Micro-ejection oil way structure for injection molding machine

Abstract

The utility model provides a micro-ejection oil path structure for an injection molding machine, which can realize precise flow control and is low in cost. Comprising an ejection oil way plate and a main oil way plate, the ejection oil way plate is installed on an ejection oil cylinder, the ejection oil way plate comprises a proportional flow direction valve, and the main oil way plate comprises a safety valve, a filter, a storage electromagnetic valve, a proportional back pressure valve, an overflow valve, a one-way valve and a throttling one-way valve. The main oil circuit board is provided with a main oil outlet IFP, a main oil return port IFT, an oil return port IF1, an oil motor oil inlet SP, a loosening and retreating port IB1, an oil motor oil return port ST, an oil tank inlet T, an oil pump oil inlet P and a cooling port CT; an injection oil inlet IFP1, an injection oil return port IFT1, an injection oil outlet IF and an oil outlet IB are formed in the injection oil way plate; two working ports of the proportional flow direction valve are correspondingly connected to the injection oil outlet IF and the oil outlet IB, and the other two working ports of the proportional flow direction valve are correspondingly connected to the injection oil inlet IFP1 and the injection oil return port IFT1.

Description

Technical Field

[0001] The utility model relates to the technical field of injection molding machines, in particular to a micro injection oil circuit structure for an injection molding machine. Background Art

[0002] An injection molding machine is a commonly used plastic molding machine, mainly including an injection system, a mold clamping system, a drive system and a control system. These systems cooperate with each other to complete the molding of plastic parts. Among them, the injection oil circuit mechanism is an important part of the injection system. However, the existing injection oil circuit mechanism realizes flow control by purchasing imported motors, which requires additional components (such as lead screws, synchronous belts, etc.) to be assembled and work together. Not only is the purchase price relatively high, but the maintenance cost is also high. Moreover, the traditional hydraulic press is connected to the injection cylinder through a 1-2 meter long oil pipe. Since pressure loss will occur during the transmission of oil in the oil pipe, it will affect the injection accuracy. Especially in the case of products with good fluidity, such as silicone products, once the back pressure is not controlled, it will cause unsuccessful material storage or inaccurate material storage position, thus unable to meet the requirements of micro injection, and also unable to meet the production and process requirements of high-precision electronic components and thin-walled products. Content of the Utility Model

[0003] Aiming at the above problems, the utility model provides a micro injection oil circuit structure for an injection molding machine, which can realize precise flow control and has low cost.

[0004] The utility model adopts the following technical solution. A micro injection oil circuit structure for an injection molding machine includes an injection oil circuit board and a main oil circuit board. The injection oil circuit board is installed on an injection cylinder. It is characterized in that: the injection oil circuit board includes a proportional flow direction valve; the main oil circuit board includes a safety valve, a filter, a metering solenoid valve, a proportional back pressure valve, an overflow valve, a check valve, and a throttle check valve. The main oil circuit board has a main oil outlet IFP, a main oil return port IFT, an oil return port IF1, an oil motor inlet SP, a retraction port IB1, an oil motor oil return port ST, a fuel tank inlet T, a fuel pump inlet P, and a cooling port CT; the injection oil circuit board has an injection oil inlet IFP1, an injection oil return port IFT1, an injection oil outlet IF, and an oil outlet IB; the injection oil inlet IFP1 and the injection oil return port IFT1 are respectively connected to the main oil outlet IFP and the main oil return port IFT; two working ports of the proportional flow direction valve are correspondingly connected to the injection oil outlet IF and the oil outlet IB, and the other two working ports of the proportional flow direction valve are correspondingly connected to the injection oil inlet IFP1 and the injection oil return port IFT1. The oil return port IF1 and the injection oil outlet IF are both communicated with the injection chamber of the injection cylinder, and the retraction port IB1 and the oil outlet IB are both communicated with the retraction chamber of the injection cylinder; the filter is connected between the main oil outlet IFP and the fuel pump inlet P, the safety valve is connected between the fuel pump inlet P and the cooling port CT, two working ports of the metering solenoid valve are correspondingly connected to the oil return port IF1 and the oil motor inlet SP, and the other two working ports of the metering solenoid valve are correspondingly connected to the fuel pump inlet P and one end of the proportional back pressure valve. The other end of the proportional back pressure valve is connected to both the main oil return port IFT and the cooling port CT. One end of the check valve is connected to one end of the overflow valve and then connected to the fuel tank inlet T. The other end of the overflow valve is connected to one end of the throttle check valve and then connected to the oil motor oil return port ST. The other end of the throttle check valve is connected to the other end of the check valve and then connected to the retraction port IB1.

