EP0002177A1 - Rail grinding machine for grinding irregularities off the running surface of rails - Google Patents

Abstract

1. Travelling track grinder for the grinding of irregularities of the track surface, the said track grinder comprising at least one grinding tool (8, 54) which is vertically and laterally adjustable by an adjusting drive (12, 13, 51, 52) relative to a machine frame (3) which is guided on the rail by travelling mechanisms (4), a measuring device (25) for limiting the grinding depth with the aid of the frame serving as a reference, a control device (26, 62) which is associated with the adjusting drive (12, 13, 51, 52) and a second measuring device (24) for determining and in particular indicating, even during the grinding operation, the distance between a reference surface and a reference base (17) which determines the intended direction of the track surface and which is connected to a monitoring device, characterized in that the second measuring device (24) is associated with the grinding tool (8, 54) and is connected to the control device (26, 62) for controlling the adjusting drive (12, 13, 51, 52) and to the control unit (32, 66), and that the reference surface for determining the distance is the grinding surface (23, 60, 72) of the grinding tool (8, 54).

Description

The invention relates to a mobile rail grinding machine for grinding irregularities in the rail running surface, with at least one grinding tool which can be adjusted in height and / or side relative to a machine frame guided over running gear on the track, and with a measuring device for limiting the grinding depth using of the frame used as a reference and with a control device assigned to the setting drive.

The high driving speeds in modern train traffic require, especially for reasons of safety, economy and driving comfort, a good condition of the rail surface and thus also its maintenance. Not least due to these high driving speeds in connection with the extremely high axle loads, the rails are often stressed to the yield point and are therefore subject to relatively high wear. You lose her in the process Profile and there is damage on the driving surfaces (driving mirror) and driving edges, such as corrugations, waves or burrs or the like. The characteristic of the unevenness in the rail running surface or rail surface is very different and ranges from very short waves - in which the wave crests are arranged at a very short distance from each other - the so-called corrugations, up to long waves caused by skid points or blocked wheels and extending over a longer area along the track. All these errors and unevenness in the rail surface cause vibrations and shocks to occur when driving on such a track, which are transmitted to the trolleys or vehicles and thereby adversely affect the track position or cause a high level of noise pollution. To eliminate this damage to the rails, they are therefore ground at certain intervals using grinding devices or rail grinding trains. This is done e.g. B. using one or more rotating grinding wheels arranged one behind the other or relative to the advancing rail grinding machine in the longitudinal direction alternately reciprocating grinding stones. The grinding tools with the necessary control or sensing elements are arranged either on small grinding machines that can be lifted off the track, self-propelled machines or own grinding trains. In many cases, short nelle, the wave crests of which are arranged one behind the other at a smaller distance in the longitudinal direction of the track than the length of a grinding tool or grinding tool area used on the rail running surface, are therefore eliminated effective and satisfactory, since the grinding tool always rests on two adjacent shaft crests and the lower areas or the depressions of the corrugations are not machined. However, if the wave crests of a corrugation in the longitudinal direction of the track have an edge that extends beyond the length of the grinding surface that is being used on the rail running surface, there are always difficulties when processing them, since it is usually impossible to prevent the recess between the ridges are ground and the Sehienen driving surface is often deteriorated.

A rail grinding machine is already known - m-OS 26 12 174 - which has a machine frame guided over bogies on the track with a tool frame mounted on this height-adjustable belt. Two grinding tools are arranged on the tool frame for common height adjustment with it. The height adjustment of the tool frame or the feed _{J of} the grinding tools is carried out via a control device which acts accordingly on the grinding tool group setting drive. The procedure is such that the current consumption of the drive motors of the grinding tools designed as rotatable grinding wheels is measured with a measuring device. This control or measuring device blocks the grinding depth of the grinding tools when the motor current limit values which can be set or fallen below are compared with the frame serving as a reference. The grinding surfaces of the grinding tools are, regardless of their height setting, relative to the machine frame in mutually parallel planes. This design of a grinding machine has proven itself, because the grinding tools remain in the recesses of the rail surface due to the grinding surfaces remaining during the adjustment processes in mutually parallel planes - the shaft crests of which are at a distance from one another in the longitudinal direction of the track that is greater than the length of the ones used Grinding tools - is avoided. In some applications, especially if the distance between the shaft ridges of a depression is greater than the distance between the grinding tools arranged on the tool frame, grinding can also be carried out with this device. of the rail surface areas that are too low cannot always be sufficiently avoided.

Furthermore, a rail grinding machine is known - DE-PS 15 34 o37 - which is provided with a group of grinding tools which are mounted on this machine such that they can move in height relative to the machine and relative to one another. A control device for the respective setting drives of each grinding tool is designed such that the grinding tools are each in a horizontal plane, and which acts upon the setting drive with a downward movement of a grinding tool into a position below the horizontal position of the other grinding tools with increasing force in the opposite direction . In addition to the very high technical outlay for this control device and the adjustment drive, the adjustment is very slow and does not allow exact height guidance of the grinding tools relative to Rail surface. As a result, grinding of the lower-lying areas of a corrugation, in particular with corrugation crests spaced apart from one another in the longitudinal direction of the track, cannot be avoided.

