JP3218084U - Screw member - Google Patents

Abstract

A screw member capable of exhibiting a high locking function while having good workability and high seizure resistance is provided. A spiral notch groove 14 formed at a tip of a first thread 13, a thread side surface 13 a of the first thread 13, and a first inner side surface 14 a of the notch groove 14. A first corner 15 defined between the second threaded side surface 13b of the first thread 13 and a second corner 16 formed between the second inner side surface 14b of the notch groove 14; The first thread angle α of the first thread 13 is set to be smaller than the second thread angle β of the second thread 22, and the first screw member 10 is screwed to the second thread member 20. When this is done, an axial gap is created between the root of the first thread 13 and the tip of the second thread 22, and the first corner 15 and the second corner 16 are notched grooves 14. A screw member 1 which is elastically deformed to the side. [Selection] Figure 2

Description

  The present invention relates to a screw member for fastening a plurality of fastened members, and more particularly to a technique for preventing loosening of fastening.

  In order to fasten a plurality of members to be fastened, screw members such as bolts and nuts are often used.

  In order to prevent the tightened screw members from loosening, it is common to use a locking member such as a spring washer, but the screw members fastened to each other without using such additional parts. Self-locking screw members have been developed that can prevent loosening of the screw.

  For example, in Patent Document 1, the thread angle of the thread of the first thread member is set smaller than the thread angle of the thread of the second thread member engaged with the first thread member, A screw member provided with a slit extending from the tip portion to the root portion in the radial direction is described. According to this screw member, when the first screw member and the second screw member are screwed together, both side portions sandwiching the slit of the thread of the first screw member are elastically deformed in the direction of narrowing the slit, respectively, and its restoring force Thus, the entire thread side face is strongly pressed against the entire thread side face on the other side, so that a high frictional resistance can be generated between the thread side faces of both screw members to prevent loosening of the fastening.

Japanese Examined Patent Publication No. 56-19492

  However, as in the screw member described in the above-mentioned Patent Document 1, in the screw member in which a high frictional resistance is generated between the screw thread side surfaces of both screw members, a fastening locking function is generated. When screwing together, it is necessary to relatively rotate the screw member with a strong force against the high frictional resistance. Therefore, the workability at the time of fastening the screw members is poor, and there is a problem that both screw members may be seized by frictional heat generated by the frictional resistance. On the other hand, if the frictional resistance generated between the screw thread side surfaces of the two screw members is reduced in order to improve workability and prevent seizure, the fastening loosening prevention function is lowered.

  This invention is made | formed in view of such a subject, The objective provides the screw member which can exhibit the high locking | rock prevention function, having favorable workability | operativity and high seizure resistance. There is.

  The screw member of the present invention includes a first screw member having a first screw thread projecting spirally from a screw body, and a second screw coupled to the first screw thread by relative rotation about an axis. A screw member having a second screw member provided with a screw thread, the first inner surface and the second inner surface facing each other, and a flat continuous to the first inner surface and the second inner surface A spiral cut-out groove formed at the tip of the first screw thread, and a partition formed between one screw thread side surface of the first screw thread and the first inner surface. A first corner portion, and a second corner portion defined between the other thread side surface of the first thread and the second inner surface, and the pair of the first thread A first thread angle formed by a thread side surface is set smaller than a second thread angle formed by a pair of thread side surfaces of the second thread; When the first thread angle is in the range of 48 ° to 58 °, the second thread angle is 60 °, and the thread height of the first thread is H, the first corner portion And the projecting height of each of the second corners from the bottom surface is 0.1H to 0.4H, and when the first screw member is screwed to the second screw member, the first screw An axial gap is created between the thread side surface at the root of the thread and the thread side surface at the tip of the second thread, and the tip of the first thread is sandwiched between the roots of the second thread. When the first corner portion and the second corner portion are elastically deformed toward the notch groove, and the first screw member and the second screw member are further rotated relative to each other, tightening is performed. The side of the thread receiving the axial force of the first thread and the thread of the second thread The first screw thread and the second screw thread are elastically deformed so that the gap between the screw thread side surface is narrowed, and the screw thread side surface in the range from the tip part to the intermediate part of the first screw thread is the first screw thread side. It is characterized by strongly pressing from the middle part of the two screw threads to the screw thread side surface at the root part.

