JP3890463B2 - Manufacturing method of sound insulation body parts - Google Patents

Description

[0001]
BACKGROUND OF THE INVENTION
The present invention relates to a method for manufacturing a sound-insulating vehicle body part to be welded, and more particularly to a method for manufacturing a vehicle body part that maintains a welding temperature appropriately, is easy to install a sound insulating material, and has high sound insulation properties.
[0002]
[Prior art]
With the diversification of the structure of body parts, it may be required to weld thin parts with a thickness of 1 mm or less. In this way, when the car body parts are thin or the heat conductivity of the car body parts is high, the heat input at the time of welding diffuses instantaneously, so at the start of heat input, it is more than the current value suitable for welding. A high current value is set and welding is performed at an appropriate temperature.
[0003]
[Problems to be solved by the invention]
However, when welding is started at such a high current, the welding is initially performed at an appropriate temperature, but immediately after that, the heat input becomes excessive, and the welded part is melted down and distorted. As a result, the amount of heat input cannot be controlled over the entire welded portion.
[0004]
Regarding this problem, from the viewpoint of improving the appearance quality, a technique is known in which welding is performed by periodically repeating AC pulse current and DC pulse current in order to suppress heat input and realize regular wave-shaped welding. However, in this technique, fine conditions must be set according to the thermal conductivity of the member to be welded with respect to the current value and the energization time.
[0005]
Moreover, when this vehicle body part has a sound insulation material, it is necessary to cover a sound insulation surface without a gap according to the shape of the vehicle body part. However, the shape of the vehicle body part is various, and it is difficult to cover the entire inside of the vehicle body part having a complicated closed cross-sectional structure by extrusion molding with a sound insulating material. Moreover, since the car body parts after welding need to go through a dipping process to the chemical conversion bath and electrodeposition bath, the sound insulating material will be misaligned unless it is fixed so that the position of the sound insulating material does not deviate even after the dipping process. As a result, high sound insulation cannot be realized. As described above, in order to keep the sound insulation of the vehicle body parts high, there is a problem that fine work is required and work efficiency is low.
[0006]
The present invention has been made in view of such problems of the prior art, and provides a method for manufacturing a vehicle body part that can appropriately control the welding temperature and that is easy to install a sound insulating material and has high sound insulating properties. With the goal.
[0007]
[Means for Solving the Problems]
(1) In order to achieve the above object, according to the first aspect of the present invention, there is provided a method of manufacturing a vehicle body part by welding another vehicle body part to a vehicle body part having a sound insulating material. Provided is a method for manufacturing a sound insulation body part that foams at least a part of the sound insulation material by setting a foamable sound insulation material before foaming and welding the vehicle body part on which the sound insulation material is set to another body part Is done. In this invention, the sound insulating material can exhibit a sound insulating function for blocking noise, a sound insulating function for preventing noise, or a vibration preventing function for preventing vibration.
[0008]
If the body parts to be welded have high thermal conductivity, the heat will diffuse (especially at the start of welding), so the welding temperature is usually set high, but welding starts. If this happens, the heat input will turn over and the heat input will become excessive, causing melting and deformation due to overheating. In this invention, the foaming sound insulation material before foaming is set in the vehicle body part, and then welding with other vehicle body parts is performed. Therefore, a part of heat applied to the vehicle body part during welding is set in the vehicle body part. Since it is absorbed by the previous sound insulating material and used for foaming the sound insulating material, an overheated state of the welded portion can be avoided.
[0009]
Thereby, in welding of vehicle body parts, it can prevent that a welding part will be in an overheated state, and can provide the sound-insulating vehicle body part which does not melt and are distorted. In addition, the foaming sound insulation material with low thermal conductivity is in contact with the body parts with high thermal conductivity, and the temperature can be maintained without escaping the heat applied for welding. Therefore, it is possible to provide a sound insulation body part with low energy consumption during manufacturing.
