JPS6057977B2 - Automatic piston assembly device - Google Patents

Description

DETAILED DESCRIPTION OF THE INVENTION The present invention relates to an automatic piston assembling device that automatically assembles a piston into a cylinder bore of a cylinder block of an engine.

In automatic assembly equipment, it is difficult to accurately align the center position of the cylinder bore of the transported cylinder block and the piston to be inserted into it every time, and there is always a slight misalignment between the piston and the cylinder block. This occurs between the cylinder bore and the cylinder bore. Therefore, the piston holding means that receives the piston to be inserted from the pallet and inserts it into the cylinder bore is required to have the ability to shift its position along the center of the cylinder bore.

Furthermore, a piston ring is fitted around the outer periphery of the piston to be inserted, and unless this piston ring is compressed, it is impossible to push the piston into the cylinder bore.

However, when the piston ring compression device is incorporated into the piston holding means, the piston holding means becomes large, which makes it difficult to movably support the piston holding means. Further, in a multi-cylinder cylinder block, the pitch interval between the cylinder bores is narrow, so it is difficult to incorporate the piston ring compression device into the piston holding means due to space considerations.

In the present invention, a piston holding cylinder of a simple shape is supported on the insertion head so as to be able to float in a plane perpendicular to the central axis of the piston holding cylinder at a pitch interval of the cylinder bore, and in each of the piston holding cylinders, a piston A piston push rod is provided so as to be movable back and forth parallel to the center axis of the holding cylinder, and a push plate is supported at the tip of the piston push rod so as to be able to float in a plane orthogonal to the center axis, and the piston is moved to the piston assembly position. Before inserting the piston on the carried pallet into the piston holding cylinder, a piston ring compression device is provided to sandwich the piston and compress the piston ring, and the piston is pushed up while the piston ring is being compressed. By providing a piston pushing device inserted into the piston holding cylinder, even if the center position of the cylinder bore and the piston deviates,
To provide an automatic piston assembling device capable of surely inserting a piston in alignment with the center of a cylinder bore.

DESCRIPTION OF THE PREFERRED EMBODIMENTS An embodiment of an automatic piston assembly apparatus of the present invention will be described in detail below with reference to the drawings.

FIG. 1 is an overall front view of the automatic piston assembly apparatus of the present invention, FIG. 2 is a plan view thereof, and FIG. 3 is a right side view thereof. A bed 2 is provided on the right side of the cylinder transport conveyor 1, which carries cylinder blocks S on a pallet Pa with the oil pan mounting surface SO vertically erected and sequentially transports them to an assembly station. Column 3 is erected. A swivel head 4 is rotatably supported on the front surface 3A of the column 3 so as to be pivotable and indexable in a vertical plane. There are two guide bars 5A, 5 on the front of the swivel head 4.
B is provided, and the insertion head 6 is guided by guide bars 5A, 5B so as to be slidable in a direction parallel to the pivot plane of the swivel head 4. A cylinder 7 is attached to the side of the swivel head 4. The tip of the piston rod 7A is fixed to the insertion head 6,
The operation of the cylinder 7 causes the insertion head 6 to slide back and forth.

A pinion 9 is keyed to the pivot axis 8 of the swivel head 4. In addition, the upper surface 3B of the column 3 is attached. A rack 11, which is reciprocated up and down by a cylinder 10 attached thereto, meshes with the pinion 9,
By reciprocating the rack 11, the swivel head 4 is
Rotate within a range of degrees. Accurate positioning of the rotation angle is achieved by moving the abutment plate 12 attached to the rear end of the rotation center shaft 8 to the stopper 13A attached to the rear surface 3C of the column 3.
Or by contacting 13B. Further, an abutment plate 14 is attached to the rear surface of the insertion head 6, a stopper 15 is attached to the front surface of the swivel head 4, and the abutment plate 14 is brought into contact with the stopper 15 at the forward end of the insertion head 6. The forward end position of the insertion head 6 is accurately positioned. A piston carry-in conveyor 16 is provided in a direction perpendicular to the conveyance direction of the cylinder conveyor 1, and the left end of the piston carry-in conveyor 16 is connected to the bed 2.
It is joined to the right side surface 2A of.

