JP2002219570A - Outer shell unit and welding method therefor - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide a welding method for an outer shell unit, high in productivity. SOLUTION: In the welding method for the outer shell unit 10 provided with a cylindrical outer shell 3 with a damping force generation mechanism, and a knuckle bracket (suspending part) 7 to be welded to the outer shell 3, a torch 61 of an arc welding machine is arranged to be close to the welding position of the side part of the outer shell 3 and the knuckle bracket 7, and the outer shell unit 10 is rotated so that the welding position opposing to the torch 61 goes up to weld the knuckle bracket 7 to the outer shell 10.

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to an outer shell unit for suspending a vehicle and an improvement in a method for welding the outer shell unit.

[0002]

2. Description of the Related Art A strut type shock absorber functions as a structural member for positioning a wheel as a part of a suspension member in addition to an original function of generating a damping force.

FIGS. 8 and 9 show an outer shell unit 10 constituting a strut type shock absorber 1. FIG.
A conventional method of welding a spring guide 6 and a knuckle bracket 7 to a cylindrical outer shell 3 is shown.

As shown in FIGS. 8 (a) and 8 (b), when welding the upper end 7e of the knuckle bracket 7 to the outer shell 3, the outer shell 3 is rotated about a central axis O which is disposed substantially vertically. And the torch 61 of the arc welding machine is downwardly welded to the corner between the outer peripheral surface 3a of the outer shell 3 and the upper end 7e of the knuckle bracket 7 by a so-called downward welding method. The shape of this welded portion is an overlapped shape having a portion of a thin wall.

As shown in FIGS. 9A and 9B, a lower end 7f of the knuckle bracket 7 and a lower cap 17 are provided.
Is welded over the entire circumference of the outer shell 3, the outer shell 3 is rotated about a central axis O inclined 60 ° with respect to a horizontal plane, and the torch 61 of the arc welding machine is connected to the lower end 3 b of the outer shell 3. Is welded to a corner between the lower end 7f of the knuckle bracket 7 and the lower cap 17 by a so-called downward welding method. The shape of this welded portion is a special shape with features such as a part of a fillet, overlap, and flare, and requires advanced welding techniques and a long welding time.

As shown in FIGS. 9B and 9C, the lower end 6a of the spring guide 6 is welded to the outer peripheral surface 3a of the outer shell 3 at three places. The shape of this weld is a lap shape.

[0007]

However, in such a conventional method of welding an outer shell unit, an advanced welding technique is used to weld the knuckle bracket 7 and the spring guide 6 to the outer shell 3 in a welding line. , And there is a problem that the welding time becomes long.

The present invention has been made in view of the above problems, and has as its object to provide a method of welding an outer shell unit with high productivity.

[0009]

The first invention is applied to a method of welding an outer shell unit including a cylindrical outer shell having a built-in damping force generating mechanism and a suspension part welded to the outer shell.

Then, the torch of the arc welding machine is disposed close to the welding portion between the side portion of the outer shell and the suspension part, and the outer shell unit is rotated so that the welding portion facing the torch rises to suspend the torch on the outer shell. The feature is that the parts are welded.

According to a second aspect, in the first aspect, a horizontal plane including the center axis O of the outer shell is defined by a horizontal reference plane X.
The point where the extension of the torch intersects with the outer shell unit is defined as a welding point W, and the welding point W is arranged on the horizontal reference plane X or is located above the horizontal reference plane X by a predetermined length Lx. Offset.

In a third aspect based on the second aspect, a vertical plane including the center axis O of the outer shell is defined by a vertical reference plane Y.
Wherein the welding point W is offset from the vertical reference plane Y by a predetermined length Ly, and the welding point W is arranged so that the vertical offset Lx is smaller than the horizontal offset Ly. And

In a fourth aspect based on any one of the first to third aspects, a horizontal plane including the center axis O of the outer shell is defined as a horizontal reference plane X, and the torch is positioned above the horizontal reference plane X. The torch angle θx is set to be in the range of 0 to 30 °.

The fifth invention is applied to an outer shell unit including a cylindrical outer shell having a built-in damping force generating mechanism and a suspension part welded to the outer shell.

