Capacitive mold flow sensor system embedded in mold and implementation method

Abstract

The invention discloses a capacitive mold flow sensor system embedded in a mold and an implementation method. The capacitive mold flow sensor system comprises metal polar plates embedded in an upper mold and a lower mold, and parallel-plate capacitors corresponding to the mounting positions of the metal polar plates one by one are formed; the electrifying circuit is used for conducting electricity to the metal polar plate; the capacitance information converter is connected with the metal polar plate and is used for measuring the capacitance value of the parallel-plate capacitor formed by the electrified metal polar plate; the information processing module is connected with the capacitance information converter; the capacitance information converter is used for measuring a capacitance value formed by each parallel-plate capacitor, and the information processing module is used for generating a capacitance value change curve of all parallel-plate capacitors after a material medium is poured into a mold cavity; the mold flow sensor system for measuring the flowing direction of the material medium in the mold cavity is constructed, the flowing direction and position of the material medium are determined according to the sequence of capacitance value changes of the parallel-plate capacitors at different positions, and the mold flow sensor system has the advantages of being high in detection precision, long in service life and the like.

Description

Technical Field

[0001] The present invention relates to the field of sensor technology, and in particular to a capacitive mold flow sensor system embedded in a mold and an implementation method thereof. Background Art

[0002] High-pressure resin transfer molding, referred to as HP-RTM molding process, refers to the use of high pressure to mix and inject resins into a vacuum-tight mold pre-laid with fiber-reinforced materials and pre-set inserts, and obtain composite products through resin flow filling, impregnation, curing and demolding. Due to the closed mold molding characteristics of the HP-RTM process, it is impossible to directly observe the resin flow conditions in the mold cavity, resulting in difficult process optimization and high trial and error costs. Mold flow monitoring through sensors is an important means to predict HP-RTM process defects and optimize process parameters.

[0003] Existing mold flow monitoring methods mainly use sensors embedded in the fiber preform, collect data returned by the sensors through special data acquisition equipment, process them through data analysis software, and convert the returned data into information on the resin flow state.

[0004] At present, mold flow monitoring uses many sensors pre-embedded in fiber preforms. Due to the long-term high-temperature working environment, the current sensors have a short life and are consumed quickly, which may have a serious impact on product performance. Summary of the invention

[0005] The purpose of the present invention is to provide a capacitive mold flow sensor system embedded in a mold and an implementation method to solve the technical problems in the prior art that the sensor has a low survival rate and is consumed quickly, and may have a serious impact on product performance.

[0006] In order to solve the above technical problems, the present invention specifically provides the following technical solutions:

[0007] A capacitive mold flow sensor system embedded in a mold, comprising:

[0008] The metal plates are embedded in the upper mold and the lower mold to form parallel plate capacitors corresponding to the installation positions of the metal plates;

[0009] A power circuit connected to the metal plate, the power circuit being used to conduct electricity to the metal plate;

[0010] A capacitance information converter connected to the metal plate, the capacitance information converter is used to measure the capacitance value of the parallel plate capacitor formed by the metal plate after being energized;

[0011] An information processing module connected to the capacitance information converter;

[0012] The capacitance information converter is used to measure the capacitance value formed by each of the parallel plate capacitors, and the information processing module is used to record the capacitance value changes of all parallel plate capacitors and generate a curve.

[0013] As a preferred solution of the present invention, all the metal plates in the upper mold and the lower mold are respectively in the same plane, and the distances between every two corresponding metal plates on the upper mold and the lower mold are the same;

[0014] When the upper mold and the lower mold are closed, each installation position of the metal plate forms a parallel plate capacitor.

[0015] As a preferred solution of the present invention, the upper mold and the lower mold are provided with grooves for installing the metal plate, and when the upper mold and the lower mold are made of metal, an insulating plate is provided between the metal plate and the upper mold, and an insulating plate is also provided between the metal plate and the lower mold;

[0016] A plurality of rows of the metal plates are sequentially arranged on the plane formed by the grooves in the upper mold and the lower mold, and each of the metal plates is marked and distinguished in sequence.

