Piston ring cutting-off device

Abstract

The present invention comprises a holding part that holds a stacked body in which piston rings have been stacked in the axial direction, a cutting-off part that delivers the tip-end piston ring from the stacked body, and a detection unit that detects the boundaries between adjacent piston rings in the stacked body, wherein: the cutting-off part has a movement part that moves a push-out part and a restriction part; and the movement part inserts the push-out part and the restriction part into a separation site that is the boundary between the piston ring at the tip end of the stacked body and the piston ring adjacent to the tip-end piston ring and then, in a state in which the restriction part restricts the piston ring adjacent to the tip end piston ring from moving in the delivery direction in which the tip-end piston ring is to be delivered, moves the push-out part in the delivery direction, whereby the tip-end piston ring is separated from the stacked body and is delivered along the holding part.

Description

Technical Field

[0001] The present invention relates to a cutting-outapparatus for a piston ring mounted on a piston of aninternal combustion engine.Background Art

[0002] An internal combustion engine mounted on atypical automobile adopts a configuration in which acombination of piston rings including a compression ring(pressure ring) and an oil ring is fitted to ring groovesformed in a piston. As the oil ring, a combination oilring composed of a pair of segments (also referred to asside rails) and a spacer expander urging the pair ofsegments is known. In processes of manufacturing andmachining the piston rings and a process of assemblingthe piston rings to the ring grooves of the piston, apiston ring at the tip end is cut out sequentially one byone from a plurality of piston rings in a stacked form.For example, Patent document 1 discloses an assemblingapparatus for piston rings that cuts out a piston ring atthe uppermost layer (tip end) of a plurality of pistonrings (segments) retained in a layered form in amagazine. The apparatus includes a pair of cutting-outclaws and causes one cutting-out claw of the pair ofcutting-out claws to engage with a segment at theuppermost end of the segments in the layered form priorto the other cutting-out claw so that the segment can beprecisely cut out.Citation listPatent document

[0003] [Patent document 1] Japanese Patent Laid-OpenNo. 2005-111599[Patent document 2] Japanese Patent Laid-Open No. 2-75745[Patent document 3] Japanese Patent Laid-Open No. 4-173625Summary of the InventionTechnical Problem

[0004] However, there has been a potential defectappearing in conventional art that when the width(thickness in the axial direction) of the piston ring isnarrow, the adjacent piston rings cannot be successfullyseparated in cutting out, thereby failing to cut out thepiston rings one by one, and a technique of more surelycutting out the piston rings one by one has been desired.

[0005] The present invention has been made in view ofthe aforementioned problem and the objective is toprovide a technique capable of surely cutting out pistonrings one by one in cutting out the piston rings.Solution to Problem

[0006] To solve the aforementioned problem, thepresent invention adopts the following means. That is,the present invention is a cutting-out apparatus for apiston ring including a retaining unit extending in arail form that is inserted into a hollow part of acylindrical stack body formed of a plurality of pistonrings stacked in an axial direction so as to retain thestack body, a cutting-out unit that separates a pistonring at a tip end of the stack body from the stack bodyretained by the retaining unit and delivers the pistonring at the tip end along the retaining unit, and adetecting unit that detects a boundary between the pistonrings that are adjacent to each other in the stack body,in which the cutting-out unit includes a pushing-outunit, a restricting unit, and a moving unit that movesthe pushing-out unit and the restricting unit, and afterinserting the pushing-out unit and the restricting unitinto a dividing portion that is a boundary between thepiston ring at the tip end and a piston ring that isadjacent to the piston ring at the tip end in the stackbody based on a detection result of the detecting unit,in a state in which movement of the piston ring that isadjacent to the piston ring at the tip end in adelivering direction in which the piston ring at the tipend is delivered is restricted by the restricting unit,the moving unit moves the pushing-out unit in thedelivering direction, so that the piston ring at the tipend is separated from the stack body, and the piston ringat the tip end is delivered along the retaining unit.

[0007] According to the cutting-out apparatusaccording to the present invention, the detecting unitdetects a boundary between the piston rings that areadjacent to each other, so that even when a step(positional deviation in the axial direction of thepiston ring at an abutment between opposite ends of thepiston ring) is formed at the abutment of the pistonring, the pushing-out unit and the restricting unit canbe inserted into the dividing portion. Further, afterinserting the pushing-out unit and the restricting unitinto the dividing portion, in a state in which movementof the piston ring that is adjacent to the piston ring atthe tip end in the stack body in the delivering directionis restricted by the restricting unit, the piston ring atthe tip end is moved in the delivering direction by thepushing-out unit, so that the piston ring at the tip endcan be surely separated from the stack body. In thismanner, the piston rings can be surely cut out from thestack body one by one.

[0008] Further, in the present invention, theretaining unit may retain the plurality of piston ringssuch that abutments of the plurality of piston rings arealigned so as to form a slit in the stack body extendingin the axial direction of the stack body, the pushing-outunit and the restricting unit may be inserted into thedividing portion in a direction from the slit toward thehollow part of the stack body, the stack body may besectioned into a first region and a second region by theslit as seen in a direction in which the pushing-out unitand the restricting unit are inserted into the dividingportion, the pushing-out unit may include a firstpushing-out claw inserted into the dividing portion inthe first region and a second pushing-out claw insertedinto the dividing portion in the second region, and therestricting unit may include a first restricting clawinserted into the dividing portion in the first regionand a second restricting claw inserted into the dividingportion in the second region.