  The screw member of the present invention has the above configuration, wherein the first corner portion and the second corner portion are symmetrical with respect to the axial direction across the bottom surface, and the first screw member is used as the second screw member. When screwed together, between one thread side surface at the root of the first thread and one thread side surface at the tip of the second thread, and the other at the root of the first thread It is preferable that an axial gap is formed between the thread side surface and the other thread side surface at the tip of the second thread.

  The screw member of the present invention is preferably configured such that, in the above configuration, the first screw member is one of a bolt and a nut, and the second screw member is either the bolt or the nut.

  According to the present invention, it is possible to provide a screw member capable of exhibiting a high locking function while having good workability and high seizure resistance.

It is a partially cutaway sectional view showing a screw member which is an embodiment of the present invention in a coupled state. It is sectional drawing which shows the detail of the 1st thread of a 1st screw member. It is sectional drawing which shows the detail of the screw coupling | bond part of a 1st screw member and a 2nd screw member. It is sectional drawing which shows the modification of the 1st screw member shown in FIG.

  Hereinafter, the present invention will be described more specifically with reference to the drawings.

  As shown in FIG. 1, the screw member 1 which is one embodiment of the present invention includes a first screw member 10 configured as a bolt and a second screw member 20 configured as a nut. The screw member 1 can be used, for example, to fasten the fastened members 2 and 3.

  The first screw member 10 has a head portion 11 and a shaft portion 12, and the head portion 11 has six action surfaces 11a (only three appear in FIG. 1) on its outer periphery, The outer shape is a substantially hexagonal column shape. These action surfaces 11a are parallel to each other as a pair of action surfaces, and a tool such as a spanner (not shown) can be engaged therewith. The shaft portion 12 constitutes a screw body of the first screw member 10, and a first screw thread 13 protruding in a spiral shape is provided on the outer peripheral surface thereof. The first thread 13 has a pair of thread side surfaces 13a and 13b, and these thread side surfaces 13a and 13b are each formed in a flat inclined surface in a cross-sectional view. In the illustrated case, in the first thread 13, the flank angle of one thread side face 13 a and the flank angle of the other thread side face 13 b are the same.

  The second screw member 20 has six action surfaces 20a (only two appear in FIG. 1) on its outer periphery, and its outer shape is a substantially hexagonal column shape. These action surfaces 20a are parallel to each other and can be engaged with a tool such as a spanner (not shown). A screw hole 21 that opens to both end faces 20b and 20c of the second screw member 20 is provided at the axis of the second screw member 20, and a second screw thread 22 is provided in the screw hole 21. Yes. The second screw thread 22 protrudes spirally from the inner peripheral surface of the screw hole 21 and can be screw-coupled to the first screw thread 13 by relative rotation about the axis. The pair of thread side surfaces 22a and 22b of the second thread 22 is also formed as a flat inclined surface in cross-sectional view, and the flank angle of one thread side surface 22a and the flank of the other thread side surface 22b. The corners are the same.

  A notch groove 14 is formed at the tip end portion (radially outer end portion) of the first screw thread 13 provided in the first screw member 10. As shown in FIG. 2, the notch groove 14 has a first inner side surface 14 a and a second inner side surface 14 b facing each other, and a bottom surface 14 c, and has a spiral shape along the tip of the first screw thread 13. It extends to. The bottom surface 14c is parallel to the axis of the first screw member 10, that is, formed in a flat shape in a sectional view shown in FIG. 2, and is continuous with the first inner side surface 14a and the second inner side surface 14b.

  By forming the notch groove 14, a first corner 15 and a second corner 16 are provided at the tip of the first thread 13.