A device of the prior art - DE-OS 26 o6 149 - which has a roller guided along the rail also counts for measuring irregularities in the rail surface. The accelerations or changes in acceleration exerted on this role are used after treatment in an electronic computing unit as a measure of the irregularity of the rail surface. With this device, however, is at best a general statement about the quality of the rail surface - z. B. an improvement or deterioration compared to a previous test run - noticeable, an exactly accurate geometric measurement of the rail surface is not possible. Furthermore, it is not provided in this device to use the measured values to control the infeed movement of grinding tools, since in particular no exact measured values are determined to control them.

In another known grinder
- DE-OS 27 o1 216 - a measuring device for determining the average amplitudes of the changes in the rail surface is arranged directly on the vehicles receiving the grinding device. The values determined in this way are used to preset grinding pressures, cutting speeds or the right-of-way speed corresponding to these amplitude values

Vehicle used. The characteristic values for the grinding tools can thus be monitored in such a way that damage to the tool and rails is avoided if larger errors occur. However, the restoration of a longitudinal profile of the rail surface that is adapted to the desired rail head profile is not possible only on the basis of the regulation of the cutting force or the grinding pressure of the grinding tools, since in this case too, machining of rail surface areas that are too deep cannot be avoided with longer shafts. In addition, there are inaccuracies to the extent that in this grinding device, as in the rail grinding machines already described above, the setting of the grinding tools is made more difficult by the different wear thereof.

The invention has for its object to provide a rail grinding machine of the type mentioned, which enables the desired longitudinal surface of the rail surface to be produced with high accuracy, in particular by precisely maintaining or adjusting the distance of the tools on the rail surface to be machined.

This object of the invention is achieved with the rail grinding machine described at the outset in that the grinding tool has a further measuring device for determining and in particular displaying the distance - in particular also during the grinding process - between its grinding surface and a reference base which determines the desired course of the rail surface is assigned, which is operatively connected to a control device and possibly the control device for the adjustment drive or to a further control unit assigned to the adjustment drive.

The solution according to the invention is characterized in particular by the fact that, for the first time, simple monitoring of the condition, in particular wear, and accurate measurement of the grinding tool surfaces are possible not only in relation to the surfaces of the longitudinal rail areas to be ground, but also in relation to a reference base. This accurate measurement of the position of the grinding tool surfaces - with their continual changes due to wear during the grinding process - now creates the basis for making this grinding surface accurate, regardless of the wear of the grinding tool and the constantly changing position of its grinding surface relative to a reference base to track or deliver the surface of the rail to be machined. However, at the same time this ensures that, even when the grinding tool surface advances following the surface trend of the rail surface, it does not fall below a certain predeterminable target level, and thus machining of areas that are too deep between two shaft crests is avoided. Overall, this achieves a high level of accuracy in the production of the longitudinal surface of the rail surface. The accurate monitoring of the grinding tool surface brings a significant simplification and relief for the operator, especially during work, since with the simplified control option with regard to the delivery of the Grinding tool surfaces on the surfaces to be machined can also get an overview of the degree of wear or changes to the grinding surface at any time. As a result, the time at which the grinding tools are to be replaced can easily be determined without leaving the rail grinding machine and, in particular, also during work. Seen overall, the solution according to the invention therefore advantageously also enables simple recognition of the changes on the grinding surfaces of the grinding tools and the precise production of the rail surface even during work.

According to a further embodiment of the invention, it is provided that the further measuring device comprises a transducer which interacts with the grinding surface of the grinding tool, in particular a grinding stone, and is preferably arranged on the reference basis. In addition to the rapid feed movement and positioning of the grinding tool surfaces, the use of a sensor also enables a continuous determination of the state of wear of the grinding tools, in particular during the grinding process. The transmitter can therefore also be used to determine whether a grinding tool replacement is required.

It is also advantageous if the transducer by at least one abrasion sensor, for. B. a lamellar foil or carbon layer or the like., Formed, since the height of the transmitter and in particular its resistance is changed simultaneously with the wear of the grindstones. This is the height of the grinding surface relative to the tool frame or the reference base can be determined without additional touch devices and circuit arrangements.

On the other hand, it is also possible within the scope of the invention that the transducer by an electrical transducer, for. B. a rotary potentiometer, with a pivotable sensor arm and one lying on the grinding surface, for. B. diamond-coated or hardened sensor roller is formed. Since the grinding wheels usually do not rest with their entire grinding surface on the rail surface, the height of the grinding surface relative to the tool carrier or to the reference base and thus its position in relation to the rail can be continuously monitored in parallel and continuously by means of the transducer.

It is also expedient in the context of the invention if the further measuring device comprises the measuring transducer arranged on the grinding tool or a supporting part, in particular a tool frame, which is connected to the grinding tool and a further measuring transducer for determining the distance between this grinding tool or supporting part and the reference base. In this way, the infeed movement can be carried out extremely sensitively by acting on the setting drives assigned to the tool frame and can be limited exactly when the desired measured value occurs. Regardless of this, the adjustment drives can also be used to achieve a desired grinding pressure.

