CN212376725U

CN212376725U - Hydraulic pressure stabilizing mechanism for urea pump

Info

Publication number: CN212376725U
Application number: CN202020962792.1U
Authority: CN
Inventors: 尹乐; 臧志成; 刘德文; 曾伟; 刘印; 高殿朋; 王�锋
Original assignee: Kailong High Technology Co Ltd
Current assignee: Kailong High Technology Co Ltd
Priority date: 2020-05-29
Filing date: 2020-05-29
Publication date: 2021-01-19
Anticipated expiration: 2030-05-29

Abstract

The utility model discloses a hydraulic pressure stabilizing mechanism for urea pump, the air-free auxiliary type urea solution feed pump who is applicable to diesel engine selectivity catalytic conversion system, it includes urea pump steady voltage chamber casing and steady voltage elastic component, the steady voltage chamber that is linked together with the urea pump chamber has in the urea pump steady voltage chamber casing, install the steady voltage elastic component that can contract automatically or expand along with urea pump chamber pressure change in the steady voltage intracavity, normal during operation, steady voltage elastic component is full of urea solution outward, and steady voltage elastic component is in the contraction state. The hydraulic pressure stabilizing mechanism for the urea pump is simple in structure and convenient to install; and the influence of the pressure fluctuation on the metering precision and the atomization effect of the urea injection system during the operation of the urea pump can be compensated, the damage of parts in the urea pump caused by the low-temperature icing expansion of the urea solution can be avoided, and the stability and the reliability of the operation of the urea pump are improved.

Description

Hydraulic pressure stabilizing mechanism for urea pump

Technical Field

The utility model relates to an air-free auxiliary formula urea solution feed pump especially relates to a hydraulic pressure stabilizing mechanism for urea pump suitable for diesel engine selectivity catalytic conversion system.

Background

Nitrogen oxide (NOx) contained in the exhaust gas discharged from diesel engines causes serious pollution to the atmospheric environment, and directly affects the ecological environment and human health. At present, the tail gas treatment of the diesel engine is mainly realized by a Selective Catalytic Reduction (SCR) system, and the system needs to atomize and quantitatively spray a standard urea solution for vehicles into an exhaust system by a urea pump, and catalytically reduces NOx into harmless nitrogen and water by a catalyst to realize the purpose of tail gas treatment.

The conventional airless auxiliary urea pump is usually matched with an electric control nozzle for use, the injection quantity of the urea solution is metered and controlled through the urea nozzle, and a series of simulation analysis and test results show that the pressure fluctuation of the urea solution has obvious influence on the metering precision and the atomization effect of a urea injection system. And the urea pump is easy to break down in cold climate areas (lower than-11 ℃), because the residual urea solution in the urea pump freezes and expands in the low temperature environment after the urea pump stops working for a period of time, and the parts in the urea pump, which are in direct contact with the urea solution, are extruded to cause damage, so that the urea pump breaks down and cannot work normally.

The above problems seriously affect the performance and the operation stability of the selective catalytic reduction system, and affect the normal running of a vehicle equipped with the selective catalytic reduction system, and are a technical problem to be solved urgently in the field.

SUMMERY OF THE UTILITY MODEL

An object of the utility model is to provide a hydraulic pressure stabilizing mechanism for urea pump to solve the urea pump that is used for diesel engine selectivity catalytic conversion system among the prior art and have the problem that causes spare part to damage in the pump because of the frozen inflation of pressure fluctuation influence measurement accuracy and atomization effect and urea solution low temperature.

To achieve the purpose, the utility model adopts the following technical proposal:

a hydraulic pressure stabilizing mechanism for a urea pump comprises a urea pump pressure stabilizing cavity shell and a pressure stabilizing elastic piece, wherein a pressure stabilizing cavity communicated with a urea pump cavity is arranged in the urea pump pressure stabilizing cavity shell, the pressure stabilizing elastic piece capable of automatically contracting or expanding along with the pressure change in the urea pump cavity is arranged in the pressure stabilizing cavity, and during normal work, the pressure stabilizing elastic piece is filled with urea solution and is in a contracting state.

