JP7340317B2 - Connecting rod breaking device, breaking method, and connecting rod manufacturing method - Google Patents

Description

The present invention relates to a connecting rod breaking device and method for breaking a large diameter portion of a connecting rod used in an internal combustion engine such as an automobile engine, and a method for manufacturing a connecting rod using these devices and methods.

A connecting rod breaking device used to break and divide a large diameter portion is conventionally known (see, for example, Patent Document 1 and Patent Document 2).

Patent Document 1 is an invention related to a connecting rod breaking and splitting device, in which a support member that can move forward is provided to hold the large end of the connecting rod, one end of the support member holds the large end of the connecting rod, The other end includes a wedge member movable in a direction perpendicular to the support member.

Further, Patent Document 2 is an invention related to a method and device for breaking and splitting a connecting rod, and in order to suppress the internal pressure applied when breaking and splitting the large end of the connecting rod, external pressure is applied to the large end of the connecting rod. The external pressure is momentarily released when the internal pressure reaches such a level that the large end of the connecting rod can break and split.

The above-mentioned Patent Document 1 is a mechanism in which the rod side moves greatly due to the reaction force at the time of breakage, and the above-mentioned Patent Document 2 is a mechanism in which pressure is applied to the connecting rod until immediately before the connecting rod breaks, while suppressing deformation of the large end. It is broken and divided.

Special Publication No. 2001-512049 Japanese Patent Application Publication No. 10-277848

A problem with breaking the large diameter portion of the connecting rod is that extra force is applied to the connecting rod by hydraulic clamping. As a result, if the connecting rod is broken while it is still distorted (deformed), the large diameter portion will break into two pieces with undesirable internal stress remaining. , causing an adverse effect at the time of breaking and splitting.

Specifically, the end position of the fracture in the large diameter portion may deviate from the normal and preferred state, or the fracture surface may not be the ideal fracture surface that matches the design value, resulting in a decrease in yield. This is raised as a problem. Therefore, there is a need for a connecting rod breaking device that has a configuration that can reduce the external force applied when holding the connecting rod and can also sufficiently receive the reaction force at the time of breaking.

Note that the contents of Patent Documents 1 and 2 mentioned above do not have a structure for solving the above problem. More specifically, in Patent Document 1, before the large diameter portion of the connecting rod is broken, the large end portion is firmly pressed by a combination of a hydraulic cylinder and a wedge member via two pins. is disclosed. Patent Document 2 also discloses that before breaking the large diameter portion of the connecting rod, it is firmly pressed by a fluid pressure cylinder via an external pressure applying device.

Therefore, it is clear that the inventions described in these patent documents cannot solve the problems of the present invention.

An object of the present invention is to provide a connecting rod breaking device, a breaking method, and a manufacturing method that can form a prescribed broken surface with a high yield when breaking a large diameter portion of a connecting rod into two parts.

In order to solve the above-mentioned problems, a connecting rod breaking device according to claim 1 of the present invention includes:
A connecting rod that engages a mandrel with a large diameter portion of the connecting rod and drives a connecting rod breaking wedge into the mandrel along the central axis of the large diameter portion of the connecting rod to divide the large diameter portion of the connecting rod into two. In the breaking device of
Before breaking the large diameter part of the connecting rod attached to the breaking device, hold down the bolt seating surface of the large diameter part, and press the large diameter part that is to be broken into two parts at the time of breaking into the large diameter part. In addition to being equipped with a clamper to restrict movement in a direction perpendicular to the central axis direction of the
With the connecting rod attached to the connecting rod breaking device, the position of the clamper holding the large diameter portion remains at a position that matches a nominal value of the processing tolerance of the connecting rod before the large diameter portion is broken. A connecting rod breaking device equipped with a clamper holding position regulating mechanism for regulating the movement of the clamper,
The clamper is configured to move toward the bolt seating surface by the driving force of a hydraulic cylinder, and a stopper provided in the clamper holding position defining mechanism is arranged to move toward the large diameter portion of the connecting rod attached to the breaking device. By regulating the forward position of the clamper to stay at a position corresponding to the nominal value before breaking the clamper, the forward position of the clamper due to the driving force of the hydraulic cylinder does not exceed the position corresponding to the nominal value. The clamper is characterized in that the forward movement of the clamper is prevented by the stopper .

