JP2014067600A - Wire connection device of programmable logic controller - Google Patents

Abstract

PROBLEM TO BE SOLVED: To increase the contact area with a conducting wire while adopting a configuration in which insulation cover of an insulation-coated wire is brought into contact with the conducting wire in being cut by a blade.SOLUTION: When an insulation-coated wire 15 is inserted between a terminal board 9 and a presser 11, and the presser 11 is moved in the direction of the terminal board 9 by operating a screw 14, a blade 10 of the terminal board 9 cuts insulation cover 17, intrudes into the insulation-coated wire 15 and comes into contact with a conducting wire 16. Since the blade 10 has a plate shape and the conducting wire 16 comes into contact with both surfaces of the blade 10, the contact area between the blade 10 and the conducting wire 16 is increased, thereby capable of lowering contact resistance.

Description

  The present invention relates to a wire connecting device for a programmable logic controller.

The programmable logic controller is equipped with a terminal block. The terminal block is supplied with power wires, wires for inputting signals from various sensors and switches to the input unit, and control signals from the output unit are output to solenoid valves and motors. Connect the wires to make it.
As the electric wire, an insulation-coated electric wire, for example, a vinyl insulation-coated electric wire is usually used. When connecting this insulated wire to the terminal block, the insulation coating at the tip is peeled off to expose the conductive wire for a desired length, and the exposed conductive wire is tightened to the terminal of the terminal block with a screw. As a result, the insulated coated electric wire is electrically connected to the terminal block and is also mechanically fixed.

However, since the work of stripping the insulation coating takes time, it has been proposed to enable terminal connection without stripping the coating. For example, Patent Document 1 discloses a press contact terminal in which a U-shaped slot is formed in a plate-like terminal, and a pair of press contact blades are formed on both inner surfaces facing each other in the open portion of the slot. In this case, the gap between the pair of press contact blades is formed in an inverted C shape that gradually narrows toward the back of the slot, and when the insulation covered electric wire is pushed between the press contact blades, the insulation cover is first cut by the press contact blades. After that, both inner side surfaces of the slot penetrate into the electric wire through the cut portions of the insulating coating so as to press-contact the inner conductive wires.
According to the configuration of Patent Document 1, since the inner surface of the slot enters the inside from the cut portion formed in the insulating coating by the press contact blade and comes into contact with the conductor, the press contact terminal and the insulating coating can be formed without removing the insulating coating. It is possible to electrically connect the conductor of the electric wire.

JP 2003-45510 A

  In the configuration of Patent Document 1, since the press contact terminal is plate-shaped and the width of the inner surface of the slot that directly contacts the conductor of the insulation coated electric wire is only the thickness of the plate material constituting the press contact terminal, the press contact terminal is the insulation coated electric wire. The area of contact with the lead wire is small, and therefore, the contact resistance between the press contact terminal and the lead wire increases, and when a large current flows, the heat generation of the electric wire and the press contact terminal becomes strong. A control device such as a programmable logic controller dislikes temperature rise, so it is difficult to adopt the configuration of Patent Document 1 that tends to generate heat.

  The present invention has been made in view of the above circumstances, and its purpose is to widen the contact area with the conducting wire while adopting a configuration in which the insulating coating of the insulated coated electric wire is cut with a blade and brought into contact with the internal conducting wire. It is providing the electric wire connection apparatus of the programmable logic controller which can do.

  In the first aspect of the invention, the wire pressing portion moves in a direction approaching the wire receiving portion, so that the blade of the terminal portion cuts the insulating coating of the insulating coated electric wire and enters the insulating coated electric wire to contact the lead wire. . In this case, since the blade has a plate shape extending in the extending direction of the insulation-coated electric wire, it comes into contact with the conductive wire on both surfaces of the plate-shaped blade. For this reason, the contact area of a conducting wire and a blade can be taken wide, and contact resistance can be made small.

  By the way, in a programmable logic controller, an insulation coated electric wire is often connected between the electric wire connecting device and the control target device and is in a state of hanging from the electric wire connecting device. For this reason, the self-weight of the part which hangs down from an electric wire connection apparatus acts on an insulation covering electric wire as drawing-out force.

