CN114080282B

CN114080282B - Link breaking device, link breaking method, and link manufacturing method

Info

Publication number: CN114080282B
Application number: CN202080050118.9A
Authority: CN
Inventors: 松井淳悟; 长谷浩一; 村田岳人
Original assignee: Yasunaga Corp
Current assignee: Yasunaga Corp
Priority date: 2019-08-05
Filing date: 2020-07-29
Publication date: 2022-10-25
Anticipated expiration: 2040-07-29
Also published as: JP2021024030A; CN114080282A; WO2021024891A1; JP7340317B2

Abstract

In order to provide a device and a method for breaking a connecting rod, which can form a predetermined breaking surface with high yield when a large diameter portion of the connecting rod is broken in a two-part manner, the device is provided with clamps (510, 520), and is also provided with a clamp pressing position limiting mechanism (600), wherein the clamps (510, 520) are used for pressing bolt seat surfaces (921, 922) of the large diameter portion before breaking the large diameter portion (920) of the connecting rod (900) mounted on the breaking device, and are used for limiting the movement of the large diameter portion broken in a two-part manner to the direction vertical to a central axis direction when breaking, and the clamp pressing position limiting mechanism (600) is used for limiting the movement of the clamps in a manner that the position of the large diameter portion of the clamps stays at the position consistent with the nominal value of the machining tolerance of the connecting rod before breaking the large diameter portion in the state of the connecting rod mounted on the breaking device.

Description

Link breaking device, link breaking method, and link manufacturing method

Technical Field

The present invention relates to a connecting rod disconnecting apparatus and a connecting rod disconnecting method for disconnecting a large diameter portion of a connecting rod used in an internal combustion engine such as an engine of an automobile, and a connecting rod manufacturing method using the same.

Background

A link breaking device for breaking and dividing a large diameter portion is conventionally known (see, for example, patent documents 1 and 2).

The above patent document 1 relates to an invention relating to a link disconnecting and separating device, wherein a support member capable of moving forward is provided for holding a large end portion of a link, and the support member includes a wedge member having one end holding the large end portion of the link and the other end movable in a direction perpendicular to the support member.

Further, patent document 2 is an invention relating to a method and an apparatus for splitting a connecting rod, in which an external pressure is applied to a large end portion of the connecting rod in order to suppress an internal pressure applied when the large end portion of the connecting rod is split, and the external pressure is instantaneously released when the large end portion of the connecting rod becomes an internal pressure capable of splitting.

Further, patent document 1 is a mechanism in which the lever side is moved greatly by a reaction force at the time of disconnection, and patent document 2 applies pressure to the link immediately before disconnection to perform disconnection while suppressing deformation of the large end portion.

Documents of the prior art

Patent document

Patent document 1: japanese Kokai publication Hei-2001-512049

Patent document 2: japanese laid-open patent publication No. 10-277848

Disclosure of Invention

Problems to be solved by the invention

As a point that becomes a problem when the large diameter portion of the connecting rod is disconnected, a case where an excessive force is applied to the connecting rod by clamping with a hydraulic pressure is cited. Thus, if the connecting rod is broken in a state of strain (in a state of deformation), the large diameter portion is divided into two parts in a state where undesirable internal stress remains at the time of breaking, and an adverse effect is generated at the time of breaking division.

Specifically, problems may be that the fracture end position of the large diameter portion deviates from a standard desired state, or the fracture surface does not become an ideal fracture surface that matches the design value, and the yield is reduced. Therefore, there is a need for a link disconnecting apparatus having a structure capable of reducing an external force applied when holding a link and sufficiently withstanding a reaction force at the time of disconnection.

The contents of patent documents 1 and 2 do not have a structure for solving the above problems. More specifically, patent document 1 discloses the following: before the large diameter portion of the connecting rod is broken, the large end portion is firmly pressed by a combination of the hydraulic cylinder and the wedge member via 2 pins. Further, patent document 2 also discloses that the large diameter portion of the connecting rod is firmly pressed by a fluid pressure cylinder via an external pressure applying device before being broken.

Therefore, it is obvious that the problems of the present invention cannot be solved by the inventions described in these patent documents.

The present invention aims to provide a connecting rod breaking device, a connecting rod breaking method and a manufacturing method, wherein when a large-diameter part of a connecting rod is divided into two parts to be broken, a predetermined breaking surface can be formed with high yield.

