US20200206865A1

US20200206865A1 - Honing tool

Info

Publication number: US20200206865A1
Application number: US16/633,044
Authority: US
Inventors: Erwin BAUMGARTNER; Norbert Baumgartner; Joerg Necker
Original assignee: Gehring Technologies GmbH and Co KG
Current assignee: Gehring Technologies GmbH and Co KG
Priority date: 2017-07-27
Filing date: 2018-07-27
Publication date: 2020-07-02
Also published as: EP3658330A1; CN110944795A; JP2020529327A; WO2019020779A1; DE102017117069B4; EP3658330B1; JP7136883B2; DE102017117069A1; CN110944795B; ES2904978T3

Abstract

The present invention relates to a honing tool and a method for honing the inner surface of an opening in a workpiece with a honing tool according to the invention.

Description

BACKGROUND

The present invention relates to a honing tool for honing the inner surface of an opening in a workpiece according to the preamble of claim 1, as well as a method for honing the inner surface of an opening in a workpiece with such a honing tool.
During honing, the respective honing tool is inserted into the opening to be machined. To this purpose, the honing tool can be moved into the stationary opening, or the workpiece with the opening can be moved relative to the stationary honing tool such that the honing tool is inserted. Subsequently, the movement of a rotation with superimposed up and down movement of the honing tool in the opening is carried out, which is typical for honing. Also in this case, the workpiece or the honing tool or both can be moved so that the corresponding relative movement between workpiece and honing tool is present.
When honing the openings, in particular bores, these openings have usually been machined in preceding steps, wherein a nominal dimension of the openings is often not achieved with sufficient certainty and accuracy by the preceding steps. In order to ensure that the opening to be honed has a nominal dimension, a check measurement is usually carried out prior to honing. Two honing operations are often required during honing. For example, the first honing operation may aim at a correction of diameter and shape accuracy, and the second honing operation can be used to smooth the surface. Honing machines usually have a separate honing station with a respective separate honing tool for each of these honing steps. It is often desired or necessary to check the result of the respective honing process at an additional re-measuring station. The execution of these possibly quite numerous working steps requires complex honing machines and an extensive workpiece transport within the honing machine.
It is an object of the present invention to provide a honing tool that enables an operation of a honing machine which is as efficient as possible. Furthermore, it is an object of the present invention to provide a method which enables machining of an opening as efficient as possible and with a short processing time.
These objects are achieved by the honing tool according to claim 1 or by the method according to claim 15, respectively.
The honing tool according to the invention is formed with a tool body extending in an axial direction and having a honing section which comprises a group of hone strips, wherein the honing tool comprises a workpiece checking element for checking a size and/or a position of the opening the workpiece checking element being arranged on the tool body so as to be movable relative to the tool body preferably in the axial direction. It is also conceivable that the workpiece checking element is arranged so as to be movable in a radial direction relative to the tool body, in order to check whether the opening in the workpiece has a sufficient opening width and/or to check for a positioning or alignment error of the opening of the workpiece when the honing tool moves into the opening.
The present workpiece checking element is therefore not used to monitor the honing process, but to check whether the workpiece to be machined has been correctly positioned or has been correctly machined in a preceding working step. This checking can be carried out by means of the workpiece checking element during the insertion operation, so that a separate pre-checking can be omitted. The workpiece checking element is thus designed and arranged to monitor the insertion operation of the honing tool. By means of the workpiece checking element it is therefore possible to check during the insertion operation whether the same can be carried out as intended. In other words, in contrast to measuring strips, for example, which allow to check the honing process itself, the workpiece checking element of the honing tool according to the invention has nothing to do with the actual machining process of the honing. Rather, the workpiece checking element enables to integrate a pre-checking of the alignment or the bore size of the workpiece, respectively, into the insertion operation of the honing tool. Conventionally, such a check of whether the workpiece or its bore has a sufficient width and/or is correctly positioned to insert the honing tool was carried out in a separate step using separate measuring devices.
In particular, the honing tool according to the invention is a honing tool for machining an opening in a gear wheel.
The workpiece checking element can be used in particular to ensure that the opening in the workpiece has a sufficient opening width, e.g. that a nominal dimension has been achieved in preceding machining steps. The workpiece checking element can also or additionally serve to exclude a positioning or alignment error of the opening of the workpiece.
