JP2009172868A - Vibration welding method - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To provide a vibration welding method which allows an accurate determination of a deposition inline in vibration-welding a synthetic resin member having a soft layer with another synthetic resin member. <P>SOLUTION: The vibration welding method includes the first compression step to abut a synthetic resin member 3 having a soft layer 2 against the other synthetic resin member 4 at a welding position 5 to compress the soft layer 2 under a specific pressure, the second compression step to change the pressure on the soft layer 2 to a pressure lower than the specific pressure, and the welding step to apply vibration to the welding position 5 to vibration-weld the welding position 5 while keeping the soft 2 layer under the same pressure as applied in the second compression step. This arrangement allows an accurate in-line determination of the deposition rate. <P>COPYRIGHT: (C)2009,JPO&INPIT

Description

  The present invention relates to a vibration welding method for joining a synthetic resin member having a soft layer to another synthetic resin member by vibration welding.

In general, another synthetic resin member such as an airbag door is joined by vibration welding to a synthetic resin member such as a soft instrument panel having a soft layer, which is an interior part of an automobile.
The soft layer is made of synthetic rubber, urethane, or the like, and the synthetic resin member such as a soft instrument panel is made of polypropylene resin. Other synthetic resin members such as airbag doors are made of polyethylene resin.
A conventional vibration welding method will be described with reference to FIG.
First, as shown in FIG. 3A, the synthetic resin member 3 having the soft layer 2 and another synthetic resin member 4 are brought into contact with each other at a welding location 5. Subsequently, as shown in FIG. 3B, the soft layer 2 is pressurized at a constant pressure (for example, 500 kgf (6.0 kgf / cm ² )). Subsequently, as shown in FIGS. 3C and 3D, vibration to the other synthetic resin member 4 is started while maintaining the pressurized state, and the welded portion 5 is vibration welded. Thereafter, as shown in FIG. 3E, the pressure applied to the soft layer 2 is removed, and the welding operation of the synthetic resin member 3 having the soft layer 2 and the other synthetic resin member 4 is completed.

However, in the conventional vibration welding method, the soft layer 2 is compressed at the time of vibration welding, and at the vibration start time shown in FIG. 3C and the vibration end time shown in FIG. Since the compression amount (crushing amount) of 2 is different, it is impossible to measure the exact welding amount (the height of the polymerized portion between the synthetic resin member 3 and the other synthetic resin member 4) in-line.
That is, in the conventional vibration welding method, the total height A of the synthetic resin member 3 including the soft layer 2 and the other synthetic resin member 4 at the start of vibration shown in FIG. The value (AB) obtained by subtracting the total height B of the synthetic resin member 3 including the soft layer 2 and the other synthetic resin member 4 at the end of the vibration shown in FIG.
However, in this method, the soft layer 2 is slightly compressed at the end of the vibration shown in FIG. 3D, and the compression amount C (approximately 0.3 mm) is included in the welding amount. It was not measured accurately. Moreover, in the in-line, it was impossible to measure the compression amount C of the soft layer 2 at the end of vibration shown in FIG.
In addition, accurate management of the amount of welding is very important for product quality control. Conventionally, quality control of the welding location was performed by vibration time, but in addition to vibration time, the amount of welding was accurately controlled. This makes it possible to perform more reliable quality control.

Patent Document 1 discloses an invention related to a method for fixing a vehicle interior product. In the vehicle interior product securement method, a skin plate is placed on a placement board of a welding apparatus, and When the core material is placed on the skin plate, the horn is pressed against the core material, and the horn is vibrated, the portion where the core horn is pressed vibrates. Thereafter, the core material is melted by the vibration energy, and the contact portion between the core material located on the extension of the horn and the foam layer of the skin plate is melted by frictional heat accompanying vibration. When the core material and the foam layer are melted in an amount necessary for welding, the ultrasonic wave generation source and the vibrator are moved upward by the cylinder mechanism, and the horn is separated from the core material upward. Then, the melted portion is solidified, and the foam layer of the skin material is welded to the surface of the core material.
JP 2006-110950 A

  As described above, in the conventional vibration welding method shown in FIG. 3, the soft layer 2 is compressed during vibration welding, and the vibration start time shown in FIG. 3C and the vibration shown in FIG. Since the amount of compression of the soft layer 2 is different from the end point, an accurate welding amount cannot be measured in-line.

