JP7591968B2 - METHOD FOR PRE-TREATING METAL WORK AND METAL WORK - Google Patents

Description

The present invention relates to a method for pre-treating a metal workpiece and a metal workpiece.

For example, cast workpieces are subjected to various heat treatments, and it is necessary to distinguish whether the workpiece has been heat treated or not. Regarding the presence or absence of such heat treatment, in the following Patent Document 1, a monochromatic light is irradiated onto the workpiece, and the presence or absence of heat treatment is distinguished from the amount of light reflected by the surface of the workpiece. However, the method of distinction is complicated, as it is necessary to set a threshold value for the amount of light depending on the shape and surface condition of the workpiece.

JP 2018-151386 A

The objective of the present invention is to easily ensure the traceability of workpieces.

The pretreatment method for metal workpieces according to the present invention includes a marking process in which a mark whose color changes irreversibly due to heat treatment is applied to the workpiece before heat treatment.

According to this method, a mark is applied to the workpiece. The workpiece is then heat treated. The color of the mark changes as a result of the heat treatment. If the color of the mark has changed, the workpiece has been heat treated. Conversely, if the color of the mark has not changed, the workpiece has not been heat treated. By checking the color of the mark applied to the workpiece, it is possible to determine whether the workpiece has been heat treated or not.

The pretreatment method for metal workpieces according to the present invention includes an identifier applying process for applying a base identifier to the workpiece before heat treatment, a marking process for applying a mark on the base identifier, the color of which changes irreversibly due to heat treatment, and a checking process for checking with a sensor whether the mark is applied correctly on the base identifier. In the checking process, when the sensor cannot read the base identifier, it is determined that the mark is applied correctly, and when the sensor can read the base identifier, it is determined that the mark is not applied correctly.

According to this method, a base identifier is attached to the workpiece, and a mark is attached on the base identifier. If the sensor cannot read the base identifier in the check process, it is determined that the mark is attached correctly on the base identifier. The workpiece is then heat-treated. The color of the mark changes due to the heat treatment. If the color of the mark has changed, the workpiece has been heat-treated. Conversely, if the color of the mark has not changed, the workpiece has not been heat-treated. By checking the color of the mark attached to the workpiece, it is possible to determine whether the workpiece has been heat-treated or not. On the other hand, if the sensor reads the base identifier in the check process before heat treatment, it is determined that the mark is not attached correctly on the base identifier. Then, the workpiece is not sent to the heat treatment process. In this way, by attaching a mark on the base identifier and checking with a sensor, it is easy to determine whether the mark has been left on. And it is possible to prevent a workpiece without a mark from being heat-treated.

In particular, it is preferable to further assign a product identifier to the workpiece in addition to the base identifier in the identifier assignment process. According to this method, in the identifier assignment process, a product identifier and a base identifier are assigned to the workpiece. After that, a mark is placed above the base identifier, but no mark is placed above the product identifier. This further ensures the traceability of the workpiece.

The metal workpiece according to the present invention is also provided with a mark whose color changes irreversibly upon heat treatment.

According to this configuration, the color of the mark changes due to heat treatment. If the color of the mark has changed, the workpiece has been heat treated. Conversely, if the color of the mark has not changed, the workpiece has not been heat treated. By checking the color of the mark affixed to the workpiece, it is possible to determine whether the workpiece has been heat treated or not.

The metal workpiece according to the present invention also includes a base identifier and a mark provided on the base identifier, which covers at least a portion of the base identifier so that the sensor cannot read the base identifier.

With this configuration, at least a portion of the base identifier is covered by the mark, and the sensor cannot read the base identifier. Therefore, the sensor can easily determine whether or not a mark has been attached to the workpiece. Before heat treatment, the mark is attached on top of the base identifier, so the sensor can easily check whether the mark has been left on. After heat treatment, the base identifier and the mark remaining on it indicate that the workpiece has undergone the correct process, making it easy to confirm.

As described above, workpiece traceability can be easily ensured.

4 is a flowchart showing a process for manufacturing a workpiece in one embodiment of the present invention. FIG. 3 is an enlarged view of part A in FIG. 2, where (a) shows the state before heat treatment and (b) shows the state after heat treatment. 1A is a perspective view showing an identifier imparting step of a pretreatment method in one embodiment of the present invention, and FIG. 1B is an enlarged view of a main part of a workpiece after the identifier imparting step. FIG. 4A to 4C are enlarged views of the main parts of the workpiece after the marking process. 13A and 13B are perspective views showing a checking step of the pretreatment method. 13 is a flowchart of the checking process.

