Power receiving equipment and disc spring washers

Abstract

The enclosure is easy to assemble, yet the electrical conductivity between the metal plates is firmly maintained even when installed in an environment subject to mechanical stress. [Solution] The first disc spring washer (40A) and the second disc spring washer (40B) of the fastening portion (2) of the housing of the power receiving equipment have a plurality of conical projections (43) arranged along the outer circumference and protruding from the surface, and when the fastening portion fastens the two metal plates (12A, 12B), the tips of the conical projections pierce the coating (121) of the metal plates and reach the metal part.

Description

Technical Field

[0001] The present invention relates to power receiving equipment and a disc spring washer applicable to the power receiving equipment.

Background Art

[0002] Power receiving equipment that houses various power receiving devices is known. The outer shell of the housing of the power receiving equipment is configured by combining a plurality of metal plates. A coating film is formed on the surface of such a metal plate for rust prevention.

Prior Art Documents

Patent Documents

[0003] [[ID= twenty-three]]

Patent Document 1

Summary of the Invention

Problems to be Solved by the Invention

[0004] For ensuring safety or suppressing the radiation of electromagnetic noise to the outside, the metal plates constituting the outer shell of the housing need to be electrically connected to each other and grounded. However, since a coating film is formed on the surface of the metal plates, some contrivance is necessary to electrically connect the metal plates to each other. In particular, in power receiving equipment installed in an environment where mechanical stress such as vibration is applied, it is not always easy to maintain the state in which the metal plates are electrically connected to each other.

[0005] The present invention has been made in view of the above problems, and an object thereof is to realize power receiving equipment that is easy to assemble the housing and can firmly maintain the state in which the metal plates are electrically connected to each other even when installed in an environment where mechanical stress is applied.

Means for Solving the Problems

[0006] To solve the above problems, a power receiving device according to one aspect of the present invention is a power receiving device comprising a housing composed of a plurality of metal plates having a coating film formed on their surface, wherein in a region where two of the metal plates overlap each other, a fastening portion is provided for fastening the two metal plates, the fastening portion comprising a bolt inserted into a through hole connecting the two metal plates and a nut screwed onto the bolt, the fastening portion further comprising a first disc spring washer positioned on the head side of the bolt and a second disc spring washer positioned on the nut side, the first disc spring washer and the second disc spring washer each having a plurality of conical projections arranged along their outer circumference and protruding from the surface on the two metal plates, and the fastening portion fastens the two metal plates, the tip of the conical projection of the first disc spring washer and the second disc spring washer each piercing the coating film on the metal plates and reaching the metal portion.

[0007] One aspect of the present invention is a disc spring washer having a circular outer circumference, and comprising a plurality of conical projections along the outer circumference that protrude from the side facing the fastened object toward the fastened object. [Effects of the Invention]

[0008] According to any of the above embodiments of the present invention, it is possible to realize a power receiving device in which the housing is easy to assemble, and in which the electrical conductivity between metal plates is firmly maintained even when installed in an environment where mechanical stress is applied. [Brief explanation of the drawing]

[0009] [Figure 1] This is an external view showing an overview of a power receiving equipment according to an embodiment of the present invention. [Figure 2] This figure shows a situation in which metal plates constituting the housing of a power receiving equipment according to an embodiment of the present invention are fastened together by fastening parts in a region where two plates are superimposed. [Figure 3] This is a cross-sectional view of a disc spring washer, which is a fastening part applied to a power receiving equipment according to an embodiment of the present invention. [Figure 4]This is a bottom view of a disc spring washer, which is a fastening part applied to a power receiving equipment according to an embodiment of the present invention. [Modes for carrying out the invention]

[0010] [Embodiment] An embodiment of the present invention will be described in detail below with reference to Figures 1 to 4. The power receiving equipment 10 according to this embodiment is equipment that houses various devices for receiving power. Equipment referred to as a switchgear and equipment referred to as a cubicle correspond to the power receiving equipment 10 according to the present invention.

