JPH04126176U - Probe for resistance measurement - Google Patents

Abstract

(57) [Summary] [Purpose] The connection between the contact conductors 12, 13 and the conducting wires 27, 28 is unlikely to deteriorate, and the contact conductors 12, 13 are easy to replace. [Structure] Contact conductors 12 and 13 are held in case 11 so as to be able to move in and out from one end, and coil springs 17,
18 is interposed therebetween, and a through hole 25 formed in the fixing plate 16,
Elastic contact contacts 31 and 32 are fitted into and fixed to 26, and movable contacts 34 of these contacts 31 and 32 are brought into elastic contact with the end surfaces of contact conductors 12 and 13, respectively, by springs 35. Cylindrical body 33 of elastic contact contacts 31, 32
A current supply conductive wire 27 and a voltage measurement conductive wire 28 are soldered to the conductive wire 27 and the voltage measuring conductive wire 28, respectively.

Description

[Detailed explanation of the idea]

0001

[Industrial application field]

This idea uses, for example, through-holes in a printed wiring board to Measure the electrical resistance of wiring by passing current and detecting the generated voltage. The present invention relates to a resistance measurement probe used for four-terminal resistance measurement.

0002

[Conventional technology]

This type of resistance measurement probe was proposed in Japanese Utility Model Publication No. 48-42210. Ru. As shown in FIG. 3, this probe is inserted into the cylindrical case 11 from one end to the first, The second contact conductors 12 and 13 are movable in and out, that is, parallel to the axis of the case 11. freely held. The first and second contact conductors 12 and 13 each protrude to the outside. The tip of the cone forms one half and the other half of an elongated cone. It has a structure that is divided into two parts on the surface including the core, and an insulating film 1 is placed on the inner surfaces facing each other. 4 and 15, the first and second contact conductors 12 and 13 are insulated from each other, and They are movable relative to each other parallel to the axis.

0003 A fixing plate 16 is installed in the case 11 facing the inner end surfaces of the first and second contact conductors 12 and 13. is fixed, and a coil spring 1 is installed between the fixed plate 16 and the first and second contact conductors 12 and 13. 7 and 18 are interposed, respectively, and the first and second contact conductors 12 and 13 protrude outward. It is biased as such. The structure is formed by both the inner ends of the first and second contact conductors 12 and 13. Flams 19 and 21 are integrally formed on the outer periphery of the cylindrical part formed by the cylindrical part. , 21 are engaged with an axial step portion 22 formed on the inner surface of the case 11, and the first and second This prevents the two contact conductors 12 and 13 from coming off.

0004 The terminal portions 23 and 24 are integrally connected to the axis from the inner end surfaces of the first and second contact conductors 12 and 13. These terminal portions 23 and 24 project in parallel and are connected to a through hole 25 formed in the fixing plate 16. , 26, and the current supply conductor 27 is inserted into the protruding terminal portions 23, 24. , one end of each of the voltage measuring conductive wires 28 is soldered. These current supplies The conductor wire 27 for voltage measurement and the conductor wire 28 for voltage measurement are connected as one cord from the other end of the case 11. Externally derived.

[0005] Insert the tips of the first and second contact conductors 12 and 13 into the through holes of the printed wiring board. Connect the two contacts to the other part connected to the through hole. The resistance between these two points is determined by passing a current between the two and measuring the voltage generated between them. Measure the resistance value. In this case, the tip of the probe is conical, which is the through hole. Since it is fitted inside, it can be held stably in that position, and it does not need to be pushed in a little. By doing so, it comes into elastic contact with the through hole and makes good electrical contact.

[0006]

[Problem that the idea aims to solve]

When the first and second contact conductors 12 and 13 slide relative to the case 11 parallel to the axis, Stress is applied to the solder connecting these contact conductors 12, 13 and conductive wires 27, 28, If the contact conductors 12 and 13 are moved repeatedly, there is a risk of disconnection at the solder connection. Ta.

[0007] The first and second contact conductors are used depending on the through-hole diameter of the printed wiring board. 12, 13, and the tips of the first and second contact conductors 12, 13. Because the part is thin, it may get caught on something and bend. Requires replacement. However, the first and second contact conductors 12 and 13 and the conducting wires 27 and 28 Since the contact conductors 12 and 13 are soldered, it is difficult to replace them.

[0008]

[Means to solve the problem]

According to this invention, inside the case, facing the inner end surfaces of the first and second contact conductors, First and second resilient contact contacts are attached. First and second elastic contact each has a movable contact, and the movable contact is connected to the first and second contact conductors by a spring. is elastically contacted with the end face of the For the fixed parts of the first and second elastic contact However, a current supply lead wire and a voltage measurement lead wire are respectively connected.

