Vacuum pump positive and negative pressure switching unloading protection system

Abstract

The utility model relates to a positive and negative pressure switching unloading protection system for a vacuum pump, which is applied to a tank body of a suction-type sewer scavenger and comprises the vacuum pump and a four-way valve, the four-way valve is provided with a first connecting port communicated with the tank body, a second connecting port communicated with the air inlet end of the vacuum pump, a third connecting port communicated with the air outlet end of the vacuum pump and a fourth connecting port, and the four-way valve has a first state, a second state and a third state; when the sewage suction truck carries out sewage suction operation, the four-way valve is in a first state, the vacuum pump generates suction force to the tank body of the sewage suction truck, when the sewage suction truck needs to discharge sewage, the four-way valve is in a third state, the vacuum pump supplies air into the tank body of the sewage suction truck, and when the four-way valve is switched between the first state and the third state, the four-way valve is switched to the third state firstly, and the vacuum pump supplies air into the tank body of the sewage suction truck. The air inlet end and the air outlet end of the vacuum pump are communicated, switching is carried out until unloading of the vacuum pump is completed, and the internal pressure conversion process is gentle in the positive and negative pressure switching process of the vacuum pump.

Description

Technical Field

[0001] The utility model relates to the technical field of special vehicles, in particular to a positive and negative pressure switching unloading protection system for a vacuum pump. Background Art

[0002] At present, in order to facilitate the switching of the positive pressure in the vacuum air circuit for sewage suction trucks, a pneumatic actuator is generally used to switch the four-way valve on the vacuum pump to achieve negative pressure suction or positive pressure backflushing.

[0003] However, the existing pneumatic actuator only has a positive pressure position or a negative pressure position. When the vacuum pump switches between positive and negative pressures, the pump body of the vacuum pump will be damaged due to sudden pressure changes. Prolonged use will affect the service life of the vacuum pump and reduce the operation efficiency of the vehicle. Summary of the Utility Model

[0004] In view of this, it is necessary to provide a positive and negative pressure switching unloading protection system for a vacuum pump to solve the problem that the existing pneumatic actuator only has a positive pressure position or a negative pressure position. When the vacuum pump switches between positive and negative pressures, the pump body of the vacuum pump will be damaged due to sudden pressure changes. Prolonged use will affect the service life of the vacuum pump and reduce the operation efficiency of the vehicle.

[0005] The utility model provides a positive and negative pressure switching unloading protection system for a vacuum pump, which is applied to the tank body of a sewage suction truck and includes a vacuum pump and a four-way valve. The vacuum pump has an air inlet end and an air outlet end. The four-way valve has a first connection port communicated with the tank body, a second connection port communicated with the air inlet end of the vacuum pump, a third connection port communicated with the air outlet end of the vacuum pump, and a fourth connection port. The four-way valve has a first state, a second state, and a third state. When the four-way valve is in the first state, the first connection port is communicated with the second connection port, and the third connection port is communicated with the fourth connection port to suck the tank body. When the four-way valve is in the second state, the first connection port and the fourth connection port are closed, and the second connection port is communicated with the third connection port to unload the vacuum pump. When the four-way valve is in the third state, the first connection port is communicated with the third connection port, and the second connection port is communicated with the fourth connection port to send air into the tank body.

[0006] Further, the four-way valve includes a valve body and a valve core. The first connection port, the second connection port, the third connection port, and the fourth connection port are formed on the valve body. The valve core is movably connected to the valve body, and the valve body can move to a position where the four-way valve is in the first state, the second state, or the third state.

[0007] Further, the valve core is a baffle structure with a notch. When the valve core moves to the position where the four-way valve is in the first state, the notch of the valve core abuts against the protrusion on the valve body. The first connection port and the second connection port are located on one side of the valve core, and the third connection port and the fourth connection port are located on the other side of the valve core. When the valve core moves to the position where the four-way valve is in the second state, both sides of the valve core are connected through the notch thereon, and the valve core covers the first connection port and the fourth connection port. When the valve core moves to the position where the four-way valve is in the third state, the notch of the valve core abuts against the protrusion on the valve body. The first connection port and the third connection port are located on one side of the valve core, and the second connection port and the fourth connection port are located on the other side of the valve core.

