High-precision current measuring device with anti-creeping structure

Abstract

The invention relates to the technical field of current measurement, and discloses a high-precision current measurement device with an anti-creeping structure. An electrical connection line; the electric connecting wire comprises a cable, a first connecting terminal connected to one end of the cable, a one-way air pumping mechanism connected to the other end of the cable, a second connecting terminal connected to the other end of the one-way air pumping mechanism and an internal expansion type limiting mechanism, and the second connecting terminal is sleeved with the internal expansion type limiting mechanism. According to the invention, the plugging terminal which is only provided with the end electrical connection area and is matched with the electrical instrument is adopted, so that the resistance of the plugging terminal when the plugging terminal is inserted into the electrical instrument can be effectively reduced, the situation that a tester manually holds the electrical instrument is avoided, and the electrical instrument can be conveniently tested after the plugging terminal is inserted into the electrical instrument. The plugging terminal is limited and fixed in the corresponding electrical jack of the electrical instrument through the one-way air pumping mechanism and the internal expansion type limiting mechanism which are matched with the plugging terminal, so that the safety of electrical connection is improved under the condition that the connection stability is ensured.

Description

Technical Field

[0001] The present invention relates to the technical field of current measurement, and more particularly to a high-precision current measuring device with an anti-leakage structure. Background Art

[0002] An ammeter is an instrument used to measure the current in AC and DC circuits. It is made based on the magnetic field force on a conductor carrying current in a magnetic field. There is a permanent magnet inside the ammeter, which generates a magnetic field between the poles. There is a coil in the magnetic field, and there is a hairspring spring at each end of the coil. Each spring is connected to a terminal of the ammeter. A rotating shaft connects the spring and the coil. At the front end of the rotating shaft relative to the ammeter, there is a pointer. When current passes through, the current passes through the magnetic field along the spring and the rotating shaft. The current cuts the magnetic flux lines, so the coil is deflected by the magnetic field force, driving the rotating shaft and the pointer to deflect. Since the magnitude of the magnetic field force increases with the increase of current, the magnitude of the current can be observed by the degree of deflection of the pointer.

[0003] Ammeters are often used in some electrical testing processes. During the test, the connecting end of the ammeter needs to be inserted into the corresponding electrical instrument. Currently, the connecting wires used by common ammeters are mostly matched with the corresponding electrical instruments. However, when plugging and unplugging, manual support of the electrical instrument is required to match the plug to be inserted into the electrical instrument. However, this method may cause electric shock to the tester once there is local leakage in the electrical instrument, which is less safe. Summary of the invention

[0004] The object of the present invention is to provide a high-precision current measuring device with an anti-leakage structure in order to solve the above-mentioned problem.

[0005] The present invention provides a high-precision current measuring device with an anti-leakage structure, comprising:

[0006] An ammeter, used to obtain current data of the instrument under test;

[0007] An electrical connection line, the electrical connection line is used to electrically connect the ammeter to the instrument to be tested;

[0008] The electrical connection line includes a cable, a connection terminal 1 connected to one end of the cable, a one-way air pumping mechanism connected to the other end of the cable, and a connection terminal 2 and an inner expansion limit mechanism connected to the other end of the one-way air pumping mechanism, wherein the inner expansion limit mechanism is sleeved on the outside of the connection terminal 2, and the cable is electrically connected to the connection terminal 2;

[0009] When the connecting terminal 2 and the internal expansion limit mechanism are both inserted into the socket of the instrument to be tested, the one-way air pumping mechanism is used to pump a set amount of gas into the internal expansion limit mechanism. When the air pressure in the internal expansion limit mechanism reaches a set value, the internal expansion limit mechanism contacts the inner wall of the socket of the instrument to be tested and applies a set value of pressure to it.

[0010] As a further optimization scheme of the present invention, the one-way air pumping mechanism includes a sealed air pumping assembly and a one-way air guide assembly 1 arranged at one end of the sealed air pumping assembly, and the internal space of the sealed air pumping assembly is connected to the outside world through the one-way air guide assembly 1.

[0011] As a further optimization scheme of the present invention, the sealed pump air component includes a connecting plate 1 connected to the other end of the cable, a hollow wire tube connected to the middle of the other end of the connecting plate 1, a connecting plate 2 connected to the other end of the hollow wire tube, and a sac 1 connected between the connecting plate 1 and the connecting plate 2. An annular sealed pump air chamber is formed between the connecting plate 1, the hollow wire tube, the connecting plate 2 and the sac 1, and the sealed pump air chamber is connected to the outside through a one-way air guide component 1.

