Temperature detection device and assembly thereof

A temperature detection device that can facilitate attachment of a temperature sensor to a coil and can improve thermal responsiveness by a simple structure reduced in the number of components. Such a temperature detection device includes a temperature sensor including a thermosensitive body configured to detect temperature of a coil of a rotary electric machine to be mounted on a vehicle, and a metal bracket attaching the temperature sensor to the coil. The bracket includes a bracket main body clamping the coil by elastic force, and a joining portion joined to the temperature sensor. The bracket main body includes a clamping portion internally clamping the coil, and a heat collection portion that protrudes to outside of the clamping portion and is thermally coupled to the temperature sensor.

This is the National Stage of PCT international application PCT/JP2018/028956 filed on Aug. 2, 2018, the content of which is incorporated herein by reference in its entirety.

TECHNICAL FIELD

The present invention relates to a temperature detection device used to detect temperature of a coil.

BACKGROUND ART

A temperature sensor is used to detect temperature of a coil included in a stator of a rotary electric machine to be mounted on a vehicle or the like (Patent Literature 1). The temperature sensor disclosed in Patent Literature 1 is provided with a resin holder. The holder includes a sensor holder holding the temperature sensor, and an electric wire holder holding a lead wire of the temperature sensor.

One side of a C-shaped metal clip is fixed to the sensor holder disclosed in Patent Literature 1. The temperature sensor can be easily attached to the rectangular coil by clipping the rectangular coil between the sensor holder and a resin pad attached to the other side of the clip.

CITATION LIST

Patent Literature

SUMMARY OF INVENTION

Technical Problem

According to Patent Literature 1, since the plurality of resin components (sensor holder, electric wire holder, and pad) are used in addition to the clip in order to attach the temperature sensor to the coil, the number of components is large.

Further, the resin components are disposed around the coil and the temperature sensor, and heat is conducted from the coil to the temperature sensor through the resin components. Therefore, there is a room for improvement in responsiveness of temperature detection.

An object of the present invention is to provide a temperature detection device that can facilitate attachment of a temperature sensor to a coil and can improve thermal responsiveness by a simple structure reduced in the number of components.

Solution to Problem

A first temperature detection device according to the present invention includes a temperature sensor including a thermosensitive body configured to detect temperature of a coil of a rotary electric machine to be mounted on a vehicle, and a metal bracket attaching the temperature sensor to the coil. The bracket includes a bracket main body clamping the coil by elastic force, and a joining portion joined to the temperature sensor. The bracket main body includes a clamping portion internally clamping the coil, and a heat collection portion that protrudes to outside of the clamping portion and is thermally coupled to the temperature sensor.

In the first temperature detection device according to the present invention, the temperature sensor preferably comes into contact with the coil through a part of the clamping portion.

In the first temperature detection device according to the present invention, the temperature sensor is preferably disposed between a wall that is the part of the clamping portion and a facing portion of the heat collection portion facing the wall.

In the first temperature detection device according to the present invention, the wall and the facing portion preferably extend over a thermosensitive region that includes at least the thermosensitive body of the temperature sensor.

In the first temperature detection device according to the present invention, the heat collection portion preferably conducts heat of the coil to a thermosensitive region that includes at least the thermosensitive body of the temperature sensor.

A second temperature detection device according to the present invention includes a temperature sensor including a thermosensitive body configured to detect temperature of a coil of a rotary electric machine to be mounted on a vehicle, and a metal bracket attaching the temperature sensor to the coil. The bracket includes a bracket main body clamping the coil and the temperature sensor by elastic force, and a joining portion joined to the temperature sensor.

In the second temperature detection device according to the present invention, the bracket main body is preferably provided with a supporting portion supporting the temperature sensor.

In the first and second temperature detection devices according to the present invention, the bracket main body preferably includes a fastened portion fastened to the coil.

A third temperature detection device according to the present invention includes a temperature sensor including a thermosensitive body configured to detect temperature of a coil of a rotary electric machine to be mounted on a vehicle, and a metal bracket attaching the temperature sensor to the coil. The bracket includes a bracket main body that is disposed over a thermosensitive region including at least the thermosensitive body of the temperature sensor and is thermally coupled to the temperature sensor, a joining portion joined to the temperature sensor, and a fastened portion fastened to the coil.

The following configurations are common to the first to third temperature detection devices.

In the temperature detection device according to the present invention, the joining portion is preferably joined to a joined portion of the temperature sensor that is located at a position different from the thermosensitive body.

In the temperature detection device according to the present invention, the joined portion is preferably located at a position of the temperature sensor different from both of the thermosensitive body and an electric wire provided on the thermosensitive body.

In the temperature detection device according to the present invention, the temperature sensor preferably includes a thermosensitive element that includes the thermosensitive body and an electric wire provided on the thermosensitive body, and an insulating protective member provided at least on the thermosensitive body and a part of the electric wire of the thermosensitive element, and the joined portion is preferably located on the protective member.

In the temperature detection device according to the present invention, the joined portion is preferably made of a resin material in a solid state.

In the temperature detection device according to the present invention, the bracket main body is preferably disposed over a thermosensitive region including at least the thermosensitive body of the temperature sensor.

In the temperature detection device according to the present invention, the thermosensitive region preferably further includes a part of an electric wire provided on the thermosensitive body.

In the temperature detection device according to the present invention, the electric wire provided on the thermosensitive body preferably includes a first electric wire connected to the thermosensitive body, and a second electric wire connected to the first electric wire, and the thermosensitive region preferably further includes a whole of the first electric wire.

In the temperature detection device according to the present invention, the temperature sensor preferably extends in a longitudinal direction in which an electric wire provided on the thermosensitive body extends, and is preferably surrounded around an axis line set along the longitudinal direction by the bracket main body.

In the temperature detection device according to the present invention, the bracket is preferably a single member integrally made of a metal plate.

In the temperature detection device according to the present invention, the joining portion preferably includes paired protrusion pieces caulked to the temperature sensor.

In the temperature detection device according to the present invention, the bracket main body is preferably provided with a stopper that prevents separation of the coil.

A first assembly according to the present invention includes a temperature detection device assembled to a coil of a rotary electric machine to be mounted on a vehicle, and a coil element configuring a part of the coil. The temperature detection device includes a temperature sensor including a thermosensitive body configured to detect temperature of the coil, and a metal bracket attaching the temperature sensor to the coil element. The bracket includes a bracket main body clamping the coil by elastic force, and a joining portion joined to the temperature sensor. The bracket main body includes a clamping portion internally clamping the coil, and a heat collection portion that protrudes to outside of the clamping portion and is thermally coupled to the temperature sensor.

A second assembly according to the present invention includes a temperature detection device assembled to a coil of a rotary electric machine to be mounted on a vehicle, and a coil element configuring a part of the coil. The temperature detection device includes a temperature sensor including a thermosensitive body configured to detect temperature of the coil, and a metal bracket attaching the temperature sensor to the coil element. The bracket includes a bracket main body clamping the coil and the temperature sensor by elastic force, and a joining portion joined to the temperature sensor.

