阅读说明：本技术 精密闭式油路油电复合注塑机 (Precision closed oil-way oil-electricity composite injection molding machine ) 是由 商铁虎 于 2020-07-30 设计创作，主要内容包括：本发明涉及流体工作系统技术领域,具体为精密闭式油路油电复合注塑机,包括若干组闭式油路驱动系统,闭式油路驱动系统包括：若干组液压执行机构、油泵、电机以及控制系统,每组液压执行机构均包括液压执行部件、换向器件和主传感器；油泵通过进油管路、出油管路与每组液压执行机构均组成闭式液压油路；电机与油泵传动连接,电机用于驱动油泵；控制系统与电机以及主传感器均电连接,控制系统用于根据负载信息生成控制指令对电机进行实时闭环控制。本申请的精密闭式油路油电复合注塑机,更加节能环保,同时能够解决现有技术在控制精度、使用寿命等方面存在的问题,提高控制精度、延长液压元件使用寿命。(The invention relates to the technical field of fluid working systems, in particular to a precise closed oil way oil-electricity compound injection molding machine, which comprises a plurality of groups of closed oil way driving systems, wherein each closed oil way driving system comprises: the hydraulic control system comprises a plurality of groups of hydraulic actuating mechanisms, oil pumps, motors and a control system, wherein each group of hydraulic actuating mechanisms comprises a hydraulic actuating part, a reversing device and a main sensor; the oil pump and each group of hydraulic actuating mechanisms form a closed hydraulic oil way through an oil inlet pipeline and an oil outlet pipeline; the motor is in transmission connection with the oil pump and is used for driving the oil pump; the control system is electrically connected with the motor and the main sensor and is used for generating a control instruction according to the load information to carry out real-time closed-loop control on the motor. The application discloses accurate closed oil circuit oil electricity composite injection molding machine, it is energy-concerving and environment-protective more, can solve the problem that prior art exists in the aspect of control accuracy, life etc. simultaneously, improve control accuracy, extension hydraulic component life.)

1. Accurate closed oil circuit oil electricity compound injection molding machine, its characterized in that: including control system and a plurality of closed oil circuit actuating system of group, closed oil circuit actuating system includes:

each group of hydraulic actuating mechanisms comprises a hydraulic actuating part, a reversing device and a main sensor, wherein the hydraulic actuating part comprises a first oil port and a second oil port, the reversing device is communicated with the first oil port of the corresponding hydraulic actuating part through a first oil path, and the reversing device is communicated with the second oil port of the corresponding hydraulic actuating part through a second oil path; the main sensor is used for acquiring load information capable of reflecting the motion condition of a load driven by the hydraulic execution component;

the oil pump is communicated with each reversing device through an oil return pipeline, an oil outlet of the oil pump is communicated with each reversing device through an oil inlet pipeline, and the oil pump and each group of hydraulic actuating mechanisms form a closed hydraulic oil circuit through the oil inlet pipeline and the oil outlet pipeline;

the motor is in transmission connection with the oil pump and is used for driving the oil pump;

the control system is electrically connected with the motor and the main sensor and is used for generating a control instruction according to the load information to carry out real-time closed-loop control on the motor.

2. The precise closed oil way oil-electric compound injection molding machine according to claim 1, characterized in that: an overflow pipeline is arranged between the oil inlet pipeline and the oil return pipeline, and an overflow valve is arranged on the overflow pipeline.

3. The precise closed oil way oil-electric compound injection molding machine according to claim 1, characterized in that: and a negative pressure compensation pipeline is also arranged between the oil inlet pipeline and the oil return pipeline, and a one-way valve is arranged on the negative pressure compensation pipeline.

4. The precise closed oil way oil-electric compound injection molding machine according to claim 1, characterized in that: the oil return device also comprises a hydraulic energy accumulator and a cooler, wherein the hydraulic energy accumulator and the cooler are both arranged on the oil return pipeline.

5. The precise closed oil way oil-electric compound injection molding machine according to claim 1, characterized in that: the reversing device is a reversing valve which is used for opening, closing and reversing of a closed hydraulic oil path and comprises four ports, wherein two ports are respectively communicated with an oil inlet pipeline and an oil return pipeline, and the other two ports are respectively communicated with a first oil path and a second oil path.

6. The precise closed oil way oil-electric compound injection molding machine according to claim 1, characterized in that: the closed oil way driving systems are two groups and are respectively a first closed oil way driving system and a second closed oil way driving system, the first closed oil way driving system is used for driving the die closing system, and the second closed oil way driving system is used for driving the injection system.