[0012] As a further optimization scheme of the present invention, the one-way air guide component includes a plurality of fixed rods fixedly connected to a connecting plate, a limit plate fixedly connected to the fixed rod, a sliding rod slidably connected to the limit plate, a sealing plate connected to one end of the sliding rod, a spring connected between the limit plate and the sealing plate, and a plurality of air holes provided on the connecting plate, the sealing plate is in contact with the connecting plate, the plurality of air holes are evenly distributed in the coverage area of ​​the plurality of sealing plates, and the sealed pump air chamber is connected to the outside through the plurality of air holes.

[0013] As a further optimization scheme of the present invention, the internal expansion limiting mechanism includes a sealed expansion component and a one-way air guide component 2 arranged on one end where the sealed expansion component is connected to the sealed pump air component. The internal space of the sealed expansion component is connected to the internal space of the sealed pump air component through the one-way air guide component 2.

[0014] As a further optimization scheme of the present invention, the sealed expansion component includes a connecting plate three fixedly connected to the connecting plate two, a sleeve connected to the other end of the connecting plate three, a connecting plate four connected to the other end of the sleeve, and a sac body two connected between the connecting plate three and the connecting plate four, and an annular sealed air storage chamber is formed between the connecting plate three, the sleeve, the connecting plate four and the sac body two, and the sealed air storage chamber is connected to the sealed pump air chamber through the one-way air guide component two.

[0015] As a further optimization scheme of the present invention, the one-way air guide component 2 includes a plurality of limit plates 2 fixedly connected to the outer circular surface of the limit plate 2, a sliding rod 2 slidably connected to the limit plate 2, a sealing plate 2 fixedly connected to one end of the sliding rod 2, a spring 2 connected between the sliding rod 2 and the sealing plate 2, and a plurality of air holes 2 arranged on the connecting plate 3, the air holes 2 penetrate the connecting plate 2 and are connected to the sealing pump air chamber, the plurality of air holes 2 are evenly distributed in the coverage area of ​​the plurality of sealing plates 2, and the sealing plate 2 is in contact with the connecting plate 3.

[0016] As a further optimization scheme of the present invention, a reset mechanism is provided on the sealed pump air assembly, and the reset mechanism includes a normally open assembly and a driven assembly connected to the normally open assembly. The normally open assembly is used to adjust the one-way conduction state between the internal space of the sealed expansion assembly and the internal space of the sealed pump air assembly to a normally open state, and the driven assembly is used to adjust the one-way conduction state between the internal space of the sealed pump air assembly and the outside world to a normally open state.

[0017] As a further optimization scheme of the present invention, the normally open component includes a rotating shaft 1 movably connected to a connecting plate 1, a knob fixedly connected to one end of the rotating shaft 1, a damping wheel 1 fixedly connected to the other end of the rotating shaft 1, a rotating shaft 2 movably connected to the connecting plate 1, a damping wheel 2 fixedly connected to the rotating shaft 2, a wheel band connected between the damping wheel 1 and the damping wheel 2, a nut threadedly connected to the rotating shaft 2, a ring slidably connected to the hollow wire tube, a connecting rod 1 fixedly connected between the ring and the nut, and a sleeve rod fixedly connected to the nut, the sleeve rod is coaxial with the rotating shaft 2, and the sleeve rod is coaxial with one of the air holes 2, the knob is located outside the air chamber of the sealed pump, an air-tight part is provided at the connection between the rotating shaft 1 and the connecting plate 1, and a threaded portion matching the nut is provided on the rotating shaft 2.

[0018] As a further optimization solution of the present invention, the driven assembly includes a connecting rod 2 fixedly connected to the nut and a connecting rod 3 vertically connected to the connecting rod 2, and the other end of the connecting rod 3 is fixedly connected to one of the sliding rods 1.

