Low-profile flat tank for liquefied petroleum gas storage and method of manufacturing the same

Abstract

A low-floor flat tank for liquefied petroleum gas (LPG) storage and a manufacturing method thereof can include a flat tank body including an upper plate having a plurality of first perforations and a pump mounting hole formed therethrough, a lower plate having a plurality of second perforations formed therethrough at positions coinciding with the plurality of first perforations in a vertical direction, and side plates integrally connecting first and second side end portions of the upper and lower plates, an end plate mounted to front and rear openings of the flat tank body, and a support tube having an upper end portion welded to inner circumferential portions of the plurality of first perforations and a lower end portion welded to inner circumferential portions of the plurality of second perforations to maintain a vertical spacing between the upper and lower plates.

Description

TECHNICAL FIELD

[0001] The present invention relates to a low profile flat bombe for liquefied petroleum gas (LPG) storage and a manufacturing method thereof. More particularly, the present invention relates to a low profile flat bombe for LPG storage, which can be easily installed at the bottom of a vehicle body to secure an indoor space and a loading space of a vehicle, and a manufacturing method thereof. BACKGROUND

[0002] In a vehicle provided with an LPI engine, a tank, which is configured to supply LPG fuel to the engine as a fuel tank, is manufactured in a cylindrical or donut type structure, and is disposed at the bottom of a trunk or a luggage compartment of the vehicle or at the bottom of the vehicle body of the vehicle.

[0003] However, since the manufacturing structure of the vehicle is to lower the overall height of the vehicle body and adjust the center of gravity of the vehicle body downward according to a vehicle design trend, and to lower the height of the vehicle body bottom to secure the comfort of indoor passengers of the vehicle (for example, to adjust the hip point of a seat downward), it is difficult to secure a space for installing the cylindrical or donut type tank.

[0004] For example, the cylindrical tank has a cylindrical structure with a long length and a large volume, and occupies a part of the internal space of the trunk or the luggage compartment, thereby greatly reducing the available space in the trunk or the luggage compartment.

[0005] In addition, in the vehicle body in which the overall height of the vehicle body is lowered, the center of gravity of the vehicle body is adjusted downward, and the height of the vehicle body bottom is lowered, there is a space limitation in installing the cylindrical or donut type tank at the vehicle body bottom.

[0006] The information disclosed in this Background section is only for the purpose of enhancing the understanding of the general background of the invention, and it can not be considered as admitting that this information forms the prior art known to those skilled in the art or any form of suggestion. SUMMARY

[0007] Aspects of the present invention are directed to providing a low profile flat bombe for LPG storage and a manufacturing method thereof, which has a flat structure of a rectangular shape, and thus can be easily installed at the bottom of a vehicle body to secure an indoor space and a loading space of a vehicle.

[0008] Aspects of the present application aim to provide a low-floor flat tank for LPG storage, the low-floor flat tank including a flat tank body including an upper plate having a plurality of first perforations and a pump mounting hole formed therethrough, a lower plate having a plurality of second perforations formed therethrough at positions coinciding with the plurality of first perforations in a vertical direction, and side plates integrally connecting first and second side end portions of the upper and lower plates, an end plate mounted to front and rear openings of the flat tank body, and support tubes having upper end portions welded to inner circumferal portions of the plurality of first perforations and lower end portions welded to inner circumferal portions of the plurality of second perforations to maintain a vertical spacing between the upper and lower plates.

[0009] In various exemplary embodiments of the present application, the upper and lower plates can be provided as plate body structures configured to have the same area and a longitudinal length greater than a lateral length, and the side plates and the end plate can be provided as curved surface structures configured to be outwardly convex and have a height identical to the vertical spacing between the upper and lower plates.

[0010] In various exemplary embodiments of the present application, the longitudinal length or the lateral length of the upper and lower plates can be provided to be greater than the height of the side plates and the end plate.

[0011] In various exemplary embodiments of the present application, a flange portion bent inward of the flat tank body to be welded to each of the support tubes can be formed at an inner circumferal portion of each of the plurality of first perforations and the plurality of second perforations.