  The first corner 15 is defined between one thread side surface 13 a and the first inner surface 14 a of the first thread 13, and the second corner 16 is the other thread of the first thread 13. A partition is formed between the side surface 13b and the second inner side surface 14b. The first corner 15 and the second corner 16 can be elastically deformed so as to narrow the width of the notch groove 14 in the axial direction toward the notch groove 14. In the case shown in the drawing, the notch groove 14 is provided at the center in the axial direction of the distal end portion of the first thread 13 so that the first corner portion 15 and the second corner portion 16 are in the axial direction across the bottom surface 14c. It has a symmetrical shape. Further, the first corner portion 15 and the second corner portion 16 are each formed in a triangular shape having a sharp tip at the acute end in the cross-sectional view shown in FIG.

  The first screw thread angle α formed by the pair of screw thread side surfaces 13 a and 13 b of the first screw thread 13 provided on the first screw member 10 is a pair of the second screw thread 22 provided on the second screw member 20. It is set smaller than the second screw thread angle β formed by the screw thread side faces 22a, 22b. In FIG. 2, for the sake of convenience, the angle of the valley formed by one thread side 22a and the other thread side 22b of a pair of adjacent second threads 22 is shown as a second thread angle β. However, the angle of the valley portion and the angle formed by the pair of thread side surfaces 22a and 22b of the second thread 22 are the same.

  Further, in the state where the first screw member 10 is not screw-coupled to the second screw member 20, the axial width dimension at the distal end portion and the intermediate portion of the first screw thread 13 is the root of the adjacent second screw thread 22. It is wider than the interval (groove width) in the axial direction at the portion. On the other hand, in the state where the first screw member 10 is not screw-coupled to the second screw member 20, the axial width dimension at the root portion of the first screw thread 13 is the axis at the tip of the adjacent second screw thread 22. It is narrower than the interval in the direction.

  As shown in FIG. 3, when the first screw member 10 having such a configuration is screw-coupled to the second screw member 20, both screw thread side surfaces 13 a and 13 b of the first screw thread 13 are respectively connected to the first screw member 13. In the range from the middle portion to the tip portion of the screw thread 13, it contacts the pair of screw thread side surfaces 22 a and 22 b at the root portion of the pair of adjacent second screw threads 22 and is sandwiched between the screw thread side surfaces 22 a and 22 b. . As a result, the first corner 15 and the second corner 16 provided at the tip of the first screw thread 13 respectively increase the axial width of the notch groove 14 toward the notch groove 14 side. It will be elastically deformed to narrow. Therefore, even if vibration or impact is applied to the first screw member 10 and the second screw member 20 after the screw member 1 is fastened, the pair of screw thread side surfaces 13a and 13b at the tip of the first screw thread 13 is Due to the repulsive force (restoring force) of the first corner portion 15 and the second corner portion 16 that are elastically deformed, the first screw member 10 and the first screw member 10 are always strongly pressed against the thread side surfaces 22a and 22b at the root portion of the second thread 22 A high locking effect is produced between the second screw member 20 and the second screw member 20.

  Further, when the first screw member 10 is screw-coupled to the second screw member 20, the range from the tip portion to the middle portion of the first screw thread 13 is in contact with the pair of screw thread side surfaces 22 a and 22 b of the second screw thread 22. However, the thread side surfaces 13a and 13b at the root portion of the first thread 13 do not contact the thread side surfaces 22a and 22b at the tip of the second thread 22, and there is an axial direction between them. A gap 4 is generated. When the first screw member 10 and the second screw member 20 that are screw-coupled to each other are further rotated relative to each other and tightened, the axial force generated between them increases, and the axial force of the first thread 13 is increased. The first thread 13 and the second thread 22 are elastically deformed so that the gap 4 between the thread side 13a on the receiving side (load support side) and the thread side 22b of the second thread 22 is narrowed, The thread side surface 13a in the range from the tip of the first screw thread 13 to the middle part is strongly pressed from the middle part of the second screw thread 22 to the screw thread side surface 22b in the root portion, and a further effect of preventing loosening occurs. It will be.

