KR20110103064A - Bumper beam for car and menufacturing method thereof - Google Patents

Abstract

The present invention relates to a bumper beam for automobiles and a method for manufacturing the same, which is fixedly disposed between a cover and a stay, and installed in a front or rear of a vehicle, the bumper beam for automobiles absorbing a shock during a vehicle collision to protect a passenger; The bumper beam provides a bumper beam for automobiles, which is integrally formed by insert molding steel into a resin mat that is a long fiber reinforced composite material.
According to the present invention, a composite material having a kind of dendritic mat form and steel are integrated in a hybrid form to form a bumper beam, thereby making it possible to reduce the weight according to the weight reduction of the composite material, thereby contributing to cost reduction, securing strength and increasing collision stability. In addition, the effect of contributing to the improvement of molding stability and vehicle fuel efficiency can be obtained.

Description

BUMPER BEAM FOR CAR AND MANUFACTURING METHOD THEREOF {BUMPER BEAM FOR CAR AND MENUFACTURING METHOD THEREOF}

The present invention relates to a bumper beam for automobiles and a method of manufacturing the same, and more particularly, to reduce the bumper beam by using a hybrid method, thereby improving the fuel economy of the vehicle and preventing breakage of the beam during a high-speed collision test, thereby preventing airbag malfunction. The present invention relates to an improved bumper beam for automobiles and a method of manufacturing the same.

In general, the bumper beam for vehicles is to minimize the physical damage of the vehicle by elastically deforming at low speed collision of the vehicle, to absorb the impact during the collision to promote the safety of the occupants and at the same time to minimize the deformation of the vehicle body It is a cushioning means that is disposed in front and rear of the vehicle so that.

These bumper beams are usually made of steel, and are connected to a stay fixed to the vehicle body, thereby acting as a shock absorber in a vehicle crash.

However, when the bumper beam is made of steel, the vehicle weight increases and fuel efficiency is reduced, and thus, continuous technology development has been made to focus on weight reduction.

For example, a long fiber-reinforced thermoplastic (Long Fiber-Reinforced Thermoplastic) is also known to achieve a reduction in weight using a new material called a glass fiber mat thermoplastic (GMT).

Here, the long fiber-reinforced composite material is a plate-shaped composite material made of polypropylene resin and glass fiber mat reinforcement, which are general-purpose resins, and in particular, polypropylene in a molten state extruded through T-Die. And glass fiber non-woven mat are directly impregnated to provide excellent bonding strength with resin, and the strength of glass itself is reinforced on mat, which is superior to other materials. In addition, LFT (long fiber thermoplastic) is also included as a new material having characteristics such as lightness, design freedom, as well as high productivity and recyclability resulting from thermoplastic resins.

These materials can be reduced in weight, have excellent absorption of impact energy, improve design freedom, and are excellent in corrosion resistance, stiffness, resilience, sound insulation, vibration damping, and elastic impact resistance. I am getting it.

By forming a bumper beam with such a material and reinforcing the steel in the form of padding the web of the bumper beam, the amount of steel can be reduced and weight can be achieved, and the strength at the time of collision can be secured. there was.

However, in this case, since steel is simply padded on the material, the steel and the material are separated during the high-speed collision, thereby causing a problem of breaking the crashed part, thereby failing to secure desired crash test performance.

Accordingly, attempts have been made in which the bumper beam 10 having a longitudinal cross-section having a 'C-type', 'inverse C-type', 'H-type', and the like, as described above is shown in FIG. 1.

However, in this case, in order to satisfy the performance of the low speed crash test, high speed bogie test, high speed real vehicle test, etc., the weight of the composite material has to be increased, so it has a small weight compared with steel, but the cost burden is increased due to the characteristics of the material. .

In addition, in the case of front bumper beams, the provisions for the deployment / deployment of the prescribed airbags at high speed collisions are also to be satisfied.

The present invention was created in view of the above-described problems in the prior art, and inserts a bumper beam by a hybrid method in which a composite material and steel are integrated, and various laws and high-speed crash test performance as well as airbag deployment / The main problem is to provide a bumper beam for automobiles and a method of manufacturing the same to help improve fuel efficiency by reducing the weight, high strength, and low cost while satisfying the non-development performance.

According to an aspect of the present invention, there is provided a vehicle bumper beam disposed between a cover and a stay, and installed at a front or rear of a vehicle to absorb a shock during a vehicle collision to protect a passenger; The bumper beam provides a bumper beam for automobiles, which is integrally formed by insert molding steel into a resin mat that is a long fiber reinforced composite material.

At this time, the steel is characterized in that at least one rectangular hole is processed in order to reduce the weight and improve the bonding strength, the resin mat is joined to the wedge shape when the insert molding.

In addition, the rectangular hole is characterized in that the left and right symmetrical with respect to the longitudinal center of the steel.

