JP4239883B2 - Dummy plug for waterproof connector - Google Patents

Description

  The present invention relates to a dummy stopper used for a waterproof connector of a waterproof type of a single room.

  In the waterproof connector of the single room waterproof type, the rubber plug is fixed to the terminal of the electric wire together with the terminal fitting, and the rubber plug is fitted into the cavity entrance to seal the terminal fitting in the cavity formed in the housing. I take the. On the other hand, some cavities do not contain terminal fittings, and such cavities are fitted with rubber dummy plugs that are separately prepared for sealing. In general, this type of dummy plug has three corrugated cross-sections on the outer peripheral surface of the plug body in consideration of insertion force into the cavity, holding force (difficult to pull out from the cavity), and die removal during molding. The ring-shaped lip is formed.

By the way, when such a dummy plug is applied, for example, when the male and female connectors are fitted, the sealed space between the two connectors is compressed, or the internal pressure is increased due to the thermal expansion of the air in the sealed space during use. As a result, the dummy plug could come off the cavity against the holding force. Therefore, conventionally, as described in Patent Document 1, an auxiliary spring member that assists the diameter of the dummy plug to expand and deform in the dummy plug has been proposed to increase the holding force.
Japanese Patent No. 3180026

However, the above-described conventional device has a problem in that the cost is high because two parts of the dummy plug and the auxiliary spring member are required.
The present invention has been completed based on the above circumstances, and an object of the present invention is to provide a dummy stopper that can be manufactured at a low cost while increasing its holding power.

As a means for achieving the above object, the invention of claim 1 is to insert a terminal fitting in a cavity formed in a housing of a waterproof connector into a cavity in which the terminal fitting is not accommodated to seal the cavity in a watertight manner. A dummy plug made of an elastic material is used, and a protrusion having a wide flat top surface is formed on the outer peripheral surface of the plug body, and the bottom has an acute angle at the center in the width direction of the top surface. The pair of lips are formed symmetrically on both sides of the groove, and the opposite side surfaces of the pair of lip surfaces are formed as steep and steep surfaces. Further, the pair of lips are formed at the central portion in the axial direction of the plug body, and both sides of the top are gently inclined at both sides in the axial direction of the plug body. Another Having characterized in that the lip is formed.

<Invention of Claim 1>
When the dummy plug is inserted into the cavity, a so-called edge is formed by the edge of the lip top surface on the side of the surface that stands up. Therefore, when the internal pressure increases, the edge of the lip functions to be caught on the inner peripheral surface of the cavity, and the dummy plug is prevented from coming out of the cavity, that is, the holding force is increased. In addition, since the auxiliary member is not required only by changing the shape of the dummy plug itself, it can be manufactured at low cost. Further, even if the dummy plug is inserted into the cavity in any of the front and rear directions, either one of the edges can be used to prevent the dummy plug from coming off. The insertion work can be performed without worrying about the direction of the dummy plug, and the workability is excellent. Furthermore, with a simple shape such as inserting an acute-angle groove on the wide top surface of the ridge, a pair of lips are formed in a symmetrical posture on both sides of the groove with the splayed surfaces, ie, the edges facing each other. .

<Embodiment>
Hereinafter, an embodiment of the present invention will be described with reference to FIGS.
In FIG. 1, the connector housing 10 is formed with a plurality of cavities 11 into which terminal fittings (not shown) are inserted, and the inlets 12 of the cavities 11 are formed in a circular cross section. At the mouth edge, a lead-in surface 13 is formed by chamfering.
A dummy plug 20 is inserted into the inlet 12 of the cavity 11 into which the terminal fitting is not inserted.

The dummy plug 20 is made of a rubber material such as oil-impregnated silicon and is formed by injection molding in a mold. The dummy plug 20 is roughly formed in a shape in which ring-shaped lips 24 and 30 are formed on the outer peripheral surface of the plug main body 21, and has a symmetrical shape in the axial direction.
Specifically, the plug body 21 is formed in a stepped cylindrical shape having a large-diameter portion 22 over a wide range in the central portion in the axial direction, and the axial direction on the outer peripheral surface of the large-diameter portion 22 of the plug body 21. Lips 24 and 30 are formed at intervals in the central portion and both end portions, respectively. The outer diameter D at the position of each lip 24, 30 is set larger than the inner diameter d of the inlet 12 of the cavity 11 described above.

The lips 24 at both ends are formed in a so-called gentle chevron cross section in which both sides of the top are gentle slopes 25.
On the other hand, a ridge 27 having a wide flat top surface 27A and gentle slopes 27B on both sides is originally formed in the central portion, and the width direction center of the ridge 27 on the top surface 27A is formed. A pair of latching lips 30 (corresponding to the lip of the present invention) are formed on both sides of the groove 28 by cutting the groove 28 having an acute angle at the bottom. The bottom of the groove 28 is rounded.

