JPS58109848A - Method and apparatus for controlling liquid quantity of magnetic powder - Google Patents

Abstract

PURPOSE:To keep the liquid quantity and concentration of magnetic powder constant, by supplying a liquid and the magnetic powder predetermined for its liquid quantity until the liquid face is raised to the standard face at the time when the liquid face of a liquid vessel of the magnetic powder is lowered from a standard level by a predetermined fixed quantity. CONSTITUTION:A magnetic powder liquid vessel 1 is provided with a standard level sensor 8a and a liquid face level sensor 8b arranged on the part lower than the sensor 8a by a fixed distance, and a liquid feeder 20 raising the liquid face to the position of the sensor 8b by supplying a liquid such as water by output signals of the sensor 8a and 8b at the time when the liquid face is lowered to the position of the sensor 8b is provided. The liquid face of the liquid is kept constant always by this feeder 20, and a fixed quantity of the magnetic powder corresponding to the quantity of liquid to be supplied at that time is supplied by a magnetic powder feeder 12 and this apparatus is constituted so that the quantity of the magnetic powder is made to be a fixed ratio always for the quantity of the liquid.

Description

DETAILED DESCRIPTION OF THE INVENTION The present invention relates to a magnetic particle liquid supply device used in a magnetic particle flaw detector, and more particularly to a method for controlling the amount of liquid in a magnetic particle liquid tank and an apparatus for carrying out the method.

Conventionally, in magnetic particle flaw detection, magnetic particle liquid with a certain concentration is prepared in advance and stored in a magnetic particle liquid tank, and the magnetic particle liquid is taken out and used for flaw detection as needed. Magnetic powder liquid is reduced due to adhesion to the material to be inspected, so in order to keep the liquid amount in the magnetic powder liquid tank constant, conventionally, magnetic powder liquid was added using the method described below.

In other words, the conventional methods of addition are: 1) Measure the concentration of magnetic powder liquid and supply additional magnetic powder to compensate for the shortage.

■Measure the concentration of magnetic powder liquid, create magnetic powder liquid with a concentration that can be corrected, and supply this additionally.

■ This is mainly a manual method that involves periodically supplying additional magnetic powder liquid at a fixed concentration.

However, among the above conventional methods, methods (2) and (3) in particular are difficult to implement because the calculation of the amount of additional magnetic powder to be supplied or the concentration of magnetic powder liquid to be supplied is complicated. However, this method is also complicated in that it requires measuring the amount of magnetic powder corresponding to the amount of liquid to be supplied one by one, and furthermore, all of the above methods are performed manually. Therefore, there were problems such as not only extremely poor work efficiency, but also the concentration of the magnetic particle liquid being easily fluctuated, which in turn made the magnetic particle flaw detection ability unstable.

Therefore, in order to solve the above-mentioned problems, it has been considered to automate the above-mentioned method. However, when automating the methods ① and ① above, it is necessary to measure the concentration of magnetic powder liquid, so the measurement is
If the pear-shaped sedimentometer specified in 8) is used for this purpose, it will detect precipitates other than magnetic particles, such as chips and scale brought in by the magnetic particle liquid flowing back from the material to be inspected, resulting in a high concentration. The reality is that accurate concentration cannot be obtained, and truly effective magnetic particle concentration measurements that take into account contamination of the liquid and deterioration of magnetic particle particles have not been achieved.
Therefore, even if methods (1) and (2) above can be automated, it is extremely difficult to suppress fluctuations in the concentration of magnetic powder liquid within an acceptable range, and the reality is that this method has not been put to practical use. Furthermore, in order to automate the method (2) above, it is necessary to measure the amount of Shun's magnetic powder commensurate with the amount of additional liquid, but the equipment required to do so is
The device is complicated and expensive because it requires a function to calculate the amount of additional liquid based on the amount of remaining liquid, a function to calculate the amount of magnetic particles commensurate with the calculated amount of additional liquid, and an accurate magnetic particle measuring device. There is also the problem that magnetic powder has poor fluidity, so it is difficult to measure it accurately.

In any case, in the past, in order to keep the amount of magnetic particle liquid constant, each time the magnetic particle liquid was added, the concentration would fluctuate, and the reality was that the magnetic particle flaw detection ability was unstable.

Therefore, the inventors of the present invention have conducted extensive research in order to accurately and easily control the amount of magnetic powder liquid using a simple device, and as a result, fluctuations in the degree of magnetic powder liquid do not occur significantly in normal flaw detection work. Although the concentration was within the permissible range, it was discovered that by supplying the insufficient amount additionally, the magnetic powder liquid level would change significantly, and the concentration could exceed the permissible concentration range. By additionally supplying a fixed amount of liquid and a corresponding fixed amount of magnetic powder, there is no need to measure the amount of liquid and magnetic powder to be added each time, and therefore the amount of magnetic powder liquid and its concentration can be easily kept constant. This invention was realized based on the recognition that it is possible to maintain a high temperature.

