JP2001099119A - Screwing unit of female screw member and male screw member - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide a screwing unit capable of smoothly carrying out a screw operation by correcting displacement and inclination even if the displacement and inclination are generated between a nut and a bolt when a screwing operation of the nut and the bolt is started. SOLUTION: An annular step surface (a female screw side screwing surface) for correcting a screw operation is formed outward a nut on an inner circumferential surface which is formed in the vicinity of an opening end of a screwing side of the nut along a loop, on the basis of an elliptical loop (an annular line) where a flat surface inclined from a flat surface perpendicular to a center line of the nut and an inner circumferential surface of the nut are crossed with each other. An inner diameter (an axis right angled inner diameter) in the direction perpendicular to the center line of the nut in the step surface inner circumferential edge, is formed smaller than a trough diameter of a female screw of the nut, the female screw is formed from the step surface. A male side screwing surface is formed on an end part of the screwing side of a bolt along a loop on the basis of an elliptical loop (an annular line) where a flat surface inclined from a flat surface perpendicular to the center line of a bolt and an outer peripheral surface of the bolt are crossed with each other. An outer diameter (an axis right angled outer diameter) in the direction perpendicular to the center line of the bolt in the outer peripheral edge of the screwing surface is formed larger than a trough diameter of the male screw of the bolt, and the male screw is formed from the screwing surface.

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention typically relates to a screwing unit for a female screw member and a female screw member such as a nut and a bolt, and more particularly to a screwing start (screw-in) between the female screw member and the male screw member. Related to a technology that can be performed smoothly.

[0002]

2. Description of the Related Art Conventionally, when screwing a nut and a bolt together with the nut or the bolt in a state where the bolt or the nut is inclined with respect to the nut, the screw cannot be engaged with each other, and if the rotation operation is forcibly continued. , Seizure occurs,
The screw may be crushed.

[0003]

SUMMARY OF THE INVENTION An object of the present invention is to correct even if there is a relative inclination or misalignment between shafts in a mutually screwed object such as a nut and a bolt, and correct the screw. An object of the present invention is to provide a screwing unit for facilitating the connection.

[0004]

SUMMARY OF THE INVENTION The present invention is a screwing unit of a female screw member and a male screw member screwed together. The female screw member is based on an elliptical loop (annular line) in which a plane inclined with respect to a plane perpendicular to the center line of the female screw member and the inner peripheral surface of the female screw member intersect.
Substantially along this loop, on the inner peripheral surface near the opening end of the female screw member on the screw side, an annular and stepped female screw side for screw correction so as to face outward of the female screw member. A threaded front is formed. Further, an inner diameter (an inner diameter at right angles to the axis) of the inner peripheral edge of the female screw side screwing correction front surface in a direction perpendicular to the center line of the female screw member is made smaller than a root diameter of the female screw of the female screw member. A female screw is formed from the screw-side screw-in correction surface, while the male screw member has an elliptical loop in which a plane inclined with respect to a plane perpendicular to a center line of the male screw member and an outer peripheral surface of the male screw member intersect. With reference to the annular line), a threaded screwing correction front surface is formed substantially at the end of the threaded side of the male screw member along this loop. And the outer peripheral edge of the screw-in correction front face,
The outer diameter (outer diameter perpendicular to the axis) in a direction perpendicular to the center line of the male screw member is set to be larger than the root diameter of the male screw of the male screw member, and the male screw is formed from the screwing front. Then, the screwing is started through a sliding contact between the female screw side screw-correction front surface of the female screw member and the male screw member screw-correction front surface.

[0005] In this manner, the annular and stepped surface of the female screw side screw-in correction front surface is formed along an elliptical loop inclined with respect to the axis of the female screw member (nut or the like). ) Is formed along an elliptical loop that is inclined with respect to the axis of め), and at the time of screwing, the female screw side and the male screw side straightening face slide with each other based on the relative rotation of both. When the nut and the bolt make one rotation relative to each other, for example, when the nut or the bolt starts to screw together with the bolt or the nut, even if the axes of the nut and the bolt are inclined, the above-mentioned internal thread is formed. The side and male screw side screw-in straightening faces (including their inner peripheral edges) act as if they were swash plate cams or inclined cams, and generate a so-called moment of force so as to eliminate the inclination between the nut and the bolt. . Therefore, even if the nut and bolt shafts are inclined to some extent, this inclination is corrected, and a smooth meshing state is easily obtained.

In addition to the above-described structure of the female screw member, a cylindrical shape having no female screw formed on the opening end side of the female screw member from the annular and stepped female screw side screwing correction front surface. The guide surface is formed concentrically with the center line of the female screw member, and the cylindrical guide surface is larger than the inner diameter at right angles to the axis of the inner peripheral edge of the annular and stepped female screw side screwing correction front surface. It can be configured to have an inner diameter slightly larger than the root diameter of the internal thread of the internal thread member and to be connected to the annular stepped surface.

