JPH10318851A - Temperature sensor and its manufacturing method - Google Patents

Abstract

(57) [Problem] To provide a high-speed responsive temperature sensor in a temperature sensor. SOLUTION: In a temperature measuring portion of a temperature sensor, a single core constituted by a lead wire 2 longer than a metal tube 1 passed through a metal tube 1 and an insulator 3 insulating the periphery of the lead wire 2 in the metal tube 1. A tube 4 and a single core tube 4 electrically and mechanically joined to the metal tube 1 and constituted by the metal tube 1, and a lead wire electrically and mechanically joined to the metal tube 1 and protruding from the metal tube 1 A metal cap 5 having a tip 2 disposed inside;
A configuration including a film-shaped temperature measuring element 6 attached to the inner wall of the cap 5 and a conductor 7 filled in the cap 5 and electrically connecting the temperature measuring element 6 and the lead wire 2. By doing so, heat is directly conducted to the temperature measuring element 6, so that a temperature sensor realizing high-speed response can be provided.

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

The present invention relates to a temperature sensor and a method for manufacturing the same.

[0002]

2. Description of the Related Art Conventionally, among sensors for detecting various temperatures, a temperature sensor using a thermistor element as a temperature-sensitive element has been proposed, for example, in Japanese Patent Laid-Open No. Hei 6-283310. FIG. 12 shows a schematic sectional view of such a temperature sensor. The temperature sensor element 102 is made of a ceramic sintered body. A noble metal lead wire 101 is provided inside the temperature sensor element 102, and both are integrally formed at the time of manufacturing. The precious metal lead wire 101 is a lead wire 1 for drawing.
03 is connected. A metal housing 10 is provided on the outer periphery of the lead wire 103 for drawing out via an electrical insulator 104.
5 are provided, and these lead wires 10 for pulling out are provided.
3. Electrical insulator 104 and metal housing 105
Constitutes a two-core tube. 106 is a flange,
The metal housing 105 is fixed. Reference numeral 107 denotes an electrical insulator for insulating the lead wire 103 and the flange 106 from each other. The temperature sensor element 102 is covered with a cap 108 made of heat-resistant metal. The temperature is electrically detected as a resistance value of the temperature sensor element 102.

[0003]

It has been examined whether such a temperature sensor can be applied to an exhaust gas temperature sensor for monitoring the efficiency of an exhaust gas purifying catalyst of an automobile from the viewpoint of environmental protection, which has recently attracted attention. In this case, since it is necessary to detect the catalyst efficiency quickly, high-speed response is required. Therefore, a conventional temperature sensor was actually manufactured and the response was measured.

[0004] Here, the responsiveness is obtained as follows based on the definition of the thermal time constant of a general thermistor.

The temperature sensor is adapted to room temperature. Immerse the temperature sensor in an oil bath set at 150 ° C,
Start time measurement at the same time.

When the resistance value of the temperature sensor is 150.degree.
The time until a resistance value of 2%, that is, a resistance value corresponding to 94.8 ° C., is measured.

The time obtained in the above is defined as responsiveness. The resistance value of the temperature sensor corresponding to 94.8 ° C. is 9
The resistance value when the temperature sensor was left in the oil bath set at 4.8 ° C. for a sufficient time was measured and found in advance.

As a result of the above measurements, the response of the conventional temperature sensor was 6.2 seconds (n = 5) on average. This value can be used sufficiently when the vehicle is in a steady state, but it becomes difficult to accurately measure the temperature when the state of the catalyst changes suddenly, for example, immediately after starting.

The reason for the slow response is that the temperature sensor element 10
This is because the cap 108 is provided on the outside of 2. That is, heat is not directly transmitted to the temperature sensor element 102 by the cap 108, and a time is required for warming the air layer between the two, so that responsiveness deteriorates.

In the case of the temperature sensor without the cap 108, the temperature sensor element 102 deteriorated due to the reducing atmosphere caused by the exhaust gas, and could not be used as a temperature sensor.

As described above, the conventional technology has a problem that the response of the temperature sensor is poor.

An object of the present invention is to solve the above-mentioned conventional problems and to provide a high-speed responsive temperature sensor.

[0013]

SUMMARY OF THE INVENTION To achieve the above object, the present invention provides a lead wire which is passed through a metal tube and which is longer than the metal tube and an insulator which insulates the periphery of the lead wire in the metal tube. A configured single-core tube, a metal cap electrically and mechanically joined to the metal tube, and a tip of the lead wire protruding from the metal tube disposed therein, and a lead provided in the cap. A film-shaped temperature sensor attached to one of the tip of the wire or the inner wall of the cap, and a conductive material that is filled in the cap and electrically conducts between the temperature sensor and the cap or the lead wire. And a body.

Thus, a temperature sensor realizing high-speed response can be configured.

[0015]

DESCRIPTION OF THE PREFERRED EMBODIMENTS The invention according to claim 1 of the present invention is constituted by a lead wire which is passed through a metal tube and which is longer than the metal tube, and an insulator which insulates the periphery of the lead wire in the metal tube. A single-core pipe, a metal cap electrically and mechanically joined to the metal pipe, and a metal cap in which the tip of the lead wire protruding from the metal pipe is disposed. A film-shaped temperature measuring element attached to one of the tip and the inner wall of the cap, and a conductor filled in the cap and electrically conducting between the temperature measuring element and the cap or the lead wire. With
Since the temperature measuring element is provided directly on the tip of the lead wire or on the inner wall of the cap, high-speed response can be achieved.

According to a second aspect of the present invention, in a temperature sensor having a film-shaped temperature measuring member provided on an inner wall of a cap, a conductor is filled so as not to be electrically connected to the inner wall of the cap. Since the area of the conductor in contact with the temperature measuring element can be made constant, it has an effect of reducing output variations while maintaining high-speed response of the temperature sensor.

