JPH11123619A - Device for assembling piston ring - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide a simple inexpensive device for assembling a piston ring which can stabilize the position where the diameter of the piston ring is expanded to automatically surely effectively fit the piston ring in a piston ring groove. SOLUTION: A highly rigid claw 2 having a stopper 3 is fixed to the finger 8 of a commercially available air chuck 4 and a piston ring 13 is fitted in the claw 2. A protruding sleeve 6 is moved until the stopper 3 of the claw 2 abuts on the inner surface of a sleeve 5 to put the bottom end 6a of the protruding sleeve 6 into contact with the piston ring, whereby the piston ring 13 is released from the claw 2 and fitted in a piston groove by the contracting force thereof. The piston ring 13 is positioned and mounted to a correct position with no variance because of the stabilization of the position where the diameter of the piston ring 13 is expanded and the high rigidity of the claw 2.

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to an apparatus for automatically assembling a piston ring into a piston groove, and more particularly, to stabilizing the expanded diameter of the piston ring and using a commercially available air chuck. The present invention relates to a piston ring assembling device having a simple structure.

[0002]

2. Description of the Related Art Various types of assembling apparatuses for automatically mounting a piston ring in a piston groove have been employed. Japanese Patent Publication No. Hei 6-98543 shows one example. In this "piston ring assembling apparatus", a piston ring is fitted around the outer periphery of the collet, and the collet is moved in the diameter increasing direction by the operation of an operating body engaging with the collet to expand the piston ring. A structure is disclosed in which the ring extrusion is moved to align the piston ring with the piston groove, and the piston ring is automatically mounted in the piston groove by the diameter reduction force of the piston ring.

[0003]

FIGS. 6 to 8 schematically show the main parts of the above-mentioned known technique. FIG. 6 shows a state in which the collet 16 in which the piston ring 13 is fitted on the outer periphery is moved in the radial direction of the piston ring 13. In this state, the ring push-out 17 is disposed at a position facing the surface of the piston ring 13.
FIG. 7 shows that the ring pusher 17 is moved in the axial direction from the state of FIG. 6, the piston ring 13 is released from the collet 16, and the piston groove 14 of the piston 15 and the piston ring 1 are moved.
3 shows a state where alignment with No. 3 is performed. In this state, the piston ring 13 is in a free state.
3 is automatically mounted in the piston groove 14 by the diameter reducing force.

[0004] When the bending rigidity of the collet 16 is high, the mounting of the piston ring 13 works well even with this structure.
Generally, the collet 16 is made of a material having a low rigidity. In particular, the portion A shown in the drawing has a low rigidity and is easily elastically deformed. On the other hand, the diameter reducing force of the expanded piston ring 13 is considerably large.
As shown in FIG. 8, there is a problem that the vicinity of the portion A of the collet 16 is bent by the diameter reducing force, and the diameter of the piston ring 13 is not expanded to a predetermined diameter expanding position indicated by a two-dot chain line. Further, there is a problem in that the diameter of the piston ring 13 is varied, the engagement between the ring push-out 17 and the piston ring 13 is not stabilized, and the piston ring 13 is not smoothly fitted into the piston groove 14. . In this case, there is a solution for making the collet 16 highly rigid. However, there is a problem that the expanding force of the collet by the operating body becomes large and the entire mounting becomes large. Further, the exchange of the collet is usually not easy and is expensive, so that the cost of the apparatus is increased.

An object of the present invention is to solve the above problems, and an object of the present invention is to provide a piston ring assembling apparatus which can stabilize the expanded position of the piston ring and can be implemented at low cost.

[0006]

SUMMARY OF THE INVENTION In order to achieve the above object, the present invention provides an air chuck fixed to a predetermined position of a device for expanding and holding a piston ring, and a sleeve surrounding the air chuck. An extruding sleeve that is slidably supported along the axial direction on the outer periphery of the sleeve and that pushes out the piston ring. The finger of the air chuck has a relatively high rigidity claw that holds the piston ring on the outer periphery. Are detachably fixed, and a piston ring assembling device is provided between the claw side and the sleeve, which is provided with a stopper for limiting the amount of movement of the finger in the radial direction. Furthermore, the nail is fixed to the finger by a fastener. Further, the stopper is fixed to the claw.

