Fuel cell case

Abstract

To prevent breakage of a fuel cell case.SOLUTION: The fuel cell case houses a large number of fuel cells 10 inside. A case main body 12 assembled by joining a lower end of an upper case side 12a and an upper end of a lower case side 12b at a joining portion 14, and a protector 20 including an upper fastening portion side 12a fastened to an outer surface of the upper case side 20a, a lower fastening portion side 12b fastened to an outer surface of the lower case side 20b, and a bulging portion side 20c located between the upper fastening portion and the lower fastening portion and covering the joining portion 14 at an interval from the joining portion 14, A portion of the upper case side 20a to which the upper fastening portion side 12a is fastened and a portion of the lower case side 20b to which the lower fastening portion side 12b is fastened may be thicker than other portions.SELECTED DRAWING: Figure 2

Description

[Technical Field]

[0001] The present disclosure relates to a fuel cell case that houses a large number of fuel cell units therein. [Background technology]

[0002] Fuel cell vehicles are known in the past, and run by driving a motor with electricity generated by oxidizing hydrogen gas in a fuel cell. However, a large amount of electricity is required to run the vehicle, and the necessary power is obtained by preparing a fuel cell stack, which is made up of many stacked fuel cell cells that generate small amounts of electricity.

[0003] As mentioned above, a fuel cell stack generates a large amount of power, and safety is ensured by providing a fuel cell case that forms the outer wall. For example, Patent Document 1 shows a fuel cell case that is divided into upper and lower halves. [Prior art documents] [Patent documents]

[0004] [Patent Document 1] Japanese Patent Application Laid-Open No. 2006-196386 Summary of the Invention [Problem to be solved by the invention]

[0005] In fuel cell vehicles, the fuel cell case is often housed in a front compartment at the front of the vehicle, which also houses various electrical components, making it difficult to secure a large space around the fuel cell case.

[0006] Therefore, there are cases where the fuel cell case is placed close to other components. In such cases, for example, in the event of a frontal collision of the vehicle, there is a possibility that a component moving from the front will collide with the fuel cell case. For this reason, there is a demand for means to prevent damage to the fuel cell case as effectively as possible. [Means for solving the problem]

[0007] The fuel cell case of the present disclosure is a fuel cell case that houses a large number of fuel cell cells inside, and includes a case main body that is assembled by joining the lower end of an upper case and the upper end of a lower case at a joint, and a protector that includes an upper fastening portion that is fastened to the outer surface of the upper case, a lower fastening portion that is fastened to the outer surface of the lower case, and a bulge portion that is intermediate the upper fastening portion and the lower fastening portion and covers the joint with a gap between them, and the portion of the upper case to which the upper fastening portion is fastened and the portion of the lower case to which the lower fastening portion is fastened are thicker than other portions.

[0008] The joints may be located on the outer surfaces of the upper case and the lower case, and there may be unjoined portions on the inner surfaces of the upper and lower cases where the upper ends of the upper and lower cases are not joined. [Effects of the Invention]

[0009] According to the present invention, when a member moving from the front collides with the fuel cell case, the protector can change the position to which the impact is applied, thereby preventing damage to the fuel cell case. [Brief explanation of the drawings]

[0010] [Figure 1] FIG. 2 is a perspective view showing a schematic configuration of a fuel cell case. [Figure 2] FIG. 1 is a partial perspective view showing the configuration of a joint 14, illustrating the cross-sectional configuration of one side wall of the upper case and the lower case. [Figure 3] 1A and 1B are schematic diagrams showing the state of a vehicle during a collision, where (A) shows the state without a protector and (B) shows the state with a protector. [Figure 4] 10A and 10B are diagrams showing two modified examples of the case body. [Figure 5] 10A and 10B are diagrams showing an example of a front configuration of a thick portion of a case main body. [Figure 6] 2 is a cross-sectional view showing an example of the configuration of a protector 20. FIG. DETAILED DESCRIPTION OF THE INVENTION

[0011] Hereinafter, embodiments of the present disclosure will be described with reference to the drawings. Note that the following embodiments do not limit the present disclosure, and configurations formed by selectively combining multiple examples are also included in the present disclosure.

