Special mold moving valve plate for injection molding machine

Abstract

The utility model discloses a special mold moving valve plate for an injection molding machine, relates to the technical field of injection molding machines, and aims to solve the problems of low production efficiency of products caused by low mold closing speed and long mold closing period of the injection molding machine in the prior art. The valve block is an integrated valve block manufactured by integrally forming high-strength alloy cast iron or forged aluminum alloy; wherein the valve plate main body comprises three valve plate base surfaces which are perpendicular to one another or are distributed at a set angle, and standardized threaded holes, positioning pin holes and sealing ring grooves are respectively formed in the three valve plate base surfaces and are used for integrally mounting an electromagnetic reversing valve, a proportional valve and a pressure detection element; the mold opening action is started rapidly, the whole process is rapid, the overall speed of the idle stroke of the mold moving action is optimized, the whole forming period can be shortened, the mold closing and opening time of the injection molding machine is shortened, and therefore the production cycle efficiency of the whole machine is directly improved.

Description

Technical Field

[0001] This utility model relates to the field of injection molding machine technology, specifically to a special mold transfer valve plate for injection molding machines. Background Technology

[0002] Injection molding machines, also known as injection molding machines or injection molding machines, are the main molding equipment used to produce various shapes of plastic products from thermoplastic or thermosetting plastics using plastic molds. They are classified as vertical, horizontal, and all-electric. Injection molding machines heat the plastic, apply high pressure to the molten plastic, and inject it to fill the mold cavity.

[0003] The valve plate is a key component of the hydraulic system of an injection molding machine. It primarily controls the flow direction, pressure, and volume of hydraulic oil, thereby driving various actuators within the machine (such as mold closing, injection, and ejection). It is typically integrated from components like valve blocks, solenoid valves, and proportional valves, distributing and regulating hydraulic energy. The design and performance of the valve plate directly affect the injection molding machine's response speed, precision, and stability. However, the performance of current injection molding machine valve plates is limited by the performance of the hydraulic pump. When adjusting the direction of hydraulic oil delivery, kinetic energy is lost within the valve plate, resulting in low mold closing speed, long mold closing cycles, and ultimately, low production efficiency. Utility Model Content

[0004] The purpose of this utility model is to provide a special mold transfer valve plate for injection molding machines to solve the problems mentioned in the background art, such as low mold closing speed and long mold closing cycle of injection molding machines, which lead to low production efficiency of products.

[0005] To achieve the above objectives, this utility model provides the following technical solution: a mold transfer valve plate specifically for injection molding machines, comprising:

[0006] The valve plate body is an integrated valve block manufactured in one piece using high-strength alloy cast iron or forged aluminum alloy.

[0007] The valve plate body includes three valve plate base surfaces that are perpendicular to each other or distributed at a set angle. The three valve plate base surfaces are respectively provided with standardized threaded holes, positioning pin holes and sealing ring grooves for the integrated installation of electromagnetic directional valves, proportional valves and pressure detection elements.

[0008] The valve plate body has two sets of independent and symmetrically distributed hydraulic channels inside. One set of hydraulic channels includes a first inlet and a first outlet, and the other set includes a second inlet and a second outlet. A first valve core channel connects the first inlet and the first outlet. One end of the first valve core channel has a first mounting valve hole conforming to ISO4401 standard for installing a mold closing proportioning valve. A second valve core channel connects the second inlet and the second outlet. One end of the second valve core channel has a... The second mounting valve hole, which also conforms to the ISO4401 standard, is used to install the mold opening proportional valve. The valve plate body also integrates a first differential oil circuit and a second differential oil circuit. The first differential oil circuit is connected to the first valve core channel to realize differential circulation of hydraulic oil during the mold closing stage. The second differential oil circuit is connected to the second valve core channel to assist oil circulation during the mold opening stage. The valve plate body also integrates a mold opening quick valve mounting hole, a first detection hole, a second detection hole, and a third detection hole to form a multi-point pressure monitoring network.

[0009] In a preferred embodiment, the present invention can be further configured such that: the first differential oil circuit has two branches, wherein the first branch is used to guide the oil return from the rod chamber of the mold closing cylinder to the oil inlet side of the rodless chamber during the differential mold closing stage, and the second branch is connected to a channel, one end of which is provided with a discharge port.

