DE2808680A1 - GUIDE ELEMENT, IN PARTICULAR DRILL INSERT OR THE SAME, AND PROCESS FOR ITS PRODUCTION - Google Patents

Description

HÖGER - LEGAL RIGHTS - GRIESSBACH - HAECKER

A 42 754 b Applicant: Edward J. Voitas

k- 163 59 De Gray Terrace

February 27, 1978 Mawah, New Jersey 07401

United States

description

Guide element, in particular drill bit or the like, and method for its Manufacturing

The invention relates to a guide element, in particular a drill bit or the like, for precise mutual alignment of relatively movable, mutually supporting surfaces, one of which is a surface of the guide element and the other is a surface of a component supported thereon, as well as a method its manufacture.

The invention is concerned with guide elements such as drill bits as used in industry and are normally provided with deep drilling devices and with methods for producing such guide elements,

Drill bits are used to ensure that a hole drilled in a workpiece is a precisely defined one Position in relation to a fixed reference point or in relation to another opening or a pattern of openings having. This reference point is used to accurately locate a pattern of openings in a workpiece or Maintain component, this pattern during a

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long operating phase in which such components are manufactured should be exactly reproducible. In order to ensure the required accuracy or tight tolerances, it is required to guide the drill with very tight tolerances and these tolerances during the entire production process maintain. This is done with the help of guide elements according to the invention, in particular by means of the invention Drill bits, achieved.

Known drill bits are generally made from high carbon steel or steel alloys, which have been subjected to heat treatment to improve their hardness. Ensure such drill bits a proper drill guide during its service life. On the other hand, their lifespan is relatively short because the metal they are made of has limited wear resistance. Attempts have therefore been made to improve wear and tear by using high-speed steels made from various special alloys. Such However, drill bits are much more expensive than the usual drill bits and their life expectancy is lower Still much to be desired, for example when they are used when drilling materials that contain asbestos or contain other abrasives, such as those found in cast iron.

In other cases in which the life expectancy in a production process is the decisive criterion, in industry has also worked with drill bits made entirely of tungsten carbide. These drill bits,

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which are usually solid over their entire cross-section, have several disadvantages. The first and most important drawback is that the cost of such a drill bit is 10 to 20 times that of a drill bit made of high speed steel. Second, tungsten carbide bits are brittle and are often used when they are installed in the drilling apparatus damaged or cut by the tool itself. Various attempts have also been made to achieve a Manufacture tungsten carbide lining, which is pressed into a base body made of steel or another metal or could solder. These attempts, too, only led to limited economic success. Such drill bits are also namely quite expensive and cost about 10 to 20 times as much as an ordinary high-speed steel drill bit. on the other hand have the known drill bits with an inserted complete tungsten carbide lining or with rings that are attached to a base body made of tool steel or a steel alloy soldered on, welded on or mechanically in some other way attached, a sufficient mass of tungsten carbide, so that the coefficient of thermal expansion of the tungsten carbide is crucial Influence on the thermal expansion of the entire drill bit. If now in connection with such drill bits Tools made of tool steel are used, then the different coefficients of thermal expansion of the insert and the tool cause the tool to jam and seize in the insert. This is due to, that the tool steel has a coefficient of thermal expansion that is twice as large as the coefficient of thermal expansion a drill bit with a tungsten carbide bushing or with larger amounts of tungsten oxide in the form of rings or

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Pods. For this reason, the game must initially be chosen large enough to avoid seizing, what has the consequence that at least during the initial phase larger tolerances must be allowed until the tool due to its mechanical stress has heated and expanded accordingly. When the tools are guided very precisely must be so that larger tolerances are not possible at the time of commissioning, there is, on the other hand, the risk of that the tool seizes up as soon as it has warmed up.

The production costs for solid tungsten carbide bushings or drill bits are high, as these parts are, among other things, in their shape must be pressed and sintered and then must be ground with a diamond grinding wheel in order to to carry out the finishing work. Another major disadvantage that arises when using solid tungsten carbide components The result is that it is not possible to use drill bits with different shapes on their outside as solid tungsten carbide is difficult to grind and very brittle.

Based on the prior art, the invention is based on the object of a guide element, in particular a drill bit or a pump seal, which is comparatively simple and cheap, but on the other hand with high accuracy can be produced and has a long life expectancy. In particular, the invention aims to provide improved drill bits to accomplish; However, the basic idea of the invention is also applicable to similar components or guide elements, such as pump seals, bearings, guide bushes, spray nozzles

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and the like, are applicable.

The task set is according to the invention by a Guide element of the type described above solved, which is characterized by the following features:

(a) A base body made of a relatively hard material, in particular steel, is provided in which a recess is provided;

(b) it is a lining with particles having a hardness between about 84 and 93 RHC in a matrix of a Material with a card between approximately 59 and 67 RHC provided, which is connected to at least part of the wall of the recess and that of the support forms the surface of the guide element serving the component to be guided;

(c) the lining is designed in such a way that it and the base body have a coefficient of thermal expansion, which is essentially equal to the coefficient of thermal expansion of the component to be guided.

It is an essential advantage of guide elements according to the invention that between the relatively moved, complementarily formed parts, a structurally predetermined game can be maintained, since the base body consists of steel and the coating or lining, which consists of tungsten carbide particles, which are made in a matrix Chromium and nickel are distributed, only needs to have a thickness between about 0.076 and 0.13 mm. That way you can

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achieve that the coating has essentially the same coefficient of thermal expansion as that made of steel Base body.

Another advantage of the invention is that it provides a surface with abrasion and wear resistance which corresponds to that of solid tungsten carbide parts.

It is also an advantage of the guide elements according to the invention, that they are economical to manufacture and for a fraction of the price of solid tungsten carbide drill bits can be sold.

In an advantageous embodiment of the invention, there is also the possibility of damage to the guide surfaces of the To avoid guide element in that a pure tool steel surface is provided on the inlet side for the tool so that the tool, if fed eccentrically, does not come into undesired contact with the tungsten carbide can get. Beyond the funnel-shaped or conical inlet side of the drill bit, the thin layer with the But then tungsten carbide particles for an extremely wear-resistant guide surface.

Another advantage of the invention is that the guide element, its base body made of an alloy or consists of tool steel, is provided with a thin coating of tungsten carbide particles, which is attached to the base body are metallurgically bound by a matrix of nickel chromium.

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The tungsten carbide particles preferably have a predetermined size and are thus in the nickel-chromium matrix embedded that these have about the same coefficient of thermal expansion like the base body and like the drill or the shaft which runs into the drill bit.

Another advantage of guide elements according to the invention is that despite good or even improved abrasion resistance compared to solid tungsten carbide elements there is less likelihood of parts flaking or breaking during operation or installation.

Another important advantage of guide elements according to of the invention is that their guide surfaces have improved lubricating properties and are not smooth generated solid surface, but a surface with small ones Gaps between the supporting "heads" of the tungsten carbide particles, with the matrix material in the gaps does not reach the height of the heads. This is achieved by changing the amount of matrix material or nickel chromium dosed in such a way that, on the one hand, a perfect bond between the particles and between them and the base body is guaranteed and on the other hand not all spaces between the particles are filled. Stay that way between the tungsten carbide particles there are spaces that form channels for oil or another lubricant, even if a solid shaft or a tool with close tolerance in the guide element or the drill bit runs. In particular, the amount of matrix material is dosed in such a way that the named supporting heads with the

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between located gaps arise after dressing to the correct inner diameter of a bore of the guide element. On the other hand, a guide element according to of the invention is preferably produced in such a way that there is a dense distribution of the Tungsten carbide particles results and there are essentially no voids.

