COOLANT NOZZLE CARRIER FOR A GRINDING MACHINE, GRINDING MACHINE WITH SUCH A COOLANT NOZZLE CARRIER AND METHOD FOR OPERATING A COOLANT NOZZLE CARRIER

Description

[0001] During grinding, the interaction between the grinding wheel and the workpiece can lead to significant heat generation, primarily due to friction and the shearing work performed when removing chips from the workpiece. If this heat is dissipated into the workpiece, it can lead to overheating, which can change the material properties of the workpiece, particularly leading to grinding burn. In addition, inadequate cooling can also lead to flying sparks or, in the presence of oil mist, to deflagrations.

[0002] To counteract such effects, it is known to use cooling lubricants during grinding, for example, oils or emulsions of oil with water and additives, which are sprayed via nozzles onto the point where heat is generated. This can significantly improve the productivity of the grinding machine and the quality of the manufactured workpieces, as well as the safety of the grinding machine.

[0003] However, it is critical to provide these cooling lubricants at the correct location at all times during the machining process. Therefore, it is known from the prior art, in particular from EP 3 208 037 B1, to arrange cooling lubricant nozzles on a movable cooling lubricant nozzle carrier, with which the position of the cooling lubricant nozzles can be adjusted. However, when using the previously known cooling lubricant nozzle carriers, the risk of collision with the workpiece, the clamping device, and other machine parts cannot be eliminated in some situations, or can only be avoided by making compromises regarding the precision with which the cooling lubricant is sprayed onto the machining location.Further cooling lubricant nozzle holders, grinding machines with such cooling lubricant nozzle holders and methods for operating such cooling lubricant nozzle holders are disclosed in DE 10 2016 012 904 A1, JP 2015 051478 A, DE 10 2015 116 035 A1, DE 10 2012 104 263 A1, WO 2014 / 035789 A1, EP 1 886 764 A1, DE 200 05 648 U1 and US 4 929 130 A. In particular, DE 10 2016 012 904 A1 discloses a cooling lubricant nozzle holder with the features of the preamble of patent claim 1.

[0004] The object of the invention is to provide a cooling lubricant nozzle holder for a grinding machine, a grinding machine with such a cooling lubricant nozzle holder, and a method for operating a cooling lubricant nozzle holder that improves the collision prevention and enables increased precision in the provision of the cooling lubricant at the location where it is needed. This object is achieved by a cooling lubricant nozzle holder having the features of patent claim 1, a grinding machine having the features of patent claim 10, and a method for operating a cooling lubricant nozzle holder having the features of patent claim 15. Advantageous developments of the invention are the subject of the respective dependent claims.

[0005] The cooling lubricant nozzle holder according to the invention for a grinding machine has a central leg and two side legs arranged on the central leg so as to be movable relative to the central leg and has at least two cooling lubricant nozzles, of which at least one is arranged on each of the side legs.

[0006] The middle leg can also be formed by an existing component of a grinding machine, for example the spindle console.

[0007] What is essential to the invention is that the side legs are each mounted so as to be movable relative to the center leg that the cooling lubricant nozzle arranged on a respective side leg moves together with the side leg on a section of a circular path when the respective side leg moves, so that the cooling lubricant nozzles can be positioned at least in sections around a grinding wheel whose drive axis forms the center axis of the circular path.

[0008] The two coolant nozzles can be used as a cooling nozzle and a quenching nozzle, respectively. This means, in particular, that no coolant nozzle needs to be able to be guided more than 180° around the grinding wheel, thus avoiding ring-shaped coolant nozzle carriers, which pose an increased risk of collision. At the same time, this increases the range of possible coolant positions.

[0009] The separate adjustability of the two cooling lubricant nozzles supports optimal placement of the cooling lubricant and helps to reduce the risk of collision, while the ability to move along a circular path ensures positioning on the circumference of the grinding wheel, which greatly reduces the risk of collisions with the workpiece.

[0010] To minimize the risk of collision, it is particularly advantageous if the side legs are driven by a drive so that they can be moved individually. Various drive types are possible; in addition to (gear) motors, hydraulic, pneumatic, or mechatronic drives can also be used.

