DESC:SHOCK ABSORBER HOUSING AND CONSTRUCTION METHOD THEREOF

Field of the invention

The present invention generally relates to a field of suspension assembly used in automobiles and more particularly, to a shock absorber housing and a construction method thereof.

Background of the invention

Shock absorbers are fitted in vehicles for dampening shocks caused by uneven road conditions. The shock absorbers are available in three types, specifically, twin-tube shock absorber, monotube shock absorber and canister attached monotube shock absorber. In the canister attached monotube shock absorber, canister serves as a reservoir for the oil and pressurized gas like nitrogen. The pressurized nitrogen gas inside the canister prevents foaming of the oil inside the shock absorber caused by heavy use and riding conditions.

Canisters are joined in various ways to a main housing of the shock absorber. In a prior art, a complete canister is available in aluminum part. The aluminum part is manufactured by a die casting process. However, a more part weight is required in order to maintain minimum wall thickness for the die casting process. Also, it costs high due to use of aluminum material and secondary machining process.

Some of the shock absorbers in the prior art includes a housing comprising of a canister and a mounting. The canister is made of aluminum part with threading for canister fastening. The canister is fastened to the mounting by a thread joint. The mounting consists of a tube with threading to be fastened with the canister. However, a wall thickness of the canister should be more for threading. A sealing mechanism is required to avoid oil leakage through the thread joint. Also, the joining mechanism is costly due to two threading operations, one in canister and other in the housing.

Hence, there is a need to develop a method for joining a canister in a shock absorber properly and cost-effectively to overcome the drawbacks mentioned in the prior art.

Objects of the invention

An object of the present invention is to assemble a canister with a shock absorber in a suitable and easy way.

Another object of the present invention is to prevent a leakage of any hydraulic fluid through the canister.

Summary of the invention

Accordingly, in one aspect, the present invention provides a shock absorber housing. The shock absorber housing is made of low carbon steel. The housing comprises a canister and a mounting. The canister includes a gas chamber and bellow assembly parts configured therein. The canister is a steel tube.

The mounting is joined to the canister by a laser welding method. The mounting is a steel forged part. The mounting includes a pressure tube and canister assembly parts configured therein to allow oil flow there between.

In another aspect, the present invention provides a construction method of a shock absorber housing. The construction method comprises holding the mounting and the canister in a welding fixture and depositing filler material like low carbon steel in an area of interface by using laser as a heat providing medium for heating the filler material to a temperature of about 1500 °C at atmospheric pressure to melt the filler material for fusing together the mounting the canister.

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,
Figures 1-2 show a schematic diagram of a housing of a 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 shock absorber housing and a construction method thereof. The housing includes a mounting and a canister. The mounting and the canister are joined by a welding process. The welding process prevents leakage of any hydraulic fluid through the canister.

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 figures 1 and 2, in an aspect, a shock absorber housing (50) (herein after ‘the housing (50)’) in accordance with the present invention is shown. Specifically, the shock absorber (not shown) is a canister type hydro-pneumatic shock absorber. The housing (50) comprises a mounting (20) and a canister (40). In an embodiment, the housing (50) is made of low carbon steel.

The mounting (20) is a vehicle mounting component. The mounting (20) includes a pressure tube (not shown) and canister assembly parts (not shown) configured therein. The mounting (20) facilitates the oil flow from the pressure tube to the canister (40) and vice versa. In an embodiment, the mounting (20) is a steel forged part.

The canister (40) includes a gas chamber (not shown) and bellow assembly parts (not shown) configured therein. In an embodiment, the canister (40) is a steel tube. The housing (50) is characterized in that the mounting (20) and the canister (40) are joined by a welding method, preferably a laser welding method.

In another aspect, a construction method (herein after ‘the method’) of the housing (50) is illustrated in accordance with the present invention. In an embodiment, the method is a welding method. In a preferred embodiment, the method is a laser welding method. The method comprises holding the mounting (20) and the canister (40) in a welding fixture (not shown) and depositing filler material in the area of interface by using laser as a heat providing medium. In an embodiment, the filler material is a low carbon steel heating that is heated to a temperature of about 1500 °C at atmospheric pressure to melt the filler material for fusing together the mounting (20) and the canister (40).

Advantages of the invention

1. The mounting (20) and the canister (40) are joined by easy assembling process in the housing (50).
2. The housing (50) becomes a light weight as compared to the prior art references.
3. The manufacturing cost of the housing (50) is low.
4. The housing (50) has improved load carrying capacity as compared to prior art aluminum housing.
5. The housing (50) is suitable for various surface finish processes such as electroplating, powder coating, painting and like.

The foregoing descriptions of specific embodiments of the present invention have been presented for purposes of illustration and description. They are not intended to be exhaustive or to limit the present invention to the precise forms disclosed, and obviously many modifications and variations are possible in light of the above teaching. The embodiments were chosen and described in order to best explain the principles of the present invention and its practical application, and to thereby enable others skilled in the art to best utilize the present invention and various embodiments with various modifications as are suited to the particular use contemplated. It is understood that various omissions and substitutions of equivalents are contemplated as circumstances may suggest or render expedient, but such omissions and substitutions are intended to cover the application or implementation without departing from the spirit or scope of the claims of the present invention ,CLAIMS:1. A shock absorber housing (50) comprising:
• a canister (40) having a gas chamber and bellow assembly parts configured therein; and
• a mounting (20) joined to the canister (40), the mounting (20) having a pressure tube and canister assembly parts configured therein to allow oil flow there between, the shock absorber housing (50) being characterized in that the mounting (20) and the canister (40) being joined by a laser welding method.

2. The shock absorber housing (50) as claimed in claim 1 is made of low carbon steel.

3. The shock absorber housing (50) as claimed in claim 1, wherein the mounting (20) is a steel forged part.

4. The shock absorber housing (50) as claimed in claim 1, wherein the canister (40) is a steel tube.

5. A construction method of a shock absorber housing (50), the construction method comprising:
• holding the mounting (20) and the canister (40) in a welding fixture; and
• depositing filler material in an area of interface by using laser as a heat providing medium to melt the filler material for fusing together the mounting (20) the canister (40).

6. The construction method as claimed in claim1, wherein the filler material is heated to a temperature of about 1500 °C at atmospheric pressure.
7. The construction method as claimed in claim1, wherein the filler material is low carbon steel.