[0019] The beneficial effects of the present invention are as follows: the present invention adopts a plug-in terminal whose only terminal electrical connection area matches the electrical instrument, which can effectively reduce the resistance of the plug-in terminal when inserted into the electrical instrument, thereby eliminating the situation where the tester manually supports the electrical instrument, and after the plug-in terminal is inserted into the electrical instrument, the plug-in terminal is limited and fixed in the corresponding electrical socket of the electrical instrument through a one-way air pump mechanism and an internal expansion limit mechanism that cooperate with the plug-in terminal, thereby improving the safety of the electrical connection while ensuring the stability of the connection. BRIEF DESCRIPTION OF THE DRAWINGS

[0020] Figure 1 It is a schematic diagram of the overall structure of the present invention;

[0021] Figure 2 It is a diagram showing the matching of the electrical connection wire and the ammeter of the present invention;

[0022] Figure 3 It is a view of the cooperation between the one-way air pumping mechanism and the inner expansion type limiting mechanism of the present invention;

[0023] Figure 4 The present invention Figure 3 A magnified view of point A in FIG.

[0024] Figure 5 The present invention Figure 3 A magnified view of point B in FIG.

[0025] Figure 6 The present invention Figure 3 A magnified view of point C in FIG.

[0026] Figure 7 The present invention Figure 3 A magnified view at D in FIG.

[0027] Figure 8 The present invention Figure 3 Magnified view at E in FIG.

[0028] In the figure: 1, ammeter; 2, cable; 3, connection terminal 1; 4, one-way pump air mechanism; 401, connection plate 1; 402, hollow wire tube; 403, connection plate 2; 404, capsule 1; 405, fixing rod; 406, limit plate 1; 407, slide bar 1; 408, spring 1; 409, sealing plate 1; 410, air hole 1; 5, connection terminal 2; 6, internal expansion limit mechanism; 601, connection plate 3; 602, sleeve; 60 3. Connecting plate four; 604. Bag body two; 605. Limiting plate two; 606. Sliding rod two; 607. Spring two; 608. Sealing plate two; 609. Air hole two; 701. Knob; 702. Rotating shaft one; 703. Damping wheel one; 704. Rotating shaft two; 705. Damping wheel two; 706. Wheel band; 707. Nut; 708. Ring; 709. Connecting rod one; 710. Sleeve rod; 711. Connecting rod two; 712. Connecting rod three. DETAILED DESCRIPTION

[0029] The subject matter described herein will now be discussed with reference to example embodiments. It should be understood that the discussion of these embodiments is only intended to enable those skilled in the art to better understand and implement the subject matter described herein. In addition, the features described relative to some examples may also be combined in other examples.

[0030] like Figure 1-Figure 8 As shown, a high-precision current measuring device with an anti-leakage structure comprises:

[0031] Ammeter 1, used to obtain current data of the instrument under test;

[0032] An electrical connection line, which is used to electrically connect the ammeter 1 to the instrument to be tested;

[0033] The electrical connection line includes a cable 2, a connection terminal 1 3 connected to one end of the cable 2, a one-way air pumping mechanism 4 connected to the other end of the cable 2, and a connection terminal 2 5 and an inner expansion limit mechanism 6 connected to the other end of the one-way air pumping mechanism 4. The inner expansion limit mechanism 6 is sleeved on the outside of the connection terminal 2 5, and the cable 2 is electrically connected to the connection terminal 2 5;

[0034] When the connecting terminal 2 5 and the inward expansion limit mechanism 6 are both inserted into the socket of the instrument to be tested, the one-way air pumping mechanism 4 is used to pump a set amount of gas into the inward expansion limit mechanism 6. When the air pressure in the inward expansion limit mechanism 6 reaches a set value, the inward expansion limit mechanism 6 contacts the inner wall of the socket of the instrument to be tested and applies a set pressure to it.