To achieve this goal, it is advantageous if the nickel-chrome matrix is compressed in the course of the manufacturing process in order to expel gas bubbles or light foreign bodies, which during compaction by centrifugal forces or shaking are carried to the surface of the coating and contribute there removed after finishing.

Although the invention is primarily directed to guide elements with a recess in the form of a socket or the like with the advantageous properties described in more detail above, it is also in Within the scope of the invention, the base body with a flat surface area with a flat abrasion-resistant coating according to FIG Invention to provide.

According to a preferred embodiment of the invention, a guide element has a hollow base body made of steel, which can have different shapes and that on the inner wall of its cavity or its bore with a coating is made of a matrix made of a material such as nickel chromium, in which relatively small tungsten carbide particles are present a size of a few; to be evenly distributed, whereby

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the matrix ensures a firm metallurgical bond between the steel base body and the individual particles. The coating can thereby preferably have a thickness between approximately 0.15 and approximately 0.2 mm. This layer thickness is then preferably reduced to about 0.076 mm during finishing.

Preferably, tungsten carbide particles are embedded in the matrix during the production of a guide element according to the invention. However, particles of other materials with a hardness between 84 and 93 RHC can also be used. In a corresponding manner, another matrix material can also be used instead of the preferred nickel-chrome material with a hardness between 59 and 67 RHC can be used.

According to the invention, the base body and the matrix have approximately the same coefficient of thermal expansion, so that when the guide element is heated due to frictional heat in the Operation only weak internal tensions arise. Since the guide element also has almost the same coefficient of thermal expansion like the drill or the shaft which runs in its opening is a from the start a more precise fit possible without the risk of seizure when the temperature rises. This seizure or seizing, in which the materials of the guide element and the guided component are in close contact with one another occurs when the guided component expands significantly faster than when the temperature rises the guide element. Such a seizure is not to be feared with guide elements according to the invention, since these

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when heated, expand in the same way as the guided components; according to the invention can even be particularly Close tolerances can be provided between the guide element and the guided component because of the special surface design the guide surface with the load-bearing tungsten carbide heads and the underlying matrix material even with a very tight fit still good lubrication is guaranteed.

Has for the production of drill bits according to the invention a method has proven particularly useful, which in the case of drill bits or sockets with a diameter of about 3.5 mm or it is more that a thin layer of tungsten carbide particles is placed on the wall of a longitudinal bore in the base body with selected grain size, which are held there by means of a suitable adhesive. Afterward layers of the nickel-chromium matrix material or another suitable alloy are then applied one after the other, whereupon the matrix material is melted, namely in a vacuum, in a hydrogen atmosphere or in a salt bath furnace, wherein the matrix material goes into a liquid state and the interstices between the tungsten carbide particles fills, whereby it connects uniformly metallurgically by diffusion with the inner wall of the longitudinal bore and also causes the tungsten carbide particles to bond. The guide element is also immediately after the melting phase quenched and then annealed. When carrying out this process, it is advantageous if the base body after attaching the tungsten carbide particles drives to a rotary movement around its longitudinal axis and if one such Rotational movement also brings about during the melting phase

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to compact the tungsten carbide particles and to create a filling of all voids in the coating.

The final processing of the so far completed blank then takes place first by rough honing or grinding and then Fine honing or lapping of the inner bore until the desired inner diameter is reached. Then will then the outside of the body is ground to the desired diameter and the correct shape.

The method according to the invention for producing drilling inserts or small diameter bushings differs slightly from that used for making bushings with large diameter. In detail, a blind hole is first created for guide elements with a small inner diameter, an adhesive is applied to the wall. The blind hole is then completely filled with tungsten carbide particles with a Diameter of a few / .mu.m, which was previously filled in a Solution of an adhesive in which nickel chrome powder is carefully distributed and suspended. This ensures a clean flow of the matrix material and perfect integration of the tungsten carbide particles into the matrix, whose material is added in the next process step. In detail, a cup-shaped part of the base body with nickel chrome or a filled with another suitable alloy and treated with an adhesive, whereupon the base body prepared in this way in a vacuum oven, in an oven with regulated Hydrogen atmosphere or is introduced into a salt bath furnace. When the temperature is raised enough that that

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Matrix material has melted, then this fills the cavities and spaces, so that a solid plug is formed Tungsten carbide results that are very firmly connected to each other and to the inner wall of the longitudinal bore. Cheap it is when the prepared base body is driven to rotate while the matrix material is in the liquid state, as this creates centrifugal forces that fill all voids in the coating support. After the heat treatment, the guide element is then ground to the desired outside diameter to create. In addition, a through opening with a precisely predetermined diameter is made in the stopper generated, with an electromechanical machine, with an electric discharge machine or with a laser beam is being worked on. Finally, this opening is honed or lapped to the desired inside diameter of the finished Component as well as the desired surface quality of the continuous To get opening.

If the method according to the invention is used to pump seals or to produce similar guide elements with flat abrasion-resistant surfaces, then in a similar manner proceeded as described above, with the difference that during the melting phase for compaction the material of the coating in the base body vibrations are generated.

Further details and advantages of the invention are provided below explained in more detail with reference to drawings and / or are the subject of the claims for protection. Show it:

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1 shows a block or flow diagram of the method steps of a method according to the invention for the production of guide elements according to the invention with an inner diameter in the Order of magnitude between about 3.5 mm and several Centimeter;

Fig. 2 is a perspective view of a machine for performing essential steps of method according to the invention, which is used for the production of guide elements, which have an inner diameter on the order of between about 3.5 mm and 1.9 cm;

Figure 3 is a cross-section along line 3-3 in Figure 2, looking in the direction of the arrows;

FIG. 4 shows a side view of the machine according to FIG. 2 operational;

5 shows a partial cross section through a modified one Machine for the production of guide elements according to the invention with an inner diameter on the order of between about 1.9 cm and 15 cm or more;

6 shows an enlarged partial cross-section through a guide element according to the invention with a dense coating on the inner surface;

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7 shows a representation similar to FIG. 6 with a guide element according to the invention, in which there are free spaces between the tungsten carbide particles;

Fig. 8

to 12 longitudinal sections through various preferred embodiments of guide elements according to FIG the invention;

13 shows a block or flow diagram of the method steps, similar to the illustration according to FIG. 1, in the manufacture of small guide elements according to the invention with an inner diameter in the order of magnitude between 0.12 mm and 3.5 mm;

14 shows longitudinal sections through a guide element according to the invention or through the blank thereof for different process stages of the process according to FIG. 13;

Fig. 18

and FIG. 19 longitudinal sections through a guide element according to the invention in successive method steps of the method according to FIG. 13;

20 shows a block or flow diagram of the method steps of a further method according to the invention for the production of guide elements according to the invention;

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21 shows a view of a simple device for bringing about a rotary movement of a guide element according to the invention, with some parts broken away;

22 shows a side view of a device for bringing about a rotary movement of guide elements according to the invention and for melting the matrix when carrying out the with the aid of FIG. explained procedure, with some parts broken away and some are shown in section;

Fig. 23

and 24 longitudinal sections through preforming guide elements according to the invention during the manufacture thereof;

Fig. 25

and FIG. 26 shows a side view and a plan view of a furnace as it is used in the implementation of the invention Procedure can be used;

27 shows an enlarged cross section through the furnace according to FIG. 26 along the line 27-27 therein Figure;

FIG. 28 shows an illustration similar to FIG. 26 for a modified furnace; FIG.

29 shows a longitudinal section through a guide element according to the invention in the form of a pump seal;

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30 shows a longitudinal section through part of a modified machine for carrying out the inventive method;

31 shows a longitudinal section through a melting and vibration device for carrying out a modified method for the production of guide elements according to the invention, wherein some parts are shown in section and others broken away;

32 shows an enlarged partial section of the arrangement 31 with a guide element to be machined according to the invention and

33 shows a representation corresponding to FIG. 32, but with the guide element in a different position.

