RU204886U1 - Impulse punching device - Google Patents

Abstract

The utility model relates to the field of processing materials by pressure and can be used for stamping parts from sheet material. The device for impulse stamping contains a matrix and a combustion chamber coaxially located above it, equipped with means for supplying and igniting fuel and located in a housing containing an annular cavity, in which an annular piston is installed with the possibility of interacting with a stamped blank, and a spool with a two-stage piston. The spool cavity on the side of the piston stage having a smaller diameter is filled with liquid and connected to the annular cavity. The annular cavity is located coaxially to the combustion chamber, and the spool on the side of the piston stage, which has a larger diameter, is in communication with the combustion chamber. As a result, corrugation is prevented during the stamping process. 2 ill.

Description

The proposed utility model relates to the field of metal forming and can be used for stamping parts from sheet material.

Known devices for sheet stamping, in which the stamping process is carried out under the action on the surface of the workpiece of the gas pressure pulse generated during the combustion of the fuel mixture (Stepanov V.G., Shavrov I.A.High-energy pulse methods of pressure treatment. - L .: Mechanical engineering, 1975 .-- S. 59-69). These devices are distinguished by their compactness and simplicity of the used stamping equipment.

The closest analogue to the claimed object is a device for impulse stamping, containing a matrix, coaxially located above it and placed in a single housing and communicating with each other by means of a bypass valve, a working chamber and a combustion chamber equipped with means for supplying and igniting fuel, and made in the housing coaxially working chamber and an annular cavity connected to it through a channel, in which an annular piston is installed with the possibility of interaction with a stamped workpiece, as well as a spool with a two-stage piston installed in a channel connecting the annular cavity with a working chamber (RF patent No. 2309019 IPC V21D / 2608).

The disadvantage of the known device is as follows. The stamping process takes place after the combustion chamber bypass valve is opened. In this case, the gas flowing out of the combustion chamber expands in the volume of the working chamber, and its pressure decreases significantly. Therefore, the maximum gas pressure on the surface of the forged workpiece is significantly less than the maximum gas pressure in the combustion chamber. The height of the working chamber is commensurate with the height of the annular piston located coaxially to the working chamber. Therefore, the volume of the working chamber is at least 1/4 ... 1/5 of the volume of the combustion chamber.

The gas expansion process can be considered adiabatic due to its transience, then the maximum pressure in the working chamber is equal to:

,

,

where Pkmax is the maximum pressure in the combustion chamber;

Vk is the volume of the combustion chamber;

Vp is the volume of the working chamber;

k is the adiabatic exponent.

получим Ppmax=0,79⋅Pkmax, а при

получим Ppmax=0,75⋅Pkmax. Таким образом, максимальное давление в рабочей камере, по крайней мере, на 21% меньше максимального давления в камере сгорания. Это приводит к увеличению расхода топлива, что снижает экономичность устройства для импульсной штамповки.For combustion products, we can take k = 1.28. Then at

we obtain Ppmax = 0.79⋅Pkmax, and for

we get Ppmax = 0.75⋅Pkmax. Thus, the maximum pressure in the working chamber is at least 21% less than the maximum pressure in the combustion chamber. This leads to an increase in fuel consumption, which reduces the economy of the impulse stamping device.

The technical task of the utility model is to increase the efficiency of the device for impulse stamping.

The technical effect of the utility model is achieved by the fact that in a device for impulse stamping containing a matrix and a combustion chamber coaxially located above it, equipped with means for supplying and igniting fuel, and located in a housing containing an annular cavity, in which an annular a piston, as well as a spool with a two-stage piston, and the spool cavity on the side of the piston stage having a smaller diameter is filled with liquid and connected to the annular cavity, the annular cavity is located coaxially to the combustion chamber, and the spool on the side of the piston stage having a larger diameter is in communication with the chamber combustion.

A device for impulse stamping is shown schematically in FIG. 1 and 2, where in FIG. 1 shows a longitudinal section of the device, and FIG. 2 shows its top view. The device contains a housing 1, in which a combustion chamber 2 with a bypass valve 3 is located, which closes its central opening and a matrix holder 4 with a matrix 5. The body 1 and the matrix holder are interconnected by means of bolts 6, washers 7 and nuts 8. The combustion chamber 2 is equipped with an inlet valve 9, exhaust valve 10 and spark plug 11. In the lower part of the housing 1, coaxially to the combustion chamber 2, there is an annular cavity 12, in which an annular piston 13 is installed. This cavity and the combustion chamber 2 are connected to each other by a pipeline 14, at the end of which a spool 15 is installed with a two-stage piston 16. The cavity of the spool on the side of the large diameter of the piston 16 is connected to the combustion chamber 2, and the cavity adjacent to the smaller diameter of the piston 16 is filled with liquid and connected by a pipeline 14 to the annular cavity 12. The stamped blank 17 is installed on the matrix 5 and is pressed by the annular piston 13.

The device for impulse stamping works as follows. The combustion chamber 2 is filled with a fuel mixture through the intake valve 9, which is then ignited by means of a spark plug 11. As a result of the combustion of the fuel mixture, the pressure in the combustion chamber 2 increases many times. Under the action of the products, the bypass valve 3 moves upward, opening the central opening of the combustion chamber 2. In this case, the combustion products, acting on the surface of the workpiece 17, deform it in the cavity of the matrix 5 - the part is stamped.

In the process of stamping, the pressure from the combustion chamber 2 through the spool 15 and the pipeline 14 is transferred to the annular cavity 12. At the same time, due to the presence of the two-stage piston 16, the pressure transmitted to the cavity 12 is significantly higher than the pressure in the combustion chamber 2. Under the action of this pressure, the annular piston 13 reliably presses the flange part of the workpiece 17 to the end of the matrix 5, which prevents corrugation during stamping.

After the end of the stamping process, the outlet valve 10 is opened, and gas is released from the combustion chamber 2 and the annular cavity 12. This stops the clamping of the blank flange by the annular piston 13. Then, by unscrewing the nuts 8, the body 1 is detached from the die holder 4, and the stamped part is removed from the die 5. After that, a new blank is installed on the end of the die 5, and the body 1 is attached to the die holder. Further, the working cycle of the device is repeated in the same sequence.

Unlike the known device, this device does not have a working chamber. When the bypass valve is opened, the gas escaping from the combustion chamber immediately acts on the surface of the blank to be stamped. As a result, the maximum pressure on the surface of the workpiece is practically equal to the maximum pressure in the combustion chamber. This provides a significant reduction in energy consumption for the stamping process.

Claims (1)

A device for impulse stamping, containing a matrix and a combustion chamber coaxially located above it, equipped with means for supplying and igniting fuel and placed in a housing containing an annular cavity, in which an annular piston is installed with the possibility of interaction with a stamped blank, and a spool with a two-stage piston, and the cavity the spool on the side of the piston stage having a smaller diameter is filled with liquid and connected to the annular cavity, characterized in that the annular cavity is located coaxially to the combustion chamber, and the spool on the side of the piston stage having a larger diameter is in communication with the combustion chamber.

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