Honing machine

Abstract

Honing machine (100) for machining workpieces which have at least one bore to be machined by honing, comprising: several workstations (180-1, 180-2), wherein at least one of the workstations (180-1, 180-2) is configured as a honing station (180-1, 180-2) comprising at least one honing unit (150-1, 150-2) which has a spindle shaft (152) rotatable about a vertical spindle axis (155) by means of a rotary drive and movable back and forth parallel to the spindle axis (155) by means of a lifting drive; and a machine-internal pallet transport system (200) for transporting workpieces to and from the workstations (180-1, 180-2) using pallets (210-1, 210-2), wherein the pallet transport system (200) is designed such that different transport routes can be freely configured via a control unit (190) of the honing machine (100), characterized in that the pallet transport system (200) has four bidirectionally usable linear transport sections (202-1 - 202-4) arranged in a rectangular arrangement, wherein transfer positions (204-1 - 204-4) for transferring pallets (210-1, 210-2) between mutually orthogonal adjacent transport sections (202-1 – 202-4) are arranged in corner areas of the rectangular arrangement.

Description

[0001] The invention relates to a honing machine according to the preamble of claim 1 for machining workpieces which have at least one bore to be machined by honing.

[0002] Honing is a machining process with geometrically undefined cutting edges. In this process, a honing tool performs a two-component cutting motion, maintaining constant surface contact between one or more cutting material elements (e.g., honing stones) of the honing tool and the bore's inner surface being machined. The kinematics of a honing tool are characterized by a superposition of a rotary motion and a stroke motion in the axial direction of the bore, which in most honing processes is an oscillating back-and-forth movement. In many applications, a reaming motion is also incorporated, resulting in a change in the effective diameter of the honing tool.

[0003] On the inner surface of the bore, the kinematics of the honing tool create a surface structure with intersecting machining marks. Surfaces finished by honing can meet extremely high requirements regarding dimensional and form tolerances, and in some cases exhibit a special surface roughness and structure that combines low wear due to a high material bearing area with the ability to maintain an oil film for lubrication. Therefore, many highly stressed sliding surfaces in engines or engine components, as well as the inner surfaces of bores in hydraulic blocks or injection pump housings, are finished by honing.

[0004] In many cases, machining the inner surfaces of bores involves several different, successive honing operations, such as pre-honing to create the required basic shape and finish honing to produce the final desired surface structure. The success of the machining process can be verified through measurement steps.

[0005] In this application, the term "honing machine" refers to a numerically controlled machine tool capable of performing at least one honing operation on a workpiece, thus making the machine tool suitable for honing. The honing operation is performed at a honing station. A honing station is a workstation comprising at least one honing unit. A honing unit of the type considered here has a spindle shaft that can be rotated about a vertical spindle axis by means of a rotary drive and moved back and forth parallel to the spindle axis by means of a linear drive. The spindle shaft has a device for attaching a honing tool at one end, on the tool side. The honing machine can be designed as a pure honing machine, in which all workstations (machining stations) set up for workpiece machining are designed as honing stations.If necessary, the honing machine can also be used to perform other machining operations on a workpiece, typically involving material removal, such as one or more drilling operations, deburring, and / or brushing. Appropriate workstations (machining stations) can be provided for this purpose. At least one measuring station may also be integrated.

[0006] Since a honing machine of this type comprises several spatially separated workstations, an internal transport system is provided for moving workpieces to and from these workstations. This system is configured as a pallet transport system, where workpieces are transported to and from the workstations using pallets. Chapter 15.3 of the textbook "Fundamentals and Applications of Honing" (Fundamentals and Applications of Honing), Essen: Vulkan-Verlag, 1992, describes a machine concept for a honing machine of this type. To implement the honing of a V8 block in series production, a transfer honing machine with three honing stations, one measuring station, and a pallet circulation system was designed. The cylinder bore is honed at the first two honing stations. The third honing station is used for machining the main bearing bore.From a loading and unloading station, where the blocks are mounted on carrier pallets, the workpieces are transported via suitable conveyor systems to the machine's machining line. At the honing and measuring stations, NC tables with integrated swivel devices are located, which move the respective bore of a block into the desired machining position by swiveling and moving it in the X and Y directions.

[0007] German patent application DE 10 2004 053 503 A1 discloses a honing system for honing workpieces. The honing system comprises a plurality of workstations, each configured to perform at least one operation on a workpiece, and at least one part of each workstation is set up as a honing station for performing at least one honing operation on a workpiece. The honing system also includes a conveyor system for transporting workpieces to and from the workstations. Furthermore, a control unit for controlling the honing system is provided. Each workstation is directly connected to the conveyor system. This configuration allows for flexible control of the honing process.

