JP3334180B2 - 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 method of manufacturing a split bearing by break-separation, and more particularly to a method of manufacturing a split bearing capable of reliably controlling the starting point of break.

[0002]

2. Description of the Related Art A large end portion of a connecting rod of an internal combustion engine is constituted by a split bearing divided into two parts in an axial direction.
6 and 7 show an example of a conventional method for manufacturing a split bearing. As shown in FIG. 6, a V-shaped groove 3 and a U-shaped groove 4 are first formed on the large end 2 of the connecting rod 1 by press working or the like. The V-shaped groove 3 is formed on the inner peripheral surface side of the large end 2, and the U-shaped groove 4 is formed on the outer peripheral surface side of the large end 2.

[0003] The connecting rod 1 having the V-shaped groove 3 and the U-shaped groove 4 formed therein is set in a break-away mold 5 shown in FIG. The break separation mold 5 includes a left expansion die 5a, a right expansion die 5b , and a wedge 5c. In a state where the large end hole 2a of the large end portion 2 of the connecting rod 1 is fitted to the left expansion type 5a and the right expansion type 5b of the break separation mold 5, a gap between the left expansion type 5a and the right expansion type 5b. When the wedge 5c is driven into the large end 2, a load is applied to the large end 2 in the breaking and separating direction (the direction of the arrow) due to the wedge effect.

When the wedge 5c is driven and a load is applied to the large end 2 in the breaking and separating direction, the fracture starts from the V-shaped groove 3 and the large end 2 is divided into two parts. A split bearing is formed by dividing the large end 2 into two parts. As one of prior arts of such a split bearing, for example, Japanese Patent Application Laid-Open No. 64-64729 is known.

[0005]

However, in the case of a structure in which a V-shaped groove or the like is formed at a portion where break separation is to be performed as described above and a starting point of the break is formed, stress is not necessarily concentrated on the V-shaped groove or the like. However, breakage may occur at unintended locations. Therefore, there is a problem that it cannot be used as a split bearing depending on the position of the fractured surface. In addition, in the case of such a manufacturing method, it is necessary to form a V-shaped groove or the like in a step prior to the break separation operation, and there is a problem that the number of processing steps increases.

The present invention aims to provide a fracture origin can be reliably controlled, yet fewer manufacturing method of split bearing capable of fracture splitting the bearing by the machining process.

[0007]

A method of manufacturing a split bearing according to the present invention for achieving this object is as follows.
You. A method of manufacturing a split bearing according fracture separation the bearing
Press the breaking tip against the site of the material
The part to be fractured of the receiving material
Applying a concentrated load, perpendicular to the fracture separation direction
Direction load on the part of the bearing material
By applying a load in the fracture separation direction to the bearing material by
Breaking and separating the bearing material at the break-separation-scheduled site,
Manufacturing method of bearings.

[0008]

In the manufacturing method of the split bearing having the above structure , the load in the direction perpendicular to the breaking and separating direction is applied to the bearing material.
To the bearing material by the extended type
Breaking of bearing material by applying load in the breaking and separating direction
In so broken to separate, breaking stress is concentrated on the separation proposed site, it is possible to reliably break starting from the site of this. Also, without V-groove or U-groove processing,
Control the fracture origin by applying a load in the direction perpendicular to the
Roll to Runode, conventional processing steps is reduced productivity as compared with the method is increased.

[0009]

DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS Preferred embodiments of the method for manufacturing a split bearing according to the present invention will be described below with reference to the drawings. FIGS. 1 to 5 show an embodiment of the present invention, particularly when applied to a connecting rod of an internal combustion engine. First, a break separation mold for carrying out the present invention will be described.

As shown in FIGS. 1 and 2, a break separation mold 10 includes a left expansion die 11, a right expansion die 12, a punch 13,
It has a left breaking tip 14 and a right breaking tip 15. The left expansion type 11 and the right expansion type 12 are slidably held on a base (not shown). The outer surface of the left expandable mold 11 is the large end hole 2 of the large end 2 of the connecting rod 1.
a is formed on the curved surface 11a which can be in close contact with the inner peripheral surface of the a. The inner surface of the left expansion die 11 opposite to the outer surface 11a is formed as an inclined surface 11b.