[0009] That is, the cutting-out apparatus according tothe present invention may be configured such that thepushing-out unit and the restricting unit are insertedinto the dividing portion in each of the first region andthe second region that are regions sandwiching the slit.When the positions of the opposite ends of the pistonring at the abutment are deviated from each other in theaxial direction, the adjacent piston rings in the stackbody are more likely to be entangled near the abutments.Meanwhile, in the present invention, the pushing-out unitand the restricting unit are inserted into both sides ofthe abutment (slit) to perform operation of separatingthe piston rings on both sides of the abutment, so thatthe piston ring at the tip end can be surely separatedfrom the stack body. In this manner, the piston ringscan be more surely cut out from the stack body one byone.

[0010] Further, in the present invention, thedetecting unit may acquire images of the first region andthe second region and detect the dividing portion in eachof the first region and the second region based on theimages acquired.

[0011] According to the present invention, thedividing portion is detected in each of the first regionand the second region, so that the pushing-out unit andthe restricting unit can be surely inserted into thedividing portion in each of the first region and thesecond region.

[0012] Furthermore, in the present invention, themoving unit may include an insertion member that moves ina direction in which the pushing-out unit and therestricting unit are inserted into the dividing portionof the stack body, and the pushing-out unit and therestricting unit may be coupled to the insertion membersuch that the pushing-out unit and the restricting unitcan be displaced relative to the insertion member in theaxial direction of the piston rings in the stack body.

[0013] According to the present invention as such,when inserting the pushing-out unit and the restrictingunit into the dividing portion, any deviation between thepositions of the pushing-out unit and the restrictingunit and of the dividing portion in the deliveringdirection or any deviation angle when the pushing-outunit and the restricting unit are inclined relative tothe inserting direction can be accepted, so thatinserting the pushing-out unit and the restricting unitinto the dividing portion can be facilitated. In thismanner, the pushing-out unit and the restricting unit canbe surely inserted into the dividing portion.

[0014] The present invention is applicable to cuttingout of the piston ring. The piston ring to be cut out inthe present invention includes a segment for use in acombination oil ring including the segment and a spacerexpander, a compression ring, and the like.Advantageous Effects of Invention

[0015] According to the present invention, pistonrings can be surely cut out one by one in cutting out thepiston rings.Brief Description of the Drawings

[0016] [Fig. 1] Fig. 1 is a side view of a cutting-outapparatus according to an embodiment.[Fig. 2] Fig. 2 is a front view of a portion with adotted line of Fig. 1.[Fig. 3] Fig. 3 is a top view of a stack bodyretained by a retaining unit.[Fig. 4] Fig. 4 is a flowchart of a method forcutting out a piston ring by the cutting-out apparatus.[Fig. 5] Fig. 5 is a side view of the cutting-outapparatus for explaining an image acquiring step.[Fig. 6] Fig. 6 is a view illustrating an example ofan image acquired by a camera.[Fig. 7] Fig. 7 is a side view (1) of the cutting-outapparatus for explaining an inserting step.[Fig. 8] Fig. 8 is a top view illustrating apositional relation between a pushing-out unit and arestricting unit and the stack body in the insertingstep.[Fig. 9] Fig. 9 is a side view (2) of the cutting-outapparatus for explaining the inserting step.[Fig. 10] Fig. 10 is an enlarged cross-sectionalview of a dividing portion of the cutting-out apparatusin the inserting step.[Fig. 11] Fig. 11 is a side view (1) of the cutting-out apparatusfor explaining a separating step.[Fig. 12] Fig. 12 is a side view (2) of the cutting-out apparatusfor explaining the separating step.[Fig. 13] Fig. 13 is a top view illustrating apositional relation between the pushing-out unit and therestricting unit and the stack body in the separatingstep.[Fig. 14] Fig. 14 is a side view of the cutting-outapparatus for explaining a transferring step.Description of Embodiments

[0017] Hereinafter, an embodiment of a cutting-outapparatus for a piston ring (hereinafter also simplyreferred to as a cutting-out apparatus) according to thepresent invention will be described. A cutting-outapparatus 100 described below is an application of thepresent invention to cutting out a segment for use in acombination oil ring. The segment is an example of thepiston ring to be cut out in the present invention, andthe present invention is also applicable to a cutting-outapparatus for a compression ring other than the segment.Further, the technical scope of the invention is notlimited to only the configurations described in theembodiment below unless otherwise particularly stated.

[0018] Fig. 1 is a side view of the cutting-outapparatus 100 according to the embodiment. Further, Fig.2 is a front view of a portion with a dotted line of Fig.1. The cutting-out apparatus 100 forms a supply line fora segment 200 in a manufacturing process for a pistonring. The segment 200 is a constituent member of acombination oil ring. The combination oil ring includesa pair of segments 200, 200 and a spacer expander urgingthe pair of segments 200, 200, and is fitted to a ringgroove formed on an outer periphery surface of a pistonin an internal combustion engine so as to controllubrication for a cylinder and the piston ring. Thecutting-out apparatus 100 cuts out the segments 200sequentially one by one from a stack body 300 with aplurality of segments 200 cylindrically stacked andsupplies the segments 200 to a line in the followingstep. Hereinafter, the configuration of the cutting-outapparatus 100 will be described.