In particular, if the opening in the workpiece does not have a sufficient opening width, the honing tool may be damaged when conventional honing tools are inserted. For this reason, the opening width is usually checked for a nominal dimension at a preceding working station. The movable support of the workpiece checking element allows to insert the honing tool into the opening, wherein if the opening width of the opening is less than the specified dimension, the workpiece checking element contacts the inner surfaces of the opening, whereupon the insertion operation can be interrupted. The movable arrangement of the workpiece checking element relative to the tool body ensures that neither the honing tool nor the workpiece will be damaged. In other words, the present honing tool now offers the possibility to check for sufficient width and correct alignment of the opening by means of the workpiece checking element during insertion, while there is no risk of damaging the bore or the hone strips, which could be damaged by “hitting” the bore wall if the opening width is too small or if the opening is inclined.
The term of inserting the honing tool into the opening or respective moving or retracting the honing tool must not be understood in a restrictive way within the meaning of the present application. The above terms refer to a relative movement between the honing tool and the workpiece. For example, the workpiece can be held stationary and the honing tool can be moved, or the honing tool can be held stationary and the workpiece can be moved. It is also conceivable to move honing tool and workpiece simultaneously.
Within the meaning of the present application, honing also means a relative movement between the honing tool and the workpiece, wherein the honing tool and/or the workpiece can be moved. The honing process comprises a superimposition of translational and rotational relative movements between the workpiece and the honing tool.
Preferably, the workpiece checking element is coupled to a detecting device, the detecting device being adapted to detect a movement of the workpiece checking element relative to the tool body. Preferably, the detecting device is coupled to a controller such that the controller interrupts the insertion of the honing tool into the opening when the detecting device detects a movement of the workpiece checking element relative to the tool body.
Optionally, the workpiece checking element is resiliently supported on the tool body. In this manner, the workpiece checking element is always biased into a designated position and offers some resistance to any movement. The resilient support can be realized by mechanical springs, preferably metallic springs. Mechanical springs may be designed as coil springs or leaf springs. It is also conceivable that the workpiece checking element is resiliently supported via an elastic polymer material. A pneumatic or hydraulic suspension of the workpiece checking element is also conceivable. A magnetic or electromagnetic suspension of the workpiece checking element is also conceivable.
Optionally, the workpiece checking element is biased into an initial position and is arranged on the tool body such that the workpiece checking element is moved out of the initial position when the workpiece checking element comes into contact with the workpiece, in particular during insertion of the honing tool into the opening of the workpiece. If the workpiece checking element is moved out of its initial position, this can be detected and the honing tool's insertion operation into the workpiece can be aborted. This reliably prevents any damage of the workpiece or the honing tool.
Optionally, the workpiece checking element comprises a contact portion for contacting the workpiece, which contact portion expands in a radial direction when viewed from a workpiece-side end of the tool body along the axial direction. A corresponding workpiece checking element can be inserted with its “tip” into the workpiece and the contact section contacts the edge of the opening if the opening width is less than a nominal dimension.
Optionally, the workpiece checking element is ring-shaped, and preferably extends around the tool body. This results in the opening of the workpiece to be checked around the circumference of the honing tool. Preferably, the contact section described above extends around the honing tool, wherein the contact section may have discontinuities at some locations along the circumferential direction. The discontinuities may serve for forming a passage for a cooling lubricant so that the same cannot accumulate above the workpiece checking element during honing.
The workpiece checking element can also be formed conical or like a truncated cone. Forming the workpiece checking element as a spherical segment is also possible. Preferably, the workpiece checking element has a radial cross-section which widens in the axial direction when viewed from the workpiece in the axial direction. Preferably, a workpiece checking element according to the embodiments mentioned in this paragraph is arranged at the workpiece-side end of the tool body or, respectively, forms the part of the honing tool which is closest to the workpiece in axial direction.
Optionally, the workpiece checking element is arranged, in an axial direction, between the workpiece-side end of the tool body and the honing section, or the workpiece checking element forms a workpiece-side end of the tool body. In this manner, the workpiece checking element is formed, in the direction of insertion, in front of the honing section and any damage to the hone strips, for example due to the opening width of the opening to be machined being too small, is reliably prevented.
