JP2003010967A - Manufacturing method for sound insuration vehicle body part - Google Patents

Abstract

PROBLEM TO BE SOLVED: To appropriately control a welding temperature, and provide a manufacturing method for a vehicle part easy in mounting of a sound insulation material and high in sound insulation. SOLUTION: The sound insuration material 4 before foaming is set to the vehicle part 1, a part thereof is foamed by welding, and a after solidification in a state of enveloping ribs 6, the whole body is heated and foamed.

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a method of manufacturing a sound-insulating vehicle body part to be welded, and a method of manufacturing a vehicle body part which can maintain a proper welding temperature, can easily be equipped with a sound-insulating material and has a high sound-insulating property. Regarding

[0002]

2. Description of the Related Art With the diversification of the structure of body parts, it is sometimes required to weld thin parts having a plate thickness of 1 mm or less. When the body parts are thin or the thermal conductivity of the body parts is high, the heat input during welding dissipates instantly, so at the start of heat input, the current value is better than the current value suitable for welding. Welding is performed at an appropriate temperature by setting a high current value.

[0003]

However, when welding is started at such a high current as described above, the welding is performed at an appropriate temperature at the beginning, but immediately after that, the heat input becomes excessive and the welding is performed. There is a problem in that the amount of heat input cannot be controlled over the entire welded portion due to burn-through or distortion occurring in the portion.

With respect to this problem, from the viewpoint of improving the appearance quality, in order to suppress heat input and realize regular corrugated welding, a technique of periodically repeating alternating pulse current and direct pulse current for welding. Is known (JP-A-1
0-328837), in the case of this technology,
It is necessary to set detailed conditions for the current value, energization time, etc. according to the thermal conductivity of the member to be welded.

When the vehicle body part has a sound insulation material, it is necessary to cover the sound insulation surface without any gap according to the shape of the vehicle body part. However, the body parts have various shapes,
In particular, it is difficult to cover the entire inside of a vehicle body component having a complicated closed cross-section structure by extrusion molding with a sound insulating material. In addition, since the body parts after welding need to go through the dipping process to the chemical conversion tank and the electrodeposition tank, the position of the sound insulation material will be displaced unless it is fixed so that the position of the sound insulation material does not shift even after the dipping process. Therefore, high sound insulation cannot be realized. As described above, in order to maintain high sound insulation of the vehicle body parts, there is a problem that a fine work is required and the work efficiency is low.

The present invention has been made in view of the above problems of the prior art, and provides a method of manufacturing a vehicle body part that appropriately controls the welding temperature, easily mounts a sound insulating material, and has a high sound insulating property. The purpose is to provide.

[0007]

(1) In order to achieve the above object, according to the invention of claim 1, a vehicle body part is manufactured by welding another vehicle body part to a vehicle body part having a sound insulating material. A method for manufacturing a sound-insulating vehicle body part, comprising: setting a foaming sound-insulating material before foaming to the body part; and welding the body part having the sound-insulating material set to another body part. In the present invention, the sound insulating material can exhibit not only a sound insulating function of blocking sound but also a sound insulating function of preventing noise or a vibration insulating function of preventing vibration.

When the body part to be welded has a high thermal conductivity, the heat is diffused (especially at the start of welding), so the welding temperature is usually set to a high value. When welding is started, the heat input will turn over and the heat input will become excessive, causing burn-through and deformation due to overheating. In this invention, the foaming sound insulation material before foaming is set in the vehicle body part, and thereafter, welding with other vehicle body parts is performed.
Part of the heat applied to the body part during welding is absorbed by the sound insulation material before foaming set in the body part and utilized for foaming the sound insulation material, so that the overheated state of the welded part can be avoided.

Thus, in welding of vehicle body parts to each other, it is possible to prevent the welded portion from becoming overheated, and to provide a sound-insulating vehicle body part free from burn-through and distortion.
In addition, since the foamed sound insulation material with low thermal conductivity is in contact with the body parts with high thermal conductivity, it is possible to maintain the temperature without releasing the heat added for welding, so perform welding with the minimum amount of heat. Therefore, it is possible to provide a sound-insulating vehicle body component that consumes less energy during manufacturing.

