JP2017104873A - Control device for pressure pin - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide a control device for a pressure pin which can be manufactured at a low cost.SOLUTION: A control part 10 for controlling an advance speed of a rod 2 of a cylinder 1 is provided on a first load flow channel A which supplies a hydraulic oil from a hydraulic power source P to a cap side chamber 4 of the cylinder 1. The control part 10 is configured in such a manner that three flow rate adjusting valves 11A to 11C and three electromagnetic operational on-off valves 12A to 12C are respectively branch-connected in parallel, and respective flow rate adjusting valves 11A to 11C and respective on-off valves 12A to 12C are connected in series. A pressure sensor 13 for detecting a pressure of the hydraulic oil supplied to the cap side chamber 4 is provided between the control part 10 and the cap side chamber 4. Each of on-off valves 12A to 12C of the control part 10 is on-off controlled according to a pressure detected by the pressure sensor 13.SELECTED DRAWING: Figure 1

Description

  The present invention relates to a pressure pin control device that moves a pressure pin that locally pressurizes molten metal filled in a cavity of a die casting apparatus or a mold of an injection molding machine with a cylinder.

  This type of pressurizing pin control device is an operation in which hydraulic oil from a hydraulic pressure source is supplied to the cylinder chamber of the intensifier by adjusting the flow rate with a flow rate adjustment valve, and is discharged from the pressurizing chamber of the intensifier. Oil is supplied to the cap side chamber of the cylinder, and the cylinder advances the rod and locally pressurizes the molten metal filled in the cavity in the mold with a pressure pin.

JP-A-2003-10956

  However, in such a conventional pressure pin control device, the flow rate adjusting valve that adjusts the flow rate of the hydraulic oil is a current control valve that sets the throttle opening according to the current value. Together with the need for the device, it becomes expensive, and the entire device becomes expensive.

  The subject of this invention is providing the control apparatus of the pressurization pin which can be manufactured cheaply.

  In order to achieve this problem, the present invention has taken the following measures. That is, a pressure pin for locally pressurizing the molten metal filled in the cavity in the mold is provided on the rod of the cylinder, and the cylinder advances to the cap side chamber so as to advance in the direction in which the pressure pin protrudes into the cavity in the mold. The flow path for supplying hydraulic oil and supplying hydraulic oil from a hydraulic power source to the cap side chamber of the cylinder is provided with a control unit for controlling the forward speed of the cylinder rod, and the control unit includes a plurality of flow rate adjustment valves and A plurality of electromagnetically operated on-off valves are connected in parallel with each other, and each flow rate adjusting valve and each on-off valve are arranged in series, and a cap is provided between the control unit and the cylinder cap side chamber. There is provided a pressure sensor for detecting the pressure of hydraulic oil supplied to the side chamber, and a plurality of on-off valves of the controller are controlled to open and close according to the pressure detected by the pressure sensor. A.

In this case, the flow control valve and the on-off valve of the control unit may each be two or more and three or less. In addition, a filter for capturing dust mixed in the hydraulic oil may be provided on the upstream side of the control unit in the flow path for supplying the hydraulic oil from the hydraulic power source to the cap side chamber of the cylinder. Good. Further, a second pressure sensor that detects the pressure of the hydraulic oil from the hydraulic source may be provided between the hydraulic source and the control unit.

As described above in detail, in the first aspect of the present invention, the control unit that controls the forward speed of the cylinder rod connects the plurality of flow rate adjusting valves and the plurality of electromagnetically operated on / off valves in parallel. Each flow control valve and each on-off valve are arranged in series, and the flow control valve is not a current control valve as in the prior art. For this reason, the flow rate adjustment valve can be made inexpensive, and the entire apparatus can be manufactured at a low cost, in combination with the fact that accessory devices such as a controller and an amplifier necessary for the current control valve can be eliminated.

In the invention according to claim 2, the number of flow rate adjustment valves and on-off valves of the control unit is three or less. For this reason, an increase in the number of valves can be suppressed, and the entire apparatus can be manufactured at a lower cost.

According to a third aspect of the present invention, in the flow path for supplying hydraulic oil from a hydraulic source to the cap side chamber of the cylinder, a filter for capturing dust mixed in the hydraulic oil is provided upstream of the control unit. It is arranged. For this reason, it is possible to reliably collect dust of the hydraulic oil supplied to the cap side chamber of the cylinder by adjusting the flow rate by the control unit, and it is possible to reliably prevent malfunction of the control unit due to dust.

