in a vibration environment can be dispersed to two places. In addition, compared with the case where only one fixing portion is provided between the flange and the insulating tube, the stress can be dispersed to the fixing portion between the first flange and the insulating tube and the fixing portion between the second flange and the insulating tube, respectively.

[0023] (2) In the heat exchanger according to (1), preferably, 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.

[0024] According to such a structure, the first flange and the second flange can be fixed to the housing in a watertight manner.

[0025] (3) In the heat exchanger according to (1), preferably, the second flange is disposed on the side in the axial direction closer to the axis than the terminal portion.

[0026] According to such a structure, the space between the first flange and the second flange that are separately disposed in the axial direction can be effectively utilized, and the heat exchanger can be miniaturized.

[0027] (4) In the heat exchanger according to (3), preferably, the second flange is fixed to the housing in a watertight manner.

[0028] By fixing the first flange and the second flange to the housing in a watertight manner, water leakage to the terminal portion disposed between the first flange and the second flange can be prevented.

[0029] (5) In the heat exchanger according to (1), preferably, the second flange is disposed on the other side in the axial direction closer to the axis than the terminal portion.

[0030] According to such a structure, by fixing the side in the axial direction closer to the axis than the terminal portion with the first flange and fixing the other side in the axial direction closer to the axis than the terminal portion with the second flange, it is easy to suppress the vibration on the other side of the ceramic heater, and the concentration of stress on the fixing portion between the ceramic heater and the first flange can be suppressed.

[0031] (6) In the heat exchanger according to any one of (1) to (3), preferably, the housing includes a first housing that houses the insulating tube, a third housing that is assembled to the first housing and is fixed to the first flange in a watertight manner, and a second housing that is formed separately from the third housing and is fixed to the second flange. The first flange has a clamping portion that is clamped between the first housing and the third housing in the axial direction.

[0032] According to such a structure, the heat exchanger is easily assembled. In addition, the ceramic heater can be positioned in the axial direction.

[0033] (7) In the heat exchanger according to any one of (1) to (3), preferably, the housing has a first housing that houses the insulating tube and a second housing that is fixed to the second flange, and the first flange has a clamping portion that is clamped between the first housing and the second housing in the axial direction.

[0034] According to such a structure, the first flange can be fixed to the housing by clamping the clamping portion with the first housing and the second housing.

[0035] [Details of Embodiments of the Present Disclosure]

[0036] <Embodiment 1>

[0037] Refer to Figures 1 to 4 Embodiment 1 of the present disclosure will be described. It should be noted that the present disclosure is not limited to these examples, but is represented by the claims, and is intended to include all modifications within the meaning and scope equivalent to the claims. In the following description, for multiple identical components, sometimes only some of the components are labeled with reference numerals and the reference numerals of other components are omitted.

[0038] <Heat Exchanger>

[0039] The heat exchanger 10 according to the present embodiment is a device for heating liquids 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 Figure 1 And Figure 2 shown, the heat exchanger 10 includes a ceramic heater 11 and a housing 60 that houses the ceramic heater 11.

[0040] <Ceramic Heater>

[0041] The ceramic heater 11 includes an insulating tube 20, a first flange 30, a second flange 40, and a terminal portion 25. The insulating tube 20 has a cylindrical shape centered on the axis AX. The insulating tube 20 extends in the axial direction (the direction in which the axis AX extends). The insulating tube 20 includes a ceramic tube 21 having a cylindrical shape and a ceramic layer 22 that covers substantially the entire outer circumference of the ceramic tube 21. The ceramic tube 21 and the ceramic layer 22 are made of a ceramic material such as alumina, for example.

[0042] As Figure 3 shown, a heater pattern layer 23 and a pair of internal terminals 24 are formed on the inner circumferential surface (the surface on the ceramic tube 21 side) or inside of the ceramic layer 22. The heater pattern layer 23 has a meandering thin line shape. The internal terminals 24 have a rectangular shape wider than the heater pattern layer 23. These internal terminals 24 are electrically connected to the terminal portion 25 via a via conductor (not shown) or the like. The terminal portion 25 is formed on the outer circumferential surface of the ceramic layer 22.

