VOLTAGE DETECTING PROBE AND MEASURING DEVICE

• US 20170067938A1
• Filed: 08/23/2016
• Published: 03/09/2017
• Est. Priority Date: 09/08/2015
• Status: Active Grant

• Current Assignee: Hioki Denki Kabushiki Kaisha
• Original Assignee: Hioki Denki Kabushiki Kaisha
• Inventors: KASAI, Shin
• Granted Patent: US 10,041,977 B2
• Time in Patent Office: Days
• US Class Current: 1/1
• CPC Class Codes: G01R 1/06722 Spring-loaded
• CPC Class Codes: G01R 1/06738 related to tip portion
• CPC Class Codes: G01R 1/06766 Input circuits therefor
• CPC Class Codes: G01R 1/06788 Hand-held or hand-manipulated probes, e.g. for oscilloscopes or for portable test instruments end pieces terminating in a probe H01R11/18
• CPC Class Codes: G01R 1/07 Non contact-making probes
• CPC Class Codes: G01R 1/18 Screening arrangements against electric or magnetic fields, e.g. against earth's field
• CPC Class Codes: G01R 1/30 Structural combination of electric measuring instruments with basic electronic circuits, e.g. with amplifier
• CPC Class Codes: G01R 15/06 having reactive components, e.g. capacitive transformer
• CPC Class Codes: G01R 15/12 Circuits for multi-testers , i.e. multimeters, e.g. for measuring voltage, current, or impedance at will
• CPC Class Codes: G01R 15/16 using capacitive devices
• CPC Class Codes: H01R 13/2421 using coil springs

Abstract

A voltage detecting probe includes a first shield with an insertion concave formed at a front end; a second shield that has a base end of the first shield inserted thereinto; and a detection electrode formed of a conductive cylindrical member, covered with an insulating covering, and housed inside the first shield. The first shield or detection electrode moves along an axis when an operation lever is moved. When the insulating covering on the front end contacts a measured wire inserted into the insertion concave, the detection electrode and wire become capacitively coupled. The operation lever includes a pillar portion inserted through a guide hole in the second shield and connected to the first shield or detection electrode. A third shield, which is attached to the pillar portion, moves with the operation lever, and shields the guide hole, is disposed inside and/or outside the second shield.

Claims

1. A voltage detecting probe comprising:

a first shield that is barrel-shaped, is electrically conductive and has an insertion concave, into which a measured wire is inserted, formed in a front end thereof by cutting away a part of an outer circumferential wall at the front end along a direction perpendicular to an axis;

a second shield that is barrel-shaped, is electrically conductive, and has a base end side of the first shield inserted thereinto; and

a detection electrode that is formed of a cylindrical member that is electrically conductive, whose front end surface and outer circumferential surface are covered with an insulating covering, and is housed inside the first shield,

wherein one of the first shield and the detection electrode is constructed so as to be capable of moving along a direction of the axis in keeping with a movement operation of an operation lever, and when the insulating covering on the front end surface contacts the measured wire inserted into the insertion concave, the measured wire is clamped by the insertion concave and the front end surface and the detection electrode is capable of capacitive coupling with the measured wire via the insulating covering,

the operation lever includes a knob portion and a pillar portion that is inserted through a guide hole formed in the second shield and is connected to the one of the first shield and the detection electrode, and

a third shield, which is attached to the pillar portion, is configured so as to be capable of moving in keeping with a movement operation of the operation lever, and shields the guide hole when the measured wire is clamped, is disposed at least one of inside and outside the second shield.

2. The voltage detecting probe according to claim 1,

wherein the first shield is capable of moving along a direction of the axis.

3. The voltage detecting probe according to claim 1,

wherein the third shield is disposed inside the second shield.

4. The voltage detecting probe according to claim 1,

wherein the third shield is formed in a circular barrel shape.

5. The voltage detecting probe according to claim 1,

wherein the front end-side cutaway surface positioned on the front-end side out of cutaway surfaces of the first shield portion that construct the insertion concave is inclined toward the base end side of the shield portion with a reference plane that is perpendicular to the axis as a reference.

6. The voltage detecting probe according to claim 5,

wherein a base end-side cutaway surface positioned on the base-end side out of the cutaway surfaces of the first shield portion that construct the insertion concave is more inclined toward the base end side than the front end-side cutaway surface with the reference plane as a reference.

7. The voltage detecting probe according to claim 1,

further comprising a biasing member that constantly biases the detection electrode toward the insertion concave,

wherein the detection electrode is caused to slide inside the first shield portion toward the insertion concave by a biasing force of the biasing member so that the measured wire inserted into the insertion concave is sandwiched between the front end surface and a front end-side cutaway surface positioned on a front-end side out of cutaway surfaces of the first shield portion that construct the insertion concave.

8. The voltage detecting probe according to claim 1,

wherein the front end surface is inclined toward a front end side with a reference plane that is perpendicular to the axis as a reference.

9. The voltage detecting probe according to claim 1,

wherein the outer circumferential surface of the detection electrode, which is covered with the insulating covering and is exposed from the insertion concave to an outside of the first shield in a state where the detection electrode is capacitively coupled with the measured wire, is covered by a conductor layer that electrically contacts the first shield.

10. A measuring device comprising:

the voltage detecting probe according to claim 1;

a main body that is connected to the voltage detecting probe;

a voltage detector that is disposed inside the main body, detects a voltage of the measured wire via the detection electrode, and outputs a voltage signal that changes in accordance with the voltage;

a voltage generator that is disposed inside the main body and generates a voltage that follows the voltage of the measured wire based on the voltage signal; and

a processor that is disposed inside the main body and measures the voltage of the measured wire based on the voltage generated by the voltage generator,

wherein the voltage detector operates on a floating voltage that has a potential of the voltage generated by the voltage generator as a reference.