JP2014106173A - Terminal block with thermistor - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide a terminal board with thermistor capable of securely detecting heat generation in an electrically conductive metal fitting without variations.SOLUTION: A terminal board 1 with thermistor includes: an insulation base 10; a plurality of electrically conductive metal fittings 20 fixed onto the base 10; and a thermistor substrate 40 where three thermistors 41 are mounted and that is accommodated in a substrate housing section 15 of the base 10. In the base 10, ribs 12 are provided between neighboring electrically conductive metal fittings 20 for insulating them. Storage grooves 16 each capable of individually storing each thermistor 41, are formed on an undersurface that forms part of the substrate housing section 15 in the rib 12.

Description

  The present invention relates to a terminal block with a thermistor in which a thermistor for temperature detection is attached to a base.

  Conventionally, in a temperature compensation device for a terminal block comprising a terminal block to which a plurality of thermocouples are connected, a plurality of temperature sensors (provided on the terminal block and arranged so that the temperatures of all terminals of the terminal block can be inferred) A thermistor), and an interpolation calculation circuit that performs temperature compensation of the thermocouple connected to each terminal by analogizing the temperature distribution of each terminal of the terminal block from the signals from the plurality of temperature sensors. (For example, refer to Patent Document 1).

JP 2001-99720 A

  However, the conventional terminal block described above has a problem in that the accommodation state of each thermistor inside the terminal block is likely to vary, and the temperature detection is likely to vary due to this.

  The present invention has been made in view of the above-described problems, and an object of the present invention is to provide a terminal block with a thermistor that can reliably detect heat generation in a conductive metal fitting with a thermistor without variation.

  The invention according to claim 1, which has been made to achieve the above object, includes an insulating base (10), a plurality of conductive metal fittings (20) fixed to the base, and one or more thermistors ( 41) is a terminal block having a thermistor substrate (40) which is mounted and accommodated in the substrate accommodating portion (17) of the base, and the base insulates between the adjacent conductive metal fittings A rib (13) is provided, and an accommodation groove (18) capable of individually accommodating each thermistor is formed on a surface of the rib forming a part of the substrate accommodation portion.

  According to this configuration, the base is provided with the ribs that insulate them between the adjacent conductive metal fittings, the housing groove is formed on the surface of the rib that forms a part of the substrate housing portion, and each thermistor accommodates each housing. Since it is individually housed in the groove, if heat is generated in the conductive metal fitting when energized due to poor connection or the like, the heat generation is reliably detected by the thermistor housed in the storage groove provided in the rib adjacent to the conductive metal fitting. . That is, since the accommodation groove for individually accommodating the thermistor is formed in a rib provided between adjacent conductive fittings, the thermistor is positioned in the vicinity of the conductive fitting that is a heat source. Therefore, heat generation in the conductive metal fittings on both sides sandwiching the rib can be reliably detected without variation. Further, the rib is a structure that is originally necessary for insulating adjacent conductive metal fittings, and the rib is provided with a housing groove for housing the thermistor, so that the thermistor can be disposed in a space-saving manner.

  The invention according to claim 2 is characterized in that the thermistor is a chip type thermistor (41), and the opening of the accommodation groove is closed by the thermistor substrate in a state in which the chip type thermistor is accommodated.

  According to this configuration, since the thermistor is a chip-type thermistor, the thermistor can be compactly arranged inside the base, and the accommodation groove for accommodating the thermistor is reduced, and the opening of the accommodation groove 16 by the thermistor substrate 40. As a result, the temperature can be detected with even less variation.

  The invention according to claim 3 is characterized in that the accommodation groove is formed so that the entire exposed surface of the thermistor is in surface contact with or in the vicinity of the inner wall of the accommodation groove.

  According to this configuration, since the entire exposed surface of the thermistor is in surface contact with or close to the inner wall of the housing groove, the influence of the temperature drop due to the air between the thermistor and the inner wall is eliminated, and the heat source is provided via the rib. A temperature closer to the temperature of the conductive metal fitting can be detected. Note that the inner wall of the “accommodating groove” and the “thermistor” may be in the form of surface contact or surface proximity over the entire exposed surface, and the shape of both is not limited. For example, when the thermistor has a rectangular parallelepiped shape, it is preferable that the receiving groove has a groove shape having a rectangular groove section that substantially matches the outer shape of the thermistor.

