DE102007024569A1 - Method for manufacturing boreholes in housings, involves shifting reference housing in operating condition and design form corresponding to operating form of borehole is manufactured in operating condition of reference housing - Google Patents

Abstract

The method involves shifting a reference housing in an operating condition. A design form corresponding to an operating form of a borehole is manufactured in the operating condition of the reference housing. An actual exit form (10) of the borehole is measured resulting from the design form. A design exit form is determined on the basis of the measured actual exit form. The design exit form is placed with a machining process in another housing in unloaded condition.

Description

The The invention relates to a method for producing holes in Housings, in particular cylinder bores for Reciprocating engines in cylinder crankcases, wherein the Holes in an unloaded state an initial shape and in the Operating state deviates from the initial form of operation exhibit.

Such a method is in particular from the EP 1 321 229 A1 previously known. In this known prior art, the deviation of the operating form is determined by an ideal desired shape in the operating state. From the determined deviation, the initial shape is then theoretically determined such that the resulting operating form comes very close to the desired shape. The bore is then brought by a machining process in this theoretically determined starting shape.

Of the present invention is based on the object, such a known To further develop the procedure.

This object is achieved by a method having the features of claim 1. The procedure proceeds as follows:
First, a housing is set as a reference housing in a run-like state. In this operating state similar to the operating form corresponding, in particular cylindrically designed desired shape of the bore is then made. Subsequently, the reference housing is placed in the unloaded state and the resulting from the desired shape, measured due to the displacement in the unloaded state no longer cylindrically formed actual output form of the bore. On the basis of the measured data, the likewise non-cylindrical nominal output shape is then determined and introduced by means of a processing method into further housings in the unloaded state.

Thereby, that in the invention, in particular the cylindrical formed Target shape in the operating state of the reference housing can be introduced into this, it can be ensured that the introduction of the resulting initial form in more Housing during operation leads to operating forms, which correspond to the target shape or at least come very close. In contrast to the prior art, therefore not the type of operation existing in the operational state measured, but one of the operating form corresponding target shape directly in the operation or similar state in the Housing introduced.

The Sollform can basically identical to the operating form be. Then, however, the desired shape is to be produced with identical processing steps like the operating form. Also a superfinishing, in particular a Honbearbeitung, is then required to produce the desired shape.

Around the effort of producing the desired shape in the company-like Condition of the reference housing can be reduced be that the nominal shape smaller by a Feinstbearbeitungsaufmaß than the operating form and that in determining the desired output form the finishing allowance is taken into account. The microfinance allowance is the allowance which in superfinishing, in particular during honing, is to be paid off. The microfinishing allowance is between 10 μm and 100 μm and in particular between 15 μm and 70 μm.

For the case that the nominal shape smaller by the Feinstbearbeitungsaufmaß As the operating form is, it makes sense to use a roughing and subsequent finishing process in the housing contribute. In the event that the desired shape also the Fine machining includes, in addition, a honing process Find application, in particular for the production of a cylindrical Shape. The deviations from an exact cylinder are advantageously in the range of less than 7 μm.

The Thermal expansion in particular can either be measured and / or theoretically, in particular computer-aided, determined become. It is advantageous if the housing by heating and / or by static compression in the plant-like Condition is shifted. The heating of the housing to a temperature that corresponds to the operating temperature can in particular by targeted heating of the housing be achieved. The static compression can in particular by Screwing the housing with a machining permit Cover done. The lid can be used in particular as a processing goggles be educated.

There usually the bore in the initial form to show a certain manufacturing scale has that at different temperatures of the case in the operating state and in the unloaded state of the desired output form to differentiate a thermal expansion, can in determining the desired output form, the thermal expansion or Heat shrinkage of the housing considered become.

When determining the desired output form, a deviation from the operating state to the actual operating state can be taken into account, insofar as there is a deviation. In particular, a dynamic behavior of the Housing in the operating state, especially when the housing is designed as a cylinder crankcase of a reciprocating engine, are taken into account. The dynamic behavior can be determined in particular computer-aided.

The Measuring the actual output form is preferably via a coordinate measuring machine that produces a three-dimensional image the actual output form provides.

The Processing method for introducing the desired output form in the further housing can in particular a spindling and include a subsequent Formhonen. The unwinding in turn, preferably includes a roughing and a subsequent finishing processing. Roughing and the finishing can be particularly cylindrical respectively. The runout of the desired output form can then exclusively be provided by the shaping. However, this is for this a relatively high Honaufmaß in the range of 50 microns up to 70 μm required.

on the other hand can also be provided that the roughing cylindrical and the finishing is done out of round. This has the advantage that the honing allowance is much lower, especially in the Range of 15 microns to 30 microns to precipitate. For non-round finishing machining, in particular an adaptive Tool, an interpolating tool, a hydraulic room tool and / or a circular Ausspindelverfahren find use.

The Form honing is done in particular by freely controllable in the room honing stones.

Further Advantages and advantageous embodiments of the invention are the following description, based on which in the figures illustrated embodiments of the invention in more detail are described and explained.

there demonstrate:

1 The initial shape of a bore in the unloaded state,

2 the resulting from the initial form operating mode in the operating condition, and

3 various steps of the method according to the invention.