[0015] The torch of the arc welding machine is disposed close to the welding portion between the side portion of the outer shell and the suspension part, and the outer shell unit is rotated so that the welding portion facing the torch is raised. The suspension parts are welded to the structure.

[0016]

According to the first and fifth aspects of the present invention,
By balancing the welding speed and the dripping speed of the molten metal, a welding speed higher than the capability of the welding machine obtained by the conventional downward welding method can be obtained, and the productivity of the outer shell unit can be increased.

According to the second aspect of the present invention, by arranging the welding point W on the horizontal reference plane X or above the horizontal reference plane X, gravity works in the direction in which the molten metal adheres to the outer shell. A bead shape is obtained.

According to the third aspect of the present invention, by decreasing the offset amount Lx, the speed at which the molten metal sags becomes faster, so that the welding speed can be increased and the width of the bead can be increased.

According to the fourth aspect, the torch angle θx is 0
By setting the angle in the range of up to 30 °, it is possible to suppress the amount of spatter drop and to effectively suppress insufficient penetration and poor fusion.

[0020]

Embodiments of the present invention will be described below with reference to the accompanying drawings.

As shown in FIG. 1, a strut type shock absorber 1 includes a rod 2 connected to a vehicle body, an outer shell 3 connected to a knuckle (not shown) supporting an axle, and an outer shell 3. A rod guide 9 that slidably supports the rod 2, an inner tube 4 that defines an oil reservoir 18 partially filled with gas inside the outer shell 3, and an inner tube 4 that is connected to the tip of the rod 2. , A piston valve 11 for generating a damping force during an extension stroke.
And a base valve 12 that generates a damping force in a contraction stroke.

In the extension stroke in which the rod 2 moves upward, the upper oil chamber 16 is pressurized, and the hydraulic oil flows into the lower oil chamber 19 through the piston valve 11 to generate a damping force. At this time,
Hydraulic oil corresponding to the retreat of the rod 2 opens the base valve 12 from the oil reservoir 18 and flows into the lower oil chamber 19 with almost no resistance.

During the compression stroke in which the rod 2 moves downward, the hydraulic oil in the lower oil chamber 19 opens the piston valve 11 and flows into the upper oil chamber 16 with almost no resistance. At this time, the hydraulic oil corresponding to the intrusion of the rod 2 flows from the lower oil chamber 19 through the base valve 12 into the oil reservoir 18 to generate a damping force.

The strut type shock absorber 1 includes a spring guide 6 for receiving a lower end of a suspension spring as a suspension part, and a knuckle bracket 7 to which a knuckle is connected, and has a function of positioning wheels as a part of a suspension member.

In the middle of the outer shell 3, an annular stepped portion 35 is formed so as to protrude by bulging. The spring guide 6 is press-fitted into the stepped portion 35 and fixed. Thus, there is no need to weld the spring guide 6 to the outer peripheral surface 3a of the outer shell 3.

The spring guide 6 has a fitting portion 6a fitted to the outer shell 3 and a seat portion 6b for receiving the lower end of the suspension spring, and is integrally formed by press working.

The outer shell 3 has a cylindrical main body 30,
The main body 30 has a bottom 31 for closing the lower end. The bottom 31 of the outer shell 3 is formed integrally with the main body 30 of the outer shell 3 by a plastic working called a closing work.

Since the bottom 31 of the outer shell 3 is sealed by a closing process, it is not necessary to seal the bottom 31 by welding, and high-speed welding can be performed by a vertical downward welding method as described later. Becomes

The bottom 31 is inclined at an angle α with respect to a plane perpendicular to the central axis O, and this angle α is, for example, 30 ° (π
/ 6 rad). A convex portion 34 protruding from the bottom portion 31 to the inside of the outer periphery of the outer shell 3 is formed by a closing process to securely close the bottom portion 31.