[0010]
In the present invention, the sound insulating material that absorbs heat and foams is set on the vehicle body part before foaming, and this absorbs excessive heat during welding to prevent overheating of the welded portion. Any material that can absorb heat may be used, and the sound insulation performance may be low. In other words, since a sound insulation property (or sound insulation property or vibration insulation property) can be expected to be exhibited even if it is a material that is set near the welded part and can absorb heat, the sound insulation material in this invention is generally used as a sound insulation material. It is not limited to the materials sold. In addition, foaming in the present invention is not interpreted narrowly, and includes all changes in which the specific gravity of the sound insulating material is lowered by absorbed heat, and even if it occurs uniformly throughout the sound insulating material. It may be produced, and the foaming rate may be high or low.
[0011]
(2) In order to achieve the above object, according to the invention described 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, A method of manufacturing a sound-insulating body part that heats a welded body part is provided. In this invention, it is preferable that the locking means is a rib member provided on the vehicle body part.
[0012]
In the present invention, a 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 in the vicinity of the welded portion, and heating for foaming is performed after welding. This locking means or rib member locks and positions the sound insulating material before foaming, and after welding, it is embedded in the sound insulating material near the welded portion foamed by the heat of welding to securely engage the sound insulating material. Stop. Moreover, the rib attached at right angles to the plane in order to reinforce the flat plate part and the thin part of the vehicle fulfills the positioning function and the guide function when setting the sound insulating material together with the reinforcing function.
[0013]
In this way, the sound insulating material is easily set on the vehicle body part in a state before foaming that is smaller than the gap between the vehicle body parts, and the state is securely maintained by the locking means or ribs, and the sound insulating material is maintained in an appropriate position. The whole is heated and foamed, and the foamed sound insulating material is locked in place even after foaming.
[0014]
Thus, the same effect as that of the invention of claim 1 can be obtained, and the sound insulating material can be locked at an appropriate position of the vehicle body part. In the dipping process to the chemical conversion tank and the electrodeposition tank performed after welding. Since the sound insulation material is heated and foamed while maintaining the position of the sound insulation material, the sound insulation surface or gap of the vehicle body part is filled with a sound insulation material without any gap, and the sound insulation body part having high sound insulation performance is improved while improving the work efficiency. Can do.
[0015]
(3) In order to achieve the above object, according to the invention described in claim 4, the welding is performed at a temperature at which at least a part of the sound insulating material set on the vehicle body part is foamed. A manufacturing method is provided.
In the present invention, welding is performed at a temperature at which at least a part of the sound insulating material foams.
As a result, the same effect as the above invention can be obtained, and the sound insulating material located in the vicinity of the welded portion foams, so that the sound insulating material foamed the locking member also located in the vicinity of the welded portion wraps and is not foamed. Thus, it is possible to provide a sound-insulating vehicle body part that can lock the entire sound-insulating material including the part in a predetermined position.
[0016]
(4) In order to achieve the above object, according to the invention described in claim 5, there is provided a method for producing a sound insulating body part, wherein the sound insulating material includes two or more kinds of foam materials having different expansion ratios. In this invention, it is preferable to set a foam material having a high expansion ratio among the two or more kinds of foam materials in the vicinity of the welded portion.
In the present invention, the sound insulating material is composed of two or more kinds of foam materials having different foaming ratios to form two-stage foaming, and preferably a foam material having a high foaming ratio is set in the vicinity of the welded portion. When the sound insulating material is foamed, the sound insulating material is locked by wrapping the locking member. If the expansion ratio is high, the volume of the sound insulating material can be increased with less heat and the locking member can be wrapped. On the other hand, if the foaming ratio is high, the sound insulation material having a low foaming ratio is also used because sufficient strength cannot be secured.
As a result, the sound-insulating vehicle body that achieves the same effects as the above-described invention, can ensure the strength of the vehicle body parts, can securely engage the sound-insulating material, and can reliably improve the working efficiency. Parts can be provided.
[0017]
(5) In order to achieve the above object, in the above invention, the vehicle body part is preferably made of a material containing aluminum (Claim 7), and the foamable sound insulating material contains a foamable epoxy resin. (Claim 8).
