JP2004167744A - Mold cleaning method and cleaning device - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To provide a mold cleaning method by which material tailings can be securely removed in a short time without damaging a mold face by a laser beam, while inhibiting generation of deflection of a light axis, and a mold cleaning device. <P>SOLUTION: This device removes a stain by irradiating the mold 12 having a cavity part 28 concavely formed in the surface 26 of the mold 12 with the laser beam. When the cavity part 28 is cleaned, the mold 12 is cleaned by irradiating the wall face of the cavity part 28 with the laser beam using an illuminator 46 through rotating the mold 12 so as to switch the surface of the mold 12 from a perpendicular position to an oblique position with regard to the light axis L of the laser beam. <P>COPYRIGHT: (C)2004,JPO

Description

[0001]
TECHNICAL FIELD OF THE INVENTION
The present invention relates to a mold cleaning method for removing dirt from a mold for molding a polymer material such as rubber or resin.
[0002]
[Prior art]
Conventionally, as a method of removing material residue such as rubber or resin adhered to a mold surface, a method of cleaning the mold with a liquid chemical such as an alkaline solution (chemical cleaning method), or a method of removing abrasive material such as sand from the mold. There is a method of spraying on a surface at high speed (shot blast method).
[0003]
The chemical cleaning method has the advantage that the material residue can be reliably removed without damaging the mold surface.However, since the liquid chemical permeates into the gaps between the components of the mold, it is necessary to disassemble and clean the mold. It requires drying after cleaning, and further requires assembling man-hours, and requires a great amount of cleaning time and man-hours.
[0004]
On the other hand, the shot blast method does not require disassembly of the mold as described above, but has a problem in that the mold surface is shaved by the abrasive, so that the dimensional change and damage of the mold are large.
[0005]
There is also a method in which carbon dioxide gas pellets are sprayed on the mold surface to remove material debris from the mold surface using a difference in heat shrinkage between metal and rubber or resin. If the agent sticks, it cannot be removed. In addition, since the pellets have a certain particle size, there is a problem that it is impossible to cope with fine irregularities on the mold surface.
[0006]
On the other hand, there is a method of removing dirt by irradiating a mold surface with a laser beam (for example, Patent Document 1). In the case of using a laser beam, while preventing damage to the mold surface, the method can be performed in a short time. The material residue attached to the mold surface can be reliably removed.
[0007]
[Patent Document 1] JP-A-9-277272
[Problems to be solved by the invention]
In the method described in Patent Literature 1, in order to clean the cavity portion of the mold, particularly the vertical wall portion, the laser beam is irradiated while oscillating the laser beam irradiator along the wall shape of the cavity portion. I have. However, when the laser light irradiator is swung in this manner, there is a problem that the optical axis of the laser light is blurred by repeated use, which causes cleaning failure.
[0009]
Accordingly, the present invention provides a mold cleaning method and a cleaning method capable of reliably removing material residue in a short time without damaging the mold surface by laser light while suppressing the occurrence of such optical axis blur. It is intended to provide a device.
[0010]
[Means for Solving the Problems]
The mold cleaning method of the present invention is a method of removing dirt by irradiating a laser beam to a mold having a cavity recessed on the mold surface, and when cleaning the cavity. Then, the mold is rotated so that the surface of the mold is inclined from a posture perpendicular to the optical axis of the laser beam, and the wall surface of the cavity is irradiated with the laser beam.
[0011]
The mold cleaning apparatus of the present invention is a mold cleaning apparatus that removes dirt by irradiating a laser beam to a mold having a cavity recessed in the mold surface, and irradiates the laser beam. An irradiator and a rotating unit for rotating the mold are provided. When the cavity is cleaned, the rotating unit is inclined from a posture perpendicular to the optical axis of the laser beam by the rotating unit. The mold is rotated as described above, and the wall surface of the cavity is irradiated with laser light by the irradiator.
[0012]
Since the laser beam is irradiated by rotating the mold in this manner, the cavity portion, especially the vertical wall portion, is irradiated with the laser beam while suppressing the problem of the deviation of the optical axis of the laser beam as in the conventional case. Thus, the dirt can be removed.
