DE1258671B - Guide device - Google Patents

Description

FEDERAL REPUBLIC OF GERMANY

GERMAN

PATENT OFFICE

EDITORIAL

Int. CL:

Number:
File number:
Registration date:
Display day:

F16c

German KL: 47 B-31

1258 671
N22981Xn / 47b
March 26, 1963
January 11, 1968

The invention relates to a guide device with a guide and one opposite to it leading bodies and means by which between the facing, cooperating Guide surfaces a gas cushion is generated. In 5 of such a known guide device the guide surfaces are separated from each other by a gas cushion. The occurring Frictional forces between the guide surfaces are practically negligible, so that the parts of the device can be easily moved against each other. The gas cushion, the strength of which is practically appropriate Can have a value of about 10 μ, has the further advantage that the guide surfaces are practically not contaminated will.

Especially with precision tools, e.g. B. tool devices, the strength of the gas cushion should be as possible be kept constant. For this purpose, z. B. with horizontally arranged guides the movable on the guide, z. B. on a layer of air stored body with a certain Weight are loaded so that the gas cushion is pretensioned as it were. By running the Guide device the total weight of the body pressing on the gas cushion in relation to the respective Load difference of z. B. a chisel connected to the body to be guided large is chosen, this is quite achievable. In practice, however, this requires proportionally heavy weight loads, as a practical example it should be mentioned that the gas cushion with a mass must be pretensioned by about 100 kg in order to increase the strength when the load changes by 1 kg to keep the gas cushion constant at a practically acceptable value.

A disadvantage of the pretensioning of the gas cushion by a weight is that in certain Cases required weight loads a deflection of the guide z. B. one at some Can cause points supported guideway. It is also a disadvantage that a gas cushion pretensioned by weight load only with guide devices arranged approximately horizontally can be. If the guide surfaces are in a position that deviates significantly from the horizontal position take, this solution is therefore less practical. Another disadvantage is that large weight loads to pretension the gas cushion to relatively high inertia forces at z. B. lead rapidly moving parts.

The invention aims to provide a guide device

Applicant:

N. V. Philips' Gloeilampenfabrieken,

Eindhoven (Netherlands)

Representative:

Dipl.-Ing. H. Zoepke, patent attorney,

8000 Munich, Ridlerstr. 37

Named as inventor:

Jacob Koorneef, Eindhoven (Netherlands);

Simon Duinker, 2000 Hamburg;

George Ludwig Walther,

Eindhoven (Netherlands)

Claimed priority:

Netherlands of March 28, 1962 (276 532)

to create which does not have the disadvantages mentioned.

The guide device according to the invention is characterized in that at least one of the mutually movable parts of the same is provided with one or more magnets, which these Part and the at least partially ferromagnetic other part of the guide device including of the gas cushion together. In this device, the gas cushion is thus activated by the magnets biased. Despite the low weight of the magnets, a pretensioning force can be applied in this way the required size. The attachment of the magnets also results in independence the position of the guide, as these magnets are the mutually moving parts of the device, Regardless of the position of the guide surfaces, always pull together. It has also been found that the Attaching the magnets brings with it the possibility, fast, from the outside in the device to dampen the vibrations caused by the eddy currents generated by the magnets. Another Advantage of using magnets to generate the necessary preload forces when Gas cushion is that relatively light constructions are sufficient. You can be a crowded one Have construction so that they can be used advantageously in precision tools where

709 718/216

the factor of the available space plays an essential role.

The above-described principle of prestressing the gas cushion by magnets can be used with many Perform guide devices in which the guide surfaces can be rotated against each other or are also arranged displaceably along a straight or curved path. The guide surfaces can be curved or flat.