In the case of the one according to the invention explained with reference to FIG The method corresponds to the block or step 30 of the production and cleaning of a blank. Step 30 is preferred carried out in such a way that a workpiece is machined on conventional machine tools. This workpiece must be chemical be clean and free of oil, dust and other contaminants. The blanks are preferably used for cleaning purposes treated in batches in a furnace with a hydrogen atmosphere, with one in preparation for the next process step metallurgical cleaning of the blanks is achieved.

After performing the method described above

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Steps are according to block or step 32 in distilled Boric acid dissolved in water (block or step 32) and nickel chrome powder with microfine grain (block or step 34) mixed together (block or step 35) to make an adhesive. The adhesive obtained in this way has the consistency of heavy fuel oil. The consistency can be controlled by changing the amount of nickel chrome powder added. Besides that the consistency can be reproduced through precise dosing of the liquid component in relation to the weight of the nickel chrome powder. An exact dosage of the mixture components ensures that there is always a predetermined proportion in the adhesive of the nickel chrome powder is suspended. The adhesive produced according to step 35 is applied according to block or step 36 to the applied inner surface or inner wall of the blank. Then (block or step 38) tungsten carbide particles are then produced applied to the surface covered with the wet adhesive. The tungsten carbide particles are supplied while the glue is still wet or damp, so it will be caught in a similar way, itfie if you have a damp finger brings into contact with sugar. The amount of particles that stick to the adhesive depends on the grain size of the Particle dependent. The blank prepared in this way is then (block or step 40) at a temperature between approximately 177 and 404 C until it is brought to a uniform temperature, at which it is then kept for as long becomes as necessary to drive all water or moisture out of the adhesive. In the Production of guide elements according to the invention on an industrial scale, drying (step 40) takes place in a furnace with a continuous conveyor belt in the specified

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Temperature range. The duration of the heat treatment depends on the mass of the blanks; the heating time and temperature however, must be sufficient to ensure that all of the water evaporates and out of the blank or coating is expelled. The prepared blank is then cooled to room temperature and that in step 35 The adhesive obtained is applied to the tungsten carbide layer (block or step 42). It may be required an or to apply several layers of adhesive, as a certain proportion of the adhesive may be absorbed by the tungsten carbide particles.

In the next block or step 44, nickel chrome particles with a grain size between 140 and 250 mesh applied. The number of particles that stick to the adhesive depends on the amount of adhesive and the The grain size of the nickel chromium depends on the main parameters. The smaller the grain size, the stronger the coating, so that if you want a particularly dense coating that is free from voids and where the gaps are are filled between the particles, particles of small grain size are used. On the other hand, one uses when it is desired that there are cavities and free spaces for lubrication or other purposes, a coarser grain.

After step 44 has been carried out, block follows or, in step 46, another heat treatment at temperatures between about 177 and 204 ° C. for a sufficient amount of time long time to bring the blank to the specified temperature

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bring and to evaporate all the water from the glue. Now drying is carried out again in a continuous oven at a temperature between about 177 and 204 ° C, The duration of the heat treatment depends on the mass of the components. The heat treatment should definitely last as long take time for all of the water and moisture to evaporate from the blank. The blank is then on Cooled down to room temperature (block or step 47). The cooled blank is then checked, and excess quantities of tungsten carbide particles and / or glue is removed from the surface, for example with the aid of a knife or a similar tool.

In the next block or step 48, the coating is metallurgically fused to the base body by the prepared blank in a vacuum furnace, in a furnace with a controlled hydrogen atmosphere or in a salt bath furnace is introduced, with best results in a vacuum oven at a temperature between about 1052 and 1107 C. result. The blank is held at this temperature for about 3 to 5 minutes to ensure that the nickel chrome material reaches the liquid state and that the trapped gas escapes, so that the nickel chrome flows into the spaces between the tungsten carbide particles. If the furnace has a quenching chamber, there will be the blanks are quenched directly after the melting phase. If there is no quenching chamber, then there is a special one Quench bath required. After quenching, the blank is tempered to bring it to the desired hardness. After tempering the blank, its bore is honed or

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ground (block or step 50) and then to the desired dimensions and the desired surface finish leped. In particular, the method used to finish the wall of the coated bore will depend on the method used Shape and size of the bore or »the blank.

The socket (or the component or guide element) is then clamped on a mandrel, whereupon the outside up to Achieving the desired outer diameter is ground to ensure that the inner wall of the bore and the Outer surface of the guide element are concentric to one another with an accuracy of about 0.005 mm or less (block or step 51). Using the ground outside surface as a clamping surface, the end and front surfaces of the component are now adjusted to the desired dimensions and with ground to the desired surface quality.

2, 3 and 4 show a machine for carrying out the coating of the blank according to the method according to the invention, for guide elements with an outside diameter of about 2.5 cm or less and with an inside diameter of is no smaller than about 3.5 mm. The machine is denoted by the reference numeral 60 and has a stand 62, to which a motor 64 is fastened by means of a swivel bracket 66, the motor 66 being connected to a drive housing 68 is. The drive housing 68 contains a gear and a worm drive for driving a jig 70. The motor 64 is preferably a direct current gear motor with a foot switch 65. With the help of the foot switch 65 can the operator control the engine speed and thus the

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Speed of the clamping device 70 during the coating process.

The clamping device 70 (Fig. 3) has an outer drive ring or a worm wheel 72, which is through a Screw 74 can be driven so that a receptacle 76 can be driven to rotate. The recording 76 is with the Worm gear 72 connected in a rotationally fixed manner by means of spring-loaded locking ball arrangements 78. The bushing to be coated is in the receptacle 76 is inserted and held there by means of one or more spring clips 80.

4 illustrates the mode of operation of the machine 60 when coating the longitudinal bore of a bushing. The socket will first pushed into the receptacle and held there with the aid of the spring clips 80 (FIG. 2). Then used a brush 82 is used to coat the wall of the inner bore of the socket with the adhesive during the recording 76 turns. After the wall of the hole has been coated with adhesive, as long as the adhesive is still moist, Tungsten carbide particles poured from a container 84 into the funnel of the receptacle 76, which continues to rotate is driven. Those particles that do not adhere to the adhesive fall into a collecting tray The socket or the blank of the guide element according to the invention is then removed from the receptacle 76 and dried. The blank is then reinserted into the receptacle 76 and coated with adhesive in the inner bore, whereupon with the still moist glue from the container 84 nickel chrome or another suitable alloy into the

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Funnel of the receptacle 76 is poured. The unused material falls back into the collecting trough 86. Then the coated blank is dried again. Preferably, the DC motor 64 is in its speed over the Foot switch 65 controlled, which enables the operator to control the speed. However, the motor can also be used with any other suitable devices for speed control.

5 shows a modified machine 90 for producing guide elements according to the invention with an inner diameter between about 1.9 cm and 15 cm. The machine 90 is actually larger than the machine 60 according to FIG. 4, however shown on a smaller scale. The machine 90 has a direct current gear motor 92, whose speed with the help of a foot switch 93, which is comparable to the foot switch 65. Furthermore, a gear 94 is provided, a hub body 96 is seated on its output shaft. The hub body 96 is used to hold a rotary plate 98, which can be driven to a rotary movement via the hub body. In the rotating plate 98, a socket 100 is mounted, which is of the correct dimensions for inserting a receptacle 102. In the receptacle 102 is a socket 106 with Using at least one spring clip 104 supported. The operation of the machine 90 corresponds to that of the machine 60, and again a collecting trough 108 is provided in which the material which does not adhere to the adhesive is collected will.