On the other hand, the knuckle bracket 7 has a fitting portion 7a fitted to the outer shell 3, a pair of flange portions 7b for holding the knuckle, and a cut-and-raised hose bracket 7
g. Bolt holes 7c and 7d are formed in each flange portion 7b, and a knuckle is fastened to the knuckle bracket 7 through two bolts inserted through the bolt holes 7c and 7d. Each of the bolt holes 7c and 7d is drilled after the knuckle bracket 7 is fixed to the outer shell 3 by welding to ensure dimensional accuracy. The knuckle bracket 7 is of a single-plate type in which no reinforcing member is provided between the flange portions 7b.

The knuckle bracket 7 is the outer shell 3
And then fixed by welding. The lower end of the outer shell 3 is narrowed down by a closing process, so that the outer shell 3 can be smoothly pressed into the outer shell 3.

The single plate type knuckle bracket 7 has upper and lower ends 7e and 7f fixed to the outer shell 3 by welding portions 21 and 22, respectively.

As shown in FIGS. 2 (a), 2 (b) and 2 (c), in forming the upper bracket welded portion 21, the torch 61 of the arc welding machine includes the knuckle and the outer peripheral surface 3a of the outer shell 3. It is directed to a corner between the upper end 7e of the bracket 7 and the welding portion of the present invention, and is welded by a vertical downward welding method. In the vertical downward welding method, the outer shell 3 is rotated around a central axis O disposed substantially horizontally, and the torch 61 of the arc welding machine is directed to the side of the outer shell 3. The rotation direction of the outer shell 3 is set so that the portion of the outer shell 3 facing the torch 61 rises as shown by the arrow in FIG.

A horizontal plane including the center axis O of the outer shell 3 is defined as a horizontal reference plane X. A vertical plane including the center axis O of the outer shell 3 is defined as a vertical reference plane Y. The extension of the torch 61 of the arc welding machine is the outer peripheral surface 3 of the outer shell 3.
The point that intersects with a is referred to as a welding point W.

Whether the welding point W is located on the horizontal reference plane X,
Alternatively, the offset is performed so as to be located above the horizontal reference plane X by a predetermined length Lx. In the present embodiment, the outer diameter of the outer shell 3 is about 45 mm, and the offset amount Lx is set in a range of 0 to 10 mm.

The welding point W has a predetermined length L from the vertical reference plane Y.
offset by y. As a condition of the vertical downward welding method, the welding points W are arranged such that the vertical offset amount Lx is smaller than the horizontal offset amount Ly.

The torch angle θx at which the torch 61 is inclined upward with respect to the horizontal reference plane X is set to be smaller than the torch angle θy at which the torch 61 is inclined with respect to the vertical reference plane Y.
In the present embodiment, the torch angle θx is 0 to 30 ° (0 to 30 °).
π / 6 rad).

As shown in FIGS. 3 (a) and 3 (b), in forming the lower bracket welding portion 21, the torch 61 of the arc welding machine includes the lower end 3b of the outer shell 3 and the lower end of the knuckle bracket 7. It is directed to the corner between 7f and is welded by a vertical downward welding method. In the vertical downward welding method, the outer shell 3 is provided with a central axis O that is disposed substantially horizontally.
Rotate around. The rotation direction of the outer shell 3 is set so that the portion of the outer shell 3 facing the torch 61 rises as indicated by the arrow in FIG.

Whether the welding point W is located on the horizontal reference plane X,
Alternatively, the offset is performed so as to be located above the horizontal reference plane X by a predetermined length Lx. In the present embodiment, the outer diameter of the outer shell 3 is about 45 mm, and the offset amount Lx is set in a range of 0 to 10 mm.

The torch angle θx at which the torch 61 is inclined upward with respect to the horizontal reference plane X is 0 to 15
° (0 to π / 12 rad).

In the vertical downward welding method, the current and voltage of the torch 61 and the outer shell 3 are varied according to the outer diameter of the outer shell 3.
By setting the torch angle θx and the offset amount Lx arbitrarily together with the rotation speed of the welding machine and balancing the welding speed and the dripping speed of the molten metal, the capability of the welding machine obtained by the conventionally used downward welding method is exceeded. The welding speed is obtained.

FIG. 4 shows the relationship between the torch angle θx and the amount of fall of the spatter. An arc force acts on the molten metal as indicated by an arrow in the figure, and the molten metal is pushed forward. For this reason, when the torch angle θx is set to be larger than 30 °, the amount of sputter drop sharply increases.

