CN103967908A - Screw structure - Google Patents

Abstract

A screw structure is suitable for screwing into a screw hole with a female thread, and comprises a head and a rod. The head has a first axis as its axis and extends along the first axis, and the rod is connected and formed on the bottom side of the head and has a second axis spaced from the first axis as its axis and extends along the second axis. By designing that the head is eccentrically arranged on the rod, the force arm during rotation is increased, thereby improving the locking and anti-loosening effects.

Description

screw structure

technical field

The invention relates to a screw, in particular to a screw structure.

Background technique

Referring to Fig. 1 and Fig. 2, it is an existing screw 1, the screw 1 has a head 10 centered on an axis L and extending along the axis L, and a head 10 connected to the head 10 and extending along the axis L The shaft 11 is the shaft center and extends along the axis L. The shaft 11 has a threaded segment 111 surrounding the axis L, wherein the head 10 and the shaft 11 are configured in a coaxial manner, so when When the user uses a hand tool (not shown in the figure) to operate the head 10 to drive the rod 11 to rotate, the rotational force arm is the vertical distance from the axis L to a point of application of force. The arm of force is provided entirely by the length of the hand tool, and the structure of the screw 1 itself does not make any contribution to the arm of force.

On the other hand, in the assembly of workpieces, the screw 1 is used to fix both a first workpiece 300 with a through hole 301 and a second workpiece 400 with a screw hole 401, because the screw hole 401 A female thread 402 and the thread section 111 of the screw 1 must have a tolerance in size matching. When the user rotates the screw 1 to tighten, the unstressed side 112 of the thread section 111 and the female thread 402 is bound to produce a backlash 500. However, air will be entrapped in the back gap 500, so under long-term use, the threaded section 111 of the screw 1 or the female thread 402 of the screw hole 401 will be gradually corroded. When affected by external force or vibration, it is easy to cause the screw 1 to loosen. In view of the above shortcomings, although some people have used cementing agents to improve them, but in this way, the cost of the cementing agent is bound to be increased, and there is an additional process in the assembly, so there is still room for improvement .

Contents of the invention

The purpose of the present invention is to provide a screw structure with good locking and anti-loosening effects and a large rotational force arm.

The screw structure of the present invention includes a head and a rod.

The head is centered on a first axis and extends along the first axis.

The rod portion is connected and formed on the bottom side of the head, and is centered on a second axis spaced from the first axis and extends along the second axis.

In the screw structure of the present invention, the head has a wrench groove recessed downward from the top surface.

In the screw structure of the present invention, the groove of the wrench is eccentrically recessed on the head.

The screw structure of the present invention is adapted to be screwed into a screw hole having a female thread, the shank includes a first thread segment surrounding the second axis, and a first thread segment surrounding the second axis and interposed between the first A second thread segment between the thread segment and the head, the first thread segment has a first back side ventral surface facing away from the head and spaced from the female thread, and a first back side face facing the head and abutting against the head On the first pressure flank surface of the female thread, the second thread segment has a second back flank facing away from the head and abutting against the female thread, and a second back flank facing the head and abutting against the female thread. The second pressure flank of the female thread.

In the screw structure of the present invention, the length of the second thread segment is greater than or equal to half of the length of the rod.

In the screw structure of the present invention, the shank is slightly tapered and extends along the second axis in a direction away from the head.

In the screw structure of the present invention, the cross-sectional shape of the head is circular.

In the screw structure of the present invention, the cross-sectional shape of the head is petal-shaped.

The beneficial effect of the present invention is that: the head and the rod are designed eccentrically rather than coaxially, so that the user can have a larger turning force arm when turning, so that the force can be applied It is labor-saving, thereby improving the effect of locking and anti-loosening.

Description of drawings

Fig. 1 is a sectional view, illustrates the situation of existing a kind of screw lock;

Fig. 2 is a partial enlarged view of the existing screw;

Fig. 3 is a cross-sectional view of a first preferred embodiment of the screw structure of the present invention, illustrating the situation of the screw lock;

Figure 4 is a partial enlarged view of the first preferred embodiment, illustrating a first threaded section and a second threaded section of a shank;

Fig. 5 is a top view of this first preferred embodiment;

Fig. 6 is a cross-sectional view of a second preferred embodiment of the screw structure of the present invention;

Fig. 7 is a cross-sectional view of a third preferred embodiment of the screw structure of the present invention;

Fig. 8 is a cross-sectional view of a fourth preferred embodiment of the screw structure of the present invention;

Fig. 9 is a sectional view of a fifth preferred embodiment of the screw structure of the present invention;

Figure 10 is a top view of the fifth preferred embodiment, illustrating a head and a wrench groove;

Fig. 11 is a sectional view of a sixth preferred embodiment of the screw structure of the present invention;

Figure 12 is a top view of the sixth preferred embodiment, illustrating a head and a wrench notch.

