JP2881952B2 - Hot water supply control method for die casting machine - Google Patents

Description

Description: TECHNICAL FIELD The present invention relates to a hot water supply amount control method for a die casting machine.

[Prior art] Conventionally, in a die-casting machine, a casting condition of a die-cast product is always kept constant to obtain a stable and high-quality product, and a thickness of a biscuit formed in a casting opening of the product at the time of casting is kept constant. Also, when taking out the product from the mold by grasping the biscuit part, or cutting off the biscuit part from the product after removal, keep the biscuit part gripping position and equipment installation position etc. constant. To keep the thickness of the biscuit constant to make it easier to work, or to reduce the waste of the molten metal as much as possible and supply the minimum necessary amount to the injection sleeve every time Efforts have been made to ensure that the same amount of molten metal is pumped into the injection sleeve and supplied to the injection sleeve each time.

However, in practice, due to the height of the molten metal in the holding furnace, the temperature of the molten metal to be pumped, the operation accuracy of the automatic supply device itself as a ladder transporter, etc., the amount of molten metal supplied to the injection sleeve gradually or Suddenly, it may come. In the early stage of operation, the amount of hot water could not always be easily set to a desired amount.

Conventionally, as an attempt to keep the amount of hot water supplied at each time constant, for example, as disclosed in Japanese Patent Publication No. 59-21261, a method of performing filling based on the result of measuring the weight of In some cases, the forward stroke of the plunger tip is measured, and the calculation is performed based on the result of calculating the thickness of the biscuit portion by calculation.

[Problems to be Solved by the Invention] In the conventional method of controlling the amount of hot water by measuring the weight of the molten metal pumped out with a ladle, it must be performed while the molten metal is pumped out of the furnace and transported to the injection sleeve. However, it was relatively difficult and troublesome to accurately detect the slight difference in weight during the movement.

On the other hand, when the forward stroke of the plunger tip at the time of filling is measured and the thickness of the biscuit portion is calculated by calculation to control the hot water supply amount, it is necessary to perform calculations and the like, which is troublesome. Also, since the calculation is based on the forward stroke of the plunger tip, if the retraction limit of the plunger tip is slightly different for each injection, the thickness of the biscuit cannot be accurately detected every time. It was not always possible to control the exact amount of hot water supply.

[Means and Actions for Solving the Problems] In the present invention, in order to solve these problems,
A magnetic scale device capable of measuring the distance from the gate to the rear with the gate as the starting point 0 is provided, and the biscuit thickness is directly detected on the scale at the limit of the advance of the plunger tip at the time of injection, and the detected value is set to the set value. When the detected value is outside the set value range, the hot water supply amount is automatically corrected so that the thickness of the biscuit at the time of hot water supply thereafter falls within the set value range.

[Example] FIG. 1 is a schematic view of a die casting machine, 1 is a fixed plate,
2 is a movable plate, 3 is a fixed mold, 4 is a movable mold, 5 is a cavity, 6 is an injection sleeve, 7 is a hot water supply port provided in the injection sleeve 6, 8 is a plunger chip, 9 is a plunger, and 10 is a plunger. Coupling, 11 is an injection cylinder, and 12 is a piston rod of the injection cylinder 11. In this apparatus, when the plunger tip 8 is at the retreat limit position as shown by the dotted line, the hot water supply port 7 is moved by the ladle 13 shown in FIG.
Supplies the molten metal into the injection sleeve 6 from the injection cylinder 11.
The plunger tip 8 is advanced by the operation of
The molten metal is injected into the cavity 5 from 14 to obtain a die cast product. A part of the movable mold 4 protrudes from the entrance of the gate 14, and the front end face 15 faces the injection sleeve 6, and faces the front end face 8 a of the plunger tip 8.
Therefore, when the molten metal has been filled into the cavity 5 by injection, the molten metal solidifies between the distal end face 15 which is a part of the movable mold 4 of the gate 14 and the distal end face 8a of the plunger tip 8. You can make biscuits.