[0010] In a preferred embodiment, the present invention can be further configured such that: a quick-opening valve mounting hole is provided above the channel, the quick-opening valve mounting hole is used to install a pressure relief valve, and the discharge port is connected to an external discharge pipeline.

[0011] In a preferred embodiment, the present invention can be further configured such that one end of the second differential oil circuit is connected to a pressure relief channel.

[0012] In a preferred embodiment, the present invention can be further configured such that: the first detection hole is disposed above the valve plate body, and the connection between the first mounting valve hole and the first valve core channel is connected to the first detection hole.

[0013] In a preferred embodiment, the present invention can be further configured such that: the second detection hole is located above the valve plate body, and the second detection hole is connected to the hydraulic flow channels where the first liquid inlet and the first liquid outlet are located through independent pressure-sensing pipes.

[0014] In a preferred embodiment, the present invention can be further configured such that the third detection hole is located above the valve plate body and is connected to the second differential oil circuit.

[0015] In a preferred embodiment, the present invention can be further configured such that: the valve plate base surface is used to fix and install the electromagnetic directional valve, and the outer surface of the valve plate body is subjected to anodizing or phosphating treatment.

[0016] Compared with the prior art, the beneficial effects of this utility model are:

[0017] This invention utilizes a built-in first and second differential oil circuit to achieve differential circulation of hydraulic oil during the mold closing and opening stages. In the initial mold closing phase, the differential connection replenishes the rodless chamber of the mold closing cylinder with the return oil, enabling the hydraulic pump's unit flow rate to drive a greater piston movement speed. This increases the mold closing idle stroke speed without increasing pump displacement or power consumption. During the mold opening stage, the mold opening quick valve mounting hole and its matching pressure relief valve achieve millisecond-level high-pressure release, instantly eliminating mold-locking resistance. Combined with the mold opening proportional valve and possible differential connections, this ensures rapid start-up and fast operation throughout the mold opening process. This comprehensive speed optimization for the idle stroke of the mold moving action shortens the entire molding cycle, reducing the mold closing and opening time of the injection molding machine, thereby directly improving the overall production cycle efficiency.

[0018] This utility model, through precise oil circuit design and comprehensive monitoring configuration, ensures smooth and accurate operation and long-term system reliability. Independently designed mounting holes for the mold closing and opening proportional valves completely decouple the control of the two core actions, allowing for independent stepless speed regulation and pressure control. This not only enables more complex fast-slow-fast switching during mold closing but also provides precise low-pressure mold protection, effectively preventing mold impact damage and improving mold life and product quality. The first, second, and third detection holes integrated on the valve plate form a multi-point pressure monitoring network, providing real-time feedback on mold closing pressure, oil circuit differential pressure, and differential loop status, thus ensuring precise control. The system achieves true closed-loop control, adjusting valve opening in a timely manner to compensate for load changes, ensuring consistent pressure and speed with each mold closing, greatly improving the stability of product molding quality. The highly integrated block structure embeds all major valves and complex oil circuits within a solid valve plate body, completely replacing the cumbersome external pipes and joints required by traditional distributed valve groups. This not only saves installation space but also fundamentally reduces the most common leakage points in hydraulic systems, enhances anti-contamination capabilities, and reduces the risk of downtime due to pipeline vibration and loose joints, significantly extending the equipment's mean time between failures (MTBF) and making maintenance simpler and more intuitive. Attached Figure Description

[0019] Figure 1 This is a schematic diagram of a mold transfer valve plate for injection molding machines according to the present invention;

[0020] Figure 2This is a cross-sectional view of the first liquid inlet and the first liquid outlet of this utility model.

[0021] Figure 3 This is a cross-sectional view of the second liquid inlet and the second liquid outlet of this utility model.

[0022] In the diagram: 1. Valve plate body; 2. Valve plate base surface; 3. First liquid inlet; 4. First liquid outlet; 5. Second liquid inlet; 6. Second liquid outlet; 7. First valve mounting hole; 8. First detection hole; 9. Mold opening quick valve mounting hole; 10. Second detection hole; 11. Third detection hole; 12. Discharge port; 13. First differential oil circuit; 14. Second valve mounting hole; 15. Second differential oil circuit. Detailed Implementation

[0023] The technical solutions of the present utility model will be clearly and completely described below with reference to the accompanying drawings of the embodiments of the present utility model. Obviously, the described embodiments are only some embodiments of the present utility model, and not all embodiments.