  The invention described in claim 4 is characterized in that a gap between the inner wall of the housing groove and the thermistor housed in the housing groove is 0.1 to 1.0 mm.

  According to this configuration, since the gap between the inner wall of the housing groove and the thermistor is very small, it is possible to reliably eliminate the influence of the temperature drop due to the atmosphere. In addition, since the clearance is secured, the thermistor can be easily accommodated in the accommodation groove, and can be easily removed even when the thermistor substrate needs to be replaced.

  The invention according to claim 5 is characterized in that a plurality of the receiving grooves are arranged in a straight line, and the thermistors are received in every other receiving groove.

  According to this configuration, by detecting the temperature in the two conductive metal fittings sandwiching the rib provided with the housing groove with one thermistor, while reducing the number of necessary thermistors and reducing the cost, Heat generation in each conductive metal fitting can be detected individually.

  According to a sixth aspect of the present invention, the conductive metal fitting is a metal plate fixed to a pedestal portion (11) on the upper surface of the base, and a plurality of terminal screws (30) are provided on the surface thereof. The portion is formed on the bottom side of the base, and includes a bottom cover (60) that is detachably attached to the bottom of the base and covers the entire base bottom including the substrate housing portion. It is characterized by that.

  According to this structure, the state which accommodated the thermistor board | substrate in the board | substrate accommodating part with the bottom face cover, and accommodated the thermistor in the accommodation groove | channel can be hold | maintained. Further, it is possible to prevent the thermistor substrate and the thermistor from being damaged by an external impact, and to prevent the adhesion of dust and the like.

  The invention according to claim 7 has a plate shape that substantially matches the opening shape of the substrate housing portion, covers the thermistor substrate that is detachably attached to the substrate housing portion and is housed therein, and protects the thermistor substrate. A protective cover (50) is provided.

  According to this configuration, in addition to the bottom cover that covers the entire bottom surface of the base including the substrate housing portion, the plate has a plate shape that substantially matches the opening shape of the substrate housing portion and is attached to the bottom surface of the substrate housing portion. Since the protective cover that covers and protects the thermistor substrate housed in the housing is further attached, the hermeticity of the substrate housing portion can be improved and the heat generation can be detected more reliably.

As for invention of Claim 8, the said protective cover is provided with the projection part (52) on the upper surface,
The protrusion of the protective cover is in contact with the lower surface of the thermistor substrate housed in the substrate housing portion, and the thermistor substrate is pressed against the surface of the substrate housing portion where the housing groove is provided. To do.

  According to this structure, since the projection part reliably holds the state of pressing the thermistor accommodated in the accommodation groove and accommodated in the accommodation groove, the temperature can be accurately detected.

  The invention according to claim 9 is characterized in that a temperature-sensitive seal (55) whose color changes irreversibly with a change in temperature is attached to the protective cover.

  According to this configuration, if there is even an accident that generates heat above the specified temperature in the conductive metal fitting, the color of the temperature-sensitive seal will change and will not return to its original state. Can do. In other words, thermistors themselves can be used again if they return to room temperature, even if they become temporarily hot, unlike temperature fuses, where the fuse blows at high temperatures and cannot be reused. Whether or not an accident has occurred can be determined by visually confirming the color of the temperature-sensitive seal.

It is a front view which shows the terminal block with a thermistor of one Embodiment of this invention. It is a right view which shows the terminal block with a thermistor of this embodiment. It is a top view which shows the terminal block with a thermistor of this embodiment. It is a bottom view which shows the terminal block with a thermistor of this embodiment. It is the VV line expanded sectional view of FIG. 1 which shows the terminal block with a thermistor of this embodiment. It is the VI-VI line expanded sectional view of FIG. 3 which shows the terminal block with a thermistor of this embodiment. It is a bottom view which shows the state which removed the bottom cover, the protective cover, and the thermistor board | substrate in the terminal block with a thermistor of this embodiment. It is a bottom view which shows the state which removed the bottom cover and the protective cover in the terminal block with a thermistor of this embodiment. It is a bottom view which shows the state which removed the bottom face cover in the terminal block with a thermistor of this embodiment. It is a top view which shows the thermistor board | substrate of this embodiment. It is a top view which shows the protective cover of this embodiment.

