TWI638163B - High current probe - Google Patents

Abstract

The present invention provides a high-current probe capable of maintaining stable low-resistance contact for a long period of time without strain or fatigue failure. This high-current probe is provided with a conductive contact element at a tip end portion of a basic element made of a conductive body, and the contact element includes a fixing portion which is contacted with the tip end portion of the basic element and is Fixed to the distal end portion of the basic element; and a plurality of legs protruding radially from the fixed portion, and when the contact element is pressed against the subject, the plurality of leg objects are pressed While expanding and deforming and contacting the subject, a stopper is protruded at the top end of the basic element, and when the contact element is pressed against the subject by a predetermined distance, the stopper is adjacent to the subject and restricts the object. The contact element moves in the direction of the subject.

Description

High current probe

The present invention relates to a high-current probe for measuring resistance values, voltage values, and the like.

Conventionally, an inspection probe capable of measuring an electrical resistance, a voltage, and the like by establishing an electrical connection by firmly adjoining a conductive tip portion to a subject. In particular, a probe dedicated to a large current (for example, from tens of amperes to hundreds of amperes). In order to suppress heat generation and ensure a contact area, the tip of the probe is formed to contact the subject at multiple points.

However, since the test object is used in the atmosphere, an oxide film may be formed on the surface layer of the test object. In addition, a high-resistance coating may be applied to an electrode element or the like, for example, by a chromate treatment. When the probe is pressed from a high-resistance coating such as an oxide film or a high-resistance coating formed on the surface layer of the subject in this way, the contact resistance increases, so stable contact with low resistance cannot be ensured. Therefore, it is desirable to remove or pierce the high-resistance coating and bring the tip of the probe into contact with the subject.

For example, Patent Document 1 describes a method in which a high-resistance coating is penetrated by forming the tip of a probe into a sharp multi-vertex shape, and pressing the tip of the probe against a surface layer of a subject.

However, when the tip of the probe is formed into a sharp multi-vertex shape, the tip of the probe contacts the surface layer of the subject on a virtual plane formed by connecting the sharp multi-vertexes. It is not possible to change the contact point by following the unevenness, tilt, etc. of the surface of the subject. Therefore, there is a problem that it can only correspond to a smooth surface with no slope, and the use is limited. In addition, even if there is a smooth surface without a slope, there is a problem that the contact state is unstable in the presence of small lines and the like. In addition, since it is necessary to process a plurality of vertices to an equal height, there is a problem that a high processing technique is required and the cost becomes high.

As a method for solving such a problem, Patent Document 2 proposes a method in which a plurality of contact portions that are bifurcated radially are formed on the tip of the probe, and the surface layers of the subject are removed by rubbing with the plurality of contact portions. High resistance coating. According to this method, each contact portion of the plurality of contact portions changes the contact point according to the unevenness, inclination, and the like on the surface of the subject, so that stable contact can be ensured even when the electrode has unevenness and inclination. In addition, by rubbing each contact portion against the electrode, the high-resistance coating on the electrode surface can be removed, thereby preventing an increase in contact resistance caused by the high-resistance coating, and ensuring stable low resistance. s contact. In addition, even when the electrode material to be tested is fixed and adhered to the probe tip, the fixed and adhered electrode material can be peeled off by the brushing operation, so that an increase in contact resistance can be prevented, and it is possible to ensure Low-resistance stable contact. In addition, since a punching process can be used as a method for producing a probe for high current, it can be manufactured inexpensively.

Prior art literature

Patent literature

Patent Document 1: Japanese Utility Model Publication No. 62-114366

Patent Document 2: Japanese Patent Application Laid-Open No. 2011-137791

However, since the structure described in Patent Document 2 described above is formed by elastically deforming a plurality of contact portions, Since the structure of the surface layer of the subject is brushed, there may be a problem that an unrecoverable strain remains in the contact portion, or the contact portion is fatigue-destructed. In this way, if strain or fatigue failure occurs in the contact portion, stable low-resistance contact cannot be achieved.

Therefore, a problem to be solved by the present invention is to provide a high-current probe capable of maintaining low-resistance contact for a long period of time without strain or fatigue failure.

The present invention has been made in order to solve the above problems, and has the following features.