Particularly, the outer end of the pressure stabilizing cavity is opened, the pressure stabilizing elastic piece is assembled on a shell of the pressure stabilizing cavity of the urea pump through the opening, and the opening end of the pressure stabilizing cavity is hermetically assembled with a pressure stabilizing cover plate.

Particularly, the pressure stabilizing elastic part comprises a telescopic sheath and a pressure stabilizing spring, one end of the telescopic sheath is open, the other end of the telescopic sheath is closed, the open end of the telescopic sheath is hermetically assembled between the pressure stabilizing cover plate and the urea pump pressure stabilizing cavity shell, the closed end of the telescopic sheath extends into the pressure stabilizing cavity, the pressure stabilizing spring is arranged in the telescopic sheath, and the two ends of the pressure stabilizing spring always apply elasticity to the closed ends of the pressure stabilizing cover plate and the telescopic sheath.

Particularly, the opening end of the telescopic sheath is fixedly provided with a fixed spring seat, the closed end of the telescopic sheath is provided with a movable spring seat, one end of the pressure stabilizing spring is sleeved on the fixed spring seat, and the other end of the pressure stabilizing spring is sleeved on the movable spring seat.

Particularly, the fixed spring seat and the telescopic sheath are arranged in a sealing mode, a center hole is formed in the center of the fixed spring seat, the cross section of the movable spring seat is of a T-shaped structure and comprises a disc-shaped seat body, a push rod extends towards one side of the center of the seat body, and the push rod penetrates through the center hole.

Particularly, the pressure stabilizing cover plate is provided with air holes corresponding to the central hole, and the air holes are communicated with the outside, so that the pressure stabilizing elastic piece can contract or expand to exhaust smoothly.

Particularly, the open end integrated into one piece of flexible sheath has the round sealing washer, corresponds to be provided with the round seal groove on the inner wall of the open end of urea pump steady voltage chamber casing, the sealing washer is installed in the seal groove, steady voltage apron and sealing washer form end face seal, urea pump steady voltage chamber casing and sealing washer form radial seal.

Particularly, a limiting part and a guiding part which are mutually matched are arranged between one end of the ejector rod penetrating into the central hole and the central hole, so that the stable reliability of the contraction or expansion of the pressure stabilizing elastic part is ensured, and the ejector rod is prevented from falling off from the central hole.

The hydraulic pressure stabilizing mechanism for the urea pump has the advantages that compared with the prior art, the hydraulic pressure stabilizing mechanism for the urea pump is simple in structure and convenient to install; and the influence of the pressure fluctuation on the metering precision and the atomization effect of the urea injection system during the operation of the urea pump can be compensated, the damage of parts in the urea pump caused by the low-temperature icing expansion of the urea solution can be avoided, and the stability and the reliability of the operation of the urea pump are improved.

Drawings

FIG. 1 is a cross-sectional view of a hydraulic pressure stabilizing mechanism for a urea pump according to an embodiment of the present invention;

fig. 2 is an exploded view of a pressure stabilizing elastic member of a hydraulic pressure stabilizing mechanism for a urea pump according to an embodiment of the present invention.

Detailed Description

The technical solution of the present invention is further explained by the following embodiments with reference to the accompanying drawings.

In order to facilitate understanding of the present invention, the present invention will be described more fully hereinafter with reference to the accompanying drawings. The preferred embodiments of the present invention are shown in the drawings. The invention may, however, be embodied in many different forms and should not be construed as limited to the embodiments set forth herein. Rather, these embodiments are provided so that this disclosure will be thorough and complete. It will be understood that when an element is referred to as being "secured to" another element, it can be directly on the other element or intervening elements may also be present. When an element is referred to as being "connected" to another element, it can be directly connected to the other element or intervening elements may also be present. The terms "vertical," "horizontal," "left," "right," and the like as used herein are for illustrative purposes only and do not represent the only embodiments. Unless defined otherwise, all technical and scientific terms used herein have the same meaning as commonly understood by one of ordinary skill in the art to which this invention belongs. The terminology used in the description of the invention herein is for the purpose of describing particular embodiments only and is not intended to be limiting of the invention. As used herein, the term "and/or" includes any and all combinations of one or more of the associated listed items.

