SU1677382A1 - Adjustable fastener - Google Patents

Abstract

The invention relates to mechanical engineering. The purpose of the invention is to simplify the design of the fastening assembly. The assembly contains a panel with a hole, on opposite sides of the cathode there are two supports with two side posts each. The middle parts of the supports are made flat and have 2 holes for the fastener. One of the legs of each support is inclined from the normal to the panel surface by an angle larger than the self-locking angle. The inclined legs of the supports are directed opposite to each other. When tightening the nuts on the threaded bushing, which is pre-installed with the necessary inclination to the panel, the inclined flange of the panel bends, slipping over the panel, under the action of the pressure force of the nut end. The nuts are tightened until the bearing surface of the washers is set parallel to the ends of the nuts, ensuring that the threaded sleeve is fixed at an angle to the panel. 1 hp f-ly, 2 ill.

Description

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The invention relates to mechanical engineering and can be used, for example, for fastening reinforcement of hydraulic systems with ensuring the required alignment in pipe joints.

The purpose of the invention is to simplify the design.

FIG. 1 shows an adjustable mounting unit, a general view; FIG. 2 is a diagram of the forces acting on the washer when the nut is tightened.

The adjustable fastening assembly comprises a panel 1 (FIG. 1) with a hole, a threaded bushing (anvil) 2, washers with shoulders 3 facing the panel, and nuts 4 fixing the bushing axially with axial adjustment. .

As a threaded sleeve may be an anchor, to which the pipes 5 are connected.

The threaded sleeve is fixed to the panel as follows.

The threaded sleeve 2 with the washers 3 put on it and the nuts 4 loosely fitted is installed in the opening of the panel 1. By pre-installing the pipeline to be mounted or the technological adaptation replacing it, the sleeve 2 sets the inclination necessary to ensure alignment with the element to be joined. The washers 3 are rotated around the axis of the sleeve so that the inclined shoulder faces the narrow part of the gaps between the nuts 4 and the panel 1. When the nuts are tightened, the inclined shoulder of the washer is bent over, sliding along the panel 1. The damping is done while the washer is tilted as a result of the deformation of the inclined collar, does not stand with its bearing surface parallel to the nut. After this, the washers are clung to

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the weld panels 6 and the nuts A are finally tightened.

The magnitude of the initial inclination of the deformable collar of the washer 3, which ensures its sliding along the plane of the panel 1 when tightening the nut 4, can be determined by considering the scheme of forces acting on the collar of the washer shown in FIG. 2, where P is the pressure force of the nut on the bearing surface of the washer; R is the reaction of the support surface of the panel; f is the coefficient of friction of the material of the washer on the panel material; a, b - linear dimensions defining the slope of the washer collar; a is the angle between the washer shoulder and the normal to the panel surface at the point of contact with its inclined shoulder.

Considering for simplicity the joint of the collar with the bearing surface of the hinge washer (assuming conventionally the bending rigidity of the collar in the transition section is zero), we write the ratio of the moments of forces at which the collar turns in the direction of increasing the angle a

R-a R-f-b, from where

| - tunwiga f.

Considering that the angle, the tangent of which is equal to the friction coefficient, is called the friction angle, it can be said that the necessary condition for the washer collar to deform under the force of the nut pressure on the washer is the angle of the collar to the normal to the panel at the point of contact with its collar larger than friction, or self-locking angle.

For example, assuming that the friction coefficient for steel parts is equal to

0.2, .. 0.3, we find that the inclination of the collar to the normal to the panel at the point of contact should be at least 11 ... 17 °, or the angle between the inclined shoulder and the bearing surface of the washer should be at least 101 ... 107 °.

Use in an adjustable mounting unit as an element that provides adjustment, stamped sheet metal parts of simple form (washers) instead of a hinged pair with curvilinear

surfaces (sphere, cone) reduces the labor intensity of manufacture and the mass of the structure.

Claims (1)

1. Adjustable fastening assembly containing a panel with a hole, a support mounted on it with two side posts facing the panel with a hole for the fastening element in the middle part, and a nut mounted on the support that, in order to simplify the design One of the racks is inclined from the normal (from the panel surface at an angle greater than the self-locking angle, and the middle part of the support is made flat. 2, a unit according to claim 1, characterized in that the supports are arranged on both sides of the panel with the uprights one towards the other, and the inclined supports of the supports are directed to opposite sides of one another. 5x figure 1 2