[0011] To further optimize the position of the cooling lubricant jets ejected by the cooling lubricant nozzles, it is helpful if at least one cooling lubricant nozzle is driven by a motor, in particular a geared motor, so that it can be individually pivoted or rotated relative to the side leg on which it is arranged. In an advantageous embodiment, this can be achieved by arranging an external toothing on a holding section of the cooling lubricant nozzle, which interacts with a rack section or gear segment moved by the motor.

[0012] It is particularly preferred if the cooling lubricant nozzles are interchangeable, so that the cooling lubricant nozzles can be adapted to the grinding wheel used.

[0013] One concrete way to achieve this is to attach the cooling lubricant nozzles to the side legs with a bayonet lock; however, other mechanical connections that can be quickly established and removed are also applicable.

[0014] It is also preferred if an additional cooling lubricant nozzle is arranged on the center leg, which can be used in particular as a flushing nozzle. To enable adjustment of the emitted cooling lubricant jet here as well, the additional cooling lubricant nozzle can have a replaceable nozzle plate—for example, after loosening a screw connection.

[0015] It has proven particularly advantageous if the side legs are shaped like a circular sector. For the purposes of this description, a side leg is particularly shaped like a circular sector if at least one of its surfaces running parallel to the plane of the circular path on which the side leg is at least partially displaceable relative to the center leg has the shape of a circular sector, which may optionally also have holes.

[0016] A further reduction in the risk of collision and an increase in the degrees of freedom of movement of the cooling lubricant nozzle carrier are achieved by the fact that, according to the invention, the side legs are offset from one another relative to the center axis of the circular path on which the cooling lubricant nozzles move together with the side leg during the movement of the respective side leg. In particular, this enables the side legs to be moved into positions in which both cooling lubricant nozzles are positioned relatively close to the center leg.

[0017] The grinding machine according to the invention with a control system, which can be designed in particular as a CNC control system, with a workpiece holder for receiving a workpiece to be machined and with a grinding wheel arranged on a driven axis is characterized in that the grinding machine further comprises a cooling lubricant nozzle holder according to the invention.

[0018] Preferably, the controller is designed and configured to operate two cooling lubricant nozzles arranged on different side arms either as a cooling nozzle or as a quenching nozzle. In other words, the controller can simply swap the roles of the cooling lubricant nozzles, which may, in particular, also be accompanied by a change in the running direction of the grinding wheel.

[0019] If the control system is designed and configured to change the position of the cooling lubricant nozzles during operation, it is possible to react immediately to shifts in the grinding point, for example due to wear of the grinding wheel, changes in the grinding strategy or special features of the workpiece geometry.

[0020] In an advantageous development of the grinding machine, the grinding machine is provided with a device for the automated replacement of the cooling lubricant nozzles, for example, a robotic arm, a linear handling system, or cooling lubricant nozzle holders, into which the cooling lubricant nozzles can be deposited and from which they can be retrieved by the grinding spindle using the pick-up method. In this way, for example, an automated change of the grinding wheel can be monitored without access to the machining area.

[0021] In some embodiments of the grinding machine, the center leg of the coolant nozzle holder can also be formed by an existing component of the grinding machine, in particular by a bracket of a spindle of the grinding machine. The coolant nozzle holder therefore does not necessarily have to be formed by a completely separate assembly.

[0022] In the method according to the invention for operating a grinding machine according to the invention, one cooling lubricant nozzle is used as the cooling nozzle and one cooling lubricant nozzle is used as the quenching nozzle. It is characterized in that during grinding, at least one of the cooling lubricant nozzles is moved along at least a portion of a circular path. This circular path expediently runs around the grinding wheel of the grinding machine.

[0023] It is particularly advantageous if the method allows the direction of rotation of the grinding wheel to be changed at least once during grinding and the role of the cooling lubricant nozzles to be exchanged and / or if one of the cooling lubricant nozzles is rotated at least once during grinding relative to the side leg to which it is attached in order to react to changes in the grinding geometry in situ during grinding.

[0024] The invention is explained in more detail below with reference to figures showing exemplary embodiments. It shows: Fig. 1: A view into the machining area of ​​a grinding machine; Fig. 2: A cooling lubricant nozzle holder, attached to the console of the grinding spindle; Fig. 3: The cooling lubricant nozzle holder made of Fig. 2 from the front; Fig. 4: the cooling lubricant nozzle holder Fig. 2 from one side; Fig. 5: the cooling lubricant nozzle holder from Fig. 2from below; and Fig. 6: the cooling lubricant nozzle holder from Fig. 2 from the other side.