Furthermore, the method for breaking a connecting rod according to claim 2 of the present invention is as follows:
Using a connecting rod breaking device, drive a connecting rod breaking wedge into the mandrel engaged with the large diameter portion of the connecting rod along the central axis of the large diameter portion of the connecting rod, thereby splitting the large diameter portion into two. In the connecting rod breaking method for manufacturing connecting rods,
attaching the connecting rod to the connecting rod breaking device, and engaging the mandrel with the large diameter portion of the connecting rod;
Before breaking the large diameter portion of the connecting rod, use a clamper provided in the connecting rod breaking device to press the bolt seating surface of the large diameter portion of the connecting rod with a pressing force within a predetermined range. , With the connecting rod attached to the connecting rod breaking device, the nominal machining tolerance of the connecting rod is determined before breaking the large diameter portion using a clamper holding position defining mechanism provided in the connecting rod breaking device. A connecting rod whose large diameter portion is divided into two by driving a wedge for breaking the connecting rod into the mandrel while regulating the movement of the clamper so that the position of the clamper holding the large diameter portion remains at a position that matches the value. A method for breaking a connecting rod for manufacturing ,
The clamper is configured to move toward the bolt seating surface by the driving force of a hydraulic cylinder, and a stopper provided in the clamper holding position defining mechanism is arranged to move toward the large diameter portion of the connecting rod attached to the breaking device. By regulating the forward position of the clamper to stay at a position corresponding to the nominal value before breaking the clamper, the forward position of the clamper due to the driving force of the hydraulic cylinder does not exceed the position corresponding to the nominal value. The clamper is characterized in that the forward movement of the clamper is prevented by the stopper .

Further, the method for manufacturing a connecting rod according to claim 3 of the present invention includes:
Prepare the connecting rod before breaking,
Attaching the connecting rod to the connecting rod breaking device according to claim 1,
The present invention is characterized in that a connecting rod having a large diameter portion divided into two parts is manufactured by using the connecting rod breaking device.

Further, the method for manufacturing a connecting rod according to claim 4 of the present invention includes:
Prepare the connecting rod before breaking,
The present invention is characterized in that a connecting rod having a large diameter portion divided into two is manufactured by the method for breaking a connecting rod according to the second aspect.

According to the present invention, it is possible to provide a connecting rod breaking device, a breaking method, and a manufacturing method that can form a prescribed broken surface with a high yield when breaking a large diameter portion of a connecting rod into two parts.

FIG. 1 is a plan view showing a connecting rod breaking device according to an embodiment of the present invention. FIG. 1 is a side view showing a connecting rod breaking device according to an embodiment of the present invention. 1 is a schematic diagram illustrating the principle of a connecting rod breaking device and a breaking method according to an embodiment of the present invention. More specifically, FIG. 3(a) shows that the bolt seat of the clamper is placed at the position corresponding to the designed nominal value of the two bolt seating surfaces of the large diameter portion of the connecting rod by the clamper holding position regulating stopper according to the present invention. It is a top view which shows the state which positioned the front-end|tip surface of a surface holding part. Further, FIG. 3(b) is a plan view corresponding to FIG. 3(a), and is an enlarged plan view showing the bolt seating surface of the connecting rod, the clamper, and the clamper holding position defining stopper. Further, FIG. 3(c) is an explanatory diagram showing the process of pressing the stopper abutting portion of the clamper with the stopper. An explanatory diagram that clearly shows the relative positional relationship between the bolt seating surface of the large diameter part of the connecting rod of the present invention, the bolt seating surface pressing part of the clamper, and the clamper pressing position regulating stopper, which corresponds to various types of processing tolerances of the connecting rod. It is.

EMBODIMENT OF THE INVENTION Hereinafter, a connecting rod breaking device and a breaking method according to an embodiment of the present invention (hereinafter referred to as "the present embodiment" as appropriate) will be described based on the drawings. First, the connecting rod to be broken according to the present invention will be explained.

A connecting rod is a mechanical element that connects the engine crankshaft and piston head.The bearing (hereinafter referred to as the "large diameter bearing"), which is an opening in the large diameter part, pivotally supports the journal of the crankshaft, and the small diameter part A bearing (hereinafter referred to as a "small diameter bearing") is a mechanical element that pivotally supports the piston pin. The piston pin is inserted through a small-diameter bearing and is supported, and both ends are supported by bearings of the piston head.

On the other hand, large-diameter bearings are divided into two parts, a rod part and a cap part, at a predetermined diameter position, and after surrounding the journal of the crankshaft, the rod part and the cap part are fixed with bolts to pivotally support the journal. It has become.