Means for solving the problems

In order to solve the above-mentioned problems, the tie rod breaking device according to claim 1 is a tie rod breaking device in which a mandrel is engaged with a large diameter portion of a tie rod and a tie rod breaking wedge is driven into the mandrel along a central axis of the large diameter portion of the tie rod to divide the large diameter portion of the tie rod into two parts, the tie rod breaking device including a jig for pressing a bolt seat surface of the large diameter portion before breaking the large diameter portion of the tie rod attached to the breaking device and restricting movement of the large diameter portion divided into two parts in a direction perpendicular to the central axis direction of the large diameter portion when breaking, and the tie rod breaking device further including a jig pressing position restricting mechanism for restricting movement of the jig in a state where the tie rod is attached to the breaking device of the tie rod so that a position where the jig presses the large diameter portion before breaking the large diameter portion stays at a position that coincides with a nominal value of a machining tolerance of the tie rod.

Further, a method for disconnecting a link according to claim 2 is a method for manufacturing a link having a large diameter portion divided into two parts by driving a link-disconnecting wedge into a mandrel engaged with the large diameter portion of the link along a center axis of the large diameter portion of the link using a link-disconnecting device, wherein the link is attached to the link-disconnecting device, the mandrel is engaged with the large diameter portion of the link, and a jig provided in the link-disconnecting device is used to press a bolt seat surface of the large diameter portion of the link with a predetermined pressing force within a predetermined range before disconnecting the large diameter portion of the link, and at this time, in a state where the link is attached to the link-disconnecting device, movement of the jig is restricted by using a jig pressing position restricting mechanism provided in the link-disconnecting device, so that a position of the jig pressing the large diameter portion before disconnecting the large diameter portion is retained at a position corresponding to a nominal value of a machining tolerance of the link, and the link-disconnecting wedge is driven into the mandrel, thereby manufacturing a link having a large diameter portion divided into two parts.

The method for manufacturing a connecting rod according to claim 3 is characterized in that a connecting rod before being split is prepared, the connecting rod is attached to the splitting apparatus for a connecting rod according to claim 1, and the connecting rod having a large diameter portion split into two parts is manufactured by using the splitting apparatus for a connecting rod.

The method for manufacturing a connecting rod according to claim 4 is characterized in that a connecting rod before being split is prepared, and a connecting rod having a large diameter portion split into two parts is manufactured by the method for splitting a connecting rod according to claim 2.

Effects of the invention

According to the present invention, it is possible to provide a disconnecting device, a disconnecting method, and a manufacturing method for a connecting rod, which can form a predetermined disconnecting surface with high yield when the large diameter portion of the connecting rod is disconnected so as to be divided into two parts.

Drawings

Fig. 1 is a plan view showing a link disconnecting apparatus according to an embodiment of the present invention.

Fig. 2 is a side view showing a link disconnection apparatus according to an embodiment of the present invention.

Fig. 3 is a schematic diagram illustrating the principle of a link opening device and a link opening method according to an embodiment of the present invention. More specifically, fig. 3 (a) is a plan view showing a state in which the distal end surface of the bolt seat surface pressing portion of the jig is positioned at a position corresponding to the design nominal value of the bolt seat surfaces at two positions of the large diameter portion of the tie rod by the jig pressing position restricting stopper of the present invention. Fig. 3 (b) is a plan view corresponding to fig. 3 (a), and is an enlarged plan view of a portion of the bolt bearing surface of the link, the clip, and the clip pressing position restricting stopper. Fig. 3 (c) is an explanatory diagram illustrating a process until the stopper abutting portion of the jig is pressed by the stopper.

Fig. 4 is an explanatory view showing a relative positional relationship among the bolt seat surface of the large diameter portion of the tie rod, the bolt seat surface pressing portion of the jig, and the jig pressing position restricting stopper of the present invention corresponding to various forms of the machining tolerance of the tie rod.

Detailed Description

A link opening device and a link opening method according to an embodiment of the present invention (hereinafter, appropriately referred to as "the present embodiment") will be described below with reference to the drawings. First, a link broken by the present invention will be explained.

The connecting rod is a mechanical element for connecting a crankshaft and a piston head of an engine, and is a mechanical element in which a bearing (hereinafter, referred to as a "large diameter bearing") that is an opening portion of a large diameter portion axially supports a journal of the crankshaft and a bearing (hereinafter, referred to as a "small diameter bearing") of a small diameter portion axially supports a piston pin. The piston pin is axially supported by inserting a small diameter bearing therethrough, and both ends are supported by the bearing shaft of the piston head.

