FIELD OF THE INVENTION
The present invention relates to a guardrail assembled by stamping and an apparatus for assembly of the guardrail.
DESCRIPTION OF THE PRIOR ART
Current well-known guardrails are formed of iron, aluminum, stainless steel and other materials by combination welding. Combination welded guardrails are complex and expensive to manufacture, and fumes produced from combination welding will pollute the environment and harm the health of personnel. In addition, such welding processes may deform tubes or pipes and cause rusting and other defects, in particular severe peeling of surface paint coatings. These can lead to high cost of subsequent maintenance and services and necessitate subsequent touch-up painting or other secondary finishing.
Most existing guardrails rely on manual assembly, which involves placing in parallel at least two rails with holes drilled therein being in alignment and manually inserting each baluster in respective holes. This approach is labor-intensive and labor-inefficient. After the insertion, a welding machine is used to form welded joints along the insertion edges, followed by a final spray painting process. Since the welding joints are prone to the presence of gaps, the Faraday shielding effect is inevitable during the electrostatic spray painting. Consequently, local absence of the protective paint may occur, leading to inferior overall anti-corrosion performance of such guardrails.
SUMMARY OF THE INVENTION
Problem to be Solved
In view of the above-discussed problems, the present invention provides a guardrail assembled by stamping. The assembly can be accomplished with the use of an apparatus instead of welding, thus avoiding the Faraday shielding effect that may arise during an electrostatic spray painting process and resulting in improved anti-corrosion performance.
Solutions to Problem
Technical Solutions
To this end, the present invention provides a guardrail assembled by stamping structured as described below. It includes two rails, which are spaced from each other and disposed horizontally, and balusters, which are spaced from one another and disposed vertically. The rails are provided thereon with a plurality of spaced insertion holes. The insertion holes in the upper and lower adjacent rails are arranged in vertical alignment. The insertion holes blind holes arranged to face inwards. Its structure is characterized in that: the plurality of balusters are inserted by an apparatus into the aligned insertion holes respectively, allowing insertion of the plurality of balusters into the rails; portions extending outwardly from walls of the insertion holes form abutment portions; after end portions of the balusters are extended into the insertion holes, the end portions of the balusters are bent outwardly by a stamping means in the apparatus to form rolled edge rims; and the rolled edge rims abut against the abutment portion, achieving secure attachment of the balusters to the rails.
The balusters may be fabricated from round tubes or square tubes, wherein the rolled edge rims are annular rims.
The balusters may be fabricated from round tubes or square tubes, wherein the rolled edge rims are each in the form of multiple bent pieces arranged into an annular pattern, which forms as a result of stamping by the stamping means.
The rails may be fabricated from square tubes, wherein the abutment portions are provided by inner walls of the square tubes.
An apparatus for assembly of the guardrail as defined above includes a rack mounted thereon with a mounting platform, the mounting platform provided thereon with baluster holding brackets for securing a plurality of parallel balusters, the mounting platform provided on one side thereof with a stamping platform, the stamping platform attached thereto with a transversely slideable lower base, the lower base driven by an approximating power mechanism to transversely slide, the lower base slidably attached thereto with a stamping stage driven by a stamping cylinder to transversely slide, the stamping stage attached thereto with a rail push plate, the stamping platform further provided thereon with a stamping means which is able to extend into a rail to stamp end portions of the balusters.
The stamping means may comprises a stamping base linked to the stamping stage, the stamping base attached thereto with a stamping rod and a push rod, which extend into a rail in parallel, the stamping rod driven by power provided by a left-hand insertion cylinder attached to the stamping base, the push rod driven by power provided by a right-hand insertion cylinder attached to the stamping base, the stamping rod provided thereon with a plurality of spaced stamping heads, the number and locations of stamping heads corresponding to the number and locations of balusters.
The mounting platform may be provided thereon with a compression means, the compression means comprising a compression frame attached to the mounting platform, the compression frame slidably attached thereto with a slidable frame capable of sliding up and down, the compression frame provided thereon with a compression cylinder capable of driving the slidable frame to slide up and down, the slidable frame provided at the bottom thereof with compression platens capable of abutting against the top of balusters, the compression platens provided thereon with a plurality of indentations capable of receiving upper portions of the balusters.
The stamping base, to which the stamping rod is attached, may be slidably attached thereto with a transversely slideable withdrawal base, to which the stamping rod and the left-hand insertion cylinder are both attached, wherein the stamping base is further provided thereon with a withdrawal cylinder for driving the withdrawal base to transversely slide.