Next, a breaking device and a breaking method according to this embodiment for breaking this connecting rod will be explained. FIG. 1 is a plan view showing a connecting rod breaking device according to an embodiment of the present invention. Further, FIG. 2 is a side view showing a connecting rod breaking device according to an embodiment of the present invention.

Moreover, FIG. 3 is a schematic diagram illustrating the principle of a connecting rod breaking device and a breaking method according to an embodiment of the present invention. More specifically, FIG. 3(a) shows that the bolt seat of the clamper is placed at the position corresponding to the designed nominal value of the two bolt seating surfaces of the large diameter portion of the connecting rod by the clamper holding position regulating stopper according to the present invention. It is a top view which shows the state which positioned the front-end|tip surface of a surface holding part. Further, FIG. 3(b) is a plan view corresponding to FIG. 3(a), and is an enlarged plan view showing the bolt seating surface of the connecting rod, the clamper, and the clamper holding position defining stopper. Further, FIG. 3(c) is an explanatory diagram showing the process of pressing the stopper abutting portion of the clamper with the stopper.

Further, FIG. 4 shows the relative positions of the bolt seating surface of the large diameter portion of the connecting rod of the present invention, the bolt seating surface pressing portion of the clamper, and the clamper pressing position defining stopper, corresponding to various types of processing tolerances of the connecting rod. It is an explanatory diagram showing a relationship in an easy-to-understand manner.

The connecting rod breaking device 1 according to the present embodiment includes a base frame 40, a base 50 provided on the base frame, and support plates (support plates) slidably installed on the base so as to approach or separate from each other within a predetermined range. A connecting rod 900 to be broken is provided on the support plate 100 via the support plates 110 and 120 (100). is now placed.

The base 50 serves to indirectly support the connecting rod 900, and supports the connecting rod 900 by placing it horizontally through the support plate 100. The two support plates 100 (the first support plate 110 and the second support plate 120) are placed facing each other on the base with a slight gap therebetween.

Furthermore, the breaking mechanism section 200 serves to break the connecting rod 900 that is firmly attached to the base frame 40 and horizontally supported by the support plates 110, 120 (100).

The two support plates 110, 120 (100) are each equipped with a hydraulic cylinder (not shown), and can be moved toward or away from each other on the base. That is, by driving a hydraulic cylinder (not shown), the mandrel halves 131 and 132 fixed to the two support plates 110 and 120 (100) are separated from each other, so that the large diameter portion 920 of the connecting rod 900 The mandrel halves 131, 132 can be pressed against the inner peripheral surface of the opening.

Next, the structure of the mandrel 130 will be explained. As shown in FIGS. 1 and 2, the mandrel 130 consists of a pair of half-split mandrels that are fastened to the upper surfaces of the support plates 110 and 120 (100) through bolts.

A pedestal 150 on which the small diameter portion 910 of the connecting rod 900 is horizontally mounted is provided on the upper surface of the rear end side of the support plate 110. Further, a locate pin 151 stands up from the pedestal 150, and the locate pin 151 fits into the 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 breaking mechanism section 200 of the connecting rod 900 will be explained. The breaking mechanism section 200 of the connecting rod 900 is attached to the base frame 40. Further, a hydraulic cylinder 260 is vertically attached to the base frame 40. 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 designed to be driven vertically between the two mandrel halves 131 and 132 when the connecting rod breaks. Note that the large diameter portion breaking wedge 250 has two tapered portions formed symmetrically in the axial direction so as to match the tapered surfaces formed on the mandrel half portions 131 and 132 as described above. The large diameter portion breaking wedge 250 is raised and lowered by a hydraulic cylinder 260, and when lowered, it moves the mandrel halves 131 and 132 equally in directions away from each other.

The support plate 110 is also provided with hydraulic rod-type holding parts 171 and 172 (170) that hold down both shoulders 923 and 924 (see FIG. 1) on the small diameter side of the large diameter part 920 of the connecting rod 900, respectively. When the large diameter portion 920 is broken, both shoulder portions 923 and 924 on the small diameter portion side are pressed against the mandrel 130 side.

The clampers 510, 520 (500) press the bolt seating surfaces 921, 922 of the large diameter portion 920 before breaking the large diameter portion 920 of the connecting rod 900, and also hold the large diameter portion 921, 922 of the large diameter portion 920, which is broken into two when the large diameter portion 920 is broken. It serves to restrict movement of the portion 920 in a direction perpendicular to the central axis direction.