7. The precise closed oil way oil-electric compound injection molding machine according to claim 6, characterized in that: the hydraulic actuating mechanism of the first closed oil way driving system comprises a mold adjusting actuating mechanism, a mold opening and closing actuating mechanism, a thimble action actuating mechanism and an auxiliary core pulling action actuating mechanism, and the mold adjusting actuating mechanism comprises a mold adjusting reversing valve and a mold adjusting hydraulic motor; the die opening and closing actuating mechanism comprises a die opening and closing reversing valve and a die opening and closing hydraulic cylinder; the ejector pin action executing mechanism comprises an ejector pin action reversing valve and an ejector pin hydraulic cylinder, and the auxiliary core pulling action executing mechanism comprises an auxiliary core pulling action reversing valve.

8. The precise closed oil way oil-electric compound injection molding machine according to claim 6, characterized in that: the hydraulic actuating mechanism of the second closed oil path driving system comprises an injection nozzle moving actuating mechanism and an injection actuating mechanism, and the injection nozzle moving actuating mechanism comprises an injection nozzle moving reversing valve and an injection nozzle moving hydraulic cylinder; the injection executing mechanism comprises an injection reversing valve and an injection hydraulic cylinder.

9. The precise closed oil way oil-electric compound injection molding machine according to claim 1, characterized in that: the oil return system is characterized by further comprising a slave sensor, wherein the slave sensor is arranged on the oil inlet pipeline and the oil return pipeline, the slave sensor is used for detecting hydraulic pressure information at the position where the slave sensor is located, and the control system is further used for adjusting a control instruction according to the pressure information.

10. The precise closed oil way oil-electric compound injection molding machine according to claim 1, characterized in that: the control system adopts a full-digital PID motion control algorithm to carry out real-time closed-loop control.

Technical Field

The invention relates to the technical field of fluid working systems, in particular to a precise closed oil way oil-electricity compound injection molding machine.

Background

The injection molding machine is also known as a plastic injection molding machine. It is a main forming equipment for making various shaped plastic products from thermoplastic plastics or thermosetting plastics by using plastic forming mould. An injection molding machine generally comprises an injection system, a mold closing system, a hydraulic system, an electrical control system, a lubricating system, a heating and cooling system, a safety monitoring system and the like. The hydraulic system provides power for various actions of the injection molding machine according to technological process requirements, and meets the requirements of pressure, speed, position control and the like required by actions of all parts of the injection molding machine. The hydraulic system mainly comprises various hydraulic components and hydraulic auxiliary components.

With the gradual maturity of the production of domestic hydraulic component and servo motor, the traditional hydraulic drive mode has evolved from the hydraulic system of throttle remote pressure regulating to the latest servo drive hydraulic system through the technological evolution development of several generations, and for traditional hydraulic system, energy-conserving effect has had very big improvement. However, the development of hydraulic systems has so far presented problems in several respects:

1. in the aspect of control precision, (1) some hydraulic drive systems of equipment adopt an open-loop oil circuit, the open-loop oil circuit needs to adopt an open oil tank with large capacity, the capacity is large, the occupied area is large, the open oil tank is far away from an execution element, an oil pump is positioned at the open oil tank, the pipeline of the oil pump connected to an oil cylinder is very long, the total length of an oil inlet pipeline and an oil return pipeline can reach 3-20 meters and is not equal, some components are movable, the components need to be connected through hoses, due to the compressible characteristic of hydraulic oil, the hose connection has elasticity, and the pipeline is too long, an overshoot phenomenon easily occurs, and the control precision of the control system is low. (2) Meanwhile, in practical application, the dynamic load changes greatly, which also leads to lower control precision of the control system. (3) Under the condition of adopting an open-loop oil way, closed-loop control is almost impossible under the condition of being far away from a load, so the existing oil way is usually controlled in an open-loop mode, but the internal leakage of an oil pump is related to the working speed, the pressure, the oil temperature, the viscosity and the like, the oil pump runs for a long time and has the problem of internal leakage, and the accuracy of the open-loop control is limited. (4) In the prior art, a driver of a hydraulic control system receives an analog signal, and outputs a digital signal to control a servo motor to work after analog-to-digital conversion, so that the analog signal is easily interfered, the signal is easily distorted, the response is slow, and the like, and the control precision of the hydraulic control system is low.

