JP2002106535A - Nut case and its manufacturing method in push-on nut - Google Patents

Abstract

PROBLEM TO BE SOLVED: To manufacture a nut case with high precision integrally by cold forging with cold-forged molding machine by maintaining a push-on nut in the nut case without a large deviation. SOLUTION: The nut case is comprised of a through-hole 10 in a push-on nut having a polygonal outer periphery and a through hole at center thereof, a tapered hole part 11 arranged at longitudinally mid point thereof and expanding upwards, a small hole part 12 communicating with a lower part of the tapered hole part 11 and having a hole with a same diameter as an inner diameter at lower side of the tapered hole part 11 and a large hole part 14 communicating with an upper part of the tapered hole part 11 through a step part 13 and having a hole with a greater diameter than an inside diameter at an upper side of the tapered hole part 11, in which a plurality of sliding guide ribs 15 expanding in the central axis direction and protruding inwards the tapered part 11 are circumferentially arranged at same intervals and also a flange part 16 is integrally formed at an outer perimeter at the small hole part in the case.

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention
In the above-mentioned tapered hole portion of the nut case provided with a through hole having a tapered hole portion whose upper part is expanded at the center, a divided nut segment is provided by being constantly pressed downward by a pressing spring, and a bolt is provided between the segments. The present invention relates to a nut case for a push-type nut that is inserted and a method of manufacturing the same.

[0002]

2. Description of the Related Art Conventionally, as a push-type nut of this type,
For example, it is disclosed in Japanese Utility Model Publication No. 58-40329. As shown in FIG. 11, the push-in type nut has a tapered hole 41 extending upward and downward in a nut case 40 and a nut segment 42 divided in the tapered hole 41. The pressure spring 43 is always pressed downward to provide a bolt 44 between the segments 42. As for the shape of the nut case 40, a tapered hole 41 having a polygonal outer surface, an upper portion expanding inside and an opening at the upper and lower ends is provided inside the nut case 40, and a lower portion of the inner surface of the taper hole 41 is formed in an axial direction. And three sliding guide ribs 45 extending inward and projecting inward are provided at equal intervals in the circumferential direction. And
The nut case 40 is manufactured by die casting.

[0003]

However, in the above-described conventional nut case 40, the tapered hole 41 is tapered from the lower end to the upper end of the case 40. When the pressing spring 43 is inserted, a large shift in the radial direction of the pressing spring 43 with respect to the tapered hole 41 is likely to occur on the upper side, so that when the pressing nut is inserted into the bolt 44, the bolt 44 and the pressing spring 43 There was a problem that a problem such as interference occurred. In addition, since the nut case 40 is formed by die-casting, not only the molding accuracy is low, but also the productivity is poor.

Accordingly, the present invention is to improve the productivity and accuracy by enabling the case to be manufactured consistently with high precision by forging with a forging machine while holding the pressing spring in the nut case without significant displacement. And a method of manufacturing the same.

[0005]

SUMMARY OF THE INVENTION In order to solve the above-mentioned problems, an invention according to claim 1 of the present application is directed to a nut having a polygonal outer periphery and a through-hole having a tapered hole whose center portion is expanded upward. A nut case in a push-type nut in which a divided nut segment is provided by being constantly pressed downward by a pressing spring in the tapered hole portion of the case, and a bolt is inserted between the segments. A tapered hole disposed at an intermediate portion in a longitudinal direction thereof, an upper portion of which is expanded, a small-diameter hole communicating with a lower portion of the tapered hole, and having the same diameter as a lower inner diameter of the tapered hole; The upper portion of the hole portion communicates with the upper portion of the tapered hole portion through a stepped portion, and has a larger diameter than the inner diameter of the upper portion of the tapered hole portion. The sliding guide rib protruding toward To keep regular intervals with provided a plurality flange portion on the outer peripheral edge of the small-diameter hole portion side of the case is characterized in that it is formed integrally.

According to a second aspect of the present invention, there is provided a method of manufacturing a nut case, wherein the outer periphery is polygonal and the center of the nut case is provided with a through-hole having a tapered hole which is opened upward. A method of manufacturing a nut case in a push-type nut in which divided nut segments are always provided by being pressed downward by a pressing spring, and a bolt is inserted between the segments. And forming by a punch to form a primary molded product having a polygonal outer periphery and a concave portion above the center,
A molding process is performed on the primary molded product by a die and a punch in the next step, and a tapered hole communicating with the concave portion and having an expanded upper portion is formed at a lower central portion of the concave portion, and an inner surface is formed from the inner surface of the tapered hole portion. A secondary molded product having a plurality of sliding guide ribs protruding in the direction is formed. Thereafter, the secondary molded product is rotated by 180 degrees, and then subjected to molding by a die and a punch in the next step. A tertiary molded product having a flange at the lower outer peripheral end of the next molded product is formed, and further molded by a die and a punch in the next process, and communicates with the tapered hole at the lower central portion of the tapered hole. And a final molded product having a small-diameter hole having the same diameter as the lower inner diameter and opening on the lower surface.

