JP7597993B2 - How to clean vulcanization molds - Google Patents

Description

The present invention relates to a method for cleaning a vulcanization mold, and more particularly to a method for cleaning a vulcanization mold that can efficiently clean a target area while avoiding uneven cleaning in the target area.

When vulcanizing rubber products such as tires, small amounts of dirt from the rubber components and compounding agents adhere to the molding surface of the vulcanizing mold used to manufacture the product. This dirt gradually accumulates with repeated use of the mold, and if the dirt is left as is, it will have a negative effect on the quality of the product being vulcanized. Therefore, it is necessary to clean the molding surface from time to time to remove the dirt. Known methods for cleaning molds include shot blast cleaning, plasma cleaning, and laser light cleaning.

Compared to other cleaning methods, the laser cleaning method is advantageous for efficiently cleaning the area being cleaned while avoiding damage to the area being cleaned. One proposed laser cleaning method involves successively detecting the temperature of the surface being irradiated with the laser light, and interrupting the irradiation of the laser light when the detected temperature exceeds a preset allowable temperature (see Patent Document 1). This makes it possible to avoid melting (damage) of the area being cleaned on the mold. However, the cleaning process is stopped while the irradiation of the laser light is interrupted.

However, various studies by the inventors of the present invention have revealed that differences in temperature occur in the irradiated area when the laser light is irradiated due to the specifications of the target area of the mold. Dirt adhering to the target area is removed by being heated by the irradiation of the laser light and vaporizing (sublimating). Therefore, differences in temperature in the irradiated area when the laser light is irradiated cause variations in the degree of cleaning. Therefore, there is room for improvement in efficiently cleaning the target area irradiated with the laser light while avoiding uneven cleaning.

JP 2015-214076 A

An object of the present invention is to provide a method for cleaning a vulcanization mold, which can efficiently clean a target area while avoiding uneven cleaning of the target area.

In order to achieve the above object, the method for cleaning a vulcanizing mold of the present invention removes dirt adhering to a target area on a molding surface of the vulcanizing mold by irradiating the target area with laser light while moving the vulcanizing mold and a laser head that irradiates the laser light relative to each other, the method comprising the steps of: moving the laser head relative to the molding surface while setting three parameters, namely, the distance between the laser head and the irradiation area of the target area irradiated with the laser light, the speed of the relative movement between the vulcanizing mold and the laser head, and the output of the laser light, under predetermined conditions for each specification of the molding surface; detecting the temperature of the irradiation area in the target area when the laser light is irradiated by a temperature sensor while moving the laser head relative to the molding surface; The cleaning step includes a temperature grasping step for grasping in advance the temperature distribution of the target area when the laser light is irradiated, and grasping the variation in heating temperature due to the difference between the parts of the target area that are easily irradiated and the parts that are not easily irradiated by the laser light from the temperature distribution. The cleaning step includes cleaning a vulcanization mold having a target area with the same specifications as the target area whose temperature distribution has been grasped in the temperature grasping step, and performing a control operation for adjusting at least one of the three parameters based on the temperature distribution and an allowable temperature range that is preset for the target area , so that cleaning is performed so that the temperature of the irradiation area when the laser light is irradiated to the target area is maintained within the allowable temperature range.

According to the present invention, when cleaning a vulcanization mold having a target area with the same specifications as the target area for which the temperature distribution has been determined, using the previously determined temperature distribution, the control operation adjusts one of three parameters, the distance between the laser head and the irradiation area of the target area, the speed of the relative movement between the vulcanization mold and the laser head, and the output of the laser light, so that the temperature of the irradiation area when the laser light is irradiated is maintained within the allowable temperature range. The degree of removal of dirt adhering to the target area depends largely on the temperature of the irradiation area when the laser light is irradiated. Therefore, by performing the control operation, it is possible to efficiently clean the target area while avoiding uneven cleaning.

