High-precision automatic detection device for oil pressure gauge

Abstract

The invention discloses an automatic pressure detection device for oil source recirculation. The automatic pressure detection device is characterized by comprising an oil source system, a circulating system, an injection system and a loading system, a standard pressure gauge, an industrial all-in-one machine, a high-pressure ball valve and a tested piece product interface are arranged; the oil source system is provided with a clean oil tank and a dirty oil tank; the circulating system comprises a hydraulic pump and a motor A, a pipeline filter assembly is arranged in a pipeline, and the pipeline is shunted to a clean oil tank or a dirty oil tank through an electromagnetic reversing valve; the injection system comprises a driving device, a lead screw assembly is driven by the driving device, the lead screw assembly is linked with an oil cylinder, and the oil cylinder is connected with the loading system; and the loading system comprises a direct-acting overflow valve connected with the oil cylinder, and the direct-acting overflow valve is connected to a tested piece product interface through a one-way valve B and a high-pressure ball valve. High-precision, high-efficiency and high-stability automatic detection of the pressure gauge is realized, the labor cost is reduced, long-term operation of the device is ensured, oil source pollution is avoided, and resource waste is reduced.

Description

Technical Field

[0001] The invention relates to instrument detection technology, in particular to a high-precision automatic detection device for an oil pressure gauge. Background Art

[0002] Pressure detection is an important detection method for pressure instruments. The current detection methods are restricted by hardware and software such as the small number of equipment, large demand for standard instruments, serious oil source pollution, and high cost. In the fields of industry and scientific research, high-precision, automated, and fast-response high-pressure instrument detection devices are urgently needed.

[0003] There are also devices in this regard in the public technology, such as the patent publication number CN116735077A, a pressure instrument detection device and detection method, which includes a bracket, a support plate with an L-shaped upper end, which is used to fix the device as a whole; an adjustment component, which is used to place the instrument; a snap-fit ​​component, which is used to detect the transmission; a snap-fit ​​guide component, which is vertically slidably arranged on the upper end of the support plate, which is used to approach and separate the detection part; a connecting mechanism, which is fixedly arranged at the lower end of the snap-fit ​​guide component, and the connecting mechanism consists of a leather tube opening and closing component and a driving component, which are respectively used for the kit and drive during instrument detection. The main problem solved by this device is still the conversion from traditional manual to automatic installation of the pressure gauge to be tested. It realizes the expansion of the leather tube through the connecting mechanism, the curved surface transmission and the sliding structure, so that when the pressure gauge is tested, the air connection leather tube and the pressure gauge connecting tube are automatically connected. The snap-fit ​​component uses a concentric crank slider mechanism to separate the snap-fit ​​and separation strokes to realize the automatic snap-fit ​​and separation of the leather tube.

[0004] Although this device can be applied to assembly line operations to improve the efficiency of meter installation and replacement, there is no specific technical solution for the test accuracy, or it is still determined by manual visual inspection, and the oil pressure gauge inspection relies on operational experience. In addition, due to the complex structure of this detection device, the machined structure requires high precision and its own cost is also high. In addition, as a traditional detection method, its detection means are cumbersome and time-inefficient. Summary of the invention

[0005] The purpose of the present invention is to solve the above-mentioned problems and to provide a high-precision automatic detection device for an oil pressure gauge, which utilizes easily available high-precision cylinder components, screw components and PLC control systems, and has the characteristics of simple structure, high adjustment accuracy, high resolution, wide pressure adjustment range, pressure adjustment linearity, fast response, and high degree of automation.

[0006] The above technical problems of the present invention are mainly solved by the following technical solutions: a high-precision automatic detection device for an oil pressure gauge, comprising a cylinder assembly, a screw assembly and a driving mechanism connected in sequence, characterized in that the cylinder assembly comprises an oil cylinder for oil source injection and output, an oil rod arranged in the oil cylinder, a first bell-shaped cover connected to the rear end of the oil cylinder, a sleeve connected to the oil rod is arranged in the first bell-shaped cover, and a limit plate is arranged on the sleeve.

