JP6527366B2 - Washer screw - Google Patents

Description

  The present invention relates to a washer screw in which a washer is incorporated below the neck.

  Conventionally, a bolt shown in Patent Document 1 is known as a screw with a washer. The bolt has a hexagonal head, a step connected to the head, a bolt body continuously connected to the step, and a disc spring (a washer) disposed on the step. And. The shoulder portion of the bolt has a diameter larger than that of the bolt main body and smaller than that of the head, and is configured to be seated on the work surface in a state where the bolt is completely tightened. Further, this stepped portion has a thickness slightly larger than the disc spring, and in the state where the bolt is completely tightened (the stepped portion is seated on the work surface), the disc spring is in the middle of elastic deformation It is supposed to be kept in the state.

Japanese Utility Model Publication No. 45-23058

  In recent years, in a vibration-proof structure for suppressing transmission of mechanical vibration in a mechanical device, or in a seismic isolation structure for reducing earthquake sway in a building, structural components There is a need for a fastening structure that can be operated relatively to a certain extent when it is necessary to keep it properly fixed and to reduce vibrations and shaking. On the other hand, in the above-mentioned conventional bolt, the stepped portion and the disc-shaped spring are brought into contact with the same surface of the object to be fastened, and the bolt is tightened in a predetermined state in which the resilient force of the disc-shaped spring is effective. Therefore, the object to be fastened is kept in a firmly fastened state. Therefore, in the fastening structure using this bolt, problems such as being unable to reduce mechanical vibration, earthquake shaking and the like have occurred.

The present invention is created in view of the above-mentioned subject, and an object of the present invention is to provide a screw with a washer which allows predetermined movement of a thing to be fastened even after fastening. In order to achieve this object, the present invention provides a head provided with a drive capable of engaging a predetermined screw tightening tool, a screw having a screw thread, and a neck provided between the head and the screw. A lower portion and a washer disposed at the lower portion of the neck and elastically deformable according to the screwing of the screw into the fastening, the washer being disposed on the screw side and screwing the threaded into the fastener It is composed of a first washer made of elastically deformable rubber and a second washer made of metal which is disposed on the head side and is polymerized to the first washer, and the diameter of the lower neck portion is a screw portion. Is larger than the diameter of the hole of the screwed-in object and smaller than the attachment hole of the object to be fastened, and its length L is shorter than the thickness t3 plus the thickness of the washer and the object to be fastened, And in the screwed-in state immediately before the washer is deformed Wherein the septum t4 is configured to a length smaller than the thickness t5 of the first washer. As a result, the lower portion of the neck of the screw with a washer can be inserted through the mounting hole of the object to be seated on the object, and the washer can be pressed against the object in a deformed state maintaining elastic force. Therefore, it is possible to fasten the workpiece with an appropriate force by the washer while tightening the washer screw with a predetermined tightening torque. Further, the first washer can be appropriately deformed while being restricted by the second washer, and the second washer can be prevented from coming into contact with the object to be fastened. Moreover, since the washer is as described above, the first washer can be restricted by the second washer to prevent irregular elastic deformation of the first washer.

  According to the present invention, since the object to be fastened can be fastened with an appropriate force by the elastic force of the washer while tightening the washer screw with a predetermined tightening torque as described above, the loosening of the washer screw is prevented. At the same time, it is possible to obtain the effect of enabling the operation of the fastened object when a force exceeding the fastening force of the washer acts on the fastened object. Thereby, there is an advantage such as being able to provide a fastening structure suitable for a vibration resistant structure or a seismic isolation structure. In addition, since the irregular elastic deformation of the first washer made of rubber or the like can be accurately controlled by the second washer made of metal or the like, the elastic force and the frictional force of the first washer acting on the object to be fastened are uniformed. There is also an advantage that it becomes possible to stabilize and securely hold the object to be fastened, and the like. Furthermore, since the length of the lower neck portion is set to a length such that the second washer made of a material having a high elastic modulus such as metal does not come in contact with the object to be fastened, It is possible to prevent damage to the surface and to prevent the object to be rubbed against the second washer to emit an unpleasant sound even when the object to be fastened moves with respect to the washer screw.