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Fig. 6 shows an enlarged partial cross-section through a bushing or a guide element according to the invention, which is provided in the area of an inner bore with several layers of tungsten carbide particles 110, which are through a Nickel-chrome matrix with one another and with the base body 112 the socket are connected or welded. For purposes of illustration, the matrix material in FIG. 6 is in the form of Particles drawn; however, the matrix material is liquefied during the melting phase, with the nickel-chromium particles go into the liquid state and fill all voids and spaces between the tungsten carbide particles, which retain their original shape and do not go into solution. After the melting phase, the nickel chrome solidifies and is then firmly bonded to the inner wall of the socket and to the tungsten carbide particles, the fact that the glue at the same time represents a flux, a perfect wetting of the surfaces of the tungsten carbide particles with the liquid nickel chromium ensures that these are firmly integrated into the solidifying matrix. You can see that a guide surface in a finishing operation in which the material of the coating is removed up to line 114 obtained, which is by and large massive and dense. Surface is made of tungsten carbide. With the right choice of grain size for the tungsten carbide particles it can be achieved that the surface after the final machining is up to 90% or consists more of exposed solid tungsten carbide. The proportion of tungsten carbide on the surface depends on the grain size and the scope and type of finishing. Any tungsten carbide particle exposed by finishing has a surface of the correct diameter to

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to be able to contribute optimally to the wear resistance of the entire surface. A guide element according to the invention has a long life expectancy, as the tungsten carbide used can have a Mohs hardness of up to 9.9 if it is cast Material used while the Mohs hardness - on the Mohs hardness scale, diamond has a hardness of 10 - of normal sintered tungsten carbide bushings only achieved values between 9.3 and 9.4. Consequently, with bushings according to the invention or guide elements, a higher life expectancy is expected than with the previously known sockets. This is especially true when the sockets are used, for example, as drill bits when machining material, which has a high abrasive effect.

FIG. 7 shows a representation similar to FIG. 6 with a base body 116 which is essentially in the area of an inner bore is coated with a single layer of tungsten carbide particles in the form of regular blocks and which are embedded in a nickel-chrome matrix with a specified layer thickness. The nickel chrome reaches the liquid state in the presence of the flux in the adhesive, which has the consequence that the tungsten carbide particles during the melting phase be wetted with the nickel chrome. Excess nickel chrome adheres to the wall of the inner bore and collects at the base of the tungsten carbide particles 118 in the form of Fillet welds. In this way, there is a high mechanical strength against the pressures exerted by the guided component and other forces achieved. After the melting phase, there is a heat treatment. When the finishing touches of the coated surface is done along line 120, then

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the result is a finished guide surface with supporting heads of tungsten carbide particles separated by spaces that can accommodate a lubricant so that the The risk of the guided component seizing is considerably reduced, since the spaces have a lubricant supply be able to record. On the other hand, however, the wear resistance of the bush according to FIG. 7 is lower than the wear strength of the bushing according to FIG. 6. Depending on requirements, the guide elements manufactured according to the invention can two surface structures explained with reference to FIGS. 6 and 7 be realized.

As described above, in the final processing of the guide element according to FIG. 7 by grinding, lapping, honing or like a coated inner surface can be obtained in which all exposed tungsten carbide particles one Have machined surface area of the desired diameter. Overall, the surface can after finishing 80% or more consist of tungsten carbide, but the spaces between a free flow of lubricant and / or Coolants behind the surface level corresponding to line 120 enable.

Fig. 8 shows a guide element according to the invention which can be used as a drill bit and which has a base body 122 and a head 124, wherein in the base body 122 a bore is provided which is provided with a coating 126 made of a nickel-chrome matrix with tungsten carbide particles embedded therein, the coating 126 also partially forming the end face of the head 124 covered. When a bit of this type is used

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then there is actually no wear and tear on the steel which forms the head or the upper end of the bushing, if this is held in a drilling device, a jig or the like. On the other hand, it should be noted that the coating on the funnel-shaped opening of the inner bore with abrasion-resistant tungsten carbide for Damage to the cutting edge of a tool made of high-speed steel can result if it is brought eccentrically to the socket will. Consequently, such a coating on an end face is in some cases undesirable, for that reason Drill bits as shown in FIGS. 10, 11 and 19 have been developed.

9 shows a socket with a base body 128 in which a longitudinal bore is provided, on the wall of which a coating 130 made of tungsten carbide in a nickel-chrome matrix is provided, this coating also on the end face of the socket covers a region 132. Bushings or drill bits of the type under consideration which do not have a head, are used where the work surface has to be flat and must not have any protrusions, so that the Bushing must have a flat face without protrusions. In the case of sockets according to FIG. 9, too, it may be desirable to dispense with the coating of an end region 132 in order to avoid tool damage.

10 shows a socket provided with a head with a base body 13 * 4 with a head 136 and a coating 138 Tungsten carbide and nickel chrome. The socket according to FIG. 10 has a similar shape to the socket according to FIG. 8; the

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However, the base body has a longitudinal bore with a shoulder 137 in the area of the head 136, on which the coating 138 ends. A funnel-shaped opening 135 is again provided for inserting a tool, in particular a drill, which consists of the hardened material of the base body 134 or of the head 136, so that the risk of damage to the Cutting edges of a tool when inserting the same into the socket is reduced. Namely, such damage can in the case of coatings with tungsten carbide that are expanded in the radial direction, as provided for the bushings according to FIGS. 8, 9 and 17 are to occur. This is particularly true when the tool is fed to the inlet opening 135 eccentrically, for example because it runs out of round or vibrates before precise guidance is achieved after it has been inserted into the socket. In In this context, it should be noted that a certain deflection or a certain swing does not occur with long tools is unusual.

Fig. 11 shows, similar to FIG. 9, a socket that does not have Has head, the base body 140 being provided with a longitudinal bore, the wall of which is provided with a coating 142 of a Nickel chrome matrix is provided in the tungsten carbide particles are distributed throughout. The inner bore has a shoulder 141 at which the coating 142 ends, so that for the tool provides an inlet port 143 made of the material of the hardened base body and is not provided with a hard coating, so that when a Tool in the socket damage to the same can be avoided. This is especially true in those cases where the Tool runs out of round when inserted or swings before it slides through

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the socket is guided precisely. The design of the sockets 10 and 11 thus took place with regard to the coating under the same point of view.

Fig. 12 shows a longitudinal section through a pump bearing in which a base body 144 with a head are provided, both the outer end face of the head and the wall a longitudinal bore through the head and base body with a coating 148 of nickel chrome with microparticles embedded therein made of tungsten carbide and wherein the coating 148 has a thickness between about 0.076 and 0.127 mm. Such bearings can also be designed in such a way that only the outer end face of the head 146 is included provides a coating.

The block diagram or flow diagram according to FIG. 13 is used for explanation of the inventive method, which is preferably in the production of small bushings or guide elements with an inside diameter in the order of magnitude between approximately 0.12 mm and about 3.56 mm is used.

In this process, the blank is first produced on a conventional machine tool. Marriage then with coating is started, the blank must be cleaned so that it is chemically clean and free of dust, oil, etc. Step 150). The cleaning is preferably carried out in batches, in that a metallurgical cleaning is carried out. A blind hole (block or step 151) is then made in the blank. Tungsten carbide particles of the correct grit are then produced

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precoated with the adhesive produced according to block or step 155 (Block or step 157). The glue used in the step is thin, which means that in it Nickel chromium is only suspended in a low concentration. Preferably the glue is in a container for the Tungsten carbide particles poured out, after which a thorough mixing then takes place. This mixture is then for example placed in a variable speed centrifuge that removes excess glue. The damp Mixture is then placed in a mixer where it is agitated in a stream of hot air. This is done in order to the the individual tungsten carbide particles adhering layer of adhesive and nickel chrome powder to dry and around the particles to isolate.