Detailed ways

The present invention will be described in detail below in conjunction with the accompanying drawings and embodiments.

Referring to Fig. 3, Fig. 4, and Fig. 5, the first preferred embodiment of the screw structure of the present invention is suitable for screwing in a screw hole 201 with a female thread 202, the screw structure includes a head 2, and a rod Part 3. The head 2 and the rod 3 are integrally formed of metal material.

The head 2 is centered on a first axis L1 and extends along the first axis L1 for operation of hand tools. In this first preferred embodiment, the head 2 has a top surface A wrench groove 21 is recessed downward at the middle position and is used for inserting a hexagonal wrench (not shown in the figure).

The rod part 3 is connected and formed on the bottom side of the head part 2. The rod part 3 is centered on a second axis L2 spaced apart from the first axis L1 and is along the second axis L2 and faces away from the head part 2. Gradually contract and extend. The shaft 3 includes a first threaded section 31 surrounding the second axis L2 and a second threaded section 32 surrounding the second axis L2 and interposed between the first threaded section 31 and the head 2 . Wherein, in this first preferred embodiment, the diameter at the place where the rod 3 is connected to the head 2 is a first diameter d1, the diameter at the middle section of the rod 3 is a second diameter d2, and the rod The diameter of the tail end of part 3 is a third diameter d3, and satisfies the relationship of the first diameter d1>the second diameter d2>the third diameter d3, so that the rod part 3 has a slight taper shape, and the second thread segment The length of 32 is equal to half of the length of the rod 3 . Of course, in other practical manufacturing, the length of the second thread segment 32 can also be designed to be greater than half of the length of the rod portion 3 , but it is not limited thereto.

The first thread segment 31 has a first dorsal ventral surface 311 facing away from the head 2 and spaced apart from the female thread 202 , and a first back surface 311 facing the head 2 and abutting against the female thread 202 . Pressure flank ventral surface 312 . Wherein, the structure of the first threaded section 31 is equivalent to the threaded section 111 (see FIG. 1 ) described in the background art, which is a commonly known thread form in the market.

The second thread segment 32 has a second dorsal ventral surface 321 facing away from the head 2 and abutting against the female thread 202 , and a second side surface 321 facing the head 2 and abutting against the female thread 202 . Pressure flank ventral surface 322 . Wherein, the contour shape of the second dorsal ventral surface 321 is asymmetrical to the contour contour of the second pressure flank surface 322. As shown in FIG. Below is the partial enlargement of the first threaded segment 31. It can be clearly understood from FIG. 4 that the pitch of the first threaded segment 31 is P1, the pitch of the second threaded segment 32 is P2, and the first The thread segment 31 has the same pitch as the second thread segment 32 . The second dorsal ventral surface 321 is more deviated from the thread centerline M than the first dorsal ventral surface 311, that is to say, the second dorsal ventral surface 321 of the second thread segment 32 is in a relatively full shape. so that when the female thread 202 is tightened, the second dorsal ventral surface 321 can closely fit the female thread 202. This feature is the same as that of the thread segment 111 (see FIG. 2) in the background technology when pressing The state is different when it is tight to the female thread 402 (see FIG. 2 ).

In assembly use, a first workpiece 100 with a through hole 101 and a second workpiece 200 with the screw hole 201 are superimposed on each other, and after the through hole 101 and the screw hole 201 are aligned with each other, Then the rod 3 is passed through the through hole 101, and the head 2 is rotated by using an Allen wrench to slowly perform the tightening action, and when the force is first applied, because the first threaded section 31 first touches the The female screw thread 202, because there is a tolerance in the size fit, is relatively labor-saving in applying force, and when the rod 3 is gradually rotated and moves down to allow the second thread segment 32 to contact the female screw thread 202 When threading 202, since the second back side ventral surface 321 and the second pressure side ventral surface 322 are all in close contact with the two sides of the female thread 202, it is necessary to apply a relatively large force in applying force, but such a Come, when it is completely tightened, it can effectively reduce the generation of backlash, and then improve the effect of locking and anti-loosening.

In addition, since the head 2 and the rod 3 are designed in a non-coaxial manner, that is, eccentric, as shown in FIG. 5 , the axis between the head 2 and the rod 3 is There must be an offset X1, but compared with the background art, the offset X1 does not exist because the head 10 (see FIG. 1 ) and the rod 11 (see FIG. 1 ) are coaxial. Therefore, when the user uses the hex wrench to rotate the head 2 of the present invention, the length of the moment arm is the sum of a vertical distance X2 from a force source F to the first axis L1 and the offset X1, so Compared with the background technology, the present invention increases the force arm due to the extra offset X1, so it can save more effort in applying force in rotation and is beneficial to tightening.

