JPH08118300A - Manufacture of split bearing - Google Patents

Abstract

PURPOSE: To reduce the working precision of a bearing hole in the manufacture of a rolling bearing, by setting each of the circular outer peripheral surface of a jig superposed body and the circular inner peripheral surface of a bearing hole to a taper shape set along each other, in the state where the jig superposed body is fitted with the bearing hole. CONSTITUTION: A bearing hole 3 is formed before the brittle fracture at the large end part 2 of a connecting rod, and a circular inner peripheral surface 4 having the center line 3a is formed inside the bearing hole 3. The inner peripheral surface 4 is formed to a taper shape having an angle θ for the center line 3. While, a jig superposed body 5 is constituted to a semicircular half- divided structure. The outside is formed into a semicircular outer surface 8 having the center line 5a of the jig superposed body which is positioned on the center line 10a of a punch 10, as center. The semicircular outer surface 8 is formed into a taper having an angle θ for each of the center lines 5a and 10a. Since the tilt angle of each taper of the bearing hole 3 and the jig superposed body 5 is set equal, the error of the inside diameter of the bearing hole 3 can be absorbed by the relative shift between both.

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 through a piston pin, and to a rotating crankshaft to a crankshaft. The present invention relates to a connecting rod (connecting rod or connecting rod) connected at a large end via a pin, and relates to a method for 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 Laid-Open No. 6-91438, a main body side breaking jig having a semicircular outer peripheral surface and a lid side breaking jig have a semicircular outer circumference. As a jig polymer that is superposed so as to form a circular outer peripheral surface with a surface, it is inserted into the bearing hole at the large end, and the circular outer peripheral surface of this jig polymer and the circular inner peripheral surface of the bearing hole contact each other. Contact. A wedge punch is driven between the jigs, and the semi-circular outer peripheral surfaces of the two jigs, which are separated from each other, cause an impact load on the circular inner peripheral surface of the bearing hole. Brittle fracture with the bearing part.

[0003]

By the way, at the time of such breakage, 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. Should be added uniformly.

However, in the state where the polymer by both the jigs is inserted in the bearing hole, the circular outer peripheral surface of the jig polymer and the bearing centered on the center line of the bearing hole (center line of the jig polymer) and the bearing. Since the circular inner peripheral surfaces of the holes are parallel to their center lines and the diameters of the circular outer peripheral surface and the circular inner peripheral surface are constant, in order to manage the above-mentioned clearance in a good state, the bearing hole It is necessary to perform highly accurate processing on the circular inner peripheral surface of.

According to the present invention, the shape of the outer peripheral surface of both jigs and the shape of the inner peripheral surface of the bearing hole which matches the shape are improved so that the inner peripheral surface of the bearing hole does not need to be machined with high precision. It is intended to provide a manufacturing method.

[0006]

In the method of manufacturing a split bearing according to the first aspect of the present invention, first, a taper in which a circular inner peripheral surface of a bearing hole before fracture to be a split bearing is inclined with respect to a center line of the bearing hole. A jig polymer having a semi-circular outer peripheral surface is overlapped, and the circular outer peripheral surface of the jig polymer is tapered so as to be 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 both jigs of the jig polymer are separated from each other in a direction orthogonal 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. Break the bearing hole.

In the split bearing manufacturing method according to the second aspect of the invention, the inclination angle of the tapered circular inner peripheral surface of the bearing hole before breakage in the first aspect of the invention is determined by the draft angle of the 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 brought into pressure contact with the tapered circular inner peripheral surface formed by the relief gradient.

[0008]

In the first aspect of the present invention, the jig polymer is inserted into the bearing hole, and 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 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. It is possible to manage the clearance between the circular inner peripheral surface and the circular outer peripheral surface in an appropriate state without increasing the height, and to apply a uniform impact load to the bearing hole to cause brittle fracture.

Further, in the second aspect of the invention, the circular inner peripheral surface after molding by the mold can be used as it is as the tapered circular inner peripheral surface of the bearing hole, and the relief gradient thereof is as it is, the inclination angle of the tapered circular inner peripheral surface. become.