[0012] In various exemplary embodiments of the present application, a plurality of baffle plates having fluid passage holes formed therethrough can be provided in a predetermined arrangement between the support tubes inside the flat tank body, and upper and lower end portions of each of the plurality of baffle plates can be welded to the upper and lower plates, respectively.

[0013] In various exemplary embodiments of the present application, each of the plurality of baffle plates can have a plate body structure bent at a specified angle to reduce and disperse stress concentrated in a space between adjacent support tubes in the flat tank body, and each of the plurality of baffle plates can be configured such that a length and an area of a portion of each of the plurality of baffle plates welded to the upper and lower plates are maximally increased.

[0014] In various exemplary embodiments of the present application, a bead portion configured to have a specified shape can be formed on the lower plate at a position coinciding with the pump mounting hole of the upper plate in the vertical direction, the bead portion protruding inward of the flat tank body.

[0015] In various exemplary embodiments of the present application, the boss portion configured to secure a space for installing a pump can be welded to the pump installation hole of the upper plate, and the at least two reinforcing blades configured to support and protect the pump can be connected by welding to the lower end of the boss portion welded to the pump installation hole of the upper plate and the convex rib portion of the lower plate.

[0016] In various exemplary embodiments of the present application, the reinforcing rib can be connected by welding to the at least two reinforcing blades.

[0017] In various exemplary embodiments of the present application, the reinforcing steel pipe for reducing local stress can be located in a central region between the upper plate and the lower plate and can be welded to the convex rib portions of the upper plate and the lower plate.

[0018] In various exemplary embodiments of the present application, the plurality of installation brackets configured to be fixedly assembled with a vehicle body can be installed on the flat can body and the end plate.

[0019] Aspects of the present application are directed to a manufacturing method of a low-floor flat can for LPG storage, the method including: manufacturing a plate body having a specified area; forming a plurality of first perforations and a pump installation hole through a side region of the plate body serving as an upper plate using a perforation and drawing process, while forming a plurality of second perforations through the other side region of the plate body serving as a lower plate; bending both side end portions of the plate body to form side plates; manufacturing a flat can body including the upper plate configured to have the plurality of first perforations and the pump installation hole formed through the upper plate, the lower plate configured to have the plurality of second perforations formed through the lower plate at positions coinciding with the plurality of first perforations in a vertical direction, and the side plates integrally connecting first and second side end portions of the upper and lower plates by welding the bent side end portions of the plate body; welding an end plate to front and rear openings of the flat can body; and welding upper end portions of a support pipe to inner circumferential portions of the plurality of first perforations, while welding lower end portions of the support pipe to inner circumferential portions of the plurality of second perforations, the support pipe being configured to connect the upper and lower plates to each other and maintain a vertical spacing between the upper and lower plates.

[0020] In various exemplary embodiments of the present application, the method can further include, before the end plate is welded to the front and rear openings, welding upper and lower end portions of a baffle plate configured to have a fluid passage hole to the upper and lower plates in a space between adjacent support pipes in an inner space of the flat can body.

[0021] In various exemplary embodiments of the present application, the method can further include, before the end plate is welded to the front and rear openings, welding a boss portion configured to secure a space for installing a pump to a pump installation hole of the upper plate, and welding at least two reinforcing blades configured to support and protect the pump to the boss portion and the lower plate.

[0022] In various example embodiments of the application, the method can further include assembling the pump assembly into the boss portion and the reinforcing vanes.

[0023] Other aspects and example applications of the application are discussed infra.

[0024] The above and other features of the application are discussed infra.

[0025] The method and apparatus of the present application has other features and advantages which will be apparent from or which will be elaborated upon in the accompanying drawings and in the following detailed description, which taken together illustrate certain principles of the application. BRIEF DESCRIPTION OF DRAWINGS

[0026] Figure 1 is an exploded perspective view of a low-floor flat tank for LPG storage according to various example embodiments of the present application;

[0027] Figure 2 is an assembled perspective view of a low-floor flat tank for LPG storage according to various example embodiments of the present application;

[0028] Figure 3 is a sectional view of a low-floor flat tank for LPG storage according to various example embodiments of the present application;

[0029] Figure 4 is a sectional view of a support pipe in a welding state among elements of a low-floor flat tank for LPG storage according to various example embodiments of the present application;

