JP7469657B2 - Surface treatment system for steel objects and surface treatment method using the same - Google Patents

Description

The present invention relates to a system for performing surface treatments such as carburizing on the surface of a steel workpiece, and a surface treatment method using the system.

Generally, steel parts (steel workpieces) are cleaned after forging or casting to remove oil and other contaminants that have adhered to the surface of the workpiece. After that, various surface treatments such as carburizing and nitriding are performed to increase the surface hardness of the workpiece (see Patent Documents 1 and 2).

When performing surface treatment on steel workpieces, reactive gases such as hydrocarbon gases and ammonia gas are introduced into a dedicated treatment chamber, which is equipped with an inlet for introducing the reactive gas from outside and an outlet for discharging the gas inside the treatment chamber to the outside.

During surface treatment, the efficiency of surface treatment of each workpiece varies greatly depending on the contact state between the workpiece placed in the treatment chamber and the reactive gas. In other words, the contact state between the reactive gas and the workpiece is greatly influenced by the size, number, and loading form of the workpieces placed in the treatment chamber, resulting in variation in the effectiveness of surface treatment between individual workpieces.

In addition, the loading configuration of the objects to be treated in the treatment chamber is often the same as that of the previous cleaning process, and the loading configuration of the objects to be treated is determined by understanding the size and number of objects to be treated in the cleaning process.

JP 2013-112877 A JP 2015-4111 A

However, even if the loading form (packaging) of the workpieces changes, the flow of the reactive gas in the treatment chamber during surface treatment hardly changes at all. Therefore, the effect of surface treatment is greater for workpieces that are located along the flow path of the reactive gas, and the effect of surface treatment is inevitably smaller for workpieces placed in places where the reactive gas hardly passes through. In other words, the effect of surface treatment varies depending on the packaging form of the workpieces.

The present invention aims to provide a surface treatment system and a surface treatment method using the same that can reduce variation in the treatment effect during the subsequent surface treatment process by accurately measuring the specific loading conditions (packing style) such as the size and quantity of the objects to be treated in the treatment chamber of a cleaning device or the like.

The surface treatment system for steel workpieces of the present invention is broadly composed of a cleaning device and a surface treatment device. The cleaning device has at least a cleaning chamber in which the steel workpieces are cleaned, and a liquid level detector that measures the distance to the liquid level in the cleaning chamber. The surface treatment device also has a surface treatment chamber in which the surface of the steel workpieces is treated, a gas inlet provided in the surface treatment chamber for introducing gas from the outside, and a gas outlet for discharging gas from within the surface treatment chamber to the outside.

The cleaning device may further include a receiving unit that collects information on the distance measured by the liquid level detection unit, a calculation unit that processes the change over time in the distance to the liquid level based on the information collected by the receiving unit, and a judgment unit that judges the packaging state of the workpiece from the results of the calculation by the calculation unit. The liquid level detection unit is a liquid level detection device that detects changes in the liquid level using infrared rays, ultrasound, an LED, a laser, or a float.

Next, the invention of a surface treatment method using this surface treatment system for steel objects is a surface treatment method having a first step of acquiring information about the specific packaging form of the steel object using the cleaning device described above, a second step of sending the packaging form information of the steel object acquired in the first step to the surface treatment device described above, and a third step of performing surface treatment on the steel object based on the packaging form information of the steel object sent in the second step. For this surface treatment, one of the following treatment forms can be selected: carburizing, nitriding, or carbonitriding.

The surface treatment system for steel workpieces of the present invention measures the change in the level of the cleaning liquid in the cleaning chamber of the cleaning device at predetermined time intervals using a liquid level sensor or the like, and performs an arithmetic process (calculate) on the change in the liquid level over time. From the calculated change in the liquid level over time, the cross-sectional change in the height direction within the cleaning chamber can be accurately determined, and the installation state of the steel workpiece can be inferred. The results can be used to reduce the variation in the surface treatment effect between steel workpieces in the subsequent surface treatment process.

FIG. 1 is a front view of a cleaning device 10 constituting a surface treatment system of the present invention. XX cross-sectional view of the cleaning device 10 shown in FIG. 2 is an example of an operation screen of a control panel attached to the cleaning device 10 shown in FIG. 1 . 2 is an example of an operation screen of a control panel attached to the cleaning device 10 shown in FIG. 1 .

The form of the surface treatment system of the present invention will be described with reference to the drawings. Figure 1 is a front view (viewed from the A arrow in Figure 2) of a vacuum degreasing and cleaning device 10 constituting a part of the surface treatment system of the present invention, and Figure 2 is a cross-sectional view of the X-X line of the vacuum degreasing and cleaning device 10 shown in Figure 1. The vacuum degreasing and cleaning device 10 shown in Figures 1 and 2 comprises a cleaning chamber 1 in which multiple objects to be treated are cleaned inside, pipes 2A, 2B for supplying or discharging cleaning liquid into the cleaning chamber 1, multiple legs 3, 3 for supporting the entire cleaning chamber 1 from below, suction pipes 4A, 4B for connecting to a vacuum pump (not shown) to create a reduced pressure atmosphere inside the cleaning chamber 2, and a liquid level detector 5 for detecting the liquid level of the cleaning liquid in the cleaning chamber 1.

The liquid level detector 5 detects the level of the cleaning liquid in the cleaning chamber 1 and can instantly measure the distance between the liquid level detector 5 and the liquid level to calculate the amount of cleaning liquid filled in the cleaning chamber 1. The liquid level detector 5 can also be connected to a receiving unit, a calculation unit, and a judgment unit (not shown) installed outside the cleaning chamber 1 via wired or wireless electrical communication means to construct a system that can measure information related to the packaging state of the workpiece using this set.

