MEASURING DEVICE FOR MEASURING THE SPACE OF TWO SELECTED POINTS

Abstract

A shaping machine or a handling apparatus for a shaping machine comprising at least one measuring device for measuring the spacing of two selected points of the shaping machine or the handling apparatus, wherein the at least one measuring device has at least one piezoresistive micromechanical sensor.

Claims

1. A shaping machine or handling apparatus for a shaping machine comprising at least one measuring device for measuring the spacing of two selected points of the shaping machine or the handling apparatus, wherein the at least one measuring device has at least one piezoresistive micromechanical sensor.

2. The shaping machine or handling apparatus as set forth in claim 1, wherein the piezoresistive micromechanical sensor is connected to the shaping machine or the handling apparatus by way of a measurement body.

3. The shaping machine or handling apparatus as set forth in claim 2, wherein the measurement body has at least one first component which is stationary relative to one of the selected points and at least one second component which is movable relative to the first component and which is stationary relative to the other of the selected points, wherein a movement, preferably a displacement, of the at least one first component relative to the at least one second component along a measurement direction device can be measured by the piezoresistive micromechanical sensor and can be provided by the sensor as a measurement signal.

4. The shaping machine or handling apparatus as set forth in claim 3, wherein the measurement body has a guide device for the at least one first component and/or the at least one second component.

5. The shaping machine or handling apparatus as set forth in claim 4, wherein the guide device is connected to the at least one first component and/or the at least one second component by way of flexural hinges.

6. The shaping machine or handling apparatus as set forth in claim 5, wherein the guide device is in the form of a frame which at least partially surrounds the first component and/or the at least one second component.

7. The shaping machine or handling apparatus as set forth in claim 2, wherein the measurement body is of a mirror-symmetrical configuration around an axis of symmetry extending in orthogonal relationship with the measurement direction.

8. The shaping machine or handling apparatus as set forth in claim 2, wherein the measurement body is of a thermosymmetrical structure.

9. The shaping machine or handling apparatus as set forth in claim 2, wherein in addition to the piezoresistive micromechanical sensor there is provided at least one temperature sensor which is preferably arranged in the at least one measuring device, particularly preferably on the measurement body.

10. The shaping machine or handling apparatus as set forth in claim 9, wherein the signals of the at least one temperature sensor can be fed to a microcontroller for the compensation of thermally induced displacements of the measurement body.

11. The shaping machine or handling apparatus as set forth in claim 10, wherein the microcontroller is integrated into the at least one measuring device, preferably the measurement body.

12. The shaping machine or handling apparatus as set forth in claim 2, wherein the piezoresistive micromechanical sensor is secured to the measurement body in biased relationship with an adjustable biasing.

13. The shaping machine as set forth in claim 1, wherein the measuring device is part of an injection unit, preferably a material barrel, of the shaping machine and the measuring device is configured to determine an injection force of the injection unit from the measurement signal provided by the piezoresistive micromechanical sensor.

14. The shaping machine as set forth in claim 1, wherein the measuring device is part of a closing unit of the shaping machine and the measuring device is configured to determine a closing force of the closing unit from the measurement signal provided by the piezoresistive micromechanical sensor.

15. The handling apparatus as set forth in claim 1, wherein the measuring device is arranged on a movable arm of the handling apparatus and the measuring device is configured to determine an acceleration of the arm from the measurement signal provided by the piezoresistive micromechanical sensor.

16. The shaping machine as set forth in claim 1, wherein the shaping machine is in the form of an injection molding machine, preferably a plastic injection molding machine.

Description

BRIEF DESCRIPTION OF THE DRAWINGS

[0044] Details of the invention are discussed hereinafter with reference to the Figures, in which:

[0045] FIG. 1 shows a shaping machine according to the invention,

[0046] FIG. 2 shows a handling apparatus according to the invention,

[0047] FIGS. 3a and 3b are a plan view and a sectional view, respectively, of a measurement body without a piezoresistive micromechanical sensor,

[0048] FIGS. 4a and 4b are a plan view and a sectional view, respectively, of an alternative configuration of a measurement body without piezoresistive micromechanical sensor,

[0049] FIG. 5 shows an adjusting device, and

[0050] FIG. 6 shows the measurement body shown in FIG. 3 with a piezoresistive micromechanical sensor.

DETAILED DESCRIPTION OF THE INVENTION

[0051] FIGS. 1 and 2 show a shaping machine 1 according to the invention and a handling apparatus 2 according to the invention, wherein different possible positions of the measuring device 3 are shown there.

