FR2558426A1 - CONTROL ELEMENT FOR A WINDSCREEN WIPER SYSTEM FOR A MOTOR VEHICLE - Google Patents

Abstract

THE SUBJECT OF THE INVENTION IS A CONTROL ELEMENT INTENDED FOR A WINDSCREEN WIPER SYSTEM FOR A MOTOR VEHICLE, INCLUDING A METAL BAR COATED WITH AN ANTI-CORROSION LAYER WHICH, IN RELATION TO THE BODY OF THE BAR, IS RELATIVELY THIN AND PARTS ALLOWING TO FIX AND OR TO JOIN A LEADING ELEMENT AND A DRIVEN ELEMENT. ACCORDING TO THE INVENTION, THE ANTI-CORROSION LAYER 20 IS CONSTITUTED OF A PLASTIC MATERIAL WITH WHICH BAR 11 IS COATED BY INJECTION MOLDING.

Description

The present invention relates to a control element des-

  a windshield wiper system for a motor vehicle, comprising

  a metal bar coated with an anticorrosion layer which,

  port to the body of the bar, is relatively thin and organs

  setting and / or articulating a driving element and a controlled element. The control elements of a windshield wiper system, such as cranks and connecting rods, are required to transmit relatively high forces and, for reasons of robustness, are

  most often obtained by stamping from metal blanks.

  Since they are exposed to severe weather because of their location on the vehicle, these metal bars must

  be coated with an anticorrosive layer. So far, most

  part were zinc plated. The connecting rods of the windshield wiper systems

  are visible on the vehicle are most often lacquered in black.

  However, the anti-corrosion layer does not meet the requirements of

  resistance to corrosion that has recently been imposed. In

  addition, the lacquering of these elements leads to a waste of time and

  relatively important. Since after lacquering it is necessary to mount fasteners and / or articulation of a driving element and / or led, it is not completely impossible that the anticorrosive layer is damaged during this montage. This is particularly the case if a metal ball joint or a wiper shaft

  must be mounted in a bore of the crank. The layer of

  that can also be damaged if a connecting rod is introduced

  in a mold intended to add a bowl of patella per mold.

injection.

  The object of the invention is to propose control elements

  of this type which can be manufactured at lower cost and capable of

  to meet the growing requirements for anti-corrosion properties

if we.

  According to the invention, the anticorrosion layer is

  formed of a plastic material whose bar is embedded by molding

by injection.

  It is therefore a question of replacing the known layer of lacquer with an anticorrosion layer obtained from a plastic material and of coating the bar with injection molding, and consequently

a connecting rod or a crank.

ú558426

  German patent OS 3,045,504 describes a crank whose metal bar is entirely covered by

  of a plastic material, but the crank of this achievement

  nude is essentially made of plastic and its metal part

  It is only used to strengthen the plastic body. The thickness of the plastic layer is therefore substantially equal to that of this metal reinforcement while, in the present invention, the bar has a traditional material thickness and the plastic layer is much thinner than the bar. In the

  the present invention, the plastic layer serves only as a

  anticorrosion while in the known realization it is necessary

  that the plastic coating has a resistance enabling it, with the metal reinforcement, to transmit the

efforts generated.

  Since to be coated by injection, the barred must necessarily be introduced into a mold for injection. It is

  proposed, to reduce costs and in line with an advan-

  of the invention, simultaneously molding by injection at least one element in the form of a single piece with anticorrosion layer on

  the bar, said member serving to fix and articulate an element

  nant or a led element. It can for example be a ball joint

  lation. With regard to such an achievement, the choice of

  This is a particular problem. He must have a good

  flow titration so that the thickness of the anticorrosive layer can be reduced, even on long bars. Rotu; being executed in the same material, it must also have satisfactory support properties. This means that the material

  must have good robustness, good resistance to

  res and very good sliding properties. It must be able to

  together with the material of the bowl. He's good

  understood that this material must also be resistant to chemicals

  and grease since the hinge joint housed in

  a ball cup is most often lubricated. Given all

  these requirements, most commercial plastics

  current situation must be rejected. After appropriate experiments

  melted, it turned out that optimum results could be achieved

  dyed by producing the anticorrosive layer from a polyamide 6-6

  containing 30 per cent fiberglass and 15 per cent polytech

trafluoréthylène.

L 5 5 8 4 2 6

  Another problem posed by these control

  calf of production is that the bar must be positioned in

  mold for injection so that there is

  pace reduced and as uniform as possible compared to the mold. The longer the bar to be coated by injection, the more difficult the problem is to solve as deformations can not

  be totally excluded because of the molding pressures required

  elevated. A first solution to this problem is to

  the bar in the mold only by the points on which

  injected for example a hinge ball or a bowl

  of patella. This patella bowl or this joint ball joint

  cover certain areas of the bar that were not

  not before because they were in contact with certain parts of the country.