Even though magnets and their attractive effect on opposing parts have been known for a long time, it is a new finding that in a guide device with a guide and a movable body to be guided opposite it and with guide surfaces separated by a gas cushion The desired pretensioning of the gas bag and the keeping of this gas bag constant by the magnetic force of attraction is achieved by a weight load. So here are magnets: ivc. For a new type of use, a design is preferred in which the Mazur to achieve a new type of effect for use, are housed in the smaller of the guide surfaces.

The invention is explained in more detail below with reference to the drawing, some of the execution part to use it shows its novel use- 25 examples. In the drawing shows the magnets make it possible to achieve great results. 1 schematically shows the most important parts of a

clamping forces with a small weight of the parts, which would otherwise be in proportion to the change in the The force applied to guide surfaces, e.g. a chisel load, are large. It can too. Magnets used whose preload force can be lower if a further design of the device is used according to the invention, which is characterized in that the magnets by electromagnets are formed and that means are provided by which the strength of the gas cushion between interacting guide surfaces can be measured while continuing a control mechanism it is provided that the excitation current of the electromagnets when the measured strength changes regulates.

Although the magnets, which can be permanent magnets or electromagnets, in one or both mutually movable parts of the guide device can be accommodated is to achieve stable mutual movement of the leading

although use is made of the attraction peculiar to magnets, but without them to be attached to one another as a fixative

would only be achievable with heavy weights with the associated disadvantages.

The strength of the gas cushion can be varied Keep wise completely or almost constant; it can be the magnetic biasing force for example to said chisel force, about 100: 1, can be selected; the guide surfaces can also have a enclose the same angle with each other; but it can also when using electromagnets and a control device, the magnetic effect on the gas cushion by changing the excitation current the electromagnet can be controlled. : According to a further embodiment of the guide device according to the invention, in which the guide is formed by a guide track, are in this Two guideway enclosing an angle with one another Contain guide surfaces that correspond to two, an equal angle with each other enclosing guide surfaces of the body which is movable with respect to the guide cooperate, with further magnets are arranged in at least one of the mutually movable parts, which the pull together corresponding, interacting guide surfaces including the gas cushion. In this case, two guide surfaces enclosing an angle with one another are sufficient both on the body and on the guideway. In contrast to those for rail guiding devices for precision tools common, relatively expensive dovetail guides this type of construction can be produced cheaply. When the two guide surfaces that form an angle with one another z. B. be formed by a horizontal and an upright guide surface, needs this construction thus no additional guide surface in an upright position to have around the part to be guided not only in the vertical direction, but also in the horizontal direction, 6s conclude. -. ■. · "■

As already mentioned, pre-tensioning forces can be used to ensure a constant strength of the gas cushion known guide device in which a gas cushion is generated between the guide surfaces;

F i g. FIG. 2 shows an arrangement similar to FIG. 1, but provided with magnets according to the invention is;

Figs. 3 and 4 show a plan view and a Section along the line IV-IV in F i g. 3 a straight guide according to the invention;

Fig. 5 shows a variant of the arrangement according to FIG. 3, which has a guide device with a curved Owns guideway;

FIGS. 6 and 7 show some stages in the production of the straight-line guide according to FIGS. 3 and 4;

F i g. 8 and 9 show a straight line guide in which a long slide over two separate guide track parts is movable. F i g. 8 shows schematically a plan view, and FIG. 9 shows a section along FIG Line DC-IX in Fig. 8th;

F i g. 10 shows a section according to FIG. 4, but rotated over 180 ° in the plane of the drawing;

F i g. 11 shows an embodiment with an electromagnet, the excitation current of which can be regulated. In Fig. 1 are of the guide device, the stationary guide with 1 and one opposite movable body designated by 3. The mutually movable parts face each other , Guide surfaces 5 and 7. The body 3, e.g. is formed by a chisel mount of a tool device, is with a number of the supply one Provided overpressure gas (arrow 9) connected channels 11. Through these channels 11 that are in the guide surface? open out, an air flow between the guide surfaces 5 and 7 can be maintained ,will. The gas flow can escape in the direction of arrows 15 and 17. The arrangement is such that the guide surfaces are separated by the gas cushion, while the body 3 is on the gas cushion comes to the plant. This storage on a gas cushion with a practically useful strength from Z. B. 10 μ can be used when the guide surfaces 5 and 7 move against each other or are to be rotated and then the at the

mutual movement occurring frictional forces are minimal.

