DE7610585U1 - DRIVE UNIT FOR THREADED TOOLS - Google Patents

Description

Iindenrnsier - ^Lind · ⁵ "™ '--- ^prezisipn0 ^ - ^{ernmf (07392)} - *

I. WerRU79K8 Lauphfeim "2." Telegraph 0719425

Lindenmaier - Präzision GmbH 7958 Laupheim-Untersulmetingen

Thread cutting unit

The innovation relates to an electro-mechanical thread cutting unit, as used for thread cutting and thread forming as a single unit or as a unit on mechanized production lines, rotary table systems and the like. Can be used.

The driving force is often provided by an electric motor, which executes clockwise and anticlockwise rotations in reversing operation. A simultaneous feed movement is achieved by the fact that the rotation of the Motor transmits to a spindle with an external thread and this spindle

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7610585 03/17/77

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Plant '■ / 968 Laupheim 2 Fnrnschrmbei ü / 19425

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can perform a screwing movement in a non-rotatable nut. the The thread pitch of the spindle and nut determine the feed rate of the spindle per revolution. Now becomes a tap or former with the spindle rigidly connected, this also carries out the screwing movement of the spindle. One uses this screwing movement to go into a pre-drilled hole To attach a thread to a workpiece, the thread pitches of the spindle and the threading tool must match. Deviations however, these gradients can be compensated for by keeping the spindle nut movable in the axial direction with the aid of springs.

So that different thread pitches are possible, the spindle made of 2 parts, the 2nd part with an external thread, referred to as guide cartridge, exchanged together with the nut, henceforth referred to as guide nut can be.

In a known device of this type, the rotary movement is now the Spindle simultaneously passed to an intermediate gear, which converts the maximum possible feed path of the spindle into an output shaft rotary movement of 300 converts. This output shaft carries cams which, as they rotate, actuate 2 electrical limit switches, one for the Reversing the electric motor from clockwise to counterclockwise rotation and the other is used to stop the spindle in the end position. The disadvantage of this The device is that the pitch compensation is not compensated for different pitches of the guide cartridge and threading tool and therefore an exact and simple setting of the thread depth is not possible.

In addition, the cams are only accessible after removing a cover which, in turn, takes a long time to set.

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⁷ BiUoBB 17.03.77

Lindonrr, diii? R Precision Gn, bll Fernruf (07392) "2021

Werk ι ■> 9 '. "- 8 i.nupheirn 2 telex 0719425 ,, O

In another known solution, the spindle is also in a Quill guided and connected parallel to the quill via a yoke. A shift rod actuates 2 limit switches for reversing via an adjustable cam of the motor. However, in addition to the great technical effort, this has the disadvantage that, due to the additional guidance of a shift rod, the quill guide, which is larger in diameter, and misalignment in the two guides, the friction is so great, a slope compensation using a spring is no longer sensible, since an excessive axial force can no longer achieve true-to-gauge threads. That's why it was here the mentioned slope compensation is dispensed with, which in turn leads to a limitation of the labor input. This solution also requires adjustment the thread depth is only possible by removing a housing cover and using a tool.

In the units mentioned, the switching devices are for reversing and monitoring housed in a separate control cabinet or must be housed in the control cabinet of the production line, which increases the mobility the thread unit when changing from a machine system or production line significantly restricts the other.

The innovation concerns a thread cutting unit with a clamping cylinder, a flanged switch box housing and a flanged one behind it Drive housing.

The clamping cylinder contains the ball bush bearing of the threaded spindle, which guarantees great ease of movement in the radial and axial direction. This makes it possible to compensate for the slope with the help of a compression spring between guide cartridge, guide nut on the one hand and threading tool on the other

3/17/77

and in connection with the roller guide in the spindle drive hub, as Axially smoothly displaceable coupling, to produce threads that are absolutely true to gauge, even if the gradients of the guide cartridge and the tool differ from each other.

The flanged switch box contains the for the reversing operation of the Motor required electrical switching devices, an overload protection device and a program plug.

By exchanging the program plug, the unit can be used both for Right-hand thread as well as left-hand thread can be used.

