PROCESS FOR PRODUCING A MULTI-COMPONENT WIPER ARM

• US 20110113582A1
• Filed: 10/29/2010
• Published: 05/19/2011
• Est. Priority Date: 10/29/2009
• Status: Active Grant

• Current Assignee: Robert Bosch GmbH
• Original Assignee: Robert Bosch GmbH
• Inventors: Kruse, Michael, Geise, Stephan
• Granted Patent: US 8,745,812 B2
• Time in Patent Office: Days
• US Class Current: 15/250.32
• CPC Class Codes: B60S 1/34 Wiper arms; Mountings therefor wiper arms provided with liquid spreading means B60S1/522; with gas spreading means B60S1/544
• CPC Class Codes: B60S 1/3801 characterised by a blade support harness consisting of several articulated elements B60S1/3803, B60S1/3806 take precedence
• CPC Class Codes: B60S 1/4064 the channel-shaped end being provided with protrusions on, or holes in, the side walls to create a pivot
• CPC Class Codes: B60S 2001/3898 method for manufacturing wiper blades

Abstract

The present invention relates to a process for producing a wiper arm for a window wiper device for a motor vehicle, with an upper arm portion, on which a mount is provided, in order to fix the wiper arm detachably to a wiper drive of the window wiper device, and a lower arm portion, which is pivotably connected to the upper arm portion, as well as at least one wiper blade holder which is pivotably connected to the lower arm portion, characterized by producing the wiper arm in a multi-component injection-molding process in which, in a first process step, the upper arm portion is injection-molded along with at least one first pivot pin formed on it by means of a first material component in a partial portion of a cavity, in a second process step the lower arm portion, pivotably connected to the upper arm portion, is injection-molded along with at least one second pivot pin formed on it by means of a second material component in a second partial portion of the cavity by encapsulation of the first pivot pin, and in a further process step at least one wiper blade holder is injection-molded by means of a third material component in a further partial portion of the cavity by encapsulation of the second pivot pin.

Claims

1. A process for producing a wiper arm (1) for a window wiper device for a motor vehicle, with an upper arm portion (2), on which a mount (7) is provided, in order to fix the wiper arm (1) detachably to a wiper drive of the window wiper device, and a lower arm portion (3), which is pivotably connected to the upper arm portion (2), as well as at least one wiper blade holder (5), which is pivotably connected to the lower arm portion (3), characterized by producing the wiper arm (1) in a multi-component injection-molding process in which, in a first process step, the upper arm portion (2) is injection-molded along with at least one first pivot pin (4) formed on it by means of a first material component in a partial portion of a cavity, in a second process step the lower arm portion (3), pivotably connected to the upper arm portion (2), is injection-molded along with at least one second pivot pin (6) formed on it by means of a second material component in a second partial portion of the cavity by encapsulation of the first pivot pin (4), and in a further process step at least one wiper blade holder (5) is injection-molded by means of a third material component in a further partial portion of the cavity by encapsulation of the second pivot pin (6).

2. A process for producing a wiper arm (1) according to claim 1, characterized in that, for the production of the upper arm portion (2), in a first process step a first material component, in particular a first thermoplastic material, is injected into a first partial portion of the cavity, subsequently a further part of the cavity is freed for the production of the lower arm portion (3) by means of a second material component that is different from the first material component, in particular a second thermoplastic material, the already injection-molded upper arm portion (2) forming at least part of a delimitation of the partial portion of the cavity that is to be used for the injection-molding of the lower arm portion (3) for the production of the lower arm portion (3).

3. A process for producing a wiper arm (1) according to claim 1, characterized in that, in the second process step, the pivot pin (4) of the upper arm portion (2) is encapsulated at least partially with the second material component during the injection-molding in such a way that a movable connection between the upper arm portion (2) and the lower arm portion (3) is obtained at the pivot pins (4).

