JP2003002058A - Mounting structure and mounting method of vehicle reinforcement member - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide a mounting structure and a mounting method of a vehicle reinforcement member capable of ensuring junction strength of the vehicle reinforcement member and a counter member by inhibiting corrosion of a welded part of both members. SOLUTION: In a mounting structure of a door impact beam, a bracket part 14 is mounted to a door inner panel 16 by spot welding in the state that a coating film layer 21 and a plating layer 15 are interposed between the bracket part 14 of the door impact beam 11 and the door inner panel 16. A nugget 22 is formed on a welded part of the bracket 14 and the door inner panel 16 and the junction strength of the welded part of both members is ensured by this nugget 22. Since the coating film layer 21 and the plating layer 15 become consumable layers, even in the case where it is contacted with rain water or the like, the coating film layer 21 and the plating layer 15 are corroded prior to the corrosion of the nugget, and the nugget 22 is hardly corroded.

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a vehicle reinforcing member mounting structure and method, and more particularly to a door impact beam, a door inner reinforcement, and a center integrally formed from a steel plate to have a predetermined shape. The present invention relates to a mounting structure and a mounting method in which a vehicle reinforcing member such as a pillar is mounted on a metal counterpart member (vehicle member) by spot welding.

[0002]

2. Description of the Related Art In recent years, there has been an increasing demand for strengthening safety measures for vehicles, and a reinforcing member is attached to a part of the vehicle to reinforce it. Here, when a door impact beam (reinforcing member for vehicle) that is horizontally installed inside the door of the vehicle to absorb and mitigate the impact at the time of a side collision is attached to the door inner panel (counter member) by spot welding. Taking the above as an example, a conventional technique relating to a mounting structure and a mounting method for a vehicle reinforcing member will be described below.

As shown in FIG. 1, a door impact beam 11 has a main body 1 located at the center thereof and having a substantially inverted U-shaped cross section.
2 and bracket portions 1 located at both ends thereof and having a substantially flat plate shape
3 and 14, and a steel plate (for example, a plate thickness of 1.6 mm
Of high-strength steel). The door impact beam 11 has a high tensile strength (for example, about 1500 MPa) in order to cope with the enhancement of vehicle safety measures.

The door impact beam 11 of the embodiment shown in FIG. 1 has a steel plate at a high temperature (for example, 9 ° C.) lower than the melting point of the steel product.
Formed into a predetermined shape by sequentially performing a heating step of heating to 30 ° C.) and a press step of performing press working on a steel plate in a high temperature state using a relatively low temperature (for example, room temperature) press die. Has been done. In this way, high tensile strength is obtained by adopting the method of heating the steel sheet in advance and pressing it with the press die at room temperature in the high temperature state (hereinafter, referred to as “hot stamping method”). It is possible to obtain the door impact beam 11 having

Then, as shown in FIGS. 2 and 3, a plating layer 15 (eg, a zinc plating layer) is formed on the surface of each bracket portion 13 and 14 of the door impact beam 11 having a desired tensile strength. Metal door inner panel 1
By attaching to 6 by spot welding, the door impact beam 11 is installed horizontally in the interior of the door 17, and the door impact beam 11 is attached to the door inner panel 16 to form a door impact beam attachment structure.

In this case, the nugget 18 shown in black in FIG. 3 is formed at the welded portion between the bracket portion 14 of the door impact beam 11 and the door inner panel 16, and the bracket portion 14 of the door impact beam 11 is formed.
Also, the door inner panel 16 having the plating layer 15 has recesses 19 and 2 due to the pressing force of both electrodes during spot welding.
0 is formed respectively. Before spot welding, the plating layer 15 exists on the entire surface of the door inner panel 16, but after spot welding, as shown in FIG. 3, the nugget 18 of the door inner panel 16 is removed. The plating layer 15 does not exist in the vicinity. This is because the plating layer 15 was melted under the influence of heat during spot welding.

The door impact beam 11 is mounted between the door inner panel 16 and a door outer panel (not shown), and the door impact beam 11 is mounted in the mounted state.
Cationic electrodeposition coating is applied to the etc.
In FIG. 3, a coating layer and a door outer panel formed on the surface of the door impact beam 11 or the like by cationic electrodeposition coating are omitted without being drawn.

As described above, in the door impact beam mounting structure and mounting method, the door impact beam 11 is formed by the nugget 18 formed by spot welding.
The joint strength of the welded portion between the door inner panel 16 and the door inner panel 16 is ensured.