The approximating power mechanism may comprise an approximating servo motor attached to the lower base, a power output shaft of the approximating servo motor provided thereon with an approximating lead screw, wherein a nut threaded engaged with the approximating lead screw is fixedly attached to the stamping platform.
The stamping heads may be provided on tapered surfaces thereof with a plurality of cutting edges performing cutting function of the end portions of balusters.
Benefits of the Invention
Benefits
Compared with the prior art, the above structure has the advantages as follows: portions extending outwardly from walls of the insertion holes form abutment portions, and end portions of balusters can be inserted into the insertion holes and then undergo a stamping process so as to be bent outwardly to form rolled edge rims abutting against the abutment portions, thereby securely attaching the balusters to the rails. This can achieve secure assembly without involving direct welding, avoiding the Faraday shielding effect that may arise during electrostatic spray painting and resulting in improved anti-corrosion performance.
In summary, the present invention provides the advantageous benefits of firm and secure assembly, convenient and fast assembly and good anti-corrosion performance.
BRIEF DESCRIPTION OF THE DRAWINGS
Description of the Drawings
FIG. 1 is a schematic diagram showing the structure of an embodiment of the present invention.
FIG. 2 is a schematic enlarged view of part A of FIG. 1.
FIG. 3 is a schematic diagram showing the structure of an embodiment of the present invention, showing balusters inserted in and assembled with rails.
FIG. 4 is a diagram showing a conventional guardrail being assembled;
FIG. 5 is a schematic diagram showing the structure of an embodiment of an apparatus according to the present invention;
FIG. 6 is a schematic top view of the embodiment of FIG. 5;
FIG. 7 is a schematic diagram showing the structure of a compression platen in the embodiment of FIG. 5.
FIG. 8 schematically illustrates assembly of the present invention using an apparatus.
DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS
Embodiments of the Invention
Specific embodiments of the present invention will be described in greater detail below with reference to the accompanying drawings.
Referring to FIG. 4, conventionally, a plurality of insertion holes are perforated in advance in rails placed on a platform, and balusters are manually inserted one by one into the insertion holes, achieving assembly of these components. Following the assembly, welded joints are formed at locations X as shown, which securely join the rails to the balusters so that they together form a guiderail. Since the balusters are sized very closely to the insertion holes (with a difference of ca. 0.5 mm), the insertion assembly process is highly inconvenient, labor-inefficient and labor-intensive. Moreover, the welded joints tend to suffer from the Faraday shielding effect, which can cause rusting, reduce the product's service life, or be otherwise problematic.
As shown in FIGS. 1 and 2, an embodiment of a guardrail assembled by stamping according to the present invention includes two rails 1, which are spaced at an interval and disposed horizontally, and balusters 2, which are spaced at intervals and disposed vertically. In this embodiment, the rails and the balusters are all fabricated from square tubes. The rails are each provided therein with a plurality of insertion holes 11, which are spaced apart and open vertically. The insertion holes in the upper rail are vertically aligned with the respective insertion holes in the lower rail. The insertion holes 11 may be inwardly open blind holes formed in opposing tube walls of the respective two square tubes, the plurality of balusters are inserted into the respective vertically aligned pairs of insertion holes and thereby assembled with the rails. Portions extending outwardly from walls of the insertion holes form abutment portions. In this embodiment, these abutment portions are provided by inner wall portions of the square tubes around the insertion holes, i.e., portions Y in FIG. 2. End portions of the balusters inserted through the insertion holes are subjected to a stamping process. As a result, these baluster end portions are bent outwardly and form rolled edge rims 21. The rolled edge rims abut against the abutment portions, securing the balusters to the rails. In this embodiment, the rolled edge rims are annular rims, which outer surfaces exactly push against the abutment portions of the square tubes (rails). This overcomes the problem of possible vertical displacement of the balusters and achieves rigid fixation of the balusters to the rails. This design does not require forming welded joints between the balusters and rails any longer, allowing assembly to be accomplished after outer walls of the square tube have been spray painted. This can avoid the Faraday shielding effect that may arise during electrostatic spray painting and enables the entire guardrail to have better anti-corrosion performance. Further, spray painting has the advantage of avoiding paint loss or uneven painting, and therefore the walls of the holes will also be coated with a uniform layer of paint, greatly enhancing the guardrail's anti-corrosion performance. Of course, it is also possible that electrostatic spray painting succeeds assembly. This can also allow the guardrail to have enhanced anti-corrosion performance.
