Urea pump assembly and method for preventing frost crack

Abstract

The invention discloses a frost crack prevention urea pump assembly which comprises a urea pump assembly, a coil pipe and a fixing clamp, the coil pipe and the urea pump assembly are installed on a shell of the urea pump assembly through the fixing clamp, and the frost crack prevention urea pump assembly is characterized in that the frost crack prevention urea pump assembly further comprises a first elastic object which is arranged in the coil pipe; the middle part extends along with the shape of the coil pipe, and two ends respectively extend to the water inlet end and the water outlet end of the coil pipe; and the cross sectional area of the first elastic object is smaller than that of the inner cavity of the coil pipe. The urea pump assembly has the advantages that the swelling capacity can be automatically absorbed, the use difficulty is low, the application cost is low, and parts of the urea pump assembly can be effectively prevented from being frozen and spalling.

Description

Technical Field

[0001] The present invention relates to the technical field of urea pump anti-freezing, in particular to a urea pump assembly and method for preventing freezing and cracking. Background Art

[0002] In current internal combustion engine exhaust gas purification systems, especially lean-burn internal combustion engines such as diesel engines, a reactant, such as an aqueous urea solution reactant (hereinafter referred to as "reactant"), needs to be added to the exhaust system, i.e., the after-treatment device, to reduce nitrogen oxides (NOx). The national standard reactant is a 32.5% aqueous urea solution. In engineering applications, this reactant is carried on board in a urea tank and is pumped and sprayed into the after-treatment device, such as an SCR system, by a urea pump under the control of a DCU (after-treatment controller) according to the operating conditions of the vehicle engine. However, the above national standard reactant freezes at low temperatures, such as -11°C. Therefore, a heating system is required to heat and thaw the reactant. The most common method is to use the engine cooling circulating water as the heating medium, hereinafter referred to as "circulating water", and a heat exchanger, hereinafter referred to as "coil", is arranged in the urea tank to introduce the circulating water into the coil for circulation; in this way, the heat brought by the circulating water from the engine is conducted to the reactant to achieve heating and thawing of the reactant. For example, the existing patent documents CN222066865U and CN216950529U.

[0003] Users replace the engine cooling water (with a minimum freezing point of -35°C to -45°C) with tap water, and the circulating water flow path of the urea pump is filled with water. Therefore, in winter at low temperatures, the water remaining in the urea pump freezes and expands, causing varying degrees of damage to multiple positions of the circulating water flow path of the urea pump, resulting in product failure. Common damage locations include:

[0004] Plug heads of all process holes on the urea pump housing;

[0005] Filter heating triangular flow path;

[0006] All joints of the coil, urea pipe, wire pipe, liquid level sensor device and the housing;

[0007] The coil is distorted and deformed.

[0008] The existing patent document CN222596160U discloses a device for preventing the heating system of the reactant from freezing and cracking. By arranging at least one pressure relief valve at the slowest-cooling part of the coil and the flow path connected thereto, the pressure of the circulating water in the coil and the flow path, i.e., the heating medium, can be released, avoiding the heating system (including the coil, the flow path and other related components) from being frozen and cracked due to the freezing and volume expansion of the circulating water. This solution requires adding at least one valve and further processing of the coil, resulting in high costs.

[0009] The disclosure of the above background art content is only for assisting in understanding the concept and technical solution of the present invention, and it does not necessarily belong to the prior art of this patent application. Without clear evidence indicating that the above content was publicly available on the filing date of this patent application, the above background art should not be used to evaluate the novelty and inventiveness of this application. Summary of the Invention

[0010] The main object of the present invention is to propose a urea pump assembly and method for preventing freezing and cracking, which have no additional parts added, do not require manual operation by the user, can automatically absorb expansion, have low usage difficulty, and low application cost.

[0011] To this end, the present invention proposes a urea pump assembly and method for preventing freezing and cracking.

