JP7510893B2 - Temperature Sensor Unit - Google Patents

Description

The present invention relates to a temperature sensor unit that detects the temperature of an object to be measured.

The temperature sensor unit described in Patent Document 1 is known as a temperature sensor unit that measures the temperature of a measurement object such as a conductor. The temperature sensor unit described in Patent Document 1 is equipped with a sensor case having a main body part formed in a bottomed cylindrical shape, and a temperature sensor is inserted inside the main body part while being fixed with resin. By fixing the sensor case to the measured part of the measurement object and bringing the side of the main body part into contact with the surface of the measurement object, the heat of the measured part is transferred to the detection part in the temperature sensor, making it possible for the detection part to detect the temperature of the measurement object.

However, the main body or the surface of the object to be measured may have minute irregularities. In this case, when the side of the main body is brought into contact with the surface of the object to be measured, a gap will be formed at the contact point. When such a gap is formed, it acts as an insulating layer (insulating space), and as a result, the heat of the measured part is blocked by the insulating layer and is difficult to transmit to the detection part. Since the shape of the gap is not necessarily uniform for each object to be measured, not only may the detected temperature vary for each object to be measured depending on the shape of the gap, but it may also be difficult to detect the accurate temperature of the object to be measured.

JP 2020-173113 A

The present invention was made in consideration of the above-mentioned circumstances, and its purpose is to provide a temperature sensor unit capable of measuring the temperature of an object to be measured with high accuracy.

In order to achieve the above object, the temperature sensor unit according to the present invention comprises:
A detection unit;
A first case including the detection unit therein;
a second case that contains at least a part of the first case therein and in which a measured portion of a measurement object is embedded;
A portion of the second case is filled between the measurement target portion and the first case.

In the temperature sensor unit according to the present invention, at least a part of the first case is included inside the second case, and the measured part of the object to be measured is embedded therein. Furthermore, a part of the second case is filled between the measured part and the first case. Therefore, even if the surface of the measured part or the first case is uneven, for example, a part of the second case enters the recess so as to block the recess, and a part of the second case is attached to the surface of the measured part so as to follow the surface shape of the measured part, so that the measured part and the first case can be connected without gaps through a part of the second case. In such a state, a heat insulating layer (heat insulating space) caused by the gap is unlikely to be formed between the measured part and the first case, and even if the shape of the unevenness is different for each measured object, the recess can be well blocked. Therefore, regardless of the shape of the measured object, it is possible to effectively prevent a gap from being formed between the measured part and the first case, and to avoid the problem of individual variation in the detected temperature.

In addition, good thermal coupling is achieved between the measured part and the first case, and heat from the measured part is well transferred to the first case through a part of the second case without being blocked by the insulating layer. This allows the detection unit to detect the accurate temperature of the object to be measured. Furthermore, by connecting the measured part and the first case through a part of the second case, it is possible to sufficiently increase the peel strength (tensile strength) between the first case and the measured part, and it is possible to effectively prevent the first case from peeling off or becoming displaced from the object to be measured. As described above, the temperature sensor unit according to the present invention can realize a temperature sensor unit capable of measuring the temperature of the object to be measured with high accuracy.

Preferably, the measured part and the first case are non-detachably joined to the second case. In this configuration, the measured part and the first case are easily joined integrally to a part of the second case located between the measured part and the first case, and it is possible to join a part of the second case and the measured part without a gap, and it is possible to join a part of the second case and the first case integrally without a gap. Therefore, it is possible to effectively prevent a gap from being formed between the measured part and the first case, and to improve the detection accuracy of the temperature of the measurement object. In addition, by adopting the above-mentioned configuration, it is possible to effectively prevent the measured part from coming off or being displaced from the second case. In addition, as a method for non-detachably joining the measured part and the first case to the second case, for example, a method of integrally molding them by injection molding or the like can be mentioned.

Preferably, the first case and the second case are in close contact with each other. With this configuration, a part of the second case located between the measured part and the first case is integrally joined to the first case, and it is possible to effectively prevent the formation of a gap acting as a heat insulating layer between the measured part and a part of the second case. In addition, by making the part of the second case in close contact with the surface shape of the first case, it is possible to effectively block the recess, and the temperature characteristics of the detection part contained inside the first case can be improved.

Preferably, the first case and the second case are each made of resin, and the main component of the material forming the first case is the same as the main component of the material forming the second case. With this configuration, it is possible to approximate the thermal characteristics (thermal conductivity, linear expansion coefficient, etc.) of the first case and the second case, and the original temperature of the measured part can be detected with high accuracy by the detection part.

Preferably, a first recess is formed on the surface of the part to be measured that faces the first case, extending from one end to the other end in the width direction of the part to be measured. In this configuration, when the part to be measured is embedded in the second case, a part of the second case enters the first recess, and a bridge made of a part of the second case is formed between the part to be measured and the first case. This bridge functions as a retainer for the part to be measured, and therefore can prevent the part to be measured from coming off or shifting out of the second case, particularly in the direction perpendicular to the width direction of the part to be measured.

The above-mentioned temperature sensor unit can be manufactured, for example, by placing the first case and the measured part inside a mold and pouring the material forming the second case therein. With the above-mentioned configuration, the material forming the second case flows in from one end side of the measured part in the width direction through the first recess and flows out from the other end side of the measured part in the width direction. This makes it easy to fill (insert) part of the second case between the measured part and the first case, and makes it easy to prevent the formation of a gap that acts as an insulating layer between the measured part and the first case.