FIG. 2 is an explanatory diagram illustrating an example of a form of a vulcanization mold cleaning device used in the present invention in a plan view. FIG. 2 is an explanatory diagram illustrating a molding surface of a mold for vulcanizing a studless tire in a plan view. FIG. 2 is an explanatory diagram illustrating an enlarged cross-sectional view of a molding surface of the intercast mold. FIG. 13 is an explanatory diagram illustrating a state in which the mold is being cleaned as viewed from the side. FIG. 13 is an explanatory diagram illustrating a state in which the mold is being cleaned as viewed from the front. 1 is an explanatory diagram illustrating a molding surface (target area) of a mold divided into multiple sections in a plan view to show temperature distribution. FIG. 4 is an explanatory diagram illustrating an enlarged example of a tip portion of a laser head emitting laser light; FIG. 11 is an explanatory diagram illustrating a state in which a mold arranged inside the cover is being cleaned as viewed from the front; FIG. 13 is an explanatory view illustrating, in cross section, a state in which a mold is being cleaned by another embodiment of the cleaning device. FIG. 10 is an explanatory diagram illustrating the inside of the case of FIG. 9 in a plan view. FIG.

The method for cleaning a vulcanization mold of the present invention will be described based on the embodiment shown in the drawings. In the following description, a tire vulcanization mold is the object of cleaning, but the present invention can be used for cleaning any vulcanization mold for vulcanizing rubber products, not limited to tires.

1, a vulcanization mold cleaning device 1 used in the present invention removes dirt X adhering to a target area to be cleaned of a tire vulcanization mold 11 (hereinafter referred to as mold 11) by using laser light L. The sectional type mold 11 is composed of a plurality of sector molds 11A assembled into a cylindrical shape and two annular side molds, as described below.

This cleaning device 1 includes a laser oscillator 2, a laser head 3, and a moving means for moving the mold 11 and the laser head 3 relative to one another. The laser oscillator 2 and the laser head 3 are connected by an optical fiber cable 2a. This cleaning device 1 further includes a temperature sensor 7 and a control unit 6 to which data detected by the temperature sensor 7 is input. The control unit 6 is a computer equipped with a calculation unit and a storage unit. A monitor 10 is connected to the control unit 6. The monitor 10 displays various data stored in the control unit 6 and the results of calculations performed by the control unit 6.

The temperature sensor 7 detects the temperature t of the irradiation range in the target area when the laser light L is irradiated. In this embodiment, the temperature sensor 7a (mobile temperature sensor 7a) is attached to the laser head 3, and the temperature sensor 7b (fixed temperature sensor 7b) is fixed to a predetermined position above the molding surface 12 of the mold 11. It is sufficient to have at least one of the two temperature sensors 7a, 7b. The temperature sensor 7 is preferably a non-contact type that detects the temperature without contacting the detection target, and for example, a thermography device can be used.

The laser head 3 is detachably attached to the tip of the arm 5, which is composed of multiple arm sections 5a, 5b rotatably connected. The arm 5 is rotatably attached to the arm base 4, and the temperature sensor 7a is attached to the laser head 3. The movement of the arm 5 and the laser head 3 is controlled by the control unit 6. The position of the laser head 3 is sequentially input and stored in the control unit 6, and shape data of the molding surface 12 and position data of the mold 11 (molding surface 12) are also stored in the control unit 6.

By controlling the movement of the arm 5, the laser head 3 can be moved to a desired position in three dimensions, and the temperature sensor 7a can always be directed toward the irradiation range of the laser light L. Therefore, the arm 5 functions as a moving means for moving the mold 11 and the laser head 3 relative to each other.

The laser light L supplied by the laser oscillator 2 is sent to the laser head 3 through the optical fiber cable 2a. The laser light L is irradiated from the laser head 3 to the molding surface 12, which is the target area of the mold 11.

The laser light L may be any laser light L that has been conventionally used for cleaning the mold 11. Specific specifications of the irradiated laser light L are, for example, as follows. The type of laser light L is not particularly specified, but Yb-YAG laser light (wavelength 1030 nm) and Nd-YAG laser light (wavelength 1064 nm) are preferable. The light source output of the laser light L is 1 W to 5 kW, the pulse width is 1 ns to 500 ns, the pulse energy is 1 mJ to 0.1 J, the pulse frequency is 1 kHz to 100 kHz, the fluence is 0.5 J/m ² to 4.0 J/m ² , the beam diameter is 0.1 mm to 3 mm, the pulse overlap is 0 to 100%, and the line overlap is 0 to 100%.

In this embodiment, a laser head 3 is provided that irradiates the laser light L at a pinpoint, but the laser head 3 is not limited to this type. For example, a laser head 3 that has a built-in galvanometer mirror and can scan the laser light L in the width direction to irradiate a wide area can also be used. The laser head 3 is not limited to one, and can be designed to have multiple laser heads 3. It is also possible to have multiple laser heads 3 of the same type, or to have a combination of different types of laser heads 3.