The clampers 510 and 520 (500) have a pair of identically shaped structures that respectively press the bolt seating surfaces 921 and 922 of the large diameter portion 920 of the connecting rod 900. Therefore, hereinafter, one clamper will be described as a reference numeral without parentheses, and the other clamper will be described as a reference numeral with parentheses. Further, in FIG. 2, only the symbols without parentheses are given, and in FIGS. 1, 3, and 4, the symbols without parentheses and the symbols with parentheses are written together.

The clamper 510 (520) includes a clamper body 511 (521) having a shaft shape with a large diameter, and a bolt seat surface pressing part 512 (522) that extends from the tip of the clamper body 511 (521) and has a smaller diameter than the clamper body 511 (521). , a hydraulic cylinder connecting part 514 (524) extending from the base end side of the clamper main body 511 (521), and a hydraulic cylinder connecting part 514 (524) to the clamper main body 511 (521) and the bolt seat pressing part 512. (522) relative to the bolt seat surface 921 (922) of the large diameter portion 920 of the connecting rod 900, and press the bolt seat pressing portion 512 (522) against the bolt seat surface 921 (922) or pull it away from it. The hydraulic cylinder 550 has a hydraulic cylinder 550. Note that the hydraulic cylinder 550 is firmly fixed to the support plate 120 via a fixing member 551. Further, a stepped portion formed at the connection portion between the clamper main body 511 (521) and the bolt seat pressing portion 512 (522) serves as a stopper contact portion 513 (523), which will be described later.

Further, as shown in FIG. 1, the hydraulic cylinder connecting portion 514 (524) is connected to the hydraulic cylinder 550 via a connecting plate 552, so that the operating force of the hydraulic cylinder 550 can be applied to both the clamper 510 (520). are simultaneously transmitted to the clampers 510 (520) so that both clampers 510 (520) move synchronously.

Note that the hydraulic cylinder 550 and the clamper main body 511 (521) are attached to one support plate 120. Further, a spring is interposed in the small diameter portion of each connecting portion that connects the clamper main body 511 (521) and the hydraulic cylinder 550.

In the vicinity of the stopper abutting portion 513 (523) of each clamper, there is provided a clamper pressing position defining mechanism 600, which is an important component in the present invention. The clamper holding position defining mechanism 600 determines the nominal value of the processing tolerance of the connecting rod 900 (FIGS. 3(b) and 4) before the large diameter portion 920 is broken, with the connecting rod 900 attached to the connecting rod breaking device 1. It serves to restrict the movement of the clamper 510 (520) so that the bolt seat pressing portion 512 (522) does not move (push too much) beyond the position that matches the dotted line N in (see dotted line N). Note that the nominal value of the machining tolerance here means the design reference value (display value), and does not mean the median value (average value) of the machining tolerance area.

The clamper holding position regulation mechanism 600 includes a stopper 610 (620), a stopper slide guide 630 (640) that firmly supports the stopper 610 (620) in a slidable state, and a stopper that slides the stopper 610 (620). It has an actuator 650 (660) for operation.

The stopper 610 (620) is made of, for example, a rectangular metal plate with excellent strength and durability and sufficient thickness, and its tip fits into the stepped portion of the stopper contact portion 513 (523). A notch 611 (621) is formed (see FIG. 3(c)), and the periphery of this notch 611 (621) abuts against the stepped portion of the stopper contact portion 513 (523), so that the connecting rod 900 when the stopper is activated. Further movement of the clamper 510 (520) toward the large diameter portion 920 of the clamper 510 (520) is restricted.

That is, as shown in FIG. 4(a), the connecting rod is machined to match the nominal value of the processing tolerance (see dotted line N in FIG. 4(a)), and as shown in FIG. 4(c). As shown, if the connecting rod is machined slightly to the negative side of the nominal value N of the machining tolerance (see dotted line Ny in Fig. 4(c)), the small diameter bolt seating surface of the clamper 520 (510) The portion 522 (512) passes through the notch 621 (611), and the tip of the large diameter clamper body 521 (511) is connected to the clamper body side of the stopper 620 (610) in which the notch 621 (611) is formed. As a result, the clamper 520 (510) is prevented from moving any further with respect to the bolt seating surface 922 (921) of the large diameter portion 920.

The stopper slide guide 640 (630) has a structure that allows the stopper 620 (610) to slide in a direction perpendicular to the movement direction of each clamper 520 (510) while firmly supporting the stopper 620 (610). There is.