[0009]

However, the above-described conventional door impact beam mounting structure and mounting method have the following problems.

That is, regarding the door impact beam mounting structure and method according to the prior art, although a coating layer having a rust preventive function is formed on the surface of the door impact beam 11 or the like by cationic electrodeposition coating, Since the paint does not easily penetrate between the bracket portions 13 and 14 of the impact beam 11 and the door inner panel 16 and does not spread to every corner, there is a possibility that a coating layer having an anticorrosive function may not be formed between both members. is there.

Therefore, when the rainwater that has penetrated into the interior of the door 17 further penetrates between both members and contacts the welded portion (nugget 18), or the door impact beam 11 is used under severe conditions such as a wet atmosphere. Corrosion easily occurs or progresses in the welded portions of the bracket portions 13 and 14 of the door impact beam 11 and the door inner panel 16, and the joint strength of the welded portions of both members is extremely reduced due to the corrosion. I will end up. As a result, the door impact beam 11
There is a risk that sufficient strength may not be obtained when the vehicle is impacted from the outside, and the function of the door impact beam 11 as a vehicle reinforcing member may not be exerted.

When manufacturing a door impact beam, it is conceivable to previously form a plating layer or a coating layer having a rust preventive function on a steel plate, but the steel plate is integrally formed to have a predetermined shape. When doing so, a portion such as a loss of the plating layer or the coating layer is generated from the steel plate, so it cannot be said that the rust prevention function of the door impact beam itself is sufficient. In particular, when hot working such as hot stamping or quenching treatment is applied to a steel sheet, the heat input may oxidize the plating layer or coating film layer, and may cause melting damage or peeling. The deterioration of the anti-corrosion function of the impact beam itself becomes significant. Therefore, even when the steel sheet is previously subjected to anticorrosion treatment such as plating treatment, the problem of corrosion in the welded portion between the door impact beam and the door inner panel remains.

The present invention has been made in view of the above-mentioned circumstances, and an object thereof is to suppress corrosion in a welded portion between a vehicle reinforcing member and a mating member and to secure joint strength of the welded portion. An object of the present invention is to provide a mounting structure and a mounting method for a reinforcing member for a vehicle.

[0014]

In order to achieve the above object, the mounting structure for a vehicle reinforcing member according to the invention of claim 1 is a vehicle reinforcing member integrally formed from a steel plate to have a predetermined shape. A counterpart member made of metal, and the vehicle reinforcement member to the counterpart member by spot welding in a state in which a coating layer made of a conductive paint is interposed between the vehicle reinforcement member and the counterpart member. The point is that it is installed.

According to the first aspect of the present invention, the vehicle reinforcing member is formed by spot welding with the coating layer made of conductive paint interposed between the vehicle reinforcing member and the mating member. Since it is attached to the vehicle, a nugget is formed at the welded portion between the vehicle reinforcing member and the mating member. In this case, since the coating layer made of the conductive paint has conductivity, spot welding can be performed in a good state at the welded portion between the vehicle reinforcing member and the mating member. The nugget formed by such spot welding ensures the joint strength of the welded portion between the vehicle reinforcing member and the mating member.

Further, since the coating layer having a rust preventive function interposed between the vehicle reinforcing member and the mating member contains a sacrificial material (because it is a sacrificial layer), it is possible to prevent Even when rainwater or the like enters, the sacrificial material is first corroded, and the welded portion between the vehicle reinforcing member and the mating member is less likely to be corroded. As a result, corrosion is suppressed in the welded portion of the vehicle reinforcing member and the mating member, and a decrease in joint strength in the welded portion of both members is suppressed. Therefore, the durability and reliability of the mounting structure of the vehicle reinforcing member can be improved, and the function of the vehicle reinforcing member can be sufficiently exhibited.

According to a second aspect of the present invention, in the vehicle reinforcing member mounting structure according to the first aspect, the steel plate is made of any one of high-strength steel, high-strength steel and ultra-high-strength steel. Is the gist. Where "high-strength steel"
Is the addition of a small amount of alloying elements to low carbon steel.
A steel material having a tensile strength of 0 to 1000 MPa, which is also called a high-tensile material. Further, the "strong steel" means an alloy steel for machine structure having a tensile strength of 900 to 1300 MPa,
With a carbon content of 0.25 to 0.5% by weight, silicon, manganese,
It has a composition of chromium, nickel, molybdenum, or the like. For example, as a tough steel, Mn steel, M in JIS
n-Cr steel, Cr steel, Cr-Mo steel, Ni-Cr steel, N
i-Cr-Mo steel is mentioned. Furthermore, "super-strength steel (super-strength steel)" refers to one having a tensile strength of 1300 MPa or more and the highest strength level among steel materials.

