CN203161686U - Hydraulic device and industrial machinery - Google Patents

Abstract

Provided are a hydraulic device and industrial machinery. The hydraulic device can use an induction motor to drive a hydraulic pump to control the pressure and flow of working oil, and the price is low. As a solution, the hydraulic device has: a hydraulic pump (5); an induction motor (4), which drives the hydraulic pump (5); an inverter device (3), which outputs a drive signal for rotating the induction motor (4); and a control device (2) which controls the inverter device (3).

Description

Hydraulics and Industrial Machinery

technical field

The utility model relates to a hydraulic device and an industrial machine.

Background technique

Conventionally, as a hydraulic device, there is a device that drives a hydraulic pump that supplies hydraulic oil to a molding machine with a servo motor (for example, refer to JP-A-2011-115967 (Patent Document 1)).

In the hydraulic system described above, the drive control of each actuator of the molding machine is performed by controlling the discharge flow rate and discharge pressure of the hydraulic pump by controlling the rotational speed of the servo motor to be variable.

However, since the servo motor used in the above-mentioned hydraulic device is expensive, cost reduction of the hydraulic device is hindered.

patent documents

Patent Document 1: Japanese Patent Laid-Open No. 2011-115967

Utility model content

Therefore, an object of the present invention is to provide an inexpensive hydraulic device capable of controlling the pressure and flow rate of hydraulic oil by driving a hydraulic pump using an induction motor, and an industrial machine including the hydraulic device.

In order to solve the above-mentioned problems, the hydraulic device of the present invention is characterized in that it has: a hydraulic pump; an induction motor that drives the hydraulic pump; an inverter device that outputs a drive signal that rotates the induction motor; and a control device that It controls the above-mentioned inverter device.

According to the above configuration, the inverter device is controlled by the control device, the induction motor is rotated by the drive signal output from the inverter device, and the hydraulic pump is driven by the induction motor, thereby achieving a low cost compared to an expensive servo motor. An inexpensive hydraulic device that controls the pressure and flow of working oil by driving a hydraulic pump with an inexpensive induction motor.

In addition, a hydraulic system according to one embodiment includes: a pressure sensor that detects the discharge pressure of hydraulic oil of the hydraulic pump; and a rotation speed sensor that detects the rotation speed of the induction motor, and the control device is configured based on the pressure sensor. The detected discharge pressure of the hydraulic oil discharged from the hydraulic pump and the rotational speed of the induction motor detected by the rotational speed sensor control the inverter device, thereby controlling the flow rate of the hydraulic oil discharged from the hydraulic pump. pressure and flow.

According to the above-described embodiment, the inverter device is controlled by the control device based on the discharge pressure of the working oil discharged from the hydraulic pump detected by the pressure sensor and the rotational speed of the induction motor detected by the rotational speed sensor, thereby controlling the slave hydraulic pump. The pressure and flow rate of the hydraulic oil discharged from the hydraulic pump can thus be optimally controlled according to the machine using the hydraulic device.

Moreover, in the hydraulic system of one Embodiment, the said hydraulic pump is a fixed displacement type hydraulic pump.

According to the above-described embodiment, since the rotational speed of the induction motor is controlled without performing capacity control of the hydraulic pump, it is possible to simplify the control process of the pressure and the flow rate of hydraulic oil discharged from the hydraulic pump.

Moreover, in the industrial machine of this invention, it is characterized by having the above-mentioned hydraulic device.

According to the above configuration, by using an inexpensive hydraulic device capable of controlling the pressure and flow rate of hydraulic oil by driving the hydraulic pump with the induction motor, it is possible to reduce the cost of the industrial machine.

The effect of utility model

From the above, according to the present invention, it is possible to realize an inexpensive hydraulic device capable of controlling the pressure and flow rate of working oil by driving a hydraulic pump with an induction motor, and an industrial machine including the hydraulic device.

Description of drawings

FIG. 1 is a configuration diagram of an injection molding machine as an example of an industrial machine using a hydraulic device according to an embodiment of the present invention.

Fig. 2 is a block diagram of main parts of the above injection molding machine.