Preferably, the first case abuts against the surface of the object to be measured on one side and the other side of the first recess. With this configuration, the first case is fixed to the object to be measured, and the detection unit contained inside the first case can be well positioned relative to the part to be measured.

Preferably, the detection unit is disposed at a position corresponding to the first recess. As described above, a gap is unlikely to form between the measured part and the first case at the position of the first recess. Therefore, by adopting the above-described configuration, the heat of the measured part can be effectively transferred to the detection unit without being blocked by the insulating layer, and the temperature of the measured part can be accurately detected by the detection unit.

A second recess may be formed on the surface of the first case facing the measured part, extending from one end to the other end in the width direction of the first case. In this case, during the process of embedding the measured part in the second case, the material forming the second case flows in from one end side of the first case in the width direction through the second recess and flows out from the other end side of the first case in the width direction. Therefore, it is possible to easily fill (infiltrate) a part of the second case between the measured part and the first case, and it is easy to prevent a gap acting as a heat insulating layer from being formed between the measured part and the first case. In addition, even with the above-mentioned configuration, a bridge that functions as a retainer is formed by a part of the second case between the measured part and the first case, so that it is possible to prevent the measured part from coming off or being displaced from the second case, especially in the direction perpendicular to the width direction of the measured part.

FIG. 1 is a perspective view showing the configuration of a temperature sensor unit according to a first embodiment of the present invention. FIG. 2 is a perspective view showing an internal configuration of the temperature sensor unit shown in FIG. 3A is a cross-sectional view taken along line IIIA-IIIA of the temperature sensor unit shown in FIG. 2. FIG. 3B is a cross-sectional view taken along line IIIB-IIIB of the temperature sensor unit shown in FIG. 2. FIG. FIG. 4 is a perspective view showing the configuration of a temperature sensor unit according to the second embodiment of the present invention. FIG. 5 is a perspective view showing the internal configuration of the temperature sensor unit shown in FIG. 6A is a cross-sectional view taken along line VIA-VIA of the temperature sensor unit shown in FIG. 6B is a cross-sectional view taken along line VIB-VIB of the temperature sensor unit shown in FIG. 5. FIG. FIG. 7 is a perspective view showing the internal configuration of a temperature sensor unit according to the third embodiment of the present invention. FIG. 8 is a cross-sectional view taken along line VIII-VIII of the temperature sensor unit shown in FIG.

The present invention will now be described with reference to the embodiments shown in the drawings.

First embodiment As shown in Fig. 1, a temperature sensor unit 10 according to a first embodiment of the present invention is for measuring the temperature of a conductor 40, which is an object to be measured, and is used by being attached to, for example, the midpoint (relay wire) of a Y-type connection of a three-phase motor for an automobile, or the midpoint of a Y-type connection of a three-phase coil of a rotating electrical machine. The temperature sensor unit 10 has a temperature sensor 20, an exterior case 30, and a conductor 40. In the temperature sensor unit 10 of this embodiment, the conductor 40 is accommodated inside the temperature sensor unit 10 as a part of the temperature sensor unit 10 during the manufacturing stage, and the conductor 40 is fixed integrally with the temperature sensor 20 to the exterior case 30.

In the drawings shown below, the X-axis corresponds to the longitudinal direction (extension direction) of the conductor 40, the Y-axis corresponds to the lateral direction (width direction) of the conductor 40, and the Z-axis corresponds to the thickness direction of the conductor 40. Hereinafter, the positive side of the Z-axis is referred to as the upper side, and the negative side of the Z-axis is referred to as the lower side.

The temperature sensor 20 is a so-called thermistor type temperature sensor, and as shown in FIG. 2, has a sensor case 21, a detection unit 22, and a lead holding member 23. The temperature sensor 20 may be composed of other types of temperature sensors, such as an NTC (Negative Temperature Coefficient) thermistor, a PTC (Positive Temperature Coefficient) thermistor, a linear resistor, a thermocouple, etc.

The detection unit 22 is disposed inside the sensor case 21 and is covered by the sensor case 21. As shown in Figs. 3A and 3B, the detection unit 22 has a detection element 22a, a covering portion 22b, and a pair of lead wires 22c, 22c. The detection element 22a is an element (thermal element) intended for measuring temperature, and in this embodiment is configured as a thermistor element. The detection element 22a outputs an electrical signal indicating the detected temperature. The detection element 22a is disposed inside the covering portion 22b and is covered by the covering portion 22b.

One end of each of the pair of lead wires 22c, 22c is connected to one side and the other side of the detection element 22a in the Y-axis direction, respectively. The lead wires 22c, 22c are made of a conductive material such as copper, iron, nickel, dumet wire, etc. As shown in FIG. 2, the other end of each of the lead wires 22c, 22c is connected to a pair of wirings 50, 50 inside the sensor case 21 by crimping or the like.

The wiring 50, 50 is made of a conductive material such as PVC wire, polyethylene wire, silicon wire, or fluorine wire. The core of the wiring 50, 50 is made of a conductive material such as copper, iron, or aluminum. The wiring 50, 50 is pulled out to the outside of the sensor case 21 and connected to a circuit or the like (not shown). An electrical signal output from the detection element 22a can be transmitted to a control device or the like (not shown) via the lead wires 22c, 22c and the wiring 50, 50.

As shown in FIG. 3A, covering portion 22b is made of insulating resin or glass, contains detection element 22a inside, and covers detection element 22a. Covering portion 22b is formed in a substantially elliptical sphere shape with its major axis in the X-axis direction, but the shape is not particularly limited and may be a substantially rectangular parallelepiped shape, etc. The distance between covering portion 22b and the bottom surface of sensor case 21 is preferably 0.5 to 1 mm.

