JPH0451293B2 - - Google Patents

Description

DETAILED DESCRIPTION OF THE INVENTION (Field of Industrial Application) The present invention relates to a method of assembling a piston ring to a piston.

(Problems to be solved by the prior art and the invention) Pistons used in engines, compressors, etc. are used to maintain airtightness within the cylinder and to scrape off lubricating oil, etc. adhering to the inner surface of the cylinder. Multiple piston rings are installed. A portion of the piston ring is cut out so that its diameter can be elastically expanded and contracted, and the piston ring is fitted into a ring groove in the head portion of the piston at a predetermined interval. The multiple piston rings attached to one piston each have different functions and functions, and therefore have slightly different shapes.Then, these rings are placed in the ring grooves provided at predetermined positions on the piston, and the positions of the notches of each piston ring are different from each other. It is necessary to shift and install it without making a mistake.

Another problem is how to quickly and easily attach a plurality of piston rings to a plurality of pistons.

The present invention has been made in view of the above points, and its object is to provide a method for assembling a piston ring to a piston, which allows a predetermined piston ring to be quickly, easily, and reliably installed in a ring groove of a piston. is to provide.

(Means for solving the problem) A means for solving the above problem is that in a piston ring assembly method in which a piston ring is assembled to a piston having a plurality of ring grooves, the outer circumferential surface expands in diameter downward. After fitting and holding a predetermined piston ring whose cut holes are offset from each other into a conical holding cup, the head of the piston is inserted into this holding cup, and the lower end surface of the holding cup is aligned with the piston. The lowermost ring is positioned on the upper surface of the groove, and then the lowermost piston ring is lowered from the retaining cup while pushing down the piston ring along the retaining cup to attach it to the piston. By lowering or raising the holding cup, the piston ring is lowered from the holding cup while sequentially aligning the lower end surface of the holding cup with the upper surface of the ring groove of the piston, and the piston ring is attached to the piston.

(Function) According to the above means, while positioning the holding cup in the ring groove of the piston, the piston ring of the holding cup can be lowered and the piston ring can be assembled to the piston. can be installed quickly, easily, and reliably.

(Embodiment) Next, a preferred embodiment of the present invention will be described in detail with reference to the attached FIGS. 1 to 10.

Devices for assembling the piston ring l to the piston P include a piston ring stocker 1, a piston ring supply device 2, a piston ring delivery device 3, a piston ring assembling device 4, etc. The examples mainly show the piston ring assembling device 4, but in order to make the explanation easier to understand, all the devices will be described below.

Here, the piston ring stocker 1 stacks piston rings l,... with different types and notch orientations, in respective magazines 11,... on a table 10, and the piston ring supply device 2 stacks the piston rings l,... with different types and orientations of the notches. A set of piston rings l, . The piston rings l, .
A holding cup U that holds a set of piston rings l, .

First, the positional relationship of the respective devices 1, 2, 3, and 4 will be explained with reference to FIG.
It is positioned on a conveyor C disposed in the vertical direction of the paper, and a piston ring delivery device 3 is disposed on the left side of the conveyor C, and a piston ring stocker 1 is disposed further on the left side. ing.
A piston ring supply device 2 is disposed above the piston ring stocker 1, and
A piston ring assembly device 4 is disposed above and to the left of the conveyor C.

For convenience of explanation, the direction in which the conveyor C is disposed is defined as the front-rear direction of the device, and the direction that crosses the conveyor C orthogonal thereto is defined as the left-right direction of the device.

Next, the piston ring stocker 1 and piston ring supply device 2 will be explained with reference to FIGS. 1 to 4.

The piston ring stocker 1 includes a table 10 that can be rotated in a fixed direction around its center on a base 6, and a magazine 1 that guides and stacks various piston rings l,... on the table 10.
1, etc., and the magazine 11 is the second magazine.
As shown in the figure, nine magazines are arranged on a table 10, three of each in a straight line to form an equilateral triangle, and by rotating the table 10 by 120 degrees, predetermined three magazines 11, . . . are positioned forward and backward along the conveyor C below the piston ring supply device 2.

