JPH0340655B2 - - Google Patents

Description

[Detailed Description of the Invention] [Industrial Application Field] The present invention revolves a plurality of mold opening/closing units holding molds on a rotary table, and a plurality of mold opening/closing units that hold molds are rotated at equal intervals on the orbit. This invention relates to rotation control of a rotary table in a rotary die casting machine that performs casting operations in the order of steps at a work station.

[Prior Art] Previously, the applicant developed a rotary die-casting machine with the aim of significantly improving productivity. This is achieved by installing mold opening/closing units that hold molds at positions that divide the outer circumference of the rotary table into multiple parts in the circumferential direction. Each work is performed in the order of steps while stopping at each work station.

To give an overview of the entire rotary die-casting machine, the rotary die-casting machine 1 has a first station ₂ , a second station 3, and the angles formed by the center lines indicated by symbols L ₁ , L ₂ , and L 3 in FIG. 9 are 120 degrees, respectively. , the third station 4 is the rotary table 1
As shown in FIG. 10, on the upper surface of the table support portion 5a of the base platen 5, a hollow shaft 13 for rotating the table formed in the shape of an inverted funnel encloses a tie bar 6. A rotary table, generally designated by reference numeral 14, is rotatably supported by the hollow shaft 13 via upper and lower ball bearings 15, 16. As shown in FIG.
and three sets of mold opening/closing unit holding parts, 18A and 1, respectively arranged at positions corresponding to each side of the triangle.
8B, 18C, and fan-shaped support plates 19A, 19B supported between adjacent mold opening/closing unit holding parts.
The main part is composed of 19C. 20 is the first
As shown in Figure 2, it is a gear that meshes with a pinion 100 that is directly connected to a motor 101 that is fixed to the table support part 5a on the base platen 5 side. By the rotation of 101, the rotary table 1
4 is configured to rotate intermittently by 1/3 rotation at predetermined timing. This stop positioning is performed by a cylinder mechanism 10 provided on the base platen 5 with a knock pin 102 having a tapered convex portion.
3, and a tapered recess 104 of the same shape provided in the center frame 17 of the rotary table 14.
This is done by matching a to c for each station.

The first station 2 also includes a base platen 5 which is integrally formed with a table support part 5a having a circular shape in plan view and an injection part 5b having an isosceles triangular shape in plan view and is fixed on a foundation on the floor surface. (See Figure 10). At three locations, the center of the table support part 5a and both ends of the isosceles triangle base of the injection part 5b,
Tie bars 6 and 7 are installed vertically.
A tie bar hole of a cylinder platen 8 formed in an isosceles triangular shape is fitted into the upper end of the tie bar 7, and the tie bars 6 and 7 are firmly fixed by nuts 9. The frame is formed in this way and the first station 2
is provided with a mold clamping device 10, an injection device 11, and an automatic hot water supply device 12.

The second station 3 includes an extruded frame 21 fixed to the cylinder platen 8 and installed horizontally and having an isosceles triangular shape in plan view. A tie bar 23 is installed between the extrusion frame 21 and the
(See FIG. 10). The second station 3 having a framework formed in this way has a mold setup device 25 and a product take-out device 26 as shown in FIGS. 9 and 10.
, a protrusion cylinder 27 and an extrusion cylinder 28. The mold setup device 25 is used as a whole with reference numeral 29 at the start of casting work, mold replacement, maintenance, etc.
The mold opening/closing unit shown in
4 mold opening/closing unit holding parts 18A, 18B, 18
A frame 30 extends from below the mold opening/closing unit holder 18A (18B, 18C) to the center line _L2 direction and is fixed to the floor surface. On this frame 30, a large number of rollers 32 are arranged in parallel on both sides, which are driven by a motor 31 via a belt and a chain to rotate selectively in forward and reverse directions.

The mold opening/closing unit 29 holds the fixed mold 33 and the movable mold 34 and performs operations such as clamping and opening the molds.