The piston carrying-in conveyor 16 carries four pistons P corresponding to the bore diameter of the cylinder (however, this varies depending on the number of cylinders of the engine) into groups, placing them on a pallet Pb and carrying them directly below the insertion head 6. Further, a pallet take-out conveyor 17 is installed in parallel with the piston carry-in conveyor 16, and carries out empty pallets Pb that have been assembled to the outside. The piston P is transported connected to the connecting rod C by a pin, but before assembly to the cylinder block S, the piston P in the connected state is
Then, the connecting rod C is cleaned and dried.

In order to effectively perform this cleaning (particularly the inner surface of the piston P) and drying, in the present invention, the piston P is placed on the pallet Pb with its top surface facing up and the skirt portion of the piston P covered. . That is, as shown in detail in FIGS. 4 and 6, the pallet Pb used in the present invention has a convex cross section, and has four projections 18A on its upper surface that fit into the inner peripheral surface of the piston P. , 18B, 18C, and 18D are provided in four sets at equal intervals. In addition, protrusions 18A and 18D
Grooves 19A and 19B are formed between them, and between 18B and 18C, through which the large end of the connecting rod C passes. The bottom surface of the pallet Pb is hollowed out to facilitate cleaning and discharge of cleaning liquid from below. The piston carrying-in conveyor 16 described above includes the conveyor 1
A separator 20 is provided for separating the pallets Pb conveyed on the insertion head 6 one by one and sending them to the insertion head 6 side.

The separator 20 is rotatably supported in a horizontal plane about a shaft 21, and has claws 23A and 23B at both ends that engage hook grooves 22 formed on the lower side of the pallet Pb. . This separator is driven by an actuator not shown. In the state shown in FIG. 2, the claw 23A engages with the hooking groove 22 of the leading pallet P, -2, and prevents the leading pallet P, -2 and the following pallets P, -3 from being carried in. Note that since the conveyor 16 is constantly driven, a gap occurs between the pallets Pb-2, Pb-3 and the conveyor 16. Pallet Pb-1 brought in previously
is transported by the piston transport conveyor 16 to the left end of the piston transport conveyor 16 shown in the figure, and then transported directly below the insertion head 6 by a claw 26 that slides back and forth along a guide bar 25 by a sill 24. be done. The pawl 26 is swung by a cylinder 27, swung downward to engage with the hooking groove 22 of the pallet P, -1, and swung upward and removed from the hooking groove 22. As described later, the pallet Pb
When piston P -1 is transferred to the insertion head 6, the empty pallet Pb-1 is returned to the left end of the piston carry-in conveyor 16 by the claw 26, and the claw 26 swings upward to remove the empty pallet Pb-1 from the hooking groove 22. It comes off.

A cylinder 28 is provided at the left end of the piston carry-in conveyor 16 in a direction perpendicular to the conveyance direction of the piston carry-in conveyor 16. 1), the empty pallet P,-1 is transferred onto the pallet delivery conveyor 17 shown by the two-dot chain line. When the empty pallet Pb-1 is transferred to the pallet unloading conveyor 17, the separator 20 swings clockwise, and one claw 23A moves the pallet P5-
At the same time, the other claw 23B engages with the hooking groove 22 of pallet Pb-3. Therefore, the pallet P5-2 is transported by the piston delivery conveyor 16.
The piston is conveyed to the left end of the conveyor 16, and is conveyed directly below the insertion head 6 by the same operation as described above. Next, the separator 20 swings counterclockwise, and the claw 2
When 3B leaves the hooking groove 22 of pallet P, -3,
Pallet Pb is moved by the movement of the piston carry-in conveyor 16.
-3's hooking groove 22 engages with the front pawl 23A and stops,
Prepare for the next loading operation. The pallet Pb is connected to the cylinder 24
When the pallet Pb is carried directly under the insertion head 6 by the claw 26 which is slid back and forth by the pallet Pb, as shown in FIG.
9A and 29B are presser plates 30A and 29B attached to the upper surface of the bed 2 in parallel to the conveyance direction of the piston carry-in conveyor 16,
It goes into the underside of 30B. A cylinder base 31 having a concave cross section is attached to the lower surface of the holding plates 30A, 30B, and the flanges 29A, 29B of the pallet Pb are sandwiched between the upper surface of the cylinder base 31 and the holding plates 30A, 30B. On the bottom surface of the cylinder base 31, there is a pallet PY
) Four cylinders 32A to 32D (FIG. 1) are attached at the same intervals as the pistons P on the cylinder.

