JP2002174222A - Push nut - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide a push nut having a simple structure capable of displaying large fastening force in an extracting direction and mounting the push nut on a bolt with slight pushing force. SOLUTION: A bolt locking part 20 and a coiled mounting parts holding part 30 are continuously formed by bending a metallic wire. In the bolt locking part 20, narrow and long folded parts 21 facing each other are formed at intervals narrower than the diameter of a bolt 40. The mounting parts holding part 30 is wound in a coil diameter larger than the diameter of the bolt 40.

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a method for fixing a mounting component having a hole through which a bolt extending from a board is inserted to the board, by bending a single spring steel wire rod to form a screw at the tip of the bolt. The present invention relates to a press-fit type nut in which a locking portion locked in a groove and a mounting component holding portion wound in a coil shape are continuously formed.

[0002]

2. Description of the Related Art Conventionally, in order to mount a member to be fixed to a base material via a bolt in consideration of vibration resistance, a method of tightening with a nut via a spring washer has been generally performed. This method requires at least two parts and requires two or more steps of installation, and it is apparent that this method is not particularly suitable for use of an automatic assembling apparatus that has recently become popular. Therefore, as an alternative to such a conventional technique, a so-called “push nut” capable of one-touch mounting has been widely used. As one example, the one disclosed in Japanese Patent Application Laid-Open No. 7-117091 is known.

[0003] The details are to engage with a special bolt having a deformed screw portion in which the shaft end side is formed as a curved inclined inclined guide surface and the opposite side is formed as a retaining surface extending in the horizontal direction. The spring steel wire is bent to form a projecting part at one end, and a narrow notch part at the other end where the two end faces abut each other via a holding part large enough to fit tightly through the axis of the deformed screw part. It is disclosed as a clip-shaped simple nut coupled with a located cutout overhang. In the clip-shaped simple nut, the overhanging portion and the cutout overhanging portion are horizontal, while the holding portion is shifted in pitch so as to correspond to the thread pitch of the special bolt.

The clip-shaped simple nut is attached to the bolt by changing the holding portion so that the projecting portion and the cut-out projecting portion maintain the position where the member to be fastened presses the base member. This is completed by engaging with the retaining surface of.
As a specific operation, the holding portion is applied to the shaft end of the bolt, and the overhanging portion and the cut-out splitting overhanging portion are pressurized so that the holding portion first passes over the guide surface of the deformed screw portion and the fastening of the member to be fastened. In order to press against the surface and further obtain a tightening force between the special bolt and the special bolt, the clip-shaped simple nut is pressed firmly against the member to be fastened by applying a rotating force to the overhang and the split overhang. It is screwed until it is done.

[0005] As described above, it is possible to secure excellent tightening strength by utilizing the elastic repulsive force of the overhanging portion and the cutout overhanging portion only by applying a slight pressurization and a slight turning power.
Conversely, with respect to removal, the clip-like simple nut is only continuously applied with a turning force in the opposite direction, and at the same time, has a feature that it is hardly damaged.

[0006]

A so-called "push nut" disclosed as a clip-shaped simple nut having such a structure and features is characterized in that at least two push-fit nuts which are pressed, inserted into bolts, and then turned. The work process is required, and although the number of parts is one, installation is troublesome. However, an object of the present invention is to provide a push nut which has a simple structure and can be mounted on a bolt very easily with only one step of pushing the bolt in with a small force, and on the other hand, it is difficult to pull out once the bolt is mounted. Is what you do.

[0007]

In order to achieve the above object, according to the first aspect of the present invention, a bolt locking portion and a coil-shaped attachment component holding portion connected to the bolt locking portion are provided. In a push nut formed by bending a metal wire of the present invention, the bolt engaging portion has an elongated folded portion facing each other at an interval smaller than the diameter of the bolt, and the mounting component holding portion includes the bolt engaging portion. It is characterized by being wound around the stop portion with a coil diameter larger than the diameter of the bolt.