[0017] As a preferred solution of the present invention, the lower mold and the upper mold are provided with grooves for installing the metal plate;

[0018] The spacing between all metal plates in the upper mold and the lower mold is the same, and the side surface areas of all metal plates are the same. The metal plates corresponding to each other at every two positions in the upper mold and the lower mold form a parallel plate capacitor.

[0019] As a preferred solution of the present invention, a timer is provided in the information processing module, and when the capacitance information converter measures a change in the capacitance value of the first parallel plate capacitor, the information processing module starts the timer to start timing;

[0020] A capacitance change curve is generated based on the detection time and capacitance measurement value corresponding to the capacitance change of each parallel plate capacitor, wherein the abscissa of the capacitance change curve is the timing time, and the ordinate of the capacitance change curve is the capacitance value detected by the capacitance information converter.

[0021] In order to solve the above technical problems, the present invention also provides a method for implementing a capacitive mold flow sensor system embedded in a mold, comprising the following steps:

[0022] Installing the metal plates in the upper mold and the lower mold;

[0023] Powering on all metal plates on the two molds, or all metal plates and one of the molds, to form parallel plate capacitors corresponding to the installation positions of the metal plates, and obtaining an initial capacitance value of each parallel plate capacitor before a material medium is introduced;

[0024] Pour the material medium into the mold cavity, obtain the capacitance detection value of each parallel plate capacitor in real time, and generate a capacitance value change curve of each parallel plate capacitor based on the capacitance detection value and capacitance change time of each parallel plate capacitor;

[0025] The capacitance change direction between the upper mold and the lower mold is determined based on the capacitance change curves of all parallel plate capacitors to determine the flow direction of the material medium in the mold cavity and the position of the material medium in the mold cavity.

[0026] As a preferred solution of the present invention, the method for generating the capacitance change curve of each parallel plate capacitor is as follows:

[0027] Real-time detection of the capacitance value C of the parallel plate capacitor formed by the metal plates distinguished by each mark, and determination of the starting time point t1 when the capacitance value begins to change, and the ending time point t2 corresponding to the stable convergence of the capacitance value;

[0028] Performing data fitting on the capacitance value C detected in real time and the time point t corresponding to each capacitance detection to form a capacitance value variation curve of each parallel plate capacitor;

[0029] The capacitance change direction between the upper mold and the lower mold is determined by combining the capacitance change curves of all parallel plate capacitors.

[0030] As a preferred solution of the present invention, a method for determining the capacitance change direction between the upper mold and the lower mold based on the capacitance value change curves of all parallel plate capacitors is as follows:

[0031] Integrate the capacitance value variation curves of all parallel plate capacitors into the same coordinate axis;

[0032] Determine the time point t1 corresponding to when the capacitance value of each parallel plate capacitor begins to change, and determine the flow direction of the material medium in the mold cavity and the position of the material medium in the mold cavity based on the time points t1 corresponding to when the capacitance values ​​of different parallel plate capacitors begin to change.

[0033] As a preferred solution of the present invention, a specific method for determining the flow direction of the material medium in the mold cavity is:

[0034] Based on the distribution position of each of the metal plates on a single mold, a virtual image of the plate distribution is constructed, and a virtual two-dimensional coordinate axis of the virtual image of the plate distribution is constructed to determine the two-dimensional coordinate value of each of the metal plates;

[0035] Determine the detection time point corresponding to the change in capacitance of the parallel plate capacitor formed by each of the metal plates, and form a two-dimensional array for medium flow direction analysis integrating the detection time point and the two-dimensional coordinate value of each of the metal plates where the capacitance change occurs;

[0036] According to the order of the detection time points from small to large, the distribution positions of the metal plates represented by the two-dimensional coordinate values ​​are connected in sequence to form the flow direction of the material medium in the mold cavity.

