WO2016206830A1

WO2016206830A1 - Plug that is easier to produce using injection moulding

Info

Publication number: WO2016206830A1
Application number: PCT/EP2016/059228
Authority: WO
Inventors: Lars Wittko; Ernst Hauk; Karl Stichleutner
Original assignee: Robert Bosch Gmbh
Priority date: 2015-06-22
Filing date: 2016-04-26
Publication date: 2016-12-29
Also published as: KR20180018813A; CN107836064B; KR102503959B1; EP3311452A1; DE102015211417A1; EP3311452B1; CN107836064A

Abstract

Plug (1) for producing an electrical connection protected against polarity reversal, comprising a moulded part (2) made of a plastic, the outer circumference of which is formed at least in one sub-region by a cuboid (3) having rounded edges (4a, 4b), which is continued into a semi-circular cylinder (5), wherein the moulded part (2) comprises a cavity (7) open towards the end face (6) thereof for receiving the electrical contacts (8a, 8b, 8c) and wherein said end face (6) contains the bottom surface (3a) of the cuboid (3), wherein at least one lateral face (9, 10, 11) of the cuboid (3) comprises at least one recess (12, 13, 4, 15) extending along the rounded edge (4a, 4b).

Description

Description Title:

Plug with improved manufacturability by injection molding

The present invention relates to connectors for the electrical contacting of units in the engine compartment of motor vehicles.

State of the art

For electrical contacting of aggregates in the engine compartment of motor vehicles, among other plug connections are used, which is also referred to as "plastic AK plug". This plug is known for example from DE 101 15 322 AI and DE 10 2011 081 534 AI.

The plug has a molded part in which a part of the outer circumference is semicircular and an opposite part of the outer circumference is straight. This molding is made by injection molding. In this case, liquid plastic is injected at high temperature and a pressure of several 100 bar in a multi-part mold, which forms a negative of the desired shape of the molding. The mold is then opened and the molded part dissolved out of her

(Demoulded).

The outer circumference of the plug must be inserted into a matching inner circumference of its counterpart, so that an electrical connection can be made. The asymmetric outer circumference of the plug ensures in this way that the plug is connectable only in a certain orientation with its counterpart, which precludes reverse polarity of the electrical connection. In the production of a variant of the plastic AK plug material is recessed on the straight part of the outer circumference by protruding pins mounted on the injection mold frontally into the mold for the molding and are pulled out after cooling of the plastic from the molding. By this mass recess should be avoided that accumulations of material on the straight part of the outer circumference lead to increased distortion of the molding during cooling after injection molding. This is paid for by the fact that due to the low heat dissipation along the thin pins, the cores designed in this way require a high cooling time. Otherwise, some fluid still adheres to the pins; In addition, the pins are mechanically and thermally stressed by the melt pressure and the high temperatures.

Disclosure of the invention

Within the scope of the invention, a plug has been developed for producing a reverse polarity-proof electrical connection. This plug comprises a molded part made of a plastic whose outer circumference is formed, at least in a partial region, by a cuboid with rounded edges, which is continued in a semicircular cylinder. The molding has a cavity open towards its end face for receiving the electrical contacts. The front side also contains the bottom surface of the cuboid.

In this case, on the outer circumference of the molded part and other shape features, such as locking lugs mounted. Likewise, the inner wall of the cavity guiding and / or locking elements may contain, which simplify the connection of the plug with its counterpart and / or secure.

According to the invention, at least one lateral surface of the cuboid has at least one recess extending in this lateral surface along the rounded edge. This recess may in particular be arranged between a rounded edge of the cuboid and the cavity in the sense that the recess is traversed on a path from the rounded edge into the cavity. Particularly advantageous are a first recess between the one rounded edge of the cuboid and the cavity and a second Recess between the other rounded edge of the cuboid and the cavity provided.

