JP6909586B2 - Manufacturing method of steel pipe for frame, frame member, frame for bathroom unit installation - Google Patents

Description

The present invention relates to a method for manufacturing a frame steel pipe used for a bathroom unit installation frame that supports a bathroom unit to be installed in a building, and a frame member and a bathroom unit installation frame.

Residential bathroom units, so-called unit baths, are generally installed on the base of a bathroom via a bathroom unit installation frame (hereinafter referred to as "frame") formed by joining square steel pipes. As shown in FIG. 1, the frame is composed of a horizontal member made of a square steel pipe and a vertical member joined by welding or bolts and nuts, but it is necessary to adjust the height according to the height and unevenness of the base of the installation location. Therefore, as shown in FIG. 2, the structure is such that bolts are screwed into multiple places on the lower surface of the frame from below, and the head of the bolt is grounded to the base, and the height can be adjusted by changing the penetration length of the bolt. Is going.

Further, due to the structure of the frame, a particularly large load is often applied to a place where a vertical member is used, so a bolt is attached to the lower end of the vertical member to ground the vertical member at such a place. As shown in FIGS. 3 and 4, the member to which the bolt is attached (hereinafter referred to as “frame member”) has a bolt hole in the opening of the square steel pipe for the frame member (hereinafter referred to as “frame material”). A structure is generally used in which a provided steel plate is welded or screwed to close it, and a bolt is inserted and screwed into the bolt hole.
Photograph of a conventional frame material with bolt holes manufactured by the applicant

However, according to the conventional technique, in the manufacturing process of the entire frame, a step of welding or screwing a steel plate to the frame material is required, which has been a factor of increasing the manufacturing cost. Further, a female screw can be provided in the bolt hole only for the thickness of the steel plate, and the bolt has a shape in which the frame member is supported by only a small part of the extension of the male screw. In the bolt mounting portion, it is necessary to secure sufficient strength so that when an uneven load is applied to the frame, the bolt tilts off the axis of the frame member and the grounding is insufficient. However, in the conventional technique in which the frame material is supported by the bolt only through the thickness of the steel plate, there is a limit in improving the strength of the bolt mounting portion due to the structure. Further, since the wall thickness of the steel pipe used for the frame member is generally about 1 mm, there is a limit to the improvement of the durability of the welding of the steel plate and the screwed portion. Furthermore, since the height of the frame is adjusted by rotating the male screw of the bolt that meshes with the female screw of the steel plate, the male screw is required to have a tooth height sufficient to mesh with the female screw, and the bolt is at least M16. Those of the above size are needed.

In view of this problem, the present invention allows the height of the frame to be adjusted by attaching bolts with sufficient strength by processing the shape of the square steel pipe itself without welding or screwing a separate member such as a steel plate. An object of the present invention is to provide a frame member and a frame for installing a bathroom unit, and to provide a manufacturing method for manufacturing a frame member by processing a square steel pipe into a steel pipe for a frame at low cost.

In order to solve the above problems, the invention according to claim 1 is a method for manufacturing a steel pipe for a frame, in which a first step of cutting a square steel pipe to a required length and one end of the cut square steel pipe are cut. The second step of forming into a cylindrical shape, the third step of squeezing the cylindrical portion and forming into a substantially conical shape having a cylindrical portion coaxial with the square steel pipe at the apex, and a female screw on the inner surface of the cylindrical portion. It consists of a fourth step of forming, and the molding of the cylindrical portion of the steel pipe in the third step is a process of inserting the cylindrical portion into a mold having a conical cavity with an open apex and pressing the cylinder portion. It is characterized by repeating using a plurality of molds in which is gradually reduced.

The invention according to claim 2 is a frame member including the steel pipe for a frame according to claim 1 and a bolt having a male screw that can be screwed into the female screw.

The invention according to claim 3 is a height-adjustable bathroom unit installation frame, characterized in that the frame member according to claim 2 is used as the grounding member.

According to the frame member according to claim 2, a separate member such as a steel plate or a mounting bracket thereof is not required, and bolts can be screwed directly into the frame material, so that the number of parts can be reduced and the frame assembly process can be performed. Cost reduction is possible by simplification. Further, for the bolt holes to be screwed with the bolts, female screws can be provided for the length of the cylindrical portion, so that the screwing extension between the bolts and the bolt holes can be sufficiently secured, and the mounting strength of the bolts can be improved. However, bolts with a relatively small screw pitch and thread height can also be applied.

Among the frame members of the frame for installing the bathroom unit, the vertical member for grounding is used for the part that supports a large load, including the part that supports the bathtub that fills with hot water and increases the weight when bathing. Improving the bolt mounting strength to the frame contributes to improving the durability of the entire frame.

Further, in order to firmly screw a bolt to one end of a square steel pipe without using a separate member, it is necessary to form a bolt hole of sufficient length with a female screw on the inner surface at one end of the square steel pipe. .. In the present invention, a square steel pipe is once formed into a cylindrical shape, and then the cylindrical portion is squeezed into a substantially conical shape, and the apex is formed into a coaxial cylindrical portion to integrally and continuously form a bolt hole. do. Therefore, in the process of squeezing, the wall thickness of the cylinder gradually increases toward the apex of the substantially conical shape, and the wall thickness of the coaxial cylindrical portion formed at the tip becomes the thickest. As a result, bolts having a smaller screw thread pitch and height can be applied as compared with the case where screw holes are provided in a steel plate as in the prior art.

Furthermore, per the molding frame steel pipe, when the cylindrical portion of the angular steel pipe to be molded in a single compression, but which may cause cracking and deformation pipe wall, the production of frames for steel pipes according to claim 1 According to the method , the yield is improved by performing the molding step by step using a plurality of molds whose sizes are gradually reduced.

