Energy-saving hydraulic system of casting machine

Abstract

The utility model discloses an energy -saving casting machine hydraulic system belongs to casting machine technical field. The system includes servo motor, motor controller, hydraulic pump, centralized oil supply main pipe, branch oil circuit, oil return pipeline, pressure sensor and energy accumulator. Servo motor direct drive hydraulic pump, and energy accumulator is connected on the centralized oil supply main pipe between the hydraulic pump export and each branch oil circuit. Pressure sensor detects the main pipe pressure and is fed back to motor controller, and the rotation speed of servo motor is dynamically adjusted by controller, realizes the oil supply according to demand. The system can reduce energy loss, maintains system pressure stable, and effectively controls hydraulic oil temperature.

Description

Technical Field

[0001] This utility model relates to the field of casting and forming technology, specifically to an energy-saving hydraulic system for casting machines. Background Technology

[0002] The hydraulic system is the core power unit of a foundry machine, and its performance directly affects casting quality, production efficiency, and energy consumption. Currently, traditional foundry machines generally use a hydraulic system scheme where an asynchronous motor drives a fixed displacement pump. In this scheme, the asynchronous motor operates at a constant speed, driving the fixed displacement pump to output a constant flow rate. When the required flow rate or pressure of the system changes, excess hydraulic oil is mainly discharged back to the oil tank through an overflow valve to achieve pressure regulation and stabilization.

[0003] This traditional approach has the following drawbacks:

[0004] Significant energy loss and excessively high oil temperature: Due to the constant speed operation of the motor and the changing demands of the actuator, a large amount of excess oil overflows through the relief valve most of the time. This overflow process converts almost all the energy of the high-pressure hydraulic oil into heat energy, resulting in increased system energy consumption.

[0005] Large system pressure fluctuations affect casting accuracy: In scenarios where multiple casting machines operate in parallel via a centralized oil supply manifold, the start and stop of any single casting machine will generate severe pressure shocks and fluctuations (typically exceeding ±5%) in the main pipeline. This pressure instability is directly transmitted to each actuator, leading to inaccurate mold closing, injection, and other actions, severely affecting the dimensional accuracy and internal quality of the castings. Utility Model Content

[0006] (I) Technical Solution

[0007] To solve the above-mentioned technical problems, this utility model provides an energy-saving hydraulic system for casting machines.

[0008] The specific technical solution is as follows: an energy-saving hydraulic system for a casting machine, comprising a servo motor, a motor controller, a hydraulic pump, a centralized oil supply main, several branch oil circuits, a return oil pipe, a pressure sensor, and an accumulator; the servo motor drives the hydraulic pump to circulate hydraulic oil; the branch oil circuits are connected to the centralized oil supply main to supply hydraulic oil to the corresponding casting machine; the return oil pipe is used to guide the hydraulic oil in the casting machine into the oil tank; the accumulator is connected to the centralized oil supply main and is used to balance the pressure of the centralized oil supply main, and its installation position is located between the outlet of the hydraulic pump and the inlet of the branch oil circuit; the pressure sensor is used to detect the hydraulic pressure of the centralized oil supply main, and the pressure sensor is electrically connected to the motor controller, which adjusts the speed of the servo motor according to the pressure value of the centralized oil supply main.

[0009] Furthermore, the accumulator includes a tank body, inside which is a bladder for filling with nitrogen gas. The bladder body is provided with a gas valve extending from the top of the tank body. The bottom of the tank body is provided with a hydraulic oil interface and a rubber support ring. The rubber support ring is used to support the expanding bladder body. The hydraulic oil interface includes a valve port and a mushroom valve. The mushroom valve can float up and down along the valve port, and the diameter of the valve port gradually increases from bottom to top.

[0010] Furthermore, it also includes a heat exchanger comprising two independent hydraulic oil channels that exchange heat with each other, one of which is connected to an accumulator and the other is connected to a return pipe.

[0011] Furthermore, the servo motor's shaft is directly connected to the hydraulic pump to drive its operation.