Note that the holding force of the stopper 620 (610) by the stopper slide guide 640 (630) in the direction perpendicular to the moving direction of each clamper 520 (510) is different from that of the existing clamper holding position defining mechanism 600 according to the present invention. The holding force is sufficient to withstand a force equivalent to the pushing force of the clamper caused by the hydraulic actuator for operating the clamper, which is conventionally used in connecting rod breaking devices.

As a result, the hydraulic actuator for operating the clamper that has been conventionally used in the connecting rod breaking device 1 to which the present invention is applied can be used as is, and it is possible to eliminate the waste of specially designing this hydraulic actuator. Become.

Moreover, by forming the clamper holding position defining mechanism 600 into a unit, it becomes possible to retrofit the unit to an existing connecting rod breaking device if the mounting space for this unit can be secured. As a result, the problems described in the section of the problem to be solved by the present invention can be solved at once with respect to existing connecting rod breaking devices.

Although not specifically described in this embodiment, the stopper actuator 660 (650) is for sliding the stopper 620 (610) along the stopper slide guide 640 (630) with a predetermined stroke. . The specific configuration thereof is generally considered to be a hydraulic cylinder, but is not limited to this, and can take various forms such as a pneumatic cylinder, a combination of a motor and a speed reduction machine, a rack and pinion, etc.

Regarding both end positions of the movement stroke of the stopper 620 (610) that moves along the stopper slide guide 640 (630) by the stopper operation actuator 660 (650), when the clamper holding position defining mechanism 600 is not operating, the stopper 620 (610) is waiting in a non-operating position that does not inhibit the movement of the clamper 520 (510) by the hydraulic cylinder 550 (see the two-dot chain line in FIG. 3(c)), and the clamper holding position defining mechanism 600 has been activated. In this case, when the bolt seat pressing portion 522 (512) of the clamper 520 (510) then approaches the bolt seat surface 922 (921) of the connecting rod 900, the tip of the stopper 620 (610) and its vicinity reaches the operating position where it contacts the stopper contact portion 523 (513) of the clamper 520 (510) (see the solid line in FIG. 3(c)).

Note that when the large diameter portion 920 of the connecting rod 900 breaks while the tip of the stopper 620 (610) and its vicinity remain in a position where it contacts the stopper contact portion 523 (513) of the clamper 520 (510), Furthermore, the impact force at the time of breakage transmitted through the bolt seating surface 922 (921) of the large diameter portion 920 is absorbed by the hydraulic cylinder 550 only through the clamper 520 (510). That is, the impact force at the time of breakage is not transmitted to the stopper 620 (610).

While maintaining such a post-rupture state, the stopper 620 (610) is in contact with the stopper contact portion 523 (513) of the clamper 520 (510) before the large diameter portion 920 is fractured. The clamper 520 (510) restricts movement of the large diameter portion 920 in the direction toward the bolt seating surface 922 (921).

Next, a procedure for breaking the connecting rod 900 using the connecting rod breaking device 1 according to the present embodiment, that is, a method for manufacturing the broken connecting rod 900 will be described.

First, a connecting rod 900 before being broken is prepared. Then, the connecting rod 900 is attached to the support plates 110, 120 (100) on the base. As a result, the mandrel 130 is fitted into the large diameter portion 920 of the connecting rod 900, and the large diameter portion 920 is supported.

In this manner, the connecting rod 900 is attached to the connecting rod breaking device 1, and the mandrel 130 is engaged with the large diameter portion 920 of the connecting rod 900.

Then, the clamper holding position defining mechanism 600, which is a main part of the present invention, is activated. Specifically, the stopper 610 (620) is moved in a direction closer to the clamper 510 (520) along the stopper slide guide 630 (640) by the stopper actuator 650 (660). Then, the stopper 610 (620) is slid with a predetermined movement stroke of the stopper 610 (620), and when the position where the movement of the clamper 510 (520) is restricted is reached, the slide movement of the stopper 610 (620) is stopped. (See the arrows from the dotted line to the solid line in FIGS. 3(a), (b), and 3(c)).

Next, the clamper 510 (520) is moved toward the large diameter portion of the connecting rod by the driving force of the hydraulic cylinder. In the process of the clamper 510 (520) moving toward the bolt seat surface 921 (922) of the large diameter portion 920, the large diameter clamper main body 511 (521) and the smaller diameter bolt seat surface holding portion 512 (522) The stopper abutting part 513 (523) formed at the joint with the stopper 610 (620) hits the tip of the stopper 610 (620) and prevents further movement of the clamper 510 (520), so that the clamper 510 (520) does not move any further than the large diameter part 920. prevent it from moving toward the bolt seating surface 921 (922).