It has been found that in this way material accumulations on the straight part of the outer periphery of the molding can be much easier and more effectively reduced. The negative mold of the recess provided according to the invention can be integrated directly into the inner circumference of the mold used for injection molding. This inner circumference can be cooled, so that the heat removal from the region of the recess is improved. The recess can thereby be produced in a defined manner. This contributes further in that the aspect ratio between the width and depth of the recess for demolding is much cheaper than in a production of the recess with a long pin to be pulled out from the front.

Thus, dimensional accuracy of the molded article produced by injection molding can be improved. Series production is more stable and the quality control effort can be reduced.

Furthermore, more material can be excluded by the recess altogether. Compared to a prior art plug, about 3% of material can be saved.

The plug according to the invention is completely interoperable with the already existing counterparts according to the prior art. It does not differ in the handling of connectors according to the prior art. However, it is more stable than a plug in which an enclosed cavity has been created as a recess within the straight portion of the molding by encasing and then withdrawing a long pin. A thin wall of such a cavity may possibly break with rough handling of the plug, such as with pliers.

Advantageously, the recess extends over less than half of the lateral surface of the cuboid, in which it is introduced. Then remains of this lateral surface still a sufficient part left to intervene positively in an inner circumference on the counterpart of the plug. In a particularly advantageous embodiment of the invention, the cavity is cylindrical at least in a partial area with a base whose circumference is composed of two circular arcs and a rectangle into which both arcs pass on opposite sides of the rectangle. In particular, a circular arc may be concentric with the half-cylinder forming the outer periphery of the molded part. By suitable positioning and dimensioning of the cavity, its wall thickness can then be kept constant in the areas in which its base area is defined by the circular arc concentric with the half-cylinder or by the rectangle. Only in the area of the second circular arc is the cavity surrounded by more plastic because of the desired asymmetry of the molded part. A part of this plastic can be excluded by the inventively provided recess.

Advantageously, the cross section of the recess tapers on the way from the lateral surface of the cuboid into the interior of the molded part. This simplifies the demolding after injection molding on the one hand. On the other hand, the recess can thereby be approximated to the shaping of the cavity in order to minimize the additional thickness of the wall due to the asymmetry of the molded part.

For this purpose, the recess is guided in a particularly advantageous embodiment of the invention, starting from the rounded edge of the cuboid along a sloping edge into the molding and along a rising edge back to the lateral surface of the cuboid. In this case, in particular, the rising edge of the recess may be less steep than the falling edge of the recess. The recess may thus have, for example, a kind of sawtooth shape which, starting from the rounded edge of the cuboid, initially extends perpendicularly into the molded part, in order then to slowly approach the lateral surface of the cuboid again.

In a particularly advantageous embodiment of the invention, the rising edge of the recess is curved in the same way as the semicircular cylinder. In this way, the recess can emulate the shape of the cavity particularly well. It can thus be achieved in particular that the Wall thickness di of the cavity in the region of the recess is equal to the wall thickness d _{2 of} the cavity in the region of the semicircle cylinder.

Advantageously, the recess is continued in the end face of the molding. This creates a small game when merging the connector with its counterpart and thus facilitates in particular the merging, if this must be done only with the aid of the sense of touch due to the cramped conditions in the engine compartment of a vehicle without visual contact with the connector.

In a further particularly advantageous embodiment of the invention, the narrow lateral surface of the cuboid on a parallel to the rounded edges of the cuboid and centrally disposed between these rounded edges flat area. The deviation provided by the inventively provided recess of the outer circumference of the plug from the plug according to the prior art then has little effect on the positive connection with the counterpart of the plug.

Further measures improving the invention will be described in more detail below together with the description of the preferred embodiments of the invention with reference to figures.

embodiments

It shows:

Figure 1 connector 1 according to the prior art in frontal view (a) and in perspective view (b);

Figure 2 embodiment of a connector 1 according to the invention with two recesses 12 and 13 in the same lateral surface 10 of the cuboid 3;

Figure 3 modification of the embodiment shown in Figure 2 with continued in the end face 6 recesses 12 and 13; Figure 4 embodiment of a connector 1 according to the invention with two recesses 14 and 15 in different lateral surfaces 9 and 11 of the cuboid third

FIG. 5 shows a modification of the embodiment shown in FIG. 4 with recesses 14 and 15 continued in the end face 6.

