CN104879197B - A kind of exhaust pipe erecting device of injector - Google Patents

Abstract

The invention discloses an exhaust pipe installation device for an injector, which includes an injector, a radiator, an exhaust pipe installation flange, etc., the radiator is connected to the exhaust pipe installation flange through a transition bracket, and the top of the transition bracket The annular flange with the throat is at least indirectly connected to the end face flange of the radiator in a force-transmitting manner, and the middle part of the bottom end of the transition card seat has a tapered boss protruding below the exhaust pipe mounting flange surface, and through a metal spacer. The heat washer is in press contact with the exhaust pipe mounting flange, and the tapered boss and the sealing boss form an inverted stepped structure at the bottom of the transition seat. The invention forms a plurality of heat-insulating air cavities through a special-structure transition deck, radiator, heat-insulating pad and metal heat-insulating gasket, which can effectively block and reduce the heat exchange between the high-temperature exhaust of the engine or the wall of the exhaust pipe to the injector, Ensure that the injector is within the normal operating temperature range, with high structural strength, simple and reliable, and the injection position can be adjusted according to needs, and the installation is flexible.

Description

Exhaust pipe installation device for injector

technical field

The invention relates to an injector exhaust pipe installation device, which is suitable for directly installing an electromagnetically driven injector on an engine exhaust pipe to ensure that the injector will not be overheated due to the high temperature of the exhaust gas. This field belongs to the technical field of automobile exhaust emission control.

Background technique

With the increasingly serious environmental problems and energy crisis, emission regulations are becoming stricter, and more and more energy-saving and emission-reduction technologies are applied to vehicles, among which SCR (Selective Catalytic Reduction) technology is a technology to reduce nitrogen oxide emissions . The SCR technology is to inject the reducing agent into the exhaust flow of the engine, and then the reducing agent reacts with the nitrogen oxides in the exhaust gas in the SCR catalytic converter to form nitrogen and water, so as to achieve the purpose of purification. However, the injector used to inject the reducing agent will be affected by the high temperature exhaust gas, which will cause the injector to overheat, the electromagnetic valve temperature will be too high to fail, and even cause serious failure of the injector to burn.

At present, in order to prevent the temperature of the injector from being too high, in order to ensure that the temperature of the injector is within the normal range, most of the products on the market use cooling water to cool the injector or use compressed air for forced cooling, for example: Patent The cooling method described in CN200410004472.0 mainly uses cooling water to cool the injector, and when the compressed air is turned on independently without spraying, the injector is also forced to cool. The cooling methods described in patents CN10220984A, WO2012107484 (A1), CN201010100199.7, and CN201010275693.7 are mainly to set up a cooling chamber and cool the injector with cooling water. The cooling method described in the patent CN201010541488.0 mainly uses cooling water and a special-shaped heat shield to cool the injector.

The method of using cooling water to cool the injector requires additional cooling pipelines, and the cooling heat dissipation device also needs to process cooling channels, which increases the complexity of the system and the manufacturing cost. Products that use compressed air to cool the injector require a large amount of compressed air, which brings certain safety hazards to the brake system or requires an additional air pump, and the addition of an air pump increases the complexity and cost of the system.

However, there are also a small number of products on the market that use natural air cooling to cool the injector, such as the method described in patent CN200780006778.1, which mainly uses a special heat insulation and heat dissipation structure to cool the injector. The main special structure is a sleeve piece with an elongated and thin-walled connecting part, which is a metal formed part with a Z-shaped or C-shaped cross-section. The sleeve part with the elongated and thin-walled connection part mainly reduces the heat conducted by the high-temperature exhaust gas to the injector from the following two aspects: first, the heat must flow through the sleeve part, and the elongated The sleeve part of the thin-walled connection part forms a kind of "thermal throttle valve", which hinders the conduction of heat; the second is that the sleeve part with the elongated thin-walled connection part increases the contact area with the air, increasing the cooling effect.

This structure can reduce the heat transferred to the injector by high-temperature exhaust gas, but this kind of slender, thin-walled sleeve has poor adaptability to engine exhaust vibration due to its low structural strength, which affects the service life of the injection device. Moreover, the press-fitted integrated structure prevents the injection position from being flexibly adjusted according to actual needs.

