US3486551A - Casting machine - Google Patents

Description

' Dec. 30, 1969 YOSHIJI mouE CASTING MACHINE s Sheets-Sheet 1 Filed Oct. 5, 1966 INVENTOR- YOSH/J/ INOUE iaw ATTY'S YVOSHIJI INO'UE CASTING MACHINE Dec. 30, 1969 6 Sheets-Sheet 2 Filed vOct. 8, 1966 mvE/v TOR YOSHIJI INOUE I 'ATTY'S Dec. 30, 1969 YOSHIJHNQ'I'UE CASTING MACHINE" 6 Sheets-Sheet 5 Filed Oct. 5. 1966 INVENTOR YOSH/J/ INOUE 5 M 1m fi iww ATTY'S Dec. 30, 1969 wast-IL" mdua 3,486,551

- CASTING 'iaAcumE Filed Oct. 5. 1966 e Sheets-Sheet 4 INVENTOR 'YOSH/Jl uvou .21 4.) j/W Q M ATTY'S Dec. 30, 1969 YOSHIJI INOUE 3, 55

- I CASTING MACHINE Filed Oct. 5. 1966 e Sheets-Sheet 5 ATTY'S Dec. 30, 1969 YOSHIJI 'INOUE 3,486,551

, CASTING MACHINE Filed Oct. 5, 1966 6 Sheets-Sheet 6 I\- a E Q P- g INVENTORY gOSH/Jl INOUE M W ATTY'S United States Patent 3,486,551 CASTING MACHINE Yoshiji Inoue, Kobe, Japan, assignor to Kanzakl Kokyu Koki Mfg. Co., Ltd.

Filed Oct. 3, 1966, Ser. No. 583,786 Claims priority, application Japan, July 9, 1966, 41/ 44,897 Int. Cl. B22d 13/00 US. Cl. 164-286 8 Claims ABSTRACT OF THE DISCLOSURE The present invention relates to a method and apparatus for centrifugal casting and more especially to the method and apparatus for centrifugal casting having plural number of moulds, enabling the hole mechanisms automatically down extremely easy and, at the same time, the casting continuously down.

In conventional centrifugal casting apparatus castings are repeatedly made in one rotating mould and the successive steps of casting, cooling, de-moulding, scavenging, coating, and temperature re-adjusting of the mould take a long time for the production of a casting, which makes the process ineflicient.

The present invention has for its object to overcome this disadvantage.

According to the present invention there is provided a method of centrifugally casting a plurality of workpieces comprising the steps of moving a set of centrifugal casting moulds cyclically in sequence through a number of working stations including a casting station in which a mould is rotated and receives a charge of molten metal, a casting removal station in which the mould is not rotated and the casting is removed and at least one mould conditioning station for preparing the mould for receiving a further charge of metal in the casting station.

Further, according to the present invention there is provided centrifugal casting apparatus comprising a mould-carrying turret mounted for rotation about its axis, a set of centrifugal casting moulds rotatably mounted in the turret at equal angular spacings and at the same distance from the turret axis, disengageable driving means for selectively rotating each of the moulds, means for periodically rotating the turret in one direction through a predetermined angle so as to move the moulds cyclically in sequence through a set of working stations including a casting station provided with means for pouring a charge of molten metal into a rotating mould, a casting removal station provided with means for disengaging the drive to the mould and for removing the casting from the mould and at least one mould conditioning station for preparing the mould for receiving a further charge of metal at the casting station.

The dispersed positions of the castings, cooling, demoulding and conditioning stations such as for scavenging, coating and temperature readjusting enable each operation to be performed efficiently.

It will be noted that only one mechanism for carrying out each working operation is required and this serves several moulds.

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Consequently the apparatus is simplified.

An embodiment of the invention will now be described by Way of example with reference to the accompanying drawings, in which- FIGURE 1 shows a general perspective view of the apparatus with parts broken away,

FIGURE 2 is a perspective view of a portion not shown in FIGURE 1,

FIGURE 3 shows in longitudinal section one mould and its driving mechanism,

FIGURE 4 is a vertical section of the casting mechanism, 1

FIGURE 5 represents a Vertical longitudinal section through the de-moulding mechanism,

FIGURE 6 shows a vertical longitudinal section through the scavenging mechanism and FIGURE 7 is a vertical longitudinal section through the coating mechanism.

