JP2003156012A - Fixture for setting clamping force, and its setting method - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide a fixture for setting a clamping force with high reliability and its setting method that can set an accurate clamping force and prevents the clamping force from changing over a long use. SOLUTION: This fixture for setting the clamping force comprises a fastener nut that is used for a fastener 9 comprising a screw stem body 10 and the nut 11 and is temporarily fixed to a clamped body T, a pressing tool 12 comprising a receiving surface part 12a penetrated through by the screw stem body at an interval with this nut and a bent piece part 12b of which tip end abuts on one surface of the clamped body, an oil nut 1 that is penetrated through by the screw stem body projecting from the pressing tool and applies pressure corresponding to a predetermined clamping force to the clamped body via the pressing tool, and a reception nut 13 for regulating a position in the reaction direction of the oil nut. The temporarily fixed nut is butted to the clamped body to provide a clamping force setting state by the clamping force.

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a tightening force setting jig for setting a predetermined tightening force on an object to be fastened, and a method of fastening an object to be fastened using the jig for tightening force setting.

[0002]

2. Description of the Related Art For example, as shown in FIG. 9, there is a case where a tightening tool K is used to fasten and fasten a tightened body T in which a plurality of rigid plate bodies t are superposed. The fastener K is composed of a combination of a bolt and a nut, or a combination of a screw rod a which is one screw rod (rod) as shown in the figure and two nuts b.

After inserting the threaded rod a into the object to be tightened T, each nut b is screwed to the threaded rod a protruding from both ends of the object to be tightened T, and the object to be tightened T from both sides.
Fasten and fix.

At this time, a tool such as a spanner is hung on one of the nuts b to hold the nut b so as not to rotate, and the other nut b is hung on to rotate and tighten the tool. Usually, both nuts b cannot be seen at the same time, and it is necessary to work while looking at each one, which is very troublesome. And
Since the number of screw rods a is usually large with respect to one tightened body T, workability is poor.

Alternatively, as shown in FIG. 10, there is no particular reference, but in the case of a long body Ta to be tightened, and the intervals between the tightening portions S formed at both end portions are extremely long, or work in the surrounding area. As a fastener Ka to be applied when the space is limited and the screw rod a cannot be passed by one piece, a connector c and two sets of screw rods a used at both end portions of the connector c. And nut b.

That is, in the case of a long object Ta to be tightened and the interval between the tightening portions S is large, if the long screw rod is used as it is, a large diameter thick object is held in order to maintain the rigidity of the screw rod. Must be adopted, which increases the weight and adversely affects the cost.

Therefore, a screw rod a has been used only at each tightening portion S of the object to be fastened Ta, and a fastener Ka in which a connecting member c is interposed between these screw rods a has come to be used. Of course, a bolt may be used as the screw rod.

By adopting the above-mentioned connecting tool c, necessary strength can be maintained and the divided parts can be fastened, but when the nut b is screwed, one nut b is held so as not to rotate,
There is no change in rotating and tightening the other nut b, which is very troublesome and poor in workability.

[0009]

In the fasteners K and Ka having any structure, there must be no difference in tightening force (to be exact, tightening torque: torque) for each fastener. That is, it is necessary to fasten and fix all the fasteners K and Ka to the fastened bodies T and Ta with the same fastening force.

A torque wrench is a jig for managing the tightening force of the fasteners K and Ka. This torque wrench is designed so that when the resistance of the tightening force becomes larger than the set torque value, the torque wrench idles and is not tightened any more. Alternatively, the resistance of the tightening force (tightening torque) is indicated by a needle on the scale on the torque wrench.

As shown in FIG. 11, the resistance value of the tightening force is determined by the friction resistance state in the threaded portion m between the male screw formed on the threaded rod a and the female screw formed on the nut b, and the nut b. Is determined by the frictional resistance state at the contact portion n between the tightening target T and Ta.

That is, the shape accuracy of the male screw and the female screw is determined by industrial standards, etc., but the screwing contact state is slightly different due to manufacturing errors. Then, there are various cases such as a case where lubricating oil is attached to the screw portion, a case where cutting oil is attached at the time of manufacturing, or a case where nothing is attached.

Further, as the nut b is tightened, the frictional resistance at the contact portion n between the nut b and the objects T and Ta to be tightened increases. From this, the frictional resistance is different when the surface of the tightened object is rough and when it is smooth.

Therefore, even if an attempt is made to obtain a constant tightening force with a torque wrench, the resistance of the tightening force is different due to the difference in the conditions described above. As a result, an accurate tightening force cannot be obtained.

