JP2018136104A - Tank and manufacturing method thereof - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide a tank capable of properly preventing failure such as a crack easily occurring at a welding part due to change of internal pressure of a tank body, and having excellent durability.SOLUTION: A tank T has a tank body Ta comprising: a cylindrical trunk plate 1 in which a trunk plate welding part Wa extending in an axial length direction is provided at a peripheral wall part 12; and a bowl-shaped mirror plate 2 contacting with the trunk plate 1 in a state where an opening peripheral edge part 20 is fitted or butted to an end part of the trunk plate 1, and connected to the trunk plate 1 through an annular welding part Wb provided at the contact portion. The annular welding part Wb is configured such that an origin/terminal region P is positioned in an arbitrary place of a half region opposite to the trunk plate welding part Wa.SELECTED DRAWING: Figure 1

Description

  The present invention relates to a tank suitable for storing hot water for hot water generated by using a heat source such as a heat pump and other fluids, and a method for manufacturing the same.

An example of the tank is a hot water storage tank used in a hot water supply apparatus. As described in Patent Document 1, for example, this hot water storage tank generally has a tank body formed by joining a cylindrical body plate and a bowl-shaped end plate. Here, the cylindrical body plate is manufactured by rounding a metal plate and welding the side edges of the metal plate. For this reason, this body plate is provided with a welded portion (body plate welded portion) extending in the axial length direction. The bowl-shaped end plate is manufactured by deep drawing a metal plate. The end plate and the body plate are joined by fitting the peripheral edge of the opening of the end plate to the end of the body plate or bringing the end plate into contact with each other, and then welding in the circumferential direction of the contact portion. For this reason, an annular welded portion is provided at the joint between the body plate and the end plate.
According to such a configuration, it is possible to manufacture hot water storage tanks of various capacities at a relatively low cost using a thin metal plate as a raw material.

  However, the prior art has room for improvement as described below.

  That is, when hot water flows into and out of the tank body, the internal pressure of the tank body changes. As a result, for example, a body plate of the tank body generates a stress that acts to expand and contract each part of the body plate in the radial direction. On the other hand, since the body plate has a body plate welded portion extending in the axial direction, welding distortion occurs along this body plate welded portion, and the cross-sectional shape of the body plate is true in this portion. In many cases, the circularity is impaired. The above-described welding distortion tends to be greatest at the end of the body plate. For this reason, when the internal pressure of the tank body changes, the amount of deformation near the body plate welded portion (including the body plate welded portion, the same applies hereinafter) becomes larger than the amount of deformation in other regions of the body plate. In this case, the amount of deformation in the vicinity of the end portion of the body portion is particularly likely to be the largest.

On the other hand, the annular welded portion that joins the end plate and the body plate has a start point / end point region in which the start point and end point of the welding are substantially coincident with each other. Compared with this part, poor welding such as perforation (melting-down) is inherently likely to occur. This is because the start point and end point of the annular welded part are the static / dynamic switching positions of the welding torch, and it is difficult to stabilize various conditions such as the applied voltage and shield gas flow rate for welding. by.
Here, in the past, when providing an annular welded portion to join the end plate and the body plate, the position of the start point / end point region relative to the body plate welded portion, The fact is that nothing is taken into account. For this reason, the start point / end point region of the annular welded portion is provided at a position relatively close to the body plate welded portion.

  However, according to such a configuration, the start point / end point region of the annular welded portion is strongly influenced by the deformation of the vicinity of the body plate welded portion when the internal pressure of the tank body changes, and the amount of deformation is also large. growing. As a result, stress concentration occurs in the start point / end point region of the annular welded portion that is likely to cause poor welding originally, and defects such as cracks are likely to occur in this portion. This is not preferable in increasing the durability of the hot water storage tank.

In addition, if the start and end areas of the annular welded part are arranged near the body plate welded part where the welding distortion is large, the body plate and the end plate are properly connected at the locations corresponding to the start and end areas of the annular welded part. There is also a risk that it will be difficult to make it closely contact. In this case, the welding quality of the start point / end point region of the annular welded portion is further deteriorated, and it becomes easier to cause poor welding such as perforation in this portion. Such poor welding is also a major factor in reducing the durability of the hot water storage tank.

