Abstract:
A device for breaking and dividing an enlarged bearing portion of a connecting rod into a main body portion and a bearing cap portion includes a split mold which is insertable into an aperture in the enlarged bearing portion. A pressing mechanism includes pressure caps engaging dramatically opposite points on the outer surface of the enlarged bearing portion at locations where the beating portion is to be broken and divided when a wedge is forced into the split mold.

Description:
TECHNICAL FIELD OF THE INVENTION 
     The present invention relates to a pressurizing mechanism for a con&#39;rod (connecting rod) used in a breaking and dividing device (fracture process) for the connecting rod of an internal combustion engine or the like. 
     DESCRIPTION OF THE PRIOR ART 
     The process of breaking and dividing a connecting rod, hereinafter referred to as a con&#39;rod, as follows: As shown in FIG. 5, a con&#39;rod  1  is made in prior art in such a way that a con&#39;rod main body  2  and a bearing cap portion  3  are formed as one piece, for example, by sinter forging, and a notch  5   a  is made in a face which is to be divided. This face is on the inner surface of a bearing portion  5  on a large end portion  4  of the con&#39;rod. 
     A small end portion of the con&#39;rod  1 , as shown in FIG.  5  and FIG. 6, is fitted onto a small end reference pin  12  carried on a support stand  11 . Left and right seats  3   a  of the bearing cap portion  3  are mounted on a movable plate  14  on the bearing cap portion side of the large end portion  4 . The plate  14  is located face to face with a stationary plate  13  which is on the main body side of the large end portion  4  and both plate  13  and plate  14  are on the support stand  11 . Tips  15   a  of a movable pressing portion  15  are pressed to be in contact with seats  3   a.  Further, on the stationary plate  13  on the main body side, an escaping force receiving pin  16  is mounted so as to be in contact with a part of a shoulder  4   a  formed on the bearing cap portion  3  of the large end portion  4  of the con&#39;rod  1 . When the con&#39;rod is so mounted on platform  11 , a wedge  18  is forced into a split mold  17  fitted into the bearing portion  5  on the large end portion side, and consequently, the main body  2  and the bearing cap portion  3  are broken and divided at the notch  5   a.  Furthermore, reference numeral  19  denotes a guide plate for the movable plate  14 , which is fixed on the support stand  11 . 
     A mechanism in which the notch  5   a  is automatically formed so that breaking and dividing may securely be performed has been disclosed in Japanese Laid-Open Patent Application No. H6-91438. As described in that application, left and right expansion molds (a split mold) are provided face to face in the direction in which the main body and the bearing cap portion are to be separated from each other, in a large end hole, or bearing portion. A punch or wedge to be forced into a mid position thereof is provided, and breaking chips arranged with the tips facing to the inner surface of the large end hole bearing portion are provided at both ends at right angles to the direction in which the bearing cap portion is broken and separated by the punch. By forcing the punch (wedge), a load in the breaking and separating direction is given to the bearing cap portion or the like, and at the same time, the breaking chips  14  and  15  cause a concentrated load to be applied to the portion to be broken and separated. Accordingly, the part to be broken and separated can easily be deformed, and it is possible to securely make this part the breaking start point, and in the meantime, this can automatically be performed with no trouble by forcing the punch. 
     However, in a mechanism like the one described in the Publication, in which a notch is not formed in advance and a concentrated load is applied to the portion to be broken and separated by breaking chips from the inside of the large end hole (bearing portion) by utilizing the forcing of the punch (wedge) for giving a load in the breaking and separating direction to the bearing cap portion or the like, this concentrated load is applied suddenly in some cases, and therefore as shown in FIG. 7, the breaking and separating (dividing) are finished in the state shown by A, B where the breaking and separating are deviating from the line a—a passing through the face to be broken and divided in some cases, and there are some cases where it cannot be used as a con&#39;rod. 
     SUMMARY OF THE INVENTION 
     The present inventors have found as a result of research that the breaking and dividing of a con&#39;rod can be performed precisely at the face to be broken and divided and with only a small deformation, by performing the breaking and dividing while applying force to points on the outside of the bearing cap portion of the large end portion of a con&#39;rod, and have reached the present invention. 
     It is an object of the present invention to provide a pressurizing mechanism for breaking and dividing a con&#39;rod, in which a wedge is forced through a split mold into a bearing portion on the large end portion side of a con&#39;rod made in such a way that the bearing cap portion included in the large end portion and the main body side to be connected to the cap portion are manufactured as one piece. Breaking and dividing the main body and the bearing cap portion is performed so that the main body and the bearing cap portion may be broken and divided precisely at the face to be broken and divided, and further, the deformation at that moment can be made minimum. 
     In order to achieve the above object, a pressurizing mechanism of the con&#39;rod breaking and dividing device of the present invention includes a mechanism to press a point to be broken and divided on the outside of the large end portion of the con&#39;rod. In addition, a wedge is forced through a split mold into a bearing portion on the large end portion side of a con&#39;rod made in such a way that a bearing cap portion included in the large end portion and a main body side to be connected to the cap portion are formed as one piece so as to break and divide the main body and the bearing cap portion. 