In each magazine 11, ... below the piston ring supply device 2, an oil ring l is placed from the bottom in FIG.
Three types of piston rings 1, ie, a first compression ring 1, a first compression ring 12, and a second compression ring 13, are piled up, and these form a set of piston rings 1 necessary for one piston P. Note that the first and second
The compression rings l2 and l3 have the same shape, but as shown in FIG.
1 and l3-1 are arranged in different directions so that they are not arranged in the same direction. Each magazine 11 disposed below the piston ring supply device 2,
The piston rings 11, 12, 13, . Furthermore, the piston rings l1, l2, l3, below the piston ring supply device 2,
When ... runs out, the table 10 rotates and the piston rings l1, l2, l in the next magazine 11, ... are removed.
3, . . . will be arranged in the same manner as described above.

The piston ring supply device 2 is supported on a base 6 and is provided on a gate-shaped support 7 that is disposed to straddle a part of the table 10 of the piston ring stocker 1. , are supported in three rows in front and back on the support stand 7, each having a pair of guide rods 21, 21, and the right part of the conveyor C side protrudes from the support stand 7 to the right side of the conveyor C side. The first, second and third guide stands 20 of the stand
A, 20B, 20C, and are fitted and supported by the guide rods 21, 21, . . . of the guide stands 20A, .
The guide stand 2 is placed along the guide rods 21, 21,...
Three movable tables 22, . Guide platform 20A, conveyor C of...
Guide rods 21, 21, . . . are provided at the side ends.
It consists of three pedestals 31, . . . , which are fitted into and slidably supported, and which are elastically biased toward the movable table 22, . . . by spring members 32, 32, .

The three first, second, and third guide stands 20A,...
As shown in FIG. 2, the three magazines 11, . 2. Below the third guide tables 20B and 20C are the first and
Second compression rings l2, l3, . . . are stacked. and the piston rings l1, l2, l
Each guide stand 20A above 3,... and the support stand 7
As shown in FIG. 3, the vertical through hole has a guide member 25 extending downward along its inner peripheral edge,...
are attached, and piston ring insertion holes 26, . Further, upper and lower through-holes 27 are also provided in the right part of each guide stand 20 that protrudes from the support stand 7, and the left side of the through-hole 27 has a circular shape for dropping a predetermined piston ring l downward. This is a piston ring supply hole 27a.

As shown in FIG. 3, the movable table 22 has a cutout plate 28 at its lower part that slides in close contact with the guide table 20, and a guide for the guide table 20 is provided on the lower right surface of the cutout plate 28. A cutting groove 29 is provided at the position of the member 25 to take out the piston rings 1 one by one. The cutout groove 29 has a depth equal to the thickness of the piston ring l, and its right end side extends outward with a width slightly larger than the diameter of the piston ring l, but its left end side has the shape of the piston ring l. A stepped portion 29a having a semicircular arc shape is formed.
Further, the left portion of the cutout plate 28 serves as a holding portion 28a that extends long to the left by passing through the hole 30 of the guide rod support portion 20a on the left side of the guide stand 20.

The cradle 31 is disposed on the through hole 27 of the guide pedestal 20, and the spring member 3 is mounted between the right end thereof and the right guide rod support part 20b of the guide part 20.
2, 32 to always move the right moving platform 2 to a predetermined position.
The movable base 22 is moved under pressure from the 2nd side, and also slides in close contact with the upper surface of the guide base 20 at the bottom thereof.
It has a receiving member 33 that protrudes to the side. The protrusion 33a of the receiving member 33 has approximately the same thickness as the piston ring 1, and its left end surface forms a guide surface 34 recessed toward the center, as shown in FIG. The protruding portion 33a of the pedestal 31 is pushed by the spring members 32, 32, and is always positioned in a state where approximately two-thirds of the piston ring supply hole 27a of the guide pedestal 20 is blocked, as shown in FIG. has been done.