A third assembly according to the present invention includes a temperature detection device assembled to a coil of a rotary electric machine to be mounted on a vehicle, and a coil element configuring a part of the coil. The temperature detection device includes a temperature sensor including a thermosensitive body configured to detect temperature of the coil, and a metal bracket attaching the temperature sensor to the coil element. The bracket includes a bracket main body that is disposed over a thermosensitive region including at least the thermosensitive body of the temperature sensor and is thermally coupled to the temperature sensor, a joining portion joined to the temperature sensor, and a fastened portion fastened to the coil.

Advantageous Effects of Invention

The bracket of the temperature detection device according to the present invention that has both of the function of clamping the coil or being fastened to the coil and the function of holding the temperature sensor by joining can be configured in a simple form as one member in which the bracket main body and the joining portion are continues to each other. Using the bracket having the simple configuration makes it possible to hold the temperature sensor by the joining portion, and to clamp the coil in the inside of the bracket main body, thereby easily attaching the temperature sensor to the coil.

In addition, the metal bracket also has the function of collecting the heat of the coil to the temperature sensor because of high thermal conductivity. The thermal responsiveness of temperature detection by the temperature sensor can be improved based on the heat collection action.

DESCRIPTION OF EMBODIMENTS

A temperature detection device according to each of the embodiments described below is attached to a coil provided in a rotary electric machine such as a motor to be mounted on a vehicle such as an automobile, in order to measure temperature of the coil.

First Embodiment

A temperature detection device1according to a first embodiment is described with reference toFIG.1toFIGS.4A,4B.

FIG.1illustrates the temperature detection device1attached to a coil8of an unillustrated stator to which an alternating current is applied.

A part of the coil8is illustrated inFIG.1. The illustrated part corresponds to a bus bar connected to an unillustrated neutral point of u, v, and w phases. The temperature detection device1is attached to a portion (hereinafter, referred to as extending portion8A) of the bus bar extending in one direction.

A temperature sensor10held by a bracket20is attached to the extending portion8A of the coil8.

The extending portion8A extends in a gentle arc shape in a plan view (FIG.2B), and linearly extends in a side view (FIG.2A). As illustrated inFIG.3A, the extending portion8A of the coil8is formed in a rectangular shape, and has a substantially rectangular cross-section.

The extending portion8A may linearly extend in a plan view and a side view (seeFIGS.13A,13BtoFIGS.16A,16B).

A surface of the coil8made of a metal material is typically coated with an unillustrated insulating coating. The coating may be removed over a range of the extending portion8A where the temperature detection device1is attached.

The temperature sensor10has an elongated rectangular-parallelepiped appearance shape. As illustrated inFIG.2A, the temperature sensor10attached to the coil8by the bracket20is disposed along the extending portion8A. In the present embodiment, a case where the temperature sensor10is formed in a rectangular-parallelepiped shape is illustrated; however, the temperature sensor10may be curved in an arc shape so as to extend along the extending portion8A also in a plan view.

In the present specification, a direction in which the extending portion8A of the coil8is clamped by the bracket20is referred to as a clamping direction D1. The clamping direction D1corresponds to a thickness direction of the extending portion8A.

Further, a longitudinal direction of the temperature sensor10is referred to as a front-rear direction D2, and a direction orthogonal to the front-rear direction D2and the clamping direction D1is referred to as a height direction D3. A side of the temperature sensor10on which a thermosensitive body101(FIG.2A) is located is defined as “front”, and a side opposite thereto is defined as “rear”.

In a state where the temperature sensor10is attached to the extending portion8A by the bracket20, the clamping direction D1and the front-rear direction D2are orthogonal to each other.

A configuration of the temperature detection device1is described in detail below.

The temperature detection device1includes the temperature sensor10that detects temperature of the coil8, and the metal bracket20that attaches the temperature sensor10to the coil8.

A configuration of the temperature sensor10is described in detail with reference toFIG.2AandFIG.4A.

The temperature sensor10includes a thermosensitive element11that detects temperature, and an insulating protective member12provided in the thermosensitive element11, and comes into contact with the coil8through the bracket20while being held by the bracket20.

The thermosensitive element11includes the thermosensitive body101and paired electric wires110. The thermosensitive body101includes a thermosensitive portion101A that can detect temperature based on change of electric resistance to the temperature change. The paired electric wires110are electrically connected to an unillustrated electrode provided at the thermosensitive portion101A, and are drawn out rearward from the thermosensitive body101.

The temperature sensor10has an elongated shape along a direction (longitudinal direction) in which the electric wires are drawn out from the thermosensitive body101.

The thermosensitive body101includes the thermosensitive portion101A and a coating glass101B sealing the thermosensitive portion101A. As the thermosensitive portion101A, a resistor such as a thermistor having a predetermined temperature coefficient can be widely used.

The paired electric wires110are drawn out in the same direction (rearward) from the coating glass101B of the thermosensitive body101.

Each of the electric wires110includes a Dumet wire111that is a first electric wire drawn out from the coating glass101B, and a lead wire112that is a second electric wire connected to the Dumet wire111.

Each of the Dumet wires111is obtained by joining a rolled copper alloy coating with a core wire made of an iron-nickel alloy having a linear expansion coefficient close to a linear expansion coefficient of the coating glass101B. As each of the first electric wires, in place of the Dumet wire111, a wire material made of platinum or a platinum alloy may be used, or a platinum clad wire obtained by joining a rolled platinum coating may be used in place of a core wire made of an iron-nickel alloy.

Each of the lead wires112includes a core wire112A made of twisted wires or the like, and an insulating coating112B coating the core wire112A. The core wires112A are electrically connected to the respective Dumet wires111. In the present embodiment, ends of the Dumet wires111are joined to respective pads112C connected to the core wires112A by welding or the like. As a result, the Dumet wires111and the respective core wires112A are electrically connected. Each of the lead wires112is connected to an unillustrated circuit substrate through the other electric wire as necessary.

The protective member12covers the thermosensitive element11over the thermosensitive body101, the Dumet wires111drawn out from the thermosensitive body101, and a part of the lead wires112connected to the respective Dumet wires111.

The protective member12protects the thermosensitive body101, the Dumet wires111, and the core wires112A from external force such as impact, and contributes to insulation between the thermosensitive element11and the coil8.

The protective member12is made of a fluorine resin such as polytetrafluoroethylene (PTFE) and tetrafluoroethylene-perfluoroalkylvinylether copolymer (PFA). The protective member12may be made of an appropriate resin material irrespective of a thermoplastic resin and a thermosetting resin, in addition to these resin materials.

When the protective member12is made of a transparent resin, appearance inspection of the thermosensitive element11is performable through the protective member12.

The protective member12according to the present embodiment has a substantially rectangular-parallelepiped outer shape extending in the front-rear direction. As illustrated inFIG.3B, the protective member12has a flat contact surface (10A, seeFIG.3B) that comes into contact with the coil8through a part of the bracket20, and a joined portion12A.

The protective member12can be manufactured by, for example, injection molding while the thermosensitive element11is placed in a mold.

Note that the protective member12may not have a constant thickness. For example, a front end12aside of the protective member12on which a joining portion22is disposed may be smaller in thickness than a part where the joining portion22is not disposed.

As illustrated inFIG.4A, the protective member12is set to a predetermined length extending rearward from the front end12a. Neither the thermosensitive body101nor the electric wires110of the thermosensitive element11are present in the joined portion12A. The joined portion12A is made of a resin material in a solid state.