As described above, in addition to the stepped surface female screw side screwing correction front surface such as the swash plate cam or the inclination cam, a cylindrical guide surface is formed in front of the screwing correction front surface. The inclination and misalignment of the axes of nuts and bolts are corrected to some extent in advance by the cylindrical guide surface, and furthermore, by the so-called cam action of the above-mentioned stepped surface-shaped female screw side screwing correction front (stepped portion). Mainly, the inclination between the shafts is corrected, and it becomes easy to generate a screwable state. From the viewpoint of the guide, it is conceivable that only the cylindrical guide surface is formed alone on the female screw member, but it is possible to form the cylindrical guide surface and the stepped surface female screw side screw-in correction front in two steps. By adopting the structure, the width (length) of the cylindrical guide surface can be reduced as compared with the case of the single formation, and the screw length affecting the fastening force can be increased. The cylindrical guide surface also contributes to providing a fulcrum for a kind of cam action (moment of force) by the stepped surface when a bolt or the like enters obliquely.

Further, a tapered guide surface extending outward in the axial direction of the nut or the like is formed concentrically with the internal thread of the nut or the like at the open end of the female screw member such as the nut on the screw side. The tapered guide surface and the stepped surface female screw side screw-in correction surface are formed so that the stepped surface-shaped female screw side screw-in correction surface is formed from the small diameter side end of the tapered guide surface. With the combination, the positional deviation and inclination between the nut and the bolt can be corrected. Alternatively, the cylindrical guide surface is formed from the small diameter side end of the tapered guide surface, and the stepped surface female screw side screw-in correction front is formed from the inner end of the cylindrical guide surface. In this manner, the tapered guide surface, the cylindrical guide surface, and the above-mentioned stepped surface female screw side screw-in correction front face from the screw-in side end of the female screw member are, so to speak, 3.
It is also possible to form a connection with the step, and to correct the engagement at the start of the screwing of the nut and the bolt by the synergistic action of these.

In addition to the above-described structure of the male screw member, inside the annular male screw-side screwing correction front surface, a center line of the male screw member is concentric with the screw-side end surface of the male screw member such as a bolt. A protruding cylindrical guide protrusion is formed, and the outer diameter of the guide protrusion can be configured to be slightly smaller than the root diameter of the external thread of the male screw member.

As described above, in addition to the male screw-side screw-correcting front surface such as the swash plate cam or the tilt cam, the guide convex portion is formed in front of (preceding side of) the screw-correcting front surface. The convexity corrects the inclination and misalignment of the axes of the male screw member and nut etc. to some extent, and further corrects the inclination of the axes mainly by the so-called cam action of the annular screwing front, so that the screw can be screwed. It is easy to occur. From the viewpoint of the guide, it is conceivable to form only the columnar guide convex portion alone, but by forming a two-stage structure of the guide convex portion and the annular screw-in correction front surface, it is possible to form the single guide convex portion. The length (projection amount) of the guide projection may be shorter than that of the guide projection, and the screw length affecting the fastening force may be increased. Also,
When the nut or the like enters obliquely, the guide projection also contributes to providing a fulcrum of a kind of cam action (moment of force) by the above-described annular male screw side screwing correction front surface.

[0011]

DESCRIPTION OF THE PREFERRED EMBODIMENTS An embodiment of the present invention will be described below with reference to an embodiment shown in the drawings (a unit for screwing a nut and a bolt). In addition, among the screwing units, the nut will be described first, and then the bolt will be described. 1 to 3 show a nut 1 which is one member of one embodiment of the present invention. The nut 1 includes a tool engaging portion such as a hexagonal portion 4 and a flange 2 formed at a screw-side end thereof. A stepped surface 5 which obliquely crosses the center line O of the female screw member is formed as a female screw-side screwing correction front surface at the screw-side end. The concept of the stepped surface 5 will be described with reference to FIGS.

Now, the center line O of the nut N shown in FIGS.
P is a plane inclined with respect to a plane perpendicular to. Then, an elliptical loop (annular line) where the plane P intersects with the inner peripheral surface of the nut N can be defined as indicated by R in FIG. As shown conceptually in FIG. 7 substantially along the loop R, the screw 1 straightens on the inner peripheral surface near the opening end on the screwing side of the nut 1 (N) so as to face outward of the nut 1. An annular stepped surface (stepped portion) 5 is formed. The inner diameter of the inner peripheral edge of the stepped surface 5 (female screw side straightening front) in the direction perpendicular to the center line O of the female screw member (shaft perpendicular inner diameter d) is:
Nut 1 is smaller than root diameter D of female screw 3 and female screw 3
Is equal to or substantially equal to the ridge diameter (inner diameter of the internal thread).

