EGR pipe for large-displacement diesel engine

Abstract

The utility model provides an EGR (Exhaust Gas Recirculation) pipe for a large-displacement diesel engine, which comprises a delivery pipe, and an inlet joint and an outlet joint arranged at two ends of the delivery pipe, the conveying pipe comprises a first pipe section connected with the inlet connector, a second pipe section connected with the outlet connector, a first corrugated pipe with one end connected with the first pipe section, a second corrugated pipe with one end connected with the second pipe section, and a third pipe section connected between the first corrugated pipe and the second corrugated pipe. The outer side of the first pipe section and the outer side of the second pipe section are each coated with a composite heat preservation layer, and the outer side of the first corrugated pipe and the outer side of the second corrugated pipe are each coated with a flexible heat preservation layer. According to the EGR pipe for the large-displacement diesel engine, the steel wire woven layer wraps the outer side of the second heat preservation cotton, the steel wire woven layer protects the second heat preservation cotton, meanwhile, the deformation adaptability to the first corrugated pipe and the second corrugated pipe is high, the outer side of the first pipe section and the outer side of the second pipe section are both wrapped with the composite heat preservation layers, and therefore the heat preservation effect is good. And by arranging the segmented heat preservation layer structure of the composite heat preservation layer and the flexible heat preservation layer, the heat preservation effect of the EGR pipe is good, and durability is higher.

Description

TECHNICAL FIELD

[0001] The utility model relates to the technical field of automobile engine, concretely relates to EGR pipe for large displacement diesel engine. BACKGROUND

[0002] EGR pipe is the key pipeline connecting EGR cooler, EGR valve and engine body in EGR system, responsible for transporting part of exhaust gas from exhaust manifold to intake manifold to realize exhaust gas recirculation. EGR pipe needs to meet the requirements of high temperature adaptability (need to resist high temperature exhaust gas discharged by engine), reliability (need to withstand corrosive components in exhaust gas for a long time) and the like, and the structural reliability of EGR system pipeline of large displacement diesel engine, as a core component of controlling nitrogen oxide emission, is facing severe challenges in high temperature exhaust gas and severe vibration working conditions.

[0003] However, the traditional EGR pipe adopts the structural design of single-layer corrugated pipe matched with rigid heat preservation sleeve, the corrugated pipe can compensate thermal expansion, but under the engine full working condition vibration spectrum, the rigid heat preservation layer outside the corrugated pipe is easy to cause structure cracking due to frequent deformation, the existing EGR pipe is not strong in durability, and it is difficult to meet the needs of large displacement diesel engine, and the present scheme solves the technical problem. UTILITY MODEL CONTENT

[0004] In view of the defects in the prior art, the utility model provides an EGR pipe for large displacement diesel engine, the flexible heat preservation layer includes heat preservation cotton two in contact with the corrugated pipe, the steel wire woven layer outside the heat preservation cotton two is covered, the heat preservation cotton two is protected through the steel wire woven layer, and the deformation adaptability of the corruggated pipe one and the corrugated pipe two is relatively strong, the outer side of the pipe section one and the pipe section two is covered with the composite heat preservation layer, on the one hand, the heat preservation effect of the pipe section one and the pipe section two is good, on the other hand, the aluminum foil protection layer is not easy to deform, through the segmented heat preservation layer structure of the composite heat preservation layer and the flexible heat preservation layer, the heat preservation effect of the EGR pipe is good, and the durability is stronger.

[0005] To achieve the above object, the technical scheme adopted by the utility model is as follows: an EGR pipe for large displacement diesel engine, comprising a conveying pipe, an inlet joint and an outlet joint arranged at both ends of the conveying pipe, the conveying pipe comprising a pipe section one connected with the inlet joint, a pipe section two connected with the outlet joint, a corrugated pipe one connected with the pipe section one at one end, a corrugated pipe two connected with the pipe section two at one end, and a pipe section three connected and arranged between the corrugated pipe one and the corrugated pipe two.

[0006] The outer side of the pipe section one and the pipe section two is covered with a composite heat preservation layer, and the outer side of the corrugated pipe one and the corrugated pipe two is covered with a flexible heat preservation layer.

[0007] The flexible heat preservation layer comprises a steel wire braiding layer and a heat preservation cotton two arranged in sequence from outside to inside, and the heat preservation cotton two is in contact with the outside of the corrugated pipe one and the corrugated pipe two.

[0008] The composite heat preservation layer comprises a heat preservation cotton one and an aluminum foil protection layer arranged in sequence from inside to outside.

[0009] The side of the pipe segment one and the pipe segment two is provided with a limiting groove, the outside of the composite heat preservation layer is sleeved with a hoop, and the hoop is pressed in the limiting groove.

