US3482652A - Automatic reciprocating lubricant applicator - Google Patents

Description

. 9, 1969 F. T. STONE 1n 3,482,652

AUTOMATIC RECIPROCATING LUBRICANT APPLICATOR Filed Nov. 13, 1967 4 Sheets-Sheet 1 a B 6W4, AQ, m w

AUTOMATIC RECIPROCATING LUBRICANT APPLICA'I'OR Filed Nov. 13, 1967 F. T. STONE lll Dec. 9, 1969 4 Sheets-Sheet 2 5 WW z 9 W W p@ AUTOMATIC RECIPROCATING LUBRICANT APPLICAI'OR Filed Nov. 13, 1967 F. T. STONE Ill Dec. 9, 1969 4 Sheets-Sheet 5 INVENTbR. FZA/VZ 7. I'm/V6127 AUTOMATIC RECIPROCATING LUBRICANT APPLICATOR Filed NOV. 13, 1967 4 Sheets-Sheet. 4

F. T. STONE Ill BY 6M 1M A TTORNEYS.

United States Patent 3,482,652 AUTOMATIC RECIPROCATING LUBRICANT APPLICATOR Franz T. Stone III, Columbus, Ohio, assignor to Rimrock Corporation, Columbus, Ohio Filed Nov. 13, 1967, Ser. No. 682,029 Int. Cl. F16n 13/22, 29/00; F16m 1/00 US. Cl. 184-15 7 Claims ABSTRACT OF THE DISCLOSURE An apparatus for automatically applying liquid lubricant and the like to working surfaces of various types of forming apparatus such as molds and dies. The apparatus utilizes a spray manifold containing one or more spray heads, carried at the end of an operating rod connected to the piston of a pneumatic cylinder. Valves operating in response to electronic timers control the cylinder and the spraying mechanisms, to regulate the speed of travel of the spray head during various time intervals during extension and retraction and the functioning of the spraying mechanisms during the different time intervals.

BACKGROUND OF THE INVENTION This invention relates to the lubricating and cleaning of various working surfaces such as in dies and molds for forming metals and other materials and especially to the automatic spraying of the mold or die surfaces with a lubricant between forming cycles while the opposed die sections or mold sections are opened. More particularly the invention relates to reciprocating type automatic spraying devices which travel past the working surfaces between operating cycles and, during selected time intervals, spray the lubricating material on the surfaces, and at other time intervals emit an air blast to remove flash and the like formed at parting lines and to cool the working parts.

In many industrial forming processes such as the molding, die casting, drawing and forging of metals and other materials, it is common practice to apply a lubricant to the working surfaces between each forming cycle. At the same time, while the mold or die sections are separated, other operations are often performed such as blowing air against the forming surfaces to remove any residual flash that may remain around the die cavities and also to cool surfaces which are difficult to cool with the integral circulating cooling system normally provided. The lubricant, which is generally in liquid or powdered form, improves the flow of the metal or other material being formed, reduces wear of the working parts and facilitates removal of the newly formed product from the mold or die.

To apply the lubricant automatically and thus avoid the necessity of having a worker move between the opposed platens of an open die or mold between cycles, mechanical reciprocating devices are often used. These devices move a spray head past the surfaces of the mold or die to be lubricated while the platens are separated, and spray intermittently so as to apply the lubricant to the desired surface parts. Such devices commonly have air blast nozzles as well to help cool various working parts and also to remove flash.

When the forming cycles are repeated quite rapidly it is necessary to move the spray head and associated equipment at a high speed between the open die sections since the dwell time during which the mold or die platens re main open after removal of the newly formed part is relatively short. Since it is normally diflicult to speed up the actual spraying time and still achieve effective lubrication it is most important that the time intervals during To provide the needed flexibility, hydraulic cylinders have been generally used to drive the reciprocating spray head and restricter valves used to vary the speed of travel of the piston. Cams operated by the piston rod or operating rod have also been provided to operate micro switches which in turn operate solenoid valves that control the speed and function during the various time intervals of the cycle.

While this approach to the problem is adequate for many circumstances, the positioning of the cams must be quite precise and has in the past required considerable time for adjustment and readjustment in order to obtain satisfactory results. In many applications the molds or dies are changed quite frequently depending upon the particular product to be formed, and with each change the cams must be manually positioned and readjusted by trial and error in order to set the speed and functions for the particular die shape and configuration.

