Device and method for detecting mixing uniformity of epoxy resin filler

Abstract

The present invention relates to the technical field of epoxy resin composite material casting, and discloses a device and method for detecting the mixing uniformity of epoxy resin filler, comprising a container, a stirring mechanism, a control system and one or more ultrasonic components; the ultrasonic component comprises a transmitting probe and a receiving probe for collecting ultrasonic signals emitted by the transmitting probe in the same component, the transmitting probe and the receiving probe are both arranged on the inner peripheral wall of the container, and the transmitting probe and the receiving probe are symmetrically arranged about the central axis of the container, the stirring mechanism is arranged inside the container, and is used to stir the epoxy resin filler, the stirring mechanism and the ultrasonic component are not at the same horizontal position in the container, and the control system is used to control the transmitting probe to emit ultrasonic signals and obtain the ultrasonic signal information collected by the receiving probe. The present invention realizes the detection of the mixing uniformity of the epoxy resin filler by using the transmitting probe and the receiving probe to cooperate with each other.

Description

Technical Field

[0001] The invention relates to the technical field of epoxy resin composite material casting, in particular to a device and a method for detecting epoxy resin filler mixing uniformity. Background Art

[0002] my country's national economy is in a stage of rapid development. During this stage, the national demand for electricity is increasing, and electric energy has become an indispensable part of production and life. However, my country's energy structure is unevenly distributed. The energy center is in the western region and the load center is mainly located in the southwestern coastal area. Therefore, under the background of West-East Power Transmission, UHV transmission projects are developing and constructing at a high speed. UHV transmission projects have the characteristics of high voltage level and long transmission distance. The use of power components such as insulators and bushings is indispensable in the process of erection. Epoxy resin composite materials are widely used in key components of power equipment due to their excellent insulation properties, stable chemical stability and easy manufacturing. For example, basin-type / three-pillar insulators, insulating bushings and insulating pull rods.

[0003] As the main material for manufacturing many key components of power equipment, the characteristics of epoxy resin composite materials are directly related to the mechanical and insulation properties of the components. Once a problem occurs, it is very likely to cause an accident, thus threatening the safe and stable operation of the power system. The mechanical and insulation properties of epoxy resin composite materials are affected by the uniformity of the epoxy resin filler mixing. Uneven mixing of epoxy resin fillers will form degraded areas or even defects during the curing process, causing mechanical insulation failure of power equipment due to the combined action of electric field and force field during operation, seriously affecting the normal operation of power equipment. Therefore, the mixing uniformity of epoxy resin fillers is particularly important. In order to prevent the existence of hidden dangers, relevant tests should be carried out. Summary of the invention

[0004] The purpose of the present invention is to design a device for detecting the mixing uniformity of epoxy resin fillers, which realizes the detection of the mixing uniformity of epoxy resin fillers by using a transmitting probe and a receiving probe to cooperate with each other.

[0005] In order to achieve the above-mentioned purpose, the present invention provides a device for detecting the mixing uniformity of epoxy resin filler, comprising a container, a stirring mechanism, a control system and one or more ultrasonic components; the ultrasonic component comprises a transmitting probe and a receiving probe for collecting ultrasonic signals emitted by the transmitting probe in the same component, the transmitting probe and the receiving probe are both arranged on the inner circumferential wall of the container, and the transmitting probe and the receiving probe are symmetrically arranged about the central axis of the container, the stirring mechanism is arranged inside the container, and is used to stir the epoxy resin filler, the stirring mechanism and the ultrasonic component are not at the same horizontal position in the container, the control system is respectively communicated with the receiving probe and the transmitting probe, and the control system is used to control the transmitting probe to emit ultrasonic signals and obtain the ultrasonic signal information collected by the receiving probe.

[0006] Preferably, the top of the container has an open mouth, the stirring mechanism includes a stirring impeller, the stirring impeller extends from the open mouth into the interior of the container to stir the epoxy resin filler, and the ultrasonic component is located below the stirring impeller.

[0007] Preferably, at least three ultrasonic components are included, each of which is evenly distributed along the circumferential direction on the inner circumferential wall of the container, and the ultrasonic frequencies generated by the transmitting probes in each of the ultrasonic components are different.