On the other hand, the large diameter bearing is divided into a rod portion and a cap portion at a predetermined diameter position, and the rod portion and the cap portion are fixed by bolts after the journal of the crankshaft is surrounded, thereby pivotally supporting the journal.

Next, a disconnecting device and a disconnecting method of the present embodiment for disconnecting the link will be described. Fig. 1 is a plan view showing a link disconnecting apparatus according to an embodiment of the present invention. Fig. 2 is a side view showing a link disconnecting apparatus according to an embodiment of the present invention.

Fig. 3 is a schematic diagram illustrating the principle of a link breaker and a link breaking method according to an embodiment of the present invention. More specifically, fig. 3 (a) is a plan view showing a state in which the distal end surface of the bolt seat face pressing portion of the jig is positioned at a position corresponding to the design nominal value of the bolt seat faces at two positions of the large diameter portion of the tie rod by the jig pressing position restricting stopper of the present invention. Fig. 3 (b) is a plan view corresponding to fig. 3 (a), and is an enlarged plan view of a portion of the bolt bearing surface of the connecting rod, the jig, and the jig pressing position restricting stopper. Fig. 3 (c) is an explanatory diagram showing a process up to the stopper abutting portion of the stopper pressing jig.

Fig. 4 is an explanatory diagram for easily understanding a relative positional relationship among the bolt seat surface of the large diameter portion of the tie rod, the bolt seat surface pressing portion of the jig, and the jig pressing position restricting stopper according to the present invention, which correspond to various forms of machining tolerances of the tie rod.

The link opening device 1 of the present embodiment includes: a base frame 40; a base 50 provided on the base frame; support plates (support members) 110 and 120 (100) slidably provided on the base so as to be close to or separated from each other within a predetermined range; and a disconnecting mechanism 200 attached to the base frame 40, and having a link 900 to be disconnected placed on the support plate 100 via the support plates 110 and 120 (100).

The base 50 functions to indirectly support the link 900, and horizontally places and supports the link 900 via the support plate 100. The 2 support plates 100 (first support plate 110 and second support plate 120) are disposed on the base so as to face each other with a slight gap therebetween.

The disconnecting mechanism 200 is firmly attached to the base frame 40, and functions to disconnect the link 900 horizontally supported by the support plates 110 and 120 (100).

The 2 support plates 110 and 120 (100) are provided with hydraulic cylinders, not shown, respectively, and the 2 support plates 110 and 120 (100) can be moved on the base in directions to approach or separate from each other. That is, by driving a hydraulic cylinder (not shown), the

spindle halves

131 and 132 fixed to the 2 support plates 110 and 120 (100) are separated from each other, and the

spindle halves

131 and 132 can be pressed against the open inner circumferential surface of the large diameter portion 920 of the connecting rod 900.

Next, the structure of the mandrel 130 will be described. As shown in fig. 1 and 2, the spindle 130 is composed of a pair of half-split spindles fixed to the upper surfaces of the support plates 110 and 120 (100) via bolts.

A base 150 on which the small diameter portion 910 of the connecting rod 900 is horizontally placed is provided on the rear end upper surface of the support plate 110. The positioning pin 151 is provided upright from the mount 150, and the positioning pin 151 is fitted into an opening of the small diameter portion 910 of the connecting rod 900 to restrain the small diameter portion 910 of the connecting rod 900.

Next, the opening mechanism 200 of the link 900 will be described. The disconnecting mechanism 200 of the link 900 is attached to the base frame 40. In addition, a hydraulic cylinder 260 is vertically mounted on the base frame 40. Further, a large-diameter-portion breaking wedge 250 is attached to the hydraulic cylinder 260 via a rod 261.

The large-diameter portion breaking wedge 250 is vertically driven between the 2

mandrel halves

131, 132 at the time of the tie rod breaking. As described above, the large-diameter portion breaking wedge 250 has 2 tapered portions formed symmetrically in the axial direction so as to match the tapered surfaces formed in the spindle halves 131 and 132. The large-diameter portion disconnecting wedge 250 is raised and lowered by the hydraulic cylinder 260, and the spindle halves 131 and 132 are moved equally in directions away from each other when lowered.

The support plate 110 is provided with hydraulic lever-type pressing portions 171 and 172 (170) that press both small-diameter-side shoulders 923 and 924 (see fig. 1) of the large-diameter portion 920 of the link 900, respectively, and presses both small-diameter-

side shoulders

923 and 924 of the large-diameter portion 920 toward the spindle 130 when the link is disconnected.

