JPH11118304A - Mounting structure of thermistor - Google Patents

Abstract

PROBLEM TO BE SOLVED: To always hold a suitable contact state of a thermistor with a heat- sensitive surface of a heat-sensitive tube and eliminate the external air influence on the temp. detection of the thermistor to improve the temp. detecting accuracy of the thermistor. SOLUTION: Springs 31, 32 provided on a mounting member 3 disposed between a heat-sensitive tube 2 and thermistor 1 elastically contact at least two positions separated in the axial direction along one side of a heat-sensitive surface 21 and at least two positions suitably separated in the axial direction of the thermistor 1 to generate specified elastic force between the surface 21 and thermistor 3, always holding suitable relative attitude of the mounting member 3 to the surface 21 enough to surely avoid inclining it carelessly. Thus the thermistor 1 is always pressed and contacted uniformly to the heat-sensitive surface 21 enough to always hold good heat transfer from the surface 21 to the thermistor, thereby operating the thermistor 1 to detect the temp. at a high reliability and high accuracy.

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a mounting structure for a thermistor of a temperature-sensitive cylinder insertion type.

[0002]

2. Description of the Related Art For example, in an air conditioner, it is known to use a temperature-sensitive cylinder-inserted thermistor as one of means for detecting the temperature of a refrigerant circulating in a refrigerant circuit. That is, as shown in FIG. 3, the flanged bottomed cylindrical temperature-sensitive cylinder 52 is disposed in a state of penetrating the wall of the refrigerant pipe 56 and facing the inside thereof (that is, within the temperature environment to be measured). At the same time, from the opening end 52c of the temperature-sensitive cylinder 52 facing the outside to the inside thereof,
The thermistor 51 is inserted and arranged via the mounting member 53, and the temperature of the temperature-sensitive surface 55 of the temperature-sensitive cylinder 52 is detected by the temperature-sensitive portion 51a on the tip side of the thermistor 51.

In this case, in order for the thermistor 51 to accurately detect the refrigerant temperature in the refrigerant pipe 56 via the temperature sensing tube 52, heat transfer from the temperature sensing tube 52 to the thermistor 51 is required. Is done well,
It is necessary to bring the thermistor 51 into pressure contact with the temperature sensing surface 55 of the temperature sensing cylinder 52. Therefore, the mounting member 53
Is configured to have not only a holding function for preventing the thermistor 51 from dropping out of the temperature sensing cylinder 52 but also an urging function for urging the thermistor 51 against the temperature sensing surface 55. .

[0004] That is, the mounting member 53 is formed by bending a leaf spring body having appropriate elasticity. One end of the mounting member 53 is provided with a holding portion 53a for holding the thermistor 51. At the end, a locking portion 53f that is locked to the flange portion 52b of the temperature-sensitive cylinder 52 is provided. Further, a front end side holding portion 53b for holding a corner portion on the front end side of the thermistor 51 by appropriately bending the holding portion 53a and the locking portion 53f in the thickness direction thereof, "F" is located between the base-side holding portion 53e for holding the base-side corner and the front-side holding portion 53b and the base-side holding portion 53e.
And a spring portion 53c bent in a letter shape.

When the thermistor 51 is inserted into the temperature-sensitive cylinder 52, first, the distal end holding portion 53b, the base end holding portion 53e, and the holding portion 53a of the mounting member 53 are inserted into the three members. Set the thermistor 51 in between,
In this set state, the thermistor 51 is inserted into the temperature-sensitive cylinder 52 together with the mounting member 53, and the locking portion 53f of the mounting member 53 is locked to the flange 52b of the temperature-sensitive cylinder 52. Hold.

When the fitting is completed, the top 53d of the spring portion 53c of the mounting member 53 is connected to the temperature sensing surface 55.
The thermistor 51 is pressed against the inner surface on the other side of the temperature-sensitive surface 55 by the elastic restoring force of the spring portion 53c, whereby the thermistor 51 is pressed from the temperature-sensitive cylinder 52 side. The heat transfer to the side is promoted. In FIG. 3, reference numeral 54 denotes a lead wire extending from the outer end of the thermistor 51.

[0007]

According to the conventional thermistor mounting structure, as described above, the thermistor 51 is mounted.
Are held at two front and rear positions of the distal end side holding portion 53b and the proximal end side holding portion 53e of the mounting member 53,
The relative position between the thermistor 51 and the mounting member 53 is always properly maintained. However, the relative position between the mounting member 53 and the temperature-sensitive cylinder 52 is such that the mounting member 53 is in contact with the temperature-sensitive surface 55 at one point of the top 53d of the spring portion 53c. The contact position of the 53d with the temperature sensing surface 55 is an appropriate position (that is, the thermistor 5).
1 is shifted from the position where the entire area in the axial direction can be brought into contact with the temperature-sensitive surface 55) in the axial direction of the temperature-sensitive cylinder 52. Then, the thermistor 51 appears as an inclination of the thermistor 51, and the thermistor 51 rises above the temperature-sensitive surface 55 as shown by a chain line in FIG. There is a concern that the heat transfer to the side will be impeded and the temperature detection accuracy will deteriorate.