According to a fourth aspect of the present invention, a second pressure sensor for detecting the pressure of hydraulic oil from the hydraulic power source is provided between the hydraulic power source and the control unit. For this reason, when the pressure of the hydraulic oil from the hydraulic power source decreases due to the use of the hydraulic power source as another device and the use of the other device, this pressure drop can be detected by the second pressure sensor. The pressure drop abnormality can be surely notified.

1 is a hydraulic circuit diagram of a pressure pin control device according to an embodiment of the present invention.

Hereinafter, an embodiment of the present invention will be described with reference to the drawings.
In FIG. 1, reference numeral 1 denotes a cylinder having a pressure pin 3 at the tip of a rod 2, in which a cap side chamber 4 and a head side chamber 5 having a volume smaller than that of the cap side chamber 4 by a volume corresponding to the cross sectional area of the rod 2 are partitioned. Forming. The cylinder 1 advances the pressure pin 3 in a direction to protrude into the cavities 8 in the molds 6 and 7 by supplying hydraulic oil to the cap side chamber 4 to locally pressurize the molten metal filled in the cavities 8 and the head. By supplying hydraulic oil to the side chamber 5, the pressure pin 3 is retracted in the direction of pulling out from the cavity 8 in the molds 6 and 7, and the pressure pin 3 provided on the rod 2 is movably provided. The cylinder 1 is disposed in a high-temperature environment in the vicinity of the molds 6 and 7 in which the cavity 8 is filled with molten metal.

P is a hydraulic pressure source that discharges hydraulic oil, and is connected to the electromagnetic switching valve 9 by a supply flow path P1. Further, the hydraulic pressure source P is connected to another device (not shown) through a second supply flow path P2 that is branched and connected to the supply flow path P1. T is a tank on the low pressure side for storing hydraulic oil, and is connected to the electromagnetic switching valve 9 by a discharge flow path R1. Further, the tank T is connected to another device (not shown) by a second discharge channel R2 branched and connected to the discharge channel R1. A is a first load flow path that connects between the cap side chamber 4 of the cylinder 1 and the electromagnetic switching valve 9. B is a second load flow path that connects between the head side chamber 5 of the cylinder 1 and the electromagnetic switching valve 9. The electromagnetic switching valve 9 has a neutral position X, a first position Y, and a second position Z at the 4-port 3 position for electromagnetic operation. In the neutral position X, the supply flow path P1 is shut off and the first load flow path A And the second load flow path B are switched to the discharge flow path R1, and the first load flow path A is switched to the supply flow path P1 at the first position Y, and the second load flow path B is discharged to the discharge flow path R1. In the second position Z, the first load channel A is switched to the discharge channel R1, and the second load channel B is switched to the supply channel P1.

A control unit 10 controls the forward speed of the rod 2 of the cylinder 1 and is provided in the first load flow path A. The control unit 10 branches and connects the three flow rate adjusting valves 11A, 11B, and 11C and the three electromagnetically operated on / off valves 12A, 12B, and 12C in parallel, and each flow rate adjusting valve 11A, 11B, and 11C and each The on-off valves 12A, 12B, and 12C are arranged in series, and the flow rate adjusting valves 11A to 11C are arranged upstream of the hydraulic pressure source P. The flow rate adjustment valves 11A, 11B, and 11C are set so that the throttle opening can be freely changed by a manual rotation operation by the operator, and the differential pressure before and after the throttle opening is compensated to be substantially constant regardless of load fluctuations. The flow rate is maintained at the set value. The on-off valves 12A, 12B, and 12C are shut-off valves that open by an energization operation and close by a spring force by a non-energization operation.

A pressure sensor 13 detects the pressure of hydraulic oil supplied to the cap side chamber 4 of the cylinder 1 and is provided between the control unit 10 and the cap side chamber 4. The pressure sensor 13 outputs a detection signal with a set value in two stages. The pressure sensor 13 outputs a first detection signal with a first set value and a second detection signal with a second set value that is higher than the first set value. Is output. The controller 10 opens the first shut-off valve 12A and closes the second shut-off valve 12B and the third shut-off valve 12C until the pressure detected by the pressure sensor 13 reaches the first set value. When the first state of operation and the pressure detected by the pressure sensor 13 reach the first set value, in addition to the first shut-off valve 12A, the second shut-off valve 12B is opened and the third shut-off is performed. A second state that maintains the closed state of the off valve 12C, and a first state that opens all the first to third shut-off valves 12A, 12B, and 12C when the pressure detected by the pressure sensor 13 reaches the second set value. It has 3 states.