Optionally, the honing tool comprises a second honing section comprising a second group of hone strips, wherein the first honing section is arranged on the tool body spaced apart from the second honing portion in the axial direction. In this manner, a further honing operation can be carried out with the same honing tool without requiring retraction of the honing tool from the opening or any other intermediate step.
Optionally, the honing tool comprises a third honing section comprising a third group of hone strips, wherein the first honing section and the second honing section are arranged on said tool body spaced apart from the third honing section in the axial direction. In this manner, a further honing operation can be carried out with the same honing tool without requiring retraction of the honing tool from the opening or any other intermediate step. Correspondingly arranged fourth, fifth and further honing sections are conceivable, wherein the honing sections can preferably carry out different honing operations.
Preferably, the first honing section is arranged, in the axial direction, between the workpiece checking element and the second honing section. It is advantageous that the first honing section is designed to perform a pre-honing operation and the second honing section is designed to perform a final honing operation.
The hone strips of the two honing sections can be arranged offset to each other in the circumferential direction or can be equally arranged in the circumferential direction in both honing sections.
Optionally, the workpiece checking element is coupled to a pneumatic or hydraulic actuator such that the pneumatic or hydraulic actuator changes a flow cross-section of a pneumatic or hydraulic checking medium channel when the workpiece checking element is moved out of its initial position. Preferably, the checking medium channel can be supplied with compressed air. The actuator is preferably rod-shaped and motion-coupled with the workpiece checking element. Preferably, the actuator is arranged such that it extends into the region of an intersection of the checking medium channel when the workpiece checking element or actuator is moved from its initial position. Preferably, the actuator blocks the crossing of the checking medium channel when the workpiece checking element or the actuator is moved from its initial position.
Optionally, the honing tool comprises at least one air measuring nozzle which, when viewed in the axial direction, is arranged offset with respect to the hone strips, in particular, when viewed from a workpiece-side end of the tool body, behind the hone strips of one of the honing sections, preferably of all of the honing sections, and/or comprises at least one air measuring nozzle which, when viewed in the axial direction, is located adjacent to the hone strips of the honing section or of one of the honing sections, respectively, preferably wherein the honing tool comprises at least one air measuring nozzle per honing section which is arranged adjacent to the hone strips of the respective honing section when viewed in the axial direction. An air measuring nozzle within the meaning of the present application may in this case relate to at least two nozzles communicating fluidically with each other, which preferably are located opposite to each other in the circumferential direction.
The term “behind the hone strips” refers to an arrangement in which the corresponding air measuring nozzle is located behind the hone strips when viewed from the workpiece-side end of the honing tool. Such an air measuring nozzle is particularly suitable for the subsequent measurement of the result of a honing operation. Such an air measuring nozzle is also called an air measuring nozzle for re-measuring.
The term “adjacent to the hone strips when viewed in the axial direction” refers to an arrangement of the corresponding air measuring nozzle in which the air measuring nozzle is located in the region within the axial extension of the hone strips, when viewed in the axial direction. Such an air measuring nozzle is arranged between the hone strips, when viewed in the circumferential direction. Such an air measuring nozzle is particularly suitable for in-process measurement of the result of a honing operation. Such an air measuring nozzle is also referred to as an air measuring nozzle for in-process measurement, wherein it can also be used for a follow-up check of the result of a honing operation.
The air-measuring nozzle for re-measuring preferably extends further outwards in radial direction than an air-measuring nozzle for in-process measuring. Preferably, the nozzle cross-sections of the air measuring nozzles for re-measurement are smaller than the nozzle cross-sections of the air measuring nozzles for in-process measurement. This allows to achieve a higher accuracy during re-measurement.
Preferably, the actuator is arranged such that when the workpiece checking element or actuator is moved from its initial position, it disconnects a connection between an air measuring nozzle and a part of a measuring air channel. In this case, the air measuring nozzle disconnected from the measuring air channel can be an air measuring nozzle for re-measuring or for in-process measuring with a corresponding arrangement relative to the hone strips.
The rod-shaped actuator should be long enough so that, after the interruption of the checking medium channel, a sufficient additional operating displacement can be covered before the insertion of the honing section is interrupted. Preferably, the honing section is spaced apart from the workpiece checking element at least one sixth, preferably one quarter, of its axial extension, preferably also when the latter is deflected from its initial position.