    
    
     BRIEF DESCRIPTION OF THE DRAWINGS 
     FIG. 1 is a plan view showing one embodiment of a pressurizing mechanism of a con&#39;rod breaking and dividing device of the present invention. 
     FIG. 2 is a front view showing one embodiment of a pressurizing mechanism of a con&#39;rod breaking and dividing device of the present invention. 
     FIG. 3 is a plan view showing one embodiment of con&#39;rod breaking and dividing device to which a pressurizing mechanism of the present invention is assembled. 
     FIG. 4 is a front view showing one embodiment of a con&#39;rod breaking and dividing device shown in FIG.  3 . 
     FIG. 5 is a plan view of the main part of a con&#39;rod breaking and dividing device having no pressurizing mechanism. 
     FIG. 6 is a cross sectional view of a main part of a con&#39;rod breaking and dividing device shown in FIG.  5 . 
     FIG. 7 is a plan view showing one embodiment of a con&#39;rod in which breaking and dividing are not performed at a face to be broken and divided. 
    
    
     DETAILED DESCRIPTION 
     The present invention will be described in detail with reference to FIG. 1 to FIG.  4 . In FIG. 1 to FIG. 4, reference numeral  20  denotes a pressurizing mechanism of the present invention, and first, this will be described by using FIG.  1  and FIG. 2 showing only the mechanism. The present pressurizing mechanism is arranged on a pair of support blocks  21  fixed in parallel on a support stand  11 . Between the pair of support blocks  21  on the support stand  11 , a large end portion  4  of a con&#39;rod  1  is fixed such that the line a—a passing through the face to be broken and divided is at right angles to the support block  21 . At the corresponding position of the support block  21  on the extension of the line a—a, a screw hole  21   a  is formed from the outside and a pressurizing bolt  22  is screwed in. At the tip of the bolt, an angle pressurizing cap  24  whose tip faces and contacts the face to be broken and divided is attached through a rotatable rod  23 . The rod  23  can be connected to a hydraulic operating cylinder (not shown in the figure) instead of the pressurizing bolt  22 , if desired. 
     FIG.  3  and FIG. 4 show a con&#39;rod breaking and dividing device  30  to which the pressurizing mechanism  20  of the present invention is assembled. In the longitudinal direction of a support stand  31 , a pair of guide rails  33  are fixed to the support stand  31  through pressing plates  32  by bolts  34 . A stationary plate  35  on the con&#39;rod main body side and a movable plate  36  on the bearing cap side are arranged so that they may be caught between the pair of guide rails  33  and may stand face to face. 
     Reference numeral  37  denotes a split mold, with half-round left and right portions  37   a,    37   b  arranged between the stationary plate  35  and the movable plate  36  formed like a half circle to be in accord with the body portion of the spilt mold  37 . A flange portion  37   c  formed at the lower end thereof is free, but a similar flange portion  37   d  thereof is fixed to the movable plate  36  by a small bolt  38  or a knock pin. Furthermore, a wedge hole  39  in which a wedge  18  is forced is formed in split mold  37 , and the hole  39  is vertical at the left portion  37   a  in FIG.  3  and FIG. 4, but it is inclined to fit with the shape of the wedge  18  at the right portion  37   b.  The flange portions  37   c,    37   d  in the split mold  37  are movably fitted into an elliptic hollow  31   a  formed in the upper surface of the support stand  31 . 
     Reference numeral  40  denotes a small end reference pin mounted at a specified position of the support stand  31  to which a small end portion  6  of the con&#39;rod  1  is fitted, and around it, an adjusting ring  41  is provided for keeping the con&#39;rod  1  horizontal. 
     Reference numeral  42  denotes a pressing mechanism on the bearing cap portion side to press the bearing cap portion  3  of the con&#39;rod  1 . The pressing mechanism is arranged on the movable plate  36 , and is composed such that a length adjusting bolt  46  is screwed at both ends of a support plate  45  attached to the tip of a rod  44  of, for example, a hydraulic operating cylinder  43 . Bolt  46  is fixed by an adjusting nut  47 , and at the tip of the bolt  46 , a pressing hardware  48  in contact with left and right seats  3   a  of the bearing cap portion  3  is attached. 
     Reference numeral  49  denotes a clamping plate having a width a little narrower than the width of the large end portion  4  of the con&#39;rod  1 , and in the one shown in the figure, on the side to be in contact with the large end portion  4  of the con&#39;rod  1 , a semicircular concave portion  49   a  is formed in accord with the bearing portion  5 . On the opposite side thereof, an elongated hole  49   b  is formed which can be fitted onto a clamping support pin  50  mounted at a specified position of the support stand  31 . 
     The clamping plate  49  is composed to be pressed from above in FIG. 4, for example, by a hydraulic operating cylinder (not shown in the figure) so as to be fixed, when breaking and dividing the con&#39;rod. 