[0043] The insulating tube 20 can be manufactured, for example, by firing a member obtained by winding ceramic sheets 26 around a ceramic tube 21 that has been pre-temporarily fired. A conductor layer 27 such as tungsten is formed on the surface or inside of the ceramic sheet 26. The conductor layer 27 becomes the heater pattern layer 23, the internal terminal 24, and the terminal portion 25 after firing.

[0044] The first flange 30 is, for example, a ring-shaped member made of a metal such as stainless steel. The first flange 30 has a generally cup shape. The first flange 30 includes a bottom portion 31, a peripheral wall portion 32, and a clamping portion 33. As Figure 4 shown, 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 generally cylindrical shape and extends in the axial direction from the outer peripheral edge portion of the bottom portion 31. The clamping portion 33 is plate-shaped 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 refers to the direction that is orthogonal to the axial direction and is the direction in which a hypothetical axis intersecting the axis AX extends. The radially outer side refers to the orientation along the hypothetical axis away from the axis AX. The radially inner side refers to the orientation along the hypothetical axis approaching the axis AX.

[0045] The first flange 30 is fixed to the insulating tube 20 with the insulating tube 20 inserted through the through hole 31A. Specifically, the first flange 30 is fixed to the insulating tube 20 by filling the space formed by the bottom portion 31, the peripheral wall portion 32, and the outer peripheral surface of the insulating tube 20 with glass 34. The first flange 30 is disposed on one side in the axial direction of the insulating tube 20 ( Figure 1 and Figure 2 the left side in the illustration), and expands in diameter radially outward from the outer periphery of the insulating tube 20. As Figure 1 shown, the terminal portion 25 is disposed on the side closer to the axial direction than the first flange 30.

[0046] The second flange 40 is, for example, a ring-shaped member made of a metal such as stainless steel. The second flange 40 has a generally cylindrical shape. 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 is stepped and connects the large-diameter portion 41 and the small-diameter portion 42 in the axial direction.

[0047] As Figure 4 shown, the second flange 40 is fixed to the insulating tube 20 with one end portion in the axial direction of the insulating tube 20 inserted into the inside of the second flange 40. Specifically, the second flange 40 is fixed to the insulating tube 20 by filling the space surrounded by the outer peripheral surface of the insulating 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.

[0048] The outer diameter of the insulating 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 insulating 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 for accumulating the glass 44 for fixing the second flange 40 to the insulating tube 20 is formed. The spacer 50 includes a cylindrical portion 51 that is cylindrical 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 insulating tube 20. The flange portion 52 is disposed in a state of being in contact with the inner peripheral surface of the connecting portion 43.

[0049] The second flange 40 is disposed separately from the first flange 30 in the axial direction and has a diameter that expands radially outward from the outer periphery of the insulating tube 20. The second flange 40 is disposed on the side in the axial direction closer to the first flange 30. In addition, as Figure 1 shown, the second flange 40 is disposed on the side in the axial direction closer to the terminal portion 25.

[0050] At the connection portions (i.e., the portions sealed by the glass 34, 44) between the respective flanges 30, 40 and the insulating tube 20 in the ceramic heater 11, liquid leakage is prevented. As the glass 34, 44, for example, a glass of the Na2O·Al2O3·B2O3·SiO2 system, a so-called glass of the Al2O3·B2O3·SiO2 system (borosilicate glass) is used.

[0051] <Housing>

[0052] As Figure 1 and Figure 2 shown, the housing 60 houses the ceramic heater 11. The housing 60 forms a part of the flow path FC through which the liquid flows. The housing 60 fixes the ceramic heater 11 in a watertight manner via the first flange 30. In addition, the housing 60 fixes the ceramic heater 11 via the second flange 40. Specifically, the housing 60 can 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 the fixing portion and liquid leakage through the fixing portion is prevented.

[0053] 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 the fitting portion and liquid leakage through the fitting portion is prevented.