The lead holding member 23 is disposed inside the sensor case 21 and is disposed adjacent to the detection unit 22 in the X-axis direction. The lead holding member 23 is for holding the lead wires 22c, 22c connected to the detection element 22a. By holding the lead wires 22c, 22c in the lead holding member 23, it becomes possible to stably pull out the lead wires 22c, 22c along the X-axis direction inside the sensor case 21.

The sensor case (first case) 21 is intended to house (cover) and protect the detection unit 22. In addition to the detection unit 22, the lead holding member 23 and parts of the wiring 50, 50 are housed (embedded) inside the sensor case 21. The sensor case 21 has a generally rectangular parallelepiped shape with its long sides in the X-axis direction. The sensor case 21 is made of resin, and has an inner resin part 21a and an outer resin part 21b. Note that the sensor case 21 may include other resin parts in addition to the inner resin part 21a and the outer resin part 21b.

The outer resin part 21b has a bottomed cylindrical shape and covers the inner resin part 21a from the outside. The outer resin part 21b is made of, for example, a thermoplastic resin, such as PBT (polybutylene terephthalate) or PPS (poly phenylene sulfide). The outer resin part 21b functions as a case for housing the detection part 22 and the inner resin part 21a inside the sensor case 21. An opening is formed at the end of the outer resin part 21b on the negative side of the X-axis, and through this opening, the detection part 22 and the lead holding member 23 can be disposed (inserted) inside the outer resin part 21b, and the resin material forming the inner resin part 21a can be filled inside the outer resin part 21b.

A portion of the tip side of the outer resin part 21b is embedded inside the exterior case 30 and is covered by the exterior case 30. The remaining portion of the outer resin part 21b protrudes from the end face of the exterior case 30 on the negative side of the X-axis and is disposed outside the exterior case 30. A portion of the outer resin part 21b is in close contact with the interior of the exterior case 30 and is non-detachably joined to the exterior case 30.

The inner resin portion 21a is made of, for example, a thermosetting resin, such as epoxy resin. The detection portion 22 and the lead holding member 23 are embedded inside the inner resin portion 21a, and the detection portion 22 and the like can be protected by the inner resin portion 21a.

The conductor 40 is composed of a conductive longitudinal (approximately rectangular) plate-like member, and penetrates the exterior case 30 in the X-axis direction. The conductor 40 functions, for example, as a connection conductor (bus bar) connected to the U-phase, V-phase, or W-phase of a three-phase coil. Alternatively, the conductor 40 itself may function as the U-phase, V-phase, or W-phase of a three-phase coil. The conductor 40 is composed of, for example, a metal material such as copper, a copper alloy, aluminum, or an aluminum alloy.

The conductor 40 has a measured portion 41, a recess 42, a protrusion 43, and contact portions 44a and 44b. In the drawings, the surface of the conductor 40 facing the positive Z-axis direction is called the upper surface, and the surface facing the negative Z-axis direction is called the lower surface. Also, the surface of the sensor case 21 (outer resin portion 21b) facing the positive Z-axis direction is called the upper surface, and the surface facing the negative Z-axis direction is called the lower surface.

The measured part 41 is the part of the conductor 40 to which the temperature sensor 20 (outer resin part 21b) is fixed (the part that is in contact (sensor fixing part)). A part of the measured part 41 is embedded inside the exterior case 30 and is covered by the exterior case 30. This part of the measured part 41 is non-detachably joined to the exterior case 30. The remaining part of the measured part 41 protrudes from the end face of the exterior case 30 on the negative side of the X-axis and is disposed outside the exterior case 30.

The recess 42 is formed in the measured portion 41 and is disposed inside the exterior case 30. A portion of the recess 42 may be exposed to the outside of the exterior case 30. In the illustrated example, the recess 42 is formed only in a portion of the measured portion 41, and the upper surface of the measured portion 41 is flat on both sides of the recess 42 in the X-axis direction. The recess 42 is formed on the surface (upper surface) of the conductor 40 that faces the sensor case 21 of the temperature sensor 20. Hereinafter, the upper surface of the measured portion 41 that faces the sensor case 21 may be referred to as the facing surface 410. Also, the lower surface of the sensor case 21 (outer resin portion 21b) that faces the measured portion 41 may be referred to as the facing surface 210.

As shown in FIG. 2, the recess 42 extends in the Y-axis direction from one end to the other end of the width direction (Y-axis direction) of the measurement target portion 41. The recess 42 has inner wall surfaces (tapered portions 420, 420) only on one side and the other side in the X-axis direction, and no inner wall surfaces are formed on one side and the other side in the Y-axis direction. In other words, the recess 42 is not surrounded by inner wall surfaces over its entire periphery, and a communication path (an open path in which one end and the other end of the conductor 40 in the Y-axis direction are open) is formed along the width direction of the conductor 40, linearly connecting one end and the other end of the conductor 40 in the Y-axis direction. This communication path becomes a passage for the flowing resin during the manufacturing process of the temperature sensor unit 10 described later.

