Special cylinder for flat type short-stroke push plate

Abstract

The utility model relates to a special cylinder for a flat short-stroke push plate, and belongs to the technical field of injection molding hot runners. Comprising a cylinder body, a top cover used for sealing and covering is arranged at the top of the cylinder body, a closed cavity is formed in the cylinder body, a reciprocating piston is arranged in the cavity, the bottom end of the piston extends downwards from the interior of the cylinder body, a fixedly-connected piston rod is arranged at the bottom of the piston, the cylinder body and the cavity are of a flat structure, and an annular edge protruding outwards is arranged at the top of the piston. The bottom of the plug rod is provided with a fixedly-connected push plate, and the bottom of the push plate is provided with a plurality of fixedly-connected needle valves. According to the scheme, the piston and the inner cavity are arranged to be of a flat structure, the longitudinal height of the cavity is reduced, the horizontal width of the cavity is increased, the longitudinal height is reduced, so that the stroke of the piston is shortened, when air enters the cavity, the piston moves slowly, control over the push plate and the needle valve is finer and more stable, and the precision of injection products is improved.

Description

Technical Field

[0001] This utility model belongs to the field of injection molding hot runner technology and relates to a special cylinder for a flat short-stroke push plate. Background Technology

[0002] Injection molds are devices used to produce plastic products. In some injection mold structures used to produce precision plastic parts, a hot runner structure is usually set inside the mold. Molten plastic, heated to a molten state, is heated and diverted by the hot runner system and then injected into the molding cavity of the mold through a hot nozzle connected to the bottom. The hot runner allows the plastic delivered to the gate by the injection machine's hot nozzle to always remain in a molten state, so it does not need to be solidified and removed as waste material each time the mold is opened. The molten material remaining in the gating system can be injected into the cavity again during the next injection.

[0003] To improve injection molding precision, a needle valve structure is installed inside the hot runner. When the needle valve moves upward, the inlet at the bottom of the hot runner is opened, allowing molten plastic to flow into the molding cavity. When the needle valve moves downward, it blocks the inlet, stopping the feeding into the molding cavity.

[0004] To control the movement of needle valves, existing technologies typically use a single cylinder to control the movement of a single needle valve. However, when the mold structure requires multiple hot nozzles to simultaneously feed material into the molding cavity, there is insufficient space inside the mold to accommodate the cylinder. Therefore, all the needle valves can be connected to a push plate at the top, and the movement of the push plate is controlled by the cylinder, thereby moving all the needle valves and controlling the feeding. However, the cylinder structure in existing technologies still has some shortcomings. The piston stroke inside the cylinder is relatively long, making it impossible to precisely control the distance the push plate moves. This prevents the needle valves from accurately sealing the bottom of the hot nozzles, thus affecting the amount of molten plastic injected into the molding cavity and impacting the precision of the molded product. Summary of the Invention

[0005] The purpose of this utility model is to address the problems existing in the current technology by proposing a flat, short-stroke push plate cylinder. The technical problem to be solved by this utility model is: how to improve the accuracy of the cylinder in controlling the up and down movement of the push plate.

[0006] The objective of this utility model can be achieved through the following technical solution: A flat, short-stroke push plate cylinder includes a cylinder body, a top cover for sealing, a sealed chamber inside the cylinder body, a reciprocating piston inside the chamber, the bottom end of the piston extending downward from inside the cylinder body, a fixed piston rod at the bottom of the piston, the cylinder body and the chamber having a flat structure, an outwardly protruding annular edge at the top of the piston dividing the chamber into upper and lower sides, a fixed push plate at the bottom of the piston rod, and several fixed needle valves at the bottom of the push plate.

[0007] In this design, the ring divides the cavity into upper and lower sections. When gas is injected into the upper cavity, the piston moves downward under pressure, and the piston rod pushes the push plate down, sealing the bottom of the hot runner nozzle with all needle valves and stopping the feeding of material into the molding cavity. Conversely, when gas is injected into the lower cavity, the piston, push plate, and needle valves move upward simultaneously, allowing the molten plastic inside the hot runner to be injected into the molding cavity. Since the needle valves do not need to move a long distance inside the hot runner nozzle to control the feeding, the piston and internal cavity are designed with a flat structure, reducing the vertical height of the cavity and increasing its horizontal width, keeping the cavity volume constant. Therefore, the piston can provide sufficient pushing and pulling force. The reduced vertical height shortens the piston stroke, slowing down the piston movement when gas is injected into the cavity, but also allowing for more precise and stable control of the push plate and needle valves, thus improving the accuracy of the injection molded products.