The clamps 510, 520 (500) function as follows: before the large diameter portion 920 of the connecting rod 900 is broken, the bolt seat surfaces 921, 922 of the large diameter portion 920 are pressed, and the large diameter portion 920 divided into two parts is restricted from moving in a direction perpendicular to the central axis direction thereof at the time of breaking.

The jigs 510 and 520 (500) have a pair of structures of the same shape that press the bolt seat surfaces 921 and 922 of the large diameter portion 920 of the link 900, respectively. Therefore, in the following description, a reference numeral without a bracket is given to one jig, and a reference numeral with a bracket is given to the other jig. In fig. 2, only no parenthesized reference numerals are denoted, and in fig. 1, 3, and 4, both no parenthesized reference numerals and parenthesized reference numerals are denoted.

The jig 510 (520) has: a jig main body 511 (521) having a large-diameter axial shape; a bolt seat surface pressing portion 512 (522) extending from the distal end portion of the jig main body 511 (521) and having a smaller diameter than the jig main body 511 (521); a cylinder connection portion 514 (524) extending from the base end side of the jig main body 511 (521); and a hydraulic cylinder 550 that moves the jig body 511 (521) and the bolt seat face pressing portion 512 (522) via the cylinder coupling portion 514 (524) relative to the bolt seat face 921 (922) of the large diameter portion 920 of the link 900, thereby pressing the bolt seat face pressing portion 512 (522) against the bolt seat face 921 (922) or separating the bolt seat face pressing portion 512 (522) from the bolt seat face 921 (922). The hydraulic cylinder 550 is firmly fixed to the support plate 120 via a fixing member 551. Further, a step portion formed at a connecting portion of the jig main body 511 (521) and the bolt seat surface pressing portion 512 (522) becomes a stopper abutting portion 513 (523) described later.

As shown in fig. 1, cylinder coupling portion 514 (524) is coupled to cylinder 550 via coupling plate 552, whereby the operating force of cylinder 550 is transmitted to both clamps 510 (520) at the same time, and both clamps 510 (520) are operated in synchronization with each other.

The hydraulic cylinder 550 and the jig main body 511 (521) are attached to one support plate 120. Further, a spring is clamped to a small diameter portion of each connecting portion connecting the jig main body 511 (521) and the hydraulic cylinder 550.

In the vicinity of the stopper contact portion 513 (523) of each jig, a jig pressing position regulation mechanism 600, which is an important constituent element in the present invention, is provided. The jig pressing position defining mechanism 600 functions as follows: in a state where the link 900 is attached to the link disconnecting apparatus 1, the movement of the jig 510 (520) is restricted so that the bolt seat surface pressing portion 512 (522) does not move excessively (over-press) beyond a position that coincides with a nominal value of a machining tolerance of the link 900 (see fig. 3 (b) and a broken line N in fig. 4) before the large diameter portion 920 is disconnected. The nominal value of the machining tolerance referred to herein is a design reference value (indicated value), and does not mean a central value (average value) of the machining tolerance region.

The jig pressing position limiting mechanism 600 includes: a stopper 610 (620); a stopper slide guide 630 (640) that firmly supports the stopper 610 (620) in a state of being capable of sliding movement; and a stopper working actuator 650 (660) that slidingly moves the stopper 610 (620).

The stopper 610 (620) is formed of, for example, a rectangular metal plate material having a sufficient thickness and excellent strength and durability, and has a cut-out portion 611 (621) formed at the tip thereof so as to fit into the step portion of the stopper contact portion 513 (523) (see fig. 3 (c)), and the periphery of the cut-out portion 611 (621) abuts against the step portion of the stopper contact portion 513 (523), thereby restricting further movement of the jig 510 (520) toward the large diameter portion 920 of the link 900 when the stopper is operated.

That is, as shown in fig. 4 a, when the connecting rod is machined to match the nominal value of the machining tolerance (see the broken line N in fig. 4 a), and as shown in fig. 4 c, when the connecting rod is machined to be slightly more negative than the nominal value N of the machining tolerance (see the broken line N-y in fig. 4 c), the small-diameter bolt seat surface pressing portion 522 (512) of the jig 520 (510) passes through the cutout portion 621 (611), the tip end of the large-diameter jig body 521 (511) abuts against the jig body side surface of the stopper 620 (610) in which the cutout portion 621 (611) is formed, and as a result, the jig 520 (510) does not move further with respect to the bolt seat surface 922 (921) of the large-diameter portion 920.

