The method of pressing parts, electro-mechanical press

 

(57) Abstract:

Usage: in the field of Assembly production upon receipt of the connection parts with tension. The inventive surfaces of parts for Electromechanical press pressure stage, characterized by the presence contact end surfaces of the parts to be assembled, make a loop n times. After each cycle measure the relative displacement of the parts, which is compared with the offset value from the previous cycle. The number of cycles is chosen from the condition of equality of the difference values of the offset after the current and previous cycles value smaller than the set value determined based on values of tolerance on the size of the connection. 3 Il.

The invention relates to the field of mechanical production and can be used in the Assembly of the connection tightness with emphasis in the shoulder.

There is a method of pressing parts, electro-mechanical press, namely, that to detail put pressure (SU, AV. St. 171228, B 23 P 19/02, 1965).

This method does not provide the required quality of Assembly with high connections, since the elasticity ends, due to both opporsite joint between the ends of the mating parts.

Technical problem which the claimed invention is directed, is to improve the quality of Assembly and forging connections.

To solve the problem in the way of pressing parts, electro-mechanical press pressure to the parts on stage, characterized by the presence contact end surfaces of the parts to be assembled, adjacent loop n-times measurement after each cycle of the magnitude of relative displacement of the parts, which is compared with the offset value from the previous cycle, and the number of cycles is chosen from the condition of equality of the difference values of the offset after the current and previous cycles magnitude smaller than the set value determined based on values of tolerance on the size of the connection.

After apresski parts like rings on the shaft with an emphasis in the shoulder and off the supply voltage for the torque DC motor with Electromechanical press system upravleniya engine form a series of pulses of duration tcproviding multiple repetition of the final stage of apresski, each time after reaching the limiting value of current Imaxin the supply circuit of the motor drive on the I absence of stresses along the axis of the connection. As for high-torque DC motors the value of the current Imstrictly corresponds to the force F, Imaxmatches the specified value of the pressing force Fmax.

Every time the loading can reduce the proportion of plastic deformation in each subsequent single cycle. In the process of loading the recorded characteristics of current rise time-I=I(t). The process of forming the connection ends in the case when the previous and subsequent characteristics differ by the value less than specified:

i-i-1[] (1);

where

ithe offset after the current single loading cycle;

i-1the offset after the previous loading cycle;

[] is a valid offset value (determined based on values of tolerance on size).

The number of loading cycles (n) value is not a constant and even within the same batch of parts may vary. The main factors affecting the value of n, are the pitch (T) and height (H) of the irregularities on the end surfaces in the pair, the plasticity of the materials (t) mating parts of their macroform (f) and size tolerances () on the dimensions of the mating surfaces. Stalinite for:

< / BR>
where the subscript "I" refers to covered detail and "2" to covering.

In addition to the registration of the current values, each time it is necessary to determine the amount of displacement of the parts when unloading connection. This purpose can be used a linear position sensor, for example, the range of incremental correction, allowing you with the necessary degree of accuracy to determine bias in our case. If items are shifted by an amount greater step roughness on one of the parts, the process of razrusheniya should stop and go to the loading cycle, as in the case of non-compliance with this condition will loosen the connection, which will significantly reduce its qualitative characteristics.

In Fig. 1 shows a graph of the voltage on the motor (control) by time on the stage of additional pressurizing, where tc- the duration of a single cycle of additional pressurizing and tptime.

In Fig. 2 depicts a graph of rise of current (power offset) time for additional pressurizing cycle, where Imaxmatches the maximum value of the current to the motor. The process ends when the difference between the bias current and predydushih the technical press. Coming from engine 1 to the current value of the current is compared with the Imaxin block comparison (BS Imax) 2 and is recorded in a storage device (memory) 3. When the motor current maximum value of BS Imaxsignal is output to the drive motor 4 to shut off the voltage to the motor. At the same time BC Imaxoutputs a signal on the memory and the block comparison of the previous and current dependencies I=I(t) (BS I) 5, which terminates fix in the memory the current values of 1 and BS I is a comparison of the previous and the measured dependencies I=I (t). If the difference value does not exceed, BS I outputs a signal to the actuator 4 to complete the process, otherwise the timer 8 generates a delay tpand the process repeats again. During each cycle is controlled by the displacement of the Executive bodies of the press by removing from the position sensor 7 current displacements and comparison unit comparing the move (BS S) 8 with a valid value.

An example implementation of the method.

The pressing parts like bearing rings on the shaft with an emphasis in the shoulder was performed on electro-mechanical press using the system control device described above.

On allalmost ends of 0.05 mm) and with a constant speed napressovyvanie steel ring (material 40X with roughness of the mating surfaces Ra1,25, non-parallelism of the end faces 0.05 mm) to another in the shoulder. When reaching the load on the punch in N voltage to the motor is shut off and control is performed after the offset of the ring relative to the shaft. As the position sensor was used in line with incremental correction of the type or 340. The offset was set to 7 μm. We then conducted a time delay 1-1,5 s and was repeated loading cycle with the force pressing N. Measurement position sensor gave an offset value equal to 5 μm. Making a further five cycles of loading, managed to reduce the amount of displacement of up to 2 microns.

Similar experiments were carried out in 10 parts of the same type size. In all cases, managed to reduce the amount of displacement from 50% to 70%

Similar experiments on parts made of brass (lumc-1-1) and iron (SC), gave similar results.

The method of pressing parts, electro-mechanical press, namely, that to detail put pressure, characterized in that the pressure stage, characterized by the presence contact end surfaces of the parts to be assembled, make a loop n times measurement after each cycle the amount of relative displacement of devensive difference values of the offset after the current and previous cycles value, smaller than the set value determined based on the value of tolerance on the size of the connection.

 

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FIELD: machine engineering, possibly manufacture of sealing envelopes of corrosion resistant steels of metal-plastic high-pressure bottles.

SUBSTANCE: method comprises steps of separately making metallic convex bottoms with cylindrical collar and backing ring. Thermal expansion factor of backing ring exceeds that of bottoms; outer diameter of backing ring provides close fit of bottoms onto it at 20°C; cooling preliminarily assembled backing ring with bottoms until cryogenic temperature; sliding bottoms on backing ring in cooled state until mutual touch of cylindrical collars of bottoms; heating assembly up to 20°C in order to provide close fit of backing ring in cylindrical collars of bottoms; welding bottoms along butt of assembly and then removing backing ring by chemical milling.

EFFECT: simplified process of making envelopes with enhanced mass characteristics.

2 cl, 4 dwg, 1 ex

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