JP2546848Y2 - Clamp type ammeter - Google Patents

Description

DETAILED DESCRIPTION OF THE INVENTION [Industrial application field] The present invention relates to a clamp-type ammeter, and more specifically, comprises a pair of casings each having a separate clamp sensor unit, and a live wire. BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a clamp-type ammeter capable of easily performing stable holding and release of an externally-packed state when the electric-wire to be measured is introduced into a clamp sensor unit for external measurement in order to measure the state.

[Prior Art] A clamp-type ammeter is usually provided in a holder capable of opening and closing a clamp sensor unit having a pair of dividable magnetic cores and a magnetoelectric conversion unit such as a magnetoelectric conversion element. It is formed so as to be accommodated, and when the electric wire to be measured is encased in a live state, the magnetic flux induced in the magnetic core can be converted into a current by the magnetoelectric conversion means and measured. . By the way, in this type of clamp-type ammeter, how to make the magnetic cores closely contact each other without creating a gap between the butt end faces of the magnetic core is an important issue because of its relationship with magnetic resistance, which greatly affects measurement accuracy. Has become.

FIG. 4 and FIG. 5 show an example of the structure of a clamp sensor portion conventionally taken to address such a problem.

Among them, the structure shown in FIG. 4 has a structure in which a pair of core holders 1 and 2 can be opened from both sides with the support shafts 3 and 4 as fulcrums.
The butt end faces of the magnetic cores 8 and 9 are stably brought into close contact with each other by forcibly bringing the core holders 1 and 2 into an automatically closed state by a pressing force of a coil spring 7 interposed between the magnetic cores 8 and 9. It can be made to be.

In the structure shown in FIG. 5, when the core holders 1 and 2 are closed, the magnetic cores should be kept in a closed state in order to stabilize the contact state between the butted end faces. The core holder 1 on one side has a locking arm 12 driven by an operation piece 11 on the top surface thereof, and the top surface of the core holder 2 on the other side. The protrusions 13 are formed by arranging the projecting pieces 13 for hanging the hanging arms 12 respectively.

[Problem to be Solved by the Invention] However, among the above conventional examples, the one shown in FIG. 4 has a double-opening structure that opens and closes via a coil spring 7 while using the support shafts 3 and 4 as fulcrums. Fastening means 10 as shown in FIG.
Is not necessarily sufficient to keep the butted end faces of the magnetic cores 8 and 9 stably close together, leaving room for instability in measurement accuracy. It was something to leave.

Further, the one shown in FIG. 5 can solve the instability as seen in the conventional example of FIG. 5 for a time, but it is complicated in terms of operability and leaves room for improvement. Was to leave.

The object of the present invention is to provide a clamp-type ammeter with excellent operability, which can ensure that the butting end faces of the magnetic cores come into close contact with each other and release the contact with one touch, in view of the above-mentioned problems of the conventional structure. To provide.

[Means for Solving the Problems] The present invention has been made to achieve the above-mentioned object, and its structural feature is that a clamp sensor portion divided so as to be capable of forming a substantially annular magnetic circuit is provided. A pair of casings housed separately on the front end side are pivotally supported so as to be openable and closable via a support shaft arranged on the base end side, and the casing on one side is connected via a distal end thereof. A movable locking portion including a locking piece that urges the pressing force to the side of the casing and a lever portion for release operation is provided, and the clamp sensor portion is pressed against the opening and closing surface in the direction of the opening and closing surface. A spring member capable of applying a restoring force is provided, and at the tip of the casing on the other side, the engaging surface of the engaging piece of the casing on one side when the casing is closed and the spring material Engagement with an engaging surface that automatically engages under restoring force By disposing a part with a gap left between the engaging piece and the engaging piece at the time of engagement, when the casing on one side is pushed down with the gap as a limit against the restoring force of the spring material, In that the hooked state with the casing on the side can be released by one touch.

[Operation] For this reason, according to the present invention, the pair of casings supported by the support shaft provided on the base end portion side is divided and formed by bringing the tip end portions into contact with each other. The magnetic cores constituting the clamp sensor section can be brought into close contact with each other via the abutting end faces to form a substantially annular magnetic circuit. In this case, since the spring member is interposed between the clamp sensor portion on one side and the casing in which the clamp sensor portion is housed, the pressing force is constantly urged toward the contact surface that is the opening / closing surface thereof. Therefore, the magnetic core can be pressed against the clamp sensor on the other side, and the butted end faces of the magnetic core can be kept in close contact with each other. Moreover, since the movable hook provided at the tip of the casing on one side urges the pressing piece toward the casing against the hook piece, the movable hook is provided on the casing on the other side. Automatically engaging the engaging surface of the engaged portion with the engaging surface of the engaging piece through the engaging surface of the engaging piece, and obtaining a secure engaging state by the action of the restoring force of the spring material. A preferable substantially annular magnetic circuit can be formed. In addition, the above-mentioned engaging relationship between the engaging piece of the movable engaging portion and the engaged portion is such that an air gap is left between the engaging portion and the engaged portion, so that the clamp sensor accommodating portion in the casing is vertically moved. By pressing the movable latch part with one touch while pressing from both directions, the movable latch part can be immediately released and the operability can be improved.