The stopper slide guide 640 (630) has a structure in which the stopper 620 (610) can be slidably moved in a direction perpendicular to the moving direction of each jig 520 (510) while firmly supporting the stopper 620 (610).

Further, the holding force of the stopper slide guide 640 (630) against the stopper 620 (610) in the direction perpendicular to the moving direction of each of the clamps 520 (510) becomes a holding force capable of sufficiently receiving a force equivalent to the full pressing force of the hydraulic actuator for clamp working used in the conventional link opening device which does not have the clamp pressing position restricting mechanism 600 of the present invention against the clamps.

Accordingly, in the disconnecting device 1 to which the link according to the present invention is applied, the hydraulic actuator for operating the jig, which is conventionally used, can be directly used, and the effort for designing the hydraulic actuator in particular can be omitted.

Further, by unitizing the jig pressing position restricting mechanism 600, even in the conventional link disconnecting device, it is possible to attach the device as long as the installation space of the unit can be secured. With this, the problem described in the problem section to be solved by the present invention can be solved at a glance even in the conventional link disconnecting device.

Although not specifically described in the present embodiment, the stopper work actuator 660 (650) is used to slidably move the stopper 620 (610) along the stopper slide guide 640 (630) by a predetermined stroke. Further, a hydraulic cylinder is generally considered as a specific configuration, but the present invention is not limited to this, and various types such as a pneumatic cylinder, a combination of a motor and a reduction machine, and a rack and pinion pair can be adopted.

The positions at both ends of the movement stroke of the stopper 620 (610) that is moved along the stopper slide guide 640 (630) by the stopper work actuator 660 (650) stand by at a non-operating position (see the two-dot chain line of (c) in fig. 3) where the stopper 620 (610) does not obstruct the movement of the jig 520 (510) by the hydraulic cylinder 550 in a state where the jig pressing position limiting mechanism 600 is not operated, and reach an operating position (see the solid line of (c) in fig. 3) when the jig pressing position limiting mechanism 600 is operated, and the operating position is a position where the tip end of the stopper 620 (610) and the vicinity thereof come into contact with the stopper contact portion 523 (513) of the jig 520 (510) when the bolt seat surface pressing portion 522 (512) of the jig 520 (510) comes to the bolt seat surface 922 (921) of the link 900 later.

Further, in a state where the tip end portion of the stopper 620 (610) and the vicinity thereof stay at the position in contact with the stopper contact portion 523 (513) of the jig 520 (510), when the large diameter portion 920 of the link 900 is disconnected, the impact force at the time of disconnection transmitted via the bolt seat surface 922 (921) of the large diameter portion 920 is absorbed by the hydraulic cylinder 550 only via the jig 520 (510). That is, the impact force at the time of disconnection is not transmitted to the stopper 620 (610).

While such a state after the disconnection is ensured, the stopper 620 (610) contacts the stopper contact portion 523 (513) of the jig 520 (510) before the disconnection of the large diameter portion 920, thereby restricting the movement of the jig 520 (510) in the direction toward the bolt seat surface 922 (921) of the large diameter portion 920.

Next, a description will be given of a link 900 breaking step of the link 900 using the link breaking device 1 of the present embodiment, that is, a method of manufacturing the broken link 900.

First, the pre-disconnection link 900 is prepared. Then, the link 900 is mounted on the support plates 110 and 120 (100) on the base. Thereby, the spindle 130 is inserted into the large diameter portion 920 of the connecting rod 900 to support the large diameter portion 920.

In this way, the link 900 is attached to the link disconnecting device 1, and the spindle 130 is engaged with the large diameter portion 920 of the link 900.

Then, the jig pressing position restricting mechanism 600 constituting an essential part of the present invention is operated. Specifically, the stopper 610 (620) is moved by the stopper work actuator 650 (660) in a direction to approach the jig 510 (520) along the stopper slide guide 630 (640). Then, the stopper 610 (620) is slid by a predetermined travel stroke of the stopper 610 (620), and after reaching a position for restricting the movement of the jig 510 (520), the sliding movement of the stopper 610 (620) is stopped (see the arrows from the broken line to the solid line in fig. 3 (a), (b), and 3 (c)).