[0008] Further, the valve body and the valve core are rotatably connected.

[0009] Further, the valve body and the valve core are slidably connected.

[0010] Further, an air outlet pipe and an air inlet pipe are further included. The air outlet pipe communicates with the third connection port and the air outlet end of the vacuum pump, and the air inlet pipe communicates with the second connection port and the air inlet end of the vacuum pump. A check valve is installed on the air inlet pipe to allow the air flow in the air inlet pipe to flow in the direction from the second connection port to the air inlet end of the vacuum pump.

[0011] Further, a first connecting pipe is further included. The first connecting pipe communicates with the tank body and the first connection port.

[0012] Further, a first check valve and a second check valve are installed on the first connecting pipe.

[0013] Further, a second connecting pipe is further included. The second connecting pipe communicates with the fourth connection port.

[0014] Further, a silencer is installed on the second connecting pipe.

[0015] Compared with the prior art, when the sewage suction truck performs sewage suction operation, the four-way valve is in the first state, and the vacuum pump generates a suction force on the sewage suction truck tank body. When the sewage suction truck needs to discharge sewage, the four-way valve is in the third state, and the vacuum pump sends air into the sewage suction truck tank body. When the four-way valve switches between the first state and the third state, first switch the four-way valve to the third state, and the air inlet and outlet ends of the vacuum pump are connected until the unloading of the vacuum pump is completed, and then perform the switching. During the positive and negative pressure switching process of the vacuum pump, the pressure change process therein is gentle, effectively avoiding damage to the pump body of the vacuum pump caused by sudden pressure changes. Description of the Drawings

[0016] Figure 1Schematic diagram of the overall operation when the four-way valve is in the first state in the positive and negative pressure switching unloading protection system of the vacuum pump provided by the embodiment of the present invention;

[0017] Figure 2 Schematic diagram of the overall operation when the four-way valve is in the second state in the positive and negative pressure switching unloading protection system of the vacuum pump provided by the embodiment of the present invention;

[0018] Figure 3 Schematic diagram of the overall operation when the four-way valve is in the third state in the positive and negative pressure switching unloading protection system of the vacuum pump provided by the embodiment of the present invention. Detailed implementation manners

[0019] The preferred embodiments of the present invention will be specifically described below with reference to the accompanying drawings. The accompanying drawings form a part of the present application and are used together with the embodiments of the present invention to explain the principle of the present invention, and are not used to limit the scope of the present invention.

[0020] As Figures 1-3 shown, a positive and negative pressure switching unloading protection system of a vacuum pump provided by the present application is applied to the tank body 100 of a sewage suction truck. When the tank body 100 is evacuated, a negative pressure is formed inside the tank body 100 to facilitate the sewage suction work of the sewage suction truck. At the same time, when the tank body 100 is supplied with gas, a positive pressure is formed inside the tank body 100 to facilitate the discharge of the sewage therein. It can be understood that the sewage suction truck has a sewage suction end 110 connected to the tank body 100. The sewage suction work can be realized through the sewage suction end 110. The sewage suction end 110 can be a sewage suction pipe or a sewage discharge port. A sewage suction valve 120 can be installed on the sewage suction pipe, and a safety valve 130 can be installed on the tank body 100. The form of the tank body is not limited.

[0021] A positive and negative pressure switching unloading protection system for a vacuum pump 200 provided by the utility model is applied to the tank body 100 of a sewage suction truck, and includes a vacuum pump 200 and a four-way valve 300. The vacuum pump 200 has an air inlet end and an air outlet end. The four-way valve 300 has a first connection port communicated with the tank body 100, a second connection port communicated with the air inlet end of the vacuum pump 200, a third connection port communicated with the air outlet end of the vacuum pump 200, and a fourth connection port. The four-way valve 300 has a first state, a second state and a third state. When the four-way valve 300 is in the first state, the first connection port is communicated with the second connection port, and the third connection port is communicated with the fourth connection port to suck the tank body 100. When the four-way valve 300 is in the second state, the first connection port and the fourth connection port are closed, and the second connection port is communicated with the third connection port to unload the vacuum pump 200. When the four-way valve 300 is in the third state, the first connection port is communicated with the third connection port, and the second connection port is communicated with the fourth connection port to send air into the tank body 100.

