TUBULAR CASE WITH FLANGE AND METHOD OF MANUFACTURING THE SAME

Description

BACKGROUND OF THE INVENTION

1. Field of the Invention

The present invention relates to a cold forging process technology, in particular to a one-step forming manufacturing using cold forging technology, which reduces the destruction of the mechanical properties of the product caused by multi-process forging, improves the durability and safety of the product, and further reduces industrial waste and production costs thereof. A penetrated through hole of the tubular case is arranged inside the tube head and the tube body. The said tubular case with a flange of the step of the manufacturing method comprises of: placing a blank material into the mold cavity for forming a tubular case.

2. Description of the Prior Art

As for a mechanical transmission structure, the utilization of a spindle and a spindle housing to transmit rotational power to drive various tools has become a universal design common to the industry. Since these components must be maintained in high speed motion for a long time, the mechanical properties thereof must be maintained in a good condition. Changes in mechanical properties caused by the production and working thereof must be considered, in addition to the selection of suitable manufacturing materials, whereby a power transmission component with sufficient strength can be obtained.

Taking the structure of a lawn mower as an example, the aforementioned spindle and spindle housing are used to transmit power from the engine to the lawn mower blades to perform lawn-mowing operations. Among them, the spindle housing is mostly a finished spindle housing accomplished by obtaining a crude embryo using a die cast working manner, followed by a secondary working. However, the utilization of multi-process working will inevitably generate more industrial waste and increase costs and production time. And, the more working steps there are, the more difficult it will be to manage quality, which will lower the production yield of the product and further lead to an increase in costs thereof. Even more, the multi-process working is prone to reducing the mechanical properties of the spindle housing, such as Ultimate Tensile Strength (UTS), Yield Strength (YS), Brinell hardness, etc., due to issues such as thermal effects and working hardening, thus resulting in potential safety issues in the product.

SUMMARY OF THE INVENTION

It is an object of the present invention to provide a manufacturing method, which adopts the cold forging technology for one-step forming manufacturing of the tubular case structures to reduce the destruction of the mechanical properties of the product caused by multi-process forging working, and thus improving the durability and safety of the product.

Another object of the present invention is to reduce the steps of forging working, to increase the quality and precision of the product, and to further reduce the production costs thereof.

Still another object of the present invention is to drastically reduce the production of industrial waste, to keep the work environment neat, and also to reduce the time and costs of the subsequent disposal of the industrial waste.

The technical solution of the present invention is to provide a tubular case with a flange, comprising a tube head which is connected backward to a tube body. A flange extending outward is arranged at the connection between the tube head. pressurizing and cold forging the blank material, which causes the blank material to fill the entire mold cavity to form the tubular case with a tube head, a flange, and a tube body from top to bottom, with a space being arranged inside the tube head and the tube body; and punching a hole inside the tubular case to form a through hole penetrating through the space inside the tube head and the tube body.

BRIEF DESCRIPTION OF THE DRAWINGS

FIG. 1 is a perspective view of a tubular case with a flange according to the present invention;

FIG. 2 is a front structure diagram of the tubular case;

FIG. 3 is a schematic diagram of the manufacturing step of placing a pie-shaped blank material into a mold cavity according to the present invention;

FIG. 4 is a schematic diagram of the manufacturing steps for forming the tubular case by cold forging pressurizing according to the present invention;

FIG. 5 is a schematic diagram of a manufacturing step for placing the tubular case into a hole punching mold to position according to the present invention;

FIG. 6 is a schematic diagram of a manufacturing step for implementing hole punching according to the present invention.

DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS

Referring to FIG. 1 and 2, a tubular case 100 with a flange according to the present invention is shown. The tubular case 100 mainly comprises a tube head 110 which is connected backward to a tube body 120. A flange 130 extending outward is arranged at the connection between the tube head 110 and the tube body 120, and a penetrated through hole 140 is arranged inside the tube head 110 and the tube body 120, which causes the tubular case 100 to be fixed to the lawn mower by the flange 130 and allows the spindle of a lawn mower to be passed through the through hole 140 to perform the operation of transmitting power.

In conventional process, it is usually necessary to take a piece of rod-shaped blank material, the rod-shaped blank material being pressurized from both ends to initially generated a concave hole inside the rod-shaped blank material, the rod-shaped blank material being penetrated through by multiple consecutive pressurizations, and then the rod-shaped blank material being pressurized on its outside to further generate a thickened protrusion, which are therefore a complicated process, and the finished product being prone to errors, thus affecting the use of the product and existing safety issues.

