JP6783030B2 - Injection molding machine equipped with a power storage device for heating power supply - Google Patents

Description

The present invention relates to an injection molding machine that heats a heating cylinder by supplying electric power supplied from a factory to a heater.

As is well known in the past, an injection molding machine is composed of a mold clamping device that molds a mold, an injection device that melts resin and injects it into a mold, and the like. It is composed of a screw or the like driven in the axial direction and the rotational direction. In the case of an electric injection molding machine in which these devices are driven by an electric motor, a converter and a plurality of servo amplifiers or inverters are provided. The converter converts the three-phase AC power from the factory into a DC voltage, and the inverter generates a three-phase AC voltage of a desired frequency and supplies it to the motor to drive each device. A heater is provided in the heating cylinder, and three-phase AC power from the factory is supplied to the heater to heat the heating cylinder.

Japanese Unexamined Patent Publication No. 2009-241287 Japanese Unexamined Patent Publication No. 61-132319

Patent Document 1 proposes an electric injection molding machine in which the electric power consumed throughout the molding cycle is smoothed. In this electric injection molding machine, a power storage device is provided on a DC voltage line on the output side of the converter. The power storage device obtains power from a DC voltage line and stores it in a process in which power consumption by the inverter is low, for example, in a mold opening / closing process, a plasticization process, or the like. Then, in the process of high power consumption, specifically, in the injection process, the stored electric power is supplied to the DC voltage line as a DC voltage. As described above, since the electric injection molding machine described in Patent Document 1 is provided with a power storage device capable of storing and supplying power to the DC voltage line, the power supplied to the electric injection molding machine is smoothed and the maximum power is obtained. Becomes smaller. In factories where electric injection molding machines are installed, large-capacity power receiving equipment is installed in consideration of the maximum power, but since the maximum power can be reduced, the capacity of the power receiving equipment can be reduced. .. In addition, the contract electricity charge can be reduced to some extent.

Patent Document 2 describes an electric injection molding machine provided with a power storage device. In this electric injection molding machine, the regenerative electric power regenerated from each device via the motor is stored in the power storage device, and the power stored in the power storage device is supplied to the heater of the heating cylinder. There is. That is, since the electric power supplied to the heater is covered by the regenerative electric power recovered from each device, the electric power can be efficiently used as a whole and the operating efficiency can be improved.

Since the electric injection molding machine described in Patent Document 1 is provided with a power storage device, the power consumed is smoothed. Further, the electric injection molding machine described in Patent Document 2 has high power efficiency because the heating cylinder can be heated by using regenerative power. That is, since these electric injection molding machines can smooth or reduce the power consumption during steady operation, the maximum power of the three-phase AC voltage required from the factory can be reduced. Therefore, the burden on the power receiving equipment of the factory is small, and the electricity charge is low, which is excellent. However, even in these electric injection molding machines, there are some problems to be solved. Specifically, there are some issues regarding the reduction of power consumption at startup. When starting a molding cycle in an injection molding machine, it is necessary to heat the heating cylinder to a predetermined temperature prior to the start. When the stop period is long, the temperature of the heating cylinder is low, so that a considerable amount of electric power is required for heating. In general, a factory often has multiple injection molding machines installed, and if multiple injection molding machines are to be started at the same time, a large amount of electric power is required. Then, the capacity of the power receiving equipment is required to some extent. Further, since the contracted electricity charge is determined by the maximum value of the amount of electricity for 30 minutes, that is, the demand electricity, the demand electricity becomes large when the power consumption of the entire factory at the time of start-up is large. In other words, the contracted electricity charge will inevitably increase. Demand power can be suppressed by slowing the heating rate of the heating cylinder and taking a long heating time. By doing so, the capacity of the power receiving equipment in the factory can be reduced, the power consumption at the time of start-up can be suppressed, and the contracted power charge may be reduced. However, it cannot be adopted because the start of the molding cycle is delayed and the production efficiency is reduced as a result.

An object of the present invention is to provide an injection molding machine that solves the above-mentioned problems. Specifically, it is consumed at the time of start-up even though it is not necessary to take a long time for start-up. The purpose of the present invention is to provide an injection molding machine in which the electric power can be sufficiently reduced, thereby reducing the burden on the power receiving equipment of the factory and reducing the electricity charge.

In the present invention, in order to achieve the above object, the injection molding machine is provided with a power storage device for a heater. The heater power storage device is designed to store three-phase AC power from the factory. To the heater of the heating cylinder, the three-phase AC power from the factory and the power from the power storage device for the heater can be selectively supplied via a predetermined changeover switch. Then, before the start of the molding cycle, the heater is configured to supply electric power from the heater power storage device.