In the conventional thermistor mounting structure, the open end 52c of the temperature sensing tube 52 remains open even after the thermistor 51 is mounted. The thermistor 51 is exposed to the outside air entering the inside of the device, and there is a problem that the thermistor 51 is affected by the outside air and the reliability of temperature detection is impaired.

In view of the above, the invention of the present application is to maintain the contact state between the thermistor and the temperature sensing surface of the temperature sensing tube always properly and eliminate the influence of the outside air on the temperature detection of the thermistor, so that the temperature of the thermistor can be detected. The purpose of the present invention is to propose a thermistor mounting structure that improves the detection accuracy.

[0010]

Means for Solving the Problems In the present invention, the following configuration is adopted as specific means for solving such problems.

In the first aspect of the present invention, the thermosensitive surface 21 having a bottomed cylindrical shape and constituted by the outer peripheral wall thereof is exposed to the environment to be measured and its open end 2c is exposed to the outside. A thermistor mounting structure in which the thermistor 1 is inserted and arranged inside the temperature-sensitive cylinder 2 mounted in a state, and the thermistor 1 is mounted in a state of being urged against the temperature-sensitive surface 21 via the mounting member 3. In a state where the mounting member 3 is mounted between the temperature-sensitive cylinder 2 and the thermistor 1, at least two positions on one side in the circumferential direction of the temperature-sensitive surface 21 and in the axial direction thereof are appropriately separated from each other. Springs 31 and 32 for generating a predetermined urging force between the temperature-sensitive surface 21 and the thermistor 1 by elastically contacting at least two positions appropriately separated in the axial direction of the thermistor 1; Energizing It is characterized in that the thermistor 1 was composed as to the circumferential direction of the repression bias to the other side of said temperature sensitive surface 21 by.

According to a second aspect of the present invention, in the thermistor mounting structure according to the first aspect, the opening end 2c of the thermosensitive cylinder 2 is covered with a lid 34 when the thermistor 1 is mounted. It is characterized by.

A third invention of the present application is characterized in that, in the thermistor mounting structure according to the second invention, the lid 34 is formed integrally with the mounting member 3.

[0014]

According to the present invention, the following effects can be obtained by adopting such a configuration.

According to the thermistor mounting structure according to the first invention of the present application, when the mounting member 3 is mounted between the temperature-sensitive cylinder 2 and the thermistor 1, the circumferential direction of the temperature-sensitive surface 21 is changed. A predetermined pressure between the temperature sensing surface 21 and the thermistor 1 by resiliently contacting at least two positions on one side of the thermistor 1 and at least two positions appropriately separated in the axial direction of the thermistor 1. Since the springs 31 and 32 for generating the urging force are provided, when the thermistor 1 is inserted into the temperature-sensitive cylinder 2 via the attachment member 3, the attachment member 3
The springs 31 and 32 provided on the thermosensitive surface 21
The elastic member is in elastic contact with at least two positions appropriately spaced apart in the axial direction with respect to one side in the circumferential direction, whereby the relative posture of the mounting member 3 with respect to the temperature-sensitive surface 21 is always properly maintained. Even if the mounting member 3 is displaced in the axial direction with respect to the temperature-sensitive cylinder 2, the mounting member 3
Is prevented from inadvertently tilting in the temperature-sensitive cylinder 2.

Therefore, the thermistor 1 has at least two positions which are appropriately separated in the axial direction, and the mounting member 3 is always held in a proper posture in the mounting member 3.
Is urged toward the temperature sensing surface 21 side by the urging forces of the springs 31 and 32, so that the entire area of the thermistor 1 in its axial direction is constantly uniformly pressed against the temperature sensing surface 21. As a result, the heat transfer from the temperature-sensitive surface 21 to the thermistor 1 is always maintained satisfactorily, and the temperature detection in the thermistor 1 is performed with high reliability and with high accuracy.

In the second invention of the present application, the following specific effects can be obtained in addition to the effects described above. That is, in the present invention, the opening end 2c of the temperature sensing cylinder 2 is provided.
Is covered by the lid 34 when the thermistor 1 is mounted, so that invasion of outside air into the temperature-sensitive cylinder 2 is prevented as much as possible. The influence of the outside air on the temperature detection of the inserted thermistor 1 is prevented as much as possible, and the accuracy of the temperature detection by the thermistor 1 and the reliability of the detected value are improved accordingly.