  Here, as described above, when the first screw member 10 and the second screw member 20 are screwed together, the screw thread side surfaces 13a and 13b at the root of the first screw thread 13 and the second screw Since the axial gap 4 is formed between the screw thread side surfaces 22a and 22b at the tip of the mountain 22, the frictional resistance generated between the first screw member 10 and the second screw member 20 is reduced. Thus, the force (torque) required for tightening the first screw member 10 and the second screw member 20 can be reduced as compared with the case where the entire screw thread side surfaces are brought into contact with each other. . In particular, in the present embodiment, between one screw thread side surface 13 a at the root of the first screw thread 13 and one screw thread side surface 22 a at the tip of the second screw thread 22, Since the axial gap 4 is generated between the other thread side surface 13b at the root portion and the other thread side surface 22b at the tip of the second thread 22, the first screw member 10. And the second screw member 20 can be reduced in frictional resistance on both screw thread sides. Thereby, the operation | work which fastens the 1st screw member 10 and the 2nd screw member 20 can be made easy and the workability | operativity can be improved, producing the high locking effect. In addition, since the frictional resistance between the first screw member 10 and the second screw member 20 can be reduced, the first screw member 10 is fastened when the first screw member 10 and the second screw member 20 are fastened. The frictional heat generated between the first screw member 10 and the second screw member 20 can be reduced, and seizure can be prevented from occurring between the first screw member 10 and the second screw member 20.

  Further, in a state where the first screw member 10 is screw-coupled to the second screw member 20 and tightened to each other, the screw thread side surface 13a on the side receiving the axial force of the first screw thread 13 is seen from the tip in a sectional view. It will be in the state elastically deformed by the circular arc surface so that it may leave | separate from the thread side 22b of the 2nd thread 22 gradually toward a root part. Accordingly, after the screw member 1 is fastened, even if vibration or impact is applied to the first screw member 10 and the second screw member 20, the first screw elastically deformed so that the thread side surface 13a has an arcuate shape. These vibrations and impacts can be absorbed by the further elastic deformation or restoring force of the mountain 13 and a higher locking effect can be exhibited.

  Furthermore, since the notch groove 14 is provided only in the range of the tip portion of the first screw thread 13 and does not reach the middle part or the root part of the first screw thread 13, Workability when the screw member 1 is screw-coupled by reliably generating the axial gap 4 between the screw thread side surfaces 13a, 13b and the screw thread side surfaces 22a, 22b at the tip of the second screw thread 22, The seizure resistance and the locking effect can be improved with certainty.

  In the screw member 1 in the present embodiment, the first thread angle α is in the range of 48 ° to 58 °, the second thread angle β is 60 °, and as shown in FIG. The protrusion height from the bottom surface 14c of each of the portion 15 and the second corner portion 16 is set to a height that is in the range of 0.1H to 0.4H when the thread height of the first thread 13 is H. It is preferable to do this. With the above setting, the force (torque) required when the first screw member 10 and the second screw member 20 are screwed together and tightened is sufficiently reduced to such an extent that the work can be easily performed. The first screw member 10 and the second screw member 20 are reliably prevented from being seized, and the effect of preventing the loosening between the first screw member 10 and the second screw member 20 is sufficiently increased, and the screw The strength of the first thread 13 at the time of coupling can be sufficiently ensured.

  Here, in the screw member 1 having the above-described configuration, the protruding height (the diameter of the notch groove 14) from the bottom surface 14 c of each of the first corner portion 15 and the second corner portion 16 provided at the distal end portion of the first thread 13. Direction depth), and the first thread angle α and the second thread angle β are set to appropriate values, so that the workability, seizure resistance, and loosening prevention when the screw member 1 is screw-coupled are set. Although the effect can be secured with a high balance, there is a problem in that the strength of the first thread 13 at the time of screw connection may be insufficient if the above three effects are to be secured with a high balance. Will occur. This problem is a new problem unique to the screw member 1 of the present application, which is not found in the conventional screw member. The present applicant has made various studies in order to solve the above problems, and found that the above problems can be solved by using the above settings.