As shown in FIG. 3, the lateral movement cylinder 24 is attached to the guide rod support portion 20a of the second guide stand 20B in the center, and the rod 24a
The tip end is fixed to the upper part of the second guide stand 20B via a connecting member 23.

Here, the operation of the piston ring supply device 2 will be explained below. First, the oil rings l1, . It is pressed elastically into the groove 29. Next, the rod 24 of the lateral movement cylinder 24
a extends to the right side of the conveyor C, and the moving table 22 moves to the receiving table 31 side, but at this time, the cutting groove 2
The oil ring l1 in the cradle 31 is also pushed by its stepped portion 29a and slides on the guide table 20A, and the oil ring l1 is pushed by the step 29a thereof and slides on the guide table 20A.
until it comes into contact with the guide surface 34 of. Furthermore, as the moving table 22 moves to the right, this receiving table 31 is also pushed toward the conveyor C side through the oil ring l1 against the elastic force of the spring members 32, 32. When located at the center of the piston ring supply hole 27a of the guide stand 20A, its movement is stopped.

Next, the holding cup U of the piston ring delivery device 3 positioned below the piston ring supply hole 27a rises to a predetermined position inside the piston ring supply hole 27a as shown in FIG. The engagement rod 41b is the fourth
As shown in the figure, the oil ring l1 and the pedestal 31
When the receiving table 31 is inserted into the gap S between the receiving member protrusion 33a and the receiving member 31 further moves toward the conveyor C side,
This oil ring l1 falls downward while remaining in a horizontal state, and is fitted into and supported by the holding cup U of the piston ring delivery device 3.

Here, as the left-right motion cylinder 24 moves, the movable base 2 on the other second and third guide bases 20B and 20C
Although piston rings 2 and 22 also move, the above-mentioned action does not occur because these piston rings l2 and l3 are not pushed up. Also, the oil ring l
1 moves close to the position of the pedestal 31, the large number of oil rings l1, .

Next, the first compression rings l2, .
It is moved onto the piston ring supply hole 27a of the guide stand 20B and dropped downward. In this case, the holding cup U that holds the oil ring l1 has moved below the piston ring supply hole 27a of the second guide stand 20B, so the first compression ring l2 is stacked on top of the oil ring l1. becomes. Similarly, the second compression ring l3 will be supported on the first compression ring l2 of the holding cup U.

And this holding cup U has one piston P.
A set of piston rings l1, l installed on
2, l3 are the notches l1-1, l2-1, l3
-In order to assemble from the bottom so that the positions of 1 do not overlap (from the bottom, oil ring l1, first and second compression rings l)
2, l3).

Next, the piston ring delivery device 3 is mainly
This will be explained with reference to FIGS. 2, 2, and 10.
The piston ring delivery device 3 includes first, second, and third guide stands 20 of the piston ring supply device 2.
Each piston ring supply hole 2 of A, 20B, 20C
7a, . . . Move the retaining cup U for holding the piston ring downward, and the oil ring l1, the first and second compression rings l2, held by this retaining cup U.
13 together with this holding cup U to the next piston ring assembling device 4.

Here, to explain the holding cup U with reference to a in FIG. 10, the table U has an upper outer surface that is a conical surface U1 that expands in diameter downward, and a lower outer surface that is a cylindrical surface U2 that has the same diameter. There is. Further, in the center of the upper surface, there is provided a support protrusion Ua and an engagement part Ub having a diameter slightly larger than the support protrusion Ua and having a positioning recess Ub-1 at the upper part, and a lower surface thereof having a diameter slightly larger than that of the support protrusion Ua. Downward recess U3 for inserting the diameter piston P
A support hole U4 for positioning and pushing up the holding cup U is provided further above the recess U3. Then, the holding cup U falls horizontally from above and this holding cup U
The piston ring L, which is fitted and supported by the piston ring, expands in diameter slightly due to its own weight, and is supported and held at a predetermined position on the conical surface U1 of the holding cup U, as shown in FIG. 10a.