The invention described in claim 1 is a high-current probe provided with a conductive contact element at a tip portion of a basic element composed of a conductor, wherein the contact element includes: a fixing portion: the tip of the basic element described above is fixed. There is a plate which is fixed to the top end portion of the basic element in a state in contact with the top end portion of the basic element; and a plurality of legs: which protrude radially from the fixing portion; and presses the contact element on In the case of the subject, the plurality of legs are expanded and deformed by being radially pressed by the subject and contacted with the subject, and both are arranged to be ground on the inner edges of the front ends of the plurality of legs. The structure of brushing the surface layer of the subject has a stopper protruding from the top end of the basic element, and when the contact element is pressed against the subject by a predetermined distance, the stopper is adjacent to the subject to restrict the contact element from being inspected. Body direction.

The invention described in claim 2 is based on the technical features of the invention described in claim 1, wherein the stopper is protruded near the center of the contact element.

The invention described in claim 3 is based on the technical features of the invention described in claim 1 or 2, characterized in that the stopper can be used as a voltage measuring sensor pin for four-terminal measurement.

According to the invention described in claim 1, as described above, when the contact element is pressed against the subject, a plurality of legs are pressed by the subject to expand and deform and come into contact with the subject. That is, since multiple legs follow the electrode's Deformation due to unevenness and inclination can ensure stable contact without being affected by unevenness and inclination of the electrode. In addition, the high-resistance coating on the surface of the electrode can be removed by rubbing the tip of each leg against the electrode, thereby ensuring stable contact with low resistance. In addition, even when the electrode material to which the subject is adhered is fixed to the tip of the leg, the fixed and adhered electrode material can be peeled off by a brushing operation, so that low-resistance and stable contact can be ensured. In addition, since a punching process can be used as a method for producing a probe for high current, it can be manufactured inexpensively. In addition, even if it is assumed that the contact element is abraded or deteriorated, it is only necessary to replace the contact element, so that the use cost of the high-current probe can be significantly reduced.

In addition, since a stopper protrudes from a tip end portion of the basic element, the stopper is adjacent to the subject when the contact element is pressed against the subject by a predetermined distance to restrict the movement of the contact element in the direction of the subject Therefore, the amount of deformation of the leg is limited, so that the stress generated when the leg is deformed can be within the elastic range of the leg (preferably within the fatigue limit). Accordingly, even when the probe for high current is repeatedly used, strain and fatigue damage can be suppressed, and stable low-resistance contact can be maintained for a long time.

In addition, as described in claim 2, as described above, the stopper is protruded near the center of the contact element, so that the deformation suppression exerted by the stopper can be applied to all the legs approximately equally.

In addition, as described in claim 3, as described above, the stopper can be used as a voltage measuring sensor pin for four-terminal measurement. Therefore, a high-current probe can also be used in four-terminal measurement, and accuracy can be achieved Higher measurement.

10‧‧‧ High Current Probe

11‧‧‧ Casing

12‧‧‧ force application element

13‧‧‧ plunger (basic element)

13a‧‧‧Top

13b‧‧‧through hole

13c‧‧‧Back end

14‧‧‧ contact element for circular plate

14a‧‧‧Fixed part

14b‧‧‧ round hole

14c‧‧‧leg

15‧‧‧stop

15a‧‧‧ flat surface

15b‧‧‧ protrusion

15c‧‧‧Shaft

15d‧‧‧back

16, 17‧‧‧ insulating flange

20‧‧‧Probe for high current

21‧‧‧ plate element (basic element)

21a‧‧‧Top

22‧‧‧ rectangular plate (contact element)

22a‧‧‧Fixed section

22b‧‧‧ round hole

22c‧‧‧leg

23‧‧‧stop

25‧‧‧ Four-terminal measuring probe

26‧‧‧ Needle guide

27‧‧‧ Needle force element

28‧‧‧Connecting Department

30‧‧‧Subject

FIG. 1 is an external perspective view of a high-current probe.

FIG. 2 is a perspective view of the appearance of a contact element of a circular plate.

Fig. 3 is a cross-sectional view of a high-current probe.

FIG. 4 is a partially enlarged cross-sectional view of a high-current probe.

FIG. 5 is an explanatory view showing a state in which a surface layer of a subject is brushed by a leg.

6 is a side view of a high-current probe according to a modification in which the number of legs is changed.

FIG. 7 is an external perspective view of a high-current probe using a modified example of a rectangular plate (contact element).

FIG. 8 is an external perspective view of a rectangular plate (contact element).

FIG. 9 is a cross-sectional view of a high-current probe according to a modification.

FIG. 10 is a partially enlarged cross-sectional view of a high-current probe according to a modification.

An embodiment of the present invention will be described with reference to the drawings.

