JPH07102438B2 - Rotary table driving control method for rotary die casting machine - Google Patents

Description

DETAILED DESCRIPTION OF THE INVENTION [Industrial application] The present invention rotates a plurality of mold opening and closing units holding a mold on a rotary table, and arranges a plurality of mold opening and closing units arranged at equal intervals on the orbit. The present invention relates to a rotary die casting machine that performs casting work in a work station in the order of processes.

[Prior Art] Previously, the present applicant developed a rotary die casting machine for the purpose of significantly improving productivity. This is at the position where the outer circumference of the rotary table is divided into multiple parts in the circumferential direction.
Each mold opening / closing unit for holding a mold is mounted, and each work is performed in the order of steps while rotating the rotary table and stopping at each of the plurality of work stations arranged on the rotation locus.

To explain the outline of the entire rotary die casting machine, rotary die casting machine 1 is code L _1, L ₂ in Figure 4,
The first station 2, the second station 3, and the third station 4 are provided around the rotary table 14 with the angles formed by the center lines indicated by L ₃ being 120 °, respectively. As shown in FIG. On the upper surface of the table support portion 5a, a hollow shaft 13 for rotating the table, which is formed in an inverted funnel shape, is fixed so as to be concentric with the tie bar 6 and to stand upright.
A rotary table, generally designated by the reference numeral 14, is rotatably supported by the hollow shaft 13 via upper and lower ball bearings 15 and 16. As shown in FIG. 6, the rotary table 14 includes a center frame 17 having a box shape of an equilateral triangle in plan view, and three sets of mold opening / closing unit holders 18A respectively arranged at positions corresponding to respective sides of the triangle. , 18B, 18C and fan-shaped support plates 19A, 19B, 19C supported between the adjacent die opening / closing unit holding portions, and the main parts are formed. The gear 20 meshes with the pinion 100 directly connected to the motor 101 fixed to the table support 5a of the five base platens as shown in FIG. The rotation table 14 is configured to intermittently rotate by 1/3 rotation at a predetermined timing by the rotation of the motor 101 according to a command from. The positioning of this stop is performed by the knock pin 102 having a tapered convex portion at the tip,
The rotary table 14 which is operated by the cylinder mechanism 103 provided in the
It is performed by inserting the taper recesses 104a to 104c of the same shape provided in the center frame 17 of the rotary table 14 at each position.

Further, the first station 2 includes a base platen 5 which is integrally formed with a table support portion 5a having a circular shape in a plan view and an ejection portion 5b having an isosceles triangular shape in a plan view and which is fixed on a foundation of a floor surface. (See FIG. 5). Tie bars 6 and 7 are erected upright at three points, that is, the center of the table support 5a and both ends of the bottom of the isosceles triangle of the injection part 5b, and the upper ends of the tie bars 6 and 7 are isosceles triangles. Shaped cylinder platen 8
The tie bar holes are fitted and the tie bars 6 and 7 are firmly fixed by the nut 9. The mold clamping device 10, the injection device 11 and the automatic hot water supply device 12 are provided in the first station 2 having the frame formed in this way.

The second station 3 is provided with an extrusion frame 21 that is fixed to the cylinder platen 8 and is installed horizontally in an isosceles triangular shape in a plan view. Further, the table support portion 5a of the base platen 5 is provided with a bracket 22. The tie bar 23 is fixed between the extrusion frame 21 and the horizontal frame.
It is provided with a protruding cylinder frame 24 connected with each other (see FIG. 5). The second station 3 thus formed with the skeleton has a mold set-up device as shown in FIGS. 4 and 5.
25, a product take-out device 26, a projecting cylinder 27 and an extruding cylinder 28. The mold setup device 25 includes a mold opening / closing unit generally designated by reference numeral 29 at the start of casting work, mold replacement, maintenance, etc., a mold opening / closing unit holding portion 18A of a rotary table 14 described later, 18B, 18C, which is to be supplied to and removed from the 18B, 18C, and which stops at the second station 3, the mold opening / closing unit holding portions 18A, (18B, 18C) are located below the center line L ₂
A frame 30 fixed to the floor and extending in a predetermined direction.On this frame 30, a large number of rollers 32 driven by a motor 31 via a belt and a chain to selectively rotate in forward and reverse directions are provided on both sides. Are installed side by side.