According to the invention, it is also advantageously possible for at least one of the sensors of the further measuring device, if appropriate via an input or storage device and a downstream difference-forming or summing element of the control unit, with a pressure line, which is provided by a hydraulic cylinder-piston. Arrangement formed adjustment drive - located control valve arrangement of the control device or the control unit is connected, wherein the control valve arrangement can be acted upon to limit the infeed movement at a distance between the grinding tool surface and the reference base corresponding to the desired distance via the control device or unit for interrupting the pressure supply line. By using control valve arrangements that directly influence the setting drive, the infeed movement can be quickly and safely limited at any time without changing a preselected grinding pressure. In addition, the optional arrangement of input or storage devices enables exact height guidance of the grinding tool surfaces even with only periodic measured value determinations, and it is therefore possible, for example, for the grinding process to be ended automatically when a preset limit on the wear of the grinding tools has been reached .

A further development of the invention provides that at least one of the sensors via a measuring device for determining the grinding pressure when a grinding pressure occurs - in particular when Exceeding a motor current supplied to the motors of the rotatable grinding tools - the switching element acted upon can be connected to the control device or the control unit for determining and / or displaying the distance between the grinding surfaces and the reference base. A measuring device guided on the rail can thus be used in cooperation with the reference base or the machine or tool frame to determine the degree of wear of the grinding tools and to determine the distance of the grinding surface of the tool from the reference base, since the measurement values are only registered if when there is full contact between the grinding surfaces and the rail surface, ie the rail surface thus forms the measuring basis for the position of the grinding surface. Furthermore, the registration or storage of the height of the grinding surface can take place immediately when a grinding pressure is built up - ie at the beginning of the occurrence of a grinding effect between the grinding surface and the rail surface.

An embodiment has also proven to be advantageous in which the measuring device is formed by strain gauges arranged on parts of the tool frame, the machine frame or the supporting parts of the grinding tools, in particular the grinding stones or the drive shafts of the rotatable grinding wheels, and with the switching element for lifting the grinding tool surfaces off the rail if the presettable grinding pressure is exceeded, the control device is connected, since the strain gauges provide an exact measurement value for the grinding surface position even over a long period of time, even under difficult operating conditions allowed due to the grinding dust.

According to a further feature of the invention, it is provided that the desired distance between the grinding machine surfaces and the reference base, in particular formed by the machine frame and / or a reference straight line independently guided on the track, the distance between the reference base and one by the height or lateral guide members corresponds to the same leading connecting line, wherein preferably the height or side guiding elements of the reference straight line or the machine frame are formed by rollers which can be deflected on the rail surface or track guidance parts which can be placed on the rail head flanks and whose areas on the top of the rail head or on the rail head flanks which can be fitted without play are the reference points of the connecting line form, the height and lateral guide members are formed by the rollers or wheel flanges of flange wheels. The limitation of the infeed movement along a precisely defined connection line between height and side guide elements creates a precisely constant basis for all grinding tools used and the creation of a uniform, continuously continuing height or side profile of the rail surface to be machined. By guiding the reference base or the machine frame corresponding to the rail vehicles, a decrease and restoration of the rail surface profile that is fairly well adapted to the actual conditions is also achieved. Above all, the tracking conditions that occur during rail operation can also be used directly as the starting point for grinding the tracking areas of the rails are used, so that in particular the changes in the area of the rail inspection flanks which actually have a detrimental effect on the track guidance can be eliminated by appropriate management of the tail flanges or grinding tool. In addition, the use of the machine frame as a measuring base from Vertell is possible, since it enables a solid basis for the readjustment movements and for the control of the grinding tools or their pulling and pulling movements, while at the same time a plane-parallel guidance of the grinding surfaces of the grinding tool to the connecting line of the guide gears can be achieved is.

It has also proven to be particularly expedient to design the rail grinding machine with at least one tool frame guided free of play on each of the two rails, on which at least two grinding tools, which are height-adjustable together with the latter, are arranged one behind the other in the longitudinal direction of the track and which are parallel to the connecting line for height adjustment of the grinding surfaces of the grinding tools the trolleys of the machine frame are mounted on the machine frame via guide members preferably arranged in a plane perpendicular to this connecting line. According to the invention, this machine is characterized in that at least one grinding tool of the tool frame is assigned a further measuring device and this via the control device or unit with the control valve arrangement assigned to the grinding tool group setting drive for limiting the infeed movement of the grinding tool surfaces when the desired distance between the Reference base and these grinding surfaces and, if necessary, at the same time falling below the total grinding pressure determined by the number of grinding tools of each grinding tool group and the permissible pressure load of the grinding tools. The use of the tool frame with a plurality of grinding tools simplifies both the structure of the setting drives or the associated control devices or units, the advantages according to the invention now being achievable even when using grinding tool groups. This means that machines that are already in use can be easily retrofitted with such grinding tool groups. Furthermore, regardless of the respective permissible total grinding pressure, grinding too deep areas with only one grinding tool can be sufficiently avoided even if several grinding tools are arranged on a tool frame.

Finally, according to the invention, it is also possible that each grinding tool, each grinding tool group is assigned a further measuring device and its own setting drive, which is arranged between the grinding tool and the tool frame and is connected to a control device or unit. The universal re-adjustment of the individual grinding tools compared to the tool frame thus created enables optimal use of the removal heights of each individual grinding tool, which ensures that the grinding tools are adjusted in accordance with the achievable removal heights and enables tracking corresponding to the rail surface trend. Furthermore, this opens up the possibility of controlling a fine adjustment of the grinding tools or the grinding surfaces with respect to the tool frame, so that the offset of the grinding surfaces by the possible removal amount can be achieved.