[0005] Further, the metering solenoid valve adopts a two-position two-way valve; the proportional flow direction valve adopts a three-position four-way valve; the fuel pump inlet P is connected to a fuel pump, and the fuel pump is connected to a hydraulic servo motor;

[0006] Further, an oil circuit block is installed outside the injection cylinder. The proportional flow direction valve is installed on the oil circuit block. Two oil channels are provided in the oil circuit block. Two working ports of the proportional flow direction valve are correspondingly connected to the two oil channels. The two oil channels are correspondingly connected to the injection port and the retraction port of the injection cylinder.

[0007] The beneficial effects of the present utility model are as follows: A proportional flow direction valve is assembled on the injection oil cylinder, which not only has low cost, but also can reduce the pressure and flow loss of the oil circuit in the pipeline and precisely control the injection speed through the control of the proportional flow direction valve, thereby facilitating the precise control of pressure and flow, meeting the production requirements of micro products, and having good economic value in use. Brief Description of the Drawings

[0008] Figure 1 is the oil circuit schematic diagram of the present utility model;

[0009] Figure 2 is the structural schematic diagram of the present utility model;

[0010] Figure 3 is the connection schematic diagram of the main oil circuit board in the present utility model. Detailed Embodiment

[0011] Such as Figure 1 、 Figure 2 、 Figure 3As shown in the figure, a micro-injection oil circuit structure for an injection molding machine of the present utility model includes an injection oil circuit board 1 and a main oil circuit board 2. The injection oil circuit board 1 is installed on the injection cylinder 3, and the main oil circuit board 2 is installed on the fuel tank of the injection molding machine (not shown in the figure). The injection oil circuit board 1 includes a proportional flow direction valve 4. The main oil circuit board 2 includes a safety valve 5, a filter 6, a metering solenoid valve 7, a proportional back pressure valve 8, a relief valve 9, a check valve 10, and a throttle check valve 11. The main oil circuit board 2 has a main oil outlet IFP, a main oil return port IFT, an oil return port IF1, an oil motor inlet SP (for connecting the feeding oil motor), a retreat port IB1, an oil motor oil return port ST, a fuel tank inlet T, a fuel pump inlet P, and a cooling port CT (for returning oil to the cooler). The injection oil circuit board 1 has an injection oil inlet IFP1, an injection oil return port IFT1, an injection oil outlet IF, and an oil outlet IB. The injection oil inlet IFP1 and the injection oil return port IFT1 are respectively connected to the main oil outlet IFP and the main oil return port IFT. Two working ports of the proportional flow direction valve 4 are correspondingly connected to the injection oil outlet IF and the oil outlet IB, and the other two working ports of the proportional flow direction valve 4 are correspondingly connected to the injection oil inlet IFP1 and the injection oil return port IFT1. The oil return port IF1 and the injection oil outlet IF are both communicated with the injection chamber 12 of the injection cylinder 3, and the retreat port IB1 and the oil outlet IB are both communicated with the retreat chamber 13 of the injection cylinder 3, that is, the injection oil outlet IF is communicated with the injection chamber 12 through the injection port 15, and the oil outlet IB is communicated with the retreat chamber 13 through the retreat port 16. The filter 6 is connected between the main oil outlet IFP and the fuel pump inlet P. The safety valve 5 is connected between the fuel pump inlet P and the cooling port CT. Two working ports of the metering solenoid valve 7 are correspondingly connected to the oil return port IF1 and the oil motor inlet SP, and the other two working ports of the metering solenoid valve 7 are correspondingly connected to the fuel pump inlet P and one end of the proportional back pressure valve 8. The other end of the proportional back pressure valve 8 is connected to both the main oil return port IFT and the cooling port CT. One end of the check valve 10 is connected to one end of the relief valve 9 and then connected to the fuel tank inlet T. The other end of the relief valve 9 is connected to one end of the throttle check valve 11 and then connected to the oil motor oil return port ST. The other end of the throttle check valve 11 is connected to the other end of the check valve 10 and then connected to the retreat port IB1.

