SU1171265A1 - Method of interference-fit joining of articles - Google Patents

Abstract

METHOD OF CONNECTING ITEMS WITH TENSION by pressing a slider to press one of the parts into another and disrupting the resulting connection by longitudinal relative movement of parts, characterized in that, in order to improve the strength of the connection, breakdowns are carried out periodically during the pressing process by transferring force from the press slider to the pressed part through elastic coupling, and the movement of the slider is conducted at a speed of 510–5010 m / s. (L .bNXV4 vV4 FIG. 1

Description

The invention relates to the field of mechanical assembly production, in particular, to methods for connecting parts with interference.

The purpose of the invention is to increase the strength of the joint by increasing the mechanical component of the friction force between the mating surfaces.

In FIG. 1 shows the process of connecting parts; in FIG. 2 - node I 'θ in FIG. 1.

The method is as follows.

After the orientation of the connected parts 1 and 2 (Fig. 1). between them and the 15th punch of the press 3, an elastic element is installed, for example, a spring 4 and a press-in is made with a speed of movement of the punch 5 Ί 0-50'10 m / s.

During the movement of the punch npec ^ ZO ca, the spring is compressed by the force P and the system accumulates mechanical energy without the relative movement of the parts to be joined. Moreover, in the contact zone, the surface layers 25 are deformed, forming a wave 5 (Fig. 2). When the compression energy is sufficient to overcome the rest friction force of the parts, the latter move with greater speed relative to each other at a distance of 1 = 100 500 μm. Then the process is repeated.

Almost instantaneous relative movement of the parts leads to the fact that the irregularities 6 located in the cavity of the wave do not come into contact with the chamfer 7 and do not crumple, and after assembly, when the wave is leveled, they come in contact with the mating surface of the shaft and increase the mechanical component friction forces and, therefore, the strength of the joint.

In addition, at a high speed of deformation in the section of the slice and crushing of irregularities during the breakdown 1 '(Fig. 2), conditions arise for increasing the molecular (adhesive) component of the friction forces, which further increases both the wave amplitude and the strength of the joint.

The method can also be carried out when the press equipment of reduced stiffness and power serves as an elastic bond.

Example. 20 samples of shaft-sleeve-type connections with geometric parameters were manufactured: connection diameter D 20 mm, sleeve outer diameter 30 mm, shaft inner diameter d 10 mm, connection length L 20 mm.

The material of the shaft and the sleeve is steel 35. The mating surfaces are machined by turning with a roughness R _{q of} 1.25 μm. The interference fit is maintained equal to N = 30 μm. When pressing five samples of joints, a spring is used as an elastic bond, selected in such a way that its draft by 30-40% requires an effort equal to the final pressing force. The speed of movement of the punch press mod. P-125 is 10 ~ ^ m / s. When pressing in the other five samples, press equipment of reduced stiffness and power — press mod — is used as an elastic bond. 2PG-10 (at the limit of 50 kN). The speed of movement of the punch is the same as in the previous case.

Thus, due to the use of elastic bonding when pressing parts under a press, the strength of the joint increases.

FIG. 2 b

Claims (1)

METHOD FOR CONNECTING PARTS WITH TENSION by pressing a press on one of the parts into another and tearing off the resulting connection by longitudinal relative movement of the parts, characterized in that, in order to increase the strength of the connection, breakdowns are carried out periodically during the pressing process by transferring force from the press slider to the pressed part through elastic connection, and the slide is moved at a speed of 5 Ί 0 - 50'10 m / s. "Er fig 1