[0008] Preferably, it further comprises a heating mechanism, wherein the heating mechanism is provided with a groove matched with the shape of the container, and the container is installed in the groove.

[0009] Preferably, the groove is located in a central area of ​​the heating mechanism.

[0010] The present invention also provides a method for detecting the mixing uniformity of epoxy resin fillers, comprising the following steps:

[0011] S1 injects epoxy resin filler into the container and heats the epoxy resin filler;

[0012] S2 stirs the epoxy resin filler in the container, and at the same time controls each transmitting probe to emit an ultrasonic signal through a control system and obtains ultrasonic signal information collected by each receiving probe, wherein the ultrasonic signal information includes longitudinal wave speed and / or ultrasonic energy;

[0013] S3 determines whether the longitudinal wave velocity and / or the ultrasonic energy are within a preset relationship table, wherein the relationship table records the longitudinal wave velocity range and / or ultrasonic energy range of the standard sample. If the longitudinal wave velocity and / or the ultrasonic energy are within the relationship table, it indicates that the epoxy resin filler has been mixed evenly.

[0014] Preferably, the stirring of the epoxy resin filler in the container specifically includes:

[0015] The epoxy resin filler is stirred by a stirring impeller of the stirring mechanism, and the rotation speed of the stirring impeller is 50 r / min to 400 r / min.

[0016] Preferably, controlling each transmitting probe to emit an ultrasonic signal and acquiring ultrasonic signal information collected by each receiving probe through a control system specifically includes:

[0017] The frequency of the ultrasonic signal emitted by each transmitting probe is 20MHz to 100MHz, and the frequency of the ultrasonic signal emitted by the transmitting probe of each ultrasonic component is different.

[0018] Preferably, the step of heating the epoxy resin filler specifically comprises:

[0019] The container is heated by a heating mechanism, and the heating temperature of the heating mechanism is 70°C to 150°C.

[0020] Preferably, the mixing uniformity of the epoxy resin filler is quantitatively judged according to the longitudinal wave velocity in the collected ultrasonic signal information, and the specific judgment method is as follows:

[0021] When ultrasonic waves are propagating, they are determined by the elastic modulus E, Poisson's ratio σ and medium density ρ. The specific formula is as follows:

[0022]

[0023] The elastic modulus E and Poisson's ratio σ are usually affected by the Lame constant λ′ and μ. The specific formula is as follows:

[0024]

[0025]

[0026] Substituting formula (2) (3) into formula (1), the formula for calculating medium density ρ is as follows:

[0027]

[0028] Among them, c L is the longitudinal wave speed, λ′ and μ are the Lame constants.

[0029] The medium density value is obtained based on the collected longitudinal wave sound velocity and formula (4), so as to quantitatively judge the impurity content in the epoxy resin filler.

[0030] Compared with the prior art, the device and method for detecting the mixing uniformity of epoxy resin fillers in the embodiment of the present invention have the following beneficial effects:

[0031] The device and method for detecting the mixing uniformity of epoxy resin fillers in the embodiments of the present invention cooperate with each other in the transmitting probe and the receiving probe directly opposite to it in the same component. The control system obtains ultrasonic signal information such as longitudinal wave sound velocity and ultrasonic energy collected by the receiving probe, and detects and judges the mixing uniformity of the epoxy resin filler in combination with a preset relationship table. This can avoid uneven mixing of the epoxy resin filler, prevent performance degradation of the cured epoxy resin composite material, and ensure safe and stable operation of the power equipment. BRIEF DESCRIPTION OF THE DRAWINGS

[0032] Figure 1 is a schematic structural diagram of a device for detecting mixing uniformity of epoxy resin fillers according to an embodiment of the present invention;

[0033] Figure 2 2 is a schematic diagram of the structure of an ultrasonic component of a device for detecting mixing uniformity of epoxy resin fillers according to an embodiment of the present invention;

[0034] Figure 3 It is a schematic diagram of the refraction and reflection of ultrasonic waves in the medium;

[0035] Figure 4 It is a schematic diagram of the refraction and reflection of ultrasound in multiple media.