[0030] Figure 5 is a perspective sectional view of a baffle in a welding state among elements of a low-floor flat tank for LPG storage according to various example embodiments of the present application;

[0031] Figure 6 is a perspective sectional view of a boss portion and reinforcing vanes in a welding state among elements of a low-floor flat tank for LPG storage according to various example embodiments of the present application;

[0032] Figure 7 is a perspective sectional view of a reinforcing steel pipe in a welding state among elements of a low-floor flat tank for LPG storage according to various example embodiments of the present application;

[0033] Figure 8 、 Figure 9 、 Figure 10 、 Figure 11 and Figure 12are sequential perspective views exemplarily illustrating a manufacturing process of a low-floor flat tank for LPG storage according to various exemplary embodiments of the present application; and

[0034] Figure 13 are schematic views exemplarily illustrating a mounting position and state of a low-floor flat tank for LPG storage according to various exemplary embodiments of the present application.

[0035] It is to be understood that the drawings are not necessarily to scale, presenting a somewhat simplified representation of various preferred features illustrative of the basic principles of the application. The specific design features of the application as disclosed herein, including, for example, specific dimensions, orientations, locations, and shapes, will be determined in part by the particular intended application and use environment.

[0036] In the drawings, reference numerals in the various figures indicate like or equivalent parts. The embodiments of the application will be described with reference to the accompanying drawings in which: DETAILED DESCRIPTION

[0037] Reference will now be made in detail to various embodiments of the application, examples of which are illustrated in the accompanying drawings and described below. While the application will be described in conjunction with the exemplary embodiments, it will be understood that the description is not intended to limit the application to the exemplary embodiments. On the contrary, the application is intended to cover alternatives, modifications, equivalents, and other embodiments, which can be included within the spirit and scope of the application as defined by the appended claims.

[0038] Figure 1 、 Figure 2 and Figure 3 A low-floor flat tank for LPG storage according to various exemplary embodiments of the present application is shown, and in these drawings, reference numeral 100 denotes a flat tank body.

[0039] As shown in Figure 1 、 Figure 2 and Figure 3 , the flat tank body 100 includes an upper plate 110 configured to have a plurality of first perforations 111 and a pump mounting hole 112 formed through the upper plate 110, a lower plate 120 configured to have a plurality of second perforations 121 formed through the lower plate 120 at positions coinciding with the first perforations 111 in the up-and-down direction, and a side plate 130 configured to integrally connect both side end portions of the upper plate 110 and the lower plate 120.

[0040] Further, end plates 140 are welded to front and rear openings of the flat tank body 100 to provide a closed space for LPG filling of the flat tank and to prevent backflow or overflow of LPG.

[0041] The flat tank 100 can be easily installed on the bottom of a vehicle with a reduced overall height, a downwardly adjusted center of gravity, and a lowered vehicle body height without space limitations.

[0042] Therefore, the upper plate 110 and the lower plate 120 are configured as plate structures with the same area and a longitudinal length greater than the transverse length, and the side plate 130 and the end plate 140 are configured as curved structures with the same height as the vertical distance between the upper plate 110 and the lower plate 120 and protruding outward.

[0043] Furthermore, since the longitudinal or transverse lengths of the upper plate 110 and the lower plate 120 are set to be greater than the heights of the side plates 130 and the end plates 140, the flat tank 100 is manufactured in a flat rectangular shape. The flat tank 100 can be easily installed at the bottom of the vehicle body without space limitations, thus ensuring a large interior space and large loading space for the vehicle.

[0044] In the flat tank 100, the upper plate 110 and the lower plate 120 must not deform to easily withstand the internal pressure of the flat tank filled with LPG, and the vertical distance between the upper plate 110 and the lower plate 120 must always be kept constant.

[0045] For this purpose, multiple support tubes 150 are arranged between the upper plate 110 and the lower plate 120.

[0046] More specifically, such as Figure 4 As shown, the outer diameter portion of the upper end of the support tube 150 is attached to and welded to the inner circumference of the first through hole 111 of the upper plate 110, and the outer diameter portion of the lower end of the support tube 150 is attached to and welded to the inner circumference of the second through hole 121 of the lower plate 120.