• Fig. 1 in Seitenansicht und stark vereinfachter Darstellung einen Maschinenrahmen einer fahrbaren Schienenschleifmaschine mit Schleifsteinen, wobei der Höhenverlauf der Schienenoberfläche zum besseren Verständnis stark verzerrt und vergrößert dargestellt ist,
• Fig. 2 in Seitenansicht und ebenfalls schematisch eine andere Ausführung eines Maschinenrahmens einer fahrbaren Schienenschleifmaschine mit rotierbaren Schleifwerkzeugen und einer durch ein Bezugssystem gebildeten Bezugsbasis,
• Fig. 3 eine Stirnansicht des Werkzeugrahmens gemäß den Linien III-III in Fig. 2 und
• Fig. 4 eine weitere Ausführung einer Meßvorrichtung für die Vermessung der Veränderungen der Schleiffläche eines Schleifsteines.

For a better understanding of the present invention, this will be explained in more detail with reference to the exemplary embodiments shown in the drawing. It shows

• 1 is a side view and a greatly simplified illustration of a machine frame of a mobile rail grinding machine with grinding stones, the height profile of the rail surface being greatly distorted and enlarged for better understanding,
• 2 in side view and also schematically another embodiment of a machine frame of a mobile rail grinding machine with rotatable grinding tools and a reference base formed by a reference system,
• Fig. 3 is an end view of the tool frame along the lines III-III in Fig. 2 and
• Fig. 4 shows another embodiment of a measuring device for measuring the changes in the grinding surface of a grindstone.

Fig. 1 shows a chassis frame 1 of a particularly self-propelled rail grinding machine 2, for grinding irregularities on the rail running surface or top of the rail head. A machine frame 3 is supported by running gear 4 on the rails 5 of the track, the longitudinal direction of the rail surface of which is greatly enlarged and distorted in the longitudinal direction for a better understanding of the present invention. Grinding tools 8, which are formed by grindstones 9, are arranged on a tool frame 10 or 11 for machining the top side 6 of the rail head and the inner flank 7 of the rail head. Each of the tool frames 1o and 11 is connected to the machine frame 3 via an adjusting drive 12 and 13 - hydraulically actuable cylinder-piston arrangements 14. Furthermore, the tool frames have 1 ₀ and 11, guide posts 15 and 16 which are supported in guides of the machine frame 3 to the amount of slidable.

A reference base 17 which determines the desired longitudinal course of the rail surface is formed by the machine frame 3, which is guided free of play via the rollers 18 and tracking parts 19 of the flanged wheels 2o of the flange wheels 2o of the undercarriage 4 on the top side 6 of the rail head and the flank 7 of the rail head. The vertical load on the machine frame 3 is z. B. caused by the supportable on the chassis frame 1 stroke drives 21 and the play-free contact of the tracking parts 19 by an expansion drive 22.

According to the invention, to determine and / or display the distance between the grinding surface 23 of at least one grinding tool 8 and the reference base 17 formed by the machine frame 3, this grinding tool 8 or the tool frame 10 or 11 receiving it - as in the present exemplary embodiment - assigned a measuring device 24. This now for the first time arranged further measuring device 24, like a measuring device 25 for determining the grinding pressure, and the tool frame adjusting drive 12, 13 are operatively connected to a control device 26, which is only shown in connection with the tool frame 11 and is designed for grinding pressure monitoring and height adjustment.

The further measuring device 24 comprises two transducers 27, 28 which are attached to the machine frame 3. The transducer 27 is designed, for example, as a rotary potentiometer and has a pivotable sensor arm which is connected to a sensor rod 29 provided with a roller for support on the top of the rail head 6. The sensor rod 29 is supported on the machine frame 3 by a spring for supporting the roller on the top of the rail head 6 without play. The sensor 27 can thus be used to determine the distance between the top of the rail head 6 and the reference base 17. If the grinding surface 23 of the grinding tools 8 is in engagement with the upper side 6 of the rail head, then the distance determined with the sensor 27 corresponds at the same time to that Distance between the grinding surface 23 and the reference base 17. The transducer 28 consists, for example, of a slide potentiometer which is provided with a pointer and a scale for the additional visual display of the distance between the machine frame 3 and the tool frame 11. Within the scope of the invention, however, it is of course possible to use the transducers 27 and 28 by any electrical, electromechanical, optical or the like. Other circuit and measuring devices for determining the desired distances between the grinding surfaces, tool frame, reference base and the like. B. rotary encoders, rotary transformers, light barrier arrangements and the like.

Furthermore, in this exemplary embodiment, the output of the measuring value transmitter 27, with the interposition of a switching element 3o, and the measuring value transmitter 28 are each directly connected to a storage device 31, which are combined in a control unit 32. which also includes a difference-forming element 33 connected to the outputs of these memory devices 31. Its output is applied to a control device 34 formed by a display device and to the drive of a control valve arrangement 35 of the control device 26. The control device 26 further comprises two hydraulic control circuits for monitoring the grinding pressure, which can be charged via a pressure medium pump and each have a pressure medium reservoir 36, 37, which are designed for a different operating pressure. The pressure medium reservoir 36 is above the control valve arrangement 35 with the pressure guard 38 formed measuring device 25 in connection, from which a pressure supply line 39 leads to the cylinder pressure building up the grinding chamber of the adjusting drive 13. The opposite cylinder chamber is connected via a pressure feed line 40 and the control valve arrangement 35 directly to the pressure medium reservoir 37, which is designed for a lower operating pressure.