The mold opening / closing unit 29 holds the fixed mold 33 and the movable mold 34, and operates the movable mold 3 such as clamping and opening.

Furthermore, the third station 4 does not have a skeleton like the other stations 2 and 3, and the mold opening / closing knit 29 newly supplied to the rotary table 14 at the second station 3 and
The mold opening / closing unit 29 from which the product is taken out of the mold 33,3
It is equipped with a spray device 35 for cleaning 4 and spraying a release agent on it. The spray device 35 includes an arm 38 supported by a frame 36 and moved forward and backward by a hydraulic cylinder 37. A spray head 39 is provided at the tip of the arm 38.
Is installed. The spray head 39 is inserted between the molds 33 and 34 by the hydraulic cylinder 37, cleaning is performed by blowing air, and the releasing agent is applied by blowing air and the releasing agent. Reference numeral 40 is a conventionally known insert inserting device for inserting an insert into the molds 33, 34 as needed. After the work at the third station 4,
The mold opening / closing unit 29 in which the molds 33 and 34 are temporarily clamped is rotated to the first station 2 by the rotation of the rotary table 14 and stopped, and the mold clamping and injection are performed.

The mold clamping device 10 in the first station 2 has a cylinder 41 integrally formed with the cylinder frame 8 and a vertically movable main ram 43 which is fitted into the cylinder 41 and lowered by pressure oil introduced from a port 42. A moving platen 44 is fixed to the main ram 43. A pair of pullback cylinders 45 are fixed to the upper surface of the cylinder platen 8 on both sides of the cylinder 41, and their piston rods 46 penetrate the cylinder platen 8 and their working ends are fixed to the moving platen 44. ing. Due to this configuration, port 42
When pressure oil is introduced from the main ram 43 to lower the main ram 43, the molds 34, 34 that have been temporarily clamped are pressed through the mold opening / closing unit 29 and clamped. Further, by removing the pressure oil above the main ram 43 and then feeding the oil to the pullback cylinder 43, the moving platen 44 rises and the mold clamping of the molds 33, 34 is released.

The injection device 11 includes a tie bar hanging from the base platen 5 and an injection cylinder 48 supported by a frame 47, and a piston rod 49 that moves up and down by its hydraulic pressure is
A plunger 50 is connected by a coupling 51, and the plunger 50 is fitted to an injection sleeve 54 supported by a block 53 that moves up and down by a ram 52. And Ram 52
The injection sleeve 54 that rises with the block 53 by
The injection cylinder is fitted to the fixed sleeve on the fixed mold 33 side.
When the plunger 50 is raised by 48, the molten metal in the injection sleeve 54 is injected into the cavities of the molds 33, 34 that have been clamped.

Furthermore, the automatic water heater 12 includes a frame 55 standing on the base platen 5 and a device body 57 supported by the frame 55 via a four-node link 56. Below the device body 57,
A melting furnace 59 filled with the molten metal is placed on the floor surface.
Then, when the injection cylinder 48 is tilted by the tilting device (not shown) to the position shown by the chain line L ₄ , the ladle 60 at the tip of the device body 57 is driven into the molten metal of the melting furnace 59 by driving the servomotor 58 or the like. The molten metal is pumped up, and the chain line is passed through the 4-node ring 56.
It is configured to move to a position concentric with L ₄ and supply the molten metal into the injection sleeve 54. After the molten metal is solidified and starts cooling after pouring, the pressurized water is removed from the port 42 and at the same time pressure oil is introduced into the pullback cylinder 45 to raise the moving platen 44 to release the pressure. The mold opening / closing unit 29, which holds the molds 33, 34 that have completed the pressure mold clamping, injection, and pressure release in the temporary mold clamping state, circulates to the second station 3 by the rotation of the rotary table 14 and stops. It is opened and the product is taken out.

That is, the projecting cylinder 27 has the mold 3 whose mold opening is started.
It is provided with a piston rod that projects into the cavities 3 and 34 by hydraulic pressure, so that the product is held on the movable mold 34 side and opened. Further, the extrusion cylinder 28 is equipped with an extrusion pin at the tip of the piston rod that descends by hydraulic pressure and projects into the cavity of the movable mold 34 via the mold opening / closing unit 29, so that the product is extruded to the outside of the cavity. Is configured.

