CN112392800A

CN112392800A - Detection and judgment process method for leakage value of low-leakage hydraulic product

Info

Publication number: CN112392800A
Application number: CN202011289039.1A
Authority: CN
Inventors: 杜君华
Original assignee: Wuxi Smank Automation Technology Co ltd
Current assignee: Wuxi Smank Automation Technology Co ltd
Priority date: 2020-11-18
Filing date: 2020-11-18
Publication date: 2021-02-23

Abstract

The invention provides a detection and judgment process method for a leakage value of a low-leakage hydraulic product, and relates to the field of hydraulic value detection. The detection and judgment process method for the leakage value of the low-leakage hydraulic product comprises an electromagnetic two-way valve, a lithium battery, an air pressure sensor and a hydraulic cylinder, and comprises the following steps: s1, connecting the electromagnetic two-way valve, the lithium battery, the air pressure sensor and the hydraulic cylinder in series; s2: according to the compressibility of oil, converting a certain pressure P0 in a unit cavity into a constant C through Bohr's law PV/T to compress the hydraulic oil in the hydraulic cylinder, and recording the pressure value as P0 through an air pressure sensor; s3: after a certain amount of oil is leaked inside the hydraulic cylinder, the original oil in the accommodating cavity expands, and the pressure is reduced. After the initial calibration, the method is suitable for mass production, the testing process can be fully automated, the judgment is carried out by using a testing program, the interference of human factors is reduced, and the personnel cost is reduced.

Description

Detection and judgment process method for leakage value of low-leakage hydraulic product

Technical Field

The invention relates to the technical field of hydraulic value detection, in particular to a process method for detecting and judging a leakage value of a low-leakage hydraulic product.

Background

The hydraulic cylinder leakage brings a lot of hazards, which is one of the reasons for various faults of the hydraulic cylinder and is an important factor influencing safety and environment pollution, so that sufficient attention should be paid, the hydraulic cylinder leakage includes two situations of external leakage and external leakage, the external leakage refers to external oil leakage at the positions of a cylinder barrel and a cylinder cover of the hydraulic cylinder, a cylinder bottom, an oil port, an exhaust valve, a buffer regulating valve, the cylinder cover, a piston rod and the like, and is easy to be directly observed from the outside, the internal leakage refers to leakage of pressure oil in a high-pressure cavity in the hydraulic cylinder to a low-pressure cavity, the internal leakage occurs at the joint of a piston and the inner wall of the cylinder and the inner hole of the piston and the piston rod, the internal leakage cannot be directly observed, and the reasons for the leakage are mainly poor sealing, poor.

For the leakage measurement of hydraulic products (mainly hydraulic cylinders and valves), the existing national standard and industry experience practice generally adopts a measuring cup or a flowmeter to directly record the leakage amount, the method is direct and clear, the leakage amount is clear at a glance, but some problems also exist, if the leakage is very low, the measuring cup method is inconvenient to operate, the situation that only a few drops are generated in one minute can occur, the leakage value cannot be read by the measuring cup in a short time, the flowmeter method is also the same situation, the leakage amount exceeds the measuring range of the flowmeter when the leakage amount is too low, and the accurate reading cannot be realized.

Disclosure of Invention

Technical problem to be solved

The invention provides a process method for detecting and judging the leakage value of a low-leakage hydraulic product, aiming at overcoming the defects of the prior art, and solving the problems that the leakage of the hydraulic product (mainly a hydraulic cylinder and a valve) is measured, the leakage quantity is directly recorded by a measuring cup or a flowmeter in the prior national standard and industry experience methods, the method is direct and clear, the leakage quantity is clear at a glance, but the method also has some problems, such as the low leakage, the operation of the measuring cup method is inconvenient, the condition that only a few drops are generated in one minute, the leakage value cannot be read by the measuring cup in a short time, the flow meter method is the same condition, the leakage quantity exceeds the measuring range of the flowmeter when the leakage quantity is too low, and the accurate reading cannot be realized.

(II) technical scheme

In order to achieve the purpose, the invention is realized by the following technical scheme: a detection and judgment process method for a leakage value of a low-leakage hydraulic product comprises an electromagnetic two-way valve, a lithium battery, an air pressure sensor and a hydraulic cylinder, and the detection method comprises the following steps:

s1, connecting the electromagnetic two-way valve, the lithium battery, the air pressure sensor and the hydraulic cylinder in series;

s2: according to the compressibility of oil, converting a certain pressure P0 in a unit cavity into a constant C through Bohr's law PV/T to compress the hydraulic oil in the hydraulic cylinder, and recording the pressure value as P0 through an air pressure sensor;

s3: when a certain amount of oil is leaked inside the hydraulic cylinder, the oil in the original cavity expands, the pressure drops, and the recorded value of the air pressure sensor becomes P1;

s4: from the leak value Δ P — P0-P1, the allowable range of the leak value Δ P is determined by initial verification and revision to detect the leak value.