Next, the jig 510 (520) is moved toward the large diameter portion of the link by the driving force of the hydraulic cylinder. In the process of moving the jig 510 (520) toward the bolt seat face 921 (922) of the large diameter portion 920, the stopper abutting portion 513 (523) formed at the coupling portion of the large diameter jig main body 511 (521) and the bolt seat face pressing portion 512 (522) having a smaller diameter abuts on the tip of the stopper 610 (620) to prevent further movement of the jig 510 (520), so that the jig 510 (520) does not further move toward the bolt seat face 921 (922) of the large diameter portion 920.

In this way, before the large diameter portion 920 of the link 900 is disconnected, the jig 510 (520) provided in the link disconnecting apparatus 1 is used to suppress the displacement of the bolt seat surface 921 (922) of the large diameter portion 920 of the link 900 when the large diameter portion of the link is disconnected.

At this time, as shown in fig. 4 b, when the connecting rod 900 is machined to be on the positive side of the nominal value of the machining tolerance (see the broken line N of fig. 4 b) within the range of the machining tolerance (see the broken line N + x of fig. 4 b), when the bolt seat surface 922 (921) of the large diameter portion 920 of the connecting rod 900 is pressed by the jig 520 (510) via the front end surface 522a (512 a) of the bolt seat surface pressing portion 522 (512), the large diameter portion 920 of the connecting rod 900 displaced to the jig side by a slight amount (specifically, several tens of micrometers) by which the pressing force is deviated from the designed nominal value of the large diameter portion 920 of the connecting rod 900, which is defined to be positive within the range of the machining tolerance, is not completely pressed (100% of the pressing force is not applied) by the hydraulic pressure of the hydraulic cylinder 550.

Thus, the large diameter portion 920 of the connecting rod 900, which has been machined with an offset amount that is offset from the nominal value by the allowable amount and is defined on the positive side of the machining tolerance, can be pressed only by the bolt seat surface pressing portion 522 (512) of the jig 520 (510). As a result, in this state, the bolt seat surface 922 (921) is pressed by the jig 520 (510) without exceeding the upper limit value of the predetermined pressing force.

That is, since the stopper 620 (610) restricts the forward position of the jig 520 (510) so that the movement of the jig 520 (510) is stopped at the position corresponding to the nominal value, the bolt seat surface 922 (921) of the large diameter portion 920 is not completely pressed with an undesirably large force by the hydraulic cylinder and the jig as in the conventional case.

As shown in fig. 4 a, when the attached link 900 matches the nominal value of the machining tolerance (see the broken line N in fig. 4 a), the bolt bearing surface pressing portion 522 (512) of the jig 520 (510) is brought into a state in which the tip end surface 522a (512 a) thereof is in contact with only the bolt bearing surface 922 (921) of the large diameter portion 920 by the action of the stopper, and an undesirable pressing force is not applied to the bolt bearing surface 922 (921) via the bolt bearing surface pressing portion 522 (512) of the jig 520 (510) before the large diameter portion 920 of the link 900 is disconnected.

On the other hand, as shown in fig. 4 c, when the tie rod 900 is machined to the negative side of the nominal value of the machining tolerance (see the broken line N in fig. 4 c) within the range of the machining tolerance (see the broken line N-y in fig. 4 c), when the bolt seating surface 922 (921) of the large diameter portion 920 of the tie rod 900 is pressed by the jig 520 (510), a gap of about several tens of micrometers is generated between each bolt seating surface 922 (921) of the large diameter portion 920 and the tip end surface 522a (512 a) of the bolt seating surface pressing portion 522 (512) of the jig 520 (510). In this case as well, as in the case where the attached connecting rod 900 matches the nominal value of the machining tolerance, an undesired pressing force is not applied to the bolt seat surface 922 (921) via the bolt seat surface pressing portion 522 (512) of the jig 520 (510) before the large diameter portion 920 of the connecting rod 900 is broken.

In the case shown in fig. 4 (c), even if an impact force is instantaneously applied to the large diameter portion 920 after the bolt seat surface side is broken when the large diameter portion 920 is broken, a gap of about several tens of micrometers is generated between the bolt seat surface 922 (921) and the front end surface 522a (512 a) of the bolt seat surface pressing portion 522 (512) of the jig 520 (510) from before the breaking, so that the bolt seat surface 922 (921) of the large diameter portion 920 after the breaking can be held by the jig 520 (510) without causing a slight movement to the bolt seat surface side of the large diameter portion after the breaking.

As a result, the bolt seat surface side of the large diameter portion 920 after the disconnection does not undesirably shift along the periphery of the spindle half in contact therewith, for example, and the disconnection surfaces do not collide with each other and are not damaged by such a shift.