[0008] German patent application DE 10 2012 201 730 A1 discloses 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. The honing machine has a machine base, several vertical columns arranged in the periphery of the machine base, a machine upper section supported by the columns and arranged at a distance above the machine base, and a rotary table arranged on the machine base, which is rotatable about a vertical rotary table axis and has several workpiece holders that are arranged radially offset from each other in the circumferential direction such that a workpiece held in a workpiece holder can be successively transported to different workstations of the honing machine by rotating the rotary table.At least one of the workstations is a honing station, which has at least one honing unit supported by the upper part of the machine, which has a honing spindle that is rotatable about a vertical spindle axis and can be moved back and forth parallel to the spindle axis.

[0009] Utility model DE 20 2015 009 036 U1 discloses a honing machine comprising a stand with at least two feet, wherein the stand has an area with two substantially parallel surfaces and wherein at least one honing spindle, another machining spindle or another functional unit is arranged on the two surfaces of the stand. TASK AND SOLUTION

[0010] It is an object of the invention to provide a honing machine of the generic type, which is characterized by high flexibility in use and a potential for high output.

[0011] To solve this problem, the invention provides a honing machine with the features of claim 1. Advantageous embodiments are specified in the dependent claims. The wording of all claims is made clear by reference to the content of the description.

[0012] The honing machine is designed for machining workpieces that have at least one bore requiring honing. The honing machine has multiple workstations; for example, it can have two, three, or four workstations arranged at different distances from each other. At least one operation is performed on the workpiece at each workstation. Workstations where the workpiece's properties are modified, for example, through machining, are also called machining stations. A measuring station is an example of a workstation where no machining operation that modifies the workpiece is performed.

[0013] At least one of the workstations is configured as a honing station. Within the scope of this application, this means that the workstation comprises at least one honing unit having a spindle shaft which can be rotated about a spindle axis by means of a rotary drive and moved back and forth parallel to the spindle axis by means of a linear drive. The spindle axis is vertically oriented.

[0014] The machine's internal transport system for moving workpieces to and from the workstations is designed as a pallet transport system that operates using pallets. The term "pallet" here refers to an interchangeable workpiece carrier to which one or more workpiece holding devices are attached or can be mounted to hold a workpiece in a desired position on the pallet. Optionally, a workpiece holding device can also include a rotary mechanism to rotate a held workpiece around at least one axis of rotation, thereby changing its orientation relative to the pallet.

[0015] According to one formulation of the invention, the pallet transport system is designed such that different transport paths can be freely configured via a control unit of the honing machine. "Freely configurable" in this context means that a transport path can be selected and used from a finite number of structurally and control-technically possible transport paths. "Free" therefore does not mean "arbitrary." This makes it possible, among other things, to transport workpieces from a loading position to one or more workstations and from these stations again via different, pre-selected transport paths, particularly back to the same loading position. If several workstations are to be used, they can be operated in different sequences or simultaneously.In this context, the term "operate" means that a pallet can be transported to or from a workstation using the pallet transport system.

[0016] The timing of workstation operation can be selected via the control system. It is also possible to operate different workstations on different transport routes from a single loading position. If required, loading and unloading can be performed at various positions along the transport routes. This differs from conventional pallet circulation transport systems, where the design of the transport system dictates a specific sequence of workstations to be visited sequentially during a cycle. The variable usability of the workpiece transport system allows for a high degree of flexibility in the operation of the honing machine. Furthermore, it offers the potential for high output, partly because multiple operations can be performed independently and simultaneously in phases. Loading and unloading in parallel with the cycle time is also possible.

[0017] According to the invention, the pallet transport system has four bidirectionally usable linear transport tracks arranged in a rectangular configuration. Transfer positions for transferring pallets between mutually orthogonal adjacent transport tracks are located in the corner regions of the rectangular configuration. A pallet can be transported in a straight line in either of two opposite directions along a bidirectionally usable linear transport track. This allows for numerous combinations of transport tracks and, consequently, numerous different transport routes to be configured, which may consist of two or more linear transport tracks. It is also possible to use a single transport track in both directions for transport to and from a workstation.

[0018] The pallet transport system preferably has several (e.g., four) bidirectional linear transport sections, each of which has a single horizontally movable pallet carrier. Transfer positions for transferring pallets between adjacent transport sections are arranged between these sections, and the pallet carriers of adjacent transport sections are designed for the direct transfer of pallets without an additional transfer device. Therefore, no separate aids for transferring or moving pallets are required at the transfer positions. The pallet carriers can be adapted to each other so that they can partially slide into one another, with one of the pallet carriers interacting in the transfer position capable of performing lifting or lowering operations.