[0047] Here, flanges 113 and 123 are formed on the inner periphery of the first perforation 111 and the second perforation 121 by drawing. The flanges 113 and 123 are bent toward the interior of the flat can 100 to be welded to the support tube 150.

[0048] Therefore, as Figure 4 As shown, exposed grooves 114 and 124 are formed in the contact area between the outer diameter portion of the upper end of the support tube 150 and the flange portion 113 of the inner periphery of the first through hole 111, and in the contact area between the outer diameter portion of the lower end of the support tube 150 and the flange portion 123 of the inner periphery of the second through hole 121, to provide spaces for easy welding.

[0049] Therefore, equipment such as welding torches can easily access valleys 114 and 124, thus enabling easy welding.

[0050] Accordingly, the support tubes 150 are integrally connected to the upper plate 110 and the lower plate 120 by welding, thereby serving to firmly fix the upper plate 110 and the lower plate 120 and maintain the up-and-down spacing between the upper plate 110 and the lower plate 120 constant, and thus the upper plate 110 and the lower plate 120 are not deformed by the internal pressure of the flat can filled with LPG.

[0051] A plurality of baffle plates 160 each including a plate body bent at a prescribed angle and a fluid passage hole 162 formed through the plate body are provided in a prescribed arrangement in the spaces between the adjacent support tubes 150 in the internal space of the flat can body 100, the upper end and the lower end of each baffle plate 160 being attached and welded to the lower surface of the upper plate 110 and the upper surface of the lower plate 120.

[0052] Accordingly, each baffle plate 160 is configured to reduce the speed of fluid and the noise caused thereby while allowing fluid such as LPG to flow through the fluid passage hole 162, and because the baffle plate 160 is connected to the upper plate 110 and the lower plate 120 by welding, the baffle plate 160 is also configured to disperse stress applied to the upper plate 110 and the lower plate 120.

[0053] Further, when the upper end and the lower end of each baffle plate 160 are attached and welded to the lower surface of the upper plate 110 and the upper surface of the lower plate 120, the welded portion of each baffle plate 160 can be formed to have as long a length as possible to mitigate stress applied to the flat can.

[0054] More specifically, each baffle plate 160 can have a plate body structure bent at a prescribed angle to mitigate and disperse stress concentrated in the spaces between the adjacent support tubes 150 in the internal space of the flat can body 100, and each baffle plate 160 is configured such that the length and area of the portion of the baffle plate 160 welded to the upper plate 110 and the lower plate 120 are maximally increased.

[0055] A pump assembly 200 configured to supply LPG to an engine of a vehicle is installed in and outside the flat can body 100.

[0056] To this end, a pump mounting hole 112 is formed through the upper plate 110, and a convex rib portion 125 having a prescribed shape is formed on the lower plate 120 at a position coinciding with the pump mounting hole 112 in the up-and-down direction, the convex rib portion 125 protruding toward the inside of the flat can body 100.

[0057] Here, the convex rib portion 125 is a kind of reinforcing structure that resists the load of the pump assembly 200, is protrusively formed using a press used to manufacture the upper plate 110 and the lower plate 120, and is formed to have an annular profile that surrounds the outer periphery of the lower end of the pump assembly 200.

[0058] Further, as Figure 6As shown, a cylindrical boss 170 configured to ensure space for mounting pump assembly 200 is welded to the inlet of pump mounting hole 112 in upper plate 110, and two or more curved reinforcing blades 172 configured to support and protect the pump are welded to the lower end of the boss 170 welded to pump mounting hole 112 in upper plate 110 and the rib 125 of lower plate 120.

[0059] The reinforcing rib 174 is further connected to two or more reinforcing blades 172 by welding.

[0060] Therefore, when the pump assembly 200 enters the interior of the flat tank 100 through the pump mounting hole 112 and is installed in the convex rib 125 of the lower plate 120, the outer periphery of the pump assembly 200 can be supported by the boss 170 and the reinforcing blade 172. Even if the load and stress of the pump are transmitted to the reinforcing blade 172, the reinforcing rib 174 can prevent the reinforcing blade 172 from deforming. Furthermore, since the convex rib 125, which is configured as a reinforcing structure, is formed on the lower plate 120 where the load and stress of the pump assembly 200 are concentrated, deformation of the lower plate 120 can be prevented.

