JPS5932902Y2 - RTD - Google Patents

Description

[Detailed explanation of the idea] The present invention relates to a resistance temperature sensor.

Conventionally, there have been resistors as shown in FIGS. 1 and 2, but the conventional resistance temperature sensing element used in the resistance temperature sensing element itself does not have a supporting structure.
As shown in Figure 1, a metal outer cylinder a and a conductor b,
Fill inorganic insulating powder C such as magnesia between b',
A temperature measuring resistance element e is housed in an end tube d joined to this metal outer cylinder a, and its lead wires f and f' are connected to the conductor wires b and b'.
In the case where the end tube d is filled with inorganic insulating powder C' and the open end is closed with a metal lid g, the temperature sensing resistor e is free with respect to the end tube d. As a result, the inorganic insulating powder C' cannot be filled sufficiently and densely, and as a result, the porosity (residual air) of the inorganic insulating powder C' increases, resulting in a decrease in sensitivity and resistance to temperature measurement. There was a problem in that the element e was easily shaken by vibrations, and lead wires f, f', etc. were constantly broken.

In order to solve the above-mentioned difficulties, the applicant has proposed what is shown in FIG.

This consists of a metal outer tube a, an end tube d connected to it, and a pair of conductors.

h' is installed internally, its end is fixed and conductive to the metal lid g, and the resistance temperature measuring element e is supported by the conductive wires h and h', so it is quite effective in its own way.
The work of installing a pair of conducting wires, h', in common to the metal outer tube a and the end tube d is complicated, and the manufacturing process becomes complicated.

Therefore, the present invention improves the structure that secondarily supports the resistance temperature measurement element as described above, and makes it possible to easily and reliably mechanically support the resistance temperature measurement element. The purpose of the present invention is to provide a temperature sensing resistor that does not cause cracks to form on the ceramic shell and has excellent vibration resistance.

The drawings showing the embodiments of the present invention will be described in detail below.
In FIGS. 3 and 4, a metal outer cylinder 1 and a plurality of conductive wires 2 are shown.
. Store it.

In this 5, at least one pair of conductive wires 2, 2' are connected to the metal outer cylinder 1.
A desired length is extended into the end tube 4, and this extended end is connected to the lead wires 7, 7' of the temperature sensing resistance element 6, respectively. The open end 4' of the end tube 4 is closed with a metal lid 8, and the temperature measuring resistance element 6 is supported by a support member 9 as follows. It is supported and configured.

That is, the support member 9 is made of ceramic or metal, and one end thereof has two clamping pieces 10 and 10'.
are arranged side by side at appropriate intervals to form a bifurcated shape so that the temperature measuring resistance element 6 can be tightly clamped thereto, and a support piece 11 is formed integrally extending in the axial direction from the base end 9a. At least the tip of the temperature-measuring resistance element 6 is tightly sandwiched between the clamping pieces 10 and 10', and the support member 9 is
is housed in the end tube 4 together with the temperature measuring resistance element 6, and the inorganic insulating powder 3' is filled into the end tube 4 in a covered state as described above.

At this time, the tip end of the support piece 11 of the support member 9 is allowed to extend outward from the open end 4' of the end tube 4 by the amount of fixation margin to the metal lid 8.

Therefore, while holding the supporting piece 11 and holding the supporting member 9 and the resistance temperature detector 6 at the center of the end tube 4, the inorganic insulating powder 3' is filled into the end tube 4, and then the inorganic insulating powder 3' is filled. Thereafter, the metal lid 8 is fixed to the open end 4' of the end tube 4 by welding or the like, and the metal lid 8 is fixed to the tip of the support piece 11.

Here, engagement recesses 11a, 11a are symmetrically provided on both left and right sides of the tip of the support piece 11, and an engagement recess 8a is provided in the center of the inner surface of the metal lid 8, and the engagement recess 8a is provided at the center of the inner surface of the metal lid 8. It is preferable to fix the support member 9 to the metal lid 8 by press-fitting the tip of the support piece 11 into the metal lid 8.