In particular, a high degree of accuracy in the positioning of the cams is required in order to avoid the problems which derive from variations in the location and configuration of the spray pattern. A practical example of this type of problem is a die casting operation where excess lubricant at the wrong location on a die surface can cause ripples, unevenness or texture variations in the resulting cast product. Even when the cams are properly set for a particular piston speed, a decrease in speed can result in excess lubricant spray due to the increased time interval between cam engagements. Furthermore, manual adjustment is dangerous since it is often accomplished while the operator is between the open platens.

Another disadvantage of prior art equipment is the complexity and size of the hydraulic cylinder operating system. Also, hydraulic fluid leakage can jeopardize the forming operation and reduce the repeatability of the spray initiation and configuration.

SUMMARY OF THE INVENTION It is among the objects of the invention to improve the accuracy and speed of the lubrication of or blowing an air blast on working surfaces of a die or mold between forming cycles.

Another object is to facilitate remote adjustment of the location, configuration and density of the spray pattern of a reciprocating lubricating device for molds and dies, after the die plates or mold plates have been changed.

A further object is to assure accuracy and uniformity during repeated cycling of a device for automatically spraying a lubricant on the working surfaces of a mold 0 die.

These and other objects are accomplished by an apparatus for driving the reciprocating fluid emission head or spray head through its variable speed, variable function operating cycle over the surface to which the spray is directed. The apparatus includes a pneumatic cylinder and piston, an operating rod connected between the piston and the fluid emission head or spray head, and fluid control means for driving the piston to extend and retract the operating rod at controlled speeds through an operating cycle. The cycle may include, during extension, at least one time interval of relativel fast travel and at least one time interval of relatively slow travel or no travel. A valve mechanism is used to cause the spraying of lubricant or other liquid from the spray head during the slow travel time interval depending on the particular application and one or more electronic RC timers operatively connected to the fluid control means are used to control the duration of the time intervals as well as the initiation thereof.

In the preferred embodiment the spray head is mounted on a manifold which includes other heads or nozzles for blowing an air blast against the forming surfaces during certain time intervals in order to remove flash and to assist in cooling.

Other objects, uses and advantages of the invention will appear from the following detailed description and drawings which illustrate a preferred embodiment of the invention.

BRIEF DESCRIPTION OF THE DRAWINGS FIGURE 1 is a perspective view showing a reciprocating device for automatically applying a liquid lubricant to forming surfaces, the device being shown as used in connection with a die casting unit;

FIGURE 2 is an elevational view showing in one part, the reciprocating apparatus of FIGURE 1 and in another part a control panel for the apparatus, interconnecting electrical lines being shown schematically;

FIGURE 3 is a cross sectional view of the reciprocating apparatus of FIGURES 1 and 2 with parts broken away for the purpose of illustration;

FIGURE 4 is a perspective view on an enlarged scale showing the manifold assembly of the reciprocating apparatus of FIGURES 1 and 2;

FIGURE 5 is a schematic diagram of the pneumatic system for the reciprocating apparatus of FIGURES 1 and 2; and

FIGURE 6 is a schematic diagram of the electrical control system for the pneumatic system of FIG. 5.

DESCRIPTION OF THE PREFERRED EMBODIMENT Referring more particularly to the drawings and especially to FIGURES l and 2 there is shown a reciprocating lubricant spraying apparatus A embodying the invention, mounted on a swivel mount B bolted to the stationary platen of a die casting machine C. The machine C comprises a stationary platen 10, a movable platen 11 and guide rods 12 which guide the movable platen 11 between its open position shown in FIGURE 1 and a closed casting position. Each platen and 11 supports one of two matched dies 13, only one of which is shown. Multiple cavities 14 are provided and connected by runners 15 to a sprue 16 through which the molten material to be castaluminum for eXampleis introduced into the die cavities.

The movable platen 11 is moved back and forth between its open and closed position by an operating mechanism (not shown) and the platens are generally opened for a sufiicient period of time during the casting cycle to remove the freshly cast product from the dies and also to apply a lubricant to the forming surfaces. Also it is desirable inmost instances to blow air against the dies at various locations to remove flash which may squeeze out of the runners and cavities along parting lines and also to cool parts of the die which are not effectively cooled by the integral circulating cooling system in the casting machine C.