According to the invention described in claim 2, in addition to the action of the invention described in claim 1, a steel sheet made of any one of high-strength steel, high-strength steel and super-strength steel is excellent. Since it has tensile strength (400 MPa or more), the vehicle reinforcing member integrally formed from the steel sheet also has excellent tensile strength, and the function as the vehicle reinforcing member is more reliably exhibited. Like

According to a third aspect of the present invention, in the vehicle reinforcing member mounting structure according to the first or second aspect, the coating layer is a binder made of an epoxy resin, and the binder is dispersed in the binder. The gist of the invention is that it is composed of a conductive paint with a conductive filler made of zinc.

According to the third aspect of the present invention, in addition to the effects of the first and second aspects of the present invention, a binder made of an epoxy resin and a conductive material made of zinc dispersed in the binder are used. A coating layer made of a conductive paint with a filler is excellent in weldability, rust prevention and weather resistance, so that the coating layer is interposed between the vehicle reinforcing member and the mating member. Even if spot welding is performed with, the weldability, rust prevention and weather resistance of the coating layer can be reliably exhibited. Therefore,
Since the mounting structure of the vehicle reinforcing member is maintained in a stable state for a long period of time, the durability and reliability of the mounting structure of the vehicle reinforcing member are further improved. In addition,
The conductive filler made of zinc in the coating layer serves as a sacrificial material.

According to a fourth aspect of the present invention, in the vehicle reinforcing member mounting structure according to any one of the first to third aspects, the vehicle reinforcing member is a door impact beam, and The mating member is a door inner panel having a plating layer formed on the surface thereof, the coating layer is formed only on the bracket portions integrally formed at both ends of the door impact beam, and the coating layer and the plating layer are formed. The gist is that the bracket portion is attached to the door inner panel by spot welding in a state of being interposed.

The invention according to claim 4 relates to a structure for mounting a door impact beam as a vehicle reinforcing member,
The effects of the inventions of claim 1, claim 2, and claim 3 are achieved. According to this mounting structure, the bracket portion of the door impact beam and the door inner panel are mounted by spot welding in a state in which two layers of a coating layer and a plating layer having an anticorrosion function are interposed, and thus the bracket portion. The corrosion of the welded part between the door and inner panel is reliably suppressed,
The joint strength of the welded portions of both members can be more reliably ensured. Further, since the coating film layer is formed only on the bracket portion of the door impact beam, increase in manufacturing cost can be suppressed as much as possible.

According to a fifth aspect of the present invention, there is provided a method of mounting a vehicle reinforcing member, wherein a vehicle reinforcing member integrally formed from a steel plate into a predetermined shape and a metallic counterpart member are provided on the vehicle reinforcing member side. The coating step of applying a conductive paint to the contact surface to form a coating layer and the welding step of attaching the vehicle reinforcing member to the mating member by spot welding with the coating layer in between are sequentially performed. That is the gist.

According to the invention described in claim 5, by performing the coating step and the welding step in this order, the mounting structure of the vehicle reinforcing member having the function of the invention described in claim 1 can be obtained. .

According to a sixth aspect of the present invention, in the method of mounting the vehicle reinforcing member according to the fifth aspect, the coated surface of the vehicle reinforcing member is cleaned by sand blasting or shot blasting before performing the coating step. The main point is to carry out the cleaning process.

According to the invention described in claim 6, in addition to the function of the invention described in claim 5, by performing the cleaning step before the coating step, the coated surface (contact) of the vehicle reinforcing member is contacted. The surface) is cleaned by sand blasting or shot blasting to remove oxides such as rust on the coated surface and oils and fats, so that the coated surface of the vehicle reinforcing member is coated in a good state. In addition, since the coated surface of the vehicle reinforcing member is clean and a coating layer is formed on the coated surface to protect the coated surface, the coated surface of the vehicle reinforcing member is less likely to be corroded. There is.

[0027]

BEST MODE FOR CARRYING OUT THE INVENTION An embodiment in which the present invention is embodied in a door impact beam mounting structure and mounting method will be described with reference to FIG. However, the door impact beam of the present embodiment is the door impact beam of the mode shown in FIG. 1, and since the outline of the configuration, the mounting structure, etc. has already been described, the description thereof will be omitted in the present embodiment. In some cases, it may be performed, and in some cases, supplementary description may be made with reference to FIGS. 1 and 2.