In this type of guide device, by appropriate selection of the weight of the body 3 pressing on the gas cushion, which can optionally be provided with an additional weight, this gas cushion is pretensioned in such a way that when the magnitude of the chiselling force P changes, the strength of the gas cushion remains practically constant . It applies here that the higher the pretensioning force in relation to the change Δ P in the chisel force P , the more constant is the strength of the air cushion. In practice, the gas cushion is z. B. biased by a mass of 100 kg in order to keep the strength of the gas cushion constant with a change of 1 kg. In these constructions, it is generally necessary to load the body 3 with a large weight. These constructions have various disadvantages, since such large weights also affect the guide surface located below the gas cushion; this is therefore less suitable for use as a guide surface for guideway systems that have a relatively long guide that is only supported at a few points. In this case, the guide can bend considerably. Another disadvantage is that these heavy bodies have to be accelerated or decelerated during movement, so that considerable inertial forces have to be taken into account.

By applying the required preload force to at least one of the parts that move in relation to one another housed magnet is removed, there is the possibility of a pretensioning force of the required To achieve size, despite the low weight of the magnets (Fig. 2). The one with gas ducts provided body 23 according to FIG. 2 made of non-magnetic material has a number of magnets 25. The guide is made of ferromagnetic material. The magnets pull the mutually facing guide surfaces together. By choosing the right type and the number of magnets, which of course can also be accommodated in the guide 27, there is the possibility of using the gas cushion between the guide surfaces as desired to pretension. The magnets, which can be permanent magnets or electromagnets, create one great adhesive strength between the guide surfaces. Since the usual known type of construction for this purpose Magnets does not constitute a special subject of the invention, this type of construction is not explained further here.

It has been shown that rapid external vibrations exerted on the body are practically complete Can be dampened by the eddy currents induced by the magnets.

Since the biasing force is taken from the magnet, the invention can be advantageous for guide surfaces perform that are not horizontal. Regardless of the position of the guide surfaces, practice the magnets exert the required pretensioning force on the gas cushion.

The invention is particularly suitable for use in guide devices in which the body to be guided must be movable along a precisely defined path. The F i g. 3 and 4 show a Example of such a leadership. It contains a guide track 31 made of ferromagnetic material and a body 33 which can be displaced back and forth over this guideway. The body 33, the length of which seen in the feed direction, in relation to the length of the guide track 31 is small, is made of non-magnetic material and contains magnets 35 and 37 and is further provided with a number of channels which face the guide track 31 and are connected to a compressed air supply in the manner shown. The body 33 contains two ones Guiding surfaces 41 and 43 enclosing certain angles with one another, which are at an equal angle mutually enclosing guide surfaces 45 and 47 cooperate. Both between the surfaces 41 and 45 as well as between the surfaces 43 and 47 there is a pretensioned air cushion. In this way, straight guidance is obtained which, in contrast to that for precise guidance known dovetail guides only requires two guide surfaces enclosing an angle. The magnets hold the lead Body 33 with the interposition of a pre-tensioned air cushion between the two sets of Guide surfaces in its place in the path to be followed. This path is straight in this case, but it can also be curved (Fig. 5).

The straight line according to the F i g. 3 and 4 can be produced in a particularly simple manner (see FIGS. 6 and 7). A body 53, ground flat on one side and provided with magnets 51 and 52, adheres to a block 55 made of ferromagnetic material, which is also ground flat on one side. Then the surfaces marked 57 and 59 are ground flat in a single operation, it need not be taken into account that the angle χ (Fig. 7) is 90 °. Then an individual part 61, which is also ground flat on one side, is screwed to the block 55, whereupon the straight-line guide is finished.