[0011] Figure 1 is an external view showing an overview of a power receiving equipment 10 according to an embodiment of the present invention. The power receiving equipment 10 includes a housing 11. The housing 11 is formed by appropriately fixing a plurality of metal plates 12 to a metal frame, for example, and by appropriately fixing the plurality of metal plates 12 to each other. Thus, the outer shell of the housing 11 is composed of a plurality of metal plates 12. At least both sides of these metal plates 12 are painted to prevent rust, and a coating 121 is formed on both sides of the metal plates 12.

[0012] Figure 2 is a cross-sectional view of a region in the housing of the power receiving equipment 10 where two metal plates 12, metal plate 12A and metal plate 12B, are overlapped. In this region where the two metal plates 12 are overlapped, through holes 122 are appropriately formed to connect metal plate 12A and metal plate 12B. The shaft portion 21 of a bolt 20 is inserted into the through hole 122, and together with a nut 30 that is screwed onto the shaft portion 21 of the bolt 20, a fastening portion 2 is formed. The fastening portion 2 fastens and fixes metal plate 12A and metal plate 12B to each other.

[0013] The fastening portion 2 further includes a distinctive disc spring washer 40A (first disc spring washer) positioned on the head 22 side of the bolt 20, and a distinctive disc spring washer 40B (second disc spring washer) positioned on the nut 30 side. The disc spring washer 40A and the disc spring washer 40B have the same configuration. With the fastening portion 2 fastening and fixing the metal plate 12A and the metal plate 12B, the head 22 of the bolt 20, the disc spring washer 40A, the metal plate 12A, the metal plate 12B, the disc spring washer 40B, and the nut 30 are arranged in order along the axial direction of the bolt 20.

[0014] Figure 3 is a cross-sectional view showing a characteristic disc spring washer according to the present invention, either disc spring washer 40A or disc spring washer 40B. Figure 4 is a bottom view showing disc spring washer 40A or disc spring washer 40B. The bottom view of Figure 4 is a view from the side where disc spring washer 40A or disc spring washer 40B abuts against the fastened object, i.e., metal plate 12A or metal plate 12B. Figure 3 is a cross-sectional view at position XX in Figure 4.

[0015] The structure of the disc spring washer 40A will be described below, but as mentioned above, the disc spring washer 40B has the same structure. The entire disc spring washer 40A is conductive and made of a single piece of metal. The main body 42 of the disc spring washer 40A is ring-shaped in plan view. The hole 41 in the center of the ring for inserting the shaft of the bolt 20 is circular. The outer circumference of the main body 42 is circular.

[0016] The main body portion 42 is umbrella-shaped, with a plate-like structure that is slightly inclined in the axial direction from a surface perpendicular to the axial direction, in order to generate an axial biasing force as a disc spring when compressed in the axial direction. Of the pair of faces of the umbrella-shaped plate-like main body portion 42, the inner face is the face facing the object to be fastened, and the outer face is the opposite side, i.e., the face facing the head 22 of the bolt 20 or the nut 30.

[0017] On the disc spring washer 40A, on the side of the main body 42 that is fastened to the object, i.e., the side of the metal plate 12A, A plurality of conical protrusions 43 are provided which protrude from the surface and are arranged along the outer periphery of the main body portion 42. The conical protrusions 43 are, for example, conical in shape, but may also be triangular pyramid shape, hexagonal pyramid shape, or other pyramid shapes.

[0018] As shown in FIG. 2, in a state where the fastening portion 2 fastens and fixes the metal plate 12A and the metal plate 12B, the tip of the conical protrusion 43 of the disc spring washer 40A has pierced through the coating film of the metal plate 12A and reached the metal portion. Therefore, the conductive metal portion of the metal plate 12A is electrically connected to the bolt 20 via the disc spring washer 40A.