[0007] A second bell-shaped cover is arranged outside the screw rod assembly, the screw rod is positioned inside the second bell-shaped cover through a bearing seat, and the screw rod assembly is provided with two proximity switches.

[0008] The driving mechanism comprises a motor, and the proximity switch and the motor are connected to a PLC control system.

[0009] In the aforementioned high-precision automatic detection device for the oil pressure gauge, preferably, a proximity switch base is provided on the second bell-shaped cover, a through hole compatible with the proximity switch is opened on the proximity switch base, a limit plate passes through the through hole, and induction is generated when the limit plate contacts the proximity switch.

[0010] In the aforementioned high-precision automatic detection device for an oil pressure gauge, preferably, the driving mechanism further includes a reducer, and the screw rod is connected to the reducer via a coupling.

[0011] In the aforementioned high-precision automatic detection device for an oil pressure gauge, preferably, a third bell-shaped cover is provided between the screw assembly and the driving device, and the third bell-shaped cover is connected to the second bell-shaped cover as a whole.

[0012] In the aforementioned high-precision automatic detection device for the oil pressure gauge, preferably, one end of the first bell-shaped cover is connected to the oil cylinder through a flange structure, and the other end of the first bell-shaped cover is connected to the second bell-shaped cover; a groove is provided on the upper part of the first bell-shaped cover, and the bearing seat cooperates with the groove.

[0013] In the aforementioned high-precision automatic detection device for the oil pressure gauge, preferably, one end of the sleeve is connected to the oil rod, and the other end of the sleeve is connected to the screw rod, a guide groove is provided on the sleeve, and the end surface where the sleeve is connected to the oil rod is matched by a countersunk shaft-wrapped fit.

[0014] In the aforementioned high-precision automatic detection device for the oil pressure gauge, preferably, the change in the oil cylinder volume is obtained according to the following formula:

[0015]

[0016] In the formula, △V is the volume change; △P is the pressure change; V is the total volume of the cylinder; E is the elastic modulus.

[0017] The change in length of the screw rod is obtained according to the following formula:

[0018]

[0019] Where x is the change in length of the screw rod; △V is the change in volume; D is the diameter of the cylinder.

[0020] The motor rotation angle is obtained according to the following formula:

[0021]

[0022] Where, Q is the motor rotation angle; x is the screw rod length; B is the reduction ratio; L is the screw pitch.

[0023] In the aforementioned high-precision automatic detection device for oil pressure gauge, as a preferred method, after the detection is completed, the product to be tested is removed, and the data is read and the error is calculated, and whether it is qualified is determined according to the error value, wherein:

[0024] The parameters compared are: standard pressure and measured pressure.

[0025] Error calculation: Return error = (second reading - first reading) / full scale × 100%.

[0026] Allowable error: maximum range of standard table ± accuracy grade.

[0027] This technical solution is mainly designed from the following aspects:

[0028] First, in terms of hardware structure, it is mainly composed of three parts: cylinder assembly, screw assembly and driving mechanism. The cylinder assembly is used for oil source injection and output. Its external cylinder is connected to the first bell-shaped cover, and the internal oil rod is connected to the sleeve in the first bell-shaped cover. The sleeve is connected to the screw in the screw assembly. The screw is powered by the driving device, thus forming a linkage mechanism with high adjustment accuracy and wide adjustment range. In this device, a limit plate is provided on the sleeve, and a proximity switch is provided on the screw assembly to ensure that each component moves safely within the set length.

[0029] Second, in terms of software design, the proximity switch, motor and PLC control system of this device are connected. The internal relationship between the change in cylinder volume, the change in lead screw length and the motor rotation angle is obtained through calculation. The measured pressure value of the tested product is read by the computer, and then the parameters are compared and the error is calculated. The high-resolution servo motor controls the high-precision reduction motor to drive the lead screw to move linearly. That is, when the pressure change value is required, the change in cylinder volume can be accurately controlled, and the stroke of the oil rod movement can be obtained from the volume change through the constant cross-sectional area of ​​the cylinder, and then the rotation angle of the servo motor can be obtained.