Now, as shown in FIG. 1, the piston ring delivery device 3 includes a horizontal support plate 40 having support portions 41, 41 for the holding cups U, U at both left and right ends on the piston ring supply device 2 side and the conveyor C side; A vertical rotating shaft 45 whose upper end is fixed to the center part of the support plate 40 and a lower gear 46 fixed thereto;
The upper and lower parts of 5 are rotatably supported by the upright member 47a, and are fitted and supported by front and rear guide bars 48, 48 provided on the support member 6a of the base 6, so that they can slide back and forth. a longitudinally movable table 47, a longitudinally movable cylinder 49 that is supported by the support member 6a and moves the longitudinally movable table 47 back and forth along the guide bars 48, 48, and a rising member 47a of the longitudinally movable table 47. A rotating cylinder 50 that moves a rack 51 supported and slidably supported by the upright member 47a back and forth and rotates the rotating shaft 45 via a gear 46, and a supporting portion 41 of the supporting plate 40. ,4
1 and vertically movable rods 52, 52 which are provided in the center of the piston ring supply device 2 and can freely slide up and down with respect to the support portion 41, and below the piston ring supply holes 27a, . is supported by the support member 6a via brackets 6b, . . .
Similarly, it consists of three push-up cylinders 54, etc., which push up the vertical movement rods 52, which are positioned below the piston ring supply holes 27a,...

The support part 41 of the support plate 40 has a receiving plate 41a that supports the lower surface of the holding cup U of the piston ring l.
and an upwardly directed engagement rod 41b for dropping the piston ring l from the holding cup supply device 2;
A guide portion 41c that slidably guides the vertically movable rod 52 and supports a spring member 53 between the vertically movable rod 52 and the lower end thereof is provided. It is positioned in the left-right direction so that the axis of the right side support part 41 and the axis of the piston ring supply holes 27a of each guide stand 20, ... of the piston ring supply device 2 coincide with each other. Further, the vertically movable rod 52 is supported by being elastically biased downward by a spring member 53, and the support plate 40 of the vertically movable rod 53
A tip portion 52a that protrudes upward by the support portion 41 of
is always inserted into the support hole U4 of the holding cup U to such an extent that the holding cup U is not pushed up, and the holding cup U is positioned on the guide portion 41 of the support plate 40.

The longitudinal movement cylinder 49 moves the support plate 40 back and forth via the longitudinal movement table 47 and the rotating shaft 45, and moves the holding cup U on the right support part 41 of the support plate 40 to each guide of the piston ring supply device 2. It is positioned directly below the piston ring supply holes 27a, ... of the stands 20, ..., respectively, and the push-up cylinder 5
4, . . . use the rods 54a, . Push up against the elastic force, vertically moving rod 5
2, the upper part of the holding cup U on the support part 41 is inserted into the piston ring supply hole 27a of the piston ring supply device 2 as shown in FIG.
1b, the cradle 31 of the piston ring supply device 2
Engage with the protrusion 33a, move the pedestal 31 slightly to the right side of the conveyor C, and drop the piston ring l sandwiched between the pedestal 31 and the moving table 22 into the holding cup U below. It is to be held in place.

Further, the rotation cylinder 50 rotates the support plate 40 by 180 degrees.
Rotate horizontally and remove a set of piston rings l,...
The positions of the left-hand holding cup U holding the holder and the empty right-hand holding cup U are interchanged from side to side.

