DE2415105A1 - CORE DRILLING MACHINE FOR FLAT GLASS - Google Patents

Description

£ 2 .. March 1974 SC-1123 Patent Attorneys:
Dr. Ing.Walter Abta

_Dr. Dieter F. Mprf.

Dr. Hans-A. Browns

8 Munich 86, 'Päenzenaueratr. 28

ENGELHARD MINERALS & CHEMICALS CORPORATION 4j5O Mountain Avenue, Murray Hill, New Jersey 07974, V.St.A,

Core drilling machine for flat glass

The present invention relates to drilling flat glass and glass-like material using, for example core drills set with diamond grains and the like. In particular, the invention relates to a fluid operated one System for moving a pair of opposing coaxial drilling tools back and forth. while their respective alternating operating cycles, and in particular the control of the fluid operated system for accurate Adjustment of the cutting depth. The invention is particularly advantageous in connection with drilling holes in lighting for automobile doors, as is the case with door window glass required for many current American automobile models, and likewise in connection with lighting for atrium doors and the like.

When drilling holes in flat glass and other hard, refractory materials, it is necessary to use extremely hard ones Use cutting materials. For this purpose, diamond core drills are most often used (in which Industrial diamond grains arranged in a ring-shaped matrix

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are embedded, which mostly consists of molten powder metal). To avoid splitting or breaking the glass, which would normally occur at the edge of the hole in the glass surface where the drill emerges, it is more appropriate to partially drill the hole from one side of the flat glass and the remainder of the hole from the other side, thereby removing the core. At. This procedure is followed by the final Breakthrough between the surfaces of the glass and fragmentation of the glass surface is avoided.

Usually two cooperating , coaxially arranged core drills are used which alternately penetrate opposite sides of the glass. The flat glass is firmly clamped in the machine and cooling water is supplied to the area in the vicinity of the surface to be cut. It is necessary that there is precise control of the cutting depth of the core drill to ensure that the drilling operation is stopped at the correct depth from at least one side '.

Known machines used for this purpose usually used a constant pressure system, for example a fluid pressure system to achieve the advance the drill in the glass. The respective drills are usually connected to the actuating element of the fluid cylinder connected and are thereby during an operating cycle reciprocated by the cylinder piston assembly. The depth of cut is usually determined by mechanical stops and controlled electrical switches which are in communication with solenoid valves of the control system.

This arrangement requires time-consuming manual settings, insofar as these are necessary, and also laborious readjustments to the machine for drilling flat glass different thickness.

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Adjustment of the switch actuators or stops must be done and required with reasonable accuracy So far, a considerable amount of time spent on hiring and re-hiring to get satisfactory results to obtain. The cooling water supplied to the cutting area was sprayed around the lower part of the machine and often shorted the electrical switches, corroded the contacts, or in some other way to an unreliable operation of the switch.

In many cases, the type of processed flat glass and thus the thickness of the glass is changed frequently, and at every change the switch mechanism must be set by hand and adjusted by trial and error to the cutting depth for the dimensions of a respective flat glass. Furthermore, with increasing wear of the drill the switch mechanism and / or the stops are periodically readjusted to ensure the desired cutting depth.

Another method for drilling flat glass is insofar as the operating system is for the reciprocating motion Drills are affected by their respective work cycles, in that a constant feed rate for the drill to use instead of constant pressure. When drilling with constant pressure, the drilling process proceeds at one speed which depends on various factors, such as the properties of the material being drilled, while the Constant feed drilling an excess pressure is used, but constant speed drilling is independent of the load acting on the drill progresses, assuming of course that the pressure is sufficient to overcome all load resistances.

The advantages of constant feed drilling are longer drill life and a reduction in Distances at which it is necessary to sharpen the drill.

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A general description of constant feed drilling is given in an article entitled "An Improved Method for diamond core drilling of automotive glass "in the periodical publication" Industrial Diamond Review "dated Given May 1969. Another description of drilling constant feed is contained in US Pat. No. 3,710,516 to Joseph B. Kelly. This patent brings a detailed discussion of the benefits obtained by moving the core bit at constant speed will.