Label description

1…host controller

2…control device

2a...PQ control department

2b...Speed control unit

3…Inverter device

4…induction motor

5…hydraulic pump

6...Switching valve

7…Fuel tank

10...hydraulic device

11…encoder

12…Pressure sensor

21, 31...Mold

22...movable disc

23... Clamping cylinder

24...Closing device

32…fixed plate

33...Heating cylinder

34…injection cylinder

35…Injection molding device

Detailed ways

Hereinafter, the hydraulic device and industrial machine of the present invention will be described in detail based on the illustrated embodiment.

FIG. 1 shows a block diagram of an injection molding machine as an example of an industrial machine using a hydraulic device according to an embodiment of the present invention.

As shown in FIG. 1 , the injection molding machine of this embodiment has a main body controller 1 , a control device 2 , an inverter device 3 , an induction motor 4 , and a fixed displacement hydraulic pump 5 . The host controller 1 outputs a control signal to the inverter device 3 .

In addition, the above-mentioned injection molding machine has: a pair of molds 21, 31; a movable platen 22 on which one of the molds 21 is mounted; a mold clamping cylinder 23 for moving the movable platen 22 forward and backward; and a mold clamping device equipped with the mold clamping cylinder 23. 24; the fixed plate 32 on which the other mold 31 is installed; the heating cylinder 33 whose front end is inserted into the injection port of the fixed plate 32; the injection cylinder 34 that moves the heating cylinder 33 forward and backward; and the injection molding device on which the injection cylinder 34 is installed 35.

The hydraulic device 10 is composed of the control device 2 , the inverter device 3 , the induction motor 4 , and the hydraulic pump 5 .

The mold clamping cylinder 23 and the injection cylinder 34 described above are driven by hydraulic oil supplied from the hydraulic device 10 via the switching valve 6 .

In addition, a pressure sensor (not shown) is provided in the injection molding machine to detect the discharge pressure of the hydraulic pump 5 , the internal pressure of the clamping cylinder 23 , the internal pressure of the injection cylinder 34 , and the like.

In addition, the hydraulic pump 5 is a hydraulic pump such as a gear pump, a trochoid pump, a vane pump, and a piston pump, and sucks and discharges working oil from the oil tank 7 (shown in FIG. 2 ).

In the above-mentioned injection molding machine, the inverter device 3 controls the induction of the hydraulic device 10 based on the discharge pressure of the hydraulic pump 5 of the hydraulic device 10, the internal pressure of the clamping cylinder 23, the internal pressure of the injection cylinder 34, and the like. The rotational speed of the motor 4. At this time, the inverter device 3 rotates the induction motor 4 at a rotation speed corresponding to each operation of the injection molding machine based on a rotation speed signal indicating the rotation speed of the induction motor 4 from a rotation speed detection encoder (not shown). .

FIG. 2 shows a block diagram of main parts of the above-mentioned injection molding machine.

As shown in FIG. 2 , the control device 2 has a PQ control unit 2 a that receives a pressure command value and a flow rate command value, and a speed control unit 2 b that receives a command signal from the PQ control unit 2 a and outputs a control signal to the inverter device 3 . . The above-mentioned pressure command value and flow command value are output from the host controller 1 (shown in FIG. 1 ).

In addition, the output shaft of the induction motor 4 driven to rotate by the inverter device 3 and the input shaft of the hydraulic pump 5 are connected via a coupling (not shown).

Furthermore, a pressure sensor 12 is provided on the discharge side of the hydraulic pump 5 . In addition, an encoder 11 as an example of a rotation speed sensor for detecting the rotation speed of the induction motor 4 is provided on the coupling connecting the output shaft of the induction motor 4 and the input shaft of the hydraulic pump 5 . The encoder 11 may be, for example, an optical rotary encoder composed of a circular plate having a plurality of slits and an optical sensor for detecting the presence or absence of slits in the rotating circular plate, or may be a magnetic rotary encoder, etc. .

