JP7054140B2 - Nozzle clogging inspection method and equipment - Google Patents

Description

Application of Article 30, Paragraph 2 of the Patent Law Published at "Mechatronics Japan 2017" held at Port Messe Nagoya International Exhibition Center on October 18, 2017.

The present invention relates to an inspection method for detecting nozzle clogging for cleaning various workpieces such as metal products and a nozzle clogging inspection device.

Conventionally, various cleaning devices that automatically clean various workpieces with a nozzle that ejects a high-pressure cleaning liquid have been used. Automatic cleaning with a cleaning liquid contributes to the efficiency of the cleaning process, but if the nozzle holes are clogged with foreign matter, the cleaning effect cannot be obtained, and a process of inspecting the nozzle holes for clogging is required before the cleaning process. rice field. In this inspection process, the presence or absence of foreign matter is generally visually inspected, and the pressure and flow rate of the cleaning liquid are measured to inspect for clogging.

In addition, as disclosed in Patent Document 1, as a method of detecting clogging of the cleaning nozzle of the analyzer, the capacitance between the suction nozzle and the pipe is measured by an electrode provided between the suction nozzle and the pipe. There was a way to detect clogging. In this detection method, a detection means for detecting whether or not the capacitance exceeds a predetermined threshold is provided, and first, when the suction nozzle is not clogged, the time until the capacitance exceeds the predetermined threshold is measured. do. Then, at the time of nozzle clogging determination, the time up to the time when the capacitance exceeds a predetermined threshold is measured, and when the time difference between the two is equal to or greater than the predetermined time difference threshold, it is determined by the inspection method that the suction nozzle is clogged. be.

Further, as disclosed in Patent Document 2, as a method of detecting the clogging of the dispensing nozzle of the analyzer, the pressure change at the time of suction or ejection of the dispensing nozzle in the pipe connected to the dispensing nozzle is detected. , A detection method is also proposed in which the number of peaks of the pressure change waveform is calculated from the detected pressure change, and the dispensing nozzle inner diameter is dirty or clogged based on the calculated number of peaks.

International Publication WO2009 / 00324 Japanese Unexamined Patent Publication No. 2010-14364

In the visual inspection among the above-mentioned conventional techniques, oversight may occur in the case of a narrow nozzle hole, and the inspection efficiency is not good. Furthermore, if the cleaning results vary due to oversight or clogging of some nozzle holes, it also hinders the improvement of product quality. Therefore, there is a demand for an automated nozzle clogging inspection method as disclosed in Patent Documents 1 and 2, which enables high-precision inspection.

However, in the case of the detection method disclosed in Patent Document 1, an electrode is provided for measurement, and if the number of nozzle holes is large, the structure becomes complicated and the cost of the inspection device increases. There is. Furthermore, since the time it takes for the cleaning liquid to reach the electrodes is compared, it is difficult to capture subtle differences, and it is difficult to detect nozzle clogging, especially in the case of a device that injects a high-pressure cleaning liquid with a thin nozzle.

The nozzle clogging inspection method disclosed in Patent Document 2 detects a change in pressure at the time of suction or ejection of the nozzle, but the change in pressure in the pipe connected to the nozzle is subtle, and in the case of Patent Document 1. Similarly, in the case of a device having a thin nozzle or a device having a large number of nozzles, it is difficult to accurately detect the clogging of the nozzles.

The present invention has been made in view of the above-mentioned problems of the prior art, and an object of the present invention is to provide a nozzle clogging inspection method and an apparatus capable of easily and accurately inspecting by a relatively simple method at low cost. do.

The present invention is a nozzle clogging inspection method for detecting clogging of the cleaning nozzle of a cleaning device provided with a plurality of cleaning nozzles, wherein the flow rate of the cleaning liquid to the cleaning nozzle is not clogged. The initial integrated value of the results of multiple measurements within a fixed time is used as the threshold value in the normal state, and the flow rate after the flow rate of the cleaning liquid becomes constant at the time of measuring nozzle clogging is measured multiple times within the fixed time. The measurement step to be performed, the measurement value integration step for integrating the measurement results of the plurality of times to calculate the measurement integration value, and the measurement value integration step are repeated a plurality of times to obtain the integrated average value which is the average value of the measurement integration values. A nozzle provided with a step of calculating the integrated average value to be obtained and a nozzle clogging determination step of comparing the integrated average value with the threshold value in a normal state without nozzle clogging and determining that the nozzle is clogged when there is a difference of a predetermined value or more. It is a clogging inspection method.