The present invention relates to an improvement in the control of the fluid operated feed system for a machine of the general type in accordance with the aforementioned patent specification and has further features and advantages, which were previously not available.

The invention is based on the object with increased accuracy to control the cutting depth of a drill, which in flat glass or in glass-like material with constant Speed is moved.

Another object of the invention is the setting time to shorten what is required for setting the machine for drilling glass and glass-like material is to process flat glass with different dimensions.

Another object of the invention is to use electrical switches to control drill feed in flat glass and glass-like material.

Another object of the invention is to shorten the duration of the drilling process when core drilling flat glass, by moving the drill at a relatively high speed

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is moved to a position immediately in front of the glass surface, whereupon a feed movement is relatively low speed through the glass to the desired cutting depth.

These and other tasks are accomplished by means of a new fluid pressure system solved, which the control device according to the invention in connection with a flat glass core drilling machine the version described contains. In accordance with the present invention is for either of the two opposing coaxial drilling tools of the machine a fluid cylinder with piston provided, which with the drilling tool is in working connection. Each drilling tool is advanced and retracted by a fluid pressure system, which is in operative connection with the respective cylinder to the drilling tool in a time interval to bring with fast feed at constant feed speed into a position that is in front of a small distance the surface of the material to be drilled, and it in a time interval with slow feed at constant speed from the point of contact of the drilling tool with the surface of the material up to a specified depth of cut respectively. The distance covered during each time interval is precisely determined by adjustable timing relay arrangements controlled, which are in operative connection with the fluid pressure system, to the duration of the time intervals of the set constant feed rates. Thus, the timing relay arrangements are used to control the positions of the drilling tool at the beginning and at the end of the time interval for slow feed in order to adjust the cutting depth in Control flat glass.

The timing relay arrangements preferably contain a dedicated electronic timing relay for each time interval. Appropriately each time relay consists of a digital one

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Time relay, which allows setting in very small time steps, in order to achieve optimum control accuracy and to enable adjustment of the cutting depth and, in particular, an adjustment for the increasing wear of the drilling tool.

In the drawings show: "

FIG. 1 shows a side view of a core drilling machine for flat glass according to the present invention, with FIG For a better representation parts are broken away or shown in section,

Figure 2 is a front view of the machine according to Figure 1,

FIG. 5 shows a partial section on a larger scale along the Line 3-3 of Figure 2,

FIG. 4 shows a partial section along the line. 4-4 of Figure J>,

FIG. 5 is a fragmentary front view taken along line 5-5 of FIG Figure 2,

FIG. 6 shows a sectional view on a larger scale along the line 6-6 in FIG. 1,

FIG. 7 is a longitudinal sectional view on a larger scale the line 7-7 of Figure 1, and

Figures 8, 9 and 10 are schematic representations, which successively the fluid pressure system and associated control devices according to the invention in their operating conditions show during successive stages of operation.

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Reference is first made to Figures 1 and 2, in which a core drilling machine for flat glass is shown, which has a fluid pressure system which has an inventive Has control device. The machine has an upper spindle assembly A and a lower spindle assembly B, which alternate vertically towards and from one another during a core drilling process can be moved away. The machine picks up a horizontally lying sheet glass, which during the The drilling process is held in place by a clamping arrangement C. In the illustrated embodiment, the machine Drill a hole at a predetermined point in a flat glass 10, which is intended for an automobile door lighting desired shape is tailored.