Preferably, the volume of the cavity in S2 is different according to different products, and the specification setting needs to be recalculated.

Preferably, the standard setting and checking in S2 is to stabilize the oil temperature to avoid the influence of temperature on the oil pressure.

Preferably, when the pressure drop method in S2 is used for measuring the cylinder leakage, the leakage amount of the electromagnetic two-way valve needs to be compensated, and meanwhile, because the valve is closed for a time delay, the initial pressure P0 needs to be taken after the pressure in the cavity is stabilized for a period of time, and timing is started at the same time.

Preferably, when the leakage amount in S3 is too large, this test method will not be applicable when the P1 pressure is equal to 0.

(III) advantageous effects

The invention provides a process method for detecting and judging a leakage value of a low-leakage hydraulic product. The method has the following beneficial effects:

1. by the detection and judgment process method for the leakage value of the low-leakage hydraulic product, after initial calibration, the method is suitable for mass production, can realize full automation of the test process, utilizes the test program to judge, reduces the interference of human factors and reduces the personnel cost.

2. According to the detection and judgment process method for the leakage value of the low-leakage hydraulic product, after a certain pressure P0 is introduced, whether the hydraulic product leaks can be judged according to whether the pressure P0 in the cavity drops.

Drawings

FIG. 1 is a flow chart of the structure of the hydraulic oil cylinder detection device of the invention.

Detailed Description

The technical solutions in the embodiments of the present invention will be clearly and completely described below with reference to the drawings in the embodiments of the present invention, and it is obvious that the described embodiments are only a part of the embodiments of the present invention, and not all of the embodiments. All other embodiments, which can be derived by a person skilled in the art from the embodiments given herein without making any creative effort, shall fall within the protection scope of the present invention.

Example (b):

as shown in fig. 1, an embodiment of the present invention provides a process method for detecting and determining a leakage value of a low-leakage hydraulic product, including an electromagnetic two-way valve, a lithium battery, an air pressure sensor, and a hydraulic cylinder, and is characterized in that: the detection method comprises the following steps:

The volume of the chamber in S2 is different according to the product, and the specification setting needs to be recalculated.

In the standard setting and checking process of S2, the oil temperature needs to be stabilized, and the influence of the temperature on the oil pressure is avoided.

When the pressure drop method in the step S2 is used for measuring the oil cylinder leakage, the leakage amount of the electromagnetic two-way valve needs to be compensated, and meanwhile, because the valve is closed for a delay, the initial pressure P0 needs to be taken after the pressure in the cavity is stabilized for a period of time, and timing is started at the same time.

When the leakage amount in S3 is too large, the test method is not applicable when the P1 pressure is equal to 0.

Although embodiments of the present invention have been shown and described, it will be appreciated by those skilled in the art that changes, modifications, substitutions and alterations can be made in these embodiments without departing from the principles and spirit of the invention, the scope of which is defined in the appended claims and their equivalents.

Claims

1. The utility model provides a detection method to leakage value of low leakage hydraulic product, includes electromagnetism two-way valve and lithium cell and baroceptor and pneumatic cylinder, its characterized in that: the detection method comprises the following steps:

2. The method of claim 1, wherein the method further comprises the steps of: the volume of the cavity in S2 is different according to the product, and the specification setting needs to be recalculated.

3. The method of claim 1, wherein the method further comprises the steps of: and in the standard setting and checking process of S2, the oil temperature needs to be stabilized, so that the influence of the temperature on the oil pressure is avoided.

4. The method of claim 1, wherein the method further comprises the steps of: when the pressure drop method in the S2 is used for measuring the leakage of the oil cylinder, the leakage amount of the electromagnetic two-way valve needs to be compensated, and meanwhile, due to the valve closing delay, the initial pressure P0 needs to be taken after the pressure in the cavity is stable for a period of time, and timing is started at the same time.

5. The process of detecting and determining the leak value of a low leak hydraulic product of claim 1, wherein: when the amount of leakage in S3 is too large, this test method will not work when the P1 pressure is equal to 0.