Embodiment An embodiment of the present invention will be described below in detail with reference to the drawings.

FIG. 1 is a longitudinal sectional view showing one embodiment of a clamp-type ammeter according to the present invention, and a pair of casings 21 and 22 formed by using an appropriate material such as an insulative plastic molded product is shown in FIG. , Which are rotatably openable and closable via a support shaft 37 disposed on the base end side thereof, and are substantially annular when closed at the front end side, and have a substantially square shape according to the illustrated example. The magnetic core 2 divided and formed to enable the formation of a magnetic circuit
Clamp sensor sections 23 and 24 each having 5, 26 are separately provided.

Of these, a movable hooking portion 27 having a hooking piece 29 that urges a pressing force toward the casing 21 through the front end portion of the casing 21 on one side thereof is provided with a support shaft 31. Is pivoted through. Also, the casing 21 on one side
A spring member 38 such as a leaf spring that enables the clamp sensor 23 to be pressed toward the open / close surface is interposed between the clamp sensor 23 and the clamp sensor 23 accommodated therein. ing.

On the other hand, the casing 22 on the other side is provided with a hooked portion 35 which is formed so as to be able to automatically engage with the hooking piece 29 of the casing 21 on the one side when the casing 22 is closed by interposing the tip portion thereof. ing.

FIG. 2 and FIG. 3 are enlarged views of a main portion for clarifying the engaging relationship between the movable engaging portion 27 and the engaged portion 35 in FIG.

According to this, the movable hook portion 27 is rotatably supported by the front end side of the casing 21 on one side via the support shaft 31. In addition, a coil spring 32 having a substantially V-shape is interposed and supported on the support shaft 31 via a winding portion 34, and one leg portion 33 is provided on the side of the movable hook portion 27 and the other leg portion is provided on the other side. Side legs
33 are respectively supported on the casing 21 side, so that the lever portion 28 located on the base end side of the movable hook portion 27 is provided.
Are constantly urged in the expanding direction as shown in FIG. 2, and as a result, a latching piece located on the distal end side of the movable latching portion 27
A pressing force is applied to 29 toward the hooked portion 35 attached to the casing 22 on the other side.

In addition, the movable hooking portion 27 pivotally supported by the casing 21 on one side has a hooking piece 29 located on the tip end side of the movable hooking portion 27 having a flat engaging surface 30 and is attached to the casing 22 on the other side. It is formed so as to be freely engaged with a flat engaging surface 36 provided in the engaged portion 35. In addition, the movable hook 27 and the hook
As shown in FIG. 2, one side of the casing 21 is restored to the spring material 38 between the protruding end of the retaining piece 29 and the other casing 22 in the vertical direction when 35 is engaged. When pressed down against the force, the locking piece 29 also forms a clearance t that can be driven downward.

Although not shown, each of the magnetic cores 25 and 26 housed separately in the pair of casings 21 and 22 via the shield cases 39 and 40 is positioned at a predetermined position by a casting resin material such as epoxy resin. It is fixed to. In addition, the shield case located on the other side, the lower side according to the illustrated example.
The magnetic core 26 accommodated in 40 has a coil disposed via a vertical portion 41, and is temporarily fixed to a base material 42 and then fixed to a shield case 40 with a casting resin material.

Since this device is configured as described above,
At the time of its use, the casings 21 and 22 are
Can be opened, so that the casing 2
Clamp sensor parts 23, 24 housed separately in 1, 22
In the magnetic cores 25 and 26, the electric wire to be measured in a live state can be introduced. After the electric wires to be measured are introduced, the electric wires to be measured can be enveloped by the clamp sensors 23 and 24 including the magnetic cores 25 and 26 by closing the casings 21 and 22. Moreover, the closed state in this case is
Since a spring member 38 is interposed between the casing 21 on one side and the clamp sensor portion 23 accommodated in the casing 21, the pressing force in the direction of the contact surface as the opening / closing surface is always reduced. It can be urged, so that it can be pressed against the clamp sensor section 24 housed in the casing 22 on the other side, and the butted end faces of the magnetic cores 25 and 26 can be kept in close contact with each other. .

A movable hook 27 attached to the distal end of the casing 21 on one side is provided with a lever portion 28 and a casing 21 located at the base end thereof by a coil spring 32 having a substantially V-shape interposed therebetween. Are biased in the expanding direction, so that a pressing force can be urged toward the other casing 22 side around the support shaft 31 with respect to the engaging piece 29 located on the distal end side. it can.