Piston rods 33A to 3 of each cylinder 32A to 32D
At the upper end of 3D are push plates 34A to 34D with semicircular cross sections.
is installed, and the piston rods 33A to 33D
As the connecting rod C rises, it comes into contact with a bearing formed at the large end of the connecting rod C and pushes the connecting rod C upward. As shown in FIGS. 4 and 5, a pallet Pb carried directly under the insertion head 6 is placed on the upper surface of the bed 2.
A piston ring compression device 35 is attached that sandwiches the upper piston P and compresses the piston ring Pr fitted into the piston P. That is, a cylinder base 36 is attached to the upper surface of the bed 2, and a cylinder 37 is attached to the cylinder base 36. Further, a cylinder 38 having a smaller diameter than the cylinder 37 is attached to the lower front surface of the column 3 so as to face the cylinder 37 . At the tips of the piston rods 37A and 38A of the cylinders 37 and 38, there are wide plates 39 and 40.
are screwed together. Pressing pads 41A to 41D and 42A to 42D, whose tips are shaved off into semicircular shapes, are attached to the plates 39 and 40 to face each other at the same spacing as the piston P. In addition, two guide bushes 43 are provided at the lower front surfaces of the cylinder base 36 and the column 3.
A, 43B and 44A, 44B are attached facing each other. The plates 39 and 40 have the guide bushes 43A,
Guide bars 45A, 45B, 46A, and 46B that fit into and slide on 43B, 44A, and 44B are attached. The ends of the guide bars 45A, 45B have large diameter portions 47A.
, 47B are formed, and guide bushes 43A, 4
By hitting the end face of 3B, the pressing pads 41A~
Accurately locate the stop position of 41D. That is, as described above, since the cylinder 37 has a larger pressure receiving area than the cylinder 38, the plate 39 moves forward until the large diameter portions 47A, 47B abut against the guide bushes 43A, 43B, and the pressing pads 42A to 42D of the plate 40 move forward. The piston P is sandwiched between the press pads 41A to 41D of the plate 39, and the piston ring Pr is compressed.
Align the center of the piston P with the center of the piston holding cylinder. In this way, the piston ring Pr is compressed by the piston ring compression device 35, and the push-up cylinders 32A to 32D are operated to push up the piston P and insert the piston P into the piston holding cylinder. The detailed structure of the insertion head 6 shown in FIGS. 7, 8, and 10 will be explained.

Four cylindrical piston holding tubes 49A to 49D are inserted into the cavity 48 formed on the front side of the insertion head 6 at the same intervals as the pistons P on the pallet Pb. Flanges 50A to 50D and 51A to 51D are welded to the upper and lower outer peripheral surfaces of the piston holding cylinders 49A to 49D.
On the front surface 6A of the insertion head 6, there are piston holding cylinders 49A to 49A.
Plates 52A and 52B extending horizontally are inserted above and below 49D, and the ribs 50A to 50D and 51A to 51D are sandwiched between the plates 53A and 53B from the front side. Vertically elongated spacers 54A, 54B (FIG. 8) are interposed between the plates 52A, 53A and 52B, 53B.
It is tightened by four bolts. Brim 50
Between A~50D and the plates 52A, 53A, and the brim 51A~
A ball 56 held by a retainer 55 is interposed between the plate 51D and the plates 52B and 53B. It is inserted.

