DE2442384A1 - THREAD GRINDING MACHINE WITH DEVICE FOR RE-GRINDING THE THREAD ON TAPS AND INTERNAL THREAD FORMERS - Google Patents

Description

DIpl.-lng. LudevWy

D / aj 1'J. 3.197 / 1 OiSi "" Γ ^ - ?. ^USO case 1973-1 / 158

»Ipl.-PhysT Mentzel

_ _A patent attorney

56 Wupp.rtal-Barmen

¹ M Tel. 553611/12

Reishauer AG, Limmatstrassa 87, 8031 Zurich, Switzerland.

Thread grinding machine with device for relief grinding of the Thread on taps and Innengswindsfarmsrn.

The invention relates to a thread grinding machine with a device for the relief grinding of the thread on the tapping surface and internal winch farmers with straight or helical flutes or rolled edges, in which the rotating workpiece, which is centric to the axis of the workpiece spindle, is clamped on the workpiece slide is, for the purpose of generating the desired thread pitch on the internal train on the workpiece slide radially adjustable grinding wheel is passed in the axial direction of the workpiece. ..

There are already various facilities for relief grinding of the thread on taps and internal thread formers known at

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which the relief grinding movements are carried out as follows:

a) by oscillating movements of the grinding wheel or the grinding carriage, which is guided in sliding or roller guides, in radial In the direction of the rotating workpiece that is shifting in its axial direction (see e.g. Swiss Patent Wr. 413 6 38 and P.R. Radin Praektirovanie i proizvodstvo reMus'fcego instrumenta, Kiev, 1963);

b) by .oszillierende pivoting movements of the grinding wheel or the Grinding spindle support around one mounted in the grinding slide Axis, in the radial direction in relation to the rotating workpiece and shifting in its axial direction (see e.g. German patent specification Wr. 1 210 710 and publication mentioned above by P.R. Rodin);

c) by oscillating swiveling movements of the workpiece or the workpiece support around an axis mounted in the workpiece slide, in the radial direction with respect to the "rotating grinding wheel" while the workpiece rotates and with the workpiece slide shifts in its axial direction (see e.g. German patent specification No. 467 997 and the aforementioned publication van Rodin);

d) by rotating the eccentric bearing bushes forwards and backwards the grinding spindle arranged in the grinding carriage, whereby the grinding wheel oscillating movements, in radial Direction in relation to the rotating and in its axial direction shifting workpiece (see e.g. German Patent Specification No. 1,274,011 and the referenced publication by Rodin);

e) by rotating the eccentric bearing bushes forwards and backwards for receiving the center points in the workpiece spindle and in the tailstock, through which the workpiece oscillates Movements in the radial direction in relation to the rotating one

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bciilsifschsibe be communicated while the workpiece is moving rotates and shifts in the axial direction (see z-.B. German Patent No. 520 27 / and the aforementioned publication vo.ι;? adin) j

f) only by swiveling the tailstock tip around a pivot point, which in the common; Axial plane of the grinding wheel and workpiece lies, wherein during the grinding the workpiece oscillating -Schwenkbewegungn with respect to the rotating Grinding wheel executes while the workpiece rotates and shifts in its axial direction (see e.g. German patent specification No. 530 990 and the aforementioned publication by Rodin). The creation of the relief according to this proposal is, however, fraught with a geometrical error, since the relief grinding movements are caused by oscillating swivel movements of the tool, which leads to flank angle errors leads on the thread profile.

In order to be able to use high speed grinding, i. of grinding with higher grinding wheel peripheral speeds (e.g. at 60 m / s) to be able to use the resulting advantages, the The peripheral speed of the workpiece can be brought into a favorable ratio to the peripheral speed of the grinding wheel. Around To be able to meet this requirement, the speed of the workpiece would have to be increased significantly compared to the previously usual conditions which, however, inevitably results in a correspondingly higher frequency of the 'workpiece speed and number of flutes (with Internal thread former, it is the number of roller edges) specified number Relief grinding movements required. All of the above in the sections below a - f, however, do not allow such large relief stroke frequencies because they are large Masses have to be moved back and forth over very short distances in very short periods of time, the sequence of which is to be carried out Movements is precisely prescribed.

