RU1797564C - Device for micrometric feed of workpieces for grinding - Google Patents

Abstract

Usage: workpiece grinding operations in engineering and instrument-making enterprises. SUMMARY OF THE INVENTION: the device comprises a base made in the form of a pivotally connected movable Plate 2 and a lower fixed plate 1. forming an angle with each other, an upper plate pivotally connected to the movable plate and installed in parallel with the lower movable plate. Two heating elements 5 are mounted on the lower fixed plate and on the upper plate at the ends opposite from the hinges with the possibility of contact with the movable plate 2. Flat springs 23 serve to return the device elements to their original position and select backlash. The device is additionally equipped with a table 10 mounted on ball bearings 12 on the upper plate with the possibility of lateral movement relative to this plate under the action of additional flat springs and an electromagnet 18 mounted on the upper plate. Additional cross. the movement of the workpiece relative to the grinding wheel at each longitudinal stroke of the table by an amount equal to half the size of the main fraction of the grains of the grinding wheel improves the quality of processing. A silt. ate with

Description

The invention relates to devices for precise feeding and can be used in engineering and instrument-making enterprises for efficient finishing by grinding workpieces with high accuracy (especially in the manufacture of microelectronics parts).

A device for accurately feeding the grinding wheel (1) is known, comprising a heating and cooling system for a thermal element, a bimetallic thermal element interacting with the movable and fixed components of the machine and made in the form of a flat two-layer washer mounted by the ends between the movable and fixed units.

The disadvantages of this device include the following: firstly, it is not universal and provides low productivity since it cannot be used to process surfaces of various profiles (cylindrical, conical, flat, etc.) without changing the machine (i.e. changing the tool) . Secondly, micropumping is carried out using a dynamically unstable part of the technological system (a headstock with a rotating friend), therefore, a large amount of energy is spent on its movement because of the considerable mass of this headstock, the feed accuracy and, as a result, the quality of the surface being processed are reduced.

 The closest in technical cyutnost and achieved results is a device for microfeed workpieces during grinding; containing a base made in the form of hingedly bonded. a movable plate and a lower fixed plate, forming an angle between themselves, the upper plate with a device for securing the workpiece mounted on it, articulated with the base plate movable in an angular direction, two heating elements mounted on the lower fixed plate and on the upper plate at opposite ends devices with the possibility of contact with the movable base plate (2).

The disadvantages of this device include the limited height of microroughnesses on the upper limit: the roughness of the surface processed by grinding depends primarily on the feed and grain size of the grinding wheel (ceteris paribus), therefore it can be reduced (when using the described device, it is impossible without replacing the circle of one grain size with shallow circle

graininess). However, in this case, grinding performance is reduced.

The aim of the present invention is to improve the quality of the machined surfaces of the workpieces during grinding without changing the grinding wheel.

The specified goal is achieved in that the device for microfeed workpieces during grinding, containing the base,

made in the form of pivotally connected movable plate and lower fixed plate, forming an angle between themselves, an upper plate pivotally connected to a movable plate and located parallel to the lower fixed plate, two heating elements mounted respectively on the lower fixed and upper movable plates on opposite ends with the possibility

0 contact with the movable plate, cover length. device enclosures, flat springs for returning the device elements to the initial position and selecting backlash, the heating and cooling system for heating elements5 is additionally equipped with a table with a magnetic core mounted on ball bearings on the top plate with the possibility of lateral movement using an electromagnet fixed

0 on the top plate and flat springs. Moreover, the electromagnet is turned on and off, in parallel with the limit switches of the longitudinal feed of the machine table, and thereby the table of the device makes reciprocal longitudinal and transverse movements for each stroke of the machine table. In FIG. 1 shows a device, a General view; in FIG. 2 - section AA in FIG. 1; in FIG. 3 is a section BB in FIG. 1; in FIG. 4 0 is a section BB of FIG. 2. The device is a base comprising a fixed plate 1 (FIG. 1), an inclined plate 2 connected to the plate 1 at one end using hinges 3 (FIG. 2);

5, the upper plate 4, connected at the other end pivotally with the movable plate 2 (Fig. 1), two heating elements 5 mounted on the upper and lower plates with the possibility of contact with the plate 2 and

0, which are hollow tubes b (Fig. 3) with plugs 7 and spirals 8 passing inside the tubes, tubes 9 (Fig. 1) for supplying coolant when cooling the heating elements, table 10 mounted on

