RU221942U1 - Spring for connecting elements of wooden building structures - Google Patents

Abstract

The utility model relates to the field of wooden house construction. The spring for the connection unit of elements of wooden building structures is made of continuous wire, having a circular cross-section, with turns that uniformly increase relative to the longitudinal axis of symmetry of the spring and includes an uppermost turn for resting on the head of the fastening element and an outermost lower turn for resting on the surface building structure. The outermost coil is made with an outer diameter smaller than the inner diameter of the next coil to accommodate the lowermost coil in the cavity of the coil following it when the spring is compressed at the moment of resting on the surface of the building structure. The coil of the spring following the outermost coil is pressed against this outermost coil. At the uppermost coil of the conical spring, the outward portion of the surface of the coil is cut to obtain a flat surface perpendicular to the longitudinal axis of the conical spring. And in the two lower turns, when a coil of smaller diameter is located in the cavity of a coil of larger diameter, the outward-facing parts of the surface of the coils are cut to obtain flat surfaces, while these surfaces of the two lower coils in the compressed state of the spring are located in a common plane perpendicular to the longitudinal axis of the conical spring. 5 ill.

Description

The utility model relates to the field of wooden house construction and can be used for assembling structures made of wood (timber, logs) and other wooden building materials that have the possibility of slight deformation, linear and spatial displacements and changes in volume/density depending on time and environmental conditions. In particular, the claimed solution is used for assembling wooden houses, buildings and structures made of timber and rounded logs, as well as for assembling frame houses.

Known from the prior art is a shaped compression spring of a conical shape, intended for connecting elements of wooden structures, and which is made of continuous wire, having a circular cross-section, with turns uniformly increasing relative to the longitudinal axis of symmetry of the spring, and includes upper and lower support turns , wherein the lower support coil consists of two coils, one of which has an outer diameter larger than the upper support coil, and the second is made narrower and is located in the unloaded state of the spring relative to the first lower support coil in such a way that its upper horizontal plane is higher the lower horizontal plane of the first turn, while the size of the outer diameter of the second lower support turn is selected in such a way that in the loaded state of the spring it is designed to be freely placed inside the first lower support turn (RU 211972, F16B31/04, published 06/30/2022 ).

The spring is made of carbon spring wires of round section 3÷7 mm, grades A1, B2 and alloy steel grades 60S2A, 51HFA.

This solution was adopted as a prototype.

This conical-shaped spring is used in the fastening unit to reduce the formation of gaps between the fastened wooden structural elements that arise due to shrinkage and linear deformations. However, this spring design has an inherent disadvantage, expressed in the fact that placing such a spring on a screw or bolt often leads to loss of stability fastening unit due to misalignment of the spring relative to the longitudinal axis of the self-tapping screw. When screwing in a self-tapping screw/screw, the spring takes the position that makes it stable in relation to the wood, and not to the longitudinal axis of the self-tapping screw/bolt rod. As a result, the self-tapping screw/bolt may be screwed in skewed, and the spring will be positioned not in relation to the axis of the screw, but to the site on the wood. This leads to misalignment of the compressed spring relative to the self-tapping screw/screw. And when the spring is skewed, a bending moment is formed that acts on the self-tapping screw through its head. When the wood dries and the degree of compression of the self-tapping screw decreases, this moment will turn the rod out, since on its threaded turns, when the forces are distributed in the coordinate system, one of them will be directed along the rod towards the head, and the other towards the wall of the hole in the tree. This leads to loosening of the tightening.

When using this type of fastening unit, it is important to solve the problem of ensuring strict coincidence of the longitudinal axis of the compressed conical spring at the moment of its support on the tree with the longitudinal axis of the self-tapping screw/bolt rod to eliminate the occurrence of a bending moment.

The distortion of the spring sitting on the rod of the self-tapping screw/screw is a consequence of its support on the head and on the bottom of the blind hole in the wood. The spring coils are made of a circular cross-section, both the upper one, which rests against the base of the screw head, and the two lower coils, used to rest the bottom of the blind hole on the platform. The turns are arranged at an angular angle in a spiral. The upper turn is also made in the shape of a fragment of a spiral and therefore, when resting on the base of the head, it contacts this base only for part of its length. Upon contact, the upper coil tries to balance and form a support along the entire length of the coil, but this is possible if the spring tilts at an angle equal to the angle of elevation of the coils in the spring. And with further compression, the lower turns rest against the bottom of the hole in turn: first, the outermost turn of a smaller diameter, which receives a stop in the place that is the result of the skew of the upper turn, and then a turn of a larger diameter, which is laid around the outermost turn in the same place. Where is this small bottom turn located? That is, during compression, the longitudinal axis of the conical spring will be shifted at an angle relative to the longitudinal axis of the self-tapping screw/screw rod. And this leads to the appearance of a bending moment on the rod.