For the independent forward movement of the mobile rail grinding machine 2, a drive arrangement 41 for generating energy for supplying the various drives and devices and for building up the operating pressure in the pressure medium stores 36 and 37 can be provided on the chassis frame. During the grinding operation, the chassis frame 1, as indicated by the arrows 42, is advanced in one direction or the other essentially continuously (ie at an approximately constant speed of, for example, 30 km / h), while the machine frame 3 is additionally driven by a thrust drive 43 is set in a pulsating and reciprocating longitudinal movement indicated by the arrows 44 relative to the continuously moving chassis frame 1. The grinder can e.g. B. according to the statements in the Austrian applications A 1150/77 and A 6443/77. Furthermore, as indicated, the switching element 3o additionally or exclusively via its own control line with a, for. B. arranged on one or both of the guide columns 16, strain gauges 45. The sensitivity of the strain gauge is adjusted so that a control signal is emitted when a grinding action occurs between one of the grinding surfaces 23 and the top of the rail head 6. However, this strain gauge 45 can of course also be provided in the area of the attachment point of the grindstones 9 on the tool frame 10 or 11, in order to be able to determine in each case with which grindstones 9 a grinding effect is exerted.

Furthermore, a connecting line 46 is shown in FIG. 1, which touches the rollers 18 in the areas facing the top of the rail head 6. This connecting line 46 thus represents a parallel to the machine frame 3 forming the reference base 17. This connecting line 46 shows the desired target height profile of the upper side of the rail head 6. The upper side of the rail head projecting above this connecting line 46 in the direction of the machine frame 3 are to be ground down - since they represent so-called wave crests , while the rail head top areas falling below this connecting line 46 - as shown, for example, in the area of the tool frame 11 - since they are already under the desired rail head top longitudinal profile, should not be ground or should only be ground in a subsequent grinding process when the adjacent rail head top areas are already in the same Height.

• Am Beginn des Arbeitseinsatzes wird die Meßvorrichtung 24 sowie die Steuereinheit 32 bzw. der Antrieb der Steuerventilanorndung 35 der Steuervorrichtung 26 derart justiert, daß bei Erreichen eines Abstandes h der Schleiffläche 23 - eines Schleifwerkzeuges 8 des Werkzeugrahmens 1o oder 11 - von dem, die Bezugsbasis 17 bildenden Maschinenrahmen 3 der Antrieb der, in der Herstellung dargestellten, Steuerventilanordnung 35 mit einem Schaltsignal der Meßvorrichtung 24 beaufschlagt wird. In der dadurch erreichten Arbeitsstellung wird das in der Druckzuleitung 4o bzw. in der unteren Zylinderkammer des Einstellantriebes 13 befindliche Hydraulikmedium vom Druckmittelspeicher 37 getrennt. Dadurch wird die Abwärtsbewegung des mit der Kolbenstange verbundenen Werkzeugrahmens 11 begrenzt.

The operation of the rail grinding machine according to the invention is now as follows:

• At the start of the work, the measuring device 24 and the control unit 32 or the drive of the control valve arrangement 35 of the control device 26 are adjusted such that when a distance h of the grinding surface 23 - a grinding tool 8 of the tool frame 10 or 11 - is reached, the reference base 17 forming machine frame 3, the drive of the control valve arrangement 35 shown in the manufacture is acted upon by a switching signal of the measuring device 24. In the working position thus achieved, the hydraulic medium located in the pressure feed line 40 or in the lower cylinder chamber of the adjusting drive 13 is separated from the pressure medium reservoir 37. This limits the downward movement of the tool frame 11 connected to the piston rod.

To determine the distance h between the grinding surface 23 and the reference base 17, the grinding surface 23 is moved downward with the adjusting drive 13 until it rests on the top side 6 of the rail head. This can be seen from a pressure increase in the pressure feed line 39, as a result of which the contact of the switching element 3o is closed via the pressure switch 38. When the grinding surface 23 lies firmly on the top of the rail head 6, the height of the adjacent roller of the sensor rod 29 can thus be used as a measurement basis for determining the distance of the grinding surface 23 from the reference base 17 using the output signal from the transducer 27. In contrast, the measured value output by the transducer 28 corresponds to the distance v of the tool frame 11 from the reference base 17. The difference x between the grinding surface 23 and the tool frame 11 can be determined by forming the difference between the measured values of the sensors 27 and 28.

