JPS58163811A - Predetermined-torque clamping nut device - Google Patents

Abstract

(57) [Summary] This bulletin contains application data before electronic filing, so abstract data is not recorded.

Description

[Detailed Description of the Invention] The present invention uses a constant torque tightening nut that is tightened with a constant tightening torque by its own torsional destruction, and has completely implemented constant torque tightening for the nut. To provide a constant torque tightening device 1 to a device having both a display function for determining whether the torque is fixed and a function for preventing careless loosening work after constant torque tightening and facilitating torque management.

As shown in Fig. 1, the constant torque tightening nut has a constant torque breaking part Nb (!) by carving a circumferential groove Nd in the axial middle of the nut body N, and the constant torque breaking part Nb (! This is used to perform a constant torque tightening 1 in conjunction with the tightening operation of the Fli portion Nb.

1, that is, Pole], [screwed into 3 and the part to be fastened]) L
f In the tightened state, by rotating the protruding nut part NO separated by the circumference @Nd with a tool, tighten the nut part 1 to part NF to be clamped and fixed to the part to be fastened. A rotational force is generated to torsionally destroy the constant torque fracture portion Nb.This torsional fracture defines the maximum tightening torque of the C fixed side nut portion NF.

In addition, according to the structure of this example, the spiral hole NS that is screwed into the pole I-F3 is made from the front two parts of the neck 1 to the main body N. - After the torque breaking portion Nb is broken, that is, after constant torque tightening, a slight rotational drive is further applied to provide a locking effect similar to that seen in a so-called double nut that prevents rotation of the fixed side nut portion NF. I can do it.

However, even though Natsu has such excellent characteristics, he is not without problems.

That is, one of the problems is that it may be relatively difficult to determine whether or not a set nut has been tightened to a constant torque. For example, when a large number of nuts are set and they stand on a fastened part, it is easy to forget to tighten them, and it is very difficult to find the nuts that have been forgotten to tighten. Furthermore, it is very difficult to judge the tightened state when the nut is set at a high place.

In particular, when the nut part mentioned above uses a tool on the nut body to perform constant torque tightening (=j), the nut part that operates the IJ is used both for constant torque tightening and as a lock nut. These are the presence or absence of destruction of the constant torque fracture portion and the presence or absence of rotational deviation between the nut portions, which are slight changes, making it even more difficult to judge whether or not tightening is complete.

In addition to such problems of forgetting to tighten, there may be cases where the tightening operation is once performed but the constant torque is not fully tightened, in other words, the tightening is done half-heartedly. It's easier to overlook than if you forgot to put it on.

Another problem is that even if constant torque tightening is carried out according to formal procedures, there is a possibility that it may be loosened artificially, and even if there is a fact that it has been tightened, if it is re-tightened, the appearance will be poor. This is expected to be a dangerous situation in which it may not be possible to tell the difference, and the person may become aware of it later when an accident occurs.

The basic purpose of the present invention is to solve these problems of the nut itself, and for that purpose,
The basic concept is to provide a tightening incomplete display means on the side of the nut that operates constant torque tightening using a tool, and a loosening prevention means on the nut fixed to the fastened part]-
It is used to capture and provide a torque tightening nut device.

By the way, although several specific proposals have been made regarding such constant torque tightening nut devices, none of them have sufficiently solved the problem.

For example, one method is to machine a screw hole in the fixing nut part of the nut body, but the hole in the operating side nut part is a hollow hole with a diameter larger than the threaded part of the bolt, and it is tightened to a constant torque. A structure is adopted in which the operating side nut part is separated and removed after the rupture part is broken, and a collar is fitted around the outer circumference of the fixed side nut part to prevent loosening, and one operating side nut part is coated with red etc. There is a device with colored paint that has the same effect as the danger sign (Utility Model Publication No. 55-90899ε).
.