[0037] As a preferred solution of the present invention, based on the capacitance change curve of each parallel plate capacitor, the convergence capacitance value of each parallel plate capacitor is determined, and the dielectric constant corresponding to the capacitance of each parallel plate capacitor after final convergence is calculated;

[0038] Determine the standard dielectric constant corresponding to the material dielectric standard of each parallel plate capacitor when it is filled;

[0039] Calculating the difference between the dielectric constant of each parallel plate capacitor and the standard dielectric constant to determine whether there is a parallel plate capacitor that is out of error range;

[0040] The calculation formula for calculating the dielectric constant corresponding to each parallel plate capacitor is:

[0041] ε=Cd / S;

[0042] Wherein, C is the detection capacitance value of the parallel plate capacitor;

[0043] d is the distance between the metal plates corresponding to two positions on the upper mold and the lower mold respectively;

[0044] S is the lateral area of ​​the metal plate.

[0045] Compared with the prior art, the present invention has the following beneficial effects:

[0046] The present invention creatively uses a parallel plate capacitor as a sensor system for measuring the flow direction of a material medium (such as a resin), which has low loss and long service life. When the material medium flows into the area of ​​a parallel plate capacitor, the filling medium in the parallel plate capacitor changes, so the dielectric constant also changes accordingly, causing the capacitance of the entire parallel plate capacitor to change. Therefore, based on the installation position of the metal plate corresponding to the parallel plate capacitor whose capacitance changes, and the start time point of the parallel plate capacitor that sequentially generates the capacitance change, the flow of the material medium can be determined;

[0047] The present invention can not only determine the flow direction of the material medium through the capacitance value change curve of the parallel plate capacitor at all positions, but also determine whether the mold at the position of each parallel plate capacitor is qualified based on the capacitance value change, thereby realizing quality inspection. BRIEF DESCRIPTION OF THE DRAWINGS

[0048] In order to more clearly illustrate the implementation methods of the present invention or the technical solutions in the prior art, the following briefly introduces the drawings required for the implementation methods or the description of the prior art. Obviously, the drawings in the following description are only exemplary, and for ordinary technicians in this field, other implementation drawings can be derived from the provided drawings without creative work.

[0049] Figure 1 Schematic diagram of the structure of a capacitive flow sensor system according to an embodiment of the present invention;

[0050] Figure 2 Schematic diagram of the installation structure of the metal plate according to an embodiment of the present invention;

[0051] Figure 3 is a structural block diagram of an information processing module according to an embodiment of the present invention;

[0052] Figure 4 A schematic diagram of a capacitance change curve according to an embodiment of the present invention;

[0053] The numbers in the figure represent the following:

[0054] 1-metal plate; 2-powered circuit; 3-capacitance information converter; 4-information processing module; 5-information processing module;

[0055] 41-Timer. DETAILED DESCRIPTION

[0056] The following will be combined with the drawings in the embodiments of the present invention to clearly and completely describe the technical solutions in the embodiments of the present invention. Obviously, the described embodiments are only 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.

[0057] like Figures 1 to 3 As shown, the present invention provides a capacitive mold flow sensor system embedded in a mold, comprising: a metal plate 1, a power-on circuit 2, a capacitive information converter 3 and an information processing module 4.

[0058] The metal plate 1 is embedded in the upper mold and the lower mold to form a parallel plate capacitor corresponding to the installation position of the metal plate 1.

[0059] The power circuit 2 is connected to the metal plate 1 , and the power circuit 2 is used to conduct electricity to the metal plate 1 .

[0060] The capacitance information converter 3 is connected to the metal plate 1, and the capacitance information converter 3 is used to measure the capacitance value of the parallel plate capacitor formed by the metal plate 1 after being energized;

[0061] The information processing module 4 is connected to the capacitance information converter 3 .

[0062] The capacitance information converter 3 is used to measure the capacitance value formed by each parallel plate capacitor, and the information processing module 4 is used to generate the capacitance value variation curve of all parallel plate capacitors after the material medium is poured into the mold cavity.

[0063] It should be further supplemented that, in the present embodiment, it is not necessary to arrange the metal electrode plate 1 in all upper molds and lower molds. For example, when one of the molds is made of metal and the opposite surface of the mold is a two-dimensional plane structure, it is only necessary to install the metal electrode plate 1 in the other mold. The metal electrode plate 1 forms a parallel plate capacitor with the surface of the metal mold.

