JP2010276124A - Tightening tool and method for manufacturing the same - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To provide a tightening tool capable of obtaining an axial force required when tightening with a predetermined tightening torque in tightening a tightened body formed of thermal spraying coatings for rust prevention. <P>SOLUTION: In the tightening tool which is employed for tightening of the tightened body 100 formed of the thermal spraying coatings 101b, 102b, 103b for rust prevention, it includes a bolt 1 formed with the thermal spraying coating 10 for rust prevention on the whole surface containing a head 1a and a thread 1c, a nut 2 which is tightened in the thread 1c of the bolt 1 by interposing the tightened body 100 and is formed with the thermal spraying coating 20 for rust prevention on the whole surface excepting the thread 1c and contact surface (seat surface 2b) of tightened body 100 side, and washers 3, 4 which are washers disposed between the head 1a of the bolt 1 or the nut 2 and the tightened body 100 and are formed with thermal spraying coatings 30, 40 for rust prevention on the whole surface excepting contact surfaces 3a, 4a of the tightened body 100 side. <P>COPYRIGHT: (C)2011,JPO&amp;INPIT

Description

  The present invention is, for example, a spray coating of zinc / aluminum and an alloy thereof applied for the purpose of preventing corrosion of steel as defined in JIS H 8300: 2005 “Spraying of zinc / aluminum and alloys thereof” which is a Japanese industrial standard. The present invention relates to a fastener used for fastening a body to be fastened on which a thermal spray coating for rust prevention such as aluminum, zinc aluminum alloy and aluminum magnesium alloy is applied.

  As a countermeasure against corrosion of a steel structure such as a steel girder of a road bridge, a high corrosion resistance film is formed by spraying a high corrosion resistance alloy on the surface of the steel structure in a factory. And, this type of steel structure requires on-site connection because of its structure, and is often connected on the site using high strength bolts (HTB) and nuts using an attachment plate. However, the high-strength bolts and nuts themselves are not formed with a high corrosion-resistant coating like the steel structure body, so the life of the high-strength bolts and nuts is shorter than that of the steel structure body. It is necessary to perform maintenance according to the service life of the nut.

  Therefore, it is desired to form a high corrosion resistance film on the high-strength bolts and nuts as well as the surface of the steel structure. For example, Patent Literature 1 discloses a bolt in which a thermal spray layer having a thickness of 10 to 150 μm made of a metal or an alloy such as molybdenum, chromium, tungsten, or the like is provided on a screw portion of the bolt main body or on the whole. Patent Document 2 discloses a bolt in which hard particles having a particle size of 10 μm or less are attached to a pressure-receiving screw surface by a high-speed flame spraying method.

JP-A-3-41207 JP 2004-176901 A

  And in order to use high strength bolts and nuts with the same service life as the steel structure body on which the high corrosion resistance film is formed, not only the threaded portion of the high strength bolt as described in Patent Documents 1 and 2, It is considered necessary to form a high corrosion resistance sprayed coating on the entire high strength bolt and nut. However, when a steel structure is tightened using high-strength bolts and nuts that have been formed by spraying a high corrosion-resistant coating, the required axial force may not be obtained even when tightening with a predetermined tightening torque. I understood.

  The problem to be solved by the present invention is to provide a fastener capable of obtaining an axial force required when tightened with a predetermined tightening torque in fastening of a fastened body on which a thermal spray coating for rust prevention is formed. The purpose is to do.

  As a result of intensive research on tightening the object to be fastened with the rust-preventing thermal spray coating with the bolts and nuts with the rust-preventive thermal spraying film formed, When the thermal spray coating surface and the bolt and nut anti-corrosion coating surfaces are tightened together, soft sliding coatings for anti-corrosion are integrated with each other due to seizure on the sliding surface, allowing further tightening. It was found that it was lost, and the present invention was made.

  The fastener of the present invention is a fastener used for fastening a fastened body on which a rust-proof spray coating is formed, and a bolt having a rust-proof spray coating formed on the entire surface including the head and the screw portion. And a nut that is fastened to the threaded portion of the bolt across the body to be fastened, and a nut that has an anti-rust spray coating formed on the entire surface excluding the inner threaded portion and the contact surface on the body to be fastened. is there.