[0019] [Apparatus configuration]As illustrated in Fig. 1 and Fig. 2, the cutting-outapparatus 100 includes a retaining unit 10, a cutting-outunit 20, a camera 30, a pusher 40, a stopper 50, a railmoving unit 60, and a control device 70.

[0020] As illustrated in Fig. 1 and Fig. 2, theretaining unit 10 is a member in a rail form horizontallydisposed and extending in the front-back direction, andis inserted into the segments 200 so as to retain thesegments 200 in a suspending manner. The plurality ofsegments 200 retained by the retaining unit 10 is stackedin the front-back direction (extending direction of theretaining unit 10) so as to form the cylindrical stackbody 300. The center axis A1 of the stack body 300 isparallel to the extending direction of the retaining unit10. That is, the plurality of segments 200 is stacked inthe axial direction of the segments 200. In the stackbody 300, the plurality of segments 200 is arranged withalmost no gap. As illustrated in Fig. 2, the retainingunit 10 is in a state of being inserted through a hollowpart H1 of the stack body 300.

[0021] Further, as illustrated in Fig. 2, theretaining unit 10 includes an extension part 101 in asubstantially rectangular shape in a cross-sectional viewextending in the front-back direction and a raised part102 raised on an upper surface of the extension part 101and extending in the front-back direction. The extensionpart 101 engages with an inner periphery surface of thesegment 200 and the raised part 102 is inserted into anabutment G1 of the segment 200, so that the segment 200is retained in a suspending manner with the abutment G1on the upper side. The raised part 102 is inserted intothe abutment G1 of the segment 200, so that the rotationof the segment 200 and the stack body 300 about the axisis restricted. The segment 200 can slide along theretaining unit 10 while the abutment G1 is guided by theextension part 101.

[0022] Furthermore, as illustrated in Fig. 1, theretaining unit 10 is divided into front and rearportions. Of the retaining unit 10 divided into thefront and rear portions, the portion on the rear side isa first rail 10A and the portion on the front side is asecond rail 10B. The stack body 300 is retained by thefirst rail 10A. Although the detail will be describedlater, the retaining unit 10 can be in a state of thefirst rail 10A and the second rail 10B connected togetherand in a state of the first rail 10A and the second rail10B separated, by the second rail 10B moving in thefront-back direction along with the front-back movementof a rail moving unit 60.

[0023] Fig. 3 is a top view of the stack body 300retained by the retaining unit 10. The rotation of thesegment 200 about the axis is restricted by a secondpushing-out claw 12, so that the abutments G1 of theplurality of segments 200 are aligned in the axialdirection as illustrated in Fig. 3. With the pluralityof abutments G1 continuously arranged in the axialdirection, a slit depicted by a reference sign S1extending in the axial direction is formed in the stackbody 300. Further, as illustrated in Fig. 3, in a topview, the stack body 300 is sectioned into a first regionR1 and a second region R2 by the slit S1. Hereinafter,of the plurality of segments 200 forming the stack body300, the segment 200 at the tip end (front end) is afirst segment 201 and the segment 200 adjacent to thefirst segment 201, that is, the segment 200 that is thesecond from the tip end, is a second segment 202.Furthermore, in the stack body 300, a boundary betweenthe first segment 201 and the second segment 202 is adividing portion P1. The dividing portion P1 is acontacting section or a gap between the first segment 201and the second segment 202 and is a portion where thestack body 300 is divided for cutting out the firstsegment 201 from the stack body 300.

[0024] Here, in general, the piston ring may bemanufactured in a shape in which the opposite ends aredeviated in the axial direction like a spring lock washerdue to deformation at the time of forming. Thisdeformation tends to increase as the width (thickness) inthe axial direction becomes narrower like the segment.In the present embodiment, as illustrated in Fig. 3, dueto deformation of the segment 200 at the time of forming,opposite ends 200a, 200b forming the abutment G1 form astep in the axial direction of the segment 200. That is,the positions of the opposite ends 200a, 200b of thesegment 200 at the abutment G1 are deviated from eachother in the axial direction. Therefore, the position inthe front-back direction of the dividing portion P1differs between the first region R1 and the second regionR2 sandwiching the slit S1. In the present example, thedividing portion P1 in the first region R1 is positionedon the front side relative to the dividing portion P1 inthe second region R2, but the present invention is notlimited to this. The positions of the opposite ends200a, 200b of the segment 200 at the abutment G1 may bedeviated relative to each other in the axial directionsuch that the dividing portion P1 in the first region R1is positioned on the rear side relative to the dividingportion P1 in the second region R2.

[0025] The cutting-out unit 20 cuts out the firstsegment 201 from the stack body 300 and delivers thefirst segment 201 forward along the retaining unit 10.As illustrated in Fig. 1, the cutting-out unit 20includes a pushing-out unit 1, a restricting unit 2, anda moving unit 3.

[0026] The pushing-out unit 1 is a member to beinserted into the dividing portion P1 in the stack body300 and then to move forward (in the delivering directionof the first segment 201) so as to push the first segment201 forward. The restricting unit 2 is a member to beinserted into the dividing portion P1 in the stack body300 together with the pushing-out unit 1 and to restricta forward movement of the second segment 202 so as toseparate the first segment 201 and the second segment202. As illustrated in Fig. 2, the pushing-out unit 1and the restricting unit 2 are inserted into the stackbody 300 from the upper side of the stack body 300. Thedirection in which the pushing-out unit 1 and therestricting unit 2 are inserted into the stack body 300corresponds to a direction from the slit S1 (abutment G1)toward the hollow part H1 (more specifically, the centeraxis A1 of the stack body) of the stack body 300.