[0064] Otherwise, it is necessary to arrange the metal plates 1 in both the upper mold and the lower mold, and the metal plates 1 installed in the same position in the two molds will form a parallel plate capacitor.

[0065] In this embodiment, a parallel plate capacitor is formed between metal plates 1 and metal plates 1, or between metal plates 1 and a metal mold. This embodiment creatively uses the parallel plate capacitor as a sensor system for measuring the flow direction of a material medium (such as a resin). When the material medium flows into an area of ​​a parallel plate capacitor, the filling medium in the parallel plate capacitor changes, and thus the dielectric constant also changes accordingly, causing the capacitance of the entire parallel plate capacitor to change. Therefore, based on the installation position of the metal plate 1 corresponding to the parallel plate capacitor whose capacitance changes, and the starting time point of the parallel plate capacitor that sequentially generates capacitance changes, the flow of the material medium can be determined, wherein the flow of the material medium is determined in units of surfaces.

[0066] Furthermore, the standard capacitance value of each parallel plate capacitor at the standard mold thickness and the real-time capacitance value of the introduced material medium can be calculated to determine whether the capacitance values ​​of all parallel plate capacitors after the material medium is currently poured in and their corresponding standard capacitance values ​​are within a reasonable error range. If the reasonable error range is exceeded, it means that the volume of the material medium at the mold cavity position corresponding to the parallel plate capacitor is different from the standard volume, thereby achieving quality inspection of the product.

[0067] According to the above, in this embodiment, when the upper mold and the lower mold are made of non-metallic materials, or there is no two-dimensional plane between the opposing surfaces of the upper mold and the lower mold of metal material, it is necessary to set grooves in both the upper mold and the lower mold, and set the metal pole plate 1 in the groove. The metal pole plates 1 on the same mold are in the same plane, that is, all the metal pole plates 1 in the upper mold and the lower mold are respectively in the same plane, and the distance between every two corresponding metal pole plates 1 on the upper mold and the lower mold is the same.

[0068] When the upper mold or the lower mold has a two-dimensional plane, and the mold with the two-dimensional plane is made of metal, in order to reduce the number of metal plates 1 arranged and reduce the secondary grooving work on the mold, the above-mentioned mold can be used as a parallel plate, and the metal plate 1 is opened and arranged in another mold. Since the metal plate 1 is in the same plane, the distance between the metal plate 1 and the side surface of the other mold is the same.

[0069] That is, when the surface of the upper mold or the lower mold made of metal material is flat, only a groove for mounting the metal plate 1 is provided inside the other lower mold or the upper mold.

[0070] The distances between all metal plates 1 and the plane where the upper mold or the lower mold is located are the same, and each metal plate 1 and a metal area of ​​the same area on another mold form a parallel plate capacitor.

[0071] Therefore, a parallel plate capacitor can be formed between each metal electrode plate 1 and the two-dimensional plane of another mold, and the specific number of parallel plate capacitors is determined by the number of metal electrodes 1 .

[0072] The upper mold and the lower mold are provided with grooves for installing the metal plates 1. Multiple rows of metal plates 1 are arranged in sequence on the plane formed by the grooves in the upper mold and the lower mold, and each metal plate 1 is marked and distinguished in sequence.

[0073] When the upper mold and the lower mold are made of metal, an insulating plate 5 is provided between the metal plate 1 and the upper mold, and an insulating plate 5 is also provided between the metal plate 1 and the lower mold.

[0074] Furthermore, the realization principle of measuring capacitance by constructing a parallel plate capacitor through metal plates: According to the principle of LC resonant circuit, the oscillation frequency f can be calculated by the following formula:

[0075]

[0076] Among them, L and C are the original inductance and capacitance values ​​before the mold is poured into the measurement circuit, and ΔC is the change in capacitance during the measurement process. Through the LC resonant circuit, the change in capacitance value can be converted into frequency change based on this principle. The frequency is converted into digital output, and the digital value read is converted back through the program using the formula to get the capacitance value.

