JP3000305U - Washer for preventing electrolytic corrosion - Google Patents

Abstract

(57) [Summary] [Purpose] To provide a washer for preventing electrolytic corrosion that integrates a washer made of metal and a washer made of an insulator to improve the efficiency of the assembling work and prevent mistakes during assembling as much as possible thing. [Structure] A seat surface portion 4 in which a hole 2a for inserting a bolt is formed in a central portion of a disk-shaped stainless steel plate, and an annular protrusion (engagement that rises from the peripheral edge of the seat surface portion 4 and engages with the peripheral surface of the insulating washer 3). Part) 5 and a disk-shaped glass fiber reinforced plastic plate having a hole 3a for inserting a bolt in the center thereof and an outer diameter slightly smaller than the inner diameter of the annular protrusion 5. The insulating washer 3 and the insulating washer 3 are integrated by fitting.

Description

[Detailed description of the device]

[0001]

[Industrial applications]

 The present invention, for example, in piping, when connecting one pipe body and the other pipe body with bolts and nuts, interposes between the flanges of these pipe bodies and the bearing surfaces of the bolts and nuts, and The present invention relates to a washer for preventing electrolytic corrosion that can prevent electrical corrosion by insulating it from bolts and nuts.

[0002]

[Prior art]

 Conventionally, in piping, in order to connect one pipe body to the other pipe body, a flange is provided at the end edge of the pipe body, and a thickness is provided between the flange of one pipe body and the flange of the other pipe body. With an insulating gasket of about 3 mm to 6 mm interposed between the flange of one pipe and the seat surface of the bolt head, and between the flange of the other pipe and the seat surface of the nut, use metal such as stainless steel. There is known a method in which a bolt is inserted into a through hole formed in the flanges of both pipes with a washer interposed therebetween, and then a nut is screwed to the bolt and tightened to connect both pipes.

By the way, in the case where the pipes are connected using the bolts and nuts as described above, if the fluid flowing inside the pipes after the completion of the pipe is an electrolyte, the flanges of the pipes may change with time. Electrochemical corrosion may occur between bolts and nuts. That is, if the pipe flange and the bolts and nuts are made of different metals, when they are immersed in the electrolyte fluid, a battery is formed due to the difference in the electrode potentials of these different metals, and electrochemical corrosion occurs. Occurs. When such electrochemical corrosion occurs, durability of bolts and nuts is significantly reduced, and the breaking of the bolts may break the connection of the pipes and cause leakage of fluid flowing in the pipes.

In order to solve the inconvenience caused by such electrochemical corrosion, conventionally, the surface of the shaft portion from the end of the screw formed at the tip of the bolt to the head of the bolt is coated with an insulating material such as a synthetic polymer material. At the same time, a washer made of an electrical insulator is further interposed between the washer and the flange of the pipe body, and the coating and the washer made of the electrical insulator separate the flange of the pipe body from the bolt / nut and the washer made of stainless steel. It prevented direct contact.

[0005]

[Problems to be solved by the device]

 However, connecting the pipes by using the bolts and nuts as in the above-mentioned conventional case has the following disadvantages. In other words, the two types of washers, that is, those made of metal and those made of electrical insulator, which are interposed between the flange of the pipe and the bolts and nuts, were actually configured separately, so the pipe was actually In the work of connecting the washer, four washers had to be interposed for one bolt and nut, and the work of assembling the washers required double the labor, which reduced the workability. .

Further, as a mistake at the time of assembling work, for example, when bolts and nuts are tightened without forgetting to insert a washer made of metal, the tightening strength of the bolts and nuts decreases, but the bolts and nuts are made of an electrical insulator. If the bolts and nuts are tightened without forgetting to insert the washers, the flange of the pipe and the bolts and nuts will be connected via a metal washer without being insulated. Induces electrochemical corrosion.

The present invention can solve the above problems, and an object thereof is to integrate a washer made of a metal and a washer made of an electrical insulator so that the assembling work can be performed efficiently and the assembling work can be performed. It is to provide a washer for preventing electrolytic corrosion that can prevent mistakes as much as possible.