That is, an object of the present invention is to provide a control method that can easily and accurately keep the amount of magnetic powder liquid and its concentration constant, and a device with a simple configuration for implementing the method. The feature of this method is that when the liquid level in the magnetic powder tank drops by a predetermined amount from the reference level, water or other liquid is supplied to the magnetic particle tank until the liquid level reaches the reference level, and the supplied liquid This can be done by supplying a predetermined amount of magnetic powder, and in this way, the supply a
Since m is always constant and a certain proportion of magnetic powder is supplied accordingly, it is virtually impossible to supply magnetic powder liquid with a specified concentration, and the amount of liquid in the magnetic powder liquid tank is The liquid and magnetic powder concentration can be kept constant, and the amount of liquid and magnetic powder to be supplied can be determined in advance.
Additional work can be done easily. In addition, the device of the present invention has provided a reference level sensor and a liquid level sensor placed a certain distance below the standard level sensor in the magnetic particle liquid tank, and the liquid level is determined to be at the liquid level according to the output signals of these sensors. A liquid supply device is provided that supplies liquid such as water to raise the liquid level to the reference level sensor position when the level drops to the sensor level, so that the amount of liquid supplied is always constant. A magnetic powder feeder that supplies a constant amount of magnetic powder corresponding to the supplied amount is characterized by being configured such that the supplied amount of magnetic powder is always a constant ratio to the supplied amount of liquid, Ru.

Embodiments of the present invention will be described below with reference to the accompanying drawings.

First, an embodiment of the apparatus of the present invention will be described with reference to FIG. 1. FIG. 1 is a schematic diagram showing the overall configuration, and the bottom of the magnetic powder liquid tank 1 has a concave shape that smoothly continues from the left and right side walls. The outflow pipe 2 is installed so as to open at its most central part, and near the opening, a discharge pipe 3 opens toward the left and right side walls, and the outflow pipe 2 is connected to the motor. The discharge pipe 3 is connected to the suction port of a pump 5 driven by the pump 4, and the discharge pipe 3 is connected to the discharge port of the pump 5 via a three-way valve 6. The magnetic powder is circulated by the pump 5 and stirred by K to prevent the magnetic particles from settling and staying, and to keep the concentration uniform. An outflow pipe 7 is connected to the three-way valve 6, and by switching the three-way valve 6, the magnetic powder liquid is used for flaw detection.

In the magnetic powder liquid tank 1tca, a plurality of sensors 8 (eight in the figure) for detecting the liquid level are installed vertically at intervals of a constant liquid volume, and these sensors 8 have the same configuration and the same function. However, the top 7th row should be -8.
is used as a reference level sensor 8s in its operation, and nine sensors 8 are used as liquid level sensors 8b), and these sensors 8 are connected to a control circuit 9.This control circuit 90 actions will be described below in sequence.

Above the magnetic powder liquid tank 1, a magnetic powder supply device 12 is arranged, which mainly includes a magnetic powder tank 10 and a measuring meter 11 connected to the lower end opening thereof.

That is, the connection port of the measuring meter 11 to the magnetic powder tank 10 is connected to the upper partition plate 14 which is moved back and forth by the cylinder 13.
Each cylinder 1
3.15 is operated alternately based on the output signal of the control circuit 9, and by alternately opening and closing the upper and lower can openings of the measuring meter 11, a certain amount of magnetic particles cut out from the magnetic particle tank 10 into the measuring meter 11 is transferred. is supplied by dropping into the magnetic powder liquid tank 1. Here, to explain the capacity of the measuring meter 11, the capacity is as follows: 8 m of the reference level sensor 11
The volume of liquid such as water corresponding to the volume of the magnetic powder liquid tank 1 between the magnetic powder tank 1 and the liquid level sensor 8b immediately below the liquid level sensor 8b is set to a volume that measures an amount of magnetic powder to form a magnetic powder liquid with a specified immersion degree.
Therefore, for example, when the second sensor 8b from the top (third sensor from the top for the sensor 8 as a whole) is operated as the liquid level sensor 8b, magnetic particles are transferred to the weighing meter 11.
It is designed to feed the needle twice. The magnetic particle tank 10 is equipped with a magnetic particle level detector 17, and the magnetic particle level detector 17 is connected to the control circuit 9, so that when the amount of magnetic particles in the magnetic particle tank 10 falls below a certain amount, A buzzer or warning light is now used to notify when the amount of magnetic particles is decreasing.