The product take-out device 26 receives the product extruded from the movable mold 34, cools it with water, and then discharges the product to the floor surface or the like.
It is equipped with a horseshoe-shaped saucer 62 that moves back and forth between the center position of 3,34 and a puller 64 that moves forward and backward by a hydraulic cylinder 63 in a direction orthogonal to the saucer 62, and the product extruded from the mold 34 is moved in the forward position. When the received tray 62 retracts to the position shown in the figure, the puller 64, which has been waiting at the forward limit beyond the tray 62, retracts to pull out the product onto the car 65. The car 65 is provided with a link mechanism (not shown), and when the link mechanism moves in a link by the drive device, the product is cooled by reciprocating between the position shown in the drawing and the cold water tank while the car 65 holds the product, The cooled product slides on the chute and is discharged to the floor or the like. After the product is taken out, the mold opening / closing unit 29 moves to the third station 4 with the mold open.

The casting operation has been described for one set of the mold opening / closing unit 29 in the order of steps, but the mold opening / closing unit 29 is opened every time the other mold opening / closing unit holding portions 18B, 18C of the rotary table 14 stop at the second station 3. Stations provided here
By performing the same operation as above at 2, 3 and 4, the normal pouring cycle is started.

The driving method for intermittently rotating and stopping the rotary table is configured as follows.

A rotary table 14 shown in FIG. 6 which rotates in the direction of the arrow.
7, a pinion 100 fixed to the rotary table 14 and meshing with a gear 20 for driving the rotary table 14 and a hydraulic motor 10 for rotating the pinion 100 are provided below the.
1 is attached.

As shown in FIG. 8, the motor shaft of the hydraulic motor 101 is provided with a first transmission gear 151 for position detection together with the pinion 100, and a rotation angle fixed to the body or the like of the hydraulic motor 101. The second transmission gear 152 attached to the detection rotation shaft 153 of the detector 150 meshes with the first transmission gear 151,
The position of the rotary table 14 can be detected by the rotation angle detector 150.

The rotation angle detector 150 increases the signal value so as to linearly and sequentially increase its output voltage according to the rotation angle of the detection rotary shaft 153 as shown in FIG.
This is a detector that repeats returning the output signal value to the original state when 153 makes one rotation (360 °). The gear 20, the pinion 100,
Each gear ratio of the first transmission gear 151 and the second transmission gear 152 is set to a predetermined value so that when the rotary table 14 makes one rotation, the detection rotation shaft 153 of the rotation angle detector 150 makes three rotations. By setting, the mold opening / closing unit can be installed between the three work stations arranged at equal intervals around the rotary table 14.
When the rotary table 14 makes 1/3 rotation so that the 29 moves, the detection rotary shaft 153 makes one rotation.
The position of the rotary table 14 is detected by the output signal value corresponding to the rotation angle of the.

The output signal S of the rotation angle detector 150 is input to the position control device 154 as shown in FIG.
A reference set value S _m (m = 1, 2, ... N), which is a value of a position for performing deceleration control of the rotary table 14 set in advance in multiple stages, and a value of the output signal S from the rotation angle detector 150 are set. In comparison, when the value of the output signal S coincides with the reference set value S _m , the coincidence signal is sent to the controller 136 as a determination signal, and the flow control valve 140 is controlled by a preset program,
As shown in FIG. 2, the rotation speed of the rotary table 14 is sequentially decelerated from the high speed V ₁ with a constant deceleration for each matching signal corresponding to the reference set value S _m , and the rotary table 14 is located at a predetermined stop position. The rotation table 14 is stopped when the stop position reference value S _n is given.

The reference set value S _m to be set in advance, as shown in FIG. 9, the value S ₁ of the first deceleration position smaller than the value Sn of the last deceleration position, and the value of Sn from the value of S ₁ The value of Sn is sequentially set to be large, and the value of Sn is set in the latter half of the range in which the output signal S continuously increases, and becomes a discontinuous point of the output signal θ.
The control program is simplified by setting the position of = 2nπ not to be the stop position.

