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CN-115727139-B - Doublestage backpressure adjustment mechanism

CN115727139BCN 115727139 BCN115727139 BCN 115727139BCN-115727139-B

Abstract

The invention relates to a two-stage back pressure regulating mechanism which comprises a throttle pipe (1), a small throttle valve (3), a large throttle valve (4), a large throttle valve shaft (7), a bent pipe (8), a flange bushing (10), a sealing bushing (13) and a small throttle valve shaft (17), wherein the large throttle valve shaft and the small throttle valve shaft are rotated to regulate different positions of the large throttle valve shaft and the small throttle valve shaft in the conical surface of the throttle pipe, so that the regulation and locking of the required back pressure can be realized, the regulation of the exhaust back pressure of a test engine or a test mechanism is realized, the complex regulation of an exhaust pipeline is not needed, and the two-stage back pressure regulating mechanism has the characteristics of simplicity in processing, rapidness in installation, high regulating efficiency and convenience in fault treatment.

Inventors

  • ZHUANG LI
  • HOU LINLIN
  • Meng Bijun
  • WANG CUICUI
  • YU BO

Assignees

  • 中国北方发动机研究所(天津)

Dates

Publication Date
20260505
Application Date
20221117

Claims (10)

  1. 1. A two-stage back pressure adjusting mechanism is characterized by comprising a throttle pipe (1), a small throttle valve (3), a large throttle valve (4), a large throttle valve shaft (7), a bent pipe (8), a flange bushing (10), a sealing bushing (13) and a small throttle valve shaft (17), wherein an inner cavity of the throttle pipe (1) is composed of a cylindrical pipe and a conical throttle pipe, the rear end of the conical throttle pipe of the throttle pipe (1) is fixedly connected with the front end of the bent pipe (8), the bent pipe (8) is an intermediate connecting pipe for connecting the pipe diameter of the bent pipe to 90 degrees, the bottom end of the bent pipe is used for connecting an exhaust pipeline of a test room, the sealing bushing (13) is arranged in the flange bushing and fixedly connected with the flange bushing, the flange bushing penetrates through the outer wall of the bent pipe (8) and is fixedly connected with the flange bushing, one end of the large throttle valve shaft (7) penetrates through the sealing bushing (13) and is fixedly connected with the large throttle valve shaft (4), one end of the small throttle pipe (17) penetrates through a central hole of the large throttle pipe and is fixedly connected with the small throttle valve shaft, the other end of the small throttle pipe is fixedly connected with the small throttle valve shaft (3), and in the test process, and the back pressure of the large throttle valve shaft (17) and the small throttle valve shaft (17) is accurately adjusted in the position of the large throttle valve shaft (17) is measured in the throttle valve shaft (3) in the test process.
  2. 2. The two-stage back pressure adjusting mechanism according to claim 1, wherein two connecting flanges are arranged on two perpendicular end faces of the bent pipe (8), wherein the end face flange plate is connected with the throttle pipe (1), the end face flange plate is provided with an inward concave spigot, the tolerance is matched with a large flange boss spigot of the throttle pipe by adopting H7, the depth of the inward concave spigot is 0.15mm larger than the sum of the boss height of the large flange spigot of the throttle pipe and the thickness of the sealing gasket, and the flange is provided with an installation connecting through hole.
  3. 3. The two-stage back pressure regulating mechanism as set forth in claim 2, wherein the pipe diameter of the bent pipe (8) is provided with a screw thread supporting opening, the screw thread specification of the screw thread supporting opening is matched with the screw thread of the flange bush (10), and the central axis is designed coaxially with the center of the end face flange.
  4. 4. The two-stage back pressure adjusting mechanism according to claim 2, wherein the flange bushing (10) is provided with a locking threaded flange, the specification of a threaded hole on the flange is matched with that of a locking unthreaded hole on the sealing bushing, a flange bushing thread is arranged on a flange bushing boss, the specification of the thread is matched with that of a thread supporting hole on the bent pipe bending diameter, the inner hole of the flange bushing is matched with the outer diameter of the sealing bushing (13), and a clearance fit gap of 0.2mm is adopted.
  5. 5. The two-stage back pressure adjusting mechanism according to claim 3, wherein the sealing bush (13) is provided with a sealing bush flange, a locking unthreaded hole on the flange is matched with a threaded hole on the flange of the flange bush (10), and the specification of the threaded hole in the sealing bush (13) is matched with the end face long thread of the large throttle shaft (7).
  6. 6. The two-stage back pressure regulating mechanism of claim 4, wherein the large throttle valve (4) is a conical truncated cone, the included angle of the conical surface of the large throttle valve is 60 degrees, the inner hole of the large throttle valve (4) is matched with the outer diameter of the small throttle valve shaft (17), clearance fit is adopted, the end face of a boss arranged in the large throttle valve (4) is a locking sealing face which is tightly pressed and jointed with a locking nut II (12), the other end face of the internal thread of the large throttle valve is a large throttle valve sealing face, and the sealing face is tightly pressed and jointed with a copper gasket II (14).
  7. 7. The two-stage back pressure regulating mechanism according to claim 6, wherein the small throttle valve (3) is a boss structure of a conical throttle surface at the tail of a spherical throttle surface at the front end.
  8. 8. The two-stage back pressure regulating mechanism according to claim 7, wherein the small throttle valve (3) has a spherical radius R30 and a tail cone angle of 64 degrees.
  9. 9. A two-stage back pressure regulating mechanism according to any one of claims 1-8, wherein a boss is arranged in the small throttle valve (3) and is internally provided with a boss internal threaded hole, the specification of the threaded hole is matched with that of the end face of the small throttle valve shaft (17), and the sealing end face of the boss is tightly pressed and jointed with a locking nut I (2).
  10. 10. The two-stage back pressure regulating mechanism according to any one of claims 1-8, wherein the throttle pipe (1) is made of ferrosilicon cast iron in heat-resistant materials, 3 measuring point interfaces are arranged in the circumferential direction of the periphery of the cylindrical pipe, each measuring point is spaced by 60 degrees, and the threads of the measuring point interfaces are matched with the threads of temperature and pressure sensors.