[0035] It should be noted that when the current of the instrument to be tested is detected, the connecting terminal 2 5 and the internal expansion type limit mechanism 6 are simultaneously inserted into the jack of the instrument to be tested. Since the diameters of the connecting terminal 2 5 and the internal expansion type limit mechanism 6 are much smaller than the diameter of the entrance area of ​​the jack, the connecting terminal 2 5 can be inserted into the jack of the instrument to be tested under a relatively low resistance state. At this time, the internal expansion type limit mechanism 6 is in an unexpanded state, and the connection relationship between the connecting terminal 2 5 and the instrument to be tested is unstable. At this time, the external air can be unidirectionally pumped into the internal expansion type limit mechanism 6 by repeatedly squeezing the unidirectional pump air mechanism 4, so that the internal expansion type limit mechanism 6 is stable. The limiting mechanism 6 gradually expands and finally comes into close contact with the jack of the instrument to be tested, thereby achieving stable limiting fixation. When the one-way air pumping mechanism 4 is repeatedly squeezed, the internal space of the one-way air pumping mechanism 4 is reduced, generating positive pressure. Under the influence of the positive pressure, the gas in the one-way air pumping mechanism 4 can only be discharged into the inward expansion limiting mechanism 6. When the one-way air pumping mechanism 4 is released, the amount of gas in the one-way air pumping mechanism 4 is reduced, and in the process of recovery, the internal volume increases to generate negative pressure. The negative pressure can pump the outside air back into the one-way air pumping mechanism 4, thereby achieving a continuous one-way air pumping effect.

[0036] In an optional embodiment, if Figure 3 and Figure 4 As shown, the one-way air pumping mechanism 4 includes a sealed air pumping component and a one-way air guide component 1 arranged at one end of the sealed air pumping component, and the internal space of the sealed air pumping component is connected to the outside through the one-way air guide component 1.

[0037] The sealed pump air component includes a connecting plate 401 connected to the other end of the cable 2, a hollow wire tube 402 connected to the middle of the other end of the connecting plate 401, a connecting plate 403 connected to the other end of the hollow wire tube 402, and a sac 404 connected between the connecting plate 401 and the connecting plate 403. An annular sealed pump air chamber is formed between the connecting plate 401, the hollow wire tube 402, the connecting plate 403 and the sac 404. The sealed pump air chamber is connected to the outside through a one-way air guide component.

[0038] The one-way air guide component includes a plurality of fixed rods 405 fixedly connected to a connecting plate 401, a limiting plate 406 fixedly connected to the fixed rod 405, a sliding rod 407 slidably connected to the limiting plate 406, a sealing plate 409 connected to one end of the sliding rod 407, a spring 408 connected between the limiting plate 406 and the sealing plate 409, and a plurality of air holes 410 arranged on the connecting plate 401, the sealing plate 409 is in contact with the connecting plate 401, the plurality of air holes 410 are evenly distributed in the coverage area of ​​the plurality of sealing plates 409, and the sealed pump air chamber is connected to the outside through the plurality of air holes 410.

[0039] It should be noted that, as mentioned above, during the one-way air pumping process, the one-way air pumping mechanism 4 manually squeezes the bladder 404, and the volume of an annular sealed air pumping chamber formed between the connecting plate 401, the hollow wire tube 402, the connecting plate 403 and the bladder 404 is compressed and reduced, thereby generating a positive pressure. When the positive pressure is applied to the sealing plate 409, the sealing plate 409 is tightly attached to the connecting plate 401 under the unidirectional action of the spring 408 and the positive pressure, and the multiple air holes 410 in the covered area are sealed, thereby isolating the sealed air pumping chamber from the outside, so that the air in the sealed air pumping chamber can only be discharged into the inner expansion limiting mechanism 6. , thereby achieving unidirectional pumping of air into the inner expansion limit mechanism 6 under the extrusion state, so that the inner expansion limit mechanism 6 gradually expands and deforms, and applies a set pressure to the inner wall of the jack of the instrument to be tested, and when the capsule 404 is released, the capsule 404 is reset under its own elastic action, the internal volume increases, and negative pressure is generated, and the negative pressure acts in the opposite direction on the sealing plate 409. Under the synergistic effect of the external atmospheric pressure, the sealing plate 409 is forced to move toward the inside of the sealed pump air chamber, and multiple air holes 410 are opened, so that the gas can enter the sealed pump air chamber from the air holes 410 to replenish the amount of gas in the sealed pump air chamber, thereby realizing a repeated pumping process.

[0040] In an optional embodiment, if Figure 3 and Figure 5As shown, the internal expansion limiting mechanism 6 includes a sealed expansion component and a one-way air guide component 2 arranged on one end where the sealed expansion component is connected to the sealed pump air component. The internal space of the sealed expansion component is connected to the internal space of the sealed pump air component through the one-way air guide component 2.