[0036] In the figure, 1. container; 11. open mouth; 2. stirring mechanism; 21. stirring impeller; 3. control system; 4. ultrasonic component; 41. transmitting probe; 42. receiving probe; 5. heating mechanism; 51. groove. DETAILED DESCRIPTION

[0037] The specific implementation of the present invention is further described in detail below in conjunction with the accompanying drawings and examples. The following examples are used to illustrate the present invention, but are not intended to limit the scope of the present invention.

[0038] In the description of the present invention, it should be understood that the terms "up", "down", "front", "back", "left", "right", "vertical", "horizontal", "top", "bottom", "inside" and "outside" used in the present invention to indicate the orientation or position relationship are based on the orientation or position relationship shown in the accompanying drawings, and are only for the convenience of describing the present invention and simplifying the description, rather than indicating or implying that the device or element referred to must have a specific orientation, be constructed and operated in a specific orientation, and therefore cannot be understood as a limitation on the present invention.

[0039] In the description of the present invention, it should be understood that the terms "connected", "connected", "fixed" and the like used in the present invention should be understood in a broad sense, for example, it can be a fixed connection, a detachable connection, or an integral connection; it can be a mechanical connection or a welding connection; it can be directly connected or indirectly connected through an intermediate medium, it can be the internal connection of two elements or the interaction relationship between two elements, unless otherwise clearly defined. For ordinary technicians in this field, the specific meanings of the above terms in the present invention can be understood according to specific circumstances.

[0040] The present invention uses the terms "first", "second", etc. to describe various information, but these information should not be limited to these terms, and these terms are only used to distinguish the same type of information from each other. For example, without departing from the scope of the present invention, "first" information may also be referred to as "second" information, and similarly, "second" information may also be referred to as "first" information.

[0041] like Figure 1 and Figure 2 As shown, a device for detecting mixing uniformity of epoxy resin filler according to a preferred embodiment of an embodiment of the present invention comprises a container 1, a stirring mechanism 2, a control system 3 and one or more ultrasonic components 4; the ultrasonic component 4 comprises a transmitting probe 41 and a receiving probe 42 for collecting ultrasonic signals emitted by the transmitting probe 41 in the same component, the transmitting probe 41 and the receiving probe 42 are both arranged on the inner circumferential wall of the container 1, and the transmitting probe 41 and the receiving probe 42 are symmetrically arranged about the central axis of the container 1, the stirring mechanism 2 is arranged inside the container 1, and is used to stir the epoxy resin filler, the stirring mechanism 2 and the ultrasonic component 4 are not at the same horizontal position in the container 1, the control system 3 is respectively communicated with the receiving probe 42 and the transmitting probe 41, and the control system 3 is used to control the transmitting probe 41 to emit ultrasonic signals and obtain the ultrasonic signal information collected by the receiving probe 42.

[0042] Among them, the transmitting probe 41 and the receiving probe 42 in the same ultrasonic component 4 are arranged in pairs and are flush with each other in the container 1. The receiving probe 42 only collects the ultrasonic signal emitted by the matching transmitting probe 41, and the frequency ranges set by the two are consistent to ensure the collection of ultrasonic signals. The container 1 is preferably a steel structure, preferably stainless steel, which has certain advantages such as corrosion resistance and high strength, and can adapt to the actual working environment. The preferred internal dimensions of the container 1 are 200mm high, 200mm inner diameter, 2mm wall thickness, and 304L, which can accommodate a certain volume of epoxy material to meet the detection of epoxy materials of different capacities. The stirring mechanism 2 is not at the same horizontal position as the ultrasonic component 4 to prevent the stirring mechanism 2 from affecting the transmission of the ultrasonic signal. The control system 3 is used to analyze and process the signals collected by the receiving probe 42 to obtain the mixing uniformity.

[0043] Furthermore, the top of the container 1 has an open mouth 11, the stirring mechanism 2 includes a stirring impeller 21, the stirring impeller 21 extends from the open mouth 11 into the interior of the container 1 for stirring the epoxy resin filler, and the ultrasonic component 4 is located below the stirring impeller 21.

[0044] The stirring impeller 21 is arranged at the center of the container 1, and the stirring mechanism 2 includes a rotating motor, which drives the stirring impeller 21 to rotate, and the speed is constant and adjustable, and the speed range of the stirring impeller 21 is 50r / min-400r / min. The stirring impeller 21 is used to stir the internal epoxy resin filler during detection, so that the stirring process is uniform and the speed is constant, ensuring that each part of the epoxy resin filler in the container 1 can be detected. Due to the short detection time, the influence of the stirring impeller 21 on the uniformity of the epoxy resin filler can be ignored.