In the present invention, the sound insulating material that absorbs heat and foams is set on the body parts before foaming, and this absorbs excessive heat during welding and prevents overheating of the welded portion. The sound insulating material may be made of any material as long as it can absorb heat, and the sound insulating performance may be low. In other words, it can be expected that even a slight amount of sound insulation (or sound insulation or vibration insulation) will be exhibited as long as it is a material that is set near the welded part and can absorb heat. Therefore, the sound insulation material in this invention is generally used as a sound insulation material. It is not limited to the materials sold. Further, the foaming in the present invention is not to be interpreted narrowly, and includes all changes in which the specific gravity of the sound insulating material is lowered by the absorbed heat,
The sound insulating material may be generated uniformly or partially in the entire sound insulating material, and may have a high foaming rate or a low foaming rate.

(2) In order to achieve the above object, according to the invention as set forth in claim 2, the vehicle body part has a locking means for locking the sound insulating material in the vicinity of a welded portion of the vehicle body part. Then, there is provided a method of manufacturing a sound insulation body part for heating the welded body part. In this invention, it is preferable that the locking means is a rib member provided on the vehicle body component (claim 3).

In the present invention, locking means for locking the sound insulating material to the vehicle body part or a rib member provided on the vehicle body part is provided near the welded portion, and heating for foaming is performed after welding. did. This locking means or rib member locks and positions the sound insulation material before foaming, and after welding, it is embedded in the sound insulation material near the welded part foamed by the heat of welding to securely engage the sound insulation material. Stop. Further, the ribs, which are mounted at right angles to the flat surface to reinforce the flat plate portion and the thin portion of the vehicle, have a reinforcing function as well as a positioning function and a guiding function when setting the sound insulating material.

As described above, the sound insulating material is easily set on the vehicle body component in a state before foaming, which is smaller than the gap between the vehicle body components, and the locking means or the ribs surely maintains the state and maintains the appropriate position. The entire sound insulation material is heated to foam, and the foamed sound insulation material is locked in place even after foaming.

As a result, the same effect as that of the first aspect of the present invention can be obtained, and the sound insulation material can be locked at an appropriate position of the vehicle body component.
Even in the dipping process to the electrodeposition tank, since the sound insulation material is heated and foamed while maintaining its position, the sound insulation surface or voids of the vehicle body parts are filled with the sound insulation material without any gaps, improving work efficiency and high sound insulation. It is possible to provide a sound insulation body part.

(3) In order to achieve the above object, according to the invention of claim 4, the welding is performed at a temperature at which at least a part of the sound insulating material set in the vehicle body component foams. A method of manufacturing a body part is provided. In the present invention, welding is performed at a temperature at which at least a part of the sound insulation material foams. As a result, the same effect as that of the above-described invention is achieved, and the sound insulation material located near the welded portion is foamed, so that the sound insulation material that foams the locking member also located near the welded portion wraps around and is not foamed. It is possible to provide a sound-insulating vehicle body part capable of locking the entire sound-insulating material including the above-mentioned part at a predetermined position.

(4) In order to achieve the above object, according to the invention of claim 5, there is provided a method of manufacturing a sound-insulating car body part, wherein the sound-insulating material includes two or more kinds of foaming materials having different expansion ratios. To be done. In the present invention, it is preferable that, of the two or more types of foam materials, a foam material having a high expansion ratio is set near the welded portion (claim 6). In the present invention, the sound insulating material is made of two or more kinds of foam materials having different expansion ratios to form a two-stage foam, and preferably the foam material having a high expansion ratio is set near the welded portion. When the sound insulating material foams, it encloses the locking member to lock the sound insulating material. If the expansion ratio is high, the volume of the sound insulation material can be increased with a small amount of heat and the locking member can be wrapped. On the other hand, if the expansion ratio is high, sufficient strength cannot be ensured, so a sound insulation material with a low expansion ratio was also used. As a result, the same sound effects as those of the above invention can be obtained, the strength of the vehicle body parts can be secured, the sound insulating material can be reliably locked, and the work efficiency can be reliably improved. Parts can be provided.

