Connecting and sealing structure for urea pump shell and pipe joint

Abstract

The utility model discloses a connection sealing structure of a urea pump shell and a pipe joint, which comprises the urea pump shell and the pipe joint, an internal thread is arranged on the urea pump shell, an external thread is arranged on the pipe joint, and the pipe joint is arranged on the urea pump shell through the matching of the internal thread and the external thread. The face, making contact with the urea pump shell, of the pipe connector is sealed through a sealing structure. The urea pump shell and the pipe joint are connected through the thread structure, sealing between the urea pump shell and the pipe joint is achieved by matching with the sealing steel ball, and the sealing structure is arranged in the shell, so that liquid does not exist at the installation position of the pipe joint and the shell, the good sealing effect is achieved, and urea leakage is avoided.

Description

Technical Field

[0001] The utility model belongs to the technical field of sealing structures of urea pumps, and in particular relates to a connection sealing structure of a urea pump housing and a pipe joint. Background Art

[0002] The statements herein merely provide background art related to the present invention and do not necessarily constitute prior art.

[0003] The nitrogen oxides (NOx) in diesel exhaust cause serious pollution to the atmospheric environment. At present, diesel exhaust is mainly treated through the selective catalytic reduction system (SCR). The urea pump extracts the automotive urea solution from the urea tank and sprays it into the exhaust pipe as a reducing agent through the nozzle after atomization. The nitrogen oxides (NOx) in the exhaust gas generate harmless nitrogen (N2) and water (H2O) under the action of the catalyst. The urea pump is the core component of the SCR urea injection system. The urea pump can deliver urea to the urea nozzle under a certain pressure, accurately execute the required injection amount, and ensure that the emission meets the regulatory requirements.

[0004] At present, the urea pump housing is made of plastic material to reduce weight. Since the pipe joint needs to be connected to the urea pipe, if there is external stress, it is easy to cause the joint to break. It is expected to use a metal joint, but if the plastic and metal are hard connected, the expansion coefficients are different, and there will be a risk of leakage. In order to reduce the dead weight of the urea pump housing, there is also a method in the prior art that the urea pump housing is made of plastic material and the pipe joint is also made of plastic joint. However, since the pipe joint is less stressed in this method, the failure rate of the pipe joint breaking is high. In addition, the above two connection methods will cause liquid to exist at the installation point of the urea pump and the pipe joint, and there is a risk of leakage. Utility Model Content

[0005] The utility model aims to provide a connection sealing structure between a urea pump housing and a pipe joint, which can avoid the risk of the pipe joint breaking due to external force while ensuring the sealing.

[0006] In order to achieve the above purpose, the utility model is implemented through the following technical solutions:

[0007] In a first aspect, an embodiment of the utility model provides a connection sealing structure of a urea pump housing and a pipe joint, comprising a urea pump housing and a pipe joint, wherein an internal thread is arranged on the urea pump housing, and an external thread is arranged on the pipe joint, and the pipe joint is installed on the urea pump housing by matching the internal thread and the external thread, and the surface where the pipe joint contacts the urea pump housing is sealed by a sealing structure.

[0008] As a further technical solution, the pipe joint includes a sealing portion, a threaded portion, a positioning portion and a urea pipe mounting portion which are connected in sequence.

[0009] As a further technical solution, a plurality of spherical sealing grooves are provided on the sealing portion, a sealing steel ball is installed in each spherical sealing groove, and adjacent sealing steel balls are tightly fitted.

[0010] As a further technical solution, the threaded portion is provided with an external thread, and the diameter of the threaded portion is larger than the diameter of the sealing portion and smaller than the diameter of the positioning portion.

[0011] As a further technical solution, a positioning ring is provided on the urea pipe mounting portion, and the positioning ring is an annular protrusion, and the urea pipe is mounted through the positioning ring.

[0012] As a further technical solution, when the pipe joint is made of metal, a metal insert is arranged in the housing of the urea pump, an internal thread is arranged on the metal insert, and the pipe joint is installed on the metal insert through the thread.

[0013] As a further technical solution, an annular step is provided in the housing of the urea pump, and the metal insert is installed on the annular step.

[0014] As a further technical solution, the urea pump housing and the metal insert are installed by interference fit.

[0015] As a further technical solution, when the pipe joint is made of plastic material, the internal thread on the urea pump housing and the urea pump housing are directly injection-molded to form an integrated structure.

[0016] As a further technical solution, a urea channel runs through the center of the pipe joint, and the urea channel is connected to the inside of the urea pump housing.