3A, the recess 42 has a predetermined length in the X-axis direction, and the length in the X-axis direction is preferably equal to or less than the length in the X-axis direction of the outer resin portion 21b of the sensor case 21. The length in the X-axis direction of the recess 42 is preferably equal to or less than the length in the X-axis direction of the outer case 30. In the illustrated example, the length in the X-axis direction of the recess 42 is greater than the length in the X-axis direction of the detection portion 22 (covering portion 22b). The length in the X-axis direction of the recess 42 is preferably 1 to 3 times the length in the X-axis direction of the detection portion 22. In this embodiment, the detection portion 22 detects the temperature of the measurement portion 41, particularly at the position of the recess 42. By setting the length in the X-axis direction of the recess 42 within the above range, it becomes possible for the detection portion 22 to accurately detect the temperature of the measurement portion 41 at the position of the recess 42. The temperature of the measurement portion 41 at the position of the recess 42 directly or indirectly indicates the temperature of the conductor 40.

The recess 42 has a predetermined depth in the Z-axis direction. The depth d1 of the recess 42 is preferably 0.1 to 1 mm, and more preferably 0.2 to 0.5 mm. The ratio d1/t1 of the depth d1 of the recess 42 to the thickness t1 of the conductor 40 in the Z-axis direction is preferably 1/8 to 1/2, and more preferably 1/5 to 1/3. The depth d1 of the recess 42 is smaller than the thickness of the detection unit 22 in the Z-axis direction.

The depth d1 of the recess 42 is smaller than the thickness t2 of the outer resin part 21b of the sensor case 21 in the Z-axis direction. The thickness t2 of the outer resin part 21b in the Z-axis direction is preferably 0.3 to 1.2 mm, and more preferably 0.5 to 1 mm. The ratio d1/t2 of the depth d1 of the recess 42 to the thickness t2 of the outer resin part 21b is preferably 1/6 to 5/6, and more preferably 1/4 to 3/4. Note that the thickness t2 is the thickness of the portion of the outer resin part 21b that is positioned opposite the measured part 41.

The recess 42 has a pair of tapered portions 420, 420. One tapered portion 420 is formed at one end of the recess 42 in the X-axis direction, and the other tapered portion 420 is formed at the other end of the recess 42 in the X-axis direction. The tapered portions 420, 420 are formed so that the recess 42 becomes wider as it goes upward. Details will be described later, but a part of the outer case 30 (filling portion 32) is filled between the upper surface of the measured portion 41 and the lower surface of the sensor case 21. By providing the tapered portions 420, 420 in the recess 42, it is possible to sufficiently secure the contact area between the filling portion 32 and the measured portion 41 at the position of the recess 42, and the filling portion 32 and the measured portion 41 are firmly connected, and the conductor 40 can be prevented from falling off the outer case 30.

The detection unit 22 is disposed at a position corresponding to the recess 42 in the X-axis direction. More specifically, the detection unit 22 is disposed so as to be stacked above the recess 42. The detection unit 22 is also disposed in a region between one end and the other end of the recess 42 in the X-axis direction. In the illustrated example, the entire detection unit 22 is disposed in the inner region of the recess 42 in the X-axis direction when viewed from above, but a part of the detection unit 22 may protrude from one end of the recess 42 in the X-axis direction, or a part of the detection unit 22 may protrude from the other end of the recess 42 in the X-axis direction. That is, it is preferable that at least a part of the detection unit 22 (preferably the detection element 22a) is disposed at a position corresponding to (overlapping) the recess 42 in the X-axis direction.

The protrusion 43 is formed on the underside of the measurement target portion 41 and is disposed on the opposite side of the recess 42 in the Z-axis direction. The protrusion 43 protrudes on the opposite side (downward) from the side on which the temperature sensor 20 is disposed, and the length of the protrusion (the height of the protrusion 43) is approximately equal to the depth d1 of the recess 42.

The protrusion 43 has a pair of tapered portions 430, 430. One tapered portion 430 is formed at one end of the protrusion 43 in the X-axis direction, and the other tapered portion 430 is formed at the other end of the protrusion 43 in the X-axis direction. Details will be described later, but the exterior case 30 has an exterior portion 31, and a part of the exterior portion 31 extends below the protrusion 43. By providing the tapered portions 430, 430 on the protrusion 43, it is possible to sufficiently secure the contact area between the exterior portion 31 and the measured portion 41 on the lower side of the conductor 40, and the exterior portion 31 and the measured portion 41 are firmly connected, and the conductor 40 can be prevented from falling off the exterior case 30. Note that the protrusion 43 is not essential and may be omitted.

The contact portion 44a is a portion of the upper surface of the measured portion 41 that contacts the outer resin portion 21b of the sensor case 21 on the positive X-axis side across the recess 42. The contact portion 44a contacts and supports the outer resin portion 21b located at the tip of the sensor case 21. The contact portion 44a is disposed inside the exterior case 30 and is covered by the exterior case 30.

The abutment portion 44b is a portion of the upper surface of the measured portion 41 that abuts against the exterior resin portion 21b of the sensor case 21 on the negative X-axis side across the recess 42. The abutment portion 44b abuts against and supports the exterior resin portion 21b located at the base end (or approximately the center) of the sensor case 21. A portion of the abutment portion 44b is disposed inside the exterior case 30 and is covered by the exterior case 30. The remaining portion of the abutment portion 44b is disposed outside the exterior case 30. The length of the abutment portion 44a in the X-axis direction is smaller than the length of the abutment portion 44b in the X-axis direction.

At the position of the recess 42, the sensor case 21 is simply positioned above the measured part 41, straddling it, and is placed on the upper surface of the measured part 41 at the positions of the abutments 44a and 44b. By placing the sensor case 21 on the abutments 44a and 44b, it is possible to fix (stack) the sensor case 21 in a stable state on the upper surface of the measured part 41. Furthermore, by fixing the sensor case 21 to the upper surface of the measured part 41 in this manner, the detection part 22 contained inside the sensor case 21 can be well positioned with respect to the measured part 41 (particularly the recess 42).

