EP3535092A1

EP3535092A1 - Honing machine having multiple workstations

Info

Publication number: EP3535092A1
Application number: EP17790759.9A
Authority: EP
Inventors: Johannes Lintner; Bernd Nagel; Karl-Günther Roth
Original assignee: Nagel Maschinen und Werkzeugfabrik GmbH
Current assignee: Nagel Maschinen und Werkzeugfabrik GmbH
Priority date: 2016-11-07
Filing date: 2017-10-25
Publication date: 2019-09-11
Anticipated expiration: 2037-10-25
Also published as: DE102016221777A1; WO2018082976A1; EP3535092B1

Abstract

The invention relates to a honing machine (100) for carrying out honing operations on at least one borehole in a workpiece (W), in particular for honing cylindrical boreholes in a cylinder crankcase, comprising a machine base (110), a support structure associated with the machine base, a machine upper part (120) supported by the support structure and arranged at a distance above the machine base, a transport system (130) for transporting workpieces (W) on a transport path (132), and multiple workstations (140, 160-1, 160-2, 160-3) arranged along the transport path. A workpiece can be transported successively to different workstations of the honing machine via the advancing movement of the transport system. At least one of the workstations is a honing station (160-1, 160-2, 160-3), having at least one horizontal carriage (190) which is supported by the machine upper part (120) and can be moved in a horizontal direction, wherein the horizontal carriage supports at least one honing unit (180-1, 180-2, 180-3, 180-4, 180-5, 180-6) having a honing spindle (184) which can rotate about a vertical spindle axis (187) and can move back and forth in parallel to the spindle axis. The horizontal carriage (190) supports a lifting carriage (310), which can be moved in a vertical direction, wherein the lifting carriage supports an overarm device (330) and a tool magazine (350) having multiple tool receiving means (360) for receiving a respective honing tool.

Description

Honing machine with several workstations

AREA OF APPLICATION AND PRIOR ART

The invention relates to a honing machine for performing honing operations on at least one bore in a workpiece, in particular for honing cylinder bores in a cylinder crankcase.

Honing is a geometrically indeterminate cutting process in which a multi-bladed bonded cutting tool during a honing operation in the bore performs a two-component working movement resulting in a characteristic surface texture of the machined inner surface, typically with crossed machining marks. The transferred from a honing spindle of a honing machine on the honing tool working movement therefore usually consists of an axially reciprocating stroke movement and one of these superimposed rotational movement. By honing finished surfaces can be produced, which meet extremely high requirements in terms of dimensional and form tolerances and in terms of the surface structure. Accordingly, in engine construction, for example, cylinder surfaces, i. Inner surfaces of cylinder bores in a cylinder crankcase (CCG) or in a cylinder sleeve to be installed in a cylinder crankcase, bearing surfaces for shafts, e.g. in a crankshaft bearing bore, or subjected to the cylindrical inner surfaces in connecting rod honing. Also bearing surfaces on connecting rods, gears or components for other power and working machines, such as compressors, are often processed by honing.

When machining cylinder treads, several different, successive honing operations are typically performed, e.g. a pre-honing to produce the required basic shape and a finish honing with which the surface structure ultimately required is generated. Measuring steps can be used to check the processing success.

In the mass production of cylinder crankcases and other workpieces to be machined by honing honing machines are often used with multiple honing units, for example, include a Vorhoneinheit and a finished honing unit, wherein a pre-honed workpiece can be transferred directly to the finished honing unit within the honing machine. Devices for further processes, such as measuring and deburring, can be integrated in such a honing machine. WO 2013/1 17482 A1 describes a honing machine for carrying out honing operations of cylinder bores in a cylinder crankcase. The honing machine has a machine base, a plurality of vertical stands arranged in the edge region of the machine base, and a machine head supported by the uprights, which is arranged at a distance above the machine base. On the machine base a rotary table is arranged to transport workpieces successively to different workstations of the honing machine. Two of the workstations are honing stations, each having at least one honing unit carried by the machine head, which has a honing spindle which is rotatable about a vertical spindle axis and reciprocable parallel to the spindle axis. The honing unit is mounted on a horizontally movable carriage carried by the machine head. In some embodiments, the honing unit may be moved to a tool changer using the carriage.

The utility model DE 20 2016 002 857 U1 describes honing machines with several honing stations in which a machine head is carried by a column and for transporting workpieces e.g. equipped with a rotary table circulating transport system is provided, which transports the workpieces on a running around the column transport path between workstations. Two of the work stations each are honing stations having at least one honing unit carried by the machine head, which has a honing spindle which is rotatable about a vertical spindle axis and reciprocable parallel to the spindle axis. The honing unit is mounted on a horizontally movable carriage carried by the machine head. In some embodiments, the honing unit may be moved to a tool changer using the carriage.

With Honmaschinen the types described is u.a. with suitable dimensioning and design of workpiece-dependent components. Complete machining of cylinder bores on cylinder crankcases with short non-machining times available. The honing machines are also characterized by a relatively compact design and therefore have only a small footprint. In addition, they can be relatively easily linked with other processing machines to processing lines.

TASK AND SOLUTION

The invention has for its object to provide a generic honing machine, which is characterized by high achievable productivity and flexibility at the same time very compact design. In particular, a compact honing machine is to be provided with a complete machining of cylinder bores on cylinder crankcases is possible with short non-productive times.