  Further, the fastener of the present invention is a fastener used together with a bolt having a rust-proof spray coating formed on the entire surface including a head and a screw portion for fastening a fastened body on which a rust-proof spray coating is formed. A fastener including a nut that is fastened to a threaded portion of a bolt across a body to be fastened and has a rust-proof spray coating formed on the entire surface except the inner threaded portion and the contact surface on the body to be fastened. It is.

  In these fasteners of the present invention, since the thermal spray coating for rust prevention is not formed on the inner threaded portion of the nut and the contact surface on the fastened body side, the sliding between the nut and the fastened body during tightening of the nut In the sliding surfaces of the surface and the inner threaded portion of the nut and the threaded portion of the bolt, the rust-preventing thermal spray coating exists only on one surface. Therefore, when the nut is tightened, the spray coating for rust prevention is not integrated on the sliding surface as described above, and the nut can be tightened to the end with a predetermined tightening torque.

  In addition, after tightening with the fastener of the present invention, the rust-preventing thermal spray coating on the opposite side is in close contact with the inner screw portion of the nut on which the rust-preventing thermal spray coating is not formed and the contact surface on the fastened body side. Since it is integrated, it is protected by this thermal spray coating for rust prevention.

  Further, the fastener of the present invention is a fastener used together with a bolt having a rust-proof spray coating formed on the entire surface including a head and a screw portion for fastening a fastened body on which a rust-proof spray coating is formed. A nut that is fastened to the threaded portion of the bolt across the body to be fastened, and between the inner screw portion and the nut on which the rust-proof spray coating is formed on the entire surface excluding the contact surface on the body to be fastened. It is a washer to be disposed, and is a fastener including a washer in which a thermal spray coating for rust prevention is formed on the entire surface excluding the contact surface on the fastened body side.

  In the fastener of the present invention, the washer disposed between the nut and the body to be fastened has a rust-proof sprayed coating formed on the entire surface except the contact surface on the body to be fastened, and the washer to be fastened Since the thermal spray coating for rust prevention is not formed on the contact surface, the thermal spray coating for rust exists only on one surface of the sliding surface between the washer and the body to be fastened when the nut is tightened. Also, since the sprayed coating for rust prevention is not formed on the inner threaded part of the nut and the contact surface on the fastened body side, the sliding surface of the nut and washer when tightening the nut and the inner threaded part of the nut and the bolt In the sliding with the threaded portion, the thermal spray coating for rust prevention exists only on one surface. Therefore, when the nut is tightened, the spray coating for rust prevention is not integrated on the sliding surface as described above, and the nut can be tightened to the end with a predetermined tightening torque.

  Further, after tightening with the fastener of the present invention, the contact surface on the fastened body side where the washer antirust spray coating is not formed, and the inner screw portion where the nut antirust spray coating is not formed and the fastened body side The contact surface of the rust preventive spray coating on the opposite side is in close contact and integrated with each other, so that the rust preventive spray coating is protected.

  Here, it is preferable that the rust-preventing spray coating of the nut is formed by an arc spraying method, and the rust-preventing spraying coating of the bolt is formed by a gas spraying method or a plasma spraying method. The rust-proof spray coating formed by arc spraying has a rougher surface roughness and higher adhesion than rust-proof spray coatings formed by gas spraying or plasma spraying. By applying to a nut that is rotated by the above, it is possible to prevent the thermal spray coating for rust prevention from peeling off. On the other hand, since the surface roughness of the rust-preventing spray coating formed by gas spraying or plasma spraying is fine, the surface of the rust-preventing spraying coating formed on the screw thread of the bolt when applied to the bolt is smooth. It becomes easy to tighten the nut.