That is, the invention according to claim 1 is provided with a power storage device for a heater that supplies electric power only to the heater of the heating cylinder in order to achieve the above object, and the heater is provided with the heater before the start of the molding cycle. power from use power storage device is configured that the injection molding machine, characterized in that after the start of the molding cycle is a three-phase AC power from the plant are supplied respectively.
According to the second aspect of the present invention, in the injection molding machine according to the first aspect, the injection molding machine includes a changeover switch, and the three-phase AC power from the factory and the power from the heater power storage device are switched. It is configured as an injection molding machine characterized in that it is selectively supplied to the heater via a switch.
The invention described in claim 3 is the injection molding machine according to claim 1 or 2, wherein the heater power storage device consists of a storage battery, at the time of power storage adapted to be power storage in a three-phase AC power from the plant It is configured as an injection molding machine characterized by being.
The invention according to claim 4 is the injection molding machine according to claim 1 or 2, wherein the water storage device for a heater is detachable from the injection molding machine. It is composed.

The present invention as described above, a heater for a power storage device for supplying electric power only to the heater of the heating cylinder, to the heater, the power from the start before the electric storage device for the heater of the molding cycle, after the start the molding cycle It is configured to supply three-phase AC power from each factory. Then, when starting up the injection molding machine, it is not necessary to consume the three-phase AC power from the factory. That is, the apparent power consumption can be suppressed. As a result, the demand power can be suppressed and the burden on the power receiving equipment of the factory can be reduced, and the contracted electricity charge can be reduced. When storing electricity in the heater storage device, it is sufficient to use the electric power at night when the injection molding machine is not in operation. Alternatively, electricity may be stored little by little while the molding cycle is continuously carried out. In any case, since the power required for storage is small, it does not push up the demand power. According to another invention, the power storage device for a heater is composed of a storage battery, and is stored by three-phase alternating current power from a factory at the time of storage . In general, a storage battery can store a sufficient amount of electric power, so that it is guaranteed that sufficient electric power can be supplied to heat the heating cylinder to a required temperature. According to still another invention, the power storage device for the heater is removable from the injection molding machine. Then, if the power storage device for the heater that has already stored electricity in another area of the factory or outside the factory is connected to the injection molding machine, the heating cylinder can be heated immediately, and the power storage device for the heater is disconnected during the molding cycle. It is also possible to store electricity in other places.

It is a block diagram which shows the electric power supply system in the injection molding machine which concerns on embodiment of this invention. It is a block diagram which shows the electric power supply system in the injection molding machine which concerns on 2nd Embodiment of this invention. It is a block diagram which shows the electric power supply system in the injection molding machine which concerns on 3rd Embodiment of this invention.

Hereinafter, embodiments of the present invention will be described. The injection molding machine 1 according to the embodiment of the present invention includes an electric injection molding machine. As shown in FIG. 1, the injection molding machine 1 is connected to the three-phase AC power supply 3 of the factory, and the three-phase AC power is supplied. Similar to the conventional electric injection molding machine, the injection molding machine 1 is provided with a converter, that is, an AC / DC conversion device 4, so that three-phase AC power is converted into a DC voltage. The injection molding machine 1 is provided with various motors such as an injection shaft 6a for driving the screw of the injection device, a mold clamping shaft 6b for opening and closing the mold clamping device, and the inverter 5a corresponding to these motors. 5b, ... Are provided. Therefore, three-phase AC power having a required frequency and current is generated and supplied to the motor.

The injection molding machine 1 according to the present embodiment is characterized in a method of supplying electric power to the heaters 8, 8, ... Provided in the heating cylinder as described below, but is the same as the conventional electric injection molding machine. In addition, the power is directly supplied from the three-phase AC power supply 3 of the factory. That is, the injection molding machine 1 is provided with the first heater control device 10. The first heater control device 10 is provided with, for example, a solid state relay, that is, an SSR, and the R, S, and T lines of the three-phase AC voltage line are connected to different heaters 8, 8, ... Via the SSR. Therefore, the current supplied to each heater 8 can be controlled by switching the SSR.

The injection molding machine 1 according to the present embodiment is provided with a heater power supply device 12 that supplies power to the heaters 8, 8, ... Before the start of the molding cycle. In the present embodiment, the heater power supply device 12 receives a power storage device 13 composed of a storage battery, that is, a heater power storage device, a charging circuit 14 that generates a DC voltage to be stored in the power storage device 13, and DC power from the power storage device 13. It includes a second heater control device 15 that supplies the heaters 8, 8, ... The heater power supply device 12 is adapted to directly supply the three-phase AC power from the factory three-phase AC power supply 3, and the charging circuit 14 converts this into a DC voltage. At this time, the voltage is converted to a voltage suitable for the power storage device 13 as needed, and the power is stored in the power storage device 13. The second heater control device 15 can convert the DC voltage discharged from the power storage device 13 into a voltage suitable for the heaters 8, 8, ..., And supply the DC voltage to these. The injection molding machine 1 according to the present embodiment is provided with a changeover switch 17, and power is selectively supplied to the heaters 8, 8, ... From the first heater control device 10 and the second heater control device 15. It can be switched to. That is, the electric power supplied to the heaters 8, 8, ... Can be switched between the three-phase AC electric power of the factory and the electric power from the heater power supply device 12.

