JP2018103224A - Method for processing joint and method for manufacturing tank - Google Patents

Abstract

PROBLEM TO BE SOLVED: To suppress a joint shape failure due to overload of a roller in forming the joint and wear of a tool, provide a high quality tank part to improve productivity and extend a life of the roller.SOLUTION: In a method for processing a joint, a proper groove angle is chosen in accordance with a ratio of a roller diameter to a work diameter for a first roller, and a second roller is formed with a first processing orbit of forming a work on a flange by the processing orbit and a second processing orbit of pressing a flange-like part into the first roller, thereby reducing processing load and acquiring a high quality joint shape.SELECTED DRAWING: Figure 1

Description

  The present invention relates to a method for processing an end portion of a shaft target member, and a method for manufacturing a container that stores a fluid in particular inside by using the end portion processing method.

  As a pressure vessel for storing a fluid therein, one manufactured by a metal thin plate or a composite material is known. Among these, a tank for a hot water storage type hot water heater is often used in which a plurality of members made of stainless steel plates are joined by means such as welding. As a manufacturing method of this type of tank, a cylindrical body is formed by welding two opposite sides after a flat plate is roll-bent-molded. There is a method in which a bowl-shaped part is used as a mirror part, and the peripheral part of the mirror part is welded to the openings at both ends of the body part over the entire circumference. Here, welding over the entire circumference of the opening of the body part and the peripheral part of the mirror part is called circumferential welding, and the joint part of the body part and the mirror part is subjected to spinning processing or the like for circumferential welding. A joint having a L-shaped or Z-shaped cross section is formed (see, for example, Patent Document 1 and Patent Document 3).

  It is desirable to use a butt joint that does not have a gap in order to reduce the thickness and life of the water heater tank. Unless the displacement is strictly controlled, a good butt joint cannot be obtained. In order to obtain a good butt joint by circumferential welding of a water heater tank, it is necessary to strictly control the diameter of the body and the mirror and the dimensions of the joint before welding. In such a spinning forming of a joint, there is known a method in which a processing portion of the member is sandwiched from an inner surface and an outer surface by two rollers while the body portion or the mirror portion is rotated (for example, a shape is formed) Patent Document 2).

JP 2012-148304 A JP 2015-212443 A Japanese Patent Laid-Open No. 4-9276

  By the way, in order to form a Z-shaped joint, the conventional method of sandwiching the end of a cylindrical member using a roller having a Z-shaped cross section and a roller having an acute cross section has a particularly acute cross section. The processing load is concentrated on the tip of the roller, which may cause wear or cracking of the roller. These phenomena become more prominent as the plate thickness increases with a greater processing load.

  On the other hand, when the roundness of the cylindrical member is poor when fitting the Z-shaped joint and the L-shaped joint, the L-shaped joint and the bowl-shaped portion of the Z-shaped joint come into contact with each other in a part of the circumference. The Z-shaped joint or the L-shaped joint may be deformed to deteriorate the close contact state of the joint, which may cause poor circumferential welding.

  The present invention has been made to solve the above problems, and a processing method for forming a joint that prevents wear and breakage of a roller and realizes a smooth fitting, and a joint that realizes a smooth fitting. The purpose of this is to propose a method of manufacturing a tank using

The method for processing a joint according to the present invention includes:
A first roller for forming the workpiece, the first roller for forming the workpiece, and a second roller for forming the workpiece, arranged to be in contact with the inner peripheral surface of the workpiece. Using a roller, a joint processing method for forming a joint on the periphery of the opening end of the workpiece,
A first step of bringing the first roller into contact with the outer peripheral surface of the workpiece;
Moving the second roller from the inside of the inner periphery of the workpiece to the outside of the outer periphery of the workpiece, and a second step of forming a flange portion at the opening end of the workpiece;
A third step in which the second roller moves in the axial direction of the workpiece and cooperates with the first roller to sandwich the flange portion and form a joint;
Is included.

  According to the present invention, it is possible to obtain a joint excellent in fitting workability and adhesion without increasing the load on the roller. In addition, the tank can be made thinner and have a longer life.