Manual switching can be carried out using 2 buttons. For the automatic process it is sufficient to switch through a circuit led out of the switch box with the help of a normally open contact (electrical switching contact, which when actuated closes the circuit).

There are 2 threaded spindles on the clamping cylinder side of the switch box, with their help 1 limit switch each for the front end of the stroke and one for the rear end of the stroke can be adjusted in the axial direction. The distance between the two limit switches determines the stroke of the unit, the actuation by the non-rotating switching cam takes place directly from the spindle without an intermediate link.

The stroke adjustment with the two threaded spindles is without tools possible and accessible from the outside, which increases the user-friendliness and shortens the setting time.

As a rule, the dimensions of the threaded rings are far below of the total stroke of the unit. As a result of this, the thread length range can be adjusted by simply adjusting the two threaded spindles via the The entire stroke range of the unit can be moved axially. It is therefore not necessary to use the entire unit for minor changes in the position of the workpiece to adjust.

The drive housing is flanged to the rear of the switch box housing. This contains the components required to generate the rotation as well as the feed movement.

A flange-mounted electric motor is via a toothed belt or a chain transfers the torque of the motor directly to a hollow spindle shaft in order to keep the centrifugal masses for the reversing operation small. This hollow shaft in turn transmits the rotary movement by means of a roller guide both on the work spindle and on the lead screw, thereby the lead screw is screwed out of the radially fixed lead nut and presses the work spindle against the spring in the clamping cylinder and switch box forward. The axial reaction force is arranged radially by 2 to 6 Compression springs taken from the lead nut housing, which is firmly connected to the drive housing by means of a knurled screw.

The reaction force can be influenced by the number of compression springs. This, in turn, is decisive as to whether the guide nut is affected by the axial thrust that occurs when the threading tool is cut or not axially to the rear. If it does, the built-in limit switch is actuated and the motor is reversed., This built-in safety

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? 81ü53o 03/17/77

circuit has the advantage that if the threading tool or a non-existent core hole the mechanics cannot be damaged and an axial overload is excluded.

A variation of the reaction force is always advantageous when existing threads are to be reworked. Here the first workpiece thread can be found by applying slight axial pressure without damaging the same.

Another advantage is that with small tool cross-sections the buckling caused by the axial thrust force can be limited so that when the threading tool hits a workpiece Without a core hole, the tool cannot break at all.

If the lead screw stock without rapid traverse is compared to one with rapid traverse exchanged, the area of application of the unit can be expanded significantly because infeed movements can be bridged in a very short time and this saves working time.

For this purpose, the lead screw is a pneumatic and hydraulic cylinder designed and the piston designed so that it takes the lead nut and lead cartridge in its feed movement and these on the work spindle execute a rapid feed movement. The control takes place via a normal 4/2-way valve.

A very special advantage is that the headstock without Rapid traverse can be exchanged for one with rapid traverse at any time

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can without additional renovation work being necessary. The loosening A single knurled screw is sufficient to exchange the Loit headstocks.

Replacing the guide nut and guide cartridge is just as easy. A screw with a conical head holds the guide nut axially and radially in the radially immovable guide nut housing (or cylinder cover). The screw is attached so that part of the tapered bore is in the guide nut and the other part is in the guide nut housing (or cylinder cover). If the screw is now screwed tight, the axial and radial play of the two parts to be joined is completely eliminated, due to the cone, with the thread in the guide nut housing against c ^l! tapered bore in the guide nut is clamped.

As a rule, when changing the thread pitch, the speed, due to the desire for optimal cutting speed. For this purpose, the drive housing can be separated from the rest of the unit be removed. You only need 2 clamping screws in each other diagonally opposite pillars can be easily loosened and the drive housing can be easily pulled off over the two pillars. Now the two pulleys or sprockets can be exchanged. The column guide enables the actuator housing and switch box as well as the lead screw and hollow shaft to be joined easily.

Finally, it should be noted that the selected cylindrical shape of the clamping cylinder makes it possible to move the unit axially steplessly with a simple clamping piece and also steplessly 360 around the To twist cylinder axis.

With a swivel clamp with the swivel axis perpendicular to the cylinder axis, can graze with the unit any spatial situation achieved.

