EP3402629A1

EP3402629A1 - Honing machine

Info

Publication number: EP3402629A1
Application number: EP16820253.9A
Authority: EP
Inventors: Henning Klein; Roland Regler; Uwe Moos
Original assignee: Kadia Produktion GmbH and Co
Current assignee: Kadia Produktion GmbH and Co
Priority date: 2016-01-13
Filing date: 2016-12-21
Publication date: 2018-11-21
Anticipated expiration: 2036-12-21
Also published as: DE102016200295A1; HRP20220874T1; US20190001461A1; CN108883513A; US11389921B2; WO2017121590A1; DE202017000022U1; CN108883513B; EP3402629B1

Abstract

A honing machine (100) for honing bores in workpieces has a honing spindle (170), which honing spindle is mounted movably in a spindle housing (130), is rotatable about a spindle axis (172) by means of a rotary drive (150), can be driven in oscillation parallel to the spindle axis by means of a stroke drive, and, at a tool-side end, has a means for the fastening of a honing tool arrangement with an expandable honing tool. Furthermore, an expanding drive for expanding the honing tool is provided, wherein the expanding drive is connected to the spindle housing and is coupled to a feed rod (180) which runs in the interior of the honing spindle. The honing machine is characterized by a monocoque housing (150) which has a spindle housing section (150-1), which serves as spindle housing and which serves for accommodating the rotary drive (135), and an expanding system section (150-2), which is formed in one piece with the spindle housing section and which serves for accommodating the expanding drive (155).

Description

Honing

AREA OF APPLICATION AND PRIOR ART

The invention relates to a honing machine for honing holes in workpieces according to the preamble of claim 1.

Honing is a machining process with geometrically indeterminate cutting, in which a honing tool performs a two-component cutting movement and a constant surface contact between one or more cutting material bodies of the honing tool and the bore inner surface to be machined. The kinematics of an expandable honing tool is characterized by a superposition of a rotational movement, a running in the axial direction of the bore, oscillating lifting movement and a widening movement, which leads to a change in the effective diameter of the honing tool. At the bore inner surface usually results in a surface structure with intersecting machining marks. Honing finished surfaces can meet extremely high dimensional and dimensional tolerances requirements, so that many high loaded sliding surfaces in engines or engine components, e.g. Cylinder surfaces in engine blocks or internal bore surfaces in injection pump housings can be machined by honing.

A honing machine suitable for honing is a machine tool whose work spindle is generally referred to as a honing spindle. The honing spindle is movably mounted in a spindle housing, rotatable about its longitudinal central axis (spindle axis) by means of a rotary drive and oscillated in an oscillating manner parallel to the spindle axis by means of a lifting drive. At a tool-side end, the honing spindle has a device for fastening a honing tool arrangement with an expandable honing tool. For the expansion of the honing tool there are different concepts. Frequently, an expanding drive is provided for expanding the honing tool, wherein the expander drive is connected to the spindle housing and acts via a widening gear on a running inside the honing spindle feed bar, which indirectly or directly causes a radial displacement of cutting material of the honing tool.

In order to optimize the economic efficiency and quality of honing processes, highly dynamic direct drives for lifting and rotating are increasingly being used, which are honing operations with high lifting speeds (currently up to, for example, up to approx. 100 m / min) and speeds (in particular). time, for example, up to about 5000 rpm). There is a need for honing machines which fulfill their intended purpose even under very dynamic working conditions.

For highly dynamic movement of machine parts direct drives are known, especially in the design as a linear motor. In DE 102 25 514 B4 a honing machine is described, the lifting drive is a linear motor. Direct drives are characterized by the potential to enable high speeds and accelerations of the machine axis driven thereby with simultaneous frictionless motion generation.

TASK AND SOLUTION

The invention has for its object to provide a honing machine, which enables economical production of honed workpieces with short cycle times at high quality.

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 by reference for the purposes of the description.

A honing machine according to the claimed invention comprises a monocoque housing having a spindle housing portion serving as a spindle housing for accommodating the rotary drive and an expansion system portion integrally formed with the spindle housing portion for receiving the expander drive.