[0012] Preferably, the present invention may further have the following technical features:

[0013] The urea pump assembly for preventing freezing and cracking includes a urea pump assembly, a coiled pipe, and a fixing fixture. The coiled pipe and the urea pump assembly are installed on the housing of the urea pump assembly through the fixing fixture, and further includes a first elastic member. The first elastic member is disposed inside the coiled pipe, and its middle part extends along the shape of the coiled pipe, and its two ends respectively extend to the water inlet end and the water outlet end of the coiled pipe; the cross-sectional area of the first elastic member is smaller than the cross-sectional area of the inner cavity of the coiled pipe.

[0014] Preferably, the first elastic member is of a solid structure.

[0015] Preferably, the first elastic member is a foaming material.

[0016] Preferably, the first elastic member is a foaming silicone strip.

[0017] Preferably, it further includes a spring, and the spring is wrapped outside the first elastic member.

[0018] Preferably, the length of the spring is longer than the length of the first elastic member.

[0019] Preferably, the first elastic member is an EPDM foaming material.

[0020] Preferably, it further includes a fixing chuck. The two ends of the first elastic member are respectively provided with the fixing chuck. One end of the fixing chuck clamps the end of the first elastic member, and its outer side is in interference fit or clamped with the inner wall of the coiled pipe.

[0021] Preferably, the fixing chuck includes a hollow cylinder. Along the axial direction of one end of the hollow cylinder, a plurality of expansion ribs are distributed at intervals around it, and the expansion ribs are used for clamping the end of the first elastic member.

[0022] A method of using a urea pump assembly to prevent freezing. Fill a first elastic material inside the coil in the urea pump assembly, such that the cross-sectional area of the first elastic material is smaller than the cross-sectional area of the inner cavity of the coil, and the difference between the cross-sectional area of the first elastic material and the cross-sectional area of the inner cavity of the coil is greater than the valve port of the solenoid valve in the urea pump assembly.

[0023] The beneficial effects of the present invention compared with the prior art include: by adding an elastic material in the coil, the water accumulation in the coil is reduced. When the water retained in the coil freezes, the water expands and squeezes the elastic material to deform, and the elastic material absorbs the pressure of the volume expansion of the water expansion, thereby preventing the coil from deforming and avoiding the joint between the coil and the urea pump from being cracked. That is to say, in this embodiment, the elastic deformation characteristics of the first elastic material are used to provide an expansion space for the expansion of the frozen water, preventing the coil from being cracked by the frozen water. Description of the Drawings

[0024] Figure 1 is a diagram of the existing urea pump assembly.

[0025] Figure 2 is a partial cross-sectional view of the coil of the present invention.

[0026] Figure 3 is an assembly diagram of the first elastic material and the spring of the present invention.

[0027] Figure 4 is a cross-sectional view of the coil of the present invention.

[0028] Figure 5 is an installation diagram of the fixed chuck of the present invention.

[0029] Figure 6 is a cross-sectional view of the urea pump assembly of the present invention.

[0030] Figure 7 is a schematic diagram of the expansion of the elastic filler of the present invention.

[0031] Figure 8 is a schematic diagram of the tubular elastic filler of the present invention. The elastic filler in this embodiment is a circular tubular structure. Detailed Description of the Embodiment

[0032] The present invention will be further described in detail below in conjunction with the specific embodiments and with reference to the accompanying drawings. It should be emphasized that the following description is merely exemplary and not intended to limit the scope of the present invention and its applications.

[0033] Referring to the following drawings, non-limiting and non-exclusive embodiments will be described, in which like reference numerals represent like components, unless otherwise specifically stated.