[0012] Furthermore, a flow meter is also installed on the centralized oil supply main.

[0013] (ii) Beneficial effects

[0014] The servo motor and accumulator of this utility model are designed in synergy. The system adopts an on-demand oil supply mode, which reduces energy loss. The working temperature of the hydraulic oil is controlled to a certain extent, which helps to extend the service life of the oil and seals. The introduction of the accumulator effectively absorbs the system pressure fluctuations and improves the pressure stability, thereby ensuring the accuracy of casting operations. At the same time, the system operating noise is significantly reduced and the dynamic response speed is fast, which can meet the stability and responsiveness requirements of multiple casting machines working in parallel. Attached Figure Description

[0015] To more clearly illustrate the technical solutions in the embodiments of this utility model, the drawings used in the description of the embodiments or the prior art will be briefly introduced below. Obviously, the drawings described below are only some embodiments of this utility model. For those skilled in the art, other drawings can be obtained based on these drawings without creative effort.

[0016] Figure 1 This is a schematic diagram of the structure of this utility model.

[0017] Figure 2 This is a schematic diagram of the energy storage device in this utility model. Detailed Implementation

[0018] The technical solutions of the present utility model will be clearly and completely described below with reference to the accompanying drawings of the embodiments. The described embodiments are only some embodiments of the utility model, not all embodiments. Based on the embodiments of the utility model, all other embodiments obtained by those skilled in the art without creative effort are within the scope of protection of the utility model.

[0019] The energy-saving casting machine hydraulic system of this application embodiment is as follows: Figure 1 As shown, it mainly includes a servo motor 7, a motor controller 6, a hydraulic pump 9, a centralized oil supply main pipe 3, several branch oil lines 10, a return oil pipe 4, a pressure sensor 8, and an accumulator 1.

[0020] The servo motor 7 is the main power source. Its output shaft is directly connected to the input shaft of the hydraulic pump 9 via a flange. That is, the rotating shaft of the servo motor 7 is directly inserted into the shaft hole of the hydraulic pump 9, and the torque is transmitted through splines or interference fit, eliminating the need for traditional couplings, thereby improving transmission efficiency and response speed. The servo motor 7 is precisely controlled by the motor controller 6.

[0021] The outlet of hydraulic pump 9 is connected to the centralized oil supply main pipe 3. Multiple branch oil lines 10 are connected to the centralized oil supply main pipe 3, each supplying pressurized oil to a casting machine via a control valve assembly. After performing work in each casting machine, the hydraulic oil flows back to the oil tank through the return oil pipe 4. To monitor the system flow rate, a flow meter can be added to the centralized oil supply main pipe 3 for real-time monitoring of the total oil supply.

[0022] Accumulator 1 is the system's pressure stabilizing component. It is connected in parallel via pipelines to the central oil supply main 3 between the outlet of hydraulic pump 9 and the inlets of all branch oil lines 10, forming the system's primary pressure buffer node. Pressure sensor 8 is also installed on the central oil supply main 3 to detect the pressure value of the main pipeline in real time. Pressure sensor 8 is electrically connected to motor controller 6, feeding back the pressure signal to motor controller 6. Motor controller 6 compares the set target pressure value (e.g., 100 bar) with the actual pressure value fed back by pressure sensor 8, dynamically adjusting the speed of servo motor 7, thereby changing the output flow of hydraulic pump 9, achieving on-demand flow supply and stable pressure control.

[0023] In a preferred embodiment of this utility model, the energy accumulator 1 adopts an airbag structure. For example... Figure 2 As shown, it includes a tank 1.2, inside which is a flexible bladder 1.3. The bladder is pre-filled with nitrogen gas at a certain pressure through a gas valve 1.1 at the top. A hydraulic oil interface is located at the bottom of the tank 1.2, with a mushroom valve 1.4 and a valve port 1.6. When the system pressure is higher than the nitrogen pressure inside the bladder, hydraulic oil opens the mushroom valve and enters the tank, compressing the bladder to store energy; when the system pressure drops, the bladder expands, pushing the oil out. The diameter of the valve port 1.6 is designed to gradually increase from bottom to top, facilitating smooth oil flow and reducing impact on the bladder. Furthermore, a rubber support ring 1.5 is located at the bottom of the tank to provide support when the bladder is fully inflated, preventing it from violently colliding with the tank bottom and extending its service life.