To solve this problem, the invention provides a honing machine with the features of claim 1. Advantageous developments are specified in the dependent claims. The wording of all claims is incorporated herein by reference.

The term "honing machine" refers to a numerically controlled processing machine with which at least one honing operation can be performed on a workpiece, so that the processing machine is suitable for honing. Optionally, the honing machine may additionally perform other, typically material-removing, machining operations on a workpiece, eg one or more drilling operations, a deburring operation or a fluid jet operation A workstation may also be integrated.

In the honing machines considered here, an honing station has at least one horizontal slide, which is carried by the machine upper part and which can be moved numerically in a horizontal direction by means of a horizontal slide drive. The horizontal carriage carries at least one honing unit, which has a honing spindle, which is rotatable about a vertical spindle axis and parallel to the spindle axis back and forth. Due to the arrangement on the horizontal slide, the honing unit or the honing spindle can be positioned in different positions in the horizontal direction.

It is possible to arrange a horizontal slide on an upper side of the machine head. Preferably, however, the horizontal slide is attached to a side surface of the machine head. As a result, mutual interference of horizontal slide can be better avoided even in a compact design.

The machine base or the machine base of the honing machine is assigned a support structure, so that there is a fixed spatial relationship between the machine base and the support structure. For example, the support structure may be mounted on the machine base so that the machine base supports the support structure. The support structure can also stand directly on the ground and only with the machine base screwed so that it acts mainly as a lateral support for the support structure.

The support structure is a load-bearing assembly for mechanical-functional components of the honing machine. These may be attached in large part or exclusively to the machine shell carried by the support structure. This applies in any case to the horizontal slides (one or more) and all components carried by a horizontal slide, e.g. the honing units. At and / or in the support structure or one of its constituents, e.g. Supply lines for electrical, pneumatic and / or hydraulic components run.

The honing machine has a transport system for transporting workpieces on a transport path. The transport system forms a machine-internal transfer system, with which a fast transfer of the workpieces between the individual workstations can be realized. The transport system may e.g. be mounted on the machine base. The term "transport path" here refers to the path that a transported workpiece can take during transport.

Along the transport path several workstations are arranged. A workpiece can be transported by moving the transport system successively to different workstations of the honing machine. When a work station is associated with at least one machining unit for performing a workpiece changing machining operation on the workpiece (e.g., a honing honing unit, a drilling unit for boring, a deburring unit for deburring, etc.), the workstation may be referred to as a machining station. Non-processing operations are also possible, e.g. a measuring station for carrying out measurements on workpieces, or a charging station.

Preferably, the transport system is designed as a circulation transport system for transporting workpieces on a revolving transport path. The circulating transport path is preferably closed in the direction of rotation, but this is not mandatory. By a machine-internal transfer along a circulating transport path, it is possible to make do with a single loading station for loading and unloading the workpiece holders. In contrast to transfer machines, it is thus possible for the workpieces to leave the honing machine at the same point at which they were fed to the honing machine. This facilitates the loading and unloading and in particular the coupling of the honing machine to an external conveyor system. It can also charge two charging stations be provided at different positions along the transport path, for example, one for loading and another for unloading the circulation transport system.

In principle, some advantages of the claimed invention can also be utilized if, instead of the circulating transport system, for transporting workpieces on an e.g. circular circulating transport path a linear transport system is used for transporting workpieces on a straight-line transport path. The workstations can therefore also be in line with each other, as in the case of a transfer machine.

With the aid of an external conveying system, the honing machine can be linked with other honing machines and / or with other processing machines (for example, precision boring machines) as needed to form a production line. The arrangement can be used in combination with different loading and unloading concepts, e.g. with a gantry loader with a horizontally and vertically movable gripper arm, with a loading robot and / or with a shuttle carriage.

A honing unit carried by a horizontal carriage is horizontally positionable so that a bore of a workpiece, which has been transported by the transport system into the vicinity of or into a working position of the honing station, can be honed by means of a honing tool carried by the honing spindle , If the transport system is set up so that a workpiece is transported directly to a working position or processing position of the honing station by means of the transport system, the functions of workpiece transport and workpiece positioning are realized by the transport system and no separate transfer is required. It is also possible to separate the functions of workpiece transport and workpiece positioning. Then it is sufficient if the workpiece is transported by means of the transport system in the vicinity of a working position or machining position, that the workpiece is then brought by a simple further operation in the desired working position or machining position.

A special feature is that the horizontal carriage carries a lifting carriage, which is moved numerically controlled by means of a lifting slide drive in a vertical direction. The honing machine thus has a further machine axis which can be controlled via the control unit of the honing machine and which can bring about a controlled lifting movement of the lifting carriage. The lifting carriage carries further functional components of the honing machine, namely a counter-holding device and a tool magazine with a plurality of workpiece holders for receiving a respective honing tool. According to another formulation, the solution may be possibly also be described so that the lifting carries a counter-holding device with integrated tool magazine. According to another formulation, a tool magazine which can be moved vertically by means of the lifting carriage is provided, which can be regarded as part of a vertically movable counter-holding device.