Optionally, the actuator coupled to the workpiece checking element is a pneumatic actuator, and the checking medium channel, the flow cross-section of which is changed by the actuator, is pneumatically connected to a measuring air channel via which at least one air measuring nozzle, preferably a plurality of air measuring nozzles, can be supplied with measuring air. In this manner, the construction of the honing tool according to the invention becomes particularly simple, as only a few compressed air channels must be formed in the honing tool.
Optionally, the honing tool comprises an infeed device, by which the respective hone strips of the two honing sections are feedable in the radial direction independently of each other or always simultaneously. If the hone strips of the individual honing sections can be fed separately, only the corresponding honing section may be fed as required. If the hone strips of the honing sections can be fed in radial direction always simultaneously by the infeed device, the honing tool, in particular the infeed device, may be made simpler and more robust. An infeed device can be, for example, a piezo-based actuator for the hone strips, which is particularly suitable if the hone strips shall be feedable individually.
Optionally, the infeed device has an infeed cone for each honing section which is designed to interact with wedge surfaces of the hone strips in order to convert an axial movement of an infeed element into a radial infeed of the hone strips, preferably wherein the infeed cones of the honing sections are arranged on a single infeed element such that both infeed cones are moved upon movement of the infeed element. In this manner, the honing tool can be constructed particularly easy and is therefore inexpensive to manufacture.
Optionally, the honing tool comprises a brush section. After honing, the opening can further be smoothed and/or deburred by the brush section. Preferably, the honing section(s) and the air measuring nozzle(s) are located between the brush section and the workpiece-side end of the tool body, when viewed in axial direction.
Optionally, a tool guide is arranged on the honing tool in the region of the workpiece-side end of the tool body. Such a tool guide is provided in order to rigidly support the honing tool with respect to a guide bush. Such a design of the honing tool is usually used together with a floating support or cardanic support of the workpiece. Part of the invention is therefore also a honing machine having a honing tool, which is formed with the tool guide described above, and a guide bush, which is designed to accommodate the tool guide. Preferably, such a honing machine comprises a device for the floating support or cardanic support of the workpiece.
Part of the invention is also a method for honing the inner surface of an opening in a workpiece, in particular in a gearwheel, with a honing tool according to one or more of the above-described embodiments, the method comprising the following steps in succession:
(a) axially inserting the honing tool into the opening and pre-checking the width and/or position of the opening in the workpiece by means of the workpiece checking element;
b) honing the opening by the hone strips of the honing section, preferably measuring the opening width via an air measuring nozzle;
preferably c) axially moving the honing tool, in particular further axially inserting the honing tool into the opening, and re-measuring the opening width via an air measuring nozzle which is spaced apart from the honing section of step b) in the axial direction;
preferably d) axially moving the honing tool, in particular further axially inserting the honing tool into the opening, and subsequently honing the opening by the hone strips of the second honing section, preferably measuring the opening width via an air measuring nozzle which is arranged adjacent to the hone strips of the second honing section when viewed in the axial direction;
preferably e) re-measuring the opening width via an air-measuring nozzle which is arranged adjacent to the hone strips of the second honing section of step d) when viewed in the axial direction, or axially moving the honing tool, in particular further axially inserting the honing tool into the opening, and re-measuring the opening width via an air-measuring nozzle which is spaced apart from the second honing section of step d) in the axial direction;
preferably f) axially moving the honing tool, in particular further axially inserting the honing tool into the opening, and subsequent brushing the opening by the brush section of the honing tool;
g) axially retracting the honing tool from the opening.
The term “the following steps in succession” means that the steps mentioned are carried out temporally one after the other in the order mentioned, but further steps can be carried out between the steps mentioned. The method according to the invention allows to carry out a pre-checking and a honing operation and, if necessary, one or more in-process measurements or re-measurement(s) and, if necessary, a further honing operation with a single insertion operation. Conventionally, such a sequence of machining and measuring steps required individual working steps, which were often associated with further workpiece transport. The method according to the invention allows to carry out the complete machining at a single working station with a single insertion and retraction operation of the honing tool.