In this way, before breaking the large diameter portion 920 of the connecting rod 900, the clamper 510 (520) provided in the connecting rod breaking device 1 is used to break the connecting rod 900 when the large diameter portion of the connecting rod is broken. The displacement of the bolt seating surface 921 (922) of the large diameter portion 920 is suppressed.

At this time, as shown in FIG. 4(b), if the connecting rod 900 is machined to the plus side within the range of the processing tolerance than the nominal value of the processing tolerance (see dotted line N in FIG. 4(b)). (See dotted line N + 520 (510), the large diameter portion 920 of the connecting rod 900, which is defined as positive within the range of processing tolerances regarding the pressing force, is The large diameter portion 920 of the connecting rod 900, which has shifted toward the clamper by a slight amount (specifically, about several tens of microns) that deviates from the designed nominal value, is pressed down.

As a result, the large diameter portion 920 of the connecting rod 900, which has been machined with an allowable amount of deviation from the nominal value defined by the plus side of the machining tolerance, is fixed to the bolt seating surface pressing portion of the clamper 520 (510). 522 (512) to hold it down. As a result, the bolt seat surface 922 (921) is prevented from being pressed by the clamper 520 (510) in excess of the upper limit value of the pressing force that is necessarily specified in this state.

That is, since the stopper 620 (610) regulates the forward position of the clamper 520 (510) so that the movement of the clamper 520 (510) is stopped at the position corresponding to the nominal value, the hydraulic cylinder and the clamper are This prevents the bolt seating surface 922 (921) of the large diameter portion 920 from being pushed with undesirably large force.

Furthermore, as shown in FIG. 4(a), when the connecting rod 900 to be attached matches the nominal value of the machining tolerance (see dotted line N in FIG. 4(a)), the clamper 520 (510) is moved by the action of the stopper. The bolt seat surface holding portion 522 (512) is in a state where its tip surface 522a (512a) only contacts the bolt seat surface 922 (921) of the large diameter portion 920, and the state is such that the large diameter portion 920 of the connecting rod 900 is not broken. Undesirable pressing force is no longer applied to the bolt seat surface 922 (921) via the bolt seat surface pressing portion 522 (512) of the clamper 520 (510).

On the other hand, as shown in FIG. 4(c), if the connecting rod 900 is machined to the negative side within the range of the processing tolerance than the nominal value of the processing tolerance (see dotted line N in FIG. 4(c)). 4(c)), when pressing the bolt seat surface 922 (921) of the large diameter portion 920 of the connecting rod 900 with the clamper 520 (510), there is a gap of about several tens of microns between the large diameter portion 920. These occur between each bolt seat surface 922 (921) and the tip surface 522a (512a) of the bolt seat surface pressing portion 522 (512) of the clamper 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 undesirable pressing force is applied to the bolt seating surface 922 (921) before the large diameter portion 920 of the connecting rod 900 breaks. It is no longer necessary to apply the bolt via the bolt seat pressing portion 522 (512) of the clamper 520 (510).

In the case shown in FIG. 4(c), even if an impact force is instantaneously applied to the broken large diameter portion 920 on the bolt seating surface side when the large diameter portion 920 breaks, the bolt seating surface 922 (921 ) and the tip surface 522a (512a) of the bolt seat surface holding part 522 (512) of the clamper 520 (510), since only a gap of about several tens of microns is created before the rupture. The bolt seating surface 922 (921) of the large diameter portion 920 after being broken can be held by the clamper 520 (510) without causing even the slightest movement on the bolt seating surface side of the portion.

As a result, on the bolt seating surface side of the large-diameter portion 920 after fracture, there is no undesirable deviation, for example, along the circumference of the mandrel half that it contacts, and such deviation causes the fractured surfaces to collide with each other and cause damage to each other. There is no risk that this will happen.

Sharing such advantages unique to the present invention, the large diameter portion 920 of the connecting rod 900 is divided into two by driving the large diameter portion breaking wedge 250 into the mandrel 130. At the time of this breakage, as described above, the stopper 620 (610) of the clamper holding position defining mechanism 600 does not receive the impact force when the large diameter portion 920 of the connecting rod 900 breaks.