Furthermore, the third station 4 is not equipped with a frame like the other stations 2 and 3, and the mold opening/closing unit 29 newly supplied to the rotary table 14 at the second station 3 and the mold opening/closing unit 29 from which the product has been removed are not provided. A spray device 35 is provided for cleaning the opened molds 33 and 34 of the unit 29 and spraying a mold release agent thereon. This spray device 35 is supported by a frame 36 and is connected to the hydraulic cylinder 3.
It is equipped with an arm 38 that moves forward and backward at 7, and arm 3
A spray head 39 is attached to the tip of the spray head 8 . Then, a spray head 39 is moved between the two molds 33 and 34 using a hydraulic cylinder 37, cleaning is performed by blowing out air, and a mold release agent is applied by blowing out air and mold release agent. Reference numeral 40 denotes a conventionally known insert insertion device for inserting inserts into the molds 33 and 34 as necessary. After the work at the third station 4, the mold opening/closing unit 29, which has temporarily clamped the molds 33 and 34, is moved to the first station 2 by the rotation of the rotary table 14.
The mold rotates around and stops, and mold clamping and injection are performed.

Mold clamping device 10 in the first station 2
is equipped with a cylinder 41 integrally formed with the cylinder frame 8, and a main ram 43 that is fitted into the cylinder 41 and can be raised and lowered by pressure oil introduced from a port 42. A moving platen 44 is fixed. Further, a pair of pullback cylinders 45 are fixed to the upper surface of the cylinder platen 8, and are located on both sides of the cylinder 41, and their piston rods 46
passes through the cylinder platen 8 and its working end is fixed to the moving platen 44. With this configuration, when pressure oil is introduced from the port 42 and the main ram 43 is lowered,
The molds 34, 34, which have been temporarily clamped, are pressurized via the mold opening/closing unit 29 and are clamped. Further, after the pressure oil above the main ram 43 is removed, the oil is sent to the pullback cylinder 43, whereby the moving platen 44 is raised and the molds 33, 34 are released from the pressurized mold clamping.

The injection device 11 includes an injection cylinder 48 that is supported by a tie bar and a frame 47 that hang down from the base platen 5, and a plunger 50 is connected to a piston rod 49 that is raised and lowered by hydraulic pressure through a coupling 51. This plunger 50 is fitted into an injection sleeve 54 supported by a block 53 which is moved up and down by a ram 52.
The injection sleeve 54, which is raised together with the block 53 by the ram 52, is fitted into the fixed sleeve on the fixed mold 33 side, and as the plunger 50 is raised by the injection cylinder 48, the molten metal in the injection sleeve 54 is clamped. The liquid is injected into the cavities of molds 33 and 34.

Further, the automatic hot water supply device 12 includes a frame 55 erected on the base platen 5, and a device main body 57 supported by the frame via a four-bar link 56. A melting furnace 59 filled with is placed on the floor. When the injection cylinder 48 is tilted by a tilting device (not shown) to the position shown by the chain line _L1 in the figure, the ladle 60 at the tip of the device main body 57 is driven into the molten metal of the melting furnace 59 by the drive of the servo motor 58 or the like. It is configured to draw up the molten metal and move it to a position concentric with the chain line L ₄ via the four-node ring 56 to supply the molten metal into the injection sleeve 54 . After pouring, when the molten metal solidifies and begins cooling, pressure oil is removed from the port 42 and at the same time, pressure oil is introduced into the pullback cylinder 45.
The moving platen 41 is raised to release the pressure. Mold 3 after pressure clamping, injection, and pressure release
The mold opening/closing unit 29, which holds the molds 3 and 34 in a temporarily clamped state, rotates to the second station 3 and stops due to the rotation of the rotary table 14, and the mold is opened and the product is taken out.