This utility model is aimed at achieving a technical result consisting in improving the performance qualities of a conical spring when used in a fastening unit by eliminating angular displacements of the longitudinal axis of this spring relative to the longitudinal axis of the fastening element screwed into wood.

The specified technical result is achieved by the fact that the spring for the connection unit of elements of wooden building structures is made of continuous wire, having a circular cross-section, with turns uniformly increasing relative to the longitudinal axis of symmetry of the spring, and includes the outermost upper turn for support in the head of the fastening element and the outermost lower turn for resting on the surface of the building structure, while the outermost turn is made in outer diameter smaller than the inner diameter of the next turn to accommodate the outermost lower turn in the cavity of the next turn when the spring is compressed at the moment of resting on the surface of the building structure, the spring coil following the uppermost coil is pressed against this outermost coil; at the uppermost coil of the conical spring, the outward portion of the surface of the coil is cut to obtain a flat surface perpendicular to the longitudinal axis of the conical spring; in the unloaded state of the conical spring, the lowermost coil is located at a distance from the next coil of larger diameter, and for the two lower coils, when the coil of smaller diameter is located in the cavity of the coil of larger diameter, the outward parts of the surface of the coils are cut to obtain flat surfaces, while these surfaces of the two lower coils in the compressed state of the spring are located in a common plane perpendicular to longitudinal axis of the conical spring.

The coil of the spring following the outermost upper coil can be made with a diameter equal to the diameter of this outermost upper coil.

The technical result is also achieved by applying a zinc coating to the spring. The spring can be made of 65Mn high carbon steel.

These features are interrelated and are essential to form a stable set of essential features sufficient to obtain the required technical result.

This utility model is illustrated by a specific example of execution, which, however, is not the only possible one, but clearly demonstrates the possibility of achieving the required technical result.

In fig. 1 - general view of the fastening unit with a conical spring;

in fig. 2 - general view of the conical spring in an uncompressed state;

in fig. 3 - longitudinal section of the spring according to FIG. 2;

in fig. 4 - bottom view of the spring from FIG. 2;

in fig. 5 is a top view of the spring from FIG. 2.

According to this utility model, the design of a conical spring for a fastening unit for connecting elements of wooden building structures, in particular, in wooden house construction, is considered.

Thanks to the constant pressing of one wooden element to another during shrinkage/shrinkage, even shrinkage of the entire tree is ensured, and cold bridges in the structure are reduced. The aesthetic appearance of the structure also improves after shrinkage of the house or structures during shrinkage, and the efficiency of heating the house increases by reducing the formation of cold bridges between wooden structures.

The fastening unit consists of two interconnected elements: a conical spring 1 and a cylindrical rod 2 with a head 3 that follows the shape of a self-tapping screw (Fig. 1). The self-tapping screw/screw is responsible for the clamping capacity, namely, wood tends to expand, swell, and dry out, depending on weather conditions. The length of the rod 2 consists of an upper part located on the side of the head 2 and a conical tip 4 with a screw thread 5 in the lower part on the free end side. A conical spring 1 is strung on the upper part of the cylindrical rod, resting with the uppermost turn 6 against the base of the rod head.

The conical spring has two upper coils (positions 6 and 7) that are compressed together in order to elastically grip the rod when resting on the flat base of the head. The two upper turns can be made of the same diameter for more reliable fixation on the rod without angular displacement. In this case, the outermost coil 6 of the conical spring is aligned to obtain a flat surface 8 perpendicular to the longitudinal axes of the conical spring and the rod.

Alignment involves grinding (cutting off the outward-facing part of the surface of the coil) part of the coil and obtaining a flat surface 8. This allows you to elastically put the spring on the rod and press the upper coil to the flat base of the head of the rod. The flat base of the rod head in relation to the flat surface 8 of the coil is the reference surface that determines the positioning of the longitudinal axis of the spring relative to the longitudinal axis of the rod. When assembled, the fastening unit does not fall apart, and in this one-piece form it goes into operational use.

And the outermost coil 9 of the conical spring is made with a diameter smaller than the diameter of the coil 10 following it and can be placed in its space when the spring is compressed. In this case, the outermost coil 9 of the conical spring is also aligned to obtain a flat surface 11 perpendicular to the longitudinal axes of the conical spring. Following the coil 9 of a smaller diameter, the coil 10 of a larger diameter is also aligned to obtain a flat surface 12 perpendicular to the longitudinal axes of the conical spring. That is, in the two lower coils 9 and 10, when a coil of smaller diameter is located in the cavity of a coil of larger diameter, when the spring is compressed, the outward-facing parts of the surface of the coils are cut off to obtain flat surfaces. In this case, these surfaces 11 and 12 of the two lower turns 9 and 10 in the compressed state of the spring are located in a common plane (see Fig. 3), perpendicular to the longitudinal axis of the conical spring.