Recently, as a fastener used in a marine engine or a nuclear power generation facility, there is an example of a bolt having a rod-shaped shaft without a screw and a so-called hydraulic nut.

That is, the rod-shaped shaft portion of the bolt is inserted through the two flanges, and the bolt head is brought into contact with one flange. A hydraulic nut is inserted through the bolt shaft portion projecting from the other flange, and one end surface of this hydraulic nut is brought into contact with the flange.

In this state, a predetermined hydraulic pressure is applied to the hydraulic nut. The position of the hydraulic nut itself with respect to the bolt shaft portion does not change, and a part of the hydraulic nut projects and presses the flange.
That is, both flanges are tightened with a predetermined tightening force.

By using such a hydraulic nut, the tightening force can be set relatively easily and accurately without the need for screwing work, and the workability and the tightening force setting accuracy can be improved. .

Even if there are many tightening points,
Attach a hydraulic nut to each bolt shaft and apply hydraulic pressure at the same time. Tightening is done at the same time, and there is no variation in tightening force.

However, the hydraulic nut, like a normal nut, is a consumable item that is left with the flange fastened and fixed. Since the hydraulic nut is more expensive than the normal nut, the cost is adversely affected.

Further, after the predetermined hydraulic pressure is applied, the hydraulic pressure is locked and held, but there is a possibility that the hydraulic pressure may delicately escape during long-term use. When a large number of hydraulic nuts are used, the degree of hydraulic pressure loss varies depending on the hydraulic nuts. That is,
The tightening setting force varies. Low reliability in long-term use.

Therefore, an object of the present invention is to set an appropriate tightening force for a nut when a member to be fastened is fastened using a fastener consisting of a threaded rod body having a threaded portion and a nut. It is another object of the present invention to provide a jig for setting the tightening force of a body, and another object of the present invention is to fasten an object to be fastened with an appropriate tightening force using the above-mentioned tightening force setting jig and with good workability. An object of the present invention is to provide a fastening method for an object to be fastened.

[0023]

In order to solve the above problems, the present invention has the following features.

[1] At least one side is provided with a threaded portion, and the threaded rod attached to the fastened body and the threaded portion of the threaded rod protruding from the fastened body are screwed to fix the fastened body. A tightening force setting jig used for a fastener consisting of a fastening nut, comprising a receiving surface portion having an insertion portion through which the screw rod is inserted, and a leg portion continuously provided to the receiving surface portion, A state in which the screw rod projecting from the fastened body is inserted into the insertion portion, and the leg portions are in contact with the outer surface of the fastened body so that the receiving surface portion is separated from the fastened body by a predetermined distance. A pressing member arranged so as to be held by the screw rod, a main body having an insertion hole through which the screw rod is inserted, and a pressing member that can advance and retreat in the axial direction with respect to the main body. Screw protruding from the part A body is inserted through the insertion hole, and the pressure body is arranged in such a state that the pressure body abuts the receiving surface portion of the pressure acting tool and can apply a pressing force, and the insertion hole of the pressure body. And a receiving nut screwed to the threaded portion of the screw rod protruding from the jig.

[2] A method for fastening an object to be fastened by a fastening tool, which uses the fastening force setting jig including the pressing tool, the pressure applying tool, and the receiving nut according to the above [1],
A first step of mounting a threaded rod body having a threaded portion on at least one side to a fastened body, and screwing a fastening nut in a temporarily fixed state to the threaded portion of the threaded rod projecting from the fastened body; , By pressing the fastening nut by arranging the pressing member such that the threaded rod projecting from the fastened body is inserted into the insertion portion and the legs are in contact with the outer surface of the fastened body. A second step of positioning at least the receiving surface portion between the receiving surface portion of the action tool and the outer surface of the body to be fastened, and the pressure applying tool from the insertion portion of the pressing action tool into the insertion hole thereof. A third step of arranging in such a state that the projecting screw rod is inserted and the pressing body is brought into contact with the receiving surface portion of the pressing device to apply a pressing force, and protruding from the insertion hole of the pressure applying device. Receiving nut on the threaded part of the screw rod A fourth step of screwing and bringing the receiving nut into contact with the main body of the pressure applying tool, and a pressing body of the pressure applying tool with respect to the main body so as to press the receiving surface portion of the pressing member. A fifth step of applying a pressure corresponding to the tightening force by advancing it and a state in which pressure is applied by the pressure applying tool, and the fastening nut is manually tightened on the outer surface of the object to be fastened. A sixth step of abutting, and the receiving nut from the screw rod body,
And a seventh step of sequentially removing the pressure applying tool and the pressing action tool.