2. In the aspect of energy saving and environmental protection, a large-capacity open oil tank is needed to be adopted for an open oil circuit, more installed hydraulic oil needs to be used for the open oil tank, a 150-ton common mode locking injection molding machine in the market is taken as an example, the installed capacity is 200 liters of wear-resistant hydraulic oil, the hydraulic oil needs to be replaced every 4000 plus 6000 hours according to the use environment of the injection molding machine, 2400 liters of hydraulic oil needs to be replaced in a working period of 12 years under the working condition of continuous 80% time working, more than one hundred thousand injection molding machines are reserved in China at present, the unit price of the wear-resistant hydraulic oil is 10-15 yuan/liter, the oil replacement is a cost which is not small for users, the cost for oil waste disposal is also needed, and the influence of waste oil treatment on the environment is also a very serious social problem.

3. In the aspect of service life, due to the adoption of the open oil tank, along with liquid level change, temperature change and high-speed flow of oil, gas, dust and moisture in the air easily enter the hydraulic oil, so that the hydraulic oil is easy to emulsify and oxidize, a hydraulic element is easy to cavitate, and the service life of the hydraulic element is shortened.

Disclosure of Invention

The invention aims to provide a precise closed oil circuit oil-electricity compound injection molding machine to solve the problems of control precision, energy conservation, environmental protection, service life and the like in the prior art.

The application provides the following technical scheme:

accurate closed oil circuit oil electricity compound injection molding machine, including control system and a plurality of closed oil circuit actuating system of group, closed oil circuit actuating system includes:

each group of hydraulic actuating mechanisms comprises a hydraulic actuating part, a reversing device and a main sensor, wherein the hydraulic actuating part comprises a first oil port and a second oil port, the reversing device is communicated with the first oil port of the corresponding hydraulic actuating part through a first oil path, and the reversing device is communicated with the second oil port of the corresponding hydraulic actuating part through a second oil path; the main sensor is used for acquiring load information capable of reflecting the motion condition of a load driven by the hydraulic execution component;

the oil pump is communicated with each reversing device through an oil return pipeline, an oil outlet of the oil pump is communicated with each reversing device through an oil inlet pipeline, and the oil pump and each group of hydraulic actuating mechanisms form a closed hydraulic oil circuit through the oil inlet pipeline and the oil outlet pipeline;

the motor is in transmission connection with the oil pump and is used for driving the oil pump;

the control system is electrically connected with the motor and the main sensor and is used for generating a control instruction according to the load information to carry out real-time closed-loop control on the motor.

Has the advantages that:

1. in the technical scheme, each group of closed oil circuit driving systems comprises a plurality of groups of hydraulic actuating mechanisms, through the reversing device, when the injection molding machine executes different actions, the corresponding reversing device is arranged, the closed oil circuit driving systems can control the different hydraulic actuating mechanisms to act in turn, when other reversing valves are closed, all the actions can not interfere with each other, namely, the plurality of groups of hydraulic actuating mechanisms share the same oil pump, the pipeline and the like, the cost is reduced, and the control is convenient to unify.

2. When the bidirectional pump closed loop is used, the static position of a piston cylinder of the oil cylinder is maintained by adjusting the positive and negative rotation of an oil pump, the motor needs to work continuously, a large amount of energy is consumed, and the mechanical position is kept safer, so that mechanical displacement cannot be caused by sudden power failure.

3. Adopt closed oil circuit in this scheme, compare in current open hydraulic pressure oil circuit, cancelled large-scale open oil tank, the hydraulic pressure executive component is no longer kept away from to the oil pump and is set up, can shorten the pipeline effectively, reduces the oil mass in the pipeline to avoided because the compressible characteristic of fluid, the elasticity that the hose connection has, and the pipeline overlength, dynamic load changes greatly, and the drawback of overshoot phenomenon appears easily. Meanwhile, load information reflecting the load condition is obtained through the main sensor, real-time closed-loop control is conducted on the motor through the control system according to the load information, the condition that control precision is affected due to overflow, oil leakage and the like of an oil way is effectively improved, the problems that movement impact vibration is not stable and position control is not accurate are solved, and the control precision is improved. Taking a hydraulic system with the mold locking force of an injection molding machine of 110 tons as an example, when the cycle period is 1.5 seconds, the repeated precision of mold opening stopping is plus or minus 0.15mm, and the repeated precision is plus or minus 2-5mm in the traditional mode; the absolute stopping precision is plus or minus 0.3mm, and the traditional open type oil way is plus or minus 5-10 mm; the injection molding machine has the advantages that the operation is stable, the impact vibration is avoided, the precision is not obviously changed under the weight of 150kg with a load, the injection molding is linear motion, the repeated control precision of the screw is 0.05mm when the injection speed is 100mm/s, and the absolute stop precision is 0.08 mm.