The joining portion22(described below) of the bracket20is joined to the joined portion12A. Therefore, the joined portion12A is set at a position different from the thermosensitive body101and the electric wires110so as not to destroy the thermosensitive element11when the joining portion22is caulked. The joined portion12A according to the present embodiment corresponds to a portion protruding forward from a bracket main body200in the temperature sensor10.

Note that the joined portion12A is set to a length (dimension in longitudinal direction of temperature sensor10) sufficient to be stably joined to the joining portion22of the bracket20.

The form of the temperature sensor10is not limited to the form described in the present embodiment, and the temperature sensor10may have an appropriate form. For example, the appearance shape of the protective member12is not limited to the rectangular-parallelepiped shape, and may be a cylindrical shape or the like. The thermosensitive element11may be covered with a protective member such as a tube made of an insulating material, in place of the protective member12. At this time, one part and the other part of the thermosensitive element11may be independently covered with different protective members.

Also in this case, the joined portion may be provided at a position other than the positions of the thermosensitive body101and the electric wires110, in the temperature sensor10.

Next, a configuration of the metal bracket20is described with reference toFIG.1toFIGS.3A,3B.

The bracket20is a single member made of a metal material. The bracket20holds the temperature sensor10, and clamps the coil8. The bracket20includes the bracket main body200that clamps the coil8by elastic force and collects heat to the temperature sensor10, and the joining portion22to be joined to the temperature sensor10.

Typically, the metal material used for the bracket20is remarkably higher in thermal conductivity than the other material such as a resin. Therefore, the temperature change of the bracket20rapidly follows the temperature change of the coil8. Heat is transferred to the temperature sensor10not only from the one surface10A (FIG.3B) side facing the coil8but also from the other surfaces (surfaces other than one surface10A) of the temperature sensor10abutting on the bracket20, through the bracket20. In other words, when the heat of the coil8is collected to the temperature sensor10by the bracket20, the temperature sensor10detects the temperature of the coil8without delay from the temperature change of the coil8, which makes it possible to improve responsiveness of temperature detection.

The bracket20may be made of an appropriate metal material that can clamp the coil8by elastic force, for example, an iron alloy, stainless steel, or phosphor bronze. A so-called spring material, for example, spring steel defined in JIS G4801can be used for the bracket20.

The bracket main body200includes a clamping portion21, a heat collection portion23, and a stopper24.

In the first embodiment, the temperature sensor10is disposed between the heat collection portion23and a part of the clamping portion21.

The clamping portion21is described with reference toFIGS.3A and3B. A portion of the bracket main body200that is bent in a substantially U-shape so as to clamp the extending portion8A of the coil8corresponds to the clamping portion21. A space inside the clamping portion21houses the coil8through an opening210.

The clamping portion21includes a first wall211, a second wall212, and a coupling portion213that couples the first wall211and the second wall212. The first wall211and the second wall212are provided to face each other, and clamp the extending portion8A in a thickness direction (clamping direction D1). The coupling portion213couples the first wall211and the second wall212on a side opposite to the opening210.

A dimension of the coupling portion213in the clamping direction D1corresponds to the thickness of the extending portion8A.

Note that the clamping portion21may be configured to clamp the extending portion8A in the height direction D3. The configuration corresponds to a state where the clamping portion21is rotated by 90 degrees relative to the extending portion8A on a paper surface ofFIG.3A.

As illustrated inFIG.3B, when the clamping portion21is in a non-load stage, the second wall212is inclined to the first wall211. A distance between the first wall211and the second wall212at this time is set shorter on the opening210side than on the coupling portion213side.

When the extending portion8A is inserted between the first wall212and the second wall212of the clamping portion21from the opening210, the clamping portion21on the opening210side is forcibly expanded outward and is elastically deformed as illustrated inFIG.3A. The extending portion8A is clamped between the first wall211and the second wall212by the elastic force of the clamping portion21elastically deformed.

At this time, the first wall211contacts with a side surface of the extending portion8A on an outer periphery side, the second wall212contacts with a side surface of the extending portion8A on an inner periphery side, and the extending portion8A is clamped between the first wall211and the second wall212that are substantially in parallel with each other, over the height direction D3.

A dimension in the height direction D3between the coupling portion213and an end part241of the stopper24is preferably set so as to remain a gap S between the coupling portion213and the extending portion8A when the extending portion8A is completely inserted into the inside of the clamping portion21. This makes it possible to surely insert the entire extending portion8A into the inside of the clamping portion21.

The bracket20is preferably provided with the stopper24in order to prevent separation of the coil8from the clamping portion21.

The stopper24communicates with the second wall212, and is formed by bending one end of the second wall212in a V-shape toward the first wall211at a position beyond the coil8on the opening210side. The end part241of the stopper24is located near the opening210and faces the coil8, which regulates separation of the coil8from the clamping portion21.

As illustrated inFIG.5A, when the coil8abuts on an outer inclined surface242of the V-shaped stopper24, the opening210is expanded due to displacement and deformation of the second wall212(see arrow). The extending portion8A of the coil8can be easily inserted into the inside of the clamping portion21through the expanded opening210.

In other words, the stopper24according to the present embodiment also functions as a guide that guides the coil8to be smoothly inserted into the inside of the clamping portion21.

Note that the stopper24is not limited to the stopper24formed at one end of the second wall212as described above. For example, in place of the stopper24, the bracket20may include a stopper25illustrated inFIG.5B. The stopper25includes a coil supporting portion251and a guide portion252. The coil supporting portion251protrudes from the second wall212toward the first wall211in the clamping direction D1and supports the coil8. The guide portion252is inclined outward from a front end of the coil supporting portion251in the clamping direction D1.

The stopper25guides the coil8toward the inside of the clamping portion21by the guide portion252, and prevents separation of the coil8from the clamping portion21by the coil supporting portion251.

The bracket20may include a stopper having the other configuration that prevents separation of the coil8and preferably contributes to smooth insertion of the coil8. The stopper may be provided on the first wall211, or provided on both of the first wall211and the second wall212, depending on the form of the bracket20.

Each of the stoppers24and25is not limited to the shape formed by bending one end of the first wall211or the second wall212. For example, an elastic piece of another member may be attached to the end part of the first wall212or the second wall212as long as the elastic piece can prevent separation of the bracket from the coil.

The heat collection portion23(FIG.1andFIG.3B) protrudes to outside of the clamping portion21that internally clamps the coil8, and is thermally coupled to the temperature sensor10. Since the heat collection portion23is thermally coupled to the temperature sensor10, it is possible to conduct heat from the heat collection portion23to the temperature sensor10, and to collect the heat to the temperature sensor10. The heat collection portion23communicates with the first wall211of the clamping portion21, and supports the temperature sensor10on the outside of the clamping portion21.

As illustrated inFIG.3B, the heat collection portion23is bent along the surface of the temperature sensor10from an end part on the opening210side of the first wall211of the clamping portion21.

The coil8is clamped between the first wall211and the second wall212of the clamping portion21. Further, the temperature sensor10is clamped between the first wall211and the heat collection portion23. More specifically, the temperature sensor10is disposed between the first wall211and a facing portion23A (FIG.3B) of the heat collection portion23facing the first wall211.