[0024] To further optimize the system's thermal management, this embodiment can also integrate a heat exchanger 5. This heat exchanger 5 has two completely independent, non-interconnected hydraulic oil channels. One channel is connected to the return oil line of the accumulator 1, and the other channel is connected in series in the system's return oil pipeline 4. The two channels exchange heat through their metal walls. For example, the relatively cooler accumulator return oil flows through one channel, while the warmer system main return oil flows through the other channel. The two exchange heat through the walls, thereby cooling the system return oil and preheating the accumulator return oil, forming a highly efficient built-in energy recovery system and reducing reliance on external cooling.

[0025] The working principle of this utility model is as follows:

[0026] During system operation, the motor controller 6 controls the servo motor 7 to operate as needed based on the signal from the pressure sensor 8. When the casting machine is not in operation or the required flow rate is small, the servo motor 7 runs at low speed or stops. At this time, the accumulator 1 replenishes the system with pressurized oil to maintain pressure stability. When the casting machine is in operation and requires a large flow rate, the accumulator 1 can instantly release the stored oil, and at the same time, the motor controller 6 instructs the servo motor 7 to accelerate, jointly meeting the flow rate requirement. This process eliminates the energy consumption and heat generated by releasing high-pressure oil through the overflow valve in traditional systems. At the same time, the accumulator 1 effectively absorbs pressure fluctuations, achieving a comprehensive effect of energy saving, pressure stabilization, and noise reduction.

[0027] The above are merely preferred embodiments of this utility model and are not intended to limit the scope of this utility model. Various modifications and variations can be made to this utility model by those skilled in the art. Any modifications, equivalent substitutions, or improvements made within the spirit and principles of this utility model should be included within the protection scope of this utility model.

Claims

1. An energy-saving hydraulic system for a casting machine, characterized in that: The system includes a servo motor, a motor controller, a hydraulic pump, a centralized oil supply main, several branch oil circuits, a return oil pipeline, a pressure sensor, and an accumulator. The servo motor drives the hydraulic pump to flow hydraulic oil. The branch oil circuits are connected to the centralized oil supply main to supply hydraulic oil to the corresponding casting machines. The return oil pipeline is used to guide the hydraulic oil in the casting machine into an oil tank. The accumulator is connected to the centralized oil supply main and is used to balance the pressure of the centralized oil supply main. Its installation position is between the outlet of the hydraulic pump and the inlet of the branch oil circuit. The pressure sensor is used to detect the hydraulic pressure of the centralized oil supply main. The pressure sensor is electrically connected to the motor controller, and the motor controller adjusts the speed of the servo motor according to the pressure value of the centralized oil supply main.

2. The energy-saving hydraulic system for a casting machine according to claim 1, characterized in that: The accumulator includes a tank, inside which is a bladder for filling with nitrogen. The bladder is equipped with a gas valve extending from the top of the tank. The bottom of the tank is equipped with a hydraulic oil interface and a rubber support ring. The rubber support ring is used to support the expanding bladder. The hydraulic oil interface includes a valve port and a mushroom valve. The mushroom valve can float up and down along the valve port, and the diameter of the valve port gradually increases from bottom to top.

3. The energy-saving hydraulic system for a casting machine according to claim 2, characterized in that: It also includes a heat exchanger, which comprises two independent hydraulic oil passages that exchange heat with each other, one of which is connected to an accumulator and the other is connected to a return pipe.

4. The energy-saving casting machine hydraulic system according to claim 3, characterized in that: The servo motor's shaft is directly connected to the hydraulic pump, driving its operation.

5. The energy-saving hydraulic system for a casting machine according to claim 4, characterized in that: A flow meter is also installed on the centralized oil supply main.

Images