At this time, the engagement recess 8a has engagement protrusions 8 on the left and right sides of the opening that can be relatively engaged with the engagement recesses 11a, 11a.
b, 8b are arranged opposite each other as shown in Fig. 5, and the opening is formed narrower than the inside, and the support piece 11 can be detached by simply press-fitting the tip of the support piece 11 into the engagement recessed hole 8a. It can be easily fixed without any problems.

In this case, the temperature-measuring resistance element 6 may be made by opening a temperature-measuring resistance wire (not shown) with a ceramic shell 6a as shown in FIG. A resistance temperature measuring wire is wound between the mica exterior body and the outside of the mica exterior body, which is opened with an outer shell 6b made of a metal frame.

As explained above, according to the resistance temperature detector according to the present invention,
Since the temperature measuring resistance element 6 is installed inside the end tube 4 and is fitted and supported by the support member 9 fixed to the metal lid 8, when filling the end tube 4 with the inorganic insulating powder 3', , support piece 1
The inorganic insulating powder 3' can be filled with the inorganic insulating powder 3' while holding the resistance temperature sensor 6 together with the support member 9. Therefore, the resistance temperature sensor 6 may move and become eccentric, or the leads may Since wires 7 and 7' will not be disconnected,
The filling operation can be performed sufficiently firmly, and as a result, the porosity can be reduced, resulting in good sensitivity.
can be firmly fixed to the metal lid 8 by the support member 9,
Not only does it have excellent vibration resistance and can prevent accidental cutting of the lead wires 7, 7' and the joints between them and the resistance temperature measuring wires and the conducting wires 2, 2', but especially according to the present invention, the support member 9 can be Since it is not inserted into the metal outer cylinder 1 and only needs to be stored at the tip of the end tube 4, the manufacturing process can be simplified and costs can be reduced.
Since the resistance temperature detector element 6 is clamped and supported, and is not welded, there is a risk of safety due to welding, and if a ceramic shell resistance thermometer element is used, the outer shell The support piece 11 of the support member 9 and the metal lid 8 have the effect of preventing cracking, and the end of the support piece 11 is fitted into the engagement recessed hole 8a, and the engagement protrusion 8b, 8
b. By engaging the engaging recesses 11a and 11a with each other, they are fitted without coming off, so a fixing state comparable to welding can be obtained while avoiding welding methods that have an adverse effect. Depending on such fixing strength, the temperature-measuring resistance element 6 can be stably supported without vibration as described above.

[Brief explanation of drawings]

FIGS. 1 and 2 are longitudinal sectional side views showing conventional examples of resistance temperature detectors, and FIGS. 3 and 4 are longitudinal sectional side views showing different examples of resistance temperature detectors according to the present invention. , FIG. 5 is an enlarged longitudinal sectional side view showing an example of fixing a metal lid to a support member that holds the resistance element. 1...Metal outer cylinder, 2, 2'...Conductor wire,
3, 3'... Inorganic insulating powder, 4... End tube, 6... Resistance temperature sensor, 7, 7'...
・Lead wire, 8...Metal lid, 8a...
Engagement recessed hole, 8b...Engagement protrusion, 9...
Support member, 11...Support piece, 11a...
- Engagement recess.

Claims (1)

[Scope of utility model registration request] A metal outer cylinder is filled with an inorganic insulating powder to connect the lead wire to at least one pair of internal conducting wires, and an end tube joined to the metal outer cylinder is filled with an inorganic insulating powder and connected to the lead wire. In the case where the end tube is closed with a metal lid and the end tube is closed with a metal lid, the supporting member made of ceramic or metal holds the temperature measuring resistance element at one end in the longitudinal direction. It has a plurality of holding pieces that are parallel to each other and has a support piece on the other end in the longitudinal direction that fits into the metal lid, and an end of the support piece is provided on the inner surface of the metal lid. an engagement recess into which the part is inserted, and an engagement protrusion having a narrow entrance at the entrance of the engagement recess;
An engagement recess that can be engaged with the engagement protrusion is formed on the outer periphery of the end of the support piece, and the support member fits the end of the support piece into the engagement hole and the engagement protrusion The resistance temperature detector is fitted to the metal lid by mutually engaging the engagement recess and the resistance temperature detector, and the resistance temperature detector is supported by being clamped by a plurality of clamping pieces of the support member.