When the liquid level detection unit 5 is a liquid level sensor, it can measure the distance between the liquid level of the cleaning liquid supplied to the cleaning chamber 1 and the sensor (liquid level detection unit 5). The distance from the liquid level to the sensor (liquid level detection unit 5) can be measured at a predetermined time interval, such as every 0.1 seconds or every 10 seconds. Information (data) regarding the distance to the liquid level measured by the liquid level detection unit 5 is first sent via wire or wirelessly to the aforementioned receiving unit, where the measurement results are collected.

The measured distance information sent to the receiving unit is processed by the aforementioned calculation unit as the time change (increase per unit time) of the collected distance information. The aforementioned judgment unit judges (discriminates) the state of the packaging of the workpieces in the cleaning chamber 1 from the calculation results of the calculation unit.

Next, the associated equipment of the vacuum degreasing and cleaning apparatus 10 shown in Figure 1 will be described with reference to the drawings. The vacuum degreasing and cleaning apparatus, which constitutes part of the surface treatment system of the present invention, is equipped with equipment that has the function of acquiring information about the workpiece to be treated and analyzing that information to utilize it in the next surface treatment process. An example of the operation screen on the control panel associated with the vacuum degreasing and cleaning apparatus 10 shown in Figure 1 is shown in Figures 3 and 4.

The operation screen 20 shown in FIG. 3 is an example of a screen that acquires various information about the workpiece obtained from an image sensor such as a CCD camera attached to the vacuum degreasing and cleaning apparatus 10 shown in FIG. 1. The image 21 shown in the figure is a monitor of the cleaning liquid filled in the cleaning chamber 1 of the vacuum degreasing and cleaning apparatus 10 shown in FIG. 1, and the circulation state of the used cleaning liquid and heat transfer oil. The image 22 shown in the figure represents the state in which the entire workpiece is photographed by the image sensor installed at the top of the cleaning chamber 1 of the vacuum degreasing and cleaning apparatus 10 shown in FIG. 1. From the image captured by this image sensor, the number of columns, rows, stages, number, and height of the workpiece can be analyzed and calculated using dedicated software.

Image 23 in the figure shows the weight of the entire workpiece, the surface area, surface area ratio, and volume ratio of the entire workpiece, calculated from the information about the workpiece analyzed in image 22. Image 24 in the figure shows the supply time of the cleaning liquid when empty and fully loaded in the cleaning chamber 1 of the vacuum degreasing and cleaning device 10 shown in FIG. 1, etc., based on the information about the entire workpiece calculated in image 23.

The operation screen 30 shown in FIG. 4 is a screen that displays information about the workpiece obtained from the liquid level detection unit 5 attached to the vacuum degreasing and cleaning apparatus 10 shown in FIG. 1 in addition to the image sensor described above. Image 31 shows the supply status (supply status) of the cleaning liquid in the cleaning chamber 1 of the vacuum degreasing and cleaning apparatus 10. Image 32 shows the change over time in the supply status of the cleaning liquid in the cleaning chamber 1, and shows the result of calculating the liquid supply speed for each supply time from the start to the end of liquid supply.

Image 33 shows the calculated liquid supply time, liquid supply speed, estimated height, estimated volume, estimated weight, bulk density, maximum cross-sectional area, and number of mounting stages of the workpiece, derived from the analysis results of Image 32. Image 34 shows the change in the height from the bottom to the liquid surface in the cleaning chamber 1 and the cross-sectional area of the workpiece from the start to the end of liquid supply.

The liquid level detector constituting the packaging shape measuring device of the present invention is not limited to the liquid level sensor shown in FIG. 1, and may be any device that can instantly measure the distance between the liquid level detector and the liquid level, such as a measuring device that uses a float or other device, in addition to sensors that use various methods such as infrared, ultrasonic, LED, and laser.

REFERENCE SIGNS LIST 1 cleaning chamber 2A, 2B piping 3 leg 4A, 4B suction piping 5 liquid level detector 10 vacuum degreasing cleaning device 20 monitor screen showing information on object to be cleaned 21-24 images on monitor screen showing information on object to be cleaned 30 monitor screen showing information on cleaning conditions 31-34 images on monitor screen showing information on cleaning conditions

Claims (4)

A surface treatment system for steel works comprising at least a cleaning device including a cleaning chamber in which a cleaning liquid is used to clean the steel workpiece inside, and a liquid level detection unit which measures the distance to the liquid level of the cleaning liquid in the cleaning chamber; and a surface treatment apparatus including a surface treatment chamber in which surface treatment of the steel workpiece is performed, a gas inlet port provided in the surface treatment chamber for introducing gas from the outside, and a gas outlet port for discharging the gas within the surface treatment chamber to the outside, wherein the cleaning device further includes a receiving unit which collects information relating to the distance measured by the liquid level detection unit, a calculation unit which calculates the change in the distance to the liquid level over time based on the information collected by the receiving unit, and a judgment unit which judges the packaging state of the workpiece from the results of the calculation by the calculation unit. The surface treatment system for steel workpieces as described in claim 1, characterized in that the liquid level detection unit is a liquid level detection device that detects changes in the liquid level using either infrared rays, ultrasound, an LED, a laser, or a float. 3. A surface treatment method using the surface treatment system for steel workpieces as defined in claim 1 or 2 , comprising: a first step of acquiring information on the packaging appearance of the steel workpiece with the cleaning device; a second step of sending the information on the packaging appearance of the steel workpiece acquired in the first step to the surface treatment device; and a third step of performing surface treatment on the steel workpiece based on the information on the packaging appearance of the steel workpiece sent in the second step. 4. The method for treating a surface of a steel workpiece according to claim 3 , wherein the surface treatment is any one of carburizing, nitriding and carbonitriding.

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