According to a third aspect of the present invention, there is provided a temperature sensor having a film-shaped temperature measuring element provided at the end of a lead wire, wherein the surface of the temperature measuring element is smaller than the area of the temperature measuring element and the tip of the lead wire. The film-shaped conductor provided from above is added, and since the area of the film-shaped conductor in contact with the temperature measuring element can be made constant, the output variation can be reduced while maintaining the high-speed response of the temperature sensor. It has the effect of reducing.

According to a fourth aspect of the present invention, in the temperature sensor having a film-shaped temperature measuring element provided at the end of the lead wire, a film-shaped insulator is added to a portion of the lead wire where the temperature measuring element does not exist. Since the area of the conductor in contact with the temperature measuring element can be made constant, it has an effect of reducing output variations while maintaining high-speed response of the temperature sensor.

According to a fifth aspect of the present invention, the temperature measuring element is formed of platinum or a thermistor, and has an effect that high-speed measurement can be performed up to a high temperature.

According to a sixth aspect of the present invention, the temperature measuring element is constituted by a paste in which an organic material and a temperature measuring element material are mixed, and by using the paste, a film-like high-speed responsive temperature measuring element is used. Can be easily configured.

According to a seventh aspect of the present invention, the temperature sensor is a CVD device.
It is formed by a method or a sputtering method, and has an effect that a high-speed responsive temperature measuring element can be easily configured by forming the temperature measuring element into a thin film configuration.

According to the invention described in claim 8, the conductor is made of a conductive paste filled in the inside of the cap, and the lead wire can be easily connected to the film-like high-speed responsive temperature sensor. Has an action.

According to the ninth aspect of the present invention, the film-shaped conductor is formed of a conductive paste, and the use of the paste has an effect that the film-shaped conductor can be easily formed with a certain area. .

According to a tenth aspect of the present invention, the film-shaped conductor is formed by a CVD method or a sputtering method, and the film-shaped conductor can be easily formed by a fixed area by forming the film-shaped conductor into a thin film. Has an action.

The eleventh aspect of the present invention has a structure in which the conductive paste does not contain a glass component, and has an effect that the glass component can form a conductor that can withstand high temperatures without interrupting the conductivity.

According to a twelfth aspect of the present invention, the film-like insulator is made of an insulating paste in which an organic material and an insulating material are mixed. It has the effect that it can be easily formed.

According to a thirteenth aspect of the present invention, the film-like insulator is formed by a CVD method or a sputtering method, and the film-like insulator can be easily formed by a constant area by forming the film-like insulator into a thin film. Has an action.

According to a fourteenth aspect of the present invention, the lead wire has a bent portion or a helical portion in a part thereof, and the lead wire expands and contracts due to a difference in thermal expansion at a high temperature. The part absorbs and has the effect of preventing the lead wire from breaking.

According to a fifteenth aspect of the present invention, in the temperature sensor having a film-shaped temperature measuring member provided on the inner wall of the cap, a step of forming a film on the measuring region of the inner wall of the cap; Firing the body, filling the cap with a predetermined amount of conductive material, inserting a single core tube into the cap filled with the conductive material and firing, joining the cap and the single core tube A temperature measuring element can be formed directly on the inner wall of the cap, so that a high-speed responsive temperature sensor can be manufactured.

The invention according to claim 16 uses a plate having an outer diameter pipe slightly smaller than the inner diameter of the cap,
The method includes a step of fitting a cap to one end of the pipe and forming a temperature measuring element in a constant measuring area by a CVD method or a sputtering method from the other end. This has the effect that a high-speed responsive temperature sensor having a value can be manufactured.

According to a seventeenth aspect of the present invention, in the temperature sensor having a film-shaped temperature measuring element provided at the tip of a lead wire, a step of forming a temperature measuring element in a measurement region at the tip of the lead wire; Baking the temperature measuring body, filling the inside of the cap with a predetermined amount of a conductor, inserting a single-core tube into the cap filled with the conductor, and firing the same; and And a bonding step. Since the temperature measuring element can be directly formed at the tip of the lead wire, the temperature sensor having a high-speed response can be manufactured.

The invention according to claim 18 is a temperature sensor provided with a film-shaped temperature measuring element at the tip of a lead wire, wherein the step of forming a temperature measuring element in a measurement region at the tip of the lead wire comprises: A step of firing the temperature measuring element, a step of forming a film-shaped conductor from the tip of the lead wire, the area being smaller than the area of the temperature measuring element, and a step of filling a predetermined amount of the conductor inside the cap. A step of inserting a single core tube into the cap filled with the conductor and firing the same, and a step of joining the cap and the single core tube. Since the area of the film-shaped conductor can be kept constant, high precision is achieved. This has the effect that a high-speed responsive temperature sensor having an appropriate resistance value can be manufactured.

[0033] The invention according to claim 19 uses a plate having a hole slightly larger than the diameter of the lead wire, inserts the tip of the lead wire into the hole, and rotates the single-core tube to rotate the tip of the lead wire. CVD in the direction along the surface of the plate
It has a process of forming a temperature measuring element in a constant measurement area by a sputtering method or a sputtering method. Since the temperature measuring element area is constant, it is possible to produce a high-speed response temperature sensor having a high-precision resistance value. Has an action.

According to a twentieth aspect of the present invention, the method has a step of making the thickness of the plate thicker when forming the film-shaped conductor than when forming the temperature measuring body. Has the effect that it can be reduced more accurately and easily than the temperature measuring element area.

According to a twenty-first aspect of the present invention, there is provided a temperature sensor having a film-shaped temperature measuring element provided at a tip of a lead wire, wherein an insulating layer is formed on the entire lead wire, and the insulating layer is fired. Performing, removing the insulating layer for the measurement region at the tip of the lead wire, forming a temperature sensor in the measurement region at the tip of the lead wire, and firing the temperature sensor, A step of filling a predetermined amount of a conductor into the cap, a step of inserting a single core tube into the cap filled with the conductor and firing, and a step of joining the cap and the single core tube. Since the area of the temperature measuring element is constant, a high-speed responsive temperature sensor having a highly accurate resistance value can be manufactured.