Japanese Patent No. 5050744

  The present invention has been conceived under the circumstances as described above, and appropriately prevents a defect such as a crack easily occurring in a weld due to a change in internal pressure of the tank body, and is durable. It is an object of the present invention to provide a tank that can be excellent in water and a manufacturing method thereof.

  In order to solve the above problems, the present invention takes the following technical means.

The tank provided by the first aspect of the present invention has a cylindrical shell plate in which a shell plate welded portion extending in the axial length direction is provided on the peripheral wall portion, and an opening peripheral portion is fitted to an end portion of the shell plate. A tank body having a tank-shaped end plate that is in contact with each other in a mated or butted state and is joined to the body plate via an annular weld provided in the contact portion. The annular welded portion is characterized in that the start point / end point region is located in any one of the half regions opposite to the body plate welded portion.
Here, the “half region opposite to the body plate welded portion” corresponds to, for example, the region A shown in FIG. This figure is a sectional view (plan sectional view) of the tank body Ta as viewed in the axial direction. In the figure, in the region A, when the angle θ is increased in a certain direction around the center O of the tank body Ta after the position of the body plate welded portion Wa is set to 0 °, the angle θ is 90 °. It is in the range of ° to 270 °.

According to such a configuration, the following effects can be obtained.
That is, in the above-described configuration, among the annular welded portion for joining the body plate and the end plate, the start point and the end point region where the possibility that the quality of welding is likely to be low is arranged away from the body plate welded portion. ing. Therefore, according to the present invention, unlike the prior art, when the internal pressure of the tank main body changes due to the flow of fluid such as hot water into and out of the tank main body, the vicinity of the body plate welded portion is relatively greatly deformed. Even if the phenomenon occurs, it is difficult to affect the start point / end point region of the annular welded portion, and stress concentration can be prevented from occurring in the start point / end point region. As a result, it is difficult for defects such as cracks to occur in the start point and end point regions of the annular welded portion, and the durability of the tank can be improved.
Furthermore, if the start point / end point region of the annular welded part is arranged away from the body plate welded part where the welding distortion is large, the welding is performed at a location corresponding to the start point / end point region of the annular welded part, unlike the prior art. It is also possible to eliminate the difficulty of properly bringing the body plate and the end plate into close contact with each other. For this reason, it can suppress that the welding quality of the start point and end point area | region of a cyclic | annular weld part falls, and can also make it difficult to produce poor welding, such as a hole (melting-down). As a result, the durability of the tank can be further enhanced.

  In the present invention, preferably, the start point / end point region of the annular welded portion is provided at a position substantially opposite to the body plate welded portion with the center of the tank body interposed therebetween.

According to such a configuration, the position of the start point / end point region of the annular welded portion is the farthest position from the body plate welded portion in the annular welded portion. For this reason, it is optimized to prevent the influence of welding distortion in the vicinity of the body plate welded portion from reaching the start point / endpoint region of the annular welded portion, or close to optimization. Therefore, it is more preferable in enhancing the durability of the tank.

  In the present invention, preferably, at least one of the body plate and the end plate is reinforced so as to straddle both side regions of the body plate welded portion in the axial direction of the tank body. A member is further provided.

  According to such a configuration, the vicinity of the body plate welded portion of the tank main body can be prevented from being greatly deformed with the change in the internal pressure of the tank main body by the reinforcing action using the reinforcing member. Therefore, it is possible to further suppress the vicinity of the start point / end point region of the annular welded portion from being greatly deformed due to the influence of the vicinity of the body plate welded portion, and to make it difficult for stress concentration to occur in the start point / end point region. As a result, it is possible to more appropriately prevent a defect such as a crack from occurring in the start point / end point region.

  In the present invention, preferably, at least one of the body plate and the end plate is reinforced so as to straddle both side regions of the start point and end point regions in the axial length direction of the tank body. A member is further provided.

  According to such a configuration, the vicinity of the start point / end point region of the annular welded portion can be reinforced by the reinforcing member. Therefore, when the internal pressure of the tank changes, it is difficult for stress concentration to occur in the start point / end point region of the annular welded portion, and it is possible to more thoroughly prevent the occurrence of defects such as cracks.