That is, this impact force is transmitted only to the hydraulic cylinder 550 that operates the clamper 520 (510), and the impact force is completely absorbed by this hydraulic cylinder 550. Therefore, the clamper holding position defining mechanism 600 will not be adversely affected by the impact force at the time of breakage.

After absorbing the impact force with the hydraulic cylinder 550 in this way, the stopper 610 (620) is moved backward along the stopper slide guide 630 (640) (moved in the opposite direction to the arrow in FIG. 3(c)), and the clamper The holding position defining mechanism 600 is brought into a non-operating state. Thereafter, the broken connecting rod is taken out and carried out according to normal procedures.

By preparing the connecting rod 900 before breaking as described above and manufacturing the connecting rod 900 in which the large diameter portion 920 is divided into two parts using the connecting rod breaking method according to the present invention, the following effects can be achieved. can.

Specifically, according to the present invention, the clamper provided in the connecting rod breaking device is no longer used to press down the bolt seating surface of the large diameter portion of the connecting rod beyond a predetermined pressing force within a predetermined range. .

This makes it possible to solve all the problems described in the column of problems to be solved by the present invention. Specifically, by clamping the clamper in a so-called push-out state using the pressure of a hydraulic cylinder, extra force is applied to the connecting rod, causing the connecting rod to break while being distorted (deformed). You can avoid things that would be confusing. As a result, the large diameter part will not break into two parts with undesirable internal stress remaining at the time of rupture. prevent the occurrence of

This prevents the breakage end position of the large diameter portion from being deviated from the normal preferred state, or the breakage surface not being an ideal breakage surface that matches the design value. More specifically, for example, it is possible to prevent a problem in which the break end position of the large diameter portion is not formed in accordance with the design regulations so as to correspond to the break start position of the large diameter portion, or to prevent the failure. To prevent a cross section from becoming a three-dimensionally wavy fracture surface instead of an ideal fracture surface that matches design values. As a result, it is possible to avoid the problem of a decrease in yield, and to form a prescribed fracture surface with a high yield when breaking the large diameter portion of the connecting rod into two parts.

Further, by unitizing the clamper holding position regulating mechanism, it becomes possible to retrofit the unit to an existing connecting rod breaking device if the mounting space for this unit can be secured. As a result, the problems described in the section of the problem to be solved by the present invention can be solved at once with respect to existing connecting rod breaking devices.

It goes without saying that the scope of the present invention is not limited to the embodiments described above. In other words, even if it has a form different from the embodiment described above, it is within the scope of the present invention as long as it has a configuration that applies to the creation of the technical idea specified in the present invention and exhibits its effects. It is naturally included.

Specifically, in the above-described embodiment, for example, the hydraulic cylinder may be a connecting rod breaking device having a configuration such that it is located above the connecting rod. Alternatively, the connecting rod breaking device may have a configuration in which the upper side of the connecting rod is held down by a connecting rod upper surface holding plate. Alternatively, a connecting rod breaking device may be used in which the base plate is provided on the outer periphery of the turntable.

The present invention relates to a casing for holding or fixing crankshafts, bearings, etc. that have an axial, shaft-like, or cylindrical outer shape by sandwiching them therein. Naturally, the invention can be applied to all technical fields in which a mandrel is inserted into a circular end-view receiving portion for a shaft, and a wedge is driven into the mandrel to break the casing in two.

As explained above, in the present invention, in order to firmly hold the bolt seating surface after the large diameter portion of the connecting rod breaks, the bolt is pressed by a so-called push-cut using a hydraulic mechanism via a clamper before the breakage. We realized that this caused excessive internal stress in the large diameter part of the steel, and that this was a factor that hindered the formation of a clean fracture surface as specified in the design and the formation of the specified fracture end position when the material broke. Based on this knowledge, we solved this problem by using a special holding position mechanism for the clamper, which has great technical significance.

More specifically, we will focus on phenomena that may occur due to a special form of processing that occurs dynamically and extremely instantaneously, such as the breaking of the large diameter portion of a connecting rod by a combination of a wedge and a mandrel. The half of the large diameter part that is separated from the small diameter part is displaced along the mandrel half with which the inner peripheral surface comes into contact due to the instantaneous breaking force, and the fracture surface with the opposing half after the breakage. In order to prevent problems such as contact between bolts and damage to the fractured surface, the two bolt seating surfaces on the large diameter part are firmly pressed down using the pushing force of a hydraulic cylinder via a clamper. However, the inventor of the present invention discovered that the measures taken to prevent the problem after the fracture actually had an invisible negative effect on the large diameter portion of the connecting rod before the fracture, and based on this knowledge, the present invention was developed. It can be said that there is great technical significance in taking such measures.

