JP2000210775A - Ring projection, method of forming the same, and welding method using the same - Google Patents

Abstract

PROBLEM TO BE SOLVED: To perform fusion welding with a good productivity and a stable wide width, and to obtain excellent tensile strength by forming a projection in a ring shape on a flange as one body, and making semicircular the sectional shape of the projection projecting from the surface of the flange. SOLUTION: A ring projection 1 is formed in a ring shape, becoming one body with a flange 2, and is a projection 1 having a semicircular cross-section, which projects from the surface of the flange 2 in the direction perpendicular to the surface of the flange 2 and is used for projection welding. The flange 2 is a part of a first member 3, and is a flat or an about flat doughnut shape disk. The ring projection 1 is a solid one free from a void part in its inside, and is formed in a ring shape on the outer peripheral part of the flange 2. For the forming method for the ring projection 1, an inside part is bent at right angle by a prescribed dimension from the outer edge of the flange 2. The part bent at right angle is further bent by a die having a curved shape groove and a punch, and is formed to a solid semicircular shape by the die having the curved shape groove and the punch.

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

The present invention relates to a ring projection, a method of forming the same, and a welding method using the same.

[0002]

2. Description of the Related Art Japanese Patent Application Laid-Open No. Hei 10-6024 discloses that a projection (projection) having a triangular cross section is formed in a ring shape around the entire outer peripheral end of a flange by bending and crushing the outer peripheral end of the flange. It is disclosed that. FIG.
Shows a projection 100 having a triangular cross section. Then, projection welding is performed using the projection as projection for projection welding. This projection welding is used, for example, for welding a main body of an automobile fuel tank and an inlet member. In this case, both the inlet member and the fuel tank body are made of lead-plated steel plate, and a projection is formed on the flange of the inlet member. The projection is applied to the fuel tank body in a half-split state, and the flange and the fuel tank body are sandwiched between the electrodes. A current is passed through and welding is performed. In the case of a projection having a triangular cross section, as shown in FIG. 8, the portion where the pressing force is large at the front end of the projection comes into pressure contact and the region where the pressing force outside the portion is appropriately small becomes large in heat generation, as shown in FIG. It comes into contact and joins by this fusion welding. The joints are not allowed to leak and require tensile strength. If the current is too low, the joint will fail and peel off,
If it is too high, dust is generated and fuel leakage occurs at the joint.

[0003]

However, the conventional projection welding has the following problems. A projection having a triangular cross section has a large number of molding steps, and thus has low productivity. From an environmental point of view, there is a request to change the lead-plated steel sheet of the fuel tank body to aluminum, zinc, or tin, or tin-zinc plated steel sheet. Since the electric conductivity is high, the current flows too much, the tip of the projection is cut off, fuel leakage easily occurs, and stable projection welding cannot be performed. Therefore, it cannot be changed to aluminum plating or the like. In addition, when the inlet member is also changed to aluminum plating, the slipperiness of the projection on the groove surface of the die at the time of projection molding is reduced, making molding difficult and reducing productivity. Therefore, it is difficult to change to aluminum plating or the like. Since the pressure welding area is located at the center, the fusion welding area becomes narrow, and it is difficult to obtain sufficient tensile strength in the fusion welding area. An object of the present invention is to provide a projection (ring) which has good productivity, enables stable fusion welding with a wide width, and thus easily provides a tensile strength, and enables the plating metal of a plated steel sheet to be changed to a metal other than lead. Projection). Another object of the present invention is to provide a method for forming the projection. Still another object of the present invention is to provide a welding method using the above-mentioned projection.