(1) A nut that is fastened to a threaded portion of a bolt with a body to be fastened interposed therebetween, and includes a nut having a rust-proof spray coating formed on the entire surface excluding the inner threaded portion and the contact surface on the body to be fastened. Therefore, when the nut is tightened, the thermal spray coating for rust prevention is not integrated on the sliding surface, and it can be tightened to the end with the predetermined tightening torque, which is required when tightening with the predetermined tightening torque. It is possible to obtain a certain axial force.

(2) According to the fastener including the washer having the rust-proof spray coating formed on the entire surface except the contact surface on the fastened body side, the rust-proof spray coating is integrated on the sliding surface when the nut is tightened. Since it can be tightened to the end with a predetermined tightening torque, the axial force required when tightening with the predetermined tightening torque can be obtained.

(3) The antirust spray coating of the nut is formed by the arc spraying method, and the antirust spray coating of the bolt is formed by the gas spraying method or the plasma spraying method. As a result, it is possible to prevent peeling of the rust-preventing sprayed coating when the nut is rotated, and the surface of the rust-preventing sprayed coating formed on the threaded portion of the bolt becomes smooth and the nut can be easily tightened.

It is a side view which shows the fastener in embodiment of this invention. It is a side view which shows the state which decomposed | disassembled the fastener of FIG. It is explanatory drawing which shows the spray coating surface for rust prevention of the coupling tool of FIG.

  1 is a side view showing a fastener according to an embodiment of the present invention, FIG. 2 is a side view showing a state where the fastener of FIG. 1 is disassembled, and FIG. 3 is a thermal spray for rust prevention by disassembling the joint of FIG. It is explanatory drawing which shows a film formation surface.

  As shown in FIGS. 1 and 2, a fastener in an embodiment of the present invention is for connecting a steel structure 101 as a body to be fastened 100 by means of attachment plates 102 and 103, and has a steel structure. The bolt 101, the nut 2, and the washers 3 and 4 are used to fasten the object 101 and the attachment plates 102 and 103 together. As shown in FIG. 3, the surface of the steel structure 101 and the attachment plates 102 and 103 and the bolt holes 101a, 102a and 103a for inserting the bolts 1 are used for rust prevention of an Al-Mg alloy. Thermal spray coatings 101b, 102b, and 103b are formed on the entire surface.

  The bolt 1 is a hexagon bolt inserted into the bolt holes 101a, 102a, 103a of the steel structure 101 and the attachment plates 102, 103. As shown in FIG. 3, the bolt 1 has an Al—Mg alloy rust-preventing sprayed coating 10 formed on the entire surface including the head portion 1a, the body portion 1b and the screw portion 1c. The rust-proof spray coating 10 of the bolt 1 is formed by a gas spray method or a plasma spray method.

  The nut 2 is a seated hexagon nut that is fastened to the threaded portion 1c of the bolt 1 with the steel structure 101 and the attachment plates 102 and 103 interposed therebetween. The nut 2 has a seat surface 2b having a smaller diameter than the hexagonal two-surface width. As shown in FIG. 3, the nut 2 has a rust-preventing thermal spray coating 20 made of an Al-Mg alloy formed on the entire surface excluding the inner screw portion 2a and the seating surface 2b which is a contact surface on the steel structure 101 side. . The rust-proof spray coating 20 of the nut 2 is formed by an arc spraying method.

  The washer 3 is disposed between the head 1 a of the bolt 1 and the fastened body 100, and the washer 4 is disposed between the nut 2 and the fastened body 100. As shown in FIG. 3, the washer 3 has a rust-proof thermal spray coating 30 of an Al—Mg alloy formed on the entire surface including the contact surface 3 a on the fastened body 100 side and the inner surface of the bolt hole 3 b. The washer 4 includes an inner surface of the bolt hole 4b, and a rust-preventing sprayed coating 40 made of an Al—Mg alloy is formed on the entire surface excluding the contact surface 4a on the fastened body 100 side. The anti-rust spray coatings 30 and 40 of the washers 3 and 4 are formed by arc spraying.

