JP2009064738A - Terminal device of switch - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To provide a terminal device of a switch which ensures the necessary strength of an inter-phase barrier by only changing the terminal board shape of a fixed contactor and a body case to improve reliability. <P>SOLUTION: According to the terminal device of the switch, a terminal-integrated fixed contactor 8 is disposed on a terminal pedestal 3c to be held at a fixed position. A terminal portion 8-1 of the fixed contactor 8 has tab-shaped engaging projections 8d projecting laterally from the rear end of the left/right side edges of the terminal portion 8-1, and a cantilevered engaging arm 8e projecting froward from the center of the terminal portion 8-1. A body case has engaging slots 3a-1 and 3b-1 into which the engaging projections 8d are fitted along the root of inter-phase barriers 3a and 3b and which have a short depth length d, and an engaging hole 3d into which the engaging arm 8e is fitted toward the far side of the terminal pedestal 3c. When the fixed contactor 8 is attached, the engaging projections 8d and the engaging arm 8e are fitted into the engaging slots 3a-1 and 3b-1 and the engaging hole 3d, respectively, to lock the fixed contactor 8 at a fixed position. <P>COPYRIGHT: (C)2009,JPO&INPIT

Description

  The present invention relates to a terminal device of a switch for electromagnetic contactors and the like, and more particularly to a support structure for a terminal-integrated fixed contact disposed on a terminal base portion of a main body case.

In the magnetic contactor described above, the terminal base corresponding to each phase is arranged in a horizontal row at the power supply side and the load side end of the main body case that becomes a molded resin molded product, and the left and right sides of the terminal base of each phase are erected. An interphase barrier is provided, and terminal-integrated fixed contacts corresponding to the respective poles arranged on the terminal base are insulated and fixed.
In addition, in order to fix the fixed contact arranged on the terminal pedestal, the fixed contact is provided with tab-like engagement protrusions protruding laterally from the left and right side edges, and the interphase barrier of the main body case is provided. Generally, a support structure is adopted in which a concave groove is formed in the insertion direction of the fixed contact along the left and right sides of the terminal base, and the engaging protrusion is press-fitted into the concave groove to fix the fixed contact. (For example, see Patent Document 1 and Patent Document 2).
Next, the entire structure of the electromagnetic contactor and the conventional support structure for the stationary contact are shown in FIGS. First, in FIGS. 5A and 5B, 1 is a main body case (molded resin molded product) composed of a lower frame 2, an upper frame 3, and an arc extinguishing chamber cover 4, and 5 is an operation electromagnet built in the lower frame 2. , 6 is a contact holder mounted with a bridge-type movable contact 7 and connected to the movable iron core of the operation electromagnet 5, and 8 is attached to a terminal block formed on both ends (power supply side and load side) of the upper frame 3. The terminal-integrated fixed contact, 9 is a terminal screw, and 10 is an auxiliary contact unit constructed on the left and right side surfaces of the main body case 1.

Here, the terminal blocks (power supply side, load side) of the upper frame 3 are arranged on the left and right sides of each terminal base 3c, and the terminal bases 3c arranged in a left and right line corresponding to each phase of the main circuit (three-phase circuit). Interphase barriers (insulating partition walls) 3a and 3b are formed that insulate and isolate the fixed contacts 8 that are erected and disposed on the terminal base 3c. Reference numeral 3a denotes a barrier erected on both right and left ends, and 3b denotes an intermediate interphase barrier erected between adjacent terminal bases 3c.
On the other hand, the fixed contact 8 (see FIG. 6 (a)) has a fixed contact 8a fixed to a contact support portion extending in front and continuing to a flat terminal portion, and a terminal screw 9 is screwed to the terminal portion. The screw holes 8b to be joined are opened, and tab-like locking projections 8c and 8d are formed on the left and right edges of the terminal portion so as to protrude side by side along the front and rear ends. The engaging protrusion 8c formed at the front part of the terminal part is a press-fitting protrusion for fixing, and is press-fitted into a concave groove formed at the base part of the interphase barrier described later to fix and hold the fixed contact 8 in place. . On the other hand, the engagement protrusion 8d at the rear part is inserted into the concave groove of the interphase barrier in a non-press-fit manner as a protrusion for preventing lifting, and when an external force is applied to the electric wire connected to the stationary contact 8, Plays the role of preventing the terminal base 3c from floating up.
In addition, the terminal base 3c of the upper frame 3 of the main body case corresponding to the fixed contact 8 has an engaging groove 3a− at the base of the interphase barriers 3a and 3b along the left and right sides of the terminal base 3c. 1, 3b-1 is formed, and during assembly, the fixed contact 8 is inserted on the terminal base 3 from the direction of the arrow, and the engaging protrusions 8c, 8d protruding sideways are inserted into the concave grooves, The engagement protrusion 8c is press-fitted into the engagement grooves 3a-1 and 3b-1, and fixedly supported at a fixed position so that the fixed contact 8 is not displaced or dropped. FIG. 6C is an enlarged cross-sectional view of the concave groove 3b-1 formed at the root of the interphase barrier 3b.
Japanese Patent No. 2797261 (FIG. 4) JP 2006-278002 A (FIG. 4)