Therefore, the piston holding cylinders 49A to 49D are connected to the plates 52A,
It is sandwiched between 53A, 52B, and 53B and can float lightly within a plane perpendicular to the central axis of the piston holding cylinders 49A to 49D. Brim 50A to 50D and 51
Through holes 57 are bored in A to 51D in parallel to the central axes of the piston holding cylinders 49A to 49D. A bush 58 is fitted into the through hole 57, and the plates 52A, 53A, 52B,
Balls 60A and 60B are inserted to be pressed against 53B. Conical holes 61A, 61B into which the balls 60A, 60B fit are formed on the inner surfaces of the plates 52A, 53A and 52B, 53B. Therefore, the central axes of the piston holding cylinders 49A to 49D are held at the required center position of the cylinder bore Sb by the cooperation of the balls 60A, 60B and the conical holes 61A, 61B. The intermediate partition wall 6B of the insertion head 6 has piston holding cylinders 49A to 4.
Cylinders 62A to 62D are attached on the same center line as cylinder 9D.

The cylinders 62A to 62D have pistons 63A to 63D.
are slidably inserted into the pistons 63A to 63JD, and hollow piston rods 64A to 64D are formed at the front and rear of the pistons 63A to 63JD. Push rods 65A to 65D are inserted into the hollow portions of the piston rods 64A to 64D. push rod 65
Disc-shaped push plates 67A-67D and 68A-68D are attached to the tips of A-65D with a thrust bearing 66 in between. Front push plates 68A to 68D and push rods 65A to 65 in direct contact with the top surface of the piston P
Since elastic bodies (such as rubber) 69A to 69D are inserted between D, if the center of the cylinder bore Sb and the center of the piston holding cylinders 49A to 49D do not coincide, when the piston P is inserted, The push plates 68A to 68D are easily moved and centered together with the piston P at the center of the cylinder bore Sb, and the insertion operation of the piston P can be performed smoothly. Brackets 70A-70D are welded to the rear portions of the hollow piston rods 64A-64D.

In addition, as shown in FIGS. 7 and 10, the insertion head 6
Between the support stands 71A to 71D attached to the bottom surface 6C of the insertion head 6 and the rear wall 6D of the insertion head 6, cylinders 62A to
Guide bars 72A to 72D are attached parallel to 2D, and through holes 7 are bored in the brackets 70A to 70D.
3A to 73D are fitted into the guide bars 72A to 72D, and the brackets 70A to 70D and the piston rod 64A
~64D is prevented from rotating. piston rod 6
Flanges 74A to 74 formed at the front ends of 4A to 64D
A spring 75 is installed between D and the rear push plates 67A to 67D.
A to 75D are inserted, and the push plates 67A to 67D, 68
A to 68D and push rods 65A to 65D are always urged forward with respect to piston rods 64A to 64D.

Blocks 76A to 76D are located at the rear of the push rods 65A to 65D.
are pinned, and blocks 76A to 76D are fitted into long grooves 77A to 77D formed in brackets 70A to 70D, and push rods 65A to 65D and blocks 76A to 76
D is stopped from rotating. As mentioned above, the springs 75A~
Since the push rods 65A to 65D are urged forward by the push rods 75D, the blocks 76A to 76D abut against the rear end surfaces of the piston rods 64A to 64D and are stopped.

Bolts 78A to 78D are screwed into blocks 76A to 76D, and limit switches 79A to 79D attached to brackets 70A to 70D are connected to bolts 78A to 78D.
The tip of 8D is always pressed. Piston 63A-63D
When the piston P moves forward and is pushed into the cylinder bore Sb by the push plates 68A to 68D, there is no problem if it is pushed in smoothly, but if the piston P gets caught while being pushed, the piston rods 64A to 64D 64D and push rod 65
Relative movement occurs between A and 65D.

In other words, only the piston rods 64A to 64D are connected to the spring 75A.
~75D, and the tips of the bolts 78A~78D separate from the limit switches 79A~79D, detecting a pushing abnormality, stopping the supply of pressure oil to the cylinders 62A~62D, and at the same time turning on warning lamps, etc. This will notify the operator of the abnormality. Dogs D-1 and D-2 are attached to the rear ends of the push rods 65A to 65D, and by stepping on limit switches 80A to 80D and 81A to 81D, the forward and backward ends of the pistons 63A to 63D are detected. Confirmation of completion of pushing of piston P and push plate 68A~
Confirm that 68D has completed its retreat.

