Vacuum valve with non-return function

Abstract

The utility model relates to a vacuum valve with a non-return function, which comprises a valve body, a valve seat and a valve cover, a vacuum valve inlet is arranged at the outer end of the valve seat, a vacuum valve outlet is arranged on one side of the valve body, a valve rod is arranged in the valve body, the valve rod is arranged between a non-return valve core and a piston, a return spring is arranged between the piston and the valve cover, one end of the valve rod is inserted into an inner hole of the non-return valve core, and the other end of the valve rod is inserted into an outer hole of the non-return valve core. A gap exists between an inner hole of the check valve element and the outer circle of the valve rod, and a check spring is arranged between the check valve element and the valve body. The non-return function is added, oil return is prevented, and pollution of lubricating oil to a customer vacuum system is avoided; after the non-return function is added, oil loss is avoided, and the fault of oil shortage of a main engine cannot be caused; the check valve core is simpler to mount and dismount, and the vacuum valve is more convenient and quicker to maintain in the subsequent whole machine; and no part (especially a non-return spring) falls into the machine head in the dismounting process.

Description

Technical Field

[0001] The utility model relates to a vacuum valve, in particular to a vacuum valve with a check function. Background Art

[0002] At present, screw vacuum pumps are mainly divided into oil-free screw vacuum pumps and oil-containing screw vacuum pumps. The inlet of oil-free screw vacuum pumps is usually only equipped with a check valve. The inlet of oil-containing screw vacuum pumps usually must be equipped with an intake control valve (hereinafter referred to as a vacuum valve). Existing vacuum valve patents include CN 210106115 U, CN 107208642 A, and CN 219119894 U. Most of the existing vacuum valves are normally closed intake valves, and their functions mainly include: opening function, control pressure holding function, and closing function. The reliability of the closing action will directly affect whether the oil-containing vacuum valve will reverse oil. If the solenoid valve of the control valve fails, the control piston is blocked, or the return spring fails, the control valve core will not perform the closing action in time. At this time, the pressure on the customer's vacuum system side is lower than the pressure on the vacuum valve inlet side, and the vacuum pump lubricating oil will flow into the customer's vacuum system. The lubricating oil will contaminate the customer's vacuum system. At the same time, due to the reduction of the vacuum pump lubricating oil, it will cause the vacuum valve to start difficult or high-temperature shutdown and other faults, which should be avoided as much as possible in actual use. Summary of the invention

[0003] The purpose of the utility model is to overcome the above disadvantages and provide a vacuum valve with a check function.

[0004] The purpose of the utility model is achieved through the following technical scheme: a vacuum valve with a check function, comprising a valve body, a valve seat and a valve cover, the outer end of the valve seat is a vacuum valve inlet, one side of the valve body is provided with a vacuum valve outlet, a valve stem is provided in the valve body, the valve stem is placed between the check valve core and the piston, a return spring is provided between the piston and the valve cover, one end of the valve stem is inserted into the inner hole of the check valve core, there is a gap between the inner hole of the check valve core and the outer circle of the valve stem, and a check spring is provided between the check valve core and the valve body.

[0005] A further improvement of the utility model is that the check spring is tightly matched with the inner hole of the valve stem through the large circle at the end.

[0006] A further improvement of the utility model is that the check spring is tightly matched with the outer circle of the inner hole boss of the check valve core through the end circle.

[0007] A further improvement of the utility model is that the check spring is tightly matched with the outer circle of the boss of the inner hole of the valve stem through a circle at the end.

[0008] Compared with the prior art, the utility model has the following advantages:

[0009] The utility model adds a check function to prevent oil from flowing back and avoid the contamination of lubricating oil in the customer's vacuum system.

[0010] After the utility model adds the check function, oil loss is avoided, and the lack-of-oil fault of the main engine will not be caused.

[0011] The installation and disassembly of the check valve core are more concise, and it is more convenient and fast to maintain the vacuum valve of the whole machine subsequently.