The pawl fixed to the finger of the air chuck and fitted with a piston ring on the outer periphery is operated by the normal diameter expanding operation of the air chuck to expand the diameter of the piston ring. Since the claw is formed with high rigidity, the claw hardly deforms due to the contracting force at the time of expanding the diameter of the piston ring. on the other hand,
A stopper is provided on the pawl in order to stabilize the position of the enlarged diameter of the pawl.
Thus, the finger may be moved in the radial direction until the stopper comes into contact with the sleeve. As described above, the diameter expansion position of the piston ring is stabilized. Therefore, the engagement of the extrusion sleeve with the piston ring whose diameter has been increased makes it possible to stably and reliably mount the piston ring in the piston groove.

[0008]

BRIEF DESCRIPTION OF THE DRAWINGS FIG. 1 is a perspective view showing a piston ring assembling apparatus according to an embodiment of the present invention; First,
The overall structure of the piston ring assembling apparatus of the present invention will be described with reference to FIG. The piston ring assembling device 1 includes a stopper 3
A commercially available air chuck 4 holding the claw 2 having a groove, a sleeve 5 surrounding the air chuck 4, and an extruding sleeve 6 slidably supported on the outer periphery of the sleeve 5 along the axial direction. The air chuck 4 is fixed to the stationary side 7 of the apparatus, and has a structure in which the finger 8 can be freely expanded and contracted in the radial direction (the direction of arrow A) by air pressure by an internal mechanism. The sleeve 5 is also fixed to the stationary side 7, and the pushing sleeve 6 is also configured to move in the axial direction (the direction of arrow B) by a moving mechanism (not shown) provided on the stationary side.

As shown in FIGS. 1 and 2, the air chuck 4 includes a main body 9 and finger mounting portions 10 formed at a plurality of locations (six in the drawing) along the periphery of the main body.
In the case of the piston ring assembling device 1 of the present invention, three of the six finger mounting portions 10 are used, and three existing fingers 8 are provided at those portions. Note that the three fingers 8 are arranged at positions where the circumference is equally divided into three. The finger 8 is provided with a screw hole 11.

As shown in FIGS. 1 and 2, the claw 2 is made of a relatively rigid block having an L-shaped cross section.
One side 2a has two bolts 12, 12 as fasteners.
Is fixed to the finger 8 by being screwed into the screw holes 11, 11. The one side 2a is integrally provided with a protruding stopper 3. The other side 2b of the claw 2 is arranged along the axial direction, and a piston ring 13 is inserted around the outer periphery. Note that the stopper 3 is disposed at a position where the stopper 3 can contact the inner surface of the sleeve 5.

The extrusion sleeve 6 is slidably supported on the outer periphery of the sleeve 5 along the axial direction as described above. The lower end 6a of the pushing sleeve 6 does not face the piston ring 13 inserted into the other side 2b of the claw 2 in a state where the finger 8 of the air chuck 4 does not move in the radially expanding direction. Are arranged so as to face the upper surface of the piston ring 13 when moved in the radial direction (outward).

Next, the piston ring assembling apparatus 1 of the present invention.
The operation of the automatic mounting of the piston ring 13 will be described. 1 and 3 show an initial state before mounting the piston ring 13 in which the air chuck 4 does not operate. That is, the finger 8 is at the position where the diameter is reduced, and the piston ring 13 is fitted around the outer circumference of the claw 2 fixed to the finger. In this state, the stopper 3 is located at a position away from the inner surface of the sleeve 5, and the lower end 6 a of the pushing sleeve 6 is located at a position not facing the piston ring 13.

When the air chuck 4 is actuated by an air supply device (not shown), the finger 8 moves in the diameter increasing direction, and the claw 2 moves in the same direction. For this reason, the diameter of the piston ring 13 is expanded, and the diameter reducing force acts on the claw 2. However, since the claw 2 is formed with high rigidity, it hardly deforms. That is, the diameter of the piston ring 13 expands by substantially the same amount as the movement amount of the finger 8.

Further, when the finger 8 moves in the diameter expanding direction, the stopper 3 hits the inner surface of the sleeve 5 as shown in FIG. This position corresponds to a predetermined movement position of the claw 2 and the piston ring 13. In other words, the finger 8 only needs to be moved to a position where the stopper 3 comes into contact with the inner surface of the sleeve 5, and the movement amount can be easily adjusted. As shown in FIG. 4, with the stopper 3 in contact with the inner surface of the sleeve 5, the piston ring 13 reaches a position facing the lower end 6 a of the pushing sleeve 6. Further, as described above, since the pawl 2 has high rigidity, the position of the piston ring 13 in this state is not changed, and does not vary as in the related art.