Referring to FIG. 3, another embodiment of the present invention is illustrated, which is substantially of the same structure as the foregoing embodiment, except that the balusters are fabricated from round tubes and that the rolled edge rims each consist of multiple bent pieces in the form of an annular pattern, which result from a stamping operation carried out by a stamping means. That is, after the balusters are inserted into the rails, a stamping means in an apparatus is used to expand each round tube outwards and tear it apart, forming the bent pieces in the form of an annular pattern. These bent pieces also abut against the aforementioned abutment portions, fixing the balusters to the rails. Of course, other embodiments are also possible. For example, when the balusters are fabricated from square tubes, end portions of them may be likewise stamped using a stamping means into the above-discussed bent pieces. Further description of these embodiments is unnecessary and omitted herein.
Referring to FIGS. 5 and 6, the present invention provides an apparatus used to assemble a guardrail. It includes a rack 100, which may be an integral structure, or may be composed of separate parts. It serves as a support for other components and is not limited to being of the structured as shown. For ease of description, a transverse direction of the apparatus is defined as the left-to-right direction in the orientation of FIG. 5, and a longitudinal direction of the apparatus for assembly of the guardrail is defined as the direction perpendicular to the plane of FIG. 5. A mounting platform 101 is mounted on the rack 100, and is provided thereon with baluster holding brackets 102 for retaining a plurality of parallel balusters. The balusters are retained on the baluster holding brackets so that its opposing end portions extend beyond periphery of the mounting platform. In this embodiment, the baluster holding brackets 102 are provided as pairs of clamping arms arranged on the mounting platform, and each baluster is clamped and retained jointly by at least two such pairs of clamping arms. A stamping platform 103 is disposed beside the mounting platform 101. A transversely slideable lower base 104 is attached to the stamping platform 103. The lower base 104 is driven by an approximating power mechanism to transversely side. The approximating power mechanism includes an approximating servo motor 105 attached to the lower base 104, and an approximating lead screw 106 is attached to a power output shaft of the approximating servo motor. A nut threadedly engaging the approximating lead screw is fixed to the stamping platform. The approximating servo motor 105 operates to rotate the approximating lead screw, causing the lower base to transversely slide. A stamping stage 109 is slidably attached to the lower base and is driven by a stamping cylinder 108 to transversely slide. A rail push plate 110 is attached to the stamping stage 109, and a rail is disposed on the rail push plate 110, with its insertion holes facing towards the mounting platform 101. The stamping platform 103 is further provided with a stamping means, which can be inserted into the rail to stamp end portions of balusters. The stamping means includes a stamping base 111 linked to the stamping stage. Here, by “linked”, it is intended to mean that the stamping base 111 can slide together with the stamping stage. Specifically, the stamping base is slidably attached to the stamping platform and coupled to the stamping stage through linking rods. A stamping rod 112 and a push rod 113, which can be inserted into the rail in parallel, are attached to the stamping base 111. The stamping rod 112 is driven by power provided by a left-hand insertion cylinder 114 on the stamping base 111, and the push rod 113 is driven by power provided by a right-hand insertion cylinder 115 on the stamping base 111. That is, the stamping rod 112 and the push rod 113 can separately slide longitudinally into the rail. In this embodiment, the stamping rod 112 and the push rod 113 are disposed on opposing sides of the stamping stage. This can facilitate arrangement and insertion. The stamping rod 112 is disposed closer to the insertion holes in the rail than the push rod. The stamping rod 112 is provided thereon with a plurality of spaced stamping heads 116. The number and locations of the stamping heads 116 correspond to the number and locations of balusters to be handled. The stamping rod is inserted into the rail so that the stamping heads are aligned with openings of the insertion holes. In this embodiment, production is conducted in a platform-based conveyance manner. That is, the mounting platform 101 is placed on conveyance rails, and two of the above-described stamping platforms are arranged on opposing sides of the mounting platform. When the mounting platform 101 reaches between the two stamping platforms, the stamping platforms simultaneously stamp opposing ends of balusters. That is, the opposing ends of each baluster are simultaneously connected to rails. Specifically, this may involve the steps as follows. Referring to FIG. 8, when the mounting platform 101 moves to a predetermined location, the approximating servo motors 105 operate to cause the lower bases to slide. As a result, rails on the stamping stages approach end portions of balusters on the mounting platform 101, and the baluster end portions are aligned with insertion holes in the rails. Once the alignment is attained, the stamping rods 112 and the push rods 113 extend into the rails in parallel, and the stamping cylinders 108 operate to insert the baluster end portions into the insertion holes in the rails. At the same time, under the pressure of the stamping heads, the baluster end portions are flared outwardly and finally form rolled edge rims 21 abutting against (abutment portions) of inner walls of the square tubes. Thus, the balusters are inserted in and assembled with the rails. As can be seen from the above description, according to the present invention, direct assembly can be accomplished without involving welding or another process. Therefore, high labor efficiency can be achieved, and the problem of rusting can be prevented.