That is, the protruding cylinder 27 is equipped with a piston rod that is protruded by hydraulic pressure into the cavities of the molds 33 and 34 where mold opening is started, and thereby the product is held on the side of the movable mold 34. It is configured so that the mold can be opened. Further, the extrusion cylinder 28 is equipped with an extrusion pin at the tip of the piston rod that is lowered by hydraulic pressure and protrudes into the cavity of the movable mold 34 via the mold opening/closing unit 29, and extrudes the product out of the cavity. It is structured like this.

The product take-out device 26 receives the product extruded from the movable mold 34, cools it with water, and then discharges it to the floor, etc. The product take-out device 26 is driven by a hydraulic cylinder 61 to move the product to the illustrated position and the center of the molds 33, 34. It is equipped with a horseshoe-shaped tray 62 that moves forward and backward to and from the position, and a puller 64 that moves forward and backward in a direction perpendicular to the tray 62 using a hydraulic cylinder 63. When the puller 64 is moved back to the illustrated position, the puller 64, which has been waiting at the forward end beyond the tray 62, moves back and pulls out the product onto the basket 65. A link mechanism (not shown) is attached to the basket 65, and when the link mechanism is moved by a driving device, the basket 65 reciprocates between the illustrated position and the cold water tank while holding the product, thereby cooling the product. The cooled product is configured to slide on the chute and be discharged onto the floor or the like. After taking out the product, the mold opening/closing unit 29 remains in the third position with the mold open.
Move to station 4.

The casting operation has been explained in the order of steps for one set of mold opening/closing units 29, but the rotary table 1
Each time the other mold opening/closing unit holders 18B, 18C of 4 stop at the second station 3, the mold opening/closing unit 29 is supplied thereto and the mold opening/closing unit 29 is moved to each station 2,
By performing the same operations as above in steps 3 and 4, a normal casting cycle begins.

A driving method for intermittently rotating and stopping this rotary table is constructed as follows.

As shown in FIG. 11, the rotary table 14 rotating in the direction of the arrow has support plates 19A, 19B, 19C.
First, the first limit switch 105 is operated by a dog 108c provided on the outer periphery of the switch. The first limit switch 105 is for a deceleration command, whereby the motor 101 decelerates according to a predetermined deceleration, and then stops when the second limit switch 106 is activated, and the aforementioned knock pin 102 is subsequently activated. Perform positioning. This is the same for the other two stations, and the limit switch pedestals 107 corresponding to the dogs 108b and 108a are fixed at appropriate locations (for example, the base platen 5, etc.) that remain stationary relative to the movement of the rotary table.

A hydraulic motor is used as the motor 101 because of its relatively low rotational speed and large torque, and FIG. 13 shows a hydraulic circuit for driving the hydraulic motor.

In this hydraulic circuit, the direction and flow rate of the liquid supplied by the hydraulic pressure supply source 109 are controlled by the proportional electromagnetic valve 110, and the rotational direction and rotation speed are controlled by sending the liquid to the hydraulic motor 101. For example, when the neutral position 101b is switched to the 101a side, it is configured to rotate counterclockwise, and the controlled flow rate is determined by the switching amount, that is, the amount of movement of the spool of the proportional solenoid valve 110. 112 is a pilot pressure reducing valve for driving the spool of the proportional solenoid valve. 1
Reference numeral 11 denotes a controller that controls the operating direction and amount of movement of the spool of the valve 110. Upon receiving the signal from the first limit switch 105 mentioned above, the controller first controls the valve opening (i.e., rotational speed) as shown in FIG. _14. to v ₂ at a deceleration of θ ₁ , and then the second limit switch 106
In response to the signal, control is performed to decelerate and stop from v ₂ to zero at a deceleration of θ ₂ . Note that θ ₀ is the acceleration required for the rotary table to rotate from the stop position to the next 1/3 rotation position, and is accelerated to the steady speed v ₁ . In addition, a hydraulic circuit 114 built into the circuit in parallel with the hydraulic motor 101 is operated when the proportional solenoid valve 110 is returned from the state 110a or 110c to the state 110b in an emergency (for example, during an emergency stop). The motor is reversely rotated from the outside by the inertia of the drive unit (rotary table 14 in this embodiment), and is used to release the boosted pressure. Usually, a check valve 115 and a relief valve 116 are used as shown in the figure. Consists of.