The mold 11 to be cleaned is not limited to a sectional type, and may be a two-piece type. Also, it is not limited to a mold for general tires, and may be a mold for vulcanizing studless tires as shown in Figure 2. The molding surface 12 of the mold 11 in Figure 2 has protruding groove forming projections 13 and sipe forming projections 14. The groove forming projections 13 are cast integrally with the base material of the mold 11, and the sipe forming projections 14 are attached to the molding surface 12 as separate bodies from the base material of the mold 11. The base material of the mold 11 is mainly made of aluminum, and the sipe forming projections 14 are made of steel, etc. Therefore, this molding surface 12 is made of a plurality of materials with different melting points.

The thickness of the sipe forming projections 14 is approximately 0.4 mm to 1.2 mm. As such, the sipe forming projections 14 are thinner than other parts and therefore more susceptible to heating, making them at a relatively high risk of melting when irradiated with laser light L. In addition, the surfaces and bases of the sipe forming projections 14 and the thin groove forming projections 13 are areas where it is difficult to remove dirt X when cleaning the mold 11. Note that the C, R, and W arrows in the figure indicate the circumferential, radial, and width directions, respectively, of the tire that is inserted into the mold 11 and vulcanized.

Another example of a mold 11 to be cleaned is a joint mold for vulcanizing pneumatic tires, as shown in FIG. 3. This mold 11 is manufactured by casting the first casting portion 15 and then casting the second casting portion 16, which is called joint casting. A minute gap g is formed in the joint portion 18 between the first casting portion 15 and the second casting portion 16 due to solidification and shrinkage of the molten metal that is poured. The size of this minute gap g is, for example, 5 μm to 80 μm. An exhaust hole 17 is formed in communication with the minute gap g. In this mold 11, unnecessary air and gas during tire vulcanization are discharged from the molding surface 12 through the minute gap g to the exhaust hole 17, and are discharged to the outside of the mold 11 through the exhaust hole 17. This minute gap g is an area where it is difficult to remove dirt X when cleaning the mold 11.

As shown in the examples of Figures 4 and 5, when removing dirt X, the laser head 3 is moved relative to the molding surface 12 while irradiating the molding surface 12 with laser light L. If the direction of irradiation of the laser light L is set to a direction slightly inclined (approximately 20° to 30°) from the normal direction to the molding surface 12 rather than normal to the molding surface 12, it becomes easier to irradiate the laser light L at a specific position with high precision.

Next, a method for cleaning the mold 11 will be described using an example of cleaning the sector mold 11A. To clean the mold 11, first, a temperature determination process is carried out. Then, the cleaning process is carried out using the temperature distribution TD determined in the temperature determination process.

In the temperature determination process, the temperature t of the irradiated area on the molding surface 12 when the laser light L is irradiated is detected by the temperature sensor 7. This allows the temperature distribution TD of the target area, the molding surface 12, when irradiated with the laser light to be determined in advance.

Therefore, with three parameters set as predetermined conditions - the distance d between the laser head 3 and the irradiation area of the molding surface 12, the speed of relative movement between the mold 11 and the laser head 3, and the output of the laser light L - the temperature t of the irradiation area when the molding surface 12 is irradiated with the laser light L while the laser head 3 is moved relative to the molding surface 12 is detected in advance by the temperature sensor 7. The detection data of the temperature sensor 7 is input and stored in the control unit 6. Temperature distribution TD data is created by the control unit 6 based on the input and stored detection data of the temperature sensor 7.

As shown in FIG. 6, this temperature distribution TD is obtained by dividing the molding surface 12 into multiple sections (A1-A8, B1-B8, C1-C8, D1-D8, E1-E8, F1-F8, G1-G8, H1-H8), and the maximum temperature detected by the temperature sensor 7 in each section is stored. Each section is colored according to its maximum temperature, creating a color-mapped temperature distribution TD. This temperature distribution TD makes it possible to determine which parts are sufficiently irradiated with the laser light L (parts that are easily irradiated) and which parts are not sufficiently irradiated with the laser light L (parts that are difficult to irradiate).

In this embodiment, the molding surface 12 of one sector mold 11A is divided into eight sections in both the width direction and the circumferential direction, but the number of sections can be set appropriately depending on the shape and material of the molding surface 12. Since there are many molds 11 having molding surfaces 12 with different specifications (shapes, materials, etc.), data on the temperature distribution TD is grasped and stored for each specification of the molding surface 12.

