JP3173301B2 - Split bearing manufacturing method - Google Patents

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a reciprocating engine, such as an internal combustion engine, which is connected to a reciprocating piston at a small end via a piston pin and to a rotating crankshaft. The present invention relates to a connecting rod (connecting rod or connecting rod) connected at a large end through a pin, and relates to a method of manufacturing a split bearing by breaking the large end of the connecting rod.

[0002]

2. Description of the Related Art In a conventional split bearing manufacturing method disclosed in Japanese Patent Application Laid-Open No. 6-91438, a body-side breaking jig and a lid-side breaking jig having a semicircular outer peripheral surface are provided on the semicircular outer periphery. The jig polymer is inserted into the bearing hole at the large end as a jig polymer superposed so as to form a circular outer peripheral surface, and the circular outer peripheral surface of the jig polymer and the circular inner peripheral surface of the bearing hole abut each other. Touch A wedge punch is driven between the two jigs, and the semi-circular outer peripheral surfaces of the two jigs separated from each other are subjected to an impact load applied to the circular inner peripheral surface of the bearing hole. It is configured to be brittlely broken with the bearing.

[0003]

At the time of such a break, the clearance between the circular outer peripheral surface of the jig polymer and the circular inner peripheral surface of the bearing hole is made as small as possible, and the impact load is applied to the circular inner peripheral surface. Must be added uniformly.

However, in a state where the polymer of the two jigs is inserted into the bearing hole, the circular outer peripheral surface of the jig polymer and the bearing are centered on the center line of the bearing hole (center line of the jig polymer). Because the circular inner peripheral surface of the hole is parallel to their center line and the diameters of the circular outer peripheral surface and the circular inner peripheral surface are constant, it is necessary to maintain the above-mentioned clearance in a good state by using a bearing hole. It is necessary to perform high-precision processing on the circular inner peripheral surface of the above.

According to the present invention, there is provided a split bearing which does not require high-precision machining of the inner peripheral surface of the bearing hole by improving the shape of the outer peripheral surface of both jigs and the shape of the inner peripheral surface of the bearing hole. It is intended to provide a manufacturing method.

[0006]

In the method for manufacturing a split bearing according to the first invention, the split bearing is separated by breaking.
In manufacturing, first, a circular inner peripheral surface of a bearing hole before fracture, which becomes a split bearing, is formed in a tapered shape inclined with respect to a center line of the bearing hole, and both jigs having a semicircular outer peripheral surface are overlapped. A circular outer peripheral surface of the jig polymer is formed in a tapered shape inclined with respect to the center line of the jig polymer. next,
The jig polymer is inserted into the bearing hole so that the circular outer peripheral surface of the jig polymer can be contacted along the circular inner peripheral surface of the bearing hole.
Then, a force is applied so that the two jigs of the jig polymer are separated from each other in a direction perpendicular to the center line of the bearing hole, and the circular outer peripheral surface of the jig polymer is pressed against the circular inner peripheral surface of the bearing hole. To break the bearing hole.

In the method for manufacturing a split bearing according to the second invention, the inclination angle of the tapered circular inner peripheral surface of the bearing hole before the fracture in the first invention is determined by a draft angle of a mold given when the bearing hole is formed. The inclination angle is made the same, and the tapered circular outer peripheral surface of the jig polymer is pressed against the tapered circular inner peripheral surface formed by the draft angle. Split axis according to the third invention
In the manufacturing method of the bearing, it is formed on the connecting rod as a split bearing
That are being targeted.

[0008]

In the first aspect of the present invention, with the jig polymer inserted into the bearing hole, the circular outer peripheral surface of the jig polymer and the circular inner peripheral surface of the bearing hole are set to be tapered along with each other. So
Even if there is an error in the inner diameter of the bearing hole, the error is absorbed by the relative movement between the circular inner peripheral surface of the bearing hole and the circular outer peripheral surface of the jig polymer, and the accuracy of the inner diameter of the bearing hole is more than necessary. without increasing the manage the clearance between the circular inner peripheral surface and the circular outer peripheral surface in a suitable condition, it can be brittle fracture by adding a uniform shock load to the bearing hole.

Further, in the second invention, the circular inner peripheral surface formed by the mold can be used as it is as the tapered circular inner peripheral surface of the bearing hole, and the slope of the tapered circular inner peripheral surface can be used as it is. become. In the third invention,
A split bearing is formed on the connecting rod.

[0010]

DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS A method for manufacturing a split bearing according to one embodiment of the present invention will be described below with reference to the drawings.

Before the brittle fracture, a bearing hole 3 is formed in the large end 2 of the connecting rod 1, and a center line 3 a is formed in the bearing hole 3.
Is formed at the center. The circular inner peripheral surface 4 has a tapered shape and is inclined by an angle θ with respect to the center line 3a.

The jig polymer 5 is composed of a body-side breaking jig 6 and a lid-side breaking jig 7 divided into two semicircular shapes. A surface 8 is formed, and a wedge hole 9 is formed inside the jigs 6 and 7.
Are formed. When the jigs 6 and 7 are overlapped in a circular shape and the wedge punch 10 is inserted into the wedge holes 9, the center line 5 a of the jig polymer 5 is formed.
The jig 6 is located on the center line 10a of the wedge punch 10, and the outer peripheral surfaces 8 of the jigs 6 and 7 have a circular shape centered on the center lines 5a and 10a. The circular outer peripheral surface 8 has a tapered shape and is inclined by an angle θ with respect to the center lines 5a and 10a. The inclination angle θ of the tapered circular outer peripheral surface 8 and the inclination angle θ of the tapered circular inner peripheral surface 4 of the bearing hole 3 are equal to each other. The length of the tapered circular outer peripheral surface 8 in the center line 5a direction is larger than the length of the tapered circular inner peripheral surface 4 in the center line 3a direction.