If the widening drive is coupled via a widening gear to the infeed rod, the widening gear is preferably accommodated in the widening system section. There are also gearless expansion systems, e.g. those in which the expansion drive is a plunger drive.

A monocoque housing offers over conventional solutions with separate housings for rotary drive and expander drive, among other things, the possibility of considerable weight savings, since due to the integrated design some housing parts, flanges, fasteners, etc. can be omitted. This brings specific advantages in honing machines. In honing machines, drives must also apply weight and acceleration forces in addition to the process forces. Particularly in the case of highly dynamic machines and / or vertical axis movements, this leads to the fact that large drive powers must be kept available, the usually in turn accompanied by an increase in the moving mass. A weight saving creates considerably better conditions here.

In addition to the weight savings, there are advantages in terms of the precision of the mutual alignment of expanding drive or expansion system and rotary drive and during assembly. While in conventional honing machines the expansion system has typically been manufactured as a separate housing from the spindle housing, which was flanged by means of a connecting flange to the spindle housing with rotary drive, these assembly steps can be omitted when using a monocoque housing. Because of the integrated housing design and the elimination of joints between separate housings, there is no longer the risk that the connections between separate housing parts may loosen with prolonged alternating stress.

It is possible to manufacture the monocoque housing from a conventional steel material. Preferably, however, further measures are taken to reduce weight. A monocoque housing could e.g. as an aluminum casting (aluminum or aluminum alloy, e.g., Al-Mg). Embodiments are considered particularly advantageous in which the monocoque housing is manufactured as a lightweight component using a lightweight construction material. If the monocoque housing movable with the honing spindle is a lightweight component, i. a component made using a lightweight construction material, then the mass moved can be significantly reduced over conventional solutions. A lower moving mass causes a higher acceleration of the mass is possible with the available power. This is particularly advantageous when honing, since there is an axial reciprocating component of motion during the stroke movement here. The benefit of vertical honing machines becomes even clearer, since, with a vertical arrangement of the axial movement, the reduction of the weight of the moving components additionally has a positive effect on the dynamic behavior of the honing machine.

In many machining tasks, the amplitude of axial movement is dictated by external constraints such as workpiece length. Increasing the maximum speed and the acceleration in the Umsteuerpunkten the lifting movement leads to an increased average axial velocity. Often the axial velocity limits the possible cutting speed and thus the achievable material removal. Therefore, with increased axial speeds ultimately shorter processing times and thus shorter cycle times for a workpiece can be achieved. Together with increased dynamics of moving machine parts, vibrations can also occur. These are usually undesirable, since the processing quality is reduced by this disruptive factor. By using suitable lightweight construction materials with high rigidity and good damping properties instead of solid components made of steel or other conventional construction materials, unwanted vibrations can be attenuated more strongly, so that the processing result is improved.

A reduced moving mass can further contribute to reducing the energy consumption of a processing machine, so that here an increase in energy efficiency as an additional benefit arises.

According to a development, the monocoque housing is produced using a fiber composite material. Components made using (at least) one fiber composite can provide sufficient stiffness and good damping at very low mass. By using a fiber composite material to manufacture or manufacture a honing machine movable honing machine component, it is possible to reduce the weight and inertia of the respective component as compared to a similarly designed and dimensioned metallic material component (eg, steel material) Aluminum material). At the same time, sufficient rigidity of the corresponding component can be ensured. This can increase the dynamics of honing without sacrificing quality.

Preferably, a carbon fiber reinforced plastic (CFRP) is used as a fiber composite material, which may also be referred to as carbon fiber reinforced plastic (KFK). In such a fiber composite carbon fibers are embedded in a matrix of plastic (for example, an epoxy resin, another thermoset or a thermoplastic). The mechanical properties of the cured fiber composite benefit from the tensile strength of the carbon fibers. The plastic matrix prevents the fibers from shifting against each other under load and also contributes to the damping properties of the material. Alternatively or additionally, it is e.g. also possible to use as a fiber composite material a glass fiber reinforced plastic (GRP). In the manufacture of a component movable with the honing spindle, two or more fiber composites of different types may be combined.