[0010] The pipe segment one is provided with a flange plate one close to one end of the corrugated pipe one, the pipe segment two is provided with flange plates two at two ends, the flexible heat preservation layer is provided with flange plates three at two ends, and the flexible heat preservation layer is connected with the pipe segment one and the pipe segment two through the flange plates three respectively.

[0011] Compared with the prior art, the utility model has the advantages that:

[0012] (1) the flexible heat preservation layer comprises the heat preservation cotton two in contact with the corrugated pipe, the steel wire braiding layer covering the outside of the heat preservation cotton two, the steel wire braiding layer protects the heat preservation cotton two and has strong deformation adaptability to the corrugated pipe one and the corrugated pipe two, the outside of the pipe segment one and the pipe segment two is covered with the composite heat preservation layer, the heat preservation effect of the pipe segment one and the pipe segment two is good on the one hand, and the aluminum foil protection layer is not easy to deform on the other hand, the sectional heat preservation layer structure of the composite heat preservation layer and the flexible heat preservation layer is provided, the heat preservation effect of the EGR pipe is good, and the durability is stronger.

[0013] (2) the composite heat preservation layer is fixed in the limiting groove through the hoop, the replacement of the composite heat preservation layer is realized through the dismounting of the hoop, the replacement of the heat preservation layer is convenient and fast, the steel wire braiding layer in the flexible heat preservation layer is connected with the flange plate two of the pipe segment three through the flange plate three, the fixing of the steel wire braiding layer is more firm and reliable, the deformation adaptability to the corrugated pipe one and the corrugated pipe two is stronger, and the durability of the EGR pipe is improved.

[0014] (3) the EGR pipe is connected to the EGR system, when the EGR pipe is impacted by internal pressure, the impact is buffered through the deformation of the corrugated pipe one and the corrugated pipe two, the pipe wall breakage caused by the excessive internal pressure of the EGR pipe is avoided, when the EGR pipe is vibrated, the stress concentration of the inlet joint and the outlet joint caused by the vibration of the diesel engine is avoided through the buffering of the corrugated pipe one and the corrugated pipe two, the service life and the connection reliability of the EGR pipe are improved through the design of the multi-section corrugated pipe. BRIEF DESCRIPTION OF DRAWINGS

[0015] Figure 1 It is the external structure schematic view of the utility model;

[0016] Figure 2This is a schematic diagram of the internal structure of this utility model;

[0017] Figure 3 This is a structural schematic diagram of pipe section two of this utility model;

[0018] Figure 4 This is a schematic diagram of the composite protective layer and flexible insulation layer of this utility model;

[0019] Figure 5 This is a schematic diagram of the combined structure of flange plate two and flange plate three of this utility model.

[0020] In the diagram: 1. Conveying pipe; 11. Pipe section one; 12. Pipe section two; 13. Corrugated pipe one; 14. Corrugated pipe two; 15. Pipe section three; 2. Inlet joint; 3. Outlet joint; 4. Composite insulation layer; 41. Insulation cotton one; 42. Aluminum foil protective layer; 5. Flexible insulation layer; 51. Steel wire braided layer; 52. Insulation cotton two; 6. Limiting groove; 7. Clamp; 8. Flange plate one; 9. Flange plate two; 10. Flange plate three. Detailed Implementation

[0021] To more clearly illustrate the technical features of this solution, the following detailed implementation method will be used to explain the solution.

[0022] See Figures 1-5 EGR pipe for large displacement diesel engines includes a delivery pipe 1, an inlet connector 2 and an outlet connector 3 at both ends of the delivery pipe 1. The delivery pipe 1 includes a pipe section 11 connected to the inlet connector 2, a pipe section 2 12 connected to the outlet connector 3, a corrugated pipe 13 connected at one end to the pipe section 11, a corrugated pipe 2 14 connected at one end to the pipe section 2 12, and a pipe section 3 15 connecting the corrugated pipe 13 and the corrugated pipe 2 14.

[0023] Both pipe section 11 and pipe section 2 are covered with a composite insulation layer 4 on the outside, and corrugated pipe 13 and corrugated pipe 24 are covered with a flexible insulation layer 5 on the outside.

[0024] The flexible insulation layer 5 includes a steel wire braided layer 51 and an insulation cotton 52 arranged sequentially from the outside to the inside. The insulation cotton 52 is in contact with the outer side of the corrugated pipe 13 and the corrugated pipe 14.

[0025] The composite insulation layer 4 includes insulation cotton 41 and aluminum foil protective layer 42 arranged sequentially from the inside out.

[0026] Limiting grooves 6 are provided on the sides of pipe section 11 and pipe section 22, and clamps 7 are fitted on the outside of the composite insulation layer 4, which are pressed into the limiting grooves 6.

[0027] Flange plate 8 is provided at one end of pipe section 11 near corrugated pipe 13, flange plate 9 is provided at both ends of pipe section 2, and flange plate 30 is provided at both ends of flexible insulation layer 5. Flexible insulation layer 5 is connected to pipe section 11 and pipe section 2 12 respectively through flange plate 310.