Further, above the magnetic powder liquid tank 1, there is a liquid supply device 20 consisting of a liquid supply pipe 18 and an open/close pulp 19 provided in the middle thereof.
9, when one of the liquid level sensors 8b detects the liquid level in the magnetic powder liquid tank 1, the pulp 19 is opened by an output signal from the control circuit 9, and as a result of the liquid level rising, the reference level is reached. When the sensor 81 detects the liquid level, the valve 19 is closed in response to an output signal from the control circuit 9, thereby supplying the insufficient amount of liquid such as water to the magnetic powder liquid tank IK.

Further, an additive supply device 21 is attached to the magnetic powder liquid tank l. The additive supply device 21 is for dispersing and mixing the additives in a liquid such as water, and the supply device 21 supplies the additives in the main tank 22 to the sub tank 25 via the pulp 24 with the pump 23. By opening the open/close pulp 26 connected to the sub-tank 25 for a predetermined period of time, a fixed amount of additive is supplied from the sub-tank 25 into the magnetic powder liquid tank 1 according to the opening time. A liquid level detector 27 is attached to the sub-tank 25, and when the level of the additive in the sub-tank 25 falls below the position where the liquid level detector 27 is attached, the liquid level detector 27 A signal is output to the control circuit 9, and the signal output from the control circuit accordingly drives the pump 23 and opens the pulp 24, thereby pumping the additive from the main tank 22 to the sub tank 25.

In addition, the reference numeral 28 in FIG. 1 is a pipe for returning the magnetic powder liquid flowing back from the inspection table (not shown) to the magnetic powder liquid tank 1.

Next, the operation of the apparatus constructed as described above, that is, the method of the present invention will be explained. First, one of the liquid level sensors 8b, for example, the first stage (
In order to function the liquid level sensor 8b (second from the top in terms of sensor 8 as a whole), a changeover switch (not shown) in the control circuit 9 is switched.In this state, the magnetic powder liquid in the magnetic powder liquid tank 1 is As a result of use, when the liquid level in the magnetic powder liquid tank 1 falls to the level of the liquid level sensor 8b, the liquid level sensor 8b outputs a detection signal, and in response, the control circuit 9 outputs a magnetic powder supply signal.

B, outputs a liquid supply signal C and an additive supply signal.

One cylinder 13 in the magnetic powder feeder 12 operates once based on the magnetic powder supply signal AK to open the connection port between the magnetic powder tank 10 and the weighing meter 11 from the upper partition plate 14 for a few seconds, and then opens the connection port again. The measuring meter 11 is closed, thus supplying magnetic powder to its full capacity, and then the other cylinder 15 is operated by the magnetic powder supply signal B, and the lower end opening of the measuring meter 11 is opened by the lower partition plate 16, and the cumulative amount is Masu 11
The magnetic powder inside falls and is supplied into the magnetic powder liquid tank 1.

Since the capacity of the meter 11 is set to the above-described volume, the amount of magnetic powder supplied in this case is of course commensurate with the amount of liquid to be additionally supplied to the magnetic powder liquid tank IK.

In addition, in parallel with the above-described supply of magnetic powder, the opening/closing pulp 19 in the liquid supply device 20 is opened in response to the liquid supply signal C, and liquid such as water is supplied to the magnetic powder liquid tank 1. As a result, the liquid in the magnetic powder liquid tank 1 is When the liquid level reaches the reference level, that is, the reference level sensor 8
When it rises to the position a, the reference level sensor 8m outputs a signal, and accordingly, the control circuit 9 outputs a signal to the opening/closing pulp 19, so that the opening/closing pulp 1
9 is closed and the supply of liquid is stopped.

As mentioned above, since the capacity of the meter 11, that is, the amount of magnetic powder supplied, is a preset constant ratio to the amount of the supplied liquid, the magnetic powder liquid with a substantially specified concentration is eventually transferred to the magnetic powder. This means that the magnetic powder liquid has been supplied into the liquid tank 1, and as a result, the amount of magnetic powder liquid in the magnetic powder liquid tank 1 increases to the original reference amount without causing any fluctuation in its concentration.

As described above, it is necessary to additionally supply a prescribed amount of additive in conjunction with the additional supply of magnetic powder and liquid, but in the above device, at the same time as the magnetic powder and liquid are supplied, the control circuit
The opening/closing pulp 26 is opened for the time necessary to supply an amount of additive corresponding to the amount of magnetic powder and liquid supplied by the additive supply signal from the magnetic powder liquid tank 1. will be additionally supplied.

In addition, in the above-mentioned device, when the amount of magnetic particles in the magnetic particle tank 10 falls below the specified amount, the magnetic particle level detector 17 attached to the magnetic particle tank 10 detects it and outputs an alarm signal E, and the result is When the buzzer sounds or the warning light lights up, you can know that there is a lack of violet in the magnetic powder, and when the amount of additive in the sub-tank 25 falls below the specified amount, the liquid level sensor attached to the sub-tank 25 The device 27 detects this and outputs a supply signal F to the control circuit 9, and as a result, the control circuit 9 outputs a drive signal G to the pump 23 and pulp 24 in the additive supply device 21.