  In this invention, Preferably, the said reinforcement member is a leg part which supports the said tank main body.

  According to such a configuration, since the tank leg portion is also used as the reinforcing member, the configuration is reasonable, and an increase in the number of parts can be appropriately eliminated.

  The tank manufacturing method provided by the second aspect of the present invention includes an end portion of a cylindrical body plate in which a body plate welded portion extending in the axial length direction is provided on the peripheral wall portion, and an opening of a bowl-shaped end plate A welding step for forming a tank main body by joining the body plate and the end plate by bringing the peripheral portion into contact with each other in a fitted or butted state and providing an annular welded portion at the contact portion; The tank manufacturing method is characterized in that the annular welded portion is provided so that a start point / end point region is located in any one of the half regions opposite to the body plate welded portion.

  According to such a configuration, the tank provided by the first aspect of the present invention can be appropriately manufactured.

  Other features and advantages of the present invention will become more apparent from the following description of embodiments of the present invention with reference to the accompanying drawings.

(A) is a perspective view which shows an example of the hot water storage tank to which this invention was applied, (b) is Ib-Ib sectional drawing of (a), (c) is the principal part of (b). It is an enlarged view. (A)-(d) is a schematic perspective view which shows an example of the manufacturing process of the hot water storage tank shown in FIG. It is a perspective view which shows the other example of this invention. It is explanatory drawing which shows the positional relationship of the body plate welding part in this invention, and the starting point and end point area | region of an annular welding part.

  Hereinafter, preferred embodiments of the present invention will be specifically described with reference to the drawings.

  FIG. 1 shows a hot water storage tank T as an example of a tank to which the present invention is applied, and FIG. 2 shows a manufacturing method thereof. The configuration of the hot water storage tank T will be described with reference to FIG.

  The hot water storage tank T shown in FIG. 1 is used, for example, as a component of a hot water storage type hot water supply apparatus, and is used for storing hot water heated using a heat pump or other predetermined heat source. As shown in FIG. 2A, the hot water storage tank T includes a tank body Ta made of metal such as stainless steel, which is constructed by welding end plates 2 (2a, 2b) on the upper and lower sides of the body plate 1, and the tank. It is the structure provided with the several leg part 3 which supports the main body Ta in the attitude | position which stood up in the up-down height direction. Although omitted in the drawing, piping for flowing hot water for hot water supply into and out of the tank body Ta is connected to the upper portion of the upper end plate 2 (2a) and the lower portion of the lower end plate 2 (2b). Has been.

  As shown in FIG. 2A, the body plate 1 is manufactured by rolling a flat metal plate 1a as a raw material into a cylindrical shape and welding the two edge portions 10 of the metal plate 1a. is there. This welding is, for example, TIG welding. The welding shown in FIG. 2C to be described later is also TIG welding, and in these drawings, reference numeral 8 is a TIG welding torch. The body plate 1 has a cylindrical shape in which the body plate welded portion Wa by the welding extends in the axial length direction (vertical height direction) on the peripheral wall portion 12.

  Each end plate 2 is formed by subjecting a metal plate as a raw material to deep drawing or the like, so that the overall schematic shape is formed into a bowl shape having an opening on one end side, and has an opening peripheral portion 20 ( (See also FIG. 2 (b)). As shown in FIG. 2 (c), the upper and lower end panels 2 are brought into contact with the peripheral edge 20 of the opening in a state of being fitted or abutted to the upper end and lower end of the body plate 1, and this contact. The body plate 1 is joined by welding over the entire circumference of the part. The welding position is the annular welded portion Wb, and there are two upper and lower annular welded portions Wb. The start point / end point region P of each annular welded portion Wb is located at a position substantially opposite to the body plate welded portion Wa across the center O of the tank body Ta, that is, on a straight line L connecting the body plate welded portion Wa and the center O, Alternatively, the position is in the vicinity of the straight line L (see also FIG. 1B). The starting point (welding starting point) and the ending point (welding end point) of the annular welded portion Wb are in substantially the same arrangement or in a considerably close arrangement, and the start point / end point region P is regarded as one region. Is.