[0017] The beneficial effects of the above-mentioned embodiments of the utility model are as follows:

[0018] The connection sealing structure of the urea pump housing and the pipe joint provided by the utility model connects the urea pump housing and the pipe joint by adopting a threaded structure, and at the same time cooperates with a sealing steel ball to realize the sealing between the urea pump housing and the pipe joint. The sealing structure is inside the housing, so there is no liquid at the installation position of the pipe joint and the housing, thereby achieving a good sealing effect and avoiding leakage of urea.

[0019] For the pipe joint made of metal material, the utility model realizes the connection between the urea pump housing and the pipe joint by means of the provided metal insert. For the pipe joint made of plastic material, the utility model uses the internal thread which is an integral structure with the urea pump housing by injection molding to connect with the pipe joint, thereby realizing the same expansion coefficient at the connection position and avoiding urea leakage.

[0020] The utility model provides a connection sealing structure for a urea pump housing and a pipe joint, wherein an internal thread is arranged on the urea pump housing, so that most of the structure of the urea pipe joint is located inside the urea pump housing, thereby avoiding the breakage of the pipe joint due to a large external force on the pipe joint and prolonging the service life of the pipe joint. BRIEF DESCRIPTION OF THE DRAWINGS

[0021] The drawings in the specification, which constitute a part of the present invention, are used to provide a further understanding of the present invention. The illustrative embodiments of the present invention and their descriptions are used to explain the present invention and do not constitute an improper limitation on the present invention.

[0022] Figure 1 It is a schematic diagram of the connection sealing structure of the first urea pump housing and the pipe joint of the utility model;

[0023] Figure 2 It is a schematic diagram of the connection sealing structure of the second urea pump housing and the pipe joint of the utility model.

[0024] The schematic diagram is for illustrative purposes only;

[0025] Among them, 1. urea pump housing; 101. internal thread; 2. pipe joint; 201. sealing part; 2011. sealing groove; 2012; sealing steel ball; 202. threaded part; 2021. external thread; 203. positioning part; 204. urea pipe installation part; 2041. positioning ring; 205. urea channel; 3. metal insert; 301. internal thread of metal insert. DETAILED DESCRIPTION

[0026] It should be noted that the following detailed descriptions are exemplary and are intended to provide further explanation of the present invention. Unless otherwise specified, all technical and scientific terms used in the present invention have the same meanings as those commonly understood by those skilled in the art to which the present invention belongs.

[0027] Example 1

[0028] In a typical implementation of the present invention, Figure 1 and Figure 2 As shown, a connection sealing structure of a urea pump housing and a pipe joint is provided. An internal thread 101 is provided on the urea pump housing 1, and an external thread 2021 is provided on the pipe joint 2. The pipe joint 2 is installed on the urea pump housing 1 through the cooperation of the internal thread 101 and the external thread 2021. The contact surface of the pipe joint 2 and the urea pump housing 1 is sealed by a sealing steel ball 2012.

[0029] Specifically, the pipe joint 2 includes a sealing portion 201, a threaded portion 202, a positioning portion 203 and a urea pipe mounting portion 204 connected in sequence, and a plurality of spherical sealing grooves 2011 are provided on the sealing portion 201, and a sealing steel ball 2012 is installed in each spherical sealing groove 2011, and the adjacent sealing steel balls 2012 are tightly fitted, and the gap between the contact surface of the pipe joint 2 and the urea pump housing 1 is sealed by the plurality of sealing steel balls cooperating with the wall surface of the sealing groove. Under normal working conditions, the steel ball is pressed on the sealing surface to form a sealing line to prevent medium leakage, so that there is no liquid at the installation point of the pipe joint 2 and the urea pump housing 1. Compared with the existing use of rubber sealing rings, urea leakage caused by hardening, deformation and surface cracking of the rubber sealing ring can be avoided. The spherical sealing structure provided in this embodiment can also be replaced with other existing sealing structures according to actual application needs, such as metal sealing rings, labyrinth sealing rings, etc., as long as the sealing effect can be achieved.

[0030] Furthermore, an external thread 2021 is provided on the threaded portion 202, and the diameter of the threaded portion 202 is larger than the diameter of the sealing portion 201 and smaller than the diameter of the positioning portion 203. Therefore, the sealing portion 201, the threaded portion 202 and the positioning portion 203 are stepped, and the mounting hole on the urea pump housing 1 is also stepped. The installation of the pipe joint is achieved through the cooperation between the two. This structure is easy to install, and the positioning portion 203 provided can play a role in limiting and positioning, which can avoid the thread slippage phenomenon caused by excessive rotation between the internal thread and the external thread.