As described above, the both latching lips 30 are formed so that the top surface 31 is flat in a natural state over a predetermined width, and the opposite side surface is gently steep and the opposite side surface is moderate. It is formed on the inclined surface 33.
The parting line PL in the mold of the dummy plug 20 is set at a valley portion 35 between the lip 24 on one end side and the hooking lip 30 adjacent thereto as shown in FIG. 2 (B). Has been.

  The dummy plug 20 having the above structure is inserted into the inlet 12 of the corresponding cavity 11 as indicated by the arrow in FIG. The dummy plug 20 is inserted while the top portions of the lips 24 and 30 are compressed. Since the dummy plug 20 is basically formed with four lips 24 and 30, the sliding contact area with the inner peripheral surface of the inlet 12 of the cavity 11 is not so large, and therefore a relatively small force. But you can insert it.

As shown in FIG. 3, when the dummy plug 20 is properly inserted into the inlet 12 of the cavity 11, the sharp tops of the lips 24 at both ends are elastically applied to the inner peripheral surface of the inlet 12 of the cavity 11. Thus, a so-called holding force is obtained in which the entire surface is in close contact with each other so that the seal is taken and the movement is restricted by frictional resistance.
On the other hand, in the latching lip 30, the flat top surface 31 is in close contact with the inner peripheral surface of the inlet 12 of the cavity 11 by the elastic force, and the seal is taken. At the same time, a so-called edge 40 is formed by the edge of the top face 31 on the side of the face 32 that stands up.
Therefore, as shown by the white arrow in FIG. 3, when the internal pressure increases, in addition to the frictional resistance by the lips 24 at both ends, in particular, the edge 40 of the latching lip 30 on the back side (right side in the figure). Functions to be caught on the inner peripheral surface of the inlet 12 of the cavity 11, and the dummy plug 20 is prevented from coming out of the cavity 11.

  As described above, according to the dummy plug 20 of the present embodiment, since the latching lip 30 having the edge 40 that is hooked on the inner peripheral surface of the inlet 12 of the cavity 11 is provided, the insertion force into the cavity 11 is reduced. While the increase is minimized, the dummy plug 20 is firmly prevented from coming out of the cavity 11, that is, a high holding force can be obtained. In addition, since the auxiliary member is not required only by changing the shape of the dummy plug 20 itself, it can be manufactured at low cost.

  Since the latch lip 30 is provided with a pair whose directions are reversed in the front, that is, when the edge 40 is dominant, when the dummy plug 20 is inserted into the inlet 12 of the cavity 11, the direction of the front and back is determined one by one. There is no need to worry about, and the dummy plug 20 can be inserted efficiently. Further, the pair of latching lips 30 can be formed by a simple shape in which an acute groove 28 is inserted into the protrusion 27 having the top surface 27A that originally has a wide flat shape. It can be easily retained.

<Other embodiments>
The present invention is not intended to be limited to the embodiments described above with reference to the drawings, but can be implemented in various modifications without departing from the gist.

The partially cutaway side view before inserting the dummy stopper of one Embodiment of this invention in a cavity (A) is a front view of the dummy plug, and (B) is a partially cutaway side view thereof. Partially cutaway side view with dummy plug inserted into cavity

Explanation of symbols

DESCRIPTION OF SYMBOLS 10 ... Connector housing 11 ... Cavity 12 ... Inlet 20 ... Dummy plug 21 ... Plug main body 24 ... Lip 27 ... Projection 27A ... Top surface (of projection 27) 28 ... Groove 30 ... Hanging lip (lip)
31 ... (Hanging lip 30) top surface 32 ... Standing surface 40 ... Edge

Claims (1)

A dummy plug made of an elastic material that is inserted into a cavity in which a terminal fitting is not accommodated among the cavities formed in the housing of the waterproof connector and is used for watertight sealing the cavity,
A protrusion having a wide flat top surface is formed on the outer peripheral surface of the stopper main body, and a groove having an acute angle at the bottom is cut at a central portion in the width direction on the top surface. are formed in a pair of lips is symmetrical on both sides, one side of said pair of lips, opposite sides is formed on the steep faces of the steep, the opposite side is formed on the gently inclined surface, further The pair of lips are formed in the axial center portion of the plug body, and both lips in the axial direction of the plug body are formed with other lips that have gentle slopes on both sides of the top . Dummy plug for waterproof connector.

Images