The degree of inclination (in terms of angle, θ) of the elliptical loop R with respect to the center line O of the nut, which is a reference for forming the stepped surface 5, is closest to the opening end of the nut of the loop R. When converted into a difference (distance) L in the nut axis direction between the point and the farthest point, the distance is set to be, for example, 2 pitches or less of the internal thread of the nut 1. In addition,
As the lower limit, for example, about 0.3 pitch can be exemplified,
In that case, the difference L indicating the degree of the inclination is in the range of 0.3 to 2 pitches. Among them, for example, 0.8 to 1.2
It can be said that a pitch of about one pitch is generally desirable.

If L, which indicates the degree of inclination of the elliptical loop R, is 0.3 pitch or less, the effect of screwing correction cannot be sufficiently obtained as described later, and L becomes 2 pitches or more. Then, when forming the stepped surface 5 with a cold forging punch or the like (cold forging die), the stress (bending force) in the direction perpendicular to the axis increases, and the number of female threads less than 360 degrees in the female thread increases. Therefore, the above-mentioned range is preferable because it has an unfavorable effect on the fastening force. Further, if the angle θ is directly defined, θ can be, for example, in the range of about 2 to 15 °, and especially about 5 to 10 ° (for example, about 8 °). The reason for the numerical range is as described above.

As shown in FIG. 7, the stepped surface 5 is formed on the basis of the above-mentioned inclined elliptical loop R.
Further, the stepped surface 5 itself is formed to be inclined at a predetermined angle α with respect to a plane P ′ perpendicular to the axis of the nut 1 so as to taper toward the opening side of the nut 1. This inclination angle α is
For example, when the flank angle of the internal thread of the nut 1 is F, the flank angle can be set to about 0.5F to 1.5F, and the flank angle F and the inclination angle α of the stepped surface 5 are almost equal. (Set the inclination angle α to about the flank angle F). If the inclination angle α is too large, the screwing correction function is likely to be insufficient. Conversely, if the inclination angle α is too small, the inner peripheral edge of the stepped surface 5 becomes a so-called pin angle or close to this so that the ends of the bolts and the like inward. The above range is preferable because the guiding effect is reduced. Reference numeral 8 denotes a rising wall following the stepped surface 5 (which defines the depth of the stepped surface 5 and can be regarded as a part of the stepped portion).

The nut N in FIG. 7 shows the concept of the stepped surface 5, and FIGS. 1 to 3 are close to actual products.
As is clear from FIG. 3, the nut 1 has a cylindrical guide surface (hereinafter referred to as a cylindrical guide surface) 6 on which an internal thread is not formed at an opening end of the nut from the annular stepped surface 5. The cylindrical guide surface 6 is formed concentrically with the center line O of the inner surface of the annular stepped surface 5 and has an inner diameter perpendicular to the axis (FIG. 7).
D), and has an inner diameter D ′ slightly larger than the root diameter D of the female screw of the female screw member, and is connected to the annular stepped surface 5. Further, a tapered guide surface (hereinafter, referred to as an “outer end”) that spreads outward in the axial direction of the nut 1 is provided at an open end of the cylindrical guide surface 6 (an open end on the female screw member screwing side).
A tapered guide surface 7 is formed, and the small-diameter end of the tapered guide surface 7 is connected to the cylindrical guide surface 6.

The width L1 of the cylindrical guide surface 6 in the axial direction of the female screw member is 0.5 to 2 of the female screw of the nut 1.
In this example, for example, 1
It is set to the pitch. The distance L2 between the open end of the cylindrical guide surface 6 and the deepest portion of the stepped surface 5 is set to, for example, 1 to 3.5 pitches. For example, in this example, the distance L2 is formed to be about 2 pitches. The taper angle β of the tapered guide surface 7 is, for example, about 20 to 80 °, especially about 30 to 70 °, and in this example, for example, 40 to 60 °.
° is set in the range. The depth L3 of the tapered guide surface 7 (the width of the female screw member in the axial direction) is set to, for example, about 0.2 to 2 pitches of the female thread of the nut 1, and for example, 0.2 to 1 pitch. In the example, the pitch is about 0.5 pitch.

As described above, the stepped surface 5, the cylindrical guide surface 6, and the tapered guide surface 7 are provided in series and continuously in a three-stage structure toward the open end of the female screw member. The surface 7 serves to introduce a male screw member such as a bolt, and the cylindrical guide surface 6 corrects the positional deviation and inclination between the female screw member and the bolt to some extent, and furthermore, the stepped surface 5 tilts both like a rotating cam. Act in the direction to correct. Therefore, the cylindrical guide surface 6 may be as short as, for example, about one pitch as described above, and the screw length can be increased while improving the correcting effect.