Hereinafter, an embodiment of the present invention will be described with reference to FIG.
This will be described with reference to FIG. (Embodiment 1) FIGS. 1 to 3 show an exploded perspective view and a perspective view of a temperature measuring portion of a temperature sensor according to an embodiment of the present invention. FIG. 1 shows an example in which the tip of a lead wire is bent. 2 shows an example in which the tip of the lead wire has a spiral shape, and FIG. 3 shows a partially transparent perspective view of the temperature measuring portion after assembly. Reference numeral 1 denotes a metal tube made of heat-resistant stainless steel having an outer diameter of 3 mm and a thickness of 0.5 mm, and a nichrome lead wire 2 longer than the metal tube 1, that is, a nichrome lead wire 2 protruding from the metal tube 1. An insulator 3 made of alumina powder is interposed between the metal tube 1 and the metal tube 1 so as to insulate them. The metal tube 1, the lead wire 2 and the insulator 3 constitute a single core tube 4.

Reference numeral 5 denotes a 0.3 mm thick nichrome cap which is electrically and mechanically joined to the metal tube 1 by welding. The tip of the lead wire 2 is disposed in the cap 5. The lead wire 2 is partially bent 9 as shown in FIG.
Is provided. On the inner wall of the cap 5, a film-shaped temperature measuring element 6 attached to the entire surface except for a welded portion 8 with the metal tube 1 is arranged. The temperature measuring element 6 was constituted by applying a commercially available platinum paste containing no glass component and mixed with a platinum powder and an organic material to the inner wall of the cap 5. Between the temperature measuring element 6 and the lead wire 2, a conductor 7 made of the same platinum conductive paste as the temperature measuring element 6 is filled in the cap 5 in order to conduct the two. The conductor 7 was filled so that the amount of the conductor 7 was sufficiently adjusted so as not to be in direct electrical connection with the inner wall of the cap 5 but to be in contact only with the temperature measuring element 6 and not to be in contact with the bent portion 9. FIG.
The configuration after the temperature measuring portion shown in FIG. 3 to FIG. 3 was the same as the conventional example shown in FIG. 12 except that the two-core tube was changed to a single-core tube. The temperature was detected electrically as a change in resistance value due to the temperature of the temperature measuring element 6.

Next, a method of manufacturing the temperature measuring portion of the temperature sensor having such a configuration will be described. First, a temperature measuring element 6 made of platinum paste is applied to a measurement area on the inner wall of the cap 5 and dried in a dryer at 150 ° C. for 10 minutes, and then fired at 1200 ° C. for 3 hours. At this time, if a glass component is contained in the temperature measuring element 6, the glass component is melted when fired at a high temperature of 1200 ° C. and affects the characteristics of the temperature measuring element 6, so that the glass component is not included. Platinum paste was used for the temperature sensor 6.

Next, the inside of the cap 5 is filled with a conductor 7 of which the predetermined amount is sufficiently adjusted so as to be in direct contact with the temperature measuring element 6 without direct electrical connection with the inner wall of the cap 5 by a dispenser. Thereafter, the single-core tube 4 is inserted into the cap 5 filled with the conductor 7, and dried in a dryer at 150 ° C. for 10 minutes in a standing state as shown in FIG.
Bake at 0 ° C. for 3 hours. At this time, the platinum conductive paste used for the conductor 7 did not contain a glass component for the same reason as the platinum paste used for the temperature sensor 6. Finally, the cap 5 and the single-core tube 4 are swaged in the circumferential direction, and the welding portion 8 is laser-welded while rotating the single-core tube 4,
The cap 5 and the single core tube 4 are completely joined. This allows
The cap 5 and the single core tube 4 can be electrically and mechanically joined.

A temperature sensor having such a configuration was prototyped, and the response was examined in the same manner as in the conventional example. As a result, the average was 3.1 seconds (n = 5), which was a half of the conventional example. This is because there is no air layer between the temperature measuring element 6 and the cap 5 as in the conventional example, and the temperature change is directly detected by the temperature measuring element 6.
Think to be transmitted to.

FIG. 4 shows the temperature-resistance characteristics. This is a result when the temperature of the temperature measuring portion was raised from room temperature to 900 ° C. and then lowered, and it was found that there was no hysteresis and the output characteristics were extremely good.

As described above, a high-speed response and high-accuracy temperature sensor can be realized.

In the first embodiment, the bent portion 9 is provided in a part of the lead wire 2. When the temperature of the temperature measuring portion of the temperature sensor is increased or decreased, the bent portion 9 is connected to the lead wire 2 made of nichrome. This is to prevent a thermal stress from being generated in the contact portion between the two due to the difference in the thermal expansion coefficient of the platinum-made conductor 7. That is, if there is no bent portion 9, when a thermal cycle is applied to the temperature measuring portion, a tensile or compressive stress is repeatedly applied to a contact portion between the lead wire 2 and the conductor 7, and the contact portion is cracked or peeled. . However, if the bent portion 9 is provided, expansion and contraction due to heat are absorbed by the resiliency of the bent portion 9, so that no load is applied to the contact portion. Therefore, a highly reliable temperature sensor can be configured. Although the bent portion 9 is provided on the lead wire 2 in the first embodiment, the bent portion 9 is formed as shown in FIG.
But it has exactly the same effect.