A magnetic scale 16 is integrally provided in parallel with the piston rod 12 at a coupling 10 portion which is a connection portion between the plunger 9 and the piston rod 12. Reference numeral 17 denotes a magnetic head for detecting the thickness of the biscuit, and reference numeral 18 denotes a magnetic head for detecting the injection stroke so that the zero point position can be adjusted. One of the magnetic scales 16 is provided with a point 0 _B on the front side and a scale is provided in the front direction so that the biscuit thickness B can be directly detected, and the other one is The point 0 was set to 0 _S, and a scale was provided in the rear direction so that the injection stroke could be directly detected. 0 point 0 _B biscuits thickness B the plunger tip 8 has the position 0 of the forward limit of contact with the distal end surface 15. Therefore, the thickness of the biscuit formed by the injection can be directly measured by the magnetic head 17. 0 point 0 _S of the stroke S is, the plunger tip 8 has a position came to retreat limit position. Reference numeral 19 denotes a biscuit thickness counter connected to the magnetic head 17, and reference numeral 20 denotes a stroke counter connected to the magnetic head 18.

FIG. 2 shows, for example, an automatic hot water supply device 21 known in Japanese Patent Publication No. 59-21262, 21a is a main body, 22 is a first arm that is driven to rotate, 23 is a second arm, and 13 is a second arm. Ladder rotatably provided at the tip of two arms 23, 24 is an arm
A driving source such as a motor for moving the ladle 13 for rotating the ladle 13 between the holding furnace 26 and the injection sleeve 6 by rotating the 22;
Reference numeral 25 denotes a drive source such as a motor for tilting the ladle 13. By the action of the drive source 25 for tilting the ladle, the ladle 13 can be tilted at the hot water supply port 7 of the injection sleeve 6 to supply the molten metal into the injection sleeve 6, and when the molten metal is pumped in the furnace 26. In addition, the amount of hot water can be changed by appropriately adjusting the angle θ of the ladle 13 when the ladle 13 is put into the molten metal 27. When the molten metal 27 is drawn from the furnace 26, the ladle 13 is returned to a horizontal state and transported.

Therefore, a biscuit is formed at the end of injection in which injection molding is performed by the injection device and the cavity 5 is filled with the molten metal, and when the thickness B of the biscuit falls within the set range, the hot water supply at that time is satisfactory. Therefore, the tilt angle θ of the ladle 13 when pumping the molten metal 27 from the furnace 26 is kept as it is. However, when the thickness B of the biscuit is out of the set range, the tilt angle θ of the ladle 13 when pumping the molten metal 27 from the furnace 26 is appropriately changed so that the predetermined hot water supply amount is obtained. Adjust to

When controlling the hot water supply based on the biscuit thickness B,
For example, as shown in FIG. 3, provided for the set value C, vertically provides certain freedom allowable correction range d, and a free correction allowable value upper limit D _U and freely correction tolerance lower limit D _D, this provided vertically large constant alarm tolerance e the set value C than the free allowable correction range d, alarm tolerance limit and alarm tolerance limit E _U
The E _D provided, hot water amount not corrected when the measured value C is in the automatic correction dead zone area F between the automatic correction tolerance limit D _U and automatic correction tolerance lower limit D _D, measured value C is automatically corrected allowable Value upper limit D _U
An alarm tolerance when in the automatic correction execution area G between and during automatic correction tolerance lower limit D _D an alarm tolerance limit E _D max E _U corrects the subsequent hot water supply amount, measured value alarm tolerance upper limit
E _U greater than, or if the alarm tolerance limit E _D smaller than, with issuing an alarm, the automatic hot water supply apparatus 21 to check the bad place to stop, or repaired, largely corrected by the following hot water supply amount Or set value C.

When the measured value is in the automatic correction execution area G, when the die casting machine or the automatic water heater 21 is started to operate,
Since not yet operated stable, in this case, it determines that the area P ₁ convergence previous parameters, corrects relatively quickly.
For example, if the measured value enters the automatic correction execution area G even once, it is corrected immediately next, or if the measured value enters twice consecutively, for example, M ₁ and M ₂ , the average value is set to ▲ ▼ to the wind that is corrected to the next only difference d ₁ of the value C.