The above-mentioned PQ control unit 2a receives the signal indicating the discharge pressure from the pressure sensor 12 and the rotation speed signal from the encoder 11, and outputs a command signal to the speed control unit 2b so that the discharge flow rate of the hydraulic pump 5 becomes the flow command value and the hydraulic pressure The discharge pressure of the pump 5 becomes the pressure command value. In addition, the PQ control unit 2a receives the signal indicating the discharge pressure from the pressure sensor 12 and the rotation speed signal from the encoder 11, and outputs a command signal to the speed control unit 2b so that the discharge pressure and the discharge flow rate follow the internally set Pressure flow characteristics.

Then, the above-mentioned speed control unit 2b receives the command signal from the PQ control unit 2a and the rotation speed signal from the encoder 11, and outputs a control signal to the inverter device 3 so that the induction motor 4 operates at a speed based on the input from the PQ control unit 2a. Rotate at the target rotation speed of the command signal.

In addition, in the speed control unit 2b, based on the signal indicating the discharge pressure from the pressure sensor 12, feedforward control using the load torque derived by calculation is performed.

According to the hydraulic device 10 of the above-mentioned structure, the inverter device 3 is controlled by the control device 2, the induction motor 4 is rotated by the drive signal output from the inverter device 3, and the fixed displacement hydraulic pump 5 is driven by the induction motor 4, thereby , compared with an expensive servo motor, it is possible to realize an inexpensive hydraulic device that can control the pressure and flow rate of working oil by using an inexpensive induction motor 4 to drive a hydraulic pump 5 .

In addition, the inverter device 3 is controlled by the control device 2 based on the discharge pressure of the working oil discharged from the hydraulic pump 5 detected by the pressure sensor 12 and the rotation speed of the induction motor 4 detected by the encoder 11, and the slave device 3 is controlled. The flow rate of the hydraulic oil discharged from the hydraulic pump 5 can thereby be optimally controlled for the pressure and flow rate of the hydraulic oil discharged from the hydraulic pump 5 according to the injection molding machine using the hydraulic device 10 .

In addition, controllability of the pressure and flow rate of the hydraulic oil discharged from the hydraulic pump 5 can be improved by controlling the rotation speed of the induction motor 4 without performing the capacity control of the hydraulic pump 5 described above.

In addition, according to the above-mentioned injection molding machine as an industrial machine, the cost reduction of the injection molding machine can be achieved by using an inexpensive hydraulic device 10 capable of controlling the pressure and flow rate of hydraulic oil by driving the hydraulic pump 5 using the induction motor 4 .

In the above-mentioned embodiments, an injection molding machine has been described as an industrial machine equipped with a hydraulic device, but the industrial machine is not limited to this, and the present invention can also be applied to a molding machine of another structure, or to industrial machines such as presses and work machines. Utility model hydraulic device.

Although the concrete embodiment of this invention was demonstrated, this invention is not limited to the said embodiment, Various changes can be added and implemented within the range of this invention.

Claims (4)

1. a hydraulic pressure installation (10) is characterized in that, this hydraulic pressure installation (10) has:

Oil hydraulic pump (5);

Induction motor (4), it drives above-mentioned oil hydraulic pump (5);

DC-to-AC converter (3), its output make the driving signal of above-mentioned induction motor (4) rotation; And

Control gear (2), it controls above-mentioned DC-to-AC converter (3).

2. hydraulic pressure installation according to claim 1 (10) is characterized in that,

This hydraulic pressure installation (10) has:

Pressure transducer (12), it detects the head pressure of the work oil of above-mentioned oil hydraulic pump (5); And

Rotation speed sensor (11), it detects the rotational speed of above-mentioned induction motor (4),

Above-mentioned control gear (2) is according to by the head pressure of the detected work oil of discharging from above-mentioned oil hydraulic pump (5) of above-mentioned pressure transducer (12) with by the rotational speed of the detected above-mentioned induction motor of above-mentioned rotation speed sensor (11) (4), control above-mentioned DC-to-AC converter (3), thus, control is from pressure and the flow of the work oil of above-mentioned oil hydraulic pump (5) discharge.

3. hydraulic pressure installation according to claim 1 (10) is characterized in that,

Above-mentioned oil hydraulic pump (5) is fixed capacity type oil hydraulic pump.

4. an industrial machine is characterized in that, this industrial machine has any described hydraulic pressure installation (10) in the claim 1 to 3.

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