JPH059656Y2 - - Google Patents

Description

[Detailed description of the invention] [Field of industrial application] This invention relates to a clamp-type measuring instrument, and more specifically, an opening/closing mechanism for a clamp-type measuring instrument that allows easy insertion and removal of the electrical circuit to be measured. Regarding.

[Technical background of the invention]

Clamp-type measuring instruments are widely used because they can measure the current, power, power factor, etc. flowing through the electrical circuit under test without cutting the electrical circuit in its original wiring state. This type of clamp-type measuring instrument is
As shown in FIG. 3, a case body 1 houses a measuring circuit and the like, a pair of clamp arms 2 each having one end pivotally supported by the case body 1,
It is composed of 3. Each clamp arm 2,
3 is a detection unit in which a coil is wound around a magnetically conductive core, which is mounted inside a shield case, and by pressing a knob 4 protruding from the case body 1 inward, each clamp arm 2, 3 and other parts are detected. The ends open;
An electrical circuit to be measured is inserted into this, and the electrical characteristics of this electrical circuit are measured. The other end of each clamp arm 2, 3 is finished in a mirror finish so that no air gap occurs between the clamp arm 2 and the other end when the clamp arm is closed.

[Problem that the invention attempts to solve]

On the other hand, as mentioned above, the clamp arms 2 and 3 are pressed by an elastic material such as a spring in order to prevent an air gap from occurring between the clamp arms 2 and 3 when they are closed. Requires relatively strong force when opening. There is no problem if the electrical circuit to be measured is shielded, but if it is a bare wire, the contact surface of the clamp arms 2, 3 is pressed against the bare wire while opening the clamp arms 2, 3 against the elastic force. It must be inserted without touching and must be done with extreme care.

Therefore, an object of this invention is to provide a clamp-type measuring instrument in which the contact surface of the clamp arm does not come into contact with the electrical circuit to be measured, and the electrical circuit to be measured can be easily inserted.

[Means for solving problems]

In the clamp-type measuring instrument of this invention, each other end of each clamp arm that moves toward and away from each other by pivoting has its outer peripheral edge protruding from the abutment surface of the other end, and its axis extends in the direction of approach and separation. First and second guide roller members are mounted so as to be rotatable orthogonal to each other, and the first and second guide roller members are mounted so that their outer peripheries do not contact each other. The device is characterized in that it is positioned within a clamp arm so as to sandwich the electrical circuit to be measured.

[Effect]

The first and second guide roller members are formed so that their outer peripheral edges protrude from the contact surface of each clamp arm, so when inserting the electrical circuit to be measured, the outer peripheral edges of these guide roller members It can be inserted while holding the electrical circuit to be measured while being separated from the contact surface of each clamp arm. The first and second guide roller members are rotatable in the insertion direction of the electrical circuit to be measured, and rotate so as to wrap the electrical circuit under test in the clamp arm, so that there is always a space between the first and second guide roller members. The electrical circuit to be measured can be positioned and inserted or removed by pushing or pulling back.

〔Example〕

An embodiment of this invention shown in FIGS. 1 and 2 will be described below. These drawings only show the essential parts of this invention, and since the other configurations are the same as conventional clamp-type measuring instruments, their explanations and drawings will be omitted. Components similar to those in FIG. 3 are given the same reference numerals.

First and second guide roller members 11 and 12 are attached to the open end of each clamp arm 2 and 3. As shown in FIG. The first guide roller member 11 includes first guide rollers 14 and 15 that are rotatably provided at both ends of a shaft 13 that is provided upright on both sides of the clamp arm 2 parallel to the case body 1. There is. A spacer roller 16 having an axial length slightly longer than the axial length of the first guide roller 15 is interposed between the first guide roller 15 and the side surface of the clamp arm 1 . Like the first guide roller member 11, the second guide roller member 12 is also rotatably provided at both ends of a shaft 17 that is provided upright on both sides of the clamp arm 3 parallel to the case body 1. A second guide roller 1 whose length in the direction is approximately the same as that of the first guide rollers 14 and 15.
8, 19. Second guide roller 18
A spacer roller 20 having an axial length slightly longer than the axial length of the second guide roller 19 is interposed between the side surfaces of the clamp arm 3 and the second guide roller 19 .

First and second guide rollers 14, 15, 1
8 and 19 have substantially the same diameter, and their outer peripheries are formed to protrude from the contact surfaces of the clamp arms 2 and 3. That is, the spacer roller 16,
20, their outer peripheries do not come into contact with each other, but when viewed from above, the first and second guide rollers 14, 18 and 15, 19 are positioned so as to overlap each other, respectively.