BRIEF DESCRIPTION OF THE DRAWINGS

Further characteristics, application possibilities and advantages of the invention can be derived from the following description of embodiments of the invention, which are explained on the basis of the drawings, wherein the characteristics can be essential for the invention, both singly and in different combinations, even if this is not explicitly pointed out again.

FIG. 1 is a side view of a honing tool according to the invention;

FIG. 2 is a sectional view of the honing tool of FIG. 1;

FIG. 3 is a sectional view of the honing tool of FIG. 1 in another sectional plane;

FIG. 4 is a sectional view of the honing tool of FIG. 1 in another sectional plane;

FIG. 5 is a sectional view of the honing tool of FIG. 1 in another sectional plane;

FIG. 6 is a sectional view of another honing tool according to the invention;

FIG. 7 is a sketch of a sequence of the method according to the invention;

FIG. 8 is a sketch of an alternative sequence of the method according to the invention; and

FIG. 9 is a sketch of an alternative sequence of the method according to the invention.

DETAILED DESCRIPTION

In the following Figures, corresponding components and elements have the same reference signs. For the sake of better clarity, not all reference signs are shown in all Figures.
FIG. 1 shows a honing tool 10 according to the invention for honing an inner surface 12 of an opening 14 in a workpiece 16, wherein workpiece 16 is not shown in FIG. 1. Honing tool 10 comprises a tool body 17 which extends in an axial direction A from a workpiece-side end 18 to a workpiece-far-side end 20. At workpiece-far-side end 20, honing tool 10 has a coupling section 22, and an infeed pin 24 protrudes from the honing tool.
Adjacent to coupling section 22, honing tool 10 comprises a connection section 25. In the region of connection section 25, honing tool 10 comprises a first connection 26 for measuring air and a second connection 28 for measuring air. Connections 30 for a cooling lubricant are also located in the region of connection section 25.
Adjacent to connecting portion 25, honing tool 10 comprises a functional portion 32. In the present embodiment, a workpiece checking element 34, a first honing section 36, a second honing section 38, and a brush section 40 are arranged in functional section 32. Functional section 32 also comprises an in-process measuring arrangement 42 with a first air measuring nozzle 44 or a plurality of first air measuring nozzles 44, and a follow-up measuring arrangement 46 with a second air measuring nozzle 48 or a plurality of second air measuring nozzles 48.
A tool guide 50 extends from functional section 32 to workpiece-side end 18 of honing tool 10. Tool guide 50 is designed to interact with a guide bushing and to axially align honing tool 10 when tool guide 50 is received in a corresponding guide bushing.
First honing section 36 has a group of first hone strips 52. Second honing section 38 has a group of second hone strips 54. First honing section 36 may be equipped with hone strips 52 which are designed to carry out a pre-honing. Second honing section 38 may be equipped with hone strips 54 which are designed to carry out a finishing honing.
The first honing section 36 is located on tool body 17 spaced apart from second honing section 38 in the axial direction A.
Workpiece checking element 34 is movably arranged opposite to tool body 17. Workpiece checking element 34 is arranged on tool body 17 with resilient support. For this purpose, workpiece checking element 34 is connected to tool body 17 via a plurality of coil springs 56.
Workpiece checking element 34 is preloaded (biased) to an initial position AS which corresponds to the position shown in FIG. 1. In this example, the preload is realized by coil springs 56.
Workpiece checking element 34 is arranged on tool body 17 such that workpiece checking element 34 is moved out of the initial position AS when workpiece checking element 34 comes into contact with workpiece 16.
Workpiece checking element 34 has a contact section 58 for contacting the workpiece 16. When viewed from workpiece-side end 18 of tool body 17 along the axial direction, contact section 58 expands in a radial direction R.
Workpiece checking element 34 is ring-shaped and extends around tool body 17.
Workpiece checking element 34 is located, in the axial direction A, between workpiece-side end 18 of tool body 17 and first honing section 36. However, it is also within the meaning of the invention if, for example, workpiece checking element 34 forms the workpiece-side end 18 of tool body 17.
FIG. 2 shows a sectional view along line II-II through honing tool 10. In the section plane of FIG. 2, the course of a first measuring air channel 60 can be seen. Measuring air channel 60 connects first connection 26 for measuring air with second air measuring nozzles 48 of re-measuring arrangement 46.
FIG. 3 also shows a sectional view along line II-II through honing tool 10. However, the sectional plane of FIG. 3 is offset from that of FIG. 2 in a circumferential direction U. In the sectional plane of FIG. 3, the course of a second measuring air channel 62 can be seen. Measuring air channel 62 connects second connection 28 for measuring air with first air measuring nozzles 44 of in-process measuring arrangement 42.
FIG. 3 shows that workpiece checking element 34 is coupled to a pneumatic actuator 64 or a plurality of such actuators 64 such that pneumatic actuator 64 changes a flow cross-section of a pneumatic checking medium channel 66 when the workpiece checking element is moved from the initial position AS. Checking medium channel 66 is formed by a part of measuring air channel 62. Actuator 64 is rod-shaped and projects into the region of a T-junction 68 of measuring air channel 62. If workpiece checking element 34 is moved in the direction of workpiece-far-end 20 of tool body 17, actuator element 64 moves into the region of T-crossing 68 such that T-crossing 68 is blocked. This blocking of T-junction 68 can be detected by a pressure sensor (not shown). The furcation of T-crossing 68, which can be blocked by the actuator 64, forms checking medium channel 66, the flow cross-section of which can be changed by actuator 64.
FIG. 4 also shows a sectional view along line II-II through honing tool 10. The sectional plane of FIG. 4 is, however, offset from those of FIGS. 2 and 3 in the circumferential direction U. The sectional plane of FIG. 4 shows the course of a cooling lubricant channel 70. Cooling lubricant channel 70 connects connections 30 for the cooling lubricant with outlets 72 for the cooling lubricant, wherein outlets 72 are arranged in the region of honing sections 36 and 38.