The machine is set up on a stone bed plate 11, which normally rests against a stone surface. the The position of the bed plate can be easily adjusted by means of a water pressure system, with water in a narrow one Recess in the bottom surface of the bed plate is introduced via vertical channels to support the weight of the machine to compensate and to facilitate the adjustment of the machine on the base plate. Then the water withdrawn from the recess and applied a vacuum through the same vertical channels to keep the machine in the to anchor the desired position. A holding frame 12 is anchored to the bed plate 11 by means of bolts. The upper and lower spindle assemblies A and B are alternately toward and away from each other for vertical movement in upper and lower dovetail guides 13 and 14 stored, which are each attached to the frame 12. The forward and backward movement of the spindle assemblies A and B. takes place by means of hydraulic drive cylinders 15 or 16, which are each attached to the top of the frame 12, and which are operated by a fluid pressure system, which

is best shown in Figures 8, 9 and 10. the Cylinders 15 and 16 are both located in the upper section of the machine, where they are as far away from the water spray as possible removed, which is used to lubricate the drill

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The piston rod for the drive cylinder 15 is direct connected to the upper spindle assembly B, while the piston rod for the drive cylinder 16 with a vertical Intermediate rod 17 is connected, which is attached at its lower end to one end of a pivot arm 18. The swivel arm 18 is attached in its central portion to the frame 12 for pivoting movement about a horizontal axis. That other end of the pivot arm 18 is connected to a vertical intermediate rod 19, which in turn at its upper End pivotally attached to the lower spindle assembly B (Figure l).

The clamping device C is shown most clearly in FIGS. J5, 4 and 5 and has a horizontal table 20 which is fastened to the frame 12 and a clamping lever 21. The table 20 serves to receive the flat glass 10 and is provided with a hole 22 for the drill of the lower spindle assembly B. The clamping lever 21 is arranged above the table 20 and is pivotably attached to brackets 2J on the frame 12. A clamping jaw 24 has an opening 25 for receiving the drill of the upper spindle arrangement A and is pivotably connected to the forked outer end of the clamping lever 21. The clamping jaw 24 is moved toward and away from the table by the clamping lever 21 in order to grasp the flat glass 10 in the vicinity of the hole to be drilled. The clamping lever 21 is pivotably connected at its opposite or inner end to an intermediate rod 2.6 which is fastened to the piston of a clamping cylinder 27.

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Spindle arrangements

The spindle assemblies A and B are essentially the same and are therefore only described in connection with the upper spindle assembly A. Same reference numbers are used in conjunction with corresponding parts of the lower spindle assembly B.

The spindle assembly A has a platform Jl on whose a slide 32 is welded to the outer end (FIGS. 1, 2 and 6) is. The carriage is guided in the vertical direction in a dovetail guide 13 and is through the drive cylinder 15 reciprocates. The piston of the cylinder 15 is attached to a connecting element which in turn is pivotally connected to the upper portion of the carriage. The carriage 32 carries a spindle 33 with it a putter 3 ^ · for receiving a core drill 35 · the upper one End of the spindle 33 has a pulley 36 which is driven by a V-shaped belt 37 which is guided around the drive pulley 38 of an electric motor 39. The motor is adjustable on the platform 31 in the one shown Way, attaches and turns the core drill 35 at about 3IOO revolutions per minute.

In order to compensate for the weight of the motor, an air compensation cylinder kO is arranged at the rear end of the platform 3I. Water for lubricating the core drill 35 is supplied through a flexible water pipe (not shown) which is connected to a rotary joint which is connected to the spindle 33.

Fluid pressure system

The fluid pressure system for operating the drive cylinder 15 and 16 and the associated control devices are best seen in FIGS. 8, 9 and 10. The systems are

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with respect to the upper and lower spindle arrangement A and B are identical and are therefore only in connection with the upper spindle assembly A and its associated drive cylinder 15 is described.

Fluid pressure is obtained by means of a constant pressure pump 50 which draws fluid from a reservoir 51 - pumps and working fluid under pressure via line 52 the head end of the drive cylinder 15 supplies. The pressure supply via line 52 is by means of a four-way solenoid valve 55 controlled, which with the piston extended in Figures 8 and 9 and with the piston retracted in Figure 10 is shown.