Here, the operation of this piston ring delivery device 3 will be explained below. First, the receiving plate 41 of the left support part 41 on the side of the piston ring supply device 2 of the support plate 40
The first holding cup U is positioned on top a, and the support plate 40 is moved back and forth by the forward and backward motion cylinder 49, so that the first holding cup U is placed on the first guide stand 20A of the piston ring supplying device 2. It is positioned below the hole 27a. Note that this position of the support plate 40 is referred to as the original position A. Next, the first guide platform 20A
Rod 5 of the first push-up cylinder 54 located below
4a rises, the left support part 41 of the support plate 40
Push up the vertically movable rod 52 inserted into the piston ring supply hole 27 to insert the upper part of the first holding cup U into the
an oil ring l1 that is positioned within the piston ring supply hole 27a and falls horizontally from the piston ring supply hole 27a;
is held in the first holding cup U.

Then the rod 54 of the first push-up cylinder 54
a is lowered and the first holding cup U holding the oil ring l1 is again placed on the receiving plate 41a of the support plate 40, and the first holding cup U is moved to the first holding cup U of the piston ring supplying device 2 by the longitudinal movement cylinder 49. The first holding cup U is positioned below the piston ring supply hole 27a of the second guide stand 20B, and the first holding cup U is raised by the second push-up cylinder 54 located below the second guide stand 20B.
The first compression ring l2 is held on the oil ring l1. At the same time, this first holding cup U is positioned in the piston ring supply hole 27a of the third guide stand 20C, and the second compression ring l3 is held on the first compression ring l2 of this first holding cup U.

As described above, when the oil ring l1, the first compression ring l2, and the second compression ring l2 are held in the lower order by the first holding cup U as shown by a in FIG. The piston ring supply device 2 is retreated to its original position A below the first guide stand 20A. After that, when an empty second holding cup U from the piston ring assembly device 4 (to be described later) is positioned and placed on the receiving plate 41a of the right support part 41 of the support plate 40, the support plate 40 is placed on the rotating cylinder 50. horizontally rotates 180 degrees via the rack 51, gear 46, and rotating shaft 45, and the first holding cup U is positioned on the conveyor C side and the second holding cup U is positioned below the first guide stand 20A of the piston ring supply device 2. It will be done.

In this state, the first holding cup U is carried by the piston ring assembly device 4 toward the piston P on the conveyor C, and the oil ring l1 and the first and second compression rings l2 and l3 are assembled into the piston P. During this time, the next piston ring 1 is similarly supplied to the second holding cup U on the support base 40.

Next, the piston ring assembly device 4 will be explained with reference to FIGS. 5 to 10. The piston ring assembly device 4 places the empty holding cup U after the piston ring l has been assembled on the support portion 41 on the conveyor C side of the support plate 40 located at the original position A of the piston ring delivery device 3. At the same time, in this original position A, the holding cup U having the piston rings L, . This device moves toward the piston P and assembles the piston rings l, . . . onto the piston P.

The piston ring assembling device 4 includes a gripping and assembling device 70 that grips a holding cup U and lowers and assembles the piston ring l from the holding cup U, and a gripping and assembling device 70 that moves the gripping and assembling device 70 vertically, front and back, and left and right. It consists of a moving device 60 for moving.

As shown in FIGS. 5 and 6, the moving device 60 extends back and forth along the conveyor C, and includes front and rear stands disposed on the pedestal 7 on the opposite side of the piston ring delivery device 3 with respect to the conveyor C. 61, a back-and-forth movable table 63 extending left and right as if to straddle the conveyor C, and supported by the inner surface of the front-rear table 61 on the conveyor C side so as to be slidable back and forth via a support member 62; A left-right motion table 6 that is supported so as to be slidable left and right.
4, and a vertically movable base 65 whose one end is supported by the horizontally movable base 64 in a vertically slidable manner and whose other end supports the gripping and assembling device 70. In addition, the back and forth motion table 6
3. It is assumed that both the horizontal movement table 64 and the vertical movement table 65 are moved by a drive source (not shown).