However, the conventional fixed contact support structure shown in FIG. 6 has the following problems.
That is, corresponding to the engagement protrusions 8c formed on the left and right side edges of the terminal portion of the stationary contact 8, the grooves 3a-1, 3b-1a is formed, and the engaging protrusion is inserted into the concave groove to hold the fixed contact 8 in place. For this reason, the thickness of the base part of the interphase barriers 3a and 3b in which the concave grooves 3a-1 and 3b-1 are formed is reduced. In this case, the interphase barriers 3a arranged on the outer side are formed with the concave grooves 3a-1 only on the inner side surface, so that the reduction rate of the thickness is small. However, the interphase barriers 3b arranged in the middle have the concave grooves 3b- 1 is formed, the wall thickness is reduced, and the thickness t1 of the base portion is about half of the thickness t, where t is the thickness of the interphase barrier 3b (see FIG. 6C). Engaging protrusions 8c and 8d are formed on the front and rear portions of the terminal portion on both side edges of the stationary contact 8, and the concave groove 3a-1 is used to push the terminal portion into place and hold it in place. , 3b-1, and thus the length of the thin wall portion of the barrier corresponds to the terminal portion.
On the other hand, when connecting an external electric wire to the magnetic contactor, a crimp terminal is used. As shown in FIG. 7, the crimp terminal 11 attached to the electric wire is overlapped with the terminal portion of the fixed contact 8 and the terminal screw 9 is moved in the direction of the arrow. When tightened, the crimp terminal 11 that rotates along with the tightening operation of the terminal screw 9 abuts against the side surface of the interphase barrier and presses this portion, and a pressing load f from the side as indicated by the arrow in FIG. 6C is applied. It becomes like this. In addition, relatively long grooves 3a-1 and 3b-1 having a depth length d corresponding to the terminal portions of the stationary contact 8 are formed at the base of the interphase barrier, as described above. Since the engagement protrusion 8c of the fixed contact 8 is press-fitted and stress is generated in the thin wall portion of the barrier wall, the bending strength is lowered. Therefore, when the pressing load f is received, stress concentrates on the base portion of the interphase barrier and cracks may occur or the interphase barrier 3b may be easily damaged from the base.

Therefore, in the past, reinforced plastics such as fiber reinforced plastic (FRP) have been used as the molding resin to increase the strength of the interphase barrier. However, reinforced plastics are more expensive than general engineering plastics and have a mold. The molding conditions are also strict, which causes a problem that the product is expensive.
The present invention has been made in view of the above points, and it is only necessary to slightly change the shapes of the stationary contact and the terminal base part of the main body case, and an interphase barrier is necessary without using an expensive reinforced resin material. An object of the present invention is to provide an improved terminal device for a switch that secures bending strength to improve product reliability and reduce costs.

In order to achieve the above object, according to the present invention, a terminal base arranged in a horizontal row in a body case made of molded resin, and interphase barriers erected on both the left and right sides of each terminal base are provided, and the terminal base is provided on the terminal base. In the terminal device of the switch in which the terminal-integrated fixed contact having the above structure is arranged and fixed and held in place,
The terminal portion of the fixed contact is provided with a tab-like engagement protrusion protruding sideways from the left and right side edges, and a cantilever-like engagement arm protruding forward from the front edge center of the terminal portion. On the case side, there are formed an engaging groove into which the engaging protrusion fits along the root part of the interphase barrier, and an engaging hole part into which the engaging arm fits into the back side of the terminal pedestal. At the time of mounting, the engaging protrusion and the engaging arm are inserted into the engaging groove and the engaging hole of the main body case, respectively, and the fixed contact is held in place (specifically, claim 1). The configuration is as follows.
(1) An engagement protrusion of the fixed contact is formed on the side edge of the rear end opposite to the fixed contact, and the engagement arm is formed by cutting out from a contact support portion that extends forward and continues to the terminal portion. Item 2).
(2) A retaining engagement protrusion is provided at the upper end of the engagement arm, and the retaining engagement protrusion is locked to the engagement hole portion of the main body case at the fixed contact mounting position. 3).