[0061] Viewed from above, the flat tank 100 has a rectangular shape, and localized stress may concentrate in the central area between the upper plate 110 and the lower plate 120. To address this concentration, such as... Figure 7 As shown, a separate reinforcing steel pipe 176 can be located between the upper plate 110 and the lower plate 120 and connected by welding to the lower surface of the upper plate 110 and the protruding rib 125 of the lower plate 120.

[0062] Multiple mounting brackets 180, configured to be fixedly assembled with the vehicle body, are welded to the outer surfaces of both sides of the flat tank 100 and the outer surfaces of the end plates 140 in a specified arrangement.

[0063] Therefore, compared to conventional cylindrical or donut-shaped cans, the low-bottom flat cans according to various exemplary embodiments of the present invention are manufactured with a low height and a large surface area, thus... Figure 13 As shown, the low-chassis flat tank according to various exemplary embodiments of the present invention can be easily installed at the bottom 300 of the vehicle body, thereby ensuring a large interior space and a large loading space for the vehicle.

[0064] Furthermore, in a vehicle body with a reduced overall height and a downwardly adjusted center of gravity, and including a vehicle body bottom 300 with a reduced height, the low-chassis flat tank for LPG storage according to various exemplary embodiments of the present invention can be easily installed at the vehicle body bottom 300 without space limitations.

[0065] In the following, a method for manufacturing a flat can having the above-described structure according to various exemplary embodiments of the present invention will be described.

[0066] Figure 8 , Figure 9 , Figure 10 , Figure 11 and Figure 12 This is a perspective view illustrating, in turn, the manufacturing process of a low-chassis flat tank for LPG storage according to various exemplary embodiments of the present invention.

[0067] First, a metal plate with a specified area is manufactured.

[0068] Subsequently, by using perforation and drawing processes, a plurality of first perforations 111 and pump mounting holes 112 are formed through one side region of the metal plate serving as the upper plate 110, while a plurality of second perforations 121 are formed through the other side region of the metal plate serving as the lower plate 120. Then, the two ends of the metal plate are bent to form side plates 130.

[0069] Therefore, in order to manufacture the flat can 100, such as Figure 8 As shown, by perforating and drawing a metal plate with a specified area, a first perforation 111 and a pump mounting hole 112 can be formed through one side region of the metal plate used as the upper plate 110, while a second perforation 121 can be formed through the other side region of the metal plate used as the lower plate 120, and the two ends of the metal plate are bent into a curved shape to form a side plate 130.

[0070] After that, as Figure 9 As shown, a flat tank 100 comprising an upper plate 110, a lower plate 120, and a side plate 130 can be manufactured by welding the curved ends of a metal plate. The upper plate 110 has a first through hole 111 and a pump mounting hole 112 formed through the upper plate 110. The lower plate 120 has a second through hole 121 formed through the lower plate 120 at a position consistent with the first through hole 111 in the vertical direction. The side plate 130 integrally connects the two ends of the upper plate 110 and the lower plate 120.

[0071] Here, the baffle 160, the boss 170, etc. can be easily placed into the flat tank 100 through the front opening and the rear opening of the flat tank 100.

[0072] After that, as Figure 10 As shown, in the space between adjacent support pipes 150 to be installed in subsequent operations within the interior space of the flat tank 100, the upper and lower ends of a baffle 160 with fluid passage holes 162 are respectively welded to the lower surface of the upper plate 110 and the upper surface of the lower plate 120.

[0073] In addition, the boss portion 170, which is configured to ensure space for mounting the pump assembly 200, is welded to the pump mounting hole 112 of the upper plate 110, and two or more reinforcing blades 172, which are configured to support and protect the pump, are welded to the lower end of the boss portion 170 and the rib portion 125 of the lower plate 120.

[0074] Here, the reinforcing rib 174 can be further welded to two or more reinforcing blades 172, and the reinforcing steel pipe 176 can be welded to the lower surface of the upper plate 110 and the protruding rib 125 of the lower plate 120.

[0075] After that, as Figure 11 As shown, the end plate 140 is welded to the front and rear openings of the flat tank body 100.