[0054] <First Housing>

[0055] The first housing 90 houses a portion of the insulating tube 20 that is on the opposite side in the axial direction from the portions where the first flange 30, the terminal portion 25, and the second flange 40 are disposed. As Figure 3 shown, the portion of the insulating tube 20 disposed within the first housing 90 is the portion that includes most of the heater pattern layer 23 and is the portion that is mainly heated by energizing the ceramic heater 11 (hereinafter referred to as the heating portion 28). As Figure 1 and Figure 2 shown, the heating portion 28 is disposed on the other side in the axial direction of the insulating tube 20 from the first flange 30 ( Figure 1 and Figure 2 the right side in the illustration).

[0056] As Figure 1 and Figure 2 shown, the first housing 90 includes an insulating tube housing portion 91 that houses the heating portion 28 of the insulating tube 20, a discharge pipe 92 formed to communicate with the insulating tube housing portion 91, a base wall 93 that extends radially outward from one end of the insulating tube housing portion 91 in the axial direction, and an enclosing wall 94 that extends from the base wall 93 in the axial direction. The insulating tube housing portion 91 has a bottomed cylindrical shape. The inner diameter of the insulating tube housing portion 91 is formed to be larger than the outer diameter of the insulating tube 20. The discharge pipe 92 extends radially outward from one end of the insulating tube housing portion 91 in the axial direction, for example.

[0057] A portion of the third housing 70 described later is housed in the space formed by the base wall 93 and the enclosing wall 94. An internal thread portion 94A is formed on the inner peripheral surface of the enclosing wall 94. The internal thread portion 94A is screwed with an external thread portion 72A formed on the outer peripheral surface of the third housing 70. A sealing groove 94B for disposing the sealing member S3 is formed on the inner peripheral surface of the enclosing wall 94 between the internal thread portion 94A and the base wall 93. The sealing 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 enclosing wall 94.

[0058] A first abutting portion 95 that abuts against the clamping portion 33 of the first flange 30 is formed on the first housing 90 from the other side in the axial direction ( Figure 1 and Figure 2 the right side in the illustration). The first abutting portion 95 can project from the base wall 93 toward one side in the axial direction, for example.

[0059] <The third housing>

[0060] 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 receiving portion 73 is formed in the third housing 70 so as to penetrate the base wall 71. The first receiving portion 73 includes a first cylindrical portion 73A through which the insulating tube 20 is inserted, a second cylindrical portion 73B that receives the peripheral wall portion 32 of the first flange 30, and a third cylindrical portion 73C that receives the clamping portion 33. 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.

[0061] The inner peripheral surface of the second cylindrical portion 73B watertightly fixes the peripheral wall portion 32 of the first flange 30 via a sealing member S1. In other words, an annular sealing member S1 is mounted on 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 the sealing member S1. Alternatively, the sealing member S1 may be fitted into a sealing groove (not shown) provided on the inner peripheral surface of the second cylindrical portion 73B. The sealing 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. Through the sealing member S1, it is possible to prevent liquid from leaking from the first housing 90 side of the first receiving portion 73 to one side in the axial direction. Thus, it is possible to prevent the liquid flowing through the flow path FC from leaking to the terminal portion 25 side.

[0062] A second abutting portion 74 that abuts against the clamping portion 33 of the first flange 30 from one side in the axial direction is formed in the third housing 70. The second abutting portion 74 is disposed 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.

[0063] The terminal portion 25, a wiring member (not shown) connected to the terminal portion 25, and a part of the second housing 80 described later are disposed in the space formed by the enclosing wall 72 and the base wall 71. A male thread portion 72A is formed on the outer peripheral surface of the enclosing wall 72. The male thread portion 72A is disposed at a position near the other end in the axial direction in the enclosing wall 72. The male thread portion 72A is screwed with the female thread portion 94A of the first housing 90. A female thread portion 72B is formed on the inner peripheral surface of the enclosing wall 72. The female thread portion 72B is screwed with the male thread portion 82A formed on the outer peripheral surface of the second housing 80. The female thread portion 72B is disposed at a position near the one end in the axial direction in the enclosing wall 72. In addition, a through hole (not shown) for leading out the wiring member to the outside may be formed in the enclosing wall 72.