     In the embodiment of FIG.  3  and FIG. 4, the pressurizing mechanism of the present invention is composed such that a concave portion  32   a  is formed at a part facing to the opposite part (portion to be broken and divided) of the left and right portions  37   a,    37   b  of the split mold  37 ; that is, at the corresponding positions of the presser plates  32  on the extension of the line a—a passing through the face to be broken and divided, in the pair of presser plates  32  in the con&#39;rod breaking and dividing device  30 . In the concave portion  32   a,  an angle pressurizing cap  51  whose tip is facing to the opposite part is slidably arranged so that the cap  51  can be advanced and retreated by a pressurizing bolt  53  connected to the presser plate  32  by a screw, through a rod  52  rotatably connected to the rear thereof. 
     Next, the operation of the pressurizing mechanism of the con&#39;rod breaking and dividing device of the present invention which is composed as mentioned above will be described by being included in the operation of the con&#39;rod breaking and dividing device. 
     First, after fixing the support stand  31  in the con&#39;rod breaking and dividing device (by a mechanism not shown in the figure), the support plate  45  is lowered to the right in FIG. 3 by the operating cylinder  43  of the pressing mechanism  42  on the bearing cap side in advance. Moreover, the pressurizing bolt  53  of the pressurizing mechanism of the present invention is turned in the loosening direction, and the pair of pressurizing caps  51  are lowered in advance. 
     In this state, as shown in FIG. 3, the small end portion  6  of the con&#39;rod  1  and the bearing portion  5  on the large end portion side are respectively fitted and seated onto the small end reference pin  40  and the split mold  37 . In the inner surface of the bearing portion  5  of the con&#39;rod  1 , notches  5   a  are formed in advance in the face to be broken and divided in accord with the opposite parts of the left and right portions  37   a,    37   b  of the split mold  37 . 
     The support plate  45  is advanced to the left in FIG.  3  and FIG. 4 by the operating cylinder  43  of the pressing mechanism  42  on the bearing cap side, and the pressing hardware  48  of the mechanism  42  is pressed to be in contact with the left and right seats  3   a  of the bearing cap portion  3 . 
     Furthermore, the pressurizing bolt  53  of the pressurizing mechanism of the present invention is turned, and the pressurizing cap  51  is advanced in the concave portion  32   a  by way of the rod  52 , and the tip of the cap  51  is pressed to be in contact with the outside of the large end portion  4  at a location corresponding to the notch  5   a  in the con&#39;rod  1  and a specified force (about 1 kgf-m) is applied. 
     Next, the elongated hole  49   b  of the clamping plate  49  is fitted onto the clamping support pin  50 , and while performing adjustment by using the elongated hole  47   b,  the concave portion  47   a  on the opposite side is brought into contact with the left portion  37   a  of the split mold  37 . In this state, the clamping plate  49  is pressed from above and fixed by the operating cylinder (not shown in the figure) or the like. 
     Here, as shown in FIG.  3  and FIG. 4, if the wedge  18  is forced into the wedge hole  39  of the split mold  37  by pressurizing means (not shown in the figure), the bearing cap portion  3  is broken and divided from the face to be broken and divided, and it separates from the main body side and moves together with the right portion  37   b  of the split mold  37  and the movable plate  36  on the bearing cap side, while making the support plate  45  of the pressing mechanism  42  on the bearing cap side or the like retreat to the right. 
     At this moment, a crack caused from the notch  5   a  rapidly progresses while being directed to the pressurizing point at the tip of the cap  51  of the pressurizing mechanism of the present invention, and the bearing cap portion  3  is broken and divided along the line a—a passing through the face to be broken and divided. Furthermore, at this moment, the deformation near the bearing portion  5  is small. 
     Therefore, in the pressurizing mechanism of the con&#39;rod breaking and dividing device according to the present invention, when a wedge is forced into the bearing portion on the large end portion side through the split mold to break and divide the main body and the bearing cap portion, the directing thereof is performed so that the main body and the bearing cap portion can be broken and divided precisely at the face to be broken and divided, and in the meantime, there is such an effect that breaking and dividing are easily performed so that the deformation near the bearing portion can be made minimum. 
     EXPLANATION OF REFERENCE NUMERALS 
       1 : con&#39;rod 
       2 : main body 
       3 : bearing cap portion 
       4 : large end portion 
       5 : bearing portion 
       5   a:  notch 
       6 : small end portion 
       11 ,  31 : support stand 
       12 ,  40 : small end reference pin 
       13 ,  35 : stationary plate on the con&#39;rod main body side 
       14 ,  36 : movable plate on the bearing cap portion side 
       15 : movable pressing portion 
       16 : escaping force receiving pin 
       17 : split mold 
       18 : wedge 
       19 : guide plate 
       20 : pressurizing mechanism 
       21 : support block 
       22 ,  53 : pressurizing bolt 
       23 ,  52 : rod 
       24 ,  51 : pressurizing cap 
       32 : presser plate 
       33 : guide rail 
       34 : bolt 
       38 : small bolt 
       39 : wedge hole 
       41 : adjusting ring 
       42 : pressing mechanism on the bearing cap portion side 
       43 : hydraulic operating cylinder 
       44 ,  52 : rod 
       45 : support plate 
       46 : adjusting bolt 
       47 : adjusting nut 
       48 : pressing hardware 
       49 : clamping plate 
       50 : support pin