[0034] Such as Figures 2 to 8The urea pump assembly for preventing frost cracking shown in the figure includes a urea pump assembly 2, a coiled pipe 1 and a fixing clamp. The coiled pipe 2 is installed on the urea pump assembly 1 through the fixing clamp. The coiled pipe 2 and the urea pump assembly 1 adopt an existing installation method. It further includes a first elastic member 13. The first elastic member 13 is arranged inside the coiled pipe 1. The middle part thereof extends along the shape of the coiled pipe 1, and its two ends respectively extend to the water inlet end and the water outlet end at the upper end of the coiled pipe 1. The cross-sectional area of the first elastic member 13 is smaller than the cross-sectional area of the inner cavity of the coiled pipe 1. In some embodiments, the two ends of the first elastic member 13 extend out from the water inlet end and the water outlet end of the coiled pipe 1. Preferably, the first elastic member 13 is a solid structure, such as a cylindrical bar structure, so that the diameter of the first elastic member 13 is smaller than the inner diameter of the inner cavity of the coiled pipe 1. In this way, there is a gap between the first elastic member 13 and the inner cavity of the coiled pipe 1. The water entering the coiled pipe 1 flows through this gap and flows out from the water outlet end of the coiled pipe 1. The solid-structured first elastic member 13 helps the heated cooling water to contact the inner wall of the coiled pipe 1, heats the coiled pipe 1, and further heats the urea solution in the urea tank. By adding the first elastic member 13 in the coiled pipe 1, the water accumulation in the coiled pipe 1 is reduced. When the water staying in the coiled pipe 1 freezes, the water expands and squeezes the first elastic member 13 to deform. The first elastic member 13 absorbs the pressure of the water freezing and expanding, thereby reducing the damage of the freezing expansion force to the coiled pipe. For example, it can prevent the coiled pipe 1 from deforming and avoid the joint between the coiled pipe 1 and the urea pump assembly 1 from being cracked. That is to say, in this embodiment, the elastic deformation characteristic of the first elastic member 13 is used to provide an expansion space for the water freezing and expanding, preventing the water from freezing and cracking the coiled pipe.

[0035] In a preferred embodiment, the first elastic member 13 is a foamed material, such as a foamed silica gel strip. Further, it further includes a spring 11. The spring 11 is wrapped outside the first elastic member 13. Preferably, the length of the spring 11 is longer than the length of the first elastic member 13. In this embodiment, the spring 11 is used to wrap the first elastic member 13 and is rotated through the inner cavity of the coiled pipe 1, which is simple to operate. Moreover, the rigidity of the spring 11 can avoid the risk of the first elastic member 13 piling up and blocking the inner cavity of the coiled pipe 1, and does not isolate the contact between the heated water and the pipe wall, ensuring the flow rate and not affecting the heating and thawing effect on the urea. In addition, the spring 11 and the first elastic member 13 can also be integrated. It can be seen that by adding the spring 11, it can also prevent the first elastic member 13 from bending and blocking the flow channel in the coiled pipe 1, improving the effectiveness of the first elastic member 13. Or, the first elastic member 13 is an EPDM foamed material.

[0036] For a further improvement, it further includes a fixing chuck 12. The fixing chuck 12 is provided at both ends of the first elastic member 13. One end of the fixing chuck 12 clamps the end of the first elastic member 13, and its outer side is in interference fit or clamped with the inner wall of the coiled pipe 1, further preventing the first elastic member 13 from bending and piling up to cause blockage of the internal flow of the coiled pipe.

[0037] The fixed chuck 12 includes a hollow cylinder. Around the periphery of one end of the hollow cylinder, a plurality of expansion ribs 122 are distributed at intervals along its axial direction. The expansion ribs 122 are used for clamping the end of the first elastic member 13. Please note that the intervals between the expansion ribs 122 can also serve as channels for the flow of cooling water.

[0038] In a preferred embodiment, the fixed chuck 12 is internally clamped to the coil pipe 1. For example, radial convex rings 15 are respectively provided at the water inlet end and the water outlet end of the coil pipe 1, and annular concave rings are formed at the corresponding positions on the inner side of the coil pipe 1. As a match, an arc-shaped section convex rib 121 for mating with the concave ring is provided on the outer side of each expansion rib 122 of the fixed chuck 12, and the convex ribs 121 of each section are on the same concentric circle. In this way, by the clamping fit between the convex rib 121 and the concave ring, the position of the fixed chuck 12 installed inside the coil pipe 1 is fixed, preventing the fixed chuck 12 from axially moving.