[0027] Further, as illustrated in Fig. 2, the pushing-outunit 1 is composed of a pair of pushing-out claws 11,12, and the restricting unit 2 is composed of a pair ofrestricting claws 21, 22. The pair of pushing-out claws11, 12 and the pair of restricting claws 21, 22 arecutting-out edges extending in the up-down direction withthe lower ends inclined and are provided orthogonally tothe axial direction of the segment 200 in the stack body300 so as to be able to be inserted into the dividingportion P1. The first pushing-out claw 11 as one of thepair of pushing-out claws 11, 12 is inserted into thedividing portion P1 in the first region R1, and thesecond pushing-out claw 12 as the other is inserted intothe dividing portion P1 in the second region R2.Furthermore, the first restricting claw 21 as one of thepair of restricting claws 21, 22 is inserted into thedividing portion P1 in the first region R1, and thesecond restricting claw 22 as the other is inserted intothe dividing portion P1 in the second region R2. Here,as illustrated in Fig. 2, the pair of restricting claws21, 22 are disposed on the outer sides of the pair ofpushing-out claws 11, 12, respectively. Therefore, thepair of pushing-out claws 11, 12 are inserted intopositions closer to the slit S1 (abutment G1) as comparedto the pair of restricting claws 21, 22. In the presentembodiment, the pushing-out claws 11, 12 are positionedcloser to the slit S1 (abutment G1) as compared to therestricting claws 21, 22, but the restricting claws 21,22 may be positioned closer to the slit S1 (abutment G1)as compared to the pushing-out claws 11, 12. Inaddition, the number of the pushing-out claws and therestricting claws need not to be two for each (pair).The number of the pushing-out claws and the restrictingclaws may be one for each or may be three or more.Further, the numbers of the pushing-out claws and therestricting claws may not be the same.

[0028] The moving unit 3 moves the pushing-out unit 1and the restricting unit 2 so as to cut out the firstsegment 201. As illustrated in Fig. 2, the moving unit 3includes a moving mechanism 4 corresponding to each ofthe pair of pushing-out claws 11, 12 and the pair ofrestricting claws 21, 22. Hereinafter, the movingmechanism 4 for moving the first pushing-out claw 11 isreferred to as a moving mechanism 4A, the movingmechanism 4 for moving the second pushing-out claw 12 asa moving mechanism 4B, the moving mechanism 4 for movingthe first restricting claw 21 as a moving mechanism 4C,and the moving mechanism 4 for moving the secondrestricting claw 22 as a moving mechanism 4D, and whendescription is made without distinguishing these, theyare simply referred to as the moving mechanism 4. Themoving mechanism 4A, the moving mechanism 4B, the movingmechanism 4C, and the moving mechanism 4D areindependently controlled by the control device 70. Asillustrated in Fig. 1, the moving mechanism 4 includes afirst linear actuator 41, a first moving body 42, asecond moving body 43, a second linear actuator 44, acoupling member 45, an arm 46, and a linear guide 47.

[0029] The first linear actuator 41 is configured witha servo motor controlled by the control device 70, a ballscrew driven by the servo motor to rotate, a travelingbody that reciprocates in the front-back direction alongwith the rotation of the ball screw, a linear guide thatguides the front-back movement of the traveling body, andthe like. The first moving body 42 is a plate-likemember that is coupled to the first linear actuator 41and that moves in the front-back direction in accordancewith the driving of the first linear actuator 41. Thesecond moving body 43 is a plate-like member that iscoupled to the first moving body 42 via the linear guide47. The second linear actuator 44 is a linear actuatorcontrolled by the control device 70. The second linearactuator 44 includes a rod 441 that reciprocates in theup-down direction. The coupling member 45 is a memberthat couples the second moving body 43 and the rod 441.With the second moving body 43 and the rod 441 coupledtogether, the second moving body 43 moves in the up-downdirection in accordance with the driving of the secondlinear actuator 44. In the present embodiment, afloating joint utilizing a spherical surface contact isused as the coupling member 45. The linear guide 47 is amember that guides the up-down movement of the secondmoving body 43. In the present embodiment, an LM guide(Registered Trademark) utilizing the rolling of a ball isused as the linear guide 47. The arm 46 is a member thatcouples the second moving body 43 with the pushing-outunit 1 and the restricting unit 2. The arm 46 extendsforward from the second moving body 43, and upper ends ofthe pushing-out unit 1 and the restricting unit 2 areconnected to a lower surface of a tip end of the arm 46.The first moving body 42 moves in the front-backdirection in accordance with the driving of the firstlinear actuator 41, so that the pushing-out unit 1 andthe restricting unit 2 move in the front-back direction.Further, the second moving body 43 moves in the up-downdirection in accordance with the driving of the secondlinear actuator 44, so that the pushing-out unit 1 andthe restricting unit 2 move in the up-down direction.

