JP3868751B2 - Adhesive applicator - Google Patents

Description

[0001]
BACKGROUND OF THE INVENTION
The present invention relates to an adhesive coating apparatus that sprays an adhesive that cures by mixing two liquids.
[0002]
[Prior art]
FIG. 9 is a schematic diagram showing a conventional apparatus for detecting coating unevenness of a coating material disclosed in, for example, Japanese Patent Application Laid-Open No. 61-225608. In FIG. 9, 1 is a drying furnace, 2 is a magnetic tape coated with magnetic powder and dried in the drying furnace 1, 3 is a roller, 4 is a drum that winds the magnetic tape 2 through the roller 3, and 5 is magnetic. A rod-shaped light source 6 disposed below the middle of the traveling path of the tape 2 so as to be orthogonal to the traveling direction of the magnetic tape 2, 6 is a diffusion plate that diffuses light from the light source 5. The back surface of the magnetic tape 2 is irradiated with light from the light source 5.
[0003]
Reference numeral 7 denotes a camera disposed above the magnetic tape 2 so as to face the light source 5. The camera 7 incorporates a one-dimensional image sensor and images an image obtained by the transmitted light of the magnetic tape 2. The image is picked up by the sensor, and the output signal is supplied to the control device 8. The control device 8 includes an A / D converter that converts the output signal of the camera 7 into a digital signal bit by bit, a memory that sequentially stores the A / D converted digital signal, and each bit stored in the memory. An arithmetic means for calculating a signal level difference at an arbitrary bit interval from the digital signal is incorporated.
[0004]
Next, the operation will be described. Light having a luminance distribution is irradiated from the light source 5, but the luminance is averaged to some extent by the diffusion plate 6 and irradiated to the magnetic tape 2. In the magnetic tape 2, light does not pass through a portion with a magnetic material, and light passes through a portion without a magnetic material. A portion with a high degree of aggregation of magnetic materials in the planar direction of the magnetic tape 2 has a small amount of transmitted light, and a portion with a low degree of aggregation has a large amount of transmitted light. The surface of the magnetic tape 2 can be imaged with the camera 7 and the difference in the amount of transmitted light can be obtained as a grayscale image. The image sensor of the camera 7 is one-dimensional, and sensor elements are arranged in a direction perpendicular to the traveling direction of the magnetic tape 2 to capture images in synchronization with the traveling speed of the magnetic tape 2, and the difference in signal level is calculated at an arbitrary bit interval. By doing so, the density of the magnetic material on the magnetic tape 2, that is, unevenness can be detected.
[0005]
Since there is a large difference in the intensity (signal level) of the light imaged by the camera 7 with and without the magnetic material, it is possible to treat the luminance unevenness or the influence of the change of the light emitted from the diffusion plate 6 as an error. Further, since the direction of the irradiated light is not specified, the ratio of the transmitted light amount of the magnetic tape 2 to the irradiated light amount cannot be accurately grasped, the contribution of irradiated light and disturbance light to the transmitted light amount cannot be distinguished, The influence due to the variation in the light transmittance of the fabric of the tape 2 can also be treated as an error.
[0006]
FIG. 10 is a schematic view showing an apparatus for detecting the coating thickness of a conventional adhesive disclosed in, for example, Japanese Patent Application Laid-Open No. 07-181018. In FIG. 10, 9 is an object to be applied, 10 is an adhesive, 11 is a light source that irradiates the application surface of the application object 9 to which the adhesive 10 is applied, near infrared rays, and 12 is in the optical path of reflected light on the application surface. It is a filter that transmits only near-infrared rays in an absorption wavelength band of a specific component contained in the adhesive 10.
[0007]
Reference numeral 13 denotes a lens that forms a two-dimensional image of the adhesive-coated surface on the image sensor 14 with light that has passed through the filter 12, 15 denotes a TV camera in which the image sensor 14 is incorporated, and 16 denotes an image supplied from the TV camera 15. It is an A / D converter that converts a signal into a digital signal. Reference numeral 17 denotes a computer that stores and calculates an image signal converted into a digital signal for each pixel, and adheres the image data to be measured based on the relationship of the coating thickness of the adhesive 10 to the reference image data obtained in advance. The application thickness of the agent 10 is calculated. Reference numeral 18 denotes a display that displays the calculated application thickness of the adhesive 10 for each pixel.