Before the mixture is completely dry, the particles are sprayed with a dry mist of nickel chrome powder or dusted, which sticks to the slightly damp glue. This will ensure that when you do this later the melting process there is a sufficient amount of nickel chromium to be present between the particles and the base body to create stable fillet welds in the area of the contact points. In the manufacture of pre-coated tungsten carbide particles a larger quantity can be produced at a time than is required at the moment, since the completely dry Material can be stored in closed containers for later use.

The boric acid is now dissolved in distilled water (block or step 152), and nickel chrome powder is mixed with a

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Particle size of a few μm produced (block or step 154), whereupon the prepared substances are mixed together (block or step 155) to obtain an adhesive that has the consistency of heavy oil and its consistency by adding more or less nickel chrome powder can be varied. The consistency of the adhesive can be precisely measured and reproduced by mixing the liquid adhesive obtained in step 152 and the chromium-nickel powder obtained in step 154 in a predetermined weight ratio, the desired amount of nickel-chrome powder being suspended in the adhesive. The adhesive is now fed to the inner wall of the longitudinal bore of the bushing, which is designed as a blind bore (block or step 156).

Next (block or step 158) the dry precoated tungsten carbide particles with a specified grain size are filled into the blind bore, up to such a height that an excess is ensured when the upper end of the blank is cut off in a later machining step. Then the prepared in this way Blanks dried (block or step 160) by placing them in an oven with a conveyor belt, in temperature between about 177 and 204 ° C. The blanks stay in the oven until they reach the specified temperature and until all of the moisture or water has evaporated from the adhesive. Then you leave the blanks cool to room temperature. Thereafter (block or step 161) glue is applied to the protruding tungsten carbide particles applied and introduced into the cavity that is formed by the dam. Then (block or step 162)

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a metered amount of nickel chrome is placed on the upper end of the blank added, which partially fills the space bounded by the dam. In addition, this small amount of Nickel chrome powder added a few drops of glue to the Saturate nickel chrome material. There must be a sufficient amount of nickel chrome to ensure that all spaces between the tungsten carbide particles are filled with nickel chromium. The blank is now dried (Block or step 163) by placing it in an oven with a conveyor belt is used, which is at a temperature between about 177 and 204 C is held until the blank reaches this temperature at which all the moisture from the Glue is evaporated.

The blank is then allowed to cool to room temperature (block or step 164). Thereafter (block or step 165) the coated blank is placed in a vacuum furnace or in a furnace with a controlled hydrogen atmosphere or in a Salt bath furnace, namely until it has reached a temperature between about 1052 and 1107 ° C, at which it is for the duration of about Hold for 3 to 5 minutes. When the furnace is cooled, the parts are placed at a suitable temperature for heat treatment Taken temperature, quenched in a suitable medium and then annealed to give the steel bushings the correct hardness obtain. Step 165 is then concluded. If you work with a vacuum or negative pressure furnace, it is possible to subject the bush or the blank to a heat treatment for quenching and subsequent annealing. The upper and lower ends of the blank are then ground off (block or step 166), with the

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Ground the funnel-shaped inlet and / or the cofferdam removed. The blank is then cut to the desired outside diameter ground to obtain the desired size and surface quality (block or step 168), whereupon then an opening of the desired size in the filling from the Nickel chrome matrix is generated with the embedded tungsten carbide particles. The opening can either be through electrode discharge or spark erosion, by electrochemical etching or electro drilling or - in the case of very small openings with Can be generated using a laser beam. Finally, the guide element is in the course of a final processing (block or Step 172) honed and lapped to the desired inside diameter of the finished workpiece.

FIGS. 14 to 17 serve to illustrate some steps of the method described above in making a bushing of the type shown in Figure 8 having an inside diameter between about 0.33 and about 3.56 mm and an outside diameter between about 6.35 mm and about 12.7 mm. In detail 14 shows a base body 180 with a funnel-shaped Filling opening at the upper end, i.e. with a filling opening, which is surrounded by a dam 182. This base body is made according to step 151 in FIG Machining made. Following the mixing of the adhesive (steps 152,154 and 155 in Fig. 13) then according to step 156 glue on the wall of the blind hole of the base body 180 according to FIG. 14 is applied. Thereafter (step 158), the blind hole, as shown in FIG. 14, is precoated with Particles 184 are filled, whereupon the blank prepared in this way is dried according to step 160. Fig. 15

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shows how after the. Melting step a small amount of nickel chrome penetrated in the liquid state between the tungsten carbide particles to remove all voids and spaces between the particles to form a solid plug of tungsten carbide particles in a matrix of nickel chromium. This stopper has a predetermined diameter, so that after finishing a coating is more predetermined Thickness between about 0.076 and about 0.127 mm. After cooling (step 164) and annealing (step 165), the upper end 185 and the lower end 186 of the base body 180, As shown in FIG. 16, ground off according to step 166. Now the workpiece is made by centerless cylindrical grinding brought to the desired outside diameter (step 168), whereupon the continuous opening is created (step 170), namely by spark erosion, by ECM machining or with the help of a laser beam. The opening 187 will eventually (Step 172) honed and lapped for finishing to the to get the desired inner diameter. 17 shows the finished guide bush with the coating 189 on the wall the opening 187 and an electrode 188, as used in an electric discharge machine to produce the opening could be.

18 shows a blank of a guide element according to the invention before its completion. It is about a very small socket with an inside diameter between about 0.127 and about 3.5 mm and an outside diameter between about 6.35 and about 11.07 mm. The blank has a blind hole 190 with a flat bottom, the wall of which is initially covered with the adhesive that is also used as a flux,

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which is obtained in steps 152, 154 and 155. After the adhesive has been applied, the blind hole is then included Tungsten carbide particles of a given grain size, which are precoated with a dry adhesive layer. this corresponds to step 158 in FIG. 13. The blank is now dried according to step 160 in FIG. At the top of the Blind bore 190 is again provided with a filling funnel with a catch dam 192. There, glue is now fed (according to Step 161), whereupon, according to step 162 in FIG. 13, some nickel-chrome powder is added within the dam 192 to which a few drops of glue are added, the amount of nickel chromium being measured in such a way that it is guaranteed that a sufficient one for the melting step (step 164 according to FIG. 13) There is an amount of metal that can fill all voids and spaces between the tungsten carbide particles, so that a massive plug made of tungsten carbide in a nickel chrome matrix results. Before melting (step 165) drying is initially carried out in accordance with step 163. After the melting step, the workpiece can be taken out of the furnace at the correct temperature, quenched for hardening and then be annealed. Any suitable method can now be used in accordance with step 166 in FIG cut off the upper end of the workpiece along line 194. Furthermore, the opposite end is also dressed in such a way that that the correct overall length of the socket is obtained. During the next step, which corresponds to step 168 in FIG. 13, the peripheral surface of the workpiece is machined to to get the final outer diameter and the desired surface quality. Then the one running in the axial direction Longitudinal opening made as related to

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the step 170 according to FIG. 13 was explained, with an electric discharge machine, an ECM machine or - at very small holes - works with a laser beam. The creation of the opening can improve its centering while the workpiece is being rotated. However, the workpiece can also be held in a stationary version will. Then the opening 196 can now, like this Fig. 19 shows honing and lapping to obtain the desired diameter and surface quality. Deburring, etc., as well as the application of markings and other auxiliary equipment also takes place during this last step for the user.