[0024] In the description of this application, it should be noted that the terms "upper," "lower," "inner," "outer," "top / bottom," etc., indicating the orientation or positional relationship are based on the orientation or positional relationship shown in the accompanying drawings, and are only for the convenience of describing this application and simplifying the description, and do not indicate or imply that the device or element referred to must have a specific orientation, or be constructed and operated in a specific orientation, and therefore should not be construed as a limitation of this application. Furthermore, the terms "first" and "second" are used for descriptive purposes only and should not be construed as indicating or implying relative importance.

[0025] In the description of this application, it should be noted that, unless otherwise expressly specified and limited, the terms "installed," "equipped with," "sleeved / connected," "connected," etc., should be interpreted broadly. For example, "connection" can be a fixed connection, a detachable connection, or an integral connection; it can be a mechanical connection or an electrical connection; it can be a direct connection or an indirect connection through an intermediate medium; it can be a connection within two components. Those skilled in the art can understand the specific meaning of the above terms in this application based on the specific circumstances.

[0026] Please see Figure 1-3 One embodiment of this utility model is a mold transfer valve plate for injection molding machines, comprising:

[0027] The valve plate body 1 is manufactured in one piece using high-strength alloy cast iron or forged aluminum alloy through precision CNC machining. Its internal oil passages are processed by deep hole drilling and electrochemical polishing, ensuring the smoothness and dimensional accuracy of the inner wall of the hydraulic flow channel. This effectively reduces the pressure loss and turbulence along the flow path of the hydraulic oil. The outer surface of the valve plate body 1 is anodized or phosphated to improve its corrosion resistance and wear resistance, and extend its service life. This not only ensures the structural strength and sealing reliability of the valve plate, but also improves the response speed and transmission efficiency of the hydraulic system due to the smooth internal hydraulic flow channel and low resistance. This reduces energy loss from the source and helps to shorten the mold closing cycle.

[0028] Please see Figure 1 The valve plate body 1 includes three valve plate base surfaces 2 that are perpendicular to each other or distributed at a specific angle. These three base surfaces constitute the main mounting plane of the valve plate. Multiple mounting holes are pre-set on the valve plate base surfaces 2 for fixing and installing several electromagnetic directional valves, including a first electromagnetic directional valve that controls the opening and closing of the first differential oil circuit 13, a second electromagnetic directional valve that controls the opening and closing of the mold opening oil circuit, and a third electromagnetic directional valve that controls the opening and closing of the second differential oil circuit 15. These electromagnetic directional valves are connected to the first liquid inlet 3, the first liquid outlet 4, the first differential oil circuit 13, the discharge port 12, the second liquid inlet 5, the second liquid outlet 6, and the second differential oil circuit 15 through pre-machined oil passages inside the valve plate, so as to realize the logic control and state switching of the oil circuit.

[0029] Please see Figure 1 , Figure 2 and Figure 3 The valve plate body 1 has two completely independent and non-interfering hydraulic flow channel systems: a first hydraulic flow channel system and a second hydraulic flow channel system. These systems are dedicated to controlling the mold closing and opening actions, respectively. The first hydraulic flow channel system includes a first inlet 3, a first outlet 4, and a first valve core channel connecting the two. The first inlet 3 is directly connected to the output end of the hydraulic pump via a high-pressure hose or steel pipe to receive high-pressure oil. The first outlet 4 is connected to the rodless chamber of the mold closing cylinder. A first mounting valve hole 7 is machined at one end of the first valve core channel. This valve hole is a cartridge valve hole conforming to the ISO4401 international standard and is used for mounting... A two-way proportional pressure reducing valve or proportional flow valve serves as the mold closing proportional valve. This valve is integrated inside the valve plate and receives electrical signals (usually 0-10V or 4-20mA) from the injection molding machine controller. It steplessly adjusts the oil pressure and flow through its valve port, thereby achieving precise and smooth control of the mold closing speed. The independent dedicated hydraulic flow channel for mold closing, combined with the high-performance proportional valve, realizes precise closed-loop control of the mold closing process. It can not only achieve high-speed mold closing, but also perform precise speed switching and low-pressure mold protection before mold contact, effectively preventing mold impact damage and improving control accuracy and process adaptability.