It is sectional drawing which shows the state of the middle of screwing of the screw with a washer which concerns on this invention. It is a front view of a screw with a washer concerning the present invention. It is a top view of a screw with a washer concerning the present invention. It is sectional drawing which shows the fastening state of the screw with a washer which concerns on this invention. It is a perspective view for explanation of a conclusion state of a screw with a washer concerning the present invention.

Hereinafter, an embodiment of the present invention will be described based on the drawings.
In FIGS. 1 to 5, reference numeral 1 denotes a screw with a washer, and a flanged hexagonal head 2, a cylindrical neck lower portion 3 continuous with the head 2, and a screw portion 4 continuous with the neck lower 3 And a washer 5 assembled to the lower neck portion 3. The head portion 2 of the screw with washer 1 is provided with a drive portion 7a which can be engaged with a predetermined screw tightening tool, and the screw portion 4 is fitted in a pilot hole 6a provided in a fastening 6 An external thread 4a that can be screwed in while forming the thread is formed. Thus, the main screw 1 is configured as a self-tapping screw that is fastened while forming a female screw on a mating member. The lower neck portion 3 of the screw with washer 1 has a diameter φ D smaller than the diameter of the head 2 and larger than the diameter φ d1 of the lower hole 6 a of the fastening 6 into which the screw 4 is screwed. The mounting hole 7a is smaller than the mounting hole 7a. Further, the length L of the neck lower portion 3 is shorter than a thickness t3 obtained by adding the thickness t2 of the object 7 to the thickness t1 of the washer 5 and the screwed state immediately before the washer 5 is deformed (FIG. 1) In the state shown), an interval t4 (hereinafter, simply referred to as an interval t4) between the seating surface 3a of the lower neck portion 3 and the seating surface 6b of the fastening object 6 is set to a length smaller than the thickness t1 of the washer 5 There is.

  The washer 5 has a circular umbrella-like shape, and is disposed on the side of the screw 4 and is capable of elastically deforming as the screw 4 is screwed into the fastener 6, and the first washer 5a. The second washer 5b disposed closer to the head 2 is integrated with one another by polymerizing and bonding. In the washer 5, the first washer 5a is made of rubber, the second washer 5b is made of metal material (stainless steel for spring), and the second washer 5b has a higher elastic modulus than the first washer 5a. It is configured. Further, the washer 5 is formed such that the center hole of the first washer 5a made of rubber has a diameter slightly smaller than the diameter of the neck lower portion 3, and the washer 5 is pushed by the neck lower portion 3 there. It is held so as not to fall out of the

  The main screw 1 is intended to deform the first washer 5a made of rubber in preference to the second washer 5b made of metal and to fasten the to-be-fastened object 7 by the elastic force and the frictional force of the first washer 5a. It is. For this reason, the length L of the lower neck portion 3 described above is set to a length such that the distance t4 is smaller than the thickness t5 in the vertical direction of the outer edge of the first washer 5a. As a result, the lower neck portion 3 can be seated on the fastening object 6 before the second washer 5b abuts on the workpiece 7, and the first washer 5a is crushed by the second washer 5b and is deformed extremely To prevent the elastic force and the frictional force of the first washer 5a from acting effectively (see FIG. 4).

