Hydraulic damper with a hydraulic stop arrangement

Patent metadata

Field	Value
Publication number	US-9657803-B2
Application number	US-201414511577-A
Country	US
Kind code	B2
Filing date	Oct 10, 2014
Priority date	May 14, 2014
Publication date	May 23, 2017
Grant date	May 23, 2017

Abstract

A hydraulic damper ( 1 ) includes a tube ( 3 ) filled with working liquid, wherein at least one end of the tube ( 3 ) is provided with a narrower section ( 31 ) of a smaller diameter provided with at least one axial groove ( 12 ). The damper ( 1 ) includes at least one additional piston assembly ( 13 ) having diameter (D 3 ) smaller than diameter (D 1 ) of the main section of the tube ( 3 ), displaceable along with the main piston assembly ( 4 ) and apt to be introduced in the narrower section of the tube ( 3 ) to generate additional damping force. The narrower section ( 31 ) extends through a conical section ( 32 ) into the main section ( 33 ) of the tube ( 3 ) and the conical section ( 32 ) of the tube ( 3 ) is internally shaped to form axial bridges ( 15 ) defining said axial grooves ( 12 ) extending along the length of said conical section ( 32 ), each comprising a cylindrical section ( 151 ).

First claim

What is claimed:

1. A hydraulic damper comprising a tube filled with working liquid, a main piston assembly disposed slidably inside the main section of the tube, attached to a piston rod led outside the damper and dividing the tube into a rebound chamber and a compression chamber, rebound and compression valve assemblies to control the flow of working liquid within the tube during a rebound and compression stroke of the damper, wherein at least one end of the tube is provided with a narrower section of a smaller diameter provided at least partially with at least one axial groove and the damper is further provided with at least one additional piston assembly having a diameter smaller than a diameter of the main section of the tube, displaceable along with the main piston assembly and apt to be introduced in said narrower section of the tube to generate additional damping force;
said narrower section extends through a conical section into the main section of the tube and said conical section is internally shaped to form a plurality of axial bridges extending radially inwardly and defining said at least one axial groove between said axial bridges, and wherein said at least one axial groove extends along the length of said conical section, each of said axial bridges comprising a cylindrical section, a conical section and a transitional section between said cylindrical and conical sections, wherein said cylindrical sections of said axial bridges define a semi-cylindrical section of said tube to provide guidance for said at least one additional piston assembly, and said conical sections of said axial bridges define a semi-conical section of said tube;
said at least one groove having a lower portion extending along the same axial length as said cylindrical sections of said axial bridges, a middle portion extending along the same axial length as said transitional sections of said axial bridges, and an upper portion extending along the same axial length as said conical sections of said bridges; and
the width of said lower portion of said at least one groove between said axial bridges tapering inwardly along the length of said lower portion toward said middle portion, and the width of said upper portion of said at least one groove between said axial bridges tapering inwardly along the length of said upper portion toward said middle portion.

2. The hydraulic damper according to claim 1 , wherein said additional piston assembly is provided with rebound and compression valve assemblies to control the flow of working liquid passing through the additional piston assembly.

3. The hydraulic damper according to any of the preceding claims, wherein the bridges comprise annular sections at both sides of respective cylindrical and conical sections defining cross-sectional areas of said at least one axial groove between the bridges in a plane perpendicular to the damper axis.

4. The hydraulic damper according to claim 1 , wherein it is a twin-tube damper and said conical section is located at the compression end of the damper main tube.

5. The damper according to claim 1 , wherein said at least one additional piston assembly is coaxially fixed with said main piston assembly.

6. The damper according to claim 1 , wherein said at least one additional piston assembly is provided with a sealing ring split over its perimeter and fitted in a circumferential groove of said at least one additional piston assembly.

7. The damper according to claim 1 , wherein said tube extends about and along an axis, and said axial bridges each extend radially inwardly toward said axis.

8. The damper of claim 7 , wherein said tube defines an outer surface and an inner surface, and wherein each of said axial bridges defines an indentation on said outer surface of said tube.

9. A method of manufacturing a hydraulic damper, comprising a tube filled with working liquid, a main piston assembly disposed slidably inside the main section of the tube, attached to a piston rod led outside the damper and dividing the tube into a rebound chamber and a compression chamber, rebound and compression valve assemblies to control the flow of working liquid within the tube during a rebound and compression stroke of the damper, wherein at least one end of the tube is provided with a narrower section of a smaller diameter provided at least partially with at least one axial groove and the damper is further provided with at least one additional piston assembly having a diameter smaller than a diameter of the main section of the tube, displaceable along with the main piston assembly and apt to be introduced in said narrower section of the tube to generate additional damping force, wherein the method comprises the steps of:
shaping the tube to form a conical section between said narrower section and the main section of the tube;
shaping said conical section of the tube in order to form a plurality of axial bridges extending radially inwardly and defining said at least one axial groove between said axial bridges, and wherein said at least one groove extends along the length of said conical section, each of said axial bridges comprising a cylindrical section, a conical section and a transitional section between said cylindrical and conical sections, wherein said cylindrical sections of said axial bridges define a semi-cylindrical section of said tube to provide guidance for said at least one additional piston assembly, and said conical sections of said axial bridges define a semi-conical section of said tube;
said at least one groove having a lower portion extending along the same axial length as said cylindrical sections of said axial bridges, a middle portion extending along the same axial length as said transitional sections of said axial bridges, and an upper portion extending along the same axial length as said conical sections of said axial bridges; and
the width of said lower portion of said at least one groove between said axial bridges tapering inwardly along the length of said lower portion toward said middle portion, and the width of said upper portion of said at least one groove between said axial bridges tapering inwardly along the length of said upper portion toward said middle portion.

10. The method according to claim 9 , wherein said step of shaping the tube to form said conical section involves drawing.

11. The method according to claim 10 , wherein said step of shaping said conical section of the tube involves externally stamping said conical section radially by stamps shaping the bridges.

12. The method according to claim 9 , wherein said at least one additional piston assembly is coaxially fixed with said main piston assembly.

13. The method according to claim 9 , wherein said at least one additional piston assembly is provided with a sealing ring split over its perimeter and fitted in a circumferential groove of said at least one additional piston assembly.

14. The method according to claim 9 , wherein said tube extends about and along an axis, and said axial bridges each extend radially inwardly toward said axis.

15. The method of claim 14 , wherein said tube defines an outer surface and an inner surface, and wherein each of said axial bridges defines an indentation on said outer surface of said tube.

Assignees

• Slusarczyk Pawel
• Knapczyk Marcin
• Wrzesinski Jakub
• Beijingwest Ind Co Ltd

Inventors

• Slusarczyk Pawel
• Knapczyk Marcin
• Wrzesinski Jakub

Classifications

• B21D22/20

  Deep-drawing (special deep-drawing arrangements in, or in connection with, presses B21D24/00) · CPC title

• B21D53/88

  other parts for vehicles, e.g. cowlings, mudguards · CPC title

• F16F9/3235

  of cylinders (F16F9/483 takes precedence) · CPC title

• F16F9/3242

  of cylinder ends, e.g. caps · CPC title

• F16F9/483

  characterised by giving a particular shape to the cylinder, e.g. conical · CPC title