[0030] Please see Figure 1 and Figure 3 The second hydraulic flow channel system is symmetrical in structure and independent in function from the first hydraulic flow channel system. It includes a second inlet 5, a second outlet 6, and a second valve core channel connecting the two. The second outlet 6 is connected to the mold opening cylinder (usually the rod chamber of the mold closing cylinder). A second mounting valve hole 14 is provided at one end of the second valve core channel, which is also used to install a mold opening proportional valve. This proportional valve independently controls the oil supply during the mold opening process, realizing the adjustable and optimized mold opening speed. The independent mold opening hydraulic flow channel design makes the control of the mold opening action unaffected by the state of the mold closing oil circuit, and the response is more direct and rapid. With the proportional control, a smooth slow mold opening start and a fast idle mold opening can be achieved, further optimizing the entire mold opening cycle.

[0031] Please see Figure 2 To achieve rapid advancement during the initial mold closing stage, the valve plate body 1 is equipped with a first differential oil circuit 13 connected in parallel with the first valve core duct. This oil circuit has two branches: the first branch guides the return oil from the rod chamber of the mold closing cylinder to the inlet side of the rodless chamber during the differential mold closing stage; the second branch connects to the discharge port 12 to drain residual oil to the oil tank when the differential connection is disconnected, avoiding back pressure interference. During the rapid mold closing stage, under the control of the electromagnetic reversing valve, while the rodless chamber of the mold closing cylinder receives oil, the return oil from the rod chamber does not flow directly back to the oil tank, but is supplemented to the inlet of the rodless chamber through the first differential oil circuit 13, forming a "differential connection." This allows the pump flow to simultaneously supply both chambers of the cylinder. While reducing the effective thrust, it significantly increases the extension speed of the piston rod. One side of the first differential oil circuit 13 has an internal channel, one end of which leads to the discharge port 12 located on the side of the valve plate. When the mold closing transitions to the high-pressure mold locking stage, the differential connection is disconnected. Any low-pressure oil that may remain in the first differential oil circuit 13 can be led back to the oil tank through the external leakage pipeline via this discharge port 12 to prevent back pressure interference. The setting of the first differential oil circuit 13 is the key to improving the mold closing idle stroke speed. By utilizing the system's own oil circulation, the mold closing speed is improved without increasing the hydraulic pump flow. For large stroke molds, the cycle time is significantly shortened. The independent discharge port 12 ensures clean and efficient switching of the oil circuit state.

[0032] Please see Figure 1Above the channel, on the top surface of the valve plate, is a quick-opening valve mounting hole 9. This mounting hole is used to install a normally closed two-position two-way solenoid ball valve as a pressure relief valve. At the moment the mold opening action command is issued, the solenoid ball valve is energized and opens first, instantly connecting the high-pressure oil circuit of the rodless chamber of the mold closing cylinder (i.e., the connection end of the first outlet 4) to the oil tank or low-pressure circuit through the internal hydraulic flow channel, realizing rapid pressure relief. This pressure relief process is almost synchronous with the oil supply of the mold opening oil circuit, which greatly eliminates the static friction resistance and mold locking oil pressure resistance that need to be overcome at the initial stage of mold opening. The discharge port 12 also serves as an important low-pressure oil discharge channel during pressure relief, connecting to the external discharge pipeline. The quick-opening valve mounting hole 9 and the matching pressure relief valve constitute the "unlocking" mechanism for rapid mold opening. Its millisecond-level response speed ensures the instantaneous start of the mold opening action, solving the bottleneck problem of slow mold opening start in traditional systems and making a significant contribution to shortening the mold opening time.

[0033] Please see Figure 3 For the mold opening process, a second differential oil circuit 15 is connected in parallel between the second outlet 6 and the second valve core channel in the second hydraulic flow system. The function of this oil circuit is similar to that of the first differential oil circuit 13, but the timing of its action is different. During the mold opening process, through specific valve control logic, a portion of the oil discharged from the mold opening cylinder (rod chamber) can be guided through the second differential oil circuit 15 to the rodless chamber of the mold opening cylinder (i.e., the rod chamber of the mold closing cylinder) to assist the mold opening action and achieve differential rapid mold opening. One end of the second differential oil circuit 15 is also connected to a pressure relief channel to release the pressure in the differential circuit when necessary. The second differential oil circuit 15 provides another speed optimization method for the mold opening action. By recycling the oil internally, the speed potential of the hydraulic system is further explored, making the mold opening process more efficient and energy-saving.