Further, in the first embodiment, since the temperature measuring element 6 and the conductor 7 are made of platinum paste, the temperature measuring element 6 and the conductor 7 are combined into one and only the conductor 7 is filled in the cap 5. A configuration in which 6 is formed at the same time is also conceivable. However,
When actually making a temperature sensor with such a configuration,
When the conductive material 7 is filled and then dried to evaporate organic components, the paste is irregularly scattered in the cap 5 due to bubbles generated in the paste, and the cap 5 and the conductive material 7 are scattered.
The contact area between the samples varied significantly between the samples. For this reason, the resistance value of the temperature sensor varied greatly. Therefore,
In order to make the contact area between the cap 5 and the conductor 7 uniform, a film-shaped temperature measuring element 6 made of a platinum paste is applied in a constant area. As a result, a temperature sensor having a small variation in resistance value could be configured.

Although the temperature measuring element 6 is made of a platinum paste, it may be a thermistor paste. We actually fabricated a temperature sensor using thermistor paste.

Thermistor paste is a thermometer material having a negative temperature coefficient. A ceramic sintered body composed of a composite oxide of iron, chromium and aluminum is pulverized, and then ethyl cellulose and α-terpineol are mixed at a ratio of 1: 9. It was prepared by mixing and stirring with an organic material. This is Cap 5
The temperature measuring element 6 was formed by applying the composition to the inside. In addition, drying,
The firing conditions were the same as for the platinum paste temperature sensor, and the other configurations and steps were the same.

When the responsiveness of the temperature sensor thus manufactured was evaluated, it showed a high-speed responsiveness equivalent to that of a platinum paste temperature sensor. FIG. 5 shows temperature-resistance characteristics. The measurement conditions are the same as those in FIG. 4, but the output characteristics are represented by a graph of the reciprocal of temperature-logarithm of resistance because of the thermistor temperature detector. FIG. 5 shows that there is no hysteresis and the output characteristics are very good. Further, since the rate of change in resistance value is orders of magnitude higher than that of a platinum paste temperature measuring element, the temperature sensor can be configured at a lower cost without the need for an external amplifier circuit.
Therefore, a high-speed, high-accuracy, and inexpensive temperature sensor can be realized even with a temperature sensor using thermistor paste.

It should be noted that, in addition to the thermistor having a negative temperature coefficient as in the first embodiment, the same output can be obtained with a thermistor having a positive temperature coefficient.

With the above configuration, it has been found that a high-speed response and high-accuracy temperature sensor can be realized and can be applied as an exhaust gas temperature sensor for automobiles.

(Embodiment 2) The temperature sensor according to the second embodiment of the present invention has many parts which are the same as those of the first embodiment in the structure and the steps. Detailed description is omitted. That is, the second embodiment
Is characterized in that the temperature measuring element 6 is formed as a thin film by a CVD method or a sputtering method. Hereinafter, the temperature sensor actually manufactured in this manner will be described.

FIGS. 6A and 6B are schematic perspective views of a method for forming the temperature measuring element 6 only in a certain measurement area inside the cap 5, wherein a shows the state before the cap 5 is attached and b shows the state after the attachment. Reference numeral 12 denotes a stainless steel plate which is arranged in a chamber of a CVD apparatus or a sputtering apparatus. On the plate 12,
A plurality of stainless steel pipes 11 having a fitting outer diameter slightly smaller than the inner diameter of the cap 5 are attached. The height of the portion of the pipe 11 protruding from the plate 12 matches the width of the welded portion 8 in FIG.

In the step of forming the temperature measuring element 6, first, the cap 5 is fitted into the pipe 11 as shown in FIG. Since there are a plurality of pipes 11, a plurality of films can be simultaneously formed by fitting the caps 5 into each of the pipes. Next, CV
Close the chamber of the D apparatus or the sputtering apparatus,
Is heated to 400 ° C. As a result, the temperature of the cap 5 becomes the same. In this state, a thermistor or a platinum temperature measuring element 6 that has been blown off by a CVD method or a sputtering method is introduced from the back surface of the plate 12. As a result, the temperature measuring element 6 is formed inside the cap 5 as shown in FIG. At this time, the film does not adhere to the portion of the inner wall of the cap 5 fitted to the pipe 11, that is, the welded portion 8. The film thickness was adjusted by adjusting the CVD or sputtering time. This time, it was set to about 2 μm.

The construction and method of construction other than those described above are the same as those of the first embodiment. When the responsiveness and the temperature-resistance output characteristics of the temperature sensor having such a configuration were evaluated, the same excellent characteristics as those of the first embodiment were obtained. In addition,
According to this configuration, the temperature measuring element 6 can be formed in a more uniform area and with a uniform film thickness than the temperature measuring element 6 made of the paste of the first embodiment, so that the output variation of the temperature sensor is further suppressed. Was.

With the above configuration, a high-speed response and high-accuracy temperature sensor can be realized.

(Embodiment 3) FIGS. 7 and 8 show a partially cutaway perspective view and an exploded perspective view of a temperature measuring portion of a temperature sensor according to a third embodiment of the present invention, and FIG. FIG. 8 shows an example in which the tip of the lead wire has a spiral shape. Reference numeral 21 denotes a metal tube made of heat-resistant stainless steel having an outer diameter of 3 mm and a thickness of 0.5 mm. The metal tube 21 is longer than the metal tube 21, that is, a nichrome lead wire 22 protruding from the metal tube 21 and a lead wire 22. An insulator 23 made of alumina powder is interposed between the metal tube 21 and the metal tube 21 so as to insulate them. These metal tube 21 and lead wire 2
2 and the insulator 23 constitute a single core tube 24. 2
Numeral 5 is a 0.3 mm thick nichrome cap electrically and mechanically joined to the metal tube 21 by welding.
The distal end of the lead wire 22 is arranged in 5. The lead wire 22 is partially provided with a bent portion 29 as shown in FIG.

