JPH069435Y2 - Dial cover for thermal overload relay - Google Patents

Description

[Detailed Description of the Invention] [Industrial field of application] The present invention relates to a thermal overload relay that detects an overcurrent flowing in a main circuit, and protects a current adjustment dial that sets the value of the overcurrent to be detected. Regarding dial cover.

[Conventional technology]

A conventional device of this type is shown in FIG. 5, in which 1 is a thermal overload relay and 10 is a dial cover. The thermal overload relay 1 detects an overcurrent flowing in the main circuit by a bimetal (not shown) and a resistance wire, and when the overcurrent exceeds a value set by the current adjusting dial 2, the bimetal is bent to operate the contact portion. Then, the overcurrent detection signal is output. When the contact that has been operated once is to be restored, the reset bar 3 is pushed in, and when the cooling of the bimetal is completed, the contact part returns to the original state. The current adjusting dial 2 is provided with a cross hole in its head, and a tool such as a screwdriver is engaged in the cross hole to rotate the cross hole to set the value of the overcurrent to be detected. To protect the current adjusting dial 2, a dial cover 10 made of transparent plastic is attached to the thermal overload relay 1.
The dial cover 10 is formed in a U shape, and an engaging protrusion 10a that engages with the engaging recess 1a of the thermal overload relay 1 is formed inside both legs of the dial cover 10, and the bridge portions of both legs are reset. A square hole 10b through which the rod 3 penetrates is formed. To attach the dial cover 10 to the thermal overload relay 1, push both legs of the dial cover 10 along the side wall of the thermal overload relay 1 until the engaging protrusion 10a fits into the engaging recess 1a. Performed by. Thermal overload relay 1
A groove 1b having a depth equal to the thickness of the leg of the dial cover 10 is formed on the dial cover 10.
The lateral slippage of is prevented.

[Problems to be solved by the device]

The dial cover 10 in the above-mentioned conventional device can be removed from the thermal overload relay 1 using a tool, but the removal must be performed by pushing open the free end sides of both leg pieces of the dial cover 10. For this reason, a tool such as a screwdriver must be inserted from the bottom side of the thermal overload relay 1 in the direction indicated by the arrow P. Generally, the thermal overload relay is stored in the control panel in combination with the electromagnetic contactor. It has the drawback that it is difficult to remove. For this reason, when the dial cover 10 is removed to change the current value, the dial cover 10 may be forcibly operated and the leg pieces of the dial cover may be broken.

Therefore, the object of the present invention is to eliminate the above-mentioned drawbacks of the conventional device,
An object of the present invention is to provide a dial cover for a thermal overload relay that protects the current adjusting dial and can easily change the current adjusting dial.

[Means for Solving the Problems]

For this purpose, according to the present invention, a dial cover is detachably attached to the thermal overload relay to set a value of an overcurrent flowing in a main circuit arranged above the thermal overload relay. In this case, a hole for operating the adjustment dial is formed at a position facing the adjustment dial of the dial cover, and a collar portion and a hooking protrusion are formed by sandwiching the cylindrical portion that closely adheres to the hole of the dial cover. It is achieved by fitting the dial lock member thus formed into the hole of the dial cover.

[Action]

A hole for operating the current adjustment dial is formed at a position facing the current adjustment dial of the dial cover mounted on the thermal overload relay, and the current adjustment dial is protected by attaching a dial lock member to this hole. Is
The current adjusting dial can be operated by removing the dial lock member.

〔Example〕

An embodiment of the present invention will be described below in detail with reference to the drawings. 1 and 2 show an embodiment of the present invention, in which the thermal overload relay is omitted since it is the same as that shown in FIG.

In FIG. 1, the dial cover is again indicated by 10 and a square hole 10b through which a reset rod (see FIG. 3) penetrates in the bridge portion of both leg pieces of the dial cover 10 and a current adjusting dial (see FIG. 3). A hole 10c having a size such that a tool such as a screwdriver can be inserted is formed in the cross hole of the current adjusting dial at a position facing the above. The dial cover 10 is mounted on the thermal overload relay as in the conventional example shown in FIG. A dial lock member 20 is attached to the hole 10c of the dial cover 10. The dial lock member 20 is made of a transparent plastic material, and is formed with a collar 20b and a hooking protrusion 20c sandwiching a cylindrical portion 20a that is in close contact with the hole 10c.

Hole 10 of dial cover 10 of dial lock member 20
For the attachment to c, the hook 2 of the dial lock member 20
The dial lock member 20 is inclined as shown in FIG. 3 (a) with the 0c side facing the hole 10c, and one of the hooking projections 20c (see FIG. 2) provided at 90 ° intervals is pushed into the hole 10c. .
When the dial lock member 20 is rotated in this state, the hooking protrusions 20c successively enter into the holes 10c, and FIG.
The dial lock member 20 is attached to the dial cover 10 as shown in FIG. The dial lock member 20 can be removed by inserting a tool such as a screwdriver between the collar 20b and the dial cover 10 shown in FIG.
Since c is elastically deformed and comes off the hole 10c, it can be easily removed.

Next, FIG. 4 shows a different embodiment of the present invention. The difference between this embodiment and the above-mentioned embodiment is that the collar 21b of the dial lock member 21 is formed as a convex lens. 21c is the same. By thus forming the flange 21b of the dial lock member 21 as a convex lens, the numerical value of the scale plate of the current adjusting dial can be enlarged, and the set current value can be easily confirmed.

[Effect of device]

As described above, according to the present invention, the dial lock member is detachably attached to the hole for operating the current adjusting dial formed in the dial cover, so that the setting value of the current adjusting dial can be changed without removing the dial cover. In this case, the diamond lock member is located on the upper surface side of the thermal overload relay, that is, on the front side of the operator when the thermal overload relay is installed in the control panel, so that it can be easily removed and installed. Can be done
Further, if the dial lock member is made of a transparent material, the dial cover can be made of an opaque material, so that the cost can be reduced.

[Brief description of drawings]

1 and 2 each show an embodiment of the present invention. FIG. 1 is an exploded side view of essential parts, FIG. 2 is a bottom view of a dial lock member, and FIGS. 3 (a) and 3 (b) are respectively. FIG. 4 is a side view of the dial lock member showing the different embodiment of the present invention. FIG. 5 is a perspective view of a main part of a thermal overload relay showing a conventional example. 10: dial cover, 10c: hole, 20, 21: dial lock member, 20a: cylindrical portion, 20b, 21b: collar, 20c: hooking protrusion.

Claims (1)

[Scope of utility model registration request] 1. A current control dial for setting a value of an overcurrent flowing through a main circuit arranged above a thermal overload relay is covered with a dial cover which is detachably attached to the thermal overload relay. The dial lock has a hole for allowing the adjustment dial to be operated at a position facing the adjustment dial of the dial cover, and a flange and a hooking protrusion are formed by sandwiching a cylindrical portion that closely adheres to the hole of the dial cover. A dial cover for a thermal overload relay, wherein a member is fitted in the hole of the dial cover.