FIG. 20 shows a block diagram or flow diagram of a further method according to the invention, which corresponds to the method is similar to Figure 1, but with additional steps to increase density and porosity of the inner layer of tungsten carbide in the nickel chrome matrix. In detail, the blocks or steps correspond 230,232,234,236 and 238 directly to the steps 30,32,34,36 and 38 described above. However, in the case of the method under consideration the blank after the application of the tungsten carbide particles on the moist adhesive layer (step 238) to a rotational movement driven around its longitudinal center axis to a centrifugal force of about 50 to 75 times the acceleration of gravity for a period of about 5 to 7 seconds (step 239). Move under the action of this centrifugal force the tungsten carbide particles in the still moist adhesive closer together, i.e. compression is achieved. To this compression of the tungsten carbide particles causes the

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then first go again as described in connection with Fig. 1, wherein steps 240,242,244,246 and 247 correspond to steps 40,42,44,46 and 47, respectively.

After step 247 has been carried out, the method explained with reference to FIG. 20 then deviates again from that described at the beginning Procedure. The blank is then cooled to room temperature and checked (step 247) namely, the welding of the coating to the blank, while the blank again rotates about its central longitudinal axis is driven, with an outward centrifugal force in the coating of about 180 to 200 times the acceleration due to gravity is generated (step 248). In this way, the molten nickel chrome gets into the spaces pressed between the tungsten carbide particles, whereby air and gas bubbles as well as solid boric acid particles and other light ones Foreign matter is driven to the surface of the coating. In the method described at the beginning, the filling takes place the gaps during the melting phase depending on the capillary action of the openings between the tungsten carbide particles. In the case of the method described here, a surface that is perpendicular to the surface to be coated is inevitably used Force generated to force the filling of all cavities and spaces. The temperature will be the same as before brought to values between about 1052 and 1107 ° C, and the component is kept at this temperature while it is in a suitable atmosphere is driven to a rotary motion. As centrifugal force increases the speed at which the gaps are filled, the workpiece only needs about

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for a period of 30 to 40 seconds at the elevated temperature are held and at the same time driven to a rotary movement.

The component is then quenched and tempered (step 249) and then subjected to finishing by first brings the inside diameter of the bore to the desired final values by honing or grinding (step 250) and by subsequently machining the circumference to achieve the desired outer diameter (step 251) and Finally, the end faces are finished (step 252).

Fig. 21 shows a simple device for driving a component to a rotary movement, namely for compressing the Tungsten carbide particles by a centrifugal force (step 239). The device 260 shown in Fig. 21 has a frame or a housing 262 on which an electric motor 264 is mounted, which has a vertical output shaft 266. On the Output shaft 266 is seated non-rotatably with a clamping device 268 for receiving a blank 270 to be machined. A speed controller 272 is calibrated in such a way that the inner diameter of the respective blank to be machined can be set on it, whereupon the appropriate speed of the motor 264 for that inner diameter is generated by the desired 50 to 75 times To obtain acceleration due to gravity in the coating of the respectively clamped blank 270. An automatic start-stop control 274 interacts with the motor 264 and a brake 276 in order to set the desired speed in each case for the specified Generate time interval.

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22 shows a device with the aid of which the melting process can be carried out in the coating of a blank 270 under the action of a centrifugal force (Step 248). The device 280 shown in FIG. 22 has a frame 282 on which an electric motor 284 is mounted, which is coupled to a drive shaft 286 via a coupling 288. The drive shaft 286 is in a bearing block 290 rotatably mounted and carries a fitting 292, from which a lower mandrel 294 protrudes upwards. An upper mandrel 296 is from a vertical rod 298 and is rotatable relative to this by means of a bearing arrangement 300. The rod 298 is Part of a hydraulic cylinder unit 302, which is mounted on the frame 282 and has a cylinder 304 and a piston 306 which is reciprocable in the cylinder 304 and to which the rod 298 is attached. A leverage for example air, which is supplied via a connection 308, causes the piston 306 with the rod 298 is raised, whereby the upper mandrel 296 is raised relative to the lower mandrel 294. When the upper mandrel 296 is raised is, then a blank 270 can be placed on the lower mandrel 294. The upper mandrel 294 lowered by supplying a pressure medium to a connection 310 so that the blank 270 is set between the mandrels 294 and 296.

An induction coil 312 is carried by arms 314, which with With the aid of a drive unit, for example a cylinder unit 316, moved into an upper and a lower position can be. When the arms are in their upper position, as shown in FIG. 22, the induction coil surrounds 312

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the blank 270 and can heat it to the desired temperature. When the arms 314 are in their lower position, then the induction coil 312 is lowered so far that the Space between the mandrels 294 and 296 for inserting and removing blanks 270 is easily accessible.

The cylinder unit 302 is operated with the aid of a control key in order to enable blanks 270 to be inserted and removed. A start button 322 is used to initiate a controlled cycle in the course of which the induction coil is brought into its heating position and then energized and in the course of which the motor 284 is caused to drive the blank 270 to rotate for a predetermined time interval. A speed or speed controller 324 is again calibrated with regard to the inner diameter of the blanks 270 to be machined, so that the suitable speed can be selected in order to make a centrifugal force effective in the coating of the blank, which corresponds to 180 to 200 times the acceleration due to gravity . While the blank is driven to rotate and heated, a suitable gas mixture, for example a mixture with 95% argon and 5% hydrogen, is fed to a chamber 326 via a solenoid valve 328. The gas mixture flows from the chamber 326 via a channel 400 in the rod 298 and a channel 402 through the upper mandrel 296 into the blank 270 in the fitting 292 is in communication. _The outlet channels 406 direct the gas mixture upwards against the outside of the blank. In this way

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a suitable inert atmosphere is created while the ingot is rotating and while melting is taking place inside of the blank takes place. Another switch 408 is provided to bring about an emergency stop of the machine.

FIG. 23 shows a blank 270 which is designed in such a way that it is suitable for carrying out the method according to FIG. 20 is. The blank 270 has a base body 410, a head 412 and a coating 413 in the area of an inner bore, wherein the coating consists of a nickel-chrome matrix in which tungsten carbide particles are distributed, which be connected to the inner surface of the bore as well as to part of the inner surface of the head 412 by means of the matrix should. The blank 270 is used to produce a drilling insert and has a length which is greater than that of the finished drill bit, as above a line 416 additional head part 414 and below a line 420 an additional main body part 418 are provided, which later sanded or otherwise removed. The parts 414 and 418 are in the radial direction inward over the Coating 413 in front and form dams 422 and 424 to hold back the material of the coating 413 during the melting process, in which the blank 27o is rotated about its longitudinal center axis L. Conical surfaces 426 at both ends form each a seat for the upper and lower mandrels 294 and 296 of the device 280, respectively.

During the completion of the blank 270 for the production of a drill bit, the parts 414 and 418 are by grinding to removed to lines 416 and 420, with corner 428 removed

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is rounded (step 252) so that ultimately a drill bit which is similar to that of FIG. 8 is obtained.

24 shows a modified embodiment of a blank 430, from which a drilling insert without a head is finally produced becomes, as Fig. 9 shows. The blank 430 has a base body 432 with an inner bore that is coated with a coating 434 is provided. Body parts 434 and 438 protrude over lines 440 and 442, respectively, and form dams 444 and 446, respectively to hold back the molten coating while the blank closes about its longitudinal center axis LL during the melting process a rotary motion is driven. Parts 436 and 438 will later be removed to lines 440 and 442, with the corner 448 is rounded to provide a headless drill bit to obtain.

FIG. 25 shows a machine 450 or a furnace for performing the melting step (step 248) with a rotary movement driven large blanks with an inner diameter of 4.4 cm or more or smaller batches Blanks with a blind hole, such as those used for small bearing bushings and, for example, in FIG. 14 and 18 are shown. The machine 450 has a frame 452 which has an insulated furnace chamber 454 with a base plate 456 carries. The base plate 456 is relative to the frame 452 between an upper position in which it the Oven chamber 454 closes and which is shown in Fig. 25 in solid lines and a lower position shown in dashed lines Lines is drawn and in which the furnace chamber is open, movable back and forth. The movement between the

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upper and lower position is achieved with the aid of a rack and pinion gear arrangement 458 brought about and enables a loading and unloading of the furnace chamber 454 with the to be treated Blanks.