  If the same material is used for the anticorrosive layer and the joint ball joint, satisfactory resistance will be obtained.

in the case of this achievement.

  However, the anticorrosion layer of a particular embodiment

  It is particularly advantageous to use a material having a good flowability and an attractive price, whereas for the patella and the ball cup a better quality plastic material having good supporting properties will be chosen. It can therefore for example be the following problem: the ball cup does not adhere with the necessary force on the bar completely coated with an anticorrosive layer. This disadvantage can however be overcome if, the mold having a suitable configuration, it is ensured that the anticorrosive layer covers only a portion of the bar and that the other parts of the bar are directly

  covered by the plastic material of the cuvettede patella for example.

  The better quality plastic therefore adheres directly to

the metal bar.

  Another solution to the problem of fixing the bar in an injection mold is firstly to injection mold the fastening and articulation members of a driving element and a driven element on the bar and to use these organs to then fix the bar in the mold, the anticorrosion layer being

coated on the bar.

  The problems to fix the bar in the right position in the mold for injections are minor if, for example, one fixes on

  the bar a wiper shaft having been coated with an anti-

  corrosion. In this case, the wiper shaft can be used to

  keep the bar in the correct position in the mold for injection

  tion. The bar common to all these examples of embodiment can

  also be supported by small spacers

  non-corrosive material remaining on the pusher after the

  Injection molding ration. These spacers determine

  the thickness of the anticorrosive layer which is therefore constant on all

  the length of the rods, even if they are longer.

  Since the injection molded ball joints

  on a crank are usually housed in a bowl of rock

  tule placed on the rod, there is a possibility to fix the crank at the ball in the mold with support rods. In this case, the parties who, if necessary,

  are not covered by the anti-corrosion layer, are sufficiently

  protected from the weather by the ball cup when

that the connecting rod is mounted.

  The different objects and features of the invention are

  will now be detailed in the description which follows, made in

  By way of nonlimiting example, with reference to the appended figures which represent: FIG. 1, an enlarged sectional view of a pilot, FIG. 2, a side view of another crank, FIG. in the direction of the arrow A, - Figure 4, a view in the direction of the arrow B, - Figure 5, a sectional view of another crank, - Figure 6, a view of two rods, - Figure 7, an enlarged sectional view of a connecting rod

at the level of its patella bowl.

  Figure 1 shows a crank 10 having a bar 11 partially bent at right angles. This bar is obtained by mastering from a metal blank of a thickness of 5 mm for example. A wiper shaft 13 is engaged by force in a

  opening 12 so that it can not rotate. At its end

  opposite tee, the bar 11 has an elevated portion 14 constituting the

  reinforcement of a hinge joint made by injection molding.

  Cranks having such a basic design are known.

  In the wiper systems, they serve for example to drive a wiper arm attached to the shaft, it being understood that a

  a rod-shaped driving member acts on the gou-

  pillow. The ball joint 15 of this example must therefore be considered as a member articulating a driving element, and the shaft

  windshield wiper as a member fixing a driven element.

  In the context of the present invention, it is important for the bar 11 to be covered with an anticorrosive layer 20 of plastic material. In the embodiment according to FIG. 1, the bar is coated with this plastic material by injection molding and the

  ball joint 15 is injection molded also for the same time.

  The thickness of the anticorrosive layer 20 is about 1 mm or less and is therefore substantially less than that of the bar 11. In this case, the plastic used is a polyamide 6-6

  30 per cent fiberglass and 15 per cent polytechnic

  trafluoréthylène. This material has sufficient flowability

  as well as the necessary support properties.

  The control element is manufactured as shown below.

  After stamping the bar, the wiper shaft 13 is mounted and this structural assembly is then fixed in an injection mold. At this stage, and giving the injection molds a form

  appropriate, ie by providing bores for the daisy tree.

  soot-ice 13, it can be ensured that the bar 11 has on all

  its faces with a uniform spacing relative to the molds for injecting

  tion. In particular, if the anticorrosion layer must remain thin,

  it seems interesting to fix terminal 11 also to the

  end of the mold. For this purpose, the raised portion 14 has a bore 21 into which a retaining pin 22 can be introduced. The assembly formed of the bar 11 and the wiper shaft 13 is

  placed in a good position in the injection mold according to

  in the manner described and is coated with a suitable plastic material by injection molding while, at the same time, the anticorrosion layer and the patella are formed in one piece

  15. It can also be seen in Figure 1 that the anti-aging layer

  Ticorrosion 20 also covers a portion of the wiper shaft, at least at its fastening flanges. He's good

  possible to increase the thickness in this area so that the

  plastic material also helps maintain the link between

2558426.

  the wiper shaft and the bar there.