4. Adopt closed oil circuit in this scheme, compare in current open hydraulic oil circuit, cancelled large-scale open oil tank, consequently reduced a large amount of installation hydraulic oil, use injection molding machine clamping force as 110 tons as the example, adopt open hydraulic oil circuit, installation hydraulic oil mass is 170 liters, after this scheme of adoption, the installation oil mass is 16 liters, great saving the cost, and need not to handle a large amount of oil wastes, can not cause the influence to the environment, energy-concerving and environment-protective.

5. Adopt closed oil circuit in this scheme, gas, dust, moisture in the air are difficult to get into the hydraulic pressure oil circuit, and hydraulic oil is difficult to be emulsified and oxidation, and hydraulic component is difficult cavitation erosion also simultaneously, has prolonged hydraulic component's life.

Furthermore, an overflow pipeline is arranged between the oil inlet pipeline and the oil return pipeline, and an overflow valve is arranged on the overflow pipeline.

The overflow valve can eliminate the impact load of movement, and provides upper limit pressure regulating pressure safety protection for an oil circuit system, so that a hydraulic system is protected, and the damage of a hydraulic element caused by the generation of ultrahigh pressure when a pressure sensor fails is prevented.

Furthermore, a negative pressure compensation pipeline is arranged between the oil inlet pipeline and the oil return pipeline, and a one-way valve is arranged on the negative pressure compensation pipeline.

The arrangement of the negative pressure compensation pipeline provides a mounting position for the one-way valve, and the one-way valve is convenient to mount. When a negative load is suddenly generated in the process of pushing the load to move by the thrust, for example, when the mould is opened and the pressure is relieved in an injection molding machine, a negative pressure condition occurs in an oil inlet pipeline, the one-way valve is conducted, hydraulic oil in an oil return pipeline and a hydraulic energy accumulator enters the oil inlet pipeline to perform negative pressure oil supplement, and therefore the conditions that the oil is cut off and shakes and a hydraulic element is damaged due to the negative load are avoided.

And the hydraulic energy accumulator and the cooler are both arranged on the oil return pipeline.

The cooler is used for cooling the hydraulic oil, so that the oil temperature of the hydraulic oil is always kept within a process requirement range. The hydraulic accumulator is used for storing and releasing hydraulic oil, and taking the mold opening action of the injection molding machine as an example, because the oil return amount of a rodless cavity of the oil cylinder is greater than the oil inlet amount of a rod cavity, redundant hydraulic oil which is not needed by the oil pump can flow into the hydraulic accumulator on an oil return pipeline.

Furthermore, the reversing device is a reversing valve, the reversing valve is used for opening, closing and reversing of the closed hydraulic oil path, the reversing valve comprises four ports, two ports are respectively communicated with the oil inlet pipeline and the oil return pipeline, and the other two ports are respectively communicated with the first oil path and the second oil path.

The reversing valve is used for reversing a closed hydraulic oil path, taking a hydraulic execution part as an oil cylinder as an example, assuming that a first oil path is communicated with a rodless cavity of the oil cylinder, a second oil path is communicated with a rod cavity of the oil cylinder, when two ports of the reversing valve are communicated with an oil inlet pipeline and the first oil path, and the other two ports are communicated with an oil return pipeline and the second oil path, the rodless cavity of the oil cylinder takes oil and the rod cavity produces oil, otherwise, when the two ports of the reversing valve are communicated with the oil inlet pipeline and the second oil path, and the other two ports are communicated with the oil return pipeline and the first oil path, the rodless cavity of the oil cylinder produces oil and the rod cavity takes oil, so that the reversing of the. The hydraulic executing components can be controlled to execute different actions, and the different hydraulic executing components can also be controlled to act in turn, and the closed-loop control of pressure and speed regulation is realized.

The closed oil way driving systems are two groups and are respectively a first closed oil way driving system and a second closed oil way driving system, the first closed oil way driving system is used for driving the die closing system, and the second closed oil way driving system is used for driving the injection system.

The mold closing system and the injection system are respectively provided with independent closed oil way driving systems which are not interfered with each other, so that the stable operation of the injection molding machine is ensured.

