RU2147978C1 - Attachment device of grinding wheel for noncontinuous machining of wheels with round teeth - Google Patents

Abstract

FIELD: metal working. SUBSTANCE: device has moving flange with tapered hole and clamping nut. To enhance efficiency, device is provided with stationary body with external and internal tapered surfaces positioned in tapered hole of flange. Device also includes nut for attachment of body in flange. In this case, angle of cone of external surface of body is equal to an angle of flange hole cone. Axis of tapered external surface of body and axis of flange tapered hole are shifted eccentrically relative to axis of internal tapered surface of body and to axis of external surface of flange, respectively, by equal value. EFFECT: higher reliability. 4 dwg

Description

 The invention relates to the processing of metals by cutting and can be used in the manufacture of wheels with circular teeth made of hardened and especially hard-grinding steels.

 Known segment head for grinding spiral bevel wheels containing a faceplate on which abrasive segments are attached using crackers.

 The disadvantage of this tool is a sharp decrease in vibration resistance, strength and the area of the working surface of the tool due to the presence of depressions, which in turn reduces the dimensional stability of the head, the quality and productivity of processing. In addition, the difference in the contact areas of the forming surfaces of the grinding wheel with the convex and concave sides of the teeth of the gear being machined leads to the appearance of burns on the concave surfaces of the teeth or to a decrease in processing performance due to the establishment of cutting conditions based on the grinding conditions of the concave side of the teeth.

 Closest to the invention in technical essence and the achieved result is a grinding segment head for machining wheels with circular teeth, comprising a housing with abrasive segments mounted on it, having two forming surfaces, profiling simultaneously convex and concave sides of the teeth. In addition, the segments are made of different lengths, and the length of the segment processing the concave side of the tooth is less than the length of the segment processing the convex side of the tooth, and the maximum contact areas of the working surface of the segments with different sides of the tooth are equal to each other.

 However, the known grinding segment head has a significant drawback due to the presence of depressions and protrusions. When entering the cutting zone, the protruding segments and the subsequent troughs create shocks that sharply reduce vibration resistance, strength and the area of the working surface. In addition, the impact force, perceived mainly by the grains of the zone adjacent to the front edge of the working protrusion, causes intense chipping from the ligament. As the circle wears out, a profile self-registration is performed, which fundamentally changes the allowance removal scheme. This circumstance reduces the dimensional stability of the tool, the quality and productivity of processing.

 The objective of the invention is to increase the performance of gear grinding wheels made of hardened and especially hard-to-defect steels and alloys.

 The problem is solved by means of a device for attaching a grinding wheel for intermittent machining of wheels with a circular tooth, containing a movable flange with a tapered bore and a clamping nut, while it is equipped with a fixed body with outer and inner conical surfaces located in the tapered bore of the flange, and a nut for mounting the housing in the flange, in addition, the angle of the cone of the outer surface of the housing is equal to the angle of the cone of the hole of the flange, and the axis of the conical outer surface of the housing and the axis of the cones Skog flange openings are offset eccentrically relative to the axis, respectively conical inner surface of the housing and the outer surface of the flange axis by an equal amount.

In FIG. 1 shows the design of the device for attaching the grinding wheel for machining wheels with a circular tooth in the position of zero eccentric displacement of the grinding wheel; in FIG. 2 shows a diagram of a double-sided machining by grinding circular teeth with a cup cylindrical wheel mounted eccentrically relative to the axis of the tool spindle; in FIG. 3 - the same, in the position of the circle rotated 180 ^o relative to the position in FIG. 2; in FIG. 4 - section aa in figure 2.

The mounting device of the grinding cup cylindrical wheel 1 for machining wheels 2 and 3 with a circular tooth consists of a fixed body 4 (Fig. 1 and 2), made in the form of a sleeve, the outer and inner surfaces of which are truncated cones with an eccentric distance ε _{to the} axes O _to and O ₁ .

Since the housing 4 is mated movable flange 5, a tapered bore, the axis O _to which is also disposed eccentrically relative to the axis O ₂ of its outer cylindrical surface serving as a base for mounting the grinding wheel, the latter is fixed a nut 6.

 Fixing the flange 5 on the housing 4 is carried out by a nut 7.

The casing 4 introduced into the design of the device with the O axis _{to the} conical outer surface in conjunction with an eccentrically offset conical hole with the O ₂ axis _{of the} flange allows you to smoothly adjust the eccentric displacement of the grinding wheel from zero when the O ₁ and O ₂ axes coincide (Fig. 1) to ε _max = 2ε _to when the axes O ₁ and O _{2 are} diametrically located relative to the axis O _to (figure 2).

 The device assembled with the grinding wheel is mounted on the spindle 8 of the machine.