With the above configuration, in the mounted state in which the terminal-integrated fixed contact is assembled to the terminal base part of the main body case, the fixed contact is attached to the engagement arm extending forward from the center of the terminal part and the left and right side edges of the terminal part. Three points are supported by the formed engagement protrusion, and the fixed contact is locked and fixed so that it does not deviate from or fall off from a fixed position. Further, by forming the engaging protrusion at the rear end of the terminal portion, the depth of the engaging groove formed in the base portion of the interphase barrier of the main body case corresponding to the position of the engaging protrusion, Therefore, the thin part range of the barrier can be significantly shorter than the conventional support structure (see FIG. 6).
As a result, the bending strength of the interphase barrier is greatly improved compared to the conventional structure, and the interphase barrier is not easily cracked or damaged even when a pressing load is applied when connecting the crimp terminals of external wires. Reliability is improved. Further, by improving the bending strength, general engineering plastics can be used as the molding resin for the main body case, and the product cost can be reduced.

Embodiments of the present invention will be described below based on the examples shown in FIGS. 1 is an external perspective view of the upper frame corresponding to FIG. 6, FIG. 2 is a plan view of FIG. 1, FIGS. 3A to 3C are detailed structural views of a stationary contact, and FIG. 4 is an upper frame. FIG. 6 is a side sectional view of a state in which a fixed contact is mounted on the member, and in the drawing of the embodiment, members corresponding to those in FIG.
In the illustrated embodiment, the terminal block structure of the fixed contact 8 and the upper frame 3 of the electromagnetic contactor in which the fixed contact 8 is arranged is basically the same as the conventional structure shown in FIG. 8 and the terminal support structure of the upper frame 3 are changed as follows.
That is, in the fixed contact 8, the engagement protrusion 8c for press-fitting and fixing formed on the front end side of the terminal portion in the conventional structure is deleted, and instead, as shown in FIGS. 3 (a) to 3 (c), the terminal A cantilever-like engagement arm 8e extending linearly from the center of the portion 8-1 to the front is formed, and a spherical engagement protrusion 8e- 1 is formed. The engaging arm 8e is a part of the center of the contact support portion 8-2 that extends in a Γ shape from the terminal portion 8-1 when the fixed contact 8 is manufactured by pressing a rectangular conductor. Cut out to form. Further, at the rear end of the terminal portion 8-1 (on the side opposite to the fixed contact 8a), an engagement protrusion 8d for preventing lifting from the left and right side edges as in the conventional case, and the engagement protrusion 8d. A stopper piece 8f is projected and formed side by side.

On the other hand, with respect to the upper frame 3 of the main body case in which the fixed contact 8 is arranged, an engaging groove similar to that of the conventional structure is formed at the base of interphase barriers 3a and 3b erected on the left and right sides of the terminal base 3c. 3a-1 and 3b-1 are formed, and the depth length d thereof is matched with the position of the engaging protrusion 8d and the stopper piece 8f formed on the rear end side of the terminal portion 8-1 shown in FIG. It is formed and has a length that is significantly shorter than the depth of the groove having the conventional structure shown in FIG.
Further, a concave groove 3c-1 is formed in the center of the seat surface of the terminal pedestal 3c toward the back, and the trapezoidal portion protruding from the terminal pedestal 3c toward the back is associated with the fixed contact 8 described above. A fitting hole 3d for inserting and locking the combined arm 8e is formed. The fitting hole 3d is composed of a horizontal hole that pushes the engagement arm 8e and a vertical hole that engages with an engagement protrusion 8e-1 formed on the top surface of the front end of the engagement arm 8e at the push-down position.
When the terminal-integrated fixed contact 8 having the above-described configuration is pushed into the terminal base 3c of the upper frame 3 in the direction of the arrow in FIGS. 1 and 2, the tip of the engagement arm 8e is first inserted into the engagement hole 3d. When it pushes against the front wall, when the force is further applied, the engaging arm 8e is bent toward the concave groove 3c-1, and the engaging protrusion 8e-1 at the tip of the engaging arm scrubs through the wall, and the engaging hole portion It fits in 3d and is locked in this position. Further, when the fixed contact 8 is pushed in, an engagement protrusion 8d for preventing lifting and a stopper piece 8f formed at the rear edge of the terminal portion 8-1 at the same time are formed at the base portions of the interphase barriers 3a and 3b. The stopper pieces 8f are brought into contact with the terminal ends of the concave grooves and stopped after being fitted into the concave grooves 3a-1 and 3b-1. As a result, the fixed contact 8 has the engagement arm 8e as an anchor, the engagement protrusion 8e-1 formed at the tip of the engagement arm 8e, and the lifting prevention engagement formed at the left and right edges of the terminal portion 8-1. It is locked and fixed at a fixed position at three points with the mating protrusion 8d (see FIG. 4).