Therefore, the movable locking portion 27 to which the pressing force directed toward the casing 22 on the other side is applied simply presses down the casing 21 on one side, and the locking surface 30 provided on the locking piece 29 is moved to the other side. Automatically engaged with the engaging surface 36 of the engaged portion 35 attached to the side casing 22,
These can be hung from each other.

Moreover, in this case, the spring member is provided between the casing 21 on one side and the clamp sensor portion 23 accommodated in the casing 21.
38 is interposed, and a gap t is previously formed between the top end of the hook piece 29 and the other casing 22 in the vertical direction. When the housing portions of the clamp sensor portions 23 and 24 are pressed from above and below, the casing 21 can be relatively pushed down with the gap t as a limit against the restoring force of the spring member 38, so that the locking piece 29 Can be hooked more smoothly with one touch to the hooked portion 35.

Further, after the latching in this manner, the casing 21 on one side is relatively pushed up by the restoring force of the spring member 38, so that the latching state between the two can be made more reliable. .

In addition, the clamp sensor portion 23 in the casing 21 on one side is always pressed by the spring member 38 in the direction of the abutting surface as its opening / closing surface.
Are always pressed against each other, and a preferable magnetic circuit with low magnetic resistance can be formed.

In addition, release of the engagement between the movable hooking portion 27 and the hooked portion 35 is achieved by pushing down the casing 21 on one side in the direction of the casing 22 on the other side while limiting the gap t as shown in FIG. By pressing the lever portion 28 of the movable hook portion 27 downward as shown, the hook piece 29 at the distal end thereof can be detached from the hook portion 35, so that the casing 21, 22 can be opened with a single touch, and the outer packaging state for the measured wire can be released.

[Effects of the Invention] As described above, according to the present invention, the pair of casings abut the tip ends of the casings with each other, so that the magnetic cores constituting the separately formed clamp sensor unit are formed. A substantially annular magnetic circuit can be formed in close contact with each other via the butted end faces. In this case, since the spring member is interposed between the clamp sensor portion on one side and the casing in which the clamp sensor portion is housed, the pressing force is constantly urged toward the contact surface that is the opening / closing surface thereof. Therefore, the magnetic core can be pressed against the clamp sensor on the other side, and the butted end faces of the magnetic core can be kept in close contact with each other. In addition, since the movable hook provided at the tip of the casing on one side urges the pressing piece toward the casing against the hook,
The engaging surface of the engaging piece is automatically engaged with the engaging surface of the engaged portion provided on the other side of the casing, and a reliable engaging state is provided by the action of the restoring force of the spring material. It can be obtained very easily by one-touch operation, and a stable and preferable substantially annular magnetic circuit can be formed.
Further, the engaging relationship between the engaging piece of the movable engaging portion and the engaged portion may be such that a gap t is left between the engaging portion and the engaged portion when the engaging portion is engaged. It can be released immediately by one-touch operation with one hand, pressing the lever of the movable hook with the same hand while pressing with one hand from one side or from both directions. Can be kept in a free state, and a clamp-type ammeter excellent in safety and operability can be provided.

[Brief description of the drawings]

FIG. 1 is a longitudinal sectional view showing an embodiment of the present invention. 2 and 3 are enlarged cross-sectional views of a main part showing a hooking relationship between a movable supporting portion and a hooked portion in FIG. 1, and FIGS. 4 and 5 show a conventional example. It is a principal part front view. 21,22 …… Casing, 23,24 …… Clamp sensor part, 2
5, 26: magnetic core, 27: movable locking part, 28: lever part, 29: locking piece, 30: locking surface, 31: support shaft, 32 ...
Coil spring, 33 ... leg, 34 ... winding part, 35 ... hooked part, 36 ... hooking surface, 37 ... spindle, 38 ... spring material, 39, 40
…… Shield case, 41 …… Vertical part, 42 …… Base material

Continuation of the front page (56) References Japanese Utility Model Sho 54-174817 (JP, U) Japanese Utility Model Sho 54-103472 (JP, U) Japanese Utility Model Sho 51-789 (JP, Y2)

Claims (1)

(57) [Scope of request for utility model registration] A pair of casings, each of which separately accommodates a clamp sensor portion at a front end portion thereof so as to be capable of forming a substantially annular magnetic circuit, via a support shaft disposed at a base end portion. The casing on one side is provided with a latching piece that urges the pressing force to the side of the casing via a tip portion thereof and a lever portion for releasing operation. And a spring material that enables the clamp sensor to be pressed in the direction of the opening and closing surface and to apply a restoring force to the clamp sensor. The latching portion having a latching surface having a latching surface of the latching piece of the casing on one side and a latching surface automatically latching under the restoring force of a spring material when the latching portion is closed. By leaving a gap between and
A clamp type, wherein when one of the casings is pushed down with a gap as a limit against the restoring force of the spring material, the engaged state with the other casing can be released by one-touch. Ammeter.