CN210370867U

CN210370867U - Anti-freezing pressure switch for urea pump

Info

Publication number: CN210370867U
Application number: CN201920624246.4U
Authority: CN
Inventors: 臧志成; 刘印; 王云朋; 吴庆锋; 徐栋; 陈兴通
Original assignee: Kailong High Technology Co Ltd
Current assignee: Kailong High Technology Co Ltd
Priority date: 2019-04-30
Filing date: 2019-04-30
Publication date: 2020-04-21
Anticipated expiration: 2029-04-30

Abstract

The utility model discloses a type pressure switch prevents frostbite for urea pump, it includes the pressure switch body, wherein, the bottom of pressure switch body is provided with the bottom hole, the rubber cushion is installed to the bottom hole fit in, the through-hole has been seted up on the rubber cushion. When the anti-freezing pressure switch for the urea pump works normally, the rubber cushion block basically has no influence on the performance of the metering pump; when the metering pump does not work in a low-temperature environment (minus 11 ℃), the acting force generated by freezing and expanding of liquid in the hydraulic cavity of the pump body and the cavity below the pressure switch diaphragm is absorbed through the compression deformation of the rubber cushion block, so that the permanent deformation caused by the stress of the diaphragm and the baffle in the pressure switch is avoided, and the functionality of the pressure switch is effectively ensured. Not only the structure is simple, but also the design is ingenious; and the cost is low, and the safe and stable operation of the urea pump at low temperature is ensured.

Description

Anti-freezing pressure switch for urea pump

Technical Field

The utility model belongs to diesel engine selectivity catalytic conversion technique especially relates to a type pressure switch that prevents frostbite that has gas urea pump 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 pipe by a urea pump, and catalytically reduce NOx into harmless nitrogen and water by a catalyst to realize the purpose of tail gas treatment.

The existing urea pump is easy to have faults in cold climate areas (lower than-11 ℃), because the urea pump does not work for a long time, and the residual urea solution in the urea pump is frozen and expanded in a low-temperature environment, so that a pressure switch in the urea pump is damaged, and the urea pump has faults;

the above problems seriously affect the working stability of the urea pump and the normal running of the vehicle, and become a problem to be solved urgently by those skilled in the art.

SUMMERY OF THE UTILITY MODEL

An object of the utility model is to provide a type pressure switch prevents frostbite for urea pump to solve among the prior art urea pump and easily cause the problem that inside pressure switch damaged under low temperature environment.

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

the utility model provides a type pressure switch prevents frostbite for urea pump, its includes the pressure switch body, wherein, the bottom of pressure switch body is provided with the bottom hole, the bottom hole fit in installs the rubber cushion, the last through-hole of having seted up of rubber cushion.

Particularly, the rubber cushion block adopts a three-section reducing form to form a double-step structure, the rubber cushion block comprises a first cylindrical section, a second cylindrical section and a third cylindrical section, the radius of the first cylindrical section, the second cylindrical section and the third cylindrical section is sequentially reduced from bottom to top, two sections of reducing holes are formed corresponding to the bottom hole, when the rubber cushion block is installed in the bottom hole, the step surface of the first cylindrical section is tightly attached to and abutted against the bottom end of the pressure switch body, and the step surface of the second cylindrical section is tightly attached to and abutted against the step in the bottom hole.

Particularly, a plurality of protruding portions are arranged on the surface of one end, close to the first cylindrical section, of the second cylindrical section, and the rubber cushion blocks cannot fall from the bottom holes through the protruding portions.

In particular, the through hole is opened at the center of the rubber cushion block.

Particularly, the bottom end of the first cylindrical section is provided with a cross arc-shaped groove.

Particularly, a pressure switch membrane is arranged in the pressure switch body, and the contact and the separation between the action contact piece and the static contact piece are controlled through the positive and negative bounce of the pressure switch membrane.

Compared with the prior art, the antifreezing pressure switch for the urea pump has the advantages that when the metering pump works normally, the rubber cushion block has no influence on the performance of the metering pump basically; when the metering pump does not work in a low-temperature environment (minus 11 ℃), the acting force generated by freezing and expanding of liquid in the hydraulic cavity of the pump body and the cavity below the pressure switch diaphragm is absorbed through the compression deformation of the rubber cushion block, so that the permanent deformation caused by the stress of the diaphragm and the baffle in the pressure switch is avoided, and the functionality of the pressure switch is effectively ensured. Not only the structure is simple, but also the design is ingenious; and the cost is low, and the safe and stable operation of the urea pump at low temperature is ensured.