The nozzle clogging is measured immediately after the flow rate of the cleaning liquid becomes constant, the measurement step is performed 40 times or more, and the measurement results are integrated. Further, when measuring the nozzle clogging, it is preferable to perform the measured value integration step 10 times or more.

Further, the threshold value in the normal state keeps the pressure of the cleaning liquid supplied to the cleaning nozzle within a constant range, and keeps the flow rate after the flow rate of the cleaning liquid becomes constant in a state where the nozzle is not clogged. The initial integrated value of the measurement result is calculated by measuring multiple times within the time, and the calculation of the initial integrated value of the multiple measurement results within the fixed time is repeated a plurality of times, and the nozzle is not clogged. The initial average value of the initial integrated value is obtained, and this initial average value is used as the threshold value in the normal state without nozzle clogging.

Further, the present invention is a nozzle clogging inspection device for detecting clogging of the cleaning nozzle of a cleaning device provided with a plurality of cleaning nozzles, the cleaning liquid supply having a pump for supplying the cleaning liquid and a pipe connected to the pump. A member, a constant pressure control device provided in the middle of the pipe and maintaining the pressure of the cleaning liquid supplied to the cleaning nozzle within a certain range, and a flow sensor for detecting the flow rate of the cleaning liquid supplied to the cleaning nozzle. A state in which the output of the flow sensor is stored, the stored flow rate is integrated, and an arithmetic processing device for calculating the average value of the integrated values is provided. The arithmetic processing apparatus is in a state where the cleaning nozzle is not clogged. Then, the initial integrated value of the measurement results of a plurality of times within a fixed time of the flow rate is set as the threshold value in the normal state, and the flow rate after the flow rate of the cleaning liquid becomes constant at the time of measuring the nozzle clogging is used for the fixed time. Measured multiple times within, calculate the measured integrated value of the measurement result, repeat this multiple times to obtain the integrated average value which is the average value of the measured integrated value, and the integrated average value is in a normal state without nozzle clogging. This is a nozzle clogging inspection device for determining nozzle clogging when there is a difference of a predetermined value or more as compared with the above-mentioned threshold value.

According to the nozzle clogging inspection method and device of the present invention, clogging of the cleaning nozzle to be inspected can be accurately detected by a simple method, and even in a cleaning device having a large number of nozzle holes in the cleaning nozzle, one nozzle is used. Even if the hole is clogged, it can be detected accurately. As a result, the automation of the cleaning process by the cleaning nozzle can be made more efficient, and the cleaning work efficiency can be further improved. Further, reliable cleaning can be performed without clogging of the cleaning nozzle, cleaning defects can be eliminated, the occurrence of defective products can be prevented, and the quality of the cleaned products can be stabilized.

It is a piping diagram of the nozzle clogging inspection apparatus of one Embodiment of this invention. It is a front view of the cleaning apparatus provided with the cleaning nozzle which is inspected by the nozzle clogging inspection method of this embodiment. It is a vertical sectional view (a) and a top view (b) which show the cleaning nozzle inspected by the nozzle clogging inspection method of this embodiment. It is a flowchart which shows the nozzle clogging inspection method of this embodiment.

Hereinafter, an embodiment of the nozzle clogging inspection method and the nozzle clogging inspection apparatus of the present invention will be described with reference to FIGS. 1 to 4. The nozzle clogging inspection device 10 of this embodiment inspects the clogging of the cleaning nozzle 20 of the cleaning device 14 for removing dust and dirt on the inner surface 12a and the outer surface 12b of the processed product 12 which is various metal products.

As shown in FIG. 2, in the cleaning device 14 in which nozzle clogging is inspected by the nozzle clogging inspection device 10, each device is arranged in a substantially rectangular housing 15, and each device is attached to a frame 16 of the housing 15. ing. A plurality of, for example, three cleaning cover cylinders 18 are concentrically rotatably provided in the cleaning portion 17 at the upper part of the housing 15 in the cleaning cover cylinder 18 around the axis of rotation. , The nozzle member 22 is housed. In the cleaning cover cylinder 18, the nozzle member 22 is rotatably provided around the central axis of the cleaning cover cylinder 18. A control unit 46 and the like, which will be described later, are provided on the side of the housing 15, and the control unit 46 and an arithmetic processing unit (not shown) are connected to a monitor 19 for displaying an arithmetic result and the like, which will be described later. Further, a liquid crystal display may be arranged on the upper part of the housing 15 to display the calculation result or the like.

