JP2014114018A - Tank lorry - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide a tank lorry in which occurrence of a breakage and a crack in a weld zone between an inner peripheral surface of a tank or a vent pipe and a component for connection thereof can be suppressed.SOLUTION: A lower coupling device 60 is welded to an inner peripheral surface positioned on the lower side of a tank 10 in a vertical direction and to a horizontal part 41 of a vent pipe 40, and an upper coupling device 70 is welded to an inner peripheral surface positioned on the upper side of the tank 10 in the vertical direction and holds a vertical part 43 of the vent pipe 40 in such a manner that the vertical part 43 is displaceable in the vertical direction, whereby the vertical part 43 can be displaced along the vertical direction following displacement of the lower coupling device 60 in association with expansion or telescopic motion of the tank 10. Thus, stress generated in a weld zone between the inner peripheral surface of the tank 10 or the vent pipe 40 and the lower coupling device 60 and the upper coupling device 70 for connection thereof can be reduced, whereby occurrence of a breakage or a crack of the lower coupling device 60 and the upper coupling device 70 can be suppressed.

Description

  The present invention relates to a tank lorry, and more particularly to a tank lorry capable of suppressing the occurrence of breakage or cracks in a welded portion between an inner peripheral surface of a tank or a vent pipe and a member connecting them.

  In a tank lorry for transporting liquefied gas, a technique is known in which vaporized gas is sent into a tank to pressurize the tank, and the liquefied gas is sent out to an external tank by pushing out the liquefied gas (for example, Patent Document 1).

  Here, the internal structure of the tank 510 in the conventional tank truck 500 will be described with reference to FIGS. 5 and 6. FIG. 5 is a side view of a conventional tank truck 500. 6A is a cross-sectional view of the tank 510 taken along the line VIa-VIa of FIG. 5, and FIG. 6B is a partially enlarged view of the tank 510 viewed from the VIb direction of FIG. 6A. In FIG. 5, a part of the tank 510 is viewed in cross section.

  As shown in FIG. 5, the tank lorry 500 includes a cylindrical tank 510 on which liquefied gas is loaded, and a chassis frame 520 on which the tank 510 is mounted. The tank 510 is in the axial direction of the tank 510. (A left and right direction in FIG. 5) a plurality of wave blocking plates 530 arranged side by side, a substantially L-shaped ventilation pipe 540 disposed inside the tank 510 while avoiding the plurality of wave blocking plates 530, One end of the vent pipe 540 is connected, and a pipe seat 550 is installed on the lower side in the vertical direction of the tank 510 (lower side in FIG. 5).

  The vent pipe 540 has a vertical portion 541 extending upward (upward in FIG. 5) from the tube seat 550, one end connected to the vertical portion 541, and a rear side in the axial direction of the tank 510 (right side in FIG. 5). And the other end of the horizontal portion 542 is open inside the tank 510. The inside and the outside of the tank 510 are communicated with each other through a vent pipe 540 and a pipe seat 550, and the vaporized gas is sent from the outside of the tank 510 to the inside of the tank 510 through the pipe seat 550 and the vent pipe 540. As a result, the inside of the tank 510 is pressurized.

  Further, since the vent pipe 540 is formed in a substantially L shape having a vertical portion 541 and a horizontal portion 542, the pipe seat 550 is formed on the inner wall surface located on the front side in the axial direction of the tank 510 (left side in FIG. 5). Even when installed at close positions, the other end of the horizontal portion 542 can be disposed at a position away from the inner wall surface located on the front side in the axial direction of the tank 510. As a result, the liquefied gas whose liquid level fluctuates in the tank 510 as the tank lorry 500 starts and brakes rebounds on the inner wall surface located on the front side in the axial direction of the tank 510 and then flows into the other end of the horizontal portion 542. Can be avoided.

  As shown in FIGS. 6 (a) and 6 (b), a plate-like upper coupling tool 560 is erected on the inner peripheral surface located on the upper side in the vertical direction of the tank 510, and the upper coupling tool 560 is connected to the tank. The horizontal portion 542 is fixed to the inner peripheral surface of the tank 510 by being welded to the inner peripheral surface of 510 and the horizontal portion 542 of the ventilation pipe 540.

JP 2004-68956 A (paragraph 0003 etc.)

  However, in the conventional tank lorry 500 described above, the vent pipe 540 is connected to the pipe seat 550 on the lower side in the vertical direction, and is fixed to the inner peripheral surface of the tank 510 via the upper connector 560 on the upper side in the vertical direction. When the tank 510 expands or contracts due to pressurization or decompression in the tank 510, stress in the vertical direction is generated in the vent pipe 540 and the upper connector 560 that connects the vent pipe 540 and the inner peripheral surface of the tank 510. . Therefore, there has been a problem that breakage or cracks are likely to occur in the welded portion between the upper connector 560 and the inner peripheral surface of the tank 510 or the horizontal portion 542 of the vent pipe 540.

  The present invention has been made to solve the above-described problems, and a tank lorry capable of suppressing the occurrence of breakage or cracks in a welded portion between an inner peripheral surface of a tank or a vent pipe and a member connecting them is provided. It is intended to provide.