The temperature sensor10supported by the heat collection portion23comes into contact with the coil8through the first wall211. The one side surface10A of the temperature sensor10is disposed on the first wall211.

The heat of the coil8is transferred to the temperature sensor10not only from the one surface10A side facing the coil8but also from the heat collection portion23side because of high thermal conductivity of the metal bracket20.

The clamping portion21and the heat collection portion23according to the present embodiment are formed by bending a belt-like plate material having a constant width. Accordingly, the first wall211and the heat collection portion23are both disposed over the same region10R (FIG.4A) of the temperature sensor10, and the temperature sensor10is clamped between the first wall211and the heat collection portion23.

The region10R (hereinafter, thermosensitive region) of the temperature sensor10clamped between the first wall211and the heat collection portion23is adjacent to a rear side of the above-described joined portion12A.

The heat from the coil8is collected to the thermosensitive region10R through the bracket20. The heat collected to the thermosensitive region10R is detected by the thermosensitive body101.

It is sufficient for the thermosensitive region10R to include at least only the thermosensitive body101.

In the inside of the temperature sensor10, the heat is conducted to the thermosensitive body101mainly through the Dumet wires111. In other words, the Dumet wires111highly contribute to heat input to the thermosensitive body101.

Accordingly, the thermosensitive region10R according to the present embodiment extends from a position located anterior to the thermosensitive body101up to joint positions13between the Dumet wires111and the respective core wires112A of the lead wires112in the front-rear direction D2, in consideration of heat conduction by the Dumet wires111. The thermosensitive region10R includes the whole of the thermosensitive body101and the Dumet wires111extending from the thermosensitive body101.

Further, to prevent overheat of the coil8, the rotor, the stator, and the like, a cooling liquid for cooling is supplied to an inside of the motor. In the present embodiment, since the temperature sensor10is covered with the heat collection portion23, it is possible to prevent splash of the cooling liquid from directly adhering to the temperature sensor10while collecting the heat of the coil8to the temperature sensor10through the heat collection portion23.

As illustrated inFIG.3B, the heat collection portion23according to the present embodiment is disposed along three side surfaces other than the one surface10A of the temperature sensor10. Therefore, the temperature sensor10is surrounded around an axis line set along the longitudinal direction (D2) by the heat collection portion23and the first wall211of the bracket main body200.

As a result, the heat can be efficiently collected over the entire circumference of the temperature sensor10by the heat collection portion23and the first wall211. This makes it possible to improve thermal responsiveness of the temperature sensor10to the temperature change of the coil8.

After the temperature sensor10is inserted into the inside of the heat collection portion23from a direction orthogonal to a paper surface ofFIG.3B, the heat collection portion23is deformed by a small deformation amount by bending processing to press the heat collection portion23toward the first wall211. As a result, the temperature sensor10is held in a state of being pressed between the heat collection portion23and the first wall211. The temperature sensor10is pressed against the wall211by the bending processing of the heat collection portion23, and comes into contact with the coil8through the wall211.

Since the wall211is present, the position of the temperature sensor10held by the bracket20is not shifted when the coil8is inserted into the inside of the clamping portion21.

The following effects are achievable by the configuration in which the temperature sensor10is disposed between the heat collection portion23and the wall211of the metal bracket20. Even when dimension accuracy of the outer shape of the temperature sensor10is varied, the heat can be collected to the thermosensitive region10R of the temperature sensor10while pressing the temperature sensor10between the heat collection portion23and the wall211with appropriate pressure, based on high dimension accuracy of the heat collection portion23and the clamping portion21unique to the metal members. Such a configuration is particularly suitable for a case where a soft resin material is used for the protective member12of the temperature sensor10and the dimension is easily varied only by the single temperature sensor10.

When no gap is present between the members conducting heat, the heat is more efficiently conducted from a heat source to the temperature sensor. This is because the heat can be conducted without through air inferior in thermal conductivity.

Accordingly, the temperature sensor10is preferably brought into contact with each of the wall211and the heat collection portion23without a gap. Likewise, the coil8is preferably brought into contact with each of the walls211and212of the clamping portion21without a gap.

In a case where a gap is present between the members, the gap is preferably filled with a resin material higher in thermal conductivity than the air, for example, an epoxy resin that is relatively high in thermal conductivity among resin materials.

Next, a method of assembling the temperature sensor10to the bracket20according to the present invention is described with reference toFIG.3B.

InFIG.3B, the shape of the heat collection portion23before the temperature sensor10is inserted is illustrated by an alternate long and two short dashes line. To facilitate insertion of the temperature sensor10between the heat collection portion23and the first wall211, a clearance C2between an end edge231of the heat collection portion23and the first wall211before the bending processing is set to be larger than a clearance C1(also seeFIG.2B) between the heat collection portion23and the first wall211after the bending processing of the heat collection portion23. After the temperature sensor10is inserted between the heat collection portion23and the first wall211, the pressing force is applied to perform the bending processing of the heat collection portion23so as to eliminate the clearance C2. As a result, the heat collection portion23is displaced by spring back, and the clearance C1is accordingly formed between the end edge231and the first wall211.

In addition to the bending processing of the heat collection portion23, caulking of the joining portion22described below is performed. As a result, the temperature sensor10is surely held by the bracket20so as to prevent the temperature sensor10from coming off from the heat collection portion23even if force is applied to the temperature sensor10in the axis direction.

To efficiently collect the heat from the coil8to the temperature sensor10, the bending processing of the collection portion23can be performed so as not to form the clearance C1between the end edge231of the heat collection portion23and the wall211.

Note that the clearance C2between the end edge231of the heat collection portion23and the first wall211may be widely secured more than the thickness of the temperature sensor10, and the temperature sensor10may be inserted into the inside of the heat collection portion23from the clearance between the end edge231of the heat collection portion23and the wall211. In this case, caulking pieces221and222of the joining portion22are opened at angles wider than angles illustrated by alternate long and two short dashes lines inFIG.3Aso as not to inhibit insertion of the temperature sensor10.

The joining portion22(FIG.1andFIG.3A) is joined to the temperature sensor10by being caulked. The joining portion22is fixed to the temperature sensor10in a state of being plastically deformed by the applied pressing force.

The joining portion22according to the present embodiment includes the caulking pieces221and222that are paired protrusion pieces to be joined to the joined portion12A of the temperature sensor10.

The caulking pieces221and222communicate with the first wall211of the clamping portion21, and are formed by being stamped integrally with the clamping portion21and the heat collection portion23from a metal plate.

Before the caulking, the caulking pieces221and222are opened in a direction in which front ends are separated from each other, for example, as illustrated by the alternate long and two short dashes lines inFIG.3A. When the caulking pieces221and222are pressurized in the clamping direction D1toward a base part220(also seeFIG.4B) of the joining portion22, the caulking pieces221and222are plastically deformed in shapes illustrated by solid lines inFIG.3Aand crush the joined portion12A in the thickness direction.

Note that the direction of the pressing force for caulking is not limited to the clamping direction D1, and the caulking pieces221and222may be pressurized in the other direction as long as the caulking pieces221and222are folded to positions to hold the joined portion12A.

