RU2354861C1 - Zemlyakov's locking bolt for fastening in blind hole - Google Patents

Abstract

FIELD: machine building.

SUBSTANCE: locking bolt for fastening in blind hole is made from main bolt with standard hexahedral head, treaded rod with main thread on external cylindrical surface, through axial hole with additional thread. Additional thread is made from butt side of main bolt threaded rod on length not longer that diametre of threaded rod of additional bolt, on which locking threaded element is installed, made in form of said additional bolt with hexahedral head, whose threaded rod is longer than threaded rod of main bolt. Between head of additional bolt and flat surface of main bolt head on threaded rod of additional bolt spring washer is installed and tightened. Sides of additional bolt head are enveloped by sides of hexahedral hole of polyhedral washer, one side of which is tightened to butt flat surface of hexahedral head of main bolt. Diametral size between interfacial angles of polyhedral washer and diametral size between interfacial angles of hexahedral head of main bolt are equal. Operational thickness of polyhedral washer is greater that spring washer thickness. Above sides of main bolt head and sides of polyhedral washer thermocontractable tube or cap is installed and rigidly tightened.

EFFECT: increasing reliability of locking.

2 cl, 5 dwg

Description

The invention relates to mechanical engineering and can be used to perform threaded locking of various parts and assemblies in machines and apparatuses, in building structures and in other equipment operating in conditions of strong and long-term vibration, for example, in rail-sleeper structures, in locomotive equipment, in aviation equipment, in automobile and tractor, in shipbuilding and in another, for example, in constructions assembled in space orbits.

Known threaded element for fastening in a blind hole, containing a threaded rod with a through threaded hole and a head with a cavity, a locking screw installed in the threaded hole of the rod, and a fixing element placed in the head with emphasis on the cavity walls and in the upper end of the screw (option 1 and 2) [1].

A disadvantage of the known threaded elements for fastening in a blind hole is that the additional thread of the locking screw is made along its entire length, which increases the moment of resistance during its installation and dismantling with a screwdriver, in addition, the execution of a screw with a diametrical slot for a screwdriver in the end of the threaded part significantly complicates obtaining a sufficiently large torque to ensure that the screw stops in the bottom of the blind hole and at the same time creates sufficient interference in the turns of the main thread, which in most cases Uchaev spacing larger than that of the locking screw. In addition, in the first embodiment, the screw stop is fixed by a leaf spring, which does not protect the screw from turning during vibration even by a small angle, which can weaken the created interference in the coils of the main thread. In the second embodiment, the main disadvantage is the selective selection of the fixing rods by diameter, which can be different for different screw tightening forces, and this makes installation very difficult.

The closest in technical essence to the claimed invention is a “Bolt for fastening in a blind hole” [2], containing a head with six faces on a key, a threaded rod with a main thread on the outer cylindrical surface, a through axial hole with an additional thread into which the locking screw is screwed a screw having a hexagonal head in which a plastically deformable fixing element is transversely mounted, located both in the transverse grooves of the bolt head and between the head of the threaded element and the bolt head, a spring washer is mounted on the threaded element, and the threaded rod is screwed with the main thread to the bottom of the blind hole in the housing, while the end of the locking screw is pressed into the conical part of the bottom of the blind hole.

The disadvantage of this device is that the bolt itself is a rather complex device, because It has a specially made head with an internal cavity and transverse grooves above the faces, and to fix the created interference in the coils of the main thread, again, a complex locking screw device with a high faceted head with a transverse hole between the two faces is used. In addition, during operation, the cavity of the bolt head is clogged with oil and dust, which are difficult to remove, which reduces the possibility of the device working in machines with high sanitary and hygienic requirements. In addition, the installation and dismantling of the device is complicated.

The problem to which the invention is directed is to use standard parts in the manufacture of the device, simplify installation and dismantling of the device, increase the reliability of the locking process and ensure high sanitary and hygienic conditions during operation, and meet the requirements for the possibility of selective selection of fixing elements.

This is achieved by the fact that the locking bolt for fastening in a blind hole made of a main bolt with a standard hexagonal head, a threaded rod with a main thread on the outer cylindrical surface, an axial through hole with an additional thread, while the additional thread is made from the end face of the threaded rod of the main a bolt with a length λ of not more than the diameter of the threaded rod of the additional bolt, along which a locking threaded element is installed, made in the form of the mentioned additional a hex head, the threaded rod of which is longer than the threaded rod of the main bolt, in addition, a spring washer is installed and preloaded between the head of the additional bolt and the flat surface of the head of the main bolt, and the faces of the additional bolt are covered by the faces of the hexagonal hole of the polyhedral washer , one side of which is pressed against the end flat surface of the hexagonal head of the main bolt, the diametric size µ between the interhedral edges is many the faceted washer and the diametrical size between the facetted angles of the hexagonal head of the main bolt are the same, the working thickness ξ of the multi-faceted washer is greater than the thickness of the spring washer, and a heat-shrinkable tube or cap is installed and tightly pressed over the faces of the main bolt and the faces of the polyhedral washer. The working thickness ξ of the polyhedral washer can exceed the thickness of the spring washer by 10-100% of the thickness of the spring washer.

The invention is illustrated by drawings, where figure 1 shows a drawing with an axial section of a General view of a bolt installed in a blind hole of the housing. Figure 2 shows a section aa from figure 1. Figure 3 shows a multifaceted, and in a particular case, hexagonal, washer. Figure 4 shows a section bB of figure 3. Figure 5 shows a multifaceted washer with the number of faces greater than six.