The door impact beam 11 of the embodiment shown in FIG. 1 is integrally formed from a high-tensile steel plate having a plate thickness of 1.6 mm. This high strength steel contains 0.21% by weight of C, 0.2
2 wt% Si, 1.24 wt% Mn, 0.20 wt% Cr, 0.022 wt% Ti, 0.0015 wt% B, 0.012 wt% P, 0.001 wt% % S and the balance Fe and unavoidable impurities.

As the high-strength steel, 0.18 to 0.
25 wt% C, 0.15-0.35 wt% Si,
1.15 to 1.40 wt% Mn, 0.15 to 0.25
Wt% Cr, 0.01-0.03 wt% Ti, 0.
It is preferable to use a high-strength steel containing B of 0005 to 0.0025% by weight, P of 0.03% by weight or less, S of 0.01% by weight or less, and the balance of Fe and inevitable impurities. The melting point is 1300 to 1400 ° C and the tensile strength is 500 to 600 MPa.

Door impact beam 11 of the present embodiment
Unlike the door impact beam according to the conventional technology,
A coating layer 21 with a film thickness of 25 μm having a rust preventive function on the contact surfaces of the bracket portions 13 and 14 with the door inner panel 16
(See FIG. 4) are formed. The coating layer 21 is made of a one-pack type conductive coating material including a binder made of an epoxy ester resin and a conductive filler made of zinc (particles) scattered in the binder, and has conductivity, and Excellent in weldability, rust resistance and weather resistance. Further, the conductive filler made of zinc in the coating layer 21 functions as a sacrificial material, and it can be said that the coating layer 21 itself is a sacrificial layer.

Door impact beam 11 of the present embodiment
Similarly, as shown in FIG. 2, the bracket portions 13 and 14 at both ends are attached by spot welding to a metal door inner panel 16 having a plating layer 15 (for example, a zinc plating layer) formed on the surface. And is installed horizontally inside the door 17. However, although the appearance is the same as that of FIG. 2, as will be described later, in the present embodiment, between the bracket portions 13 and 14 and the door inner panel 16 having the plating layer 15 formed on the surface thereof. It is attached by spot welding with the coating layer 21 interposed (FIG. 4).
reference). The plated layer 15 serves as a sacrificial layer.

As shown in FIG. 4, the bracket portions 13 and 14 having the coating layer 21 of the door impact beam 11 are provided.
Is attached to the door inner panel 16 provided with the plated layer 15 by spot welding, whereby the door impact beam 11 has a door impact beam attachment structure attached to the door inner panel 16. In this case, the nugget 22 shown in black in FIG. 4 is formed at the welded portion between the bracket portion 14 of the door impact beam 11 and the door inner panel 16, and the door impact beam 1
The door inner panel 16 provided with the bracket portion 14 and the plated layer 15 of No. 1 has recesses 19 and 20 formed by the pressing force of both electrodes at the time of spot welding.

Before spot welding, the coating layer 21 is present only on the bracket portions 13 and 14, and
The plating layer 15 is present on the entire surface of the door inner panel 16, but after spot welding, as shown in FIG. 4, the plating layer 15 is applied to the bracket portion 14 and the vicinity of the nugget 22 of the door inner panel 16. The film layer 21 and the plating layer 15 are not present. This is because the coating layer 21 and the plating layer 15 were melted under the influence of heat during spot welding. Needless to say, the same phenomenon as that of the bracket portion 14 and the like occurs in the bracket portion 13 and the like not shown in FIG.

The door impact beam 11 is mounted between the door inner panel 16 and a door outer panel (not shown).
Cationic electrodeposition coating is applied to the etc.
In addition, in FIG. 4, the coating layer and the door outer panel formed on the surface of the door impact beam 11 and the like by the cationic electrodeposition coating are omitted without being drawn.

Door impact beam 11 of this embodiment
Is a heating step of heating the above-mentioned steel sheet made of high-strength steel to a high temperature below its melting point, and pressing the steel sheet in the high temperature state using a relatively low temperature (for example, room temperature) press die. The door impact beam 11 of the embodiment shown in FIG. 1 is manufactured by sequentially performing the pressing process.

More specifically, in the heating step, the steel sheet was heated by a heating device so as to reach a predetermined target temperature (930 ° C. in the present embodiment). In the heating device of the present embodiment, the temperature is gradually raised from room temperature to reach the target temperature, and then the target temperature is maintained. Further, when the steel sheet is heated by the heating device, it is preferable to perform it in an inert gas atmosphere (for example, a nitrogen gas atmosphere).