Means for Solving the Problems and Effects of the Invention

  According to the tank truck of claim 1, the lower connector is welded to the inner peripheral surface located on the lower side in the vertical direction of the tank and the horizontal portion of the vent pipe, and the upper connector is arranged on the inner circumference located on the upper side in the vertical direction of the tank. Since the vertical portion of the vent pipe is welded to the surface and is displaceable in the vertical direction, when the lower connector is displaced in the vertical direction as the tank expands or contracts, the lower connector is displaced. Following this, the vertical portion can be displaced along the vertical direction. As a result, the stress generated in the welded portion between the inner peripheral surface of the tank or the vent pipe and the lower and upper couplers connecting them can be reduced, so that the welded parts are damaged or cracked. There is an effect that can be suppressed.

  Here, the tank is supported by the chassis frame 20 on the lower side in the vertical direction, and the wave preventing plates are fixed to the inner peripheral surfaces located on the left side and the right side of the chassis frame of the tank. Rigidity is high in the portions located on both sides in the left-right direction of the chassis frame. Therefore, when the inside of the tank is pressurized or depressurized, the displacement due to expansion or contraction of the tank becomes larger on the upper side in the vertical direction of the tank than on the lower side in the vertical direction of the tank and the left and right sides of the chassis frame.

  On the other hand, since the vertical part is held so as to be displaceable in the vertical direction by the upper connector connected to the inner peripheral surface located on the upper side in the vertical direction of the tank, the vertical part is moved along with the expansion or contraction of the tank. It can be easily displaced in the vertical direction. As a result, there is an effect that it is possible to reduce the stress generated in the welded portion between the inner peripheral surface of the tank or the vent pipe and the lower connector or the upper connector as the tank expands or contracts.

  According to the tank lorry of claim 2, in addition to the effect produced by the tank lorry of claim 1, the lower connector is formed in a rectangular flat plate shape, and the thickness direction of the lower connector is directed in the circumferential direction of the tank. Since one side end of the lower connector and the inner peripheral surface located on the lower side in the vertical direction of the tank are welded along the axial direction of the tank, the tank expands or contracts. Thus, the stress generated at the welded portion between one side end of the lower connector and the inner peripheral surface of the tank can be reduced.

  That is, when the inside of the tank is pressurized or depressurized, the inner peripheral surface of the tank expands and contracts mainly in the circumferential direction. On the other hand, since the lower connector is not expanded or contracted by pressurization or decompression in the tank, the plate thickness direction of the lower connector is arranged in the axial direction of the tank, and one side end of the lower connector and the tank When the inner peripheral surface is welded along the circumferential direction of the tank, the welding dimension between the lower connector and the inner peripheral surface of the tank in the circumferential direction of the tank becomes longer, so the stress generated at the welded portion is larger. Therefore, breakage and cracks are likely to occur.

  On the other hand, the lower connector is disposed with the plate thickness direction directed in the circumferential direction of the tank, and one side end of the lower connector and the inner peripheral surface located on the lower side in the vertical direction of the tank are connected to the axis of the tank. By welding along the center direction, the welding dimension between the lower connector in the circumferential direction of the tank and the inner peripheral surface of the tank is shortened. Therefore, welding between one side end of the lower connector and the inner peripheral surface of the tank is performed. It is possible to reduce the stress generated in the portion, and as a result, it is possible to suppress the occurrence of breakage and cracks in the welded portion between one side end of the lower connector and the inner peripheral surface of the tank.

  According to the tank lorry of claim 3, in addition to the effect of the tank lorry of claim 2, the lower connector is fixed to the inner peripheral surface of the tank at a position spaced from the tube seat, and the lower connector and the tube seat The distance between the lower connector and the horizontal part of the vent pipe is set to be larger than the weld dimension along the axis of the tank. The deformation | transformation of the horizontal part of the ventilation pipe which accompanies can be made loose.

  That is, the amount of displacement of the lower connector accompanying expansion or contraction of the tank depends on the rigidity of the inner peripheral surface of the tank located at the welded portion of the lower connector, and the rigidity of the inner peripheral surface of the tank is It is influenced by the fixing position of the plate and the installation position of other members arranged in the tank. Therefore, a displacement difference is likely to occur between the displacement amount of the lower connector due to expansion or contraction of the tank and the displacement amount of the pipe seat, and the horizontal portion of the vent pipe is deformed by the displacement difference.

  Also, the portion of the horizontal portion of the vent pipe where the lower connector is welded is highly rigid and difficult to deform, and therefore, due to the difference in displacement between the displacement of the lower connector and the displacement of the tube seat in the horizontal portion of the vent tube. The deformable portion is a portion located between the tube seat and the lower connector in the axial direction of the tank. Therefore, if the distance between the lower connector and the pipe seat along the axial direction of the tank is small, the length of the deformable portion is shortened by the expansion or contraction of the tank in the horizontal portion. The stress generated in the plate increases and the horizontal portion is easily damaged.