In the third invention of the present application, the following specific effects can be obtained in addition to the effects described above. That is, in the present invention, since the lid 34 is formed integrally with the mounting member 3, when the thermistor 1 is inserted into the thermosensitive cylinder 2 via the mounting member 3, The mounting of the lid 34 is performed, and compared with the case where each of these mounting operations is necessary, such as a configuration in which the mounting member 3 and the lid 34 are formed separately, the thermistor mounting operation is performed. It is possible to simplify and to reduce the cost by reducing the number of members.

[0019]

DESCRIPTION OF THE PREFERRED EMBODIMENTS Hereinafter, the present invention will be specifically described based on preferred embodiments. FIG. 1 shows a thermistor 1 mounted by applying the thermistor mounting structure according to the present invention. The thermistor 1 is used, for example, for detecting the temperature of a refrigerant circulating in a refrigerant circuit in an air conditioner, has a round-shape external form, and has, for example, a metal oxide A temperature sensing portion made of a system semiconductor is provided, and a lead wire 4 is drawn out from the base end side. The thermistor 1 is mounted on the refrigerant pipe 5 via a temperature-sensitive cylinder 2 and a mounting member 3 described below.

The temperature-sensitive cylinder 2 is formed in a bottomed cylindrical shape having a flange 2b made of a good conductive material such as copper, for example. The tip has a hemispherical shape. The temperature-sensitive cylinder 2 penetrates through the pipe wall of the refrigerant pipe 5 from the front end side with the opening end 2c on the side of the flange portion 2b facing outward, that is, inside (ie, the temperature environment to be measured). And attached to the refrigerant pipe 5. Therefore, the temperature-sensitive surface 2 of the temperature-sensitive cylinder 2
1 is always in contact with the refrigerant circulating in the refrigerant pipe 5 and is made to have a temperature as equal as possible to the temperature of the refrigerant by the heat transfer from the refrigerant. By detecting, the refrigerant temperature is indirectly detected.

The mounting member 3 is integrally formed of a resin material having an appropriate elasticity. As shown in FIGS. 1 and 2, an extending rod portion 30 extending in a substantially straight plate shape in the axial direction is provided.
A flat end plate 35 that is continuous with one end of the extending rod portion 30 and extends in a direction substantially orthogonal to the one end portion, and is formed continuously with the other end of the extending rod portion 30. It comprises an arc plate-shaped holding portion 33 and a lid 34 which is a disk body continuous with an end of the holding portion 33 and extending in a direction orthogonal to the axial direction. The thermistor 1 is disposed at a portion surrounded by the extending rod portion 30 and the holding portion 33 and the end face plate 35 located at both ends thereof.

The extending rod portion 30 is substantially opposed to one side in the circumferential direction of the thermistor 1 over substantially the entire length thereof, and is located at two positions in the axial direction of the extending rod portion 30. Are formed integrally with a first spring 31 and a second spring 32, respectively. Each of these springs 31 and 32 is a spring having a substantially “F” -shaped appearance in which a substantially central portion in the longitudinal direction is bent into a mountain shape. One plate portions 31a, 32a and the first plate portions 31a, 32a
Second plate portions 31b and 32 which are continuously swingable at the tip of
b, and the first plate portions 31a, 32a
Between the first and second plate portions 31b, 32b are the top portions 31c, 3
2c.

The cover 34 is provided with the thermistor 1.
The groove 34 is provided at the left and right sides of the groove 34 and serves as an outlet for the lead wire 4.
Locking claws 36, 36 are provided to extend to the back side of the.

The procedure for inserting and placing the thermistor 1 inside the thermosensitive cylinder 2 using the mounting member 3 is as follows. That is, the extending rod portion 3 of the mounting member 3
0 and the holding portion 33 and the end face plate 3 located at both ends thereof.
5, the thermistor 1 is fitted and arranged in a portion surrounded by the three members.
Pull out outside from 7. In this state, the thermistor 1 is inserted into the thermosensitive cylinder 2 together with the mounting member 3 from the opening end 2c side, and the locking claw 3 of the lid 34 is inserted.
6 and 36 are engaged with the flange 2b of the temperature-sensitive cylinder 2, respectively. This completes the attachment of the thermistor 1 to the temperature-sensitive cylinder 2 (the state shown in FIG. 1).