[0064] <The second housing>

[0065] The second housing 80 includes a base wall 81 extending in the radial direction and an enclosing 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 that accommodates the large-diameter portion 41 of the second flange 40. The inner diameter of the second cylindrical portion 83B is larger than the inner diameter of the first cylindrical portion 83A. 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. Alternatively, the entire connecting portion 43 may be accommodated in the second cylindrical portion 83B.

[0066] The inner peripheral surface of the second cylindrical portion 83B watertightly fixes the large-diameter portion 41 of the second flange 40 via a sealing member S2. In other words, an annular sealing member S2 is installed on 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 the sealing member S2. Alternatively, the sealing member S2 may be fitted into a sealing groove (not shown) provided on the inner peripheral surface of the second cylindrical portion 83B. The sealing member S2 is compressed in the radial direction 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 fixed in the radial direction by the second cylindrical portion 83B of the second housing 80. By the sealing member S2, it is possible to prevent liquid from leaking from one side to the other side in the axial direction of the second accommodating portion 83. Thereby, it is possible to prevent the liquid passing through the flow path FC from leaking to the terminal portion 25 side.

[0067] The small-diameter portion 42 of the second flange 40 is disposed in the space formed by the enclosing wall 82 and the base wall 81. An external thread portion 82A is formed on the outer peripheral surface of the enclosing wall 82. The external thread portion 82A is disposed at a position close to the other end portion in the axial direction of the enclosing wall 82. The external thread portion 82A is screwed with the internal thread portion 72B of the third housing 70.

[0068] As Figure 2 shown, 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 insulating tube 20. The second flow path FC2 is watertightly sealed by the sealing members S1 and S3. As shown by the arrow, the liquid is introduced from the small-diameter portion 42, enters the second flow path FC2 through the heating portion 28 of the insulating tube 20. Thereafter, the liquid advances toward one side in the axial direction while being in thermal contact with the outer peripheral surface of the heating portion 28, 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 also have a connecting flow path (not shown) that liquid-tightly connects between the discharge pipe 92 and the small-diameter portion 42, or may be configured such that the liquid circulates in the flow path FC.

[0069] <Effect of Embodiment 1>

[0070] As described above, the heat exchanger 10 of Embodiment 1 includes: a ceramic heater 11 having an insulating tube 20 extending in the axial direction and having a cylindrical shape, a first flange 30 disposed on one side in the axial direction of the insulating tube 20 and having a diameter enlarged radially outward from the outer periphery of the insulating tube 20, a terminal portion 25 disposed on the side closer to the axial direction of the insulating tube 20 than the first flange 30, and a heating portion 28 disposed on the other side closer to the axial direction of the insulating tube 20 than the first flange 30; and a housing 60 that houses the insulating tube 20 and watertightly fixes the ceramic heater 11 via the first flange 30. The heat exchanger 10 is mounted on a vehicle. Among them, the ceramic heater 11 includes a second flange 40 that is disposed separately from the first flange 30 in the axial direction and has a diameter enlarged radially outward from the outer periphery of the insulating tube 20, and the ceramic heater 11 is fixed to the housing 60 via the second flange 40.

[0071] According to such a structure, since the ceramic heater 11 is fixed to the housing 60 by the first flange 30 and the second flange 40, the stress acting on the fixing portion between the ceramic heater 11 and the housing 60 in a vibration environment can be dispersed to two places. In addition, compared with the case where only one fixing portion between the flange and the insulating tube is provided, the stress can be dispersed to the fixing portion between the first flange 30 and the insulating tube 20 and the fixing portion between the second flange 40 and the insulating tube 20, respectively.

[0072] In Embodiment 1, the first flange 30 and the second flange 40 are fixed to the inner peripheral surface of the housing 60 via sealing members S1 and S2 disposed on their outer peripheries.

[0073] According to such a structure, the first flange 30 and the second flange 40 can be watertightly fixed to the housing 60.