[3] A pair of screw rods each having a threaded portion on at least one side and attached to both sides of the fastened body, and a pair of screw rods projecting from the fastened body, each having an end portion inserted therethrough. Tool and the threaded portions of both screw rods projecting from the end of the connecting tool, respectively, and tighten and fix the fastened object by tightening between the side part of the fastened object and the end of the connecting tool. A jig for tightening force used in a fastener composed of a pair of fastening nuts, comprising a receiving surface portion having an insertion portion through which the screw rod is inserted,
A pressing member attached to the connector at a position separated from the end of the connector by a predetermined distance, a main body having an insertion hole through which the screw rod is inserted, and an axially reciprocable body. Such that the screw rod protruding from the insertion portion of the pressing member is inserted into the insertion hole, and the pressing member abuts the receiving surface portion of the pressing member to apply a pressing force. A jig for tightening force setting, comprising: a pressure applying tool arranged in a simple state; and a receiving nut screwed to a threaded portion of the screw rod body protruding from the insertion hole of the pressure applying tool. .

[4] A method for fastening an object to be fastened by a fastening tool, using the fastening force setting jig including the pressure acting member, the pressure applying tool and the receiving nut according to the above [3]. The first step of attaching the threaded rods having the threaded portions to the side portions to the respective side portions of the fastened body, and inserting both the threaded rods projecting from the fastened body into the respective end portions of the connector, A second step in which one of the screw rods is inserted through the insertion portion of the pressing member, and a fastening nut is screwed in a temporarily fixed state to the screw portions of both screw rods projecting from the end of the connector. The pressure applying tool is configured such that the screw rod projecting from the insertion portion of the pressing action member is inserted into the insertion hole, and the pressing body abuts the receiving surface portion of the pressing action member to apply a pressing force. And the third step of placing in a state A fourth step of screwing a receiving nut onto the threaded portion of the screw rod projecting from the insertion hole of the pressure applying tool and bringing the receiving nut into contact with the main body of the pressure applying tool; and pressing the pressure applying tool A fifth step of applying a pressure corresponding to a tightening force to the fastened body via the connector by advancing the body with respect to the main body so as to push the receiving surface portion of the pressing action member; A sixth step of bringing the fastening nut into contact with the end portion of the connecting tool by a manual tightening operation in a state where pressure is applied by the pressure applying tool, and sequentially removing the receiving nut and the pressure applying tool from the screw rod body. 7. The method for fastening an object to be fastened, which comprises the step 7).

[0028]

BEST MODE FOR CARRYING OUT THE INVENTION Embodiments of the present invention will be described below with reference to the drawings. FIG. 1 (A) is a schematic perspective view of a hydraulic nut 1 which is a pressure applying tool constituting a tightening force setting jig, and FIG. 1 (B) is a schematic sectional view of the hydraulic nut 1. The hydraulic nut 1 is a nut body 2
And the pressing body 3. The nut body 2 has an outer peripheral portion 2a and a hollow portion 2b, and has a columnar shape in which the bottom surface portion 2c is closed and the upper surface portion 2d is open on the hollow portion 2b side. A connection port body 4 that communicates with a hydraulic pressure source (not shown) is provided on the outer peripheral portion 2a.

The inner peripheral surface of the hollow portion 3a of the pressing body 3 is movably fitted into the outer peripheral surface of the hollow portion 2b of the nut body 2.
The upper and lower end surfaces 3b and 3c of the pressing body 3 are hermetically sealed, and the peripheral surface 3d is movably fitted into the upper surface opening 2e of the nut body 2.

The space between the nut body 2 and the pressing body 3 serves as an oil storage chamber 5 and is filled with the pressing oil. No matter how the hydraulic nut 1 is tilted, the nut body 2
It has a complete seal structure so that oil does not leak from the contact portion between the pressing body 3 and the pressing body 3.

A protrusion 6 is provided on the bottom surface 2c of the nut body 2, and the bottom surface 3c of the pressing body 3 is provided without applying hydraulic pressure.
Appears. At this time, the upper surface portion 3b of the pressing body 3 is designed to be substantially the same as or slightly protrude from the upper surface portion 2d of the nut body 2.

When the hydraulic pressure is applied, the hydraulic pressure is applied to the bottom surface portion 3c of the pressing body 3, and the pressing body 3 projects from the upper surface portion 2d of the nut body 2. Even in this state, since the complete seal structure is formed between the nut body 2 and the pressing body 3, there is no oil leakage.