  In the invention according to claim 2, since the blade is inclined with respect to the extending direction of the insulation-coated electric wire, an oblique cut is formed with respect to the insulation coating of the insulation-coated electric wire. For this reason, the force in the direction of pulling out from the insertion space (pull-out force) is received on one surface of the plate-like blade through the oblique cut, so that a larger pull-out force can be received by the blade, It is possible to effectively prevent the insulation-coated wires from coming out of the wire connecting device.

  In the invention according to claim 3, since the inclination direction changes in the reverse direction in the middle, the area receiving the pulling force can be widened as compared with the straight blade. For this reason, the blade can receive a larger pulling force, and the retaining effect for the insulation-coated electric wire is further enhanced.

Sectional drawing of the electric wire connection part which shows the 1st Embodiment of this invention and cut | disconnects the state which connected the insulation coating electric wire in the direction orthogonal to the extension direction of an insulation coating electric wire. Sectional view of the wire connection section showing the state where the insulated wire is connected, cut along the extension direction of the insulated wire Fig. 1 equivalent diagram showing the state before connecting the insulated wire Perspective view of programmable logic controller FIG. 2 equivalent view showing the second embodiment of the present invention Sectional drawing cut in a direction different from FIG. (A)-(c) is sectional drawing cut | disconnected and shown along each line of Aa, II, and Wu of FIG. 5, respectively. FIG. 5 equivalent view showing the third embodiment of the present invention 6 equivalent diagram (A)-(e) is sectional drawing cut | disconnected and shown along each line of air, oo, a car, a key, and a cake of FIG. FIG. 5 equivalent view showing the fourth embodiment of the present invention Perspective view showing another programmable logic controller

Hereinafter, the present invention will be described with reference to embodiments.
[First Embodiment]
1 to 4 show a first embodiment of the present invention. A programmable logic controller 1 includes a control unit, an input unit, an output unit, and the like in a main body 2 as shown in FIG. The terminal block 3 is provided in the lower part of the front surface of.

The terminal block 3 has a plurality of wire connection portions (wire connection devices) 4. In each wire connection portion 4, detection signals from detection elements such as various sensors and switches are input to the input portion, An electric wire for outputting a control signal from the output unit to a control target device such as a solenoid valve or a motor is connected.
Hereinafter, the programmable logic controller is referred to as PLC. Further, the front, rear, left, and right sides of the electric wire connecting portion 4 are referred to as the front side, the opposite side as the rear (back), the left hand side as the left, and the right hand side as the right when facing the front surface of the PLC 1.

  As shown in FIG. 3, the electric wire connecting portion 4 mainly includes a frame 7 configured by fixing a lid plate 6 to the front portion (left side in FIG. 3) of a U-shaped holder 5. The holder 5 is made of an electrical insulating material such as plastic and is fixed to the main body 2 of the PLC 1. The lid plate 6 is made of, for example, a metal plate, and has a screw hole 8 formed at the center.

  A terminal plate (electric wire receiving portion, terminal portion) 9 made of a good electrical conductor such as copper or aluminum is attached to the inner back surface of the holder 5. This terminal board 9 is connected to the input part and the output part in the main body 2 of the PLC 1. A metal blade 10 made of steel or the like is fixed to the central portion of the terminal plate 9 in the left-right direction (vertical direction in FIG. 3).

  Inside the holder 5, a presser (wire pressing part) 11 is fitted in front of the terminal plate 9 and is movably fitted in a direction (front-rear direction) in contact with and away from the terminal plate 9. . The presser 11 is made of, for example, metal, and a semicircular recess 12 is formed on the surface facing the terminal plate 9. A space between the pressing element 11 and the terminal plate 9 is an insertion space 13 including the inside of the recess 12. The upper and lower surfaces of the holder 5 are opened, and therefore the insertion space 13 is opened in the vertical direction through the upper and lower surfaces of the holder 5. The presser 11 may be made of an insulating material such as plastic.

