CN2508043Y

CN2508043Y - Reverse self-locking self-tapping screw with two-way thread

Info

Publication number: CN2508043Y
Application number: CN 01259417
Authority: CN
Inventors: 石季尧
Original assignee: Individual
Current assignee: Individual
Priority date: 2001-08-24
Filing date: 2001-08-24
Publication date: 2002-08-28
Anticipated expiration: 2011-08-24

Abstract

The utility model relates to a reversal self-tapping and self-locking screw with two-way threads. The screw rod thread of the utility model is divided into two sections, one section is a right-handed thread and the other section is a left-handed thread. Two ends of the screw rod are provided with rod heads whose diameters are shorter than the bottom diameters of the threads. A tooth central dividing line m which is perpendicular to the screw rod axial line and two side inclined planes of the tooth form two tooth face hemi-angles, alpha and beta, in the axial section of the right-handed thread and the right-handed thread, wherein the tooth face hemi-angle alpha facing the screw rod pushing direction is larger than the tooth face hemi-angle beta reversing to the screw rod pushing direction. The top portion of the thread tooth is provided with a round arc with small diameter. The tooth face hemi-angle alpha of the left-handed thread and the tooth face hemi-angle beta of the right-handed thread are reversely arranged. The left connecting member and the right connecting member of the utility model are connected in the form of pushing and self-tapping without rotation. The pushing speed is smooth and fast, and also the rotary retreat and self-locking are achieved, thereby eliminating the hidden danger caused by loosing and retrogressing of the screw, avoiding the falling and breaking phenomenon of the screw fastener , and enhancing the safety and reliability property of mechanical equipment.

Description

The reverse self-locking tapping screw of bidirectional helical

Technical field

The utility model relates to threaded fastener, the reverse self-locking tapping screw of specifically a kind of bidirectional helical.

Background technique

At present, the fastening screw trip bolt that uses in machinery is with the rotation direction screw, in use bears double-direction twist moment, screw extraction occurs, hugs phenomenons such as button because of overload often.I am at Chinese patent ZL

In a kind of reverse balance positioning screwn is disclosed, it can be in use balance even the double-direction twist moment that bears of offset screw mutually fully, mechanism is worked safely and reliably.I am devoted to again this screw is developed as and can only advances in development thereafter, and the tapping screw type of the reverse self-locking that can not retreat is for the tapping screw fastening piece increases new kind.

Summary of the invention

The purpose of this utility model is exploitation tapping screw fastening piece new varieties, provide a kind of bidirectional helical reverse self-locking tapping screw, non-rotary self tapping mode connects left and right two links with propelling for it, advance quick smoothly, revolve and move back self-locking, stop the hidden danger that falls back and bring because of screw loosening, avoid screw to hug buckleing and the phenomenon that fractures takes place, improve the machinery safety reliability.

The purpose of this utility model is achieved in that

The reverse self-locking tapping screw of a kind of bidirectional helical, its screw flight is divided into two sections, and one section is right-handed thread, and one section is left-handed thread, and there is the bar head of diameter less than the core diameter of thread at the screw rod two ends, it is characterized in that:

In the axial cross section of this left and right hand thread, separated time m and inclined-plane, teeth both sides form two flank of tooth half-angle α and β in the teeth vertical with screw axis, greater than the flank of tooth half-angle β of screw rod direction of propulsion dorsad, the path circular arc is arranged at the top of these screw thread teeth towards the flank of tooth half-angle α of screw rod direction of propulsion;

The flank of tooth half-angle α of this left and right hand thread, β position are inverted.

The value of described inclined-plane half-angle α is 30 °, and the value of described inclined-plane half-angle β is between 5～20 °.

The shape of described screw thread teeth also comprises: at the top of the flank of tooth half-angle β of screw rod direction of propulsion dorsad the one short straight flange that overlaps with middle separated time m is arranged.