The innovation will now be explained in more detail with reference to the drawing. Show it;

1 shows a longitudinal section through a thread cutting unit according to the invention without rapid traverse device

FIG. 2 half view from the left, half section along the line I - I, FIG. 1

3 shows a section along the line II-II, FIG. 2

FIG. 4 shows a section along the line III - III, FIG. 1

FIG. 5 shows a section along the line IV - IV, FIG. 1

Fig. 6 is a longitudinal section through part of the drive housing of a Thread cutting unit according to the invention with rapid traverse control

7 shows an electrical circuit diagram (illustration without rapid traverse device).

According to the illustration are a clamping cylinder 1, a switch box housing 2 and a drive housing 3 flanged one behind the other. The clamping cylinder is attached to the switch box housing with screws 4. The The drive housing 3 is clamped to the switch box housing 2 by means of two diagonally opposite bolts 5, FIG. 2. The bolts 5, Fig. 5, are pressed into the drive housing 3 and each

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dowel pin 6 secured.

The conical shape at one end of the bolt 5 ensures a safe Join when the switch box housing 2 and drive housing are plugged together 3 after dismantling or after changing a wheel. By means of a conically turned threaded pin 7 in the conical part of the Bolts 5 are pressed into holes 8 balls 9 by turning the threaded pin outward and spread the spring ring 10 so that between Bolt and hole create a secure clamping effect. The clamping occurs already after a fraction of the revolution.

In the clamping cylinder 1, Fig. 1, the work spindle Π is mounted by means of a spherical bushing 12, held by a perforated nut 13, which clamps a locking ring 14, embedded in the diameter of the spherical bushing, flat against a shoulder in the clamping cylinder. The ball bushing allows both radial and axial movement of the spindle. D ^c oindelkopf is generally provided with a drill chuck according to DIN 238 or a spindle head DIN 55,058th A flange on the spindle head to accommodate multi-spindle heads is also possible.

On the back of the ball socket there is a spring sleeve 15, this one opposite a spring sleeve 16; both are pressed apart by the compression spring 17. The spring sleeve 16 is pressed into a switch stop 18. The switching stop 18 is rotatably mounted on the spindle 11 by the ball bearing 19. Two retaining rings 20 fix the ball bearing the spindle. The rotation lock for the switch stop is provided by the bolt 21, which is screwed to the flange of the clamping cylinder. the Switching stop slides with a semicircular groove on the circumference, along the

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761C535 3/17/77

Bolt 21 and thus only performs an axial movement.

The switch stop actuates 2 limit switches 22 ν and 22 h (Fig. 1 and Fig. 7), which are screwed with 2 screws 23 each to the guide block 24, Fig. 2 and 3, and the guide block 25, Fig. 3. The limit switch on the guide block 24 triggers the electrical switching process in the rear end position, the limit switch on the guide block 25 in the front End position of the spindle.

The guide blocks 24 and 25 are attached to the flange of the clamping cylinder guided screwed guide pin 26 and secured against rotation. The threaded spindles 27 and 28, provided with scales and knurled heads, serve to adjust the length of guide block 24 or 25. If the barrel head is turned, the threaded spindle is screwed into the Mutating thread of the guide block and moves it in the longitudinal direction, on the one hand due to the fact that the guide block secured against rotation cannot rotate, on the other hand due to the fact that the threaded spindle can not move axially. Therefore, lead screws 27 and 28 slide in each a bearing bush 29, which is held by a screw 30 in the switch box housing. A locking ring 31 on the lead screw and 2 bearing washers 32 on the end faces of the bearing bush fix the threaded spindle in the axial direction and at the same time take a rotary movement.

Against independent twisting and penetration of dirt and coolant is secured by an O-ring made of nitrile rubber 33, which is pretensioned accordingly sits in a groove in the bushing and creates a vibration-proof holding torque through friction between the threaded spindle and bushing.

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761G535 03/17/77

LirvJennaie: -Precision ümtH Fernruf (07392) "2921 Werk I ■ 7 ^c ! O8 Laupneim 2 telegraph 0719425

The socket head screws 34 and 35 prevent the threaded spindle are rotated too far out of the guide blocks and at the same time form the end stop of the limit switches for the front and rear circuit-wise End position of the work spindle.