6 is a diagram for explaining a joint processing method according to Embodiment 1. FIG. 1 is a schematic diagram illustrating a configuration of a joint machining apparatus according to Embodiment 1. FIG. FIG. 3 is a schematic diagram of a gripping mechanism of the joint machining apparatus according to the first embodiment. FIG. 3 is a side view of a first roller used in the joint processing apparatus according to the first embodiment. It is a figure which shows the relationship between the inclination angle of the rotating shaft of the 1st roller used for the coupling processing apparatus of Embodiment 1, or the 2nd roller, and the bending angle of a coupling. FIG. 5 is a side view of a second roller used in the joint processing apparatus according to the first embodiment. FIG. 3 is a schematic diagram illustrating a joint machining process according to the first embodiment. FIG. 6 is a schematic diagram illustrating a configuration of a joint machining apparatus according to a second embodiment. FIG. 10 is a side view of a first roller used in the joint machining apparatus according to the second embodiment. FIG. 6 is a schematic diagram illustrating a process for manufacturing a joint according to a second embodiment. It is a figure for demonstrating the fitting state of the joint in a conventional method. It is a figure for demonstrating the fitting state of the joint in Embodiment 3. FIG.

Embodiment 1 FIG.
1 shows a side view of a machining tool according to Embodiment 1 of the present invention and a cross-sectional view of a portion to be machined of a cylindrical member. In the first embodiment, the workpiece to be processed is, for example, a part of a tank for a water heater, and the workpiece used here is assumed to be mainly cylindrical, and both ends thereof are open. Pick up a case. In particular, in FIG. 1, the cylindrical workpiece 103 has a cross-sectional shape only in the vicinity of the opening end, and this cross-section is a Z-shaped joint 104 (also referred to as a Z-shaped joint 104 for simplification). This will be described below.
Here, the tank for a water heater is generally manufactured by welding a bowl-shaped member as a lid or bottom to the openings at both ends of a cylindrical member, and the workpiece is a part that becomes the trunk of the tank for the water heater. It is. These workpieces are, for example, stainless steel having a plate thickness of about 0.5 mm to 1.0 mm, and a diameter of about 200 mm to 700 mm. In the case of a cylindrical member, the length is 500mm to 2000m.
m. These dimensions are values determined by the design of the tank, and the invention according to the present embodiment is not limited to these dimensions.

FIG. 2 is a schematic diagram showing a configuration of an apparatus for processing the cylindrical member according to the first embodiment of the present invention. A processing apparatus according to the present embodiment is provided with a gripping mechanism 201 that grips a cylindrical workpiece, a first roller 101 and a second roller 102 that are processing tools for processing the workpiece, and these processing tools are attached. A support mechanism (not shown), a core 205 (a structure for arranging fan-shaped blocks concentrically disposed along the inner surface of a cylindrical workpiece), a driving device 202 for driving the support mechanism, And a driving device 203 that drives the gripping mechanism, and a control unit 204 that operates them at a predetermined position and speed. The gripping mechanism and its driving device 203 and the support mechanism and its driving device 202 are mechanically coupled to each other. Each drive unit is electrically connected to the control unit, and operates the gripping mechanism and the support mechanism at predetermined positions at predetermined speeds by an electrical command signal from the control unit configured by a computer or the like. . In the first embodiment, the case where the outer diameter of the workpiece is 600 mm and the outer diameter of the roller is 120 mm will be described.

First, the gripping mechanism of the apparatus will be described. The gripping mechanism is fixed so that the cylindrical member does not move in the axial direction during processing, and has a function of rotating around an axis (indicated by a one-dot chain line in the drawing). As shown in FIG. 3, the gripping mechanism is arranged rotationally symmetrically about this axis, and supports a fan-shaped block 206 that can move radially about the axis that is the center of rotation, and the block. It is comprised by the part to drive.
In FIG. 3A, the support member 301 of the sector block 206 moves up and down by the movement of the conical block 302 in the axial direction. For example, when the sector block 206 is brought into contact with the cylindrical workpiece 103, the conical block 302 is moved leftward in FIG. 3A (see FIG. 3C).

  In FIG. 3, the sector block is drawn in four divisions, but is not necessarily limited to four divisions. The movement of the gripping mechanism is initially shifted toward the center of rotation so that the sector block is within a radius smaller than the inner diameter of the cylindrical workpiece, and is inserted into the cylindrical workpiece in that state (FIG. 3A). (Refer FIG.3 (b)). Next, as shown in FIG. 3C, when the conical block 302 moves in the direction of arrow A, the sector block 206 moves in the direction of arrow B, that is, radially outward inside the cylindrical workpiece. The inner surface of the cylindrical workpiece 103 and the outer surface of the sector block 206 come into contact with each other (see FIG. 3D).