According to the manufacturing method of the present invention, as shown in FIG. 3 to 6, a well-designed machine table 200 with a mold cavity 300 arranged therein for placing a pie-shaped blank material 400 is involved. The pie-shaped blank material 400 according to this embodiment is made of 6061 aluminum alloy material, but not limited thereto. A pressurizing mold block 210 is movably entered deep into the mold cavity 300. The pie-shaped blank material 400 is pressurized by a cold forging process to fill the entire mold cavity 300, and thus a desired tubular case 100 is accomplished.

As further described below, the mold cavity 300 is in an appearance like the tubular case 100, wherein a placing opening 310 with the largest outer diameter is arranged above the mold cavity 300. The placing opening 310 with a depth greater than the thickness of the flange 130 is used to accommodate the pie-shaped blank material 400 which will be cold forged to form the flange 130 portion of the tubular case 100. A tube body groove 320 with a smaller outer diameter is arranged to extend downward from the bottom of the placing opening 310. The horizontal cross section of the tube body groove 320 is in the shape of an annular missing groove, which is used to generate a tube body 120 portion of the tubular case 100. A protrusion 220 entering deep into and tightly fitting into the placing opening 310 of the mold cavity 300 is arranged at the front end of the pressurizing mold block 210. The distance of the end face of the protrusion 220 from the placing opening 310 is equal to the thickness of the flange 130. A tube head groove 330 is arranged on the end surface of the protrusion 220, and the horizontal cross section of the tube head groove 330 is also in the shape of an annular missing groove for generating the tube head 110 portion of the tubular case 100.

As shown in FIG. 3 to 6 and described above, the steps of the cold forging working manner according to the present invention comprise:

1. placing the calculated appropriate size pie-shaped blank material 400 into the placement opening 310;

2. driving the pressurizing mold block 210 to enable the protrusion 220 to enter deep into the placing opening 310 of the mold cavity 300, with the pie-shaped blank material 400 being consecutively pressurized to first fill the placing opening 310, and then to further fill the tube head groove 330 upward and the tube body groove 320 downward respectively, thus accomplishing the appearance of the tubular case 100;

3. placing the tubular case 100 into a hole punching mold 500 to position and aligning the punching head 510 with the center of the tubular case 100;

4. forming a through hole 140, by which the space inside the tube head 110 and the space inside the tube body 120 is penetrated through, by punching a hole with a punching head.

The aforementioned processed tubular shell 100 may be further heat treated to restore the physical strength lost during the cold forging process.

By way of the above-mentioned cold forging working technology, the advantages of the present invention can be clearly seen as follows:

1. The one-step cold forging forming is adopted by the present invention, so the formed tubular case 100 does not need to be cleaned up flashes or disposed of waste, and thus dramatically simplifying the manufacturing process;

2. According to the present invention, no heat distortion or heat loss is generated, so the size of the pie-shaped blank material 400 can be accurately calculated, and the product quality can be accurately maintained for each cold forging;

3. According to the present invention, a material is in advance designed as a pie-shaped blank material 400 which forms a flange 130 portion with the largest volume in precedence, and the periphery of the pie-shaped blank material 400 is near the edge of the placing opening 310, so that the working time and power loss could be reduced;

4. According to the present invention, it is easier for the mold cavity 300 to be filled throughout with the pie-shaped blank material 400 sequentially, compared to the traditional manner of forming the tube before thickening the protruding region, which not only improves the quality of the product, but also increases the safety of the use of the product, without disadvantages such as weakness or breakage at the product connection.

In addition, as shown in FIGS. 1 and 2, for the purposes of matching different configuration requirements, different numbers and sizes of screw holes 150 may be arranged in the flange 130 of the tubular case 100, or other rust-proofing treatments may be carried out, etc., which do not belong to the characteristics of the present invention, and therefore will not be elaborated in detail herein.

While the preferred embodiments of the invention have been set forth for the purposes of disclosure, modifications of the disclosed embodiments of the invention as well as other embodiments thereof may occur to those skilled in the art. Accordingly, the appended claims are intended to cover all embodiments which do not depart from the spirit and scope of the invention.