JP3598214B2 - Sealant application inspection device - Google Patents

Description

[0001]
TECHNICAL FIELD OF THE INVENTION
The present invention relates to a sealant application inspection device.
[0002]
[Prior art]
A screw screwed to a machine part may loosen its fastening due to vibration, and may cause water leakage or oil leakage. Therefore, when a bolt to which vibration is applied for a long time, such as a screw plug of a cylinder head of an automobile engine, is screwed, for example, a sealant such as an anaerobic adhesive is applied to the inside of the screw hole in advance. . The sealant hardens after the bolt is screwed and fills a gap between the screw hole and the bolt, thereby preventing water leakage and oil leakage due to vibration.
[0003]
In such a process, it is checked whether or not a sealant has been applied to the screw hole before the bolt is inserted into the screw hole. The sealant application inspection device used for the inspection is configured to irradiate the inner peripheral surface of the screw hole with light and detect the reflected light with a reflection type sensor.
[0004]
In the conventional sealant application inspection apparatus, the absolute value of the detected reflected light is compared with a predetermined threshold value, and when the absolute value of the reflected light exceeds the threshold value, for example, the sealant is applied. It is determined that the sealant has not been applied, and the sensor is turned off. If the threshold value has not been exceeded, it is determined that the coating has been performed, and the sensor is turned on to determine whether or not the sealant has been applied.
[0005]
[Problems to be solved by the invention]
In the case of performing a sealant application inspection using a reflective sensor, it is necessary to determine the setting of the sensor on / off region sensitivity before and after the application of the sealant. However, the gloss of the measurement surface fluctuates due to variations in the reflectivity in the manufacture of the screw holes and unevenness of the screw grooves and screw threads.
[0006]
In other words, the conventional method of always comparing a fixed threshold value with the absolute value of reflected light cannot detect only the change in reflected light due to the presence or absence of the application of the sealing agent, and depending on the irradiated portion of the screw hole, It is conceivable that the presence or absence of the application of the sealing material cannot be determined.
[0007]
The present invention has been made in view of such problems of the related art, and provides a sealant application inspection device capable of detecting the presence or absence of sealant application regardless of the state of a screw hole or a portion to be irradiated. The purpose is.
[0008]
[Means for Solving the Problems]
In order to achieve the above object, an invention according to claim 1 is a sealant application inspection apparatus for inspecting a sealant application state of a sealant application portion provided on a work, wherein the sealant application inspection apparatus includes a sealant before applying the sealant and a sealant. Reflected light measuring means for measuring the reflected light reflected by the sealant-applied portion after and after application of the agent, and a pre-application measurement value which is a value of the reflected light measured by the reflected light measuring means before applying the sealant. And, after applying the sealant, measured value calculating means for calculating the difference between the maximum measured value of the value of the reflected light measured during a predetermined sample time, the value calculated by the measured value calculating means, A sealant application determining means for determining that the sealant has been applied to the sealant application portion when the value is equal to or more than a predetermined value.
[0009]
With this configuration, the application of the sealant can be determined by comparing the measured value before the application of the sealant and the measured value after the application. Therefore, the inspection of the application of the sealant can be performed under a constant condition regardless of the change of the state or the shape of the application portion of the sealant.
[0010]
Further, with this configuration, it is possible to more reliably perform the sealing material application determination in a case where the measured value changes so as to increase by applying the sealing agent.
[0012]
The invention according to claim 2 is a sealant application inspection apparatus for inspecting a sealant application state of a sealant application portion provided on a workpiece, wherein the sealant application inspection apparatus performs the sealant application before and after the sealant is applied. Reflected light measuring means for measuring the reflected light reflected by the sealant application unit; measured values before application, which are the values of the reflected light measured by the reflected light measurement means before applying the sealant; Measurement value calculating means for calculating a difference from the minimum measured value among the reflected light values measured during a predetermined sample time, and the value calculated by the measurement value calculation means is equal to or greater than a predetermined value. And a sealant application judging means for judging that the sealant is applied to the sealant application portion.
[0013]
The measured value calculating means calculates a difference between a minimum measured value of the measured value after coating and a measured value before coating.
[0014]
With such a configuration, it is possible to more reliably perform the sealing material application determination in a case where the measured value changes so as to become smaller due to the application of the sealing agent.