[0030] Compared with the prior art, the beneficial effects of the present invention are: low cost and low complexity of machining are achieved through high-precision hardware cylinder components, screw components and drive mechanisms that are easily obtained through conventional manufacturing processes, with components and connectors with simpler structures; automatic detection and control of the pressure gauge is achieved through a high-precision, high-efficiency and automated computer control system; high-precision regulation, high resolution, wide pressure regulation range, fast response, and pressure regulation linearity are achieved through the control system. BRIEF DESCRIPTION OF THE DRAWINGS

[0031] Figure 1 It is a structural schematic diagram of the present invention.

[0032] Figure 2 It is a schematic diagram of the internal structure of the present invention.

[0033] Figure 3 yes Figure 2 Schematic diagram of the partial enlarged structure of the middle cylinder component.

[0034] Figure 4 Figure 2 A schematic diagram of the partially enlarged structure of the middle screw assembly.

[0035] In the figure: 100-cylinder assembly; 101-cylinder; 102-oil rod; 103-first bell; 104-sleeve; 200-screw assembly; 201-bearing seat; 202-proximity switch; 203-limiting plate; 204-second bell; 205-screw; 300-driving mechanism; 301-third bell; 302-coupling; 303-reducer; 304-motor. DETAILED DESCRIPTION

[0036] The technical solution of the present invention is further specifically described below through embodiments and in conjunction with the accompanying drawings.

[0037] This embodiment is a high-precision automatic detection device for an oil pressure gauge, such as Figure 1 As shown, it includes a cylinder assembly 100, a screw assembly 200 and a driving mechanism 300 which are connected in sequence.

[0038] The internal structure of each component is shown in Figures 2 to 4 The oil cylinder assembly includes an oil cylinder 101 for oil source injection and output, an oil rod 102 is arranged in the oil cylinder 101, the tail end of the oil cylinder 101 is connected to a first bell-shaped cover 103 through a flange structure, a sleeve 104 connected to the oil rod 102 is arranged in the first bell-shaped cover 103, and the end of the sleeve 104 extends into one end of the second bell-shaped cover 204 and is provided with a limit plate 203.

[0039] A second bell-shaped cover 204 is provided on the outside of the screw assembly 200, and the screw 205 is positioned and fixed inside the second bell-shaped cover 204 through bearing seats 201 located at both ends thereof. Two proximity switches 202 are provided on the second bell-shaped cover 204 in the screw assembly 200, and the two proximity switches 202 cooperate with the limit plates 203.

[0040] Specifically, the second bell-shaped cover 204 is provided with a proximity switch 202 base, and the proximity switch 202 base is provided with a through hole adapted to the proximity switch 202, and the limit plate 203 passes through the through hole, and induction is generated when the limit plate 203 contacts the proximity switch 202. The proximity switch 202 is connected to the PLC control system through a cable.

[0041] The driving mechanism 300 includes a servo motor 304, which is connected to a reducer 303. The reducer 303 has a 90-degree reversing helical gear set to reduce the length occupation in the length direction. The reducer 303 is connected to the screw rod 205 through a coupling 302. The proximity switch 202 is connected to the PLC control system through a cable.

[0042] Furthermore, a third bell-shaped housing 301 is arranged between the screw assembly 200 and the driving device 300, and the third bell-shaped housing 301 is connected to the second bell-shaped housing 204 through a flange structure. Similarly, the first bell-shaped housing 103 is also connected to the second bell-shaped housing 204 through a flange structure. A groove is provided on the upper part of the first bell-shaped housing 103, and the bearing seat 201 cooperates with the groove to serve as a positioning body to eliminate its degree of freedom.

[0043] One end of the sleeve 104 is connected to the oil rod 102, and the other end is connected to the screw 205; a guide groove is provided on the sleeve 104 to ensure that when the screw 205 slides and drives the sleeve 104 to move linearly, it avoids interference with the installed bearing seat 201; the end surface of the sleeve 104 connected to the oil rod is matched through a countersunk shaft-wrapped fit, and 6 M8 cylindrical head countersunk screws are used to fix the screw 205 and the sleeve 104 during assembly.

