RU1788035C - Apparatus for thermal removal of burrs from elongate articles - Google Patents

Abstract

SUMMARY OF THE INVENTION: in a device comprising an elongated chamber, a sealing cover, a system for supplying a combustible mixture to the chamber, and a means for igniting the mixture, the latter is made of igniters interconnected with the possibility of simultaneous ignition and placed along the chamber at a distance from one of the end walls, by the accepted relation X «у- (2k -1), where I is the length of the chamber, n is the number of igniters, and k is the ordinal number of the igniter. 2 ill., 1 tab.

Description

The invention relates to mechanical engineering, in particular to surface hardening technology, as well as deburring, flaking, rounding of sharp edges formed during machining, injection molding, and also to hardening of surfaces by gas explosion.

A device is known in which one or more workpieces is placed in a glass with holes, the glass is separated from the valve by a low-melting film, the cap is filled with a combustible mixture, and the mixture is ignited. Due to the increase in pressure, incandescent products of combustion break through the film and briefly flow around the products, firing burrs. The method reduces the consumption of the combustible mixture when processing through holes, however, it is ineffective when cleaning areas of the product that are difficult to stream around, in particular blind holes.

The closest in technical essence to the claimed is a device

for heat treatment of articles comprising an elongated chamber, a sealing cover, a system for supplying a combustible mixture to the chamber, a mixture ignition device, and an exhaust valve.

The main disadvantage of such devices is the low efficiency of the product processing process due to the low rate of heat transfer in the chamber during an explosion. Indeed, when the mixture explodes, a detonation wave is generated, the profile of which has a region of increased pressure, temperature and speed, which also has a short-term intense thermal effect on the treated healing (surface hardening, deburring). Sequentially reflected from opposite walls, the wave also affects the products. The processing process is more effective, the more often the area with high pressure, temperature and speed will be affected

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steal on the part. In long chambers (the length of the chamber is caused by the need to process long products), the frequency of exposure is low, the efficiency is low, which is manifested in the unevenness of the hardened layer and the small thickness of the burrs to be removed. By increasing the flow rate of the combustible mixture, it is possible to slightly increase the efficiency of the process, however, the desired results are not achieved. For example, when hardening gear racks in such chambers with a gas flow rate of up to 30, it is possible to obtain a layer thickness on the protrusion of up to 2 mm, while the tooth cavity remains not hardened at all.

The aim of the invention is to increase the efficiency of the process by intensifying heat transfer in the chamber.

This goal is achieved in that, in contrast to the known device for heat treatment of long products, containing a chamber with a sealing cover, a system for supplying a combustible mixture and removing products of explosion, an apparatus for igniting the mixture, and in the apparatus an apparatus for igniting made of interconnected, with the possibility of simultaneous ignition, ignitors located along the length of the chamber at a distance from one of the end walls, defined by the ratio:

Xk (2k-1).

where I is the length of the chamber;

p - the number of igniters, equal to 1, 2, 3 ... and t: d .;

k - ignitor serial number .- -:

Figure 1 shows a general diagram of an inventive device; Figure 2 is a diagram of the distribution of blast waves in a device.

1 - a cylindrical chamber, 2 - a cap sealing chamber with an integrated system 3 for supplying a combustible mixture.

The device also includes a device 4 for igniting the mixture, made in the form of interconnected with the possibility of simultaneous ignition and distributed over the length of the chamber at a distance Xn from the end wall. Figure 1 shows a particular case of the placement of igniters along the axis of the chamber. The device is equipped with a valve 6 for discharging explosion products.

The device operates as follows.-.-;.-.-- - .. .- ... -.-:

The processed long articles 1 are placed in the chamber 1. For example, the gear racks are sealed, filled with a combustible mixture and set on fire. Due to the declared location of igniters along the length of the chamber at a given ratio, the distance between them will be two

times more than between the igniter and the end walls. For example, with n 2 and a chamber length I of 1.2 m, the first igniter will be located at a distance of 0.3 m from the end wall, and the second at 0.9 m.

0 Thus, the distance between the igniters will be 0.6 m, and the distance from the walls to the igniters 0.3 m. This allows detonation waves formed to be reflected from the chamber walls and from each other at the same time. As a result, a stable frequency wave is established in the chamber, the gas oscillation frequency in which is determined by the number of igniters. When n 1 that

0 is a special case of the claimed ratio; the igniter is located in the center of the chamber. The physical essence remains the same as with item 1. A stable frequency wave with a doubled frequency of oscillations is established in comparison with the known placement of the candle at the end of the chamber.

The process will be all the more effective the more often the part will be affected by the area with increased pressure, temperature and

0 speed, i.e. the more often there will be an oscillation of the detonation wave. The number of igniters is selected depending on the type of heat treatment (deburring, hardening) on the length of the chamber, from

5 thicknesses of removable burrs.

PRI me R. Under the conditions of the DMetI laboratory, a comparative analysis of the claimed device and the prototype device was carried out. Into a 7 L chamber

A gear length of 420 mm was placed at 0.8 m for surface hardening. The chamber was filled with an oxygen-acetylene gas mixture. For the prototype device, an ignition device was used

5 candle mounted in the lid of the chamber. For the inventive device from the candle, two distributing tubes were installed, respectively installed according to the claimed expression. The results are tabulated.

0 In the inventive device, the treatment of the gear rack was more efficient, since hardening occurred, like the protrusion and the tooth cavity, and the thickness of the hardened layer is uniform.

5 In the prototype, despite the large thickness of the hardened layer of the protrusion of the tooth with increased consumption of the mixture, the tooth cavity remained unchanged.

Thus, the inventive device allows to solve the problem of intensification

heat transfer in the chamber, which leads to an increase in the efficiency of the heat treatment of products.

Claims (1)

SUMMARY OF THE INVENTION A device for thermally deburring long products, comprising a chamber with a sealing cover, a system for supplying a combustible mixture and removing products of explosion, a device for igniting a mixture, characterized in that, in order to increase the efficiency of the process due to intensification heat exchange, the ignition device is made of igniters interconnected with the possibility of simultaneous ignition, placed along the length of the chamber at a distance from one of the end walls, defined by the ratio: 2n 0 where I is the length of the chamber; p is the number of igniters; k is the sequence number of the igniter. Xk -42k-1), Phage 2 Editor Compiled by E. Popov Tehred M. Morgenthal 1 Proofreader L. Lukac