[0025] Since the same embodiment of the invention is depicted in the figures, the same reference numerals are used. However, for the sake of clarity, not all reference numerals are shown in all figures.

[0026] Figure 1 shows a grinding machine 1 in a perspective that primarily allows a view into its machining area 2 in which the machining of the workpiece 3 to be machined takes place.

[0027] For this purpose, the workpiece 3 is clamped, for example, in the workpiece carrier 4, so that it can rotate about its longitudinal axis. The workpiece carrier 4 is arranged so that it can move on a carriage 5. The workpiece 3 is machined with the grinding wheel 6, which can be driven in both directions of rotation by means of a driven axis 7 and, together with the driven axis 7 and the associated drive, can be moved relative to the workpiece carrier 4 in several degrees of freedom.

[0028] A special feature of the Figure 1 grinding machine 1 shown is the cooling lubricant nozzle holder 100, which is also described below with reference to the Figures 2 to 6 , which show different views of the cooling lubricant nozzle carrier 100, are explained in more detail.

[0029] The cooling lubricant nozzle carrier 100 has, as in each of the Figures 2 to 6As can be seen, two cooling lubricant nozzles 110, 120, each arranged in the end region of one of the two circular-ring-sector-shaped side legs 130, 140. The circular-ring-sector-shaped side legs 130, 140 are mounted on a central leg 150 in such a way that they are each movable in a plane perpendicular to the axis 7 of the grinding wheel 6 along a circular path, which can in particular be defined by a center line of the circular-ring-sector-shaped side legs 130, 140. Accordingly, the cooling lubricant nozzles 110, 120 can be freely positioned around the grinding wheel 6 on a circular path, which can in particular run parallel to the circumference of the grinding wheel 6, wherein by means of a particularly well-positioned Figure 5recognizable offset of the circular sector-shaped side legs 130, 140 in the direction of the driven axis 7 to each other ensures that a collision of the circular sector-shaped side legs 130,140 with each other is avoided in all positions.

[0030] In order to nevertheless enable a symmetrical arrangement of the cooling lubricant nozzles 110, 120, the spray heads 111, 121 of the cooling lubricant nozzles 110, 120 are fastened to holding sections 112, 122 of the cooling lubricant nozzles 110, 120, which have a different length adapted to the offset of the annular side legs 130, 140.

[0031] The holding sections 112, 122, within which the supply lines (not shown in the figures) through which the spray heads 111, 121 are supplied with cooling lubricant also run, can, in a preferred embodiment, be connected via a bayonet lock to the circular sector-shaped side legs 130, 140 and to the cooling lubricant supply lines arranged in or on them. With this type of connection, the necessary sealing against the escape of cooling lubricant can be easily achieved, for example, by compressing a sealing element, e.g., a sealing ring, in the transition area between the respective supply lines.

[0032] On the other hand, the production and release of the connection can be carried out easily in an automated manner by using a robot arm or in the pick-up method carried out by the grinding spindle, for example when the grinding wheel 6 is changed and therefore spray heads 111,121 with a different shape are desired.

[0033] In the end region of the holding sections 112, 122 of the cooling lubricant nozzles 110, 120 facing the respective circular sector-shaped side legs 130, 140, an external toothing 113, 123 is also present. This external toothing enables rotation of the cooling lubricant nozzles 110, 120 by driven gear segments 132, 142, so that the direction in which the spray heads 111, 121 spray can be adjusted or adjusted. In this way, for example, a shifting grinding point, e.g., as a result of wear on the grinding wheel 6, can be easily compensated.

[0034] For this purpose, the gear segments 132, 142, the shape of which is adapted to that of the respective circular-ring-sector-shaped side leg 130, 140 on which they rest, are provided with a guide slot 132a, 142a into which pins or screws 130a, 140a engage, so that the gear segments 132, 142 are displaceable on the respective circular-ring-sector-shaped side leg 130, 140 in such a way that a section with internal toothing 132b, 142b interacting with the respective external toothing 113, 123 causes the holding section 112, 122 to rotate. This displacement is driven by motors 155, 156 arranged on the center leg, which interact via gear wheel arrangements 157, 158 with an external toothing 132c, 142c of the racks 132, 142 and which receive their travel commands from a control system of the grinding machine, in order to automatically move the cooling lubricant nozzles 110, 120 and bring them into the desired position.