These devices are horizontally movable by means of the horizontal slide together with the honing unit. By means of the lifting carriage, a vertical movement independent of the movements of the honing spindle can be carried out. The counter-holder device and the tool magazine offer further important functionalities of honing processing, which can be mounted in a spatially compact form on the horizontal slide and moved or positioned together with the honing unit by movement of the horizontal slide.

The counter-holder device is designed so that, if necessary, it can receive vertically upward machining forces during honing. The counter-holding device is independent of the honing spindle parallel to the spindle axis, so moved in the vertical direction and can be placed on the workpiece as required for machining the workpiece with specifiable bearing force to keep it in the vertical direction without play (pressure near zero) or if necessary, hold down with a certain pressure. This allows the use of workpiece holders, which do not have their own clamping device for securing the workpiece against lifting during honing. This ensures a trouble-free honing without lifting the workpiece from the workpiece holder in each case. The counterhold device is present, it does not necessarily have to be used in every machining operation.

By integrating a horizontally moving tool magazine on the horizontal slide, the tool change function can be permanently positioned in spatial proximity to the honing unit or the honing spindle. Can therefore be dispensed with a tool changing device with a separate from the honing unit tool magazine. The horizontal travel of the horizontal carriage can thus be designed substantially shorter than in conventional honing machines, in which using the horizontal carriage an external tool change was approached (see, for example, Fig. 2 in WO 2013/1 17482 A1). The length of the travel path of the horizontal carriage only needs to be so great that all horizontal movements required during the machining of a workpiece and all travel paths required for adapting the honing machine to different tool dimensions are provided. The travel can be eg at a maximum of 500 mm. If all required travels are relatively short, it is possible to use the honing machine in each direction in which a horizontal slide is moved to keep relatively short or compact.

Different solutions are possible for the design of the tool magazine. The tool magazine can be designed, for example, as a linear magazine. In preferred embodiments, the tool magazine is designed as a round magazine. As a result, a compact design with a favorable ratio between the number of available tool holders and the lateral dimensions of the tool magazine can be achieved. The round magazine may, for example, have an annular arrangement with four to twelve tool holders, in particular with six or eight tool holders.

In a development are workpiece holders of the round magazine on a pitch circle, which extends through the extension of the spindle axis. In this case, by rotation of the round magazine about a vertical magazine axis of rotation by means of a magazine drive, one of the workpiece holders can optionally be brought into a tool changing position, which lies in extension of the spindle axis.

In one embodiment, it is provided that each of the workpiece holders has a vertical through opening for passing a honing tool and a tool holding device for holding a honing tool in the through hole, wherein the tool holder is switchable between a holding configuration and a release configuration. The changeover can be done automatically as required or automatically by means of a controlled actuator.

In some embodiments, the tool magazine is equipped with additional features for additional functionality. In some embodiments, each of the workpiece holders is assigned a centering device for centering the honing tool for insertion into a bore to be machined. The centering device may have a preferably diameter-dependent flushing ring, which in addition to the centering function also has the function of the controlled supply of cooling lubricant into the bore during honing. It can thus be provided a centering and flushing ring. It is also possible to design a centering device as Konuszentrierung.

In many cases honing tools are equipped with components of a measuring system for measuring the bore before and / or during and / or after honing. Often this is a pneumatic bore measuring system with one or more measuring nozzles attached to the honing tool, which have a robust diameter measurement or Allow shape measurement of the hole with high accuracy. In some embodiments, each of the workpiece holders is associated with at least one reference ring for referencing the bore measuring system of the honing tool. This makes it possible to refer to the bore measuring system at appropriate times on a reference ring exactly known inside diameter to ensure long-term high measurement accuracy.

In order to optimize the counter-holding function of the vertically movable assembly, at least one pressure element for placement on the upper side of the workpiece may be attached to each of the tool holders on a workpiece-side end. The pressure elements may be, for example, workpiece-dependent pressure rings or other, optionally interchangeable pressure pieces. A pressure element may be made of a resilient, somewhat yielding material, such as e.g. Hard rubber or plastic, exist, whereby a particularly gentle surface pressure on the workpiece is possible. Pressure elements of metal, e.g. Steel or a softer metal, e.g. Aluminum, are also possible. Pressure elements are functional components of the counterholder device and provide at least one contact surface for placement on the workpiece top side.

There are different design options for the support structure. The support structure may, for example, comprise two, three, four or more uprights which are arranged on and / or on the machine base such that they are located outside the transport path and the working space between the uprights is freely accessible from the side (cf., for example, WO 2013/1 17482 A1).

In an embodiment with a circulation transport system, the support structure has an inner column and the circulation transport system is designed for transporting workpieces on a transport path extending around the inner column. This ensures good accessibility of the area of the transport path from all sides. The term "pillar" generally refers to a free-standing, load-bearing, inherently stable subassembly, which can consist of a single component or can be composed of several interconnected components The supporting function can be the main function of the inner column, so that it can be optimized for the carrying function.The inner column can be formed, for example, by a tube with a hollow interior a high level of stability and load carrying capacity can be achieved with a moderate weight and material usage.The tube can be a cylindrical tube (with a circular tube) Cross-section), other cross-sectional shapes, such as polygonal shapes, such as a triangular, square, in particular square, or a hexagonal (hexagonal) cross-sectional shape are possible. The inner column can also have one or more T-beams or one or more double-T beams or be formed by such a component. The inner column may have a torsion-resistant strut construction, which may be open or externally clad. The inner column may have a plurality of stacked column sections, which are detachably or firmly connected to each other.