[Problems to be Solved by the Invention] As is clear from the above-mentioned overview of the overall operation of the rotary die-casting machine, the time it takes to rotate from one station to the next is unrelated to the work of each station. Since this is extra time, reducing this time as much as possible is the key to increasing productivity. Therefore, it is desired to minimize the range of low speed _v2 (see FIGS. 14 and 15) in which the vehicle is decelerated based on the signal from the first limit switch 105.

However, the deceleration θ ₁ from v ₁ to v ₂ performed by the first limit switch 105 is caused by the proportional solenoid valve 110
is controlled by a function of time, so the trajectory shown in Figure 15
As shown in ab, it tends to become unstable, and if the range of low speed v ₂ is shortened, the time of low speed v ₂ becomes longer if the speed is quickly decelerated as shown in a of Fig. 15.
Even if the rotation time is only extended, if the situation requires time to decelerate as shown in b, the limit switch 1
When a stop command is issued at 06, the flow rate of the rotary table is large because the table movement speed when issuing the rotary table stop command is faster than the predetermined low speed _v2 , and the rotary table stops at a predetermined position. For example, there were cases where the dowel pin 102 could not be inserted.

Further, generally, the driving and positioning of a spool, which is a proportional solenoid valve, which controls the circuit flow rate is performed by pilot pressure control, and its characteristics are not linear as shown in FIG. 16a.

Then, as shown in FIG. 13, the proportional solenoid valve 1
10 is assumed to be controlled using the pressure reducing valve 112, but if the pressure of the pressure supply source 109 changes due to load reduction around the set pressure, the pilot pressure will also change.
The characteristic of the control flow rate with respect to the set value of the valve opening is the 16th
It is easy to change as shown by b and c in the figure.

Therefore, the high speed v ₁ shown in FIGS. 14 and 15
When controlling from y to low speed v ₂ , the valve opening setting value is changed from y ₁ to
Even if it is changed to _y2 , the controlled flow rate will have an error of _Δv2 with respect to the target value of low speed _v2 , as shown in FIG. At high speed v _1, even if there is some variation △v ₁ , the set value itself is large and may be tolerated, but at low speed v ₂ , this variation value △v ₂ may not match the original target value v ₂ . Since the speed becomes relatively large, the controllability and repeatability in this low speed range will be extremely degraded. Therefore, it is necessary to keep the table movement speed constant when issuing the stop command for the rotary table as described above. This made it difficult to control the stop position of the rotary table, making control of the stop position of the rotary table even more unstable.

[Means for solving the problem] A plurality of mold opening/closing units each holding a pair of molds are disposed at appropriate positions in the circumferential direction on the outer periphery of a rotary table, and the rotation of the rotary table is intermittently stopped. In a method for controlling the drive of a rotary table in a rotary die casting machine configured so that work in different processes can be performed simultaneously at each work station provided at the stop position of each mold opening/closing unit, a plurality of rotary tables are arranged in the circumferential direction of the rotary table. It has uneven parts,
Further, a position detection means is provided with a cam having a first concave portion open at the front end of the cam, and is composed of a proximity switch that detects the convex portion of the cam and generates a pulse signal, and a proximity switch that detects the cam itself. established,
The position of the rotary table is reset by a signal from a proximity switch that detects the cam itself in the position detection means, and the position of the rotary table is detected by a position pulse signal emitted by a proximity switch that detects a protrusion, thereby detecting the rotation. A drive control method for a rotary table is characterized in that the rotary table is stopped at a predetermined position by decelerating the rotation speed of the table.

