JP2010190859A - Fastening force management method and management device of tapered screw - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To provide a fastening force management method and a device of a tapered screw capable of managing a fastening force simply and highly accurately. <P>SOLUTION: In this fastening force management method of the tapered screw 1 for managing the fastening force between a tapered female screw part 32 formed on the inner circumferential surface of a hollow cylindrical fastening part 3a and a tapered male screw part 21 or a parallel male screw part engaged with the tapered female screw part 32, an elastic deformation amount which is an enlarged amount of an outer diameter of the fastening part 3a is detected, and the detected elastic deformation amount is converted into the fastening force based on a proportional relation between the elastic deformation amount of the fastening part outer diameter and the fastening force, to thereby manage the fastening force between the tapered female screw 32 and the tapered male screw 21 or the parallel male screw. <P>COPYRIGHT: (C)2010,JPO&INPIT

Description

  The present invention relates to a taper screw fastening force management method and a management device that manage the fastening force of a taper screw used in a pipe joint or the like.

The taper screw is fastened by screwing a taper male screw or parallel male screw into the taper female screw and pressing the taper inner surface of the female screw outward with the outer peripheral surface of the male screw. Widely used for joints.
An example of a pipe joint member conventionally used is shown in FIG.
FIG. 4A shows a T-shaped pipe joint member 40, and three end portions of the pipe joint member 40 formed in a T-shape are provided with tapered female thread portions 41 on the inner peripheral surface thereof. . A pipe extending in three directions can be fastened by fitting a taper male thread part or a parallel male thread part of the pipe member to the taper female thread part 41 and screwing them together. FIG. 4B shows a straight type pipe joint member 45, and a taper male thread part 46 is provided on the outer peripheral surface of the end part of the pipe joint member. The tapered male threaded portion 46 is fitted into the tapered female threaded portion of the piping member, and the head 47 of the piping joint member 45 is rotated with a wrench so that the tapered male threaded portion 46 is screwed into the tapered female threaded portion and fastened. It has become so.

  Conventionally, the taper screw is often manually tightened. As shown in FIG. 5A, when fastening the piping member 50 having the tapered female screw portion 51 and the piping member 52 having the tapered male screw portion 54, the piping member 50 is fixed by a fixing device 60, By fitting the male threaded portion 54 of the piping member 52 to the female threaded portion 51 of the piping member 50 and rotating the head 53 of the piping member 52 with the wrench 61, the threaded portion 54 is screwed into the female threaded portion 51. The male screw portion 54 is fastened by pressing the female screw portion 51 outward.

However, in such a fastening method, there is a large variation in fastening force, and the joint member may be damaged due to overtightening, or the fastening state may be loosened due to insufficient fastening, and fluid inside the pipe may leak.
As a means for adjusting the fastening force, a torque wrench that can be adjusted to a preset torque is used as disclosed in Patent Document 1 (Japanese Patent Laid-Open No. 2000-280184). As another method, when a male screw and a female screw are screwed together, there is a method in which a marking for defining an angle is provided and a target fastening force is obtained by tightening along the marking.

JP 2000-280184 A

However, most of the tightening torque applied to the male screw is consumed by the contact friction between the male screw and the female screw. Therefore, even if the tightening torque is adjusted, the axial force of the taper screw does not always reach the target value. Accordingly, the fastening force varies, and as described above, it has been impossible to reliably avoid damage to the joint member due to overtightening or leakage of internal fluid due to insufficient fastening.
In the method of marking the taper screw with the prescribed angle, there are fastening members that cannot be marked, and therefore, the method is not applicable to all taper screws, and there is a problem that work efficiency is lowered.
Accordingly, an object of the present invention is to provide a fastening force management method and apparatus for a taper screw that can easily and accurately manage a fastening force in view of the above-described problems of the prior art.

Therefore, in order to solve such a problem, the present invention provides a tapered female screw portion formed on the inner peripheral surface of the hollow cylindrical fastening portion and a tapered male screw portion or a parallel male screw portion screwed into the tapered screw portion. In the fastening force management method of the taper screw that manages the fastening force with the threaded portion,
The amount of elastic deformation in which the outer diameter of the fastening portion is increased is detected, and the detected amount of elastic deformation is converted into a fastening force based on the proportional relationship between the amount of elastic deformation of the fastening portion outer diameter and the fastening force, and the taper is performed. The fastening force between the threaded portion and the tapered male threaded portion or the parallel male threaded portion is managed.

  According to the present invention, the internal thread portion is expanded by screwing the external thread portion, the elastic deformation amount of the fastening portion elastically deformed is detected, and the detection is performed based on the proportional relationship between the elastic deformation amount and the fastening force. By converting the fastening force from the amount of elastic deformation and managing the fastening force of the female screw portion and the male screw portion, the fastening force can be managed easily and with high accuracy. Therefore, by using this management method, it is possible to reliably avoid damage to the fastening member due to excessive tightening of the taper screw and leakage of internal fluid due to insufficient tightening.