In addition to the inner column, a second column, e.g. an arranged outside the transport path column, be present, which also serves as a carrier for the machine head and receives a portion of the load.

In order to enable high productivity, the honing machine preferably has two or more work stations designed as honing stations. In one embodiment, the honing machine has at least three workstations which are designed as honing station. In particular, exactly three honing stations can be provided. In one embodiment, a first honing station is disposed on a first side, a third honing station on a third side diametrically opposed to the first side, and a second honing station on the transport path between the first and third honing stations on a second side. If three sides of the honing machine are equipped with honing stations, a particularly space-saving arrangement of a plurality of honing units is possible.

Each of the honing stations preferably has a horizontal carriage and each of the honing units has the units (lifting carriage, counter-holder device, tool magazine) which can move in common with a honing unit.

Honing stations are possible which have only a single honing unit and accordingly only a single honing spindle. Higher productivity may provide embodiments in which at least one honing station has two or more honing units which can operate simultaneously. In some embodiments, three honing stations each having two honing units are provided, so that the honing machine is a six-spindle honing machine. This can be a good compromise between high productivity on the one hand and at the same time compact design on the other hand created.

There are different possibilities of designing a circulation transport system. Some embodiments are characterized in that the circulation transport system comprises a rotary table, which is rotatable about a vertical rotary table axis and a plurality Workpiece receivers, which are arranged at a radial distance to the rotary table axis in the circumferential direction offset from one another arranged such that a recorded in a workpiece holder workpiece by rotation of the rotary table can be transported successively to different workstations of the honing machine. In some variants, the rotary table is vertically movable by means of a lifting drive between a lower position and an upper position, so that the rotary table is designed as a lifting rotary table. Variants without lifting drive are also possible.

Further circulatory transport systems which can be used in the context of the honing machine are described in the utility model DE 20 2016 002 857 U1, the disclosure content of which is incorporated herein to the content of the present description.

The disclosure also relates to a manufacturing plant with a plurality of processing machines for processing a workpiece and with a conveyor system for conveying workpieces to the processing machines and from the processing machines. At least one of the processing machines is a honing machine according to the claimed invention.

For the loading and unloading of the transport system of the honing machine in the area of a loading station of the honing machine, e.g. at least one of the following devices be provided: a gantry loader with a horizontally and vertically movable gripper arm; a loading robot; a pendulum sleigh.

BRIEF DESCRIPTION OF THE DRAWINGS

Further advantages and aspects of the invention will become apparent from the claims and from the following description of preferred embodiments of the invention, which are explained below with reference to the figures.

Fig. 1 shows an oblique perspective view of an embodiment of a honing machine with inner column;

Fig. 2 shows a plan view of the honing machine in Fig. 1;

3 shows an isometric view of an assembly with counterholder device and tool change magazine according to an embodiment; Fig. 4 shows a longitudinal section through the assembly of Fig. 3; and

Fig. 5 shows an oblique perspective view of the underside of the tool magazine of the assembly.

DETAILED DESCRIPTION OF THE EMBODIMENTS

1 shows an oblique perspective view of a honing machine 100 according to an embodiment of its loading and unloading side. Fig. 2 shows a plan view of the honing machine. The honing machine has three honing stations 160-1, 160-2, 160-3, each with two independently controllable honing units, and is adapted to rotate the cylinder bores of workpieces W in the form of cylinder crankcases in several different honing operations (eg, pre-honing, intermediate honing, and finish honing). completely edit.

The 6-spindle honing machine has a rectangular machine base 10 carrying all the mechanical components of the honing machine. The machine base in a first direction of the honing machine (corresponding to the x-direction of the machine coordinate system MKS, also referred to as longitudinal direction) has a length substantially equal to the width in the second direction orthogonal to the first direction (corresponding to the y-direction of the machine coordinate system) as width direction or transverse direction) corresponds. The width of the machine base may for example be between 1800 mm and 3000 mm. The widthwise narrow design allows transport of the completely pre-assembled machine base on conventional means of transport, for example by truck or rail vehicle.

On the machine base, a vertical column is mounted approximately centrally between the sides running in the x-direction, which is referred to here as inner column 150. The inner column 150 forms a central support structure or support structure of the honing machine and is designed accordingly stable and torsionally rigid. In the exemplary embodiment, the inner column 150 is essentially formed by a circular-cylindrical steel tube of suitable wall thickness. To achieve sufficient load bearing capacity, the diameter of the inner column is usually 500 mm or more, for example in the range of 700 mm to 800 mm. The wall thickness can be, for example, in the range of 5 mm to 20 mm. The height of the inner column measured in the vertical direction (z-direction) is a multiple of the cross-sectional dimensions and may be, for example, in the range of 800 mm to 2000 mm. The cylindrical outer side of the inner column carries in the example shown no mechanical functional units of the honing machine, in particular no processing units.

In the region of the upper end of the inner column 150, the machine upper part 120 of the honing machine is attached to the inner column, e.g. attached by means of a front flange connection. The machine head is at a vertical distance of e.g. 800 mm to 2000 mm) above the machine base and is supported exclusively by the inner column 150.