Contents of the invention

The purpose of the present invention is to provide an ejector exhaust pipe installation device for the existing cooling mode of the ejector cooling and heat dissipation device, which not only ensures the temperature of the ejector within the normal range, but also has a high and simple structural strength of the entire cooling and heat dissipation device. Reliable, and it makes the installation position of the injector flexible.

This object is achieved by the injector cooling and heat dissipation and installation device of the present invention. Important features of the invention are further described below and illustrated in the accompanying drawings.

The injector installed on the exhaust pipe is not only heated when its head is in direct contact with the high-temperature exhaust gas, but also heated by heat conduction from other structures. The invention can effectively block and reduce the heat exchange between the high-temperature exhaust of the engine or the exhaust pipe to the injector by arranging the special structure of the transition card seat, the radiator, the heat insulation pad and the multiple heat insulation air cavities, ensuring the injection The temperature of the device is within the normal range.

An exhaust pipe installation device for an injector, including an injector, a radiator, an exhaust pipe installation flange, etc., the radiator is installed with an injector inside, and the radiator is installed through a transition bracket and an exhaust pipe installation method The top end of the transition seat has an annular flange with a throat and the end face flange of the radiator is at least indirectly connected in a force transmission manner, and the bottom end of the transition seat has at least 3 circumferentially symmetrical distributions for The fastening method is the bolt seat connected to the exhaust pipe installation flange. The flange is installed on the sealing boss for pressing contact, and the tapered boss and the sealing boss form an inverted stepped structure downwards at the bottom of the transition holder.

A metal heat insulating washer is arranged between the sealing boss of the transition card seat and the upper end surface of the exhaust pipe installation flange. The setting of the metal heat insulating gasket avoids the direct contact between the exhaust pipe installation flange and the sealing boss, reduces the heat conduction from the exhaust pipe installation flange to the transition card seat, and the transition card seat passes symmetrically in the circumferential direction At least 3 bolt seats are connected to the exhaust pipe mounting flange in a fastened manner. In order to reduce heat conduction, the bolt seat is further provided with a chamfered angle, which not only reduces the contact area between the transition seat and the exhaust pipe mounting flange, but also increases the pre-tightening force of the cooling device installation.

The tapered boss of the transition card seat, the sealing boss and the metal heat insulation gasket form the first heat insulation air cavity, which plays a good heat insulation effect. An insulating pad is provided between the annular flange of the transition card seat and the end face flange, which reduces the heat conducted by the transition card seat to the radiator. At the same time, the outer cylindrical surface of the hollow extending shaft of the radiator is cut into a regular polyhedron, and the circumference is cut into at least one heat-resisting groove. The contact between the hollow protruding shaft and the inner stepped hole of the ring flange is changed from a large-area surface contact to a plurality of small-area strip contacts, which increases the "heat flow resistance" effect and reduces the contact between the transition card seat and the radiator. Heat Conduction.

The heat insulation pad set between the hollow extension shaft of the radiator and the step surface of the stepped hole of the transition holder prevents the high-temperature exhaust gas from flowing in the axial direction along the gap between the injector and the inner hole of the radiator, reducing the high-temperature exhaust gas. Heat transfer to injector.

There is a sealing ring between the neck of the injector and the hollow shaft of the radiator. The setting of the sealing ring further prevents the flow of high-temperature exhaust gas in the axial direction along the gap between the injector and the inner hole of the radiator, and the sealing ring and An insulated air cavity is formed between the inner hole of the radiator, the heat insulating pad, and the injector, which further reduces heat conduction and lowers the temperature of the injector.

Preferably: the heat insulation pad is preferably a high temperature resistant silica airgel heat insulation sheet with extremely low thermal conductivity.

Preferably: the outer cylindrical surface of the hollow protruding shaft is cut into a regular polyhedron, and the regular polyhedron is preferably a regular hexahedron.

The invention forms a plurality of heat-insulating air cavities by arranging a special-structured transition deck, radiator, heat-insulating pad and metal heat-insulating gasket, which can effectively block and reduce the heat exchange between the high-temperature exhaust of the engine or the wall of the exhaust pipe to the injector , to ensure that the injector is within the normal operating temperature range. And you can choose the transition card holder with different central positions according to actual needs, adjust the injection position, and install flexibly. In addition, the cooling and heat dissipation device of the injector has high structural strength, and is simple and reliable.