When the torch angle θx is increased, the bead width is widened and the appearance is good, but insufficient penetration and poor fusion are liable to occur, resulting in a concave bead shape and insufficient strength. Insufficiency of the penetration is caused by the occurrence of an arc on the molten metal due to an excessive lead of the molten metal.

Therefore, the torch angle θx is 0 to 30 °
By setting the amount within the range, the amount of spatter drop can be suppressed, and insufficient penetration and poor fusion can be effectively suppressed.

When the welding point W is disposed below the horizontal reference plane X and the offset amount Lx is set to a negative value, gravity acts in a direction to separate the molten metal from the outer shell 3.
The bead shape deteriorates. By disposing the welding point W above the horizontal reference plane X, a good bead shape can be obtained.

FIG. 5 shows the offset amounts Lx and Ly of the welding point W.
And the general relationship between the bead shape. As the offset amount Lx decreases, the speed at which the molten metal sags increases, and the width of the bead increases. Conversely, as the offset amount Lx increases, the speed at which the molten metal sags decreases, and the width of the bead decreases. At this time, if the rotation speed of the outer shell 3 is increased, the balance with the dripping speed of the molten metal is lost, resulting in poor welding.

Knuckle bracket 7 on outer shell 3
When the outer diameter of the outer shell 3 is larger,
The offset amount Lx of the welding point W with respect to the horizontal reference plane X is set large. In the present embodiment, the outer diameter of the outer shell 3 is about 45 mm, and the offset amount Lx is 0 to 1
By setting the thickness in the range of 0 mm, the dripping speed of the molten metal becomes appropriate, and a good bead shape can be obtained.

As another embodiment, FIG.
(B) As shown in the figure, the knuckle bracket 7 may be of a two-plate type having a tubular shape with the reinforcing member 15 provided between the flange portions 7b. The reinforcing member 15 is fixed between the flange portions 7b, and the knuckle bracket 7
Increase rigidity.

After the knuckle bracket 7 is press-fitted into the outer shell 3, only the lower end 7f is fixed to the outer shell 3 by welding. It is not necessary to fix the upper end 7e of the knuckle bracket 7 to the outer shell 3 by welding.

As shown in FIGS. 6A and 6B, the torch 61 of the arc welding machine is connected to the lower end 3b of the outer shell 3.
And the lower end 7f of the knuckle bracket 7 is directed to the welding portion of the present invention, and is welded by a vertical downward welding method. The vertical downward welding method uses the outer shell 3
Is rotated about a central axis O arranged substantially horizontally. The rotation direction of the outer shell 3 is set so that the portion of the outer shell 3 facing the torch 61 rises as indicated by the arrow in FIG.

Whether the welding point W is located on the horizontal reference plane X,
Alternatively, the offset is performed so as to be located above the horizontal reference plane X by a predetermined length Lx. In the present embodiment, the outer diameter of the outer shell 3 is about 45 mm, and the offset amount Lx is set in a range of 0 to 10 mm.

The torch angle θx at which the torch 61 is inclined upward with respect to the horizontal reference plane X is 0 to 30.
° (0 to π / 6 rad).

In this case, the use of the tubular two-plate knuckle bracket 7 eliminates the need to fix the upper end 7e of the knuckle bracket 7 to the outer shell 3 by welding, thereby shortening the work time required for welding. .

As another embodiment, FIG.
(B), (c) As shown in the figures, the stepped portion 35 formed by bulging on the outer shell 3 may be omitted, and the spring guide 6 may be fixed to the outer peripheral surface 3a of the outer shell 3 by welding. .

After the spring guide 6 is pressed into the outer shell 3, its lower end 6c is fixed to the outer peripheral surface 3a of the outer shell 3 by welding.

For welding between the spring guide 6 and the outer shell 3, the torch 61 of the arc welding machine is directed toward a corner between the lower end 6c of the spring guide 6 and the outer peripheral surface 3a of the outer shell 3, and the outer shell 3 is substantially bent. The rotation is performed around a central axis O that is arranged horizontally. The rotation direction of the outer shell 3 is set so that the portion of the outer shell 3 facing the torch 61 rises as indicated by an arrow in FIG. 7A.