In addition, an allowable temperature range AT during cleaning is preset for each specification of the molding surface 12 and stored in the control unit 6. This allowable temperature range AT is set to a temperature range in which the molding surface 12 does not melt even when heated by irradiation with laser light L, and dirt X can be removed. One allowable temperature range AT may be set for one molding surface 12, or one molding surface 12 may be divided into multiple sections and a separate allowable temperature range AT may be set for each section. For example, an allowable temperature range AT may be set for each section shown in Figure 6.

This temperature grasping process can be carried out, for example, when cleaning the molding surface 12 of any mold 11 having dirt X adhering to the molding surface 12. Specifically, the speed of relative movement between the mold 11 and the laser head 3 is set to a predetermined constant value, the output of the laser light L is set to a predetermined constant value, and the molding surface 12 is irradiated with the laser light L while the laser head 3 is moved along the molding surface 12 so as to maintain the separation distance d between the laser head 3 and the irradiation range of the molding surface 12 at a predetermined constant value, thereby cleaning the molding surface 12. While this cleaning is being performed, the temperature t of the irradiation range on the molding surface 12 when the laser light L is irradiated is detected by the temperature sensor 7. The temperature distribution TD created based on this detection data is set as the temperature distribution TD to be used initially.

Alternatively, the temperature determination process can be performed on a brand new, unused mold 11 with no dirt X adhering to the molding surface 12. Then, data on the temperature distribution TD for the brand new molding surface 12 can be determined and stored. This temperature distribution TD can also be set as the temperature distribution TD to be used initially.

Depending on the shape of the molding surface 12, there may be some locations where it is difficult to detect the temperature t using only one temperature sensor 7. In this case, by using two types of temperature sensors 7a and 7b, one can complement the other, making it easier to detect the temperature t so as to cover the entire target area.

The dirt X adhering to the target area is removed by being heated and vaporized (sublimated) by the irradiation of the laser light L, so the degree to which the dirt X is cleaned is largely dependent on the temperature of the molding surface 12 heated by the irradiated laser light L. Therefore, by appropriately setting the temperature of the molding surface 12 in the irradiated range when the laser light L is irradiated, it is possible to more reliably remove the dirt X. On the other hand, if the molding surface 12 in the irradiated range is heated excessively, there is a risk that the molding surface 12 will melt and be damaged.

When the distance d between the laser head 3 and the irradiation area is different, the temperature t of the irradiation area of the molding surface 12 when the laser light L is irradiated also differs, even if other conditions are the same. As illustrated in FIG. 7, the focal distance D (e.g., about 100 mm) at which the laser light L irradiated from the head 3 most effectively heats the irradiation area is very narrow in practical use (e.g., a range of about ±10 mm with respect to the focal distance D). As the distance d approaches the focal distance D, the temperature t of the irradiation area of the molding surface 12 when the laser light L is irradiated increases.

In addition, as the speed of relative movement between the mold 11 and the laser head 3 slows down, the temperature t of the irradiated area of the molding surface 12 when irradiated with the laser light L increases, assuming other conditions are the same. In addition, as the output of the laser light L increases (becomes stronger), the temperature t of the irradiated area of the molding surface 12 when irradiated with the laser light L increases, assuming other conditions are the same.

In the cleaning process, the molding surface 12 is cleaned so that the temperature t of the molding surface 12 in the irradiation range when the laser light L is irradiated is maintained within the allowable temperature range AT based on previously determined data. Specifically, when cleaning a molding surface 12 with the same specifications as the molding surface 12 whose temperature distribution TD described above is determined, a control operation is performed in which at least one of the three parameters of the separation distance d between the laser head 3 and the irradiation range, the speed of the relative movement of the mold 11 and the laser head 3, and the output of the laser light L is adjusted by the control unit 6 based on the determined temperature distribution TD and the allowable temperature range AT for the target area (molding surface 12). The correlation between each parameter and the temperature t of the molding surface 12 in the irradiation range when the laser light L is irradiated is determined by a pre-test or the like. While performing this control operation, the molding surface 12 is cleaned so that the temperature t of the irradiation range when the laser light L is irradiated is maintained within the allowable temperature range AT.

