CN108472847B

CN108472847B - Device and method for producing wiper rubber by means of an injection molding process

Info

Publication number: CN108472847B
Application number: CN201780006495.0A
Authority: CN
Inventors: P.科林
Original assignee: Robert Bosch GmbH
Current assignee: Robert Bosch GmbH
Priority date: 2016-01-13
Filing date: 2017-01-02
Publication date: 2021-01-01
Anticipated expiration: 2037-01-02
Also published as: JP6840153B2; WO2017121651A1; CN108472847A; DE102016200298A1; FR3046562B1; JP2019501804A; FR3046562A1

Abstract

The invention relates to a device for producing wiper rubber, comprising an injection molding tool (10) having an upper part (20) and a lower part (40), wherein at least one cavity (21, 41) is formed in the upper part (20) and/or in the lower part (40) for receiving a molding compound. At least one recess (22, 42) is formed in the upper part (20) and/or in the lower part (40), said recess adjoining the at least one cavity (21, 41), and an insert (30, 50) is arranged in the at least one recess (22, 42), said insert being movable relative to the upper part (20) and/or the lower part (40). The invention also relates to a method for producing a wiper rubber using a device according to the invention, comprising the following steps: -closing the injection tool (10), whereby pressing the insert (30, 50) in a direction towards the cavity (21, 41) adjoining the recess (22, 42), -injecting moulding material into the cavity (21, 41), -opening the injection tool (10), -removing the wiper rubber.

Description

Device and method for producing wiper rubber by means of an injection molding process

Technical Field

The invention relates to a device for producing wiper rubber, comprising an injection molding tool having an upper part and a lower part, wherein at least one cavity for receiving a molding compound is formed in the upper part and/or in the lower part. The invention also relates to a method for producing a wiper rubber using the device according to the invention.

Background

Various methods are known from the prior art for producing wiper rubbers, in particular for motor vehicles. For example, the wiper rubber can be produced in an injection molding tool. Such an injection molding tool comprises an upper part and a lower part, each having a cavity for receiving molding material. In the production of the wiper rubber, the upper part and the lower part are placed on top of each other. In this case, a negative contour is produced by the cavity between the upper part and the lower part, said negative contour having the shape of the wiper rubber. Then, a molding material is injected into the cavity, which completely fills the cavity and thus also the negative profile. After the hardening of the molding material, the injection molding tool is opened and the produced wiper rubber is removed from the cavity.

Document EP 1050442 a1 discloses a method for manufacturing a wiper blade. In this case, a plurality of associated wiper blades are first produced and are separated from one another by cuts at the edges, wherein a plurality of individual wiper blades are produced by separation. In this case, the associated wiper blade can be produced in different ways. Mention is made, inter alia, of injection moulding processes and moulding processes.

DE 102009001043 a1 discloses a wiper blade for a windshield wiper and a method for producing the same. The wiper blade comprises a wiper rubber made of an elastomer material, which surrounds a textile insert. The production of the wiper blade or wiper rubber is carried out by pressing with a tool of a press.

Document EP 1288089 a2 discloses a wiper blade and a method for producing the wiper blade. Here, the rubber profile is first produced by extrusion and is thereafter compressed, i.e. pressed, in the transverse direction. Subsequently, the profile is coated with a polymer layer, which produces sharp edges.

Document DE 102012209953 a1 discloses a method for producing wiper strips. In this case, a double strand is first extruded in an extruder, which is subsequently divided into two individual strands by cutting. In this case, the mentioned double strand is cut off in the region of the trailing wiping edge.

Disclosure of Invention

An apparatus for producing wiper rubber is proposed, which comprises an injection molding tool having an upper part and a lower part. At least one cavity is formed in the upper part and/or in the lower part, said cavity being intended to receive a molding compound.

Preferably, at least one cavity is formed in each of the upper part and the lower part. In particular, a plurality of cavities are preferably formed in each case in the upper part and in the lower part. In this case, the cavities are arranged in the upper part and in the lower part in such a way that the cavities in the upper part and in the lower part each have the contour of the wiper rubber to be produced.