In addition, the present invention is disposed between the cover and the stay fixed, and installed in the front or rear of the vehicle in the bumper beam manufacturing method for automobiles to protect the passengers by absorbing the impact during a vehicle crash; Providing a plurality of guide pins elastically flown through springs in place of the lower mold for producing the bumper beams; Stacking a resin mat of a heated long fiber reinforced composite material on top of the lower mold; Seating the processed steel in a bumper beam shape on the laminated resin mat, and fitting the stay fastening hole formed in the steel to the guide pin; The resin mat heated to the upper part of the steel is seated again, and the upper mold is closed and press-molded to form a resin mat with an even thickness, and during molding, the steel is not twisted, twisted or flowed uniformly inside the resin mat. Provided is a method for manufacturing a bumper beam for automobiles, which is embedded and integrated.

In this case, the long-fiber reinforced composite material is characterized in that the GMT or LFT.

According to the present invention, a composite material having a kind of dendritic mat form and steel are integrated in a hybrid form to form a bumper beam, thereby making it possible to reduce the weight according to the weight reduction of the composite material, thereby contributing to cost reduction, securing strength and increasing collision stability. In addition, the effect of contributing to the improvement of molding stability and vehicle fuel efficiency can be obtained.

1 is an exemplary view of a bumper beam according to the prior art.
2 is an exemplary view showing an installation example of a bumper beam according to the present invention.
3 is an exemplary view showing a hybrid molding method of a bumper beam according to the present invention.
4 is a view showing a low-speed crash test results of the bumper beam according to the present invention.
5 is a view showing the airbag deployment / non-development test results of the bumper beam according to the present invention.
6 is a view showing a fast bogie collision test results of the bumper beam according to the present invention.
7 and 8 are views showing the results of a high speed vehicle crash test of the bumper beam according to the present invention.

Hereinafter, with reference to the accompanying drawings will be described in detail a preferred embodiment according to the present invention.

As shown in FIG. 2, the bumper beam 100 for an automobile according to the present invention may have a steel 120 in a long fiber-reinforced thermoplastic (hereinafter referred to as a resin mat) 110. It is manufactured by insert molding.

In this case, the resin mat 110, the long fiber reinforced composite material includes a GMT or LFT.

The bumper beam 100 is coupled to the stay 200, and the stay 200 is fixed to the vehicle body.

In this case, at least one rectangular hole 122 is preferably formed in a part of the steel 120.

Here, the rectangular hole 122 is preferably formed to be symmetrical left and right from the center of the length of the steel 120, in particular, the rectangular hole 122 is the hybrid mat during the hybrid molding, that is, insert molding the resin mat ( This is to improve the bonding characteristics with 110).

In other words, the resin mat 110 pressurized in a heated state is embedded in the rectangular hole 122 formed in the steel 120 to be joined in a wedge shape to improve mutual bonding strength.

However, insert molding according to the present invention is difficult for those skilled in the art to mold into a simple insert form due to the following problems.

That is, since the steel 120 to be inserted should have a form embedded in the resin mat 110, the steel 120 is flowed by pressing force when the resin mat 110 is placed and the steel 120 is placed thereon under pressure. Warping or twisting may occur, causing mold failure.

In particular, since the bumper beam 100 is to be fixed to the stay 200, a fixing hole is formed in place, but the fixing holes are not matched due to the steel 120 flowing during molding, thereby causing a fastening failure.

In addition, the flow of the steel 120 when forming the bumper beam 100 causes a thickness variation of the resin mat 110, thereby preventing the crash test performance from being satisfied.

The present invention has been solved by molding in the same manner as in Figure 3 when hybrid molding, that is, insert molding in consideration of the difficulty in forming the bumper beam, and through various performance tests of the bumper beam 100 manufactured in such a manner A bumper beam that satisfies current regulations could be manufactured.

For example, as shown in Figure 3, while installing a plurality of guide pins 310 in place of the lower mold 300, the guide pins 310 to move up and down to enable elastic return by the spring (320) Configure it to be possible.

In this state, the heated resin mat 110 is stacked and seated on the upper portion of the lower mold 300.

Subsequently, the steel 120 processed in a bumper beam shape is seated on the laminated resin mat 110, and a hole (for fastening the stay) formed in the steel 120 is fitted to the guide pin 310.

Then, the resin mat 110 heated to the upper portion of the steel 120 is seated again, the upper mold 330 is closed and pressurized.

Then, the resin mat 110 is pressed by the upper mold 330 and the steel 120 is pressed. As the guide pin 310 moves downward together, the spring 320 is elastically compressed, and the upper mold 330 is The lower mold 300 is correctly engaged.

At this time, the guide pin 310 is not pressed by the thickness of the steel 120 in the state fitted to the steel 120, so that the steel 120 does not flow even by the pressure applied to maintain the place, The resin mat 110 is molded to have an even thickness, and the steel 120 is also uniformly inserted into the resin mat 110 without being twisted, twisted or flowed to form a single body.

In this way, when the molding is completed, by separating the upper mold 330 and the lower mold 300, by ejecting the bumper beam 100 of the product can finally complete the bumper beam 100 according to the present invention.