[0010]

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

A bearing hole 3 is formed in the large end portion 2 of the connecting rod 1 before the brittle fracture, and a center line 3a is formed in the bearing hole 3.
A circular inner peripheral surface 4 centered on is formed. 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 main body side breaking jig 6 and a lid side breaking jig 7 which are divided into two semicircular parts. 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 with each other in a circular shape and the wedge punch 10 is inserted into the wedge holes 9, the center line 5a of the jig polymer 5 is formed.
It is located on the center line 10a of the wedge punch 10, and the outer peripheral surfaces 8 of both 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 centerline 5a direction is larger than the length of the tapered circular inner peripheral surface 4 in the centerline 3a direction.

Then, the jig polymer 5 composed of both jigs 6 and 7 is inserted into the bearing hole 3 of the large end portion 2, and the wedge punch 10 is inserted into the wedge hole 9 between the jigs 6 and 7. When they are inserted, their center lines 5a, 3a, 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 surfaces 8 of both jigs 6, 7, and the outer peripheral surfaces thereof. Contact part of 8. In that case, both 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 to form the tapered circular inner peripheral surface 4. The tapered circular outer peripheral surface 8 surely contacts.

In this state, when the wedge punch 10 is driven into the wedge hole 9 (force applying means), the impact load causes
The jigs 6 and 7 are separated from each other in the direction orthogonal to the center lines 3a, 5a, and 10a, and the tapered circular outer peripheral surfaces 8 of the jigs 6 and 7 become the tapered circular inner peripheral surfaces 4 of the bearing holes 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, with the jig polymer 5 inserted in the bearing hole 3, the circular outer peripheral surfaces 8 of both jigs 6 and 7 constituting the jig polymer 5 and the bearing hole 3 are formed. Since the circular inner peripheral surface 4 and the circular inner peripheral surface 4 are set to be tapered along each other, even if there is an error in the inner diameter of the bearing hole 3, the error is generated between the circular inner peripheral surface 4 of the bearing hole 3 and the jig polymer 5. It is absorbed by the relative movement between the circular outer peripheral surface 8 and the clearance between the circular inner peripheral surface 4 and the circular outer peripheral surface 8 is managed in an appropriate state without increasing the precision of the inner diameter of the bearing hole 3 more than necessary. It is possible to apply a uniform impact load to the large end portion 2 and surely break the brittleness.

Further, when the connecting rod 1 is sintered and forged, the precision of the draft angle of the forging can be increased, so that the draft angle is 1 to 1.
If it is set to 10 degrees, the circular inner peripheral surface after the forging can be used as it is as the tapered circular inner peripheral surface 4 of the bearing hole 3. In that case, the slope of the slope becomes the inclination angle θ of the tapered circular inner peripheral surface 4 as it is. Therefore, after forging, the bearing hole 3
It is not necessary to machine the circular inner peripheral surface 4 of.

[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 not processed with high precision. The clearance between them can be managed in an appropriate state, and a uniform shock load can be applied to the bearing hole to reliably break the bearing hole.

Further, in the second invention, in addition to the effect of the first invention, the circular inner peripheral surface after molding by the mold can be used as it is as the tapered circular inner peripheral surface of the bearing hole, and the circular inner peripheral surface of the bearing hole can be used. Eliminates the need for processing.

[Brief description of drawings]

FIG. 1 (a) is a front view showing a state where 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 expanded 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.

Claims (2)

[Claims] 1. A split bearing is formed by forming a circular inner peripheral surface of a bearing hole before fracture into a tapered shape inclined with respect to a center line of the bearing hole, and stacking two jigs having a semicircular outer peripheral surface. The circular outer peripheral surface of the jig polymer is formed into a taper shape that is inclined with respect to the center line of the jig polymer, and then this jig polymer is inserted into the bearing hole to form the circular outer circumference of the jig polymer. The surfaces are made contactable along the circular inner surface of the bearing hole, and a force is applied so that both jigs of this jig polymer are separated from each other in the direction orthogonal to the center line of the bearing hole. A method for manufacturing a split bearing, wherein the circular outer peripheral surface of the united body is pressed against the circular inner peripheral surface of the bearing hole to fracture the bearing hole. 2. The inclination angle of the tapered circular inner peripheral surface of the bearing hole before breakage according to claim 1 is made equal to the inclination angle of the die drop gradient given at the time of molding of this bearing hole, and can be formed by the draft angle. A method for manufacturing a split bearing, wherein a tapered circular outer peripheral surface of a jig polymer is brought into pressure contact with a tapered circular inner peripheral surface.