According to the invention, at least one recess is formed in the upper part and/or in the lower part, which recess adjoins the at least one cavity, and an insert is arranged in the at least one recess of the upper part, which insert is movable relative to the upper part, and/or an insert is arranged in the at least one recess of the lower part, which insert is movable relative to the lower part.

Preferably, at least one recess is formed in each of the upper part and the lower part. In particular, a plurality of recesses are preferably formed in each case in the upper part and in the lower part. Each recess adjoins exactly one cavity, and an insert is arranged in each recess.

According to an advantageous embodiment of the invention, the recess has at least one substantially trapezoidal cross section, wherein at least two opposing walls of the trapezoidal cross section run obliquely to one another.

According to an advantageous further development of the invention, the insert has at least one substantially trapezoidal cross section, wherein at least two opposite sides of the trapezoidal cross section run obliquely to one another.

In this case, it is advantageous if the recess and the insert are arranged such that, when the injection molding tool is closed, the insert is pressed in the direction of the cavity adjoining the recess. The insert is locked in the connection between the cavity and the recess. Thus, the insert defines a cavity. Thus, the molding material located in the cavity is prevented from entering the recess.

According to a preferred embodiment of the invention, the recess and the insert are arranged such that, when the injection molding tool is closed, the upper insert is brought into contact with the lower insert, the upper insert being arranged in the upper recess and the lower insert being arranged in the lower recess.

The upper insert arranged in the upper recess presses the lower insert arranged in the lower recess into the lower part of the injection molding tool and presses it in the direction of the lower cavity adjoining the lower recess. Likewise, the lower insert arranged in the lower recess presses the upper insert arranged in the upper recess into the upper part of the injection molding tool and presses in the direction of the upper cavity adjoining the upper recess.

Preferably, in the case of an open injection molding tool, the insert projects beyond the surface of the upper part and/or of the lower part. Here, the surface of the upper part is the face facing the lower part with respect to the closed injection tool, and the surface of the lower part is the face facing the upper part with respect to the closed injection tool.

Preferably, in the case of a closed injection molding tool, the upper side of the insert is flush with the surface of the upper part and/or of the lower part.

Particularly preferably, in the case of an open injection molding tool, the insert is removed from an inner wall of the recess, which inner wall is opposite a surface of the upper part and/or of the lower part.

According to an advantageous embodiment of the invention, the insert is held in the upper part and/or in the lower part by means of a screw. The bolt is fixedly connected to the insert and is also movable together with the insert relative to the upper part and/or relative to the lower part.

A method for producing a wiper rubber using a device according to the invention is also proposed, wherein the device comprises an injection molding tool having an upper part and a lower part, and wherein at least one cavity for receiving a molding material is formed in the upper part and/or in the lower part, and wherein at least one recess is formed in the upper part and/or in the lower part, which recess adjoins the at least one cavity, and wherein an insert is arranged in the at least one recess, which insert is movable relative to the upper part and/or the lower part.

The method according to the invention for producing a wiper rubber comprises the following steps:

-closing the injection tool, whereby the insert is pressed in a direction towards the cavity adjoining the recess,

-injecting a moulding material into the cavity,

-opening the injection-moulding tool,

-removing the wiper rubber from the cavity.

Advantages of the invention

Thus, with the device according to the invention, a wiper rubber can be produced by the method according to the invention, which wiper rubber has a relatively sharp wiper edge. The wiping edge of the wiping rubber is produced in the region in which the insert adjoins the cavity and latches the connection between the cavity and the recess. In this case, when the injection molding tool is closed, the insert is pressed onto the cavity with a defined force due to the geometric shape of the recess and the insert. The insert is thereby reliably locked in the connection between the cavity and the recess and prevents the molding material located in the cavity from entering into the recess. Thus, a substantially right-angled edge is formed in the region in which the insert adjoins the cavity, said edge having no or no inner diameter. As a result, a relatively sharp wiping edge is produced in this region.