Description of drawings

Fig. 1 is a schematic front sectional view of the structure of the present invention.

Fig. 2 is a top view of the transition holder in the structure of the present invention.

Fig. 3 is an axonometric view of the transition deck in the structure of the present invention.

Fig. 4 is a structural schematic diagram of the radiator in the structure of the present invention.

Fig. 5 is a structural schematic diagram of the metal heat insulating washer in the structure of the present invention.

Explanation of reference signs:

1- Cooling and heat dissipation installation device; 2- Injector; 3- Radiator; 4- Sealing ring; 5- Insulation pad; 6- Insulation air chamber; 7- Insulation pad; Gasket; 10-insulated air chamber; 11-exhaust; 12-exhaust pipe mounting flange; 13-bolt; 14-clamp; 15-bolt; 16-gasket; 17-pipe joint; 18-bolt; 19-sealing ring; 20-insulation plate.

Detailed ways

Figure 1-3 is a schematic diagram of an implementation structure of the exhaust pipe installation device of the injector. The cooling and heat dissipation installation device 1 includes the injector 2, the radiator 3, the exhaust pipe installation flange 12, etc., and the radiator 3 passes through The transition mount 8 is connected to the exhaust pipe mounting flange 12, and the top end of the transition mount 8 has a throat annular flange 8-4 and the end face flange 3-2 of the radiator 3 at least indirectly in a force transmission manner. The bottom end of the clamped transition seat 8 has at least three bolt seats 8-3 distributed symmetrically in the circumferential direction to connect with the exhaust pipe mounting flange 12 in a fastening manner. The middle part of the bottom end of the transition clamp 8 has an extension The tapered boss 8-1 below the surface of the inlet and exhaust pipe installation flange 12, and the sealing boss 8-2 that is in press contact with the exhaust pipe installation flange 12 through the metal heat insulating gasket 9, the tapered The boss 8-1 and the sealing boss 8-2 form an inverted stepped structure at the bottom of the transition holder 8 downwards.

As shown in Figures 1 and 4, the outer cylindrical surface of the hollow protruding shaft 3-1 of the radiator 3 is cut into a regular polyhedron, and the circumference is circumscribed with at least one heat-resistant groove 3-4. 3 is installed inside the injector 2, and the protruding part of the injector 2 penetrates the inner stepped hole 8-6 of the annular flange 8-4 of the transition holder 8 and the middle hole of the inverted stepped structure at the bottom. The top end of the transition holder 8 is at least indirectly connected to the flange 3-2 on the radiator 3 in a force-transmitting manner through an annular flange 8-4 with a throat, preferably through a clamp 14 Connect by means of force transmission.

The working principle of cooling and heat dissipation of the injector cooling heat dissipation device is described according to the drawings. The heat conducted by the high-temperature exhaust gas to the injector 2 and its related components is mainly divided into three aspects, which are respectively named as the first heat flow, the second heat flow, and the third heat flow.

The first heat flow is mainly the heat conducted by the high-temperature exhaust gas through contact with the head of the injector 2. By making the shell of the injector 2 a thin shell, it has a good "heat flow resistance" effect, so The heating effect of the first heat flow on the injector 2 is small, and part of the heat is absorbed by the reducing agent in the injector 2 .

The second heat flow is the heat conducted to the transition seat 8 through the exhaust pipe mounting flange 12 . The present invention reduces the heat conducted to the transition seat 8 through the following measures, thereby reducing the heat conducted to the injector 2 . An implementation example of specific measures is as follows:

Firstly, a metal heat insulating gasket 9 is provided between the axial end of the sealing boss 8-2 of the transition clamp 8 and the exhaust pipe mounting flange 12, and the three are at least connected in a force-transmitting manner. And the lower end surface of the tapered boss 8-1 of the transition card seat 8 is connected with the metal heat insulating gasket 9 in a force transmission manner, thereby sealing the high-temperature exhaust, and the tapered boss 8-1 of the transition card seat 8 A heat insulating air cavity 10 is formed with the sealing boss 8-2 and the metal heat insulating gasket 9. The setting of the metal heat insulating gasket 9 seals the exhaust gas 12, isolates the contact between the conical boss 8-1 of the transition bracket 8 and the high-temperature exhaust gas 12, and isolates the transition bracket 8 and the exhaust pipe installation flange 12 The direct contact reduces the heat conducted to the transition deck 8 to a certain extent. At the same time, the heat-insulating air cavity 10 further reduces the heat transferred from the high-temperature exhaust gas 12 to the transition card seat 8 .