[0008]

[Means for Solving the Problems]

 Among the washer for preventing electrolytic corrosion according to the present invention, the washer according to claim 1 comprises a washer made of metal and a washer made of an electric insulator attached so as to cover at least one seat surface of the washer. It is characterized by being integrated. According to a second aspect of the present invention, a washer made of a metal and a washer made of an electric insulator are integrated, and one washer made of the metal and the washer made of the electric insulator are A washer that covers one of the washer surfaces and an engaging portion that rises from this washer and engages with the peripheral surface of the other washer, and this one washer is fitted onto the other washer. It is characterized by doing.

According to a third aspect of the present invention, a washer made of a metal and a washer made of an electrical insulator are integrated, and the washer made of the metal and the washer made of the electrical insulator are one washer. Is a seat surface portion that covers one seat surface of the other washer, and an engaging portion that rises from the seat surface portion and engages with the peripheral surface of the other washer, and the other washer is It is characterized by comprising a small-diameter portion which is fitted inside the engaging portion of one washer, and a large-diameter portion which is continuous with the small-diameter portion and has the same diameter as the outer diameter of the seat surface portion of the one washer. .

[0010]

[Action]

 Among the washers for preventing electrolytic corrosion of the present invention, according to claim 1, a washer made of metal and a washer made of an electric insulator attached so as to cover at least one seat surface of the washer are provided. , Are integrated so that the washer made of metal and the washer made of an electrical insulator can be used in the assembly work in which the electrolytic corrosion washer is interposed between the bolt / nut and the tightening portion such as the flange of the pipe body. They can be assembled at the same time, improving workability, and never forget to install one of the metal washer and the washer made of electrical insulator. In order to integrate the washer made of metal and the washer made of an electrical insulator, it is easy to attach both with an adhesive, for example.

According to the second aspect of the present invention, the washer made of metal and the washer made of an electrical insulator include a seat surface portion where one washer covers one seat surface of the other washer, and the seat surface portion. And a metal washer and an electric wire similar to the above, by engaging the one washer with the other washer. The washer made of an insulator can be assembled at the same time at the same time, and one of the washers made of metal or the washer made of electric insulator can be remembered. Further, since the one washer and the other washer can be integrated by fitting, it is possible to easily form the electrolytic corrosion preventing washer.

According to the third aspect of the present invention, the washer made of metal and the washer made of an electrical insulator include a seat surface portion where one washer covers one seat surface of the other washer, and the seat surface portion. An engaging portion that rises up from and engages with the peripheral surface of the other washer, and the other washer has a small diameter portion that fits inside the engaging portion of the one washer and a small diameter portion. A large diameter portion that is continuous and has the same diameter as the outside diameter of the seat surface portion of the one washer. As a result, a metal washer and a washer made of an electric insulator can be simultaneously assembled at one time, and one of the washer made of metal and the washer made of an electric insulator can be remembered. Further, since the one washer and the other washer can be integrated by fitting, it is possible to easily form the electrolytic corrosion preventing washer.

[0013]

【Example】

 Hereinafter, embodiments of the present invention will be described in detail with reference to the drawings. 1 to 5 show an embodiment of the present invention. Of these drawings, FIG. 1 is a front view of an electrolytic corrosion washer 1, and FIG. 2 is a sectional view taken along line XX of FIG. It is a figure. The washer 1 for preventing electrolytic corrosion is formed by integrating a metal washer 2 made of metal such as stainless steel and an insulating washer 3 made of glass fiber reinforced plastic. The metal washer 2 has a hole 4a for inserting a bolt formed in the center of a disk-shaped metal plate to form a seat surface portion 4, and rises from the periphery of the seat surface portion 4 to engage with the peripheral surface of the insulating washer 3. A ring-shaped projection (engaging portion) 5 to be fitted is provided. On the other hand, the insulating washer 3 has a hole 3a for inserting a bolt formed in the center of a disk, and its outer diameter is slightly smaller than the inner diameter of the annular projection 5. Then, the metal washer 2 is externally fitted to one seat surface of the insulating washer 3 from the side where the annular protrusion 5 is provided, and the metal washer 2 and the insulating washer 3 are fitted together to be integrated. The annular projections 5 may be claw-shaped ones formed at equal intervals in the circumferential direction.