[0012] "Configuration of fuel cell case" FIG. 1 is a perspective view showing the schematic configuration of a fuel cell case 100. A cell stack 10, in which multiple fuel cells are stacked, is housed in the internal space of a case body 12. The fuel cell case body 12 is divided into two parts: an upper case 12a and a lower case 12b. Both the upper case 12a and the lower case 12b are rectangular frames made up of four side walls. The lower end surface of the upper case 12a and the upper end surface of the lower case 12b are substantially identical in shape, allowing them to overlap. The top surface of the upper case 12a and the bottom surface of the lower case 12b can be closed with plate-shaped top and bottom members, respectively, forming a sealed box. The fuel cell stack 10 requires gases such as fuel gas and oxidizing gas, as well as wiring for outputting power, which pass through the case body 12 and are connected to the fuel cell stack 10. The cell stack 10 or a fuel cell case housing the cell stack 10 is sometimes called a fuel cell stack.

[0013] In this example, the lower end surface of the upper case 12a and the upper end surface of the lower case 12b are overlapped to form a joint 14, and the two are joined together at this joint 14 by friction stir welding.

[0014] A protector 20 is attached to the side of the case body 12 that corresponds to the front of the vehicle. In this example, the protector 20 is provided only on the front side of the case body 12, on the assumption that a member moving from the front in a frontal collision of the vehicle will collide with the case body 12, but the protector 20 may be provided on other sides or all sides.

[0015] The protector 20 is a rectangular plate material with a C-shaped cross section as a whole. That is, it has an upper fastening portion 20a at its upper end, which is a strip-shaped region fastened to the outer surface of the upper case 12a, and a lower fastening portion 20b at its lower end, which is a strip-shaped region fastened to the outer surface of the lower case 12b. The upper fastening portion 20a and the lower fastening portion 20b are fastened to the outer surface of the case body 12 by bolting. In the drawing, the fastening points by bolting are indicated by circles. Note that the fastening means is not limited to bolting, and adhesive bonding, welding, etc. may also be used.

[0016] The middle portion between the upper fastening portion 20a and the lower fastening portion 20b bulges outwardly from the joint portion 14 of the case body 12 to form a bulging portion 20c. In other words, the bulging portion 20c covers the joint portion 14 from the outer surface with a distance D therebetween.

[0017] "Configuration of joints" 2 is a partial perspective view showing the configuration of joint 14, illustrating the cross-sectional configuration of one side wall of upper case 12a and lower case 12b. In this example, upper case 12a is placed on top of lower case 12b and joined at joint 14 where the two come into contact. Here, in this example, upper case 12a and lower case 12b are joined by friction stir welding as described above.

[0018] This friction stir welding is performed by pressing a tool against the joint 14 from the outside and rotating it. Therefore, the lower end of the upper case 12a and the vicinity of the contact surface of the lower case 12b are integrated, but this integration progresses from the outside to the inside. In this example, the upper case 12a and the lower case 12b are quite thick, making it difficult to integrate them all the way to the end on the inner surface side. For this reason, as shown by the oval in the figure, an integrated actual joint A is formed on the outer surface side, while an unintegrated unjoined part B remains on the inner surface side. Because the unjoined part B is not integrated, it basically has no resistance to a force in the direction in which the two parts move apart.

[0019] In the illustrated example, the upper case 12a and the lower case 12b are not flat plates but have an E-shaped cross section, with increased thicknesses at three locations: the upper end, the lower end, and the middle. In other words, the formation of two upper and lower recesses increases the thicknesses at the upper end, the lower end, and the middle. The thicker portion of the middle is called a thick portion C. The upper fastening portion 20a and the lower fastening portion 20b of the protector 20 are fastened to the outer surfaces of the thick portions C of the upper case 12a and the lower case 12b, respectively. Therefore, the fastened portions are less likely to deform than the adjacent portions above and below, preventing the protector 20 from peeling off due to an impact such as a collision.