[0039] The urea pump assembly includes a housing 29, as well as a water inlet pipe 24, a water outlet pipe 21, a heating water filter screen, and a solenoid valve 27 provided on the housing 29. The structure of the urea pump assembly 2 is a publicly known structure. The purpose of this embodiment is to solve the problem of the pipeline being frozen and cracked on the basis of the publicly known urea pump assembly solution. As an improvement, an elastic filler 30 is provided in the water inlet pipe 24 and the water outlet pipe 21. Utilizing the characteristic that the elastic filler 30 has a certain compression amount, when the engine cooling water freezes into ice in the water inlet pipe 24 and the water outlet pipe 21, the elastic filler 30 deforms to provide space for the expansion of the cooling water when it freezes, avoiding the joints of the water inlet pipe 24 and the water outlet pipe 21 from being cracked by the freezing of the cooling water. According to the existing technical situation, a water inlet joint 23 and a water outlet joint 22 are respectively installed on the water inlet pipe 24 and the water outlet pipe 21 of the housing 29. When installing the elastic filler 30, first install the elastic filler 30 into the water inlet pipe 24 and the water outlet pipe 21, and then install the water inlet joint 23 and the water outlet joint 22. Specifically, the water inlet pipe 24 and the water outlet pipe 21 are pipe cavities opened in the housing 29. For example, the elastic filler 30 is applied to a urea pump disclosed in CN215521215U, thereby preventing the water inlet joint and the water outlet joint from being cracked by the freezing of the cooling water.

[0040] Generally, a plurality of process holes for connecting the water inlet pipe and the water outlet pipe, such as holes 25 and 26, are also provided on the housing 29, and the elastic filler 30 is provided in the process holes. The hole 28 for installing the heating water filter screen is also installed with the elastic filler 30.

[0041] The solenoid valve 27 is used to control the flow rate of the heating water to open the heating water flow channel in a low-temperature state.

[0042] The elastic filler 30 is tubular, and its material can be selected from a foamed silica gel tube or an EPDM foamed material. Preferably, a second spring 31 is provided in the inner cavity of the elastic filler 30, and the length of the second spring 31 is the same as the length of the elastic filler 30, or the length of the second spring 31 is greater than the length of the elastic filler 30. Different specifications of the elastic filler 30 are selected according to the application scenario, so that the outer side of the elastic filler 30 contacts the inner wall of the water inlet pipe / water outlet pipe / process hole. The heated water mainly flows through the inner cavity of the elastic filler 30.

[0043] A method of using a urea pump assembly to prevent freezing, in which a first elastic material 13 is filled inside the coil 1 in the urea pump assembly, so that the cross-sectional area of the first elastic material 13 is smaller than the cross-sectional area of the inner cavity of the coil 1. Preferably, the difference between the cross-sectional area of the first elastic material 13 and the cross-sectional area of the inner cavity of the coil 1 is greater than the valve port of the solenoid valve 27 in the urea pump assembly.

[0044] In the above solution, the overall flow rate is restricted at the valve port of the solenoid valve 27. After the water inlet pipe 24, the water outlet pipe 21, the coil 1, etc. are filled with foamed materials, their respective remaining cross-sectional areas are larger than the valve port of the solenoid valve 27, so the overall flow rate will not be affected. That is to say, the remaining cross-sectional area (including the inner cavity cross-sectional area of the elastic filler 30) of the water inlet pipe 24 after filling with the elastic filler 30, the remaining cross-sectional area (including the inner cavity cross-sectional area of the elastic filler 30) of the water outlet pipe 21 after filling with the elastic filler 30, and the remaining cross-sectional area of the coil 1 after filling with the first elastic material 13 are all larger than the cross-sectional area of the valve port of the solenoid valve 27. More preferably, the inner cavity cross-sectional area of the tubular elastic filler 30 is larger than the cross-sectional area of the valve port of the solenoid valve 27.