4. A process for producing a wiper arm (1) according to claim 1, characterized in that, in a third process step, at least one wiper blade holder (5) is produced by injection-molding a third material component, in particular a thermoplastic material, the lower arm portion (3) forming at least part of a delimitation of the partial portion of the cavity that is used for the injection-molding of the wiper blade holder (5), and the pivot pin (6) of the lower arm portion thereby being encapsulated at least partially with the third material component in such a way that a movable connection between the lower arm portion (3) and the wiper blade holder (5) is obtained.

5. A process for producing a wiper arm (1) according to claim 1, characterized in that the same material component, in particular the same thermoplastic material, is used for the production of the upper arm portion (2) and for the production of the wiper blade holder (5), the thermoplastic material of the upper arm portion (2) and the wiper blade holder (5) being made to match the thermoplastic material of the lower arm portion (3) in such a way that the two different types of plastic do not bond to each other.

6. A process for producing a wiper arm (1) according to claim 1, characterized in that the first and second plastics have different shrinkage behaviors, the shrinkage behavior of the plastics being chosen such that a movable connection between the pivot pin (4) of the upper arm portion (2) and the lower arm portion (3) as well as the pivot pin (6) of the lower arm portion (3) and the wiper blade holder (5) is obtained.

10. A process for producing a wiper arm (1) according to claim 2, characterized in that, in the second process step, the pivot pin (4) of the upper arm portion (2) is encapsulated at least partially with the second material component during the injection-molding in such a way that a movable connection between the upper arm portion (2) and the lower arm portion (3) is obtained at the pivot pins (4).

11. A process for producing a wiper arm (1) according to claim 10, characterized in that, in a third process step, at least one wiper blade holder (5) is produced by injection-molding a third material component, in particular a thermoplastic material, the lower arm portion (3) forming at least part of a delimitation of the partial portion of the cavity that is used for the injection-molding of the wiper blade holder (5), and the pivot pin (6) of the lower arm portion thereby being encapsulated at least partially with the third material component in such a way that a movable connection between the lower arm portion (3) and the wiper blade holder (5) is obtained.

12. A process for producing a wiper arm (1) according to claim 11, characterized in that the same material component, in particular the same thermoplastic material, is used for the production of the upper arm portion (2) and for the production of the wiper blade holder (5), the thermoplastic material of the upper arm portion (2) and the wiper blade holder (5) being made to match the thermoplastic material of the lower arm portion (3) in such a way that the two different types of plastic do not bond to each other.

13. A process for producing a wiper arm (1) according to claim 12, characterized in that the first and second plastics have different shrinkage behaviors, the shrinkage behavior of the plastics being chosen such that a movable connection between the pivot pin (4) of the upper arm portion (2) and the lower arm portion (3) as well as the pivot pin (6) of the lower arm portion (3) and the wiper blade holder (5) is obtained.

7. A wiper arm (1) for a window wiper device of a motor vehicle, with an upper arm portion (2), a lower arm portion (3) and at least one wiper blade holder (5), the upper arm portion (2) being pivotably connected to the lower arm portion (3) and the lower arm portion (3) being pivotably connected to the wiper blade holder (5), and with at least one mount (7), formed on the upper arm portion (2), for the detachable fixing of the wiper arm (1) to the window wiper device, characterized in that the upper arm portion (2) and the lower arm portion (3) as well as the wiper blade holder (5) are produced by means of a multi-component assembly injection-molding process.

8. A wiper arm (1) according to claim 7, characterized in that the upper arm portion (2) and the lower arm portion (3) and/or the wiper blade holder (5) are formed from different types of thermoplastic materials, the plastics being chosen such that they do not bond to each other during or after the injection-molding.

9. A wiper arm (1) according to claim 7, characterized in that the plastics have different shrinkage properties, which are chosen such that a previously specified clearance of a fit and/or a width of a gap is/are obtained in the pivoted connections between the upper arm portion (2) and the lower arm portion (3) and/or the lower arm portion (3) and the wiper blade holder (5).

14. A wiper arm (1) according to claim 8, characterized in that the plastics have different shrinkage properties, which are chosen such that a previously specified clearance of a fit and/or a width of a gap is/are obtained in the pivoted connections between the upper arm portion (2) and the lower arm portion (3) and/or the lower arm portion (3) and the wiper blade holder (5).