[0028] The specific working process of this utility model:

[0029] When the EGR pipe is connected to the EGR system, the deformation of the corrugated pipe 13 and corrugated pipe 2 14 buffers the impact when the EGR pipe is subjected to internal pressure, thus avoiding pipe wall damage caused by excessive internal pressure. When the EGR pipe is subjected to vibration, the corrugated pipe 13 and corrugated pipe 2 14 buffer the stress concentration between the delivery pipe 1 and the inlet connector 2 and outlet connector 3 when the diesel engine vibrates. The multi-section corrugated pipe design improves the service life and connection reliability of the EGR pipe.

[0030] The outer sides of corrugated pipe 13 and corrugated pipe 2 14 are covered with a flexible insulation layer 5. The flexible insulation layer 5 includes insulation cotton 2 52 in contact with the corrugated pipe and a steel wire braided layer covering the outside of the insulation cotton 2 52. The steel wire braided layer protects the insulation cotton 2 52 while providing strong adaptability to the deformation of corrugated pipe 13 and corrugated pipe 2 14. The outer sides of pipe section 11 and pipe section 2 12 are covered with a composite insulation layer 4. On the one hand, it provides good insulation for pipe section 11 and pipe section 2 12. On the other hand, when corrugated pipe 13 and corrugated pipe 2 14 deform, the aluminum foil protective layer 42 is not easily deformed. By setting the segmented insulation layer structure of composite insulation layer 4 and flexible insulation layer 5, the EGR pipe has a better insulation effect and stronger durability.

[0031] Among them, insulation cotton 141 is made of thickened insulation material, such as thickened glass fiber insulation layer, and insulation cotton 252 is made of rubber and plastic insulation cotton with stronger deformation resistance, so as to improve the shock absorption and deformation resistance of corrugated pipe 13 and corrugated pipe 214.

[0032] The composite insulation layer 4 is fixed in the limiting groove 6 by clamp 7. The composite insulation layer 4 can be replaced by removing clamp 7. The replacement of the insulation layer is convenient and quick. In the flexible insulation layer 5, the steel wire braided layer is connected to the flange plate 29 of the pipe section 3 15 through flange plate 3 10. The fixing of the steel wire braided layer 51 is more firm and reliable, and it has a stronger adaptability to the deformation of corrugated pipe 1 13 and corrugated pipe 2 14, thus improving the durability of the EGR pipe.

[0033] The technical features of this utility model not described can be implemented by or by using existing technology, and will not be repeated here. Of course, the above description is not a limitation of this utility model, and this utility model is not limited to the examples above. Any changes, modifications, additions or substitutions made by those skilled in the art within the scope of this utility model should also be within the protection scope of this utility model.

Claims

1. An EGR pipe for large displacement diesel engines, comprising a conveying pipe (1), an inlet joint (2) and an outlet joint (3) arranged at both ends of said conveying pipe (1), characterised in that, The conveying pipe (1) comprises a pipe section one (11) connected with the inlet joint (2), a pipe section two (12) connected with the outlet joint (3), a corrugated pipe one (13) with one end connected with the pipe section one (11), a corrugated pipe two (14) with one end connected with the pipe section two (12), and a pipe section three (15) connected and arranged between the corrugated pipe one (13) and the corrugated pipe two (14). The outer sides of the pipe section one (11) and the pipe section two (12) are covered with a composite heat preservation layer (4), and the outer sides of the corrugated pipe one (13) and the corrugated pipe two (14) are covered with a flexible heat preservation layer (5).

2. The EGR pipe for a large displacement diesel engine according to claim 1, characterized by The flexible heat preservation layer (5) comprises a steel wire braided layer (51) and heat preservation cotton two (52) arranged in sequence from outside to inside, and the heat preservation cotton two (52) is in contact with the outer sides of the corrugated pipe one (13) and the corrugated pipe two (14).

3. The EGR pipe for a large displacement diesel engine according to claim 2, characterized by The composite heat preservation layer (4) comprises heat preservation cotton one (41) and aluminum foil protection layer (42) arranged in sequence from inside to outside.

4. The EGR pipe for a large displacement diesel engine according to claim 3, characterized by The side parts of the pipe section one (11) and the pipe section two (12) are provided with limiting grooves (6), the outer sides of the composite heat preservation layer (4) are sleeved with hoops (7), and the hoops (7) are pressed in the limiting grooves (6).

5. The EGR pipe for a large displacement diesel engine according to claim 4, characterized by One end of the pipe section one (11) close to the corrugated pipe one (13) is provided with a flange plate one (8), both ends of the pipe section two (12) are provided with flange plates two (9), both ends of the flexible heat preservation layer (5) are provided with flange plates three (10), and the flexible heat preservation layer (5) is connected with the pipe section one (11) and the pipe section two (12) through the flange plates three (10) respectively.

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