The high-current probe 10 according to the present embodiment establishes an electrical connection with the subject 30 by having a conductive tip adjacent to the subject 30, and is used to measure the resistance value, voltage value, and the like of the subject 30. As shown in FIG. 1, the high-current probe 10 is in contact with the subject 30 at a plurality of points on its tip to ensure a contact area, even when used for large currents (for example, from tens of amperes to hundreds of amperes). It is also possible to suppress heat generation.

As shown in FIGS. 1 and 2, the high-current probe 10 includes a sleeve 11, a force applying element 12, a plunger 13, a contact element 14 of a circular plate, a stopper 15, and an insulating flange 16. , 17.

The sleeve 11 is a cylindrical member made of a conductor as shown in FIG. 3, and a plunger 13 is held in a hollow portion of the sleeve 11 so as to be slidable. The sleeve 11 is used, for example, by forming a hole in a plate made of synthetic resin, and fixing the sleeve 11 to a plate made of synthetic resin in a state where the sleeve 11 is inserted through the hole. So fixed with casing The plate 11 is disposed so as to be close to and away from the subject 30 (electrode) so as to face the subject 30 (electrode). When an electrical connection is to be established, the tip of the high-current probe 10 (more specifically, the contact element 14 of a circular plate described later) can be pressed against the subject 30 by bringing the board close to the subject 30. It is brought into contact with the subject 30. On the other hand, when the tip of the high-current probe 10 is to be in a state where it is not in contact with the subject 30, the high-current probe can be moved by moving the plate in a direction away from the subject 30. The tip of the probe 10 is formed in a state where it is not in contact with the subject 30.

The urging element 12 is a spring element for urging a plunger 13 described later, and the urging element 12 urges the plunger 13 in a direction protruding from the sleeve 11. By providing the urging element 12, when the tip of the plunger 13 is pressed against the subject 30, a stable contact can be ensured by the rebound force of the urging element 12.

The plunger 13 (basic element) is made of a conductor, and penetrates the sleeve 11 as shown in FIG. 3 and is held in the sleeve 11 so as to be able to move forward and backward. The plunger 13 can be connected to an electric wire at the rear end portion 13 c, and can be electrically connected to a measurement device (not shown) by an electric wire. A contact element 14 of a circular plate for conducting electricity, which will be described later, is fixed to the distal end portion 13 a of the plunger 13. The plunger 13 is a hollow element shown in FIG. 3 and has a through hole 13 b formed therethrough in the longitudinal direction.

The contact element 14 of the circular plate is composed of a conductive body, and is fixed to the distal end portion 13 a of the plunger 13 in a state in contact with the distal end portion 13 a of the plunger 13 as shown in FIG. 1 and the like. Specifically, the contact element 14 of the circular plate is fixed to the front end surface of the plunger 13 by being sandwiched between the insulating flange 16 and the plunger 13 described later. The contact element 14 of this circular plate can be manufactured by processing, for example, a beryllium copper alloy. In addition, the rigidity of the contact element 14 of the circular plate may be increased by aging treatment to improve durability. In addition, the durability and electrical conductivity of the contact element 14 of the circular plate can also be improved by plating nickel gold.

As shown in FIG. 2, the contact element 14 of the circular plate is formed by processing a plate into a crown shape, and is manufactured by, for example, punching and punching. The contact element 14 of the circular plate includes a circular fixed portion 14a in the center, and a plurality of leg portions 14c protruding radially from the fixed portion 14a.

The fixing portion 14 a is a portion which is fixed to the distal end portion 13 a of the plunger 13 in a state in contact with the distal end portion 13 a of the plunger 13, and is sandwiched between an insulating flange 16 and the plunger 13 described later. Ground held part. A circular hole 14b is formed in the center of the fixing portion 14a, and can pass through a shaft portion 15c of a stopper 15 described later.

The leg portion 14 c is a portion protruding from the outer peripheral edge of the fixing portion 14 a at regular intervals, and is formed to protrude obliquely outward from the direction of the fixing portion 14 a toward the subject 30. As shown in FIG. 5, when the plunger 13 is pressed against the subject 30, the leg portion 14 c is pressed by the subject 30 to expand and deform and contact the subject 30. At this time, as shown in FIG. 5, the edge of the top end of the leg portion 14 c is used to scrub the surface layer of the subject 30, and the high-resistance coating formed on the surface layer of the subject 30 can be removed.

In addition, as shown in FIG. 6, the number of the leg portions 14 c may be appropriately changed according to the magnitude of the current or the like. In addition, a plurality of circular plate contact elements 14 having different numbers of leg portions 14 c may be provided, so that the number of leg portions 14 c can be changed according to the use environment by replacing the circular plate contact elements 14.