A lightweight construction component made using a fiber composite material may consist essentially entirely of the fiber reinforced plastic material. In In some cases, it is also possible to design the corresponding lightweight component to have a core of low mass density enclosed by a sheath of fiber composite. As a result, with at least constant mechanical stability of the component, the movable mass can be further reduced. For example, the core may consist essentially of a pressure-stable light material in which cavities are enclosed.

Alternatively or additionally, it is also possible to produce the monocoque housing and / or one or more other components movable with the honing spindle using a metal foam, for example an aluminum foam.

Furthermore, it is alternatively or additionally possible that the rotatably mounted honing spindle is designed as a lightweight component.

In some embodiments, the linear actuator comprises a linear motor with a fixed to a stand of the honing machine primary part and a relative to the primary linearly movable secondary part, which is integrated in a spindle housing carrying the carriage, wherein at least one component of the carriage is designed as a lightweight component. For example, the carriage may include a carriage plate, which is designed as a lightweight component.

In addition to the considerable advantages in the operation of the honing machine can be achieved in the production advantages. In some embodiments, it is provided that the lightweight construction component, in particular the monocoque housing, possibly also other components, is produced using a near net shape production process, which comprises at least one manufacturing step of laminating, foaming and / or 3D printing. Such production methods generally come with relatively little post-processing or machining without machining and allow a fast, cost-effective production of even complex shapes.

The components of the honing machine are exposed during operation partially considerable dynamic and static loads. In order to be able to withstand this permanently, it is provided in preferred embodiments that the lightweight component has at least one connection point for connecting the lightweight component with another component an insert not consisting of a lightweight construction material. The insert may, for example, consist essentially of steel, aluminum, magnesium, brass sing or titanium. As a result, for example, in the area of screw connections to adjacent components, a stabilization of the lightweight component can be achieved.

The ability to quickly and inexpensively manufacture even complex shapes using a lightweight construction material is utilized in some embodiments by providing at least one passageway leading from an entrance opening to an exit opening through which a flowable medium, or at least one, flows through the lightweight component Lead passed or can be passed. Such passageways may be provided, for example, to pass coolant lubricant lines, pneumatic lines, electrical lines and / or the like. If such lines are passed through the interior of a lightweight component, they can be protected by the lightweight component against environmental influences and the entire honing machine also makes a "tidy" impression.A passage can also directly as a conduit for a flowable medium, eg Coolant or coolant can be used.

The honing machine can be configured as a horizontal honing machine (with a horizontally oriented honing spindle) or as a vertical honing machine (with a vertically oriented honing spindle). Special advantages are offered in vertical honing machines, since there the influence of the weight on the lifting movement can be reduced by using lightweight components.

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 some components of a honing machine according to a first embodiment of the invention, wherein Fig. 1A shows a longitudinal section and Fig. 1B shows a vertical plan view;

Fig. 2 shows a section of a honing machine according to a second embodiment of the invention;

Fig. 3 shows schematically the structure of a honing machine of conventional construction. DETAILED DESCRIPTION OF THE EMBODIMENTS

To facilitate the understanding of improvements and advantages of honing machines according to the invention in comparison with the prior art, an example of a conventional honing machine 300 will first be explained with reference to FIG. 3, which in principle may be constructed as described in DE 102 25 514 B4. On a processing platform, a workpiece 390 is clamped, the bore 392 is to be honed using the honing tool 380. The honing tool 380 is received in a cone at the lower end of a honing spindle 370 and is moved in operation of the honing machine together with the honing spindle in a vertical lifting movement up and down. As a result, the vertical movement component of the working movement of the honing tool is performed.

The honing spindle is movably mounted in a metallic spindle housing 330 and can be rotated about its spindle axis (longitudinal central axis) by means of a rotary drive in the form of an electric motor integrated into the spindle housing. As a result, the rotary component of the working movement of the honing tool is generated.

The honing spindle is driven in an oscillating manner by means of a linear actuator parallel to its spindle axis. The lifting drive comprises a linear electric motor with a primary part attached to a stand 302 of the honing machine and a secondary part which can be moved linearly relative to the primary part. The secondary part is integrated in a carriage 310 made of steel, which is guided on a vertical guide device linearly movable. The carriage 310 carries the spindle housing 330, which thus can be moved vertically up and down together with the carriage. The secondary part is the moving part and the primary part of the stationary part of an electric linear motor.