[0041] The sealed expansion assembly includes a connecting plate three 601 fixedly connected to the connecting plate two 403, a sleeve 602 connected to the other end of the connecting plate three 601, a connecting plate four 603 connected to the other end of the sleeve 602, and a bladder body two 604 connected between the connecting plate three 601 and the connecting plate four 603. An annular sealed air storage chamber is formed between the connecting plate three 601, the sleeve 602, the connecting plate four 603 and the bladder body two 604, and the sealed air storage chamber is connected to the sealed pump air chamber through the one-way air guide assembly two.

[0042] The one-way air guide component 2 includes a plurality of limit plates 2 605 fixedly connected to the outer circumferential surface of the limit plate 2 605, a slide rod 2 606 slidably connected to the limit plate 2 605, a sealing plate 2 608 fixedly connected to one end of the slide rod 2 606, a spring 2 607 connected between the slide rod 2 606 and the sealing plate 2 608, and a plurality of air holes 2 609 arranged on the connecting plate 3 601, the air holes 2 609 penetrate the connecting plate 2 403 and are connected to the sealing pump air chamber, the plurality of air holes 2 609 are evenly distributed in the coverage area of ​​the plurality of sealing plates 2 608, and the sealing plate 2 608 is in contact with the connecting plate 3 601.

[0043] It should be noted that, as mentioned above, when the bladder body 1 404 is squeezed, the volume of an annular sealed pump air chamber formed between the connecting plate 1 401, the hollow wire tube 402, the connecting plate 2 403 and the bladder body 1 404 is compressed and reduced, and a positive pressure is generated. The positive pressure can act on the sealing plate 2 608 and push it to move toward the inside of the sealed air storage chamber. During this process, the spring 2 607 is in a compressed state, and as the sealing plate 2 608 is no longer in contact with the connecting plate 3 601, the plurality of air holes 2 609 are in an open state. In the open state, the air in the sealed pump air chamber can be introduced into the sealed air storage chamber from the air hole 609. As the gas enters, the pressure acting on the sealing plate 608 gradually decreases until the bag body 404 is released. Under the coordinated action of the spring 607 and the air pressure inside the sealed air storage chamber, the sealing plate 608 can quickly reset and reseal the air hole 609. In this process, only a small amount of gas will flow back into the sealed pump air chamber, and the reflux amount will gradually decrease as the air pressure in the sealed air storage chamber gradually increases.

[0044] In an optional embodiment, if Figure 3-Figure 4 as well as Figure 6-Figure 8As shown, a reset mechanism is provided on the sealed pump air assembly, and the reset mechanism includes a normally open assembly and a driven assembly connected to the normally open assembly. The normally open assembly is used to adjust the one-way conduction state between the internal space of the sealed expansion assembly and the internal space of the sealed pump air assembly to the normally open state, and the driven assembly is used to adjust the one-way conduction state between the internal space of the sealed pump air assembly and the outside world to the normally open state.

[0045] The normally open assembly includes a rotating shaft 702 movably connected to the connecting plate 401, a knob 701 fixedly connected to one end of the rotating shaft 702, a damping wheel 703 fixedly connected to the other end of the rotating shaft 702, a rotating shaft 704 movably connected to the connecting plate 401, a damping wheel 705 fixedly connected to the rotating shaft 704, a wheel belt 706 connected between the damping wheel 703 and the damping wheel 705, a nut 707 threadedly connected to the rotating shaft 704, and a sliding connection. A collar 708 is provided on the hollow wire tube 402, a connecting rod 709 fixedly connected between the collar 708 and the nut 707, and a sleeve rod 710 fixedly connected to the nut 707. The sleeve rod 710 is coaxial with the second rotating shaft 704, and the sleeve rod 710 is coaxial with one of the second air holes 609. The knob 701 is located outside the air chamber of the sealed pump. An airtight part is provided at the connection between the rotating shaft 702 and the connecting plate 401, and a threaded portion matching the nut 707 is provided on the second rotating shaft 704.

[0046] The driven assembly includes a second connecting rod 711 fixedly connected to the nut 707 and a third connecting rod 712 vertically connected to the second connecting rod 711 , and the other end of the third connecting rod 712 is fixedly connected to one of the sliding rods 407 .