[0074] In Embodiment 1, the second flange 40 is disposed on the side closer to the axial direction than the terminal portion 25 and is watertightly fixed to the housing 60.

[0075] According to such a structure, the space between the first flange 30 and the second flange 40 disposed separately in the axial direction can be effectively utilized, and the heat exchanger 10 can be miniaturized. In addition, by watertightly fixing the first flange 30 and the second flange 40 to the housing 60, leakage of water to the terminal portion 25 disposed between the first flange 30 and the second flange 40 can be prevented.

[0076] 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.

[0077] With such a structure, the heat exchanger 10 can be easily assembled.

[0078] In Embodiment 1, the housing 60 further includes a first housing 90 assembled to the third housing 70, and the first flange 30 has a clamping portion 33 clamped by the third housing 70 and the first housing 90 in the axial direction.

[0079] With such a structure, the ceramic heater 11 can be positioned in the axial direction.

[0080] <Embodiment 2>

[0081] Refer to Figure 5 Embodiment 2 of the present disclosure will be described. In the following description, for the structure corresponding to Embodiment 1, reference numerals obtained by adding 200 to the numerical part of the reference numerals in the drawings of Embodiment 1 are used, and for the same structure as in Embodiment 1, the description thereof may be omitted sometimes.

[0082] The heat exchanger 210 of Embodiment 2 includes a ceramic heater 211 and a housing 260 that houses the ceramic heater 211. In Embodiment 1, the second flange 40 is disposed on one side in the axial direction of the insulating tube 20 ( Figure 1 and Figure 2 the left side in the drawing), but in Embodiment 2, the second flange 240 is disposed on the other side in the axial direction of the insulating tube 220 ( Figure 5 the right side in the drawing).

[0083] The ceramic heater 211 includes an insulating tube 220, a first flange 230, a second flange 240, and a terminal portion 225.

[0084] 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 opposite to the bottom portion 231.

[0085] The first flange 230 is fixed to the insulating tube 220 with the insulating tube 220 inserted through the second peripheral wall portion 235. Specifically, the connection portion between the first flange 230 and the insulating tube 220 is sealed by glass 234.

[0086] The second flange 240 is arranged separately from the first flange 230 in the axial direction and has a diameter expanded radially outward from the outer periphery of the insulating tube 220. The second flange 240 is arranged on the other side in the axial direction relative to the first flange 230. In addition, the second flange 240 is arranged on the other side in the axial direction relative to the terminal portion 225. The second flange 240 includes a bottom portion 241 and a peripheral wall portion 242 extending from the outer peripheral edge portion of the bottom portion 241 to the other side in the axial direction. The connecting portion between the second flange 240 and the insulating tube 220 is sealed by glass 244.

[0087] The housing 260 houses the ceramic heater 211. The housing 260 forms a part of the flow path FC through which the liquid flows. The housing 260 fixes the ceramic heater 211 watertightly via the first flange 230. In addition, the housing 260 fixes the ceramic heater 211 via the second flange 240. Specifically, the housing 260 can fix the ceramic heater 211 watertightly via the second flange 240.

[0088] The housing 260 includes a second housing 280 and a first housing 290 formed separately. The first housing 290 is assembled to the second housing 280. The second housing 280 is watertightly fitted to the first flange 230.

[0089] The first housing 290 houses the portion of the insulating tube 220 on the side opposite to the portion where the first flange 230 and the terminal portion 225 are arranged in the axial direction. The second flange 240 and the insulating tube 220 are housed together in the first housing 290. The heating portion 228 is arranged on the other side in the axial direction of the insulating tube 220 relative to the first flange 230 and on the side in the axial direction of the insulating tube 220 relative to the second flange 240. An outflow hole 229 forming a part of the flow path FC is formed between the heating portion 228 of the insulating tube 220 and the second flange 240.

