Reed body resistance measuring clamp

Abstract

The utility model discloses a reed body resistance measuring clamp, which is characterized by comprising a positioning block, a base, a probe, a guide seat, a positioning plate and a cover plate, the positioning block is connected with the base, the base is connected with the guide seat, the probe penetrates through the guide seat and is connected with the cover plate, and the positioning plate is connected with the cover plate. The utility model provides a measuring clamp for measuring the resistance of a reed body, which can accurately and efficiently measure the resistance of the reed body and save the cost. The probe of the clamp moves up and down in the guide hole to ensure that the positions of contact points measured each time are the same and the surface of a detected part is not damaged; the same pressure can be applied from the upper part of the cover plate, so that the measurement error caused by the contact pressure is eliminated; according to the clamp, a four-terminal resistance testing method is adopted, and the measurement accuracy is higher.

Description

Technical Field

[0001] The utility model belongs to the technical field of resistance measurement, and in particular relates to a spring sheet resistance measurement fixture. Background Art

[0002] With the widespread application of relays, the size of the relay body resistance directly affects the performance of the product. The relay body resistance is the sum of the body resistances of multiple reeds, connecting rods and other parts. In order to ensure the stability of the overall performance of the relay, the body resistance of each part of the relay must be basically consistent from batch to batch.

[0003] The reeds in the relay are small in size, large in number, and difficult to measure. If you want to measure the reed body resistance with high precision, it takes a lot of time and manpower. Therefore, a measuring fixture is needed to fix the reed and measure the reed body resistance conveniently and quickly, saving time and human resources, but the prior art does not have a measuring fixture designed for reeds.

[0004] For example, a Chinese patent with publication number CN211206625U discloses a resistance measuring fixture, which includes: a housing, a macro slider, a first metal slider and a second metal slider; the macro slider, the first metal slider and the second metal slider are all arranged inside the housing; a guide ridge with a triangular cross-section is arranged on the upper side of the macro slider; a guide port is arranged on the housing, and the guide port is opposite to the edge of the guide ridge; the first metal slider and the second metal slider are respectively arranged on both sides of the guide ridge, and the first metal slider and the second metal slider can be connected to the two poles of the resistance measuring instrument respectively; the first wire and the second wire of the resistance to be measured are separated from each other under the action of the guide ridge after entering from the guide port, the first wire is clamped between the guide ridge and the first metal slider, and the second wire is clamped between the guide ridge and the second metal slider. However, the clamping force of the patent cannot be fixed, and different contact pressures may result in different resistances, and the measurement result accuracy is not high enough; it is difficult for the clamping part to be accurately in one position every time, which may cause damage to parts and components, and is not suitable for the body resistance measurement of the spring.

[0005] For example, the Chinese patent with publication number CN204439671U discloses a new type of high-voltage switch loop resistance measurement fixture, including a chuck with a U-shaped chuck and a hand-held rod, the hand-held rod is fixedly connected to the chuck in an adjustable angle, the U-shaped chuck is provided with an arc-shaped pressing piece protruding along the clamping direction, the outer end of the arc-shaped pressing piece is hinged with the chuck, and a spring for providing clamping force for the arc-shaped pressing piece is provided between the chuck and the chuck. However, the patent is a U-shaped chuck, and the clamping force is provided by a spring, which cannot accurately control the clamping force and easily causes damage to the measured parts, and is not suitable for measuring the body resistance of the spring. Utility Model Content

[0006] In order to solve the above technical problems, the utility model provides a spring body resistance measurement fixture.

[0007] The utility model is realized through the following technical solutions.

[0008] The utility model provides a spring body resistance measurement fixture, comprising a positioning block, a base, a probe, a guide seat, a positioning plate and a cover plate; the positioning block is connected to the base, the base is connected to the guide seat, the probe passes through the guide seat, the probe is connected to the cover plate, and the positioning plate is connected to the cover plate.

[0009] Preferably, the positioning block is connected to the base via screws A.

[0010] Preferably, the positioning block is connected to a power source.

[0011] Preferably, the base is connected to the guide seat via screws B.

[0012] Preferably, a guide hole is provided on the guide seat, and the probe passes through the guide hole.