[0077] Most of the molds used in production are made of metal. Copper plates cannot be directly embedded in metal molds because the entire mold will be charged after power is turned on. Therefore, insulating materials must be used to separate the plates from the metal mold. The insulating plate 5 is resistant to high temperatures and is rigid, suitable for insulation and fixation. The upper mold or lower mold on one side is non-metallic and does not need to be insulated.

[0078] The present invention adopts a capacitive sensor plate embedded in the mold, which does not need to be replaced every time a mold is replaced, has slow consumption, and will not affect the appearance and performance of the product. The capacitive sensor has low cost and high precision, and the entire system is low in cost and is very suitable for industrial production. In addition, the mold flow monitoring system can arbitrarily change the size, shape, quantity, etc. of the capacitive sensor plate according to the process and product requirements, and has a wide range of uses and high flexibility.

[0079] In this embodiment, the metal plates 1 constituting the parallel plate capacitor are numbered in sequence, so that the information processing module 4 can receive the capacitance change of each parallel plate capacitor, further determine the number of the metal plate 1 corresponding to the parallel plate capacitor, and the position of the metal plate 1 on the mold, and further combine the time when the capacitance change of the metal plate 1 occurs to determine the flow direction of the material medium.

[0080] The information processing module 4 is provided with a timer 41 . When the capacitance information converter 3 measures that the capacitance value of the first parallel plate capacitor changes, the information processing module 4 starts the timer 41 to start timing.

[0081] A capacitance change curve is generated based on the detection time and capacitance measurement value corresponding to the capacitance change of each parallel plate capacitor. The horizontal axis of the capacitance change curve is the timing time, and the vertical axis of the capacitance change curve is the capacitance value detected by the capacitance information converter 3.

[0082] Assuming that the mold cavity inlet formed by the upper mold and the lower mold is at the upper end, after the material medium is poured into the mold cavity inlet, the material medium will move downward under the influence of gravity. In order to specifically detect the moving position of the material medium (such as resin), the implementation method of this embodiment is as follows:

[0083] Before pouring the material medium, the two side plates of each parallel plate capacitor are energized to obtain the initial capacitance value of the parallel plate capacitor formed at each plate position.

[0084] After the material medium is poured in, the capacitance of different parallel plate capacitors begins to change because the material medium moves to the positions of different parallel plate capacitors in sequence. The time points when the capacitance changes of different parallel plate capacitors are detected are determined. Based on the order in which the capacitance changes begin to be detected, the flow direction of the material medium can be determined.

[0085] After the injection molding is completed, the capacitance of each parallel plate capacitor gradually begins to converge stably. The converged capacitance value is compared with the standard capacitance value of the parallel plate capacitor at that position. When the converged capacitance value is greater than the standard capacitance value, it means that the material dielectric filling amount at that position is not within the standard range. Similarly, when the converged capacitance value is less than the standard capacitance value, it means that the material dielectric filling amount at that position is not within the standard range, and the thickness of the product produced this time is uneven, which can further realize the quality inspection of the mold production products.

[0086] Only when the converged capacitance value and the standard capacitance value are within a reasonable error range, it means that the material medium filling amount at that position is within the standard range. Therefore, the mold flow sensor system in this embodiment is not only used to detect the flow direction of the material medium in the mold cavity, but also combines the principle of capacitance detection and the parameters that affect the capacitance value to perform quality inspection on the products produced by the mold.

[0087] The implementation method of the above-mentioned capacitive mold flow sensor system embedded in the mold comprises the following steps:

[0088] Installing the metal plates in the upper mold and the lower mold;

[0089] Power is supplied to all metal plates on the two molds, or to all metal plates and one of the molds, to form parallel plate capacitors corresponding to the installation positions of the metal plates, and to obtain the initial capacitance value of each parallel plate capacitor before the material medium is introduced;

[0090] Pour the material medium into the mold cavity, obtain the capacitance detection value of each parallel plate capacitor in real time, and generate a capacitance value change curve of each parallel plate capacitor based on the capacitance detection value and capacitance change time of each parallel plate capacitor;

[0091] The capacitance change direction between the upper mold and the lower mold is determined based on the capacitance change curves of all parallel plate capacitors to determine the flow direction of the material medium in the mold cavity and the position of the material medium in the mold cavity.