The exterior case (second case) 30 is intended to house (cover) and protect the temperature sensor 20 and the measurement target 41. The exterior case 30 has an exterior section 31 and a filling section 32.

2, the lengths of the exterior part 31 in the Y-axis direction and the Z-axis direction are greater than the lengths of the sensor case 21 in the Y-axis direction and the Z-axis direction, and the exterior part 31 contains at least a portion of the sensor case 21 inside. In the illustrated example, more than half of the area of the sensor case 21 is contained inside the exterior part 31, and the tip of the temperature sensor 20 is disposed inside the exterior part 31. Note that the entire sensor case 21 may be contained inside the exterior case 30. Alternatively, the tip of the temperature sensor 20 may protrude from the end face of the exterior case 30 on the positive side of the X-axis, and the sensor case 21 may penetrate the exterior case 30 along the X-axis direction.

The exterior case 30 is made of a thermoplastic resin such as PBT or PPS, and the main component of the material that forms the exterior case 30 is the same as the main component of the material that forms the outer resin part 21b of the sensor case 21. Therefore, the thermal characteristics (thermal conductivity, linear expansion coefficient, etc.) of the sensor case 21 and the exterior case 30 are similar, and the heat of the measured part 41 shown in FIG. 3A is transferred well to the detection part 22 via the sensor case 21 and the exterior case 30. Therefore, the original temperature of the measured part 41 can be detected with high accuracy in the detection part 22.

The exterior part 31 has a roughly rectangular parallelepiped shape and houses the measured part 41 and a part of the sensor case 21 inside. The exterior part 31 is integrated with the measured part 41 and the sensor case 21, and by covering the measured part 41 and a part of the sensor case 21, it plays a role in maintaining the state in which the sensor case 21 is fixed to the measured part 41. Note that the shape of the exterior part 31 is not limited to the shape shown in the figure, and may be changed as appropriate.

Figure 3B is a cross-sectional view of the temperature sensor unit 10 cut parallel to the YZ plane at the position of the recess 42. As shown in this figure, the exterior part 31 surrounds the measured part 41 and the sensor case 21 in all directions at the position of the recess 42, and no space is formed inside the exterior part 31. The exterior part 31 is roughly divided into a part located above the sensor case 21, a part located below the measured part 41, and a part located on both sides of the sensor case 21 and the measured part 41, and these parts are continuously connected (integrated). As shown in Figure 3A, the exterior part 31 also covers the parts of the conductor 40 other than the measured part 41. Specifically, a part of the conductor 40 located beyond the tip of the sensor case 21 is covered by the exterior part 31.

The filling portion 32 is filled (placed) between the upper surface of the measured portion 41 and the lower surface of the sensor case 20 (outer resin portion 21b) at the position of the recess 42. The filling portion 32 fits inside the recess 42 and has a shape that corresponds to the internal shape of the recess 42. The filling portion 32 is in contact (joined) with the upper surface of the measured portion 41 at the position of the recess 42. At the contact surface between the filling portion 32 and the measured portion 41, the filling portion 42 is attached to the measured portion 41 so as to follow the surface shape of its upper surface.

The filling section 32 is in close contact with the underside of the outer resin section 21b at the position of the recess 42, and is integrated with the outer resin section 21b. In other words, the sensor case 21 and the exterior case 30 are in close contact with each other via the filling section 32, and a fault can be seen at the joint between them. At the joint surface between the filling section 32 and the outer resin section 21b, the filling section 42 is attached to the outer resin section 21b so as to follow the surface shape of its underside.

The height of the filling portion 32 is approximately equal to the depth d1 of the recess 42. In addition, the length of the filling portion 32 along the X-axis direction is approximately equal to the length of the recess 42 along the X-axis direction, and the length of the filling portion 32 along the Y-axis direction is approximately equal to the length of the recess 42 along the Y-axis direction. In addition, the length of the recess 42 along the Y-axis direction is equal to the width of the conductor 40 in the Y-axis direction.

Although details will be described later, the temperature sensor unit 10 can be manufactured, for example, by placing the sensor case 21 and the measured part 41 inside a metal mold (molding die) and pouring the material that forms the exterior case 30 into it. In other words, the exterior case 30 is an insert molded product in which the sensor case 21 and the measured part 41 are inserted parts, or a molded product that encases the sensor case 21 and the measured part 41.

During this manufacturing process (the process in which the measured portion 41 is embedded in the exterior case 30), the recess 42 functions as an escape hole for the fluid resin, and the material forming the exterior case 30 flows into the interior of the recess 42 through one end of the recess 42 in the Y-axis direction, and flows out of the recess 42 through the other end of the recess 42 in the Y-axis direction. This makes it possible to fill (penetrate) the filling portion 32, which is part of the exterior case 30, between the measured portion 41 and the sensor case 21, and prevents the formation of a gap that acts as an insulating layer between the measured portion 41 and the sensor case 21.

As shown in FIG. 3B, the filling section 32 is connected (integrated) to the exterior section 31 on one side and the other side of the measured section 41 in the Y-axis direction. The filling section 32 forms a bridge that extends from one side to the other side of the measured section 41 in the Y-axis direction. This bridge functions to prevent the measured section 41 from coming off the exterior case 30, and the anchor effect makes it possible to prevent the measured section 41 from coming off or becoming displaced from the exterior case 30, particularly in the X-axis direction.