[0008] In the aforementioned flat, short-stroke pusher cylinder, a first air passage and a second air passage are connected to each other on the side wall of the cylinder body. The first air passage is connected to the top of the chamber, and the second air passage is connected to the bottom of the chamber. The first and second air passages are used to inject gas into the chamber, creating pressure above or below the chamber, thereby pushing the piston up and down.

[0009] In the aforementioned flat, short-stroke pusher cylinder, the sidewall of the ring edge is recessed inward, and a fixed Glyd ring is provided inside the recess of the ring edge. The outer side of the Glyd ring contacts the inner wall of the cylinder. The Glyd ring is used to separate the upper and lower sides of the chamber, allowing the piston to move under air pressure.

[0010] In the aforementioned flat, short-stroke pusher cylinder, a sealing ring is fixedly installed on the inner wall of the cylinder bottom, and the sealing ring is located at the part that contacts the bottom end of the piston. The sealing ring is used to seal the part where the bottom of the piston connects to the cylinder body.

[0011] In the aforementioned flat, short-stroke pusher cylinder, the bottom of the top cover is fixedly connected to the cylinder body, the top of the top cover protrudes outward and is wider than the cylinder body, and bolts are provided at the four corners of the top cover. The top of the top cover is larger than the diameter of the cylinder body, and bolts are installed on the outwardly extending portion to fix the entire cylinder to the mold.

[0012] In the aforementioned flat, short-stroke pusher cylinder, a shock-absorbing strip is provided at the bottom of the outwardly protruding part of the top cover, and the same shock-absorbing strip is also provided on the side wall and bottom of the cylinder body. The multiple shock-absorbing strip structures reduce the stress on the cylinder and improve its service life.

[0013] Compared with the prior art, the present invention has the following advantages:

[0014] 1. In this design, the piston and internal chamber are designed as a flat structure, reducing the vertical height of the chamber and increasing the horizontal width of the chamber, so that the volume of the chamber remains unchanged. Therefore, the piston can provide sufficient pushing and pulling force. The reduction in vertical height makes the piston stroke shorter. When air is introduced into the chamber, the piston moves more slowly, but the control of the push plate and needle valve is more precise and stable, improving the precision of injection molded products. Attached Figure Description

[0015] Figure 1 This is a three-dimensional structural diagram of the present invention;

[0016] Figure 2 This is a frontal half-sectional view of the structure of this utility model;

[0017] Figure 3 This is a schematic diagram of the connection structure between the cylinder and the push plate of this utility model.

[0018] In the diagram, 1 is the cylinder body; 1a is the sealing ring; 2 is the top cover; 2a is the bolt; 3 is the piston; 3a is the ring edge; 3b is the Glyd ring; 4 is the piston rod; 5 is the chamber; 5a is the first air passage; 5b is the second air passage; 6 is the shock absorber strip; 7 is the push plate; and 8 is the needle valve. Detailed Implementation

[0019] The following are specific embodiments of the present invention, which are described in conjunction with the accompanying drawings. However, the present invention is not limited to these embodiments.

[0020] Example

[0021] like Figure 1 As shown, a flat short-stroke push plate special cylinder includes a cylinder body 1. The top of the cylinder body 1 is provided with a top cover 2, the top of the top cover 2 protrudes outward and is wider than the cylinder body 1. Bolts 2a are provided at the four corners of the top cover 2. A piston 3 is provided inside the cylinder body 1 and is slidably connected. The bottom end of the piston 3 extends downward from inside the cylinder body 1. A fixed piston rod 4 is provided at the bottom of the piston 3.

[0022] like Figure 2As shown, the cylinder body 1 has a chamber 5 inside. The cylinder body 1 and the chamber 5 have a flat structure. The piston 3 has an outwardly protruding ring edge 3a at the top. The outer side of the ring edge 3a extends into the interior of the cylinder body 1. The side wall of the ring edge 3a is recessed inward. A fixed glyph ring 3b is provided inside the recess of the ring edge 3a. The outer side of the glyph ring 3b contacts the inner wall of the cylinder body 1. The ring edge 3a divides the chamber 5 into upper and lower sides. The side wall of the cylinder body 1 has a first air passage 5a and a second air passage 5b connected to each other. The first air passage 5a is connected to the upper part of the chamber 5, and the second air passage 5b is connected to the lower part of the chamber 5. A fixed sealing ring 1a is provided on the inner wall of the bottom of the cylinder body 1. The sealing ring 1a is located at the part that contacts the bottom end of the piston 3. The bottom of the outwardly protruding part of the top cover 2, the side wall of the cylinder body 1, and the bottom of the cylinder body 1 are all provided with shock-absorbing strips 6.