  Furthermore, if the sector block is moved radially outward within the range in which the cylindrical workpiece is not plastically deformed, a frictional force is generated between the surface of the sector block and the contact surface of the cylindrical workpiece due to the circumferential tension of the cylindrical workpiece. The cylindrical work and the fan block are fixed. However, the gripping mechanism is an example of the present embodiment, and the present embodiment is not limited by these gripping methods and gripping means.

  Next, the processing tool will be described. The processing tool includes a first roller that abuts on the outer surface of the workpiece and a second roller that abuts on the inner surface of the workpiece. The first roller and the second roller are attached to a support mechanism coupled to a drive device that operates independently, and can move independently in a radial direction and an axial direction with respect to the workpiece as long as they do not interfere with each other. it can. It is desirable that the rotation axis of the workpiece, the rotation axis of the first roller, and the rotation axis of the second roller are all on the same plane from the viewpoint of improving processing accuracy (dimensional accuracy).

FIG. 4 shows a side view of the first roller. The first roller is fixed to the rotating shaft 402 via a bearing, and can be freely rotated by an external force in the circumferential direction. The rotation axis of the first roller is inclined by a predetermined angle θ _{1 with} respect to the rotation axis of the cylindrical workpiece. In the vicinity of the outer periphery of the roller, a groove 401 that is a female shape when machining a cylindrical workpiece, for example, is recessed in a triangular shape, is formed. The outside of the Z-shaped joint formed on the cylindrical workpiece is formed along this groove.

式（１）において、Δは正の微小量である（具体的には、Δはｒによって定まる量であって、Δ＜ｒ／１００を満たす微小量）。図５に、式（１）から求めた傾斜角θ₁におけるθ₂の最小角度の一例を示す。 Inclination angle theta ₁ formed by the rotation axis of the rotary shaft and the first roller of the cylindrical member, the bending angle of the joint to be formed by the first roller and theta _2, for example, _{θ 1 = 30 °, θ 2} = 65 °. These optimum angles are related to the ratio of the outer diameter R of the workpiece and the outer diameter r of the first roller, and are expressed by the equation (1).

In Expression (1), Δ is a positive minute amount (specifically, Δ is an amount determined by r and satisfies Δ <r / 100). FIG. 5 shows an example of the minimum angle of θ _{2 at} the inclination angle θ ₁ obtained from the equation (1).

From this figure, when θ ₂ is not sufficiently large with respect to the tilt angle θ _{1 of the} shaft, that is, the minimum value of θ ₂ is determined with respect to the tilt angle θ _{1 of the} shaft from Equation (1). If the θ ₂ is smaller, not only can the outer circumference of the roller interfere with the joint being processed or the processed joint, and the desired joint shape cannot be formed, but the roller outer periphery may be overloaded, resulting in damage to the roller. I know that there is.

  As described above, by setting the inclination angle formed by the rotating shaft of the cylindrical member and the rotating shaft of the first roller, and the bending angle of the joint formed by the first roller so as to satisfy Equation (1) Since interference between the joint in the middle of molding and the roller tip is reduced, there is an effect that the processing load of the roller is reduced, the tool is less worn and damaged, and the tool life can be extended. Moreover, since excessive friction can be reduced also with respect to a joint, a good-quality joint shape can be obtained.

FIG. 6 shows a side view of the second roller. The second roller is fixed to the rotary shaft 601 via a bearing, and can be freely rotated by an external force in the circumferential direction. The rotation axis of the second roller is inclined by a predetermined angle θ _{3 with} respect to the rotation axis of the cylindrical workpiece. In the vicinity of the outer periphery of the roller, a slope 602 is formed so as to be a male shape when processing a cylindrical workpiece.

Also in this case, as in the case of the first roller, the optimum angle for the angle θ ₃ and the joint bending angle θ ₂ is expressed by the following equation (2). Here, as the specific values of the angles θ ₃ and θ ₂ , θ ₃ and θ ₂ may be considered by replacing θ ₁ described above with θ ₃ . R is the same as described in the above formula (1). Here, r ₂ is the outer diameter of the second roller, and Δ is a positive minute amount determined by r ₂ (specifically, Δ is an amount determined by r ₂ , and Δ <r ₂ / 100).