  A screw 14 as an operation portion is screwed into the screw hole 8 of the lid plate 6. The tip of the screw 14 is a small diameter portion 14a. The small-diameter portion 14a of the screw 14 is inserted into a stepped hole 11a formed in the presser 11, and is rotatably connected to the presser 11 by caulking the tip. Therefore, when the screw 14 is rotated to advance and retract, the presser 11 moves in the front-rear direction.

  The insulation-coated electric wire 15 connected to the electric wire connecting portion 4 is inserted into the insertion space 13 from below. The blade 10 is a plate-like straight blade, and the length direction is the extension direction of the insulated sheathed electric wire 15 inserted into the insertion space 13, that is, the up-down direction from the terminal plate 9. It is being fixed so that it may protrude toward 11 side.

  Next, an operation in the case where the insulation-coated electric wire 15 is connected to the electric wire connecting portion 4 in the above configuration will be described. In this embodiment, as the insulation-coated electric wire 15, a vinyl insulation-coated electric wire is used which is insulation-coated with vinyl in a state where a plurality of linear conductors, that is, conductive wires 16 are bundled. Therefore, in this embodiment, the extending directions of the insulated coated electric wire 15 and the conducting wire 16 are the same.

  In order to connect the insulation-coated electric wire 15 to the electric wire connection portion 4, first, the screw 14 is rotated to move the presser 11 forward, and the insertion space 13 is expanded. Then, one end of the insulation-coated wire 15 to be connected is inserted into the insertion space 13 from the open lower surface of the holder 5. At this time, as shown in FIG. 3, the insulation-coated electric wire 15 is inserted closer to the concave portion 12 side of the presser 11 than the tip of the blade 10.

  Thereafter, the screw 14 is rotated to move the presser 11 backward. Then, the insulation coated electric wire 15 is pushed and moves backward, whereby the insulation coating 17 of the insulation coated electric wire 15 is strongly pressed against the tip of the blade 10. Thereafter, the insulation coated electric wire 15 is further pushed and moved backward, whereby the blade 10 cuts the insulation coating 17 and enters the insulation coated electric wire 15.

  The blade 10 that has entered the insulated wire 15 coincides with the extending direction of the insulated wire 15 inserted into the insertion space 13 from below with the extension direction (length direction) of the blade 10 being the vertical direction. Therefore, a part of the plurality of conductors 16 may be cut, but they are divided between the conductors 16 as shown in FIG.

  And finally, the insulated wire 15 is deformed like an ellipse which is pushed between the terminal plate 9 and the presser 11 and swells in the lateral (left and right: up and down in FIG. 1) direction. However, since the bulging in the lateral direction of the insulation-coated electric wire 15 due to this crushing is suppressed by the inner surface of the recess 12, the conductive wire 16 is pressed in the insulation coating 17, and as shown in FIG. It is strongly pressed on both sides. As described above, the insulated coated electric wire 15 is electrically connected to the terminal plate 9 and then to the input portion or the output portion via the blade 10 and is mechanically fixed to the electric wire connecting portion 4.

  Here, the blade 10 cuts one side in the radial direction of the insulating coating 17 surrounding the conductive wire 16 and inserts it between the conductive wires 16, but does not reach the point of cutting the other radial side of the insulating coating 17. The protrusion height H is set so as to hold the state buried in the conductive wire 16. In FIG. 3, the protruding height H is such that the diameter D of the insulation-coated electric wire 15, the thickness T of the insulation coating 17, and the extent to which the insulation-coated electric wire 15 is crushed between the terminal plate 9 and the presser 11. It may be determined in consideration.

  As described above, according to the present embodiment, since the blade 10 enters between the plurality of conductors 16, the plurality of conductors 16 come into contact with both surfaces of the plate-like blade 10, so that the contact between the conductor 16 and the blade 10 occurs. Since the area is large, the contact resistance between the conductor 16 and the blade 10 can be reduced. For this reason, even when a large current flows through the conducting wire 16, the degree of heat generation at the contact portion between the conducting wire 10 and the blade 10 is small, and there is no possibility of affecting the PLC 1 thermally.