[0015]
According to a third aspect of the present invention, the measured value calculating means further calculates a difference between a maximum measured value and a minimum measured value of the reflected light values measured during a predetermined sample time after the application of the sealant. The sealant application determining means further determines that the sealant is applied to the sealant application portion when the value calculated by the measurement value calculating means is equal to or greater than a predetermined value. The feature is characterized.
[0016]
With this configuration, the sealant application determination can be performed by comparing the maximum measured value and the minimum measured value among the measured values after application. Therefore, even when the measurement state of the reflected light changes before and after the application of the sealant, the application of the sealant can be determined under a constant condition regardless of the change.
[0017]
According to a fourth aspect of the present invention, in the sealant application inspection apparatus, the sealant application portion provided on the work is a screw hole.
[0018]
With this configuration, the sealant inspection device of the present invention can be used particularly for a sealing bolt that requires sealing.
[0019]
BEST MODE FOR CARRYING OUT THE INVENTION
An embodiment of the present invention will be described below with reference to the drawings.
[0020]
FIG. 1 is a diagram illustrating a measurement state of the sealant application inspection device according to the present embodiment. FIG. 2 is a block diagram for explaining the arithmetic unit shown in FIG. 1, and FIG. 3 is a diagram for explaining arithmetic performed by the arithmetic unit. 4 and 5 are diagrams showing display examples of the display shown in FIG.
[0021]
The sealant application device is a device for applying the sealant S to the inner peripheral surface of the screw hole P provided in the work, and includes a sealant applicator 10 for applying the sealant, and a sensor unit for irradiating the laser light 3. 1 and a microcomputer 2 as an arithmetic unit for processing information detected by the sensor unit 1.
[0022]
The sealant applicator 10 rotates with a rotor (not shown) while supplying the sealant to the application unit 10b by the sealant supply unit 10a, and applies the sealant to a width of about one screw thread. On the other hand, the sensor unit 1 is a reflection type optical sensor, and irradiates the laser light 3 to the inner peripheral surface in the screw hole P, detects this reflection light, and generates an analog signal corresponding to the amount of reflected light. .
[0023]
In the present embodiment, first, the sensor unit 1 detects reflected light in the screw hole P before the sealant is applied. After the detection is completed, the sealant applicator 10 applies the sealant to the screw holes P. The sensor unit 1 detects the reflected light from the screw hole P again after the application of the sealant. For this reason, the sealant applicator 10 and the sensor unit 1 are mounted on the same shift table having the XY axes, and are controlled so as to be alternately driven so as not to hit each other.
[0024]
As shown in FIG. 2, the sensor unit 1 is attached to the fiber sensor head 1a and is inserted into and removed from the screw hole P. Further, the microcomputer 2 has an A / D converter 22 and a CPU 21, and is further connected to the display 7 for displaying the result of the operation determination. An amplifier 5 is provided between the sensor unit 1 and the microcomputer 2, and amplifies an analog signal output from the sensor unit 1 so that the analog signal can be digitally converted by the A / D converter 22.
[0025]
A signal (detection signal) generated by the sensor unit 1 detecting the reflected light from the screw hole P is amplified by the amplifier 5 and output to the microcomputer 2. In this embodiment, since the sensor unit 1 detects the reflected light before and after the application of the sealant, the detection signal before the application of the sealant and the detection signal after the application are output to the microcomputer 2. become. The microcomputer 2 compares the detection signal before the application of the sealant with the detection signal after the application of the sealant, performs an arithmetic process, and inspects the presence or absence of the application of the sealant.
[0026]
Next, the procedure of the sealing material application inspection according to the present embodiment will be described with reference to FIG.
[0027]
1. Sensor Check First, the operation of the sensor unit 1 is checked to determine whether the sensor unit 1 operates normally. In this operation check, the output value of the sensor unit 1 outside the screw hole P, that is, the output value of the sensor unit 1 when the reflectance is 0, is measured, and the measured value is within a predetermined value range. If it is within, it is determined that the sensor unit 1 is operating normally, and the process proceeds to the next process.
[0028]
If the measured value is out of the predetermined value range, the process is interrupted as an abnormal state such as a sensor failure.