[0013] Preferably, the positioning plate is provided with screws C, the cover plate is provided with screw holes, and the screws C and the screw holes are connected.

[0014] Preferably, the probe is slidably connected to the guide seat.

[0015] Preferably, a wiring hole is provided on the cover plate, and the probe is connected to the wiring hole.

[0016] The beneficial effects of the utility model are:

[0017] A measuring fixture for measuring the resistance of a reed body is provided, which can accurately and efficiently measure the resistance of the reed body and save costs; the probe of the fixture moves up and down in a guide hole to ensure that the contact point position is the same for each measurement and that the surface of the detected part is not damaged; the same pressure can be applied from above the cover plate to eliminate measurement errors caused by contact pressure; the fixture uses a 4-terminal resistance test method, which has higher measurement accuracy. BRIEF DESCRIPTION OF THE DRAWINGS

[0018] Figure 1 It is a schematic diagram of the overall structure of the measuring fixture provided by the embodiment of the utility model;

[0019] Figure 2 It is a schematic diagram of the internal structure of the measuring fixture provided by the embodiment of the utility model;

[0020] Figure 3 It is a schematic diagram of the back structure of the measuring fixture provided by the embodiment of the utility model;

[0021] Figure 4It is a circuit schematic diagram of a 2-terminal test method provided by an embodiment of the utility model;

[0022] Figure 5 It is a circuit schematic diagram of a 4-terminal testing method provided by an embodiment of the utility model.

[0023] In the figure: 1-positioning block, 2-base, 3-probe, 4-guide seat, 5-positioning plate, 6-cover plate, 7-screw A, 8-screw B, 10-screw C, 11-screw hole, 12-wiring hole. DETAILED DESCRIPTION

[0024] The technical solution of the utility model is further described below, but the scope of protection required is not limited to the description.

[0025] like Figure 1-3 As shown, a spring body resistance measuring fixture includes a positioning block 1, a base 2, a probe 3, a guide seat 4, a positioning plate 5 and a cover plate 6; the positioning block 1 is connected to the base 2, the base 2 is connected to the guide seat 4, the probe 3 passes through the guide seat 4, the probe 3 is connected to the cover plate 6, and the positioning plate 5 is connected to the cover plate 6.

[0026] The positioning block 1 is connected to the base 2 by screws A7. The size of the positioning part is determined according to the size of the reed. If the reed is flat, the positioning part is processed into a step shape; if the reed is round, the positioning part is processed into a V shape.

[0027] In this embodiment, there are two positioning blocks 1, and the positioning portion is stepped to measure the flat reed.

[0028] The positioning block 1 is connected to a power source.

[0029] The positioning block 1 is connected to the power supply through screw A7 to energize the part under test, so that the 4-terminal test method can be realized.

[0030] The body resistance of the relay has a crucial impact on the performance of the relay, and the reed in the relay is relatively small, about 5mm×0.7mm×0.1mm. When measuring the reed resistance with high precision, the wiring resistance connecting the measuring instrument and the probe, and the contact resistance between the probe and the object being measured become the biggest obstacles. The wiring resistance varies greatly depending on the thickness or length, and the contact resistance is greatly affected by the wear of the probe, the contact pressure, or the measured current. Even in a good contact state, it is several mΩ, and sometimes even several Ω.

[0031] like Figure 4As shown in the figure, when using 2-terminal measurement, current I flows into the measured resistance R0 and the wiring resistances r1 and r2. Therefore, the voltage to be measured is obtained by E = Ir1 + R0 + r2, which is a value including the wiring resistances r1 and r2. The conductor resistance of the test lead itself will be added to the resistance of the object being measured, causing errors.

[0032] Therefore, in order to reliably and accurately measure the resistance of the reed, the 4-terminal test method is used.

[0033] like Figure 5 As shown in the figure, the 4-terminal measurement adopts a structure with a current source terminal for supplying constant current and a voltage detection terminal for detecting voltage drop. Since the input impedance of the voltmeter is high, almost no current flows through the wire on the voltage detection terminal side connected to the object to be measured, so accurate measurement can be performed without being affected by test lead resistance or contact resistance.