A jig polymer 5 composed of the jigs 6 and 7 is inserted into the bearing hole 3 of the large end 2 and a wedge punch 10 is inserted into a wedge hole 9 between the jigs 6 and 7. When they are inserted, their center lines 5a, 3a and 10a coincide with each other, and the tapered circular inner peripheral surface 4 of the bearing hole 3 becomes parallel to the tapered circular outer peripheral surface 8 of both jigs 6 and 7, and the same outer peripheral surface 8 touches a part. In this case, the jigs 6 and 7 relatively move in a direction along the center lines 5a, 3a and 10a or in a direction orthogonal to the center lines 5a, 3a and 10a in accordance with the inner diameter error of the bearing hole 3, and the tapered circular inner peripheral surface 4 The tapered circular outer peripheral surface 8 is securely contacted.

In this state, when the wedge punch 10 is driven into the wedge hole 9 (force applying means), the impact load causes
The two jigs 6 and 7 are separated from each other in a direction orthogonal to the center lines 3a, 5a and 10a, and the tapered circular outer peripheral surfaces 8 of the two jigs 6 and 7 are formed on the tapered circular inner peripheral surface 4 of the bearing hole 3. Crimped,
The large end 2 is brittlely broken into the main body side bearing portion 2a and the lid side bearing 2b.

Particularly, in this embodiment, the jig polymer 5 is inserted into the bearing hole 3 and the circular outer peripheral surfaces 8 of the jigs 6 and 7 constituting the jig polymer 5 and the bearing hole 3 Are set in a tapered shape along with each other, even if there is an error in the inner diameter of the bearing hole 3, the error is caused by the difference between the circular inner peripheral surface 4 of the bearing hole 3 and the jig polymer 5. The clearance between the circular inner peripheral surface 4 and the circular outer peripheral surface 8 is managed in an appropriate state without being unnecessarily enhanced by the relative movement between the circular outer peripheral surface 8 and the inner diameter of the bearing hole 3. it can, can be reliably brittle fracture by adding a uniform <br/> shock load to the large end portion 2.

When the connecting rod 1 is sintered and forged, the accuracy of the draft angle of the forging can be increased.
If it is set to 10 degrees, the circular inner peripheral surface after forging can be used as it is as the tapered circular inner peripheral surface 4 of the bearing hole 3. In that case, the draft angle becomes the inclination angle θ of the tapered circular inner peripheral surface 4 as it is. Therefore, after forging, the bearing hole 3
There is no need to machine the circular inner peripheral surface 4.

[0017]

According to the first aspect of the present invention, the tapered circular inner peripheral surface of the bearing hole and the tapered circular outer peripheral surface of the jig polymer are formed without performing high-precision machining on the tapered circular inner peripheral surface. manage the clearance between the the proper state, it is possible to reliably break the addition of uniform shock load to the bearing hole.

Further, in the second invention, in addition to the effect of the first invention, the circular inner peripheral surface of the bearing hole can be used as it is as the tapered circular inner peripheral surface of the bearing hole. It is not necessary to process the steel.

[Brief description of the drawings]

FIG. 1A is a front view showing a state in which a jig polymer is inserted into a bearing hole before breaking at a large end portion of a connecting rod;
(B) is an XX line partial enlarged sectional view of (a).

[Explanation of symbols]

DESCRIPTION OF SYMBOLS 1 ... Connecting rod, 2 ... Large end part, 3 ... Bearing hole, 4 ... Tapered circular inner peripheral surface, 5 ... Jig polymer, 6, 7 ... Jig, 8 ... Tapered circular outer peripheral surface, 10 ... Wedge Punch, θ ... inclination angle.

Continued on the front page (58) Fields surveyed (Int. Cl. ⁷ , DB name) B26F 3/02 F16C 3/06 F16C 7/02 F16C 9/02 F16C 9/04 B21D 53/84

Claims (3)

(57) [Claims] 1. A method of manufacturing a split bearing by breaking and separating.
In the method, the circular inner peripheral surface of the bearing hole before fracture to be a split bearing is formed in a tapered shape inclined with respect to the center line of the bearing hole, and both jigs having a semicircular outer peripheral surface are overlapped. The circular outer peripheral surface of the jig polymer is formed in a tapered shape inclined with respect to the center line of the jig polymer, and then the jig polymer is inserted into a bearing hole to form a circular outer periphery of the jig polymer. The surface of the jig polymer is made contactable along the circular inner peripheral surface of the bearing hole, and a force is applied so that both jigs of the jig polymer are separated from each other in a direction perpendicular to the center line of the bearing hole. A method of manufacturing a split bearing, wherein a circular outer peripheral surface of a united body is pressed against a circular inner peripheral surface of a bearing hole to break the bearing hole. 2. The inclination angle of the tapered circular inner peripheral surface of the bearing hole before the fracture in claim 1 is made equal to the inclination angle by the draft angle of the mold given at the time of molding the bearing hole, and the inclination angle can be obtained. A method of manufacturing a split bearing, wherein a tapered circular outer peripheral surface of a jig polymer is pressed against a tapered circular inner peripheral surface. 3. The split bearing is formed on a connecting rod.
The split bearing according to claim 1 or 2, wherein
Manufacturing method.