By means of a conduit 54 with a pair of parallel branch conduits 55 and 56, fluid is supplied to the end of the drive cylinder I5 on the piston rod side or is withdrawn therefrom. The branch line 56 has a two-way solenoid valve 57 which is shown in Figures 8 and 10 in its open position and in Figure 9 in its closed position is. The branch line 56 also has a check valve 58 designed as a ball valve and is through a Querleitüng 59 with the branch line 55 between the check valve 58 and the two-way valve 57 connected. '

The branch line 55 contains a pressure and temperature compensated, adjustable flow restrictor 60 (or flow control device), which is between the drive cylinder I5 and the cross line 59 is arranged, as well as another similar adjustable flow throttle 6l, which is between the Four-way valve 55 and the cross line 59 is located. The two-way valve 57 is shown in FIGS. 8 and 10 in its open position. According to FIG. 8, this comes from the piston rod side Fluid exiting at the end of cylinder I5 bypassing flow restrictor 60 through the two-way valve 57 and then flows through the flow throttle 6l,

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since the check valve 58 is in its closed position. This operating state enables one relatively fast feed at constant speed. The two-way valve 57 is located according to FIG. 9 in its closed position, it comes from the piston rod side Fluid exiting at the end of the drive cylinder 15 through both flow restrictors 6O and 6l. This operating state enables a relatively slow advance at constant speed, for example 1.5 mm (0.06 inches) per second.

The four-way valve 53 is in its position in FIG. 10 shown retracted position, the fluid pressure is via line 54 to the piston rod end of the drive cylinder 15 headed. In this position, the two-way valve 57 is in the open position and the flow arrives through the branch line 56, since the check valve 58 is in its open position, so that the supplied Fluid pressure can bypass both flow restrictors 60 and 6l.

The solenoid 53a of the four-way valve 53 and the solenoid 57a of the two-way valve 57 are operated by electronic timing relays 65 and 66, respectively. In the described embodiment, the timing relays 65 and 66 are solid state circuit electronic timing relays having a digital output and push button setting such as those available from Automatic Timing and Controls, Inc., 203 S. Gulph Rd., King of Prussia, Pennsylvania at under the trade name 335 A35 IAl OPX. These timing relays are adjustable in steps and the digital output allows for quick push button setting and adjustment by an operator.

Operating mode

The mode of operation of the machine with the fluid pressure system

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connected control device is described in connection with Figures 8, 9 and 10, which are sequentially indicate a cycle of operation for the upper spindle assembly A. As mentioned earlier, the systems are essentially identical with respect to the upper spindle assembly A and the lower spindle assembly B and are therefore used solely in connection with the upper spindle assembly A described.

In Figure 8, the initial phase of the operating cycle is shown, in which the upper spindle assembly A with a relatively fast advance at a constant speed is brought to a position which is a short distance, for example 0.8 mm (1/32 inch) in front of the surface of the flat glass 10 lies (but is not in contact with the glass). In this area of the work cycle, a faster feed to reduce the duration of the drilling process to a minimum. In this operating state the system has been turned on by an operator and the timer switch 65a is closed to the solenoid 65a with power so that the four-way valve 53 is in its normal position, i. H. in the Drawing is moved to the right. Accordingly, fluid pressure is the head-side end of the drive cylinder 15 via the Line 52 supplied. The timing relay 65 is switched on and expires during a predetermined time interval.