Further, the hydraulic circuit is divided into a directional switching valve 139 and a flow control valve 140, and the flow control valve 140 used is the one invented by the applicants in Japanese Patent Publication No. 57-6.863.
140 is a valve of a type that directly drives a ball screw 142 rotated by a pulse motor 141 as shown in FIG.
It controls the discharge flow rate of the hydraulic motor 101, and is programmed in advance by the controller 136 by a coincidence signal corresponding to the reference set value S _m (m = 1, 2, ..., N) of the rotary table 14 described above. Flow control valve 140 valve spool 1
The opening degree and opening / closing speed of 44 are directly controlled, and the valve opening degree is made variable according to the detection value of the detection rotary shaft 153 that rotates at a specific rotation ratio in accordance with the rotation of the rotary table 14.

The brake circuit 114, which is composed of the check valve 115 and the relief valve 116, is a general pressure adjusting circuit and prevents abnormal pressure from being generated in the hydraulic circuit.

In this way, the work stations are arranged at equal intervals with respect to the rotary table 14, and while the mold opening / closing unit 29 moves from one work station to the next work station, the rotary shaft for detection is used.
153 is configured to rotate once, and the reference set value for controlling the rotational position of the rotary table 14 between each work station.
By making S _m (m = 1,2, ... n) common, the control program is simplified, and as shown in the flowchart in FIG.
The mold opening / closing unit 29 is moved to the work station position by successively decelerating the rotation by the discrimination signal based on the comparison between the output signal S from the rotation angle detector 150 and the reference set value S _m, and completing the rotation between one work stations. Stop and knock pin
The work in each step is performed by positioning and fixing the rotary table 14 by 102, and after the work is finished, the deceleration control is performed by repeating the above-described operation shown in the flowchart of FIG. It is a thing.

[Problems to be Solved by the Invention] According to the above-described embodiment, the rotary table 14 having an outer diameter of 6 m is provided with a plurality of mold opening / closing units 29 each having a weight of several tens of tons. Although it is possible to detect the position with high accuracy of about 1 mm on the outer circumference and control the deceleration stop of the rotary table 14, the rotary table 14
Is performed by the knock pin 102 and a plurality of tapered recesses 104a to 104c formed on the back surface of the rotary table 14, and in the rotary table 14 having a diameter of several meters, the formation positions of the tapered recesses 104a to 104c are produced. Since there is an error in accuracy,
Rotating table 14 with evenly spaced work stations
Even if the braking stop control is performed, when the knock pin 102 is inserted into the taper recesses 104a to 104c, the displacement of the taper recesses 104a to 104c causes the rotary table 14 to make a fine motion rotation, which causes a problem of generating an impact. It became like.

[Means for Solving the Problem] The present invention is to fix a rotary table when performing work at each work station by stopping the mold opening / closing units attached to the rotary table at equal intervals.
When using a rotary die casting machine that positions the knock pin by inserting it into the tapered recess formed in the rotary table, the rotary table position when the rotary table is fixed with the knock pin is detected by the rotation angle detector, and this detected value is When the rotary table is rotated, the standard position of the rotary table when stopping the specific mold opening / closing unit at the specific work station is used as a reference, and the deceleration position is calculated based on this stop position as the reference set value S _m. The value of the output signal of the rotation angle detector in 1) is compared with the value of the calculated reference set value S _m to perform deceleration control of the rotary table and this is repeated.

[Operation] The method according to the present invention detects the stop position of the rotary table by the knock pin and stores the stop position to determine the stop position when the specific mold opening / closing unit of the rotary table is stopped next time at the specific work station. Therefore, even if a manufacturing error occurs in the formation position of the tapered recess, the stop position when fixing the rotary table by the specific tapered recess rotates by rotating the rotation of the rotary table according to the position of the tapered recess. The table can be braked and stopped.

[Embodiment] As an apparatus according to an embodiment of the present invention, as shown in FIG. 1, a first gear 151 for transmission to a shaft of a hydraulic motor 101 for rotating a gear 20 integrally provided on a rotary table 14 is shown. And a rotation angle detector 150 that detects the rotation angle of the rotation shaft for detection 153 and the second gear for transmission 152 that rotates the rotation shaft for detection 153 by meshing with the first gear for transmission 151. Provided,
Position control device 1 that receives the output signal of this rotation angle detector 150
54 is also provided, and the rotation angle detector 150 increases its output signal value so that the output voltage is sequentially increased while the rotation shaft 153 rotates, and the output voltage is increased when the rotation shaft 153 makes one rotation. The output signal of the rotation angle detector 150 is sent to the position control device 154 by a detector capable of repeating the increase of the output in proportion to the increase of the rotation angle (see FIG. 2). The position control device 154 sends the rotation angle detector 15
The rotation angle of the rotary table 14 is detected based on the magnitude of the output signal of 0, and the determination signal is sent to the controller 136, and based on the determination signal output from the position control device 154, the controller 136 Controls the flow control valve 140,
Thus, the control of the rotation speed and the stop position of the rotary table 14 is the same as in the conventional case.