[0022] During implementation, when the sewage suction truck performs sewage suction operation, the four-way valve 300 is in the first state, and the vacuum pump 200 generates a suction force on the tank body 100 of the sewage suction truck. When the sewage suction truck needs to discharge sewage, the four-way valve 300 is in the third state, and the vacuum pump 200 sends air into the tank body 100 of the sewage suction truck. When the four-way valve 300 switches between the first state and the third state, first switch the four-way valve 300 to the third state, and the air inlet and outlet ends of the vacuum pump 200 are communicated. After the unloading of the vacuum pump 200 is completed, then switch. During the positive and negative pressure switching process of the vacuum pump 200, the internal pressure change process is gentle, effectively avoiding damage to the pump body of the vacuum pump 200 due to sudden pressure change.

[0023] The vacuum pump 200 in this implementation scheme has an air inlet end and an air outlet end.

[0024] The four-way valve 300 in this embodiment has a first connection port communicating with the tank body 100, a second connection port communicating with the intake end of the vacuum pump 200, a third connection port communicating with the outlet end of the vacuum pump 200, and a fourth connection port. The four-way valve 300 has a first state, a second state, and a third state. When the four-way valve 300 is in the first state, the first connection port is connected to the second connection port, and the third connection port is connected to the fourth connection port to suck the tank body 100. When the four-way valve 300 is in the second state, the first connection port and the fourth connection port are closed, and the second connection port is connected to the third connection port to unload the vacuum pump 200. When the four-way valve 300 is in the third state, the first connection port is connected to the third connection port, and the second connection port is connected to the fourth connection port to supply gas into the tank body 100.

[0025] In one embodiment, the four-way valve 300 includes a valve body and a valve core. The first connection port, the second connection port, the third connection port, and the fourth connection port are formed on the valve body. The valve core is movably connected to the valve body, and the valve body can move to a position where the four-way valve 300 is in the first state, the second state, or the third state.

[0026] Wherein, the valve core is a baffle structure with a notch. When the valve core moves to a position where the four-way valve 300 is in the first state, the notch of the valve core abuts against the protrusion on the valve body. The first connection port and the second connection port are located on one side of the valve core, and the third connection port and the fourth connection port are located on the other side of the valve core. When the valve core moves to a position where the four-way valve 300 is in the second state, both sides of the valve core are connected through the notch thereon, and the valve core covers the first connection port and the fourth connection port. When the valve core moves to a position where the four-way valve 300 is in the third state, the notch of the valve core abuts against the protrusion on the valve body. The first connection port and the third connection port are located on one side of the valve core, and the second connection port and the fourth connection port are located on the other side of the valve core.

[0027] It can be understood that other forms of structures can also be adopted for the valve body and the valve core to realize the switching of the four-way valve 300 between the first state, the second state, and the third state.

[0028] In one embodiment, the valve body and the valve core are rotatably connected. In another embodiment, the valve body and the valve core are slidably connected. It can be understood that the connection manner between the valve body and the valve core is not limited.

[0029] This embodiment further includes an air outlet pipe 210 and an air inlet pipe 220. The air outlet pipe 210 communicates with the third connection port and the air outlet end of the vacuum pump 200. The air inlet pipe 220 communicates with the second connection port and the air inlet end of the vacuum pump 200. A check valve 221 is installed on the air inlet pipe 220 to allow the air flow in the air inlet pipe 220 to flow in the direction from the second connection port to the air inlet end of the vacuum pump 200.

[0030] This embodiment further includes a first connecting pipe 310. The first connecting pipe 310 communicates with the tank body 100 and the first connection port.

[0031] This embodiment further includes a first check valve 311 and a second check valve 312 installed on the first connecting pipe 310.

[0032] This embodiment further includes a second connecting pipe 320. The second connecting pipe 320 communicates with the fourth connection port.

[0033] This embodiment further includes a silencer 321 installed on the second connecting pipe 320.