The wiping edge of the wiping rubber is advantageously formed directly in the injection molding tool. Consequently, no subsequent cutting of the wiper rubber to produce a sharp wiper edge is required. Thus, a separate process step for cutting the wiper rubber is eliminated. Thereby, the manufacturing time is advantageously shortened, and the manufacturing cost is advantageously reduced.

Drawings

Embodiments of the invention are explained in more detail with reference to the drawings and the following description.

FIG. 1: a cross-sectional view of an injection molding tool of a device for producing wiper rubber in a closed state,

FIG. 2: an enlarged cross-sectional view of the lower part of the injection molding tool in the open state,

FIG. 3: a cross-sectional view similar to fig. 2 of the lower part of the modified injection molding tool.

Detailed Description

In the following description of the embodiments of the invention, identical or similar elements are denoted by identical reference numerals, wherein repeated descriptions of these elements are omitted in individual cases. The figures only schematically show the subject matter of the invention.

Fig. 1 shows a sectional view of an injection molding tool 10 of a device for producing wiper rubber in a closed state. The injection molding tool 10 includes an upper part 20 and a lower part 40. In the view shown here, the injection molding tool 10 is closed and the upper part 20 rests flush on the lower part 40.

The lower part 40 of the injection molding tool 10 comprises a substantially flat, lower surface 45 which faces the upper part 20 in the closed state of the injection molding tool 10. A plurality of lower cavities 41 are formed in the lower surface 45 of the lower part 40. Furthermore, a plurality of lower recesses 42 are formed in the lower surface 45 of the lower part 40. The lower cavity 41 and the lower recess 42 are arranged such that the lower cavity 41 adjoins the lower recess 42, respectively.

Each lower recess 42 has a generally trapezoidal cross-section. In each lower recess 42 a lower insert 50 is arranged. The lower insert 50 also has a generally trapezoidal cross-section. The lower insert 50 is held in the lower part 40 by means of bolts 15. The lower insert 50 is movable relative to the lower member 40. The bolt 15 is fixedly connected to the lower insert 50. Thus, the bolt 15 is also movable relative to the lower member 40.

The upper part 20 of the injection molding tool 10 comprises a substantially flat, upper surface 25 which faces the lower part 40 in the closed state of the injection molding tool 10. A plurality of upper cavities 21 are formed in an upper surface 25 of the upper part 20. Furthermore, a plurality of upper recesses 22 are formed in an upper surface 25 of the upper part 20. The upper cavity 21 and the upper recess 22 are arranged such that the upper cavity 21 adjoins the upper recess 22, respectively.

Each upper recess 22 has a generally trapezoidal cross-section. An upper insert 30 is arranged in each upper recess 22. The upper insert 30 also has a generally trapezoidal cross-section. The upper insert 30 is held in the upper part 20 by means of a bolt 15. The upper insert 30 is movable relative to the upper member 20. The bolt 15 is fixedly connected to the upper insert 30. Thus, the bolt 15 is also movable relative to the upper part 20.

The upper cavity 21 in the upper part 20 and the lower cavity 41 in the lower part 40 are arranged in such a way that the upper cavity 21 and the lower cavity 41 each produce a negative contour of the wiper rubber to be produced.

The lower recess 42 and the upper recess 22 are arranged such that, in the case of a closed injection molding tool 10, the upper recess 22 is adjacent to the lower recess 42 in each case. The lower insert 50 and the upper insert 30 are also arranged such that, with the injection molding tool 10 closed, the upper insert 30 is in contact with the lower insert 50.

Fig. 2 shows an enlarged sectional view of the lower part 40 of the injection molding tool 10 in the open state. The lower recess 42 has a substantially trapezoidal cross section, as already mentioned.

The lower recess 42 is delimited by a front wall 43, a rear wall 44 and an inner wall 46. The lower surface 45 defines a fourth side of the trapezoidal cross-section. The rear wall 44 now faces the nearest, lower cavity 41. The rear wall 44 extends here approximately at right angles to the lower surface 45.