[0034] Please see Figure 1 To ensure the safe and stable operation of the system and facilitate fault diagnosis, this utility model sets up multiple pressure detection points. The valve plate body 1 is provided with a first detection hole 8. This hole is directly connected to the connection between the first mounting valve hole 7 and the first valve core duct (i.e., the outlet pressure area of ​​the mold closing proportional valve) through a micro-drilling hole. A pressure sensor or pressure gauge can be installed on the first detection hole 8 to monitor the working pressure during the mold closing action in real time. The first detection hole 8 enables the operator or control system to directly obtain the most critical mold closing pressure signal, which is crucial for achieving accurate pressure closed-loop control, mold protection, and early warning of system faults (such as overload and leakage).

[0035] Please see Figure 1Furthermore, a second detection hole 10 is provided on the valve plate body 1. This detection hole is connected to the hydraulic flow channels where the first liquid inlet 3 and the first liquid outlet 4 are located through independent pressure-sensing pipes. The pressure difference (ΔP) between the oil inlet and outlet of the main oil circuit of the mold closing can be detected in real time through an external differential pressure sensor. This is used to monitor the hydraulic flow channel resistance and valve port status. By monitoring the pressure difference, the second detection hole 10 can indirectly assess the smoothness of the hydraulic flow channel, the degree of filter element blockage, or the wear status of the proportional valve port, providing an intuitive basis for preventive maintenance and helping to maintain the long-term efficient operation of the system.

[0036] Please see Figure 1 The valve plate body 1 is also provided with a third detection hole 11. This detection hole is connected to the second differential oil circuit 15 through the internal hydraulic flow channel. It is used to monitor the pressure status in the mold opening differential circuit in real time. The third detection hole 11 helps to monitor whether the mold opening differential action is executed normally and whether the pressure relief channel is effective, so as to ensure that the mold opening is fast and stable and avoid action jamming or impact caused by abnormal differential circuit pressure.

[0037] Please see Figure 1 In addition to installing proportional valves and quick valves, the valve plate base surface 2 has multiple preset standard mounting holes mainly used for fixing several solenoid directional valves. These solenoid directional valves are the core components for controlling the opening and closing of each oil circuit and the switching of directions. According to the instructions issued by the injection molding machine computer program, they precisely control the flow of hydraulic oil to the mold closing cylinder, mold opening cylinder, differential oil circuit and pressure relief oil circuit. By directly integrating the solenoid directional valves on the valve plate base surface 2, an integrated hydraulic control block is realized. All the main control logic is completed inside the valve plate. Only the actuator (cylinder) and power source (pump station) need to be connected externally. This greatly simplifies the system layout, improves the anti-pollution ability, and reduces the failure caused by external pipeline vibration and loose joints.

[0038] Working Principle: During operation, the hydraulic pump continuously supplies oil while the injection molding machine is running. When mold closing is required, the control system first energizes the solenoid valve controlling the first differential oil circuit 13 to establish a differential connection. Simultaneously, the mold closing proportional valve adjusts its opening according to the set speed curve. Pressurized oil enters from the first inlet 3. After adjustment by the proportional valve, most of the oil enters the rodless chamber of the mold closing cylinder through the first outlet 4 to push the mold closing. At the same time, the return oil from the rod chamber of the mold closing cylinder is introduced into the inlet side of the rodless chamber through the first differential oil circuit 13, realizing rapid differential mold closing (see relevant oil circuit structure). Figure 2At the end of mold closing, the differential connection is disconnected, and the system switches to high-pressure mold locking. At this time, the mold closing proportional valve mainly performs pressure control. The first detection hole 8 monitors the mold locking pressure in real time. When the mold locking pressure reaches the set value, the injection holding pressure stage begins. After the mold opening command is issued, the pressure relief valve installed on the mold opening quick valve mounting hole 9 opens instantly, quickly releasing the high pressure in the rodless chamber of the mold closing cylinder. At the same time, the solenoid reversing valve controlling the mold opening oil circuit is activated, and the mold opening proportional valve starts working. Pressurized oil enters from the second inlet 5, and after being regulated by the proportional valve, it enters the mold opening cylinder (the rod chamber of the mold closing cylinder) through the second outlet 6 (see relevant oil circuit structure). Figure 3 As needed, the solenoid valve of the second differential oil circuit 15 may be activated to realize mold opening differential and further accelerate the mold opening speed. During the mold opening process, each detection hole continuously provides pressure feedback to ensure smooth operation. After the mold opening is in place, all valves are reset and the system waits for the next cycle.