[0019] The honing machine can be designed to offer various loading and unloading options. For example, a pallet can be loaded or unloaded at a transfer position. In one embodiment, the pallet transport system has a loading and unloading station (or simply loading station) located on the operator side of the honing machine between the ends of a bidirectional linear transport track. The loading and unloading station can, for example, be situated midway between the ends of the transport track, which runs from one transfer position to another on the operator side. This loading station can be used as a distribution station during loading, as onward transport can occur in two different directions. Accordingly, pallets can also be transported to the loading station from two opposite directions. This increases the flexibility of the honing machine when handling workpieces. A loading operation (e.g.,Loading a pallet held on a pallet carrier, removing finished workpieces, installing or removing a pallet that may already be loaded, or similar tasks) can be carried out manually, semi-automatically, or fully automatically, depending on requirements.

[0020] According to a further development of the variant with a rectangular arrangement of transport tracks, at least one honing station is positioned in a corner of the rectangular arrangement at a transfer position such that pallets can be transported in and out in two mutually orthogonal directions. Such a honing station can thus be loaded and unloaded from two directions that are at an angle to each other. A pallet can be transported in one direction and then removed along the same transport track in the opposite direction. It is also possible to transport the pallet in along one transport track and, after using the workstation, to remove it along the other transport track that is at an angle to it.

[0021] It is possible, in principle, for the honing machine to have only a single honing station. However, in some designs, a significant contribution to increased flexibility and output is achieved by having a first honing station and a second, independently usable honing station, with the honing stations arranged in transfer positions at opposite ends of a linear transport track. This allows for multi-spindle honing to be performed in a compact installation space, either simultaneously at both honing stations and on different workpieces, or sequentially on the same workpiece or on different workpieces.

[0022] Preferably, exactly two honing stations are provided, each preferably with only a single honing unit. This achieves a good compromise between design complexity and flexible usability.

[0023] In some embodiments, the honing unit of at least one honing station is arranged on a horizontal slide that can be moved horizontally parallel to a first direction.

[0024] This provides a horizontal machine axis that enables controlled, precisely controllable movement and positioning of the honing unit in a horizontal direction by means of an NC drive. Thus, the spindle axis can be moved to different positions relative to a potentially stationary workpiece by moving this horizontal slide in the first direction.

[0025] In one embodiment of the honing machine with a first honing station and a second honing station that can be used independently, the two honing units are preferably each arranged on such a horizontal slide, and the horizontal slides can be controlled independently of each other. The horizontal slides can run on the same guide rails, which simplifies the design.

[0026] In some configurations, it may suffice for the horizontal slide to carry only a honing unit and no other machining or working unit. Additional flexibility regarding the types of different machining operations can be achieved in some embodiments by having the horizontal slide carry at least one additional working unit besides the honing unit. This additional working unit can also be moved horizontally and positioned in different locations. For example, this additional working unit could be a deburring unit, which can carry a deburring tool that can also be positioned by moving the horizontal slide in the first direction. Alternatively or additionally, it is also possible to provide another working unit in the form of a measuring unit, which, for example, has a measuring head that can be recessed into a bore.The horizontal slide can also be used to position the measuring head in the first direction.

[0027] Some embodiments are characterized by the fact that the pallet transport system has at least one pallet carrier that can be moved horizontally in at least one horizontal direction and additionally vertically, i.e., parallel to the spindle axis of a honing unit, in two opposite directions, i.e., bidirectionally. If the horizontal transport path usable by the pallet carrier leads to and from a workstation, the pallet transport system can simultaneously function as a part positioning system within the workstation area, in order to position a bore to be machined precisely in a desired position with respect to the spindle axis of a honing unit (or another axis-operated work unit).

[0028] The controlled vertical movement can be used, for example, to bypass component defects and / or to ensure that components of different heights with the same or similar component geometry can be processed in the same way.

[0029] It is possible to design the structure so that the pallet carrier can move bidirectionally in two mutually perpendicular horizontal directions as well as in the vertical direction. This would allow all degrees of freedom for positioning a pallet or a bore of a workpiece it carries to be realized in a Cartesian coordinate system on the workpiece side.

[0030] In embodiments that feature a horizontal slide at a workstation, movable bidirectionally parallel to the first direction and carrying a honing unit and / or another working unit, a single horizontal machine axis on the pallet carrier side may suffice to realize all positioning degrees of freedom. This allows for a simplified design.