  It goes without saying that the present invention is not limited to the above-described embodiment, and various modifications can be made without departing from the scope of the invention.

  For example, in the illustrated case, the first screw member 10 is a bolt and the second screw member 20 is a nut, but the first screw member may be a nut and the second screw member may be a bolt.

  Moreover, in the said embodiment, although the 1st corner | angular part 15 and the 2nd corner | angular part 16 are formed in the triangle shape where the front-end | tip sharpened sharply by sectional view, it is not restricted to this, The side of a thread As shown in FIG. 4, for example, as shown in FIG. 4, the tip is rounded into an arc shape if it is defined between 13a and the first inner side surface 14a or between the thread side surface 13b and the second inner side surface 14b. The shape can be variously changed, such as a triangular shape.

  Furthermore, in the said embodiment, although the head 11 and the 2nd screw member 20 of the 1st screw member 10 are each formed in the substantially hexagonal column shape, not only this but engaging with arbitrary tools. Any shape can be used as long as the shape can be rotated using the tool.

DESCRIPTION OF SYMBOLS 1 Screw member 2 Fastened member 3 Fastened member 10 1st screw member 11 Head 11a Action surface 12 Shaft part 13 1st thread 13a Thread side 13b Thread side 14 Notch groove 14a 1st inner surface 14b 2nd Inner side surface 14c Bottom surface 15 First corner portion 16 Second corner portion 20 Second screw member 20a Working surface 20b End surface 20c End surface 21 Screw hole 22 Second thread 22a Thread side 22b Thread side α First thread angle β First 2 thread angle

Claims (3)

A first screw member having a first screw thread projecting spirally from the screw body; and a second screw thread having a second screw thread screw-coupled to the first screw thread by relative rotation about an axis. A screw member having a screw member,
A first inner surface and a second inner surface facing each other; a flat bottom surface continuous to the first inner surface and the second inner surface; and a spiral formed at a tip of the first thread Notch groove,
A first corner section defined between one thread side surface of the first thread and the first inner surface;
A second corner portion defined between the other thread side surface of the first thread and the second inner surface;
A first thread angle formed by a pair of thread sides of the first thread is set smaller than a second thread angle formed by a pair of thread sides of the second thread;
The first thread angle is in the range of 48 ° to 58 °, the second thread angle is 60 °, and
When the thread height of the first thread is H, the protruding height from the bottom surface of each of the first corner and the second corner is 0.1H to 0.4H,
When the first screw member is screw-coupled to the second screw member, an axial direction is provided between a screw thread side surface at the root of the first screw thread and a screw thread side surface at the tip of the second screw thread. While the gap is generated, the tip of the first thread is sandwiched between the roots of the second thread, and the first corner and the second corner are elastically deformed toward the notch groove,
When the first screw member and the second screw member are further rotated relative to each other and tightened, a thread side surface on the side receiving the axial force of the first screw thread and a thread side surface of the second thread thread The first screw thread and the second screw thread are elastically deformed so that the gap between them is narrowed, and the screw thread side surface in the range from the tip part to the intermediate part of the first screw thread is the second screw thread. A screw member characterized by being strongly pressed against a screw thread side surface at a root portion from an intermediate portion. The first corner and the second corner are symmetrical with respect to the axial direction across the bottom surface,
When the first screw member is screw-coupled to the second screw member, between one screw thread side surface at the root of the first screw thread and one screw thread side surface at the tip of the second screw thread. And an axial gap is formed between the other thread side surface at the root of the first thread and the other thread side surface at the tip of the second thread. Screw member.   The screw member according to claim 1 or 2, wherein the first screw member is one of a bolt and a nut, and the second screw member is either the bolt or the nut.

Images