According to this device, the change in state before and after constant torque tightening can be obtained by the presence or absence of the painted and colored operation side nut part, so it can be clearly distinguished, and it is easy to find a nut that has not been completely tightened. Separation and removal of the operating side nut section is a major premise, and restrictions must be placed on the nut structure. Therefore, this device cannot be applied to a nut that also has a locking action as shown in FIG. 1, and is therefore ineffective.

In addition, since the means to indicate that the tightening is incomplete is painting on the thick surface, it is time consuming and is easy to peel off because it is exposed all the time, during or after the actual tightening work. There is a lack of certainty as it is displayed as incomplete. In particular, when checking the tightening condition from a distance from the nut mounting position, there is a possibility of erroneous judgment if there is no clear indication.

On the other hand, apart from that, apply a collar to the entire length of the nut body in the axial direction.
There is an example of W. In this method, a single cuff with a relatively large axial length is attached to the fixed side button 1~ part and the operating side nut part so as to straddle the constant torque rupture part, and there is a perforation in the axial direction of the collar. It forms a weak point that can be easily broken and separated, and when the constant torque breaking part is twisted and broken based on the twisting and turning of the operating part, the weak part is also destroyed incidentally, thereby destroying the operating side NAND part. The state of completion of tightening is indicated by separating and removing a part of the upper collar, and the remaining part of the collar is used to prevent loosening on the fixed side nut ( Utsukai Showa 55-1717
No. 13).

According to this device, there is no need to require a special shape for the nut itself in order to indicate that the tightening is incomplete, and the display can be done with simpler man-hours than in the case of painting and coloring. It is not possible to identify the color because it is attached as a single unit to the fixing nut.

For example, if the weak point is bordered by red or other danger markings on the operating side nut, and blue or other safety markings on the stationary side nut, confirmation of the tightening status will be more reliable, but such color coding is not recommended. This requires partial winding of colored tape and repainting, which is time consuming and, like the above-mentioned device, also causes the problem of peeling.

Furthermore, since the weak point is damaged in order to separate and remove the collar, there is a risk that the collar may be removed if it is not handled with care, leading to a risk of erroneous tightening operations later. By the way, if the collar is partially removed from the beginning of Cera 1, it will show a state similar to that of completion of tightening, and therefore there is a possibility that constant torque tightening may not be carried out.

The present invention fully overcomes the drawbacks of the prior art and provides an improved constant torque tightening nut device which reliably achieves the original purpose.

That is, the device of the present invention is provided with a constant torque breaking part in the axial middle, a fixing nut part to be fastened to the fastened part on one side, and a fixing nut part on the other side.
J is a nut body with an operating nut part for constant torque tightening GJ, which is engaged with the outer periphery of the fixed nut part [/J
A specified loosening prevention collar and a tightening incomplete display collar fitted and engaged on the outer periphery of the operating nut section are provided, and the loosening prevention collar and the tightening incomplete display collar are mutually connected. The present invention is characterized in that a rotary engagement/disengagement mechanism is provided between them, which engages and holds each other before the constant torque rupture portion breaks, and disengages each other after the rupture portion breaks.

In the above device, the loosening prevention collar covers the periphery of the fixing nut and fixes it to provide a surface shape that is difficult to cut with tools.For example, it is a cylinder with a hole inside that engages the outer surface of the nut. It is desirable to make it t″′・L tc
=: (D:/) 5-'i constant t-/L/'y after tightening 7) Since the inside remaining on top cannot be loosened, it serves as a safety indicator. For this reason, a plastic molded body colored in a safe color, such as blue or green, is suitable.

On the other hand, the color for indicating that the tightening is not completed is desired to have a shape that increases the display surface for the operator on the nut, and is also desired to be made of a light material since it will fall off during the tightening operation. Also, if it remains, it will be a danger indicator of failure to tighten. For this reason, it is preferable to use a plastic molded body colored with a danger sign, for example, red.