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The present invention is based on the object of the relief grinding to increase the stroke frequency significantly compared to the previously usual or achievable values.

According to the invention, this is achieved in that the workpiece slide is designed in two parts and that the upper part carrying the workpiece by means of friction and wear-resistant guide elements guided on the lower part and can be set in an oscillating movement corresponding to the relief grinding movement by control elements is.

An exemplary embodiment of the dBr invention is shown in the drawing and described below in relation to the same. Only those are essential for an understanding of the invention Parts of the otherwise known thread grinding machines, for Part shown schematically. It shows :

Fig. 1 is a view of a thread grinding machine for taps and internal thread former,

FIG. 2 shows a section along the line II-II of FIG. 1 through the upper part, the lower part and the guidance of the lower part in the Stand,

2a shows a detail according to a variant in section,

3 shows a view of the upper part and the lower part (partially in section),

4 shows a plan view of the upper part (partly in section) a representation of the relief stroke setting,

5 shows an illustration of the relief grinding stroke setting at a relief stroke of the size zero,

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Fig. Ο a transmission diagram of a relief grinding device according to the invention,

Fiy. 7 a detail of the business scheme according to FIG. 6,

Fig. 3 is a schematic representation of the leaf spring connection of the Lower part with the upper part (representation of the spring preload),. ·

9 shows a tap with a relief-ground thread profile in Cross section and

1U shows an internal thread former in cross section.

The thread grinding machine shown schematically in FIG. 1 has a stand 1, which serves as the basis for the displaceable The workpiece slide, consisting of lower part 2 and upper part 3, and the grinding slide 4 are used. The delivery and Retraction device for the grinding carriage 4 with the grinding wheel 5 and the grinding wheel drive motor 6, as well as otherwise that relief grinding device according to the invention not influencing Elements of the thread grinding machine are "da" generally known. not specifically shown and mentioned.

On one end of the lower part 2 of the workpiece slide is the Workpiece gear box 7 arranged and firmly connected to it. The upper part 3 with the point bracket B fixed on it (Fig. 4) and the longitudinally displaceable tailstock 9 is connected to the lower part 2 via leaf springs 10 or leaf spring assemblies 11 (Fig »2a) in such a way that that a kind of quadrangle joint is formed (Fig. 2 and 8), whereby the upper part 3, under the action of means to be described later, in oscillating displacement movements, i.e. transversely to the Workpiece axis A (Fig. 2 and 4) running relief grinding movements can be moved. The transmission of the rotary motion from the non-oscillating Workpiece gear box 7 on the workpiece spindle

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in the top jaw 8, which oscillates together with the upper part 3, takes place via a commercially available coupling 13 (Fig. 6), which a transverse displacement (parallel displacement) of the axes to the extent of Back grinding stroke as allows.

The generation of the oscillating movements of the upper part 3 is with Accomplished with the help of an exchangeable cam disk 14 (Fig. 4), which is attached to the shaft 43 rotatably mounted in the lower part 2 and is driven by the workpiece gear box 7 (Fig. 6). To transfer the deflections caused by the cam disk 14 the upper part 3 is used by a rocking lever 15 (FIGS. 4 and 6) which is pivotably mounted in the lower part 2 on an axis of rotation 16 is. To set the desired relief grinding size or the stroke B of the upper part 3 between zero and a certain size value (Fig. 6, 8 - 10) is a template profile C (Fig. 4, 5), which in the example shown is arranged in the bore of a bush 17 rotatable in the rocker arm. The one in the lower part 2 swivels arranged rocker arm 15 is in permanent Kcaftschlüssiger Connection, on the one hand with the cam disk 14 and on the other hand with the sliding roller 19 mounted in the upper part 3 on an axis of rotation 18. The change in relief stroke B is achieved by changing the Lever arm ratio on the rocker arm 15 causes. It is created by changing the position of the template profile C in relation to the pivot point D of the rocker arm 15 brought about by rotating the bush 17 mounted in the rocker arm 15 with the template profile C. will. If the upper part 3 has a relief stroke of the size zero is to be achieved (Fig. 5), the stencil profile C must have a Represent circular arc section, the center point E (Fig. 4) by rotating the sleeve 17 with the pivot point D of the rocker arm 15 in Is to bring cover. The turning of the sleeve 17, which is on the outer cylinder with a payment. F is provided by turning of the pinion 20 which is in engagement with it. The setting of the desired Relief grinding hub B with the help of a zero line, .which is attached to the knob 21 of the pinion 20, and the associated Scalaring 22 made. In order to reduce the