The following describes a pretreatment method for a metal workpiece and a metal workpiece according to one embodiment of the present invention with reference to the drawings. FIG. 1 shows an example of a manufacturing method for a workpiece 1. The workpiece 1 may be made of various materials such as cast or forged, but the workpiece 1 in this embodiment is made of cast, particularly die-cast. The material of the workpiece 1 is also arbitrary, but it is, for example, an aluminum alloy. The manufacturing method includes a casting process 10, a stamping process 11 which is an identifier-imparting process, a marking process 12, a first check process 13 before heat treatment, a heat treatment process 14, and a second check process 15 after heat treatment. In this embodiment, the stamping process 11, the marking process 12, and the first check process 13 are pretreatment methods performed before heat treatment.

<Work 1>
The shape of the workpiece 1 may vary, and the size may also vary. An example of the workpiece 1 is shown in Fig. 2. A product code 2, a product symbol 3, and a base code 4 are provided on the surface of the workpiece 1. The product code 2, the product symbol 3, and the base code 4 are engraved on the workpiece 1 in an engraving process 11. The product code 2, the product symbol 3, and the base code 4 are provided on the material surface (cast surface) that is not machined among the surfaces of the workpiece 1, but may also be provided on the machined surface.

<Product Code 2>
The product code 2 is for identifying each individual workpiece 1 and is a product identifier. The product code 2 is preferably a two-dimensional code. The product code 2 may be of a stack type or a matrix type, but is preferably of a matrix type, and more preferably is a data matrix code. The product code 2 is read by a second sensor 22 (code reader) described later. The information in the product code 2 includes, for example, a number indicating the type of product, a number for each individual workpiece 1, a manufacturing location, a manufacturing date, etc.

<Product Code 3>
The product code 3 is, for example, a number or an alphabet, and is a product identifier together with the product code 2. The product code 3 can be visually confirmed by an operator. The information indicated by the product code 3 may be, for example, a part of the information of the product code 2, or may be information different from the product code 2. It is preferable that the product code 3 is attached to the workpiece 1 separately from the product code 2, so that an operator can visually read various information of the workpiece 1.

<Base chord 4>
The base code 4 is a code different from the product code 2 and is a base identifier. The base code 4 is preferably arranged near the product code 2, but may be located away from the product code 2. The base code 4 is readable by a second sensor 22 described later. The base code 4 is preferably a two-dimensional code. The base code 4 may be a two-dimensional code of the same type as the product code 2, or may be a two-dimensional code of a different type from the product code 2, but is preferably a two-dimensional code of a different type from the product code 2. The base code 4 may be a stack type or a matrix type, but is preferably a matrix type, and is more preferably a quick response code. The information of the base code 4 may be related to the work 1 or may not be related to the work 1. The information of the base code 4 may be, for example, numbers or letters, or may be, for example, a single alphabet or number.

<Mark 5>
As shown in Fig. 3, a mark 5 is attached on the base code 4. The mark 5 covers at least a part of the base code 4. The mark 5 is attached on the base code 4 so that the base code 4 cannot be read by the second sensor 22. The mark 5 may cover the entire base code 4 or may cover only a part of the base code 4, but covers at least the base code 4 to such an extent that reading by the second sensor 22 is impossible. Therefore, the mark 5 has a color that makes it impossible to read the base code 4. The mark 5 may be provided in various ways, but is preferably painted.

The color of the mark 5 changes irreversibly due to the heat treatment of the workpiece 1. FIG. 3(a) shows the state of the mark 5 before the color change, and FIG. 3(b) shows the state of the mark 5 after the color change. The mark 5 is visible before the heat treatment, and is also visible after the heat treatment. That is, the mark 5 is visible both before the color change and after the color change. The mark 5 is preferably opaque. The color change of the mark 5 may be a change in hue, brightness, or saturation. The color of the mark 5 is preferably a chromatic color. The paint of the mark 5 may be oil-based or water-based, but is preferably oil-based. The colorant of the paint of the mark 5 may be a dye or a pigment, but is preferably a dye because the color changes easily. For example, a product name "Paint Marker" by Mitsubishi Pencil Co., Ltd. is suitable for applying the mark 5.

<Engraving process 11>
FIG. 4(a) shows the marking process 11. The work 1 is shown in a simplified form. The work 1 is cooled after casting and then sent to the marking process 11. In the marking process 11, the marking device 20 marks the product code 2, product symbol 3, and base code 4 on the surface of the work 1 by laser marking. FIG. 4(b) shows the product code 2, product symbol 3, and base code 4 marked on the work 1. The product code 2, product symbol 3, and base code 4 are preferably marked by one marking device 20, but may be marked by two or more marking devices 20. In addition, the marking device 20 is preferably provided with a first sensor 21 (code reader). The first sensor 21 checks whether the product code 2, product symbol 3, and base code 4 are marked on the work 1. If any of the product code 2, product symbol 3, and base code 4 is not marked on the work 1, the first sensor 21 outputs an error signal. When the error signal is output, it is preferable that, for example, a warning sound or an error message is issued. If any of the product code 2, product symbol 3, and base code 4 is not engraved on the work 1, the work 1 is not sent to the next marking process 12.

