JP3283379B2 - Reference pin for tapering the small end of the connecting rod - Google Patents

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a reference pin for positioning used in a tapering process of a small end portion of a connecting rod (hereinafter, abbreviated as a connecting rod), and more particularly to an inner peripheral surface of a piston pin hole. The present invention relates to an oil hole in which the open end of the oil hole is closed with a reference pin.

[0002]

2. Description of the Related Art A conventional example of tapering a small end of a connecting rod will be described with reference to FIG.

[0003] The connecting rod (10) is a rod-shaped member that connects the crankshaft and the piston of the engine.
The large end (2) is on the crankshaft side and the small end (1) is on the piston side. A connecting portion (3) extending along the longitudinal axis of the connecting rod (10) has an upper portion of the inner peripheral surface of the crankpin hole at the large end (2) and an inner peripheral surface of the piston pin at the small end (1) ( 4) An oil hole (5) communicating with the lower portion is formed so that a sufficient amount of lubricating oil can be distributed to the inner peripheral surface (4) of the piston pin hole of the small end (1) during operation of the engine. The oil hole (5) is always provided because a high compression ratio is adopted particularly in a diesel engine.

[0004] Both sides of the small end (1) are tapered by a rotary blade (8) attached to the tip of a rotary shaft (7) in order to reduce the weight. Connecting rod (1
0) is the support pin (14) of the transfer device (13) with the small end (1) up and the large end (2) down.
Into the piston pin hole (4) at the small end (1),
The connecting portion (3) is conveyed to a transfer position to the fixed blocks (6A) and (6B) while being gripped by a gripping arm (not shown) (see FIG. 2D).

[0005] Connecting rod (10) that has reached the delivery position
The small end (1) is transferred from the support pin (14) to the reference pin (12) of the fixed block (6A), and the large end (2) is supported by the fixed block (6B). After this delivery operation is completed, the side portion (15) of the small end portion (1) of the connecting rod (10) is cut by the rotary blade (8) while spraying the coolant (9) to reduce the weight. (See FIGS. 2A and 2B). When the taper processing is completed on one end face of the small end portion (1), the connecting rod (10) is transferred from the fixed blocks (6A) and (6B) to the support pins (14) of the transfer device (13) again, The position of the cutting surface by the rotary blade (8) is set to 18
It is supplied to the next step in a state where it is inverted by 0 °, and is transferred to another fixed block (6A) (6B). In this state, the other end face of the small end (1) is subjected to the same taper processing as described above.

[0006]

The chips (11) generated when the end face of the small end (1) of the connecting rod (10) is subjected to a taper process are cooled by a coolant sprayed toward the cut surface. It is washed out by (9) and discharged out of the system, but a part enters the piston pin hole (4) at the small end (1),
The oil may enter the oil hole (5) opened on the inner peripheral surface. In order to remove the chips (11), the cleaning liquid is injected into the oil hole (5) from the large end (2) side in a later step.
Since the cuttings (11) have a curl shape or a spring shape, they are in a state where they can easily bite into the wall surface of the oil hole (5). For this reason, even if the cleaning liquid is injected, the discharge of the chips (11) is not complete, and the connecting rod (10) is supplied to the engine assembly process with the chips (11) remaining in the oil hole (5). There is.

If the chips (11) remain in the oil hole (5), the flow of the lubricating oil during the operation of the engine is obstructed, and an accident such as seizure occurs. Also, in the post-step of taper processing,
When the inner peripheral surface (4) of the small end portion (1) is machined with a diamond chip, the cutting chips (11) are rolled up.
Problems such as damage to the inner peripheral surface (4) and breakage of the diamond chip occur.

[0008]

In order to solve the above-mentioned problems, the present invention provides a connecting portion for connecting a small end portion and a large end portion with a piston pin hole at the small end portion and a crank pin hole at the large end portion. A connecting rod formed with an oil hole that communicates with the piston pin protrudes from a fixed block into the piston pin hole with the small end facing upward in the tapering step on both sides of the small end.
In the positioning fixing block for fitting and positioning and fixing the output reference pin, the tip portion of the reference pin is extended to the opening end of the oil hole opened on the inner peripheral surface of the piston pin hole, and the extension portion The open end of the oil hole was closed.

[0009]

Since the opening end of the oil hole is closed by the reference pin of the fixed block, the penetration of chips into the oil hole is completely prevented.

[0010]

DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS An embodiment of the present invention will be described below with reference to FIGS. In the following description, the same components as those in FIG. 2 showing the related art are denoted by the same reference numerals in principle, and the description of the same items will not be repeated.

