JPH0413452Y2 - - Google Patents

Description

[Detailed Description of the Invention] (Industrial Application Field) The present invention relates to a nut that can generate a predetermined tightening torque.

(Prior art and its problems) For example, when constructing a large structure such as a bridge, many bolts and nuts that connect the steel members that make up the structure are insufficiently tightened based on the strength calculation of the structure. Or to prevent over-tightening,
Its tightening torque is specified.

Conventionally, in order to set the tightening torque of bolts and nuts as specified, an expensive torque wrench with a tightening torque adjustment mechanism was used to tighten the bolts and nuts until the specified tightening torque was reached. The torque wrench mentioned above is large and heavy, making it inconvenient to transport to places with poor footing such as high places.
The problem was that the workability was poor.

(Purpose of the invention) In view of the above conventional problems, the purpose of the present invention is to provide a nut that can generate a predetermined tightening torque using a large number of ordinary monkey wrenches available in the field. .

(Means for Solving the Problems) In order to solve the above conventional problems, the present invention provides a first nut member 4 that comes into pressure contact with the member to be tightened 1, and a nut member 4 that comes into contact with the first nut member 4. The nut 3 has a screw hole 10 integrally and continuously inserted through the center of both the nuts 4 and 5, and has a screw hole 10 integrally and continuously inserted through the center of both the nuts 4 and 5. Of the contact surfaces 6 and 7, one of the contact surfaces 7 has an engaging convex portion 9.
, an engagement recess 8 whose width L in the tightening direction is larger than the width l of the engagement protrusion 9 is provided on the other contact surface 6, and the engagement protrusion 9 is provided in the tightening direction of the engagement recess 8. By press-fitting the starting end side, both 4 and 5 are integrally connected, and when a predetermined tightening torque is applied to the second nut member 5, the press-fitting engagement force is released. The second nut member 5 is inserted into the engaging recess 8 with respect to the first nut member 4.
It was configured so that it moves relative to the terminal end side in the circumferential direction.

(Function) In the above configuration, by rotating and tightening the second nut member 5 with an adjustable wrench or the like, the first nut member 4, which rotates integrally with the second nut member 5, is brought into pressure contact with the member to be tightened 1, and the tightening force is maintained at a predetermined level. When the tightening torque reaches the tightening torque of
The press-fit engagement force is released, the second nut member 5 moves relative to the first nut member 4 in the circumferential direction, a predetermined tightening torque is obtained, and the engagement protrusion 9 is engaged. In order to prevent the second nut member 5 from moving more than necessary against the end surface 8c of the recess 8, the first and second nut members 4,
There is no risk of over-tightening. Moreover, the first nut member 4 and the second nut member 5 serve as a type of double nut, that is, a lock nut, and the synergistic action of both nut members 4 and 5 provides a locking effect.

(Example) A first example of the present invention will be described based on FIGS. 1 to 6. 1 and 2 show a state in which a nut 3 of this embodiment is screwed with a predetermined tightening torque to a bolt 2 passing through a plurality of members 1 to be tightened, such as steel materials, and the nut 3 is A first nut member 4 having a low height that comes into pressure contact with the member to be tightened 1;
and a tall second nut member 5 into which an adjustable wrench or the like is fitted, and both 4 and 5 are hexagonal with the same outer diameter, In the state before the tightening torque is generated, they are integrated and have the same appearance as a normal hexagonal nut, and after the specified tightening torque is generated, as shown in FIGS. 1 and 2, both 4, 5 are slightly shifted from each other. Note that the second nut member 4
The height _H1 is for fitting an adjustable wrench, etc.
It is set higher than the height _H2 of the second nut member 4. To give an example of specific dimensions, the height _H1 of the second nut member 5 is 9 to 18 mm, and the height _H2 of the first nut member 4 is 3 to 6 mm.

As shown in FIG. 3, among the abutting surfaces 6, 7 of the two nuts 4, 5, in this embodiment, one or more, preferably three to three, are on the abutting surface 6 of the first nut member 4.
The engagement recesses 8 of 6 are arranged at predetermined angles in the circumferential direction,
An engaging protrusion 9 is bored in the radial direction and protrudes from the contact surface 7 of the second nut member 5 to be press-fitted into the engaging recess 8, as shown in FIGS. 4 to 6. , the above-mentioned two 4, 5 are integrally connected by the mutual press-fitting engagement force of these engaging concavo-convex portions 8, 9. As shown in FIG. 4, the engagement recess 8 is rectangular in plan view, and its width L in the tightening direction A is set to be larger than the width l of the engagement protrusion 9, for example, about twice. In the state before the predetermined tightening torque is generated, as shown in FIG. has been done. Then, as shown in FIG. 6, the inner surface 8a of the engagement recess 8 is made into a downwardly tapered surface,
When the engagement convex portion 9 is press-fitted into the engagement concave portion 8, both side surfaces 9a of the engagement convex portion 9 are strongly pressed against the inner surface 8a of the engagement concave portion 8, and the engagement concave portion 8 , 9 is made to have a sufficiently large press-fitting engagement force.