[0092] In this embodiment, generally, metal plates are set in the upper mold and the lower mold, the metal plates in each mold are on the same plane, the spacing and distribution area of ​​the metal plates in the two molds are the same, and the only parameter that affects the capacitance value between the two metal plates at the same position is the dielectric constant, that is, the flow direction of the filling material medium (such as resin).

[0093] When one of the molds is a metal medium and the opposite surface of the mold and the other mold is a two-dimensional plane, the side mold can be used as one of the side plates of a parallel plate capacitor, and the metal plate can be grooved and installed in the other mold, so that a parallel plate capacitor is formed between each metal plate and its opposite mold surface.

[0094] In order to further explain how to detect the flow direction of the material medium, it is assumed that four metal plates are respectively provided on the two molds, wherein every two metal plates are arranged opposite to each other, so that the two metal plates on the two molds can form a parallel plate capacitor.

[0095] The method for generating the capacitance variation curve of each parallel plate capacitor is as follows:

[0096] Real-time detection of the capacitance value C of the parallel plate capacitor formed by each marked metal plate, and determination of the starting time point t1 when the capacitance value begins to change, and the ending time point t2 corresponding to the stable convergence of the capacitance value;

[0097] The capacitance value C detected in real time is fitted with the time point t corresponding to each capacitance detection to form a capacitance value change curve of each parallel plate capacitor;

[0098] The capacitance change direction between the upper mold and the lower mold is determined by combining the starting time point t1 of the capacitance value change curves of all parallel plate capacitors.

[0099] Specifically, assuming that the material medium is poured into the mold cavity from the top, the material medium will flow from top to bottom, so the capacitance between the two parallel plate capacitors in the upper row will change almost simultaneously at time t1, while the capacitance between the two parallel plate capacitors in the lower row will change simultaneously later at time t2. After integrating the four capacitance value change curves into the same coordinate axis, the specific formation is as follows: Figure 4 The graph shown.

[0100] Since the capacitance change start time t2 of the two parallel plate capacitors in the lower row is greater than the capacitance change start time t1 of the two parallel plate capacitors in the upper row, it can be determined that the flow direction of the material medium flows from top to bottom.

[0101] That is, the method for determining the capacitance change direction between the upper mold and the lower mold based on the capacitance value change curves of all parallel plate capacitors is:

[0102] Integrate the capacitance variation curves of all parallel plate capacitors into the same coordinate axis;

[0103] Determine the time point t1 corresponding to when the capacitance value of each parallel plate capacitor begins to change, and determine the flow direction of the material medium in the mold cavity and the position of the material medium in the mold cavity based on the time point t1 corresponding to when the capacitance values ​​of different parallel plate capacitors begin to change.

[0104] In order to further determine the flow direction of the material medium in the mold cavity, it is necessary to combine the distribution position of each metal plate to determine it. The specific implementation method is:

[0105] Based on the distribution position of each metal plate on a single mold, a plate distribution virtual image is constructed, and a virtual two-dimensional coordinate axis of the plate distribution virtual image is constructed to determine the two-dimensional coordinate value of each metal plate;

[0106] Determine the detection time point corresponding to the change in capacitance of the parallel plate capacitor formed by each metal plate, and form a two-dimensional array for medium flow direction analysis integrating the detection time point and the two-dimensional coordinate value of each metal plate where the capacitance change occurs;

[0107] According to the order of the detection time points from small to large, the distribution positions of the metal plates represented by the two-dimensional coordinate values ​​are connected in sequence to form the flow direction of the material medium in the mold cavity.

[0108] Based on the capacitance change curve of each parallel plate capacitor, determine the converged capacitance value of each parallel plate capacitor, and calculate the dielectric constant corresponding to the capacitance of each parallel plate capacitor after the capacitance finally converges;

[0109] Determine the standard dielectric constant corresponding to the material dielectric standard filling of each parallel plate capacitor;

[0110] Calculating the difference between the dielectric constant of each parallel plate capacitor and the standard dielectric constant to determine whether there is a parallel plate capacitor that is out of error range;

[0111] Among them, the calculation formula for calculating the dielectric constant corresponding to each parallel plate capacitor is:

[0112] ε=Cd / S;

[0113] Wherein, C is the detection capacitance value of the parallel plate capacitor;

[0114] d is the distance between the metal plates corresponding to two positions on the upper mold and the lower mold respectively;

[0115] S is the lateral area of ​​the metal plate.