FIG. 5 also shows a sectional view along line II-II through honing tool 10. However, the sectional plane of FIG. 5 is offset from those of FIGS. 2, 3 and 4 in the circumferential direction U.
In FIG. 5 it can be seen that honing tool 10 comprises an infeed device 74 by which the respective hone strips 52, 54 of the two honing sections 36 and 38 can always be fed simultaneously in the radial direction R. Infeed device 74 is used to feed the respective hone strips 52, 54 of the two honing sections 36 and 38 at the same time.
Infeed device 74 has an infeed element 75 which has a first infeed cone 76 and a second infeed cone 78, wherein first infeed cone 76 is assigned to hone strips 52 of first honing section 36 and second infeed cone 78 is assigned to hone strips 54 of second honing section 38.
The respective infeed cones 76 and 78 are designed to interact with wedge surfaces 80 and 82 of hone strips 52 and 54, respectively, in order to convert an axial movement of infeed element 75 into a radial infeed of hone strips 52 and 54, respectively. Infeed cones 76 and 78 of both honing sections 36 and 38 are arranged on the single infeed element 75 such that both infeed cones 76 and 78 are moved when infeed element 75 moves. The movement of infeed element 75 can be controlled by actuating infeed pin 24. There is a guide pin at the lower end of the infeed element which guides the infeed element into a stable coaxial position inside the tool body.
FIG. 6 shows a sectional view along the line II-II through an alternative embodiment of a honing tool 10 according to the invention. The sectional plane of FIG. 6 corresponds to that of FIG. 2.
The embodiment shown in FIG. 6 differs from the embodiment of FIGS. 1-5 in that a further in-process measuring arrangement 84 with a corresponding air measuring nozzle 86 is arranged in second honing section 38. With the embodiment of FIG. 6, no re-measuring arrangement 46 is provided. However, a re-measuring arrangement 46 can also be provided in addition to the further in-process measuring arrangement 84.
FIGS. 7, 8 and 9 each illustrate the sequence of a method according to the invention for honing an inner surface 12 of an opening 14 in a workpiece 16 using a honing tool 10 according to the invention, which may be, for example, honing tool 10 of FIG. 1 (used in the methods according to FIGS. 7 and 8) or FIG. 6 (used in the methods according to FIG. 9). Workpiece 16 is a gear wheel. The method comprises the following steps in sequence:
Step a): axially inserting (illustrated by a corresponding arrow) honing tool 10 into opening 14 and pre-checking, in particular an opening width, of opening 14 in workpiece 16 by means of workpiece checking element 34.
During the pre-checking, workpiece checking element 34 moves into opening 14 if opening 14 has a sufficient width (i.e. if opening 14 has a nominal dimension) and correct axial alignment.
If the width of opening 14 is too small or workpiece 16 is not correctly aligned, workpiece checking element 34 contacts workpiece 16 with contact section 58 and workpiece checking element 34 is moved out of the initial position AS. Since workpiece checking element 34 is coupled to actuators 64 such that actuators 64 change the flow cross-section of pneumatic checking medium channel 66 formed by the bifurcation of T-crossing 68 (see FIG. 3) when workpiece checking element 34 is moved from the initial position AS, actuators 64 block T-crossings 68 and thus change the flow cross-section of checking medium channel 66. By changing the flow cross-section, an increase in pressure can be detected during the flow through checking medium channel 66, and the insertion operation of honing tool 10 can be interrupted.
Step b): honing the opening 14 by hone strips 52 of honing section 36 (symbolically represented by a double arrow and a curved arrow). During step b) (during or after honing) it is optionally possible to carry out a measurement of the opening width of opening 14 via an air measuring nozzle 44 of the in-process measuring arrangement 42 which is arranged adjacent to hone strips 52 of first honing section 36 when viewed in the axial direction A.
The method preferably comprises a step c): axially moving honing tool 10, in particular further axially inserting honing tool 10 into opening 14, and re-measuring the opening width via an air measuring nozzle which is spaced apart from honing section 36 of step b) in the axial direction A. This step is not shown in FIGS. 7, 8 and 9.
Preferably, the method comprises a step d): axially moving honing tool 10, in particular further axially inserting honing tool 10 into opening 14, and then honing opening 14 by hone strips 54 of second honing section 38. During step b) it is optionally possible to carry out a measurement of the opening width of opening 14 via an air measuring nozzle 86 of the in-process measuring arrangement 84 which is arranged adjacent to hone strips 54 of second honing section 38 when viewed in the axial direction A.
Preferably, the method comprises a step (e): re-measuring the opening width via an air measuring nozzle 86 which is arranged adjacent to the hone strips 54 of the second honing section 38 of step d) when viewed in the axial direction A (this alternative of the method is shown in FIGS. 7 and 8); or axially moving honing tool 10, in particular further axially inserting honing tool 10 into the opening 14, and re-measuring the opening width via an air measuring nozzle 48 which is spaced apart from second honing section 38 of step d) in the axial direction A (this alternative is shown in FIG. 9).
Preferably, the method comprises a step f): axially moving honing tool 10, in particular further axially inserting honing tool 10 into opening 14, and subsequently brushing the opening 14 by brush section 40 of honing tool 10;
g) axially retracting honing tool 10 from opening 14 (not shown).
With the method variant of FIG. 7, workpiece 16 is stationary and honing tool 10 is moved relative to workpiece 16. With the method variants shown in FIGS. 8 and 9, honing tool 10 is stationary and workpiece 16 is moved relative to honing tool 10. Both ways of generating a relative movement between honing tool 10 and workpiece 16 are in the sense of this invention.