Furthermore, the elastic deformation amount of the outer diameter of the fastening portion is detected by a laser displacement meter.
In this way, by using the laser displacement meter for detecting the elastic deformation amount of the fastening portion, it is possible to detect without contact, so that the elastic deformation amount can be detected with high accuracy without being affected by the vibration of the taper screw.

Further, a taper screw that manages a fastening force between a taper female screw portion formed on the inner peripheral surface of the hollow cylindrical fastening portion and a taper male screw portion or a parallel male screw portion screwed to the taper screw portion. In the fastening force management device,
A detecting means for detecting the amount of elastic deformation in which the outer diameter of the fastening portion is expanded; and a control device in which the proportional relationship between the amount of elastic deformation of the fastening portion outer diameter and the fastening force is stored.
The control device converts the amount of elastic deformation detected by the detecting means into a fastening force based on the proportional relationship between the amount of elastic deformation of the fastening portion outer diameter and the fastening force, and outputs the result.

Furthermore, the detection means is a laser displacement meter that detects an elastic deformation amount of an outer diameter of the fastening portion.
Furthermore, the taper screw is a taper screw for piping provided in a pipe joint.

As described above, according to the present invention, the amount of elastic deformation in which the fastening portion has expanded is detected, the fastening force is converted from the detected amount of elastic deformation based on the proportional relationship between the amount of elastic deformation and the fastening force, and the female screw By managing the fastening force between the part and the external thread part, it is possible to manage the fastening force easily and with high accuracy.
In addition, by using a laser displacement meter to detect the elastic deformation amount of the fastening portion, non-contact detection is possible, so that the elastic deformation amount can be detected with high accuracy without being affected by the taper screw sway.

It is a figure explaining the fastening force management method of the taper screw which concerns on the Example of this invention. It is a figure explaining the fastening force management method of the taper screw which concerns on the other Example of this invention. It is a graph which shows typically the relation between the amount of elastic deformation, and fastening force. It is a figure which shows the conventional piping coupling, (a) is a side view of a T-shaped piping coupling member, (b) is a side view of a straight type piping coupling member. It is a figure explaining the fastening method of the conventional taper screw, (a) is a side view, (b) is an A arrow view of (a).

  Hereinafter, exemplary embodiments of the present invention will be described in detail with reference to the drawings. However, the dimensions, materials, shapes, relative arrangements, and the like of the components described in this embodiment are not intended to limit the scope of the present invention unless otherwise specified, but are merely illustrative examples. Not too much.

In the present embodiment, the fastening force between the tapered female thread portion formed on the inner peripheral surface of the hollow cylindrical fastening portion and the tapered male thread portion or parallel male thread portion screwed into the tapered thread portion is managed. A method and an apparatus for detecting an elastic deformation amount in which an outer diameter of a fastening portion is expanded, and using the detected elastic deformation amount as a fastening force based on a proportional relationship between the elastic deformation amount of the fastening portion outer diameter and a fastening force. It is the structure which manages the fastening force of the taper female screw and the taper male screw or the parallel male screw in terms of conversion.
This embodiment is preferably used for a pipe taper screw provided in a pipe joint, and is used for various pipes through which fluid flows, such as hydraulic pipes, water pipes, air pipes, and the like.

With reference to FIG. 1, the structure of the fastening force management apparatus of the taper screw which concerns on a present Example is demonstrated.
As shown in FIG. 1, tapered female thread portions 31 and 32 are provided on the inner surface of the end of the hollow cylindrical pipe member 3. The end portion of the piping member 2 provided with the one side taper female thread portion 32 is referred to as a fastening portion 3a. The piping member 3 is fixed by a fixing member 10. When the piping member 3 is fixed, the fastening portion 3 a provided with the tapered female screw portion 32 is disposed so as to protrude from the fixing member 10.
A tapered male screw portion 21 is provided on the outer peripheral surface of the end portion of the other piping member 2. The taper male screw portion 21 provided in the piping member 2 may be a parallel male screw portion. Further, the piping member 2 is provided with a head portion 22 at a position separated from the tapered male screw portion 21 on the base side from the tapered male screw portion 21.
The taper screw 1 includes the taper female screw portion 32 and the taper male screw portion 21.

Further, in the present embodiment, a detecting means for detecting the elastic deformation amount of the outer diameter of the fastening portion 3a provided with the tapered female screw portion 32 is provided. The detection means may be either a contact type or a non-contact type, but preferably uses a non-contact type laser displacement meter 5 as shown in FIG. The laser displacement meter 5 is a well-known device including sensors 6 and 7 having a light projecting unit and a light receiving unit, and a control device 8 that calculates a displacement amount based on a signal from the sensor. Is irradiated with laser light, and the light diffusely reflected from the measurement object is imaged on the photoelectric conversion element through the light receiving portion, and the position of the measurement object is calculated by the triangulation method to obtain the displacement amount. .
As another detection means, an image detection means may be used as shown in FIG. This includes an imaging device 11 that images the fastening portion 3a and a control device 12 to which the captured image 11 is input, and the control device 12 performs image processing on time-series image data captured by the imaging device 11. Then, the amount of elastic deformation of the fastening portion 3a is obtained.