In one storage device 31 that measured value - target distance v - is then stored, when it occurs the grinding surface 23 is at a distance h below the machine frame 3 and the control valve arrangement 35 is actuated to limit the infeed movement. This reliably prevents - as shown in connection with the tool frame 11 in Fig. 1 - the grinding surface 23 exceeds the desired distance h. During the grinding process, however, the distance of the grinding surface 23 from the tool frame 11 is constantly changed due to the wear of the grinding stones 9. Therefore, each time a grinding effect of the grinding surface 23 is exerted on the top of the rail head 6 - the grinding effect can be determined, as already explained above - the measured value present at the transmitter 27 is fed via the switching element 3o to the further storage device 31. In the difference-forming element 33, this measured value is compared during the grinding process with the measured values continuously transmitted by the measuring sensor 28 and, in accordance with the wear of the grinding surface 23 or change in the distance x, the proportional distance v stored in the memory device 31 assigned to the measuring sensor 28 is changed proportionally, in particular increased . Thus, regardless of the wear of the grindstones 9, it is effectively ensured that the grinding Surfaces 23 of the same do not exceed the distance h and the longitudinal top areas of the rail head that are too low are not ground. If one of the grinding surfaces 23 of the tool frame 11 is now approaching during the forward movement - arrows 42 - a region of the rail head upper side 6 which is below the distance h from the reference base 17 - as shown, for example, in the region of the tool frame 1o - the grinding pressure 36 is used by the pressure accumulator 36 Grinding surface 23 exerted on the top of the rail head 6.

The grindstones 9 are pressed during operation with a force that is permissible for the grindstones onto the top of the rail head 6, the maximum permissible pressure load of the grindstones 9 being adapted to the value corresponding to the operating pressure of the pressure medium reservoir 36. This is dimensioned so large that the grinding surfaces 23 of both grindstones 9 can each be pressed onto the top of the rail head 6 with the permissible operating grinding pressure. However, since only one grinding surface 23 of a grindstone 9 can be used when approaching an elevated point or a shaft crest, the maximum permissible pressure load, that is the maximum pressure of the pressure medium reservoir 36, must be based on the grindstones 9 used. In order to avoid damage: u, the maximum permissible pressure load should at least correspond to twice the operating grinding pressure, or the pressure load on the individual grinding stones 9 z. B. to monitor with separate strain gauges 45. This so-called total pressure due to a too large grinding depth, e.g. B. at higher crests, the pressure medium is pressed from the upper cylinder chamber of the adjustment drive 13 - against the accumulator pressure - in the pressure medium reservoir 36. As a result, the tool frame 11 moves closer to the machine frame 3 and to the reference base 17. As soon as the total grinding pressure is undershot, the tool frame 11 again moves against the very minimal pressure in the lower cylinder chamber of the adjusting drive 13, which is determined by the operating pressure in the pressure medium reservoir 37 below, i.e. in the direction of the top of the rail head 6. This in turn continues until the grinding surface 23 has reached the distance h from the reference base 17, whereupon the tool frame 11 is blocked against further downward movement by actuating the control valve arrangement 35.

Just for the sake of order, it should be noted at this point that those rail areas which, as shown in FIG. 1 in the area of the tool frame 11, run below the connecting line 46 and are therefore not machined with the grindstones 9 of the tool frame 11, in most Cases do not remain unprocessed, but are also smoothed in a subsequent grinding process - after the adjacent shaft crests have been correspondingly ground off - so that, in the end, a continuously smoothed rail surface remains which has a rectilinear course defined by the reference base 17. By guiding the grinding tools relative to the connecting line, that this smoothing is possible with as little material removal as possible. This subsequent grinding process can take place, for example, by repeating driving on the track to be machined with the machine frame 3. However, two or more such machine frames are expediently arranged one behind the other in the longitudinal direction of the rails on such rail grinding machines 2, so that the rail surface 2 is smoothed as completely as possible when the rail grinding machine 2 is passed through.

FIG. 2 shows a machine frame 47 which, as described in FIG. 1, can be mounted in a height-adjustable manner on a chassis frame of a mobile rail grinding machine or itself forms the chassis frame of such a machine. On this machine frame 47, two tool frames 48, 49 are adjustably mounted along guide columns 5o mounted on the machine frame 47 with grinding tool group setting drives 51, 52. On each tool frame, two grinding tools 54 formed by rotating grinding wheels 53 are arranged one behind the other in the longitudinal direction of the track and are coupled to motors 55 via a drive shaft. The execution of the rail grinding machine of the tool frame and the grinding tools can preferably be carried out according to the Austrian applications A 9132/75 and A 9133/75. As a reference base 17, a flanged wheel 56, which is designed as a side and height guide member, serves on the rail 5 rade 57 - a wire rope - with which a sensor 58 interacts to determine the distance v between the tool frame 48 or 49 and the reference line 57. Another transducer 59 is used to determine the distance x between the grinding surface 60 of the grinding tools 54 and the tool frame 48 and 49. The transducers 58 and 59 are connected via amplifiers which are coupled to control devices or display devices for the distances v and x with their outputs applied to the inputs of a summing element 61. The output of this summing element 61 is connected to a control valve arrangement of a control device 62 and to a control device 63 formed by a display or recording device for the respectively existing distance h between the reference straight line 57 and the grinding surfaces 6o. The two cylinder chambers of the adjusting drive 51 formed by a hydraulically actuable piston-cylinder arrangement 64 are coupled via pressure medium supply lines and a pressure switch 65 to the control device 62, which is connected to a control unit 66 comprising the summing element 61 and the amplifier. In the present example, the grinding tool group setting drive 51 is pressurized by a constant pressure medium pump, while the second cylinder chamber of the hydraulically actuable piston-cylinder arrangement 64 is connected to a pressure medium accumulator.