Claims

1. A honing tool for honing an inner surface of an opening in a workpiece, comprising a tool body extending in an axial direction (A) and having a honing section which comprises a group of hone strips, characterised in that the honing tool comprises a workpiece checking element for checking a size and/or a position of the opening, the workpiece checking element being arranged on the tool body so as to be movable relative to the tool body, preferably in the axial direction (A), in order to check during the insertion of the honing tool into the opening whether the opening in the workpiece has a sufficient opening width and/or to check for a positioning or alignment error of the opening of the workpiece, wherein the workpiece checking element is biased into an initial position (AS) and is arranged on the tool body such that the workpiece checking element is moved out of the initial position (AS) when the workpiece checking element comes into contact with the workpiece, wherein the workpiece checking element is coupled to a detection device which is adapted to detect a movement of the workpiece checking element relative to the tool body, wherein the detecting device is coupled to a controller such that the controller interrupts the insertion of the honing tool into the opening if the detecting device detects a movement of the workpiece checking element relative to the tool body.

2. The honing tool according to claim 1, characterized in that the workpiece checking element is arranged resiliently supported on the tool body.

3. (canceled)

4. The honing tool according to claim 1, characterised in that the workpiece checking element comprises a contact portion for contacting the workpiece which expands in a radial direction (R) when viewed from a workpiece-side end of the tool body along the axial direction (A).

5. The honing tool according to claim 1, characterized in that the workpiece checking element is ring-shaped, and preferably extends around the tool body.

6. The honing tool according to claim 1, characterized in that the workpiece checking element is arranged in the axial direction (A) between the workpiece-side end of the tool body and the honing section, or in that the workpiece checking element forms a workpiece-side end of the tool body.

7. The honing tool according to claim 1, characterized by a second honing section comprising a second group of hone strips, wherein the first honing section is arranged on the tool body spaced apart from the second honing section in the axial direction (A).

