RU2400346C2 - Procedure for wheel dressing - Google Patents

Abstract

FIELD: machine building.

SUBSTANCE: invention refers to machine building and can be implemented for automation of grinding process, particularly for wheel dressing. Wheel dressing is performed per several passes. Rotation is imparted to the wheel, while lengthwise transfer along wheel generatrix is imparted to a dressing tool. Upon each lengthwise transfer cross transfer is imparted to the dressing tool. Value of cross transfer is chosen depending on character of wear of working surface. Further, the abrasive disk is sparked out. A sound signal, amplitude of which is determined in each pass, is used as a signal characterising process of dressing. Time for dressing end is determined, when amplitude of the sound signal reaches setting A'_s, which is specified before beginning of dressing with preliminary dressed abrasive disk. Abrasive disk is sparked out without removal of abrasive.

EFFECT: raised efficiency of dressing and reduced wear of abrasive and dressing tools.

2 dwg

Description

The invention relates to mechanical engineering and machine tool industry and is intended to automate technological processes on grinding machines.

A known method of dressing the grinding wheel (see Tergan BC Flat grinding // Textbook for prof. And technical schools. Ed. 2-nd, revised and additional - Moscow: Higher school, 1974. - P.184 -194), in which the required shape and cutting ability are provided by turning the circle with a diamond ruling tool.

The disadvantage of this method is that the dressing process of the grinding wheel is not controlled, the removed allowance is assigned according to reference materials that do not correspond to the real state of the surface of the wheel, which leads to a large consumption of abrasive material during the dressing process and wear of the ruling tool.

The closest method of the same purpose to the claimed invention is the method of dressing the grinding wheel (see US Pat. RU 02160659, C2 20001220, R f, IPC V24V 53/04, 2000), in which dressing is carried out in several passes, with the message grinding the rotation circle, and the ruling tool of longitudinal movement along the generatrix of the circle, after each longitudinal movement, the tool is informed of the transverse movement, the value of which is selected depending on the nature of the wear of the working surface, with electrically conductive layers, and at the draft stage, the moment of contact with the ruling tool touches the electrically conductive layer at the end of the circle having the smallest diameter wear and the draft stage is stopped, while when the moment of contact of the electrically conductive layer is fixed at the end of the circle with the largest diameter wear, the stage of rough editing is stopped .

The reasons that impede the achievement of the technical result indicated below when using the known method adopted as a prototype include the need for special refinement of the grinding wheel for applying an electrically conductive layer and embedding sensors and a control unit on the governing tool, which limits the versatility of the method, as well as the lack of reliable control of the depth of the film being removed abrasive layer when editing.

The invention consists in the following. In order to improve the quality of dressing, control is carried out by measuring the parameters of the sound signal arising in the process of dressing the grinding wheel.

The technical result is to increase the productivity of the dressing process and reduce the consumption of the grinding wheel and the ruling tool.

The specified technical result in the implementation of the invention is achieved by the fact that in the known method of dressing a circle, including dressing in several passes with a message to the grinding wheel rotation, and the ruling tool longitudinal movement along the generatrix of the surface of the circle, while after each longitudinal movement of the tool report lateral movement, the value of which choose depending on the nature of wear of the working surface, characterizing the dressing process, the feature is that as the signal characterizing the editing process, use the sound signal, determine the amplitude of the sound signal A _Z in each of the passes when removing the abrasive layer from the grinding wheel with a given depth, when the amplitude reaches a certain value of the setting A ' _Z , for which the amplitude of the sound signal of the straightened circle is taken, dressing is stopped and the circle is taken care of without removing the abrasive.

Information confirming the possibility of carrying out the invention to obtain the above technical result: figure 1 is a block diagram of the implementation of the method; figure 2 presents a graph of changes in the amplitude of the sound pressure A ₃ and the depth of the abrasive layer h removed from the editing time.

The method of controlling the process of dressing the grinding wheel is carried out according to the scheme shown in figure 1.

The sound signal transducer (microphone) 1 is installed in the grinding wheel casing 2, which is in contact with the governing tool 5. The transducer 1 is electrically connected to the computer 3 by means of an analog-to-digital sound signal transducer (sound card) 4. The amplitude of sound vibrations arising during the editing process, recorded by the Converter 1 and converted into an electrical signal, which is transmitted to the computer 3, where it is compared by the value of the setting A ' _{Z the} amplitude of the audio signals.