As mentioned above, the cylinder block S is placed on the pallet Pa and transported on the cylinder transport conveyor 1, and when it is transported to a position facing the insertion head 6, the cylinder block
2 rises, lifts up the cylinder block S together with the pallet Pa, and holds the cylinder block S between it and the gate-shaped fixture 83.
Position and fix. In order to smoothly and continuously perform the piston insertion operation performed in the present invention and the subsequent connecting rod cap assembly operation, the cylinder block S is placed with the cylinder head mounting surface Sh upright. It is placed on a pallet Pa and transported. As shown in FIGS. 1 and 2, a cylinder conveyor 1
A bed 84 is provided on the left side of the head 6, facing the insertion head 6.

Two guide bars 85A, 85 are provided on the top surface of the bed 84.
A guide head 86 is mounted on the guide bars 85A, 85B so as to be slidable in parallel to the central axis of the cylinder bore Sb. A cylinder 87 is attached to the left side of the bed 84, and the tip of its piston rod 87A is fixed to the guide head 86, and the operation of the cylinder 87 causes the guide head 86 to reciprocate. The thrust force of the cylinder 87 is set smaller than the sum of the thrust forces of the cylinders 62A to 62D for inserting the piston P described above. The guide head 86 has a cylinder bore Sb.
Four guide forks 88A to 88 at the same pitch interval as
D is attached.

As shown in FIGS. 7 and 10, the guide fork 88A
~88D has a bifurcated tip, enters the cylinder bore Sb across the crankshaft Cr, and comes into contact with the large end face of the connecting rod C at the forward end (right end) of the guide head 86. . As shown in FIGS. 7 and 9, the large end of the connecting rod C has a
Since the bolts 89A and 89B for tightening the connecting rod cap are inserted, the guide forks 88A to 88D avoid the bolts 89A and 89B.
so that it comes into contact with the end face of the large end of the connecting rod C.
An R-shaped relief is formed. In order to insert the piston P, move the pistons 63A to 63D forward and press the push plate 68A.
〜68D, the piston P moves toward the cylinder bore S.
When pushed into b, the guide forks 88A to 88D are
With its tip still in contact with the large end of the connecting rod C, it moves backward (moves to the left) due to the difference in thrust between the cylinders, and guides the large end of the connecting rod C to the crankshaft Cr. I'm nervous.

Next, the piston assembling operation of the automatic piston assembling apparatus of the present invention will be explained.

After operating the cylinder 7 to retract the insertion head 6 to the retracted end, the cylinder 10 is operated to rotate the swivel head 4 90 degrees counterclockwise from the state shown in FIG.

When the rotation operation is completed, the cylinder 7 is operated again to advance and lower the insertion head 6 until the abutting plate 14 hits the stopper 15. Next, the piston P on the pallet Pb carried directly below the insertion head 6 is pinched by operating the piston ring compression device 35 to compress the piston ring Pr, and then the cylinders 32A to 32D for pushing up are operated. Then, the four pistons P are simultaneously pushed up and pushed into the piston holding cylinders 49A to 49D of the insertion head 6. As described above, the piston holding cylinders 49A to 49D are connected to the insertion head 6.
Since the piston P and the piston holding cylinders 49A to 49D are supported in a floating manner, even if there is a slight deviation in center position between the piston P and the piston holding cylinders 49A to 49D, the piston holding cylinders 49A to 49D follow the piston P.
9D moves to smoothly insert the piston P. After the cylinder 7 is actuated to move the insertion head 6 backward (raised), the cylinder 10 is actuated to turn the swivel head 4 90 degrees clockwise.