The front ends of the respective caulking pieces221and222according to the present embodiment are disposed at positions separated toward the outer peripheral side from the coil8. This makes it possible to prevent the front ends of the caulking pieces221and222from scratching and damaging the surface of the coil8.

As illustrated inFIG.4B, the caulking pieces221and222are sectioned on the front side of the wall211by notches29that are provided on respective ends of the base part220of the joining portion22in a direction orthogonal to the front-rear direction D2. The caulking pieces221and222are supported in a cantilever manner from the wall211by a connection portion28that is a residual portion of the notches29. Since the caulking pieces221and222protrude from the clamping portion21, the caulking pieces221and222can be easily caulked to the joined portion12A without being inhibited by the clamping portion21.

The caulking pieces221and222according to the present embodiment extend with a width narrower than a length (dimension in front-rear direction D2) of the joined portion12A, from the base part220toward the respective sides of the temperature sensor10. The end edges on both sides in the width direction and the front end part of each of the caulking pieces221and222are pressed against the joined portion12A.

The caulking pieces221and222are joined to the joined portion12A by receiving pressing force larger than the pressing force when the thermosensitive region10R is pressed by the heat collection portion23. Since neither the thermosensitive body101nor the electric wires110are present in the joined portion12A, the thermosensitive body101and the electric wires110are not damaged in caulking of the caulking pieces221and222. In other words, joint by the caulking pieces221and222does not influence reliability of the thermosensitive element11.

After the temperature sensor10is inserted into the inside of the heat collection portion23, the heat collection portion23may be first pressed to temporarily fix the temperature sensor10and the caulking pieces221and222may be then caulked to the joined portion12A, or the caulking pieces221and222may be first caulked to the joined portion12A and the heat collection portion23may be then pressed. The caulking of the caulking pieces221and222and the pressing of the heat collection portion23may be simultaneously performed as a matter of course.

The temperature sensor10can be stably held over the entire length by the joining portion22including the caulking pieces221and222, and the heat collection portion23, and can be surely fixed against harsh vibration of a vehicle.

Typically, after the temperature sensor10is attached to the joining portion22and the heat collection portion23of the bracket20, the bracket20is attached to a predetermined position of the extending portion8A of the coil8.

However, the temperature sensor10may be attached to the joining portion22and the heat collection portion23after the bracket20is attached to the coil8.

Main Effects by Present Embodiment

The bracket20of the temperature detection device1described above is configured in a simple form as one member in which the portions such as the clamping portion21and the joining portion22are continuous, by the stamping and the bending processing using a metal plate material. When the bracket20having the simple form is used, the temperature sensor10can be held by the joining portion22, and the coil8can be clamped inside the clamping portion21. As a result, the temperature sensor10can be easily attached to the coil8.

Since the bracket20has both of the function of clamping the coil8and the function of holding the temperature sensor10, it is sufficient for the temperature detection device1to include only the bracket20to attach the temperature sensor10to the coil8, in addition to the temperature sensor10. Accordingly, the temperature detection device1does not include resin components that are disposed around the coil8and the temperature sensor10in the related art, at all. According to the present embodiment, the number of components can be reduced and the manufacturing cost of the temperature detection device1detecting the temperature of the coil8can be suppressed. The bracket20is easily shaped by press processing, and the temperature sensor10is easily assembled to the bracket20by caulking the joining portion22. Since the joining portion22is caulked to the joined portion12A that is set at the position different from the positions of the thermosensitive body101and the electric wires110, the joining portion22does not damage the thermosensitive element11. As a result, it is possible to easily manufacture the temperature detection device1while securing reliability of the temperature sensor10.

In addition, the metal bracket20also has the function of collecting the heat of the coil8that is a temperature detection target, to the temperature sensor10because of the high thermal conductivity. The responsiveness of the temperature detection by the temperature sensor10can be improved based on the heat collection function.

In addition to the bracket main body200that mainly contributes to the heat collection to the temperature sensor10, the whole of the bracket20including the joining portion22contributes to the heat collection to the temperature sensor10because the bracket20rapidly follows the temperature change of the coil8based on the thermal conductivity of the metal material.

Thus, according to the bracket20of the present embodiment, the temperature of the coil8can be detected with high responsiveness in the thermosensitive region10R to which the heat is collected by the bracket main body200while the bracket20surely holds the temperature sensor10by the joined portion12A that does not damage the thermosensitive element11.

The bracket20according to the present embodiment includes the bracket main body200collecting heat to the temperature sensor10and the joining portion22joined to the temperature sensor10, as different portions separated in the longitudinal direction of the temperature sensor10. Thus, the portions can be formed in the respective forms most appropriate to the heat collection and the holding.

The responsiveness of the temperature detection device1is described with a result of a test for a thermal time constant τ. The thermal time constant τ is a required time until the temperature of the thermosensitive body101is changed to 63.2% of initial temperature difference.

In a comparative example 1 compared with the present embodiment, a metal member such as the bracket20is not provided around the temperature sensor10. In the temperature sensor10according to the comparative example 1, the protective member12covering the thermosensitive element11is exposed.

The temperature sensor according to the comparative example 1 left in a room temperature was pressed against a metal plate heated to 100° C. simulating the coil in use, and the thermal time constant τ was measured. The thermal time constant τ was 90 seconds.

In contrast, the thermal time constant τ measured when the first wall211of the bracket20of the temperature detection device1according to the present embodiment was pressed against a metal plate heated to 100° C. was 20 seconds.

The thermosensitive element11had the same size, and the thermosensitive body101had the length of about 4 mm in both of the comparative example 1 and the present embodiment.

In a comparative example 2, the thermosensitive body101had the length of about 2 mm, and the metal member was not provided as with the comparative example 1. Typically, the responsiveness of the thermosensitive body101can be improved when the thermosensitive body101is designed in a small shape.

As with the comparative example 1, the thermal time constant τ was measured in the comparative example 2. The thermal time constant τ was 23 seconds.

It is found from comparison between the comparative examples 1 and 2 and the present embodiment that the heat collection action by the bracket20largely contributes to improvement of the responsiveness more than the dimensional difference (about 2 mm) of the thermosensitive body between the comparative examples 1 and 2.

The thermal time constants τ in the comparative examples 1 and 2 and the present embodiment are summarized in the following table.

In the above-described embodiment, both of the clamping portion21and the heat collection portion23are disposed over the thermosensitive region10R along the front-rear direction D2; however, both of the clamping portion21and the heat collection portion23are not necessarily disposed over the thermosensitive region10R.

As described above, however, the thermal responsiveness of the temperature sensor10is improved due to heat transfer to the temperature sensor10also from the heat collection portion23side that is a side opposite to the coil8side, as a main factor.

Therefore, at least the heat collection portion23out of the clamping portion21and the heat collection portion23is preferably disposed over the thermosensitive region10R.

The dimension of each of the clamping portion21and the heat collection portion23in the front-rear direction D2can be appropriately determined in consideration of the heat collection to the temperature sensor10, stable holding of the temperature sensor10, and the like.

Unlike the above-described embodiment, a heat collection portion26may be disposed only on two side surfaces10B and10C of the temperature sensor10as illustrated inFIG.6A. Also in this case, the heat collection portion26is thermally coupled to the thermosensitive region10R because the thermosensitive region10R is disposed between the wall211and the heat collection portion26protruding to the outside of the clamping portion21. Accordingly, the heat from the coil8is collected to the temperature sensor10not only from the coil8side but also from the heat collection portion26side.