[0012] The proportional flow direction valve 4 adopts a three-position four-way valve. An oil circuit block 14 is installed outside the injection cylinder 3, and the proportional flow direction valve 4 is installed on the oil circuit block 14. Two oil channels (not shown in the figure) are provided in the oil circuit block 14. Two working ports of the proportional flow direction valve 4 are correspondingly connected to the two oil channels, and the two oil channels are correspondingly connected to the injection port 15 and the retreat port 16 of the injection cylinder 3.

[0013] The working principle of the present utility model is:

[0014] During the injection operation of the injection cylinder 3, the working port at the injection end of the proportional flow direction valve 4 is energized, the working port at the retraction end of the proportional flow direction valve 4 is de-energized, and the material storage solenoid valve 7 is de-energized;

[0015] During the retraction operation of the injection cylinder 3, the working port at the retraction end of the proportional flow direction valve 4 is energized, the working port at the injection end of the proportional flow direction valve 4 is de-energized, and the material storage solenoid valve 7 is de-energized;

[0016] During the material storage operation, the material storage solenoid valve 7 is energized, and the working ports at the injection end and the retraction end of the proportional flow direction valve 4 are both de-energized;

[0017] During different operations, the proportional flow direction valve 4 and the material storage solenoid valve 7 are energized or de-energized according to the above operations. It should be noted that the proportional backpressure valve 8 is preset proportionally according to the situation, and the proportional backpressure valve 8 is only energized during the retraction or material storage operation.

[0018] In the present utility model, the hydraulic servo motor 17 (an existing device used) is connected to the oil pump inlet P through the oil pump 18. Then, the hydraulic servo motor 17 transports the oil fluid to the oil circuit of the main oil circuit board 2 through the oil pump 18. Through the filter 6 connected between the injection oil circuit board 1 and the main oil circuit board 2, the cleanliness of the hydraulic pressure can be ensured, and the mobility of the proportional flow direction valve 4 can be improved; a pressure sensor (not shown in the figure) can be installed at the oil pump inlet P. The pressure sensor can feed back the pressure signal in real time. Once the pressure sensor detects that the pressure value reaches the set value, the hydraulic servo motor will reverse and decelerate to maintain the voltage stabilization effect of the set pressure. When it is detected that the pressure value exceeds the set value, the excess-pressure hydraulic oil will return to the fuel tank through the fuel tank inlet T through the overflow valve 9, so as to stabilize the pressure at the set value.

[0019] The proportional flow direction valve 4 adopted in the present utility model precisely controls its own valve displacement through a 0-10V analog quantity, so that the oil inflow and outflow in the injection chamber 12 and the retraction chamber 13 of the injection cylinder 3 are more precise; due to the gravity of the core shaft of the injection cylinder 3 itself, for plastics with good fluidity and low viscosity, such as silicone materials, no backpressure is required during the production process; the oil replenishment amount for the retraction chamber can be adjusted through the throttle check valve 11 to overcome the mechanical gravity; the material storage solenoid valve 7 adopts an ordinary two-position two-way valve. When the material storage solenoid valve 7 is energized, the retraction chamber 13 will suck oil from the fuel tank through the one-way valve 10 (installing the one-way valve 10 can avoid sucking in air or creating a vacuum), and at the same time, replenish oil to the retraction chamber 13 through the oil motor return port ST. Among them, before starting the machine, the oil replenishment amount can be manually preset according to the situation by adjusting the overflow valve 9 and the throttle check valve 11; the oil fluid in the injection chamber 12 passes through the material storage solenoid valve 7 and the proportional backpressure valve 8 in sequence and then returns to the cooler through the cooling port CT.