The application of the lubricant to the die surfaces and also the blowing of the die surfaces is accomplished by means of the reciprocating spraying apparatus A which is supported by the swivel mount B on the fixed platen 10. The apparatus A includes an elongated channel 18 which is bolted to the swivel arms 19 and 20 of the mount B and which supports at its lower end a mounting block 21. Extending through the mounting block 21 are a stabilizer tube 22 and a pneumatic cylinder 23, the stabilizer tube 22 being guided for vertical travel by a roller thrust bearing 24 supported by the mounting block 21. The lower end of the stabilizer tube 22 supports one of several interchangeable spray manifolds 25 which may be quickly replaced when the dies 13 are changed, to suit different die configurations.

The upper end of the pneumatic cylinder 23 is pivotally connected by a hinge bracket 26 to the channel beam 18 and the lower end of the piston rod 27 extending from the cylinder 23 is connected to the spray manifold 25. The spray manifold 25 has three spray heads 28 which are adjustably mounted to provide a desired spray pattern, and air nozzles 29 which are also adjustable to direct an air blast at the desired part of the die plate 13 and also the opposed die plate on the moveable platen 11. The lubricant to be sprayed from the spray heads 28 is supplied through flexible liquid lines 30. Pressurized air which is used to discharge the liquid lubricant from the spray heads 28 in the form of a fine spray is supplied from the spray manifold 25 to the spray heads 28 by flexible air lines 31 While the air to be blown against the die plate 13 for cooling and removing flash is supplied through another set of flexible air lines 32.

Air for spraying is supplied to the spray manifold 25 through a rigid feed tube 33 which extends through the stabilizer tube 22 and the liquid lubricant is supplied through a rigid feed tube 34 also extending through the stabilizer tube 22 (FIGURE 3). Air for blowing is supplied through the stabilizer tube itself. The supplies of spraying air, liquid lubricant and blowing air are con trolled by solenoid valves 36, 36b and 37 respectively.

PNEUMATIC DRIVE SYSTEM Air pressure for operating the pneumatic cylinder 23 is supplied to the upper end thereof by an upper cylinder air line 38 and to the lower end by a lower cylinder air line 39 (FIGURE 2). The speed of travel of the piston is controlled by low-speed restricter valves 40 and 41 (FIGURE 5) connected to the upper and lower cylinder air lines 38 and 39, respectively, and by high-speed restricter valves 42 and 43, respectively. The high speed or low speed selection is controlled by by-pass valves 44 and 45 which, depending upon their position, determine whether or not the fluid being exhausted from the upper or lower end of the cylinder during the retract and extend strokes, respectively, will be routed through both high-speed and low-speed restricter valves or only through the high-speed restricter valves 42 and 43.

During the extension stroke of the piston rod 27 the pressurized air is supplied through an extend valve 46 whereas during the retraction stroke pressurized air is supplied through the retract valve 47. The air pressure is controlled and may be varied by means of an extend pressure regulator 48 and a retract pressure regulator 49.

The pressure for the spray air is regulated by a pressure regulator 50.

The pneumatic system is also used to operate the mechanical safety uplock 51 (FIGURE 2) that locks the piston and piston rod 27 in the upward or retracted position between spraying cycles to prevent accidental extension of the manifold 25 during the die casting operation, which could result in serious damage.

The air pressure system is also used to pressurize a tank 52 of liquid lubricant from which the lubricant is supplied to the spray manifold 25. An air pressure safety valve 53 releases excessive air pressure While an air pressure regulator 54 controls the pressure of the liquid supplied for spraying.

ELECTRICAL CONTROL SYSTEM The valves for controlling the operation of the pneumatic cylinder 23 and the valves 36, 36b and 37 for spray air, liquid lubricant and blow air respectively are all solenoid operated and controlled by the electrical control circuit shown in simplified form in FIGURE 6. The control panel 57 for the system is shown in FIGURE 2. The circuit includes for the purpose of illustration, seven adjustable electronic RC-type timers of high precision and accuracy which provide for eight separate controlled time intervals during the extension and retraction cycle of the apparatus A. Electronic timers identified by the trade designation 1042 SGO (single unit) and 1042 DGGO (double unit), manufactured and sold by Industrial Solid State Controls, Inc. of York, Pa., have been found to be particularly suitable. For the purpose of illustration, 2. four stage cycle will be described with blowing only du ing extension and spraying only during retraction.