The machine head 120 of the embodiment has an approximately cuboid shape and has in the y-direction a width which is slightly larger than the diameter of the inner column 150, but less than twice this diameter. The length in the x-direction is just as large, so that the machine upper part has a substantially square cross-section (in the x-y plane) (compare FIG. 2). The inner column 150 and the machine head 120 mounted thereon form in this example a symmetrical to the central longitudinal axis of the inner column T-shaped arrangement in such a way that the center of gravity of the machine head 120 above the inner column is substantially on the central longitudinal axis.

The area between the bottom of the machine head 120 and the top of the machine base 1 10 contains the working space of the honing machine. Since the machine upper part is supported exclusively by the inner column 150 arranged at a distance from the edge of the machine base, the working space in this example is in principle accessible from all sides to an operator or control units.

The six independently controllable honing units 180-1, 180-2, 180-3, 180-4, 180-5 and 180-6 of the honing machine are carried by the machine head 120. The construction of a honing unit will be described below with reference to the honing unit 180-1.

The honing unit 180-1 comprises a headstock 182 which serves as a bearing for the honing spindle 184, which is guided with a vertical spindle axis in the headstock. The rotation of the honing spindle about the spindle axis is effected by a rotary drive. A lifting drive causes the parallel to the spindle axis vertical movements of the honing spindle during insertion of the honing tool 185 in the bore to be machined or when pulling the honing tool from this hole. The honing tool is coupled by means of a drive rod 186 double-hinged to the honing spindle. The lifting drive can be controlled during the honing process so that the honing tool within the bore of the Workpiece performs a vertical reciprocating motion according to the desired Honparameter.

The honing unit 180-1 has a feed system, which comprises two independently operable feed devices in order to be able to control honing tools with double widening if necessary. Since the structure of double widening delivery systems is known per se, a detailed description is omitted here.

The honing unit 180-1 is mounted on a horizontal slide 190 carried by the machine head 120. The horizontal carriage runs on a pair of guide rails 192 which are mounted vertically one above the other in a side surface of the machine head 120 parallel to the first direction (x-direction). The linear travel direction of the horizontal carriage of the first honing station thus extends in the longitudinal direction (x-direction) of the honing machine. The drive for the carriage movement via a horizontal slide drive with a servo motor which drives a parallel to the guide rails extending ball screw on which a spindle nut sits, which is fixed to the underside of the base plate of the horizontal slide. Other drive concepts are possible, such as rack drive or belt drive.

At the left in Fig. 1 recognizable side of the machine head two identical honing units 180-1, 180-2 are mounted side by side. These belong to the first honing station 160-1. The honing units can be moved horizontally controlled independently of each other. This can for example be achieved in that the honing units are mounted on independently movable horizontal slide. These two horizontal slides can run on the same guide rails 192. For each of the slides, a separate drive can be provided. It is also possible for a first horizontal carriage running on the guide rails to carry both honing units, one of the honing units being fixedly mounted on this horizontal carriage and this horizontal carriage carrying guide rails for a separate second horizontal carriage to which the other honing unit is fastened. As a result, the lateral spacing of the spindle axes of the two honing units carried by the first horizontal carriage can be adjusted. Another possibility is that the honing units are mounted on independently movable horizontal slide, which run on the same guide rails 192, these horizontal slides are coupled to each other with adjustable distance from each other. A first drive then serves to move the horizontal slide along the guide rails, while a second drive for numerically controllable adjustment of the spindle distance is used. At the loading and unloading side opposite back is a corresponding arrangement with two independently linearly horizontally movable honing units 180-3 and 180-4. These are movable in the y-direction (transverse direction) and belong to the second honing station 160-2.

At the first honing station diametrically opposite other longitudinal side is a corresponding arrangement with two other independently linearly horizontally movable honing units 180-5, 180-6. These are movable in the x-direction (longitudinal direction) and belong to the third honing station 160-3.

On the machine base 10, a transport system 130 in the form of a circulation transport system 130 for transporting workpieces is arranged on a transport path 132 running around the inner column 150. The circulating transport system comprises, in the example case, a rotary table which has an annular device carrier running around the inner column and can therefore also be referred to as a ring table. The rotary table is indefinitely rotatable about a coaxial with the longitudinal central axis of the inner column extending vertical rotary axis and fixed in vorgebaren rotational positions, so that it can also be referred to as a rotary indexing table.

The rotary table or the device carrier of the rotary table has a concentric with the rotary table axis or to the longitudinal center axis of the inner column lying inner ring 133, protrude horizontally from the four offset by 90 ° in the circumferential direction positions radially elongated plate-shaped support arms 134. Each support arm has on its upper side a workpiece holder 135.

The ring table 130, in addition to the rotary drive which causes the rotation about the rotary table axis, still has a lifting drive to lift the device carrier of the ring table controlled by the machine control of the honing machine in the vertical direction (z-direction, parallel to the rotary table axis) as needed or lower. The rotary table is thus designed as a lifting rotary table. It is used in the example case to carry out a workpiece transport in the manner of a round-step stroke.