[0031] Some embodiments are characterized by the fact that the pallet transport system has at least one pallet carrier that can be moved horizontally parallel to a second direction perpendicular to the first direction and additionally vertically parallel to a third direction parallel to the spindle axis in two opposite directions, i.e., bidirectionally. This also allows the pallet transport system to function simultaneously as a component of a part positioning system within a workstation, enabling the precise positioning of a bore to be machined in a desired position relative to the spindle axis of a honing unit (or another axis-operated machining unit). With the aid of a horizontally and vertically movable pallet carrier, workpiece positioning is possible through workpiece movements parallel to the second and third directions.A relative movement to a working unit in the first direction perpendicular to these two directions can be achieved by appropriately using the horizontal slide, which carries a honing unit and / or another working unit.

[0032] Preferably, such a horizontally and vertically movable pallet carrier is provided for each workstation, in particular for each honing station.

[0033] To achieve high positioning accuracy of the workpiece relative to the work unit (one or more) of a workstation, some embodiments provide that the (horizontally and vertically movable) pallet carrier has components of a zero-point clamping system on its upper surface, which is designed to hold a pallet. For example, clamping bushings could be attached to the upper surface, which can be actuated, for example, hydraulically or pneumatically and which interact with corresponding clamping pins on the underside of the pallets. Using the zero-point clamping system, a reference can be established between the machine coordinate system and the pallet coordinate system, and thus also with the workpiece coordinate system, so that the workpiece can be positioned reliably and with repeatable accuracy relative to a work unit using the honing machine's control system.

[0034] Preferably, the pallets have positioning aids to assist in positioning a pallet in a target position on the pallet carrier. These positioning aids can include, for example, clamping pins used within the zero-point clamping system.

[0035] A pallet can be designed as a passive component without sensors or actuators. However, in many cases, pallets are intended to be used that have one or more controllable components and corresponding actuators (one or more) and sensors (one or more) (active pallets). With appropriate control from the honing machine's control unit, this makes it possible, for example, to generate workpiece movements relative to the pallet using the controllable components of a workpiece holding device mounted on the pallet, and to provide feedback to the control unit via sensor signals about the set position and / or orientation. For example, a workpiece holding device can have a controllable rotary or swiveling mechanism for setting different rotational positions of the workpiece.

[0036] To fully utilize the potential of active pallets, some embodiments of the pallet transport system include at least one horizontally and vertically movable pallet carrier, which features automatically connectable interface components for transmitting energy and / or signals between the honing machine and a pallet supported by the pallet carrier. For example, an automatically formed and detachable fluid connection to, for instance, a pneumatic actuator of the pallet may be provided. Corresponding electrical contact elements on the pallet carrier and pallet may be provided for signal transmission, or optionally, a contactless transmission system.

[0037] One aspect of the invention can therefore also be formulated as follows: a honing machine is provided with a pallet transport system, in which the pallet transport system is a functional component of a workpiece positioning system integrated into the honing machine, which is configured to position a workpiece with a known position in the area of ​​a workstation in at least one horizontal direction as well as a vertical direction. BRIEF DESCRIPTION OF THE DRAWINGS

[0038] 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. Figure 1 shows an oblique perspective view of components of a honing machine according to an embodiment from its operator side; Fig. 2 shows a top view of the honing machine from Fig. 1; Fig. Figure 3 shows a side view of a vertical section through the honing machine. Fig. 1 and Fig. 2. DETAILED DESCRIPTION OF THE EXECUTION EXAMPLES

[0039] Fig. Figure 1 shows an oblique perspective view of components of a honing machine 100 according to an embodiment from its operator side, which also serves as the loading and unloading side. Fig. 2 shows a top view and Fig. Figure 3 shows a side view of a vertical section of the honing machine. The cladding parts present on the fully assembled honing machine are not shown.

[0040] The honing machine 100 is a computer numerically controlled machine tool whose controllable components are controlled via a central control unit 190.

[0041] The honing machine has a rectangular base 110 mm that supports all of its mechanical components. In a first direction – corresponding to the x-direction of the machine coordinate system (MCS) – the base has a width that is greater than its length in a second direction perpendicular to the first, corresponding to the y-direction of the MCS. The first direction is also referred to here as the transverse direction, and the second direction as the longitudinal direction. These dimensions in the longitudinal and transverse directions allow the fully pre-assembled base to be transported by standard means of transport, such as trucks or rail vehicles.

[0042] Side walls 120-1 and 120-2 are mounted along both longitudinal sides of the machine base. These support a torsionally rigid crossbeam 122 on the rear of the machine base 110, which forms part of the rear wall. The side walls and the rear wall enclose the working area 115 of the honing machine, which is accessible from the operator side.