Further, if the driver standing some time since the start of operation is relatively stable, in this case, it determines that the area P ₂ convergence after parameters, corrects while watching how the more number of times. For example, a measurement every time it has been stored in a computer, After entering the measured value even once the automatic correction execution area G, several times e.g. five measurements measured values M ₉ scolded of its final is up The average value ▼ of the measured values of the remaining times excluding the maximum value M ₉ and the minimum value M ₅ is obtained, and the average value ▼ is corrected next time by the difference of the set value C.

FIG. 4 shows another embodiment of the present invention similar to FIG. 1. Reference numeral 28 denotes an origin limit switch, 29 denotes a magnetic head. Counter 19 and stroke counter 20
Connected to both.

In the biscuit thickness counter 19, the tip surface 15 of the gate 14
Is counted as 0 and the rear is counted as +, and a value which becomes 0 at the position of the tip end surface 15 as the gate portion at the origin position 28a where the origin limit switch 28 is located is entered. The stroke counter 20 counts the backward limit position as 0 and counts forward as +, and enters a value at which the backward movement becomes 0 at the origin position 28a.
That is, the operator operates the push-button switch to input at the position of the distal end surface 15 and the stroke counter 20 at this time.
Is read, and the difference of the stroke when the origin is cut is input to the biscuit thickness counter 19 at the origin position.

[Effects of the Invention] In the present invention, a magnetic scale device capable of measuring a distance from the gate portion toward the rear with the gate portion as a starting point is provided. Directly detects and compares this detection value with the set value, and when the detected value is out of the set value range, automatically adjusts the hot water supply amount so that the biscuit thickness during subsequent hot water supply falls within the set value range. Since the correction is made, the detection of the biscuit thickness can be performed very easily and quickly. Then, the biscuit thickness for each injection is detected,
Since the subsequent hot water supply is automatically adjusted based on that value, it is possible to always perform die casting under almost the same injection conditions, and to easily obtain good quality die cast products by automatic continuous operation. it can.

[Brief description of the drawings]

BRIEF DESCRIPTION OF THE DRAWINGS The drawings illustrate an apparatus and the like for carrying out the method of the present invention. FIG. 1 is a longitudinal sectional view of an injection device, FIG. 2 is a front view of an automatic water heater, and FIG. FIG. 4 is a diagram showing one example of a control state, and FIG. 4 is a longitudinal sectional view showing another embodiment of the injection device shown in FIG. 1 ... fixed board, 2 ... movable board, 3 ... fixed mold, 4 ... movable mold, 5 ... cavity, 6 ... injection sleeve, 7 ... hot water supply port, 8 ... plunger tip, 11 ... Injection cylinder, 13 ... Ladle, 14 ... Gate, 15 ... Tip (gate), 16 ... Magnetic scale, 17,18,29 ... Magnetic head, 19 ... Biscuit thickness counter, 20 ... ... Stroke counter, 21 ... Automatic water heater, 24,25 ... Drive source, 26 ... Holding furnace, 27 ... Molten metal, 28a ... Home position.

Continuation of the front page (56) References JP-A-61-175304 (JP, A) JP-A-1-218758 (JP, A) JP-A-1-186257 (JP, A) JP-A-1-154858 (JP) , A) JP-A-59-120354 (JP, A) JP-A-62-197260 (JP, A) (58) Fields investigated (Int. Cl. ⁶ , DB name) B22D 17/30, 17/32

Claims (1)

(57) [Claims] 1. A magnetic scale device capable of measuring a distance rearward from a gate part with the gate part as a starting point 0,
The biscuit thickness is directly detected on the scale at the limit of the advance of the plunger tip during injection, and this detected value is compared with the set value.If the detected value is out of the set value, the biscuit thickness during the subsequent hot water supply A hot water supply control method for a die casting machine in which a hot water supply is automatically corrected to fall within a set value range.