The time relay switch 66 is open, the solenoid 57a is switched off and the two-way valve 57 is in its open position, so that fluid discharged from the end of the drive cylinder 15 on the piston rod side bypasses the flow throttle 60 and is only detected by the flow throttle 61. Since only one of the two flow restrictors is located in the outlet line, a constant advancing speed is obtained, but the piston movement is comparatively fast. The timer relay 66 is switched on, and that

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The time interval with rapid advance continues until the timing relay 66 has expired and the timing relay switch 66a closes and the solenoid 57a switches off. The time interval for rapid advance is thus determined by the setting of the time relay 66 . -

Referring to FIG · 9 can be seen that the solenoid ^a is turned on at the expiration of timer 66 57, and the valve moves to its closed position 57 so that the rod end of the cylinder 15, fluid discharged both through the flow restrictor 6o as well as is passed through the flow throttle 6l to allow increased control of the flow. In this operating state, a slow feed rate is obtained for the upper spindle arrangement A, and this time interval lasts as long as pressure is supplied to the head-side end of the cylinder 15. During this time interval, the drill 35 moves to rest against the glass or . in cutting movement on the glass and is guided at a constant speed to a predetermined depth of cut. This time interval with a slow constant feed rate lasts until the time relay 65 has expired and the solenoid 53a switches off. It is assumed that the flow throttle 60 for a slow feed rate of 1.5 mm (0.06 inches) per second is set and the time relay 65 is adjustable in steps of 0.01 seconds, the cutting depth can be preselected in steps of 0.15 mm (Ο, ΟΟβ inch).

FIG. 10 shows the operating state of the system during the backward movement of the upper spindle arrangement A, which can be seen is that the timer relay 65 has expired and the switch 65a has opened to the solenoid 53a switch off.

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As a result, the four-way valve 53 has moved to the left or to its other position. In this position pressure is applied to the end of the drive cylinder 15 on the piston rod side via the line 54 by means of the pump 50 fed. Both flow restrictors 60 and 61 are bypassed, since the line 56 via the check valve 58 and the two-way valve 57 is open. The reverse movement continues until the upper spindle assembly A is completely in its in Figure 8 is returned to the initial position shown.

The lower spindle assembly B goes through its operating cycle preferably before the upper spindle assembly A, and this cycle of operation is identical to the previous one in connection with the fluid pressure system for the upper spindle assembly A cycle described. After the second operating cycle of the upper spindle assembly A has ended, the cutting process of the two drills has been completed and the core is ejected. Finally, the clamping arrangement C released and the flat glass 10 removed from the machine by the operator.

The release of the glass by the clamping arrangement C is preferably carried out by a follow-up time relay, not shown controlled, which is turned on by the operator when he presses a start button. The start button switches also a solenoid valve which actuates the clamping cylinder so that the clamping jaw 24 against the flat glass Table 20 presses. The initial clamping pressure is relatively high in order to counteract any forces that may be exerted by the Core drill 35 of the lower spindle assembly B against the glass be exercised when the drill penetrates the glass from below. After the lower spindle assembly B has finished its cutting process has ended, the clamping pressure supplied by the clamping cylinder 27 can, depending on the follow-up time relay, on a nominal value will be reduced as the. Force exerted against the glass by the core drill of the upper spindle assembly A

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is received by the table 20 which is rigidly supported by the frame.

With the control device according to the invention, the cutting depth can be controlled very precisely - for example in 0il5 mm (0.006 inch) increments, and it is during of each operating cycle evenly reproducible. Further, the starting point of the slow feed time interval can be set according to the glass thickness using the Timing relay 66 can be precisely determined.

To prepare the machine for the first drilling process with a certain glass thickness, the operator can if so desired, try to determine the depth of cut by simply pushing the buttons on the respective. Timers are pressed to increase or decrease a previous digital output in steps of 0.01 seconds to decrease. As already mentioned, this causes changes in depth of approximately 0.15 mm (0.006 inches) with the feed rate 1.5 mm (0.06 inches) per Second. The slow feed rate can be changed by adjusting the flow restrictors 60 and 6l will. For example, the feed rates can be set between the limits of 0.51 mm (0.02 inches) per second change up to 12.7 mm (0.5 inch) per second within a tolerance of + 0.025 mm (0.001 inch). The steps the time adjustment, for example 0.25 mm (0.01 inches), are thus directly dependent on the speed converted into distance levels.