[0029]
2. If the pre-application confirmation sensor unit 1 is normal, then the reflected light before the sealing agent is applied to the screw hole P is measured. If the value of the reflected light obtained by this measurement is out of the range of the predetermined value, the inner surface of the screw hole P is dirty, or the screw thread or the like is not formed normally. The processing is interrupted because there is an abnormality in the screw hole P.
[0030]
In addition, when the value of the reflected light obtained by the measurement is within a predetermined range, the measured value of the reflected light is set as a measured value x1 before application and is a reference value for determining the presence or absence of application of the sealing material.
[0031]
3. Confirmation after application After the confirmation before application is completed, the reflected light after the sealing agent is applied to the screw hole P is measured. This measurement is performed for several seconds immediately after the application of the sealant, and observes that the applied sealant drips inside the screw hole P.
[0032]
4. Comparing the measured value x1 before application and the measured value of the reflected light after application, the presence or absence of application of the sealant is determined.
[0033]
FIG. 4 illustrates the process of the comprehensive determination.
In FIG. 4, the vertical axis shows the current value representing the detection signal, and the horizontal axis shows the time required for detection (sample time). In the example shown in FIG. 4, a sealant having a lower reflectance than the inner peripheral surface of the screw hole P is used. In general, the detection current value changes in a certain direction when a dark pigment or a sealant is applied to the convex surface to make it a convex part.However, since the sealant is liquid, it is detected by a shape difference. The current changes in various directions depending on the difference in the application amount and the detection time.
[0034]
The microcomputer 2 first inputs a measured value x1 before application from a detection signal before application of the sealant, and this value is shown in the figure. Further, the measured value after application is input from the detection signal after the application of the sealant, and this value is superimposed on the measured value x1 before application. In this embodiment, the sample time of the measured value x1 before application and the sample value of the measured value after application are both set to about 2 seconds. At this time, the measured value x1 before application is always constant during the sample time, whereas the measured value after application changes from the maximum measured value x2 to the minimum measured value x3. Such a change is caused by a change in the shape of the sealant applied on the inner peripheral surface of the screw hole P, which is dripped.
Incidentally, constants of an NG upper limit value D, an NG lower limit value E, and a slope value F are set in the microcomputer 2 in advance. The NG upper limit value D, the NG lower limit value E, and the slope value F are values that serve as criteria for judging the presence or absence of the application of the sealant from the measured values after application.
[0035]
That is, when the difference Y1 between the maximum measured value x2 and the measured value x1 before application is equal to or larger than the NG upper limit value D, it is determined that the sealant has been applied. Also, when the difference Y2 between the minimum measured value x3 and the measured value x1 before application is equal to or smaller than the NG lower limit value E, it is determined that the sealant is applied. Furthermore, when the absolute value of the difference between x2 and x3 is equal to or greater than the slope value F, it is determined that the sealant has been applied.
[0036]
The above three conditions for determining the application of the sealing material are summarized as follows.
[0037]
Y1 = maximum measured value x2—measured value before coating x1 (1)
Y2 = minimum measured value x3−measured value before coating x1 (2)
As
| Y1 |> D… Condition (1)
| Y2 |> E… Condition (2)
| X2 -x3 |> F ... condition (3)
If the measured value after application satisfies at least one of the conditions (1), (2) and (3), it is determined that the sealant has been applied.
[0038]
Such a determination is made using the fact that the change in reflected light due to the application of the sealant is sufficiently larger than the change in reflected light due to the portion where the laser light 3 is reflected.
[0039]
That is, when the value of Y1 is less than the NG upper limit value D, the difference between the maximum measured value x2 and the measured value before coating x1 is different at the portion where the laser beam 3 is reflected on the inner peripheral surface of the screw hole P. It is determined that the sealing agent has not been applied because it is due to this. On the other hand, when the value of Y1 is equal to or larger than the NG upper limit value D, it is determined that the difference between the maximum measured value x2 and the measured value x1 before application is due to the presence or absence of the application of the sealing material, and the sealing agent is applied. judge.
[0040]
Further, even when the absolute value of Y2 is equal to or less than the NG lower limit value E, it is assumed that the difference between the minimum measured value x3 and the measured value before coating x1 is due to the difference in the portion where the laser beam 3 is reflected. It is determined that the sealant has not been applied, and if the value of Y2 is equal to or greater than the NG lower limit E, it is determined that the sealant has been applied.