  On the other hand, the distance between the lower connector and the pipe seat along the axial direction of the tank is set to be larger than the weld size along the axis of the tank between the lower connector and the horizontal portion of the vent pipe. As a result, the length of the deformable portion can be increased as the tank expands or contracts in the horizontal portion, so that the stress generated in the horizontal portion can be reduced, resulting in damage to the horizontal portion. There is an effect that can be suppressed.

  According to the tank lorry described in claim 4, in addition to the effect produced by the tank lorry described in claim 3, the distance between the lower connector and the tube seat along the axial direction of the tank is in the axial direction of the tank. Since it is set to be larger than the distance between the lower connector and one end of the bent portion of the vent pipe, it is possible to reduce the stress of the horizontal portion generated by expansion or contraction of the tank, and By arranging it close to the bent portion, the vertical portion can be easily displaced along the vertical direction. As a result, the stress generated at the welded portion between the one side end of the lower connector and the inner peripheral surface of the tank can be reduced, and the welded portion between the one end of the lower connector and the inner peripheral surface of the tank. There is an effect that the occurrence of breakage and cracks can be suppressed.

  According to the tank lorry of the fifth aspect, in addition to the effect produced by the tank lorry according to any one of the first to fourth aspects, since the vertical portion of the ventilation pipe is inserted into the insertion hole of the insertion portion, There is an effect that the displacement of the vertical portion in the front-rear and left-right directions can be restricted while allowing the displacement in the direction.

  In addition, the standing portion and the inner peripheral surface located on the upper side in the vertical direction of the tank are welded along the axial direction of the tank with the plate thickness direction of the standing portion facing the circumferential direction of the tank. Compared to the case where the standing portion and the inner peripheral surface of the tank are welded along the circumferential direction of the tank while the plate thickness direction of the mounting portion is directed in the axial direction of the tank, the standing portion and the tank in the circumferential direction of the tank are compared. As the weld dimension between the inner peripheral surface of the tank and the inner peripheral surface of the tank is shortened, the stress generated in the welded portion between the standing portion and the inner peripheral surface of the tank can be reduced. There is an effect that it is possible to suppress the occurrence of breakage and cracks in the welded portion.

  Furthermore, the upper connecting tool is connected to the erected tips of the pair of erected parts that are erected on the inner peripheral surface of the tank, thereby connecting the inserted part and the pair of erected parts. It is bent and formed. As a result, the upper connector can be deformed so as to follow the inner peripheral surface of the tank extending and contracting along the circumferential direction of the tank and to change the facing distance between the pair of upright portions. As a result, the stress generated in the welded portion between the standing portion and the inner peripheral surface of the tank can be reduced, so that the welded portion between the standing portion and the inner peripheral surface of the tank can be damaged or cracked. There is an effect that it can be suppressed.

  According to the tank lorry described in claim 6, in addition to the effect produced by the tank lorry described in claim 5, the upper connecting member is configured such that the connecting line constituting the connecting portion between the pair of standing portions and the insertion portion is a tank shaft. Since it is formed along the center direction, there is an effect that the opposing distance between the pair of standing portions can be easily changed following the expansion and contraction of the inner peripheral surface of the tank in the circumferential direction.

  According to the tank lorry of claim 7, in addition to the effect produced by the tank lorry of claim 5 or 6, the pair of holding members are in a state in which the surfaces facing each other are in contact with the outer peripheral surface of the vertical portion of the vent pipe Since the upper end in the vertical direction is fixed to the insertion portion, there is an effect that the displacement of the vertical portion in the front-rear and left-right directions in the chassis frame can be reliably regulated.

  The pair of holding members extend along the vertical direction and have a substantially L-shaped cross section perpendicular to the vertical direction, and a pair of opposing surfaces abut against the outer peripheral surface of the vertical portion. Therefore, there is an effect that the holding member can be easily aligned with the vertical portion of the vent pipe. In addition, there is an effect that the size management of the holding member can be easily performed as compared with the case where the holding member is formed in a cylindrical shape and the vertical portion is brought into contact with the inner peripheral surface thereof.

  Furthermore, since a large contact area between the holding member and the outer peripheral surface of the vertical portion of the ventilation pipe can be secured, it is possible to suppress local wear of the contact portion between the holding member and the vertical portion, and There is an effect that it is possible to prevent the vertical portion from being held out of the upper connector by releasing the vertical portion from the upper connector due to the vertical displacement of the portion.

It is a side view of the tank truck in one embodiment of the present invention. It is sectional drawing of the tank truck in the II-II line of FIG. It is sectional drawing of the tank in the III-III line of FIG. (A) is a partial cross-sectional view of the tank in the IVa portion of FIG. 2, (b) is a partial enlarged view of the tank viewed from the IVb direction of FIG. 4 (a), (c) is FIG. It is sectional drawing of the tank in the IVc-IVc line | wire of (a). It is a side view of the conventional tank truck. (A) is sectional drawing of the tank in the VIa-VIa line | wire of FIG. 5, (b) is the elements on larger scale of the tank seen from the VIb direction of FIG. 6 (a).