Figure la shows a plastic AK plug 1 according to the prior art in a plan view of the end face 6. The plug 1 includes a molded part 2 made of plastic. This molded part 2 is formed by a cuboid 3 with rounded edges 4a and 4b. On the side opposite the rounded edges 4a and 4b, the cuboid 3 is continued into a semicircular cylinder 5. The front side 6 of the plug 1 is composed of the bottom surface 3 a of the cuboid 3 and of the bottom surface 5 a of the semicircle cylinder 5.

Near the rounded edges 4a and 4b, material is removed from the molding 2, starting from the end face 6, so that the molding 2 is traversed by two recesses 3b and 3c which run parallel to the rounded edges 4a and 4b through the molding 2. The recesses 3a and 3b were introduced during the production of the molding 2 by injection molding by means of pins which were arranged at the location of the later recesses 3b and 3c in the mold for the molding 2 and after cooling of the plastic to the end face 6 out of the Molded part 2 were pulled out.

The molded part 2 has a cavity 7 which is open toward its front side 6. The electrical contacts 8a, 8b, 8c of the plug 1 are accommodated in this cavity 7. The cavity 7 is cylindrical with a base 16 whose periphery is composed of two circular arcs 18, 19 and a rectangle 20. In this case, the circular arc 18 merges into the rectangle 20 at a first side 20a, and the circular arc 19 merges into the rectangle 20 at an opposite side 20b from the first side 20a. The circular arc 18 is concentric with the half cylinder. 5 Figure lb shows the plug 1 according to the prior art in a perspective view in an embodiment without the recesses 3b and 3c. The outer periphery of the molded part 2 has an additional locking lug 30 for locking the connection of the plug 1 with its counterpart. The structures 31, 32, 34 and 36 correspond to material recesses at the bottom of the counterpart of the plug, which are provided there to avoid buildup. The structures 33 and 35 are codes that serve to prevent confusion with other connectors of the same number of poles.

The total width of the molded part 2, measured from the center of the narrow lateral surface 10 along a normal to this narrow lateral surface to the outer edge of the hollow cylinder 5, depends on the number of electrical contacts 8a, 8b, 8c. For two contacts this total width is advantageously 19.8 mm, for three contacts 24.9 mm, for four contacts 29.8 mm, for five contacts 34.8 mm and for six contacts 39.8 mm. The total height of the molded part 2, measured from the center of the lateral surface 9 along a normal thereto to the middle of the lateral surface 11 (without consideration of the locking lug 30) is advantageously 13.8 mm. The cavity 7 is advantageously 21 mm deep. The wall thickness of the molded part 2 is in the region of the rectangle 20 and the hollow cylinder 5 advantageously between 1 and 2 mm.

Figure 2 shows a first embodiment of a connector 1 according to the invention in a perspective view. The perspective is the same as in FIG. 1b. The provided according to the prior art recesses 3b and 3c are replaced by recesses 12 and 13, which are introduced into the narrow lateral surface 10 of the cuboid 3. In this case, the recess 12 extends along the rounded edge 4a, and the recess 13 extends along the rounded edge 4b. The length of the recesses may vary.

The recesses 12 and 13 each extend in this embodiment over about one third of the narrow lateral surface 10 of the cuboid 3, wherein any other expansions are possible. Between the recesses 12 and 13, a flat region 23 extends parallel to the recesses 12 and 13 and also parallel to the rounded edges 4a and 4b of the cuboid 3. This flat region 23 is a part of the original shell surface 10 of the cuboid 3, which was not changed by the recesses 12 and 13. The rounded edges 4a and 4b of the cuboid 3 and the planar region 23 are in the same manner on an inner circumference of the counterpart when merging the plug 1 with its counterpart as the narrow lateral surface 10 of the cuboid 3 in a connector 1 according to FIG.