The front wall 43 extends obliquely to the rear wall 44 and obliquely to the lower surface 45, said front wall being opposite the rear wall 44. The inner wall 46 extends substantially at right angles to the rear wall 44 and substantially parallel to the surface 45 of the lower part.

As already mentioned, the lower insert 50 also has a substantially trapezoidal cross section. The lower insert 50 includes a front side 53, a rear side 54, an upper side 55 and a lower side 56. The upper side 55 extends substantially parallel to the lower side 56. The rear side 54 extends at right angles to the upper side 55 and to the lower side 56. The front side 54 extends obliquely to the rear side 54 and obliquely to the upper side 55 and the lower side 56. Here, the front side surface 53 faces the rear side surface 54. The lower insert 50 is received in the lower recess 42 in such a way that the rear side 54 rests against the rear wall 44. Furthermore, the front flank 53 abuts against the front wall 43. The underside 56 is adjacent the inner wall 46. The upper side 55 extends offset parallel to the lower surface 45.

The bolt 15 passes through the inner wall 46 and is screwed into the underside 56 of the lower insert 50. In this case, the bolts 15 prevent the lower insert 50 from falling out of the lower recess 42. The screw 15 is fixedly connected to the lower insert 50 and can be moved together with it relative to the lower part 40.

The rear side 54 of the lower insert 50 has a recess. Thus, in the region adjacent to the upper side 55 and adjacent to the lower side 56, the rear side 54 of the lower insert 50 rests against the rear wall 44 of the lower recess 42. In the central region, the rear side 54 is removed from the rear wall 44.

In the illustration shown here, the lower insert 50 projects from the lower recess 42 in the case of an open injection molding tool 10. Here, the upper side 55 of the lower insert 50 is displaced a first distance 71 from the lower surface 45 of the lower part 40. Likewise, the underside 56 of the lower insert 50 is displaced a second distance 72 from the inner wall 46 of the lower recess 42.

Here, the second distance 72 is greater than or equal to the first distance 71. Currently, the first distance 71 is about 0.03 mm. The second distance 72 is currently about 0.1 mm.

The front wall 43 of the lower part 40 is now inclined with respect to the rear wall 44 by about 6 °. Likewise, the front side 53 of the lower insert 50 is inclined at about 6 ° to the rear side 54.

The upper part 20 is constructed symmetrically to the lower part 40. The upper recess 22 in the upper part 20 is geometrically identically formed to the lower recess 42 in the lower part 40. Likewise, the upper insert 30 in the upper recess 22 is configured identically to the lower insert 50 in the lower recess 42.

To produce the wiper rubber, the injection molding tool 10 is first closed, as shown in fig. 1. When the injection molding tool 10 is closed, the upper insert 30 is in direct contact with the lower insert 50. Here, the upper insert 30 is pressed into the upper recess 22, and the lower insert 50 is pressed into the lower recess 42.

Due to the obliquely extending front flank 53 and the obliquely extending front wall 43, the lower insert 50 is also pressed in the direction of the rear wall 44 and thus also in the direction of the adjoining, lower cavity 41. Similarly, the upper insert 30 is pressed in the direction of the adjoining upper cavity 21. Thus, the lower insert 50 seals the lower cavity 41 and the upper insert 30 seals the upper cavity 21.

With the injection molding tool 10 fully closed, as shown in fig. 1, the upper side 55 of the lower insert 50 is flush with the lower surface 45 of the lower part 40. Likewise, the corresponding upper side of the upper insert 30 is flush with the upper surface 25 of the upper part 20.

Subsequently, the molding material is injected into the

cavities

21, 41. After the injection material has been vulcanized and cured, the injection tool 10 is opened again. In this case, the lower insert 50 is again partially moved out of the lower recess 42. Likewise, the upper insert 30 is partially moved out of the upper recess 22. With the injection molding tool 10 open, the upper side 55 of the lower insert 50 is again displaced a first distance 71 from the lower surface 45 of the lower part 40.