Reference numeral 14 denotes a second pressure sensor that detects the pressure of hydraulic oil from the hydraulic power source P, and is provided between the control unit 10 and the hydraulic power source P on the control unit 10 side from the electromagnetic switching valve 9. The second pressure sensor 14 outputs a detection signal when the pressure of the hydraulic oil from the hydraulic power source P falls below a set value, and notifies an abnormality that the pressure of the hydraulic power source P is lowered.

A check valve 15 is disposed in the first load flow path A in parallel with the control unit 10 and prevents flow from the hydraulic power source P toward the cap side chamber 4 of the cylinder 1 and allows flow in the reverse direction. Is provided. Reference numeral 16 denotes a filter with a bypass valve that captures dust mixed in the hydraulic oil, and is arranged in the first load flow path A in series with the control unit 10 and in parallel with the check valve 15. .

Next, the operation of this configuration will be described.
In the state of FIG. 1, the electromagnetic switching valve 9 is located at the neutral position X, the first load flow path A and the second load flow path B are switched and communicated with the discharge flow path R1, and the control unit 10 is connected to the shutoff valve 12A. , 12B and 12C are closed, and the cylinder 1 stops the rod 2 at the original position at the left end.

In this state, when the electromagnetic switching valve 9 is energized and switched to the first position Y, the hydraulic oil from the hydraulic source P flows through the first load flow path A from the supply flow path P1, and dust is captured by the filter 16. The control unit 10 is reached. In response to the switching of the electromagnetic switching valve 9 to the first position Y, the control unit 10 enters the first state in which the first shut-off valve 12 is energized and opens, and the flow rate set by the first flow control valve 11A. Adjust the hydraulic oil to. The hydraulic oil adjusted to the flow rate set by the first flow rate adjustment valve 11 </ b> A of the control unit 10 is supplied to the cap side chamber 4 of the cylinder 1, and the cylinder 1 operates based on the pressure of the hydraulic oil supplied to the cap side chamber 4. The rod 2 is advanced by force, and the molten metal filled in the cavities 8 in the dies 6 and 7 is locally pressurized by the pressure pin 3. As the rod 2 advances, the hydraulic fluid in the head side chamber 5 flows from the second load channel B through the discharge channel R1 and is discharged to the tank T.

In a state where the rod 2 is advanced and the molten metal is locally pressurized by the pressure pin 3, when the solidification of the molten metal proceeds, the pressure reaction force increases and the pressure in the cap side chamber 4 increases. When the pressure in the cap side chamber 4 reaches the first set value of the pressure sensor 13, the pressure sensor 13 outputs a first detection signal, and the control unit 10 adds the second shut-off valve 12A to the second shut-off valve. The off valve 12B is energized to a second state in which it opens and the flow rate set by the second flow rate adjustment valve 11B is added to the flow rate set by the first flow rate adjustment valve 11A to adjust the hydraulic oil to the increased flow rate. To do. The increased flow rate of the cylinder 1 is supplied to the cap side chamber 4 to increase the forward speed of the rod 2 and locally pressurize the molten metal with the pressurizing pin 3.

In this state, when the molten metal further solidifies, the reaction force of pressurization by the pressurization pin 3 further increases, and the pressure in the cap side chamber 4 further increases. When the pressure in the cap side chamber 4 reaches the second set value of the pressure sensor 13, the pressure sensor 13 outputs a second detection signal, and the control unit 10 opens all the shutoff valves 12A, 12B, 12C. The third state is reached, and the hydraulic oil is adjusted to the flow rate set by all the flow rate adjustment valves 11A, 11B, and 11C. The cylinder 1 is further supplied with the increased flow rate to the cap side chamber 4 to further increase the forward speed of the rod 2 and locally pressurize the molten metal with the pressurizing pin 3.