An upper limit switch of the lower limit switch 155 that detects that the knock pin 102 is located at the lowered position and an upper limit switch 156 that detects that the knock pin 102 is located at the raised position and is inserted into the tapered recesses 104a to 104c. The detection signal of the switch 156 is guided to the position control device 154, and the knock pin 102 is raised to be inserted into the tapered recesses 104a to 104c, and it is detected that the rotary table 14 is reliably positioned and fixed by the wedge effect of the knock pin 102. The position control device 154 stores the output signal S of the rotation angle detector 150 based on the detection signal from the upper limit switch 156 at this time.

In addition, as shown in FIG. 4, this embodiment is the first station.
Since the second station 3, the second station 3, and the third station 4 are arranged at 120 ° intervals, and the mold opening / closing units provided on the rotary table 14 are also arranged at 120 ° intervals, detection is made when the rotary table 14 makes one rotation. So that the rotary shaft 153 for
Gear 20 for driving the rotary table 14, pinion 100,
It is also possible to determine the gear ratio of the attached first transmission gear 151 and the attached second transmission gear 152, and rotate the detection rotation shaft 153 once every time the mold opening / closing unit moves between the work stations. In the same manner as described above, a 12-bit analog-digital conversion circuit is used for the position control device 154, and by dividing the output of the rotation angle detector 150 into 4096, the rotation angle of the rotary table 14 is approximately 0.03. It is possible to detect at an angle of °.

The embodiment of the present invention uses the rotation angle detector 150 capable of detecting the position with high accuracy as described above, and uses the above-mentioned upper limit switch 1
When a detection signal from 56 is input to the position control device 154,
The value of the output signal S from the rotation angle detector 150 is stored in the position control device 154 as the value of the stop position (stop position reference value Sk), and the position at which the rotation speed is decelerated from the high speed V ₁ is stored as the above. The reference set value S _m (m = 1,2, ... n) for deceleration is calculated with the difference distance ΔS _m (m = 1,2, ... n) from the stop position. difference metric [delta] S ₁ and the stop position, the difference between the distance [delta] S ₂ of then performing deceleration position and the stop position, etc., the angle difference distance between the stop position of the table 14 (delta
S ₁ , ΔS ₂ , ΔS _n ) are set in advance. Then, when calculating the reference set value S _m (m = 1, 2, ... N) of the position where deceleration control is performed based on the stop position stored in the position control device 154, the stop position reference value Sk is the rotation angle. The rotation angle detector 150 is adjusted so that the output signal of the detector 150 has a value in the second half of the increase and is larger than ΔS ₁ . Therefore, the calculated reference set values S ₁ , S ₂ , ... S _n and the stop position reference value Sk
The value of is simply a value that sequentially increases as shown in FIG.

And in this embodiment, work stations are provided at three locations,
Since the rotary table 14 is stopped every 1/3 rotation, the number of work stations J is set to 3, and for each 1/3 rotation of the rotary table 14, the rotary shaft 153 for detection of the rotation angle detector 150 is set. Is rotated once, the three stop position reference values Sk (k = 1, 2, ...) As the stop position reference value Sk of the turntable 14.
J) (J = 3) is initialized to a common value S _0, and drive control of the rotary table 14 is started (see FIG. 3).