[Function] The present invention provides a position detecting means using a cam having a plurality of uneven portions in the circumferential direction of the rotary table and a proximity switch, and generates a pulse from the position detecting means based on the movement of the uneven portion of the cam to rotate the table. Since the position of the table is accurately detected and the deceleration and stop of the rotary table is controlled based on the pulse signal, prompt deceleration and accurate stop position control are possible.

Furthermore, the position detection means is composed of a proximity switch that detects the cam itself and a proximity switch that detects the convex part of the uneven part formed on the cam, and after detecting and resetting the cam itself, detecting the convex part and moving the rotary table. Since the position is detected, malfunctions due to counting errors can be prevented and accurate control can be performed at all times.

[Embodiment] In an embodiment of the present invention, as shown in FIGS. 1 and 2, a cam 120 is integrally attached to a gear 20 that drives a rotary table 14. The number of cams 120 is the same as the number of work stations, that is, the number of stopping positions of the table. In the illustrated example, there are three stopping positions, so three cams 120, 120a to 120c, are provided at equal intervals on the circumference. ing. A plurality of recesses 132 are formed in the front surface 131 of the cam 120 as shown in FIG. , and another recess 1
It should be wider than 32.

The proximity switch for detecting the cam 120 is arranged vertically on a proximity switch base 124.
The proximity switch bases 124 are fixed to a member that remains stationary with respect to rotation of the rotary table, such as the base platen 5, by means of a bracket 121 (see FIG. 3). Of the two proximity switches, the first proximity switch 1 provided above is
22 is at a height that can detect the front face 131 of the cam 120 attached to the gear 20 with bolts 125, and the lower second proximity switch 123 detects the plurality of recesses 132 provided in the cam 120. The base 124 is fixed at the desired height. still,
The front part 131 of the cam 120 is connected to the rotary table 14
It is formed as a curved flat surface with the center of rotation as the center of curvature.

Therefore, the cam 120 is connected to the rotary table 14,
That is, as the gear 20 rotates, the first proximity switch 122 and the second proximity switch 123, which are fixedly installed, rotate, and as the rotation direction advances toward the right side of the drawing as shown by → in FIG.
The first proximity switch 122 detects the edge 133 of the front side 131 of the front side 131 of the front side 131 of the front side 131 of the front side 131 of the first proximity switch 122 . At this time, the second proximity switch 123 is located in the recess 132 of the cam 120, so it has not yet detected the cam 120. If the rotation continues as it is, the proximity switch 122 will continue to detect the front part 131 of the cam 120 as it continues. On the other hand, the second proximity switch 123
When the cam 120 approaches the first edge 141 of the surface portion 131, the cam 120 is detected, and then the cam 120 is not detected as it approaches the recess 132 again, and when the second edge 142 comes, the cam 120 is detected again... repeat. That is, the first proximity switch 122
0 (120d to 120c) and outputs the signal _S1 , and the second proximity switch 123
outputs a pulse-like signal _S2 corresponding to the recesses provided at equally spaced pitches P on each cam. Therefore, the second proximity switch 123 causes the cam 120 to
A pulse signal can be generated every time the concave portion 132 provided in Based on the signal, the rotary table 14 can be stopped at a predetermined stop position with a required deceleration.

That is, in this embodiment, as described above, the rotary table 14 includes a cam 120 having a flat surface and an uneven portion, a first proximity switch 122 for detecting a flat surface, and a second proximity switch 123 for detecting a convex portion.
2 position detection means are provided, and the multiple recesses 132 formed in the cam 120 are sequentially detected by the two proximity switches 12.
Assume that a signal _S2 having a large number of pulses corresponding to the convex portion is obtained as detected in step 3, and as shown in FIG.
This pulse signal _S2 is counted by the counter 135, and based on this count value, the controller 136
controls the flow rate control valve 140, thereby increasing the rotational speed of the rotary table 14 as shown in FIG.
The deceleration is made sequentially at a constant deceleration rate for each pulse of the pulse signal _S2 from _V1 . In this way, by decelerating the rotational speed of the rotary table 14 for each pulse using the position pulse signal S ₂ generated by the position detecting means, a predetermined number of pulses, that is, the recess 1 provided in the cam 120 is detected.
32, when a predetermined number of recesses 132 are located at the second proximity switch 123, the rotary table 14
will be stopped.

