JPS6116502Y2 - - Google Patents

Description

[Detailed description of the invention] This invention relates to a thermocouple input terminal housing used in a data acquisition device, etc., and in particular, to a large number of terminals used as reference junctions of thermocouples arranged in many places, and to each of these terminals. The present invention relates to a thermocouple input terminal housing provided with a common reference point compensation element.

Generally, when controlling the temperature at several dozen locations in a plant, etc., the thermocouples installed at each measurement location are connected to a recording device using respective compensating conductors, and the connection is used as a reference junction. A method is used to measure the electromotive force due to the temperature difference between the contact and each thermocouple. Therefore, it is necessary to keep the reference junction at a constant temperature using a constant temperature bath or the like, or to measure the temperature of the reference junction separately to compensate for the electromotive force generated by the thermocouple. Because of the need for this, many methods are used to compensate using the latter reference junction temperature. However, if a temperature difference occurs between each terminal as a reference junction due to the influence of outside air, heat generation of internal parts, etc., for example, if the electromotive force fluctuates by about 100 μV due to the temperature difference, the measurement range will be 10 mmV. In some cases, there was a problem that caused a measurement error of about 1%.

In view of the above points, this idea uses a plate material with good thermal conductivity, such as an aluminum plate, as the substrate for the terminal board inside the thermocouple input terminal housing, and also forms an approximately gear-shaped mounting hole in the substrate. However, by using outsert molding to attach an insulating tube that electrically insulates the terminal body and the board of the terminal board to this mounting hole, the contact area between the board and the insulating tube is expanded and heat is removed. The purpose is to improve the measurement accuracy of this type of data recording device by improving conductivity and making each insulating cylinder as thin and small as possible to maintain an even temperature between each terminal. It is.

Next, a description will be given of an embodiment shown in the drawings in which the thermocouple input terminal case according to the invention is applied to a data acquisition device.

In the figure, 1 is a data acquisition device that receives as input the electromotive force of thermocouples arranged at multiple locations.This data acquisition device 1 has a rectangular outer casing 2.
The front side is the operation panel 3, and this operation panel 3
is provided with a display device 4, a printer device 5, and various switches 6, and a stand 7 that can be used as a handbag is pivotally attached to the front side of the outer casing 2. On the other hand, an input terminal board 8 is provided at the rear inside the outer casing 2, and this terminal board 8 is mounted integrally within the input switch unit 9. This input switch unit 9 has a chassis 10 having a substantially rectangular shape with an open top.
A terminal board support frame 11 is attached to the upper part of the interior of the terminal 0, and a printed circuit board 12 of an input switch is attached to the lower part of the interior. The support frame 11 is made of a synthetic resin material with good heat insulating properties and is made by integral molding, and a stepped portion 11a is formed at an inner middle position of the support frame 11 so as to be continuous with the inner periphery. This stepped portion 11a is formed by bulging inwardly below the stepped portion 11a, and screw receiving portions 13 are formed at the four corners below this stepped portion 11a. There is.
Further, a plurality of wiring guide grooves 14 are formed in the upper part of one side of the support frame 11, and by forming the plurality of guide grooves 14, a guide block 15 protrudes between the guide grooves 14. It is formed. Furthermore, the outside of this guide block 15 is used as a wiring support stand 16, and this support stand 16 has a shape that is slightly inclined outward and downward from the same position as the bottom of the guide block 15.
A wiring clamp holder 17 is attached to the upper part of the cable. This wiring clamping tool 17 has an elongated shape with an L-shaped cross section, and one side bent into the L shape is a wiring clamping part 17a, and the other side is an outside air shielding part 17b.
It is said that Both ends of this clamp holder 17 are attached to the upper part of the support base 16 by means of mounting screws 18, 18, and this clamp holder 17 is
A rubber sheet 19 is affixed to the upper surface of the wiring support stand 16 corresponding to . Moreover, the support frame 11
The lower surface side is a shielding plate abutting part 21 to which the heat shielding plate 20 is attached, and this abutting part 21 is formed with screw holes 22 for fixing the shielding plate 20 with screws.
In addition, a terminal board 8 is provided on the bottom side of the guide block 15.
A notch 23 is formed through which a cord 35 connecting the switch and the printed circuit board 12 of the switch is inserted. By placing and fixing the terminal board 8 on the stepped portion 11a of the support frame 11, the switch unit 9 is divided into upper and lower three layers by the terminal board 8, the shielding plate 20, and the printed circuit board 12 of the switch. The space above and below the shielding plate 20 is an insulating air layer 2.
It is said to be 4.25. The shielding plate 20 is made of an aluminum plate with good thermal conductivity, and various electronic components 26 such as relays arranged on the printed circuit board 12 of the switching device are mounted on the side opposite to the direction of the shielding plate 20. That is, it is attached to the lower surface of the printed circuit board 12, so that the printed circuit board 12 itself has a function as a heat shielding plate.