(5) In order to achieve the above object, in the above invention, it is preferable that the vehicle body part is made of a material containing aluminum (claim 7), and the foamable sound insulation material is a foamable epoxy resin. It is preferable to include (Claim 8). As a result, it is possible to provide a sound-insulating car body part having the same operational effect as that of the above-mentioned invention for a car body part made of aluminum that has high thermal conductivity and is subjected to thin plate processing. Further, since the foamed epoxy resin foams at the temperature of the heat treatment performed in the series of the electrodeposition processing of the vehicle body parts, it is not necessary to additionally provide a process or equipment for further foaming the entire sound insulating material partially foamed, It is possible to provide a sound-insulating vehicle body part with high work efficiency.

[0018]

According to the invention described in claim 1, 7 or 8, when welding vehicle body parts to each other, the welded portions are prevented from being overheated and the welding is performed at an appropriate temperature. It is possible to provide a sound-insulating car body part without distortion. In addition, since the foamed sound insulation material with low thermal conductivity is in contact with the body parts with high thermal conductivity, it is possible to maintain the temperature without releasing the heat added for welding, so perform welding with the minimum amount of heat. Therefore, it is possible to provide a sound-insulating vehicle body component that consumes less energy during manufacturing.

According to the invention of claims 2 to 7 or 8,
The same effect as the invention according to claim 1 can be obtained, and the sound insulation material can be locked at an appropriate position of the vehicle body component, and the sound insulation material can be used even in the dipping step to the chemical conversion tank and the electrodeposition tank performed after welding. Since it is heated and foamed while maintaining the position, the sound insulation surface or the voids of the vehicle body part is filled with the sound insulation material without a gap, and it is possible to provide a sound insulation body part having high sound insulation while improving work efficiency.

[0020]

BEST MODE FOR CARRYING OUT THE INVENTION Embodiments of the present invention will be described below with reference to the drawings. FIG. 1 is a diagram for explaining a dash lower 2 which is a sound insulation body part, and FIG. 2 is a diagram showing a welded portion of the dash lower 2 with a front side member 3.
FIG. 4 is a diagram showing a structure of the dash lower 2 according to the first embodiment, FIG. 4 is a diagram explaining a foaming process of the sound insulation material 4 shown in FIG. 1, and FIG. 5 is a dash according to the second embodiment. It is a figure which shows the structure of the lower 2. Regarding the present invention, two embodiments will be described, but the common basic structure will be described in the first embodiment, and the description thereof will be omitted in the second embodiment.

First, the structure of the sound-insulating vehicle body component 2 according to the first embodiment will be described. Body part 2 of this embodiment
Is the dash lower 2 shown in FIG. This dash lower 2 is a strength member that is attached to the bottom of the dash panel that separates the engine room from the driver's seat. It requires sound insulation, soundproofing, and anti-vibration performance to prevent engine noise and vibration from being transmitted to the driver's seat. Thus, the sound insulating material 4 has not only a sound insulating function but also a sound insulating function and a vibration insulating function. This dash
As shown in FIG. 2, the lower 2 is orthogonal to the front side member 3, which is a structure, and is fixed along the opening of the front side member 3 by arc welding. The dash lower 2 is an aluminum extruded material formed by extrusion molding and has a plate thickness of about 1 mm. The plate thickness of the front side member 3 to which the dash lower 2 is welded is about 2 mm to 3 mm.

FIG. 3 shows a dash lower 2 in which the sound insulating material 4 of the first embodiment is set. The dash lower 2 has a bag-like closed cross-section structure, and a sound insulating material 4 containing a foamable epoxy resin having a foaming ratio of about 20 to 30 is set along the inner wall of the closed cross-section structure. A rib 6 having a Y-shaped cross section or a T-shaped cross section is provided inside the dash lower 2 having the closed cross-sectional structure along the extending direction thereof to lock the sound insulating material 4. The shape and arrangement are not particularly limited as long as the sound insulating material 4 can be locked. Also,
In the body member extruded with the wheel axial direction as the extruding direction like the dash lower 2, a rib structure is formed along the extruding direction. When this rib is used as the locking means 6, Alternatively, when the locking means 6 is provided along this rib structure, the sound insulating material 4 can be set along this rib 6 (using the rib 6 as a guide), and as shown in FIG. Body parts 2 with closed cross-section structure
However, the sound insulation 4 can be easily installed. In particular, when the ribs 6 function as locking means, the locking means (ribs) 6 can be formed at the same time in extrusion molding, and it is not necessary to attach the locking means 6 newly. By the way, it is preferable to apply a lubricant such as calcium stearate to the arranged sound insulating material 4. This is because by applying the lubricant, the sound insulating agent 4 slides inside the dash lower 2 when the sound insulating agent 4 is inserted from one direction of the dash lower 2 having a long bag structure, and the setting becomes easy.

