A hydraulic control check valve

Abstract

The utility model relates to a kind of hydraulic control check valve, comprising: valve body, inlet and outlet being set on valve body, upper cover, it is equipped with control port;First piston, it is set in the valve body inner cavity formed between the upper cover and valve body;Valve stem, is connected with first piston;Second piston, it is set in the outer portion of valve stem, and valve body inner cavity is divided into upper chamber and lower chamber;Main piston, it is set in the lower part of valve body, and is connected with the lower end of valve stem;Reset spring, it is set below the main piston. Through the synergic cooperation of control port and reset spring, the working mode of hydraulic control valve can be switched freely.

Description

Technical Field

[0001] This utility model relates to the field of valve technology, specifically to a hydraulically controlled check valve. Background Technology

[0002] Hydraulic check valves are key control components in hydraulic systems, widely used in engineering machinery, metallurgical equipment, marine deck machinery, and other applications requiring the locking of actuators (such as hydraulic cylinders) or the unidirectional opening and closing of oil circuits. Their basic function is to allow hydraulic oil to flow freely in one direction while cutting it off in the opposite direction.

[0003] Traditional hydraulic check valves typically perform only a single function: automatically opening in one direction based on fluid pressure, or opening in the reverse direction by an external control circuit actuating the valve core. However, in practical applications, operating conditions are often more complex. For example, in some cases, the system needs the valve to function as a standard check valve to prevent backflow and maintain the actuator's position; in other cases, the valve needs to be bidirectional under control signals, allowing the actuator to retract freely or the system to unload. Existing valve technologies struggle to efficiently and reliably integrate these two operating modes into a single structure.

[0004] Furthermore, in many existing hydraulic check valves, the control piston and main valve core are typically located in the same oil chamber or connected via an internal oil passage. This leads to the mixing of the control medium (such as control oil) with the working medium in the main circuit. If the working medium is hydraulic oil and the control medium is compressed air, or if their pressure ratings or cleanliness levels differ, problems such as medium contamination, control failure, or component damage may occur, reducing the valve's reliability and applicability.

[0005] Therefore, those skilled in the art urgently need a new type of hydraulically controlled check valve that can not only integrate one-way shut-off and hydraulically controlled bidirectional conduction functions, but also effectively isolate the media in different chambers, thereby improving the valve's operational reliability, functional versatility, and adaptability to complex working conditions. Utility Model Content

[0006] The purpose of this invention is to provide a hydraulically controlled check valve to solve the problems mentioned in the background art.

[0007] To achieve the above objectives, this utility model provides the following technical solution: a hydraulically controlled check valve, comprising: The valve body, with its inlet and outlet located on it. The top cover has a control port; The first piston is disposed within the inner cavity of the valve body formed between the upper cover and the valve body; The valve stem is connected to the first piston; The second piston is fitted outside the valve stem, dividing the valve body cavity into an upper chamber and a lower chamber; The main piston is located at the lower part of the valve body and is connected to the lower end of the valve stem. A return spring is located below the main piston.

[0008] Optionally, a cover plate is installed on the upper cover, and a first O-ring is provided between the cover plate and the upper cover for sealing.

[0009] Optionally, the valve stem is connected to the main piston via a thread.

[0010] Optionally, a second O-ring is provided between the first piston and the upper cover.

[0011] Optionally, a rear cover is installed at the bottom of the valve body.

[0012] Optionally, a nut is installed on the valve stem, and a flat washer is provided below the nut.

[0013] Optionally, the second piston is fixed at the connection between the upper cover and the valve body by a lock nut.

[0014] Compared with the prior art, the beneficial effects of this utility model are: 1. The working mode of the hydraulic control valve can be freely switched through the coordinated operation of the control port and the return spring; 2. The design of the second piston and its sealing components clearly divides the valve body into upper and lower chambers, which can effectively prevent the media in different chambers from mixing and interfering with each other, thereby improving the valve's operational reliability and adaptability to complex media environments. Attached Figure Description

[0015] Figure 1 This is a schematic diagram of the structure of this utility model. Detailed Implementation

[0016] To further illustrate the technical means and effects adopted by this utility model in order to achieve the intended utility model purpose, the following detailed description of the specific implementation methods, structure, features and effects of this utility model is provided in conjunction with the accompanying drawings and preferred embodiments.

