JPS5855165A - Controller for packing in accumulator - Google Patents

Abstract

PURPOSE:To assure specified gaseous pressure and oil volume from the start of work and to stabilize operation by providing a control valve and a temp. detector in a circuit for supplying working oil of an accumulator, and making the gaseous pressure regulable according to the change in the temp. of the working oil and gas. CONSTITUTION:A titled device consisting of an accumulator combining a piston type accumulator 5 and a gas accumulator 6, a control valve 20 provided with a circuit for supplying working oil to the accumulator 6, and a temp. detector 21 which detects the temp. of the working oil or the temp. of the gas in the accumulator 6. Said control valve 20 controls the supplying and discharging of the working oil to and from the accumulator 6 in accordance with the output signal from the detector 21. The stable operation is carried out from the start of work by the above-mentioned device.

Description

DETAILED DESCRIPTION OF THE INVENTION The present invention relates to a filling control device for seven accumulators, which is used to supply hydraulic oil for each injection cycle to an accumulator provided for high-speed injection in an injection circuit of a die-casting machine or the like. be.

BACKGROUND ART Conventionally, when a piston-type accumulator and a gas accumulator are used in combination as an accumulator provided in an injection circuit of a die-casting machine or an extrusion press, a circuit as shown in FIG. 1, for example, has been known.

In FIG. 1, 1 is a pump, 2 is a motor, 3 is an injection cylinder, 4 is a switching valve for forward and backward movement of the injection cylinder, 5 is a piston-type accumulator with a slidably built-in piston 5a, 6 is a gas accumulator, and 7 is a valve for high-speed injection, 8
1 is a switching valve provided in a circuit that supplies hydraulic oil to the lower part of the gas accumulator 6, 9 is a pressure switch, 10 is a pressure gauge, 1
1 is a relief valve, 12 to 16 are on-off valves, 17 is a check valve, and 18 is a tank.

However, in the conventional device shown in Fig. 1,
When setting the gas pressure when the gas accumulator 6 is initially filled with gas, or when changing the set gas pressure, open the on-off valve 14 and switch the switching valve 8 to supply hydraulic oil into the gas accumulator 6. There were times when we supplied
Normally, the on-off valve 14 is closed and the switching valve 8 also shuts off the hydraulic oil, and when supplying hydraulic oil to the accumulator for each injection cycle, the on-off valve 12 is kept open.
I only went to piston type accumulator 5.

In these conventional devices,
As described in Publication No. 9405 and Japanese Patent Publication No. 54-30373@, it is possible to reduce the size of a piston-type accumulator and shorten the filling time when filling a gas accumulator with nitrogen gas from a commercially available gas bottle. However, no consideration was given to changes in gas concentration.

That is, if the pressure of the gas such as nitrogen gas filled in the gas accumulator 6 is kept constant,
Changes in proportion to temperature changes. That is, when PO is the pressure at absolute temperature TO and Pl is the pressure at absolute temperature T1, 1 Pl-PG □ T.

However, in general, die-casting machines run out of air during the winter.
! The work starts at about 10°C, and the ambient temperature in steady state is about 50°C. Then, the pressure increases in accordance with this temperature change, and the amount of pressure change due to this temperature difference is approximately 1.14 times, and the influence on die casting performance is a value that cannot be ignored. Moreover, this change does not become stable rapidly, and changes over 30 to 60 stitches from the start of work, and in some cases over about half a day.

Therefore, this causes a decrease in product yield.

Of course, in a conventional AM, it is also possible to open and close the on-off valves 14 and 15 each time depending on the temperature rise of the hydraulic oil and gas, and manually adjust the amount of oil in the gas accumulator 6 each time. It is virtually impossible to manually perform the adjustment every cycle, and it cannot be performed accurately.

The present invention eliminates these drawbacks and automatically adjusts the gas pressure, thereby making it possible to perform injection under stable injection conditions from the start of work, thereby improving product quality.

The present invention includes an accumulator that is a combination of a piston type accumulator and a gas accumulator, and can supply hydraulic oil to the gas 7 accumulator and discharge hydraulic oil from the gas accumulator in the hydraulic oil supply circuit to the gas accumulator. A control valve is provided, and a temperature sensor for detecting the concentration of hydraulic oil or the temperature of gas in the gas accumulator is provided, so that the operation of the control valve can be controlled by an output signal from the temperature sensor.

Next, the present invention will be explained in detail with reference to embodiments shown in the drawings. In addition, in FIGS. 2 to 4, the same parts as shown in FIG. 1 are indicated by the same reference numerals as shown in FIG. 1, and the explanation thereof will be omitted.