For the expansion of the expandable honing tool, ie for the change of the effective diameter of the honing tool, an electrical expansion drive is provided, which is coupled via a Aufweitgetriebe with an axially inside the honing spindle 370 guided infeed rod. The metallic housing 350, which surrounds the expansion drive, is flanged to the top of the spindle housing.

For machining the bore 392, the honing unit with spindle housing 330 and honing spindle 370 and the honing tool 380 accommodated therein are lowered so far that the honing stones 382 of the honing tool dip into the bore. Then, the honing spindle 370 is simultaneously reciprocated (that is, up and down) and rotated. The two working movements are the coordinated so that on the inner surface of the machined bore creates a typical for honing Kreuzschliffmuster.

The vertical support 302 and the slides for the carriage 310 mounted thereon and the primary part of the linear motor belong to the fixed components of the honing machine. The carriage 310 with the secondary part of the linear motor integrated therein and all components carried by the carriage are among those components which are moved together in the honing spindle during machining.

With reference to Figures 1A, 1B and 2, embodiments of honing machines formed in accordance with the claimed invention will now be described. The stationary components can be designed in the same way as described in connection with FIG. 3. Also, the honing tool and the means for securing the honing tool assembly with an expandable honing tool at the tool-side end of the honing spindle may be structurally similar or identical to those of the prior art. Important differences lie in the structure and partly in the design of components of the honing machine, which are moved during machining together with the honing spindle.

The honing spindle 170 of the embodiment is rotatably supported within a housing 150 by means of rolling bearings so that it can rotate about its vertical spindle axis 172 relative to the housing 150. The rotary drive 135 is designed as an electric direct drive and comprises a fixedly mounted in the housing 150 stator 135-1 and a mounted on the outside of the honing spindle 170 rotor 135-2, which can rotate within the stator.

The honing spindle 170 has an inner through-hole in which a feed rod 180 of the expansion system is guided axially movable. The feed rod rotates with the speed of the honing spindle with this. The axial movement of the Zustellstange is effected by means of a Aufweitantriebs 155, which is designed as an electric direct drive. A stator 155-1 of the expanding drive is fixedly mounted with respect to the housing 150. The rotatable relative to the stator rotor 155-2 is coupled to a spindle nut 157, the internal thread of which cooperates with the external thread of a threaded spindle 158 of the expansion drive. The threaded spindle 158 is fixedly attached to a fixed housing 150 connected to the housing cover. Upon rotation of the rotor, the spindle nut runs along the threaded spindle, whereby the (shorter) rotor is axially moved axially relative to the (longer) stator. The spindle nut is coupled to the feed rod via a receiving sleeve 159 which rotates with the spindle nut and is rotatably mounted relative to the feed rod so that the axial movement of the spindle nut is transferred to the Zustellstange. Thus, rotation of the rotor 155-2 of the expansion drive 155 relative to the stator causes axial movement of the feed rod 180 parallel to the spindle axis 172. This delivery may be clocked or regulated. The combination of spindle 158 and spindle nut 157 acts as a Aufweitgetriebe that converts the rotation of the rotor in an axial movement of the Zustellstange.

A special feature is that the housing 150 essentially consists of a single component which serves both as a housing for the rotary drive 135 of the honing spindle 170 and as a housing for the expander drive 155. For this purpose, the housing 150 has a spindle housing section 150-1, which encloses the stator 135-1 of the rotary drive 335 for the honing spindle, as well as an integrally formed with the spindle housing section, smaller diameter expansion system section 150-2, the u.a. for receiving the expansion drive 155 is used. This integration of several separately manufactured in the prior art components and then mounted together components in a single component is referred to here as a monocoque housing 150.

Compared to the prior art according to FIG. 3, inter alia, the interface between the housing of the spindle motor and the housing separate therefrom, which surrounds the expansion drive and the widening gear, is eliminated. Thus, potential causes of failure, such as unintentional release of connections in the area of the interface during prolonged operation and possible misalignments in the alignment of expanding drive and spindle drive can be avoided in principle.

Another particularity is that a plurality of components movable together with the honing spindle 170 are manufactured as lightweight components using at least one lightweight construction material.