Next, a bolt will be described as a male screw member for the nut as described above. FIG. 8 conceptually shows a bolt 41 which is the other member of the embodiment of the present invention. The bolt 41 has a head 42 such as a hexagonal part (tool engaging part).
And a leg 43 on which a male screw 44 is formed.
An annular and stepped surface male screw side screwing correction front surface (stepped surface) 45 is formed at the distal end of 3, and a guide convex portion 46 is formed so as to protrude further from the stepped surface 45. .

As conceptually shown in FIG. 9, a bolt P4 and a plane P 'inclined with respect to a plane perpendicular to the center line of the bolt 41 are shown.
1 is an elliptical loop (annular line) R 'intersecting with the outer peripheral surface
An annular external thread side screw-in correction front surface 45 is formed substantially along the loop R ′ with reference to FIG. The male screw side screw-in correction front surface 45 can be regarded as an annular stepped surface or shoulder surface in relation to the guide projection 46. The outer diameter (the outer diameter at right angles to the axis) D ″ (see also FIG. 10) of the outer peripheral edge of the screw-in correction front surface 45 in a direction perpendicular to the center line of the bolt 41 is the bolt 41.
A male screw 44 is formed from the screw-in correction front surface 45 so as to be larger than the root diameter d 'of the male screw and to be equal to or substantially equal to the mountain diameter (outer diameter) of the male screw.

The degree of the inclination θ ′ of the elliptical loop R ′ as a reference for forming the screw-in correction surface 45 with respect to a plane perpendicular to the center line O of the male screw member (plane perpendicular to the axis) is determined by the loop R 'The difference (distance) a in the axial direction of the male screw member between the point closest to the screwed end of the male screw member and the farthest point is the bolt 4
It can be set so as to be equal to or less than two pitches of one male screw 44. As for the lower limit, the above-mentioned disparity a
Can be, for example, 0.3 pitch or more of the male screw 44. Further, the inclination angle θ ′ of the screw-in correction front surface 45 can be set to, for example, 3 to 15 °, especially 5 to 10 °, for example, about 8 °. If the inclination angle θ ′ or the difference a is too small, the effect of correcting the inclination between the screwing objects described below is not sufficiently obtained, and if the inclination angle is too large, the screw thread is divided at the screw-in correction front surface 45. From the viewpoint that the screw length becomes shorter and the screw length becomes shorter, and the lateral load (bending force) becomes excessive when forming the screw-in correction front surface 45 of the bolt 41 with a cold forging die. It is desirable that θ ′ (the difference a) be set in the above range.

Further, the annular screw-in correction front surface 45 formed along the inclined elliptical loop as described above further has the annular screw-in correction surface 45 itself in the plane perpendicular to the axis Q ′ of the bolt 41. On the other hand, it is formed to be inclined by a predetermined angle α ′ so as to taper toward the threaded end side of the male screw member. When the flank angle of the external thread 44 is F, for example, the inclination angle α ′ is preferably, for example, about 0.3F to 2F, especially about 0.5F to 1.5F, and particularly the flank angle of the external thread 44. It is recommended to be about F. If the inclination angle α ′ of the screwed front 45 is too large,
The correction function by the stepped surface 45 is easily reduced, and if the correction function is too small (for example, α ′ is 0), a problem such as the strength of the outer peripheral edge occurs.

The guide projection 46 on the distal end side from the male screw side straightening front surface 45 has a columnar shape that is cut off obliquely at the aforementioned screwing straightening front surface 45, and protrudes concentrically in the axial direction of the bolt 41. The tip surface of the guide projection 46 is perpendicular to the center line O of the bolt 41. The outer diameter φ of the guide protrusion 6 is slightly smaller than the root diameter d ′ of the male screw 44 of the bolt 41, and the protrusion b of the guide protrusion 46 in the axial direction of the screw member is equal to that of the male screw of the bolt 41. The pitch may be equivalent to about 0.5 to 2 pitches, or may be 0.7 to 1.2 pitches (for example, about 1 pitch).

The guide convex portion 46 has a function of correcting the positional deviation and inclination at the start of screwing with a female screw member such as a nut to some extent prior to the screw-in correction front surface 45. If the projecting dimension b of 46 is too large, the bolt 41
Since the screw length becomes shorter than the total length of the screwdriver, and if the screw length is too small, it is difficult to obtain a function of performing correction (guide) prior to the screw-in correction front surface 45. Therefore, it is desirable to set the screw length within the above range.