In one embodiment shown in FIG. 2, the top of the piston type accumulator 5 and the top of the gas accumulator 6 are connected to each other, and at the top or in the middle of the piston type accumulator 5, there is an operation necessary for injection in the piston type accumulator 5. A position detection device 19 such as a magnetic switch is provided to detect when the piston 5a has come to a position where the oil level is secured.

However, it is not necessary to provide this position detection device 19, and the piston 5a may be stopped by hitting the top of the piston type accumulator 5 or by hitting a mechanical stopper.

A check valve 1 is provided on the pump 1 side of the on-off valve 12, which is located on the hydraulic oil supply side of the piston type cylinder 5 and is always open during operation.
A control valve, which is an electromagnetic switching valve 20 having solenoids a and b, is provided in the circuit that supplies hydraulic oil from the pump 1 to the bottom of the gas accumulator 6, and controls the temperature of the hydraulic oil or the gas in the gas accumulator 6. A temperature sensor 21 for detecting the temperature of the gas accumulator 6 and a pressure sensor 26 for detecting the pressure of the gas accumulator 6 were connected to the circuit between the electromagnetic switching valve 20 and the on-off valve 14. However, since the temperature sensor 1121 and the pressure sensor 26 are originally intended to detect the gas temperature and pressure in the gas accumulator 6, they can be installed in the upper part of the gas accumulator 6 or in the upper part where the gas is sealed. Alternatively, it may be attached to the lower part of the gas accumulator 6 or the lower hydraulic oil sealed part. 22 is a control device which receives electrical input according to the temperature detected by the concentration detector 21, and accordingly excites solenoids a and b of the electromagnetic switching valve 2o as appropriate;
Upon receiving electrical input according to the pressure detected by the pressure detector 26, the solenoid a of the electromagnetic switching valve 20 is activated.
, b can be appropriately demagnetized. The electromagnetic switching valve 20 supplies hydraulic oil to the gas accumulator 6 and discharges hydraulic oil from the gas accumulator 6 into the tank 18 .

23 is a switching valve for unloading the pump 1.

Next, the operation of the accumulator filling control device in the apparatus shown in FIG. 2 will be explained.

During the injection operation, the on-off valves 12, 13, and 14 are always open, and the on-off valves 15, 16 are always closed.

When the electromagnetic switching valve 20 is closed as shown in the diagram, the pump 1 is rotated to start work, and the on-off valve 12.14 is opened, the piston 5a in the piston type accumulator 5 is opened.
approaches the upper limit, and the position detection device 119 detects the upper limit. In this case, the upper limit position of the piston 5a means that when hydraulic oil is supplied into the piston type accumulator 5 and the piston 5a rises in each injection cycle, the supplied hydraulic oil is necessary for a predetermined injection. When the amount is secured, the piston 5a detects the position @ position 1.
This is the position at which the piston type accumulator 5 stops due to the operation of the piston type accumulator 5 or other actions.
It can be in the middle or at the top.

When the position detection device 19 of the piston-type accumulator 5 is activated, an electrical signal is immediately sent to the control device 22, the temperature sensor 21 detects the gas accumulator 6m degrees at that time, and the control device 122 makes a judgment about the temperature.

Then, depending on the temperature detected by the temperature detector 21, the electromagnetic switching valve 2o is switched IIJII+. In other words, when the detected temperature is low and the pressure has not reached the specified pressure, the pump 1 is held in the ○/- position and the tI
The IJ control device f22 excites the solenoid b of the electromagnetic switching valve 2o, and supplies hydraulic oil to the bottom of the gas accumulator 6.
The volume of the gas in the gas accumulator 6 is reduced in proportion to the gas temperature, and this state is maintained until the gas pressure reaches a specified pressure.

When the pressure sensor 126 detects the specified pressure, the solenoid b is demagnetized, the switching valve 23 is operated, and the pump 1 is unloaded.

On the other hand, when the 81 degree detector 21 detects a high degree of pressure and the pressure is higher than the specified pressure, the switching valve 23 is activated to immediately unload the pump 1, and the electromagnetic switching valve 2
0 is energized, the hydraulic oil at the bottom of the gas accumulator 6 is discharged to the tank 18 via the electromagnetic switching valve 20, the volume of gas in the gas accumulator 6 is increased in proportion to the gas temperature, and the pressure is detected. When the gas pressure detected by the device 26 reaches the specified pressure, the solenoid a is demagnetized.

Of course, the position detection device 19 operates and detects the temperature sensor 21 and pressure! When the I26 detects the gas concentration or oil temperature and gas pressure, if the temperature or pressure is within the specified 2i degrees or pressure, the conventional and F
Performs fJ-like operation.