When the pressurization by the pressurizing pin 3 is completed, the electromagnetic switching valve 9 is switched to the second position Z, and the control unit 10 performs a closing operation by deenergizing all the shutoff valves 12A, 12B, and 12C. The hydraulic oil from the hydraulic pressure source P flows through the second load channel B and is supplied to the head side chamber 5 of the cylinder 1. The cylinder 1 uses the acting force based on the pressure of the hydraulic oil supplied to the head side chamber 5 to The hydraulic oil in the cap side chamber 4 moves backward from the cavity 8 in the molds 6 and 7, and the hydraulic oil in the cap side chamber 4 flows from the first load flow path A through the check valve 15 to the discharge flow path R 1 to the tank T. Discharged.

When the rod 2 moves backward to the original position shown in FIG. 1, the electromagnetic switching valve 9 is switched to the neutral position X and the rod 2 is stopped.

With this operation, the controller 10 that controls the forward speed of the rod 2 of the cylinder 1 branches and connects the three flow rate adjusting valves 11A to 11C and the three electromagnetically operated on / off valves 12A to 12C in parallel. Each flow regulating valve 11A to 11C and each on-off valve 12A to 12C are arranged in series, and the flow regulating valve is not a current control valve as in the prior art. For this reason, the flow rate adjustment valve can be made inexpensive, and the entire apparatus can be manufactured at a low cost, in combination with the fact that accessory devices such as a controller and an amplifier necessary for the current control valve can be eliminated.

Further, in the first load flow path A that supplies the hydraulic oil from the hydraulic source P to the cap side chamber 4 of the cylinder 1, a filter 16 that captures dust mixed in the hydraulic oil is provided upstream of the control unit 10. It is arranged. For this reason, it is possible to reliably capture the dust of the hydraulic oil supplied to the cap side chamber 4 of the cylinder 1 by adjusting the flow rate by the control unit 10, and to reliably prevent malfunction of the control unit 10 due to dust.

A second pressure sensor 14 that detects the pressure of hydraulic fluid from the hydraulic power source P is provided between the hydraulic power source P and the control unit 10. For this reason, the hydraulic pressure source P is also used as another device, and when the pressure of the hydraulic oil from the hydraulic power source P is reduced due to the use of another device, the second pressure sensor 14 detects this pressure drop. It is possible to reliably notify the abnormal pressure drop.

In the embodiment, the flow rate adjusting valves 11A to 11C and the on-off valves 12A to 12C of the control unit 10 are each provided with three. However, the present invention is not limited to this. Or four or more. Further, the control unit 10 is configured by arranging the flow rate adjusting valves 11A to 11C upstream of the hydraulic power source P side and in series with the on / off valves 12A to 12C, but the on / off valves 12A to 12C are upstream of the hydraulic power source P side. Of course, the flow control valves 11A to 11C may be arranged in series.

1: Cylinder 2: Piston 3: Pressurizing pin 4: Cap side chamber 6, 7: Mold 8: Cavity 10: Control units 11A, 11B, 11C: Flow rate adjusting valves 12A, 12B, 12C: Shut-off valves (open / close valves)
13: Pressure sensor P: Hydraulic source

Claims (4)

The cylinder rod is equipped with a pressure pin that locally pressurizes the molten metal filled in the cavity in the mold, and the cylinder moves hydraulic oil to the cap side chamber so that the pressure pin is advanced in the direction protruding into the cavity in the mold. The flow path for supplying hydraulic oil from the hydraulic source to the cap side chamber of the cylinder is provided with a control unit that controls the forward speed of the cylinder rod, and the control unit includes a plurality of flow rate adjustment valves and a plurality of flow rate adjustment valves. Each electromagnetically operated on-off valve is branched and connected in parallel, and each flow control valve and each on-off valve are arranged in series, and the cap side chamber is connected between the control unit and the cylinder cap side chamber. A pressure pin control device comprising a pressure sensor for detecting the pressure of hydraulic oil to be supplied, wherein the plurality of on-off valves of the control unit are controlled to open and close according to the pressure detected by the pressure sensor. 2. The pressure pin control device according to claim 1, wherein the flow rate adjusting valve and the on-off valve of the control unit are each three or less. The flow path for supplying hydraulic oil from the hydraulic power source to the cap side chamber of the cylinder is provided with a filter for capturing dust mixed in the hydraulic oil upstream of the control unit. The pressure pin control device according to claim 1 or 2. 3. The pressure pin control according to claim 1, wherein a second pressure sensor is provided between the hydraulic power source and the control unit to detect the pressure of hydraulic fluid from the hydraulic power source. apparatus.

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