The outer surface of the right expansion die 12 is formed as a curved surface 12a which can be in close contact with the inner peripheral surface of the large end hole 2a of the large end 2 of the connecting rod 1. An inner surface opposite to the outer surface of the right expansion die 11 is formed on an inclined surface 12b. When the left expansion die 12 and the right expansion die 11 are in close contact with the large end hole 2a, a gap is formed between the inclined surface 11b and the inclined surface 12b that becomes narrower downward.

The inclined surface 11b of the left expansion type 11 and the right expansion type 1
A punch 13 is arranged between the second inclined surface 12b and the second inclined surface 12b. One side surface of the punch 13 is formed as an inclined surface 13 a that can be in close contact with the inclined surface 11 b of the left expansion die 11.
The other side surface of the punch 13 is the inclined surface 12 of the right expansion die 12.
b is formed on the inclined surface 13b which can be in close contact with the b. The distance between the inclined surface 13a and the inclined surface 13b of the punch 13 is small at the bottom and large at the top. That is, the punch 13
Is formed in a wedge shape by two inclined surfaces 13a and 13b.

A guide groove 1 having a U-shaped cross section is formed on a side surface of the punch 13 in a direction perpendicular to the inclined surfaces 13a and 13b.
3c and 13d are formed. Guide grooves 13c, 13
The groove bottom of d is formed on the inclined surfaces 13e and 13f.
A left breaking tip 14 is slidably mounted in one guide groove 13c. A right-breaking tip 15 is slidably mounted in the other guide groove 13d. The left breaking tip 14 and the right breaking tip 15
The connecting rod 1 is disposed so as to be located at the fracture separation scheduled portion F of the large end 2 of the connecting rod 1.

The surface of the left breaking tip 14 facing the groove bottom surface 13e is formed as an inclined surface 14a. The surface facing the groove bottom surface 13f of the right breaking tip 15 is an inclined surface 15a.
Is formed. When the punch 13 is pushed down, the left breaking tip 14 and the right breaking tip 15 slide outwardly (in the direction of the large end hole 2a of the connecting rod 1) by sliding contact with the groove bottom surfaces 13e, 13f of the guide grooves 13c, 13d.
It is designed to protrude. The portions of the left breaking tip 14 and the right breaking tip 15 that can come into contact with the inner peripheral surface of the large end hole 2a of the connecting rod 1 are formed on the projections 14b, 15b that taper toward the tip. .

Next, a method of manufacturing the split bearing according to the present invention and its operation will be described. The connecting rod 1 is set in the break separation mold 10 with the left expansion mold 11 and the right expansion mold 12 of the break separation mold 10 approaching each other. In this state, the left expansion type 11 and the right expansion type 12
, The large end hole 2a of the connecting rod 1 is fitted.

When the fitting of the left expansion die 11 and the right expansion die 12 with the large end hole 2a is completed, the punch 13 is pushed down by the lowering of the ram of a press machine (not shown). Here, both side surfaces of the punch 13 are formed on the inclined surfaces 13a and 13b, and the side surfaces of the left expanding die 11 and the right expanding die 12 are formed on the inclined surfaces 11b and 12b.
12 is spread horizontally. In this state, the large end portion 2 of the connecting rod 1 is bearing a load P ₁ of the fracture separation direction is imparted.

When the punch 13 is lowered, the two extended molds 11,
Prior to the movement of 12, the tip 14 for breaking left and the tip 15 for breaking right protrude toward the inner peripheral surface of the large end hole 2a of the connecting rod 1. If the amount of descent of the punch 13 becomes large, both breaking chips 14 and 15 are now bites into the inner peripheral surface of the large end hole 2a, breaking load P ₂ in the direction perpendicular to the fracture separation direction of the large end portion 2 It is applied intensively to the separation scheduled portion F.