[0047] It should be noted that, as mentioned above, when the bladder body 2 604 expands and contacts the inner wall of the jack of the instrument to be tested at a set pressure, the connecting terminal 2 5 is in a stable electrical connection state, and when the connecting terminal 2 5 needs to be pulled out from the instrument to be tested, the gas in the sealed air storage chamber needs to be discharged, so that the bladder body 2 604 can be restored to its initial state. At this time, the rotating shaft 1 702 and the damping wheel 1 703 can be driven to rotate in the same direction by rotating the knob 701. When the damping wheel 1 703 rotates, the damping wheel 2 705 is driven to rotate in the same direction through the belt 706. When the damping wheel 2 705 rotates, the rotating shaft 2 704 can be driven to rotate in the same direction. After the rotating shaft 2 704 rotates, the nut 707 and the sleeve rod 710 fixedly connected to the nut 707 can be driven to move toward the corresponding air hole 2 609 until the sleeve rod 710 passes through. The corresponding air hole 609 will lift up the sealing plate 608 covering the air hole 609. At this time, a part of the air hole 609 is in an open state, and the sealed air storage chamber is in a two-way communication state with the sealed pump air chamber. As the nut 707 moves, the connecting rod 2 711 and the connecting rod 3 712 connected thereto move in the same direction, and pull a sliding rod 407 connected to the connecting rod 3 712 to move in the same direction. As the sliding rod 407 moves, part of the air hole 410 covered under the sliding rod 407 area is in an open state. At this point, the sealed air storage chamber, the sealed pump air chamber and the outside world are all in a connected state, and the gas in the sealed air storage chamber can be continuously discharged to the outside world, thereby realizing the resetting of the capsule 404, thereby facilitating the removal of the connecting terminal 2 5.

[0048] The entire process of insertion and removal does not require human contact with the instrument under test, thereby eliminating contact with the instrument under test that may be in a leakage state from the source, effectively eliminating the possibility of electric shock.

[0049] The present embodiment is described above, but the present embodiment is not limited to the above-mentioned specific implementation manner. The above-mentioned specific implementation manner is merely illustrative and not restrictive. Under the guidance of the present embodiment, ordinary technicians in this field can also make many forms, which are all within the protection of the present embodiment.

Claims

1. A high-precision current measuring device with an anti-leakage structure, characterized in that: include: An ammeter (1), used to obtain current data of the instrument under test; An electrical connection line, the electrical connection line being used to electrically connect the ammeter (1) to the instrument to be tested; The electrical connection line comprises a cable (2), a first connection terminal (3) connected to one end of the cable (2), a one-way air pumping mechanism (4) connected to the other end of the cable (2), and a second connection terminal (5) and an internal expansion limit mechanism (6) connected to the other end of the one-way air pumping mechanism (4), wherein the internal expansion limit mechanism (6) is sleeved on the outside of the second connection terminal (5), and the cable (2) is electrically connected to the second connection terminal (5); When the second connection terminal (5) and the internal expansion limit mechanism (6) are both inserted into the socket of the instrument to be tested, the one-way air pumping mechanism (4) is used to pump a set amount of gas into the internal expansion limit mechanism (6); when the air pressure in the internal expansion limit mechanism (6) reaches a set value, the internal expansion limit mechanism (6) contacts the inner wall of the socket of the instrument to be tested and applies a set value of pressure thereto.

2. A high-precision current measuring device with an anti-leakage structure according to claim 1, characterized in that: The one-way air pumping mechanism (4) comprises a sealed air pumping component and a one-way air guide component 1 arranged at one end of the sealed air pumping component, and the internal space of the sealed air pumping component is connected to the outside through the one-way air guide component 1.

3. A high-precision current measuring device with an anti-leakage structure according to claim 2, characterized in that: The sealed pump air component comprises a connecting plate 1 (401) connected to the other end of the cable (2), a hollow wire tube (402) connected to the middle of the other end of the connecting plate 1 (401), a connecting plate 2 (403) connected to the other end of the hollow wire tube (402), and a sac 1 (404) connected between the connecting plate 1 (401) and the connecting plate 2 (403), wherein an annular sealed pump air chamber is formed between the connecting plate 1 (401), the hollow wire tube (402), the connecting plate 2 (403) and the sac 1 (404), and the sealed pump air chamber is connected to the outside through the one-way air guide component 1.