As a result, it is possible to provide a sound-insulating vehicle body part that exhibits the same effects as the above-described invention for a vehicle body part that is made of aluminum that has high thermal conductivity and is further processed into a thin plate. In addition, since the foamed epoxy resin foams at the temperature of the heat treatment performed in the series of electrodeposition treatment of the body parts, it is not necessary to newly provide a treatment or equipment for further foaming the entire sound insulation material partially foamed, It is possible to provide a sound-insulating body part with high work efficiency.
[0018]
【The invention's effect】
According to the first, seventh, or eighth aspect of the present invention, since welding is performed at an appropriate temperature while preventing welding parts from being overheated in welding of vehicle body parts, sound insulation without melting or distortion is caused. A vehicle body part can be provided. In addition, the foaming sound insulation material with low thermal conductivity is in contact with the body parts with high thermal conductivity, and the temperature can be maintained without escaping the heat applied for welding. Therefore, it is possible to provide a sound insulation body part with low energy consumption during manufacturing.
[0019]
According to the second to seventh or eighth aspect of the invention, the same effect as the first aspect of the invention can be achieved, and the sound insulating material can be locked at an appropriate position of the vehicle body part, which is performed after welding. In the dipping process to the chemical conversion tank and electrodeposition tank, the sound insulation material is heated and foamed while maintaining the position of the sound insulation material. A highly sound-insulating vehicle body part can be provided.
[0020]
DETAILED DESCRIPTION OF THE INVENTION
Hereinafter, embodiments of the present invention will be described with reference to the drawings.
FIG. 1 is a view for explaining a dashboard 2 which is a sound insulating body part, FIG. 2 is a view showing a welded portion of the dash lower 2 with a front side member 3, and FIG. 3 is a dashboard 2 according to the first embodiment. FIG. 4 is a diagram for explaining the foaming process of the sound insulating material 4 shown in FIG. 1, and FIG. 5 is a diagram showing the structure of the dashboard 2 according to the second embodiment.
Although two embodiments will be described with respect to the present invention, a common basic structure will be described in the first embodiment, and description thereof will be omitted in the second embodiment.
[0021]
First, the configuration of the sound insulating body part 2 according to the first embodiment will be described. The vehicle body part 2 of the present embodiment is the dashboard 2 shown in FIG. This dash lower 2 is a strength member attached to the lower part of the dash panel that partitions the engine room from the driver's seat, and requires sound insulation performance, sound insulation performance, and vibration isolation performance so as not to transmit engine sound and vibration to the driver's seat. The sound insulating material 4 exhibits not only a sound insulating function but also a soundproofing function and a vibrationproofing function. As shown in FIG. 2, the dashboard 2 is orthogonal to the front side member 3, which is a structural body, and is arc-welded to each other along the opening of the front side member 3. The dash drawer 2 is an aluminum extruded material formed by extrusion molding, and the plate thickness is about 1 mm. The thickness of the front side member 3 to which the dashboard 2 is welded is about 2 mm to 3 mm.
[0022]
FIG. 3 shows a dashboard 2 on which the sound insulating material 4 of the first embodiment is set. The dashboard 2 has a bag-like closed cross-sectional structure, and a sound insulating material 4 containing a foamable epoxy resin having an expansion ratio of about 20 to 30 times is set along the inner wall of the closed cross-sectional structure. On the inner side of the dashboard 2 having the closed cross-sectional structure, a rib 6 having a Y-shaped section or a T-shaped section that locks the sound insulating material 4 along the extending direction is provided. This shape and arrangement are not particularly limited as long as the sound insulating material 4 can be locked. Further, in the vehicle body member that has been extruded with the wheel axis direction as the extrusion direction, such as the dashboard 2, a rib structure is formed along the extrusion direction. When the locking means 6 is provided along the rib structure, the sound insulating material 4 can be set along the rib 6 (using the rib 6 as a guide) and extruded as shown in FIG. Even if the vehicle body part 2 has a closed cross-sectional structure in the direction, the sound insulating material 4 can be easily installed. In particular, when the rib 6 functions as the locking means, the locking means (ribs) 6 can be formed at the same time in the extrusion molding, and there is no need to newly attach the locking means 6. Incidentally, 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, when the sound insulating agent 4 is inserted from one direction of the dashboard 2 having a long bag structure, the sound insulating agent 4 slides inside the dashboard 2 and the setting becomes easy.
