New urea pump assembly

Abstract

This invention relates to a novel urea pump assembly with a more rational structure and higher integration. This novel urea pump assembly includes a main pump and an auxiliary pump. The auxiliary pump has a flow-limiting check valve structure, which includes a valve cover, a check valve seat, and a check diaphragm. A chamber is formed between the valve cover and the check valve seat. The check diaphragm is located within the chamber and divides the chamber into an inlet chamber and an outlet chamber. The check diaphragm has an inlet membrane core and an outlet membrane core. The inlet membrane core is located within the inlet chamber, and the outlet membrane core is located within the outlet chamber. The valve cover has an inlet port and an outlet port, which communicate with the inlet chamber and the outlet port, respectively. This novel urea pump assembly significantly optimizes the assembly structure and simplifies the assembly process by integrating the overflow circuit and the return circuit, thereby controlling the overall assembly cost reduction.

Description

Technical Field

[0001] The invention relates to a device applied to a vehicle, in particular to a urea pump assembly. Background Art

[0002] As national emission requirements increase, more and more diesel vehicles need to be equipped with SCR systems to neutralize nitrogen oxides with urea to reduce the pollution of diesel vehicles to the environment. The core component of the SCR system is the urea pump assembly. Figure 8 As shown, the general urea pump assembly includes a housing, a main pump and an auxiliary pump. The main pump is used to pump the urea in the urea tank into the injector, and the injector then injects the urea into the exhaust pipe. Since the main pump is a diaphragm pump, it can only achieve unidirectional flow. In order to achieve reflux, to prevent the urea from freezing in the pipeline and the injector when not in use in a low-temperature environment, the urea in the pipeline and the injector needs to flow back to the urea tank when not working. Since the main pump is unidirectional and cannot be pumped back, an auxiliary pump must be configured. The auxiliary pump is also a diaphragm pump, which pumps the urea liquid in the pipeline and the injector back to the urea tank through a reflux pipeline (i.e. reflux); and in order to stabilize the system working pressure, the general urea pump needs to return part of the urea to the urea tank through the reflux pipeline after pumping out the urea (i.e. overflow), so that the system working pressure tends to be more stable. Therefore, the existing urea pump requires an overflow channel and a reflux channel. At present, the overflow and reflux of a general urea pump assembly are independent, which makes the structure of the urea pump assembly more complicated, the assembly more inconvenient, and the cost higher. Summary of the invention

[0003] In view of the deficiencies in the prior art, the present invention innovatively provides a new urea pump assembly with a more reasonable structure and higher integration.

[0004] The novel urea pump assembly includes a main pump and an auxiliary pump, the auxiliary pump has a flow-limiting check valve structure, the flow-limiting check valve structure includes a valve cover, a check valve seat and a check diaphragm, a chamber is formed between the valve cover and the check valve seat, the check diaphragm is located in the chamber and divides the chamber into a liquid inlet chamber and a liquid outlet chamber, the check diaphragm has a liquid inlet diaphragm core and a liquid outlet diaphragm core, the liquid inlet diaphragm core is located in the liquid inlet chamber, the liquid outlet diaphragm core is located in the liquid outlet chamber, the valve cover is provided with a liquid inlet and a liquid outlet, the liquid inlet is communicated with the liquid inlet chamber, the liquid outlet is communicated with the liquid outlet chamber, and the characteristic is that the ... valve seat, the check valve seat and the check valve seat form a chamber, the check valve seat and the check valve seat form a chamber, the check valve seat and the check valve seat form a chamber, the check valve seat The characteristics are: an overflow hole, a middle hole and a liquid outlet hole are provided on the check valve seat, the overflow hole and the middle hole are communicated with the liquid inlet chamber, the liquid outlet hole is communicated with the liquid outlet chamber, the liquid inlet membrane core covers the liquid inlet and is staggered with the overflow hole and the middle hole, the liquid outlet membrane core covers the liquid outlet and is staggered with the liquid outlet, the auxiliary pump has a power source and a membrane cover, the power source is transmission-connected with the membrane cover, a sealed pump chamber is formed between the membrane cover and the check valve seat, the overflow hole, the liquid outlet hole and the middle hole are communicated with the sealed pump chamber, and a sealing protrusion for blocking the middle hole is provided on the membrane cover.

[0005] The non-return diaphragm has a sealing ring portion and a sealing middle portion, the liquid inlet membrane core and the liquid outlet membrane core are located in the sealing ring portion, and the sealing middle portion separates the liquid inlet membrane core from the liquid outlet membrane core.