As shown in FIG. 2 to FIG. 4, a tightening body T having a plurality of plate bodies (rigid bodies) t superposed on each other is a fastening member consisting of a screw rod 10 which is a screw rod (rod) and two nuts 11. A method of setting the tightening force by using the tightening force setting jig W of the present invention will be sequentially described on the assumption that the tightening and fixing is performed at 9.

Since the body to be tightened T is a rigid body, even if a tightening force is applied, the body itself does not deform at all. As the fastener 9, a screw rod and two nuts may be used instead of a bolt and one nut as a screw rod without any problem.

The tightening force setting jig W is composed of the hydraulic nut 1 which is a pressure applying tool, the pressing tool 12 and the receiving nut 13 which is a receiving tool. The pressing tool 12 has a horizontal receiving surface portion 12a and a bent piece portion 12b bent downward at substantially right angles from both side edges of the receiving surface portion 12a, and is formed in a U-shaped cross section. The receiving surface portion 12a is provided with an insertion hole (not shown) into which the screw portion of the screw rod 10 protruding from the tightened body T is inserted.

The bent piece portion 12b is formed to have a dimension longer than the thickness of the nut 11, and is attached so that the tip edge of the bent piece portion 12b abuts on the body T to be tightened. Therefore, the position of the nut 11 can be freely set between the tightened body T and the receiving surface portion 12a.

The receiving nut 13 is an ordinary commercial product, like the nut of the fastener. Further, the screw rod 10 projects from both ends of the tightened body T, and the nuts 11 can be screwed into the respective screw portions.

The threaded rod 10 needs to have such a length that the pressing tool 12, the hydraulic nut 1 and the receiving nut 13 constituting the tightening force setting jig W can be attached to one nut 11 side.

FIG. 2A shows the first step, the second step,
The third step and the fourth step are shown. FIG. 2B shows
The 5th process is shown. As a first step, a plurality of plate bodies t are overlapped with each other, and a body T to be tightened in which a gap exists between the plate bodies t before being tightened.
Then, the screw rod 10 is inserted.

A nut 11 constituting a fastener 9 is screwed into one screw portion (lower side in the figure) of the threaded rod 10 protruding from the object to be tightened T, and is screwed in until it comes into contact with the object to be tightened T. This work may be a so-called hand tightening work of rotating the nut by hand. When the screw rod 10 is a bolt, the head of the bolt is on the lower side and comes into contact with the lower surface of the tightened body T.

A screw rod 10 protruding from the tightened body T
A nut 11 constituting the fastener 9 is screwed into the other threaded portion (upper side in the drawing) of the above, but at this time, the nut 11 is lightly contacted with the object T to be tightened or is temporarily fixed with some distance. .

As the second step, the screw rod 10 is inserted through the insertion hole provided in the receiving surface portion 12a of the pressing member 12. At this time, if the receiving surface portion 12a of the pressing tool 12 comes into contact with the nut 11 at a position where it is raised too much, the nut 11 is turned to bring it closer to the tightened body T. In short, the bending piece 12b of the pressing tool 12 as shown in the figure.
It suffices for the tip edge to contact the tightened body T.

In the third step, the hydraulic nut 1 is inserted through the threaded rod body 10, and in the fourth step, the receiving nut 13 is screwed. The hydraulic nut 1 is shown in FIG.
The upper surface 2d, 3b of the nut body 2 and the pressing body 3 is turned upside down from the state shown in FIG.
It is placed on the receiving surface portion 12a. It should be noted that there is no problem even if the hydraulic nut 1 is attached without changing the top and bottom.

The receiving nut 13 may be brought into contact with the hydraulic nut 1 as a manual tightening operation. From this, the hydraulic nut 1 includes the pressing tool 12 and the receiving nut 1
It is interveningly fixed between 3 and 3.

As the fifth step, a predetermined hydraulic pressure corresponding to the tightening force to be set is applied to the hydraulic nut 1.
Therefore, the pressing body 3 receives the hydraulic pressure and tries to move in the direction in which it projects from the nut body 2.

The hydraulic nut 1 is interposed between the pressing member 12 and the receiving nut 13, and the receiving nut 13 regulates the position of the hydraulic nut 1 in the reaction force direction, while the pressing body 3 projects. The tightened body T in the direction is the plate body t
Since there is a gap between them, the pressing body 3 projects.

Moreover, the nut 1 is provided on the side surface of the body T to be tightened on the side opposite to the side where the tightening force setting jig W is attached.
1 and the position of this side surface is regulated. Therefore, the pressing body 3 projects by α mm as much as the gap α mm formed between the plate bodies t of the tightened body T disappears.

