Patent Publication Number: US-2022239038-A1

Title: Connector Housing

Description:
CROSS-REFERENCE TO RELATED APPLICATIONS 
     This application is a continuation of PCT International Application No. PCT/JP2020/036490, filed on Sep. 26, 2020, which claims priority under 35 U.S.C. § 119 to Japanese Patent Application No. 2019-190919, filed on Oct. 18, 2019. 
    
    
     FIELD OF THE INVENTION 
     The present invention relates to a connector housing provided with a latch arm. 
     BACKGROUND 
     Conventionally, a connector housing is widely adopted that is provided with a latch arm catching on a latched member of a mating housing or the like, for example, and preventing the latched member from being released (for example, see JPH4-137474A). This latch arm extends from a housing main body like a cantilever and has a latch portion catching on a latched member in a middle portion of the cantilever. 
     Additionally, JPH2-186569A discloses a connector housing provided with a housing main body composed of a hard material and a hinge composed of a soft material different from the hard material using a co-injection molding technique. JP2017-177738A discloses a molding apparatus injecting different resin materials from a plurality of gates (inlets) of a mold. 
     The latch arm is required to elastically deform when catching on the latched member of the mating housing or the like. Therefore, a material having a certain degree of softness is selected that allows the latch arm to be elastically deformed by a moderate operating force. 
     Shortening the length of the latch arm is considered in order to satisfy a requirement for size reduction of the connector housing. In that case, the latch arm is required to achieve a sufficient amount of elastic deformation regardless of its short length. In order to satisfy this, an even softer material will be adopted. 
     On the other hand, the latch portion, which is a portion of the latch arm that latches to the latched member, is required to retain its latching with the latched member even if an inadvertent force acts thereon, unless the inadvertent force exceeds a predetermined strength. Therefore, if a soft material is adopted, the latch portion may fail to retain the latching because the latch portion may be cracked or lost when an inadvertent force acts thereon. 
     Applying the co-injection molding technique disclosed in JPH2-186569A to the latch arm is conceivable for forming the latch arm main body and the latch portion from different materials suitable for them, respectively. However, co-injection molding will be more costly because the molding process is performed twice. Additionally, injection molding results in the latch arm main body and the latch portion being more likely to separate at their joint, and the latch portion may be lost when an advertent force is applied. Additionally, JP2017-177738A cited above does not contain any disclosure of a connector housing. 
     In view of these circumstances, there is a need to provide a connector housing with a latch arm suitable for elastic deformation while retaining the strength of a latch portion latching to a latched member. 
     SUMMARY 
     A connector housing includes a housing main body and a latch arm having a latch arm main body and a latch portion protruding from the latch arm main body. The latch arm main body is formed of a first material, extends like a cantilever from the housing main body, and is elastically deformable with respect to the housing main body. The latch portion is formed of a second material having a higher rigidity than the first material and latches with a latched member. A transition region between the first material and the second material has a continuously changing mixing ratio between the first material and the second material. 
    
    
     
       BRIEF DESCRIPTION OF THE DRAWINGS 
       The invention will now be described by way of example with reference to the accompanying Figures, of which: 
         FIG. 1  is an isometric view of a connector according to an embodiment; 
         FIG. 2  is a sectional side view of the connector, taken along arrows X-X of  FIG. 1 ; and 
         FIG. 3  is a schematic diagram of a manufacturing process for a connector housing constituting the connector shown in  FIGS. 1 and 2 . 
     
    
    