The rotational engagement and disengagement mechanism provided between the loosening prevention collar and the tightening incomplete display collar indicates that each independently molded collar is engaged in the rotational direction on a predetermined nut. This is based on the premise that the locking and release are performed at the breaking of the constant torque rupture portion, that is, when the constant torque tightening is performed. Engagement refers to the case where free mutual movement of the collars in opposite directions is stopped, and release refers to the case where the movement is released. The attachment or release of these is determined only by the presence or absence of rotational deviation between the colors.

The rotary engagement/disengagement mechanism determined in this manner is obtained, for example, by the relationship between pawls and grooves, and an engaged state can be created based on mutually intersecting or overlapping in the radial direction. The released state is achieved by creating a hole or notch for releasing the engaged state at a position where the collar 1: has some degree of rotational deviation due to rotation during the tightening operation from the position where the engaged state is created. can have

A more detailed explanation will be given below with reference to the drawings of the embodiments.

Reference numeral N indicates the main body of Nara 1, CA indicates a collar for preventing loosening, and CB indicates a collar for incomplete tightening.

Various shapes and structures can be considered for the nut body N, but L
As for the embodiment of the strike, what is shown in FIG. 1 applies. In other words, by radially cutting the hexagonal columnar body N in which the helical hole NS has been machined over the entire axial length and carving the circumference mNd, a constant torque breaking part Nb with a small thickness and small torsional stress is created. One hexagonal part separated by the circumferential groove Nd is connected to the fixing nut part NF to the part to be fastened, and the other hexagonal part is used for constant torque tightening.

The operation key is 1" 81i No.

FIGS. 2 to 6 show a first embodiment of a device constructed using such a nut.

The tightening prevention collar CA is obtained by an annular body whose axial length is the same as that of the fixing nut part NF, and has a hexagonal hole 1 inside for engaging and fixing the outer body of the nut part NF. The outer surface has a rounded shape with no protrusions. In actuality, the collar CA is fixed to the nut part NF by, for example, making the diameter of the hole 1 slightly smaller than the outer diameter of the body of the nut part NF to provide a dimensional tolerance, and using this tolerance to fix the collar CA to the nut part NF. This can be obtained by forcibly inserting it into the nut part NF to create a so-called interference fit. Since the collar CA is made of plastic material, it has some elasticity compared to a nut, and this elasticity helps maintain the tight fit.

However, in addition to utilizing such dimensional tolerances, a method of bonding and integrating the hole 1 and the nut portion NF with an adhesive is also fully applicable.

On the other hand, the color CB for indicating completion of tightening is obtained by a disk-shaped body in order to increase the display area, and the center of the disk has a hexagonal hole 2 that can be engaged with the outer periphery of the body of the operating nut part No. have Hole 2 has a diameter slightly larger than the outer diameter of the body of nut part No. because the collar CB will be removed later.
The collar CB is designed to be loosely fitted onto the nut part NO. Since the two-piece collar CB is in the form of a disc, even when it is inserted into the nut part NO, the nut part No is partially exposed, allowing direct engagement with a tool.

A rotary engagement/disengagement mechanism is provided between phase n of the collars CA and Cs of such people, and this point will be described below.

First of all, from the top of the color CB board, you can see the arms divided into multiple parts.
3.3 on the same circumferential orbit at equal intervals (center point spacing 12r)
'), and inside one of the collars CA there is an enlarged hole 4 into which the arm is received and rotatably fitted.
It is formed. Between the enlarged hole 4 and the mutually rotating surfaces of the arms 3 and 3.3, the holes 4 are provided with claws 5 and 5 in the same circumferential orbit corresponding to the arms 3 and 3.3, respectively. Grooves 6, 6.6 are provided at equal intervals to protrude in the radial direction, extend in the circumferential direction, and are perforated in the radial direction on the surface of each of the arms 3, 3.3.

Claws 5 and 5.5 are when colors CA and CB are officially compatible (
For constant torque tightening, use arms 3 and 3 (when attached to the previous nut).
．． It is provided in a position that wraps around the protruding position of 3,
Therefore, when the arms 3, 3.3 are fitted into the enlarged holes 4 and the respective collars CA, Co are positioned on their respective nuts, the claws 5.5. 6 and is designed to be inserted and secured.

