CS199130B1 - Union nut for connection of pressure pipeline,especially injection pipes of internal combustion engines - Google Patents

Description

The object of the invention is a fitting for connecting pressure pipes, in particular injection pipes of internal combustion engines, to prevent the pipes from cracking at the point of their connection to the injection pump or injector nozzle while ensuring perfect tightness.

The injection tubes of the internal combustion engine are subjected to high fuel pressure and vibrations while the engine is running. If the injection pipe is connected to the injection pump or injector nozzle according to the current standards, the axes of the injection pipe end and the nozzle are misaligned after tightening the union nut, resulting in an unsuitable shape of the contact pressure and damage to the material during ramming cracking of the injection pipes while the engine is running.

To remove the bursting of the injection pipes, there are known fittings for connecting a pressure pipe consisting of an injection pipe end, a sliding nut and a neck, in which the inner contact surface of the sliding nut is conical and the outer bearing surface of the pipe end is frustoconical or hemisphere. These endings reduce the notch effect of passing the cylindrical portion of the injection tube into its support surface and lessen the risk of breakage of the end surface of the nozzle by upsetting.

199 130

However, the described pressure pipe connections have the following disadvantages.

For a terminal with an external support surface in the form of a portion of the hemisphere surface, when tightening the union nut, the throat transmits the thrust force between the union nut and the end support surface at a point that is substantially closer to the axis of the terminal. the effect of the pipe and throat axes and the consequent deterioration in the tightness of the pressure connection. In the case of a terminal and a truncated conical contact surface with an apex angle in the range of 20 ° to 55 ° the disadvantage is also a deterioration of the compensating effect of the terminal at the same size of this angle with the angle of the inner conical pressing surface of the nut. axially, which is economically disadvantageous.

The above-mentioned disadvantages are overcome by the embodiment of the pressure pipe connection according to the invention, which is characterized in that the conical surface of the injection pipe end has an apex angle 4 ', and the inner contact surface of the union nut has a conical surface with apex angle " , wherein for both apex angles, the equation is that = ₂ +?. where λ = 0 ° 30 ° to 12 ° and wherein the angle is 55 ° ° _{2 2}

<70 °.

DESCRIPTION OF THE PREFERRED EMBODIMENT The pressure pipe connection according to the invention is shown in longitudinal section in the drawing.

The fitting consists of the actual injection tube 1 on which the sliding nut 2 is mounted. The end of the injection tube 1 has the shape of the outer conical surface 2 at the apex angle on the side adjacent to the transfer nut 6 and the outer conical surface at the apex angle χ. The transition of the cylindrical part of the tube 1 to the conical surface 2 is formed by a rounding ₂ . The neck 8 is provided with an inner sealing conical surface 2 with an apex angle <

For optimum compensation effect with a good tightness of the connections must be satisfied, provided that · ² · ° * »P ^^ EMZ 55 <

<70 °.

The advantages of the connection fitting are that the optimum possible compensatory effect of the pipe end axis 1 and the pipe axis _{2 of the} neck 8 when tightening the union nut 6 is ensured, since the transmission of force at the furthest common point of the two conical surfaces is guaranteed. and 2 from the osyχ axis of pipe end 1.

The conical surface 2 of the pipe end 2 is gradually transferred to its cylindrical part 1 relative to the end e of the hemispherical shape of the surface of the surface, which also contributes to an increase in the fatigue limit.

Claims (1)

PURPOSE OF THE INVENTION Fittings for the connection of pressure pipes, in particular injection pipes in internal combustion engines, consisting of the pipe itself, of a sleeve thereon and of a counterpart, the end of the pipe being shaped like a terminal formed by two coaxial conical surfaces between which a cylindrical surface is formed. the union nuts serve to connect and press the sealing cone of the injection pipe end into the cone of the injection pump or injector neck, characterized in that the conical surface (2) of the injection pipe end (1) has an apex angle (and the inner pressing surface (7) 6) is a conical surface with an apex angle (? / 2 ^ Ρ ^ Ί · ⁵ ® ⁸¹ ® For ° La apex angles following relationship applies: = (^ 2 ⁺ <£) ^»kd ® £ - ~ 0 30 ^a to 12 And wherein for the angle (? ₂ ), the condition is 55 ° <<70 °.