JP2002155920A - Nut fastening and fixing structure - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide a nut fastening and fixing structure capable of easily obtaining the required fastening torque when fastening a nut for fixation to a cylindrical member provided with a male screw in the peripheral surface thereof and facilitated in the execution thereof without generating a looseness during a longtime use. SOLUTION: A male screw is provided in the peripheral surface of a cylinder or a column provided with a flange part 22,and the male screw part is provided with a vertical groove 21 in the axial direction, and a washer 27 provided with a vertical claw 31 to be engaged with the vertical groove 21 and a lateral claw 22 in a plane part thereof is fitted on the peripheral surface of the cylinder or the column in the condition that the vertical claw 31 is fitted in the vertical groove 21. A surface of the washer 27 opposite to the lateral claw 33 pinches a plate to be fixed between the flange 22, and a nut 29 provided with a recessed part to be engaged with the lateral claw 33 of the washer 27 in a nut surface thereof and to be screwed to the male screw is fastened to fit the lateral claw 33 in the recessed part.

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a nut fastening structure, in which a plate to be fixed is sandwiched between a flange and a nut by tightening the nut on a male screw provided on an outer peripheral surface of a cylindrical body. The present invention relates to a nut fixing structure for fixing.

[0002]

2. Description of the Related Art Filtration devices are used for water treatment of water supply and sewerage systems. In such filtration devices, strainers (nozzles) for collecting and distributing filtered water are widely used. That is, in a filtration device, a filter material such as sand is disposed on a flat filter bed plate, and water to be treated passes through the filter material and passes through a water collecting and distributing device (strainer) provided on the filter bed plate. The water is collected as filtered water in a pipe provided at the bottom of the filter bed plate. Also, when washing the filter medium in the filter device, conversely, water or air is sent from the pipe below the filter plate to the filter material above the filter plate through the water collecting and distributing device,
Used for backwashing of filter media. The strainer used as such a water collecting and distributing device is provided with a slit of a fine size that allows only filtered water to pass and does not pass through a filtering material, and is roughly divided into a vertical slit and a disk-type (horizontal) slit based on the shape of the slit. There are two types. In each case, these strainers are mounted through filter bed plates in the filtration device and serve the above-mentioned applications.

FIG. 5 shows a conventional method of fixing various strainers to a filter bed plate. (A) shows a method in which a strainer is fixed to a filter bed plate by screwing. A circular hole 12 is provided in the filter bed plate 11, and a female screw is arranged on the inner peripheral surface of the hole 12. The strainer 13 is provided with a vertical slit 15 at its upper part, and the lower pipe 16 is formed with an external thread on its outer periphery, and is screwed to the internal thread of the hole 12. Therefore, the strainer 13 can be directly fixed to the filter bed plate 11. However, when the water to be filtered is seawater or the like containing a considerable amount of salt, such a method cannot be adopted because the filter bed plate 11 is rubber-lined. (B)
Is a method in which a lower pipe is inserted into an end of the filter bed plate 11, the lower pipe is provided with a male screw on an outer peripheral portion thereof, and the filter bed plate (a flat plate) is sandwiched and fixed between the flange surface of the vertical slit 15 and the nut 17. It is. The nut 17 is provided with a female screw on the inner peripheral surface of the through-hole, and the female screw is screwed with a male screw provided on the outer peripheral surface of the lower pipe to be tightened. This method is a general method of fixing the strainer to the filter plate,
The shape of the nut is devised so that it can be easily tightened. (C) is a method in which the strainer is fixed to the filter bed plate with a nut as in (b), but is fixed with a double nut 18. Thereby, the strainer is more firmly fixed to the filter bed plate by the nut, and the loosening during use is reduced. (D) shows a method of fixing the strainer to the filter bed plate 11 by embedding the lower pipe 16 of the strainer to the lower surface of the vertical slit 15 with a mortar 19 or the like. However, this fixing method is not always easy to construct, and it is particularly difficult to remove the strainer, and there is a problem in maintenance.

In fixing the filter plate of the strainer,
In a method in which a male screw is provided in the lower pipe and the male screw is tightened with a nut, as described above, a double nut is employed as a measure for preventing the nut from loosening. However, fixing the strainer with the double nut uses two nuts, so the work of tightening the nuts is doubled, and the work efficiency is reduced. Further, even if the nut is tightened with a double nut, the nut may become loose due to long-term use.