[Second Embodiment]
5 to 7 show a second embodiment of the present invention. Hereinafter, the same parts as those in the first embodiment are denoted by the same reference numerals, detailed description thereof is omitted, and only different parts will be described.
In this embodiment, the blade 10 is a straight blade as in the first embodiment, and is inclined with respect to the extending direction of the insulated wire 15 inserted in the insertion space 13 as shown in FIG. It is fixed. The inclination angle α of the blade 10 at this time is such that L · sin α is equal to or less than (D-2T) when the length of the blade 10 is L, that is, in FIG. ) When viewed from the blade 10, the width in the left-right direction of the blade 10 (the width when the blade 10 is projected onto the plane along the extending direction of the insulated wire 15, that is, the projected width) B is the diameter d of the conductor 16 portion. In the following, it is particularly preferable to be equivalent to the diameter d. By defining the inclination angle α of the blade 10 in this way, the blade 10 is cut into the insulation coating 17 and enters the inside of the insulation coating electric wire 15 so as to be accommodated inside the conductor 16.

  The protruding height H of the blade 10 from the terminal plate 9 is different in each part of the blade 10 in the length direction. That is, as shown in FIG. 6 and FIG. 7, the tip of the blade 10 has a triangular shape as a whole, and the central portion in the length direction of the blade 10 is determined to be the highest. It is determined to gradually become lower toward both ends in the vertical direction. Thus, even if the blade 10 cuts the half circumference of the insulating coating 17, it does not reach the opposite half circumference (no cut).

  In this embodiment configured as described above, when the screw 14 is rotated and the presser 11 is moved backward, the blade 10 cuts the insulating coating 17 and the insulating coated electric wire 15 as in the first embodiment. Invades inside. At this time, since the blade 10 is inclined with respect to the extending direction of the insulation-coated electric wire 15, it may cut more conductors 16 when compared with the first embodiment. However, since not all of the conducting wire 16 is cut, the conducting wires 16 on both sides of the blade 10 cut by the blade 10 are electrically connected through the non-cutting conducting wire 16. For this reason, the contact portion between the conductive wire 16 and the blade 10 (portion where current can flow between both) extends over both surfaces of the blade 10, and the contact area can be increased.

  By the way, the insulation coating electric wire 15 connected to the electric wire connection part 4 of the terminal block 3 is made to hang down from the said electric wire connection part 4, and is connected to a control object apparatus. For this reason, the pulling force for pulling out the insulation-coated electric wire 15 from the electric-wire connection portion 4 acts on the electric-wire connection portion 4 due to the own weight of the insulation-coated electric wire 15 hanging from the electric wire connection portion 4. At this time, the insulation coating 17 receives the friction between the insulation coating 17 and the terminal plate 9 and the presser 11 and the pulling force of the blade 10 acting on the insulation coating electric wire 15 via the inner surface of the cut. The covered electric wire 15 is prevented from coming out of the electric wire connecting portion 4.

  In this embodiment, since the blade 10 is inclined with respect to the insulation-coated electric wire 15, the width (projection width) B in the left-right direction of the blade 10 when viewed from above in FIG. For this reason, since the area where the blade 10 receives the pulling force via the inner surface of the cut of the insulating coating 17 is widened, the blade 10 can receive a larger pulling force, and has a better effect on the retaining of the insulating coated electric wire 15. Demonstrate.

  In this embodiment, since the tip of the blade 10 has a triangular shape with the center portion having the maximum protruding height, when the insulation coating 17 is started to be cut, the tip of the highest protruding height portion of the blade 10 is insulated. It is easy to cut into the coating 17, so that the blade 10 does not slide on the surface of the insulating coating 17 and is easily cut.

  Moreover, since the blade 10 is along the extending direction of the insulated wire 15 (the extending direction of the conducting wire 16), when the insulating coating 17 is cut and penetrated into the conducting wire 16, the conducting wire 16 is formed at the tip of the highest protruding height portion. Since it enters into the state, it can avoid cutting the conducting wire 16 as much as possible.