The sensor case 21 is sandwiched in the Z-axis direction between the filling section 32 and the exterior section 31 located above the sensor case 21. The measured section 41 is sandwiched in the Z-axis direction between the filling section 32 and the exterior section 31 located below the measured section 41. At the position of the recess 42, the sensor case 21 and the measured section 41 are not directly connected, but are indirectly connected via the filling section 32.

Next, a method for manufacturing the temperature sensor unit 10 will be described with reference to FIG. 3A etc. First, the temperature sensor 20, the conductor 40, and a mold for molding the exterior case 30 are prepared. The temperature sensor 20 may be one that is commercially available. The mold may be one in which a first mold and a second mold are arranged above and below each other. Next, a part of the temperature sensor 20 and a part of the conductor 40 are arranged above and below inside the mold.

More specifically, the tip of the temperature sensor 20 is placed on the contact portion 44a of the conductor 40, and the base end (approximately the center) is placed on the contact portion 44b of the conductor 40. As a result, the upper part of the recess 42 located between the contact portions 44a and 44b is blocked by the sensor case 21 (outer resin portion 21b), and a space is formed surrounded by the upper surface of the measured portion 41 and the lower surface of the outer resin portion 21b. Inside the space corresponding to this recess 42, a filling portion 32 is formed, as described below. Note that since no members are arranged on either side of the measured portion 41 in the Y-axis direction, openings are formed on both sides of the space in the Y-axis direction.

The mold is then closed, and the resin that will form the exterior case 30 is poured into the cavity formed inside the mold. As a result, part of the sensor case 21 and part of the measured portion 41 of the conductor 40 are covered with the resin, which hardens to form the exterior portion 31. The resin also flows into the space formed between the upper surface of the measured portion 41 and the lower surface of the outer resin portion 21b from an opening on one side in the Y-axis direction, and flows out from an opening on the other side in the Y-axis direction. As a result, the resin fills the space, and as it hardens, the filled portion 32 is formed.

Next, the mold is opened, and the outer case 30 (resin molded body) in which the temperature sensor 20 and the conductor 40 are molded as one unit is removed. By manufacturing the temperature sensor unit 10 by injection molding in this manner, it is possible to form the temperature sensor unit 10 in which the measured portion 41 and the sensor case 21 are non-detachably joined to the outer case 30.

As described above, in the temperature sensor unit 10 according to this embodiment, as shown in FIG. 3A, the filling portion 32 is filled between the measured portion 41 and the sensor case 21 (outer resin portion 21b). Therefore, even if the surface of the measured portion 41 or the outer resin portion 21b is uneven, the filling portion 32 enters the recess so as to block the recess, and the filling portion 32 is attached to the surface of the measured portion 41 so as to follow the surface shape of the measured portion 41, so that the measured portion 41 and the outer resin portion 21b are connected without any gaps via the filling portion 32. In this state, a heat insulating layer (heat insulating space) caused by the gap is unlikely to be formed between the measured portion 41 and the outer resin portion 21b, and even if the shape of the unevenness is different for each conductor 40 to be measured (even if uneven unevenness is formed), the recess can be well blocked. Therefore, regardless of the surface shape of the conductor 40, it is possible to effectively prevent a gap from forming between the measured part 41 and the outer resin part 21b, and to avoid the problem of individual variation in the detected temperature.

In addition, good thermal coupling is achieved between the measured part 41 and the sensor case 21, and the heat of the measured part 41 is well transferred to the sensor case 21 through the filling part 32 without being blocked by the insulating layer. Therefore, the accurate temperature of the conductor 40 can be detected by the detection part 22. In addition, by connecting the measured part 41 and the outer resin part 21b through the filling part 32, it is possible to sufficiently increase the peel strength (tensile strength) between the sensor case 21 and the measured part 41, and it is possible to effectively prevent the sensor case 21 from peeling off or becoming displaced from the measured part 41.

In addition, in this embodiment, the measured portion 41 and the sensor case 21 are non-detachably joined to the exterior case 30. Therefore, the measured portion 41 and the sensor case 21 are easily joined integrally to the filling portion 32 located between the measured portion 41 and the sensor case 21, and it is possible to join the filling portion 32 and the measured portion 41 without any gaps, and it is also possible to join the filling portion 32 and the sensor case 21 integrally without any gaps. Therefore, it is possible to effectively prevent a gap from being formed between the measured portion 41 and the sensor case 21, and to improve the detection accuracy of the temperature of the conductor 40. In addition, by adopting the above-mentioned configuration, it is possible to effectively prevent the measured portion 41 from coming off or being displaced from the exterior case 30.

In addition, in this embodiment, the sensor case 21 and the exterior case 30 are in close contact with each other. Therefore, the filling section 32 located between the measured section 41 and the sensor case 21 is integrally joined with the sensor case 21, effectively preventing the formation of a gap that acts as an insulating layer between the filling section 32 and the measured section 41. In addition, by making the filling section 32 in close contact with the surface shape of the sensor case 21, it is possible to effectively block the recess (a recess that may be formed on the surface of the sensor case 21), and the temperature characteristics of the detection section 22 contained inside the sensor case 21 can be improved.

In addition, in this embodiment, the detection unit 22 is disposed at a position corresponding to the recess 42. Therefore, the heat of the measured part 41 is transferred well to the detection unit 22 without being blocked by the insulating layer, and the temperature of the measured part 41 can be detected with high accuracy by the detection unit 22.

4 according to a second embodiment of the present invention has the same configuration as the temperature sensor unit 10 according to the first embodiment, and exerts the same effects and advantages, except for the following points. In the drawings, the same reference numerals are used to designate the same components as those in the temperature sensor unit 10 according to the first embodiment, and the description thereof will be omitted.