[0008]
Next, the operation will be described. Near infrared rays emitted from the light source 11 are reflected by the adhesive application surface of the application object 9 and reach the filter 12. The filter 12 transmits only near-infrared light in the absorption wavelength band of the specific component contained in the adhesive 10, but the near-infrared light transmitted through the filter 12 has a different degree of absorption depending on the coating thickness of the adhesive 10, The strength changes according to the thickness of the adhesive 10 applied.
[0009]
This intensity change is captured as image data in the computer 17 via the TV camera 15 and the A / D converter 16. A sample in which the coating thickness of the adhesive 10 is changed is manufactured in advance to obtain reference image data, and the coating thickness is obtained by dividing the weight of the adhesive 10 by the coating area assuming that the density of the adhesive 10 is constant. And the reference image data and the coating thickness of the adhesive 10 are associated with each other. Thereafter, the application thickness of the adhesive 10 is calculated by the computer 17 from the difference between the image data to be measured and the reference image data, and the calculation result is displayed by the display 18. The illustrated configuration is an effective means when the component that absorbs near infrared rays is uniformly dispersed in the adhesive 10, the irradiation intensity of the near infrared rays on the coated surface is uniform and constant, and the adhesive 10 does not flow. .
[0010]
[Problems to be solved by the invention]
By the way, in order to obtain a sufficient adhesive strength in the adhesion of an adherend using an adhesive that starts and cures by mixing two liquids (referred to as a two-liquid room-temperature curable adhesive), 2 It is necessary to control the weight ratio of the liquid and mix well. The method of spraying the two liquids simultaneously from different nozzles and applying them by mixing is the best method for obtaining sufficient mixing in terms of mixing. On the other hand, the weight of each of the two liquids to be sprayed cannot be measured. Conventionally, the management of the weight ratio of two liquid mixing (referred to as mixing failure) relies on the accuracy of the adhesive spray application mechanism, which is uncertain. It was a thing.
[0011]
In order to compensate for the uncertainty of mixing failure, it is necessary to set an excessive adhesive strength far exceeding the required adhesive strength. Since the bonding strength is proportional to the bonding area, the bonding area is set excessively. In addition, increasing the adhesion area also has an advantage that even if the mixing failure is deviated from a predetermined value in a partial portion and the adhesion strength is reduced, there is no problem as a whole.
[0012]
On the other hand, there is a method in which two liquids are put in separate syringes regardless of spray application and the application weight is measured each time the adhesive is applied one by one, followed by mixing with a stirring member. Therefore, it takes a long time and productivity is poor. In addition, since only an insufficient degree of mixing can be obtained, it is eventually necessary to increase the bonding area.
[0013]
Therefore, for example, the adhesion area larger than the magnet attachment area, such as the adhesion of the rotor of the motor to the magnet, cannot be obtained and the adhesion strength exceeding the required adhesion strength cannot be obtained. A curable adhesive cannot be used, and a one-component adhesive that is cured by heating (referred to as a one-component heat-curable adhesive) has been used.
[0014]
In the one-component heat curing type adhesive, in order to complete the curing polymerization reaction, it is necessary to raise the temperature of the adhesive to a predetermined temperature. For this purpose, it is necessary to raise the temperature of the adherend between which the adhesive is sandwiched. For example, a rotor of a large motor requires a lot of time to heat, resulting in poor productivity. In addition, a large heating furnace is required and the equipment cost is great. Compared with this, the two-component room-temperature curable adhesive does not require heating of the adherend and can shorten the adhesive curing time, so it is highly productive and does not require a heating furnace. Can be reduced.
[0015]
In order to introduce a two-component room temperature curable adhesive for the purpose of reducing the bonding cost, it is required to measure and manage the amount of adhesive applied during spraying between the spray gun and the application target.