As described above, by setting the angle θ _{3 with} respect to the rotation axis of the cylindrical workpiece and the bending angle θ _{2 of the} joint to satisfy the expression (2), the interference between the joint during molding and the roller tip is reduced. Therefore, there is an effect that the processing load on the roller is reduced, the tool is less worn or damaged, and the tool life can be extended. Moreover, since excessive friction can be reduced also with respect to a joint, a good-quality joint shape can be obtained.

  The inner side of the Z-shaped joint formed on the cylindrical workpiece is formed along the vicinity of the outer periphery of the second roller. The rotating shaft of the second roller is attached to an arm that supports the roller, and the arm can be moved to a predetermined position with respect to the radial direction and the axial direction of the workpiece by a driving device. The driving device is electrically connected to a control unit configured by a computer or the like, and is controlled by an electrical command signal from the control unit.

FIG. 7 shows the processing steps according to Embodiment 1 of the present invention. The first roller that contacts the outer surface of the workpiece in the first step (see FIG. 7A) is disposed so as to contact the other end side by a predetermined length from the opening end of the workpiece. At this time, on the inner surface side of the workpiece with the first roller and the workpiece interposed therebetween, a jig 205 serving as a core is disposed separately from the gripping mechanism and is in contact with the inner surface of the workpiece.

  The jig rotates with the workpiece and the gripping mechanism when they rotate. Furthermore, the rotation of the workpiece is preferably started after the first roller comes into contact with the workpiece. This is because it is possible to prevent the outer surface of the work from being scratched by the slip of the first roller.

The workpiece may start rotating at a low speed with the first roller and the core jig in contact with each other, gradually increase the rotational speed, for example, rotate at a constant speed of 100 to 300 rpm. desirable. Needless to say, when the rotation speed is slow, the production tact is slowed and the productivity is deteriorated. When the rotation is stopped, the workpiece may slip with the gripping mechanism due to inertia, and the inner surface of the workpiece may be scratched. Therefore, the workpiece needs to be rotated at a predetermined rotation speed. That is, since the rotation speed is determined from the productivity and the rigidity of the apparatus and the work related to the resonance frequency of the apparatus and the work, the present embodiment is not limited to the rotation speed.

  On the other hand, the second roller that comes into contact with the inner surface of the workpiece is disposed so as to contact the other end side by a predetermined length from the opening end of the workpiece. In the second step (see FIG. 7B), from the point in time when the workpiece has reached a predetermined rotational speed, the second roller has an arrow shown in the drawing so that the opening end is bent outward in the radial direction of the workpiece. It moves to a D direction and the flange part 701 which is a flange-shaped part is shape | molded in a workpiece | work opening end.

  Next, in the third step (see FIG. 7C), the second roller moves so as to contact the inside by a predetermined length from the front end of the flange, and further in the axial direction (the arrow shown in the figure). E direction) toward the first roller, the flange portion is shaped so as to follow the groove shape of the first roller.

By processing in this way, there is a remarkable effect that it is possible to suppress the thinning of the joint portion and to reduce the processing load on the roller.
In this embodiment, a Z-shaped joint is formed on the open end of the cylindrical workpiece (the axial length of the open end is about 1/200 to 1/300 of the total axial length). As described above, a Z-shaped joint may be processed at the open end of the bowl-shaped workpiece.

  As described above, in the invention of the first embodiment, the Z-shape is formed on the opening end of the workpiece through the flange-shaped forming shape in the middle, so that the vicinity of the opening of the workpiece is changed from the cylindrical shape to the vicinity of the opening of the first roller. Since the processing load is less than that of pressing directly into the groove shape, there is an effect that the tool is less worn and damaged, and the tool life can be extended. Moreover, since thinning of the joint can be suppressed, a highly accurate joint shape can be obtained.

Embodiment 2. FIG.
In the second embodiment, a case where a joint 1002 having an L-shaped cross section is formed on the peripheral edge of the opening of the bowl-shaped workpiece will be described. In the present embodiment, the workpiece to be processed is, for example, a part of a tank for a water heater, and a flat plate is previously formed into a bowl shape by pressing such as deep drawing or overhanging or spinning processing such as spatula drawing. It has been done. A water heater tank is generally manufactured by welding a bowl-shaped member called a mirror part (end plate) as a lid or bottom to the open end of a cylindrical member, and the bowl-shaped workpiece is a lid or bottom of a tank for a water heater. It is a partial product.