The sector molds 11A are cleaned in a cleaning booth. In this embodiment, the sector molds 11A are cleaned one by one, so one sector mold 11A is placed in a predetermined position as shown in FIG. 1. The laser head 3 is then moved to cover the entire target area as shown in FIG. 4 and FIG. 5, and cleaning is performed while performing the above-mentioned control operation so that the temperature t of the irradiation range when the laser light L is irradiated is maintained within the allowable temperature range AT.

Specific examples of the above-mentioned control operations include setting the speed of relative movement between the mold 11 and the laser head 3 and the output of the laser light L to the same as in the temperature determination process, and changing only the distance d between the laser head 3 and the irradiation range of the molding surface 12 for the temperature determination process, which simplifies control. When suppressing the temperature rise in the irradiation range, whether to make the distance d larger or smaller than the focal length D is determined taking into account the shape of the molding surface 12, the space available for moving the laser head 3, and other factors.

As described above, the cleaning process is performed using the temperature distribution TD previously determined by the temperature determination process, so the temperature t of the irradiation range when the laser light L is irradiated can be maintained within the allowable temperature range AT that can remove the dirt X and does not damage the molding surface 12. Since the degree to which the dirt X adhering to the molding surface 12 is removed is largely dependent on the temperature t of the irradiation range when the laser light L is irradiated, performing the above-mentioned control operation allows efficient cleaning while avoiding the occurrence of uneven cleaning in the target area.

Even if the mold 11 has a molding surface 12 with a complex shape, such as a mold for vulcanizing studless tires or a casting mold for vulcanizing pneumatic tires, this cleaning method can efficiently remove dirt X. As an auxiliary means for maintaining the temperature t of the molding surface 12 within the allowable temperature range AT, a heating means for heating the molding surface 12 (mold 11) or a cooling means for cooling the molding surface 12 can also be provided.

The initially set temperature distribution TD can be used for a predetermined period of time, or until a predetermined number of molds 11 have been cleaned. Alternatively, the temperature distribution TD used can be updated sequentially. For example, at each cleaning process, the temperature t of the irradiated area of the molding surface 12 when the laser light L is irradiated is detected by the temperature sensor 7, the temperature distribution TD of the target area when the laser light is irradiated is grasped, and this grasped temperature distribution TD is used in the next cleaning process. In other words, the temperature grasping process can be carried out in conjunction with the cleaning process.

In addition, the temperature determination process can be performed when the mold 11 is brand new and unused, to determine the temperature distribution TD when the mold is brand new in advance, and the above-mentioned control operation can be performed taking into account the temperature distribution TD when the mold is brand new. For example, if the temperature distribution TD is determined by performing the temperature determination process by cleaning the molding surface 12 on which dirt X has adhered, there is a possibility that extreme local variations in the temperature distribution TD will occur due to the dirt X that has adhered. Therefore, when using such a temperature distribution TD, if there is a temperature difference between the temperature distribution TD when the mold is brand new and the temperature distribution TD when the mold is brand new that exceeds the allowable value, the temperature distribution TD can be corrected by referring to the temperature distribution TD when the mold is brand new. For example, for parts where there is a temperature difference between the two that exceeds the allowable value, the temperature distribution TD when the mold is brand new is used to perform the cleaning process.

In addition, if a comparison process is performed in which a temperature determination process is performed in conjunction with the cleaning process and the determined temperature distribution TD is compared with the temperature distribution TD when the product is new, it becomes possible to determine the distribution of the susceptibility of dirt X to adhesion in the target area. It also becomes possible to determine the change over time in the susceptibility of dirt X to adhesion in the target area.

When carrying out the above-mentioned cleaning process, as illustrated in FIG. 8, the irradiation area of the molding surface 12 irradiated with the laser light L should be always under an atmosphere of inert gas G. That is, the oxygen present in the irradiation area should be replaced with inert gas G to always maintain an extremely low-oxygen state compared to the atmosphere. This can suppress the formation of nano-level ultrafine protrusions on the molding surface 12 due to the irradiation of the laser light L. These ultrafine protrusions cause rubber defects in the vulcanized rubber product by leaving the vulcanized rubber attached when the rubber vulcanized using the mold 11 after irradiation with the laser light L is released. Therefore, according to the embodiment illustrated in FIG. 8, it is effective in avoiding the defect of rubber defects occurring in the vulcanized rubber product. As the inert gas G, nitrogen gas, argon gas, etc. can be used.