Referring to FIGS. 5 to 7, in order to ensure stamping quality and avoid bending or bulging of the balusters, the mounting platform 101 is provided thereon with a compression means including a compression frame 117 attached to the mounting platform and a slidable frame 118 which is attached to the compression frame 117 so as to be slidable up and down. A compression cylinder 119 is mounted on the compression frame 117, which can drive the slidable frame 118 to slide up and down. The slidable frame 118 is provided at its bottom with compression platens 120 which can abut against the top of the balusters. A plurality of indentations are formed on the compression platens 120, upper portions of the balusters can be received in the indentations. Rubber pads are attached to walls of the indentations, which can prevent bulging or bending of the balusters. Moreover, in this embodiment, the slidable frame 118 has two compressing arms extending downwards, and the compression platens are attached to the bottom of the compressing arms. The compressing arms are aligned with the end portions of the baluster in order to better compress the balusters. Further, in order to facilitate withdrawal of the stamping rods and the stamping heads, in this embodiment, transversely slideable withdrawal bases 121 are slidably attached to the stamping bases 111, to which the stamping rods 112 are attached, and the aforementioned stamping rods 112 and left-hand insertion cylinders 114 are all attached to the withdrawal bases 121. The stamping bases are further provided thereon with withdrawal cylinders 122 for driving the withdrawal bases to transversely slide. After the above-described stamping action is completed, the push rods 113 are first driven by power provided by the right-hand insertion cylinders 115 to retract out of the rails, and the withdrawal cylinders 122 operate to move the stamping rods 112 away from the insertion holes to bring the stamping heads completely out of the baluster end portions. Subsequently, the left-hand insertion cylinders 114 operate to withdraw the stamping rods and the stamping heads. With combined reference to the figures, in this embodiment, the aforementioned stamping heads are tapered stamping heads capable of expanding square and round tubes and thereby forming the aforementioned rolled edge rims. Of course, multiple cutting edges may be provided on tapered surfaces of the stamping heads, which can cut end portions of balusters during stamping and expansion into the aforementioned bent pieces in the form of annular patterns. Further detailed description thereof is unnecessary and omitted herein. As shown, in this embodiment, the aforementioned stamping rods 112 are in the form of simple rods. Of course, in order to prevent misalignment of the baluster end portions with the insertion holes, during operation of the approximating power mechanisms for alignment, the aforementioned tapered stamping heads may provide guidance and location. In this case, the stamping rods may be in the form of resilient posts each composed of several sections connected together end-to-end by stiff springs. This structure can not only provide effective support, but also allows the stamping heads to properly guide the baluster end portions, ensuring stamping quality and secure attachment of the balusters to the rails.
Referring to FIGS. 5 to 7, in order to facilitate location and increase stamping accuracy, resilient means 125 are provided on sides of the mounting platform. Each resilient means includes a resilient plate and springs attached to the resilient plate. Inner ends of the springs are attached to the mounting platform. During stamping, peripheral edges of the stamping stages abut against the resilient plates, and the springs are compressed, providing good cushioning which avoids rigid collisions of the stamping stages with the mounting platform.
Although specific configurations of the present invention have been described above, the present invention is not limited to the foregoing embodiments. Those skilled in the art would recognize that any and all equivalent structural variations and component substitutions based on the teachings disclosed herein fall within the scope of the present invention.
INDUSTRIAL UTILITY
Portions extending outwardly from walls of the insertion holes form abutment portions, and end portions of balusters can be inserted into the insertion holes and then undergo a stamping process so as to be bent outwardly to form rolled edge rims abutting against the abutment portions, thereby securely attaching the balusters to the rails. This can achieve secure assembly without involving direct welding, avoiding the Faraday shielding effect that may arise during electrostatic spray painting and resulting in improved anti-corrosion performance.
The present invention provides the advantageous benefits of firm and secure assembly, convenient and fast assembly and good anti-corrosion performance.
Patent Application
20240318459