  In the screw 1 with a washer, the lower neck portion 3 can pass through the mounting hole 7 a of the object 7 when the object 7 is fastened to the object 6, and enters the lower hole 6 a of the object 6. Can not. Therefore, when the screw portion 4 is screwed into the pilot hole 6a, the seat surface 3a of the neck lower portion 3 is seated on the seating surface 6b of the fastening object 6 (surface of the fastening object 6 flush with the opening end face of the pilot hole 6a) As a result, the tightening torque is increased to a predetermined value and the washer screw 1 is tightened. At this time, since the length L of the lower neck portion 3 is configured as described above, the washer 5 maintains an appropriate elastic force between the bearing surface 2 b of the head 2 and the object 7 to be fastened. It will be in an elastic deformation state. In the present embodiment, since the washer 5 is configured as a composite of rubber and metal material as described above, the first washer 5a is deformed preferentially in a state where the lower neck portion 3 is seated, and the second The washer 5b functions to restrict the range of deformation of the first washer 5a with almost no elastic deformation. As a result, irregular deformation of the first washer 5a can be prevented, and dispersion and destruction of the elastic force and the frictional force caused thereby can be prevented. Therefore, the first washer 5a can be pressed into good contact with the object to be fastened 7, and the elastic force and the frictional force of the first washer 5a can be uniformly applied, and the object to be fastened 7 can be stably fixed to the object 6. And, it will be possible to securely conclude. In general, the use of an elastically deformable washer such as rubber makes the screw easy to loosen, but in the present invention, the lower neck portion 3 of the screw 1 with a washer is seated around the opening end of the pilot hole 6a and tightened with a predetermined tightening torque. Therefore, it is possible to prevent the loosening of the washer screw 1 itself.

  The object to be fastened 7 is fastened to the fastener 6 in the fastening form of the washer screw 1 as described above, so by applying a predetermined force (a force exceeding the frictional force of the first washer 5a), FIG. As indicated by the arrows in FIG. 5, when the mounting hole 7a of the object 7 is a long hole, it can be moved in the longitudinal direction. For this reason, when this screw with washer 1 is used for fastening the seismic isolation structure member of a building etc., the seismic isolation structural member is always kept in a state of being fastened with a prescribed fastening force, and when an earthquake occurs It is possible to allow the operation of the seismic isolation structure member accompanying with. Further, since the length of the neck lower portion 3 is set such that the second metal washer 5b does not abut on the object 7, the second washer 5b is operated when the object 7 is operated as described above. While being able to prevent that the surface of the to-be-fastened object 7 is damaged, it is also possible to prevent it being rubbed with the 2nd washer 5b, and producing unpleasant noises, such as a squeaking noise.

  In the above embodiment of the present invention, an example in which the washer screw 1 is a self-tapping screw and the pilot hole 6a is provided in the fastening object 6 to screw in the washer screw 1 has been introduced. A female screw may be formed in advance, and a screw with a washer may be screwed into this. In such a configuration, the diameter of the lower portion of the neck of the washer screw may be set larger than the inner diameter of the female thread of the object to be fastened. In addition, as the washer, various washers that can be elastically deformed according to the screwing of the screw portion, such as a washer made only of rubber, a spring washer, a disc spring washer, etc., can be applied.

Reference Signs List 1 washer screw 2 head 2a drive 2b seat 3 neck lower 3a seat 4 thread 4a screw 5 washer 5 washer 1 washer 5 b washer 2 fastening 6 a pilot 6 a seating 7 seating 7 a hole

Claims (1)

A head provided with a drive portion engageable with a predetermined screw tightening tool, a screw portion having a screw thread, a neck lower portion provided between the head and the screw portion, and a screw disposed at the neck lower portion Consisting of a washer that can be elastically deformed with screwing of the parts to the fasteners,
The washer is disposed on the screw portion side, and a first washer made of rubber that can be elastically deformed with screwing of the screw portion into a fastening, and a metal disposed on the head side and polymerized to the first washer The second washer and consists of
The lower neck is
The diameter D is larger than the diameter of the hole of the fastener into which the screw is screwed and smaller than the mounting hole of the fastener
Further, the length L is shorter than a thickness t3 obtained by adding the respective thicknesses of the washer and the object, and the distance t4 between the opposing neck lower seating surface and the fastening object seating surface in the screwed state immediately before the washer deforms. A screw having a length smaller than the thickness t5 of the first washer .

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