When the thermistor 1 is completely mounted, the springs 31 and 32 of the mounting member 3 have their tops 31c and 32c elastically contacting the inner surface of the temperature-sensitive surface 21 of the temperature-sensitive cylinder 2 and The respective second plate portions 31b, 32b
Are in elastic contact with the outer periphery of the thermistor 1 on the distal end side and the outer periphery of the base end side, respectively. The thermistor 1 is pressed and urged against the temperature-sensitive surface 21 of the temperature-sensitive cylinder 2 by the urging force to come into contact with the temperature-sensitive surface 21.

In this case, the mounting member 3 is provided with a top portion 31c, 3 of each of the springs 31, 32 provided on the extending rod portion 30.
The elastic rod 2c makes elastic contact with the temperature-sensitive surface 21 at two positions which are appropriately separated in the axial direction, so that the extending rod 30
The relative position with respect to the temperature-sensitive surface 21 is always properly maintained, and does not inadvertently tilt. on the other hand,
The ends of the second plate portions 31b and 32b of the springs 31 and 32 of the mounting member 3 which are always held in the proper posture as described above are elastically contacted with both ends in the axial direction of the thermistor 1. . Accordingly, the springs 31 and 32 act on the both ends of the thermistor 1 in the axial direction as uniformly as possible, and the entire area of the thermistor 1 in the axial direction is applied to the temperature-sensitive surface 21. As a result, the contact is made as evenly as possible, and it is reliably prevented that the contact comes up from the temperature sensing surface 21.

As a result, the heat transfer from the temperature-sensitive surface 21 to the thermistor 1 is always kept good, and the temperature detection in the thermistor 1 is performed with high reliability and with high accuracy.

Further, when the thermistor 1 is inserted into the thermosensitive cylinder 2 via the mounting member 3, the opening end 2 c of the thermosensitive cylinder 2 is connected to the lid of the mounting member 3. Covered by 34. Therefore, invasion of outside air into the temperature-sensitive cylinder 2 is prevented as much as possible. As a result, the temperature of the thermistor 1 inserted and arranged inside the temperature-sensitive cylinder 2 is affected by the outside air. Is prevented as much as possible, so that the accuracy of the temperature detection by the thermistor 1 and the reliability of the detected value are further enhanced.

Also, as in this embodiment, the lid 3
By integrally molding the thermistor 1 with the mounting member 3, the lid 34 is simultaneously mounted when the thermistor 1 is inserted into the temperature-sensitive cylinder 2 via the mounting member 3. As compared with a case where each of these mounting operations is necessary, such as a configuration in which the mounting member 3 and the lid body 34 are separately formed, the thermistor mounting operation can be simplified and the number of members can be reduced. Cost can be reduced.

[Brief description of the drawings]

FIG. 1 is a sectional view showing a thermistor mounting structure according to the present invention.

FIG. 2 is an overall perspective view of the mounting member shown in FIG.

FIG. 3 is a sectional view showing a conventional thermistor mounting structure.

[Explanation of symbols]

1 is a thermistor, 2 is a temperature sensing tube, 3 is a mounting member, 4 is a lead wire, 5 is a refrigerant tube, 21 is a temperature sensing surface, 30 is an extending rod portion, 3
1 is a first spring, 32 is a second spring, and 34 is a lid.

Claims (3)

[Claims] 1. A temperature-sensitive surface (21) having a cylindrical shape with a bottom and constituted by an outer peripheral wall thereof is exposed to a temperature environment to be measured, and an open end (2c) thereof is exposed to the outside. A thermistor (1) is installed inside the temperature-sensitive tube (2).
And the thermistor (1) is attached to the mounting member (3).
A thermistor mounting structure mounted in a state of being pressed and urged to the temperature-sensitive surface (21) through the thermo-sensitive cylinder (2), wherein the mounting member (3) is provided between the temperature-sensitive cylinder (2) and the thermistor (1). In the mounting state between the two, at least two positions on one side in the circumferential direction of the temperature-sensitive surface (21) and appropriately separated in the axial direction and at least two positions appropriately separated in the axial direction of the thermistor (1), respectively. Springs (31) and (32) for generating a predetermined urging force between the temperature-sensitive surface (21) and the thermistor (1) by elastic contact, and provided with the springs (31) and (32); A thermistor mounting structure, characterized in that the thermistor (1) is configured to be elastically biased toward the other side in the circumferential direction of the temperature-sensitive surface (21) by a force. 2. The device according to claim 1, wherein the opening end (2c) of the thermosensitive cylinder (2) is covered by a lid (34) when the thermistor (1) is mounted. Thermistor mounting structure. 3. The thermistor mounting structure according to claim 2, wherein the lid (34) is formed integrally with the mounting member (3).