According to the first aspect of the present invention, it is stated that the elongated bent bolt locking portion and the coil-shaped mounting component holding portion following the bolt locking portion are manufactured by bending a single metal wire. Since it is made of a simple structure, two conventional components such as a spring washer and a nut
It has two parts. Moreover, once the bolt locking portion is pushed along the bolt onto the surface of the mounting member,
At this point, the fixing part is fixed to the screw groove of the bolt, and at the same time, the mounting part holding part is continuously wound around the bolt locking part with a coil diameter larger than the diameter of the bolt. It continues to be held between it and the surface, and thus continues to exert an elastic repulsive force on the lock. This eliminates the necessity of the turning operation for tightening after the press-fitting into the bolt as in the above-described prior art.

In the case where the material of one metal wire is steel, the engaging portion and the attachment component holding portion can be sufficiently elastically deformed. It can be done very easily with only one step of pushing the bolt into the bolt with a small force, but the bent part of the locking part is securely clamped in the bolt groove from the opposite direction, so it bites into the screw groove firmly However, it has the property that once it is mounted, it does not easily come off even if a stress in the pull-out direction acts on the mounting member. Such an extremely simple mounting operation can be performed using an automatic assembling apparatus.

[0010] The invention described in claim 2 is characterized in that the mounting component holding portion is wound with a coil diameter that decreases toward the bolt locking portion. In such a configuration, by the pushing operation at the time of mounting, the mounting component holding portion is extremely compressed in the axial direction, is sandwiched between the bolt locking portion and the mounting component, and is spirally wound on the surface of the mounting component. State. As a result, the fixed bolt locking portion and the mounting component are constantly elastically biased in the separating direction with a sufficient elastic repulsion, and an effect of reliably preventing rattling of the mounting member is produced.

The invention according to claim 3 is characterized in that the folded portion of the bolt locking portion extends in the diameter direction of the holding portion larger than the maximum coil diameter of the mounting component holding portion. In such a configuration, a detachment direction force from the attachment component acts on the coil that substantially forms the attachment component holding portion at the time of mounting, and the axial relative position with respect to the bolt locking portion is reversed. Is prevented. Further, as a result, the length of the elongated folded portion is set to be large, so that the bending when the bolt is clamped from the opposite direction increases,
The force required to push the bolt is also reduced.

[0012] The invention described in claim 4 is characterized in that the cross section of the wire has an oval shape having a smaller diameter on the inner peripheral side than on the outer peripheral side. In such a configuration, the cross section of the wire is not circular but flattened in an oval shape, and when attached to the bolt, the inner peripheral surface that is the opposing surface that contacts the bolt in the elongated folded portion of the bolt locking portion. Since the small-diameter portion is formed, the bolt is lifted upward by sliding friction with the screw thread when passing through the screw thread, and twisting occurs. This torsion reduces the bending of the folded portion and avoids an unnecessary increase in the mutual separation distance, so that the pressing force applied to the bolt locking portion at the time of mounting is smaller than that in the case of the circular cross section. At the same time, the small-diameter inner peripheral portion is deeply inserted into the thread groove when the mounting is completed. Since the peripheral portion resists due to surface contact with the thread groove surface, it becomes difficult to come off.

Hereinafter, preferred embodiments of the present invention will be described with reference to the accompanying drawings.

[0014]

FIG. 1 is a plan view of a push nut according to the present invention. FIG. 2 is a side view of the push nut shown in FIG. FIG. 3 is a side view showing a relative positional relationship immediately before the push nut is inserted into the bolt. FIG. 4 is a side view showing a state immediately after the push nut is inserted into the bolt. FIG. 5 is a side view showing a use state in which the push nut has been mounted on the bolt. FIG.
FIG. 6 is a partially enlarged cross-sectional view illustrating an engagement state between a bolt locking portion of the push nut and the bolt illustrated in FIG. 5. FIG. 7 is a side view showing a state in which a stress in the pulling direction acts on the push nut. FIG. 8 is a partially enlarged cross-sectional view showing an engagement state between the bolt locking portion of the push nut and the bolt shown in FIG.