[0043] On the front side of the crossbeam 122 facing the work area, two horizontal guide rails 130 are attached one above the other, extending essentially over the entire free front side of the crossbeam to the area of ​​the rear corners of the work area.

[0044] Two horizontal slides 135-1, 135-2 are arranged on the guide rails. Each slide can be moved horizontally and precisely positioned independently of the other, parallel to the first direction (x-direction), by means of numerically controlled drives. In the configuration shown, each horizontal slide carries a honing unit (first honing unit 150-1 or second honing unit 150-2), a deburring unit 160-1 or 160-2, and a measuring unit 170-1 or 170-2 on the front of a slide plate 136-1, 136-2. These working units are arranged axially parallel to the honing unit. Other configurations, e.g., without a measuring unit and / or without a deburring unit, are possible.

[0045] Each of the honing units 150-1, 150-2 has a spindle shaft 152 which can be rotated about a vertical spindle axis 155 by means of a rotary drive and moved back and forth parallel to the spindle axis by means of a lifting drive. Fig.Figure 3 shows some details. In the exemplary embodiment, a honing unit 150 comprises an elongated base support 151 that can be fixedly mounted to the horizontal slide 135-2 and can be mounted directly to the front of the horizontal slide 135-2. Furthermore, a spindle unit 158, supported by the base support, is provided in which the spindle shaft 152 is rotatably mounted. The spindle shaft is rotatable about its vertical spindle axis 155 (rotation axis of the spindle shaft) by means of a rotary drive (also referred to as a spindle motor) integrated into the spindle unit. The spindle shaft has a device at one end, on the tool side, for attaching a honing tool (not shown). The honing tool can be attached to the spindle shaft directly or indirectly by means of a connecting rod or other intermediate device.A linear guide system is arranged between the base support 151 and the spindle unit 158 ​​to guide a linear vertical stroke of the spindle unit 158 ​​relative to the base support 151. In this example, the spindle unit is mounted on a slide. A stroke drive is provided to generate the stroke movement of the spindle unit. In this example, the stroke drive comprises an electric linear motor with a primary and a secondary part, which are movable relative to each other parallel to the longitudinal direction of the linear guide system (essentially parallel to the spindle axis 155). In this example, the electrically powered primary part is located on the side of the slide or the electrically powered spindle unit 158, while a series of permanent magnets is arranged inside the base support 151. A reverse arrangement is also possible. In this example, an expansion drive is also provided for expanding the honing tool.The expansion drive can, for example, be coupled to an adjustment rod running inside the spindle shaft. The expansion drive is located in the upper part of the housing, which also contains the spindle motor.

[0046] In each of the rear corner areas of the workspace 115, a workstation of the honing machine 100 is thus formed: a first workstation 180-1 at the rear left and a second workstation 180-2 at the rear right. Both workstations are designed as honing stations, since honing operations can be carried out on suitably positioned workpieces using the independently operable honing units 150-1 and 150-2. Because the horizontal slides 135-1 and 135-2 each also carry a measuring unit and a deburring unit, the workstations can, with appropriate control, also be used as deburring stations and / or measuring stations.

[0047] The honing machine features an internal pallet transport system 200, designed for transporting workpieces to and from workstations 180-1 and 180-2 using pallets 210-1 and 210-2. The term "pallet" here refers to interchangeable workpiece carriers, which in this example consist of a solid steel plate to which further functional components (e.g., positioning aids, workpiece clamping devices) are attached. All mechanical components of the pallet transport system 200 are supported directly or indirectly by the machine base 110. The pallet transport system 200 is designed and controlled in such a way that different transport routes can be freely configured via the honing machine's control unit.

[0048] In the exemplary embodiment, the pallet transport system 200 comprises exactly four linear or straight transport sections 202-1 to 202-4, each of which can be used bidirectionally, i.e., in two opposite directions. The transport sections run horizontally and are arranged in a rectangular configuration. A first transport section 202-1 runs along the left side of the workspace 115 between the operator side and the first workstation 180-1. A second transport section 202-2 runs along the opposite right side of the workspace 115 between the operator side and the second workstation 180-2. These two transport sections 202-1 and 202-2 each run parallel to the second direction (y-direction or longitudinal direction) near the facing inner surfaces of the side walls.The two other transport routes, namely a third transport route 202-3 and a fourth transport route 202-4, run perpendicular to it, i.e. in the first direction or transverse direction, with the third transport route 202-3 running near the front (operator side) and the fourth transport route 202-4 running near the rear approximately below the crossbeam 122 and connecting the two workstations 180-1 and 180-2.