Whether the welding point W is located on the horizontal reference plane X,
Alternatively, the offset is performed so as to be located above the horizontal reference plane X by a predetermined length Lx. In the present embodiment, the outer diameter of the outer shell 3 is about 45 mm, and the offset amount Lx is set in a range of 0 to 10 mm.

The torch angle θx at which the torch 61 is inclined upward with respect to the horizontal reference plane X is 0 to 15
° (0 to π / 12 rad).

It is apparent that the present invention is not limited to the above-described embodiment, and that various changes can be made within the scope of the technical idea.

[Brief description of the drawings]

FIG. 1 is a sectional view of a shock absorber according to an embodiment of the present invention.

FIG. 2 is a view showing a method of high-speed welding the upper end of a knuckle bracket to an outer shell.

FIG. 3 is a view showing a method of high-speed welding the lower end of a knuckle bracket to an outer shell.

FIG. 4 is a view showing the relationship between the torch angle θx and the amount of sputtering drop.

FIG. 5 is a diagram showing a relationship between offset amounts Lx and Ly of a welding point W and a bead shape;

FIG. 6 is a view showing a method of welding a lower end of a knuckle bracket to an outer shell at a high speed in another embodiment.

FIG. 7 is a view showing a method of welding a lower end of a knuckle bracket and a spring guide to an outer shell at a high speed in still another embodiment.

FIG. 8 is a diagram showing a method of high-speed welding the upper end of a knuckle bracket to an outer shell in a conventional example.

FIG. 9 is a view showing a method of high-speed welding the lower end of the knuckle bracket and the spring guide to the outer shell.

[Explanation of symbols]

 DESCRIPTION OF SYMBOLS 1 Shock absorber 3 Outer shell 6 Spring guide (suspension part) 7 Knuckle bracket (suspension part) 10 Outer shell unit 61 Torch

──────────────────────────────────────────────────続 き Continued on the front page (51) Int.Cl. ⁷ Identification symbol FI Theme coat ゛ (Reference) B23P 21/00 303 B23P 21/00 303B B60G 15/06 B60G 15/06 F16F 9/32 F16F 9/54 9 / 54 9/32 B J

Claims (5)

[Claims] 1. A method for welding an outer shell unit comprising: a tubular outer shell having a damping force generating mechanism built therein; and a suspension part welded to the outer shell, wherein a torch of an arc welding machine is connected to a side of the outer shell. An outer member which is disposed close to a welding part of the part and the suspension part, and wherein the outer part is rotated so that a welding part facing the torch is raised, and the suspension part is welded to the outer shell. Shell unit welding method. 2. A horizontal plane including a center axis O of the outer shell is defined as a horizontal reference plane X. A point where an extension of the torch intersects with the outer shell unit is defined as a welding point W. The welding point W is defined as a horizontal reference plane. The method for welding an outer shell unit according to claim 1, wherein the outer shell unit is arranged on X or offset so as to be located above the horizontal reference plane X by a length Lx. 3. A vertical plane including the center axis O of the outer shell is defined as a vertical reference plane Y, the welding point W is offset from the vertical reference plane Y by a length Ly, and a vertical offset amount Lx is set in the horizontal direction. The welding method for an outer shell unit according to claim 2, wherein the welding points (W) are arranged so as to be smaller than the offset amount (Ly). 4. A horizontal plane including the center axis O of the outer shell is defined as a horizontal reference plane X, the torch is defined as a torch angle θx inclined upward with respect to the horizontal reference plane X, and the torch angle θx is defined as 0 to 30. The method for welding an outer shell unit according to any one of claims 1 to 3, wherein the angle is set in a range of °. 5. An outer shell unit comprising: a tubular outer shell having a damping force generating mechanism built therein; and a suspension part welded to the outer shell. A structure in which the suspension component is welded to the outer shell by rotating the outer shell unit so that the welding portion facing the torch ascends is disposed close to a welding portion with a suspension component. Outer shell unit.