[0016]
The adhesive being sprayed is, for example, in a state having fine particles of the adhesive having a speed in a conical region. Considering that this is irradiated with light and receiving light on the opposite side with a spray adhesive in between, the part without adhesive fine particles is transmitted as it is, and the part with fine particles is transmitted with reduced light intensity. Or light that is reflected and transmitted or blocked by the surface of the fine particles depending on the incident angle.
[0017]
When the spray application amount of the adhesive changes, for example, in a conical spray shape, the diameter of a circle that is a cut perpendicular to the axis changes, and the ratio of the adhesive fine particles in the circle changes. The change in the ratio of the adhesive fine particles in the circle is caused by the change in the size and number of the fine particles. The diameter and shape of the circle and the size and number of fine particles in the circle change sequentially during spraying.
[0018]
Changes in the diameter and shape of the circle and the size and number of particles in the circle are captured by the change in the amount of received light. First, the direction of the light applied to the spray adhesive is unidirectional and uniform. It is required to have strength. When light is irradiated from various directions, the light is reflected or interferes in various directions due to changes in the diameter of the circle and the size of the fine particles, and light outside the predetermined range is received. The received light cannot be associated. Even if the irradiation light is uneven or changes in intensity, the same unevenness or intensity change cannot be received as it is, and the irradiation light and the received light cannot be correlated. I can't.
[0019]
The first conventional example shown in Japanese Patent Laid-Open No. 61-225608 having the configuration shown in FIG. 9 is based on the premise that the magnetic body does not transmit light, and the received light intensity (signal level) with and without the magnetic body. By using the fact that there is a large difference in the amount of light, it is configured so that no special measures are taken with respect to the direction of illumination light, brightness unevenness, and the influence of disturbance light, which makes the amount of received light unstable. The quantity cannot be measured stably.
[0020]
Further, the second conventional example shown in Japanese Patent Application Laid-Open No. 07-181018 having the configuration shown in FIG. 10 is based on the premise that the component that absorbs near infrared rays is uniformly dispersed in the adhesive. It cannot be expected that the component that absorbs near infrared rays is uniformly dispersed in the fine particles of the spray adhesive. Moreover, since it becomes the structure which does not take a special countermeasure about the influence of a near infrared ray direction and an intensity | strength nonuniformity similarly to a 1st prior art example, the application quantity of a spraying adhesive agent cannot be measured stably.
[0021]
The present invention has been made to solve the above-described problems, and is an adhesive application device that can stably measure the amount of adhesive applied in the spray application of a two-component room temperature curable adhesive. The purpose is to obtain.
[0022]
[Means for Solving the Problems]
The adhesive coating apparatus according to the present invention is a spray gun that sprays two liquids of an adhesive that starts and cures by mixing two liquids simultaneously from different nozzles toward an application area of an object to be coated. A projector and a light receiver arranged so that the irradiated parallel laser light is received across the cone axis of the adhesive sprayed from the spray gun, the sensor signal value, and the adhesive application amount; Is stored immediately before the spraying of the adhesive into the space between the projector and the receiver within a range that can be approximated by the above conversion formula. The amount of adhesive applied is determined from the sensor signal value obtained by integrating the signal corresponding to the ratio of the laser light amount of the light receiver during spraying of the adhesive to the laser light amount of the light receiver based on the above conversion formula. Measure quantity Together, it is characterized in that the coating amount of the adhesive spray has an arithmetic unit for performing acceptability determination of whether they meet the above specifications.
[0023]
Further, the calculation means calculates the sensor signal value and the adhesive application amount during the spraying time collected by changing the setting value of the parameter for changing the spray state and the application amount of the adhesive, and the sensor signal value on the horizontal axis. Based on the third-order regression equation H and the first-order regression equation I, which are plotted in a two-dimensional coordinate system with the coating amount taken along the vertical axis, A linear regression equation J indicating the correlation with the differential coefficient of the third-order regression equation H in the sensor signal value for obtaining the coating amount of the control standard median value, and the correlation between the differential coefficient and the regression coefficient of the first-order regression equation I A linear regression equation K representing the above and the linear equation obtained by substituting the regression equation J into the regression equation K is used as the calibration equation L of the above conversion equation, and the sensor signal value and the adhesive collected at the time of calibration Substituting the applied amount into the calibration formula L, the conversion formula between the sensor signal value and the applied amount of adhesive is derived. The one in which the features.