The stopper 15 is a rod-shaped element as shown in FIG. 3. A flat surface 15 a is formed at a tip end portion of the shaft portion 15 c, and a conical protrusion 15 b is formed at a central portion of the flat surface 15 a. The stopper 15 is arranged so that the shaft portion 15 c penetrates the through hole 13 b of the plunger 13, and the flat surface 15 a formed at the tip portion protrudes in the tip direction of the plunger 13. In addition, as shown in FIG. 4, the protrusion 15 b protruding from the flat surface 15 a protrudes in the direction of the subject 30 in the same manner as the leg portion 14 c of the contact member 14 of the circular plate, but the protrusion amount of the protrusion 15 b is set to be greater than that of the leg. The amount of protrusion of the portion 14c is small (in other words, the protrusion 15b is formed so as not to protrude from a virtual plane formed by connecting the ends of the leg portions 14c).

When the plunger 13 is pressed toward the subject 30 to a predetermined distance, the stopper 15 is adjacent to the subject 30 and restricts movement of the contact element 14 in the direction of the subject 30. The stopper 15 restricts the movement of the contact element 14 so that the leg portion 14 c is prevented from being deformed without exceeding a predetermined range.

Specifically, as shown in FIG. 5, when the plunger 13 is pressed against the subject 30, the leg portion 14 c is pressed and deformed by the subject 30, and a protrusion 15 b provided at the tip of the stopper 15 is inserted. Subject 30. Furthermore, if the protrusion 15b is inserted into the subject 30 to a certain position, the plunger 13 cannot be further pressed against the subject 30. In this manner, by providing the stopper 15 so that the plunger 13 cannot be pressed against the subject 30 by the above distance, the leg portion 14c cannot be expanded and deformed beyond a predetermined range.

In addition, the stopper 15 is arranged coaxially with the plunger 13, and a vertex of the protrusion 15 b is provided on a vertical line passing through the center of gravity of the contact element 14 of the circular plate. Therefore, the deformation suppression by the stopper 15 is applied to all the leg portions 14 c almost equally. In addition, it is preferable that the suppression by the stopper 15 is set such that the maximum stress generated when the leg portion 14c is deformed is smaller than the yield point, and more preferably, the suppression by the stopper 15 is set as the leg portion 14c is deformed. The maximum stress generated at this time is less than the fatigue limit.

As shown in FIGS. 3 and 4, the insulating flanges 16 and 17 are cylindrical insulating elements fitted and fixed to the through holes 13 b of the plunger 13. In addition, the aforementioned stopper 15 is fixed to the plunger 13 by being pressed into the holes of the insulating flanges 16 and 17.

However, the stopper 15 of the present embodiment can be used as a voltage measuring sensor pin for four-terminal measurement. That is, by being fixed by the insulating flanges 16 and 17, the stopper 15 is insulated from the plunger 13 and the contact member 14 of the circular plate. In addition, an electric wire can be connected to the rear end portion 15 d of the stopper 15, and an electric wire can be electrically connected to a measurement device (not shown) for four-terminal measurement. In this way, the stopper 15 can be connected to the measuring device using a system that is electrically independent from the plunger 13 and the contact element 14 of the circular plate. In addition, since the stopper 15 has a protrusion 15b at the tip, the protrusion 15b is inserted into the subject 30, and the high-resistance coating of the surface layer of the subject 30 can be pierced, even in the case of four-terminal measurement. , Can also achieve stable low resistance contact.

As described above, according to the present embodiment, when the plunger 13 is pressed against the subject 30, the plurality of legs 14 c are pressed by the subject 30 to be expanded and deformed and come into contact with the subject 30. That is, since the plurality of legs 14c are deformed in accordance with the unevenness and inclination of the electrode, it is possible to ensure stability without being affected by the unevenness and inclination of the electrode. Fixed contact. In addition, by pressing the tip of each leg portion 14c against the electrode and brushing it, the high-resistance coating on the surface of the electrode can be removed, and low-resistance and stable contact can be ensured. In addition, even when the electrode material of the subject 30 is fixedly adhered to the tip of the leg portion 14c, the fixedly adhered electrode material can be peeled off by a brushing operation, so that low-resistance and stable contact can be ensured. In addition, since a punching process can be used as a manufacturing method, it can be manufactured inexpensively. In addition, even if it is assumed that the contact element 14 of the circular plate is worn and deteriorated, it is only necessary to replace the contact element 14 of the circular plate, so that the use cost of the high-current probe 10 can be significantly reduced.