For example, the housing 150 (monocoque housing) is a one-piece, elongated hollow body, the wall portions of which are made using a fiber composite material, such as carbon fiber reinforced plastic (CFRP). The outer and inner walls of the monocoque housing essentially consist of layer-laminated fiber composite material FV, while between the outer walls a core K with low mass density, which is filled for example by pressure-stable filler with glass beads or other stiff, lightweight hollow bodies (see detail magnification in Fig. 1A). In comparison to a housing made of steel material or another solid metallic material of the same dimensions, this results in a significant weight savings with at least constant rigidity. Furthermore, the linearly guided on the stationary stand 102 slide 1 10 at the same dimension as a conventional slide much easier, since the slide plate 1 12 is made as an essential component of the carriage also as a lightweight component using a fiber composite material. The integrated therein components, such as the secondary part of the linear motor for the lifting movement can be configured as in the conventional honing machine.

In the carriage plate 1 12 extends from top to bottom continuous through channel 1 13, can be passed through the starting from a (not shown) upper media port, a cooling liquid for tool cooling. Further extending in the carriage plate 1 12 and the monocoque housing further through holes 1 14A, 1 14B, which lead from an upper media port through horizontal sections into the interior of the monocoque housing. These serve for the supply of cooling fluid for the cooling of the rotary drive 135. Through further vertical through-channels 15, electrical lines, e.g. for encoders or sensors.

The embodiment of Fig. 2 is similar or identical in most details to the embodiment of Fig. 1. A difference is in the configuration of the inner contour of the monocoque housing 250 in the region of the transition between the expansion system section 250-2 and the adjoining spindle housing portion 250-1 larger diameter. In the exemplary embodiment of FIG. 1, the stator of the widening drive is supported axially on an annular collar 156 which, starting from the housing wall, protrudes inwards and surrounds a passage opening for the feed rod. To produce this annular collar or this shoulder two forms are used in the production of the embodiment, namely a shape which extends from the top of the inner region to the shoulder (annular collar 156) and another form, which extends from the lower passage opening for the honing spindle reaches to the shoulder.

In the variant of Fig. 2 eliminates this collar, which makes it possible to produce the monocoque housing 250 with only a single inner mold, which can be inserted from the side of the larger diameter and taken on this page also. In order to ensure the support function for the stator, it is provided in the embodiment of Fig. 2, that that inner sleeve 255, which holds, among other things, the upper pivot bearing for the honing spindle, is continued in the direction of the smaller diameter and pulled inward at the end, so that a support surface for the stator is formed.

Some aspects of preferred embodiments may be described as follows The mass of some components of a honing spindle assembly that are typically subject to movement is reduced by the use of fiber composites and / or other lightweight construction materials. While drive and bearing components can not be primarily implemented in a composite material, the housing and connection components are available in the form of composite material, for example glass fiber reinforced or carbon fiber reinforced plastic (GRP / CFRP). Furthermore, foamed materials such as metal foams (eg aluminum foam) in raw form, as sandwich components with cover plates or as filling material between internal and external geometry are possible.

While steel has a density of about 7.85 g / cm ³ , aluminum 2.71 g / cm ³ , and titanium has a density of 4.5 g / cm ³ , the tensile strength, a measure of the mechanical strength of the material for steel approx. 300-900 N / mm ² for aluminum approx. 60-500 N / mm ² , and for titanium approx. 300-1000 N / mm ² .

Glass fiber composites have a tensile strength of up to 1000 N / mm ² at a density of about 2 g / cm ³ , depending on the direction of the fibers. Carbon fiber composites have a tensile strength of up to 1400 N / mm ² at a density of about 1.5 g / cm ² . Aramid fiber reinforced plastics have even lower densities of about 1.4 g / cm ³ at similar tensile strengths as carbon fiber reinforcement plastics. Pure aluminum foams have a density of -0.5 g / cm ³ . With composite or sandwich materials appear about 1, 0 g / cm ³ realistic.

A material-appropriate design of the geometry of the components that can be moved using the honing spindle can help to exploit the potential of lightweight construction materials when constructing a honing spindle unit. This can i.a. mean that components can be designed as slim as possible and only in places that absorb forces or derive more material should be present.