[0024]
DETAILED DESCRIPTION OF THE INVENTION
Embodiment 1 FIG.
FIG. 1 is a diagram for explaining an adhesive coating apparatus according to Embodiment 1 of the present invention, and is a diagram for explaining a parallel laser light irradiation method. In FIG. 1, 19 is a spray gun for spraying and applying an adhesive to an application object, 20 is an adhesive sprayed in a conical shape from the spray gun 19 to the application object 21, and 22 is spraying perpendicular to the cone axis. A parallel laser beam crossing the adhesive is irradiated from the projector 23 to the light receiver 24.
[0025]
FIG. 2 is a view of FIG. 1 as viewed from above, and shows a state in which parallel laser light 22 is not completely blocked by the spray adhesive 20 but is transmitted with a light amount reduced at a portion indicated by a broken line 25.
[0026]
Moreover, FIG. 3 is a figure explaining the means to measure the application quantity of a 2 liquid room temperature curing adhesive. In FIG. 3, two spray guns 19 are used to apply the two-component room temperature curable adhesive. The two spray guns 19 are distributed and tilted with respect to the vertical direction, and are arranged so that the two liquids coincide on the application surface of the application object 21. The two sets of laser projectors and receivers 23 and 24 are arranged so that the parallel laser beam 22 crosses perpendicularly to the cone axis of the spray adhesive. Reference numeral 27 denotes an A / D converter that converts an analog signal supplied from the light receiver 24 through the signal cable 26a into a digital signal. Reference numeral 28 denotes a digital signal supplied from the A / D converter 27 through the signal cable 26b for bonding. It is a computer as a calculation means which converts into the application quantity of an agent and outputs the pass / fail judgment of the application quantity.
[0027]
In the above configuration, since the laser is excellent in straightness at a single wavelength, the spray adhesive can be irradiated with light in one direction without unevenness. Moreover, since the energy density is high, it is easy to distinguish from ambient light. By irradiating the spray adhesive 20 with this laser as parallel light, the diameter and shape of the circle of the spray adhesive at the cut perpendicular to the conical axis and the variation in the size and number of the adhesive fine particles in the circle are received by the light receiver 24. It can be seen as a change in the amount of received light. The amount of received light during the spraying of the adhesive is indicated by a waveform as shown in FIG. 4, for example. The horizontal axis represents time T, and the vertical axis represents the digital signal value E supplied from the light receiver 24 of the sensor via the A / D converter 27.
[0028]
FIG. 5 is a diagram for explaining the relationship between the amount of adhesive applied and the integral value of the signal waveform shown in FIG. In FIG. 5, the horizontal axis represents the sensor signal value X obtained by integrating the waveform of FIG. 4, and the vertical axis represents the adhesive application amount Y. M0 represents the standard median value of the amount of adhesive applied, and E0 represents the sensor signal value corresponding thereto. When the adhesive application amount is changed and the sensor signal value at that time is taken, the linear regression equation Y = aX + b (a) is obtained for the sensor signal value X and the adhesive application amount Y in the adhesive in the same production lot. : A regression coefficient, b: a constant), a range R in which a correlation that can be approximated is obtained and a range that is not so are obtained. By applying the linear regression equation obtained in the range R as a conversion formula for calculating the coating amount Y from the sensor signal value X together with the standard value of the coating amount, the computer 28 stores the coating amount during the spraying of the adhesive. Measurement can be performed to determine whether or not the standard value is satisfied, and the result can be output.
[0029]
Embodiment 2. FIG.
