SU749916A1 - Unit for thermal removal of fins - Google Patents

Description

The invention relates to the field of mechanical engineering and can be used in devices for thermal deburring. A known installation for thermally removing burrs, comprising a support frame on which a thermal chamber is fixed with a movable bottom i. The bed is made in the form of a cylinder with windows, one of which is used for loading - unloading, the other - For ventilation. The bottom of the chamber is designed as a machine for overlapping in the extreme upper positions of the cylinder windows. The part is loaded into one of the cylinder windows on the lid and 11od by the action of the locking mechanism, the lid with the part rises vertically upwards and locks the chamber. After it is filled with a mixture of combustible gases with the help of a dazhigan candle, an explosion occurs in the chamber due to high pressures and temperatures, the burrs burn from the chamber space. A known installation for rapid high-energy deburring, comprising a closed chamber with a free volume inside, is obtained by connecting the chamber to the lid using a locking mechanism 2. The locking mechanism consists of a lid moving in a direction vertically upward, a pusher moving with a three-hinged lever operating from the cylinder. A hot gaseous composition under pressure is introduced into the free volume of the chamber, after which an explosion is initiated. As a result of the explosion in a hermetically sealed chamber, the burrs are removed from the parts under the action of a high (3500-4000 ° C) temperature. A disadvantage of the known installations is that, due to the significant pressures in the chamber at the time of the explosion (50 O-100 O kg / cm) and large areas of the lid (300-4 OO cm), the locking mechanism is quite large (2 O-40 O t) equal to the cover area was produced at the chamber pressure at the moment of explosion. The pressure in the chamber is required. It is impossible to escape, otherwise it is impossible to reach high temperatures. Thus, to reduce the force on the locking mechanism, it is necessary to reduce the cover area .; If you reduce the area of the cover, then It is impossible to load the camera with details of the size of two.

Thus, the disadvantage of these installations is the complexity and cumbersome design, as well as the unreliability of the pa6otbi locking mechanism of high specific pressures arising at the time of explosion.

The purpose of the invention is to simplify the design and increase its reliability in the work of the nyteM to relieve the loads from the locking mechanism.

  Achieved by the fact that the installation is equipped with a housing made with an internal conical opening corresponding to the configuration of the combustion chamber and C in a possibility of longitudinal movement, the combustion chamber having a rotation mechanism relative to the longitudinal axis and the loading window located in its upper wall, besides , the hull surface of the case is made of labyrinth annular grooves

FIG. 1 -. General view of the installation; in fig. 2-3 section A-A in FIG. 1 {loading capacity during loading and unloading); in fig. 4 shows a section BB in FIG. 1 (camera rotation mechanism).

The installation includes a frame 1, on which a combustion chamber 2 with a loading window 3, a gas release channel 4, sealing rings 5 made of resilient antifriction material, a camera rotation mechanism 6, a movable body 7 with mechanical labyrinth seals 8, a mechanism lock 9, the device 10 for feeding and igniting the mixture of gases and the workpiece 11.

The installation works as follows.

The workpiece is placed in the cavity of the combustion chamber. Using the mechanism, lock the housing 7 pulls down the dH lffa chamber and squeezes the sealing rings, locking it. In the labyrinth col-

The grooves are pumped with liquid (for example, water) and through the channel with the aid of a mixture supply device, and the ignition of the combustion chamber gases is filled with a gas mixture.

After ignition and explosion of the mixture, part of the effort is perceived by the lid and closed on it, the other part of them is perceived by the camera and also closed. it falls on it and is only insignificant (3.5 - 7.0 tonnes) a part of the effort is perceived by the locking mechanism and locked on the frame. In the proposed installation, the pressure on the locking mechanism is equal to the product of the pressure on the difference of the areas of the projections of the left and right half of the plane. When the cavity of a cylindrical chamber is made, the difference in the areas of the projections of the halves of the cavity is O, and hence the forces acting on the locking mechanism are O

However, with this design, in the process of joining the camps and the lid, there would be frictional forces that contribute to the rapid wear of the contacting surfaces of the chamber and the lid and the deterioration of the chamber sealing. Therefore, the walls of the chamber and the inner surface of the housing are tapered with a minimum permissible taper. In this case, the difference in the areas of the projections of the sections will also be minimal, and consequently, the effort on the locking mechanism is minimal.

 So, with a taper of 1, the force is 3.5 to 7.0 tons, which is 50 to 60 times less than the equivalent. The forces arising at the time of the explosion are perceived by the camera and the flap and the closure, without affecting the mechanism.

In this installation, inaccuracies in its manufacture between the conical surfaces of the chamber and the body can be gated by gaps through which the mixture of gases fed into the chamber under a certain initial pressure (several tens, atm) can penetrate into the atmosphere. To compensate for these gaps, the chamber has sealing rings of resilient antifriction material (for example, fluoroplast-4). When the gas mixture explodes in the chamber, pressures of the order of 500–10OO kg / cm and temperatures of the order of 35OO – 40OO ° C arise.

Sealing rings of such pressure and especially temperatures cannot withstand (maximum pressure 300 atm, maximum temperature 250 C) and hot gases penetrating into the gaps will cause combustion of materials of the sealing ring chamber and the housing, the drive chamber e is worthless .-. If, after sealing the chamber, in a labyrinth ring seal, water is supplied under a certain pressure. (1-2 atm), then under the action of capillary forces, water will penetrate into the gap between the chamber and the lid, fill it, which will protect the sealing rings from the destructive effect of pressure and temperature, since the viscosity of water is 50 times higher than the viscosity of gases ( under normal conditions) and the boiling point of water does not beat above 10 ° C (under normal conditions) Taking into account the rapidity of the explosion process (several microseconds) pressure and the temperature at the surface of the sealing rings will change slightly, ensuring their long-term preservation and performance. Opening the camera in reverse order. The part is unloaded by turning the combustion chamber around the axis cavity down. According to the measure of wear of the sealing rings, the locking mechanism, having a power reserve, moves the body by a large amount. ; The location of the loading capacitance axis perpendicular to the axis of the chamber cone allows the load to be redistributed, most of which are perceived

the camera and the body, and only a small part of them to transfer to the mechanism of the lock. ...

In this installation, the load from the locking mechanism is reduced in comparison with the existing installations by 5O - 7

Sources of information taken into account in the examination

1. USSR author's certificate No. 556186, C 21 D 1/82, 1972.

2. The US patent K 3666252, 266-2R, published. 1970. 66 60 times. Removing loads from the locking mechanism reduces its dimensions and power consumption} and increases the reliability of the locking mechanism due to the elimination of intermediate links and j decrease the specific pressure on the mechanism. The labyrinth annular grooves made on the conical surface of the lid prevent penetration of combustion products at the time of the explosion.

Claims (1)

1 .., i., - ".  749916 Unloading atpyiKu FIG. 2 FIG. five