At the tip of the lead wire 22, a film-shaped temperature measuring element 26 is formed. The temperature measuring element 26 was formed by applying the thermistor paste described in the first embodiment to the tip of the lead wire 22. The surface of the temperature measuring element 26 is smaller than the area of the temperature measuring element 26 and the first embodiment from the tip of the lead wire 22.
The film-shaped conductor 31 made of a platinum paste containing no glass component as described above is applied and provided. Film-shaped conductor 3
A conductor 27 made of the same platinum paste as the film-like conductor 31 is filled in the cap 25 between the cap 1 and the cap 25 so as to conduct the two. The conductor 27 was filled with the filling amount adjusted sufficiently so as to be in contact only with the film-shaped conductor 31. The configuration after the temperature measuring part shown in FIGS. 7 and 8 was the same as the conventional example shown in FIG. 12 except that the two-core tube was changed to a single-core tube. The temperature was detected electrically as a change in resistance value due to the temperature of the temperature measuring element 26.

Next, a method of manufacturing the temperature measuring portion of the temperature sensor having such a configuration will be described. First, the lead wire 22
7 was applied to the measurement area at the tip of the sample, that is, the area indicated by 26 in FIG. 7, and dried at 150 ° C. for 10 minutes in a drier.
For 3 hours. Next, as indicated by reference numeral 31 in FIG. 7, a platinum paste containing no glass component is applied from the tip of the lead wire 22 smaller than the area of the temperature measuring element 26 to form the film-shaped conductor 31. . The thermistor paste and the platinum paste may be formed by dipping other than coating. The reason why a paste containing no glass component is used is the same as that described in the first embodiment.

On the other hand, the inside of the cap 25 is filled with a conductor 27, which is sufficiently adjusted in a predetermined amount so as to be in contact with only the film-shaped conductor 31, by a dispenser. Thereafter, the single core tube 24 is inserted into the cap 25 filled with the conductor 27,
After drying in a dryer at 150 ° C. for 10 minutes, the conductor 27 was
Bake at 200 ° C. for 3 hours. Finally, the cap 25 and the single core tube 24 are crimped in the circumferential direction, and the welding portion 28 is laser-welded while rotating the single core tube 24 to completely join the cap 25 and the single core tube 24. Thereby, the cap 25
And the single core tube 24 can be electrically and mechanically joined.

As a result of a prototype of a temperature sensor having such a configuration, and examination of the response by the same method as that of the conventional example, a high-speed response equivalent to that of the first embodiment, that is, half of the conventional example was realized. did it. This is because the temperature measuring element 26
It is considered that there is no air layer as in the conventional example between the cap and the cap 25, and the temperature change is directly transmitted to the temperature measuring element. Further, the same temperature-resistance characteristics as those in FIG. 5 were obtained.

As described above, even with this configuration, a high-speed response and high-accuracy temperature sensor can be realized.

In the second embodiment, the bent portion 29 is provided on a part of the lead wire 22 for exactly the same reason as described in the first embodiment. of course,
The bent portion 29 has exactly the same effect in the spiral portion 30 as shown in FIG.

Further, in the second embodiment, the temperature measuring element 26 is made of a thermistor paste, but it may be made of a platinum paste. In this case, the temperature measuring element 26 and the film-shaped conductor 31
Is a platinum paste, so that the film-shaped conductor 31
Is not required, and the sensitivity is lower than that of the thermistor, but there is an advantage that the structure and the process are simplified. When a temperature sensor having such a configuration was actually manufactured, a temperature sensor having high-speed response equivalent to that of the first embodiment and a high-accuracy output shown in FIG. 4 was obtained.

However, since both the temperature measuring element 26 and the conductor 27 are made of platinum paste, the temperature measuring element 2 and the conductor 27 are combined into one and only the conductor 27 is filled in the cap 25.
6 can also be formed at the same time.
Since the resistance value of the temperature sensor greatly fluctuated for the reason described above, the formation of the temperature measuring element 26 was necessary.

With the above configuration, a high-speed response and high-accuracy temperature sensor can be realized, and it has been found that the temperature sensor can be applied as an exhaust gas temperature sensor for automobiles.

(Embodiment 4) The temperature sensor according to the fourth embodiment of the present invention has many structures and steps that are the same as those of the third embodiment. Detailed description is omitted. That is, the fourth embodiment
The feature of is that the temperature measuring element 26 and the film-shaped conductor 31 are formed by CVD.
That is, a thin film is formed by a sputtering method or a sputtering method.
Hereinafter, the temperature sensor actually manufactured in this manner will be described.

FIGS. 9 (a) to 9 (d) show the temperature measuring element 26 and the film-shaped conductor 3 at the tip of the lead wire 22 only in a certain measurement area.
1 (a) is a schematic perspective view of a method for forming a thermometer 26;
(B) is a perspective view after forming the temperature measuring element 26, (c) is a step during forming the film-shaped conductor 31,
(D) shows a perspective view after the film-shaped conductor 31 is formed. Reference numeral 32 denotes a plate (A) made of stainless steel, which is disposed in a chamber of a CVD apparatus or a sputtering apparatus. 33 is a plate (B) made of stainless steel, and C is the same as plate (A) 32.
It is arranged in a chamber of a VD device or a sputtering device. The thickness of the plate (B) 33 is larger than that of the plate (A) 32. Plate (A) 32 and plate (B) 33 have lead wire 2
A hole 34 having a diameter slightly larger than the diameter of the second hole 2 is provided.

The steps for forming the temperature measuring element 26 and the film-shaped conductor 31 are as follows: first, as shown in FIG.
2 is inserted into the hole 34 of the plate (A) 32. In addition, one core tube 2
4 is attached to a rotation mechanism (not shown). Next, the chamber of the CVD apparatus or the sputtering apparatus is closed, and the plate (A) 32 is heated to 400 ° C. This allows
The temperature of the lead wire 22 is also almost the same. In this state, the temperature measuring element 26 of the thermistor, which has been blown off by the CVD method or the sputtering method, is introduced from the direction along the surface of the plate (A) 32. At this time, the single core tube 24 is rotated by a rotating mechanism as shown in FIG.
It is rotated as shown in FIG. As a result, FIG.
As shown in (b), the temperature measuring body 26 is formed in a certain measurement area on the surface of the lead wire 22. The film thickness was adjusted by adjusting the CVD or sputtering time. This time about 2
μm.