[0007] By using the above means, the pressing spring of the nut segment can be held in the nut case without a large deviation, and the nut case is manufactured consistently with high precision by forging with a multi-stage forging machine. It is possible to improve the productivity and to reduce the cost.

[0008]

Embodiments of the present invention will be described below with reference to the drawings. 1 and 2 show a push-type nut using the nut case of the present invention. Numeral 1 is a nut case having a hexagonal outer periphery, and a through hole 10 is formed at the center of the case 1 so as to penetrate in the length direction thereof. The through hole 10 is located at an intermediate portion thereof and is open to the upper side. The through hole 10 is connected to a large diameter side upper portion of the tapered hole portion 11 via a step portion 13. A radial hole portion 14,
It is located at the lower part and communicates with the lower part of the small diameter of the tapered hole part 11,
In addition, the tapered hole portion 11 has a small diameter hole portion 12 having the same diameter as the small diameter side inner diameter and serving as a bolt insertion hole to be described later. On the inner surface of the tapered hole 11, three sliding guide ribs 15 extending in the axial direction and projecting inward are provided at equal intervals in the circumferential direction. A flange 16 is integrally formed on the outer periphery. Further, a caulking stopping step 17 is formed on the opening end side of the large diameter hole 14. In FIG. 1, reference numeral 18 denotes a chamfer for guiding. In the embodiment described above, the sliding guide rib 1
Although the description has been made of the case where three 5 are used, the number is not limited to three, but may be plural such as four or five.

The following members are incorporated in the nut case 1 formed as described above to form a push-in type nut A as shown in FIG. First, each of the guide ribs 1
Nut segments 2a... 2a obtained by dividing the nut body 2 into four parts are provided between the nut segments 5 and 15 so as to be vertically slidable. Next, a washer 3 is commonly brought into contact with the upper portion of the nut segments 2a... 2a, and a through hole 5a is provided with a pressing spring 4 for urging the washer 3 toward the step 13 side. The cover 5 is caulked to the caulking step 17.
Thus, each nut segment 2a.
Thereby, the tapered hole portion 11 is always pressed toward the narrow side. In this case, the pressing spring 4 has a structure in which movement in the radial direction is suppressed by the inner surface of the large-diameter hole portion 14 having the same diameter. In FIG. 1, 6 is a bolt, 7
Indicates a member to be tightened.

Next, the operation when the push-in type nut A constructed as described above is used will be described with reference to FIG.

The small-diameter hole portion 12 of the push-in nut 2 is aligned with the tip of a bolt 15 inserted through the through-hole of the member to be tightened, and is inserted into a screw hole 2b formed by four nut segments 2a. The nut case 1 is pushed down so that the bolt 6 is inserted. Then, the thread 6a of the bolt 6
2a are engaged with the screw holes 2b of the nut segments 2a... 2a so that the four nut segments 2a. The inner diameter of the bolt 2b is gradually expanded.
Can be inserted while sliding through the screw hole 2a. Therefore, the nut segments 2 a... 2 a are rattled against the pressing spring 4 and are inserted beyond the thread 6 a of the bolt 6. In this manner, the push-in nut A can be inserted into the bolt 6 simply by pressing without rotating. Then, until the lower surface of the push-in nut A contacts the member 7 to be tightened, the nut case 1 is
, The case 1 can be tightened by rotating the case 1 in the tightening direction about two or three times.

As described above, according to the nut case 1 of the present invention, the pressing spring 4 is accommodated and held in the large-diameter hole portion 14 having the same diameter, so that the pressing spring 4 is not largely displaced in the radial direction. Accordingly, it is possible to prevent a trouble that the bolt 7 and the pressing spring 4 interfere with each other when the push-in nut A is inserted into the bolt 7. In addition, the nut case 1 can be consistently manufactured with high precision by forging by a multi-stage forging machine, and productivity and accuracy can be improved.

Next, a method for manufacturing a nut case in the push-in type nut according to the present invention will be described.

First, a cylindrical blank 1a cut to a predetermined length as shown in FIG. 5 is formed by a die 21 and a punch 22 of a press forming station S1 in a multi-stage press forming machine shown in FIG. 6 has a hexagonal outer periphery, and a step 1 for caulking is provided at the center of one end in the longitudinal direction.
7 and a large-diameter concave portion 14 to form a primary molded product 1b in which the outer peripheral portion of the other end is narrowed.

Next, the primary molding 1b is formed by the die 23 and the punch 24 in the next step of the forging station S2, and the lower central portion of the large-diameter concave portion 14 as shown in FIG. Molded article 1 having a tapered hole 11 whose upper part expands and three sliding guide ribs 15... 15 protruding from the inner surface of the tapered hole 11.
Form c.

Thereafter, the secondary molded product 1c is rotated by 180 degrees by a material direction changing device (not shown), and then subjected to molding by the die 25 and the punch 26 of the next forging station S3. A tertiary molded product 1d having a flange 16 at the lower outer peripheral end of the secondary molded product 1c as shown and having a tapered recess 18 for guiding at the center of the lower surface is formed.