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Bchleiss, a roller 23 is provided on the rocker arm 15, which continuously rests against the cam disk 14 without play.

The control elements 14, 15, 16, 17, 18, 19 and 23 for generating the oscillating movements of the upper part 3 are arranged and attached in such a way that the leaf springs 10 or leaf spring assemblies 11 are constantly in the same direction, for example to the left in FIG. 8 are deflected, and are consequently under a pretensioning force G always acting in the same direction. For this reason, the upper part 3 is continuously pressed against the lower part 2 via the aforementioned control elements by a rectified spring force H, ie by the reaction force to the pretensioning force G, within the entire relief grinding stroke range. Thanks to this arrangement, a constant, backlash-free, non-positive connection between the upper part 3, the aforementioned control elements located in between and the lower part 2 is ensured (FIGS. 4 and 5). The power flow is divided in the rocker arm 15 and is communicated to the lower part 2 in assigned proportions via the axis of rotation 16 and the cam disk 14 in accordance with the momentary size of the lever arm ratio. When setting a relief stroke B of the size zero, in which the lever arm ratio is also zero, the above-mentioned spring force H acts directly on the pivot point D of the rocker arm 15. The rocker arm 15 could lift off the cam disk 14 in this zero position. In order to prevent this, or to ensure the required operational reliability in the case of very small relief grinding strokes B, a compression spring 24 is arranged between the lower part 2 and the rocker arm 15. During relief grinding, the movements (retraction movements) of the upper part 3 leading away from the grinding wheel 5 are carried out exclusively by the spring force H (FIG. 8); the deflected leaf springs 10 or leaf spring assemblies 11 · effected, while the feed movements are inevitably communicated by the cam disk 14 to the upper part 3 via the rocker arm 15. The length of the decision between the upper and lower parts parallel to the workpiece axis arranged leaf springs or leaf spring packs \ speaks the length of the upper and lower parts, whereby a protection of:

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said control elements, consisting of cam, roller, rocker arm, Bushing, sliding roller and two rotary naps, is guaranteed against contamination.

The motor 25 (FIG. 1) which is attached to the workpiece gear box 7 is used to generate the rotary movement of the Viferk piece 26, the longitudinal displacement of the workpiece carriage, consisting of the lower part 2 and the upper part 3, and the rotary movement of the cam disk 14 or the oscillating movements of the upper part 3.

From the motor 25 (see Fig. 6) are on the shaft 27, the gear 28, the gear 29, the shaft 30, the change gear 31, the change gear 32 and the shaft 33 are driven. When grinding one Right-hand thread on workpiece 26 is driven by the shaft 33 from via the 5 sliding gear 34 connected therewith and the gear 35 engaged therewith onto the shaft 36 and from there via the transversely displaceable coupling 13, the workpiece spindle 12 in the top bracket 8, the drive plate 37 and the rotary heart 3B (Figure 4). With a left-hand thread, the sliding gear 34 is shifted to the right and with the ring gear I of the double gear 39, which is connected to the shaft 40, engaged. The drive The shaft 36 takes place under these conditions from the shaft 33 via the sliding gear 34, the ring gear I of the double gear 39 and its ring gear K on the gear 35, which is connected to the shaft 36. The latter and the one in the centering points 41 and 42 received workpiece 26 (FIG. 6) rotate in the opposite direction compared to the previous one.