     DETAILED DESCRIPTION OF THE EMBODIMENT(S) 
     An embodiment of the present invention will be described below. 
     A connector  10  according to an embodiment, as shown in  FIGS. 1 and 2 , has a connector housing  20  and a contact  30  (see  FIG. 2 ) inserted in the connector housing  20 . 
     In an embodiment, a cable  40  is connected to the contact  30 , and the cable  40  extends out of the connector housing  20 . It should be noted that only a portion of the cable  40  in the vicinity of the connector housing  20  is shown in  FIGS. 1 and 2 . 
     The connector housing  20  has a housing main body  21  and a latch arm  22 , as shown in  FIGS. 1 and 2 . This connector housing  20  is equivalent to an example of a connector housing of the present invention. The latch arm  22  has a front end  22   a  connected to the housing main body  21  and extends rearward like a cantilever using the front end  22   a  as a fixed end. Further, this latch arm  22  is provided with a latch arm main body  221  extending between the front end  22   a  that is the fixed end and a rear end  22   b  that is a free end, and a latch protrusion  222  protruding in the middle of the latch arm main body  221 . The latch protrusion  222  may also be referred to as a latch portion  222 . 
     A mating connector is mated to the connector  10  in the direction of an arrow Z. In the process of the mating, the latch protrusion  222  is pushed by a housing of the mating connector. Thereupon, this latch arm  22  elastically deforms in the direction of an arrow Y shown in  FIG. 2 . Then, when they reach a completely-mated state, the latch arm  22  is released from the depression by the mating connector and returns to its original shape. Thereby, the latch protrusion  222  catches on a latched portion of the mating connector, and the mating connector is put into a locked state so as not to be easily released from this connector  10 . 
     In an embodiment, a first kind of resin material not mixed with glass is used by way of example for the housing main body  21 . The same first kind of resin material as for the housing main body  21  is also used for the latch arm main body  221  constituting the latch arm  22 . On the other hand, a second kind of material having a rigidity increased in comparison with the first kind of resin material by mixing glass into the first kind of resin material is used by way of example for the latch protrusion  222  constituting the latch arm  22 . Additionally, a material mixed with a pigment having a color making the latch portion  222  distinguishable at a glance from the housing main body  21  and the latch arm main body  221  may be used for this latch protrusion  222 . It should be noted that, instead of mixing a pigment in the latch protrusion  222 , a pigment may be mixed in the material of the housing main body  21  and the latch arm main body  221 . 
       FIG. 3  is a schematic diagram showing the outline of a manufacturing process for a connector housing constituting the connector shown in  FIGS. 1 and 2 . 
     A cavity  70  of a mold for manufacturing the connector housing  20  is shown in  FIG. 3 . This cavity  70  has a housing main body portion  71  molding the housing main body  21  and a latch arm portion  72  molding the latch arm  22 . Furthermore, the latch arm portion  72  has a latch arm main body portion  721  molding the latch arm main body  221  and a latch protrusion portion  722  molding the latch protrusion  222 . Further, this mold has inlets  71   a ,  72   a  connected to the housing main body portion  71  and the latch arm portion  72 , respectively, from which materials are injected into the mold. The inlet  72   a  connected to the latch arm portion  72  is provided at a distal end of the latch protrusion portion  722 . 
     Additionally, two cylinders  51 ,  52  are provided, as shown in  FIG. 3 . A first cylinder  51  is connected to the inlet  71   a . Further, a first material  21 A for the housing main body  21  and the latch arm main body  22  is stored in the first cylinder  51 . A second cylinder  52  is connected to the inlet  72   a . Further, a second material  22 A for the latch portion  222  is stored in the second cylinder  52 . 
     The timings to open valves  61 ,  62  are adjusted, and the materials  21 A,  22 A are injected into the cavity  70  of the mold. Thereupon, the first material  21 A for the housing main body  21  and the latch arm main body  221  is injected into the housing main body portion  71  and the latch arm main body portion  721  of the cavity  70 . Additionally, the second material  22 A for the latch protrusion  222  is injected into the latch protrusion portion  722  of the cavity  70 . 
     Thereupon, as shown in  FIG. 3 , a transition region T where these two materials  21 A,  22 A are mixed together is formed in a boundary region where the two kinds of materials  21 A,  22 A before curing come into contact with each other. This transition region T is a region where the ratio of the first material  21 A constituting the latch arm main body  221  increases in the direction of the transition region T encroaching deeper into the latch arm main body portion  721 , and the ratio of the second material  22 A constituting the latch protrusion  222  increases toward the latch protrusion portion  722 . The transition region T has a continuously changing mixing ratio between the first material  21 A and the second material  22 A. 
     In the present embodiment, the two kinds of materials  21 A,  22 A are first injected such that the two kinds of materials  21 A,  22 A come into contact with each other at the boundary between the latch arm main body portion  721  and the latch protrusion portion  722 . Thereafter, outer regions of the injected materials  21 A,  22 A in contact with the mold cure to some extent, and then the pressure in the second cylinder  52  is increased to push the second material  22 A into the latch arm main body portion  721 . Thereupon, the transition region T encroaching in a substantially wedge-like shape, namely in a tapered shape, into the latch arm main body portion  721  and the latch arm main body  221  is formed. Thereby, the transition region T having a wider area can be formed as compared with the case where the two kinds of materials  21 A,  22 A are injected such that these two kinds of materials  21 A,  22 A come into contact with each other at the boundary between the latch arm main body portion  721  and the latch protrusion portion  722 , and the strength of the latch portion  222  can be further increased. 
     In this manner, the connector housing  20  having the latch arm main body portion  221  formed of the first material  21 A suitable for elastic deformation and the latch protrusion  222  formed of the second material  22 A having a high rigidity is completed. Moreover, this connector housing  20 , unlike a connector housing formed by co-injection molding, has the transition region T where the material changes continuously through the transition region T. Therefore, the materials  21 A,  22 A are integrated and an accidental loss of the latch protrusion  222  from the latch arm main body  221  is prevented with high reliability. 
     In an embodiment, the latch arm main body  221  and the latch protrusion  222  have different colors. Therefore, it can be easily confirmed whether the materials are properly molded and well mixed together in the transition region T. 
     It should be noted that using the materials having rigidities adjusted by either mixing or not mixing glass thereinto has been described here by way of example. However, this is an example, and the amounts of glass mixed therein may be changed, or different ingredients may be mixed therein. Alternatively, the resin materials themselves may be different resin materials. 
     Additionally, the latch arm latching with the housing of the mating connector has been chosen and described here. However, the latch arm in the context of the present invention is not limited to the latch arm latching with the housing of the mating connector. For example, the latch arm in the context of the present invention may be a latch arm (a contact lance  23  (see  FIG. 2 )) catching on the contact inserted into the connector housing and preventing the contact from being released.