[0045] Furthermore, at least three ultrasonic components 4 are included, each of which is evenly distributed along the circumferential direction on the inner circumferential wall of the container 1, and the ultrasonic frequencies generated by the transmitting probes 41 in each ultrasonic component 4 are different, thereby ensuring the wide range of detection areas of the ultrasonic components 4. The frequency range of the ultrasonic signal emitted by the transmitting probe 41 and the ultrasonic signal collected by the receiving probe 42 is 20MHz-100MHz.

[0046] Furthermore, a heating mechanism 5 is included, and the heating mechanism 5 is provided with a groove 51 adapted to the shape of the container 1, and the container 1 is installed in the groove 51. The temperature range of the heating mechanism is 0-200°C, which can be adjusted according to actual needs. In this embodiment, the preset temperature is 110°C during use.

[0047] Furthermore, the groove 51 is located in the central area of ​​the heating mechanism 5. The groove 51 is located in the central area and can perfectly fit with the container 1, ensuring that the container 1 is evenly heated during heating. The heating mechanism 5 can be a heating sleeve, and its specific structure and function are all existing technologies and will not be elaborated in detail here.

[0048] The preferred embodiment of the present invention also includes a method for detecting the mixing uniformity of epoxy resin filler, comprising the following steps:

[0049] S1 injects epoxy resin filler into container 1 and heats the epoxy resin filler;

[0050] S2 stirs the epoxy resin filler in the container 1, and at the same time controls each transmitting probe 41 to emit an ultrasonic signal and obtains ultrasonic signal information collected by each receiving probe 42 through the control system 3, wherein the ultrasonic signal information includes longitudinal wave speed and / or ultrasonic energy;

[0051] S3 determines whether the longitudinal wave velocity and / or the ultrasonic energy are within a preset relationship table, wherein the relationship table records the longitudinal wave velocity range and / or ultrasonic energy range of the standard sample. If the longitudinal wave velocity and / or the ultrasonic energy are within the relationship table, it indicates that the epoxy resin filler has been mixed evenly.

[0052] The uniformly mixed epoxy resin filler standard sample is tested in the container 1 in advance, and the control system 3 records the data such as the longitudinal wave velocity and ultrasonic energy collected by the receiving probe 42, and generates a preset relationship table in combination with a reasonable error range.

[0053] Generally, if the epoxy resin filler is not mixed evenly, there will be air gaps and other impurities inside. Due to the difference in the medium properties of the epoxy resin filler and the gas, the ultrasonic wave will be refracted and reflected during the process. Figure 3 As shown. At the same time, during this process, the ultrasonic wave will be attenuated, which will have a relevant impact on the longitudinal wave speed, ultrasonic wave energy, etc.

[0054] When the collected longitudinal wave velocity and ultrasonic wave energy are not within the preset relationship table, it means that the mixing uniformity of the epoxy resin filler is not enough.

[0055] Furthermore, the stirring of the epoxy resin filler in the container 1 specifically includes:

[0056] The epoxy resin filler is stirred by the stirring impeller 21 of the stirring mechanism 2, and the rotation speed of the stirring impeller 21 is 50r / min to 400r / min. It is used to stir the epoxy resin filler in the container 1 to ensure that the detection can evenly collect information from various areas of the epoxy resin filler and ensure the accuracy of the detection result.

[0057] Furthermore, the control system 3 controls each transmitting probe 41 to emit an ultrasonic signal and obtains the ultrasonic signal information collected by each receiving probe 42, specifically including:

[0058] The frequency of the ultrasonic signal emitted by each transmitting probe 41 is 20 MHz to 100 MHz, and the frequency of the ultrasonic signal emitted by the transmitting probe 41 of each ultrasonic component 4 is different, thereby ensuring the extensiveness of the detection area.

[0059] Furthermore, the step of heating the epoxy resin filler specifically includes:

[0060] The container 1 is heated by the heating mechanism 5 , and the heating temperature of the heating mechanism 5 is 70° C. to 150° C. The preferred heating temperature is 110° C.