[0009]

【Example】

Figure 1 shows an embodiment of this invention, and parts corresponding to those in Figure 3 are given the same reference numerals. . In this invention, the through holes 25 and 26 formed in the fixing plate 16 have first holes, respectively. , second elastic contact contacts 31 and 32 are fitted and fixed. 1st and 2nd elastic contact The contacts 31 and 32 are called hogo pins, and are parallel to the axis of the case 11. A movable contact 34 is held in a metal cylindrical body 33 so as to be movable in the axial direction. The movable contactor 34 is connected to the contact conductor 14, 15 side by a coil spring 35 inside the cylindrical body 33. biased toward Therefore, each movable contactor of the first and second elastic contact contacts 31 and 32 34 elastically contacts the inner end surfaces of the first and second contact conductors 12 and 13. In this example The fixed plate 16 also serves as a guide for the movement of the first and second contact conductors 12 and 13 in the axial direction. When the bosses 36, 36 are bent from the inner end surfaces of the first and second contact conductors 12, 13, The bosses 36, 36 are integrally protruded, and the bosses 36, 36 are loosely fitted into the through holes 25, 26.

0010 Closure of the fixed portions of the first and second elastic contact contacts 31 and 32, that is, the cylindrical body 33 Projections 37 are integrally projected from the end plate, and the current supply conductor 27 and the current supply conductor 27 are connected to these projections 37. One end of each pressure measuring conductor 28 is soldered. The case 11 has a tip 11a and a core. The tip portion 11a and the cord lead-out portion 11b are divided in the axial direction. The latter end is inserted into the former end, and the lead-out part 11b is a part in which the latter end is inserted into the former end and is opposed to each other. The inner and outer peripheral surfaces facing each other are screwed together. The end face of the code lead-out part 11b and the tip part 11a The fixing plate 16 is sandwiched between the stepped portion 38 on the inner peripheral surface of the case 11 and the fixing plate 16 is inserted into the case 11. Fixed.

[0011] According to this configuration, it is possible to make good electrical contact with the through hole as in the conventional case. I can do that. Moreover, the first and second contact conductors 12 and 13 and the first and second elastic contact contours Since the ends 31 and 32 are not connected and fixed to each other, the tip 11 of the case 11 By removing the cord lead-out portion 11b from each other, the first and second contact conductors 12, 13 can be easily removed and replaced with another contact conductor. Also the first and second contact Even if the conductors 12 and 13 are repeatedly moved relative to the case 11, the first and second elastic contacts The movable contacts 34 of the contacts 12 and 13 move in and out of the cylindrical body 33, and these Good electrical contact is maintained between the protrusion 37 and the conductive wires 27 and 28. The attached solder is not stressed and this connection will not degrade or break. There is no risk of it happening.

As shown in FIG. ₂ with _the same reference numerals attached to parts corresponding to those in FIG _. The fixing plate 16 may be held by the step portion 38 of the rear portion 11a ₂ and the end face of the cord lead-out portion 11b by screwing the rear portion 11a ₂ together. In this case, when replacing the first and second contact conductors 12, 13, it is only necessary to remove the front part 11a1 of the tip part 11a, the fixing plate ₁₆ remains fixed to the case 11, and the new contact conductor 12, 13 is replaced. 1. The second contact conductors 12 and 13 can be easily attached.

[0013] In FIGS. 1 and 2, the first and second elastic contact contacts 31 and 32 are small. Since the spring 35 is also small, it is better to provide springs 17 and 18, but The spring 35 may also function as the springs 17 and 18.

[0014]

[Effect of the idea]

As described above, according to this invention, the first and second contact conductors 12 and 13 and the conductor 2 7 and 28 without directly connecting them, the first and second elastic contact contacts are connected between them. 31 and 32, the movement of the first and second contact conductors 12 and 13 is caused by the first and second elasticity. It is absorbed by the contact contacts 31, 32, and the first and second elastic contact contacts 31, 3 2 and conductors 27 and 28, this soldering connection is There is no risk of deterioration or breakage.

[0015] The first and second contact conductors 12 and 13 and the first and second elastic contact contacts 31 and 32 are in elastic contact with each other and are not connected, so the first and second contact conductors 12,1 3 is easy to replace.

[Brief explanation of drawings]

FIG. 1 is a cross-sectional view showing an embodiment of the invention, with the upper part cut away.

FIG. 2 is a cross-sectional view showing another embodiment of the invention, with the upper part cut away.

FIG. 3 is a cross-sectional view of a conventional resistance measurement probe with the upper portion cut away.

Claims (1)

[Scope of utility model registration request] Claims: 1. A cylindrical case; a first and a second cylindrical case, which are held in the case so as to be able to enter and exit from one end of the case, have one half and the other half each having a conical tip, and are insulated from each other; A contact conductor, a movable contact that is in elastic contact with the inner end surfaces of the first and second contact conductors, and a spring that biases the movable contact toward the first and second contact conductors, respectively, is provided in the case. A resistance measurement probe comprising first and second elastic contact contacts fixed to the holder, and a current supply conductor wire and a voltage measurement conductor wire respectively connected to the fixed portions of the first and second elastic contact contacts.