Next, in the pressing step, the steel sheet heated to the target temperature is immediately pressed. That is, the temperature of the steel sheet immediately before pressing was kept below 850 ° C. within 5 seconds until the steel sheet was set apart from the heating device and set in the press machine and the pressing operation was started. On the other hand, the temperature of the fixed die and the movable die as the press die was kept at room temperature. This is intended to give a corresponding temperature difference between the steel plate in the high temperature state and the press die at room temperature so that the quenching effect occurs when the steel plate in the high temperature state comes into contact with the cold press die.

Further, the pressure (pressing pressure) for pressing the movable die against the fixed die is 1000 MPa to 10000 MPa.
(In this embodiment, it is set to about 5000 MPa), and the time required for one pressing step until the movable die moves from the top dead center position to the bottom dead center position and returns to the top dead center position again is 5 seconds. Within After the pressing is completed, the temperature of the door impact beam immediately after being taken out from the press die is 100
Although the temperature was up to 200 ° C, it was allowed to cool naturally for several tens of seconds, and the temperature reached near room temperature.

As described above, by using the hot stamping method for hot working and quenching the steel sheet, the door impact beam 11 is integrally formed from the steel sheet to have a predetermined shape, and the embodiment shown in FIG. The door impact beam 11 is obtained. The tensile strength of the door impact beam 11 is about 1500 MPa, which is 500 to 60 before processing.
The tensile strength was increased from 0 MPa to about 900 to 1000 MPa. Then, by performing a cleaning step of cleaning the coated surfaces (contact surfaces) of the bracket portions 13 and 14 of the door impact beam 11 by sand blasting or shot blasting, oxides such as rust on the coated surfaces and oils and fats are removed.

After the cleaning step, a coating step of forming the coating layer 21 by coating the conductive coating on the coating surfaces of the bracket portions 13 and 14 of the door impact beam 11 is performed. As a result, the coating film layer 21 having a film thickness of 25 μm is formed on the coated surfaces of the bracket portions 13 and 14. In the present embodiment, airless spray coating is used as the method for coating the conductive paint. Here, the film thickness of the coating layer 21 is 50
It is preferable to set it to be not more than μm.

Finally, the door impact beam 1 is spot-welded with the coating layer 21 and the plating layer 15 interposed therebetween.
The welding process of attaching 1 to the door inner panel 16 is performed. Thereby, in the mode shown in FIG. 4 (see FIG. 2),
Each bracket portion 13 and 14 of the door impact beam 11
A door impact beam mounting structure in which the above is mounted on the door inner panel 16 is obtained.

According to this embodiment described in detail above, the following effects can be obtained.

As the door impact beam 101 according to another prior art, the one shown in FIG. 7 is known. This door impact beam 101 includes a beam body 102 made of a cylindrical hardened steel pipe, and the beam body 1
A pair of metal brackets 10 provided at both ends of 02.
3, 104, and both members are joined and integrated by welding.

According to the present embodiment, since the door impact beam 11 is integrally formed by the hot stamping method, the door impact beam of the mode shown in FIG. 7 in which the members obtained by the different steps are integrally manufactured. Beam 101
As compared with the above, it is possible to suppress a decrease in workability and a large increase in manufacturing cost during manufacturing of the door impact beam 11.

In this embodiment, by adopting the hot stamping method, the door impact beam 11 having a tensile strength equivalent to 1500 MPa can be manufactured.

According to the hot stamping method of the present embodiment, when the steel sheet is pressed by the press die, a temperature difference is provided between the steel sheet in a high temperature state and the press die at room temperature during press working. It is possible to perform shaping with a press and quenching at the same time. As a result, the manufacturing process of the door impact beam 11 can be simplified, so that the productivity of the door impact beam 11 can be improved.

In the present embodiment, the bracket portions 13 and 14 of the door impact beam 11 and the door inner panel 1
6 with the coating layer 21 and the plating layer 15 interposed between the bracket portions 13 and 14 by spot welding.
Is attached to the door inner panel 16. In this case, since both the coating layer 21 and the plating layer 15 have conductivity, the spot welding in the welded portion between the bracket portions 13 and 14 of the door impact beam 11 and the door inner panel 16 is favorable. Can be done in a state,
The joint strength of the welded portions of both members can be secured.