The embodiment of the invention shown in the drawis a centrifugal casting machine having six moulds 30 equally angularly spaced at 60 intervals around the axis of a turret formed by a drum 21. The drum 21 is rotatable about its axis and the moulds 30 are moved intermittently through 60 steps by means of a driving mechanism to be described below so that each mould 30 moves cyclically through six working stations A, B, C, D, E, F, in one complete revolution of the drum 21.

A working operation is carried out at each working station. The operations are: casting, cooling, de-moulding, scavenging, coating and temperature readjusting.

An electric motor 11 drive a main shaft 52 by means of a reduction gear 12, a pulley 51, a belt 13 and a pulley 14 on the main shaft 52. The main shaft 52 carries a sun gear 15 which meshes with'six pinions 17. Power from the main shaft 52 is thus transmitted to the six pinions 17 which are each rotatably mounted a free-moving clutch shaft 16. The pinions 17 rotate continuously.

Each clutch shaft 16 carries a side clutch 18 which, when engaged, transmits the rotation of the associated pinion 17 to the clutch shaft 16 so that a pinion 19 fixed to the clutch shaft 16 rotates through the clutch 18. The pinion 19 meshes with a mould-driving gear 20 whose rotation is transmitted to the mould 30 through a mouldmounting frame 53. Accordingly, the six moulds 30 are selectively driven rotationally by engagement of the six side clutches 18 effected by a cam to be described below, so that in the working stations A, B, D, E, F, the moulds 30 rotate while the mould 30 in the working station C does not rotate. The term rotation used herein means a rotation around a stationary axis and therefore it is distinctively used as a revolving circular movement.

The main shaft 52 is supported by the frame 22 which also carries the cam 23. Six cam-follower rollers 24 each rotatably mounted on a roller fitted bed 70 engage cam 23. The surface of the cam 23 is not even and thus the push rod 25 moves back and forward in accordance with the said movement of the roller 24. By this movement of the push rod 25 the said dog clutch 18 which relates with the push rod 25 moves back and forward so as to engage or disengage the clutches 18 to start or stop the rotation of the moulds 30.

In order to rotate the drum 21 intermittently, a ratchet wheel 27 coaxial with the drum is fixed to it, a pawl carrier 54 is mounted for rocking movement about the drum axis on the ratchet wheel 27, and a pressure-oil operated ram 26 has a piston rod 55 connected to the pawl carrier 54. The pawl carrier 54 carries a driving pawl 28. The ratchet wheel 27 is also engaged by an anti-reversing pawl (not shown). To keep the rotation of the drum 21 exactly at 60 degrees, the drum has six recessed locating bosses 29 spaced at 60 intervals and these recessed bosses are engaged by plungers 48 operated by locating cylinder 56.

Each mould-mounting frame 53 supports a back c ver 33 for the mould 30 and the said back cover 33 has a push rod 32 for ejecting the cast product 31 (FIG- URES 1 and 3). The push rod 32 is actuated by the piston 49 of a pneumatic ram 40 mounted on the frame 22.

At the working station A (FIGURES 1 and 4) is located a casting mechanism having a front cover 34, a molten metal weighing vessel 35, a receptacle 37 for molten metal 36 and a channel 38 for molten metal 36.

At the working station B is located a cooling mechanism having water spray piping 39 for cooling the mould in the working station B.

At the working station C (FIGURES 1 and 5) is located the demoulding mechanism comprising, as described above, the ram operated push rod 32 and a shoot 41 on to which the casting 31 is pushed.

At the working station D (FIGURES 1 and 6) is a scavenging mechanism comprising a carriage 42 mounted on rails 57, a rotary wire brush 43 carried by the carriage 42 and arranged to rotate against the inner wall of the mould 30 and a vacuum suction system 44.