Therefore, the stress is concentrated on the portion F to which the concentrated load is applied by the left breaking tip 14 and the right breaking tip 15 and the breaking is more easily started than the other portions. Therefore, the large end portion 2 is reliably separated and broken by using the portion pressed by the left breaking tip 14 and the right breaking tip 15 as a breaking starting point. As described above, by generating the internal stress intensively at the fracture separation scheduled portion F, the fracture starting point can be reliably controlled.

FIG. 5 shows a change in the expansion amount of the expansion die and the breaking tip with respect to a change in the movement amount of the punch.
In this embodiment, the breaking chips 14, 15 are 0.02 mm.
It is set so that both extended dies 11 and 12 start moving when they move. As can be seen from FIG. 5, for example, if the break of the large end 2 occurs when the movement amount of the punch 13 is 15 mm, the protrusion amount of the breaking chips 14 and 15 at this time is about 0.3 mm. Become.

The extended dies 11 and 12 and the breaking tip 1
As shown in FIG. 1, the relationship between the movements of the tips 4 and 15 is as follows: the distance L ₁ between the outer surfaces of the extended dies 14 and 15;
It can be varied by varying the distance L ₂ and the angle of the inclined surfaces between the protruding portion of 4,15.

The breaking tips 14 and 15 merely determine the starting point of the breaking and are not the breaking itself. Therefore, it is preferable that the amount of the breaking tips 14 and 15 inserted into the large end 2 is as small as possible. Thus, it is possible to reduce the pile Write-amount, upon the addition of a machining on the inner peripheral surface or the like of the large end portion 2 after the deformation portion is easily removed is by biting
It is .

As described above, the application of the concentrated load by the breaking tips 14 and 15 may be performed by elastically deforming the large end 2 or may be performed by minute plastic deformation.

[0023]

According to the present invention, the following effects can be obtained.

[0024] (1) a direction load of the perpendicular to the fracture separation direction while intensively applied to the fracture separation the proposed site of the bearing, the bearing
Since the load in the breaking and separating direction is applied to the wire, the starting point of the breaking can be reliably controlled, and the occurrence of a defective breaking position can be eliminated.

[0025] (2) by the application of load direction orthogonal to the fracture separation direction so to control the fracture starting point,
As compared with the conventional method of forming a V-shaped groove or the like, the number of processing steps is reduced, and the productivity can be improved.

(3) Since a load is applied in a direction perpendicular to the fracture separation direction, it is possible to prevent the bearing inner diameter from being greatly deformed in the fracture separation direction, and to suppress a decrease in the roundness of the bearing inner diameter. can do.

[Brief description of the drawings]

FIG. 1 is a plan view showing a method for manufacturing a split bearing according to one embodiment of the present invention.

FIG. 2 is a sectional view taken along line AA of FIG.

FIG. 3 is a sectional view taken along line BB of FIG. 1;

FIG. 4 is an enlarged plan view showing a state in which a workpiece is pressed by a breaking tip in FIG. 1;

FIG. 5 is a characteristic diagram showing a change in an expanding force of an expanding die and a breaking tip with respect to an amount of movement of a punch in the break separation mold of FIG. 1;

FIG. 6 is a plan view showing an example of a conventional split bearing manufacturing method.

FIG. 7 is a sectional view of a step of breaking and separating the workpiece shown in FIG. 6;

[Explanation of symbols]

2 Large end as bearing 10 Break separation mold 11 Left expansion type 12 Right expansion type 13 Punch 14 Left break tip 15 Right break tip P ₁ Load in break separation direction P ₂ Load in direction perpendicular to break separation direction F fracture planned separation site of bearing

Continuation of the front page (58) Field surveyed (Int.Cl. ⁷ , DB name) B23P 13/00 F16C 7/02 F16C 9/04

Claims (1)

(57) [Claims] 1. A method of manufacturing a split bearing by breaking and separating , wherein a breaking chip is pressed against a portion of a bearing material which is to be broken.
The direction perpendicular to the fracture separation direction at the expected fracture site of the bearing material
In the direction perpendicular to the fracture separation direction.
The bearing material is broken by the expansion type
The bearing material is fractured and separated by applying a load in the breaking and separating direction.
Broken at the proposed site to separate, split Ri method of manufacturing a bearing.