Next, when the pushing sleeve 6 is lowered in the axial direction, the piston ring 13 is pushed downward as shown in FIG. 5 and reaches the position shown by the two-dot chain line in the figure, which is disengaged from the pawl 2. This position is at a position opposite to the piston groove 14 of the piston 15, and the piston ring 13 in the free state is reduced in diameter by its diameter reducing force, automatically fits in the piston groove 14, and At a predetermined position.

The piston groove 1 of one piston ring 13
When the mounting into the inside 4 is completed, the pushing sleeve 6 is moved along the axial direction to bring it into the state shown in FIGS. 1 and 3 and the like, and the piston ring 13 to be mounted next is inserted into the claw 2. Hereinafter, by repeating the same operation, the attachment of the piston ring 13 to the piston 15 is completed.

As apparent from the above description, in the piston ring assembling apparatus 1 of the present invention, the piston ring 13 is moved only by moving the finger 8 of the air chuck 4 until the stopper 3 of the pawl 2 comes into contact with the sleeve 5. Are set at predetermined mounting positions without variation, and the piston ring 13
Can be mounted on the piston groove 14 very easily, in a short time, and accurately.

In the above description, the shape of the claw 2 is L-shaped as shown in FIG.
Any other shape may be used as long as it can be fixed to the finger 8. In addition, the stopper 3 is formed integrally with the claw 2, but may be a member to which a separate product is fixed. Further, the stopper 3 may be provided on the sleeve 5 side.

[0019]

【The invention's effect】

1) According to the piston ring assembling apparatus of the first aspect of the present invention, a highly rigid claw is fixed to the finger of the air chuck, and the claw is moved to a predetermined position using a stopper. By the operation, the piston ring is positioned without variation, and the piston ring is stably mounted in the piston groove. 2) According to the piston ring assembling device of the third aspect of the present invention, the structure can be simplified by providing the stopper with the pawl.

[Brief description of the drawings]

FIG. 1 is an axial sectional view showing the entire structure of a piston ring assembling apparatus of the present invention.

FIG. 2 is a perspective view for explaining a structure of a claw according to the present invention and a state where the claw is fixed to a finger of a commercially available air chuck.

FIG. 3 is a partial axial sectional view showing a set state before the piston ring is inserted by the piston ring assembling apparatus of the present invention.

FIG. 4 is a partial axial sectional view showing a state in which an air chuck is operated, a piston ring is expanded to an expanded position, and is engaged with an extrusion sleeve.

FIG. 5 is a partial axial sectional view showing a state in which a piston ring is mounted in a piston groove by the piston ring assembling apparatus of the present invention.

FIG. 6 is a schematic diagram showing an expanded state of a piston ring which is not deformed by a conventional piston ring assembling device.

FIG. 7 is a schematic view showing a mounted state in which a piston ring is not deformed by a conventional piston ring assembling apparatus.

FIG. 8 is a schematic view for explaining a practical problem in a conventional piston ring assembling apparatus.

[Explanation of symbols]

 DESCRIPTION OF SYMBOLS 1 Assembling apparatus of piston ring 2 Claw 2a One side 2b Other side 3 Stopper 4 Air chuck 5 Sleeve 6 Extrusion sleeve 6a Lower end 7 Non-moving side 8 Finger 9 Main body 10 Finger mounting part 11 Screw hole 12 Bolt 13 Piston ring 14 Piston groove 15 Piston

Claims (3)

[Claims] An air chuck fixed to a predetermined position of an apparatus for expanding and holding a piston ring, a sleeve surrounding the air chuck, and slidably supported on an outer periphery of the sleeve along an axial direction. An extrusion sleeve that pushes out the piston ring, a relatively high-rigid pawl that holds the piston ring on the outer periphery is detachably fixed to the finger of the air chuck, and between the pawl side and the sleeve. Is a piston ring assembling device, wherein a stopper is provided to limit the amount of movement of the finger in the radial direction. 2. A piston ring assembling apparatus according to claim 1, wherein said pawl is fixed to said finger by a fastener. 3. The piston ring assembling apparatus according to claim 1, wherein the stopper is fixed to the pawl.