1 Connecting rod breaking device 40 Base frame 50 Base 110, 120 (100) Support plate (support member)
130 Mandrel 131, 132 Mandrel half 150 Pedestal 151 Locate pin 171, 172 (170) Rod type holding part 200 Breaking mechanism part 250 Large diameter part breaking wedge 260 Hydraulic cylinder 261 Rod 510, 520 (500) Clamper 511, 521 Clamper main body 512, 522 Bolt seating surface holding part 512a, 522a Tip surface 513, 523 Stopper contact part 514, 524 Hydraulic cylinder connecting part 550 Hydraulic cylinder 551 Fixing member 552 Connection plate 600 Clamper holding position defining mechanism 610 (620) Stopper 611 (621 ) Notch part 630 (640) Stopper slide guide 650 (660) Stopper actuator 900 Connecting rod 910 Small diameter part 920 Large diameter part 921, 922 Bolt seating surface 923, 924 Both shoulders on small diameter part side

Claims (4)

A connecting rod that engages a mandrel with a large diameter portion of the connecting rod and drives a connecting rod breaking wedge into the mandrel along the central axis of the large diameter portion of the connecting rod to divide the large diameter portion of the connecting rod into two. In the breaking device of
Before breaking the large diameter part of the connecting rod attached to the breaking device, hold down the bolt seating surface of the large diameter part, and press the large diameter part that is to be broken into two parts at the time of breaking into the large diameter part. In addition to being equipped with a clamper to restrict movement in a direction perpendicular to the central axis direction of the
With the connecting rod attached to the connecting rod breaking device, the position of the clamper holding the large diameter portion remains at a position that matches a nominal value of the processing tolerance of the connecting rod before the large diameter portion is broken. A connecting rod breaking device equipped with a clamper holding position regulating mechanism for regulating the movement of the clamper,
The clamper is configured to move toward the bolt seating surface by the driving force of a hydraulic cylinder, and a stopper provided in the clamper holding position defining mechanism is arranged to move toward the large diameter portion of the connecting rod attached to the breaking device. By regulating the forward position of the clamper to stay at a position corresponding to the nominal value before breaking the clamper, the forward position of the clamper due to the driving force of the hydraulic cylinder does not exceed the position corresponding to the nominal value. A connecting rod breaking device characterized in that the stopper prevents the clamper from moving forward . Using a connecting rod breaking device, drive a connecting rod breaking wedge into the mandrel engaged with the large diameter portion of the connecting rod along the central axis of the large diameter portion of the connecting rod, thereby splitting the large diameter portion into two. In the connecting rod breaking method for manufacturing connecting rods,
attaching the connecting rod to the connecting rod breaking device, and engaging the mandrel with the large diameter portion of the connecting rod;
Before breaking the large diameter portion of the connecting rod, use a clamper provided in the connecting rod breaking device to press the bolt seating surface of the large diameter portion of the connecting rod with a pressing force within a predetermined range. , With the connecting rod attached to the connecting rod breaking device, the nominal machining tolerance of the connecting rod is determined before breaking the large diameter portion using a clamper holding position defining mechanism provided in the connecting rod breaking device. A connecting rod whose large diameter portion is divided into two by driving a wedge for breaking the connecting rod into the mandrel while regulating the movement of the clamper so that the position of the clamper holding the large diameter portion remains at a position that matches the value. A method for breaking a connecting rod for manufacturing ,
The clamper is configured to move toward the bolt seating surface by the driving force of a hydraulic cylinder, and a stopper provided in the clamper holding position defining mechanism is arranged to move toward the large diameter portion of the connecting rod attached to the breaking device. By regulating the forward position of the clamper to stay at a position corresponding to the nominal value before breaking the clamper, the forward position of the clamper due to the driving force of the hydraulic cylinder does not exceed the position corresponding to the nominal value. A method for breaking a connecting rod, characterized in that the forward movement of the clamper is prevented by the stopper . Prepare the connecting rod before breaking,
Attaching the connecting rod to the connecting rod breaking device according to claim 1,
A method for manufacturing a connecting rod, comprising manufacturing a connecting rod whose large diameter portion is divided into two by using the connecting rod breaking device. Prepare the connecting rod before breaking,
A method for manufacturing a connecting rod, comprising manufacturing a connecting rod whose large diameter portion is divided into two by the method for breaking a connecting rod according to claim 2.

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