[0019] In addition, in a state where the fastening portion 2 fastens and fixes the metal plate 12A and the metal plate 12B, the tip of the conical protrusion 43 of the disc spring washer 40B has pierced through the coating film of the metal plate 12B and reached the metal portion. Therefore, the conductive metal portion of the metal plate 12B is electrically connected to the bolt 20 via the disc spring washer 40B. In this way, the metal plate 12A and the metal plate 12B are in an electrically connected state. Also, in FIG. 2, the inclination of the main body portion 42 of the disc spring washer 40A and the disc spring washer 40B is emphasized and drawn.

[0020] The fastening and fixing of the metal plate 12A and the metal plate 12B by the fastening portion 2 was released, and the disc spring washer 40A was removed from the metal plate 12A. Then, on the metal plate 12A, dot-shaped holes corresponding to the conical protrusions 43 of the disc spring washer 40A were formed in a ring shape. The holes formed in the metal plate 12A by the piercing of the conical protrusions 43 in this way are dot-shaped, and no widened scratches such as those caused by the rotation of the disc spring washer 40A during bolt fastening were seen. The same situation was true for the metal plate 12B.

[0021] According to the present embodiment, each conical protrusion 43 of the disc spring washer 40A and the disc spring washer 40B is provided on the surface of the main body portion 42, and its form is conical. Therefore, when the fastening portion 2 is fastened, each conical protrusion 43 is pushed into the metal plate 12A and the metal plate 12B without the disc spring washer 40A and the disc spring washer 40B rotating.

[0022] Furthermore, when fastening, the pressure is concentrated on each conical projection 43, causing each conical projection 43 to be strongly pressed into the metal plates 12A and 12B, creating point-like holes. In this way, according to this embodiment, the conical projections 43 can reliably penetrate the coatings of the respective metal plates 12A and 12B, ensuring electrical conductivity.

[0023] A corrosion test was conducted on the housing 11 of the power receiving equipment 10 as follows: The housing 11 was installed outdoors for two months, exposed to rain, and periodically sprayed with salt water. The fastening of metal plates 12A and 12B by the fastening part 2 was released, and the condition of the point-like holes formed by the conical projection 43 and the surrounding area was checked. No rust was observed. Thus, according to this embodiment, it was considered that the coatings of metal plates 12A and 12B were not damaged excessively during fastening, and since there were no exposed damaged areas, rust did not occur.

[0024] A vibration test was performed on the housing 11 of the power receiving equipment 10 as follows: The area where metal plates 12A and 12B overlapped was repeatedly vibrated using a vibration testing machine. As Comparative Example 1, toothed washers were used to fasten the metal plates together instead of disc spring washers 40A and 40B. As toothed washers, those having inwardly or outwardly facing teeth that bite into the metal plates were tested.

[0025] A toothed washer with outward-facing teeth is a washer with a ring-shaped body and multiple petal-shaped teeth that bite into the object to be fastened; it is also called a chrysanthemum washer. A toothed washer with inward-facing teeth is a washer with a ring-shaped body and teeth that bite into the object to be fastened, oriented along the central axis.

[0026] In the housing of Comparative Example 1, regardless of whether the toothed washer had outward-facing teeth or inward-facing teeth, the toothed washer fractured at a number of vibrations that did not cause damage to the disc spring washer 40A and disc spring washer 40B of this embodiment. The disc spring washer 40A and disc spring washer 40B according to this embodiment have a ring-shaped main body portion 42 with a circular outer and inner circumference, and are provided with conical projections 43 for biting into the fastened object. Since the disc spring washer 40A and disc spring washer 40B do not have a notched shape like a toothed washer, it was confirmed that they have higher resistance to mechanical stress than a toothed washer.

[0027] As Comparative Example 2, a housing was tested in which metal plates were fastened using a flat washer with multiple conical protrusions, in which the main body 42 was replaced with a flat plate, instead of the disc spring washer 40A and disc spring washer 40B. In the housing of Comparative Example 2, the fastening between the metal plates loosened at a vibration frequency that would not cause loosening with the fastening part 2 of this embodiment. It is thought that because the washer in Comparative Example 2 does not have a disc spring structure, no biasing force is generated after fastening, and the bolt / nut fastening loosened due to vibration.