[0049] In the corner areas of the rectangular arrangement, transfer positions 204-1 to 204-4 are provided at each point where orthogonally adjacent transport routes virtually intersect. These positions facilitate the direct transfer of pallets between orthogonally adjacent transport routes. As will be explained later, each transport route has a single horizontally movable pallet carrier 260-1 to 260-4. Transfer positions 204-1 to 204-4 are arranged between adjacent transport routes for transferring pallets between these routes. The pallet carriers of adjacent transport routes are designed for the direct transfer of pallets without the need for additional transfer equipment, so that no separate aids for transferring or moving the pallets are required at the transfer positions.

[0050] At the first transfer position 204-1, located on the operator side in front of the first workstation 180-1, a pallet can be transferred directly from the third transport track 202-3 to the first transport track 202-1 or vice versa. The second transfer position is located in the area of ​​the first workstation 180-1. Accordingly, at the second transfer position 204-2, a pallet can be transferred directly in both directions between the first transport track 202-1 and the fourth transport track 202-4. The same applies to the third and fourth transfer positions on the opposite long side.

[0051] It can be seen that this means that each of the workstations, i.e. both the first workstation 180-1 and the second workstation 180-2, is arranged in a corner area of ​​the rectangular arrangement of the transport routes of the pallet transport system in the area of ​​a transfer position in such a way that the transport of pallets to and from the site is possible in two mutually orthogonal directions.

[0052] For example, the first workstation 180-1, located at the rear left, can be served by both the first transport track 202-1 and the fourth transport track 202-4. Thus, a pallet with a workpiece on it can be transported from the first transfer position 204-1 parallel to the longitudinal direction to the first workstation 180-1 and then transported back to the first transfer position 204-1 in the opposite direction. The same would also be possible along the fourth transport track. It is also possible to transport a pallet with at least one workpiece along the first transport track 202-1 from the first transfer position 204-1 to the first workstation 180-1 and, after processing, transport it at a right angle to the first workstation 180-1 using the fourth transport track 202-4 towards the second workstation 180-2.

[0053] In the exemplary embodiment, these functionalities are implemented as follows. To realize the first transport section 202-1, two horizontal guide rails 230-1 are attached one above the other, vertically spaced apart, to the inside of the first side wall 220-1 shown on the left. A horizontal slide 240-1 runs on these guide rails and can be moved horizontally with high positional accuracy in any direction parallel to the second direction (longitudinal direction) by means of a numerically controlled drive. The horizontal slide 240-1 carries two vertically extending (in the z-direction) guide rails 250-1 on its side facing the working area 115. These guide rails support a vertically movable slide 260-1, which can be moved in both directions in the vertical direction, i.e., parallel to the spindle axis 155 of the honing unit, by means of a suitable numerically controlled drive.

[0054] The carriage 260-1, which functions as a lifting carriage, serves as a pallet carrier for the first transport line 202-1 and is therefore also referred to as the first pallet carrier 260-1.

[0055] In the configuration shown, the pallet 210-1 rests on the first pallet carrier 260-1 and can support at least one workpiece clamping device with at least one workpiece during operation. A correspondingly constructed lifting carriage or a second pallet carrier 260-2 without a pallet on it is shown on the opposite longitudinal side.

[0056] On the second pallet carrier 260-2, it is clearly visible that the pallet carrier has two parallel support elements 261, designed in the manner of angle brackets, between which a gap 262 exists. Two components of a zero-point clamping system 265 are located on the horizontal upper surfaces of each support element. The four components of the zero-point clamping system 265 attached to the pallet carrier are arranged in a rectangular, specifically a square, configuration on the upper surface of the pallet carrier and allow for positioning of a supported pallet with very low tolerances. In the configuration shown, the zero-point clamping system has the clamping bushings shown, which are attached to the upper surface of the pallet carrier and interact with clamping pins on the underside of the pallets. These bushings can be actuated hydraulically or pneumatically.This enables positioning accuracies of less than one hundredth of a millimeter with high repeatability. The first pallet carrier 260-1 has a similar design.

[0057] The position of a workpiece-carrying pallet on the first or second pallet carrier can therefore be precisely specified and is known to the control unit of the honing machine if the workpiece-carrying device is mounted on the pallet at the designated reference points and the pallet is clamped in the zero-point clamping system.