In this drive control method, the position control device 154 first calls the first stop position reference value Sk (k = 1). This first stop position reference value Sk (k = 1) is referred to as S ₀ which is the value that is initialized as described above, and the value S ₀ from the value S ₀ as this stop position reference value Sk (k = 1) _A reference set value S ₁ for performing deceleration control is calculated by subtracting _m (m = 1), and when the reference set value S ₁ and the value of the output signal S of the rotation angle detector 150 are compared and they match, The coincidence signal is output to the controller 136 as a determination signal, and the stop position reference value Sk (k = 1)
ΔS _m (m = 2) is subtracted from the reference set value S ₂ to compare with the output signal S from the rotation angle detector 150, and the determination signal is sent to the controller 136 repeatedly to repeat the flow control valve 1
40, thereby sequentially performing deceleration control of the rotary table 14, comparing the output signal S with the stop position reference value Sk (k = 1) and stopping the rotary table 14, the knock pin 102 is raised. The rotation angle detector 150 when the rotary table 14 is fixed and the rotary table 14 is fixed by the knock pin 102.
The value of the output signal S from is newly stored as the value of the stop position reference value Sk (k = 1). When the work at each work station is completed, the value k = 2 is called as the stop position reference value Sk. This stop position reference value Sk (k
= 2), the initial first rotation is the value S ₀ initialized as described above, and if the rotary table 14 rotates, the stop position reference value Sk (k = 2), that is, S _The standard set value by the difference distance ΔS _m (m = 1,2, ... n) with the value of ₀ as the reference
S _m (m = 1, 2, ... N) is calculated, deceleration control is performed while comparing the reference set value S _m with the output signal S from the rotation angle detector 150, and the knock pin 102 is used to rotate the rotary table 14. When fixed, the value of the output signal S at this time is stored as a stop position reference value Sk (k = 2), and the next stop position reference value Sk is stored.
Similarly, for (k = 3), the stop position reference value Sk
Each stop position is stored by rewriting S ₀ , which is the value initially set as (k = 1, 2, 3), into the value of the position actually stopped at each work station.

In this embodiment, the number of work stations (J) is 3
Therefore, the control is performed with the third stop position reference value Sk (k = 3) as a reference, and then the value of k of the stop position reference value Sk is calculated by 3 + 1 to determine the value of k as the number of work stations. It becomes larger than 3 which is (J), and the first stop position reference value Sk (k = 1) is called so that 2 of the rotary table 14 can be called.
The rotation operation is performed.

In this second rotation operation, the first stop position reference value Sk (k
= 1) based on the value stored last time as a reference, deceleration control is performed with the final fixed position of the rotary table 14 at which the rotary table 14 was stopped and fixed by the knock pin 102 as the stop target, and based on this stop position reference value Sk. Rotating table 14
Therefore, when the knock pin 102 is raised, the amount of fine adjustment of the position of the rotary table 14 by the inclined portions of the knock pin 102 and the tapered recesses 104a to 104c is extremely small. 1
It is possible to prevent the mold opening / closing unit 29 and the like from being impacted by the rotation of 4 and similarly in the stop position reference value Sk (k = 2) at the next work station, similarly, the previous rotary table 14 is knocked by the knock pin 102. Deceleration control is performed with the final fixed position that was stopped and fixed as the stop target, and similarly with the stop position reference value Sk (k = 3) at the next work station, the deceleration control is similarly performed with the last final fixed position as the stop target. Yes, and each time the rotary table 14 stops at each stop position, the stop position reference value Sk (k = 1, 2, 3) is updated so as to replace the value with a new stop device value. The fine adjustment amount of the stop position of the rotary table 14 which is always performed when the knock pin 102 is raised can be made extremely small.

In this way, if the position control device 154 calculates in advance the value of the voltage corresponding to each deceleration position as the reference set value, as shown in FIG. 3, the position control device 154 detects the rotation angle. The value of the output signal S of the controller 150 is converted into a 12-bit signal and read, and when the minimum reference set value S ₁ and the value of the output signal S of the rotation angle detector 150 match, the controller 136 determines the match signal. , And change the reference set value to S ₂ ,
When the output signal S from the rotation angle detector 150 coincides with the reference set value S ₂ , the coincidence signal is output again, and the reference set value is changed to S ₃ , which is repeated.
If a coincidence signal of the output signal from the rotation angle detector 150 is output, the position control device 154 temporarily stops its operation. During this time, the rotary table 14 rotates 1/3 and the mold opening / closing unit is rotated. Is completed between the work stations, the rotation control of the next rotary table 14 is similarly performed, and the casting work or the like at each work station can be continued.