[0023] like Figure 3 As shown, the cylinder body 1 is fixedly mounted on the mold, the first air passage 5a and the second air passage 5b are located inside the mold, the bottom of the plug rod 4 is provided with a fixed push plate 7, the push plate 7 is slidably located inside the mold, and the bottom of the push plate 7 is provided with several fixed needle valves 8.

[0024] The working principle of this solution is as follows: Figure 1-3 As shown, the cylinder is fixedly installed in the mold. When gas is injected into the first air passage 5a, the air pressure above the chamber 5 increases. The piston 3 is pushed down under the action of air pressure, and the plug rod 4 drives the push plate 7 to press down, so that all the needle valves 8 block the bottom of the hot nozzle. At the same time, the hot nozzle stops feeding material into the molding cavity. Conversely, when gas is injected into the second air passage 5b, when air enters the chamber 5 below the ring edge 3a, the piston 3, push plate 7 and needle valve 8 move up at the same time, and the plastic melt inside the hot runner can be injected into the molding cavity.

[0025] By designing the piston 3 and the internal chamber 5 into a flat structure, the longitudinal height of the chamber 5 is reduced and the horizontal width of the chamber 5 is increased, so that the volume of the chamber 5 remains unchanged. Therefore, the piston 3 can provide sufficient pushing and pulling force. The reduction in longitudinal height makes the stroke of the piston 3 shorter. When air is introduced into the chamber 5, the piston 3 moves more slowly, but the control of the push plate 7 and the needle valve 8 is also more precise and stable, improving the precision of the injection molded products.

[0026] The specific embodiments described herein are merely illustrative examples illustrating the spirit of this utility model. Those skilled in the art to which this utility model pertains may make various modifications or additions to the described specific embodiments or use similar methods to substitute them, without departing from the spirit of this utility model or exceeding the scope defined by the appended claims.

[0027] Although this document frequently uses terms such as 1. cylinder body; 1a. sealing ring; 2. top cover; 2a. bolt; 3. piston; 3a. ring edge; 3b. Glyd ring; 4. piston rod; 5. chamber; 5a. first air passage; 5b. second air passage; 6. shock absorber strip; 7. push plate; 8. needle valve, the possibility of using other terms is not excluded. The use of these terms is merely for the convenience of describing and explaining the essence of this utility model; interpreting them as any additional limitation would contradict the spirit of this utility model.

Claims

1. A flat, short-stroke pusher cylinder, comprising a cylinder body (1), a top cover (2) for sealing the cylinder body (1), a sealed chamber (5) inside the cylinder body (1), a reciprocating piston (3) inside the chamber (5), the bottom end of the piston (3) extending downward from inside the cylinder body (1), and a fixed piston rod (4) at the bottom of the piston (3), characterized in that, The cylinder (1) and the chamber (5) have a flat structure. The piston (3) has an outwardly protruding ring edge (3a) at the top. The ring edge (3a) divides the chamber (5) into upper and lower sides. The bottom of the piston rod (4) is provided with a push plate (7) that is fixedly connected. The bottom of the push plate (7) is provided with several needle valves (8) that are fixedly connected.

2. The flat, short-stroke pusher cylinder according to claim 1, characterized in that, The cylinder (1) has a first air passage (5a) and a second air passage (5b) connected to each other on its side wall. The first air passage (5a) is connected to the top of the chamber (5), and the second air passage (5b) is connected to the bottom of the chamber (5).

3. A flat, short-stroke pusher cylinder according to claim 2, characterized in that, The sidewall of the ring edge (3a) is recessed inward, and a fixed glyph (3b) is provided inside the recess of the ring edge (3a). The outer side of the glyph (3b) is in contact with the inner wall of the cylinder body (1).

4. A flat, short-stroke pusher cylinder according to claim 1, characterized in that, A sealing ring (1a) is fixedly provided on the inner wall of the bottom of the cylinder (1), and the sealing ring (1a) is located at the part that contacts the bottom end of the piston (3).

5. A flat, short-stroke pusher cylinder according to claim 1, characterized in that, The bottom of the top cover (2) is fixedly connected to the cylinder body (1), the top of the top cover (2) protrudes outward and is wider than the cylinder body (1), and bolts (2a) are provided at the four corners of the top cover (2).

6. A flat, short-stroke pusher cylinder according to claim 5, characterized in that, The bottom of the outward protruding part of the top cover (2) is provided with a shock-absorbing strip (6), and the side wall and bottom of the cylinder body (1) are also provided with the same shock-absorbing strip (6).

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