Big end of connecting rod C and piston holding cylinder 49
There is only a slight gap between the inner peripheral surfaces of the pistons A to 49D, and the swivel head 4 rotates in a plane perpendicular to the direction of pivoting of the connecting rod C with respect to the piston P. Therefore, during the pivoting operation of the swivel head 4, the position of the connecting rod C hardly shifts within the piston holding cylinders 49A to 49D, so that there is no problem in the assembly operation. Next, when the cylinder 7 is actuated again to advance the insertion head 6 and the abutment plate 14 is brought into contact with the stopper 15, the front end of the insertion head 6 is moved as shown in FIGS.
As shown in Figure 0, it stops slightly before hitting the cylinder head mounting surface Sh. Next, the cylinder 87 is actuated to move the guide head 86 forward (to the right), and the guide fork 88
Insert A to 88D into the cylinder bore Sb. Subsequently, cylinders 62A to 62D are operated simultaneously to push plate 68A.
~68D moves the piston P into the cylinder bore Sb! Push it in. As described above, since the push plates 68A to 68D and the piston holding cylinders 49A to 49D are supported so as to be able to float, even if there is a slight misalignment between the piston P and the cylinder bore Sb, the piston holding cylinder 49A is moved in accordance with the cylinder bore Sb. 49D and the push plates 68A to 68D move to smoothly insert the piston P. In addition, since the piston P and the connecting rod C are inserted while being sandwiched between the guide forks 88A to 88D and the push plates 68A to 68D, the connecting rod C does not wobble during the insertion operation, and the connecting rod C is not easily connected to the crankshaft Cr. The large end of the rod C can be guided smoothly. When the insertion operation is completed, the cylinders 62A to 62D are operated to release the push plate 68A.
~ 68D and at the same time actuated the cylinder] 7 to move the guide head 86 backward (to the left), the Liptor 82
is lowered, the cylinder conveyor 1 is operated, and the cylinder block S, which has been assembled, is sent to the next station.

At the same time, a new cylinder block S was brought in and the Lipta 8
2 is raised and fixed to the fixture 83, and the piston assembly operation described above is performed again. According to the present invention, the piston ring compression device is not provided in the piston holding cylinder, and the piston rings of the pistons placed on the pallet are compressed by a piston ring compression device provided separately. Since the piston is pushed inward, the structure of the piston holding cylinder is simplified, and as a result, there is an advantage that the piston holding cylinder can easily float.

In addition, as mentioned above, since the structure of the piston holding cylinder is simplified, it is possible to line up as many piston holding cylinders as there are cylinder bores in a row, and to assemble multiple pistons at the same time in one piston assembly operation. It also has the effect of reducing time.

As detailed above, the present invention is not limited to the configurations shown in the examples, and modifications are expected without departing from the technical idea of the present invention as described in the claims. By the way.

[Brief explanation of the drawing]

Fig. 1 is an overall front view of the automatic piston assembly device of the present invention, Fig. 2 is a plan view thereof, Fig. 3 is a right side view, Fig. 4 is a longitudinal sectional view of the piston ring compression device, and Fig. 5 is a plan view including a cross section of the same part, and FIG. 6 is a pallet Pb for loading and unloading pistons.
7 is a cross-sectional view of the insertion head 6, FIG. 8 is a partially sectional left side view of the insertion head 6, and FIG. 9 is a view taken from A--A in FIG. 7. A cross-sectional view and FIG. 10 are vertical cross-sectional front views of the insertion head 6.

Claims (1)

[Claims] 1. A pallet for carrying the piston in and out of the piston assembly position with the top surface facing up and the connecting rod assembled with the piston suspended, and a cylinder block to be assembled in a position facing the pallet. an insertion head that is movable between opposing positions; a piston holding cylinder that is provided on the insertion head at the same pitch interval as the cylinder bore and in the same number as the cylinder bore and into which pistons can be inserted; a floating support device supported on the insertion head so as to be able to float within a plane; a piston push rod provided in each of the piston holding cylinders so as to be able to reciprocate in parallel to the central axis of the piston holding cylinder; a push plate provided at the tip and capable of coming into contact with the piston top surface; a floating support device that supports the push plate on a push rod so as to be able to float within a plane perpendicular to the central axis of the piston holding cylinder; and the piston assembly. a piston ring compression device that compresses a piston ring fitted into the piston by sandwiching a piston on a pallet carried to a fixed position;
An automatic piston assembling device comprising: a piston pushing device that pushes up a piston on a pallet carried into the piston assembling position and inserts it into a piston holding cylinder of the insertion head.