Therefore, in each stop operation, the cam 120
The rotary table 14 can be accurately stopped at a predetermined stop position based on the numerous recesses 132 provided in the rotary table 14 .

Incidentally, FIG. 5 shows the output signal S ₁ of the first proximity switch 122 when the cam 120 is rotated at a constant rotational speed.
and the output signal S ₂ of the second proximity switch 123. The detection range of the first proximity switch 122 is such that the length L 1 of the first recess 132 with respect to the second proximity switch 123 is the length L ₁ of the rotary table 14. It operates earlier by the moving time t ₁ , and also the last recess 132
The operation is cut off after the time t ₂ for the rotary table 14 to move the length L ₂ of the cam after .

Therefore, with the first proximity switch 122, the counter 135 that counts the pulse signal of the second proximity switch 123 can be easily reset at the rising edge of the detection signal of the first proximity switch 122. , the first proximity switch 122
If the position detector is configured so that the second proximity switch 123 counts the recesses only while the cam 120 is being detected, then This makes it possible to always reset the counter at any time, and even if the counter 135 malfunctions due to noise or the like in a rotating part where the cams 120d to 120c are not present,
It is possible to prevent an adverse effect from occurring when actually counting the concave portions, and the position control of the deceleration and stop of the rotary table 14 can be made more reliable.

Further, the hydraulic circuit used in this embodiment is divided into a directional control valve 139 and a flow rate control valve 140, as shown in FIG.
This flow control valve 140 uses the one invented by the present applicants in No. 6863, and as shown in FIG.
As a result, the nut shaft 143 moves back and forth, and the valve spool 1
44, and can control the discharge flow rate of the hydraulic motor 101. This flow control valve 140 is connected to the second proximity switch 123
The pulse-like output signal detected by the counter 1
35, and according to this count value, the opening degree and opening/closing speed of the valve spool 144 of the flow rate control valve 140, which are programmed in advance by the controller 136, can be directly controlled.
The valve opening degree of the flow rate control valve 140 is sequentially decreased in accordance with the detection of the recess 132 provided in the cam 120 fixed at 4. Therefore, in the conventional proportional solenoid valve 110, its pilot pressure changes due to fluid pressure fluctuations in the pressure supply source 109, making it difficult to accurately control the flow rate.In contrast, in this embodiment, the position detection means The valve opening degree is controlled based on the generated pulse signal, and the speed of the rotary table is sequentially reduced to a predetermined deceleration rate by sequentially controlling the amount of liquid flowing out without requiring pilot pressure. Therefore, the rotary table 14 can be accurately decelerated and stopped.

In the embodiment of the present invention, a mold opening/closing unit 29 of 30T or more per set is mounted on a rotary table 14 with a diameter of 6m.
With three sets of molds 33 and 34 installed, it takes only 6 units to rotate, decelerate, stop, and position 120°.
I was able to make it so that it only took a little less than a second.

In the above embodiment, one set of proximity switches is fixedly installed, and the cams are provided at the number of stop positions on the rotary table. Similar results can be obtained by placing the

[Effects of the Invention] As described above, the present invention includes a position detecting means using a cam provided on a rotary table and a proximity switch provided on a fixed part, and decelerates and stops based on a pulse signal output from the proximity switch. The instability of deceleration is eliminated, and the rotary table is decelerated at a stable deceleration at each stop after the start of rotation, and the rotary table can be reliably stopped at a predetermined stop position. The rotary table 14 can be easily and reliably inserted into the rotary table 14 and stopped and fixed.

In addition, it is possible to improve the stopping accuracy of the rotary table and improve the repeatability, and as a result, there is no need to worry even if the rotation speed is increased, so wasted time can be reduced.