As described above, by applying a predetermined hydraulic pressure to the hydraulic nut 1, the plate member t forming the object to be tightened T firmly adheres, and the same operation as the tightening with the set tightening force is achieved. receive.

FIG. 3A shows the sixth step, and FIG.
(B) shows an intermediate state of the seventh step. As a sixth step, the nut 11 on the upper side, which has a gap with the upper surface of the body T to be tightened due to the protrusion of the pressing body 3, is brought into contact with the body T to be tightened by a manual tightening operation. At this time, do not use a tightening tool such as a spanner. As a matter of course, when the tightening tool is used, the tightening force on the object T to be tightened varies, and the use of the tightening force setting jig W becomes meaningless.

As a seventh step, the hydraulic pressure applied to the hydraulic nut 1 is released. The pressing body 3 protruding from the nut main body 2 returns to the inside of the nut main body 2 again, and this time, a gap α for the protrusion of the pressing body 3 is formed between the hydraulic nut 1 and the receiving nut 13.

FIG. 4 shows the state where the seventh step has been completed. The tightening force setting jig W including the receiving nut 13, the hydraulic nut 1 and the pressing member 12 is removed from the screw rod 10. Therefore, the work is completed and the process is completed.

After all, in terms of work, the tightening force setting jig W is attached to and detached from the screw rod 10, and the nut 11 is used.
Hand tightening work and applying hydraulic pressure to the hydraulic nut 1,
The hydraulic pressure should be released. Both are extremely light work,
Avoid using nerves.

Moreover, the tightening force is set extremely accurately. Unlike the conventional hydraulic nut, the hydraulic pressure is not held in a locked state, so that no looseness occurs and high reliability is obtained. As a reminder, a double nut will not cause any changes over a very long period of use, even under shock conditions.

Although the handling of the tightening force setting jig W for one screw rod 10 has been described above, the handling of the jig for a large number of screw rods is exactly the same.

That is, for all the screw rods 10,
The first, second, third, and fourth steps shown in FIG. 2A are performed. Next, when hydraulic pressure is applied to the hydraulic nuts 1 in the fifth step shown in FIG. 2 (B), the connection ports 4 of all the hydraulic nuts 1 are communicated with the hydraulic pressure source, and all the hydraulic nuts 1 are connected. Apply hydraulic pressure at the same time.

Even if there are a large number of screw rods 10,
It is possible to simultaneously set extremely accurate tightening force in each tightening force setting jig W, and there is no fluctuation of the tightening force even during long-term use.

Next, as shown in FIGS. 5 to 7, although there is no particular standard, the screw rod body is used when the space between the tightening portions S of the object to be tightened Ta is large or the work space in the periphery is limited. A case will be described in which a single product cannot be passed. The object Ta to be tightened is a solid ta that is a rigid body and is long or thick.

The fastener 20 used here is composed of a connector 21 which will be described later, a screw rod body 10 composed of two screw rods (rods), and four nuts 11.
There is no problem even if bolts are used as the screw rod, in which case only two nuts are required.

As the tightening force setting jig Wa for setting the tightening force of the fastener 20, the hydraulic nut 1 which is the pressure applying tool and the receiving nut 13 which is the receiving tool are used, As a substitute for the pressing tool 12, the connector 21 that constitutes the fastener 20 is also used.

Of the upper and lower screw rods 10, the screw rod 10 on the upper side in particular is not only the two nuts 11, but also a part of the connecting tool 21 and the hydraulic nut 1 that constitute the tightening force setting jig Wa. And the length which can attach the receiving nut 13 is required.

The connecting tool 21 has a rectangular upper end surface portion 21a, a lower end surface portion 21b, and upper and lower end surface portions 21.
A side plate portion 21c that connects a and 21b is provided. The side plate portion 21c is provided only with a pair of opposing side portions of the upper and lower end surface portions 21a and 21b, and the other opposing side portions are open.

Upper and lower end surface portions 21a, 2 of the side plate portion 21c
A reinforcing plate 21d is integrally provided at a position separated from 1b and parallel to each other. Through holes (not shown) are provided to face each of the upper and lower end surface portions 21a and 21b and the upper and lower reinforcing plates 21d. Therefore, the connector 21 is formed so that the upper and lower parts are symmetrical with respect to the center in the vertical direction, and it is not necessary to confirm the vertical direction in use.

FIG. 5A shows the first step, the second step,
The third step and the fourth step are shown, and the fifth step is shown in FIG.

As a first step, a long tightened body T
The above-mentioned connecting tool 21 is interposed between the tightening portions S in a. At this time, from before being tightened,
There is a gap between the solids ta.