[0052] With reference to FIG. 1 the arrangement includes more specifically: [0053] a measuring device 3 at a first position 3.1 for measuring an injection force, [0054] measuring devices 3 at second positions 3.2 for measuring an instantaneous internal pressure in a plastic melt in a plasticising cylinder of the shaping machine, [0055] measuring devices 3 at third positions 3.3 for measuring a beam member stretch and/or a closing force distribution, [0056] a measuring device 3 at a fourth position 3.4 for measuring a closing force, [0057] a measuring device 3 at a fifth position 3.5 for measuring a pressing force and/or a hot runner discharge, and [0058] a measuring device 3 at a sixth position 3.6 for measuring the tool to-and-fro movement.

[0059] FIG. 3a shows a measurement body 5 without piezoresistive micromechanical sensor 4. The measurement body 5 is of a mirror-image symmetrical configuration around an axis of symmetry S and has a first component 51 and a second component 52 which are guided by a guide device 53 in the form of a frame surrounding the two components 51, 52, along the measurement direction M.

[0060] In this example the first component 51 is arranged by way of the bore 55 stationarily relative to a selected point A and the second component 52 is arranged by way of the bore 56 stationarily relative to the other selected point B.

[0061] The piezoresistive micromechanical sensor 4 which is still to be fitted in place measures the movement of the two edges 57, 58 (that is to say the size of the gap 59 which is formed by the edges 57, 58 and which here for example is 1 millimeter) and outputs same as a measurement signal.

[0062] The guide device 53 is connected to the first component 51 by way of here four flexural hinges 54 and to the second component 52 by way of here four flexural hinges 54. They have two material weakenings along their extent in a direction in orthogonal relationship with the measurement direction M, thereby respectively providing two hinge locations so that movement of the first and second components 51, 52 in another direction than the measurement direction M is prevented.

[0063] FIG. 3b shows a section along line A-A shown in FIG. 3a.

[0064] An alternative configuration of the measurement body 5 is shown in FIG. 4a. This does not involve a configuration of mirror-image symmetrical nature. FIG. 4b shows a section along the line B-B shown in FIG. 4a.

[0065] FIG. 5 shows a possible configuration of an adjusting device 6 for the piezoresistive micromechanical sensor 4.

[0066] This serves to secure the piezoresistive micromechanical sensor 4 to the measurement body 5 in a biased condition with an adjustable biasing preloading. By virtue of the selection of the preloading the piezoresistive micromechanical sensor 4 can be mounted to the measurement body 5 with a neutral position different from the unloaded state, and thus in operation can provide measurement signals in and in opposite relationship to the measurement direction M.

[0067] By way of example the measurement body 5 shown in FIGS. 3a, b can be fixed with its second component 52 by way of the bore 56 in the bore 61 or 62 (depending on the respective size of the bore 56). Then the first component 51 can be positioned as desired by way of the bore 55 in the slot 63 and fixed. Depending on the respective positioning of the bore 55 in the slot 63 the size of the gap 59 changes. The piezoresistive micromechanical sensor 4 is then connected in the region of the gap 59 to the first component 51 and the second component 52 (for example using an adhesive connection). Now the measurement body 5 together with the piezoresistive micromechanical 4 can be removed from the adjusting device 6 and is ready for operation (see FIG. 6).

LIST OF REFERENCES

[0068] 1 shaping machine [0069] 2 handling apparatus [0070] 3 measuring device [0071] 3.1 first position of a measuring device [0072] 3.2 second position of a measuring device [0073] 3.3 third position of a measuring device [0074] 3.4 fourth position of a measuring device [0075] 3.5 fifth position of a measuring device [0076] 3.6 sixth position of a measuring device [0077] 4 piezoresistive micromechanical sensor [0078] 5 measurement body [0079] 51 first component of the measurement body [0080] 52 second component of the measurement body [0081] 53 guide device of the measurement body [0082] 54 flexural hinge of the measurement body [0083] 55 bore in the first component [0084] 56 bore in the second component [0085] 57 edge of the first component [0086] 58 edge of the second component [0087] 59 gap between the edge of the first component and the edge of the second component [0088] 6 adjusting device for the piezoresistive micromechanical sensor [0089] 61 bore [0090] 62 bore [0091] 63 slot [0092] A, B selected points [0093] M measurement direction [0094] S axis of symmetry