[0061] Furthermore, the mixing uniformity of the epoxy resin filler is quantitatively judged according to the longitudinal wave sound velocity in the collected ultrasonic signal information, and the specific judgment method is as follows:

[0062] When ultrasonic waves are propagating, they are determined by the elastic modulus E, Poisson's ratio σ and medium density ρ. The specific formula is as follows:

[0063]

[0064] The elastic modulus E and Poisson's ratio σ are usually affected by the Lame constant λ' and μ. The specific formula is as follows:

[0065]

[0066]

[0067] Substituting formula (2) (3) into formula (1), the formula for calculating medium density ρ is as follows:

[0068]

[0069] Among them, c L is the longitudinal wave speed, λ' and μ are both Lame constants;

[0070] The medium density value is obtained based on the collected longitudinal wave sound velocity and formula (4), so as to quantitatively judge the impurity content in the epoxy resin filler.

[0071] like Figure 4 As shown in the figure, when the internal distribution is more uneven, there may be bubble interlayers inside, and the medium distribution is more complicated. When there are multiple layers of different media, the ultrasonic wave will be refracted and reflected multiple times in this interface, and the attenuation of the ultrasonic wave is more obvious.

[0072] The specific reasons are as follows: Since the longitudinal wave speed affects the propagation time of the ultrasonic wave in the container 1, the change of the longitudinal wave speed is crucial in the process of information analysis after the ultrasonic signal is collected. L Determined by the elastic modulus E, Poisson's ratio σ and medium density ρ, the specific formula is as follows:

[0073]

[0074] The elastic modulus E and Poisson's ratio σ are usually affected by the Lame constant λ' and μ. The specific formula is as follows:

[0075]

[0076]

[0077] Finally, the longitudinal wave speed c can be obtained by combining formulas (1), (2), and (3): L The calculation formula is as follows:

[0078]

[0079] The calculation formula of the converted medium density ρ is as follows:

[0080]

[0081] Among them, c L is the longitudinal wave speed, λ' and μ are the Lame constants.

[0082] In addition to the longitudinal wave speed, the acoustic impedance is also closely related to the medium density during the radiation and refraction of ultrasonic waves. Therefore, the acoustic impedance can also be used as one of the important detection parameters during the detection process. The specific formula is as follows:

[0083] Z=ρc (6)

[0084] Among them, Z represents the acoustic impedance, ρ represents the density, and c represents the longitudinal wave speed.

[0085] In addition, the process of ultrasonic wave propagation in the medium is accompanied by energy loss, and its amplitude and intensity will change during the propagation process. The specific formula is as follows:

[0086] c=λf (7)

[0087] Among them, f represents frequency, λ represents wavelength, and c represents longitudinal wave speed.

[0088] The receiving probe 42 collects the ultrasonic signal information involved in the above formulas (4), (6) and (7) and conducts a comprehensive analysis on it through the control system 3, so as to further make a quantitative judgment on the mixing uniformity of the epoxy resin filler.

[0089] The working process of the present invention is:

[0090] 1. First, the epoxy resin filler is placed in the container 1 to enter the pre-test preparation stage, and then the heating mechanism 5 is turned on and the temperature is set to heat the container 1.

[0091] 2. During the heating process, after setting the speed, the stirring mechanism 2 is turned on to stir the epoxy resin filler through the stirring impeller 21, and the transmitting probe 41 and the corresponding receiving probe 42 are turned on through the control system 3 to collect the ultrasonic signal;

[0092] 3. The acquired ultrasonic signal information is transmitted to the control system 3 for relevant analysis.

[0093] In summary, the embodiment of the present invention provides a device and method for detecting the mixing uniformity of epoxy resin filler. The transmitting probe 41 used therein cooperates with the receiving probe 42 directly opposite thereto in the same component. The control system 3 obtains ultrasonic signal information such as longitudinal wave sound velocity and ultrasonic energy collected by the receiving probe 42, and detects and judges the mixing uniformity of the epoxy resin filler in combination with a preset relationship table. This can avoid uneven mixing of the epoxy resin filler, prevent performance degradation of the cured epoxy resin composite material, and ensure safe and stable operation of the power equipment.