Further, as illustrated inFIG.6B, a heat collection portion27may be disposed only on the surface10B orthogonal to the surface10A of the temperature sensor10, and the heat collection portion27may be thermally coupled to the thermosensitive region10R. Also in this case, the heat from the coil8is collected to the temperature sensor10not only from the coil8side but also from the heat collection portion27side.

In other words, it is not necessary for the heat collection portion collecting the heat to the temperature sensor10to surround the temperature sensor10around the axis line and to clamp the temperature sensor10between different portions (23and211) of the heat collection portion. So long as the heat collection portion protrudes to outside of the clamping portion21, is disposed along the portion (e.g.,10B and10C) different from the portion (10A) of the temperature sensor10facing the coil8, and is thermally coupled to the temperature sensor10, as with the heat collection portions23,26, and27, the heat collection portion can contribute to the heat collection to the temperature sensor10. Even when the temperature sensor10has a shape different from the shape described in the above-described embodiment, for example, a cylindrical shape, the heat collection portion can contribute to the heat collection to the temperature sensor10as long as the heat collection portion protrudes to outside of the clamping portion21and is thermally coupled to the temperature sensor10.

It is not necessary for the heat collection portion to hold the temperature sensor10. In this case, the temperature sensor10may be held by the bracket main body200by being bonded to the first wall211.

FIGS.7A and7Billustrate a stopper24′ that is different in shape from the stopper24according to the above-described embodiment. The stopper24′ is formed by bending one end side of the second wall212toward the first wall211side and overlapping both sides of a bent portion243. InFIG.7B, the second wall212before bending is illustrated by a solid line. After the coil8is inserted into the inside of the clamping portion21, the second wall212is bent by 180 degrees as illustrated by an alternate long and two short dashes line to form the stopper24′, and the end part241of the stopper24′ can abut on the coil8.

The stopper24′ also can regulate separation of the coil8from the clamping portion21by the end part241facing the coil8.

FIG.8Aillustrates an example in which a joined portion12B is set also at a rear end part of the protective member12of the temperature sensor10.

In the example illustrated inFIG.8A, the lead wires112are drawn out from the protective member12in a direction orthogonal to the front-rear direction D2. Therefore, the lead wires112are not present at the joined portion12B of the protective member12. Caulking pieces223and224supported rearward in a cantilever manner from the heat collection portion23are joined to the joined portion12B. The temperature sensor10may be held only by the caulking pieces223and224and the heat collection portion23. In this case, the caulking pieces221and222are unnecessary, and it is unnecessary to provide the joined portion12A so as to be located anterior to the thermosensitive body101.

FIG.8Billustrates a case where a region for joint cannot be provided on the front end side of the temperature sensor10for reasons of an installation space or manufacture of the temperature detection device1. In this example, the temperature sensor10is held only by a joined portion12C provided on the rear end side of the temperature sensor10and the heat collection portion23. The lead wires112are located at the joined portion12C. The caulking pieces223and224can be joined to the joined portion12C without damaging the lead wires112(in particular, core wires112A) depending on rigidity of the lead wires112. Therefore, the bracket20may be joined to the joined portion12C where the electric wires110are located as illustrated inFIG.8B.

In a case where there is no concern about damage of the thermosensitive body101because of rigidity, the bracket20may be joined to the protective member12at the position of the thermosensitive body101.

FIG.8Cillustrates an example in which the bracket main body200is joined to joined portions12D,12D of the temperature sensor10. In this example, the lead wires112are covered with the bracket main body200. The bracket main body200is caulked to the joined portions12D,12D located outside the respective lead wires112.

FIGS.9A and9Billustrate a temperature detection device2according to a modification relating to joint between the temperature sensor10and the bracket20. In an example illustrated inFIGS.9A and9B, a tab32that serves as a joining portion extending forward from the heat collection portion23is caulked to the joined portion12A of the temperature sensor10. The tab32is provided with a concave part32A corresponding to an unillustrated punch used in caulking.

FIG.10Aillustrates a temperature detection device3according to another modification relating to the joint between the temperature sensor10and the bracket20. As illustrated inFIG.10A, a tab33extending from the heat collection portion23may be caulked to the joined portion12A by a rivet34. The rivet34penetrates through the tab33and the joined portion12A.

FIG.10Billustrates a temperature detection device4according to still another modification also relating to the joint between the temperature sensor10and the bracket20. In this example, an engagement protrusion35connected to the heat collection portion23is inserted into grooves12E provided on respective sides in the height direction D3of the joined portion12A in a state of being elastically deformed in the height direction D3of the joined portion12A. As described above, the bracket20may be joined to the temperature sensor10by engagement of the engagement protrusion35with the joined portion12A by elastic force.

The temperature sensor10and the bracket20may be joined by the other appropriate method.

The above-described first to eighth modifications are also applicable to second to fourth embodiments described below.

As illustrated inFIG.17, the temperature detection device1may be provided as an assembly previously assembled to a coil element80including an extending portion8A′. In this case, the coil element80as the assembly may be assembled to the other portion of the coil8at a recipient.

This is true of a temperature detection device5according to the second embodiment, a temperature detection device6according to the third embodiment, and a temperature detection device7according to the fourth embodiment.

Second Embodiment

Next, the second embodiment of the present invention is described with reference toFIGS.11A,11BandFIGS.12A,12B.

In the following, matters different from the first embodiment are mainly described. Components similar to the components according to the first embodiment are denoted by the same reference numerals.

As illustrated inFIGS.11A and11B, the temperature detection device5according to the second embodiment includes the temperature sensor10and a bracket40that attaches the temperature sensor10to the extending portion8A of the coil8.

The bracket40includes a bracket main body400that clamps the coil8and the temperature sensor10by elastic force, and a joining portion42joined to the temperature sensor10.

The coil8and the temperature sensor10are pressed in the clamping direction D1by the elastic force of the bracket main body400.

As illustrated inFIG.12A, the bracket main body400includes a first wall411, the second wall212, and the coupling portion213.

In the second embodiment, the temperature sensor10is disposed between the first wall411of the bracket main body400and the coil8.

In the second embodiment, the coil8and the temperature sensor10are both disposed inside the bracket main body400. As illustrated inFIGS.12A and12B, the coil8and the temperature sensor10come into direct contact with each other without through a member. Accordingly, the heat is directly conducted from the coil8to the temperature sensor10. This further contributes to improvement of responsiveness.

In the first embodiment, a hole or a notch may be provided in the wall211(FIG.3A), and the surface10A of the temperature sensor10may be brought into direct contact with the coil8through the hole or the notch, as with the second embodiment.

The bracket main body400includes a supporting portion43supporting the temperature sensor10. The supporting portion43is provided on the wall411, and is bent along three side surfaces of the temperature sensor10. As illustrated inFIG.12A, the supporting portion43has a rectangular cross-section corresponding to the outer shape of the temperature sensor10. The temperature sensor10is housed in a groove43A sectioned inside the supporting portion43, from the inside of the bracket main body400. The surface10A of the temperature sensor10exposed from the groove43A comes into contact with the side surface of the coil8inserted into the inside of the bracket main body400from the opening210.