[0013]
In the present invention, when rotating the mold, it is preferable to rotate around the intersection of the optical axis of the laser beam and the mold surface. In the case of rotating around the intersection, the irradiation position is not largely shifted with the rotation as compared with the case of rotating around any other position, for example, in a state where irradiation is performed in the cavity portion. In the case of turning around the intersection, the inside of the cavity can be constantly irradiated with the turning.
[0014]
When the mold is rotated in this way, it is preferable that the intersection is set at the center of the cavity in the width direction. In particular, when the cavity has a semicircular cross section, the laser beam is emitted at the center of the cavity. It is preferable that the optical axis is set to be orthogonal to the surface of the mold, and the mold is rotated around the center point as the center of rotation. In this case, the irradiation position of the laser beam can be moved along the wall surface shape of the cavity along with the rotation operation of the mold.
[0015]
In the present invention, the sound pressure level of the sound generated by the irradiation may be measured while irradiating the laser light, and the irradiation may be terminated when the measured sound pressure level falls below a predetermined value. In this case, in detail, the laser light is irradiated to a portion where the sound pressure level exceeds a predetermined value, and the laser beam is irradiated until the sound pressure level becomes equal to or lower than the predetermined value. Is preferably terminated. At that time, the emission of the laser light itself from the irradiator may be stopped. However, usually, the irradiation of the laser light is changed by changing the irradiated part, and the other part is continuously irradiated. In this way, by measuring the sound accompanying the irradiation of the laser light and irradiating the laser light until the sound pressure level falls below a predetermined level, it is possible to detect the timing of dirt removal without visual observation or the like. it can. This utilizes this phenomenon because when a contaminated portion is irradiated with laser light, a popping sound is generated with the removal of the contaminant. In other words, the dirt has been removed when the plosive sound is no longer generated, so by stopping the laser beam irradiation at that point, the laser beam will not be irradiated for an unnecessarily long time and the dirt will not be left behind. Can be.
[0016]
As the laser light, a YAG laser light is preferable because dirt can be effectively removed while preventing damage to a mold. Further, the present invention is particularly preferably applied to a mold for molding a boot for a constant velocity joint of an automobile in which two cylindrical mounting portions are integrally connected by a bellows portion.
[0017]
BEST MODE FOR CARRYING OUT THE INVENTION
Hereinafter, embodiments of the present invention will be described with reference to the drawings.
[0018]
FIG. 1 is a sectional view of a mold cleaning method according to a first embodiment of the present invention, FIG. 2 is a side view of a mold cleaning apparatus 10 used in the embodiment, and FIG. FIG. 4 is a cross-sectional view of the mold 12 in the same embodiment.
[0019]
As shown in FIG. 4, the mold 12 to be cleaned in the present embodiment is a mold for molding a constant velocity joint boot mounted on a constant velocity joint of an automobile. The mold 12 is configured to be double inside and outside, and forms a molding space 16 for molding a boot with the inside mold 14, and the outside mold 18 accommodates the four inside molds 14. It is configured.
[0020]
The inner mold 14 includes an upper mold 14A, a lower mold 14B, and a core mold 14C. By combining these three members, a short-diameter small-diameter mounting portion 1 and an axial direction with respect to the mounting portion 1 are formed. A molding space 16 is formed for molding a boot including a large-diameter mounting portion 2 having a short cylindrical shape and a bellows portion 3 integrally connecting the mounting portions 1 and 2 with a space therebetween. .
[0021]
The outer mold 18 is composed of an upper mold 18A and a lower mold 18B which are similarly vertically divided at the dividing position of the upper mold 14A and the lower mold 14B in the inner mold 14.
[0022]
A molding material injection portion 22 is provided on the upper surface of the mold 12, and a rubber composition or a thermoplastic elastomer, which is a molding material, is formed in the cavity 16 from the injection portion 22 through an injection path 24 provided in the mold 12. A resin composition comprising a resin or the like is injected.
[0023]
As shown in FIG. 2, the mold cleaning apparatus 10 divides the mold 12 into upper and lower parts and keeps the inner mold 14 in the outer mold 18. The surface can be cleaned. Therefore, in the mold 12 to be cleaned, two flat cavities 28 having a semicircular cross section are formed in the width direction on the flat mold surface (upper surface) 26 as a land area.