Referring to fig. 1 and 2, in this embodiment, a hydraulic pressure stabilizing mechanism for a urea pump is suitable for an air-free auxiliary urea solution supply pump of a diesel engine selective catalytic conversion system, and includes a urea pump pressure stabilizing cavity housing 1, a telescopic sheath 2 and a pressure stabilizing spring 3, where the telescopic sheath 2 is made of rubber, a pressure stabilizing cavity 4 communicated with a urea pump cavity is provided in the urea pump pressure stabilizing cavity housing 1, an outer end of the pressure stabilizing cavity 4 is open, an open end of the pressure stabilizing cavity 4 is equipped with a pressure stabilizing cover plate 5, one end of the telescopic sheath 2 is open, the other end is closed, an open end of the telescopic sheath 2 is hermetically assembled between the pressure stabilizing cover plate 5 and the urea pump pressure stabilizing cavity housing 1, and a closed end extends into the pressure stabilizing cavity 4. The specific sealing structure is as follows: a circle of sealing ring 14 is integrally formed at the opening end of the telescopic sheath 2, a circle of sealing groove 6 is arranged on the inner wall corresponding to the opening end of the urea pump pressure stabilizing cavity shell 1, the sealing ring 14 is arranged in the sealing groove 6, the pressure stabilizing cover plate 5 and the sealing ring 14 form end face sealing, and the urea pump pressure stabilizing cavity shell 1 and the sealing ring 14 form radial sealing.

Pressure stabilizing spring 3 assembles in flexible sheath 2 through fixed spring seat 7 and movable spring seat 8, fixed spring seat 7 is installed in the open end of flexible sheath 2, it sets up with flexible sheath 2 is sealed, movable spring seat 8 is installed in the blind end of flexible sheath 2, pressure stabilizing spring 3's one end cover is on fixed spring seat 7, the other end overlaps on movable spring seat 8, fixed spring seat 7 center department has seted up

centre bore

9, 8 cross-sections of movable spring seat are "T" type structure, it includes the pedestal 10 of disc, the center department of pedestal 10 has ejector pin 11 to one side extension, ejector pin 11 penetrates centre bore 9 and sets up, the inner wall of flexible sheath 2's sealed end is hugged closely all the time to pedestal 10.

The pressure stabilizing cover plate 5 is provided with air holes 12 corresponding to the central hole 9, and the air holes 12 are communicated with the outside to ensure the smooth contraction or expansion and exhaust of the telescopic sheath 2 and the pressure stabilizing spring 3.

The spacing and guide part 13 that are provided with mutual adaptation between the one end that ejector pin 11 penetrated centre bore 9 and center department 9 can guarantee the reliable and stable nature of steady voltage spring 3 shrink or inflation through spacing and guide part 13, avoids ejector pin 11 to drop from the centre bore 9 simultaneously.

During normal work, the telescopic sheath 2 is filled with urea solution, the pressure stabilizing spring 3 is in a contraction state, namely, the pressure stabilizing spring 3 applies elasticity to the closed ends of the pressure stabilizing cover plate 5 and the telescopic sheath 6 all the time, the rigidity and the effective stroke of the pressure stabilizing spring 3 are set according to target working pressure, the rigidity and the effective stroke of the pressure stabilizing spring 3 influence the response speed and the pressure compensation and inhibition of liquid pressure fluctuation regulation, and the effective stroke of the pressure stabilizing spring 3 also influences the liquid freezing expansion volume absorption capacity.

The pressure stabilizing mechanism is applied to a urea pump product and mainly plays two roles as follows:

1. and under the action of stable pressure, the pressure in the hydraulic cavity is compensated or inhibited through the change of the compression stroke of the pressure stabilizing spring 3 according to the actual pressure in the hydraulic cavity, so that the liquid pressure at the urea solution injection end is always kept near the target pressure. Namely, when the urea solution is sprayed from the urea nozzle at a certain frequency, the pressure in the urea pump is instantaneously reduced, and at the moment, the pressure stabilizing spring 3 begins to rebound from the previous compression amount to drive the telescopic sheath 2 to supplement the sprayed volume so as to maintain the set target pressure.