A mounting plate 36, Fig. 1, screwed tightly inside the switch box housing, carries the electrical components required to control the unit, Fig. 1 and Fig. 7, 2 switching protection 37a and 37b, 1 trigger device for PTC thermistors 38, 1 program plug socket 39, 1 program plug 40, 2 pushbuttons 41 and 42 for manual operation, 1 terminal strip 43. The The switch box housing is secured by a plate 44 covered. It serves as protection against contact with the current-carrying components when the switch box housing and drive housing are separated.

The drive housing carrying a screw from the housing interior forth flange 45, Fig. 1. On the motor shaft is seated the hollow shaft 46, on this, the drive wheel 47 with key 48. Secured wira the drive wheel with the ring nut 49 and the securing plate 50.

The rotary motor movement is transmitted to the output gear 52 via a toothed belt 51 or chain. This wheel is seated on the hollow shaft 53 and is held on the key member 54, the retaining ring 55 and the ring nut, the hollow shaft is rotatably supported in the bearing housing 57, which is flanged to the drive housing by means of screws 58 through the RS-ball bearings 59th In the hollow shaft bore 4 needle bearings 60, Fig. 4, for longitudinal movement, held by spring wires 61, housed, which allow easy axial displacement of the work spindle with respect to the hollow shaft,

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3/7/77

even if the full motor torque is taken from the work spindle will. A felt ring 62, Fig. 1, at the end of the spindle, seals the lubrication space 63 from the work spindle and its storage.

Due to the axial thrust exerted by the compression spring 17, the Work spindle constantly on the guide cartridge 64. Is the pitch of the threading tool larger than that of the pilot cartridge, the spindle and pilot cartridge separate at the point of contact and come at the end of the return together again.

The guide cartridge has the same milling on both sides as the work spindle.

Half of the 4 needle bearings in the hollow shaft bore form the guide and radial drive of the work spindle and the other half of the guide cartridge. During operation, the guide cartridge 64 is constantly screwed into and out of the guide nut 65.

The unit is identical to a threading unit up to this point without rapid traverse and one with rapid traverse.

First, consider the unit without rapid traverse (Fig. 1):

A cylinder 66 is fixed in the drive housing by the knurled screw 67. The guide nut housing 68 is axially supported against the cylinder base by a compression spring 69. Two grooves 70 offset by 180 are guided by tabs 71 of the hollow shaft bearing housing 57 and secure against rotation in the case of axial mobility.

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7 61 ü o 3 5 03/17/77

The Lettnut 05 is made radially and axially by the conical head screw 72 held and clamped backlash-free with the lead nut housing.

If the work spindle receives an axial thrust which overcomes the springs 69, which are available in optional numbers of two, three, four or six, an electrical limit switch 73, FIGS and this is held axially by a locking ring 75. The receiving bushing remains radially rotatable. A screw plug 76 connects the limit switch via the cable 77 to the electrical components in the switch box housing. The actuation of the limit switch 73 causes the motor to reverse and the work spindle to return to its starting position.

In addition to normal operation without rapid traverse, the thread cutting unit can can also be operated with a rapid feed, Fig. 6.

For this purpose, the cylinder 66, Fig. 1, after loosening the knurled screw 67, removed from the drive housing and exchanged for a cylinder 66a, FIG. 6. In this cylinder, the guide nut 65 is through the The conical head screw 72 is braced with a guide nut housing which carries an air piston 79 axially fixed by two retaining rings 78. The O-ring 80, as well as the O-ring 81 in connection with the sliding ring 82 are used for sealing. A screwed-in cylinder cover 83 closes the cylinder space to the front, and a movable cylinder cover 84 to the rear. The seal kit 85 seals the front cylinder space, a set of seals 86 and an O-ring 87 seals the rear cylinder space. With two air connections 88 and 89, the rear cylinder space and the front cylinder space can be supplied with compressed air or liquid.

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7810535 03/17/77

The print medium is preferably reversed by a 4/2-way egg ektromagne * venti I, which is activated with the switch-on pulse, and the pressure medium steers to the rear of the cylinder. This causes pistons and thus also slotted nut housing, guide nut and guide cartridge in the axial direction until the piston 79 hits the cylinder cover 83.

