Solenoid fluid injector with corrosion prevention structure
View Patent ↗A fluid injector includes a valve structure movable in the passageway between a first position and a second position. The valve structure includes a hollow tube having a longitudinal axis and a valve member connected to an end of the tube by a weld, with a weld zone being defined inside of the tube generally adjacent to the weld. The tube has surfaces defining a through-hole that is disposed transversely with respect to the longitudinal axis of the tube. The through-hole permits the fluid to enter an interior of the tube. Corrosion prevention structure is disposed in the tube between the through-hole and the valve member to prevent the fluid in the tube from accessing the weld zone.
1. A fluid injector having an inlet, an outlet, and a passageway providing a fluid flow conduit from the inlet to the outlet, the fluid injector comprising:
a valve structure movable in the passageway between a first position and a second position, the valve structure including a hollow tube having a longitudinal axis and a valve member connected to an end of the tube by a weld, with a weld zone being defined inside of the tube generally adjacent to the weld, the tube having surfaces defining a through-hole that is disposed transversely with respect to the longitudinal axis of the tube, the through-hole being constructed and arranged to permit the fluid to enter an interior of the tube,
a seat, at the outlet, having at least one seat passage in communication with the passageway, the seat contiguously engaging a portion of the valve member in the first position thereby closing the at least one seat passage and preventing fluid from exiting the at least one seat passage, the valve member, in the second position of the valve structure being spaced from the at least one seat passage so that fluid can move through the passageway and exit through the at least one seat passage, and
corrosion prevention structure disposed in the tube between the through-hole and the valve member, constructed and arranged to prevent the fluid in the tube from accessing the weld zone.
2. The injector of claim 1 , wherein the valve member is in the form of a ball.
3. The injector of claim 1 , wherein the tube and the valve member are each composed of stainless steel material.
4. The injector of claim 1 , wherein the corrosion prevention structure is a plug composed of an elastomer material.
5. The injector of claim 4 , wherein the plug is of spherical shape.
6. The injector of claim 1 , wherein the corrosion prevention structure is constructed and arranged to be resistant to urea solution as the fluid.
7. The injector of claim 6 , wherein the corrosion prevention structure is composed of ethylene propylene diene monomer (EPDM) rubber or of fluorocarbon (FKM) rubber.
8. The injector of claim 1 , wherein the corrosion prevention structure is constructed and arranged to be resistant to hydrocarbon fuels as the fluid.
9. The injector of claim 1 , wherein the tube includes a constant diameter portion and a tapered portion, which is disposed adjacent to the valve member, the through-hole being provided in the constant diameter portion.
10. The injector of claim 9 , wherein the corrosion prevention structure is a spherical plug disposed in the constant diameter portion of the tube.
11. A method of preventing corrosion in a fluid injector, the fluid injector having an inlet, an outlet, a passageway providing a fluid flow conduit from the inlet to the outlet, and a valve structure movable in the passageway relative to a seat between a first position engaged with the seat to prevent fluid from exiting the outlet and a second position disengaged from the seat to permit fluid to exit the outlet, the valve structure including a hollow tube having a longitudinal axis and a valve member connected to an end of the tube by a weld, with a weld zone being defined inside of the tube generally adjacent to the weld, the method comprising the steps of:
providing a through-hole in the tube that is disposed transversely with respect to the longitudinal axis of the tube, the through-hole being constructed and arranged to permit the fluid to enter an interior of the tube, and
preventing the fluid in the interior of the tube from accessing the weld zone.
12. The method of claim 11 , wherein the preventing step includes providing a plug in the tube between the through-hole and the valve member.
13. The method of claim 12 , wherein the plug is provided to be resistant to urea solution as the fluid or to hydrocarbon fuels as the fluid.
14. The method of claim 13 , wherein the plug is composed of ethylene propylene diene monomer (EPDM) rubber or of fluorocarbon (FKM) rubber.
15. The method of claim 11 , wherein the valve member is in the form of a ball.
16. The method of claim 15 , wherein the plug is provided from an elastomer material.
17. The method of claim 16 , wherein the plug is provided as a spherical member.
18. The method of claim 11 , wherein the tube and the valve member are each composed of stainless steel material.
19. The method of claim 11 , wherein the tube includes a constant diameter portion and a tapered portion, which is disposed adjacent to the valve member, and wherein the through-hole is provided in the constant diameter portion.
20. The method of claim 19 , wherein the plug is of spherical shape and is disposed in the constant diameter portion of the tube.