Referring to Fig. 3 again, since the head 2 is eccentric to the rod 3, so, after being tightened and locked, the bottom side of the head 2 is in contact with the first workpiece 100 with an asymmetrical contact surface, as A large contact surface S1 and a small contact surface S2 shown in Fig. 3, like this, because the area of this large contact surface S1 is big, the frictional resistance that it produces also can be bigger, so make the present invention in pressing After tightening, it is less likely to be loosened by external forces.

Referring to Fig. 6, it is the second preferred embodiment of the screw structure of the present invention, and its content is roughly the same as that of the first preferred embodiment, except that the cross-sectional shape of the head 2 is hexagonal, which is designed to be used In the state of being operated by an open-end wrench (not shown).

Referring to FIG. 7 , it is a third preferred embodiment of the screw structure of the present invention, and its content is roughly the same as that of the first preferred embodiment, the difference being that the overall shape of the head 2 is slightly hemispherical.

Referring to Fig. 8, it is the fourth preferred embodiment of the screw structure of the present invention, its content is roughly the same as that of the first preferred embodiment, the difference is that the overall shape of the head 2 is slightly hemispherical, and the wrench The groove 21 is eccentrically recessed in the head 2, so that the arm of force is increased, and the effort in applying force can be saved, so as to improve the effect of tightening and preventing loosening.

Referring to Figure 9 and Figure 10, it is the fifth preferred embodiment of the screw structure of the present invention. In this way, the head 2 increases the arm of force, which can save more effort in applying force, so as to improve the effect of tightening and preventing loosening.

Referring to Fig. 11 and Fig. 12, it is the sixth preferred embodiment of the screw structure of the present invention, the content of which is roughly the same as that of the first preferred embodiment, the difference is that the cross-sectional shape of the head 2 is petal-shaped, which is It is designed to be operated by a torx wrench (not shown in the figure), and it is relatively labor-saving in applying force. In addition, the wrench groove 21 is eccentrically recessed in the head 2, so when choosing to use the hexagonal wrench to operate, the force arm is also increased, and the force can also be relatively labor-saving. These two features , can be used to enhance the tightening and anti-loosening effects.

In summary, the screw structure of the present invention has the following advantages and effects:

1. Due to the design of the head 2 and the rod 3 being eccentric rather than coaxial, the user can have a larger moment arm when turning, so that the turning can be relatively labor-saving, and further Improve the effect of locking and anti-loosening.

2. With the design that the second dorsal ventral surface 321 of the second thread segment 32 can be attached to the female thread 202, after tightening, the present invention can effectively reduce the generation of backlash, thereby greatly improving locking And the effect of anti-loosening.

3. Due to the design that the second dorsal ventral surface 321 of the second thread segment 32 can be attached to the female thread 202, when it is tightened, the generation of backlash can be effectively reduced, so the cementing agent can be relatively reduced use to reduce assembly costs and assembly procedures.

Claims (8)

1. a screw structural, comprises a head and a bar portion, it is characterized in that:

This head be take a first axle as axle center and is extended along this first axle;

This bar portion connect take shape in this head bottom side and take one with this first axle the second axis separately as axle center and along this second Axis Extension.

2. screw structural as claimed in claim 1, is characterized in that: this head has a spanner groove being down arranged with by end face.

3. screw structural as claimed in claim 2, is characterized in that: being arranged with in this head of this spanner groove bias.

4. if claim 1 is to the screw structural as described in any one in claim 3, it is characterized in that: this screw structural is applicable to screw lock in a screw with a box thread, this bar portion comprises that one around first thread section of this second axis, and one around this second axis and the second thread section between between this first thread section and this head, this first thread section have one back on this head and with this box thread first dorsal part outside of belly separately, and one be intended for this head and stick to first outside of belly on the pressure side in this box thread, this second thread section has one back on this head and sticks to the second dorsal part outside of belly in this box thread, and one be intended for this head and stick to second outside of belly on the pressure side in this box thread.

5. screw structural as claimed in claim 4, is characterized in that: the length of this second thread section is more than or equal to half of this bar minister degree.

6. screw structural as claimed in claim 1, is characterized in that: this bar portion is slightly tapering and along this second axis and towards away from this cephalad direction contracting Shu Yanshen.

7. screw structural as claimed in claim 1, is characterized in that: the cross-sectional shape of this head is for circular.

8. screw structural as claimed in claim 1, is characterized in that: the cross-sectional shape of this head is petal.