The viscosity of the adhesive varies depending on the production lot and the storage period from the date of manufacture to the date of use. The viscosity is adjusted by the adhesive manufacturer, but it varies by 10 to 20% depending on the production lot. This is subject to changes due to the length of the storage period. Moreover, the viscosity of many adhesives does not become a constant value with respect to the flow rate. Adhesive manufacturers measure viscosity at a specified low speed and adjust the viscosity. However, if the production lot and storage period are different, the viscosity at the high speed is different even if the specified low speed viscosity is the same. It is impossible for an adhesive maker to adjust the viscosity at an arbitrary flow rate, and since it is generally controlled at a low speed such as the discharge speed of an adhesive in a widely used coating machine, the viscosity at high speed in spray coating is Equal to unmanaged.
[0030]
When the viscosity of the adhesive changes, the diameter and shape of the cut perpendicular to the cone axis of the sprayed adhesive by parallel laser light, and the size and number of the adhesive fine particles in the circle change greatly, and the regression coefficient of the conversion formula in FIG. a and constant b change. Therefore, it is necessary to derive and use a conversion formula (regression coefficient a or constant b) for each sealed container of the adhesive in consideration of the variation in the storage period. In order to derive the conversion formula, it is necessary to change the application amount Y of the adhesive and plot the corresponding sensor signal value X as shown in FIG.
[0031]
However, since the production of the product is stopped during this work, it is desired to minimize the work time. The viscosity does not always change so as to cause a problem in the accuracy of coating amount measurement for each sealed container of adhesive. If it is not confirmed whether the coating amount is in the vicinity of the standard median MO for each sealed container, the coating amount Y is adjusted (referred to as coating amount check operation), so that the conversion formula can be set only by this operation. Is desirable.
[0032]
FIG. 6 is a diagram for explaining a method for deriving a conversion formula in a coating amount check operation in the calibration of the conversion formula (first-order regression formula I) by the calculator 28 according to Embodiment 2 of the present invention. . In FIG. 6, the horizontal axis represents the sensor signal value X, and the vertical axis represents the amount of spray adhesive applied Y. FIG. 6 uses an adhesive of one sealed container (same viscosity) in this two-dimensional coordinate system. 3 is obtained by plotting the sensor signal value X during the spraying time collected by changing the set value of the parameter (spray pressure of the spray gun 19) for changing the coating amount and the coating amount Y of the adhesive, and obtaining by the least square approximation method. The following regression equation H (H = AX ³ + q, A is a regression coefficient, q is a constant), primary regression equation I (I = aX + b), 3 in the sensor signal value E0 to obtain the application amount M0 of the control standard median value shows the differential coefficient 3AE0 ² of the following regression equation H.
[0033]
The linear regression formula I is a conversion formula for converting the applied amount Y of the adhesive from the sensor signal value X to be obtained for each sealed container of the adhesive. The regression equation I is determined by obtaining a regression coefficient a and a constant b. As a result of examining the regression equation and the differential coefficient obtained in FIG. 6 by changing the viscosity of the adhesive for a large number of sealed container adhesives, the correlation shown in FIG. 7 and FIG.
[0034]
Figure 7 is a management standard median coating amount M0 and relationships derivative 3AE0 ² first-order regression equation ^{J (: 3AE0 2 = cM0 +} d, c is the regression coefficient, d is a constant) indicates a can be approximated by. Further, FIG. 8 is the derivative 3AE0 ² relationship is 1 the regression coefficients a regression formula I linear regression equation ^{K (a = e (3AE0 2} ) + f, e are regression coefficients, f is a constant) that can be approximated by Show. When the regression equation J is substituted into the regression equation K, the linear equation L: a = e (cM0 + d) + f is obtained. From this, b = M0−aE0 is obtained. That is, in the application check operation, when the adhesive application amount M0 and the sensor signal value E0 are obtained, the regression coefficient a and the constant b of the conversion formula are obtained from this.
[0035]
When measuring the amount of spray adhesive applied during product production, add / subtract the total coating amount conversion error due to the error in deriving the above regression equations and differential coefficients to the coating amount calculated based on the conversion formula I. It is determined whether the obtained value satisfies the standard upper and lower limits of the coating amount.
[0036]
As described above, the conversion formula can be derived only by the application check work, and the time for calibrating the conversion formula can be reduced (included in the application check work time).