Subsequently, the wiper rubber produced can be removed from the lower cavity 41.

Fig. 3 shows a sectional view similar to fig. 2 of the lower part 40 of the modified injection molding tool 10 in the open state.

In the case of the injection molding tool 10 shown in fig. 1 and 2, the

cavities

21, 41 are always oriented in the same direction, which means that the regions of the

cavities

21, 41, at which the wiper edges are formed, are oriented in the same direction. Thus, the

cavities

21, 41 and the

recesses

22, 42 alternate with each other in the upper part 20 and in the lower part 40, respectively.

In the lower part 40 of the modified injection molding tool 10, which is shown in fig. 3, the lower cavities 41 and the lower recesses 42 are each oriented alternately. This means that the two lower recesses 42 are arranged side by side, respectively, and the two lower cavities 41 are arranged side by side, respectively. From two lower cavities 41 arranged next to one another, regions are either directed toward one another or remote from one another, at which regions a wiping edge of the wiping rubber is formed.

Correspondingly, an upper cavity 21 and an upper recess 22 are arranged in the upper part 20.

The present invention is not limited to the embodiments described herein and the aspects highlighted therein. Rather, within the scope of what is described by the description, a plurality of variants are possible, which variants are within the framework of the processing of the skilled worker.

Claims

1. Device for producing wiper rubber, comprising an injection molding tool (10) having an upper part (20) and a lower part (40), wherein at least one cavity (21, 41) is formed in the upper part (20) and/or in the lower part (40) for receiving a molding compound, characterized in that,

at least one recess (22, 42) is formed in the upper part (20) and/or in the lower part (40), said recess adjoining the at least one cavity (21, 41), and an insert (30, 50) is arranged in the at least one recess (22, 42), said insert being movable relative to the upper part (20) and/or the lower part (40).

2. Device according to claim 1, characterized in that the recess (22, 42) has an at least approximately trapezoidal cross section, wherein at least two opposing walls (43, 44) of the trapezoidal cross section run obliquely to one another.

3. Device according to claim 2, characterized in that the insert (30, 50) has an at least approximately trapezoidal cross section, wherein at least two opposite sides (53, 54) of the trapezoidal cross section run obliquely to one another.

4. A device according to claim 3, characterized in that the recess (22, 42) and the insert (30, 50) are arranged such that, when the injection tool (10) is closed, the insert (30, 50) is pressed in a direction towards the cavity (21, 41) adjoining the recess (22, 42).

5. The device according to claim 1, characterized in that the recess (22, 42) and the insert (30, 50) are arranged such that upon closing the injection tool (10) an upper insert (30) is brought into contact with a lower insert (50), the upper insert being arranged in the upper recess (22) and the lower insert being arranged in the lower recess (42).

6. Device according to claim 1, characterized in that, in the case of an open injection molding tool (10), the insert (30, 50) projects beyond the surface (25, 45) of the upper part (20) and/or of the lower part (40).

7. Device according to claim 6, characterized in that, in the case of a closed injection molding tool (10), the upper side (55) of the insert (30, 50) is flush with the surface (25, 45) of the upper part (20) and/or of the lower part (40).

8. Device according to claim 1, characterized in that, in the case of an open injection molding tool (10), the insert (30, 50) is removed from an inner wall (46) of the recess (22, 42), which is opposite a surface (25, 45) of the upper part (20) and/or of the lower part (40).

9. Device according to claim 1, characterized in that the insert (30, 50) is held in the upper part (20) and/or in the lower part (40) by means of a bolt (15).

10. Method for manufacturing a wiper rubber with a device according to any one of the preceding claims, comprising the steps of:

-closing the injection tool (10), whereby the insert (30, 50) is pressed in a direction towards the cavity (21, 41) adjoining the recess (22, 42),

-injecting a moulding material into the cavity (21, 41),

-opening the injection molding tool (10),

-removing the wiper rubber.