The sound insulating material 4 is set on the dash lower 2 to which arc welding is applied. Here, the significance of the sound insulating material 4 in welding will be explained.
Has high thermal conductivity, so that heat easily diffuses (especially at the start of welding), and the welding temperature is set higher than usual. However, when welding is started, the heat input will turn over and the heat input will become excessive, which may cause burn-through or deformation due to overheating. In this embodiment, the sound insulating material 4 before foaming
Absorbs the heat of arc welding by contacting the dash lower 2 which is a thin plate made of aluminum, and prevents the welded part from becoming overheated.

Next, a method of manufacturing the soundproof vehicle body component according to the first embodiment will be described. First, the sound insulating material 4 before foaming is attached to the dash lower 2 formed by the extrusion molding method.
Are placed. When the sound insulating material 4 is set in this manner, arc welding is performed along the arc welded portion 5 at a temperature of 200 ° C to 400 ° C.

FIG. 4 (a) shows a state in which arc welding has been performed, from the extending direction of the dash lower 2. The amount of heat of the arc welding cannot foam all of the foamed epoxy material of the sound insulating material 4, and only a portion (a portion indicated by a thin ink mark in the figure) of the sound insulating material 4 near the arc welded portion 5 foams.
When the sound insulating material 4 is foamed, the ribs 6 provided on the dash lower 2 are buried in the sound insulating material 4, and in that state, the sound insulating material 4 is cooled and hardened and securely locked to the dash lower 2, so that the welding is performed. The sound insulating material 4 will not be displaced or washed out even in the dipping step to the chemical conversion tank or the electrodeposition tank which is performed later. In addition, in the embodiment, the welding is performed by arc welding.
Since it has a bag-like structure, spot welding or laser welding for joining from one direction cannot be performed, and does not mean that the welding means is limited. For vehicle body parts that do not have a bag structure, welding means such as spot welding and laser welding that are commonly used can be used.

Welded dash lower 2 and front
The side member 3 is put into an electrodeposition oven at about 170 ° C. after dipping into the chemical conversion tank and dipping into the electrodeposition tank, and a coating oven treatment is performed.

FIG. 4 (b) shows a state in which the coating oven treatment has been performed, from the extending direction of the dash lower 2. The dash lower 2 after the painting oven treatment is completely foamed in the electrodeposition oven, and the gap of the dash lower 2 is completely filled (without a gap) as shown by the thin ink in the figure, and the dash lower 2 is foamed epoxy without a gap. Since the material (sound insulation material) 4 is filled, high sound insulation is exhibited.

As described above, in this embodiment, the dash is
When welding the lower part 2 and the front side member 3, it is possible to prevent the welded part from becoming overheated, and the sound insulating material 4 set on the dash lower part 2 is locked at an appropriate position and is performed after welding. It is possible to maintain the position of the sound insulation material even in the dipping process to the chemical conversion tank and the electrodeposition tank, and to maintain high sound insulation.

Incidentally, as the sound insulating material 4, there is also known a sound insulating sheet having an adhesive applied to the back surface thereof in order to improve the work efficiency. However, in the above-mentioned closed cross-section structure, the sound insulating sheet is placed inside during work. In addition to further lowering the workability by sticking to the wall surface, the inner wall surface cannot be completely covered with the sound insulation material 4, and the sound insulation performance cannot be maintained. Also,
It is conceivable to insert the sound insulating material 4 having the same cross-sectional shape into a vehicle body part having a closed cross-sectional structure, but the workability is low and high sound insulating performance cannot be expected. Further, it is necessary to fix the foamed epoxy sheet with an adhesive to fill the space formed by the closed cross-section structure with the foamed epoxy, which causes a problem of sticking to the inner wall similarly to the above. Other,
Urethane foam lacks adhesiveness with aluminum, and since it is necessary to perform foaming in a vehicle assembly process at room temperature, the number of processes such as provision of special filling holes increases. With the conventional sound-insulating vehicle body parts, it was not possible to simultaneously improve the workability of setting the sound-insulating material 4 and the sound-insulating performance as in the present embodiment.