As a second step, the fastening portion S on the lower side of the drawing and the connecting tool 21 are connected. That is, the tightening portion S of the tightened body Ta and the lower end surface portion 21 of the connecting tool 21.
Insert the threaded rod 10 into b and attach the nut 11 to each.
Is tightened by hand.

In the figure, the nut 11 on the upper side is connected to the connecting tool 21.
The screw rod 10 is screwed to the lower end surface portion 21b of the
Project above the lower reinforcing plate 21d, and place the nut 11
May be screwed on.

As a third step, the tightening portion S on the upper side and the upper part of the connecting tool 21 are connected. The screw rod 10 used here has a long length as described above, and the upper portion thereof projects from the upper surface of the tightening portion S and the nut 11 is screwed thereto.

The lower end of the threaded rod 10 is inserted through the upper end surface portion 21a of the connecting tool 21, and the nut 11 is screwed. Further, the screw rod 10 is inserted through the reinforcing plate 21d on the upper side and is projected to the lower side.

The screw rod 1 on the upper side will be described later.
Since the position of the connecting tool 21 does not change when 0 moves downward, there is a possibility that the nut 11 on the connecting tool 21 side particularly contacts the upper reinforcing plate 21d. Therefore, the nut 11 is previously brought into contact with the upper end surface portion 21a. As a matter of course, manual tightening work is sufficient, and the tightening portion S and the connecting tool 21 are temporarily fixed.

As the fourth step, the above-mentioned hydraulic nut 1 is inserted into the screw rod 10 projecting from the upper reinforcing plate 21d of the connecting tool 21, and the receiving nut 13 is attached by hand tightening. The hydraulic nut 1 is mounted in the same vertical direction as that described with reference to FIGS. 1A and 1B, but there is no problem even if the hydraulic nut 1 is turned upside down.

The hydraulic nut 1 is fixedly interposed between the upper reinforcing plate 21d of the connecting tool 21 and the receiving nut 13. From this, the upper side reinforcing plate 21d is connected to the connecting tool 21.
Constituting the receiving surface portion of.

As a fifth step, a predetermined hydraulic pressure corresponding to the tightening force to be set is applied to the hydraulic nut 1.
Therefore, the pressing body 3 receives the hydraulic pressure and tries to move in the direction in which it projects from the nut body 2.

The hydraulic nut 1 is interposed between the receiving surface portion 21d and the receiving nut 13, and the receiving surface portion 21d regulates the position of the hydraulic nut 1 in the reaction force direction.
The tightened body Ta in the protruding direction of the pressing body 3 is a solid ta.
Since there is a gap between them, the pressing body 3 projects.

Moreover, the tightening portion S on the opposite side (lower side) to which the tightening force setting jig Wa is attached and the connecting tool 21 are fastened and fixed, and their positions are regulated. For this reason, the pressing body is β by the amount of β mm where the gap formed between the solids ta of the tightened body Ta disappears.
mm project.

That is, when a predetermined hydraulic pressure is applied to the hydraulic nut 1, a plurality of solids ta constituting the object Ta to be fastened firmly come into close contact with each other, and the same action as tightening with a set tightening force is exerted. .

FIG. 6A shows the sixth step,
(B) shows an intermediate state of the seventh step. As a sixth step, by applying hydraulic pressure to the hydraulic nut 1, the connecting tool 21
The nut 11 separated from the upper end surface portion 21a is brought into contact with the upper end surface portion 21a by a manual tightening operation.

As a seventh step, the hydraulic pressure applied to the hydraulic nut 1 is released. The pressing body 3 protruding from the nut body 2 returns to the inside of the nut body 2 again, and this time, a gap β corresponding to the protrusion of the pressing body 3 is formed between the hydraulic nut 1 and the upper side reinforcing plate 21d.

FIG. 7 shows the end state of the seventh step. That is, the receiving nut 13 and the hydraulic nut 1 are removed from the screw rod 10. The connector 21 is a component of the tightening force setting jig Wa, but also a component of the fastener 20, so that it remains as it is. Therefore, the work is completed and the process is completed.

After all, in terms of work, the work of attaching and removing the hydraulic nut 1 and the receiving nut 13 to the screw rod 10, the work of manually tightening the fastener nut 11, and the hydraulic nut 1 are performed.
It is sufficient to apply hydraulic pressure to and release the hydraulic pressure. Both are extremely light work and do not require nerves.