[Third Embodiment]
8 to 10 show a third embodiment of the present invention. Hereinafter, the same parts as those in the first embodiment are denoted by the same reference numerals, and detailed description thereof is omitted. Only different parts will be described.
In this embodiment, the blade 10 is a bent blade, and as shown in FIG. 8, the blade 10 is inclined with respect to the extending direction of the insulated wire 15 inserted into the insertion space 13, and the inclination direction is reversed halfway. The direction is changing. That is, the blade 10 has a “<” shape in the length direction (vertical direction in FIG. 8), and the inclination direction changes from the lower left to the lower right (when viewed from the front) at the center in the length direction. -ing

  At this time, the inclination angle of the upper half (first blade portion 10a) and the lower half (second blade portion 10b) of the blade 10 is the same, and this inclination angle is β (greater than α in the second embodiment). And when the lengths of the first blade portion 10a and the second blade portion 10b are L / 2, respectively, (L / 2) · sin β is approximately (D-2T) or less, that is, FIG. 8, it is preferable that the projected width B of the first blade portion 10a and the second blade portion 10b when viewed from above is set to be equal to or smaller than the diameter d of the conductor 16 portion. By determining the inclination angle β of the first blade portion 10a and the second blade portion 10b in this way, the blade 10 is prevented from cutting the insulating coating 17 beyond a half circumference.

  The protrusion height H of the blade 10 from the terminal plate 9 is determined to have the longest central portion in the length direction in each of the first blade portion 10a and the second blade portion 10b, as shown in FIGS. The protrusion height is gradually decreased from the maximum protrusion height portion toward both ends in the length direction. Also by this, even if the blade 10 cuts the half circumference of the insulating coating 17, it does not reach the opposite half circumference (no cut).

  In this embodiment configured as described above, when the screw 14 is rotated and the presser 11 is moved rearward, the blade 10 cuts the insulating coating 17 and the insulating coated electric wire 15 as in the second embodiment. Invades inside. At this time, since the blade 10 is inclined with respect to the extending direction of the insulation-coated electric wire 15, it may cut more conductors 16 when compared with the first embodiment. As in the second embodiment, not all of the conductive wires 16 are cut. Furthermore, since the conducting wire 16 is originally densely accommodated in the insulating coating 17, it can be said that the electrical conductivity is not greatly affected even if the conducting wire 16 is cut to some extent.

  For this reason, since the conducting wire 16 on both sides of the blade 10 cut by the blade 10 is in an electrically connected state through the non-cutting conducting wire 16, a contact portion between the conducting wire 16 and the blade 10 (the electric current is generated between the two). The portion that can flow) extends over both surfaces of the blade 10, and the contact area can be increased.

  Further, since the inclination direction of the blade 10 is reversed in the middle, the pulling force applied to the insulating coating 17 is received by both the first blade portion 10a and the second blade portion 10b. For this reason, the area that receives the pulling force is almost twice that of the second embodiment, and the pulling force that acts on the insulating coated electric wire 15 can be received more reliably.

  In addition, since the tip of the bent portion (the boundary between the first blade 10a and the second blade 10b) is in a state of biting into the conductor 16 or the insulation coating 17, the insulation-coated electric wire 15 is caught on the tip of the blade 10. Since the first blade 10a and the second blade 10b are inclined in opposite directions, the pulling force acting on the insulation-coated electric wire 15 is applied to the first blade 10a and the second blade 10b. In addition to being easily dispersed, the radial force received by the insulated wire 15 due to the pulling force acting on the first blade 10a and the radial force received by the insulated wire 15 due to the pulling force acting on the second blade 10b Are opposite to each other, and the radial displacement of the insulating coated electric wire 15 is prevented, so that it is difficult to come out of the electric wire connecting portion 4.

  From the above, according to the present embodiment, a more excellent effect for preventing the insulation-coated electric wire 15 from coming off is exhibited.