A clamping device 460 is provided above the base plate 456. In Fig. 25 is in the jig 460 a blank 462 for a large drilling insert, which is driven to perform a rotary movement in order to carry out step 248 and should be heated up. The clamping device 460 is seated to bring about the rotational movement of the blanks 462 on a vertical shaft 464, which is rotatably mounted in a bearing arrangement 466, which with the help of a sub-frame is attached to the base plate 456. A motor 470 also attached to the subframe 468 is by means of a coupling 472 coupled to one end of the shaft 464, while the other end of the shaft 464 by a pin 474 with a square Cross section is formed which engages in a complementary mount 476 of the clamping device 460. If the If the motor 470 is running, it consequently rotates the shaft 464 and thus also the clamping device 460. The speed is thereby reduced regulated by an electronic speed controller (not shown).

To protect the shaft 464 against overheating, it is with Chilled water. Inlet 480 leads to a central tube 482 in shaft 464 via manifold 484 and 484 an opening 486 so that cooling water can be supplied to the pipe 482. The cooling water flows upwards and under pressure

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is then diverted down into channels 488 which act as return lines serve and through which the water reaches an outlet 494 via openings and a distributor 492. in the A suitable inert atmosphere is created inside the furnace chamber 454 by adding an inert gas mixture to the chamber 454 is supplied via an inlet 496, while the discharge of the gas mixture takes place via an outlet 498.

As FIGS. 26 and 27 show, the clamping device 460 has an outer jacket 500 which is cylindrical Insert 502 made of ceramic, graphite or other highly refractory material receives which the holder of the blank 462 at whose rotation about its longitudinal center axis C is used. When the machine 450 is used for batch processing of small blanks to be used, which have a blind hole, then the cylindrical insert 502 is removed and replaced by two or replaces several wedge-shaped inserts 504, which are also made of ceramic, graphite or another highly refractory material exist as shown in FIG. 28. The wedge-shaped inserts 504 lie between adjacent ribs 506 of the Clamping device 460 and each have a plurality of horizontally aligned openings 508 for receiving small blanks 510, which are then rotated together with the jig while they are heated, creating centrifugal forces are generated, which the molten coating or the molten matrix material with those located therein Particles inside the blanks 51O press against the bottom of the blind hole, whereby the tungsten carbide particles in the Nickel-chrome matrix are compressed, whereby all cavities are filled, while trapped gas bubbles and foreign

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Low weight materials are pushed away radially inwards.

29 shows a guide element according to the invention in the form of a pump seal 520, which has an essentially cylindrical base body 522 with a flange 524 at one end, the base body and the flange being made of steel. A circular recess 530 or 532 is provided on each of the two end faces 526 and 528 of the base body, which is filled with a coating 534 or 536 of tungsten carbide particles that are distributed in a nickel-chrome matrix. The coatings form abrasion-resistant coatings and are similar to the coatings which have been explained above for socket-shaped components of various shapes. The coatings, which are formed by ^1, the coatings 534 and 536, allow two to adhere together supporting, relatively movable parts in a precise mutual position.

In principle, the method for producing a pump seal 520 is the same as the method described above Manufacture of bushings and the like insofar as the training of the blank 538 for the pump seal 520 is concerned and what the application of the adhesive and the tungsten carbide particles in the recesses of the blank 538 (Fig. 30). For compacting cavities in the coatings and 536, however, centrifugal forces are not used for the coating during the melting phase. Instead it will carried out the melting phase for each coating, while at the same time vibrating the blank 43 8 in the direction of its

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Longitudinal central axis P can be brought about.

Thus, in a method of manufacturing the pump seal 520, the initial steps are steps 32 to 47 of the method according to FIG. 1 very similar. To fill the recesses 530 and 532 - the recesses can only be used one after the other and not can be filled at the same time - a device similar to that shown in Fig. 5 can also be used. In detail, the machine 90 according to FIG. 5 is modified in that the socket 100 and the receptacle 102 are passed through replaces a version 540 similar to the version 100, but whose internal dimensions are selected so that a blank 538 for a pump terminal 520 can be added, as FIG. 30 shows. The machine 90 is also oriented so that the longitudinal center axis P of the blank 538, as shown in FIG. 30, assumes a vertical position. The version 540 has a larger bore 542, the inner diameter of which corresponds to the outer * diameter of the flange 524, and a smaller one Bore 544, the inside diameter of which corresponds to the outside diameter of the other end of the base body 522. The blank can consequently be inserted into the mount 540 in such a way that either the recess 530 or the recess 532 follows at the top and can be filled with glue and particles in this position.

If then the recess 530 in the course of steps 32 to 47 is filled with the coating material, the blank 538 is placed in a vibration device, wherein the material is melted in the recess 530 while at the same time

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Vibrations of the blank 538 preferably in a vertical direction parallel to the longitudinal center axis P of the blank 538 and are brought about essentially perpendicular to the plane of the recess 530. As shown in FIG. 31, the blank 53 becomes for this purpose inserted into a device 550 which has a stationary frame 552 which carries a hood 554 which seated in a sealing sand bed 556, so that a closed chamber 558 results. The hood 554 can be of the Frame 552 can be lifted off to gain access to the interior of the chamber 558. As with the arrangements described above is an inert gas mixture, for example a mixture of argon and hydrogen, via a supply line 560, to create a suitable atmosphere in the closed chamber 558. The gas mixture is via a pipe 561 discharged.

As can best be seen in FIG. 32 and also in FIG the blank 538 is inserted into a support ring 562 which is fastened to a platform 564 which is supported by a subframe 566 which has posts 568 which are movably guided in seals 570 of the frame 552. The subframe 566 is attached to the stationary frame 522 by means of a suspension system supported, which has oppositely acting helical springs 574 that move up and down of the subframe 566 with respect to the stationary frame 522. With the subframe 566 is a with Air-powered vibrator 576 connected to the sub-frame 566 in a vertical direction with an amplitude of approximately 0.013 to 0.025 mm and can oscillate at a frequency of about 16,000 to 20,000 strokes per minute.

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When the sub-frame 566 vibrates, the blank 538 also vibrates. At the same time, an induction coil 578, the is located immediately above the coating in the recess 530 of the blank 538, switched on to the blank 538 to locally heat and to bring the coating material in the recess 530 to melt. The induction coil 578, the energy is supplied via a connection coupling 580, while cooling water for the induction coil 578 is supplied via a fitting 582. The generation of the vibrations and the heating take place simultaneously for the duration from about 30 to 90 seconds for complete melting of the matrix material and complete filling of the cavities to achieve, with gases and light foreign matter being expelled to the surface of the coating.

The entire process is then repeated to produce a coating in recess 532. This means that the Blank 538 is again inserted into the socket 540 of a modified machine 90, but this time in such a way that the recess 532 is above. When the recess 532 is then filled, the blank 538 is inserted into the socket 562 of the machine 550, the socket assumes the position shown in FIG. 33, so that the recess 532 is at the top. Afterward vibrations are generated again in the blank 538, while at the same time the coating material is in the recess 532 is melted. Since the induction coil 578 only causes local heating, the melting occurs of the coating material in the recess 532 does not lead to remelting of the material in the recess 530.

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After the coatings in the two recesses 530,532 have been completed, the blank 538 is removed from the machine removed, quenched, tempered, and finished to produce the finished pump seal 520. By generating vibrations during the melting process, it is possible to obtain improved, wear-resistant coatings with a flat surface in those components where such flat surfaces are desired.

