A meter proving device

Abstract

The utility model discloses a kind of measuring instrument calibrating device, it is related to instrument detection technical field, comprising: detection mechanism, gas transmission structure and limiting mechanism, the detection mechanism includes base, cover plate is fixed on the upper surface of base by bolt, the assembly pipe of bearing and the upper surface rotation connection of cover plate, three groups of connecting pipes are set on assembly pipe surface equidistantly, each group contains three connecting pipes, connecting pipe upper end is equipped with threaded cylinder, one threaded cylinder is installed reference barometer, and the rest are installed to be detected barometer.Compared with prior art, the utility model has the beneficial effects that: through the design of three groups of nine channels parallel type connecting pipe, the comparison detection of 8 sets of to-be-detected instruments and 1 set of reference instrument can be completed simultaneously by single clamping, compared with traditional single table series detection mode, the detection efficiency is improved, rotary assembly pipe structure supports three-station rapid switching, and cooperation electric regulating valve realizes the automatic grouping detection of different range section.

Description

Technical Field

[0001] This utility model relates to the field of instrument testing technology, and in particular to a calibration device for measuring instruments. Background Technology

[0002] In the field of industrial automation and process control, pressure gauges are key measuring instruments, and their accuracy directly affects production safety and quality control. Traditional calibration devices generally suffer from the following technical defects: current equipment mostly uses a single air path to connect the instrument under test, allowing only 1-2 instruments to be tested at a time, resulting in long testing cycles and frequent manual operations. For example, the device for pressure gauge metrological testing proposed in application number CN202222759404.1, although optimizing the single-gauge connection efficiency through a guide needle structure, does not solve the bottleneck problem of batch testing. To address these defects, we propose a metrological instrument calibration device. Utility Model Content

[0003] The purpose of this invention is to address the shortcomings of existing technologies by proposing a calibration device for measuring instruments.

[0004] To address the problems existing in the prior art, this utility model adopts the following technical solution: a measuring instrument calibration device, comprising:

[0005] The testing mechanism includes a base, a cover plate fixed to the upper surface of the base by bolts, an assembly tube rotatably connected to the upper surface of the cover plate by bearings, three sets of connecting tubes are equidistantly arranged on the surface of the assembly tube, each set containing three connecting tubes, and a threaded cylinder is provided at the upper end of the connecting tube, one of which is equipped with a reference pressure gauge, and the others are equipped with pressure gauges to be tested.

[0006] The gas transmission structure includes a high-pressure gas cylinder, an exhaust pipe and an inlet pipe. The exhaust pipe is connected to the lower end of the assembly pipe through a rotary joint and is equipped with an electric regulating valve. The inlet pipe is connected to a gas pump and is equipped with a one-way valve.

[0007] A limiting mechanism is provided above the cover plate to limit the assembly tube.

[0008] Preferably, a shut-off valve is provided on the surface of the connecting pipe to control the opening and closing of the gas path in the connecting pipe.

[0009] Preferably, the limiting mechanism includes a guide sleeve fixedly installed on the upper surface of the cover plate, a limiting pin axially slidably connected to the inner wall of the guide sleeve, a baffle integrally formed on the end of the limiting pin, a limiting plate fixedly installed in the middle section of the limiting pin, a return spring sleeved on the surface of the limiting pin and abutting between the guide sleeve and the limiting plate, a limiting ring fixedly installed on the outer periphery of the assembly tube, and three arc-shaped limiting holes evenly distributed along the circumferential direction of the limiting ring.

[0010] Preferably, the return spring drives the end of the limiting pin to insert into any limiting hole in its natural state to achieve circumferential positioning.

[0011] Preferably, the working end of the limiting pin is an arc-shaped surface, and its radius of curvature is adapted to the inner diameter of the limiting hole.

[0012] Preferably, the air inlet pipe is installed at the air inlet end of the high-pressure gas cylinder, and the exhaust pipe is installed at the exhaust end of the high-pressure gas cylinder.

[0013] Preferably, a pressure relief valve is fixedly installed at the top end of the assembly pipe.

[0014] Preferably, the high-pressure gas cylinder is equipped with a safety valve.

[0015] Compared with the prior art, the beneficial effects of this utility model are:

[0016] 1. Through the design of three sets of nine-channel parallel connecting pipes, the comparison test of 8 instruments under test and 1 reference instrument can be completed simultaneously in a single clamping, which improves the testing efficiency compared with the traditional single instrument series testing method. The rotary assembly pipe structure supports rapid switching of three positions and, together with the electric regulating valve, realizes automated group testing of different range segments.