Based on this, the valve 24 opens and the pump 23 operates, so the additive is transferred to the main tank 22.
The sub-tank 25 can be replenished from there.

Naka, the code in Figure 1! indicates a signal for switching the three-way valve 6, and symbol J indicates a signal for operating the motor 4 which communicates with the magnetic powder liquid tank 1 and drives the pump 5.

By the way, in the above embodiment, the liquid level sensor 8b
Although the first level sensor 8b is made to function, the same effect can be obtained even if any other liquid level sensor 8b is made to function. That is, for example, if the third level sensor 8b in FIG. 1 (fourth from the top for the entire sensor 8) is activated, the amount of liquid to be supplied, that is, the liquid After the surface level sensor 8b outputs a signal to start supplying liquid, until the reference level sensor 8b outputs a signal and stops supplying the liquid, the amount of liquid to be supplied is as follows in the above-described embodiment. Therefore, it is necessary to supply the magnetic powder and additives three times as much as in the above embodiment. To do this, an additional liquid amount memory is provided in the control circuit 9, and the measuring needle 11 in the magnetic powder feeder 12 is operated three times based on the output signal of the memory, and a certain amount of magnetic particles is additionally supplied into the magnetic powder liquid tank 1 three times. However, the opening/closing pulp 26 in the additive supply device 21 may be opened for three times the opening time in the above embodiment according to the output signal of the additional liquid volume memory, thereby tripling the supply amount of the additive. , and 5, the supply amount of magnetic powder, liquid, and additive will be tripled, and the mutual ratio will be as specified.
Therefore, the magnetic powder liquid concentration can be kept constant.

FIG. 2 is a diagram showing the concentration change between the nine conventional methods described above and the present invention. As shown in FIG. However, according to this invention, as shown in Fig. 2 (
As shown in 6), the concentration hardly changes and can be kept within an acceptable range.

As is clear from the above explanation, according to the method of the present invention, when the liquid level in the magnetic powder liquid tank drops by a predetermined amount from the reference level, liquid such as water is pumped until the liquid level reaches the reference level. Since the magnetic powder is supplied into the magnetic powder liquid tank and a predetermined amount of magnetic powder is supplied to the amount of the supplied liquid, the amount of supplied liquid and magnetic powder is a predetermined constant amount and the ratio is always the same. Therefore, since this is essentially the same as additionally supplying magnetic particle liquid with a specified concentration, magnetic particle liquid can be replenished without causing concentration fluctuations, and as a result, magnetic particle flaw detection and inspection performance can be stabilized. Further, according to the device of the present invention, there is a reference level detector that detects the reference level of the liquid level in the magnetic powder liquid tank, and a liquid level detector that detects that the liquid level has decreased by a certain amount from the reference level. and when the liquid level drops by a predetermined amount from the reference level, 1- The output signals from these detectors operate the liquid supply device and the magnetic powder supply device, and the liquid level reaches the reference level. Since the structure is configured to supply liquid up to 100% and also supply magnetic powder at a fixed ratio to the amount of supplied liquid, there is no need for a function to measure the concentration or to calculate the amount of liquid and magnetic particles to be supplied. The structure can be simplified and made cheaper, and since there is no need to measure the concentration, it is possible to stabilize the concentration even if scale or chips are mixed into the existing magnetic powder liquid. can.

[Brief explanation of the drawing]

FIG. 1 is a schematic diagram showing one embodiment of the device of the present invention, and FIG.
Figure (4) is a diagram showing the concentration change in the case of conventional dredging.
FIG. 2(B) is a diagram showing density changes when using the method of the present invention. 1...Magnetic powder liquid tank, 8...Sensor, 8 Heat...Reference level sensor, 8b...Liquid level sensor, 11
--Measuring needle, 12...Magnetic powder feeder, 20...Liquid feeder. Applicant Toyota Motor Corporation Representative Patent Attorney Taketo Toyota (1 person)

Claims (1)

[Claims] 1. When the liquid level in the magnetic powder tank drops by a predetermined amount from a reference level, water or other liquid is supplied into the magnetic powder tank until the liquid level reaches the reference level. Also, a method for controlling the amount of magnetic powder liquid in which the amount of magnetic powder is supplied into the magnetic powder liquid tank in a predetermined proportion to the amount of the supplied liquid. 2. A reference level detector that detects the reference level of the liquid level in the magnetic powder liquid tank, a liquid level detector that detects when the liquid level has decreased by a predetermined amount from the reference level, and a A liquid supply device that supplies a liquid such as water into a magnetic powder liquid tank until it reaches the illll heavy liquid level based on a detection signal, and A magnetic powder liquid amount control device comprising: a magnetic powder supply device that supplies magnetic particles into the magnetic powder liquid tank.