Drawings

FIG. 1 is a schematic perspective view of an antifreeze pressure switch for a urea pump according to an embodiment of the present invention;

FIG. 2 is a cross-sectional view of an antifreeze type pressure switch for a urea pump according to an embodiment of the present invention in a normal state;

FIG. 3 is a cross-sectional view of an embodiment of the present invention providing a failure condition of an antifreeze type pressure switch for a urea pump;

fig. 4 is an assembly diagram of an anti-freeze pressure switch 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.

Referring to fig. 1 to 4, in the present embodiment, an anti-freezing pressure switch for a urea pump includes a pressure switch body 1, a stainless steel diaphragm 2 is disposed in the pressure switch body 1, the contact and separation between an active contact and a static contact are controlled by the positive and negative bounce of the pressure switch diaphragm 2, a bottom hole 3 is disposed at the bottom of the pressure switch body 1, and a rubber pad 4 is disposed in the bottom hole 3.

The rubber cushion block 4 adopts a three-section reducing form to form a double-step structure and comprises a first cylindrical section 5, a second cylindrical section 6 and a third cylindrical section 7, the radius of the first cylindrical section 5, the second cylindrical section 6 and the third cylindrical section 7 are sequentially reduced from bottom to top, the corresponding bottom hole 3 is a two-section reducing hole, when the rubber cushion block 4 is arranged in the bottom hole 3, the step surface of the first cylindrical section 5 is tightly attached to and abutted against the bottom end of the pressure switch body 1, namely the rubber cushion block extends out of the bottom hole 3, the step surface of the second cylindrical section 6 is tightly attached to and abutted against the step 8 in the bottom hole 3, and the double-step structure blocks the transmission of the axial stress to the; on the other hand, the rubber cushion block 5 is prevented from moving towards the inner part of the bottom hole 3 under the stress and extruding the stainless steel diaphragm 2, so that the pressure switch is opened abnormally. The bottom of the first cylindrical section 5 of the rubber cushion block 5 is provided with a cross arc-shaped groove 8, so that the pressure bearing area is increased and the liquid circulation is realized.

Center hole 9 has been seted up in the center department of rubber cushion 4, the one end surface that is close to first cylinder section 5 on the second cylinder section 6 is provided with a plurality of bellying 10, make rubber cushion 4 can not drop from bottom hole 3 through bellying 10, when pressure switch and the measuring pump body 11 assembly, install O shape sealing washer 12 in the pressure switch sealing washer inslot earlier, then fill in rubber cushion 4 in pressure switch's bottom hole 3, center hole 9 is linked together the hydraulic pressure chamber of the measuring pump body 11 and the cavity of stainless steel diaphragm 2 below in the pressure switch body 1, it can on the urea pump body 7 to install type pressure switch prevents frostbite at last. When the metering pump works normally, the rubber cushion block 4 basically has no influence on the performance of the metering pump; when the metering pump does not work in a low-temperature environment (minus 11 ℃), acting force generated by freezing and expanding liquid in a hydraulic cavity of a pump body 11 of the metering pump and a lower cavity of the stainless steel diaphragm 2 is absorbed through compression deformation of the rubber cushion block 4, and permanent deformation caused by stress on the stainless steel diaphragm 2 and the baffle 13 is avoided, so that the functionality of the pressure switch is effectively ensured.

The above embodiments have been merely illustrative of the basic principles and features of the present invention, and the present invention is not limited by the above embodiments, and does not depart from the spirit and scope of the present invention. The scope of the invention is defined by the appended claims and equivalents thereof.

Claims

1. The utility model provides a type pressure switch prevents frostbite for urea pump, its includes the pressure switch body, its characterized in that, the bottom of pressure switch body is provided with the bottom hole, the rubber cushion is installed to the bottom hole fit in, the through-hole has been seted up on the rubber cushion, the pressure switch body embeds there is the pressure switch diaphragm, through the contact and the separation between positive and negative spring control action contact and the static contact of pressure switch diaphragm.

2. The antifreeze type pressure switch for the urea pump as set forth in claim 1, wherein said rubber pad has a three-stage reducing form to form a double-step structure including a first cylindrical section, a second cylindrical section and a third cylindrical section having a radius decreasing from bottom to top in sequence, and two reducing holes corresponding to said bottom hole, wherein when said rubber pad is mounted in said bottom hole, a step surface of said first cylindrical section is closely attached to and abutted against a bottom end of said pressure switch body, and a step surface of said second cylindrical section is closely attached to and abutted against a step in said bottom hole.

3. The antifreeze type pressure switch for a urea pump as set forth in claim 2, wherein said second cylindrical section has a plurality of protrusions formed on an end surface thereof adjacent to said first cylindrical section.

4. The antifreeze type pressure switch for a urea pump as set forth in claim 2, wherein said first cylindrical section has a cross-shaped arc-shaped groove formed at a bottom end thereof.

5. The antifreeze type pressure switch for a urea pump as set forth in claim 1, wherein said through hole is opened at a center of said rubber pad.