[0058] Together with the high-precision NC drives for the horizontal and vertical movements of the first (or second) pallet carrier, a high-precision workpiece positioning system is created, capable of positioning a workpiece with a known position within a workstation in both the longitudinal (y-direction, second direction) and vertical (z-direction) directions. Combined with the precisely controlled horizontal movement of the horizontal slide, which carries one or more machining units (e.g., a honing unit) of the workstation, this enables exact positioning of the workpiece relative to a tool used at the workstation in all three spatial directions (x-, y-, and z-directions).

[0059] Even with the components described so far, the honing machine can be used for the precise machining of bores by honing and / or deburring. For example, the first pallet carrier 260-1 can initially be moved to the position shown near the operator side. A pallet 210-1 with a workpiece holding device (not shown) and a workpiece clamped in it is then placed on the pallet carrier. A single workpiece can be placed on it at once. It is also possible to place several workpieces simultaneously. The first pallet carrier 260-1 is then moved along the first transport track 202-1 to the rear, to the first workstation 180-1. There, the spindle axis 155 of the honing unit is positioned coaxially with the bore axis of the first bore to be machined.Any necessary relative movement in the x-direction (first direction) is achieved by horizontal movement of the honing unit. Any positioning movements in the second direction (y-direction) and in the vertical direction (z-direction) are achieved by corresponding movements of the first pallet carrier 260-1. Once the bore is positioned at the correct height and aligned with the spindle axis, the honing process can be carried out in a conventional manner. A corresponding or entirely different workpiece machining operation could be performed independently at the second honing station, which is essentially constructed in the same way and is operated by the second pallet carrier 260-1, which can be moved horizontally and vertically.

[0060] The two workstations 180-1 and 180-2, located in the rear corners of the work area 115 of the honing machine 100, are connected by means of the third and fourth transport sections 202-3 and 202-4. The third transport section 202-3, near the operator side, includes a pair of guide rails extending in the x-direction (transverse direction) and mounted on the machine bed. The guide rails 271-3 support a base slide 272-3, which can be moved bidirectionally in the transverse direction (x-direction) to the end positions of the guide rails by means of a numerically controlled drive. The base slide supports another horizontally movable slide 273-3, which has its own drive and serves as a pallet carrier for holding a pallet. Since the pallet carrier belongs to the third transport section 202-3, it is also referred to as the third pallet carrier 260-3.

[0061] The third pallet carrier 260-3 does not require any components of a zero-point clamping system on its upper surface, as precise workpiece positioning is not necessary with this pallet carrier. Parallel to the longitudinal direction (y-direction), the third pallet carrier 260-3 has a width dimensioned such that, when moved in the first direction (transverse direction), it fits between the two angled support elements 261 of the vertically movable pallet carriers 260-1 and 260-2 attached to the longitudinal sides. This allows for the direct transfer of a pallet between the transversely movable third pallet carrier 260-3 and the vertically movable first pallet carrier 260-1, or the opposite second pallet carrier 260-2. The base carriage 272-3 and the additional carriage 273-3 it carries each have their own drive.This allows the carriage 273-3 to be moved like a kind of telescope beyond the area of ​​the lower carriage (base carriage) 272-3 and into the transfer area 262.

[0062] For example, if, in the depicted situation, the pallet 210-1 lying on the first pallet carrier 260-1 is to be transferred to the third pallet carrier 260-3, which can be moved laterally, the lifting carriage of the first pallet carrier 260-1 is first raised until the pallet is above the level of the third pallet carrier 260-3. Then, by moving the base carriage 272-3 and superimposed the movement of the second carriage it carries, the third pallet carrier 260-3 is moved horizontally into the area below the raised pallet 210-1. The lifting carriage of the first pallet carrier 260-1 is then lowered until the pallet rests on the third pallet carrier 260-3, and the lifting carriage is lowered further so that the pallet is completely released. Lateral transport in the x-direction can then take place using the third pallet carrier 260-3.

[0063] A reverse transfer is also possible. For example, in some embodiments, a loading and unloading position or loading and unloading station 185 is provided at the illustrated position of the third pallet carrier 260-3, centered between the longitudinal sides. Initially, a pallet with a workpiece holding device and workpiece can be mounted on the third pallet carrier 260-3 at this station. To transfer this pallet to the first pallet carrier 260-1, the latter is first moved downwards, allowing the pallet to be moved horizontally with the aid of the third pallet carrier to the first transfer position 204-1, located above the vertically movable lifting carriage of the first pallet carrier 260-1. The lifting carriage is then moved upwards with the first pallet carrier 260-1, taking over the pallet directly from the third pallet carrier 260-3 without any intermediate transfer devices. During this transfer operation, the pallet is moved to the first pallet carrier 260-1.During the lifting operation, the corresponding components of the zero-point clamping system on the pallet 210-1 and the first pallet carrier 260-1 also engage with each other, thus defining the position of the workpiece to be machined in relation to the honing machine.