Then, the stop position reference value Sk is set in the latter half region of the output signal while the output signal S from the rotation angle detector 150 is being increased.
Further, the differential distance ΔS _m (m = 1) so that the reference set values S ₁ , S ₂ , ..., S _n of the deceleration position can be set to values smaller than the stop position reference value Sk and to be sequentially increased. , 2, ... n) is set,
If the drive control of the rotary table 14 is performed while detecting and confirming the position of the rotary table 14 by these reference set values, the rotation angle detector 15 at the time of starting the rotary table 14
Even if the value of the output signal of 0 is the same value as the stop position reference value Sk, the reference setting value of the position control device 154 is set to a small value S ₁ , so that the position control device 154 causes the rotary table 14 to rotate immediately after the start.
It is possible to surely prevent a malfunction that outputs a determination signal for stopping the operation, and the difference distance ΔS _m is common to the rotation control between the work stations, so that the control program can be relatively simply constructed.

Further, conventionally, as described above, in order to prevent a malfunction occurring at the time of starting the rotation of the rotary table 14, after the start of the start, the position detection operation is stopped for a required length of time by a timer, and thus a stop signal is issued immediately after the start. Although it is generally performed to prevent output, a method of preventing malfunction by this timer is to change the rotation speed of the rotary table 14, especially when changing the rotation speed to be high. , In some cases, the rotary table 14 may rotate to a predetermined position where deceleration control or the like should be performed within the time regulated by the timer.In this case, the timer setting time must be changed together, while drawback of complicated change operations there, embodiments of the present invention is therefore to be compared with the value of the output signal S is replaced with the reference set values S ₁ smaller than the stop position reference value Sk, times Changes and modifications, such as speed is easy.

Since the rotation angle detector 150 has an inflection point at which the output signal S is restored at the position where the rotation angle is 2nπ, the rotation angle detector 150 has the minimum reference set value at this inflection point after the rotary table 14 is started. S ₁
Therefore, the change amount of the liquid flow rate control in the flow rate control valve 140 by the discrimination signal from the position control device 154 based on the minimum reference set value S ₁ is set to zero, and the minimum reference setting is set. It is preferable not to use the discrimination signal, which is a coincidence signal with the value S ₁ , for deceleration control.

In addition, the difference distance ΔS _{m is} set so that the reference set values S _{1 to} S _n are evenly spaced.
Not only when (m = 1,2, ... n) is set, the rotation speed of the rotary table 14 is fast when detecting the position near the deceleration start position, and the rotation speed of the rotary table 14 is slow immediately before the stop. Therefore, it is more preferable to set the interval near the deceleration start position wider than the interval near the stop position and control the deceleration stop while finely detecting the position immediately before the stop.

As described above, the embodiment of the present invention is provided with the detection rotary shaft that rotates in conjunction with the rotary table by interposing a gear from the drive shaft of the hydraulic motor that drives the rotary table. Since a rotation angle detector that outputs a continuous output signal that increases the output in proportion to the rotation angle is used, it is possible to detect the position of the rotary table with extremely high accuracy.
The position where the rotary table is stopped by the knock pin is set as the stop position, and the reference set value Sm of the position for decelerating the rotary table is calculated from this stop position, and the position of the rotary table is detected based on the calculated reference set value Sm. Since this is a method of decelerating and stopping, it is possible to bring the control stop position by the method close to the final stop fixed position by the knock pin with high accuracy, and therefore even if there is a manufacturing error in the formation position of the taper recess, each taper recess and the knock pin Since the rotary table can be properly decelerated and stopped at the stop fixed position by
It is possible to prevent the table from rotating slightly when inserting the knock pin to generate an impact, and even if the drive parts such as gears, hydraulic motors and brackets wear for many years and the stop position shifts, Since the deceleration stop is performed while correcting the previous stop fixed position by the knock pin as the next stop position, there is also an advantage that the followability is high.