Here, the glass fiber reinforced plastic forming the insulating washer 3 is difficult to cut due to its inherent property, and if the plate-like glass fiber reinforced plastic is cut out to form the above insulating washer 3, Cracks may occur between each layer of glass fiber reinforced plastic. Therefore, when the insulating washer 3 is formed by, for example, an injection molding method, or when the insulating washer 3 is injection-molded and the metal washer 2 is integrated at the same time, such an electrolytic corrosion preventing washer 1 can be easily formed. it can.

FIG. 3 is a view showing a cross section of a configuration in which two pipe bodies 11 and 12 used for piping are connected by bolts 13 and nuts 14 using the above-mentioned electrolytic corrosion washer 1. Referring to this figure, the pipes 11 and 12 are provided with flanges 15 and 16 respectively having through holes 15a and 16a for inserting bolts at their edges, and the pipes 11 and 12 are provided with respective flanges 15 and 16. The end faces are joined via an insulating gasket 17. The insulating gasket 17 is provided with bolt insertion holes at positions corresponding to the through holes 15a and 16a of the flanges 15 and 16, respectively. Further, the bolt 13 has a screw 13a threaded on the tip side, and the surface of the shaft 13c from the end of the screw 13a to the seat surface of the head 13b is made of, for example, PVdF (polyvinylidene fluoride) or the like. It is coated with a polymer material.

Next, referring to FIG. 3, an example of use of the electrolytic corrosion washer 1 having the above structure will be described. First, the end faces of the tubular bodies 11 and 12 are joined by interposing an insulating gasket 17. Then, the through holes 15a and 16a of the flanges 15 and 16 provided in the pipes 11 and 12 and the holes of the insulating gasket 17 are aligned with each other, while the electrolytic corrosion washer 1 is attached from the metal washer 2 side to the shaft portion 13c of the bolt 13. The bolt 13 in this state is inserted into the through holes 15a and 16a.

When the bolt 13 is inserted almost completely into the through holes 15 a and 16 a, the tip of the bolt 13 projects outward from the flange 16. Therefore, this time, an electrolytic corrosion preventing washer 1 different from the electrolytic corrosion preventing washer 1 is inserted into the protruding bolt 13 from the insulating washer 3 side, and then the nut 14 is screwed into the screw 13a of the bolt 13. Let In this state, the two washer 1 for preventing electrolytic corrosion have the seat surface on the metal washer 2 side located farther from the flanges 15 and 16 and the seat surface on the insulating washer 3 side closer to the flanges 15 and 16. Will be placed. Such work corresponds to the number of through holes 15a and 16a formed in the flanges 15 and 16, for example, if four through holes 15a and 16a are formed at equal intervals in the circumferential direction. The same work as described above is repeated using four bolts 13 and nuts 14 and eight washer 1 for preventing electrolytic corrosion.

As described above, since the metal washer 2 and the insulating washer 3 are integrated in the washer 1 for preventing electrolytic corrosion, the metal washer 2 and the insulating washer 3 can be inserted at the same time at a time, and the assembling Since the time and labor can be reduced by half, workability can be improved. After that, the nut 14 is tightened using a tool such as a wrench. At the time of this tightening, a compressive force acts on the electrolytic corrosion preventing washer 1, but since the insulating washer 3 is made of glass fiber reinforced plastic, the electrolytic corrosion preventing washer 1 is attached to the tightening torque of the nut 14. The strength of the insulating washer 3 is secured, so that even if the nut 14 is strongly tightened, the insulating washer 3 will not crack or break.

In this way, when the nuts 14 are tightened to complete the connection of the pipe bodies 11 and 12, the shaft portion 13c of the bolt 13 and the flanges 15 and 16 are made of the coating material applied to the shaft portion 13c of the bolt 13. It is insulated, and the metal washer 2 and the flanges 15 and 16 of the electrolytic corrosion preventing washer 1 are insulated by the insulating washer 3. Therefore, even if the electrolyte solution flows inside the pipe after the completion of the piping, the electrochemical corrosion does not occur due to the insulation, and therefore the breakage of the bolt 13 and other troubles are surely prevented.