  Hereinafter, preferred embodiments of the present invention will be described with reference to the accompanying drawings. First, with reference to FIG.1 and FIG.2, the internal structure of the tank 10 of the tank truck 100 is demonstrated. FIG. 1 is a side view of a tank truck 100 according to an embodiment of the present invention, and a part of the tank 10 is viewed in cross section. 2 is a cross-sectional view of the tank truck 100 taken along the line II-II in FIG. In FIG. 2, only the main part of the tank 10 and the subframe 22 are schematically shown in order to simplify the drawing and facilitate understanding, and the other parts are not shown. Further, arrows UD, LR, and FB in FIG. 1 indicate the vertical direction, the left-right direction, and the front-rear direction of the tank 100, respectively.

  As shown in FIG. 1, a tank truck 100 is a vehicle for transporting liquefied gas, and mainly includes a cylindrical tank 10 on which liquefied gas is loaded and a chassis 20 with a cab on which the tank 10 is mounted. In preparation. When unloading the liquefied gas loaded in the tank 10 to an external storage tank or the like, the vaporized gas is sent to the inside of the tank 10 to pressurize the inside of the tank 10, and the liquefied gas in the tank 10 is The liquefied gas is sent out of the tank 10 by pushing out.

  The cab-attached chassis 20 includes a cab 21 as a cab and a vehicle body frame (not shown) that forms the skeleton of the cab-attached chassis 20, and a pair of left and right subs interposed between the vehicle body frame and the tank 10. A lower portion of the tank 10 is supported by the frame 22.

  The tank 10 is disposed inside the tank 10 while avoiding the plurality of wave blocking plates 30 and the plurality of wave blocking plates 30 arranged in parallel along the axial direction (left and right direction in FIG. 1) of the tank 10. And a pipe seat 50 that is connected to one end of the vent pipe 40 and that is installed on the lower side in the vertical direction of the tank 10 (lower side in FIG. 1).

  The wave preventing plate 30 is a plate-like member that suppresses the fluctuation of the liquid level of the liquefied gas in the tank 10, and both ends in the longitudinal direction are on the left side and the right side of the tank 10 (front side and back side in the vertical direction in FIG. 1). It is fixed to the inner peripheral surface located.

  The pipe seat 50 is a member that allows the inside and the outside of the tank 10 to communicate with each other. A part of the pipe seat 50 protrudes to the inside of the tank 10, and one end of the vent pipe 40 is connected to the protruding part.

  The vent pipe 40 is a tubular member formed in an approximately L shape. One end of the vent pipe 40 is connected to the pipe seat 50 and extends straight toward the rear side in the axial direction of the tank 10 (right side in FIG. 1). A horizontal portion 41, a bent portion 42 having one end connected to the other end of the horizontal portion 41 and bent in an arc shape, one end connected to the other end of the bent portion 42, and an upper side in the vertical direction (see FIG. 1), and the other end is provided with a linear vertical portion 43 that opens into the tank 10.

  By forming the vent pipe 40 in a substantially L shape, the other end of the opening vertical portion 43 can be disposed at a position away from the inner wall surface located on the front side in the axial direction of the tank 10 (left side in FIG. 1). When starting 100 or braking, the liquefied gas whose liquid level fluctuates in the tank 10 is prevented from bouncing back to the inner wall surface located on the front side in the axial direction of the tank 10 and flowing into the other end of the vertical portion 43. it can.

  The vent pipe 40 is connected to the inner peripheral surface of the tank 10 through a lower connector 60 in which the horizontal portion 41 is fixed to the inner peripheral surface located on the lower side in the vertical direction of the tank 10, and the vertical portion 43 is connected to the tank 10. It is connected to the inner peripheral surface of the tank 10 through an upper connector 70 fixed to the inner peripheral surface located on the upper side in the vertical direction.

  The lower connector 60 is welded to the inner peripheral surface of the tank 10 and the horizontal portion 41 of the vent pipe 40, and the upper connector 70 is welded to the inner peripheral surface of the tank 10 while the vertical portion 43 of the vent tube 40 is vertically oriented. It is held displaceable.

  As shown in FIG. 2, the tank 10 is supported by the subframe 22 on the lower side in the vertical direction (lower side in FIG. 2), and is located on the left side and right side (left side and right side in FIG. 2) of the chassis 10 with cab. Since the wave preventing plate 30 is fixed to the inner peripheral surface, the rigidity is high in the portion located on the lower side in the vertical direction of the tank 10 and on both sides in the left and right direction of the chassis 20 with cab. Therefore, when the inside of the tank 10 is pressurized or depressurized, the tank 10 expands on the upper side in the vertical direction of the tank 10 (upper side in FIG. 2) than the lower side in the vertical direction of the tank 10 and the left and right sides of the chassis 20 with cab. Or the displacement by shrinkage becomes large.

  On the other hand, the vertical portion 43 is held so as to be displaceable in the vertical direction by the upper connecting member 70 connected to the inner peripheral surface located on the upper side in the vertical direction of the tank 10. The vertical portion 43 can be easily displaced along the vertical direction by following the lower connecting tool 60 that is displaced in the vertical direction. As a result, the stress generated on the inner peripheral surface of the tank 10 or the welded portion between the vent pipe 40 and the lower connector 60 or the upper connector 70 as the tank 10 expands or contracts can be reduced.