In order to test the performance of the bumper beam 100 thus formed, it was tested under each test condition.

For example, in the case of the slow collision test, as shown in FIG. 4, the intrusion performance was satisfied and there was no damage.

In other words, it satisfies all specifications of FMVSS PART 581 Intrusion Spec: 94mm, IIHS FULL BARRIER Intrusion Spec: 172mm, and IIHS 15% offset barrier Intrusion Spec: 110mm.

In addition, it was confirmed that the intrusion was lower than the specified value even when IIHS FULL & 15% offset barrier collision resulted in satisfying all of the specified specification.

In particular, in the case of the low-speed collision test, the United States, which adopted it for the first time, adopts all safety-related regulations as FMVSS. However, the low-speed collision test in other countries is regulated by a separate regulation rather than the FMVSS regulations.

In addition, in the case of the airbag deployment / non-development test, as shown in FIG. 5, it was confirmed that the airbag deployment / non-development was clearly satisfied based on the threshold line as shown in the test graph. In addition, it was confirmed that the crack fracture portion of the bumper beam appeared uniformly.

In other words, the airbag was deployed at a speed of 18 kph, but not at 12 kph.

At this time, the airbag deployment / deployment criteria is 40% Offset collision below 15kph, the airbag should not burst in frontal collision below 8 ~ 10mph as shown in the figure below. It must be deployed.

In addition, the test requirements should be created in the Threshold Line Zone as shown below based on the airbag deployment / deployment conditions, the present invention confirmed that this zone was created.

In the case of the high-speed bogie collision test, as shown in FIG. 6, as a result of the 26.3 kph offset collision and the 32.3 kph flat barrier test, as shown in the graph, in the case of the 26.3 kph offset collision, an initial peak value of the steel is shown. The 2G (deceleration) was shown to be high, and the 32.3kph flat barrier test showed an initial peak value of 1G higher than that of steel, which reduced the impact from passengers.

In other words, when the initial pitch is high, the impact is reduced after the collision to secure stability. When the initial pitch is low, the subsequent pitch is generated and the secondary impact is applied to harm the safety of the passenger, so the initial pitch must be high. The initial pitch was found to be much higher.

In other words, the higher the initial deceleration, the smaller the injury to human injury during collision.

Finally, in the case of the high speed vehicle crash test, as shown in FIG. 7 and FIG. 8, the 56kph frontal collision and the 64kph offset collision were tested. As a result of the 56kph frontal collision, the bumper beam does not break as shown in the graph. It has been confirmed that the same effect was confirmed in the case of 64kph offset collision.

In other words, the test is conducted with a frontal collision 56kph and a US IIHS 40% Deformable Offset collision 64kph based on domestic car regulations. Good, Acceptable, Marginal, Poor).

Also, most importantly, there should be no breaking of the beam in the event of a collision.

In the case of the bumper beam according to the present invention, a 56 kph frontal collision 5 star and IIHS offset were able to be judged good.

In addition, the bumper beam was not broken after the collision.

As a result, the bumper beam 100 according to the present invention is capable of hybrid molding while satisfying both the legal test and the commerciality test, thereby reducing the weight while increasing the strength, and having the uniform and stable shock absorbency. It is expected that the bumper beam made of the mat alone can be sufficiently replaced.

100 bumper beam 110 resin mat
120: steel 200: stay
300: lower mold 310: guide pin
320: spring 330: upper mold

Claims (6)

A bumper beam for a vehicle disposed between and fixed between a cover and a stay, and installed at a front or rear of a vehicle to absorb a shock during a vehicle collision to protect a passenger;
The bumper beam is a bumper beam for automobiles, characterized in that the steel is inserted into the resin mat is a long fiber reinforced composite material. The method according to claim 1;
The long mat fiber reinforced composite material is a bumper beam for automobiles, characterized in that the GMT or LFT. The method according to claim 1;
The steel bumper beam is characterized in that at least one rectangular hole is processed to reduce weight and improve bonding strength, so that the resin mat is joined in a wedge shape when the insert is formed. The method according to claim 2;
The rectangular hole bumper beam, characterized in that the left and right symmetrical with respect to the longitudinal center of the steel. A method for manufacturing a bumper beam for automobiles, which is disposed between the cover and the stay and is installed at the front or rear of the vehicle to absorb shocks during a vehicle collision to protect passengers;
Providing a plurality of guide pins elastically flown through springs in place of the lower mold for producing the bumper beams;
Stacking a resin mat of a heated long fiber reinforced composite material on top of the lower mold;
Seating the processed steel in a bumper beam shape on the laminated resin mat, and fitting the stay fastening hole formed in the steel to the guide pin;
The resin mat heated to the upper part of the steel is seated again, and the upper mold is closed and press-molded to form a resin mat with an even thickness. A method for manufacturing a bumper beam for automobiles, which is embedded and integrated. The method of claim 5, further comprising:
Resin mat is a long fiber reinforced composite material is a vehicle bumper beam manufacturing method characterized in that the GMT or LFT.

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