The gripping and assembling device 70 is as shown in FIGS. 7 to 9, and has two support rods 72, 7 on a vertically long substrate 71 supported by the vertically movable table 65.
2 is provided with a guide portion 73 through which the substrate 71 is slidably inserted vertically, and an upper connecting member 74 connecting the upper ends of the support rods 72 and 72 is provided with a guide portion 73 through which the substrate 71 is inserted.
A rod 75a of a built-in cylinder 75 supported downwardly is connected to the support rods 72, 72.
The lower end portion of is connected to a disc member 76 having an inner hole 76a.

Six inverted L-shaped fixing members 77 are fixed upwardly and downwardly at equal intervals in the circumferential direction on the upper and outer surfaces of the disk member 76, and on the lower surface side of the disk member 76 at the positions of the fixing members 77. , the same number of claw members 79 as the fixing members 77 are pivotally supported, the lower part of which is slightly bent downward, via the support member 78 . The claw member 7
A spring member 80 is installed between the claw member 9 and the fixing member 77 to press the lower part of the claw member 79 inward to a predetermined position. The lower end surfaces 79a, . . . of all the claw members 79, . . . are horizontal, and the lower end surfaces 79, .
It is assumed that a, ... are on the same horizontal plane.

The lower part of the substrate 71 has a small width and is inserted into the inner hole 76a of the disc member 76, and the lower end thereof is bent into an L shape and has a groove 81 penetrating vertically as shown in FIG. A pressing cylinder 82 having a rod portion 82a projecting downward is fixed to the base plate 71 slightly above the gripping portion 71a. That is, the support protrusion Ua of the holding cup U is inserted into the groove 81 of the gripping part 71a of the board 71, and the gripping part 71a
When the lower surface of the engagement portion Ub of the holding cup U is supported by the upper surface, the rod portion 82a of the pressing cylinder 82 fits into the recess Ub-1 of the engagement portion Ub and grips the engagement portion Ub of the holding cup U. part 71a and rod part 82
After all, the holding cup U is positioned and supported by this gripping and assembling device 70. If the holding cup U is to be placed in a predetermined position, the above procedure may be reversed.

The operation of the piston ring assembly device 4 will now be explained with reference mainly to FIGS. 5 and 10. Holding cup U on the conveyor C side of the support plate 40 in the original position A of the piston ring delivery device 3
is gripped by the gripping device 70, and the holding cup U is positioned by the moving device 60 on the piston P positioned on the pallet PA on the conveyor C. This holding cut is fitted with an oil ring l1,
It is assumed that the first compression ring l2 and the second compression ring l3 are held with their notches l1-1, l2-1, and l3-1 shifted in position.

Since the head portion Pa of the piston P on the assembly pallet PA is fixed upward, the holding cup U has its lower end surface U5 aligned with the lowermost ring of the piston P, as shown by b in FIG. Groove P1
The head Pa is inserted into the recess U3 and lowered until it coincides with the position of the upper surface P1-S of the head. Next, the rod 75a of the built-in cylinder 75 is extended,
By lowering the disc member 76, the claw members 79,..., which are pivotally supported by the disc member 76 via the support members 78,..., also descend, but the claw members 79,... When the inner ends 79b, . . . of 79a, . . . come into contact with the conical surface U1 of the holding cup U, the inner ends 79b, .
... are pushed outward, and the lower end surfaces 79a, ... of the claw members 79, ... descend along the conical surface U1 of the holding cup U. And this claw member 79,...
represents the three piston rings L, ... with their lower end surface U
1, . . . , the piston P is pushed downward by a predetermined distance until the lowermost oil ring l1 is finally fitted into the lowermost ring groove P1 of the piston P.

In this case, since the distance between the lower end surfaces 79a, . . . of the claw members 79, ... and the lower end surface U5 of the holding cup U is a constant value S, the oil ring l1 is
The predetermined distance K that the pawl member 79 needs to descend in order to attach it is K=S-t1-t2 where t1 is the thickness of the second compression ring and t2 is the thickness of the first compression ring.

becomes.