Teeth pitch, a number of described right-handed thread and left-handed thread are identical, and profile of tooth identical but flank of tooth half-angle α, β are inverted.

The middle compartment that optical path can be arranged between the right-handed thread of described screw rod and left-handed thread.

The utility model has following actively useful effect:

This product structure is simple, non-rotary self tapping mode connects left and right two couplings with propelling for it, can the left and right two ends of balance screw moment of torsion, screw is easily being worked under the state, its special asymmetric profile of tooth makes and advances smoothly fast, revolves and moves back self-locking, stops the hidden danger that falls back and bring because of screw loosening, avoid screw to hug buckleing and the phenomenon that fractures takes place, thereby improve the safety reliability of machinery.

Description of drawings

Fig. 1 is the utility model one embodiment's a structural representation;

Fig. 2 is a kind of embodiment in profile of tooth cross section among Fig. 1;

The same Fig. 2 of Fig. 3 is another embodiment;

Fig. 4 is the utility model one embodiment's a user mode schematic representation.

Accompanying drawing number:

1. screw

101. right-handed thread section 102. left-handed thread section 103. end bar heads

104. middle compartment

2. meet screw rod direction of propulsion face 3. back of the body screw rod direction of propulsion faces 4. short straight flanges

5. fastener 6. fasteners

M. separated time in vertical with the screw axis teeth

α. (meeting) flank of tooth half-angle β. (back of the body) flank of tooth half-angle--→. the screw thread direction of propulsion

Specific embodiment

Please refer to Fig. 1, Fig. 4, the utility model is the reverse self-locking tapping screw of a kind of bidirectional helical, and its screw flight is divided into two sections, and one section is that 101, one sections of right-handed threads are left-handed thread 102, and there is the bar head 103 of diameter less than the core diameter of thread at the screw rod two ends;

Please refer to Fig. 2, in the axial cross section of this left and right hand thread, separated time m and inclined-plane, teeth both

sides

2 and 3 form two flank of tooth half-angle α and β in the teeth vertical with screw axis, greater than the flank of tooth half-angle β of screw rod direction of propulsion dorsad, the path circular arc is arranged at the top of these screw thread teeth towards the flank of tooth half-angle α of screw rod direction of propulsion;

Please refer to Fig. 3, the shape of described screw thread teeth also comprises: at the top of the flank of tooth half-angle β of screw rod direction of propulsion dorsad the one short straight flange 4 that overlaps with middle separated time m is arranged.

During enforcement, teeth pitch, a number of described right-handed thread and left-handed thread are identical, and profile of tooth identical but flank of tooth half-angle α, β are inverted.

The middle compartment 104 that optical path can be arranged between the right-handed thread of described screw rod and left-handed thread.

Claims

1. reverse self-locking tapping screw of bidirectional helical, its screw flight is divided into two sections, and one section is right-handed thread, and one section is left-handed thread, and there is the bar head of diameter less than the core diameter of thread at the screw rod two ends, it is characterized in that:

2. the reverse self-locking tapping screw of bidirectional helical as claimed in claim 1 is characterized in that: the value of described inclined-plane half-angle α is 30 °, and the value of described inclined-plane half-angle β is between 5～20 °.

3. the reverse self-locking tapping screw of bidirectional helical as claimed in claim 1, it is characterized in that: the shape of described screw thread teeth also comprises: at the top of the flank of tooth half-angle β of screw rod direction of propulsion dorsad the one short straight flange that overlaps with middle separated time m is arranged.

4. the reverse self-locking tapping screw of bidirectional helical as claimed in claim 1 is characterized in that: teeth pitch, a number of described right-handed thread and left-handed thread are identical, and profile of tooth identical but flank of tooth half-angle α, β are inverted.

5. the reverse self-locking tapping screw of bidirectional helical as claimed in claim 1 is characterized in that: the middle compartment that optical path can be arranged between the right-handed thread of described screw rod and left-handed thread.