[0017] like Figure 1 As shown, a hydraulically controlled check valve includes a valve body 1, an inlet P1 and an outlet P2 disposed on the valve body; an upper cover 2 having a control port K; a first piston 3 disposed within the valve body cavity formed between the upper cover 2 and the valve body 1; a valve stem 4 connected to the first piston 3; a second piston 5 sleeved outside the valve stem 4, dividing the valve body cavity into an upper cavity and a lower cavity; a main piston 8 disposed at the lower part of the valve body 1 and connected to the lower end of the valve stem 4; and a return spring 10 disposed below the main piston.

[0018] The upper cover 2 can be fitted with a cover plate 6, and a first O-ring 7 is provided between the cover plate 6 and the upper cover 2 for sealing. The valve stem 4 is threadedly connected to the main piston 8. A second O-ring 9 is provided between the first piston 3 and the upper cover 2 for effective sealing. A rear cover 11 is also installed at the bottom of the valve body 1. A nut 12 is installed on the valve stem 4, and a flat washer 14 is provided below the nut 12. The second piston 5 is fixed at the connection between the upper cover 2 and the valve body 1 by a lock nut 13.

[0019] This utility model has two working states: The first type is the two-way flow mode, in which the following operations are performed: (1) Introduce pressurized oil or compressed air through control port K (size 1 / 4 NPT); (2) The pressure medium enters the upper chamber and acts on the end face of the first piston 3, generating a downward thrust; (3) The first piston 3 moves downward, pushing the valve rod 4 connected to it to move downward together; (5) The lower end of the valve stem 4 overcomes the preload of the return spring 10 and forces the main piston 8 to open the main channel.

[0020] At this time, the main valve port is fully open, and the fluid can flow freely from the inlet P1 to the outlet P2, or flow back from the outlet P2 to the inlet P1, achieving bidirectional direct flow.

[0021] Throughout the process, the second piston 5 ensures that the control medium acting on the small first piston 3 is completely isolated from the main circuit medium in the lower chamber of the valve body, and that they do not interfere with each other.

[0022] The second type is the unidirectional flow mode, in which the following operations are performed: (1) Control port K is depressurized or always kept in a pressure-free state; (2) The preload of the return spring 10 becomes the dominant force. The spring extends, pushing the main piston 8 and the valve stem 4 connected to it to move upward together until the main piston 8 presses tightly against the valve body, closing the main channel.

[0023] At this time, if the pressure at inlet P1 increases due to fluid movement, the fluid pressure will act on the lower part of the main valve core piston 8. When this pressure is sufficient to overcome the preload and friction of the return spring 10, it will "push open" the main piston 8, causing the valve to open and the fluid to flow to the outlet (P2). At this time, the valve acts like a normal check valve.

[0024] The above description is merely a preferred embodiment of the present utility model and is not intended to limit the present utility model in any way. Although the present utility model has been disclosed above with reference to a preferred embodiment, it is not intended to limit the present utility model. Any person skilled in the art can make some modifications or alterations to the above-disclosed technical content to create equivalent embodiments without departing from the scope of the present utility model. Any simple modifications, equivalent changes and alterations made to the above embodiments based on the technical essence of the present utility model without departing from the scope of the present utility model shall still fall within the scope of the present utility model.

Claims

1. A hydraulically controlled check valve, comprising a valve body (1), an inlet (P1) and an outlet (P2) disposed on the valve body, characterized in that, Also includes: The top cover (2) has a control port (K); The first piston (3) is disposed inside the valve body cavity formed between the upper cover (2) and the valve body (1); The valve stem (4) is connected to the first piston (3); The second piston (5) is sleeved outside the valve stem (4) and divides the valve body cavity into an upper cavity and a lower cavity; The main piston (8) is located at the lower part of the valve body (1) and is connected to the lower end of the valve stem (4); A return spring (10) is located below the main piston.

2. The hydraulically controlled check valve according to claim 1, characterized in that, A cover plate (6) is installed on the upper cover (2), and a first O-ring (7) is provided between the cover plate (6) and the upper cover (2) for sealing.

3. A hydraulically controlled check valve according to claim 1, characterized in that, The valve stem (4) is connected to the main piston (8) by a thread.

4. A hydraulically controlled check valve according to claim 1, characterized in that, A second O-ring (9) is provided between the first piston (3) and the upper cover (2).

5. A hydraulically controlled check valve according to claim 1, characterized in that, The bottom of the valve body (1) is fitted with a rear cover (11).

6. A hydraulically controlled check valve according to claim 1, characterized in that, A nut (12) is installed on the valve stem (4), and a flat washer (14) is provided below the nut (12).

7. A hydraulically controlled check valve according to claim 1, characterized in that, The second piston (5) is fixed at the connection between the upper cover (2) and the valve body (1) by a lock nut (13).

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