[0004]

The present invention to achieve the above object is as follows. (1) A ring projection formed integrally with a flange in a ring shape and projecting from the surface of the flange, wherein the cross-sectional shape of the projection before projection welding is semicircular. (2) Assuming that the radius of the semicircular cross-sectional shape of the projection is t, the thickness of the portion of the flange where the projection is not formed is (t−0.1t) to (t +
0.1t). The ring projection according to (1) above. (3) The ring projection according to (1), wherein the material of the flange is a plated steel plate, and the outer surface of the projection is a plated layer. (4) a step of bending the flange so that the first portion closer to the flange end than the bent portion is substantially perpendicular to the second portion farther from the flange end than the bent portion, and between the die having the groove and the punch. Pressing the first part and the second part with each other to further bend the first part toward the side approaching the second part at the bending part, and further to a part on the tip side of the first part. Bending the first portion toward the second portion, and crushing the curved first portion between a die and a punch to form a ring shape integrally with the flange. Forming a projection projecting from the surface of the second portion of the flange and having a semicircular cross-sectional shape before projection welding. (5) A plated steel sheet is formed by projecting a first member having a flange and having a projection formed in a ring shape integrally with the flange on an outer peripheral portion of the flange and projecting from the surface of the flange and having a semicircular cross section. A welding method using ring projection in which projection welding is performed using the projection on the second member made of: (6) The welding method using ring projection according to (5), wherein the second member is a fuel tank main body, and the first member is a fuel tank inlet member. (7) The welding method using ring projection according to (5), wherein the first member is also made of a plated steel plate, and the plating layers of the first member and the second member are plating layers containing no lead. (8) The ring projection according to (5), wherein the first member is also made of a plated steel sheet, and the plating layers of the first member and the second member are layers of aluminum, zinc, or tin, or zinc and tin. Using welding method.

In the ring projection of the above (1), since the projection section is semicircular, the man-hour for forming the tip (several steps required) as in the case of the conventional triangular section is not required. The number of molding steps is reduced by several steps. As a result, productivity is improved. In the case of a projection having a semicircular cross section, the area of the fusion welding area can be widened, the pressing force can be flattened, and stable bonding can be performed. As a result, both the member on which the projection is formed and the mating member to which it is bonded can change the plating from lead to a metal other than lead (eg, aluminum, zinc, tin, tin / zinc, etc.)
It is desirable from the viewpoint of environmental problems. In the ring projection of the above (2), since the radius of the semicircular cross-sectional shape of the projection is (t−0.1t) or more, the joining area is large, sufficient tensile strength is obtained, and (t + 0.1 t)
t) Because of the following, sufficient fusion welding is possible, and peeling is eliminated.
In the ring projection of the above (3), the outer surface of the projection is a plating layer. The metal for this plating may be lead, and metals other than lead (eg, aluminum, zinc,
Tin, tin / zinc, etc.). In the method of forming a ring projection of the above (4), the first portion of the flange is curved and crushed into a semicircular cross-section, so that the subsequent step of forming the tip of the projection is not required. The number of molding steps is reduced as compared with the related art. As a result, productivity is improved. In the welding method using the ring projection of the above (5), since the cross-sectional shape of the projection is semicircular, a large pressurized area, a nearly flat pressure distribution and a stable current density are obtained, and a wide and stable fusion welding is performed. Zone is obtained, and the tensile strength of the joint is also improved. In the welding method using the ring projection of the above (6), the method of the present invention is applied to the projection welding between the fuel tank body for an automobile and the inlet member thereof.
In the welding method using ring projection of the above (7), it is possible to change the plating metal of both members to be joined to a metal other than lead by stabilizing the joining. In the welding method using ring projection of the above (8), aluminum, zinc, tin, and tin / zinc are used as metals other than lead. However, these metals may be pure metals or may contain other elements. For example, aluminum may contain about 10% by weight of silicon.

[0006]

1 and 2 show a ring projection according to an embodiment of the present invention, FIG. 3 shows a method of forming the ring projection, and FIG. 4 shows a welding method using the ring projection. Figure 5
FIG. 6 shows a part manufactured by the method, and FIG.
FIG. 7 shows a comparison of the tensile strength between a part obtained by the method of the embodiment of the present invention and a part obtained by the conventional method, and FIG. 7 shows the fusion welding area of the joint obtained by the method of the embodiment of the present invention. And pressurized distribution.