[0030] The camera 30 is an image capturing device thatis disposed above the retaining unit 10 together with anillumination device (not illustrated) and that capturesan image of the stack body 300 in accordance with thecontrol by the control device 70 to acquire the image.As illustrated in Fig. 2, the cutting-out apparatus 100includes two cameras 30A, 30B, the camera 30A acquiringan image of the first region R1 of the stack body 300,the camera 30B acquiring an image of the second regionR2.

[0031] The pusher 40 and the stopper 50 are membersthat move in the front-back direction in accordance withthe control by the control device 70 to contact thesegment 200 and the stack body 300 so as to position thesegment 200 and the stack body 300. The pusher 40 isdisposed on the rear side of the stack body 300, and thestopper 50 is disposed on the front side of the stackbody 300.

[0032] The rail moving unit 60 is a member thatsupports the second rail 10B and moves in the front-backdirection in accordance with the control by the controldevice 70 so as to move the second rail 10B in the front-backdirection. The rail moving unit 60 is configuredwith a servo motor, a ball screw, a traveling body, alinear guide, and the like.

[0033] The control device 70 includes a processor suchas a CPU (Central Processing Unit), an I / O interface, andthe like, and controls the cutting-out unit 20, thecamera 30, the pusher 40, the stopper 50, and the railmoving unit 60 by executing predetermined programs. Thecontrol device 70 includes, as a processing unit, acontrol unit 701 and a detecting unit 702. The controlunit 701 controls the cutting-out unit 20, the pusher 40,the stopper 50, and the rail moving unit 60. Thedetecting unit 702 detects a boundary between thesegments 200 that are adjacent to each other in the stackbody 300 based on the image acquired by the camera 30.The details of the processing executed by the detectingunit 702 will be described later.

[0034] [Method for cutting out piston ring]Hereinafter, a method for cutting out the firstsegment 201 (method for cutting out the piston ring) atthe tip end from the stack body 300 using the cutting-outapparatus 100 will be described. Fig. 4 is a flowchartof the method for cutting out the piston ring by thecutting-out apparatus 100. First, in an image acquiringstep of step S10, images of the first region R1 and thesecond region R2 of the stack body 300 are acquired bythe camera 30. Fig. 5 is a side view of the cutting-outapparatus 100 for explaining the image acquiring step.In the image acquiring step, first, the stack body 300 ispositioned at a predetermined image capturing positionwithin the field of view of the camera 30. The stackbody 300 is positioned by the pusher 40 and the stopper50. Specifically, the pusher 40 is advanced by thecontrol of the control unit 701 of the control device 70so as to push the stack body 300 forward bringing it intocontact with the stopper 50 standing by at apredetermined position. In this manner, as illustratedin Fig. 5, the stopper 50 contacts the front end (firstsegment 201) of the stack body 300, and the pusher 40contacts the rear end of the stack body 300 so that thestack body 300 is positioned at the image capturingposition. With the stack body 300 positioned at theimage capturing position, an image of the first region R1is captured by the camera 30A, and an image of the secondregion R2 is captured by the camera 30B so as to acquirethe images of the first region R1 and the second regionR2. Fig. 6 is a view illustrating an example of an imageacquired by the camera 30. In Fig. 6, as an example, animage of the first region R1 acquired by the camera 30Ais illustrated. As illustrated in Fig. 6, the camera 30acquires an image including at least a boundary B1between the first segment 201 and the second segment 202.

[0035] Next, in a dividing portion detecting step ofstep S20, the detecting unit 702 of the control device 70acquires the images of the first region R1 and the secondregion R2 from the camera 30 and detects the dividingportion P1 in each of the first region R1 and the secondregion R2. Here, as illustrated in Fig. 6, in the stackbody 300, there is a plurality of boundaries between thesegments 200 that are adjacent to each other. Of theplurality of boundaries, the n-th (n is an integer)boundary from the tip end side (front end side) of thestack body 300 is a boundary Bn. In image processingperformed by the detecting unit 702, the acquired imageis subjected to an edge detection for detecting theboundary between the segments 200 in the stack body 300.Then, the detecting unit 702 specifies, as the dividingportion P1, a boundary closest to the tip end of thestack body 300 among the detected plurality ofboundaries. In this manner, the boundary B1 between thefirst segment 201 and the second segment 202 is specifiedas the dividing portion P1.

[0036] Next, in an inserting step of step S30, thepushing-out unit 1 and the restricting unit 2 areinserted into the dividing portion P1. Fig. 7 is a sideview of the cutting-out apparatus 100 for explaining theinserting step. Fig. 8 is a top view illustrating thepositional relation between the pushing-out unit 1 andthe restricting unit 2 and the stack body 300 in theinserting step. Fig. 9 is a side view of the cutting-outapparatus 100 for explaining the inserting step. Fig. 10is an enlarged cross-sectional view of the dividingportion of the cutting-out apparatus 100 in the insertingstep.