[0024]
The cleaning device 10 includes a first truck 30 that rotatably supports the mold 12 and a second truck 32 on which the truck 30 is placed. The first carriage 30 is movably arranged by wheels 34 on a rail 33 provided on the upper surface of the second carriage 32, and can be moved in the left-right direction in FIG. it can. The second cart 32 is movably arranged by wheels 37 on a rail 36 provided on the ground, and in a direction orthogonal to the first cart 30 by a cylinder 38 as a driving means, that is, in a paper plane in FIG. Can move in a vertical direction.
[0025]
The first carriage 30 is configured to be able to rotate the mold 12 around two axes corresponding to the respective cavity portions 28. In other words, with respect to the two cavities 28, 28 provided side by side in the width direction, the mold surface 26 is inclined with respect to the respective central axes (centers of the semicircular cross-sections) 28a, 28a. Then, the mold 12 is rotated. The configuration for that purpose is not particularly limited, but in the present embodiment, as shown in FIG. 3, a box 40 accommodating the mold 12 is provided, and the box 40 is While the bearing portion 42 is provided on the wall surface, the first bogie 30 is provided with a horizontal rotation shaft 44 that supports the box body 40 by being fitted to the bearing portion 42 and that rotates around the center shaft 28a. ing. The rotation shaft 44 is provided so as to be able to advance and retreat in the axial direction. Therefore, the rotation shaft 44 is configured to be able to engage with and disengage from the bearing portion 42. As shown in FIG. 2, the rotating shaft 44 is provided on each of the two central shafts 28a, 28a. When one rotating shaft 44 is engaged with the corresponding bearing 42, the other rotating shaft 44 is rotated. The moving shaft 44 is configured to be disengaged, and the mold 12 can be rotated around the one rotating shaft 44.
[0026]
The mold cleaning apparatus 10 further includes an irradiator 46 for irradiating the molding surface of the mold 12 supported by the first carriage 30 with laser light. The irradiator 46 is attached to the lower end of a support rod 52 that extends vertically downward from a horizontal member 50 spanned over a pair of left and right columns 48, 48, and irradiates the laser beam vertically downward. The support rod 52 is provided so as to move up and down by a cylinder 54 as a driving means, whereby the irradiator 46 can move up and down.
[0027]
The irradiator 46 is connected to a laser oscillator (not shown), and irradiates the mold surface with laser light output from the oscillator. Any laser light source can be used without limitation as long as it can remove dirt on the mold 12 such as rubber or resin without processing metal. For example, a TEA-CO ₂ laser, a YAG laser, an excimer laser and the like can be mentioned, and a laser emitting a pulsed laser beam is suitably used. Among them, a YAG laser is particularly preferable. The YAG laser has an advantage of being superior in cleaning property to mold contamination as compared with an excimer laser, has less shaving than a CO ₂ laser, and has an advantage that the apparatus is compact because it is a solid-state laser. In particular, in the case of a mold for molding a constant velocity joint boot as in the present embodiment, the mounting portions 1 and 2 serve as seal portions for sealing the grease-enclosed space inside the boot from the outside. When strict quality is required, constant dimensional quality can be secured for a long period of time by using a YAG laser with less shaving.
[0028]
The mold cleaning device 10 further includes a sound pressure level measuring device that measures a sound pressure level of a sound generated by the irradiation of the laser beam. In the present embodiment, the measurement of the sound pressure level is used by modifying the noise test method of JIS D 1026. That is, a sound level meter conforming to JIS C 1505 is used as a sound pressure level measuring device, and the microphone 56 is attached to the horizontal member 50 near the irradiator 46 as shown in FIG. Then, the microphone 56 is installed facing the mold 12 with the reference axis (free sound field) perpendicular to the ground. The microphone 56 is arranged at a distance of about 50 cm from the irradiation position of the laser light.
[0029]
When cleaning the mold 12 using the mold cleaning apparatus 10, the upper surface of the mold 12 is irradiated with laser light by the irradiator 46 to remove dirt while measuring the sound pressure level with the microphone 56. Go. In particular, when cleaning the cavity 28, the wall surface of the cavity 28 is rotated while rotating the mold 12 such that the mold surface 26 is inclined from a posture perpendicular to the optical axis L of the laser beam. Is irradiated with laser light.