8. The honing tool according to claim 1, characterized in that the workpiece checking element is coupled to a pneumatic or hydraulic actuator such that the pneumatic or hydraulic actuator changes a flow cross-section of a pneumatic or hydraulic checking medium channel when the workpiece checking element is moved out of the initial position (AS).

9. The honing tool according to claim 1, characterized by at least one air measuring nozzle which, when viewed in the axial direction (A), is arranged offset with respect to the hone strips, in particular, when viewed from a workpiece-side end of the tool body, behind the hone strips of one of the honing sections, preferably of all of the honing sections, and/or by at least one air measuring nozzle which, when viewed in the axial direction (A), is located adjacent to the hone strips of the honing section or of one of the honing sections, preferably wherein the honing tool comprises at least one air measuring nozzle per honing section which is arranged adjacent to the hone strips of the respective honing section when viewed in the axial direction (A).

10. The honing tool according to claim 8, characterised in that the actuator which is coupled the workpiece checking element is a pneumatic actuator and the checking medium channel whose flow cross-section is changed by the actuator, is pneumatically connected to a measuring air channel via which at least one air measuring nozzle can be supplied with measuring air.

11. The honing tool according to claim 1, characterized by an infeed device by which the respective hone strips of the two honing sections are feedable in the radial direction (R) independently of each other or always simultaneously.

12. The honing tool according to claim 11, characterized in that the infeed device has one infeed cone per honing section, which is designed to interact with wedge surfaces of the hone strips, in order to convert an axial movement of an infeed element into a radial infeed of the hone strips, preferably wherein the infeed cones of a plurality of honing sections are arranged on a single infeed element such that both infeed cones are moved upon movement of the infeed element.

13. The honing tool according to claim 1, characterized in that the honing tool comprises a brush section.

14. The honing tool according to claim 1, characterized in that a tool guide is arranged on the honing tool in the region of the workpiece-side end of the tool body.

15. A method of honing an inner surface of an opening in a workpiece with a honing tool for honing an inner surface of an opening in a workpiece, comprising a tool body extending in an axial direction (A) and having a honing section which comprises a group of hone strips, characterised in that the honing tool comprises a workpiece checking element for checking a size and/or a position of the opening, the workpiece checking element being arranged on the tool body so as to be movable relative to the tool body, preferably in the axial direction (A), in order to check during the insertion of the honing tool into the opening whether the opening in the workpiece has a sufficient opening width and/or to check for a positioning or alignment error of the opening of the workpiece, wherein the workpiece checking element is biased into an initial position (AS) and is arranged on the tool body such that the workpiece checking element is moved out of the initial position (AS) when the workpiece checking element comes into contact with the workpiece, wherein the workpiece checking element is coupled to a detection device which is adapted to detect a movement of the workpiece checking element relative to the tool body, wherein the detecting device is coupled to a controller such that the controller interrupts the insertion of the honing tool into the opening if the detecting device detects a movement of the workpiece checking element relative to the tool body, wherein the method comprises the following steps in succession:

a) axially inserting the honing tool into the opening and pre-checking, in particular of an opening width, of the opening in the workpiece by means of the workpiece checking element;

b) honing the opening by the hone strips of the honing section, preferably measuring the opening width via an air measuring nozzle;

preferably c) axially moving the honing tool, in particular further axially inserting the honing tool into the opening, and re-measuring the opening width via an air measuring nozzle which is spaced apart from the honing section of step b) in the axial direction (A);

preferably d) axially moving the honing tool in particular further axially inserting the honing tool into the opening, and subsequently honing the opening by the hone strips of the second honing section, preferably measuring the opening width via an air measuring nozzle which is arranged adjacent to the hone strips of the second honing section when viewed in the axial direction (A);

preferably e) re-measuring the opening width via an air-measuring nozzle which is arranged adjacent to the hone strips of the second honing section of step d) when viewed in the axial direction (A), or axially moving the honing tool in particular further axially inserting the honing tool into the opening, and re-measuring the opening width via an air-measuring nozzle which is spaced apart from the second honing section of step d) in the axial direction (A);

preferably f) axially moving the honing tool, in particular further axially inserting the honing tool into the opening, and subsequently brushing of the opening by the brush section of the honing tool;

g) axially retracting the honing tool from the opening.