[0037] In the inserting step, first, as illustrated inFig. 7, the pushing-out unit 1 and the restricting unit 2are moved in the front-back direction so as to match thepositions of the pushing-out unit 1 and the restrictingunit 2 in the front-back direction to the position of thedividing portion P1 in the front-back direction. Morespecifically, the control unit 701 of the control device70 drives the first linear actuator 41 of the movingmechanism 4 based on the detection result of thedetecting unit 702 in the dividing portion detecting stepto move the first moving body 42 in the front-backdirection, so that the pushing-out unit 1 and therestricting unit 2 are disposed immediately above thedividing portion P1. As described above, in the stackbody 300, due to the step (positional deviation betweenthe opposite ends 200a, 200b in the axial direction)formed at the abutment G1 of the segment 200, theposition of the dividing portion P1 in the front-backdirection differs between the first region R1 and thesecond region R2. Therefore, the control unit 701independently controls the first linear actuator 41 ofthe moving mechanism 4A, the first linear actuator 41 ofthe moving mechanism 4B, the first linear actuator 41 ofthe moving mechanism 4C, and the first linear actuator 41of the moving mechanism 4B so as to dispose the firstpushing-out claw 11, the second pushing-out claw 12, thefirst restricting claw 21, and the second restrictingclaw 22 immediately above the P1 that each of themcorresponds. In this manner, as illustrated in Fig. 8,the first pushing-out claw 11 and the first restrictingclaw 21 are disposed immediately above the dividingportion P1 in the first region R1, and the secondpushing-out claw 12 and the second restricting claw 22are disposed immediately above the dividing portion P1 inthe second region R2. In the axial direction of thesegments 200 in the stack body 300, the first pushing-outclaw 11 and the first restricting claw 21 are disposed atthe same position, and the second pushing-out claw 12 andthe second restricting claw 22 are disposed at the sameposition that is on the rear end side of the stack body300 relative to the first pushing-out claw 11 and thefirst restricting claw 21.

[0038] Subsequently, in the inserting step, asillustrated in Fig. 9, the pushing-out unit 1 and therestricting unit 2 are moved downward (in the insertingdirection) so that the pushing-out unit 1 and therestricting unit 2 are inserted into the dividing portionP1. More specifically, the control unit 701 drives thesecond linear actuator 44 of the moving mechanism 4 tolower the second moving body 43 so as to insert thepushing-out unit 1 and the restricting unit 2 into thedividing portion P1. In this manner, as illustrated inFig. 10, the first pushing-out claw 11 and the firstrestricting claw 21 are inserted into the dividingportion P1 in the first region R1, and the secondpushing-out claw 12 and the second restricting claw 22are inserted into the dividing portion P1 in the secondregion R2. In this manner, the pushing-out unit 1 andthe restricting unit 2 are interposed between the firstsegment 201 and the second segment 202. Here, asdescribed above, the coupling member 45 that couples therod 441 of the second linear actuator 44 and the secondmoving body 43 is a floating joint. Therefore, thepushing-out unit 1 and the restricting unit 2 coupled tothe rod 441 via the arm 46 and the coupling member 45 canbe displaced in a very small range relative to the rod441 in the axial direction (that is, the front-backdirection) of the segment 200. In this manner, anydeviation between the positions of the pushing-out unit 1and the restricting unit 2 and of the dividing portion P1in the front-back direction or any deviation angle whenthe pushing-out unit 1 and the restricting unit 2 areinclined relative to the up-down direction is accepted,so that inserting the pushing-out unit 1 and therestricting unit 2 into the dividing portion P1 isfacilitated.

[0039] Next, in a separating step of step S40, thefirst segment 201 is separated from the stack body 300 tobe delivered forward along the retaining unit 10. Fig.11 and Fig. 12 are side views of the cutting-outapparatus 100 for explaining the separating step. Fig.13 is a top view illustrating the positional relationbetween the pushing-out unit 1 and restricting unit 2 andthe stack body 300 in the separating step. Asillustrated in Fig. 11 and Fig. 12, the separating stepis performed in a state of the first rail 10A and thesecond rail 10B contacting with each other, and the firstsegment 201 retained by the first rail 10A is deliveredto a predetermined transferring position of the secondrail 10B. In the separating step, as illustrated in Fig.11, first, the stopper 50 contacting the first segment201 is advanced so as to cause the first segment 201 tobe movable to the transferring position. Next, asillustrated in Fig. 12, only the pushing-out unit 1 isadvanced leaving the restricting unit 2 behind so as toseparate the first segment 201 from the stack body 300.Specifically, the control unit 701 drives the firstlinear actuator 41 of the moving mechanism 4Acorresponding to the first pushing-out claw 11 and thefirst linear actuator 41 of the moving mechanism 4Bcorresponding to the second pushing-out claw 12 toadvance the first moving body 42 of the moving mechanism4A and the first moving body 42 of the moving mechanism4B so as to advance the first pushing-out claw 11 and thesecond pushing-out claw 12. Meanwhile, the control unit701 does not move the first linear actuator 41 of themoving mechanism 4C corresponding to the firstrestricting claw 21 and the first linear actuator 41 ofthe moving mechanism 4D corresponding to the secondrestricting claw 22 so as not to change the positions ofthe first restricting claw 21 and the second restrictingclaw 22. In this manner, as illustrated in Fig. 12, onlythe pushing-out unit 1 is advanced leaving therestricting unit 2 behind. That is, the pushing-out unit1 relatively moves forward relative to the restrictingunit 2 so that the pushing-out unit 1 and the restrictingunit 2 are spaced apart from each other in the front-backdirection. The pushing-out unit 1 advances to push thefirst segment 201 forward. Meanwhile, the restrictingunit 2 contacts the second segment 202 so that theforward movement of the second segment 202 following thefirst segment 201 is restricted. In this manner, thefirst segment 201 and the second segment 202 areseparated from each other. As a result, the firstsegment 201 is separated from the stack body 300 anddelivered forward. The pushing-out unit 1 advances to aposition where the first segment 201 contacts the stopper50. In this manner, the first segment 201 reaches thetransferring position of the second rail 10B.