  These bowl-shaped workpieces are, for example, stainless steel having a plate thickness of about 0.5 mm to 1.0 mm, a diameter of about 200 mm to 700 mm, and the depth of the bowl-shaped workpiece is about 200 mm to 400 mm. These dimensions are values determined by the design of the tank, and the present embodiment is not limited to these dimensions.

  FIG. 8 is a schematic diagram showing a configuration of an apparatus for processing the bowl-shaped workpiece 803 according to the second embodiment of the present invention. The processing apparatus according to the present embodiment includes a gripping mechanism 804 that grips the saddle-shaped workpiece 803, a first roller 801 and a second roller 802 that are processing tools for processing the saddle-shaped workpiece 803, and a gripping mechanism 804. Drive device 203, a drive device 202 that drives the machining tool, and a control unit 204 that operates these at a predetermined position and speed.

  Next, the gripping mechanism 804 of the apparatus will be described. The gripping mechanism has a function of fixing the bowl-shaped workpiece so as not to move in the direction of the rotation axis during processing and rotating about the axis. When the workpiece shape is a bowl shape, the gripping mechanism 804 includes a hemispherical jig 805 that contacts the inner surface of the workpiece and a fixing jig 806 that contacts the outer surface of the workpiece, as shown in FIG.

  The movement of the gripping mechanism is initially arranged such that the hemispherical jig 805 contacts the inner surface of the bowl-shaped workpiece. Next, pressure is applied by the fixing jig 806 that contacts the outer surface of the bowl-shaped workpiece so that the bowl-shaped workpiece is in close contact with the hemispherical jig. The saddle-shaped workpiece is fixed so as to be rotatable integrally by the frictional force between the inner surface of the saddle-shaped workpiece and the hemispherical jig and the frictional force between the outer surface of the saddle-shaped workpiece and the fixing jig. The gripping mechanism is an example of the present embodiment, and the invention according to the present embodiment is not limited to these gripping methods and gripping means.

  Next, the processing tool will be described. The processing tool includes a first roller 801 that contacts the outer surface of the bowl-shaped workpiece and a second roller 802 that contacts the inner surface of the bowl-shaped workpiece. The first roller and the second roller are attached to a support mechanism coupled to a drive device that operates independently, and move independently in a radial direction and an axial direction with respect to the bowl-shaped workpiece within a range that does not interfere with each other. can do. It is desirable that the rotary shaft of the bowl-shaped workpiece, the rotary shaft of the first roller, and the rotary shaft of the second roller are all on the same plane.

FIG. 9 shows a side view of the first roller in Embodiment 2 of the present invention. The first roller is fixed to the rotating shaft 901 via a bearing, and can be freely rotated by an external force in the circumferential direction. The rotation axis of the first roller is inclined by a predetermined angle θ _{1 with} respect to the rotation axis of the cylindrical workpiece. On the outer periphery of the roller, an inclined surface 902 that is a female shape when an L-shaped joint is formed is formed. The outside of the L-shaped joint formed on the cylindrical workpiece is formed along this slope.

For example, θ ₁ = 30 ° and θ ₄ = 80 ° when the inclination angle formed by the rotary shaft of the bowl-shaped workpiece and the rotary shaft of the first roller is θ ₁ and the bending angle of the L-shaped joint is θ ₄ . These optimum angles are related to the ratio between the outer diameter R of the workpiece and the outer diameter r of the first roller, and are expressed by the following equation (3) using a small amount Δ similar to the equation (1). Is done. An example of the minimum angle of θ _{4 at} the inclination angle θ ₁ can be seen in the same manner as in the first embodiment by replacing θ ₂ with θ ₄ in FIG.

From FIG. 5, when θ ₄ is not a sufficiently large value with respect to the tilt angle θ _{1 of the} shaft, that is, the equation (3)
Since the minimum value of θ ₄ is determined with respect to the shaft inclination angle θ ₁ , if θ ₄ is smaller than the minimum value, the outer circumference of the roller interferes with the joint being processed or the processed joint, and the desired joint shape It can be seen that not only can not be molded, but there is a risk of overloading the roller outer periphery and causing damage to the roller.