909830/0 5 34

Claims (20)

DR.-ING, DIPL.-ING. M. SC. DlPL. PH "S C1 *. DIPL.-PHYS, HÖGER - STELLRECHT - GPiESSBACH - HAECKER PATENTANWÄLTE IN STUTTGART A 42 754 b Applicant: Edward J. Voitas k - 163 59 De Gray Terrace February 27, 1978 Mawah, New Jersey 07401 USA Patent claims: 1. Guide element, in particular a drill bit or the like, for the precise mutual alignment of relatively movable, mutually supporting Surfaces, one of which is a surface of the guide element and the other a surface of a component supported thereon, characterized by the following features: (a) A base body (116) made of a relatively hard material, in particular steel, is provided, in which a recess is provided; (b) it is a liner with particles (118) having a hardness between about 84 and 93 RHC in one Matrix (119) made of a material with a hardness zv / ischen about 59 and 67 RHC provided with at least part of the wall of the recess is connected and that of the support of the Forms the leading component serving surface of the guide element; (c) the lining (118,119) is designed so that it and the base body (116) have a coefficient of thermal expansion have, which is essentially equal to the coefficient of thermal expansion of the component to be guided is. 909830/0534 February 27, 1978 - 2 - 2. Guide element according to claim 1, characterized in that the particles (118) consist of tungsten carbide. 3. Guide element according to claim 1 or 2, characterized in that that the matrix (119) consists of a nickel-chromium alloy. 4. Guide element according to one of claims 1 to 3, characterized characterized in that the surface serving to support the component to be guided essentially is flat. 5. Method for producing a guide element, in particular a drill bit or the like, according to one of claims 1 to 4, characterized by the following process steps: (a) A blank is produced with the desired external dimensions and the desired internal dimensions the recess and with a longitudinal central axis; (b) the blank is cleaned of impurities; (c) An adhesive is made from boric acid and nickel chromium powder dissolved in distilled water here; (d) applying the wet adhesive to the interior surfaces of the blank; 909830/0534 February 27, 1978 - 3 - (e) Tungsten carbide particles are added to the wet adhesive in such a way that they are removed from the adhesive surface be captured; (f) The blank prepared in this way is dried at a temperature between about 177 and 204 ° C long enough to drive moisture out of the adhesive; (g) additional wet adhesive is added to the coated inner surfaces of the blank; (h) Nickel chrome powder is added to the wet adhesive on the coated inner surfaces in such a way that it is captured by the adhesive surface; (i) The blank thus treated is dried at a temperature between about 177 and 204 ° C for a long enough time to drive off the moisture; (j) the temperature of the blank is increased to values between about 1052 and 1107 ° C; (k) the blank thus obtained is annealed for a period of time and at a temperature which leads to a lead suitable heat treatment of the base body of the blank and (1) The blank is finished to obtain the desired dimensions and surface qualities by. 909830/0534 February 27, 1978 - 4 - 6. The method according to claim 5, characterized in that the blank when performing step (j) for a period of between 3 and 5 minutes on a Maintains temperature between about 1052 and 1107 ° C. 7. The method according to claim 5, characterized in that the blank is driven to rotate about its longitudinal center axis between steps (e) and (f), a centrifugal force that acts on the tungsten carbide particles and drives them into the wet adhesive of about 50 to 75 times the acceleration due to gravity. 8. The method according to claim 5 to 7, characterized in that the blank while he is performing of step (j) is kept at a temperature between 1052 and 1107 ° C for a period of 30 up to 40 seconds to drive a rotary motion to one on the tungsten carbide particles and the nickel-chromium alloy to generate attacking centrifugal force of about 180 to 200 times the acceleration of gravity. 9. A method for producing a guide element, in particular a drill bit or the like according to one of Claims 1 to 4, characterized by the following features: (a) A blank is produced with the desired external dimensions; 909830/0534 February 27, 1978 - 5 - (b) the blank is cleaned of impurities; (c) a longitudinal hole in the form of a blind hole is drilled into the blank; (d) An adhesive is made from boric acid and nickel chromium powder dissolved in distilled water come from? (e) applying the adhesive to the surface of the longitudinal bore; (f) precoating the tungsten carbide particles with the adhesive; (g) the longitudinal opening is filled with the precoated tungsten carbide particles; (h) the blank is dried at a temperature between about 177 and 2O4 ° C for a sufficiently long time, to drive off moisture; (i) glue is introduced into the longitudinal bore; (j) a measured amount of nickel chromium particles is added to the upper end of the longitudinal bore; (k) the blank is dried at a temperature between about 177 and 204 ° C. for a sufficiently long time to drive off moisture; - 6 - 909830/0534 February 27, 1978 - 6 - (1) the temperature of the blank is increased to values between about 1052 and 1107 ° C; (m) the blank is annealed for a time and at a temperature which is suitable for a suitable heat treatment of the base body of the blank are; (n) one removes the upper and the lower end of the blank, in this way the ends of the filled Expose longitudinal bore; (o) a through opening is created in the filling of the longitudinal bore; (p) the blank is finished to the dimensions and dimensions desired Maintain surface quality. 10. The method according to claim 9, characterized in that the blank when performing step (1), while it is kept at a temperature between about 1052 and 1107 ⁰ C, is driven to rotate for a period of between 30 and 40 seconds to generate a centrifugal force of about 180 to 200 times the acceleration due to gravity acting on the tungsten carbide particles and the nickel-chromium alloy in the longitudinal bore. ■ 9 09830/0534 k - 163 February 27, 1978 - 7 - 11. The method according to claim 9, characterized in that the blank is kept at a temperature between about 1052 and 1107 ⁰ C for a time between 3 and 5 minutes. 12. The method according to claim 9, characterized in that the opening in the filling is made by electric drilling. 13. The method according to claim 9, characterized in that the opening in the filling by electrical discharge generated. 14. The method according to claim 9, characterized in that the opening in the filling with the aid of a laser beam generated. 15. A method for producing an abrasion-resistant guide element, in particular a drill bit or the like, characterized by the following steps: (a) A blank is produced with a surface on which an abrasion-resistant coating is applied shall be; (b) at least the surface of the blank to be coated is cleaned of impurities; (c) make a wet adhesive with nickel chrome powder; 909830/0534 February 27, 1978 - 8 - (d) the wet adhesive is applied to the surface of the blank to be coated; (e) Tungsten carbide particles are added to the adhesive; (f) the adhesive with the added tungsten carbide particles is dried to form a base coat to form on the surface to be coated; (g) applying additional wet adhesive to the basecoat; (h) Nickel chrome powder is added to the further wet adhesive to; (i) the further wet adhesive is dried with the nickel chrome powder in order to be coated on the Surface to produce a complete coating; (j) the temperature of the blank is raised at the coated surface to values between about 1052 and 1107 ° C and the blank is stopped this temperature to melt the nickel chrome material and so the tungsten carbide particles embedded in a matrix that adheres to the surface to be coated. 909830/0534 February 27, 1978 - 9 - 16. The method according to claim 15, characterized in that that one can remove the tungsten carbide particles after adding them to the adhesive and before drying the latter condensed » 17. The method according to claim 15, characterized in that that one on the complete coating while maintaining the temperature between about 1052 and 1107 ° C, exerts a force to fill voids in the coating and drive off unwanted foreign matter. 18. The method according to claim 17, characterized in that the force, starting from the complete Coating in the direction of the surface to be coated and essentially perpendicular to it works = 19. The method according to claim 17, characterized in that the force is increased by driving the blank generated by a rotary motion » 20. The method according to claim 17, characterized in that the force is generated by causing vibrations of the blank. - 10 - 909830/0534