The temperature sensor unit 110 differs from the temperature sensor unit 10 in the first embodiment in that it has an exterior case 130 and a conductor 140. As shown in FIG. 5, the conductor 140 has a shape that is bent to be approximately U-shaped, and has a lower extension portion 145, an upper extension portion 146, and a bent portion 147. The bent portion 147 is an approximately U-shaped portion that connects the lower extension portion 145 and the upper extension portion 146. The lower extension portion 145 has the same shape as the conductor 40 shown in FIG. 2. The upper extension portion 146 has substantially the same shape as the lower extension portion 145 (a symmetrical shape when inverted upside down) and has the same configuration.

The temperature sensor 20 is disposed between the lower extension portion 145 and the upper extension portion 146. The distance between the lower extension portion 145 and the upper extension portion 146 is approximately equal to the height of the sensor case 21 of the temperature sensor 20 in the Z-axis direction. Therefore, when the temperature sensor 20 is fixed inside the conductor 140, the lower and upper surfaces of the sensor case 21 (outer resin portion 21b) abut against the inner surface of the conductor 140.

More specifically, as shown in FIG. 6A, the lower surface of the sensor case 21 abuts and is fixed to the measured portion 41a at the positions of the abutment portions 44a and 44b formed on the measured portion 41a of the lower extension portion 145. The upper surface of the sensor case 21 abuts and is fixed to the measured portion 41b at the positions of the abutment portions 44a and 44b formed on the measured portion 41b of the upper extension portion 146.

In addition, a portion of the lower surface of the sensor case 21 faces a recess 42a formed in the measured portion 41a of the lower extension portion 145, and a portion of the upper surface of the sensor case 21 faces a recess 42b formed in the measured portion 41b of the upper extension portion 146.

As shown in Figures 6A and 6B, the exterior case 130 differs from the exterior case 30 in the first embodiment in that it has two filling sections 32a, 32b. One filling section 32a is disposed between the upper surface of the measured section 41a of the lower extension section 145 and the lower surface of the sensor case 21 (outer resin section 21b), connecting the measured section 41a to the sensor case 21. The other filling section 32b is disposed between the lower surface of the measured section 41b of the upper extension section 146 and the upper surface of the sensor case 21 (outer resin section 21b), connecting the measured section 41b to the sensor case 21.

In this embodiment, the conductor 140 is provided with two measured parts 41a, 41b, which are connected to the upper and lower surfaces of the sensor case 21 via two filling parts 32a, 32b. Therefore, the same effect as in the first embodiment can be obtained in this embodiment. In addition, in this embodiment, in the conductor 140 having a substantially U-shape, the detection part 22 detects not only the temperature of the lower extension part 145 but also the temperature of the upper extension part 146. Therefore, the measurement performance of the temperature of the conductor 140 can be improved compared to the case where the temperature of the conductor 140 is measured based on the detected temperature of only one of the lower extension part 145 and the upper extension part 146.

7 has the same configuration as the temperature sensor unit 110 according to the second embodiment, and exerts the same effects, except for the following points. In the drawings , the same reference numerals are used to designate the same components as those in the temperature sensor unit 110 according to the second embodiment, and the description thereof will be omitted.

The temperature sensor unit 210 differs from the temperature sensor unit 110 in the second embodiment in that it has a conductor 240 and a temperature sensor 220. The conductor 240 differs from the conductor 140 in the second embodiment in that it has a lower extension portion 245 and an upper extension portion 246, and the lower extension portion 245 and the upper extension portion 246 do not have the recesses 42a and 42b shown in FIG. 5, respectively. In other words, the conductor 240 is composed of a substantially U-shaped conductor whose inner and outer surfaces are flat.

The temperature sensor 220 differs from the temperature sensor 20 in the first embodiment in that it has a sensor case 221. As shown in FIG. 8, the sensor case 221 has an outer resin part 221b, and the outer resin part 221b has case recesses 24a and 24b.

The case recesses 24a and 24b are recessed toward the center of the sensor case 221 in the Z-axis direction. The case recess 24a is formed on the lower surface of the outer resin part 221b, and the case recess 24b is formed on the upper surface of the outer resin part 221b. The case recesses 24a and 24b have a shape corresponding to the recesses 42a and 42b (FIG. 6A) in the second embodiment, and the length in the X-axis direction and the depth in the Z-axis direction of the case recesses 24a and 24b are the same as the length in the X-axis direction and the depth in the Z-axis direction of the recesses 42a and 42b. The positional relationship between the case recesses 24a and 24b and the detection unit 22 is also the same as the positional relationship between the recesses 42a and 42b and the detection unit 22. The thickness of the outer resin part 221b is the same as the thickness of the outer resin part 21b in the second embodiment.

The case recesses 24a, 24b have a pair of tapered portions 25, 25. The tapered portions 25, 25 have the same shape and function as the tapered portions 420, 420 in the second embodiment. The outer resin portion 221b has abutment portions 26a, 26b on its upper surface and also has abutment portions 26a, 26b on its lower surface. The abutment portions 26a, 26b formed on the lower surface of the outer resin portion 221b are formed outside the X-axis direction of the recess 24a and abut against the upper surface of the lower extension portion 245. The abutment portions 26a, 26b formed on the upper surface of the outer resin portion 221b are formed outside the X-axis direction of the recess 24b and abut against the lower surface of the upper extension portion 246. The contact portion 26a is formed on the tip side of the outer resin portion 221b, and the contact portion 26b is formed on the base side (or approximately the center) of the outer resin portion 221b.