In FIG. 1, a push nut 10 according to the present invention includes a bolt engaging portion 20 formed by bending a single metal wire and a coil-shaped mounting component holding portion coupled to the bolt engaging portion 20. 30. The bolt locking portion 20 has an elongated folded portion 21 that extends opposite to each other at an interval smaller than its diameter to be locked by the bolt 40 (see FIGS. 3 to 8). Folded part 2
1 comprises two first leg portions 22 and second leg portions 23 extending in parallel with each other and arranged in a substantially U-shape, and a semicircular first connection portion 24 connecting these two leg portions. One leg 22 has one end 25 of a single metal wire forming the entire push nut 10 according to the invention.

Further, the bolt locking portion 20 is connected to the second leg 23 outside the first leg 22 via a semicircular second connecting portion 27 connected to the second leg 23. It is connected to an adjacent and parallel third leg 26. The third leg 26 does not come into contact with the bolt 40 at all. This third leg 26 is further connected to a tangential portion 28 which is bent at right angles towards the second leg 23. The tangential portion 28 is connected to the bolt locking portion 2.
0, but also serves as the start end of the attachment holder 30 described in detail below.

The mounting part holding portion 30 starting from the tangential portion 28 is substantially constituted by a coil spring wound around the tangential portion 28 with a coil diameter larger than the diameter of the bolt 40. Therefore, this attachment part holding part 3
0 is radially separated from the bolt 40 and
0 (see FIGS. 3 and 4) to contact the surface of the bolt locking portion 2
0 has only an elastic action, and has no effect on the mounting and removing operations of the push nut 10.

Accordingly, the push nut 10 according to the present invention
In terms of its operation, the conventional two components such as the spring washer and the nut are combined into one component. Moreover, once the bolt locking portion 20 is pushed along the bolt 40 onto the surface of the mounting member 50, the bolt locking portion 20 is fixed to the screw groove 41 of the bolt 40 at that position, and at the same time, the mounting component holding portion 30 is engaged with the bolt. The bolt 4 is continuously wound around the stop portion 20 with a coil diameter larger than the diameter of the bolt.
0 and the bolt locking portion 20 in a compressed state without touching
(See FIG. 5), and continues to exert an elastic repulsive force on the bolt locking portion 20. This can be performed very easily with only one step of pushing the bolt locking portion 20 to the bolt 40 with a small force, so that the tightening after the press-fitting insertion into the bolt as in the above-described prior art is performed. This eliminates the need for a rotating operation for attaching.

As described above, in the push nut 10 according to the present invention, since the folded portion 21 of the bolt locking portion 20 is securely clamped in the thread groove 41 of the bolt 40 from the opposite direction, the push nut 10 bites into the thread groove firmly. Once mounted, it has such a property that even if the stress A in the pulling-out direction acts from the mounting member 50 via the mounting component holding portion 30 (see FIGS. 7 and 8), it is difficult to remove. Such an extremely simple mounting operation can be performed using an automatic assembling apparatus.

As shown in FIGS. 1 and 2, the push nut 10 according to the present invention includes a mounting part holding portion 30 which is connected to a tangential portion 28 of the bolt locking portion 20. It forms a coil that shrinks toward the locking part 20, but has an upper part 31 having a coil diameter of a minimum diameter continuous with the bolt locking part 20, at least one intermediate part 32 connected to the upper part, and a maximum part. And a lower portion 33 having a diameter and directly touching the surface of the mounting part 50.

In such a configuration, as is apparent from FIGS. 5 and 7, the mounting component holding portion 3 is pressed by the pushing operation on the bolt locking portion 20 at the time of mounting.
Numeral 0 is extremely compressed in the axial direction, and is sandwiched between the bolt locking portion 20 and the mounting component 50 to be in a spiral flat state on the surface of the mounting component 50 inside the lower portion 33. as a result,
The fixed bolt locking portion 20 and the mounting component 50 are constantly elastically biased in the separating direction with a sufficient elastic repulsion force, so that rattling with the mounting member 50 is reliably prevented.