[0030]
More specifically, as shown in FIG. 1A, the mold 12 is moved so that the optical axis L of the laser beam coincides with the center axis 28a of one cavity 28 of the mold 12. As shown in (b) and (c), the mold 12 is rotated about the central axis 28a. Thereby, the laser beam can be applied to the wall surface of the cavity 28 having a semicircular cross section at an angle close to a right angle. The mold 12 is moved in the axial direction of the cavity 28 by operating the second carriage 32 while irradiating the laser beam along the arc-shaped wall shape in this manner, and the cavity 28 is Washing may be performed over the entire length in the direction. When the cleaning of one of the cavity portions 28 is completed in this way, the mold 12 is returned to the horizontal posture as shown in FIG. 1D, and then the first carriage 30 is operated so that the optical axis of the laser light is L is moved so as to coincide with the center axis 28a of the other cavity 28 of the mold 12, and the other cavity 28 is cleaned in the same manner as described above.
[0031]
Further, when cleaning the land area of the mold surface 26, it is preferable to scan the laser beam at the same speed as that of the cavity 28 in the vicinity of the cavity 28, but in the region apart from this vicinity, Scanning faster than is preferred. This is because the area far from the cavity portion 28 is generally hard to be stained, and even if it is dirty, the stain is small. Therefore, even if a laser beam is scanned at a high speed, the stain can be removed. This is because time can be reduced.
[0032]
When the sound pressure level measured by the microphone 56 exceeds a predetermined value while irradiating the laser beam while moving the mold 12 as described above, it is determined that dirt is attached to the part. Then, the movement of the mold 12 is stopped, and irradiation is continued until the sound pressure level becomes equal to or lower than a predetermined value. Then, when the sound pressure level falls below the predetermined value, it is determined that the dirt has been removed, and the movement of the mold 12 is restarted. Such control can be automatically performed using a computer. As an example, when the dirt portion of the mold 12 is irradiated with laser light by the irradiator 46, a popping sound is generated due to the dirt removal, and the sound pressure level measured by the microphone 56 is 60 dB. . Then, when the dirt was removed by the irradiation of the laser beam, the plosive sound disappeared, and the sound pressure level became 30 dB. Therefore, the predetermined value of the sound pressure level may be set to, for example, 40 dB.
[0033]
In the present embodiment described above, since the mold 12 is cleaned using the laser beam, the cleaning can be performed with the inner mold 14 kept in the outer mold 18. In addition, material residue can be removed without damaging the mold surface.
[0034]
Further, since the mold 12 is rotated while the optical axis L of the laser beam is vertical, the vertical and oblique wall surfaces of the cavity portion 28 can be prevented while preventing the optical axis from being blurred even by repeated cleaning for a long time. Thus, the laser beam can be irradiated at an angle as close to a right angle as possible, and the cleaning efficiency can be increased.
[0035]
Further, since the laser light is irradiated while moving the mold 12, the moving distance of the irradiation position of the laser light is small. Therefore, even if the microphone 56 is kept stationary, the distance from the sound source can be kept almost constant. As a result, the measurement error of the sound pressure level can be reduced.
[0036]
FIG. 5 shows a mold cleaning method according to the second embodiment of the present invention. In this embodiment, the mold 60 to be cleaned has a cavity surface 64 having a rectangular cross section formed at two locations in the width direction on the mold surface 62.
[0037]
In this embodiment, when cleaning the cavity 64, first, as shown in FIG. 5A, the mold 60 is slid in the width direction while the mold 60 is horizontal, and the cavity 46 is The bottom surface is washed by irradiating laser light. Next, as shown in FIG. 5B, the mold 60 is rotated so that the mold surface 62 is inclined at a predetermined angle α with respect to the optical axis L of the laser beam, and the mold 60 is inclined with the inclined posture. While sliding in the direction, first, the vertical wall surface of one cavity portion 64 is irradiated with laser light, and then, as shown in FIG. 5C, the vertical wall surface of the other cavity portion 64 is irradiated with laser light for cleaning. After that, as shown in FIG. 5D, the mold 60 is rotated in the opposite direction so that the mold surface 62 is inclined at a predetermined angle β with respect to the optical axis L of the laser beam. First, the other vertical wall surface of the other cavity portion 64 is irradiated with a laser beam while sliding the 60 in the inclined direction, and then, as shown in FIG. The wall is cleaned by irradiating it with laser light.