In actuality, when the collars CA and CB are connected to each other, the arm 3, 3.3 is inserted into the enlarged hole 4 through between the claws 5.5.5, and the collars CA and C8 are connected to each other. Rotate to fit and engage the claws 5, 5.5 into the grooves 6, 6, 6, and align the hexagonal holes 1 and 2 properly (so that they can be fitted into the respective nuts), thereby temporarily setting them. . By engaging and attaching the collar CA to the outer periphery of the fixing nut part NF in the above-described manner in this temporarily set state, a state in which the other collar CB is fitted onto the operating nut part NO is obtained.

Therefore, the collar CB has a claw 5.5 whose mutual movement in the axial direction with respect to the operating nut NO is constituted by the mating collar CA.
．． 5 and grooves 6.6. ．． 6, and mutual movement of the grooves 6, 6°6 in the circumferential direction of one pawl 5.5.5 is obstructed by the engagement in the rotational direction with the nut portion NO. Ru.

The release of such two mutual inhibitions is done by color CA.
, rotational deviation of Co phase U (that is, Nara 1 part NF).

This can only be achieved by rotational deviation of the NO phase rj).

The tightening work for the device having the following configuration is carried out as follows.

First, screw the main body N into the bolt B (see Figure 1) to the J° 1, press the fixing nut 1 to the part NF to be connected, and then use a tool (spanner, box wrench, etc.). Hook it onto the operating nut part NO and tighten it by pulling C.

When a predetermined torque is reached by this tightening, the constant torque breaking portion Nb is torsionally broken, so that the fixed rat portion NF stops rotating and provides a predetermined tightening pressure to the fastened portion. Thereafter, by further rotating the operating nut part NO slightly, a locking effect is exerted on the fixed nut part Nr-, and at the same time, the locking action is caused by the mutual rotational deviation between the stationary collar CA and the collar CA which rotates in conjunction with the rotational operation. 5, 5.5 are rotated out of the grooves 6.6.6, and the axial engagement of the collar CB is released. Therefore, the color Cs for indicating incomplete tightening can be removed by pulling it out in the axial direction of the nut, and by removing it, it is possible to express the state of proper tightening at the end of all tightening operations. be.

In particular, the collar C^ for preventing loosening is difficult to see when the tightening operation is incomplete due to the large protrusion in the radial direction of the collar 08 for indicating incomplete tightening, but it is easy to see after performing constant torque tightening. It is an exposed item, and if the color CA is given a safety display color, the expression of a good tightening state can be made even clearer.

On the other hand, according to the device in which constant torque tightening is performed in this way, the loosening prevention collar 〇A remains, so the tool cannot be engaged with the fixing nut part NF, and the constant L and torque tightening state can be maintained. . In the unlikely event that the fixing part nut NF is loosened, it will be necessary to remove the collar C^, or even if you do not remove it, the collar CA will be scratched by the tool attachment, so be careful as loosening will leave traces. It can be evoked.

Furthermore, in addition to the operation nut part No. after the rupture of the constant torque rupture part Nb, 1-, 3f (the rotation is required to be at least 20 degrees or more in order to cause the locking effect, therefore, the pawl 5) In addition to this, the engagement range of 6 should be set at an angle of 20 degrees or larger, and if there is no color CI after the locking effect is achieved by doing so.
+ cannot be removed and a locking action will always occur.

In the case of this embodiment, after the tightening is completed, a predetermined gap is formed in the hexagonal body part C and F by the enlarged hole 4 between the fixing nut part NF and the loosening prevention collar CA. In particular, it is impossible to insert a regular box wrench into the gap shown in A, because the protruding claws 5, 5゜5. By separately preparing a machined special box wrench or the like with a recess that fits 5.5, it is possible to check the torque and actually check whether or not constant torque tightening is being performed. In this case, it is preferable that the rotation angle applied to the operating nut NO is 60 degrees so that the wrench attached to the fixed nut NF can be operated through the operating nut NO.