[0090] The first housing 290 includes an insulating tube housing portion 291 for housing the heating portion 228 of the insulating tube 220 and the second flange 240, a discharge pipe 292 formed to communicate with the insulating tube housing portion 291, a base wall 293 extending radially outward from the end portion on the side in the axial direction of the insulating tube housing portion 291, and an enclosing wall 294 extending from the base wall 293 to the side in the axial direction.

[0091] A part of the second housing 280 described below is housed in the space formed by the base wall 293 and the enclosing wall 294. An internal thread portion is formed on the inner peripheral surface of the enclosing wall 294, and the internal thread portion is screwed with an external thread portion formed on the outer peripheral surface of the second housing 280. A sealing groove for arranging a sealing member S3 is formed on the inner peripheral surface of the enclosing wall 294 between the internal thread portion and the base wall 293. The sealing member S3 is annular and seals the outer peripheral surface of the second housing 280 and the inner peripheral surface of the enclosing wall 294 in a liquid-tight manner.

[0092] A first abutting portion 295 that abuts against the clamping portion 233 from the other side in the axial direction is formed on the first housing 290. The first abutting portion 295 can protrude from the base wall 293 toward one side in the axial direction, for example.

[0093] 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 toward 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.

[0094] An annular sealing member S1 is installed between the first peripheral wall portion 232 of the first flange 230 and the second housing 280. The sealing member S1 is compressed in the radial direction by the first peripheral wall portion 232 and the second housing 280. Through the sealing member S1, it is possible to prevent liquid from leaking from the inside of the first housing 290 to the inside of the second housing 280. Thus, it is possible to prevent the liquid flowing through the flow path FC from leaking to the terminal portion 225 side.

[0095] <Embodiment 3>

[0096] Refer to Figure 6 Embodiment 3 of the present disclosure will be described. In the following description, for the structure corresponding to Embodiment 1, reference numerals obtained by adding 300 to the numerical part of the reference numerals in the drawings of Embodiment 1 are used, and for the same structure as that in Embodiment 1, the description thereof may be omitted sometimes.

[0097] 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 are formed separately, but in Embodiment 3, a second housing 380 is provided in which the second housing 80 and the third housing 70 are integrated.

[0098] The ceramic heater 311 includes an insulating tube 320, a first flange 330, a second flange 340, and a terminal portion 325.

[0099] The first flange 330 includes a bottom portion 331 and a peripheral wall portion 332. A through hole 331A that penetrates the bottom portion 331 in the axial direction is formed in the first flange 330. The peripheral wall portion 332 is substantially cylindrical and extends from the outer peripheral edge portion of the bottom portion 331 toward the other side in the axial direction.

[0100] The first flange 330 is fixed to the insulating tube 320 with the insulating tube 320 inserted through the through hole 331A. Specifically, the first flange 330 is fixed to the insulating tube 320 by filling the space formed by the bottom 331, the peripheral wall portion 332, and the outer peripheral surface of the insulating tube 320 with glass 334. The first flange 330 is disposed on one side in the axial direction of the insulating tube 320 ( Figure 6 the left side in the illustrated figure), and has a diameter that expands radially outward from the outer periphery of the insulating tube 320. The terminal portion 325 is disposed on one side in the axial direction closer to the insulating tube 320 than the first flange 330.

[0101] The second flange 340 is generally cylindrical. The second flange 340 includes a cylindrical main body portion 341 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 insulating tube 320. In the present embodiment, three annular ribs 342 are illustrated. The second flange 340 is fixed to the insulating tube 320 with one end on the side in the axial direction of the insulating tube 320 inserted into the inside of the second flange 340.

[0102] The housing 360 includes a second housing 380 and a first housing 390 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.

[0103] The first housing 390 houses a portion of the insulating tube 320 on the side 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 insulating tube 320 closer to the first flange 330.

[0104] The first housing 390 includes an insulating tube housing portion 391 that houses the heating portion 328 of the insulating tube 320, a discharge tube 392 formed to communicate with the insulating tube housing portion 391, a base wall 393 that extends radially outward from one end on the side in the axial direction of the insulating tube housing portion 391, and a surrounding wall 394 that extends in the axial direction from the base wall 393.