Further, a forming process is performed by a die 27 and a punch 28 in the next step of the forging station S4, and a small-diameter hole 12 is formed in the lower central portion of the tapered hole 11 as shown in FIG.
Is formed over the center of the tapered recess 18 to form a final molded product.

The forging stations S1 to S
The blank and each molded product molded in 4 are discharged out of each die by the reciprocating operation of the knockout pins 29, 30 and the strippers 32, 33 as the punches are retracted, and the discharged molded products and The transfer of the columnar blank between the forging stations S1 to S4 is sequentially performed from an upstream forging station to a downstream forging station by a known material transfer chuck device and a material direction changing device, not shown.

As described above, the nut case 1 can be manufactured consistently by forging with a multi-stage forging machine. Thus, the nut case 1 with high precision can be manufactured, and mass production is possible, productivity can be improved, and the nut case 1 can be provided at low cost.

[0020]

As described above, according to the nut case of the present invention, the pressing spring can be held in the large-diameter hole portion having the same diameter without a large displacement, and when the push-type nut is inserted into the bolt, the bolt and the bolt can be held together. Problems such as interference with the pressing spring can be prevented, and the nut case can be consistently manufactured with high precision by forging by a forging machine, thereby improving productivity and accuracy.

Further, according to the method of manufacturing a nut case of the present invention, the case can be manufactured consistently by forging with a multi-stage forging machine. Thus, a high-precision nut case can be manufactured, mass production can be performed, productivity can be improved, and the nut case can be provided at low cost.

[Brief description of the drawings]

FIG. 1 is a longitudinal sectional view of a nut case according to the present invention.

FIG. 2 is a plan view of the nut case.

FIG. 3 is a longitudinal sectional view of a push-type nut to which the nut case is applied.

FIG. 4 is an explanatory view showing a use state of a push-type nut.

FIG. 5 is a front view of a columnar blank used when manufacturing by the manufacturing method according to the present invention.

FIG. 6 is a plan view of a primary molded product manufactured at a press forming station S1 of the manufacturing method.

FIG. 7 is a plan view of a secondary molded product manufactured at the heading station S2 of the manufacturing method.

FIG. 8 is a plan view of a tertiary molded product manufactured at the forging station S3 of the manufacturing method.

FIG. 9 is a plan view of a final molded product manufactured at a press forming station S4 according to the manufacturing method.

FIG. 10 is an enlarged cross-sectional view of a main part showing a punching state at each of the forging stations in the multi-stage forging machine.

FIG. 11 is a conventional explanatory diagram.

[Explanation of symbols]

 DESCRIPTION OF SYMBOLS 1 Nut case 2 Nut body 4 Press spring 10 Through hole 11 Tapered hole 12 Small diameter hole 13 Step 14 Large diameter hole 15 Sliding guide rib 16 Flange A Push-in nut

Claims (2)

[Claims] 1. A nut segment having a polygonal outer periphery and a central portion having a through hole having a tapered hole portion which is opened upward at the center portion. A nut case for a push-type nut which is provided by being pressed to allow a bolt to be inserted between the segments, wherein the through hole has a tapered hole portion which is disposed at an intermediate portion in the length direction and which has an upwardly expanded upper portion. A small-diameter hole portion communicating with a lower portion of the tapered hole portion and having the same diameter as the inner diameter on the lower side of the tapered hole portion, and communicating with an upper portion of the tapered hole portion via a step portion, and on an upper side of the tapered hole portion. On the inner surface of the tapered hole, a plurality of sliding guide ribs extending in the center axis direction and projecting inward are provided at equal intervals in the circumferential direction, while having a large-diameter hole larger than the inner diameter. And small in the above case. A nut case for a push-in type nut, characterized in that a flange portion is integrally formed at an outer peripheral end on a diameter hole portion side. 2. A divided nut segment is always downwardly pressed by a pressing spring in the above-mentioned tapered hole portion of a nut case having a through hole having a polygonal outer periphery and a tapered hole portion which is opened upward at the center. A method for manufacturing a nut case in a push-type nut that is provided by pressing and inserting a bolt between the segments.First, a cylindrical blank is formed by a die and a punch, and the outer periphery is polygonal, Forming a primary molded product having a concave portion above the central portion, and then subjecting the primary molded product to molding by a die and a punch in the next step, and communicating with the concave portion and the upper portion at the lower central portion of the concave portion. A secondary molded product having an expanded tapered hole and a plurality of sliding guide ribs protruding inward from the inner surface of the tapered hole was formed, and then the secondary molded product was rotated by 180 degrees. On the next process A molding process is performed by using a bunch and a punch to form a tertiary molded product having a flange at the lower outer peripheral end of the secondary molded product. A nut in a push-type nut, wherein a final molded product having a small-diameter hole portion communicating with the tapered hole portion and having the same diameter as the lower inner diameter thereof and opening on the lower surface is formed in a lower central portion. Case manufacturing method.