Since the frame member according to claim 2 of the present invention does not require a separate member such as a steel plate for providing bolt holes, the number of parts is reduced and the manufacturing process is simplified in the manufacture of the frame for installing the bathroom unit. It has the effect of reducing costs. In addition, the bolt holes are integrally formed by molding one end of the steel pipe of the frame member, and the screw extension between the bolt and the bolt hole can be secured longer than in the conventional technology, so that the structural strength of the bolt mounting portion itself is only increased. In addition, the bolt mounting strength itself can be improved, and the durability of the bathroom unit installation frame can be improved. Further, according to the method for manufacturing a frame steel pipe according to claim 1 of the present invention, the yield when forming a square steel pipe into a frame steel pipe is improved.

Hereinafter, the frame member according to the present invention and the embodiment of the method for manufacturing the frame material will be described with reference to the drawings.

FIG. 5 is a perspective view showing the configuration of an embodiment of the frame member according to the present invention. The frame member A is composed of a frame material 1 and a bolt B, and the frame material 1 is a coaxial cylinder in which one end of a square steel pipe 10 forms a substantially conical portion 11 and a female screw 13 is provided on the inner surface at the tip thereof. It has a part 12. Since the male screw 14 of the bolt B meshes over the entire length of the female screw 13 of the cylindrical portion 12, there is no risk of the tooth slipping even if a bolt having a small screw height is used, and a bolt having a size of at least M10 or more. If so, it becomes applicable. FIG. 6 is a photograph of a prototype of the frame member A in a state where the bolt B is screwed, and FIG. 7 is an enlarged photograph of one end of the frame material 1 in a state without the bolt B. The frame material 1 in the photograph is provided by welding a metal fitting for joining a horizontal member (not shown) to the other end of the square steel pipe 10. A frame for installing a bathroom unit is formed by joining horizontal members here with bolts or by welding the other end to other horizontal members.

8 to 11 are process diagrams showing a method of manufacturing the frame material 1 of the frame member A. In the first step, as shown in FIG. 8, the square steel pipe is cut to a required length. In the second step, as shown in FIG. 9, one end of the square steel pipe 10 is formed into a cylindrical shape by a pipe drawing machine (not shown). In the third step, the cylindrical portion of the square steel pipe 10 is inserted into the die 2 having the conical cavity 20 having an open tip provided in the pipe squeezing machine and squeezed, and the die 2 is stepped by the cavity 20. By repeating this process a plurality of times, the shape is changed to a smaller one, and the shape is formed into a substantially conical shape having a cylindrical portion 12 at the tip. In the process of repeating this step, the wall thickness of the frame material 1 becomes thicker toward the tip end. In the fourth step, after the tip of the cylindrical portion 12 is prepared, the inner surface thereof is threaded to form the female screw 13. Since the total length of the frame material 1 is increased by squeezing the cylindrical portion, the length is increased in the first step in order to form the frame material 1 having a required length. It is desirable to set the length of the square steel pipe to be cut in consideration of.

Although the embodiment of the method for manufacturing a frame member and a steel pipe for a frame according to the present invention has been described above, the present invention is not limited to the above embodiment, and can be improved or improved within the scope of the technical idea of the present invention. Modifications are possible and they shall fall within the technical scope of the invention.

The frame member and the method for manufacturing the frame material according to the present invention are not only applicable to the frame member of the frame for installing the bathroom unit, but also various structures and temporary installations that require delicate height adjustment at the ground contact point. It can be applied to a wide range of fields such as objects or frames for various equipment. Further, it can be applied not only to a vertical member for grounding but also to a case where a horizontal member is fixed to a structure or the like.

It is a reference photograph which shows the structure of a bathroom unit. It is a reference photograph which shows the structure of the frame for installing a bathroom unit. It is a reference photograph of the frame material which concerns on the prior art. It is a reference photograph which enlarged the bolt attachment part of the frame material which concerns on the prior art. It is a perspective view of the frame member which concerns on embodiment. It is a photograph of the frame member according to the embodiment. It is an enlarged photograph of the bolt attachment part of the frame material which concerns on embodiment. It is a perspective view and cross-sectional view which shows the 1st process of frame material molding. It is a perspective view and cross-sectional view which shows the 2nd process of frame material molding. It is a perspective view and cross-sectional view which shows the 3rd process of frame material molding. It is a perspective view and sectional drawing which shows the 4th process of frame material molding. It is a schematic diagram which shows the detailed processing process of the 3rd process of frame material molding.

BT Bathtub BF Bathroom floor HF Horizontal member VF Vertical member A Frame member B Bolt F frame 1 Frame material 10 Square steel pipe 11 Approximately conical part 12 Cylindrical part 13 Female screw 14 Male screw 2 Mold 20 Cavity

Claims (3)

The first step of cutting a square steel pipe to a required length, the second step of forming one end of the cut square steel pipe into a cylindrical shape, and the squeezing of the cylindrical portion to apex the cylindrical portion coaxial with the square steel pipe. It consists of a third step of forming into a substantially conical shape and a fourth step of forming a female screw on the inner surface of the cylindrical portion. A method for manufacturing a steel pipe for a frame, which comprises repeating a process of inserting the cylindrical portion into a mold having a shaped cavity and pressing the cylinder portion using a plurality of molds whose sizes are gradually reduced. A height-adjustable frame member comprising the steel pipe for a frame according to claim 1 and a bolt having a male screw that can be screwed into the female screw. A height-adjustable bathroom unit installation frame, characterized in that the frame member according to claim 2 is used as the grounding member.

Images