The work spindle lying on the front side of the lead cartridge and with it the Tools clamped on the head of the work spindle must also take over this feed movement. This egg! Feed movement is there With the switch-on pulse, the electric motor is switched on at the same time, the screwing movement of the guide cartridge is superimposed and the speed reinforced. After the thread depth has been reached, the motor is reversed via the front limit switch 22 ν after the rear limit switch has been actuated 22 h the engine is stopped and at the same time the solenoid valve is reversed and with it the medium in the two cylinder chambers. The spindle returns to its starting position in rapid traverse. Through this circuit is ensures that the reverse rapid traverse only starts when the tool no longer has contact with the workpiece.

As in the first-described embodiment without rapid traverse, the torque on the guide nut housing is absorbed by the grooves 70a and the tabs 71 of the hollow shaft bearing housing 57 with axial mobility. Unintentional actuation of the limit switch 73 is counteracted by the compression springs 69, which are available in optional numbers. Their total pressure force must be greater than the reaction force exerted by the movable cylinder cover, caused by the pressure in the cylinder. Limiting the medium pressure by means of a pressure reducing valve, however, provides a further possibility of coordinating the forces with one another.

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761053b 03/17/77

Claims (1)

1. Drive unit for a thread cutter or thread former, with an axially and rotatably movable work spindle that supports the interchangeable threading tool and which over a guide cartridge interacting with a guide nut for an axial screwing movement by means of limit switches can be driven for a reversing operation controlled electric motor, the received by a master nut housing Guide nut is axially movable and is resiliently supported on one side, characterized in that the work spindle (11) in one on a switch box housing (2) flanged clamping cylinder (1) is received and on her in the switch box housing (2) reaching end one for actuation of the two in this housing together with all for limit switches (22h, 22v) during the axial movement of the work spindle (11) carries a switching stop (18), the two limit switches (22h, 22v) via a respective adjusting spindle (27, 28) from outside the switch box housing (2) into different Axial positions relative to the work spindle (11) are adjustable and the guide nut (65), the Guide nut housing (68) and the guide cartridge (64) in one The drive housing (3) also flanged to the switch box housing (2) are arranged. 2. Drive unit according to claim 1, characterized in that the work spindle (11) has a Ball guide (12) supported on the clamping cylinder (1) 761C- 5 d b 3/17/77 - 16 - - ^Ί6 -; and by a long compression spring (17) against the guide cartridge (64) is pre-tensioned via an in the drive housing (3) mounted and connected to the coaxial guide cartridge (64) via axially movable needle bearings (60) (53) is driven by the electric motor (45) flanged to the drive housing (3). 3. Drive unit according to claim 1 or 2, characterized in that g e k e η η shows that the guide nut (65) is axially fixed to the interchangeable by means of a conical head screw (72) Insert cylinder (66, 66a) of the drive housing (3) for a relative non-rotatable axial movement guided and is connected by a selectable number of compression springs (69) resiliently supported guide nut housing (68), wherein im relative axial displacement of the guide nut housing (68) a further limit switch (73) for further control of the reversing operation of the electric motor in a Exceeding a limit load determined by the compression springs (69) is arranged. 4. Drive unit according to one of claims 1 to 3 »thereby characterized in that the guide nut housing (68) is rigidly connected to a pressure piston (79) which is in one through the insert cylinder (66a) and the guide nut housing (68) and one via the compression springs (69) on the insert cylinder supported, axially movable cylinder cover (64) and one axially immovable at an axial distance from this arranged cylinder cover (83) formed, pneumatic or hydraulic pressure chamber is movable. 5. Drive unit according to one of claims 1 to 4, characterized in that the drive housing (3) is connected to the switch box housing (2) via two column guides parallel to the work spindle (11), wherein each guide column (5) fixed to the drive housing (3) in an assigned guide hole of the switch box 35 3/17/77 ' ¹⁷ ' stengehäuses (2) bordering end is provided with a transverse to the column axis aligned bore (8) into which balls that can be driven out radially through the conical tip of a threaded pin (7) that can be moved in the column axis (9) for spreading a guide column (5) that jams in its guide hole in the switch box housing (2) slotted ring (10) made of resilient material are used. 3/17/77