Next, as shown in FIG.
2 is inserted into the hole 34 of the plate (B) 33. The single core tube 24 is attached to a rotation mechanism (not shown). Further, C
The chamber of the VD apparatus or the sputtering apparatus is closed, and the plate (B) 33 is heated to 400 ° C. As a result, the temperature of the lead wire 22 becomes almost the same. In this state, platinum is converted to C
What was blown off by VD method or sputtering method
32 is introduced from the direction along the surface. At this time, one core tube 2
Reference numeral 4 is rotated by a rotation mechanism as shown in FIG. As a result, as shown in FIG. 9D, a film-shaped conductor 31 is formed in a certain measurement area on the surface of the temperature measuring element 26. At this time, since the plate (B) 33 is thicker than the plate (A) 32, the area is always smaller than the area of the temperature measuring element 26 and the lead wire 2
The film-shaped conductor 31 can be formed from the front end of the second conductor 2. The film thickness was determined by adjusting the CVD or sputtering time. This time, it was set to about 1 μm.

The construction and construction method other than those described above were the same as those of the third embodiment. When the responsiveness and temperature-resistance output characteristics of the temperature sensor having such a configuration were evaluated, the same excellent characteristics as those of the third embodiment were obtained. In addition,
According to this configuration, the temperature measuring element 26 can be formed in a more uniform area and with a uniform film thickness than the temperature measuring element 26 made of the paste of the third embodiment, so that the output variation of the temperature sensor is further suppressed. Was.

With the above configuration, a high-speed response and high-precision temperature sensor can be realized.

If the temperature measuring element 26 is made of platinum, the latter can be omitted because it is made of the same material as the film-shaped conductor 31. In this case, the sensitivity is lower than that of the thermistor, but since the steps of FIGS. 9C and 9D are not required, the temperature sensor can be realized with a simpler configuration and construction method.

(Embodiment 5) FIGS. 10 and 11 show a partially cut-away perspective view and an exploded perspective view of a temperature measuring portion of a temperature sensor according to a fifth embodiment of the present invention, and FIG. FIG. 11 shows an example in which the tip is bent, and FIG. 11 shows an example in which the tip of the lead wire is spiral. 41 is outer diameter 3mm, thickness 0.5mm
A metal tube made of heat-resistant stainless steel having a length longer than the metal tube 41, that is, a nichrome lead wire 42 protruding from the metal tube 41;
An insulator 43 made of magnesium powder filled between the two is arranged so as to insulate them from each other. The metal tube 41, the lead wire 42, and the insulator 43 constitute a single-core tube 44.
Is configured. Reference numeral 45 denotes a 0.3 mm thick nichrome cap which is electrically and mechanically joined to the metal tube 41 by welding. The tip of the lead wire 42 is disposed in the cap 45. The lead wire 42 has a partly bent portion 49 as shown in FIG.

At the tip of the lead wire 42, a film-shaped temperature measuring element 46 is attached. The temperature measuring element 46 was formed of the thermistor paste described in the first embodiment at the tip of the lead wire 42. A film-like insulator 47 made of an alumina insulating paste containing no glass component is provided on a portion of the surface of the lead wire 42 where the temperature measuring element 46 does not exist. Between the temperature measuring body 46 and the cap 45, a conductor 51 made of a platinum paste containing no glass component is filled in the cap 45 in order to establish conduction between them. The conductor 51 was filled with the filling amount adjusted sufficiently so as to enclose the entire temperature measuring body 46. The configuration after the temperature measuring portion shown in FIG. 10 was the same as the conventional example shown in FIG. 12 except that the two-core tube became a single-core tube.
The temperature was detected electrically as a change in resistance value due to the temperature of the temperature measuring element 46.

Next, a method of manufacturing the temperature measuring portion of the temperature sensor having such a configuration will be described. First, lead wire 42
A film-shaped insulator 47 is formed by dipping the whole in an insulating paste, and dried at 150 ° C. for 10 minutes in a drier, and then fired at 1200 ° C. for 3 hours. Next, the portion of the insulating layer corresponding to the measurement region at the tip of the lead wire 42 is removed by polishing, so that the metal portion of the lead wire 42 is exposed. Thereafter, the temperature measuring element 46 is formed by dipping the tip of the lead wire 42 into the thermistor paste so as to completely cover the exposed area, and dried at 150 ° C. for 10 minutes in a drier. 46 to 12
Bake at 00 ° C for 3 hours. Since the measurement region is determined when the film-shaped insulator 47 is removed, the resistance value of the temperature sensor may vary even if the amount of the thermistor paste covers the measurement region without particularly strict control. There is no.

On the other hand, inside the cap 45, the thermometer 4
A conductor 47 made of a platinum paste that does not contain a predetermined amount of glass component so as to enclose the whole 6 is filled with a dispenser. Note that the paste containing no glass component is used for the same reason as described in the first embodiment. Thereafter, the single core tube 44 is inserted into the cap 45 filled with the conductor 47 and dried in a dryer at 150 ° C. for 10 minutes, and then the conductor 47 is baked at 1200 ° C. for 3 hours. Finally, the cap 45 and the single-core tube 44 are crimped in the circumferential direction, and the welded portion 48 is laser-welded while rotating the single-core tube 44 to completely join the cap 45 and the single-core tube 44. Thereby, the cap 45 and the single core tube 44 can be electrically and mechanically joined.

As a result of producing a temperature sensor having such a configuration and examining the response in the same manner as in the conventional example, a high-speed response equivalent to that of the first embodiment, that is, a half of the conventional example was realized. did it. This is because the temperature measuring element 4
It is considered that there is no air layer between the cap 6 and the cap 45 as in the conventional example, and the temperature change is directly transmitted to the temperature measuring element 46. Further, the same temperature-resistance characteristics as those in FIG. 5 were obtained.