[0031] Furthermore, a positioning ring 2041 is provided on the urea pipe mounting portion 204. The positioning ring 2041 is a ring-mounted protrusion. The urea pipe is installed through the positioning ring 2041. The positioning ring 2041 is conducive to enhancing the stability of the connection between the urea pipe and the pipe joint, and the urea pipe is not easy to fall off. A urea channel 205 runs through the center of the pipe joint. The urea channel 205 is connected to the urea pump housing 1 to realize the pumping of urea to the urea pipe through the urea pump.

[0032] When the pipe joint is made of metal, Figure 1 As shown, a metal insert 3 is provided in the urea pump housing 1, and a metal insert internal thread 301 is provided on the metal insert 3, and the pipe joint 2 is installed on the metal insert 3 through a thread. Specifically, an annular step is provided in the urea pump housing, and the metal insert 3 is installed on the annular step. In this embodiment, the urea pump housing 1 and the metal insert 3 are installed with an interference fit to prevent the metal insert from rotating when the pipe joint is installed. The urea pump housing 1 and the metal insert 3 can also be bonded with a strong glue.

[0033] When the pipe joint is made of plastic material, Figure 2As shown, the internal thread 101 on the urea pump housing 1 is directly injection-molded into an integral structure with the urea pump housing.

[0034] The connection sealing structure of the urea pump housing and the pipe joint provided in this embodiment connects the urea pump housing and the pipe joint by adopting a threaded structure, and at the same time, a sealing steel ball is used to achieve the sealing between the urea pump housing and the pipe joint. The sealing structure is inside the housing. Therefore, there is no liquid at the installation point of the pipe joint and the housing, thereby avoiding leakage of urea.

[0035] The above description is only the preferred embodiment of the utility model, and is not intended to limit the utility model. For those skilled in the art, the utility model can have various modifications and changes. Any modification, equivalent replacement, improvement, etc. made within the spirit and principle of the utility model shall be included in the protection scope of the utility model.

Claims

1. A connection sealing structure between a urea pump housing and a pipe joint, characterized in that: The invention comprises a urea pump housing (1) and a pipe joint (2), wherein the urea pump housing (1) is provided with an internal thread (101), and the pipe joint (2) is provided with an external thread (2021); the pipe joint (2) is mounted on the urea pump housing (1) by means of the cooperation between the internal thread (101) and the external thread (2021); and the contact surface between the pipe joint (2) and the urea pump housing (1) is sealed by means of a sealing structure.

2. The connection sealing structure of the urea pump housing and the pipe joint according to claim 1, characterized in that: The pipe joint (2) comprises a sealing portion (201), a threaded portion (202), a positioning portion (203) and a urea pipe mounting portion (204) which are connected in sequence.

3. The connection sealing structure of the urea pump housing and the pipe joint according to claim 2, characterized in that: The sealing portion (201) is provided with a plurality of spherical sealing grooves (2011), a sealing steel bead (2012) is installed in each spherical sealing groove (2011), and adjacent sealing steel beads (2012) are tightly fitted.

4. The connection sealing structure of the urea pump housing and the pipe joint according to claim 2, characterized in that: The threaded portion (202) is provided with an external thread (2021), and the diameter of the threaded portion (202) is greater than the diameter of the sealing portion (201) and smaller than the diameter of the positioning portion (203).

5. The connection sealing structure of the urea pump housing and the pipe joint according to claim 2, characterized in that: The urea pipe installation portion (204) is provided with a positioning ring (2041), and the positioning ring (2041) is an annular protrusion, and the urea pipe is installed through the positioning ring (2041).

6. The connection sealing structure of the urea pump housing and the pipe joint according to claim 1, characterized in that: When the pipe joint (2) is made of metal material, a metal insert (3) is arranged in the urea pump housing (1), a metal insert internal thread (301) is arranged on the metal insert (3), and the pipe joint (2) is mounted on the metal insert (3) via threads.

7. The connection sealing structure of the urea pump housing and the pipe joint according to claim 6, characterized in that: An annular step is provided in the urea pump housing (1), and the metal insert (3) is mounted on the annular step.

8. The connection sealing structure of the urea pump housing and the pipe joint according to claim 7, characterized in that: The urea pump housing (1) and the metal insert (3) are installed in an interference fit.

9. The connection sealing structure of the urea pump housing and the pipe joint according to claim 1, characterized in that: When the pipe joint (2) is made of plastic material, the internal thread on the urea pump housing (1) and the urea pump housing (1) are directly injection-molded to form an integrated structure.

10. The connection sealing structure of the urea pump housing and the pipe joint according to claim 1, characterized in that: A urea channel (205) runs through the center of the pipe joint (2), and the urea channel (205) is connected to the inside of the urea pump housing (1).

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