  In the fastener having the above configuration, the thermal spray coating 20 for rust prevention is not formed on the inner threaded portion 2a of the nut 2 and the seat surface 2b which is the contact surface on the fastened body 100 side. On the sliding surface between the nut 2 and the washer 4 and the sliding surface between the inner threaded portion 2a of the nut 2 and the threaded portion 1c of the bolt 1, the rust-preventing sprayed coatings 10, 40 are present only on one surface. Therefore, when the nut 2 is tightened, the rust-proof spray coating 20 of the nut 2 and the rust-proof spray coatings 10 and 40 of the bolt 1 and the washer 4 are not integrated with each other on the sliding surface.

  Further, in the fastener in the present embodiment, the washer 4 disposed between the nut 2 and the body to be fastened 100 is a covered surface that serves as a sliding surface between the washer 4 and the body to be fastened 100 when the nut 2 is tightened. The rust preventive spray coating 40 is not formed on the contact surface 4a on the fastening body 100 side, and the rust preventive spray coating 103b exists only on one surface of the sliding surface. For this reason, when the nut 2 is tightened, the rust-proof sprayed coating 40 of the washer 4 and the rust-proof sprayed coating 103 b of the fastened body 100 are not integrated with each other on the sliding surface.

  That is, in this fastener, the rust-proof spray coating 20 on the nut 2 and the rust-proof spray coatings 10 and 40 on the bolt 1 and the washer 4 are integrated on the sliding surface when the nut 2 is tightened. In addition, since the spray coating 40 for rust prevention of the washer 4 and the spray coating 103b for rust prevention of the fastened body 100 are not integrated, it can be tightened to the end with a predetermined tightening torque. Therefore, with this fastener, it is possible to obtain the axial force required when tightening with a predetermined tightening torque.

  In addition, in the fastener in this embodiment, the washer 3 arrange | positioned between the head 1a of the volt | bolt 1 and the to-be-fastened body 100 has the thermal spray coating 30 for rust prevention also on the contact surface 3a by the to-be-fastened body 100 side. Although it is formed, since the head 1a of the bolt 1 is fixed and the nut 2 side is rotated and tightened when the normal fastened body 100 is tightened, the contact surface 3a does not become a sliding surface. ,No problem. In addition, the washer 3 can also be set as the structure which forms the thermal spray coating 30 for rust prevention except the contact surface 3a similarly to the washer 4. FIG.

  In addition, after the fastening with this fastener, all the surfaces exposed on the surface are protected by the rust-proof sprayed coatings 10, 20, 30, 40, 101b, 102b, 103b. Moreover, since the thermal spray coating 40 for rust prevention of each facing surface is closely_contact | adhered and integrated with the internal thread part 2a and the seat surface 2b in which the rust preventive spray coating 20 of the nut 2 is not formed, this rust prevention The thermal spray coating 40 is protected. Further, since the spray coating 103b for rust prevention on the facing side is in close contact with and integrated with the contact surface 4a on the fastened body 100 side where the spray coating 40 for rust prevention of the washer 4 is not formed, these rust prevention It is protected by the thermal spray coating 103b.

  Moreover, in the fastener in this embodiment, the rust preventive spray coating 20 is formed by arc spraying method in which a coating having a high surface roughness and high adhesion is formed on the nut 2. In this case, since the rust-preventing sprayed coating 10 is formed by a gas spraying method or a plasma spraying method in which a coating with a fine surface roughness is formed, even if the nut 2 is rotated by an impact wrench or the like, the hexagon of the nut 2 Peeling of the rust-preventing thermal spray coating 20 at the corners is prevented. On the other hand, since the surface of the rust-proof spray coating 10 formed on the screw portion 1c of the bolt 1 by gas spraying or plasma spraying is smooth, the nut 2 can be easily tightened.

  In addition, although the fastener in this embodiment is comprised with the volt | bolt 1, the nut 2, and the washers 3 and 4, it is also possible to abbreviate | omit any one or both of the washers 3 and 4. Similarly in this case, the sliding surface between the nut 2 and the body to be fastened 100 and the sliding surface between the inner threaded portion 2a of the nut 2 and the threaded portion 1c of the bolt 1 when tightening the nut 2 are used for rust prevention. The thermal spray coatings 10, 40 are present only on one side. Therefore, when the nut 2 is tightened, the rust-proof sprayed coating 20 of the nut 2 and the rust-proof sprayed coating 10 of the bolt 1 are not integrated with each other on the sliding surface. It can be tightened to the end with torque, and the axial force required when tightening with a predetermined tightening torque can be obtained.