[0094] The above is only a preferred embodiment of the present invention. It should be pointed out that for ordinary technicians in this technical field, several improvements and substitutions can be made without departing from the technical principles of the present invention. These improvements and substitutions should also be regarded as the scope of protection of the present invention.

Claims

1. A device for detecting the mixing uniformity of epoxy resin fillers, It is characterized in that It comprises a container, a stirring mechanism, a control system and one or more ultrasonic components; the ultrasonic component comprises a transmitting probe and a receiving probe for collecting ultrasonic signals emitted by the transmitting probe in the same component, the transmitting probe and the receiving probe are both arranged on the inner peripheral wall of the container, and the transmitting probe and the receiving probe are symmetrically arranged about the central axis of the container, the stirring mechanism is arranged inside the container, and is used to stir the epoxy resin filler, the stirring mechanism and the ultrasonic component are not at the same horizontal position in the container, the control system is respectively connected to the receiving probe and the transmitting probe for communication, and the control system is used to control the transmitting probe to emit ultrasonic signals and obtain the ultrasonic signal information collected by the receiving probe; The top of the container has an open opening, the stirring mechanism includes a stirring impeller, the stirring impeller extends from the open opening into the interior of the container to stir the epoxy resin filler, and the ultrasonic component is located below the stirring impeller; It comprises at least three ultrasonic components, each of which is evenly distributed along the circumference of the inner circumferential wall of the container, and the ultrasonic frequencies emitted by the transmitting probes in each ultrasonic component are different; It also includes a heating mechanism, which is provided with a groove matched with the shape of the container, and the container is installed in the groove.

2. The device for detecting the mixing uniformity of epoxy resin filler according to claim 1, It is characterized in that The groove is located in the central area of ​​the heating mechanism.

3. A method for detecting the mixing uniformity of epoxy resin fillers, applied to the device for detecting the mixing uniformity of epoxy resin fillers as claimed in any one of claims 1 to 2, It is characterized in that The steps include: S1 injects epoxy resin filler into the container and heats the epoxy resin filler; S2 stirs the epoxy resin filler in the container, and at the same time controls each transmitting probe to emit an ultrasonic signal through a control system and obtains ultrasonic signal information collected by each receiving probe, wherein the ultrasonic signal information includes longitudinal wave speed and / or ultrasonic energy; S3 determines whether the longitudinal wave velocity and / or the ultrasonic energy are within a preset relationship table, wherein the relationship table records the longitudinal wave velocity range and / or ultrasonic energy range of the standard sample. If the longitudinal wave velocity and / or the ultrasonic energy are within the relationship table, it indicates that the epoxy resin filler has been mixed uniformly. The controlling of each transmitting probe to emit an ultrasonic signal and obtaining ultrasonic signal information collected by each receiving probe by the control system specifically includes: The frequency of the ultrasonic signal emitted by each transmitting probe is 20MHz~100MHz, and the frequency of the ultrasonic signal emitted by the transmitting probe of each ultrasonic component is different; The heating of the epoxy resin filler specifically comprises: The container is heated by a heating mechanism, wherein the heating temperature of the heating mechanism is 70° C. to 150° C.; The mixing uniformity of the epoxy resin filler is quantitatively judged according to the longitudinal wave sound velocity in the collected ultrasonic signal information, and the specific judgment method is as follows: When ultrasonic waves are propagating, the longitudinal wave speed c L By elastic modulus E , Poisson's ratio And the medium density Determine, the specific formula is as follows: （1） Elastic modulus E, Poisson's ratio Lamé constant as well as The specific formula is as follows: （2） （3） Substituting formula (2) (3) into formula (1) yields the medium density: The calculation formula is as follows: （4） in, c L is the longitudinal wave speed, as well as All are Lamé constants; The medium density value is obtained based on the collected longitudinal wave sound velocity and formula (4), so as to quantitatively judge the impurity content in the epoxy resin filler.

4. The method for detecting the mixing uniformity of epoxy resin filler according to claim 3, It is characterized in that The stirring of the epoxy resin filler in the container specifically comprises: The epoxy resin filler is stirred by a stirring impeller of the stirring mechanism, and the rotation speed of the stirring impeller is 50r / min~400r / min.

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