Next, a method for managing the fastening force of the taper screw according to the present embodiment will be described.
First, the piping member 3 is fixed by the fixing member 10 so that the fastening portion 3a provided with the tapered female screw portion 32 protrudes. And the taper male thread part 21 of the piping member 2 is fitted to the taper female thread part 32, the head part 22 of the piping member 2 is rotated in the direction of the arrow in the drawing by a wrench (not shown), and the taper male thread part 21 is moved. The taper female thread portion 32 is screwed. Thereby, the outer peripheral surface of the taper male screw portion 21 presses the inner surface of the taper female screw portion 32 to the outside, and the fastening portion 3a is elastically deformed to expand its diameter. The outer peripheral surface of the enlarged fastening portion 3a 'is in a state indicated by a broken line in the drawing, and is elastically deformed from the outer diameter D of the fastening portion 3a before screwing to the outer diameter D' after screwing. The elastic deformation amount of the fastening portion 3a ′ is (D′−D).

The amount of elastic deformation (D′−D) is detected by the laser displacement meter 5, and the fastening force is calculated from the detected amount of elastic deformation based on the proportional relationship between the amount of elastic deformation and the fastening force.
Here, the relationship between the amount of elastic deformation and the fastening force is shown in the graph of FIG. As shown in the graph, the amount of elastic deformation and the fastening force have a proportional relationship. That is, when the amount of elastic deformation increases, the fastening force increases proportionally. The fastening force is an axial force of the tapered male thread portion 21 generated by screw tightening.

  Therefore, based on the proportional relationship between the elastic deformation amount and the fastening force, the fastening force can be obtained by converting the elastic deformation amount detected by the laser displacement meter 5. The amount of elastic deformation at which a target fastening force can be obtained is calculated in advance, and the external thread portion 21 may be rotated until this amount of elastic deformation is obtained. The elastic deformation amount detected by the laser displacement meter 5 is input to the control device 8, the elastic deformation amount is converted into a fastening force and output, and the target fastening force is based on the output value. You may make it rotate the external thread part 21 until is obtained.

Thus, according to the present embodiment, the amount of elastic deformation of the fastening portion 3a provided with the female screw portion 32 is detected, and the fastening force is determined from the detected amount of elastic deformation based on the proportional relationship between the amount of elastic deformation and the fastening force. By converting the above and managing the fastening force of the female screw portion 32 and the male screw portion 21, it becomes possible to easily and accurately manage the fastening force. Therefore, by using this management method and apparatus, it is possible to reliably avoid damage to the fastening member due to excessive tightening of the taper screw 1 and leakage of internal fluid due to insufficient tightening.
In addition, since the laser displacement meter 5 is used for detecting the elastic deformation amount of the fastening portion 3a, the elastic deformation amount can be detected with high accuracy without being affected by the vibration of the taper screw. It becomes.

  Since the fastening force of the taper screw can be managed easily and with high accuracy, the present invention is suitably used for fastening various pipes through which fluid flows, such as hydraulic pipes, water pipes, air pipes, etc. be able to.

DESCRIPTION OF SYMBOLS 1 Tapered screw 2, 3 Piping member 3a Fastening part 5 Laser displacement meter 6, 7 Sensor 8 Control apparatus 10 Fixing member 11 Imaging apparatus 12 Control apparatus 21 Male thread part 31, 32 Female thread part

Claims (5)

Fastening of the taper screw that manages the fastening force between the taper female thread portion formed on the inner peripheral surface of the hollow cylindrical fastening portion and the taper male screw portion or the parallel male screw portion screwed to the taper thread portion In the power management method,
The amount of elastic deformation in which the outer diameter of the fastening portion is increased is detected, and the detected amount of elastic deformation is converted into a fastening force based on the proportional relationship between the amount of elastic deformation of the fastening portion outer diameter and the fastening force, and the taper is performed. A method for managing a fastening force of a taper screw, comprising managing a fastening force between a screw portion and the tapered male screw portion or the parallel male screw portion.   2. The method for managing a fastening force of a taper screw according to claim 1, wherein an elastic deformation amount of the outer diameter of the fastening portion is detected by a laser displacement meter. Fastening of a taper screw that manages the fastening force between a taper female screw portion formed on the inner peripheral surface of a hollow cylindrical fastening portion and a taper male screw portion or a parallel male screw portion screwed into the taper screw portion. In the power management device,
Detection means for detecting the amount of elastic deformation in which the outer diameter of the fastening portion is expanded, and a control device in which the proportional relationship between the amount of elastic deformation of the fastening portion outer diameter and the fastening force is stored,
A taper characterized in that the control device converts the elastic deformation detected by the detecting means into a fastening force based on the proportional relationship between the elastic deformation of the fastening portion outer diameter and the fastening force, and outputs the fastening force. Screw fastening force management device.   4. The taper screw fastening force management device according to claim 3, wherein the detecting means is a laser displacement meter that detects an elastic deformation amount of an outer diameter of the fastening portion.   4. The taper screw fastening force management device according to claim 3, wherein the taper screw is a pipe taper screw provided in a pipe joint.

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