[0023]
The sound insulating material 4 is set on the dashboard 2 to which arc welding is performed. Here, the significance of the sound insulating material 4 in welding will be explained. Since the aluminum dashboard 2 has high thermal conductivity, heat is diffused. The welding temperature is set higher than usual. However, when welding is started, this time it turns around and the heat input becomes excessive, and there is a risk that the overheating may cause melting or deformation. In this embodiment, since the sound insulating material 4 before foaming contacts the dashboard 2 which is an aluminum thin plate material and absorbs the heat of arc welding, the welded portion is prevented from being overheated.
[0024]
Next, the manufacturing method of the sound insulation vehicle body part which concerns on 1st Embodiment is demonstrated. First, the sound insulating material 4 before foaming is disposed on the dashboard 2 formed by the extrusion molding method. When the sound insulating material 4 is set in this way, arc welding is performed at a temperature of 200 ° C. to 400 ° C. along the arc welded portion 5.
[0025]
FIG. 4A shows a state where arc welding is performed from the direction in which the dashboard 2 extends. With the amount of heat of arc welding, the entire foamed epoxy material of the sound insulating material 4 cannot be foamed, and only a portion (a portion indicated by light ink in the drawing) near the arc welded portion 5 of the sound insulating material 4 is foamed. When the sound insulating material 4 is foamed, the ribs 6 provided in the dashboard 2 are buried in the sound insulating material 4, and in this state, the sound insulating material 4 is cooled and hardened, and is securely locked to the dashboard 2. Even in the dipping process to the chemical conversion tank and electrodeposition tank to be performed later, the sound insulating material 4 is not displaced or lost. In the embodiment, the welding is performed by arc welding. However, since the dashboard 2 has a bag-like structure, spot welding and laser welding that are joined from one direction cannot be performed. Absent. For vehicle body parts that do not have a bag structure, commonly used welding means such as spot welding and laser welding can be used.
[0026]
The welded drawer 2 and front side member 3 are put into an electrodeposition oven at about 170 ° C. after being dipped into a chemical conversion tank and dipped into an electrodeposition tank, and subjected to a coating oven treatment.
[0027]
FIG. 4B shows a state where the coating oven treatment is performed from the extending direction of the dashboard 2. The dash lower 2 after the coating oven treatment is completely foamed in the electrodeposition oven, and the dash lower 2 is completely filled (without a gap) as shown by the thin ink in the figure. Since the material (sound insulation material) 4 is filled, high sound insulation is exhibited.
[0028]
As described above, in the present embodiment, in welding the dash lower 2 and the front side member 3, the welded portion can be prevented from being overheated, and the sound insulating material 4 set on the dash lower 2 can be appropriately disposed. The position of the sound insulating material can be maintained even in the dipping process to the chemical conversion tank and the electrodeposition tank performed after welding, and high sound insulation can be maintained.
[0029]
Incidentally, as the sound insulating material 4, there is also known a sound insulating sheet in which an adhesive is applied to the back surface in order to improve work efficiency. In the above-described closed cross-sectional structure, the sound insulating sheet is attached to the inner wall surface during the work. Further, the workability is further lowered and the inner wall surface cannot be completely covered with the sound insulating material 4, and the sound insulating performance cannot be maintained. In addition, it is conceivable to insert a sound insulating material 4 having the same shape as the cross-sectional shape of a vehicle body part having a closed cross-sectional structure, but the workability is low and high sound insulating performance cannot be expected. Furthermore, it is necessary to fix the foamed epoxy sheet with an adhesive in order to fill the space formed by the closed epoxy structure with the foamed epoxy, and there arises a problem that it adheres to the inner wall as described above. In addition, urethane foam lacks adhesiveness with aluminum, and foaming needs to be performed in a vehicle assembly process at room temperature, so that a special process such as providing a filling hole increases. In the conventional sound insulation body parts, it is impossible to simultaneously improve the workability of the set of the sound insulation material 4 and the sound insulation performance as in the present embodiment.