As described above, even with this configuration, a high-speed response and high-accuracy temperature sensor can be realized.

In the fifth embodiment, the bent portion 49 is provided on a part of the lead wire 42 for the same reason as described in the first embodiment. of course,
The bent portion 49 has exactly the same effect in the spiral portion 50 as shown in FIG.

In the fifth embodiment, the temperature measuring element 46 is made of a thermistor paste. However, this may be a platinum paste containing no glass component. In this case, since both the temperature measuring element 46 and the conductor 51 are made of platinum paste, and the temperature measuring element 46 also plays the role of the conductor 51, the structure and the process are simplified although the sensitivity is lower than that of the thermistor. Have. Furthermore, since the measurement region is determined when the film-like insulator 47 is removed, the resistance value of the temperature sensor may not vary even if the amount of platinum paste covers the measurement region without particularly strict control. Absent. Actually, when a temperature sensor having such a configuration was manufactured, a temperature sensor having a high-speed response equivalent to that of the first embodiment and a high-precision output shown in FIG. 4 was obtained.

With the above configuration, a high-speed response and high-accuracy temperature sensor can be realized, and it has been found that the temperature sensor can be applied as an exhaust gas temperature sensor for automobiles.

(Embodiment 6) The temperature sensor according to the sixth embodiment of the present invention has many parts in structure and steps that are the same as those in the fifth embodiment. Detailed description is omitted. That is, the sixth embodiment
The feature is that the temperature measuring element 46 and the film-shaped insulator 47 are formed by CVD.
That is, a thin film is formed by a sputtering method or a sputtering method.
Hereinafter, a method of manufacturing the temperature sensor thus manufactured will be described.

First, the single core tube 44 attached to the rotating mechanism is put in a CVD apparatus or a sputtering apparatus and heated to 400 ° C. In this state, the lead wire 42 obtained by rotating the alumina insulator that was sputtered by CVD or sputtering was rotated.
A film is formed on the entire surface. The film thickness was adjusted by adjusting the CVD or sputtering time. This time, it was set to about 2 μm. Thus, a film-like insulator 47 is formed. Thereafter, the film-shaped insulator 47 is fired at 1200 ° C. for 3 hours.

Next, the metal portion is exposed by polishing the measurement region at the tip of the lead wire 42. The lead wire 42 is again placed in a CVD or sputtering apparatus equipped with a rotating mechanism and heated to 400 ° C., and as shown in FIG. 9A, the temperature measuring element 46 of the thermistor is blown off by a CVD method or a sputtering method. It is introduced from a direction along the surface of the plate (A) 32. At this time, the single core tube 44 is rotated by a rotating mechanism as shown in FIG. As a result, the temperature measuring body 46 is formed in a certain measurement area on the surface of the lead wire 42. The film thickness was adjusted by adjusting the CVD or sputtering time. This time, it was set to about 2 μm. Thereafter, the temperature measuring element 46 is fired at 1200 ° C. for 3 hours.

The construction and method other than those described above were the same as those of the fifth embodiment. When the responsiveness and temperature-resistance output characteristics of the temperature sensor having such a configuration were evaluated, the same excellent characteristics as those of the fifth embodiment were obtained.

With the above arrangement, a high-speed response and high-accuracy temperature sensor can be realized.

If the temperature measuring element 46 is made of platinum, the same material as the conductor 51 is used.
There is no need to form a film by the VD method or the sputtering method. In this case, the sensitivity is lower than that of the thermistor.
Since the step (a) is not required, a temperature sensor can be realized with a simpler configuration and construction method.

Although the temperature sensors described in the first to sixth embodiments have been described as being used for an exhaust gas temperature sensor of an automobile, they can be sufficiently used for other temperature sensors such as those for industrial use and home electric appliances. It is.

[0088]

As is apparent from the above description, according to the present invention, a lead wire which is longer than the metal pipe and passed through the metal pipe and an insulator which insulates the periphery of the lead wire in the metal pipe are provided. A single-core pipe, a metal cap electrically and mechanically joined to the metal pipe, and a metal cap in which the tip of the lead wire protruding from the metal pipe is disposed. A film-shaped temperature measuring element attached to one of the tip and the inner wall of the cap, and a conductor filled in the cap and electrically conducting between the temperature measuring element and the cap or the lead wire. Is provided, the heat is directly conducted to the temperature measuring element, so that an advantageous effect that a temperature sensor realizing high-speed response can be provided can be obtained.

[Brief description of the drawings]

FIG. 1 is an exploded perspective view of a temperature measuring portion of a temperature sensor according to an embodiment of the present invention.

FIG. 2 is a perspective view of another temperature measuring part.

FIG. 3 is an assembled perspective view.

FIG. 4 is a temperature-resistance output characteristic diagram of the temperature sensor according to the embodiment of the present invention;

FIG. 5 is a graph showing a reciprocal of a temperature and a logarithmic output characteristic of a resistance value of the temperature sensor according to the embodiment of the present invention;

FIG. 6 is a schematic perspective view of a method for forming a temperature measuring element of a temperature sensor according to a second embodiment of the present invention.

FIG. 7 is a partially cutaway perspective view of a temperature measuring portion of a temperature sensor according to a third embodiment of the present invention.

FIG. 8 is an exploded perspective view of another example.

FIG. 9 is a schematic perspective view of a method for forming a temperature measuring element and a film-shaped conductor of a temperature sensor according to a fourth embodiment of the present invention.

FIG. 10 is a partially cutaway perspective view of a temperature measuring portion of a temperature sensor according to a fifth embodiment of the present invention.

FIG. 11 is an exploded perspective view of another example.

FIG. 12 is a schematic sectional view of a conventional temperature sensor.