First, a ring projection according to an embodiment of the present invention will be described with reference to FIGS. The ring projection 1 according to the embodiment of the present invention is formed in a ring shape integrally with the flange 2, and the flange 2 extends from the surface of the flange 2.
Are projections (projections) for projection welding, which project in a direction perpendicular to the surface of the projection. The cross-sectional shape of the projection 1 before the execution of the projection welding is semicircular. Projection 1 is solid and has no cavity inside. The flange 2 is a part of the member 3 and is a flat or almost flat, donut-shaped disk. The ring projection 1 is formed in a ring shape on the outer periphery of the flange 2 to form the outer periphery of the flange 2. By doing so, it is formed integrally with the flange 2.

The radius r of the semicircular cross-sectional shape of the projection 1 is preferably (t) where t is the thickness of the portion of the flange 2 where the projection 1 is not formed.
-0.1t) to (t + 0.1t). The radius of the semicircular cross-sectional shape of the projection 1 is represented by (t-0.
The reason for setting it to 1t) or more is that, when it is set to (t-0.1t) or more, the bonding area becomes large and a sufficient tensile strength can be obtained, and the radius of the semicircular cross-sectional shape of the projection 1 is set to ( (t + 0.1t) or less because (t + 0.1t)
When the thickness is 0.1 t) or less, it is possible to prevent the current density from becoming too small, to perform sufficient fusion welding, and to prevent peeling at the joint after joining. The thickness of the flange 2 is 1 mm, 0.9 mm, 0.8 mm, or the like.

The material of the flange 2 is a plated steel plate, and the projection 1 is formed by bending and crushing the flange 2, so that the outer surface of the projection 1 is formed of a plated layer of the material. The plating metal of the plating layer may be lead (lead is a main component and may include another metal, for example, tin or the like), or may be a metal other than lead. Metals other than lead include aluminum (also referred to as aluminum), zinc, tin, tin / zinc, and the like. These metals may be pure metals or may contain other elements. For example, aluminum may contain about 10% by weight of silicon.

Next, a method of forming a ring projection 1 having a semicircular cross section according to an embodiment of the present invention will be described with reference to FIG. In the method of forming the ring projection 1 according to the embodiment of the present invention, the first portion 4 of the flange 2 closer to the flange end than the bent portion 30 is substantially perpendicular to the second portion 5 farther from the flange end than the bent portion 30. By pressing the first part 4 and the second part 5 between the die 7 and the punch 8 having the groove 6 having a V-shaped or curved groove in cross section. The first part 4 is further bent toward the side approaching the second part 5, and the first part 4 is further curved so that the tip part 9 of the first part 4 is directed toward the second part 5. In the second step, the curved first portion 4 is cut into a groove 10 having a curved cross section.
Squeezed between the die 11 and the punch 12 having
Forming a projection 1 projecting from the surface of the portion 5 and having a semicircular cross-sectional shape before projection welding. After being crushed, the projection 1 has no cavity inside and is solid.

[0011] Ring projection 1 of an embodiment of the present invention
Before the first step, there is a flaring step in which the mandrel 14 is pushed into one end of the pipe 13 to expand the diameter, and a flared portion is pressed by a press machine 15 to form a plane perpendicular to the pipe axis. Press forming the flange 2 extending inward. The material of the pipe 13 is a plated steel plate (including a plated pipe). The plating metal may be lead (lead is a main component and may include another metal, for example, tin or the like), or may be a metal other than lead. Metals other than lead include aluminum (also referred to as aluminum), zinc, tin, tin / zinc, and the like.
These metals may be pure metals or may contain other elements. For example, about 10 for aluminum
It may contain silicon by weight.