[0020] In summary, the present utility model precisely controls the injection speed by using a proportional flow direction valve 4, and precisely controls the injection pressure through a hydraulic servo motor. This not only reduces the pressure and flow losses of the oil circuit in the pipeline, but also has a low cost, achieves the control precision of pressure and speed, and combines with the zero-gravity oil circuit design and precise proportional backpressure control, thereby realizing the molding of micro products.

[0021] For those skilled in the art, it is obvious that the present utility model is not limited to the details of the above-described exemplary embodiments, and can be implemented in other specific forms without departing from the spirit or basic characteristics of the present utility model. Therefore, from any point of view, the embodiments should be regarded as exemplary and non-restrictive. The scope of the present utility model is defined by the appended claims rather than the above description. Therefore, all changes falling within the meaning and scope of the equivalent elements of the claims are intended to be included in the present utility model. Any reference signs in the claims should not be construed as limiting the claimed rights.

[0022] In addition, it should be understood that although this specification is described in terms of embodiments, not every embodiment only contains an independent technical solution. This narrative way of the specification is only for clarity. Those skilled in the art should regard the specification as a whole, and the technical solutions in each embodiment can also be appropriately combined to form other embodiments that can be understood by those skilled in the art.

Claims

1. A micro injection oil circuit structure for an injection molding machine, comprising an injection oil circuit board and a main oil circuit board, wherein the injection oil circuit board is mounted on an injection oil cylinder, and is characterized in that: The injection oil circuit board includes a proportional flow direction valve, the main oil circuit board includes a safety valve, a filter, a storage solenoid valve, a proportional back pressure valve, a relief valve, a check valve, and a throttling check valve. The main oil circuit board has a main oil outlet IFP, a main oil return port IFT, an oil return port IF1, an oil motor oil inlet SP, a release port IB1, an oil motor oil return port ST, a tank inlet T, an oil pump oil inlet P, and a cooling port CT; the injection oil circuit board has an injection oil inlet IFP1, an injection oil return port IFT1, an injection oil outlet IF, and an oil outlet IB; the injection oil inlet IFP1 and the injection oil return port IFT1 are respectively connected to the main oil outlet IFP and the main oil return port IFT; two of the working ports of the proportional flow direction valve are correspondingly connected to the injection oil outlet IF and the oil outlet IB, and the other two working ports of the proportional flow direction valve are correspondingly connected to the injection oil inlet IFP1 and the injection oil return port IFT1, and the oil return port IF1 and the injection oil outlet IF are both connected to the injection cavity of the injection cylinder, and the release port IB1 and the oil outlet IB are both connected to the release cavity of the injection cylinder; the filter is connected between the main oil outlet IFP and the oil pump inlet P, the safety valve is connected between the oil pump inlet P and the cooling port CT, two of the working ports of the material storage solenoid valve are correspondingly connected to the oil return port IF1 and the oil motor inlet SP, and the other two working ports of the material storage solenoid valve are correspondingly connected to the oil pump inlet P and one end of the proportional back pressure valve, the other end of the proportional back pressure valve is connected to the main oil return port IFT and the cooling port CT, one end of the one-way valve is connected to one end of the relief valve and then connected to the oil tank inlet T, the other end of the relief valve is connected to one end of the throttling one-way valve and then connected to the oil motor return port ST, and the other end of the throttling one-way valve is connected to the other end of the one-way valve and then connected to the release port IB1.

2. The micro injection oil circuit structure for an injection molding machine according to claim 1, characterized in that: The material storage solenoid valve adopts a two-position two-way valve; the proportional flow direction valve adopts a three-position four-way valve; the oil pump inlet P is connected to the oil pump, and the oil pump is connected to the hydraulic servo motor.

3. The micro injection oil circuit structure for an injection molding machine according to claim 2, characterized in that: An oil circuit block is installed on the outside of the shooting cylinder, the proportional flow directional valve is installed on the oil circuit block, two oil passages are arranged in the oil circuit block, two working ports of the proportional flow directional valve are correspondingly connected to the two oil passages, and the two oil passages are correspondingly connected to the shooting port and the release port of the shooting cylinder.

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