As shown in FIG. 1A, the fixed block (6A) has, as a basic structure, a reference pin (16) which fits into a hole provided in the small end (1) of the connecting rod (10).
Is extended along the axial direction thereof to the open end of an oil hole (5) opened in the inner peripheral surface of the piston pin hole (4), and this extended portion is connected to the oil hole (5). It functions as a closing member.

As a further preferred embodiment, FIG.
As shown in FIG. 7, the reference pin (16) is formed by extending only the lower portion of the tip portion to the opening end of the oil hole (5) opening below the inner peripheral surface of the piston pin (4). ), The open end on the side of the small end (1) is completely closed, and the upper end of the extension (21) of the reference pin (16) is inclined toward the base end of the reference pin (16). The tip of the reference pin (16) is used as an inclined portion (17).

In accordance with the inclined portion (17), the distal end of the support pin (18) of the transfer device (13) is extended to the vicinity of the distal end of the reference pin (16), and the inclination of the reference pin (16) is increased. Inclined part (19) substantially parallel to part (17)
And

The support pin (18) of the transfer device (13) needs to be fitted into the hole from the opposite direction to the fixing block (6A).
Prior to delivery, the support pin (18) is pre-aligned so that the axis is aligned with the axis of the reference pin of the fixed block (6A).

Connecting rod (10) executed between transfer device (13) and fixed blocks (6A) (6B)
2 is the same as that of the conventional example shown in FIG. 2, but the upper end opening of the oil hole (5) in the piston pin hole (4) is closed by the reference pin (16) extension (21). Therefore, in the side tapering step of the small end portion (1), the intrusion of the cuttings (11) into the oil hole (5) is completely prevented, and the oil hole (5) is cleaned in a subsequent step. Can be eliminated, and damage of the diamond pin for processing the inner peripheral surface of the piston pin hole (4) due to the residual chips (11) in the oil hole (5) can be prevented. Moreover, the required insertion depth of the support pin (18) of the transfer device (13) is smaller than that of the inclined portions (17) and (1).
9), the connecting rod (10) can be reliably prevented from falling off from the support pin (18) during transport.

The present invention can also have the following configuration other than the first aspect.

The lower end of the reference pin extends to the opening end of the oil hole, the upper end of the reference pin is inclined toward the base end of the reference pin, and is opposite to the insertion side of the reference pin. The tip of the support pin of the transfer device inserted into the piston pin hole from (1) is formed with a slope substantially parallel to the slope of the tip of the reference pin, and is adjacent to the tip of the reference pin. Item 2. A reference pin for tapering a small end of a connecting rod according to Item 1.

[0018]

As described above, according to the present invention, since the open end of the oil hole in the piston pin is closed at the tip of the reference pin, chips generated by tapering the small end of the connecting rod enter the oil hole. Can be completely prevented, and the step of cleaning the oil hole for discharging chips can be eliminated. In addition, it is possible to prevent diamond chips used to machine the inner peripheral surface of the piston pin hole in the subsequent process from being damaged by cutting chips, thereby reducing the wear rate of diamond chips, preventing defective products due to broken chips, and furthermore, preventing the inner peripheral surface of the piston pin hole from being damaged. The inspection process of the quality of processing can be simplified.

[Brief description of the drawings]

FIG. 1A is a cross-sectional view of a connecting rod in a tapering step of a small end, and FIG. 1B is a cross-sectional view of a small connecting rod end when a connecting rod is delivered.

2A is a cross-sectional view of a connecting rod and a conventional fixing block, FIG. 2B is a front view of a connecting rod small end, and FIG. 2C is a fixing block provided with an extended reference pin and one of the connecting rod small ends. FIG. 4D is a sectional view of a small end portion of a connecting rod showing a conventional example of a fixed block and a transfer device.

[Explanation of symbols]

 DESCRIPTION OF SYMBOLS 1 Small end of connecting rod 5 Oil hole 6A Fixed block 6B Fixed block 10 Connecting rod 15 Side part of small end (tapered portion) 16 Reference pin 17 Inclined portion 18 Support pin 19 Inclined portion

──────────────────────────────────────────────────続 き Continued on the front page (58) Field surveyed (Int. Cl. ⁷ , DB name) F16B 19/02 B23Q 3/18 B23Q 11/00 F16C 7/02

Claims (1)

(57) [Claims] A connecting rod for connecting a piston pin hole at the small end and a crankpin hole at the large end at a connecting portion connecting the small end and the large end; In the tapering step on both side surfaces of the small end, from the fixed block to the piston pin hole with the small end facing upward.
In a positioning fixing block for fitting and positioning and fixing a protruding reference pin, a tip portion of the reference pin is extended to an opening end of an oil hole opened on an inner peripheral surface of the piston pin hole, and the extension portion A reference pin for tapering a small end of a connecting rod, wherein an opening end of the oil hole is closed.