At each of the workstations, ie at each of the honing stations and at the loading station, a machine-fixed workpiece support means 170 (see loading station 140) is mounted on the machine base 1 10. The four workpiece support devices have identical structure. A workpiece supporting device has two vertical, substantially plate-shaped support elements 172-1, 172-2, which are at a lateral distance from each other. The free Upper end sides of the support elements serve as support surfaces on which the workpiece W (cylinder crankcase) can be placed with its underside. The free upper surfaces of the support elements serve as second support structures for supporting the workpiece in second support areas on the underside of the workpiece, these second support areas being located at the longitudinal ends of the cylinder crankcases. The second support structures have indexing for the correct position recording of a workpiece (cylinder crankcase) on the workpiece support means. These indexing devices (index pins / index holes) are formed corresponding to indexing devices on the underside of the workpiece, so that when depositing a workpiece this passes by means of the indexing automatically with high positioning accuracy in the machining position. The workpiece can be clamped in the processing position (eg at each of the honing stations) by suitable clamping devices. In the example, is dispensed with separate clamping devices, as a later-explained counter-holding device 330 is present, which prevents lifting of the workpieces during processing.

The honing machine 100 has four work stations arranged along the circular transport path 132 of the circulating transport system. The rotary table serves as a machine-internal transfer system in such a way that a recorded in a workpiece holder of the rotary table workpiece can be transported by rotation of the rotary table successively to the different workstations of the honing machine. In the illustrated configuration of FIG. 1, the workstations disposed on the visible front of the machine base is a loading station 140 for loading and unloading the recirculating transport system 130 and the rotary table, respectively. In the example of FIG. 1, the machine upper part 120 on the side of the loading station 140 is so short that the transport path 132 is accessible from above (see FIG. 2). For loading and unloading so for example a portal gripper can be used. A loading and unloading from the front, e.g. by means of a loading robot or a pendulum carriage, is also possible.

Each of the six honing units 160-1 to 160-6 includes an assembly 300 which has a lifting carriage 310 carried by the associated horizontal slide, which can be moved in the vertical direction (z-direction) by means of an electromotive lifting carriage drive 312. The lifting carriage 310 carries a (movable by means of the lifting carriage) counter-holding device 330 and a tool magazine integrated therein 350 with a plurality of tool holders 360, which are each designed to receive a single honing tool. An embodiment of the assembly is shown in Fig. 3 in an oblique perspective, Fig. 4th shows a longitudinal section through the assembly, Fig. 5 shows an oblique perspective view of the underside of the tool magazine.

The assembly 300 includes a spacer bracket 320, which has the shape of a horizontal U with a single-sided opening and serves to rigidly connect the assembly 300 to the honing unit and / or to the horizontal slide. The distance bracket can be fastened, for example by means of screws releasably on the headstock of the honing unit and / or on the horizontal unit carrying the honing unit. In the example, the distance bracket is mounted directly below the headstock on the horizontal slide. It is also possible to realize the function of the distance bracket by a fixedly connected to the horizontal slide horizontal mounting plate or the like. This can e.g. be welded to the horizontal slide or integrally formed with this.

At the bottom of the spacer bracket a cross-sectionally U-shaped Hubkonsole 322 is attached, which has on its inside a pair of vertically extending guide rails 314 on which the guide shoes of the lifting carriage 310 are guided. The servomotor of the lift carriage drive 312 mounted in the area of the vertical axis spacer 320 drives a vertically oriented ball screw on which runs a spindle nut fixed between the guide shoes on the facing side of the lift carriage 310. As an alternative, a linear drive is also considered.

The lifting carriage 310 has at its lower end a horizontal mounting plate 316, on which the tool magazine 350 is rotatably mounted about a vertical axis of rotation. The rotation of the tool magazine is effected by means of a servomotor-equipped magazine drive 352 mounted on the vertical-axis mounting plate. The pivot bearing and the drive for the tool magazine are mounted in the region of the mounting plate 316.

The tool magazine 350 is designed as a six-fold round magazine. The six mutually identical tool holders 360 are located on a pitch circle, which extends through the extension of the spindle axis 187, so that each one of the tool holders can be brought into a centered to the spindle axis working position by rotation of the round magazine. Each of the tool holders 360 has a vertical through hole for passing a honing tool and a tool holder 365 which is convertible between a holding configuration and a release configuration. In the holding configuration, a received honing tool is held within the through hole and secured against falling. In the release configuration, the honing tool may contact the honing spindle or drive rod 186, respectively is coupled, taken up or down to the workpiece to be performed.

The tool magazine has a central carrier shaft 361, which is coupled with a vertical axis directly to the output shaft of the magazine drive 352. At the lower end of the carrier shaft 361 is mounted a solid, round base plate 362 with six through holes for passing the honing tool. At a distance above the base plate there is an annular ring 363 running around the carrier shaft, with six through holes at the locations of the tool holders. The vertical distance between base plate and middle plate is u.a. maintained over spacers. At a distance above the middle ring 363 is a device ring 366 which has six identical ring segments, one of the ring segments belonging to each tool holder. Each of the ring segments carries movably mounted components of a tong-like tool holder 365. Each workpiece holder has a locking device for securing the held honing tool in the tool holder. The locking device of the tool holder, which is located in the working position aligned with the spindle axis, can be automatically unlocked by means of a tool unlocking device 370. A pneumatic drive 372 of the tool unlocking device is mounted next to the magazine drive 352 on the lifting carriage 310 and acts via a rocker arm on unlocking the tool holder 365th

On the underside of the base plate 362, a rinsing and centering ring 380 is mounted for each tool holder, which carries on its side facing the workpiece an interchangeable, workpiece-dependent pressure ring 385. The supply of flushing rings with cooling lubricant takes place in sections via U-shaped downwardly hanging flexible coolant hoses 382, which compensate for the up and down movement of the vertically movable assembly 300. In the region between the base plate 362 and the middle ring 363, a sleeve-shaped reference ring 390 is mounted for each tool holder, which has a cylindrical inner contour with exactly known inner diameter and serves as a reference element for an in-tool dimensional measuring system.