Fig. 3 shows in an enlarged view that the transmitter 59 with a compared to the factory Tool frame 48 is provided by means of a spring pivotable sensor arm 67, which is provided at its end facing the grinding surface 60 of the grinding tool 54 with a diamond-coated or hardened sensor roller 68. Due to the constant and continuous determination of the position of the grinding surface 6o relative to the tool frame 48, the measurement value determination is possible both during grinding and in the idle state, so that the measurement value determination with the summing element 61 of the control unit 66 can be carried out continuously and continuously during the entire work. The wear state of the grinding tools can be determined at any time on the basis of the distance x displayed with the control device.

For both of those in Fi ^g . 2, the grinding tool groups 69, 70 formed from the tool frame 48, 49 and the associated two grinding tools 54, a separate control unit 66 is provided - only shown for the grinding tool group 69. Based on the desired height profile of the top of the rail head 6, which is indicated by the connecting line 71 in FIG. 2, which represents a parallel to the reference straight line 57 - it affects the areas of the flanged wheels 56 lying on the top of the rail head - the desired distance h becomes Grinding surfaces 6o determined by the reference straight line 57 and entered into the control unit 66. This target distance h is constantly and continuously compared with the output signal of the summing element 61 and if the two values match, the connection between the The top of the rail head 6 facing cylinder chamber of the grinding tool group setting drive 51 and the pressure medium reservoir associated therewith are interrupted by means of the control device 62. This avoids falling below the connecting line 71 and the grinding of areas lying below the desired height level of the longitudinal regions of the top of the rail head. Because the grinding tool group setting drives 51, 52 are designed to exert a grinding pressure on the tool frame 48 at twice the permissible grinding pressure of a rotating grinding wheel 53, a particularly favorable ratio between grinding wheel wear is achieved when both grinding tools are in contact - FIG. 2 grinding tool group 65 and grinding result achieved. The maximum allowable grinding pressure; the grinding tools 53 is designed in such a way that it corresponds to twice the value of the working grinding pressure, so that even if only one grinding wheel 53 is in engagement, the rail or the grinding tool is not destroyed.

In order to achieve an even finer regulation of the infeed and the most intensive use of the grinding tools 54 during a grinding process, the drive motors 55 can also be connected to the control unit 66. The grinding pressure or, if applicable, the infeed of the individual grinding tools 54 can then also be carried out as a function of the respective current consumption of the grinding tool motors in conjunction with the fully effective one The position of the grinding surfaces is monitored in relation to the reference line 57. In this case, it is then advantageous to assign each grinding tool 54 of the grinding tool groups 69, 7o its own sensor 59, as indicated by the broken line.

4 shows a further embodiment of a sensor for determining the wear of the grinding surface 72 of a grinding tool 8 formed by a grinding stone 73. The grindstone 73, as indicated by arrows 74 and 75, pressed onto the top of the rail head 6 of the rail 5, is simultaneously set into an approximately constant forward movement and a reciprocating thrust movement superimposed on it. An abrasion sensor 77, for example a lamella film 78, is glued onto an end face 76 of the grindstone 73. This can be made of a material with approximately the same abrasion properties as the grindstone 73, in which thin resistance wires or the like are cast. Depending on the wear of the grindstone 73, several of these resistance wires or lamellae 79 are ground away or interrupted and the change in resistance caused thereby is a measure of the abrasion of the grindstone. However, this also exactly determines the distance of the grinding surface 72, for example from a tool frame or the like, and achieves exact height control of the grinding tool 72 in relation to a desired longitudinal profile of the top of the rail, regardless of its wear.

It is particularly advantageous if this special embodiment of the sensor as abrasion sensor 77 is used in conjunction with the tool arrangement according to FIG. 1 - as indicated in the area of the grindstones 9 of the tool frame 11. The wear of each individual grindstone can thus be determined separately. By appropriate adjustment of the grindstones, for example also relative to the tool frame 11, it is therefore possible to grind the shaft combs to the desired longitudinal direction of the rail surface even with differently worn grindstones 9. Above all, this individual readjustment of the grinding tools enables the grinding tools to be used as intensively as possible, since all tools with full grinding pressure can be used on the rail surface due to the universal adjustability in the area of unevenness exceeding the connecting line.

Within the scope of the invention it is also possible to use any type of reference system, e.g. B. with a reference straight line formed by light rays, wires, rods or in particular by frame. The distance between the end points and that between them and the measuring devices can be based on different ratios, e.g. B. 1: 3, 1: 4 and the like., Adjusted to the respective wavelength of the bumps in the rail surface. If several machine frames or grinding tools are used, the reference systems assigned to them can have different ratios between the ends score and have the points of acceptance of the measuring devices for adaptation to different error lengths - corrugations, flinging points.

Claims (11)