  When the plastic is cooled, the assembly is removed from the mold and can immediately be used. A housing 23 has been formed by the retaining pin of the mold 22 and in this

  -5 zone, the bar is not immediately protected against corrosion. This-

  when the control element is mounted, the housing 23 is

  covered by a ball cup as shown in the example of the

  7. Figures 2 to 4 show views of another crank

  bearing two ball joints 15a and 15b mounted on corresponding elements 14a and 14b protruding on either side of the bar Il. In this case too, the anticorrosive layer 20 and the ball joints 15 are injection molded with the same material and

  in one piece. Unlike the example in Figure 1, desgou-

  holding piers 22a and 22b act on the front faces 24a and 24b of the raised portions 14. The housings 23a and 23b provided in the ball joints 15a and 15b are therefore placed in an area which is not subjected to stresses when the forces coming from of

  the connecting rod or the ball cup is applied to them.

  Regarding Figure 1, it should be noted that in this case the housing 23 has virtually no adverse impact on the

  transmission of effort to the extent that no high force

  appears in the longitudinal direction of the crank. Housing 23 will be

  later used as a reserve of fat.

  FIG. 5 shows an example in which the fixing element

  30 of a wiper arm is not mounted on a wiper shaft.

  ice but directly on the crank 10 by a stop screw 31.

  In this example, the wiper shaft is replaced by a support sleeve 32 injection molded on the bar 11 in the form of a single piece with the anticorrosive layer 20 and the patella

  15. In this support sleeve 32 engages a threaded stud which is so-

  Lidarized to the body of the motor vehicle. The stop screw 31

  is engaged in a concentric bore 33 to the sleeve 32. To avoid

  that the fastener does not rotate when mounted on the crank, teeth may be provided at the bottom of the front face of the fastener, said teeth engaging in the anticorrosive layer 20. In addition, a partially peripheral collar 34

  can be molded from above and laterally surround the filter element

  30. Figures 6 and 7 refer to a connecting rod of a windshield wiper system. The purpose of Figure 6 is to show that several rods 40 are obtained in one piece by wise stamping from a blank and that two of said rods are connected by a narrow separation core 41. Before being separated, these rods may be coated with an anticorrosion coating

  using a multiple mold. In doing so, the bars are now

  held in the mold at the bore 42 for receiving a

  The ball cup 43. The ball cup 43 is injection molded

  on the connecting rod 40 in the course of a molding operation se-

adorned.

  In FIG. 7, it can be seen that the anticorrosive layer 20 only covers certain parts of the connecting rod 40. In particular, the part o which must be fastened the ball cup later must not

  not be coated with an anticorrosive layer 20, otherwise the

  This ball-and-socket 43 would not be fixed securely enough.

  In this embodiment, the member making it possible to fix and / or

  articulate a driving element and / or a driven element and which, in

  curence, is a ball cup 43, is made from a

  plastic material different from that constituting the anti-corrosion

  20. Preferably, a polyamide 12 with 30 percent glass fibers and a lubricant supply will be used. In addition, FIG. 7 shows small spacers which are made of anticorrosive material and which are fixed in the mold for injection. . When the rod has undergone injection molding all around, these spacers 45 adhere

  to the anticorrosive layer 20. These spacers are particularly suitable for

  especially good for long rods; in their absence, he

  would not be possible to ensure that the distance between the

  evening and the injection mold is steady on all sides, due to the inevitable tolerances. Furthermore, it is important in the example of FIG. 7 that the ends of the separation webs 41 are

  covered by an extension of the ball cup.

  In the embodiment according to FIG. 7, two operations

  Injection molding must be done, one after the other.

  The anticorrosive layer 20 is first applied, after which the

  The ball joint is put in place by molding. The two cuvettes of rotu-

  the rods 40 will be heardmultiple injection.

  Subject to having sufficient supporting properties, the material

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  The rust of the anticorrosive layer could also be used for cuvettes. However, in most cases, a better material

  market will be used to produce the anticorrosive layer 20.

  It is also possible to reverse the order of the two opera-

  separate injection molding and injection molding on the connecting rod. Thus, the cuvettes of ball joints could first be injection molded into the receiving bores 42, after which the complete assembly could be supported in an injection mold.

  by these cuvettes of kneecaps so that on all

  There is still a regular gap between the mold and the part of the rod that has not been coated before. The anticorrosion layer could therefore also

  cover part of the ball bowl.