[0020] "Effects during collision" Figure 3 is a schematic diagram showing the state during a collision. Figure 3(A) shows the case without the protector 20. Without the protector 20, when an impact is applied from the outside to the joint 14, a tensile force (an input in the direction of separating the joint) is applied to the unjoined portion B on the inside of the joint 14. This causes a stress to be applied that separates the inside portion of the joint 14, with the outside portion of the joint 14 as a fulcrum, as shown in the figure. This type of stress concentration could cause the case body 12 to break at about one-third of the yield strength of the original material (base material) of the case body 12.

[0021] FIG. 3(B) shows a case where a protector 20 is included. When the protector 20 is included, the impact is first applied to the protector 20, thereby preventing the impact from being directly applied to the joint 14. Furthermore, the protector 20 transmits the applied impact to the thick portions C of the upper case 12a and the lower case 12b via the upper fastening portion 20a and the lower fastening portion 20b, respectively. Therefore, as shown in the figure, the transmission of the impact can be controlled so that the unjoined portion B receives a compressive input rather than a tensile input, effectively preventing damage to the case body 12. In particular, because the impact is applied to the thick portion C, damage to the case body 12 can be efficiently prevented.

[0022] "Variations" Figure 4 shows two modified examples of the case body 12. In Figure 4(A), the upper case 12a and the lower case 12b have two recesses, one above the other, formed on their outer surfaces, forming thick portions C that protrude outward. In Figure 4(B), the thick portions C of the upper case 12a and the lower case 12b protrude both outward and inward.

[0023] In this configuration, similarly to the configuration of FIG. 2, the thick portion C can absorb the impact from the protector 20, and the case body 12 can be efficiently prevented from being broken.

[0024] 5A and 5B are diagrams showing the front configuration of the thick portion C of the case body 12. In the example of FIG. 5A, the thick portion C is a strip-shaped protrusion in the lateral direction (left-right direction) of the case body 12. In the example of FIG. 5B, the thick portion C is a rod-shaped protrusion formed discretely in the lateral direction (left-right direction) of the case body 12. In either configuration, it is possible to absorb an impact from the protector 20.

[0025] Fig. 6 is a cross-sectional view showing an example of the configuration of the protector 20. In Fig. 5(A), as shown in Figs. 2 and 4, the bulging portion 20c is formed as a stepped protrusion with a gentle periphery. In Fig. 5(B), the bulging portion is triangular-shaped, and in Fig. 5(C), the bulging portion 20c is a stepped protrusion with a periphery rising at a right angle. In either case, the impact can be transmitted to the thick portion C. [Explanation of symbols]

[0026] 10 cell stack, 12 case body, 12 fuel case body, 12a upper case, 12b lower case, 14 joint, 20 protector, 20a upper fastening portion, 20b lower fastening portion, 20c bulge portion, 100 fuel cell case.

Claims

1. A fuel cell case that houses a large number of fuel cell cells therein, a case main body assembled by joining a lower end of the upper case and an upper end of the lower case at a joint; a protector including an upper fastening portion fastened to an outer surface of the upper case, a lower fastening portion fastened to an outer surface of the lower case, and a bulge portion intermediate the upper fastening portion and the lower fastening portion, the bulge portion covering the joint portion at a distance from the joint portion; Including, a portion of the upper case to which the upper fastening portion is fastened and a portion of the lower case to which the lower fastening portion is fastened are thicker than other portions; Fuel cell case.

2. 2. The fuel cell case according to claim 1, the joints are located on the outer surfaces of the upper case and the lower case, and an unjoined portion exists on the inner surface between the upper end of the upper case and the upper end of the lower case. Fuel cell case.

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