[0030]
Next, a second embodiment will be described. The basic structure and the basic process of setting the unfoamed sound insulating material 4 before welding and partially foaming by the heat of arc welding are common to the first embodiment.
In this second embodiment, the foamed epoxy material that is the sound insulating material 4 is composed of two or more types having different foaming ratios to form two-stage foaming, and a high-foamed epoxy material 41 is set in the vicinity of the arc welded portion 5 to perform arc welding. A low-foaming epoxy material 42 was set in a portion far from the portion 5. The expansion ratio of the high-foaming epoxy material 42 is desirably 20 to 30 times, and the expansion ratio of the low-foaming epoxy material 41 is desirably 3 to 5 times from the viewpoint of strength.
[0031]
FIG. 5A shows the state after welding from the extending direction of the dashboard 2. Heat generated by welding causes the high-foaming epoxy material 42 having a high foaming ratio to foam, and the foamed high-foaming epoxy material 42 wraps around the rib 6. The foamed epoxy material is solidified in this state and locks the sound insulating material 4 and the dashboard 2. At this time, the low-foaming epoxy material 42 set in a portion far from the arc welded portion 5 is not foamed.
[0032]
This low-foaming epoxy material is foamed by a coating oven treatment as shown in FIG. 5B, and completely fills the gaps in the dashboard 2. Here, the reason why only the low-foaming epoxy material that easily expands was not used is that the strength cannot be sufficiently secured when the foaming ratio is high, and the buckling due to external force is prevented. The sound insulating material 4 can be reliably locked.
[0033]
The embodiments described above are described for facilitating the understanding of the present invention, and are not described for limiting the present invention. Therefore, each element and each numerical value disclosed in the above embodiments are intended to include all design changes and equivalents belonging to the technical scope of the present invention.
[Brief description of the drawings]
FIG. 1 is a diagram for explaining a dashboard which is a sound-insulating vehicle body part.
FIG. 2 is a view showing a welded portion with a front side member of a dash lower.
FIG. 3 is a diagram showing a structure of a dashboard according to the first embodiment.
4 is a diagram for explaining a foaming process of the sound insulating material shown in FIG. 1; FIG.
FIG. 5 is a diagram showing a structure of a dashboard according to a second embodiment.
[Explanation of symbols]
1 ... body 2 ... dash lower (body parts)
3. Front side member (other body parts)
4 ... Sound insulating material, foamed epoxy material 41 ... Low foamed epoxy material 42 ... Highly foamed epoxy material 5 ... Arc welded portion 6 ... Locking member, rib

Claims (8)

A method of manufacturing a vehicle body part by welding another vehicle body part to a vehicle body part having a sound insulating material,
Set foaming sound insulation before foaming on the body parts,
A method of manufacturing a sound insulating body part , wherein at least a part of the sound insulating material is foamed by welding the vehicle body part on which the sound insulating material is set to another body part. The vehicle body part has locking means for locking the sound insulating material in the vicinity of the welded part of the vehicle body part,
The method for manufacturing a sound-insulating body part according to claim 1, wherein the welded body part is heated. The method of manufacturing a sound-insulating vehicle body part according to claim 2, wherein the locking means is a rib member provided on the vehicle body part. The method for manufacturing a sound insulating body part according to claim 2 or 3, wherein the welding is performed at a temperature at which at least a part of the sound insulating material set on the body part foams. The method for manufacturing a sound insulating body part according to claim 2, wherein the sound insulating material includes two or more kinds of foam materials having different expansion ratios. The method for manufacturing a sound-insulating vehicle body part according to claim 5, wherein a foam material having a high expansion ratio is set in the vicinity of the welded portion among the two or more kinds of foam materials. The method for manufacturing a sound-insulating body part according to claim 1, wherein the body part is made of a material containing aluminum. The method for manufacturing a sound insulating body part according to claim 1, wherein the foamable sound insulating material includes a foamable epoxy resin.

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