Reduction of joints as well as a substitution of screw connections, eg by adhesive bonding or lamination of connecting parts, can reduce the moving mass. In the case of laminated or foamed components (such as GRP, CFRP, aramide fibers, etc.), the use of full metal inserts is possible in the area of joints for structural reasons, for example, from the materials steel, aluminum, magnesium, brass or titanium. In order to implement the concept of lightweight construction, it is furthermore possible to use the monocoque proposed in this application, ie a holistic housing body. For example, a continuous pipe is possible, in which all components (spindle motor for generating the tool rotation, expansion gear for active tool delivery and clamping / releasing the tool in the machining spindle ...) as well as connecting elements and interfaces (cables, media) are integrated. As a result, the number of components used, and thus the mass, can be reduced.

A near-net shape production makes it possible, with minimal post-processing, for example only on fits and screw-on surfaces, and subsequent assembly of preassembled individual modules to produce a mass and performance-oriented processing unit. By reducing the number of components, there are fewer interfaces, reducing the likelihood of loose connections. The monocoque housing derives the forces occurring as best as possible within the housing body. These aspects increase the accuracy of the processing unit.

Claims

claims

1 . Honing machine (100) for honing holes in workpieces with:

a honing spindle (170), the

is movably mounted in a spindle housing (130),

by means of a rotary drive (150) about a spindle axis (172) is rotatable,

by means of a linear actuator parallel to the spindle axis oscillating antreibar is and

has a device for fastening a honing tool arrangement with an expandable honing tool at a tool-side end, and

a widening drive for widening the honing tool, the widening drive being connected to the spindle housing and being coupled to a feed rod (180) running inside the honing spindle;

characterized by a monocoque housing (150) having a spindle housing portion serving as a spindle housing (150-1) for receiving the rotary drive (135) and an expansion system portion (150-2) formed integrally with the spindle housing portion for receiving the Expanding drive (155).

2. honing machine according to claim 1, characterized in that the expansion drive (155) via a Aufweitgetriebe with the Zustellstange (180) is coupled, wherein the Aufweitgetriebe in the expansion system section (150-2) is housed.

3. honing machine according to claim 1 or 2, characterized in that the monocoque housing (150) is made as a lightweight component using a lightweight construction material.

4. honing machine according to claim 3, characterized in that the monocoque housing (150) is made as a lightweight component using a fiber composite material, wherein the fiber composite material is preferably a carbon fiber reinforced plastic (CFRP) or a glass fiber reinforced plastic (GRP).

5. Honing machine according to one of the preceding claims, characterized in that in addition to the monocoque housing (150) at least one further with the honing spindle movable component of the honing machine as a lightweight component using a lightweight construction material, in particular a fiber composite material produced.

6. Honing machine according to claim 4 or 5, characterized in that the lightweight component produced using a fiber composite material has a core (K) low mass density, which is enclosed by a sheath made of fiber composite material (FV), wherein preferably the core consists essentially of a pressure-stable light material in which cavities are enclosed.

7. Honing machine according to one of the preceding claims, characterized in that the lifting drive comprises a linear motor with a stator attached to a (102) of the honing primary and a relative to the primary linearly movable secondary part, which in a spindle housing (150) carrying carriage ( 1 10) is integrated, wherein a slide plate (1 12) and / or at least another component of the carriage (1 10) is designed as a lightweight component

8. Honing machine according to one of claims 3 to 7, characterized in that the lightweight component is made using a near net shape manufacturing process, which comprises at least one of the following steps: laminating; Foam; SD printing.

9. honing machine according to one of claims 3 to 8, characterized in that the lightweight component at least one connection point for connecting the lightweight component with another component has a non-existing lightweight construction material insert, wherein preferably the insert substantially made of steel, aluminum, magnesium, brass or titanium.

10. Honing machine according to one of claims 3 to 9, characterized in that in a lightweight component (150, 1 12) at least one leading from an input opening to an output port passageway (1 13, 1 14A, 1 14B, 1 15) is formed is, through which a flowable medium or at least one line is passed or can be passed.

1 1. Honing machine according to one of the preceding claims, characterized in that the honing machine (100) is a vertical honing machine with a vertically oriented honing spindle.