  Next, the configuration of the lower connector 60 will be described with reference to FIG. FIG. 3 is a cross-sectional view of the tank 10 taken along the line III-III in FIG. 2, and shows a part of the tank 10 enlarged.

  As shown in FIG. 3, the lower connector 60 is formed in a rectangular flat plate shape, and is arranged in a state in which the thickness direction of the lower connector 60 is directed in the circumferential direction of the tank 10 (perpendicular to the paper surface of FIG. 3). , One side end (the lower side end in FIG. 3) of the lower connector 60 and the inner peripheral surface located on the lower side in the vertical direction of the tank 10, and the other side end of the lower connector 60 (the upper side in FIG. 3). End) and the horizontal portion 41 of the vent pipe 40 are welded along the axial direction of the tank 10 (the left-right direction in FIG. 3).

  Here, with reference to FIG. 6, the internal structure of the tank 510 in the conventional tank truck 500 is demonstrated.

  As shown in FIG. 6, conventionally, inside the tank 510, one end of the vent pipe 540 is connected to the pipe seat 550 (see FIG. 5) on the lower side in the vertical direction, and the horizontal portion of the vent pipe 540 on the upper side in the vertical direction. 542 was fixed to the inner peripheral surface of the tank 510 via the upper connector 560. That is, since the vent pipe 540 is restrained by the tank 510 on the upper side and the lower side in the vertical direction, when the tank 510 expands or contracts, the vent pipe 540 is passed by a vertical tensile force or compressive force acting on the vent pipe 540. By deforming the trachea 540, the vent pipe 540 is made to follow the expansion or contraction of the tank 510.

  Therefore, conventionally, the plate thickness direction of the upper connector 560 is arranged toward the axial direction of the tank 510 (the left-right direction in FIG. 6B), and the upper connector 560 and the inner peripheral surface of the tank 510 or the vent pipe 540 are disposed. Are welded along the circumferential direction of the tank 510 or the horizontal portion 542 to shorten the weld dimension of the upper coupling 560 in the axial direction of the tank 510 and the inner peripheral surface of the tank 510, and The shape of the trachea 540 was easily deformed.

  However, when the tank 510 expands or contracts, the inner peripheral surface of the tank 510 expands and contracts mainly in the circumferential direction. On the other hand, the upper connector 560 does not expand or contract as the tank 510 expands or contracts. Therefore, the weld size between the upper connector 560 and the inner peripheral surface of the tank 510 in the circumferential direction of the tank 510 is welded along the circumferential direction of the tank 510 with the upper connector 560 and the inner peripheral surface of the tank 510. As the length increases, the stress generated in the welded portion increases, and breakage and cracks are likely to occur. In particular, with the recent increase in the size of tanks and the increase in the transportation frequency of liquefied gas due to tank lorries, the magnitude of stress generated at the welded portion between the upper connector 560 and the inner peripheral surface of the tank 510 or the horizontal portion 542 of the vent pipe 540 is increased. The sheath frequency was increasing.

  Returning to FIG. In the present embodiment, the lower connector 60 is arranged in a state where the plate thickness direction is directed in the circumferential direction of the tank 10 (perpendicular to the plane of FIG. 3), and one side end of the lower connector 60 (the lower side in FIG. 3). Side end) and the inner peripheral surface of the tank 10 are welded along the axial direction (left and right direction in FIG. 3) of the tank 10, so the lower connector 60 and the inner peripheral surface of the tank 10 in the circumferential direction of the tank 10. As the welding dimension is shortened, the stress generated at the welded portion between the inner peripheral surface of the tank 10 and one side end of the lower connector 60 due to the expansion and contraction of the inner peripheral surface of the tank 10 can be reduced. Therefore, it is possible to suppress the occurrence of breakage or cracks in the welded portion between one side end of the lower connector 60 and the inner peripheral surface of the tank 10.

  Further, when welding one side end of the lower connector 60 and the inner peripheral surface of the tank 10 along the axial direction of the tank 10, one side end of the lower connector 60 and the inner peripheral surface of the tank 10 Since both parts to be welded are linear, the welding operation is simplified as compared with the case where one side end of the lower connector 60 and the inner peripheral surface of the tank 10 are welded along the circumferential direction of the tank 10. can do.

  When the inside of the tank 10 is pressurized or depressurized, the tube seat 50 and the lower connector 60 are also displaced as the tank 10 expands or contracts. However, the amount of displacement of the lower connector 60 depends on the rigidity of the inner peripheral surface of the tank 10 located at the portion where the lower connector 60 is welded, and the rigidity of the inner peripheral surface of the tank 10 is the wave blocking plate 30 ( 1) and the installation position of other members disposed in the tank 10. Therefore, a displacement difference is likely to occur between the displacement amount of the lower connector 60 and the displacement amount of the tube seat 50 due to the expansion or contraction of the tank 10, and the horizontal portion 41 of the vent pipe 40 is deformed by the displacement difference. .

  Further, the portion of the horizontal portion 41 where the other side end (the side end on the upper side in FIG. 3) of the lower connector 60 is welded is highly rigid and difficult to deform. The portion that can be deformed by the difference in displacement between the tube seat 50 and the displacement amount of the tube seat 50 is a portion located between the tube seat 50 and the lower connector 60 in the axial direction of the tank 10 (the left-right direction in FIG. 3).