[0044] The above-mentioned connection structures are fixed by screws, and the strength grade of the screws is at least 12.9.

[0045] A through hole is also provided on the upper part of the third bell-shaped cover 301, which can be used as an observation hole to observe the installation condition of the coupling 302 and the movement state of the reducer during movement. It can also reduce the weight of the third bell-shaped cover 301, reduce the force requirements of the connecting parts, and reduce the weight of the device.

[0046] Further, the change in cylinder volume is obtained according to the following formula:

[0047]

[0048] In the formula, △V is the volume change; △P is the pressure change; V is the total volume of the cylinder; E is the elastic modulus;

[0049] The change in length of the screw rod is obtained according to the following formula:

[0050]

[0051] Where x is the change in length of the screw rod; △V is the change in volume; D is the diameter of the cylinder.

[0052] The motor rotation angle is obtained according to the following formula:

[0053]

[0054] Where, Q is the motor rotation angle; x is the screw rod length; B is the reduction ratio; L is the screw pitch.

[0055] The following is a calculation of the volume change of the oil in the cylinder when the pressure increases by 0.01MPa, based on the conditions of 0-40MPa pressure and 0-0.37L / min flow rate:

[0056] 1. Volume change △V:

[0057]

[0058] Where: △P-pressure change, 0.01MPa; V-total volume of the cylinder, 110mL; E-elastic modulus, 1200MPa.

[0059] 2. Screw rod change length x:

[0060]

[0061] Where: △V-volume change; D-cylinder diameter, 2.5cm.

[0062] 3. Motor rotation angle Q:

[0063]

[0064] Where: x-screw rod change length, 1.867×10 -3 ; B-reduction ratio, 20; L-pitch, 6mm.

[0065] Sample test process:

[0066] Turn on the power supply and turn on the measurement and control system. The motor 304 drives the reducer 303 to rotate forward through the coupling 302, which drives the screw assembly 200 to move to the right (in the direction of the motor 304). At this time, the limit plate 203 moves between the two proximity switches 202. When the limit plate 203 is close to the proximity switch 202, the motor 304 stops rotating, and the screw assembly 200 drives the sleeve 104 to move linearly to the right. At the same time, the oil rod 102 connected to the sleeve 104 moves linearly to the right. Through the interface at the front end of the cylinder 101, the oil is sucked into the cylinder 101 from the oil source system until the cylinder 101 is filled with oil.

[0067] Open the ball valve at the product to be tested, and the motor 304 reverses to drive the reducer 303 to drive the screw assembly 200 to move to the left (towards the cylinder 101) through the coupling 302. The screw 205 drives the sleeve 104 to move linearly to the left. At the same time, the sleeve 104 drives the oil rod 102 to move linearly to the left. When the pressure of the oil in the cylinder 101 (pressure 0-40MPa, flow rate 0-0.37L / min) increases by 0.01MPa, the volume change of the cylinder 101 is 9.167X10-4mL, and the rotation degree of the motor 304 is 2.241°.

[0068] After the test is completed, pump the oil of the product to be tested back into the oil tank and close the high-pressure ball valve at the product. Remove the product to be tested and calculate its error through the read data. If the error is within the specified range, the pressure gauge to be tested is qualified.

[0069] Furthermore, in this embodiment, the PLC control system reads the data, calculates its error, and then determines whether it is qualified according to the error value, wherein:

[0070] The parameters compared are: standard pressure and measured pressure.

[0071] Error calculation: Return error = (second reading - first reading) / full scale × 100%.

[0072] Allowable error: maximum range of standard table ± accuracy grade.

[0073] In this embodiment, a high-resolution (24-bit) servo motor 304 controls a high-precision (3 arcmin) reducer to drive the lead screw 205 to move linearly, and then drives the intermediate connecting piece to move.