[0064] The third pallet carrier, which can be moved laterally, is then moved back to the central position shown (loading and unloading position). As soon as this allows the first pallet carrier 260-1 to move horizontally, it can be moved towards the first workstation 180-1 to position the workpiece there.

[0065] The pallet carriers that interact at a transfer position are therefore adapted to each other in such a way that they can partially move into each other, whereby one of the pallet carriers interacting at the transfer position can perform lifting movements in order to carry out pallet lifting or lowering operations.

[0066] The fourth transport track 202-4, running near the rear of the machine base 110, connects the transfer positions 204-2 and 204-3 in a similar manner; these positions are located in the area of ​​the workstations. The fourth pallet carrier 260-4, which can be moved horizontally in the x-direction, has the same degrees of freedom as the third pallet carrier 260-3 described above, and therefore reference is made to its description.

[0067] Using the fourth transport route 202-4, it is possible, for example, to take a workpiece, which was initially processed at the first workstation 180-1, from the first pallet carrier 260-1 positioned there and transport it to the second workstation 180-2, where the pallet with workpiece is then taken from the associated second pallet carrier 260-2 and positioned for workpiece processing.

[0068] It is also worth mentioning that the transport routes 202-1 and 202-2 leading to the workstations in the longitudinal direction (y-direction) are designed with regard to the possible transport routes in such a way that the pallet carriers 260-1, 260-2 can be moved under the work units of the workstation so far to the rear (into the area of ​​the control 190) that the work units are freely accessible from the front, in order to be able to carry out a tool change conveniently without interference by a pallet carrier.

[0069] These few examples demonstrate that the Honing Machine 100 is a highly flexible honing machine that preferably requires exactly two honing units, meaning it can be configured with two spindles. The honing machine is suitable for the parallel machining of workpieces at two different honing stations. Even with this, workpieces can still be loaded and unloaded simultaneously.

[0070] Both workstations are equipped with precision workpiece positioning systems that allow for flexible component positioning in three mutually perpendicular axes. These component positioning systems include the horizontally movable horizontal slides 135-1, 135-2, which carry the honing units (and / or other machining units), as well as the first and second pallet carriers 260-1, 260-2, which can be moved into the workstation area and can be moved with positional accuracy in a second horizontal direction (y-direction) perpendicular to the direction of travel of the machining unit and also vertically (i.e., parallel to the spindle axis of the honing unit).

[0071] Each workstation can be equipped with a honing unit, thus configuring each one as a honing station. Additionally, one or more further work units, such as a deburring unit and / or a measuring unit, can be mounted on the same horizontal slide (or on a separately movable horizontal slide). Not every workstation needs to be configured as a honing station.

[0072] The machine's internal pallet transport system 200 makes a significant contribution to the high flexibility of possible machining scenarios. Its design allows for the free configuration of different transport paths via a control unit of the honing machine. In the illustrated embodiment, a maximum of three pallets are in use, with, for example, two pallets simultaneously positioned at the workstation during machining and one pallet in a loading position for loading or unloading. The pallet transport system of this embodiment can be described as including an integrated workpiece positioning system, comprising the horizontally and vertically movable first and second pallet carriers on the first and second transport paths.On the other hand, the configuration can also be described as follows: the component positioning systems in the honing machine take on both the task of component positioning in relation to the machining unit and tasks as part of pallet transport.

[0073] The overall concept also includes the ability to load or unload components directly onto the pallets located in the machine, as well as to change the entire pallet at the loading station. This is advantageous, for example, when significant setup time would otherwise be required for clamping and unclamping workpieces. Pallets can therefore be set up outside the honing machine and then fully loaded.

[0074] The honing machine is highly flexible and can accommodate both components or workpieces with relatively high individual weights and many individual, usually smaller, workpieces simultaneously on a pallet and process them in a single operation. Its advantages include high output and the possibility of variable honing spindle assignment for single-spindle or twin-spindle processes.

[0075] The honing machine shown can, for example, perform the following machining scenarios: Scenario 1: Honing, measuring, and deburring a workpiece with one bore; Scenario 2: Honing, measuring, and deburring a workpiece with multiple bores; Scenario 3: Honing, measuring, and deburring multiple workpieces with one bore; Scenario 4: Honing, measuring, and deburring multiple workpieces with multiple bores; Scenario 5: Double-spindle process, allowing simultaneous honing and loading; Scenario 6: Twin-spindle process, allowing simultaneous honing and loading.

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