1st time interval The control circuit of FIGURE 6 is energized by an off-on switch 58 and the cycle is manually actuated by pressing the push button start switch 59, provided the platens 10 and 11 of the die casting machine C or other forming unit are open to close a limit switch 60 (FIGURE 1). Limit switch 60 serves as a safety device to prevent operation of the apparatus A when the platens are closed or in motion. When start switch 59 is depressed, timer 61 is actuated and remains energized for a controlled time interval during which relay 62 is also energized. The time interval may be adjusted by timer rheostat 61b (FIGURE 2). Relay 62 closes relay contacts 62a to energize holding relay 63. This in turn closes relay contacts 63a and 63b, contacts 63a serving to keep relay 63 energized even after contacts 62a open, and contacts 63b serving to energize solenoids 46a and 47a. Solenoid 46a opens solenoid valve 46 (normally closed) to supply air under pressure to the upper end of the pneumatic cylinder 23 and solenoid 47a closes solenoid valve 47 (normally open) so that air from the lower end of the pneumatic cylinder 23 is exhausted through the high speed and/ or low speed restricter valves 41 and 43 respectively. As soon as the piston begins its downward movement, limit switch 65 closes to energize relay 66, whereupon relay contacts 66a close to energize holding relay 67 and contacts 66b (normally closed) open. When relay contacts 67a (normally closed) open, the circuit through relay 63 is complete through another pair of relay contacts 72a (normally closed), described below. Relay contacts 67b keep relay 67 energized after relay contacts 66a open at the completion of the retraction stroke. When the timer 61 times out, timer contacts 61a close to energize timer 64 and relay 62 is de-energized.

2nd time interval During the second time interval which can be adjusted by timer rheostat 64b, relay 69 is energized and relay contacts 69a and 6% close to energize solenoids 37a and 44a. Solenoid 44a closes by-pass valve 44 (normally open) to route exhaust air through the slow-speed restricter valve 41 and limit the piston to a relatively slow speed or to cause it to stop. Solenoid 37a opens air valve 37 to release blowing air from the air nozzles 29. When timer 64 times out, relay 69 is de-energized as are solenoids 37a and 44a, and timer contacts 640 close to energize timer 68.

3rd time interval During the third time interval which can be adjusted by timer rheostat 68b, slow speed restricter valve 41 is bypassed and the piston extends at a relatively fast rate of travel. When timer 68 times out, timer contacts 68a close to energize timer 70.

4th time interval During the fourth time interval which can be adjusted by timer rheostat 70b, relay 69 is again energized to close contacts 69a and 69b and energize solenoids 37a and 47a to provide the same slow speed and blow function as in the second time interval. When timer 70 times out, relay 69 is de-energized as are solenoids 37a and 44a and timer relay contacts 70a close to energize timer 71 and relay 72.

5 th time interval Relay 72 opens relay switch contacts 72a (normally closed) to break the circuit to relay 63 whereupon switch contacts 63b open to de-energize solenoids 46a and 47a and reverse the positions of solenoid valves 46 and 47, thus initiating the retraction stroke of the piston. At the same time relay contacts 72b close to energize solenoid 45a and close by-pass valve 45. This routes exhaust air through the retraction slow-speed restricter valve 44 which either reduces the speed of the piston or causes it to stop. At the same time relay contacts 720 close to energize solenoids 36a and 36c and open solenoid valves 36 and 36b to provide a spray of lubricant. The duration of the 5th time interval may be adjusted using rheostat 71b (FIGURE 2). When timer 71 times out, relay 72 is deenergized as are solenoids 36a, 36c and 45a, and timer contacts 71a close to energize timer 73.

6th time interval During the 6th time interval which may be adjusted by timer rheostat 73b, slow speed restricter valve 44 is bypassed through the valve 45 and the piston proceeds at a relatively fast retraction speed controlled by high speed restricter valve 42. After timer 73 times out timer relay contacts 73a are closed to energize timer 74.