[0074] When a certain pressure change value (0-40MPa) is required, the volume change △V of the cylinder 101 can be accurately controlled. The volume change △V is used to obtain the stroke of the oil rod 102 through the constant cross-sectional area of ​​the cylinder 101, and then the rotation angle Q of the servo motor 304 is obtained, which is calculated by the movement stroke of the oil rod 102, the reduction ratio B of the reducer 205 and the pitch of the screw 205.

[0075] The above embodiments are for explanation of the present invention, not for limitation of the present invention, and the described embodiments are only a part of the embodiments of the present invention, not all of the embodiments. Based on the embodiments of the present invention, all other embodiments obtained by ordinary technicians in this field without creative work are within the scope of protection of the present invention.

Claims

1. A high-precision automatic detection device for an oil pressure gauge, comprising a cylinder assembly (100), a screw assembly (200) and a drive mechanism (300) connected in sequence, characterized in that The oil cylinder assembly comprises an oil cylinder (101) for injecting and outputting oil, an oil rod (102) arranged in the oil cylinder, a first bell-shaped cover (103) connected to the rear end of the oil cylinder, a sleeve (104) connected to the oil rod arranged in the first bell-shaped cover, and a limit plate (203) arranged on the sleeve (104); A second bell-shaped cover (204) is provided outside the screw rod assembly, the screw rod (205) is positioned inside the second bell-shaped cover through a bearing seat (201), and the screw rod assembly is provided with two proximity switches (202); The driving mechanism comprises a motor (304), and the proximity switch and the motor are connected to a PLC control system.

2. The high-precision automatic detection device for oil pressure gauge according to claim 1 is characterized in that: The second bell-shaped cover (204) is provided with a proximity switch base, the proximity switch base is provided with a through hole adapted to the proximity switch (202), the limit plate (203) passes through the through hole, and induction is generated when the limit plate contacts the proximity switch.

3. The high-precision automatic detection device for oil pressure gauge according to claim 1 is characterized in that The driving mechanism (300) further comprises a reducer (303), and the screw rod (205) is connected to the reducer (303) via a coupling (302).

4. The high-precision automatic detection device for oil pressure gauge according to claim 3 is characterized in that: A third bell-shaped housing (301) is provided between the screw rod assembly (200) and the driving device (300), and the third bell-shaped housing is connected to the second bell-shaped housing (204) as a whole.

5. The high-precision automatic detection device for oil pressure gauge according to claim 1, characterized in that: One end of the first bell-shaped cover (103) is connected to the oil cylinder (101) via a flange structure, and the other end of the first bell-shaped cover is connected to the second bell-shaped cover (204); a groove is provided on the upper part of the first bell-shaped cover, and the bearing seat (201) cooperates with the groove.

6. The high-precision automatic detection device for oil pressure gauge according to claim 1 is characterized in that: One end of the sleeve (104) is connected to the oil rod (102), and the other end of the sleeve is connected to the screw rod (205). A guide groove is provided on the sleeve, and the end surface where the sleeve is connected to the oil rod is matched in a countersunk shaft-wrapped manner.

7. The high-precision automatic detection device for oil pressure gauge according to claim 1, characterized in that: The change in cylinder volume is obtained according to the following formula: In the formula, △V is the volume change; △P is the pressure change; V-total volume of the oil cylinder; E-elastic modulus; The change in length of the screw rod is obtained according to the following formula: In the formula, x is the length of the screw rod; △V is the volume change; D is the diameter of the cylinder; The motor rotation angle is obtained according to the following formula: Where, Q is the motor rotation angle; x is the screw rod length; B is the reduction ratio; L is the screw pitch.

8. The high-precision automatic detection device for an oil pressure gauge according to claim 1 or 7, characterized in that: After the test is completed, remove the product to be tested, read the data, calculate its error, and determine whether it is qualified based on the error value, where: The parameters compared are: standard pressure and measured pressure; Error calculation: return error = (second reading - first reading) / full scale × 100%; Allowable error: maximum range of standard table ± accuracy grade.

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