[Explanation of symbols]

 1,21,41 Metal tube 2,22,42 Lead wire 3,23,43 Insulator 4,24,44 Single core tube 5,25,45,108 Cap 6,26,46 Thermometer 7,27,51 Conductor 8, 28, 48 Welded part 9, 29, 49 Bent part 10, 30, 50 Spiral part 11 Pipe 12 Plate 31 Film conductor 32 Plate (A) 33 Plate (B) 34 Hole 47 Film insulation Body 101 Noble metal lead wire 102 Temperature sensor element 103 Lead wire for drawing out 104, 107 Electrical insulator 105 Metal housing 106 Flange

 ────────────────────────────────────────────────── ─── Continuing on the front page (72) Inventor Tsuyoshi Tanaka 1006 Kadoma Kadoma, Kazuma, Osaka Prefecture Inside Matsushita Electric Industrial Co., Ltd.

Claims (21)

[Claims] 1. A lead wire which is longer than the metal tube and passes through the metal tube, a single core tube made of an insulator for insulating the periphery of the lead wire in the metal tube, A metal cap that is mechanically joined and the tip of the lead wire protruding from the metal tube is disposed inside, and is attached to one of the tip of the lead wire and the inner wall of the cap provided in the cap. A temperature sensor comprising: a film-shaped temperature measuring element; and a conductor filled in the cap and electrically conducting between the temperature measuring element and the cap or the lead wire. 2. The temperature sensor according to claim 1, wherein in the temperature sensor in which a film-shaped temperature measuring element is provided on the inner wall of the cap, a conductor is filled so as not to be electrically connected to the inner wall of the cap. 3. A temperature sensor provided with a film-shaped temperature measuring element at the end of a lead wire, wherein a film-shaped conductive element provided on the surface of the temperature measuring element with a smaller area than the area of the temperature measuring element and provided from the end of the lead wire. The temperature sensor according to claim 1, further comprising a body. 4. The temperature sensor according to claim 1, wherein a film-shaped insulator is added to a portion of the lead wire where the temperature-measuring element does not exist. Sensor. 5. The temperature sensor according to claim 1, wherein the temperature sensor is platinum or a thermistor. 6. The temperature sensor according to claim 5, wherein the temperature measuring element is constituted by a paste in which an organic material and a temperature measuring element material are mixed. 7. The temperature sensor according to claim 5, wherein the temperature measuring element is formed by a CVD method or a sputtering method. 8. The temperature sensor according to claim 1, wherein the conductor is made of a conductive paste filled inside the cap. 9. The temperature sensor according to claim 3, wherein the film-shaped conductor is made of a conductive paste. 10. The temperature sensor according to claim 3, wherein the film-shaped conductor is formed by a CVD method or a sputtering method. 11. The temperature sensor according to claim 8, wherein the conductive paste contains no glass component. 12. The temperature sensor according to claim 4, wherein the film-shaped insulator is formed of an insulating paste in which an organic material and an insulating material are mixed. 13. The temperature sensor according to claim 4, wherein the film-shaped insulator is formed by a CVD method or a sputtering method. 14. The temperature sensor according to claim 1, wherein a part of the lead wire has a bent portion or a spiral portion. 15. A temperature sensor in which a film-shaped temperature measuring element is provided on an inner wall of a cap, wherein a step of forming a temperature measuring element in a measurement region of the inner wall of the cap, and a step of firing the temperature measuring element; A temperature sensor including a step of filling a predetermined amount of a conductor inside the cap, a step of inserting and baking a single core tube in the cap filled with the conductor, and a step of joining the cap and the single core tube. Production method. 16. A plate having a pipe having an outer diameter slightly smaller than the inner diameter of a cap, a cap is fitted to one end of the pipe, and a temperature measuring body is formed in a predetermined measurement area from the other end by a CVD method or a sputtering method. 16. The method of claim 15, further comprising:
3. The method for manufacturing a temperature sensor according to claim 1. 17. A temperature sensor provided with a film-shaped temperature measuring element at the tip of a lead wire, wherein a step of forming a temperature measuring element in a measurement region at the tip of the lead wire and a step of firing the temperature measuring element A step of filling a predetermined amount of a conductor in the cap, a step of inserting a single core tube into the cap filled with the conductor and firing, and a step of joining the cap and the single core tube. Manufacturing method of sensor. 18. A temperature sensor provided with a film-shaped temperature measuring element at the tip of a lead wire, wherein a step of forming a temperature measuring element in a measurement region at a tip of the lead wire and a step of firing the temperature measuring element A step of forming a film-shaped conductor from the tip of the lead wire, which is smaller than the area of the temperature measuring element, and a step of filling a predetermined amount of the conductor inside the cap; and filling the conductor. A method for manufacturing a temperature sensor, comprising the steps of: inserting a single core tube into a sealed cap and firing; and joining the cap and the single core tube. 19. Using a plate having a hole slightly larger than the diameter of the lead wire, inserting the tip of the lead wire into the hole, and rotating the single-core tube so that the tip of the lead wire extends along the surface of the plate. 19. The method for manufacturing a temperature sensor according to claim 17, further comprising a step of forming a film of a temperature measuring body in a predetermined measurement region by a CVD method or a sputtering method. 20. The method for manufacturing a temperature sensor according to claim 19, further comprising a step of making the thickness of the plate thicker when forming a film-shaped conductor than when forming a temperature measuring body. 21. A temperature sensor having a film-shaped temperature measuring element provided at the tip of a lead wire, wherein a step of forming an insulating layer over the entirety of the lead wire, a step of firing the insulating layer, Removing the insulating layer from the measurement area at the tip, forming a temperature measuring element on the measurement area at the tip of the lead wire, firing the temperature measuring element, and placing a predetermined amount of conductor inside the cap. A method for manufacturing a temperature sensor, comprising a step of filling, a step of inserting a single core tube into a cap filled with the conductor and firing, and a step of joining the cap and the single core tube.