Moreover, the tightening force is set extremely accurately. Unlike the conventional hydraulic nut, the hydraulic pressure is not held in a locked state, so that no loosening occurs and high reliability can be obtained. As a reminder, a double nut will not cause any changes over a very long period of use, even under impact.

Similarly, even when there are many tightening portions S of the tightened body Ta, by applying hydraulic pressure to all the hydraulic nuts 1 at the same time, the same and accurate tightening force can be set for all the tightened bodies Ta at the same time. The tightening force does not change even after long-term use.

FIG. 8 shows the results of the conventional example and the example of the present invention when the tightened body with the load cell sandwiched is tightened with the screw rod and the nut having different screw surfaces. In the conventional example, the nut is tightened with the torque wrench.Although the setting of the torque wrench was constant, there were variations depending on the state of the screw surface, but by tightening according to the present invention, A constant tightening force was obtained regardless of the condition.

[0083]

As described above, according to the present invention, it is possible to accurately set the tightening force with respect to the object to be tightened, and moreover, the tightening force does not fluctuate even during long-term use and the reliability is improved. An effect such as being able to be achieved is achieved.

[Brief description of drawings]

FIG. 1 is a schematic perspective view and a cross-sectional view of a hydraulic nut showing an embodiment of the present invention.

FIG. 2 is a view showing the same embodiment and sequentially explaining a configuration of a tightening force setting jig for a tightened body and steps of a tightening force setting method.

FIG. 3 is a view showing the same embodiment and sequentially explaining steps of a tightening force setting method following the state of FIG. 2;

FIG. 4 is a view showing the same embodiment in a state where a final process is completed.

FIG. 5 is a view for sequentially explaining the configuration of a tightening force setting jig for the object to be tightened and the steps of the tightening force setting method according to another embodiment of the present invention.

FIG. 6 is a view showing the same embodiment and sequentially explaining steps of a tightening force setting method following the state of FIG. 5;

FIG. 7 is a diagram showing the same embodiment in a state in which a final process is completed.

FIG. 8 is a view showing the same embodiment and comparing characteristics of tightening results of a conventional method and the present invention.

FIG. 9 is a view for explaining a conventional tightening state for an object to be tightened.

FIG. 10 is a view for explaining a tightened state of the conventional body in another form to be tightened.

FIG. 11 is a view for explaining conventional frictional resistance generated between the tightening tools and between the tightening tools and the object to be tightened.

[Explanation of symbols]

T, Ta ... Object to be tightened, 10 ... screw rod, 11 ... nuts, 9, 20, ... Fasteners, 12a, 21d ... Receiving surface portion, 12b ... bent part, 12 ... Pressing tool, 1 ... Hydraulic nut (pressure applying tool), 2 ... nut body, 3 ... Pressing body, 13 ... Receiving nut (receiving tool).

   ─────────────────────────────────────────────────── ─── Continued front page    (72) Inventor Shibunobu             1-5-20 Kaigan, Minato-ku, Tokyo Tokyo Gas             Within the corporation (72) Inventor Etsuro Tanaka             1-5-20 Kaigan, Minato-ku, Tokyo Tokyo Gas             Within the corporation (72) Inventor Shozo Hatanaka             1-2-1, Marunouchi, Chiyoda-ku, Tokyo             Main Steel Pipe Co., Ltd. (72) Inventor Fukuda             1-2-1, Marunouchi, Chiyoda-ku, Tokyo             Main Steel Pipe Co., Ltd. (72) Inventor Hiroyuki Horikawa             1-2-1, Marunouchi, Chiyoda-ku, Tokyo             Main Steel Pipe Co., Ltd. (72) Inventor Mayumi Toshiyuki             1-2-1, Marunouchi, Chiyoda-ku, Tokyo             Main Steel Pipe Co., Ltd. (72) Inventor Shintaro Inoue             88 Ono-cho, Tsurumi-ku, Yokohama-shi, Kanagawa Japan             Steel Pipe Construction Co., Ltd. F term (reference) 3J022 DA11 EA41 EB01 EC02 FB12                       GA06 GA10 GA14 GA21 GB90

Claims (4)