The cross section of the recesses 12 and 13 tapers on the way from the lateral surface 10 of the cuboid 3 in the interior of the molded part 2. If after cooling of the plastic from which the molded part 2 was produced by injection molding, on the lateral surface 10 of the cuboid third still a part of the mold with the negative shape of the recesses 12 and 13 is applied, the molded part 2 can be separated (removed from the mold) by simply pulling this part of the mold.

Starting from the rounded edge 4a of the cuboid 3, the recess 12 is guided along a vertically falling flank 21a into the molded part 2. It is then guided along a curved, rising edge 22a back to the lateral surface 10 of the cuboid 3 and meets there on the flat portion 23. In this case, the rising edge 22a is curved in the same way as the semicircular cylinder 5, so that the wall of the cavity. 7

is symmetrized.

Analogously, the recess 13, starting from the rounded edge 4b of the cuboid 3, is guided along a vertically sloping flank 21b into the molded part 2. It is then guided along a curved, rising edge 22b back to the lateral surface 10 of the cuboid 3 and meets there on the flat portion 23. In this case, the rising edge 22b is curved in the same way as the semicircular cylinder fifth

In the connection of the plug 1 with its counterpart on the one hand, the outer circumference of the molded part 2 is encompassed by an inner periphery of the counterpart. On the other hand, the cavity 7 of the plug 1 also surrounds an outer circumference of the region of the counterpart in which its electrical contacts are arranged. The embodiment shows three contacts 8a, 8b, 8c, but it is possible any number of contacts.

FIG. 3 is drawn from the same perspective as FIG. 2. The embodiment shown in FIG. 3 differs from that shown in FIG

Embodiment in that the recesses 12 and 13 are continued in the end face 6 in. So you are open to the end face 6. The depth of the recesses 12 and 13 is in each case selected such that the wall thickness di of the cavity 7 in the region of these recesses 12 and 13 is equal to the wall thickness d _{2 of} the cavity 7 in the region of the semicircle cylinder 5. This causes that necessary to ensure the polarity reversal asymmetry of the outer circumference of the molding 2 is accompanied only with a minimum asymmetry of the wall thickness of the cavity 7. The delay of this cavity in the production of the molding 2 by injection molding is thus minimized.

Also in the embodiment shown in Figure 2 wall thickness di of the cavity 7 in the region of these recesses 12 and 13 equal to the wall thickness d _{2 of} the cavity 7 in the region of the semicircle cylinder 5. However, this is not visible in Figure 2, since the recesses 12 and 13th are hidden by the bottom surface 3a of the cuboid 3.

FIG. 4 shows a further embodiment of the plug 1 according to the invention. In contrast to the exemplary embodiments shown in FIGS. 2 and 3, the recesses 14 and 15 are here in different lateral surfaces

9 and 11 of the cuboid 3 introduced. The recess 14 is introduced into the upper broad lateral surface 9 of the cuboid 3. The recess 15, which is concealed in the perspective of Figure 4, is introduced into the lower broad lateral surface 11 of the cuboid 3.

Analogous to the exemplary embodiments shown in FIGS. 2 and 3, the cutout 14, starting from the rounded edge 4a of the cuboid 3, is guided into the molded part 2 in a vertically falling flank 21c. It is then guided along a curved, rising flank 22c back to the upper, wide lateral surface 9 of the cuboid 3 and strikes the area there, in which the periphery 17 of the base 16 of the cavity 7 is defined by the rectangle 20. The same applies to the recess 15, which is hidden in FIG.