As shown in FIGS. 2 and 3, the cleaning unit 17 of the cleaning device 18 is provided with a nozzle member 22 having a large number of nozzle holes 24 formed toward the inner wall of the processed product 12 and the cleaning cover cylinder 18. The nozzle member 22 is formed in a hollow shape and has an internal space 23, is assembled in a U shape, and is rotatably attached to the cleaning portion 17 of the cleaning device 14. As shown in FIG. 3, the U-shaped nozzle member 22 includes a pair of vertical portions 22a and 22b and a single horizontal portion 22c. A plurality of nozzle holes 24 for injecting the cleaning liquid W diagonally downward on the drawing are formed on the inner and outer surfaces of one vertical portion 22a, and the cleaning liquid W is injected diagonally inward on the other vertical portion 22b. A nozzle hole 24 and a nozzle hole 24 for injecting the cleaning liquid W diagonally downward and outward are provided. Further, the horizontal portion 22c is also formed with a nozzle hole 24 for injecting the cleaning liquid W directly below.

A central nozzle portion 22d extending vertically downward is provided in the central portion of the horizontal portion 22c of the nozzle member 22, and the central nozzle portion 22d also has an internal space 23 and is a nozzle that injects the cleaning liquid W from the horizontal direction and the lower end portion. A hole 24 and a nozzle hole 24 for ejecting downward from the lower end portion are provided. An upper nozzle portion 25 for injecting the cleaning liquid W diagonally downward from the side is provided at the upper end portion of one vertical portion 22a of the nozzle member 22, and the nozzle hole 24 is formed so as to face downward. The nozzle member 22 is rotatably attached to a rotation shaft 26 provided in the vertical direction, and is rotated at a predetermined rotation speed by a drive device (not shown).

The rotary shaft 26 is formed in a cylindrical shape, is provided with an inlet 29 for the cleaning liquid W, and is connected to a pipe (not shown). The internal space 27 of the rotation shaft 26 communicates with the internal space 23 of the horizontal portion 22c, and the internal space 23 of the horizontal portion 22c communicates with the internal spaces 23 of the vertical portions 22a and 22b and the central nozzle portion 22d, respectively. It is connected to the nozzle hole 24. Further, a bottom cleaning portion 28 is provided on the bottom surface of the cleaning portion 17 so as to face the central nozzle portion 22d, and the bottom cleaning portion 28 is also formed hollow to have an internal space 23, and a nozzle hole opened upward. 24 is formed. The bottom cleaning portion 28 is provided with an inlet 29 for the cleaning liquid W on the back surface side facing the central nozzle portion 22d, and a pipe (not shown) is connected to the bottom cleaning portion 28.

As shown in the piping diagram of FIG. 1, the cleaning device 14 is provided with a pump 30 for supplying the cleaning liquid W and a supply pipe 32 connected to the pump 30. The pump 30 and the supply pipe 32 constitute a cleaning liquid supply member. The pump 30 is connected to the cleaning liquid tank 34 in which the cleaning liquid W is stored via a suction pipe 35. The supply pipe 32 is provided from the pump 30 to the cleaning nozzle 20, and a filter 36 for filtering the cleaning liquid W is provided on the way.

A constant pressure control device 40 is provided on the downstream side of the filter 36 of the supply pipe 32. The constant pressure control device 40 includes a flow rate sensor 42 that detects the flow rate of the supply pipe 32, a pressure sensor 44 that detects the pressure of the cleaning liquid W of the supply pipe 32, and a proportional valve 45 connected between the flow rate sensor 42 and the filter 36. It also includes a control unit 46 such as a PLC that controls the proportional valve 45. The opening degree of the proportional valve 45 is controlled by the control unit 46 based on the signal of the pressure sensor 44. The control is adjusted so that the pressure of the cleaning liquid W of the supply pipe 32 is within a certain range, and when the pressure of the cleaning liquid W is high, the opening degree is increased and the pressure is decreased. A return pipe 47 for returning the cleaning liquid W to the cleaning liquid tank 34 is connected to the proportional valve 45, and the pressure of the supply pipe 32 is adjusted by returning the cleaning liquid W to the return pipe 47. A cleaning liquid valve 43 is provided between the pressure sensor 44 and the cleaning nozzle 20, and is formed so that the supply and stop of the cleaning liquid W to the cleaning unit 17 can be switched.

Further, a relief valve 48 is connected to the supply pipe 32 connected to the pump 30, the relief valve 48 is connected to the cleaning liquid tank 34 via the relief pipe 49, and the cleaning liquid W is cleaned by the relief operation during standby. It is returned to the tank 34. Further, a discharge pipe 38 is provided between the cleaning unit 17 and the cleaning liquid tank 34, and the cleaning liquid W used in the cleaning cover cylinder 18 is returned to the cleaning liquid tank 34 and is formed so as to be circulated.