[0005] In a filtration apparatus, not only a filtration step but also an air backwashing step, a water backwashing step, a simultaneous backwashing step with air and water, and the like are repeated. When these steps are repeated, the nut for fixing the strainer becomes loose, and the fixing of the strainer becomes unstable. If a gap larger than the designed value is created between the strainer and the filter plate, or between the disc strainers, the filter media in the filter will flow out to the collection and distribution pipe side, or the strainer will be clogged. However, there is a problem that filtration cannot be performed.

Therefore, even if the filtration device is operated for a long period of time, the nut for fixing the strainer to the filter bed plate does not come loose, and a method of fixing the strainer to the filter bed plate, which is easy to perform the work and further to perform maintenance and inspection, is desired. ing.

[0007]

SUMMARY OF THE INVENTION The present invention has been made in view of the above-mentioned circumstances, and when a male screw is fixed to a cylindrical member or the like provided on the outer peripheral surface by tightening a nut, a required tightening torque is required. It is an object of the present invention to provide a nut tightening and fixing structure which can be easily obtained, does not loosen even during long-term use, and is easy to construct.

[0008]

According to a first aspect of the present invention, an external thread is provided on an outer peripheral surface of a cylindrical body or a cylindrical body having a flange portion, and the externally threaded portion is provided with a longitudinal groove in an axial direction. Inserting a washer provided with a vertical claw engaged with a vertical groove and a horizontal claw on a flat surface so that the vertical claw fits into the vertical groove on an outer peripheral surface of the cylindrical body or the cylindrical body, and a horizontal claw of the washer. The opposite surface sandwiches the plate to be fixed between the flange and the flange, and tightens a nut that is screwed into the male screw provided with a concave portion on the nut surface to engage with the lateral claw of the washer. A nut fastening structure, wherein the nut is fitted into a recess.

[0009] When the vertical claws of the washer are fitted into the vertical grooves provided in the male screw portion such as the cylindrical body, the movement of the washer in the circumferential direction is prevented. The nut that is tightening the washer also has a concave portion on the engagement surface with the washer, and the lateral claw provided on the flat portion of the washer meshes with this, so that the nut also moves in the circumferential direction with respect to the washer. Is hindered.
Accordingly, when the nut is screwed into the male screw of the nut and tightened, the washer is fixed to the cylindrical body and the nut is fixed to the washer, so that the nut is prevented from loosening. By using the washer and the nut having such a configuration, a single nut can provide a more effective locking effect than a double nut, so that a stable tightening effect can be exerted even when a long-term load is applied.

According to a second aspect of the present invention, the width and depth of the vertical claw are determined so as to fit into the vertical groove, and the axial length of the vertical claw is equal to that of the external thread of the cylindrical surface. 2. The nut fixing structure according to claim 1, wherein the structure corresponds to several nuts. As a result, the vertical claws of the washer fit exactly into the vertical grooves of the nut, and the washer can be stably held.

According to a third aspect of the present invention, the lateral claw has an inclined surface having elasticity, and a plurality of the lateral claws are arranged on an engaging surface of the washer with the nut.
2 is a nut fixing structure. This allows
Since the side claws have elasticity, when tightening the nut,
The nut can be rotated smoothly by pushing the lateral claw to the plane position, and after tightening, the lateral claw can be fitted into the concave portion of the nut by a restoring force, so that the nut is prevented from loosening.

According to a fourth aspect of the present invention, the engaging surface of the nut with the washer has an N-shaped uneven surface, and the N-shaped uneven surface is inclined with respect to the inclined surface of the lateral claw. Are in the same direction. 4. The nut fastening structure according to claim 3, wherein Thus, when the nut is tightened, the nut can be smoothly rotated, and after the tightening, the rotation of the nut can be prevented by the engagement of the lateral claw with the concave portion of the nut surface.