[0116] Assume that the standard dielectric constant corresponding to the material dielectric standard at the location of each parallel plate capacitor is ε1, and after pouring the material dielectric, when the capacitance of each parallel plate capacitor finally converges, the dielectric constant of the parallel plate capacitor at this location is ε2, calculate the dielectric constant ε2 corresponding to the capacitance of each parallel plate capacitor when it finally converges, and the difference between the standard dielectric constant ε1 corresponding to the material dielectric standard of the parallel plate capacitor when it is filled. When the difference is within a reasonable range, it means that the thickness of the material dielectric at this location is within a reasonable thickness error range. When the difference exceeds the reasonable range, it means that the thickness of the material dielectric at this location exceeds the reasonable thickness error range.

[0117] Therefore, this embodiment can not only determine the flow direction of the material medium through the capacitance value change curve of the parallel plate capacitors at all positions, but also determine whether the mold at the position of each parallel plate capacitor is qualified based on the capacitance value change, thereby realizing quality inspection.

[0118] The above embodiments are only exemplary embodiments of the present application and are not intended to limit the present application. The protection scope of the present application is defined by the claims. Those skilled in the art may make various modifications or equivalent substitutions to the present application within the essence and protection scope of the present application, and such modifications or equivalent substitutions shall also be deemed to fall within the protection scope of the present application.

Claims

1. A capacitive mold flow sensor system embedded in a mold, characterized in that: include: The metal plate (1) is embedded in the upper mold and the lower mold to form a parallel plate capacitor corresponding to the installation position of the metal plate (1); An electric circuit (2) connected to the metal plate (1), the electric circuit (2) being used to conduct electricity to the metal plate (1); A capacitance information converter (3) connected to the metal plate (1), the capacitance information converter (3) being used to measure the capacitance value of a parallel plate capacitor formed by the metal plate (1) after being energized; An information processing module (4) connected to the capacitance information converter (3); The capacitance information converter (3) is used to measure the capacitance value formed by each parallel plate capacitor, and the information processing module (4) is used to record the capacitance value changes of all parallel plate capacitors and generate a curve.

2. A capacitive mold flow sensor system embedded in a mold according to claim 1, characterized in that: All the metal plates (1) in the upper mold and the lower mold are respectively located in the same plane, and the distance between every two corresponding metal plates (1) on the upper mold and the lower mold is the same; When the upper mold and the lower mold are closed, each installation position of the metal plate (1) forms a parallel plate capacitor.

3. The capacitive mold flow sensor system embedded in a mold according to claim 1, characterized in that: The upper mold and the lower mold are provided with grooves for mounting the metal plate (1), and when the upper mold and the lower mold are made of metal, an insulating plate (5) is provided between the metal plate (1) and the upper mold, and an insulating plate (5) is also provided between the metal plate (1) and the lower mold; A plurality of rows of the metal plates (1) are arranged in sequence on the plane formed by the grooves in the upper mold and the lower mold, and each of the metal plates (1) is marked and distinguished in sequence.

4. The capacitive mold flow sensor system embedded in a mold according to claim 3, characterized in that: The lower mold and the upper mold are provided with grooves for mounting the metal plate (1); The spacing between all the metal plates (1) in the upper mold and the lower mold is the same, and the side surface areas of all the metal plates (1) are the same. The metal plates (1) corresponding to each other at every two positions in the upper mold and the lower mold form a parallel plate capacitor.

5. The capacitive mold flow sensor system embedded in a mold according to claim 1, characterized in that: The information processing module (4) is provided with a timer (41), and when the capacitance information converter (3) measures that the capacitance value of the first parallel plate capacitor changes, the information processing module (4) starts the timer (41) to start timing; A capacitance change curve is generated based on the detection time and capacitance measurement value corresponding to the capacitance change of each parallel plate capacitor, wherein the abscissa of the capacitance change curve is the timing time, and the ordinate of the capacitance change curve is the capacitance value detected by the capacitance information converter (3).