  Therefore, if the distance between the tube seat 50 and the lower connector 60 along the axial direction of the tank 10 is small, the amount of displacement of the lower connector 60 and the amount of displacement of the tube seat 50 in the horizontal portion 41 are correspondingly reduced. Since the length of the deformable portion is shortened due to the displacement difference from the displacement amount, the stress generated in the horizontal portion 41 is increased, and the horizontal portion 41 is easily damaged. Therefore, it is desirable that the distance between the tube seat 50 and the lower connector 60 along the axial direction of the tank 10 is set longer.

  Therefore, the separation dimension along the axial center direction of the tank 10 between the tube seat 50 and the lower connector 60 is such that the tank 10 between the horizontal portion 41 and the other side end (upper side end in FIG. 3) of the horizontal portion 41. The welding dimension is preferably set to be longer than the welding dimension along the axial direction, and is set to be longer than the separation dimension along the axial direction of the tank 10 between the lower connector 60 and one end of the bent portion 42. desirable.

  Thereby, the horizontal part accompanying expansion or contraction of the tank 10 is secured by securing the length dimension of the deformable part due to the displacement difference between the displacement amount of the lower connector 60 and the displacement amount of the tube seat 50 in the horizontal part 41. 41 can be moderately deformed. As a result, since the stress generated in the horizontal portion 41 can be reduced, damage to the horizontal portion 41 can be suppressed.

  Further, the separation dimension along the axial center direction of the tank 10 between the tube seat 50 and the lower coupling tool 60 is set to be larger than the separation dimension along the axial center direction of the tank 10 between the lower coupling tool 60 and one end of the bent portion 42. By setting the length longer, the lower connector 60 can be disposed closer to the bent portion 42 accordingly. Thereby, since the vertical part 43 can be made easy to displace along a perpendicular direction, the stress which generate | occur | produces in the welding part of the one side end of the lower connection tool 60 and the internal peripheral surface of the tank 10 can be reduced. As a result, the occurrence of breakage and cracks at the welded portion between one side end of the lower connector 60 and the inner peripheral surface of the tank 10 can be suppressed.

  Next, the configuration of the upper connector 70 will be described with reference to FIG. 4 (a) is a partially enlarged view of the tank 10 in the IVa portion of FIG. 2, and FIG. 4 (b) is a partially enlarged view of the tank 10 viewed from the IVb direction of FIG. 4 (a). 4 (c) is a cross-sectional view of the tank 10 taken along line IVc-IVc in FIG. 4 (a).

  As shown in FIG. 4A to FIG. 4C, the upper couplers 70 are opposed to each other and are erected on the inner peripheral surface located on the upper side in the vertical direction of the tank 10 (upper side in FIG. 4A). A pair of standing portions 71, an insertion portion 72 connected to the standing tips of the pair of standing portions 71, and fixed vertically to the insertion portion 72 (downward in FIG. 4 (a)). And a pair of holding members 73 extending toward the surface.

  The pair of upright portions 71 are portions formed in a rectangular flat plate shape, and one side end of the upright portion 71 (FIG. 4) with the plate thickness direction of the upright portion 71 directed in the circumferential direction of the tank 10. (B) the upper side end) is welded to the inner peripheral surface of the tank 10.

  The insertion part 72 is a part formed in a rectangular flat plate shape, and includes an insertion hole 72a into which the vertical part 43 of the ventilation pipe 40 can be inserted. The vertical part 43 of the ventilation pipe 40 is inserted into the insertion hole 72a. . The insertion portion 72 has a pair of side ends positioned on both sides of the tank 10 in the left-right direction (FIG. 4 (a) left-right direction), and is connected to the standing tips of the pair of standing portions 71, respectively. In other words, the upper connector 70 is bent at the connecting portion between the pair of standing portions 71 and the insertion portion 72.

  Therefore, when the inner peripheral surface of the tank 10 expands or contracts in the circumferential direction due to expansion or contraction of the tank 10, the facing distance between the pair of standing portions 71 is changed following the inner peripheral surface of the tank 10. The upper connector 70 can be deformed. Thereby, since the stress which generate | occur | produces in the welding part of the side edge of the standing part 71 and the inner peripheral surface of the tank 10 can be reduced, the side edge of the one side of the standing part 71 and the tank 10 can be reduced. It is possible to suppress the occurrence of breakage or cracks at the welded portion with the inner peripheral surface.

  Further, the upper connecting tool 70 is formed with a straight connecting line 70a by bending a connecting part between the standing part 71 and the insertion part 72, and the upper connecting tool 70 is connected to the connecting line 70a. Is welded to the inner peripheral surface located on the upper side in the vertical direction of the tank 10 in a state in which it is directed in the axial direction of the tank 10. Accordingly, it is possible to easily change the facing distance between the pair of standing portions 71 following the inner peripheral surface of the tank 10.