As shown in Figure 5, the metal heat insulating gasket 9 has an umbrella-shaped portion 9-1 extending radially inward, a bowl-shaped area 9-2 and folds 9-3, and is evenly distributed around the folded area 9-3 At least 2 snaps 9-4. There is a small gap between the free edge of said umbrella portion 9 - 1 and the injector 2 . The wrinkle area 9-3 is provided with at least one wrinkle, which reduces the contact area and attenuates the vibration transmitted by the exhaust pipe mounting flange 12, prolonging the service life of the cooling and heat dissipation device.

Secondly, the bottom end of the transition bracket 8 is fastened to the exhaust pipe mounting flange 12 through at least three bolt seats 8-3 symmetrically distributed in the circumferential direction, and at the same time, the bolt seats 8-3 are provided with chamfered corners outward. 8-5, the contact area between the transition bracket 8 and the upper end surface of the exhaust pipe installation flange 12 is reduced, and the pre-tightening force for the installation of the cooling and heat dissipation device is increased.

Through the above measures, the heat transferred to the transition card seat 8 is reduced, and at the same time, the heat dissipation capacity of the fins 3 - 3 is increased, thereby increasing the heat dissipation of the injector 2 . The specific description is as follows:

First, an insulating pad 7 is provided between the annular flange 8-4 of the transition holder 8 and the end flange 3-2, which avoids the direct contact between the annular flange 8-4 and the end flange 3-2, and reduces the The transition card seat 8 conducts the heat to the radiator 3 .

Second, the outer cylindrical surface of the hollow extending shaft 3-1 of the radiator 3 is cut into a regular polyhedron, and the circumference is circumscribed with at least one heat-resistant groove 3-4, so that the hollow extending shaft 3-1 The contact between the cylinder and the cylindrical surface in the stepped hole 8-6 is changed from a large-area surface contact to a plurality of small-area strip contacts, which increases the "heat flow resistance" effect and reduces the heat conducted to the radiator 3. The regular polyhedron A regular hexahedron is preferred.

Thirdly, an insulating pad 7 is provided between the lower end surface of the hollow extending shaft 3-1 of the radiator 3 and the bottom surface of the stepped hole 8-6 to reduce the heat conducted to the radiator 3 .

Fourth, a heat-insulating air cavity 6 is formed between the inner holes of the sealing ring 4, the heat-insulating pad 7, the injector 2, and the radiator 3, which further reduces heat conduction. At the same time, the sealing ring 4 is arranged between the flange 3-2 section of the inner hole of the radiator 3 and the injector 2, preventing the axial flow of high-temperature exhaust gas in the gap between the injector 2 and the inner hole of the radiator 3 , reducing thermal convection.

Fifth, the radiator 3 is made of metal with high thermal conductivity, especially the fins 3-3.

The lower end surface of the radiator 3 is connected with a heat shield 20 through at least two bolts 15 . When the injector 2 and the cooling and heat dissipation device 1 are installed at a certain angle with the exhaust pipe, the heat shield 20 reduces the radiation heating of the high temperature exhaust pipe to the cooling and heat dissipation device.

The thermal insulation pads 5 and 7 are preferably high-temperature-resistant silica airgel thermal insulation sheets with extremely low thermal conductivity.

The central positions of the annular flange 8-4 of the transition holder 8 coincide with the stepped hole 8-6, and the central position can be changed on the axis A of symmetry. As shown in Figure 3, it is an implementation example in which the center position is on the transition card seat 8. The center positions of the annular flange 8-4 and the stepped hole 8-6 can be selected according to different injection positions. The transition deck 8 makes the installation of the cooling and heat dissipation device of the injector flexible, simple and reliable.