Next, a welding method using the ring projection 1 will be described with reference to FIGS. In the welding method using the ring projection according to the embodiment of the present invention, a flange 2 is provided.
A first member 3 having a projection 1 having a semicircular cross-section projecting from the surface of the flange 2 and integrally formed in a ring shape is coated with a plated steel plate (including a molded product thereof).
A projection welding process using the projection 1 to the second member 16 made of

The second member 16 is, for example, a container body of a fuel tank, and the first member 3 is, for example, an inlet member of a fuel tank. The joining is performed when the second member 16 is in a half-split state. The joining is performed by sandwiching the projection portion of the first member 3 and the second member 16 between the lower electrode 17 and the upper electrode 18, and supplying electricity between the electrodes 17 and 18. The current is about 100,000 amps and the energizing time is about 0.33 seconds.

Both the first member 3 and the second member 16 are made of a plated steel plate, and the plating layers of the first member 3 and the second member 16 are desirably lead-free plating layers. However, the first member 3 may be a plated steel sheet of lead, and the second member 16 may be a plated steel sheet of a metal not containing lead.
Both the member 3 and the second member 16 may be lead plated steel sheets. Lead-free plating metals are, for example, aluminum,
Or a layer of zinc, or tin, or zinc and tin. These metals may be pure metals or may contain other elements. For example, aluminum may contain about 10% by weight of silicon.

Next, the operation of the ring projection, its forming method, and the welding method using the same will be described with reference to FIGS. Since the projection 1 has a semi-circular cross section, the number of man-hours for forming a corner (necessary for several steps) as in the case of the conventional triangular cross section is not required, and the number of steps for forming is reduced by several steps as compared with the related art. In the conventional triangular cross section, when the flange end is bent, the outer surface of the projection becomes curved and it is formed into a triangular cross section with corners in several steps, but the projection with the curved outer surface is made semicircular. Since the molding process requires fewer steps, the number of molding steps is reduced by several steps (about 8 steps). As a result, the productivity of the projection 1 having a semicircular cross section is improved as compared with the conventional triangular cross section.

Further, as shown in FIG. 7, when the projection has a semicircular cross section, the contact area can be widened when pressed against the mating member, and the pressing force on the contact surface is flattened. As a result, the electrical resistance of the contact portion is flattened, and stable heat generation and stable fusion welding can be performed. In addition, in the joining of the projections having a semicircular cross section, the pressure contact area (the area where it cannot be confirmed that the joining is performed), which has occurred near the tip of the projection as in the case of the conventional triangular projection, is eliminated, and the entire contact area is reduced. It becomes a fusion welding area (a region where a nugget is formed but joined), and the fusion welding area becomes wider than in the case of a conventional triangular projection, and the tensile strength is improved. FIG. 6 shows the tensile strength of a ring projection welding product (joint between the fuel tank body and the inlet member) obtained by changing the welding current between the round projection (the present invention) and the triangular projection (the conventional). The results of the test are shown. FIG. 6 shows that the example of the present invention can obtain a higher tensile strength and a higher tensile strength from a low welding current region.

Further, the semicircular cross-section projection has a wider projection tip than the triangular projection, and the welding current can be made lower than in the case of the triangular projection. Leakage is eliminated. In the case of a fuel tank for an automobile, since the joint is not allowed to leak, it is desirable to apply the projection 1 of the embodiment of the present invention to the joint of the fuel tank for an automobile.

When the radius r of the semicircular cross-sectional shape of the projection 1 is (t-0.1t) or more, the joining area is increased, sufficient tensile strength is obtained, and (t +
When it is 0.1 t) or less, sufficient fusion welding can be performed, and peeling does not occur.