The injection molding machine 1 according to the present embodiment preferably stores electricity in the heater power supply device 12 while the molding cycle is stopped, but may store electricity while the molding cycle is continuously operated. In power storage, the time required for power storage is made relatively long so that the consumption of three-phase AC power from the factory is reduced. When a predetermined amount of electric energy is stored, the storage is stopped. The molding cycle is stopped in the injection molding machine 1, and if the stop is extended for a long time, the heating cylinder cools. When the molding cycle is started, the heating cylinder is heated by the electric power from the heater power supply device 12 prior to the start. That is, the changeover switch 17 is switched so that the heater power supply device 12 is connected to the heaters 8, 8, .... The electric power stored in the electric power storage device 13 of the electric power supply device 12 for the heater is driven by the second heater control device 15 to be supplied to the heaters 8, 8, ..., And the heating cylinder is heated. When the heating cylinder reaches a desired temperature, the changeover switch 17 is switched to connect the first heater control device 10 and the heaters 8, 8, .... As a result, the electric power from the three-phase AC power source 3 of the factory is supplied to the heaters 8, 8, .... The molding cycle of the injection molding machine 1 is started. Since the injection molding machine 1 according to the present embodiment operates in this way, it is possible to suppress power consumption at the start of the molding cycle.

The injection molding machine 1 according to the present embodiment can be deformed in various ways. FIG. 2 shows the injection molding machine 1A according to the second embodiment obtained by modifying the injection molding machine 1. In this embodiment, the power storage device 13'is detachable from the injection molding machine 1A. It has become. The power storage device 13'can be separated from the injection molding machine 1A to store power, and can be connected before starting the molding cycle in the injection molding machine 1A to supply electric power to the heater 8. Other modifications are possible, and FIG. 3 shows the injection molding machine 1B according to the third embodiment, which is a modification of the injection molding machine 1. In the injection molding machine 1B according to the third embodiment, power is supplied to the heater 8 only from the heater power supply device 12'. However, the heater power supply device 12'composed of a charging circuit 14, a heater control device 15', and a power storage device 13, and when the switch 19 is OFF, the power stored in the power storage device 13 is supplied to the heater 8 to switch. When 19 is ON, the three-phase AC power from the factory is converted into a DC voltage by the charging circuit 14, and this is supplied to the heater 8 by the heater control device 15'. Therefore, before the start of the molding cycle, the switch 19 is turned off to heat the heating cylinder with the electric power from the power storage device 13, and when the molding cycle is started, the switch 19 is turned on to supply the electric power from the factory to the heater 8. It should be supplied. The switch 19 may be mounted as a physical device, but may also be mounted as software. The injection molding machine 1 according to the present embodiment can be modified in other ways. For example, although the power storage device 13 of the heater power supply device 12 has been described as being composed of a storage battery, it may be composed of a capacitor capable of storing a relatively large amount of power such as an electric double layer capacitor. The changeover switch 17 can also be modified. The changeover switch 17 selectively switches the power supply destination, but the power supplied to the heater 8 without providing the changeover switch 17 is supplied from the first heater control device 10 and the second heater. It can also be used in combination with the control device 15. Even in this case, when power is supplied to the heaters 8, 8, ... At the start of the molding cycle, the three-phase AC power supplied from the factory via the first heater control device 10 is during normal molding cycle operation. It is preferable to carry out so as not to exceed the average power consumption consumed in. Although the injection molding machine 1 has been described as being composed of an electric injection molding machine in the present embodiment, the heater power supply device 12 can be provided even in the injection molding machine driven by hydraulic pressure, and the molding cycle can be started. The power consumption in front can be suppressed.

1 Injection molding machine 3 Three-phase AC power supply 4 AC / DC converter 5 Inverter 8 Heater 12 First heater control device 12 Heat supply device for heater 13 Power storage device 14 Charging circuit 15 Second heater control device 17 Changeover switch 19 Switch

Claims (4)

A heater power storage device for supplying electric power only to the heater of the heating cylinder, relative to the heater, the power prior to the start of the molding cycle from the heater power storage device, after starting the molding cycle three-phase alternating current from the plant An injection molding machine characterized in that electric power is supplied to each of them. In the injection molding machine according to claim 1, the injection molding machine includes a changeover switch, and the three-phase AC power from the factory and the power from the heater storage device selectively receive the heater through the changeover switch. An injection molding machine characterized in that it is supplied to an electric power machine. The injection molding machine according to claim 1 or 2, wherein the heater power storage device is composed of a storage battery, and is stored by three-phase AC electric power from the factory at the time of power storage. .. The injection molding machine according to claim 1 or 2, wherein the heater power storage device is detachable from the injection molding machine.

Images