FIG. 7 shows a second embodiment of the present invention.

In this device, the outer shape, fixing or engagement method, etc. of the loosening prevention collar CA, which is attached and fixed to the fixing nut NEF, and the tightening incomplete display collar CB, which is inserted on the operating nut part NO, are the same as in the previous embodiment. I actually agree with this, but color CA,
Modification @B is given to the rotational engagement/disengagement mechanism between CB. This point will be discussed below.

First, a disk portion 10 is formed that projects outward in the radial direction from the axial circumferential edge of the loosening prevention collar C^, and the disk portion 10 and the disk portion of the tightening incomplete display collar CB are located at opposite sides of each other. , two arms 11.11 from the disc part 10 are 180
The claws 12 and 12 are provided protrudingly on the same circumferential orbit at intervals of °, and claws 12 and 12 bent at right angles are formed at the tips of the claws 12 and 12, and the hexagonal hole 2 of one of the hexagonal holes 2 of the color ○a for indicating incomplete tightening is formed. The peripheral part has up to two slots 13.13 drilled in correspondence with the arms 11.11 on a circular-circumferential track.

The slot 13.13 allows the arm 11.11 to pass through, but the claw 12°12
a first vortex hole 13a having a width that does not allow passage of the vortex in the axial direction;
13a and its slots 13a, 13a! ! ? The arms 11, 11 and the claws 1 are formed on the counterclockwise side when viewed from the front of the unit.
2.12 Second slot 13b with a width that allows both to be inserted in the axial direction
, 13b, and are set at positions rotationally symmetrical to the center of the collar CB.

When the collars CA and CB are facing each other so that each side of the hexagonal hole is aligned on the same axis 7 (in the mounting position on the collar 1~ before the tightening operation), the arms 11 and 11 are attached to the first slot. 13
a, the claw 12 is inserted through the terminal end of 13a.
．． 12 protrudes from the collar CB and is on the plate surface of the collar CB.Therefore, when the collars CA and Ca are positioned on a predetermined nut part, the collar CB faces with the disc part 10 and the claw 12. It is clamped, thereby preventing movement in the axial direction.

In actuality, when the collars CA and Cs are attached in a connected state, the arm 11.11 is passed through the second slots 13b, 13b of the slot 13.13, and the claw 12.12 is projected to the opposite side. , In that state, rotate the collars CA and CB mutually and insert the arms 11° 11 into the first W4 holes 13a, 13.
a, and temporarily set the respective hexagonal holes so that they correspond properly (so that they can be fitted into the respective nuts). In this temporarily set state, the collar CA is fitted onto the fixing nut part NF and engaged and fixed, so that the other clamped collar CB is fitted onto the operating nut part No. A state is obtained in which it is held so as to be engaged with the hexagonal side surface.

By doing this, the arm 11.11 has the color Cs.
is rotationally engaged on the nut part No. and the first slots 13a, 13
The state in which the terminal end of a is biased and positioned is maintained, and the claw 12.12 is rotated to the second position only when the constant torque tightening is performed due to rotational deviation of the operating nut part No. with respect to the fixed nut part NF, that is, the constant torque fracture part is destroyed. It becomes possible to move to the slots 13b, 13b. Therefore, after tightening to a constant torque, the color CB for indicating incomplete tightening is released by applying rotation to the operating nut part No. in the tightening direction, and by pulling it out in the axial direction, the engagement tF action by the pawls 12 and 12 is released. Becomes Gukirushino. The constant torque applied to the operating nut part No. after the rupture part is rotated is used to induce a locking action on the fixed knot part. It is good to decide. For example, after the constant torque breaking part Nb is broken, the operation nut part N is necessary to make the nut parts have the same effect [ ].
As explained in the previous embodiment, the rotational deviation angle of O needs to be 20° or more, but the optimum range is 3C)° to 60°.
°. Therefore, in this case, the 21st full hole 13b, 13b
The position of the front end P1 of the first full hole 13a, which is connected to the first slot 13a, 13a is in the vicinity rotated by 30 degrees from the position of the terminal end P2 of the first full hole 13a, 13a, and 13
b.