The embodiment shown in Figure 5 differs from the embodiment shown in Figure 4 in that the recesses 14 and 15 continued into the end face 6 of the molding part 2 and thus are open to this end face 6 out. As a result, it can be seen in FIG. 5 that the recess 15, starting from the rounded edge 4b of the cuboid 3, is guided into the molded part 2 in a vertical sloping flank 21d. The subsequent rising curved edge 22d leads back to the lower broad lateral surface 11 of the cuboid third

The depth of the recesses 14 and 15 is selected so that the wall thickness di of the cavity 7 in the region of the recesses 14 and 15 is equal to the wall thickness d _{2 of} the cavity 7 in the region of the semicircle cylinder 5. As a result, along the entire circumference of the cavity 7, its wall thickness is maximally symmetrical. A delay of this cavity 7 during cooling of the plastic after injection molding is therefore advantageously minimized.

This also applies to the embodiment shown in Figure 4, but is not visible there because the recesses 14 and 15 are hidden by the bottom surface 3a of the cuboid 3.

Claims

claims

1. Plug (1) for producing a reverse polarity-proof electrical connection, comprising a molded part (2) made of a plastic whose outer periphery is formed at least in a partial area by a cuboid (3) with rounded edges (4a, 4b), which in a semicircle cylinder (5) is continued, wherein the molded part (2) has an open towards its end face (6) cavity (7) for receiving the electrical contacts (8a, 8b, 8c) and wherein said end face (6), the bottom surface (3a) of the cuboid (3), characterized in that at least one lateral surface (9, 10, 11) of the cuboid (3) at least one in this lateral surface (9, 10, 11) along the rounded edge (4a, 4b) extending recess (12, 13, 14, 15).

2. plug (1) according to claim 1, characterized in that a first recess (12, 14) between the one rounded edge (4a) of the cuboid (3) and the cavity (7) and a second recess (13, 15) between the other rounded edge (4b) of the cuboid (3) and the cavity (7) are provided.

3. Plug (1) according to one of claims 1 to 2, characterized in that extending the recess (12, 13, 14, 15) over less than half of the lateral surface (9, 10, 11) of the cuboid (3) ,

4. Plug (1) according to one of claims 1 to 3, characterized in that the cavity (7) is cylindrical at least in a partial area with a base surface (16) whose circumference (17) consists of two circular arcs (18, 19) and a rectangle (20) into which both circular arcs (18, 19) merge on opposite sides (20a, 20b) of the rectangle (20).

5. plug (1) according to claim 4, characterized in that a

Circular arc (18) is concentric with the half-cylinder (5).

6. Plug (1) according to one of claims 1 to 5, characterized in that the cross section of the recess (12, 13, 14, 15) on the way from the lateral surface (9, 10, 11) of the cuboid (3) tapered into the interior of the molding (2).

7. plug (1) according to one of claims 1 to 6, characterized in that the recess (12, 13, 14,15), starting from the rounded edge (4a, 4b) of the cuboid (3) along a sloping edge (21a , 21b, 21c, 21d) in the molded part (2) and along a rising edge (22a, 22b, 22c, 22d) back to the lateral surface (9, 10, 11) of the cuboid (3) is guided.

8. Plug (1) according to claim 7, characterized in that the rising edge (22a, 22b, 22c, 22d) of the recess (12, 13, 14, 15) is less steep than the falling edge (21a, 21b, 21c , 21d) of the recess (12, 13, 14, 15).

9. plug (1) according to one of claims 7 to 8, characterized in that the rising edge (22a, 22b, 22c, 22d) of the recess (12, 13, 14, 15) is curved in the same way as the semicircular cylinder ( 5).

10. plug (1) according to claim 9, characterized in that the

Wall thickness di of the cavity (7) in the region of the recess (12, 13, 14, 15) equal to the wall thickness d _{2 of} the cavity (7) in the region of the semicircle cylinder (5).

11. Plug (1) according to one of claims 1 to 10, characterized in that the recess (12, 13, 14, 15) in the end face (6) of the molded part (2) is continued.

12. Plug (1) according to one of claims 1 to 11, characterized in that the narrow lateral surface (10) of the cuboid (3) parallel to the rounded edges (4a, 4b) of the cuboid (3) and centered between them Edges (4a, 4b) arranged flat region (23).