[0034] Compared with the prior art: When the sewage suction truck performs the sewage suction operation, the four-way valve 300 is in the first state, and the vacuum pump 200 generates a suction force on the tank body 100 of the sewage suction truck. When the sewage suction truck needs to discharge sewage, the four-way valve 300 is in the third state, and the vacuum pump 200 sends air into the tank body 100 of the sewage suction truck. When the four-way valve 300 switches between the first state and the third state, first switch the four-way valve 300 to the third state, and the air inlet and outlet ends of the vacuum pump 200 are connected until the unloading of the vacuum pump 200 is completed, and then switch. During the positive and negative pressure switching process of the vacuum pump 200, the pressure change process inside is gentle, effectively avoiding damage to the pump body of the vacuum pump 200 caused by sudden pressure changes.

[0035] The above is only a preferred specific embodiment of the present invention, but the protection scope of the present invention is not limited thereto. Any changes or substitutions that can be easily thought of by those skilled in the art within the technical scope disclosed by the present invention should be covered by the protection scope of the present invention.

Claims

1. A positive and negative pressure switching unloading protection system for a vacuum pump, characterized in that, A tank body applied to a sewage suction truck, comprising: A vacuum pump having an intake end and an outlet end; A four-way valve having a first connection port communicating with the tank body, a second connection port communicating with the intake end of the vacuum pump, a third connection port communicating with the outlet end of the vacuum pump, and a fourth connection port, and the four-way valve has a first state, a second state, and a third state; When the four-way valve is in the first state, the first connection port communicates with the second connection port, and the third connection port communicates with the fourth connection port for sucking the tank body; When the four-way valve is in the second state, the first connection port and the fourth connection port are closed, and the second connection port communicates with the third connection port for unloading the vacuum pump; When the four-way valve is in the third state, the first connection port communicates with the third connection port, and the second connection port communicates with the fourth connection port for supplying air into the tank body.

2. The positive and negative pressure switching unloading protection system for a vacuum pump according to claim 1, characterized in that, The four-way valve includes a valve body and a valve core. The first connection port, the second connection port, the third connection port, and the fourth connection port are formed on the valve body. The valve core is movably connected to the valve body, and the valve body can move to a position where the four-way valve is in the first state, the second state, or the third state.

3. The positive and negative pressure switching unloading protection system for a vacuum pump according to claim 2, wherein, The valve core is a baffle structure with a notch. When the valve core moves to the position where the four-way valve is in the first state, the notch of the valve core abuts against the protrusion on the valve body. The first connection port and the second connection port are located on one side of the valve core, and the third connection port and the fourth connection port are located on the other side of the valve core. When the valve core moves to the position where the four-way valve is in the second state, both sides of the valve core are connected through the notch thereon, and the valve core covers the first connection port and the fourth connection port. When the valve core moves to the position where the four-way valve is in the third state, the notch of the valve core abuts against the protrusion on the valve body. The first connection port and the third connection port are located on one side of the valve core, and the second connection port and the fourth connection port are located on the other side of the valve core.

4. The positive and negative pressure switching unloading protection system for a vacuum pump according to claim 2, wherein The valve body and the valve core are rotatably connected.

5. The positive and negative pressure switching unloading protection system for a vacuum pump according to claim 2, wherein The valve body and the valve core are slidably connected.

6. The positive and negative pressure switching unloading protection system for a vacuum pump according to claim 1, wherein It further includes an outlet pipe and an inlet pipe. The outlet pipe connects the third connection port and the outlet end of the vacuum pump, and the inlet pipe connects the second connection port and the intake end of the vacuum pump. A check valve is installed on the inlet pipe to allow the air flow in the inlet pipe to flow in the direction from the second connection port to the intake end of the vacuum pump.

7. The positive and negative pressure switching unloading protection system of the vacuum pump according to claim 1, characterized in that, It further includes a first connecting pipe connecting the tank body and the first connection port.

8. The positive and negative pressure switching unloading protection system for a vacuum pump according to claim 7, characterized in that, It further includes a first check valve and a second check valve installed on the first connecting pipe.

9. The positive and negative pressure switching unloading protection system for a vacuum pump according to claim 1, characterized in that, It further includes a second connecting pipe communicating with the fourth connection port.

10. The positive and negative pressure switching unloading protection system for a vacuum pump according to claim 9, characterized in that, It further includes a muffler installed on the second connecting pipe.

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