  In FIG. 1A, each leg portion 3 is configured to include a bracket portion 30 joined to the tank body Ta and a leg body portion 31 extending downward from the bracket portion 30. The bracket portion 30 is, for example, a metal plate having a substantially L-shaped or substantially V-shaped cross section, and left and right side edges 30a of the bracket portion 30 are welded to the outer surface of the tank body Ta. The upper part of the leg body part 31 is connected to the bracket part 30 by means such as bolting, and the lower end part of the leg body part 31 is provided with an anchor bolt or the like on the floor surface on which the hot water storage tank T is installed. It can be fixed using.

The plurality of leg portions 3 are attached to the outer peripheral surface of the lower region of the body plate 1 at substantially equal angular intervals. However, as clearly shown in FIG. 1C, the leg 3A is welded to both side areas AR1 so as to straddle both side areas AR1 of the body plate welded portion Wa (see FIG. 1C). (See also FIG. 2 (d)). 3 A of leg parts play the role which reinforces lower end vicinity Sb of the trunk | drum board welding part Wa, and are equivalent to an example of the reinforcement member said by this invention. On the other hand, in FIG. 1 (b), the leg 3B located on the opposite side of the leg 3A across the center O of the tank body Ta is located on both side areas AR2 of the start point / end point area P of the annular welded part Wb. It is welded to these two side areas AR2 so as to straddle.

  Next, the operation of the hot water storage tank T will be described.

  First, some welding distortion has generate | occur | produced in the area | region along the trunk plate welding part Wa among the surrounding wall parts 12 of the trunk plate 1. FIG. Since the upper and lower end portions Sa and Sb of the body plate welded portion Wa are welded to the edge portion of the body plate 1, welding distortions in the upper and lower end portions Sa and Sb are likely to increase. Accordingly, the upper and lower end portions Sa and Sb of the body plate welded portion Wa are distorted portions so as to deteriorate the roundness of the peripheral wall portion 12 of the body plate 1. For this reason, when hot water flows into and out of the tank body Ta and the internal pressure of the tank body Ta changes, the upper and lower end portions Sa and Sb of the body plate welded portion Wa are more than the other parts of the body plate 1. It becomes a part which is easy to expand and contract greatly greatly in the radial direction of 1.

  Here, unlike the present embodiment, if the start point / end point region P of the annular welded portion Wb is close to the body plate welded portion Wa, the start point / endpoint region P is near the upper and lower ends of the body plate welded portion Wa. When the internal pressure of the tank main body Ta changes, the start point / end point region P may be greatly distorted due to the strong influence of Sa and Sb. On the other hand, in the present embodiment, the start point / end point region P of the annular welded portion Wb is at a position substantially opposite to the body plate welded portion Wa across the center O of the tank body Ta, and the body plate welded portion Wa. It is the most distant location. For this reason, when the internal pressure of the tank body Ta changes, the action that the body plate welded portion Wa is greatly deformed hardly reaches the start point / end point region P of the annular welded portion Wb. Therefore, the distortion of the start point / end point region P when the internal pressure of the tank body Ta changes can be reduced. The starting point / end point region P of the annular welded portion Wb is originally a portion that tends to cause a deterioration in the quality of welding, and it is desirable to prevent undue stress concentration from occurring in this portion. According to the embodiment, it is possible to appropriately realize such a thing. As a result, cracks or the like hardly occur in the start point / end point region P of the annular welded portion Wb, and the durability of the hot water storage tank T can be improved.

  As described above, the bracket portion 30 of the leg portion 3 (3A) is joined so as to straddle both the side regions AR1 of the body plate welded portion Wa, and reinforces these both side regions AR1. . Therefore, when the internal pressure of the tank body Ta changes, the lower end vicinity Sb of the body plate welded portion Wa is prevented from being greatly deformed in the radial direction of the body plate 1. As a result, it is possible not only to eliminate the possibility of cracks and the like in the vicinity of the lower end Sb of the body plate welded portion Wa, but also to change the start point / end point region P of the annular welded portion Wb and the vicinity of the lower end Sb of the body plate welded portion Wa The distortion due to the influence of the operation is further suppressed.