[0017] 2. The limiting mechanism can achieve precise positioning of the assembly tube by 120° indexing rotation. The operator only needs to pull the baffle with one hand to complete the work position switching, while ensuring the stability of the assembly tube when installing the pressure gauge to be tested and the reference pressure gauge. Attached Figure Description

[0018] The accompanying drawings are provided to further illustrate the present invention. The illustrative embodiments and descriptions of the present invention are used to explain the present invention and do not constitute an undue limitation. In the drawings:

[0019] Figure 1 This is a three-dimensional schematic diagram of the present invention;

[0020] Figure 2 This is a top sectional view of the assembly tube of this utility model;

[0021] Figure 3 This is a cross-sectional view of the testing mechanism of this utility model;

[0022] Figure 4 for Figure 2 Enlarged structural diagram at point A in the middle.

[0023] The components in the diagram are numbered as follows: 10 Base, 11 Cover plate, 12 Assembly pipe, 13 Connecting pipe, 14 Threaded cylinder, 15 Reference pressure gauge, 16 Pressure gauge to be tested, 20 High-pressure gas cylinder, 21 Exhaust pipe, 22 Inlet pipe, 23 Rotary joint, 24 Electric regulating valve, 25 Air pump, 26 One-way valve, 27 Safety valve, 30 Shut-off valve, 40 Guide sleeve, 41 Limit pin, 42 Baffle, 43 Limit plate, 44 Return spring, 45 Limit ring, 46 Limit hole, 50 Pressure relief valve. Detailed Implementation

[0024] The technical solutions of the present invention will be clearly and completely described below with reference to the accompanying drawings of the embodiments of the present invention.

[0025] Please see Figure 1-4 This utility model provides a technical solution: a metering instrument calibration device, comprising: a detection mechanism, a gas supply structure, and a limiting mechanism.

[0026] The testing mechanism includes a base 10, which is fixed to the testing platform by M12 anchor bolts. A cover plate 11 is fixed to the upper surface of the base 10 by bolts, and a sealing ring is provided between the cover plate 11 and the base 10.

[0027] A circular hole is opened on the upper surface of the cover plate 11. An assembly tube 12 is rotatably connected to the circular hole through a bearing. The assembly tube 12 is made of 304 stainless steel pipe with a diameter of 80×5mm. The inner ring of the bearing adopts an H7 / k6 transition fit. Three sets of connecting tubes 13 are equidistantly arranged on the surface of the assembly tube 12. Each set contains three connecting tubes 13. A threaded cylinder 14 is provided at the upper end of the connecting tube 13. One of the threaded cylinders 14 is equipped with a reference pressure gauge 15, and the others are equipped with pressure gauges 16 to be tested (according to the requirements of JJG52-99, the error of the standard instrument should not be greater than 1 / 4 of the allowable error of the gauge under test. If testing an industrial gauge with an accuracy of ±1.6%FS, the accuracy of the reference instrument should be above 0.4).

[0028] A shut-off valve 30 is installed on the surface of the connecting pipe 13 to control the opening and closing of the air passage of the connecting pipe 13, or an automatic valve (such as a solenoid valve) is integrated on the surface of the connecting pipe 13 to replace the shut-off valve 30 and is opened and closed sequentially by the controller. The connecting pipe 13 is a Φ10mm copper pipe, and the threaded cylinder 14 is machined into a standard instrument interface. When the instrument is replaced, the shut-off valve 30 can cut off the air passage of the corresponding workstation individually.

[0029] The gas transmission structure includes a high-pressure gas cylinder 20, an exhaust pipe 21, and an inlet pipe 22. The exhaust pipe 21 is connected to the lower end of the assembly pipe 12 via a rotary joint 23. The rotary joint 23 is a double-end mechanical seal rotary joint with a sealing pressure ≥10MPa. An electric regulating valve 24 is installed on the surface of the exhaust pipe 21, and a pressure sensor is linked to achieve closed-loop control. The inlet pipe 22 is connected to a gas pump 25 and is equipped with a one-way valve 26. The inlet pipe 22 is installed at the inlet end of the high-pressure gas cylinder 20, and the exhaust pipe 21 is installed at the exhaust end of the high-pressure gas cylinder 20.

[0030] A pressure relief valve 50 is fixedly installed at the top of the assembly pipe 12. The high-pressure gas cylinder 20 is equipped with a safety valve 27. The safety valve 27 is set at 9MPa±0.5MPa. After the air pump 25 is started, compressed air enters the high-pressure gas cylinder 20 through the one-way valve 26. When the pressure reaches 6MPa, it automatically stops. The electric regulating valve 24 is opened, and the gas enters the assembly pipe 12 through the rotary joint 23 and is distributed to each testing station. The pressure relief valve 50 is set at 8MPa and automatically opens to exhaust gas when there is overpressure.

[0031] A limiting mechanism is located above the cover plate 11 to limit the assembly tube 12. The limiting mechanism includes a guide sleeve 40 fixedly installed on the upper surface of the cover plate 11, a limiting pin 41 axially slidably connected to the inner wall of the guide sleeve 40, a baffle 42 integrally formed on the end of the limiting pin 41, a limiting plate 43 fixedly installed in the middle section of the limiting pin 41, a return spring 44 sleeved on the surface of the limiting pin 41 and abutting between the guide sleeve 40 and the limiting plate 43, a limiting ring 45 fixedly installed on the outer periphery of the assembly tube 12, and three arc-shaped limiting holes 46 evenly distributed along the circumference of the limiting ring 45. The limiting ring 45 and the assembly tube 12 are interference-fitted, and a handle is fixedly installed on one end of the baffle 42.