The F i g. 8 and 9 show a straight line guide in which the guide track is formed by two stationary, angled parts 63 and 65, which together guide a long slide 67. The parts 63 and 65 are provided with magnets 68 and 69 and with channels through which compressed air is supplied in the direction of the arrows indicated by dashed lines 71, the carriage 67 being made of ferromagnetic material. The carriage 67 is therefore not provided with magnets.

In the guide device according to FIG. 3 and FIG. 4, the angled guideway 31 at least partially forms the stationary part below the guide device. This device can also be reversed so that the position after F i g. 10 is obtained. In this position, the body 33 could move out of the guideway due to its own weight 31 fall, but the magnets in the body 33 prevent this and also provide the pre-tensioning force for the gas cushion between the guide surfaces.

In the design according to FIGS. 2, 3, 4, 5, 8, 9 and 10, the magnets should be similar to the channels facing the guide surfaces, preferably in the smaller of the interacting guide surfaces can be accommodated. It has been found that this results in a very stable leadership. If, on the other hand, the magnets are in the larger of the interacting Guide surfaces are attached, a satisfactory stability could only thereby can be achieved by the guideway with a large number regularly over the entire guide

Magnets distributed over a wide area are provided with completely identical magnetic properties.

In order to ensure a constant strength of the gas cushion, as stated, magnets can be used which supply a pretensioning force which is large in relation to the change in the external loading force P. By using electromagnets, it is possible to apply a relatively lower preload force with the same difference in the external load. When a change AP occurs in the loading force, for example a chisel, increases, e.g. B. the strength d of the gas cushion. By now measuring this strength and, if the measurement result changes, the electromagnets are controlled in such a way that the adhesive force decreases, the strength of the gas cushion can be kept constant. An arrangement shown schematically in FIG. 11 has a movable body 77 provided with an electromagnet 75 and a guide 79. Means are also present in the usual manner by which the instantaneous thickness d of the air cushion can be measured, part of the guide surfaces acts as part of a variable capacitor. By means of a control element 81, a measured difference in the strength of the air cushion is converted into a change in the excitation current of the electromagnet 75.

Claims (5)

Patent claims: 1. Guide device with a guide and one of these relative to movable to be guided Body and means through which a gas cushion between the facing, interacting Guide surfaces is maintained, characterized in that at least one of the mutually movable parts this guide device is provided with one or more magnets that hold this part and including the at least partially ferromagnetic other part of the guide device of the gas cushion magnetically pull together. 2. Guide device, in which the mutually movable parts are formed according to claim 1 are and the guide is formed by a guide track, characterized in that the guideway contains two funnel surfaces enclosing an angle with each other two corresponding guide surfaces of the to cooperate with respect to the guide movable body, wherein in at least one of the mutually moving parts magnets are attached, which correspond to each other pull cooperating guide surfaces together with the inclusion of a gas cushion. 3. Guide device according to claim 1 or 2, characterized in that the magnets are electromagnets and that means are provided are, through which the strength of the gas cushion between interacting Fünrungsflächen can be measured, and that a control mechanism is available that changes the measured Strength regulates the excitation current of the electromagnet. 4. Guide device according to one or more of the preceding claims, characterized characterized in that the magnets in the smaller of the interacting Fünrungsflächen are housed. 5. One of the parts of the guide device according to one of the preceding claims, characterized characterized in that this part with a number is connected to the supply of a positive pressure gas subsequent channels is provided in the guide surface or in the guide surfaces this part open out, and that further arranged in or near this guide surface or these guide surfaces one or more magnets are. Considered publications:
German Auslegeschrift No. 1008 966;
Swiss patents No. 345 509,
331637. 1 sheet of drawings 709 718/216 12.67 © Bundesdruckerei Berlin