[0041]
Further, when the absolute value of x2−x3, that is, the absolute value of the difference between the maximum value and the minimum value of the measured values after application is equal to or greater than the slope value F, the change in the reflected light is caused by the fact that the sealant is used during the sample time. It is determined that the sealant has been applied because it is caused by dripping.
[0042]
The result of the above-described calculation determination is displayed on the display 7 to the operator. The display 7 exchanges signals with the display 7 so as to display the result of the sealant application inspection and input operator setting conditions, and to display the conditions to the operator together with the results of the arithmetic determination.
[0043]
Next, a display screen of the display 7 will be described with reference to FIGS.
[0044]
FIG. 5 is a diagram showing a screen on which an operator inputs and displays setting conditions. FIG. 6 is a diagram showing a screen displaying the inspection result of the application of the sealant.
[0045]
The screen for displaying the setting conditions includes a menu selection key 31, a setting condition table 32 for displaying the setting conditions, a numeric key 33 for inputting a numerical value to the setting condition table 32, a completion key 34 for inputting the setting completion, a setting key A current value reset key 35 for resetting all the values set in Table 32 and a next key 36 for calling the next screen are provided.
[0046]
The setting condition table 32 is divided into a pre-application setting value and an application setting value. If the setting value x1 before application is within the range of the lower limit value and the upper limit value in the column of the measurement value before application, the CPU 21 determines that the screw hole P before applying the sealant is formed normally, and Move on to processing.
[0047]
On the other hand, the NG lower limit E described with reference to FIG. 4 is displayed as the NG lower limit in the column of the measured value after application. In addition, the NG upper limit value indicates the NG upper limit value D, and the slope value indicates the value of the slope value F. The values of the NG upper limit value D, the NG lower limit value E, and the slope value F may be arbitrarily set by the operator from the screen of FIG. 5 or may be stored in the memory of the microcomputer 2 in advance. May be read.
[0048]
When the input of the setting conditions is completed on the screen of FIG. 5, the start of the sealant application inspection is instructed from another screen. When the sealant application inspection is completed, the screen shown in FIG. 6 appears, and the inspection result of the sealant application is displayed.
[0049]
The screen for displaying the inspection result has a menu selection key 41, an inspection result table 44 for displaying the inspection result, a previous key 42 for calling a previous screen or a next screen, and a next key 43.
[0050]
The inspection result table 44 can display the inspection results of three screw holes (screw plugs) at a time. The inspection result table 44 displays the measured value x1 before coating, the measured value after coating, the slope value obtained from the measured value after coating, and the judgment obtained by comparing each value with the setting condition of FIG. Is done.
[0051]
In the present embodiment, the post-application measurement is performed three times during the sample time of 2 seconds, and the three post-application measurement values are displayed. The judgment “OK” indicates that the sealant has been applied, and “NG” indicates that the sealant has not been applied.
[0052]
Hereinafter, a method of determining OK or NG will be specifically described with reference to the inspection result of the screw plug 1 in FIG. 6 as an example.
[0053]
According to FIG. 5, each set value is as follows.
[0054]
NG upper limit value D = 0.5
NG lower limit value E = 1.5
Slope value F = 0.3
Further, the following measured values are obtained from the inspection result table 44 (screw plug 1) in FIG.
[0055]
Measurement value before application x1 = 13.5 mA
Maximum measured value x2 = -6.3 mA
Minimum measured value x3 = -6.6 mA
Slope value F = 0.3
By substituting the measured values of the inspection result table 44 into the equations (1) and (2) to obtain Y1 and Y2,
| Y1 | = | -6.3-13.5 | = 19.7
| Y2 | = | -6.6-13.5 | = 20.1
Also,
| X3−x2 | = | −6.6 + 6.3 | = 0.3
It becomes.
[0056]
Therefore, the screw plug 1 satisfies the condition (1) of | Y1 |> D and the condition (2) of | Y2 |> E, and as described above, the conditions (1), (2) and (3) is that it is determined that the sealant has been applied if at least one is satisfied, so that a determination of "OK" is displayed in the determination column of the screw plug 1.
[0057]
FIG. 7 is a flowchart illustrating the above-described processing.