In this embodiment, in order to stably maintain the irradiation range under an atmosphere of inert gas G, the molding surface 12 to be cleaned is placed in a space covered by a cover 8, and the internal space of this cover 8 is filled with inert gas G. The laser head 3 is movably placed in the internal space of the cover 8 through an opening 9a formed in the upper surface of the cover 8. This embodiment can also be used in the temperature determination process.

In another embodiment of the cleaning device 1 shown in Figures 9 and 10, a plurality of sector molds 11A are cleaned at once in the above-mentioned cleaning step. That is, the number of sector molds 11A required for vulcanizing one green tire are arranged in a ring shape with their molding surfaces 12 on the inside. Each mold 11 is placed on a receiving stand 9b. Each sector mold 11A is covered by a cover 8 having an opening 9a on its upper surface, and the molding surface 12 is arranged in the internal space of the cover 8.

The arm 5, which can move up and down, passes through the opening 9a and extends up and down at the annular center of the sector mold 11A arranged in a ring. The laser head 3 is attached to the tip of the arm 5. The arm 5 is rotatable around its vertical axis, and the laser head 3 rotates together with the arm 5. This laser head 3 can be swiveled up and down. Instead of a structure in which the arm 5 rotates around its vertical axis, a structure in which the receiving base 9b rotates around the vertical axis of the arm 5 can also be used. In this way, the receiving base 9b can function as part of a moving means for moving the mold 11 and the laser head 3 relative to each other.

When cleaning the molding surface 12 of each sector mold 11A, the arm 5 is rotated while irradiating the laser light L from the laser head 3 arranged inside the cover 8. In addition, the arm 5 is moved up and down and the laser head 3 is swung up and down as appropriate to move the laser head 3 to the required range of the molding surface 12 and perform cleaning with the laser light L. It is advisable to supply an inert gas G to the internal space of the cover 8 to keep the irradiation range of the laser light L in a constant low-oxygen state while cleaning the molding surface 12. This embodiment has the advantage of being able to clean many sector molds 11A at once. This embodiment can also be used in the temperature determination process.

REFERENCE SIGNS LIST 1 Cleaning device 2 Laser oscillator 2a Optical fiber cable 3 Laser head 4 Arm base 5 Arm 5a, 5b Arm section 6 Control section 7 (7a, 7b) Temperature sensor 8 Cover 9a Opening 9b Receiving stand 10 Monitor 11 Vulcanization mold 11A Sector mold 12 Molding surface 13 Groove molding projection 14 Sipe molding projection 15 First casting section 16 Second casting section 17 Exhaust hole 18 Joint casting section L Laser light X Dirt

Claims (4)

A method for cleaning a vulcanization mold used in manufacturing a rubber product, comprising the steps of: moving a vulcanization mold and a laser head that irradiates a laser beam relative to each other, and irradiating a target area of a molding surface of the vulcanization mold with the laser beam to remove dirt adhering to the target area, the method comprising the steps of:
a temperature determining step of detecting the temperature of the irradiation area in the target area when the laser light is irradiated by a temperature sensor while moving the laser head relative to the molding surface under predetermined conditions for each specification of the molding surface, the temperature distribution of the target area when the laser light is irradiated by the laser light is determined in advance before performing a cleaning step, and the temperature distribution of the target area when the laser light is irradiated is determined from the temperature distribution to determine the variation in heating temperature due to the difference between the parts of the target area that are easily irradiated by the laser light and the parts that are not easily irradiated by the laser light irradiation, and a vulcanization mold having a target area with the same specifications as the target area whose temperature distribution was determined in the temperature determining step is cleaned. The method for cleaning a vulcanization mold according to claim 1, wherein at least one of a mobile temperature sensor that moves with the laser head and a fixed temperature sensor that is fixed at a predetermined position is used as the temperature sensor. The method for cleaning a vulcanization mold according to claim 1 or 2, wherein in the cleaning process, the temperature of the irradiation area when the laser light is irradiated is detected by a temperature sensor, the temperature distribution of the target area when the laser light is irradiated is grasped, and the grasped temperature distribution is used in the next cleaning process to successively update the temperature distribution. The method for cleaning a vulcanization mold according to any one of claims 1 to 3, in which the temperature determination process is carried out when the vulcanization mold is a new, unused product, the temperature distribution when the mold is new is determined in advance, and the control operation is carried out taking into account the temperature distribution when the mold is new.

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