At the position of the case recess 24a, a filling portion 32a is arranged (filled) between the upper surface of the measured portion 41a and the lower surface of the sensor case 221 (outer resin portion 221b). At the position of the case 24b, a filling portion 32b is arranged (filled) between the lower surface of the measured portion 41b and the upper surface of the sensor case 221 (outer resin portion 221b). Even if the object for forming the recess is changed from the conductor 240 to the sensor case 220 (outer resin portion 221b) as in this embodiment, it is possible to form filling portions 32a and 32b between the measured portions 41a and 41b and the sensor case 221, and the measured portions 41a and 41b are connected to the upper and lower surfaces of the sensor case 221 via the two filling portions 32a and 32b. Therefore, in this embodiment, the same effect as in the second embodiment can be obtained.

In addition, in this embodiment, case recesses 24a and 24b extending from one end to the other end of the sensor case 221 in the Y-axis direction are formed on the opposing surface of the sensor case 221 (outer resin part 221b) facing the measured part 41a. In this case, in the process of embedding the measured parts 41a and 41b in the outer case 130, the material forming the outer case 130 flows in from one end side of the sensor case 221 in the Y-axis direction through the case recesses 24a and 24b and flows out from the other end side of the sensor case 221 in the Y-axis direction. Therefore, it is possible to easily fill (infiltrate) a part of the outer case 130 between the measured parts 41a and 41b and the sensor case 221, and it is easy to prevent the formation of a gap acting as a heat insulating layer between the measured parts 41a and 41b and the sensor case 221. Even with the above configuration, a bridge that functions as a retainer is formed between the measured parts 41a, 41b and the sensor case 221 by a part of the exterior case 130, so that the measured part 41a can be prevented from coming off or being displaced from the exterior case 130, particularly in the X-axis direction of the measured parts 41a, 41b.

The present invention is not limited to the above-described embodiment, and can be modified in various ways within the scope of the present invention.

In the first embodiment, as shown in FIG. 3A, the conductor 40 has one recess 42, but multiple recesses 42 may be arranged adjacent to each other along the X-axis direction. However, the detection unit 22 (preferably the detection element 22a) is preferably arranged at a position corresponding to the recess 42, and is preferably stacked above the recess 42 (preferably the bottom surface of the recess 42). The same applies to the recess 42a formed in the lower extension 145 or the recess 42b formed in the upper extension 146 in the second embodiment. The same applies to the case recesses 24a, 24b formed in the sensor case 221 in the third embodiment.

In the first embodiment, the shapes of the conductor 40, the sensor case 21, and the exterior case 30 are not limited to those shown in the drawings and may be changed as appropriate. The same applies to the second and third embodiments.

The technology shown in the third embodiment may be applied to the first or second embodiment, and the sensor case 21 may be provided with a case recess.

10, 110, 210...Temperature sensor unit 20, 220...Temperature sensor 21, 221...Sensor case 21a...Inner resin portion 21b, 221b...Outer resin portion 210...Facing surface 22...Detection portion 22a...Detection element 22b...Coating portion 22c...Lead wire 23...Lead holding member 24a, 24b...Case recess 25...Tapered portion 26a, 26b...Abutment portion 30 , 130... exterior case 31, 131... exterior portion 32, 32a, 32b... filling portion 40, 140, 240... conductor 41, 41a, 41b... measured portion 410... opposing surface 42, 42a, 42b... recess 420, 430... tapered portion 43... protrusion 44a, 44b... abutment portion 145, 245... lower extension portion 146, 246... upper extension portion 147... bent portion 50... wiring

Claims (11)

A detection unit;
A first case including the detection unit therein;
a second case that contains at least a part of the first case therein and in which a measured portion of a measurement object is embedded;
A portion of the second case is filled between the measurement target portion and the first case ,
A temperature sensor unit in which a first recess is formed on a surface of the measured portion facing the first case, the first recess extending from one end to the other end in a width direction of the measured portion . The temperature sensor unit according to claim 1, wherein the measured part and the first case are non-detachably joined to the second case. The temperature sensor unit according to claim 1 or 2, wherein the first case and the second case are in close contact with each other. the first case and the second case are each formed of a resin,
4. The temperature sensor unit according to claim 1, wherein a main component of a material forming said first case is the same as a main component of a material forming said second case. 5. The temperature sensor unit according to claim 1 , wherein the first case abuts against the surface of the object to be measured on one side and the other side of the first recess. 6. The temperature sensor unit according to claim 1 , wherein the detection portion is disposed at a position corresponding to the first recess. A temperature sensor unit as described in any one of claims 1 to 6 , wherein a second recess is formed on the opposing surface of the first case facing the measured part, the second recess extending from one end to the other end in the width direction of the first case. A detection unit;
A first case including the detection unit therein;
a second case that contains at least a part of the first case therein and in which a measured portion of a measurement object is embedded;
A portion of the second case is filled between the measurement target portion and the first case,
A temperature sensor unit in which a second recess is formed on a surface of the first case facing the measured part, the second recess extending from one end to the other end in a width direction of the first case. The temperature sensor unit according to claim 8 , wherein the measurement target portion and the first case are non-detachably joined to the second case. 10. The temperature sensor unit according to claim 8, wherein the first case and the second case are in close contact with each other. the first case and the second case are each formed of a resin,
11. The temperature sensor unit according to claim 8, wherein a main component of a material forming the first case is the same as a main component of a material forming the second case.

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