The drive in the lower part 2 also takes place from the shaft 30 mounted shaft 43 on which the cam 14 is attached for generating the relief grinding stroke. Straight when sanding Grooved workpieces is the web 48 of the between the shafts 30 and 43 arranged differential gear with not shown Funds blocked. From the shaft 30, the rotary movement is transmitted to the shaft 43 via the gears 44, 45, 46 and 47. at

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under these conditions, the shaft 43 rotates at the same speed as

the wave 3D. - ■

3.- · ο '.j-2c! If,' i: IräüergetriEba, consisting of gears 31 and 32, is used to coordinate the speed ratio between the workpiece 26 and cam plate 14, with each flute or rolling edge on the to be ground workpiece 26 carried out a relief grinding movement must become. For the determination of the change wheels 31 and 32 are on the one hand, the number of flutes or rolled edges of the workpiece 26 to be ground, and on the other hand, the number on the circumference of the cam 14 existing integer replicas of the profile (Hubprafils) authoritative.

When grinding taps with helical flutes or internal thread formers with helical rolled edges of the cam disk 14, depending on the direction of the helical Spannuben or rolled edges, one of the longitudinal displacement of the Positive or negative additional rotary movement assigned to the workpiece slide, the size of which depends on the helix angle of the flutes or rolled edges is dependent. To generate the required additional rotary movement an adjustable ruler 49 (FIGS. 1 and 7) is used, which is attached to the stand 1 in an adjustable manner. Its angular position is selected according to the flute or rolled edge twist angle present on the workpiece 26 to be ground. One in the workpiece gear box 7 axially displaceably arranged feeler pin 50 slides on the mentioned ruler 49 when the workpiece slide, consisting of lower part 2 and upper part 3 "in the guide 51 of the Stand 1 longitudinally displaced (Fig. 2). The one from the oblique Ruler 49 caused axial displacement of the feeler pin 50 is " About the rack L to the ring gear H of the gear block'52 as Rotational movement communicated. The latter is rotatably mounted on the shaft 53 and has a second ring gear W on. Every turning movement on the gear block 52 is thus over the gear rim PJ, the gear rim ü of the gear wheel block placed loosely rotatably on the shaft 27 and from this via the gear ring P onto the gear wheel 55

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transfer. The latter is on the web 48 of the differential gearbench attached. As a result, the web 48 performs a rotary movement, which via the already mentioned gears 44, 45, 46 and 47 dun Di'f f orsntialgütrisbas, as an addition 'Jrehbswegun j, on dia.' ^ 1Ia 4 3 or the cam 14 fastened thereon is transmitted.

In addition, the shaft 33 is used to drive the Lead screw 56 or the longitudinal displacement of the workpiece slide, consisting of lower part 2 and upper part 3. The speed of the lead screw 56 is increased with the aid of the change gears 57, 58, 59 and 60 a mathematically precisely defined ratio is matched to the speed of rotation of the workpiece 26, so that the workpiece 26 to be ground the desired thread pitch is generated.

The non-positively arranged on the shaft 33 displaceable Sliding wheel block 61, comprising the ring gears Q and R, is moved to its left-hand position for grinding metric threads (Fig. 6) shifted, whereby its ring gear Q with the ring gear 5 of the loosely rotatably mounted on the shaft 30 wheel block 62 in engagement got. To grind threads with inch pitches, the mentioned sliding wheel block 61 is shifted to the right, whereby its Ring gear R comes into engagement with the ring gear T of the gear block 62. From the wheel block 62, its rotational movement is controlled by the ring gear U transferred to the gear 64 firmly connected to the shaft 63. The rotary movement is communicated from the shaft 63 to the lead screw 56 via the change gears 57, 58, 59 and 60 already mentioned. the The lead screw 56 itself is rotatable in the lower part 2 of the workpiece slide or in the workpiece gearbox 7 connected to it stored, but held axially. The one with a left-hand thread The lead screw 56 provided is screwed to the spindle nut 65, which is axially fixed on the stand 1 and secured against rotation. During the working stroke, i.e. the displacement of the '// piece slide' from left to right, the lead screw becomes 56-in the spindle nut 65 screwed in. For the return movement of the workpiece slide the direction of rotation of the motor 25 is changed. The leading

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The spindle 56 therefore unscrews itself from the spindle nut 65 and the workpiece slide moves from the right as a result to the left.