In the 1 is one in one in the 1 not shown housing introduced bore shown in the unloaded state in the 1 shown starting form 10 having. The bore is a cylinder bore of a reciprocating engine in a cylinder crankcase. If the cylinder crankcase is placed in the operating state, that is, the housing is statically braced, brought to operating temperature in the range of approximately 90 ° to 110 ° and in particular still charged dynamically, then results in the 2 illustrated operating form 12 the bore. It can be clearly seen that the operating form has large deviations from the ideal cylindrical shape. The larger the deviation of the operating mode from the ideal cylinder shape, the higher the oil emission into the combustion chamber, which leads to poorer exhaust gas values, increased wear and oil consumption.

In order to achieve the best possible cylindrical operating form of the bore in the operating state, as follows in the 3 described procedure.

A reference housing 14 is with cylinder bores 16 Mistake. The reference housing 14 is then put into a similar state. On the one hand, it will be done with a first as editing glasses 18 screwed formed lid. The editing glasses 18 is designed so that on the one hand, a screw according to a later to be provided cylinder head cover and on the other hand, a machining of the holes 16 still possible. On the other hand, it is brought to the operating temperature.

After the reference housing 14 is placed in the operation-like state, the holes of the operating form corresponding desired shape are processed. In particular, the desired shape can be designed to be smaller than the operating form by a superficial machining allowance differing from the operating form. This eliminates processing costs in the production of the desired shapes. On the other hand, it is conceivable that the desired shape is identical to the operating form. Then, however, a superfinishing is required.

Then the editing glasses 18 removed and the reference housing 14 in the unloaded and in particular cooled to room temperature state.

In This condition is the resulting from the cylindrical nominal shape measured non-cylindrical actual output form of the bore.

From the measured actual output form, the desired output shape can then be determined. If the desired shape of the bore around the superfine machining allowance is smaller than the operating mode to be provided, this must be taken into account when determining the desired starting shape. In addition, the temperature influence can be considered. Furthermore, the dynamic behavior of the housing 14 operational the reciprocating engine determined and taken into account in the calculation of the desired output form.

Around to a specified production dimension d1 of the bore in the unloaded State, in particular, initially the desired shape the bore in the operation-like state with such Production dimension d1, for example, be 81.925 mm can be produced. Due to the cooling of the housing in the unloaded state results in an actual output form with a Dimension d2, which is smaller than the production dimension d1. The temperature influence can therefore be with Δd = calculate d1 - d2. The influence of temperature can also be simulated are calculated and compared with the measured Δd.

Around arrive at the production dimension d1 in the unloaded state, may be a re-machining of the hole in the plant-like Condition, but with a production dimension d3, resulting from the production dimension d1 plus the Dimension Δd gives: d3 = d1 + Δd. Thereby should be achieved that in the unloaded state, an actual output form with the correct nominal diameters.

After this the desired output form based on the measured actual output form was calculated, the target output form can be standard in further, in the unloaded condition located crankshaft housing, be introduced. The introduction takes place with a processing method, in particular a spindling with a roughing and a subsequent finishing treatment comprises. Roughing and the finishing can be done in each case cylindrical. It is also conceivable that the finishing treatment is out of round. The Superfinishing is then carried out by shaping, in particular by means of a freewheel controllable in the room.

QUOTES INCLUDE IN THE DESCRIPTION

This list The documents listed by the applicant have been automated generated and is solely for better information recorded by the reader. The list is not part of the German Patent or utility model application. The DPMA takes over no liability for any errors or omissions.

Cited patent literature

• - EP 1321229 A1 [0002]

Claims (13)

Method for producing bores ( 16 ) in housings ( 14 ), in particular of cylinder bores for reciprocating engines in cylinder crankcases, wherein the holes in an unloaded state have an output form and in the operating state deviating from the starting form operating mode, characterized by the following method steps: a) Staggering of a reference housing in a run-like state, b) producing one of C) offset of the reference housing in the unloaded state, d) measuring the resulting from the desired shape actual output form of the bore, e) determining the desired output form based on the measured actual output form , and f) introducing the desired output shape with a machining process into further housings in the unloaded state. Method according to claim 1, characterized that the desired shape according to step b) identical to is the operating form and that in step e) the actual output form identical to the desired output form. Method according to claim 1, characterized that the desired shape according to step b) smaller by a Feinstbearbeitungsaufmaß than the operating form and that in determining the desired output form in step e) takes account of the microfinishing allowance becomes. Method according to claim 1, 2 or 3, characterized that the desired shape in step b) by means of a roughing and finishing process is introduced into the housing. Method according to at least one of the preceding Claims, characterized in that in the determination the desired output form in step e) a thermal expansion or heat shrinkage of the housing considered becomes. Method according to at least one of the preceding Claims, characterized in that the housing in step a) by heating and / or by static Pressing is placed in the operating-like state. Method according to at least one of the preceding Claims, characterized in that in the determination the desired output form in step e) a deviation from the operating state is taken into account for the operating state. Method according to at least one of the preceding claims, characterized in that the measuring according to step d) by means of a coordinate measuring machine ( 20 ) he follows. Method according to at least one of the preceding Claims, characterized in that the processing method according to step f) a spin-off and a subsequent Formhonen includes. Method according to claim 9, characterized in that that the unwinding a roughing and a subsequent Finishing includes. Method according to claim 10, characterized in that that roughing and finishing are more cylindrical respectively. Method according to claim 10, characterized in that that roughing cylindrical and finishing out of round Method according to one of claims 9 to 12, characterized in that the form honing freely controllable in space Honing stones find use.