The zinc coating of the spring ensures a long service life (tested in sea water, the service life of the spring is 1500 hours).

The spring is made of high carbon steel. During the winter period, a wooden house goes through 40-50 cycles of frost changes. On average, per year, a wooden house can change its cycles up to 200-250 times. Because of this, it is advisable to use special steel in the spring material. In most cases, similar products use ordinary steel, which cannot withstand such a load; the spring either collapses, losing its properties by 30-40%, or becomes completely unusable. For example, 65Mn high carbon steel can be used, mainly used in making various small flat springs, round springs, clock mechanisms, etc. It can also be used in making shock absorbers, clutch tongues, brake springs, spring rings, valve springs . Moreover, the frequency of opening and closing of each valve (intake and exhaust) of cars in one minute is at least 3000 times.

Below is the chemical composition and properties of 65Mn high carbon steel based on thermal analysis.

Chemical composition of 65Mn steel, % Standard Grade WITH Si Mn P, ≤ C, ≤ Kr, ≤ Ni,≤ Cu,≤ GB/T 1222 65Mn 0.62-0.70 0.17-0.37 0.90-1.20 0.030 0.030 0.25 0.35 0.25

Density: 7.85 g/cm3

Mechanical properties Standard Grade Tensile strength, MPa, ≥ Yield strength, MPa, ≥ Elongation, %, ≥ Area reduction, %, ≥ Brinell hardness, HBW, ≤ GB/T 1222 65Mn 980 785 8.0 thirty 302

When the rod is screwed in, the lower turns 9 and 10 sit at the bottom of the blind hole in the wooden product, and the spring begins to compress. When compressed, the lowermost turn 9 tightly flat surface 11 rests on the bottom of the hole (the position of the lower turn 9 is determined by the contact of the upper turn 6 with the base of the head). And the lower coil 10 that follows it sags and is placed at the bottom of the blind hole around coil 9. Thus, a support for the compressed spring, developed in area, is formed. In this case, the compression and deformation of the spring coils occur strictly along the longitudinal axis of the rod, which eliminates the skewing of the rod itself and the formation of a bending moment. In this case, the spring is clearly positioned at the bottom of the blind hole, even if there are irregularities on this bottom. This is explained by the fact that all turns are interconnected and a change in the deformation trajectory of one turn is compensated by the action of other turns, in which the deformed turn returns to the correct position.

With the spring fastened in this way and its design, the spring only works to press the fastened wooden products against each other.

This utility model is industrially applicable and allows for guaranteed reliable and long-term fastening of wooden structures due to the precise positioning of the spring in the tree and the constant pressing of the fastened products to each other, regardless of the condition of the tree itself. The utility model makes it possible to improve the performance properties of a conical spring when used in a fastening unit by eliminating angular displacements of the longitudinal axis of this spring relative to the longitudinal axis of the fastening element screwed into wood.

Claims (4)

1. A spring for a unit for connecting elements of wooden building structures, characterized in that it is made of continuous wire, having a circular cross-section, with turns that uniformly increase relative to the longitudinal axis of symmetry of the spring and includes an uppermost turn for support in the head of the fastening element and an extreme lower turn for resting on the surface of a building structure, wherein the extreme lower turn is made in outer diameter smaller than the internal diameter of the next turn to accommodate the outermost lower turn in the cavity of the next turn when the spring is compressed at the moment of resting on the surface of a building structure, characterized in that that the coil of the spring following the outermost coil is pressed against this outermost coil, at the outermost coil of the conical spring the outward-facing part of the surface of the coil is cut to obtain a flat surface perpendicular to the longitudinal axis of the conical spring, in the unloaded state of the conical spring the outermost coil is located on distance from the next coil of larger diameter, and for the two lower coils, when a coil of smaller diameter is located in the cavity of a coil of larger diameter, the outward parts of the surface of the coils are cut to obtain flat surfaces, while these surfaces of the two lower coils in the compressed state of the spring are located in a common plane , perpendicular to the longitudinal axis of the conical spring. 2. The spring according to claim 1, characterized in that the spring coil following the uppermost coil has a diameter equal to the diameter of this uppermost coil. 3. Spring according to claim 1, characterized in that it has a zinc coating. 4. The spring according to claim 1, characterized in that it is made of high-carbon steel grade 65Mn.