[0035] At their edge facing away from the grinding wheel 6, the circular sector-shaped side legs 130, 140 each have external toothing 131, 141. This allows the circular sector-shaped side legs 130, 140 to be automatically moved and brought into the desired position via pinions 151, 152 or, if necessary, via a gear system with (gear) motors 153, 154 arranged on the center leg 150, which receive their travel commands from a control system of the grinding machine.

[0036] The drives, in particular the (geared) motors, and the cooling lubricant supply are designed in such a way that the nozzles can be adjusted during operation, in particular at a cooling lubricant pressure of more than 30 bar and a cooling lubricant volume flow of 260 l / min.

[0037] The cooling lubricant nozzles 110, 120 can be moved independently of one another and automatically, in particular CNC-controlled, due to these degrees of freedom of movement, so that one supplies cooling lubricant as a cooling nozzle for cooling the grinding point or workpiece in the direction of rotation of the wheel shortly before the current grinding point in order to avoid unacceptably high temperatures, while the other is used as an extinguishing nozzle for extinguishing / cooling sparks that have nevertheless occurred, which guides cooling lubricant past the grinding wheel after the grinding point close to the grinding wheel in the opposite direction of rotation of the grinding wheel.

[0038] The cooling lubricant nozzles 110, 120, the line systems by which they are supplied with cooling lubricant and the control of the cooling lubricant supply with regard to pressure and throughput volume of the cooling lubricant are adapted so that each of the cooling lubricant nozzles 110, 120 can be used both as a cooling and as a quenching nozzle, depending on the current direction of rotation of the grinding wheel 6. This design minimizes the risk of collision with the workpiece, clamping device or other machine components.

[0039] In addition, in the Figures 1 to 6 In the embodiment of the cooling lubricant nozzle carrier 100 shown in FIG. 1, a further cooling lubricant nozzle 160 is present, namely the one shown in FIG. Figure 3 Particularly clearly visible, fixed flushing nozzle on the middle leg 150 of the cooling lubricant nozzle holder, whose spray pattern is controlled by a replaceable nozzle plate 161, which can be Figure 5can be influenced particularly well. The flushing nozzle is typically operated with higher coolant pressure, for example 70 bar, and lower coolant flow rates, for example 30 l / min, than the cooling and extinguishing nozzles. List of reference symbols

[0040] 1Grinding machine 2Processing area 3Workpiece 4Workpiece carrier 5Slide 6Grinding wheel 7Axis 100Coolant nozzle holder 110, 120, 160Coolant nozzle 111, 121Spray head 112, 122Holding section 113, 123External gearing 130, 140Side legs 130a, 140aPins or screws 131, 141External gearing 132, 142Gear segment 132a, 142aGuide slot 132b, 142bInternal gearing 132c, 142cExternal gearing 150Center leg 151, 152Pinion 153, 154, 155, 156Motor 157, 158Gear assembly 161Nozzle plate

Claims

1. Cooling lubricant nozzle holder (100) for a grinding machine (1), wherein the cooling lubricant nozzle holder (100) comprises a middle shank (150) and two lateral shanks (130, 140) arranged on the middle shank (150) movably in relation to the middle shank (150), and wherein the cooling lubricant nozzle holder (100) comprises at least two cooling lubricant nozzles (110, 120), at least one of which is arranged on each of the lateral shanks (130, 140), wherein each of the lateral shanks (130, 140) are movably mounted in relation to the middle shank (150) such that each cooling lubricant nozzle (110, 120) which is arranged on one of the respective lateral shanks (130, 140) moves together with the lateral shank (130, 140) on a section of a circular path when the respective lateral shank (130, 140) moves, characterized in that the lateral shanks (130, 140) are arranged offset to each other in relation to the middle axis of the circular path on which the cooling lubricant nozzles (110, 120) move, together with the lateral shank (130, 140), when the respective lateral shank (130, 140) moves.

2. Cooling lubricant nozzle holder (100) in accordance with claim 1, characterized in that the lateral shanks (130β, 140) are powered by a drive such that they can be moved individually.