[Claims] 1. A screw rod provided on at least one side of the screw rod, the screw rod being attached to an object to be fastened, and the screw rod of the screw rod projecting from the subject to be fastened. A tightening force setting jig used for a fastener comprising a fastening nut, comprising a receiving surface portion having an insertion portion through which the screw rod is inserted, and a leg portion continuously provided to the receiving surface portion. While the screw rod protruding from the fastening body is inserted into the insertion portion, and the leg portion is brought into contact with the outer surface of the fastened body, the receiving surface portion is separated from the fastened body by a predetermined distance. A pressing member arranged so as to be held, a main body having an insertion hole through which the screw rod is inserted, and a pressing member that can advance and retreat in the axial direction with respect to the main body, and the insertion portion of the pressing member. The screw rod protruding from the A pressure applying tool which is inserted into the insertion hole and is arranged in such a state that the pressing body contacts the receiving surface portion of the pressing member to apply a pressing force, and the pressure applying tool is projected from the insertion hole of the pressure applying tool. And a receiving nut screwed to the threaded portion of the screw rod. 2. A method of fastening an object to be fastened by a fastening tool, which uses a fastening force setting jig having a pressing tool, a pressure applying tool, and a receiving nut according to claim 1, wherein at least one side portion Attaching a threaded rod having a threaded portion on the side to the fastened body, and screwing a fastening nut in a temporarily fixed state to the threaded portion of the threaded rod protruding from the fastened body; and the pressing action. The fastening nut is received by the pressing tool by arranging the tool in a state where the screw rod projecting from the body to be fastened is inserted into the insertion portion and the legs are in contact with the outer surface of the body to be fastened. A second step in which at least the receiving surface is not in contact with the surface portion and the outer surface of the body to be fastened; and the screw for projecting the pressure applying tool into the insertion hole of the insertion part of the pressing member. The rod is inserted and the pressing body presses A third step of arranging so as to be able to apply a pressing force by abutting on the receiving surface portion, and a receiving nut is screwed onto a threaded portion of the screw rod protruding from the insertion hole of the pressure applying tool, A fourth step of bringing the receiving nut into contact with the main body of the pressure applying tool, and advancing the pressing body of the pressure applying tool relative to the main body so as to press the receiving surface portion of the pressing action tool,
A fifth step of applying a pressure corresponding to a tightening force to the fastened body, and a sixth step of bringing the fastening nut into contact with the outer surface of the fastened body by a manual tightening operation while the pressure is applied by the pressure applying tool. And a seventh step of sequentially removing the receiving nut, the pressure applying tool, and the pressing action tool from the screw rod, the method for tightening an object to be fastened. 3. A pair of threaded rods, each of which has a threaded portion on at least one side thereof and is attached to both sides of the fastened body, and two threaded rods projecting from the fastened body. And the threaded portions of the two threaded rods projecting from the end of the connecting tool, respectively, and tighten the space between the side of the object and the end of the connecting tool to fix the object to be fastened. A tightening force setting jig used for a fastener composed of a pair of fastening nuts, comprising a receiving surface portion having an insertion portion through which the screw rod is inserted, and a predetermined distance with respect to the end portion of the connector. The pressing action member attached to the connecting tool at a separated position, a main body having an insertion hole through which the screw rod is inserted, and a pressing body axially advancing and retracting with respect to the main body are provided. The screw rod protruding from the insertion portion A pressure applying tool that is inserted into the insertion hole and is arranged in such a state that the pressing body contacts the receiving surface portion of the pressing member to apply a pressing force, and the pressure applying tool projects from the insertion hole of the pressure applying tool. And a receiving nut screwed to the threaded portion of the screw rod. 4. A method of fastening an object to be fastened by a fastening tool, which uses a fastening force setting jig comprising a pressing member, a pressure applying tool, and a receiving nut according to claim 3, wherein at least one side portion The first step of attaching the threaded rods provided with threaded portions to the respective side portions of the fastened body, and inserting both the threaded rods projecting from the fastened body into the respective end portions of the coupling tool, and either one of them is inserted. A second step of inserting the threaded rod of (1) into the insertion part of the pressing member, and screwing a fastening nut to the threaded portions of both threaded rods protruding from the end of the connecting tool in a temporarily fixed state; The pressure applying tool is placed in a state in which the screw rod projecting from the insertion portion of the pressing action member is inserted into the insertion hole, and the pressing body is in contact with the receiving surface portion of the pressing action member to apply a pressing force. The third step of placing, and the pressure A fourth step of screwing a receiving nut onto the threaded portion of the screw rod projecting from the insertion hole of the applicator and bringing the receiving nut into contact with the main body of the pressure applier; By advancing with respect to the main body so as to press the receiving surface portion of the pressing member,
A fifth step of applying a pressure corresponding to a tightening force to the object to be fastened through the connecting tool, and an end of the connecting tool by manually tightening the fastening nut in a state where pressure is applied by the pressure applying tool. A method for fastening an object to be fastened, comprising: a sixth step of abutting against a portion; and a seventh step of sequentially removing the receiving nut and the pressure applying tool from the screw rod.