[0105] The first flange 330 is housed in the space formed by the base wall 393 and the surrounding wall 394. A male thread portion is formed on the outer peripheral surface of the surrounding wall 394. The male thread portion is screwed into a female thread portion formed on the inner peripheral surface of a surrounding wall 382 of the second housing 380 described later. A sealing 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 sealing member S1 is annular and liquid-tightly seals the space between the outer peripheral surface of the peripheral wall portion 332 and the inner peripheral surface of the surrounding wall 394.

[0106] A first contact portion 395 is formed radially inwardly of the base wall 393 of the first housing 390 and abuts against the circumferential wall portion 332 of the first flange 330 from the other side in the axial direction.

[0107] The second housing 380 includes a base wall 381 extending radially, an enclosing wall 382 extending from the outer peripheral edge portion of the base wall 381 to the other side in the axial direction, and a cylindrical pipe 383 penetrating 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 in communication with the pipe 383.

[0108] A holding member 385 is fixed inside the enclosing wall 382 on the other side in the axial direction with respect to the fixing wall 384. When the second housing 380 is attached to the first housing 390, the first flange 330 is fixed to the housing 360 by the circumferential wall portion 332 of the first flange 330 being clamped between the holding member 385 and the first contact portion 395. At the same time, the second flange 340 is fixed to the housing 360 by being received inside the fixing wall 384. In addition, the pipe 383 forms part of the flow path FC by communicating with the inside of the insulating pipe 320.

[0109] The sealing member S1 is compressed radially by the outer peripheral surface of the circumferential wall portion 332 of the first flange 330 and the inner peripheral surface of the enclosing wall 394 of the first housing 390. That is, the first flange 330 is fixed radially by the enclosing wall 394 of the first housing 390. By the sealing member S1, it is possible to prevent liquid from leaking from the inside of the first housing 390 to the inside of the second housing 380. Thus, it is possible to prevent the liquid flowing through the flow path FC from leaking to the terminal portion 325 side.

[0110] <Other Embodiments>

[0111] (1) In Embodiment 1, the first flange 30 and the second flange 40 are fixed to the insulating pipe 20 by glass 34 and 44, respectively, but the first flange and the second flange may also be fixed to the insulating pipe by other fixing members. In addition, in the embodiment, a spacer 50 is provided, but the second flange may be fixed to the insulating pipe without using the spacer.

[0112] (2) The shapes of the first flange, the second flange, and the insulating pipe may also be appropriately changed.

[0113] (3) In Embodiment 1, the housing 60 includes a third housing 70, a second housing 80, and a first housing 90, but the housing may also be composed of two or less or four or more members. In addition, the shape of the housing may also be appropriately changed.

[0114] (4)In Embodiment 1, the third housing 70 and the second housing 80 are assembled with each other by screwing the male thread portion 82A and the female thread portion 72B, and the third housing 70 and the first housing 90 are assembled with each other by screwing the male thread portion 72A and the female thread portion 94A. However, the housings may also be assembled by other assembly methods.

Claims

1. A heat exchanger having: A ceramic heater including an insulating tube extending in an axial direction and having a cylindrical shape, a first flange disposed on one side in the axial direction of the insulating tube and having a diameter expanded radially outward from an outer periphery of the insulating tube, a terminal portion disposed on a side in the axial direction of the insulating tube closer to the first flange, and a heating portion disposed on a side in the axial direction of the insulating tube farther from the first flange; and A housing that houses the insulating tube and watertightly fixes the ceramic heater via the first flange, The heat exchanger is mounted on a vehicle, wherein The ceramic heater includes a second flange disposed separately from the first flange in the axial direction and having a diameter expanded radially outward from an outer periphery of the insulating tube, and the ceramic heater 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 an inner peripheral surface of the housing via a sealing member disposed on an outer periphery thereof.

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

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 a side in the axial direction farther from the terminal portion.

6. The heat exchanger according to any one of claims 1 to 3, wherein The housing includes a first housing that houses the insulating tube, 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, The first flange has a clamped portion clamped in the axial direction by the first housing and the third housing.

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

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