[0058]
The process of the present embodiment starts when the sealant application inspection device is turned on (S1). When the sealant application inspection device is turned on, it is determined whether an NG upper limit value D, an NG lower limit value E, a slope value F, and the like are set (S2). If the result of this determination is that a set value has been set, a sensor check subroutine is entered (S3), and it is checked whether the sensor unit 1 operates normally.
[0059]
This sensor check subroutine performs the following processing, for example.
[0060]
The sensor unit 1 irradiates the laser light 3 outside the screw hole P to generate a detection signal in a state of zero reflectance, and inputs this to the microcomputer 2. It is assumed that the microcomputer 2 previously stores a normal value range of the detection signal having the reflectance of 0. The microcomputer 2 compares the input detection signal of the reflectance of 0 with the stored normal value range. As a result of the comparison, if the detection signal is within a normal value range, it is determined that the sensor unit 1 is operating normally.
[0061]
On the other hand, when the detection signal of the reflectance 0 is out of the range of the normal value, the fact that the sensor unit 1 is abnormal is displayed on the display 7 and the process is terminated.
[0062]
As a result of the check by the sensor check subroutine, when it is determined that the sensor unit 1 is normal, the pre-application measurement is performed, and the pre-application measurement value x1 is measured (S4). The microcomputer 2 determines whether or not the measured pre-application value x1 falls within the range of the lower limit value A and the upper limit value B considered to be normal as the pre-application value x1 (S5). If the pre-application measurement value x1 is within the normal range, it is determined that the screw hole P is formed normally, and a sealant is applied to the screw hole P (S6). If the pre-application measurement value x1 is out of the range of the normal value, a work abnormality is displayed on the display 7 and the process ends (S15).
[0063]
After the application of the sealant to the screw hole P is completed, the sealant application inspection device performs measurement after the application (S7). In the present embodiment, three measurements are performed after the application, but the number of times may be more if the time required for the measurement is within a range of several seconds.
[0064]
When the three post-application measurements are all completed, the detection signals of the three post-application measurements are compared to detect the maximum measurement value x2 and the minimum measurement value x3 (S8). Further, | Y1 | and | Y2 | are calculated from the detected maximum measured value x2, minimum measured value x3 and measured value x1 before coating (S9), and | Y1 | is replaced with the NG upper limit D and (S10), | Y2 | Is compared with the NG lower limit value E to determine which is larger (S11).
[0065]
As a result of the determination in Steps 10 and 11, if one of the conditions that | Y1 | is larger than the NG upper limit value D or | Y2 | is larger than the NG lower limit value E is satisfied, the sealant is applied. Is determined to be OK, and an OK determination is displayed on the display 7 (S16). After the judgment and display, it is determined whether or not there is still a next screw plug to be inspected (S14). If there is no next screw plug, the process ends. If there is a next screw plug, the flow returns to step 2 to apply the sealant again and to inspect it.
[0066]
If the result of any of the determinations in Steps 10 and 11 is NO, the difference between the maximum measured value x2 and the minimum measured value x3 is further obtained, and this absolute value is compared with the slope value F (S12). ). As a result, if the absolute value of the difference between the maximum measured value x2 and the minimum measured value x3 is larger than the slope F, an OK determination is displayed (S16). If the absolute value of the difference between the maximum measured value x2 and the minimum measured value x3 is smaller than the slope F, it is determined that there is no OK determination in any of the calculation processes (S10), (S11), and (S12), and the NG determination is made. Is displayed (S13). If there is no next screw plug, the process is terminated. If there is a next screw plug, the flow returns to step 2 to apply the sealant again and to inspect it.
[0067]
According to the above-described embodiment, the application of the sealant can be determined by comparing the measured value x1 before application with the maximum measured value x2 or the minimum measured value x2 after application.
[0068]
Therefore, it is possible to inspect the application of the sealant under a certain condition regardless of the state or the shape of the concave portion. In addition, even when the measured value changes so as to increase due to the application of the sealing agent, or when the measured value changes so as to decrease, the sealing material application determination can be performed more reliably.
[0069]
Further, in the present embodiment, the sealant application determination can be performed by comparing the maximum measured value x2 and the minimum measured value x3 among the measured values after application.