As soon as the adjuster has set the correct time settings for a particular production, all he needs is record the settings so that if the same production is repeated, the timing relays 65 and 66 immediately and can be set without delay. However, the wear and tear on the drill must be taken into account.

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Obviously, further modifications of the invention are possible and these are within the scope of the attached Claims of the invention, not covered.

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Claims (10)

SC-1123 claims 1. A device for moving a drilling tool through an operating cycle of a reciprocating movement, which comprises an interval of a drilling process in a flat glass or glass-like material, characterized by a fluid cylinder (15, 16), a piston arranged in the fluid cylinder, which with the drilling tool (35) is in operative connection, a fluid pressure device (5O-61) which is connected to the fluid cylinder in order to guide the drilling tool in a time interval of rapid feed movement at constant speed to a position which is adjacent to the surface of the flat glass, and furthermore to bring in a time interval with slow feed at constant speed from the contact of the drilling tool with the surface of the flat glass to a predetermined depth of cut in the flat glass, with adjustable time relay arrangements (65, 66) which are in operative connection with the fluid pressure device to the duration of the Time interval le to control with constant feed speed in order to control the positions of the drilling tool at the beginning and at the end of the time interval with slow feed for the purpose of controlling the cutting depth in the flat glass. 2. Device according to claim 1, characterized in that the fluid pressure device has a first flow throttle (60) as well as a second flow throttle (6l) and a valve device (53 * 57 * 58) to choose from Has connection only one of the flow throttles in the throttling position with the drive cylinder to • 409841/0812 SC-1123 to control the flow velocity of the fluid and to generate the said rapid advance, and to optionally connect both flow restrictors to the drive cylinder for the purpose of flow limitation, to control the flow rate and generate the slow feed rate. 3. Device according to claim 2, characterized in that that the valve device has two solenoid valves. 4. Apparatus according to claim J>, characterized in that the solenoid coils of the solenoid valves are actuated by the timing relay arrangements. 5. Apparatus according to claim 1, characterized in that that the adjustable timing relay arrangements have two electronic timing relays. 6. Apparatus according to claim 5 * characterized in that that the timing relays have a digital output. 7 · Device for drilling holes in flat glass or glass-like material, with a pair of each other oppositely arranged, cooperating coaxial drilling tools on opposite sides 'of the flat glass and are alternately pushed into the glass over about half the thickness of the glass can, characterized by a device for driving the drilling tools during alternating operating cycles a reciprocating feed movement, with each operating cycle a time interval of a drilling movement in the flat glass, and the device for each drilling tool includes a fluid cylinder with a piston arranged in this cylinder, which is in operative connection with the drilling tool 409841/0812 a fluid control device associated with the fluid cylinder is in operative connection to the drilling tool in a time interval with rapid feed and at constant speed to a position near the surface of the flat glass and in a further time interval with slow advance and constant speed from the contact of the drilling tool with the surface of the flat glass in a predetermined depth of cut in the glass bring, and with adjustable timing relay assemblies connected to the fluid control device, to control the duration of the mentioned time intervals with constant feed speed and on this way the position of the drilling tool at the beginning and at the end of the time interval with slow feed to control the depth of cut in the flat glass. 8. Device according to claim 7. » characterized, that the axis of the drilling tool is arranged vertically, and the drilling tools an upper drilling tool and a lower drilling tool. 9 · Device according to claim 8, characterized by a Device for clamping the flat glass in a horizontal position between the drilling tools Position, the device having a horizontal table and a clamping jaw that extends above the Table is arranged and is movable towards and away from the table, and with a fluid pressure device, which is connected to the clamping jaw in order to move it and a clamping pressure on the flat glass exercise. 10. The device according to claim 9 *, characterized in that A098A1 / 0812 - 19 - that the fluid pressure device has a control device in order to achieve a comparatively high level during the drilling movement of the lower drilling tool
To exert clamping pressure, and to exert a relatively low clamping pressure during the drilling movement of the upper drilling tool. 409841/0812