It is not necessary for the bracket main body400to include the supporting portion43as long as the bracket main body400can support the temperature sensor10. For example, even when the wall411of the bracket main body400is formed flat, the temperature sensor10may be bonded to and supported by the wall411.

As illustrated inFIG.11AandFIG.12A, the joining portion42communicates with the wall411, and includes caulking pieces421and422that are paired protrusion pieces supported in a cantilever manner on the front side of the wall411by a connection portion48(FIG.11A). The caulking pieces421and422of the joining portion42are caulked to the joined portion12A of the temperature sensor10.

To facilitate work to caulk the caulking pieces421and422, and to avoid front ends421A and422A (FIG.12B) of the respective caulking pieces421and422from contacting with the coil8, the joined portion12A of the temperature sensor10is made thinner than the joined portion12A according to the first embodiment (FIG.3A). This is to form a space on the coil8side of the joined portion12A.

Also in the present embodiment, the temperature sensor10is surrounded by the bracket main body400clamping the coil8around the axis line, and the bracket40is thermally coupled to the temperature sensor10. Therefore, the heat of the coil8is collected to the temperature sensor10by heat conduction through the bracket40.

According to the present embodiment, since the temperature sensor10disposed in the same space of the bracket main body400in which the coil8is housed comes into direct contact with the coil8, it is possible to further contribute to improvement of the responsiveness of the temperature detection by the temperature sensor10.

Also in the present embodiment, the bracket main body400is preferably disposed over the thermosensitive region10R (FIG.11A) that is set so as to include the thermosensitive body101and the Dumet wires111, in consideration of contribution to the heat conduction to the thermosensitive body101. In the thermosensitive region10R where the temperature sensor10is covered with the bracket main body400, it is possible to prevent splash of the cooling liquid from directly adhering to the temperature sensor10while collecting the heat of the coil8to the temperature sensor10.

It is not necessary that the coil8and the temperature sensor10clamped by the bracket main body400are pressed against each other. For example, the temperature sensor10located on the coupling portion231side and the coil8located on the opening210side may be disposed adjacently to each other inside the bracket main body400.

Third Embodiment

Next, the third embodiment of the present invention is described with reference toFIGS.13A,13BandFIG.14.

In the following, matters different from the first embodiment are mainly described. Components similar to the components according to the first embodiment are denoted by the same reference numerals.

As illustrated inFIGS.13A and13B, the temperature detection device6according to the third embodiment includes the temperature sensor10and a metal bracket50that attaches the temperature sensor10to the extending portion8A of the coil8.

The third embodiment is different from the first embodiment and the second embodiment in that the bracket50is fastened to the coil8by a bolt61and a nut62as fastening members. In the third embodiment, the coil8is not clamped by the bracket50. In the third embodiment, the bracket50holding the temperature sensor10is fastened to the coil8. As a result, the temperature sensor10is attached to the coil8.

The bracket50includes a bracket main body500that is disposed over the thermosensitive region10R of the temperature sensor10and is thermally coupled to the temperature sensor10, the joining portion22joined to the temperature sensor10, and a fastened portion53fastened to the coil8.

The bracket50according to the third embodiment also has a configuration in which components, namely, the bracket main body500, the joining portion22, and the fastened portion53are integrally made of one metal plate, as with the bracket20according to the first embodiment and the bracket40according to the second embodiment.

The bracket main body500includes a heat transfer portion51that transfers heat generated from the coil8to the temperature sensor10, and a heat collection portion52that communicates with the heat transfer portion51and is thermally coupled to the thermosensitive region10R of the temperature sensor10.

As illustrated inFIG.14, the heat transfer portion51is formed in a rectangular plate shape interposed between the one surface10A of the temperature sensor10and one surface8B of the coil8. The heat transfer portion51is disposed over the thermosensitive region10R (FIG.13A) that includes at least the thermosensitive body101of the temperature sensor10.

A rotation regulation piece51A that is bent to the heat transfer portion51and faces another surface8C (FIG.14) of the coil8is connected to one end side of the heat transfer portion51.

The rotation regulation piece51A regulates rotation of the bracket50and the temperature sensor10to the coil8around an axis of the bolt61(FIGS.13A and13B). The rotation regulation piece51A also contributes to heat transfer from the coil8to the temperature sensor10. Further, since the bracket50is positioned to the coil8by the rotation regulation pieces51A, a shaft part611(FIG.13B) of the bolt61can be easily inserted into the fastened portion53and the coil8.

In a case where another means to regulate relative rotation of the coil8and the bracket50is provided, it is sufficient for the bracket main body500to include at least only the heat transfer portion51. For example, a key and a key groove locking the key are provided on the bracket50and the coil8, which makes it possible to regulate the relative rotation of the bracket50and the coil8. Note that, in a form illustrated inFIG.15described below, the rotation regulation piece51A is not provided.

When the coil8side of the heat transfer portion51is defined as “inside” and the temperature sensor10side of the heat transfer portion51is defined as “outside”, the heat collection portion52(FIGS.13A and13B, andFIG.14) protrudes to outside of the heat transfer portion51, and is thermally coupled to the temperature sensor10. When the heat collection portion52is thermally coupled to the temperature sensor10, the heat can be transferred from the heat collection portion52to the temperature sensor10, and collected to the temperature sensor10. The heat collection portion52communicates with the heat transfer portion51, and supports the temperature sensor10outside the heat transfer portion51.

As illustrated inFIG.14, the heat collection portion52is formed by bending the other end side of the heat transfer portion51along the surface of the temperature sensor10. The temperature sensor10is clamped between the heat transfer portion51and the heat collection portion52. More specifically, the temperature sensor10is disposed between the heat transfer portion51and a facing portion52A (FIG.14) of the heat collection portion52facing the heat transfer portion51.

The heat collection portion52according to the present embodiment is configured in a manner similar to the heat collection portion23(FIG.3B) according to the first embodiment. The heat collection portion52may be configured in a manner similar to the heat collection portion26illustrated inFIG.6Aor the heat collection portion27illustrated inFIG.6B.

The heat is transferred to the temperature sensor10not only from the one surface10A (FIG.14) side facing the coil8but also from the other surfaces (surfaces other than the one surface10A) abutting on the bracket50in the temperature sensor10, through the bracket50because of high thermal conductivity of the metal bracket50. In other words, when the heat of the coil8is collected to the temperature sensor10by the bracket50, the temperature sensor10detects the temperature of the coil8without delay from the temperature change of the coil8, which makes it possible to improve responsiveness of temperature detection.

The joining portion22(FIGS.13A and13B) is caulked to and joined to the temperature sensor10on one side in the front-rear direction D2that is a longitudinal direction of the bracket main body500.

The caulking pieces221and222of the joining portion22are formed by stamping integrally with the heat transfer portion51, the heat collection portion52, and the fastened portion53from a metal plate.

The caulking pieces221and222according to the present embodiment are bent to the outside of the coil8, and respective front ends of the caulking pieces221and222are disposed at positions separated outward from the coil8. Alternatively, as with the caulking pieces421and422illustrated inFIGS.11A,11BandFIGS.12A12B, the caulking pieces221and222may be bent toward the inside of the coil8.