By choosing low-friction guide elements, such as Ulattfodern 10 or leaf spring assemblies 11, between the lower part 2 and the upper part 3, it is possible to work with much greater rear grinding stroke frequencies than has been possible up to now. This allows a significant increase in production output when grinding and relief grinding of the thread on threading tools, such as on taps and internal thread millers, for example. When using van low-friction, resilient Fuhxungselementen is possible thanks to the utilization of the spring force take-d to maintain a play-free _t-positive connection of the upper part 3 with the control members for the rear sliding movements in both directions of displacement by the guide members called "! A bias issued will.

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Claims (11)

• » ii 12 "- Claims Thread grinding machine with device for relief grinding of the thread on taps and internal thread formers with straight or helical chip flutes or rolled edges, in which the rotating workpiece, which is centric to the axis the workpiece spindle is clamped on the workpiece slide for the purpose of generating the desired thread pitch on the in relation is passed on the workpiece slide radially adjustable grinding wheel in the axial direction of the workpiece, thereby characterized in that the workpiece slide (2, 3) is designed in two parts and that the upper part (3) carrying the workpiece guided by means of low-friction and low-wear guide elements (10, 11) on the lower part (2) and by control elements (14-19 ». 23) can be set in an oscillating movement corresponding to the relief grinding movement. 2. grinding machine after; Claim 1, characterized in that the low-friction and low-wear guide elements through in the manner of a four-bar linkage between the lower and the upper part (2, 3) arranged leaf springs (10) or leaf spring packages (11) are formed. ' 3. Grinding machine according to claim 1 and claim 2, characterized in that that the leaf springs or leaf spring packages (10, 11) under the action of a pretensioning force constantly acting on them (G) stand. 4. Grinding machine according to claim 1 and claim 2, characterized in that that the length of the parallel to the workpiece axis (A) between the lower and upper part of the workpiece slide "(2, 3) arranged leaf springs or leaf spring bundles (10, 11) correspond to the length of the lower and upper part. 509813/0329 5. Grinding machine according to claim 1 and claim 2, characterized in that the control elements for the parallel displacement dos upper part (3) have an exchangeable cam disk * (14), one of them anlisganden, in the lower part (2) pivotably mounted rocker arm (15) and one in the upper part (3) rotatably ge superimposed, by the rocker arm (15) adjustable roller (15) include. - 6. Grinding machine according to claims 1, 2 and 5, characterized in that the rocker arm (15) rests against the cam disk (14) via a roller (23) rotatably mounted on it * 7. Grinding machine according to claims 1, 2 and 5, characterized in that an adjustable template (C) is arranged on the rocker arm (15), via which the rocker arm (15) rests against the sliding roller Ci9) " rotatably mounted in the upper part (3) for the purpose of being able to set the relief grinding stroke between the fourth garbage. and Binem predetermined limit value. 8. Grinding machine according to claims 1, 2, 5 and 7 » characterized in that the template (C) is in a vibrating ·. lever (15) rotatably mounted sleeve (17) is arranged. 9. Grinding machine according to claims 1, 2, 5, 7 and B, characterized. shows that the template (C) has a bulge protruding into the bore of the sleeve (17). ■ 1Q. Grinding machine according to claims 1, 2, 5 and 7-9, characterized in that; indicates that the bulge of the template (C) runs along an arc of a circle , the center point (E) of which coincides with the pivot point (D) of the rocker arm (15). 11. Grinding machine according to claims 1, 2, 5, 7 and 8, characterized thereby ; shows that the bushing has a toothing (F) with a pinion (20) adjustable by means of a rotary knob (21) in a j B0S813 / 0329 handle is, the rotary knob '(21) opposite a scale (22) adjustable for the purpose of setting the desired relief grinding stroke is. 609813/0329 Blank page