Assembly, adjustment of the device and dressing of the grinding wheel is carried out in the following sequence. A flange 5 with a grinding wheel 1 installed between gaskets made in accordance with GOST 12.3.028 80 and fixed with a nut 6 is mounted on the housing 4. On a scale (not shown), the flange 5 and the housing 4, turning relative to each other, are mutually oriented, achieving coincidence of the axes O ₁ and O ₂ , that is, zero eccentricity, and fixed with a nut 7. The entire device is fixed on the spindle 8. Initial dressing and profiling of the external “H” and internal “B” surfaces on the basis of the initial rail are performed under rolling conditions. When the tool rotates, the work surfaces "H" and "B" describe in space a ring that reproduces the depression of the producing wheel that engages with the workpiece.

After that, loosening the nut 7, rotate the flange 5 relative to the housing 4 and mutually orientate on a scale (not shown), achieving the necessary displacement of the axis O ₂ relative to the axis O ₁ . The resulting eccentricity ε _{Σ is} fixed with a nut 7. The result of this adjustment is the protrusions C _n and C _{in the} outer and inner producing surfaces (Fig. 4), which are cut off, making secondary dressing and profiling of the producing surfaces on the basis of the original rail under rolling conditions. The task of the secondary final dressing is to remove the eccentrically protruding segments C _n on the outer "H" and C _in (Fig. 4) on the inner "B" producing surfaces, while the nominal diameter D of the circle after the first and second edits is left constant.

 After editing, the circle must be carefully balanced by installing balancing weights (not shown in Fig.).

 When the tool rotates, the working surfaces H and B, which become discontinuous, also describe the ring in space with their protrusions, but the grinding process becomes intermittent, preventing burns on the machined tooth surfaces.

 Thanks to such an eccentric setting of the circle, followed by secondary dressing of only the protruding parts, its outer “H” and inner “B” producing surfaces come into intermittent contact with the workpiece. The outer "H" and the inner "B" producing surfaces have one protrusion formed by secondary dressing, and one cavity formed by primary dressing and eccentric displacement. Moreover, the protrusions of the outer and inner producing surfaces are diametrically opposed and in the tooth cavity of one workpiece work alternately: half turn - outer "H" producing surface, next half turn - inner "B" producing surface.

 In the case of simultaneous processing of two workpieces (figure 2), the protrusion of the outer producing surface processes one workpiece, and the protrusion of the inner producing surface processes the second workpiece.

 Thus, the proposed wheel attachment device for grinding cylindrical wheels with circular teeth allows grinding at certain intervals, which reduce the temperature in the working area. Moreover, the cutting time between these intervals is equal to the time the process breaks. The thermal saturation of the metal stops and during the break the surface of the workpiece is cooled. Due to the intervals of the process rupture, it is possible to significantly reduce the temperature in the cutting zone and to avoid the occurrence of grinding defects that worsen the operational properties of the parts.

When processing the proposed device with the wear of the circle, blunting and greasing of its working surfaces of the protrusions, the cutting surfaces of the depressions are introduced into the work. To do this, return the circle to its original position, which it occupied after the first edit, i.e. to a position with a total eccentricity of zero
ε _Σ = 0.
In this position, blunt, lost cutting properties, the working surfaces of the spent protrusions will be in the depressions and will not participate in the processing.

 The proposed device with this changeover wheel allows you to fully use the total number of grains contained in the whole circle, while effectively using the advantages of intermittent grinding. The consumption of an abrasive tool is reduced by 25-50% compared with intermittent circles.

 The proposed device compares favorably with increased vibration resistance due to the smooth and shockless entry and exit of the protrusions of the cutting abrasive surface into the cutting zone, high tool strength due to the integrity of the grinding wheel, although the process itself is intermittent. This increases the dimensional stability of the tool, prevents breakage and chipping of the abrasive, and lowering the temperature in the grinding zone allows to increase the intensity of the process, productivity and quality of processing.

 The advantage of the device for intermittent machining of wheels with a circular tooth grinding wheel mounted eccentrically is the comparative simplicity of movements, and, therefore, the simplicity of the design of the machine and ease of setup.

 When grinding teeth, and especially wide wheels with an enlarged contact zone between the wheel and the workpiece, the cutting zone is interrupted, and despite the increase in cutting force, the heat stress of the process decreases and the conditions for supplying coolant to the cutting zone are improved. As a result, a toothless surface treatment of the teeth and an increase in the accuracy of tooth treatment are guaranteed. As a result, the possibility of the intensity of the process.

Claims (1)

 A grinding wheel attachment device for intermittent machining of wheels with a circular tooth, comprising a movable flange with a tapered bore and a clamping nut, characterized in that it is provided with a fixed casing with outer and inner tapered surfaces located in the tapered bore of the flange and a nut for securing the housing in the flange moreover, the cone angle of the outer surface of the housing is equal to the angle of the cone of the flange hole, while the axis of the conical outer surface of the housing and the axis of the conical hole of the flange are offset centrically with respect to the axis of the inner conical surface of the housing and to the axis of the outer surface of the flange by an equal amount.

Images