The position of the rear end P3 of 13b is the first slot 13a.

The position is approximately rotated by 60 degrees from the position of the terminal end P2 of 13a.

FIG. 8 shows a further modified third embodiment of the device of the present invention.

Engagement and attachment fixation of collar CA for preventing loosening to fixing nut part NF and operation nut part N of collar Go for indicating incomplete tightening
The insertion and engagement with O is the same as in the two embodiments described above, but the outer shape and rotational engagement and disengagement mechanism have been modified.

First, the collar ○a for indicating incomplete tightening is a disc part 20 with a hexagonal hole 2 in the center for inserting into the operating nut part NO and rotating it into engagement. The cylindrical portion 21 is shaped by a cylindrical portion 21 extending from the loosening prevention collar 〇A to the collars CA and CB.
The surface area of the danger sign is increased by covering it loosely to allow mutual rotation between the two. Then, between the mutually rotating sides of the cylindrical part 21 and the loosening prevention collar ○A, two rod-shaped rods 22 and 22 are placed on the same circumferential orbit at 180° intervals from the outer surface of the loosening prevention collar C^. It is vertically protruded, and one cylindrical portion 21 has cutout grooves 23.23 corresponding to the rod-shaped portions 22.22. Notch shape? I! 23. 23 is a first groove 238° 238° formed by cutting a predetermined length in the axial direction from the edge between the cylindrical portions and forming a groove If. The second hole 23b is cut in the opposite direction when viewed from the cylindrical opening side (6 holes are formed).

2311 or r beat, these are rotationally symmetrical with respect to the central axis of the cylinder 1◇'? I is set.

When the collars C and CB are placed opposite each other so that each side of the hexagonal hole is on the same axis]-, the claws 22
,．． 22 is located at the terminal end of the second part 23b, 23b, and the claw 2 is connected to the second part 23b.
2.22 is the second full 23b.

23b to prevent mutual movement in the axial direction.

In order to reduce the backlash in the axial direction of collar 〇8, the second
The groove width of the grooves 23b and 23b is made almost the same as the thickness of the corresponding arm 22.22, or slightly more narrowly so as to allow movement of the arm 22.22 in the circumferential direction but restrict movement in the axial direction. It can be achieved by doing.

By doing this, the nails 22.22 are colored Cs.
is held in a biased position at the end of the second grooves 23b, 23b of the collar CA which is rotationally engaged and fixed on the operating nut NO, and the operating nut NO is held in a biased position on the fixing foot 1.
The pawls 22 and 22 do not move into the second grooves 23b and 23 until the constant torque fracture portion Nb rotates with respect to the portion NF.
b to the first grooves 23a, 23a.

Then, the claws 22.22 are connected to the first grooves 23a, 23a l.
When moved to 1lI, constant torque tightening is being performed, and the locking of the collar CB in the axial direction is released, allowing it to be pulled out and removed. Also, the operating nut part N
The rotation of the constant torque fracture portion Nb of O after the fracture can give a locking effect to the fixing nut NF. As in the embodiment, the terminal ends P of the second grooves 13t+ and 13b
If determined in conjunction with the range of IhS et al. 30' (P2) and -60° (P3), then J.

In the case of this embodiment, consideration has been given to allowing the torque brake to be used after tightening to a constant torque. In other words, loosening prevention 11
In the outer shape of the collar CA to the fixing nut part NF, the two corresponding sides of the hexagonal part are made into arcuate parts, and the remaining four sides are tightly engaged with the hexagonal side surfaces of the nut. , as a linear part, and bar-shaped parts 22 and 22 are respectively designed to project on the arc-shaped side surface, and a corner part is formed between the linear parts.