Further, the hydraulic actuating mechanism of the first closed oil path driving system comprises a mold adjusting actuating mechanism, a mold opening and closing actuating mechanism, a thimble action actuating mechanism and an auxiliary core pulling action actuating mechanism, and the mold adjusting actuating mechanism comprises a mold adjusting reversing valve and a mold adjusting hydraulic motor; the die opening and closing actuating mechanism comprises a die opening and closing reversing valve and a die opening and closing hydraulic cylinder; the ejector pin action executing mechanism comprises an ejector pin action reversing valve and an ejector pin hydraulic cylinder, and the auxiliary core pulling action executing mechanism comprises an auxiliary core pulling action reversing valve.

The mould adjusting actuating mechanism, the mould opening and closing actuating mechanism, the ejector pin action actuating mechanism, the auxiliary core pulling action actuating mechanism and the like are used for respectively driving each technological process and action when the mould system works.

Further, the hydraulic actuating mechanism of the second closed oil path driving system comprises an injection nozzle moving actuating mechanism and an injection actuating mechanism, and the injection nozzle moving actuating mechanism comprises an injection nozzle moving reversing valve and an injection nozzle moving hydraulic cylinder; the injection executing mechanism comprises an injection reversing valve and an injection hydraulic cylinder.

The injection nozzle moving actuating mechanism, the injection actuating mechanism and the like are used for driving all the process steps of the injection system.

The oil inlet pipeline and the oil return pipeline are arranged on the oil inlet pipeline and the oil return pipeline respectively, the auxiliary sensor is used for detecting hydraulic pressure information at the position, and the control system is further used for adjusting a control command according to the pressure information.

By acquiring pressure information of a pipeline and an execution part from a sensor, such as pressure information of a rod cavity and a rodless cavity of an oil cylinder, a control system adjusts a control command according to the pressure information, and the control precision of hydraulic drive control can be further improved.

Further, the control system adopts a full-digital PID motion control algorithm to carry out real-time closed-loop control.

And a full-digital PID motion control algorithm is adopted, so that the anti-interference capability is strong, the response speed is high, and the control precision can be improved. The PID motion control algorithm is adopted for control, so that real-time closed-loop correction can be realized, and the control precision of drive control is improved.

Drawings

Fig. 1 is a schematic structural diagram of a closed oil path driving system in an embodiment of a precision closed oil path oil-electric composite injection molding machine according to the application;

FIG. 2 is a schematic three-dimensional structure diagram of a closed oil path driving system in an embodiment of the precision closed oil path oil-electric composite injection molding machine of the application;

fig. 3 is a schematic structural diagram of a first closed oil path driving system in an embodiment of the precision closed oil path oil-electric composite injection molding machine of the present application;

fig. 4 is a schematic structural diagram of a second closed oil path driving system in an embodiment of the precision closed oil path oil-electric composite injection molding machine of the present application;

fig. 5 is a schematic three-dimensional structure diagram in an embodiment of the precision closed oil path oil-electric composite injection molding machine.

Detailed Description

The following is further detailed by way of specific embodiments:

the reference numbers in the drawings of the specification include: the device comprises an oil pump 1, a motor 2, a hydraulic accumulator 3, a hydraulic execution part 4, a main sensor 5, a reversing device 6, a slave sensor 7, a cooler 8, an oil return pipeline 9, an oil inlet pipeline 10, an overflow pipeline 11, a negative pressure compensation pipeline 12, an overflow valve 13, a one-way valve 14, a second oil way 15, a first oil way 16, an oil suction port 17, an oil outlet 18, a controller 19, a servo driver 20, a mold adjusting reversing valve 21, a mold adjusting hydraulic motor 22, a mold opening and closing hydraulic cylinder 23, a mold opening and closing reversing valve 24, an ejector pin action reversing valve 25, an ejector pin hydraulic cylinder 26, an auxiliary core pulling action reversing valve 27, an injection nozzle moving reversing valve 28, an injection nozzle moving hydraulic cylinder 29, an injection reversing valve 30 and an injection hydraulic cylinder 31.

The precise closed oil way oil-electric composite injection molding machine comprises an injection system, a mold closing system, a lubricating system, a heating and cooling system, a safety monitoring system and the like, and further comprises a control system and a plurality of combined closed oil way driving systems, wherein the closed oil way driving systems are used for driving the injection system and the mold closing system to work.

As shown in fig. 1 and fig. 2, the closed oil path driving system of the present embodiment includes a plurality of sets of hydraulic actuators, an oil pump 1, a motor 2, a hydraulic accumulator 3, and a cooler 8.