As described above, by setting the shaft inclination angle θ ₁ and the bending angle θ ₄ of the L-shaped joint to satisfy Expression (3), the interference between the joint in the middle of molding and the roller tip is reduced. Therefore, there is an effect that the processing load of the roller is reduced, the tool is less worn or damaged, and the tool life can be extended. Moreover, since excessive friction can be reduced also with respect to a joint, a good-quality joint shape can be obtained.

  FIG. 10 shows a method of processing a cylindrical member in the second embodiment of the present invention. In the present embodiment, the bowl-shaped workpiece may not be on the plane perpendicular to the rotation axis, depending on the forming method such as deep drawing or spatula drawing. In such a case, it is desirable that the opening end circumference is formed by a shearing process or a cutting process so that the entire circumference of the opening end is aligned on a plane orthogonal to the rotation axis in the step before forming the joint.

In the first step of forming the joint in the second embodiment of the present invention (see FIG. 10A), the first roller 801 that comes into contact with the outer surface of the workpiece after shaping the opening end is: It is a position in contact with the outer surface (upper side surface shown in the figure) of the bowl-shaped workpiece, and is arranged at a position separated from the opening end of the workpiece by a predetermined length. It is desirable that the workpiece starts rotating from a low speed and gradually increases in rotational speed with the first roller in contact with the first roller, for example, rotating at a constant speed of 100 to 300 rpm.

  Needless to say, when the rotational speed is slow, the production tact is slowed and the productivity is deteriorated. When the rotation is stopped, the workpiece slips between the workpiece and the gripping mechanism due to inertia, which may cause scratches on the inner surface of the workpiece. Therefore, the workpiece needs to be rotated at a predetermined rotation speed. That is, the rotation speed is determined from the rigidity of the apparatus and the work related to the productivity and the resonance frequency of the apparatus and the work. Therefore, the invention according to the present embodiment is not limited to the rotation speed.

  Next, in the second step (see FIG. 10B), the second roller 802 that comes into contact with the workpiece from the inner surface of the bowl-shaped workpiece is a position that comes into contact with the inner surface of the bowl-shaped workpiece, The second roller is disposed at a position separated by a predetermined length from the opening end, and the second roller bends the opening end radially outward (in the direction of the arrow in the figure) when the workpiece reaches a predetermined rotation speed. The flange portion 1001 is formed at the workpiece opening end.

  At this time, it is desirable that the minimum gap between the first roller and the second roller is secured at least a distance greater than the plate thickness of the workpiece. By setting the gap to be equal to or greater than the plate thickness, the processing load can be reduced.

Next, in the third step (see FIG. 10C), the second roller moves so as to contact the inside of the flange tip by a predetermined length, and further moves to the first roller in the rotational axis direction. By moving in the direction, the flange portion is pressed against the first roller, and is formed into a shape along the first roller.
By processing as described above, there is a remarkable effect that local thinning at the base of the joint portion can be suppressed and the processing load on the roller can be reduced.

Embodiment 3 FIG.
In the third embodiment of the present invention, the fitting of members having the joints molded in the first or second embodiment will be described.
Conventionally, in the manufacturing method of a tank manufactured by welding after combining an L-shaped joint and a Z-shaped joint, the slope of the L-shaped joint has been formed to be inclined toward the Z-shaped joint. As shown in FIG. 11, when fitting workpieces, there is a possibility that the joint 110 may come into contact with the flange portion 1101 of the Z-shaped joint, or the joint may be deformed or the L-shaped joint may come off to the outside.

In Embodiment 3 of the present invention, as shown in FIG. 12, the L-shaped joint 1201 is formed so as to be inclined to the side opposite to the Z-shaped joint 1202 (the bending angle θ with respect to the root of the joint in the figure). _2b is 90 ° or less), the L-shaped joint easily fits inward along the slope even if it contacts the flange portion 1101 of the Z-shaped joint, and the fitting workability is excellent. There is an effect that it is easy to obtain a good adhesion state of the joint base. In this case, bending angle theta _2b against the root of the bending angle theta _2a and L-shaped joint for the root portion of the Z-shaped joints, need not be identical. A region P surrounded by a dotted line is a region where the root portion of the Z-shaped joint and the root portion of the L-shaped joint are in close contact.