[Advantages of the Invention] According to the present invention, when the mold opening / closing units attached to the rotary table at equal intervals are stopped at the positions of the respective work stations and the rotary table is fixed at the work stations, the knock pins are fixed to the rotary table. In the drive control method of the rotary table in the rotary die casting machine that inserts and positions in the formed taper recess, the rotary table position when the rotary table is fixed by knock pins is detected by each rotary detector, and this detected value is specified in the next time. As a reference for the stop position of the rotary table when stopping the mold opening and closing unit at the specific work station, the deceleration position when the next specific mold opening and closing unit is stopped at the specific work station is calculated, and when the rotary table rotates. The deceleration position value calculated as the detected value while detecting the rotation angle at When the value of the deceleration position calculated by the above and the detected value of the detected rotation angle of the rotary table match, the rotation speed is decelerated to a predetermined rotation speed and the control of the rotary table is stopped. , Drive the rotary table of the rotary die casting machine to detect the stop position again and repeat the deceleration stop control at each stop position of the rotary table as the stop position reference when stopping the specific mold opening / closing unit at the specific work station next time. Since it is a control method, it is possible to bring the control stop position by the method close to the final stop fixed position by the knock pin with high accuracy. Therefore, even if there is a manufacturing error in the formation position of the taper recess, the control position depends on each taper recess and the knock pin. The rotary table can be properly decelerated and stopped at the locking fixed position, and the rotary table can be inserted when the knock pin is inserted. It can prevent a slight rotation and generate an impact.Furthermore, even if the drive parts such as gears, hydraulic motors and brackets have been worn down for many years and the stop position has shifted, it will be stopped by the previous knock pin. Since the deceleration stop is performed while the fixed position is corrected as the next stop position, there is an advantage that the followability is high.

[Brief description of drawings]

FIG. 1 is a diagram showing a hydraulic circuit of a hydraulic motor and a position detecting mechanism of a rotary table in the present invention, and FIG. 2 is a diagram showing an example of setting an output of a rotation angle detector and a reference set value.
The figure is a flow chart showing the operation of the position control device,
FIG. 4 is a plan view showing the entire rotary die casting machine,
FIG. 5 is a vertical sectional view taken along the center line of the first station of the rotary die casting machine, FIG. 6 is a plan view of the rotary table, FIG. 7 is a side view of the rotary table of the rotary die casting machine, and FIG. 8 is a rotation angle. FIG. 9 is a diagram showing the mounting of the detector, FIG. 9 is a diagram showing an output of the conventional rotation angle detector and an example of setting the reference set value, and FIG. 10 is a position detection mechanism of the hydraulic circuit of the conventional hydraulic motor and the rotary table. FIG. 11 is a flowchart showing the operation of the conventional position control device, FIG.
FIG. 12 is a graph showing a change in valve opening based on a discrimination signal, and FIG. 13 is a view showing flow rate control valves used in the conventional art and the present invention. 5 ... Base platen, 14 ... Rotary table, 20 ... Gear, 100 ... Pinion, 101 ... Hydraulic motor, 102 ... Knock pin, 109 ... Hydraulic pressure supply source, 136 ... Controller,
139 Direction switch valve, 140 Flow control valve, 150 Rotation angle detector, 151 Transmission first gear, 152 Transmission second
Gears, 153 …… Detection rotary shaft, 154 …… Position control device, 15
4 …… Upper limit switch.

Claims (1)

[Claims] 1. A plurality of mold opening / closing units, each of which has a pair of molds and which holds a pair of molds, is provided with work stations arranged at equal intervals on a circular trajectory of a mold opening / closing unit attached to a rotary table. It has a rotary table arranged at appropriate positions in the circumferential direction so that each mold opening / closing unit can be stopped at the position of each work station all at once.
The rotary table is intermittently stopped and the work stations provided at the stop positions of the mold opening / closing units are configured to simultaneously perform the work of different steps on all the mold opening / closing units. In the drive control method of the rotary table in the rotary die casting machine in which the rotation of the rotary table is stopped and fixed by inserting the knock pin into the tapered recess of the rotary table when performing the work, the mold opening / closing units are positioned by the rotary table at the positions of the respective work stations. Detecting each stop position to stop, the deceleration position when the next specific mold opening / closing unit is stopped at a specific work station is calculated based on the detected stop position, and the rotation angle during rotation of the rotary table is calculated. Calculated while comparing the detected value with the calculated deceleration position value while detecting When the detected deceleration position value and the detected rotation angle detected by the rotary table match, the rotary table is decelerated to a predetermined rotational speed to stop the rotary table braking, and the stop position is detected again. A rotary die casting machine rotary table characterized by repeatedly performing deceleration stop control at each stop position of the rotary table by repeatedly using the stop position reference when stopping a specific mold opening / closing unit at a specific work station next time. Drive control method.