The constant pressure control device 40 includes an arithmetic processing unit (not shown) that stores the output of the flow rate sensor 42, integrates the stored flow rates, and calculates the average value of the integrated values. The arithmetic processing device sets the flow rate of the cleaning liquid W immediately after the flow rate of the cleaning liquid W becomes constant, for example, 1.5 seconds after the operation of the pump 30, for a certain period of time in a state where the nozzle is not clogged. For example, there is a program that measures a plurality of times in 2 seconds, for example, 200 times every 1/100 second, integrates the measurement results, and repeats this integration operation 20 times to calculate the average of the integrated values.

Next, a nozzle clogging inspection method using the constant pressure control device 40 of this embodiment will be described. The constant pressure control device 40 controls so as to cancel the pressure loss due to the clogging of the filter 36 in order to detect the decrease in the flow rate due to the clogging of the nozzle. The flow rate of the cleaning nozzle 20 is calculated by the following formula (1).
Q = 0.658 × √p × n × d ² / η ² (1)
Here, flow rate: QL / min, pressure: p MPa, number of holes: n, hole diameter: d mm, coefficient: η
From the formula (1), since the nozzle hole diameter and the coefficient of the cleaning nozzle 20 are constant, if the pressure can be controlled to be constant, the decrease in the flow rate can be regarded as the clogging of the nozzle hole. Therefore, first, a threshold value for determining nozzle clogging is obtained. The threshold value is the value of the flow rate of the supply pipe 32 in a state where the nozzle is not clogged, and is obtained as follows.

After visually confirming that the cleaning nozzle 20 is not clogged, the pump 30 is operated to start supplying the cleaning liquid W to the cleaning nozzle 20. The flow rate of the supply pipe 32 becomes substantially constant, for example, 1.5 seconds after the operation of the pump 30. After the flow rate of the cleaning liquid W becomes constant, the constant pressure control device 40 measures the flow rate of the supply pipe 32 by the flow rate sensor 42, for example, every 1/100 second for 2 seconds, and integrates the measurement results. The integrated value here is stored as an initial integrated value, and this is repeated for a certain cycle. For example, in 40 seconds, the operation of obtaining the initial integrated value of the integrated result is repeated 20 times. Then, the initial average value, which is the average value of the initial integrated values of 20 cycles, is obtained in 40 seconds without nozzle clogging. The constant pressure control device 40 stores this initial average value as a threshold value in a normal state without nozzle clogging. In addition to the above, the threshold value in the normal state without nozzle clogging may be a threshold value obtained by one calculation as long as it is a value that becomes the threshold value for the subsequent nozzle clogging inspection.

Next, when cleaning the processed product 12, a nozzle clogging inspection is performed in advance. In the nozzle clogging inspection, as shown in the flowchart of FIG. 4, the pump 30 is operated, the supply of the cleaning liquid W is started, and for example, 1.5 seconds after the flow rate becomes constant, the flow rate from the flow rate sensor 42 has elapsed. Data is measured and acquired at regular intervals, for example, every 1/100 second (s1). The acquisition of the flow rate data is performed for a certain period of time, for example, 2 seconds, and the acquisition of the flow rate data is stopped (s2). Here, the flow rate data should be as many as 200, but any number may be sufficient as long as the number of subtle changes in the flow rate becomes apparent, and 40 or more may be sufficient. After the measurement step in which the flow rate data is acquired for a certain period of time, all the values of the measurement results are integrated and stored in the internal memory as the measured integrated values (s3).

Further, the measured value integration step for calculating the above-mentioned measured integrated value is repeated a plurality of times, for example, 20 times to obtain an integrated average value which is an average value of the measured integrated values (s4). It is better to acquire a large number of integrated values, but it is sufficient if at least 10 or more are acquired. Then, after the integrated average value calculation step for obtaining the integrated average value, the integrated average value is compared with the threshold value in the normal state without nozzle clogging, and when the difference between the two exceeds a predetermined abnormal alarm value, the nozzle Judge as a blockage. When it is determined that the nozzle is clogged, the arithmetic processing unit of the cleaning device 14 issues an abnormality (s5). In the nozzle clogging determination step for notifying an abnormality, the abnormality may be displayed on the monitor 19, or the abnormality may be notified by another display device, sound, or the like.