Each group of hydraulic actuating mechanisms comprises a hydraulic actuating part 4, a reversing device 6 and a main sensor 5, the hydraulic actuating part 4 comprises a first oil port and a second oil port, the reversing device 6 is communicated with the first oil port of the corresponding hydraulic actuating part 4 through a first oil path 16, and the reversing device 6 is communicated with the second oil port of the corresponding hydraulic actuating part 4 through a second oil path 15; the main sensor 5 is used to acquire load information that reflects the movement of the load driven by the hydraulic actuator 4.

In this embodiment, the hydraulic actuator 4 is a hydraulic cylinder (oil cylinder) or a hydraulic motor (oil motor), the reversing device 6 is a reversing valve, the reversing valve is used for opening and closing and reversing a closed hydraulic oil path, the reversing valve includes four ports, two of the ports are respectively communicated with the oil inlet pipeline 10 and the oil return pipeline 9, and the other two ports are respectively communicated with the first oil path 16 and the second oil path 15. The reversing valve is used for reversing a closed hydraulic oil path, taking the hydraulic execution part 4 as an oil cylinder as an example, assuming that the first oil path 16 is communicated with a rodless cavity of the oil cylinder, the second oil path 15 is communicated with a rod cavity of the oil cylinder, when two ports of the reversing valve are communicated with the oil inlet pipeline 10 and the first oil path 16, and the other two ports are communicated with the oil return pipeline 9 and the second oil path 15, the rodless cavity of the oil cylinder takes oil in and the rod cavity takes oil out, otherwise, when the two ports of the reversing valve are communicated with the oil inlet pipeline 10 and the second oil path 15, and the other two ports are communicated with the oil return pipeline 9 and the first oil path 16, the rodless cavity of the oil cylinder takes oil out and the rod cavity takes oil in, thereby realizing. The hydraulic executive component 4 can be controlled to execute different actions, and different hydraulic executive components 4 can be controlled to act in turn, and closed-loop control of pressure and speed regulation is realized.

The main sensor 5 is installed on the hydraulic execution part 4, specifically, a built-in displacement sensor, an external displacement sensor, a rotary sensor and the like can be adopted, in this embodiment, the main sensor 5 is an external magnetic linear displacement sensor, the main sensor 5 comprises an electronic chamber, a waveguide ruler and a movable magnetic ring, the electronic chamber is connected with the waveguide ruler, the movable magnetic ring is sleeved on the waveguide ruler, for example, the main sensor is installed on an oil cylinder, when the main sensor is installed, the displacement sensor is installed on a mold locking tail plate of an injection molding machine and is fixed relative to the oil cylinder, and the magnetic ring can move on the waveguide ruler and synchronously move with a piston rod through a connecting rod. In other embodiments, the main sensor 5 is a built-in magneto linear displacement sensor, the electronic chamber is fixedly connected with the outer side of the cylinder body, the waveguide tube is parallel to the outer side of the cylinder body, and the movable magnetic ring is connected with the piston rod, namely when the piston rod moves, the movable magnetic ring moves on the waveguide tube along with the piston rod. In another embodiment, the piston rod is connected with the rack, the gear is driven to drive the rotary encoder when in motion, the linear motion is converted into the rotary motion, the angle information is obtained, and the linear movement position and speed are obtained through the rotation information. The real-time position signal is fed back to the control system to obtain position and velocity signals.

An oil suction port 17 of the oil pump 1 is communicated with each reversing device 6 through an oil return pipeline 9, an oil outlet 18 of the oil pump 1 is communicated with each reversing device 6 through an oil inlet pipeline 10, and the oil pump 1 and each group of hydraulic actuating mechanisms form a closed hydraulic oil way through the oil inlet pipeline 10 and the oil outlet pipeline;

the motor 2 is in transmission connection with the oil pump 1, and the motor 2 is used for driving the oil pump 1; specifically, an output shaft of the motor 2 is in keyed connection with an input shaft of the oil pump 1, in this embodiment, the motor 2 adopts the synchronous servo motor 2, the oil pump 1 adopts a fixed displacement pump, the oil pump 1 is one of a gear pump, a screw pump, a plunger pump, a vane pump and the like, and the gear pump is selected in this embodiment.

The hydraulic accumulator 3 is arranged on the return line 9 for storing and releasing hydraulic oil. The cooler 8 is arranged on the oil return pipeline 9 and used for cooling the hydraulic oil, so that the oil temperature of the hydraulic oil is always kept within the process requirement range.