According to a fifth aspect of the present invention, there is provided a filtering device wherein a water collecting and distributing device comprising a strainer or a nozzle is fixed to a filter bed plate by the nut fixing structure according to any one of the first to fourth aspects. It is. Thereby, when the strainer is fixed to the filter bed plate, a sufficient tightening torque is obtained, and a more stable locking effect than the double nut method is obtained. Further, since the fixing method is a single-nut fixing method, the work can be facilitated.

[0014]

DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS A nut fastening structure according to an embodiment of the present invention will be described below with reference to the drawings. The illustrated example relates to fixing a strainer as a water collecting and distributing device in a filter device to a filter bed plate. FIG.
FIG. 3 is a longitudinal sectional view showing a state in which a strainer is fastened and fixed to a filter bed plate. FIG. 2 shows a structural example of a washer, and FIG. 3 shows a structural example of a nut. Although this embodiment shows an example of a disk-type strainer, the method of fixing the strainer having a vertical slit to the filter bed plate is exactly the same.

A number of circular holes 12 are provided in a filter bed plate 11 which divides a filter chamber for accommodating a filter medium of the filter device, and a lower pipe 16 having a male screw is inserted into an outer peripheral surface of a strainer 13. The lower pipe 16 has fixed therein a branch pipe 19 connected to a main pipe for collecting filtered water or a main pipe for supplying cleaning water or cleaning air. The lower pipe 16 and the flange portion (bottom plate portion) 22 are integrally formed, and are formed using, for example, an engineering plastic material such as hard vinyl chloride. A pair of longitudinal grooves 21 is provided in the lower pipe 16 at the portion where the male screw is formed, along the axial direction.

The lower pipe 16 having an external thread on the outer periphery is
It is fastened and fixed to the filter bed plate 11 by a nut 29 via a locking washer 27. FIG. 2 shows an example of the structure of a locking washer, and a washer 27 is formed on a ring-shaped and flat plate-like plate as shown in FIG.
3 is provided. The vertical claw 31 has a ring-shaped washer 27.
1 protrudes upward from the inner peripheral surface shown in FIG. The width and depth of the vertical claw 31 are determined so as to fit into the vertical groove 21 provided in the lower pipe 16 of the strainer, and the length of the vertical claw 31 is formed into a thread corresponding to several external threads on the outer peripheral surface. It has an equivalent length. Eight horizontal claws 33 are provided on the flat surface of the washer 27 in the illustrated example, and are provided with an elastic inclined surface 33a protruding downward. The lateral claw 33 is adapted to fit into a concave portion provided on an engagement surface of a nut described later. That is, the width, length, inclination, position, and other dimensions of the lateral claw 33 are determined so that the nut 29 can be easily tightened and can easily enter the recess of the nut.

FIG. 3 shows a structural example of the nut. As shown in the figure, the nut 29 has a female screw 35 on its inner peripheral surface,
The lower pipe 16 is screwed with a male screw. A concave portion 37 is provided on the bottom surface (nut surface) of the nut 29, and after tightening the nut 29, the surface provided with the concave portion 37 engages with the surface of the washer 27 from which the lateral claw 33 projects. . Then, the concave portion 3 provided on the nut surface
7 is a concave-convex surface 37a having an N-shaped inclined portion and a U-shaped concave portion 37b for facilitating air release and passage of water.
It is composed of In the illustrated example, the U-shaped recess 3 is used.
7b are provided at four places. In this case, the width of the U-shaped recess 37b is smaller than the pitch of the N-shaped recess 37a. Further, the N-shaped uneven portions 37a are arranged continuously in this example, but may be arranged intermittently.

The N-shaped inclined surface provided on the nut surface of the nut 29 and the inclined surface of the horizontal claw 33 provided on the washer 27 are provided in the same direction. This makes it possible to tighten the nut 29 so that the N-shaped uneven shape of the nut surface slides against the inclined surface of the horizontal claw, and to use the N-shaped uneven shape 37a when the strainer is used after tightening. The vertical surface is locked to the lateral pawl, which prevents the nut 29 from loosening.

FIG. 4 shows a modification of the nut. Although the N-shaped uneven shape shown in FIG. 3 is continuous along the circumferential direction, in this embodiment, the N-shaped
Only the U-shaped recess 37c is provided. In the case where the material of the side claws of the locking washer has a high spring elasticity, a sufficient nut locking effect can be obtained only with a U-shaped passage for improving air bleeding and water passage. This recess 37c
FIG. 3 shows that the side claws 33 of the washer can be sufficiently accommodated.
May be larger than the size of the U-shaped recess 37b.