  As understood from the above description, in the structure of the illustrated embodiment, the engagement arm 8e formed at the center of the terminal portion of the fixed contact 8 is anchored to the upper frame 3 of the main body case as an anchor, and the terminal portion 8-1. An engagement protrusion 8e for preventing lifting and a stopper piece 8f formed on the rear side edge of the rear portion are fitted into engagement grooves 3a-1 and 3b-1 formed at the base portions of the interphase barriers 3a and 3b, so that the fixed contact 8 Is held in place. Therefore, the engagement concave grooves 3a-1 and 3b-1 formed in the interphase barrier need only have a shorter depth d compared to the conventional structure, and stress due to press-fitting of the engagement protrusions is applied to the thin portion. Nor. As a result, the bending strength of the interphase barriers 3a and 3b is greatly improved, and the interphase barrier is cracked or damaged by the pressing load accompanying the tightening of the crimp terminal 11 during the wiring work of connecting the electric wire to the fixed contact 8. High reliability can be secured by eliminating problems such as. In addition, the main body case can be molded from ordinary engineering plastic without using expensive reinforced plastic, and the product cost can be reduced.

FIG. 2 is a perspective view of an outer shape of a terminal support structure according to an embodiment of the present invention. Plan view of FIG. FIG. 2 is a detailed structural view of the fixed contact in FIG. 1, (a) is a plan view, (b) is a side view, and (c) is a perspective view. FIG. 1 is an enlarged side cross-sectional view showing a mounting state of the fixed contact in FIG. BRIEF DESCRIPTION OF THE DRAWINGS It is a whole block diagram of the electromagnetic contactor used as the implementation object of this invention, (a) is a sectional side view, (b) is a top view FIG. 6 is a conventional terminal support structure diagram of the electromagnetic contactor of FIG. 5, where (a) is a perspective view of an upper frame of a main body case equipped with a stationary contact, (b) is the front view, and (c) is in (b) Enlarged sectional view of part A FIG. 5 is an external perspective view showing a state in which a crimp terminal of external wiring is connected to the electromagnetic contactor shown in FIG. 5 and a terminal screw is fastened.

Explanation of symbols

DESCRIPTION OF SYMBOLS 1 Main body case of an electromagnetic contactor 3 Upper frame 3a, 3b Insulation barrier 3a-1, 3b-1 Engaging ditch 3c Terminal base 3d Engaging hole 8 Terminal integrated fixed contact 8-1 Terminal 8-2 Contact Support portion 8a Fixed contact 8b Terminal screw hole 8d Engagement projection 8e Engagement arm 8e-1 Engagement projection of engagement arm 8f Stopper piece 9 Terminal screw d Depth length of engagement groove

Claims (3)

A terminal base lined up in a horizontal row on the body case made of molded resin, and interphase barriers erected on both the left and right sides of each terminal base, and a terminal-integrated fixed contact on the terminal base A terminal device of a switch that is fixed and held, wherein the fixed contact has a structure in which a contact support portion of a fixed contact is erected and extended forward from a flat plate terminal portion in which a terminal screw is screwed.
The terminal portion of the fixed contact is provided with a tab-like engagement protrusion protruding sideways from the left and right side edges, and a cantilever-like engagement arm protruding forward from the front edge center of the terminal portion. On the case side, there are formed an engaging groove into which the engaging protrusion fits along the root part of the interphase barrier, and an engaging hole part into which the engaging arm fits into the back side of the terminal pedestal. A terminal device for a switch, wherein the engaging protrusion and the engaging arm are inserted into the engaging groove and the engaging hole of the main body case, respectively, and the fixed contact is locked and fixed at a fixed position when the terminal is mounted. . The terminal device according to claim 1, wherein the engaging protrusion of the fixed contact is formed on the side edge of the rear end opposite to the fixed contact, and the engaging arm is formed by cutting out from the contact support portion connected in front of the terminal portion. A terminal device for a switch. 3. The terminal device according to claim 1 or 2, wherein a retaining engagement protrusion is provided on an upper end of the engagement arm, and the retaining protrusion is disposed at an engagement hole of the main body case at a mounting position of the fixed contact. The terminal device of the switch characterized by being latched to the part.

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