In this embodiment, the washer 1 for preventing electrolytic corrosion is described as having the shape shown in FIGS. 1 and 2, but the present invention is not limited to this example, and the insulating washer may be the metal washer 2 shown in the figure. It may be formed in the same shape and bonded to each other with an adhesive or the like. Alternatively, as shown in the cross section in FIG. 4, the insulating washer 3 has a small diameter to be fitted inside the annular projection 5 of the metal washer 2. It may be composed of a portion 6 and a large diameter portion 7 continuous with the small diameter portion 6 and having the same diameter as the outer diameter of the metal washer 2. The washer 1 for preventing electrolytic corrosion shown in this figure may be formed with the dimensions of each part as shown in FIG. 5, for example, and in particular, the table in this figure shows the numerical values when the nominal diameter of the bolt 13 is M16. An example is shown.

Further, the electrolytic corrosion preventing washer 1 shown in FIGS. 1, 2, and 4 has the same effect as above even if the metal washer 2 and the insulating washer 3 are formed in the opposite shapes. (That is, the washer having the shape indicated by reference numeral 2 in FIGS. 1 and 2 and 4 is an insulating washer, and the washer having the shape indicated by reference numeral 3 is a metal washer). In addition, the metal washer 2 and the insulating washer 3 may be integrated by any method, and the electrolytic corrosion preventing washer 1 may be used for other than connecting the pipes.

[0022]

[Effect of device]

 As is clear from the above description, according to the washer for preventing electrolytic corrosion of the present invention, the following effects can be obtained. According to the first aspect, the washer made of metal and the washer made of the electrical insulator can be assembled at the same time at one time, so that the labor in the assembling work can be omitted and therefore the workability is improved. In addition, it is possible to prevent mistakes such as forgetting to attach either the metal washer or the insulating washer.

According to the second aspect, it is possible to save the labor in the assembling work, and to prevent the mistake of forgetting to attach one of the metal washer and the washer made of the electric insulator. Therefore, workability and productivity can be improved. According to the third aspect, it is possible to save the labor in the assembling work, and it is possible to prevent the mistake of forgetting to attach one of the metal washer and the washer made of the electric insulator. As a result, the efficiency of the assembling work can be realized and the productivity can be improved.

[Brief description of drawings]

FIG. 1 is a front view showing an embodiment of a washer for preventing electrolytic corrosion of the present invention.

FIG. 2 is a sectional view taken along line XX of FIG.

FIG. 3 is a cross-sectional view showing a state where pipes are connected by bolts and nuts using the washer for preventing electrolytic corrosion of the present invention.

FIG. 4 is a cross-sectional view showing another example of a washer for preventing electrolytic corrosion.

5 is a diagram showing an example of various dimensions of the electrolytic corrosion washer shown in FIG.

[Explanation of symbols]

 1 Washer for preventing electrolytic corrosion 2 Metal washer 3 Insulation washer 4 Seat surface (engagement part) 5 Annular protrusion 6 Small diameter part 7 Large diameter part

Claims (3)

[Scope of utility model registration request] 1. A washer for preventing electrolytic corrosion, characterized in that a washer made of metal and a washer made of an electrical insulator attached so as to cover at least one seat surface of the washer are integrated. 2. A washer made of metal and a washer made of an electrical insulator are integrated, and one washer of the washer made of the metal and the washer made of the electrical insulator is one of the other washers. A seat surface portion that covers the seat surface, and an engaging portion that stands up from the seat surface portion and engages with the peripheral surface of the other washer, and the one washer is externally fitted to the other washer. A characteristic washer for preventing electrolytic corrosion. 3. A washer made of metal and a washer made of an electrical insulator are integrated, and one washer of the washer made of the metal and the washer made of the electrical insulator is A seat surface portion that covers the seat surface, and an engaging portion that rises from the seat surface portion and engages with the peripheral surface of the other washer, and the other washer is inside the engaging portion of the one washer. A washer for preventing electrolytic corrosion, comprising a small-diameter portion to be internally fitted and a large-diameter portion continuous with the small-diameter portion and having the same diameter as the outer diameter of the seat surface portion of the one washer.