In this embodiment, the closed oil path driving systems are two sets, which are respectively a first closed oil path driving system and a second closed oil path driving system, where the first closed oil path driving system is used to drive the mold closing system, and the second closed oil path driving system is used to drive the injection system. The mold closing system and the injection system are respectively provided with independent closed oil way driving systems which are not interfered with each other, so that the stable operation of the injection molding machine is ensured.

As shown in fig. 3 and 5, the hydraulic actuator of the first closed oil path driving system includes a mold adjusting actuator, a mold opening and closing actuator, an ejector pin actuation actuator, and an auxiliary core pulling actuation actuator, and the mold adjusting actuator includes a mold adjusting reversing valve 21 and a mold adjusting hydraulic motor 22; the mold opening and closing actuating mechanism comprises a mold opening and closing reversing valve 24 and a mold opening and closing hydraulic cylinder 23; the ejector pin action executing mechanism comprises an ejector pin action reversing valve 25 and an ejector pin hydraulic cylinder 26, and the auxiliary core pulling action executing mechanism comprises an auxiliary core pulling action reversing valve 27. The mould adjusting actuating mechanism, the mould opening and closing actuating mechanism, the ejector pin action actuating mechanism, the auxiliary core pulling action actuating mechanism and the like are used for respectively driving each technological process and action when the mould system works.

As shown in fig. 4 and 5, the hydraulic actuator of the second closed oil path drive system includes an injection nozzle movement actuator and an injection actuator, and the injection nozzle movement actuator includes an injection nozzle movement direction switching valve 28 and an injection nozzle movement hydraulic cylinder 29; the injection actuator includes an injection selector valve 30 and an injection cylinder 31. The injection nozzle moving actuating mechanism, the injection actuating mechanism and the like are used for driving all the process steps of the injection system.

An overflow pipeline 11 is arranged between the oil inlet pipeline 10 and the oil return pipeline 9, and an overflow valve 13 is arranged on the overflow pipeline 11. A negative pressure compensation pipeline 12 is also arranged between the oil inlet pipeline 10 and the oil return pipeline 9, and a one-way valve 14 is arranged on the negative pressure compensation pipeline 12. The overflow valve 13 is set to be slightly higher than the rated highest working pressure value, when high-pressure impact load occurs in a system oil path or the pressure is out of control due to system pressure sensor failure, hydraulic oil can return to the oil return pipeline 9 through the overflow valve 13, the impact load can be resisted, the oil pump 1 is protected, meanwhile, the condition that ultrahigh pressure is generated when the pressure sensor fails to cause damage to elements is prevented, and upper-limit pressure-regulating safety protection is provided for an oil path system.

The arrangement of the negative pressure compensation pipeline 12 provides an installation position for the check valve 14, and facilitates the installation of the check valve 14. During normal operation, hydraulic oil cannot flow to the oil return pipeline 9 through the one-way valve 14, but when negative load suddenly occurs in the process of pushing load movement, for example, when die sinking pressure relief in an injection molding machine occurs and instantaneous high-pressure load pushes a piston of an oil cylinder to cause negative pressure stall, return oil of the hydraulic energy accumulator 3 and the oil cylinder can be timely supplemented into the oil inlet pipeline 10 through the automatically opened one-way valve 14 and supplemented into an oil inlet cavity of the oil cylinder through the reversing valve and the first oil way 16, so that the oil cylinder can continuously operate without impact, pause and shake, a control system cannot generate wrong overshoot due to transient negative pressure, and the control accuracy and the service life of a servo system are improved.

The system further comprises a slave sensor 7, wherein the slave sensor 7 is arranged on the oil inlet pipeline 10 and the oil return pipeline 9, and the slave sensor 7 is used for detecting the pressure information of the hydraulic pressure at the position. The number and the installation position of the slave sensors 7 can be selected according to requirements, in the embodiment, the slave sensors 7 are pressure sensors, and the slave sensors 7 are installed between the oil inlet pipeline 10 and the reversing valve. Specifically, the number of the slave sensors 7 is one, each slave sensor 7 comprises a sensing end, and the sensing ends are installed between the oil inlet pipeline 10 and the reversing valve and used for detecting the pressure at the interface of the reversing valve. In other embodiments, the number of the slave sensors 7 is two, and the slave sensors 7 are respectively installed on the oil inlet pipeline 10 and the oil return pipeline 9 and respectively used for detecting the pressure at two ends of the first oil port and the second oil port of the hydraulic actuator 4.