The honing machine 100 can be used as follows, for example. An unprocessed workpiece (cylinder crankcase) is loaded into the honing machine in a loading operation. Here, the hub rotary table 130 is in its lowering position and the workpiece support means on the charging station 140 is free. The workpiece can, for example, by a lying next to the machine head 120 window 142 in the Machine paneling above the loading station lowered by a gantry loader on the workpiece support means or loaded from the front, by a dashed lines in Fig. 1 drawn door in the horizontal direction.

Subsequently, the workpiece is transported in a Rundschritthub operation to the first honing station 160-1. This operation involves raising the rotary table 130 upwardly so that the workpiece is lifted off the workpiece support by the support arm, indexing the rotary table 90 ° clockwise until the cylinder crankcase above the workpiece support means of the first honing station 160-1 is arranged, and lowering the Hub-round table down, wherein the workpiece is deposited on the workpiece support means of the first honing station. The workpiece is then in its machining position. The mutually aligned cylinder bores are then arranged so that all cylinder axes lie in a common tangent plane to a reference circle which is concentric with the axis of rotation of the rotary table. The spindle axes of the two honing units 180-1, 180-2 of the first honing station 160-1 are also in this tangential plane and can be moved within this tangential plane by moving the horizontal carriage 190 in the x-direction, so that with a honing spindle different cylinder bores for machining can be approached.

First, two cylinder bores are simultaneously processed in parallel by means of the two honing units 180-1, 180-2. For this, the honing units are positioned vertically above these cylinder bores. Then, the assemblies of the counter-holder 330 are lowered with integrated tool magazines by moving the respective lifting down in the direction of the workpiece until the pressure pieces meet at the lower end of this unit on the workpiece top. Thereby, the workpiece is secured by means of the counter-holder device 330 against lifting of the workpiece support device during honing.

Then the honing is done by the honing tools are introduced into the holes to be machined and then perform the honing operation. The insertion process is supported by the centering and flushing rings attached to the rotary table of the tool magazine. The centering and flushing rings also support the supply of cooling lubricant into the holes during machining.

After completion of the processing of the first pair of cylinder bores, the assemblies with tool magazine and counterholder direction and the honing spindles are raised independently of each other but coordinated in time, so that the Honing tools are pulled out of the cylinder bores. The horizontal slide is then moved in the x-direction so that the two honing spindles now lie over the next two cylinder bores to be machined before they are machined. For editing, the lifting carriage is then lowered again in order to make the workpiece free of play in the vertical direction before the honing tools are introduced into the cylinder bores. Upon completion of this honing operation, the honing process at the first honing station is completed. The workpiece is released by moving up the counter-holder with integrated tool magazines and can now be lifted by lifting the rotary table of the workpiece support means.

For further transport to the second honing station 160-2, the lifting rotary table is raised, indexed by 90 ° in the clockwise direction and then lowered again, so that the workpiece is seated on the workpiece support device of the second honing station 160-2. The honing operation in the second honing station 160-2 is then carried out analogously, as is the further transport to the third honing station 160-3 and the honing operation there. After completion of honing at the third honing station 160-3, the now finished workpiece is transported back by 90 ° to the loading station 140 by lifting the rotary table and advancing, from where it is then removed.

The honing machine thus allows the parallel processing of two cylinder bores at each honing station. Through the combination of a total of six honing units at three sequentially approachable honing stations a sequence of pre-honing, intermediate honing and finishing honing in a relatively short processing time is possible.

If a tool change is to be carried out, for example when a honing tool is worn or when converting to another type of workpiece or another honing operation, a tool change can be carried out either automatically or manually in a simple manner. For this purpose, the tool magazines traveling along with the honing units can be equipped with up to six optionally exchangeable honing tools. For a tool change, the honing tool to be exchanged coupled to the drive rod is first of all positioned by vertical movement of the honing spindle so that the honing tool can be gripped and held by means of the tool holder device 365. Then the tool release is actuated, and the connection between the drive rod and honing tool is achieved by turning the drive rod relative to the honing tool. Subsequently, by turning the tool magazine, that tool holder which carries the honing tool to be inserted is brought into the working position aligned with the honing spindle. The coupling to the drive rod then takes place also automatically, after completion of the coupling the honing tool is released by the tool holder device and can then be used.

It should be noted that the function of the tool change is possible without moving the tool magazine vertically. However, the integration of the tool magazine and the counter-holding device on the vertically movable lifting slide means that a tool magazine with a relatively small diameter can be used, so that the tool change function of the 6-fold changer can be integrated with compact dimensions in the lateral direction into the horizontally movable assembly.