[0028] Thus, according to this embodiment, even when installed in an environment where mechanical stress is applied, the fastening between the metal plates does not loosen and the occurrence of rust is suppressed, thereby realizing power receiving equipment that maintains electrical conductivity between the metal plates. Examples of environments where such mechanical stress is applied include factories with vibration sources and transportation facilities such as bridges.

[0029] Furthermore, pressure fluctuations repeatedly occur in railway and road tunnels due to the passage of vehicles, and power receiving equipment installed in such environments is subjected to mechanical stress due to the expansion and compression of the outer casing caused by these pressure fluctuations. The power receiving equipment 10 according to this embodiment is also suitable for use as power receiving equipment installed in such environments. Moreover, in this embodiment, by applying the fastening part 2 to the assembly of metal plates, electrical conductivity can be established between the metal plates at the same time, making it easy to assemble the casing 11 of the power receiving equipment 10.

[0030] 〔summary〕 One aspect of the present invention is a power receiving device comprising a housing composed of a plurality of metal plates having a coating film formed on their surfaces, wherein in a region where two of the metal plates overlap each other, a fastening portion is provided for fastening the two metal plates, the fastening portion comprising a bolt inserted into a through hole connecting the two metal plates and a nut screwed onto the bolt, the fastening portion further comprising a first disc spring washer positioned on the head side of the bolt and a second disc spring washer positioned on the nut side, the first disc spring washer and the second disc spring washer each having a plurality of conical projections arranged along their outer circumference and protruding from the surfaces on the two metal plates, and when the fastening portion fastens the two metal plates, the tips of the conical projections of the first disc spring washer and the second disc spring washer each penetrate the coating film on the metal plates and reach the metal portion.

[0031] The power receiving equipment according to embodiment 2 of the present invention is characterized in that, in embodiment 1, the outer circumference of the first disc spring washer and the second disc spring washer are circular.

[0032] The power receiving equipment according to embodiment 3 of the present invention is characterized in that it is installed inside a tunnel in embodiment 1 or 2 described above.

[0033] A fourth aspect of the present invention is a disc spring washer having a circular outer circumference, comprising a plurality of conical projections along the outer circumference that protrude from the side facing the object to be fastened toward the object to be fastened.

[0034] The present invention is not limited to the embodiments described above, but rather to various embodiments within the scope of the claims. The invention is also technically within the scope of the present invention, and embodiments obtained by appropriately combining the technical means disclosed in each embodiment are also subject to modification. [Explanation of symbols]

[0035] 10 Power receiving equipment 11 cabinets 12(12A, 12B) Metal plate 121 Coating 122 Through hole 2 Fastening part 20 volts 21 Shaft 22 Head 30 nuts 40A, 40B Disc spring washer 41 Hole 42 Main body 43 Each cone

Claims

1. A power receiving device comprising a housing that includes multiple metal plates on which a coating film is formed on the surface, In the region where the two metal plates of the housing overlap each other, A fastening mechanism is provided for fastening the two metal plates, which includes a bolt inserted into a through hole connecting the two metal plates and a nut screwed onto the bolt. The fastening portion further includes a first disc spring washer positioned on the head side of the bolt and a second disc spring washer positioned on the nut side. Each of the first and second disc spring washers has a plurality of conical projections arranged along its outer circumference and protruding from the surfaces of the two metal plates. In a state where the fastening portion fastens the two metal plates, the tips of the conical projections of the first and second disc spring washers penetrate the coating on the metal plates and reach the metal portion, in a power receiving device.

2. The power receiving equipment according to claim 1, wherein the outer circumference of the first disc spring washer and the second disc spring washer are circular in shape.

3. The power receiving equipment according to claim 1 or 2, characterized in that it is installed inside a tunnel.

4. A disc spring washer whose outer circumference is circular, A disc spring washer having multiple conical projections along its outer circumference that protrude from the side facing the object to be fastened toward the object to be fastened.

Images