3. Cooling lubricant nozzle holder (100) in accordance with claim 1 or 2, characterized in that at least one cooling lubricant nozzle (110, 120) is driven by an engine (155, 156) such that it is individually pivotable.

4. Cooling lubricant nozzle holder (100) in accordance with claim 3, characterized in that the cooling lubricant nozzle (110, 120) which is driven by the engine (155, 156) is rendered pivotable by means of an outer toothing (113, 123) being arranged on a holding section (112, 122) of the cooling lubricant nozzle (110, 120) which engages with a section of a gear rack moved by the engine (155, 156) or with a gear wheel segment (132, 142) having an internal toothing (132b, 142b).

5. Cooling lubricant nozzle holder (100) in accordance with any of claims 1 to 4, characterized in that the cooling lubricant nozzles (130, 140) are exchangeable.

6. Cooling lubricant nozzle holder (100) in accordance with claim 5, characterized in that the cooling lubricant nozzles (110, 120) are attached to the lateral shanks (130, 140) by means of a bayonet fitting.

7. Cooling lubricant nozzle holder (100) in accordance with any of claims 1 to 6, characterized in that a further cooling lubricant nozzle (160) is arranged on the middle shank (150).

8. Cooling lubricant nozzle holder (100) in accordance with claim 7, characterized in that the further cooling lubricant nozzle (160) comprises an exchangeable orifice plate (161).

9. Cooling lubricant nozzle holder (100) in accordance with any of claims 1 to 8, characterized in that the lateral shanks (130, 140) have the form of an annular ring sector.

10. Grinding machine (1) having a controller, a workpiece holder (4) for holding a workpiece (3) intended for machining and a grinding disc (6) arranged on a driven axle (7), characterized in that the grinding machine (1) further comprises a cooling lubricant nozzle holder (100) in accordance with any of claims 1 to 9.

11. Grinding machine (1) in accordance with claim 10, characterized in that the controller is designed and configured to operate two cooling lubricant nozzles (110, 120), arranged on different lateral shanks (130, 140), either as a cooling nozzle for cooling the grinding area and / or the workpiece, by delivering cooling lubricant at a short distance in front of the current grinding point in the direction of rotation of the disc, or as an extinguishing nozzle for extinguishing and / or cooling arising sparks, which emits cooling lubricant near the grinding disc behind the grinding point in the direction opposite the direction of rotation of the grinding disc.

12. Grinding machine (1) in accordance with claim 10 or 11, characterized in that the controller is designed and configured to change the position of the cooling lubricant nozzles (110, 120) during ongoing operation.

13. Grinding machine (1) in accordance with any of claims 10 to 12, characterized in that the grinding machine (1) comprises an apparatus for the automated exchange of the cooling lubricant nozzles (110, 120).

14. Grinding machine (1) in accordance with any of claims 10 to 13, characterized in that the middle shank (150) is formed from a component of the grinding machine (1), in particular, from the console of a spindle of the grinding machine (1).

15. Method for operating a grinding machine (1) in accordance with any of claims 10 to 14, in which one cooling lubricant nozzle (110, 120) is employed as a cooling nozzle for cooling the grinding area and / or the workpiece, by delivering cooling lubricant at a short distance in front of the current grinding point in the direction of rotation of the disc, or as an extinguishing nozzle for extinguishing and / or cooling arising sparks, which emits cooling lubricant to the grinding disc behind the grinding point in the direction opposite the direction of rotation of the grinding disc, and one cooling lubricant nozzle (110, 120) is employed as an extinguishing nozzle for extinguishing and / or cooling arising sparks, which emits cooling lubricant to the grinding disc behind the grinding point in the direction opposite the direction of rotation of the grinding disc, characterized in that, during the grinding process, at least one of the cooling lubricant nozzles (110, 120) is moved on at least one section of a circular path.

16. Method in accordance with claim 15, characterized in that, at least once during the grinding process, the direction of rotation of the grinding disc (6) is changed, thereby interchanging the roles of the cooling lubricant nozzles (110, 120).

17. Method in accordance with claim 15 or 16, characterized in that, at least one during the grinding process, one of the cooling lubricant nozzles (110, 120) is rotated relative to the lateral shank (130, 140) to which it is attached.