DESC:TWIN CYLINDER MONOTUBE SHOCK ABSORBER

Field of the invention

The present invention generally relates to a field of a suspension assembly of automobiles and more particularly, the present invention relates to a twin cylinder monotube shock absorber.

Background of the invention

Shock absorbers are necessary components in vehicles. Shock absorbers are designed to dampen force and dissipate energy between the passenger compartment of the vehicle and the wheels of the vehicle when the wheels of the vehicle encounter a bump or a dip or any deviation in terrain.

Referring to figure 1, a monotube shock absorber (10) in accordance with the prior art is shown. As well known, the monotube shock absorber (10) essentially comprises a single pressure tube (2) that is fastened to a housing (4) by threading. The pressure tube (2) contains a piston rod assembly. The pressure tube (2) is a steel tube filled with hydraulic fluid like oil. The housing (4) contains a gas chamber. The housing (4) facilitates the oil to flow from the pressure tube (2) to the gas chamber through a canister to achieve damping.

However, the monotube shock absorbers have a number of drawbacks. For example, a thicker pressure tube (2) is required to accommodate threading. In addition, a cost required for pressure tube (2) threading and machining processes is realistically high. Also, the pressure tube (2) used in the prior art references is heavy in weight, that in turn increases weight of the whole assembly.
Hence, there is a need to develop a new design for the monotube shock absorber that is light in weight and easy to assemble with a low cost that overcomes the above mentioned drawbacks of the prior art.

Objects of the invention

An object of the present invention is to facilitate an easy assembling of a twin cylinder monotube shock absorber.

Another object of the present invention is to reduce a weight of the twin cylinder monotube shock absorber.

Summary of the invention

Accordingly, the present invention provides a twin cylinder monotube shock absorber. The twin cylinder monotube shock absorber comprises a housing, an outer tube and an inner tube. The housing, the outer tube and the inner tube are made of low carbon steel.

The housing includes a gas chamber enclosed therein. The gas chamber includes bellow assembly parts positioned therein. The outer tube includes a bottom portion fitted to the housing. The outer tube is seam welded to the housing. The outer tube is wrapped on another end of the housing. The outer tube is subjected to any one of spinning and bending for being wrapped on the other end of the housing.

The inner tube is enclosed in the outer tube. The inner tube includes hydraulic fluid like oil filled therein. The inner tube is a pressure tube and includes a piston rod assembly positioned therein for moving in any one of upward and downward directions in response to bumps in the road. The housing, the outer tube and the inner tube form a twin-cylinder type design of the monotube shock absorber.

Brief description of the drawings

The objectives and advantages of the present invention will become apparent from the following description read in accordance with the accompanying drawings wherein,
Figure 1 shows a schematic diagram of a monotube shock absorber, in accordance with a prior art; and

Figure 2 shows a schematic diagram of a twin cylinder monotube shock absorber, in accordance with the present invention.

Detailed description of the invention

The foregoing objects of the invention are accomplished and the problems and shortcomings associated with the prior art techniques and approaches are overcome by the present invention as described below in the preferred embodiment.

The present invention provides a new design of a monotube shock absorber. The monotube shock absorber includes two tubes as compared to a single pressure tube of the prior art monotube shock absorber. The monotube shock absorber designed in accordance with the present invention is applicable for a canister type hydro-pneumatic shock absorber.

The present invention is illustrated with reference to the accompanying drawings, throughout which reference numbers indicate corresponding parts in the various figures. These reference numbers are shown in bracket in the following description.

Referring to figure 2, a twin cylinder monotube shock absorber (100) (hereinafter referred as “the shock absorber (100)”) in accordance with the present invention is shown. The shock absorber (100) is characterized in a way that the shock absorber (100) has twin cylinder type monotube design. The shock absorber (100) comprises a housing (50), an outer tube (40) and an inner tube (30). The housing (50), the outer tube (40) and the inner tube (30) form a twin-cylinder type design of the monotube shock absorber (100). In an embodiment, the housing (50), the outer tube (40) and the inner tube (30) are made of low carbon steel.

The housing (50) is adapted for mounting the shock absorber (100) onto a vehicle (not shown). The housing (50) includes a gas chamber (60) enclosed therein. The gas chamber (60) includes bellow assembly parts (not shown) positioned therein.

The outer tube (40) is held in a position by the housing (50) and a rod guide (not shown). The outer tube (40) through a bottom portion (not numbered) thereof is fitted to the housing (50). In other words, the housing (50) is located at the bottom portion of the outer tube (40). Specifically, the outer tube (40) is seam welded to the housing (50) and is wrapped on another end of the housing (50) for a closure of the shock absorber (100). In an embodiment, the outer tube (40) is subjected to spinning / bending for being wrapped on another end of the housing (50). The outer tube (40) acts as a shell for the inner tube (30).

The inner tube (30) is a pressure tube enclosed in the outer tube (40). The inner tube (30) includes hydraulic fluid like oil filled therein. The inner tube (30) contains a piston rod assembly (not numbered). The piston rod assembly is adapted for moving in any one of upward and downward directions in response to bumps in the road.

Advantages of the invention

1. The shock absorber (100) is easy to assemble.
2. The shock absorber (100) is light in weight.
3. The shock absorber (100) is manufactured with a low cost.

The foregoing objects of the invention are accomplished and the problems and shortcomings associated with prior art techniques and approaches are overcome by the present invention described in the present embodiment. Detailed descriptions of the preferred embodiment are provided herein; however, it is to be understood that the present invention may be embodied in various forms. Therefore, specific details disclosed herein are not to be interpreted as limiting, but rather as a basis for the claims and as a representative basis for teaching one skilled in the art to employ the present invention in virtually any appropriately detailed system, structure, or matter. The embodiments of the invention as described above and the methods disclosed herein will suggest further modification and alterations to those skilled in the art. Such further modifications and alterations may be made without departing from the spirit and scope of the invention.
,CLAIMS:We claim:

1. A twin cylinder monotube shock absorber (100) comprising:
• a housing (50) having a gas chamber (60) enclosed therein, the gas
chamber (60) having bellow assembly parts positioned therein;
• an outer tube (40) having a bottom portion fitted to the housing (50), the
outer tube (40) being wrapped on another end of the housing; and
• an inner tube (30) enclosed in the outer tube (40), the inner tube (30)
having hydraulic fluid like oil filled therein, the inner tube (30) being a pressure tube having a piston rod assembly positioned therein for moving in any one of upward and downward directions in response to bumps in the road, the inner tube (30), the outer tube (40) and the housing (50) form a twin-cylinder type design of the monotube shock absorber (100).

2. The twin cylinder monotube shock absorber (100) as claimed in claim 1, wherein the housing (50), the outer tube (40) and the inner tube (30) are made of low carbon steel.

3. The twin cylinder monotube shock absorber (100) as claimed in claim 1, wherein the outer tube (40) is seam welded to the housing (50).

4. The twin cylinder monotube shock absorber (100) as claimed in claim 1, wherein the outer tube (40) is subjected to any one of spinning and bending for being wrapped on the other end of the housing (50).