[0040] Next, in a transferring step of step S50, thefirst segment 201 is transferred to an assembling line.Fig. 14 is a side view of the cutting-out apparatus 100for explaining the transferring step. As illustrated inFig. 13, in the transferring step, the control unit 701drives the rail moving unit 60 to advance the second rail10B so as to separate the first rail 10A and the secondrail 10B from each other. In this manner, the retainingunit 10 is withdrawn from the first segment 201 to enablethe first segment 201 to be taken out. The first segment201 is taken out from the cutting-out apparatus 100 bymeans of a taking-out device (not illustrated) to bedelivered to a line in the following step.

[0041] As described above, through the steps of stepS10 to step S50, the first segment 201 at the tip end iscut out from the stack body 300. The segments 200 arecut out from the stack body 300 one by one by repeatingthe steps of step S10 to step S50.

[0042] [Function and effect]As described above, the cutting-out apparatus 100according to the present embodiment includes theretaining unit 10 extending in a rail form that isinserted into the hollow part H1 of the cylindrical stackbody 300 formed of the plurality of segments 200 stackedin the axial direction so as to retain the stack body300, the cutting-out unit 20 that separates the firstsegment 201 at the tip end from the stack body 300retained by the retaining unit 10 and that delivers thefirst segment 201 along the retaining unit 10, and thedetecting unit 702 that detects the boundary between thesegments 200 that are adjacent to each other in the stackbody 300. Further, after inserting the pushing-out unit1 and the restricting unit 2 into the dividing portion P1that is the boundary between the first segment 201 andthe second segment 202 adjacent to the first segment 201based on the detection result of the detecting unit 702,in a state in which movement of the second segment 202 inthe delivering direction (forward) is restricted by therestricting unit 2, the moving unit 3 moves the pushing-outunit 1 in the delivering direction, so that the firstsegment 201 is separated from the stack body 300, and thefirst segment 201 is delivered along the retaining unit10.

[0043] According to the cutting-out apparatus 100 assuch, by detecting the boundary between the segments 200that are adjacent to each other by the detecting unit702, even when a step is formed at the abutment G1 of thesegment 200, the pushing-out unit 1 and the restrictingunit 2 can be inserted into the dividing portion P1.Further, after inserting the pushing-out unit 1 and therestricting unit 2 into the dividing portion P1, in astate in which movement of the second segment 202 in thedelivering direction is restricted by the restrictingunit 2, the first segment 201 is moved in the deliveringdirection by the pushing-out unit 1, so that the firstsegment 201 and the second segment 202 can be surelyseparated from each other, and the movement of the secondsegment 202 in the delivering direction following thefirst segment 201 can be restricted. In this manner, thesegments 200 can be surely cut out from the stack body300 one by one. As a result, defective cutting out canbe reduced. In particular, in cutting out the pistonring with a narrow width (thickness in the axialdirection) like the segment as well, the piston rings canbe surely cut out one by one.

[0044] Further, in the cutting-out apparatus 100according to the present embodiment, the retaining unit10 retains the plurality of segments 200 such that theabutments G1 of the plurality of segments 200 are alignedso as to form the slit S1 extending in the axialdirection in the stack body 300. Furthermore, thepushing-out unit 1 and the restricting unit 2 areinserted into the dividing portion P1 in the directionfrom the slit S1 toward the hollow part H1 of the stackbody. Moreover, the stack body 300 is sectioned into thefirst region R1 and the second region R2 by the slit S1as seen in the direction in which the pushing-out unit 1and the restricting unit 2 are inserted into the dividingportion P1. In addition, the pushing-out unit 1 includesthe first pushing-out claw 11 inserted into the dividingportion P1 in the first region R1 and the second pushing-outclaw 12 inserted into the dividing portion P1 in thesecond region R2, and the restricting unit 2 includes thefirst restricting claw 21 inserted into the dividingportion P1 in the first region R1 and the secondrestricting claw 22 inserted into the dividing portion P1in the second region R2.

[0045] That is, the cutting-out apparatus 100 isconfigured such that the pushing-out unit 1 and therestricting unit 2 are inserted into the dividing portionP1 in each of the first region R1 and the second regionR2 that are the regions sandwiching the slit S1. Whenthe positions of the opposite ends 200a, 200b of thepiston ring at the abutment G1 are deviated from eachother in the axial direction, the adjacent piston ringsin the stack body are more likely to be entangled nearthe abutments. Meanwhile, in the cutting-out apparatus100, the pushing-out unit 1 and the restricting unit 2are inserted into both sides of the abutment G1 (slit S1)to perform operation of separating the first segment 201and the second segment 202 on both sides of the abutmentG1, so that the first segment 201 and the second segment202 can be surely separated from each other. In thismanner, the segments 200 can be more surely cut out fromthe stack body 300 one by one.