5 with a fixture for clamping workpieces 11, ball bearings 12 between the upper plate and the table, strips 13 and a set of gaskets 14 for adjusting the tension in the ball bearings 12, strips 15 (Fig. 2) and a set of gaskets 16 for adjusting the lateral movement of the table 10 (Fig. 1) relative to the upper plate 4 (Fig. 2), the bracket 17 and the electromagnet 18 (Fig. 1), mounted on the upper plate 4 (Fig. 2), the core 19, mounted on the table with screws 20 (Fig. 4) and flat springs 21 located in the gap between the table and the bar 15 (Fig. 2). The whole device is closed by a casing 22 (FIG. 1), on which springs 23 are mounted, connected at other ends to the table 10 and serving to select backlash and return to the initial position of the device:

The device is installed using the bottom plate 1 on the table of a surface grinding machine and operates as follows. The workpiece is fixed in the fixture 11 mounted on the table 10. The machine is turned on, the machine table receives a reciprocating movement, and the grinding head receives a vertical cut-in feed, resulting in a flat grinding, in which the main part of the stock is removed from the workpiece. At the end of this stage of the grinding cycle, the vertical feed mechanism of the machine is switched off and voltage is simultaneously applied to the two heating elements 5. Due to temperature deformations, the heating elements increase their diameter and rotate the movable plate 2 around the left hinge counterclockwise, and the upper plate 4 with the stsl 10 around the right hinge clockwise at the same angle. The workpiece, fixed in the fixture 11, performs plane-parallel vertical movement, which implements the microfeed during final flat grinding. During this stage of the cycle, simultaneously with the start of the movement of the machine table to the right, the electromagnet 18 is turned on. And the core 19 together with the table 10 and the workpiece moves towards the observer by the amount set by the set of spacers 15 (0.01-0.5 mm). Upon reaching the extreme right position of the table, the electromagnet 18 is turned off and the table 10 under the action of the flat springs 21 moves in the direction from the observer to

the same value, i.e. to the starting position. Thus, the workpiece at each table stroke is shifted relative to the grinding wheel, as a result of which a higher quality of the machined surface is achieved without changing the wheel.

At the end of the processing, the voltage from the spirals 8 of the heating elements 5 is removed and a flow is supplied to the heating elements through the holes in the pipe 9

Coolant in order to cool them and return to their original size (diameter). Under the action of the springs 23, the device returns to its original position.

It should be emphasized that the transverse movement of the table 10 (trial according to experimental data) should be approximately half the size of the main fraction of the grains of the grinding wheel. For example, if the grain size of the grinding wheel is 16, then the size of the main grain fraction is 160 microns. Then the transverse movement of the table should be 80 microns (0.08 mm) in one longitudinal stroke of the machine table. Such a pattern of transverse movements of the table 10 refers to circles of all grain sizes.

As a result of the additional lateral movement of the table 10, the resulting scallops after the previous longitudinal

the reciprocating movement on the workpiece is cut off and the roughness is reduced.

Thus, the advantage of the proposed device is that

additional lateral movement of the workpiece relative to the grinding wheel at each longitudinal stroke of the table by an amount equal to half the size of the main fraction of the grains of the grinding wheel,

allows to improve the quality of the grinding surface,

Claims (1)

SUMMARY OF THE INVENTION A device for microfeed workpieces during grinding, containing a movable plate articulated at its ends with a fixed lower plate, designed to be mounted on a table of a surface grinding machine, and a movable upper plate parallel to the bottom, a device for attaching the workpiece, two heating elements mounted respectively on the lower and top plates with the possibility of contact with opposite ends of the movable plate, flat springs associated with the fixed plate, and a heating and cooling system for the heating elements, furthermore, in order to improve the quality of processing, the device is equipped with a supporting device for . fastening the workpieces and a table connected to the flat springs with an electromagnet and additional flat springs, the table being mounted on the top plate with the possibility of lateral movement relative to it on the ball guides introduced into the device, additional flat springs are placed between the ends of the table and the top t & fi g Fig.Z Editor Compiled by L. Khudobin Tehred M. Morgenthal plates on which, respectively, the core and coils of the electromagnet are fixed, connected to the longitudinal feed limit switches provided on the machine table. Fig 4 Proofreader S.Jusco