FIG. 11 conceptually shows the screwing correction action by the stepped surface 5 of the nut 1 (female screw side straightening front) and the stepped surface 45 of the bolt 41 (male screw side straightening front). It is shown. For example, as shown in FIG.
, The nut 1 bites obliquely to the bolt 41, or the nut 1 and the bolt 41 both bite obliquely (in short, the nut 1 and the bolt 41). As shown in (b), when the nut 1 rotates with respect to the bolt 41 (or when the bolt 41 rotates with respect to the nut 1, or when both rotate in opposite directions, as shown in FIG. When the nut 1 and the bolt 41 rotate relatively), the nut 1
The portion shallower than the deep portion of the stepped surface 5 (including the inner peripheral edge of the stepped surface 5) becomes the portion higher than the lower portion of the stepped surface 45 of the bolt 41 (including the outer peripheral edge of the stepped surface 45). Sliding contact, the moment of the force (including the rotational moment) in the direction of raising the bolt 41 or the nut 1 (the direction of trying to make each axis of the nut 1 and the bolt 45 coaxial) with the contact portion acting as the point of application of the force acts. I do. As a result, as shown in (c), a state in which the axes of the nut 1 and the bolt 45 coincide with each other is likely to occur, and a biting defect is less likely to occur when the two are screwed (start of screwing).

FIG. 12 shows this state more substantively. Even if the bolt 41 or the nut 1 is inclined at an angle γ with respect to the axis of the other party (the nut 1 or the bolt 41), the angle γ is eliminated. (To raise the bolt 41 or the nut 1). It should be noted that the relative inclination angle γ of the bolt 41 with respect to the nut 1 is, for example, normally in the range of about 2 ° to 3 °, but generally becomes less than 5 ° (about 8 °) in general. -Although the screwing of the nut is difficult, according to the screwing unit of the nut 1 and the bolt 41 of the present invention, this can be easily corrected even if the inclination is, for example, about 8 °. Also, due to the synergistic effect of the screw-in correction fronts 5 and 45 of both the nut 1 and the bolt 41, the heights L (FIG. 7) and a (FIG. 8) of inclination of the screw-in correction fronts 5 and 45 are provided. Is obtained, a desired amount of inclination is allocated to the nut 1 and the bolt 41, and as a result, each amount of inclination (height L, a) is reduced (for example, only one of the nut and the bolt). It is also possible to make the inclinations, for example, about ２, so that the inclination and the like can be corrected while keeping the screw length of the nut 1 and the bolt 41 long.

As shown in FIG. 13A, the nut 11 shown in FIG. 13 has a stepped surface 5 (female screw side straightening front).
, But the tapered guide surface 7 is omitted, and (b) is an overall sectional view,
(C) is a front view.

The nut 12 shown in FIG.
This is a type having only the cylindrical guide surface 6 and the tapered guide surface 7, and (a) is an enlarged view, (b) is an overall sectional view, and (c) is a front view. If the cylindrical guide surface 6 is not provided at the opening end of the screwing side like the nut 12 shown in FIG. 14 and only the stepped surface 5 is used, the entire screw length can be increased. If the stepped surface 5 and the cylindrical guide surface 6 are combined like a nut 11 shown in the drawing, a correcting action can be expected in two stages. The cylindrical guide surface 6
(The same applies to the cylindrical guide surface 6 in FIG. 3), for example, as shown in FIGS. 11 and 12, the stepped surface 5 of the nut 1
When a moment of force in the direction of correcting the inclination of the two is applied in cooperation with the step surface 45 of the first step, the above-mentioned state is performed in a state where the tip of the bolt is in contact with the cylindrical guide surface 6 shown in FIGS. , The cylindrical guide surface 6 can be expected to function as a fulcrum of force.

FIGS. 15 to 17 show a cap nut (hub nut) 21 which is a female screw member according to another embodiment of the present invention. As shown in the front view of FIG. 15 and the cross-sectional view of FIG. 16, the hub nut 21 has a tool engaging portion such as a hexagonal portion 20 and a thread forming portion or a hole fitting portion such as a cylindrical portion 23 on the opposite side. And the flange 22 located between the two form an integral tubular shape. The female screw 3 is formed beyond the cylindrical portion 23 and the flange 22, the inside of the hexagonal portion 20 is a space into which a bolt enters, and a cap 24 is integrated with the opening of the hexagonal portion 20 by welding or the like. The opening is closed to form a cap nut.

At the opening end of the cylindrical portion 23 (thread forming portion) on the screwing side, a stepped surface (female screw side screwing correction front) 25, a cylindrical guide surface 26 and a tapered guide surface 27 are connected in the axial direction. It is formed as follows. FIG. 17 is an enlarged view thereof. The stepped surface 25, the cylindrical guide surface 26, and the tapered guide surface 27 are substantially the same as the stepped surface 5, the cylindrical guide surface 6, and the tapered guide surface 7 shown in FIG. Detailed description is omitted.