When both the member 3 on which the projection 1 is formed and the mating member 16 to which it is joined are made of a plated steel plate, the plating metal is changed from lead to a metal other than lead (for example, aluminum, zinc, tin, When it is changed to, for example, aluminum, when it is changed to aluminum, for example, aluminum has a higher electric conductivity than lead, so that a welding current easily flows, and the tip of the projection tends to generate dust. However, in the embodiment of the present invention, As described above, dust generation and burnout at the tip of the projection are eliminated, so that the member 3 on which the projection 1 is formed and the mating member 16 to which the projection 1 is to be bonded are both made of a metal other than lead, such as aluminum or zinc. , Tin, tin / zinc, etc.), which is desirable from the viewpoint of environmental issues. In the case of a triangular projection, the plating metal cannot be changed from lead to aluminum (if changed, dust and leakage will occur).

Ring Projection 1 of Embodiment of the Present Invention
Since the first portion 4 of the flange 2 is curved and crushed into a semicircular cross-section, the subsequent step of forming a projection at the tip of the projection (a plurality of pressing steps) is not required, and As a result, the number of molding steps is reduced as compared with the conventional triangular projection. As a result, productivity is improved. When the flange 2 is a plated steel plate (including a plated pipe), and when the plated metal is lead, since the sliding property with respect to the surface of the groove 6 of the die 7 is good, bending and crushing can be performed smoothly. If it is changed to a metal other than lead, for example, aluminum (containing silicon), the slipperiness decreases with respect to lead. Therefore, in the case of a triangular projection, it is difficult to form a projection. Easier, despite the reduced slipperiness,
Plating metals are metals other than lead (eg, aluminum, zinc,
Tin, tin / zinc, etc.).

In the welding method using the ring projection according to the embodiment of the present invention, since the cross-sectional shape of the projection 1 is semicircular, as shown in FIG.
The contact area of the pressurization with the member 16 is wider than that of the case of the triangular protrusion, a pressure distribution almost flat and a stable current density are obtained, a wide and stable fusion welding area is obtained, and the tensile Strength is also improved. Also, since there is no dust at the tip of the projection as in the case of a triangular projection, no leakage occurs. Therefore, the present invention can be applied to projection welding of a fuel tank for an automobile in which no leakage is allowed. In this case, the fuel tank body becomes the second member 16 and the inlet member becomes the first member 3.

In the welding method using the ring projection according to the embodiment of the present invention, both members to be joined may be plated steel plates by stabilizing the joining. In this case, the plated metal is changed to a metal other than lead. Is possible. Aluminum, zinc, tin, and tin / zinc are used as metals other than lead. However, these metals may be pure metals or may contain other elements. For example, aluminum may contain about 10% by weight of silicon.

[0023]

According to the ring projection of the first aspect, since the projection section is semicircular, the man-hour for forming a corner at the tip is unnecessary as in the case of the conventional triangular section, and the man-hour for forming is smaller than in the conventional case. Is reduced by several steps. As a result, productivity is improved. In the case of a projection having a semicircular cross section, the area of the fusion welding area can be widened, the pressing force can be flattened, and stable bonding can be performed. As a result, both the member on which the projection is formed and the mating member to which it is bonded can change the plating from lead to a metal other than lead,
It is desirable from the viewpoint of environmental problems. According to the ring projection of the second aspect, since the radius of the semicircular cross-sectional shape of the projection is (t-0.1t) or more, the joining area is widened, sufficient tensile strength is obtained, and (t + 0.
Since it is 1t) or less, sufficient fusion welding can be performed, and peeling does not occur. According to the ring projection of the third aspect, the outer surface of the projection is a plating layer. According to the ring projection forming method of the fourth aspect, the first portion of the flange is curved and crushed into a semicircular cross section, so that the subsequent step of forming the tip of the projection is not required, and the portion is accordingly reduced. Thus, the number of molding steps is reduced as compared with the conventional triangular projection. As a result, productivity is improved. According to the welding method using the ring projection according to the fifth aspect, since the cross-sectional shape of the projection is semicircular, the pressing area is wide, a flat pressure distribution and a stable current density are obtained, and a wide and stable fusion is achieved. A contact area is obtained, and the tensile strength of the joint is also improved. According to the welding method using the ring projection of the sixth aspect, the method of the present invention can be applied to the projection welding of the fuel tank body for an automobile and the inlet member thereof. According to the welding method using the ring projection of the seventh aspect, the plating metal of both members to be joined can be changed to a metal other than lead by stabilizing the joining. According to the welding method using the ring projection of claim 8, as the metal other than lead, aluminum, zinc, tin, tin / zinc can be used,
Environmentally desirable.