In order to keep the mounting component holding portion 30 in a flat state even if a stress in the pullout direction acts, the elongated folded portion 21 of the bolt locking portion 20 has a maximum coil diameter of the mounting component holding portion 30. And extends in the diametrical direction of the mounting component holding portion 30 so as to be larger than the diameter of the lower portion 33 having the same.
By setting the length of the folded portion 21 in the length direction so as to cover the lower portion 33 having the maximum diameter of the mounting component holding portion 30, a large stress in the direction in which the mounting component is removed from the mounting component is applied to the lower portion 33. Even if it acts, the situation where the relative position in the axial direction with respect to the bolt locking portion 20 is reversed is prevented. Further, as a result, the length of the elongated folded portion 21 is set to be relatively large, so that the bending when the bolt 40 is clamped from the opposite direction is increased, and the two leg portions 22 are attached to the bolt 40.
And 23 are also slightly reduced.

Next, the process of mounting the push nut 10 according to the present invention on the bolt 40 will be described in order with reference to FIGS.

FIG. 3 shows a mounting part 5 having the bolts penetrated on a substrate 60 to which the head 43 of the bolts 40 is fixed.
0 is temporarily fixed, and further, immediately before the push nut 10 shown in FIGS. 1 and 2 according to the present invention is inserted from the free end of the bolt 40, immediately above the bolt 40. The state of being brought to the position is shown.
At this time, the bolt locking portion 20 has been brought to a horizontal position with respect to the bolt 40 extending vertically from the substrate 60.

FIG. 4 shows a state in which the push nut 10 is incompletely inserted but is inserted into the bolt 40. In this case, only the elongated folded portion 21 of the bolt locking portion 20 is attached to the bolt 40. In the screw groove 41.

FIG. 5 shows a state in which the mounting component 50 is elastically fixed to the bolt 40 by the push nut 10 according to the present invention. In other words, the final mounting state of the push nut 10 is shown. It is shown. In the push nut shown in FIG. 4, the semicircular first connecting portion 24 and the second connecting portion 27 forming both ends of the elongated folded portion 21 of the bolt locking portion 20 are pressed from above, and the bolt locking portion is pressed. 20 one and the other leg 2 opposite to each other
The lower part 3 of the mounting part holding part 30 after passing through the thread grooves 41 and the thread 42 while the
3 abuts against the surface of the mounting part 50 and
Is turned into a position where the folded-back portion 21 directly contacts the lower portion 33. After that, the push nut 10 which is in a flat state as a whole is biased so as to lift the bolt locking portion 20 upward by the elastic repulsion of the mounting component holding portion 30. As a result, the two legs 22 and 23 of the folded portion 21 are securely engaged in the thread groove 41 and assume a stable fixing position with respect to the bolt 40.

FIG. 6 is a cross-sectional view showing the sliding state of the bolt 40 and the folded portion 21 when the push nut 10 is pushed in from the state of FIG. 4 to the state of FIG. The cross section of the wire forming the folded portion 21 shown here has an oval shape in which the diameter on the inner peripheral side is smaller than that on the outer peripheral side. Of course, such an egg-shaped cross section is the push nut 1
0, not only the bolt locking part 20 but also the mounting part holding part 30. Bolt 4
At the time of attachment to the bolt 0, the inner peripheral surface of the folded portion 21 that contacts the screw groove 41 of the bolt 40 forms a small-diameter portion. To be twisted. This torsion is added to the bolt locking portion 20 at the time of mounting because the upward bending of the folded portion 21 can be reduced and an unnecessarily increased distance between the two leg portions 22 and 23 can be avoided more than necessary. The pressing force can be reduced as compared with the case of the circular cross section.