  Hereinafter, an embodiment in which a terminal block with thermistor according to the present invention is embodied will be described with reference to the drawings.

  The thermistor-equipped terminal block 1 is a terminal block used for relay connection of electric wires, and as shown in FIGS. 1 to 9, an insulating base 10 and the number of poles fixed to the base 10 (Six in this embodiment) conductive metal fittings 20, terminal screws 30 twice as many as the number of poles of conductive metal fittings 20 (total of 6 on the input side and 6 on the output side), and thermistor substrate 40 A protective cover 50, a bottom cover 60, and a symbol plate 80.

  As shown in FIGS. 1 to 9, the base 10 is a member having a horizontally long block shape in which an insulating resin material such as PBT (polybutylene terephthalate) is molded, for example, as shown in FIGS. A pedestal portion 11 arranged in a line for the number of poles (six) in the left-right direction, a number of poles -1 (five) ribs 12 erected between the pedestal portions 11 adjacent to the left and right, and 6 It has a partition wall 13 provided at the center in the front-rear direction of each pedestal portion 11 and extending left and right, a mounting portion 14 projecting laterally from both left and right ends, and a substrate housing portion 15 provided on the bottom surface side. Yes.

  The pedestal portion 11 is a flat portion to which the conductive metal fittings 20 are fixed one by one, and is formed across the front side region and the rear side region with the partition wall 13 therebetween, one being used as the input side and the other as the output side. Is done. Holes through which the foot portions of the terminal screws 30 are inserted are formed in the front region and the rear region of the base portion 11.

  The rib 12 is a wall-shaped portion that is provided between the pedestal portions 11 adjacent to the left and right on the upper surface of the base 10 and has a substantially rectangular shape in side view.

  The partition wall 13 is a wall-shaped portion that is provided at the center of the six base parts 11 in the front-rear direction on the upper surface of the base 10 and has a horizontally long rectangular shape when viewed from the front. The partition wall 13 has a role of partitioning the front side and the back side (input side and output side) of each pedestal portion 11. Further, the upper surface of the partition wall 13 also serves as a portion to which the symbol plate 80 is attached.

  The mounting portion 14 is erected on the sides of the pedestal portions 11 at both the left and right ends, and serves as a partition wall, and attaches the base 10 to a mounting target such as a casing of the apparatus via mounting screws (not shown). A screw insertion groove 14a that also has a role and penetrates vertically is formed.

  5-9, the board | substrate accommodating part 15 is a space part which exhibits the shape of a horizontal rectangular parallelepiped shape in which a lower surface opens in the front-back direction center of the base 10 bottom side, and an inner periphery is from the planar shape of the thermistor board 40. Is also formed slightly larger. The substrate accommodating portion 15 accommodates the thermistor substrate 40 therein.

  An accommodation groove 16 is formed on the surface forming the upper portion of the substrate accommodation portion 15 and at the crossing position with the partition wall 13 on the lower surface of each rib 12.

  That is, the plurality of receiving grooves 16 are linearly arranged in the left-right direction on the lower surface of the rib 12. The accommodation groove 16 individually accommodates each thermistor 41 mounted on the thermistor substrate 40. The housing groove 16 has a rectangular groove cross section that is slightly larger than the outer shape of the thermistor 41, and is formed so that the inner wall surface of the housing groove 16 is in surface contact with or close to the thermistor 41. Furthermore, in a state where the thermistor 41 is accommodated in the accommodation groove 16, it is formed so as to have a predetermined gap (for example, 0.1 to 1.0 mm, more preferably 0.3 to 0.5 mm). desirable. Although the number of the accommodation grooves 16 can be arbitrarily set, in this embodiment, five accommodation grooves 16 which are the same number as the number of the ribs 12 are provided.

  The conductive metal fitting 20 is a plate-like member having a substantially rectangular shape in plan view produced by processing a metal having good conductivity (such as copper or brass), and is attached to the base 10 in front and rear sides of the partition wall 13. One female screw hole 21 into which the terminal screw 30 is screwed is formed.