The locking bolt device for fastening in a blind hole consists of a main bolt with a standard hexagonal head 1, a threaded rod 2 with a main thread 3 on the outer cylindrical surface. The main bolt contains a through axial hole 4 with an additional thread 5, while the additional thread 5 is made from the end face 6 of the threaded rod 2 of the main bolt at a length λ. The length of the additional thread 5 can be no more than the diameter of the threaded rod 7 of the additional bolt 8. By the thread 5, the additional bolt 8 having a hex head 9 is installed in the rod 2 of the main bolt. The threaded rod 7 is longer than the threaded rod 2 of the main bolt. Between the head 9 of the additional bolt 8 and the flat surface 10 of the head 1 of the main bolt, a spring washer 11 is installed and preloaded on the threaded rod 7 of the additional bolt 8, while the faces of the head of the additional bolt 8 are covered by the faces 12 of the hexagonal hole 13 of the polyhedral washer 14, one side 15 of which is preloaded to the end flat surface 10 of the hex head 1 of the main bolt. The diametrical size µ between the interhedral edges of the polyhedral washer 14 and the diametric size between the interhedral edges of the hexagonal head 1 of the main bolt are the same. The working thickness ξ of the multi-faceted washer 14 is greater than the thickness of the spring washer 11, and the heat-shrinkable tube 15 or cap is mounted and rigidly pressed over the faces of the head 1 of the main bolt and the faces of the multi-faceted washer 14.

The device operates as follows.

Before fastening the bolt in the blind hole, the bolt as an assembly unit must be assembled from the following separate parts: a main bolt having a head 1 and a threaded rod 2 with a main thread 3, and an additional bolt 8, on which a spring washer 11 is put on the threaded rod 7, and Further, the threaded rod 7 is inserted into the through hole 4 and screwed onto the additional thread 5 until the spring washer 11 touches the flat surface 10 of the hexagonal head 1. And in this state, the device is stored in the finished goods warehouse. If necessary, screw such an assembly unit into the blind threaded hole of the housing 16, while clamping the part 17 through the spring washer 18 and the usual washer 19, worn on the rod 2. The end 6 of the threaded rod 2 of the main bolt may not even abut against the conical surface 20 , it is enough that the end face of the threaded rod 7 of the additional bolt 8 rests on the top 21 or on the conical surface 20 of the housing 16, since after that the additional bolt 8 continues to be screwed by one and a half turns until the spring is completely compressed washers 11. Then, on the face of the hexagon head 9 of the additional bolt 8, a polyhedral washer 14 is installed with faces 12 of the hexagonal hole 13. After that, heat shrink tube 15 or cap is installed over the faces of the head 1 of the main bolt and the faces 22 of the polyhedral washer 14 and heat shrink is started uniformly around the entire perimeter tube 15 or cap until tight shrinkage of the tube 15 or cap is on the verge of the head 1 of the main bolt and the verge 22 of the polyhedral washer 14.

This technology provides a “mechanical memory” of the created interference value in the turns of the main thread 3 of the rod 2 and the housing 16. The necessary interference is created when the additional bolt 8 is pulled, providing high reliability of the locking of the main bolt in the housing 16 and the operation of the device in conditions of strong and long-term vibration.

The usefulness of the invention lies in the fact that such a bolt device for mounting in a blind hole allows you to quickly install the bolt at any location of its threaded rod relative to the horizontal, because there are no parts that may fall out or which must be collected during the installation process in a selective way. In addition, for mounting and disassembling the bolt, only two sizes of wrenches are required - a wrench for head 1 and a wrench for head 9, which allow for a large moment both during installation and during dismantling. Installation is carried out in just five operations: 1 - screw in the hexagonal head 1 of the main bolt with a key into the blind hole until the part 17 is pressed; 2 - screw in the hex head 9 of the additional bolt 8 with a key until it stops into the conical surface 20 or the top 21 of the blind hole; 3 - install the washer 14 on the head 9; 4 - install heat shrink tube 15 or cap over the head 1 and washer 14; 5 - warm up tube 15 or cap (heat shrink).

Information sources

1 Russian Patent No. 1164477.

2. Patent of Russia No. 2154203.

Claims (2)

1. A locking bolt for fastening in a blind hole made of a main bolt with a standard hex head, a threaded rod with a main thread on the outer cylindrical surface, a through axial hole with an additional thread, characterized in that the additional thread is made from the end face of the threaded rod of the main bolt on a length λ of not more than the diameter of the threaded rod of the additional bolt, along which a locking threaded element is installed, made in the form of the said additional bolt with a tiger's head, the threaded rod of which is longer than the threaded rod of the main bolt, in addition, between the head of the additional bolt and the flat surface of the head of the main bolt, a spring washer is installed and preloaded on the threaded rod, while the faces of the head of the additional bolt are covered by the faces of the hexagonal hole of the polyhedral washer, one the side of which is pressed to the end flat surface of the hexagonal head of the main bolt, the diametric size µ between the polyhedral angles the washers and the diametrical size between the interhedral angles of the hexagonal head of the main bolt are the same, the working thickness ξ of the polyhedral washer is greater than the thickness of the spring washer, and a heat-shrinkable tube or cap is installed and firmly pressed over the faces of the main bolt and the faces of the polyhedral washer. 2. A locking bolt for fastening in a blind hole according to claim 1, characterized in that the working thickness ξ of the multifaceted washer exceeds the thickness of the spring washer by 10-100% of the thickness of the spring washer.

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