According to the present embodiment, the coating layer 21 and the plating layer 15 interposed between the bracket portions 13 and 14 of the door impact beam 11 and the door inner panel 16.
Since both layers are sacrificial layers, even if rainwater or the like enters between the coating layer 21 and the plating layer 15, those sacrificial layers will be corroded first, and the bracket portion 1
Corrosion of the nugget 22, which is a welded portion between the door inner panel 16 and the door inner panel 16, can be suppressed.

According to the present embodiment, since the corrosion of the welded portions (nugget 22) between the bracket portions 13 and 14 of the door impact beam 11 and the door inner panel 16 can be suppressed, the joint strength of the welded portions of both members can be suppressed. Can be suppressed.

According to this embodiment, since the joint strength of the welded portion can be secured, the durability and reliability of the door impact beam mounting structure can be improved.

According to the present embodiment, the tensile strength is 500
Since the door impact beam 11 is integrally formed using a steel plate made of high-strength steel of up to 600 MPa, the integrally formed door impact beam 11 also has excellent tensile strength. You will be able to exert functions more reliably.

According to the present embodiment, in the cleaning process, the bracket portions 13 and 1 of the door impact beam 11 are
Oxides such as rust and oils and fats on the coated surface of No. 4 can be removed, so that the coated surface of the bracket portions 13 and 14 can be coated in a good state.

According to the present embodiment, the coating surface of the bracket portions 13 and 14 of the door impact beam 11 is cleaned, and the coating layer 21 is formed on the bracket portions 13 and 14 to protect the coating surface. Thus, the painted surfaces of the bracket portions 13 and 14 can be made less likely to corrode.

According to the present embodiment, since the coating layer 21 is formed only on the welded surfaces of the bracket portions 13 and 14 of the door impact beam 11, the increase in manufacturing cost can be suppressed as much as possible.

In this embodiment, as the conductive paint,
It was decided to use a binder provided with an epoxy ester resin and a conductive filler made of zinc scattered in the binder. Since the coating layer 21 made of this conductive paint is excellent in weldability, rust prevention and weather resistance, the coating layer 21 is used for the bracket portions 13 and 14 of the door impact beam 11 and the door inner panel 16. Even if spot welding is performed with the film interposed, it is possible to reliably exhibit the weldability, rust prevention and weather resistance of the coating layer 21. Therefore, the mounting structure of the door impact beam can be maintained in a stable state for a long period of time, so that the durability and reliability of the mounting structure of the door impact beam can be further improved.

According to the present embodiment, since the conductive paint is made of a one-component type conductive paint, the conductive paint is convenient to handle during the painting process and has good workability. .

According to the present embodiment, the cleaning process, the painting process, and the welding process are performed in order to prevent the welded portion between the bracket portions 13 and 14 of the door impact beam 11 and the door inner panel 16. It is possible to obtain a door impact beam mounting structure with excellent rusting properties.

The above embodiment can be modified and implemented as follows.

In the above-described embodiment, the door impact beam attachment structure is adopted as the vehicle reinforcement member attachment structure, but the invention is not limited to the door impact beam attachment structure.

For example, as shown in FIG. 5, as a mounting structure for a vehicle reinforcing member, a door inner reinforcement 51 (vehicle reinforcing member) is mounted on the upper side of a door inner panel 16 (counterpart member) by spot welding. A door inner reinforcement attachment structure may be adopted. In this case, similarly to the above-described embodiment, the plating layer 15 is formed on the surface of the door inner panel 16 inside the door 17, and the coating layer 21 is formed between the door inner reinforcement 51 and the door inner panel 15. And plating layer 1
The door inner reinforcement 51 is attached to the door inner panel 16 by spot welding in a state where 5 is interposed.

Further, as shown in FIG. 6, as the mounting structure of the vehicle reinforcing member, the center pillar 61 (vehicle reinforcing member) is mounted to the roof side 62 (counter member) and the side sill 63 (counter member) by spot welding. A center pillar mounting structure may be adopted. In this case, the plating layer 15 may or may not be formed on the surfaces of the roof side 62 and the side sill 63. Further, although not shown, a mounting structure of a bumper reinforcement (vehicle reinforcing member) or the like may be adopted as the mounting structure of the vehicle reinforcing member.

In the above-mentioned embodiment, the door impact beam 11 is integrally formed by performing the hot working and the quenching treatment. However, for example, the door impact beam 11 is integrally formed only by the cold working or the door impact beam is Further, the door impact beam may be manufactured by further subjecting the steel sheet to a quenching treatment or subjecting a steel sheet to a hot working treatment only. In short, any processing or treatment may be performed as long as the door impact beam is integrally formed from a steel plate.