The hub nut 21 is fastened to a hub bolt (not shown) via a wheel of the tire to fix the tire to the hub, the cylindrical portion 23 fits into the wheel hole, and the end face of the flange 22 is Sit on the open end face of the hole. When the hub nut 21 is screwed into the hub bolt with an impact wrench or another tool, even if the hub nut and the hub bolt are misaligned or tilted with each other, the straightening action is conceptually shown in FIGS. Thereby, a normal screwed state is easily generated.

FIG. 18 conceptually shows an example of a manufacturing process of the nut (female thread member) as described above. This example shows one process of manufacturing the nut material 30 by cold forging, and the stepped surface 5, the cylindrical guide surface 6, and the tapered guide are passed through an appropriate number of forging processes using a predetermined cold forging die. A nut blank 30 having the surface 7 is obtained. In this example, the nut material 30 is restrained between the forging dies 31, 32 (die) and 34 (sleeve), and the stepped surface 5 and, if necessary, the cylindrical guide surface 6 are punched 33.
And a tapered guide surface 7 is formed. After the nut blank 30 is obtained by such cold forging, a female screw is formed on the inner peripheral surface thereof by rolling or cutting, so that the stepped surface 4 is formed.
The female screw is formed from the predetermined portion of No. 5. If the above process is considered as a manufacturing method, using a cold forging die (including a punch or the like) as a female screw member material, the stepped surface 5,
Alternatively, the stepped surface 5 and the cylindrical guide surface 6, or the stepped surface 5, the cylindrical guide surface 6, and the tapered guide surface 7 are formed, and then the screw is formed so that the internal thread starts from a predetermined portion of the stepped surface 5. It is a manufacturing method to form.

On the other hand, the distal end surface of the guide projection 46 of the bolt as a male screw member is not limited to be parallel to the plane perpendicular to the axis of the bolt, and may be, for example, a screw-in straightening surface 45 with respect to the plane perpendicular to the axis of the bolt.
It may be formed obliquely as shown in FIG. 8 or independently of this. Furthermore, the tip of the guide convex portion is not limited to a plane that is not inclined or inclined, but may be, for example, a semi-spherical (dome-shaped) or other convex or convex form. Further, instead of a cylindrical guide convex portion, for example, a tapered guide convex portion having a smaller diameter toward the distal end side (a tapered shape) may be used.
Further, the distal end surface of the tapered guide portion may have a form (for example, a hemispherical shape) that is convex or bulges toward the above-described distal side.

FIG. 19 shows a bolt 51 according to another embodiment of the present invention. The bolt 51 is obtained by omitting the guide projection 46 from the bolt 41 shown in FIG. 8 and forming the end face of the leg 43 as a flat screw-in correction front face 55 as it is. The other points are the same as those in FIG. Even in such a bolt 51, although there is no guide convex portion 46, the screw-in correction front surface 55 can generate a moment in a direction to cancel the inclination with the nut 1 as shown in FIGS. This is effective in starting normal screwing.

FIG. 20 shows still another essential part of the bolt 52. With this bolt 52, the inclination (corresponding to a in FIG. 8) of the screw-in correction front surface 65 exceeds one pitch, for example, two pitches or less. This is the example described above.

In the above description, a stepped surface (a cylindrical guide surface and a tapered guide surface as necessary) is provided at one end of the nut as a female screw side screwing correction front surface. This is because the screwed end of the nut was determined at one end, and if the screwed end at which the screwing is planned to be screwed from any of both ends is not determined,
The stepped surfaces (a cylindrical guide surface and a tapered guide surface as necessary) can be formed at both ends. In this case, they may be formed symmetrically or asymmetrically.

In the above description, nuts have all been described as typical examples of the female screw member or the female screw portion. However, a female screw hole or a member having a female screw hole, for example, an opening is formed in a predetermined surface of a plate or the like. The female screw member (female screw member) having the stepped surface (a cylindrical guide surface or a tapered guide surface as necessary) formed at the screw-in end of the female screw member. In this case, the same screwing correction function can be performed.

In the above description, the bolts are all described as typical examples of the male screw member or the male screw portion. However, a male screw portion or the like which does not necessarily fit in the concept of the bolt, such as a male screw portion integrally projecting from the base or the like. The present invention can be similarly applied to a male screw member. That is, the above-described screwing correction front surface (a guide convex portion as necessary) is formed at the screwing side end of the male screw portion or the male screw member, and performs the same screwing correction function as in the case of a bolt. It can also be done.

Further, in the female screw portion, the female screw member or the female screw portion structure, it is not intended to rotate itself like a nut, and it is not scheduled to rotate (structurally). The above-mentioned stepped portion is provided on a female screw portion, a female screw member or a female screw portion structure which does not rotate itself when a screwing partner (for example, a bolt or the like) is scheduled to rotate. A surface (a cylindrical guide surface or a tapered guide surface as necessary) can be formed, and even in such a case, there is a certain effect in the screwing correction to the rotating counterpart.