While sharing the advantages peculiar to the present invention, the large diameter portion breaking wedge 250 is driven into the mandrel 130 to divide the large diameter portion 920 of the connecting rod 900 into two parts. At the time of this disconnection, as described above, the stopper 620 (610) of the jig pressing position restricting mechanism 600 is not subjected to the impact force at the time of disconnection of the large diameter portion 920 of the link 900.

That is, the impact force is transmitted only to the hydraulic cylinder 550 that operates the clamp 520 (510), and the entire impact force is absorbed by the hydraulic cylinder 550. Therefore, the clip pressing position regulating mechanism 600 is not adversely affected by the impact force at the time of disconnection.

After the impact force is absorbed by the hydraulic cylinder 550 in this manner, the stopper 610 (620) is retreated (moved in the direction opposite to the arrow in fig. 3 (c)) along the stopper slide guide 630 (640), and the jig pressing position regulating mechanism 600 is set to the non-operating state. Thereafter, the broken link is taken out and carried out in a usual procedure.

The connecting rod 900 before the disconnection is prepared in this way, and the connecting rod 900 in which the large diameter portion 920 is divided into two parts is manufactured by the method of disconnecting a connecting rod according to the present invention, whereby the following operational effects can be exhibited.

Specifically, according to the present invention, the bolt bearing surface of the large diameter portion of the connecting rod is pressed without exceeding a predetermined pressing force within a predetermined range by using the jig provided in the disconnecting device for the connecting rod.

Accordingly, all the problems described in the problem section to be solved by the present invention can be solved. Specifically, such a situation can be avoided: by clamping the jig in a so-called fully-pressed state by the pressure of the hydraulic cylinder, an excessive force is applied to the link, whereby the link is broken in a strained state (in a deformed state). As a result, the large diameter portion is not divided into two parts in a state where an undesirable internal stress remains at the time of disconnection, and adverse effects at the time of disconnection due to pressing of the bolt seat surface of the large diameter portion by the jig before disconnection are prevented.

Thus, the fracture end position of the large diameter portion is not deviated from the standard desired state, and the fracture surface does not become an ideal fracture surface that matches the design value. More specifically, for example, a defect that the interruption end position of the large diameter portion cannot be formed in accordance with design specifications so as to correspond to the interruption start position of the large diameter portion is prevented, or a disconnection surface that does not become an ideal disconnection surface in accordance with design values and becomes a 3-dimensional undulation is prevented. This can avoid the problem of a reduction in yield, and can form a predetermined fracture surface with good yield when the large diameter portion of the connecting rod is fractured so as to be divided into two.

Further, by unitizing the jig pressing position restricting mechanism, even in the conventional link disconnecting device, it is possible to perform attachment as long as the installation space of the unit can be secured. With this, the problem described in the problem section to be solved by the present invention can be solved at a glance even in the conventional link disconnecting device.

Needless to say, the scope of the present invention is not limited to the contents of the above-described embodiments. That is, even if the present invention has a different form from the above-described embodiment, it is needless to say that the present invention is included in the scope of the present invention as long as the present invention has an creative configuration that conforms to the technical idea defined in the present invention and exerts the effect thereof.

Specifically, in the above-described embodiment, for example, the link disconnecting device may be configured to have a configuration in which the hydraulic cylinder is positioned above the link. The disconnecting device may be a link having a configuration in which the upper side of the link is pressed by pressing the support plate with the upper surface of the link. The link may be a disconnecting device in which a base plate is provided on the outer periphery of the turntable.

In addition, the present invention can of course be applied to all the following technical fields: in a case in which a member having a shaft-like or cylindrical outer shape such as a crankshaft or a bearing is sandwiched and held or fixed, a breaking slit is formed in an appropriate portion of the case, a spindle is inserted into a circular housing portion for the bearing or the crankshaft as viewed from an end surface, and the spindle is driven to break the case into 2 pieces.

As described above, the present invention has been made in view of the above-mentioned facts that, in order to firmly press the bolt seating surface after the large diameter portion of the connecting rod is broken, the large diameter portion before the breaking is pressed by the so-called full pressing by the hydraulic mechanism via the jig before the breaking, which causes an excessive internal stress to be generated in the large diameter portion before the breaking, which becomes a factor of hindering the formation of a beautiful broken surface as a design rule or the formation of a breaking end position as a rule at the time of the breaking, and it is a great technical significance to solve the problem by using a special pressing position mechanism for the jig based on the finding.