  The terminal screw 30 is a male screw made of a metal such as iron and is screwed into each female screw hole 21 of the conductive metal fitting 20. The electric wire is sandwiched and connected between the terminal screw 30 (specifically, the head) and the end face of the conductive metal fitting 20. The end of the electric wire is preferably provided with a crimp terminal, a crimp sleeve or the like from the viewpoint of improving connection workability and suppressing poor connection. Inappropriate situation (so-called poor connection) such as insufficient fastening force between the conductive metal fitting 20 and the terminal screw 30, loosening due to external factors (for example, vibration, etc.), or dust or oil or the like being caught. There is a case. If an inappropriate situation occurs, contact resistance may be generated between the electric wire and the conductive metal fitting 20 to generate heat. In order to suppress contact resistance as much as possible, bonding (for example, welding, soldering, etc.) may be performed on the electric wire sandwiched between the terminal screw 30 and the conductive metal fitting 20.

  The thermistor board 40 is a printed circuit board on which the thermistor 41 is mounted, and has a horizontally long rectangular shape that is substantially aligned with the board housing 15 as shown in FIGS. In the present embodiment, three thermistors 41 are linearly arranged at intervals, and each thermistor 41 is connected in series by a conductor pattern 42 printed on the thermistor substrate 40. The thermistors 41 at the left and right ends are respectively connected to one end of the pair of lead wires 43 and the other end, and the other ends of the lead wires 43 are respectively connected to the connectors 45.

  The thermistor 41 is an element that exhibits a large resistance change with respect to a temperature change. For example, the thermistor 41 is a chip-type thermistor having a rectangular parallelepiped shape with a side of about 1 to 3 mm. As the thermistor 41, for example, a thermistor having a resistance value of 10 times or more at 90 ° C. with respect to the resistance value at 25 ° C. can be used.

  As shown in FIGS. 5, 6, 9, and 11, the protective cover 50 has a plate shape that substantially matches the opening shape of the substrate housing portion 15, is attached to the bottom surface of the substrate housing portion 15, and is accommodated therein. It is a resin cover member that covers and protects the thermistor substrate 40. The protective cover 50 is provided with a protrusion 52 on its upper surface, the protrusion 52 abuts against the bottom surface of the thermistor substrate 40 accommodated in the substrate accommodating portion 15, and the thermistor substrate 40 is accommodated in the accommodating groove of the substrate accommodating portion 15. 16 is pressed against the surface provided. Further, a temperature-sensitive seal 55 whose color changes irreversibly due to a temperature change is attached to the upper surface of the protective cover 50 (the surface facing the thermistor substrate 40). The temperature-sensitive seal 55 may be, for example, white in the initial state and irreversibly changing to red at a predetermined temperature (for example, 100 ° C.) or higher.

  The bottom surface cover 60 is made of the same resin material as the base 10 and is a cover member that covers the entire bottom surface of the base 10 including the substrate housing portion 15 as shown in FIGS. It is detachable.

  As shown in FIGS. 1, 3, 5, 6, etc., the symbol plate 80 is an elongated rectangular plate made of synthetic resin having a length substantially the same as the left and right lengths of the partition wall 13. A symbol for identifying the electric wire is directly written on the upper surface, or a seal indicating the symbol is attached. The symbol plate 80 is placed on the upper surface of the partition wall 13 and the intersection of the partition wall 13 and each rib 12.

  As is clear from the above detailed description, the terminal block 1 with thermistor of the present embodiment includes an insulating base 10, a plurality of conductive fittings 20 fixed to the base 10, and three thermistors 41. A thermistor substrate 40 that is mounted and accommodated in the substrate accommodating portion 15 of the base 10, and the base 10 is provided with ribs 12 that insulate them between adjacent conductive fittings 20. An accommodation groove 16 capable of individually accommodating each thermistor 41 is formed on the lower surface forming a part of the accommodation portion 15.