[0076] After that, as Figure 12 As shown, a support tube 150 is inserted into the first through hole 111 of the upper plate 110 and the second through hole 121 of the lower plate 120, and then the support tube 150 is welded to the first through hole 111 of the upper plate 110 and the second through hole 121 of the lower plate 120. The support tube 150 is configured to connect the upper plate 110 and the lower plate 120 to each other and maintain the vertical spacing between the upper plate 110 and the lower plate 120.

[0077] That is, the outer diameter portion of the upper end of the support tube 150 is attached to and welded to the inner circumference of the first through hole 111, and the outer diameter portion of the lower end of the support tube 150 is attached to and welded to the inner circumference of the second through hole 121, thereby firmly supporting the upper plate 110 and the lower plate 120 and keeping the vertical distance between the upper plate 110 and the lower plate 120 constant.

[0078] Finally, the pump assembly 200 is assembled into the boss portion 170 and the reinforcing blade 172.

[0079] That is, when the pump assembly 200 is inserted into the flat tank 100 through the pump mounting hole 112 and installed in the convex rib 125 of the lower plate 120, the outer periphery of the pump assembly 200 can be supported by the boss 170 and the reinforcing blade 172.

[0080] Therefore, compared with conventional cylindrical or donut-shaped cans, low-profile flat cans with a low height and large area structure according to various exemplary embodiments of the present invention can be easily manufactured.

[0081] It is evident from the above description that the low-bottom flat tank for LPG storage and the method of manufacturing thereof according to various exemplary embodiments of the present invention are intended to provide the following effects.

[0082] First, the low-floor flat tank for LPG storage according to various exemplary embodiments of the present application has a flat structure of a rectangular shape, and thus can be easily installed at the floor of the vehicle body of a vehicle, thereby ensuring a large interior space and a large loading space of the vehicle.

[0083] Second, in a vehicle body having a reduced overall height and a downwardly adjusted center of gravity and including a floor of the vehicle body having a reduced height, the low-floor flat tank for LPG storage according to various exemplary embodiments of the present application can be easily installed at the floor of the vehicle body without being limited by space.

[0084] For convenience of explanation and accurate definition in the appended claims, the features of the exemplary embodiments shown in the drawings are described using the terms "upper", "lower", "inner", "outer", "up", "down", "upward", "downward", "front", "rear", "rear", "inner", "outer", "inward", "outward", "inner", "outer", "inside", "outside", "forward" and "backward" with reference to the positions of the features. It will be further understood that the term "connection" or its derivatives refers to both direct and indirect connections.

[0085] The foregoing description of specific exemplary embodiments of the application has been presented for the purposes of illustration and description. It is not intended to be exhaustive or to limit the application to the precise forms disclosed, and obviously many modifications and variations are possible in light of the above teachings. The exemplary embodiments were chosen and described in order to explain certain principles of the application and its practical application, to thereby enable others skilled in the art to best utilize the application and various embodiments with various modifications as are suited to the particular use contemplated. It is intended that the scope of the application be defined by the claims appended hereto, and their equivalents.

Claims

1. A low-bottom flat tank for storing liquefied petroleum gas (LPG), specifically a low-bottom flat tank for LPG storage, the low-bottom flat tank comprising: Flat tank, including: The upper plate has a plurality of first through holes and pump mounting holes formed through the upper plate; The lower plate has a plurality of second perforations formed through the lower plate at positions consistent with the plurality of first perforations in the vertical direction; and Side plate, integrally connecting the first and second side ends of the upper plate and the lower plate; End plates are installed at the front and rear openings of the flattened tank; and A support tube, the upper end of which is attached to the inner periphery of the plurality of first perforations and the lower end of which is attached to the inner periphery of the plurality of second perforations, to maintain the vertical distance between the upper plate and the lower plate.

2. The low-bottom flat tank according to claim 1, wherein, The upper plate and the lower plate are configured to have the same area and a longitudinal length greater than a transverse length, and the side plate and the end plate are bent to bulge outward and have the same height as the vertical distance between the upper plate and the lower plate.

3. The low-bottom flat tank according to claim 2, wherein, The longitudinal or transverse length of the upper plate and the lower plate is greater than the height of the side plate and the end plate.