[0045] Scheme test:

[0046] Project A, water resistance test, the fillers (the first elastic material 13, the elastic filler 30) are completely immersed in water and placed in a high temperature of 95 °C for 400 h. After the test, the filler material did not show dissolution, slagging, and the volume did not change significantly. After filtering with a 200-micron filter screen, the residue was less than 0.5 g.

[0047] Project B, antifreeze resistance test, the fillers are completely immersed in antifreeze and placed in a normal temperature of 95 °C for 400 h. After the test, the filler material did not show dissolution, slagging, and the volume did not change significantly. After filtering with a 200-micron filter screen, the residue was less than 0.5 g.

[0048] Those skilled in the art will recognize that many modifications to the above description are possible, so the embodiments and the drawings are only used to describe one or more specific embodiments.

[0049] Although the exemplary embodiments considered to be the present invention have been described and recited, those skilled in the art will understand that various changes and substitutions can be made thereto without departing from the spirit of the present invention. Additionally, many modifications can be made to adapt a particular situation to the teachings of the present invention without departing from the central concept of the present invention described herein. Therefore, the present invention is not limited to the specific embodiments disclosed herein, but the present invention may also include all embodiments and their equivalents falling within the scope of the present invention.

Claims

1. The urea pump assembly for preventing freezing and cracking, comprising a urea pump assembly, a coiled pipe and a fixing clamp, wherein the coiled pipe and the urea pump assembly are installed on the housing of the urea pump assembly through the fixing clamp, and is characterized in that: It further includes a first elastic member disposed inside the coiled pipe, the middle part of which extends along the shape of the coiled pipe, and both ends thereof extend to the water inlet end and the water outlet end of the coiled pipe respectively; the cross-sectional area of the first elastic member is smaller than the cross-sectional area of the inner cavity of the coiled pipe.

2. The urea pump assembly for preventing frost cracking according to claim 1, characterized in that: The first elastic member is of a solid structure.

3. The urea pump assembly for preventing frost cracking according to claim 1, wherein: The first elastic member is a foaming material.

4. The urea pump assembly for preventing frost cracking according to claim 2 or 3, wherein: The first elastic member is a foaming silica gel strip.

5. The urea pump assembly for preventing frost cracking according to claim 4, characterized in that: It further includes a spring wrapped outside the first elastic member.

6. The anti-freezing urea pump assembly according to claim 5, wherein: The length of the spring is longer than the length of the first elastic member.

7. The anti-freezing urea pump assembly according to claim 1, characterized in that: The first elastic member is an EPDM foaming material.

8. The urea pump assembly for preventing frost cracking according to claim 1, characterized in that: It further includes fixing chucks, and the fixing chucks are provided at both ends of the first elastic member. One end of the fixing chuck clamps the end of the first elastic member, and its outer side is in interference fit or clamped with the inner wall of the coiled pipe.

9. The urea pump assembly for preventing frost cracking according to claim 8, wherein: The fixing chuck includes a hollow cylinder, and a plurality of expansion ribs are distributed at intervals along the axial direction around one end of the hollow cylinder, and the expansion ribs are used for clamping the end of the first elastic member.

10. A method for using a urea pump assembly to prevent freezing and cracking, characterized in that: Fill the inside of the coiled pipe in the urea pump assembly with a first elastic member, so that the cross-sectional area of the first elastic member is smaller than the cross-sectional area of the inner cavity of the coiled pipe, and the difference between the cross-sectional area of the first elastic member and the cross-sectional area of the inner cavity of the coiled pipe is greater than the valve port of the solenoid valve in the urea pump assembly.

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