Next, a method for fastening the strainer to the filter bed plate will be described. The portion where the male thread of the lower pipe 16 of the strainer is formed is inserted into the strainer fixing hole 12 of the filter bed plate 11, and the flange portion 20 is disposed so as to be positioned on the upper surface of the filter bed plate 11 via the packing 20a. At this time, the male screw forming portion projects from the lower surface of the filter bed plate 11. Then, the vertical groove 21 of the lower pipe 16 in which the male thread is formed
The washer 27 is arranged so that the vertical claw 31 of the lock washer fits in and the upper surface of the washer 27 contacts the lower surface of the filter bed plate 11. Next, the locking washer 27
The nut 29 is screwed into the male screw of the lower pipe 16 so that the lower surface having the lateral claw 33 of the above and the nut surface provided with the above-described N-shaped uneven portion 37 of the nut face each other.

At the time of screwing, the locking washer 27 is fixed by fitting the vertical claw 31 into the vertical groove 21 provided in the lower pipe, and does not rotate when the nut 29 is screwed. When the nut 29 is tightened in this state, the N-shaped inclined surface of the uneven portion 37 of the nut 29 and the above-described inclined surface of the horizontal claw 33 of the washer 27 are in the same direction. And the nut can be tightened until the desired torque is obtained to secure the strainer to the filter plate. After tightening, the lateral claws having spring elasticity engage with the N-shaped recess formed on the nut surface, so that the nut does not rotate in the direction opposite to the tightening direction. As a result, after the nut is tightened, the nut is not loosened, and the strainer is maintained in a state of being firmly fixed to the filter bed plate even when used for a long time. With such a tightening structure, when the diameter of the lower pipe is M36, the locking effect is 20 to 35 Nm.

The tightening and fixing structure of the present invention is also useful as a tightening structure for a disk-type strainer in which the slit portion of the strainer is formed by a tightening body of several disks. As shown in FIG. 1, the disk type strainer 13 is formed by stacking several disks 23 so as to form fine slits, and a flanged nut 25 and a flanged nut 25 between a flange portion (bottom plate portion) 20 and a holding plate 24. It is fastened and fixed using the washer 36 and the nut 37 of the present invention. Here, a male screw 20a is formed on the outer peripheral surface of the cylindrical portion 20b integrally formed with the flange portion 20, and one or two rows of axial grooves 38 are provided.
Is formed so as to cross the male screw portion. Here, the diameter of the bolt portion of the male screw 20a is about M12 to M20,
By using the washer 36 having the shape shown in FIG. 2 and the nut 37 having the shape shown in FIG. 3, the locking effect is 5 to 15 Nm.
Degree is obtained. The tightening structure using the washer and the nut can be used between the holding plate 24 and the nut 25 with a collar. In this case, since the diameter of the locking washer can be increased, the locking effect is further improved. Is obtained. That is, when the nut fixed to the disk is loosened, the gap between the disks, that is, the slit width is changed. Therefore, by tightening with the above-mentioned washer and nut, a disk fastening structure for forming a slit that does not cause loosening can be obtained.

Next, a description will be given of the results of measuring the locking effect when the hard disk material is made of hard vinyl chloride (H-PVC) and the following specifications are used. Example of fixing the strainer to the filter bed plate Lower pipe diameter; M36 Vertical groove; 5 mm width x 2 locations Vertical nails: 5 mm long x 2 horizontal nails, 8 locations, 3 mm length Number of N-shaped uneven shapes of nuts; Continuous 36 peaks Measurement result: When tightening torque is 15-20Nm,
The loosening prevention effect was 20 Nm. The loosening effect was slightly larger than the tightening torque, indicating that there was a sufficient effect.

Example of disc holder Male screw bolt diameter; M16 Vertical groove; 3 mm width × 2 places Vertical claw; length 3.5 mm × 2 pieces, horizontal claw, 6 places, length 2.
Number of N-shaped concave and convex shapes of 5 mm nut; continuous 26 peaks Measurement result: When tightening torque was 10 to 14 Nm, 15 Nm was obtained as a locking effect. The loosening effect was slightly larger than the tightening torque, indicating that there was a sufficient effect.