The joining portion22is joined to the joined portion12A of the temperature sensor10not provided with the thermosensitive body101and the electric wires110, as with the first embodiment. The joined portion12A protrudes forward from the bracket main body500.

The fastened portion53is fastened to the coil8by the bolt61and the nut62(FIG.13B) attached to the bolt61. The fastened portion53includes a through hole530that communicates with the front side of the joining portion22and penetrates the fastened portion53in a thickness direction.

The fastened portion53according to the present embodiment is located on an extension extending in the front-rear direction D2from the temperature sensor10held by the bracket50.

In the third embodiment, the bracket main body500including the heat transfer portion51and the heat collection portion52, the joining portion22, and the fastened portion53are disposed in order from the rear side to the front side in the front-rear direction D2of the temperature sensor10.

When the shaft part611(FIG.13B) of the bolt61is inserted into the through hole530and a hole8D penetrating through the coil8, and the nut62is fastened to the front end side of the shaft part611, the bracket50and the coil8are fastened between a head part612of the bolt61and the nut62.

The fastened portion53is formed flat along the surface of the linear extending portion8A according to the present embodiment. The fastened portion53and the heat transfer portion51are located on the same plane.

The fastened portion53has an annular shape around the circular through hole530. However, so long as the fastened portion53can be fastened by the bolt61that has the shaft part611inserted into the through hole530, it is not necessary for the fastened portion53to have an annular shape.

The bracket50and the coil8can be fastened by a rivet in place of the bolt61and the nut62.

Effects by Third Embodiment

According to the third embodiment, the bracket50has a simple configuration in which the portions such as the bracket main body500, the joining portion22, and the fastened portion53are continued as one member by stamping and bending processing using a metal plate member. Using the bracket50having the simple configuration makes it possible to hold the temperature sensor10by the joining portion22, and to fasten the fastened portion53to the coil8, thereby easily attaching the temperature sensor10to the coil8. The bracket50can be easily shaped by press processing, and the bracket50can be easily assembled to the temperature sensor10by caulking of the joining portion22. Since the joining portion22is caulked to the joined portion12A that is provided at the position different from the thermosensitive body101and the electric wires110, the thermosensitive element11is not damaged. Accordingly, it is possible to easily manufacture the temperature detection device6while securing reliability of the temperature sensor10.

In addition, the metal bracket50also has the function of collecting the heat of the coil8that is a temperature detection target, to the temperature sensor10because of the high thermal conductivity. The responsiveness of the temperature detection by the temperature sensor10can be improved based on the heat collection function.

In addition to the bracket main body500that mainly contributes to the heat collection to the temperature sensor10, the whole of the bracket50including the joining portion22and the fastened portion53rapidly follows the temperature change of the coil8based on the thermal conductivity of the metal material. This contributes to the heat collection to the temperature sensor10.

Thus, according to the bracket50of the present embodiment, the temperature of the coil8can be detected with high responsiveness in the thermosensitive region10R to which the heat is collected by the bracket main body500while the bracket50surely holds the temperature sensor10by the joined portion12A that does not damage the thermosensitive element11.

The bracket50according to the present embodiment includes the bracket main body500collecting the heat to the temperature sensor10, the joining portion22joined to the temperature sensor10, and the fastened portion53fastened to the coil8, as different portions separated in the longitudinal direction of the temperature sensor10. Thus, the portions can be formed in the respective forms most appropriate to the heat collection, the holding, and the fixing.

The various forms of the joining portion22of the bracket joined to the temperature sensor10, described with reference toFIGS.8A,8B,8CtoFIGS.10A,10Bare also applicable to the third embodiment.

For example, in the third embodiment, in a case where the caulking pieces221and222of the joining portion22are located posterior to the bracket main body500as illustrated inFIG.8B, the fastened portion53may be connected to the front end of the bracket main body500.

Also in the third embodiment, the temperature sensor10is surrounded around the axis line by the heat transfer portion51and the heat collection portion52of the bracket main body500. Therefore, the heat of the coil8is efficiently collected to the temperature sensor10by the heat conduction through the bracket50.

Further, in the thermosensitive region10R where the temperature sensor10is covered with the bracket main body500, it is possible to prevent splash of the cooling liquid from directly adhering to the temperature sensor10while collecting the heat of the coil8to the temperature sensor10.

Modification of Third Embodiment

The position of the fastened portion53is not limited on the extension extending from the temperature sensor10in the front-rear direction D2.

For example, a fastened portion53′ of a bracket main body500′ illustrated inFIG.15protrudes from the heat transfer portion51of the bracket main body500′ toward one side in a direction (height direction D3) orthogonal to the direction (D2) in which the extending portion8A of the coil8extends.

The fastened portion53′ is fastened to the coil8by the bolt61that has a shaft part penetrating through the through hole530and the hole of the coil8, and an unillustrated nut.

Fourth Embodiment

Next, the fourth embodiment of the present invention is described with reference toFIGS.16A,16B.

The temperature detection device7according to the fourth embodiment is configured by adding the fastened portion53according to the third embodiment (FIGS.13A,13BandFIG.14) to the bracket20(FIGS.2A,2B) of the temperature detection device1according to the first embodiment.

In the following, matters different from the first embodiment are mainly described.

A bracket70according to the fourth embodiment includes a bracket main body700that clamps the coil8by elastic force, the joining portion22joined to the temperature sensor10, and the fastened portion53fastened to the coil8.

The bracket main body700includes the clamping portion21that internally clamps the coil8, the heat collection portion23that protrudes to outside of the clamping portion21and is thermally coupled to the temperature sensor10, and the stopper24that regulates separation of the coil8from the clamping portion21.

The fastened portion53is located on the same plane as the first wall211(FIG.16B) of the clamping portion21.

According to the fourth embodiment, it is possible to more firmly fix the temperature sensor10to the coil8as compared with the first embodiment by fastening of the fastened portion53to the coil8in addition to clamping of the coil8by the clamping portion21of the bracket main body700.

In the fourth embodiment, the fastened portion53can be fastened to the coil8by the bolt61and the nut62while the coil8is clamped by the clamping portion21of the bracket main body700. Since the bracket70is positioned to the coil8by the clamping portion21, the shaft part611of the bolt61can be easily inserted into the through hole530of the fastened portion53and the hole8D of the coil8.

Other than the above description, the configurations described in the above-described embodiments can be selected or appropriately modified without departing from the scope of the present invention.

Although not illustrated, the fastened portion53according to the third embodiment can be added to the bracket40(FIGS.11A,11BandFIGS.12A,12B) of the temperature detection device5according to the second embodiment.

The bracket according to the present invention is not limited to any of the forms described above, and may have an appropriate form.

The temperature sensor10is not necessarily provided along the extending portion8A of the coil8. The temperature sensor10may be inclined to or orthogonal to the extending portion8A.

The bracket according to the present invention may be configured by assembling a plurality of members as long as the bracket has a simple configuration as a metal member including the bracket main body and the joining portion.

Further, although not illustrated, each of the temperature detection devices according to the first to fourth embodiments may be wrapped with a resin or the like in order to secure insulation property with surroundings. Such a configuration makes it possible to secure the insulation property, to prevent splash of the cooling liquid from directly adhering to the temperature sensor10, and to improve the heat collection property.

REFERENCE SIGNS LIST