JP4020459B2 - Filling confirmation method of foam-cured foam - Google Patents

Description

[0001]
BACKGROUND OF THE INVENTION
The present invention relates to a method for confirming filling of foam-cured foam, more specifically, when a two-component foamable material is injected into a closed cross section of a vehicle body member having a closed cross-section structure, and the foam cured foam is filled by foam curing. The present invention relates to a method for measuring and detecting the temperature difference between a filled part and an unfilled part from the outside in a non-contact manner in order to confirm the appropriate filling capacity corresponding to the volume inside the closed section.
[0002]
[Prior art and problems to be solved by the invention]
In the automobile industry in Japan, improvement of the rigidity and strength of the entire vehicle body is being studied for the purpose of improving the collision safety of vehicles. In this way, the demand for automobile crash safety in Japan has become increasingly severe, and production of vehicles with higher safety is being demanded.
[0003]
By the way, as a measure to improve the collision safety, each automobile manufacturer has studied the reinforcement structure with steel plate and developed its own body structure, but avoid the weight increase per car (generally 30-50kg). I can't.
In addition to such structural reinforcement, a vehicle body member to which a lot of loads such as impacts are applied, for example, a center pillar having a closed cross-section structure and a front pillar having a closed cross-section structure of a front vehicle body, which is mounted with a belt anchor of a seat belt device. A foam-cured foam that functions as a reinforcing material by injecting a two-component foamable material into pillars, etc., into their closed section (usually installing partition partitions to form a closed section) Filling is being considered.
[0004]
This foam-cured foam filling technology takes into account the foaming ratio and other foaming conditions of a two-part foamable material, and injects in a desired range by quantitatively injecting it in an amount commensurate with the volume inside the closed section to be filled. A vehicle body member having a closed cross-sectional structure such as the center pillar or the front pillar filled with the hardened foam can be obtained.
However, when a failure occurs in the injection device or the like as an unexpected situation, it is predicted that if the filling capacity of the foam-cured foam is insufficient below the desired range, a hollow portion is generated and the strength as designed cannot be obtained. Further, it is conceivable that the filling capacity is insufficient due to an unexpected loss of the partition plate provided in the closed cross section.
Actually, there is no way to prevent such a shortage of filling capacity, and it is currently possible to determine the suitability of the filling capacity for the first time by performing a crash test, measuring the rigidity of the actual vehicle, or analyzing the vibration after the production line. During the production line, it was difficult to guarantee the design strength and rigidity of the car.
[0005]
[Means for Solving the Problems]
The present inventors have made extensive studies to prevent such problems due to insufficient filling capacity and to properly fill and reinforce the foam-cured foam. It was noted that when a two-component foaming material was injected into the body, heat was generated simultaneously with foaming due to the reaction, and this heat generation increased the panel temperature at the filling portion of the vehicle body member. That is, if the temperature near the limit position where the foam-cured foam finally arrives on the side of the vehicle body member is measured from the outside without contact, the filled portion and the unfilled portion can be distinguished from each other by the temperature difference. The present inventors have found that it is possible to confirm the appropriateness of the filling capacity corresponding to the volume, and have completed the present invention.
[0006]
That is, according to the present invention, when a two-component foamable material is injected into a closed cross-section of a vehicle body member having a closed cross-sectional structure, and a foam-cured foam is filled by foam hardening, a filling capacity corresponding to the volume inside the closed cross-section is provided. In order to confirm the suitability of the foam-cured foam, the temperature of the body member is measured from the outside in a non-contact manner, and the suitability of the filling capacity is confirmed by the temperature difference between the filled portion and the unfilled portion. A filling confirmation method is provided.
[0007]
As a vehicle body member having a closed cross-sectional structure in the present invention, for example, as shown in FIG. 1, a front roof 1 (configured by a roof rail inner and a roof rail outer) and a front side roof rail 2 (configured by a front side outer panel and a side roof rail inner) are shown. Examples include a structural member in which a front pillar 3 (consisting of a front side outer panel and a front pillar inner) is connected, and partition plates 4 and 5 are installed inside the front side roof rail 2 and the front pillar 3, respectively. An injection hole 6 is formed in the side roof rail 2.
[0008]
In the present invention, the two-pack type foamable material injected into the injection hole 6 is not particularly limited as long as it can be foam-cured at room temperature. For example, a polyol main agent [polyhydric alcohol, bisphenols, A polyether polyol obtained by addition reaction of an alkylene oxide with an active hydrogen-containing compound such as various amines is preferable] and a polyisocyanate curing agent [aromatic polyisocyanate, aliphatic or alicyclic polyisocyanate, aromatic aliphatic polyisocyanate]. Isocyanate, various modified products thereof, terminal NCO group-containing urethane prepolymer obtained by reaction of polyols with excess polyisocyanate compound, etc.], and a foaming agent [water, pyrolytic chemical foaming agent ( Azodicarbodiamide, p, p'-oxybisbenzenesulfonyl hydrazide, etc.), no thermal decomposition Machine foaming agent (such as sodium bicarbonate), thermal expansion type microballoon (in which polymer capsules are encapsulated with a low boiling point solvent such as pentane, heptane, etc.), and further, if necessary, reaction catalyst, chain extender, It is preferable to use a two-component foamable urethane material to which a foam stabilizer, a colorant, a plasticizer, a filler, a flame retardant, an anti-aging agent, an antioxidant, and the like are added.