  The bracket part 30 of the leg part 3 (3B) is joined so as to straddle both side areas AR2 of the start point / end point area P of the annular welded part Wb, and reinforces these areas AR2. Accordingly, the effect of preventing the start point / end point region P of the annular welded portion Wb from being greatly deformed when the internal pressure of the tank body Ta is changed can be obtained by this. For this reason, it is possible to make cracks and the like less likely to occur in the start point / end point region P of the lower annular welded portion Wb among the upper and lower annular welded portions Wb. The start point / end point region P of the other upper annular welded portion Wb is not reinforced using the legs 3A and 3B, but the upper annular welded portion Wb has its start point as described above. -Based on the configuration in which the end point region P is disposed far from the body plate welded portion Wa, there is no particular problem because the effect of making the start point / end point region P less likely to crack is obtained.

In this embodiment, as shown in FIG.2 (c), when performing welding for providing the annular welded portion Wb, the start point / end point region P of the annular welded portion Wb is welded due to the body plate welded portion Wa. There will be no distortion. For this reason, in the start point / end point region P, the body plate 1 and the end plate 2 can be appropriately brought into contact with each other. Unlike the present embodiment, if the start point / end point region P of the annular welded portion Wb is set to a position in the vicinity of the shell plate welded portion Wa having a large welding distortion, the shell plate 1 is located at a position corresponding to the start point / end point region P. And the end plate 2 cannot be properly brought into contact with each other, and a gap that causes welding failure occurs between them, and the welding quality of the start point / end point region P may be deteriorated. According to the present embodiment, such a concern can be appropriately eliminated.

  FIG. 3 shows another embodiment of the present invention. In the figure, the same or similar elements as those of the above embodiment are denoted by the same reference numerals as those of the above embodiment, and redundant description is omitted.

In the embodiment shown in FIG. 3, the bracket portion 30 of the leg portion 3 </ b> A is joined to the area AR <b> 3 of the lower end plate 2 (2 b) instead of the body plate 1. This area AR3 is an area located on both sides of the body plate welded portion Wa in a plan view (an example of an axial length direction view in the present invention).
According to such a structure, unlike the said embodiment, although the bracket part 30 is not joined to the actual both-sides area | region AR1 of the trunk | drum plate welding part Wa, the end plate 2 and the trunk | drum 1 are joined. Since they are integrated, even in the configuration shown in FIG. 3, it is possible to reinforce the vicinity of the lower end Sb of the body plate welded portion Wa so as not to be easily deformed.
As will be understood from the present embodiment, in the present invention, by using a reinforcing member (leg part 3A), when reinforcing to suppress deformation near the body plate welded part when the internal pressure of the tank body changes, This reinforcing member does not necessarily have to be joined to the actual both side regions of the body plate welded portion. In short, it is joined to the portions corresponding to the both side regions of the body plate welded portion as viewed in the axial direction of the tank body. If it is in the arranged arrangement.

  Although omitted in FIG. 3, the same configuration as described above can also be applied to the case where the start point / end point region P of the lower annular welded portion Wb is reinforced using the leg portions 3B. . That is, by joining the bracket portion 30 of the leg portion 3B to the both side regions of the lower end plate 2 of the lower annular welded portion Wb in the plan view and the both side regions (lower regions of the two side regions AR2) in the plan view. A configuration in which the start point / end point region P of the lower annular welded portion Wb is indirectly reinforced can also be employed.

  FIG. 4 is a diagram taken into consideration in the column of “Summary of Invention”. In the present invention, the body plate welded portion Wa is used as a reference (angle 0 °), and the angle θ shown in the figure is within a range A (half region A on the opposite side to the body plate welded portion Wa). It is only necessary that the start point / end point region P of the annular welded portion Wb is disposed at any position. In the arrangement in which the start point / end point region P of the annular welded portion Wb is located away from the body plate welded portion Wa so as not to cause stress concentration in the start point / end point region P, as in the above-described embodiment, the start point It is preferable to arrange the end point region P so that the angle θ is approximately 180 °, but if it is in any of the above-described ranges A, the start point / end point region P is adversely affected by the welding distortion of the body plate welded portion Wa. Can be effectively suppressed, and the effect intended by the present invention can be obtained.