The positioning hole 8-7 provided on the annular flange 8-4 of the transition card seat 8 is equipped with a positioning pin, which can prevent the rotation of the devices above the transition card seat 8.

The upper end surface of the radiator 3 is fixed with a pipe joint 17 by at least two bolts 18 , and a gasket 16 is arranged between the pipe joint 17 and the radiator 3 .

The sealing ring 4 is made of high temperature resistant rubber material.

Claims (9)

1. An injector exhaust pipe installation device (1), including an injector (2), a radiator (3), and an exhaust pipe installation flange (12), and the radiator (3) is equipped with an injector The radiator (2), the radiator (3) is connected to the exhaust pipe installation flange (12) through the transition mount (8), the feature is that the top of the transition mount (8) has a throat ring The flange (8-4) is at least indirectly connected to the end face flange (3-2) of the radiator (3) in a force transmission manner, and the bottom end of the transition holder (8) has at least three circumferentially symmetrically distributed The bolt seat (8-3) connected to the exhaust pipe installation flange (12) in a fastened manner, and the middle part of the bottom end of the transition holder (8) has a The conical boss (8-1), and the sealing boss (8-2) that makes pressure contact with the exhaust pipe mounting flange (12) through the metal heat insulating gasket (9), the conical boss ( 8-1) and the sealing boss (8-2) form an inverted stepped structure downward at the bottom of the transition holder (8); A heat-insulating air chamber (10) is formed between the tapered boss (8-1) of the transition holder (8), the sealing boss (8-2), and the metal heat-insulating gasket (9); There is a sealing ring (4) between the neck of the injector (2) and the hollow extension shaft (3-1) of the radiator (3); the outer cylindrical surface of the hollow extension shaft (3-1) is sealed cut into a regular polyhedron, and the circumference is circumscribed with at least one heat-resisting groove (3-4); the transition holder (8) has a stepped hole (8-6), and the hollow of the heat sink (3) An insulating pad (7) is provided between the lower end surface of the extension shaft (3-1) and the stepped surface of the stepped hole (8-6); the hollow extension shaft (3-1) of the radiator (3) is connected to the A heat insulating air cavity (6) is formed between the sealing ring (4), the heat insulating pad (7) and the neck of the injector (2). 2. The injector exhaust pipe installation device according to claim 1, characterized in that: the center position of the annular flange (8-4) and the stepped hole (8-6) of the transition holder (8) Coincident, and its center position can be adjusted on the symmetry plane perpendicular to the top of the transition deck (8). 3. The exhaust pipe installation device of the injector according to claim 1, characterized in that: the annular flange (8-4) of the transition holder (8) and the end flange of the radiator (3) ( 3-2) A thermal insulation pad (5) is arranged between the axial ends. 4. The injector exhaust pipe installation device according to claim 1, characterized in that: the protruding part of the injector (2) penetrates the annular flange (8-4) of the transition bracket (8) ) of the inner stepped hole (8-6) and the middle hole of the inverted stepped structure at the bottom. 5. The injector exhaust pipe installation device according to any one of claims 1-4, characterized in that: the metal heat insulating gasket (9) has an umbrella-shaped portion (9- 1), a bowl-shaped area (9-2) and folds (9-3), and at least 2 buckles (9-4) are evenly distributed around the fold area (9-3). 6. The injector exhaust pipe installation device according to claim 5, characterized in that: there is a gap between the free edge of the umbrella part (9-1) and the injector (2); The wrinkled area (9-3) is provided with at least 1 wrinkle. 7. The installation device for the exhaust pipe of the injector according to claim 1, characterized in that: the annular flange (8-4) of the transition holder (8) is provided with a positioning hole (8-7). 8. The installation device for the exhaust pipe of the injector according to claim 1, characterized in that: the fins (3-3) on the radiator (3) are made of metal with high thermal conductivity; The radiator (3) and the heat shield (20) are connected by at least 2 bolts (15); the upper end of the radiator (3) is fixed with a pipe joint (17) by at least 2 bolts (18). 9. The installation device for the exhaust pipe of the injector according to claim 1, characterized in that: the sealing ring (4) is made of high temperature resistant rubber material.