METHOD FOR PRODUCING A SENSOR DEVICE AND COMPONENT AND/OR CHASSIS COMPONENT COMPRISING A SENSOR DEVICE OF THIS KIND

Abstract

A method for producing a sensor device (2) for the measurement of an instantaneous load on a component (1, 15), in which the component (1, 15) is made of plastic, in which a sensor layer (3) is arranged in the component (1, 15). The sensor layer (3) is formed of a carrier material with electrically conductive particles embedded therein. To be able to measure or determine loads and/or forces in the component (1, 15) in a better an/or more reliable way, the method includes forming at least one blind hole-like recess (4) in the component (1, 15) to receive the sensor layer (3).

Claims

1-10. (canceled)

11. A method for producing a sensor device (2) for measurement of an instantaneous load on a component (1, 15), in which the component (1, 15) is made of plastic and a sensor layer (3) is arranged in the component (1, 15), the method comprising: forming the sensor layer (3) with a carrier material having electrically conductive particles embedded therein, and forming at least one blind hole-like recess (4) in the component (1, 15) which receives the sensor layer (3).

12. The method according to claim 11, further comprising at least partially filling the blind hole-like recess (4), under an effect of at least one of gravity or capillary action, with the carrier material in the form of a liquid with the electrically conductive particles embedded therein, and a paint is used as the carrier material.

13. The method according to claim 12, further comprising, after at least partial filling of the blind hole-like recess (4), at least one of hardening and curing the carrier material with the electrically conductive particles.

14. The method according to claim 11, further comprising embedding at least two electrically conducting sections (5, 6) in the component (1, 15) in order to provide contact points (7, 8) for the sensor layer (3), and during the production of the component (1, 15), and partially overmolding and/or over-injecting the electrically conducting sections (5, 6) with the plastic of the component (1, 15).

15. The method according to claim 14, further comprising electrically connecting the contact points (7, 8) provided by the electrically conducting sections (5, 6) to one another by way of the sensor layer (3), and using either stamped grids or wires for the electrically conducting sections (5, 6).

16. The method according to claim 15, further comprising spacing the contact points (7, 8) a distance apart from one another, in a longitudinal direction of the blind hole-like recess (4), and at least partially filling the blind hole-like recess (4) with the carrier material with the electrically conductive particles at least until the contact points (7, 8) are in contact with at least one of the carrier material and the electrically conductive particles embedded therein.

17. The method according to claim 11, further comprising connecting the sensor device (2) to an evaluation unit (12) which determines an instantaneous load on the component (1, 15) from electrical resistance measurements in the sensor layer (3).

18. The method according to claim 11, further comprising arranging a plurality of blind hole-like recesses (4) in the component (1, 15) for receiving a sensor layer (3) in each case.

19. The method according to claim 11, further comprising forming the component (1, 15) as at least one of a chassis component for a vehicle, a ball socket and a joint housing for a ball joint (16).

20. A component and/or chassis component produced in accordance with the method according to claim 11, wherein the sensor layer (3) is held in the at least one blind hole-like recess (4).

21. A method of producing a sensor device which measures an instantaneous load on a component made of plastic, the method comprising: at least partially overmolding first and second electrically conducting sections, when forming the component, such that the first and the second electrically conducting sections are at least partially embedded within the component; forming a blind hole-like recess in the component such that an end of each of the first and the second electrically conducting sections is open to the blind hole-like recess; embedding electrically conductive particles within a liquid carrier material; at least partially filling the blind hole-like recess with the liquid carrier material such that the end of each of the first and the second electrically conducting sections contacting the liquid carrier material; and at least one of hardening and curing the liquid carrier material to form a sensor layer within the component.

Description

BRIEF DESCRIPTION OF THE DRAWINGS

[0020] Below, the invention is explained in greater detail with reference to the figures. In these, the same indexes denote the same, similar or functionally equivalent components or elements. The figures show:

[0021] FIG. 1: A sectional schematic side view of a component according to the invention, and

[0022] FIG. 2: A sectional schematic side view of a chassis component according to the invention.

DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS

[0023] FIG. 1 shows a sectional schematic side view of a component 1 according to the invention. The component 1 is made of plastic. The component 1 has a sensor device 2. The sensor device 2 comprises a sensor layer 3. The sensor layer 3 is formed by a carrier material with electrically conductive particles embedded in it, which are not shown is detail here. In this example embodiment, the electrically conductive particles are in the form of carbon nano-tubes.

[0024] The component 1 has a blind hole-like recess 4. The blind hole-like recess 4 extends like a shaft into the component 1. The sensor layer 3 is located inside the blind hole-like recess 4. In this example embodiment the blind hole-like recess 4 is only partially filled or topped up with the sensor layer 3. Alternatively, the blind hole-like recess 4 can also be completely filled or topped up with the sensor layer 3.