[0012] No parts (especially the check spring) will fall into the machine head during the disassembly process. Description of the Drawings

[0013] Figure 1 It is a schematic structural diagram of the open state or closed state of Embodiment 1 of the utility model;

[0014] Figure 2 is Figure 1 The enlarged structural view of part A in

[0015] Figure 3 It is a schematic structural diagram of the check state of the valve core of Embodiment 1 of the utility model;

[0016] Figure 4 is Figure 3 The enlarged structural view of part B in

[0017] Figure 5 It is a schematic structural diagram of the open state or closed state of Embodiment 2 of the utility model;

[0018] Figure 6 is Figure 5 The enlarged structural view of part C in

[0019] Figure 7 It is a schematic structural diagram of the open state or closed state of Embodiment 3 of the utility model;

[0020] Figure 8 is Figure 7 The enlarged structural view of part D in

[0021] Reference numerals in the figure: 1 - valve body, 2 - valve seat, 3 - valve cover, 4 - vacuum valve inlet, 5 - vacuum valve outlet, 6 - valve rod, 7 - check valve core, 8 - piston, 9 - return spring, 10 - check spring. Detailed Embodiment

[0022] To deepen the understanding of the utility model, the following will further elaborate on the utility model in combination with embodiments and drawings. This embodiment is only used to explain the utility model and does not constitute a limitation on the protection scope of the utility model.

[0023] The following shows a specific embodiment of a vacuum valve with a check valve function according to the present invention: It includes a valve body 1, a valve seat 2 and a valve cover 3. The outer end of the valve seat 2 is a vacuum valve inlet 4. One side of the valve body 1 is provided with a vacuum valve outlet 5. A valve rod 6 is arranged inside the valve body 1. The valve rod 1 is placed between a check valve core 7 and a piston 8. A return spring 9 is arranged between the piston 8 and the valve cover 3. One end of the valve rod 6 is inserted into the inner hole of the check valve core 7. There is a gap between the inner hole of the check valve core 7 and the outer circle of the valve rod 6. In order to prevent the check spring 10 from falling into the machine head during use, the check spring 10 is placed in the inner hole of the check valve core 7 and the inner hole of the valve rod 6. In order to prevent the check spring 10 from falling into the machine head during disassembly, there are three embodiments of the check spring 10:

[0024] Embodiment 1: The check spring 10 is tightly fitted with the inner hole of the valve rod 6 through the large end coil.

[0025] Embodiment 2: The check spring 10 is tightly fitted with the outer circle of the boss of the inner hole of the check valve core 7 through the end coil.

[0026] Embodiment 3: The check spring 10 is tightly fitted with the outer circle of the boss of the inner hole of the valve rod 6 through the end coil.

[0027] When the vacuum valve is normally opened and closed, there is no relative movement between the check valve core and the valve rod. When the vacuum valve unloads or stops, and the piston of the vacuum valve acts abnormally, the check valve core will be disengaged from the valve rod and sealed with the valve seat under the action of the check spring and the reverse flow air of the vacuum valve, preventing the lubricating oil of the vacuum pump from flowing into the customer's vacuum system.

[0028] The present invention ensures that the check valve function is added on the basis of the original function unchanged. The application field of the vacuum valve with the added check valve function is extended from the original oil-sealed vacuum pump to the oil-free screw vacuum pump.

[0029] The applicant further declares that the present invention uses the above embodiments to illustrate the implementation method and device structure of the present invention, but the present invention is not limited to the above embodiments, that is, it does not mean that the present invention must rely on the above methods and structures to be implemented. Those skilled in the art should understand that any improvement to the present invention, the equivalent replacement of the implementation method selected by the present invention, the addition of steps, and the selection of specific methods, etc., all fall within the protection scope and the disclosed scope of the present invention.

[0030] The present invention is not limited to the above embodiments. All ways that adopt a structure similar to that of the present invention and its methods to achieve the purpose of the present invention are within the protection scope of the present invention.

Claims

1. A vacuum valve with a check function, comprising a valve body (1), a valve seat (2) and a valve cover (3), wherein the outer end of the valve seat (2) is a vacuum valve inlet (4), and one side of the valve body (1) is provided with a vacuum valve outlet (5), characterized in that: A valve stem (6) is provided in the valve body (1). The valve stem (6) is disposed between the check valve core (7) and the piston (8). A return spring (9) is provided between the piston (8) and the valve cover (3). One end of the valve stem (6) is inserted into the inner hole of the check valve core (7). There is a gap between the inner hole of the check valve core (7) and the outer circle of the valve stem (6). A check spring (10) is provided between the check valve core (7) and the valve stem (6).

2. A vacuum valve with a check function according to claim 1, characterized in that: The check spring (10) is tightly fitted into the inner hole of the valve stem (6) through the large end ring.

3. The vacuum valve with a check function according to claim 1, characterized in that: The check spring (10) is tightly fitted with the outer circle of the inner hole boss of the check valve core (7) through the end circle.

4. The vacuum valve with a check function according to claim 1, characterized in that: The check spring (10) is tightly fitted with the outer circle of the inner hole boss of the valve stem (6) through the end circle.

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