  Finally, it should be noted that in the implementation according to the

  Figure 5 a windscreen wiper shaft could also be mounted by

  injection molding instead of a support sleeve, provided that the plastic material used is capable of transmitting the high torques. Only in this case would the bar be inserted in

  the mold and, simultaneously or in several successive stages of

  Injection molding, anti-corrosive layer, a ball pan or a ball joint and a wiper shaft would be attached to the bar

by injection molding. -

  In conclusion, it should be noted that control elements for wiper systems can be manufactured in this way

  cheaper. The necessary anticorrosion properties are

  even in the most unfavorable conditions.

Z558426

Claims (22)

  A control element for a windscreen wiper system for a motor vehicle, comprising a metal bar coated with an anticorrosive layer which, with respect to the body of the bar, is   relatively thin and organs for fixing and / or articulating   ler a driving element and a driven element, characterized in that the anticorrosion layer (20) is made of a plastic material which   the bar (11) is coated by injection molding.   2. Control element according to claim 1, characterized   characterized in that the anticorrosive layer is a polyamide 6-6 comprising   30 per cent fiberglass and 15 per cent polytetrafluoride   ethylene. 3. Control element according to claim 1 or 2,   characterized in that at least one member (ball joint 15) serves   to fix and / or articulate a driving element and / or a driven element is a single piece injection molded on the bar (11) with the anticorrosive layer (20).   4. Control element according to claim 1 or 2, characterized in that at least one element (ball cup 43) for fixing and / or articulating a driving element and / or a driven element is injection molded on the bar (11) previously coated with a anticorrosive layer (20).   5. Control element according to claim 4, characterized   characterized in that the anti-corrosion layer (20) covers only a few   parts of the bar (11) and in that the other parts of the bar (11) are covered when the member (ball 43   Y is fixed by injection molding.   6. Control element according to claim 1 or 2,   characterized in that at least one member for fixing and / or   culer a driving element and / or a driven element is injection molded   on the bar, and in that the bar (11) and, if necessary,   parts of said body are then coated with the anti- corrosion.   7. Control element according to one of the claims   4 to 6, characterized in that the member for securing and / or   a driving element and / or the driven element straightened in the same   plastic material as the anticorrosive layer (20).   8. Control element according to one of the claims   4 to 6, in that the member for securing and / or articulating   a menart element and / or a driven element is made in a material   different from that of the anti-corrosion layer (20).   9. Control element according to claim 8, characterized   characterized in that the injection molded body (ball cup)   from a polyamide 12 comprising 30 percent green fiber allied to a lubricant.   10. Control element according to one of the claims   previous, characterized in that a member (wiper shaft 13) for fixing and / or articulating a driving member and / or a driven member is made of metal, and in that said metal piece is fixed at the bar (11) before it is coated   by injection molding by means of an anticorrosive layer (12).   11. Control element according to claim 10,   characterized in that the anticorrosive layer (20) covers at least   parts of the metal member (windscreen wiper shaft 13).   12. Control element according to claim 11, characterized   characterized in that the portion of the anticorrosive layer (20) covering the metal member is reinforced and contributes to fixing this organ at the bar (11).   13. Control element according to one of the claims   previous, characterized in that the bar (11) is fixed in the injection mold by means of small spacers (45) of   anticorrosion material determining the thickness of the anticorrosion layer erosion (20).   14. Control element according to one of the claims   characterized in that the metal bar (11) is part of a crank having at least one high section (14), and in that the member for articulating a driving element and / or a driven element is a ball joint (15) in which is located the   raised portion (14) more or less centrally.   15. Control element according to claim 14,   characterized in that a portion of said raised portion (14) serves   support for a retaining pin (22).   16. Control element according to claim 15,   characterized in that said raised portion (14) has a bore   (21) for introducing a retaining pin (22).   17. Control element according to claim 16,   characterized in that a housing (23) formed in the rotu-   (15) by the retaining pin (22) serves as a reserve of grease.   18. Control element according to one of the claims   14 to 17, characterized in that the other member of the crank (10) is a wiper shaft (13).   19. Control element according to one of the claims   14 to 17, characterized in that a cylindrical bearing sleeve (32) is   injection molded on the crank (10).   20. Control element according to claim 19,   characterized in that the bar (11) has a bore (33) provided for a set screw (31), said bore being concentric with respect to the bearing sleeve (32), and in that a driven element , such as the fastening element (30) of a windscreen wiper arm, can be mounted   on the crank (10) by means of said stop screw.   21. Control element according to one of the claims   1 to 13, characterized in that the metal bar (11) is a   connecting rod with balls of balls (43) injection-molded at its ends.   22. Control element according to claim 20,   characterized in that a plurality of rods (40) are first obtained   naked by forming from a blank in the form of a single piece   that two of said links (40) being connected together by a   narrow webs (41), and in that the ends of said webs   (41) which are not coated with an anticorrosive layer (20) are coated with a plastic material when they receive them.   ball cups (42) injection molded.