1.Mobile rail grinding machine for grinding irregularities in the rail running surface, with at least one height and / or side via an adjusting drive (12, 13, 51, 52) relative to a machine frame guided on the track by means of trolleys (4) ( 3) adjustable grinding tool (8, 54) and with a measuring device (25) for limiting the grinding depth on the basis of the frame serving as a reference and with a control device (26, 62) assigned to the setting drive (12, 13, 51, 52), characterized that the grinding tool (8, 54) has a further measuring device (24) for determining and in particular displaying the distance (v, x) - in particular also during the grinding process - between its grinding surface (23, 6 ₀ , 72) and one the target -The course of the rail surface determining reference base (17) is assigned, with a control device (34, 63) and possibly the control device (26, 62) for the adjustment drive (12, 13, 51, 52) or with egg ner further control unit (32, 66) associated with the setting drive (12, 13, 51, 52) is operatively connected. 2. rail grinding machine according to claim 1, characterized in that the further measuring device (24) with the grinding surface (23, 6 ₀ , 72) of the grinding tool (8, 54), in particular a grinding stone (9), cooperating, preferably on the reference basis (17) arranged transducer (27, 59, 77). 3. rail grinding machine according to claim 2, characterized in that the transmitter by at least one on the grinding tool, in particular a grindstone (73), applied abrasion sensor (77), z. B. a lamella film (78) or carbon layer or the like. Is formed. 4. rail grinding machine according to claim 2, characterized in that the transmitter (59) by an electrical transducer, for. B. a rotary potentiometer, with a pivotable sensor arm (67), and one on the grinding surface (6 ₀ ), z. B. diamond-coated or hardened sensor roller (6S) is formed. 5. Rail grinding machine according to one of claims 1 to 4, characterized in that the further measuring device (24), on the grinding tool (8, 54) or a movement-connected support part, in particular a tool frame (10, 11, 48, 49) , arranged transducer (27, 59, 77) and a further transducer (28, 58) for determining the distance (v) between this grinding tool (8, 54) or supporting part and the reference base (17). 6. Rail grinding machine according to one of claims 1 to 5, characterized in that at least one of the transducers (27, 28, 58, 59) of the further measuring device (24) optionally via an input or .. storage device (31) and a subsequent difference formation - or summing element (33, 61) of the control unit (32, 66) with one in the pressure feed line (4 ₀ ) - by a hydraulic cylinder Piston arrangement (14, 64) formed adjustment drive (12, 13, 51, 52) - located control valve arrangement (35) of the control device (26, 62) or the control unit (32, 66) is connected, the control valve arrangement (35) to limit the infeed movement at a distance corresponding to the target distance between the grinding tool surface (23, 6 ₀ ) and the reference base (17) via the control device or unit (26, 62; 32, 66) to interrupt the pressure supply line (4o) is acted upon. 7. Rail grinding machine according to one of claims 1 to 6, characterized in that at least one of the transducers (27, 28) via one of a measuring device (25) for determining the grinding pressure when a grinding pressure occurs - in particular when exceeding one of the motors (55) of the rotatable grinding tools (54) supplied with motor current - switching element (3o) with the control device (26, 62) or the control unit (32, 66) for determining and / or displaying the distance (v, x) between the grinding surfaces (23 , 6 ₀ ) and the reference base (17) can be connected. 8. rail grinding machine according to one of claims 1 to 7, characterized in that the measuring device (25) by on parts of the tool frame (1 ₀ , 11, 48, 49), the machine frame (3, 47) or the supporting parts of the grinding tools ( 8, 54), in particular the grindstones (9) or the drive shafts of the rotatable grinding wheels (53) arranged strain gauges (45) and with the switching element (30) for lifting off the grinding tool surfaces (23, 6 ₀ ) is connected to the control device (26, 62) by the rail (5) when the presettable grinding pressure is exceeded. 9. Rail grinding machine according to one of claims 1 to 8, characterized in that the target distance between the grinding tool surfaces (23, 6 ₀ ) and, in particular by the machine frame (3, 47) and or or a reference line independently guided on the track (57), the reference base (17) formed corresponds to the distance (h) between the reference base (17) and a connecting line (46, 71) leading through the height or side guide members, preferably the height or side guide members of the reference line (57 ) or the machine frame (3, 47) are formed by rollers (18) that can run off the rail surface or track guidance parts (19) that can be attached to the rail head flanks, the areas of which can be applied without play to the top side of the rail head (6) or to the rail head flanks (7) Form reference points of the connecting line (46, 71), the height and lateral guide elements being formed by the rollers (18) or wheel flanges (19) of wheel flanged wheels (2o, 56). 1o. Rail grinding machine according to one of claims 1 to 9, with at least one tool frame guided free of play on each of the two rails, on which at least two, together with these height-adjustable grinding tools are arranged one behind the other in the longitudinal direction of the track and which are parallel to the connecting line for the height adjustment of the grinding surfaces of the grinding tools Chassis of the machine frame Are mounted on the machine frame, preferably in a plane arranged perpendicular to this connecting line, on the machine frame, characterized in that at least one grinding tool (8, 54) of the tool frame (1 ₀ , 11, 48, 49) is assigned a further measuring device (24) and this via the control device or unit (26, 62; 32, 66) with the control valve arrangement (35) assigned to the grinding tool group setting drive (51, 52) to limit the infeed movement of the grinding tool surfaces (23, 6 ₀ , 72) when the Target distance (h) between the reference base (17) and these grinding surfaces (23, 6 ₀ , 72) and, if necessary, if the number of grinding tools (8, 54) of each grinding tool group (69, 7 ₀ ) and the number falls below permissible pressure load of the grinding tools (8, 54) is determined by the total grinding pressure. 11. Rail grinding machine according to claim 1 ₀ , characterized in that each grinding tool (8, 54) each grinding tool group (69, 7 ₀ ) a further measuring device (24) and its own between the grinding tool (8, 54) and the tool frame (1 ₀ , 11, 48, 49) arranged, associated with the control device or unit (26, 62; 32, 66) is associated with the adjustment drive.

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