[0025] The sensor device 2 comprises two electrically conducting sections 5, 6. The two electrically conducting sections 5, 6 are essentially embedded in the component 1. Here, the electrically conducting sections 5, 6 form contact points 7, 8 for the sensor layer 3. For that, the two contact points 7, 8 are electrically connected to the sensor layer 3. The electrically conducting sections 5, 6 can be in the form of stamped grids. A first contact point 7, in particular of the first electrically conducting section 5, is arranged close to the bottom 9 of the blind hole-like recess 4, on an internal surface 10 of the blind hole-like recess 4. A second contact point 8, in particular of the second electrically conducting section 6, is arranged close to an opening 11 of the blind hole-like recess 4 on the internal surface 10. The ends of the electrically conducting sections 5, 6 remote from the contact points 7, 8 are connected to an evaluation unit 12.

[0026] To produce the component 1 with the sensor device 2, first the electrically conducting sections 5, 6, for example in the form of stamped grids, are arranged in an injection-molding die (not shown). Then the component 1 is made from a plastic. During this the electrically conducting sections 5, 6 are at the same time partially overmolded or over-injected by the plastic of the component 1. During the production of the component 1 the blind hole-like recess 4 can be made at the same time. Alternatively, the blind hole-like recess 4 can be produced after the component 1 has been made, by drilling a bore.

[0027] Thereafter, the blind hole-like recess 4 is partially or completely filled or topped up with a liquid carrier material in which the electrically conductive particles are embedded. During this it is important that as much carrier material is filled into the blind hole-like recess 4 as is needed to make contact with both the contact point 7 and with the contact point 8 of the two electrically conducting sections 5, 6. On the other hand, how far the blind hole-like recess 4 is filled beyond that is not relevant for the function of the sensor device 2.

[0028] In this example embodiment, the liquid carrier material is in the form of a paint with embedded electrically conductive particles. The carrier material can be filled into the opening 11 in the blind hole-like recess 4 the under the effect of gravity and/or capillary action. Thereafter, the carrier material hardens and/or is actively cured so as to form the sensor layer 3.

[0029] Finally, the ends of the electrically conducting sections 5, 6 remote from the contact points 7, 8 are connected to the evaluation unit 12. From electrical resistance measurements in the sensor layer 3, an instantaneous load and/or action of force on the component 1 can be determined by the evaluation unit 12. With a load or force action which, as indicated by the arrow 13, is directed transversely or perpendicularly to the longitudinal extension of the sensor layer 3 or the blind hole-like recess 4, as shown by the arrow 14 there is an extension or stretching of the sensor layer 3. This also results in an extension or stretching of the electrically conductive particles, which results in a change of the resistance of the sensor layer 3. In the case of a decreasing load on the component 1, for example directed oppositely to the arrow 13, i.e. transversely or perpendicularly to the length of the sensor layer 3 and directed away from it, the sensor layer 3 contracts again. Thereby the electrically conductive particles in the sensor layer 3 become shorter and this in turn results in a change of the electrical resistance of the sensor layer 3.

[0030] FIG. 2 shows a sectional schematic side view of a chassis component 15 according to the invention. In this example embodiment the component 15 is a ball socket for a ball joint 16, which in this case is only indicated schematically. The ball joint 16 comprises a joint ball 17, which is fitted into the ball socket 15 so that it can move.

[0031] The ball socket 15 has a sensor device 2, which is essentially formed as in the representation in FIG. 1. Accordingly, reference should also be made to the preceding description.

[0032] During the use of the ball joint 16, various loads and/or forces act on the ball socket 15 by way of the joint ball 17. Here, the varying loads and/or forces directed transversely or perpendicularly to the longitudinal extension of the sensor device 2, for example as indicated by the arrow 14, bring about an extension or contraction of the sensor layer 3 as indicated by the arrow 14. The resulting resistance changes of the sensor layer 3 are measured, whereby the loads and/or forces acting are determined by means of the evaluation unit 12.

[0033] The ball socket 15 can have a plurality of blind hole-like recesses 4, each with a sensor layer 3. The several blind hole-like recesses 4 or sensor layers 3 can be distributed uniformly around the joint ball 17. In this case two or more of the blind hole-like recesses 4 or sensor layers 3 can be directed transversely or perpendicularly to one another with regard to their respective length. This enables a better position-related and/or direction-related determination of the loads and/or forces that are acting.

INDEXES

[0034] 1 Component

[0035] 2 Sensor device

[0036] 3 Sensor layer

[0037] 4 Blind hole-like recess

[0038] 5 Electrically conducting section

[0039] 6 Electrically conducting section

[0040] 7 Contact point

[0041] 8 Contact point

[0042] 9 Bottom

[0043] 10 Inner circumferential surface

[0044] 11 Opening

[0045] 12 Evaluation unit

[0046] 13 Arrow

[0047] 14 Arrow

[0048] 15 Chassis component/ball socket

[0049] 16 Ball joint

[0050] 17 Joint ball