Search

KR-20260066179-A - Gas injector with damper

KR20260066179AKR 20260066179 AKR20260066179 AKR 20260066179AKR-20260066179-A

Abstract

The present invention relates to a gas injector for injecting gaseous fuel, wherein the gas injector comprises 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) opens and closes a gas path (14) on a sealing sheet (11) disposed on a first end of the gas injector, 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 lubricating chamber (4) filled with lubricating oil and having the armature (20) and the armature pin (23) disposed therein, wherein the lubricating oil provides lubrication within the lubricating chamber (4), and a return element (10) for returning the closing element (3) to a closed initial position, wherein the lubricating chamber (4) is filled with gas and liquid lubricating oil for damping during movement of the closing element (3). It is filled, and the liquid to gas ratio is in the range of 70 volume%/30 volume% to 95 volume%/5 volume%.

Inventors

  • 칼마르, 케빈
  • 바이어, 크리스티안
  • 일그너, 프랭크
  • 크레허, 틸로
  • 울만, 외르크

Assignees

  • 로베르트 보쉬 게엠베하

Dates

Publication Date
20260512
Application Date
20240718
Priority Date
20230929

Claims (9)

  1. As a gas injector for injecting gaseous fuel, - 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) on a sealing sheet (11) disposed on a first end of the gas injector, the armature (20) is connected to the armature pin (23) and the armature pin (23) is operatively connected to the valve needle (30), the closing element (3), - A closed lubricating chamber (4) filled with lubricating oil and having the armature (20) and the armature pin (23) disposed therein, wherein the lubricating oil provides lubrication within the lubricating chamber (4), and - Includes a return element (10) that returns the above-mentioned closing element (3) to a closed initial position, - The above lubricating oil chamber (4) is filled with gas and liquid lubricating oil for damping during movement of the closing element (3), and - A gas injector in which the ratio of the liquid to the gas is in the range of 70 volume%/30 volume% to 95 volume%/5 volume%.
  2. In claim 1, the lubricating oil chamber (4) comprises a lubricating oil housing (400) having a plurality of housing members, and exactly one housing member is a metal bellows operatively connected to the closing element (3), a gas injector.
  3. In paragraph 2, a plurality of housing members of the lubricating oil housing (400) are made of metal, particularly steel, for the gas injector.
  4. In paragraph 3, the metal housing members are connected to each other by welded joints (44), forming a gas injector.
  5. A gas injector according to claim 4, wherein at least one welded joint includes a disconnection portion (44a), and the seal between the two housing members is formed by a sealing portion, in particular an O-ring (42).
  6. A gas injector according to any one of claims 1 to 5, wherein at least one housing member of the lubricating oil housing (400) is made of an elastomeric material.
  7. In paragraph 6, the housing member made of an elastomeric material is a gas injector, which is a sealing plug (41) or a flat gasket.
  8. A gas injector according to any one of claims 1 to 5, wherein all housing members of the lubricating oil housing (400) are made of metal.
  9. A gas injector according to any one of claims 1 to 8, wherein the pressure of the gas in the lubricating oil chamber (4) is in the range from ambient pressure to 4 x 10⁵ Pa.

Description

Gas injector with damper The present invention relates to a gas injector for injecting a gaseous medium, such as hydrogen, natural gas, methane, LPG, ammonia, etc., into the combustion chamber of an internal combustion engine having improved damping characteristics using a hydraulic damper. Gas injectors are known in various forms in the prior art. Due to relatively high gas pressure, the closing element, particularly the valve needle, strikes the sealing seat forcefully, especially during the closing process. To avoid unnecessarily shortening the lifespan of the gas injector, damping devices must be provided. Simple solutions are desirable to avoid unnecessarily increasing manufacturing costs and maintenance. In contrast, the gas injector according to the present invention for injecting gaseous fuel having the features of claim 1 has the advantage that simple and reliable damping of the closing element is achieved during the closing process of the gas injector. The damping is guaranteed over the entire life of the gas injector. In particular, since the damping is very robust and cost-effective, it is suitable for mass production of the gas injector. In addition, the damping according to the present invention requires only a very small installation space. The damping also prevents vibration excitation of other members of the gas injector during the closing process, so the load on other members can be significantly reduced during operation. This is achieved according to the present invention by the gas injector comprising a magnetic actuator having an armature, an internal pole, and a coil. Additionally, the gas injector comprises a closing element having a valve needle, and the closing element releases and closes the gas path on a sealing sheet on a first end of the gas injector. Thereby, gas is injected, for example, into a combustion chamber or the injection is terminated. Additionally, the closing element comprises an armature pin connected to the armature and actuated to the valve needle. The valve needle and the armature pin are preferably rod-shaped members that loosely contact each other's opposing faces and can move independently of each other. The gas injector also comprises a lubricating oil chamber closed by a lubricating oil housing, and this lubricating oil chamber is filled with lubricating oil. The armature and the armature pin are positioned within the lubricating oil chamber, and the lubricating oil provides lubrication for the members located within the lubricating oil chamber. A return element returns the closing element to its initial closed position. The lubricating oil chamber is preferably formed as a closed chamber by a flexible sealing element, in particular a bellows, and the flexible sealing element is positioned on the closing element. The flexible sealing element seals the lubricating oil chamber from the gas passing through the gas path. Additionally, the gas injector includes a damping device for damping the closing process of a closing element placed within the lubricating oil chamber. The damping device contains the gas placed within the lubricating oil chamber, particularly for volume compensation. Thus, a liquid is provided within the lubricating oil chamber, particularly for damping during the closing process. The lubricating oil chamber is preferably closed by a lubricating oil housing having a plurality of members. The ratio of liquid, i.e., liquid lubricating oil to gas, within the lubricating oil chamber is in the range of 70/30 volume% to 95/5 volume%. Particularly preferably, the ratio of liquid to gas is in the range of 80/20 volume% to 90/10 volume%. More preferably, the ratio of liquid to gas within the lubricating oil chamber is about 85:15 volume%. This ensures that volume compensation is achieved by the gas within the lubricating oil chamber. Another advantage of a partially gas-filled lubricating oil chamber is that, in the event of temperature changes where the volume of the liquid lubricant may expand, this volume can be compensated for by the gas within the chamber. When the liquid lubricant expands with temperature, the gas within the chamber is slightly compressed, compensating for the volume change of the liquid lubricant due to temperature. By using liquid and gas within the lubricating oil chamber, complex damping by additional metal bellows on the lubricating oil housing, for example provided only for damping, can be omitted. Since the lubricating oil chamber is filled with gas in addition to liquid lubricating oil, a damping device integrated into the lubricating oil chamber is obtained. The damping device ensures damping of movable parts located within the lubricating oil chamber, particularly during the closing process. Additionally, the damping device can compensate for changes in length due to temperature of the members within the lubricating oil chamber or the housing members of the lubricating oil housing. In particular, for example, changes i