Furthermore, since the stopper 15 protrudes from the tip portion 13a of the plunger 13, when the contact member 14 of the circular plate is pressed against the subject 30 by a predetermined distance, the stopper 15 is adjacent to the subject 30, and the leg portion 14c is suppressed. Deformation exceeds a predetermined range, so the amount of deformation of the leg portion 14c is limited, so that the stress generated when the leg portion 14c is deformed can fall within the elastic range of the leg portion 14c (preferably within the fatigue limit). Accordingly, even when the high-current probe 10 is repeatedly used, strain and fatigue damage can be suppressed, and stable low-resistance contact can be maintained for a long time.

In addition, since the stopper 15 is protruded near the center of the contact element 14 of the circular plate, the deformation suppression exerted by the stopper 15 can be applied to all of the legs 14 c approximately equally.

In addition, the stopper 15 can be used as a voltage measurement sensor pin for four-terminal measurement. Therefore, a high-current probe 10 can also be used in four-terminal measurement, and highly accurate measurement can be performed.

In the above-mentioned embodiment, an example in which the plunger 13 is used as a basic element of the high-current probe 10 has been described, but the embodiment of the present invention is not limited to this. For example, as shown in FIG. 7, the plate-like element 21 may be used as a basic element. That is, even if it is a high-current probe 20 such that an object to be measured is sandwiched between two plate-shaped elements 21, the structure of the present invention can be applied to obtain the same effect as the embodiment described above.

In the above-described embodiment, the contact element 14 using a circular plate is used as the high-current probe 10. An example of a contact element has been described, but embodiments of the present invention are not limited thereto. For example, as shown in FIGS. 7 and 8, a rectangular plate 22 may be used as the contact element. In the example shown in FIGS. 7 and 8, the rectangular plate 22 includes a rectangular fixing portion 22 a and a plurality of leg portions 22 c protruding from the outer peripheral edge of the fixing portion 22 a at substantially the same height. A circular hole 22b is formed in the center of gravity of the fixed portion 22a. By placing the stopper 23 so as to penetrate the circular hole 22 b, the stopper 23 is protruded and provided near the center of the rectangular plate 22. As described above, even when the shape of the contact element is changed, the structure of the present invention can be applied to obtain the same effect as the above-mentioned embodiment.

In addition, in the above-mentioned embodiment, the stopper 23 can be used as a voltage measuring sensor pin for four-terminal measurement, but it is not limited to this, and the four-terminal voltage measurement can be provided separately from the stopper 23 Sensing pin. For example, as shown in FIGS. 9 and 10, a four-terminal measuring probe 25 that is a voltage measuring probe for four-terminal measurement may be provided so as to penetrate the stopper 23. In the examples shown in FIG. 9 and FIG. 10, the four-terminal measurement probe 25 is disposed in the hollow portion of the cylindrical needle guide 26 and is held by the needle guide 26 so as to be able to slide back and forth. In addition, the four-terminal measurement probe 25 is urged by the needle urging element 27 so as to protrude outward, and can be slid inward by being pressed against the subject 30. A connection portion 28 for connecting to a measurement device is provided on the rear side of the needle guide portion 26. By connecting the measurement device to the connection portion 28, the four-terminal measurement probe 25 can be electrically connected to the subject 30. Perform voltage measurement. The four-terminal measuring probe 25 is insulated from the plunger 13 and the contact element 14 of the circular plate. In this way, the four-terminal voltage-sensing probe is provided so as to penetrate the plunger 13 of the high-current probe 10, and the high-current probe 10 can also be used in the four-terminal measurement. measuring.

Claims (3)

A high-current probe is provided with a conductive contact element at a tip end portion of a basic element composed of a conductive body. The contact element includes: a fixing portion: a plate is fixed at the top end of the basic element, and the base element is similar to the basic element described above. The contact state of the tip end portion of the element is fixed to the tip end portion of the basic element; and a plurality of legs: which protrude radially from the fixation portion; when the contact element is pressed against the subject, the plurality of legs When the part is expanded and deformed by the radial pressing of the subject and comes into contact with the subject, both are arranged to have the structure of grinding the surface layer of the subject at the edges inside the front ends of the plurality of legs. ; A stopper protruding from a tip end portion of the basic element, the stopper adjoining the subject when the contact element is pressed against the subject by a predetermined distance to restrict the movement of the contact element in the direction of the subject. The high-current probe according to claim 1, wherein the stopper is protruded near a center of the contact element. The high-current probe according to claim 1 or 2, wherein the stopper can be used as a voltage measurement sensing pin for four-terminal measurement.