[0039] It will be apparent to those skilled in the art that this invention is not limited to the details of the exemplary embodiments described above, and that it can be implemented in other specific forms without departing from the spirit or essential characteristics of this invention. Therefore, the embodiments should be considered exemplary and non-limiting in all respects. The scope of this invention is defined by the appended claims rather than the foregoing description, and thus all variations falling within the meaning and scope of equivalents of the claims are intended to be included within this invention. No reference numerals in the claims should be construed as limiting the scope of the claims.

Claims

1. A dedicated transfer valve plate for an injection molding machine, characterized by: The utility model relates to a valve plate body (1) is integrated valve block made by integral forming with high-strength alloy cast iron or forged aluminum alloy, Wherein, the valve plate body (1) includes three mutually perpendicular or set angle distribution valve plate base surface (2), three valve plate base surface (2) are provided with the threaded hole, positioning pin hole and sealing ring groove respectively, for integrated installation electromagnetic reversing valve, proportional valve and pressure detection element, The inside of the valve plate body (1) is provided with two groups of independent and symmetrical distribution hydraulic flow channel, one group of hydraulic flow channel includes first liquid inlet (3) and first liquid outlet (4), another group of hydraulic flow channel includes second liquid inlet (5) and second liquid outlet (6), the first liquid inlet (3) and first liquid outlet (4) are communicated with first valve core channel, one end of first valve core channel is provided with first installation valve hole (7) meeting ISO4401 standard, is used for installing the proportional valve of closing mould, second liquid inlet (5) and second liquid outlet (6) are communicated with second valve core channel, one end of second valve core channel is provided with second installation valve hole (14) also meeting ISO4401 standard, is used for installing proportional valve of opening mould, the valve plate body (1) still is provided with first differential oil circuit (13) and second differential oil circuit (15) integrally, first differential oil circuit (13) is communicated with first valve core channel and is arranged, is used for realizing differential circulation of hydraulic oil in closing mould stage, second differential oil circuit (15) is communicated with second valve core channel and is arranged, is used for assisting oil circulation in opening mould stage, the valve plate body (1) still has opening mould quick valve installation hole (9), first detection hole (8), second detection hole (10) and third detection hole (11) and forms multi-point pressure monitoring network. The first differential oil circuit (13) is provided with two branches, wherein the first branch is used for guiding the rod cavity oil return of closing mould oil cylinder to the oil inlet side of rodless cavity in differential closing mould stage, the second branch is connected with a channel, one end of the channel is provided with a discharge port (12).

2. A transfer valve plate for an injection molding machine as defined in claim 1, wherein: The upper portion of the channel is provided with an opening mould quick valve installation hole (9), the opening mould quick valve installation hole (9) is used for installing pressure relief valve, the discharge port (12) is connected with an external discharge pipeline.

3. A dedicated transfer valve plate for injection molding machines according to claim 2, characterized in that: One end of the second differential oil circuit (15) is connected with a pressure relief channel.

4. The dedicated transfer valve plate for injection molding machines according to claim 1, characterized in that: The first detection hole (8) is arranged above the valve plate body (1), and the connection part of the first installation valve hole (7) and the first valve core channel is communicated with the first detection hole (8).

5. The dedicated transfer valve plate for injection molding machines as defined in claim 1, wherein: The second detection hole (10) is arranged above the valve plate body (1), and the second detection hole (10) is communicated with the hydraulic flow channel where the first liquid inlet (3) and the first liquid outlet (4) are arranged through an independent pressure lead pipeline.

6. A dedicated transfer valve plate for injection molding machines as defined in claim 1, characterized in that: The third detection hole (11) is arranged above the valve plate body (1), and the third detection hole (11) is communicated with the second differential oil circuit (15).

7. A dedicated transfer valve plate for injection molding machines as defined in claim 1, characterized in that: The valve plate base surface (2) is used for fixedly installing electromagnetic reversing valve, and the outer surface of the valve plate body (1) is subjected to anodizing or phosphating treatment.

8. A dedicated transfer valve plate for injection molding machines as defined in claim 1, characterized in that: ​

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