Now, the first and second
The electrical circuit to be measured is inserted between the overlapping portions of guide rollers 14 and 15 and between guide rollers 18 and 19, as shown by the arrows in FIG.
Furthermore, these guide rollers 14, 15, 18, 19
As the circuit to be measured is pressed between the clamp arms 2 and 3, guide rollers 14 and 15 rotate clockwise and guide rollers 18 and 19 counterclockwise as shown in FIG.
pull it inside. At this time, due to the hardness of the electrical circuit to be measured, the spaces between the guide rollers 14, 15 and 18, 19 are pushed apart, and as a result, the contact surfaces of the clamp arms 2, 3 are also opened. Therefore, since the electrical circuit to be measured is inserted into the clamp arms 2 and 3 while being guided by the outer peripheral edges of the guide rollers 14, 15, 18, and 19, the electrical circuit to be measured is inserted into each contact surface of the clamp arms 2 and 3. never come into contact with. By providing the clamp arms 2 and 3 with closing springs as in the past, the electric circuit to be measured is connected to the guide rollers 14, 15,
After passing through 18 and 19, the clamp arms 2 and 3
can be closed so that each abutting surface of the two abuts against each other.

In order to take out the electrical circuit to be measured from inside the clamp arms 2 and 3, the case body 1 may be pulled so that the electrical circuit to be measured passes through it as shown by arrow B in FIG. Thereby, the clamp arms 2 and 3 can be taken out from the electrical circuit to be measured by the reverse operation to that described above.

In the above embodiment, four guide rollers 14, 1
5, 18, and 19, but one guide roller 14 and 18 is provided on one side of each clamp arm 2, 3, and a spacer roller 20 is provided between guide roller 18 and clamp arm 3. Alternatively, the clamp arm 2 may be provided with only the guide roller 14 and the clamp arm 3 may be provided with only the guide roller 18.

Further, the elasticity of the closing spring may be set to be weak so that each clamp arm 2, 3 opens depending on the hardness of the electrical circuit to be measured. In this case, if the closing spring is set so that the clamp arms 2 and 3 open when a less rigid electrical circuit is inserted, the clamp arms 2 and 3 will open due to the weight of the clamp itself when the clamp is lowered into the electrical circuit to be measured. There is a possibility that the door may open, but in such a case, a locking mechanism to maintain the closed state may be provided and locked.

[Effect of idea]

As mentioned above, the clamp-type measuring instrument of this invention is
Rotatable guide rollers are provided at the opening/closing ends of the pair of clamp arms, and the outer peripheral edges of these guide rollers protrude from the contact surface of the clamp arms. It can be positioned within the clamp arm so as to clamp the . Since the electrical circuit to be measured contacts the outer peripheral edge of the guide roller and does not contact the contact surface of the clamp arm, even a bare electrical circuit to be measured can be easily inserted. Since the guide roller inserts and removes the electrical circuit to be measured while rotating, only a small amount of force is required.

[Brief explanation of the drawing]

FIG. 1 is a plan view showing only the essential parts of an embodiment of this invention, FIG. 2 is a side view of FIG. 1, and FIG. 3 is a perspective view showing a conventional clamp-type measuring instrument. In the drawing, 1 is a case body, 2 and 3 are clamp arms, 11 and 12 are first and second guide roller members, 13 and 17 are shafts, and 14, 15, 1
8 and 19 are guide rollers, and 16 and 20 are spacer rollers.

Claims (1)

[Claims for Utility Model Registration] (1) It has a pair of clamp arms with one end supported pivotably, and the surface of the other ends of these clamp arms that come into contact with each other is released, and the object to be measured is placed inside the clamp arm. In a clamp-type measuring instrument that measures the electrical characteristics of the electrical circuit to be measured by positioning the electrical circuit, each of the other ends that move toward and away from each other by pivoting of each of the clamp arms has an outer peripheral edge that is connected to the other end. first and second guide roller members are rotatably mounted so as to protrude from the abutment surface and have their axes perpendicular to the contact/separation direction; A clamp-type measuring instrument, characterized in that the measuring instrument is mounted so that its outer periphery does not come into contact with each other, and is positioned within the clamp arm so that the electrical circuit to be measured is sandwiched between the first and second guide roller members. (2) Utility model registration In claim 1, the first guide roller member is provided on one side of the clamp arm, and the second guide roller member is provided on the other side of the clamp arm opposite to the one side. A clamp-type measuring instrument characterized by being attached to each side of the (3) Utility model registration In claim 1, the first and second guide roller members are attached to the same side of the clamp arm, and the first and second guide roller members are attached to the same side of the clamp arm.
A clamp type measuring instrument characterized in that the guide roller member is provided so as to protrude from the second guide roller member via a spacer so that the outer periphery of the second guide roller member does not come into contact with the outer periphery of the second guide roller member. (4) Utility model registration In claim 1, the first and second guide roller members each include two guide rollers attached to both sides of each clamp arm, and
One guide roller of the guide roller member is attached to the second guide via a spacer so that the outer periphery of one guide roller of the second guide roller member attached to the same side surface as this guide roller does not come into contact with the outer periphery of the second guide roller. The other guide roller of the second guide roller member is provided to protrude from one guide roller of the roller member, and the other guide roller of the second guide roller member is provided with a spacer interposed therebetween so that the outer periphery of the other guide roller of the first guide roller member does not come into contact with the outer periphery of the other guide roller. A clamp type measuring instrument characterized in that the first guide roller member is provided so as to protrude from one guide roller of the first guide roller member.