  Further, Patent Document 1 discloses that the core material and the foam layer are melted by an amount necessary for welding, but a means for accurately measuring the melt amount (welding amount) necessary for welding is disclosed. The above-mentioned problem cannot be solved.

  The present invention has been made in view of such a point, and when a synthetic resin member having a soft layer is vibration welded to another synthetic resin member, vibration capable of measuring an accurate welding amount in-line. It aims at providing the welding method.

In order to solve the above problems, the vibration welding method of the present invention is a vibration welding method in which a synthetic resin member having a soft layer is vibration welded to another synthetic resin member, and the synthetic resin member having the soft layer A first compression step in which the other synthetic resin member is brought into contact at a welding location and the soft layer is compressed at a constant pressure; and then, the pressure applied to the soft layer is increased from the constant pressure. A second compression step for converting the pressure into a low pressure, and then, in a state where the soft layer is pressurized at the same pressure as the second compression step, vibration is applied to the welded portion to vibrate the welded portion. And a welding step.
Thereby, when the vibration welding is performed, the soft layer is not compressed as in the prior art, so that an accurate welding amount can be measured in-line.
Various aspects of the vibration welding method of the present invention and their functions will be described in detail in the section of the following aspect of the invention.

(Aspect of the Invention)
In the following, some aspects of the invention that can be claimed in the present application (hereinafter sometimes referred to as “claimable invention”) will be exemplified and described. In addition, each aspect is divided into a term like a claim, it attaches | subjects a number to each term, and is described in the format which quotes another term as needed. This is for the purpose of facilitating the understanding of the claimable invention, and is not intended to limit the combinations of the constituent elements constituting the claimable invention to those described in the following sections. In other words, the claimable invention should be construed in consideration of the description, embodiments, etc. accompanying each section, and as long as the interpretation is followed, there may be embodiments in which other constituent elements are added to the aspects of each section. In addition, an aspect in which the constituent elements are deleted from the aspect of each item can be an aspect of the claimable invention. In each of the following items, each of items (1), (2), and (4) corresponds to each of claims 1 to 3.

(1) In a vibration welding method in which a synthetic resin member having a soft layer is vibration welded to another synthetic resin member, the synthetic resin member having the soft layer and the other synthetic resin member are welded at a welding location. A first compression step for abutting and compressing the soft layer at a constant pressure; and a second compression step for converting pressure applied to the soft layer to a pressure lower than the constant pressure; Next, in a state where the soft layer is pressurized with the same pressure as that of the second compression step, a vibration step is provided that includes applying a vibration to the welding location to vibrate the welding location. Welding method.
Therefore, in the vibration welding method of the item (1), in the first compression step, the synthetic resin member having the soft layer and another synthetic resin member are brought into contact with each other at the welding position, and the soft layer is kept at a constant pressure. Then, in the second compression step, the pressure applied to the soft layer is converted to a pressure lower than the constant pressure, and then in the welding step, the soft pressure is the same as that in the second compression step. In the state where the layer is pressurized, vibration is applied to the welded part to vibrate the welded part, so when the vibration is welded, the soft layer is not compressed as in the prior art. The amount of welding can be measured.
In addition, the vibration welding method of the item (1) is made by effectively utilizing the properties of the soft layer. That is, the soft layer first applies the soft layer at a pressure (β value) higher than the constant pressure (α value) than the rigidity when the soft layer is compressed at a constant pressure (α value). After that, the vibration welding method of (1) is adopted because it has the property that the rigidity becomes larger when the pressure applied to the soft layer is compressed by converting from β value to α value. Then, during vibration welding, the soft layer is not compressed as in the prior art.

(2) The vibration welding method according to (1), wherein the pressurization time in the first compression step is set longer than the pressurization time in the second compression step.
Therefore, in the vibration welding method of (2), since the pressurization time in the first compression step is set longer than the pressurization time in the second compression step, the soft layer is compressed during vibration welding. It can be surely suppressed.