Description

Doublestage backpressure adjustment mechanism Technical Field The invention belongs to the technical field of engine and component tests, and particularly relates to a two-stage back pressure regulating mechanism. Background The test engine is different from the target complete machine structure and test conditions, in view of the structural specificity, the test engine is difficult to completely agree with the target complete machine performance, particularly, great difference exists in an air inlet system and an air outlet system, in order to simulate the exhaust resistance generated by a supercharger, an EGR and other units connected behind an exhaust pipe of the complete machine more truly, the back pressure regulating device is often designed behind the exhaust pipe of the test engine, and the exhaust pressure of the test engine is agreed with the target complete machine by regulating the back pressure regulating device, so that the consistency of the test engine performance and the target complete machine performance is realized. The existing low-pressure simulation test bed for the characteristics of the internal combustion engine consists of an air inlet simulation device, an exhaust back pressure regulating device, an atmospheric back pressure regulating device in an engine crankcase and a low-pressure starting device for simulating a plateau environment, wherein the exhaust back pressure regulating device consists of an exhaust pressure stabilizing cylinder, a vacuumizing device connected with the exhaust pressure stabilizing cylinder through a pipeline and an exhaust pressure regulating valve arranged on the pipeline, and the low-pressure test bed can simulate atmospheric pressures at different altitudes. However, the exhaust back pressure adjusting device disclosed in the prior art has the technical problems that the exhaust back pressure is slow to adjust and the exhaust back pressure is difficult to accurately control. Disclosure of Invention The invention provides a two-stage back pressure adjusting mechanism, which aims to solve the technical problem that the back pressure of a test engine and related test exhaust needs to be adjusted according to target resistance. The invention provides a two-stage back pressure regulating mechanism, which is characterized by comprising a throttle pipe (1), a small throttle valve (3), a large throttle valve (4), a large throttle valve shaft (7), a bent pipe (8), a flange bushing (10), a sealing bushing (13) and a small throttle valve shaft (17), wherein an inner cavity of the throttle pipe (1) consists of a cylindrical pipe and a conical throttle pipe, the rear end of the conical throttle pipe of the throttle pipe (1) is fixedly connected with the front end of the bent pipe (8), the bent pipe (8) is an intermediate connecting pipe with the pipe diameter of 90 degrees, the bottom end of the bent pipe is used for being connected with an exhaust pipeline of a test chamber, the sealing bushing (13) is arranged in the flange bushing and is fixedly connected with the flange bushing, the flange bushing penetrates through the outer wall of the bent pipe (8) and is fixedly connected, one end of the large throttle valve shaft (7) penetrates through the sealing bushing (13) and is fixedly connected with the small throttle valve shaft (17), one end of the small throttle valve shaft (17) penetrates through a central hole of the large throttle valve (7) and is fixedly connected with the small throttle valve shaft, the other end of the small throttle valve shaft is fixedly connected with the small throttle valve shaft (3) and is fixedly connected with the small throttle valve shaft (3) in the test chamber, the back pressure of the large throttle valve shaft is accurately regulated in the test chamber, and the position of the throttle valve shaft is accurately regulated in the throttle valve 1 and the throttle valve is measured and the throttle valve shaft is in the throttle valve shaft 3 is in the process. The invention has the advantages that the large throttle valve shaft and the small throttle valve shaft are rotated, so that the large throttle valve and the small throttle valve are adjusted at different positions in the conical surface of the throttle pipe, the adjustment and locking of the required back pressure can be realized, the adjustment of the exhaust back pressure of the test engine or the test mechanism is realized, the complex adjustment of an exhaust pipeline is not needed, and the invention has the characteristics of simple processing, quick installation, high adjustment efficiency and convenient fault treatment, and in the engine test and the component test, the economic cost and the time cost of product development are greatly reduced. Drawings FIG. 1 is a cross-sectional view of a dual stage back pressure adjustment mechanism according to the present invention; FIG. 2 is a schematic diagram of a dual stage back pressure adjustment mechanism according