[Fourth Embodiment]
FIG. 11 shows a fourth embodiment of the present invention. Hereinafter, the same parts as those in the first embodiment are denoted by the same reference numerals, and detailed description thereof is omitted. Only different parts will be described.
In this embodiment, the blade 10 is formed of a bent blade and is inclined with respect to the extending direction of the insulating covered electric wire 15 inserted into the insertion space 13 from the center to both sides as shown in FIG. In other words, the blade 10 has an inverted V shape with respect to the extending direction of the insulation-coated electric wire 15 (vertical direction in FIG. 11), the first blade portion 10a inclined downward to the left from the center, and the first inclined portion inclined downward to the right. It consists of two blade portions 10b.
Even if comprised in this way, the effect similar to 2nd Embodiment can be acquired.
Note that the tip of the blade 10 may be upside down with respect to FIG. 11, that is, the blade 10 may be V-shaped.

[Other Embodiments]
The present invention is not limited to the embodiments described above and shown in the drawings, and the following modifications or expansions are possible.
In the first embodiment, the blade 10 may penetrate the insulating coated electric wire 15 in the radial direction. That is, even if the tip of the blade 10 that has entered the insulation-coated electric wire 15 from one side of the coating 17 cuts the other side of the coating 17 and protrudes outside the insulation-coated electric wire 15, There is no fear of being divided, and there is no problem.
In the first embodiment, the terminal plate 9 may be omitted and the blade 10 may be directly attached to the inner surface of the holder 5 so that the holder 5 functions as an electric wire receiving portion and the blade 10 functions as a terminal portion.
The insulation covered electric wire 15 may be inserted into the electric wire connecting portion 4 of the terminal block 3 from the lateral direction.

In the second and third embodiments, the tip of the blade 10 may not be triangular, but may be a constant height blade with a constant protrusion height H.
The insulation-coated electric wire 15 is not limited to a vinyl insulation-coated electric wire.
The conducting wire 16 may be a stranded wire.
The terminal board 9 to which the blade 10 is attached may be provided on the presser 11.
The terminal portion to which the blade 10 is attached may be provided on both the presser 11 and the holder 5.
It is good also as a structure which omits the terminal board 9, and the blade 10 itself serves as a terminal part.
The operation unit is not limited to the screw 14. It is good also as a structure which moves the presser 11 with a lever (operation part).
As shown in FIG. 12, the terminal block 3 may have a configuration in which a plurality of wire connection portions 4 are arranged in the vertical direction. Also in this case, since the weight of the insulation coated electric wire 15 acts on the electric wire connecting portion 4, the present invention is effective for preventing the electric wire 15 from being pulled out.

  In the drawings, 3 is a terminal block, 4 is an electric wire connection part (electric wire connection device), 5 is a holder, 6 is a lid plate, 9 is a terminal plate (electric wire receiving part, terminal part), 10 is a blade, 11 is a presser, Reference numeral 13 denotes an insertion space, 15 denotes an insulation coated electric wire, 16 denotes a conducting wire, and 17 denotes an insulation coating.

Claims (3)

In an electric wire connecting device of a programmable logic controller that connects an insulating covered electric wire formed by covering a plurality of conductive wires with an insulating covering,
A wire receiving part;
An electric wire pressing portion that is provided so as to be movable in the direction of contact with and away from the electric wire receiving portion, and that forms an insertion space in which the insulating coated electric wire is inserted between the electric wire receiving portion, and
A terminal portion provided with at least one of the wire receiving portion and the wire pressing portion and having a plate-like blade protruding toward the other;
The plate-like blade is provided so as to extend in an extending direction of the insulation-coated electric wire inserted into the insertion space, and the wire pressing portion moves in a direction approaching the wire receiving portion, whereby the blade A wire connection device for a programmable logic controller, wherein the insulation coating of the insulation coated electric wire is cut to enter between the conductive wires in the insulation coated electric wire and contact the conductive wires. In the electric wire connection device of the programmable logic controller according to claim 1,
The wire connection device for a programmable logic controller, wherein the blade is inclined with respect to an extending direction of the insulation-coated wire inserted into the insertion space. In the electric wire connection device of the programmable logic controller according to claim 1,
The programmable logic controller, wherein the blade is a bent blade that is inclined with respect to an extending direction of the insulation-coated electric wire inserted into the insertion space, and the inclination direction changes in the reverse direction in the middle. Wire connection device.

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