  Further, the standing portion 71 and the inner peripheral surface located on the upper side in the vertical direction of the tank 10 are welded along the axial direction of the tank 10 with the plate thickness direction of the standing portion 71 facing the circumferential direction of the tank 10. As compared with the case where the standing portion 71 and the inner peripheral surface of the tank 10 are welded along the circumferential direction of the tank 10 while the plate thickness direction of the standing portion 71 is directed in the axial direction of the tank 10, By reducing the welding dimension between the standing portion 71 and the inner peripheral surface of the tank 10 in the circumferential direction of the tank 10, the stress generated at the welded portion between the standing portion 71 and the inner peripheral surface of the tank 10 can be reduced. As a result, it is possible to suppress the occurrence of breakage or cracks in the welded portion between the standing portion 71 and the inner peripheral surface of the tank 10.

  The pair of holding members 73 are members formed by bending a rectangular flat plate, and a cross section viewed from a direction perpendicular to the vertical direction in a state in which the upper connector 70 is fixed to the inner peripheral surface of the tank 10. Is formed in a substantially L-shape. The pair of holding members 73 are disposed opposite to each other with the vertical portion 43 of the ventilation pipe 40 interposed therebetween, and the surfaces facing each other of the pair of holding members 73 are in contact with the outer peripheral surface of the vertical portion 43, so An end (the upper end in FIG. 4C) is fixed to the insertion portion 72.

  Since the vertical portion 43 is inserted into the insertion hole 72 a of the insertion portion 72 and is in contact with a pair of holding members 73 fixed to the insertion portion 72 on the outer peripheral surface of the vertical portion 43, While allowing displacement in the vertical direction, the displacement of the tank 10 in the front-rear and left-right directions (FIG. 4 (a) left-right direction and the direction perpendicular to the paper surface) can be restricted.

  In addition, the holding member 73 is formed in an approximately L shape, and the two holding members 73 are opposed to each other with the vertical portion 43 interposed therebetween, and the opposing surfaces of the holding member 73 are brought into contact with the outer peripheral surface of the vertical portion 43. Therefore, for example, as compared with the case where the holding member is composed of one cylindrical member having an inner diameter equivalent to the outer diameter of the vertical portion 43, the dimension management of the holding member 73 can be easily performed, The holding member 73 can be easily aligned with the vertical portion 43.

  Further, by bringing the opposing surfaces of the pair of holding members 73 into contact with the outer peripheral surface of the vertical portion 43, a large contact area between the holding member 73 and the outer peripheral surface of the vertical portion 43 can be secured. Therefore, compared with the case where the displacement of the vertical portion 43 in the front-rear and left-right directions of the tank 10 is restricted only by being inserted through the insertion hole 72a of the insertion portion 72, local wear on the outer peripheral surface of the vertical portion 43 is suppressed. Can do. In addition, it is possible to prevent the vertical portion 43 from being released from the upper connection tool 70 when the vertical portion 43 comes out of the upper connection tool 70 due to the vertical displacement of the vertical portion 43.

  Here, the stress generated in the welded portion between the upper connecting member 560 and the inner peripheral surface of the tank 510 in the conventional tank lorry 500 shown in FIG. 6, the lower connecting member 60 and the upper connecting member 70 and the tank 10 in the present embodiment. The stress generated in the welded portion with the inner peripheral surface of the steel was measured. When a stress generated when an internal pressure of 2.1 MPa was applied to a tank having an inner diameter of 1900 mm was measured, it was found that the welded portion between the upper connector 560 and the inner peripheral surface of the tank 510 in the conventional tank lorry 500 had the largest main component. Whereas the stress was 59.1 MPa and the minimum principal stress was −220.2 MPa, in the present embodiment, the maximum principal stress is 25. At the welded portion between the lower connector 60 and the inner peripheral surface of the tank 10. The maximum principal stress was 20.3 MPa and the minimum principal stress was -70.7 MPa at the welded portion between the upper connector 70 and the inner peripheral surface of the tank 10.

  In the tank truck 100 according to the present embodiment, the vertical portion 43 of the vent pipe 40 is held by the upper connector 70 so as to be displaceable in the vertical direction, whereas in the conventional tank truck 500, the vent pipe 540 is vertical. Since it is fixed to the tank 510 on the upper side and the lower side in the direction, the tank 10 of the tank lorry 100 in the present embodiment is compared with the welded portion between the upper connector 560 and the inner peripheral surface of the tank 510 in the conventional tank lorry 500. It is thought that the stress which generate | occur | produces in the welding part of the inner peripheral surface or the vent pipe 40, and the lower connection tool 60 or the upper connection part 70 which connects them reduced.

  Thus, the lower connector 60 is welded to the inner peripheral surface located on the lower side in the vertical direction of the tank 10 and the horizontal portion 41 of the vent pipe 40, and the upper connector 70 is located on the inner circumference located on the upper side in the vertical direction of the tank 10. Since the vertical portion 43 of the vent pipe 40 is welded to the surface and is displaceable in the vertical direction, the vertical portion 43 is moved in the vertical direction following the displacement of the lower connector 60 accompanying the expansion or contraction of the tank 10. Can be displaced along. Thereby, since the stress which generate | occur | produces in the welding part of the inner peripheral surface of the tank 10, or the vent pipe 40, and the lower connection tool 60 and the upper connection tool 70 which connect them can be reduced, the lower connection tool 60 and the upper connection It is possible to prevent the tool 70 from being damaged or cracked.