[Brief explanation of the drawing]

Fig. 1 is a side view of a rotary table of a rotary die-casting machine, Fig. 2 is a bottom view of the rotary table,
Fig. 3 is a side view of the position detecting means, Fig. 4 is a developed view of the cam of the position detecting means, Fig. 5 is a diagram showing the position pulse signal emitted by the position detecting means, and Fig. 6 is a diagram showing the position pulse signal emitted by the position detecting means. 7 is a diagram showing the drive hydraulic circuit according to the present invention, FIG. 8 is a diagram showing the flow control valve used in the present invention, and FIG. 9 is a diagram showing the entire rotary die casting machine. A plan view, FIG. 10 is a vertical sectional view along the center line of the first station of the rotary die casting machine,
11 and 12 are a plan view and a side view of a conventional rotary table, FIG. 13 is a hydraulic circuit diagram for driving a conventional rotary table, FIG. 14 is a diagram showing speed changes of the rotary table, and FIG. 16 and 16 are diagrams showing speed fluctuations. 5...Base platen, 14...Rotary table, 20...Gear, 100...Pinion, 101
... Hydraulic motor, 102 ... Knock pin, 105
...First limit switch, 106...Second limit switch, 109...Hydraulic pressure supply source, 110...
...Proportional solenoid valve, 112...Pilot valve, 120
...Cam, 122...First proximity switch, 123
...Second proximity switch, 132...Recess, 135
... Counter, 136 ... Controller, 139
... Directional switching valve, 140 ... Flow rate control valve.

Claims (1)

[Scope of Claims] 1. A plurality of mold opening/closing units each holding a pair of molds are disposed at appropriate positions in the circumferential direction on the outer periphery of a rotary table, and the rotary table is intermittently stopped from rotating to open and close each mold. In a rotary table drive control method for a rotary die-casting machine configured to simultaneously perform different processes at each work station provided at a position where an opening/closing unit stops, a cam is moved in the circumferential direction of the rotary table whose drive is controlled. established,
The cam has a curved flat surface whose center of curvature is the center of rotation of the rotary table, and a large number of concave and convex portions, and the first concave portion of the concave and convex portions is shaped to open at the front end in the rotational direction of the cam. position detection means, which is composed of a proximity switch that detects the convex part of the uneven part and generates a position pulse signal, and a proximity switch that detects the flat surface of the cam, is arranged on the fixed position side. The position of the rotary table is determined by resetting the position signal count based on the signal from the proximity switch that detects the flat surface inside the position detection means, and counting the position pulse signal emitted by the proximity switch that detects the convex part inside the position detection means. detect,
A rotary table drive control method for a rotary die-casting machine, characterized in that the rotary table is stopped at a predetermined position by controlling the rotational speed of the rotary table to be decelerated. 2. One position detection means consisting of a set of proximity switches that fix the same number of metal cams to the rotary table as the number of stop positions of the rotary table, and detect the cams and a large number of irregularities provided on each cam. 2. A rotary table drive control method for a rotary die-casting machine according to claim 1, wherein the rotary table drive control method is arranged at a fixed position side of a base platen or the like. 3. A single metallic cam having a plurality of concave and convex portions is fixed to a rotary table, and a position detecting means for detecting a large number of concave and convex portions provided on the cam and each cam is connected to the number of stop positions of the rotary table. The rotary table drive control method for a rotary die-casting machine according to claim 1, wherein the same number of rotary tables are arranged on the fixed position side. 4. A hydraulic motor is used as the drive source for the rotary table, and a flow rate control valve is used that directly drives the valve spool with a pulse motor to control the valve opening degree and opening/closing speed at will. According to claim 1, the rotary table is decelerated and stopped by adjusting the amount of liquid flowing into and out of the hydraulic motor and controlling the rotational speed of the rotary table. A rotary table drive control method for a rotary die-casting machine.