In the above-described embodiment, the cleaning process is performed before the coating process, but the cleaning process may be omitted.

In the above-described embodiment, the conductive paint provided with the binder made of the epoxy ester resin and the conductive filler made of zinc is used, but the combination is particularly limited to the combination of the epoxy ester resin and zinc. It is not something that will be done. For example, as a binder, an epoxy resin other than an epoxy ester resin, a phenol resin,
Silicon resin, vinyl resin, drying oil, acrylic resin, alkyd resin, urethane resin and other resin materials and rubber materials are used, and as conductive fillers, gold, silver, copper, nickel,
A metal such as aluminum, a metal oxide such as silver oxide, tin oxide, antimony oxide, carbon black, graphite, silver nitrate, or the like may be used.

In the above embodiment, the coating layer 21 is provided only on the bracket portions 13 and 14 of the door impact beam 11.
However, the coating layer may be formed on the portions other than the bracket portions 13 and 14.

In the above embodiment, the plating layer 15 was formed on the surface of the door inner panel 16, but the plating layer 15
May be omitted.

In the above embodiment, the bracket portion 1
Although airless spray coating was used as a coating method for coating the conductive coating on the coating surface (contact surface) of Nos. 3 and 14, for example, brush coating or air spray coating may be used, and it is particularly limited to airless spray coating. Not something.

In the above embodiment, the tensile strength is 500 to
Although a steel plate made of high-strength steel of 600 MPa is used, other high-strength steel, high-strength steel, super-strong steel, or the like may be used. In short, any material may be used as long as it is steel.

Besides, the technical idea which is not described in each claim of the claims and which is grasped from the above-described embodiment and the like will be described below together with the effect thereof.

(A) The vehicle reinforcing member is a door inner reinforcement, and the mating member is a door inner panel having a plated layer formed on a surface thereof. The mounting structure for a vehicle reinforcing member according to any one of claims.

When constituted in this way, in addition to the effects of the invention described in claims 1, 2 and 3, the door inner reinforcement and the door inner panel are two layers of a coating layer and a plating layer. Since it is attached by spot welding in the state of being inserted through, the corrosion of the welded part of the door inner reinforcement and the door inner panel is surely suppressed, and the decrease of the joint strength at the welded part of both members is further ensured. Can be suppressed.

(B) The vehicle reinforcing member is a center pillar, and the mating members are a roof side and a side sill.
The mounting structure for a vehicle reinforcing member according to any one of the above.

According to this structure, in addition to the effects of the first, second and third aspects of the present invention, spot welding is performed with the center pillar and the roof side and the side sill with the coating layer interposed therebetween. Since it is attached by, the corrosion of the welded portions of the center pillar and the roof side and the side sill can be suppressed, and the reduction of the joint strength at the welded portions of both members can be suppressed.

(C) The material of the steel plate is 0.18 to
0.25 wt% C, 0.15-0.35 wt% S
i, 1.15 to 1.40 wt% Mn, 0.15 to 0.
25 wt% Cr, 0.01 to 0.03 wt% Ti,
A high-strength steel comprising 0.0005 to 0.0025% by weight of B, 0.03% by weight or less of P, 0.01% by weight or less of S, and the balance being Fe and inevitable impurities. The mounting structure for a vehicle reinforcing member according to 1.

With this structure, in addition to the effect of the invention described in claim 1, the tensile strength is 500 to 600 MPa.
By subjecting a steel sheet having the above-mentioned properties to cold working, hot working, quenching, or the like, a door impact beam having a tensile strength of at least 500 MPa or more (the upper limit value is about 1500 MPa) can be obtained. Therefore, the function as the vehicle reinforcing member can be more reliably exhibited.

(D) The vehicle reinforcing member according to any one of claims 1 to 4, wherein the vehicle reinforcing member is subjected to heat treatment such as hot working or quenching. Mounting structure.

According to this structure, in addition to the effects of the invention described in claim 1, claim 2, claim 3, and claim 4,
The function as a vehicle reinforcing member can be sufficiently exerted.

[0078]

According to the invention described in claim 1, it is possible to suppress the corrosion at the welded portion between the vehicle reinforcing member and the mating member, and to suppress the decrease in the joint strength at the welded portion. Further, spot welding can be performed in a good condition at the welded portion between the vehicle reinforcing member and the mating member, and the joint strength at the welded portion between the vehicle reinforcing member and the mating member can be secured. Furthermore, since the durability and reliability of the mounting structure of the vehicle reinforcing member can be improved, the function of the vehicle reinforcing member can be fully exerted.