More specifically, the present inventors have found that, in order to prevent a phenomenon that may occur in a special machining mode that is dynamically performed at an extremely short moment and that involves a break due to a combination of a wedge of a large diameter portion of a connecting rod and a mandrel, for example, when a half portion of the large diameter portion of the broken connecting rod that is separated from the small diameter portion is displaced along a half portion of the mandrel with which the inner peripheral surface is in contact due to an instantaneous break force and the break surfaces of the half portions after the break on the opposite side are brought into contact with each other to damage the break surfaces, two bolt seat surfaces of the large diameter portion are firmly pressed by a full pressing force of a hydraulic cylinder via a jig, but countermeasures for preventing the problem after the break rather have a potential adverse effect on the large diameter portion of the connecting rod before the break, and based on this finding, it can be said that taking the countermeasures as in the present invention have a very great technical significance.

Description of the reference symbols

1: a disconnecting device of the connecting rod; 40: a base frame; 50: a base; 110. 120 (100): a support plate (support member); 130: a mandrel; 131. 132: a mandrel half; 150: a pedestal; 151: positioning pins; 171. 172 (170): a rod-shaped pressing portion; 200: a disconnection mechanism section; 250: a wedge for breaking the large diameter part; 260: a hydraulic cylinder; 261: a rod; 510. 520 (500): a clamp; 511. 521: a clamp body; 512. 522: a bolt seat surface pressing part; 512a, 522a: a front end face; 513. 523: a stopper abutting portion; 514. 524: a hydraulic cylinder connecting part; 550: a hydraulic cylinder; 551: a fixing member; 552: a connecting plate; 600: a jig pressing position limiting mechanism; 610 (620): a stopper; 611 (621): a cut-out portion; 630 (640): a stopper slide guide; 650 (660): an actuator for stopping work; 900: a connecting rod; 910: a small diameter part; 920: a large diameter portion; 921. 922: a bolt seat face; 923. 924: the small diameter portion side shoulders.

Claims

1. A connecting rod disconnecting device for dividing a large diameter portion of a connecting rod into two parts by engaging a mandrel with the large diameter portion of the connecting rod and driving a connecting rod disconnecting wedge into the mandrel along a central axis of the large diameter portion of the connecting rod,

the link breaking device includes a jig for pressing a bolt seat surface of a large diameter portion of a link attached to the breaking device before the large diameter portion is broken, and for restricting the large diameter portion, which is broken in two parts, from moving in a direction perpendicular to a central axis direction of the large diameter portion when the link is broken,

the link breaking device further includes a jig pressing position restricting mechanism that restricts movement of the jig in a state where the link is attached to the link breaking device such that a position of the jig pressing the large diameter portion before the large diameter portion is broken remains at a position that matches a nominal value of a machining tolerance of the link.

2. A method of disconnecting a connecting rod, in which a connecting rod disconnecting wedge is driven into a mandrel engaged with a large diameter portion of the connecting rod along a central axis of the large diameter portion of the connecting rod, using a connecting rod disconnecting device, thereby manufacturing a connecting rod having a large diameter portion divided into two parts,

a disconnecting device for attaching the link to the link and engaging the spindle with the large diameter portion of the link,

before the large diameter portion of the connecting rod is broken, the bolt bearing surface of the large diameter portion of the connecting rod is pressed by a predetermined pressing force within a predetermined range using a jig provided in a breaking device of the connecting rod, and at this time, in a state where the connecting rod is attached to the breaking device of the connecting rod, the movement of the jig is restricted using a jig pressing position restricting mechanism provided in the breaking device of the connecting rod so that the position of the jig pressing the large diameter portion before the large diameter portion is broken stays at a position that coincides with a nominal value of a machining tolerance of the connecting rod, and a connecting rod breaking wedge is driven into the mandrel, thereby manufacturing the connecting rod in which the large diameter portion is divided into two parts.

3. A method for manufacturing a connecting rod is characterized in that,

the connecting rod before the disconnection is prepared,

a disconnecting device for mounting the link to the link according to claim 1,

a connecting rod having a large diameter portion divided into two parts is manufactured by a breaking device using the connecting rod.

4. A method for manufacturing a connecting rod is characterized in that,

the connecting rod before the disconnection is prepared,

a connecting rod having a large diameter portion divided into two parts is manufactured by the connecting rod splitting method according to claim 2.