At the working station E (FIGURE 7) is a coating mechanism, a carriage 47 mounted on rails 58, a compressed air nozzle 46, a spray nozzle 45 for coating liquid and a tank 50 containing the coating liquid. At the mould working position F is a temperature readjusting mechanism having a water spray piping system (not shown in the drawings) for temperature readjustment.

In operation, after the electric motor 11 and other power supplies have been switched on, the piston rod '55 of the ram 26 starts reciprocating periodically under the action of an oil pressure control mechanism (not shown in the drawings). This periodic reciprocating motion of the piston rod 55 moves the ratchet wheel 27 periodically through steps of 60 in the left direction only (anti-clockwise direction in FIGURE 1) so that the drum 21, being attached to the ratchet wheel 27 moves with it and each mould 30 while making a stop at each of the working stations A, B, C, D, E and F in turn, revolves intermittently. Between such moves, the recessed locating bosses 29 on the said drum 21 are engaged by the locating plungers 48 to position the drums correctly.

Power from the electric motor 11 is transmitted to the six pinions 17 through the gearbox 12, pulley 51, belt 13, pulley 14, main shaft 52 and sun gear 15 so that the pinions 17 rotate continuously. The push rods 25 move under the actions of the cam-follower rollers 24 as they travel round the cam track 23 on the frame 22 and as a result of this motion, each clutch periodically engages so as to drive its associated pinion 19. The rotation of the pinion 19 is transmitted to the mould 30 through the mould driving gear 20 and the mouldmounting frame 53 so that the mould 30 rotates. When however the clutch 18 is disengaged, the mould 30 does not rotate.

The various working operations carried out at the respective working stations A, B, C, D, E and F will now be described.

The Working station A, as shown in FIGURE 4 comprises a pouring mechanism for pouring molten metal 36 into the mould 30. When the mould 30 is moved with the drum 21 60 by the ram 26 from position F to position A and held there, the said pouring mechanism is advanced towards the mould 30 by a hydraulic ram and the front cover 34 comes into contact with the mould 30. As the mould 30 is rotationally driven by the moulddriving gear 20 at this moment, the front cover 34 rotates in contact with the mould 30. Then the molten metal weighing ladle 35 tips forward to pour the molten metal 36 in the ladle 35 into the mould 30 through the channel 38 in the receptacle 37. When the casting operation has been finished and the molten metal is more or less solidified, the pouring mechanism is retracted to its original position.

Thereafter the drum 21 again turns through 60 to move the mould 30 to the working station B from position A. Here cooling water from the water spray pipe 39 cools down the mould 30 which rotates with the casting 31 inside it, and about its stationary axis.

When the drum 21 again turns through 60, the mould 30 moves from the working station B to station C and stays there and, at the same time, its rotation about its axis stops. The casting 31 is then removed from the mould 30 by the push rod 32 actuated by the plunger 49 operated by the air cylinder 40, the back cover 33 pushing the casting 31 out onto the shoot 41. At this moment, compressed air is blown into the clearance 62 between the push rod 32 and the mould-mounting frame 53 and also the inside of the mould 30 through fluid passage 59, 60 and nozzles 61 in the push rod 32, any residues of coating agents remaining on the push rod 32, the inner wall of the mould-mounting frame 53 and the mould 30 are readily removed but also the coating agents, which would otherwise be likely to find their way into the clearance 62 leading onto the mould 30, are readily prevented from entering. When the removal of the cast product has been completed the push piston 49 is returned to its original position by the air cylinder 40.

Then the drum 21 again turns through 60 to move the mould 30 from the position C to the station D, the clutch 18 being at the same time re-engaged to rotate the mould 30 again.