  According to this configuration, the base 10 is provided with the rib 12 that insulates between the adjacent conductive fittings 20, and the receiving groove 16 is formed on the lower surface of the rib 12 that forms a part of the substrate receiving portion 15. Since each thermistor 41 is individually housed in each housing groove 16, if heat is generated in the conductive metal fitting 20 during energization due to poor connection or the like, the housing groove 16 provided in the rib 12 adjacent to the conductive metal fitting 20 Heat generation is reliably detected by the housed thermistor 41. That is, since the accommodation groove 16 for individually accommodating the thermistor 41 is formed in the rib 12 provided between the adjacent conductive fittings 20, the thermistor 41 is positioned in the vicinity of the conductive fitting 20 that is a heat source. Therefore, the heat generation in the conductive metal fittings 20 on both sides of the rib 12 can be reliably detected without variation. In addition, the rib 12 is a configuration that is originally necessary to insulate the adjacent conductive metal fittings 20 from each other. Since the rib 12 is provided with the receiving groove 16 for receiving the thermistor 41, the thermistor 41 is disposed in a space-saving manner. can do.

  In the present embodiment, since the thermistor 41 is a chip-type thermistor, the thermistor 41 can be compactly arranged inside the base 10, and the accommodation groove 16 for accommodating the thermistor 41 becomes smaller and the thermistor substrate 40. As a result, the opening of the receiving groove 16 is closed and a substantially hermetically sealed state is obtained, so that temperature detection with even less variation is possible.

  In the present embodiment, the accommodation groove 16 is formed so that the entire exposed surface of the thermistor 41 is in surface contact with or close to the inner wall of the accommodation groove 16. The influence of the temperature drop is eliminated, and a temperature closer to the temperature of the conductive metal fitting 20 that is a heat source can be detected via the rib 12. In addition, the inner wall of the accommodation groove | channel 16 and the thermistor 41 should just be a surface contact or the surface proximity | contact relationship in the whole exposed surface, and both shapes are not ask | required. For example, when the thermistor 41 has a rectangular parallelepiped shape, the receiving groove 16 preferably has a groove shape having a rectangular groove section that substantially matches the outer shape of the thermistor 41.

  Moreover, in this embodiment, the clearance gap between the inner wall of the accommodation groove | channel 16 and the thermistor 41 accommodated in the accommodation groove | channel 16 is 0.1-1.0 mm, More preferably, it is 0.3-0.5 mm. . Therefore, since the gap between the inner wall of the accommodation groove 16 and the thermistor 41 is very small, it is possible to reliably eliminate the influence of the temperature drop due to the atmosphere. Further, by ensuring the clearance, the thermistor 41 can be easily accommodated in the accommodating groove 16 and can be easily removed even when the thermistor substrate 40 needs to be replaced.

  When the temperature of the conductive metal fitting 20 is increased to the heat resistant temperature of 150 ° C., the temperature measured at the position where the thermistor 41 is disposed is about 60 ° C. in the structure in which the housing groove 16 is not provided. In the structure of this embodiment provided with a temperature of about 90 ° C. was measured. From this, it can be seen that the structure in which the accommodation groove 16 is provided largely eliminates the influence of the temperature drop due to the atmosphere.

  In the present embodiment, a plurality (five) of the receiving grooves 16 are formed in a straight line, and the thermistor 41 is placed in every other receiving groove 16, specifically the first from the left, The third and fifth accommodation grooves 16 are accommodated. Therefore, by detecting the temperature in the two conductive metal fittings 20 adjacent to each other across the rib 12 provided with the housing groove 16 with one thermistor 41, the number of necessary thermistors 41 is suppressed and the cost is reduced. The heat generation in each conductive metal fitting 20 can be detected individually.

  Further, in the present embodiment, the conductive metal fitting 20 is a metal plate fixed to the pedestal portion 11 on the upper surface of the base 10, a plurality of terminal screws 30 are provided on the surface thereof, and the substrate housing portion 15 is provided on the base 10. The bottom cover 60 is detachably attached to the bottom surface of the base 10 and covers the entire bottom surface of the base 10 including the substrate housing 15. Therefore, the state in which the thermistor substrate 40 is accommodated in the substrate accommodating portion 15 and the thermistor 41 is accommodated in the accommodating groove 16 by the bottom cover 60 can be maintained. Further, it is possible to prevent the thermistor substrate 40 and the thermistor 41 from being damaged due to an impact from the outside, and to prevent adhesion of dust and the like.

  In this embodiment, in addition to the bottom surface cover 60 that covers the entire bottom surface of the base 10 including the substrate housing portion 15, it has a plate shape that substantially matches the opening shape of the substrate housing portion 15, and is attached to and detached from the substrate housing portion 15. A protective cover 50 is provided that can be attached and covers and protects the thermistor substrate 40 accommodated in the substrate accommodating portion 15. According to this configuration, the protective cover 50 can improve the hermeticity of the substrate housing portion 15 and more reliably detect heat generation.