The press-fit engagement force is determined by various conditions such as the area and press force of both side surfaces 9a of the engagement convex portion 9, and the coefficient of friction between the engagement concave and convex portions 8 and 9. By setting, the press-fitting engagement force, that is, the predetermined tightening torque of this nut 3 can be set. Further, the tightening torque increases until the engagement convex portion 9 comes into contact with the terminal end side 8c of the engagement recess 8 and the movement of the second nut member 5 is restricted. By appropriately selecting the width L in the tightening direction, it is possible to set the upper limit value of the predetermined tightening torque.

To give an example of the sizes of the engagement concave and convex portions 8 and 9, when the height of the nut 3 is approximately 13 to 16 mm, the width L of the engagement concave portion 8 is 1 to 5 mm, and the width of the engagement convex portion 9 is approximately 13 to 16 mm. l is 0.5
~2.5 mm, and the height h of the engaging convex portion 9 is approximately 0.5 ~ 3 mm.

To explain the manufacturing procedure of the nut 3, first the first nut member 4 and the second nut member 5 are manufactured separately using a nut former, and then the engaging protrusion 9 is press-fitted into the engaging recess 8 using a press. Both 4 and 5 may be integrated by engaging with each other, and then a screw hole 10 may be continuously and integrally provided in the center of both 4 and 5, as shown in FIG.

When tightening the member to be tightened 1, use the nut 3, which has the same appearance as a normal nut, to tighten the member to be tightened 1.
The first nut member 4 is pressed against the member to be tightened 1 by screwing it into the bolt 2 passing through the bolt 2, holding the second nut member 5 with an adjustable wrench, etc., and rotating it. When the tightening force reaches a predetermined tightening torque, the press-fitting engagement force of the engaging concave and convex portions 8 and 9 is overcome by the predetermined tightening torque and is released, and the engaging convex portion 9 is in the state shown in FIG. 4a. As shown in Figure b, the tightening direction A shifts to the front side, and the
As shown in the figure, the second nut member 4
It is possible to visually detect that the nut member 5 has shifted in position and that a predetermined tightening torque has been obtained.

Also, due to the movement of the second nut member 5, the second
Although the tightening torque of the nut member 5 increases,
Since the engagement protrusion 9 hits the terminal end side 8c of the engagement recess 8 and the movement of the second nut member 5 is restricted, by finishing the tightening at that point,
It is possible to prevent the first and second nut members 4 and 5 from being overtightened.

In addition, the first nut member 4 and the second nut member 5 act synergistically to function as a locking nut and exhibit a strong locking action.

In the above embodiment, the engagement recess 8 was formed on the first nut member 4 side, and the engagement protrusion 9 was provided protruding on the second nut member 5 side. The second nut member 5 is provided with an engaging convex portion 9 protruding from the
An engagement recess 8 may be formed on the side. Furthermore, although the engagement uneven portions 8 and 9 are square-shaped, they may have other shapes, such as cylindrical or spherical shapes. Furthermore, although the engaging convex portion 9 is formed integrally with the second nut member 5, the engaging convex portion 9 may be a separate member and implanted in the second nut member 5.

In the above embodiment, the first nut member 4 is made into a hexagonal shape having the same outer shape as the second nut member 5. The reason why the first nut member 4 is made into a hexagonal shape having the same external shape as that of the second nut member 5 is because it detects that a predetermined tightening torque is obtained and the second nut member 5 is shifted. This is to make it easier to use, and its outer shape may be circular, for example. In this case, in order to make it easier to detect the transition of the second nut member 5, a mark is provided from the outer surface of the second nut member 5 to the outer surface of the first nut member 4, and the positional shift of this mark will cause the predetermined It is desirable to be able to detect when a tightening torque of

In the above embodiment, as shown in FIG. 4, both inner surfaces 8a of the engaging recess 8 are formed parallel to each other when viewed from above, but as shown in FIG. It may be formed on a tapered surface that tapers toward the end (second embodiment).