6. A method for implementing a capacitive mold flow sensor system embedded in a mold according to any one of claims 1 to 5, characterized in that: The following steps are involved: Installing the metal plates in the upper mold and the lower mold; Powering on all metal plates on the two molds, or all metal plates and one of the molds, to form parallel plate capacitors corresponding to the installation positions of the metal plates, and obtaining an initial capacitance value of each parallel plate capacitor before a material medium is introduced; Pour the material medium into the mold cavity, obtain the capacitance detection value of each parallel plate capacitor in real time, and generate a capacitance value change curve of each parallel plate capacitor based on the capacitance detection value and capacitance change time of each parallel plate capacitor; The capacitance change direction between the upper mold and the lower mold is determined based on the capacitance change curves of all parallel plate capacitors to determine the flow direction of the material medium in the mold cavity and the position of the material medium in the mold cavity.

7. The method for implementing a capacitive mold flow sensor system embedded in a mold according to claim 6, characterized in that: The method for generating the capacitance change curve of each parallel plate capacitor is as follows: Real-time detection of the capacitance value C of the parallel plate capacitor formed by the metal plates distinguished by each mark, and determination of the starting time point t1 when the capacitance value begins to change, and the ending time point t2 corresponding to the stable convergence of the capacitance value; Performing data fitting on the capacitance value C detected in real time and the time point t corresponding to each capacitance detection to form a capacitance value variation curve of each parallel plate capacitor; The capacitance change direction between the upper mold and the lower mold is determined by combining the capacitance change curves of all parallel plate capacitors.

8. The method for implementing a capacitive mold flow sensor system embedded in a mold according to claim 7, characterized in that: The method for determining the capacitance change direction between the upper mold and the lower mold based on the capacitance value change curves of all parallel plate capacitors is as follows: Integrate the capacitance value variation curves of all parallel plate capacitors into the same coordinate axis; Determine the time point t1 corresponding to when the capacitance value of each parallel plate capacitor begins to change, and determine the flow direction of the material medium in the mold cavity and the position of the material medium in the mold cavity based on the time points t1 corresponding to when the capacitance values ​​of different parallel plate capacitors begin to change.

9. The method for implementing a capacitive mold flow sensor system embedded in a mold according to claim 8, characterized in that: The specific implementation method for determining the flow direction of the material medium in the mold cavity is: Based on the distribution position of each of the metal plates on a single mold, a virtual image of the plate distribution is constructed, and a virtual two-dimensional coordinate axis of the virtual image of the plate distribution is constructed to determine the two-dimensional coordinate value of each of the metal plates; Determine the detection time point corresponding to the change in capacitance of the parallel plate capacitor formed by each of the metal plates, and form a two-dimensional array for medium flow direction analysis integrating the detection time point and the two-dimensional coordinate value of each of the metal plates where the capacitance change occurs; According to the order of the detection time points from small to large, the distribution positions of the metal plates represented by the two-dimensional coordinate values ​​are connected in sequence to form the flow direction of the material medium in the mold cavity.

10. The method for implementing a capacitive mold flow sensor system embedded in a mold according to claim 7, characterized in that: Based on the capacitance change curve of each of the parallel plate capacitors, determine the converged capacitance value of each of the parallel plate capacitors, and calculate the dielectric constant corresponding to the capacitance of each of the parallel plate capacitors after it finally converges; Determine the standard dielectric constant corresponding to the material dielectric standard of each parallel plate capacitor when it is filled; Calculating the difference between the dielectric constant of each parallel plate capacitor and the standard dielectric constant to determine whether there is a parallel plate capacitor that is out of error range; The calculation formula for calculating the dielectric constant corresponding to each parallel plate capacitor is: ε=Cd / S; Wherein, C is the detection capacitance value of the parallel plate capacitor; d is the distance between the metal plates corresponding to two positions on the upper mold and the lower mold respectively; S is the lateral area of ​​the metal plate.

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