  In the present embodiment, the protective cover 50 is provided with a protrusion 52 on the upper surface thereof, and the protrusion 52 of the protective cover 50 abuts on the lower surface of the thermistor substrate 40 accommodated in the substrate accommodating portion 15. The substrate 40 is pressed against the surface of the substrate housing portion 15 where the housing groove 16 is provided. Therefore, the protrusion 52 reliably holds the state of pressing the thermistor 41 accommodated in the accommodation groove 16 and accommodated in the accommodation groove 16, so that the temperature can be accurately detected.

  In the present embodiment, the protective cover 50 is attached with a temperature-sensitive seal 55 whose color changes irreversibly due to a temperature change. Therefore, if there is even an accident that generates heat above the predetermined temperature in the conductive metal fitting 20, the color of the temperature-sensitive seal 55 changes and does not return to the original, so that the occurrence of the accident can be confirmed afterwards. . In other words, the thermistor 41 is different from a thermal fuse in which the fuse is blown at a high temperature and cannot be reused. Whether or not an occurrence has occurred cannot be determined, but the presence or absence of an accident can be determined by visually checking the color of the temperature-sensitive seal 55.

  Note that the present invention is not limited to the above-described embodiment, and various modifications can be made without departing from the gist of the present invention.

DESCRIPTION OF SYMBOLS 1 Terminal block with a thermistor 10 Base 11 Base part 12 Rib 13 Bulkhead 14 Mounting part 15 Substrate accommodating part 16 Accommodating groove 20 Conductive metal fitting 30 Terminal screw 40 Thermistor board 41 Thermistor 42 Conductive pattern 43 Lead wire 45 Connector 50 Protective cover 52 Projection part 55 Temperature-sensitive seal 60 Bottom cover 80 Symbol plate

Claims (9)

An insulative base (10), a plurality of conductive metal fittings (20) fixed to the base, and one or a plurality of thermistors (41) are mounted in the board housing portion (15) of the base. A terminal block having a thermistor substrate (40) accommodated therein,
The base is provided with ribs (12) that insulate them between the adjacent conductive fittings,
A terminal block with a thermistor, wherein a housing groove (16) capable of individually accommodating each of the thermistors is formed on a surface of the rib forming a part of the substrate housing portion. The thermistor is a chip-type thermistor (41),
2. The terminal block with thermistor according to claim 1, wherein the opening of the receiving groove is closed by the thermistor substrate in a state where the chip-type thermistor is received.   The terminal block with thermistor according to claim 1, wherein the housing groove is formed such that the entire exposed surface of the thermistor is in surface contact with or in the vicinity of the inner wall of the housing groove.   The terminal block with thermistor according to claim 3, wherein a gap between an inner wall of the housing groove and the thermistor housed in the housing groove is 0.1 to 1 mm. A plurality of the receiving grooves are arranged in a straight line;
5. The terminal block with thermistor according to claim 1, wherein the thermistor is housed in every other plurality of the housing grooves. 6. The conductive metal fitting is a metal plate fixed to the base (11) on the upper surface of the base, and a plurality of terminal screws (30) are provided on the surface thereof.
The substrate accommodating portion is formed on the bottom side of the base,
The bottom cover (60) which is detachably attached to the bottom of the base and covers the entire bottom of the base including the substrate housing portion is provided. Terminal block with thermistor.   A protective cover (50) having a plate shape substantially matching the opening shape of the substrate housing portion and detachably attached to the substrate housing portion and covering and protecting the thermistor substrate housed in the substrate housing portion. The terminal block with thermistor according to claim 6, further comprising: The protective cover is provided with a protrusion (52) on its upper surface,
The protrusion of the protective cover is in contact with the lower surface of the thermistor substrate housed in the substrate housing portion, and the thermistor substrate is pressed against the surface of the substrate housing portion where the housing groove is provided. The terminal block with a thermistor according to claim 7.   9. The terminal block with thermistor according to claim 8, wherein the protective cover is attached with a temperature-sensitive seal (55) whose color changes irreversibly due to a temperature change.

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