According to the invention of claim 2, claim 1
In addition to the effects of the invention described in 1., since a steel plate made of any one of high-strength steel, high-strength steel and super-strength steel has excellent tensile strength, a vehicle integrally formed from the steel plate The reinforcing member for vehicle also has excellent tensile strength, and the function as the reinforcing member for vehicle can be more reliably exhibited.

According to the invention described in claim 3, in addition to the effects of the invention described in claims 1 and 2, it is possible to surely exhibit the weldability, rust prevention and weather resistance of the coating layer. You can Therefore, since the mounting structure of the vehicle reinforcing member can be maintained in a stable state for a long period of time, the durability and reliability of the mounting structure of the vehicle reinforcing member can be further improved.

According to the invention of claim 4, in addition to the effects of the inventions of claim 1, claim 2, and claim 3,
Corrosion of the welded portion between the bracket portion of the door impact beam and the door inner panel can be reliably suppressed, and the joint strength of the welded portions of both members can be more reliably ensured. Further, since the coating film layer is formed only on the bracket portion of the door impact beam, increase in manufacturing cost can be suppressed as much as possible.

According to the invention described in claim 5, by carrying out the coating step and the welding step in order, it is possible to obtain the mounting structure of the vehicle reinforcing member having the effect of the invention described in claim 1. it can.

According to the invention of claim 6, claim 5
In addition to the effects of the invention described in (1), it is possible to remove oxides such as rust and oils and fats on the coated surface of the vehicle reinforcing member by the cleaning process, so that the coated surface of the vehicle reinforcing member should be coated in a good condition You can In addition, since the coating surface is protected by forming a coating layer on the coated surface of the vehicle reinforcing member in a clean state, it is possible to prevent the coated surface of the vehicle reinforcing member from corroding.

[Brief description of drawings]

FIG. 1 is a perspective view showing a door impact beam of the present embodiment.

FIG. 2 is a front view showing a state in which a door impact beam is attached to a door inner panel inside the door.

FIG. 3 is a cross-sectional view schematically showing a door impact beam mounting structure according to a conventional technique.

FIG. 4 is a sectional view schematically showing a door impact beam attachment structure according to the present embodiment.

FIG. 5 is a front view schematically showing a state in which a door inner reinforcement is attached to a door inner panel inside a door in another embodiment.

FIG. 6 is a front view schematically showing a state where center pillars are attached to a roof side and a side sill in another embodiment.

FIG. 7 is a perspective view showing a door impact beam according to another related art.

[Explanation of symbols]

11 door impact beam 12 Main body 13,14 Bracket part 15 plating layer 16 door inner panel 17 doors 21 coating layer 22 Nuggets 51 Door Inner Reinforcement 61 center pillar 62 roof side 63 side sill

Claims (6)

[Claims] 1. A reinforcing member for a vehicle integrally formed from a steel plate so as to have a predetermined shape and a mating member made of metal, and a conductive paint is provided between the reinforcing member for the vehicle and the mating member. An attachment structure for a vehicle reinforcement member, characterized in that the vehicle reinforcement member is attached to the mating member by spot welding with a coating layer interposed. 2. The mounting structure for a vehicle reinforcing member according to claim 1, wherein the steel plate is made of any one material of high-strength steel, high-strength steel, and ultra-high-strength steel. 3. The coating film layer is made of a conductive coating material including a binder made of an epoxy resin and a conductive filler made of zinc dispersed in the binder. The mounting structure for a vehicle reinforcing member according to item 2. 4. The vehicle reinforcing member is a door impact beam, the mating member is a door inner panel having a plated layer formed on the surface thereof, and bracket portions integrally formed at both ends of the door impact beam. The coating film layer is formed only on the inner surface of the door inner panel, and the bracket portion is attached to the door inner panel by spot welding with the coating film layer and the plating layer interposed therebetween.
4. The mounting structure for a vehicle reinforcing member according to claim 3. 5. A coating layer is formed by coating a conductive coating material on the contact surface of a vehicle reinforcing member integrally formed from a steel plate so as to have a predetermined shape and a metallic counterpart member on the vehicle reinforcing member side. A method for mounting a vehicle reinforcing member, which comprises sequentially performing a coating step of forming and a welding step of mounting the vehicle reinforcing member to the mating member by spot welding while interposing the coating layer. 6. The mounting of a vehicle reinforcing member according to claim 5, wherein a cleaning step of cleaning a coated surface of the vehicle reinforcing member by sand blasting or shot blasting is performed before the coating step is performed. Method.