Before starting processing rule grinding wheel, measuring sound pressure amplitude value A _W, which is taken as the set point A _'W. A grinding wheel 2 with a worn working surface is installed in the machine spindle and rotated at a speed of V _cr . The ruling tool 5 is moved along the generatrix of the surface of the circle 2 with a longitudinal feed S _CR and in the radial direction with a transverse feed S _pop . Due to these movements (V _cr , S _pp , S _pop ), they make an edit - remove the abrasive layer h on the working surface of the circle (Fig. 1). Thus from passage to passage increases the amplitude of the audio signal which is recorded by the transducer 1 and is converted into a digital signal and transferred to the computer 3, which is compared with the setting value A _'W. Upon reaching the setpoint amplitude signal A _'W zukovogo signal amplitude editing is performed is stopped and nursing range without removal of the abrasive.

The analysis of the prior art by the applicant, including a search by patent and scientific and technical sources of information and identification of sources containing information about analogues of the claimed invention, allowed to establish that the applicant did not find a source characterized by features identical to all the essential features of the claimed invention. The definition from the list of identified analogues of the prototype as the closest in the set of essential features of the analogue made it possible to establish a set of significant distinguishing features in relation to the technical result perceived by the applicant in the claimed method set forth in the claims.

Therefore, the claimed invention meets the condition of "novelty."

The achievement of the technical result is confirmed experimentally on the machine 3E711B. Before grinding each billet made of 50KhGFA steel, the grinding wheel of characteristic 25A25NT16B was straightened. The peripheral speed of the wheel during grinding and dressing V _k = 35 m / s. The billets were ground with constant removal of the stock z = 0.16 mm at a mortise feed speed V _s = 0.60 mm / min. Grinding the workpiece and dressing the circle was carried out with the supply of 3% coolant Akvol-6.

The dressing circle was made with diamond in the frame AD-3. Editing mode: S _ol = 1.0 m / min; S _t = 0.015 mm / double stroke; h = 0.12 mm.

The amplitude of the sound signal was recorded during straightening of the circle at a frequency of 440 Hz. The amplitude of the sound signal A _{3 was} measured by the amplitude value of the effective voltage of the investigated sound signal.

Detailed Description of the invention to give the above technical result: Figure 2 is a graph showing changes in time τ audio signal amplitude A _W and the depth h of the abrasive peeling layer within one cycle changes characterizing the essence of the described method.

The proposed method for controlling the editing process includes recording the amplitude of the audio signal during each of the n editing passes (Fig. 2). As can be seen from figure 2, from the passage to the passage with a constant depth h of the abrasive layer to be removed, the amplitude of the sound signal increases, which indicates the restoration of the cutting ability of the grinding wheel. This regularity, as shown by preliminary experimental studies, can be traced regardless of the depth at which the abrasive layer is removed h. Upon reaching the setting A ' _{Z of the} amplitude of the sound signal corresponding to the straightened circle, the supply of the ruling tool to the depth of the abrasive layer to be removed is stopped and the circle is nursed without removing the abrasive. The number of passes when nursing is determined by the requirements for the quality of the polished surface of the parts.

Thus, as a result of using the proposed technical solution, it becomes possible to control the dressing process of the grinding wheel, the productivity and quality of dressing are increased, and the consumption of grinding wheels is also reduced.

Claims (1)

The dressing method of the grinding wheel, including dressing in several passes with a message to the grinding wheel to rotate, and to the ruling tool - longitudinal movement along the generatrix of the wheel, and after each longitudinal movement the tool is informed of the transverse movement, the value of which is selected depending on the nature of wear of the working surface, and also nursing the grinding wheel, characterized in that as a signal characterizing the dressing process, use an audio signal whose amplitude th is determined in each of the passageways when removing the abrasive layer from the grinding wheel and the closure time is determined by reaching changes audio signal amplitude setting value A _'W, which is set before editing and to rectify the grinding wheel, and produce nursing range without removal of the abrasive.

Images