At the working station D, as shown in FIGURE 6, the scavenging mechanism moves forward and the rotating wire brush 43 is inserted into the mould 30 while pushing back the rod 32 which was left in the mould 30 in the previous working step. As a result of the rotation of the wire brush 43, coating materials presenting on the inner wall of the mould 30 are dislodged and removed by the vacuum suction device 44. At the suction port 64 of the suction pipe 63 of the vacuum suction device 44 is a flange-like passage control body 65 having a slightly smaller diameter than the inner diameter of the mould 30 so that the air-flow speeds are greatly accelerated at around the outer circumference and any particles adhering to the inner wall of the mould 30 come under the powerful influence of the suction force due to the centrifugal force of the rotation of mould 30 and the particles are completely removed through the suction pipe 63.

When the scavenging operation finishes, the drum 21 again turns 60 and the mould 30 leaving the working station D moves to the working station E and stays there. At the working station E, as illustrated in FIGURE 7, is a coating mechanism, of which, when the mould 30 stops at the station E, the carrier 47 moves forward to wards the mould 30 to hold the spray nozzle 45 in position for coating and the high-pressure air nozzle 46 in the mould 30 so that the coating operation is effected by spraying the mixture of coating material and air on to the inner wall of the mould 30 which is rotating.

When the cooling operation is finished, the drum 21 again turns through 60, and the mould 30 thus moves from the station E to the station F and stays there. At the working station F temperature readjustment is effected by spraying temperature-readjustment water (generally cooling water but pre-heating water) onto the mould as in the same manner as working station B.

Then the drum 21 again turns through 60". When the mould 30 moves to a position A from position F a complete operation starting from position A to position F has been completed and this operation is now repeated.

The order of the working step has been given above in detail for one mould 30; all six moulds 30 undergo the same cycle of steps at intervals of 60.

What I claim is:

1. Centrifugal casting apparatus comprising a mouldcarrying turret mounted for rotation about its axis, a set of centrifugal casting moulds rotatably mounted in the turret at equal angular spacings and at the same distance from the turret axis, disengageable driving means fdr selectively rotating each of the moulds, means for periodically rotating the turret in one direction through a predetermined angle so as to move the moulds cyclically in sequence through a set of working stations including a casting station provided with means for pouring a charge of molten metal into a rotating mould, a casting removal station provided with means for disengaging the drive to the mould and for removing the casting from the mould while stationary and at least one mould eonditioning station for preparing the mould while rotating for receiving a further charge of metal at the casting station.

2. Centrifugal casting apparatus according to claim 1, wherein the number of centrifugal casting moulds in the turret is equal to the number of working stations.

3. Centrifugal casting apparatus according to claim 1, wherein there are a plurality of mould conditioning stations including a scavenging station with means for removing residues from the internal wall surfaces of the mould and a coating station with means for applying a coating to the internal wall surfaces of the mould.

4. Centrifugal casting apparatus according to claim 3, wherein each mould includes an axially movable push rod for ejecting the casting at the casting removal station and the scavenging station includes means for blowing compressed air along the push rod into the mould, means for dislodging residues from the inner wall surfaces of the mould and suction means for removing the material so dislodged.

5. Centrifugal casting apparatus according to claim 1, wherein the pouring mechanism at the casting station in eludes a measuring ladle arranged to tip and discharge its contents into the mould when the quantity of molten metal in the measuring ladle reaches a predetermined value corresponding to the required charge to be poured into the mould.

6. Centrifugal casting apparatus according to claim 1, wherein the means for selectively rotating each of the moulds comprises a motor-driven sun gear co-axial with the turret, a pinion for each mould meshing with the sun gear and a clutch for each mould interposed between the pinion and the mould, the said clutches being engageable or disengageable selectively by means of cam followers co-operating with a cam track extending around the axis of the turret.

7. Centrifugal casting apparatus according to claim 1, wherein there are a plurality of mould conditioning stations with the selectively operable means rotating a mould at each conditioning station.

8. Centrifugal casting apparatus according to claim 1, wherein the means for selectively rotating each of the moulds comprises a driven pinion for each mould and a clutch for each mould interposed between the pinion and the mould, the said clutches being selectively engageable or disengageable to rotate a corresponding mould or allow the same to remain stationary.

References Cited UNITED STATES PATENTS I. SPENCER OVERHOLSER, Primary Examiner D. W. JONES, Assistant Examiner US. Cl. X.R.

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