On the other hand, the terminal board 8 uses a substrate 27 made of an aluminum plate or the like having good thermal conductivity.
7 is provided with 60 terminals T ₁ to _{T 60} , and these terminals
_T.sub.1 to _T.sub.60 are arranged in five parallel rows of 12 blocks, and each row is aligned with the position of the guide block 15 of the support frame 11. Furthermore, since each of the terminals T is used as a reference junction, a temperature-compensating resistance thermometer 28 is provided at a position below the top surface of the board 27 in the center of the board 27, and is capable of detecting temperature changes in the terminal board 8. The structure is designed to compensate for fluctuations in thermoelectromotive force due to Further, each terminal T is composed of a terminal main body 29, an insulating tube 30, and a fixing screw 34, among which the insulating tube 30
is attached by outsert molding to a mounting hole 32 formed at a predetermined position on the substrate 27 and whose inner periphery has an uneven shape, such as a substantially gear shape. That is,
The molds 31, 31 are overlapped from above and below the mounting hole 32 in the substrate 27, and the molten resin material P is poured into the mold 3.
1, 31, and by cooling and solidifying the upper and lower flange parts 30a, 30a and the insertion hole 30b.
An insulating cylinder 30 is formed having the following.

The insulating cylinder 30 formed in this manner has a small diameter portion having an uneven outer shape that is in close contact with the uneven inner periphery of the mounting hole 32 at the middle part of its outer periphery, and at the top and bottom of this small diameter portion. are large-diameter upper and lower flange portions 30a, 30 that are in close contact with the upper and lower surfaces of the substrate 27.
a has a shape formed by integral molding.

The terminal body 29 is inserted into the insertion hole 30b of the insulating tube 30.
is press-fitted and fixed, and this terminal body 29 has a cylindrical portion 29a inserted into the insertion hole 30b and the cylindrical portion 2.
The cylindrical portion 29a has a female thread 29c formed therein, and the lower end of the cylindrical portion 29 has a connecting protrusion 29d formed therein. The ends 33a of the conductive wires 33 from the thermocouples drawn in through the guide groove 14 are connected and fixed at respective predetermined terminals T by fixing screws 34.

Focusing on the movement of heat near the terminal board of the data acquisition device with the above configuration, heat from the outer casing 2 is first transferred to the chassis 10 of the switching unit 9, and then to the support that is in direct contact with this chassis 10. It is conducted to the frame 11. However, since the support frame 11 is integrally molded using a resin material with good heat insulation properties, and the terminal board 8 is attached to the chassis 10 via the support frame 11, the terminal board Heat conduction to 8 is prevented. In addition, the heat generated by the electronic components 26 of the switch is blocked by the heat insulating air layers 24 and 25, and since the shielding plate 20 is made of an aluminum plate with good thermal conductivity, the heat generated by the electronic components 26 of the switch is blocked by the heat insulating air layer 24. Unused heat is dissipated uniformly by the shielding plate 20. Therefore, the heat that cannot be blocked by the two heat insulating air layers 24 and 25 is transmitted to the entire terminal board 8 on average. on the other hand,
If there is a temperature difference between the air near the terminal board 8 and the outside air, the air tends to move near the wiring guide groove 14, but the conductor 3 passing through the wiring guide groove 14
3 is held down by the clamp holder 17, so
The conductor 3 below the clamping part 17a of this clamping tool 17
3 and the guide block 15 to make the airtight state.
Moreover, the upper part of the clamping part 17a is shielded from outside air by the shielding part 17b of the clamping tool 17, thereby preventing the influence of the outside air on the terminal board 8.
In this way, the terminal board 8 is almost thermally isolated from the external environment, but if heat that has not been shielded is conducted to the board 27 of the terminal board 8, the board 27
7 has good thermal conductivity, so the entire substrate 27 has the same temperature without being unevenly distributed. Furthermore, the temperature of this board 27 is conducted to the terminal body 29 via the insulating tube 30.
Since the contact area between the mounting hole 32 and the board 27 is increased by the substantially gear-shaped shape of the mounting hole 32, the heat exchange rate is improved accordingly.Moreover, since the insulating cylinder 30 is formed into a small and thin shape by outsert molding, the contact area between the board 27 and the board 27 is increased. 27
The temperature of the terminal body 29 and the temperature of the terminal body 29 are always maintained at substantially the same temperature. Thus each terminal T ₁
~T ₆₀ is hardly affected by external influences, and since each terminal T ₁ ~ _{T 60} is always kept at the same temperature, for example, the data connected to terminal T ₁ and the data connected to terminal T ₆₀ that terminal between the data
This eliminates the difference between T ₁ and T ₆₀ due to the installation position, improving measurement accuracy. In addition, the terminal board 8 in the above embodiment is provided with 60 terminals T, and since one thermocouple requires two terminals, it must be connected to thermocouples installed at 30 locations in total. Can be done. Furthermore, this terminal board 8 can also be used as an input terminal board for a resistance temperature detector, so in that case, one resistor requires three terminals.
It can be connected to resistors installed at a total of 20 locations, and even if thermocouples and resistors are input together, all terminals can be utilized by setting the number of each appropriately.