Next, the holding cup U rises slightly, and when its lower end surface U5 rises to the position of the upper surface P2-S of the intermediate ring groove P2 of the piston P, as shown by c in FIG. 10, the claw members 79,... The first compression ring l2 can be installed in the intermediate ring groove P2 by descending further from K by an amount t2, and the holding cup U is further raised slightly as shown by d in the 10th position, so that its lower end surface U5 is lowered. The claw members 79, . . . are positioned on the upper surface P3-S of the top ring groove P3 of the piston P.
If it further descends by t1, the second compression ring l3 will also be installed in the uppermost ring groove P3.

The positions of the piston P and the holding cup U may be shifted by lowering the piston P by a predetermined amount.

When all the piston rings l,... are assembled to the piston P as described above, the claw members 79,... are raised to a predetermined position by the built-in cylinder 75, and the empty holding cup U is moved by the moving device 60 to hold the piston rings. It is carried onto the support plate 40 at a predetermined position of the delivery device 3, and placed on the support portion 41 on the side of the conveyor C by the gripping and assembling device 70.

As described above, piston rings l1 and l2 are supplied from the piston ring stocker 1 to the piston P sequentially carried by the conveyor C via the piston ring supply device 2, the piston ring delivery device 3, and the piston ring assembly device 4. , l3 can be assembled continuously.

(Effects of the Invention) As is clear from the above, according to the present invention, by simply positioning the lower end surface of the holding cup in a predetermined ring groove of the piston and lowering the piston ring held by the holding cup to the predetermined position. Since the predetermined lowest piston ring can be assembled to this piston, the piston ring can be easily installed on the piston, and the piston ring can also be installed in the next ring groove of the piston using the holding cup. Since this can be done by simply moving the lower end surface slightly into the ring groove, aligning it, and lowering the piston ring to a predetermined position, the second and subsequent piston rings can be installed particularly quickly.

In addition, by shifting the positions of the notches on the retaining cup and holding the piston rings in the order in which they are assembled to the piston, the piston rings can be attached to the piston in the same state, making it easier to attach the piston rings to the piston. can be done correctly and reliably.

[Brief explanation of the drawing]

Figure 1 is a front view of the entire device, Figure 2 is a front view of the entire device.
3 is a cross-sectional side view of the piston ring supply device, FIG. 4 is a partial plan view of FIG. 3, FIG. 5 is a front view mainly showing the piston ring assembly device, and FIG. A side view of the piston ring assembling device, FIG. 7 is a partially sectional side view of the gripping and assembling device, FIG. 8 is a front view of FIG. 7, and FIG. 9 is taken along A-A of FIG. 8.
The arrow view and FIG. 10 are diagrams showing a state in which the piston ring is assembled to the piston. In the drawing, P is the piston, Pa is the head, and P is the piston.
1, P2, P3 are ring grooves, P1-S, P2-
S, P3-S are the upper surfaces of the ring groove, l, l1, l
2, l3 are piston rings, l1-1, l2-
1, l3-1 is a piston ring notch, U is a holding cup, and U1 is a conical surface.

Claims (1)

[Claims] 1. In a piston ring assembly method for assembling a piston ring to a piston having a plurality of ring grooves, the positions of notches are shifted from each other in a conical retaining cup whose outer circumferential surface expands in diameter downward. After fitting and holding a specified piston ring, insert it into the head of the piston into this holding cup, positioning the lower end surface of the holding cup on the upper side of the lowermost ring groove of the piston, and then insert the piston ring into the holding cup. While pressing down along this retaining cup, the lowermost piston ring is lowered from the retaining cup and attached to the piston, and then by lowering the piston or raising the retaining cup, the lower end surface of the retaining cup is inserted into the ring groove of the piston. A method for assembling a piston ring, which is characterized in that the piston ring is mounted on the piston by lowering the piston ring from the holding cup while sequentially aligning the piston ring with the upper surface of the piston.