[0006] According to a novel urea pump assembly provided by the present invention, the overflow circuit and the return circuit are integrated together, thereby greatly optimizing the assembly structure and simplifying the assembly steps, thereby controlling the reduction of the cost of the entire assembly. BRIEF DESCRIPTION OF THE DRAWINGS

[0007] Figure 1 It is the pipeline diagram of the present invention;

[0008] Figure 2 The flow limiting check valve of the present invention explodes Figure 1 ;

[0009] Figure 3 The flow limiting check valve of the present invention explodes Figure 2 ;

[0010] Figure 4 A schematic diagram of the structure of the check valve seat 3;

[0011] Figure 5 A schematic diagram of the combination of the check valve seat 3 and the check diaphragm 2;

[0012] Figure 6 This is the overflow principle diagram;

[0013] Figure 7 This is the reflow schematic diagram;

[0014] Figure 8This is the piping diagram of the existing urea pump assembly. DETAILED DESCRIPTION

[0015] like Figure 1 As shown, this novel urea pump assembly includes a main pump 7 and an auxiliary pump 4, and the auxiliary pump 4 has a flow limiting check valve structure, such as Figure 2 As shown, the flow limiting check valve structure includes a valve cover 1, a check valve seat 3 and a check diaphragm 2 (made of rubber material). A chamber is formed between the valve cover 1 and the check valve seat 3. The check diaphragm 2 is located in the chamber and divides the chamber into a liquid inlet chamber 30 and a liquid outlet chamber 31. The check diaphragm 2 itself has a sealing effect. The check diaphragm 2 is located in the chamber and can divide it into a liquid inlet chamber 30 and a liquid outlet chamber 31 that are not connected to each other.

[0016] like Figure 2 As shown, the check diaphragm 2 has a liquid inlet membrane core 20 and a liquid outlet membrane core 21, the liquid inlet membrane core 20 is located in the liquid inlet chamber 30, and the liquid outlet membrane core 21 is located in the liquid outlet chamber 31. The valve cover 1 is provided with a liquid inlet 10 and a liquid outlet 11, the liquid inlet 10 is communicated with the liquid inlet chamber 30, and the liquid outlet 11 is communicated with the liquid outlet chamber 31; Figure 3 and Figure 4 As shown, the check valve seat 3 is provided with an overflow hole 32 (the overflow hole 32 is a small hole), an intermediate hole 33 and a liquid outlet hole 34, the overflow hole 32 and the intermediate hole 33 are both communicated with the liquid inlet chamber 30, and the liquid outlet hole 34 is communicated with the liquid outlet chamber 31; in addition, the liquid inlet membrane core 20 of the check diaphragm 2 covers the liquid inlet 10 and is staggered with the overflow hole 32 and the intermediate hole 33 (here, "covering" means that the liquid inlet membrane core 20 has an area that can completely cover the liquid inlet 10, and "staggered" means that the liquid inlet membrane core 20 does not cover the overflow hole 32 and the intermediate hole 33), and the liquid outlet membrane core 21 of the check diaphragm 2 covers the liquid outlet hole 34 and is staggered with the liquid outlet 11 (here, "covering" means that the liquid outlet membrane core 21 has an area that can completely cover the liquid outlet hole 34, and "staggered" means that the liquid outlet membrane core 21 does not cover the liquid outlet 11; as shown Figure 2 and Figure 3 As shown, the auxiliary pump 4 has a power source 42 (a driving iron core) and a diaphragm cover 40 (made of rubber material). The power source 42 is transmission-connected to the diaphragm cover 40. A sealed pump chamber 35 is formed between the diaphragm cover 40 and the check valve seat 3. The overflow hole 32, the liquid outlet hole 34 and the middle hole 33 are all connected to the sealed pump chamber 35. A sealing protrusion 41 for blocking the middle hole 33 is provided on the diaphragm cover 40.

[0017] The working principle of the present invention is as follows: Figure 1 As shown in FIG. 1 , when the main pump 7 pumps liquid normally, the injector 6 sprays liquid normally, and a small amount of urea liquid overflows into the urea tank 8. Figure 2 and 6As shown, when the main pump 7 pumps liquid normally, the auxiliary pump 4 does not work, and the sealing protrusion 41 of the membrane cover 40 of the auxiliary pump 4 blocks the middle hole 33 of the check valve seat 3. Since the liquid inlet 10 of the valve cover 1 has the hydraulic pressure given by the main pump 7, urea enters the liquid inlet chamber 30 from the liquid inlet 10 of the valve cover 1. Since the liquid inlet membrane core 20 of the check diaphragm 2 is staggered with the overflow hole 32 of the check valve seat 3, the urea entering from the liquid inlet 10 of the valve cover 1 passes through the check valve seat The overflow hole 32 of 3 enters into the sealed pump chamber 35 formed between the membrane cover 40 and the check valve seat 3. Under the pressure of urea liquid, the liquid in the sealed pump chamber 35 pushes the liquid outlet membrane core 21 of the check diaphragm 2 to move upward, and urea enters into the liquid outlet chamber 31. Since the liquid outlet membrane core 21 of the check diaphragm 2 is staggered with the liquid outlet 11 of the valve cover 1, the urea flows out from the liquid outlet 11 of the valve cover 1 and finally overflows into the urea tank 8, thereby realizing urea overflow.