[0034] The current I flows from r2 through the measured resistor R0 into r1. Since the input resistance of the voltmeter is large, the current does not flow into r3 and r4. In this way, the voltage drop of r3 and r4 is 0. The voltage E to be measured is equal to the voltage drop E0 across the measured resistor R0. Therefore, the resistance measurement will not be affected by r1 to r4.

[0035] The base 2 is connected to the guide seat 4 by screws B8. The guide seat 4 is connected by screws B8 to ensure that the guide seat 4 is stable and does not shake.

[0036] The guide seat 4 is provided with a guide hole, and the probe 3 passes through the guide hole.

[0037] The probe 3 passes through the guide hole and can accurately contact the measured point of the measured part to accurately measure the resistance of the measured part.

[0038] The probe 3 moves up and down in the guide hole to ensure that the contact point position is the same for each measurement and to ensure that the surface of the tested part is not damaged.

[0039] The positioning plate 5 is provided with a screw C10 , and the cover plate 6 is provided with a screw hole 11 , and the screw C10 and the screw hole 11 are connected.

[0040] The positioning plate 5 is used to position the cover plate 6. A weight is added to the cover plate 6 to apply pressure. The cover plate 6 contacts the probe 3, and pressure is applied to the probe 3. The probe 3 contacts the measured part downward.

[0041] Therefore, by applying the same pressure to the cover plate 6, the measurement error caused by the contact pressure can be eliminated.

[0042] The positioning plate 5 is also used to limit the position of the probe 3 so that the probe 3 does not drop too much to cause damage to parts and cannot be easily offset.

[0043] The cover plate 6 is provided with a wiring hole 12 , and the probe 3 is connected to the wiring hole 12 .

[0044] The wiring hole is used to connect the voltmeter to the probe 3 . Remove the probe tip of the voltmeter and weld the connecting wire to the probe 3 .

[0045] The probe 3 and the guide seat 4 are slidably connected.

[0046] The probe 3 moves up and down in the guide hole to ensure that the contact point position is the same for each measurement and to ensure that the surface of the tested part is not damaged.

[0047] The utility model provides a measuring fixture for measuring the resistance of a spring body, which can accurately and efficiently measure the resistance of the spring body and save costs; the probe of the fixture moves up and down in a guide hole, ensuring that the contact point position of each measurement is the same and that the surface of the detected part is not damaged; the same pressure can be applied from above the cover plate to eliminate measurement errors caused by contact pressure; the fixture uses a 4-terminal resistance test method, and the measurement accuracy is higher.

Claims

1. A spring body resistance measurement fixture, characterized in that: The invention comprises a positioning block (1), a base (2), a probe (3), a guide seat (4), a positioning plate (5) and a cover plate (6); the positioning block (1) is connected to the base (2), the base (2) is connected to the guide seat (4), the probe (3) passes through the guide seat (4), the probe (3) is connected to the cover plate (6), and the positioning plate (5) is connected to the cover plate (6).

2. A reed body resistance measurement fixture as claimed in claim 1, characterized in that: The positioning block (1) is connected to the base (2) via screws A (7).

3. A reed body resistance measurement fixture as claimed in claim 1, characterized in that: The positioning block (1) is connected to a power source.

4. A reed body resistance measurement fixture as claimed in claim 1, characterized in that: The base (2) is connected to the guide seat (4) via screws B (8).

5. A reed body resistance measurement fixture as claimed in claim 1, characterized in that: The guide seat (4) is provided with a guide hole, and the probe (3) passes through the guide hole.

6. A reed body resistance measurement fixture as claimed in claim 1, characterized in that: The positioning plate (5) is provided with a screw C (10), and the cover plate (6) is provided with a screw hole (11), and the screw C (10) and the screw hole (11) are connected.

7. A reed body resistance measurement fixture as claimed in claim 1, characterized in that: The probe (3) is slidably connected to the guide seat (4).

8. A reed body resistance measurement fixture as claimed in claim 1, characterized in that: The cover plate (6) is provided with a wiring hole (12), and the probe (3) is connected to the wiring hole (12).

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