Next, a second embodiment will be described. The basic structure and the basic step of setting the unfoamed sound insulating material 4 before welding and foaming a part of it by the heat of arc welding are common to those of the first embodiment. In the second embodiment, the foamed epoxy material which is the sound insulating material 4 is composed of two or more kinds having different foaming ratios to form two-stage foaming, and the highly foamed epoxy material 41 is set in the vicinity of the arc welding portion 5 and arc welding is performed. The low-foam epoxy material 42 was set in the part far from the part 5. The foaming ratio of the highly foamed epoxy material 42 is 20 to 3
0 times is desirable, and the foaming ratio of the low foaming epoxy material 41 is preferably 3 to 5 times from the viewpoint of strength.

FIG. 5 (a) shows the state after welding in the extending direction of the dash lower 2. The heat generated by welding foams the highly foamed epoxy material 42 having a high foaming ratio, and the foamed highly foamed epoxy material 42 wraps the rib 6. The foamed epoxy material is solidified in this state and locks the sound insulating material 4 and the dash lower 2. At this time, the arc weld 5
The low-foaming epoxy material 42 set in the part far from is not foaming.

This low-foam epoxy material is foamed by a coating oven treatment as shown in FIG.
Completely fill the gap. Here, the reason why only the low-foaming epoxy material that easily expands is not used is that the strength cannot be sufficiently secured when the foaming ratio is high, and it is to prevent the buckling due to the external force. The sound insulating material 4 can be secured and the sound insulating material 4 can be reliably locked.

It should be noted that the above-described embodiments are described for facilitating the understanding of the present invention, and not for limiting the present invention. Therefore, each element and each numerical value disclosed in the above embodiment are
It is intended to include all design changes and equivalents within the technical scope of the present invention.

[Brief description of drawings]

FIG. 1 is a diagram illustrating a dash lower that is a sound-insulating vehicle body part.

FIG. 2 is a view showing a welded portion of a dash lower with a front side member.

FIG. 3 is a diagram showing a structure of a dash lower according to the first embodiment.

FIG. 4 is a diagram illustrating a process of foaming the sound insulation material shown in FIG.

FIG. 5 is a diagram showing a structure of a dash lower according to a second embodiment.

[Explanation of symbols]

1 ... Body 2 ... Dash lower (body parts) 3 ... Front side member (other body parts) 4 ... Sound insulation material, foamed epoxy material 41 ... Low foam epoxy material 42 ... Highly foamed epoxy material 5 ... Arc weld 6 ... Locking member, rib

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Claims (8)

[Claims] 1. A method for manufacturing a vehicle body part by welding another vehicle body part to a vehicle body part having a sound insulation material, wherein a foamable sound insulation material before foaming is set on the vehicle body part, and the sound insulation material is set. For manufacturing sound-insulating car body parts by welding the car body parts to other car body parts. 2. The sound-insulating vehicle body according to claim 1, wherein the vehicle body component has locking means for locking the sound insulating material near a welded portion of the vehicle body component, and heats the welded vehicle body component. Manufacturing method of parts. 3. The method for manufacturing a sound insulation body part according to claim 2, wherein the locking means is a rib member provided on the body part. 4. The method for manufacturing a sound insulation body part according to claim 2, wherein the welding is performed at a temperature at which at least a part of the sound insulation material set on the body part foams. 5. The method for manufacturing a sound insulation body part according to claim 2, wherein the sound insulation material includes two or more kinds of foam materials having different expansion ratios. 6. The foam material having a high expansion ratio among the two or more foam materials is set in the vicinity of the welded portion.
A method for manufacturing the described sound-insulating body part. 7. The method for manufacturing a sound-insulating car body part according to claim 1, wherein the car body part is made of a material containing aluminum. 8. The method of manufacturing a sound-insulating vehicle body part according to claim 1, wherein the foamable sound-insulating material contains a foamable epoxy resin.