  The present invention has been described above based on the embodiments. However, the present invention is not limited to the above embodiments, and various improvements and modifications can be made without departing from the spirit of the present invention. It can be easily guessed.

  For example, in the above-described embodiment, the case where the holding member 73 is formed to have a substantially L-shaped cross section has been described. However, the present invention is not necessarily limited to this, and is in contact with the outer peripheral surface of the vertical portion 43 of the vent pipe 40. The holding surface 73 may be formed of a single cylindrical member having an inner diameter equivalent to the outer diameter of the vertical portion 43.

  In each of the above embodiments, the case where the upper connector 70 includes the pair of holding members 73 has been described. However, the present invention is not necessarily limited thereto, and the pair of holding members 73 is omitted, and the thickness of the insertion portion 72 is increased. You may make it thicker than the plate | board thickness of the standing part 71. FIG. Accordingly, the displacement of the vertical portion 43 of the vent pipe 40 in the front-rear and left-right directions in the chassis 20 with cab can be restricted, and the material cost of the upper connector 70 can be suppressed by the amount that the holding member 73 is unnecessary.

100 Tank lorry 10 Tank 20 Chassis with cab (chassis frame)
30 Wave proof plate 40 Ventilation pipe 41 Horizontal part 42 Bending part 43 Vertical part 50 Pipe seat 60 Lower connection tool 70 Upper connection tool 70a Connection line 71 Standing part 72 Insertion part 72a Insertion hole 73 Holding member

Claims (7)

In a tank truck comprising a cylindrical tank loaded with liquefied gas and a chassis frame 20 on which the tank is mounted,
The tank is provided with a wave preventing plate having both longitudinal ends fixed to inner peripheral surfaces located on the left and right sides of the tank frame of the tank, and a tank disposed inside the tank while avoiding the wave preventing plate. A trachea, a pipe seat that communicates the inside of the tank with the outside via the vent pipe, and is installed in the tank on the lower side in the vertical direction; and an inner circumference that is positioned on the lower side in the vertical direction of the tank. A lower connector to be connected to the surface, and an upper connector to connect the vent pipe to an inner peripheral surface located on the upper side in the vertical direction of the tank,
The vent pipe has one end connected to the pipe seat and a straight horizontal portion extending along the axial direction of the tank, and one end connected to the other end of the horizontal portion and an arc shape. A bent portion formed to be bent, and a linear vertical portion having one end connected to the other end of the bent portion and extending along the vertical direction and the other end opened to the inside of the tank,
The lower connector is welded to the inner peripheral surface of the tank and the horizontal portion of the vent pipe, and the upper connector is welded to the inner peripheral surface of the tank, and the vertical portion of the vent pipe can be displaced in the vertical direction. A tank lorry characterized by being held in   The lower connector is formed in a rectangular flat plate shape and arranged with the thickness direction of the lower connector facing the circumferential direction of the tank, and one side end of the lower connector and the vertical of the tank 2. A tank truck according to claim 1, wherein an inner peripheral surface located on the lower side in the direction is welded along the axial direction of the tank.   The lower connector is welded to the horizontal portion of the vent pipe at a position spaced from the tube seat, and the distance between the lower connector and the tube seat along the axial direction of the tank is The tank lorry according to claim 2, wherein the tank lorry is set to be larger than a welding dimension of the lower connector and the horizontal portion along the axial center direction of the tank.   In the lower connector, the distance between the lower connector and the tube seat along the axial direction of the tank is such that the lower connector and one end of the bent portion of the vent pipe are in the axial direction of the tank. The tank lorry according to claim 3, wherein the tank lorry is set to be larger than the separation dimension along the line. The upper connector is formed in a rectangular flat plate shape and has a pair of facing each other that are erected on the inner peripheral surface located on the upper side in the vertical direction of the tank in a state where the thickness direction is directed to the circumferential direction of the tank. A standing insertion portion, and a flat plate-like insertion portion having an insertion hole through which a vertical portion of the vent pipe can be inserted, which is connected to the standing tip of the pair of elevation portions.
The vertical portion of the vent pipe is inserted through the insertion hole of the insertion portion, and one side end of the standing portion and the inner peripheral surface located on the upper side in the vertical direction of the tank are in the axial direction of the tank. The tank truck according to any one of claims 1 to 4, wherein the tank truck is welded along.   The said upper connection tool is characterized by the continuous line which comprises the connection part of a pair of said standing part and the said insertion part being formed along the axial center direction of the said tank. Tank lorry. The upper connector includes a pair of holding members that extend along the vertical direction and have a substantially L-shaped cross section perpendicular to the vertical direction,
The pair of holding members are arranged to face each other with the vertical portion of the vent pipe interposed therebetween, and end portions on the upper side in the vertical direction with the opposing surfaces of the pair of holding members in contact with the outer peripheral surface of the vertical portion The tank lorry according to claim 5 or 6, wherein is fixed to the insertion portion.

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