(3) The soft layer has a property that the rigidity when the soft layer is first pressurized at a pressure higher than the constant pressure and then lowered to the constant pressure is larger than the rigidity when compressed at a constant pressure. The vibration welding method according to item (1) or (2), characterized by comprising:
Therefore, in the vibration welding method of item (3), the soft layer is not compressed as in the prior art during vibration welding, and the vibration during vibration welding is less likely to be absorbed by the soft layer, resulting in a weld location. Since the concentration is concentrated, it is possible to measure an accurate amount of welding and to shorten the welding time as compared with the conventional technique.

(4) The synthetic resin member having the soft layer is a soft instrument panel that is an interior part of an automobile, and the other synthetic resin member is an airbag door. (3) The vibration welding method according to any one of (3).
Therefore, the vibration welding method of (4) is particularly effective when the airbag door is vibration welded to a soft instrument panel that is an interior part of an automobile.

  According to the present invention, when a synthetic resin member having a soft layer is vibration welded to another synthetic resin member, it is possible to provide a vibration welding method capable of measuring an accurate welding amount in-line.

Hereinafter, the best mode for carrying out the present invention will be described in detail with reference to FIGS. In addition, the same member as a prior art example is demonstrated using the same code | symbol.
In the vibration welding method according to the embodiment of the present invention, another synthetic resin member 4 such as an airbag door is attached to a synthetic resin member 3 such as a soft instrument panel having a soft layer 2 that is an interior part of an automobile. It is used when joining by vibration welding. In the present embodiment, the soft layer 2 is made of, for example, synthetic rubber, urethane, or the like, and the amount of compression when the soft layer 2 is compressed at a constant pressure (α value). With a pressure (β value) higher than a certain pressure (α value), and then the compression amount when the pressure applied to the soft layer 2 is converted from β value to α value is slightly different. In addition, the rigidity of the latter pressurization mode is higher than that of the former pressurization mode. The synthetic resin member 3 is made of polypropylene resin (PP). The other synthetic resin member 4 is made of polyethylene resin (PE).

  A vibration welding apparatus that embodies this vibration welding method is not shown, but is similar to the existing vibration welding apparatus, and pressurizes the end surface of the soft layer 2 to make a synthetic resin member 3 having the soft layer 2. And a pressure device that pressurizes the welded portion 5 between the other synthetic resin member 4 and a vibration that chucks and vibrates the other synthetic resin member 4 under predetermined vibration conditions to vibrate the welded portion 5. Device.

  In the vibration welding method according to the embodiment of the present invention, the synthetic resin member 3 having the soft layer 2 and another synthetic resin member 4 are brought into contact with each other at the welding location 5 so that the soft layer 2 has a constant pressure. A first compression step for compressing the soft layer 2, a second compression step for converting the pressure applied to the soft layer 2 to a pressure lower than the constant pressure, and then the same pressure as the second compression step. A welding step in which vibration is applied to the welded portion 5 while the soft layer 2 is pressurized.

Specifically, first, in the first compression step, as shown in FIG. 1A, the synthetic resin member 3 having the soft layer 2 and another synthetic resin member 4 are brought into contact with each other at the welding location 5. . Subsequently, as shown in FIG. 1 (b), the end face of the soft layer 2 is pressed and compressed at a constant pressure for a predetermined time while the movement of the other synthetic resin member 4 is regulated by the pressurizing device. . In the present embodiment, the pressure in the first compression step is a predetermined value of 1000 kgf (12.0 kgf / cm ² ) to 600 kgf (7.1 kgf / cm ² ), and the pressurizing time is approximately 3.0 seconds. Set to The pressure in the first compression step does not need to be increased until the soft layer 2 is crushed to the maximum, and may be set larger than the pressure in the welding step.
Next, in a 2nd compression step, as shown in FIG.1 (c), the pressurization to the soft layer 2 is converted into the pressure lower than the fixed pressure in a 1st compression step, and it pressurizes for a predetermined time. In this embodiment, the pressure in the second compression ^{step, 700kgf (8.3kgf / cm 2)} ~300kgf (3.5kgf / cm 2) at a predetermined value, the pressing time approximately 0.5 seconds Set to

