Device (1) for improving a cavity (8), particularly a cavity in a porous, perforated material having hollow spaces uncovered by the cavity comprising an element (2) to produce or coupling mechanical energy and a cylindrical sleeve ( 4) with cylindrical side surface with an outer diameter and a central cavity (26) for receiving a guide (3) pin, a guide (3) pin and amelioration sleeve (6), the pin being configured guide (3) before the application of mechanical energy, substantially so that it can be introduced to the bottom of the cavity (8), the guide pin (3) being surrounded in the region of its end facing the bottom of the cavity, one amelioration sleeve (6) consists of a liquefiable material with mechanical energy, wherein the cylindrical side surface of the amelioration sleeve (6) substantially the same outer diameter as the sleeve (4), the guide pin (3) being housed in the center (26) cavity slidably so that, the mechanical energy applied, the sleeve (4) slidable relative to the guide (3) spike towards the bottom of the cavity (8) for liquefying and lateral and / or longitudinal displacement of the material of the amelioration sleeve (6), characterized in that the guide (3) pin can be inserted into the sleeve (4) to a stop position in which the guide pin (3) ends at flush with the distal end of the sleeve (4).Dispositivo (1) para mejorar una cavidad (8), especialmente una cavidad en un material poroso y agujereado que presenta espacios huecos descubiertos por la cavidad, que comprende un elemento (2) para producir o acoplar energía mecánica, así como un manguito cilíndrico (4) con superficie lateral cilíndrica con un diámetro exterior y con una cavidad central (26) para alojar una espiga guía (3), una espiga guía (3) y un casquillo de mejora (6), estando configurada la espiga guía (3), antes de la aplicación de energía mecánica, sustancialmente de tal forma que puede introducirse hasta el fondo de la cavidad (8), estando rodeada la espiga guía (3), en la zona de
