Abstract:
An injection mold includes a mold plate and a gate insert detachably connected to the mold plate. The molding plate defines a runner for the inflow of melted injection material and a cavity for shaping the melted injection material into a product therein. The gate insert is positioned between the runner and the cavity and the upper portion of a downwardly-inclined gate in the gate insert has a sharp cutting edge, to present a clean ejection cut between the injection material in the runner and the finished product when ejected.

Description:
BACKGROUND 
       [0001]    1. Technical Field 
         [0002]    The present disclosure relates to molds and, particularly, to an injection mold. 
         [0003]    2. Description of Related Art 
         [0004]    Injection molds are configured for molding melted injection material into predetermined shapes. An injection mold generally includes a mold plate. The mold plate defines at least one molding cavity and a runner communicated with the molding cavity, and the runner forms a gate at an end adjacent to the cavity. The injection mold usually works under high temperature and high pressure conditions and, thus, the gate may deformed, for example enlarged, degrading molding quality. In addition, it is difficult to repair the injection mold with a deformed gate and, therefore, the whole mold plate must be discarded if the gate of the injection mold is not qualified anymore, increasing cost. 
         [0005]    What is needed therefore is an injection mold addressing the limitations described. 
     
    
     
       BRIEF DESCRIPTION OF THE DRAWINGS 
         [0006]    The components of the drawings are not necessarily drawn to scale, the emphasis instead being placed upon clearly illustrating the principles of the embodiments of the present disclosure. Moreover, in the drawings, like reference numerals designate corresponding parts throughout several views. 
           [0007]      FIG. 1  is an exploded view of one embodiment of an injection mold, the injection mold including a gate insert. 
           [0008]      FIG. 2  is an enlarged, isometric view of the gate insert of  FIG. 1 . 
           [0009]      FIG. 3  is a cross-sectional view of the gate insert of  FIG. 1 , taken along line 
           [0010]      FIG. 4  is an assembly view of the injection mold of  FIG. 1 . 
       
    
    
     DETAILED DESCRIPTION 
       [0011]      FIGS. 1-3  show one embodiment of an injection mold  100 . The injection mold  100  includes a mold plate  10  and a number of gate inserts  20  positioned in the mold plate  10 . 
         [0012]    The mold plate  10  defines a runner portion  11  and a number of cavities  12  communicated with the runner portion  11 . The runner portion  11  guides melted injection material (not shown) into the cavities  12 . The runner portion  11  includes a main runner  111  and a number of secondary runners  112  communicating with the main runner  111 . Each secondary runner  112  corresponds to a cavity  12  and allows communication a cavity  12  and a main runner  111 . The mold plate  10  can be male or female. In this embodiment, the mold plate  10  is a mold plate of a female mold, and the mold plate  10  can mold products in cooperation with a mold plate of mating male mold. The cavities  12  are configured for molding products therein. The number of the cavities  12  can be changed according to different demands The number of the gate inserts  20  is determined by the number of the cavities  12 . In this embodiment, the number of the cavities  12  is four. 
         [0013]    The mold plate  10  further defines a number of receiving grooves  13  corresponding to the gate inserts  20 . Each receiving groove  13  receives a gate insert  20  therein. Two opposite side surfaces in the receiving groove  13  each define an engaging groove  14  therein. A bottom surface of each engaging groove  14  defines a connecting hole  15 . In this embodiment, the connecting holes  15  are threaded holes. Alternatively, only one engaging groove  14  or more than two engaging grooves  14  can be defined in the mold plate  10 . 
         [0014]    The gate inserts  20  are fixedly received in the receiving grooves  13 . Each gate insert  20  includes a main portion  21  and two engaging blocks  22  protruding from two opposite sides of the main portion  21 . The main portion  21  is substantially rectangular. The main portion  21  includes a top surface  211 , a bottom surface  212  opposite to the top surface  211 , a first side surface  213 , a second side surface  214  opposite to the first side surface  213 , a first end surface  215 , and a second end surface  216  opposite to the first end surface  215 . The main portion  21  defines an extending runner  211   a  in the top surface. An end of the extending runner  211   a  passes through the first end surface  215 , and the other end of the extending runner  211   a  extends to the second end surface  216  and is a predetermined distance from the second end surface  216 . The main portion  21  defines a gate  216   a  in the second end surface  216 . The gate  216   a  extends from the second end surface  216  to the extending runner  211   a  and communicates with the extending runner  211   a . The gate  216   a  serves as a passage for allowing the melted injection material to enter into the cavity  12  from the runner portion  11 . In this embodiment, the gate  216   a  extends in a direction inclined to an extending direction of the extending runner  211   a , and an opening of the gate  216   a  at the second end surface  216  is closer to the bottom surface  212 , therefore, a sharp edge  216   b  is formed on the gate insert  20 . In detail, the sharp edge  216   b  hangs over the bottom surface  212 . The engaging blocks  22  are formed on the first side surface  213  and the second side surface  214 . Each engaging block  22  defines a through hole  221  corresponding to a connecting hole  15 . In this embodiment, each gate insert  20  is fixed in a receiving groove  13  by two bolts  30  through the connecting holes  15  and the through holes  221 . 
         [0015]    Referring to  FIG. 4 , in assembly, each of the gate inserts  20  is received in a respective one of the receiving grooves  13 , and each of the engaging blocks  22  is engaged into a respective one of the engaging grooves  14 . Each extending runner  211   a  is aligned with a secondary runner  112 . A bolt  30  is inserted into a through hole  221  and is screwed into a connecting hole  15 , thus fixing the gate insert  20  into the receiving groove  13 . 
         [0016]    In use, the mold plate  10  can mold products in cooperation with a mating mold plate (not shown) of the injection mold  100 . Melted injection material is injected into the injection mold  100  by an injection machine (not shown). The melted injection material flows along the main runner  111 , the secondary runners  112 , the extending runner  211   a , and finally enters into the cavities  12 . Then, products with predetermined shape(s) can be molded. The molded products can be ejected out of the cavities  12  by an ejection mechanism (not shown). During the ejecting of the molded products, the sharp edge  216   b  of each gate insert  20  cuts a molded product cleanly from the material in the runner portion  11  and the gate insert  20 , therefore, a cutting process of the molded product after the ejection process is eliminated. 
         [0017]    If the gate  216   a  of a specific gate insert is enlarged beyond an allowable limit, only the specific gate insert  20  needs to be replaced by a new one and, therefore, the mold plate  10  can be repaired. 
         [0018]    It is believed that the present embodiments and their advantages will be understood from the foregoing description, and it will be apparent that various changes may be made thereto without departing from the spirit and scope of the disclosure or sacrificing all of its material advantages, the examples hereinbefore described merely being preferred or exemplary embodiments of the disclosure.