7th time interval When timer 74 is energized, relay 72 is again energized to close relay contacts 72b and 72c and energize solenoids 36a, 36c and 45a. This closes bypass valve 45 to route exhaust air through low speed restricter valve 44 to provide a slow retraction speed (or stop), and opens valves 36 and 36b to provide a lubricant spray, as in the 5th time interval. The duration of the seventh time interval is controlled by timer rheostat 74b.

8th time interval After timer 74 times out relay 72 is de-energized and relay contacts 72b and 720 open to de-energize solenoids 36a, 36a and 45a. Accordingly restricter valve 44 is bypassed through valve 45 and the piston completes its retraction stroke at a relatively fast speed. When the piston reaches its retracted position, limit switch 65 (FIGURES 2 and 3) is opened to de-energize relay 66, open relay contacts 66a and close relay contacts 66b to energize time delay relay '75. Relay 67 remains energized until time delay relay 75 times out to open contacts 751:. At the same time another pair of contacts (not shown) of the time delay relay 75 close to actuate the control system of the die casting machine. When the platens 10 and 11 begin their closing movement, limit switch 60 open to de-energize the control circuit.

A two position selector switch 76 may be used to eliminate one slow speed time interval during both extension and retraction by by-passing timers 64, 68, 70 and 73. Also the operation may be varied by pressing the manual spray switch button 77 which energizes solenoids 36a and 360 any time during the extension-retraction cycle.

The function during the second, fourth, fifth and seventh time intervals may also be varied by means of the three position selector switch 78 to provide spraying during the second and fourth time intervals and blowing during the fifth and seventh time intervals or spraying only during all four time intervals. Other variations may also be provided merely by changing the switching arrangement. Also the cycle may be interrupted at any time by the machine operator by pressing the emergency stop button 79. When this happens all solenoids will be de-energized and the piston will return to its retracted position at a relatively fast rate of travel.

Panel lights 80 serve to indicate to the machine operator the particular timer which is energized during the cycle.

OPERATION The spraying and blowing operation of the apparatus A i initiated manually by the die casting machine operator by depressing the push button start switch 59 when the platens 10 and 11 reach their open position following the forming and removal of the cast product. Normally the cast product will have been removed from the die cavities by extractor pins during the opening movement of the movable platen 11. As indicated above the apparatus A 7 will not cycle until the platens are opened far enough to close limit switch 60.

When the circuit is energized, the timers begin to sequence the various control valves according to the positioning of selector switches 76 and 78-. Selector switch 76 can be set to provide either a two-stage or four-stage cycle depending upon the particular dies being used. The fourstage position provides for two slow speed or stop time intervals during both extension and retraction as indicated above in the description of the electrical control circuit, whereas the two-stage position provides for only one slow speed or stop time interval during both extension and retraction. The three position selector switch 78 may be used to select the function for each of the slow speed or stop time intervals as shown schematically in F1"- URE 6 and as described above with respect to the electrical control circuit.

Most importantly, the duration of each of the various time intervals may be very accurately and precisely preset on the control panel 57 using the timer rheostats 61b, 64b, 68b, 70b, 71b, 73b, and 74!), thereby enabling the die casting machine operator to quickly and accurately control the precise location and configuration of the resulting lubricant spray pattern. Because the duration of the intervals during which lubricant is being sprayed depends upon time measurement alone (i.e. RC timers), the quantity of lubricant applied to the die can be accurately controlled and uniformly repeated during each cycle; whereas where the lubricant spray is controlled by the spacing between cams, the quantity of lubricant applied depends upon the speed of travel of the piston between cam engagements, which is subject to transient variations.

With this arrangement the machine operator or set-up man may cycle the apparatus A a few times after a new set of dies has been mounted on the platens 1t and 11, and in so doing determine the timer rheostat setting which will properly position and move the spray heads during the slow speed or stop time intervals which in the case of a four-stage cycle are the second, fourth, fifth and seventh time intervals. This can be done of course with the operator standing at the control panel and without any need for an operator or set up man to position himself between the platens and adjust cams or other mechanical structure.

Once the operator has determined the proper rheostat settings for spraying or blowing a particular set of dies he need merely record the settings so that the next time the particular dies are used he can immediately and quickly preset the apparatus A for the desired spray location and configuration using the timer rheostats on the panel 57.