[0046] In the stack body, in some cases, the positionof the dividing portion in the axial direction (that is,the delivering direction) of the piston ring differsbetween the first region and the second region due to thedeformation at the time of forming the piston ring.Meanwhile, in the present embodiment, in inserting thepushing-out unit 1 and the restricting unit 2 into thedividing portion, in the axial direction of the segments200 in the stack body 300, the first pushing-out claw 11and the first restricting claw 21 are disposed at thesame position, and the second pushing-out claw 12 and thesecond restricting claw 22 are disposed at the sameposition that is deviated from the first pushing-out claw11 and the first restricting claw 21. In this manner,the pushing-out unit 1 and the restricting unit 2 can beinserted into the dividing portion P1 in each of thefirst region R1 and the second region R2.

[0047] Further, in the present embodiment, thedetecting unit 702 acquires the images of the firstregion R1 and the second region R2 and detects thedividing portion P1 in each of the first region R1 andthe second region R2 based on the images acquired. Asdescribed above, there are some cases in which theposition of the dividing portion in the axial directionof the piston ring differs between the first region andthe second region, but in the cutting-out apparatus 100according to the present embodiment, the dividing portionP1 in each of the first region R1 and the second regionR2 is detected, so that the pushing-out unit 1 and therestricting unit 2 can be surely inserted into thedividing portion P1 in each of the first region R1 andthe second region R2.

[0048] Furthermore, the moving unit 3 includes the rod441 of the second linear actuator 44 that moves in thedirection in which the pushing-out unit 1 and therestricting unit 2 are inserted into the dividing portionP1, and the pushing-out unit 1 and the restricting unit 2are coupled to the rod 441 via the coupling member 45that is a floating joint such that the pushing-out unit 1and the restricting unit 2 can be displaced relative tothe rod 441 in the axial direction of the segment 200 inthe stack body 300. According to this, when insertingthe pushing-out unit 1 and the restricting unit 2 intothe dividing portion P1, any deviation between thepositions of the pushing-out unit 1 and the restrictingunit 2 and of the dividing portion P1 in the axialdirection of the segment 200 or any deviation angle whenthe pushing-out unit 1 and the restricting unit 2 areinclined relative to the inserting direction can beaccepted, so that inserting the pushing-out unit 1 andthe restricting unit 2 into the dividing portion P1 canbe facilitated. In this manner, the pushing-out unit 1and the restricting unit 2 can be surely inserted intothe dividing portion P1. Note that the rod 441 is anexample of an "inserting unit" according to the presentinvention.

[0049] <Others>The preferable embodiment of the present inventionhas been described above, but various changes,modifications, combinations, and the like are availablefor the cutting-out apparatus according to theembodiment. For example, in the above-describedembodiment, the retaining unit is horizontally provided,but the present invention is not limited thereto.Reference Signs List

[0050] 100: cutting-out apparatus10: retaining unit20: cutting-out unit30: camera1: pushing-out unit11: first pushing-out claw12: second pushing-out claw2: restricting unit21: first restricting claw22: second restricting claw3: moving unit4: moving mechanism

Claims

1. A cutting-out apparatus for a piston ring comprising: a retaining unit extending in a rail form that is inserted into a hollow part of a cylindrical stack body formed of a plurality of piston rings stacked in an axial direction so as to retain the stack body; a cutting-out unit that separates a piston ring at a tip end of the stack body from the stack body retained by the retaining unit and that delivers the piston ring at the tip end along the retaining unit; and a detecting unit that detects a boundary between the piston rings that are adjacent to each other in the stack body, wherein the cutting-out unit includes a pushing-out unit, a restricting unit, and a moving unit that moves the pushing-out unit and the restricting unit, and after inserting the pushing-out unit and the restricting unit into a dividing portion that is a boundary between the piston ring at the tip end and a piston ring that is adjacent to the piston ring at the tip end in the stack body based on a detection result of the detecting unit, in a state in which movement of the piston ring that is adjacent to the piston ring at the tip end in a delivering direction in which the piston ring at the tip end is delivered is restricted by the restricting unit, the moving unit moves the pushing-out unit in the delivering direction, so that the piston ring at the tip end is separated from the stack body, and the piston ring at the tip end is delivered along the retaining unit.

2. The cutting-out apparatus for a piston ring according to claim 1, wherein the retaining unit retains the stack body such that abutments of a plurality of piston rings are aligned so as to form a slit in the stack body extending in the axial direction of the stack body, the pushing-out unit and the restricting unit are inserted into the dividing portion in a direction from the slit toward the hollow part of the stack body, the stack body is sectioned into a first region and a second region by the slit as seen in a direction in which the pushing-out unit and the restricting unit are inserted into the dividing portion, the pushing-out unit includes a first pushing-out claw inserted into the dividing portion in the first region and a second pushing-out claw inserted into the dividing portion in the second region, and the restricting unit includes a first restricting claw inserted into the dividing portion in the first region and a second restricting claw inserted into the dividing portion in the second region.

3. The cutting-out apparatus for a piston ring according to claim 2, wherein the detecting unit acquires images of the first region and the second region and detects the dividing portion in each of the first region and the second region based on the images acquired.

4. The cutting-out apparatus for a piston ring according to any one of claims 1 to 3, wherein the moving unit includes an insertion member that moves in a direction in which the pushing-out unit and the restricting unit are inserted into the dividing portion of the stack body, and the pushing-out unit and the restricting unit are coupled to the insertion member such that the pushing-out unit and the restricting unit can be displaced relative to the insertion member in the axial direction of the piston rings in the stack body.