In addition to the gear shape described above, the mounting hole 32 in the above embodiment may have a star shape, a flower shape, or the like, as long as its inner periphery has an uneven shape.

As explained above, according to this invention, a metal plate material with good thermal conductivity is used as the substrate of the terminal board, and a mounting hole is formed in the substrate with an uneven shape such as a substantially gear shape. The structure is such that the convex/concave middle small diameter part and the top and bottom large diameter flange parts of the insulating tube, which has an outsert integral structure that electrically insulates the terminal body and the terminal block board, are attached to the inner periphery and the top and bottom surfaces of the board, so that The contact area between the substrate and the insulating tube is increased by the uneven surface and the upper and lower flange surfaces integrated therewith, and the degree of adhesion between the substrate and the insulating tube is also improved due to the integral structure of the insulating tube, and the thermal conductivity is improved accordingly. This has the effect of quickly reducing the temperature difference between the board and the terminal body. In addition, the middle part of the insulating tube that corresponds to the mounting hole is made into an uneven shape, such as a roughly gear shape, that is closely attached to each other, so there is no slippage between the insulating tube and the insulating tube, making it easy to attach the conductor to the terminal using a fixing screw. This has the effect of stabilizing the work, making it possible to firmly attach the conductor to the terminal, and preventing loosening. However, since the board itself is made of a material with good thermal conductivity, it prevents variations in the temperature of the board itself, and has the effect of keeping each of the many terminals attached to the board at an even temperature. Furthermore, since the insulating tube has an integral structure, it has good thermal conductivity to the internal terminal body, and since it can be made small and thin, the temperature difference between the terminal body and the board is further reduced, and the parts The score will also decrease. Therefore, with a simple and economical structure, each terminal of the terminal board can be placed under substantially the same temperature conditions, which has the effect of improving measurement accuracy.

[Brief explanation of the drawing]

The figures show an example in which this invention is applied to a data acquisition device. Fig. 1 is a partially cutaway perspective view of the data acquisition device, and Fig. 2 is a plan view of a switching unit equipped with a terminal board. Figures and Figure 3 are the same.
4 is a perspective view of the terminal board support frame from the bottom, FIG. 5 is a perspective view of the same from the top, FIG. The figure is an exploded perspective view, and FIG. 8 is an explanatory view of forming the insulating cylinder. 8... Terminal board, 27... Board, 29... Terminal body, 30... Insulating tube, 32... Mounting hole, T ₁ to _{T 60}
...Terminal.

Claims (1)

[Scope of utility model registration request] This terminal is used in a terminal board in which a large number of terminals used as reference junctions of thermocouples installed in a number of locations are attached, and in a thermocouple input terminal housing in which a common reference point compensation element is provided for each of the above-mentioned terminals. The board has a metal substrate with good thermal conductivity, and a mounting hole with an uneven inner circumference, such as a roughly gear shape, is formed in the board. The terminal body is inserted and held, and an insulating tube with a thin, integral structure that electrically insulates the terminal body and the above-mentioned board is attached, and this insulating tube has an insulating tube that fits inside the unevenness of the above-mentioned mounting hole at the middle part of its outer periphery. A small diameter portion having an uneven outer shape is formed that is in close contact with the periphery, and large diameter upper and lower flange portions that are in close contact with the upper and lower surfaces of the substrate are integrally formed above and below this small diameter portion. Thermocouple input terminal housing.