2. When liquid in the urea pump freezes and expands in a low-temperature environment, the pressure stabilizing spring 3 can counteract partial volume expansion amount of frozen urea through compression so as to protect internal parts of the urea pump. Namely, in the low temperature environment in winter, when the urea solution exists in the urea pump and icing expansion occurs, the pressure stabilizing spring 3 can start to compress at the previous compression amount, and drives the telescopic sheath 2 to move to offset the volume increased by the expansion of the urea solution, so as to protect the parts of the urea pump from being damaged by icing expansion force.

It should be noted that the foregoing is only a preferred embodiment of the present invention and the technical principles applied. It will be understood by those skilled in the art that the present invention is not limited to the particular embodiments described herein, but is capable of various obvious changes, rearrangements and substitutions as will now become apparent to those skilled in the art without departing from the scope of the invention. Therefore, although the present invention has been described in greater detail with reference to the above embodiments, the present invention is not limited to the above embodiments, and may include other equivalent embodiments without departing from the scope of the present invention.

Claims

1. A hydraulic pressure stabilizing mechanism for a urea pump is characterized by comprising a urea pump pressure stabilizing cavity shell and a pressure stabilizing elastic part, wherein a pressure stabilizing cavity communicated with a urea pump cavity is arranged in the urea pump pressure stabilizing cavity shell, the pressure stabilizing elastic part capable of automatically contracting or expanding along with the pressure change in the urea pump cavity is arranged in the pressure stabilizing cavity, and during normal work, the pressure stabilizing elastic part is filled with urea solution and is in a contracting state.

2. The hydraulic pressure stabilizing mechanism for the urea pump as recited in claim 1, wherein the outer end of the pressure stabilizing cavity is open, the pressure stabilizing elastic piece is assembled on the shell of the pressure stabilizing cavity of the urea pump through the opening, and the open end of the pressure stabilizing cavity is hermetically assembled with a pressure stabilizing cover plate.

3. The hydraulic pressure stabilizing mechanism for the urea pump as claimed in claim 2, wherein the pressure stabilizing elastic member comprises a telescopic sheath and a pressure stabilizing spring, one end of the telescopic sheath is open, the other end of the telescopic sheath is closed, the open end of the telescopic sheath is hermetically fitted between the pressure stabilizing cover plate and the urea pump pressure stabilizing cavity shell, the closed end of the telescopic sheath extends into the pressure stabilizing cavity, and the pressure stabilizing spring is arranged in the telescopic sheath, and both ends of the pressure stabilizing spring always apply elastic force to the pressure stabilizing cover plate and the closed end of the telescopic sheath.

4. The hydraulic pressure stabilizing mechanism for the urea pump as recited in claim 3, wherein the open end of the telescopic sheath is fixedly provided with a fixed spring seat, the closed end is provided with a movable spring seat, one end of the pressure stabilizing spring is sleeved on the fixed spring seat, and the other end of the pressure stabilizing spring is sleeved on the movable spring seat.

5. The hydraulic pressure stabilizing mechanism for the urea pump as recited in claim 4, wherein the fixed spring seat and the telescopic sheath are hermetically disposed, a central hole is formed at the center of the fixed spring seat, the cross section of the movable spring seat is of a "T" shaped structure, the movable spring seat comprises a disc-shaped seat body, a push rod extends from the center of the seat body to one side, and the push rod penetrates through the central hole.

6. The hydraulic pressure stabilizing mechanism for a urea pump as recited in claim 5, wherein said pressure stabilizing cover plate has a vent hole at a position corresponding to said central hole, said vent hole being in communication with the outside.

7. The hydraulic pressure stabilizing mechanism for the urea pump as recited in claim 3, wherein a ring of sealing ring is integrally formed at the open end of the telescopic sheath, a ring of sealing groove is formed on the inner wall corresponding to the open end of the urea pump pressure stabilizing cavity shell, the sealing ring is installed in the sealing groove, the pressure stabilizing cover plate and the sealing ring form an end face seal, and the urea pump pressure stabilizing cavity shell and the sealing ring form a radial seal.

8. The hydraulic pressure stabilizing mechanism for the urea pump as recited in claim 5, wherein a mutually adaptive limiting and guiding component is arranged between one end of the mandril penetrating into the central hole and the central hole.