In this way, J, -, ) ” (color CA
Although normal tools cannot engage the arms 22,
, 22) The tightening torque can be actually confirmed by preparing only a special torque lens that has been machined into a shape that corresponds to the arc-shaped part.

In this embodiment, the collars 〇A and CB are attached to the nuts N in the same manner as in the previous embodiment.
, 23a and the second groove 23b.

23b and temporarily set it, and in this temporarily set state, fit it onto the nut and fix the position.

As is clear from the above explanation, the device of the present invention has a constant torque breaking part, and with the breaking part as a boundary, one side has a fixing nut part to the part to be fastened, and the other side has a constant torque tightening operation. For nuts with separate operating nut parts, the loosening prevention means installed on the fixing nut part and the tightening incomplete display means installed on the operating nut part are each configured with independently molded collars, so the shape of the nut is adjusted. There is no need to add any restrictions, coloring for identification is reliable and extremely easy, and the display direction for indicating incomplete tightening can be set arbitrarily and in a large size, making it easy to discover nuts that have not been tightened. It becomes easier. The loosening prevention collar on the fixing nut is engaged and fixed on the fixing nut in the rotational and axial directions, and the collar for indicating incomplete tightening is engaged on the operating nut in the rotational direction. It was discussed that the collars should be tightly engaged with each other by a rotary engagement/disengagement mechanism such as a combination of claws and grooves, and the fixed torque should not be tightened in order to make them irremovably engaged unless the rupture part is destroyed. Inadvertent peeling off of the completion indicating collar before constant torque tightening can be prevented, and therefore, failure can be reliably notified if constant torque tightening is not performed. In addition, since disengagement of the rotary engagement/disengagement mechanism becomes possible only when there is a rotational deviation of the nut phase lj, that is, a jam occurs at the constant torque breakage section, it is necessary to remove the color that clearly indicates that the tightening is not completed. This necessarily allows constant torque tightening ().

As described above, the device of the present invention solves the various problems that existed in the past, and achieves the initial purpose of ensuring the confirmation of the tightening history and facilitating the control of torque. The benefits are truly great.

[Brief explanation of the drawing]

Fig. 1 is a partially cut-out explanatory diagram showing an example of a constant torque tightening knot body, and Figs. 2 (a) and (b). (c) is a right side view, front view, and left side view showing the first embodiment of the nut device of the present invention; FIG. 3 is an exploded explanatory view of the device shown in the above figure; (a) is a collar for preventing loosening; is Natsuto's body, (
C) shows the color for indicating that the tightening is not completed. Figure 4 is a sectional view taken along the x-X line in Figure 1 (c), Figure 5 is a sectional view taken along the y-y line in Figure 1 (b), and Figure 6 is a sectional view of the same device after constant torque tightening. It is an explanatory diagram showing a state. Figure 7 (a), (b), (
8(a) is a plan view, a partially cutaway front view, and a bottom view showing a second embodiment of the nut device of the present invention; FIG. (B) and (C) are a plan view, a partially cutaway front view, and a bottom view showing a third embodiment of the nut device of the present invention. N: Nut part, Nb: Constant torque breaking part, NF: Fixing nut part, NO: Operation nut part, CA: Collar to prevent loosening, CB: Collar to indicate incomplete tightening, 5.12, 22: Claw, 6 : Groove, 13: Groove, 23: Notch groove. 21st J RoCμ

Claims (1)

[Claims] A nut body having a constant torque breaking part formed in the axially intermediate part, a fixing nut part for fastening to the fastened part on one side, and an operating nut part for constant torque tightening on the other side, outside the fixing nut part. a loosening prevention collar that is fitted and fixed in rotational and axial direction engagement, and a tightening incomplete display collar that is fitted onto the outer periphery of the operating nut portion so that it can be secured in the rotational direction; A rotary engagement/disengagement mechanism is provided between the loosening prevention collar and the tightening incomplete display collar, which engage and hold each other before the constant torque breaking portion breaks and release the engagement from each other after the breaking portion breaks. The constant torque tightening is characterized by a nut device.