[0037]
【The invention's effect】
As described above, according to the present invention, the amount of light received and the amount of adhesive applied are related by a linear regression equation using parallel laser light. The application amount of the liquid can be measured, and there is an effect of reducing the bonding cost by applying a two-liquid room temperature curing adhesive.
[0038]
In addition, the conversion formula between the received light amount and the adhesive application amount can be calibrated with the received light amount and the adhesive application amount obtained in the application amount check operation performed for each sealed container of the adhesive, so the conversion formula calibration time There is an effect to reduce.
[Brief description of the drawings]
FIG. 1 is a diagram for explaining an adhesive coating apparatus according to Embodiment 1 of the present invention and for explaining a parallel laser beam irradiation method;
FIG. 2 is a view of FIG. 1 as viewed from above, and shows a state in which parallel laser light 22 is not completely blocked by the spray adhesive 20 but is transmitted with a light amount reduced at a portion indicated by a broken line 25;
FIG. 3 is a diagram for explaining means for measuring the coating amount of a two-component room temperature curing adhesive according to Embodiment 1 of the present invention.
FIG. 4 is a diagram for explaining a signal waveform supplied from a light receiver according to the first embodiment of the present invention.
FIG. 5 is a diagram for explaining the relationship between the amount of adhesive applied and the sensor signal value according to the first embodiment of the present invention.
FIG. 6 is a diagram for explaining a method for deriving a conversion formula in a coating amount check operation according to the second embodiment of the present invention.
7 is a diagram for explaining the present invention according to the second embodiment of the invention, the coating amount M0 and derivative 3AE0 ² relationship management standard median.
[8] relates to the second embodiment of the present invention, is a diagram illustrating the relationship between the regression coefficient a derivative 3AE0 ² regression formula I.
FIG. 9 is a diagram for explaining a conventional apparatus for detecting coating unevenness of a coating material.
FIG. 10 is a diagram for explaining a conventional apparatus for detecting the coating thickness of an adhesive.
[Explanation of symbols]
19 spray gun, 20 adhesive, 21 application object, 22 parallel laser beam, 23 projector, 24 light receiver, 25 attenuated laser beam, 26a, 26b signal cable, 27 A / D converter, 28 computer (calculation means) ).

Claims (1)

A spray gun that sprays two liquids of an adhesive that starts and cures by mixing the two liquids simultaneously from different nozzles toward the application area of the object to be coated;
A projector and a receiver arranged so that the irradiated parallel laser light is received across the cone axis of the adhesive sprayed from the spray gun;
A conversion formula in which the correlation between the sensor signal value and the adhesive application amount is given as a linear regression equation and a standard value of the application amount are stored. Bonding based on the above conversion formula from the sensor signal value obtained by integrating the signal corresponding to the ratio of the laser light quantity of the light receiver during spraying of the adhesive to the laser light quantity of the light receiver immediately before the adhesive is sprayed into the space And calculating the application amount so as to determine the application amount of the agent, and calculating means for determining whether or not the application amount during the spraying of the adhesive satisfies the standard value ,
The calculation means applies the sensor signal value and the adhesive application amount during the spraying time collected by changing the setting value of the parameter that changes the spray state and the application amount of the adhesive, with the sensor signal value as the horizontal axis. Based on the 3rd order regression equation H and the 1st order regression equation I obtained by plotting the amount in a two-dimensional coordinate system with the vertical axis, and using the least square approximation method, the application amount of the management standard and the management standard A linear regression equation J indicating the correlation with the differential coefficient of the cubic regression equation H in the sensor signal value for obtaining the median coating amount, and a correlation between the differential coefficient and the regression coefficient of the linear regression equation I are illustrated. The linear regression equation K is obtained, and the linear equation obtained by substituting the regression equation J into the regression equation K is used as the calibration equation L of the above conversion equation, and the sensor signal values collected during calibration and the application of the adhesive JP that by substituting the amount the calibration equation L derives a conversion formula of the coating weight of the sensor signal value and the adhesive Adhesive applying device to.

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