According to the nozzle clogging inspection method and device of this embodiment, clogging of the nozzle hole 24 of the cleaning nozzle 20 of the cleaning device 14 to be inspected can be accurately detected by a simple method. In particular, in the cleaning nozzle 20 provided with a large number of nozzle holes 24, even if one nozzle hole 24 is clogged, it can be accurately detected. Thereby, the cleaning process by the cleaning nozzle 20 can be performed more accurately and efficiently. In addition, the automation of the cleaning device 14 can be further promoted, and the cleaning work efficiency can be further improved. Moreover, reliable cleaning is possible without clogging of the cleaning nozzle 20, cleaning defects can be eliminated, defects such as cleaning defects of the processed product 12 can be prevented, and quality can be stabilized.

The nozzle clogging inspection method and apparatus of the present invention are not limited to the above-described embodiment, and the period and the number of times for integrating the flow rate are appropriately set, and the integration is repeated to take the average of the integrated values. The number can be selected as appropriate.

10 Nozzle clogging inspection device 12 Processed product 14 Cleaning device 17 Cleaning unit 18 Cleaning cover cylinder 20 Cleaning nozzle 22 Nozzle member 24 Nozzle hole 30 Pump 32 Supply pipe 40 Constant pressure control device 42 Flow sensor 42
44 Pressure sensor 45 Proportional valve 46 Control unit W Cleaning liquid

Claims (5)

A nozzle clogging inspection method for detecting clogging of the cleaning nozzles of a cleaning device provided with a plurality of cleaning nozzles.
When the cleaning nozzle is not clogged, the initial integrated value of the measurement results of the flow rate of the cleaning liquid to the cleaning nozzle a plurality of times within a certain period of time is set as the threshold value in the normal state.
At the time of measuring nozzle clogging, a measurement step in which the flow rate after the flow rate of the cleaning liquid becomes constant is measured a plurality of times within the fixed time, and a measurement value in which the measurement results are integrated and the measured integrated value is calculated. The integration step, the integrated average value calculation step for obtaining the integrated average value which is the average value of the measured integrated values by repeating the measured value integration step a plurality of times, and the integrated average value as the threshold value in a normal state without nozzle clogging. A nozzle clogging inspection method comprising a nozzle clogging determination step for determining a nozzle clogging when there is a difference of a predetermined value or more in comparison. The nozzle clogging inspection method according to claim 1, wherein the nozzle clogging is measured immediately after the flow rate of the cleaning liquid becomes constant, the measurement step is performed 40 times or more, and the measurement results are integrated. The nozzle clogging inspection method according to claim 1 or 2, wherein the measured value integration step is performed 10 times or more at the time of measuring the nozzle clogging. The threshold value in the normal state maintains the pressure of the cleaning liquid supplied to the cleaning nozzle within a certain range, and the flow rate after the flow rate of the cleaning liquid becomes constant in a state where the nozzle is not clogged is within a certain period of time. The initial integrated value of the measurement result is calculated by measuring multiple times with, and the calculation of the initial integrated value of the multiple measurement results within a certain period of time is repeated a plurality of times to perform the initial integrated value without nozzle clogging. The nozzle clogging inspection method according to 1, 2 or 3, wherein an initial average value of values is obtained, and this initial average value is used as a threshold value in a normal state without nozzle clogging. A nozzle clogging inspection device for detecting clogging of the cleaning nozzle of a cleaning device provided with a plurality of cleaning nozzles.
A cleaning liquid supply member having a pump for supplying the cleaning liquid and a pipe connected to the pump, and a cleaning liquid supply member.
A constant pressure control device provided in the middle of the pipe and maintaining the pressure of the cleaning liquid supplied to the cleaning nozzle within a certain range.
A flow rate sensor that detects the flow rate of the cleaning liquid supplied to the cleaning nozzle, and
It is provided with an arithmetic processing unit that stores the output of the flow rate sensor, integrates the stored flow rate, and calculates the average value of the integrated values.
The arithmetic processing unit is
With the cleaning nozzle not clogged, the initial integrated value of the results of multiple measurements of the flow rate within a certain period of time is set as the threshold value in the normal state.
At the time of measuring nozzle clogging, the flow rate after the flow rate of the cleaning liquid becomes constant is measured a plurality of times within the fixed time, the measurement integrated value of the measurement result is calculated, and this is repeated a plurality of times to perform the measurement integration. The integrated average value, which is the average value of the values, is obtained, the integrated average value is compared with the threshold value in a normal state without nozzle clogging, and when there is a difference of a predetermined value or more, it is determined that the nozzle is clogged. Nozzle clogging inspection device.

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