[0038]
Other operations can be performed in the same manner as in the above-described first embodiment. In this case as well, the mold 60 is rotated and cleaned while keeping the optical axis L of the laser beam vertical, so that long-term repetition is required. The laser beam can be applied to the vertical or oblique wall surface of the cavity 64 at an angle as close to a right angle as possible, while suppressing the optical axis from being blurred even by the cleaning.
[0039]
FIG. 6 shows a modified example of the second embodiment. In this example, the mold 60 is slid in a horizontal direction while the mold 60 is inclined at a predetermined angle α. As described above, the vertical wall surface of the cavity portion 64 is irradiated with laser light by the irradiator 46 while moving the mold 60 so as to be cleaned. In the case of this modified example, after irradiating the laser beam to the vertical wall portion of one cavity portion 64 shown in FIG. May not be able to be irradiated with laser light, and from this point, the sliding movement in the inclined direction in the above-described second embodiment is more advantageous.
[0040]
In the above embodiment, a molding die for boots has been described as an example, but the present invention is not limited to this, and vulcanization molding is performed with rubber bonded to a metal member. The present invention can be applied to not only dies for various anti-vibration devices but also various dies for molding a polymer material such as rubber or resin.
[0041]
【The invention's effect】
According to the present invention, since the mold is cleaned using a laser beam, it can be cleaned without disassembling the mold as in a chemical cleaning method, and without damaging the mold surface. The material residue can be removed, and the adhesive stuck to the mold surface can also be removed. In addition, since the laser beam is irradiated by rotating the mold, the laser beam is irradiated onto the cavity, especially the vertical wall, while suppressing the deviation of the optical axis of the laser light during long-term repeated use. Then, the dirt can be removed.
[Brief description of the drawings]
FIG. 1 is a sectional view showing a mold cleaning method according to a first embodiment of the present invention.
FIG. 2 is a side view of the mold cleaning device in the embodiment.
FIG. 3 is a sectional view of a main part of the mold cleaning apparatus.
FIG. 4 is a sectional view of a mold according to the same embodiment.
FIG. 5 is a cross-sectional view illustrating a mold cleaning method according to a second embodiment.
FIG. 6 is a sectional view showing a modification of the second embodiment.
[Explanation of symbols]
10 mold cleaning devices 12, 60 molds 26, 62 mold surfaces 28, 64 cavity portion 28a central axis 46 of cavity portion irradiator L optical axis of laser beam

Claims (7)

A method for removing dirt by irradiating a laser beam to a mold having a cavity portion recessed in the mold surface,
When cleaning the cavity, the mold is rotated so that the surface of the mold is inclined from a posture perpendicular to the optical axis of the laser light, and the wall surface of the cavity is irradiated with the laser light. A mold cleaning method. 2. The mold cleaning method according to claim 1, wherein the mold is rotated about an intersection between an optical axis of the laser beam and the surface of the mold. 3. The mold cleaning method according to claim 2, wherein the cavity has a semicircular cross section, and the mold is rotated around a center point of the cavity. The sound pressure level of the sound generated by the irradiation is measured while irradiating the laser light, and the irradiation is terminated when the measured sound pressure level falls below a predetermined value. 3. The mold cleaning method according to 1. The mold cleaning method according to any one of claims 1 to 4, wherein the laser light is a YAG laser light. The mold according to any one of claims 1 to 5, wherein the mold is a mold for molding a boot for a constant velocity joint of an automobile, which is integrally connected between two cylindrical mounting portions by a bellows portion. Mold cleaning method. A mold cleaning apparatus that removes dirt by irradiating a laser beam to a mold having a cavity portion recessed in the mold surface,
An irradiator for irradiating laser light, and a rotating unit for rotating the mold,
When cleaning the cavity, the rotating means rotates the mold so that the surface of the mold is inclined from a posture perpendicular to the optical axis of the laser beam, and the irradiator is used to rotate the mold. A mold cleaning device characterized by irradiating a laser beam to a wall surface of the mold.

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