[0009]
DETAILED DESCRIPTION OF THE INVENTION
The method for confirming the filling of foam-cured foam according to the present invention is a method for measuring the temperature difference between the filled part and the unfilled part by measuring the temperature from the outside in a non-contact manner on the side surface of the vehicle body member as shown in FIG. is there. For example, in FIG. 1, when a two-component foam material is injected from the injection hole 6, the foam material first proceeds while being foam-cured (simultaneously generated heat) toward the front pillar 3, and then spreads to the front side roof rail 2. It goes around the upper end and the corner, and finally proceeds upward of the front roof 1 to reach the limit position P shown in the figure. Here, the panel temperature of the filling portion in the vehicle body member rises due to the heat generation temperature (generally around 170 ° C.) of the filler (foamed and cured foam). The rate of temperature rise varies depending on whether the panel is thick or has a double structure, but as a guideline, it takes 1-5 minutes (2-5 minutes if the board is thicker than necessary) over time, An increase in the panel temperature can be confirmed, and generally reaches 50 to 100 ° C. (in contrast, the panel temperature at the unfilled site is slightly higher than the ambient temperature, being 40 ° C. or less). Therefore, if the panel temperature at the filling side surface is measured in a non-contact manner within the above-mentioned time range after injection of the two-component foamable material and foam curing, the temperature difference (usually 10 ° C or higher, preferably 20 ° C or higher) ) Makes it possible to distinguish between filled and unfilled parts, which allows you to check the appropriateness of the filling capacity, and at the same time guarantees the strength and rigidity of the design. Can be avoided in advance.
[0010]
In addition, when insufficient filling is detected, a separate injection hole may be provided in the unfilled portion, and replenishment injection of the two-pack type foamable material may be performed.
In the non-contact temperature measurement, “infrared rays naturally emitted from an object are captured, the surface temperature of the object is displayed in multiple points without contact, or the temperature distribution is provided as thermal image data”. What is called an image device or an infrared radiation thermometer may be used.
In addition, when the measurement object exceeds the monitoring set temperature range, the temperature of the filled part and the unfilled part is measured at the same time by using a device with a function to output a proper signal and notify normality. It is also possible to introduce a device that detects the difference and generates a warning signal when the temperature difference does not reach 10 ° C. or more.
[0011]
【Example】
Next, an Example is given and this invention is demonstrated more concretely.
Example 1
From the injection hole 6 (diameter 20 mm) of the vehicle body member (closed cross-section internal volume: 1250 cc) shown in FIG. 1, a two-pack foaming urethane material (density after foaming 350 kg / m ³ ) is 5 kg / min with a high-pressure foaming machine. After injecting 438 g at a rate of 2 minutes, after 2 minutes of foaming, the panel temperature of the part (points A to F) shown in FIG. 1 using an infrared thermal imager (Japan Avionics, TVS-110). As a result, A point = 58 ° C., B point = 54 ° C., C point = 63 ° C., D point = 22 ° C., E point = 20 ° C., and F point = 25 ° C.
Further, the entire panel temperature distribution including the points A to F was observed with the same apparatus.
Furthermore, if the temperature difference between each of the two points (A and D, B and E, C and F) is less than 10 ° C, a warning signal is issued and the same device with an alarm function set to sound a buzzer is also measured. However, it was confirmed that the buzzer did not sound.
[0012]
【The invention's effect】
In the present invention having the above-described configuration, whether or not the desired range can be filled by measuring the panel temperature in a non-contact manner within a predetermined time range after the injection of the two-component foamable material and the foam curing is confirmed. We can confirm the strength and rigidity of the design based on the premise that such filler reinforcement is applied, and we have put to practical use a foam filler application method that meets the social needs of light weight and improved body strength and rigidity. It can be an effective means.
[Brief description of the drawings]
FIG. 1 is a schematic view showing an example of a vehicle body member having a closed cross-sectional structure in the present invention.
[Explanation of symbols]
1: Front roof 2: Front side roof rail 3: Front pillar 6: Injection hole

Claims (3)

In an automobile production line, when a two-component foamable material is injected into a closed cross-section of a body member having a closed cross-sectional structure, and a foam-cured foam is filled by foam curing, a filling capacity corresponding to the volume inside the closed cross-section is obtained. In order to confirm appropriateness, within 1 to 5 minutes after the injection of the material, temperature measurement is performed from the outside in a non-contact manner with respect to the side surface of the vehicle body member, The filling confirmation method of the foaming hardening foam in the automobile production line characterized by confirming the appropriate filling capacity by the temperature difference of the unfilled part.   The filling confirmation method according to claim 1, wherein the temperature difference is 10 ° C. or more.   The filling confirmation method according to claim 1, wherein an infrared thermal image device or an infrared radiation thermometer is used for temperature measurement.

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