  As described above, according to the tank manufacturing method of the third embodiment, the slope of the L-shaped joint is tapered, and can be easily inserted into the Z-shaped joint. It is excellent in work fitting workability, and it is possible to obtain high-quality joint adhesion accuracy. It should be noted that the present invention can be freely combined with each other within the scope of the invention, and each embodiment can be appropriately modified or omitted.

101, 801 First roller, 102, 802 Second roller, 103 Cylindrical workpiece, 104, 1202 Z-shaped joint, 201, 804 Grip mechanism, 202 Support mechanism drive, 203 Grip mechanism drive, 204 Control unit of apparatus, 205, 805 jig, 206 fan block of gripping mechanism, 301 fan block support member, 302 conical block, 401 groove portion of first roller, 402, 901 rotation axis of first roller, 601
Rotating shaft of second roller, 602 Inclined surface of second roller, 701, 1001 Flange, 803 Hook-shaped workpiece, 806 Fixing jig, 902 Inclined surface of first roller, 1002 L-shaped joint, 1101 Z-shape Heel part of a cylindrical joint, 1201 L-shaped joint

Claims (7)

A first roller for forming the workpiece, the first roller for forming the workpiece, and a second roller for forming the workpiece, arranged to be in contact with the inner peripheral surface of the workpiece. Using a roller, a joint processing method for forming a joint on the periphery of the opening end of the workpiece,
A first step of bringing the first roller into contact with the outer peripheral surface of the workpiece;
Moving the second roller from the inside of the inner periphery of the workpiece to the outside of the outer periphery of the workpiece, and a second step of forming a flange portion at the opening end of the workpiece;
A third step in which the second roller moves in the axial direction of the workpiece and cooperates with the first roller to sandwich the flange portion and form a joint;
A method for processing a joint including:   The method of processing a joint according to claim 1, wherein the shape of the workpiece is cylindrical, and the cross-sectional shape of the joint is Z-shaped.   The method of processing a joint according to claim 1, wherein the shape of the workpiece is bowl-shaped, and the cross-sectional shape of the joint is L-shaped. Using the first roller and the second roller, a joint processing method for forming a joint having a Z-shaped cross section on the periphery of the opening end of the workpiece,
The outer diameter of the workpiece is R, the outer diameter of the first roller is r, Δ is a minute amount determined by r, the angle formed by the rotation axis of the first roller and the rotation axis of the workpiece is θ ₁ , ₂ , wherein θ ₁ + θ ₂ > 90 ° and θ ₂ satisfies the formula (1) for 0 ° <θ ₁ <90 °. Or the processing method of the coupling of Claim 2.

Using the first roller and the second roller, a joint processing method for forming a joint having a Z-shaped cross section on the periphery of the opening end of the workpiece,
The outer diameter of the workpiece is R, the outer diameter of the second roller is r ₂ , Δ is a minute amount determined by r ₂ , and the angle formed by the rotation axis of the second roller and the rotation axis of the workpiece is θ _3. When the bending angle of the joint is θ ₂ , θ ₃ + θ ₂ > 90 ° and θ ₂ satisfies the formula (2) for 0 ° <θ ₃ <90 °. Item 3. A method for machining a joint according to item 1 or 2.

Using the first roller and the second roller, a joint processing method for forming a joint having an L-shaped cross section at the opening end periphery of the workpiece,
The outer diameter of the workpiece is R, the outer diameter of the first roller is r, Δ is a minute amount determined by r, the angle formed by the rotation axis of the first roller and the rotation axis of the workpiece is θ ₁ , the inclination angle of the case of the theta _4, together with a _{θ 1 + θ 4> 90 °} , claim 0 ° <θ ₁ <θ ₄ with respect to 90 ° is characterized by satisfying the equation (3) 1 Or the processing method of the coupling of Claim 3.

After forming a workpiece having a cylindrical shape and a workpiece having a bowl shape using the joint processing method according to claim 1, the two types of workpieces are fitted to each other at an open end and welded. A tank manufacturing method for manufacturing a tank, comprising:
Of the workpiece having a cylindrical shape and the workpiece having a bowl shape, a Z-shaped joint is formed at one open end, an L-shaped joint is formed at the other open end, and the L A method for manufacturing a tank, comprising: forming a slant surface of a letter-shaped joint and the Z-shaped joint so as to form an acute angle with respect to a root portion of each joint;

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