Since the tool change function is integrated in the horizontally movable assemblies, external tool changers can be dispensed with. As a result, the honing units in the horizontal direction only have to be movable so far that all bores with a honing spindle or a honing unit can be achieved in all workpiece types to be machined. In the exemplary embodiment shown, the required travel paths in the horizontal direction are less than 500 mm for all three honing stations. It can thereby be achieved that, despite the provision of two honing units each on three sides of the machine upper part, a honing machine with very compact external dimensions (typically less than 3 m in the x-direction and y-direction) can be realized.

Claims

claims

1 . Honing machine (100) for performing honing operations on at least one bore in a workpiece (W), in particular for honing cylinder bores in a cylinder crankcase, comprising:

a machine base (110);

a support structure associated with the machine base;

a machine shell (120) carried by the support structure spaced above the machine base;

a transport system (130) for transporting workpieces (W) on a transport path (132);

a plurality of work stations (140, 160-1, 160-2, 160-3) arranged along the transport path, wherein a workpiece can be transported successively to different workstations of the honing machine by advancing the transport system,

wherein at least one of the work stations is an honing station (160-1, 160-2, 160-3), the honing station has at least one horizontal slide (190) extending from the

Machine head (120) is carried and is movable in a horizontal direction, and the horizontal slide at least one honing unit (180-1, 180-2, 180-3, 180-4, 180-5, 180-6) carries a honing spindle ( 184) which is rotatable about a vertical spindle axis (187) and movable parallel to the spindle axis,

characterized in that

the horizontal carriage (190) carries a lifting carriage (310) which is movable in a vertical direction,

wherein the lifting carriage carries a counterhold device (330) and a tool magazine (350) with a plurality of tool holders (360) for receiving a respective honing tool.

2. honing machine according to claim 1, characterized in that the tool magazine (350) is designed as a round magazine.

3. Honing machine according to claim 2, characterized in that the circular magazine has an annular arrangement with four to twelve tool holders (360), in particular with six or eight tool holders.

4. honing machine according to claim 2 or 3, characterized in that some or all tool holders (360) of the round magazine lie on a pitch circle, which extends through the extension of the spindle axis (187).

5. honing machine according to one of the preceding claims, characterized in that each of the tool holders (360) has a vertical through hole (361) for passing a honing tool and a tool holder (365) for holding a honing tool in the through hole, wherein the tool Holding device between a holding configuration and a release configuration is umstellbar.

6. Honing machine according to one of the preceding claims, characterized in that each of the tool holders (360) is assigned to a workpiece side end of at least one pressure element (385) for placement on an upper side of the workpiece.

7. Honing machine according to one of the preceding claims, characterized in that each of the tool holders (360) is associated with at least one of the following means:

a centering device for centering the honing tool for insertion into a bore to be machined;

a flushing ring to aid in the supply of cooling lubricant into the bore;

a reference ring (390) for referencing a bore measuring system of the honing tool.

8. Honing machine according to one of the preceding claims, characterized in that the horizontal slide (190) is attached to a side surface of the machine head.

9. Honing machine according to one of the preceding claims, characterized in that the transport system is designed as a circulation transport system (130) for transporting workpieces (W) on a revolving transport path (132), wherein the circulating transport path is preferably closed in the circumferential direction.

10. honing machine according to claim 9, characterized in that the support structure has an inner column (150) and the circulating transport system (130) for transporting workpieces (W) on a running around the inner column transport path (132) is formed.

1 1. Honing machine according to one of claims 9 or 10, characterized in that the circulating transport system comprises a rotary table (130) which is rotatable about a vertical rotary table axis and a plurality of workpiece holders (135) which are offset from one another with radial distance to the rotary table axis in the circumferential direction arranged that a workpiece received in a workpiece holder by rotation of the rotary table successively to different workstations (140, 160-1, 160-2, 160-3) of the honing machine is transportable.

12. Honing machine according to claim 1 1, characterized in that the rotary table (530) by means of a lifting drive vertically between a lower position and an upper position is movable, so that the rotary table is designed as a lifting rotary table.

13. honing machine according to one of claims 9 to 12, characterized in that at each of the work stations, a stationary workpiece support means (170) is provided for receiving a workpiece in a processing position, wherein the workpiece support means in such a way to the region of the workpiece holder of the rotary table (130) is adapted that a recorded in a workpiece holder of the rotary table workpiece by lowering the rotary table in the direction of the lower position of the workpiece holder of the rotary table transferred to the workpiece support means and by raising the rotary table in the upper position from the processing position on the Workpiece support device is transferable into the workpiece holder of the rotary table.

14. Honing machine according to one of the preceding claims, characterized in that the honing machine (100) has at least three workstations, which are formed as honing station (160-1, 160-2, 160-3), wherein preferably the honing machine exactly three honing stations ( 160-1, 160-2, 160-3).

15. honing machine according to claim 14, characterized in that a first honing station (160-1) on a first side, a third honing station (160-3) on one of the first side diametrically opposite third side and a second honing station (160-2 ) is arranged on the transport path between the first and the third honing station on a second side.

16. Honing machine according to one of the preceding claims, characterized in that at least one honing station (160-1, 160-2) has two or more honing units, which can work at the same time, preferably exactly three honing stations (160-1, 160-2) are provided with exactly two honing units.