Conversely, in a male screw portion, a male screw member, or a male screw portion structure, it is not intended to rotate itself like a bolt, and does not plan to rotate itself (structurally). In the case where the screwing counterpart (for example, a nut or the like) is scheduled to rotate, the above-described screw is attached to the external thread portion or the external thread member or the external thread portion structure that does not rotate itself. It is also possible to form an insertion straightening face (a guide projection if necessary), and even in this case, there is a certain effect in screwing straightening against a rotating counterpart.

[Brief description of the drawings]

FIG. 1 is a front view of a nut of a screwing unit according to an embodiment of the present invention.

FIG. 2 is a longitudinal sectional view thereof.

FIG. 3 is an enlarged sectional view of FIG. 2;

FIG. 4 is a perspective view for explaining a concept serving as a premise of a female screw side screwing correction front surface (stepped surface).

FIG. 5 is a side view of FIG. 4;

FIG. 6 is a conceptual diagram showing an elliptical loop which is a premise of a stepped surface.

FIG. 7 is a conceptual diagram showing an example of a stepped surface formed according to the loop of FIG.

FIG. 8 is a conceptual front view of a bolt of the screwing unit according to one embodiment of the present invention.

FIG. 9 is a perspective view conceptually illustrating a slanted elliptical loop which is a prerequisite for the front side of the screw on the screw side of the bolt.

FIG. 10 is an enlarged sectional view of FIG. 8;

FIG. 11 is a conceptual operation explanatory view of the present embodiment.

FIG. 12 is an explanatory view showing an example of a relative inclination of a nut / bolt immediately before screwing and a state where screwing has been started normally.

FIG. 13 is a view showing a nut according to another embodiment of the present invention.

FIG. 14 is a view showing still another nut.

FIG. 15 is a front view showing a hub nut as a female screw member according to still another embodiment of the present invention.

FIG. 16 is a longitudinal sectional view of FIG.

FIG. 17 is an enlarged sectional view of FIG. 16;

FIG. 18 is a cross-sectional view showing one example of a manufacturing process of the nut of the present invention.

FIG. 19 is a front view conceptually showing a bolt according to another embodiment of the present invention.

FIG. 20 is a diagram showing a main part of still another bolt of the present invention.

[Explanation of symbols]

 1, 11, 12, 21 Nut 3 Female thread 5, 25 Stepped surface (female screw side straightening front) 6, 26 Cylindrical guide surface 7, 27 Tapered guide surface 41, 51, 52 Bolt 44 Male screw 45 , 55, 65 Male screw side screw-in correction front (stepped surface) 46 Guide projection

Claims (14)