4. The low-bottom flat tank according to claim 1, wherein, The inner periphery of each of the plurality of first perforations and the plurality of second perforations is formed with a flange that bends inward toward the interior of the flat can body to attach to each support tube.

5. The low-chassis flat tank according to claim 4, further comprising: The concave valley is located in the contact area between the outer diameter portion of the upper end of the support tube and the flange portion of the inner circumference of the plurality of first perforations, and in the contact area between the outer diameter portion of the lower end of the support tube and the flange portion of the inner circumference of the plurality of second perforations.

6. The low-bottom flat tank according to claim 1, wherein, Multiple baffles are disposed between the support tubes inside the flat tank, and the multiple baffles have fluid passage holes formed through the multiple baffles. The upper and lower ends of each of the plurality of baffles are respectively attached to the upper plate and the lower plate.

7. The low-bottom flat tank according to claim 6, wherein, Each of the plurality of baffles is bent at a specified angle to reduce and disperse stress concentrated in the space between adjacent support tubes in the flat tank.

8. The low-bottom flat tank according to claim 7, wherein, Each of the plurality of baffles is configured such that the length and area of ​​the portion of each of the plurality of baffles attached to the upper plate and the lower plate are maximized.

9. The low-bottom flat tank according to claim 1, wherein, A rib protruding into the interior of the flat tank is formed on the lower plate at a position consistent with the pump mounting hole on the upper plate in the vertical direction.

10. The low-bottom flat tank according to claim 9, wherein, Ensure that the boss portion of the space for installing the pump is attached to the pump mounting hole on the upper plate.

11. The low-chassis flat tank according to claim 10, wherein, At least two reinforcing blades of the pump are supported and protected by connecting to the lower end of the boss portion of the pump mounting hole attached to the upper plate and the convex rib portion of the lower plate.

12. The low-chassis flat tank according to claim 11, wherein, The reinforcing ribs are connected to the at least two reinforcing blades.

13. The low-bottom flat tank according to claim 9, wherein, The reinforcing tube for relieving local stress is located in the central region between the upper plate and the lower plate and is attached to the protruding ribs of the upper plate and the lower plate.

14. The low-chassis flat tank according to claim 1, wherein, Multiple mounting brackets, which are fixedly assembled with the vehicle body, are installed on the flat tank and the end plate.

15. A method for manufacturing a low-bottom flat tank for liquefied petroleum gas (LPG) storage, specifically a method for manufacturing a low-bottom flat tank for LPG storage, the method comprising: To manufacture a plate with a specified area; By using perforation and drawing processes, multiple first perforations and pump mounting holes are formed through one side of the plate body serving as the upper plate, while multiple second perforations are formed through the other side of the plate body serving as the lower plate. The first and second side ends of the plate are bent to form side plates; A flat tank comprising an upper plate, a lower plate, and side plates is manufactured by welding the bent first side end and the bent second side end of the plate body. The upper plate has a plurality of first through holes and a pump mounting hole formed through the upper plate. The lower plate has a plurality of second through holes formed through the lower plate at positions consistent with the plurality of first through holes in the vertical direction. The side plates integrally connect the first side end and the second side end of the upper plate and the lower plate. The end plates are welded to the front and rear openings of the flat tank body; as well as The upper end of the support tube is welded to the inner circumference of the plurality of first perforations, and the lower end of the support tube is welded to the inner circumference of the plurality of second perforations. The support tube connects the upper plate and the lower plate to each other and maintains the vertical distance between the upper plate and the lower plate.

16. The method of claim 15, further comprising, prior to welding the end plate to the front opening and the rear opening: Inside the flat tank, in the space between adjacent support pipes, the upper and lower ends of a baffle with fluid passage holes are welded to the upper and lower plates.

17. The method of claim 15, further comprising, prior to welding the end plate to the front opening and the rear opening: The boss portion that ensures space for pump installation is welded to the pump mounting hole on the upper plate, and at least two reinforcing blades that support and protect the pump are welded to the boss portion and the lower plate.

18. The method of claim 17, further comprising: The pump assembly is assembled into the boss portion and the at least two reinforcing blades.

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