  The inventors have manufactured a tank body having the same structure as the tank body Ta of the hot water storage tank T shown in FIG. 1, and a body plate at both the time of pressurizing the tank body and the time of opening the tank body. An experiment was conducted to investigate the distribution of strain (radial strain) generated in each part of each end plate. According to this experiment, it was found that the distortion generated in the above-described range A is smaller than the distortion in the other ranges. Therefore, in the present invention, by arranging the start point / end point region P of the annular welded portion in the above-described range A, the effect of reducing the distortion generated in the start point / end point region P can be obtained from the above experimental results. Is also supported.

  The present invention is not limited to the contents of the above-described embodiment. The specific configuration of each part of the tank according to the present invention can be variously modified within the intended scope of the present invention. The specific configuration of each step of the method for manufacturing a tank according to the present invention can be variously changed within the intended scope of the present invention.

  In the above-described embodiment, the leg portion is used as the “reinforcing member” in the present invention, but the present invention is not limited to this. For example, a piping member such as a joint for piping or a pipe material or brackets that support various devices may be used as the reinforcing member. A metal plate having an appropriate shape such as a flat plate shape can also be used as the reinforcing member, and this reinforcing member may be a dedicated reinforcing member. In the above-described embodiment, the reinforcing members (the leg portions 3A and 3B) are provided only on the lower side of the tank body so as to correspond to the lower annular welded portion. However, instead of or in addition to this, a reinforcing member is provided. It can also be set as the structure in which the member was provided in the upper part side of the tank main body so that it might respond | correspond to an upper annular welded part.

The body plate welded portion and the annular welded portion are not limited to TIG welding, and the type of welding is not limited.
The tank according to the present invention is not limited to a hot water storage tank for a hot water supply device, and can be configured as a tank used for other purposes. The fluid put in the tank body is not limited to hot water and may be other fluids such as liquid and gas. Therefore, the material of the tank is not limited to stainless steel.

T Hot water storage tank (tank)
Ta tank body Wa body plate welded portion Wb annular welded portion P start point / end point region (of annular welded portion)
AR1 area on both sides (body plate welded part)
AR2 area on both sides (annular welds)
DESCRIPTION OF SYMBOLS 1 Body plate 12 Perimeter wall part 2 End plate 20 Opening peripheral part 3 (3A, 3B) Leg part (reinforcing member)

Claims (6)

A cylindrical body plate in which a body plate welded portion extending in the axial direction is provided on the peripheral wall portion;
A bowl-shaped end plate in which the peripheral edge of the opening contacts the end of the body plate in a fitted or abutted state, and is joined to the body plate via an annular weld provided in the contact portion;
A tank body comprising: a tank body comprising:
The tank is characterized in that the annular welded portion has a start point / end point region located in any one of the half regions on the opposite side to the body plate welded portion. The tank according to claim 1,
A tank in which a start point / end point region of the annular welded portion is provided at a position substantially opposite to the body plate welded portion across the center of the tank main body. The tank according to claim 1 or 2,
A reinforcing member that is joined so as to straddle both sides of the body plate welded portion of the tank body as viewed in the axial length direction of at least one of the body plate and the end plate is further provided. ,tank. The tank according to any one of claims 1 to 3,
A reinforcing member joined to straddle both side regions of the start point / end point region of the tank body as viewed in the axial length direction of at least one of the body plate and the end plate is further provided. ,tank. The tank according to claim 3 or 4,
The said reinforcement member is a tank which is a leg part which supports the said tank main body. An end portion of a cylindrical body plate in which a body plate welded portion extending in the axial length direction is provided on the peripheral wall portion is brought into contact with and in contact with an opening peripheral edge portion of a bowl-shaped end plate, and this contact portion A manufacturing method of a tank, which has a welding process for joining the body plate and the end plate to form a tank body by providing an annular welded portion,
The method for manufacturing a tank according to claim 1, wherein the annular welded portion is provided so that a start point / end point region is located in any one of the half regions opposite to the body plate welded portion.

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