4. A high-precision current measuring device with an anti-leakage structure according to claim 3, characterized in that: The one-way air guide component includes a plurality of fixed rods (405) fixedly connected to a connecting plate (401), a limiting plate (406) fixedly connected to the fixed rod (405), a sliding rod (407) slidably connected to the limiting plate (406), a sealing plate (409) connected to one end of the sliding rod (407), a spring (408) connected between the limiting plate (406) and the sealing plate (409), and a plurality of air holes (410) provided on the connecting plate (401), the sealing plate (409) is in contact with the connecting plate (401), the plurality of air holes (410) are evenly distributed in the coverage area of ​​the plurality of sealing plates (409), and the sealed pump air chamber is connected to the outside through the plurality of air holes (410).

5. A high-precision current measuring device with an anti-leakage structure according to claim 4, characterized in that: The internal expansion limiting mechanism (6) comprises a sealed expansion component and a one-way air guide component 2 arranged on one end where the sealed expansion component is connected to the sealed pump air component, and the internal space of the sealed expansion component is connected to the internal space of the sealed pump air component through the one-way air guide component 2.

6. A high-precision current measuring device with an anti-leakage structure according to claim 5, characterized in that: The sealed expansion assembly comprises a connecting plate three (601) fixedly connected to the connecting plate two (403), a sleeve (602) connected to the other end of the connecting plate three (601), a connecting plate four (603) connected to the other end of the sleeve (602), and a bladder body two (604) connected between the connecting plate three (601) and the connecting plate four (603), wherein an annular sealed air storage chamber is formed between the connecting plate three (601), the sleeve (602), the connecting plate four (603) and the bladder body two (604), and the sealed air storage chamber is connected to the sealed pump air chamber through the one-way air guide assembly two.

7. A high-precision current measuring device with an anti-leakage structure according to claim 6, characterized in that: The one-way air guide component 2 includes a plurality of limit plates 2 (605) fixedly connected to the outer circumferential surface of the limit plate 2 (605), a slide rod 2 (606) slidably connected to the limit plate 2 (605), a sealing plate 2 (608) fixedly connected to one end of the slide rod 2 (606), a spring 2 (607) connected between the slide rod 2 (606) and the sealing plate 2 (608), and a plurality of air holes 2 (609) provided on the connecting plate 3 (601), wherein the air holes 2 (609) penetrate the connecting plate 2 (403) and are connected to the sealing pump air chamber, and the plurality of air holes 2 (609) are evenly distributed in the coverage area of ​​the plurality of sealing plates 2 (608), and the sealing plate 2 (608) is in contact with the connecting plate 3 (601).

8. A high-precision current measuring device with an anti-leakage structure according to claim 7, characterized in that: The sealed pump air assembly is provided with a reset mechanism, which includes a normally open assembly and a driven assembly connected to the normally open assembly. The normally open assembly is used to adjust the one-way conduction state between the internal space of the sealed expansion assembly and the internal space of the sealed pump air assembly to the normally open state, and the driven assembly is used to adjust the one-way conduction state between the internal space of the sealed pump air assembly and the outside world to the normally open state.

9. A high-precision current measuring device with an anti-leakage structure according to claim 8, characterized in that: The normally open component comprises a rotating shaft (702) movably connected to the connecting plate (401), a knob (701) fixedly connected to one end of the rotating shaft (702), a damping wheel (703) fixedly connected to the other end of the rotating shaft (702), a rotating shaft (704) movably connected to the connecting plate (401), a damping wheel (705) fixedly connected to the rotating shaft (704), a wheel belt (706) connected between the damping wheel (703) and the damping wheel (705), a nut (707) threadedly connected to the rotating shaft (704), and a nut (708) slidably connected to the hollow guide. A collar (708) on the wire tube (402), a connecting rod (709) fixedly connected between the collar (708) and the nut (707), and a sleeve rod (710) fixedly connected to the nut (707), wherein the sleeve rod (710) is coaxial with the second rotating shaft (704), and the sleeve rod (710) is coaxial with one of the second air holes (609), the knob (701) is located outside the air chamber of the sealed pump, an airtight member is provided at the connection between the first rotating shaft (702) and the first connecting plate (401), and a threaded portion matching the nut (707) is provided on the second rotating shaft (704).

10. A high-precision current measuring device with an anti-leakage structure according to claim 9, characterized in that: The driven assembly comprises a second connecting rod (711) fixedly connected to a nut (707) and a third connecting rod (712) vertically connected to the second connecting rod (711), and the other end of the third connecting rod (712) is fixedly connected to one of the sliding rods (407).

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