According to this configuration, the predetermined tightening torque can be increased compared to the first embodiment described above.

As shown in FIG. 8a, the inner surface 8 of the engagement recess 8
A protrusion 11 is provided in the center of a, and when a predetermined tightening torque is reached, the protrusion 11
Alternatively, the engaging convex portion 9 may push away and shift (third embodiment).

According to this configuration, a predetermined tightening torque can be obtained by appropriately setting the size of the protrusion 11.

FIG. 9 shows a fourth embodiment of the present invention, in which a first nut member 4 and a second nut member 5 are connected.
In this embodiment, among the mutual contact surfaces 6 and 7 of
A circular recess 15 is formed in the center of the abutting surface 6 of the first nut member 4, and at least one, preferably 3 to 6, engaging recesses having a triangular vertical cross section are formed around the recess 15. 8 are bored at predetermined angles in the circumferential direction so as to communicate with the recess 15, and the cylindrical projections 16 fit into the recess 15 on the contact surface 7 of the second nut member 5; Engagement protrusions 9 having a triangular vertical cross section are integrally formed on the outer circumferential surface of the protrusion 16 and the abutting surface 7, and are press-fitted into each of the engagement recesses 8. The positional relationship between each engagement recess 8 and engagement protrusion 9 is the same as in the first to third embodiments, so a description thereof will be omitted.

According to the nut 3 of this embodiment, by fitting the protrusion 16 into the recess 15, the first nut member 4 and the second nut member 5 can be made concentric, and the engagement protrusion Since the edge of the portion 9 facing the engagement recess is inclined, the engagement protrusion 9 can be easily press-fitted into the engagement recess 8 .

(Effects of the Invention) According to the present invention, the first nut member and the second nut member have a simple structure in which the first nut member and the second nut member are press-fitted into engagement with each other at the engagement uneven portion, and thus can be manufactured at low cost.

Furthermore, by tightening the second nut member until the second nut member moves relative to the first nut member in the tightening direction, a predetermined tightening torque can be obtained, and In addition to being able to reliably prevent bolts and nuts from loosening, the second nut member is regulated to prevent it from shifting more than necessary, thereby preventing damage to the threads of the bolts and nuts due to over-tightening. The tightening torque can be reliably kept within the specified range.

Further, by moving the second nut member relative to the first nut member in the circumferential direction, it plays the role of a so-called double nut, that is, a lock nut, and also exhibits a loosening prevention effect.

[Brief explanation of the drawing]

1 to 6 show a first embodiment of the present invention,
Figure 1 is a front view of the nut of the present invention screwed onto a bolt and the member to be tightened is tightened with a predetermined tightening torque, Figure 2 is a view taken from the - arrow in Figure 1, and Figure 3 is a An exploded perspective view of the same nut, Figures 4a and 4b are enlarged cross-sectional views of the main parts showing the procedure for generating tightening torque, Figure 5 is a view taken in the - arrow direction of Figure 4a, and Figure 6 is a view of Figure 4. It is a -arrow view of a. Figure 7 is the second version of this invention.
FIG. 8a, b is an enlarged sectional view of the main part showing the embodiment of
9 is an enlarged sectional view of essential parts showing a third embodiment of the present invention, and FIG. 9 is an exploded perspective view of a nut showing a fourth embodiment of the present invention. 1... Member to be tightened, 3... Nut, 4... First nut member, 5... Second nut member, 6,
7...Abutment surface, 8...Engagement recess, 9...Engagement protrusion, 10...Screw hole.

Claims (1)

[Scope of utility model registration request] a first nut member that presses against the member to be tightened;
A nut having a second nut member brought into contact with the first nut member, and having a threaded hole integrally and continuously penetrated through the central part of both of the nut members, the nut having a threaded hole integrally and continuously extending through the center of both of the nut members, Of the contact surfaces, one contact surface is provided with an engagement protrusion, and the other contact surface is provided with an engagement recess whose width in the tightening direction is larger than the width of the engagement protrusion, and the above-mentioned engagement By press-fitting the convex portion to the starting end side of the engaging recess in the tightening direction, the two are integrally connected, and when a predetermined tightening torque is applied to the second nut member, the press-fitting is performed. A nut configured such that when the engagement force is released, the second nut member moves relative to the first nut member in the circumferential direction toward the terminal end of the engagement recess.