[0070]
Therefore, for example, even when the measurement state of the reflected light changes due to a difference in the insertion angle, the depth, and the like of the sensor head 1 before and after the application of the sealant, the sealant is kept under a constant condition regardless of the change. Can be determined. Further, when the sealant application determination is performed only by this method, it is not necessary to perform the pre-application measurement, so that the process of the sealant application inspection can be further simplified.
[0071]
Further, the present embodiment is applied to the application of the sealing material in the screw hole P, thereby preventing the loosening of the screw, such as the cylinder head of the engine, which is particularly likely to be loosened due to the vibration, and improving the reliability of the engine. The safety of the car can be improved.
[0072]
【The invention's effect】
According to the first aspect of the present invention, it is possible to inspect the application of the sealant under a constant condition regardless of a change in the state or shape of the sealant application portion provided on the work.
Further, according to the first aspect of the present invention, it is possible to more reliably perform the sealing material application determination in a case where the measured value changes so as to increase by applying the sealing agent.
[0074]
According to the second aspect of the present invention, the inspection of the application of the sealant can be performed under a constant condition regardless of a change in the state or the shape of the application portion of the sealant provided on the work.
In addition, it is possible to more reliably perform the sealing material application determination in a case where the measured value changes so as to be reduced by the application of the sealing agent.
[0075]
According to the third aspect of the invention, even when the measurement state of the reflected light changes before and after the application of the sealant, the application of the sealant can be determined under a constant condition regardless of the change.
[0076]
According to the invention described in claim 4, the sealant inspection device of the present invention can be used particularly for a sealing bolt that requires sealing.
[Brief description of the drawings]
FIG. 1 is a diagram illustrating a measurement state of a sealant application inspection device according to an embodiment of the present invention.
FIG. 2 is a block diagram illustrating an arithmetic unit shown in FIG.
FIG. 3 is a diagram illustrating a procedure of a sealant application inspection according to the embodiment of the present invention.
FIG. 4 is a view for explaining processing of a sealant application inspection performed by the arithmetic unit shown in FIG. 1;
FIG. 5 is a diagram showing a display example of the display device shown in FIG.
FIG. 6 is a diagram showing another display example of the display device shown in FIG.
FIG. 7 is a flowchart illustrating processing performed in the present embodiment.
[Explanation of symbols]
DESCRIPTION OF SYMBOLS 1 ... Sensor part 2 ... Microcomputer 3 ... Laser light 5 ... Amplifier 7 ... Display 10 ... Sealant applicator 21 ... CPU
22 A / D converter P Screw hole S Sealant

Claims (4)

A sealant application inspection device for inspecting a sealant application state of a sealant application portion provided on a work,
Reflected light measuring means for measuring the reflected light reflected at the sealant applied portion before and after the application of the sealant,
The pre-application measurement value, which is the value of the reflected light measured by the reflected light measuring means before applying the sealant, and the maximum measured value of the reflected light values measured during the predetermined sample time after the application of the sealant the difference measurement value calculating means for calculating a and,
A sealant application determining unit that determines that the sealant is applied to the sealant-applied portion when the value calculated by the measurement value calculating unit is equal to or greater than a predetermined value. Agent application inspection device. A sealant application inspection device for inspecting a sealant application state of a sealant application portion provided on a work,
Reflected light measuring means for measuring the reflected light reflected at the sealant applied portion before and after the application of the sealant,
The pre-application measurement value, which is the value of the reflected light measured by the reflected light measuring means before applying the sealant, and the minimum measured value of the reflected light measured during a predetermined sample time after the application of the sealant. Measurement value calculating means for calculating the difference between
A sealant application determining unit that determines that the sealant is applied to the sealant-applied portion when the value calculated by the measurement value calculating unit is equal to or greater than a predetermined value. Agent application inspection device.   The measurement value calculation means further calculates the difference between the maximum measurement value and the minimum measurement value of the reflected light values measured during the predetermined sample time after the application of the sealant,
  The sealant application determination unit further determines that the sealant is applied to the sealant application unit when the value calculated by the measurement value calculation unit is equal to or greater than a predetermined value. The sealant application inspection device according to claim 1 or 2, wherein: The sealant application inspection device according to any one of claims 1 to 3, wherein the sealant application portion provided on the work is a screw hole .

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