The particular application of the automatic spraying device illustrated here relates to die casting, however, there are many other types of forming apparatus with which the device can be used and the advantages thereof realized. Such other applications include but are not limited to forging, drawing, molding and stamping. Also the device may be mounted for horizontal reciprocating movement if desired or it may be carried on a mobile stand.

While the invention has been illustrated and described with respect to a specific embodiment, it will be understood that variations and modifications may be made in the form and arrangement of the several parts and elements thereof without departing from the spirit of the invention. The invention therefore is not to be limited to the particular strucure and mechanism herein shown and described nor in any manner inconsistent with the extent to which the progress and the art has been advanced by the invention.

What is claimed is:

1. Apparatus for driving a reciprocating fluid emission head through a variable-speed, variable-function, operating cycle over a surface toward which fluid is to be selectively emitted, comprising a pneumatic cylinder and piston, an operating rod connected between said piston and said emission head, fluid control means for driving said piston to extend and retract said operating rod at controlled speed through an operating cycle, valve means for discharging fluid from said emission head during a selected period in said operating cycle and adjust-able electronic timing means operatively connected to said fluid control means for controlling the time of initiation of said selected period and the duration thereof independently of the position of said emission head.

2. Apparatus as defined in claim 1 wherein said operating cycle includes, during both extension and retraction, at least one time interval of fast travel and at least one time interval of travel between full stop and relatively slow speed, the time of initiation and duration of said time intervals being controlled by said adjustable electronic timing means.

3. Apparatus as defined in claim 2 wherein two of said fast travel time intervals and two of said time intervals of travel between full stop and slow speed are included during both extension and retraction.

4. Apparatus as defined in claim 1 wherein said adjustable electronic timing means comprises variable resistance, RC timers interconnected for sequential operation.

5. In an apparatus for driving a liquid lubricant spray head through a variable-speed, variable-function, operating cycle over a surface toward which lubricant is to be selectively sprayed and which includes a pneumatic cylinder and piston operatively connected to said spray head, a solenoid operated pneumatic control system 0peratively associated with said piston to extend and retract said spray head at controlled speeds through an operating cycle and solenoid operated valves for discharging lubricant from said spray head, the improvement which comprises electronic, variable resistance, RC timers operatively connected to said pneumatic control system solenoids and to said lubricant discharge valve solenoids, said timers being adapted to operate successively, each actuating the next successive timer after timing out its present interval, certain of said timers being adapted to actuate certain of said solenoids during their time intervals to provide a predetermined speed and a predetermined function for said spray head during the interval of each timer.

6. Apparatus as defined in claim 5 including four RC timers operable during the extend stroke of said piston and three RC timers operable during the retract stroke of said piston, two of said extend stroke timers, alternately arranged and two of said retract stroke timers alternately arranged, being operable during their respective intervals to energize an air valve solenoid to route exhaust air from said cylinder through a slow speed restricter valve and to energize at least one fluid emission control valve solenoid to spray one or both of lubricant and air.

7. Apparatus for cleaning and lubricating dies comprising a spray head adapted for reciprocating travel during which said spray head is positioned for blowing an air blast at a die and for spraying a liquid lubricant thereon, a pneumatic cylinder and piston operatively connected to said spray head, a pneumatic pressure source, solenoid operated pneumatic control valves operatively associated with said cylinder and said pressure source to extend and retract said piston and said spray head at controlled speeds through a variable speed operating cycle, solenoid operated valves operatively associated with said pressure source for discharging an air blast and liquid lubricant from said spray head, electronic, variable resistance, RC timers operatively connected to the solenoids of said pneumatic control valves and to said air and lubricant discharge valve solenoids, said timers being adapted to operate successively, each actuating the next successive timer after timing cut its preset interval, certain of said timers being adapted to actuate certain of said solenoids during their time intervals to provide a predetermined 9 10 speed and a predetermined function for said spray head FOREIGN PATENTS during the interval of each timer. 571 44 9 1945 Great Britain 833,819 4/1960 Great Britain.

References Cited r FRED C. MATT ERN, 111., Primary Examiner UNITED STATES PATENTS MANUEL A. ANTONAKAS, Assistant Examiner 3,031,033 4/1962 Burrows 18415 CL 3,073,415 1/1963 DuttOn et a1 184-15 184-6

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