[0018] Before the system stops working, the urea in the injector 6 and the pipeline needs to be refluxed, at which time the main pump 7 stops working and the auxiliary pump 4 starts working. Figure 2 and Figure 7 As described above, when the power source 42 of the auxiliary pump 4 drives the diaphragm cover 40 to move downward (the sealing protrusion 41 of the diaphragm cover 40 no longer blocks the middle hole 33 of the check valve seat 3), as shown in FIG. Figure 7 At ① in the figure, the membrane cover 40 generates a negative pressure inside the sealed pump chamber 35, thereby driving the inlet membrane core 20 and the outlet membrane core 21 of the check diaphragm 2 to move downward ( Figure 7 In the downward direction), since the liquid inlet membrane core 20 of the check diaphragm 2 and the overflow hole 32 and the middle hole 33 of the check valve seat 3 are staggered, and the liquid outlet membrane core 21 of the check diaphragm 2 covers the liquid outlet hole 34 of the check valve seat 3, urea can only enter the liquid inlet chamber 30 from the liquid inlet port 10 of the valve cover 1, and then enter the sealed pump chamber 35 through the overflow hole 32 and the middle hole 33 of the check valve seat 3; then, when the power source 42 of the auxiliary pump 4 drives the membrane cover 40 to move upward ( Figure 7 ), such as Figure 7 At ② in the figure, the membrane cover 40 pushes the urea liquid in the sealed pump chamber 35 to flow upward. Since the liquid inlet membrane core 20 of the check diaphragm 2 covers the liquid inlet 10 of the valve cover 1, and the liquid outlet membrane core 21 of the check diaphragm 2 is staggered with the liquid outlet 11 of the valve cover 1, the urea liquid can only enter the liquid outlet chamber 31 through the liquid outlet hole 34 of the check valve seat 3, and then flow out from the liquid outlet 11 of the valve cover 1. In this way, the power source 42 drives the membrane cover 40 to reciprocate up and down, and finally refluxes the urea in the injector 6 and the pipeline into the urea tank 8, thereby realizing urea reflux.

[0019] Through the above structure, the present invention can integrate urea reflux and urea overflow, thereby greatly optimizing the product structure, simplifying the assembly steps, and reducing the manufacturing cost.

[0020] Finally, it is worth mentioning that the check diaphragm 2 has a sealing ring portion 22 and a sealing middle portion 23. The liquid inlet membrane core 20 and the liquid outlet membrane core 21 are located in the sealing ring portion 22, and the sealing middle portion 23 separates the liquid inlet membrane core 20 from the liquid outlet membrane core 21. The sealing ring portion 22 of the check diaphragm 2 seals the valve cover 1 and the check valve seat 3 to form a chamber, and the sealing middle portion 23 of the check diaphragm 2 seals the chamber to separate the liquid inlet chamber 30 from the liquid outlet chamber 31.

Claims

1. A novel urea pump assembly, comprising a main pump (7) and an auxiliary pump (4), characterized in that: The auxiliary pump (4) has a flow-limiting check valve structure, the flow-limiting check valve structure comprising a valve cover (1), a check valve seat (3) and a check diaphragm (2), a chamber is formed between the valve cover (1) and the check valve seat (3), the check diaphragm (2) is located in the chamber and divides the chamber into a liquid inlet chamber (30) and a liquid outlet chamber (31), the check diaphragm (2) has a liquid inlet membrane core (20) and a liquid outlet membrane core (21 ), the liquid inlet membrane core (20) is located in the liquid inlet chamber (30), the liquid outlet membrane core (21) is located in the liquid outlet chamber (31), the valve cover (1) is provided with a liquid inlet (10) and a liquid outlet (11), the liquid inlet (10) is communicated with the liquid inlet chamber (30), the liquid outlet (11) is communicated with the liquid outlet chamber (31), and the check valve seat (3) is provided with an overflow hole (32) and an intermediate hole (33) and a liquid outlet hole (34), the overflow hole (32) and the middle hole (33) are both in communication with the liquid inlet chamber (30), the liquid outlet hole (34) is in communication with the liquid outlet chamber (31), the liquid inlet membrane core (20) covers the liquid inlet port (10) and is staggered with the overflow hole (32) and the middle hole (33), the liquid outlet membrane core (21) covers the liquid outlet hole (34) and is staggered with the liquid outlet port (11), and the auxiliary pump (4) having a power source (42) and a membrane cover (40), wherein the power source (42) is drivingly connected to the membrane cover (40), a sealed pump chamber (35) is formed between the membrane cover (40) and the check valve seat (3), the overflow hole (32), the liquid outlet hole (34) and the middle hole (33) are all in communication with the sealed pump chamber (35), and the membrane cover (40) is provided with a sealing protrusion (41) for blocking the middle hole (33).

2. The novel urea pump assembly according to claim 1 is characterized in that: The non-return diaphragm (2) comprises a sealing ring portion (22) and a sealing middle portion (23); the liquid inlet membrane core (20) and the liquid outlet membrane core (21) are located inside the sealing ring portion (22); and the sealing middle portion (23) separates the liquid inlet membrane core (20) from the liquid outlet membrane core (21).

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