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CN-121986215-A - Gas injector with damper

CN121986215ACN 121986215 ACN121986215 ACN 121986215ACN-121986215-A

Abstract

The invention relates to a gas injector for injecting gaseous fuel, comprising a magnetic actuator (2) having an armature (20), an inner pole (21) and a coil (22), a closing element (3) having a valve needle (30) and an armature pin (23), wherein the valve needle (30) releases and closes a gas path (14) at a sealing seat (11) arranged at a first end of the gas injector, wherein the armature (20) is connected to the armature pin (23) and the armature pin (23) is in operative connection with the valve needle (30), a closed lubricant chamber (4) filled with lubricant and in which the armature (20) and the armature pin (23) are arranged, wherein the lubricant provides a lubricating action in the lubricant chamber (4), and a resetting element (10) resetting the closing element (3) into a closed starting position, wherein the lubricant chamber (4) is filled with lubricant and the armature pin (23) is in a liquid phase ratio of at least 95%/in a liquid phase of the range of motion (3 to a damping rate of 70% of the liquid phase (3).

Inventors

  • K. Kalmar
  • BAYER CORNELIA
  • ILGNER FRANK
  • T. Claire
  • J. Ullman

Assignees

  • 罗伯特·博世有限公司

Dates

Publication Date
20260505
Application Date
20240718
Priority Date
20230929

Claims (9)

  1. 1. A gas injector for blowing in gaseous fuel, the gas injector comprising: a magnetic actuator (2) having an armature (20), an inner pole (21) and a coil (22); -a closing element (3) having a valve needle (30) and an armature pin (23), wherein the valve needle (30) releases and closes a gas path (14) at a sealing seat (11) arranged at a first end of the gas injector, wherein the armature (20) is connected to the armature pin (23) and the armature pin (23) is operatively connected to the valve needle (30); -a closed lubricant chamber (4) filled with a lubricant and in which the armature (20) and the armature pin (23) are arranged, wherein the lubricant provides a lubrication in the lubricant chamber (4); a reset element (10) which resets the closing element (3) into a closed starting position, Wherein the lubricant chamber (4) is filled with a gas and a liquid lubricant for damping the movement of the closing element (3), and Wherein the volume ratio of the liquid to the gas is in the range of 70%/30% to 95%/5%.
  2. 2. The gas injector according to claim 1, wherein the lubricant chamber (4) has a lubricant housing (400) comprising a plurality of housing components, wherein exactly one housing component is a metal bellows, which is operatively connected to the closing element (3).
  3. 3. The gas injector according to claim 2, wherein the plurality of housing components of the lubricant housing (400) are made of metal, in particular steel.
  4. 4. A gas injector according to claim 3, wherein the metal housing members are connected to each other by a welded connection (44).
  5. 5. The gas injector according to claim 4, wherein at least one welded connection has an interruption (44 a), wherein the seal between the two housing components is achieved by means of a seal, in particular an O-ring (42).
  6. 6. The gas injector according to any of the preceding claims, wherein at least one housing member of the lubricant housing (400) is made of an elastomeric material.
  7. 7. The gas injector according to claim 6, wherein the housing member made of an elastomeric material is a closing plug (41) or a flat seal.
  8. 8. The gas injector according to any one of claims 1 to 5, wherein all housing components of the lubricant housing (400) are made of metal.
  9. 9. The gas injector according to any of the preceding claims, wherein the pressure of the gas in the lubricant chamber (4) is in the range of ambient pressure to 4 x10 5 Pa.

Description

Gas injector with damper Technical Field The present invention relates to a gas injector for injecting a gaseous medium, such as hydrogen, natural gas, methane, liquefied Petroleum Gas (LPG), ammonia, etc., into a combustion chamber of an internal combustion engine, the gas injector having damping characteristics improved by means of a hydraulic damper. Background A number of different configurations of gas injectors are known from the prior art. Due to the relatively high gas pressure, in particular during closing, hard impacts of the closing element, in particular the valve needle, on the sealing seat can occur. In order to unnecessarily shorten the service life of the gas injector, damping means should be provided. In order to unnecessarily increase the production and maintenance costs, simple solutions should be preferred. Disclosure of Invention In contrast, the gas injector according to the invention for injecting gaseous fuel, which has the features of claim 1, has the advantage that a simple and reliable damping of the closing element can be achieved during the closing of the gas injector. Here, damping is ensured throughout the service life of the gas injector. This damping is also particularly robust and cost-effective and is therefore suitable for mass production of gas injectors. Furthermore, the damping according to the invention requires only a very small installation space. Moreover, the damping prevents vibration excitation of other components of the gas injector during the closing process, so that the load of the other components in operation can be significantly reduced. According to the invention, this is achieved in that the gas injector has a magnetic actuator with an armature, an inner pole and a coil. Furthermore, the gas injector comprises a closing element with a valve needle, wherein the closing element releases and closes the gas path at the first end of the gas injector at the sealing seat. Thus, for example, the gas is blown into the combustion chamber or the blowing is terminated. The closing element further comprises an armature pin which is connected to the armature and is operatively connected to the valve needle. The valve needle and the armature pin are preferably rod-shaped components which rest loosely against one another on the opposite end faces and can be moved independently of one another. The gas injector further comprises a lubricant chamber enclosed by the lubricant housing, which lubricant chamber is filled with lubricant. The armature and armature pin are disposed in a lubricant chamber, wherein the lubricant provides lubrication to components located in the lubricant chamber. The reset element resets the closure element into the closed start bit state. The lubricant chamber is preferably provided as a closed space, in part, by means of a flexible sealing element, in particular a bellows, wherein the flexible sealing element is arranged on the closing element. The flexible sealing element seals the lubricant chamber against the gas at the gas path passing by. Furthermore, the gas injector comprises a damping device for damping a closing process of the closing element, which damping device is arranged in the lubricant chamber. The damping device comprises a gas arranged in the lubricant chamber, in particular for volume compensation. Thus, a liquid for damping, in particular during closing, is provided in the lubricant chamber. The lubricant chamber is closed by a lubricant housing, which preferably has a plurality of components. The volume ratio of liquid, i.e. liquid lubricant to gas in the lubricant chamber is in the range of 70%/30% to 95%/5%. Particularly preferably, the volume ratio of liquid to gas is in the range 80%/20% to 90%/10%. Further preferably, the volume ratio of liquid to gas in the lubricant cell is about 85% to 15%. This ensures that volume compensation is also possible by the gas present in the lubricant chamber. Another advantage of a lubricant chamber partially filled with gas is that temperature variations may cause a volume expansion of the liquid lubricant, which can be compensated for by the gas in the lubricant chamber when the temperature varies. When the liquid lubricant expands due to temperature, the gas in the lubricant chamber is slightly compressed and compensates for the volume change of the liquid lubricant due to temperature. By using liquids and gases in the lubricant chamber, complex damping can be dispensed with in particular, for example by providing a further metal bellows on the lubricant housing for damping only. Since the lubricant chamber is additionally filled with a gas in addition to the liquid lubricant, a damping device is formed which is integrated in the lubricant chamber. The damping device ensures damping of the movable part located in the lubricant chamber, in particular during the closing process. Furthermore, the damping device is able to compensate for temperature-induced length changes of the components