In the above-described embodiment, the fixing of the strainer in which the lower pipe and the upper bolt are formed with external threads to the filter bed plate and the fixing of the disk plate have been described. Of course, the present invention can be widely applied to various structures in which a body or the like is fastened and fixed using a washer and a nut.

[0026]

As described above, according to the present invention, the nut can be easily fastened to a cylindrical body or the like having an external thread on the outer peripheral surface, and a large locking effect can be obtained. For example,
By applying the present invention to the installation and fixing of the water collecting and distributing device of the filtration device to the filter bed plate, the water collecting and distributing device can be firmly fixed to the filter bed plate, and a high locking effect can be obtained, and the installation work is also easy. become. Such a nut fixing structure of the present invention is not only for fixing the strainer of the filtration device,
It is useful for tightening and fixing a nut to a structure having an external thread on an outer peripheral surface of a wide variety of cylindrical bodies or the like.

[Brief description of the drawings]

FIG. 1 is a cross-sectional view showing a state in which a disk type strainer according to an embodiment of the present invention is installed on a filter bed plate.

2A is a plan view, FIG. 2B is a cross-sectional view taken along a line BB, showing an example of the structure of a locking washer in FIG.
(C) It is sectional drawing along CC line, (d) It is a principal part expanded sectional view of a side claw.

3A and 3B are a side view and a plan view of a nut surface, respectively, showing an example of the structure of a nut in FIG. 1;

4 (a) is a side view, and FIG. 4 (b) is a plan view of a nut surface, showing a modification of FIG.

FIG. 5 is a view showing various installation examples of a conventional strainer on a filter bed plate.

[Explanation of symbols]

 DESCRIPTION OF SYMBOLS 11 Filter bed plate 12 Circular hole for strainer installation 13 Strainer 15 Slit part 16 Lower piping 20 Flange part (bottom part) 27, 40 Washer 29, 39 Nut 21, 38 Vertical groove 31 Vertical claw 33 Horizontal claw 37 Recess

Continuation of front page (72) Inventor Katsunobu Yamaguchi 11-1 Haneda Asahimachi, Ota-ku, Tokyo Inside Ebara Corporation (72) Inventor Keiichi Akagi 11-1 Haneda Asahi-cho, Ota-ku, Tokyo Inside Ebara Corporation (72) Inventor Yutaka Kodita 11-1 Asahi-cho, Haneda, Ota-ku, Tokyo F-term in Ebara Densan Co., Ltd. (Reference) 3J034 AA07 BA04 BB06 BC02 CA03 DA01 DA03

Claims (5)

[Claims] An external thread is provided on an outer peripheral surface of a cylindrical body or a cylindrical body having a flange portion, and a vertical groove is provided in the male screw portion in an axial direction. A washer with a claw is inserted into the outer peripheral surface of the cylindrical body or the cylindrical body so that the vertical claw is fitted into the vertical groove, and the opposite surface of the washer to the horizontal claw is an object to be fixed between the flange and the flange. Sandwich the plate,
A nut fastening structure, wherein a nut that is screwed to the male screw provided with a concave portion on the nut surface that engages with the lateral claw of the washer is tightened so that the lateral claw is fitted into the concave portion. . 2. A width and a depth of the vertical claw are determined so as to fit into the vertical groove, and an axial length of the vertical claw corresponds to several threads of a male screw on the cylindrical surface. The nut fixing structure according to claim 1, wherein: 3. The lateral claw has an inclined surface having elasticity,
2. The nut fastening structure according to claim 1, wherein a plurality of washers are arranged on an engagement surface with the nut. 3. 4. An N-face is provided on an engagement surface of the nut with a washer.
The nut fixing structure according to claim 3, wherein the nut has a concave-convex shape, and the inclined surface of the N-shaped concave-convex shape is in the same direction as the inclined surface of the lateral claw. 5. A filter device, wherein a water collecting and distributing device comprising a strainer or a nozzle is fixed to a filter bed plate by the nut fixing structure according to any one of claims 1 to 4.