Next, in the welding step, as shown in FIGS. 1D and 1E, in the state in which the soft layer 2 is pressurized with the same pressure as in the second compression step, another synthetic resin member 4 is obtained by the vibration device. And the welded portion 5 is vibrated and welded by vibrating for a predetermined time. In the present embodiment, the vibration condition is set to a predetermined value having a frequency of 100 Hz to 200 Hz and a predetermined value having an amplitude of 2 mm to 5 mm. The vibration time is set to about 10 seconds.
By the way, in the welding step, as shown in FIGS. 1D and 1E, the rigidity of the soft layer 2 is the same as that of FIG. Since it is larger than the state of c), the soft layer 2 is not compressed during vibration welding as shown in FIG.
FIG. 2 shows the transition of the compression amount of the soft layer 2 during vibration welding by this vibration welding method. As can be seen from FIG. It can be seen that the amount of compression changes within a range of ± 0.05 mm and is hardly compressed.
Then, as shown in FIG. 1 (f), when the vibration welding is completed, the pressurization to the soft layer 2 is removed, and the synthetic resin member 3 having the soft layer 2 and the other synthetic resin member 4 are welded. The work is complete.

  As a result, since the soft layer 2 is not compressed in the welding step as in the prior art, in-line, the synthetic resin member 3 including the soft layer 2 and the other composite at the vibration start time shown in FIG. Subtracting the total height B of the synthetic resin member 3 including the soft layer 2 and the other synthetic resin members 4 at the end of vibration shown in FIG. 1E from the total height A of the resin member 4 combined. Thus, an accurate welding amount (A-B) can be measured.

As described above, according to the vibration welding method according to the embodiment of the present invention, the first compression step for compressing the soft layer 2 at a constant pressure, and then the pressurization to the soft layer 2 is the constant pressure. A second compression step for converting the pressure to a pressure lower than the pressure of the second pressure step, and then applying vibration to the weld location 5 in a state where the soft layer 2 is pressurized at the same pressure as the second compression step. Since the soft layer 2 is not compressed as in the prior art when performing vibration welding, an accurate welding amount can be measured in-line.
As a result, the quality control of the welded part 5 is conventionally performed only with the vibration time, whereas the quality control of the welded part 5 can be performed based on the vibration time and the welding amount, so the reliability of the quality control of the welded part 5 Improves.

  Further, when this vibration welding method is adopted, the rigidity of the soft layer 2 becomes larger than before when vibration welding is performed, and vibrations to other synthetic resin members 4 are not easily absorbed by the soft layer 2 and are concentrated at the welding location 5. Therefore, the welding time is about 2/3 as compared with the welding time by the conventional vibration welding method, and the production efficiency is greatly improved.

  In addition, the vibration welding method according to the embodiment of the present invention can be applied to vibration welding of automobile interior parts, and also in the case of vibration welding of a resin soft case with an electric product or the case of vibration welding of a food pack. Applicable and applicable to a wide range of fields.

FIG. 1 is a diagram showing stepwise a vibration welding method according to an embodiment of the present invention. FIG. 2 is a diagram showing a transition of the compression amount of the soft layer at the time of vibration welding in the vibration welding method. FIG. 3 is a diagram showing a conventional vibration welding method step by step.

Explanation of symbols

  2 Soft layer, 3 Synthetic resin member, 4 Other synthetic resin member, 5 Welding location

Claims (3)

In a vibration welding method of vibration welding a synthetic resin member having a soft layer to another synthetic resin member,
A first compression step in which the synthetic resin member having the soft layer and the other synthetic resin member are brought into contact with each other at a welding position, and the soft layer is compressed at a constant pressure;
Next, a second compression step for converting the pressure applied to the soft layer into a pressure lower than the constant pressure;
Next, in a state where the soft layer is pressurized at the same pressure as the second compression step, a welding step of applying vibration to the welding location and vibration welding the welding location;
A vibration welding method comprising:   2. The vibration welding method according to claim 1, wherein the pressurization time in the first compression step is set longer than the pressurization time in the second compression step.   The vibration according to claim 1 or 2, wherein the synthetic resin member having the soft layer is a soft instrument panel that is an interior part of an automobile, and the other synthetic resin member is an airbag door. Welding method.

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