[Claims] 1. A screwing unit of a female screw member and a male screw member screwed to each other, wherein the female screw member has a plane inclined with respect to a plane perpendicular to a center line of the female screw member and an inner periphery of the female screw member. With the elliptical loop (annular line) intersecting with the surface as a reference, the inner peripheral surface near the opening end on the screw side of the female screw member is directed substantially outward along the loop so as to face outward of the female screw member. An annular and stepped female screw side screwing correction front surface for screw correction is formed in the inner peripheral edge of the female screw side screwing correction surface, the direction being perpendicular to the center line of the female screw member. Is smaller than the root diameter of the internal thread of the internal thread member, and an internal thread is formed from the internal thread side threaded straightening face. An ellipse where the plane inclined at an angle to the plane perpendicular to the line and the outer peripheral surface of the male thread member intersect On the basis of the loop (annular line), a screw-side screwing straightening face is formed at the screwing-side end of the male screw member substantially along this loop, and the outer edge of the screwing straightening face, The outer diameter in the direction perpendicular to the center line of the male screw member (outer diameter perpendicular to the axis) is made larger than the root diameter of the male screw of the male screw member, and the male screw is formed from the screwing front. Screwing is started through sliding contact by relative rotation between the female screw side screw-in correction front surface of the screw member and the male screw member screw-in correction front surface, wherein the female screw member and the male screw member are screwed together. unit. 2. The female screw member according to claim 1, wherein an elliptical loop (annular line) intersects a plane inclined with respect to a plane perpendicular to a center line of the female screw member and an inner peripheral surface of the female screw member. Along this loop, on the inner peripheral surface near the opening end on the threaded side of the female screw member, an annular and stepped female screw side screw for screwing correction is directed to the outside of the female screw member. The inner diameter of the inner peripheral edge of the internal thread of the female screw member in the direction perpendicular to the center line of the internal thread member is the valley of the internal thread of the internal thread member. The diameter is smaller than the diameter, and a female screw is formed from the female screw side screw-in correction front surface, and no female screw is formed on the opening end side of the female screw member from the annular female screw side screw-in correction surface. A cylindrical guide surface is formed concentrically with the center line of the female screw member. The surface is larger than the inner diameter at right angles to the axis of the inner peripheral edge of the female screw side screw-in correction front face, and has an inner diameter slightly larger than the root diameter of the female screw of the female screw member. The screwing unit according to claim 1, wherein the screwing unit is connected to the screwing straightening face. 3. The width of the cylindrical guide surface in the axial direction of the female screw member is 0.5 to 2 mm of the female screw of the female screw member.
3. The screwing unit according to claim 2, wherein the screwing unit corresponds to the pitch. 4. The degree of inclination of the elliptical loop with respect to the center line of the female screw member, which is a reference for forming the stepped surface-like female screw side screwing correction front surface, is determined by the opening of the female screw member of the loop. 4. The female screw member according to claim 1, wherein a difference between the point closest to the end and the farthest point in the axial direction of the female screw member is set to be equal to or less than two pitches of the female screw of the female screw member. A screwing unit of a female screw member and a male screw member. 5. The stepped surface-shaped female screw side screw-in correction face formed on the basis of the inclined elliptical loop, and the stepped surface-shaped female screw-side screw-in correction face itself further has the above-mentioned shape. The female screw member according to any one of claims 1 to 4, wherein the female screw member is formed to be inclined at a predetermined angle with respect to a plane perpendicular to the axis of the female screw member toward the opening end side of the female screw member. A screw unit with a screw member. 6. The stepped surface-shaped female screw side screw-in correction front face,
The screwing unit according to claim 5, wherein the inclination of the female screw member at a predetermined angle with respect to the plane perpendicular to the axis is approximately equal to the flank angle of the female screw of the female screw member. 7. The inner diameter of the female screw member in the direction perpendicular to the axis of the inner peripheral edge of the stepped surface-shaped female screw side screwing correction front face is larger than the root diameter of the female screw of the female screw member. 1 to 6
A screwing unit of the female screw member and the male screw member according to any one of the above. 8. An opening end of the female screw member on the screw-in side,
A tapered guide surface that expands outward in the axial direction of the female screw member is formed concentrically with the female screw of the female screw member, and the tapered guide surface has a small-diameter end and a stepped surface-like female screw side. The screwing unit according to any one of claims 1 or 4 to 7, wherein the screwing correction front surface is formed. 9. An opening end of the female screw member on the screwing side,
A tapered guide surface that extends outward in the axial direction of the female screw member is formed concentrically with the female screw of the female screw member, and the cylindrical guide surface is formed from the small-diameter end of the tapered guide surface. 4. The screwing unit according to claim 2, further comprising a stepped surface-like female screw side screw-in correction front surface formed from an inner end of the cylindrical guide surface. 10. The male screw member is substantially formed on the basis of an elliptical loop (annular line) in which a plane inclined with respect to a plane perpendicular to a center line of the male screw member and an outer peripheral surface of the male screw member intersect. Along this loop, an annular male screw side screw-in correction surface is formed at the screw-in side end of the male screw member, and the outer peripheral edge of the screw-in correction surface is perpendicular to the center line of the male screw member. Diameter in various directions (outside diameter perpendicular to axis)
Is made larger than the root diameter of the external thread of the external thread member, and the external thread is formed from the front surface of the external thread member. A cylindrical guide projection is formed concentrically with the center line of the external thread member from the entry side end face, and the outer diameter of the guide projection is slightly smaller than the root diameter of the external thread of the external thread member. The screwing unit of a female screw member and a male screw member according to any one of claims 1 to 9, characterized in that: 11. The female screw according to claim 10, wherein the protrusion of the guide projection in the axial direction of the male screw member is equivalent to 0.5 to 2 pitches of the male screw of the male screw member. A screw unit of a screw member and a male screw member. 12. The degree of inclination of the elliptical loop with respect to the center line of the external thread member as a reference for forming the front surface of the external thread member is determined by the point closest to the external thread member threaded end of the loop. The female screw member and the male screw member according to any one of claims 1 to 11, wherein a difference between the furthest point and the male screw member in the axial direction is set to be equal to or less than two pitches of the male screw of the male screw member. Screw unit with. 13. The male screw-threaded straightening surface formed on the basis of the slanted elliptical loop, the annular screwed-in straightening surface itself further has a plane perpendicular to the axis of the male screw member. 13. The screwing of the female screw member and the male screw member according to any one of claims 1 to 12, wherein the female screw member is formed to be inclined at a predetermined angle so as to taper toward the threaded end side of the male screw member. unit. 14. The inclination of the male screw side screwing correction front surface at a predetermined angle with respect to a plane perpendicular to the axis of the male screw member is approximately equal to the flank angle of the male screw of the male screw member. A screwing unit of the female screw member and the male screw member described in the above.