[Brief description of the drawings]

FIG. 1 is a cross-sectional view of a ring projection according to an embodiment of the present invention.

FIG. 2 is a sectional view of a member having a ring projection according to the embodiment of the present invention.

FIG. 3 is a process diagram of a method for forming a ring projection according to an embodiment of the present invention.

FIG. 4 is a cross-sectional view of the apparatus during execution of the welding method using ring projection according to the embodiment of the present invention.

FIG. 5 is a perspective view of a part welded by a welding method using ring projection according to the embodiment of the present invention.

FIG. 6 is a graph of tensile strength versus welding current of a part welded by a welding method using a ring projection and a part welded by a conventional welding method using a triangular protrusion according to an embodiment of the present invention.

FIG. 7 is a graph showing the tendency of the pressure distribution and the width of the fusion zone in the welding method using the ring projection according to the embodiment of the present invention.

FIG. 8 is a graph showing a distribution of a pressing force and a tendency of a width of a fusion welding area in a conventional welding method using a triangular protrusion.

FIG. 9 is a sectional view of a conventional projection of a triangular projection.

[Explanation of symbols]

 DESCRIPTION OF SYMBOLS 1 Projection 2 Flange 3 1st member 4 1st part 5 2nd part 6 Groove 7 Die 8 Punch 9 Part on the front end side of 1st part 10 Groove 11 Dice 12 Punch 13 Pipe 14 Mandrel 15 Press machine 16th 2 member 17, 18 electrode 30 bent part

Claims (8)

[Claims] 1. A projection formed in a ring shape integrally with a flange and projecting from the surface of the flange, wherein the cross-sectional shape of the projection before the projection welding is a semicircle. 2. The radius of the semicircular cross-sectional shape of the projection is (t−0.1t) to (t−0.1t), where t is the thickness of a portion of the flange where the projection is not formed.
2. The ring projection according to claim 1, wherein (t + 0.1t). 3. The material of the flange is a plated steel plate, and the outer surface of the projection is a plated layer.
Ring projection as described. 4. A step of bending the flange so that a first portion closer to the flange end than the bent portion is substantially perpendicular to a second portion farther from the flange end than the bent portion, a grooved die and a punch. Between the first part and the second part
By pressing the portion, the first portion is bent at the bent portion.
Part is further bent toward the side approaching the second part,
Further bending the first portion so that a tip portion of the first portion faces the second portion; and crushing the curved first portion between a die and a punch. Forming a projection integrally formed on the flange in a ring shape and projecting from the surface of the second portion of the flange and having a semicircular cross-sectional shape before projection welding. 5. A first member having a projection which has a flange and is formed in a ring shape integrally with the flange on an outer peripheral portion of the flange, and has a projection projecting from the surface of the flange and having a semicircular cross section, A welding method using ring projection in which projection welding is performed on the second member made of a plated steel sheet using the projection. 6. The welding method using ring projection according to claim 5, wherein the second member is a container main body of a fuel tank, and the first member is an inlet member of the fuel tank. 7. The first member also comprises a plated steel sheet,
6. The welding method according to claim 5, wherein the plating layers of the first member and the second member are plating layers containing no lead. 8. The first member also comprises a plated steel sheet,
The welding method using ring projection according to claim 5, wherein the plating layers of the first member and the second member are layers of aluminum, zinc, tin, or zinc / tin.