[0032] In its natural state, the return spring 44 drives the end of the limit pin 41 to insert into any limit hole 46 to achieve circumferential positioning. The working end of the limit pin 41 is an arc surface with a radius of curvature that matches the inner diameter of the limit hole 46. When the assembly tube 12 is rotated to the first position, the limit pin 41 automatically engages with the limit hole 46 under the force of the return spring 44. The difference between the readings of each pressure gauge 16 to be tested and the reference pressure gauge 15 is compared. If the error exceeds ±1.6%FS, it is deemed unqualified.

[0033] Specifically, the working principle and operation method of this utility model are as follows:

[0034] Screw the reference pressure gauge 15 into one of the threaded cylinders 14 until the sealing gasket is tightened. After the test pressure gauge 16 is installed, close the corresponding shut-off valve 30. Start the air pump 25 to a pressure value of 6MPa and then stop the air pump 25. Open the electric regulating valve 24 and observe that the pressure rise rate of the assembly pipe 12 is ≤0.3MPa / s. Pull down the handle to make the limit pin 41 disengage from the limit hole 46. Rotate the assembly pipe 12 to the first station and hear a "click" positioning sound. Open the corresponding station shut-off valves 30 in sequence. After the reading of the test pressure gauge 16 stabilizes, record the deviation from the reading of the reference pressure gauge 15. The quality of the pressure gauge can be detected by comparison.

[0035] When the pressure exceeds 8MPa, the pressure relief valve 50 should open automatically. In an emergency, manually close the electric regulating valve 24 and disconnect the power supply.

[0036] The above description is only a preferred embodiment of the present utility model, but the protection scope of the present utility model is not limited thereto. Any equivalent substitutions or changes made by those skilled in the art based on the technical solution and concept of the present utility model should be included within the protection scope of the present utility model.

Claims

1. A calibration device for measuring instruments, characterized in that, include: The testing mechanism includes a base (10), a cover plate (11) fixed to the upper surface of the base (10) by bolts, and an assembly pipe (12) rotatably connected to the upper surface of the cover plate (11) by bearings. Three sets of connecting pipes (13) are equidistantly arranged on the surface of the assembly pipe (12), each set containing three connecting pipes (13). A threaded cylinder (14) is provided at the upper end of the connecting pipe (13), one of the threaded cylinders (14) is equipped with a reference pressure gauge (15), and the others are equipped with pressure gauges (16) to be tested. The gas transmission structure includes a high-pressure gas cylinder (20), an exhaust pipe (21) and an intake pipe (22). The exhaust pipe (21) is connected to the lower end of the assembly pipe (12) through a rotary joint (23). The exhaust pipe (21) is equipped with an electric regulating valve (24). The intake pipe (22) is connected to a gas pump (25) and is equipped with a one-way valve (26). A limiting mechanism is provided above the cover plate (11) to limit the assembly tube (12).

2. The measuring instrument calibration device according to claim 1, characterized in that: A shut-off valve (30) is provided on the surface of the connecting pipe (13) to control the air passage opening and closing of the connecting pipe (13).

3. The measuring instrument calibration device according to claim 1, characterized in that: The limiting mechanism includes a guide sleeve (40) fixedly installed on the upper surface of the cover plate (11), a limiting pin (41) axially slidably connected to the inner wall of the guide sleeve (40), a baffle (42) integrally formed on the end of the limiting pin (41), a limiting plate (43) fixedly installed in the middle section of the limiting pin (41), a return spring (44) sleeved on the surface of the limiting pin (41) and abutting between the guide sleeve (40) and the limiting plate (43), a limiting ring (45) fixedly installed on the outer periphery of the assembly tube (12), and three arc-shaped limiting holes (46) evenly distributed along the circumferential direction of the limiting ring (45).

4. The measuring instrument calibration device according to claim 3, characterized in that: The return spring (44) drives the end of the limiting pin (41) to insert into any limiting hole (46) in its natural state to achieve circumferential positioning.

5. A calibration device for measuring instruments according to claim 3, characterized in that: The working end of the limiting pin (41) is an arc surface, and its radius of curvature is adapted to the inner diameter of the limiting hole (46).

6. The measuring instrument calibration device according to claim 1, characterized in that: The air inlet pipe (22) is installed at the air inlet end of the high-pressure gas cylinder (20), and the exhaust pipe (21) is installed at the exhaust end of the high-pressure gas cylinder (20).

7. A calibration device for measuring instruments according to claim 1, characterized in that: A pressure relief valve (50) is fixedly installed at the top end of the assembly pipe (12).

8. A calibration device for measuring instruments according to claim 1, characterized in that: The high-pressure gas cylinder (20) is equipped with a safety valve (27).

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