The control system is electrically connected with the motor 2, the main sensor 5 and the reversing device 6, the control system is used for generating a control instruction according to the load information to carry out real-time closed-loop control on the motor 2, and the control system is also used for switching the conduction state of the reversing device 6. The control system is also used for adjusting the control instruction according to the pressure information. In the implementation, the control system adopts a full-digital PID motion control algorithm to carry out real-time closed-loop control. In this embodiment, the control system includes an upper controller 19 and a servo driver 20, the upper controller 19 is connected to the servo driver 20, and the servo driver 20 is electrically connected to the motor 2. The control system adopts a full-digital PID motion control algorithm, has strong anti-interference capability and high response speed, and can improve the control precision. The PID motion control algorithm is adopted for control, so that real-time closed-loop correction can be realized, and the control precision of drive control is improved.

The control system is used for automatically generating a smooth continuous speed curve according to the preset end position and end speed of a starting stage, the end position and end speed of a running stage, the end position and load information of a tail end stage, generating a control command according to the continuous speed curve and controlling the motor 2 through the control command. The control system is also used for generating a deceleration curve by adopting a position closed-loop algorithm at the tail end stage through load information detected by the main sensor 5 in real time and speed change according to a continuous speed curve, and adjusting a control instruction in a closed-loop mode according to pressure information detected in real time.

Taking the working process of the first closed oil circuit system as an example, the main sensor 5 is used for acquiring movement information of the oil cylinder and transmitting the movement information to the controller 19, that is, sending the movement information to the control subsystem, and the auxiliary sensor 7 is used for acquiring pressure information of the oil cylinder and transmitting the pressure information to the controller 19, that is, sending the pressure information to the control subsystem. The control subsystem is used for generating a control instruction according to the movement information and adjusting the control instruction according to the pressure information, wherein the control instruction comprises a rotating speed and a torque. The control subsystem is also arranged to send control commands to the drive, i.e. the controller 19 transmits control commands to the drive, which controls the operation of the motor 2 in accordance with the control commands.

The load motion process is divided into a starting stage, an operating stage and a tail end stage, and the initial state is that the end point position and the end point speed in the starting stage, the speed of the middle point position in the operating stage and the end point stop position in the tail end stage are manually set. The control subsystem is used for generating a control command according to the end position and the end speed in the starting stage, the end position and the end speed in the running stage, the end position in the tail end stage and the movement information, specifically and automatically generating a completely smooth continuous speed curve command, generating the control command according to the speed curve, and controlling the motor 2 through the control command so as to ensure that the speed control process runs stably, continuously and without impact. The control subsystem is also used for adjusting a control instruction according to the pressure information, particularly adopting a position closed-loop algorithm at the tail end stage, detecting position and speed change in real time, generating a deceleration curve and adjusting the control instruction according to the actually detected pressure information in a high-speed closed-loop manner, so that the stop position is accurate and has no impact, the control requirement is different from the requirement of mode locking motion control, for the injection molding action, the required execution speed completely follows the set requirement, and smooth and quick speed switching transition is provided only when the segmented injection molding is changed, so as to reduce the speed mutation and the shearing picture in the filling process, generally, the injection molding action needs pressure and speed double-loop control, after the system is adopted, the conventional speed-priority double closed-loop or pressure-priority double closed-loop working mode can be selected according to the actual production requirement of a user, and the filling defect caused by the, the upper computer controller 19 of the injection molding machine and the servo driver 20 cooperate to recognize states and operate in different algorithm modes when different actions perform motion control, so as to obtain an optimal operation state.

The above are merely examples of the present invention, and the present invention is not limited to the field related to this embodiment, and the common general knowledge of the known specific structures and characteristics in the schemes is not described herein too much, and those skilled in the art can know all the common technical knowledge in the technical field before the application date or the priority date, can know all the prior art in this field, and have the ability to apply the conventional experimental means before this date, and those skilled in the art can combine their own ability to perfect and implement the scheme, and some typical known structures or known methods should not become barriers to the implementation of the present invention by those skilled in the art in light of the teaching provided in the present application. It should be noted that, for those skilled in the art, without departing from the structure of the present invention, several changes and modifications can be made, which should also be regarded as the protection scope of the present invention, and these will not affect the effect of the implementation of the present invention and the practicability of the patent. The scope of the claims of the present application shall be determined by the contents of the claims, and the description of the embodiments and the like in the specification shall be used to explain the contents of the claims.