<Marking step 12>
After the first sensor 21 confirms that the product code 2, product symbol 3, and base code 4 are engraved on the work 1, the work 1 is sent to the marking process 12. The marking process 12 is shown in Figure 5. In the marking process 12, a mark 5 is applied on the base code 4 of the work 1 by a marker 30. The application of the mark 5 may be automatic or manual.

Figure 6 shows the identification marking portion of the workpiece 1 after the marking process 12. Figure 6(a) shows an OK state where the mark 5 has been applied normally onto the base code 4. Figure 6(b) shows an NG state where the mark 5 has been applied away from the base code 4. Figure 6(c) shows an NG state where the mark 5 has not been applied.

<First check step 13>
After the marking step 12, the work 1 is sent to a first check step 13. The first check step 13 is a step for checking whether or not the mark 5 is attached to the work 1 before the heat treatment. In detail, in the first check step 13, it is checked whether or not the mark 5 is normally attached on the base code 4 of the work 1.

As shown in FIG. 7(a), the workpiece 1 is placed in front of the second sensor 22. The second sensor 22 attempts to read the base code 4. When the mark 5 is properly placed on the base code 4 as shown in FIG. 6(a), the second sensor 22 is unable to read the base code 4 due to the obstruction of the mark 5. On the other hand, when the mark 5 is placed away from the base code 4 as shown in FIG. 6(b), or when the mark 5 is not placed as shown in FIG. 6(c), the second sensor 22 can read the base code 4.

Figure 8 shows a flowchart of the first check process 13. First, the base code 4 is read by the second sensor 22 as described above (S1). If the second sensor 22 cannot read the base code 4, it is determined that the mark 5 is correctly placed on the base code 4. In other words, it is determined that the marking is OK (S2), and the process proceeds to reading the next product code 2 (S4). On the other hand, if the second sensor 22 can read the base code 4, it is determined that the mark 5 is not correctly placed. In other words, it is determined that the marking is NG (S3).

When the second sensor 22 reads the base code 4, the information on the base code 4 is sent from the second sensor 22 to the computer 23. When the computer 23 receives the information on the base code 4, it determines that marking is NG, displays an error on the display screen, and outputs a warning sound. The worker can determine that the mark 5 has not been placed correctly from the error display on the display screen and the warning sound, and then places the mark 5 on the work 1 correctly and then reads the base code 4 again.

If the second sensor 22 cannot read the base code 4, the information on the base code 4 is not sent from the second sensor 22 to the computer 23. In this case, the computer 23 determines that marking is OK. For example, "Marking OK" is displayed on the display screen, and the worker looks at the display screen and proceeds to reading the next product code 2.

If it is determined that the marking is OK, the worker then positions the product code 2 in front of the second sensor 22 as shown in FIG. 7(b) and has the second sensor 22 read the product code 2. As described above, the first sensor 21 reads the product code 2 in the marking process 11, thereby confirming that the product code 2 has been marked on the workpiece 1. Therefore, reading the product code 2 with the second sensor 22 in the first check process 13 is a second confirmation, but in the unlikely event that the product code 2 is scratched or stained for some reason after the marking process 11, this can be confirmed.

When the second sensor 22 reads the product code 2, the information of the product code 2 is sent from the second sensor 22 to the computer 23, and the product code 2 is registered and stored in the storage device of the computer 23. If the second sensor 22 cannot read the product code 2, the information of the product code 2 is not sent from the second sensor 22 to the computer 23, and the computer 23 determines that an error has occurred and displays that fact on a display screen, for example. The worker visually checks the product code 2 of the work 1, and if the product code 2 is scratched, for example, the work 1 is discarded as a defective product. In addition, if the product code 2 is dirty, the worker removes the dirt and reads the product code 2 again with the second sensor 22. If the product code 2 still cannot be read after several attempts to read it with the second sensor 22, the worker discards the work 1 as a defective product. This completes the first check process 13.

In the above explanation, the base code 4 and the product code 2 are read separately, but the second sensor 22 may read the base code 4 and the product code 2 at the same time, and the base code 4 reading may be judged as OK or NG, and the product code 2 reading may be judged as OK or NG consecutively. For example, if the base code 4 cannot be read but the product code 2 can be read, it may be judged as an OK product, and otherwise it may be judged as an NG product. When judging an item as an NG product, the cases where the base code 4 was read and where the product code 2 could not be read may be displayed separately on the display screen so that the operator can understand the reason why it was judged as an NG product.