In the above example, when the temperature is low and the gas pressure has not reached the specified pressure, when hydraulic oil is supplied into the gas accumulator 6, the hydraulic oil also tries to be supplied to the bottom of the piston type accumulator 5. Since the same pressure is always maintained in both 7-cumulators 5.6, the piston 5a does not go down and hardly moves. Also, when the concentration is high and the gas pressure is higher than the specified pressure, and the hydraulic oil at the bottom of the gas accumulator 6 is discharged into the tank 18 via the electromagnetic switching valve 20, the piston 5a is never goes down. Therefore, even if the amount of hydraulic oil in the gas accumulator 6 is automatically adjusted and the gas pressure is adjusted after the position detection device 19 is activated, the amount of hydraulic oil in the piston type accumulator 5 enters the injection operation. The specified amount will be maintained until

In another embodiment shown in FIG. 3, the check valve 1 in FIG.
A switching valve 24 for #IrR is used in place of #7a, and it is kept open when supplying hydraulic oil to the piston type accumulator 5. When the position of the piston 5a is detected by the position detection device 19, this switching valve 24 is shown at the same time. Switch and shut off the temperature sensor 21 and control device as shown below! 22 and the electromagnetic switching valves 2 and 0, the same control as described above is performed. Note that as the indicator 27 shown in FIG. 3, a flow rate measuring device is used instead of the pressure detector 26 shown in FIG. Then, the timer is automatically activated for a period of time according to the amount,
By measuring the amount of hydraulic oil and automatically operating a timer for a period of time corresponding to the amount, the volume of gas in the gas accumulator can be brought to a desired value.

In addition, in the embodiment shown in FIG. 4, a pump 1a for supplying hydraulic oil to the gas accumulator 6 is provided in addition to the pump 1 for operating the injection cylinder 3 and supplying hydraulic oil to the piston type accumulator 5. Ta.

2a is a motor, and 25 is a switching valve for unloading the pump 1a.

The piston type accumulator 5 may be installed upside down or in any other condition as long as the piston type accumulator 5 is connected to the gas accumulator 6 by hydraulic oil and the gas acting side.

In this way, in the present invention, the configuration as described in the claims is adopted, and the gas pressure of the accumulator is automatically adjusted in response to this m* barbarism without ignoring temperature changes of hydraulic oil and gas. In addition, this adjustment can be made in accordance with the temperature of each injection cycle, so in die casting machines etc.
At the start of work, even when the concentration of hydraulic oil or gas is still relatively low, the predetermined WI in the piston type accumulator
Since not only the quantity but also the predetermined gas pressure can be easily and reliably obtained every time, it is possible to immediately start producing saddle products of good quality. Even when the temperature of the hydraulic oil or the like becomes relatively high, a predetermined gas pressure and oil amount can be automatically and reliably and easily obtained, and high-quality products can always be obtained.

Note that the gas pressure is high when the hydraulic oil has been filled, and low after injection has finished, and changes during one cycle, but when the specified amount of hydraulic oil is supplied to the piston-type accumulator, the gas pressure immediately rises inside the gas accumulator. If you adjust the volume of the gas so that it is stable, you can reliably control the gas pressure and oil amount. Of course, when the gas pressure or the volume of gas in the gas accumulator reaches a specified pressure or amount, the pump can be unloaded to save energy.

[Brief explanation of the drawing]

Figure 1 is a hydraulic circuit diagram showing an example of a conventional device, and Figures 2 to 4
The figures are hydraulic diagrams showing different embodiments of the apparatus for carrying out the method of the invention. 1.1a...Pump, 3...Injection cylinder, 4.8
．． 23-25...Switching valve, butt...Piston type accumulator, 5a...Piston, 6...Gas accumulator, 7...Valve, 12-16...Opening/closing valve, 19...
・Position detection device, 20... Solenoid switching valve, 21... Temperature detector, 22... Control device, 26... Pressure detector, 27... Indicator (flow rate measuring device) 1N1 diagram Figure 2

Claims (1)

[Claims] The accumulator is a combination of a piston type accumulator and a gas accumulator, and a control valve is provided in the hydraulic oil supply circuit to the gas accumulator to supply hydraulic oil to the gas accumulator and to discharge hydraulic oil from the gas accumulator. A wI device on the filling side of an accimulator, which is equipped with an 11 degree detector that detects the temperature of oil and the temperature of gas in a gas accumulator, and is capable of controlling the operation of a control valve based on the output signal from the hot water temperature detector.