7 and 8, an external force caused by vibration or the like acts on the mounting component 50, and the mounting component 50 rises from the substrate 60 by a distance S, and as a result, the mounting component holding portion 3
0 shows a state in which the pullout direction stress A acts on the entire push nut 10 through 0. In this state, since the small-diameter inner peripheral portion of the bolt engaging portion 20 is deeply inserted into the thread groove, the inner peripheral portion is pulled out by surface contact with the side surface of the thread groove 41 as shown in FIG. Since the push nut 10 is securely resisted to the stress A, it is difficult for the push nut 10 to come off the bolt 40. At this time, the intermediate portion 32 of the attachment holder 30 is completely compressed in the axial direction from below, and the lower portion 3
3 is swirled inside. Accordingly, the push nut 10 has an appearance in which the bolt locking portion 20 is overlapped on the lower portion 33 of the mounting component holding portion 30. As described above, the overlapping condition is that the length of the folded portion 21 in the length direction is set to a length covering the lower portion 33 having the maximum diameter of the mounting component holding portion 30 as described above.

In any case, forming the push nut 10 according to the present invention with a wire having a small-diameter egg-shaped cross-sectional shape on the inner peripheral side improves the rigidity of the bolt locking piece 22 itself, and improves the rigidity of the bolt 50. The looseness that occurs between the push nut 10 and the push nut 10 is greatly reduced, and at the same time, even if the push nut 10 receives the stress A in the pull-out direction, it means that the push nut 10 does not easily come off from the bolt 40, and therefore exerts a large fastening force on the bolt Means to do.

[0030]

As described above, according to the present invention, the bolt engaging portion and the coil-shaped mounting component holding portion connected to the bolt engaging portion are formed by bending a single metal wire. In the push nut, the bolt locking portion has an elongated folded portion facing each other at an interval smaller than the diameter of the bolt, and the mounting component holding portion is connected to the bolt locking portion and has a smaller diameter than the bolt. Because it is wound with a large coil diameter, it has a simple structure and can be mounted on the bolt in only one step of pushing with a small force on the bolt, but on the other hand it is difficult to pull out once it is mounted To play.

[Brief description of the drawings]

FIG. 1 is a plan view of a push nut according to the present invention.

FIG. 2 is a side view of the push nut shown in FIG.

FIG. 3 is a side view showing a relative positional relationship immediately before a push nut is inserted into a bolt.

FIG. 4 is a side view showing a state immediately after a push nut is inserted into a bolt.

FIG. 5 is a side view showing a use state in which the push nut has been mounted on the bolt.

6 is a partially enlarged cross-sectional view showing an engagement state between a bolt locking portion of the push nut shown in FIG. 5 and a bolt.

FIG. 7 is a side view showing a state where a stress in a pull-out direction acts on a push nut.

FIG. 8 is a partially enlarged cross-sectional view showing an engagement state between a bolt locking portion and a bolt of the push nut shown in FIG. 7;

[Explanation of symbols]

 DESCRIPTION OF SYMBOLS 10 Push nut 20 Bolt locking part 21 Folding part 22 1st leg 23 2nd leg 24 1st connection part 25 End part 26 3rd leg 27 2nd connection part 28 Tangential direction part 30 Mounting part holding part 31 Upper part Part 32 middle part 33 lower part 40 bolt 41 screw groove 42 screw thread 43 bolt head 50 mounting part 60 board

Claims (4)

[Claims] 1. A push nut formed by bending a metal wire into a bolt locking portion and a coil-shaped mounting component holding portion coupled to the bolt locking portion, wherein the bolt locking portion is , Which have elongated bent portions facing each other at an interval smaller than the diameter of the bolt, and the mounting component holding portion is wound around the bolt locking portion with a coil diameter larger than the diameter of the bolt. A push nut characterized by the following. 2. The push nut according to claim 1, wherein the mounting component holding portion is wound with a coil diameter that decreases toward the bolt locking portion. 3. A bolted portion of the bolt locking portion, wherein the folded portion extends in a diameter direction of the holding portion larger than a maximum coil diameter of the mounting component holding portion.
Push nut described in. 4. The push nut according to claim 1, wherein a cross section of the wire has an oval shape having a smaller diameter on the inner circumferential side than on the outer circumferential side.