<Heat treatment step 14>
The work 1 that has passed the first check step 13 is then heat-treated. The heat treatment may be of various types, such as T6 treatment. For example, the heat treatment is performed at a temperature of 100° C. to 200° C. for several hours. Depending on the temperature and time of the heat treatment, the color of the mark 5 changes from FIG. 3(a) to FIG. 3(b). For example, the color of the mark 5 becomes lighter, and as an example, the color of the mark 5 is blue before the change and becomes light blue after the change. Once the color of the mark 5 changes, it does not return to its original color even if the temperature of the work 1 returns to the original temperature before the heat treatment, such as room temperature. Even if the color of the mark 5 changes, the base code 4 is covered by the mark 5, and the base code 4 cannot be read by a code reader (sensor).

<Second check step 15>
The second check step 15 is a step of checking the color of the mark 5 of the workpiece 1 after the heat treatment. The color of the mark 5 can be checked, for example, visually. The color of the mark 5 may be automatically checked, for example, by image processing. By visually checking the color of the mark 5, the worker can easily determine whether the workpiece 1 has been heat-treated or not. If the color of the mark 5 is the color after the change, the workpiece 1 has been heat-treated. On the other hand, if the color of the mark 5 remains the same as before the change, the workpiece 1 has not been heat-treated. By looking at the color of the mark 5, it is possible to easily determine whether the workpiece 1 has been heat-treated or not.

As described above, the mark 5 for determining whether or not the workpiece 1 has been heat-treated is provided on the workpiece 1, so that it is easy to determine whether or not the workpiece 1 has been heat-treated by using the mark 5. For example, even if a workpiece 1 that has not been heat-treated is mixed in with a group of workpieces 1 that have been heat-treated, the workpiece 1 that has not been heat-treated can be easily found.

In addition, since the color of the mark 5 changes irreversibly depending on whether or not heat treatment has been performed, it is possible to confirm that the mark 5 has been applied before heat treatment, and also to confirm that the mark 5 has been applied after heat treatment. If the color of the mark 5 were transparent before and after heat treatment, it would be difficult to see the presence of the mark 5 and to determine whether or not the mark 5 had been left on. However, since the presence of the mark 5 can be confirmed before and after heat treatment, forgetting to apply the mark 5 is reliably prevented. Furthermore, the presence or absence of heat treatment can be easily determined by the simple indicator of the change in color of the mark 5. Furthermore, the presence of the mark 5 whose color has changed on the workpiece 1 after heat treatment makes it easy to know that the workpiece 1 has been heat treated by the presence of the mark 5.

Furthermore, since the mark 5 is applied on the base code 4, it is possible to easily and reliably check whether the mark 5 has been applied depending on whether the base code 4 has been read. Moreover, since it is determined that the mark 5 has been applied correctly when the base code 4 cannot be read, it is possible to check in a short time. In particular, if the base code 4 is a quick response code, even if the mark 5 covers a small area of the base code 4, the base code 4 cannot be read, so the work of applying the mark 5 on the base code 4 becomes easier. In addition, even when marking is performed automatically, the application of the mark 5 is reduced. Furthermore, after heat treatment, the presence of the base code 4 and the mark 5 remaining on it can indicate that the work 1 has undergone a regular heat treatment process. The presence of the base code 4 and the mark 5 on it can be easily and visually confirmed, thereby instantly confirming that the work 1 has been heat treated properly. In particular, since the base code 4 and the mark 5 are arranged next to the product code 2 and the product symbol 3, there is no need to search for the base code 4 and the mark 5, and the presence of the base code 4 and the mark 5 can be easily and reliably noticed when checking the product code 2 and the product symbol 3. In this way, the traceability of work 1 is ensured.

1. Work 2. Product code (product identifier)
3. Product code (product identifier)
4. Base code (base identifier)
5 Mark 10 Casting process 11 Stamping process (identifier assignment process)
12 Marking step 13 First check step 14 Heat treatment step 15 Second check step 20 Marking device 21 First sensor 22 Second sensor 23 Computer 30 Marker

Claims (4)

A method for pre-treating a metal workpiece, comprising the steps of:
an identifier assignment step of assigning a base identifier to the work before heat treatment;
A marking step of applying a mark on the base identifier, the color of which is irreversibly changed by heat treatment;
A checking step of checking by a sensor whether or not a mark is correctly placed on the base identifier,
A pretreatment method for a metal workpiece, in which, in a checking step, when a sensor cannot read a base identifier, it is determined that the mark is applied correctly, and when the sensor can read the base identifier, it is determined that the mark is applied incorrectly. 2. The method for pretreating a metallic workpiece according to claim 1 , wherein in the identifier providing step, a product identifier is further provided to the workpiece in addition to the base identifier. A workpiece before heat treatment,
A mark whose color changes irreversibly by heat treatment and a base identifier for checking by a sensor whether the mark is attached normally or not,
The mark is provided on the base identifier and covers at least a portion of the base identifier so that the sensor cannot read the base identifier . The metallic workpiece according to claim 3 , further comprising a product identifier separate from the base identifier .

Images