  Moreover, although the fastener in this embodiment forms the thermal spray coating 10, 20, 30, 40 for rust prevention with the same Al-Mg alloy as the body 100 to be fastened, the spray coating for rust prevention of the body 100 to be fastened. Depending on the material, it may be formed of zinc, aluminum or an alloy thereof.

  The fastener of the present invention is useful as a fastener used for fastening a fastened body on which a thermal spray coating for rust prevention is formed.

DESCRIPTION OF SYMBOLS 1 Bolt 1a Head 1b Body 1c Thread part 2 Nut 2a Inner thread part 2b Seat surface 3, 4 Washer 3a, 4a Contact surface 3b, 4b Bolt hole 10, 20, 30, 40 Anticorrosion sprayed coating 100 Fastened body 101 Steel structure 102, 103 Joint plate 101a, 102a, 103a Bolt hole 101b, 102b, 103b Thermal spray coating for rust prevention

Claims (8)

A fastener used for fastening a fastened body on which a thermal spray coating for rust prevention is formed,
A bolt having a thermal spray coating for rust prevention formed on the entire surface including the head and screw part;
A nut that is fastened to a screw portion of the bolt with the clamped body interposed therebetween, and includes a nut having a rust-proof spray coating formed on the entire surface except the inner screw portion and the contact surface on the clamped body side. . A fastener that is used together with a bolt having a rust-proof spray coating formed on the entire surface including the head and the screw portion for fastening a fastened body on which a rust-proof spray coating is formed,
A fastener including a nut that is fastened to a screw portion of the bolt with the fastened body interposed therebetween, and a rust-proof sprayed coating is formed on the entire surface excluding an inner screw portion and a contact surface on the fastened body side.   The fastener according to claim 1 or 2, comprising a washer disposed between the nut and the body to be fastened, wherein the washer has a rust-proof spray coating formed on the entire surface except the contact surface on the fastened body side. . A fastener that is used together with a bolt having a rust-proof spray coating formed on the entire surface including the head and the screw portion for fastening a fastened body on which a rust-proof spray coating is formed,
It is a nut that is fastened to the threaded portion of the bolt across the fastened body, and is disposed between an inner screw portion and a nut having a rust-proof spray coating formed on the entire surface except the contact surface on the fastened body side. A fastener including a washer having a rust-proof sprayed coating formed on the entire surface excluding the contact surface on the fastened body side. The rust-preventing thermal spray coating of the nut is formed by arc spraying,
The fastener according to any one of claims 1 to 4, wherein the rust-proof spray coating of the bolt is formed by a gas spray method or a plasma spray method. A method of manufacturing a fastener for use with a bolt having a rust-proof spray coating formed on the entire surface including a head and a screw portion for fastening a fastened body formed with a rust-proof spray coating,
A fastener manufacturing method characterized by forming a spray coating for rust prevention on the entire surface excluding an inner screw portion of a nut that is fastened to a screw portion of the bolt across the fastened body and a contact surface on the fastened body side. Method. A fastener that is used together with a bolt having a rust-proof spray coating formed on the entire surface including the head and the screw portion for fastening a fastened body on which a rust-proof spray coating is formed,
It is a nut that is fastened to the threaded portion of the bolt across the fastened body, and is disposed between an inner screw portion and a nut having a rust-proof spray coating formed on the entire surface except the contact surface on the fastened body side. A method of manufacturing a fastener, comprising: forming a rust-proof sprayed coating on the entire surface of the washer that is to be bonded except for the contact surface on the fastened body side. The nut rust-proof spray coating is formed by arc spraying,
The method for manufacturing a fastener according to claim 6 or 7, wherein the rust-proof thermal spray coating of the bolt is formed by a gas thermal spraying method or a plasma thermal spraying method.

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